325 files changed, 92164 insertions, 12811 deletions

diff --git a/erts/Makefile b/erts/Makefile
index 60c70b6a2c..e62c896170 100644
--- a/erts/Makefile
+++ b/erts/Makefile
@@ -129,9 +129,13 @@ makefiles:
 
 .PHONY: release
 release:
+ifeq ($(TYPE),)
 	for t in $(TYPES); do \
 	  ( cd emulator && $(MAKE) release TYPE=$$t ) || exit $$?; \
 	done
+else
+	( cd emulator && $(MAKE) release TYPE=$(TYPE) ) || exit $$?;
+endif
 	$(V_at)for d in $(ERTSDIRS) $(XINSTDIRS); do \
 		if test -d $$d; then \
 			( cd $$d && $(MAKE) $@ ) || exit $$? ; \
diff --git a/erts/aclocal.m4 b/erts/aclocal.m4
index 3d227e462c..0ca2755802 100644
--- a/erts/aclocal.m4
+++ b/erts/aclocal.m4
@@ -122,6 +122,9 @@ dnl
 
 AC_DEFUN(LM_WINDOWS_ENVIRONMENT,
 [
+
+if test "X$windows_environment_" != "Xchecked"; then
+windows_environment_=checked
 MIXED_CYGWIN=no
 MIXED_MSYS=no
 
@@ -197,6 +200,8 @@ else
 fi
 
 AC_SUBST(MIXED_MSYS)
+
+fi
 ])		
 	
 dnl ----------------------------------------------------------------------
@@ -2856,3 +2861,248 @@ AC_DEFUN([LM_HARDWARE_ARCH], [
 
     AC_SUBST(ARCH)
 ])
+
+dnl
+dnl--------------------------------------------------------------------
+dnl Dynamic Erlang Drivers
+dnl
+dnl Linking to produce dynamic Erlang drivers to be loaded by Erlang's
+dnl Dynamic Driver Loader and Linker (DDLL). Below the prefix DED is an
+dnl abbreviation for `Dynamic Erlang Driver'.
+dnl
+dnl For DED we need something quite sloppy, which allows undefined references 
+dnl (notably driver functions) in the resulting shared library. 
+dnl Example of Makefile rule (and settings of macros):
+dnl
+dnl LIBS = @LIBS@
+dnl LD = @DED_LD@
+dnl LDFLAGS = @DED_LDFLAGS@
+dnl soname = @ldsoname@
+dnl
+dnl my_drv.so:   my_drv.o my_utils.o
+dnl              $(LD) $(LDFLAGS) $(soname) $@ -o $@ $^ -lc $(LIBS)
+dnl
+dnl--------------------------------------------------------------------
+dnl
+
+AC_DEFUN(ERL_DED,
+	[
+
+USER_LD=$LD
+USER_LDFLAGS="$LDFLAGS"
+
+LM_CHECK_THR_LIB
+
+DED_CC=$CC
+DED_GCC=$GCC
+
+DED_CFLAGS=
+DED_OSTYPE=unix
+case $host_os in
+     linux*)
+	DED_CFLAGS="-D_GNU_SOURCE" ;;
+     win32)
+	DED_CFLAGS="-D_WIN32_WINNT=0x0600 -DWINVER=0x0600"
+        DED_OSTYPE=win32 ;;
+     *)
+        ;;
+esac
+
+
+DED_WARN_FLAGS="-Wall -Wstrict-prototypes"
+case "$host_cpu" in
+  tile*)
+    # tile-gcc is a bit stricter with -Wmissing-prototypes than other gccs,
+    # and too strict for our taste.
+    ;;
+  *)
+    DED_WARN_FLAGS="$DED_WARN_FLAGS -Wmissing-prototypes";;
+esac
+  
+LM_TRY_ENABLE_CFLAG([-Wdeclaration-after-statement], [DED_WARN_FLAGS])
+
+LM_TRY_ENABLE_CFLAG([-Werror=return-type], [DED_WERRORFLAGS])
+LM_TRY_ENABLE_CFLAG([-Werror=implicit], [DED_WERRORFLAGS])
+LM_TRY_ENABLE_CFLAG([-Werror=undef], [DED_WERRORFLAGS])
+
+DED_SYS_INCLUDE="-I${ERL_TOP}/erts/emulator/beam -I${ERL_TOP}/erts/include -I${ERL_TOP}/erts/include/$host -I${ERL_TOP}/erts/include/internal -I${ERL_TOP}/erts/include/internal/$host -I${ERL_TOP}/erts/emulator/sys/$DED_OSTYPE -I${ERL_TOP}/erts/emulator/sys/common"
+DED_INCLUDE=$DED_SYS_INCLUDE
+
+if test "$THR_DEFS" = ""; then
+    DED_THR_DEFS="-D_THREAD_SAFE -D_REENTRANT"
+else
+    DED_THR_DEFS="$THR_DEFS"
+fi
+# DED_EMU_THR_DEFS=$EMU_THR_DEFS
+DED_CFLAGS="$CFLAGS $CPPFLAGS $DED_CFLAGS"
+if test "x$GCC" = xyes; then
+    DED_STATIC_CFLAGS="$DED_CFLAGS"
+    DED_CFLAGS="$DED_CFLAGS -fPIC"
+fi
+
+DED_EXT=so
+case $host_os in
+    win32) DED_EXT=dll;;
+    darwin*)
+	DED_CFLAGS="$DED_CFLAGS -fno-common"
+	DED_STATIC_CFLAGS="$DED_STATIC_CFLAGS -fno-common";;
+    *)
+	;;
+esac
+
+DED_STATIC_CFLAGS="$DED_STATIC_CFLAGS -DSTATIC_ERLANG_NIF -DSTATIC_ERLANG_DRIVER"
+
+if test "$CFLAG_RUNTIME_LIBRARY_PATH" = ""; then
+
+  CFLAG_RUNTIME_LIBRARY_PATH="-Wl,-R"
+  case $host_os in
+    darwin*)
+	CFLAG_RUNTIME_LIBRARY_PATH=
+	;;
+    win32)
+	CFLAG_RUNTIME_LIBRARY_PATH=
+	;;
+    osf*)
+	CFLAG_RUNTIME_LIBRARY_PATH="-Wl,-rpath,"
+	;;
+    *)
+	;;
+  esac
+
+fi
+
+# If DED_LD is set in environment, we expect all DED_LD* variables
+# to be specified (cross compiling)
+if test "x$DED_LD" = "x"; then
+
+DED_LD_FLAG_RUNTIME_LIBRARY_PATH="-R"
+case $host_os in
+	win32)
+		DED_LD="ld.sh"
+		DED_LDFLAGS="-dll"
+		DED_LD_FLAG_RUNTIME_LIBRARY_PATH=
+	;;
+	solaris2*|sysv4*)
+		DED_LDFLAGS="-G"
+		if test X${enable_m64_build} = Xyes; then
+			DED_LDFLAGS="-64 $DED_LDFLAGS"
+		fi
+	;;
+	aix4*)
+		DED_LDFLAGS="-G -bnoentry -bexpall"
+	;;
+	freebsd2*)
+		# Non-ELF GNU linker
+		DED_LDFLAGS="-Bshareable"
+	;;
+	darwin*)
+		# Mach-O linker: a shared lib and a loadable
+		# object file is not the same thing.
+		DED_LDFLAGS="-bundle -bundle_loader ${ERL_TOP}/bin/$host/beam.smp"
+		if test X${enable_m64_build} = Xyes; then
+		  DED_LDFLAGS="-m64 $DED_LDFLAGS"
+		else
+		  if test X${enable_m32_build} = Xyes; then
+		    DED_LDFLAGS="-m32 $DED_LDFLAGS"
+		  else
+		    AC_CHECK_SIZEOF(void *)
+		    case "$ac_cv_sizeof_void_p" in
+		      8)
+			DED_LDFLAGS="-m64 $DED_LDFLAGS";;
+		      *)
+		        ;;
+		    esac
+		  fi
+		fi
+		DED_LD="$CC"
+		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="$CFLAG_RUNTIME_LIBRARY_PATH"
+	;;
+	linux*)
+		DED_LD="$CC"
+		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="$CFLAG_RUNTIME_LIBRARY_PATH"
+		DED_LDFLAGS="-shared -Wl,-Bsymbolic"
+		if test X${enable_m64_build} = Xyes; then
+			DED_LDFLAGS="-m64 $DED_LDFLAGS"
+		fi;
+		if test X${enable_m32_build} = Xyes; then
+			DED_LDFLAGS="-m32 $DED_LDFLAGS"
+		fi
+	;;	
+	freebsd*)
+		DED_LD="$CC"
+		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="$CFLAG_RUNTIME_LIBRARY_PATH"
+		DED_LDFLAGS="-shared"
+		if test X${enable_m64_build} = Xyes; then
+			DED_LDFLAGS="-m64 $DED_LDFLAGS"
+		fi;
+		if test X${enable_m32_build} = Xyes; then
+			DED_LDFLAGS="-m32 $DED_LDFLAGS"
+		fi
+	;;	
+	openbsd*)
+		DED_LD="$CC"
+		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="$CFLAG_RUNTIME_LIBRARY_PATH"
+		DED_LDFLAGS="-shared"
+	;;
+	osf*)
+		# NOTE! Whitespace after -rpath is important.
+		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="-rpath "
+		DED_LDFLAGS="-shared -expect_unresolved '*'"
+	;;
+	*)
+		# assume GNU linker and ELF
+		DED_LDFLAGS="-shared"
+		# GNU linker has no option for 64bit build, should not propagate -m64
+	;;
+esac
+
+if test "$DED_LD" = "" && test "$USER_LD" != ""; then
+    DED_LD="$USER_LD"
+    DED_LDFLAGS="$USER_LDFLAGS $DED_LDFLAGS"
+fi
+
+DED_LIBS=$LIBS
+
+fi # "x$DED_LD" = "x"
+
+AC_CHECK_TOOL(DED_LD, ld, false)
+test "$DED_LD" != "false" || AC_MSG_ERROR([No linker found])
+
+AC_MSG_CHECKING(for static compiler flags)
+DED_STATIC_CFLAGS="$DED_WERRORFLAGS $DED_WFLAGS $DED_THR_DEFS $DED_STATIC_CFLAGS"
+AC_MSG_RESULT([$DED_STATIC_CFLAGS])
+AC_MSG_CHECKING(for basic compiler flags for loadable drivers)
+DED_BASIC_CFLAGS=$DED_CFLAGS
+AC_MSG_RESULT([$DED_CFLAGS])
+AC_MSG_CHECKING(for compiler flags for loadable drivers)
+DED_CFLAGS="$DED_WERRORFLAGS $DED_WARN_FLAGS $DED_THR_DEFS $DED_CFLAGS"
+AC_MSG_RESULT([$DED_CFLAGS])
+AC_MSG_CHECKING(for linker for loadable drivers)
+AC_MSG_RESULT([$DED_LD])
+AC_MSG_CHECKING(for linker flags for loadable drivers)
+AC_MSG_RESULT([$DED_LDFLAGS])
+AC_MSG_CHECKING(for 'runtime library path' linker flag)
+if test "x$DED_LD_FLAG_RUNTIME_LIBRARY_PATH" != "x"; then
+	AC_MSG_RESULT([$DED_LD_FLAG_RUNTIME_LIBRARY_PATH])
+else
+	AC_MSG_RESULT([not found])
+fi
+
+AC_SUBST(DED_CC)
+AC_SUBST(DED_GCC)
+AC_SUBST(DED_EXT)
+AC_SUBST(DED_SYS_INCLUDE)
+AC_SUBST(DED_INCLUDE)
+AC_SUBST(DED_BASIC_CFLAGS)
+AC_SUBST(DED_CFLAGS)
+AC_SUBST(DED_STATIC_CFLAGS)
+AC_SUBST(DED_WARN_FLAGS)
+AC_SUBST(DED_WERRORFLAGS)
+AC_SUBST(DED_LD)
+AC_SUBST(DED_LDFLAGS)
+AC_SUBST(DED_LD_FLAG_RUNTIME_LIBRARY_PATH)
+AC_SUBST(DED_LIBS)
+AC_SUBST(DED_THR_DEFS)
+AC_SUBST(DED_OSTYPE)
+
+])
diff --git a/erts/autoconf/configure.vxworks b/erts/autoconf/configure.vxworks
index a253848403..c3bdfd0095 100755
--- a/erts/autoconf/configure.vxworks
+++ b/erts/autoconf/configure.vxworks
@@ -93,6 +93,7 @@ erts_lib_src=${ERL_TOP}/erts/lib_src
 erts_incl=${ERL_TOP}/erts/include
 erts_incl_intrnl=${ERL_TOP}/erts/include/internal
 etcdir=${ERL_TOP}/erts/etc/common
+erlint_incl_dir=${ERL_TOP}/lib/erl_interface/include
 erlint_dir=${ERL_TOP}/lib/erl_interface/src
 epmd_dir=${ERL_TOP}/erts/epmd/src
 os_mon_dir=${ERL_TOP}/lib/os_mon/c_src
@@ -109,6 +110,7 @@ CONFIG_FILES="${ERL_TOP}/erts/emulator/$host/Makefile
 	    $erts_incl_intrnl/$host/ethread.mk
 	    $erts_incl_intrnl/$host/ethread_header_config.h
 	    $etcdir/$host/Makefile
+	    $erlint_incl_dir/$host/ei_config.h
 	    $erlint_dir/$host/Makefile
 	    $erlint_dir/$host/eidefs.mk
 	    $epmd_dir/$host/Makefile
@@ -133,6 +135,7 @@ for file in $CONFIG_FILES; do
 	-e "s,@HOST_TYPE@,$HOST_TYPE,g" \
 	-e "s,@WIND_BASE@,$WIND_BASE,g" \
 	-e "s,@TARGET@,$target,g" \
+        -e "s,@ENV_CFLAGS@,$CFLAGS,g" \
 	$in_file > $new_name
 done
 
diff --git a/erts/autoconf/vxworks/sed.general b/erts/autoconf/vxworks/sed.general
index 0e99b4dba4..ffd5a8133c 100644
--- a/erts/autoconf/vxworks/sed.general
+++ b/erts/autoconf/vxworks/sed.general
@@ -103,7 +103,6 @@ s|@INSTALL_PROGRAM@|${INSTALL}|
 s|@INSTALL_SCRIPT@|${INSTALL}|
 s|@INSTALL_DATA@|${INSTALL} -m 644|
 s|@INSTALL_DIR@|$(INSTALL) -d|
-s|@RM@|/bin/rm|
 s|@MKDIR@|/bin/mkdir|
 s|@ERLANG_OSTYPE@|vxworks|
 s|@vxworks_reclaim@|reclaim.h|
@@ -112,7 +111,7 @@ s|@erlexec@|erl.exec|
 s|@EMU_LIBOBJS@||
 
 # General CFLAGS
-s|@GENERAL_CFLAGS@|-DHAVE_LOCALTIME_R -DHAVE_GMTIME_R -DENABLE_ELIB_MALLOC -DELIB_HEAP_USER -DELIB_SORTED_BLOCKS -DWORDS_BIGENDIAN -DELIB_DONT_INITIALIZE -DSIZEOF_CHAR=1 -DSIZEOF_SHORT=2 -DSIZEOF_INT=4 -DSIZEOF_LONG=4 -DSIZEOF_LONG_LONG=8 -DSIZEOF_VOID_P=4 -DERTS_USE_PORT_TASKS=1|g
+s|@GENERAL_CFLAGS@|@ENV_CFLAGS@ -DHAVE_LOCALTIME_R -DHAVE_GMTIME_R -DENABLE_ELIB_MALLOC -DELIB_HEAP_USER -DELIB_SORTED_BLOCKS -DWORDS_BIGENDIAN -DELIB_DONT_INITIALIZE -DSIZEOF_CHAR=1 -DSIZEOF_SHORT=2 -DSIZEOF_INT=4 -DSIZEOF_LONG=4 -DSIZEOF_LONG_LONG=8 -DSIZEOF_VOID_P=4 -DERTS_USE_PORT_TASKS=1|g
 s|@WFLAGS@||
 
 # Thread flags for eidefs.mk (erl_interface)
diff --git a/erts/configure.in b/erts/configure.in
index 9245e4dc90..3a043c940d 100644
--- a/erts/configure.in
+++ b/erts/configure.in
@@ -2,7 +2,7 @@ dnl Process this file with autoconf to produce a configure script. -*-m4-*-
 
 dnl %CopyrightBegin%
 dnl
-dnl Copyright Ericsson AB 1997-2018. All Rights Reserved.
+dnl Copyright Ericsson AB 1997-2019. All Rights Reserved.
 dnl
 dnl Licensed under the Apache License, Version 2.0 (the "License");
 dnl you may not use this file except in compliance with the License.
@@ -26,11 +26,6 @@ AC_PREREQ(2.59)
 
 LM_PRECIOUS_VARS
 
-if test "x$no_recursion" != "xyes" -a "x$OVERRIDE_CONFIG_CACHE" = "x"; then
-    # We do not want to use a common cache!
-    cache_file=/dev/null
-fi
-
 dnl How to set srcdir absolute is taken from the GNU Emacs distribution
 #### Make srcdir absolute, if it isn't already.  It's important to
 #### avoid running the path through pwd unnecessary, since pwd can
@@ -470,7 +465,10 @@ dnl
 dnl Make sure we find config.h
 dnl
 
-extra_flags="-I${ERL_TOP}/erts/$host $OTP_EXTRA_FLAGS"
+ERTS_CONFIG_H_IDIR="-I${ERL_TOP}/erts/$host"
+AC_SUBST(ERTS_CONFIG_H_IDIR)
+
+extra_flags="$ERTS_CONFIG_H_IDIR $OTP_EXTRA_FLAGS"
 CFLAGS="$CFLAGS $extra_flags"
 DEBUG_CFLAGS="-g $CPPFLAGS $extra_flags $DEBUG_CFLAGS"
 DEBUG_FLAGS=-g
@@ -502,23 +500,6 @@ case $CFLAGS in
 		;;
 esac
 
-
-
-CFLAG_RUNTIME_LIBRARY_PATH="-Wl,-R"
-case $host_os in
-  darwin*)
-	CFLAG_RUNTIME_LIBRARY_PATH=
-	;;
-  win32)
-	CFLAG_RUNTIME_LIBRARY_PATH=
-	;;
-  osf*)
-	CFLAG_RUNTIME_LIBRARY_PATH="-Wl,-rpath,"
-	;;
-  *)
-	;;
-esac
-
 lfs_conf=ok
 lfs_source=none
 if test "${LFS_CFLAGS+set}" = "set" || \
@@ -605,11 +586,26 @@ AC_SUBST(DEBUG_FLAGS)
 AC_SUBST(DEBUG_CFLAGS)
 AC_SUBST(WFLAGS)
 AC_SUBST(WERRORFLAGS)
-AC_SUBST(CFLAG_RUNTIME_LIBRARY_PATH)
 
 ## Check if we can do profile guided optimization of beam_emu
 LM_CHECK_ENABLE_CFLAG([-fprofile-generate -Werror],[PROFILE_GENERATE])
 LM_CHECK_ENABLE_CFLAG([-fprofile-use -Werror],[PROFILE_USE])
+LM_CHECK_ENABLE_CFLAG([-fprofile-use -fprofile-correction -Werror],[PROFILE_CORRECTION])
+
+if test "X$PROFILE_CORRECTION" = "Xtrue"; then
+   saved_CFLAGS=$CFLAGS
+   saved_LDFLAGS=$LDFLAGS
+   CFLAGS="-fprofile-generate $saved_CFLAGS"
+   LDFLAGS="-fprofile-generate $saved_LDFLAGS"
+   AC_MSG_CHECKING([whether $CC links with -fprofile-generate])
+   AC_LINK_IFELSE([AC_LANG_PROGRAM([],[return 0;])],
+        [AC_MSG_RESULT([yes])
+         PROFILE_GENERATE=true],
+        [AC_MSG_RESULT([no])
+         PROFILE_GENERATE=false])
+   CFLAGS=$saved_CFLAGS
+   LDFLAGS=$saved_LDFLAGS
+fi
 
 ## Check if this is clang
 LM_CHECK_ENABLE_CFLAG([-fprofile-instr-generate -Werror],[PROFILE_INSTR_GENERATE])
@@ -634,8 +630,8 @@ if test "X$PROFILE_INSTR_GENERATE" = "Xtrue"; then
       if test "X$LLVM_PROFDATA" != "X"; then
         CFLAGS="-fprofile-instr-use=default.profdata -Werror $saved_CFLAGS";
         $LLVM_PROFDATA merge -output=default.profdata *.profraw;
-        AC_MSG_CHECKING([whether gcc accepts -fprofile-instr-use=default.profdata -Werror])
-        AC_COMPILE_IFELSE([],
+        AC_MSG_CHECKING([whether $CC accepts -fprofile-instr-use=default.profdata -Werror])
+        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[return 0;])],
           [AC_MSG_RESULT([yes])
            PROFILE_INSTR_USE=true],
           [AC_MSG_RESULT([no])
@@ -657,8 +653,6 @@ AS_HELP_STRING([--enable-pgo],
   esac
 ],enable_pgo=default)
 
-LM_CHECK_ENABLE_CFLAG([-fprofile-use -fprofile-correction -Werror],[PROFILE_CORRECTION])
-
 USE_PGO=false
 AC_MSG_CHECKING([whether to do PGO of erts])
 if test $enable_pgo = no; then
@@ -682,7 +676,7 @@ elif test "X$PROFILE_INSTR_GENERATE" = "Xtrue" -a "X$PROFILE_INSTR_USE" = "Xtrue
   PROFILE_COMPILER=clang
   AC_MSG_RESULT([yes, using -fprofile-instr-generate])
 else
-  if $enable_pgo = yes; then
+  if test $enable_pgo = yes; then
     AC_MSG_ERROR(cannot use PGO with this compiler)
   else
     AC_MSG_RESULT([no])
@@ -792,11 +786,6 @@ AC_SUBST(LIBCARBON)
 
 _search_path=/bin:/usr/bin:/usr/local/bin:$PATH
 
-AC_PATH_PROG(RM, rm, false, $_search_path)
-if test "$ac_cv_path_RM" = false; then
-  AC_MSG_ERROR([No 'rm' command found])
-fi
-
 AC_PATH_PROG(MKDIR, mkdir, false, $_search_path)
 if test "$ac_cv_path_MKDIR" = false; then
   AC_MSG_ERROR([No 'mkdir' command found])
@@ -811,9 +800,9 @@ _search_path=
 
 
 # Remove old configuration information.
-# Next line should be placed after AC_PATH_PROG(RM, ...), but before
-# first output to CONN_INFO. So this is just the right place.
-$RM -f "$ERL_TOP/erts/CONF_INFO"
+# Next line should be before first output to CONN_INFO. So this is
+# just the right place.
+rm -f "$ERL_TOP/erts/CONF_INFO"
 
 dnl Check if we should/can build a sharing-preserving emulator
 AC_MSG_CHECKING(if we are building a sharing-preserving emulator)
@@ -851,7 +840,7 @@ fi
 
 ## Delete previous failed configure results
 if test -f doc/CONF_INFO; then
-   $RM doc/CONF_INFO
+   rm -f doc/CONF_INFO
 fi
 
 AC_CHECK_PROGS(XSLTPROC, xsltproc)
@@ -949,9 +938,6 @@ esac
 
 AC_SUBST(LD)
 
-LDFLAG_RUNTIME_LIBRARY_PATH="$CFLAG_RUNTIME_LIBRARY_PATH"
-AC_SUBST(LDFLAG_RUNTIME_LIBRARY_PATH)
-
 dnl Check for cygwin and object/exe files extension
 dnl AC_CYGWIN is deprecated
 AC_EXEEXT
@@ -1357,6 +1343,35 @@ LIBS=$zlib_save_LIBS
 fi
 AC_SUBST(Z_LIB)
 
+
+dnl -------------
+dnl esock
+dnl -------------
+
+AC_ARG_ENABLE(esock,
+AS_HELP_STRING([--enable-esock], [enable builtin experimental socket (as a nif) support (default)])
+AS_HELP_STRING([--disable-esock], [disable builtin experimental socket (as a nif) support]))
+
+dnl Default value
+USE_ESOCK=yes
+
+if test "x$enable_esock" = "xyes"; then
+    USE_ESOCK=yes
+else
+    if test "x$enable_esock" = "xno"; then
+        USE_ESOCK=no
+    fi
+fi
+
+if test "x$USE_ESOCK" = "xyes"; then
+    if test "x$USE_ESOCK" = "xyes"; then
+        AC_CHECK_FUNCS([localtime_r strftime])
+    fi
+fi
+
+AC_SUBST(USE_ESOCK)
+
+
 dnl
 dnl This test kindly borrowed from Tcl
 dnl
@@ -1523,7 +1538,7 @@ dnl Some Linuxes needs <sys/socketio.h> instead of <sys/sockio.h>
 dnl
 AC_CHECK_HEADERS(fcntl.h limits.h unistd.h syslog.h dlfcn.h ieeefp.h \
                  sys/types.h sys/stropts.h sys/sysctl.h \
-                 sys/ioctl.h sys/time.h sys/uio.h \
+                 sys/ioctl.h sys/time.h sys/uio.h sys/mman.h \
                  sys/socket.h sys/sockio.h sys/socketio.h \
                  net/errno.h malloc.h arpa/nameser.h libdlpi.h \
 		 pty.h util.h libutil.h utmp.h langinfo.h poll.h sdkddkver.h)
@@ -1678,7 +1693,9 @@ if test x"$ac_cv_header_netinet_sctp_h" = x"yes"; then
                       struct sctp_paddrparams.spp_sackdelay,
                       struct sctp_paddrparams.spp_flags,
                       struct sctp_remote_error.sre_data,
-                      struct sctp_send_failed.ssf_data], [], [],
+                      struct sctp_send_failed.ssf_data,
+                      struct sctp_event_subscribe.sctp_authentication_event,
+                      struct sctp_event_subscribe.sctp_sender_dry_event], [], [],
         [#if HAVE_SYS_SOCKET_H
          #include <sys/socket.h>
          #endif
@@ -2074,29 +2091,6 @@ esac
 
 AC_CHECK_DECLS([posix2time, time2posix],,,[#include <time.h>])
 
-disable_vfork=false
-if test "x$EMU_THR_LIB_NAME" != "x"; then
-	AC_MSG_CHECKING([if vfork is known to hang multithreaded applications])
-	case $host_os in
-		osf*)
-			AC_MSG_RESULT(yes)
-			disable_vfork=true;;
-		*)
-			AC_MSG_RESULT(no);;
-	esac
-fi
-
-if test $disable_vfork = false; then
-	AC_FUNC_VFORK
-	if test $ac_cv_func_vfork_works = no; then
-		disable_vfork=true
-	fi
-fi
-
-if test $disable_vfork = true; then
-	AC_DEFINE(DISABLE_VFORK, 1, [Define if you want to disable vfork.])
-fi
-
 AC_FUNC_VPRINTF
 
 dnl The AC_DEFINEs are necessary for autoheader to work. :-(
@@ -2832,6 +2826,32 @@ AC_SUBST(HIPE_ENABLED)
 NATIVE_LIBS_ENABLED=
 if test X${enable_native_libs} = Xyes -a X${HIPE_ENABLED} = Xyes; then
   NATIVE_LIBS_ENABLED=yes
+  cat >> $ERL_TOP/erts/CONF_INFO <<EOF
+
+                 WARNING: In OTP 22, HiPE (the native code compiler) is
+		 not fully functional. The reasons for this are:
+
+		 1. There are new BEAM instructions for binary
+		 matching that the HiPE native code compiler does not
+		 support. 
+
+		 2. The new optimizations in the Erlang compiler create
+		 new combination of instructions that HiPE currently
+		 does not handle correctly.
+
+		 If erlc is invoked like so:
+
+		     erlc +native some_file.erl
+
+                 or like so:
+
+                     erlc +native some_file.beam
+
+		 and if any of the new binary matching instructions
+		 are used, the compiler will issue a warning and
+		 produce a BEAM file without native code.
+
+EOF
 fi
 AC_SUBST(NATIVE_LIBS_ENABLED)
 
@@ -3033,165 +3053,6 @@ dnl ----------------------------------------------------------------------
 dnl Stuff that should be moved into their respective application
 dnl ----------------------------------------------------------------------
 
-dnl crypto
-#--------------------------------------------------------------------
-# Dynamic Erlang Drivers
-#
-# Linking to produce dynamic Erlang drivers to be loaded by Erlang's
-# Dynamic Driver Loader and Linker (DDLL). Below the prefix DED is an
-# abbreviation for `Dynamic Erlang Driver'.
-#
-# For DED we need something quite sloppy, which allows undefined references 
-# (notably driver functions) in the resulting shared library. 
-# Example of Makefile rule (and settings of macros):
-#
-# LIBS = @LIBS@
-# LD = @DED_LD@
-# LDFLAGS = @DED_LDFLAGS@
-# soname = @ldsoname@
-#
-# my_drv.so:   my_drv.o my_utils.o
-#              $(LD) $(LDFLAGS) $(soname) $@ -o $@ $^ -lc $(LIBS)
-#
-#--------------------------------------------------------------------
-
-DED_SYS_INCLUDE="-I${ERL_TOP}/erts/emulator/beam -I${ERL_TOP}/erts/include -I${ERL_TOP}/erts/include/$host -I${ERL_TOP}/erts/include/internal -I${ERL_TOP}/erts/include/internal/$host -I${ERL_TOP}/erts/emulator/sys/$ERLANG_OSTYPE -I${ERL_TOP}/erts/emulator/sys/common"
-
-if test "X$ETHR_DEFS" = "X"; then
-    DED_THR_DEFS="-D_THREAD_SAFE -D_REENTRANT"
-else
-    DED_THR_DEFS="$ETHR_DEFS"
-fi
-DED_EMU_THR_DEFS=$EMU_THR_DEFS
-DED_CFLAGS="$CFLAGS $CPPFLAGS"
-if test "x$GCC" = xyes; then
-    DED_STATIC_CFLAGS="$DED_CFLAGS"
-    DED_CFLAGS="$DED_CFLAGS -fPIC"
-fi
-
-DED_EXT=so
-case $host_os in
-    win32) DED_EXT=dll;;
-    darwin*)
-	DED_CFLAGS="$DED_CFLAGS -fno-common"
-	DED_STATIC_CFLAGS="$DED_STATIC_CFLAGS -fno-common";;
-    *)
-	;;
-esac
-
-DED_STATIC_CFLAGS="$DED_STATIC_CFLAGS -DSTATIC_ERLANG_NIF -DSTATIC_ERLANG_DRIVER"
-
-# If DED_LD is set in environment, we expect all DED_LD* variables
-# to be specified (cross compiling)
-if test "x$DED_LD" = "x"; then
-
-DED_LD_FLAG_RUNTIME_LIBRARY_PATH="-R"
-case $host_os in
-	win32)
-		DED_LD="ld.sh"
-		DED_LDFLAGS="-dll"
-		DED_LD_FLAG_RUNTIME_LIBRARY_PATH=
-	;;
-	solaris2*|sysv4*)
-		DED_LDFLAGS="-G"
-		if test X${enable_m64_build} = Xyes; then
-			DED_LDFLAGS="-64 $DED_LDFLAGS"
-		fi
-	;;
-	aix4*)
-		DED_LDFLAGS="-G -bnoentry -bexpall"
-	;;
-	freebsd2*)
-		# Non-ELF GNU linker
-		DED_LDFLAGS="-Bshareable"
-	;;
-	darwin*)
-		# Mach-O linker: a shared lib and a loadable
-		# object file is not the same thing.
-		DED_LDFLAGS="-bundle -bundle_loader ${ERL_TOP}/bin/$host/beam.smp"
-		case $ARCH in
-			amd64)
-				DED_LDFLAGS="-m64 $DED_LDFLAGS"
-				;;
-			*)
-				;;
-		esac
-		DED_LD="$CC"
-		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="$CFLAG_RUNTIME_LIBRARY_PATH"
-	;;
-	linux*)
-		DED_LD="$CC"
-		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="$CFLAG_RUNTIME_LIBRARY_PATH"
-		DED_LDFLAGS="-shared -Wl,-Bsymbolic"
-		if test X${enable_m64_build} = Xyes; then
-			DED_LDFLAGS="-m64 $DED_LDFLAGS"
-		fi;
-		if test X${enable_m32_build} = Xyes; then
-			DED_LDFLAGS="-m32 $DED_LDFLAGS"
-		fi
-	;;	
-	freebsd*)
-		DED_LD="$CC"
-		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="$CFLAG_RUNTIME_LIBRARY_PATH"
-		DED_LDFLAGS="-shared"
-		if test X${enable_m64_build} = Xyes; then
-			DED_LDFLAGS="-m64 $DED_LDFLAGS"
-		fi;
-		if test X${enable_m32_build} = Xyes; then
-			DED_LDFLAGS="-m32 $DED_LDFLAGS"
-		fi
-	;;	
-	openbsd*)
-		DED_LD="$CC"
-		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="$CFLAG_RUNTIME_LIBRARY_PATH"
-		DED_LDFLAGS="-shared"
-	;;
-	osf*)
-		# NOTE! Whitespace after -rpath is important.
-		DED_LD_FLAG_RUNTIME_LIBRARY_PATH="-rpath "
-		DED_LDFLAGS="-shared -expect_unresolved '*'"
-	;;
-	*)
-		# assume GNU linker and ELF
-		DED_LDFLAGS="-shared"
-		# GNU linker has no option for 64bit build, should not propagate -m64
-	;;
-esac
-
-if test "$DED_LD" = "" && test "$USER_LD" != ""; then
-    DED_LD="$USER_LD"
-    DED_LDFLAGS="$USER_LDFLAGS $DED_LDFLAGS"
-fi
-
-fi # "x$DED_LD" = "x"
-
-AC_CHECK_TOOL(DED_LD, ld, false)
-test "$DED_LD" != "false" || AC_MSG_ERROR([No linker found])
-
-AC_MSG_CHECKING(for compiler flags for loadable drivers)
-AC_MSG_RESULT([$DED_CFLAGS])
-AC_MSG_CHECKING(for linker for loadable drivers)
-AC_MSG_RESULT([$DED_LD])
-AC_MSG_CHECKING(for linker flags for loadable drivers)
-AC_MSG_RESULT([$DED_LDFLAGS])
-AC_MSG_CHECKING(for 'runtime library path' linker flag)
-if test "x$DED_LD_FLAG_RUNTIME_LIBRARY_PATH" != "x"; then
-	AC_MSG_RESULT([$DED_LD_FLAG_RUNTIME_LIBRARY_PATH])
-else
-	AC_MSG_RESULT([not found])
-fi
-
-AC_SUBST(DED_EXT)
-AC_SUBST(DED_SYS_INCLUDE)
-AC_SUBST(DED_CFLAGS)
-AC_SUBST(DED_STATIC_CFLAGS)
-AC_SUBST(DED_LD)
-AC_SUBST(DED_LDFLAGS)
-AC_SUBST(DED_LD_FLAG_RUNTIME_LIBRARY_PATH)
-AC_SUBST(DED_THR_DEFS)
-AC_SUBST(DED_EMU_THR_DEFS)
-AC_SUBST(STATIC_CFLAGS)
-
 dnl
 dnl We should look for a compiler that handles jump tables, for beam_emu 
 dnl to be optimized
@@ -3288,14 +3149,14 @@ if test "$enable_dtrace_test" = "yes" ; then
 		AC_MSG_CHECKING([for 2-stage DTrace precompilation])
                 AC_TRY_COMPILE([ #include "foo-dtrace.h" ],
                     [ERLANG_DIST_PORT_BUSY_ENABLED();],
-		    [$RM -f $DTRACE_2STEP_TEST
+		    [rm -f $DTRACE_2STEP_TEST
 		     dtrace -G $DTRACE_CPP $DTRACE_BITS_FLAG -Iemulator/beam -o $DTRACE_2STEP_TEST -s emulator/beam/erlang_dtrace.d conftest.$OBJEXT 2>&AS_MESSAGE_LOG_FD
                      if test -f $DTRACE_2STEP_TEST; then
-			$RM $DTRACE_2STEP_TEST
+			rm -f $DTRACE_2STEP_TEST
                         DTRACE_ENABLED_2STEP=yes
 		     fi],
                     [])
-		$RM -f foo-dtrace.h
+		rm -f foo-dtrace.h
 		AS_IF([test "x$DTRACE_ENABLED_2STEP" = "xyes"],
 		      [AC_MSG_RESULT([yes])],
                       [AC_MSG_RESULT([no])])
@@ -3348,733 +3209,6 @@ if test "$enable_lttng_test" = "yes" ; then
 fi
 
 
-dnl
-dnl SSL, SSH and CRYPTO need the OpenSSL libraries
-dnl
-dnl Check flags --with-ssl, --without-ssl --with-ssl=PATH.
-dnl If no option is given or --with-ssl is set without a path then we
-dnl search for OpenSSL libraries and header files in the standard locations. 
-dnl If set to --without-ssl we disable the use of SSL, SSH and CRYPTO.
-dnl If set to --with-ssl=PATH we use that path as the prefix, i.e. we
-dnl use "PATH/include" and "PATH/lib".
-
-AC_SUBST(SSL_INCLUDE)
-AC_SUBST(SSL_INCDIR)
-AC_SUBST(SSL_LIBDIR)
-AC_SUBST(SSL_FLAGS)
-AC_SUBST(SSL_CRYPTO_LIBNAME)
-AC_SUBST(SSL_SSL_LIBNAME)
-AC_SUBST(SSL_CC_RUNTIME_LIBRARY_PATH)
-AC_SUBST(SSL_LD_RUNTIME_LIBRARY_PATH)
-AC_SUBST(SSL_DED_LD_RUNTIME_LIBRARY_PATH)
-AC_SUBST(SSL_DYNAMIC_ONLY)
-AC_SUBST(SSL_LINK_WITH_KERBEROS)
-AC_SUBST(STATIC_KERBEROS_LIBS)
-AC_SUBST(SSL_LINK_WITH_ZLIB)
-AC_SUBST(STATIC_ZLIB_LIBS)
-
-std_ssl_locations="/usr/local /usr/sfw /usr /opt/local /usr/pkg /usr/local/openssl /usr/lib/openssl /usr/openssl /usr/local/ssl /usr/lib/ssl /usr/ssl /"
-
-AC_ARG_WITH(ssl-zlib,
-AS_HELP_STRING([--with-ssl-zlib=PATH],
-               [specify location of ZLib to be used by OpenSSL])
-AS_HELP_STRING([--with-ssl-zlib],
-               [link SSL with  Zlib (default if found)])
-AS_HELP_STRING([--without-ssl-zlib],
-               [don't link SSL with ZLib]))
-
-
-if  test "x$with_ssl_zlib" = "xno"; then
-	SSL_LINK_WITH_ZLIB=no
-	STATIC_ZLIB_LIBS=
-elif test "x$with_ssl_zlib" = "xyes" || test "x$with_ssl_zlib" = "x"; then
-	if test $erl_xcomp_without_sysroot = yes; then
-		AC_MSG_WARN([Cannot search for zlib; missing cross system root (erl_xcomp_sysroot).])
-		SSL_LINK_WITH_ZLIB=no	
-		STATIC_ZLIB_LIBS=	
-	elif  test "x$MIXED_CYGWIN" = "xyes" -o "x$MIXED_MSYS" = "xyes"; then
-		SSL_LINK_WITH_ZLIB=no	
-		STATIC_ZLIB_LIBS=	
-	else
-		SSL_LINK_WITH_ZLIB=no
-		STATIC_ZLIB_LIBS=
-		AC_MSG_CHECKING(for static ZLib to be used by SSL in standard locations) 
-		for rdir in $std_ssl_locations; do
-			dir="$erl_xcomp_sysroot$rdir"
-			if test "x$ac_cv_sizeof_void_p" = "x8"; then
-				if test -f "$dir/lib64/libz.a"; then
-					SSL_LINK_WITH_ZLIB=yes
-					STATIC_ZLIB_LIBS="$dir/lib64/libz.a"
-					break
-				elif test -f "$dir/lib/64/libz.a"; then
-					SSL_LINK_WITH_ZLIB=yes
-					STATIC_ZLIB_LIBS="$dir/lib/64/libz.a"
-					break
-				fi
-			fi
-			if test -f "$dir/lib/libz.a"; then
-					SSL_LINK_WITH_ZLIB=yes
-				STATIC_ZLIB_LIBS="$dir/lib/libz.a"
-				break
-			fi
-		done
-		if test "x$SSL_LINK_WITH_ZLIB" = "xno"; then
-		       	AC_MSG_RESULT([no])
-		else
-			AC_MSG_RESULT([$STATIC_ZLIB_LIBS])
-		fi
-	fi				
-else
-	SSL_LINK_WITH_ZLIB=no
-	STATIC_ZLIB_LIBS=
-	if test -f "$with_ssl_zlib/libz.a"; then
-		SSL_LINK_WITH_ZLIB=yes
-		STATIC_ZLIB_LIBS=$with_ssl_zlib/libz.a
-	elif test -f "$with_ssl_zlib/lib/libz.a"; then
-		SSL_LINK_WITH_ZLIB=yes
-		STATIC_ZLIB_LIBS=$with_ssl_zlib/lib/libz.a
-	fi
-	if test "x$ac_cv_sizeof_void_p" = "x8"; then
-		if test -f "$with_ssl_zlib/lib64/libz.a"; then
-			SSL_LINK_WITH_ZLIB=yes
-			STATIC_ZLIB_LIBS=$with_ssl_zlib/lib64/libz.a
-		elif test -f "$with_ssl_zlib/lib/64/libz.a"; then
-			SSL_LINK_WITH_ZLIB=yes
-			STATIC_ZLIB_LIBS=$with_ssl_zlib/lib/64/libz.a
-		fi
-	fi
-	if test "x$SSL_LINK_WITH_ZLIB" = "xno"; then
-	       	AC_MSG_ERROR(Invalid path to option --with-ssl-zlib=PATH)
-	fi
-fi
-		
-			
-AC_ARG_WITH(ssl,
-AS_HELP_STRING([--with-ssl=PATH], [specify location of OpenSSL include and lib])
-AS_HELP_STRING([--with-ssl], [use SSL (default)])
-AS_HELP_STRING([--without-ssl], [don't use SSL]))
-
-AC_ARG_WITH(ssl-incl,
-AS_HELP_STRING([--with-ssl-incl=PATH], [location of OpenSSL include dir, if different than specified by --with-ssl=PATH]),
-[
-case X$with_ssl in
-    X | Xyes | Xno) AC_MSG_ERROR([--with-ssl-incl=PATH set without --with-ssl=PATH]);;
-esac
-],
-[with_ssl_incl=$with_ssl]) #default
-
-AC_ARG_WITH(ssl-rpath,
-AS_HELP_STRING([--with-ssl-rpath=yes|no|PATHS],
-               [runtime library path for OpenSSL. Default is "yes", which equates to a
-	       number of standard locations. If "no", then no runtime
-	       library paths will be used. Anything else should be a
-	       comma separated list of paths.]),
-[
-case X$with_ssl in
-    Xno) AC_MSG_ERROR([--with-ssl-rpath set without --with-ssl]);;
-esac
-],
-[with_ssl_rpath=yes]) #default
-
-
-AC_ARG_ENABLE(dynamic-ssl-lib,
-AS_HELP_STRING([--disable-dynamic-ssl-lib],
-               [disable using dynamic openssl libraries]),
-[ case "$enableval" in
-    no) enable_dynamic_ssl=no ;;
-    *)  enable_dynamic_ssl=yes ;;
-  esac ], enable_dynamic_ssl=yes)
-
-#----------------------------------------------------------------------
-# We actually might do the SSL tests twice due to late discovery of 
-# kerberos problems with static linking, in case we redo it all trying
-# dynamic SSL libraries instead.
-#----------------------------------------------------------------------
-
-ssl_done=no
-
-while test "x$ssl_done" != "xyes"; do
-
-ssl_done=yes # Default only one run
-
-# Remove all SKIP files from previous runs
-for a in ssl crypto ssh; do
-  $RM -f $ERL_TOP/lib/$a/SKIP
-done
-
-SSL_DYNAMIC_ONLY=$enable_dynamic_ssl
-SSL_STATIC_ONLY=no
-
-case "$erl_xcomp_without_sysroot-$with_ssl" in
-  yes-* | no-no)
-    SSL_APP=
-    CRYPTO_APP=
-    SSH_APP=
-    if test "$with_ssl" = "no"; then
-	skip="User gave --without-ssl option"
-    else
-	skip="Cannot search for ssl; missing cross system root (erl_xcomp_sysroot)."
-    fi
-    for a in ssl crypto ssh; do
-        echo "$skip" > $ERL_TOP/lib/$a/SKIP
-    done
-    ;;
-  no-yes | no- )
-    # On windows, we could try to find the installation
-    # of Shining Light OpenSSL, which can be found by poking in
-    # the uninstall section in the registry, it's worth a try...
-    extra_dir=""
-    if  test "x$MIXED_CYGWIN" = "xyes"; then
-    	AC_CHECK_PROG(REGTOOL, regtool, regtool, false)
-	if test "$ac_cv_prog_REGTOOL" != false; then
-		wrp="/machine/software/microsoft/windows/currentversion/"
-	   	if test "x$ARCH" = "xamd64"; then
-		   urp="uninstall/openssl (64-bit)_is1/inno setup: app path"
-		   regtool_subsystem=-w
-		else
-		   urp="uninstall/openssl (32-bit)_is1/inno setup: app path"
-		   regtool_subsystem=-W
-		fi	
-		rp="$wrp$urp"
-		if regtool -q $regtool_subsystem get "$rp" > /dev/null; then
-		   true
-		else
-		   # Fallback to unspecified wordlength
-		   urp="uninstall/openssl_is1/inno setup: app path"
-		   rp="$wrp$urp"
-		fi	
-		if regtool -q $regtool_subsystem get "$rp" > /dev/null; then
-			ssl_install_dir=`regtool -q $regtool_subsystem get "$rp"`
-			# Try hard to get rid of spaces...
-			if cygpath -d "$ssl_install_dir" > /dev/null 2>&1; then
-				ssl_install_dir=`cygpath -d "$ssl_install_dir"`
-			fi
-			extra_dir=`cygpath $ssl_install_dir`
-		fi
-	fi
-    elif test "x$MIXED_MSYS" = "xyes"; then
-    	AC_CHECK_PROG(REGTOOL, reg_query.sh, reg_query.sh, false)
-	if test "$ac_cv_prog_REGTOOL" != false; then
-	   	if test "x$ARCH" = "xamd64"; then
-		   rp="HKLM/SOFTWARE/Microsoft/Windows/CurrentVersion/Uninstall/OpenSSL (64-bit)_is1"
-		else
-		   rp="HKLM/SOFTWARE/Microsoft/Windows/CurrentVersion/Uninstall/OpenSSL_is1"
-		fi	
-		key="Inno Setup: App Path"
-		if "$ac_cv_prog_REGTOOL" "$rp" "$key" > /dev/null; then
-			ssl_install_dir=`"$ac_cv_prog_REGTOOL" "$rp" "$key"`
-			extra_dir=`win2msys_path.sh "$ssl_install_dir"`
-		fi
-	fi
-    fi
-    # We search for OpenSSL in the common OS standard locations.
-    SSL_APP=ssl
-    CRYPTO_APP=crypto
-    SSH_APP=ssh
-
-    SSL_CRYPTO_LIBNAME=crypto
-    SSL_SSL_LIBNAME=ssl
-    
-    if  test "x$MIXED_CYGWIN" = "xyes" -o "x$MIXED_MSYS" = "xyes"; then
-    	if test "x$ARCH" = "xamd64"; then
-	  std_win_ssl_locations="/cygdrive/c/OpenSSL-Win64 /c/OpenSSL-Win64 /opt/local64/pgm/OpenSSL"
-	else
-	  std_win_ssl_locations="/cygdrive/c/OpenSSL-Win32 /c/OpenSSL-Win32 /cygdrive/c/OpenSSL /c/OpenSSL /opt/local/pgm/OpenSSL"
-	fi
-    else
-        std_win_ssl_locations=""
-    fi
-
-
-    AC_MSG_CHECKING(for OpenSSL >= 0.9.8c in standard locations)
-    for rdir in $extra_dir $std_win_ssl_locations $std_ssl_locations; do
-	dir="$erl_xcomp_sysroot$rdir"
-	if test -f "$erl_xcomp_isysroot$rdir/include/openssl/opensslv.h"; then
-		is_real_ssl=yes
-		SSL_INCDIR="$dir"
-		if test "x$MIXED_CYGWIN" = "xyes" -o "x$MIXED_MSYS" = "xyes"; then
-			if test -f "$dir/lib/VC/libeay32.lib"; then
-				SSL_RUNTIME_LIBDIR="$rdir/lib/VC"
-				SSL_LIBDIR="$dir/lib/VC"
-				SSL_CRYPTO_LIBNAME=libeay32
-				SSL_SSL_LIBNAME=ssleay32
-			elif test -f "$dir/lib/VC/openssl.lib"; then 
-				SSL_RUNTIME_LIBDIR="$rdir/lib/VC"
-				SSL_LIBDIR="$dir/lib/VC"
-			elif test -f $dir/lib/VC/libeay32MD.lib; then
-		            SSL_CRYPTO_LIBNAME=libeay32MD
-		            SSL_SSL_LIBNAME=ssleay32MD
-			    if test "x$enable_dynamic_ssl" = "xno" && \
-	                       test -f  $dir/lib/VC/static/libeay32MD.lib; then
-				  SSL_RUNTIME_LIBDIR="$rdir/lib/VC/static"
-				  SSL_LIBDIR="$dir/lib/VC/static"
-		            else
-			          SSL_RUNTIME_LIBDIR="$rdir/lib/VC"
-				  SSL_LIBDIR="$dir/lib/VC"
-                            fi 
-			elif test -f "$dir/lib/libeay32.lib"; then
-				SSL_RUNTIME_LIBDIR="$rdir/lib"
-				SSL_LIBDIR="$dir/lib"
-				SSL_CRYPTO_LIBNAME=libeay32
-				SSL_SSL_LIBNAME=ssleay32
-			elif test -f "$dir/lib/openssl.lib"; then
-				SSL_RUNTIME_LIBDIR="$rdir/lib"
-				SSL_LIBDIR="$dir/lib"
-			else
-				is_real_ssl=no
-			fi
-		elif test -f "$dir/lib/powerpc/libsslcrypto.a"; then
-			SSL_CRYPTO_LIBNAME=sslcrypto
-			SSL_LIBDIR="$dir/lib/powerpc/"
-			SSL_RUNTIME_LIBDIR="$rdir/lib/powerpc/"
-		else
-			if test "x$ac_cv_sizeof_void_p" = "x8"; then
-				if test -f "$dir/lib64/libcrypto.a"; then
-					SSL_RUNTIME_LIBDIR="$rdir/lib64"
-					SSL_LIBDIR="$dir/lib64"
-				elif test -f "$dir/lib/64/libcrypto.a"; then
-					SSL_RUNTIME_LIBDIR="$rdir/lib/64"
-					SSL_LIBDIR="$dir/lib/64"
-				elif test -f "$dir/lib64/libcrypto.so"; then
-					SSL_RUNTIME_LIBDIR="$rdir/lib64"
-					SSL_LIBDIR="$dir/lib64"
-				elif test -f "$dir/lib/64/libcrypto.so"; then
-					SSL_RUNTIME_LIBDIR="$rdir/lib/64"
-					SSL_LIBDIR="$dir/lib/64"
-				else
-					SSL_RUNTIME_LIBDIR="$rdir/lib"
-					SSL_LIBDIR="$dir/lib"
-				fi
-			else	 
-				SSL_RUNTIME_LIBDIR="$rdir/lib"
-				SSL_LIBDIR="$dir/lib"
-			fi
-		fi
-		if test '!' -f "$SSL_LIBDIR/lib${SSL_CRYPTO_LIBNAME}.a"; then
-			SSL_DYNAMIC_ONLY=yes
-		elif test '!' -f "$SSL_LIBDIR/lib${SSL_CRYPTO_LIBNAME}.so" -a '!' -f "$SSL_LIBDIR/lib${SSL_CRYPTO_LIBNAME}.dylib"; then
-			SSL_STATIC_ONLY=yes
-		fi
-		SSL_BINDIR="$rdir/bin"
-		if test "x$is_real_ssl" = "xyes" ; then
-			SSL_INCLUDE="-I$dir/include"
-			old_CPPFLAGS=$CPPFLAGS
-			CPPFLAGS=$SSL_INCLUDE
-			AC_EGREP_CPP(^yes$,[
-#include <openssl/opensslv.h>
-#if OPENSSL_VERSION_NUMBER >= 0x0090803fL
-yes
-#endif
-			],[
-			ssl_found=yes
-			],[
-			SSL_APP=
-			ssl_found=no
-         		])
-         		CPPFLAGS=$old_CPPFLAGS
-			if test "x$ssl_found" = "xyes"; then
-			   	if test "x$MIXED_CYGWIN" = "xyes" -o "x$MIXED_MSYS" = "xyes"; then
-				   	ssl_linkable=yes
-				elif test "x${SSL_CRYPTO_LIBNAME}" = "xsslcrypto"; then
-				# This should only be triggered seen OSE
-					ssl_linkable=yes
-				else
-					saveCFLAGS="$CFLAGS"
- 					saveLDFLAGS="$LDFLAGS"
-					saveLIBS="$LIBS"
- 					CFLAGS="$CFLAGS $SSL_INCLUDE"
-					if test "x$SSL_STATIC_ONLY" = "xyes"; then
-						LIBS="${SSL_LIBDIR}/lib${SSL_CRYPTO_LIBNAME}.a"
-					else
-						LDFLAGS="$LDFLAGS -L$SSL_LIBDIR"
-						LIBS="$LIBS -l${SSL_CRYPTO_LIBNAME}"
-					fi
- 					AC_TRY_LINK([
-					#include <stdio.h>
- 					#include <openssl/hmac.h>],
- 					[ 
-					HMAC(0, 0, 0, 0, 0, 0, 0);
- 					],
- 					[ssl_linkable=yes],
- 					[ssl_linkable=no])
- 					CFLAGS="$saveCFLAGS"
- 					LDFLAGS="$saveLDFLAGS"
-					LIBS="$saveLIBS"
-				fi
- 			fi
-	 		if test "x$ssl_found" = "xyes" && test "x$ssl_linkable" = "xyes"; then
-			 	AC_MSG_RESULT([$dir])
-	   			break;
-         		fi
-		fi	
-       fi
-    done
-
-    if test "x$ssl_found" != "xyes" ; then
-	dnl 
-	dnl If no SSL found above, check whether we are running on OpenBSD.
-	dnl
-	case $host_os in
-	openbsd*)
-	       if test -f "$erl_xcomp_isysroot/usr/include/openssl/opensslv.h"; then
-		  # Trust OpenBSD to have everything the in the correct locations.
-		  ssl_found=yes
-		  ssl_linkable=yes
-		  SSL_INCDIR="$erl_xcomp_sysroot/usr"
-	          AC_MSG_RESULT([$SSL_INCDIR])
-		  SSL_RUNTIME_LIB="/usr/lib"
-		  SSL_LIB="$erl_xcomp_sysroot/usr/lib"
-		  SSL_BINDIR="/usr/sbin"
-		  dnl OpenBSD requires us to link with -L and -l
-		  SSL_DYNAMIC_ONLY="yes" 
-		fi
-		;;
-	esac
-    fi
-dnl		Now, certain linuxes have a 64bit libcrypto
-dnl		that cannot build shared libraries (i.e. not PIC)
-dnl		One could argue that this is wrong, but
-dnl		so it is - be adoptable
-    if test "$ssl_found" = "yes" && test "$ssl_linkable" = "yes" && test "$SSL_DYNAMIC_ONLY" != "yes"; then
-	case $host_os in
-		linux*)
-			saveCFLAGS="$CFLAGS"
- 			saveLDFLAGS="$LDFLAGS"
-			saveLIBS="$LIBS"
- 			CFLAGS="$DED_CFLAGS $SSL_INCLUDE"
- 			LDFLAGS="$DED_LDFLAGS"
-			LIBS="$SSL_LIBDIR/libcrypto.a $STATIC_ZLIB_LIBS"
- 			AC_TRY_LINK([
-			#include <stdio.h>
- 			#include <openssl/hmac.h>],
- 			[ 
-			HMAC(0, 0, 0, 0, 0, 0, 0);
- 			],
- 			[ssl_dyn_linkable=yes],
- 			[ssl_dyn_linkable=no])
- 			CFLAGS="$saveCFLAGS"
- 			LDFLAGS="$saveLDFLAGS"
-			LIBS="$saveLIBS"
-			if test "x$ssl_dyn_linkable" != "xyes"; then
-				SSL_DYNAMIC_ONLY=yes
-				AC_MSG_WARN([SSL will be linked against dynamic lib as static lib is not purely relocatable])
-			fi
-			;;
-	esac
-    fi					
-	
-				
-
-
-    if test "x$ssl_found" != "xyes" || test  "x$ssl_linkable" != "xyes"; then
-       if test "x$ssl_found" = "xyes"; then 
-       		AC_MSG_RESULT([found; but not usable])
-       else
-       		AC_MSG_RESULT([no])
-       fi
-       SSL_APP=
-       CRYPTO_APP=
-       SSH_APP=
-       AC_MSG_WARN([No (usable) OpenSSL found, skipping ssl, ssh and crypto applications])
-
-       for a in ssl crypto ssh; do
-           echo "No usable OpenSSL found" > $ERL_TOP/lib/$a/SKIP
-       done
-    fi
-    ;;
-  *)
-    # Option given with PATH to package
-    if test ! -d "$with_ssl" ; then
-       AC_MSG_ERROR(Invalid path to option --with-ssl=PATH)
-    fi
-    if test ! -d "$with_ssl_incl" ; then
-       AC_MSG_ERROR(Invalid path to option --with-ssl-incl=PATH)
-    fi
-    SSL_INCDIR="$with_ssl_incl"
-    SSL_CRYPTO_LIBNAME=crypto
-    SSL_SSL_LIBNAME=ssl
-    if test "x$MIXED_CYGWIN" = "xyes" -o "x$MIXED_MSYS" = "xyes" && test -d "$with_ssl/lib/VC"; then
-	if test -f "$with_ssl/lib/VC/libeay32.lib"; then
-	    SSL_LIBDIR="$with_ssl/lib/VC"
-	    SSL_CRYPTO_LIBNAME=libeay32
-	    SSL_SSL_LIBNAME=ssleay32
-	elif test -f "$with_ssl/lib/VC/openssl.lib"; then 
-	    SSL_LIBDIR="$with_ssl/lib/VC"
-	elif test -f $with_ssl/lib/VC/libeay32MD.lib; then
-	    SSL_CRYPTO_LIBNAME=libeay32MD
-            SSL_SSL_LIBNAME=ssleay32MD
-	    if test "x$enable_dynamic_ssl" = "xno" && \
-	       test -f  $with_ssl/lib/VC/static/libeay32MD.lib; then
-		SSL_LIBDIR="$with_ssl/lib/VC/static"
-	    else
-		SSL_LIBDIR="$with_ssl/lib/VC"
-            fi 
-	elif test -f "$with_ssl/lib/libeay32.lib"; then
-	    SSL_LIBDIR="$with_ssl/lib"
-	    SSL_CRYPTO_LIBNAME=libeay32
-	    SSL_SSL_LIBNAME=ssleay32
-	else
-	    # This probably wont work, but that's what the user said, so...
-	    SSL_LIBDIR="$with_ssl/lib"
-	fi
-    elif test -f "$dir/lib/powerpc/libsslcrypto.a"; then
-	    SSL_CRYPTO_LIBNAME=sslcrypto
-	    SSL_LIBDIR="$with_ssl/lib/powerpc/"
-    elif test "x$ac_cv_sizeof_void_p" = "x8"; then
-	if test -f "$with_ssl/lib64/libcrypto.a"; then
-		SSL_LIBDIR="$with_ssl/lib64"
-	elif test -f "$with_ssl/lib/64/libcrypto.a"; then
-		SSL_LIBDIR="$with_ssl/lib/64"
-	elif test -f "$with_ssl/lib64/libcrypto.so"; then
-		SSL_LIBDIR="$with_ssl/lib64"
-	elif test -f "$with_ssl/lib/64/libcrypto.so"; then
-		SSL_LIBDIR="$with_ssl/lib/64"
-	else
-		SSL_LIBDIR="$with_ssl/lib"
-	fi
-    else	 
-	SSL_LIBDIR="$with_ssl/lib"
-    fi
-    if test '!' -f "${SSL_LIBDIR}/lib${SSL_CRYPTO_LIBNAME}.a"; then
-	SSL_DYNAMIC_ONLY=yes
-    elif test '!' -f ${SSL_LIBDIR}/lib${SSL_CRYPTO_LIBNAME}.so -a '!' -f "$SSL_LIBDIR/lib${SSL_CRYPTO_LIBNAME}.dylib"; then
-	SSL_STATIC_ONLY=yes
-    fi
-    SSL_INCLUDE="-I$with_ssl_incl/include"
-    SSL_APP=ssl
-    CRYPTO_APP=crypto
-    SSH_APP=ssh
-    if test "$cross_compiling" = "yes"; then
-	SSL_RUNTIME_LIBDIR=`echo "$SSL_LIBDIR" | sed -n "s|^$erl_xcomp_sysroot\(/*\)\(.*\)\$|/\2|p"`
-    else
-	SSL_RUNTIME_LIBDIR="$SSL_LIBDIR"
-    fi
-esac
-
-if test "x$SSL_APP" != "x" ; then
-    dnl We found openssl, now check if we use kerberos 5 support
-    dnl FIXME: Do we still support platforms that have Kerberos?
-    AC_MSG_CHECKING(for OpenSSL kerberos 5 support)
-    old_CPPFLAGS=$CPPFLAGS
-    CPPFLAGS=$SSL_INCLUDE
-    AC_EGREP_CPP(^yes$,[
-#include <openssl/opensslv.h>
-#include <openssl/opensslconf.h>
-#if OPENSSL_VERSION_NUMBER < 0x1010000fL && !defined(OPENSSL_NO_KRB5)
-yes
-#endif
-      ],[
-      AC_MSG_RESULT([yes])
-      ssl_krb5_enabled=yes
-      if test "x$SSL_DYNAMIC_ONLY" != "xyes"; then
-          if test -f "$SSL_LIBDIR/libkrb5.a"; then
-              SSL_LINK_WITH_KERBEROS=yes
-	      STATIC_KERBEROS_LIBS="$SSL_LIBDIR/libkrb5.a"
-	      if test -f "$SSL_LIBDIR/libkrb5support.a"; then
-		  STATIC_KERBEROS_LIBS="$STATIC_KERBEROS_LIBS $SSL_LIBDIR/libkrb5support.a"
-	      fi
-	      if test -f "$SSL_LIBDIR/libk5crypto.a"; then
-		  STATIC_KERBEROS_LIBS="$STATIC_KERBEROS_LIBS $SSL_LIBDIR/libk5crypto.a"
-	      fi
-	      if test -f "$SSL_LIBDIR/libresolv.a"; then
-		  STATIC_KERBEROS_LIBS="$STATIC_KERBEROS_LIBS $SSL_LIBDIR/libresolv.a"
-	      fi
-	      if test -f "$SSL_LIBDIR/libcom_err.a"; then
-		  STATIC_KERBEROS_LIBS="$STATIC_KERBEROS_LIBS $SSL_LIBDIR/libcom_err.a"
-	      fi
-          else
-	      AC_MSG_WARN([Kerberos needed but no kerberos static libraries found])
-	      AC_MSG_WARN([Rescanning for dynamic SSL libraries])
-	      enable_dynamic_ssl=yes
-	      ssl_done=no
-	      SSL_LINK_WITH_KERBEROS=no
-	      STATIC_KERBEROS_LIBS=""
-	      ssl_krb5_enabled=no
-	      SSL_WITH_KERBEROS=no
-          fi
-      else 	
-	      SSL_LINK_WITH_KERBEROS=no
-	      STATIC_KERBEROS_LIBS=""
-      fi
-      ],[
-      AC_MSG_RESULT([no])
-      ssl_krb5_enabled=no
-      SSL_WITH_KERBEROS=no
-      ])
-    CPPFLAGS=$old_CPPFLAGS
-    SSL_KRB5_INCLUDE=
-    if test "x$ssl_krb5_enabled" = "xyes" ; then
-        AC_MSG_CHECKING(for krb5.h in standard locations)
-	for dir in $extra_dir "$SSL_INCDIR/include" "$SSL_INCDIR/include/openssl" \
-		"$SSL_INCDIR/include/kerberos" \
-		"$erl_xcomp_isysroot/cygdrive/c/kerberos/include" \
-		"$erl_xcomp_isysroot/usr/local/kerberos/include" \
-		"$erl_xcomp_isysroot/usr/kerberos/include" \
-		"$erl_xcomp_isysroot/usr/include"
-	do
-            if test -f "$dir/krb5.h" ; then
-                SSL_KRB5_INCLUDE="$dir"
-		break
-            fi
-        done
-        if test "x$SSL_KRB5_INCLUDE" = "x" ; then
-	    AC_MSG_RESULT([not found])
-	    SSL_APP=
-	    CRYPTO_APP=
-	    SSH_APP=
-	    AC_MSG_WARN([OpenSSL is configured for kerberos but no krb5.h found])
-	    for a in ssl crypto ssh ; do
-	 	echo "OpenSSL is configured for kerberos but no krb5.h found" > $ERL_TOP/lib/$a/SKIP
-	    done
-        else
-            AC_MSG_RESULT([found in $SSL_KRB5_INCLUDE])
-            SSL_INCLUDE="$SSL_INCLUDE -I$SSL_KRB5_INCLUDE"
-        fi
-    fi
-fi
-
-done # while test ssl_done != yes
-
-SSL_CC_RUNTIME_LIBRARY_PATH=
-SSL_LD_RUNTIME_LIBRARY_PATH=
-SSL_DED_LD_RUNTIME_LIBRARY_PATH=
-cc_rflg="$CFLAG_RUNTIME_LIBRARY_PATH"
-ld_rflg="$LDFLAG_RUNTIME_LIBRARY_PATH"
-ded_ld_rflg="$DED_LD_FLAG_RUNTIME_LIBRARY_PATH"
-
-
-case "$with_ssl_rpath" in
-
-yes)   # Use standard lib locations for ssl runtime library path
-
-  if test "$SSL_APP" != "" && test "$SSL_DYNAMIC_ONLY" = "yes" && \
-   { test "$cc_rflg" != "" || test "$ld_rflg" != "" || test "$ded_ld_rflg" != ""; } ; then
-
-    AC_MSG_CHECKING(for ssl runtime library path to use)
-
-    libdirs="/lib"
-
-    if test "$ac_cv_sizeof_void_p" = "8"; then
-	dir_lib64=no
-	dir_lib_64=no
-
-	case "$SSL_RUNTIME_LIBDIR" in
-	    */lib/64 | */lib/64/ ) dir_lib_64=yes;;
-	    */lib64 | */lib64/ ) dir_lib64=yes;;
-	    *) ;;
-	esac
-
-	for dir in $std_ssl_locations; do
-	    test $dir_lib_64 = no &&
-	    	test -d "$erl_xcomp_sysroot$dir/lib/64" &&
-		    dir_lib_64=yes
-	    test $dir_lib64 = no &&
-		test -d "$erl_xcomp_sysroot$dir/lib64" &&
-		    dir_lib64=yes
-	done
-
-	test $dir_lib_64 = yes && libdirs="/lib/64 $libdirs"
-	test $dir_lib64 = yes && libdirs="/lib64 $libdirs"
-    fi
-
-    for type in std x_std curr; do
-
-        cc_rpath="$cc_rflg$SSL_RUNTIME_LIBDIR"
-        ld_rpath="$ld_rflg$SSL_RUNTIME_LIBDIR"
-        ded_ld_rpath="$ded_ld_rflg$SSL_RUNTIME_LIBDIR"
-	rpath="$SSL_RUNTIME_LIBDIR"
-
-	if test $type != curr; then
-	    for ldir in $libdirs; do
-		for dir in $std_ssl_locations; do
-		    test "$SSL_LIBDIR" != "$dir$ldir" || continue
-		    test $type != x_std || test -d "$dir$ldir" || continue
-		    test "$cc_rflg" = "" ||
-			cc_rpath="$cc_rpath $cc_rflg$dir$ldir"
-		    test "$ld_rflg" = "" ||
-			ld_rpath="$ld_rpath $ld_rflg$dir$ldir"
-		    test "$ded_ld_rflg" = "" ||
-			ded_ld_rpath="$ded_ld_rpath $ded_ld_rflg$dir$ldir"
-		    rpath="$rpath:$dir$ldir"
-                done
-	    done
-	fi
-
-	saveCFLAGS="$CFLAGS"
-	saveLDFLAGS="$LDFLAGS"
-	saveLIBS="$LIBS"
-	CFLAGS="$CFLAGS $SSL_INCLUDE"
-	LDFLAGS="$LDFLAGS $ld_rpath -L$SSL_LIBDIR"
-	LIBS="-lcrypto"
-	AC_TRY_LINK([
-                         #include <stdio.h>
-                         #include <openssl/hmac.h>
-                    ],
-                    [ 
-			 HMAC(0, 0, 0, 0, 0, 0, 0);
-                    ],
-                    [rpath_success=yes],
-                    [rpath_success=no])
-	CFLAGS="$saveCFLAGS"
-	LDFLAGS="$saveLDFLAGS"
-	LIBS="$saveLIBS"
-
-	test "$rpath_success" = "yes" && break
-    done
-
-    test "$rpath_success" = "yes" || { cc_rpath=; ld_rpath=; ded_ld_rpath=; rpath=; }
-
-    SSL_CC_RUNTIME_LIBRARY_PATH="$cc_rpath"
-    SSL_LD_RUNTIME_LIBRARY_PATH="$ld_rpath"
-    SSL_DED_LD_RUNTIME_LIBRARY_PATH="$ded_ld_rpath"
-
-    AC_MSG_RESULT([$rpath])
-    test "$rpath" != "" || AC_MSG_WARN([Cannot set run path during linking])
-  fi
-  ;;
-
-no)   # Use no ssl runtime library path
-  SSL_DED_LD_RUNTIME_LIBRARY_PATH=
-  ;;
-
-*)    # Use ssl runtime library paths set by --with-ssl-rpath (without any check)
-  ded_ld_rpath=
-  delimit=
-  for dir in `echo $with_ssl_rpath | sed "s/,/ /g"`; do
-      ded_ld_rpath="$ded_ld_rpath$delimit$ded_ld_rflg$dir"
-      delimit=" "
-  done
-  SSL_DED_LD_RUNTIME_LIBRARY_PATH="$ded_ld_rpath"
-  ;;
-
-esac
-
-
-AC_ARG_ENABLE(fips,
-AS_HELP_STRING([--enable-fips], [enable OpenSSL FIPS mode support])
-AS_HELP_STRING([--disable-fips], [disable OpenSSL FIPS mode support (default)]),
-[ case "$enableval" in
-    yes) enable_fips_support=yes ;;
-    *)   enable_fips_support=no ;;
-  esac ], enable_fips_support=no)
-
-if test "x$enable_fips_support" = "xyes" && test "$CRYPTO_APP" != ""; then
-   saveCFLAGS="$CFLAGS"
-   saveLDFLAGS="$LDFLAGS"
-   saveLIBS="$LIBS"
-   CFLAGS="$CFLAGS $SSL_INCLUDE"
-   LDFLAGS="$LDFLAGS $SSL_LD_RUNTIME_LIBRARY_PATH -L$SSL_LIBDIR"
-   LIBS="-lcrypto"
-   AC_CHECK_FUNC([FIPS_mode_set],
-   [SSL_FLAGS="-DFIPS_SUPPORT"],
-   [SSL_FLAGS=])
-   CFLAGS="$saveCFLAGS"
-   LDFLAGS="$saveLDFLAGS"
-   LIBS="$saveLIBS"
-else
-   SSL_FLAGS=
-fi
-
 #--------------------------------------------------------------------
 # Os mon stuff.
 #--------------------------------------------------------------------
@@ -4120,7 +3254,7 @@ need_java="jinterface ic/java_src"
 
 # Remove all SKIP files from previous runs
 for a in $need_java ; do
-  $RM -f $ERL_TOP/lib/$a/SKIP
+  rm -f $ERL_TOP/lib/$a/SKIP
 done
 
 if test "X$with_javac" = "Xno"; then
@@ -4171,7 +3305,7 @@ dnl this deliberately does not believe that 'gcc' is a C++ compiler
 AC_CHECK_TOOLS(CXX, [$CCC c++ g++ CC cxx cc++ cl], false)
 
 # Remove SKIP file from previous run
-$RM -f $ERL_TOP/lib/orber/SKIP
+rm -f $ERL_TOP/lib/orber/SKIP
 
 if test "$CXX" = false; then
   echo "No C++ compiler found" > $ERL_TOP/lib/orber/SKIP
@@ -4215,6 +3349,8 @@ AC_DEFINE_UNQUOTED(ERTS_EMU_CMDLINE_FLAGS,
 "$STATIC_CFLAGS $CFLAGS $DEBUG_CFLAGS $EMU_THR_DEFS $DEFS $WERRORFLAGS $WFLAGS",
 [The only reason ERTS_EMU_CMDLINE_FLAGS exists is to force modification of config.h when the emulator command line flags are modified by configure])
 
+AC_SUBST(STATIC_CFLAGS)
+
 dnl ----------------------------------------------------------------------
 dnl Directories needed for the build
 dnl ----------------------------------------------------------------------
@@ -4317,7 +3453,6 @@ AC_CONFIG_FILES([
   include/internal/$host/erts_internal.mk:include/internal/erts_internal.mk.in
   lib_src/$host/Makefile:lib_src/Makefile.in
   ../make/$host/otp.mk:../make/otp.mk.in
-  ../make/$host/otp_ded.mk:../make/otp_ded.mk.in
 ])
 
 AC_CONFIG_FILES([../make/make_emakefile:../make/make_emakefile.in],
@@ -4326,12 +3461,12 @@ AC_CONFIG_FILES([../make/make_emakefile:../make/make_emakefile.in],
 dnl
 dnl The ones below should be moved to their respective lib
 dnl
-dnl  ../lib/ssl/c_src/$host/Makefile:../lib/ssl/c_src/Makefile.in
 AC_CONFIG_FILES([
   ../lib/os_mon/c_src/$host/Makefile:../lib/os_mon/c_src/Makefile.in
-  ../lib/crypto/c_src/$host/Makefile:../lib/crypto/c_src/Makefile.in
   ../lib/runtime_tools/c_src/$host/Makefile:../lib/runtime_tools/c_src/Makefile.in
   ../lib/tools/c_src/$host/Makefile:../lib/tools/c_src/Makefile.in
   ])
 
+AC_CONFIG_FILES([../make/install_dir_data.sh:../make/install_dir_data.sh.in], [chmod +x ../make/install_dir_data.sh])
+
 AC_OUTPUT
diff --git a/erts/doc/src/Makefile b/erts/doc/src/Makefile
index 40f74b78ff..bb96293947 100644
--- a/erts/doc/src/Makefile
+++ b/erts/doc/src/Makefile
@@ -1,7 +1,7 @@
 #
 # %CopyrightBegin%
 #
-# Copyright Ericsson AB 1997-2018. All Rights Reserved.
+# Copyright Ericsson AB 1997-2019. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -47,6 +47,20 @@ XML_REF1_FILES = epmd.xml \
 	run_erl.xml \
 	start.xml
 
+ifeq ($(USE_ESOCK), yes)
+XML_REF3_ESOCK_EFILES = socket.xml
+XML_CHAPTER_ESOCK_EFILES = socket_usage.xml
+ESOCK_USE_SOCKET_XML=<xi:include href="socket.xml"\/>
+ESOCK_USE_SOCKET_SPECS_XML=<xi:include href="../specs/specs_socket.xml"/>
+ESOCK_USE_SOCKET_USAGE_XML=<xi:include href="socket_usage.xml"/>
+else
+XML_REF3_ESOCK_EFILES =
+XML_CHAPTER_ESOCK_EFILES =
+ESOCK_USE_SOCKET_XML =
+ESOCK_USE_SOCKET_SPECS_XML =
+ESOCK_USE_SOCKET_USAGE_XML =
+endif
+
 XML_REF3_EFILES = \
 	erl_prim_loader.xml \
 	erlang.xml \
@@ -55,7 +69,8 @@ XML_REF3_EFILES = \
 	persistent_term.xml \
 	atomics.xml \
 	counters.xml \
-	zlib.xml
+	zlib.xml \
+	$(XML_REF3_ESOCK_EFILES)
 
 XML_REF3_FILES = \
 	$(XML_REF3_EFILES) \
@@ -65,7 +80,22 @@ XML_REF3_FILES = \
 	erts_alloc.xml
 
 XML_PART_FILES = \
-	part.xml
+	part.xml internal.xml
+
+XML_INTERNAL_FILES = \
+	CarrierMigration.xml	\
+	ThreadProgress.xml	\
+	CodeLoading.xml		\
+	Tracing.xml		\
+	DelayedDealloc.xml	\
+	beam_makeops.xml	\
+	GarbageCollection.xml	\
+	PTables.xml		\
+	PortSignals.xml		\
+	ProcessManagementOptimizations.xml \
+	SuperCarrier.xml        \
+	CountingInstructions.xml
+
 
 XML_CHAPTER_FILES = \
 	introduction.xml \
@@ -77,6 +107,7 @@ XML_CHAPTER_FILES = \
 	driver.xml \
 	absform.xml \
 	inet_cfg.xml \
+	$(XML_CHAPTER_ESOCK_EFILES) \
 	erl_ext_dist.xml \
 	erl_dist_protocol.xml \
 	communication.xml \
@@ -94,6 +125,8 @@ XML_FILES = \
 	$(BOOK_FILES) $(XML_CHAPTER_FILES) \
 	$(XML_PART_FILES) $(XML_REF3_FILES) $(XML_REF1_FILES) $(XML_APPLICATION_FILES)
 
+XML_GEN_FILES = $(XML_INTERNAL_FILES:%=$(XMLDIR)/%)
+
 # ----------------------------------------------------
 
 HTML_FILES = $(XML_APPLICATION_FILES:%.xml=$(HTMLDIR)/%.html) \
@@ -113,6 +146,12 @@ SPECS_FILES = $(XML_REF3_EFILES:%.xml=$(SPECDIR)/specs_%.xml)
 
 TOP_SPECS_FILE = specs.xml
 
+XML_FIGURE_DIR = $(XMLDIR)/figures
+
+INTERNAL_DOC_PNG_FILES = $(wildcard ../../emulator/internal_doc/figures/*.png)
+PNG_FILES = $(notdir $(INTERNAL_DOC_PNG_FILES))
+XMLDIR_PNG_FILES = $(PNG_FILES:%=$(XML_FIGURE_DIR)/%)
+
 # ----------------------------------------------------
 # FLAGS
 # ----------------------------------------------------
@@ -125,10 +164,15 @@ SPECS_FLAGS = -I$(KERNEL_SRC) -I$(KERNEL_INCLUDE)
 # ----------------------------------------------------
 # Targets
 # ----------------------------------------------------
+_create_dirs := $(shell mkdir -p $(XML_FIGURE_DIR))
+
 $(HTMLDIR)/%.gif: %.gif
 	$(INSTALL_DATA) $< $@
 
-docs: man pdf html $(INFO_FILE)
+$(XML_FIGURE_DIR)/%.png: ../../emulator/internal_doc/figures/%.png
+	$(INSTALL_DATA) $< $@
+
+docs: part ref_man specs figures man pdf html $(INFO_FILE)
 
 $(TOP_PDF_FILE): $(XML_FILES)
 
@@ -138,14 +182,21 @@ html: gifs $(HTML_REF_MAN_FILE)
 
 man: $(MAN1_FILES) $(MAN3_FILES)
 
+ref_man: ref_man.xml
+part: part.xml
+specs: specs.xml
+
 gifs: $(GIF_FILES:%=$(HTMLDIR)/%)
 
 $(INFO_FILE): $(INFO_FILE_SRC) $(ERL_TOP)/make/$(TARGET)/otp.mk
 	sed -e 's;%RELEASE%;$(SYSTEM_VSN);' $(INFO_FILE_SRC) > $(INFO_FILE)
 
+figures: $(XMLDIR_PNG_FILES)
 
 debug opt:
 
+ldocs: xmllint local_docs
+
 clean:
 	rm -rf $(HTMLDIR)/*
 	rm -rf $(XMLDIR)
@@ -159,6 +210,22 @@ $(SPECDIR)/specs_%.xml:
 	$(gen_verbose)escript $(SPECS_EXTRACTOR) $(SPECS_FLAGS) \
                 -o$(dir $@) -module $(patsubst $(SPECDIR)/specs_%.xml,%,$@)
 
+$(XMLDIR)/%.xml: ../../emulator/internal_doc/%.md $(ERL_TOP)/make/emd2exml
+	$(ERL_TOP)/make/emd2exml $< $@
+
+ref_man.xml: ref_man.xml.src
+	($(PERL) -p -e 's?%ESOCK_USE_SOCKET_XML%?$(ESOCK_USE_SOCKET_XML)?' \
+            $<) > $@
+
+part.xml: part.xml.src
+	($(PERL) -p -e 's?%ESOCK_USE_SOCKET_USAGE_XML%?$(ESOCK_USE_SOCKET_USAGE_XML)?' \
+            $<) > $@
+
+specs.xml: specs.xml.src
+	($(PERL) -p -e 's?%ESOCK_USE_SOCKET_SPECS_XML%?$(ESOCK_USE_SOCKET_SPECS_XML)?' \
+            $<) > $@
+
+
 # ----------------------------------------------------
 # Release Target
 # ----------------------------------------------------
@@ -168,8 +235,11 @@ release_docs_spec: docs
 	$(INSTALL_DIR) "$(RELSYSDIR)/doc/pdf"
 	$(INSTALL_DATA) $(TOP_PDF_FILE) "$(RELSYSDIR)/doc/pdf"
 	$(INSTALL_DIR) "$(RELSYSDIR)/doc/html"
+	$(INSTALL_DIR) "$(RELSYSDIR)/doc/html/figures"
 	$(INSTALL_DATA) $(HTMLDIR)/* \
 		"$(RELSYSDIR)/doc/html"
+	$(INSTALL_DATA) $(XMLDIR)/figures/* \
+		"$(RELSYSDIR)/doc/html/figures"
 	$(INSTALL_DATA) $(ERL_TOP)/erts/example/time_compat.erl \
 		"$(RELSYSDIR)/doc/html"
 	$(INSTALL_DATA) $(ERL_TOP)/lib/kernel/examples/gen_tcp_dist/src/gen_tcp_dist.erl \
diff --git a/erts/doc/src/alt_disco.xml b/erts/doc/src/alt_disco.xml
index d04221b9b3..148d6f549e 100644
--- a/erts/doc/src/alt_disco.xml
+++ b/erts/doc/src/alt_disco.xml
@@ -63,7 +63,7 @@
     <seealso marker="kernel:erl_epmd">EPMD module</seealso>. However, instead of
     communicating with EPMD you can connect to any service to find out
     connection details of other nodes. A discovery module is enabled
-    by setting <seealso marker="erts:erl#epmd_module">-epmd_module</seealso>
+    by setting <seealso marker="erts:erl">-epmd_module</seealso>
     when starting erlang. The discovery module must implement the following
     callbacks:</p>
 
diff --git a/erts/doc/src/alt_dist.xml b/erts/doc/src/alt_dist.xml
index e6245130fc..f72e8acd2c 100644
--- a/erts/doc/src/alt_dist.xml
+++ b/erts/doc/src/alt_dist.xml
@@ -60,7 +60,7 @@
 	parts of the logic in Erlang code, and you perhaps do not
 	even need a new driver for the protocol. One example could
 	be Erlang distribution over UDP using <c>gen_udp</c> (your
-	Erlang code will of course have to take care of retranspissions,
+	Erlang code will of course have to take care of retransmissions,
 	etc in this example). That is, depending on what you want
 	to do you perhaps do not need to implement a driver at all
 	and can then skip the driver related sections below.
@@ -680,7 +680,10 @@
 	    of the distribution controller, <c>Received</c>
 	    is received packets, <c>Sent</c> is
 	    sent packets, and <c>PendSend</c> is
-	    amount of packets in queue to be sent
+	    amount of data in queue to be sent
+	    (typically in bytes, but <c>dist_util</c>
+	    only checks whether the value is non-zero
+	    to know there is data in queue)
 	    or a <c>boolean()</c> indicating whether
 	    there are packets in queue to be sent.
 	  </p>
diff --git a/erts/doc/src/atomics.xml b/erts/doc/src/atomics.xml
index 3fca92fb97..455973f011 100644
--- a/erts/doc/src/atomics.xml
+++ b/erts/doc/src/atomics.xml
@@ -23,14 +23,14 @@
 
     <title>atomics</title>
   </header>
-  <module>atomics</module>
+  <module since="OTP 21.2">atomics</module>
   <modulesummary>Atomic Functions</modulesummary>
   <description>
     <p>This module provides a set of functions to do atomic operations towards
     mutable atomic variables. The implementation utilizes only
     atomic hardware instructions without any software level locking, which makes
     it very efficient for concurrent access. The atomics are organized into
-    arrays with the follwing semantics:</p>
+    arrays with the following semantics:</p>
     <list type="bulleted">
       <item>
 	<p>Atomics are 64 bit integers.</p>
@@ -70,7 +70,7 @@
 
   <funcs>
     <func>
-      <name name="new" arity="2"/>
+      <name name="new" arity="2" since="OTP 21.2"/>
       <fsummary>Create atomic array</fsummary>
       <desc>
         <p>Create a new atomic array of <c><anno>Arity</anno></c> atomics.</p>
@@ -85,11 +85,13 @@
 	  bsl 64)-1</c>.</p>
 	  </item>
 	</taglist>
+        <p>Atomics are not tied to the current process and are automatically
+        garbage collected when they are no longer referenced.</p>
       </desc>
     </func>
 
     <func>
-      <name name="put" arity="3"/>
+      <name name="put" arity="3" since="OTP 21.2"/>
       <fsummary>Set atomic value</fsummary>
       <desc>
         <p>Set atomic to <c><anno>Value</anno></c>.</p>
@@ -97,7 +99,7 @@
     </func>
 
     <func>
-      <name name="get" arity="2"/>
+      <name name="get" arity="2" since="OTP 21.2"/>
       <fsummary>Read atomic value</fsummary>
       <desc>
         <p>Read atomic value.</p>
@@ -105,7 +107,7 @@
     </func>
 
     <func>
-      <name name="add" arity="3"/>
+      <name name="add" arity="3" since="OTP 21.2"/>
       <fsummary>Add to atomic</fsummary>
       <desc>
         <p>Add <c><anno>Incr</anno></c> to atomic.</p>
@@ -113,7 +115,7 @@
     </func>
 
     <func>
-      <name name="add_get" arity="3"/>
+      <name name="add_get" arity="3" since="OTP 21.2"/>
       <fsummary>Atomic add and get</fsummary>
       <desc>
         <p>Atomic addition and return of the result.</p>
@@ -121,7 +123,7 @@
     </func>
 
     <func>
-      <name name="sub" arity="3"/>
+      <name name="sub" arity="3" since="OTP 21.2"/>
       <fsummary>Subtract from atomic</fsummary>
       <desc>
         <p>Subtract <c><anno>Decr</anno></c> from atomic.</p>
@@ -129,7 +131,7 @@
     </func>
 
     <func>
-      <name name="sub_get" arity="3"/>
+      <name name="sub_get" arity="3" since="OTP 21.2"/>
       <fsummary>Atomic sub and get</fsummary>
       <desc>
         <p>Atomic subtraction and return of the result.</p>
@@ -137,7 +139,7 @@
     </func>
 
     <func>
-      <name name="exchange" arity="3"/>
+      <name name="exchange" arity="3" since="OTP 21.2"/>
       <fsummary>Atomic exchange.</fsummary>
       <desc>
         <p>Atomically replaces the value of the atomic with
@@ -147,7 +149,7 @@
     </func>
     
     <func>
-    <name name="compare_exchange" arity="4"/>
+    <name name="compare_exchange" arity="4" since="OTP 21.2"/>
        <fsummary>Atomic compare and exchange.</fsummary>
        <desc>
          <p>Atomically compares the atomic with <c><anno>Expected</anno></c>,
@@ -158,7 +160,7 @@
     </func>
     
     <func>
-      <name name="info" arity="1"/>
+      <name name="info" arity="1" since="OTP 21.2"/>
       <fsummary>Get information about atomic array.</fsummary>
       <desc>
         <p>Return information about an atomic array in a map. The map
diff --git a/erts/doc/src/book.xml b/erts/doc/src/book.xml
index a0780c91d9..d79da1e4f7 100644
--- a/erts/doc/src/book.xml
+++ b/erts/doc/src/book.xml
@@ -41,6 +41,9 @@
   <applications>
     <xi:include href="ref_man.xml"/>
   </applications>
+  <internals>
+    <xi:include href="internal.xml"/>
+  </internals>
   <releasenotes>
     <xi:include href="notes.xml"/>
   </releasenotes>
diff --git a/erts/doc/src/communication.xml b/erts/doc/src/communication.xml
index 7e18a73aa8..251b52dc65 100644
--- a/erts/doc/src/communication.xml
+++ b/erts/doc/src/communication.xml
@@ -64,7 +64,7 @@
     a synchronous communication operation consists of two asynchronous
     signals; one request signal and one reply signal. An example of
     such a synchronous communication is a call to
-    <seealso marker="erlang:process_info/2">
+    <seealso marker="erlang#process_info/2">
     <c>erlang:process_info/2</c></seealso>
     when the first argument is not <c>self()</c>. The caller sends
     an asynchronous signal requesting information, and then
diff --git a/erts/doc/src/counters.xml b/erts/doc/src/counters.xml
index ba4a22759f..36816bd68d 100644
--- a/erts/doc/src/counters.xml
+++ b/erts/doc/src/counters.xml
@@ -23,13 +23,13 @@
 
     <title>counters</title>
   </header>
-  <module>counters</module>
+  <module since="OTP 21.2">counters</module>
   <modulesummary>Counter Functions</modulesummary>
   <description>
     <p>This module provides a set of functions to do operations towards
     shared mutable counter variables. The implementation does not utilize any
     software level locking, which makes it very efficient for concurrent
-    access. The counters are organized into arrays with the follwing
+    access. The counters are organized into arrays with the following
     semantics:</p>
     <list type="bulleted">
       <item>
@@ -71,7 +71,7 @@
 
   <funcs>
     <func>
-      <name name="new" arity="2"/>
+      <name name="new" arity="2" since="OTP 21.2"/>
       <fsummary>Create counter array</fsummary>
       <desc>
         <p>Create a new counter array of <c><anno>Size</anno></c> counters.</p>
@@ -80,7 +80,7 @@
 	<taglist>
 	  <tag><c>atomics</c> (Default)</tag>
 	  <item><p>Counters will be sequentially consistent. If write
-	  operation A is done sequencially before write operation B, then a concurrent reader
+	  operation A is done sequentially before write operation B, then a concurrent reader
 	  may see none of them, only A, or both A and B. It cannot see only B.</p>
 	  </item>
 	  <tag><c>write_concurrency</c></tag>
@@ -90,7 +90,7 @@
 	  inconsistency and memory consumption per counter.</p>
 	  <p>Read operations may see sequentially inconsistent results with
 	  regard to concurrent write operations. Even if write operation A is done
-	  sequencially before write operation B, a concurrent reader may see any
+	  sequentially before write operation B, a concurrent reader may see any
 	  combination of A and B, including only B. A read operation is only
 	  guaranteed to see all writes done sequentially before the read. No writes
 	  are ever lost, but will eventually all be seen.</p>
@@ -103,11 +103,13 @@
 	  acceptable.</p>
 	  </item>
 	</taglist>
+        <p>Counters are not tied to the current process and are automatically
+        garbage collected when they are no longer referenced.</p>
       </desc>
     </func>
 
     <func>
-      <name name="get" arity="2"/>
+      <name name="get" arity="2" since="OTP 21.2"/>
       <fsummary>Read counter value</fsummary>
       <desc>
         <p>Read counter value.</p>
@@ -115,7 +117,7 @@
     </func>
 
     <func>
-      <name name="add" arity="3"/>
+      <name name="add" arity="3" since="OTP 21.2"/>
       <fsummary>Add to counter</fsummary>
       <desc>
         <p>Add <c><anno>Incr</anno></c> to counter at index
@@ -124,7 +126,7 @@
     </func>
 
     <func>
-      <name name="sub" arity="3"/>
+      <name name="sub" arity="3" since="OTP 21.2"/>
       <fsummary>Subtract from counter</fsummary>
       <desc>
         <p>Subtract <c><anno>Decr</anno></c> from counter at index
@@ -133,25 +135,25 @@
     </func>
 
     <func>
-      <name name="put" arity="3"/>
+      <name name="put" arity="3" since="OTP 21.2"/>
       <fsummary>Set counter to value</fsummary>
       <desc>
         <p>Write <c><anno>Value</anno></c> to counter at index
 	<c><anno>Ix</anno></c>.</p>
 	<note>
 	  <p>Despite its name, the <c>write_concurrency</c> optimization does not
-	  improve <c>put</c>. A call to <c>put</c> is a relative heavy
+	  improve <c>put</c>. A call to <c>put</c> is a relatively heavy
 	  operation compared to the very lightweight and scalable <seealso
 	  marker="#add/3"><c>add</c></seealso> and <seealso marker="#sub/3">
 	  <c>sub</c></seealso>. The cost for a <c>put</c> with
-	  <c>write_concurrency</c> is lika a <seealso marker="#get/2"><c>get</c>
+	  <c>write_concurrency</c> is like a <seealso marker="#get/2"><c>get</c>
 	  </seealso> plus a <c>put</c> without <c>write_concurrency</c>.</p>
 	</note>
       </desc>
     </func>
 
     <func>
-      <name name="info" arity="1"/>
+      <name name="info" arity="1" since="OTP 21.2"/>
       <fsummary>Get information about counter array.</fsummary>
       <desc>
         <p>Return information about a counter array in a map. The map
diff --git a/erts/doc/src/crash_dump.xml b/erts/doc/src/crash_dump.xml
index a9aeb1888c..876834307a 100644
--- a/erts/doc/src/crash_dump.xml
+++ b/erts/doc/src/crash_dump.xml
@@ -289,8 +289,8 @@ Slogan: &lt;reason&gt;</pre>
     <marker id="memory"></marker>
     <title>Memory Information</title>
     <p>Under the tag <em>=memory</em> is shown information similar
-      to what can be obtainted on a living node with
-      <seealso marker="erts:erlang#erlang:memory/0">
+      to what can be obtained on a living node with
+      <seealso marker="erts:erlang#memory/0">
       <c>erlang:memory()</c></seealso>.</p>
   </section>
 
diff --git a/erts/doc/src/driver.xml b/erts/doc/src/driver.xml
index 8f31df4cad..a873bf9931 100644
--- a/erts/doc/src/driver.xml
+++ b/erts/doc/src/driver.xml
@@ -391,7 +391,7 @@ void encode_result(ei_x_buff* x, PGresult* res, PGconn* conn)
     <p>Before a driver can be called from Erlang, it must be
       loaded and opened. Loading is done using the <c><![CDATA[erl_ddll]]></c>
       module (the <c><![CDATA[erl_ddll]]></c> driver that loads dynamic
-      driver is actually a driver itself). If loading is successfull,
+      driver is actually a driver itself). If loading is successful,
       the port can be opened with <c><![CDATA[open_port/2]]></c>. The port
       name must match the name of the shared library and
       the name in the driver entry structure.</p>
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index 05a9895687..ed1b0880b4 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -460,11 +460,14 @@
       <tag><c><![CDATA[-remsh Node]]></c></tag>
       <item>
         <p>Starts Erlang with a remote shell connected to
-          <c><![CDATA[Node]]></c>.</p>
+          <c><![CDATA[Node]]></c>. Requires either <c><![CDATA[-name]]></c>
+          or <c><![CDATA[-sname]]></c> to be given. If <c><![CDATA[Node]]></c>
+          does not contain a hostname, one is automatically taken from
+          <c><![CDATA[-name]]></c> or <c><![CDATA[-sname]]></c></p>
       </item>
       <tag><c><![CDATA[-rsh Program]]></c></tag>
       <item>
-        <p>Specifies an alternative to <c><![CDATA[rsh]]></c> for starting a
+        <p>Specifies an alternative to <c><![CDATA[ssh]]></c> for starting a
           slave node on a remote host; see
           <seealso marker="stdlib:slave"><c>slave(3)</c></seealso>.</p>
       </item>
@@ -636,6 +639,29 @@
           produces a crash dump. On Unix systems, sending an emulator process
           a <c>SIGUSR1</c> signal also forces a crash dump.</p>
       </item>
+      <tag><marker id="+dcg"/><c><![CDATA[+rg DecentralizedCounterGroupsLimit]]></c></tag>
+      <item>
+        <p>Limits the number of decentralized counter groups used by
+           decentralized counters optimized for update operations in the
+           Erlang runtime system. By default, the limit is 256.</p>
+        <p>When the number of schedulers is less than or equal to the
+           limit, each scheduler has its own group. When the
+           number of schedulers is larger than the groups limit,
+           schedulers share groups. Shared groups degrade
+           the performance for updating counters while many reader groups
+           degrade the performance for reading counters. So, the limit is a tradeoff
+           between performance for update operations and performance for
+           read operations. Each group consumes 64 bytes in each
+           counter.</p>
+        <p>Notice that a runtime system using decentralized
+           counter groups benefits from <seealso marker="#+sbt">binding
+           schedulers to logical processors</seealso>, as the groups are
+           distributed better between schedulers with this option.</p>
+        <p>This option only affects decentralized counters used for
+           the counters that are keeping track of the memory consumption
+           and the number of terms in ETS tables of type ordered_set with
+           the write_concurrency option activated.</p>
+      </item>
       <tag><marker id="+e"/><c><![CDATA[+e Number]]></c></tag>
       <item>
         <p>Sets the maximum number of ETS tables. This limit is
diff --git a/erts/doc/src/erl_dist_protocol.xml b/erts/doc/src/erl_dist_protocol.xml
index c90c8f9521..f924c8a70b 100644
--- a/erts/doc/src/erl_dist_protocol.xml
+++ b/erts/doc/src/erl_dist_protocol.xml
@@ -532,11 +532,7 @@ io:format("old/unused name ~ts at port ~p, fd = ~p ~n",
     <marker id="distribution_handshake"/>
     <title>Distribution Handshake</title>
     <p>This section describes the distribution handshake protocol introduced
-      in Erlang/OTP R6. This description was previously located in
-      <c>$ERL_TOP/lib/kernel/internal_doc/distribution_handshake.txt</c> and
-      has more or less been copied and "formatted" here. It has been almost
-      unchanged since 1999, but the handshake has not changed much since then
-      either.</p>
+      in Erlang/OTP R6. The handshake has remained almost the same since then.</p>
 
     <section>
       <title>General</title>
@@ -847,6 +843,23 @@ DiB == gen_digest(ChA, ICA)?
 	    of the <c>SEND_TT</c> control message.
 	  </p>
         </item>
+        <tag><c>-define(DFLAG_BIG_SEQTRACE_LABELS, 16#100000).</c></tag>
+        <item>
+          <p>The node understands any term as the seqtrace label.</p>
+        </item>
+        <tag><c>-define(DFLAG_EXIT_PAYLOAD, 16#400000).</c></tag>
+        <item>
+          <p>Use the <c>PAYLOAD_EXIT</c>, <c>PAYLOAD_EXIT_TT</c>,
+            <c>PAYLOAD_EXIT2</c>, <c>PAYLOAD_EXIT2_TT</c>
+            and <c>PAYLOAD_MONITOR_P_EXIT</c>
+            <seealso marker="#control_message">control message</seealso>s
+            instead of the non-PAYLOAD variants.</p>
+        </item>
+        <tag><c>-define(DFLAG_FRAGMENTS, 16#800000).</c></tag>
+        <item>
+          <p>Use <seealso marker="erl_ext_dist#fragments">fragmented</seealso>
+            distribution messages to send large messages.</p>
+        </item>
       </taglist>
       <p>
 	There is also function <c>dist_util:strict_order_flags/0</c>
@@ -859,7 +872,7 @@ DiB == gen_digest(ChA, ICA)?
   <section>
     <marker id="connected_nodes"/>
     <title>Protocol between Connected Nodes</title>
-    <p>As from ERTS 5.7.2 the runtime system passes a distribution flag
+    <p>Since ERTS 5.7.2 (OTP R13B) the runtime system passes a distribution flag
       in the handshake stage that enables the use of a
       <seealso marker="erl_ext_dist#distribution_header">distribution header
       </seealso> on all messages passed. Messages passed between nodes have in
@@ -878,7 +891,7 @@ DiB == gen_digest(ChA, ICA)?
         <cell align="center"><c>ControlMessage</c></cell>
         <cell align="center"><c>Message</c></cell>
       </row>
-      <tcaption>Format of Messages Passed between Nodes (as from ERTS 5.7.2)
+      <tcaption>Format of Messages Passed between Nodes (as from ERTS 5.7.2 (OTP R13B))
       </tcaption>
     </table>
 
@@ -887,15 +900,23 @@ DiB == gen_digest(ChA, ICA)?
       <item>
         <p>Equal to d + n + m.</p>
       </item>
+      <tag><c>DistributionHeader</c></tag>
+      <item>
+        <p>
+          <seealso marker="erl_ext_dist#distribution_header">Distribution header
+          describing the atom cache and fragmented distribution messages.
+          </seealso>
+        </p>
+      </item>
       <tag><c>ControlMessage</c></tag>
       <item>
         <p>A tuple passed using the external format of Erlang.</p>
       </item>
       <tag><c>Message</c></tag>
       <item>
-        <p>The message sent to another node using the '!' (in external format).
-          Notice that <c>Message</c> is only passed in combination with a
-          <c>ControlMessage</c> encoding a send ('!').</p>
+        <p>The message sent to another node using the '!'
+          or the reason for a EXIT, EXIT2 or DOWN signal using
+          the external term format.</p>
       </item>
     </taglist>
 
@@ -903,7 +924,7 @@ DiB == gen_digest(ChA, ICA)?
       number is omitted from the terms that follow a distribution header
       </seealso>.</p>
 
-    <p>Nodes with an ERTS version earlier than 5.7.2 does not pass the
+    <p>Nodes with an ERTS version earlier than 5.7.2 (OTP R13B) does not pass the
       distribution flag that enables the distribution header. Messages passed
       between nodes have in this case the following format:</p>
 
@@ -920,7 +941,7 @@ DiB == gen_digest(ChA, ICA)?
         <cell align="center"><c>ControlMessage</c></cell>
         <cell align="center"><c>Message</c></cell>
       </row>
-      <tcaption>Format of Messages Passed between Nodes (before ERTS 5.7.2)
+      <tcaption>Format of Messages Passed between Nodes (before ERTS 5.7.2 (OTP R13B))
       </tcaption>
     </table>
 
@@ -963,6 +984,7 @@ DiB == gen_digest(ChA, ICA)?
       <tag><c>EXIT</c></tag>
       <item>
         <p><c>{3, FromPid, ToPid, Reason}</c></p>
+        <p>This signal is sent when a link has been broken</p>
       </item>
       <tag><c>UNLINK</c></tag>
       <item>
@@ -985,6 +1007,7 @@ DiB == gen_digest(ChA, ICA)?
       <tag><c>EXIT2</c></tag>
       <item>
         <p><c>{8, FromPid, ToPid, Reason}</c></p>
+        <p>This signal is sent by a call to the erlang:exit/2 bif</p>
       </item>
     </taglist>
   </section>
@@ -1007,7 +1030,7 @@ DiB == gen_digest(ChA, ICA)?
         <p><c>{16, FromPid, Unused, ToName, TraceToken}</c></p>
         <p>Followed by <c>Message</c>.</p>
         <p><c>Unused</c> is kept for backward compatibility.</p>
-      </item>      
+      </item>
       <tag><c>EXIT2_TT</c></tag>
       <item>
         <p><c>{18, FromPid, ToPid, TraceToken, Reason}</c></p>
@@ -1061,7 +1084,7 @@ DiB == gen_digest(ChA, ICA)?
         <p><c>{22, FromPid, ToPid}</c></p>
         <p>Followed by <c>Message</c>.</p>
 	<p>
-	  This control messages replace the <c>SEND</c> control
+	  This control message replaces the <c>SEND</c> control
 	  message and will be sent when the distribution flag
 	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_SEND_SENDER</c></seealso>
 	  has been negotiated in the connection setup handshake.
@@ -1080,7 +1103,7 @@ DiB == gen_digest(ChA, ICA)?
         <p><c>{23, FromPid, ToPid, TraceToken}</c></p>
         <p>Followed by <c>Message</c>.</p>
 	<p>
-	  This control messages replace the <c>SEND_TT</c> control
+	  This control message replaces the <c>SEND_TT</c> control
 	  message and will be sent when the distribution flag
 	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_SEND_SENDER</c></seealso>
 	  has been negotiated in the connection setup handshake.
@@ -1097,4 +1120,72 @@ DiB == gen_digest(ChA, ICA)?
     </taglist>
   </section>
 
+  <section>
+    <title>New Ctrlmessages for Erlang/OTP 22</title>
+    <note><p>
+      Messages encoded before the connection has
+      been set up may still use the non-PAYLOAD variant.
+      However, once a PAYLOAD control message has been sent,
+      no more non-PAYLOAD control messages will be sent in
+      the same direction on the connection.
+    </p></note>
+    <taglist>
+      <tag><c>PAYLOAD_EXIT</c></tag>
+      <item>
+        <p><c>{24, FromPid, ToPid}</c></p>
+        <p>Followed by <c>Reason</c>.</p>
+	<p>
+	  This control message replaces the <c>EXIT</c> control
+	  message and will be sent when the distribution flag
+	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_EXIT_PAYLOAD</c></seealso>
+	  has been negotiated in the connection setup handshake.
+	</p>
+      </item>
+      <tag><c>PAYLOAD_EXIT_TT</c></tag>
+      <item>
+        <p><c>{25, FromPid, ToPid}</c></p>
+        <p>Followed by <c>Reason</c>.</p>
+	<p>
+	  This control message replaces the <c>EXIT_TT</c> control
+	  message and will be sent when the distribution flag
+	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_EXIT_PAYLOAD</c></seealso>
+	  has been negotiated in the connection setup handshake.
+	</p>
+      </item>
+      <tag><c>PAYLOAD_EXIT2</c></tag>
+      <item>
+        <p><c>{26, FromPid, ToPid}</c></p>
+        <p>Followed by <c>Reason</c>.</p>
+	<p>
+	  This control message replaces the <c>EXIT2</c> control
+	  message and will be sent when the distribution flag
+	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_EXIT_PAYLOAD</c></seealso>
+	  has been negotiated in the connection setup handshake.
+	</p>
+      </item>
+      <tag><c>PAYLOAD_EXIT2_TT</c></tag>
+      <item>
+        <p><c>{27, FromPid, ToPid}</c></p>
+        <p>Followed by <c>Reason</c>.</p>
+	<p>
+	  This control message replaces the <c>EXIT2_TT</c> control
+	  message and will be sent when the distribution flag
+	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_EXIT_PAYLOAD</c></seealso>
+	  has been negotiated in the connection setup handshake.
+	</p>
+      </item>
+      <tag><c>PAYLOAD_MONITOR_P_EXIT</c></tag>
+      <item>
+        <p><c>{28, FromPid, ToPid, Ref}</c></p>
+        <p>Followed by <c>Reason</c>.</p>
+	<p>
+	  This control message replaces the <c>MONITOR_P_EXIT</c> control
+	  message and will be sent when the distribution flag
+	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_EXIT_PAYLOAD</c></seealso>
+	  has been negotiated in the connection setup handshake.
+	</p>
+      </item>
+    </taglist>
+  </section>
+
 </chapter>
diff --git a/erts/doc/src/erl_driver.xml b/erts/doc/src/erl_driver.xml
index 7055889e4a..3e2d3bb447 100644
--- a/erts/doc/src/erl_driver.xml
+++ b/erts/doc/src/erl_driver.xml
@@ -230,7 +230,7 @@
       <item>
         <p>With these functions, the driver sends data back to the emulator.
           The data is received as messages by the port owner process, see
-          <seealso marker="erlang:open_port/2">
+          <seealso marker="erlang#open_port/2">
           <c>erlang:open_port/2</c></seealso>. The vector function and the
           function taking a driver binary are faster, as they avoid
           copying the data buffer. There is also a fast way of sending
@@ -944,7 +944,7 @@ int suggested_stack_size;</code>
 
   <funcs>
     <func>
-      <name><ret>void</ret><nametext>add_driver_entry(ErlDrvEntry
+      <name since=""><ret>void</ret><nametext>add_driver_entry(ErlDrvEntry
         *de)</nametext></name>
       <fsummary>Add a driver entry.</fsummary>
       <desc>
@@ -968,7 +968,7 @@ int suggested_stack_size;</code>
     </func>
 
     <func>
-      <name><ret>void *</ret>
+      <name since=""><ret>void *</ret>
         <nametext>driver_alloc(ErlDrvSizeT size)</nametext></name>
       <fsummary>Allocate memory.</fsummary>
       <desc>
@@ -985,7 +985,7 @@ int suggested_stack_size;</code>
     </func>
 
     <func>
-      <name><ret>ErlDrvBinary *</ret>
+      <name since=""><ret>ErlDrvBinary *</ret>
         <nametext>driver_alloc_binary(ErlDrvSizeT size)</nametext></name>
       <fsummary>Allocate a driver binary.</fsummary>
       <desc>
@@ -1008,7 +1008,7 @@ int suggested_stack_size;</code>
     </func>
 
     <func>
-      <name><ret>long</ret><nametext>driver_async(ErlDrvPort port, unsigned
+      <name since=""><ret>long</ret><nametext>driver_async(ErlDrvPort port, unsigned
         int* key, void (*async_invoke)(void*), void* async_data, void
         (*async_free)(void*))</nametext></name>
       <fsummary>Perform an asynchronous call within a driver.</fsummary>
@@ -1076,7 +1076,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>unsigned int</ret><nametext>driver_async_port_key(ErlDrvPort
+      <name since="OTP R16B02"><ret>unsigned int</ret><nametext>driver_async_port_key(ErlDrvPort
         port)</nametext></name>
       <fsummary>Calculate an async key from an ErlDrvPort.</fsummary>
       <desc>
@@ -1096,7 +1096,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>long</ret>
+      <name since=""><ret>long</ret>
         <nametext>driver_binary_dec_refc(ErlDrvBinary *bin)</nametext></name>
       <fsummary>Decrement the reference count of a driver binary.</fsummary>
       <desc>
@@ -1117,7 +1117,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>long</ret>
+      <name since=""><ret>long</ret>
         <nametext>driver_binary_get_refc(ErlDrvBinary *bin)</nametext></name>
       <fsummary>Get the reference count of a driver binary.</fsummary>
       <desc>
@@ -1128,7 +1128,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>long</ret>
+      <name since=""><ret>long</ret>
         <nametext>driver_binary_inc_refc(ErlDrvBinary *bin)</nametext></name>
       <fsummary>Increment the reference count of a driver binary.</fsummary>
       <desc>
@@ -1140,7 +1140,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvTermData</ret><nametext>driver_caller(ErlDrvPort
+      <name since=""><ret>ErlDrvTermData</ret><nametext>driver_caller(ErlDrvPort
         port)</nametext></name>
       <fsummary>Return the process making the driver call.</fsummary>
       <desc>
@@ -1154,27 +1154,27 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
         <taglist>
           <tag><seealso marker="driver_entry#start">
             <c>start</c></seealso></tag>
-          <item>Called from <seealso marker="erlang:open_port/2">
+          <item>Called from <seealso marker="erlang#open_port/2">
             <c>erlang:open_port/2</c></seealso>.</item>
           <tag><seealso marker="driver_entry#output">
             <c>output</c></seealso></tag>
-          <item>Called from <seealso marker="erlang:send/2">
+          <item>Called from <seealso marker="erlang#send/2">
             <c>erlang:send/2</c></seealso> and
-            <seealso marker="erlang:port_command/2">
+            <seealso marker="erlang#port_command/2">
             <c>erlang:port_command/2</c></seealso>.</item>
           <tag><seealso marker="driver_entry#outputv">
             <c>outputv</c></seealso></tag>
-          <item>Called from <seealso marker="erlang:send/2">
+          <item>Called from <seealso marker="erlang#send/2">
             <c>erlang:send/2</c></seealso> and
-            <seealso marker="erlang:port_command/2">
+            <seealso marker="erlang#port_command/2">
             <c>erlang:port_command/2</c></seealso>.</item>
           <tag><seealso marker="driver_entry#control">
             <c>control</c></seealso></tag>
-          <item>Called from <seealso marker="erlang:port_control/3">
+          <item>Called from <seealso marker="erlang#port_control/3">
             <c>erlang:port_control/3</c></seealso>.</item>
           <tag><seealso marker="driver_entry#call">
             <c>call</c></seealso></tag>
-          <item>Called from <seealso marker="erlang:port_call/3">
+          <item>Called from <seealso marker="erlang#port_call/3">
             <c>erlang:port_call/3</c></seealso>.</item>
         </taglist>
         <p>Notice that this function is <em>not</em> thread-safe, not
@@ -1183,7 +1183,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since=""><ret>int</ret>
         <nametext>driver_cancel_timer(ErlDrvPort port)</nametext></name>
       <fsummary>Cancel a previously set timer.</fsummary>
       <desc>
@@ -1196,7 +1196,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_compare_monitors(const ErlDrvMonitor
+      <name since=""><ret>int</ret><nametext>driver_compare_monitors(const ErlDrvMonitor
         *monitor1, const ErlDrvMonitor *monitor2)</nametext></name>
       <fsummary>Compare two monitors.</fsummary>
       <desc>
@@ -1211,7 +1211,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvTermData</ret><nametext>driver_connected(ErlDrvPort
+      <name since=""><ret>ErlDrvTermData</ret><nametext>driver_connected(ErlDrvPort
         port)</nametext></name>
       <fsummary>Return the port owner process.</fsummary>
       <desc>
@@ -1223,7 +1223,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvPort</ret><nametext>driver_create_port(ErlDrvPort port,
+      <name since=""><ret>ErlDrvPort</ret><nametext>driver_create_port(ErlDrvPort port,
         ErlDrvTermData owner_pid, char* name,
         ErlDrvData drv_data)</nametext></name>
       <fsummary>Create a new port (driver instance).</fsummary>
@@ -1269,7 +1269,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_demonitor_process(ErlDrvPort port,
+      <name since=""><ret>int</ret><nametext>driver_demonitor_process(ErlDrvPort port,
         const ErlDrvMonitor *monitor)</nametext></name>
       <fsummary>Stop monitoring a process from a driver.</fsummary>
       <desc>
@@ -1281,7 +1281,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvSizeT</ret><nametext>driver_deq(ErlDrvPort port,
+      <name since=""><ret>ErlDrvSizeT</ret><nametext>driver_deq(ErlDrvPort port,
         ErlDrvSizeT size)</nametext></name>
       <fsummary>Dequeue data from the head of the driver queue.</fsummary>
       <desc>
@@ -1299,7 +1299,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_enq(ErlDrvPort port, char* buf,
+      <name since=""><ret>int</ret><nametext>driver_enq(ErlDrvPort port, char* buf,
         ErlDrvSizeT len)</nametext></name>
       <fsummary>Enqueue data in the driver queue.</fsummary>
       <desc>
@@ -1325,7 +1325,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_enq_bin(ErlDrvPort port,
+      <name since=""><ret>int</ret><nametext>driver_enq_bin(ErlDrvPort port,
         ErlDrvBinary *bin, ErlDrvSizeT offset, ErlDrvSizeT len)</nametext>
       </name>
       <fsummary>Enqueue binary in the driver queue.</fsummary>
@@ -1346,7 +1346,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_enqv(ErlDrvPort port, ErlIOVec *ev,
+      <name since=""><ret>int</ret><nametext>driver_enqv(ErlDrvPort port, ErlIOVec *ev,
         ErlDrvSizeT skip)</nametext></name>
       <fsummary>Enqueue vector in the driver queue.</fsummary>
       <desc>
@@ -1365,11 +1365,11 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_failure(ErlDrvPort port, int
+      <name since=""><ret>int</ret><nametext>driver_failure(ErlDrvPort port, int
         error)</nametext></name>
-      <name><ret>int</ret><nametext>driver_failure_atom(ErlDrvPort port, char
+      <name since=""><ret>int</ret><nametext>driver_failure_atom(ErlDrvPort port, char
         *string)</nametext></name>
-      <name><ret>int</ret><nametext>driver_failure_posix(ErlDrvPort port, int
+      <name since=""><ret>int</ret><nametext>driver_failure_posix(ErlDrvPort port, int
         error)</nametext></name>
       <fsummary>Fail with error.</fsummary>
       <desc>
@@ -1393,7 +1393,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_failure_eof(ErlDrvPort
+      <name since=""><ret>int</ret><nametext>driver_failure_eof(ErlDrvPort
         port)</nametext></name>
       <fsummary>Fail with EOF.</fsummary>
       <desc>
@@ -1408,7 +1408,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>driver_free(void *ptr)</nametext></name>
+      <name since=""><ret>void</ret><nametext>driver_free(void *ptr)</nametext></name>
       <fsummary>Free an allocated memory block.</fsummary>
       <desc>
         <marker id="driver_free"></marker>
@@ -1422,7 +1422,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since=""><ret>void</ret>
         <nametext>driver_free_binary(ErlDrvBinary *bin)</nametext></name>
       <fsummary>Free a driver binary.</fsummary>
       <desc>
@@ -1436,7 +1436,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvTermData</ret>
+      <name since=""><ret>ErlDrvTermData</ret>
         <nametext>driver_get_monitored_process(ErlDrvPort port, const
         ErlDrvMonitor *monitor)</nametext></name>
       <fsummary>Retrieve the process ID from a monitor.</fsummary>
@@ -1452,7 +1452,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since=""><ret>int</ret>
         <nametext>driver_get_now(ErlDrvNowData *now)</nametext></name>
       <fsummary>Read a system time stamp.</fsummary>
       <desc>
@@ -1473,7 +1473,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_lock_driver(ErlDrvPort
+      <name since=""><ret>int</ret><nametext>driver_lock_driver(ErlDrvPort
         port)</nametext></name>
       <fsummary>Ensure the driver is never unloaded.</fsummary>
       <desc>
@@ -1486,7 +1486,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvTermData</ret><nametext>driver_mk_atom(char*
+      <name since=""><ret>ErlDrvTermData</ret><nametext>driver_mk_atom(char*
         string)</nametext></name>
       <fsummary>Make an atom from a name.</fsummary>
       <desc>
@@ -1501,7 +1501,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvTermData</ret><nametext>driver_mk_port(ErlDrvPort
+      <name since=""><ret>ErlDrvTermData</ret><nametext>driver_mk_port(ErlDrvPort
         port)</nametext></name>
       <fsummary>Make an Erlang term port from a port.</fsummary>
       <desc>
@@ -1517,7 +1517,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_monitor_process(ErlDrvPort port,
+      <name since=""><ret>int</ret><nametext>driver_monitor_process(ErlDrvPort port,
         ErlDrvTermData process, ErlDrvMonitor *monitor)</nametext></name>
       <fsummary>Monitor a process from a driver.</fsummary>
       <desc>
@@ -1540,7 +1540,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_output(ErlDrvPort port, char *buf,
+      <name since=""><ret>int</ret><nametext>driver_output(ErlDrvPort port, char *buf,
         ErlDrvSizeT len)</nametext></name>
       <fsummary>Send data from driver to port owner.</fsummary>
       <desc>
@@ -1560,7 +1560,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_output_binary(ErlDrvPort port, char
+      <name since=""><ret>int</ret><nametext>driver_output_binary(ErlDrvPort port, char
         *hbuf, ErlDrvSizeT hlen, ErlDrvBinary* bin, ErlDrvSizeT offset,
         ErlDrvSizeT len)</nametext></name>
       <fsummary>Send data from a driver binary to port owner.</fsummary>
@@ -1589,7 +1589,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_output_term(ErlDrvPort port,
+      <name since=""><ret>int</ret><nametext>driver_output_term(ErlDrvPort port,
         ErlDrvTermData* term, int n)</nametext></name>
       <fsummary>Send term data from driver to port owner.</fsummary>
       <desc>
@@ -1608,7 +1608,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_output2(ErlDrvPort port, char *hbuf,
+      <name since=""><ret>int</ret><nametext>driver_output2(ErlDrvPort port, char *hbuf,
         ErlDrvSizeT hlen, char *buf, ErlDrvSizeT len)</nametext></name>
       <fsummary>Send data and binary data to port owner.</fsummary>
       <desc>
@@ -1625,7 +1625,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_outputv(ErlDrvPort port, char* hbuf,
+      <name since=""><ret>int</ret><nametext>driver_outputv(ErlDrvPort port, char* hbuf,
         ErlDrvSizeT hlen, ErlIOVec *ev, ErlDrvSizeT skip)</nametext></name>
       <fsummary>Send vectorized data to port owner.</fsummary>
       <desc>
@@ -1654,7 +1654,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvPDL</ret>
+      <name since=""><ret>ErlDrvPDL</ret>
         <nametext>driver_pdl_create(ErlDrvPort port)</nametext></name>
       <fsummary>Create a port data lock.</fsummary>
       <desc>
@@ -1672,7 +1672,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>long</ret><nametext>driver_pdl_dec_refc(ErlDrvPDL
+      <name since=""><ret>long</ret><nametext>driver_pdl_dec_refc(ErlDrvPDL
         pdl)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -1686,7 +1686,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>long</ret>
+      <name since=""><ret>long</ret>
         <nametext>driver_pdl_get_refc(ErlDrvPDL pdl)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -1698,7 +1698,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>long</ret>
+      <name since=""><ret>long</ret>
         <nametext>driver_pdl_inc_refc(ErlDrvPDL pdl)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -1712,7 +1712,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since=""><ret>void</ret>
         <nametext>driver_pdl_lock(ErlDrvPDL pdl)</nametext></name>
       <fsummary>Lock port data lock.</fsummary>
       <desc>
@@ -1723,7 +1723,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since=""><ret>void</ret>
         <nametext>driver_pdl_unlock(ErlDrvPDL pdl)</nametext></name>
       <fsummary>Unlock port data lock.</fsummary>
       <desc>
@@ -1734,7 +1734,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>SysIOVec *</ret><nametext>driver_peekq(ErlDrvPort port, int
+      <name since=""><ret>SysIOVec *</ret><nametext>driver_peekq(ErlDrvPort port, int
         *vlen)</nametext></name>
       <fsummary>Get the driver queue as a vector.</fsummary>
       <desc>
@@ -1755,7 +1755,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvSizeT</ret><nametext>driver_peekqv(ErlDrvPort port,
+      <name since="OTP R15B"><ret>ErlDrvSizeT</ret><nametext>driver_peekqv(ErlDrvPort port,
         ErlIOVec *ev)</nametext></name>
       <fsummary>Get the driver queue as an I/O vector.</fsummary>
       <desc>
@@ -1775,7 +1775,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_pushq(ErlDrvPort port, char* buf,
+      <name since=""><ret>int</ret><nametext>driver_pushq(ErlDrvPort port, char* buf,
         ErlDrvSizeT len)</nametext></name>
       <fsummary>Push data at the head of the driver queue.</fsummary>
       <desc>
@@ -1792,7 +1792,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_pushq_bin(ErlDrvPort port,
+      <name since=""><ret>int</ret><nametext>driver_pushq_bin(ErlDrvPort port,
         ErlDrvBinary *bin, ErlDrvSizeT offset, ErlDrvSizeT len)</nametext>
       </name>
       <fsummary>Push binary at the head of the driver queue.</fsummary>
@@ -1812,7 +1812,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_pushqv(ErlDrvPort port, ErlIOVec
+      <name since=""><ret>int</ret><nametext>driver_pushqv(ErlDrvPort port, ErlIOVec
         *ev, ErlDrvSizeT skip)</nametext></name>
       <fsummary>Push vector at the head of the driver queue.</fsummary>
       <desc>
@@ -1831,7 +1831,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_read_timer(ErlDrvPort port, unsigned
+      <name since=""><ret>int</ret><nametext>driver_read_timer(ErlDrvPort port, unsigned
         long *time_left)</nametext></name>
       <fsummary>Read the time left before time-out.</fsummary>
       <desc>
@@ -1844,7 +1844,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void *</ret>
+      <name since=""><ret>void *</ret>
         <nametext>driver_realloc(void *ptr, ErlDrvSizeT size)</nametext></name>
       <fsummary>Resize an allocated memory block.</fsummary>
       <desc>
@@ -1859,7 +1859,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvBinary *</ret>
+      <name since=""><ret>ErlDrvBinary *</ret>
         <nametext>driver_realloc_binary(ErlDrvBinary *bin, ErlDrvSizeT size)
         </nametext></name>
       <fsummary>Resize a driver binary.</fsummary>
@@ -1873,7 +1873,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_select(ErlDrvPort port, ErlDrvEvent
+      <name since=""><ret>int</ret><nametext>driver_select(ErlDrvPort port, ErlDrvEvent
         event, int mode, int on)</nametext></name>
       <fsummary>Provides an event for having the emulator call the driver.
       </fsummary>
@@ -1932,7 +1932,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_send_term(ErlDrvPort port,
+      <name since=""><ret>int</ret><nametext>driver_send_term(ErlDrvPort port,
         ErlDrvTermData receiver, ErlDrvTermData* term, int n)</nametext></name>
       <fsummary>Send term data to other process than port owner process.
       </fsummary>
@@ -1958,7 +1958,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>driver_set_timer(ErlDrvPort port, unsigned
+      <name since=""><ret>int</ret><nametext>driver_set_timer(ErlDrvPort port, unsigned
         long time)</nametext></name>
       <fsummary>Set a timer to call the driver.</fsummary>
       <desc>
@@ -1977,7 +1977,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvSizeT</ret>
+      <name since=""><ret>ErlDrvSizeT</ret>
         <nametext>driver_sizeq(ErlDrvPort port)</nametext></name>
       <fsummary>Return the size of the driver queue.</fsummary>
       <desc>
@@ -1991,7 +1991,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>driver_system_info(ErlDrvSysInfo
+      <name since=""><ret>void</ret><nametext>driver_system_info(ErlDrvSysInfo
         *sys_info_ptr, size_t size)</nametext></name>
       <fsummary>Get information about the Erlang runtime system.</fsummary>
       <desc>
@@ -2008,7 +2008,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvSizeT</ret><nametext>driver_vec_to_buf(ErlIOVec *ev,
+      <name since=""><ret>ErlDrvSizeT</ret><nametext>driver_vec_to_buf(ErlIOVec *ev,
         char *buf, ErlDrvSizeT len)</nametext></name>
       <fsummary>Collect data segments into a buffer.</fsummary>
       <desc>
@@ -2029,7 +2029,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_busy_msgq_limits(ErlDrvPort port,
+      <name since="OTP R16B"><ret>void</ret><nametext>erl_drv_busy_msgq_limits(ErlDrvPort port,
         ErlDrvSizeT *low, ErlDrvSizeT *high)</nametext></name>
       <fsummary>Set and get limits for busy port message queue.</fsummary>
       <desc>
@@ -2083,7 +2083,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_cond_broadcast(ErlDrvCond
+      <name since=""><ret>void</ret><nametext>erl_drv_cond_broadcast(ErlDrvCond
         *cnd)</nametext></name>
       <fsummary>Broadcast on a condition variable.</fsummary>
       <desc>
@@ -2097,7 +2097,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvCond *</ret><nametext>erl_drv_cond_create(char
+      <name since=""><ret>ErlDrvCond *</ret><nametext>erl_drv_cond_create(char
         *name)</nametext></name>
       <fsummary>Create a condition variable.</fsummary>
       <desc>
@@ -2114,7 +2114,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_cond_destroy(ErlDrvCond
+      <name since=""><ret>void</ret><nametext>erl_drv_cond_destroy(ErlDrvCond
         *cnd)</nametext></name>
       <fsummary>Destroy a condition variable.</fsummary>
       <desc>
@@ -2128,7 +2128,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>char *</ret><nametext>erl_drv_cond_name(ErlDrvCond
+      <name since="OTP R16B02"><ret>char *</ret><nametext>erl_drv_cond_name(ErlDrvCond
         *cnd)</nametext></name>
       <fsummary>Get name of driver mutex.</fsummary>
       <desc>
@@ -2142,7 +2142,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_cond_signal(ErlDrvCond
+      <name since=""><ret>void</ret><nametext>erl_drv_cond_signal(ErlDrvCond
         *cnd)</nametext></name>
       <fsummary>Signal on a condition variable.</fsummary>
       <desc>
@@ -2156,7 +2156,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_cond_wait(ErlDrvCond *cnd,
+      <name since=""><ret>void</ret><nametext>erl_drv_cond_wait(ErlDrvCond *cnd,
         ErlDrvMutex *mtx)</nametext></name>
       <fsummary>Wait on a condition variable.</fsummary>
       <desc>
@@ -2185,7 +2185,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_consume_timeslice(ErlDrvPort port,
+      <name since="OTP R16B"><ret>int</ret><nametext>erl_drv_consume_timeslice(ErlDrvPort port,
         int percent)</nametext></name>
       <fsummary>Give the runtime system a hint about how much CPU time the
         current driver callback call has consumed.</fsummary>
@@ -2228,7 +2228,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvTime</ret><nametext>erl_drv_convert_time_unit(ErlDrvTime
+      <name since="OTP 18.3"><ret>ErlDrvTime</ret><nametext>erl_drv_convert_time_unit(ErlDrvTime
         val, ErlDrvTimeUnit from, ErlDrvTimeUnit to)</nametext></name>
       <fsummary>Convert time unit of a time value.</fsummary>
       <desc>
@@ -2254,7 +2254,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_equal_tids(ErlDrvTid tid1,
+      <name since=""><ret>int</ret><nametext>erl_drv_equal_tids(ErlDrvTid tid1,
         ErlDrvTid tid2)</nametext></name>
       <fsummary>Compare thread identifiers for equality.</fsummary>
       <desc>
@@ -2276,7 +2276,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_getenv(const char *key, char
+      <name since=""><ret>int</ret><nametext>erl_drv_getenv(const char *key, char
         *value, size_t *value_size)</nametext></name>
       <fsummary>Get the value of an environment variable.</fsummary>
       <desc>
@@ -2305,7 +2305,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
           <c>*value_size</c> has been set to the buffer size needed.</p>
         <warning>
           <p>This function reads the emulated environment used by
-            <seealso marker="os:getenv/1"><c>os:getenv/1</c></seealso> and not
+            <seealso marker="kernel:os#getenv/1"><c>os:getenv/1</c></seealso> and not
             the environment used by libc's <c>getenv(3)</c> or similar. Drivers
             that <em>require</em> that these are in sync will need to do so
             themselves, but keep in mind that they are segregated for a reason;
@@ -2317,7 +2317,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_init_ack(ErlDrvPort port,
+      <name since="OTP 19.0"><ret>void</ret><nametext>erl_drv_init_ack(ErlDrvPort port,
         ErlDrvData res)</nametext></name>
       <fsummary>Acknowledge the start of the port.</fsummary>
       <desc>
@@ -2345,7 +2345,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvTime</ret>
+      <name since="OTP 18.3"><ret>ErlDrvTime</ret>
         <nametext>erl_drv_monotonic_time(ErlDrvTimeUnit time_unit)</nametext>
       </name>
       <fsummary>Get Erlang monotonic time.</fsummary>
@@ -2365,7 +2365,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>ErlDrvMutex *</ret><nametext>erl_drv_mutex_create(char
+      <name since=""><ret>ErlDrvMutex *</ret><nametext>erl_drv_mutex_create(char
         *name)</nametext></name>
       <fsummary>Create a mutex.</fsummary>
       <desc>
@@ -2380,7 +2380,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_mutex_destroy(ErlDrvMutex
+      <name since=""><ret>void</ret><nametext>erl_drv_mutex_destroy(ErlDrvMutex
         *mtx)</nametext></name>
       <fsummary>Destroy a mutex.</fsummary>
       <desc>
@@ -2395,7 +2395,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_mutex_lock(ErlDrvMutex
+      <name since=""><ret>void</ret><nametext>erl_drv_mutex_lock(ErlDrvMutex
         *mtx)</nametext></name>
       <fsummary>Lock a mutex.</fsummary>
       <desc>
@@ -2414,7 +2414,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>char *</ret><nametext>erl_drv_mutex_name(ErlDrvMutex
+      <name since="OTP R16B02"><ret>char *</ret><nametext>erl_drv_mutex_name(ErlDrvMutex
         *mtx)</nametext></name>
       <fsummary>Get name of driver mutex.</fsummary>
       <desc>
@@ -2428,7 +2428,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_mutex_trylock(ErlDrvMutex
+      <name since=""><ret>int</ret><nametext>erl_drv_mutex_trylock(ErlDrvMutex
         *mtx)</nametext></name>
       <fsummary>Try lock a mutex.</fsummary>
       <desc>
@@ -2447,7 +2447,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_mutex_unlock(ErlDrvMutex
+      <name since=""><ret>void</ret><nametext>erl_drv_mutex_unlock(ErlDrvMutex
         *mtx)</nametext></name>
       <fsummary>Unlock a mutex.</fsummary>
       <desc>
@@ -2460,7 +2460,7 @@ r = driver_async(myPort, &myKey, myData, myFunc);    ]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_output_term(ErlDrvTermData port,
+      <name since="OTP R16B"><ret>int</ret><nametext>erl_drv_output_term(ErlDrvTermData port,
         ErlDrvTermData* term, int n)</nametext></name>
       <fsummary>Send term data from driver to port owner.</fsummary>
       <desc>
@@ -2637,7 +2637,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_putenv(const char *key, char
+      <name since=""><ret>int</ret><nametext>erl_drv_putenv(const char *key, char
         *value)</nametext></name>
       <fsummary>Set the value of an environment variable.</fsummary>
       <desc>
@@ -2656,7 +2656,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
         </note>
         <warning>
           <p>This function modifies the emulated environment used by
-            <seealso marker="os:putenv/2"><c>os:putenv/2</c></seealso> and not
+            <seealso marker="kernel:os#putenv/2"><c>os:putenv/2</c></seealso> and not
             the environment used by libc's <c>putenv(3)</c> or similar. Drivers
             that <em>require</em> that these are in sync will need to do so
             themselves, but keep in mind that they are segregated for a reason;
@@ -2668,7 +2668,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>ErlDrvRWLock *</ret><nametext>erl_drv_rwlock_create(char
+      <name since=""><ret>ErlDrvRWLock *</ret><nametext>erl_drv_rwlock_create(char
         *name)</nametext></name>
       <fsummary>Create an rwlock.</fsummary>
       <desc>
@@ -2684,7 +2684,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_rwlock_destroy(ErlDrvRWLock
+      <name since=""><ret>void</ret><nametext>erl_drv_rwlock_destroy(ErlDrvRWLock
         *rwlck)</nametext></name>
       <fsummary>Destroy an rwlock.</fsummary>
       <desc>
@@ -2699,7 +2699,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>char *</ret><nametext>erl_drv_rwlock_name(ErlDrvRWLock
+      <name since="OTP R16B02"><ret>char *</ret><nametext>erl_drv_rwlock_name(ErlDrvRWLock
         *rwlck)</nametext></name>
       <fsummary>Get name of driver mutex.</fsummary>
       <desc>
@@ -2713,7 +2713,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_rwlock_rlock(ErlDrvRWLock
+      <name since=""><ret>void</ret><nametext>erl_drv_rwlock_rlock(ErlDrvRWLock
         *rwlck)</nametext></name>
       <fsummary>Read lock an rwlock.</fsummary>
       <desc>
@@ -2733,7 +2733,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_rwlock_runlock(ErlDrvRWLock
+      <name since=""><ret>void</ret><nametext>erl_drv_rwlock_runlock(ErlDrvRWLock
         *rwlck)</nametext></name>
       <fsummary>Read unlock an rwlock.</fsummary>
       <desc>
@@ -2746,7 +2746,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_rwlock_rwlock(ErlDrvRWLock
+      <name since=""><ret>void</ret><nametext>erl_drv_rwlock_rwlock(ErlDrvRWLock
         *rwlck)</nametext></name>
       <fsummary>Read/write lock an rwlock.</fsummary>
       <desc>
@@ -2766,7 +2766,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_rwlock_rwunlock(ErlDrvRWLock
+      <name since=""><ret>void</ret><nametext>erl_drv_rwlock_rwunlock(ErlDrvRWLock
         *rwlck)</nametext></name>
       <fsummary>Read/write unlock an rwlock.</fsummary>
       <desc>
@@ -2779,7 +2779,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_rwlock_tryrlock(ErlDrvRWLock
+      <name since=""><ret>int</ret><nametext>erl_drv_rwlock_tryrlock(ErlDrvRWLock
         *rwlck)</nametext></name>
       <fsummary>Try to read lock an rwlock.</fsummary>
       <desc>
@@ -2799,7 +2799,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_rwlock_tryrwlock(ErlDrvRWLock
+      <name since=""><ret>int</ret><nametext>erl_drv_rwlock_tryrwlock(ErlDrvRWLock
         *rwlck)</nametext></name>
       <fsummary>Try to read/write lock an rwlock.</fsummary>
       <desc>
@@ -2819,7 +2819,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_send_term(ErlDrvTermData port,
+      <name since="OTP R16B"><ret>int</ret><nametext>erl_drv_send_term(ErlDrvTermData port,
         ErlDrvTermData receiver, ErlDrvTermData* term, int n)</nametext></name>
       <fsummary>Send term data to other process than port owner process.
       </fsummary>
@@ -2843,13 +2843,13 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_set_os_pid(ErlDrvPort port,
+      <name since="OTP 19.0"><ret>void</ret><nametext>erl_drv_set_os_pid(ErlDrvPort port,
         ErlDrvSInt pid)</nametext></name>
       <fsummary>Set the os_pid for the port.</fsummary>
       <desc>
         <marker id="erl_drv_set_os_pid"></marker>
         <p>Sets the <c>os_pid</c> seen when doing
-          <seealso marker="erlang:port_info/2">
+          <seealso marker="erlang#port_info/2">
           <c>erlang:port_info/2</c></seealso> on this port.</p>
         <p><c>port</c> is the port handle of the port (driver instance) to set
           the pid on. <c>pid</c>is the pid to set.</p>
@@ -2857,7 +2857,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_thread_create(char *name, ErlDrvTid
+      <name since=""><ret>int</ret><nametext>erl_drv_thread_create(char *name, ErlDrvTid
         *tid, void * (*func)(void *), void *arg, ErlDrvThreadOpts
         *opts)</nametext></name>
       <fsummary>Create a thread.</fsummary>
@@ -2920,7 +2920,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_thread_exit(void
+      <name since=""><ret>void</ret><nametext>erl_drv_thread_exit(void
         *exit_value)</nametext></name>
       <fsummary>Terminate calling thread.</fsummary>
       <desc>
@@ -2939,7 +2939,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_thread_join(ErlDrvTid tid, void
+      <name since=""><ret>int</ret><nametext>erl_drv_thread_join(ErlDrvTid tid, void
         **exit_value)</nametext></name>
       <fsummary>Join with another thread.</fsummary>
       <desc>
@@ -2962,7 +2962,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>char *</ret><nametext>erl_drv_thread_name(ErlDrvTid
+      <name since="OTP R16B02"><ret>char *</ret><nametext>erl_drv_thread_name(ErlDrvTid
         tid)</nametext></name>
       <fsummary>Get name of driver mutex.</fsummary>
       <desc>
@@ -2976,7 +2976,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>ErlDrvThreadOpts *</ret>
+      <name since=""><ret>ErlDrvThreadOpts *</ret>
         <nametext>erl_drv_thread_opts_create(char *name)</nametext></name>
       <fsummary>Create thread options.</fsummary>
       <desc>
@@ -3005,7 +3005,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since=""><ret>void</ret>
         <nametext>erl_drv_thread_opts_destroy(ErlDrvThreadOpts *opts)</nametext>
       </name>
       <fsummary>Destroy thread options.</fsummary>
@@ -3020,7 +3020,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>ErlDrvTid</ret>
+      <name since=""><ret>ErlDrvTid</ret>
         <nametext>erl_drv_thread_self(void)</nametext></name>
       <fsummary>Get the thread identifier of the current thread.</fsummary>
       <desc>
@@ -3031,7 +3031,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>ErlDrvTime</ret><nametext>erl_drv_time_offset(ErlDrvTimeUnit
+      <name since="OTP 18.3"><ret>ErlDrvTime</ret><nametext>erl_drv_time_offset(ErlDrvTimeUnit
         time_unit)</nametext></name>
       <fsummary>Get current time offset.</fsummary>
       <desc>
@@ -3054,7 +3054,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void *</ret><nametext>erl_drv_tsd_get(ErlDrvTSDKey
+      <name since=""><ret>void *</ret><nametext>erl_drv_tsd_get(ErlDrvTSDKey
         key)</nametext></name>
       <fsummary>Get thread-specific data.</fsummary>
       <desc>
@@ -3069,7 +3069,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>erl_drv_tsd_key_create(char *name,
+      <name since=""><ret>int</ret><nametext>erl_drv_tsd_key_create(char *name,
         ErlDrvTSDKey *key)</nametext></name>
       <fsummary>Create a thread-specific data key.</fsummary>
       <desc>
@@ -3086,7 +3086,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_tsd_key_destroy(ErlDrvTSDKey
+      <name since=""><ret>void</ret><nametext>erl_drv_tsd_key_destroy(ErlDrvTSDKey
         key)</nametext></name>
       <fsummary>Destroy a thread-specific data key.</fsummary>
       <desc>
@@ -3111,7 +3111,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>erl_drv_tsd_set(ErlDrvTSDKey key, void
+      <name since=""><ret>void</ret><nametext>erl_drv_tsd_set(ErlDrvTSDKey key, void
         *data)</nametext></name>
       <fsummary>Set thread-specific data.</fsummary>
       <desc>
@@ -3138,7 +3138,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>char *</ret><nametext>erl_errno_id(int error)</nametext></name>
+      <name since=""><ret>char *</ret><nametext>erl_errno_id(int error)</nametext></name>
       <fsummary>Get Erlang error atom name from error number.</fsummary>
       <desc>
         <marker id="erl_errno_id"></marker>
@@ -3150,7 +3150,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>remove_driver_entry(ErlDrvEntry
+      <name since=""><ret>int</ret><nametext>remove_driver_entry(ErlDrvEntry
         *de)</nametext></name>
       <fsummary>Remove a driver entry.</fsummary>
       <desc>
@@ -3164,7 +3164,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>set_busy_port(ErlDrvPort port, int
+      <name since=""><ret>void</ret><nametext>set_busy_port(ErlDrvPort port, int
         on)</nametext></name>
       <fsummary>Signal or unsignal port as busy.</fsummary>
       <desc>
@@ -3195,7 +3195,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>set_port_control_flags(ErlDrvPort port,
+      <name since=""><ret>void</ret><nametext>set_port_control_flags(ErlDrvPort port,
         int flags)</nametext></name>
       <fsummary>Set flags on how to handle control entry function.</fsummary>
       <desc>
@@ -3204,7 +3204,7 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
           <c>control</c></seealso> driver entry
           function will return data to the port owner process.
           (The <c>control</c> function is called from
-          <seealso marker="erlang:port_control/3">
+          <seealso marker="erlang#port_control/3">
           <c>erlang:port_control/3</c></seealso>.)</p>
         <p>Currently there are only two meaningful values for
           <c>flags</c>: <c>0</c> means that data is returned in a list,
diff --git a/erts/doc/src/erl_ext_dist.xml b/erts/doc/src/erl_ext_dist.xml
index b7090d0472..2ba5994557 100644
--- a/erts/doc/src/erl_ext_dist.xml
+++ b/erts/doc/src/erl_ext_dist.xml
@@ -128,7 +128,7 @@
 	are deprecated and are only kept for backward
 	compatibility when decoding terms encoded by older nodes.</p>
       <p>Support for UTF-8 encoded atoms in the external format has been
-        available since ERTS 5.10 (OTP R16). This abillity allows such old nodes
+        available since ERTS 5.10 (OTP R16). This ability allows such old nodes
 	to decode, store and encode any Unicode atoms received from a new OTP 20
         node.</p>
       <p>The maximum number of allowed characters in an atom is 255. In the
@@ -136,172 +136,370 @@
     </note>
   </section>
 
-  <section>  
+  <section>
+    <marker id="distribution_header"/>
     <title>Distribution Header</title>
     <p>
-      <marker id="distribution_header"/>
-      As from ERTS 5.7.2 the old atom cache protocol was
-      dropped and a new one was introduced. This protocol
-      introduced the distribution header. Nodes with an ERTS version
-      earlier than 5.7.2 can still communicate with new nodes,
-      but no distribution header and no atom cache are used.</p>
-    <p>
-      The distribution header only contains an atom cache
-      reference section, but can in the future contain more
-      information. The distribution header precedes one or more Erlang
-      terms on the external format. For more information, see the
-      documentation of the
+      The distribution header is sent by the erlang distribution to
+      carry metadata about the coming
+      <seealso marker="erl_dist_protocol#control_message">control message</seealso>
+      and potential payload. It is primarily used to handle the atom cache
+      in the Erlang distribution. Since OTP-22 it is also used to fragment
+      large distribution messages into multiple smaller fragments.
+      For more information about how the distribution uses the distribution header,
+      see the documentation of the
       <seealso marker="erl_dist_protocol#connected_nodes">protocol between
       connected nodes</seealso> in the
       <seealso marker="erl_dist_protocol">distribution protocol</seealso>
       documentation.
     </p>
     <p>
-      <seealso marker="#ATOM_CACHE_REF">ATOM_CACHE_REF</seealso>
+      Any <seealso marker="#ATOM_CACHE_REF">ATOM_CACHE_REF</seealso>
       entries with corresponding <c>AtomCacheReferenceIndex</c> in terms
       encoded on the external format following a distribution header refer
       to the atom cache references made in the distribution header. The range
       is 0 &lt;= <c>AtomCacheReferenceIndex</c> &lt; 255, that is, at most 255
       different atom cache references from the following terms can be made.
     </p>
-    <p>
-      The distribution header format is as follows:
-    </p>
-    <table align="left">
-      <row>
-        <cell align="center">1</cell>
-        <cell align="center">1</cell>
-        <cell align="center">1</cell>
-        <cell align="center">NumberOfAtomCacheRefs/2+1 | 0</cell>
-        <cell align="center">N | 0</cell>
-      </row>
-      <row>
-        <cell align="center"><c>131</c></cell>
-        <cell align="center"><c>68</c></cell>
-        <cell align="center"><c>NumberOfAtomCacheRefs</c></cell>
-        <cell align="center"><c>Flags</c></cell>
-        <cell align="center"><c>AtomCacheRefs</c></cell>
-      </row>
-    <tcaption>Distribution Header Format</tcaption></table>
-    <p>
-      <c>Flags</c> consist of <c>NumberOfAtomCacheRefs/2+1</c> bytes,
-      unless <c>NumberOfAtomCacheRefs</c> is <c>0</c>. If
-      <c>NumberOfAtomCacheRefs</c> is <c>0</c>, <c>Flags</c> and
-      <c>AtomCacheRefs</c> are omitted. Each atom cache reference has
-      a half byte flag field. Flags corresponding to a specific
-      <c>AtomCacheReferenceIndex</c> are located in flag byte number
-      <c>AtomCacheReferenceIndex/2</c>. Flag byte 0 is the first byte
-      after the <c>NumberOfAtomCacheRefs</c> byte. Flags for an even
-      <c>AtomCacheReferenceIndex</c> are located in the least significant
-      half byte and flags for an odd <c>AtomCacheReferenceIndex</c> are
-      located in the most significant half byte.
-    </p>
-    <p>
-      The flag field of an atom cache reference has the following
-      format:
-    </p>
-    <table align="left">
-      <row>
-        <cell align="center">1 bit</cell>
-        <cell align="center">3 bits</cell>
-      </row>
-      <row>
-        <cell align="center"><c>NewCacheEntryFlag</c></cell>
-        <cell align="center"><c>SegmentIndex</c></cell>
-      </row>
-    <tcaption></tcaption></table>
-    <p>
-      The most significant bit is the <c>NewCacheEntryFlag</c>. If set,
-      the corresponding cache reference is new. The three least
-      significant bits are the <c>SegmentIndex</c> of the corresponding
-      atom cache entry. An atom cache consists of 8 segments, each of size
-      256, that is, an atom cache can contain 2048 entries.
-    </p>
-    <p>
-      After flag fields for atom cache references, another half byte flag
-      field is located with the following format:
-    </p>
-    <table align="left">
-      <row>
-        <cell align="center">3 bits</cell>
-        <cell align="center">1 bit</cell>
-      </row>
-      <row>
-        <cell align="center"><c>CurrentlyUnused</c></cell>
-        <cell align="center"><c>LongAtoms</c></cell>
-      </row>
-    <tcaption></tcaption></table>
-    <p>
-      The least significant bit in that half byte is flag <c>LongAtoms</c>.
-      If it is set, 2 bytes are used for atom lengths instead of
-      1 byte in the distribution header.
-    </p>
-    <p>
-      After the <c>Flags</c> field follow the <c>AtomCacheRefs</c>. The
-      first <c>AtomCacheRef</c> is the one corresponding to
-      <c>AtomCacheReferenceIndex</c> 0. Higher indices follow
-      in sequence up to index <c>NumberOfAtomCacheRefs - 1</c>.
-    </p>
-    <p>
-      If the <c>NewCacheEntryFlag</c> for the next <c>AtomCacheRef</c> has
-      been set, a <c>NewAtomCacheRef</c> on the following format follows:
-    </p>
-    <table align="left">
-      <row>
-        <cell align="center">1</cell>
-        <cell align="center">1 | 2</cell>
-        <cell align="center">Length</cell>
-      </row>
-      <row>
-        <cell align="center"><c>InternalSegmentIndex</c></cell>
-        <cell align="center"><c>Length</c></cell>
-        <cell align="center"><c>AtomText</c></cell>
-      </row>
-    <tcaption></tcaption></table>
-    <p>
-      <c>InternalSegmentIndex</c> together with the <c>SegmentIndex</c>
-      completely identify the location of an atom cache entry in the
-      atom cache. <c>Length</c> is the number of bytes that <c>AtomText</c>
-      consists of. Length is a 2 byte big-endian integer
-      if flag <c>LongAtoms</c> has been set, otherwise a 1 byte
-      integer. When distribution flag
-      <seealso marker="erl_dist_protocol#dflags">
-      <c>DFLAG_UTF8_ATOMS</c></seealso>
-      has been exchanged between both nodes in the
-      <seealso marker="erl_dist_protocol#distribution_handshake">
-      distribution handshake</seealso>,
-      characters in <c>AtomText</c> are encoded in UTF-8, otherwise
-      in Latin-1. The following <c>CachedAtomRef</c>s with the same
-      <c>SegmentIndex</c> and <c>InternalSegmentIndex</c> as this
-      <c>NewAtomCacheRef</c> refer to this atom until a new
-      <c>NewAtomCacheRef</c> with the same <c>SegmentIndex</c>
-      and <c>InternalSegmentIndex</c> appear.
-    </p>
-    <p>
-      For more information on encoding of atoms, see the
-      <seealso marker="#utf8_atoms">note on UTF-8 encoded atoms</seealso>
-      in the beginning of this section.
-    </p>
-    <p>
-      If the <c>NewCacheEntryFlag</c> for the next <c>AtomCacheRef</c>
-      has not been set, a <c>CachedAtomRef</c> on the following format
-      follows:
-    </p>
-    <table align="left">
-      <row>
-        <cell align="center">1</cell>
-      </row>
-      <row>
-        <cell align="center"><c>InternalSegmentIndex</c></cell>
-      </row>
-    <tcaption></tcaption></table>
-    <p>
-      <c>InternalSegmentIndex</c> together with the <c>SegmentIndex</c>
-      identify the location of the atom cache entry in the atom cache.
-      The atom corresponding to this <c>CachedAtomRef</c> is the
-      latest <c>NewAtomCacheRef</c> preceding this <c>CachedAtomRef</c>
-      in another previously passed distribution header.
-    </p>
+    <section>
+      <title>Normal Distribution Header</title>
+      <p>
+        The non-fragmented distribution header format is as follows:
+      </p>
+      <table align="left">
+        <row>
+          <cell align="center">1</cell>
+          <cell align="center">1</cell>
+          <cell align="center">1</cell>
+          <cell align="center">NumberOfAtomCacheRefs/2+1 | 0</cell>
+          <cell align="center">N | 0</cell>
+        </row>
+        <row>
+          <cell align="center"><c>131</c></cell>
+          <cell align="center"><c>68</c></cell>
+          <cell align="center"><c>NumberOfAtomCacheRefs</c></cell>
+          <cell align="center"><c>Flags</c></cell>
+          <cell align="center"><c>AtomCacheRefs</c></cell>
+        </row>
+      <tcaption>Normal Distribution Header Format</tcaption></table>
+      <p>
+        <c>Flags</c> consist of <c>NumberOfAtomCacheRefs/2+1</c> bytes,
+        unless <c>NumberOfAtomCacheRefs</c> is <c>0</c>. If
+        <c>NumberOfAtomCacheRefs</c> is <c>0</c>, <c>Flags</c> and
+        <c>AtomCacheRefs</c> are omitted. Each atom cache reference has
+        a half byte flag field. Flags corresponding to a specific
+        <c>AtomCacheReferenceIndex</c> are located in flag byte number
+        <c>AtomCacheReferenceIndex/2</c>. Flag byte 0 is the first byte
+        after the <c>NumberOfAtomCacheRefs</c> byte. Flags for an even
+        <c>AtomCacheReferenceIndex</c> are located in the least significant
+        half byte and flags for an odd <c>AtomCacheReferenceIndex</c> are
+        located in the most significant half byte.
+      </p>
+      <p>
+        The flag field of an atom cache reference has the following
+        format:
+      </p>
+      <table align="left">
+        <row>
+          <cell align="center">1 bit</cell>
+          <cell align="center">3 bits</cell>
+        </row>
+        <row>
+          <cell align="center"><c>NewCacheEntryFlag</c></cell>
+          <cell align="center"><c>SegmentIndex</c></cell>
+        </row>
+      <tcaption></tcaption></table>
+      <p>
+        The most significant bit is the <c>NewCacheEntryFlag</c>. If set,
+        the corresponding cache reference is new. The three least
+        significant bits are the <c>SegmentIndex</c> of the corresponding
+        atom cache entry. An atom cache consists of 8 segments, each of size
+        256, that is, an atom cache can contain 2048 entries.
+      </p>
+      <p>
+        After flag fields for atom cache references, another half byte flag
+        field is located with the following format:
+      </p>
+      <table align="left">
+        <row>
+          <cell align="center">3 bits</cell>
+          <cell align="center">1 bit</cell>
+        </row>
+        <row>
+          <cell align="center"><c>CurrentlyUnused</c></cell>
+          <cell align="center"><c>LongAtoms</c></cell>
+        </row>
+      <tcaption></tcaption></table>
+      <p>
+        The least significant bit in that half byte is flag <c>LongAtoms</c>.
+        If it is set, 2 bytes are used for atom lengths instead of
+        1 byte in the distribution header.
+      </p>
+      <p>
+        After the <c>Flags</c> field follow the <c>AtomCacheRefs</c>. The
+        first <c>AtomCacheRef</c> is the one corresponding to
+        <c>AtomCacheReferenceIndex</c> 0. Higher indices follow
+        in sequence up to index <c>NumberOfAtomCacheRefs - 1</c>.
+      </p>
+      <p>
+        If the <c>NewCacheEntryFlag</c> for the next <c>AtomCacheRef</c> has
+        been set, a <c>NewAtomCacheRef</c> on the following format follows:
+      </p>
+      <table align="left">
+        <row>
+          <cell align="center">1</cell>
+          <cell align="center">1 | 2</cell>
+          <cell align="center">Length</cell>
+        </row>
+        <row>
+          <cell align="center"><c>InternalSegmentIndex</c></cell>
+          <cell align="center"><c>Length</c></cell>
+          <cell align="center"><c>AtomText</c></cell>
+        </row>
+      <tcaption></tcaption></table>
+      <p>
+        <c>InternalSegmentIndex</c> together with the <c>SegmentIndex</c>
+        completely identify the location of an atom cache entry in the
+        atom cache. <c>Length</c> is the number of bytes that <c>AtomText</c>
+        consists of. Length is a 2 byte big-endian integer
+        if flag <c>LongAtoms</c> has been set, otherwise a 1 byte
+        integer. When distribution flag
+        <seealso marker="erl_dist_protocol#dflags">
+        <c>DFLAG_UTF8_ATOMS</c></seealso>
+        has been exchanged between both nodes in the
+        <seealso marker="erl_dist_protocol#distribution_handshake">
+          distribution handshake</seealso>,
+          characters in <c>AtomText</c> are encoded in UTF-8, otherwise
+          in Latin-1. The following <c>CachedAtomRef</c>s with the same
+          <c>SegmentIndex</c> and <c>InternalSegmentIndex</c> as this
+          <c>NewAtomCacheRef</c> refer to this atom until a new
+          <c>NewAtomCacheRef</c> with the same <c>SegmentIndex</c>
+          and <c>InternalSegmentIndex</c> appear.
+      </p>
+      <p>
+        For more information on encoding of atoms, see the
+        <seealso marker="#utf8_atoms">note on UTF-8 encoded atoms</seealso>
+        in the beginning of this section.
+      </p>
+      <p>
+        If the <c>NewCacheEntryFlag</c> for the next <c>AtomCacheRef</c>
+        has not been set, a <c>CachedAtomRef</c> on the following format
+        follows:
+      </p>
+      <table align="left">
+        <row>
+          <cell align="center">1</cell>
+        </row>
+        <row>
+          <cell align="center"><c>InternalSegmentIndex</c></cell>
+        </row>
+      <tcaption></tcaption></table>
+      <p>
+        <c>InternalSegmentIndex</c> together with the <c>SegmentIndex</c>
+        identify the location of the atom cache entry in the atom cache.
+        The atom corresponding to this <c>CachedAtomRef</c> is the
+        latest <c>NewAtomCacheRef</c> preceding this <c>CachedAtomRef</c>
+        in another previously passed distribution header.
+      </p>
+    </section>
+    <section>
+      <marker id="fragments"/>
+      <title>Distribution Header for fragmented messages</title>
+      <p>Messages sent between Erlang nodes can sometimes be
+      quite large. Since OTP-22 it is possible to split large messages
+      into smaller fragments in order to allow smaller messages to be interleaved
+      between larges messages. It is only the <c>message</c> part of each
+      <seealso marker="erl_dist_protocol#connected_nodes">distributed message</seealso>
+      that may be split using fragmentation. Therefore it is recommended to use the
+      <seealso marker="erl_dist_protocol#new-ctrlmessages-for-erlang-otp-22">
+        PAYLOAD control messages</seealso> introduced in OTP-22.
+      </p>
+      <p>Fragmented distribution messages are only used if the receiving node
+      signals that it supports them via the
+      <seealso marker="erl_dist_protocol#dflags">DFLAG_FRAGMENTS</seealso> distribution
+      flag.</p>
+      <p>A process must complete the sending of a fragmented message before it
+      can start sending any other message on the same distribution channel.</p>
+
+      <p>The start of a sequence of fragmented messages looks like this:</p>
+      <table align="left">
+        <row>
+          <cell align="center">1</cell>
+          <cell align="center">1</cell>
+          <cell align="center">8</cell>
+          <cell align="center">8</cell>
+          <cell align="center">1</cell>
+          <cell align="center">NumberOfAtomCacheRefs/2+1 | 0</cell>
+          <cell align="center">N | 0</cell>
+        </row>
+        <row>
+          <cell align="center"><c>131</c></cell>
+          <cell align="center"><c>69</c></cell>
+          <cell align="center"><c>SequenceId</c></cell>
+          <cell align="center"><c>FragmentId</c></cell>
+          <cell align="center"><c>NumberOfAtomCacheRefs</c></cell>
+          <cell align="center"><c>Flags</c></cell>
+          <cell align="center"><c>AtomCacheRefs</c></cell>
+        </row>
+        <tcaption>Starting Fragmented Distribution Header Format</tcaption>
+      </table>
+
+      <p>The continuation of a sequence of fragmented messages looks like this:</p>
+      <table align="left">
+        <row>
+          <cell align="center">1</cell>
+          <cell align="center">1</cell>
+          <cell align="center">8</cell>
+          <cell align="center">8</cell>
+        </row>
+        <row>
+          <cell align="center"><c>131</c></cell>
+          <cell align="center"><c>70</c></cell>
+          <cell align="center"><c>SequenceId</c></cell>
+          <cell align="center"><c>FragmentId</c></cell>
+        </row>
+        <tcaption>Continuing Fragmented Distribution Header Format</tcaption>
+      </table>
+
+      <p>
+        The starting distribution header is very similar to a non-fragmented distribution
+        header. The atom cache works the same as for normal distribution header and
+        is the same for the entire sequence. The additional fields added are the
+        sequence id and fragment id.
+      </p>
+
+      <taglist>
+        <tag>Sequence ID</tag>
+        <item>
+          <p>
+            The sequence id is used to uniquely identify a fragmented message sent
+            from one process to another on the same distributed connection. This is used
+            to identify which sequence a fragment is a part of as the same process can
+            be in the process of receiving multiple sequences at the same time.
+          </p>
+          <p>
+            As one process can only be sending one fragmented message at once,
+            it can be convenient to use the local PID as the sequence id.
+          </p>
+        </item>
+        <tag>Fragments ID</tag>
+        <item>
+          <p>
+            The Fragment ID is used to number the fragments in a sequence.
+            The id starts at the total number of fragments and then decrements to 1
+            (which is the final fragment). So if a sequence consists of 3 fragments
+            the fragment id in the starting header will be 3, and then fragments 2 and 1
+            are sent.
+          </p>
+          <p>
+            The fragments must be delivered in the correct order, so if an unordered
+            distribution carrier is used, they must be ordered before delivered to the
+            Erlang run-time.
+          </p>
+        </item>
+      </taglist>
+
+      <section>
+        <title>Example:</title>
+        <p>
+          As an example, let say that we want to send
+          <c>{call, &lt;0.245.2>, {set_get_state, &lt;&lt;0:1024>>}}</c> to
+          registered process <c>reg</c> using a fragment size of 128. To send
+          this message we need a distribution header, atom cache updates,
+          the control message (which would be <c>{6, &lt;0.245.2>, [], reg}</c> in this case)
+          and finally the actual message. This would all be encoded into:
+        </p>
+
+        <code>
+131,69,0,0,2,168,0,0,5,83,0,0,0,0,0,0,0,2,               %% Header with seq and frag id
+5,4,137,9,10,5,236,3,114,101,103,9,4,99,97,108,108,      %% Atom cache updates
+238,13,115,101,116,95,103,101,116,95,115,116,97,116,101,
+104,4,97,6,103,82,0,0,0,0,85,0,0,0,0,2,82,1,82,2,        %% Control message
+104,3,82,3,103,82,0,0,0,0,245,0,0,0,2,2,                 %% Actual message using cached atoms
+104,2,82,4,109,0,0,0,128,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+
+131,70,0,0,2,168,0,0,5,83,0,0,0,0,0,0,0,1,               %% Cont Header with seq and frag id
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,               %% Rest of payload
+0,0,0,0</code>
+
+       <p>
+         Let us break that apart into its components. First we have the
+         distribution header tags together with the sequence id and
+         a fragment id of 2.
+       </p>
+       <code>
+131,69,                   %% Start fragment header
+0,0,2,168,0,0,5,83,       %% The sequence ID
+0,0,0,0,0,0,0,2,           %% The fragment ID
+</code>
+       <p>Then we have the updates to the atom cache:</p>
+       <code>
+5,4,137,9,  %% 5 atoms and their flags
+10,5,       %% The already cached atom ids
+236,3,114,101,103,  %% The atom 'reg'
+9,4,99,97,108,108,  %% The atom 'call'
+238,13,115,101,116,95,103,101,116,95,115,116,97,116,101, %% The atom 'set_get_state'
+       </code>
+       <p>
+         The first byte says that we have 5 atoms that are part
+         of the cache. Then follows three bytes that are the
+         atom cache ref flags. Each of the flags uses 4 bits so
+         they are a bit hard to read in decimal byte form. In
+         binary half-byte form they look like this:
+       </p>
+       <code>0000, 0100, 1000, 1001, 1001</code>
+       <p>
+         As the high bit of the first two atoms in the
+         cache are not set we know that they are already in the cache,
+         so they do not have to be sent again (this is the node name of the
+         receiving and sending node). Then follows the atoms that have to be sent,
+         together with their segment ids.
+       </p>
+       <p>
+         Then the listing of the atoms comes, starting with 10 and 5
+         which are the atom refs of the already cached atoms. Then the
+         new atoms are sent.
+       </p>
+       <p>
+         When the atom cache is setup correctly the control message is sent.
+       </p>
+       <code>104,4,97,6,103,82,0,0,0,0,85,0,0,0,0,2,82,1,82,2,</code>
+       <p>
+         Note that up until here it is not allowed to fragments the message.
+         The entire atom cache and control message has to be part of the
+         starting fragment. After the control message the payload of the message
+         is sent using 128 bytes:
+       </p>
+       <code>
+104,3,82,3,103,82,0,0,0,0,245,0,0,0,2,2,
+104,2,82,4,109,0,0,0,128,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+       </code>
+       <p>
+         Since the payload is larger than 128-bytes it is split into two
+         fragments. The second fragment does not have any atom cache update
+         instructions so it is a lot simpler:
+       </p>
+       <code>
+131,70,0,0,2,168,0,0,5,83,0,0,0,0,0,0,0,1, %% Continuation dist header 70 with seq and frag id
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, %% remaining payload
+0,0,0,0
+       </code>
+       <note>
+         <p>
+           The fragment size of 128 is only used as an example.
+           Any fragments size may be used when sending fragmented messages.
+         </p>
+       </note>
+      </section>
+    </section>
   </section>
 
   <section>
@@ -373,8 +571,9 @@
       </row>
     <tcaption>FLOAT_EXT</tcaption></table>
     <p>
-      A float is stored in string format. The format used in sprintf to
-      format the float is "%.20e"
+      A finite float (i.e. not inf, -inf or NaN) is stored in
+      string format. The format used in sprintf to format the
+      float is "%.20e"
       (there are more bytes allocated than necessary).
       To unpack the float, use sscanf with format "%lf".
     </p>
@@ -386,44 +585,6 @@
   </section>
 
     <section>
-      <marker id="REFERENCE_EXT"/>
-      <title>REFERENCE_EXT</title>
-      <table align="left">
-        <row>
-          <cell align="center">1</cell>
-          <cell align="center">N</cell>
-          <cell align="center">4</cell>
-          <cell align="center">1</cell>
-        </row>
-        <row>
-          <cell align="center"><c>101</c></cell>
-          <cell align="center"><c>Node</c></cell>
-          <cell align="center"><c>ID</c></cell>
-          <cell align="center"><c>Creation</c></cell>
-        </row>
-      <tcaption>REFERENCE_EXT</tcaption></table>
-      <p>
-        Encodes a reference object (an object generated with
-        <seealso marker="erlang:make_ref/0">erlang:make_ref/0</seealso>).
-        The <c>Node</c> term is an encoded atom, that is,
-        <seealso marker="#ATOM_UTF8_EXT"><c>ATOM_UTF8_EXT</c></seealso>, 
-        <seealso marker="#SMALL_ATOM_UTF8_EXT"><c>SMALL_ATOM_UTF8_EXT</c></seealso>, or
-        <seealso marker="#ATOM_CACHE_REF"><c>ATOM_CACHE_REF</c></seealso>. 
-        The <c>ID</c> field contains a big-endian unsigned integer,
-        but <em>is to be regarded as uninterpreted data</em>,
-        as this field is node-specific.
-        <c>Creation</c> is a byte containing a node serial number, which
-        makes it possible to separate old (crashed) nodes from a new one.
-      </p>
-      <p>
-        In <c>ID</c>, only 18 bits are significant; the rest are to be 0.
-        In <c>Creation</c>, only two bits are significant; the rest are to be 0.
-        See <seealso marker="#NEW_REFERENCE_EXT">
-        <c>NEW_REFERENCE_EXT</c></seealso>.
-      </p>
-    </section>
-
-    <section>
       <marker id="PORT_EXT"/>
       <title>PORT_EXT</title>
 	<table align="left">
@@ -441,13 +602,46 @@
 	  </row>
 	<tcaption>PORT_EXT</tcaption></table>
 	<p>
-	  Encodes a port object (obtained from
-          <seealso marker="erlang:open_port/2">
-          <c>erlang:open_port/2</c></seealso>).
-	  The <c>ID</c> is a node-specific identifier for a local port.
+	  Same as <seealso marker="#NEW_PORT_EXT"><c>NEW_PORT_EXT</c></seealso>
+	  except the <c>Creation</c> field is only one byte and only two
+	  bits are significant, the rest are to be 0.
+	</p>
+    </section>
+
+    <section>
+      <marker id="NEW_PORT_EXT"/>
+      <title>NEW_PORT_EXT</title>
+	<table align="left">
+	  <row>
+	    <cell align="center">1</cell>
+	    <cell align="center">N</cell>
+	    <cell align="center">4</cell>
+	    <cell align="center">4</cell>
+	  </row>
+	  <row>
+	    <cell align="center"><c>89</c></cell>
+	    <cell align="center"><c>Node</c></cell>
+	    <cell align="center"><c>ID</c></cell>
+	    <cell align="center"><c>Creation</c></cell>
+	  </row>
+	<tcaption>NEW_PORT_EXT</tcaption></table>
+	<p>
+	  Encodes a port identifier (obtained from
+          <seealso marker="erlang#open_port/2"><c>erlang:open_port/2</c></seealso>).
+	  <c>Node</c> is an encoded atom, that is,
+	  <seealso marker="#ATOM_UTF8_EXT"><c>ATOM_UTF8_EXT</c></seealso>,
+	  <seealso marker="#SMALL_ATOM_UTF8_EXT"><c>SMALL_ATOM_UTF8_EXT</c></seealso>
+	  or <seealso marker="#ATOM_CACHE_REF"><c>ATOM_CACHE_REF</c></seealso>.
+	  <c>ID</c> is a 32-bit big endian unsigned integer. Only 28 bits are
+	  significant; the rest are to be 0. The <c>Creation</c> works just like in
+	  <seealso marker="#NEW_PID_EXT"><c>NEW_PID_EXT</c></seealso>.
 	  Port operations are not allowed across node boundaries.
-	  The <c>Creation</c> works just like in
-	  <seealso marker="#REFERENCE_EXT"><c>REFERENCE_EXT</c></seealso>.
+	</p>
+	<p>Introduced in OTP 19, but only to be decoded and echoed back. Not
+	  encoded for local ports. Planned to supersede <seealso marker="#PORT_EXT">
+	  <c>PORT_EXT</c></seealso> in OTP 23 when
+	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_BIG_CREATON</c></seealso>
+	  becomes mandatory.
 	</p>
     </section>
 
@@ -471,12 +665,65 @@
 	  </row>
 	<tcaption>PID_EXT</tcaption></table>
 	<p>
-	  Encodes a process identifier object (obtained from
-          <seealso marker="erlang:spawn/3"><c>erlang:spawn/3</c></seealso> or
-	  friends). The <c>ID</c> and <c>Creation</c> fields works just like in
-	  <seealso marker="#REFERENCE_EXT"><c>REFERENCE_EXT</c></seealso>, while
-	  the <c>Serial</c> field is used to improve safety.	  
-	  In <c>ID</c>, only 15 bits are significant; the rest are to be 0.
+	  Same as <seealso marker="#NEW_PID_EXT"><c>NEW_PID_EXT</c></seealso>
+	  except the <c>Creation</c> field is only one byte and only two
+	  bits are significant, the rest are to be 0.
+	</p>
+    </section>
+
+    <section>
+      <marker id="NEW_PID_EXT"/>
+      <title>NEW_PID_EXT</title>
+	<table align="left">
+	  <row>
+	    <cell align="center">1</cell>
+	    <cell align="center">N</cell>
+	    <cell align="center">4</cell>
+	    <cell align="center">4</cell>
+	    <cell align="center">4</cell>
+	  </row>
+	  <row>
+	    <cell align="center"><c>88</c></cell>
+	    <cell align="center"><c>Node</c></cell>
+	    <cell align="center"><c>ID</c></cell>
+	    <cell align="center"><c>Serial</c></cell>
+	    <cell align="center"><c>Creation</c></cell>
+	  </row>
+	<tcaption>NEW_PID_EXT</tcaption></table>
+	<p>
+	  Encodes an Erlang process identifier object.
+	</p>
+	<taglist>
+	  <tag><c>Node</c></tag>
+	  <item><p>The name of the originating node, encoded using
+	    <seealso marker="#ATOM_UTF8_EXT"><c>ATOM_UTF8_EXT</c></seealso>,
+	    <seealso marker="#SMALL_ATOM_UTF8_EXT"><c>SMALL_ATOM_UTF8_EXT</c></seealso>
+	    or <seealso
+	    marker="#ATOM_CACHE_REF"><c>ATOM_CACHE_REF</c></seealso>.</p>
+	  </item>
+	  <tag><c>ID</c></tag>
+	  <item><p>A 32-bit big endian unsigned integer. Only 15 bits are
+	    significant; the rest are to be 0.</p>
+	  </item>
+	  <tag><c>Serial</c></tag>
+	  <item><p>A 32-bit big endian unsigned integer. Only 13 bits are
+	    significant; the rest are to be 0.</p>
+	  </item>
+	  <tag><c>Creation</c></tag>
+	  <item><p>A 32-bit big endian unsigned integer. All identifiers
+	    originating from the same node incarnation must have identical <c>Creation</c>
+	    values. This makes it possible to separate identifiers from old
+	    (crashed) nodes from a new one. The value zero should be avoided for
+	    normal operations as it is used as a wild card for debug purpose
+	    (like a pid returned by <seealso marker="erts:erlang#list_to_pid/1">
+	    erlang:list_to_pid/1</seealso>).</p>
+	  </item>
+	</taglist>
+	<p>Introduced in OTP 19, but only to be decoded and echoed back. Not
+	  encoded for local processes. Planned to supersede <seealso marker="#PID_EXT">
+	  <c>PID_EXT</c></seealso> in OTP 23 when
+	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_BIG_CREATON</c></seealso>
+	  becomes mandatory.
 	</p>
     </section>
 
@@ -666,7 +913,7 @@
 	<tcaption>SMALL_BIG_EXT</tcaption></table>
 	<p>
 	  Bignums are stored in unary form with a <c>Sign</c> byte,
-	  that is, 0 if the binum is positive and 1 if it is negative. The
+	  that is, 0 if the bignum is positive and 1 if it is negative. The
 	  digits are stored with the least significant byte stored first. To
 	  calculate the integer, the following formula can be used:
 	</p>
@@ -700,6 +947,30 @@
     </section>
 
     <section>
+      <marker id="REFERENCE_EXT"/>
+      <title>REFERENCE_EXT (deprecated)</title>
+      <table align="left">
+        <row>
+          <cell align="center">1</cell>
+          <cell align="center">N</cell>
+          <cell align="center">4</cell>
+          <cell align="center">1</cell>
+        </row>
+        <row>
+          <cell align="center"><c>101</c></cell>
+          <cell align="center"><c>Node</c></cell>
+          <cell align="center"><c>ID</c></cell>
+          <cell align="center"><c>Creation</c></cell>
+        </row>
+      <tcaption>REFERENCE_EXT</tcaption></table>
+      <p>
+	The same as <seealso marker="#NEW_REFERENCE_EXT">
+	<c>NEW_REFERENCE_EXT</c></seealso> except <c>ID</c> is only one word
+	(<c>Len</c> = 1).
+      </p>
+    </section>
+
+    <section>
       <marker id="NEW_REFERENCE_EXT"/>
       <title>NEW_REFERENCE_EXT</title>
 	<table align="left">
@@ -719,29 +990,68 @@
 	  </row>
 	<tcaption>NEW_REFERENCE_EXT</tcaption></table>
 	<p>
-	  <c>Node</c> and <c>Creation</c> are as in
-	  <seealso marker="#REFERENCE_EXT"><c>REFERENCE_EXT</c></seealso>.
-	</p>
-	<p>
-	  <c>ID</c> contains a sequence of big-endian unsigned integers
-	  (4 bytes each, so <c>N'</c> is a multiple of 4),
-	  but is to be regarded as uninterpreted data.
-	</p>
-	<p>
-	  <c>N'</c> = 4 * <c>Len</c>.
-	</p>
-	<p>
-	  In the first word (4 bytes) of <c>ID</c>, only 18 bits are
-	  significant, the rest are to be 0.
-	  In <c>Creation</c>, only two bits are significant,
-	  the rest are to be 0.
+	  The same as <seealso marker="#NEWER_REFERENCE_EXT">
+	  <c>NEWER_REFERENCE_EXT</c></seealso> <em>except</em>:
 	</p>
+	<taglist>
+	  <tag><c>ID</c></tag>
+	  <item><p>In the first word (4 bytes) of <c>ID</c>, only 18 bits are
+	    significant, the rest must be 0.</p>
+	  </item>
+	  <tag><c>Creation</c></tag>
+	  <item><p>Only one byte long and only two bits are significant, the rest must be 0.</p>
+	  </item>
+	</taglist>
+    </section>
+
+    <section>
+      <marker id="NEWER_REFERENCE_EXT"/>
+      <title>NEWER_REFERENCE_EXT</title>
+	<table align="left">
+	  <row>
+	    <cell align="center">1</cell>
+	    <cell align="center">2</cell>
+	    <cell align="center">N</cell>
+	    <cell align="center">4</cell>
+	    <cell align="center">N'</cell>
+	  </row>
+	  <row>
+	    <cell align="center"><c>90</c></cell>
+	    <cell align="center"><c>Len</c></cell>
+	    <cell align="center"><c>Node</c></cell>
+	    <cell align="center"><c>Creation</c></cell>
+	    <cell align="center"><c>ID ...</c></cell>
+	  </row>
+	<tcaption>NEWER_REFERENCE_EXT</tcaption></table>
 	<p>
-	  <c>NEW_REFERENCE_EXT</c> was introduced with distribution version 4.
-	  In version 4, <c>N'</c> is to be at most 12.
+	  Encodes a reference term generated with
+	  <seealso marker="erts:erlang#make_ref/0">erlang:make_ref/0</seealso>.
 	</p>
-	<p>
-	  See <seealso marker="#REFERENCE_EXT"><c>REFERENCE_EXT</c></seealso>.
+	<taglist>
+	  <tag><c>Node</c></tag>
+	  <item><p>The name of the originating node, encoded using
+	    <seealso marker="#ATOM_UTF8_EXT"><c>ATOM_UTF8_EXT</c></seealso>,
+	    <seealso marker="#SMALL_ATOM_UTF8_EXT"><c>SMALL_ATOM_UTF8_EXT</c></seealso>
+	    or <seealso marker="#ATOM_CACHE_REF"><c>ATOM_CACHE_REF</c></seealso>.</p>
+	  </item>
+	  <tag><c>Len</c></tag>
+	  <item><p>A 16-bit big endian unsigned integer not larger than 3.</p>
+	  </item>
+	  <tag><c>ID</c></tag>
+	  <item><p>A sequence of <c>Len</c> big-endian unsigned integers
+	    (4 bytes each, so <c>N'</c>&nbsp;=&nbsp;4&nbsp;*&nbsp;<c>Len</c>),
+	    but is to be regarded as uninterpreted data.</p>
+	  </item>
+	  <tag><c>Creation</c></tag>
+	  <item><p>Works just like in
+	  <seealso marker="#NEW_PID_EXT"><c>NEW_PID_EXT</c></seealso>.</p>
+	  </item>
+	</taglist>
+	<p>Introduced in OTP 19, but only to be decoded and echoed back. Not
+	  encoded for local references. Planned to supersede <seealso marker="#NEW_REFERENCE_EXT">
+	  <c>NEW_REFERENCE_EXT</c></seealso> in OTP 23 when
+	  <seealso marker="erl_dist_protocol#dflags"><c>DFLAG_BIG_CREATON</c></seealso>
+	  becomes mandatory.
 	</p>
     </section>
 
@@ -989,7 +1299,8 @@
 	  </row>
 	<tcaption>NEW_FLOAT_EXT</tcaption></table>
 	<p>
-	  A float is stored as 8 bytes in big-endian IEEE format.
+	  A finite float (i.e. not inf, -inf or NaN) is stored as 8 bytes
+	  in big-endian IEEE format.
 	</p>
 	<p>
 	  This term is used in minor version 1 of the external format.
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml
index bbc12b0a56..d74ae23a93 100644
--- a/erts/doc/src/erl_nif.xml
+++ b/erts/doc/src/erl_nif.xml
@@ -546,8 +546,8 @@ int writeiovec(ErlNifEnv *env, ERL_NIF_TERM term, ERL_NIF_TERM *tail,
             <p>Many operations communicating with a process executing a
               dirty NIF can, however, complete while it executes the
               dirty NIF. For example, retrieving information about it through
-              <seealso marker="erlang:process_info/1">
-              <c>erlang:process_info</c></seealso>, setting its group leader,
+              <seealso marker="erlang#process_info/1">
+              <c>process_info</c></seealso>, setting its group leader,
               register/unregister its name, and so on.</p>
             <p>Termination of a process executing a dirty NIF can only be
               completed up to a certain point while it executes the dirty NIF.
@@ -783,14 +783,16 @@ typedef struct {
         <p>A process identifier (pid). In contrast to pid terms (instances of
           <c>ERL_NIF_TERM</c>), <c>ErlNifPid</c>s are self-contained and not
           bound to any <seealso marker="#ErlNifEnv">environment</seealso>.
-          <c>ErlNifPid</c> is an opaque type.</p>
+          <c>ErlNifPid</c> is an opaque type. It can be copied, moved
+	  in memory, forgotten, and so on.</p>
       </item>
       <tag><marker id="ErlNifPort"/><c>ErlNifPort</c></tag>
       <item>
         <p>A port identifier. In contrast to port ID terms (instances of
           <c>ERL_NIF_TERM</c>), <c>ErlNifPort</c>s are self-contained and not
           bound to any <seealso marker="#ErlNifEnv">environment</seealso>.
-          <c>ErlNifPort</c> is an opaque type.</p>
+	  <c>ErlNifPort</c> is an opaque type. It can be copied, moved
+	  in memory, forgotten, and so on.</p>
       </item>
       <tag><marker id="ErlNifResourceType"/><c>ErlNifResourceType</c></tag>
       <item>
@@ -963,7 +965,7 @@ typedef struct {
 
   <funcs>
     <func>
-      <name><ret>void *</ret><nametext>enif_alloc(size_t size)</nametext></name>
+      <name since=""><ret>void *</ret><nametext>enif_alloc(size_t size)</nametext></name>
       <fsummary>Allocate dynamic memory.</fsummary>
       <desc>
         <p>Allocates memory of <c>size</c> bytes.</p>
@@ -974,7 +976,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since=""><ret>int</ret>
         <nametext>enif_alloc_binary(size_t size, ErlNifBinary* bin)</nametext>
       </name>
       <fsummary>Create a new binary.</fsummary>
@@ -998,7 +1000,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>ErlNifEnv *</ret><nametext>enif_alloc_env()</nametext></name>
+      <name since="OTP R14B"><ret>ErlNifEnv *</ret><nametext>enif_alloc_env()</nametext></name>
       <fsummary>Create a new environment.</fsummary>
       <desc>
         <p>Allocates a new process independent environment. The environment can
@@ -1012,7 +1014,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>void *</ret><nametext>enif_alloc_resource(ErlNifResourceType*
+      <name since="OTP R13B04"><ret>void *</ret><nametext>enif_alloc_resource(ErlNifResourceType*
         type, unsigned size)</nametext></name>
       <fsummary>Allocate a memory-managed resource object.</fsummary>
       <desc>
@@ -1022,7 +1024,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>size_t</ret><nametext>enif_binary_to_term(ErlNifEnv *env,
+      <name since="OTP 19.0"><ret>size_t</ret><nametext>enif_binary_to_term(ErlNifEnv *env,
         const unsigned char* data, size_t size, ERL_NIF_TERM *term,
         ErlNifBinaryToTerm opts)</nametext></name>
       <fsummary>Create a term from the external format.</fsummary>
@@ -1047,7 +1049,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>enif_clear_env(ErlNifEnv* env)</nametext>
+      <name since="OTP R14B"><ret>void</ret><nametext>enif_clear_env(ErlNifEnv* env)</nametext>
       </name>
       <fsummary>Clear an environment for reuse.</fsummary>
       <desc>
@@ -1058,7 +1060,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_compare(ERL_NIF_TERM lhs, ERL_NIF_TERM rhs)</nametext>
       </name>
       <fsummary>Compare two terms.</fsummary>
@@ -1073,7 +1075,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_compare_monitors(const ErlNifMonitor
+      <name since="OTP 20.0"><ret>int</ret><nametext>enif_compare_monitors(const ErlNifMonitor
         *monitor1, const ErlNifMonitor *monitor2)</nametext></name>
       <fsummary>Compare two monitors.</fsummary>
       <desc>
@@ -1088,7 +1090,21 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP 22.0"><ret>int</ret>
+      <nametext>enif_compare_pids(const ErlNifPid *pid1, const ErlNifPid *pid2)
+      </nametext></name>
+      <fsummary>Compare two pids.</fsummary>
+      <desc>
+        <p>Compares two <seealso marker="#ErlNifPid"><c>ErlNifPid</c>
+	  </seealso>s according to term order.</p>
+        <p>Returns <c>0</c> if <c>pid1</c> and <c>pid2</c> are equal,
+          &lt; <c>0</c> if <c>pid1</c> &lt; <c>pid2</c>, and
+          &gt; <c>0</c> if <c>pid1</c> &gt; <c>pid2</c>.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_cond_broadcast(ErlNifCond *cnd)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -1098,7 +1114,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>ErlNifCond *</ret>
+      <name since="OTP R13B04"><ret>ErlNifCond *</ret>
         <nametext>enif_cond_create(char *name)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -1108,7 +1124,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_cond_destroy(ErlNifCond *cnd)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -1118,7 +1134,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>char*</ret>
+      <name since="OTP 21.0"><ret>char*</ret>
         <nametext>enif_cond_name(ErlNifCond* cnd)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -1128,7 +1144,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_cond_signal(ErlNifCond *cnd)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -1138,7 +1154,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_cond_wait(ErlNifCond *cnd, ErlNifMutex *mtx)</nametext>
       </name>
       <fsummary></fsummary>
@@ -1149,7 +1165,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R16B"><ret>int</ret>
         <nametext>enif_consume_timeslice(ErlNifEnv *env, int percent)</nametext>
       </name>
       <fsummary></fsummary>
@@ -1184,7 +1200,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>ErlNifTime</ret><nametext>enif_convert_time_unit(ErlNifTime
+      <name since="OTP 18.3"><ret>ErlNifTime</ret><nametext>enif_convert_time_unit(ErlNifTime
         val, ErlNifTimeUnit from, ErlNifTimeUnit to)</nametext></name>
       <fsummary>Convert time unit of a time value.</fsummary>
       <desc>
@@ -1209,7 +1225,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP 19.0"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_cpu_time(ErlNifEnv *)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -1225,8 +1241,8 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_demonitor_process(ErlNifEnv* caller_env, void* obj,
-      const ErlNifMonitor* mon)</nametext></name>
+      <name since="OTP 20.0"><ret>int</ret><nametext>enif_demonitor_process(ErlNifEnv* caller_env,
+      void* obj, const ErlNifMonitor* mon)</nametext></name>
       <fsummary>Cancel a process monitor.</fsummary>
       <desc>
         <marker id="enif_demonitor_process"></marker>
@@ -1252,7 +1268,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_equal_tids(ErlNifTid tid1, ErlNifTid tid2)</nametext>
       </name>
       <fsummary></fsummary>
@@ -1263,7 +1279,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_fprintf(FILE *stream, const char *format, ...)</nametext></name>
+      <name since="OTP 21.0"><ret>int</ret><nametext>enif_fprintf(FILE *stream, const char *format, ...)</nametext></name>
       <fsummary>Format strings and Erlang terms.</fsummary>
       <desc>
         <p>Similar to <c>fprintf</c> but this format string also accepts
@@ -1276,7 +1292,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>enif_free(void* ptr)</nametext></name>
+      <name since=""><ret>void</ret><nametext>enif_free(void* ptr)</nametext></name>
       <fsummary>Free dynamic memory.</fsummary>
       <desc>
         <p>Frees memory allocated by
@@ -1285,7 +1301,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R14B"><ret>void</ret>
         <nametext>enif_free_env(ErlNifEnv* env)</nametext></name>
       <fsummary>Free an environment allocated with enif_alloc_env.</fsummary>
       <desc>
@@ -1296,7 +1312,7 @@ typedef struct {
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP 20.1"><ret>void</ret>
         <nametext>enif_free_iovec(ErlNifIOvec* iov)</nametext></name>
       <fsummary>Free an ErlIOVec</fsummary>
       <desc>
@@ -1321,7 +1337,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_atom(ErlNifEnv* env, ERL_NIF_TERM
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_get_atom(ErlNifEnv* env, ERL_NIF_TERM
         term, char* buf, unsigned size, ErlNifCharEncoding encode)</nametext>
       </name>
       <fsummary>Get the text representation of an atom term.</fsummary>
@@ -1337,7 +1353,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_atom_length(ErlNifEnv* env,
+      <name since="OTP R14B"><ret>int</ret><nametext>enif_get_atom_length(ErlNifEnv* env,
         ERL_NIF_TERM term, unsigned* len, ErlNifCharEncoding encode)</nametext>
       </name>
       <fsummary>Get the length of atom <c>term</c>.</fsummary>
@@ -1351,7 +1367,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_double(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_get_double(ErlNifEnv* env,
         ERL_NIF_TERM term, double* dp)</nametext></name>
       <fsummary>Read a floating-point number term.</fsummary>
       <desc>
@@ -1362,7 +1378,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_int(ErlNifEnv* env, ERL_NIF_TERM
+      <name since=""><ret>int</ret><nametext>enif_get_int(ErlNifEnv* env, ERL_NIF_TERM
         term, int* ip)</nametext></name>
       <fsummary>Read an integer term.</fsummary>
       <desc>
@@ -1373,7 +1389,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_int64(ErlNifEnv* env, ERL_NIF_TERM
+      <name since="OTP R14B"><ret>int</ret><nametext>enif_get_int64(ErlNifEnv* env, ERL_NIF_TERM
         term, ErlNifSInt64* ip)</nametext></name>
       <fsummary>Read a 64-bit integer term.</fsummary>
       <desc>
@@ -1384,7 +1400,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_local_pid(ErlNifEnv* env,
+      <name since="OTP R14B"><ret>int</ret><nametext>enif_get_local_pid(ErlNifEnv* env,
         ERL_NIF_TERM term, ErlNifPid* pid)</nametext></name>
       <fsummary>Read a local pid term.</fsummary>
       <desc>
@@ -1392,11 +1408,14 @@ enif_free_iovec(iovec);]]></code>
           initializes the pid variable <c>*pid</c> from it and returns
           <c>true</c>. Otherwise returns <c>false</c>. No check is done to see
           if the process is alive.</p>
+	<note><p><c>enif_get_local_pid</c> will return false if argument
+	<c>term</c> is the atom <seealso marker="#enif_make_pid">
+	<c>undefined</c></seealso>.</p></note>
       </desc>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_local_port(ErlNifEnv* env,
+      <name since="OTP 19.0"><ret>int</ret><nametext>enif_get_local_port(ErlNifEnv* env,
         ERL_NIF_TERM term, ErlNifPort* port_id)</nametext></name>
       <fsummary>Read a local port term.</fsummary>
       <desc>
@@ -1408,7 +1427,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_list_cell(ErlNifEnv* env,
+      <name since=""><ret>int</ret><nametext>enif_get_list_cell(ErlNifEnv* env,
         ERL_NIF_TERM list, ERL_NIF_TERM* head, ERL_NIF_TERM* tail)</nametext>
       </name>
       <fsummary>Get head and tail from a list.</fsummary>
@@ -1420,7 +1439,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_list_length(ErlNifEnv* env,
+      <name since="OTP R14B"><ret>int</ret><nametext>enif_get_list_length(ErlNifEnv* env,
         ERL_NIF_TERM term, unsigned* len)</nametext></name>
       <fsummary>Get the length of list <c>term</c>.</fsummary>
       <desc>
@@ -1431,7 +1450,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_long(ErlNifEnv* env, ERL_NIF_TERM
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_get_long(ErlNifEnv* env, ERL_NIF_TERM
         term, long int* ip)</nametext></name>
       <fsummary>Read a long integer term.</fsummary>
       <desc>
@@ -1442,7 +1461,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_map_size(ErlNifEnv* env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_get_map_size(ErlNifEnv* env,
         ERL_NIF_TERM term, size_t *size)</nametext></name>
       <fsummary>Read the size of a map term.</fsummary>
       <desc>
@@ -1454,7 +1473,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_map_value(ErlNifEnv* env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_get_map_value(ErlNifEnv* env,
         ERL_NIF_TERM map, ERL_NIF_TERM key, ERL_NIF_TERM* value)</nametext>
       </name>
       <fsummary>Get the value of a key in a map.</fsummary>
@@ -1467,7 +1486,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_resource(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_get_resource(ErlNifEnv* env,
         ERL_NIF_TERM term, ErlNifResourceType* type, void** objp)</nametext>
       </name>
       <fsummary>Get the pointer to a resource object.</fsummary>
@@ -1476,11 +1495,14 @@ enif_free_iovec(iovec);]]></code>
           <c>term</c>.</p>
         <p>Returns <c>true</c> on success, or <c>false</c> if <c>term</c> is
           not a handle to a resource object of type <c>type</c>.</p>
+	<p><c>enif_get_resource</c> does not add a reference to the resource
+	  object. However, the pointer received in <c>*objp</c> is guaranteed to
+	  be valid at least as long as the resource handle <c>term</c> is valid.</p>
       </desc>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_string(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_get_string(ErlNifEnv* env,
         ERL_NIF_TERM list, char* buf, unsigned size,
         ErlNifCharEncoding encode)</nametext></name>
       <fsummary>Get a C-string from a list.</fsummary>
@@ -1504,7 +1526,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_tuple(ErlNifEnv* env, ERL_NIF_TERM
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_get_tuple(ErlNifEnv* env, ERL_NIF_TERM
         term, int* arity, const ERL_NIF_TERM** array)</nametext></name>
       <fsummary>Inspect the elements of a tuple.</fsummary>
       <desc>
@@ -1520,7 +1542,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_uint(ErlNifEnv* env, ERL_NIF_TERM
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_get_uint(ErlNifEnv* env, ERL_NIF_TERM
         term, unsigned int* ip)</nametext></name>
       <fsummary>Read an unsigned integer term.</fsummary>
       <desc>
@@ -1532,7 +1554,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_uint64(ErlNifEnv* env,
+      <name since="OTP R14B"><ret>int</ret><nametext>enif_get_uint64(ErlNifEnv* env,
         ERL_NIF_TERM term, ErlNifUInt64* ip)</nametext></name>
       <fsummary>Read an unsigned 64-bit integer term.</fsummary>
       <desc>
@@ -1544,7 +1566,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_get_ulong(ErlNifEnv* env, ERL_NIF_TERM
+      <name since=""><ret>int</ret><nametext>enif_get_ulong(ErlNifEnv* env, ERL_NIF_TERM
         term, unsigned long* ip)</nametext></name>
       <fsummary>Read an unsigned integer term.</fsummary>
       <desc>
@@ -1557,7 +1579,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_getenv(const char* key, char* value,
+      <name since="OTP 18.2"><ret>int</ret><nametext>enif_getenv(const char* key, char* value,
         size_t *value_size)</nametext></name>
       <fsummary>Get the value of an environment variable.</fsummary>
       <desc>
@@ -1567,7 +1589,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_has_pending_exception(ErlNifEnv* env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_has_pending_exception(ErlNifEnv* env,
         ERL_NIF_TERM* reason)</nametext></name>
       <fsummary>Check if an exception has been raised.</fsummary>
       <desc>
@@ -1588,7 +1610,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name>
+      <name since="OTP 20.0">
         <ret>ErlNifUInt64</ret>
         <nametext>enif_hash(ErlNifHash type, ERL_NIF_TERM term, ErlNifUInt64 salt)</nametext>
       </name>
@@ -1601,7 +1623,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_inspect_binary(ErlNifEnv* env,
+      <name since=""><ret>int</ret><nametext>enif_inspect_binary(ErlNifEnv* env,
         ERL_NIF_TERM bin_term, ErlNifBinary* bin)</nametext></name>
       <fsummary>Inspect the content of a binary.</fsummary>
       <desc>
@@ -1613,7 +1635,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_inspect_iolist_as_binary(ErlNifEnv*
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_inspect_iolist_as_binary(ErlNifEnv*
         env, ERL_NIF_TERM term, ErlNifBinary* bin)</nametext></name>
       <fsummary>Inspect the content of an iolist.</fsummary>
       <desc>
@@ -1627,7 +1649,7 @@ enif_free_iovec(iovec);]]></code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_inspect_iovec(ErlNifEnv*
+      <name since="OTP 20.1"><ret>int</ret><nametext>enif_inspect_iovec(ErlNifEnv*
         env, size_t max_elements, ERL_NIF_TERM iovec_term, ERL_NIF_TERM* tail,
         ErlNifIOVec** iovec)</nametext></name>
       <fsummary>Inspect a list of binaries as an ErlNifIOVec.</fsummary>
@@ -1667,7 +1689,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ErlNifIOQueue *</ret>
+      <name since="OTP 20.1"><ret>ErlNifIOQueue *</ret>
       <nametext>enif_ioq_create(ErlNifIOQueueOpts opts)</nametext></name>
       <fsummary>Create a new IO Queue</fsummary>
       <desc>
@@ -1678,7 +1700,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP 20.1"><ret>void</ret>
       <nametext>enif_ioq_destroy(ErlNifIOQueue *q)</nametext></name>
       <fsummary>Destroy an IO Queue and free it's content</fsummary>
       <desc>
@@ -1687,7 +1709,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 20.1"><ret>int</ret>
       <nametext>enif_ioq_deq(ErlNifIOQueue *q, size_t count, size_t *size)</nametext></name>
       <fsummary>Dequeue count bytes from the IO Queue</fsummary>
       <desc>
@@ -1700,7 +1722,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 20.1"><ret>int</ret>
       <nametext>enif_ioq_enq_binary(ErlNifIOQueue *q, ErlNifBinary *bin, size_t skip)</nametext></name>
       <fsummary>Enqueue the binary into the IO Queue</fsummary>
       <desc>
@@ -1713,7 +1735,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 20.1"><ret>int</ret>
       <nametext>enif_ioq_enqv(ErlNifIOQueue *q, ErlNifIOVec *iovec, size_t skip)</nametext></name>
       <fsummary>Enqueue the iovec into the IO Queue</fsummary>
       <desc>
@@ -1724,7 +1746,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>SysIOVec *</ret>
+      <name since="OTP 20.1"><ret>SysIOVec *</ret>
       <nametext>enif_ioq_peek(ErlNifIOQueue *q, int *iovlen)</nametext></name>
       <fsummary>Peek inside the IO Queue</fsummary>
       <desc>
@@ -1738,7 +1760,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 21.0"><ret>int</ret>
       <nametext>enif_ioq_peek_head(ErlNifEnv *env, ErlNifIOQueue *q, size_t *size, ERL_NIF_TERM *bin_term)</nametext></name>
       <fsummary>Peek the head of the IO Queue.</fsummary>
       <desc>
@@ -1753,7 +1775,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>size_t</ret>
+      <name since="OTP 20.1"><ret>size_t</ret>
       <nametext>enif_ioq_size(ErlNifIOQueue *q)</nametext></name>
       <fsummary>Get the current size of the IO Queue</fsummary>
       <desc>
@@ -1762,7 +1784,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_is_atom(ErlNifEnv* env, ERL_NIF_TERM term)</nametext>
       </name>
       <fsummary>Determine if a term is an atom.</fsummary>
@@ -1772,7 +1794,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since=""><ret>int</ret>
         <nametext>enif_is_binary(ErlNifEnv* env, ERL_NIF_TERM term)</nametext>
       </name>
       <fsummary>Determine if a term is a binary.</fsummary>
@@ -1782,7 +1804,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 19.0"><ret>int</ret>
         <nametext>enif_is_current_process_alive(ErlNifEnv* env)</nametext>
       </name>
       <fsummary>Determine if currently executing process is alive.</fsummary>
@@ -1795,7 +1817,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_is_empty_list(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_is_empty_list(ErlNifEnv* env,
         ERL_NIF_TERM term)</nametext></name>
       <fsummary>Determine if a term is an empty list.</fsummary>
       <desc>
@@ -1804,7 +1826,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_is_exception(ErlNifEnv* env,
+      <name since="OTP R14B03"><ret>int</ret><nametext>enif_is_exception(ErlNifEnv* env,
         ERL_NIF_TERM term)</nametext></name>
       <fsummary>Determine if a term is an exception.</fsummary>
       <desc><marker id="enif_is_exception"/>
@@ -1813,7 +1835,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_is_fun(ErlNifEnv* env, ERL_NIF_TERM
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_is_fun(ErlNifEnv* env, ERL_NIF_TERM
         term)</nametext></name>
       <fsummary>Determine if a term is a fun.</fsummary>
       <desc>
@@ -1822,7 +1844,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_is_identical(ERL_NIF_TERM lhs,
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_is_identical(ERL_NIF_TERM lhs,
         ERL_NIF_TERM rhs)</nametext></name>
       <fsummary>Erlang operator =:=.</fsummary>
       <desc>
@@ -1832,7 +1854,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R14B"><ret>int</ret>
         <nametext>enif_is_list(ErlNifEnv* env, ERL_NIF_TERM term)</nametext>
       </name>
       <fsummary>Determine if a term is a list.</fsummary>
@@ -1842,7 +1864,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_is_map(ErlNifEnv* env, ERL_NIF_TERM
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_is_map(ErlNifEnv* env, ERL_NIF_TERM
         term)</nametext></name>
       <fsummary>Determine if a term is a map.</fsummary>
       <desc>
@@ -1852,7 +1874,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_is_number(ErlNifEnv* env, ERL_NIF_TERM
+      <name since="OTP R15B"><ret>int</ret><nametext>enif_is_number(ErlNifEnv* env, ERL_NIF_TERM
         term)</nametext></name>
       <fsummary>Determine if a term is a number (integer or float).</fsummary>
       <desc>
@@ -1861,7 +1883,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_is_pid(ErlNifEnv* env, ERL_NIF_TERM term)</nametext>
       </name>
       <fsummary>Determine if a term is a pid.</fsummary>
@@ -1871,7 +1893,18 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 22.0"><ret>int</ret>
+        <nametext>enif_is_pid_undefined(const ErlNifPid* pid)</nametext></name>
+      <fsummary>Determine if pid is undefined.</fsummary>
+      <desc>
+        <p>Returns <c>true</c> if <c>pid</c> has been set as undefined by
+	<seealso marker="#enif_set_pid_undefined"><c>enif_set_pid_undefined</c>
+	</seealso>.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_is_port(ErlNifEnv* env, ERL_NIF_TERM term)</nametext>
       </name>
       <fsummary>Determine if a term is a port.</fsummary>
@@ -1881,7 +1914,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_is_port_alive(ErlNifEnv* env,
+      <name since="OTP 19.0"><ret>int</ret><nametext>enif_is_port_alive(ErlNifEnv* env,
         ErlNifPort *port_id)</nametext></name>
       <fsummary>Determine if a local port is alive.</fsummary>
       <desc>
@@ -1893,7 +1926,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_is_process_alive(ErlNifEnv* env,
+      <name since="OTP 19.0"><ret>int</ret><nametext>enif_is_process_alive(ErlNifEnv* env,
         ErlNifPid *pid)</nametext></name>
       <fsummary>Determine if a local process is alive.</fsummary>
       <desc>
@@ -1905,7 +1938,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_is_ref(ErlNifEnv* env, ERL_NIF_TERM term)</nametext>
       </name>
       <fsummary>Determine if a term is a reference.</fsummary>
@@ -1915,7 +1948,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R14B"><ret>int</ret>
         <nametext>enif_is_tuple(ErlNifEnv* env, ERL_NIF_TERM term)</nametext>
       </name>
       <fsummary>Determine if a term is a tuple.</fsummary>
@@ -1925,7 +1958,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R14B"><ret>int</ret>
         <nametext>enif_keep_resource(void* obj)</nametext>
       </name>
       <fsummary>Add a reference to a resource object.</fsummary>
@@ -1941,7 +1974,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since=""><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_atom(ErlNifEnv* env, const char* name)</nametext>
       </name>
       <fsummary>Create an atom term.</fsummary>
@@ -1955,7 +1988,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_atom_len(ErlNifEnv* env,
+      <name since="OTP R14B"><ret>ERL_NIF_TERM</ret><nametext>enif_make_atom_len(ErlNifEnv* env,
         const char* name, size_t len)</nametext></name>
       <fsummary>Create an atom term.</fsummary>
       <desc>
@@ -1969,7 +2002,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since=""><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_badarg(ErlNifEnv* env)</nametext></name>
       <fsummary>Make a badarg exception.</fsummary>
       <desc>
@@ -1997,7 +2030,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since=""><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_binary(ErlNifEnv* env, ErlNifBinary* bin)</nametext>
       </name>
       <fsummary>Make a binary term.</fsummary>
@@ -2010,7 +2043,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_copy(ErlNifEnv* dst_env,
+      <name since="OTP R14B"><ret>ERL_NIF_TERM</ret><nametext>enif_make_copy(ErlNifEnv* dst_env,
         ERL_NIF_TERM src_term)</nametext></name>
       <fsummary>Make a copy of a term.</fsummary>
       <desc>
@@ -2021,7 +2054,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_double(ErlNifEnv* env, double d)</nametext></name>
       <fsummary>Create a floating-point term.</fsummary>
       <desc>
@@ -2033,7 +2066,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_make_existing_atom(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>int</ret><nametext>enif_make_existing_atom(ErlNifEnv* env,
         const char* name, ERL_NIF_TERM* atom, ErlNifCharEncoding
         encode)</nametext></name>
       <fsummary>Create an existing atom term.</fsummary>
@@ -2049,7 +2082,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_make_existing_atom_len(ErlNifEnv* env,
+      <name since="OTP R14B"><ret>int</ret><nametext>enif_make_existing_atom_len(ErlNifEnv* env,
         const char* name, size_t len, ERL_NIF_TERM* atom, ErlNifCharEncoding
         encoding)</nametext></name>
       <fsummary>Create an existing atom term.</fsummary>
@@ -2065,7 +2098,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
       </desc>
     </func>
 
-    <func><name><ret>ERL_NIF_TERM</ret>
+    <func><name since=""><ret>ERL_NIF_TERM</ret>
       <nametext>enif_make_int(ErlNifEnv* env, int i)</nametext></name>
       <fsummary>Create an integer term.</fsummary>
       <desc>
@@ -2074,7 +2107,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R14B"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_int64(ErlNifEnv* env, ErlNifSInt64 i)</nametext>
       </name>
       <fsummary>Create an integer term.</fsummary>
@@ -2084,7 +2117,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since=""><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_list(ErlNifEnv* env, unsigned cnt, ...)</nametext>
       </name>
       <fsummary>Create a list term.</fsummary>
@@ -2097,24 +2130,24 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_list1(ErlNifEnv* env, ERL_NIF_TERM e1)</nametext>
       </name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list2(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_list2(ErlNifEnv* env,
         ERL_NIF_TERM e1, ERL_NIF_TERM e2)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list3(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_list3(ErlNifEnv* env,
         ERL_NIF_TERM e1, ERL_NIF_TERM e2, ERL_NIF_TERM e3)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list4(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_list4(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e4)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list5(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_list5(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e5)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list6(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_list6(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e6)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list7(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_list7(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e7)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list8(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_list8(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e8)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list9(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_list9(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e9)</nametext></name>
       <fsummary>Create a list term.</fsummary>
       <desc>
@@ -2126,7 +2159,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list_cell(ErlNifEnv*
+      <name since=""><ret>ERL_NIF_TERM</ret><nametext>enif_make_list_cell(ErlNifEnv*
         env, ERL_NIF_TERM head, ERL_NIF_TERM tail)</nametext></name>
       <fsummary>Create a list cell.</fsummary>
       <desc>
@@ -2135,7 +2168,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_list_from_array(ErlNifEnv* env, const ERL_NIF_TERM
           arr[], unsigned cnt)</nametext></name>
       <fsummary>Create a list term from an array.</fsummary>
@@ -2147,7 +2180,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_long(ErlNifEnv* env, long int i)</nametext></name>
       <fsummary>Create an integer term from a long int.</fsummary>
       <desc>
@@ -2156,7 +2189,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_make_map_put(ErlNifEnv* env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_make_map_put(ErlNifEnv* env,
         ERL_NIF_TERM map_in, ERL_NIF_TERM key, ERL_NIF_TERM value,
         ERL_NIF_TERM* map_out)</nametext></name>
       <fsummary>Insert key-value pair in map.</fsummary>
@@ -2172,7 +2205,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_make_map_remove(ErlNifEnv* env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_make_map_remove(ErlNifEnv* env,
         ERL_NIF_TERM map_in, ERL_NIF_TERM key, ERL_NIF_TERM* map_out)</nametext>
       </name>
       <fsummary>Remove key from map.</fsummary>
@@ -2188,7 +2221,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_make_map_update(ErlNifEnv* env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_make_map_update(ErlNifEnv* env,
         ERL_NIF_TERM map_in, ERL_NIF_TERM key, ERL_NIF_TERM new_value,
         ERL_NIF_TERM* map_out)</nametext></name>
       <fsummary>Replace value for key in map.</fsummary>
@@ -2203,7 +2236,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 21.0"><ret>int</ret>
         <nametext>enif_make_map_from_arrays(ErlNifEnv* env, ERL_NIF_TERM keys[],
         ERL_NIF_TERM values[], size_t cnt, ERL_NIF_TERM *map_out)</nametext></name>
       <fsummary>Make map term from the given keys and values.</fsummary>
@@ -2217,7 +2250,19 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>unsigned char *</ret><nametext>enif_make_new_binary(ErlNifEnv*
+      <name since="OTP 22.0"><ret>ERL_NIF_TERM</ret>
+        <nametext>enif_make_monitor_term(ErlNifEnv* env, const ErlNifMonitor* mon)</nametext></name>
+      <fsummary>Make monitor term from the given monitor identifier.</fsummary>
+      <desc>
+        <p>Creates a term identifying the given monitor received from
+	<seealso marker="#enif_monitor_process"><c>enif_monitor_process</c>
+	</seealso>.</p>
+	<p>This function is primarily intended for debugging purpose.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name since="OTP R14B"><ret>unsigned char *</ret><nametext>enif_make_new_binary(ErlNifEnv*
         env, size_t size, ERL_NIF_TERM* termp)</nametext></name>
       <fsummary>Allocate and create a new binary term.</fsummary>
       <desc>
@@ -2233,7 +2278,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP 18.0"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_new_map(ErlNifEnv* env)</nametext></name>
       <fsummary>Make an empty map term.</fsummary>
       <desc>
@@ -2242,17 +2287,18 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R14B"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_pid(ErlNifEnv* env, const ErlNifPid* pid)</nametext>
       </name>
       <fsummary>Make a pid term.</fsummary>
       <desc>
-        <p>Makes a pid term from <c>*pid</c>.</p>
+        <p>Makes a pid term or the atom <seealso marker="#enif_set_pid_undefined">
+	<c>undefined</c></seealso> from <c>*pid</c>.</p>
       </desc>
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_ref(ErlNifEnv* env)</nametext></name>
       <fsummary>Create a reference.</fsummary>
       <desc>
@@ -2262,7 +2308,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_resource(ErlNifEnv* env, void* obj)</nametext>
       </name>
       <fsummary>Create an opaque handle to a resource object.</fsummary>
@@ -2310,7 +2356,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R14B"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_resource_binary(ErlNifEnv* env, void* obj, const
         void* data, size_t size)</nametext></name>
       <fsummary>Create a custom binary term.</fsummary>
@@ -2336,7 +2382,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R15B"><ret>int</ret>
         <nametext>enif_make_reverse_list(ErlNifEnv* env, ERL_NIF_TERM list_in,
         ERL_NIF_TERM *list_out)</nametext></name>
       <fsummary>Create the reverse of a list.</fsummary>
@@ -2352,7 +2398,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_string(ErlNifEnv* env,
+      <name since=""><ret>ERL_NIF_TERM</ret><nametext>enif_make_string(ErlNifEnv* env,
         const char* string, ErlNifCharEncoding encoding)</nametext></name>
       <fsummary>Create a string.</fsummary>
       <desc>
@@ -2363,7 +2409,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_string_len(ErlNifEnv*
+      <name since="OTP R14B"><ret>ERL_NIF_TERM</ret><nametext>enif_make_string_len(ErlNifEnv*
         env, const char* string, size_t len, ErlNifCharEncoding
         encoding)</nametext></name>
       <fsummary>Create a string.</fsummary>
@@ -2376,7 +2422,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_sub_binary(ErlNifEnv*
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_sub_binary(ErlNifEnv*
         env, ERL_NIF_TERM bin_term, size_t pos, size_t size)</nametext></name>
       <fsummary>Make a subbinary term.</fsummary>
       <desc>
@@ -2388,7 +2434,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple(ErlNifEnv* env,
+      <name since=""><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple(ErlNifEnv* env,
         unsigned cnt, ...)</nametext></name>
       <fsummary>Creates a tuple term.</fsummary>
       <desc>
@@ -2399,23 +2445,23 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple1(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple1(ErlNifEnv* env,
         ERL_NIF_TERM e1)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple2(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple2(ErlNifEnv* env,
         ERL_NIF_TERM e1, ERL_NIF_TERM e2)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple3(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple3(ErlNifEnv* env,
         ERL_NIF_TERM e1, ERL_NIF_TERM e2, ERL_NIF_TERM e3)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple4(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple4(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e4)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple5(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple5(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e5)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple6(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple6(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e6)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple7(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple7(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e7)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple8(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple8(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e8)</nametext></name>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple9(ErlNifEnv* env,
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple9(ErlNifEnv* env,
         ERL_NIF_TERM e1, ..., ERL_NIF_TERM e9)</nametext></name>
       <fsummary>Create a tuple term.</fsummary>
       <desc>
@@ -2427,7 +2473,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_tuple_from_array(ErlNifEnv* env, const ERL_NIF_TERM
         arr[], unsigned cnt)</nametext></name>
       <fsummary>Create a tuple term from an array.</fsummary>
@@ -2438,7 +2484,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R13B04"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_uint(ErlNifEnv* env, unsigned int i)</nametext>
       </name>
       <fsummary>Create an unsigned integer term.</fsummary>
@@ -2448,7 +2494,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP R14B"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_uint64(ErlNifEnv* env, ErlNifUInt64 i)</nametext>
       </name>
       <fsummary>Create an unsigned integer term.</fsummary>
@@ -2458,7 +2504,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since=""><ret>ERL_NIF_TERM</ret>
         <nametext>enif_make_ulong(ErlNifEnv* env, unsigned long i)</nametext>
       </name>
       <fsummary>Create an integer term from an unsigned long int.</fsummary>
@@ -2468,7 +2514,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_unique_integer(ErlNifEnv
+      <name since="OTP 19.0"><ret>ERL_NIF_TERM</ret><nametext>enif_make_unique_integer(ErlNifEnv
         *env, ErlNifUniqueInteger properties)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2486,7 +2532,7 @@ enif_inspect_iovec(env, max_elements, term, &amp;tail, &amp;iovec);
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_map_iterator_create(ErlNifEnv *env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_map_iterator_create(ErlNifEnv *env,
         ERL_NIF_TERM map, ErlNifMapIterator *iter, ErlNifMapIteratorEntry
         entry)</nametext></name>
       <fsummary>Create a map iterator.</fsummary>
@@ -2521,7 +2567,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>enif_map_iterator_destroy(ErlNifEnv *env,
+      <name since="OTP 18.0"><ret>void</ret><nametext>enif_map_iterator_destroy(ErlNifEnv *env,
         ErlNifMapIterator *iter)</nametext></name>
       <fsummary>Destroy a map iterator.</fsummary>
       <desc>
@@ -2532,7 +2578,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_map_iterator_get_pair(ErlNifEnv *env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_map_iterator_get_pair(ErlNifEnv *env,
         ErlNifMapIterator *iter, ERL_NIF_TERM *key, ERL_NIF_TERM
         *value)</nametext></name>
       <fsummary>Get key and value at current map iterator position.</fsummary>
@@ -2545,7 +2591,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_map_iterator_is_head(ErlNifEnv *env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_map_iterator_is_head(ErlNifEnv *env,
         ErlNifMapIterator *iter)</nametext></name>
       <fsummary>Check if map iterator is positioned before first.</fsummary>
       <desc>
@@ -2555,7 +2601,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_map_iterator_is_tail(ErlNifEnv *env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_map_iterator_is_tail(ErlNifEnv *env,
         ErlNifMapIterator *iter)</nametext></name>
       <fsummary>Check if map iterator is positioned after last.</fsummary>
       <desc>
@@ -2565,7 +2611,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_map_iterator_next(ErlNifEnv *env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_map_iterator_next(ErlNifEnv *env,
         ErlNifMapIterator *iter)</nametext></name>
       <fsummary>Increment map iterator to point to next entry.</fsummary>
       <desc>
@@ -2577,7 +2623,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_map_iterator_prev(ErlNifEnv *env,
+      <name since="OTP 18.0"><ret>int</ret><nametext>enif_map_iterator_prev(ErlNifEnv *env,
         ErlNifMapIterator *iter)</nametext></name>
       <fsummary>Decrement map iterator to point to previous entry.</fsummary>
       <desc>
@@ -2589,8 +2635,8 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_monitor_process(ErlNifEnv* caller_env, void* obj,
-      const ErlNifPid* target_pid, ErlNifMonitor* mon)</nametext></name>
+      <name since="OTP 20.0"><ret>int</ret><nametext>enif_monitor_process(ErlNifEnv* caller_env,
+      void* obj, const ErlNifPid* target_pid, ErlNifMonitor* mon)</nametext></name>
       <fsummary>Monitor a process from a resource.</fsummary>
       <desc>
         <marker id="enif_monitor_process"></marker>
@@ -2613,7 +2659,9 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
 	<p>Argument <c>caller_env</c> is the environment of the calling process
 	or callback. Must only be NULL if calling from a custom thread.</p>
         <p>Returns <c>0</c> on success, &lt; 0 if no <c>down</c> callback is
-          provided, and &gt; 0 if the process is no longer alive.</p>
+          provided, and &gt; 0 if the process is no longer alive or if
+	  <c>target_pid</c> is <seealso marker="#enif_set_pid_undefined">
+	  undefined</seealso>.</p>
         <p>This function is only thread-safe when the emulator with SMP support
           is used. It can only be used in a non-SMP emulator from a NIF-calling
           thread.</p>
@@ -2621,7 +2669,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>ErlNifTime</ret>
+      <name since="OTP 18.3"><ret>ErlNifTime</ret>
         <nametext>enif_monotonic_time(ErlNifTimeUnit time_unit)</nametext>
       </name>
       <fsummary>Get Erlang monotonic time.</fsummary>
@@ -2642,7 +2690,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>ErlNifMutex *</ret>
+      <name since="OTP R13B04"><ret>ErlNifMutex *</ret>
         <nametext>enif_mutex_create(char *name)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2652,7 +2700,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_mutex_destroy(ErlNifMutex *mtx)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2662,7 +2710,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_mutex_lock(ErlNifMutex *mtx)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2672,7 +2720,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>char*</ret>
+      <name since="OTP 21.0"><ret>char*</ret>
         <nametext>enif_mutex_name(ErlNifMutex* mtx)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2682,7 +2730,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
       <nametext>enif_mutex_trylock(ErlNifMutex *mtx)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2692,7 +2740,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_mutex_unlock(ErlNifMutex *mtx)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2702,7 +2750,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret>
+      <name since="OTP 19.0"><ret>ERL_NIF_TERM</ret>
         <nametext>enif_now_time(ErlNifEnv *env)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2713,7 +2761,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>ErlNifResourceType *</ret>
+      <name since="OTP R13B04"><ret>ErlNifResourceType *</ret>
         <nametext>enif_open_resource_type(ErlNifEnv* env, const char*
         module_str, const char* name, ErlNifResourceDtor* dtor,
         ErlNifResourceFlags flags, ErlNifResourceFlags* tried)</nametext>
@@ -2752,7 +2800,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>ErlNifResourceType *</ret>
+      <name since="OTP 20.0"><ret>ErlNifResourceType *</ret>
         <nametext>enif_open_resource_type_x(ErlNifEnv* env, const char* name,
 	const ErlNifResourceTypeInit* init,
         ErlNifResourceFlags flags, ErlNifResourceFlags* tried)</nametext>
@@ -2771,7 +2819,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-     <name><ret>int</ret><nametext>enif_port_command(ErlNifEnv* env, const
+     <name since="OTP 19.0"><ret>int</ret><nametext>enif_port_command(ErlNifEnv* env, const
        ErlNifPort* to_port, ErlNifEnv *msg_env, ERL_NIF_TERM msg)</nametext>
      </name>
      <fsummary>Send a port_command to to_port.</fsummary>
@@ -2814,7 +2862,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void *</ret>
+      <name since="OTP R13B04"><ret>void *</ret>
         <nametext>enif_priv_data(ErlNifEnv* env)</nametext></name>
       <fsummary>Get the private data of a NIF library.</fsummary>
       <desc>
@@ -2825,7 +2873,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_raise_exception(ErlNifEnv*
+      <name since="OTP 18.0"><ret>ERL_NIF_TERM</ret><nametext>enif_raise_exception(ErlNifEnv*
         env, ERL_NIF_TERM reason)</nametext></name>
       <fsummary>Raise a NIF error exception.</fsummary>
       <desc>
@@ -2848,7 +2896,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void *</ret>
+      <name since="OTP 20.2"><ret>void *</ret>
         <nametext>enif_realloc(void* ptr, size_t size)</nametext></name>
       <fsummary>Reallocate dynamic memory.</fsummary>
       <desc>
@@ -2862,7 +2910,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_realloc_binary(ErlNifBinary* bin, size_t size)</nametext>
       </name>
       <fsummary>Change the size of a binary.</fsummary>
@@ -2876,7 +2924,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since=""><ret>void</ret>
         <nametext>enif_release_binary(ErlNifBinary* bin)</nametext></name>
       <fsummary>Release a binary.</fsummary>
       <desc>
@@ -2887,7 +2935,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_release_resource(void* obj)</nametext></name>
       <fsummary>Release a resource object.</fsummary>
       <desc>
@@ -2902,11 +2950,15 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
           References made by <seealso marker="#enif_make_resource">
           <c>enif_make_resource</c></seealso>
           can only be removed by the garbage collector.</p>
+	<p>There are no guarantees exactly when the destructor of an
+	  unreferenced resource is called. It could be called directly by
+	  <c>enif_release_resource</c> but it could also be scheduled to be
+	  called at a later time possibly by another thread.</p>
       </desc>
     </func>
 
     <func>
-      <name><ret>ErlNifRWLock *</ret>
+      <name since="OTP R13B04"><ret>ErlNifRWLock *</ret>
         <nametext>enif_rwlock_create(char *name)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2916,7 +2968,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_rwlock_destroy(ErlNifRWLock *rwlck)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2926,7 +2978,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>char*</ret>
+      <name since="OTP 21.0"><ret>char*</ret>
         <nametext>enif_rwlock_name(ErlNifRWLock* rwlck)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2936,7 +2988,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_rwlock_rlock(ErlNifRWLock *rwlck)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2946,7 +2998,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_rwlock_runlock(ErlNifRWLock *rwlck)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2956,7 +3008,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_rwlock_rwlock(ErlNifRWLock *rwlck)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2966,7 +3018,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_rwlock_rwunlock(ErlNifRWLock *rwlck)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2976,7 +3028,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_rwlock_tryrlock(ErlNifRWLock *rwlck)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2986,7 +3038,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_rwlock_tryrwlock(ErlNifRWLock *rwlck)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -2996,7 +3048,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>ERL_NIF_TERM</ret><nametext>enif_schedule_nif(ErlNifEnv* env,
+      <name since="OTP 17.3"><ret>ERL_NIF_TERM</ret><nametext>enif_schedule_nif(ErlNifEnv* env,
         const char* fun_name, int flags, ERL_NIF_TERM (*fp)(ErlNifEnv* env, int
         argc, const ERL_NIF_TERM argv[]), int argc, const ERL_NIF_TERM
         argv[])</nametext></name>
@@ -3041,7 +3093,7 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 20.0"><ret>int</ret>
         <nametext>enif_select(ErlNifEnv* env, ErlNifEvent event, enum ErlNifSelectFlags mode,
 	void* obj, const ErlNifPid* pid, ERL_NIF_TERM ref)</nametext>
       </name>
@@ -3056,13 +3108,21 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
 	<p>Argument <c>mode</c> describes the type of events to wait for. It can be
 	  <c>ERL_NIF_SELECT_READ</c>, <c>ERL_NIF_SELECT_WRITE</c> or a bitwise
 	  OR combination to wait for both. It can also be <c>ERL_NIF_SELECT_STOP</c>
-	  which is described further below. When a read or write event is triggered,
+	  or <c>ERL_NIF_SELECT_CANCEL</c> which are described further
+	  below. When a read or write event is triggered,
 	  a notification message like this is sent to the process identified by
 	  <c>pid</c>:</p>
 	<code type="none">{select, Obj, Ref, ready_input | ready_output}</code>
 	<p><c>ready_input</c> or <c>ready_output</c> indicates if the event object
 	  is ready for reading or writing.</p>
-	<p>Argument <c>pid</c> may be <c>NULL</c> to indicate the calling process.</p>
+	<note><p>For complete control over the message format use the newer functions
+	  <seealso marker="#enif_select_read"><c>enif_select_read</c></seealso> or
+	  <seealso marker="#enif_select_write"><c>enif_select_write</c></seealso>
+	  introduced in erts-11.0 (OTP-22.0).</p>
+	</note>
+	<p>Argument <c>pid</c> may be <c>NULL</c> to indicate the calling
+	  process. It must not be set as <seealso marker="#enif_set_pid_undefined">
+	  undefined</seealso>.</p>
 	<p>Argument <c>obj</c> is a resource object obtained from
           <seealso marker="#enif_alloc_resource"><c>enif_alloc_resource</c></seealso>.
 	  The purpose of the resource objects is as a container of the event object
@@ -3073,17 +3133,29 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
 	  or the atom <c>undefined</c>. It will be passed as <c>Ref</c> in the notifications.
 	  If a selective <c>receive</c> statement is used to wait for the notification
 	  then a reference created just before the <c>receive</c> will exploit a runtime
-	  optimization that bypasses all earlier received messages in the queue.</p>
+	  optimization that bypasses all earlier received messages in the
+	  queue.</p>
 	<p>The notifications are one-shot only. To receive further notifications of the same
 	  type (read or write), repeated calls to <c>enif_select</c> must be made
 	  after receiving each notification.</p>
+	<p><c>ERL_NIF_SELECT_CANCEL</c> can be used to cancel previously
+	  selected events. It must be used in a bitwise OR combination with
+	  <c>ERL_NIF_SELECT_READ</c> and/or <c>ERL_NIF_SELECT_WRITE</c> to
+	  indicate which type of event to cancel. Arguments <c>pid</c> and
+	  <c>ref</c> are ignored when <c>ERL_NIF_SELECT_CANCEL</c> is specified.
+	  The return value will tell if the event was actualy cancelled or if a
+	  notification may already have been sent.</p>
 	<p>Use <c>ERL_NIF_SELECT_STOP</c> as <c>mode</c> in order to safely
 	  close an event object that has been passed to <c>enif_select</c>. The
 	  <seealso marker="#ErlNifResourceStop"><c>stop</c></seealso> callback
 	  of the resource <c>obj</c> will be called when it is safe to close
 	  the event object. This safe way of closing event objects must be used
-	  even if all notifications have been received and no further calls to
-	  <c>enif_select</c> have been made.</p>
+	  even if all notifications have been received (or cancelled) and no
+	  further calls to <c>enif_select</c> have been made.
+	  <c>ERL_NIF_SELECT_STOP</c> will first cancel any selected events
+	  before it calls or schedules the <c>stop</c> callback. Arguments
+	  <c>pid</c> and <c>ref</c> are ignored when <c>ERL_NIF_SELECT_STOP</c>
+	  is specified.</p>
 	<p>The first call to <c>enif_select</c> for a specific OS <c>event</c> will establish
 	  a relation between the event object and the containing resource. All subsequent calls
 	  for an <c>event</c> must pass its containing resource as argument
@@ -3105,7 +3177,15 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
           <item>The stop callback was called directly by <c>enif_select</c>.</item>
           <tag><c>ERL_NIF_SELECT_STOP_SCHEDULED</c></tag>
           <item>The stop callback was scheduled to run on some other thread
-	    or later by this thread.</item>
+	  or later by this thread.</item>
+	  <tag><c>ERL_NIF_SELECT_READ_CANCELLED</c></tag>
+          <item>A read event was cancelled by <c>ERL_NIF_SELECT_CANCEL</c> or
+	  <c>ERL_NIF_SELECT_STOP</c> and is guaranteed not to generate a
+	  <c>ready_input</c> notification message.</item>
+	  <tag><c>ERL_NIF_SELECT_WRITE_CANCELLED</c></tag>
+          <item>A write event was cancelled by <c>ERL_NIF_SELECT_CANCEL</c> or
+	  <c>ERL_NIF_SELECT_STOP</c> and is guaranteed not to generate a
+	  <c>ready_output</c> notification message.</item>
 	</taglist>
 	<p>Returns a negative value if the call failed where the following bits can be set:</p>
         <taglist>
@@ -3131,11 +3211,48 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
 }
 </code>
         </note>
+	<note><p>The mode flag <c>ERL_NIF_SELECT_CANCEL</c> and the return flags
+	  <c>ERL_NIF_SELECT_READ_CANCELLED</c> and
+	  <c>ERL_NIF_SELECT_WRITE_CANCELLED</c> were introduced in erts-11.0
+	  (OTP-22.0).</p>
+	</note>
       </desc>
     </func>
 
     <func>
-      <name><ret>ErlNifPid *</ret>
+      <name since="OTP 22.0"><ret>int</ret>
+      <nametext>enif_select_read(ErlNifEnv* env, ErlNifEvent event, void* obj,
+      const ErlNifPid* pid, ERL_NIF_TERM msg, ErlNifEnv* msg_env)</nametext>
+      </name>
+      <name since="OTP 22.0"><ret>int</ret>
+      <nametext>enif_select_write(ErlNifEnv* env, ErlNifEvent event, void* obj,
+      const ErlNifPid* pid, ERL_NIF_TERM msg, ErlNifEnv* msg_env)</nametext>
+      </name>
+      <fsummary>Manage subscription on IO event.</fsummary>
+      <desc>
+	<p>These are variants of <seealso marker="#enif_select">enif_select</seealso>
+	where you can supply your own message term <c>msg</c> that will be sent to
+	the process instead of the predefined tuple <c>{select,_,_,_}.</c></p>
+        <p>Argument <c>msg_env</c> must either be <c>NULL</c> or the environment of
+	<c>msg</c> allocated with <seealso marker="#enif_alloc_env">
+	<c>enif_alloc_env</c></seealso>. If argument <c>msg_env</c> is
+	<c>NULL</c> the term <c>msg</c> will be copied, otherwise both
+	<c>msg</c> and <c>msg_env</c> will be invalidated by a successful call
+	to <c>enif_select_read</c> or <c>enif_select_write</c>. The environment
+	is then to either be freed with <seealso marker="#enif_free_env">
+        <c>enif_free_env</c></seealso> or cleared for reuse with
+	<seealso marker="#enif_clear_env"><c>enif_clear_env</c></seealso>. An
+	unsuccessful call will leave <c>msg</c> and <c>msg_env</c> still valid.</p>
+	<p>Apart from the message format <c>enif_select_read</c> and
+	<c>enif_select_write</c> behaves exactly the same as <seealso
+	marker="#enif_select">enif_select</seealso> with argument <c>mode</c> as
+	either <c>ERL_NIF_SELECT_READ</c> or <c>ERL_NIF_SELECT_WRITE</c>. To
+	cancel or close events use <seealso marker="#enif_select">enif_select</seealso>.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name since="OTP R14B"><ret>ErlNifPid *</ret>
         <nametext>enif_self(ErlNifEnv* caller_env, ErlNifPid* pid)</nametext>
       </name>
       <fsummary>Get the pid of the calling process.</fsummary>
@@ -3148,8 +3265,8 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_send(ErlNifEnv* caller_env, ErlNifPid* to_pid,
-        ErlNifEnv* msg_env, ERL_NIF_TERM msg)</nametext></name>
+      <name since="OTP R14B"><ret>int</ret><nametext>enif_send(ErlNifEnv* caller_env,
+      ErlNifPid* to_pid, ErlNifEnv* msg_env, ERL_NIF_TERM msg)</nametext></name>
       <fsummary>Send a message to a process.</fsummary>
       <desc>
         <p>Sends a message to a process.</p>
@@ -3179,8 +3296,9 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
           <c>msg</c>) is invalidated by a successful call to <c>enif_send</c>.
           The environment is to either be freed with
           <seealso marker="#enif_free_env">
-          <c>enif_free_env</c></seealso> of cleared for reuse with
-          <seealso marker="#enif_clear_env"><c>enif_clear_env</c></seealso>.</p>
+          <c>enif_free_env</c></seealso> or cleared for reuse with
+          <seealso marker="#enif_clear_env"><c>enif_clear_env</c></seealso>. An
+	  unsuccessful call will leave <c>msg</c> and <c>msg_env</c> still valid.</p>
         <p>If <c>msg_env</c> is set to <c>NULL</c>, the <c>msg</c> term is
           copied and the original term and its environment is still valid after
           the call.</p>
@@ -3195,7 +3313,18 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>unsigned</ret>
+      <name since="OTP 22.0"><ret>void</ret>
+        <nametext>enif_set_pid_undefined(ErlNifPid* pid)</nametext></name>
+      <fsummary>Set pid as undefined.</fsummary>
+      <desc>
+        <p>Sets an <seealso marker="#ErlNifPid"><c>ErlNifPid</c></seealso>
+	variable as undefined. See <seealso marker="#enif_is_pid_undefined">
+	<c>enif_is_pid_undefined</c></seealso>.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name since="OTP R13B04"><ret>unsigned</ret>
         <nametext>enif_sizeof_resource(void* obj)</nametext></name>
       <fsummary>Get the byte size of a resource object.</fsummary>
       <desc>
@@ -3206,7 +3335,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_snprintf(char *str, size_t size, const
+      <name since="OTP 19.0"><ret>int</ret><nametext>enif_snprintf(char *str, size_t size, const
         char *format, ...)</nametext></name>
       <fsummary>Format strings and Erlang terms.</fsummary>
       <desc>
@@ -3220,7 +3349,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>void</ret><nametext>enif_system_info(ErlNifSysInfo
+      <name since="OTP R13B04"><ret>void</ret><nametext>enif_system_info(ErlNifSysInfo
         *sys_info_ptr, size_t size)</nametext></name>
       <fsummary>Get information about the Erlang runtime system.</fsummary>
       <desc>
@@ -3230,7 +3359,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret><nametext>enif_term_to_binary(ErlNifEnv *env,
+      <name since="OTP 19.0"><ret>int</ret><nametext>enif_term_to_binary(ErlNifEnv *env,
         ERL_NIF_TERM term, ErlNifBinary *bin)</nametext></name>
       <fsummary>Convert a term to the external format.</fsummary>
       <desc>
@@ -3247,7 +3376,49 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 22.0"><ret>ErlNifTermType</ret>
+        <nametext>enif_term_type(ErlNifEnv *env, ERL_NIF_TERM term)</nametext>
+      </name>
+      <fsummary>Determine the type of a term.</fsummary>
+      <desc>
+        <p>Determines the type of the given term. The term must be an ordinary
+          Erlang term and not one of the special terms returned by
+          <seealso marker="#enif_raise_exception">
+          <c>enif_raise_exception</c></seealso>,
+          <seealso marker="#enif_schedule_nif">
+          <c>enif_schedule_nif</c></seealso>, or similar.</p>
+        <p>The following types are defined at the moment:</p>
+        <taglist>
+          <tag><c>ERL_NIF_TERM_TYPE_ATOM</c></tag>
+          <item/>
+          <tag><c>ERL_NIF_TERM_TYPE_BITSTRING</c></tag>
+          <item><p>A bitstring or binary</p></item>
+          <tag><c>ERL_NIF_TERM_TYPE_FLOAT</c></tag>
+          <item/>
+          <tag><c>ERL_NIF_TERM_TYPE_FUN</c></tag>
+          <item/>
+          <tag><c>ERL_NIF_TERM_TYPE_INTEGER</c></tag>
+          <item/>
+          <tag><c>ERL_NIF_TERM_TYPE_LIST</c></tag>
+          <item><p>A list, empty or not</p></item>
+          <tag><c>ERL_NIF_TERM_TYPE_MAP</c></tag>
+          <item/>
+          <tag><c>ERL_NIF_TERM_TYPE_PID</c></tag>
+          <item/>
+          <tag><c>ERL_NIF_TERM_TYPE_PORT</c></tag>
+          <item/>
+          <tag><c>ERL_NIF_TERM_TYPE_REFERENCE</c></tag>
+          <item/>
+          <tag><c>ERL_NIF_TERM_TYPE_TUPLE</c></tag>
+          <item/>
+        </taglist>
+        <p>Note that new types may be added in the future, so the caller must
+          be prepared to handle unknown types.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_thread_create(char *name,ErlNifTid
         *tid,void * (*func)(void *),void *args,ErlNifThreadOpts
         *opts)</nametext></name>
@@ -3259,7 +3430,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_thread_exit(void *resp)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -3269,7 +3440,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_thread_join(ErlNifTid, void **respp)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -3279,7 +3450,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>char*</ret>
+      <name since="OTP 21.0"><ret>char*</ret>
         <nametext>enif_thread_name(ErlNifTid tid)</nametext></name>
       <fsummary>Thread name</fsummary>
       <desc>
@@ -3289,7 +3460,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>ErlNifThreadOpts *</ret>
+      <name since="OTP R13B04"><ret>ErlNifThreadOpts *</ret>
         <nametext>enif_thread_opts_create(char *name)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -3299,7 +3470,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_thread_opts_destroy(ErlNifThreadOpts *opts)</nametext>
       </name>
       <fsummary></fsummary>
@@ -3310,7 +3481,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>ErlNifTid</ret>
+      <name since="OTP R13B04"><ret>ErlNifTid</ret>
         <nametext>enif_thread_self(void)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -3320,7 +3491,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 19.0"><ret>int</ret>
       <nametext>enif_thread_type(void)</nametext></name>
       <fsummary>Determine type of current thread</fsummary>
       <desc>
@@ -3342,7 +3513,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>ErlNifTime</ret>
+      <name since="OTP 18.3"><ret>ErlNifTime</ret>
         <nametext>enif_time_offset(ErlNifTimeUnit time_unit)</nametext></name>
       <fsummary>Get current time offset.</fsummary>
       <desc>
@@ -3364,7 +3535,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>void *</ret>
+      <name since="OTP R13B04"><ret>void *</ret>
         <nametext>enif_tsd_get(ErlNifTSDKey key)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -3374,7 +3545,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP R13B04"><ret>int</ret>
         <nametext>enif_tsd_key_create(char *name, ErlNifTSDKey *key)</nametext>
       </name>
       <fsummary></fsummary>
@@ -3385,7 +3556,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
    </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_tsd_key_destroy(ErlNifTSDKey key)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -3395,7 +3566,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>void</ret>
+      <name since="OTP R13B04"><ret>void</ret>
         <nametext>enif_tsd_set(ErlNifTSDKey key, void *data)</nametext></name>
       <fsummary></fsummary>
       <desc>
@@ -3405,7 +3576,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 21.0"><ret>int</ret>
       <nametext>enif_vfprintf(FILE *stream, const char *format, va_list ap)
       </nametext></name>
       <fsummary>Format strings and Erlang terms.</fsummary>
@@ -3417,7 +3588,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 21.0"><ret>int</ret>
       <nametext>enif_vsnprintf(char *str, size_t size, const char *format, va_list ap)
       </nametext></name>
       <fsummary>Format strings and Erlang terms.</fsummary>
@@ -3429,7 +3600,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 20.0"><ret>int</ret>
         <nametext>enif_whereis_pid(ErlNifEnv *env,
           ERL_NIF_TERM name, ErlNifPid *pid)</nametext></name>
       <fsummary>Looks up a process by its registered name.</fsummary>
@@ -3457,7 +3628,7 @@ if (retval &amp; ERL_NIF_SELECT_STOP_CALLED) {
     </func>
 
     <func>
-      <name><ret>int</ret>
+      <name since="OTP 20.0"><ret>int</ret>
         <nametext>enif_whereis_port(ErlNifEnv *env,
           ERL_NIF_TERM name, ErlNifPort *port)</nametext></name>
       <fsummary>Looks up a port by its registered name.</fsummary>
diff --git a/erts/doc/src/erl_prim_loader.xml b/erts/doc/src/erl_prim_loader.xml
index 286bac6c93..043d11b7b4 100644
--- a/erts/doc/src/erl_prim_loader.xml
+++ b/erts/doc/src/erl_prim_loader.xml
@@ -29,7 +29,7 @@
     <rev></rev>
     <file>erl_prim_loader.xml</file>
   </header>
-  <module>erl_prim_loader</module>
+  <module since="">erl_prim_loader</module>
   <modulesummary>Low-level Erlang loader.</modulesummary>
   <description>
     <p>This module is used to load all Erlang modules into
@@ -47,7 +47,7 @@
 
   <funcs>
     <func>
-      <name name="get_file" arity="1"/>
+      <name name="get_file" arity="1" since=""/>
       <fsummary>Get a file.</fsummary>
       <desc>
         <p>Fetches a file using the low-level loader.
@@ -65,7 +65,7 @@
     </func>
 
     <func>
-      <name name="get_path" arity="0"/>
+      <name name="get_path" arity="0" since=""/>
       <fsummary>Get the path set in the loader.</fsummary>
       <desc>
         <p>Gets the path set in the loader. The path is
@@ -75,7 +75,7 @@
     </func>
 
     <func>
-      <name name="list_dir" arity="1"/>
+      <name name="list_dir" arity="1" since=""/>
       <fsummary>List files in a directory.</fsummary>
       <desc>
         <p>Lists all the files in a directory. Returns
@@ -92,7 +92,7 @@
     </func>
 
     <func>
-      <name name="read_file_info" arity="1"/>
+      <name name="read_file_info" arity="1" since=""/>
       <fsummary>Get information about a file.</fsummary>
       <desc>
         <p>Retrieves information about a file. Returns
@@ -114,7 +114,7 @@
     </func>
 
     <func>
-      <name name="read_link_info" arity="1"/>
+      <name name="read_link_info" arity="1" since="OTP 17.1.2"/>
       <fsummary>Get information about a link or file.</fsummary>
       <desc>
         <p>Works like
@@ -131,7 +131,7 @@
     </func>
 
     <func>
-      <name name="set_path" arity="1"/>
+      <name name="set_path" arity="1" since=""/>
       <fsummary>Set the path of the loader.</fsummary>
       <desc>
         <p>Sets the path of the loader if
diff --git a/erts/doc/src/erl_tracer.xml b/erts/doc/src/erl_tracer.xml
index fd3c17f337..fa4717bc2f 100644
--- a/erts/doc/src/erl_tracer.xml
+++ b/erts/doc/src/erl_tracer.xml
@@ -28,7 +28,7 @@
     <date></date>
     <rev></rev>
   </header>
-  <module>erl_tracer</module>
+  <module since="OTP 19.0">erl_tracer</module>
   <modulesummary>Erlang tracer behavior.</modulesummary>
   <description>
     <p>This behavior module implements the back end of the Erlang
@@ -195,7 +195,7 @@
 
   <funcs>
     <func>
-      <name>Module:enabled(TraceTag, TracerState, Tracee) -> Result</name>
+      <name since="OTP 19.0">Module:enabled(TraceTag, TracerState, Tracee) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
         <v>TraceTag = <seealso marker="#type-trace_tag">
@@ -224,7 +224,7 @@
     </func>
 
     <func>
-      <name>Module:enabled_call(TraceTag, TracerState, Tracee) -> Result</name>
+      <name since="OTP 19.0">Module:enabled_call(TraceTag, TracerState, Tracee) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
         <v>TraceTag = <seealso marker="#type-trace_tag_call">
@@ -244,7 +244,7 @@
     </func>
 
     <func>
-      <name>Module:enabled_garbage_collection(TraceTag, TracerState, Tracee) -> Result</name>
+      <name since="OTP 19.0">Module:enabled_garbage_collection(TraceTag, TracerState, Tracee) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
         <v>TraceTag = <seealso marker="#type-trace_tag_gc">
@@ -264,7 +264,7 @@
     </func>
 
     <func>
-      <name>Module:enabled_ports(TraceTag, TracerState, Tracee) -> Result</name>
+      <name since="OTP 19.0">Module:enabled_ports(TraceTag, TracerState, Tracee) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
         <v>TraceTag = <seealso marker="#type-trace_tag_ports">
@@ -284,7 +284,7 @@
     </func>
 
     <func>
-      <name>Module:enabled_procs(TraceTag, TracerState, Tracee) -> Result</name>
+      <name since="OTP 19.0">Module:enabled_procs(TraceTag, TracerState, Tracee) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
         <v>TraceTag = <seealso marker="#type-trace_tag_procs">
@@ -304,7 +304,7 @@
     </func>
 
     <func>
-      <name>Module:enabled_receive(TraceTag, TracerState, Tracee) -> Result
+      <name since="OTP 19.0">Module:enabled_receive(TraceTag, TracerState, Tracee) -> Result
       </name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -325,7 +325,7 @@
     </func>
 
     <func>
-      <name>Module:enabled_running_ports(TraceTag, TracerState, Tracee) ->
+      <name since="OTP 19.0">Module:enabled_running_ports(TraceTag, TracerState, Tracee) ->
         Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -346,7 +346,7 @@
     </func>
 
     <func>
-      <name>Module:enabled_running_procs(TraceTag, TracerState, Tracee) ->
+      <name since="OTP 19.0">Module:enabled_running_procs(TraceTag, TracerState, Tracee) ->
         Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -368,7 +368,7 @@
     </func>
 
     <func>
-      <name>Module:enabled_send(TraceTag, TracerState, Tracee) -> Result</name>
+      <name since="OTP 19.0">Module:enabled_send(TraceTag, TracerState, Tracee) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
         <v>TraceTag = <seealso marker="#type-trace_tag_send">
@@ -388,7 +388,7 @@
     </func>
 
     <func>
-      <name>Module:trace(TraceTag, TracerState, Tracee, TraceTerm,
+      <name since="OTP 19.0">Module:trace(TraceTag, TracerState, Tracee, TraceTerm,
         Opts) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -417,7 +417,7 @@
     </func>
 
     <func>
-      <name name="trace">Module:trace(seq_trace, TracerState, Label,
+      <name name="trace" since="OTP 19.0">Module:trace(seq_trace, TracerState, Label,
         SeqTraceInfo, Opts) -> Result</name>
       <fsummary>Check if a sequence trace event is to be generated.</fsummary>
       <type>
@@ -439,7 +439,7 @@
     </func>
 
     <func>
-      <name>Module:trace_call(TraceTag, TracerState, Tracee, TraceTerm,
+      <name since="OTP 19.0">Module:trace_call(TraceTag, TracerState, Tracee, TraceTerm,
           Opts) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -463,7 +463,7 @@
     </func>
 
     <func>
-      <name>Module:trace_garbage_collection(TraceTag, TracerState, Tracee,
+      <name since="OTP 19.0">Module:trace_garbage_collection(TraceTag, TracerState, Tracee,
         TraceTerm, Opts) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -487,7 +487,7 @@
     </func>
 
     <func>
-      <name>Module:trace_ports(TraceTag, TracerState, Tracee, TraceTerm,
+      <name since="OTP 19.0">Module:trace_ports(TraceTag, TracerState, Tracee, TraceTerm,
         Opts) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -511,7 +511,7 @@
     </func>
 
     <func>
-      <name>Module:trace_procs(TraceTag, TracerState, Tracee, TraceTerm,
+      <name since="OTP 19.0">Module:trace_procs(TraceTag, TracerState, Tracee, TraceTerm,
         Opts) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -535,7 +535,7 @@
     </func>
 
     <func>
-      <name>Module:trace_receive(TraceTag, TracerState, Tracee, TraceTerm,
+      <name since="OTP 19.0">Module:trace_receive(TraceTag, TracerState, Tracee, TraceTerm,
         Opts) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -559,7 +559,7 @@
     </func>
 
     <func>
-      <name>Module:trace_running_ports(TraceTag, TracerState, Tracee,
+      <name since="OTP 19.0">Module:trace_running_ports(TraceTag, TracerState, Tracee,
         TraceTerm, Opts) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -583,7 +583,7 @@
     </func>
 
     <func>
-      <name>Module:trace_running_procs(TraceTag, TracerState, Tracee,
+      <name since="OTP 19.0">Module:trace_running_procs(TraceTag, TracerState, Tracee,
         TraceTerm, Opts) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
@@ -607,7 +607,7 @@
     </func>
 
     <func>
-      <name>Module:trace_send(TraceTag, TracerState, Tracee, TraceTerm,
+      <name since="OTP 19.0">Module:trace_send(TraceTag, TracerState, Tracee, TraceTerm,
         Opts) -> Result</name>
       <fsummary>Check if a trace event is to be generated.</fsummary>
       <type>
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 8e014c3010..2183f75487 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -29,7 +29,7 @@
     <rev></rev>
     <file>erlang.xml</file>
   </header>
-  <module>erlang</module>
+  <module since="">erlang</module>
   <modulesummary>The Erlang BIFs.</modulesummary>
   <description>
     <p>By convention, most Built-In Functions (BIFs) are included
@@ -126,7 +126,7 @@
               instance.</p>
             <p>One can get an approximation of the <c>native</c>
               time unit by calling
-              <seealso marker="erlang:convert_time_unit/3">
+              <seealso marker="#convert_time_unit/3">
               <c>erlang:convert_time_unit(1, second, native)</c></seealso>.
               The result equals the number
               of whole <c>native</c> time units per second. If
@@ -210,8 +210,8 @@
 
   <funcs>
     <func>
-      <name name="abs" arity="1" clause_i="1"/>
-      <name name="abs" arity="1" clause_i="2"/>
+      <name name="abs" arity="1" clause_i="1" since=""/>
+      <name name="abs" arity="1" clause_i="2" since=""/>
       <fsummary>Arithmetical absolute value.</fsummary>
       <desc>
         <p>Returns an integer or float that is the arithmetical
@@ -227,7 +227,7 @@
     </func>
 
     <func>
-      <name name="adler32" arity="1"/>
+      <name name="adler32" arity="1" since=""/>
       <fsummary>Compute adler32 checksum.</fsummary>
       <desc>
         <p>Computes and returns the adler32 checksum for
@@ -236,7 +236,7 @@
     </func>
 
     <func>
-      <name name="adler32" arity="2"/>
+      <name name="adler32" arity="2" since=""/>
       <fsummary>Compute adler32 checksum.</fsummary>
       <desc>
         <p>Continues computing the adler32 checksum by combining 
@@ -253,7 +253,7 @@ Y = erlang:adler32([Data1,Data2]).</code>
     </func>
 
     <func>
-      <name name="adler32_combine" arity="3"/>
+      <name name="adler32_combine" arity="3" since=""/>
       <fsummary>Combine two adler32 checksums.</fsummary>
       <desc>
         <p>Combines two previously computed adler32 checksums.
@@ -272,7 +272,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="append_element" arity="2"/>
+      <name name="append_element" arity="2" since=""/>
       <fsummary>Append an extra element to a tuple.</fsummary>
       <desc>
         <p>Returns a new tuple that has one element more than
@@ -289,7 +289,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="apply" arity="2"/>
+      <name name="apply" arity="2" since=""/>
       <fsummary>Apply a function to an argument list.</fsummary>
       <desc>
         <p>Calls a fun, passing the elements in <c><anno>Args</anno></c>
@@ -307,7 +307,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="apply" arity="3"/>
+      <name name="apply" arity="3" since=""/>
       <fsummary>Apply a function to an argument list.</fsummary>
       <desc>
         <p>Returns the result of applying <c>Function</c> in
@@ -337,7 +337,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="atom_to_binary" arity="2"/>
+      <name name="atom_to_binary" arity="2" since=""/>
       <fsummary>Return the binary representation of an atom.</fsummary>
       <desc>
         <p>Returns a binary corresponding to the text
@@ -362,7 +362,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="atom_to_list" arity="1"/>
+      <name name="atom_to_list" arity="1" since=""/>
       <fsummary>Text representation of an atom.</fsummary>
       <desc>
         <p>Returns a string corresponding to the text
@@ -374,7 +374,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_part" arity="2"/>
+      <name name="binary_part" arity="2" since="OTP R14B"/>
       <fsummary>Extract a part of a binary.</fsummary>
       <desc>
       <p>Extracts the part of the binary described by
@@ -399,7 +399,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_part" arity="3"/>
+      <name name="binary_part" arity="3" since="OTP R14B"/>
       <fsummary>Extract a part of a binary.</fsummary>
       <desc>
       <p>The same as <c>binary_part(<anno>Subject</anno>,
@@ -409,7 +409,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_to_atom" arity="2"/>
+      <name name="binary_to_atom" arity="2" since=""/>
       <fsummary>Convert from text representation to an atom.</fsummary>
       <desc>
         <p>Returns the atom whose text representation is
@@ -438,7 +438,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_to_existing_atom" arity="2"/>
+      <name name="binary_to_existing_atom" arity="2" since=""/>
       <fsummary>Convert from text representation to an atom.</fsummary>
       <desc>
         <p>As
@@ -459,7 +459,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_to_float" arity="1"/>
+      <name name="binary_to_float" arity="1" since="OTP R16B"/>
       <fsummary>Convert from text representation to a float.</fsummary>
       <desc>
         <p>Returns the float whose text representation is
@@ -473,7 +473,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_to_integer" arity="1"/>
+      <name name="binary_to_integer" arity="1" since="OTP R16B"/>
       <fsummary>Convert from text representation to an integer.</fsummary>
       <desc>
         <p>Returns an integer whose text representation is
@@ -487,7 +487,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_to_integer" arity="2"/>
+      <name name="binary_to_integer" arity="2" since="OTP R16B"/>
       <fsummary>Convert from text representation to an integer.</fsummary>
       <desc>
         <p>Returns an integer whose text representation in base
@@ -502,7 +502,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_to_list" arity="1"/>
+      <name name="binary_to_list" arity="1" since=""/>
       <fsummary>Convert a binary to a list.</fsummary>
       <desc>
         <p>Returns a list of integers corresponding to the bytes of
@@ -511,7 +511,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_to_list" arity="3"/>
+      <name name="binary_to_list" arity="3" since=""/>
       <fsummary>Convert part of a binary to a list.</fsummary>
       <type_desc variable="Start">1..byte_size(<c><anno>Binary</anno></c>)
       </type_desc>
@@ -533,7 +533,7 @@ Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="binary_to_term" arity="1"/>
+      <name name="binary_to_term" arity="1" since=""/>
       <fsummary>Decode an Erlang external term format binary.</fsummary>
       <desc>
         <p>Returns an Erlang term that is the result of decoding
@@ -559,7 +559,7 @@ hello
     </func>
 
     <func>
-      <name name="binary_to_term" arity="2"/>
+      <name name="binary_to_term" arity="2" since="OTP R13B04"/>
       <fsummary>Decode an Erlang external term format binary.</fsummary>
       <desc>
         <p>As <c>binary_to_term/1</c>, but takes these options:</p>
@@ -613,7 +613,7 @@ hello
     </func>
 
     <func>
-      <name name="bit_size" arity="1"/>
+      <name name="bit_size" arity="1" since=""/>
       <fsummary>Return the size of a bitstring.</fsummary>
       <desc>
         <p>Returns an integer that is the size in bits of
@@ -628,7 +628,7 @@ hello
     </func>
 
     <func>
-      <name name="bitstring_to_list" arity="1"/>
+      <name name="bitstring_to_list" arity="1" since=""/>
       <fsummary>Convert a bitstring to a list.</fsummary>
       <desc>
         <p>Returns a list of integers corresponding to the bytes of
@@ -639,7 +639,7 @@ hello
     </func>
 
     <func>
-      <name name="bump_reductions" arity="1"/>
+      <name name="bump_reductions" arity="1" since=""/>
       <fsummary>Increment the reduction counter.</fsummary>
       <desc>
         <p>This implementation-dependent function increments
@@ -657,7 +657,7 @@ hello
     </func>
 
     <func>
-      <name name="byte_size" arity="1"/>
+      <name name="byte_size" arity="1" since=""/>
       <fsummary>Return the size of a bitstring (or binary).</fsummary>
       <desc>
         <p>Returns an integer that is the number of bytes needed to
@@ -674,7 +674,7 @@ hello
     </func>
 
     <func>
-      <name name="cancel_timer" arity="1"/>
+      <name name="cancel_timer" arity="1" since=""/>
       <fsummary>Cancel a timer.</fsummary>
       <desc>
         <p>Cancels a timer. The same as calling
@@ -684,7 +684,7 @@ hello
     </func>
 
     <func>
-      <name name="cancel_timer" arity="2"/>
+      <name name="cancel_timer" arity="2" since="OTP 18.0"/>
       <fsummary>Cancel a timer.</fsummary>
       <desc>
         <p>Cancels a timer that has been created by
@@ -766,7 +766,7 @@ hello
     </func>
 
     <func>
-      <name name="ceil" arity="1"/>
+      <name name="ceil" arity="1" since="OTP 20.0"/>
       <fsummary>Returns the smallest integer not less than the argument</fsummary>
       <desc>
         <p>Returns the smallest integer not less than
@@ -779,7 +779,7 @@ hello
       </desc>
     </func>
     <func>
-      <name name="check_old_code" arity="1"/>
+      <name name="check_old_code" arity="1" since="OTP R14B04"/>
       <fsummary>Check if a module has old code.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Module</anno></c> has old code,
@@ -790,7 +790,7 @@ hello
     </func>
 
     <func>
-      <name name="check_process_code" arity="2"/>
+      <name name="check_process_code" arity="2" since=""/>
       <fsummary>Check if a process executes old code for a module.</fsummary>
       <desc>
         <p>The same as
@@ -801,7 +801,7 @@ hello
     </func>
 
     <func>
-      <name name="check_process_code" arity="3"/>
+      <name name="check_process_code" arity="3" since="OTP 17.0"/>
       <fsummary>Check if a process executes old code for a module.</fsummary>
       <desc>
         <p>Checks if the node local process identified by
@@ -904,7 +904,7 @@ hello
     </func>
 
     <func>
-      <name name="convert_time_unit" arity="3"/>
+      <name name="convert_time_unit" arity="3" since="OTP 18.0"/>
       <fsummary>Convert time unit of a time value.</fsummary>
       <desc>
         <p>Converts the <c><anno>Time</anno></c> value of time unit
@@ -922,7 +922,7 @@ hello
     </func>
 
     <func>
-      <name name="crc32" arity="1"/>
+      <name name="crc32" arity="1" since=""/>
       <fsummary>Compute crc32 (IEEE 802.3) checksum.</fsummary>
       <desc>
         <p>Computes and returns the crc32 (IEEE 802.3 style) checksum
@@ -931,7 +931,7 @@ hello
     </func>
 
     <func>
-      <name name="crc32" arity="2"/>
+      <name name="crc32" arity="2" since=""/>
       <fsummary>Compute crc32 (IEEE 802.3) checksum.</fsummary>
       <desc>
         <p>Continues computing the crc32 checksum by combining
@@ -948,7 +948,7 @@ Y = erlang:crc32([Data1,Data2]).</code>
     </func>
 
     <func>
-      <name name="crc32_combine" arity="3"/>
+      <name name="crc32_combine" arity="3" since=""/>
       <fsummary>Combine two crc32 (IEEE 802.3) checksums.</fsummary>
       <desc>
         <p>Combines two previously computed crc32 checksums.
@@ -967,7 +967,7 @@ Z = erlang:crc32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="date" arity="0"/>
+      <name name="date" arity="0" since=""/>
       <fsummary>Current date.</fsummary>
       <desc>
         <p>Returns the current date as <c>{Year, Month, Day}</c>.</p>
@@ -980,7 +980,7 @@ Z = erlang:crc32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="decode_packet" arity="3"/>
+      <name name="decode_packet" arity="3" since=""/>
       <fsummary>Extract a protocol packet from a binary.</fsummary>
       <desc>
         <p>Decodes the binary <c><anno>Bin</anno></c> according to the packet
@@ -1090,7 +1090,7 @@ Z = erlang:crc32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="delete_element" arity="2"/>
+      <name name="delete_element" arity="2" since="OTP R16B"/>
       <fsummary>Delete element at index in a tuple.</fsummary>
       <type_desc variable="Index">1..tuple_size(<anno>Tuple1</anno>)</type_desc>
       <desc>
@@ -1103,7 +1103,7 @@ Z = erlang:crc32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="delete_module" arity="1"/>
+      <name name="delete_module" arity="1" since=""/>
       <fsummary>Make the current code for a module old.</fsummary>
       <desc>
         <p>Makes the current code for <c><anno>Module</anno></c> become old
@@ -1121,7 +1121,7 @@ Z = erlang:crc32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="demonitor" arity="1"/>
+      <name name="demonitor" arity="1" since=""/>
       <fsummary>Stop monitoring.</fsummary>
       <desc>
         <p>If <c><anno>MonitorRef</anno></c> is a reference that the
@@ -1163,7 +1163,7 @@ Z = erlang:crc32_combine(X,Y,iolist_size(Data2)).</code>
     </func>
 
     <func>
-      <name name="demonitor" arity="2"/>
+      <name name="demonitor" arity="2" since=""/>
       <fsummary>Stop monitoring.</fsummary>
       <desc>
         <p>The returned value is <c>true</c> unless <c>info</c> is part
@@ -1231,7 +1231,7 @@ end</code>
     </func>
 
     <func>
-      <name name="disconnect_node" arity="1"/>
+      <name name="disconnect_node" arity="1" since=""/>
       <fsummary>Force the disconnection of a node.</fsummary>
       <desc>
         <p>Forces the disconnection of a node. This appears to
@@ -1245,7 +1245,7 @@ end</code>
     </func>
 
     <func>
-      <name name="display" arity="1"/>
+      <name name="display" arity="1" since=""/>
       <fsummary>Print a term on standard output.</fsummary>
       <desc>
         <p>Prints a text representation of <c><anno>Term</anno></c> on the
@@ -1257,7 +1257,7 @@ end</code>
     </func>
 
     <func>
-      <name name="dist_ctrl_get_data" arity="1"/>
+      <name name="dist_ctrl_get_data" arity="1" since="OTP 21.0"/>
       <fsummary>Get distribution channel data to pass to another node.</fsummary>
       <desc>
         <p>
@@ -1269,6 +1269,13 @@ end</code>
 	  data is available by calling
 	  <seealso marker="erlang#dist_ctrl_get_data_notification/1"><c>erlang:dist_ctrl_get_data_notification(DHandle)</c></seealso>.
 	</p>
+	<p>The returned value when there are data available depends
+	on the value of the <c>get_size</c> option configured on the
+	distribution channel identified by <c><anno>DHandle</anno></c>.
+	For more information see the documentation of the <c>get_size</c>
+	option for the
+	<seealso marker="#dist_ctrl_set_opt/3"><c>erlang:dist_ctrl_set_opt/3</c></seealso>
+	function.</p>
 	<note><p>
 	  Only the process registered as distribution
 	  controller for the distribution channel identified by
@@ -1290,7 +1297,36 @@ end</code>
     </func>
 
     <func>
-      <name name="dist_ctrl_get_data_notification" arity="1"/>
+      <name name="dist_ctrl_get_opt" arity="2" clause_i="1" since="OTP 22.0"/>
+      <fsummary>Get value of the get_size option on a distribution channel</fsummary>
+      <desc>
+	<p>Returns the value of the <c>get_size</c> option on the distribution channel
+	identified by <c><anno>DHandle</anno></c>. For more information see the
+	documentation of the <c>get_size</c> option for the
+	<seealso marker="#dist_ctrl_set_opt/3"><c>erlang:dist_ctrl_set_opt/3</c></seealso>
+	function.</p>
+	<note><p>
+	  Only the process registered as distribution
+	  controller for the distribution channel identified by
+	  <c><anno>DHandle</anno></c> is allowed to call this
+	  function.
+	</p></note>
+	<p>
+	  This function is used when implementing an alternative
+	  distribution carrier using processes as distribution
+	  controllers. <c><anno>DHandle</anno></c> is retrived
+	  via the callback
+	  <seealso marker="erts:alt_dist#hs_data_f_handshake_complete"><c>f_handshake_complete</c></seealso>.
+	  More information can be found in the documentation of
+	  <seealso marker="erts:alt_dist#distribution_module">ERTS
+	  User's Guide ➜ How to implement an Alternative Carrier
+	  for the Erlang Distribution ➜ Distribution Module</seealso>.
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="dist_ctrl_get_data_notification" arity="1" since="OTP 21.0"/>
       <fsummary>Request notification about available outgoing distribution channel data.</fsummary>
       <desc>
         <p>
@@ -1326,7 +1362,7 @@ end</code>
     </func>
 
     <func>
-      <name name="dist_ctrl_input_handler" arity="2"/>
+      <name name="dist_ctrl_input_handler" arity="2" since="OTP 21.0"/>
       <fsummary>Register distribution channel input handler process.</fsummary>
       <desc>
         <p>
@@ -1359,7 +1395,7 @@ end</code>
     </func>
 
     <func>
-      <name name="dist_ctrl_put_data" arity="2"/>
+      <name name="dist_ctrl_put_data" arity="2" since="OTP 21.0"/>
       <fsummary>Pass data into the VM from a distribution channel.</fsummary>
       <desc>
         <p>
@@ -1392,7 +1428,56 @@ end</code>
     </func>
 
     <func>
-      <name name="element" arity="2"/>
+      <name name="dist_ctrl_set_opt" arity="3" clause_i="1" since="OTP 22.0"/>
+      <fsummary>Set value of the get_size option on a distribution channel</fsummary>
+      <desc>
+        <p>Sets the value of the <c>get_size</c> option on the distribution channel
+	identified by <c><anno>DHandle</anno></c>. This option controls the return
+	value of calls to
+	<seealso marker="#dist_ctrl_get_data/1">erlang:dist_ctrl_get_data(<anno>DHandle</anno>)</seealso>
+	where <c><anno>DHandle</anno></c> equals <c><anno>DHandle</anno></c> used
+	when setting this option.
+	When the <c>get_size</c> option is:</p>
+	<taglist>
+	  <tag><c>false</c></tag>
+	  <item>
+	    and there are distribution data available, a call to
+	    <c>erlang:dist_ctrl_get_data(<anno>DHandle</anno>)</c>
+	    will just return <c>Data</c> to pass over the channel.
+	    This is the default value of the <c>get_size</c> option.
+	  </item>
+	  <tag><c>true</c></tag>
+	  <item>
+	    and there are distribution data available, a call to
+	    <c>erlang:dist_ctrl_get_data(<anno>DHandle</anno>)</c>
+	    will return <c>Data</c> to pass over the channel as well as
+	    the <c>Size</c> of <c>Data</c> in bytes. This is returned as
+	    a tuple on the form <c>{Size, Data}</c>.
+	  </item>
+	</taglist>
+	<p>All options are set to default when a channel is closed.</p>
+	<note><p>
+	  Only the process registered as distribution
+	  controller for the distribution channel identified by
+	  <c><anno>DHandle</anno></c> is allowed to call this
+	  function.
+	</p></note>
+	<p>
+	  This function is used when implementing an alternative
+	  distribution carrier using processes as distribution
+	  controllers. <c><anno>DHandle</anno></c> is retrived
+	  via the callback
+	  <seealso marker="erts:alt_dist#hs_data_f_handshake_complete"><c>f_handshake_complete</c></seealso>.
+	  More information can be found in the documentation of
+	  <seealso marker="erts:alt_dist#distribution_module">ERTS
+	  User's Guide ➜ How to implement an Alternative Carrier
+	  for the Erlang Distribution ➜ Distribution Module</seealso>.
+	</p>
+      </desc>
+    </func>
+    
+    <func>
+      <name name="element" arity="2" since=""/>
       <fsummary>Return the Nth element of a tuple.</fsummary>
       <type_desc variable="N">1..tuple_size(<anno>Tuple</anno>)</type_desc>
       <desc>
@@ -1406,7 +1491,7 @@ b</pre>
     </func>
 
     <func>
-      <name name="erase" arity="0"/>
+      <name name="erase" arity="0" since=""/>
       <fsummary>Return and delete the process dictionary.</fsummary>
       <desc>
         <p>Returns the process dictionary and deletes it, for
@@ -1420,7 +1505,7 @@ b</pre>
     </func>
 
     <func>
-      <name name="erase" arity="1"/>
+      <name name="erase" arity="1" since=""/>
       <fsummary>Return and delete a value from the process dictionary.
       </fsummary>
       <desc>
@@ -1437,7 +1522,7 @@ b</pre>
     </func>
 
     <func>
-      <name name="error" arity="1"/>
+      <name name="error" arity="1" since=""/>
       <fsummary>Stop execution with a specified reason.</fsummary>
       <desc>
         <p>Stops the execution of the calling process with the reason
@@ -1461,7 +1546,7 @@ b</pre>
     </func>
 
     <func>
-      <name name="error" arity="2"/>
+      <name name="error" arity="2" since=""/>
       <fsummary>Stop execution with a specified reason.</fsummary>
       <desc>
         <p>Stops the execution of the calling process with the reason
@@ -1478,7 +1563,7 @@ b</pre>
     </func>
 
     <func>
-      <name name="exit" arity="1"/>
+      <name name="exit" arity="1" since=""/>
       <fsummary>Stop execution with a specified reason.</fsummary>
       <desc>
         <p>Stops the execution of the calling process with exit reason
@@ -1495,7 +1580,7 @@ b</pre>
     </func>
 
     <func>
-      <name name="exit" arity="2"/>
+      <name name="exit" arity="2" since=""/>
       <fsummary>Send an exit signal to a process or a port.</fsummary>
       <desc>
         <p>Sends an exit signal with exit reason <c><anno>Reason</anno></c> to
@@ -1531,7 +1616,7 @@ b</pre>
     </func>
 
     <func>
-      <name name="external_size" arity="1"/>
+      <name name="external_size" arity="1" since="OTP R14B04"/>
       <fsummary>Calculate the maximum size for a term encoded in the Erlang
         external term format.</fsummary>
       <desc>
@@ -1550,7 +1635,7 @@ erlang:external_size(<anno>Term</anno>, [])</code>
     </func>
 
     <func>
-      <name name="external_size" arity="2"/>
+      <name name="external_size" arity="2" since="OTP R14B04"/>
       <fsummary>Calculate the maximum size for a term encoded in the Erlang
         external term format.</fsummary>
       <desc>
@@ -1570,7 +1655,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="float" arity="1"/>
+      <name name="float" arity="1" since=""/>
       <fsummary>Convert a number to a float.</fsummary>
       <desc>
         <p>Returns a float by converting <c><anno>Number</anno></c> to a float,
@@ -1592,7 +1677,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="float_to_binary" arity="1"/>
+      <name name="float_to_binary" arity="1" since="OTP R16B"/>
       <fsummary>Text representation of a float.</fsummary>
       <desc>
         <p>The same as
@@ -1601,7 +1686,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="float_to_binary" arity="2"/>
+      <name name="float_to_binary" arity="2" since="OTP R16B"/>
       <fsummary>Text representation of a float formatted using specified
         options.</fsummary>
       <desc>
@@ -1619,7 +1704,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="float_to_list" arity="1"/>
+      <name name="float_to_list" arity="1" since=""/>
       <fsummary>Text representation of a float.</fsummary>
       <desc>
         <p>The same as
@@ -1628,7 +1713,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="float_to_list" arity="2"/>
+      <name name="float_to_list" arity="2" since="OTP R16B"/>
       <fsummary>Text representation of a float formatted using specified
         options.</fsummary>
       <desc>
@@ -1664,7 +1749,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="floor" arity="1"/>
+      <name name="floor" arity="1" since="OTP 20.0"/>
       <fsummary>Returns the largest integer not greater than the argument</fsummary>
       <desc>
         <p>Returns the largest integer not greater than
@@ -1678,7 +1763,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="fun_info" arity="1"/>
+      <name name="fun_info" arity="1" since=""/>
       <fsummary>Information about a fun.</fsummary>
       <desc>
         <p>Returns a list with information about the fun
@@ -1751,6 +1836,10 @@ true</pre>
           <item>
             <p><c>Pid</c> is the process identifier of the process
               that originally created the fun.</p>
+            <p>It might point to the <c>init</c> process if the
+              <c>Fun</c> was statically allocated when module was
+              loaded (this optimisation is performed for local
+              functions that do not capture the enviornment).</p>
           </item>
           <tag><c>{index, Index}</c></tag>
           <item>
@@ -1779,7 +1868,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="fun_info" arity="2"/>
+      <name name="fun_info" arity="2" since=""/>
       <fsummary>Information about a fun.</fsummary>
       <type name="fun_info_item"/>
       <desc>
@@ -1799,7 +1888,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="fun_to_list" arity="1"/>
+      <name name="fun_to_list" arity="1" since=""/>
       <fsummary>Text representation of a fun.</fsummary>
       <desc>
         <p>Returns a string corresponding to the text
@@ -1808,7 +1897,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="function_exported" arity="3"/>
+      <name name="function_exported" arity="3" since=""/>
       <fsummary>Check if a function is exported and loaded.</fsummary>
       <desc>
         <p>Returns <c>true</c> if the module <c><anno>Module</anno></c> is
@@ -1824,7 +1913,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="garbage_collect" arity="0"/>
+      <name name="garbage_collect" arity="0" since=""/>
       <fsummary>Force an immediate garbage collection of the calling process.
       </fsummary>
       <desc>
@@ -1840,7 +1929,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="garbage_collect" arity="1"/>
+      <name name="garbage_collect" arity="1" since=""/>
       <fsummary>Garbage collect a process.</fsummary>
       <desc>
         <p>The same as
@@ -1850,7 +1939,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="garbage_collect" arity="2"/>
+      <name name="garbage_collect" arity="2" since="OTP 17.0"/>
       <fsummary>Garbage collect a process.</fsummary>
       <desc>
         <p>Garbage collects the node local process identified by
@@ -1915,7 +2004,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="get" arity="0"/>
+      <name name="get" arity="0" since=""/>
       <fsummary>Return the process dictionary.</fsummary>
       <desc>
         <p>Returns the process dictionary as a list of
@@ -1930,7 +2019,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="get" arity="1"/>
+      <name name="get" arity="1" since=""/>
       <fsummary>Return a value from the process dictionary.</fsummary>
       <desc>
         <p>Returns the value <c><anno>Val</anno></c> associated with
@@ -1946,7 +2035,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="get_cookie" arity="0"/>
+      <name name="get_cookie" arity="0" since=""/>
       <fsummary>Get the magic cookie of the local node.</fsummary>
       <desc>
         <p>Returns the magic cookie of the local node if the node is
@@ -1955,7 +2044,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="get_keys" arity="0"/>
+      <name name="get_keys" arity="0" since="OTP 18.0"/>
       <fsummary>Return a list of all keys from the process dictionary.
       </fsummary>
       <desc>
@@ -1971,7 +2060,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="get_keys" arity="1"/>
+      <name name="get_keys" arity="1" since=""/>
       <fsummary>Return a list of keys from the process dictionary.</fsummary>
       <desc>
         <p>Returns a list of keys that are associated with the value
@@ -1989,7 +2078,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="get_stacktrace" arity="0"/>
+      <name name="get_stacktrace" arity="0" since=""/>
       <fsummary>Get the call stack back-trace of the last exception.</fsummary>
       <type name="stack_item"/>
       <desc>
@@ -2054,7 +2143,7 @@ end</pre>
     </func>
 
     <func>
-      <name name="group_leader" arity="0"/>
+      <name name="group_leader" arity="0" since=""/>
       <fsummary>Get the group leader for the calling process.</fsummary>
       <desc>
         <p>Returns the process identifier of the group leader for the
@@ -2069,7 +2158,7 @@ end</pre>
     </func>
 
     <func>
-      <name name="group_leader" arity="2"/>
+      <name name="group_leader" arity="2" since=""/>
       <fsummary>Set the group leader for a process.</fsummary>
       <desc>
         <p>Sets the group leader of <c><anno>Pid</anno></c>
@@ -2090,7 +2179,7 @@ end</pre>
     </func>
 
     <func>
-      <name name="halt" arity="0"/>
+      <name name="halt" arity="0" since=""/>
       <fsummary>Halt the Erlang runtime system and indicate normal exit to
         the calling environment.</fsummary>
       <desc>
@@ -2103,7 +2192,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="halt" arity="1"/>
+      <name name="halt" arity="1" since=""/>
       <fsummary>Halt the Erlang runtime system.</fsummary>
       <desc>
         <p>The same as <seealso marker="#halt/2">
@@ -2117,7 +2206,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="halt" arity="2"/>
+      <name name="halt" arity="2" since="OTP R15B01"/>
       <fsummary>Halt the Erlang runtime system.</fsummary>
       <desc>
         <p><c><anno>Status</anno></c> must be a non-negative integer, a string,
@@ -2159,7 +2248,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="hd" arity="1"/>
+      <name name="hd" arity="1" since=""/>
       <fsummary>Head of a list.</fsummary>
       <desc>
         <p>Returns the head of <c><anno>List</anno></c>, that is,
@@ -2174,7 +2263,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="hibernate" arity="3"/>
+      <name name="hibernate" arity="3" since=""/>
       <fsummary>Hibernate a process until a message is sent to it.</fsummary>
       <desc>
         <p>Puts the calling process into a wait state where its memory
@@ -2215,7 +2304,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="insert_element" arity="3"/>
+      <name name="insert_element" arity="3" since="OTP R16B"/>
       <fsummary>Insert an element at index in a tuple.</fsummary>
       <type_desc variable="Index">1..tuple_size(<anno>Tuple1</anno>)
         + 1</type_desc>
@@ -2233,7 +2322,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="integer_to_binary" arity="1"/>
+      <name name="integer_to_binary" arity="1" since="OTP R16B"/>
       <fsummary>Text representation of an integer.</fsummary>
       <desc>
         <p>Returns a binary corresponding to the text
@@ -2245,7 +2334,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="integer_to_binary" arity="2"/>
+      <name name="integer_to_binary" arity="2" since="OTP R16B"/>
       <fsummary>Text representation of an integer.</fsummary>
       <desc>
         <p>Returns a binary corresponding to the text
@@ -2258,7 +2347,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="integer_to_list" arity="1"/>
+      <name name="integer_to_list" arity="1" since=""/>
       <fsummary>Text representation of an integer.</fsummary>
       <desc>
         <p>Returns a string corresponding to the text
@@ -2270,7 +2359,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="integer_to_list" arity="2"/>
+      <name name="integer_to_list" arity="2" since=""/>
       <fsummary>Text representation of an integer.</fsummary>
       <desc>
         <p>Returns a string corresponding to the text
@@ -2283,7 +2372,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="iolist_size" arity="1"/>
+      <name name="iolist_size" arity="1" since=""/>
       <fsummary>Size of an iolist.</fsummary>
       <desc>
         <p>Returns an integer, that is the size in bytes,
@@ -2296,7 +2385,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="iolist_to_binary" arity="1"/>
+      <name name="iolist_to_binary" arity="1" since=""/>
       <fsummary>Convert an iolist to a binary.</fsummary>
       <desc>
         <p>Returns a binary that is made from the integers and
@@ -2314,7 +2403,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="iolist_to_iovec" arity="1"/>
+      <name name="iolist_to_iovec" arity="1" since="OTP 20.1"/>
       <fsummary>Converts an iolist to a iovec.</fsummary>
       <desc>
         <p>Returns an iovec that is made from the integers and binaries in
@@ -2323,7 +2412,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_alive" arity="0"/>
+      <name name="is_alive" arity="0" since=""/>
       <fsummary>Check whether the local node is alive.</fsummary>
       <desc>
         <p>Returns <c>true</c> if the local node is alive (that is, if
@@ -2333,7 +2422,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_atom" arity="1"/>
+      <name name="is_atom" arity="1" since=""/>
       <fsummary>Check whether a term is an atom.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is an atom,
@@ -2343,7 +2432,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_binary" arity="1"/>
+      <name name="is_binary" arity="1" since=""/>
       <fsummary>Check whether a term is a binary.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a binary,
@@ -2354,7 +2443,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_bitstring" arity="1"/>
+      <name name="is_bitstring" arity="1" since=""/>
       <fsummary>Check whether a term is a bitstring.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a
@@ -2364,7 +2453,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_boolean" arity="1"/>
+      <name name="is_boolean" arity="1" since=""/>
       <fsummary>Check whether a term is a boolean.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is the
@@ -2375,7 +2464,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_builtin" arity="3"/>
+      <name name="is_builtin" arity="3" since=""/>
       <fsummary>Check if a function is a BIF implemented in C.</fsummary>
       <desc>
         <p>This BIF is useful for builders of cross-reference tools.</p>
@@ -2386,7 +2475,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_float" arity="1"/>
+      <name name="is_float" arity="1" since=""/>
       <fsummary>Check whether a term is a float.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a floating point
@@ -2396,7 +2485,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_function" arity="1"/>
+      <name name="is_function" arity="1" since=""/>
       <fsummary>Check whether a term is a fun.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a fun, otherwise
@@ -2406,7 +2495,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_function" arity="2"/>
+      <name name="is_function" arity="2" since=""/>
       <fsummary>Check whether a term is a fun with a specified given arity.
       </fsummary>
       <desc>
@@ -2418,7 +2507,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_integer" arity="1"/>
+      <name name="is_integer" arity="1" since=""/>
       <fsummary>Check whether a term is an integer.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is an integer,
@@ -2428,7 +2517,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_list" arity="1"/>
+      <name name="is_list" arity="1" since=""/>
       <fsummary>Check whether a term is a list.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a list with
@@ -2438,7 +2527,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_map" arity="1"/>
+      <name name="is_map" arity="1" since="OTP 17.0"/>
       <fsummary>Check whether a term is a map.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a map,
@@ -2448,7 +2537,7 @@ os_prompt%</pre>
     </func>
 
     <func>
-      <name name="is_map_key" arity="2"/>
+      <name name="is_map_key" arity="2" since="OTP 21.0"/>
       <fsummary></fsummary>
       <desc>
         <p>Returns <c>true</c> if map <c><anno>Map</anno></c> contains
@@ -2464,11 +2553,12 @@ os_prompt%</pre>
 true
 > is_map_key(value,Map).
 false</code>
+        <p>Allowed in guard tests.</p>
       </desc>
     </func>
 
     <func>
-      <name name="is_number" arity="1"/>
+      <name name="is_number" arity="1" since=""/>
       <fsummary>Check whether a term is a number.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is an integer or a
@@ -2478,7 +2568,7 @@ false</code>
     </func>
 
     <func>
-      <name name="is_pid" arity="1"/>
+      <name name="is_pid" arity="1" since=""/>
       <fsummary>Check whether a term is a process identifier.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a process
@@ -2488,7 +2578,7 @@ false</code>
     </func>
 
     <func>
-      <name name="is_port" arity="1"/>
+      <name name="is_port" arity="1" since=""/>
       <fsummary>Check whether a term is a port.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a port identifier,
@@ -2498,7 +2588,7 @@ false</code>
     </func>
 
     <func>
-      <name name="is_process_alive" arity="1"/>
+      <name name="is_process_alive" arity="1" since=""/>
       <fsummary>Check whether a process is alive.</fsummary>
       <desc>
         <p><c><anno>Pid</anno></c> must refer to a process at the local
@@ -2510,7 +2600,7 @@ false</code>
     </func>
 
     <func>
-      <name name="is_record" arity="2"/>
+      <name name="is_record" arity="2" since=""/>
       <fsummary>Check whether a term appears to be a record.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a tuple and its
@@ -2531,7 +2621,7 @@ false</code>
     </func>
 
     <func>
-      <name name="is_record" arity="3"/>
+      <name name="is_record" arity="3" since=""/>
       <fsummary>Check whether a term appears to be a record.</fsummary>
       <desc>
         <p><c><anno>RecordTag</anno></c> must be an atom.</p>
@@ -2550,7 +2640,7 @@ false</code>
     </func>
 
     <func>
-      <name name="is_reference" arity="1"/>
+      <name name="is_reference" arity="1" since=""/>
       <fsummary>Check whether a term is a reference.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a reference,
@@ -2560,7 +2650,7 @@ false</code>
     </func>
 
     <func>
-      <name name="is_tuple" arity="1"/>
+      <name name="is_tuple" arity="1" since=""/>
       <fsummary>Check whether a term is a tuple.</fsummary>
       <desc>
         <p>Returns <c>true</c> if <c><anno>Term</anno></c> is a tuple,
@@ -2570,7 +2660,7 @@ false</code>
     </func>
 
     <func>
-      <name name="length" arity="1"/>
+      <name name="length" arity="1" since=""/>
       <fsummary>Length of a list.</fsummary>
       <desc>
         <p>Returns the length of <c><anno>List</anno></c>, for example:</p>
@@ -2582,7 +2672,7 @@ false</code>
     </func>
 
     <func>
-      <name name="link" arity="1"/>
+      <name name="link" arity="1" since=""/>
       <fsummary>Create a link to another process (or port).</fsummary>
       <desc>
         <p>Creates a link between the calling process and another
@@ -2609,7 +2699,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_atom" arity="1"/>
+      <name name="list_to_atom" arity="1" since=""/>
       <fsummary>Convert from text representation to an atom.</fsummary>
       <desc>
         <p>Returns the atom whose text representation is
@@ -2629,7 +2719,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_binary" arity="1"/>
+      <name name="list_to_binary" arity="1" since=""/>
       <fsummary>Convert a list to a binary.</fsummary>
       <desc>
         <p>Returns a binary that is made from the integers and
@@ -2647,7 +2737,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_bitstring" arity="1"/>
+      <name name="list_to_bitstring" arity="1" since=""/>
       <fsummary>Convert a list to a bitstring.</fsummary>
       <type name="bitstring_list"/>
       <desc>
@@ -2668,7 +2758,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_existing_atom" arity="1"/>
+      <name name="list_to_existing_atom" arity="1" since=""/>
       <fsummary>Convert from text representation to an atom.</fsummary>
       <desc>
         <p>Returns the atom whose text representation is
@@ -2689,7 +2779,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_float" arity="1"/>
+      <name name="list_to_float" arity="1" since=""/>
       <fsummary>Convert from text representation to a float.</fsummary>
       <desc>
         <p>Returns the float whose text representation is
@@ -2703,7 +2793,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_integer" arity="1"/>
+      <name name="list_to_integer" arity="1" since=""/>
       <fsummary>Convert from text representation to an integer.</fsummary>
       <desc>
         <p>Returns an integer whose text representation is
@@ -2717,7 +2807,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_integer" arity="2"/>
+      <name name="list_to_integer" arity="2" since=""/>
       <fsummary>Convert from text representation to an integer.</fsummary>
       <desc>
         <p>Returns an integer whose text representation in base
@@ -2732,7 +2822,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_pid" arity="1"/>
+      <name name="list_to_pid" arity="1" since=""/>
       <fsummary>Convert from text representation to a pid.</fsummary>
       <desc>
         <p>Returns a process identifier whose text representation is a 
@@ -2750,7 +2840,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_port" arity="1"/>
+      <name name="list_to_port" arity="1" since="OTP 20.0"/>
       <fsummary>Convert from text representation to a port.</fsummary>
       <desc>
         <p>Returns a port identifier whose text representation is a
@@ -2768,7 +2858,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_ref" arity="1"/>
+      <name name="list_to_ref" arity="1" since="OTP 20.0"/>
       <fsummary>Convert from text representation to a ref.</fsummary>
       <desc>
         <p>Returns a reference whose text representation is a
@@ -2786,7 +2876,7 @@ false</code>
     </func>
 
     <func>
-      <name name="list_to_tuple" arity="1"/>
+      <name name="list_to_tuple" arity="1" since=""/>
       <fsummary>Convert a list to a tuple.</fsummary>
       <desc>
         <p>Returns a tuple corresponding to <c><anno>List</anno></c>,
@@ -2799,7 +2889,7 @@ false</code>
     </func>
 
     <func>
-      <name name="load_module" arity="2"/>
+      <name name="load_module" arity="2" since=""/>
       <fsummary>Load object code for a module.</fsummary>
       <desc>
         <p>If <c><anno>Binary</anno></c> contains the object code for module
@@ -2832,7 +2922,7 @@ false</code>
     </func>
 
     <func>
-      <name name="load_nif" arity="2"/>
+      <name name="load_nif" arity="2" since=""/>
       <fsummary>Load NIF library.</fsummary>
       <desc>
         <p>Loads and links a dynamic library containing native
@@ -2885,7 +2975,7 @@ false</code>
     </func>
 
     <func>
-      <name name="loaded" arity="0"/>
+      <name name="loaded" arity="0" since=""/>
       <fsummary>List all loaded modules.</fsummary>
       <desc>
         <p>Returns a list of all loaded Erlang modules (current and
@@ -2896,7 +2986,7 @@ false</code>
     </func>
 
     <func>
-      <name name="localtime" arity="0"/>
+      <name name="localtime" arity="0" since=""/>
       <fsummary>Current local date and time.</fsummary>
       <desc>
         <p>Returns the current local date and time,
@@ -2911,7 +3001,7 @@ false</code>
     </func>
 
     <func>
-      <name name="localtime_to_universaltime" arity="1"/>
+      <name name="localtime_to_universaltime" arity="1" since=""/>
       <fsummary>Convert from local to Universal Time Coordinated (UTC) date
         and time.</fsummary>
       <desc>
@@ -2928,7 +3018,7 @@ false</code>
     </func>
 
     <func>
-      <name name="localtime_to_universaltime" arity="2"/>
+      <name name="localtime_to_universaltime" arity="2" since=""/>
       <fsummary>Convert from local to Universal Time Coordinated (UTC) date
         and time.</fsummary>
       <desc>
@@ -2954,7 +3044,7 @@ false</code>
     </func>
 
     <func>
-      <name name="make_ref" arity="0"/>
+      <name name="make_ref" arity="0" since=""/>
       <fsummary>Return a unique reference.</fsummary>
       <desc>
         <p>Returns a
@@ -2971,7 +3061,7 @@ false</code>
     </func>
 
     <func>
-      <name name="make_tuple" arity="2"/>
+      <name name="make_tuple" arity="2" since=""/>
       <fsummary>Create a new tuple of a specified arity.</fsummary>
       <desc>
         <p>Creates a new tuple of the specified <c><anno>Arity</anno></c>, where
@@ -2983,7 +3073,7 @@ false</code>
     </func>
 
     <func>
-      <name name="make_tuple" arity="3"/>
+      <name name="make_tuple" arity="3" since=""/>
       <fsummary>Create a new tuple with specifed arity and contents.</fsummary>
       <desc>
         <p>Creates a tuple of size <c><anno>Arity</anno></c>, where each element
@@ -3001,7 +3091,7 @@ false</code>
     </func>
 
     <func>
-      <name name="map_get" arity="2" />
+      <name name="map_get" arity="2"  since="OTP 21.0"/>
       <fsummary>Extract a value from a map</fsummary>
       <desc>
         <p>Returns value <c><anno>Value</anno></c> associated with
@@ -3016,11 +3106,12 @@ false</code>
   Map = #{42 => value_two,1337 => "value one","a" => 1},
   map_get(Key,Map).
 "value one"</code>
+        <p>Allowed in guard tests.</p>
       </desc>
     </func>
 
     <func>
-      <name name="map_size" arity="1"/>
+      <name name="map_size" arity="1" since="OTP 17.0"/>
       <fsummary>Return the size of a map.</fsummary>
       <desc>
         <p>Returns an integer, which is the number of key-value pairs
@@ -3033,7 +3124,7 @@ false</code>
     </func>
 
     <func>
-      <name name="match_spec_test" arity="3"/>
+      <name name="match_spec_test" arity="3" since="OTP 19.0"/>
       <fsummary>Test that a match specification works.</fsummary>
       <desc>
         <p>Tests a match specification used in calls to
@@ -3071,7 +3162,7 @@ false</code>
     </func>
 
     <func>
-      <name name="max" arity="2"/>
+      <name name="max" arity="2" since=""/>
       <fsummary>Return the largest of two terms.</fsummary>
       <desc>
         <p>Returns the largest of <c><anno>Term1</anno></c> and
@@ -3081,7 +3172,7 @@ false</code>
     </func>
 
     <func>
-      <name name="md5" arity="1"/>
+      <name name="md5" arity="1" since=""/>
       <fsummary>Compute an MD5 message digest.</fsummary>
       <desc>
         <p>Computes an MD5 message digest from <c><anno>Data</anno></c>, where
@@ -3099,7 +3190,7 @@ false</code>
     </func>
 
     <func>
-      <name name="md5_final" arity="1"/>
+      <name name="md5_final" arity="1" since=""/>
       <fsummary>Finish the update of an MD5 context and return the computed
         MD5 message digest.</fsummary>
       <desc>
@@ -3109,7 +3200,7 @@ false</code>
     </func>
 
     <func>
-      <name name="md5_init" arity="0"/>
+      <name name="md5_init" arity="0" since=""/>
       <fsummary>Create an MD5 context.</fsummary>
       <desc>
         <p>Creates an MD5 context, to be used in the following calls to
@@ -3118,7 +3209,7 @@ false</code>
     </func>
 
     <func>
-      <name name="md5_update" arity="2"/>
+      <name name="md5_update" arity="2" since=""/>
       <fsummary>Update an MD5 context with data and return a new context.
       </fsummary>
       <desc>
@@ -3129,7 +3220,7 @@ false</code>
     </func>
 
     <func>
-      <name name="memory" arity="0"/>
+      <name name="memory" arity="0" since=""/>
       <fsummary>Information about dynamically allocated memory.</fsummary>
       <type name="memory_type"/>
       <desc>
@@ -3273,8 +3364,8 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="memory" arity="1" clause_i="1"/>
-      <name name="memory" arity="1" clause_i="2"/>
+      <name name="memory" arity="1" clause_i="1" since=""/>
+      <name name="memory" arity="1" clause_i="2" since=""/>
       <fsummary>Information about dynamically allocated memory.</fsummary>
       <type name="memory_type"/>
       <desc>
@@ -3313,7 +3404,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="min" arity="2"/>
+      <name name="min" arity="2" since=""/>
       <fsummary>Return the smallest of two terms.</fsummary>
       <desc>
         <p>Returns the smallest of <c><anno>Term1</anno></c> and
@@ -3323,7 +3414,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="module_loaded" arity="1"/>
+      <name name="module_loaded" arity="1" since=""/>
       <fsummary>Check if a module is loaded.</fsummary>
       <desc>
         <p>Returns <c>true</c> if the module <c><anno>Module</anno></c>
@@ -3338,9 +3429,9 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="monitor" arity="2" clause_i="1"/>
-      <name name="monitor" arity="2" clause_i="2"/>
-      <name name="monitor" arity="2" clause_i="3"/>
+      <name name="monitor" arity="2" clause_i="1" since=""/>
+      <name name="monitor" arity="2" clause_i="2" since="OTP 19.0"/>
+      <name name="monitor" arity="2" clause_i="3" since="OTP 18.0"/>
       <fsummary>Start monitoring.</fsummary>
       <type name="registered_name"/>
       <type name="registered_process_identifier"/>
@@ -3512,7 +3603,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="monitor_node" arity="2"/>
+      <name name="monitor_node" arity="2" since=""/>
       <fsummary>Monitor the status of a node.</fsummary>
       <desc>
         <p>Monitor the status of the node <c><anno>Node</anno></c>.
@@ -3536,7 +3627,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="monitor_node" arity="3"/>
+      <name name="monitor_node" arity="3" since=""/>
       <fsummary>Monitor the status of a node.</fsummary>
       <desc>
         <p>Behaves as
@@ -3562,7 +3653,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="monotonic_time" arity="0"/>
+      <name name="monotonic_time" arity="0" since="OTP 18.0"/>
       <fsummary>Current Erlang monotonic time.</fsummary>
       <desc>
         <p>Returns the current
@@ -3596,7 +3687,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="monotonic_time" arity="1"/>
+      <name name="monotonic_time" arity="1" since="OTP 18.0"/>
       <fsummary>Current Erlang monotonic time.</fsummary>
       <desc>
         <p>Returns the current
@@ -3614,7 +3705,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="nif_error" arity="1"/>
+      <name name="nif_error" arity="1" since="OTP R14B"/>
       <fsummary>Stop execution with a specified reason.</fsummary>
       <desc>
         <p>Works exactly like
@@ -3627,7 +3718,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="nif_error" arity="2"/>
+      <name name="nif_error" arity="2" since="OTP R14B"/>
       <fsummary>Stop execution with a specified reason.</fsummary>
       <desc>
         <p>Works exactly like
@@ -3640,7 +3731,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="node" arity="0"/>
+      <name name="node" arity="0" since=""/>
       <fsummary>Name of the local node.</fsummary>
       <desc>
         <p>Returns the name of the local node. If the node is not alive,
@@ -3650,7 +3741,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="node" arity="1"/>
+      <name name="node" arity="1" since=""/>
       <fsummary>At which node a pid, port, or reference originates.</fsummary>
       <desc>
         <p>Returns the node where <c><anno>Arg</anno></c> originates.
@@ -3663,7 +3754,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="nodes" arity="0"/>
+      <name name="nodes" arity="0" since=""/>
       <fsummary>All visible nodes in the system.</fsummary>
       <desc>
         <p>Returns a list of all visible nodes in the system, except
@@ -3672,7 +3763,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="nodes" arity="1"/>
+      <name name="nodes" arity="1" since=""/>
       <fsummary>All nodes of a certain type in the system.</fsummary>
       <desc>
         <p>Returns a list of nodes according to the argument specified.
@@ -3715,7 +3806,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="now" arity="0"/>
+      <name name="now" arity="0" since=""/>
       <fsummary>Elapsed time since 00:00 GMT.</fsummary>
       <type name="timestamp"/>
       <desc>
@@ -3744,7 +3835,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="open_port" arity="2"/>
+      <name name="open_port" arity="2" since=""/>
       <fsummary>Open a port.</fsummary>
       <desc>
         <p>Returns a port identifier as the result of opening a
@@ -4085,7 +4176,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="phash" arity="2"/>
+      <name name="phash" arity="2" since=""/>
       <fsummary>Portable hash function.</fsummary>
       <type_desc variable="Range">Range = 1..2^32, Hash = 1..Range</type_desc>
       <desc>
@@ -4100,8 +4191,8 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="phash2" arity="1"/>
-      <name name="phash2" arity="2"/>
+      <name name="phash2" arity="1" since=""/>
+      <name name="phash2" arity="2" since=""/>
       <fsummary>Portable hash function.</fsummary>
       <type_desc variable="Range">1..2^32</type_desc>
       <type_desc variable="Hash">0..Range-1</type_desc>
@@ -4125,7 +4216,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="pid_to_list" arity="1"/>
+      <name name="pid_to_list" arity="1" since=""/>
       <fsummary>Text representation of a pid.</fsummary>
       <desc>
         <p>Returns a string corresponding to the text
@@ -4134,7 +4225,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_call" arity="3"/>
+      <name name="port_call" arity="3" since=""/>
       <fsummary>Perform a synchronous call to a port with term data.</fsummary>
       <desc>
         <p>Performs a synchronous call to a port. The meaning of
@@ -4170,16 +4261,23 @@ RealSystem = system + MissedSystem</code>
           </item>
           <tag><c>badarg</c></tag>
           <item>
-            If the port driver so decides for any reason (probably
+            <p>If the port driver so decides for any reason (probably
             something wrong with <c><anno>Operation</anno></c>
-            or <c><anno>Data</anno></c>).
+            or <c><anno>Data</anno></c>).</p>
+	    <warning>
+	      <p>Do not call <c>port_call</c> with an unknown
+	      <c><anno>Port</anno></c> identifier and expect <c>badarg</c>
+	      exception. Any undefined behavior is possible (including node
+	      crash) depending on how the port driver interprets the supplied
+	      arguments.</p>
+	    </warning>
           </item>
         </taglist>
       </desc>
     </func>
 
     <func>
-      <name name="port_close" arity="1"/>
+      <name name="port_close" arity="1" since=""/>
       <fsummary>Close an open port.</fsummary>
       <desc>
         <p>Closes an open port. Roughly the same as <c><anno>Port</anno> !
@@ -4219,7 +4317,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_command" arity="2"/>
+      <name name="port_command" arity="2" since=""/>
       <fsummary>Send data to a port.</fsummary>
       <desc>
         <p>Sends data to a port. Same as
@@ -4262,11 +4360,16 @@ RealSystem = system + MissedSystem</code>
             <p>If <c><anno>Data</anno></c> is an invalid I/O list.</p>
           </item>
         </taglist>
+	<warning>
+	  <p>Do not send data to an unknown port. Any undefined behavior is
+	  possible (including node crash) depending on how the port driver
+	  interprets the data.</p>
+	</warning>
       </desc>
     </func>
 
     <func>
-      <name name="port_command" arity="3"/>
+      <name name="port_command" arity="3" since=""/>
       <fsummary>Send data to a port.</fsummary>
       <desc>
         <p>Sends data to a port. <c>port_command(Port, Data, [])</c>
@@ -4321,11 +4424,16 @@ RealSystem = system + MissedSystem</code>
             a busy port.
           </item>
         </taglist>
+	<warning>
+	  <p>Do not send data to an unknown port. Any undefined behavior is
+	  possible (including node crash) depending on how the port driver
+	  interprets the data.</p>
+	</warning>
       </desc>
     </func>
 
     <func>
-      <name name="port_connect" arity="2"/>
+      <name name="port_connect" arity="2" since=""/>
       <fsummary>Set the owner of a port.</fsummary>
       <desc>
         <p>Sets the port owner (the connected port) to <c><anno>Pid</anno></c>.
@@ -4394,7 +4502,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_control" arity="3"/>
+      <name name="port_control" arity="3" since=""/>
       <fsummary>Perform a synchronous control operation on a port.</fsummary>
       <desc>
         <p>Performs a synchronous control operation on a port.
@@ -4425,13 +4533,20 @@ RealSystem = system + MissedSystem</code>
             If the port driver so decides for any reason (probably
             something wrong with <c><anno>Operation</anno></c> or
             <c><anno>Data</anno></c>).
+	    <warning>
+	      <p>Do not call <c>port_control/3</c> with an unknown
+	      <c><anno>Port</anno></c> identifier and expect <c>badarg</c>
+	      exception. Any undefined behavior is possible (including node
+	      crash) depending on how the port driver interprets the supplied
+	      arguments.</p>
+	    </warning>
           </item>
         </taglist>
       </desc>
     </func>
 
     <func>
-      <name name="port_info" arity="1"/>
+      <name name="port_info" arity="1" since=""/>
       <fsummary>Information about a port.</fsummary>
       <desc>
         <p>Returns a list containing tuples with information about
@@ -4462,7 +4577,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="1"/>
+      <name name="port_info" arity="2" clause_i="1" since=""/>
       <fsummary>Information about the connected process of a port.</fsummary>
       <desc>
         <p><c><anno>Pid</anno></c> is the process identifier of the process
@@ -4478,7 +4593,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="2"/>
+      <name name="port_info" arity="2" clause_i="2" since=""/>
       <fsummary>Information about the internal index of a port.</fsummary>
       <desc>
         <p><c><anno>Index</anno></c> is the internal index of the port. This
@@ -4494,7 +4609,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="3"/>
+      <name name="port_info" arity="2" clause_i="3" since=""/>
       <fsummary>Information about the input of a port.</fsummary>
       <desc>
         <p><c><anno>Bytes</anno></c> is the total number of bytes
@@ -4510,7 +4625,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="4"/>
+      <name name="port_info" arity="2" clause_i="4" since=""/>
       <fsummary>Information about the links of a port.</fsummary>
       <desc>
         <p><c><anno>Pids</anno></c> is a list of the process identifiers
@@ -4526,7 +4641,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="5"/>
+      <name name="port_info" arity="2" clause_i="5" since="OTP R16B"/>
       <fsummary>Information about the locking of a port.</fsummary>
       <desc>
         <p><c><anno>Locking</anno></c> is one of the following:</p>
@@ -4547,9 +4662,10 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="6"/>
+      <name name="port_info" arity="2" clause_i="6" since="OTP R16B"/>
       <fsummary>Information about the memory size of a port.</fsummary>
       <desc>
+        <marker id="port_info_memory"/>
         <p><c><anno>Bytes</anno></c> is the total number of
           bytes allocated for this port by the runtime system. The
           port itself can have allocated memory that is not
@@ -4565,7 +4681,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="7"/>
+      <name name="port_info" arity="2" clause_i="7" since="OTP R16B"/>
       <fsummary>Information about the monitors of a port.</fsummary>
       <desc>
         <p><c><anno>Monitors</anno></c> represent processes monitored by
@@ -4581,7 +4697,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="8"/>
+      <name name="port_info" arity="2" clause_i="8" since="OTP 19.0"/>
       <fsummary>Which processes are monitoring this port.</fsummary>
       <desc>
         <p>Returns list of pids that are monitoring given port at the
@@ -4597,7 +4713,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="9"/>
+      <name name="port_info" arity="2" clause_i="9" since=""/>
       <fsummary>Information about the name of a port.</fsummary>
       <desc>
         <p><c><anno>Name</anno></c> is the command name set by
@@ -4613,7 +4729,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="10"/>
+      <name name="port_info" arity="2" clause_i="10" since="OTP R16B"/>
       <fsummary>Information about the OS pid of a port.</fsummary>
       <desc>
         <p><c><anno>OsPid</anno></c> is the process identifier (or equivalent)
@@ -4632,7 +4748,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="11"/>
+      <name name="port_info" arity="2" clause_i="11" since=""/>
       <fsummary>Information about the output of a port.</fsummary>
       <desc>
         <p><c><anno>Bytes</anno></c> is the total number of bytes written
@@ -4651,7 +4767,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="12"/>
+      <name name="port_info" arity="2" clause_i="12" since="OTP R16B"/>
       <fsummary>Information about the parallelism hint of a port.</fsummary>
       <desc>
         <p><c><anno>Boolean</anno></c> corresponds to the port parallelism
@@ -4662,7 +4778,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="13"/>
+      <name name="port_info" arity="2" clause_i="13" since="OTP R16B"/>
       <fsummary>Information about the queue size of a port.</fsummary>
       <desc>
         <p><c><anno>Bytes</anno></c> is the total number
@@ -4679,7 +4795,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_info" arity="2" clause_i="14"/>
+      <name name="port_info" arity="2" clause_i="14" since=""/>
       <fsummary>Information about the registered name of a port.</fsummary>
       <desc>
         <p><c><anno>RegisteredName</anno></c> is the registered name of
@@ -4696,7 +4812,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="port_to_list" arity="1"/>
+      <name name="port_to_list" arity="1" since=""/>
       <fsummary>Text representation of a port identifier.</fsummary>
       <desc>
         <p>Returns a string corresponding to the text
@@ -4705,7 +4821,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="ports" arity="0"/>
+      <name name="ports" arity="0" since=""/>
       <fsummary>List all existing ports.</fsummary>
       <desc>
         <p>Returns a list of port identifiers corresponding to all the
@@ -4715,7 +4831,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="pre_loaded" arity="0"/>
+      <name name="pre_loaded" arity="0" since=""/>
       <fsummary>List all preloaded modules.</fsummary>
       <desc>
         <p>Returns a list of Erlang modules that are preloaded in
@@ -4726,7 +4842,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="process_display" arity="2"/>
+      <name name="process_display" arity="2" since=""/>
       <fsummary>Write information about a local process on standard error.
       </fsummary>
       <desc>
@@ -4740,7 +4856,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="process_flag" arity="2" clause_i="1"/>
+      <name name="process_flag" arity="2" clause_i="1" since=""/>
       <fsummary>Set process flag trap_exit for the calling process.</fsummary>
       <desc>
         <p>When <c>trap_exit</c> is set to <c>true</c>, exit signals
@@ -4757,7 +4873,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="process_flag" arity="2" clause_i="2"/>
+      <name name="process_flag" arity="2" clause_i="2" since=""/>
       <fsummary>Set process flag error_handler for the calling process.
       </fsummary>
       <desc>
@@ -4772,7 +4888,7 @@ RealSystem = system + MissedSystem</code>
 
     <func>
       <name name="process_flag" arity="2" clause_i="3"
-	    anchor="process_flag_min_heap_size"/>
+	    anchor="process_flag_min_heap_size" since=""/>
       <fsummary>Set process flag min_heap_size for the calling process.
       </fsummary>
       <desc>
@@ -4782,7 +4898,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="process_flag" arity="2" clause_i="4"/>
+      <name name="process_flag" arity="2" clause_i="4" since="OTP R13B04"/>
       <fsummary>Set process flag min_bin_vheap_size for the calling process.
       </fsummary>
       <desc>
@@ -4794,7 +4910,7 @@ RealSystem = system + MissedSystem</code>
 
     <func>
       <name name="process_flag" arity="2" clause_i="5"
-	    anchor="process_flag_max_heap_size"/>
+	    anchor="process_flag_max_heap_size" since="OTP 19.0"/>
       <fsummary>Set process flag max_heap_size for the calling process.
       </fsummary>
       <type name="max_heap_size"/>
@@ -4868,7 +4984,7 @@ RealSystem = system + MissedSystem</code>
 
     <func>
       <name name="process_flag" arity="2" clause_i="6"
-	    anchor="process_flag_message_queue_data"/>
+	    anchor="process_flag_message_queue_data" since="OTP 19.0"/>
       <fsummary>Set process flag message_queue_data for the calling process.
       </fsummary>
       <type name="message_queue_data"/>
@@ -4910,7 +5026,7 @@ RealSystem = system + MissedSystem</code>
 
     <func>
       <name name="process_flag" arity="2" clause_i="7"
-	    anchor="process_flag_priority"/>
+	    anchor="process_flag_priority" since=""/>
       <fsummary>Set process flag priority for the calling process.</fsummary>
       <type name="priority_level"/>
       <desc>
@@ -4982,7 +5098,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="process_flag" arity="2" clause_i="8"/>
+      <name name="process_flag" arity="2" clause_i="8" since=""/>
       <fsummary>Set process flag save_calls for the calling process.</fsummary>
       <desc>
         <p><c><anno>N</anno></c> must be an integer in the interval 0..10000.
@@ -5013,7 +5129,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="process_flag" arity="2" clause_i="9"/>
+      <name name="process_flag" arity="2" clause_i="9" since=""/>
       <fsummary>Set process flag sensitive for the calling process.</fsummary>
       <desc>
         <p>Sets or clears flag <c>sensitive</c> for the current process.
@@ -5047,7 +5163,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="process_flag" arity="3"/>
+      <name name="process_flag" arity="3" since=""/>
       <fsummary>Set process flags for a process.</fsummary>
       <desc>
         <p>Sets certain flags for the process <c><anno>Pid</anno></c>,
@@ -5062,7 +5178,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="process_info" arity="1"/>
+      <name name="process_info" arity="1" since=""/>
       <fsummary>Information about a process.</fsummary>
       <type name="process_info_result_item"/>
       <type name="priority_level"/>
@@ -5113,8 +5229,8 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="process_info" arity="2" clause_i="1"/>
-      <name name="process_info" arity="2" clause_i="2"/>
+      <name name="process_info" arity="2" clause_i="1" since=""/>
+      <name name="process_info" arity="2" clause_i="2" since=""/>
       <fsummary>Information about a process.</fsummary>
       <type name="process_info_item"/>
       <type name="process_info_result_item"/>
@@ -5182,11 +5298,13 @@ RealSystem = system + MissedSystem</code>
               changed or removed without prior notice.</p>
           </item>
           <tag><c>{current_function, {<anno>Module</anno>,
-            <anno>Function</anno>, Arity}}</c></tag>
+            <anno>Function</anno>, Arity} | undefined}</c></tag>
           <item>
             <p><c><anno>Module</anno></c>, <c><anno>Function</anno></c>,
               <c><anno>Arity</anno></c> is
-              the current function call of the process.</p>
+              the current function call of the process. The value
+              <c>undefined</c> can be returned if the process is
+              currently executing native compiled code.</p>
           </item>
           <tag><c>{current_location, {<anno>Module</anno>,
             <anno>Function</anno>, <anno>Arity</anno>,
@@ -5272,6 +5390,7 @@ RealSystem = system + MissedSystem</code>
           </item>
           <tag><c>{memory, <anno>Size</anno>}</c></tag>
           <item>
+            <marker id="process_info_memory"/>
             <p><c><anno>Size</anno></c> is the size in bytes of the process.
               This includes call stack, heap, and internal structures.</p>
           </item>
@@ -5447,7 +5566,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="processes" arity="0"/>
+      <name name="processes" arity="0" since=""/>
       <fsummary>All processes.</fsummary>
       <desc>
         <p>Returns a list of process identifiers corresponding to
@@ -5464,7 +5583,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="purge_module" arity="1"/>
+      <name name="purge_module" arity="1" since=""/>
       <fsummary>Remove old code for a module.</fsummary>
       <desc>
         <p>Removes old code for <c><anno>Module</anno></c>.
@@ -5489,7 +5608,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="put" arity="2"/>
+      <name name="put" arity="2" since=""/>
       <fsummary>Add a new value to the process dictionary.</fsummary>
       <desc>
         <p>Adds a new <c><anno>Key</anno></c> to the process dictionary,
@@ -5511,7 +5630,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="raise" arity="3"/>
+      <name name="raise" arity="3" since=""/>
       <fsummary>Stop execution with an exception of specified class, reason,
         and call stack backtrace.</fsummary>
       <type name="raise_stacktrace"/>
@@ -5550,7 +5669,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="read_timer" arity="1"/>
+      <name name="read_timer" arity="1" since=""/>
       <fsummary>Read the state of a timer.</fsummary>
       <desc>
         <p>Reads the state of a timer. The same as calling
@@ -5560,7 +5679,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="read_timer" arity="2"/>
+      <name name="read_timer" arity="2" since="OTP 18.0"/>
       <fsummary>Read the state of a timer.</fsummary>
       <desc>
         <p>Reads the state of a timer that has been created by either
@@ -5616,7 +5735,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="ref_to_list" arity="1"/>
+      <name name="ref_to_list" arity="1" since=""/>
       <fsummary>Text representation of a reference.</fsummary>
       <desc>
         <p>Returns a string corresponding to the text
@@ -5629,7 +5748,7 @@ RealSystem = system + MissedSystem</code>
     </func>
 
     <func>
-      <name name="register" arity="2"/>
+      <name name="register" arity="2" since=""/>
       <fsummary>Register a name for a pid (or port).</fsummary>
       <desc>
         <p>Associates the name <c><anno>RegName</anno></c> with a process
@@ -5658,7 +5777,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="registered" arity="0"/>
+      <name name="registered" arity="0" since=""/>
       <fsummary>All registered names.</fsummary>
       <desc>
         <p>Returns a list of names that have been registered using
@@ -5671,7 +5790,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="resume_process" arity="1"/>
+      <name name="resume_process" arity="1" since=""/>
       <fsummary>Resume a suspended process.</fsummary>
       <desc>
         <p>Decreases the suspend count on the process identified by
@@ -5712,7 +5831,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="round" arity="1"/>
+      <name name="round" arity="1" since=""/>
       <fsummary>Return an integer by rounding a number.</fsummary>
       <desc>
         <p>Returns an integer by rounding <c><anno>Number</anno></c>,
@@ -5725,7 +5844,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="self" arity="0"/>
+      <name name="self" arity="0" since=""/>
       <fsummary>Return pid of the calling process.</fsummary>
       <desc>
         <p>Returns the process identifier of the calling process, for
@@ -5738,7 +5857,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="send" arity="2"/>
+      <name name="send" arity="2" since=""/>
       <fsummary>Send a message.</fsummary>
       <type name="dst"/>
       <desc>
@@ -5758,7 +5877,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="send" arity="3"/>
+      <name name="send" arity="3" since=""/>
       <fsummary>Send a message conditionally.</fsummary>
       <type name="dst"/>
       <desc>
@@ -5790,7 +5909,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="send_after" arity="3"/>
+      <name name="send_after" arity="3" since=""/>
       <fsummary>Start a timer.</fsummary>
       <desc>
         <p>Starts a timer. The same as calling
@@ -5801,7 +5920,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="send_after" arity="4"/>
+      <name name="send_after" arity="4" since="OTP 18.0"/>
       <fsummary>Start a timer.</fsummary>
       <desc>
         <p>Starts a timer. When the timer expires, the message
@@ -5814,7 +5933,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="send_nosuspend" arity="2"/>
+      <name name="send_nosuspend" arity="2" since=""/>
       <fsummary>Try to send a message without ever blocking.</fsummary>
       <type name="dst"/>
       <desc>
@@ -5864,7 +5983,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="send_nosuspend" arity="3"/>
+      <name name="send_nosuspend" arity="3" since=""/>
       <fsummary>Try to send a message without ever blocking.</fsummary>
       <type name="dst"/>
       <desc>
@@ -5897,7 +6016,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="set_cookie" arity="2"/>
+      <name name="set_cookie" arity="2" since=""/>
       <fsummary>Set the magic cookie of a node.</fsummary>
       <desc>
         <p>Sets the magic cookie of <c><anno>Node</anno></c> to the atom
@@ -5914,7 +6033,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="setelement" arity="3"/>
+      <name name="setelement" arity="3" since=""/>
       <fsummary>Set the Nth element of a tuple.</fsummary>
       <type_desc variable="Index">1..tuple_size(<anno>Tuple1</anno></type_desc>
       <desc>
@@ -5931,7 +6050,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="size" arity="1"/>
+      <name name="size" arity="1" since=""/>
       <fsummary>Size of a tuple or binary.</fsummary>
       <desc>
         <p>Returns the number of elements in a tuple or the number of
@@ -5954,7 +6073,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn" arity="1"/>
+      <name name="spawn" arity="1" since=""/>
       <fsummary>Create a new process with a fun as entry point.</fsummary>
       <desc>
         <p>Returns the process identifier of a new process started by the
@@ -5965,7 +6084,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn" arity="2"/>
+      <name name="spawn" arity="2" since=""/>
       <fsummary>Create a new process with a fun as entry point on a specified
         node.</fsummary>
       <desc>
@@ -5979,7 +6098,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn" arity="3"/>
+      <name name="spawn" arity="3" since=""/>
       <fsummary>Create a new process with a function as entry point.</fsummary>
       <desc>
         <p>Returns the process identifier of a new process started by
@@ -6004,7 +6123,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn" arity="4"/>
+      <name name="spawn" arity="4" since=""/>
       <fsummary>Create a new process with a function as entry point on a
         specified node.</fsummary>
       <desc>
@@ -6019,7 +6138,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_link" arity="1"/>
+      <name name="spawn_link" arity="1" since=""/>
       <fsummary>Create and link to a new process with a fun as entry point.
       </fsummary>
       <desc>
@@ -6033,7 +6152,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_link" arity="2"/>
+      <name name="spawn_link" arity="2" since=""/>
       <fsummary>Create and link to a new process with a fun as entry point on
         a specified node.</fsummary>
       <desc>
@@ -6050,7 +6169,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_link" arity="3"/>
+      <name name="spawn_link" arity="3" since=""/>
       <fsummary>Create and link to a new process with a function as entry point.
       </fsummary>
       <desc>
@@ -6064,7 +6183,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_link" arity="4"/>
+      <name name="spawn_link" arity="4" since=""/>
       <fsummary>Create and link to a new process with a function as entry point
         on a specified node.</fsummary>
       <desc>
@@ -6082,7 +6201,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_monitor" arity="1"/>
+      <name name="spawn_monitor" arity="1" since=""/>
       <fsummary>Create and monitor a new process with a fun as entry point.
       </fsummary>
       <desc>
@@ -6096,7 +6215,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_monitor" arity="3"/>
+      <name name="spawn_monitor" arity="3" since=""/>
       <fsummary>Create and monitor a new process with a function as entry point.
       </fsummary>
       <desc>
@@ -6110,7 +6229,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_opt" arity="2"/>
+      <name name="spawn_opt" arity="2" since=""/>
       <fsummary>Create a new process with a fun as entry point.</fsummary>
       <type name="priority_level"/>
       <type name="max_heap_size"/>
@@ -6128,7 +6247,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_opt" arity="3"/>
+      <name name="spawn_opt" arity="3" since=""/>
       <fsummary>Create a new process with a fun as entry point on a specified
         node.</fsummary>
       <type name="priority_level"/>
@@ -6146,7 +6265,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_opt" arity="4"/>
+      <name name="spawn_opt" arity="4" since=""/>
       <fsummary>Create a new process with a function as entry point.</fsummary>
       <type name="priority_level"/>
       <type name="max_heap_size"/>
@@ -6282,7 +6401,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="spawn_opt" arity="5"/>
+      <name name="spawn_opt" arity="5" since=""/>
       <fsummary>Create a new process with a function as entry point on a
         specified node.</fsummary>
       <type name="priority_level"/>
@@ -6305,7 +6424,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="split_binary" arity="2"/>
+      <name name="split_binary" arity="2" since=""/>
       <fsummary>Split a binary into two.</fsummary>
       <type_desc variable="Pos">0..byte_size(Bin)</type_desc>
       <desc>
@@ -6329,7 +6448,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="start_timer" arity="3"/>
+      <name name="start_timer" arity="3" since=""/>
       <fsummary>Start a timer.</fsummary>
       <desc>
         <p>Starts a timer. The same as calling
@@ -6340,7 +6459,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="start_timer" arity="4"/>
+      <name name="start_timer" arity="4" since="OTP 18.0"/>
       <fsummary>Start a timer.</fsummary>
       <desc>
         <p>Starts a timer. When the timer expires, the message
@@ -6399,7 +6518,7 @@ true</pre>
 
     <func>
       <name name="statistics" arity="1" clause_i="1"
-	    anchor="statistics_active_tasks"/>
+	    anchor="statistics_active_tasks" since="OTP 18.3"/>
       <fsummary>Information about active processes and ports.</fsummary>
       <desc>
         <p>Returns the same as
@@ -6414,7 +6533,7 @@ true</pre>
 
     <func>
       <name name="statistics" arity="1" clause_i="2"
-	    anchor="statistics_active_tasks_all"/>
+	    anchor="statistics_active_tasks_all" since="OTP 20.0"/>
       <fsummary>Information about active processes and ports.</fsummary>
       <desc>
         <p>Returns a list where each element represents the amount
@@ -6455,7 +6574,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="statistics" arity="1" clause_i="3"/>
+      <name name="statistics" arity="1" clause_i="3" since=""/>
       <fsummary>Information about context switches.</fsummary>
       <desc>
         <p>Returns the total number of context switches since the
@@ -6465,7 +6584,7 @@ true</pre>
 
     <func>
       <name name="statistics" arity="1" clause_i="4"
-	    anchor="statistics_exact_reductions"/>
+	    anchor="statistics_exact_reductions" since=""/>
       <fsummary>Information about exact reductions.</fsummary>
       <desc>
         <p>Returns the number of exact reductions.</p>
@@ -6479,7 +6598,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="statistics" arity="1" clause_i="5"/>
+      <name name="statistics" arity="1" clause_i="5" since=""/>
       <fsummary>Information about garbage collection.</fsummary>
       <desc>
         <p>Returns information about garbage collection, for example:</p>
@@ -6491,7 +6610,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="statistics" arity="1" clause_i="6"/>
+      <name name="statistics" arity="1" clause_i="6" since=""/>
       <fsummary>Information about I/O.</fsummary>
       <desc>
         <p>Returns <c><anno>Input</anno></c>,
@@ -6503,7 +6622,7 @@ true</pre>
 
     <func>
       <name name="statistics" arity="1" clause_i="7"
-	    anchor="statistics_microstate_accounting"/>
+	    anchor="statistics_microstate_accounting" since="OTP 19.0"/>
       <fsummary>Information about microstate accounting.</fsummary>
       <desc>
         <p>Microstate accounting can be used to measure how much time the Erlang
@@ -6561,7 +6680,7 @@ lists:map(
           <tag><c>async</c></tag>
           <item>Async threads are used by various linked-in drivers (mainly the
             file drivers) do offload non-CPU intensive work. See
-            <seealso marker="erts:erl#+async_thread_pool_size">erl +A</seealso> for more details.</item>
+            <seealso marker="erts:erl#async_thread_pool_size">erl +A</seealso> for more details.</item>
           <tag><c>aux</c></tag>
           <item>Takes care of any work that is not
             specifically assigned to a scheduler.</item>
@@ -6646,7 +6765,7 @@ lists:map(
 
     <func>
       <name name="statistics" arity="1" clause_i="8"
-	    anchor="statistics_reductions"/>
+	    anchor="statistics_reductions" since=""/>
       <fsummary>Information about reductions.</fsummary>
       <desc>
         <p>Returns information about reductions, for example:</p>
@@ -6665,7 +6784,7 @@ lists:map(
 
     <func>
       <name name="statistics" arity="1" clause_i="9"
-	    anchor="statistics_run_queue"/>
+	    anchor="statistics_run_queue" since=""/>
       <fsummary>Information about the run-queues.</fsummary>
       <desc>
         <p>Returns the total length of all normal run-queues. That is, the number
@@ -6682,7 +6801,7 @@ lists:map(
 
     <func>
       <name name="statistics" arity="1" clause_i="10"
-	    anchor="statistics_run_queue_lengths"/>
+	    anchor="statistics_run_queue_lengths" since="OTP 18.3"/>
       <fsummary>Information about the run-queue lengths.</fsummary>
       <desc>
         <p>Returns the same as
@@ -6697,7 +6816,7 @@ lists:map(
 
     <func>
       <name name="statistics" arity="1" clause_i="11"
-	    anchor="statistics_run_queue_lengths_all"/>
+	    anchor="statistics_run_queue_lengths_all" since="OTP 20.0"/>
       <fsummary>Information about the run-queue lengths.</fsummary>
       <desc>
         <p>Returns a list where each element represents the amount
@@ -6739,7 +6858,7 @@ lists:map(
     </func>
 
     <func>
-      <name name="statistics" arity="1" clause_i="12"/>
+      <name name="statistics" arity="1" clause_i="12" since=""/>
       <fsummary>Information about runtime.</fsummary>
       <desc>
         <p>Returns information about runtime, in milliseconds.</p>
@@ -6758,7 +6877,7 @@ lists:map(
 
     <func>
       <name name="statistics" arity="1" clause_i="13"
-	    anchor="statistics_scheduler_wall_time"/>
+	    anchor="statistics_scheduler_wall_time" since="OTP R15B01"/>
       <fsummary>Information about each schedulers work time.</fsummary>
       <desc>
         <p>Returns a list of tuples with
@@ -6882,7 +7001,7 @@ ok
 
     <func>
       <name name="statistics" arity="1" clause_i="14"
-	    anchor="statistics_scheduler_wall_time_all"/>
+	    anchor="statistics_scheduler_wall_time_all" since="OTP 20.0"/>
       <fsummary>Information about each schedulers work time.</fsummary>
       <desc>
 	<p>The same as
@@ -6910,7 +7029,7 @@ ok
     </func>
     <func>
       <name name="statistics" arity="1" clause_i="15"
-	    anchor="statistics_total_active_tasks"/>
+	    anchor="statistics_total_active_tasks" since="OTP 18.3"/>
       <fsummary>Information about active processes and ports.</fsummary>
       <desc>
         <p>The same as calling
@@ -6921,7 +7040,7 @@ ok
 
     <func>
       <name name="statistics" arity="1" clause_i="16"
-	    anchor="statistics_total_active_tasks_all"/>
+	    anchor="statistics_total_active_tasks_all" since="OTP 20.0"/>
       <fsummary>Information about active processes and ports.</fsummary>
       <desc>
         <p>The same as calling
@@ -6932,7 +7051,7 @@ ok
 
     <func>
       <name name="statistics" arity="1" clause_i="17"
-	    anchor="statistics_total_run_queue_lengths"/>
+	    anchor="statistics_total_run_queue_lengths" since="OTP 18.3"/>
       <fsummary>Information about the run-queue lengths.</fsummary>
       <desc>
         <p>The same as calling
@@ -6943,7 +7062,7 @@ ok
 
     <func>
       <name name="statistics" arity="1" clause_i="18"
-	    anchor="statistics_total_run_queue_lengths_all"/>
+	    anchor="statistics_total_run_queue_lengths_all" since="OTP 20.0"/>
       <fsummary>Information about the run-queue lengths.</fsummary>
       <desc>
         <p>The same as calling
@@ -6953,7 +7072,7 @@ ok
     </func>
 
     <func>
-      <name name="statistics" arity="1" clause_i="19"/>
+      <name name="statistics" arity="1" clause_i="19" since=""/>
       <fsummary>Information about wall clock.</fsummary>
       <desc>
         <p>Returns information about wall clock. <c>wall_clock</c> can
@@ -6964,7 +7083,7 @@ ok
     </func>
 
     <func>
-      <name name="suspend_process" arity="1"/>
+      <name name="suspend_process" arity="1" since=""/>
       <fsummary>Suspend a process.</fsummary>
       <desc>
         <p>Suspends the process identified by
@@ -6979,7 +7098,7 @@ ok
     </func>
 
     <func>
-      <name name="suspend_process" arity="2"/>
+      <name name="suspend_process" arity="2" since=""/>
       <fsummary>Suspend a process.</fsummary>
       <desc>
         <p>Increases the suspend count on the process identified by
@@ -7125,7 +7244,7 @@ ok
     </func>
 
     <func>
-      <name name="system_flag" arity="2" clause_i="1"/>
+      <name name="system_flag" arity="2" clause_i="1" since=""/>
       <fsummary>Set system flag <c>backtrace_depth</c>.</fsummary>
       <desc>
         <p>Sets the maximum depth of call stack back-traces in the
@@ -7138,7 +7257,7 @@ ok
 
     <func>
       <name name="system_flag" arity="2" clause_i="2"
-	    anchor="system_flag_cpu_topology"/>
+	    anchor="system_flag_cpu_topology" since=""/>
       <fsummary>Set system flag <c>cpu_topology</c>.</fsummary>
       <type name="cpu_topology"/>
       <type name="level_entry"/>
@@ -7186,7 +7305,7 @@ ok
 
     <func>
       <name name="system_flag" arity="2" clause_i="3"
-	    anchor="system_flag_dirty_cpu_schedulers_online"/>
+	    anchor="system_flag_dirty_cpu_schedulers_online" since="OTP 17.0"/>
       <fsummary>Set system_flag_dirty_cpu_schedulers_online.</fsummary>
       <desc>
         <p>
@@ -7214,7 +7333,7 @@ ok
     </func>
 
     <func>
-      <name name="system_flag" arity="2" clause_i="4"/>
+      <name name="system_flag" arity="2" clause_i="4" since="OTP 20.2.3"/>
       <fsummary>Set system flag for erts_alloc.</fsummary>
       <desc>
         <p>Sets system flags for
@@ -7231,7 +7350,7 @@ ok
     </func>
 
     <func>
-      <name name="system_flag" arity="2" clause_i="5"/>
+      <name name="system_flag" arity="2" clause_i="5" since=""/>
       <fsummary>Set system flag fullsweep_after.</fsummary>
       <desc>
         <p>Sets system flag <c>fullsweep_after</c>.
@@ -7251,7 +7370,7 @@ ok
 
     <func>
       <name name="system_flag" arity="2" clause_i="6"
-	    anchor="system_flag_microstate_accounting"/>
+	    anchor="system_flag_microstate_accounting" since="OTP 19.0"/>
       <fsummary>Set system flag microstate_accounting.</fsummary>
       <desc>
         <p>
@@ -7264,7 +7383,7 @@ ok
     </func>
 
     <func>
-      <name name="system_flag" arity="2" clause_i="7"/>
+      <name name="system_flag" arity="2" clause_i="7" since=""/>
       <fsummary>Set system flag min_heap_size.</fsummary>
       <desc>
         <p>Sets the default minimum heap size for processes. The size
@@ -7279,7 +7398,7 @@ ok
     </func>
 
     <func>
-      <name name="system_flag" arity="2" clause_i="8"/>
+      <name name="system_flag" arity="2" clause_i="8" since="OTP R13B04"/>
       <fsummary>Set system flag min_bin_vheap_size.</fsummary>
       <desc>
         <p>Sets the default minimum binary virtual heap size for
@@ -7297,7 +7416,7 @@ ok
 
     <func>
       <name name="system_flag" arity="2" clause_i="9"
-	    anchor="system_flag_max_heap_size"/>
+	    anchor="system_flag_max_heap_size" since="OTP 19.0"/>
       <fsummary>Set system flag max_heap_size.</fsummary>
       <type name="max_heap_size"/>
       <desc>
@@ -7315,7 +7434,7 @@ ok
 
     <func>
       <name name="system_flag" arity="2" clause_i="10"
-	    anchor="system_flag_multi_scheduling"/>
+	    anchor="system_flag_multi_scheduling" since=""/>
       <fsummary>Set system flag multi_scheduling.</fsummary>
       <desc>
         <p>
@@ -7371,7 +7490,7 @@ ok
 
     <func>
       <name name="system_flag" arity="2" clause_i="11"
-	    anchor="system_flag_scheduler_bind_type"/>
+	    anchor="system_flag_scheduler_bind_type" since=""/>
       <fsummary>Set system flag scheduler_bind_type.</fsummary>
       <type name="scheduler_bind_type"/>
       <desc>
@@ -7498,7 +7617,7 @@ ok
 
     <func>
       <name name="system_flag" arity="2" clause_i="12"
-	    anchor="system_flag_scheduler_wall_time"/>
+	    anchor="system_flag_scheduler_wall_time" since="OTP R15B01"/>
       <fsummary>Set system flag scheduler_wall_time.</fsummary>
       <desc>
         <p>
@@ -7511,7 +7630,7 @@ ok
 
     <func>
       <name name="system_flag" arity="2" clause_i="13"
-	    anchor="system_flag_schedulers_online"/>
+	    anchor="system_flag_schedulers_online" since=""/>
       <fsummary>Set system flag schedulers_online.</fsummary>
       <desc>
         <p>
@@ -7539,7 +7658,39 @@ ok
     </func>
 
     <func>
-      <name name="system_flag" arity="2" clause_i="14"/>
+      <name name="system_flag" arity="2" clause_i="14" since="OTP 21.3"/>
+      <fsummary>Set system logger process.</fsummary>
+      <desc>
+        <p>Sets the process that will receive the logging
+        messages generated by ERTS. If set to <c>undefined</c>,
+        all logging messages generated by ERTS will be dropped.
+        The messages will be in the format:</p>
+        <code>
+{log,Level,Format,ArgList,Metadata} where
+
+Level = atom(),
+Format = string(),
+ArgList = list(term()),
+Metadata = #{ pid => pid(),
+   group_leader => pid(),
+   time := logger:timestamp(),
+   error_logger := #{ emulator := true, tag := atom() }
+        </code>
+        <p>If the <c>system_logger</c> process dies,
+        this flag will be reset to <c>logger</c>.</p>
+        <p>The default is the process named <c>logger</c>.</p>
+        <p>Returns the old value of the flag.</p>
+        <note><p>This function is designed to be used by the
+        KERNEL <seealso marker="kernel:logger"><c>logger</c></seealso>.
+        Be careful if you change it to something else as
+        log messages may be lost. If you want to intercept
+        emulator log messages, do it by adding a specialized handler
+        to the KERNEL logger.</p></note>
+      </desc>
+    </func>
+
+    <func>
+      <name name="system_flag" arity="2" clause_i="15" since=""/>
       <fsummary>Set system flag trace_control_word.</fsummary>
       <desc>
         <p>Sets the value of the node trace control word to
@@ -7553,8 +7704,8 @@ ok
     </func>
 
     <func>
-      <name name="system_flag" arity="2" clause_i="15"
-	    anchor="system_flag_time_offset"/>
+      <name name="system_flag" arity="2" clause_i="16"
+	    anchor="system_flag_time_offset" since="OTP 18.0"/>
       <fsummary>Finalize the time offset.</fsummary>
       <desc>
         <p>
@@ -7583,7 +7734,7 @@ ok
     </func>
 
     <func>
-      <name name="system_info" arity="1" clause_i="76"/>
+      <name name="system_info" arity="1" clause_i="76" since=""/>
       <fsummary>System info overview.</fsummary>
       <desc>
         <p>Returns information about the current system.
@@ -7703,8 +7854,9 @@ ok
               <seealso marker="#system_info_nif_version"><c>nif_version</c></seealso>,
               <seealso marker="#system_info_otp_release"><c>otp_release</c></seealso>,
               <seealso marker="#system_info_port_parallelism"><c>port_parallelism</c></seealso>,
-              <seealso marker="#system_info_system_version"><c>system_version</c></seealso>,
               <seealso marker="#system_info_system_architecture"><c>system_architecture</c></seealso>,
+              <seealso marker="#system_info_system_logger"><c>system_logger</c></seealso>,
+              <seealso marker="#system_info_system_version"><c>system_version</c></seealso>,
               <seealso marker="#system_info_trace_control_word"><c>trace_control_word</c></seealso>,
               <seealso marker="#system_info_version"><c>version</c></seealso>,
               <seealso marker="#system_info_wordsize"><c>wordsize</c></seealso>
@@ -7716,12 +7868,12 @@ ok
 
     <func>
       <name name="system_info" arity="1" clause_i="1"
-	    anchor="system_info_allocator"/>   <!-- allocated_areas -->
-      <name name="system_info" arity="1" clause_i="2"/>   <!-- allocator -->
-      <name name="system_info" arity="1" clause_i="3"/>   <!-- {allocator, _} -->
-      <name name="system_info" arity="1" clause_i="4"/>   <!-- alloc_util_allocators -->
-      <name name="system_info" arity="1" clause_i="5"/>   <!-- {allocator_sizes, _} -->
-      <name name="system_info" arity="1" clause_i="27"/>  <!-- elib_malloc -->
+	    anchor="system_info_allocator" since=""/>   <!-- allocated_areas -->
+      <name name="system_info" arity="1" clause_i="2" since=""/>   <!-- allocator -->
+      <name name="system_info" arity="1" clause_i="3" since=""/>   <!-- {allocator, _} -->
+      <name name="system_info" arity="1" clause_i="4" since=""/>   <!-- alloc_util_allocators -->
+      <name name="system_info" arity="1" clause_i="5" since=""/>   <!-- {allocator_sizes, _} -->
+      <name name="system_info" arity="1" clause_i="27" since=""/>  <!-- elib_malloc -->
       <fsummary>Information about the system allocators.</fsummary>
       <type variable="Allocator" name_i="2"/>
       <type variable="Version" name_i="2"/>
@@ -7873,10 +8025,10 @@ ok
 
     <func>
       <name name="system_info" arity="1" clause_i="12"
-	    anchor="system_info_cpu_topology"/>           <!-- cpu_topology -->
-      <name name="system_info" arity="1" clause_i="13"/>  <!-- {cpu_topology, _} -->
-      <name name="system_info" arity="1" clause_i="38"/>  <!-- logical_processors -->
-      <name name="system_info" arity="1" clause_i="73"/>  <!-- update_cpu_info -->
+	    anchor="system_info_cpu_topology" since=""/>           <!-- cpu_topology -->
+      <name name="system_info" arity="1" clause_i="13" since=""/>  <!-- {cpu_topology, _} -->
+      <name name="system_info" arity="1" clause_i="38" since=""/>  <!-- logical_processors -->
+      <name name="system_info" arity="1" clause_i="74" since="OTP R14B"/>  <!-- update_cpu_info -->
       <fsummary>Information about the CPU topology of the system.</fsummary>
       <type name="cpu_topology"/>
       <type name="level_entry"/>
@@ -8028,15 +8180,15 @@ ok
 
     <func>
       <name name="system_info" arity="1" clause_i="31"
-	    anchor="system_info_process"/>  <!-- fullsweep_after -->
-      <name name="system_info" arity="1" clause_i="32"/>  <!-- garbage_collection -->
-      <name name="system_info" arity="1" clause_i="33"/>  <!-- heap_sizes -->
-      <name name="system_info" arity="1" clause_i="34"/>  <!-- heap_type -->
-      <name name="system_info" arity="1" clause_i="40"/>  <!-- max_heap_size -->
-      <name name="system_info" arity="1" clause_i="41"/>  <!-- message_queue_data -->
-      <name name="system_info" arity="1" clause_i="42"/>  <!-- min_heap_size -->
-      <name name="system_info" arity="1" clause_i="43"/>  <!-- min_bin_vheap_size -->
-      <name name="system_info" arity="1" clause_i="57"/>  <!-- procs -->
+	    anchor="system_info_process" since=""/>  <!-- fullsweep_after -->
+      <name name="system_info" arity="1" clause_i="32" since=""/>  <!-- garbage_collection -->
+      <name name="system_info" arity="1" clause_i="33" since=""/>  <!-- heap_sizes -->
+      <name name="system_info" arity="1" clause_i="34" since=""/>  <!-- heap_type -->
+      <name name="system_info" arity="1" clause_i="40" since="OTP 19.0"/>  <!-- max_heap_size -->
+      <name name="system_info" arity="1" clause_i="41" since="OTP 19.0"/>  <!-- message_queue_data -->
+      <name name="system_info" arity="1" clause_i="42" since="OTP R13B04"/>  <!-- min_heap_size -->
+      <name name="system_info" arity="1" clause_i="43" since="OTP R13B04"/>  <!-- min_bin_vheap_size -->
+      <name name="system_info" arity="1" clause_i="57" since=""/>  <!-- procs -->
       <fsummary>Information about the default process heap settings.</fsummary>
       <type name="message_queue_data"/>
       <type name="max_heap_size"/>
@@ -8146,14 +8298,14 @@ ok
     </func>
 
     <func>
-      <name name="system_info" arity="1" clause_i="6" anchor="system_info_limits"/>   <!-- atom_count -->
-      <name name="system_info" arity="1" clause_i="7"/>   <!-- atom_limit -->
-      <name name="system_info" arity="1" clause_i="29"/>  <!-- ets_count -->
-      <name name="system_info" arity="1" clause_i="30"/>  <!-- ets_limit -->
-      <name name="system_info" arity="1" clause_i="53"/>  <!-- port_count -->
-      <name name="system_info" arity="1" clause_i="54"/>  <!-- port_limit -->
-      <name name="system_info" arity="1" clause_i="55"/>  <!-- process_count -->
-      <name name="system_info" arity="1" clause_i="56"/>  <!-- process_limit -->
+      <name name="system_info" arity="1" clause_i="6" anchor="system_info_limits" since="OTP 20.0"/>   <!-- atom_count -->
+      <name name="system_info" arity="1" clause_i="7" since="OTP 20.0"/>   <!-- atom_limit -->
+      <name name="system_info" arity="1" clause_i="29" since="OTP 21.1"/>  <!-- ets_count -->
+      <name name="system_info" arity="1" clause_i="30" since="OTP R16B03"/>  <!-- ets_limit -->
+      <name name="system_info" arity="1" clause_i="53" since="OTP R16B"/>  <!-- port_count -->
+      <name name="system_info" arity="1" clause_i="54" since="OTP R16B"/>  <!-- port_limit -->
+      <name name="system_info" arity="1" clause_i="55" since=""/>  <!-- process_count -->
+      <name name="system_info" arity="1" clause_i="56" since=""/>  <!-- process_limit -->
       <fsummary>Information about various system limits.</fsummary>
       <desc>
         <marker id="system_info_limits"/>
@@ -8227,14 +8379,14 @@ ok
 
     <func>
       <name name="system_info" arity="1" clause_i="26"
-	    anchor="system_info_time"/>  <!-- end_time -->
-      <name name="system_info" arity="1" clause_i="50"/>  <!-- os_monotonic_time_source -->
-      <name name="system_info" arity="1" clause_i="51"/>  <!-- os_system_time_source -->
-      <name name="system_info" arity="1" clause_i="63"/>  <!-- start_time -->
-      <name name="system_info" arity="1" clause_i="68"/>  <!-- time_correction -->
-      <name name="system_info" arity="1" clause_i="69"/>  <!-- time_offset -->
-      <name name="system_info" arity="1" clause_i="70"/>  <!-- time_warp_mode -->
-      <name name="system_info" arity="1" clause_i="71"/>  <!-- tolerant_timeofday -->
+	    anchor="system_info_time" since="OTP 18.0"/>  <!-- end_time -->
+      <name name="system_info" arity="1" clause_i="50" since="OTP 18.0"/>  <!-- os_monotonic_time_source -->
+      <name name="system_info" arity="1" clause_i="51" since="OTP 18.0"/>  <!-- os_system_time_source -->
+      <name name="system_info" arity="1" clause_i="63" since="OTP 18.0"/>  <!-- start_time -->
+      <name name="system_info" arity="1" clause_i="69" since="OTP 18.0"/>  <!-- time_correction -->
+      <name name="system_info" arity="1" clause_i="70" since="OTP 18.0"/>  <!-- time_offset -->
+      <name name="system_info" arity="1" clause_i="71" since="OTP 18.0"/>  <!-- time_warp_mode -->
+      <name name="system_info" arity="1" clause_i="72" since="OTP 17.1"/>  <!-- tolerant_timeofday -->
       <fsummary>Information about system time.</fsummary>
       <desc>
         <marker id="system_info_time_tags"/>
@@ -8324,7 +8476,7 @@ ok
               system time</seealso> that is used by the runtime system.</p>
             <p>The list contains two-tuples with <c>Key</c>s
               as first element, and <c>Value</c>s as second element. The
-              order if these tuples is undefined. The following
+              order of these tuples is undefined. The following
               tuples can be part of the list, but more tuples can be
               introduced in the future:</p>
             <taglist>
@@ -8455,19 +8607,19 @@ ok
 
     <func>
       <name name="system_info" arity="1" clause_i="17"
-	    anchor="system_info_scheduler"/>  <!-- dirty_cpu_schedulers -->
-      <name name="system_info" arity="1" clause_i="18"/>  <!-- dirty_cpu_schedulers_online -->
-      <name name="system_info" arity="1" clause_i="19"/>  <!-- dirty_io_schedulers -->
-      <name name="system_info" arity="1" clause_i="45"/>  <!-- multi_scheduling -->
-      <name name="system_info" arity="1" clause_i="46"/>  <!-- multi_scheduling_blockers -->
-      <name name="system_info" arity="1" clause_i="49"/>  <!-- normal_multi_scheduling_blockers -->
-      <name name="system_info" arity="1" clause_i="58"/>  <!-- scheduler_bind_type -->
-      <name name="system_info" arity="1" clause_i="59"/>  <!-- scheduler_bindings -->
-      <name name="system_info" arity="1" clause_i="60"/>  <!-- scheduler_id -->
-      <name name="system_info" arity="1" clause_i="61"/>  <!-- schedulers -->
-      <name name="system_info" arity="1" clause_i="62"/>  <!-- smp_support -->
-      <name name="system_info" arity="1" clause_i="66"/>  <!-- threads -->
-      <name name="system_info" arity="1" clause_i="67"/>  <!-- thread_pool_size -->
+	    anchor="system_info_scheduler" since="OTP 17.0"/>  <!-- dirty_cpu_schedulers -->
+      <name name="system_info" arity="1" clause_i="18" since="OTP 17.0"/>  <!-- dirty_cpu_schedulers_online -->
+      <name name="system_info" arity="1" clause_i="19" since="OTP 17.0"/>  <!-- dirty_io_schedulers -->
+      <name name="system_info" arity="1" clause_i="45" since=""/>  <!-- multi_scheduling -->
+      <name name="system_info" arity="1" clause_i="46" since=""/>  <!-- multi_scheduling_blockers -->
+      <name name="system_info" arity="1" clause_i="49" since="OTP 19.0"/>  <!-- normal_multi_scheduling_blockers -->
+      <name name="system_info" arity="1" clause_i="58" since=""/>  <!-- scheduler_bind_type -->
+      <name name="system_info" arity="1" clause_i="59" since=""/>  <!-- scheduler_bindings -->
+      <name name="system_info" arity="1" clause_i="60" since=""/>  <!-- scheduler_id -->
+      <name name="system_info" arity="1" clause_i="61" since=""/>  <!-- schedulers -->
+      <name name="system_info" arity="1" clause_i="62" since=""/>  <!-- smp_support -->
+      <name name="system_info" arity="1" clause_i="67" since=""/>  <!-- threads -->
+      <name name="system_info" arity="1" clause_i="68" since=""/>  <!-- thread_pool_size -->
       <fsummary>Information about system schedulers.</fsummary>
       <desc>
         <marker id="system_info_scheduler_tags"/>
@@ -8755,11 +8907,11 @@ ok
 
     <func>
       <name name="system_info" arity="1" clause_i="14"
-	    anchor="system_info_dist"/>  <!-- creation -->
-      <name name="system_info" arity="1" clause_i="16"/>  <!-- delayed_node_table_gc -->
-      <name name="system_info" arity="1" clause_i="20"/>  <!-- dist -->
-      <name name="system_info" arity="1" clause_i="21"/>  <!-- dist_buf_busy_limit -->
-      <name name="system_info" arity="1" clause_i="22"/>  <!-- dist_ctrl -->
+	    anchor="system_info_dist" since=""/>  <!-- creation -->
+      <name name="system_info" arity="1" clause_i="16" since="OTP 18.0"/>  <!-- delayed_node_table_gc -->
+      <name name="system_info" arity="1" clause_i="20" since=""/>  <!-- dist -->
+      <name name="system_info" arity="1" clause_i="21" since="OTP R14B01"/>  <!-- dist_buf_busy_limit -->
+      <name name="system_info" arity="1" clause_i="22" since=""/>  <!-- dist_ctrl -->
       <fsummary>Information about erlang distribution.</fsummary>
       <desc>
         <marker id="system_info_dist_tags"/>
@@ -8833,14 +8985,14 @@ ok
       <!-- <name name="system_info" arity="1" clause_i="6"/>   atom_count -->
       <!-- <name name="system_info" arity="1" clause_i="7"/>   atom_limit -->
       <name name="system_info" arity="1" clause_i="8"
-	    anchor="system_info_misc"/>   <!-- build_type -->
-      <name name="system_info" arity="1" clause_i="9"/>   <!-- c_compiler_used -->
-      <name name="system_info" arity="1" clause_i="10"/>  <!-- check_io -->
-      <name name="system_info" arity="1" clause_i="11"/>  <!-- compat_rel -->
+	    anchor="system_info_misc" since="OTP R14B"/>   <!-- build_type -->
+      <name name="system_info" arity="1" clause_i="9" since=""/>   <!-- c_compiler_used -->
+      <name name="system_info" arity="1" clause_i="10" since=""/>  <!-- check_io -->
+      <name name="system_info" arity="1" clause_i="11" since=""/>  <!-- compat_rel -->
       <!-- <name name="system_info" arity="1" clause_i="12"/>  cpu_topology -->
       <!-- <name name="system_info" arity="1" clause_i="13"/>  {cpu_topology, _} -->
       <!-- <name name="system_info" arity="1" clause_i="14"/>  creation -->
-      <name name="system_info" arity="1" clause_i="15"/>  <!-- debug_compiled -->
+      <name name="system_info" arity="1" clause_i="15" since=""/>  <!-- debug_compiled -->
       <!-- <name name="system_info" arity="1" clause_i="16"/>  delayed_node_table_gc -->
       <!-- <name name="system_info" arity="1" clause_i="17"/>  dirty_cpu_schedulers -->
       <!-- <name name="system_info" arity="1" clause_i="18"/>  dirty_cpu_schedulers_online -->
@@ -8848,9 +9000,9 @@ ok
       <!-- <name name="system_info" arity="1" clause_i="20"/>  dist -->
       <!-- <name name="system_info" arity="1" clause_i="21"/>  dist_buf_busy_limit -->
       <!-- <name name="system_info" arity="1" clause_i="22"/>  dist_ctrl -->
-      <name name="system_info" arity="1" clause_i="23"/>  <!-- driver_version -->
-      <name name="system_info" arity="1" clause_i="24"/>  <!-- dynamic_trace -->
-      <name name="system_info" arity="1" clause_i="25"/>  <!-- dynamic_trace_probes -->
+      <name name="system_info" arity="1" clause_i="23" since=""/>  <!-- driver_version -->
+      <name name="system_info" arity="1" clause_i="24" since="OTP R15B01"/>  <!-- dynamic_trace -->
+      <name name="system_info" arity="1" clause_i="25" since="OTP R15B01"/>  <!-- dynamic_trace_probes -->
       <!-- <name name="system_info" arity="1" clause_i="26"/>  end_time -->
       <!-- <name name="system_info" arity="1" clause_i="27"/>  elib_malloc -->
       <!-- <name name="system_info" arity="1" clause_i="28"/>  eager_check_io, removed -->
@@ -8860,24 +9012,24 @@ ok
       <!-- <name name="system_info" arity="1" clause_i="32"/>  garbage_collection -->
       <!-- <name name="system_info" arity="1" clause_i="33"/>  heap_sizes -->
       <!-- <name name="system_info" arity="1" clause_i="34"/>  heap_type -->
-      <name name="system_info" arity="1" clause_i="35"/>  <!-- info -->
-      <name name="system_info" arity="1" clause_i="36"/>  <!-- kernel_poll -->
-      <name name="system_info" arity="1" clause_i="37"/>  <!-- loaded -->
+      <name name="system_info" arity="1" clause_i="35" since=""/>  <!-- info -->
+      <name name="system_info" arity="1" clause_i="36" since=""/>  <!-- kernel_poll -->
+      <name name="system_info" arity="1" clause_i="37" since=""/>  <!-- loaded -->
       <!-- <name name="system_info" arity="1" clause_i="38"/>  logical_processors -->
-      <name name="system_info" arity="1" clause_i="39"/>  <!-- machine -->
+      <name name="system_info" arity="1" clause_i="39" since=""/>  <!-- machine -->
       <!-- <name name="system_info" arity="1" clause_i="40"/>  max_heap_size -->
       <!-- <name name="system_info" arity="1" clause_i="41"/>  message_queue_data -->
       <!-- <name name="system_info" arity="1" clause_i="42"/>  min_heap_size -->
       <!-- <name name="system_info" arity="1" clause_i="43"/>  min_bin_vheap_size -->
-      <name name="system_info" arity="1" clause_i="44"/>  <!-- modified_timing_level -->
+      <name name="system_info" arity="1" clause_i="44" since=""/>  <!-- modified_timing_level -->
       <!-- <name name="system_info" arity="1" clause_i="45"/>  multi_scheduling -->
       <!-- <name name="system_info" arity="1" clause_i="46"/>  multi_scheduling_blockers -->
-      <name name="system_info" arity="1" clause_i="47"/>  <!-- nif_version -->
+      <name name="system_info" arity="1" clause_i="47" since="OTP 17.4"/>  <!-- nif_version -->
       <!-- n<name name="system_info" arity="1" clause_i="48"/>  ormal_multi_scheduling_blockers -->
-      <name name="system_info" arity="1" clause_i="49"/>  <!-- otp_release -->
+      <name name="system_info" arity="1" clause_i="49" since=""/>  <!-- otp_release -->
       <!-- <name name="system_info" arity="1" clause_i="50"/>  os_monotonic_time_source -->
       <!-- <name name="system_info" arity="1" clause_i="51"/>  os_system_time_source -->
-      <name name="system_info" arity="1" clause_i="52"/>  <!-- port_parallelism -->
+      <name name="system_info" arity="1" clause_i="52" since="OTP R16B"/>  <!-- port_parallelism -->
       <!-- <name name="system_info" arity="1" clause_i="53"/>  port_count -->
       <!-- <name name="system_info" arity="1" clause_i="54"/>  port_limit -->
       <!-- <name name="system_info" arity="1" clause_i="55"/>  process_count -->
@@ -8889,19 +9041,20 @@ ok
       <!-- <name name="system_info" arity="1" clause_i="61"/>  schedulers -->
       <!-- <name name="system_info" arity="1" clause_i="62"/>  smp_support -->
       <!-- <name name="system_info" arity="1" clause_i="63"/>  start_time -->
-      <name name="system_info" arity="1" clause_i="64"/>  <!-- system_version -->
-      <name name="system_info" arity="1" clause_i="65"/>  <!-- system_architecture -->
-      <!-- <name name="system_info" arity="1" clause_i="66"/>  threads -->
-      <!-- <name name="system_info" arity="1" clause_i="67"/>  thread_pool_size -->
-      <!-- <name name="system_info" arity="1" clause_i="68"/>  time_correction -->
-      <!-- <name name="system_info" arity="1" clause_i="69"/>  time_offset -->
-      <!-- <name name="system_info" arity="1" clause_i="70"/>  time_warp_mode -->
-      <!-- <name name="system_info" arity="1" clause_i="71"/>  tolerant_timeofday -->
-      <name name="system_info" arity="1" clause_i="72"/>  <!-- trace_control_word -->
-      <!-- <name name="system_info" arity="1" clause_i="73"/>  update_cpu_info -->
-      <name name="system_info" arity="1" clause_i="74"/>  <!-- version -->
-      <name name="system_info" arity="1" clause_i="75"/>  <!-- wordsize -->
-      <!-- <name name="system_info" arity="1" clause_i="76"/>  overview -->
+      <name name="system_info" arity="1" clause_i="64" since=""/>  <!-- system_architecture -->
+      <name name="system_info" arity="1" clause_i="65" since="OTP 21.3"/>  <!-- system_logger -->
+      <name name="system_info" arity="1" clause_i="66" since=""/>  <!-- system_version -->
+      <!-- <name name="system_info" arity="1" clause_i="67"/>  threads -->
+      <!-- <name name="system_info" arity="1" clause_i="68"/>  thread_pool_size -->
+      <!-- <name name="system_info" arity="1" clause_i="69"/>  time_correction -->
+      <!-- <name name="system_info" arity="1" clause_i="70"/>  time_offset -->
+      <!-- <name name="system_info" arity="1" clause_i="71"/>  time_warp_mode -->
+      <!-- <name name="system_info" arity="1" clause_i="72"/>  tolerant_timeofday -->
+      <name name="system_info" arity="1" clause_i="73" since=""/>  <!-- trace_control_word -->
+      <!-- <name name="system_info" arity="1" clause_i="74"/>  update_cpu_info -->
+      <name name="system_info" arity="1" clause_i="75" since=""/>  <!-- version -->
+      <name name="system_info" arity="1" clause_i="76" since=""/>  <!-- wordsize -->
+      <!-- <name name="system_info" arity="1" clause_i="77"/>  overview -->
       <fsummary>Information about the system.</fsummary>
       <desc>
         <marker id="system_info_misc_tags"/>
@@ -9057,18 +9210,24 @@ ok
               <seealso marker="erl#+spp"><c>+spp</c></seealso>
               in <c>erl(1)</c>.</p>
           </item>
-          <tag><marker id="system_info_system_version"/>
-            <c>system_version</c></tag>
-          <item>
-            <p>Returns a string containing version number and
-              some important properties, such as the number of schedulers.</p>
-          </item>
           <tag><marker id="system_info_system_architecture"/>
             <c>system_architecture</c></tag>
           <item>
             <p>Returns a string containing the processor and OS
               architecture the emulator is built for.</p>
           </item>
+          <tag><marker id="system_info_system_logger"/>
+            <c>system_logger</c></tag>
+          <item>
+            <p>Returns the current <c>system_logger</c> as set by
+            <seealso marker="#system_flag/2"><c>erlang:system_flag(system_logger, _)</c></seealso>.</p>
+          </item>
+          <tag><marker id="system_info_system_version"/>
+            <c>system_version</c></tag>
+          <item>
+            <p>Returns a string containing version number and
+              some important properties, such as the number of schedulers.</p>
+          </item>
           <tag><marker id="system_info_trace_control_word"/>
             <c>trace_control_word</c></tag>
           <item>
@@ -9110,7 +9269,7 @@ ok
     </func>
 
     <func>
-      <name name="system_monitor" arity="0"/>
+      <name name="system_monitor" arity="0" since=""/>
       <fsummary>Current system performance monitoring settings.</fsummary>
       <type name="system_monitor_option"/>
       <desc>
@@ -9124,7 +9283,7 @@ ok
     </func>
 
     <func>
-      <name name="system_monitor" arity="1"/>
+      <name name="system_monitor" arity="1" since=""/>
       <fsummary>Set or clear system performance monitoring options.</fsummary>
       <type name="system_monitor_option"/>
       <desc>
@@ -9142,7 +9301,7 @@ ok
     </func>
 
     <func>
-      <name name="system_monitor" arity="2"/>
+      <name name="system_monitor" arity="2" since=""/>
       <fsummary>Set system performance monitoring options.</fsummary>
       <type name="system_monitor_option"/>
       <desc>
@@ -9255,6 +9414,18 @@ ok
         <p>Returns the previous system monitor settings just like
           <seealso marker="#system_monitor/0">
           <c>erlang:system_monitor/0</c></seealso>.</p>
+	<p>The arguments to <c>system_monitor/2</c> specifies how all
+	  system monitoring on the node should be done, not how it should be
+	  changed. This means only one process at a time
+	  (<c><anno>MonitorPid</anno></c>) can be the receiver of system monitor
+	  messages. Also, the way to clear a specific monitor option
+	  is to not include it in the list <c><anno>Options</anno></c>. All
+	  system monitoring will, however, be cleared if the process identified by
+	  <c><anno>MonitorPid</anno></c> terminates.</p>
+	<p>There are no special option values (like zero) to clear an option.
+	  Some of the options have a unspecified minimum value. Lower values
+	  will be adjusted to the minimum value. For example, it is currently not
+	  possible to monitor all garbage collections with <c>{long_gc, 0}</c>.</p>
         <note>
           <p>If a monitoring process gets so large that it itself
             starts to cause system monitor messages when garbage
@@ -9274,7 +9445,7 @@ ok
     </func>
 
     <func>
-      <name name="system_profile" arity="0"/>
+      <name name="system_profile" arity="0" since=""/>
       <fsummary>Current system profiling settings.</fsummary>
       <type name="system_profile_option"/>
       <desc>
@@ -9289,7 +9460,7 @@ ok
     </func>
 
     <func>
-      <name name="system_profile" arity="2"/>
+      <name name="system_profile" arity="2" since=""/>
       <fsummary>Current system profiling settings.</fsummary>
       <type name="system_profile_option"/>
       <desc>
@@ -9363,7 +9534,7 @@ ok
     </func>
 
     <func>
-      <name name="system_time" arity="0"/>
+      <name name="system_time" arity="0" since="OTP 18.0"/>
       <fsummary>Current Erlang system time.</fsummary>
       <desc>
         <p>Returns current
@@ -9385,7 +9556,7 @@ ok
     </func>
 
     <func>
-      <name name="system_time" arity="1"/>
+      <name name="system_time" arity="1" since="OTP 18.0"/>
       <fsummary>Current Erlang system time.</fsummary>
       <desc>
         <p>Returns current
@@ -9407,7 +9578,7 @@ ok
     </func>
 
     <func>
-      <name name="term_to_binary" arity="1"/>
+      <name name="term_to_binary" arity="1" since=""/>
       <fsummary>Encode a term to an Erlang external term format binary.
       </fsummary>
       <desc>
@@ -9435,7 +9606,7 @@ hello
     </func>
 
     <func>
-      <name name="term_to_binary" arity="2"/>
+      <name name="term_to_binary" arity="2" since=""/>
       <fsummary>Encode a term to en Erlang external term format binary.
       </fsummary>
       <desc>
@@ -9500,7 +9671,7 @@ hello
     </func>
 
     <func>
-      <name name="throw" arity="1"/>
+      <name name="throw" arity="1" since=""/>
       <fsummary>Throw an exception.</fsummary>
       <desc>
         <p>A non-local return from a function. If evaluated within a
@@ -9514,7 +9685,7 @@ hello
     </func>
 
     <func>
-      <name name="time" arity="0"/>
+      <name name="time" arity="0" since=""/>
       <fsummary>Current time.</fsummary>
       <desc>
         <p>Returns the current time as <c>{Hour, Minute, Second}</c>.</p>
@@ -9527,7 +9698,7 @@ hello
     </func>
 
     <func>
-      <name name="time_offset" arity="0"/>
+      <name name="time_offset" arity="0" since="OTP 18.0"/>
       <fsummary>Current time offset.</fsummary>
       <desc>
         <p>Returns the current time offset between
@@ -9559,7 +9730,7 @@ hello
     </func>
 
     <func>
-      <name name="time_offset" arity="1"/>
+      <name name="time_offset" arity="1" since="OTP 18.0"/>
       <fsummary>Current time offset.</fsummary>
       <desc>
         <p>Returns the current time offset between
@@ -9578,7 +9749,7 @@ hello
     </func>
 
     <func>
-      <name name="timestamp" arity="0"/>
+      <name name="timestamp" arity="0" since="OTP 18.0"/>
       <fsummary>Current Erlang System time.</fsummary>
       <type name="timestamp"/>
       <desc>
@@ -9617,7 +9788,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="tl" arity="1"/>
+      <name name="tl" arity="1" since=""/>
       <fsummary>Tail of a list.</fsummary>
       <desc>
         <p>Returns the tail of <c><anno>List</anno></c>, that is,
@@ -9632,7 +9803,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="trace" arity="3"/>
+      <name name="trace" arity="3" since=""/>
       <fsummary>Set trace flags for a process or processes.</fsummary>
       <type name="trace_flag"/>
       <desc>
@@ -9959,6 +10130,11 @@ timestamp() ->
           time stamp flags are remembered, so if two are passed
           and the one with highest precedence later is disabled,
           the other one becomes active.</p>
+        <p>If a match specification (applicable only for <c>call</c>, <c>send</c>
+          and <c>'receive'</c> tracing) contains a <c>{message}</c> action
+          function with a non-boolean value, that value is added as an extra
+          element to the message tuple either in the last position or before
+          the timestamp (if it is present).</p>
         <p>Trace messages:</p>
         <marker id="trace_3_trace_messages"></marker>
         <taglist>
@@ -10288,7 +10464,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="trace_delivered" arity="1"/>
+      <name name="trace_delivered" arity="1" since=""/>
       <fsummary>Notification when trace has been delivered.</fsummary>
       <desc>
         <p>The delivery of trace messages (generated by
@@ -10343,7 +10519,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="trace_info" arity="2"/>
+      <name name="trace_info" arity="2" since=""/>
       <fsummary>Trace information about a process or function.</fsummary>
       <type name="trace_info_return"/>
       <type name="trace_info_item_result"/>
@@ -10479,7 +10655,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="trace_pattern" arity="2" clause_i="1"/>
+      <name name="trace_pattern" arity="2" clause_i="1" since=""/>
       <fsummary>Set trace patterns for call, send, or 'receive' tracing.
       </fsummary>
       <type name="trace_pattern_mfa"/>
@@ -10497,7 +10673,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="trace_pattern" arity="3" clause_i="1"/>
+      <name name="trace_pattern" arity="3" clause_i="1" since="OTP 19.0"/>
       <fsummary>Set trace pattern for message sending.</fsummary>
       <type name="trace_match_spec"/>
       <type name="match_variable"/>
@@ -10568,7 +10744,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="trace_pattern" arity="3" clause_i="2"/>
+      <name name="trace_pattern" arity="3" clause_i="2" since="OTP 19.0"/>
       <fsummary>Set trace pattern for tracing of message receiving.</fsummary>
       <type name="trace_match_spec"/>
       <type name="match_variable"/>
@@ -10640,7 +10816,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="trace_pattern" arity="3" clause_i="3"/>
+      <name name="trace_pattern" arity="3" clause_i="3" since=""/>
       <fsummary>Set trace patterns for tracing of function calls.</fsummary>
       <type name="trace_pattern_mfa"/>
       <type name="trace_match_spec"/>
@@ -10831,7 +11007,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="trunc" arity="1"/>
+      <name name="trunc" arity="1" since=""/>
       <fsummary>Return an integer by truncating a number.</fsummary>
       <desc>
         <p>Returns an integer by truncating <c><anno>Number</anno></c>,
@@ -10844,7 +11020,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="tuple_size" arity="1"/>
+      <name name="tuple_size" arity="1" since=""/>
       <fsummary>Return the size of a tuple.</fsummary>
       <desc>
         <p>Returns an integer that is the number of elements in
@@ -10857,7 +11033,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="tuple_to_list" arity="1"/>
+      <name name="tuple_to_list" arity="1" since=""/>
       <fsummary>Convert a tuple to a list.</fsummary>
       <desc>
         <p>Returns a list corresponding to <c><anno>Tuple</anno></c>.
@@ -10870,7 +11046,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="unique_integer" arity="0"/>
+      <name name="unique_integer" arity="0" since="OTP 18.0"/>
       <fsummary>Get a unique integer value.</fsummary>
       <desc>
         <p>Generates and returns an
@@ -10883,7 +11059,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="unique_integer" arity="1"/>
+      <name name="unique_integer" arity="1" since="OTP 18.0"/>
       <fsummary>Get a unique integer value.</fsummary>
       <desc>
         <p>Generates and returns an
@@ -10965,7 +11141,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="universaltime" arity="0"/>
+      <name name="universaltime" arity="0" since=""/>
       <fsummary>Current date and time according to Universal Time Coordinated
         (UTC).</fsummary>
       <desc>
@@ -10982,7 +11158,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="universaltime_to_localtime" arity="1"/>
+      <name name="universaltime_to_localtime" arity="1" since=""/>
       <fsummary>Convert from Universal Time Coordinated (UTC) to local date
         and time.</fsummary>
       <desc>
@@ -11001,7 +11177,7 @@ timestamp() ->
     </func>
 
     <func>
-      <name name="unlink" arity="1"/>
+      <name name="unlink" arity="1" since=""/>
       <fsummary>Remove a link to another process or port.</fsummary>
       <desc>
         <p>Removes the link, if there is one, between the calling
@@ -11047,7 +11223,7 @@ end</code>
     </func>
 
     <func>
-      <name name="unregister" arity="1"/>
+      <name name="unregister" arity="1" since=""/>
       <fsummary>Remove the registered name for a process (or port).</fsummary>
       <desc>
         <p>Removes the registered name <c><anno>RegName</anno></c>
@@ -11063,7 +11239,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="whereis" arity="1"/>
+      <name name="whereis" arity="1" since=""/>
       <fsummary>Get the pid (or port) with a specified registered name.
       </fsummary>
       <desc>
@@ -11077,7 +11253,7 @@ true</pre>
     </func>
 
     <func>
-      <name name="yield" arity="0"/>
+      <name name="yield" arity="0" since=""/>
       <fsummary>Let other processes get a chance to execute.</fsummary>
       <desc>
         <p>Voluntarily lets other processes (if any) get a chance to
diff --git a/erts/doc/src/erts_alloc.xml b/erts/doc/src/erts_alloc.xml
index a094217959..962bc9a244 100644
--- a/erts/doc/src/erts_alloc.xml
+++ b/erts/doc/src/erts_alloc.xml
@@ -487,11 +487,10 @@
             utilization value used. Once a carrier is abandoned, no new
             allocations are made in it. When an allocator instance gets an
             increased multiblock carrier need, it first tries to fetch an
-            abandoned carrier from an allocator instance of the same
-            allocator type. If no abandoned carrier can be fetched, it
-            creates a new empty carrier. When an abandoned carrier has been
-            fetched, it will function as an ordinary carrier. This feature has
-            special requirements on the
+            abandoned carrier from another allocator instance. If no abandoned
+            carrier can be fetched, it creates a new empty carrier. When an
+            abandoned carrier has been fetched, it will function as an ordinary
+            carrier. This feature has special requirements on the
             <seealso marker="#M_as">allocation strategy</seealso> used. Only
             the strategies <c>aoff</c>, <c>aoffcbf</c>, <c>aoffcaobf</c>,
 	    <c>ageffcaoff</c>m, <c>ageffcbf</c> and <c>ageffcaobf</c>
@@ -584,7 +583,7 @@
             carriers are decided in section
             <seealso marker="#mseg_mbc_sizes">
             The alloc_util Framework</seealso>. On
-            32-bit Unix style OS this limit cannot be set &gt; 128 MB.</p>
+            32-bit Unix style OS this limit cannot be set &gt; 64 MB.</p>
         </item>
         <tag><marker id="M_mbcgs"/><c><![CDATA[+M<S>mbcgs <ratio>]]></c></tag>
         <item>
diff --git a/erts/doc/src/init.xml b/erts/doc/src/init.xml
index c14f0a558d..c824e37976 100644
--- a/erts/doc/src/init.xml
+++ b/erts/doc/src/init.xml
@@ -29,7 +29,7 @@
     <rev></rev>
     <file>init.xml</file>
   </header>
-  <module>init</module>
+  <module since="">init</module>
   <modulesummary>Coordination of system startup.</modulesummary>
   <description>
     <p>This module is preloaded and contains the code for
@@ -50,7 +50,7 @@
 
   <funcs>
     <func>
-      <name name="boot" arity="1"/>
+      <name name="boot" arity="1" since=""/>
       <fsummary>Start the Erlang runtime system.</fsummary>
       <desc>
         <p>Starts the Erlang runtime system. This function is called
@@ -69,7 +69,7 @@
     </func>
 
     <func>
-      <name name="get_argument" arity="1"/>
+      <name name="get_argument" arity="1" since=""/>
       <fsummary>Get the values associated with a command-line user flag.
       </fsummary>
       <desc>
@@ -112,7 +112,7 @@
     </func>
 
     <func>
-      <name name="get_arguments" arity="0"/>
+      <name name="get_arguments" arity="0" since=""/>
       <fsummary>Get all command-line user flags.</fsummary>
       <desc>
         <p>Returns all command-line flags and the system-defined flags, see
@@ -121,7 +121,7 @@
     </func>
 
     <func>
-      <name name="get_plain_arguments" arity="0"/>
+      <name name="get_plain_arguments" arity="0" since=""/>
       <fsummary>Get all non-flag command-line arguments.</fsummary>
       <desc>
         <p>Returns any plain command-line arguments as a list of strings
@@ -130,7 +130,7 @@
     </func>
 
     <func>
-      <name name="get_status" arity="0"/>
+      <name name="get_status" arity="0" since=""/>
       <fsummary>Get system status information.</fsummary>
       <type name="internal_status"/>
       <desc>
@@ -146,7 +146,7 @@
     </func>
 
     <func>
-      <name name="reboot" arity="0"/>
+      <name name="reboot" arity="0" since=""/>
       <fsummary>Take down and restart an Erlang node smoothly.</fsummary>
       <desc>
         <p>All applications are taken down smoothly, all code is
@@ -162,7 +162,7 @@
     </func>
 
     <func>
-      <name name="restart" arity="0"/>
+      <name name="restart" arity="0" since=""/>
       <fsummary>Restart the running Erlang node.</fsummary>
       <desc>
         <p>The system is restarted <em>inside</em> the running Erlang
@@ -178,7 +178,7 @@
     </func>
 
     <func>
-      <name name="script_id" arity="0"/>
+      <name name="script_id" arity="0" since=""/>
       <fsummary>Get the identity of the used boot script.</fsummary>
       <desc>
         <p>Gets the identity of the boot script used to boot the system.
@@ -189,7 +189,7 @@
     </func>
 
     <func>
-      <name name="stop" arity="0"/>
+      <name name="stop" arity="0" since=""/>
       <fsummary>Take down an Erlang node smoothly.</fsummary>
       <desc>
         <p>The same as
@@ -198,7 +198,7 @@
     </func>
 
     <func>
-      <name name="stop" arity="1"/>
+      <name name="stop" arity="1" since=""/>
       <fsummary>Take down an Erlang node smoothly.</fsummary>
       <desc>
         <p>All applications are taken down smoothly, all code is
diff --git a/erts/doc/src/internal.xml b/erts/doc/src/internal.xml
new file mode 100644
index 0000000000..88609d492a
--- /dev/null
+++ b/erts/doc/src/internal.xml
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE part SYSTEM "part.dtd">
+
+<internal xmlns:xi="http://www.w3.org/2001/XInclude">
+  <header>
+    <copyright>
+      <year>2018</year><year>2018</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      Licensed under the Apache License, Version 2.0 (the "License");
+      you may not use this file except in compliance with the License.
+      You may obtain a copy of the License at
+ 
+          http://www.apache.org/licenses/LICENSE-2.0
+
+      Unless required by applicable law or agreed to in writing, software
+      distributed under the License is distributed on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+      See the License for the specific language governing permissions and
+      limitations under the License.
+    
+    </legalnotice>
+
+    <title>ERTS Internal Documentation</title>
+    <prepared>Lukas Larsson</prepared>
+    <docno></docno>
+    <date>2018-07-07</date>
+    <rev>4.5.2</rev>
+    <file>internal.xml</file>
+  </header>
+  <xi:include href="CarrierMigration.xml"/>
+  <xi:include href="ThreadProgress.xml"/>
+  <xi:include href="CodeLoading.xml"/>
+  <xi:include href="Tracing.xml"/>
+  <xi:include href="DelayedDealloc.xml"/>
+  <xi:include href="beam_makeops.xml"/>
+  <xi:include href="CountingInstructions.xml"/>
+  <xi:include href="GarbageCollection.xml"/>
+  <xi:include href="PTables.xml"/>
+  <xi:include href="PortSignals.xml"/>
+  <xi:include href="ProcessManagementOptimizations.xml"/>
+  <xi:include href="SuperCarrier.xml"/>
+</internal>
diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml
index a34b3edd7a..5ca387ffd8 100644
--- a/erts/doc/src/notes.xml
+++ b/erts/doc/src/notes.xml
@@ -31,6 +31,1215 @@
   </header>
   <p>This document describes the changes made to the ERTS application.</p>
 
+<section><title>Erts 10.4.4</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    An invalid value test caused the socket:setopt(Socket,
+	    ip, add_membership, ip_mreq()) to fail with badarg. The
+	    same for drop_membership.</p>
+          <p>
+	    Own Id: OTP-15908 Aux Id: ERL-980 </p>
+        </item>
+        <item>
+          <p>
+	    Fixed bug causing VM crash when doing textual dump of a
+	    process containing an unhandled monitor down signal.
+	    Textual process dumps can be done with
+	    <c>erlang:system_info(procs)</c>, trace feature
+	    <c>process_dump</c>, Erlang shell break menu and a
+	    crashdump. Bug exist since OTP 21.0.</p>
+          <p>
+	    Own Id: OTP-15909 Aux Id: ERL-979 </p>
+        </item>
+        <item>
+	    <p><c>lists:subtract/2</c> would produce incorrect
+	    results for some inputs on 64-bit platforms.</p>
+          <p>
+	    Own Id: OTP-15938 Aux Id: ERL-986 </p>
+        </item>
+        <item>
+	    <p>Fixed a bug in the loader that was similar to
+	    <c>OTP-15938</c>, yielding incorrect code for some inputs
+	    on 64-bit platforms.</p>
+          <p>
+	    Own Id: OTP-15939</p>
+        </item>
+        <item>
+          <p>
+	    Fixed bug causing scheduler threads in rare cases to
+	    block spinnning indefinitely. Bug exists since OTP 21.0.</p>
+          <p>
+	    Own Id: OTP-15941 Aux Id: PR-2313 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.4.3</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>Fixed a buffer overflow when
+	    <c>binary_to_existing_atom/2</c> and
+	    <c>list_to_existing_atom/2</c> was used with the
+	    <c>latin1</c> encoding.</p>
+          <p>
+	    Own Id: OTP-15819 Aux Id: ERL-944 </p>
+        </item>
+        <item>
+          <p>
+	    The runtime system disconnected a connection if it
+	    received an <c>exit/2</c> signal where the recipient was
+	    a process on an old incarnation of the current node. That
+	    is, the receiving node had the same node name, but
+	    another "creation" number. The signal will now just be
+	    dropped since the receiving process no longer exists.</p>
+          <p>
+	    Own Id: OTP-15867 Aux Id: ERIERL-373 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.4.2</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Fixed <c>process_info(Pid,reductions)</c> to not
+	    categorically increase reduction count of the measured
+	    process <c>Pid</c>. Repeated reduction measure of an idle
+	    process will most often (but not guaranteed) return the
+	    same value, like it behaved before OTP 21.3.8.</p>
+          <p>
+	    Own Id: OTP-15865 Aux Id: ERL-964 </p>
+        </item>
+        <item>
+	    <p>Fixed an incorrect load-time optimization that could
+	    cause a crash when extracting deeply nested tuple
+	    elements.</p>
+          <p>
+	    Own Id: OTP-15871 Aux Id: ERIERL-374 </p>
+        </item>
+        <item>
+          <p>
+	    Fix bug causing VM crash when pressing P for "proc info"
+	    in Erlang shell break menu. Bug exists since OTP 22.0.</p>
+          <p>
+	    Own Id: OTP-15873 Aux Id: ERL-965 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.4.1</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>In nested use of <c>try</c>/<c>catch</c>, rethrowing
+	    an exception using <c>erlang:raise/3</c> with a different
+	    class would not always be able to change the class of the
+	    exception.</p>
+          <p>
+	    Own Id: OTP-15834 Aux Id: ERIERL-367 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.4</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Do not allocate new bitstring/binary when an empty binary
+	    is appended.</p>
+          <p>
+	    Own Id: OTP-15535 Aux Id: PR-2055 </p>
+        </item>
+        <item>
+          <p>
+	    Document that <c>process_info(_, current_function)</c>
+	    can return <c>{current_function, undefined}</c> in case
+	    of execution of native code.</p>
+          <p>
+	    Own Id: OTP-15543 Aux Id: PR-2089 </p>
+        </item>
+        <item>
+          <p>
+	    Fixed bug in <c>ets:select</c>, <c>ets:match</c> and
+	    friends which could cause the table to remain fixated (as
+	    if <c>ets:safe_fixtable</c> had been called) after the
+	    call returned. This could happen for <c>protected</c>
+	    tables if another concurrent running process transferred
+	    table ownership to the process during its
+	    ets:select/match call. Ownership can be transferred using
+	    either <c>ets:give_away</c> or the <c>heir</c> table
+	    option.</p>
+          <p>
+	    Own Id: OTP-15672</p>
+        </item>
+        <item>
+	    <p>Fixed a Windows-specific bug in <c>file:list_dir/1</c>
+	    that caused it to misbehave on network shares.</p>
+          <p>
+	    Own Id: OTP-15693</p>
+        </item>
+        <item>
+          <p>
+	    Fixed bug when calling <c>enif_whereis_*</c> from NIF
+	    resource destructor. Symptoms could be emulator crash or
+	    hanging scheduler threads.</p>
+          <p>
+	    Own Id: OTP-15694 Aux Id: ERL-863 </p>
+        </item>
+        <item>
+	    <p>Fixed a bug in the error case of <c>apply/3</c>, where
+	    the exception would erroneously have an empty argument
+	    list in some cases.</p>
+          <p>
+	    Own Id: OTP-15698</p>
+        </item>
+        <item>
+	    <p>A bug has been fixed in the <c>maps</c> implementation
+	    that could cause a crash or memory usage to grow until
+	    the machine ran out of memory. This could happen when
+	    inserting a new key-value pair with a key <c>K1</c>
+	    containing a binary <c>B1</c> into a map <c>M</c> having
+	    a key <c>K2</c> with a binary <c>B2</c> if the following
+	    conditions were met:</p> <list> <item><c>B1 =/=
+	    B2</c></item> <item><c>size(B1) >= 4294967296</c></item>
+	    <item><c>size(B2) >= 4294967296</c></item>
+	    <item><c>size(M) >= 32</c></item> <item><c>(size(B1) rem
+	    4294967296) == (size(B2) rem 4294967296)</c></item>
+	    <item>the first <c>(size(B1) rem 4294967296)</c> bytes
+	    are the same both in <c>B1</c> and <c>B2</c></item>
+	    <item>substituting <c>B1</c> in <c>K1</c> with <c>B2</c>
+	    would create a term with the same value as
+	    <c>K2</c></item> </list> <p>The root cause of the problem
+	    is that the <c>maps</c> implementation only hashed the
+	    first <c>(X rem 4294967296)</c> bytes of binaries so that
+	    different binaries could get the same hash value
+	    independently of the hash seed.</p>
+          <p>
+	    Own Id: OTP-15707</p>
+        </item>
+        <item>
+          <p>
+	    <c>term_to_binary()</c> and distributed sends will now
+	    throw a <c>system_limit</c> exception instead of
+	    producing erroneous results when trying to encode a
+	    binary larger than 4 GB.</p>
+          <p>
+	    Own Id: OTP-15708</p>
+        </item>
+        <item>
+          <p>
+	    The vxworks configure has been updated to respect the
+	    environment CFLAGS.</p>
+          <p>
+	    Own Id: OTP-15773</p>
+        </item>
+        <item>
+          <p>
+	    Fix configure to not enable PGO (profile guided
+	    optimizations) when linking of the PGO binary fails. For
+	    instance this happens when there is no gcov lib
+	    installed.</p>
+          <p>
+	    Own Id: OTP-15788</p>
+        </item>
+        <item>
+          <p>
+	    Fix bug on OpenBSD where sockets using <c>active,
+	    true</c> or <c>active, N</c> could cause the system to
+	    live lock. The bug was introduced in erts-10.2
+	    (OTP-21.2).</p>
+          <p>
+	    Own Id: OTP-15791</p>
+        </item>
+      </list>
+    </section>
+
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+	    Add support for Erlang Distribution protocol to split the
+	    payload of large signals into several fragments. This
+	    allows other processes to communicate uninterrupted
+	    during the transmission of these signals.</p>
+          <p>
+	    Own Id: OTP-13397</p>
+        </item>
+        <item>
+          <p>
+	    A simple socket API is provided through the socket
+	    module. This is a low level API that does *not* replace
+	    gen_[tcp|udp|sctp]. It is intended to *eventually*
+	    replace the inet driver, but not the high level
+	    gen-modules (gen_tcp, gen_udp and gen_sctp). It also
+	    provides a basic API that facilitates the implementation
+	    of other protocols, that is TCP, UDP and SCTP. </p>
+          <p>
+	    Known issues are; No support for the Windows OS
+	    (currently).</p>
+          <p>
+	    Own Id: OTP-14831</p>
+        </item>
+        <item>
+	    <p>Added NIF functions <seealso
+	    marker="erl_nif#enif_set_pid_undefined"><c>enif_set_pid_undefined</c></seealso>,
+	    <seealso
+	    marker="erl_nif#enif_is_pid_undefined"><c>enif_is_pid_undefined</c></seealso>
+	    and <seealso
+	    marker="erl_nif#enif_compare_pids"><c>enif_compare_pids</c></seealso>.</p>
+          <p>
+	    Own Id: OTP-15011 Aux Id: PR-2147 </p>
+        </item>
+        <item>
+	    <p>Underutilized memory segments (carriers) can now move
+	    between all allocator instances, rather than just between
+	    instances of the same type, which greatly reduces memory
+	    usage in some scenarios. </p>
+          <p>
+	    Own Id: OTP-15063</p>
+        </item>
+        <item>
+	    <p>The emulator will now mark free blocks in pooled
+	    carriers with <c>madvise(2) + MADV_FREE</c> (or similar),
+	    letting the OS reclaim the associated physical memory if
+	    necessary.</p>
+          <p>
+	    Own Id: OTP-15075</p>
+        </item>
+        <item>
+          <p>
+	    New <c>ERL_NIF_SELECT_CANCEL</c> feature added to
+	    <c>enif_select</c> in order to cancel (or "deselect") a
+	    read or write event on a previously selected file
+	    descriptor.</p>
+          <p>
+	    Own Id: OTP-15095</p>
+        </item>
+        <item>
+          <p>
+	    ETS option <c>write_concurrency</c> now also affects and
+	    improves the scalability of <c>ordered_set</c> tables.
+	    The implementation is based on a data structure called
+	    contention adapting search tree, where the lock
+	    granularity adapts to the actual amount of concurrency
+	    exploited by the applications in runtime.</p>
+          <p>
+	    Own Id: OTP-15128</p>
+        </item>
+        <item>
+          <p>
+	    Build configuration of the <c>crypto</c> application has
+	    been moved from the <c>erts</c> application into the
+	    <c>crypto</c> application.</p>
+          <p>
+	    Own Id: OTP-15129</p>
+        </item>
+        <item>
+	    <p>Anonymous functions that don't capture environment are
+	    now created at load-time instead of in run-time.</p>
+          <p>
+	    Own Id: OTP-15195 Aux Id: PR-1812 </p>
+        </item>
+        <item>
+          <p>
+	    Optimize updates of maps with identical keys and values.
+	    E.g. in the example below the original Map will be reused
+	    as the return of the update.</p>
+          <p>
+	    1> Map = #{ a => b }. #{ a => b } 2> Map#{ a := b }.</p>
+          <p>
+	    Own Id: OTP-15211 Aux Id: PR-1889 </p>
+        </item>
+        <item>
+          <p>
+	    Optimize <c>binary:match/2</c> and
+	    <c>binary:matches/2</c> to use memchr internally.</p>
+          <p>
+	    Own Id: OTP-15238 Aux Id: PR-1803 </p>
+        </item>
+        <item>
+          <p>
+	    The runtime system used to terminate when a message
+	    larger than 2 Gb was passed over the distribution. The
+	    send operation will now instead throw a
+	    <c>system_limit</c> exception.</p>
+          <p>
+	    Own Id: OTP-15261</p>
+        </item>
+        <item>
+          <p>
+	    Change the first module called by erts to be named
+	    erl_init instead of otp_ring0. systools in sasl have been
+	    updated to reflect this change.</p>
+          <p>
+	    Own Id: OTP-15336 Aux Id: PR-1825 </p>
+        </item>
+        <item>
+          <p>
+	    Minor adjustments made to build system for parallel
+	    configure.</p>
+          <p>
+	    Own Id: OTP-15340 Aux Id: OTP-14625 </p>
+        </item>
+        <item>
+          <p>
+	    Two new NIF interface functions <c>enif_select_read</c>
+	    and <c>enif_select_write</c>. They are similar to
+	    existing <c>enif_select</c> but allow a custom event
+	    message as an argument.</p>
+          <p>
+	    Own Id: OTP-15349 Aux Id: PR-2084 </p>
+        </item>
+        <item>
+	    <p>The embedded copy of <c>zlib</c> has been updated from
+	    <c>1.2.8</c> to <c>1.2.11</c>.</p>
+	    <p>Note that this copy is only used as a fallback when
+	    the target platform doesn't provide any <c>zlib</c>
+	    development libraries. If your system provides
+	    <c>zlib</c> then it will be used even if it is older than
+	    <c>1.2.11</c>.</p>
+          <p>
+	    Own Id: OTP-15351 Aux Id: ERL-749 </p>
+        </item>
+        <item>
+          <p>
+	    New NIF function <c>enif_make_monitor_term</c>.</p>
+          <p>
+	    Own Id: OTP-15362 Aux Id: PR-2127 </p>
+        </item>
+        <item>
+	    <p>Appending lists (The ++ operator) will now yield
+	    properly on large inputs.</p>
+          <p>
+	    Own Id: OTP-15427</p>
+        </item>
+        <item>
+	    <p>The <c>length/1</c> BIF used to calculate the length
+	    of the list in one go without yielding, even if the list
+	    was very long. In OTP 22, <c>length/1</c> will yield when
+	    called with long lists.</p>
+          <p>
+	    Own Id: OTP-15439</p>
+        </item>
+        <item>
+          <p>
+	    Processes sending messages are now punished with a
+	    reduction cost based on message size. That is, a process
+	    sending a large message will yield earlier than before.</p>
+          <p>
+	    Own Id: OTP-15513 Aux Id: ERL-773 </p>
+        </item>
+        <item>
+	    <p>The transitory emulator option <c>+ztma true</c>
+	    (introduced in OTP 21.3) has been removed.</p>
+          <p>
+	    Own Id: OTP-15581 Aux Id: OTP-15580 </p>
+        </item>
+        <item>
+	    <p>In OTP 22, HiPE (the native code compiler) is not
+	    fully functional. The reasons for this are:</p>
+	    <p>There are new BEAM instructions for binary matching
+	    that the HiPE native code compiler does not support.</p>
+	    <p>The new optimizations in the Erlang compiler create
+	    new combination of instructions that HiPE currently does
+	    not handle correctly.</p>
+	    <p>If erlc is invoked with the <c>+native</c> option, and
+	    if any of the new binary matching instructions are used,
+	    the compiler will issue a warning and produce a BEAM file
+	    without native code.</p>
+          <p>
+	    Own Id: OTP-15596</p>
+        </item>
+        <item>
+          <p>
+	    The termination behaviour of processes has changed to
+	    allow processes to yield while sending link exit/monitor
+	    down signals.</p>
+          <p>
+	    The erl crash dump has been expanded to now also include
+	    processes that are termeinating but have not yet
+	    terminated.</p>
+          <p>
+	    Own Id: OTP-15610</p>
+        </item>
+        <item>
+          <p>
+	    The dist messages EXIT, EXIT2 and MONITOR_DOWN have been
+	    updated with new versions that send the reason term as
+	    part of the payload of the message instead of as part of
+	    the control message.</p>
+          <p>
+	    The old versions are still present and can be used when
+	    communicating with nodes that don't support the new
+	    versions.</p>
+          <p>
+	    Own Id: OTP-15611</p>
+        </item>
+        <item>
+          <p>
+	    When sending messages, exit, exit2 and monitor down
+	    distributed signals, the process sending will now yield
+	    appropriately.</p>
+          <p>
+	    This means that a terminating process will yield and
+	    possibly be suspended on busy distribution entries while
+	    they are terminating. This means that any memory held by
+	    such processes will not be released until after all
+	    exit/monitor down signals have been sent.</p>
+          <p>
+	    Own Id: OTP-15612</p>
+        </item>
+        <item>
+          <p>
+	    All external pids/ports/refs created by
+	    erlang:list_to_pid/port/ref debug functions now compare
+	    equal to any other pid/port/ref with the same number from
+	    that node.</p>
+          <p>
+	    Before this change they compared differently because the
+	    node creation of the pid/port/ref did not compare equal
+	    to any real pid/port/ref creation.</p>
+          <p>
+	    This will mostly effect pids/ports/refs typed in the
+	    shell.</p>
+          <p>
+	    Own Id: OTP-15613</p>
+        </item>
+        <item>
+          <p>
+	    The <c>persistent_term</c> functions <c>put/2</c> and
+	    <c>erase/1</c> are now yielding.</p>
+          <p>
+	    Own Id: OTP-15615</p>
+        </item>
+        <item>
+          <p>
+	    A new <seealso
+	    marker="erlang#dist_ctrl_set_opt/3"><c>erlang:dist_ctrl_set_opt(DHandle,
+	    get_size, Value)</c></seealso> option has been added.
+	    This option makes it possible to configure the
+	    distribution channel identified by <c>DHandle</c> so that
+	    <seealso
+	    marker="erlang#dist_ctrl_get_data/1"><c>erlang:dist_ctrl_get_data(DHandle)</c></seealso>
+	    also returns the size of the data to pass over the
+	    channel.</p>
+          <p>
+	    Own Id: OTP-15617</p>
+        </item>
+        <item>
+	    <p>Previously, all ETS tables used centralized counter
+	    variables to keep track of the number of items stored and
+	    the amount of memory consumed. These counters can cause
+	    scalability problems (especially on big NUMA systems).
+	    This change adds an implementation of a decentralized
+	    counter and modifies the implementation of ETS so that
+	    ETS tables of type <c>ordered_set</c> with
+	    <c>write_concurrency</c> enabled use the decentralized
+	    counter. Experiments indicate that this change
+	    substantially improves the scalability of ETS
+	    <c>ordered_set</c> tables with <c>write_concurrency</c>
+	    enabled in scenarios with frequent <c>ets:insert/2</c>
+	    and <c>ets:delete/2</c> calls.</p>
+          <p>
+	    Own Id: OTP-15623 Aux Id: PR-2190 </p>
+        </item>
+        <item>
+	    <p>The <c>iolist_size/1</c> function is now yielding
+	    which means that an Erlang/OTP system will be responsive
+	    even if the applications running on the system frequently
+	    call <c>iolist_size/1</c> with large iolists.</p>
+          <p>
+	    Own Id: OTP-15631</p>
+        </item>
+        <item>
+          <p>
+	    A simple test suite for the net module has been added.</p>
+          <p>
+	    Own Id: OTP-15635</p>
+        </item>
+        <item>
+	    <p>Added the NIF function <c>enif_term_type</c>, which
+	    helps avoid long sequences of <c>enif_is_xyz</c> by
+	    returning the type of the given term. This is especially
+	    helpful for NIFs that serialize terms, such as JSON
+	    encoders, where it can improve both performance and
+	    readability.</p>
+          <p>
+	    Own Id: OTP-15640</p>
+        </item>
+        <item>
+	    <p>The last call optimization is now applied to BIFs.
+	    When calling a BIF in the tail position of a function,
+	    the return address and stack frame will now be discarded
+	    before calling the BIF. As a consequence of this change,
+	    the immediate caller of a tail-called BIF will no longer
+	    be available in stack backtraces.</p>
+          <p>
+	    Own Id: OTP-15674 Aux Id: PR-2177 </p>
+        </item>
+        <item>
+          <p>
+	    Fix GC bug where distributed messages in a processes
+	    mailbox would cause extra GCs. This can be very expensive
+	    if there many messages in the mailbox.</p>
+          <p>
+	    Own Id: OTP-15703</p>
+        </item>
+        <item>
+	    <p>Internal documentation has now been added to the
+	    <em>Erts</em> and <em>Compiler</em> applications.</p>
+	    <p>The internal documents for <em>Erts</em> describe
+	    miscellaneous interesting implementation details. Those
+	    details can change at any time.</p>
+	    <p>The internal documentation for <em>Compiler</em>
+	    documents the API for the Core Erlang modules. While we
+	    will not change those APIs without good reason, we don't
+	    give the same guarantees about backward compatibility as
+	    for the rest of the APIs in OTP.</p>
+          <p>
+	    Own Id: OTP-15715</p>
+        </item>
+        <item>
+	    <p>The performance of non-bignum integer arithmetic has
+	    been improved.</p>
+          <p>
+	    Own Id: OTP-15740</p>
+        </item>
+        <item>
+          <p>
+	    The <c>-remsh</c> option to <c>erl</c> now automatically
+	    adds the local systems hostname to the target node if no
+	    nodename is given. e.g.</p>
+          <p>
+	    <c> erl -name foo -remsh bar </c><br/> <c> erl -sname foo
+	    -remsh bar </c></p>
+          <p>
+	    Own Id: OTP-15794 Aux Id: PR-2219 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3.5.4</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Fixed bug causing VM crash when doing textual dump of a
+	    process containing an unhandled monitor down signal.
+	    Textual process dumps can be done with
+	    <c>erlang:system_info(procs)</c>, trace feature
+	    <c>process_dump</c>, Erlang shell break menu and a
+	    crashdump. Bug exist since OTP 21.0.</p>
+          <p>
+	    Own Id: OTP-15909 Aux Id: ERL-979 </p>
+        </item>
+        <item>
+	    <p><c>lists:subtract/2</c> would produce incorrect
+	    results for some inputs on 64-bit platforms.</p>
+          <p>
+	    Own Id: OTP-15938 Aux Id: ERL-986 </p>
+        </item>
+        <item>
+	    <p>Fixed a bug in the loader that was similar to
+	    <c>OTP-15938</c>, yielding incorrect code for some inputs
+	    on 64-bit platforms.</p>
+          <p>
+	    Own Id: OTP-15939</p>
+        </item>
+        <item>
+          <p>
+	    Fixed bug causing scheduler threads in rare cases to
+	    block spinnning indefinitely. Bug exists since OTP 21.0.</p>
+          <p>
+	    Own Id: OTP-15941 Aux Id: PR-2313 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3.5.3</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    If you set <c>{linger,{true,0}}</c> on a <c>gen_tcp</c>
+	    listen socket, accept a connection on that socket, and
+	    then close the accepted socket, now the linger zero
+	    setting is transferred to the accepted socket. Before
+	    this correction that information was lost and the close
+	    behaviour on the accepted socket incorrect.</p>
+          <p>
+	    Own Id: OTP-15370 Aux Id: ERIERL-353 </p>
+        </item>
+        <item>
+          <p>
+	    Fixed <c>process_info(Pid,reductions)</c> to not
+	    categorically increase reduction count of the measured
+	    process <c>Pid</c>. Repeated reduction measure of an idle
+	    process will most often (but not guaranteed) return the
+	    same value, like it behaved before OTP 21.3.8.</p>
+          <p>
+	    Own Id: OTP-15865 Aux Id: ERL-964 </p>
+        </item>
+        <item>
+          <p>
+	    The runtime system disconnected a connection if it
+	    received an <c>exit/2</c> signal where the recipient was
+	    a process on an old incarnation of the current node. That
+	    is, the receiving node had the same node name, but
+	    another "creation" number. The signal will now just be
+	    dropped since the receiving process no longer exists.</p>
+          <p>
+	    Own Id: OTP-15867 Aux Id: ERIERL-373 </p>
+        </item>
+      </list>
+    </section>
+
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+	    The possibility to send ancillary data, in particular the
+	    TOS field, has been added to <c>gen_udp:send/4,5</c>.</p>
+          <p>
+	    Own Id: OTP-15747 Aux Id: ERIERL-294 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3.5.2</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>In nested use of <c>try</c>/<c>catch</c>, rethrowing
+	    an exception using <c>erlang:raise/3</c> with a different
+	    class would not always be able to change the class of the
+	    exception.</p>
+          <p>
+	    Own Id: OTP-15834 Aux Id: ERIERL-367 </p>
+        </item>
+        <item>
+          <p>
+	    Fixed bug in <c>seq_trace:set_token(label,Term)</c> which
+	    could cause VM crash if <c>Term</c> was heap allocated
+	    (not an atom, small integer, local pid or port). Bug
+	    exists since OTP 21.0 when terms other than small
+	    integers were first allowed as labels.</p>
+          <p>
+	    Own Id: OTP-15849 Aux Id: ERL-700 </p>
+        </item>
+        <item>
+          <p>
+	    Fix <c>seq_trace:print/2</c> not to raise <c>badarg</c>
+	    exception if label is not a small integer. Bug exists
+	    since OTP 21.0.</p>
+          <p>
+	    Own Id: OTP-15859 Aux Id: ERL-700 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3.5.1</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>Fixed a buffer overflow when
+	    <c>binary_to_existing_atom/2</c> and
+	    <c>list_to_existing_atom/2</c> was used with the
+	    <c>latin1</c> encoding.</p>
+          <p>
+	    Own Id: OTP-15819 Aux Id: ERL-944 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3.5</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Fixed more bugs in <c>process_info(reductions)</c>
+	    causing it to sometimes behave non-monotonic. That is, a
+	    subsequent call toward the same process could return a
+	    lower reduction value.</p>
+          <p>
+	    Own Id: OTP-15793 Aux Id: ERIERL-337, OTP-15709 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3.4</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>Add missing documentation of new external tags
+	    <c>NEW_PID</c>, <c>NEW_PORT</c> and
+	    <c>NEWER_REFERENCE</c> introduced in OTP 19.</p> <p>These
+	    new tags are planned to be "activated" in OTP 23 when
+	    distribution capability flag <c>DFLAG_BIG_CREATION</c>
+	    becomes mandatory. Older nodes (>= 19) are able to decode
+	    these new tags and send them back to the new node. Nodes
+	    older than OTP 23 will however never encode their own
+	    local pids, ports and references using the new tags.</p>
+          <p>
+	    Own Id: OTP-15766</p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3.3</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Fix <c>erlang:open_port/2</c> with the <c>fd</c> option
+	    to correctly cleanup the pollset when the port is closed.
+	    Before this fix there would be error printouts sent to
+	    logger when the same fd was reused in a new port.</p>
+          <p>
+	    Own Id: OTP-15753 Aux Id: ERL-900 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3.2</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>Fixed a bug in <c>seq_trace:reset_trace/0</c> that
+	    could crash the emulator.</p>
+          <p>
+	    Own Id: OTP-15704</p>
+        </item>
+        <item>
+          <p>
+	    Fixed bug in <c>process_info(reductions)</c> causing it
+	    to sometimes return invalid results.</p>
+          <p>
+	    Own Id: OTP-15709 Aux Id: ERIERL-337 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3.1</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>If a suspend/resume signal pair was sent to a process
+	    while it was executing dirty, the receiving process could
+	    later end up in a suspended state indefinitely. This bug
+	    was introduced in ERTS version 10.0 (OTP 21.0).</p>
+	    <p>Suspend/resume signals are sent from <seealso
+	    marker="erts:erlang#suspend_process/1"><c>erlang:suspend_process()</c></seealso>/<seealso
+	    marker="erts:erlang#resume_process/1"><c>erlang:resume_process()</c></seealso>.
+	    The <seealso
+	    marker="runtime_tools:dbg"><c>dbg</c></seealso> trace
+	    tool utilize this functionality and could thus trigger
+	    this bug.</p>
+          <p>
+	    Own Id: OTP-15688</p>
+        </item>
+        <item>
+          <p>
+	    Fix a possible deadlock when terminating the ERTS caused
+	    by a dirty scheduler not releasing it's run-queue lock
+	    when terminating.</p>
+          <p>
+	    Own Id: OTP-15690 Aux Id: PR-2172 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.3</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>When multiplying a number by itself, a word beyond the
+	    number on the heap could be read (and ignored). This bug
+	    was extremely unlikely to actually cause a real
+	    problem.</p>
+          <p>
+	    Own Id: OTP-15484</p>
+        </item>
+        <item>
+          <p>
+	    Fix bug where doing <c>seq_trace:reset_trace()</c> while
+	    another process was doing a garbage collection could
+	    cause the run-time system to segfault.</p>
+          <p>
+	    Own Id: OTP-15490</p>
+        </item>
+        <item>
+          <p>
+	    Fix reading of ancillary data from packet oriented
+	    sockets on old Linux kernel versions. Without this fix,
+	    getting the data would cause the port to enter an
+	    infinite loop.</p>
+          <p>
+	    Own Id: OTP-15494</p>
+        </item>
+        <item>
+          <p>
+	    Fix bug where crash dumping or doing
+	    <c>erlang:system_info(procs)</c> while another process
+	    was doing a garbage collection could cause the run-time
+	    system to segfault.</p>
+          <p>
+	    Own Id: OTP-15527</p>
+        </item>
+        <item>
+          <p>
+	    Fix <c>erlang:system_info(kernel_poll)</c> to return
+	    correct value. Before this fix, the call always returned
+	    <c>false</c>.</p>
+          <p>
+	    Own Id: OTP-15556</p>
+        </item>
+        <item>
+          <p>
+	    Fix bug in <c>enif_make_map_from_arrays</c> that would
+	    produce broken maps when number of keys were 32. Bug
+	    exists since OTP 21.0.</p>
+          <p>
+	    Own Id: OTP-15567</p>
+        </item>
+        <item>
+          <p>
+	    Fix a bug in <c>binary:encode_unsigned</c> that may cause
+	    a read of uninitialized memory.</p>
+          <p>
+	    The bug existed since the function was added (OTP
+	    R16B02).</p>
+          <p>
+	    Own Id: OTP-15583 Aux Id: PR-2118 </p>
+        </item>
+        <item>
+          <p>
+	    Fixed a bug that could cause <c>heart</c> to kill an
+	    exiting node before it had time to flush all buffered
+	    writes. If environment variable
+	    <c>HEART_KILL_SIGNAL=SIGABRT</c> was set a superfluous
+	    core dump could also be generated.</p>
+          <p>
+	    Own Id: OTP-15599 Aux Id: ERIERL-298 </p>
+        </item>
+        <item>
+          <p>
+	    Fix <c>enif_consume_timeslice</c> to be a no-op on dirty
+	    scheduler and not crash debug compiled emulator.</p>
+          <p>
+	    Own Id: OTP-15604</p>
+        </item>
+        <item>
+          <p>
+	    Fixed macro redefinition warnings.</p>
+          <p>
+	    Own Id: OTP-15629</p>
+        </item>
+        <item>
+          <p>
+	    <c>to_erl</c> fixed to not garble terminal input beyond
+	    7-bit ASCII.</p>
+          <p>
+	    Own Id: OTP-15650 Aux Id: ERL-854, PR-2161 </p>
+        </item>
+        <item>
+          <p>
+	    Minor fixes for <c>make clean</c>.</p>
+          <p>
+	    Own Id: OTP-15657</p>
+        </item>
+        <item>
+          <p>
+	    Fixed a bug in all <c>ets:select*</c> and
+	    <c>ets:match*</c> functions that could in some rare cases
+	    lead to very poor performance.</p>
+          <p>
+	    Own Id: OTP-15660 Aux Id: ERL-869 </p>
+        </item>
+      </list>
+    </section>
+
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+	    Add <c>erlang:system_flag(system_logger, Pid)</c> and
+	    <c>erlang:system_info(system_logger)</c>. This
+	    system_flag can be used to set the process that will
+	    receive the logging messages generated by ERTS.</p>
+          <p>
+	    Own Id: OTP-15375</p>
+        </item>
+        <item>
+	    <p><c>integer_to_list/2</c> and
+	    <c>integer_to_binary/2</c> are now implemented in C,
+	    improving their performance.</p>
+          <p>
+	    Own Id: OTP-15503 Aux Id: PR-2052 </p>
+        </item>
+        <item>
+          <p>
+	    Improved <c>term_to_binary</c> to do more fair reduction
+	    count and yielding when encoding large byte lists
+	    (strings).</p>
+          <p>
+	    Own Id: OTP-15514 Aux Id: ERL-774 </p>
+        </item>
+        <item>
+          <p>
+	    Made internal port drivers more robust against
+	    <c>erlang:port_control</c> with invalid arguments and
+	    added documentation warnings about such abuse.</p>
+          <p>
+	    Own Id: OTP-15555 Aux Id: ERIERL-231 </p>
+        </item>
+        <item>
+          <p>
+	    Fix bug on NetBSD where the <c>exit_status</c> from a
+	    port program would never be sent.</p>
+          <p>
+	    Own Id: OTP-15558 Aux Id: ERL-725 </p>
+        </item>
+        <item>
+	    <p>There is a new function <c>persistent:term(Key,
+	    Default)</c> to allow specifying a default when looking
+	    up a persistent term.</p>
+          <p>
+	    Own Id: OTP-15576 Aux Id: ERL-843 </p>
+        </item>
+        <item>
+	    <p>A transitory emulator option '<c>+ztma true</c>' has
+	    been added to allow running existing BEAM code that
+	    relies on "tuple calls" (dispatch on parameterized
+	    modules) which has been compiled under OTP 20 or earlier.
+	    This option will be removed in OTP 22, so such modules
+	    should eventually be recompiled with the
+	    <c>+tuple_calls</c> option.</p>
+          <p>
+	    Own Id: OTP-15580 Aux Id: PR-2113 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.2.5</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>Fixes of install/release phase in build system.</p>
+	    <list> <item>The source tree was modified when
+	    installing/releasing and/or applying a patch.</item>
+	    <item>Some files were installed with wrong access
+	    rights.</item> <item>If applying a patch (using
+	    <c>otp_patch_apply</c>) as another user (except root)
+	    than the user that built the source, the documentation
+	    was not properly updated.</item> </list>
+          <p>
+	    Own Id: OTP-15551</p>
+        </item>
+        <item>
+          <p>
+	    Setting the <c>recbuf</c> size of an inet socket the
+	    <c>buffer</c> is also automatically increased. Fix a bug
+	    where the auto adjustment of inet buffer size would be
+	    triggered even if an explicit inet buffer size had
+	    already been set.</p>
+          <p>
+	    Own Id: OTP-15651 Aux Id: ERIERL-304 </p>
+        </item>
+        <item>
+          <p>
+	    Reading from UDP using active <c>true</c> or active
+	    <c>N</c> mode has been optimized when more packets than
+	    specified by <c>read_packets</c> are available on the
+	    socket.</p>
+          <p>
+	    Own Id: OTP-15652 Aux Id: ERIERL-304 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.2.4</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    When using the <c>{linger,{true,T}}</c> option;
+	    <c>gen_tcp:listen/2</c> used the full linger time before
+	    returning for example <c>eaddrinuse</c>. This bug has now
+	    been corrected.</p>
+          <p>
+	    Own Id: OTP-14728 Aux Id: ERIERL-303 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.2.3</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Fix bug where doing a <c>gen_tcp:send</c> on a socket
+	    with <c>delay_send</c> set to true could cause a segfault
+	    if the other side closes the connection.</p>
+          <p>
+	    Bug was introduced in erts-10.2 (OTP-21.2).</p>
+          <p>
+	    Own Id: OTP-15536 Aux Id: ERL-827 </p>
+        </item>
+        <item>
+          <p>
+	    Fix a race condition when a port program closes that
+	    could result in the next started port to hang during
+	    startup.</p>
+          <p>
+	    When this fault happens the following error is normally
+	    (but not always) logged:</p>
+          <p>
+	    <c> =ERROR REPORT==== 14-Jan-2019::10:45:52.868246
+	    ===</c><br/><c> Bad input fd in erts_poll()! fd=11,
+	    port=#Port&lt;0.505>, driver=spawn, name=/bin/sh -s
+	    unix:cmd </c></p>
+          <p>
+	    Bug was introduced in erts-10.0 (OTP-21.0).</p>
+          <p>
+	    Own Id: OTP-15537</p>
+        </item>
+        <item>
+          <p>
+	    Fix a bug where polling for external events could be
+	    delayed for a very long time if all active schedulers
+	    were 100% loaded.</p>
+          <p>
+	    Bug was introduced in erts-10.2 (OTP-21.2).</p>
+          <p>
+	    Own Id: OTP-15538 Aux Id: ERIERL-229 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.2.2</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>Fixed a crash when dangling files were closed after
+	    <c>init:restart/0</c>.</p>
+          <p>
+	    Own Id: OTP-15495 Aux Id: ERL-821 </p>
+        </item>
+        <item>
+          <p>
+	    A bug that could cause dirty schedulers to become
+	    unresponsive has been fixed.</p>
+          <p>
+	    Own Id: OTP-15509 Aux Id: PR-2027, PR-2093 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 10.2.1</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Fixed bug on big endian architectures when changing file
+	    permissions or ownership with <c>file:change_mode</c>,
+	    <c>change_owner</c>, <c>change_group</c> or
+	    <c>write_file_info</c>. Bug exists since OTP-21.0.</p>
+          <p>
+	    Own Id: OTP-15485</p>
+        </item>
+        <item>
+          <p>
+	    Fixed bug in <c>atomics</c> with option
+	    <c>{signed,false}</c> when returned values are <c>(1 bsl
+	    63)</c> or larger. Could cause heap corruption leading to
+	    VM crash or other unpleasant symptoms. Bug exists since
+	    OTP-21.2 when module <c>atomics</c> was introduced.</p>
+          <p>
+	    Own Id: OTP-15486 Aux Id: PR-2061 </p>
+        </item>
+        <item>
+          <p>
+	    Fixed bug in operator <c>band</c> of two negative
+	    operands causing erroneous result if the absolute value
+	    of one of the operands have the lowest <c>N*W</c> bits as
+	    zero and the other absolute value is not larger than
+	    <c>N*W</c> bits. <c>N</c> is an integer of 1 or larger
+	    and <c>W</c> is 32 or 64 depending on word size.</p>
+          <p>
+	    Own Id: OTP-15487 Aux Id: ERL-804 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
 <section><title>Erts 10.2</title>
 
     <section><title>Fixed Bugs and Malfunctions</title>
@@ -1586,6 +2795,135 @@
 
 </section>
 
+<section><title>Erts 9.3.3.11</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>Fixed a buffer overflow when
+	    <c>binary_to_existing_atom/2</c> and
+	    <c>list_to_existing_atom/2</c> was used with the
+	    <c>latin1</c> encoding.</p>
+          <p>
+	    Own Id: OTP-15819 Aux Id: ERL-944 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 9.3.3.10</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+	    <p>Fixes of install/release phase in build system.</p>
+	    <list> <item>The source tree was modified when
+	    installing/releasing and/or applying a patch.</item>
+	    <item>Some files were installed with wrong access
+	    rights.</item> <item>If applying a patch (using
+	    <c>otp_patch_apply</c>) as another user (except root)
+	    than the user that built the source, the documentation
+	    was not properly updated.</item> </list>
+          <p>
+	    Own Id: OTP-15551</p>
+        </item>
+        <item>
+          <p>
+	    Minor fixes for <c>make clean</c>.</p>
+          <p>
+	    Own Id: OTP-15657</p>
+        </item>
+        <item>
+          <p>
+	    Fixed a bug in all <c>ets:select*</c> and
+	    <c>ets:match*</c> functions that could in some rare cases
+	    lead to very poor performance.</p>
+          <p>
+	    Own Id: OTP-15660 Aux Id: ERL-869 </p>
+        </item>
+        <item>
+          <p>
+	    Fix a possible deadlock when terminating the ERTS caused
+	    by a dirty scheduler not releasing it's run-queue lock
+	    when terminating.</p>
+          <p>
+	    Own Id: OTP-15690 Aux Id: PR-2172 </p>
+        </item>
+        <item>
+	    <p>Add missing documentation of new external tags
+	    <c>NEW_PID</c>, <c>NEW_PORT</c> and
+	    <c>NEWER_REFERENCE</c> introduced in OTP 19.</p> <p>These
+	    new tags are planned to be "activated" in OTP 23 when
+	    distribution capability flag <c>DFLAG_BIG_CREATION</c>
+	    becomes mandatory. Older nodes (>= 19) are able to decode
+	    these new tags and send them back to the new node. Nodes
+	    older than OTP 23 will however never encode their own
+	    local pids, ports and references using the new tags.</p>
+          <p>
+	    Own Id: OTP-15766</p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 9.3.3.9</title>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+	    <p>Added an optional <c>./configure</c> flag to compile
+	    the emulator with spectre mitigation:
+	    <c>--with-spectre-mitigation</c></p>
+	    <p>Note that this requires a recent version of GCC with
+	    support for spectre mitigation and the
+	    <c>--mindirect-branch=thunk</c> flag, such as
+	    <c>8.1</c>.</p>
+          <p>
+	    Own Id: OTP-15430 Aux Id: ERIERL-237 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 9.3.3.8</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    A bug that could cause dirty schedulers to become
+	    unresponsive has been fixed.</p>
+          <p>
+	    Own Id: OTP-15509 Aux Id: PR-2027, PR-2093 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
+<section><title>Erts 9.3.3.7</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Fixed bug in operator <c>band</c> of two negative
+	    operands causing erroneous result if the absolute value
+	    of one of the operands have the lowest <c>N*W</c> bits as
+	    zero and the other absolute value is not larger than
+	    <c>N*W</c> bits. <c>N</c> is an integer of 1 or larger
+	    and <c>W</c> is 32 or 64 depending on word size.</p>
+          <p>
+	    Own Id: OTP-15487 Aux Id: ERL-804 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
 <section><title>Erts 9.3.3.6</title>
 
     <section><title>Improvements and New Features</title>
@@ -1947,6 +3285,22 @@
 
 </section>
 
+<section><title>Erts 9.2.0.1</title>
+
+  <section><title>Improvements and New Features</title>
+  <list>
+    <item>
+      <p>
+	Extra internal consistency checks wrt communication with
+      erl_child_setup process.</p>
+      <p>
+      Own Id: OTP-15488 Aux Id: ERIERL-231 </p>
+    </item>
+  </list>
+  </section>
+
+</section>
+  
 <section><title>Erts 9.2</title>
 
     <section><title>Fixed Bugs and Malfunctions</title>
@@ -3145,6 +4499,43 @@
 
 </section>
 
+<section><title>Erts 8.3.5.7</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Fixed bug in operator <c>band</c> of two negative
+	    operands causing erroneous result if the absolute value
+	    of one of the operands have the lowest <c>N*W</c> bits as
+	    zero and the other absolute value is not larger than
+	    <c>N*W</c> bits. <c>N</c> is an integer of 1 or larger
+	    and <c>W</c> is 32 or 64 depending on word size.</p>
+          <p>
+	    Own Id: OTP-15487 Aux Id: ERL-804 </p>
+        </item>
+      </list>
+    </section>
+
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+	    <p>Added an optional <c>./configure</c> flag to compile
+	    the emulator with spectre mitigation:
+	    <c>--with-spectre-mitigation</c></p>
+	    <p>Note that this requires a recent version of GCC with
+	    support for spectre mitigation and the
+	    <c>--mindirect-branch=thunk</c> flag, such as
+	    <c>8.1</c>.</p>
+          <p>
+	    Own Id: OTP-15430 Aux Id: ERIERL-237 </p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
 <section><title>Erts 8.3.5.6</title>
 
     <section><title>Fixed Bugs and Malfunctions</title>
@@ -7858,8 +9249,7 @@
 	    Erlang/OTP has been ported to the realtime operating
 	    system OSE. The port supports both smp and non-smp
 	    emulator. For details around the port and how to started
-	    see the User's Guide in the <seealso
-	    marker="ose:ose_intro">ose</seealso> application. </p>
+	    see the User's Guide in the <em>ose</em> application.</p>
           <p>
 	    Note that not all parts of Erlang/OTP has been ported. </p>
           <p>
@@ -8965,9 +10355,9 @@
 	    <c>fix_alloc</c> allocator, a different strategy for
 	    management of fix blocks will be used.</item> <item>The
 	    information returned from <seealso
-	    marker="erlang:system_info_allocator_tuple"><c>erlang:system_info({allocator,
+	    marker="erlang#system_info_allocator_tuple"><c>erlang:system_info({allocator,
 	    A})</c></seealso>, and <seealso
-	    marker="erlang:system_info_allocator_sizes"><c>erlang:system_info({allocator_sizes,
+	    marker="erlang#system_info_allocator_sizes"><c>erlang:system_info({allocator_sizes,
 	    A})</c></seealso> will be slightly different when this
 	    feature has been enabled. An <c>mbcs_pool</c> tuple will
 	    be present giving information about abandoned carriers,
@@ -9776,8 +11166,7 @@
 	    information about signal ordering guarantees, see the
 	    chapter on <seealso
 	    marker="erts:communication">communication</seealso> in
-	    the ERTS user's guide. The <seealso
-	    marker="erts:erl#+n">+n</seealso> command line flag of
+	    the ERTS user's guide. The <c>+n</c> command line flag of
 	    <seealso marker="erts:erl">erl(1)</seealso> can be
 	    helpful when trying to find signaling order bugs in
 	    Erlang code that have been exposed by these
@@ -10756,7 +12145,7 @@
 	    you use erlang:halt/2 with an integer first argument and
 	    an option list containing {flush,false} as the second
 	    argument. Note that now is flushing not dependant of the
-	    exit code, and you can not only flush async threads
+	    exit code, and you cannot only flush async threads
 	    operations which we deemed as a strange behaviour anyway.
 	    </p>
 	    <p>Also, erlang:halt/1,2 has gotten a new feature: If the
diff --git a/erts/doc/src/part.xml b/erts/doc/src/part.xml.src
index 05e9a24af8..9b20beffad 100644
--- a/erts/doc/src/part.xml
+++ b/erts/doc/src/part.xml.src
@@ -4,7 +4,7 @@
 <part xmlns:xi="http://www.w3.org/2001/XInclude">
   <header>
     <copyright>
-      <year>1996</year><year>2018</year>
+      <year>1996</year><year>2019</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -42,6 +42,7 @@
   <xi:include href="tty.xml"/>
   <xi:include href="driver.xml"/>
   <xi:include href="inet_cfg.xml"/>
+  %ESOCK_USE_SOCKET_USAGE_XML%
   <xi:include href="erl_ext_dist.xml"/>
   <xi:include href="erl_dist_protocol.xml"/>
 </part>
diff --git a/erts/doc/src/persistent_term.xml b/erts/doc/src/persistent_term.xml
index 29a6c67051..672b00a83a 100644
--- a/erts/doc/src/persistent_term.xml
+++ b/erts/doc/src/persistent_term.xml
@@ -29,7 +29,7 @@
     <rev></rev>
     <file>persistent_term.xml</file>
   </header>
-  <module>persistent_term</module>
+  <module since="OTP 21.2">persistent_term</module>
   <modulesummary>Persistent terms.</modulesummary>
   <description>
     <p>This module is similar to <seealso
@@ -121,19 +121,6 @@
   </section>
 
   <section>
-    <title>Warning For Many Persistent Terms</title>
-    <p>The runtime system will send a warning report to the
-    error logger if more than 20000 persistent terms have been
-    created. It will look like this:</p>
-
-<pre>
-More than 20000 persistent terms have been created.
-It is recommended to avoid creating an excessive number of
-persistent terms, as creation and deletion of persistent terms
-will be slower as the number of persistent terms increases.</pre>
-  </section>
-
-  <section>
     <title>Best Practices for Using Persistent Terms</title>
 
     <p>It is recommended to use keys like <c>?MODULE</c> or
@@ -213,7 +200,7 @@ will be slower as the number of persistent terms increases.</pre>
 
   <funcs>
     <func>
-      <name name="erase" arity="1"/>
+      <name name="erase" arity="1" since="OTP 21.2"/>
       <fsummary>Erase the name for a persistent term.</fsummary>
       <desc>
         <p>Erase the name for the persistent term with key
@@ -229,7 +216,7 @@ will be slower as the number of persistent terms increases.</pre>
     </func>
 
     <func>
-      <name name="get" arity="0"/>
+      <name name="get" arity="0" since="OTP 21.2"/>
       <fsummary>Get all persistent terms.</fsummary>
       <desc>
         <p>Retrieve the keys and values for all persistent terms.
@@ -239,7 +226,7 @@ will be slower as the number of persistent terms increases.</pre>
     </func>
 
     <func>
-      <name name="get" arity="1"/>
+      <name name="get" arity="1" since="OTP 21.2"/>
       <fsummary>Get the value for a persistent term.</fsummary>
       <desc>
         <p>Retrieve the value for the persistent term associated with
@@ -256,7 +243,23 @@ will be slower as the number of persistent terms increases.</pre>
     </func>
 
     <func>
-      <name name="info" arity="0"/>
+      <name name="get" arity="2" since="OTP 21.3"/>
+      <fsummary>Get the value for a persistent term.</fsummary>
+      <desc>
+        <p>Retrieve the value for the persistent term associated with
+        the key <c><anno>Key</anno></c>. The lookup will be made in
+	constant time and the value will not be copied to the heap
+	of the calling process.</p>
+	<p>This function returns <c><anno>Default</anno></c> if no
+	term has been stored with the key <c><anno>Key</anno></c>.</p>
+	<p>If the calling process holds on to the value of the
+	persistent term and the persistent term is deleted in the future,
+	the term will be copied to the process.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="info" arity="0" since="OTP 21.2"/>
       <fsummary>Get information about persistent terms.</fsummary>
       <desc>
         <p>Return information about persistent terms in a map. The map
@@ -272,7 +275,7 @@ will be slower as the number of persistent terms increases.</pre>
     </func>
 
     <func>
-      <name name="put" arity="2"/>
+      <name name="put" arity="2" since="OTP 21.2"/>
       <fsummary>Store a term.</fsummary>
       <desc>
         <p>Store the value <c><anno>Value</anno></c> as a persistent term and
diff --git a/erts/doc/src/ref_man.xml b/erts/doc/src/ref_man.xml.src
index a78aaa449e..7dd003763c 100644
--- a/erts/doc/src/ref_man.xml
+++ b/erts/doc/src/ref_man.xml.src
@@ -4,7 +4,7 @@
 <application xmlns:xi="http://www.w3.org/2001/XInclude">
   <header>
     <copyright>
-      <year>1996</year><year>2016</year>
+      <year>1996</year><year>2019</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -31,26 +31,27 @@
   </header>
   <description>
   </description>
-  <xi:include href="erl_prim_loader.xml"/>
-  <xi:include href="erlang.xml"/>
-  <xi:include href="init.xml"/>
-  <xi:include href="persistent_term.xml"/>
-  <xi:include href="zlib.xml"/>
+  <xi:include href="atomics.xml"/>
+  <xi:include href="counters.xml"/>
+  <xi:include href="driver_entry.xml"/>
   <xi:include href="epmd.xml"/>
   <xi:include href="erl.xml"/>
+  <xi:include href="erlang.xml"/>
   <xi:include href="erlc.xml"/>
-  <xi:include href="werl.xml"/>
-  <xi:include href="escript.xml"/>
-  <xi:include href="erlsrv.xml"/>
-  <xi:include href="start_erl.xml"/>
-  <xi:include href="run_erl.xml"/>
-  <xi:include href="start.xml"/>
   <xi:include href="erl_driver.xml"/>
-  <xi:include href="driver_entry.xml"/>
-  <xi:include href="erts_alloc.xml"/>
   <xi:include href="erl_nif.xml"/>
+  <xi:include href="erl_prim_loader.xml"/>
+  <xi:include href="erlsrv.xml"/>
   <xi:include href="erl_tracer.xml"/>
-  <xi:include href="atomics.xml"/>
-  <xi:include href="counters.xml"/>
+  <xi:include href="erts_alloc.xml"/>
+  <xi:include href="escript.xml"/>
+  <xi:include href="init.xml"/>
+  <xi:include href="persistent_term.xml"/>
+  <xi:include href="run_erl.xml"/>
+  %ESOCK_USE_SOCKET_XML%
+  <xi:include href="start.xml"/>
+  <xi:include href="start_erl.xml"/>
+  <xi:include href="werl.xml"/>
+  <xi:include href="zlib.xml"/>
 </application>
 
diff --git a/erts/doc/src/socket.xml b/erts/doc/src/socket.xml
new file mode 100644
index 0000000000..2f7ff2fc07
--- /dev/null
+++ b/erts/doc/src/socket.xml
@@ -0,0 +1,956 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd">
+
+<erlref>
+  <header>
+    <copyright>
+      <year>2018</year><year>2019</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      Licensed under the Apache License, Version 2.0 (the "License");
+      you may not use this file except in compliance with the License.
+      You may obtain a copy of the License at
+ 
+          http://www.apache.org/licenses/LICENSE-2.0
+
+      Unless required by applicable law or agreed to in writing, software
+      distributed under the License is distributed on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+      See the License for the specific language governing permissions and
+      limitations under the License.
+
+    </legalnotice>
+
+    <title>socket</title>
+    <prepared></prepared>
+    <docno></docno>
+    <date></date>
+    <rev></rev>
+    <file>socket.xml</file>
+  </header>
+  <module since="OTP 22.0">socket</module>
+  <modulesummary>Socket interface.</modulesummary>
+  <description>
+    <p>This module provides an API for the socket interface.
+    It is used to create, delete and manipulate sockets,
+    send and receive data.</p>
+    <p>The idea is that it shall be as "close as possible" to the OS
+    level socket interface. The only significant addition is that some of
+    the functions,
+    e.g. <seealso marker="#recv/3"><c>recv/3</c></seealso>, 
+    has a timeout argument. </p>
+    <note>
+      <p>Some functions allow for an <i>asynchronous</i> call.
+      This is achieved by setting the <c>Timeout</c> argument to
+      <c>nowait</c>. For instance, if calling the
+      <seealso marker="#recv_async"><c>recv/3</c></seealso>
+      function with Timeout set to <c>nowait</c> (<c>recv(Sock, 0, nowait)</c>)
+      when there is actually nothing to read, it will return with
+      <c>{select, </c>
+      <seealso marker="#type-select_info"><c>SelectInfo</c></seealso><c>}</c>
+      (<c>SelectInfo</c> contains the
+      <seealso marker="socket#type-select_ref">SelectRef</seealso>).
+      When data eventually arrives a 'select' message
+      will be sent to the caller: </p>
+      <taglist>
+	<!-- NOTE THAT THE EMPTY TAG IS INTENTIONAL -->
+	<tag></tag>
+	<item><c>{'$socket', socket(), select, SelectRef}</c></item>
+      </taglist>
+      <p>The caller can now make another
+      call to the recv function and now expect data.</p>
+      <p>Note that all other users are <em>locked out</em> until the
+      'current user' has called the function (recv in this case).</p>
+      <p>Another message the user must be prepared for (when making asynchronous
+      calls) is the <c>abort</c> message:</p>
+      <taglist>
+	<!-- NOTE THAT THE EMPTY TAG IS INTENTIONAL -->
+	<tag></tag>
+	<item><c>{'$socket', socket(), abort, Info}</c></item>
+      </taglist>
+      <p>This message indicates
+      that the (asynchronous) operation has been aborted.
+      If, for instance, the socket has been closed (by another process),
+      <c>Info</c> will be <c>{SelectRef, closed}</c>. </p>
+    </note>
+    <note>
+      <p>There is currently <em>no</em> support for Windows. </p>
+      <p>Support for IPv6 has been implemented but <em>not</em> tested. </p>
+      <p>SCTP has only been partly implemented (and not tested). </p>
+    </note>
+  </description>
+
+  <datatypes>
+    <datatype>
+      <name name="domain"/>
+    </datatype>
+    <datatype>
+      <name name="type"/>
+    </datatype>
+    <datatype>
+      <name name="protocol"/>
+    </datatype>
+    <datatype>
+      <name>socket()</name>
+      <desc><p>As returned by
+        <seealso marker="#open/2"><c>open/2,3,4</c></seealso> and
+        <seealso marker="#accept/1"><c>accept/1,2</c></seealso>.</p>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="select_tag"/>
+      <desc>
+	<p>A tag that describes the (select) operation.</p>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="select_ref"/>
+      <desc>
+	<p>A reference that uniquely identifies the (select) operation.</p>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="select_info"/>
+    </datatype>
+    <datatype>
+      <name name="socket_counters"/>
+    </datatype>
+    <datatype>
+      <name name="socket_counter"/>
+    </datatype>
+    <datatype>
+      <name name="socket_info"/>
+    </datatype>
+    <datatype>
+      <name name="ip4_address"/>
+    </datatype>
+    <datatype>
+      <name name="ip6_address"/>
+    </datatype>
+    <datatype>
+      <name name="ip_address"/>
+    </datatype>
+    <datatype>
+      <name name="sockaddr"/>
+    </datatype>
+    <datatype>
+      <name name="sockaddr_in4"/>
+    </datatype>
+    <datatype>
+      <name name="sockaddr_in6"/>
+    </datatype>
+    <datatype>
+      <name name="sockaddr_un"/>
+    </datatype>
+    <datatype>
+      <name name="port_number"/>
+    </datatype>
+    <datatype>
+      <name name="in6_flow_info"/>
+    </datatype>
+    <datatype>
+      <name name="in6_scope_id"/>
+    </datatype>
+    <datatype>
+      <name name="accept_flags"/>
+    </datatype>
+    <datatype>
+      <name name="accept_flag"/>
+    </datatype>
+    <datatype>
+      <name name="send_flags"/>
+    </datatype>
+    <datatype>
+      <name name="send_flag"/>
+    </datatype>
+    <datatype>
+      <name name="recv_flags"/>
+    </datatype>
+    <datatype>
+      <name name="recv_flag"/>
+    </datatype>
+    <datatype>
+      <name name="shutdown_how"/>
+    </datatype>
+    <datatype>
+      <name name="sockopt_level"/>
+    </datatype>
+    <datatype>
+      <name name="otp_socket_option"/>
+    </datatype>
+    <datatype>
+      <name name="socket_option"/>
+    </datatype>
+    <datatype>
+      <name name="ip_socket_option"/>
+    </datatype>
+    <datatype>
+      <name name="ipv6_socket_option"/>
+    </datatype>
+    <datatype>
+      <name name="tcp_socket_option"/>
+    </datatype>
+    <datatype>
+      <name name="udp_socket_option"/>
+    </datatype>
+    <datatype>
+      <name name="sctp_socket_option"/>
+    </datatype>
+    <datatype>
+      <name name="timeval"/>
+    </datatype>
+    <datatype>
+      <name name="ip_tos"/>
+    </datatype>
+    <datatype>
+      <name name="ip_mreq"/>
+    </datatype>
+    <datatype>
+      <name name="ip_mreq_source"/>
+    </datatype>
+    <datatype>
+      <name name="ip_pmtudisc"/>
+    </datatype>
+    <datatype>
+      <name name="ip_msfilter_mode"/>
+    </datatype>
+    <datatype>
+      <name name="ip_msfilter"/>
+    </datatype>
+    <datatype>
+      <name name="ip_pktinfo"/>
+    </datatype>
+    <datatype>
+      <name name="ipv6_mreq"/>
+    </datatype>
+    <datatype>
+      <name name="ipv6_pmtudisc"/>
+    </datatype>
+    <datatype>
+      <name name="ipv6_pktinfo"/>
+    </datatype>
+    <datatype>
+      <name name="sctp_assoc_id"/>
+    </datatype>
+    <datatype>
+      <name name="sctp_sndrcvinfo"/>
+    </datatype>
+    <datatype>
+      <name name="sctp_event_subscribe"/>
+    </datatype>
+    <datatype>
+      <name name="sctp_assocparams"/>
+    </datatype>
+    <datatype>
+      <name name="sctp_initmsg"/>
+    </datatype>
+    <datatype>
+      <name name="sctp_rtoinfo"/>
+    </datatype>
+    <datatype>
+      <name name="msghdr_flag"/>
+    </datatype>
+    <datatype>
+      <name name="msghdr_flags"/>
+    </datatype>
+    <datatype>
+      <name name="msghdr"/>
+    </datatype>
+    <datatype>
+      <name name="cmsghdr_level"/>
+    </datatype>
+    <datatype>
+      <name name="cmsghdr_type"/>
+    </datatype>
+    <!--
+    <datatype>
+      <name name="cmsghdr_data"/>
+    </datatype>
+    -->
+    <datatype>
+      <name name="cmsghdr_recv"/>
+    </datatype>
+    <datatype>
+      <name name="cmsghdr_send"/>
+    </datatype>
+    <datatype>
+      <name name="uint8"/>
+    </datatype>
+    <datatype>
+      <name name="uint16"/>
+    </datatype>
+    <datatype>
+      <name name="uint20"/>
+    </datatype>
+    <datatype>
+      <name name="uint32"/>
+    </datatype>
+    <datatype>
+      <name name="int32"/>
+    </datatype>
+    <datatype>
+      <name name="supports_options_socket"/>
+    </datatype>
+    <datatype>
+      <name name="supports_options_ip"/>
+    </datatype>
+    <datatype>
+      <name name="supports_options_ipv6"/>
+    </datatype>
+    <datatype>
+      <name name="supports_options_tcp"/>
+    </datatype>
+    <datatype>
+      <name name="supports_options_udp"/>
+    </datatype>
+    <datatype>
+      <name name="supports_options_sctp"/>
+    </datatype>
+    <datatype>
+      <name name="supports_options"/>
+    </datatype>
+  </datatypes>
+
+  <funcs>
+    <func>
+      <name name="accept" arity="1" since="OTP 22.0"/>
+      <name name="accept" arity="2" clause_i="2" since="OTP 22.0"/>
+      <fsummary>Accept a connection on a socket.</fsummary>
+      <desc>
+        <p>Accept a connection on a socket.</p>
+        <p>This call is used with connection-based socket types
+	(<c>stream</c> or <c>seqpacket</c>). It extracs the first pending
+	connection request for the listen socket and returns the (newly)
+	connected socket.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="accept" arity="2" clause_i="1" anchor="accept_async" since="OTP @OTP-15731@"/>
+      <fsummary>Accept a connection on a socket.</fsummary>
+      <desc>
+        <p>Accept a connection on a socket.</p>
+
+	<p>This call is used with connection-based socket types
+	(<c>stream</c> or <c>seqpacket</c>). It extracs the first pending
+	connection request for the listen socket and returns the (newly)
+	connected socket.</p>
+
+	<p>In the case when there is no connections waiting, the function 
+	will return with the <c>SelectInfo</c>. The caller can then await a 
+	select message, <c>{'$socket', Socket, select, Info}</c> (where
+	<c>Info</c> is the
+	<seealso marker="socket#type-select_ref"><c>ref</c></seealso>
+	field from the <c>SelectInfo</c>),
+	when a client connects (a subsequent call to accept will then return 
+	the socket). </p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="bind" arity="2" since="OTP 22.0"/>
+      <fsummary>Bind a name to a socket.</fsummary>
+      <desc>
+        <p>Bind a name to a socket.</p>
+        <p>When a socket is created
+	(with <seealso marker="#open/2"><c>open</c></seealso>),
+	it has no address assigned to it. <c>bind</c> assigns the
+	address specified by the <c>Addr</c> argument.</p>
+	<p>The rules used for name binding vary between domains.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="cancel" arity="2" since="OTP @OTP-15731@"/>
+      <fsummary>Cancel an asynchronous request.</fsummary>
+      <desc>
+	<p>Cancel an asynchronous request.</p>
+
+	<p>Call this function in order to cancel a previous
+	asynchronous call to, e.g.
+	<seealso marker="#recv/3"><c>recv/3</c></seealso>. </p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="close" arity="1" since="OTP 22.0"/>
+      <fsummary>Close a socket.</fsummary>
+      <desc>
+	<p>Closes the socket.</p>
+
+	<note>
+	  <p>Note that for e.g. <c>protocol</c> = <c>tcp</c>, most implementations
+	  doing a close does not guarantee that any data sent is delivered to
+	  the recipient before the close is detected at the remote side. </p>
+	  <p>One way to handle this is to use the
+	  <seealso marker="#shutdown/2"><c>shutdown</c></seealso>
+	  function
+	  (<c>socket:shutdown(Socket, write)</c>) to signal that no more data is
+	  to be sent and then wait for the read side of the socket to be closed.</p>
+	</note>
+      </desc>
+    </func>
+
+    <func>
+      <name name="connect" arity="2" since="OTP 22.0"/>
+      <name name="connect" arity="3" clause_i="2" since="OTP 22.0"/>
+      <fsummary>Initiate a connection on a socket.</fsummary>
+      <desc>
+        <p>This function connects the socket to the address
+	specied by the <c>SockAddr</c> argument.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="connect" arity="3" clause_i="1" anchor="connect_async" since="OTP @OTP-15731@"/>
+      <fsummary>Initiate a connection on a socket.</fsummary>
+      <desc>
+        <p>This function connects the socket to the address
+	specied by the <c>SockAddr</c> argument.</p>
+
+ 	<p>In the case when its not possible to immediately establish a
+	connection, the function will return with the
+	<seealso marker="#type-select_info"><c>SelectInfo</c></seealso>.
+	The caller can then await a 
+	select message, <c>{'$socket', Socket, select, Info}</c> (where
+	<c>Info</c> is the
+	<seealso marker="socket#type-select_ref"><c>ref</c></seealso>
+	field from the <c>SelectInfo</c>,
+	a subsequent call to connect will then 
+	establish the connection). </p>
+     </desc>
+    </func>
+
+    <func>
+      <name name="getopt" arity="3" clause_i="1" since="OTP 22.0"/>
+      <name name="getopt" arity="3" clause_i="2" since="OTP 22.0"/>
+      <name name="getopt" arity="3" clause_i="3" since="OTP 22.0"/>
+      <name name="getopt" arity="3" clause_i="4" since="OTP 22.0"/>
+      <name name="getopt" arity="3" clause_i="5" since="OTP 22.0"/>
+      <name name="getopt" arity="3" clause_i="6" since="OTP 22.0"/>
+      <name name="getopt" arity="3" clause_i="7" since="OTP 22.0"/>
+      <fsummary>Get an option on a socket.</fsummary>
+      <desc>
+        <p>Get an option on a socket.</p>
+	<p>What properties are valid depend  both on <c>Level</c> and
+	on what kind of socket it is (<c>domain</c>, <c>type</c> and
+	<c>protocol</c>).</p>
+
+	<p>See the
+	<seealso marker="socket_usage#socket_options">socket options</seealso>
+	chapter of the users guide for more info. </p>
+
+	<note><p>Not all options are valid on all platforms. That is,
+	even if "we" support an option, that does not mean that the
+	underlying OS does.</p></note>
+
+      </desc>
+    </func>
+
+    <func>
+      <name name="getopt" arity="3" clause_i="8" since="OTP 22.0"/>
+      <fsummary>Get an option on a socket.</fsummary>
+      <desc>
+        <p>Get an option on a socket.</p>
+	<p>What properties are valid depend  both on <c>Level</c> and
+	on what kind of socket it is (<c>domain</c>, <c>type</c> and
+	<c>protocol</c>).</p>
+	<p>When specifying <c>Level</c> as an integer, and therefor
+	using "native mode", it is *currently* up to the caller to
+	know how to interpret the result.</p>
+
+	<p>See the
+	<seealso marker="socket_usage#socket_options">socket options</seealso>
+	chapter of the users guide for more info. </p>
+
+	<note><p>Not all options are valid on all platforms. That is,
+	even if "we" support an option, that does not mean that the
+	underlying OS does.</p></note>
+      </desc>
+    </func>
+
+    <func>
+      <name name="info" arity="1" since="OTP @OTP-15818@"/>
+      <fsummary>Get miscellaneous socket info.</fsummary>
+      <desc>
+        <p>Get miscellaneous info about the socket.</p>
+	<p>The function returns a map with each info item as a key-value
+	binding. It reflects the "current" state of the socket. </p>
+	<note>
+	  <p>In order to ensure data integrity, mutex'es are taken when
+	  needed. So, do not call this function often. </p>
+	</note>
+      </desc>
+    </func>
+
+    <func>
+      <name name="listen" arity="1" since="OTP 22.0"/>
+      <name name="listen" arity="2" since="OTP 22.0"/>
+      <fsummary>Listen for connections on a socket.</fsummary>
+      <desc>
+        <p>Listen for connections on a socket.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="open" arity="2" since="OTP 22.0"/>
+      <name name="open" arity="3" since="OTP 22.0"/>
+      <name name="open" arity="4" since="OTP 22.0"/>
+      <fsummary>Create an endpoint for communication.</fsummary>
+      <desc>
+	<p>Creates an endpoint (socket) for communication.</p>
+
+	<p>For some <c>types</c> there is a default protocol,
+	indicated by <c>default</c>, which it <em>may</em> be
+	possible to specify.
+	And for <c>Domain = local</c>, if a protocol <em>is</em> pecified,
+	it <em>must</em> be <c>default</c>. </p>
+
+	<p>The <c>Extra</c> argument is intended for "obscure" options.
+	Currently the only supported option is <c>netns</c>, which
+	is only supported on the linux platform.</p>
+
+	<note>
+	  <p>It may not be possible to specify the default protocol (except
+	  when <c>Domain = local</c>). We need to be able to retreive
+	  the resulting protocol, which is <em>not</em> possble on all
+	  platforms. </p>
+	</note>
+      </desc>
+    </func>
+
+    <func>
+      <name name="peername" arity="1" since="OTP 22.0"/>
+      <fsummary>Get name of connected socket peer.</fsummary>
+      <desc>
+        <p>Returns the address of the peer connected to the socket.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="recv" arity="1" since="OTP 22.0"/>
+      <name name="recv" arity="2" since="OTP 22.0"/>
+      <name name="recv" arity="3" clause_i="1" since="OTP 22.0"/>
+      <name name="recv" arity="3" clause_i="3" since="OTP 22.0"/>
+      <name name="recv" arity="4" clause_i="2" since="OTP 22.0"/>
+      <fsummary>Receive a message from a socket.</fsummary>
+      <desc>
+        <p>Receive a message from a socket.</p>
+	<p>There is a special case for the argument <c>Length</c>.
+	If it is set to zero (0), it means "give me everything you 
+	currently have".</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="recv" arity="3" clause_i="2" anchor="recv_async" since="OTP @OTP-15731@"/>
+      <name name="recv" arity="4" clause_i="1" since="OTP @OTP-15731@"/>
+      <fsummary>Receive a message from a socket.</fsummary>
+      <desc>
+        <p>Receive a message from a socket.</p>
+
+	<p>There is a special case for the argument <c>Length</c>.
+	If it is set to zero (0), it means "give me everything you 
+	currently have".</p>
+
+	<p>In the case when there is no data waiting, the function 
+	will return with the <c>SelectInfo</c>. The caller can then await a 
+	select message, <c>{'$socket', Socket, select, Info}</c> (where
+	<c>Info</c> is the
+	<seealso marker="socket#type-select_ref"><c>ref</c></seealso>
+	field from the <c>SelectInfo</c>),
+	when data has arrived (a subsequent call to recv will then return 
+	the data). </p>
+	<p>Note that if a length (<c>> 0</c>) is specified, and only part
+	of that amount of data is available, the function will return with
+	that data <em>and</em> the <c>SelectInfo</c> (if the caller don't 
+	want to wait for the remaining data, it must immediately call
+	the <seealso marker="#cancel/2"><c>cancel/2</c></seealso> function.)</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="recvfrom" arity="1" since="OTP 22.0"/>
+      <name name="recvfrom" arity="2" since="OTP 22.0"/>
+      <name name="recvfrom" arity="3" clause_i="2" since="OTP 22.0"/>
+      <name name="recvfrom" arity="3" clause_i="3" since="OTP 22.0"/>
+      <name name="recvfrom" arity="3" clause_i="5" since="OTP 22.0"/>
+      <name name="recvfrom" arity="4" clause_i="2" since="OTP 22.0"/>
+      <fsummary>Receive a message from a socket.</fsummary>
+      <desc>
+        <p>Receive a message from a socket.</p>
+        <p>This function reads "messages", which means that regardless of
+	how much we want to read, it returns when we get a message
+	(if the buffer size is to small, the message will be truncated).</p>
+        <p>The <c>BufSz</c> argument basically defines the size of the
+	receive buffer. By setting the value to zero (0), the configured
+	size (setopt with <c>Level</c> = <c>otp</c> and
+	<c>Key</c> = <c>rcvbuf</c>) is used.</p>
+        <p>It may be impossible to know what (buffer) size is appropriate
+	"in advance", and in those cases it may be convenient to use the
+	(recv) 'peek' flag. When this flag is provided, the message is *not*
+	"consumed" from the underlying buffers, so another recvfrom call
+	is needed, possibly with a then adjusted buffer size.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="recvfrom" arity="3" clause_i="1" anchor="recvfrom_async" since="OTP @OTP-15731@"/>
+      <name name="recvfrom" arity="3" clause_i="4" since="OTP @OTP-15731@"/>
+      <name name="recvfrom" arity="4" clause_i="1" since="OTP @OTP-15731@"/>
+      <fsummary>Receive a message from a socket.</fsummary>
+      <desc>
+        <p>Receive a message from a socket.</p>
+        <p>This function reads "messages", which means that regardless of
+	how much we want to read, it returns when we get a message
+	(if the buffer size is to small, the message will be truncated).</p>
+        <p>The <c>BufSz</c> argument basically defines the size of the
+	receive buffer. By setting the value to zero (0), the configured
+	size (setopt with <c>Level</c> = <c>otp</c> and
+	<c>Key</c> = <c>rcvbuf</c>) is used.</p>
+        <p>It may be impossible to know what (buffer) size is appropriate
+	"in advance", and in those cases it may be convenient to use the
+	(recv) 'peek' flag. When this flag is provided, the message is *not*
+	"consumed" from the underlying buffers, so another recvfrom call
+	is needed, possibly with a then adjusted buffer size.</p>
+
+	<p>In the case when there is no data waiting, the function 
+	will return with the <c>SelectInfo</c>. The caller can then await a 
+	select message, <c>{'$socket', Socket, select, Info}</c> (where
+	<c>Info</c> is the
+	<seealso marker="socket#type-select_ref"><c>ref</c></seealso>
+	field from the <c>SelectInfo</c>),
+	when data has arrived (a subsequent call to recvfrom will then return 
+	the data). </p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="recvmsg" arity="1" since="OTP 22.0"/>
+      <name name="recvmsg" arity="2" clause_i="1" since="OTP 22.0"/>
+      <name name="recvmsg" arity="2" clause_i="3" since="OTP 22.0"/>
+      <name name="recvmsg" arity="3" clause_i="2" since="OTP 22.0"/>
+      <name name="recvmsg" arity="3" clause_i="3" since="OTP 22.0"/>
+      <name name="recvmsg" arity="5" clause_i="2" since="OTP 22.0"/>
+      <fsummary>Receive a message from a socket.</fsummary>
+      <desc>
+        <p>Receive a message from a socket.</p>
+        <p>This function reads "messages", which means that regardless of
+	how much we want to read, it returns when we get a message.</p>
+	<p>The message will be delivered in the form of a <c>msghdr()</c>,
+	which may contain the source address (if socket not connected),
+	a list of <c>cmsghdr_recv()</c> (depends on what socket options have
+	been set and what the protocol and platform supports) and
+	also a set of flags, providing further info about the read. </p>
+	
+        <p>The <c>BufSz</c> argument basically defines the size of the
+	receive buffer. By setting the value to zero (0), the configured
+	size (setopt with <c>Level</c> = <c>otp</c> and
+	<c>Key</c> = <c>rcvbuf</c>) is used.</p>
+
+        <p>The <c>CtrlSz</c> argument basically defines the size of the
+	receive buffer for the control messages.
+	By setting the value to zero (0), the configured size (setopt
+	with <c>Level</c> = <c>otp</c>) is used.</p>
+
+	<p>It may be impossible to know what (buffer) size is appropriate
+	"in advance", and in those cases it may be convenient to use the
+	(recv) 'peek' flag. When this flag is provided, the message is *not*
+	"consumed" from the underlying buffers, so another recvmsg call
+	is needed, possibly with a then adjusted buffer size.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="recvmsg" arity="2" clause_i="2" anchor="recvmsg_async" since="OTP @OTP-15731@"/>
+      <name name="recvmsg" arity="3" clause_i="1" since="OTP @OTP-15731@"/>
+      <name name="recvmsg" arity="5" clause_i="1" since="OTP @OTP-15731@"/>
+      <fsummary>Receive a message from a socket.</fsummary>
+      <desc>
+        <p>Receive a message from a socket.</p>
+        <p>This function reads "messages", which means that regardless of
+	how much we want to read, it returns when we get a message.</p>
+	<p>The message will be delivered in the form of a <c>msghdr()</c>,
+	which may contain the source address (if socket not connected),
+	a list of <c>cmsghdr_recv()</c> (depends on what socket options have
+	been set and what the protocol and platform supports) and
+	also a set of flags, providing further info about the read. </p>
+	
+        <p>The <c>BufSz</c> argument basically defines the size of the
+	receive buffer. By setting the value to zero (0), the configured
+	size (setopt with <c>Level</c> = <c>otp</c> and
+	<c>Key</c> = <c>rcvbuf</c>) is used.</p>
+
+        <p>The <c>CtrlSz</c> argument basically defines the size of the
+	receive buffer for the control messages.
+	By setting the value to zero (0), the configured size (setopt
+	with <c>Level</c> = <c>otp</c>) is used.</p>
+
+	<p>It may be impossible to know what (buffer) size is appropriate
+	"in advance", and in those cases it may be convenient to use the
+	(recv) 'peek' flag. When this flag is provided, the message is *not*
+	"consumed" from the underlying buffers, so another recvmsg call
+	is needed, possibly with a then adjusted buffer size.</p>
+
+	<p>In the case when there is no data waiting, the function 
+	will return with the <c>SelectInfo</c>. The caller can then await a 
+	select message, <c>{'$socket', Socket, select, Info}</c> (where
+	<c>Info</c> is the
+	<seealso marker="socket#type-select_ref"><c>ref</c></seealso>
+	field from the <c>SelectInfo</c>),
+	when data has arrived (a subsequent call to recvmsg will then return 
+	the data). </p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="send" arity="2" since="OTP 22.0"/>
+      <name name="send" arity="3" clause_i="1" since="OTP 22.0"/>
+      <name name="send" arity="3" clause_i="3" since="OTP 22.0"/>
+      <name name="send" arity="4" clause_i="2" since="OTP 22.0"/>
+      <fsummary>Send a message on a socket.</fsummary>
+      <desc>
+        <p>Send a message on a connected socket.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="send" arity="3" clause_i="2" anchor="send_async" since="OTP @OTP-15731@"/>
+      <name name="send" arity="4" clause_i="1" since="OTP @OTP-15731@"/>
+      <fsummary>Send a message on a socket.</fsummary>
+      <desc>
+        <p>Send a message on a connected socket.</p>
+
+	<p>In the case when there is no room in the (system-) buffers,
+	the function will return with the <c>SelectInfo</c>. The caller
+	can then await a select message,
+	<c>{'$socket', Socket, select, Info}</c>
+	(where <c>Info</c> is the
+	<seealso marker="socket#type-select_ref"><c>ref</c></seealso>
+	field from the
+	<c>SelectInfo</c>), when there is room for more data (a subsequent
+	call to send will then send the data). </p>
+	<p>Note that if not all the data was sent, the function will return
+	with the remaining data <em>and</em> the <c>SelectInfo</c>
+	(if the caller don't 
+	want to wait to be able to send the rest, it should immediately call
+	the <seealso marker="#cancel/2"><c>cancel/2</c></seealso> function.)</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="sendmsg" arity="2" since="OTP 22.0"/>
+      <name name="sendmsg" arity="3" clause_i="1" since="OTP 22.0"/>
+      <name name="sendmsg" arity="3" clause_i="3" since="OTP 22.0"/>
+      <name name="sendmsg" arity="4" clause_i="2" since="OTP 22.0"/>
+      <fsummary>Send a message on a socket.</fsummary>
+      <desc>
+	<p>Send a message on a socket. The destination, if needed
+	(socket <em>not</em> connected) is provided in the <c>MsgHdr</c>,
+	which also contains the message to send,
+	The <c>MsgHdr</c> may also contain an list of optional <c>cmsghdr_send()</c>
+	(depends on what the protocol and platform supports).</p>
+
+	<p>Unlike the <seealso marker="#send/2"><c>send</c></seealso> function,
+	this one sends <em>one message</em>.
+	This means that if, for whatever reason, its not possible to send the
+	message in one go, the function will instead return with the
+	<em>remaining</em> data (<c>{ok, Remaining}</c>). Thereby leaving it
+	up to the caller to decide what to do (retry with the remaining data
+	of give up). </p>
+
+      </desc>
+    </func>
+
+    <func>
+      <name name="sendmsg" arity="3" clause_i="2" anchor="sendmsg_async" since="OTP @OTP-15731@"/>
+      <name name="sendmsg" arity="4" clause_i="1" since="OTP @OTP-15731@"/>
+      <fsummary>Send a message on a socket.</fsummary>
+      <desc>
+	<p>Send a message on a socket. The destination, if needed
+	(socket <em>not</em> connected) is provided in the <c>MsgHdr</c>,
+	which also contains the message to send,
+	The <c>MsgHdr</c> may also contain an list of optional <c>cmsghdr_send()</c>
+	(depends on what the protocol and platform supports).</p>
+
+	<p>Unlike the <seealso marker="#send/2"><c>send</c></seealso> function,
+	this one sends <em>one message</em>.
+	This means that if, for whatever reason, its not possible to send the
+	message in one go, the function will instead return with the
+	<em>remaining</em> data (<c>{ok, Remaining}</c>). Thereby leaving it
+	up to the caller to decide what to do (retry with the remaining data
+	of give up). </p>
+
+	<p>In the case when there is no room in the (system-) buffers,
+	the function will return with the <c>SelectInfo</c>. The caller
+	can then await a select message,
+	<c>{'$socket', Socket, select, Info}</c>
+	(where <c>Info</c> is the
+	<seealso marker="socket#type-select_ref"><c>ref</c></seealso>
+	field from the
+	<c>SelectInfo</c>), when there is room for more data (a subsequent
+	call to sendmsg will then send the data). </p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="sendto" arity="3" since="OTP 22.0"/>
+      <name name="sendto" arity="4" clause_i="1" since="OTP 22.0"/>
+      <name name="sendto" arity="4" clause_i="3" since="OTP 22.0"/>
+      <name name="sendto" arity="5" clause_i="2" since="OTP 22.0"/>
+      <fsummary>Send a message on a socket.</fsummary>
+      <desc>
+        <p>Send a message on a socket, to the specified destination.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="sendto" arity="4" clause_i="2" anchor="sendto_async" since="OTP @OTP-15731@"/>
+      <name name="sendto" arity="5" clause_i="1" since="OTP @OTP-15731@"/>
+      <fsummary>Send a message on a socket.</fsummary>
+      <desc>
+        <p>Send a message on a socket, to the specified destination.</p>
+
+	<p>In the case when there is no room in the (system-) buffers,
+	the function will return with the <c>SelectInfo</c>. The caller
+	can then await a select message,
+	<c>{'$socket', Socket, select, Info}</c>
+	(where <c>Info</c> is the
+	<seealso marker="socket#type-select_ref"><c>ref</c></seealso>
+	field from the
+	<c>SelectInfo</c>), when there is room for more data (a subsequent
+	call to sendto will then send the data). </p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="setopt" arity="4" clause_i="1" since="OTP 22.0"/>
+      <name name="setopt" arity="4" clause_i="2" since="OTP 22.0"/>
+      <name name="setopt" arity="4" clause_i="3" since="OTP 22.0"/>
+      <name name="setopt" arity="4" clause_i="4" since="OTP 22.0"/>
+      <name name="setopt" arity="4" clause_i="5" since="OTP 22.0"/>
+      <name name="setopt" arity="4" clause_i="6" since="OTP 22.0"/>
+      <name name="setopt" arity="4" clause_i="7" since="OTP 22.0"/>
+      <fsummary>Set options on a socket.</fsummary>
+      <desc>
+        <p>Set options on a socket.</p>
+	<p>What properties are valid depend both on <c>Level</c> and on
+	what kind of socket it is (<c>domain</c>, <c>type</c> and
+	<c>protocol</c>).</p>
+
+	<p>See the
+	<seealso marker="socket_usage#socket_options">socket options</seealso>
+	chapter of the users guide for more info. </p>
+
+	<note><p>Not all options are valid on all platforms. That is,
+	even if "we" support an option, that does not mean that the
+	underlying OS does.</p></note>
+
+	<note><p>Sockets are set 'non-blocking' when created, so this option
+	is *not* available (as it would adversely effect the Erlang VM
+	to set a socket 'blocking').</p></note>
+      </desc>
+    </func>
+
+    <func>
+      <name name="setopt" arity="4" clause_i="8" since="OTP 22.0"/>
+      <fsummary>Set options on a socket.</fsummary>
+      <desc>
+        <p>Set options on a socket.</p>
+	<p>What properties are valid depend both on <c>Level</c> and on
+	what kind of socket it is (<c>domain</c>, <c>type</c> and
+	<c>protocol</c>).</p>
+
+	<p>See the
+	<seealso marker="socket_usage#socket_options">socket options</seealso>
+	chapter of the users guide for more info. </p>
+
+	<note><p>Not all options are valid on all platforms. That is,
+	even if "we" support an option, that does not mean that the
+	underlying OS does.</p></note>
+
+	<note><p>Sockets are set 'non-blocking' when created, so this option
+	is *not* available (as it would adversely effect the Erlang VM
+	to set a socket 'blocking').</p></note>
+      </desc>
+    </func>
+
+    <func>
+      <name name="shutdown" arity="2" since="OTP 22.0"/>
+      <fsummary>Shut down part of a full-duplex connection.</fsummary>
+      <desc>
+        <p>Shut down all or part of a full-duplex connection.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="sockname" arity="1" since="OTP 22.0"/>
+      <fsummary>Get socket name.</fsummary>
+      <desc>
+        <p>Returns the current address to which the socket is bound.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="supports" arity="0" since="OTP 22.0"/>
+      <name name="supports" arity="1" clause_i="1" since="OTP 22.0"/>
+      <name name="supports" arity="1" clause_i="2" since="OTP 22.0"/>
+      <name name="supports" arity="1" clause_i="3" since="OTP 22.0"/>
+      <name name="supports" arity="1" clause_i="4" since="OTP 22.0"/>
+      <name name="supports" arity="2" clause_i="1" since="OTP 22.0"/>
+      <name name="supports" arity="2" clause_i="2" since="OTP 22.0"/>
+      <name name="supports" arity="2" clause_i="3" since="OTP 22.0"/>
+      <name name="supports" arity="2" clause_i="4" since="OTP 22.0"/>
+      <name name="supports" arity="2" clause_i="5" since="OTP 22.0"/>
+      <name name="supports" arity="2" clause_i="6" since="OTP 22.0"/>
+      <name name="supports" arity="2" clause_i="7" since="OTP 22.0"/>
+      <name name="supports" arity="3" clause_i="1" since="OTP 22.0"/>
+      <name name="supports" arity="3" clause_i="2" since="OTP 22.0"/>
+      <name name="supports" arity="3" clause_i="3" since="OTP 22.0"/>
+      <name name="supports" arity="3" clause_i="4" since="OTP 22.0"/>
+      <name name="supports" arity="3" clause_i="5" since="OTP 22.0"/>
+      <name name="supports" arity="3" clause_i="6" since="OTP 22.0"/>
+      <name name="supports" arity="3" clause_i="7" since="OTP 22.0"/>
+      <fsummary>Report info about what the platform supports.</fsummary>
+      <desc>
+	<p>This function intends to retreive information about what the
+	platform supports. Such as if SCTP is supported. Or which socket
+	options are supported. </p>
+      </desc>
+    </func>
+
+  </funcs>
+  <section>
+    <title>Examples</title>
+    <marker id="examples"></marker>
+    <code type="none">
+client(Addr, SAddr, SPort) ->
+   {ok, Sock} = socket:open(inet, stream, tcp),
+   {ok, _} = socket:bind(Sock, #{family => inet,
+                                 addr   => Addr}),
+   ok = socket:connect(Sock, #{family => inet,
+                               addr   => SAddr,
+			       port   => SPort}),
+   Msg = list_to_binary("hello"),
+   ok = socket:send(Sock, Msg),
+   ok = socket:shutdown(Sock, write),
+   {ok, Msg} = socket:recv(Sock),
+   ok = socket:close(Sock).
+
+server(Addr, Port) ->  
+   {ok, LSock} = socket:open(inet, stream, tcp),
+   {ok, _} = socket:bind(LSock, #{family => inet,
+                                  port   => Port,
+		 	          addr   => Addr}),
+   ok = socket:listen(LSock),
+   {ok, Sock} = socket:accept(LSock),
+   {ok, Msg} = socket:recv(Sock),
+   ok = socket:send(Sock, Msg),
+   ok = socket:shutdown(Sock, write),
+   ok = socket:close(Sock),
+   ok = socket:close(LSock).
+    </code>
+  </section>
+</erlref>
+
diff --git a/erts/doc/src/socket_usage.xml b/erts/doc/src/socket_usage.xml
new file mode 100644
index 0000000000..c3cda9a615
--- /dev/null
+++ b/erts/doc/src/socket_usage.xml
@@ -0,0 +1,845 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE chapter SYSTEM "chapter.dtd">
+
+<chapter>
+  <header>
+    <copyright>
+      <year>2018</year><year>2019</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      Licensed under the Apache License, Version 2.0 (the "License");
+      you may not use this file except in compliance with the License.
+      You may obtain a copy of the License at
+ 
+          http://www.apache.org/licenses/LICENSE-2.0
+
+      Unless required by applicable law or agreed to in writing, software
+      distributed under the License is distributed on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+      See the License for the specific language governing permissions and
+      limitations under the License.
+
+    </legalnotice>
+
+    <title>Socket Usage</title>
+    <prepared>Micael Karlberg</prepared>
+    <docno></docno>
+    <date>2018-07-17</date>
+    <rev>PA1</rev>
+    <file>socket_usage.xml</file>
+  </header>
+
+  <section>
+    <title>Introduction</title>
+    <p>The socket interface (module) is basically an "thin" layer on top of
+    the OS socket interface. It is assumed that, unless you have special needs,
+    gen_[tcp|udp|sctp] should be sufficent (when they become available). </p>
+    <p>Note that just because we have a documented and described option,
+    it does <em>not</em> mean that the OS supports it. So its recommended
+    that the user reads the platform specific documentation for the
+    option used. </p>
+    <section>
+      <title>Asynchronous calls</title>
+      <p>Some functions allow for an <i>asynchronous</i> call
+      (<seealso marker="socket#accept_async"><c>accept/2</c></seealso>,
+      <seealso marker="socket#connect_async"><c>connect/3</c></seealso>,
+      <seealso marker="socket#recv_async"><c>recv/3,4</c></seealso>,
+      <seealso marker="socket#recvfrom_async"><c>recvfrom/3,4</c></seealso>,
+      <seealso marker="socket#recvmsg_async"><c>recvmsg/2,3,5</c></seealso>,
+      <seealso marker="socket#send_async"><c>send/3,4</c></seealso>,
+      <seealso marker="socket#sendmsg_async"><c>sendmsg/3,4</c></seealso> and
+      <seealso marker="socket#sendto_async"><c>sendto/4,5</c></seealso>).
+      This is achieved by setting the <c>Timeout</c> argument to
+      <c>nowait</c>. For instance, if calling the
+      <seealso marker="socket#recv_async"><c>recv/3</c></seealso>
+      function with Timeout set to <c>nowait</c> (i.e. 
+      <c>recv(Sock, 0, nowait)</c>)
+      when there is actually nothing to read, it will return with
+      <c>{select, </c>
+      <seealso marker="socket#type-select_info"><c>SelectInfo</c></seealso><c>}</c>
+      (<c>SelectInfo</c> contains the
+      <seealso marker="socket#type-select_ref">SelectRef</seealso>).
+      When data eventually arrives a 'select message'
+      will be sent to the caller:</p>
+      <taglist>
+	<!-- NOTE THAT THE EMPTY TAG IS INTENTIONAL -->
+	<tag></tag>
+	<item><c>{'$socket', socket(), select, SelectRef}</c></item>
+      </taglist>
+      <p>The caller can then make another
+      call to the recv function and now expect data.</p>
+      <p>The user must also be prepared to receive an abort message: </p>
+      <taglist>
+	<!-- NOTE THAT THE EMPTY TAG IS INTENTIONAL -->
+	<tag></tag>
+	<item><c>{'$socket', socket(), abort, Info}</c></item>
+      </taglist>
+      <p>If the operation is aborted
+      for whatever reason (e.g. if the socket is closed "by someone else").
+      The <c>Info</c> part contains the abort reason (in this case that
+      the socket has been closed <c>Info = {SelectRef, closed}</c>). </p>
+      <p>Note that all other users are <em>locked out</em> until the
+      'current user' has called the function (recv in this case). So either
+      immediately call the function or
+      <seealso marker="socket#cancel/2"><c>cancel</c></seealso>. </p>
+
+      <p>The general form of the 'socket' message is: </p>
+      <taglist>
+	<!-- NOTE THAT THE EMPTY TAG IS INTENTIONAL -->
+	<tag></tag>
+	<item><c>{'$socket', Sock :: socket(), Tag :: atom(), Info :: term()}</c></item>
+      </taglist>
+      <p>Where the format of <c>Info</c> is a function of <c>Tag</c>:</p>
+      <table>
+	<row>
+	  <cell><em>Tag</em></cell>
+	  <cell><em>Info value type</em></cell>
+	</row>
+	<row>
+	  <cell>select</cell>
+	  <cell>select_ref()</cell>
+	</row>
+	<row>
+	  <cell>abort</cell>
+	  <cell>{select_ref(), Reason :: term()}</cell>
+	</row>
+	<tcaption>socket message info value type</tcaption>
+      </table>
+      <p>The <c>select_ref()</c> is the same as was received in the
+      <seealso marker="socket#type-select_info"><c>SelectInfo</c></seealso>. </p>
+    </section>
+  </section>
+
+  <section>
+    <marker id="socket_options"></marker>
+    <title>Socket Options</title>
+
+    <p>Options for level <c>otp</c>: </p>
+    <table>
+      <row>
+	<cell><em>Option Name</em></cell>
+	<cell><em>Value Type</em></cell>
+	<cell><em>Set</em></cell>
+	<cell><em>Get</em></cell>
+	<cell><em>Other Requirements and comments</em></cell>
+      </row>
+      <row>
+	<cell>assoc_id</cell>
+	<cell>integer()</cell>
+	<cell>no</cell>
+	<cell>yes</cell>
+	<cell>type = seqpacket, protocol = sctp, is an association</cell>
+      </row>
+      <row>
+	<cell>debug</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>iow</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>controlling_process</cell>
+	<cell>pid()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>rcvbuf</cell>
+	<cell>default | pos_integer() | {pos_integer(), pos_ineteger()}</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>'default' only valid for set.
+	The tuple form is only valid for type 'stream' and protocol 'tcp'.</cell>
+      </row>
+      <row>
+	<cell>rcvctrlbuf</cell>
+	<cell>default | pos_integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>default only valid for set</cell>
+      </row>
+      <row>
+	<cell>sndctrlbuf</cell>
+	<cell>default | pos_integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>default only valid for set</cell>
+      </row>
+      <row>
+	<cell>fd</cell>
+	<cell>integer()</cell>
+	<cell>no</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <tcaption>option levels</tcaption>
+    </table>
+    
+    <p>Options for level <c>socket</c>: </p>
+    <table>
+      <row>
+	<cell><em>Option Name</em></cell>
+	<cell><em>Value Type</em></cell>
+	<cell><em>Set</em></cell>
+	<cell><em>Get</em></cell>
+	<cell><em>Other Requirements and comments</em></cell>
+      </row>
+      <row>
+	<cell>acceptconn</cell>
+	<cell>boolean()</cell>
+	<cell>no</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>bindtodevice</cell>
+	<cell>string()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>Before Linux 3.8, this socket option could be set, but not get.
+	Only works for some socket types (e.g. <c>inet</c>).
+	If empty value is set, the binding is removed.</cell>
+      </row>
+      <row>
+	<cell>broadcast</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram</cell>
+      </row>
+      <row>
+	<cell>debug</cell>
+	<cell>integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>may require admin capability</cell>
+      </row>
+      <row>
+	<cell>domain</cell>
+	<cell>domain()</cell>
+	<cell>no</cell>
+	<cell>yes</cell>
+	<cell><em>Not</em> on FreeBSD (for instance)</cell>
+      </row>
+      <row>
+	<cell>dontroute</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>keepalive</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>linger</cell>
+	<cell>abort | linger()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>oobinline</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>peek_off</cell>
+	<cell>integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>domain = local (unix)</cell>
+      </row>
+      <row>
+	<cell>priority</cell>
+	<cell>integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>protocol</cell>
+	<cell>protocol()</cell>
+	<cell>no</cell>
+	<cell>yes</cell>
+	<cell><em>Not</em> on (some) Darwin (for instance)</cell>
+      </row>
+      <row>
+	<cell>rcvbuf</cell>
+	<cell>non_neg_integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>rcvlowat</cell>
+	<cell>non_neg_integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>rcvtimeo</cell>
+	<cell>timeval()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>reuseaddr</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>reuseport</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>domain = inet | inet6</cell>
+      </row>
+      <row>
+	<cell>sndbuf</cell>
+	<cell>non_neg_integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>sndlowat</cell>
+	<cell>non_neg_integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>not changeable on Linux</cell>
+      </row>
+      <row>
+	<cell>sndtimeo</cell>
+	<cell>timeval()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>timestamp</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>type</cell>
+	<cell>type()</cell>
+	<cell>no</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <tcaption>socket options</tcaption>
+    </table>
+    
+    <p>Options for level <c>ip</c>: </p>
+    <table>
+      <row>
+	<cell><em>Option Name</em></cell>
+	<cell><em>Value Type</em></cell>
+	<cell><em>Set</em></cell>
+	<cell><em>Get</em></cell>
+	<cell><em>Other Requirements and comments</em></cell>
+      </row>
+      <row>
+	<cell>add_membership</cell>
+	<cell>ip_mreq()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>add_source_membership</cell>
+	<cell>ip_mreq_source()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>block_source</cell>
+	<cell>ip_mreq_source()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>drop_membership</cell>
+	<cell>ip_mreq()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>drop_source_membership</cell>
+	<cell>ip_mreq_source()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>freebind</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>hdrincl</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = raw</cell>
+      </row>
+      <row>
+	<cell>minttl</cell>
+	<cell>integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = raw</cell>
+      </row>
+      <row>
+	<cell>msfilter</cell>
+	<cell>null | ip_msfilter()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>mtu</cell>
+	<cell>integer()</cell>
+	<cell>no</cell>
+	<cell>yes</cell>
+	<cell>type = raw</cell>
+      </row>
+      <row>
+	<cell>mtu_discover</cell>
+	<cell>ip_pmtudisc()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>multicast_all</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>multicast_if</cell>
+	<cell>any | ip4_address()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>multicast_loop</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>multicast_ttl</cell>
+	<cell>uint8()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>nodefrag</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = raw</cell>
+      </row>
+      <row>
+	<cell>pktinfo</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram</cell>
+      </row>
+      <row>
+	<cell>recvdstaddr</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram</cell>
+      </row>
+      <row>
+	<cell>recverr</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>recvif</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw</cell>
+      </row>
+      <row>
+	<cell>recvopts</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type =/= stream</cell>
+      </row>
+      <row>
+	<cell>recvorigdstaddr</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>recvttl</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type =/= stream</cell>
+      </row>
+      <row>
+	<cell>retopts</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type =/= stream</cell>
+      </row>
+      <row>
+	<cell>router_alert</cell>
+	<cell>integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = raw</cell>
+      </row>
+      <row>
+	<cell>sendsrcaddr</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>tos</cell>
+	<cell>ip_tos()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>some high-priority levels may require superuser capability</cell>
+      </row>
+      <row>
+	<cell>transparent</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>requires admin capability</cell>
+      </row>
+      <row>
+	<cell>ttl</cell>
+	<cell>integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>unblock_source</cell>
+	<cell>ip_mreq_source()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <tcaption>ip options</tcaption>
+    </table>
+    
+    <p>Options for level <c>ipv6</c>: </p>
+    <table>
+      <row>
+	<cell><em>Option Name</em></cell>
+	<cell><em>Value Type</em></cell>
+	<cell><em>Set</em></cell>
+	<cell><em>Get</em></cell>
+	<cell><em>Other Requirements and comments</em></cell>
+      </row>
+      <row>
+	<cell>addrform</cell>
+	<cell>inet</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>allowed only for IPv6 sockets that are connected and bound to a
+	v4-mapped-on-v6 address</cell>
+      </row>
+      <row>
+	<cell>add_membership</cell>
+	<cell>ipv6_mreq()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>authhdr</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw, obsolete?</cell>
+      </row>
+      <row>
+	<cell>drop_membership</cell>
+	<cell>ipv6_mreq()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>dstopts</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw, requires superuser privileges to update</cell>
+      </row>
+      <row>
+	<cell>flowinfo</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw, requires superuser privileges to update</cell>
+      </row>
+      <row>
+	<cell>hoplimit</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw, requires superuser privileges to update</cell>
+      </row>
+      <row>
+	<cell>hopopts</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw, requires superuser privileges to update</cell>
+      </row>
+      <row>
+	<cell>mtu</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>Get: Only after the socket has been connected</cell>
+      </row>
+      <row>
+	<cell>mtu_discover</cell>
+	<cell>ipv6_pmtudisc()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>multicast_hops</cell>
+	<cell>default | uint8()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>multicast_if</cell>
+	<cell>integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw</cell>
+      </row>
+      <row>
+	<cell>multicast_loop</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>recverr</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>recvpktinfo | pktinfo</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw</cell>
+      </row>
+      <row>
+	<cell>router_alert</cell>
+	<cell>integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = raw</cell>
+      </row>
+      <row>
+	<cell>rthdr</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>type = dgram | raw, requires superuser privileges to update</cell>
+      </row>
+      <row>
+	<cell>unicast_hops</cell>
+	<cell>default | uint8()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>v6only</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <tcaption>ipv6 options</tcaption>
+    </table>
+    
+    <p>Options for level <c>tcp</c>: </p>
+    <table>
+      <row>
+	<cell><em>Option Name</em></cell>
+	<cell><em>Value Type</em></cell>
+	<cell><em>Set</em></cell>
+	<cell><em>Get</em></cell>
+	<cell><em>Other Requirements and comments</em></cell>
+      </row>
+      <row>
+	<cell>congestion</cell>
+	<cell>string()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>maxseg</cell>
+	<cell>integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>nodelay</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <tcaption>tcp options</tcaption>
+    </table>
+    
+    <p>Options for level <c>udp</c>: </p>
+    <table>
+      <row>
+	<cell><em>Option Name</em></cell>
+	<cell><em>Value Type</em></cell>
+	<cell><em>Set</em></cell>
+	<cell><em>Get</em></cell>
+	<cell><em>Other Requirements and comments</em></cell>
+      </row>
+      <row>
+	<cell>cork</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <tcaption>udp options</tcaption>
+    </table>
+    
+    <p>Options for level <c>sctp</c>: </p>
+    <table>
+      <row>
+	<cell><em>Option Name</em></cell>
+	<cell><em>Value Type</em></cell>
+	<cell><em>Set</em></cell>
+	<cell><em>Get</em></cell>
+	<cell><em>Other Requirements and comments</em></cell>
+      </row>
+      <row>
+	<cell>associnfo</cell>
+	<cell>sctp_assocparams()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>autoclose</cell>
+	<cell>non_neg_integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>disable_fragments</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>events</cell>
+	<cell>sctp_event_subscribe()</cell>
+	<cell>yes</cell>
+	<cell>no</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>initmsg</cell>
+	<cell>sctp_initmsg()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>maxseg</cell>
+	<cell>non_neg_integer()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>nodelay</cell>
+	<cell>boolean()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <row>
+	<cell>rtoinfo</cell>
+	<cell>sctp_rtoinfo()</cell>
+	<cell>yes</cell>
+	<cell>yes</cell>
+	<cell>none</cell>
+      </row>
+      <tcaption>sctp options</tcaption>
+    </table>
+    
+  </section>
+</chapter>
+
diff --git a/erts/doc/src/specs.xml b/erts/doc/src/specs.xml.src
index 0b943e6295..54224c15f5 100644
--- a/erts/doc/src/specs.xml
+++ b/erts/doc/src/specs.xml.src
@@ -5,6 +5,7 @@
   <xi:include href="../specs/specs_erl_tracer.xml"/>
   <xi:include href="../specs/specs_init.xml"/>
   <xi:include href="../specs/specs_persistent_term.xml"/>
+  %ESOCK_USE_SOCKET_SPECS_XML%
   <xi:include href="../specs/specs_zlib.xml"/>
   <xi:include href="../specs/specs_atomics.xml"/>
   <xi:include href="../specs/specs_counters.xml"/>
diff --git a/erts/doc/src/tty.xml b/erts/doc/src/tty.xml
index 51db1ba8e2..c33e082f4f 100644
--- a/erts/doc/src/tty.xml
+++ b/erts/doc/src/tty.xml
@@ -165,6 +165,10 @@ erl</pre>
         <cell align="left" valign="middle">C-y</cell>
         <cell align="left" valign="middle">Insert previously killed text</cell>
       </row>
+      <row>
+        <cell align="left" valign="middle">C-]</cell>
+        <cell align="left" valign="middle">Insert matching closing bracket</cell>
+      </row>
       <tcaption>tty Text Editing</tcaption>
     </table>
   </section>
diff --git a/erts/doc/src/zlib.xml b/erts/doc/src/zlib.xml
index 6f4c42da27..8a580c8d7b 100644
--- a/erts/doc/src/zlib.xml
+++ b/erts/doc/src/zlib.xml
@@ -29,7 +29,7 @@
     <rev></rev>
     <file>zlib.xml</file>
   </header>
-  <module>zlib</module>
+  <module since="">zlib</module>
   <modulesummary>zlib compression interface.</modulesummary>
   <description>
     <p>This module provides an API for the zlib library
@@ -120,7 +120,7 @@ list_to_binary([Compressed|Last])</pre>
 
   <funcs>
     <func>
-      <name name="adler32" arity="2"/>
+      <name name="adler32" arity="2" since=""/>
       <fsummary>Calculate the Adler checksum.</fsummary>
       <desc>
         <p>Calculates the Adler-32 checksum for <c><anno>Data</anno></c>.</p>
@@ -133,7 +133,7 @@ list_to_binary([Compressed|Last])</pre>
     </func>
 
     <func>
-      <name name="adler32" arity="3"/>
+      <name name="adler32" arity="3" since=""/>
       <fsummary>Calculate the Adler checksum.</fsummary>
       <desc>
         <p>Updates a running Adler-32 checksum for <c><anno>Data</anno></c>.
@@ -153,7 +153,7 @@ Crc = lists:foldl(fun(Data,Crc0) ->
     </func>
 
     <func>
-      <name name="adler32_combine" arity="4"/>
+      <name name="adler32_combine" arity="4" since=""/>
       <fsummary>Combine two Adler-32 checksums.</fsummary>
       <desc>
         <p>Combines two Adler-32 checksums into one. For two binaries or
@@ -172,7 +172,7 @@ Crc = lists:foldl(fun(Data,Crc0) ->
     </func>
 
     <func>
-      <name name="close" arity="1"/>
+      <name name="close" arity="1" since=""/>
       <fsummary>Close a stream.</fsummary>
       <desc>
         <p>Closes the stream referenced by <c><anno>Z</anno></c>.</p>
@@ -180,7 +180,7 @@ Crc = lists:foldl(fun(Data,Crc0) ->
     </func>
 
     <func>
-      <name name="compress" arity="1"/>
+      <name name="compress" arity="1" since=""/>
       <fsummary>Compress data with standard zlib functionality.</fsummary>
       <desc>
         <p>Compresses data with zlib headers and checksum.</p>
@@ -188,7 +188,7 @@ Crc = lists:foldl(fun(Data,Crc0) ->
     </func>
 
     <func>
-      <name name="crc32" arity="1"/>
+      <name name="crc32" arity="1" since=""/>
       <fsummary>Get current CRC.</fsummary>
       <desc>
         <p>Gets the current calculated CRC checksum.</p>
@@ -202,7 +202,7 @@ Crc = lists:foldl(fun(Data,Crc0) ->
     </func>
 
     <func>
-      <name name="crc32" arity="2"/>
+      <name name="crc32" arity="2" since=""/>
       <fsummary>Calculate CRC.</fsummary>
       <desc>
         <p>Calculates the CRC checksum for <c><anno>Data</anno></c>.</p>
@@ -215,7 +215,7 @@ Crc = lists:foldl(fun(Data,Crc0) ->
     </func>
 
     <func>
-      <name name="crc32" arity="3"/>
+      <name name="crc32" arity="3" since=""/>
       <fsummary>Calculate CRC.</fsummary>
       <desc>
         <p>Updates a running CRC checksum for <c><anno>Data</anno></c>.
@@ -235,7 +235,7 @@ Crc = lists:foldl(fun(Data,Crc0) ->
     </func>
 
     <func>
-      <name name="crc32_combine" arity="4"/>
+      <name name="crc32_combine" arity="4" since=""/>
       <fsummary>Combine two CRCs.</fsummary>
       <desc>
         <p>Combines two CRC checksums into one. For two binaries or iolists,
@@ -254,7 +254,7 @@ Crc = lists:foldl(fun(Data,Crc0) ->
     </func>
 
     <func>
-      <name name="deflate" arity="2"/>
+      <name name="deflate" arity="2" since=""/>
       <fsummary>Compress data.</fsummary>
       <desc>
         <p>Same as <c>deflate(<anno>Z</anno>, <anno>Data</anno>, none)</c>.</p>
@@ -262,7 +262,7 @@ Crc = lists:foldl(fun(Data,Crc0) ->
     </func>
 
     <func>
-      <name name="deflate" arity="3"/>
+      <name name="deflate" arity="3" since=""/>
       <fsummary>Compress data.</fsummary>
       <desc>
         <p>Compresses as much data as possible, and
@@ -300,7 +300,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="deflateEnd" arity="1"/>
+      <name name="deflateEnd" arity="1" since=""/>
       <fsummary>End deflate session.</fsummary>
       <desc>
         <p>Ends the deflate session and cleans all data used. Notice that this
@@ -311,7 +311,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="deflateInit" arity="1"/>
+      <name name="deflateInit" arity="1" since=""/>
       <fsummary>Initialize a session for compression.</fsummary>
       <desc>
         <p>Same as <c>zlib:deflateInit(<anno>Z</anno>, default)</c>.</p>
@@ -319,7 +319,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="deflateInit" arity="2"/>
+      <name name="deflateInit" arity="2" since=""/>
       <fsummary>Initialize a session for compression.</fsummary>
       <desc>
         <p>Initializes a zlib stream for compression.</p>
@@ -334,7 +334,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="deflateInit" arity="6"/>
+      <name name="deflateInit" arity="6" since=""/>
       <fsummary>Initialize a session for compression.</fsummary>
       <desc>
         <p>Initiates a zlib stream for compression.</p>
@@ -410,8 +410,8 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="deflateParams" arity="3"/>
-      <fsummary>Dynamicly update deflate parameters.</fsummary>
+      <name name="deflateParams" arity="3" since=""/>
+      <fsummary>Dynamically update deflate parameters.</fsummary>
       <desc>
         <p>Dynamically updates the compression level and compression
           strategy. The interpretation of <c><anno>Level</anno></c> and
@@ -432,7 +432,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="deflateReset" arity="1"/>
+      <name name="deflateReset" arity="1" since=""/>
       <fsummary>Reset the deflate session.</fsummary>
       <desc>
         <p>Equivalent to
@@ -446,7 +446,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="deflateSetDictionary" arity="2"/>
+      <name name="deflateSetDictionary" arity="2" since=""/>
       <fsummary>Initialize the compression dictionary.</fsummary>
       <desc>
         <p>Initializes the compression dictionary from the specified byte
@@ -464,7 +464,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="getBufSize" arity="1"/>
+      <name name="getBufSize" arity="1" since=""/>
       <fsummary>Get buffer size.</fsummary>
       <desc>
         <p>Gets the size of the intermediate buffer.</p>
@@ -476,7 +476,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="gunzip" arity="1"/>
+      <name name="gunzip" arity="1" since=""/>
       <fsummary>Uncompress data with gz header.</fsummary>
       <desc>
         <p>Uncompresses data with gz headers and checksum.</p>
@@ -484,7 +484,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="gzip" arity="1"/>
+      <name name="gzip" arity="1" since=""/>
       <fsummary>Compress data with gz header.</fsummary>
       <desc>
         <p>Compresses data with gz headers and checksum.</p>
@@ -492,7 +492,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="inflate" arity="2"/>
+      <name name="inflate" arity="2" since=""/>
       <fsummary>Decompress data.</fsummary>
       <desc>
         <p>Equivalent to
@@ -502,7 +502,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="inflate" arity="3"/>
+      <name name="inflate" arity="3" since="OTP 20.1"/>
       <fsummary>Decompress data.</fsummary>
       <desc>
         <p>Decompresses as much data as possible. It can introduce some output
@@ -524,7 +524,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="inflateChunk" arity="1"/>
+      <name name="inflateChunk" arity="1" since="OTP 18.0"/>
       <fsummary>Read next uncompressed chunk.</fsummary>
       <desc>
         <warning>
@@ -540,7 +540,7 @@ list_to_binary([B1,B2])</pre>
     </func>
 
     <func>
-      <name name="inflateChunk" arity="2"/>
+      <name name="inflateChunk" arity="2" since="OTP 18.0"/>
       <fsummary>Decompress data with limited output size.</fsummary>
       <desc>
         <warning>
@@ -584,7 +584,7 @@ loop(Z, Handler, Uncompressed) ->
     </func>
 
     <func>
-      <name name="inflateEnd" arity="1"/>
+      <name name="inflateEnd" arity="1" since=""/>
       <fsummary>End inflate session.</fsummary>
       <desc>
         <p>Ends the inflate session and cleans all data used. Notice
@@ -595,7 +595,7 @@ loop(Z, Handler, Uncompressed) ->
     </func>
 
     <func>
-      <name name="inflateGetDictionary" arity="1"/>
+      <name name="inflateGetDictionary" arity="1" since="OTP 20.0"/>
       <fsummary>Return the decompression dictionary.</fsummary>
       <desc>
         <p>Returns the decompression dictionary currently in use
@@ -607,7 +607,7 @@ loop(Z, Handler, Uncompressed) ->
     </func>
 
     <func>
-      <name name="inflateInit" arity="1"/>
+      <name name="inflateInit" arity="1" since=""/>
       <fsummary>Initialize a session for decompression.</fsummary>
       <desc>
         <p>Initializes a zlib stream for decompression.</p>
@@ -615,7 +615,7 @@ loop(Z, Handler, Uncompressed) ->
     </func>
 
     <func>
-      <name name="inflateInit" arity="2"/>
+      <name name="inflateInit" arity="2" since=""/>
       <fsummary>Initialize a session for decompression.</fsummary>
       <desc>
         <p>Initializes a decompression session on zlib stream.</p>
@@ -634,7 +634,7 @@ loop(Z, Handler, Uncompressed) ->
     </func>
 
     <func>
-      <name name="inflateReset" arity="1"/>
+      <name name="inflateReset" arity="1" since=""/>
       <fsummary>>Reset the inflate session.</fsummary>
       <desc>
         <p>Equivalent to
@@ -648,7 +648,7 @@ loop(Z, Handler, Uncompressed) ->
     </func>
 
     <func>
-      <name name="inflateSetDictionary" arity="2"/>
+      <name name="inflateSetDictionary" arity="2" since=""/>
       <fsummary>Initialize the decompression dictionary.</fsummary>
       <desc>
         <p>Initializes the decompression dictionary from the specified
@@ -688,7 +688,7 @@ new_unpack(Z, Compressed, Dict) ->
     </func>
 
     <func>
-      <name name="open" arity="0"/>
+      <name name="open" arity="0" since=""/>
       <fsummary>Open a stream and return a stream reference.</fsummary>
       <desc>
         <p>Opens a zlib stream.</p>
@@ -696,7 +696,7 @@ new_unpack(Z, Compressed, Dict) ->
     </func>
 
     <func>
-      <name name="safeInflate" arity="2"/>
+      <name name="safeInflate" arity="2" since="OTP 20.1"/>
       <fsummary>Decompress data with limited output size.</fsummary>
       <desc>
         <p>Like <seealso marker="#inflate/2"><c>inflate/2</c></seealso>,
@@ -733,7 +733,7 @@ loop(Z, Handler, {finished, Output}) ->
     </func>
 
     <func>
-      <name name="setBufSize" arity="2"/>
+      <name name="setBufSize" arity="2" since=""/>
       <fsummary>Set buffer size.</fsummary>
       <desc>
         <p>Sets the intermediate buffer size.</p>
@@ -745,7 +745,7 @@ loop(Z, Handler, {finished, Output}) ->
     </func>
 
     <func>
-      <name name="set_controlling_process" arity="2"/>
+      <name name="set_controlling_process" arity="2" since="OTP 20.1.3"/>
       <fsummary>Transfers ownership of a zlib stream.</fsummary>
       <desc>
         <p>Changes the controlling process of <c><anno>Z</anno></c> to
@@ -754,7 +754,7 @@ loop(Z, Handler, {finished, Output}) ->
     </func>
 
     <func>
-      <name name="uncompress" arity="1"/>
+      <name name="uncompress" arity="1" since=""/>
       <fsummary>Uncompress data with standard zlib functionality.</fsummary>
       <desc>
         <p>Uncompresses data with zlib headers and checksum.</p>
@@ -762,7 +762,7 @@ loop(Z, Handler, {finished, Output}) ->
     </func>
 
     <func>
-      <name name="unzip" arity="1"/>
+      <name name="unzip" arity="1" since=""/>
       <fsummary>Uncompress data without the zlib headers.</fsummary>
       <desc>
         <p>Uncompresses data without zlib headers and checksum.</p>
@@ -770,7 +770,7 @@ loop(Z, Handler, {finished, Output}) ->
     </func>
 
     <func>
-      <name name="zip" arity="1"/>
+      <name name="zip" arity="1" since=""/>
       <fsummary>Compress data without the zlib headers.</fsummary>
       <desc>
         <p>Compresses data without zlib headers and checksum.</p>
diff --git a/erts/emulator/Makefile.in b/erts/emulator/Makefile.in
index 57a9d45887..ba5ba8abef 100644
--- a/erts/emulator/Makefile.in
+++ b/erts/emulator/Makefile.in
@@ -1,7 +1,8 @@
+
 #
 # %CopyrightBegin%
 #
-# Copyright Ericsson AB 1996-2018. All Rights Reserved.
+# Copyright Ericsson AB 1996-2019. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -266,7 +267,6 @@ DEXPORT = @DEXPORT@
 RANLIB  = @RANLIB@
 STRIP   = strip
 PERL    = @PERL@
-RM	= @RM@
 MKDIR	= @MKDIR@
 
 USING_MINGW=@MIXED_CYGWIN_MINGW@
@@ -467,13 +467,13 @@ $(ERTS_LIB):
 
 .PHONY: clean
 clean:
-	$(RM) -f $(GENERATE)
-	$(RM) -rf $(TARGET)/*.c $(TARGET)/*.h $(TARGET)/*-GENERATED
-	$(RM) -rf $(TARGET)/*/*
-	$(RM) -rf obj/$(TARGET)
-	$(RM) -rf pcre/obj/$(TARGET) $(PCRE_GENINC)
-	$(RM) -rf zlib/obj/$(TARGET)
-	$(RM) -rf bin/$(TARGET)
+	$(RM) $(GENERATE)
+	$(RM) -r $(TARGET)/*.c $(TARGET)/*.h $(TARGET)/*-GENERATED
+	$(RM) -r $(TARGET)/*/*
+	$(RM) -r obj/$(TARGET)
+	$(RM) -r pcre/obj/$(TARGET) $(PCRE_GENINC)
+	$(RM) -r zlib/obj/$(TARGET)
+	$(RM) -r bin/$(TARGET)
 	cd $(ERTS_LIB_DIR) && $(MAKE) clean
 
 .PHONY: docs
@@ -633,14 +633,23 @@ GENERATE += $(TTF_DIR)/driver_tab.c
 # This list must be consistent with PRE_LOADED_MODULES in
 # erts/preloaded/src/Makefile.
 
-PRELOAD_BEAM =	$(ERL_TOP)/erts/preloaded/ebin/otp_ring0.beam \
-		$(ERL_TOP)/erts/preloaded/ebin/erts_code_purger.beam \
+ifeq ($(USE_ESOCK), yes)
+ESOCK_PRELOAD_BEAM = \
+	$(ERL_TOP)/erts/preloaded/ebin/socket.beam \
+	$(ERL_TOP)/erts/preloaded/ebin/prim_net.beam
+else
+ESOCK_PRELOAD_BEAM =
+endif
+
+PRELOAD_BEAM =	$(ERL_TOP)/erts/preloaded/ebin/erts_code_purger.beam \
+		$(ERL_TOP)/erts/preloaded/ebin/erl_init.beam \
 		$(ERL_TOP)/erts/preloaded/ebin/init.beam \
 		$(ERL_TOP)/erts/preloaded/ebin/prim_buffer.beam \
 		$(ERL_TOP)/erts/preloaded/ebin/prim_eval.beam \
 		$(ERL_TOP)/erts/preloaded/ebin/prim_inet.beam \
 		$(ERL_TOP)/erts/preloaded/ebin/prim_file.beam \
 		$(ERL_TOP)/erts/preloaded/ebin/zlib.beam \
+		$(ESOCK_PRELOAD_BEAM) \
 		$(ERL_TOP)/erts/preloaded/ebin/prim_zip.beam \
 		$(ERL_TOP)/erts/preloaded/ebin/erl_prim_loader.beam \
 		$(ERL_TOP)/erts/preloaded/ebin/erlang.beam \
@@ -833,6 +842,37 @@ EMU_OBJS = \
 	$(OBJDIR)/beam_catches.o 	$(OBJDIR)/code_ix.o \
 	$(OBJDIR)/beam_ranges.o
 
+
+ifeq ($(USE_ESOCK), yes)
+
+# WE ARE USING ESOCK
+
+ESOCK_NIF_OBJS = \
+	$(OBJDIR)/socket_nif.o \
+	$(OBJDIR)/prim_net_nif.o
+
+ifneq ($(TARGET), win32)
+# These are *currently* only needed for non-win32,
+# since the nif-functions for socket and net are basically
+# stubbed with notsup in the win32 case.
+ESOCK_RUN_OBJS = \
+	$(OBJDIR)/socket_dbg.o \
+	$(OBJDIR)/socket_tarray.o \
+	$(OBJDIR)/socket_util.o
+else
+ESOCK_RUN_OBJS =
+endif
+
+else
+
+# WE ARE *NOT* USING ESOCK
+
+ESOCK_NIF_OBJS =
+ESOCK_RUN_OBJS =
+
+endif
+
+
 RUN_OBJS += \
 	$(OBJDIR)/erl_alloc.o		$(OBJDIR)/erl_mtrace.o \
 	$(OBJDIR)/erl_alloc_util.o	$(OBJDIR)/erl_goodfit_alloc.o \
@@ -865,7 +905,7 @@ RUN_OBJS += \
 	$(OBJDIR)/register.o		$(OBJDIR)/break.o \
 	$(OBJDIR)/erl_async.o		$(OBJDIR)/erl_lock_check.o \
 	$(OBJDIR)/erl_gc.o 		$(OBJDIR)/erl_lock_count.o \
-	$(OBJDIR)/erl_posix_str.o	 \
+	$(OBJDIR)/erl_posix_str.o	\
 	$(OBJDIR)/erl_bits.o 		$(OBJDIR)/erl_math.o \
 	$(OBJDIR)/erl_fun.o             $(OBJDIR)/erl_bif_port.o \
 	$(OBJDIR)/erl_term.o 		$(OBJDIR)/erl_node_tables.o \
@@ -879,14 +919,17 @@ RUN_OBJS += \
 	$(OBJDIR)/erl_thr_queue.o	$(OBJDIR)/erl_sched_spec_pre_alloc.o \
 	$(OBJDIR)/erl_ptab.o		$(OBJDIR)/erl_map.o \
 	$(OBJDIR)/erl_msacc.o		$(OBJDIR)/erl_lock_flags.o \
-	$(OBJDIR)/erl_io_queue.o
+	$(OBJDIR)/erl_io_queue.o	$(OBJDIR)/erl_db_catree.o \
+	$(ESOCK_RUN_OBJS)		$(OBJDIR)/erl_flxctr.o
 
 LTTNG_OBJS = $(OBJDIR)/erlang_lttng.o
+
 NIF_OBJS = \
-	   $(OBJDIR)/erl_tracer_nif.o \
-	   $(OBJDIR)/prim_buffer_nif.o \
-	   $(OBJDIR)/prim_file_nif.o \
-	   $(OBJDIR)/zlib_nif.o
+	$(OBJDIR)/erl_tracer_nif.o \
+	$(OBJDIR)/prim_buffer_nif.o \
+	$(OBJDIR)/prim_file_nif.o \
+	$(OBJDIR)/zlib_nif.o \
+	$(ESOCK_NIF_OBJS)
 
 ifeq ($(TARGET),win32)
 DRV_OBJS = \
@@ -1147,7 +1190,15 @@ endif
 BEAM_SRC=$(wildcard beam/*.c)
 DRV_COMMON_SRC=$(wildcard drivers/common/*.c)
 DRV_OSTYPE_SRC=$(wildcard drivers/$(ERLANG_OSTYPE)/*.c)
+ifeq ($(TARGET), win32)
+# These are *currently* only needed for non-win32,
+# since the nif-functions for socket and net are basically
+# stubbed with badarg in the win32 case.
+NIF_SOCKET_UTILS_SRC=$(filter-out nifs/common/socket_nif.c, $(wildcard nifs/common/socket_*.c))
+NIF_COMMON_SRC=$(filter-out $(NIF_SOCKET_UTILS_SRC), $(wildcard nifs/common/*.c))
+else
 NIF_COMMON_SRC=$(wildcard nifs/common/*.c)
+endif
 NIF_OSTYPE_SRC=$(wildcard nifs/$(ERLANG_OSTYPE)/*.c)
 ALL_SYS_SRC=$(wildcard sys/$(ERLANG_OSTYPE)/*.c) $(wildcard sys/common/*.c)
 # We use $(shell ls) here instead of wildcard as $(wildcard ) resolved at
diff --git a/erts/emulator/beam/arith_instrs.tab b/erts/emulator/beam/arith_instrs.tab
index b828e86788..f14b376419 100644
--- a/erts/emulator/beam/arith_instrs.tab
+++ b/erts/emulator/beam/arith_instrs.tab
@@ -19,21 +19,22 @@
 // %CopyrightEnd%
 //
 
-OUTLINED_ARITH_2(Fail, Live, Name, BIF, Op1, Op2, Dst) {
+OUTLINED_ARITH_2(Fail, Name, BIF, Op1, Op2, Dst) {
     Eterm result;
-    Uint live = $Live;
-    HEAVY_SWAPOUT;
-    reg[live] = $Op1;
-    reg[live+1] = $Op2;
-    result = erts_gc_$Name (c_p, reg, live);
-    HEAVY_SWAPIN;
+#ifdef DEBUG
+    Eterm* orig_htop = HTOP;
+    Eterm* orig_stop = E;
+#endif
+    DEBUG_SWAPOUT;
+    result = erts_$Name (c_p, $Op1, $Op2);
+    DEBUG_SWAPIN;
+    ASSERT(orig_htop == HTOP && orig_stop == E);
     ERTS_HOLE_CHECK(c_p);
     if (ERTS_LIKELY(is_value(result))) {
-        $REFRESH_GEN_DEST();
         $Dst = result;
         $NEXT0();
     }
-    $BIF_ERROR_ARITY_2($Fail, $BIF, reg[live], reg[live+1]);
+    $BIF_ERROR_ARITY_2($Fail, $BIF, $Op1, $Op2);
 }
 
 
@@ -48,15 +49,54 @@ plus.fetch(Op1, Op2) {
     PlusOp2 = $Op2;
 }
 
-plus.execute(Fail, Live, Dst) {
+plus.execute(Fail, Dst) {
     if (ERTS_LIKELY(is_both_small(PlusOp1, PlusOp2))) {
+#ifdef HAVE_OVERFLOW_CHECK_BUILTINS
+        Sint lhs_tagged, rhs_untagged, res;
+
+        /* The value part of immediate integers start right after the tag and
+         * occupy the rest of the word, so if you squint a bit they look like
+         * fixed-point integers; as long as you mask the tag away you will get
+         * correct results from addition/subtraction since they share the same
+         * notion of zero. It's fairly easy to see that the following holds
+         * when (a + b) is in range:
+         *
+         *     (a >> s) + (b >> s) == ((a & ~m) + (b & ~m)) >> s
+         *
+         * Where 's' is the tag size and 'm' is the tag mask.
+         *
+         * The left-hand side is our fallback in the #else clause and is the
+         * fastest way to do this safely in plain C. The actual addition will
+         * never overflow since `Sint` has a much greater range than our
+         * smalls, so we can use the IS_SSMALL macro to see if the result is
+         * within range.
+         *
+         * What we're doing below is an extension of the right-hand side. By
+         * treating `a` and `b` as fixed-point integers, all additions whose
+         * result is out of range will also overflow `Sint` and we can use the
+         * compiler's overflow intrinsics to check for this condition.
+         *
+         * In addition, since the tag lives in the lowest bits we can further
+         * optimize this by only stripping the tag from either side. The higher
+         * bits can't influence the tag bits since we bail on overflow, so the
+         * tag bits from the tagged side will simply appear in the result. */
+        lhs_tagged = PlusOp1;
+        rhs_untagged = PlusOp2 & ~_TAG_IMMED1_MASK;
+
+        if (ERTS_LIKELY(!__builtin_add_overflow(lhs_tagged, rhs_untagged, &res))) {
+            ASSERT(is_small(res));
+            $Dst = res;
+            $NEXT0();
+        }
+#else
         Sint i = signed_val(PlusOp1) + signed_val(PlusOp2);
         if (ERTS_LIKELY(IS_SSMALL(i))) {
             $Dst = make_small(i);
             $NEXT0();
         }
+#endif
     }
-    $OUTLINED_ARITH_2($Fail, $Live, mixed_plus, BIF_splus_2, PlusOp1, PlusOp2, $Dst);
+    $OUTLINED_ARITH_2($Fail, mixed_plus, BIF_splus_2, PlusOp1, PlusOp2, $Dst);
 }
 
 i_minus := minus.fetch.execute;
@@ -70,15 +110,30 @@ minus.fetch(Op1, Op2) {
     MinusOp2 = $Op2;
 }
 
-minus.execute(Fail, Live, Dst) {
+minus.execute(Fail, Dst) {
     if (ERTS_LIKELY(is_both_small(MinusOp1, MinusOp2))) {
+#ifdef HAVE_OVERFLOW_CHECK_BUILTINS
+        Sint lhs_tagged, rhs_untagged, res;
+
+        /* See plus.execute */
+        lhs_tagged = MinusOp1;
+        rhs_untagged = MinusOp2 & ~_TAG_IMMED1_MASK;
+
+        if (ERTS_LIKELY(!__builtin_sub_overflow(lhs_tagged, rhs_untagged, &res))) {
+            ASSERT(is_small(res));
+            $Dst = res;
+            $NEXT0();
+        }
+#else
         Sint i = signed_val(MinusOp1) - signed_val(MinusOp2);
+
         if (ERTS_LIKELY(IS_SSMALL(i))) {
             $Dst = make_small(i);
             $NEXT0();
         }
+#endif
     }
-    $OUTLINED_ARITH_2($Fail, $Live, mixed_minus, BIF_sminus_2, MinusOp1, MinusOp2, $Dst);
+    $OUTLINED_ARITH_2($Fail, mixed_minus, BIF_sminus_2, MinusOp1, MinusOp2, $Dst);
 }
 
 i_increment := increment.fetch.execute;
@@ -91,27 +146,35 @@ increment.fetch(Src) {
     increment_reg_val = $Src;
 }
 
-increment.execute(IncrementVal, Live, Dst) {
+increment.execute(IncrementVal, Dst) {
     Eterm increment_val = $IncrementVal;
-    Uint live;
     Eterm result;
 
     if (ERTS_LIKELY(is_small(increment_reg_val))) {
+#ifdef HAVE_OVERFLOW_CHECK_BUILTINS
+        Sint lhs_tagged, rhs_untagged, res;
+
+        /* See plus.execute */
+        lhs_tagged = increment_reg_val;
+        rhs_untagged = (Sint)increment_val << _TAG_IMMED1_SIZE;
+
+        if (ERTS_LIKELY(!__builtin_add_overflow(lhs_tagged, rhs_untagged, &res))) {
+            ASSERT(is_small(res));
+            $Dst = res;
+            $NEXT0();
+        }
+#else
         Sint i = signed_val(increment_reg_val) + increment_val;
         if (ERTS_LIKELY(IS_SSMALL(i))) {
             $Dst = make_small(i);
             $NEXT0();
         }
+#endif
     }
-    live = $Live;
-    HEAVY_SWAPOUT;
-    reg[live] = increment_reg_val;
-    reg[live+1] = make_small(increment_val);
-    result = erts_gc_mixed_plus(c_p, reg, live);
-    HEAVY_SWAPIN;
+
+    result = erts_mixed_plus(c_p, increment_reg_val, make_small(increment_val));
     ERTS_HOLE_CHECK(c_p);
     if (ERTS_LIKELY(is_value(result))) {
-        $REFRESH_GEN_DEST();
         $Dst = result;
         $NEXT0();
     }
@@ -119,19 +182,34 @@ increment.execute(IncrementVal, Live, Dst) {
     goto find_func_info;
 }
 
-i_times(Fail, Live, Op1, Op2, Dst) {
+i_times(Fail, Op1, Op2, Dst) {
     Eterm op1 = $Op1;
     Eterm op2 = $Op2;
-    $OUTLINED_ARITH_2($Fail, $Live, mixed_times, BIF_stimes_2, op1, op2, $Dst);
+#ifdef HAVE_OVERFLOW_CHECK_BUILTINS
+    if (ERTS_LIKELY(is_both_small(op1, op2))) {
+        /* See plus.execute */
+        Sint lhs_untagged, rhs_actual, res;
+
+        lhs_untagged = op1 & ~_TAG_IMMED1_MASK;
+        rhs_actual = signed_val(op2);
+
+        if (ERTS_LIKELY(!__builtin_mul_overflow(lhs_untagged, rhs_actual, &res))) {
+            ASSERT(!(res & _TAG_IMMED1_MASK));
+            $Dst = res | _TAG_IMMED1_SMALL;
+            $NEXT0();
+        }
+    }
+#endif
+    $OUTLINED_ARITH_2($Fail, mixed_times, BIF_stimes_2, op1, op2, $Dst);
 }
 
-i_m_div(Fail, Live, Op1, Op2, Dst) {
+i_m_div(Fail, Op1, Op2, Dst) {
     Eterm op1 = $Op1;
     Eterm op2 = $Op2;
-    $OUTLINED_ARITH_2($Fail, $Live, mixed_div, BIF_div_2, op1, op2, $Dst);
+    $OUTLINED_ARITH_2($Fail, mixed_div, BIF_div_2, op1, op2, $Dst);
 }
 
-i_int_div(Fail, Live, Op1, Op2, Dst) {
+i_int_div(Fail, Op1, Op2, Dst) {
     Eterm op1 = $Op1;
     Eterm op2 = $Op2;
     if (ERTS_UNLIKELY(op2 == SMALL_ZERO)) {
@@ -144,7 +222,7 @@ i_int_div(Fail, Live, Op1, Op2, Dst) {
             $NEXT0();
         }
     }
-    $OUTLINED_ARITH_2($Fail, $Live, int_div, BIF_intdiv_2, op1, op2, $Dst);
+    $OUTLINED_ARITH_2($Fail, int_div, BIF_intdiv_2, op1, op2, $Dst);
 }
 
 i_rem := rem.fetch.execute;
@@ -158,7 +236,7 @@ rem.fetch(Src1, Src2) {
     RemOp2 = $Src2;
 }
 
-rem.execute(Fail, Live, Dst) {
+rem.execute(Fail, Dst) {
     if (ERTS_UNLIKELY(RemOp2 == SMALL_ZERO)) {
         c_p->freason = BADARITH;
         $BIF_ERROR_ARITY_2($Fail, BIF_rem_2, RemOp1, RemOp2);
@@ -166,7 +244,7 @@ rem.execute(Fail, Live, Dst) {
         $Dst = make_small(signed_val(RemOp1) % signed_val(RemOp2));
         $NEXT0();
     } else {
-        $OUTLINED_ARITH_2($Fail, $Live, int_rem, BIF_rem_2, RemOp1, RemOp2, $Dst);
+        $OUTLINED_ARITH_2($Fail, int_rem, BIF_rem_2, RemOp1, RemOp2, $Dst);
     }
 }
 
@@ -181,7 +259,7 @@ band.fetch(Src1, Src2) {
     BandOp2 = $Src2;
 }
 
-band.execute(Fail, Live, Dst) {
+band.execute(Fail, Dst) {
     if (ERTS_LIKELY(is_both_small(BandOp1, BandOp2))) {
         /*
          * No need to untag -- TAG & TAG == TAG.
@@ -189,10 +267,10 @@ band.execute(Fail, Live, Dst) {
         $Dst = BandOp1 & BandOp2;
         $NEXT0();
     }
-    $OUTLINED_ARITH_2($Fail, $Live, band, BIF_band_2, BandOp1, BandOp2, $Dst);
+    $OUTLINED_ARITH_2($Fail, band, BIF_band_2, BandOp1, BandOp2, $Dst);
 }
 
-i_bor(Fail, Live, Src1, Src2, Dst) {
+i_bor(Fail, Src1, Src2, Dst) {
     if (ERTS_LIKELY(is_both_small($Src1, $Src2))) {
         /*
          * No need to untag -- TAG | TAG == TAG.
@@ -200,10 +278,10 @@ i_bor(Fail, Live, Src1, Src2, Dst) {
         $Dst = $Src1 | $Src2;
         $NEXT0();
     }
-    $OUTLINED_ARITH_2($Fail, $Live, bor, BIF_bor_2, $Src1, $Src2, $Dst);
+    $OUTLINED_ARITH_2($Fail, bor, BIF_bor_2, $Src1, $Src2, $Dst);
 }
 
-i_bxor(Fail, Live, Src1, Src2, Dst) {
+i_bxor(Fail, Src1, Src2, Dst) {
     if (ERTS_LIKELY(is_both_small($Src1, $Src2))) {
         /*
          * TAG ^ TAG == 0.
@@ -214,7 +292,7 @@ i_bxor(Fail, Live, Src1, Src2, Dst) {
         $Dst = ($Src1 ^ $Src2) | make_small(0);
         $NEXT0();
     }
-    $OUTLINED_ARITH_2($Fail, $Live, bxor, BIF_bxor_2, $Src1, $Src2, $Dst);
+    $OUTLINED_ARITH_2($Fail, bxor, BIF_bxor_2, $Src1, $Src2, $Dst);
 }
 
 i_bsl := shift.setup_bsl.execute;
@@ -265,7 +343,7 @@ shift.setup_bsl(Src1, Src2) {
     }
 }
 
-shift.execute(Fail, Live, Dst) {
+shift.execute(Fail, Dst) {
     Uint big_words_needed;
 
     if (ERTS_LIKELY(is_small(Op1))) {
@@ -320,7 +398,9 @@ shift.execute(Fail, Live, Dst) {
         }
         {
             Eterm tmp_big[2];
-            Sint big_need_size = BIG_NEED_SIZE(big_words_needed+1);
+            Sint big_need_size = 1 + BIG_NEED_SIZE(big_words_needed+1);
+            Eterm* hp;
+            Eterm* hp_end;
 
             /*
              * Slightly conservative check the size to avoid
@@ -331,15 +411,16 @@ shift.execute(Fail, Live, Dst) {
             if (big_need_size-8 > BIG_ARITY_MAX) {
                 $SYSTEM_LIMIT($Fail);
             }
-            $GC_TEST_PRESERVE(big_need_size+1, $Live, Op1);
+            hp = HeapFragOnlyAlloc(c_p, big_need_size);
             if (is_small(Op1)) {
                 Op1 = small_to_big(signed_val(Op1), tmp_big);
             }
-            Op1 = big_lshift(Op1, shift_left_count, HTOP);
+            Op1 = big_lshift(Op1, shift_left_count, hp);
+            hp_end = hp + big_need_size;
             if (is_big(Op1)) {
-                HTOP += bignum_header_arity(*HTOP) + 1;
+                hp += bignum_header_arity(*hp) + 1;
             }
-            HEAP_SPACE_VERIFIED(0);
+            HRelease(c_p, hp_end, hp);
             if (ERTS_UNLIKELY(is_nil(Op1))) {
                 /*
                  * This result must have been only slighty larger
@@ -349,7 +430,6 @@ shift.execute(Fail, Live, Dst) {
                 $SYSTEM_LIMIT($Fail);
             }
             ERTS_HOLE_CHECK(c_p);
-            $REFRESH_GEN_DEST();
             $Dst = Op1;
             $NEXT0();
         }
@@ -366,31 +446,28 @@ shift.execute(Fail, Live, Dst) {
         reg[0] = Op1;
         reg[1] = Op2;
         SWAPOUT;
-        if (IsOpCode(I[0], i_bsl_ssjtd)) {
+        if (IsOpCode(I[0], i_bsl_ssjd)) {
             I = handle_error(c_p, I, reg, &bif_export[BIF_bsl_2]->info.mfa);
         } else {
-            ASSERT(IsOpCode(I[0], i_bsr_ssjtd));
+            ASSERT(IsOpCode(I[0], i_bsr_ssjd));
             I = handle_error(c_p, I, reg, &bif_export[BIF_bsr_2]->info.mfa);
         }
         goto post_error_handling;
     }
 }
 
-i_int_bnot(Fail, Src, Live, Dst) {
+i_int_bnot(Fail, Src, Dst) {
     Eterm bnot_val = $Src;
+    Eterm result;
+
     if (ERTS_LIKELY(is_small(bnot_val))) {
-        bnot_val = make_small(~signed_val(bnot_val));
+        result = make_small(~signed_val(bnot_val));
     } else {
-        Uint live = $Live;
-        HEAVY_SWAPOUT;
-        reg[live] = bnot_val;
-        bnot_val = erts_gc_bnot(c_p, reg, live);
-        HEAVY_SWAPIN;
+        result = erts_bnot(c_p, bnot_val);
         ERTS_HOLE_CHECK(c_p);
-        if (ERTS_UNLIKELY(is_nil(bnot_val))) {
-            $BIF_ERROR_ARITY_1($Fail, BIF_bnot_1, reg[live]);
+        if (ERTS_UNLIKELY(is_nil(result))) {
+            $BIF_ERROR_ARITY_1($Fail, BIF_bnot_1, bnot_val);
         }
-        $REFRESH_GEN_DEST();
     }
-    $Dst = bnot_val;
+    $Dst = result;
 }
diff --git a/erts/emulator/beam/atom.c b/erts/emulator/beam/atom.c
index 59b51fd15e..5a70509ffd 100644
--- a/erts/emulator/beam/atom.c
+++ b/erts/emulator/beam/atom.c
@@ -200,11 +200,15 @@ atom_free(Atom* obj)
     ASSERT(obj->slot.index == atom_val(am_ErtsSecretAtom));
 }
 
-static void latin1_to_utf8(byte* conv_buf, const byte** srcp, int* lenp)
+static void latin1_to_utf8(byte* conv_buf, Uint buf_sz,
+                           const byte** srcp, Uint* lenp)
 {
     byte* dst;
     const byte* src = *srcp;
-    int i, len = *lenp;
+    Uint i, len = *lenp;
+
+    ASSERT(len <= MAX_ATOM_CHARACTERS);
+    ASSERT(buf_sz >= MAX_ATOM_SZ_FROM_LATIN1);
 
     for (i=0 ; i < len; ++i) {
 	if (src[i] & 0x80) {
@@ -234,11 +238,11 @@ need_convertion:
  * erts_atom_put_index() may fail. Returns negative indexes for errors.
  */
 int
-erts_atom_put_index(const byte *name, int len, ErtsAtomEncoding enc, int trunc)
+erts_atom_put_index(const byte *name, Sint len, ErtsAtomEncoding enc, int trunc)
 {
     byte utf8_copy[MAX_ATOM_SZ_FROM_LATIN1];
     const byte *text = name;
-    int tlen = len;
+    Uint tlen;
     Sint no_latin1_chars;
     Atom a;
     int aix;
@@ -247,13 +251,16 @@ erts_atom_put_index(const byte *name, int len, ErtsAtomEncoding enc, int trunc)
     erts_atomic_inc_nob(&atom_put_ops);
 #endif
 
-    if (tlen < 0) {
-	if (trunc)
-	    tlen = 0;
-	else
-	    return ATOM_MAX_CHARS_ERROR;
+    if (len < 0) {
+        if (trunc) {
+            len = 0;
+        } else {
+            return ATOM_MAX_CHARS_ERROR;
+        }
     }
 
+    tlen = len;
+
     switch (enc) {
     case ERTS_ATOM_ENC_7BIT_ASCII:
 	if (tlen > MAX_ATOM_CHARACTERS) {
@@ -277,7 +284,7 @@ erts_atom_put_index(const byte *name, int len, ErtsAtomEncoding enc, int trunc)
 		return ATOM_MAX_CHARS_ERROR;
 	}
 	no_latin1_chars = tlen;
-	latin1_to_utf8(utf8_copy, &text, &tlen);
+	latin1_to_utf8(utf8_copy, sizeof(utf8_copy), &text, &tlen);
 	break;
     case ERTS_ATOM_ENC_UTF8:
 	/* First sanity check; need to verify later */
@@ -338,7 +345,7 @@ erts_atom_put_index(const byte *name, int len, ErtsAtomEncoding enc, int trunc)
  * erts_atom_put() may fail. If it fails THE_NON_VALUE is returned!
  */
 Eterm
-erts_atom_put(const byte *name, int len, ErtsAtomEncoding enc, int trunc)
+erts_atom_put(const byte *name, Sint len, ErtsAtomEncoding enc, int trunc)
 {
     int aix = erts_atom_put_index(name, len, enc, trunc);
     if (aix >= 0)
@@ -348,7 +355,7 @@ erts_atom_put(const byte *name, int len, ErtsAtomEncoding enc, int trunc)
 }
 
 Eterm
-am_atom_put(const char* name, int len)
+am_atom_put(const char* name, Sint len)
 {
     /* Assumes 7-bit ascii; use erts_atom_put() for other encodings... */
     return erts_atom_put((byte *) name, len, ERTS_ATOM_ENC_7BIT_ASCII, 1);
@@ -379,23 +386,57 @@ int atom_table_sz(void)
 }
 
 int
-erts_atom_get(const char *name, int len, Eterm* ap, ErtsAtomEncoding enc)
+erts_atom_get(const char *name, Uint len, Eterm* ap, ErtsAtomEncoding enc)
 {
     byte utf8_copy[MAX_ATOM_SZ_FROM_LATIN1];
     Atom a;
     int i;
     int res;
 
-    a.len = (Sint16) len;
-    a.name = (byte *)name;
-    if (enc == ERTS_ATOM_ENC_LATIN1) {
-	latin1_to_utf8(utf8_copy, (const byte**)&a.name, &len);
-	a.len = (Sint16) len;
+    switch (enc) {
+    case ERTS_ATOM_ENC_LATIN1:
+        if (len > MAX_ATOM_CHARACTERS) {
+            return 0;
+        }
+
+        latin1_to_utf8(utf8_copy, sizeof(utf8_copy), (const byte**)&name, &len);
+
+        a.name = (byte*)name;
+        a.len = (Sint16)len;
+        break;
+    case ERTS_ATOM_ENC_7BIT_ASCII:
+        if (len > MAX_ATOM_CHARACTERS) {
+            return 0;
+        }
+
+        for (i = 0; i < len; i++) {
+            if (name[i] & 0x80) {
+                return 0;
+            }
+        }
+
+        a.len = (Sint16)len;
+        a.name = (byte*)name;
+        break;
+    case ERTS_ATOM_ENC_UTF8:
+        if (len > MAX_ATOM_SZ_LIMIT) {
+            return 0;
+        }
+
+        /* We don't need to check whether the encoding is legal as all atom
+         * names are stored as UTF-8 and we know a lookup with a badly encoded
+         * name will fail. */
+
+        a.len = (Sint16)len;
+        a.name = (byte*)name;
+        break;
     }
+
     atom_read_lock();
     i = index_get(&erts_atom_table, (void*) &a);
     res = i < 0 ? 0 : (*ap = make_atom(i), 1);
     atom_read_unlock();
+
     return res;
 }
 
diff --git a/erts/emulator/beam/atom.h b/erts/emulator/beam/atom.h
index ca920679c6..f51c5a8c62 100644
--- a/erts/emulator/beam/atom.h
+++ b/erts/emulator/beam/atom.h
@@ -133,14 +133,14 @@ typedef enum {
 int atom_table_size(void);	/* number of elements */
 int atom_table_sz(void);	/* table size in bytes, excluding stored objects */
 
-Eterm am_atom_put(const char*, int); /* ONLY 7-bit ascii! */
-Eterm erts_atom_put(const byte *name, int len, ErtsAtomEncoding enc, int trunc);
-int erts_atom_put_index(const byte *name, int len, ErtsAtomEncoding enc, int trunc);
+Eterm am_atom_put(const char*, Sint); /* ONLY 7-bit ascii! */
+Eterm erts_atom_put(const byte *name, Sint len, ErtsAtomEncoding enc, int trunc);
+int erts_atom_put_index(const byte *name, Sint len, ErtsAtomEncoding enc, int trunc);
 void init_atom_table(void);
 void atom_info(fmtfn_t, void *);
 void dump_atoms(fmtfn_t, void *);
 Uint erts_get_atom_limit(void);
-int erts_atom_get(const char* name, int len, Eterm* ap, ErtsAtomEncoding enc);
+int erts_atom_get(const char* name, Uint len, Eterm* ap, ErtsAtomEncoding enc);
 void erts_atom_get_text_space_sizes(Uint *reserved, Uint *used);
 #endif
 
diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index a14f22b19e..412d689246 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -209,7 +209,6 @@ atom dirty_nif_finalizer
 atom disable_trace
 atom disabled
 atom discard
-atom display_items
 atom dist
 atom dist_cmd
 atom dist_ctrl_put_data
@@ -238,6 +237,7 @@ atom eof
 atom eol
 atom Eq='=:='
 atom Eqeq='=='
+atom erl_init
 atom erl_tracer
 atom erlang
 atom erl_signal_server
@@ -290,6 +290,7 @@ atom Ge='>='
 atom generational
 atom get_all_trap
 atom get_seq_token
+atom get_size
 atom get_tcw
 atom gather_gc_info_result
 atom gather_io_bytes
@@ -546,6 +547,7 @@ atom reload
 atom rem
 atom report_errors
 atom reset
+atom reset_seq_trace
 atom restart
 atom return_from
 atom return_to
diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
index bb1b2e5b27..4c8ee5178a 100644
--- a/erts/emulator/beam/beam_bif_load.c
+++ b/erts/emulator/beam/beam_bif_load.c
@@ -1799,6 +1799,78 @@ erts_queue_release_literals(Process* c_p, ErtsLiteralArea* literals)
     }
 }
 
+struct debug_la_oh {
+    void (*func)(ErlOffHeap *, void *);
+    void *arg;
+};
+
+static void debug_later_cleanup_literal_area_off_heap(void *vfap,
+                                                      ErtsThrPrgrVal val,
+                                                      void *vlrlap)
+{
+    struct debug_la_oh *fap = vfap;
+    ErtsLaterReleasLiteralArea *lrlap = vlrlap;
+    ErtsLiteralArea *lap = lrlap->la;
+    if (!erts_debug_have_accessed_literal_area(lap)) {
+        ErlOffHeap oh;
+        ERTS_INIT_OFF_HEAP(&oh);
+        oh.first = lap->off_heap;
+        (*fap->func)(&oh, fap->arg);
+        erts_debug_save_accessed_literal_area(lap);
+    }
+}
+
+static void debug_later_complete_literal_area_switch_off_heap(void *vfap,
+                                                              ErtsThrPrgrVal val,
+                                                              void *vlap)
+{
+    struct debug_la_oh *fap = vfap;
+    ErtsLiteralArea *lap = vlap;
+    if (lap && !erts_debug_have_accessed_literal_area(lap)) {
+        ErlOffHeap oh;
+        ERTS_INIT_OFF_HEAP(&oh);
+        oh.first = lap->off_heap;
+        (*fap->func)(&oh, fap->arg);
+        erts_debug_save_accessed_literal_area(lap);
+    }
+}
+
+
+void
+erts_debug_foreach_release_literal_area_off_heap(void (*func)(ErlOffHeap *, void *), void *arg)
+{
+    ErtsLiteralArea *lap;
+    ErlOffHeap oh;
+    ErtsLiteralAreaRef *ref;
+    struct debug_la_oh fa;
+    erts_mtx_lock(&release_literal_areas.mtx);
+    for (ref = release_literal_areas.first; ref; ref = ref->next) {
+        lap = ref->literal_area;
+        if (!erts_debug_have_accessed_literal_area(lap)) {
+            ERTS_INIT_OFF_HEAP(&oh);
+            oh.first = lap->off_heap;
+            (*func)(&oh, arg);
+            erts_debug_save_accessed_literal_area(lap);
+        }
+    }
+    erts_mtx_unlock(&release_literal_areas.mtx);
+    lap = ERTS_COPY_LITERAL_AREA();
+    if (lap && !erts_debug_have_accessed_literal_area(lap)) {
+        ERTS_INIT_OFF_HEAP(&oh);
+        oh.first = lap->off_heap;
+        (*func)(&oh, arg);
+        erts_debug_save_accessed_literal_area(lap);
+    }
+    fa.func = func;
+    fa.arg = arg;
+    erts_debug_later_op_foreach(later_release_literal_area,
+                                debug_later_cleanup_literal_area_off_heap,
+                                (void *) &fa);
+    erts_debug_later_op_foreach(complete_literal_area_switch,
+                                debug_later_complete_literal_area_switch_off_heap,
+                                (void *) &fa);
+}
+
 /*
  * Move code from current to old and null all export entries for the module
  */
diff --git a/erts/emulator/beam/beam_debug.c b/erts/emulator/beam/beam_debug.c
index 9633de2021..4d52435139 100644
--- a/erts/emulator/beam/beam_debug.c
+++ b/erts/emulator/beam/beam_debug.c
@@ -332,6 +332,13 @@ erts_debug_disassemble_1(BIF_ALIST_1)
 		   "unknown " HEXF "\n", instr);
 	code_ptr++;
     }
+    if (i == op_call_nif) {
+        /*
+         * The rest of the code will not be executed. Don't disassemble any
+         * more code in this function.
+         */
+        code_ptr = 0;
+    }
     bin = new_binary(p, (byte *) dsbufp->str, dsbufp->str_len);
     erts_destroy_tmp_dsbuf(dsbufp);
     hsz = 4+4;
@@ -346,6 +353,22 @@ erts_debug_disassemble_1(BIF_ALIST_1)
     return TUPLE3(hp, addr, bin, mfa);
 }
 
+BIF_RETTYPE
+erts_debug_interpreter_size_0(BIF_ALIST_0)
+{
+    int i;
+    BeamInstr low, high;
+
+    low = high = (BeamInstr) process_main;
+    for (i = 0; i < NUM_SPECIFIC_OPS; i++) {
+        BeamInstr a = BeamOpCodeAddr(i);
+        if (a > high) {
+            high = a;
+        }
+    }
+    return erts_make_integer(high - low, BIF_P);
+}
+
 void
 dbg_bt(Process* p, Eterm* sp)
 {
@@ -558,23 +581,6 @@ print_op(fmtfn_t to, void *to_arg, int op, int size, BeamInstr* addr)
 	case 'I':
         case 'W':
 	    switch (op) {
-	    case op_i_gc_bif1_jWstd:
-	    case op_i_gc_bif2_jWtssd:
-	    case op_i_gc_bif3_jWtssd:
-		{
-		    const ErtsGcBif* p;
-		    BifFunction gcf = (BifFunction) *ap;
-		    for (p = erts_gc_bifs; p->bif != 0; p++) {
-			if (p->gc_bif == gcf) {
-			    print_bif_name(to, to_arg, p->bif);
-			    break;
-			}
-		    }
-		    if (p->bif == 0) {
-			erts_print(to, to_arg, "%d", (Uint)gcf);
-		    }
-		    break;
-		}
 	    case op_i_make_fun_Wt:
                 if (*sign == 'W') {
                     ErlFunEntry* fe = (ErlFunEntry *) *ap;
@@ -586,6 +592,7 @@ print_op(fmtfn_t to, void *to_arg, int op, int size, BeamInstr* addr)
                 }
                 break;
 	    case op_i_bs_match_string_xfWW:
+	    case op_i_bs_match_string_yfWW:
                 if (ap - first_arg < 3) {
                     erts_print(to, to_arg, "%d", *ap);
                 } else {
@@ -786,11 +793,14 @@ print_op(fmtfn_t to, void *to_arg, int op, int size, BeamInstr* addr)
 	    }
 	}
 	break;
-    case op_i_put_tuple_xI:
-    case op_i_put_tuple_yI:
+    case op_put_tuple2_xI:
+    case op_put_tuple2_yI:
     case op_new_map_dtI:
-    case op_update_map_assoc_sdtI:
-    case op_update_map_exact_jsdtI:
+    case op_update_map_assoc_xdtI:
+    case op_update_map_assoc_ydtI:
+    case op_update_map_assoc_cdtI:
+    case op_update_map_exact_xjdtI:
+    case op_update_map_exact_yjdtI:
 	{
 	    int n = unpacked[-1];
 
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index e909a0b4da..07c16e3415 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -206,8 +206,12 @@ void** beam_ops;
 #ifdef DEBUG
 #  /* The stack pointer is used in an assertion. */
 #  define LIGHT_SWAPOUT SWAPOUT
+#  define DEBUG_SWAPOUT SWAPOUT
+#  define DEBUG_SWAPIN  SWAPIN
 #else
 #  define LIGHT_SWAPOUT HEAP_TOP(c_p) = HTOP
+#  define DEBUG_SWAPOUT
+#  define DEBUG_SWAPIN
 #endif
 
 /*
@@ -318,19 +322,19 @@ void** beam_ops;
 
 #define Arg(N)       I[(N)+1]
 
-#define GetR(pos, tr)				\
+#define GetSource(raw, dst)			\
    do {						\
-     tr = Arg(pos);				\
-     switch (loader_tag(tr)) {			\
+     dst = raw;                                 \
+     switch (loader_tag(dst)) {			\
      case LOADER_X_REG:				\
-        tr = x(loader_x_reg_index(tr));		\
+        dst = x(loader_x_reg_index(dst));       \
         break;					\
      case LOADER_Y_REG:				\
-        ASSERT(loader_y_reg_index(tr) >= 1);	\
-        tr = y(loader_y_reg_index(tr));		\
+        ASSERT(loader_y_reg_index(dst) >= 1);	\
+        dst = y(loader_y_reg_index(dst));       \
         break;					\
      }						\
-     CHECK_TERM(tr);				\
+     CHECK_TERM(dst);				\
    } while (0)
 
 #define PUT_TERM_REG(term, desc)		\
@@ -371,44 +375,33 @@ do {                                            \
 
 /*
  * process_main() is already huge, so we want to avoid inlining
- * into it. Especially functions that are seldom used.
+ * seldom used functions into it.
  */
-#ifdef __GNUC__
-#  define NOINLINE __attribute__((__noinline__))
-#else
-#  define NOINLINE
-#endif
-
-
-/*
- * The following functions are called directly by process_main().
- * Don't inline them.
- */
-static void init_emulator_finish(void) NOINLINE;
-static ErtsCodeMFA *ubif2mfa(void* uf) NOINLINE;
-static ErtsCodeMFA *gcbif2mfa(void* gcf) NOINLINE;
+static void init_emulator_finish(void) ERTS_NOINLINE;
+static ErtsCodeMFA *ubif2mfa(void* uf) ERTS_NOINLINE;
 static BeamInstr* handle_error(Process* c_p, BeamInstr* pc,
-			       Eterm* reg, ErtsCodeMFA* bif_mfa) NOINLINE;
+			       Eterm* reg, ErtsCodeMFA* bif_mfa) ERTS_NOINLINE;
 static BeamInstr* call_error_handler(Process* p, ErtsCodeMFA* mfa,
-				     Eterm* reg, Eterm func) NOINLINE;
+				     Eterm* reg, Eterm func) ERTS_NOINLINE;
 static BeamInstr* fixed_apply(Process* p, Eterm* reg, Uint arity,
-			      BeamInstr *I, Uint offs) NOINLINE;
+			      BeamInstr *I, Uint offs) ERTS_NOINLINE;
 static BeamInstr* apply(Process* p, Eterm* reg,
-                        BeamInstr *I, Uint offs) NOINLINE;
+                        BeamInstr *I, Uint offs) ERTS_NOINLINE;
 static BeamInstr* call_fun(Process* p, int arity,
-			   Eterm* reg, Eterm args) NOINLINE;
+			   Eterm* reg, Eterm args) ERTS_NOINLINE;
 static BeamInstr* apply_fun(Process* p, Eterm fun,
-			    Eterm args, Eterm* reg) NOINLINE;
+			    Eterm args, Eterm* reg) ERTS_NOINLINE;
 static Eterm new_fun(Process* p, Eterm* reg,
-		     ErlFunEntry* fe, int num_free) NOINLINE;
+		     ErlFunEntry* fe, int num_free) ERTS_NOINLINE;
+static int is_function2(Eterm Term, Uint arity);
 static Eterm erts_gc_new_map(Process* p, Eterm* reg, Uint live,
-                             Uint n, BeamInstr* ptr) NOINLINE;
+                             Uint n, BeamInstr* ptr) ERTS_NOINLINE;
 static Eterm erts_gc_new_small_map_lit(Process* p, Eterm* reg, Eterm keys_literal,
-                               Uint live, BeamInstr* ptr) NOINLINE;
+                               Uint live, BeamInstr* ptr) ERTS_NOINLINE;
 static Eterm erts_gc_update_map_assoc(Process* p, Eterm* reg, Uint live,
-                              Uint n, BeamInstr* new_p) NOINLINE;
+                              Uint n, BeamInstr* new_p) ERTS_NOINLINE;
 static Eterm erts_gc_update_map_exact(Process* p, Eterm* reg, Uint live,
-                              Uint n, Eterm* new_p) NOINLINE;
+                              Uint n, Eterm* new_p) ERTS_NOINLINE;
 static Eterm get_map_element(Eterm map, Eterm key);
 static Eterm get_map_element_hash(Eterm map, Eterm key, Uint32 hx);
 
@@ -421,6 +414,7 @@ static Eterm add_stacktrace(Process* c_p, Eterm Value, Eterm exc);
 static void save_stacktrace(Process* c_p, BeamInstr* pc, Eterm* reg,
 			    ErtsCodeMFA *bif_mfa, Eterm args);
 static struct StackTrace * get_trace_from_exc(Eterm exc);
+static Eterm *get_freason_ptr_from_exc(Eterm exc);
 static Eterm make_arglist(Process* c_p, Eterm* reg, int a);
 
 void
@@ -881,19 +875,22 @@ void process_main(Eterm * x_reg_array, FloatDef* f_reg_array)
 #include "beam_warm.h"
 
  OpCase(normal_exit): {
-     SWAPOUT;
+     HEAVY_SWAPOUT;
      c_p->freason = EXC_NORMAL;
      c_p->arity = 0; /* In case this process will ever be garbed again. */
      ERTS_UNREQ_PROC_MAIN_LOCK(c_p);
      erts_do_exit_process(c_p, am_normal);
      ERTS_REQ_PROC_MAIN_LOCK(c_p);
+     HEAVY_SWAPIN;
      goto do_schedule;
  }
 
  OpCase(continue_exit): {
+     HEAVY_SWAPOUT;
      ERTS_UNREQ_PROC_MAIN_LOCK(c_p);
      erts_continue_exit_process(c_p);
      ERTS_REQ_PROC_MAIN_LOCK(c_p);
+     HEAVY_SWAPIN;
      goto do_schedule;
  }
 
@@ -1301,18 +1298,6 @@ void erts_dirty_process_main(ErtsSchedulerData *esdp)
 }
 
 static ErtsCodeMFA *
-gcbif2mfa(void* gcf)
-{
-    int i;
-    for (i = 0; erts_gc_bifs[i].bif; i++) {
-	if (erts_gc_bifs[i].gc_bif == gcf)
-	    return &bif_export[erts_gc_bifs[i].exp_ix]->info.mfa;
-    }
-    erts_exit(ERTS_ERROR_EXIT, "bad gc bif");
-    return NULL;
-}
-
-static ErtsCodeMFA *
 ubif2mfa(void* uf)
 {
     int i;
@@ -1320,7 +1305,7 @@ ubif2mfa(void* uf)
 	if (erts_u_bifs[i].bif == uf)
 	    return &bif_export[erts_u_bifs[i].exp_ix]->info.mfa;
     }
-    erts_exit(ERTS_ERROR_EXIT, "bad u bif");
+    erts_exit(ERTS_ERROR_EXIT, "bad u bif: %p\n", uf);
     return NULL;
 }
 
@@ -1484,9 +1469,24 @@ next_catch(Process* c_p, Eterm *reg) {
     BeamInstr i_return_time_trace = beam_return_time_trace[0];
 
     ptr = prev = c_p->stop;
-    ASSERT(is_CP(*ptr));
     ASSERT(ptr <= STACK_START(c_p));
-    if (ptr == STACK_START(c_p)) return NULL;
+
+    /* This function is only called if we have active catch tags or have
+     * previously called a function that was exception-traced. As the exception
+     * trace flag isn't cleared after the traced function returns (and the
+     * catch tag inserted by it is gone), it's possible to land here with an
+     * empty stack, and the process should simply die when that happens. */
+    if (ptr == STACK_START(c_p)) {
+        ASSERT(!active_catches && IS_TRACED_FL(c_p, F_EXCEPTION_TRACE));
+        return NULL;
+    }
+
+    /*
+     * Better safe than sorry here. In debug builds, produce a core
+     * dump if the top of the stack doesn't point to a continuation
+     * pointer. In other builds, ignore a non-CP at the top of stack.
+     */
+    ASSERT(is_CP(*ptr));
     if ((is_not_CP(*ptr) || (*cp_val(*ptr) != i_return_trace &&
 			     *cp_val(*ptr) != i_return_to_trace &&
 			     *cp_val(*ptr) != i_return_time_trace ))
@@ -1903,6 +1903,25 @@ static int is_raised_exc(Eterm exc) {
     }
 }
 
+static Eterm *get_freason_ptr_from_exc(Eterm exc) {
+    static Eterm dummy_freason;
+    struct StackTrace* s;
+
+    if (exc == NIL) {
+        /*
+         * Is is not exactly clear when exc can be NIL. Probably only
+         * when the exception has been generated from native code.
+         * Return a pointer to an Eterm that can be safely written and
+         * ignored.
+         */
+	return &dummy_freason;
+    } else {
+	ASSERT(is_list(exc));
+        s = (struct StackTrace *) big_val(CDR(list_val(exc)));
+        return &s->freason;
+    }
+}
+
 /*
  * Creating a list with the argument registers
  */
@@ -2315,12 +2334,16 @@ fixed_apply(Process* p, Eterm* reg, Uint arity,
     function = reg[arity+1];
 
     if (is_not_atom(function)) {
+        Eterm bad_args;
     error:
-	p->freason = BADARG;
-	reg[0] = module;
-	reg[1] = function;
-	reg[2] = NIL;
-	return 0;
+        bad_args = make_arglist(p, reg, arity);
+
+        p->freason = BADARG;
+        reg[0] = module;
+        reg[1] = function;
+        reg[2] = bad_args;
+
+        return 0;
     }
 
     if (is_not_atom(module)) goto error;
@@ -2671,6 +2694,19 @@ new_fun(Process* p, Eterm* reg, ErlFunEntry* fe, int num_free)
     return make_fun(funp);
 }
 
+static int
+is_function2(Eterm Term, Uint arity)
+{
+    if (is_fun(Term)) {
+	ErlFunThing* funp = (ErlFunThing *) fun_val(Term);
+	return funp->arity == arity;
+    } else if (is_export(Term)) {
+	Export* exp = (Export *) (export_val(Term)[1]);
+	return exp->info.mfa.arity == arity;
+    }
+    return 0;
+}
+
 static Eterm get_map_element(Eterm map, Eterm key)
 {
     Uint32 hx;
@@ -3062,12 +3098,14 @@ erts_gc_update_map_exact(Process* p, Eterm* reg, Uint live, Uint n, Eterm* new_p
     Uint need;
     flatmap_t *old_mp, *mp;
     Eterm res;
+    Eterm* old_hp;
     Eterm* hp;
     Eterm* E;
     Eterm* old_keys;
     Eterm* old_vals;
     Eterm new_key;
     Eterm map;
+    int changed = 0;
 
     n /= 2;		/* Number of values to be updated */
     ASSERT(n > 0);
@@ -3134,6 +3172,7 @@ erts_gc_update_map_exact(Process* p, Eterm* reg, Uint live, Uint n, Eterm* new_p
      * Update map, keeping the old key tuple.
      */
 
+    old_hp = p->htop;
     hp = p->htop;
     E = p->stop;
 
@@ -3156,20 +3195,26 @@ erts_gc_update_map_exact(Process* p, Eterm* reg, Uint live, Uint n, Eterm* new_p
 	    /* Not same keys */
 	    *hp++ = *old_vals;
 	} else {
-	    GET_TERM(new_p[1], *hp);
-	    hp++;
-	    n--;
+            GET_TERM(new_p[1], *hp);
+            if(*hp != *old_vals) changed = 1;
+            hp++;
+            n--;
 	    if (n == 0) {
-		/*
-		 * All updates done. Copy remaining values
-		 * and return the result.
-		 */
-		for (i++, old_vals++; i < num_old; i++) {
-		    *hp++ = *old_vals++;
-		}
-		ASSERT(hp == p->htop + need);
-		p->htop = hp;
-		return res;
+                /*
+                * All updates done. Copy remaining values
+                * if any changed or return the original one.
+                */
+                if(changed) {
+		    for (i++, old_vals++; i < num_old; i++) {
+		        *hp++ = *old_vals++;
+		    }
+		    ASSERT(hp == p->htop + need);
+		    p->htop = hp;
+		    return res;
+                } else {
+                    p->htop = old_hp;
+                    return map;
+                }
 	    } else {
 		new_p += 2;
 		GET_TERM(*new_p, new_key);
@@ -3231,20 +3276,23 @@ erts_is_builtin(Eterm Mod, Eterm Name, int arity)
 
 
 /*
- * Return the current number of reductions for the given process.
+ * Return the current number of reductions consumed by the given process.
  * To get the total number of reductions, p->reds must be added.
  */
 
 Uint
-erts_current_reductions(Process *current, Process *p)
+erts_current_reductions(Process *c_p, Process *p)
 {
-    if (current != p) {
+    Sint reds_left;
+    if (c_p != p || !(erts_atomic32_read_nob(&c_p->state)
+                      & ERTS_PSFLG_RUNNING)) {
 	return 0;
-    } else if (current->fcalls < 0 && ERTS_PROC_GET_SAVED_CALLS_BUF(current)) {
-	return current->fcalls + CONTEXT_REDS;
+    } else if (c_p->fcalls < 0 && ERTS_PROC_GET_SAVED_CALLS_BUF(c_p)) {
+	reds_left = c_p->fcalls + CONTEXT_REDS;
     } else {
-	return REDS_IN(current) - current->fcalls;
+        reds_left = c_p->fcalls;
     }
+    return REDS_IN(c_p) - reds_left - erts_proc_sched_data(p)->virtual_reds;
 }
 
 int
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index e61199a8fd..35f2ea6688 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -492,6 +492,11 @@ typedef struct LoaderState {
 			   (Genop)->arity * sizeof(GenOpArg)); \
   } while (0)
 
+#define GENOP_NAME_ARITY(Genop, Name, Arity)    \
+  do {                                          \
+    (Genop)->op = genop_##Name##_##Arity;       \
+    (Genop)->arity = Arity;                     \
+  } while (0)
 
 static void free_loader_state(Binary* magic);
 static ErlHeapFragment* new_literal_fragment(Uint size);
@@ -1425,7 +1430,7 @@ load_atom_table(LoaderState* stp, ErtsAtomEncoding enc)
 	ap = atom_tab(atom_val(stp->atom[1]));
 	sys_memcpy(sbuf, ap->name, ap->len);
 	sbuf[ap->len] = '\0';
-	LoadError1(stp, "module name in object code is %s", sbuf);
+	LoadError1(stp, "BEAM file exists but it defines a module named %s", sbuf);
     }
 
     return 1;
@@ -2868,6 +2873,7 @@ load_code(LoaderState* stp)
 	    break;
 	case op_bs_put_string_WW:
 	case op_i_bs_match_string_xfWW:
+	case op_i_bs_match_string_yfWW:
 	    new_string_patch(stp, ci-1);
 	    break;
 
@@ -2969,6 +2975,8 @@ load_code(LoaderState* stp)
 #define succ(St, X, Y) ((X).type == (Y).type && (X).val + 1 == (Y).val)
 #define succ2(St, X, Y) ((X).type == (Y).type && (X).val + 2 == (Y).val)
 #define succ3(St, X, Y) ((X).type == (Y).type && (X).val + 3 == (Y).val)
+#define succ4(St, X, Y) ((X).type == (Y).type && (X).val + 4 == (Y).val)
+
 
 #ifdef NO_FPE_SIGNALS 
 #define no_fpe_signals(St) 1
@@ -2985,6 +2993,35 @@ compiled_with_otp_20_or_higher(LoaderState* stp)
 }
 
 /*
+ * Predicate that tests whether the following two moves are independent:
+ *
+ *    move Src1 Dst1
+ *    move Src2 Dst2
+ *
+ */
+static int
+independent_moves(LoaderState* stp, GenOpArg Src1, GenOpArg Dst1,
+                  GenOpArg Src2, GenOpArg Dst2)
+{
+    return (Src1.type != Dst2.type || Src1.val != Dst2.val) &&
+        (Src2.type != Dst1.type || Src2.val != Dst1.val) &&
+        (Dst1.type != Dst2.type ||Dst1.val != Dst2.val);
+}
+
+/*
+ * Predicate that tests that two registers are distinct.
+ *
+ *    move Src1 Dst1
+ *    move Src2 Dst2
+ *
+ */
+static int
+distinct(LoaderState* stp, GenOpArg Reg1, GenOpArg Reg2)
+{
+    return Reg1.type != Reg2.type || Reg1.val != Reg2.val;
+}
+
+/*
  * Predicate that tests whether a jump table can be used.
  */
 
@@ -3108,6 +3145,42 @@ is_killed(LoaderState* stp, GenOpArg Reg, GenOpArg Live)
 	Live.val <= Reg.val;
 }
 
+static int
+is_killed_by_call_fun(LoaderState* stp, GenOpArg Reg, GenOpArg Live)
+{
+    return Reg.type == TAG_x && Live.type == TAG_u &&
+	Live.val+1 <= Reg.val;
+}
+
+/*
+ * Test whether register Reg is killed by make_fun instruction that
+ * creates the fun given by index idx.
+ */
+
+static int
+is_killed_by_make_fun(LoaderState* stp, GenOpArg Reg, GenOpArg idx)
+{
+    Uint num_free;
+
+    if (idx.val >= stp->num_lambdas) {
+        /* Invalid index. Ignore the error for now. */
+        return 0;
+    } else {
+        num_free = stp->lambdas[idx.val].num_free;
+        return Reg.type == TAG_x && num_free <= Reg.val;
+    }
+}
+
+/*
+ * Test whether register Reg is killed by the send instruction that follows.
+ */
+
+static int
+is_killed_by_send(LoaderState* stp, GenOpArg Reg)
+{
+    return Reg.type == TAG_x && 2 <= Reg.val;
+}
+
 /*
  * Generate an instruction for element/2.
  */
@@ -3119,20 +3192,19 @@ gen_element(LoaderState* stp, GenOpArg Fail, GenOpArg Index,
     GenOp* op;
 
     NEW_GENOP(stp, op);
-    op->arity = 4;
     op->next = NULL;
 
     if (Index.type == TAG_i && Index.val > 0 &&
         Index.val <= ERTS_MAX_TUPLE_SIZE &&
 	(Tuple.type == TAG_x || Tuple.type == TAG_y)) {
-	op->op = genop_i_fast_element_4;
+	GENOP_NAME_ARITY(op, i_fast_element, 4);
 	op->a[0] = Tuple;
 	op->a[1] = Fail;
 	op->a[2].type = TAG_u;
 	op->a[2].val = Index.val;
 	op->a[3] = Dst;
     } else {
-	op->op = genop_i_element_4;
+        GENOP_NAME_ARITY(op, i_element, 4);
 	op->a[0] = Tuple;
 	op->a[1] = Fail;
 	op->a[2] = Index;
@@ -3148,8 +3220,7 @@ gen_bs_save(LoaderState* stp, GenOpArg Reg, GenOpArg Index)
     GenOp* op;
 
     NEW_GENOP(stp, op);
-    op->op = genop_i_bs_save2_2;
-    op->arity = 2;
+    GENOP_NAME_ARITY(op, i_bs_save2, 2);
     op->a[0] = Reg;
     op->a[1] = Index;
     if (Index.type == TAG_u) {
@@ -3168,8 +3239,7 @@ gen_bs_restore(LoaderState* stp, GenOpArg Reg, GenOpArg Index)
     GenOp* op;
 
     NEW_GENOP(stp, op);
-    op->op = genop_i_bs_restore2_2;
-    op->arity = 2;
+    GENOP_NAME_ARITY(op, i_bs_restore2, 2);
     op->a[0] = Reg;
     op->a[1] = Index;
     if (Index.type == TAG_u) {
@@ -3203,21 +3273,18 @@ gen_get_integer2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
 	} else if ((Flags.val & BSF_SIGNED) != 0) {
 	    goto generic;
 	} else if (bits == 8) {
-	    op->op = genop_i_bs_get_integer_8_3;
-	    op->arity = 3;
-	    op->a[0] = Ms;
+	    GENOP_NAME_ARITY(op, i_bs_get_integer_8, 3);
+            op->a[0] = Ms;
 	    op->a[1] = Fail;
 	    op->a[2] = Dst;
 	} else if (bits == 16 && (Flags.val & BSF_LITTLE) == 0) {
-	    op->op = genop_i_bs_get_integer_16_3;
-	    op->arity = 3;
+	    GENOP_NAME_ARITY(op, i_bs_get_integer_16, 3);
 	    op->a[0] = Ms;
 	    op->a[1] = Fail;
 	    op->a[2] = Dst;
 #ifdef ARCH_64
 	} else if (bits == 32 && (Flags.val & BSF_LITTLE) == 0) {
-	    op->op = genop_i_bs_get_integer_32_3;
-	    op->arity = 3;
+	    GENOP_NAME_ARITY(op, i_bs_get_integer_32, 3);
 	    op->a[0] = Ms;
 	    op->a[1] = Fail;
 	    op->a[2] = Dst;
@@ -3225,8 +3292,7 @@ gen_get_integer2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
 	} else {
 	generic:
 	    if (bits < SMALL_BITS) {
-		op->op = genop_i_bs_get_integer_small_imm_5;
-		op->arity = 5;
+		GENOP_NAME_ARITY(op, i_bs_get_integer_small_imm, 5);
 		op->a[0] = Ms;
 		op->a[1].type = TAG_u;
 		op->a[1].val = bits;
@@ -3234,8 +3300,7 @@ gen_get_integer2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
 		op->a[3] = Flags;
 		op->a[4] = Dst;
 	    } else {
-		op->op = genop_i_bs_get_integer_imm_6;
-		op->arity = 6;
+		GENOP_NAME_ARITY(op, i_bs_get_integer_imm, 6);
 		op->a[0] = Ms;
 		op->a[1].type = TAG_u;
 		op->a[1].val = bits;
@@ -3251,8 +3316,7 @@ gen_get_integer2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
 
 	if (!term_to_Uint(big, &bigval)) {
 	error:
-	    op->op = genop_jump_1;
-	    op->arity = 1;
+	    GENOP_NAME_ARITY(op, jump, 1);
 	    op->a[0] = Fail;
 	} else {
 	    if (!safe_mul(bigval, Unit.val, &bits)) {
@@ -3261,13 +3325,12 @@ gen_get_integer2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
 	    goto generic;
 	}
     } else {
-	op->op = genop_i_bs_get_integer_6;
-	op->arity = 6;
-	op->a[0] = Fail;
-	op->a[1] = Live;
-	op->a[2].type = TAG_u;
-	op->a[2].val = (Unit.val << 3) | Flags.val;
-	op->a[3] = Ms;
+	GENOP_NAME_ARITY(op, i_bs_get_integer, 6);
+	op->a[0] = Ms;
+	op->a[1] = Fail;
+	op->a[2] = Live;
+	op->a[3].type = TAG_u;
+	op->a[3].val = (Unit.val << 3) | Flags.val;
 	op->a[4] = Size;
 	op->a[5] = Dst;
 	op->next = NULL;
@@ -3291,26 +3354,16 @@ gen_get_binary2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
 
     NATIVE_ENDIAN(Flags);
     if (Size.type == TAG_a && Size.val == am_all) {
-	if (Ms.type == Dst.type && Ms.val == Dst.val) {
-	    op->op = genop_i_bs_get_binary_all_reuse_3;
-	    op->arity = 3;
-	    op->a[0] = Ms;
-	    op->a[1] = Fail;
-	    op->a[2] = Unit;
-	} else {
-	    op->op = genop_i_bs_get_binary_all2_5;
-	    op->arity = 5;
-	    op->a[0] = Fail;
-	    op->a[1] = Ms;
-	    op->a[2] = Live;	
-	    op->a[3] = Unit;
-	    op->a[4] = Dst;
-	}
+	GENOP_NAME_ARITY(op, i_bs_get_binary_all2, 5);
+	op->a[0] = Ms;
+	op->a[1] = Fail;
+	op->a[2] = Live;
+	op->a[3] = Unit;
+	op->a[4] = Dst;
     } else if (Size.type == TAG_i) {
-	op->op = genop_i_bs_get_binary_imm2_6;
-	op->arity = 6;
-	op->a[0] = Fail;
-	op->a[1] = Ms;
+	GENOP_NAME_ARITY(op, i_bs_get_binary_imm2, 6);
+	op->a[0] = Ms;
+	op->a[1] = Fail;
 	op->a[2] = Live;
 	op->a[3].type = TAG_u;
 	if (!safe_mul(Size.val, Unit.val, &op->a[3].val)) {
@@ -3324,14 +3377,12 @@ gen_get_binary2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
 
 	if (!term_to_Uint(big, &bigval)) {
 	error:
-	    op->op = genop_jump_1;
-	    op->arity = 1;
+	    GENOP_NAME_ARITY(op, jump, 1);
 	    op->a[0] = Fail;
 	} else {
-	    op->op = genop_i_bs_get_binary_imm2_6;
-	    op->arity = 6;
-	    op->a[0] = Fail;
-	    op->a[1] = Ms;
+	    GENOP_NAME_ARITY(op, i_bs_get_binary_imm2, 6);
+	    op->a[0] = Ms;
+	    op->a[1] = Fail;
 	    op->a[2] = Live;
 	    op->a[3].type = TAG_u;
 	    if (!safe_mul(bigval, Unit.val, &op->a[3].val)) {
@@ -3341,10 +3392,9 @@ gen_get_binary2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
 	    op->a[5] = Dst;
 	}
     } else {
-	op->op = genop_i_bs_get_binary2_6;
-	op->arity = 6;
-	op->a[0] = Fail;
-	op->a[1] = Ms;
+	GENOP_NAME_ARITY(op, i_bs_get_binary2, 6);
+	op->a[0] = Ms;
+	op->a[1] = Fail;
 	op->a[2] = Live;
 	op->a[3] = Size;
 	op->a[4].type = TAG_u;
@@ -3375,26 +3425,44 @@ gen_put_binary(LoaderState* stp, GenOpArg Fail,GenOpArg Size,
 
     NATIVE_ENDIAN(Flags);
     if (Size.type == TAG_a && Size.val == am_all) {
-	op->op = genop_i_new_bs_put_binary_all_3;
-	op->arity = 3;
-	op->a[0] = Fail;
-	op->a[1] = Src;
+	GENOP_NAME_ARITY(op, i_new_bs_put_binary_all, 3);
+	op->a[0] = Src;
+	op->a[1] = Fail;
 	op->a[2] = Unit;
     } else if (Size.type == TAG_i) {
-	op->op = genop_i_new_bs_put_binary_imm_3;
-	op->arity = 3;
+	GENOP_NAME_ARITY(op, i_new_bs_put_binary_imm, 3);
 	op->a[0] = Fail;
 	op->a[1].type = TAG_u;
 	if (safe_mul(Size.val, Unit.val, &op->a[1].val)) {
 	    op->a[2] = Src;
 	} else {
-	    op->op = genop_badarg_1;
-	    op->arity = 1;
+        error:
+            GENOP_NAME_ARITY(op, badarg, 1);
 	    op->a[0] = Fail;
 	}
+    } else if (Size.type == TAG_q) {
+#ifdef ARCH_64
+        /*
+         * There is no way that this binary would fit in memory.
+         */
+        goto error;
+#else
+	Eterm big = stp->literals[Size.val].term;
+	Uint bigval;
+        Uint size;
+
+	if (!term_to_Uint(big, &bigval) ||
+            !safe_mul(bigval, Unit.val, &size)) {
+	    goto error;
+	}
+        GENOP_NAME_ARITY(op, i_new_bs_put_binary_imm, 3);
+        op->a[0] = Fail;
+        op->a[1].type = TAG_u;
+        op->a[1].val = size;
+        op->a[2] = Src;
+#endif
     } else {
-	op->op = genop_i_new_bs_put_binary_4;
-	op->arity = 4;
+	GENOP_NAME_ARITY(op, i_new_bs_put_binary, 4);
 	op->a[0] = Fail;
 	op->a[1] = Size;
 	op->a[2].type = TAG_u;
@@ -3416,41 +3484,39 @@ gen_put_integer(LoaderState* stp, GenOpArg Fail, GenOpArg Size,
     NATIVE_ENDIAN(Flags);
 	/* Negative size must fail */
     if (Size.type == TAG_i) {
-	op->op = genop_i_new_bs_put_integer_imm_4;
-	op->arity = 4;
-	op->a[0] = Fail;
-	op->a[1].type = TAG_u;
-	if (!safe_mul(Size.val, Unit.val, &op->a[1].val)) {
+        Uint size;
+	if (!safe_mul(Size.val, Unit.val, &size)) {
         error:
-            op->op = genop_badarg_1;
-            op->arity = 1;
+            GENOP_NAME_ARITY(op, badarg, 1);
             op->a[0] = Fail;
             op->next = NULL;
             return op;
 	}
-	op->a[1].val = Size.val * Unit.val;
-	op->a[2].type = Flags.type;
-	op->a[2].val = (Flags.val & 7);
-	op->a[3] = Src;
+	GENOP_NAME_ARITY(op, i_new_bs_put_integer_imm, 4);
+	op->a[0] = Src;
+	op->a[1] = Fail;
+	op->a[2].type = TAG_u;
+	op->a[2].val = size;
+	op->a[3].type = Flags.type;
+	op->a[3].val = (Flags.val & 7);
     } else if (Size.type == TAG_q) {
 	Eterm big = stp->literals[Size.val].term;
 	Uint bigval;
+        Uint size;
 
-	if (!term_to_Uint(big, &bigval)) {
+	if (!term_to_Uint(big, &bigval) ||
+            !safe_mul(bigval, Unit.val, &size)) {
 	    goto error;
-	} else {
-	    op->op = genop_i_new_bs_put_integer_imm_4;
-	    op->arity = 4;
-	    op->a[0] = Fail;
-	    op->a[1].type = TAG_u;
-	    op->a[1].val = bigval * Unit.val;
-	    op->a[2].type = Flags.type;
-	    op->a[2].val = (Flags.val & 7);
-	    op->a[3] = Src;
 	}
+	GENOP_NAME_ARITY(op, i_new_bs_put_integer_imm, 4);
+	op->a[0] = Src;
+	op->a[1] = Fail;
+	op->a[2].type = TAG_u;
+	op->a[2].val = size;
+	op->a[3].type = Flags.type;
+	op->a[3].val = (Flags.val & 7);
     } else {
-	op->op = genop_i_new_bs_put_integer_4;
-	op->arity = 4;
+	GENOP_NAME_ARITY(op, i_new_bs_put_integer, 4);
 	op->a[0] = Fail;
 	op->a[1] = Size;
 	op->a[2].type = TAG_u;
@@ -3470,21 +3536,18 @@ gen_put_float(LoaderState* stp, GenOpArg Fail, GenOpArg Size,
 
     NATIVE_ENDIAN(Flags);
     if (Size.type == TAG_i) {
-	op->op = genop_i_new_bs_put_float_imm_4;
-	op->arity = 4;
+	GENOP_NAME_ARITY(op, i_new_bs_put_float_imm, 4);
 	op->a[0] = Fail;
 	op->a[1].type = TAG_u;
 	if (!safe_mul(Size.val, Unit.val, &op->a[1].val)) {
-	    op->op = genop_badarg_1;
-	    op->arity = 1;
+	    GENOP_NAME_ARITY(op, badarg, 1);
 	    op->a[0] = Fail;
 	} else {
 	    op->a[2] = Flags;
 	    op->a[3] = Src;
 	}
     } else {
-	op->op = genop_i_new_bs_put_float_4;
-	op->arity = 4;
+	GENOP_NAME_ARITY(op, i_new_bs_put_float, 4);
 	op->a[0] = Fail;
 	op->a[1] = Size;
 	op->a[2].type = TAG_u;
@@ -3507,10 +3570,9 @@ gen_get_float2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
     NEW_GENOP(stp, op);
 
     NATIVE_ENDIAN(Flags);
-    op->op = genop_i_bs_get_float2_6;
-    op->arity = 6;
-    op->a[0] = Fail;
-    op->a[1] = Ms;
+    GENOP_NAME_ARITY(op, i_bs_get_float2, 6);
+    op->a[0] = Ms;
+    op->a[1] = Fail;
     op->a[2] = Live;
     op->a[3] = Size;
     op->a[4].type = TAG_u;
@@ -3525,7 +3587,7 @@ gen_get_float2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, GenOpArg Live,
  */
 
 static GenOp*
-gen_skip_bits2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms, 
+gen_skip_bits2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms,
 	       GenOpArg Size, GenOpArg Unit, GenOpArg Flags)
 {
     GenOp* op;
@@ -3533,16 +3595,26 @@ gen_skip_bits2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms,
     NATIVE_ENDIAN(Flags);
     NEW_GENOP(stp, op);
     if (Size.type == TAG_a && Size.val == am_all) {
-	op->op = genop_i_bs_skip_bits_all2_3;
-	op->arity = 3;
+        /*
+         * This kind of skip instruction will only be found in modules
+         * compiled before OTP 19. From OTP 19, the compiler generates
+         * a test_unit instruction of a bs_skip at the end of a
+         * binary.
+         *
+         * It is safe to replace the skip instruction with a test_unit
+         * instruction, because the position will never be used again.
+         * If the match context itself is used again, it will be used by
+         * a bs_restore2 instruction which will overwrite the position
+         * by one of the stored positions.
+         */
+	GENOP_NAME_ARITY(op, bs_test_unit, 3);
 	op->a[0] = Fail;
-	op->a[1] = Ms; 
+	op->a[1] = Ms;
 	op->a[2] = Unit;
     } else if (Size.type == TAG_i) {
-	op->op = genop_i_bs_skip_bits_imm2_3;
-	op->arity = 3;
+	GENOP_NAME_ARITY(op, i_bs_skip_bits_imm2, 3);
 	op->a[0] = Fail;
-	op->a[1] = Ms; 
+	op->a[1] = Ms;
 	op->a[2].type = TAG_u;
 	if (!safe_mul(Size.val, Unit.val, &op->a[2].val)) {
 	    goto error;
@@ -3553,25 +3625,22 @@ gen_skip_bits2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms,
 
 	if (!term_to_Uint(big, &bigval)) {
 	error:
-	    op->op = genop_jump_1;
-	    op->arity = 1;
+	    GENOP_NAME_ARITY(op, jump, 1);
 	    op->a[0] = Fail;
 	} else {
-	    op->op = genop_i_bs_skip_bits_imm2_3;
-	    op->arity = 3;
+	    GENOP_NAME_ARITY(op, i_bs_skip_bits_imm2, 3);
 	    op->a[0] = Fail;
-	    op->a[1] = Ms; 
+	    op->a[1] = Ms;
 	    op->a[2].type = TAG_u;
 	    if (!safe_mul(bigval, Unit.val, &op->a[2].val)) {
 		goto error;
 	    }
 	}
     } else {
-	op->op = genop_i_bs_skip_bits2_4;
-	op->arity = 4;
-	op->a[0] = Fail;
-	op->a[1] = Ms; 
-	op->a[2] = Size;
+	GENOP_NAME_ARITY(op, i_bs_skip_bits2, 4);
+	op->a[0] = Ms;
+	op->a[1] = Size;
+	op->a[2] = Fail;
 	op->a[3] = Unit;
     }
     op->next = NULL;
@@ -3579,38 +3648,52 @@ gen_skip_bits2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms,
 }
 
 static GenOp*
-gen_increment(LoaderState* stp, GenOpArg Reg, GenOpArg Integer,
-	      GenOpArg Live, GenOpArg Dst)
+gen_increment(LoaderState* stp, GenOpArg Reg,
+              GenOpArg Integer, GenOpArg Dst)
 {
     GenOp* op;
 
     NEW_GENOP(stp, op);
-    op->op = genop_i_increment_4;
-    op->arity = 4;
+    GENOP_NAME_ARITY(op, i_increment, 3);
     op->next = NULL;
     op->a[0] = Reg;
     op->a[1].type = TAG_u;
     op->a[1].val = Integer.val;
-    op->a[2] = Live;
-    op->a[3] = Dst;
+    op->a[2] = Dst;
     return op;
 }
 
 static GenOp*
-gen_increment_from_minus(LoaderState* stp, GenOpArg Reg, GenOpArg Integer,
-			 GenOpArg Live, GenOpArg Dst)
+gen_increment_from_minus(LoaderState* stp, GenOpArg Reg,
+                         GenOpArg Integer, GenOpArg Dst)
 {
     GenOp* op;
 
     NEW_GENOP(stp, op);
-    op->op = genop_i_increment_4;
-    op->arity = 4;
+    GENOP_NAME_ARITY(op, i_increment, 3);
     op->next = NULL;
     op->a[0] = Reg;
     op->a[1].type = TAG_u;
     op->a[1].val = -Integer.val;
-    op->a[2] = Live;
-    op->a[3] = Dst;
+    op->a[2] = Dst;
+    return op;
+}
+
+static GenOp*
+gen_plus_from_minus(LoaderState* stp, GenOpArg Fail, GenOpArg Live,
+                    GenOpArg Src, GenOpArg Integer, GenOpArg Dst)
+{
+    GenOp* op;
+
+    NEW_GENOP(stp, op);
+    GENOP_NAME_ARITY(op, gen_plus, 5);
+    op->next = NULL;
+    op->a[0] = Fail;
+    op->a[1] = Live;
+    op->a[2] = Src;
+    op->a[3].type = TAG_i;
+    op->a[3].val = -Integer.val;
+    op->a[4] = Dst;
     return op;
 }
 
@@ -3660,12 +3743,11 @@ gen_literal_timeout(LoaderState* stp, GenOpArg Fail, GenOpArg Time)
     Sint timeout;
 
     NEW_GENOP(stp, op);
-    op->op = genop_wait_timeout_unlocked_int_2;
+    GENOP_NAME_ARITY(op, wait_timeout_unlocked_int, 2);
     op->next = NULL;
-    op->arity = 2;
     op->a[0].type = TAG_u;
     op->a[1] = Fail;
-    
+
     if (Time.type == TAG_i && (timeout = Time.val) >= 0 &&
 #if defined(ARCH_64)
 	(timeout >> 32) == 0
@@ -3694,8 +3776,7 @@ gen_literal_timeout(LoaderState* stp, GenOpArg Fail, GenOpArg Time)
 #if !defined(ARCH_64)
     error:
 #endif
-	op->op = genop_i_wait_error_0;
-	op->arity = 0;
+	GENOP_NAME_ARITY(op, i_wait_error, 0);
     }
     return op;
 }
@@ -3707,9 +3788,8 @@ gen_literal_timeout_locked(LoaderState* stp, GenOpArg Fail, GenOpArg Time)
     Sint timeout;
 
     NEW_GENOP(stp, op);
-    op->op = genop_wait_timeout_locked_int_2;
+    GENOP_NAME_ARITY(op, wait_timeout_locked_int, 2);
     op->next = NULL;
-    op->arity = 2;
     op->a[0].type = TAG_u;
     op->a[1] = Fail;
 
@@ -3741,8 +3821,7 @@ gen_literal_timeout_locked(LoaderState* stp, GenOpArg Fail, GenOpArg Time)
 #if !defined(ARCH_64)
     error:
 #endif
-	op->op = genop_i_wait_error_locked_0;
-	op->arity = 0;
+        GENOP_NAME_ARITY(op, i_wait_error_locked, 0);
     }
     return op;
 }
@@ -3779,9 +3858,9 @@ gen_select_tuple_arity(LoaderState* stp, GenOpArg S, GenOpArg Fail,
      */
     if (size == 2) {
 	NEW_GENOP(stp, op);
-	op->next = NULL;
-	op->op = genop_i_select_tuple_arity2_4;
+	GENOP_NAME_ARITY(op, i_select_tuple_arity2, 4);
 	GENOP_ARITY(op, arity - 1);
+	op->next = NULL;
 	op->a[0] = S;
 	op->a[1] = Fail;
 	op->a[2].type = TAG_u;
@@ -3807,9 +3886,9 @@ gen_select_tuple_arity(LoaderState* stp, GenOpArg S, GenOpArg Fail,
     size  += align;
 
     NEW_GENOP(stp, op);
-    op->next = NULL;
-    op->op = genop_i_select_tuple_arity_3;
+    GENOP_NAME_ARITY(op, i_select_tuple_arity, 3);
     GENOP_ARITY(op, arity);
+    op->next = NULL;
     op->a[0] = S;
     op->a[1] = Fail;
     op->a[2].type = TAG_u;
@@ -3865,21 +3944,18 @@ gen_split_values(LoaderState* stp, GenOpArg S, GenOpArg TypeFail,
     ASSERT(Size.val >= 2 && Size.val % 2 == 0);
 
     NEW_GENOP(stp, is_integer);
-    is_integer->op = genop_is_integer_2;
-    is_integer->arity = 2;
+    GENOP_NAME_ARITY(is_integer, is_integer, 2);
     is_integer->a[0] = TypeFail;
     is_integer->a[1] = S;
 
     NEW_GENOP(stp, label);
-    label->op = genop_label_1;
-    label->arity = 1;
+    GENOP_NAME_ARITY(label, label, 1);
     label->a[0].type = TAG_u;
     label->a[0].val = new_label(stp);
 
     NEW_GENOP(stp, op1);
-    op1->op = genop_select_val_3;
+    GENOP_NAME_ARITY(op1, select_val, 3);
     GENOP_ARITY(op1, 3 + Size.val);
-    op1->arity = 3;
     op1->a[0] = S;
     op1->a[1].type = TAG_f;
     op1->a[1].val = label->a[0].val;
@@ -3887,9 +3963,8 @@ gen_split_values(LoaderState* stp, GenOpArg S, GenOpArg TypeFail,
     op1->a[2].val = 0;
 
     NEW_GENOP(stp, op2);
-    op2->op = genop_select_val_3;
+    GENOP_NAME_ARITY(op2, select_val, 3);
     GENOP_ARITY(op2, 3 + Size.val);
-    op2->arity = 3;
     op2->a[0] = S;
     op2->a[1] = Fail;
     op2->a[2].type = TAG_u;
@@ -3967,19 +4042,17 @@ gen_jump_tab(LoaderState* stp, GenOpArg S, GenOpArg Fail, GenOpArg Size, GenOpAr
 	GenOp* jump;
 
 	NEW_GENOP(stp, op);
-	op->arity = 3;
-	op->op = genop_is_ne_exact_3;
+	GENOP_NAME_ARITY(op, is_ne_exact, 3);
 	op->a[0] = Rest[1];
 	op->a[1] = S;
 	op->a[2] = Rest[0];
 
 	NEW_GENOP(stp, jump);
-	jump->next = NULL;
-	jump->arity = 1;
-	jump->op = genop_jump_1;
+        GENOP_NAME_ARITY(jump, jump, 1);
 	jump->a[0] = Fail;
 
 	op->next = jump;
+	jump->next = NULL;
 	return op;
     }
 
@@ -4006,12 +4079,11 @@ gen_jump_tab(LoaderState* stp, GenOpArg S, GenOpArg Fail, GenOpArg Size, GenOpAr
     NEW_GENOP(stp, op);
     op->next = NULL;
     if (min == 0) {
-	op->op = genop_i_jump_on_val_zero_3;
-	fixed_args = 3;
+	GENOP_NAME_ARITY(op, i_jump_on_val_zero, 3);
     } else {
-	op->op = genop_i_jump_on_val_4;
-	fixed_args = 4;
+	GENOP_NAME_ARITY(op, i_jump_on_val, 4);
     }
+    fixed_args = op->arity;
     arity = fixed_args + size;
     GENOP_ARITY(op, arity);
     op->a[0] = S;
@@ -4076,7 +4148,7 @@ gen_select_val(LoaderState* stp, GenOpArg S, GenOpArg Fail,
 
 	NEW_GENOP(stp, op);
 	op->next = NULL;
-	op->op = genop_i_select_val2_4;
+        GENOP_NAME_ARITY(op, i_select_val2, 4);
 	GENOP_ARITY(op, arity - 1);
 	op->a[0] = S;
 	op->a[1] = Fail;
@@ -4098,7 +4170,11 @@ gen_select_val(LoaderState* stp, GenOpArg S, GenOpArg Fail,
 
     NEW_GENOP(stp, op);
     op->next = NULL;
-    op->op = (align == 0) ? genop_i_select_val_bins_3 : genop_i_select_val_lins_3;
+    if (align == 0) {
+        GENOP_NAME_ARITY(op, i_select_val_bins, 3);
+    } else {
+        GENOP_NAME_ARITY(op, i_select_val_lins, 3);
+    }
     GENOP_ARITY(op, arity);
     op->a[0] = S;
     op->a[1] = Fail;
@@ -4162,8 +4238,7 @@ gen_select_literals(LoaderState* stp, GenOpArg S, GenOpArg Fail,
 	ASSERT(Rest[i].type == TAG_q);
 
 	NEW_GENOP(stp, op);
-	op->op = genop_is_ne_exact_3;
-	op->arity = 3;
+	GENOP_NAME_ARITY(op, is_ne_exact, 3);
 	op->a[0] = Rest[i+1];
 	op->a[1] = S;
 	op->a[2] = Rest[i];
@@ -4172,9 +4247,8 @@ gen_select_literals(LoaderState* stp, GenOpArg S, GenOpArg Fail,
     }
 
     NEW_GENOP(stp, jump);
+    GENOP_NAME_ARITY(jump, jump, 1);
     jump->next = NULL;
-    jump->op = genop_jump_1;
-    jump->arity = 1;
     jump->a[0] = Fail;
     *prev_next = jump;
     return op;
@@ -4196,9 +4270,8 @@ const_select_val(LoaderState* stp, GenOpArg S, GenOpArg Fail,
     ASSERT(Size.type == TAG_u);
 
     NEW_GENOP(stp, op);
+    GENOP_NAME_ARITY(op, jump, 1);
     op->next = NULL;
-    op->op = genop_jump_1;
-    op->arity = 1;
 
     /*
      * Search for a literal matching the controlling expression.
@@ -4245,115 +4318,120 @@ gen_make_fun2(LoaderState* stp, GenOpArg idx)
 {
     ErlFunEntry* fe;
     GenOp* op;
+    Uint arity, num_free;
 
     if (idx.val >= stp->num_lambdas) {
-	stp->lambda_error = "missing or short chunk 'FunT'";
-	fe = 0;
+        stp->lambda_error = "missing or short chunk 'FunT'";
+        fe = 0;
+        num_free = 0;
+        arity = 0;
     } else {
-	fe = stp->lambdas[idx.val].fe;
+        fe = stp->lambdas[idx.val].fe;
+        num_free = stp->lambdas[idx.val].num_free;
+        arity = fe->arity;
     }
 
     NEW_GENOP(stp, op);
-    op->op = genop_i_make_fun_2;
-    op->arity = 2;
-    op->a[0].type = TAG_u;
-    op->a[0].val = (BeamInstr) fe;
-    op->a[1].type = TAG_u;
-    op->a[1].val = stp->lambdas[idx.val].num_free;
-    op->next = NULL;
-    return op;
-}
 
-static GenOp*
-translate_gc_bif(LoaderState* stp, GenOp* op, GenOpArg Bif)
-{
-    const ErtsGcBif* p;
-    BifFunction bf;
-
-    bf = stp->import[Bif.val].bf;
-    for (p = erts_gc_bifs; p->bif != 0; p++) {
-	if (p->bif == bf) {
-	    op->a[1].type = TAG_u;
-	    op->a[1].val = (BeamInstr) p->gc_bif;
-	    return op;
-	}
+    /*
+     * It's possible this is called before init process is started,
+     * skip the optimisation in such case.
+     */
+    if (num_free == 0 && erts_init_process_id != ERTS_INVALID_PID) {
+        Uint lit;
+        Eterm* hp;
+        ErlFunThing* funp;
+
+        lit = new_literal(stp, &hp, ERL_FUN_SIZE);
+        funp = (ErlFunThing *) hp;
+        erts_refc_inc(&fe->refc, 2);
+        funp->thing_word = HEADER_FUN;
+        funp->next = NULL;
+        funp->fe = fe;
+        funp->num_free = 0;
+        funp->creator = erts_init_process_id;
+        funp->arity = arity;
+
+        /*
+         * Use a move_fun/2 instruction to load the fun to enable
+         * further optimizations.
+         */
+        GENOP_NAME_ARITY(op, move_fun, 2);
+        op->a[0].type = TAG_q;
+        op->a[0].val = lit;
+        op->a[1].type = TAG_x;
+        op->a[1].val = 0;
+    } else {
+        GENOP_NAME_ARITY(op, i_make_fun, 2);
+        op->a[0].type = TAG_u;
+        op->a[0].val = (BeamInstr) fe;
+        op->a[1].type = TAG_u;
+        op->a[1].val = num_free;
     }
 
-    op->op = genop_unsupported_guard_bif_3;
-    op->arity = 3;
-    op->a[0].type = TAG_a;
-    op->a[0].val = stp->import[Bif.val].module;
-    op->a[1].type = TAG_a;
-    op->a[1].val = stp->import[Bif.val].function;
-    op->a[2].type = TAG_u;
-    op->a[2].val = stp->import[Bif.val].arity;
+    op->next = NULL;
     return op;
 }
 
-/*
- * Rewrite gc_bifs with one parameter (the common case).
- */
 static GenOp*
-gen_guard_bif1(LoaderState* stp, GenOpArg Fail, GenOpArg Live, GenOpArg Bif,
-	      GenOpArg Src, GenOpArg Dst)
+gen_is_function2(LoaderState* stp, GenOpArg Fail, GenOpArg Fun, GenOpArg Arity)
 {
     GenOp* op;
+    int literal_arity =  Arity.type == TAG_i;
+    int fun_is_reg = Fun.type == TAG_x || Fun.type == TAG_y;
 
     NEW_GENOP(stp, op);
     op->next = NULL;
-    op->op = genop_i_gc_bif1_5;
-    op->arity = 5;
-    op->a[0] = Fail;
-    /* op->a[1] is set by translate_gc_bif() */
-    op->a[2] = Src;
-    op->a[3] = Live;
-    op->a[4] = Dst;
-    return translate_gc_bif(stp, op, Bif);
-}
 
-/*
- * This is used by the ops.tab rule that rewrites gc_bifs with two parameters.
- */
-static GenOp*
-gen_guard_bif2(LoaderState* stp, GenOpArg Fail, GenOpArg Live, GenOpArg Bif,
-	      GenOpArg S1, GenOpArg S2, GenOpArg Dst)
-{
-    GenOp* op;
+    if (fun_is_reg &&literal_arity) {
+        /*
+         * Most common case. Fun in a register and arity
+         * is an integer literal.
+         */
+        if (Arity.val > MAX_ARG) {
+            /* Arity is negative or too big. */
+            GENOP_NAME_ARITY(op, jump, 1);
+            op->a[0] = Fail;
+            return op;
+        } else {
+            GENOP_NAME_ARITY(op, hot_is_function2, 3);
+            op->a[0] = Fail;
+            op->a[1] = Fun;
+            op->a[2].type = TAG_u;
+            op->a[2].val = Arity.val;
+            return op;
+        }
+    } else {
+        /*
+         * Handle extremely uncommon cases by a slower sequence.
+         */
+        GenOp* move_fun;
+        GenOp* move_arity;
 
-    NEW_GENOP(stp, op);
-    op->next = NULL;
-    op->op = genop_i_gc_bif2_6;
-    op->arity = 6;
-    op->a[0] = Fail;
-    /* op->a[1] is set by translate_gc_bif() */
-    op->a[2] = Live;
-    op->a[3] = S1;
-    op->a[4] = S2;
-    op->a[5] = Dst;
-    return translate_gc_bif(stp, op, Bif);
-}
+        NEW_GENOP(stp, move_fun);
+        NEW_GENOP(stp, move_arity);
 
-/*
- * This is used by the ops.tab rule that rewrites gc_bifs with three parameters.
- */
-static GenOp*
-gen_guard_bif3(LoaderState* stp, GenOpArg Fail, GenOpArg Live, GenOpArg Bif,
-	      GenOpArg S1, GenOpArg S2, GenOpArg S3, GenOpArg Dst)
-{
-    GenOp* op;
+        move_fun->next = move_arity;
+        move_arity->next = op;
 
-    NEW_GENOP(stp, op);
-    op->next = NULL;
-    op->op = genop_ii_gc_bif3_7;
-    op->arity = 7;
-    op->a[0] = Fail;
-    /* op->a[1] is set by translate_gc_bif() */
-    op->a[2] = Live;
-    op->a[3] = S1;
-    op->a[4] = S2;
-    op->a[5] = S3;
-    op->a[6] = Dst;
-    return translate_gc_bif(stp, op, Bif);
+        GENOP_NAME_ARITY(move_fun, move, 2);
+        move_fun->a[0] = Fun;
+        move_fun->a[1].type = TAG_x;
+        move_fun->a[1].val = 1022;
+
+        GENOP_NAME_ARITY(move_arity, move, 2);
+        move_arity->a[0] = Arity;
+        move_arity->a[1].type = TAG_x;
+        move_arity->a[1].val = 1023;
+
+        GENOP_NAME_ARITY(op, cold_is_function2, 3);
+        op->a[0] = Fail;
+        op->a[1].type = TAG_x;
+        op->a[1].val = 1022;
+        op->a[2].type = TAG_x;
+        op->a[2].val = 1023;
+        return move_fun;
+    }
 }
 
 static GenOp*
@@ -4367,8 +4445,8 @@ tuple_append_put5(LoaderState* stp, GenOpArg Arity, GenOpArg Dst,
 
     NEW_GENOP(stp, op);
     op->next = NULL;
+    GENOP_NAME_ARITY(op, i_put_tuple, 2);
     GENOP_ARITY(op, arity+2+5);
-    op->op = genop_i_put_tuple_2;
     op->a[0] = Dst;
     op->a[1].type = TAG_u;
     op->a[1].val = arity + 5;
@@ -4393,8 +4471,8 @@ tuple_append_put(LoaderState* stp, GenOpArg Arity, GenOpArg Dst,
 
     NEW_GENOP(stp, op);
     op->next = NULL;
+    GENOP_NAME_ARITY(op, i_put_tuple, 2);
     GENOP_ARITY(op, arity+2+1);
-    op->op = genop_i_put_tuple_2;
     op->a[0] = Dst;
     op->a[1].type = TAG_u;
     op->a[1].val = arity + 1;
@@ -4462,9 +4540,9 @@ gen_new_small_map_lit(LoaderState* stp, GenOpArg Dst, GenOpArg Live,
     Eterm keys;
 
     NEW_GENOP(stp, op);
+    GENOP_NAME_ARITY(op, i_new_small_map_lit, 3);
     GENOP_ARITY(op, 3 + size/2);
     op->next = NULL;
-    op->op = genop_i_new_small_map_lit_3;
 
     tmp = thp = erts_alloc(ERTS_ALC_T_LOADER_TMP, (1 + size/2) * sizeof(*tmp));
     keys = make_tuple(thp);
@@ -4522,19 +4600,6 @@ is_empty_map(LoaderState* stp, GenOpArg Lit)
 }
 
 /*
- * Predicate to test whether the given literal is an export.
- */
-static int
-literal_is_export(LoaderState* stp, GenOpArg Lit)
-{
-    Eterm term;
-
-    ASSERT(Lit.type == TAG_q);
-    term = stp->literals[Lit.val].term;
-    return is_export(term);
-}
-
-/*
  * Pseudo predicate map_key_sort that will sort the Rest operand for
  * map instructions as a side effect.
  */
@@ -4547,7 +4612,15 @@ typedef struct SortGenOpArg {
 static int
 genopargtermcompare(SortGenOpArg* a, SortGenOpArg* b)
 {
-    return CMP_TERM(a->term, b->term);
+    Sint res = CMP_TERM(a->term, b->term);
+
+    if (res < 0) {
+        return -1;
+    } else if (res > 0) {
+        return 1;
+    }
+
+    return 0;
 }
 
 static int
@@ -4658,14 +4731,12 @@ gen_get_map_element(LoaderState* stp, GenOpArg Fail, GenOpArg Src,
 
     Key = Rest[0];
     if (hash_genop_arg(stp, Key, &hx)) {
-	op->arity = 5;
-	op->op = genop_i_get_map_element_hash_5;
+	GENOP_NAME_ARITY(op, i_get_map_element_hash, 5);
 	op->a[3].type = TAG_u;
 	op->a[3].val = (BeamInstr) hx;
 	op->a[4] = Rest[1];
     } else {
-	op->arity = 4;
-	op->op = genop_i_get_map_element_4;
+	GENOP_NAME_ARITY(op, i_get_map_element, 4);
 	op->a[3] = Rest[1];
     }
     return op;
@@ -4705,15 +4776,13 @@ gen_get(LoaderState* stp, GenOpArg Src, GenOpArg Dst)
     NEW_GENOP(stp, op);
     op->next = NULL;
     if (hash_internal_genop_arg(stp, Src, &hx)) {
-	op->arity = 3;
-	op->op = genop_i_get_hash_3;
+	GENOP_NAME_ARITY(op, i_get_hash, 3);
         op->a[0] = Src;
 	op->a[1].type = TAG_u;
 	op->a[1].val = (BeamInstr) hx;
 	op->a[2] = Dst;
     } else {
-	op->arity = 2;
-	op->op = genop_i_get_2;
+	GENOP_NAME_ARITY(op, i_get, 2);
         op->a[0] = Src;
 	op->a[1] = Dst;
     }
@@ -4737,7 +4806,7 @@ gen_get_map_elements(LoaderState* stp, GenOpArg Fail, GenOpArg Src,
     ASSERT(Size.type == TAG_u);
 
     NEW_GENOP(stp, op);
-    op->op = genop_i_get_map_elements_3;
+    GENOP_NAME_ARITY(op, i_get_map_elements, 3);
     GENOP_ARITY(op, 3 + 3*(Size.val/2));
     op->next = NULL;
     op->a[0] = Fail;
@@ -4775,9 +4844,9 @@ gen_has_map_fields(LoaderState* stp, GenOpArg Fail, GenOpArg Src,
     n = Size.val;
 
     NEW_GENOP(stp, op);
+    GENOP_NAME_ARITY(op, get_map_elements, 3);
     GENOP_ARITY(op, 3 + 2*n);
     op->next = NULL;
-    op->op = genop_get_map_elements_3;
 
     op->a[0] = Fail;
     op->a[1] = Src;
@@ -6114,7 +6183,8 @@ erts_release_literal_area(ErtsLiteralArea* literal_area)
             }
         default:
             ASSERT(is_external_header(oh->thing_word));
-            erts_deref_node_entry(((ExternalThing*)oh)->node);
+            erts_deref_node_entry(((ExternalThing*)oh)->node,
+                                  make_boxed(&oh->thing_word));
         }
         oh = oh->next;
     }
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 015c051cc1..b81056c774 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -184,7 +184,7 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
         DistEntry *dep;
         ErtsLink *lnk;
         int code;
-        ErtsDSigData dsd;
+        ErtsDSigSendContext ctx;
 
         dep = external_pid_dist_entry(BIF_ARG_1);
         if (dep == erts_this_dist_entry)
@@ -201,9 +201,9 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
 
         ldp = erts_link_to_data(lnk);
 
-        code = erts_dsig_prepare(&dsd, dep, BIF_P,
+        code = erts_dsig_prepare(&ctx, dep, BIF_P,
                                  ERTS_PROC_LOCK_MAIN,
-                                 ERTS_DSP_RLOCK, 0, 1);
+                                 ERTS_DSP_RLOCK, 0, 1, 1);
         switch (code) {
         case ERTS_DSIG_PREP_NOT_ALIVE:
         case ERTS_DSIG_PREP_NOT_CONNECTED:
@@ -218,16 +218,14 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
              * We have (pending) connection.
              * Setup link and enqueue link signal.
              */
-#ifdef DEBUG
-            int inserted =
-#endif
-                erts_link_dist_insert(&ldp->b, dep->mld);
-            ASSERT(inserted);
+            int inserted = erts_link_dist_insert(&ldp->b, dep->mld);
+            ASSERT(inserted); (void)inserted;
             erts_de_runlock(dep);
 
-            code = erts_dsig_send_link(&dsd, BIF_P->common.id, BIF_ARG_1);
+            code = erts_dsig_send_link(&ctx, BIF_P->common.id, BIF_ARG_1);
             if (code == ERTS_DSIG_SEND_YIELD)
                 ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
+            ASSERT(code == ERTS_DSIG_SEND_OK);
             BIF_RET(am_true);
             break;
         }
@@ -309,7 +307,7 @@ demonitor(Process *c_p, Eterm ref, Eterm *multip)
        DistEntry *dep;
        int code = ERTS_DSIG_SEND_OK;
        int deleted;
-       ErtsDSigData dsd;
+       ErtsDSigSendContext ctx;
 
        ASSERT(is_external_pid(to) || is_node_name_atom(to));
 
@@ -325,8 +323,8 @@ demonitor(Process *c_p, Eterm ref, Eterm *multip)
            }
        }
 
-       code = erts_dsig_prepare(&dsd, dep, c_p, ERTS_PROC_LOCK_MAIN,
-                                ERTS_DSP_RLOCK, 0, 0);
+       code = erts_dsig_prepare(&ctx, dep, c_p, ERTS_PROC_LOCK_MAIN,
+                                ERTS_DSP_RLOCK, 0, 1, 0);
 
        deleted = erts_monitor_dist_delete(&mdp->target);
 
@@ -355,8 +353,8 @@ demonitor(Process *c_p, Eterm ref, Eterm *multip)
             * monitor list since in case of monitor name 
             * the atom is stored there. Yield if necessary.
             */
-           code = erts_dsig_send_demonitor(&dsd, c_p->common.id,
-                                           watched, mdp->ref, 0);
+           code = erts_dsig_send_demonitor(&ctx, c_p->common.id,
+                                           watched, mdp->ref);
            break;
        }
 
@@ -536,7 +534,7 @@ BIF_RETTYPE monitor_2(BIF_ALIST_2)
         }
 
         if (is_external_pid(target)) {
-            ErtsDSigData dsd;
+            ErtsDSigSendContext ctx;
             int code;
 
             dep = external_pid_dist_entry(target);
@@ -554,9 +552,9 @@ BIF_RETTYPE monitor_2(BIF_ALIST_2)
                                       BIF_P->common.id, id, name);
             erts_monitor_tree_insert(&ERTS_P_MONITORS(BIF_P), &mdp->origin);
 
-            code = erts_dsig_prepare(&dsd, dep,
+            code = erts_dsig_prepare(&ctx, dep,
                                      BIF_P, ERTS_PROC_LOCK_MAIN,
-                                     ERTS_DSP_RLOCK, 0, 1);
+                                     ERTS_DSP_RLOCK, 0, 1, 1);
             switch (code) {
             case ERTS_DSIG_PREP_NOT_ALIVE:
             case ERTS_DSIG_PREP_NOT_CONNECTED:
@@ -567,15 +565,11 @@ BIF_RETTYPE monitor_2(BIF_ALIST_2)
 
             case ERTS_DSIG_PREP_PENDING:
             case ERTS_DSIG_PREP_CONNECTED: {
-#ifdef DEBUG
-                int inserted =
-#endif
-
-                erts_monitor_dist_insert(&mdp->target, dep->mld);
-                ASSERT(inserted);
+                int inserted = erts_monitor_dist_insert(&mdp->target, dep->mld);
+                ASSERT(inserted); (void)inserted;
                 erts_de_runlock(dep);
 
-                code = erts_dsig_send_monitor(&dsd, BIF_P->common.id, target, ref);
+                code = erts_dsig_send_monitor(&ctx, BIF_P->common.id, target, ref);
                 break;
             }
 
@@ -921,7 +915,7 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
         ErtsLinkData *ldp;
         DistEntry *dep;
 	int code;
-	ErtsDSigData dsd;
+	ErtsDSigSendContext ctx;
 
 	dep = external_pid_dist_entry(BIF_ARG_1);
 	if (dep == erts_this_dist_entry)
@@ -939,15 +933,15 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
         else
             erts_link_release(lnk);
 
-	code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_PROC_LOCK_MAIN,
-				 ERTS_DSP_NO_LOCK, 0, 0);
+	code = erts_dsig_prepare(&ctx, dep, BIF_P, ERTS_PROC_LOCK_MAIN,
+				 ERTS_DSP_NO_LOCK, 0, 1, 0);
 	switch (code) {
 	case ERTS_DSIG_PREP_NOT_ALIVE:
 	case ERTS_DSIG_PREP_NOT_CONNECTED:
 	    BIF_RET(am_true);
 	case ERTS_DSIG_PREP_PENDING:
 	case ERTS_DSIG_PREP_CONNECTED:
-	    code = erts_dsig_send_unlink(&dsd, BIF_P->common.id, BIF_ARG_1);
+	    code = erts_dsig_send_unlink(&ctx, BIF_P->common.id, BIF_ARG_1);
 	    if (code == ERTS_DSIG_SEND_YIELD)
 		ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
             break;
@@ -1308,10 +1302,11 @@ static BIF_RETTYPE send_exit_signal_bif(Process *c_p, Eterm id, Eterm reason, in
              ERTS_BIF_PREP_RET(ret_val, am_true); /* Old incarnation of this node... */
          else {
              int code;
-             ErtsDSigData dsd;
+             ErtsDSigSendContext ctx;
+
+             code = erts_dsig_prepare(&ctx, dep, c_p, ERTS_PROC_LOCK_MAIN,
+                                      ERTS_DSP_NO_LOCK, 0, 0, 1);
 
-             code = erts_dsig_prepare(&dsd, dep, c_p, ERTS_PROC_LOCK_MAIN,
-                                      ERTS_DSP_NO_LOCK, 0, 1);
              switch (code) {
              case ERTS_DSIG_PREP_NOT_ALIVE:
              case ERTS_DSIG_PREP_NOT_CONNECTED:
@@ -1319,11 +1314,29 @@ static BIF_RETTYPE send_exit_signal_bif(Process *c_p, Eterm id, Eterm reason, in
                  break;
              case ERTS_DSIG_PREP_PENDING:
              case ERTS_DSIG_PREP_CONNECTED:
-                 code = erts_dsig_send_exit2(&dsd, c_p->common.id, id, reason);
-                 if (code == ERTS_DSIG_SEND_YIELD)
+                 code = erts_dsig_send_exit2(&ctx, c_p->common.id, id, reason);
+                 switch (code) {
+                 case ERTS_DSIG_SEND_YIELD:
                      ERTS_BIF_PREP_YIELD_RETURN(ret_val, c_p, am_true);
-                 else
+                     break;
+                 case ERTS_DSIG_SEND_CONTINUE:
+                     BUMP_ALL_REDS(c_p);
+                     erts_set_gc_state(c_p, 0);
+                     ERTS_BIF_PREP_TRAP1(ret_val, &dsend_continue_trap_export, c_p,
+                                         erts_dsend_export_trap_context(c_p, &ctx));
+                     break;
+                 case ERTS_DSIG_SEND_OK:
                      ERTS_BIF_PREP_RET(ret_val, am_true);
+                     break;
+                 case ERTS_DSIG_SEND_TOO_LRG:
+                     erts_set_gc_state(c_p, 1);
+                     ERTS_BIF_PREP_ERROR(ret_val, c_p, SYSTEM_LIMIT);
+                     break;
+                 default:
+                     ASSERT(! "Invalid dsig send exit2 result");
+                     ERTS_BIF_PREP_ERROR(ret_val, c_p, EXC_INTERNAL_ERROR);
+                     break;
+                 }
                  break;
              default:
                  ASSERT(! "Invalid dsig prepare result");
@@ -1803,36 +1816,40 @@ ebif_bang_2(BIF_ALIST_2)
 #define SEND_INTERNAL_ERROR	(-6)
 #define SEND_AWAIT_RESULT	(-7)
 #define SEND_YIELD_CONTINUE     (-8)
+#define SEND_SYSTEM_LIMIT		(-9)
 
 
 static Sint remote_send(Process *p, DistEntry *dep,
-			Eterm to, Eterm full_to, Eterm msg,
-			ErtsSendContext* ctx)
+			Eterm to, Eterm node, Eterm full_to, Eterm msg,
+                        Eterm return_term, Eterm *ctxpp,
+                        int connect, int suspend)
 {
     Sint res;
     int code;
+    ErtsDSigSendContext ctx;
     ASSERT(is_atom(to) || is_external_pid(to));
 
-    ctx->dep = dep;
-    code = erts_dsig_prepare(&ctx->dsd, dep, p, ERTS_PROC_LOCK_MAIN,
+    code = erts_dsig_prepare(&ctx, dep, p, ERTS_PROC_LOCK_MAIN,
 			     ERTS_DSP_NO_LOCK,
-			     !ctx->suspend, ctx->connect);
+			     !suspend, 0, connect);
+    ctx.return_term = return_term;
+    ctx.node = node;
     switch (code) {
     case ERTS_DSIG_PREP_NOT_ALIVE:
     case ERTS_DSIG_PREP_NOT_CONNECTED:
 	res = SEND_NOCONNECT;
 	break;
     case ERTS_DSIG_PREP_WOULD_SUSPEND:
-	ASSERT(!ctx->suspend);
+	ASSERT(!suspend);
 	res = SEND_YIELD;
 	break;
     case ERTS_DSIG_PREP_PENDING:
     case ERTS_DSIG_PREP_CONNECTED: {
 
 	if (is_atom(to))
-	    code = erts_dsig_send_reg_msg(to, msg, ctx);
+	    code = erts_dsig_send_reg_msg(&ctx, to, msg);
 	else
-	    code = erts_dsig_send_msg(to, msg, ctx);
+	    code = erts_dsig_send_msg(&ctx, to, msg);
 	/*
 	 * Note that reductions have been bumped on calling
 	 * process by erts_dsig_send_reg_msg() or
@@ -1840,8 +1857,20 @@ static Sint remote_send(Process *p, DistEntry *dep,
 	 */
 	if (code == ERTS_DSIG_SEND_YIELD)
 	    res = SEND_YIELD_RETURN;
-	else if (code == ERTS_DSIG_SEND_CONTINUE)
+	else if (code == ERTS_DSIG_SEND_CONTINUE) {
+            erts_set_gc_state(p, 0);
+
+            /* Keep a reference to the dist entry if the
+               name is an not a pid. */
+            if (is_atom(to)) {
+                erts_ref_dist_entry(ctx.dep);
+                ctx.deref_dep = 1;
+            }
+
+            *ctxpp = erts_dsend_export_trap_context(p, &ctx);
 	    res = SEND_YIELD_CONTINUE;
+	} else if (code == ERTS_DSIG_SEND_TOO_LRG)
+	    res = SEND_SYSTEM_LIMIT;
 	else
 	    res = 0;
 	break;
@@ -1862,7 +1891,8 @@ static Sint remote_send(Process *p, DistEntry *dep,
 }
 
 static Sint
-do_send(Process *p, Eterm to, Eterm msg, Eterm *refp, ErtsSendContext *ctx)
+do_send(Process *p, Eterm to, Eterm msg, Eterm return_term, Eterm *refp,
+        Eterm *dist_ctx, int connect, int suspend)
 {
     Eterm portid;
     Port *pt;
@@ -1894,7 +1924,8 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm *refp, ErtsSendContext *ctx)
 	    erts_send_error_to_logger(p->group_leader, dsbufp);
 	    return 0;
 	}
-	return remote_send(p, dep, to, to, msg, ctx);
+	return remote_send(p, dep, to, dep->sysname, to, msg, return_term,
+                           dist_ctx, connect, suspend);
     } else if (is_atom(to)) {
 	Eterm id = erts_whereis_name_to_id(p, to);
 
@@ -1949,7 +1980,7 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm *refp, ErtsSendContext *ctx)
 	ret_val = 0;
 
 	if (pt) {
-	    int ps_flags = ctx->suspend ? 0 : ERTS_PORT_SIG_FLG_NOSUSPEND;
+	    int ps_flags = suspend ? 0 : ERTS_PORT_SIG_FLG_NOSUSPEND;
 	    *refp = NIL;
 
             if (IS_TRACED_FL(p, F_TRACE_SEND)) 	/* trace once only !! */
@@ -1964,12 +1995,12 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm *refp, ErtsSendContext *ctx)
 	    switch (erts_port_command(p, ps_flags, pt, msg, refp)) {
 	    case ERTS_PORT_OP_BUSY:
 		/* Nothing has been sent */
-		if (ctx->suspend)
+		if (suspend)
 		    erts_suspend(p, ERTS_PROC_LOCK_MAIN, pt);
 		return SEND_YIELD;
 	    case ERTS_PORT_OP_BUSY_SCHEDULED:
 		/* Message was sent */
-		if (ctx->suspend) {
+		if (suspend) {
 		    erts_suspend(p, ERTS_PROC_LOCK_MAIN, pt);
 		    ret_val = SEND_YIELD_RETURN;
 		    break;
@@ -2040,13 +2071,10 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm *refp, ErtsSendContext *ctx)
             ASSERT(dep != erts_this_dist_entry);
             deref_dep = 1;
         }
-	ctx->dsd.node = tp[2];
 
-	ret = remote_send(p, dep, tp[1], to, msg, ctx);
-	if (ret == SEND_YIELD_CONTINUE) {
-            erts_ref_dist_entry(ctx->dep);
-            ctx->deref_dep = 1;
-	}
+	ret = remote_send(p, dep, tp[1], tp[2], to, msg, return_term,
+                          dist_ctx, connect, suspend);
+
         if (deref_dep)
             erts_deref_dist_entry(dep);
 	return ret;
@@ -2085,25 +2113,16 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
 
     Eterm l = opts;
     Sint result;
-
-    DeclareTypedTmpHeap(ErtsSendContext, ctx, BIF_P);
+    int connect = 1, suspend = 1;
+    Eterm ctx;
 
     ERTS_MSACC_PUSH_STATE_M_X();
 
-    UseTmpHeap(sizeof(ErtsSendContext)/sizeof(Eterm), BIF_P);
-
-    ctx->suspend = !0;
-    ctx->connect = !0;
-    ctx->deref_dep = 0;
-    ctx->return_term = am_ok;
-    ctx->dss.reds = (Sint) (ERTS_BIF_REDS_LEFT(p) * TERM_TO_BINARY_LOOP_FACTOR);
-    ctx->dss.phase = ERTS_DSIG_SEND_PHASE_INIT;
-
     while (is_list(l)) {
 	if (CAR(list_val(l)) == am_noconnect) {
-	    ctx->connect = 0;
+	    connect = 0;
 	} else if (CAR(list_val(l)) == am_nosuspend) {
-	    ctx->suspend = 0;
+	    suspend = 0;
 	} else {
 	    ERTS_BIF_PREP_ERROR(retval, p, BADARG);
 	    goto done;
@@ -2120,7 +2139,7 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
 #endif
 
     ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_SEND);
-    result = do_send(p, to, msg, &ref, ctx);
+    result = do_send(p, to, msg, am_ok, &ref, &ctx, connect, suspend);
     ERTS_MSACC_POP_STATE_M_X();
 
     if (result >= 0) {
@@ -2133,22 +2152,21 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
 
     switch (result) {
     case SEND_NOCONNECT:
-	if (ctx->connect) {
+	if (connect) {
 	    ERTS_BIF_PREP_RET(retval, am_ok);
 	} else {
 	    ERTS_BIF_PREP_RET(retval, am_noconnect);
 	}
 	break;
     case SEND_YIELD:
-	if (ctx->suspend) {
-	    ERTS_BIF_PREP_YIELD3(retval,
-				 bif_export[BIF_send_3], p, to, msg, opts);
+	if (suspend) {
+	    ERTS_BIF_PREP_YIELD3(retval, bif_export[BIF_send_3], p, to, msg, opts);
 	} else {
 	    ERTS_BIF_PREP_RET(retval, am_nosuspend);
 	}
 	break;
     case SEND_YIELD_RETURN:
-	if (!ctx->suspend) {
+	if (!suspend) {
 	    ERTS_BIF_PREP_RET(retval, am_nosuspend);
 	    break;
 	}
@@ -2162,6 +2180,9 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
     case SEND_BADARG:
 	ERTS_BIF_PREP_ERROR(retval, p, BADARG);
 	break;
+    case SEND_SYSTEM_LIMIT:
+	ERTS_BIF_PREP_ERROR(retval, p, SYSTEM_LIMIT);
+	break;
     case SEND_USER_ERROR:
 	ERTS_BIF_PREP_ERROR(retval, p, EXC_ERROR);
 	break;
@@ -2170,9 +2191,7 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
 	break;
     case SEND_YIELD_CONTINUE:
 	BUMP_ALL_REDS(p);
-	erts_set_gc_state(p, 0);
-	ERTS_BIF_PREP_TRAP1(retval, &dsend_continue_trap_export, p,
-			    erts_dsend_export_trap_context(p, ctx));
+	ERTS_BIF_PREP_TRAP1(retval, &dsend_continue_trap_export, p, ctx);
 	break;
     default:
 	erts_exit(ERTS_ABORT_EXIT, "send_3 invalid result %d\n", (int)result);
@@ -2180,7 +2199,6 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
     }
 
 done:
-    UnUseTmpHeap(sizeof(ErtsSendContext)/sizeof(Eterm), BIF_P);
     return retval;
 }
 
@@ -2194,14 +2212,14 @@ BIF_RETTYPE send_2(BIF_ALIST_2)
 static BIF_RETTYPE dsend_continue_trap_1(BIF_ALIST_1)
 {
     Binary* bin = erts_magic_ref2bin(BIF_ARG_1);
-    ErtsSendContext* ctx = (ErtsSendContext*) ERTS_MAGIC_BIN_DATA(bin);
+    ErtsDSigSendContext *ctx = (ErtsDSigSendContext*) ERTS_MAGIC_BIN_DATA(bin);
     Sint initial_reds = (Sint) (ERTS_BIF_REDS_LEFT(BIF_P) * TERM_TO_BINARY_LOOP_FACTOR);
     int result;
 
     ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(bin) == erts_dsend_context_dtor);
 
-    ctx->dss.reds = initial_reds;
-    result = erts_dsig_send(&ctx->dsd, &ctx->dss);
+    ctx->reds = initial_reds;
+    result = erts_dsig_send(ctx);
 
     switch (result) {
     case ERTS_DSIG_SEND_OK:
@@ -2210,7 +2228,7 @@ static BIF_RETTYPE dsend_continue_trap_1(BIF_ALIST_1)
 	break;
     case ERTS_DSIG_SEND_YIELD: /*SEND_YIELD_RETURN*/
 	erts_set_gc_state(BIF_P, 1);
-	if (!ctx->suspend)
+	if (ctx->no_suspend)
 	    BIF_RET(am_nosuspend);
 	ERTS_BIF_YIELD_RETURN(BIF_P, ctx->return_term);
 
@@ -2218,6 +2236,10 @@ static BIF_RETTYPE dsend_continue_trap_1(BIF_ALIST_1)
 	BUMP_ALL_REDS(BIF_P);
 	BIF_TRAP1(&dsend_continue_trap_export, BIF_P, BIF_ARG_1);
     }
+    case ERTS_DSIG_SEND_TOO_LRG: { /*SEND_SYSTEM_LIMIT*/
+	erts_set_gc_state(BIF_P, 1);
+	BIF_ERROR(BIF_P, SYSTEM_LIMIT);
+    }
     default:
 	erts_exit(ERTS_ABORT_EXIT, "dsend_continue_trap invalid result %d\n", (int)result);
 	break;
@@ -2231,20 +2253,14 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg)
     Eterm retval;
     Eterm ref;
     Sint result;
-    DeclareTypedTmpHeap(ErtsSendContext, ctx, p);
+    Eterm ctx;
     ERTS_MSACC_PUSH_AND_SET_STATE_M_X(ERTS_MSACC_STATE_SEND);
-    UseTmpHeap(sizeof(ErtsSendContext)/sizeof(Eterm), p);
+
 #ifdef DEBUG
     ref = NIL;
 #endif
-    ctx->suspend = !0;
-    ctx->connect = !0;
-    ctx->deref_dep = 0;
-    ctx->return_term = msg;
-    ctx->dss.reds = (Sint) (ERTS_BIF_REDS_LEFT(p) * TERM_TO_BINARY_LOOP_FACTOR);
-    ctx->dss.phase = ERTS_DSIG_SEND_PHASE_INIT;
 
-    result = do_send(p, to, msg, &ref, ctx);
+    result = do_send(p, to, msg, msg, &ref, &ctx, 1, 1);
 
     ERTS_MSACC_POP_STATE_M_X();
 
@@ -2275,6 +2291,9 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg)
     case SEND_BADARG:
 	ERTS_BIF_PREP_ERROR(retval, p, BADARG);
 	break;
+    case SEND_SYSTEM_LIMIT:
+	ERTS_BIF_PREP_ERROR(retval, p, SYSTEM_LIMIT);
+	break;
     case SEND_USER_ERROR:
 	ERTS_BIF_PREP_ERROR(retval, p, EXC_ERROR);
 	break;
@@ -2283,9 +2302,7 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg)
 	break;
     case SEND_YIELD_CONTINUE:
 	BUMP_ALL_REDS(p);
-	erts_set_gc_state(p, 0);
-	ERTS_BIF_PREP_TRAP1(retval, &dsend_continue_trap_export, p,
-			    erts_dsend_export_trap_context(p, ctx));
+	ERTS_BIF_PREP_TRAP1(retval, &dsend_continue_trap_export, p, ctx);
 	break;
     default:
 	erts_exit(ERTS_ABORT_EXIT, "invalid send result %d\n", (int)result);
@@ -2293,7 +2310,6 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg)
     }
 
 done:
-    UnUseTmpHeap(sizeof(ErtsSendContext)/sizeof(Eterm), p);
     return retval;
 }
 
@@ -2359,7 +2375,7 @@ accumulate(Eterm acc, Uint size)
 	 * bignum buffer with one extra word to be used if
 	 * the bignum grows in the future.
 	 */
-	Eterm* hp = (Eterm *) erts_alloc(ERTS_ALC_T_TEMP_TERM,
+	Eterm* hp = (Eterm *) erts_alloc(ERTS_ALC_T_SHORT_LIVED_TERM,
 					 (BIG_UINT_HEAP_SIZE+1) *
 					 sizeof(Eterm));
 	return uint_to_big(size, hp);
@@ -2379,7 +2395,7 @@ accumulate(Eterm acc, Uint size)
 	     * The extra word has been consumed. Grow the
 	     * allocation by one word.
 	     */
-	    big = (Eterm *) erts_realloc(ERTS_ALC_T_TEMP_TERM,
+	    big = (Eterm *) erts_realloc(ERTS_ALC_T_SHORT_LIVED_TERM,
 					 big_val(acc),
 					 (need_heap+1) * sizeof(Eterm));
 	    acc = make_big(big);
@@ -2408,29 +2424,86 @@ consolidate(Process* p, Eterm acc, Uint size)
 	while (sz--) {
 	    *hp++ = *big++;
 	}
-	erts_free(ERTS_ALC_T_TEMP_TERM, (void *) big_val(acc));
+	erts_free(ERTS_ALC_T_SHORT_LIVED_TERM, (void *) big_val(acc));
 	return res;
     }
 }
 
+typedef struct {
+    Eterm obj;
+    Uint size;
+    Eterm acc;
+    Eterm input_list;
+    ErtsEStack stack;
+    int is_trap_at_L_iter_list;
+} ErtsIOListSizeContext;
+
+static int iolist_size_ctx_bin_dtor(Binary *context_bin) {
+    ErtsIOListSizeContext* context = ERTS_MAGIC_BIN_DATA(context_bin);
+    DESTROY_SAVED_ESTACK(&context->stack);
+    if (context->acc != THE_NON_VALUE) {
+        erts_free(ERTS_ALC_T_SHORT_LIVED_TERM, (void *) big_val(context->acc));
+    }
+    return 1;
+}
+
 BIF_RETTYPE iolist_size_1(BIF_ALIST_1)
 {
-    Eterm obj, hd;
+    static const Uint ITERATIONS_PER_RED = 64;
+    Eterm input_list, obj, hd;
     Eterm* objp;
     Uint size = 0;
     Uint cur_size;
     Uint new_size;
     Eterm acc = THE_NON_VALUE;
     DECLARE_ESTACK(s);
-
-    obj = BIF_ARG_1;
+    Uint max_iterations;
+    Uint iterations_until_trap = max_iterations =
+        ITERATIONS_PER_RED * ERTS_BIF_REDS_LEFT(BIF_P);
+    ErtsIOListSizeContext* context = NULL;
+    Eterm state_mref;
+    int is_trap_at_L_iter_list;
+    ERTS_UNDEF(state_mref, THE_NON_VALUE);
+    ESTACK_CHANGE_ALLOCATOR(s, ERTS_ALC_T_SAVED_ESTACK);
+#ifdef DEBUG
+    iterations_until_trap = iterations_until_trap / 10;
+#endif
+    input_list = obj = BIF_ARG_1;
+    if (is_internal_magic_ref(obj)) {
+        /* Restore state after a trap */
+        Binary* state_bin;
+        state_mref = obj;
+        state_bin = erts_magic_ref2bin(state_mref);
+        if (ERTS_MAGIC_BIN_DESTRUCTOR(state_bin) != iolist_size_ctx_bin_dtor) {
+            BIF_ERROR(BIF_P, BADARG);
+        }
+        context = ERTS_MAGIC_BIN_DATA(state_bin);
+        obj = context->obj;
+        size = context->size;
+        acc = context->acc;
+        input_list = context->input_list;
+        ESTACK_RESTORE(s, &context->stack);
+        ASSERT(BIF_P->flags & F_DISABLE_GC);
+        erts_set_gc_state(BIF_P, 1);
+        if (context->is_trap_at_L_iter_list) {
+            goto L_iter_list;
+        }
+    }
     goto L_again;
 
     while (!ESTACK_ISEMPTY(s)) {
 	obj = ESTACK_POP(s);
+        if (iterations_until_trap == 0) {
+            is_trap_at_L_iter_list = 0;
+            goto L_save_state_and_trap;
+        }
     L_again:
 	if (is_list(obj)) {
 	L_iter_list:
+            if (iterations_until_trap == 0) {
+                is_trap_at_L_iter_list = 1;
+                goto L_save_state_and_trap;
+            }
 	    objp = list_val(obj);
 	    hd = CAR(objp);
 	    obj = CDR(objp);
@@ -2452,12 +2525,14 @@ BIF_RETTYPE iolist_size_1(BIF_ALIST_1)
 	    } else if (is_list(hd)) {
 		ESTACK_PUSH(s, obj);
 		obj = hd;
+                iterations_until_trap--;
 		goto L_iter_list;
 	    } else if (is_not_nil(hd)) {
 		goto L_type_error;
 	    }
 	    /* Tail */
 	    if (is_list(obj)) {
+                iterations_until_trap--;
 		goto L_iter_list;
 	    } else if (is_binary(obj) && binary_bitsize(obj) == 0) {
 		cur_size = binary_size(obj);
@@ -2481,14 +2556,55 @@ BIF_RETTYPE iolist_size_1(BIF_ALIST_1)
 	} else if (is_not_nil(obj)) {
 	    goto L_type_error;
 	}
+        iterations_until_trap--;
     }
 
     DESTROY_ESTACK(s);
+    BUMP_REDS(BIF_P, (max_iterations - iterations_until_trap) / ITERATIONS_PER_RED);
+    ASSERT(!(BIF_P->flags & F_DISABLE_GC));
+    if (context != NULL) {
+        /* context->acc needs to be reset so that
+           iolist_size_ctx_bin_dtor does not deallocate twice */
+        context->acc = THE_NON_VALUE;
+    }
     BIF_RET(consolidate(BIF_P, acc, size));
 
  L_type_error:
     DESTROY_ESTACK(s);
-    BIF_ERROR(BIF_P, BADARG);
+    if (acc != THE_NON_VALUE) {
+	erts_free(ERTS_ALC_T_SHORT_LIVED_TERM, (void *) big_val(acc));
+        if (context != NULL) {
+            context->acc = THE_NON_VALUE;
+        }
+    }
+    BUMP_REDS(BIF_P, (max_iterations - iterations_until_trap) / ITERATIONS_PER_RED);
+    ASSERT(!(BIF_P->flags & F_DISABLE_GC));
+    if (context == NULL) {
+        BIF_ERROR(BIF_P, BADARG);
+    } else {
+        ERTS_BIF_ERROR_TRAPPED1(BIF_P,
+                                BADARG,
+                                bif_export[BIF_iolist_size_1],
+                                input_list);
+    }
+
+ L_save_state_and_trap:
+    if (context == NULL) {
+        Binary *state_bin = erts_create_magic_binary(sizeof(ErtsIOListSizeContext),
+                                                     iolist_size_ctx_bin_dtor);
+        Eterm* hp = HAlloc(BIF_P, ERTS_MAGIC_REF_THING_SIZE);
+        state_mref = erts_mk_magic_ref(&hp, &MSO(BIF_P), state_bin);
+        context = ERTS_MAGIC_BIN_DATA(state_bin);
+    }
+    context->obj = obj;
+    context->size = size;
+    context->acc = acc;
+    context->is_trap_at_L_iter_list = is_trap_at_L_iter_list;
+    context->input_list = input_list;
+    ESTACK_SAVE(s, &context->stack);
+    erts_set_gc_state(BIF_P, 0);
+    BUMP_ALL_REDS(BIF_P);
+    BIF_TRAP1(bif_export[BIF_iolist_size_1], BIF_P, state_mref);
 }
 
 /**********************************************************************/
@@ -2732,9 +2848,7 @@ BIF_RETTYPE atom_to_list_1(BIF_ALIST_1)
     Uint num_chars, num_built, num_eaten;
     byte* err_pos;
     Eterm res;
-#ifdef DEBUG
     int ares;
-#endif
 
     if (is_not_atom(BIF_ARG_1))
 	BIF_ERROR(BIF_P, BADARG);
@@ -2744,11 +2858,9 @@ BIF_RETTYPE atom_to_list_1(BIF_ALIST_1)
     if (ap->len == 0)
 	BIF_RET(NIL);	/* the empty atom */
 
-#ifdef DEBUG
     ares =
-#endif
 	erts_analyze_utf8(ap->name, ap->len, &err_pos, &num_chars, NULL);
-    ASSERT(ares == ERTS_UTF8_OK);
+    ASSERT(ares == ERTS_UTF8_OK); (void)ares;
     
     res = erts_utf8_to_list(BIF_P, num_chars, ap->name, ap->len, ap->len,
 			    &num_built, &num_eaten, NIL);
@@ -2810,38 +2922,110 @@ BIF_RETTYPE list_to_existing_atom_1(BIF_ALIST_1)
 
 /* convert an integer to a list of ascii integers */
 
-BIF_RETTYPE integer_to_list_1(BIF_ALIST_1)
+static Eterm integer_to_list(Process *c_p, Eterm num, int base)
 {
-    Eterm* hp;
+    Eterm *hp;
+    Eterm res;
     Uint need;
 
+    if (is_small(num)) {
+        char s[128];
+        char *c = s;
+        Uint digits;
+
+        digits = Sint_to_buf(signed_val(num), base, &c, sizeof(s));
+        need = 2 * digits;
+
+        hp = HAlloc(c_p, need);
+        res = buf_to_intlist(&hp, c, digits, NIL);
+    } else {
+        const int DIGITS_PER_RED = 16;
+        Eterm *hp_end;
+        Uint digits;
+
+        digits = big_integer_estimate(num, base);
+
+        if ((digits / DIGITS_PER_RED) > ERTS_BIF_REDS_LEFT(c_p)) {
+            ErtsSchedulerData *esdp = erts_get_scheduler_data();
+
+            /* This could take a very long time, tell the caller to reschedule
+             * us to a dirty CPU scheduler if we aren't already on one. */
+            if (esdp->type == ERTS_SCHED_NORMAL) {
+                return THE_NON_VALUE;
+            }
+        } else {
+            BUMP_REDS(c_p, digits / DIGITS_PER_RED);
+        }
+
+        need = 2 * digits;
+
+        hp = HAlloc(c_p, need);
+        hp_end = hp + need;
+
+        res = erts_big_to_list(num, base, &hp);
+        HRelease(c_p, hp_end, hp);
+    }
+
+    return res;
+}
+
+BIF_RETTYPE integer_to_list_1(BIF_ALIST_1)
+{
+    Eterm res;
+
     if (is_not_integer(BIF_ARG_1)) {
-	BIF_ERROR(BIF_P, BADARG);
+        BIF_ERROR(BIF_P, BADARG);
     }
 
-    if (is_small(BIF_ARG_1)) {
-	char *c;
-	int n;
-	struct Sint_buf ibuf;
+    res = integer_to_list(BIF_P, BIF_ARG_1, 10);
 
-	c = Sint_to_buf(signed_val(BIF_ARG_1), &ibuf);
-	n = sys_strlen(c);
-	need = 2*n;
-	hp = HAlloc(BIF_P, need);
-	BIF_RET(buf_to_intlist(&hp, c, n, NIL));
+    if (is_non_value(res)) {
+        Eterm args[1];
+        args[0] = BIF_ARG_1;
+        return erts_schedule_bif(BIF_P,
+                                 args,
+                                 BIF_I,
+                                 integer_to_list_1,
+                                 ERTS_SCHED_DIRTY_CPU,
+                                 am_erlang,
+                                 am_integer_to_list,
+                                 1);
     }
-    else {
-	int n = big_decimal_estimate(BIF_ARG_1);
-	Eterm res;
-        Eterm* hp_end;
 
-	need = 2*n;
-	hp = HAlloc(BIF_P, need);
-        hp_end = hp + need;
-	res = erts_big_to_list(BIF_ARG_1, &hp);
-        HRelease(BIF_P,hp_end,hp);
-	BIF_RET(res);
+    return res;
+}
+
+BIF_RETTYPE integer_to_list_2(BIF_ALIST_2)
+{
+    Eterm res;
+    SWord base;
+
+    if (is_not_integer(BIF_ARG_1) || is_not_small(BIF_ARG_2)) {
+        BIF_ERROR(BIF_P, BADARG);
     }
+
+    base = signed_val(BIF_ARG_2);
+    if (base < 2 || base > 36) {
+        BIF_ERROR(BIF_P, BADARG);
+    }
+
+    res = integer_to_list(BIF_P, BIF_ARG_1, base);
+
+    if (is_non_value(res)) {
+        Eterm args[2];
+        args[0] = BIF_ARG_1;
+        args[1] = BIF_ARG_2;
+        return erts_schedule_bif(BIF_P,
+                                 args,
+                                 BIF_I,
+                                 integer_to_list_2,
+                                 ERTS_SCHED_DIRTY_CPU,
+                                 am_erlang,
+                                 am_integer_to_list,
+                                 2);
+    }
+
+    return res;
 }
 
 /**********************************************************************/
@@ -3979,10 +4163,12 @@ BIF_RETTYPE list_to_pid_1(BIF_ALIST_1)
       if (is_nil(dep->cid))
 	  goto bad;
       
-      enp = erts_find_or_insert_node(dep->sysname, dep->creation);
+      etp = (ExternalThing *) HAlloc(BIF_P, EXTERNAL_THING_HEAD_SIZE + 1);
+      
+      enp = erts_find_or_insert_node(dep->sysname, dep->creation,
+                                     make_boxed(&etp->header));
       ASSERT(enp != erts_this_node);
 
-      etp = (ExternalThing *) HAlloc(BIF_P, EXTERNAL_THING_HEAD_SIZE + 1);
       etp->header = make_external_pid_header(1);
       etp->next = MSO(BIF_P).first;
       etp->node = enp;
@@ -4046,10 +4232,11 @@ BIF_RETTYPE list_to_port_1(BIF_ALIST_1)
       if (is_nil(dep->cid))
 	  goto bad;
 
-      enp = erts_find_or_insert_node(dep->sysname, dep->creation);
+      etp = (ExternalThing *) HAlloc(BIF_P, EXTERNAL_THING_HEAD_SIZE + 1);
+      enp = erts_find_or_insert_node(dep->sysname, dep->creation,
+                                     make_boxed(&etp->header));
       ASSERT(enp != erts_this_node);
 
-      etp = (ExternalThing *) HAlloc(BIF_P, EXTERNAL_THING_HEAD_SIZE + 1);
       etp->header = make_external_port_header(1);
       etp->next = MSO(BIF_P).first;
       etp->node = enp;
@@ -4127,7 +4314,7 @@ BIF_RETTYPE list_to_ref_1(BIF_ALIST_1)
     if(dep == erts_this_dist_entry) {
         ErtsMagicBinary *mb;
         Uint32 sid;
-        if (refn[0] > MAX_REFERENCE) goto bad;
+        if (refn[0] >= MAX_REFERENCE) goto bad;
         if (n != ERTS_REF_NUMBERS) goto bad;
         sid = erts_get_ref_numbers_thr_id(refn);
         if (sid > erts_no_schedulers) goto bad;
@@ -4152,9 +4339,6 @@ BIF_RETTYPE list_to_ref_1(BIF_ALIST_1)
       if (is_nil(dep->cid))
 	  goto bad;
       
-      enp = erts_find_or_insert_node(dep->sysname, dep->creation);
-      ASSERT(enp != erts_this_node);
-
       hsz = EXTERNAL_THING_HEAD_SIZE;
 #if defined(ARCH_64)
       hsz += n/2 + 1;
@@ -4163,6 +4347,11 @@ BIF_RETTYPE list_to_ref_1(BIF_ALIST_1)
 #endif
 
       etp = (ExternalThing *) HAlloc(BIF_P, hsz);
+
+      enp = erts_find_or_insert_node(dep->sysname, dep->creation,
+                                     make_boxed(&etp->header));
+      ASSERT(enp != erts_this_node);
+
       etp->header = make_external_ref_header(n/2);
       etp->next = BIF_P->off_heap.first;
       etp->node = enp;
@@ -4282,21 +4471,21 @@ BIF_RETTYPE erts_internal_group_leader_2(BIF_ALIST_2)
     if (is_external_pid(BIF_ARG_2)) {
 	DistEntry *dep;
 	int code;
-	ErtsDSigData dsd;
+	ErtsDSigSendContext ctx;
 	dep = external_pid_dist_entry(BIF_ARG_2);
 	ERTS_ASSERT(dep);
 	if(dep == erts_this_dist_entry)
 	    BIF_ERROR(BIF_P, BADARG);
 
-	code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_PROC_LOCK_MAIN,
-				 ERTS_DSP_NO_LOCK, 0, 1);
+	code = erts_dsig_prepare(&ctx, dep, BIF_P, ERTS_PROC_LOCK_MAIN,
+				 ERTS_DSP_NO_LOCK, 0, 1, 1);
 	switch (code) {
 	case ERTS_DSIG_PREP_NOT_ALIVE:
 	case ERTS_DSIG_PREP_NOT_CONNECTED:
 	    BIF_RET(am_true);
 	case ERTS_DSIG_PREP_PENDING:
 	case ERTS_DSIG_PREP_CONNECTED:
-	    code = erts_dsig_send_group_leader(&dsd, BIF_ARG_1, BIF_ARG_2);
+	    code = erts_dsig_send_group_leader(&ctx, BIF_ARG_1, BIF_ARG_2);
 	    if (code == ERTS_DSIG_SEND_YIELD)
 		ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
 	    BIF_RET(am_true);
@@ -4442,13 +4631,6 @@ BIF_RETTYPE system_flag_2(BIF_ALIST_2)
         erts_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
 
         BIF_RET(old_value);
-    } else if (BIF_ARG_1 == am_display_items) {
-	int oval = display_items;
-	if (!is_small(BIF_ARG_2) || (n = signed_val(BIF_ARG_2)) < 0) {
-	    goto error;
-	}
-	display_items = n < 32 ? 32 : n;
-	BIF_RET(make_small(oval));
     } else if (BIF_ARG_1 == am_debug_flags) {
 	BIF_RET(am_true);
     } else if (BIF_ARG_1 == am_backtrace_depth) {
@@ -4490,11 +4672,12 @@ BIF_RETTYPE system_flag_2(BIF_ALIST_2)
         ERTS_TRACER_CLEAR(&old_seq_tracer);
 
         BIF_RET(ret);
-    } else if (BIF_ARG_1 == make_small(1)) {
+    } else if (BIF_ARG_1 == am_reset_seq_trace) {
 	int i, max;
-	erts_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
-	erts_thr_progress_block();
 
+        erts_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
+        erts_thr_progress_block();
+        
 	max = erts_ptab_max(&erts_proc);
 	for (i = 0; i < max; i++) {
 	    Process *p = erts_pix2proc(i);
@@ -4506,13 +4689,14 @@ BIF_RETTYPE system_flag_2(BIF_ALIST_2)
 #endif
 		p->seq_trace_clock = 0;
 		p->seq_trace_lastcnt = 0;
-
+                erts_proc_lock(p, ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_MSGQ);
                 erts_proc_sig_clear_seq_trace_tokens(p);
+                erts_proc_unlock(p, ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_MSGQ);
 	    }
 	}
 
-	erts_thr_progress_unblock();
-	erts_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
+        erts_thr_progress_unblock();
+        erts_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
 
 	BIF_RET(am_true);
     } else if (BIF_ARG_1 == am_scheduler_wall_time) {
@@ -4627,6 +4811,9 @@ BIF_RETTYPE system_flag_2(BIF_ALIST_2)
 	return erts_bind_schedulers(BIF_P, BIF_ARG_2);
     } else if (ERTS_IS_ATOM_STR("erts_alloc", BIF_ARG_1)) {
         return erts_alloc_set_dyn_param(BIF_P, BIF_ARG_2);
+    } else if (ERTS_IS_ATOM_STR("system_logger", BIF_ARG_1)) {
+        Eterm res = erts_set_system_logger(BIF_ARG_2);
+        if (is_value(res)) BIF_RET(res);
     }
     error:
     BIF_ERROR(BIF_P, BADARG);
@@ -4979,6 +5166,12 @@ erts_schedule_bif(Process *proc,
 	    pc = i;
 	    mfa = &exp->info.mfa;
 	}
+	else if (BeamIsOpCode(*i, op_call_bif_only_e)) {
+	    /* Pointer to bif export in i+1 */
+	    exp = (Export *) i[1];
+	    pc = i;
+	    mfa = &exp->info.mfa;
+	}
 	else if (BeamIsOpCode(*i, op_apply_bif)) {
 	    /* Pointer to bif in i+1, and mfa in i-3 */	    
 	    pc = c_p->cp;
@@ -5129,61 +5322,6 @@ erts_call_dirty_bif(ErtsSchedulerData *esdp, Process *c_p, BeamInstr *I, Eterm *
     return exiting;
 }
 
-
-
-#ifdef HARDDEBUG
-/*
-You'll need this line in bif.tab to be able to use this debug bif
-
-bif erlang:send_to_logger/2
-
-*/
-BIF_RETTYPE send_to_logger_2(BIF_ALIST_2)
-{
-    byte *buf;
-    ErlDrvSizeT len;
-    if (!is_atom(BIF_ARG_1) || !(is_list(BIF_ARG_2) ||
-				 is_nil(BIF_ARG_1))) {
-	BIF_ERROR(BIF_P,BADARG);
-    }
-    if (erts_iolist_size(BIF_ARG_2, &len) != 0)
-	BIF_ERROR(BIF_P,BADARG);
-    else if (len == 0)
-	buf = "";
-    else {
-#ifdef DEBUG
-	ErlDrvSizeT len2;
-#endif
-	buf = (byte *) erts_alloc(ERTS_ALC_T_TMP, len+1);
-#ifdef DEBUG
-	len2 =
-#else
-	(void)
-#endif
-	    erts_iolist_to_buf(BIF_ARG_2, buf, len);
-	ASSERT(len2 == len);
-	buf[len] = '\0';
-	switch (BIF_ARG_1) {
-	case am_info:
-	    erts_send_info_to_logger(BIF_P->group_leader, buf, len);
-	    break;
-	case am_warning:
-	    erts_send_warning_to_logger(BIF_P->group_leader, buf, len);
-	    break;
-	case am_error:
-	    erts_send_error_to_logger(BIF_P->group_leader, buf, len);
-	    break;
-	default:
-	{
-	    BIF_ERROR(BIF_P,BADARG);
-	}
-	}
-	erts_free(ERTS_ALC_T_TMP, (void *) buf);
-    }
-    BIF_RET(am_true);
-}
-#endif /* HARDDEBUG */
-
 BIF_RETTYPE get_module_info_1(BIF_ALIST_1)
 {
     Eterm ret = erts_module_info_0(BIF_P, BIF_ARG_1);
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index d4ba90a61a..602db106b1 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -41,7 +41,7 @@
 #
 
 
-gcbif erlang:abs/1
+ubif erlang:abs/1
 bif erlang:adler32/1
 bif erlang:adler32/2
 bif erlang:adler32_combine/3
@@ -66,7 +66,7 @@ bif erlang:exit/2
 bif erlang:exit_signal/2
 bif erlang:external_size/1
 bif erlang:external_size/2
-gcbif erlang:float/1
+ubif erlang:float/1
 bif erlang:float_to_list/1
 bif erlang:float_to_list/2
 bif erlang:fun_info/2
@@ -84,7 +84,7 @@ bif erlang:phash2/2
 ubif erlang:hd/1
 bif erlang:integer_to_list/1
 bif erlang:is_alive/0
-gcbif erlang:length/1
+ubif erlang:length/1
 bif erlang:link/1
 bif erlang:list_to_atom/1
 bif erlang:list_to_binary/1
@@ -133,10 +133,10 @@ bif erlang:processes/0
 bif erlang:put/2
 bif erlang:register/2
 bif erlang:registered/0
-gcbif erlang:round/1
+ubif erlang:round/1
 ubif erlang:self/0
 bif erlang:setelement/3
-gcbif erlang:size/1
+ubif erlang:size/1
 bif erlang:spawn/3
 bif erlang:spawn_link/3
 bif erlang:split_binary/2
@@ -146,7 +146,7 @@ bif erlang:term_to_binary/2
 bif erlang:throw/1
 bif erlang:time/0
 ubif erlang:tl/1
-gcbif erlang:trunc/1
+ubif erlang:trunc/1
 bif erlang:tuple_to_list/1
 bif erlang:universaltime/0
 bif erlang:universaltime_to_localtime/1
@@ -160,6 +160,8 @@ bif erlang:dist_ctrl_input_handler/2
 bif erlang:dist_ctrl_put_data/2
 bif erlang:dist_ctrl_get_data/1
 bif erlang:dist_ctrl_get_data_notification/1
+bif erlang:dist_ctrl_get_opt/2
+bif erlang:dist_ctrl_set_opt/3
 
 # Static native functions in erts_internal
 bif erts_internal:port_info/1
@@ -411,6 +413,7 @@ bif re:compile/1
 bif re:compile/2
 bif re:run/2
 bif re:run/3
+bif re:internal_run/4
 
 #
 # Bifs in lists module.
@@ -435,6 +438,7 @@ bif erts_debug:set_internal_state/2
 bif erts_debug:display/1
 bif erts_debug:dist_ext_to_term/2
 bif erts_debug:instructions/0
+bif erts_debug:interpreter_size/0
 bif erts_debug:dirty_cpu/2
 bif erts_debug:dirty_io/2
 bif erts_debug:dirty/3
@@ -481,8 +485,8 @@ bif erlang:list_to_existing_atom/1
 #
 ubif erlang:is_bitstring/1
 ubif erlang:tuple_size/1
-gcbif erlang:byte_size/1
-gcbif erlang:bit_size/1
+ubif erlang:byte_size/1
+ubif erlang:bit_size/1
 bif erlang:list_to_bitstring/1
 bif erlang:bitstring_to_list/1
 
@@ -534,8 +538,8 @@ bif erlang:binary_to_term/2
 #
 # The searching/splitting/substituting thingies
 #
-gcbif erlang:binary_part/2
-gcbif erlang:binary_part/3
+ubif erlang:binary_part/2
+ubif erlang:binary_part/3
 
 bif binary:compile_pattern/1
 bif binary:match/2
@@ -623,14 +627,13 @@ bif io:printable_range/0
 bif re:inspect/2
 
 ubif erlang:is_map/1
-gcbif erlang:map_size/1
+ubif erlang:map_size/1
 bif maps:find/2
 bif maps:get/2
 bif maps:from_list/1
 bif maps:is_key/2
 bif maps:keys/1
 bif maps:merge/2
-bif maps:new/0
 bif maps:put/3
 bif maps:remove/2
 bif maps:update/3
@@ -672,8 +675,8 @@ bif maps:take/2
 # New in 20.0
 #
 
-gcbif erlang:floor/1
-gcbif erlang:ceil/1
+ubif erlang:floor/1
+ubif erlang:ceil/1
 bif math:floor/1
 bif math:ceil/1
 bif math:fmod/2
@@ -725,3 +728,17 @@ bif erts_internal:counters_get/2
 bif erts_internal:counters_add/3
 bif erts_internal:counters_put/3
 bif erts_internal:counters_info/1
+
+#
+# New in 21.2.3
+#
+
+bif erts_internal:spawn_system_process/3
+
+#
+# New in 21.3
+#
+
+bif erlang:integer_to_list/2
+bif erlang:integer_to_binary/2
+bif persistent_term:get/2
diff --git a/erts/emulator/beam/bif_instrs.tab b/erts/emulator/beam/bif_instrs.tab
index 00854471a9..8e0caa38a3 100644
--- a/erts/emulator/beam/bif_instrs.tab
+++ b/erts/emulator/beam/bif_instrs.tab
@@ -31,13 +31,20 @@
 
 CALL_GUARD_BIF(BF, TmpReg, Dst) {
     Eterm result;
+#ifdef DEBUG
+    Eterm* orig_htop = HTOP;
+    Eterm* orig_stop = E;
+#endif
 
     ERTS_DBG_CHK_REDS(c_p, FCALLS);
     c_p->fcalls = FCALLS;
     PROCESS_MAIN_CHK_LOCKS(c_p);
     ASSERT(!ERTS_PROC_IS_EXITING(c_p));
     ERTS_CHK_MBUF_SZ(c_p);
+    DEBUG_SWAPOUT;
     result = (*$BF)(c_p, $TmpReg, I);
+    DEBUG_SWAPIN;
+    ASSERT(orig_htop == HTOP && orig_stop == E);
     ERTS_CHK_MBUF_SZ(c_p);
     ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
     ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
@@ -51,237 +58,259 @@ CALL_GUARD_BIF(BF, TmpReg, Dst) {
     }
 }
 
-// Guard BIF in head.  On failure, ignore the error and jump
-// to the code for the next clause.  We don't support tracing
+// Guard BIF in head. On failure, ignore the error and jump
+// to the code for the next clause. We don't support tracing
 // of guard BIFs.
 
-bif1(Fail, Bif, Src, Dst) {
+i_bif1 := i_bif.fetch0.call;
+i_bif2 := i_bif.fetch1.fetch0.call;
+i_bif3 := i_bif.fetch2.fetch1.fetch0.call;
+
+i_bif.head() {
     ErtsBifFunc bf;
-    Eterm tmp_reg[1];
+    Eterm tmp_reg[3];
+}
 
+i_bif.fetch0(Src) {
     tmp_reg[0] = $Src;
-    bf = (BifFunction) $Bif;
-    $CALL_GUARD_BIF(bf, tmp_reg, $Dst);
-
-    $FAIL($Fail);
 }
 
-//
-// Guard BIF in body.  It can fail like any BIF.  No trace support.
-//
+i_bif.fetch1(Src) {
+    tmp_reg[1] = $Src;
+}
 
-bif1_body(Bif, Src, Dst) {
-    ErtsBifFunc bf;
-    Eterm tmp_reg[1];
+i_bif.fetch2(Src) {
+    tmp_reg[2] = $Src;
+}
 
-    tmp_reg[0] = $Src;
+i_bif.call(Fail, Bif, Dst) {
     bf = (BifFunction) $Bif;
     $CALL_GUARD_BIF(bf, tmp_reg, $Dst);
 
-    reg[0] = tmp_reg[0];
-    SWAPOUT;
-    I = handle_error(c_p, I, reg, ubif2mfa((void *) bf));
-    goto post_error_handling;
+    $FAIL($Fail);
 }
 
 //
-// Guard bif in guard with two arguments ('and'/2, 'or'/2, 'xor'/2).
+// Guard BIF in body. It can fail like any BIF. No trace support.
 //
 
-i_bif2(Fail, Bif, Src1, Src2, Dst) {
-    Eterm tmp_reg[2];
+i_bif1_body := i_bif_body.fetch0.call;
+i_bif2_body := i_bif_body.fetch1.fetch0.call;
+i_bif3_body := i_bif_body.fetch2.fetch1.fetch0.call;
+
+i_bif_body.head() {
     ErtsBifFunc bf;
+    Eterm tmp_reg[3];
+}
 
-    tmp_reg[0] = $Src1;
-    tmp_reg[1] = $Src2;
-    bf = (ErtsBifFunc) $Bif;
-    $CALL_GUARD_BIF(bf, tmp_reg, $Dst);
-    $FAIL($Fail);
+i_bif_body.fetch0(Src) {
+    tmp_reg[0] = $Src;
 }
 
-//
-// Guard bif in body with two arguments ('and'/2, 'or'/2, 'xor'/2).
-//
+i_bif_body.fetch1(Src) {
+    tmp_reg[1] = $Src;
+}
 
-i_bif2_body(Bif, Src1, Src2, Dst) {
-    Eterm tmp_reg[2];
-    ErtsBifFunc bf;
+i_bif_body.fetch2(Src) {
+    tmp_reg[2] = $Src;
+}
 
-    tmp_reg[0] = $Src1;
-    tmp_reg[1] = $Src2;
-    bf = (ErtsBifFunc) $Bif;
+i_bif_body.call(Bif, Dst) {
+    bf = (BifFunction) $Bif;
     $CALL_GUARD_BIF(bf, tmp_reg, $Dst);
+
     reg[0] = tmp_reg[0];
     reg[1] = tmp_reg[1];
+    reg[2] = tmp_reg[2];
     SWAPOUT;
     I = handle_error(c_p, I, reg, ubif2mfa((void *) bf));
     goto post_error_handling;
 }
 
 //
-// Garbage-collecting BIF with one argument in either guard or body.
+// length/1 is the only guard BIF that does not execute in constant
+// time. Here follows special instructions to allow the calculation of
+// the list length to be broken in several chunks to avoid hogging
+// the scheduler for a long time.
 //
 
-i_gc_bif1(Fail, Bif, Src, Live, Dst) {
-    typedef Eterm (*GcBifFunction)(Process*, Eterm*, Uint);
-    GcBifFunction bf;
-    Eterm result;
-    Uint live = (Uint) $Live;
+i_length_setup(Live, Src) {
+    Uint live = $Live;
+    Eterm src = $Src;
 
-    x(live) = $Src;
-    bf = (GcBifFunction) $Bif;
-    ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    c_p->fcalls = FCALLS;
-    SWAPOUT;
-    PROCESS_MAIN_CHK_LOCKS(c_p);
-    ERTS_UNREQ_PROC_MAIN_LOCK(c_p);
-    ERTS_CHK_MBUF_SZ(c_p);
-    result = (*bf)(c_p, reg, live);
-    ERTS_CHK_MBUF_SZ(c_p);
-    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
-    ERTS_REQ_PROC_MAIN_LOCK(c_p);
-    PROCESS_MAIN_CHK_LOCKS(c_p);
-    SWAPIN;
-    ERTS_HOLE_CHECK(c_p);
-    FCALLS = c_p->fcalls;
-    ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    if (ERTS_LIKELY(is_value(result))) {
-        $REFRESH_GEN_DEST();
-        $Dst = result;
-        $NEXT0();
-    }
-    if (ERTS_LIKELY($Fail != 0)) { /* Handle error in guard. */
-        $JUMP($Fail);
-    }
+    reg[live] = src;
+    reg[live+1] = make_small(0);
+    reg[live+2] = src;
 
-    /* Handle error in body. */
-    x(0) = x(live);
-    I = handle_error(c_p, I, reg, gcbif2mfa((void *) bf));
-    goto post_error_handling;
+    /* This instruction is always followed by i_length */
+    SET_I($NEXT_INSTRUCTION);
+    goto i_length_start__;
+    //| -no_next
 }
 
 //
-// Garbage-collecting BIF with two arguments in either guard or body.
+// This instruction can be executed one or more times. When entering
+// this instruction, the X registers have the following contents:
+//
+// reg[live+0] The remainder of the list.
+// reg[live+1] The length so far (tagged integer).
+// reg[live+2] The original list. Only used if an error is generated
+//             (if the final tail of the list is not []).
 //
 
-i_gc_bif2(Fail, Bif, Live, Src1, Src2, Dst) {
-    typedef Eterm (*GcBifFunction)(Process*, Eterm*, Uint);
-    GcBifFunction bf;
-    Eterm result;
-    Uint live = (Uint) $Live;
+i_length := i_length.start.execute;
 
-    /*
-     * XXX This calling convention does not make sense. 'live'
-     * should point out the first argument, not the second
-     * (i.e. 'live' should not be incremented below).
-     */
-    x(live) = $Src1;
-    x(live+1) = $Src2;
-    live++;
+i_length.start() {
+ i_length_start__:
+    ;
+}
+
+i_length.execute(Fail, Live, Dst) {
+    Eterm result;
+    Uint live;
 
-    bf = (GcBifFunction) $Bif;
     ERTS_DBG_CHK_REDS(c_p, FCALLS);
     c_p->fcalls = FCALLS;
-    SWAPOUT;
     PROCESS_MAIN_CHK_LOCKS(c_p);
-    ERTS_UNREQ_PROC_MAIN_LOCK(c_p);
+    ASSERT(!ERTS_PROC_IS_EXITING(c_p));
     ERTS_CHK_MBUF_SZ(c_p);
-    result = (*bf)(c_p, reg, live);
+    DEBUG_SWAPOUT;
+
+    live = $Live;
+    result = erts_trapping_length_1(c_p, reg+live);
+
+    DEBUG_SWAPIN;
     ERTS_CHK_MBUF_SZ(c_p);
+    ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
     ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
-    ERTS_REQ_PROC_MAIN_LOCK(c_p);
     PROCESS_MAIN_CHK_LOCKS(c_p);
-    SWAPIN;
     ERTS_HOLE_CHECK(c_p);
     FCALLS = c_p->fcalls;
     ERTS_DBG_CHK_REDS(c_p, FCALLS);
     if (ERTS_LIKELY(is_value(result))) {
+        /* Successful calculation of the list length. */
         $REFRESH_GEN_DEST();
         $Dst = result;
         $NEXT0();
+    } else if (c_p->freason == TRAP) {
+        /*
+         * Good so far, but there is more work to do. Yield.
+         */
+        $SET_CP_I_ABS(I);
+        SWAPOUT;
+        c_p->arity = live + 3;
+        c_p->current = NULL;
+        goto context_switch3;
+    } else {
+        /* Error. */
+        $BIF_ERROR_ARITY_1($Fail, BIF_length_1, reg[live+2]);
     }
-
-    if (ERTS_LIKELY($Fail != 0)) { /* Handle error in guard. */
-        $JUMP($Fail);
-    }
-
-    /* Handle error in body. */
-    live--;
-    x(0) = x(live);
-    x(1) = x(live+1);
-    I = handle_error(c_p, I, reg, gcbif2mfa((void *) bf));
-    goto post_error_handling;
+    //| -no_next
 }
 
 //
-// Garbage-collecting BIF with three arguments in either guard or body.
+// Call a BIF, store the result in x(0) and transfer control to the
+// next instruction.
 //
-
-i_gc_bif3(Fail, Bif, Live, Src2, Src3, Dst) {
-    typedef Eterm (*GcBifFunction)(Process*, Eterm*, Uint);
-    GcBifFunction bf;
+call_bif(Exp) {
+    ErtsBifFunc bf;
     Eterm result;
-    Uint live = (Uint) $Live;
+    ErlHeapFragment *live_hf_end;
+    Export *export = (Export*) $Exp;
 
-    /*
-     * XXX This calling convention does not make sense. 'live'
-     * should point out the first argument, not the third
-     * (i.e. 'live' should not be incremented below).
-     */
-    x(live) = x(SCRATCH_X_REG);
-    x(live+1) = $Src2;
-    x(live+2) = $Src3;
-    live += 2;
+    if (!((FCALLS - 1) > 0 || (FCALLS-1) > neg_o_reds)) {
+        /*
+         * If we have run out of reductions, do a context
+         * switch before calling the BIF.
+         */
+        c_p->arity = GET_BIF_ARITY(export);
+        c_p->current = &export->info.mfa;
+        goto context_switch3;
+    }
+
+    ERTS_MSACC_SET_BIF_STATE_CACHED_X(GET_BIF_MODULE(export),
+                                      GET_BIF_ADDRESS(export));
 
-    bf = (GcBifFunction) $Bif;
+    bf = GET_BIF_ADDRESS(export);
+
+    PRE_BIF_SWAPOUT(c_p);
     ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    c_p->fcalls = FCALLS;
-    SWAPOUT;
-    PROCESS_MAIN_CHK_LOCKS(c_p);
-    ERTS_UNREQ_PROC_MAIN_LOCK(c_p);
+    c_p->fcalls = FCALLS - 1;
+    if (FCALLS <= 0) {
+        save_calls(c_p, export);
+    }
+    ASSERT(!ERTS_PROC_IS_EXITING(c_p));
+    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
+    live_hf_end = c_p->mbuf;
     ERTS_CHK_MBUF_SZ(c_p);
-    result = (*bf)(c_p, reg, live);
+    result = (*bf)(c_p, reg, I);
     ERTS_CHK_MBUF_SZ(c_p);
+    ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
     ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
+    ERTS_HOLE_CHECK(c_p);
     ERTS_REQ_PROC_MAIN_LOCK(c_p);
+    if (ERTS_IS_GC_DESIRED(c_p)) {
+        Uint arity = GET_BIF_ARITY(export);
+        result = erts_gc_after_bif_call_lhf(c_p, live_hf_end, result,
+                                            reg, arity);
+        E = c_p->stop;
+    }
     PROCESS_MAIN_CHK_LOCKS(c_p);
-    SWAPIN;
-    ERTS_HOLE_CHECK(c_p);
+    HTOP = HEAP_TOP(c_p);
     FCALLS = c_p->fcalls;
     ERTS_DBG_CHK_REDS(c_p, FCALLS);
+
+    /*
+     * We have to update the cache if we are enabled in order
+     * to make sure no bookkeeping is done after we disabled
+     * msacc. We don't always do this as it is quite expensive.
+     */
+    if (ERTS_MSACC_IS_ENABLED_CACHED_X()) {
+        ERTS_MSACC_UPDATE_CACHE_X();
+    }
+    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_EMULATOR);
     if (ERTS_LIKELY(is_value(result))) {
-        $REFRESH_GEN_DEST();
-        $Dst = result;
+        r(0) = result;
+        CHECK_TERM(r(0));
         $NEXT0();
+    } else if (c_p->freason == TRAP) {
+        /*
+         * Set the continuation pointer to return to next
+         * instruction after the trap (either by a return from
+         * erlang code or by nif_bif.epilogue() when the BIF
+         * is done).
+         */
+        SET_CP(c_p, $NEXT_INSTRUCTION);
+        SET_I(c_p->i);
+        SWAPIN;
+        Dispatch();
     }
 
-    /* Handle error in guard. */
-    if (ERTS_LIKELY($Fail != 0)) {
-        $JUMP($Fail);
-    }
-
-    /* Handle error in body. */
-    live -= 2;
-    x(0) = x(live);
-    x(1) = x(live+1);
-    x(2) = x(live+2);
-    I = handle_error(c_p, I, reg, gcbif2mfa((void *) bf));
+    /*
+     * Error handling.  SWAPOUT is not needed because it was done above.
+     */
+    ASSERT(c_p->stop == E);
+    I = handle_error(c_p, I, reg, &export->info.mfa);
     goto post_error_handling;
+    //| -no_next
 }
 
 //
-// The most general BIF call.  The BIF may build any amount of data
-// on the heap.  The result is always returned in r(0).
+// Call a BIF tail-recursively, storing the result in x(0) and doing
+// a return to the continuation poiner (c_p->cp).
 //
-call_bif(Exp) {
+
+call_bif_only(Exp) {
     ErtsBifFunc bf;
     Eterm result;
     ErlHeapFragment *live_hf_end;
     Export *export = (Export*) $Exp;
 
     if (!((FCALLS - 1) > 0 || (FCALLS-1) > neg_o_reds)) {
-        /* If we have run out of reductions, we do a context
-           switch before calling the bif */
+        /*
+         * If we have run out of reductions, do a context
+         * switch before calling the BIF.
+         */
         c_p->arity = GET_BIF_ARITY(export);
         c_p->current = &export->info.mfa;
         goto context_switch3;
@@ -318,19 +347,28 @@ call_bif(Exp) {
     HTOP = HEAP_TOP(c_p);
     FCALLS = c_p->fcalls;
     ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    /* We have to update the cache if we are enabled in order
-       to make sure no book keeping is done after we disabled
-       msacc. We don't always do this as it is quite expensive. */
+
+    /*
+     * We have to update the cache if we are enabled in order
+     * to make sure no bookkeeping is done after we disabled
+     * msacc. We don't always do this as it is quite expensive.
+     */
     if (ERTS_MSACC_IS_ENABLED_CACHED_X()) {
         ERTS_MSACC_UPDATE_CACHE_X();
     }
     ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_EMULATOR);
     if (ERTS_LIKELY(is_value(result))) {
+        /*
+         * Success. Store the result and return to the caller.
+         */
         r(0) = result;
         CHECK_TERM(r(0));
-        $NEXT0();
+        $return();
     } else if (c_p->freason == TRAP) {
-        SET_CP(c_p, I+2);
+        /*
+         * Dispatch to a trap. When the trap is done, a jump
+         * to the continuation pointer (c_p->cp) will be done.
+         */
         SET_I(c_p->i);
         SWAPIN;
         Dispatch();
@@ -342,6 +380,7 @@ call_bif(Exp) {
     ASSERT(c_p->stop == E);
     I = handle_error(c_p, I, reg, &export->info.mfa);
     goto post_error_handling;
+    //| -no_next
 }
 
 //
@@ -374,7 +413,7 @@ send() {
         r(0) = result;
         CHECK_TERM(r(0));
     } else if (c_p->freason == TRAP) {
-        SET_CP(c_p, I+1);
+        SET_CP(c_p, $NEXT_INSTRUCTION);
         SET_I(c_p->i);
         SWAPIN;
         Dispatch();
diff --git a/erts/emulator/beam/big.c b/erts/emulator/beam/big.c
index 84338769e0..522f50287a 100644
--- a/erts/emulator/beam/big.c
+++ b/erts/emulator/beam/big.c
@@ -429,6 +429,7 @@
 static const byte digits_per_sint_lookup[36-1];
 static const byte digits_per_small_lookup[36-1];
 static const Sint largest_power_of_base_lookup[36-1];
+static const double lg2_lookup[36-1];
 
 static ERTS_INLINE byte get_digits_per_signed_int(Uint base) {
     return digits_per_sint_lookup[base-2];
@@ -442,6 +443,10 @@ static ERTS_INLINE Sint get_largest_power_of_base(Uint base) {
     return largest_power_of_base_lookup[base-2];
 }
 
+static ERTS_INLINE double lookup_log2(Uint base) {
+    return lg2_lookup[base - 2];
+}
+
 /*
 ** compare two number vectors
 */
@@ -668,27 +673,25 @@ static dsize_t I_mul(ErtsDigit* x, dsize_t xl, ErtsDigit* y, dsize_t yl, ErtsDig
 
 static dsize_t I_sqr(ErtsDigit* x, dsize_t xl, ErtsDigit* r)
 {
-    ErtsDigit d_next = *x;
     ErtsDigit d;
     ErtsDigit* r0 = r;
     ErtsDigit* s = r;
 
     if ((r + xl) == x)	/* "Inline" operation */
 	*x = 0;
-    x++;
 	
     while(xl--) {
-	ErtsDigit* y = x;
+	ErtsDigit* y;
 	ErtsDigit y_0 = 0, y_1 = 0, y_2 = 0, y_3 = 0;
 	ErtsDigit b0, b1;
 	ErtsDigit z0, z1, z2;
 	ErtsDigit t;
 	dsize_t y_l = xl;
-		
+
+        d = *x;
+        x++;
+        y = x;
 	s = r;
-	d = d_next;
-	d_next = *x; 
-	x++;
 
 	DMUL(d, d, b1, b0);
 	DSUMc(*s, b0, y_3, t);
@@ -1159,8 +1162,11 @@ static dsize_t I_band(ErtsDigit* x, dsize_t xl, short xsgn,
 		*r++ = ~c1 & ~c2;
 		x++; y++;
 	    }
-	    while(xl--)
-		*r++ = ~*x++;
+	    while(xl--) {
+                DSUBb(*x,0,b1,c1);
+                *r++ = ~c1;
+		x++;
+            }
 	}
     }
     return I_btrail(r0, r, sign);
@@ -1719,23 +1725,23 @@ double_to_big(double x, Eterm *heap, Uint hsz)
 
 
 /*
- ** Estimate the number of decimal digits (include sign)
+ ** Estimate the number of digits in given base (include sign)
  */
-int big_decimal_estimate(Wterm x)
+int big_integer_estimate(Wterm x, Uint base)
 {
     Eterm* xp = big_val(x);
     int lg = I_lg(BIG_V(xp), BIG_SIZE(xp));
-    int lg10 = ((lg+1)*28/93)+1;
+    int lgBase = ((lg + 1) / lookup_log2(base)) + 1;
 
-    if (BIG_SIGN(xp)) lg10++;	/* add sign */
-    return lg10+1;		/* add null */
+    if (BIG_SIGN(xp)) lgBase++;	/* add sign */
+    return lgBase + 1;		/* add null */
 }
 
 /*
-** Convert a bignum into a string of decimal numbers
+** Convert a bignum into a string of numbers in given base
 */
-
-static Uint write_big(Wterm x, void (*write_func)(void *, char), void *arg)
+static Uint write_big(Wterm x, int base, void (*write_func)(void *, char),
+                      void *arg)
 {
     Eterm* xp = big_val(x);
     ErtsDigit* dx = BIG_V(xp);
@@ -1743,48 +1749,72 @@ static Uint write_big(Wterm x, void (*write_func)(void *, char), void *arg)
     short sign = BIG_SIGN(xp);
     ErtsDigit rem;
     Uint n = 0;
-    const Uint digits_per_Sint = get_digits_per_signed_int(10);
-    const Sint largest_pow_of_base = get_largest_power_of_base(10);
+    const Uint digits_per_Sint = get_digits_per_signed_int(base);
+    const Sint largest_pow_of_base = get_largest_power_of_base(base);
 
     if (xl == 1 && *dx < largest_pow_of_base) {
-	rem = *dx;
-	if (rem == 0) {
-	    (*write_func)(arg, '0'); n++;
-	} else {
-	    while(rem) {
-		(*write_func)(arg, (rem % 10) + '0'); n++;
-		rem /= 10;
-	    }
-	}
+        rem = *dx;
+        if (rem == 0) {
+            (*write_func)(arg, '0'); n++;
+        } else {
+            while(rem) {
+                int digit = rem % base;
+
+                if (digit < 10) {
+                    (*write_func)(arg, digit + '0'); n++;
+                } else {
+                    (*write_func)(arg, 'A' + (digit - 10)); n++;
+                }
+
+                rem /= base;
+            }
+        }
     } else {
-	ErtsDigit* tmp  = (ErtsDigit*) erts_alloc(ERTS_ALC_T_TMP,
-					      sizeof(ErtsDigit)*xl);
-	dsize_t tmpl = xl;
+        ErtsDigit* tmp = (ErtsDigit*) erts_alloc(ERTS_ALC_T_TMP,
+                                                 sizeof(ErtsDigit) * xl);
+        dsize_t tmpl = xl;
 
-	MOVE_DIGITS(tmp, dx, xl);
+        MOVE_DIGITS(tmp, dx, xl);
 
-	while(1) {
+        while(1) {
             tmpl = D_div(tmp, tmpl, largest_pow_of_base, tmp, &rem);
-	    if (tmpl == 1 && *tmp == 0) {
-		while(rem) {
-		    (*write_func)(arg, (rem % 10)+'0'); n++;
-		    rem /= 10;
-		}
-		break;
-	    } else {
+
+            if (tmpl == 1 && *tmp == 0) {
+                while(rem) {
+                    int digit = rem % base;
+
+                    if (digit < 10) {
+                        (*write_func)(arg, digit + '0'); n++;
+                    } else {
+                        (*write_func)(arg, 'A' + (digit - 10)); n++;
+                    }
+
+                    rem /= base;
+                }
+                break;
+            } else {
                 Uint i = digits_per_Sint;
-		while(i--) {
-		    (*write_func)(arg, (rem % 10)+'0'); n++;
-		    rem /= 10;
-		}
-	    }
-	}
-	erts_free(ERTS_ALC_T_TMP, (void *) tmp);
+
+                while(i--) {
+                    int digit = rem % base;
+
+                    if (digit < 10) {
+                        (*write_func)(arg, digit + '0'); n++;
+                    } else {
+                        (*write_func)(arg, 'A' + (digit - 10)); n++;
+                    }
+
+                    rem /= base;
+                }
+            }
+        }
+        erts_free(ERTS_ALC_T_TMP, (void *) tmp);
     }
 
     if (sign) {
-	(*write_func)(arg, '-'); n++;
+        (*write_func)(arg, '-'); n++;
     }
+
     return n;
 }
 
@@ -1801,12 +1831,12 @@ write_list(void *arg, char c)
     blp->hp += 2;
 }
 
-Eterm erts_big_to_list(Eterm x, Eterm **hpp)
+Eterm erts_big_to_list(Eterm x, int base, Eterm **hpp)
 {
     struct big_list__ bl;
     bl.hp = *hpp;
     bl.res = NIL;
-    write_big(x, write_list, (void *) &bl);
+    write_big(x, base, write_list, (void *) &bl);
     *hpp = bl.hp;
     return bl.res;
 }
@@ -1817,11 +1847,11 @@ write_string(void *arg, char c)
     *(--(*((char **) arg))) = c;
 }
 
-char *erts_big_to_string(Wterm x, char *buf, Uint buf_sz)
+char *erts_big_to_string(Wterm x, int base, char *buf, Uint buf_sz)
 {
     char *big_str = buf + buf_sz - 1;
     *big_str = '\0';
-    write_big(x, write_string, (void *) &big_str);
+    write_big(x, base, write_string, (void*)&big_str);
     ASSERT(buf <= big_str && big_str <= buf + buf_sz - 1);
     return big_str;
 }
@@ -1830,11 +1860,11 @@ char *erts_big_to_string(Wterm x, char *buf, Uint buf_sz)
  * e.g. 1 bsl 64 -> "18446744073709551616"
  */
 
-Uint erts_big_to_binary_bytes(Eterm x, char *buf, Uint buf_sz)
+Uint erts_big_to_binary_bytes(Eterm x, int base, char *buf, Uint buf_sz)
 {
     char *big_str = buf + buf_sz;
     Uint n;
-    n = write_big(x, write_string, (void *) &big_str);
+    n = write_big(x, base, write_string, (void *) &big_str);
     ASSERT(buf <= big_str && big_str <= buf + buf_sz);
     return n;
 }
@@ -2577,9 +2607,6 @@ static const double lg2_lookup[36-1] = {
     4.32193, 4.39232, 4.45943, 4.52356, 4.58496, 4.64386, 4.70044, 4.75489,
     4.80735, 4.85798, 4.90689, 4.9542, 5.0, 5.04439, 5.08746, 5.12928, 5.16993
 };
-static ERTS_INLINE double lookup_log2(Uint base) {
-    return lg2_lookup[base - 2];
-}
 
 /*
  * How many digits can fit into a signed int (Sint) for given base, we take
diff --git a/erts/emulator/beam/big.h b/erts/emulator/beam/big.h
index 7556205063..ad19cce395 100644
--- a/erts/emulator/beam/big.h
+++ b/erts/emulator/beam/big.h
@@ -42,7 +42,7 @@ typedef Uint16   ErtsHalfDigit;
 #undef  BIG_HAVE_DOUBLE_DIGIT
 typedef Uint32   ErtsHalfDigit;
 #else
-#error "can not determine machine size"
+#error "cannot determine machine size"
 #endif
 
 typedef Uint  dsize_t;	 /* Vector size type */
@@ -81,7 +81,11 @@ typedef Uint  dsize_t;	 /* Vector size type */
  * a Uint64 argument. Therefore, we must test the size of the argument
  * to ensure that the cast does not discard the high-order 32 bits.
  */
-#define _IS_SSMALL32(x) (((Uint32) ((((x)) >> (SMALL_BITS-1)) + 1)) < 2)
+#if defined(ARCH_32)
+#  define _IS_SSMALL32(x) (((Uint32) ((((x)) >> (SMALL_BITS-1)) + 1)) < 2)
+#else
+#  define _IS_SSMALL32(x) (1)
+#endif
 #define _IS_SSMALL64(x) (((Uint64) ((((x)) >> (SMALL_BITS-1)) + 1)) < 2)
 #define IS_SSMALL(x) (sizeof(x) == sizeof(Uint32) ? _IS_SSMALL32(x) : _IS_SSMALL64(x))
 
@@ -119,10 +123,10 @@ typedef Uint  dsize_t;	 /* Vector size type */
 
 #endif
 
-int big_decimal_estimate(Wterm);
-Eterm erts_big_to_list(Eterm, Eterm**);
-char *erts_big_to_string(Wterm x, char *buf, Uint buf_sz);
-Uint erts_big_to_binary_bytes(Eterm x, char *buf, Uint buf_sz);
+int big_integer_estimate(Wterm, Uint base);
+Eterm erts_big_to_list(Eterm, int base, Eterm**);
+char *erts_big_to_string(Wterm x, int base, char *buf, Uint buf_sz);
+Uint erts_big_to_binary_bytes(Eterm x, int base, char *buf, Uint buf_sz);
 
 Eterm small_times(Sint, Sint, Eterm*);
 
diff --git a/erts/emulator/beam/binary.c b/erts/emulator/beam/binary.c
index 6a349764b2..4ddf59092a 100644
--- a/erts/emulator/beam/binary.c
+++ b/erts/emulator/beam/binary.c
@@ -322,40 +322,102 @@ BIF_RETTYPE binary_to_integer_2(BIF_ALIST_2)
 
 }
 
+static Eterm integer_to_binary(Process *c_p, Eterm num, int base)
+{
+    Eterm res;
+
+    if (is_small(num)) {
+        char s[128];
+        char *c = s;
+        Uint digits;
+
+        digits = Sint_to_buf(signed_val(num), base, &c, sizeof(s));
+        res = new_binary(c_p, (byte*)c, digits);
+    } else {
+        const int DIGITS_PER_RED = 16;
+        Uint digits, n;
+        byte *bytes;
+
+        digits = big_integer_estimate(num, base);
+
+        if ((digits / DIGITS_PER_RED) > ERTS_BIF_REDS_LEFT(c_p)) {
+            ErtsSchedulerData *esdp = erts_get_scheduler_data();
+
+            /* This could take a very long time, tell the caller to reschedule
+             * us to a dirty CPU scheduler if we aren't already on one. */
+            if (esdp->type == ERTS_SCHED_NORMAL) {
+                return THE_NON_VALUE;
+            }
+        } else {
+            BUMP_REDS(c_p, digits / DIGITS_PER_RED);
+        }
+
+        bytes = (byte*)erts_alloc(ERTS_ALC_T_TMP, sizeof(byte) * digits);
+        n = erts_big_to_binary_bytes(num, base, (char*)bytes, digits);
+        res = new_binary(c_p, bytes + digits - n, n);
+        erts_free(ERTS_ALC_T_TMP, (void*)bytes);
+    }
+
+    return res;
+}
+
 BIF_RETTYPE integer_to_binary_1(BIF_ALIST_1)
-{   
-    Uint size;
+{
     Eterm res;
 
     if (is_not_integer(BIF_ARG_1)) {
-	BIF_ERROR(BIF_P, BADARG);
+        BIF_ERROR(BIF_P, BADARG);
     }
 
-    if (is_small(BIF_ARG_1)) {
-	char *c;
-	struct Sint_buf ibuf;
+    res = integer_to_binary(BIF_P, BIF_ARG_1, 10);
+
+    if (is_non_value(res)) {
+        Eterm args[1];
+        args[0] = BIF_ARG_1;
+        return erts_schedule_bif(BIF_P,
+                                 args,
+                                 BIF_I,
+                                 integer_to_binary_1,
+                                 ERTS_SCHED_DIRTY_CPU,
+                                 am_erlang,
+                                 am_integer_to_binary,
+                                 1);
+    }
 
-	/* Enhancement: If we can calculate the buffer size exactly
-	 * we could avoid an unnecessary copy of buffers.
-	 * Useful if size determination is faster than a copy.
-	 */
-	c = Sint_to_buf(signed_val(BIF_ARG_1), &ibuf);
-	size = sys_strlen(c);
-	res = new_binary(BIF_P, (byte *)c, size);
-    } else {
-	byte* bytes;
-	Uint n = 0;
+    return res;
+}
 
-	/* Here we also have multiple copies of buffers
-	 * due to new_binary interface
-	 */
-	size = big_decimal_estimate(BIF_ARG_1) - 1; /* remove null */
-	bytes = (byte*) erts_alloc(ERTS_ALC_T_TMP, sizeof(byte)*size);
-	n = erts_big_to_binary_bytes(BIF_ARG_1, (char *)bytes, size);
-	res = new_binary(BIF_P, bytes + size - n, n);
-	erts_free(ERTS_ALC_T_TMP, (void *) bytes);
+BIF_RETTYPE integer_to_binary_2(BIF_ALIST_2)
+{
+    Eterm res;
+    SWord base;
+
+    if (is_not_integer(BIF_ARG_1) || is_not_small(BIF_ARG_2)) {
+        BIF_ERROR(BIF_P, BADARG);
+    }
+
+    base = signed_val(BIF_ARG_2);
+    if (base < 2 || base > 36) {
+        BIF_ERROR(BIF_P, BADARG);
+    }
+
+    res = integer_to_binary(BIF_P, BIF_ARG_1, base);
+
+    if (is_non_value(res)) {
+        Eterm args[2];
+        args[0] = BIF_ARG_1;
+        args[1] = BIF_ARG_2;
+        return erts_schedule_bif(BIF_P,
+                                 args,
+                                 BIF_I,
+                                 integer_to_binary_2,
+                                 ERTS_SCHED_DIRTY_CPU,
+                                 am_erlang,
+                                 am_integer_to_binary,
+                                 2);
     }
-    BIF_RET(res);
+
+    return res;
 }
 
 #define ERTS_B2L_BYTES_PER_REDUCTION 256
@@ -1091,51 +1153,47 @@ BIF_RETTYPE list_to_bitstring_1(BIF_ALIST_1)
 
 BIF_RETTYPE split_binary_2(BIF_ALIST_2)
 {
-    Uint pos;
-    ErlSubBin* sb1;
-    ErlSubBin* sb2;
-    size_t orig_size;
-    Eterm orig;
-    Uint offset;
-    Uint bit_offset;
-    Uint bit_size;
-    Eterm* hp;
+    size_t orig_size, left_size, right_size;
+    Uint byte_offset, bit_offset, bit_size;
+    Uint split_at;
+
+    Eterm *hp, *hp_end;
+    Eterm left, right;
+    Eterm real_bin;
+    Eterm result;
+    byte *bptr;
 
     if (is_not_binary(BIF_ARG_1)) {
-	goto error;
-    }
-    if (!term_to_Uint(BIF_ARG_2, &pos)) {
-	goto error;
-    }
-    if ((orig_size = binary_size(BIF_ARG_1)) < pos) {
-	goto error;
+        BIF_ERROR(BIF_P, BADARG);
+    } else if (!term_to_Uint(BIF_ARG_2, &split_at)) {
+        BIF_ERROR(BIF_P, BADARG);
+    } else if ((orig_size = binary_size(BIF_ARG_1)) < split_at) {
+        BIF_ERROR(BIF_P, BADARG);
     }
-    hp = HAlloc(BIF_P, 2*ERL_SUB_BIN_SIZE+3);
-    ERTS_GET_REAL_BIN(BIF_ARG_1, orig, offset, bit_offset, bit_size);
-    sb1 = (ErlSubBin *) hp;
-    sb1->thing_word = HEADER_SUB_BIN;
-    sb1->size = pos;
-    sb1->offs = offset;
-    sb1->orig = orig;
-    sb1->bitoffs = bit_offset;
-    sb1->bitsize = 0;
-    sb1->is_writable = 0;
-    hp += ERL_SUB_BIN_SIZE;
-
-    sb2 = (ErlSubBin *) hp;
-    sb2->thing_word = HEADER_SUB_BIN;
-    sb2->size = orig_size - pos;
-    sb2->offs = offset + pos;
-    sb2->orig = orig;
-    sb2->bitoffs = bit_offset;
-    sb2->bitsize = bit_size;	/* The extra bits go into the second binary. */
-    sb2->is_writable = 0;
-    hp += ERL_SUB_BIN_SIZE;
-
-    return TUPLE2(hp, make_binary(sb1), make_binary(sb2));
-    
-    error:
-	BIF_ERROR(BIF_P, BADARG);
+
+    left_size = split_at;
+    right_size = orig_size - split_at;
+
+    ERTS_GET_REAL_BIN(BIF_ARG_1, real_bin, byte_offset, bit_offset, bit_size);
+    bptr = binary_bytes(real_bin);
+
+    hp = HAlloc(BIF_P, EXTRACT_SUB_BIN_HEAP_NEED * 2 + 3);
+    hp_end = hp + (EXTRACT_SUB_BIN_HEAP_NEED * 2 + 3);
+
+    left = erts_extract_sub_binary(&hp, real_bin, bptr,
+                                   byte_offset * 8 + bit_offset,
+                                   left_size * 8);
+
+    right = erts_extract_sub_binary(&hp, real_bin, bptr,
+                                    (byte_offset + split_at) * 8 + bit_offset,
+                                    right_size * 8 + bit_size);
+
+    result = TUPLE2(hp, left, right);
+    hp += 3;
+
+    HRelease(BIF_P, hp_end, hp);
+
+    return result;
 }
 
 
diff --git a/erts/emulator/beam/break.c b/erts/emulator/beam/break.c
index 9ff52c92b8..6379e4e04d 100644
--- a/erts/emulator/beam/break.c
+++ b/erts/emulator/beam/break.c
@@ -39,6 +39,7 @@
 #include "erl_hl_timer.h"
 #include "erl_thr_progress.h"
 #include "erl_proc_sig_queue.h"
+#include "dist.h"
 
 /* Forward declarations -- should really appear somewhere else */
 static void process_killer(void);
@@ -74,6 +75,7 @@ port_info(fmtfn_t to, void *to_arg)
 void
 process_info(fmtfn_t to, void *to_arg)
 {
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
     int i, max = erts_ptab_max(&erts_proc);
     for (i = 0; i < max; i++) {
 	Process *p = erts_pix2proc(i);
@@ -81,11 +83,36 @@ process_info(fmtfn_t to, void *to_arg)
 	    /* Do not include processes with no heap,
 	     * they are most likely just created and has invalid data
 	     */
-	    if (!ERTS_PROC_IS_EXITING(p) && p->heap != NULL)
-		print_process_info(to, to_arg, p);
+	    if (p->heap != NULL) {
+                ErtsProcLocks locks = ((esdp && (p == esdp->current_process ||
+                                                 p == esdp->free_process))
+                                       ? ERTS_PROC_LOCK_MAIN : 0);
+		print_process_info(to, to_arg, p, locks);
+            }
 	}
     }
 
+    /* Look for FREE processes in the run-queues and dist entries.
+       These have been removed from the ptab but we still want them
+       in the crash dump for debugging. */
+
+    /* First loop through all run-queues */
+    for (i = 0; i < erts_no_schedulers + ERTS_NUM_DIRTY_RUNQS; i++) {
+        ErtsRunQueue *rq = ERTS_RUNQ_IX(i);
+        int j;
+        for (j = 0; j < ERTS_NO_PROC_PRIO_QUEUES; j++) {
+            Process *p = rq->procs.prio[j].first;
+            while (p) {
+                if (ERTS_PSFLG_FREE & erts_atomic32_read_acqb(&p->state))
+                    print_process_info(to, to_arg, p, 0);
+                p = p->next;
+            }
+        }
+    }
+
+    /* Then check all dist entries */
+    erts_dist_print_procs_suspended_on_de(to, to_arg);
+
     port_info(to, to_arg);
 }
 
@@ -101,13 +128,14 @@ process_killer(void)
 	rp = erts_pix2proc(i);
 	if (rp && rp->i != ENULL) {
 	    int br;
-	    print_process_info(ERTS_PRINT_STDOUT, NULL, rp);
+	    print_process_info(ERTS_PRINT_STDOUT, NULL, rp, 0);
 	    erts_printf("(k)ill (n)ext (r)eturn:\n");
 	    while(1) {
 		if ((j = sys_get_key(0)) <= 0)
 		    erts_exit(0, "");
 		switch(j) {
 		case 'k':
+                    ASSERT(erts_init_process_id != ERTS_INVALID_PID);
                     /* Send a 'kill' exit signal from init process */
                     erts_proc_sig_send_exit(NULL, erts_init_process_id,
                                             rp->common.id, am_kill, NIL,
@@ -128,7 +156,7 @@ typedef struct {
     void *to_arg;
 } PrintMonitorContext;
 
-static void doit_print_link(ErtsLink *lnk, void *vpcontext)
+static int doit_print_link(ErtsLink *lnk, void *vpcontext, Sint reds)
 {
     PrintMonitorContext *pcontext = vpcontext;
     fmtfn_t to = pcontext->to;
@@ -140,10 +168,11 @@ static void doit_print_link(ErtsLink *lnk, void *vpcontext)
     } else {
 	erts_print(to, to_arg, ", %T", lnk->other.item);
     }
+    return 1;
 }
     
 
-static void doit_print_monitor(ErtsMonitor *mon, void *vpcontext)
+static int doit_print_monitor(ErtsMonitor *mon, void *vpcontext, Sint reds)
 {
     ErtsMonitorData *mdp;
     PrintMonitorContext *pcontext = vpcontext;
@@ -195,17 +224,20 @@ static void doit_print_monitor(ErtsMonitor *mon, void *vpcontext)
         /* ignore other monitors... */
         break;
     }
+    return 1;
 }
-			       
+
 /* Display info about an individual Erlang process */
 void
-print_process_info(fmtfn_t to, void *to_arg, Process *p)
+print_process_info(fmtfn_t to, void *to_arg, Process *p, ErtsProcLocks orig_locks)
 {
     int garbing = 0;
     int running = 0;
+    int exiting = 0;
     Sint len;
     struct saved_calls *scb;
     erts_aint32_t state;
+    ErtsProcLocks locks = orig_locks;
 
     /* display the PID */
     erts_print(to, to_arg, "=proc:%T\n", p->common.id);
@@ -222,11 +254,30 @@ print_process_info(fmtfn_t to, void *to_arg, Process *p)
 			| ERTS_PSFLG_DIRTY_RUNNING))
         running = 1;
 
+    if (state & ERTS_PSFLG_EXITING)
+        exiting = 1;
+
+    if (!(locks & ERTS_PROC_LOCK_MAIN)) {
+        locks |= ERTS_PROC_LOCK_MAIN;
+        if (ERTS_IS_CRASH_DUMPING) {
+            if (erts_proc_trylock(p, locks)) {
+                /* crash dumping and main lock taken, this probably means that
+                   the process is doing a GC on a dirty-scheduler... so we cannot
+                   do erts_proc_sig_fetch as that would potentially cause a segfault */
+                locks = 0;
+            }
+        } else {
+            erts_proc_lock(p, locks);
+        }
+    } else {
+        ERTS_ASSERT(locks == ERTS_PROC_LOCK_MAIN && "Only main lock should be held");
+    }
+
     /*
      * If the process is registered as a global process, display the
      * registered name
      */
-    if (p->common.u.alive.reg)
+    if (!ERTS_PROC_IS_EXITING(p) && p->common.u.alive.reg)
 	erts_print(to, to_arg, "Name: %T\n", p->common.u.alive.reg->name);
 
     /*
@@ -251,13 +302,19 @@ print_process_info(fmtfn_t to, void *to_arg, Process *p)
 
     erts_print(to, to_arg, "Spawned by: %T\n", p->parent);
 
-    erts_proc_lock(p, ERTS_PROC_LOCK_MSGQ);
-    len = erts_proc_sig_fetch(p);
-    erts_proc_unlock(p, ERTS_PROC_LOCK_MSGQ);
+    if (locks & ERTS_PROC_LOCK_MAIN) {
+        erts_proc_lock(p, ERTS_PROC_LOCK_MSGQ);
+        len = erts_proc_sig_fetch(p);
+        erts_proc_unlock(p, ERTS_PROC_LOCK_MSGQ);
+    } else {
+        len = p->sig_qs.len;
+    }
     erts_print(to, to_arg, "Message queue length: %d\n", len);
 
-    /* display the message queue only if there is anything in it */
-    if (!ERTS_IS_CRASH_DUMPING && p->sig_qs.first != NULL && !garbing) {
+    /* display the message queue only if there is anything in it
+       and we can do it safely */
+    if (!ERTS_IS_CRASH_DUMPING && p->sig_qs.first != NULL && !garbing
+        && (locks & ERTS_PROC_LOCK_MAIN)) {
 	erts_print(to, to_arg, "Message queue: [");
         ERTS_FOREACH_SIG_PRIVQS(
             p, mp,
@@ -306,7 +363,7 @@ print_process_info(fmtfn_t to, void *to_arg, Process *p)
     }
 
     /* display the links only if there are any*/
-    if (ERTS_P_LINKS(p) || ERTS_P_MONITORS(p) || ERTS_P_LT_MONITORS(p)) {
+    if (!exiting && (ERTS_P_LINKS(p) || ERTS_P_MONITORS(p) || ERTS_P_LT_MONITORS(p))) {
 	PrintMonitorContext context = {1, to, to_arg};
 	erts_print(to, to_arg,"Link list: [");
 	erts_link_tree_foreach(ERTS_P_LINKS(p), doit_print_link, &context);	
@@ -338,8 +395,12 @@ print_process_info(fmtfn_t to, void *to_arg, Process *p)
     erts_print(to, to_arg, "OldBinVHeap: %b64u\n", BIN_OLD_VHEAP(p));
     erts_print(to, to_arg, "BinVHeap unused: %b64u\n",
                BIN_VHEAP_SZ(p) - p->off_heap.overhead);
-    erts_print(to, to_arg, "OldBinVHeap unused: %b64u\n",
-               BIN_OLD_VHEAP_SZ(p) - BIN_OLD_VHEAP(p));
+    if (BIN_OLD_VHEAP_SZ(p) >= BIN_OLD_VHEAP(p)) {
+        erts_print(to, to_arg, "OldBinVHeap unused: %b64u\n",
+                   BIN_OLD_VHEAP_SZ(p) - BIN_OLD_VHEAP(p));
+    } else {
+        erts_print(to, to_arg, "OldBinVHeap unused: overflow\n");
+    }
     erts_print(to, to_arg, "Memory: %beu\n", erts_process_memory(p, !0));
 
     if (garbing) {
@@ -357,6 +418,8 @@ print_process_info(fmtfn_t to, void *to_arg, Process *p)
     /* Display all states */
     erts_print(to, to_arg, "Internal State: ");
     erts_dump_extended_process_state(to, to_arg, state);
+
+    erts_proc_unlock(p, locks & ~orig_locks);
 }
 
 static void
diff --git a/erts/emulator/beam/bs_instrs.tab b/erts/emulator/beam/bs_instrs.tab
index 61eb02a7a2..5f25bc2ad3 100644
--- a/erts/emulator/beam/bs_instrs.tab
+++ b/erts/emulator/beam/bs_instrs.tab
@@ -21,12 +21,57 @@
 
 %if ARCH_64
 BS_SAFE_MUL(A, B, Fail, Dst) {
-    Uint64 res = ($A) * ($B);
-    if (res / $B != $A) {
+    Uint a = $A;
+    Uint b = $B;
+    Uint res;
+#ifdef HAVE_OVERFLOW_CHECK_BUILTINS
+    if (__builtin_mul_overflow(a, b, &res)) {
+        $Fail;
+    }
+#else
+    res = a * b;
+    if (res / b != a) {
         $Fail;
     }
+#endif
     $Dst = res;
 }
+
+BS_GET_FIELD_SIZE(Bits, Unit, Fail, Dst) {
+    if (is_small($Bits)) {
+        Uint uint_size;
+        Sint signed_size = signed_val($Bits);
+        if (signed_size < 0) {
+            $Fail;
+        }
+        uint_size = (Uint) signed_size;
+        $BS_SAFE_MUL(uint_size, $Unit, $Fail, $Dst);
+    } else {
+        /*
+         * On a 64-bit architecture, the size of any binary
+         * that would fit in the memory fits in a small.
+         */
+        $Fail;
+    }
+}
+
+BS_GET_UNCHECKED_FIELD_SIZE(Bits, Unit, Fail, Dst) {
+    if (is_small($Bits)) {
+        Uint uint_size;
+        Sint signed_size = signed_val($Bits);
+        if (signed_size < 0) {
+            $Fail;
+        }
+        uint_size = (Uint) signed_size;
+        $Dst = uint_size * $Unit;
+    } else {
+        /*
+         * On a 64-bit architecture, the size of any binary
+         * that would fit in the memory fits in a small.
+         */
+        $Fail;
+    }
+}
 %else
 BS_SAFE_MUL(A, B, Fail, Dst) {
     Uint64 res = (Uint64)($A) * (Uint64)($B);
@@ -35,7 +80,6 @@ BS_SAFE_MUL(A, B, Fail, Dst) {
     }
     $Dst = res;
 }
-%endif
 
 BS_GET_FIELD_SIZE(Bits, Unit, Fail, Dst) {
     Sint signed_size;
@@ -76,11 +120,12 @@ BS_GET_UNCHECKED_FIELD_SIZE(Bits, Unit, Fail, Dst) {
     }
     $Dst = uint_size * $Unit;
 }
+%endif
 
 TEST_BIN_VHEAP(VNh, Nh, Live) {
     Uint need = $Nh;
     if (E - HTOP < need || MSO(c_p).overhead + $VNh >= BIN_VHEAP_SZ(c_p)) {
-        SWAPOUT;
+        $GC_SWAPOUT();
         PROCESS_MAIN_CHK_LOCKS(c_p);
         FCALLS -= erts_garbage_collect_nobump(c_p, need, reg, $Live, FCALLS);
         ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
@@ -90,32 +135,52 @@ TEST_BIN_VHEAP(VNh, Nh, Live) {
     HEAP_SPACE_VERIFIED(need);
 }
 
-i_bs_get_binary_all2(Fail, Ms, Live, Unit, Dst) {
+i_bs_get_binary_all2 := i_bs_get_binary_all2.fetch.execute;
+
+i_bs_get_binary_all2.head() {
+    Eterm context;
+}
+
+i_bs_get_binary_all2.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_binary_all2.execute(Fail, Live, Unit, Dst) {
     ErlBinMatchBuffer *_mb;
     Eterm _result;
 
-    $GC_TEST(0, ERL_SUB_BIN_SIZE, $Live);
-    _mb = ms_matchbuffer($Ms);
+    $GC_TEST_PRESERVE(EXTRACT_SUB_BIN_HEAP_NEED, $Live, context);
+    _mb = ms_matchbuffer(context);
     if (((_mb->size - _mb->offset) % $Unit) == 0) {
         LIGHT_SWAPOUT;
         _result = erts_bs_get_binary_all_2(c_p, _mb);
         LIGHT_SWAPIN;
         HEAP_SPACE_VERIFIED(0);
         ASSERT(is_value(_result));
+        $REFRESH_GEN_DEST();
         $Dst = _result;
     } else {
 	HEAP_SPACE_VERIFIED(0);
 	$FAIL($Fail);
     }
 }
+i_bs_get_binary2 := i_bs_get_binary2.fetch.execute;
+
+i_bs_get_binary2.head() {
+    Eterm context;
+}
 
-i_bs_get_binary2(Fail, Ms, Live, Sz, Flags, Dst) {
+i_bs_get_binary2.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_binary2.execute(Fail, Live, Sz, Flags, Dst) {
     ErlBinMatchBuffer *_mb;
     Eterm _result;
     Uint _size;
     $BS_GET_FIELD_SIZE($Sz, (($Flags) >> 3), $FAIL($Fail), _size);
-    $GC_TEST(0, ERL_SUB_BIN_SIZE, $Live);
-    _mb = ms_matchbuffer($Ms);
+    $GC_TEST_PRESERVE(EXTRACT_SUB_BIN_HEAP_NEED, $Live, context);
+    _mb = ms_matchbuffer(context);
     LIGHT_SWAPOUT;
     _result = erts_bs_get_binary_2(c_p, _size, $Flags, _mb);
     LIGHT_SWAPIN;
@@ -123,15 +188,26 @@ i_bs_get_binary2(Fail, Ms, Live, Sz, Flags, Dst) {
     if (is_non_value(_result)) {
         $FAIL($Fail);
     } else {
+        $REFRESH_GEN_DEST();
         $Dst = _result;
     }
 }
 
-i_bs_get_binary_imm2(Fail, Ms, Live, Sz, Flags, Dst) {
+i_bs_get_binary_imm2 := i_bs_get_binary_imm2.fetch.execute;
+
+i_bs_get_binary_imm2.head() {
+    Eterm context;
+}
+
+i_bs_get_binary_imm2.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_binary_imm2.execute(Fail, Live, Sz, Flags, Dst) {
     ErlBinMatchBuffer *_mb;
     Eterm _result;
-    $GC_TEST(0, heap_bin_size(ERL_ONHEAP_BIN_LIMIT), $Live);
-    _mb = ms_matchbuffer($Ms);
+    $GC_TEST_PRESERVE(EXTRACT_SUB_BIN_HEAP_NEED, $Live, context);
+    _mb = ms_matchbuffer(context);
     LIGHT_SWAPOUT;
     _result = erts_bs_get_binary_2(c_p, $Sz, $Flags, _mb);
     LIGHT_SWAPIN;
@@ -139,11 +215,21 @@ i_bs_get_binary_imm2(Fail, Ms, Live, Sz, Flags, Dst) {
     if (is_non_value(_result)) {
         $FAIL($Fail);
     } else {
+        $REFRESH_GEN_DEST();
         $Dst = _result;
     }
 }
+i_bs_get_float2 := i_bs_get_float2.fetch.execute;
 
-i_bs_get_float2(Fail, Ms, Live, Sz, Flags, Dst) {
+i_bs_get_float2.head() {
+    Eterm context;
+}
+
+i_bs_get_float2.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_float2.execute(Fail, Live, Sz, Flags, Dst) {
     ErlBinMatchBuffer *_mb;
     Eterm _result;
     Sint _size;
@@ -152,8 +238,8 @@ i_bs_get_float2(Fail, Ms, Live, Sz, Flags, Dst) {
         $FAIL($Fail);
     }
     _size *= (($Flags) >> 3);
-    $GC_TEST(0, FLOAT_SIZE_OBJECT, $Live);
-    _mb = ms_matchbuffer($Ms);
+    $GC_TEST_PRESERVE(FLOAT_SIZE_OBJECT, $Live, context);
+    _mb = ms_matchbuffer(context);
     LIGHT_SWAPOUT;
     _result = erts_bs_get_float_2(c_p, _size, ($Flags), _mb);
     LIGHT_SWAPIN;
@@ -161,17 +247,29 @@ i_bs_get_float2(Fail, Ms, Live, Sz, Flags, Dst) {
     if (is_non_value(_result)) {
         $FAIL($Fail);
     } else {
+        $REFRESH_GEN_DEST();
         $Dst = _result;
     }
 }
 
-i_bs_skip_bits2(Fail, Ms, Bits, Unit) {
+i_bs_skip_bits2 := i_bs_skip_bits2.fetch.execute;
+
+i_bs_skip_bits2.head() {
+    Eterm context, bits;
+}
+
+i_bs_skip_bits2.fetch(Ctx, Bits) {
+    context = $Ctx;
+    bits = $Bits;
+}
+
+i_bs_skip_bits2.execute(Fail, Unit) {
     ErlBinMatchBuffer *_mb;
     size_t new_offset;
     Uint _size;
 
-    _mb = ms_matchbuffer($Ms);
-    $BS_GET_FIELD_SIZE($Bits, $Unit, $FAIL($Fail), _size);
+    _mb = ms_matchbuffer(context);
+    $BS_GET_FIELD_SIZE(bits, $Unit, $FAIL($Fail), _size);
     new_offset = _mb->offset + _size;
     if (new_offset <= _mb->size) {
         _mb->offset = new_offset;
@@ -180,16 +278,6 @@ i_bs_skip_bits2(Fail, Ms, Bits, Unit) {
     }
 }
 
-i_bs_skip_bits_all2(Fail, Ms, Unit) {
-    ErlBinMatchBuffer *_mb;
-    _mb = ms_matchbuffer($Ms);
-    if (((_mb->size - _mb->offset) % $Unit) == 0) {
-        _mb->offset = _mb->size;
-    } else {
-        $FAIL($Fail);
-    }
-}
-
 i_bs_skip_bits_imm2(Fail, Ms, Bits) {
     ErlBinMatchBuffer *_mb;
     size_t new_offset;
@@ -203,15 +291,25 @@ i_bs_skip_bits_imm2(Fail, Ms, Bits) {
 }
 
 i_new_bs_put_binary(Fail, Sz, Flags, Src) {
+    Eterm sz = $Sz;
     Sint _size;
-    $BS_GET_UNCHECKED_FIELD_SIZE($Sz, (($Flags) >> 3), $BADARG($Fail), _size);
+    $BS_GET_UNCHECKED_FIELD_SIZE(sz, (($Flags) >> 3), $BADARG($Fail), _size);
     if (!erts_new_bs_put_binary(ERL_BITS_ARGS_2(($Src), _size))) {
         $BADARG($Fail);
     }
 }
+i_new_bs_put_binary_all := i_new_bs_put_binary_all.fetch.execute;
+
+i_new_bs_put_binary_all.head() {
+    Eterm src;
+}
+
+i_new_bs_put_binary_all.fetch(Src) {
+    src = $Src;
+}
 
-i_new_bs_put_binary_all(Fail, Src, Unit) {
-    if (!erts_new_bs_put_binary_all(ERL_BITS_ARGS_2(($Src), ($Unit)))) {
+i_new_bs_put_binary_all.execute(Fail, Unit) {
+    if (!erts_new_bs_put_binary_all(ERL_BITS_ARGS_2(src, ($Unit)))) {
         $BADARG($Fail);
     }
 }
@@ -223,9 +321,11 @@ i_new_bs_put_binary_imm(Fail, Sz, Src) {
 }
 
 i_new_bs_put_float(Fail, Sz, Flags, Src) {
+    Eterm sz = $Sz;
+    Eterm flags = $Flags;
     Sint _size;
-    $BS_GET_UNCHECKED_FIELD_SIZE($Sz, (($Flags) >> 3), $BADARG($Fail), _size);
-    if (!erts_new_bs_put_float(c_p, ($Src), _size, ($Flags))) {
+    $BS_GET_UNCHECKED_FIELD_SIZE(sz, (flags >> 3), $BADARG($Fail), _size);
+    if (!erts_new_bs_put_float(c_p, ($Src), _size, flags)) {
         $BADARG($Fail);
     }
 }
@@ -237,15 +337,27 @@ i_new_bs_put_float_imm(Fail, Sz, Flags, Src) {
 }
 
 i_new_bs_put_integer(Fail, Sz, Flags, Src) {
-   Sint _size;
-   $BS_GET_UNCHECKED_FIELD_SIZE($Sz, (($Flags) >> 3), $BADARG($Fail), _size);
-   if (!erts_new_bs_put_integer(ERL_BITS_ARGS_3(($Src), _size, ($Flags)))) {
-       $BADARG($Fail);
-   }
+    Eterm sz = $Sz;
+    Eterm flags = $Flags;
+    Sint _size;
+    $BS_GET_UNCHECKED_FIELD_SIZE(sz, (flags >> 3), $BADARG($Fail), _size);
+    if (!erts_new_bs_put_integer(ERL_BITS_ARGS_3(($Src), _size, flags))) {
+        $BADARG($Fail);
+    }
+}
+
+i_new_bs_put_integer_imm := i_new_bs_put_integer_imm.fetch.execute;
+
+i_new_bs_put_integer_imm.head() {
+    Eterm src;
+}
+
+i_new_bs_put_integer_imm.fetch(Src) {
+    src = $Src;
 }
 
-i_new_bs_put_integer_imm(Fail, Sz, Flags, Src) {
-    if (!erts_new_bs_put_integer(ERL_BITS_ARGS_3(($Src), ($Sz), ($Flags)))) {
+i_new_bs_put_integer_imm.execute(Fail, Sz, Flags) {
+    if (!erts_new_bs_put_integer(ERL_BITS_ARGS_3(src, ($Sz), ($Flags)))) {
         $BADARG($Fail);
     }
 }
@@ -724,26 +836,34 @@ bs_start_match.execute(Fail, Live, Slots, Dst) {
         $FAIL($Fail);
     }
     header = *boxed_val(context);
-    slots = $Slots;
+
+    /* Reserve a slot for the start position. */
+    slots = $Slots + 1;
     live = $Live;
+
     if (header_is_bin_matchstate(header)) {
         ErlBinMatchState* ms = (ErlBinMatchState *) boxed_val(context);
         Uint actual_slots = HEADER_NUM_SLOTS(header);
+
+        /* We're not compatible with contexts created by bs_start_match3. */
+        ASSERT(actual_slots >= 1);
+
         ms->save_offset[0] = ms->mb.offset;
-        if (actual_slots < slots) {
-            ErlBinMatchState* dst;
+        if (ERTS_UNLIKELY(actual_slots < slots)) {
+            ErlBinMatchState* expanded;
             Uint live = $Live;
             Uint wordsneeded = ERL_BIN_MATCHSTATE_SIZE(slots);
-
             $GC_TEST_PRESERVE(wordsneeded, live, context);
             ms = (ErlBinMatchState *) boxed_val(context);
-            dst = (ErlBinMatchState *) HTOP;
-            *dst = *ms;
+            expanded = (ErlBinMatchState *) HTOP;
+            *expanded = *ms;
             *HTOP = HEADER_BIN_MATCHSTATE(slots);
             HTOP += wordsneeded;
             HEAP_SPACE_VERIFIED(0);
-            $Dst = make_matchstate(dst);
+            context = make_matchstate(expanded);
+            $REFRESH_GEN_DEST();
         }
+        $Dst = context;
     } else if (is_binary_header(header)) {
         Eterm result;
         Uint wordsneeded = ERL_BIN_MATCHSTATE_SIZE(slots);
@@ -755,9 +875,8 @@ bs_start_match.execute(Fail, Live, Slots, Dst) {
         result = erts_bs_start_match_2(c_p, context, slots);
         HTOP = HEAP_TOP(c_p);
         HEAP_SPACE_VERIFIED(0);
-        if (is_non_value(result)) {
-            $FAIL($Fail);
-        }
+
+        $REFRESH_GEN_DEST();
         $Dst = result;
     } else {
         $FAIL($Fail);
@@ -796,9 +915,19 @@ bs_test_unit8(Fail, Ctx) {
     }
 }
 
-i_bs_get_integer_8(Ctx, Fail, Dst) {
+i_bs_get_integer_8 := i_bs_get_integer_8.fetch.execute;
+
+i_bs_get_integer_8.head() {
+    Eterm context;
+}
+
+i_bs_get_integer_8.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_integer_8.execute(Fail, Dst) {
     Eterm _result;
-    ErlBinMatchBuffer* _mb = ms_matchbuffer($Ctx);
+    ErlBinMatchBuffer* _mb = ms_matchbuffer(context);
 
     if (_mb->size - _mb->offset < 8) {
         $FAIL($Fail);
@@ -812,9 +941,19 @@ i_bs_get_integer_8(Ctx, Fail, Dst) {
     $Dst = _result;
 }
 
-i_bs_get_integer_16(Ctx, Fail, Dst) {
+i_bs_get_integer_16 := i_bs_get_integer_16.fetch.execute;
+
+i_bs_get_integer_16.head() {
+    Eterm context;
+}
+
+i_bs_get_integer_16.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_integer_16.execute(Fail, Dst) {
     Eterm _result;
-    ErlBinMatchBuffer* _mb = ms_matchbuffer($Ctx);
+    ErlBinMatchBuffer* _mb = ms_matchbuffer(context);
 
     if (_mb->size - _mb->offset < 16) {
         $FAIL($Fail);
@@ -829,9 +968,19 @@ i_bs_get_integer_16(Ctx, Fail, Dst) {
 }
 
 %if ARCH_64
-i_bs_get_integer_32(Ctx, Fail, Dst) {
+i_bs_get_integer_32 := i_bs_get_integer_32.fetch.execute;
+
+i_bs_get_integer_32.head() {
+    Eterm context;
+}
+
+i_bs_get_integer_32.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_integer_32.execute(Fail, Dst) {
     Uint32 _integer;
-    ErlBinMatchBuffer* _mb = ms_matchbuffer($Ctx);
+    ErlBinMatchBuffer* _mb = ms_matchbuffer(context);
 
     if (_mb->size - _mb->offset < 32) {
         $FAIL($Fail);
@@ -881,15 +1030,23 @@ bs_get_integer.execute(Fail, Flags, Dst) {
     $Dst = result;
 }
 
-i_bs_get_integer(Fail, Live, FlagsAndUnit, Ms, Sz, Dst) {
+i_bs_get_integer := i_bs_get_integer.fetch.execute;
+
+i_bs_get_integer.head() {
+    Eterm context;
+}
+
+i_bs_get_integer.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_integer.execute(Fail, Live, FlagsAndUnit, Sz, Dst) {
     Uint flags;
     Uint size;
-    Eterm ms;
     ErlBinMatchBuffer* mb;
     Eterm result;
 
     flags = $FlagsAndUnit;
-    ms = $Ms;
     $BS_GET_FIELD_SIZE($Sz, (flags >> 3), $FAIL($Fail), size);
     if (size >= SMALL_BITS) {
         Uint wordsneeded;
@@ -900,14 +1057,15 @@ i_bs_get_integer(Fail, Live, FlagsAndUnit, Ms, Sz, Dst) {
          * Remember to re-acquire the matchbuffer after gc.
          */
 
-        mb = ms_matchbuffer(ms);
+        mb = ms_matchbuffer(context);
         if (mb->size - mb->offset < size) {
             $FAIL($Fail);
         }
         wordsneeded = 1+WSIZE(NBYTES((Uint) size));
-        $GC_TEST_PRESERVE(wordsneeded, $Live, ms);
+        $GC_TEST_PRESERVE(wordsneeded, $Live, context);
+        $REFRESH_GEN_DEST();
     }
-    mb = ms_matchbuffer(ms);
+    mb = ms_matchbuffer(context);
     LIGHT_SWAPOUT;
     result = erts_bs_get_integer_2(c_p, size, flags, mb);
     LIGHT_SWAPIN;
@@ -918,9 +1076,19 @@ i_bs_get_integer(Fail, Live, FlagsAndUnit, Ms, Sz, Dst) {
     $Dst = result;
 }
 
-i_bs_get_utf8(Ctx, Fail, Dst) {
+i_bs_get_utf8 := i_bs_get_utf8.fetch.execute;
+
+i_bs_get_utf8.head() {
+    Eterm context;
+}
+
+i_bs_get_utf8.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_utf8.execute(Fail, Dst) {
     Eterm result;
-    ErlBinMatchBuffer* mb = ms_matchbuffer($Ctx);
+    ErlBinMatchBuffer* mb = ms_matchbuffer(context);
 
     if (mb->size - mb->offset < 8) {
         $FAIL($Fail);
@@ -939,21 +1107,32 @@ i_bs_get_utf8(Ctx, Fail, Dst) {
     if (is_non_value(result)) {
         $FAIL($Fail);
     }
+    $REFRESH_GEN_DEST();
     $Dst = result;
 }
 
-i_bs_get_utf16(Ctx, Fail, Flags, Dst) {
-    ErlBinMatchBuffer* mb = ms_matchbuffer($Ctx);
+i_bs_get_utf16 := i_bs_get_utf16.fetch.execute;
+
+i_bs_get_utf16.head() {
+    Eterm context;
+}
+
+i_bs_get_utf16.fetch(Ctx) {
+    context = $Ctx;
+}
+
+i_bs_get_utf16.execute(Fail, Flags, Dst) {
+    ErlBinMatchBuffer* mb = ms_matchbuffer(context);
     Eterm result = erts_bs_get_utf16(mb, $Flags);
 
     if (is_non_value(result)) {
         $FAIL($Fail);
     }
+    $REFRESH_GEN_DEST();
     $Dst = result;
 }
 
 bs_context_to_binary := ctx_to_bin.fetch.execute;
-i_bs_get_binary_all_reuse := ctx_to_bin.fetch_bin.execute;
 
 ctx_to_bin.head() {
     Eterm context;
@@ -976,16 +1155,6 @@ ctx_to_bin.fetch(Src) {
     }
 }
 
-ctx_to_bin.fetch_bin(Src, Fail, Unit) {
-    context = $Src;
-    mb = ms_matchbuffer(context);
-    size = mb->size - mb->offset;
-    if (size % $Unit != 0) {
-        $FAIL($Fail);
-    }
-    offs = mb->offset;
-}
-
 ctx_to_bin.execute() {
     Uint hole_size;
     Uint orig = mb->orig;
@@ -1029,10 +1198,325 @@ i_bs_match_string(Ctx, Fail, Bits, Ptr) {
 
 i_bs_save2(Src, Slot) {
     ErlBinMatchState* _ms = (ErlBinMatchState*) boxed_val((Eterm) $Src);
+    ASSERT(HEADER_NUM_SLOTS(_ms->thing_word) > $Slot);
     _ms->save_offset[$Slot] = _ms->mb.offset;
 }
 
 i_bs_restore2(Src, Slot) {
     ErlBinMatchState* _ms = (ErlBinMatchState*) boxed_val((Eterm) $Src);
+    ASSERT(HEADER_NUM_SLOTS(_ms->thing_word) > $Slot);
     _ms->mb.offset = _ms->save_offset[$Slot];
 }
+
+bs_get_tail := bs_get_tail.fetch.execute;
+
+bs_get_tail.head() {
+    Eterm context;
+}
+
+bs_get_tail.fetch(Src) {
+    context = $Src;
+}
+
+bs_get_tail.execute(Dst, Live) {
+    ErlBinMatchBuffer* mb;
+    Uint size, offs;
+    ErlSubBin* sb;
+
+    ASSERT(header_is_bin_matchstate(*boxed_val(context)));
+
+    $GC_TEST_PRESERVE(ERL_SUB_BIN_SIZE, $Live, context);
+
+    mb = ms_matchbuffer(context);
+
+    offs = mb->offset;
+    size = mb->size - offs;
+
+    sb = (ErlSubBin *) HTOP;
+    HTOP += ERL_SUB_BIN_SIZE;
+
+    sb->thing_word = HEADER_SUB_BIN;
+    sb->size = BYTE_OFFSET(size);
+    sb->bitsize = BIT_OFFSET(size);
+    sb->offs = BYTE_OFFSET(offs);
+    sb->bitoffs = BIT_OFFSET(offs);
+    sb->is_writable = 0;
+    sb->orig = mb->orig;
+
+    $REFRESH_GEN_DEST();
+    $Dst = make_binary(sb);
+}
+
+
+%if ARCH_64
+
+i_bs_start_match3_gp := i_bs_start_match3_gp.fetch.execute;
+
+i_bs_start_match3_gp.head() {
+    Eterm context;
+}
+
+i_bs_start_match3_gp.fetch(Src) {
+    context = $Src;
+}
+
+i_bs_start_match3_gp.execute(Live, Fail, Dst, Pos) {
+    Eterm header;
+    Uint position, live;
+
+    live = $Live;
+
+    if (!is_boxed(context)) {
+        $FAIL($Fail);
+    }
+
+    header = *boxed_val(context);
+
+    if (header_is_bin_matchstate(header)) {
+        ErlBinMatchBuffer *mb;
+
+        ASSERT(HEADER_NUM_SLOTS(header) == 0);
+
+        mb = ms_matchbuffer(context);
+        position = mb->offset;
+
+        $Dst = context;
+    } else if (is_binary_header(header)) {
+        ErlBinMatchState *ms;
+
+        $GC_TEST_PRESERVE(ERL_BIN_MATCHSTATE_SIZE(0), live, context);
+        HEAP_TOP(c_p) = HTOP;
+#ifdef DEBUG
+        c_p->stop = E;	/* Needed for checking in HeapOnlyAlloc(). */
+#endif
+        ms = erts_bs_start_match_3(c_p, context);
+        HTOP = HEAP_TOP(c_p);
+        HEAP_SPACE_VERIFIED(0);
+
+        $REFRESH_GEN_DEST();
+        $Dst = make_matchstate(ms);
+        position = ms->mb.offset;
+    } else {
+        $FAIL($Fail);
+    }
+
+    ASSERT(IS_USMALL(0, position));
+    $Pos = make_small(position);
+}
+
+i_bs_start_match3 := i_bs_start_match3.fetch.execute;
+
+i_bs_start_match3.head() {
+    Eterm context;
+}
+
+i_bs_start_match3.fetch(Src) {
+    context = $Src;
+}
+
+i_bs_start_match3.execute(Live, Fail, Dst) {
+    Eterm header;
+    Uint live;
+
+    live = $Live;
+
+    if (!is_boxed(context)) {
+        $FAIL($Fail);
+    }
+
+    header = *boxed_val(context);
+
+    if (header_is_bin_matchstate(header)) {
+        ASSERT(HEADER_NUM_SLOTS(header) == 0);
+        $Dst = context;
+    } else if (is_binary_header(header)) {
+        ErlBinMatchState *ms;
+
+        $GC_TEST_PRESERVE(ERL_BIN_MATCHSTATE_SIZE(0), live, context);
+        HEAP_TOP(c_p) = HTOP;
+#ifdef DEBUG
+        c_p->stop = E;	/* Needed for checking in HeapOnlyAlloc(). */
+#endif
+        ms = erts_bs_start_match_3(c_p, context);
+        HTOP = HEAP_TOP(c_p);
+        HEAP_SPACE_VERIFIED(0);
+
+        $REFRESH_GEN_DEST();
+        $Dst = make_matchstate(ms);
+    } else {
+        $FAIL($Fail);
+    }
+}
+
+bs_set_position(Ctx, Pos) {
+    ErlBinMatchBuffer* mb;
+    Eterm context;
+
+    context = $Ctx;
+    ASSERT(header_is_bin_matchstate(*boxed_val(context)));
+
+    mb = ms_matchbuffer(context);
+    mb->offset = unsigned_val($Pos);
+}
+
+i_bs_get_position(Ctx, Dst) {
+    ErlBinMatchBuffer* mb;
+    Eterm context;
+
+    context = $Ctx;
+    ASSERT(header_is_bin_matchstate(*boxed_val(context)));
+
+    mb = ms_matchbuffer(context);
+    $Dst = make_small(mb->offset);
+}
+
+%else
+
+#
+# Unlike their 64-bit counterparts, the 32-bit position instructions operate on
+# an offset from the "base position" of the context because storing raw
+# positions would lead to the creation of far too many bigints.
+#
+# When a match context is reused we check whether its position fits into an
+# immediate, and create a new match context if it does not. This means we only
+# have to allocate stuff roughly once every 16MB rather than every time we
+# match at a position beyond 16MB.
+#
+
+bs_set_position := bs_set_position.fetch.execute;
+
+bs_set_position.head() {
+    Eterm context, position;
+}
+
+bs_set_position.fetch(Ctx, Pos) {
+    context = $Ctx;
+    position = $Pos;
+}
+
+bs_set_position.execute() {
+    ErlBinMatchState *ms;
+
+    ASSERT(header_is_bin_matchstate(*boxed_val(context)));
+    ms = (ErlBinMatchState*)boxed_val(context);
+
+    if (ERTS_LIKELY(is_small(position))) {
+        ms->mb.offset = ms->save_offset[0] + unsigned_val(position);
+    } else {
+        ASSERT(is_big(position));
+        ms->mb.offset = ms->save_offset[0] + *BIG_V(big_val(position));
+    }
+}
+
+bs_get_position := bs_get_position.fetch.execute;
+
+bs_get_position.head() {
+    Eterm context;
+}
+
+bs_get_position.fetch(Ctx) {
+    context = $Ctx;
+}
+
+bs_get_position.execute(Dst, Live) {
+    ErlBinMatchState *ms;
+    Uint position;
+
+    ASSERT(header_is_bin_matchstate(*boxed_val(context)));
+    ms = (ErlBinMatchState*)boxed_val(context);
+
+    position = ms->mb.offset - ms->save_offset[0];
+
+    if (ERTS_LIKELY(IS_USMALL(0, position))) {
+        $Dst = make_small(position);
+    } else {
+        Eterm *hp;
+
+        $GC_TEST_PRESERVE(BIG_UINT_HEAP_SIZE, $Live, context);
+
+        hp = HTOP;
+        HTOP += BIG_UINT_HEAP_SIZE;
+
+        *hp = make_pos_bignum_header(1);
+        BIG_DIGIT(hp, 0) = position;
+
+        $REFRESH_GEN_DEST();
+        $Dst = make_big(hp);
+    }
+}
+
+i_bs_start_match3 := i_bs_start_match3.fetch.execute;
+
+i_bs_start_match3.head() {
+    Eterm context;
+}
+
+i_bs_start_match3.fetch(Src) {
+    context = $Src;
+}
+
+i_bs_start_match3.execute(Live, Fail, Dst) {
+    Eterm header;
+    Uint live;
+
+    live = $Live;
+
+    if (!is_boxed(context)) {
+        $FAIL($Fail);
+    }
+
+    header = *boxed_val(context);
+
+    if (header_is_bin_matchstate(header)) {
+        ErlBinMatchState *current_ms;
+        Uint position;
+
+        ASSERT(HEADER_NUM_SLOTS(header) == 1);
+
+        current_ms = (ErlBinMatchState*)boxed_val(context);
+        position = current_ms->mb.offset - current_ms->save_offset[0];
+
+        if (ERTS_LIKELY(IS_USMALL(0, position))) {
+            $Dst = context;
+        } else {
+            ErlBinMatchState *new_ms;
+
+            $GC_TEST_PRESERVE(ERL_BIN_MATCHSTATE_SIZE(1), live, context);
+            current_ms = (ErlBinMatchState*)boxed_val(context);
+
+            new_ms = (ErlBinMatchState*)HTOP;
+            HTOP += ERL_BIN_MATCHSTATE_SIZE(1);
+
+            new_ms->thing_word = HEADER_BIN_MATCHSTATE(1);
+            new_ms->save_offset[0] = current_ms->mb.offset;
+            new_ms->mb = current_ms->mb;
+
+            $REFRESH_GEN_DEST();
+            $Dst = make_matchstate(new_ms);
+        }
+    } else if (is_binary_header(header)) {
+        Eterm result;
+
+        $GC_TEST_PRESERVE(ERL_BIN_MATCHSTATE_SIZE(1), live, context);
+        HEAP_TOP(c_p) = HTOP;
+
+#ifdef DEBUG
+        c_p->stop = E;	/* Needed for checking in HeapOnlyAlloc(). */
+#endif
+
+        /* We intentionally use erts_bs_start_match_2 so that we can use
+         * save_offset as a base for all saved positions on this context,
+         * allowing us to avoid bigints for much longer. */
+        result = erts_bs_start_match_2(c_p, context, 1);
+
+        HTOP = HEAP_TOP(c_p);
+        HEAP_SPACE_VERIFIED(0);
+
+        $REFRESH_GEN_DEST();
+        $Dst = result;
+    } else {
+        $FAIL($Fail);
+    }
+}
+
+%endif
diff --git a/erts/emulator/beam/copy.c b/erts/emulator/beam/copy.c
index e7bd046e18..9bbcba6f3b 100644
--- a/erts/emulator/beam/copy.c
+++ b/erts/emulator/beam/copy.c
@@ -604,7 +604,12 @@ cleanup:
 /*
  *  Copy a structure to a heap.
  */
-Eterm copy_struct_x(Eterm obj, Uint sz, Eterm** hpp, ErlOffHeap* off_heap, Uint *bsz, erts_literal_area_t *litopt)
+Eterm copy_struct_x(Eterm obj, Uint sz, Eterm** hpp, ErlOffHeap* off_heap,
+                    Uint *bsz, erts_literal_area_t *litopt
+#ifdef ERTS_COPY_REGISTER_LOCATION
+                    , char *file, int line
+#endif
+    )
 {
     char* hstart;
     Uint hsize;
@@ -854,7 +859,11 @@ Eterm copy_struct_x(Eterm obj, Uint sz, Eterm** hpp, ErlOffHeap* off_heap, Uint
 	    case EXTERNAL_REF_SUBTAG:
 		{
 		  ExternalThing *etp = (ExternalThing *) objp;
-		  erts_refc_inc(&etp->node->refc, 2);
+#if defined(ERTS_COPY_REGISTER_LOCATION) && defined(ERL_NODE_BOOKKEEP)
+		  erts_ref_node_entry__(etp->node, 2, make_boxed(htop), file, line);
+#else
+		  erts_ref_node_entry(etp->node, 2, make_boxed(htop));
+#endif
 		}
 	    L_off_heap_node_container_common:
 		{
@@ -1326,8 +1335,13 @@ Uint copy_shared_calculate(Eterm obj, erts_shcopy_t *info)
  *  Copy object "obj" preserving sharing.
  *  Second half: copy and restore the object.
  */
-Uint copy_shared_perform(Eterm obj, Uint size, erts_shcopy_t *info,
-                         Eterm** hpp, ErlOffHeap* off_heap) {
+Uint copy_shared_perform_x(Eterm obj, Uint size, erts_shcopy_t *info,
+                           Eterm** hpp, ErlOffHeap* off_heap
+#ifdef ERTS_COPY_REGISTER_LOCATION
+                           , char *file, int line
+#endif
+    )
+{
     Uint e;
     unsigned sz;
     Eterm* ptr;
@@ -1393,7 +1407,11 @@ Uint copy_shared_perform(Eterm obj, Uint size, erts_shcopy_t *info,
                     *resp = obj;
                 } else {
                     Uint bsz = 0;
-                    *resp = copy_struct_x(obj, hbot - hp, &hp, off_heap, &bsz, NULL); /* copy literal */
+                    *resp = copy_struct_x(obj, hbot - hp, &hp, off_heap, &bsz, NULL
+#ifdef ERTS_COPY_REGISTER_LOCATION
+                                          , file, line
+#endif
+                        ); /* copy literal */
                     hbot -= bsz;
                 }
 		goto cleanup_next;
@@ -1461,7 +1479,11 @@ Uint copy_shared_perform(Eterm obj, Uint size, erts_shcopy_t *info,
                     *resp = obj;
                 } else {
                     Uint bsz = 0;
-                    *resp = copy_struct_x(obj, hbot - hp, &hp, off_heap, &bsz, NULL); /* copy literal */
+                    *resp = copy_struct_x(obj, hbot - hp, &hp, off_heap, &bsz, NULL
+#ifdef ERTS_COPY_REGISTER_LOCATION
+                                          , file, line
+#endif
+                        ); /* copy literal */
                     hbot -= bsz;
                 }
 		goto cleanup_next;
@@ -1660,7 +1682,12 @@ Uint copy_shared_perform(Eterm obj, Uint size, erts_shcopy_t *info,
 	    case EXTERNAL_REF_SUBTAG:
 	    {
 		ExternalThing *etp = (ExternalThing *) ptr;
-		erts_refc_inc(&etp->node->refc, 2);
+                
+#if defined(ERTS_COPY_REGISTER_LOCATION) && defined(ERL_NODE_BOOKKEEP)
+                erts_ref_node_entry__(etp->node, 2, make_boxed(hp), file, line);
+#else
+                erts_ref_node_entry(etp->node, 2, make_boxed(hp));
+#endif
 	    }
 	  off_heap_node_container_common:
 	    {
@@ -1823,8 +1850,12 @@ all_clean:
  *
  * NOTE: Assumes that term is a tuple (ptr is an untagged tuple ptr).
  */
-Eterm copy_shallow(Eterm* ERTS_RESTRICT ptr, Uint sz, Eterm** hpp,
-                   ErlOffHeap* off_heap)
+Eterm
+copy_shallow_x(Eterm* ERTS_RESTRICT ptr, Uint sz, Eterm** hpp, ErlOffHeap* off_heap
+#ifdef ERTS_COPY_REGISTER_LOCATION
+               , char *file, int line
+#endif
+    )
 {
     Eterm* tp = ptr;
     Eterm* hp = *hpp;
@@ -1866,7 +1897,11 @@ Eterm copy_shallow(Eterm* ERTS_RESTRICT ptr, Uint sz, Eterm** hpp,
 	    case EXTERNAL_REF_SUBTAG:
 		{
 		    ExternalThing* etp = (ExternalThing *) (tp-1);
-		    erts_refc_inc(&etp->node->refc, 2);
+#if defined(ERTS_COPY_REGISTER_LOCATION) && defined(ERL_NODE_BOOKKEEP)
+                    erts_ref_node_entry__(etp->node, 2, make_boxed(hp-1), file, line);
+#else
+                    erts_ref_node_entry(etp->node, 2, make_boxed(hp-1));
+#endif
 		}
 	    off_heap_common:
 		{
diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index 0633bff3c2..eb9e749a08 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -50,19 +50,26 @@
 #define DIST_CTL_DEFAULT_SIZE 64
 
 /* Turn this on to get printouts of all distribution messages
- * which go on the line
+ * which go on the line. Enabling this may make some testcases
+ * fail. Especially the broken dist testcases in distribution_SUITE.
  */
 #if 0
 #define ERTS_DIST_MSG_DBG
 #endif
 #if 0
+/* Enable this to print the dist debug messages to a file instead */
+#define ERTS_DIST_MSG_DBG_FILE "/tmp/dist_dbg.%d"
+#endif
+#if 0
+/* Enable this to print the raw bytes sent and received */
 #define ERTS_RAW_DIST_MSG_DBG
 #endif
 
 #if defined(ERTS_DIST_MSG_DBG) || defined(ERTS_RAW_DIST_MSG_DBG)
+FILE *dbg_file;
 static void bw(byte *buf, ErlDrvSizeT sz)
 {
-    bin_write(ERTS_PRINT_STDERR, NULL, buf, sz);
+    bin_write(ERTS_PRINT_FILE, dbg_file, buf, sz);
 }
 #endif
 
@@ -70,39 +77,93 @@ static void bw(byte *buf, ErlDrvSizeT sz)
 static void
 dist_msg_dbg(ErtsDistExternal *edep, char *what, byte *buf, int sz)
 {
-    ErtsHeapFactory factory;
-    DeclareTmpHeapNoproc(ctl_default,DIST_CTL_DEFAULT_SIZE);
-    Eterm* ctl = ctl_default;
-    byte *extp = edep->extp;
+    byte *extp = edep->data->extp;
     Eterm msg;
     Sint ctl_len;
-    Sint size = ctl_len = erts_decode_dist_ext_size(edep);
+    Sint size = ctl_len = erts_decode_dist_ext_size(edep, 0, 0);
     if (size < 0) {
-	erts_fprintf(stderr,
+	erts_fprintf(dbg_file,
 		     "DIST MSG DEBUG: erts_decode_dist_ext_size(%s) failed:\n",
 		     what);
 	bw(buf, sz);
     }
     else {
-	ErlHeapFragment *mbuf = new_message_buffer(size);
-	erts_factory_static_init(&factory, ctl, ctl_len, &mbuf->off_heap);
-	msg = erts_decode_dist_ext(&factory, edep);
+        ErtsHeapFactory factory;
+	ErtsMessage *mbuf = erts_factory_message_create(&factory, NULL, 0, ctl_len);
+        /* Set mbuf msg to NIL as erts_factory_undo will fail otherwise */
+        ERL_MESSAGE_TERM(mbuf) = NIL;
+        msg = erts_decode_dist_ext(&factory, edep, 0);
 	if (is_value(msg))
-	    erts_fprintf(stderr, "    %s: %T\n", what, msg);
+	    erts_fprintf(dbg_file, "    %s: %.80T\n", what, msg);
 	else {
-	    erts_fprintf(stderr,
+	    erts_fprintf(dbg_file,
 			 "DIST MSG DEBUG: erts_decode_dist_ext(%s) failed:\n",
 			 what);
 	    bw(buf, sz);
 	}
-	free_message_buffer(mbuf);
-	edep->extp = extp;
+        erts_factory_undo(&factory);
+	edep->data->extp = extp;
     }
 }
 
+static char *erts_dop_to_string(enum dop dop) {
+    if (dop == DOP_LINK)
+        return "LINK";
+    if (dop == DOP_SEND)
+        return "SEND";
+    if (dop == DOP_EXIT)
+        return "EXIT";
+    if (dop == DOP_UNLINK)
+        return "UNLINK";
+    if (dop == DOP_REG_SEND)
+        return "REG_SEND";
+    if (dop == DOP_GROUP_LEADER)
+        return "GROUP_LEADER";
+    if (dop == DOP_EXIT2)
+        return "EXIT2";
+    if (dop == DOP_SEND_TT)
+        return "SEND_TT";
+    if (dop == DOP_EXIT_TT)
+        return "EXIT_TT";
+    if (dop == DOP_REG_SEND_TT)
+        return "REG_SEND_TT";
+    if (dop == DOP_EXIT2_TT)
+        return "EXIT2_TT";
+    if (dop == DOP_MONITOR_P)
+        return "MONITOR_P";
+    if (dop == DOP_DEMONITOR_P)
+        return "DEMONITOR_P";
+    if (dop == DOP_MONITOR_P_EXIT)
+        return "MONITOR_P_EXIT";
+    if (dop == DOP_SEND_SENDER)
+        return "SEND_SENDER";
+    if (dop == DOP_SEND_SENDER_TT)
+        return "SEND_SENDER_TT";
+    if (dop == DOP_PAYLOAD_EXIT)
+        return "PAYLOAD_EXIT";
+    if (dop == DOP_PAYLOAD_EXIT_TT)
+        return "PAYLOAD_EXIT_TT";
+    if (dop == DOP_PAYLOAD_EXIT2)
+        return "PAYLOAD_EXIT2";
+    if (dop == DOP_PAYLOAD_EXIT2_TT)
+        return "PAYLOAD_EXIT2_TT";
+    if (dop == DOP_PAYLOAD_MONITOR_P_EXIT)
+        return "PAYLOAD_MONITOR_P_EXIT";
+    ASSERT(0);
+    return "UNKNOWN";
+}
+
 #endif
 
+#if defined(VALGRIND)
+#include <valgrind/valgrind.h>
+#include <valgrind/memcheck.h>
 
+#  define PURIFY_MSG(msg)                                                    \
+    VALGRIND_PRINTF("%s, line %d: %s", __FILE__, __LINE__, msg)
+#else
+#  define PURIFY_MSG(msg)
+#endif
 
 int erts_is_alive; /* System must be blocked on change */
 int erts_dist_buf_busy_limit;
@@ -116,12 +177,17 @@ static Export *dist_ctrl_put_data_trap;
 
 /* forward declarations */
 
-static int dsig_send_ctl(ErtsDSigData* dsdp, Eterm ctl, int force_busy);
+static void erts_schedule_dist_command(Port *, DistEntry *);
+static int dsig_send_exit(ErtsDSigSendContext *ctx, Eterm ctl, Eterm msg);
+static int dsig_send_ctl(ErtsDSigSendContext *ctx, Eterm ctl);
 static void send_nodes_mon_msgs(Process *, Eterm, Eterm, Eterm, Eterm);
 static void init_nodes_monitors(void);
 static Sint abort_connection(DistEntry* dep, Uint32 conn_id);
 static ErtsDistOutputBuf* clear_de_out_queues(DistEntry*);
 static void free_de_out_queues(DistEntry*, ErtsDistOutputBuf*);
+int erts_dist_seq_tree_foreach_delete_yielding(DistSeqNode **root,
+                                               void **vyspp,
+                                               Sint limit);
 
 static erts_atomic_t no_caches;
 static erts_atomic_t no_nodes;
@@ -142,7 +208,6 @@ delete_cache(ErtsAtomCache *cache)
     }
 }
 
-
 static void
 create_cache(DistEntry *dep)
 {
@@ -185,32 +250,36 @@ get_suspended_on_de(DistEntry *dep, erts_aint32_t unset_qflgs)
     }
 }
 
-#define ERTS_MON_LNK_FIRE_LIMIT 100
+#define ERTS_MON_LNK_FIRE_REDS 40
 
-static void monitor_connection_down(ErtsMonitor *mon, void *unused)
+static int monitor_connection_down(ErtsMonitor *mon, void *unused, Sint reds)
 {
     if (erts_monitor_is_origin(mon))
         erts_proc_sig_send_demonitor(mon);
     else
         erts_proc_sig_send_monitor_down(mon, am_noconnection);
+    return ERTS_MON_LNK_FIRE_REDS;
 }
 
-static void link_connection_down(ErtsLink *lnk, void *vdist)
+static int link_connection_down(ErtsLink *lnk, void *vdist, Sint reds)
 {
     erts_proc_sig_send_link_exit(NULL, THE_NON_VALUE, lnk,
                                  am_noconnection, NIL);
+    return ERTS_MON_LNK_FIRE_REDS;
 }
 
 typedef enum {
     ERTS_CML_CLEANUP_STATE_LINKS,
     ERTS_CML_CLEANUP_STATE_MONITORS,
     ERTS_CML_CLEANUP_STATE_ONAME_MONITORS,
+    ERTS_CML_CLEANUP_STATE_SEQUENCES,
     ERTS_CML_CLEANUP_STATE_NODE_MONITORS
-} ErtsConMonLnkCleaupState;
+} ErtsConMonLnkSeqCleanupState;
 
 typedef struct {
-    ErtsConMonLnkCleaupState state;
+    ErtsConMonLnkSeqCleanupState state;
     ErtsMonLnkDist *dist;
+    DistSeqNode *seq;
     void *yield_state;
     int trigger_node_monitors;
     Eterm nodename;
@@ -218,49 +287,58 @@ typedef struct {
     Eterm reason;
     ErlOffHeap oh;
     Eterm heap[1];
-} ErtsConMonLnkCleanup;
+} ErtsConMonLnkSeqCleanup;
 
 static void
-con_monitor_link_cleanup(void *vcmlcp)
+con_monitor_link_seq_cleanup(void *vcmlcp)
 {
-    ErtsConMonLnkCleanup *cmlcp = vcmlcp;
+    ErtsConMonLnkSeqCleanup *cmlcp = vcmlcp;
     ErtsMonLnkDist *dist = cmlcp->dist;
     ErtsSchedulerData *esdp;
-    int yield;
+    int reds = CONTEXT_REDS;
 
     switch (cmlcp->state) {
     case ERTS_CML_CLEANUP_STATE_LINKS:
-        yield = erts_link_list_foreach_delete_yielding(&dist->links,
-                                                       link_connection_down,
-                                                       NULL, &cmlcp->yield_state,
-                                                       ERTS_MON_LNK_FIRE_LIMIT);
-        if (yield)
+        reds = erts_link_list_foreach_delete_yielding(&dist->links,
+                                                      link_connection_down,
+                                                      NULL, &cmlcp->yield_state,
+                                                      reds);
+        if (reds <= 0)
             break;
 
         ASSERT(!cmlcp->yield_state);
         cmlcp->state = ERTS_CML_CLEANUP_STATE_MONITORS;
     case ERTS_CML_CLEANUP_STATE_MONITORS:
-        yield = erts_monitor_list_foreach_delete_yielding(&dist->monitors,
-                                                          monitor_connection_down,
-                                                          NULL, &cmlcp->yield_state,
-                                                          ERTS_MON_LNK_FIRE_LIMIT);
-        if (yield)
+        reds = erts_monitor_list_foreach_delete_yielding(&dist->monitors,
+                                                         monitor_connection_down,
+                                                         NULL, &cmlcp->yield_state,
+                                                         reds);
+        if (reds <= 0)
             break;
 
         ASSERT(!cmlcp->yield_state);
         cmlcp->state = ERTS_CML_CLEANUP_STATE_ONAME_MONITORS;
     case ERTS_CML_CLEANUP_STATE_ONAME_MONITORS:
-        yield = erts_monitor_tree_foreach_delete_yielding(&dist->orig_name_monitors,
-                                                          monitor_connection_down,
-                                                          NULL, &cmlcp->yield_state,
-                                                          ERTS_MON_LNK_FIRE_LIMIT/2);
-        if (yield)
+        reds = erts_monitor_tree_foreach_delete_yielding(&dist->orig_name_monitors,
+                                                         monitor_connection_down,
+                                                         NULL, &cmlcp->yield_state,
+                                                         reds);
+        if (reds <= 0)
             break;
 
         cmlcp->dist = NULL;
         erts_mon_link_dist_dec_refc(dist);
 
         ASSERT(!cmlcp->yield_state);
+        cmlcp->state = ERTS_CML_CLEANUP_STATE_SEQUENCES;
+    case ERTS_CML_CLEANUP_STATE_SEQUENCES:
+        reds = erts_dist_seq_tree_foreach_delete_yielding(&cmlcp->seq,
+                                                          &cmlcp->yield_state,
+                                                          reds);
+        if (reds <= 0)
+            break;
+
+        ASSERT(!cmlcp->yield_state);
         cmlcp->state = ERTS_CML_CLEANUP_STATE_NODE_MONITORS;
     case ERTS_CML_CLEANUP_STATE_NODE_MONITORS:
         if (cmlcp->trigger_node_monitors) {
@@ -280,22 +358,23 @@ con_monitor_link_cleanup(void *vcmlcp)
     esdp = erts_get_scheduler_data();
     ASSERT(esdp && esdp->type == ERTS_SCHED_NORMAL);
     erts_schedule_misc_aux_work((int) esdp->no,
-                                con_monitor_link_cleanup,
+                                con_monitor_link_seq_cleanup,
                                 (void *) cmlcp);
 }
 
 static void
-schedule_con_monitor_link_cleanup(ErtsMonLnkDist *dist,
-                                  Eterm nodename,
-                                  Eterm visability,
-                                  Eterm reason)
+schedule_con_monitor_link_seq_cleanup(ErtsMonLnkDist *dist,
+                                      DistSeqNode *seq,
+                                      Eterm nodename,
+                                      Eterm visability,
+                                      Eterm reason)
 {
-    if (dist || is_value(nodename)) {
+    if (dist || is_value(nodename) || seq) {
         ErtsSchedulerData *esdp;
-        ErtsConMonLnkCleanup *cmlcp;
+        ErtsConMonLnkSeqCleanup *cmlcp;
         Uint rsz, size;
 
-        size = sizeof(ErtsConMonLnkCleanup);
+        size = sizeof(ErtsConMonLnkSeqCleanup);
 
         if (is_non_value(reason) || is_immed(reason)) {
             rsz = 0;
@@ -322,6 +401,8 @@ schedule_con_monitor_link_cleanup(ErtsMonLnkDist *dist,
             erts_mtx_unlock(&dist->mtx);
         }
 
+        cmlcp->seq = seq;
+
         cmlcp->trigger_node_monitors = is_value(nodename);
         cmlcp->nodename = nodename;
         cmlcp->visability = visability;
@@ -335,13 +416,13 @@ schedule_con_monitor_link_cleanup(ErtsMonLnkDist *dist,
         esdp = erts_get_scheduler_data();
         ASSERT(esdp && esdp->type == ERTS_SCHED_NORMAL);
         erts_schedule_misc_aux_work((int) esdp->no,
-                                    con_monitor_link_cleanup,
+                                    con_monitor_link_seq_cleanup,
                                     (void *) cmlcp);
     }
 }
 
 /*
-** A full node name constists of a "n@h"
+** A full node name consists of a "n@h"
 **
 ** n must be a valid node name: string of ([a-z][A-Z][0-9]_-)+
 ** 
@@ -558,6 +639,7 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
     }
     else { /* Call from distribution controller (port/process) */
         ErtsMonLnkDist *mld;
+        DistSeqNode *sequences;
         ErtsAtomCache *cache;
         ErtsProcList *suspendees;
         ErtsDistOutputBuf *obuf;
@@ -574,9 +656,7 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
         }
 
 	if (dep->state == ERTS_DE_STATE_EXITING) {
-#ifdef DEBUG
 	    ASSERT(erts_atomic32_read_nob(&dep->qflgs) & ERTS_DE_QFLG_EXIT);
-#endif
 	}
 	else {
 	    dep->state = ERTS_DE_STATE_EXITING;
@@ -589,6 +669,9 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
         mld = dep->mld;
         dep->mld = NULL;
 
+        sequences = dep->sequences;
+        dep->sequences = NULL;
+
 	nodename = dep->sysname;
 	flags = dep->flags;
 
@@ -612,14 +695,15 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
 
 	erts_de_rwunlock(dep);
 
-        schedule_con_monitor_link_cleanup(mld,
-                                          nodename,
-                                          (flags & DFLAG_PUBLISHED
-                                           ? am_visible
-                                           : am_hidden),
-                                          (reason == am_normal
-                                           ? am_connection_closed
-                                           : reason));
+        schedule_con_monitor_link_seq_cleanup(mld,
+                                              sequences,
+                                              nodename,
+                                              (flags & DFLAG_PUBLISHED
+                                               ? am_visible
+                                               : am_hidden),
+                                              (reason == am_normal
+                                               ? am_connection_closed
+                                               : reason));
 
         erts_resume_processes(suspendees);
 
@@ -653,6 +737,16 @@ void init_dist(void)
 {
     init_nodes_monitors();
 
+#ifdef ERTS_DIST_MSG_DBG_FILE
+    {
+        char buff[255];
+        sprintf(buff, ERTS_DIST_MSG_DBG_FILE, getpid());
+        dbg_file = fopen(buff,"w+");
+    }
+#elif defined(ERTS_DIST_MSG_DBG) || defined(ERTS_RAW_DIST_MSG_DBG)
+    dbg_file = stderr;
+#endif
+
     nodedown.reason = NIL;
     nodedown.bp = NULL;
 
@@ -676,21 +770,33 @@ void init_dist(void)
     }
 }
 
-#define ErtsDistOutputBuf2Binary(OB) \
-  ((Binary *) (((char *) (OB)) - offsetof(Binary, orig_bytes)))
+#define ErtsDistOutputBuf2Binary(OB) OB->bin
 
 static ERTS_INLINE ErtsDistOutputBuf *
-alloc_dist_obuf(Uint size)
+alloc_dist_obuf(Uint size, Uint headers)
 {
+    Uint obuf_size = sizeof(ErtsDistOutputBuf)*(headers);
     ErtsDistOutputBuf *obuf;
-    Uint obuf_size = sizeof(ErtsDistOutputBuf)+sizeof(byte)*(size-1);
-    Binary *bin = erts_bin_drv_alloc(obuf_size);
-    obuf = (ErtsDistOutputBuf *) &bin->orig_bytes[0];
+    Binary *bin;
+    byte *extp;
+    int i;
+
+    bin = erts_bin_drv_alloc(obuf_size + size);
+    erts_refc_add(&bin->intern.refc, headers - 1, 1);
+
+    obuf = (ErtsDistOutputBuf *)&bin->orig_bytes[0];
+    extp = (byte *)&bin->orig_bytes[obuf_size];
+
+    for (i = 0; i < headers; i++) {
+        obuf[i].bin = bin;
+        obuf[i].extp = extp;
 #ifdef DEBUG
-    obuf->dbg_pattern = ERTS_DIST_OUTPUT_BUF_DBG_PATTERN;
-    obuf->alloc_endp = obuf->data + size;
-    ASSERT(bin == ErtsDistOutputBuf2Binary(obuf));
+        obuf[i].dbg_pattern = ERTS_DIST_OUTPUT_BUF_DBG_PATTERN;
+        obuf[i].ext_startp = extp;
+        obuf[i].alloc_endp = &extp[size];
+        ASSERT(bin == ErtsDistOutputBuf2Binary(obuf));
 #endif
+    }
     return obuf;
 }
 
@@ -705,8 +811,8 @@ free_dist_obuf(ErtsDistOutputBuf *obuf)
 static ERTS_INLINE Sint
 size_obuf(ErtsDistOutputBuf *obuf)
 {
-    Binary *bin = ErtsDistOutputBuf2Binary(obuf);
-    return bin->orig_size;
+    return sizeof(ErtsDistOutputBuf) + (obuf->ext_endp - obuf->ext_start)
+        + (obuf->hdr_endp - obuf->hdrp);
 }
 
 static ErtsDistOutputBuf* clear_de_out_queues(DistEntry* dep)
@@ -760,18 +866,20 @@ static void free_de_out_queues(DistEntry* dep, ErtsDistOutputBuf *obuf)
 
 int erts_dsend_context_dtor(Binary* ctx_bin)
 {
-    ErtsSendContext* ctx = ERTS_MAGIC_BIN_DATA(ctx_bin);
-    switch (ctx->dss.phase) {
+    ErtsDSigSendContext* ctx = ERTS_MAGIC_BIN_DATA(ctx_bin);
+    switch (ctx->phase) {
     case ERTS_DSIG_SEND_PHASE_MSG_SIZE:
-	DESTROY_SAVED_WSTACK(&ctx->dss.u.sc.wstack);
+	DESTROY_SAVED_WSTACK(&ctx->u.sc.wstack);
 	break;
     case ERTS_DSIG_SEND_PHASE_MSG_ENCODE:
-	DESTROY_SAVED_WSTACK(&ctx->dss.u.ec.wstack);
+	DESTROY_SAVED_WSTACK(&ctx->u.ec.wstack);
 	break;
     default:;
     }
-    if (ctx->dss.phase >= ERTS_DSIG_SEND_PHASE_ALLOC && ctx->dss.obuf) {
-	free_dist_obuf(ctx->dss.obuf);
+    if (ctx->phase >= ERTS_DSIG_SEND_PHASE_ALLOC && ctx->obuf) {
+        int i;
+        for (i = 0; i < ctx->fragments; i++)
+            free_dist_obuf(&ctx->obuf[i]);
     }
     if (ctx->deref_dep)
 	erts_deref_dist_entry(ctx->dep);
@@ -779,10 +887,10 @@ int erts_dsend_context_dtor(Binary* ctx_bin)
     return 1;
 }
 
-Eterm erts_dsend_export_trap_context(Process* p, ErtsSendContext* ctx)
+Eterm erts_dsend_export_trap_context(Process* p, ErtsDSigSendContext* ctx)
 {
     struct exported_ctx {
-	ErtsSendContext ctx;
+	ErtsDSigSendContext ctx;
 	ErtsAtomCacheMap acm;
     };
     Binary* ctx_bin = erts_create_magic_binary(sizeof(struct exported_ctx),
@@ -790,12 +898,12 @@ Eterm erts_dsend_export_trap_context(Process* p, ErtsSendContext* ctx)
     struct exported_ctx* dst = ERTS_MAGIC_BIN_DATA(ctx_bin);
     Eterm* hp = HAlloc(p, ERTS_MAGIC_REF_THING_SIZE);
 
-    sys_memcpy(&dst->ctx, ctx, sizeof(ErtsSendContext));
-    ASSERT(ctx->dss.ctl == make_tuple(ctx->ctl_heap));
-    dst->ctx.dss.ctl = make_tuple(dst->ctx.ctl_heap);
-    if (ctx->dss.acmp) {
-	sys_memcpy(&dst->acm, ctx->dss.acmp, sizeof(ErtsAtomCacheMap));
-	dst->ctx.dss.acmp = &dst->acm;
+    sys_memcpy(&dst->ctx, ctx, sizeof(ErtsDSigSendContext));
+    ASSERT(ctx->ctl == make_tuple(ctx->ctl_heap));
+    dst->ctx.ctl = make_tuple(dst->ctx.ctl_heap);
+    if (ctx->acmp) {
+	sys_memcpy(&dst->acm, ctx->acmp, sizeof(ErtsAtomCacheMap));
+	dst->ctx.acmp = &dst->acm;
     }
     return erts_mk_magic_ref(&hp, &MSO(p), ctx_bin);
 }
@@ -816,71 +924,58 @@ Eterm erts_dsend_export_trap_context(Process* p, ErtsSendContext* ctx)
 ** Send a DOP_LINK link message
 */
 int
-erts_dsig_send_link(ErtsDSigData *dsdp, Eterm local, Eterm remote)
+erts_dsig_send_link(ErtsDSigSendContext *ctx, Eterm local, Eterm remote)
 {
-    DeclareTmpHeapNoproc(ctl_heap,4);
-    Eterm ctl = TUPLE3(&ctl_heap[0], make_small(DOP_LINK), local, remote);
-    int res;
-    UseTmpHeapNoproc(4);
-
-    res = dsig_send_ctl(dsdp, ctl, 0);
-    UnUseTmpHeapNoproc(4);
-    return res;
+    Eterm ctl = TUPLE3(&ctx->ctl_heap[0], make_small(DOP_LINK), local, remote);
+    return dsig_send_ctl(ctx, ctl);
 }
 
 int
-erts_dsig_send_unlink(ErtsDSigData *dsdp, Eterm local, Eterm remote)
+erts_dsig_send_unlink(ErtsDSigSendContext *ctx, Eterm local, Eterm remote)
 {
-    DeclareTmpHeapNoproc(ctl_heap,4);
-    Eterm ctl = TUPLE3(&ctl_heap[0], make_small(DOP_UNLINK), local, remote);
-    int res;
-
-    UseTmpHeapNoproc(4);
-    res = dsig_send_ctl(dsdp, ctl, 0);
-    UnUseTmpHeapNoproc(4);
-    return res;
+    Eterm ctl = TUPLE3(&ctx->ctl_heap[0], make_small(DOP_UNLINK), local, remote);
+    return dsig_send_ctl(ctx, ctl);
 }
 
 
 /* A local process that's being monitored by a remote one exits. We send:
    {DOP_MONITOR_P_EXIT, Local pid or name, Remote pid, ref, reason} */
 int
-erts_dsig_send_m_exit(ErtsDSigData *dsdp, Eterm watcher, Eterm watched, 
-			  Eterm ref, Eterm reason)
+erts_dsig_send_m_exit(ErtsDSigSendContext *ctx, Eterm watcher, Eterm watched,
+                      Eterm ref, Eterm reason)
 {
-    Eterm ctl;
-    DeclareTmpHeapNoproc(ctl_heap,6);
-    int res;
+    Eterm ctl, msg;
 
-    if (~dsdp->flags & (DFLAG_DIST_MONITOR | DFLAG_DIST_MONITOR_NAME)) {
+    if (~ctx->flags & (DFLAG_DIST_MONITOR | DFLAG_DIST_MONITOR_NAME)) {
         /*
          * Receiver does not support DOP_MONITOR_P_EXIT (see dsig_send_monitor)
          */
         return ERTS_DSIG_SEND_OK;
     }
 
-    UseTmpHeapNoproc(6);
-
-    ctl = TUPLE5(&ctl_heap[0], make_small(DOP_MONITOR_P_EXIT),
-		 watched, watcher, ref, reason);
+    if (ctx->dep->flags & DFLAG_EXIT_PAYLOAD) {
+        ctl = TUPLE4(&ctx->ctl_heap[0], make_small(DOP_PAYLOAD_MONITOR_P_EXIT),
+                     watched, watcher, ref);
+        msg = reason;
+    } else {
+        ctl = TUPLE5(&ctx->ctl_heap[0], make_small(DOP_MONITOR_P_EXIT),
+                     watched, watcher, ref, reason);
+        msg = THE_NON_VALUE;
+    }
 
-    res = dsig_send_ctl(dsdp, ctl, 1);
-    UnUseTmpHeapNoproc(6);
-    return res;
+    return dsig_send_exit(ctx, ctl, msg);
 }
 
 /* We want to monitor a process (named or unnamed) on another node, we send:
    {DOP_MONITOR_P, Local pid, Remote pid or name, Ref}, which is exactly what's
    needed on the other side... */
 int
-erts_dsig_send_monitor(ErtsDSigData *dsdp, Eterm watcher, Eterm watched,
+erts_dsig_send_monitor(ErtsDSigSendContext *ctx, Eterm watcher, Eterm watched,
 		       Eterm ref)
 {
     Eterm ctl;
-    DeclareTmpHeapNoproc(ctl_heap,5);
-    int res;
 
-    if (~dsdp->flags & (DFLAG_DIST_MONITOR | DFLAG_DIST_MONITOR_NAME)) {
+    if (~ctx->flags & (DFLAG_DIST_MONITOR | DFLAG_DIST_MONITOR_NAME)) {
         /*
          * Receiver does not support DOP_MONITOR_P.
          * Just avoid sending it and by doing that reduce this monitor
@@ -890,48 +985,40 @@ erts_dsig_send_monitor(ErtsDSigData *dsdp, Eterm watcher, Eterm watched,
         return ERTS_DSIG_SEND_OK;
     }
 
-    UseTmpHeapNoproc(5);
-    ctl = TUPLE4(&ctl_heap[0],
+    ctl = TUPLE4(&ctx->ctl_heap[0],
 		 make_small(DOP_MONITOR_P),
 		 watcher, watched, ref);
 
-    res = dsig_send_ctl(dsdp, ctl, 0);
-    UnUseTmpHeapNoproc(5);
-    return res;
+    return dsig_send_ctl(ctx, ctl);
 }
 
 /* A local process monitoring a remote one wants to stop monitoring, either 
    because of a demonitor bif call or because the local process died. We send
    {DOP_DEMONITOR_P, Local pid, Remote pid or name, ref} */
 int
-erts_dsig_send_demonitor(ErtsDSigData *dsdp, Eterm watcher,
-			 Eterm watched, Eterm ref, int force)
+erts_dsig_send_demonitor(ErtsDSigSendContext *ctx, Eterm watcher,
+			 Eterm watched, Eterm ref)
 {
     Eterm ctl;
-    DeclareTmpHeapNoproc(ctl_heap,5);
-    int res;
 
-    if (~dsdp->flags & (DFLAG_DIST_MONITOR | DFLAG_DIST_MONITOR_NAME)) {
+    if (~ctx->flags & (DFLAG_DIST_MONITOR | DFLAG_DIST_MONITOR_NAME)) {
         /*
          * Receiver does not support DOP_DEMONITOR_P (see dsig_send_monitor)
          */
         return ERTS_DSIG_SEND_OK;
     }
 
-    UseTmpHeapNoproc(5);
-    ctl = TUPLE4(&ctl_heap[0],
+    ctl = TUPLE4(&ctx->ctl_heap[0],
 		 make_small(DOP_DEMONITOR_P),
 		 watcher, watched, ref);
 
-    res = dsig_send_ctl(dsdp, ctl, force);
-    UnUseTmpHeapNoproc(5);
-    return res;
+    return dsig_send_ctl(ctx, ctl);
 }
 
-static int can_send_seqtrace_token(ErtsSendContext* ctx, Eterm token) {
+static int can_send_seqtrace_token(ErtsDSigSendContext* ctx, Eterm token) {
     Eterm label;
 
-    if (ctx->dsd.flags & DFLAG_BIG_SEQTRACE_LABELS) {
+    if (ctx->flags & DFLAG_BIG_SEQTRACE_LABELS) {
         /* The other end is capable of handling arbitrary seq_trace labels. */
         return 1;
     }
@@ -947,11 +1034,11 @@ static int can_send_seqtrace_token(ErtsSendContext* ctx, Eterm token) {
 }
 
 int
-erts_dsig_send_msg(Eterm remote, Eterm message, ErtsSendContext* ctx)
+erts_dsig_send_msg(ErtsDSigSendContext* ctx, Eterm remote, Eterm message)
 {
     Eterm ctl;
     Eterm token = NIL;
-    Process *sender = ctx->dsd.proc;
+    Process *sender = ctx->c_p;
     int res;
 #ifdef USE_VM_PROBES
     Sint tok_label = 0;
@@ -972,7 +1059,7 @@ erts_dsig_send_msg(Eterm remote, Eterm message, ErtsSendContext* ctx)
     *node_name = *sender_name = *receiver_name = '\0';
     if (DTRACE_ENABLED(message_send) || DTRACE_ENABLED(message_send_remote)) {
         erts_snprintf(node_name, sizeof(DTRACE_CHARBUF_NAME(node_name)),
-                      "%T", ctx->dsd.dep->sysname);
+                      "%T", ctx->dep->sysname);
         erts_snprintf(sender_name, sizeof(DTRACE_CHARBUF_NAME(sender_name)),
                       "%T", sender->common.id);
         erts_snprintf(receiver_name, sizeof(DTRACE_CHARBUF_NAME(receiver_name)),
@@ -992,7 +1079,7 @@ erts_dsig_send_msg(Eterm remote, Eterm message, ErtsSendContext* ctx)
 
         send_token = (token != NIL && can_send_seqtrace_token(ctx, token));
 
-        if (ctx->dsd.flags & DFLAG_SEND_SENDER) {
+        if (ctx->flags & DFLAG_SEND_SENDER) {
             dist_op = make_small(send_token ?
                                  DOP_SEND_SENDER_TT :
                                  DOP_SEND_SENDER);
@@ -1015,21 +1102,18 @@ erts_dsig_send_msg(Eterm remote, Eterm message, ErtsSendContext* ctx)
             msize, tok_label, tok_lastcnt, tok_serial);
     DTRACE7(message_send_remote, sender_name, node_name, receiver_name,
             msize, tok_label, tok_lastcnt, tok_serial);
-    ctx->dss.ctl = ctl;
-    ctx->dss.msg = message;
-    ctx->dss.force_busy = 0;
-    res = erts_dsig_send(&ctx->dsd, &ctx->dss);
+    ctx->ctl = ctl;
+    ctx->msg = message;
+    res = erts_dsig_send(ctx);
     return res;
 }
 
 int
-erts_dsig_send_reg_msg(Eterm remote_name, Eterm message,
-		       ErtsSendContext* ctx)
+erts_dsig_send_reg_msg(ErtsDSigSendContext* ctx, Eterm remote_name, Eterm message)
 {
     Eterm ctl;
     Eterm token = NIL;
-    Process *sender = ctx->dsd.proc;
-    int res;
+    Process *sender = ctx->c_p;
 #ifdef USE_VM_PROBES
     Sint tok_label = 0;
     Sint tok_lastcnt = 0;
@@ -1049,7 +1133,7 @@ erts_dsig_send_reg_msg(Eterm remote_name, Eterm message,
     *node_name = *sender_name = *receiver_name = '\0';
     if (DTRACE_ENABLED(message_send) || DTRACE_ENABLED(message_send_remote)) {
         erts_snprintf(node_name, sizeof(DTRACE_CHARBUF_NAME(node_name)),
-                      "%T", ctx->dsd.dep->sysname);
+                      "%T", ctx->dep->sysname);
         erts_snprintf(sender_name, sizeof(DTRACE_CHARBUF_NAME(sender_name)),
                       "%T", sender->common.id);
         erts_snprintf(receiver_name, sizeof(DTRACE_CHARBUF_NAME(receiver_name)),
@@ -1074,23 +1158,19 @@ erts_dsig_send_reg_msg(Eterm remote_name, Eterm message,
             msize, tok_label, tok_lastcnt, tok_serial);
     DTRACE7(message_send_remote, sender_name, node_name, receiver_name,
             msize, tok_label, tok_lastcnt, tok_serial);
-    ctx->dss.ctl = ctl;
-    ctx->dss.msg = message;
-    ctx->dss.force_busy = 0;
-    res = erts_dsig_send(&ctx->dsd, &ctx->dss);
-    return res;
+    ctx->ctl = ctl;
+    ctx->msg = message;
+    return erts_dsig_send(ctx);
 }
 
 /* local has died, deliver the exit signal to remote */
 int
-erts_dsig_send_exit_tt(ErtsDSigData *dsdp, Eterm local, Eterm remote, 
+erts_dsig_send_exit_tt(ErtsDSigSendContext *ctx, Eterm local, Eterm remote, 
 		       Eterm reason, Eterm token)
 {
-    Eterm ctl;
-    DeclareTmpHeapNoproc(ctl_heap,6);
-    int res;
+    Eterm ctl, msg = THE_NON_VALUE;
 #ifdef USE_VM_PROBES
-    Process *sender = dsdp->proc;
+    Process *sender = ctx->c_p;
     Sint tok_label = 0;
     Sint tok_lastcnt = 0;
     Sint tok_serial = 0;
@@ -1100,20 +1180,29 @@ erts_dsig_send_exit_tt(ErtsDSigData *dsdp, Eterm local, Eterm remote,
     DTRACE_CHARBUF(reason_str, 128);
 #endif
 
-    UseTmpHeapNoproc(6);
+    if (ctx->dep->flags & DFLAG_EXIT_PAYLOAD)
+        msg = reason;
+
     if (have_seqtrace(token)) {
-	seq_trace_update_send(dsdp->proc);
+	seq_trace_update_send(ctx->c_p);
 	seq_trace_output_exit(token, reason, SEQ_TRACE_SEND, remote, local);
-	ctl = TUPLE5(&ctl_heap[0],
-		     make_small(DOP_EXIT_TT), local, remote, token, reason);
+        if (ctx->dep->flags & DFLAG_EXIT_PAYLOAD) {
+            ctl = TUPLE4(&ctx->ctl_heap[0],
+                         make_small(DOP_PAYLOAD_EXIT_TT), local, remote, token);
+        } else
+            ctl = TUPLE5(&ctx->ctl_heap[0],
+                         make_small(DOP_EXIT_TT), local, remote, token, reason);
     } else {
-	ctl = TUPLE4(&ctl_heap[0], make_small(DOP_EXIT), local, remote, reason);
+        if (ctx->dep->flags & DFLAG_EXIT_PAYLOAD)
+            ctl = TUPLE3(&ctx->ctl_heap[0], make_small(DOP_PAYLOAD_EXIT), local, remote);
+        else
+            ctl = TUPLE4(&ctx->ctl_heap[0], make_small(DOP_EXIT), local, remote, reason);
     }
 #ifdef USE_VM_PROBES
     *node_name = *sender_name = *remote_name = '\0';
     if (DTRACE_ENABLED(process_exit_signal_remote)) {
         erts_snprintf(node_name, sizeof(DTRACE_CHARBUF_NAME(node_name)),
-                      "%T", dsdp->dep->sysname);
+                      "%T", ctx->dep->sysname);
         erts_snprintf(sender_name, sizeof(DTRACE_CHARBUF_NAME(sender_name)),
                       "%T", sender->common.id);
         erts_snprintf(remote_name, sizeof(DTRACE_CHARBUF_NAME(remote_name)),
@@ -1129,73 +1218,159 @@ erts_dsig_send_exit_tt(ErtsDSigData *dsdp, Eterm local, Eterm remote,
 #endif
     DTRACE7(process_exit_signal_remote, sender_name, node_name,
             remote_name, reason_str, tok_label, tok_lastcnt, tok_serial);
-    /* forced, i.e ignore busy */
-    res = dsig_send_ctl(dsdp, ctl, 1);
-    UnUseTmpHeapNoproc(6);
-    return res;
+    return dsig_send_exit(ctx, ctl, msg);
 }
 
 int
-erts_dsig_send_exit(ErtsDSigData *dsdp, Eterm local, Eterm remote, Eterm reason)
+erts_dsig_send_exit(ErtsDSigSendContext *ctx, Eterm local, Eterm remote, Eterm reason)
 {
-    DeclareTmpHeapNoproc(ctl_heap,5);
-    int res;
-    Eterm ctl;
+    Eterm ctl, msg = ctx->dep->flags & DFLAG_EXIT_PAYLOAD ? reason : THE_NON_VALUE;
 
-    UseTmpHeapNoproc(5);
-    ctl = TUPLE4(&ctl_heap[0],
-		 make_small(DOP_EXIT), local, remote, reason);
-    /* forced, i.e ignore busy */
-    res =  dsig_send_ctl(dsdp, ctl, 1);
-    UnUseTmpHeapNoproc(5);
-    return res;
+    if (ctx->dep->flags & DFLAG_EXIT_PAYLOAD) {
+        ctl = TUPLE3(&ctx->ctl_heap[0], make_small(DOP_PAYLOAD_EXIT), local, remote);
+        msg = reason;
+    } else {
+        ctl = TUPLE4(&ctx->ctl_heap[0], make_small(DOP_EXIT), local, remote, reason);
+        msg = THE_NON_VALUE;
+    }
+    return dsig_send_exit(ctx, ctl, msg);
 }
 
 int
-erts_dsig_send_exit2(ErtsDSigData *dsdp, Eterm local, Eterm remote, Eterm reason)
+erts_dsig_send_exit2(ErtsDSigSendContext *ctx, Eterm local, Eterm remote, Eterm reason)
 {
-    DeclareTmpHeapNoproc(ctl_heap,5);
-    int res;
-    Eterm ctl;
+    Eterm ctl, msg;
 
-    UseTmpHeapNoproc(5);
-    ctl = TUPLE4(&ctl_heap[0],
-		 make_small(DOP_EXIT2), local, remote, reason);
+    if (ctx->dep->flags & DFLAG_EXIT_PAYLOAD) {
+        ctl = TUPLE3(&ctx->ctl_heap[0],
+                     make_small(DOP_PAYLOAD_EXIT2), local, remote);
+        msg = reason;
+    } else {
+        ctl = TUPLE4(&ctx->ctl_heap[0],
+                     make_small(DOP_EXIT2), local, remote, reason);
+        msg = THE_NON_VALUE;
+    }
 
-    res = dsig_send_ctl(dsdp, ctl, 0);
-    UnUseTmpHeapNoproc(5);
-    return res;
+    return dsig_send_exit(ctx, ctl, msg);
 }
 
 
 int
-erts_dsig_send_group_leader(ErtsDSigData *dsdp, Eterm leader, Eterm remote)
+erts_dsig_send_group_leader(ErtsDSigSendContext *ctx, Eterm leader, Eterm remote)
 {
-    DeclareTmpHeapNoproc(ctl_heap,4);
-    int res;
     Eterm ctl;
 
-    UseTmpHeapNoproc(4);
-    ctl = TUPLE3(&ctl_heap[0],
+    ctl = TUPLE3(&ctx->ctl_heap[0],
 		 make_small(DOP_GROUP_LEADER), leader, remote);
 
-    res = dsig_send_ctl(dsdp, ctl, 0);
-    UnUseTmpHeapNoproc(4);
-    return res;
+    return dsig_send_ctl(ctx, ctl);
 }
 
-#if defined(PURIFY)
-#  define PURIFY_MSG(msg) \
-    purify_printf("%s, line %d: %s", __FILE__, __LINE__, msg)
-#elif defined(VALGRIND)
-#include <valgrind/valgrind.h>
-#include <valgrind/memcheck.h>
+#define ERTS_RBT_PREFIX dist_seq
+#define ERTS_RBT_T DistSeqNode
+#define ERTS_RBT_KEY_T Uint
+#define ERTS_RBT_FLAGS_T int
+#define ERTS_RBT_INIT_EMPTY_TNODE(T)            \
+    do {                                        \
+        (T)->parent = NULL;                     \
+        (T)->left = NULL;                       \
+        (T)->right = NULL;                      \
+        (T)->is_red = 0;                        \
+    } while(0)
+#define ERTS_RBT_IS_RED(T) ((T)->is_red)
+#define ERTS_RBT_SET_RED(T) ((T)->is_red = 1)
+#define ERTS_RBT_IS_BLACK(T) (!ERTS_RBT_IS_RED(T))
+#define ERTS_RBT_SET_BLACK(T) ((T)->is_red = 0)
+#define ERTS_RBT_GET_FLAGS(T) ((T)->is_red)
+#define ERTS_RBT_SET_FLAGS(T, F) ((T)->is_red = F)
+#define ERTS_RBT_GET_PARENT(T) ((T)->parent)
+#define ERTS_RBT_SET_PARENT(T, P) ((T)->parent = P)
+#define ERTS_RBT_GET_RIGHT(T) ((T)->right)
+#define ERTS_RBT_SET_RIGHT(T, R) ((T)->right = (R))
+#define ERTS_RBT_GET_LEFT(T) ((T)->left)
+#define ERTS_RBT_SET_LEFT(T, L) ((T)->left = (L))
+#define ERTS_RBT_GET_KEY(T) ((T)->seq_id)
+#define ERTS_RBT_IS_LT(KX, KY) (KX < KY)
+#define ERTS_RBT_IS_EQ(KX, KY) (KX == KY)
+#define ERTS_RBT_WANT_DELETE
+#define ERTS_RBT_WANT_LOOKUP_INSERT
+#define ERTS_RBT_WANT_LOOKUP
+#define ERTS_RBT_WANT_FOREACH
+#define ERTS_RBT_WANT_FOREACH_DESTROY_YIELDING
+
+#include "erl_rbtree.h"
+
+struct erts_debug_dist_seq_tree_foreach_iter_arg {
+    int (*func)(DistSeqNode *, void *, Sint);
+    void *arg;
+};
 
-#  define PURIFY_MSG(msg)                                                    \
-    VALGRIND_PRINTF("%s, line %d: %s", __FILE__, __LINE__, msg)
-#else
-#  define PURIFY_MSG(msg)
-#endif
+static int
+erts_debug_dist_seq_tree_foreach_iter(DistSeqNode *seq, void *arg, Sint reds)
+{
+    struct erts_debug_dist_seq_tree_foreach_iter_arg *state = arg;
+    return state->func(seq, state->arg, reds);
+}
+
+void
+erts_debug_dist_seq_tree_foreach(DistEntry *dep, int (*func)(DistSeqNode *, void *, Sint), void *arg)
+{
+    struct erts_debug_dist_seq_tree_foreach_iter_arg state;
+    state.func = func;
+    state.arg = arg;
+    dist_seq_rbt_foreach(dep->sequences, erts_debug_dist_seq_tree_foreach_iter, &state);
+}
+
+static int dist_seq_cleanup(DistSeqNode *seq, void *unused, Sint reds)
+{
+    erts_free_dist_ext_copy(erts_get_dist_ext(&seq->hfrag));
+    free_message_buffer(&seq->hfrag);
+    return 1;
+}
+
+typedef struct {
+    DistSeqNode *root;
+    dist_seq_rbt_yield_state_t rbt_ystate;
+} DistSeqNodeYieldState;
+
+int
+erts_dist_seq_tree_foreach_delete_yielding(DistSeqNode **root,
+                                           void **vyspp,
+                                           Sint limit)
+{
+    DistSeqNodeYieldState ys = {*root, ERTS_RBT_YIELD_STAT_INITER};
+    DistSeqNodeYieldState *ysp;
+    int res;
+
+    ysp = (DistSeqNodeYieldState *) *vyspp;
+    if (!ysp) {
+        *root = NULL;
+	ysp = &ys;
+    }
+    res = dist_seq_rbt_foreach_destroy_yielding(&ysp->root,
+                                               dist_seq_cleanup,
+                                               NULL,
+                                               &ysp->rbt_ystate,
+                                               limit);
+    if (res > 0) {
+	if (ysp != &ys)
+	    erts_free(ERTS_ALC_T_SEQ_YIELD_STATE, ysp);
+	*vyspp = NULL;
+    }
+    else {
+
+	if (ysp == &ys) {
+	    ysp = erts_alloc(ERTS_ALC_T_SEQ_YIELD_STATE,
+			     sizeof(DistSeqNodeYieldState));
+	    sys_memcpy((void *) ysp, (void *) &ys,
+		       sizeof(DistSeqNodeYieldState));
+	}
+
+	*vyspp = (void *) ysp;
+    }
+
+    return res;
+}
 
 /*
 ** Input from distribution port.
@@ -1212,10 +1387,13 @@ int erts_net_message(Port *prt,
                      Uint32 conn_id,
 		     byte *hbuf,
 		     ErlDrvSizeT hlen,
+                     Binary *bin,
 		     byte *buf,
 		     ErlDrvSizeT len)
 {
-    ErtsDistExternal ede;
+    ErtsDistExternal ede, *edep = &ede;
+    ErtsDistExternalData ede_data;
+    ErlHeapFragment *ede_hfrag = NULL;
     Sint ctl_len;
     Eterm arg;
     Eterm from, to;
@@ -1227,10 +1405,8 @@ int erts_net_message(Port *prt,
     DeclareTmpHeapNoproc(ctl_default,DIST_CTL_DEFAULT_SIZE);
     Eterm* ctl = ctl_default;
     ErtsHeapFactory factory;
-    Eterm* hp;
     Sint type;
     Eterm token;
-    Eterm token_size;
     Uint tuple_arity;
     int res;
 #ifdef ERTS_DIST_MSG_DBG
@@ -1256,69 +1432,149 @@ int erts_net_message(Port *prt,
     }
 
 #ifdef ERTS_RAW_DIST_MSG_DBG
-    erts_fprintf(stderr, "<< ");
+    erts_fprintf(dbg_file, "RECV: ");
     bw(buf, len);
 #endif
 
-    res = erts_prepare_dist_ext(&ede, buf, len, dep, conn_id, dep->cache);
+    ede.data = &ede_data;
+
+    res = erts_prepare_dist_ext(&ede, buf, len, bin, dep, conn_id, dep->cache);
 
     switch (res) {
     case ERTS_PREP_DIST_EXT_CLOSED:
         return 0; /* Connection not alive; ignore signal... */
     case ERTS_PREP_DIST_EXT_FAILED:
 #ifdef ERTS_DIST_MSG_DBG
-	erts_fprintf(stderr, "DIST MSG DEBUG: erts_prepare_dist_ext() failed:\n");
+	erts_fprintf(dbg_file, "DIST MSG DEBUG: erts_prepare_dist_ext() failed:\n");
 	bw(buf, orig_len);
 #endif
         goto data_error;
     case ERTS_PREP_DIST_EXT_SUCCESS:
-	ctl_len = erts_decode_dist_ext_size(&ede);
+	ctl_len = erts_decode_dist_ext_size(&ede, 1, 0);
         if (ctl_len < 0) {
 #ifdef ERTS_DIST_MSG_DBG
-            erts_fprintf(stderr, "DIST MSG DEBUG: erts_decode_dist_ext_size(CTL) failed:\n");
+            erts_fprintf(dbg_file, "DIST MSG DEBUG: erts_decode_dist_ext_size(CTL) failed:\n");
             bw(buf, orig_len);
 #endif
             PURIFY_MSG("data error");
             goto data_error;
         }
+
+        /* A non-fragmented message */
+        if (!ede.data->seq_id) {
+            if (ctl_len > DIST_CTL_DEFAULT_SIZE) {
+                ctl = erts_alloc(ERTS_ALC_T_DCTRL_BUF, ctl_len * sizeof(Eterm));
+            }
+
+            erts_factory_tmp_init(&factory, ctl, ctl_len, ERTS_ALC_T_DCTRL_BUF);
+            break;
+        } else {
+            DistSeqNode *seq;
+            Uint sz = erts_dist_ext_size(&ede);
+            Uint used_sz = ctl_len * sizeof(Eterm);
+
+            /* We calculate the size of the heap fragment to be allocated.
+               The used_size part has to be larger that the ctl data and the
+               DistSeqNode. */
+            if (used_sz + (sizeof(ErlHeapFragment) - sizeof(Eterm)) < sizeof(DistSeqNode))
+                used_sz = sizeof(DistSeqNode) - (sizeof(ErlHeapFragment) - sizeof(Eterm));
+
+            seq = (DistSeqNode *)new_message_buffer((sz + used_sz) / sizeof(Eterm));
+            seq->hfrag.used_size = used_sz / sizeof(Eterm);
+
+            seq->ctl_len = ctl_len;
+            seq->seq_id = ede.data->seq_id;
+            seq->cnt = ede.data->frag_id;
+            if (dist_seq_rbt_lookup_insert(&dep->sequences, seq) != NULL) {
+                free_message_buffer(&seq->hfrag);
+                goto data_error;
+            }
+
+            erts_make_dist_ext_copy(&ede, erts_get_dist_ext(&seq->hfrag));
+
+            if (ede.data->frag_id > 1) {
+                seq->cnt--;
+                return 0;
+            }
+        }
+
+        /* fall through, the first fragment in the sequence was the last fragment */
+    case ERTS_PREP_DIST_EXT_FRAG_CONT: {
+        DistSeqNode *seq = dist_seq_rbt_lookup(dep->sequences, ede.data->seq_id);
+
+        if (!seq)
+            goto data_error;
+
+        /* If we did a fall-though we already did this */
+        if (res == ERTS_PREP_DIST_EXT_FRAG_CONT)
+            erts_dist_ext_frag(&ede_data, erts_get_dist_ext(&seq->hfrag));
+
+        /* Verify that the fragments have arrived in the correct order */
+        if (seq->cnt != ede.data->frag_id)
+            goto data_error;
+
+        seq->cnt--;
+
+        /* Check if this was the last fragment */
+        if (ede.data->frag_id > 1)
+            return 0;
+
+        /* Last fragment arrived, time to dispatch the signal */
+        dist_seq_rbt_delete(&dep->sequences, seq);
+        ctl_len = seq->ctl_len;
+
+        /* Now that we no longer need the DistSeqNode we re-use the heapfragment
+           to decode the ctl msg into. We don't need the ctl message to be in
+           the heapfragment, but we decode into the heapfragment speculatively
+           in case there is a trace token that we need. */
+        erts_factory_heap_frag_init(&factory, &seq->hfrag);
+        edep = erts_get_dist_ext(&seq->hfrag);
+        ede_hfrag = &seq->hfrag;
+
         break;
+    }
     default:
         ERTS_INTERNAL_ERROR("Unexpected result from erts_prepare_dist_ext()");
         break;
     }
 
-    if (ctl_len > DIST_CTL_DEFAULT_SIZE) {
-	ctl = erts_alloc(ERTS_ALC_T_DCTRL_BUF, ctl_len * sizeof(Eterm));
-    }
-    hp = ctl;
-
-    erts_factory_tmp_init(&factory, ctl, ctl_len, ERTS_ALC_T_DCTRL_BUF);
-    arg = erts_decode_dist_ext(&factory, &ede);
+    arg = erts_decode_dist_ext(&factory, edep, 1);
     if (is_non_value(arg)) {
 #ifdef ERTS_DIST_MSG_DBG
-	erts_fprintf(stderr, "DIST MSG DEBUG: erts_decode_dist_ext(CTL) failed:\n");
+	erts_fprintf(dbg_file, "DIST MSG DEBUG: erts_decode_dist_ext(CTL) failed:\n");
 	bw(buf, orig_len);
 #endif
 	PURIFY_MSG("data error");
 	goto decode_error;
     }
 
-#ifdef ERTS_DIST_MSG_DBG
-    erts_fprintf(stderr, "<< CTL: %T\n", arg);
-#endif
+    /* Fill the unused part of the hfrag with a bignum header */
+    if (ede_hfrag && ede_hfrag->mem + ede_hfrag->used_size > factory.hp) {
+        Uint slot = factory.hp - ede_hfrag->mem;
+        ede_hfrag->mem[slot] = make_pos_bignum_header(ede_hfrag->used_size - slot - 1);
+    }
 
     if (is_not_tuple(arg) || 
 	(tuple = tuple_val(arg), (tuple_arity = arityval(*tuple)) < 1) ||
 	is_not_small(tuple[1])) {
+#ifdef ERTS_DIST_MSG_DBG
+        if (is_tuple(arg) && arityval(*tuple) > 1)
+            erts_fprintf(dbg_file, "RECV: CTL: %s: %.80T\n",
+                         erts_dop_to_string(unsigned_val(tuple[1])), arg);
+#endif
  	goto invalid_message;
     }
 
-    token_size = 0;
+#ifdef ERTS_DIST_MSG_DBG
+    erts_fprintf(dbg_file, "RECV: CTL: %s: %.80T\n",
+                 erts_dop_to_string(unsigned_val(tuple[1])), arg);
+#endif
+
     token = NIL;
 
     switch (type = unsigned_val(tuple[1])) {
     case DOP_LINK: {
-        ErtsDSigData dsd;
+        ErtsDSigSendContext ctx;
         int code;
 
 	if (tuple_arity != 3) {
@@ -1343,10 +1599,7 @@ int erts_net_message(Port *prt,
                                                  from, to);
             ASSERT(ldp->a.other.item == to);
             ASSERT(eq(ldp->b.other.item, from));
-#ifdef DEBUG
-            code =
-#endif
-                erts_link_dist_insert(&ldp->a, dep->mld);
+            code = erts_link_dist_insert(&ldp->a, dep->mld);
             ASSERT(code);
 
             if (erts_proc_sig_send_link(NULL, to, &ldp->b))
@@ -1354,17 +1607,14 @@ int erts_net_message(Port *prt,
 
             /* Failed to send signal; cleanup and reply noproc... */
 
-#ifdef DEBUG
-            code =
-#endif
-                erts_link_dist_delete(&ldp->a);
+            code = erts_link_dist_delete(&ldp->a);
             ASSERT(code);
             erts_link_release_both(ldp);
         }
 
-        code = erts_dsig_prepare(&dsd, dep, NULL, 0, ERTS_DSP_NO_LOCK, 0, 0);
+        code = erts_dsig_prepare(&ctx, dep, NULL, 0, ERTS_DSP_NO_LOCK, 1, 1, 0);
         if (code == ERTS_DSIG_PREP_CONNECTED) {
-            code = erts_dsig_send_exit(&dsd, to, from, am_noproc);
+            code = erts_dsig_send_exit(&ctx, to, from, am_noproc);
             ASSERT(code == ERTS_DSIG_SEND_OK);
         }
 
@@ -1397,7 +1647,7 @@ int erts_net_message(Port *prt,
 	/* A remote process wants to monitor us, we get:
 	   {DOP_MONITOR_P, Remote pid, local pid or name, ref} */
 	Eterm pid, name;
-        ErtsDSigData dsd;
+        ErtsDSigSendContext ctx;
         int code;
 
 	if (tuple_arity != 4) {
@@ -1452,10 +1702,9 @@ int erts_net_message(Port *prt,
 
         }
 
-        code = erts_dsig_prepare(&dsd, dep, NULL, 0, ERTS_DSP_NO_LOCK, 0, 0);
+        code = erts_dsig_prepare(&ctx, dep, NULL, 0, ERTS_DSP_NO_LOCK, 1, 1, 0);
         if (code == ERTS_DSIG_PREP_CONNECTED) {
-            code = erts_dsig_send_m_exit(&dsd, watcher, watched, ref,
-                                         am_noproc);
+            code = erts_dsig_send_m_exit(&ctx, watcher, watched, ref, am_noproc);
             ASSERT(code == ERTS_DSIG_SEND_OK);
         }
 
@@ -1514,7 +1763,6 @@ int erts_net_message(Port *prt,
 	    goto invalid_message;
 	}
 
-	token_size = size_object(tuple[5]);
 	/* Fall through ... */
     case DOP_REG_SEND:
 	/* {DOP_REG_SEND, From, Cookie, ToName} -- Message */
@@ -1529,7 +1777,7 @@ int erts_net_message(Port *prt,
 	}
 
 #ifdef ERTS_DIST_MSG_DBG
-	dist_msg_dbg(&ede, "MSG", buf, orig_len);
+	dist_msg_dbg(edep, "MSG", buf, orig_len);
 #endif
 
 	from = tuple[2];
@@ -1539,35 +1787,25 @@ int erts_net_message(Port *prt,
 	}
 	rp = erts_whereis_process(NULL, 0, to, 0, 0);
 	if (rp) {
-	    Uint xsize = (type == DOP_REG_SEND
-			  ? 0
-			  : ERTS_HEAP_FRAG_SIZE(token_size));
 	    ErtsProcLocks locks = 0;
-	    ErtsDistExternal *ede_copy;
 
-	    ede_copy = erts_make_dist_ext_copy(&ede, xsize);
 	    if (type == DOP_REG_SEND) {
 		token = NIL;
 	    } else {
-		ErlHeapFragment *heap_frag;
-		ErlOffHeap *ohp;
-		ASSERT(xsize);
-		heap_frag = erts_dist_ext_trailer(ede_copy);
-		ERTS_INIT_HEAP_FRAG(heap_frag, token_size, token_size);
-		hp = heap_frag->mem;
-		ohp = &heap_frag->off_heap;
 		token = tuple[5];
-		token = copy_struct(token, token_size, &hp, ohp);
 	    }
 
-	    erts_queue_dist_message(rp, locks, ede_copy, token, from);
+            erts_queue_dist_message(rp, locks, edep, ede_hfrag, token, from);
+
 	    if (locks)
 		erts_proc_unlock(rp, locks);
-	}
+	} else if (ede_hfrag != NULL) {
+            erts_free_dist_ext_copy(erts_get_dist_ext(ede_hfrag));
+            free_message_buffer(ede_hfrag);
+        }
 	break;
 
     case DOP_SEND_SENDER_TT: {
-        Uint xsize;
     case DOP_SEND_TT:
 
 	if (tuple_arity != 4) {
@@ -1575,15 +1813,12 @@ int erts_net_message(Port *prt,
 	}
 
 	token = tuple[4];
-	token_size = size_object(token);
-        xsize = ERTS_HEAP_FRAG_SIZE(token_size);
         goto send_common;
 
     case DOP_SEND_SENDER:
     case DOP_SEND:
 
         token = NIL;
-        xsize = 0;
 	if (tuple_arity != 3)
 	    goto invalid_message;
 
@@ -1599,48 +1834,50 @@ int erts_net_message(Port *prt,
                : tuple[2] == am_Empty);
 
 #ifdef ERTS_DIST_MSG_DBG
-	dist_msg_dbg(&ede, "MSG", buf, orig_len);
+	dist_msg_dbg(edep, "MSG", buf, orig_len);
 #endif
 	to = tuple[3];
 	if (is_not_pid(to)) {
 	    goto invalid_message;
 	}
 	rp = erts_proc_lookup(to);
+
 	if (rp) {
 	    ErtsProcLocks locks = 0;
-	    ErtsDistExternal *ede_copy;
-
-	    ede_copy = erts_make_dist_ext_copy(&ede, xsize);
-	    if (is_not_nil(token)) {
-		ErlHeapFragment *heap_frag;
-		ErlOffHeap *ohp;
-		ASSERT(xsize);
-		heap_frag = erts_dist_ext_trailer(ede_copy);
-		ERTS_INIT_HEAP_FRAG(heap_frag, token_size, token_size);
-		hp = heap_frag->mem;
-		ohp = &heap_frag->off_heap;
-		token = copy_struct(token, token_size, &hp, ohp);
-	    }
 
-	    erts_queue_dist_message(rp, locks, ede_copy, token, am_Empty);
+	    erts_queue_dist_message(rp, locks, edep, ede_hfrag, token, am_Empty);
 	    if (locks)
 		erts_proc_unlock(rp, locks);
-	}
+        } else if (ede_hfrag != NULL) {
+            erts_free_dist_ext_copy(erts_get_dist_ext(ede_hfrag));
+            free_message_buffer(ede_hfrag);
+        }
+	
 	break;
     }
 
+    case DOP_PAYLOAD_MONITOR_P_EXIT:
     case DOP_MONITOR_P_EXIT: {
+
 	/* We are monitoring a process on the remote node which dies, we get
 	   {DOP_MONITOR_P_EXIT, Remote pid or name, Local pid, ref, reason} */
-	   
-	if (tuple_arity != 5) {
-	    goto invalid_message;
-	}
 
-	watched = tuple[2];  /* remote proc or name which died */
-	watcher = tuple[3];
+        watched = tuple[2];  /* remote proc or name which died */
+        watcher = tuple[3];
 	ref     = tuple[4];
-	reason  = tuple[5];
+
+        if (type == DOP_PAYLOAD_MONITOR_P_EXIT) {
+            if (tuple_arity != 4) {
+                goto invalid_message;
+            }
+            reason = THE_NON_VALUE;
+        } else {
+            if (tuple_arity != 5) {
+                goto invalid_message;
+            }
+            reason = tuple[5];
+            edep = NULL;
+        }
 
 	if (is_not_ref(ref))
 	    goto invalid_message;
@@ -1656,70 +1893,152 @@ int erts_net_message(Port *prt,
             goto invalid_message;
         }
 
-        erts_proc_sig_send_dist_monitor_down(dep, ref, watched,
-                                             watcher, reason);
+        if (!erts_proc_lookup(watcher)) {
+            if (ede_hfrag != NULL) {
+                erts_free_dist_ext_copy(erts_get_dist_ext(ede_hfrag));
+                free_message_buffer(ede_hfrag);
+            }
+            break; /* Process not alive */
+        }
+
+#ifdef ERTS_DIST_MSG_DBG
+        if (reason == THE_NON_VALUE) {
+            dist_msg_dbg(edep, "MSG", buf, orig_len);
+        }
+#endif
+
+        erts_proc_sig_send_dist_monitor_down(
+            dep, ref, watched, watcher, edep, ede_hfrag, reason);
 	break;
     }
 
+    case DOP_PAYLOAD_EXIT:
+    case DOP_PAYLOAD_EXIT_TT:
     case DOP_EXIT_TT:
     case DOP_EXIT: {
+
 	/* 'from', which 'to' is linked to, died */
+        from = tuple[2];
+        to = tuple[3];
+
 	if (type == DOP_EXIT) {
 	    if (tuple_arity != 4) {
 		goto invalid_message;
 	    }
-	    
-	    from = tuple[2];
-	    to = tuple[3];
-	    reason = tuple[4];
 	    token = NIL;
-	} else {
+	    reason = tuple[4];
+            edep = NULL;
+	} else if (type == DOP_EXIT_TT){
 	    if (tuple_arity != 5) {
 		goto invalid_message;
 	    }
-	    from = tuple[2];
-	    to = tuple[3];
 	    token = tuple[4];
 	    reason = tuple[5];
-	}
+            edep = NULL;
+	} else if (type == DOP_PAYLOAD_EXIT) {
+            if (tuple_arity != 3) {
+		goto invalid_message;
+	    }
+            token = NIL;
+            reason = THE_NON_VALUE;
+        } else {
+            if (tuple_arity != 4) {
+		goto invalid_message;
+	    }
+            token = tuple[4];
+            reason = THE_NON_VALUE;
+        }
 	if (is_not_external_pid(from)
             || dep != external_pid_dist_entry(from)
             || is_not_internal_pid(to)) {
 	    goto invalid_message;
 	}
 
+        if (!erts_proc_lookup(to)) {
+            if (ede_hfrag != NULL) {
+                erts_free_dist_ext_copy(erts_get_dist_ext(ede_hfrag));
+                free_message_buffer(ede_hfrag);
+            }
+            break; /* Process not alive */
+        }
+
+#ifdef ERTS_DIST_MSG_DBG
+        if (reason == THE_NON_VALUE) {
+            dist_msg_dbg(edep, "MSG", buf, orig_len);
+        }
+#endif
+
         erts_proc_sig_send_dist_link_exit(dep,
-                                          from, to,
+                                          from, to, edep, ede_hfrag,
                                           reason, token);
 	break;
     }
+    case DOP_PAYLOAD_EXIT2_TT:
+    case DOP_PAYLOAD_EXIT2:
     case DOP_EXIT2_TT:
-    case DOP_EXIT2:
+    case DOP_EXIT2: {
+
 	/* 'from' is send an exit signal to 'to' */
+        from = tuple[2];
+        to = tuple[3];
+
 	if (type == DOP_EXIT2) {
 	    if (tuple_arity != 4) {
 		goto invalid_message;
 	    }
-	    from = tuple[2];
-	    to = tuple[3];
 	    reason = tuple[4];
 	    token = NIL;
-	} else {
+            edep = NULL;
+	} else if (type == DOP_EXIT2_TT) {
 	    if (tuple_arity != 5) {
 		goto invalid_message;
 	    }
-	    from = tuple[2];
-	    to = tuple[3];
 	    token = tuple[4];
 	    reason = tuple[5];
-	}
-	if (is_not_pid(from) || is_not_internal_pid(to)) {
+            edep = NULL;
+	} else if (type == DOP_PAYLOAD_EXIT2) {
+            if (tuple_arity != 3) {
+		goto invalid_message;
+	    }
+            reason = THE_NON_VALUE;
+            token = NIL;
+        } else {
+            if (tuple_arity != 4) {
+		goto invalid_message;
+	    }
+            reason = THE_NON_VALUE;
+            token = tuple[4];
+        }
+	if (is_not_pid(from)
+            || dep != external_pid_dist_entry(from)) {
 	    goto invalid_message;
 	}
+        if (is_not_internal_pid(to)) {
+            if (is_external_pid(to)) {
+		DistEntry *dep = external_pid_dist_entry(to);
+		if (dep == erts_this_dist_entry)
+                    break; /* Old incarnation of this node... */
+            }
+            goto invalid_message;
+        }
 
-        erts_proc_sig_send_exit(NULL, from, to, reason, token, 0);
-	break;
+        if (!erts_proc_lookup(to)) {
+            if (ede_hfrag != NULL) {
+                erts_free_dist_ext_copy(erts_get_dist_ext(ede_hfrag));
+                free_message_buffer(ede_hfrag);
+            }
+            break; /* Process not alive */
+        }
 
+#ifdef ERTS_DIST_MSG_DBG
+        if (reason == THE_NON_VALUE) {
+            dist_msg_dbg(edep, "MSG", buf, orig_len);
+        }
+#endif
+
+        erts_proc_sig_send_dist_exit(dep, from, to, edep, ede_hfrag, reason, token);
+	break;
+    }
     case DOP_GROUP_LEADER:
 	if (tuple_arity != 3) {
 	    goto invalid_message;
@@ -1733,13 +2052,15 @@ int erts_net_message(Port *prt,
         (void) erts_proc_sig_send_group_leader(NULL, to, from, NIL);
 	break;
 
-    default: 
+    default:
 	goto invalid_message;
     }
 
-    erts_factory_close(&factory);
-    if (ctl != ctl_default) {
-	erts_free(ERTS_ALC_T_DCTRL_BUF, (void *) ctl);
+    if (ede_hfrag == NULL) {
+        erts_factory_close(&factory);
+        if (ctl != ctl_default) {
+            erts_free(ERTS_ALC_T_DCTRL_BUF, (void *) ctl);
+        }
     }
     UnUseTmpHeapNoproc(DIST_CTL_DEFAULT_SIZE);
     ERTS_CHK_NO_PROC_LOCKS;
@@ -1752,9 +2073,14 @@ int erts_net_message(Port *prt,
     }
 decode_error:
     PURIFY_MSG("data error");
-    erts_factory_close(&factory);
-    if (ctl != ctl_default) {
-	erts_free(ERTS_ALC_T_DCTRL_BUF, (void *) ctl);
+    if (ede_hfrag == NULL) {
+        erts_factory_close(&factory);
+        if (ctl != ctl_default) {
+            erts_free(ERTS_ALC_T_DCTRL_BUF, (void *) ctl);
+        }
+    } else {
+        erts_free_dist_ext_copy(erts_get_dist_ext(ede_hfrag));
+        free_message_buffer(ede_hfrag);
     }
 data_error:
     UnUseTmpHeapNoproc(DIST_CTL_DEFAULT_SIZE);
@@ -1763,18 +2089,21 @@ data_error:
     return -1;
 }
 
-static int dsig_send_ctl(ErtsDSigData* dsdp, Eterm ctl, int force_busy)
+static int dsig_send_exit(ErtsDSigSendContext *ctx, Eterm ctl, Eterm msg)
+{
+    ctx->ctl = ctl;
+    ctx->msg = msg;
+    return erts_dsig_send(ctx);
+}
+
+static int dsig_send_ctl(ErtsDSigSendContext *ctx, Eterm ctl)
 {
-    struct erts_dsig_send_context ctx;
     int ret;
-    ctx.ctl = ctl;
-    ctx.msg = THE_NON_VALUE;
-    ctx.force_busy = force_busy;
-    ctx.phase = ERTS_DSIG_SEND_PHASE_INIT;
-#ifdef DEBUG
-    ctx.reds = 1; /* provoke assert below (no reduction count without msg) */
-#endif
-    ret = erts_dsig_send(dsdp, &ctx);
+    ctx->ctl = ctl;
+    ctx->msg = THE_NON_VALUE;
+    ctx->from = THE_NON_VALUE;
+    ctx->reds = 1; /* provoke assert below (no reduction count without msg) */
+    ret = erts_dsig_send(ctx);
     ASSERT(ret != ERTS_DSIG_SEND_CONTINUE);
     return ret;
 }
@@ -1805,7 +2134,117 @@ notify_dist_data(Process *c_p, Eterm pid)
 }
 
 int
-erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
+erts_dsig_prepare(ErtsDSigSendContext *ctx,
+		  DistEntry *dep,
+		  Process *proc,
+                  ErtsProcLocks proc_locks,
+		  ErtsDSigPrepLock dspl,
+		  int no_suspend,
+                  int no_trap,
+		  int connect)
+{
+    int res;
+
+    if (!erts_is_alive)
+	return ERTS_DSIG_PREP_NOT_ALIVE;
+    if (!dep) {
+        ASSERT(!connect);
+        return ERTS_DSIG_PREP_NOT_CONNECTED;
+    }
+
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    if (connect) {
+        erts_proc_lc_might_unlock(proc, proc_locks);
+    }
+#endif
+
+retry:
+    erts_de_rlock(dep);
+
+    if (dep->state == ERTS_DE_STATE_CONNECTED) {
+	res = ERTS_DSIG_PREP_CONNECTED;
+    }
+    else if (dep->state == ERTS_DE_STATE_PENDING) {
+	res = ERTS_DSIG_PREP_PENDING;
+    }
+    else if (dep->state == ERTS_DE_STATE_EXITING) {
+	res = ERTS_DSIG_PREP_NOT_CONNECTED;
+	goto fail;
+    }
+    else if (connect) {
+        ASSERT(dep->state == ERTS_DE_STATE_IDLE);
+        erts_de_runlock(dep);
+        if (!erts_auto_connect(dep, proc, proc_locks)) {
+            return ERTS_DSIG_PREP_NOT_ALIVE;
+        }
+	goto retry;
+    }
+    else {
+        ASSERT(dep->state == ERTS_DE_STATE_IDLE);
+	res = ERTS_DSIG_PREP_NOT_CONNECTED;
+	goto fail;
+    }
+
+    if (no_suspend) {
+	if (erts_atomic32_read_acqb(&dep->qflgs) & ERTS_DE_QFLG_BUSY) {
+	    res = ERTS_DSIG_PREP_WOULD_SUSPEND;
+	    goto fail;
+	}
+    }
+
+    ctx->c_p = proc;
+    ctx->dep = dep;
+    ctx->deref_dep = 0;
+    ctx->cid = dep->cid;
+    ctx->connection_id = dep->connection_id;
+    ctx->no_suspend = no_suspend;
+    ctx->no_trap = no_trap;
+    ctx->flags = dep->flags;
+    ctx->return_term = am_true;
+    ctx->phase = ERTS_DSIG_SEND_PHASE_INIT;
+    ctx->from = proc ? proc->common.id : am_undefined;
+    ctx->reds = no_trap ? 1 : (Sint) (ERTS_BIF_REDS_LEFT(proc) * TERM_TO_BINARY_LOOP_FACTOR);
+    if (dspl == ERTS_DSP_NO_LOCK)
+	erts_de_runlock(dep);
+    return res;
+
+ fail:
+    erts_de_runlock(dep);
+    return res;
+}
+
+static
+void erts_schedule_dist_command(Port *prt, DistEntry *dist_entry)
+{
+    DistEntry *dep;
+    Eterm id;
+
+    if (prt) {
+	ERTS_LC_ASSERT(erts_lc_is_port_locked(prt));
+	ASSERT((erts_atomic32_read_nob(&prt->state)
+		& ERTS_PORT_SFLGS_DEAD) == 0);
+
+        dep = (DistEntry*) erts_prtsd_get(prt, ERTS_PRTSD_DIST_ENTRY);
+        ASSERT(dep);
+	id = prt->common.id;
+    }
+    else {
+	ASSERT(dist_entry);
+	ERTS_LC_ASSERT(erts_lc_rwmtx_is_rlocked(&dist_entry->rwmtx)
+			   || erts_lc_rwmtx_is_rwlocked(&dist_entry->rwmtx));
+	ASSERT(is_internal_port(dist_entry->cid));
+
+ 	dep = dist_entry;
+	id = dep->cid;
+    }
+
+    if (!erts_atomic_xchg_mb(&dep->dist_cmd_scheduled, 1))
+	erts_port_task_schedule(id, &dep->dist_cmd, ERTS_PORT_TASK_DIST_CMD);
+}
+
+
+int
+erts_dsig_send(ErtsDSigSendContext *ctx)
 {
     int retval;
     Sint initial_reds = ctx->reds;
@@ -1814,11 +2253,13 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
     while (1) {
 	switch (ctx->phase) {
 	case ERTS_DSIG_SEND_PHASE_INIT:
-	    ctx->flags = dsdp->flags;
-	    ctx->c_p = dsdp->proc;
+	    ctx->flags = ctx->flags;
+	    ctx->c_p = ctx->c_p;
 
-	    if (!ctx->c_p || dsdp->no_suspend)
-		ctx->force_busy = 1;
+	    if (!ctx->c_p) {
+		ctx->no_trap = 1;
+		ctx->no_suspend = 1;
+            }
 
 	    ERTS_LC_ASSERT(!ctx->c_p
 			       || (ERTS_PROC_LOCK_MAIN
@@ -1837,15 +2278,27 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
 	    }
 
     #ifdef ERTS_DIST_MSG_DBG
-            erts_fprintf(stderr, ">> CTL: %T\n", ctx->ctl);
+            erts_fprintf(dbg_file, "SEND: CTL: %s: %.80T\n",
+                         erts_dop_to_string(unsigned_val(tuple_val(ctx->ctl)[1])),
+                         ctx->ctl);
             if (is_value(ctx->msg))
-                erts_fprintf(stderr, "    MSG: %T\n", ctx->msg);
+                erts_fprintf(dbg_file, "    MSG: %.160T\n", ctx->msg);
     #endif
 
 	    ctx->data_size = ctx->max_finalize_prepend;
 	    erts_reset_atom_cache_map(ctx->acmp);
-	    erts_encode_dist_ext_size(ctx->ctl, ctx->flags, ctx->acmp, &ctx->data_size);
 
+	    switch (erts_encode_dist_ext_size(ctx->ctl, ctx->flags,
+                                              ctx->acmp, &ctx->data_size)) {
+            case ERTS_EXT_SZ_OK:
+                break;
+            case ERTS_EXT_SZ_SYSTEM_LIMIT:
+                retval = ERTS_DSIG_SEND_TOO_LRG;
+                goto done;
+            case ERTS_EXT_SZ_YIELD:
+                ERTS_INTERNAL_ERROR("Unexpected yield result");
+                break;
+            }
 	    if (is_non_value(ctx->msg)) {
                 ctx->phase = ERTS_DSIG_SEND_PHASE_ALLOC;
                 break;
@@ -1855,26 +2308,61 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
             ctx->u.sc.level = 0;
 
             ctx->phase = ERTS_DSIG_SEND_PHASE_MSG_SIZE;
-	case ERTS_DSIG_SEND_PHASE_MSG_SIZE:
-	    if (erts_encode_dist_ext_size_int(ctx->msg, ctx, &ctx->data_size)) {
-		retval = ERTS_DSIG_SEND_CONTINUE;
-		goto done;
-	    }
+	case ERTS_DSIG_SEND_PHASE_MSG_SIZE: {
+            ErtsExtSzRes sz_res;
+            sz_res = (!ctx->no_trap
+                      ? erts_encode_dist_ext_size_ctx(ctx->msg,
+                                                      ctx,
+                                                      &ctx->data_size)
+                      : erts_encode_dist_ext_size(ctx->msg,
+                                                  ctx->flags,
+                                                  ctx->acmp,
+                                                  &ctx->data_size));
+            switch (sz_res) {
+            case ERTS_EXT_SZ_OK:
+                break;
+            case ERTS_EXT_SZ_SYSTEM_LIMIT:
+                retval = ERTS_DSIG_SEND_TOO_LRG;
+                goto done;
+            case ERTS_EXT_SZ_YIELD:
+                if (ctx->no_trap)
+                    ERTS_INTERNAL_ERROR("Unexpected yield result");
+                retval = ERTS_DSIG_SEND_CONTINUE;
+                goto done;
+            }
 
 	    ctx->phase = ERTS_DSIG_SEND_PHASE_ALLOC;
+        }
 	case ERTS_DSIG_SEND_PHASE_ALLOC:
 	    erts_finalize_atom_cache_map(ctx->acmp, ctx->flags);
 
-	    ctx->dhdr_ext_size = erts_encode_ext_dist_header_size(ctx->acmp);
-	    ctx->data_size += ctx->dhdr_ext_size;
+            if (ctx->flags & DFLAG_FRAGMENTS && is_value(ctx->msg) && is_not_immed(ctx->msg)) {
+                /* Calculate the max number of fragments that are needed */
+                ASSERT(is_pid(ctx->from) &&
+                       "from has to be a pid because it is used as sequence id");
+                ctx->fragments = ctx->data_size / ERTS_DIST_FRAGMENT_SIZE + 1;
+            } else
+                ctx->fragments = 1;
 
-	    ctx->obuf = alloc_dist_obuf(ctx->data_size);
-	    ctx->obuf->ext_endp = &ctx->obuf->data[0] + ctx->max_finalize_prepend + ctx->dhdr_ext_size;
+	    ctx->dhdr_ext_size = erts_encode_ext_dist_header_size(ctx->acmp, ctx->fragments);
+
+	    ctx->obuf = alloc_dist_obuf(
+                ctx->dhdr_ext_size + ctx->data_size +
+                (ctx->fragments-1) * ERTS_DIST_FRAGMENT_HEADER_SIZE,
+                ctx->fragments);
+            ctx->obuf->ext_start = &ctx->obuf->extp[0];
+	    ctx->obuf->ext_endp = &ctx->obuf->extp[0] + ctx->max_finalize_prepend
+                + ctx->dhdr_ext_size;
 
 	    /* Encode internal version of dist header */
-	    ctx->obuf->extp = erts_encode_ext_dist_header_setup(ctx->obuf->ext_endp, ctx->acmp);
+	    ctx->obuf->extp = erts_encode_ext_dist_header_setup(
+                ctx->obuf->ext_endp, ctx->acmp, ctx->fragments, ctx->from);
 	    /* Encode control message */
 	    erts_encode_dist_ext(ctx->ctl, &ctx->obuf->ext_endp, ctx->flags, ctx->acmp, NULL, NULL);
+
+            ctx->obuf->hdrp = NULL;
+            ctx->obuf->hdr_endp = NULL;
+
 	    if (is_non_value(ctx->msg)) {
                 ctx->obuf->msg_start = NULL;
                 ctx->phase = ERTS_DSIG_SEND_PHASE_FIN;
@@ -1888,44 +2376,137 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
 
             ctx->phase = ERTS_DSIG_SEND_PHASE_MSG_ENCODE;
         case ERTS_DSIG_SEND_PHASE_MSG_ENCODE:
-	    if (erts_encode_dist_ext(ctx->msg, &ctx->obuf->ext_endp, ctx->flags, ctx->acmp, &ctx->u.ec, &ctx->reds)) {
-		retval = ERTS_DSIG_SEND_CONTINUE;
-		goto done;
-	    }
+            if (!ctx->no_trap) {
+                if (erts_encode_dist_ext(ctx->msg, &ctx->obuf->ext_endp, ctx->flags,
+                                         ctx->acmp, &ctx->u.ec, &ctx->reds)) {
+                    retval = ERTS_DSIG_SEND_CONTINUE;
+                    goto done;
+                }
+            } else {
+                erts_encode_dist_ext(ctx->msg, &ctx->obuf->ext_endp, ctx->flags,
+                                     ctx->acmp, NULL, NULL);
+            }
 
-	    ctx->phase = ERTS_DSIG_SEND_PHASE_FIN;
+            ctx->phase = ERTS_DSIG_SEND_PHASE_FIN;
 	case ERTS_DSIG_SEND_PHASE_FIN: {
-	    DistEntry *dep = dsdp->dep;
-	    int suspended = 0;
-	    int resume = 0;
 
 	    ASSERT(ctx->obuf->extp < ctx->obuf->ext_endp);
-	    ASSERT(&ctx->obuf->data[0] <= ctx->obuf->extp - ctx->max_finalize_prepend);
-	    ASSERT(ctx->obuf->ext_endp <= &ctx->obuf->data[0] + ctx->data_size);
+	    ASSERT(ctx->obuf->ext_startp <= ctx->obuf->extp - ctx->max_finalize_prepend);
+	    ASSERT(ctx->obuf->ext_endp <= (byte*)ctx->obuf->ext_startp + ctx->data_size + ctx->dhdr_ext_size);
 
 	    ctx->data_size = ctx->obuf->ext_endp - ctx->obuf->extp;
 
             ctx->obuf->hopefull_flags = ctx->u.ec.hopefull_flags;
-	    /*
+
+            if (ctx->fragments > 1) {
+                int fin_fragments;
+                int i;
+                byte *msg = ctx->obuf->msg_start,
+                    *msg_end = ctx->obuf->ext_endp,
+                    *hdrp = msg_end;
+
+                ASSERT((ctx->obuf->hopefull_flags & ctx->flags) == ctx->obuf->hopefull_flags);
+                ASSERT(get_int64(ctx->obuf->extp + 1 + 1 + 8) == ctx->fragments);
+
+                /* Now that encoding is done we know how large the term will
+                   be so we adjust the number of fragments to send. Note that
+                   this can mean that only 1 fragment is sent. */
+                fin_fragments = (ctx->obuf->ext_endp - ctx->obuf->msg_start + ERTS_DIST_FRAGMENT_SIZE-1) /
+                    ERTS_DIST_FRAGMENT_SIZE - 1;
+
+                /* Update the frag_id in the DIST_FRAG_HEADER */
+                put_int64(fin_fragments+1, ctx->obuf->extp + 1 + 1 + 8);
+
+                if (fin_fragments > 0)
+                    msg += ERTS_DIST_FRAGMENT_SIZE;
+                else
+                    msg = msg_end;
+                ctx->obuf->next = &ctx->obuf[1];
+                ctx->obuf->ext_endp = msg;
+
+                /* Loop through all fragments, updating the output buffers
+                   to be correct and also writing the DIST_FRAG_CONT header. */
+                for (i = 1; i < fin_fragments + 1; i++) {
+                    ctx->obuf[i].hopefull_flags = 0;
+                    ctx->obuf[i].extp = msg;
+                    ctx->obuf[i].ext_start = msg;
+                    if (msg + ERTS_DIST_FRAGMENT_SIZE > msg_end)
+                        ctx->obuf[i].ext_endp = msg_end;
+                    else {
+                        msg += ERTS_DIST_FRAGMENT_SIZE;
+                        ctx->obuf[i].ext_endp = msg;
+                    }
+                    ASSERT(ctx->obuf[i].ext_endp > ctx->obuf[i].extp);
+                    ctx->obuf[i].hdrp = erts_encode_ext_dist_header_fragment(
+                        &hdrp, fin_fragments - i + 1, ctx->from);
+                    ctx->obuf[i].hdr_endp = hdrp;
+                    ctx->obuf[i].next = &ctx->obuf[i+1];
+                }
+                /* If the initial fragment calculation was incorrect we free the
+                   remaining output buffers. */
+                for (; i < ctx->fragments; i++) {
+                    free_dist_obuf(&ctx->obuf[i]);
+                }
+                if (!ctx->no_trap && !ctx->no_suspend)
+                    ctx->reds -= ctx->fragments;
+                ctx->fragments = fin_fragments + 1;
+            }
+
+            ctx->phase = ERTS_DSIG_SEND_PHASE_SEND;
+
+            if (ctx->reds <= 0) {
+                retval = ERTS_DSIG_SEND_CONTINUE;
+                goto done;
+            }
+        }
+        case ERTS_DSIG_SEND_PHASE_SEND: {
+            /*
 	     * Signal encoded; now verify that the connection still exists,
 	     * and if so enqueue the signal and schedule it for send.
 	     */
-	    ctx->obuf->next = NULL;
+            DistEntry *dep = ctx->dep;
+	    int suspended = 0;
+	    int resume = 0;
+            int i;
 	    erts_de_rlock(dep);
 	    cid = dep->cid;
 	    if (dep->state == ERTS_DE_STATE_EXITING
                 || dep->state == ERTS_DE_STATE_IDLE
-                || dep->connection_id != dsdp->connection_id) {
+                || dep->connection_id != ctx->connection_id) {
 		/* Not the same connection as when we started; drop message... */
 		erts_de_runlock(dep);
-		free_dist_obuf(ctx->obuf);
+                for (i = 0; i < ctx->fragments; i++)
+                    free_dist_obuf(&ctx->obuf[i]);
+                ctx->fragments = 0;
 	    }
 	    else {
-                Sint qsize;
+                Sint qsize = erts_atomic_read_nob(&dep->qsize);
                 erts_aint32_t qflgs;
 		ErtsProcList *plp = NULL;
                 Eterm notify_proc = NIL;
-                Sint obsz = size_obuf(ctx->obuf);
+                Sint obsz;
+                int fragments;
+
+                /* Calculate how many fragments to send. This depends on
+                   the available space in the distr queue and the amount
+                   of remaining reductions. */
+                for (fragments = 0, obsz = 0;
+                     fragments < ctx->fragments &&
+                         ((ctx->reds > 0 && (qsize + obsz) < erts_dist_buf_busy_limit) ||
+                          ctx->no_trap || ctx->no_suspend);
+                     fragments++) {
+#ifdef DEBUG
+                    int reds = 100;
+#else
+                    int reds = 10;
+#endif
+                    if (!ctx->no_trap && !ctx->no_suspend)
+                        ctx->reds -= reds;
+                    obsz += size_obuf(&ctx->obuf[fragments]);
+                }
+
+                ASSERT(fragments == ctx->fragments ||
+                       (!ctx->no_trap && !ctx->no_suspend));
 
 		erts_mtx_lock(&dep->qlock);
 		qsize = erts_atomic_add_read_nob(&dep->qsize, (erts_aint_t) obsz);
@@ -1946,7 +2527,7 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
                     /* else: requester will send itself the message... */
                     qflgs &= ~ERTS_DE_QFLG_REQ_INFO;
                 }
-		if (!ctx->force_busy && (qflgs & ERTS_DE_QFLG_BUSY)) {
+		if (!ctx->no_suspend && (qflgs & ERTS_DE_QFLG_BUSY)) {
 		    erts_mtx_unlock(&dep->qlock);
 
 		    plp = erts_proclist_create(ctx->c_p);
@@ -1955,14 +2536,27 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
 		    erts_mtx_lock(&dep->qlock);
 		}
 
-		/* Enqueue obuf on dist entry */
-		if (dep->out_queue.last)
-		    dep->out_queue.last->next = ctx->obuf;
-		else
-		    dep->out_queue.first = ctx->obuf;
-		dep->out_queue.last = ctx->obuf;
+                if (fragments > 1) {
+                    if (!ctx->obuf->hdrp) {
+                        ASSERT(get_int64(ctx->obuf->extp + 10) == ctx->fragments);
+                    } else {
+                        ASSERT(get_int64(ctx->obuf->hdrp + 10) == ctx->fragments);
+                    }
+                }
+
+                if (fragments) {
+                    ctx->obuf[fragments-1].next = NULL;
+                    if (dep->out_queue.last)
+                        dep->out_queue.last->next = ctx->obuf;
+                    else
+                        dep->out_queue.first = ctx->obuf;
+                    dep->out_queue.last = &ctx->obuf[fragments-1];
 
-		if (!ctx->force_busy) {
+                    ctx->fragments -= fragments;
+                    ctx->obuf = &ctx->obuf[fragments];
+                }
+
+		if (!ctx->no_suspend) {
                     qflgs = erts_atomic32_read_nob(&dep->qflgs);
 		    if (!(qflgs & ERTS_DE_QFLG_BUSY)) {
 			if (suspended)
@@ -2009,6 +2603,13 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
 		     * erroneously scheduled when it shouldn't be.
 		     */
 		}
+                /* More fragments left to be sent, yield and re-schedule */
+                if (ctx->fragments) {
+                    retval = ERTS_DSIG_SEND_CONTINUE;
+                    if (!resume && erts_system_monitor_flags.busy_dist_port)
+                        monitor_generic(ctx->c_p, am_busy_dist_port, cid);
+                    goto done;
+                }
 	    }
 	    ctx->obuf = NULL;
 
@@ -2093,9 +2694,9 @@ static Uint
 dist_port_commandv(Port *prt, ErtsDistOutputBuf *obuf)
 {
     int fpe_was_unmasked;
-    ErlDrvSizeT size;
-    SysIOVec iov[2];
-    ErlDrvBinary* bv[2];
+    ErlDrvSizeT size = 0;
+    SysIOVec iov[3];
+    ErlDrvBinary* bv[3];
     ErlIOVec eiov;
 
     ERTS_CHK_NO_PROC_LOCKS;
@@ -2110,12 +2711,31 @@ dist_port_commandv(Port *prt, ErtsDistOutputBuf *obuf)
         eiov.vsize = 1;
     }
     else {
-        size = obuf->ext_endp - obuf->extp;
+        int i = 1;
         eiov.vsize = 2;
 
-        iov[1].iov_base = obuf->extp;
-        iov[1].iov_len = size;
-        bv[1] = Binary2ErlDrvBinary(ErtsDistOutputBuf2Binary(obuf));
+        if (obuf->hdrp) {
+            eiov.vsize = 3;
+            iov[i].iov_base = obuf->hdrp;
+            iov[i].iov_len = obuf->hdr_endp - obuf->hdrp;
+            size += iov[i].iov_len;
+            bv[i] = Binary2ErlDrvBinary(ErtsDistOutputBuf2Binary(obuf));
+#ifdef ERTS_RAW_DIST_MSG_DBG
+            erts_fprintf(dbg_file, "SEND: ");
+            bw(iov[i].iov_base, iov[i].iov_len);
+#endif
+            i++;
+
+        }
+
+        iov[i].iov_base = obuf->extp;
+        iov[i].iov_len = obuf->ext_endp - obuf->extp;
+#ifdef ERTS_RAW_DIST_MSG_DBG
+            erts_fprintf(dbg_file, "SEND: ");
+            bw(iov[i].iov_base, iov[i].iov_len);
+#endif
+        size += iov[i].iov_len;
+        bv[i] = Binary2ErlDrvBinary(ErtsDistOutputBuf2Binary(obuf));
     }
 
     eiov.size = size;
@@ -2222,6 +2842,23 @@ erts_dist_command(Port *prt, int initial_reds)
     dep->finalized_out_queue.first = NULL;
     dep->finalized_out_queue.last = NULL;
 
+#ifdef DEBUG
+    {
+        Uint sz = 0;
+        ErtsDistOutputBuf *curr = oq.first;
+        while (curr) {
+            sz += size_obuf(curr);
+            curr = curr->next;
+        }
+        curr = foq.first;
+        while (curr) {
+            sz += size_obuf(curr);
+            curr = curr->next;
+        }
+        ASSERT(sz <= erts_atomic_read_nob(&dep->qsize));
+    }
+#endif
+
     sched_flags = erts_atomic32_read_nob(&prt->sched.flags);
 
     if (reds < 0)
@@ -2235,10 +2872,6 @@ erts_dist_command(Port *prt, int initial_reds)
             size = (*send)(prt, foq.first);
             erts_atomic64_inc_nob(&dep->out);
             esdp->io.out += (Uint64) size;
-#ifdef ERTS_RAW_DIST_MSG_DBG
-            erts_fprintf(stderr, ">> ");
-            bw(foq.first->extp, size);
-#endif
 	    reds -= ERTS_PORT_REDS_DIST_CMD_DATA(size);
 	    fob = foq.first;
 	    obufsize += size_obuf(fob);
@@ -2263,7 +2896,9 @@ erts_dist_command(Port *prt, int initial_reds)
 	    ob = oq.first;
 	    ASSERT(ob);
 	    do {
+                obufsize += size_obuf(ob);
 		reds = erts_encode_ext_dist_header_finalize(ob, dep, flags, reds);
+                obufsize -= size_obuf(ob);
                 if (reds < 0)
                     break;
                 last_finalized  = ob;
@@ -2302,20 +2937,18 @@ erts_dist_command(Port *prt, int initial_reds)
 	while (oq.first && !preempt) {
 	    ErtsDistOutputBuf *fob;
 	    Uint size;
+            obufsize += size_obuf(oq.first);
             reds = erts_encode_ext_dist_header_finalize(oq.first, dep, flags, reds);
+            obufsize -= size_obuf(oq.first);
             if (reds < 0) {
                 preempt = 1;
                 break;
             }
-	    ASSERT(&oq.first->data[0] <= oq.first->extp
-		   && oq.first->extp <= oq.first->ext_endp);
+	    ASSERT(oq.first->bin->orig_bytes <= (char*)oq.first->extp
+                   && oq.first->extp <= oq.first->ext_endp);
 	    size = (*send)(prt, oq.first);
             erts_atomic64_inc_nob(&dep->out);
 	    esdp->io.out += (Uint64) size;
-#ifdef ERTS_RAW_DIST_MSG_DBG
-            erts_fprintf(stderr, ">> ");
-            bw(oq.first->extp, size);
-#endif
 	    reds -= ERTS_PORT_REDS_DIST_CMD_DATA(size);
 	    fob = oq.first;
 	    obufsize += size_obuf(fob);
@@ -2452,100 +3085,6 @@ erts_dist_command(Port *prt, int initial_reds)
     goto done;
 }
 
-#if 0
-
-int
-dist_data_finalize(Process *c_p, int reds_limit)
-{
-    int reds = 5;
-    DistEntry *dep = ;
-    ErtsDistOutputQueue oq, foq;
-    ErtsDistOutputBuf *ob;
-    int preempt;
-
-
-    erts_mtx_lock(&dep->qlock);
-    flags = dep->flags;
-    oq.first = dep->out_queue.first;
-    oq.last = dep->out_queue.last;
-    dep->out_queue.first = NULL;
-    dep->out_queue.last = NULL;
-    erts_mtx_unlock(&dep->qlock);
-
-    if (!oq.first) {
-        ASSERT(!oq.last);
-        oq.first = dep->tmp_out_queue.first;
-        oq.last = dep->tmp_out_queue.last;
-    }
-    else {
-        ErtsDistOutputBuf *f, *l;
-        ASSERT(oq.last);
-        if (dep->tmp_out_queue.last) {
-            dep->tmp_out_queue.last->next = oq.first;
-            oq.first = dep->tmp_out_queue.first;
-        }
-    }
-
-    if (!oq.first) {
-        /* Nothing to do... */
-        ASSERT(!oq.last);
-        return reds;
-    }
-
-    foq.first = dep->finalized_out_queue.first;
-    foq.last = dep->finalized_out_queue.last;
-
-    preempt = 0;
-    ob = oq.first;
-    ASSERT(ob);
-
-    do {
-        ob->extp = erts_encode_ext_dist_header_finalize(ob->extp,
-                                                        dep->cache,
-                                                        flags);
-        if (!(flags & DFLAG_DIST_HDR_ATOM_CACHE))
-            *--ob->extp = PASS_THROUGH; /* Old node; 'pass through'
-                                           needed */
-        ASSERT(&ob->data[0] <= ob->extp && ob->extp < ob->ext_endp);
-        reds += ERTS_PORT_REDS_DIST_CMD_FINALIZE;
-        preempt = reds > reds_limit;
-        if (preempt)
-            break;
-        ob = ob->next;
-    } while (ob);
-    /*
-     * At least one buffer was finalized; if we got preempted,
-     * ob points to the last buffer that we finalized.
-     */
-    if (foq.last)
-        foq.last->next = oq.first;
-    else
-        foq.first = oq.first;
-    if (!preempt) {
-        /* All buffers finalized */
-        foq.last = oq.last;
-        oq.first = oq.last = NULL;
-    }
-    else {
-        /* Not all buffers finalized; split oq. */
-        foq.last = ob;
-        oq.first = ob->next;
-        if (oq.first)
-            ob->next = NULL;
-        else
-            oq.last = NULL;
-    }
-
-    dep->finalized_out_queue.first = foq.first;
-    dep->finalized_out_queue.last = foq.last;
-    dep->tmp_out_queue.first = oq.first;
-    dep->tmp_out_queue.last = oq.last;
-
-    return reds;
-}
-
-#endif
-
 BIF_RETTYPE
 dist_ctrl_get_data_notification_1(BIF_ALIST_1)
 {
@@ -2614,6 +3153,7 @@ dist_ctrl_put_data_2(BIF_ALIST_2)
     ErlDrvSizeT size;
     Eterm input_handler;
     Uint32 conn_id;
+    Binary *bin = NULL;
 
     if (is_binary(BIF_ARG_2))
         size = binary_size(BIF_ARG_2);
@@ -2639,13 +3179,27 @@ dist_ctrl_put_data_2(BIF_ALIST_2)
     if (size != 0) {
         byte *data, *temp_alloc = NULL;
 
-        data = (byte *) erts_get_aligned_binary_bytes(BIF_ARG_2, &temp_alloc);
+        if (binary_bitoffset(BIF_ARG_2))
+            data = (byte *) erts_get_aligned_binary_bytes(BIF_ARG_2, &temp_alloc);
+        else {
+            Eterm real_bin;
+            ProcBin *proc_bin;
+            Uint offset, bitoffs, bitsize;
+
+            ERTS_GET_REAL_BIN(BIF_ARG_2, real_bin, offset, bitoffs, bitsize);
+            ASSERT(bitoffs == 0);
+            data = binary_bytes(real_bin) + offset;
+            proc_bin = (ProcBin *)binary_val(real_bin);
+            if (proc_bin->thing_word == HEADER_PROC_BIN)
+                bin = proc_bin->val;
+        }
+
         if (!data)
             BIF_ERROR(BIF_P, BADARG);
 
         erts_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
 
-        (void) erts_net_message(NULL, dep, conn_id, NULL, 0, data, size);
+        (void) erts_net_message(NULL, dep, conn_id, NULL, 0, bin, data, size);
         /*
          * We ignore any decode failures. On fatal failures the
          * connection will be taken down by killing the
@@ -2664,6 +3218,86 @@ dist_ctrl_put_data_2(BIF_ALIST_2)
 }
 
 BIF_RETTYPE
+dist_ctrl_set_opt_3(BIF_ALIST_3)
+{
+    DistEntry *dep = ERTS_PROC_GET_DIST_ENTRY(BIF_P);
+    Uint32 conn_id;
+    BIF_RETTYPE ret;
+
+    if (!dep)
+        BIF_ERROR(BIF_P, EXC_NOTSUP);
+
+    if (erts_dhandle_to_dist_entry(BIF_ARG_1, &conn_id) != dep)
+        BIF_ERROR(BIF_P, BADARG);
+
+    erts_de_rlock(dep);
+
+    if (dep->connection_id != conn_id)
+        ERTS_BIF_PREP_ERROR(ret, BIF_P, BADARG);
+    else {
+
+        switch (BIF_ARG_2) {
+        case am_get_size:
+            ERTS_BIF_PREP_RET(ret, (dep->opts & ERTS_DIST_CTRL_OPT_GET_SIZE
+                                    ? am_true
+                                    : am_false));
+            if (BIF_ARG_3 == am_true) 
+                dep->opts |= ERTS_DIST_CTRL_OPT_GET_SIZE;
+            else if (BIF_ARG_3 == am_false)
+                dep->opts &= ~ERTS_DIST_CTRL_OPT_GET_SIZE;
+            else
+                ERTS_BIF_PREP_ERROR(ret, BIF_P, BADARG);
+            break;
+        default:
+            ERTS_BIF_PREP_ERROR(ret, BIF_P, BADARG);
+            break;
+        }
+
+    }
+
+    erts_de_runlock(dep);
+
+    return ret;
+}
+
+BIF_RETTYPE
+dist_ctrl_get_opt_2(BIF_ALIST_2)
+{
+    DistEntry *dep = ERTS_PROC_GET_DIST_ENTRY(BIF_P);
+    Uint32 conn_id;
+    BIF_RETTYPE ret;
+
+    if (!dep)
+        BIF_ERROR(BIF_P, EXC_NOTSUP);
+
+    if (erts_dhandle_to_dist_entry(BIF_ARG_1, &conn_id) != dep)
+        BIF_ERROR(BIF_P, BADARG);
+
+    erts_de_rlock(dep);
+
+    if (dep->connection_id != conn_id)
+        ERTS_BIF_PREP_ERROR(ret, BIF_P, BADARG);
+    else {
+
+        switch (BIF_ARG_2) {
+        case am_get_size:
+            ERTS_BIF_PREP_RET(ret, (dep->opts & ERTS_DIST_CTRL_OPT_GET_SIZE
+                                    ? am_true
+                                    : am_false));
+            break;
+        default:
+            ERTS_BIF_PREP_ERROR(ret, BIF_P, BADARG);
+            break;
+        }
+
+    }
+
+    erts_de_runlock(dep);
+
+    return ret;
+}
+    
+BIF_RETTYPE
 dist_get_stat_1(BIF_ALIST_1)
 {
     Sint64 read, write, pend;
@@ -2696,7 +3330,7 @@ dist_get_stat_1(BIF_ALIST_1)
                              am_ok,
                              erts_bld_sint64(hpp, szp, read),
                              erts_bld_sint64(hpp, szp, write),
-                             pend ? am_true : am_false);
+                             erts_bld_sint64(hpp, szp, pend));
         if (hpp)
             break;
         hp = HAlloc(BIF_P, sz);
@@ -2738,12 +3372,13 @@ dist_ctrl_get_data_1(BIF_ALIST_1)
 {
     DistEntry *dep = ERTS_PROC_GET_DIST_ENTRY(BIF_P);
     const Sint initial_reds = ERTS_BIF_REDS_LEFT(BIF_P);
-    Sint reds = initial_reds;
+    Sint reds = initial_reds, obufsize = 0;
     ErtsDistOutputBuf *obuf;
-    Eterm *hp;
+    Eterm *hp, res;
     ProcBin *pb;
     erts_aint_t qsize;
-    Uint32 conn_id;
+    Uint32 conn_id, get_size;
+    Uint hsz = 0, bin_sz;
 
     if (!dep)
         BIF_ERROR(BIF_P, EXC_NOTSUP);
@@ -2795,9 +3430,13 @@ dist_ctrl_get_data_1(BIF_ALIST_1)
         }
 
         obuf = dep->tmp_out_queue.first;
+        obufsize += size_obuf(obuf);
         reds = erts_encode_ext_dist_header_finalize(obuf, dep, dep->flags, reds);
+        obufsize -= size_obuf(obuf);
         if (reds < 0) {
             erts_de_runlock(dep);
+            if (obufsize)
+                erts_atomic_add_nob(&dep->qsize, (erts_aint_t) -obufsize);
             ERTS_BIF_YIELD1(bif_export[BIF_dist_ctrl_get_data_1],
                             BIF_P, BIF_ARG_1);
         }
@@ -2811,17 +3450,60 @@ dist_ctrl_get_data_1(BIF_ALIST_1)
 
     erts_de_runlock(dep);
 
-    hp =  HAlloc(BIF_P, PROC_BIN_SIZE);
-    pb = (ProcBin *) (char *) hp;
-    pb->thing_word = HEADER_PROC_BIN;
-    pb->size = obuf->ext_endp - obuf->extp;
-    pb->next = MSO(BIF_P).first;
-    MSO(BIF_P).first = (struct erl_off_heap_header*) pb;
-    pb->val = ErtsDistOutputBuf2Binary(obuf);
-    pb->bytes = (byte*) obuf->extp;
-    pb->flags = 0;
-
-    qsize = erts_atomic_add_read_nob(&dep->qsize, -size_obuf(obuf));
+    bin_sz = obuf->ext_endp - obuf->extp + obuf->hdr_endp - obuf->hdrp;
+
+    get_size = dep->opts & ERTS_DIST_CTRL_OPT_GET_SIZE;
+    if (get_size) {
+        hsz += 3; /* 2 tuple */
+        if (!IS_USMALL(0, bin_sz))
+            hsz += BIG_UINT_HEAP_SIZE;
+    }
+
+    if (!obuf->hdrp) {
+        hp =  HAlloc(BIF_P, PROC_BIN_SIZE + hsz);
+        pb = (ProcBin *) (char *) hp;
+        pb->thing_word = HEADER_PROC_BIN;
+        pb->size = obuf->ext_endp - obuf->extp;
+        pb->next = MSO(BIF_P).first;
+        MSO(BIF_P).first = (struct erl_off_heap_header*) pb;
+        pb->val = ErtsDistOutputBuf2Binary(obuf);
+        pb->bytes = (byte*) obuf->extp;
+        pb->flags = 0;
+        res = make_binary(pb);
+        hp += PROC_BIN_SIZE;
+    } else {
+        hp =  HAlloc(BIF_P, PROC_BIN_SIZE * 2 + 4 + hsz);
+        pb = (ProcBin *) (char *) hp;
+        pb->thing_word = HEADER_PROC_BIN;
+        pb->size = obuf->ext_endp - obuf->extp;
+        pb->next = MSO(BIF_P).first;
+        MSO(BIF_P).first = (struct erl_off_heap_header*) pb;
+        pb->val = ErtsDistOutputBuf2Binary(obuf);
+        pb->bytes = (byte*) obuf->extp;
+        pb->flags = 0;
+        hp += PROC_BIN_SIZE;
+
+        res = CONS(hp, make_binary(pb), NIL);
+        hp += 2;
+
+        pb = (ProcBin *) (char *) hp;
+        pb->thing_word = HEADER_PROC_BIN;
+        pb->size = obuf->hdr_endp - obuf->hdrp;
+        pb->next = MSO(BIF_P).first;
+        MSO(BIF_P).first = (struct erl_off_heap_header*) pb;
+        pb->val = ErtsDistOutputBuf2Binary(obuf);
+        erts_refc_inc(&pb->val->intern.refc, 1);
+        pb->bytes = (byte*) obuf->hdrp;
+        pb->flags = 0;
+        hp += PROC_BIN_SIZE;
+        res = CONS(hp, make_binary(pb), res);
+        hp += 2;
+    }
+
+    obufsize += size_obuf(obuf);
+
+    qsize = erts_atomic_add_read_nob(&dep->qsize, (erts_aint_t) -obufsize);
+
     ASSERT(qsize >= 0);
 
     if (qsize < erts_dist_buf_busy_limit/2
@@ -2836,7 +3518,18 @@ dist_ctrl_get_data_1(BIF_ALIST_1)
         }
     }
 
-    BIF_RET2(make_binary(pb), (initial_reds - reds));
+    if (get_size) {
+        Eterm sz_term;
+        if (IS_USMALL(0, bin_sz))
+            sz_term = make_small(bin_sz);
+        else {
+            sz_term = uint_to_big(bin_sz, hp);
+            hp += BIG_UINT_HEAP_SIZE;
+        }
+        res = TUPLE2(hp, sz_term, res);
+    }
+
+    BIF_RET2(res, (initial_reds - reds));
 }
 
 void
@@ -2879,6 +3572,10 @@ static void kill_connection(DistEntry *dep)
 void
 erts_kill_dist_connection(DistEntry *dep, Uint32 conn_id)
 {
+#ifdef ERTS_DIST_MSG_DBG
+    erts_fprintf(dbg_file, "INTR: kill dist conn to %T:%u\n",
+                 dep->sysname, conn_id);
+#endif
     erts_de_rwlock(dep);
     if (conn_id == dep->connection_id
         && dep->state == ERTS_DE_STATE_CONNECTED) {
@@ -2893,7 +3590,7 @@ struct print_to_data {
     void *arg;
 };
 
-static void doit_print_monitor_info(ErtsMonitor *mon, void *vptdp)
+static int doit_print_monitor_info(ErtsMonitor *mon, void *vptdp, Sint reds)
 {
     fmtfn_t to = ((struct print_to_data *) vptdp)->to;
     void *arg = ((struct print_to_data *) vptdp)->arg;
@@ -2916,6 +3613,7 @@ static void doit_print_monitor_info(ErtsMonitor *mon, void *vptdp)
         else
 	    erts_print(to, arg, "%T\n", mdep->md.origin.other.item);
     }
+    return 1;
 }    
 
 static void print_monitor_info(fmtfn_t to, void *arg, DistEntry *dep)
@@ -2931,12 +3629,13 @@ static void print_monitor_info(fmtfn_t to, void *arg, DistEntry *dep)
     }
 }
 
-static void doit_print_link_info(ErtsLink *lnk, void *vptdp)
+static int doit_print_link_info(ErtsLink *lnk, void *vptdp, Sint reds)
 {
     struct print_to_data *ptdp = vptdp;
     ErtsLink *lnk2 = erts_link_to_other(lnk, NULL);
     erts_print(ptdp->to, ptdp->arg, "Remote link: %T %T\n",
 	       lnk2->other.item, lnk->other.item);
+    return 1;
 }
 
 static void print_link_info(fmtfn_t to, void *arg, DistEntry *dep)
@@ -3538,8 +4237,9 @@ Sint erts_abort_connection_rwunlock(DistEntry* dep)
         erts_set_dist_entry_not_connected(dep);
 	erts_de_rwunlock(dep);
 
-        schedule_con_monitor_link_cleanup(mld, THE_NON_VALUE,
-                                          THE_NON_VALUE, THE_NON_VALUE);
+        schedule_con_monitor_link_seq_cleanup(
+            mld, NULL, THE_NON_VALUE,
+            THE_NON_VALUE, THE_NON_VALUE);
 
         if (resume_procs) {
             int resumed = erts_resume_processes(resume_procs);
@@ -3845,16 +4545,16 @@ monitor_node(Process* p, Eterm Node, Eterm Bool, Eterm Options)
     }
 
     case am_true: {
-        ErtsDSigData dsd;
-        dsd.node = Node;
+        ErtsDSigSendContext ctx;
+        ctx.node = Node;
 
         dep = erts_find_or_insert_dist_entry(Node);
         if (dep == erts_this_dist_entry)
             break;
 
-        switch (erts_dsig_prepare(&dsd, dep, p,
+        switch (erts_dsig_prepare(&ctx, dep, p,
                                   ERTS_PROC_LOCK_MAIN,
-                                  ERTS_DSP_RLOCK, 0, async_connect)) {
+                                  ERTS_DSP_RLOCK, 0, 0, async_connect)) {
         case ERTS_DSIG_PREP_NOT_ALIVE:
 	case ERTS_DSIG_PREP_NOT_CONNECTED:
 	    /* Trap to either send 'nodedown' or do passive connection attempt */
@@ -3881,28 +4581,22 @@ monitor_node(Process* p, Eterm Node, Eterm Bool, Eterm Options)
                                                   Node);
             mdep = (ErtsMonitorDataExtended *) erts_monitor_to_data(mon);
             if (created) {
-#ifdef DEBUG
                 int inserted =
-#endif
                     erts_monitor_dist_insert(&mdep->md.target, dep->mld);
-                ASSERT(inserted);
+                ASSERT(inserted); (void)inserted;
                 ASSERT(mdep->dist->connection_id == dep->connection_id);
             }
             else if (mdep->dist->connection_id != dep->connection_id) {
                 ErtsMonitorDataExtended *mdep2;
                 ErtsMonitor *mon2;
-#ifdef DEBUG
                 int inserted;
-#endif
                 mdep2 = ((ErtsMonitorDataExtended *)
                          erts_monitor_create(ERTS_MON_TYPE_NODE, NIL,
                                              p->common.id, Node, NIL));
                 mon2 = &mdep2->md.origin;
-#ifdef DEBUG
                 inserted =
-#endif
                     erts_monitor_dist_insert(&mdep->md.target, dep->mld);
-                ASSERT(inserted);
+                ASSERT(inserted); (void)inserted;
                 ASSERT(mdep2->dist->connection_id == dep->connection_id);
 
                 mdep2->uptr.node_monitors = mdep->uptr.node_monitors;
@@ -4158,8 +4852,8 @@ typedef struct {
     Uint i;
 } ErtsNodesMonitorContext;
 
-static void
-save_nodes_monitor(ErtsMonitor *mon, void *vctxt)
+static int
+save_nodes_monitor(ErtsMonitor *mon, void *vctxt, Sint reds)
 {
     ErtsNodesMonitorContext *ctxt = vctxt;
     ErtsMonitorData *mdp = erts_monitor_to_data(mon);
@@ -4171,6 +4865,7 @@ save_nodes_monitor(ErtsMonitor *mon, void *vctxt)
     ctxt->nmdp[ctxt->i].options = mdp->origin.other.item;
 
     ctxt->i++;
+    return 1;
 }
 
 static void
@@ -4303,8 +4998,8 @@ typedef struct {
 } ErtsNodesMonitorInfoContext;
 
 
-static void
-nodes_monitor_info(ErtsMonitor *mon, void *vctxt)
+static int
+nodes_monitor_info(ErtsMonitor *mon, void *vctxt, Sint reds)
 {
     ErtsMonitorDataExtended *mdep;
     ErtsNodesMonitorInfoContext *ctxt = vctxt;
@@ -4351,6 +5046,7 @@ nodes_monitor_info(ErtsMonitor *mon, void *vctxt)
     ctxt->hpp = hpp;
     ctxt->szp = szp;
     ctxt->res = res;
+    return 1;
 }
 
 Eterm
@@ -4405,3 +5101,22 @@ erts_processes_monitoring_nodes(Process *c_p)
 
     return ctxt.res;
 }
+
+static void
+print_suspended_on_de(fmtfn_t to, void *to_arg, DistEntry *dep)
+{
+    for (; dep; dep = dep->next) {
+        ErtsProcList *curr = erts_proclist_peek_first(dep->suspended);
+        while (curr) {
+            if (!is_internal_pid(curr->u.pid))
+                print_process_info(to, to_arg, curr->u.p, 0);
+            curr = erts_proclist_peek_next(dep->suspended, curr);
+        }
+    }
+}
+
+void
+erts_dist_print_procs_suspended_on_de(fmtfn_t to, void *to_arg) {
+    print_suspended_on_de(to, to_arg, erts_hidden_dist_entries);
+    print_suspended_on_de(to, to_arg, erts_visible_dist_entries);
+}
diff --git a/erts/emulator/beam/dist.h b/erts/emulator/beam/dist.h
index d4d7874a70..a33fb7efcf 100644
--- a/erts/emulator/beam/dist.h
+++ b/erts/emulator/beam/dist.h
@@ -47,6 +47,8 @@
 #define DFLAG_SEND_SENDER         0x80000
 #define DFLAG_BIG_SEQTRACE_LABELS 0x100000
 #define DFLAG_NO_MAGIC            0x200000 /* internal for pending connection */
+#define DFLAG_EXIT_PAYLOAD        0x400000
+#define DFLAG_FRAGMENTS           0x800000
 
 /* Mandatory flags for distribution */
 #define DFLAG_DIST_MANDATORY (DFLAG_EXTENDED_REFERENCES         \
@@ -75,7 +77,9 @@
                             | DFLAG_MAP_TAG                   \
                             | DFLAG_BIG_CREATION              \
                             | DFLAG_SEND_SENDER               \
-                            | DFLAG_BIG_SEQTRACE_LABELS)
+                            | DFLAG_BIG_SEQTRACE_LABELS       \
+                            | DFLAG_EXIT_PAYLOAD              \
+                            | DFLAG_FRAGMENTS)
 
 /* Flags addable by local distr implementations */
 #define DFLAG_DIST_ADDABLE    DFLAG_DIST_DEFAULT
@@ -99,26 +103,35 @@
                                | DFLAG_BIG_CREATION)
 
 /* opcodes used in distribution messages */
-#define DOP_LINK		1
-#define DOP_SEND		2
-#define DOP_EXIT		3
-#define DOP_UNLINK		4
+enum dop {
+    DOP_LINK                = 1,
+    DOP_SEND                = 2,
+    DOP_EXIT                = 3,
+    DOP_UNLINK              = 4,
 /* Ancient DOP_NODE_LINK (5) was here, can be reused */
-#define DOP_REG_SEND		6
-#define DOP_GROUP_LEADER	7
-#define DOP_EXIT2		8
-
-#define DOP_SEND_TT		12
-#define DOP_EXIT_TT		13
-#define DOP_REG_SEND_TT		16
-#define DOP_EXIT2_TT		18
-
-#define DOP_MONITOR_P		19
-#define DOP_DEMONITOR_P		20
-#define DOP_MONITOR_P_EXIT	21
-
-#define DOP_SEND_SENDER         22
-#define DOP_SEND_SENDER_TT      23
+    DOP_REG_SEND            = 6,
+    DOP_GROUP_LEADER        = 7,
+    DOP_EXIT2               = 8,
+
+    DOP_SEND_TT             = 12,
+    DOP_EXIT_TT             = 13,
+    DOP_REG_SEND_TT         = 16,
+    DOP_EXIT2_TT            = 18,
+
+    DOP_MONITOR_P           = 19,
+    DOP_DEMONITOR_P         = 20,
+    DOP_MONITOR_P_EXIT      = 21,
+
+    DOP_SEND_SENDER         = 22,
+    DOP_SEND_SENDER_TT      = 23,
+
+    /* These are used when DFLAG_EXIT_PAYLOAD is detected */
+    DOP_PAYLOAD_EXIT           = 24,
+    DOP_PAYLOAD_EXIT_TT        = 25,
+    DOP_PAYLOAD_EXIT2          = 26,
+    DOP_PAYLOAD_EXIT2_TT       = 27,
+    DOP_PAYLOAD_MONITOR_P_EXIT = 28
+};
 
 /* distribution trap functions */
 extern Export* dmonitor_node_trap;
@@ -129,15 +142,15 @@ typedef enum {
 } ErtsDSigPrepLock;
 
 
-typedef struct {
-    Process *proc;
-    DistEntry *dep;
-    Eterm node;   /* used if dep == NULL */
-    Eterm cid;
-    Eterm connection_id;
-    int no_suspend;
-    Uint32 flags;
-} ErtsDSigData;
+/* Must be larger or equal to 16 */
+#ifdef DEBUG
+#define ERTS_DIST_FRAGMENT_SIZE 16
+#else
+/* This should be made configurable */
+#define ERTS_DIST_FRAGMENT_SIZE (64 * 1024)
+#endif
+
+#define ERTS_DIST_FRAGMENT_HEADER_SIZE (1 + 1 + 8 + 8) /* magic, header, seq id, frag id*/
 
 #define ERTS_DE_BUSY_LIMIT (1024*1024)
 extern int erts_dist_buf_busy_limit;
@@ -159,123 +172,8 @@ extern int erts_is_alive;
 /* Pending connection; signals can be enqueued */
 #define ERTS_DSIG_PREP_PENDING	        4
 
-ERTS_GLB_INLINE int erts_dsig_prepare(ErtsDSigData *,
-				      DistEntry*,
-				      Process *,
-                                      ErtsProcLocks,
-				      ErtsDSigPrepLock,
-				      int,
-				      int);
-
-ERTS_GLB_INLINE
-void erts_schedule_dist_command(Port *, DistEntry *);
-
-int erts_auto_connect(DistEntry* dep, Process *proc, ErtsProcLocks proc_locks);
-
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-ERTS_GLB_INLINE int 
-erts_dsig_prepare(ErtsDSigData *dsdp,
-		  DistEntry *dep,
-		  Process *proc,
-                  ErtsProcLocks proc_locks,
-		  ErtsDSigPrepLock dspl,
-		  int no_suspend,
-		  int connect)
-{
-    int res;
-
-    if (!erts_is_alive)
-	return ERTS_DSIG_PREP_NOT_ALIVE;
-    if (!dep) {
-        ASSERT(!connect);
-        return ERTS_DSIG_PREP_NOT_CONNECTED;
-    }
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
-    if (connect) {
-        erts_proc_lc_might_unlock(proc, proc_locks);
-    }
-#endif
-
-retry:
-    erts_de_rlock(dep);
-
-    if (dep->state == ERTS_DE_STATE_CONNECTED) {
-	res = ERTS_DSIG_PREP_CONNECTED;
-    }
-    else if (dep->state == ERTS_DE_STATE_PENDING) {
-	res = ERTS_DSIG_PREP_PENDING;
-    }
-    else if (dep->state == ERTS_DE_STATE_EXITING) {
-	res = ERTS_DSIG_PREP_NOT_CONNECTED;
-	goto fail;
-    }
-    else if (connect) {
-        ASSERT(dep->state == ERTS_DE_STATE_IDLE);
-        erts_de_runlock(dep);
-        if (!erts_auto_connect(dep, proc, proc_locks)) {
-            return ERTS_DSIG_PREP_NOT_ALIVE;
-        }
-	goto retry;
-    }
-    else {
-        ASSERT(dep->state == ERTS_DE_STATE_IDLE);
-	res = ERTS_DSIG_PREP_NOT_CONNECTED;
-	goto fail;
-    }
-
-    if (no_suspend) {
-	if (erts_atomic32_read_acqb(&dep->qflgs) & ERTS_DE_QFLG_BUSY) {
-	    res = ERTS_DSIG_PREP_WOULD_SUSPEND;
-	    goto fail;
-	}
-    }
-    dsdp->proc = proc;
-    dsdp->dep = dep;
-    dsdp->cid = dep->cid;
-    dsdp->connection_id = dep->connection_id;
-    dsdp->no_suspend = no_suspend;
-    dsdp->flags = dep->flags;
-    if (dspl == ERTS_DSP_NO_LOCK)
-	erts_de_runlock(dep);
-    return res;
-
- fail:
-    erts_de_runlock(dep);
-    return res;
-}
-
-ERTS_GLB_INLINE
-void erts_schedule_dist_command(Port *prt, DistEntry *dist_entry)
-{
-    DistEntry *dep;
-    Eterm id;
-
-    if (prt) {
-	ERTS_LC_ASSERT(erts_lc_is_port_locked(prt));
-	ASSERT((erts_atomic32_read_nob(&prt->state)
-		& ERTS_PORT_SFLGS_DEAD) == 0);
-
-        dep = (DistEntry*) erts_prtsd_get(prt, ERTS_PRTSD_DIST_ENTRY);
-        ASSERT(dep);
-	id = prt->common.id;
-    }
-    else {
-	ASSERT(dist_entry);
-	ERTS_LC_ASSERT(erts_lc_rwmtx_is_rlocked(&dist_entry->rwmtx)
-			   || erts_lc_rwmtx_is_rwlocked(&dist_entry->rwmtx));
-	ASSERT(is_internal_port(dist_entry->cid));
-
- 	dep = dist_entry;
-	id = dep->cid;
-    }
-
-    if (!erts_atomic_xchg_mb(&dep->dist_cmd_scheduled, 1))
-	erts_port_task_schedule(id, &dep->dist_cmd, ERTS_PORT_TASK_DIST_CMD);
-}
-
-#endif
+/* dist_ctrl_{g,s}et_option/2 */
+#define ERTS_DIST_CTRL_OPT_GET_SIZE     ((Uint32) (1 << 0))
 
 #ifdef DEBUG
 #define ERTS_DBG_CHK_NO_DIST_LNK(D, R, L) \
@@ -336,41 +234,57 @@ enum erts_dsig_send_phase {
     ERTS_DSIG_SEND_PHASE_MSG_SIZE,
     ERTS_DSIG_SEND_PHASE_ALLOC,
     ERTS_DSIG_SEND_PHASE_MSG_ENCODE,
-    ERTS_DSIG_SEND_PHASE_FIN
+    ERTS_DSIG_SEND_PHASE_FIN,
+    ERTS_DSIG_SEND_PHASE_SEND
 };
 
-struct erts_dsig_send_context {
-    enum erts_dsig_send_phase phase;
-    Sint reds;
+typedef struct erts_dsig_send_context {
+    int connect;
+    int no_suspend;
+    int no_trap;
 
     Eterm ctl;
     Eterm msg;
-    int force_busy;
+    Eterm from;
+    Eterm ctl_heap[6];
+    Eterm return_term;
+
+    DistEntry *dep;
+    Eterm node;   /* used if dep == NULL */
+    Eterm cid;
+    Eterm connection_id;
+    int deref_dep;
+
+    enum erts_dsig_send_phase phase;
+    Sint reds;
+
     Uint32 max_finalize_prepend;
     Uint data_size, dhdr_ext_size;
     ErtsAtomCacheMap *acmp;
     ErtsDistOutputBuf *obuf;
+    Uint fragments;
     Uint32 flags;
     Process *c_p;
     union {
 	TTBSizeContext sc;
 	TTBEncodeContext ec;
     }u;
-};
 
-typedef struct {
-    int suspend;
-    int connect;
+} ErtsDSigSendContext;
 
-    Eterm ctl_heap[6];
-    ErtsDSigData dsd;
-    DistEntry *dep;
-    int deref_dep;
-    struct erts_dsig_send_context dss;
+typedef struct dist_sequences DistSeqNode;
 
-    Eterm return_term;
-}ErtsSendContext;
+struct dist_sequences {
+    ErlHeapFragment hfrag;
+    struct dist_sequences *parent;
+    struct dist_sequences *left;
+    struct dist_sequences *right;
+    char is_red;
 
+    Uint64 seq_id;
+    int cnt;
+    Sint ctl_len;
+};
 
 /*
  * erts_dsig_send_* return values.
@@ -378,22 +292,23 @@ typedef struct {
 #define ERTS_DSIG_SEND_OK	0
 #define ERTS_DSIG_SEND_YIELD	1
 #define ERTS_DSIG_SEND_CONTINUE 2
-
-extern int erts_dsig_send_link(ErtsDSigData *, Eterm, Eterm);
-extern int erts_dsig_send_msg(Eterm, Eterm, ErtsSendContext*);
-extern int erts_dsig_send_exit_tt(ErtsDSigData *, Eterm, Eterm, Eterm, Eterm);
-extern int erts_dsig_send_unlink(ErtsDSigData *, Eterm, Eterm);
-extern int erts_dsig_send_reg_msg(Eterm, Eterm, ErtsSendContext*);
-extern int erts_dsig_send_group_leader(ErtsDSigData *, Eterm, Eterm);
-extern int erts_dsig_send_exit(ErtsDSigData *, Eterm, Eterm, Eterm);
-extern int erts_dsig_send_exit2(ErtsDSigData *, Eterm, Eterm, Eterm);
-extern int erts_dsig_send_demonitor(ErtsDSigData *, Eterm, Eterm, Eterm, int);
-extern int erts_dsig_send_monitor(ErtsDSigData *, Eterm, Eterm, Eterm);
-extern int erts_dsig_send_m_exit(ErtsDSigData *, Eterm, Eterm, Eterm, Eterm);
-
-extern int erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx);
+#define ERTS_DSIG_SEND_TOO_LRG  3
+
+extern int erts_dsig_send_msg(ErtsDSigSendContext*, Eterm, Eterm);
+extern int erts_dsig_send_reg_msg(ErtsDSigSendContext*, Eterm, Eterm);
+extern int erts_dsig_send_link(ErtsDSigSendContext *, Eterm, Eterm);
+extern int erts_dsig_send_exit_tt(ErtsDSigSendContext *, Eterm, Eterm, Eterm, Eterm);
+extern int erts_dsig_send_unlink(ErtsDSigSendContext *, Eterm, Eterm);
+extern int erts_dsig_send_group_leader(ErtsDSigSendContext *, Eterm, Eterm);
+extern int erts_dsig_send_exit(ErtsDSigSendContext *, Eterm, Eterm, Eterm);
+extern int erts_dsig_send_exit2(ErtsDSigSendContext *, Eterm, Eterm, Eterm);
+extern int erts_dsig_send_demonitor(ErtsDSigSendContext *, Eterm, Eterm, Eterm);
+extern int erts_dsig_send_monitor(ErtsDSigSendContext *, Eterm, Eterm, Eterm);
+extern int erts_dsig_send_m_exit(ErtsDSigSendContext *, Eterm, Eterm, Eterm, Eterm);
+
+extern int erts_dsig_send(ErtsDSigSendContext *dsdp);
 extern int erts_dsend_context_dtor(Binary*);
-extern Eterm erts_dsend_export_trap_context(Process* p, ErtsSendContext* ctx);
+extern Eterm erts_dsend_export_trap_context(Process* p, ErtsDSigSendContext* ctx);
 
 extern int erts_dist_command(Port *prt, int reds);
 extern void erts_dist_port_not_busy(Port *prt);
@@ -403,5 +318,19 @@ extern Uint erts_dist_cache_size(void);
 
 extern Sint erts_abort_connection_rwunlock(DistEntry *dep);
 
+extern void erts_debug_dist_seq_tree_foreach(
+    DistEntry *dep,
+    int (*func)(DistSeqNode *, void*, Sint), void *args);
+
+extern int erts_dsig_prepare(ErtsDSigSendContext *,
+                             DistEntry*,
+                             Process *,
+                             ErtsProcLocks,
+                             ErtsDSigPrepLock,
+                             int,
+                             int,
+                             int);
 
+void erts_dist_print_procs_suspended_on_de(fmtfn_t to, void *to_arg);
+int erts_auto_connect(DistEntry* dep, Process *proc, ErtsProcLocks proc_locks);
 #endif
diff --git a/erts/emulator/beam/erl_afit_alloc.c b/erts/emulator/beam/erl_afit_alloc.c
index 38289ea78a..f07137c883 100644
--- a/erts/emulator/beam/erl_afit_alloc.c
+++ b/erts/emulator/beam/erl_afit_alloc.c
@@ -102,6 +102,8 @@ erts_afalc_start(AFAllctr_t *afallctr,
     allctr->add_mbc                     = NULL;
     allctr->remove_mbc                  = NULL;
     allctr->largest_fblk_in_mbc         = NULL;
+    allctr->first_fblk_in_mbc           = NULL;
+    allctr->next_fblk_in_mbc            = NULL;
     allctr->init_atoms			= init_atoms;
 
 #ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
diff --git a/erts/emulator/beam/erl_alloc.c b/erts/emulator/beam/erl_alloc.c
index 9e36d5e0d1..b9f0334172 100644
--- a/erts/emulator/beam/erl_alloc.c
+++ b/erts/emulator/beam/erl_alloc.c
@@ -64,9 +64,6 @@
 #  error "Too many schedulers; cannot create that many pref alloc instances"
 #endif
 
-#define ERTS_ALC_FIX_TYPE_IX(T) \
-  (ERTS_ALC_T2N((T)) - ERTS_ALC_N_MIN_A_FIXED_SIZE)
-
 #define ERTS_ALC_DEFAULT_MAX_THR_PREF ERTS_MAX_NO_OF_SCHEDULERS
 
 #if defined(SMALL_MEMORY) || defined(PURIFY) || defined(VALGRIND)
@@ -156,20 +153,13 @@ ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(aireq,
 
 ErtsAlcType_t erts_fix_core_allocator_ix;
 
-enum allctr_type {
-    GOODFIT,
-    BESTFIT,
-    AFIT,
-    FIRSTFIT
-};
-
 struct au_init {
     int enable;
     int thr_spec;
     int disable_allowed;
     int thr_spec_allowed;
     int carrier_migration_allowed;
-    enum allctr_type	atype;
+    ErtsAlcStrat_t	astrat;
     struct {
 	AllctrInit_t	util;
 	GFAllctrInit_t	gf;
@@ -219,7 +209,9 @@ typedef struct {
     struct au_init test_alloc;
 } erts_alc_hndl_args_init_t;
 
-#define ERTS_AU_INIT__ {0, 0, 1, 1, 1, GOODFIT, DEFAULT_ALLCTR_INIT, {1,1,1,1}}
+#define ERTS_AU_INIT__ {0, 0, 1, 1, 1, \
+                        ERTS_ALC_S_GOODFIT, DEFAULT_ALLCTR_INIT, \
+                        {1,1,1,1}}
 
 #define SET_DEFAULT_ALLOC_OPTS(IP)					\
 do {									\
@@ -233,7 +225,7 @@ set_default_sl_alloc_opts(struct au_init *ip)
     SET_DEFAULT_ALLOC_OPTS(ip);
     ip->enable			= AU_ALLOC_DEFAULT_ENABLE(1);
     ip->thr_spec		= 1;
-    ip->atype			= GOODFIT;
+    ip->astrat			= ERTS_ALC_S_GOODFIT;
     ip->init.util.name_prefix	= "sl_";
     ip->init.util.alloc_no	= ERTS_ALC_A_SHORT_LIVED;
 #ifndef SMALL_MEMORY
@@ -252,7 +244,7 @@ set_default_std_alloc_opts(struct au_init *ip)
     SET_DEFAULT_ALLOC_OPTS(ip);
     ip->enable			= AU_ALLOC_DEFAULT_ENABLE(1);
     ip->thr_spec		= 1;
-    ip->atype			= BESTFIT;
+    ip->astrat			= ERTS_ALC_S_BESTFIT;
     ip->init.util.name_prefix	= "std_";
     ip->init.util.alloc_no	= ERTS_ALC_A_STANDARD;
 #ifndef SMALL_MEMORY
@@ -270,7 +262,7 @@ set_default_ll_alloc_opts(struct au_init *ip)
     SET_DEFAULT_ALLOC_OPTS(ip);
     ip->enable			= AU_ALLOC_DEFAULT_ENABLE(1);
     ip->thr_spec		= 0;
-    ip->atype			= BESTFIT;
+    ip->astrat			= ERTS_ALC_S_BESTFIT;
     ip->init.bf.ao		= 1;
     ip->init.util.ramv		= 0;
     ip->init.util.mmsbc		= 0;
@@ -299,7 +291,7 @@ set_default_literal_alloc_opts(struct au_init *ip)
     ip->disable_allowed         = 0;
     ip->thr_spec_allowed        = 0;
     ip->carrier_migration_allowed = 0;
-    ip->atype			= BESTFIT;
+    ip->astrat			= ERTS_ALC_S_BESTFIT;
     ip->init.bf.ao		= 1;
     ip->init.util.ramv		= 0;
     ip->init.util.mmsbc		= 0;
@@ -349,7 +341,7 @@ set_default_exec_alloc_opts(struct au_init *ip)
     ip->disable_allowed         = 0;
     ip->thr_spec_allowed        = 0;
     ip->carrier_migration_allowed = 0;
-    ip->atype			= BESTFIT;
+    ip->astrat			= ERTS_ALC_S_BESTFIT;
     ip->init.bf.ao		= 1;
     ip->init.util.ramv		= 0;
     ip->init.util.mmsbc		= 0;
@@ -378,7 +370,7 @@ set_default_temp_alloc_opts(struct au_init *ip)
     ip->thr_spec		= 1;
     ip->disable_allowed         = 0;
     ip->carrier_migration_allowed = 0;
-    ip->atype			= AFIT;
+    ip->astrat			= ERTS_ALC_S_AFIT;
     ip->init.util.name_prefix	= "temp_";
     ip->init.util.alloc_no	= ERTS_ALC_A_TEMPORARY;
 #ifndef SMALL_MEMORY
@@ -397,7 +389,7 @@ set_default_eheap_alloc_opts(struct au_init *ip)
     SET_DEFAULT_ALLOC_OPTS(ip);
     ip->enable			= AU_ALLOC_DEFAULT_ENABLE(1);
     ip->thr_spec		= 1;
-    ip->atype			= GOODFIT;
+    ip->astrat			= ERTS_ALC_S_GOODFIT;
     ip->init.util.name_prefix	= "eheap_";
     ip->init.util.alloc_no	= ERTS_ALC_A_EHEAP;
 #ifndef SMALL_MEMORY
@@ -416,7 +408,7 @@ set_default_binary_alloc_opts(struct au_init *ip)
     SET_DEFAULT_ALLOC_OPTS(ip);
     ip->enable			= AU_ALLOC_DEFAULT_ENABLE(1);
     ip->thr_spec		= 1;
-    ip->atype			= BESTFIT;
+    ip->astrat			= ERTS_ALC_S_BESTFIT;
     ip->init.util.name_prefix	= "binary_";
     ip->init.util.alloc_no	= ERTS_ALC_A_BINARY;
 #ifndef SMALL_MEMORY
@@ -435,7 +427,7 @@ set_default_ets_alloc_opts(struct au_init *ip)
     SET_DEFAULT_ALLOC_OPTS(ip);
     ip->enable			= AU_ALLOC_DEFAULT_ENABLE(1);
     ip->thr_spec		= 1;
-    ip->atype			= BESTFIT;
+    ip->astrat			= ERTS_ALC_S_BESTFIT;
     ip->init.util.name_prefix	= "ets_";
     ip->init.util.alloc_no	= ERTS_ALC_A_ETS;
 #ifndef SMALL_MEMORY
@@ -453,7 +445,7 @@ set_default_driver_alloc_opts(struct au_init *ip)
     SET_DEFAULT_ALLOC_OPTS(ip);
     ip->enable			= AU_ALLOC_DEFAULT_ENABLE(1);
     ip->thr_spec		= 1;
-    ip->atype			= BESTFIT;
+    ip->astrat			= ERTS_ALC_S_BESTFIT;
     ip->init.util.name_prefix	= "driver_";
     ip->init.util.alloc_no	= ERTS_ALC_A_DRIVER;
 #ifndef SMALL_MEMORY
@@ -473,7 +465,7 @@ set_default_fix_alloc_opts(struct au_init *ip,
     SET_DEFAULT_ALLOC_OPTS(ip);
     ip->enable			= AU_ALLOC_DEFAULT_ENABLE(1);
     ip->thr_spec		= 1;
-    ip->atype			= BESTFIT;
+    ip->astrat			= ERTS_ALC_S_BESTFIT;
     ip->init.bf.ao = 1;
     ip->init.util.name_prefix	= "fix_";
     ip->init.util.fix_type_size	= fix_type_sizes;
@@ -493,7 +485,7 @@ set_default_test_alloc_opts(struct au_init *ip)
     SET_DEFAULT_ALLOC_OPTS(ip);
     ip->enable			= 0; /* Disabled by default */
     ip->thr_spec		= -1 * erts_no_schedulers;
-    ip->atype			= FIRSTFIT;
+    ip->astrat			= ERTS_ALC_S_FIRSTFIT;
     ip->init.aoff.crr_order     = FF_AOFF;
     ip->init.aoff.blk_order     = FF_BF;
     ip->init.util.name_prefix	= "test_";
@@ -552,8 +544,8 @@ start_au_allocator(ErtsAlcType_t alctr_n,
 static void
 refuse_af_strategy(struct au_init *init)
 {
-    if (init->atype == AFIT)
-	init->atype = GOODFIT;
+    if (init->astrat == ERTS_ALC_S_AFIT)
+	init->astrat = ERTS_ALC_S_GOODFIT;
 }
 
 #ifdef HARD_DEBUG
@@ -576,7 +568,10 @@ static void adjust_fix_alloc_sizes(UWord extra_block_size)
 	    for (i=0; i < tspec->size; i++) {
 		Allctr_t* allctr = tspec->allctr[i];
 		for (j=0; j < ERTS_ALC_NO_FIXED_SIZES; ++j) {
-		    allctr->fix[j].type_size += extra_block_size;
+                    size_t size = allctr->fix[j].type_size;
+                    size = MAX(size + extra_block_size,
+                               sizeof(ErtsAllctrDDBlock_t));
+		    allctr->fix[j].type_size = size;
 		}
 	    }
 	}
@@ -584,8 +579,11 @@ static void adjust_fix_alloc_sizes(UWord extra_block_size)
 	{
 	    Allctr_t* allctr = erts_allctrs_info[ERTS_ALC_A_FIXED_SIZE].extra;
 	    for (j=0; j < ERTS_ALC_NO_FIXED_SIZES; ++j) {
-		allctr->fix[j].type_size += extra_block_size;
-	    }	
+                size_t size = allctr->fix[j].type_size;
+                size = MAX(size + extra_block_size,
+                           sizeof(ErtsAllctrDDBlock_t));
+                allctr->fix[j].type_size = size;
+	    }
 	}
     }
 }
@@ -597,7 +595,7 @@ strategy_support_carrier_migration(struct au_init *auip)
      * Currently only aoff* and ageff* support carrier
      * migration, i.e, type AOFIRSTFIT.
      */
-    return auip->atype == FIRSTFIT;
+    return auip->astrat == ERTS_ALC_S_FIRSTFIT;
 }
 
 static ERTS_INLINE void
@@ -612,7 +610,7 @@ adjust_carrier_migration_support(struct au_init *auip)
 	 */
 	if (!strategy_support_carrier_migration(auip)) {
 	    /* Default to aoffcbf */
-	    auip->atype = FIRSTFIT;
+	    auip->astrat = ERTS_ALC_S_FIRSTFIT;
 	    auip->init.aoff.crr_order = FF_AOFF;
 	    auip->init.aoff.blk_order = FF_BF;
 	}
@@ -1018,7 +1016,7 @@ start_au_allocator(ErtsAlcType_t alctr_n,
     int i;
     int size = 1;
     void *as0;
-    enum allctr_type atype;
+    ErtsAlcStrat_t astrat;
     ErtsAllocatorFunctions_t *af = &erts_allctrs[alctr_n];
     ErtsAllocatorInfo_t *ai = &erts_allctrs_info[alctr_n];
     ErtsAllocatorThrSpec_t *tspec = &erts_allctr_thr_spec[alctr_n];
@@ -1077,7 +1075,7 @@ start_au_allocator(ErtsAlcType_t alctr_n,
 
     for (i = 0; i < size; i++) {
 	Allctr_t *as;
-	atype = init->atype;
+	astrat = init->astrat;
 
 	if (!init->thr_spec)
 	    as0 = state;
@@ -1094,8 +1092,8 @@ start_au_allocator(ErtsAlcType_t alctr_n,
 		if (i != 0)
 		    init->init.util.ts = 0;
 		else {
-		    if (atype == AFIT)
-			atype = GOODFIT;
+		    if (astrat == ERTS_ALC_S_AFIT)
+			astrat = ERTS_ALC_S_GOODFIT;
 		    init->init.util.ts = 1;
 		}
 		init->init.util.tspec = init->thr_spec + 1;
@@ -1109,25 +1107,26 @@ start_au_allocator(ErtsAlcType_t alctr_n,
 			 (((char *) fix_lists) + fix_list_size));
 	}
 
+        init->init.util.alloc_strat = astrat;
 	init->init.util.ix = i;
 
-	switch (atype) {
-	case GOODFIT:
+	switch (astrat) {
+	case ERTS_ALC_S_GOODFIT:
 	    as = erts_gfalc_start((GFAllctr_t *) as0,
 					   &init->init.gf,
 					   &init->init.util);
 	    break;
-	case BESTFIT:
+	case ERTS_ALC_S_BESTFIT:
 	    as = erts_bfalc_start((BFAllctr_t *) as0,
 					   &init->init.bf,
 					   &init->init.util);
 	    break;
-	case AFIT:
+	case ERTS_ALC_S_AFIT:
 	    as = erts_afalc_start((AFAllctr_t *) as0,
 					   &init->init.af,
 					   &init->init.util);
 	    break;
-	case FIRSTFIT:
+	case ERTS_ALC_S_FIRSTFIT:
 	    as = erts_aoffalc_start((AOFFAllctr_t *) as0,
 					     &init->init.aoff,
 					     &init->init.util);
@@ -1363,51 +1362,59 @@ handle_au_arg(struct au_init *auip,
 	else if(has_prefix("as", sub_param)) {
 	    char *alg = get_value(sub_param + 2, argv, ip);
 	    if (sys_strcmp("bf", alg) == 0) {
-		auip->atype = BESTFIT;
+		auip->astrat = ERTS_ALC_S_BESTFIT;
 		auip->init.bf.ao = 0;
 	    }
 	    else if (sys_strcmp("aobf", alg) == 0) {
-		auip->atype = BESTFIT;
+		auip->astrat = ERTS_ALC_S_BESTFIT;
 		auip->init.bf.ao = 1;
 	    }
 	    else if (sys_strcmp("gf", alg) == 0) {
-		auip->atype = GOODFIT;
+		auip->astrat = ERTS_ALC_S_GOODFIT;
 	    }
 	    else if (sys_strcmp("af", alg) == 0) {
-		auip->atype = AFIT;
+		auip->astrat = ERTS_ALC_S_AFIT;
 	    }
 	    else if (sys_strcmp("aoff", alg) == 0) {
-		auip->atype = FIRSTFIT;
+		auip->astrat = ERTS_ALC_S_FIRSTFIT;
 		auip->init.aoff.crr_order = FF_AOFF;
 		auip->init.aoff.blk_order = FF_AOFF;
 	    }
 	    else if (sys_strcmp("aoffcbf", alg) == 0) {
-		auip->atype = FIRSTFIT;
+		auip->astrat = ERTS_ALC_S_FIRSTFIT;
 		auip->init.aoff.crr_order = FF_AOFF;
 		auip->init.aoff.blk_order = FF_BF;
 	    }
 	    else if (sys_strcmp("aoffcaobf", alg) == 0) {
-		auip->atype = FIRSTFIT;
+		auip->astrat = ERTS_ALC_S_FIRSTFIT;
 		auip->init.aoff.crr_order = FF_AOFF;
 		auip->init.aoff.blk_order = FF_AOBF;
 	    }
             else if (sys_strcmp("ageffcaoff", alg) == 0) {
-                auip->atype = FIRSTFIT;
+                auip->astrat = ERTS_ALC_S_FIRSTFIT;
 		auip->init.aoff.crr_order = FF_AGEFF;
 		auip->init.aoff.blk_order = FF_AOFF;
             }
             else if (sys_strcmp("ageffcbf", alg) == 0) {
-                auip->atype = FIRSTFIT;
+                auip->astrat = ERTS_ALC_S_FIRSTFIT;
 		auip->init.aoff.crr_order = FF_AGEFF;
 		auip->init.aoff.blk_order = FF_BF;
             }
             else if (sys_strcmp("ageffcaobf", alg) == 0) {
-                auip->atype = FIRSTFIT;
+                auip->astrat = ERTS_ALC_S_FIRSTFIT;
 		auip->init.aoff.crr_order = FF_AGEFF;
 		auip->init.aoff.blk_order = FF_AOBF;
             }
 	    else {
-		bad_value(param, sub_param + 1, alg);
+                if (auip->init.util.alloc_no == ERTS_ALC_A_TEST
+                    && sys_strcmp("chaosff", alg) == 0) {
+                    auip->astrat = ERTS_ALC_S_FIRSTFIT;
+                    auip->init.aoff.crr_order = FF_CHAOS;
+                    auip->init.aoff.blk_order = FF_CHAOS;
+                }
+                else {
+                    bad_value(param, sub_param + 1, alg);
+                }
 	    }
 	    if (!strategy_support_carrier_migration(auip))
 		auip->init.util.acul = 0;
@@ -2030,33 +2037,55 @@ erts_realloc_n_enomem(ErtsAlcType_t n, void *ptr, Uint size)
 }
 
 static ERTS_INLINE UWord
-alcu_size(ErtsAlcType_t ai, ErtsAlcUFixInfo_t *fi, int fisz)
+alcu_size(ErtsAlcType_t alloc_no, ErtsAlcUFixInfo_t *fi, int fisz)
 {
-    UWord res = 0;
+    UWord res;
+    int ai;
 
-    ASSERT(erts_allctrs_info[ai].enabled);
-    ASSERT(erts_allctrs_info[ai].alloc_util);
+    if (!erts_allctrs_info[alloc_no].thr_spec) {
+        AllctrSize_t size;
+        Allctr_t *allctr;
 
-    if (!erts_allctrs_info[ai].thr_spec) {
-	Allctr_t *allctr = erts_allctrs_info[ai].extra;
-	AllctrSize_t asize;
-	erts_alcu_current_size(allctr, &asize, fi, fisz);
-	res += asize.blocks;
+        allctr = erts_allctrs_info[alloc_no].extra;
+        erts_alcu_current_size(allctr, &size, fi, fisz);
+
+        return size.blocks;
     }
-    else {
-	ErtsAllocatorThrSpec_t *tspec = &erts_allctr_thr_spec[ai];
-	int i;
 
-	ASSERT(tspec->enabled);
+    res = 0;
 
-	for (i = tspec->size - 1; i >= 0; i--) {
-	    Allctr_t *allctr = tspec->allctr[i];
-	    AllctrSize_t asize;
-	    if (allctr) {
-		erts_alcu_current_size(allctr, &asize, fi, fisz);
-		res += asize.blocks;
-	    }
-	}
+    /* Thread-specific allocators can migrate carriers across types, so we have
+     * to visit every allocator type to gather information on blocks that were
+     * allocated by us. */
+    for (ai = ERTS_ALC_A_MIN; ai < ERTS_ALC_A_MAX; ai++) {
+        ErtsAllocatorThrSpec_t *tspec;
+        Allctr_t *allctr;
+        int i;
+
+        if (!erts_allctrs_info[ai].thr_spec) {
+            continue;
+        }
+
+        tspec = &erts_allctr_thr_spec[ai];
+        ASSERT(tspec->enabled);
+
+        for (i = tspec->size - 1; i >= 0; i--) {
+            allctr = tspec->allctr[i];
+
+            if (allctr) {
+                AllctrSize_t size;
+
+                if (ai == alloc_no) {
+                    erts_alcu_current_size(allctr, &size, fi, fisz);
+                } else {
+                    erts_alcu_foreign_size(allctr, alloc_no, &size);
+                }
+
+                ASSERT(((SWord)size.blocks) >= 0);
+
+                res += size.blocks;
+            }
+        }
     }
 
     return res;
@@ -2400,6 +2429,7 @@ erts_memory(fmtfn_t *print_to_p, void *print_to_arg, void *proc, Eterm earg)
     }
 
     if (want_tot_or_sys) {
+        ASSERT(size.total >= size.processes);
 	size.system = size.total - size.processes;
     }
 
@@ -3459,29 +3489,29 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 	switch (op) {
 	case 0xf00:
 	    if (((Allctr_t *) a1)->thread_safe)
-		return (UWord) erts_alcu_alloc_ts(ERTS_ALC_T_UNDEF,
+		return (UWord) erts_alcu_alloc_ts(ERTS_ALC_T_TEST,
 							  (void *) a1,
 							  (Uint) a2);
 	    else
-		return (UWord) erts_alcu_alloc(ERTS_ALC_T_UNDEF,
+		return (UWord) erts_alcu_alloc(ERTS_ALC_T_TEST,
 						       (void *) a1,
 						       (Uint) a2);
 	case 0xf01:
 	    if (((Allctr_t *) a1)->thread_safe)
-		return (UWord) erts_alcu_realloc_ts(ERTS_ALC_T_UNDEF,
+		return (UWord) erts_alcu_realloc_ts(ERTS_ALC_T_TEST,
 							    (void *) a1,
 							    (void *) a2,
 							    (Uint) a3);
 	    else
-		return (UWord) erts_alcu_realloc(ERTS_ALC_T_UNDEF,
+		return (UWord) erts_alcu_realloc(ERTS_ALC_T_TEST,
 							 (void *) a1,
 							 (void *) a2,
 							 (Uint) a3);
 	case 0xf02:
 	    if (((Allctr_t *) a1)->thread_safe)
-		erts_alcu_free_ts(ERTS_ALC_T_UNDEF, (void *) a1, (void *) a2);
+		erts_alcu_free_ts(ERTS_ALC_T_TEST, (void *) a1, (void *) a2);
 	    else
-		erts_alcu_free(ERTS_ALC_T_UNDEF, (void *) a1, (void *) a2);
+		erts_alcu_free(ERTS_ALC_T_TEST, (void *) a1, (void *) a2);
 	    return 0;
 	case 0xf03: {
 	    Allctr_t *allctr;
@@ -3489,8 +3519,10 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 
 	    SET_DEFAULT_ALLOC_OPTS(&init);
 	    init.enable = 1;
-	    init.atype = GOODFIT;
+	    init.astrat = ERTS_ALC_S_GOODFIT;
 	    init.init.util.name_prefix = (char *) a1;
+	    init.init.util.alloc_no = ERTS_ALC_A_TEST;
+	    init.init.util.alloc_strat = init.astrat;
 	    init.init.util.ts = 1;
 	    if ((char **) a3) {
 		char **argv = (char **) a3;
@@ -3504,31 +3536,31 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 		}
 	    }
 
-	    switch (init.atype) {
-	    case GOODFIT:
+	    switch (init.astrat) {
+	    case ERTS_ALC_S_GOODFIT:
 		allctr = erts_gfalc_start((GFAllctr_t *)
-					  erts_alloc(ERTS_ALC_T_UNDEF,
+					  erts_alloc(ERTS_ALC_T_TEST,
 						     sizeof(GFAllctr_t)),
 					  &init.init.gf,
 					  &init.init.util);
 		break;
-	    case BESTFIT:
+	    case ERTS_ALC_S_BESTFIT:
 		allctr = erts_bfalc_start((BFAllctr_t *)
-					  erts_alloc(ERTS_ALC_T_UNDEF,
+					  erts_alloc(ERTS_ALC_T_TEST,
 						     sizeof(BFAllctr_t)),
 					  &init.init.bf,
 					  &init.init.util);
 		break;
-	    case AFIT:
+	    case ERTS_ALC_S_AFIT:
 		allctr = erts_afalc_start((AFAllctr_t *)
-					  erts_alloc(ERTS_ALC_T_UNDEF,
+					  erts_alloc(ERTS_ALC_T_TEST,
 							    sizeof(AFAllctr_t)),
 					  &init.init.af,
 					  &init.init.util);
 		break;
-	    case FIRSTFIT:
+	    case ERTS_ALC_S_FIRSTFIT:
 		allctr = erts_aoffalc_start((AOFFAllctr_t *)
-					  erts_alloc(ERTS_ALC_T_UNDEF,
+					  erts_alloc(ERTS_ALC_T_TEST,
 						     sizeof(AOFFAllctr_t)),
 					  &init.init.aoff,
 					  &init.init.util);
@@ -3544,7 +3576,7 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 	}
 	case 0xf04:
 	    erts_alcu_stop((Allctr_t *) a1);
-	    erts_free(ERTS_ALC_T_UNDEF, (void *) a1);
+	    erts_free(ERTS_ALC_T_TEST, (void *) a1);
 	    break;
 	case 0xf05: return (UWord) 1;
 	case 0xf06: return (UWord) ((Allctr_t *) a1)->thread_safe;
@@ -3554,7 +3586,7 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 	case 0xf07: return (UWord) ((Allctr_t *) a1)->thread_safe;
 #endif
 	case 0xf08: {
-	    ethr_mutex *mtx = erts_alloc(ERTS_ALC_T_UNDEF, sizeof(ethr_mutex));
+	    ethr_mutex *mtx = erts_alloc(ERTS_ALC_T_TEST, sizeof(ethr_mutex));
 	    if (ethr_mutex_init(mtx) != 0)
 		ERTS_ALC_TEST_ABORT;
 	    return (UWord) mtx;
@@ -3563,7 +3595,7 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 	    ethr_mutex *mtx = (ethr_mutex *) a1;
 	    if (ethr_mutex_destroy(mtx) != 0)
 		ERTS_ALC_TEST_ABORT;
-	    erts_free(ERTS_ALC_T_UNDEF, (void *) mtx);
+	    erts_free(ERTS_ALC_T_TEST, (void *) mtx);
 	    break;
 	}
 	case 0xf0a:
@@ -3573,7 +3605,7 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 	    ethr_mutex_unlock((ethr_mutex *) a1);
 	    break;
 	case 0xf0c: {
-	    ethr_cond *cnd = erts_alloc(ERTS_ALC_T_UNDEF, sizeof(ethr_cond));
+	    ethr_cond *cnd = erts_alloc(ERTS_ALC_T_TEST, sizeof(ethr_cond));
 	    if (ethr_cond_init(cnd) != 0)
 		ERTS_ALC_TEST_ABORT;
 	    return (UWord) cnd;
@@ -3582,7 +3614,7 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 	    ethr_cond *cnd = (ethr_cond *) a1;
 	    if (ethr_cond_destroy(cnd) != 0)
 		ERTS_ALC_TEST_ABORT;
-	    erts_free(ERTS_ALC_T_UNDEF, (void *) cnd);
+	    erts_free(ERTS_ALC_T_TEST, (void *) cnd);
 	    break;
 	}
 	case 0xf0e:
@@ -3596,7 +3628,7 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 	    break;
 	}
 	case 0xf10: {
-	    ethr_tid *tid = erts_alloc(ERTS_ALC_T_UNDEF, sizeof(ethr_tid));
+	    ethr_tid *tid = erts_alloc(ERTS_ALC_T_TEST, sizeof(ethr_tid));
 	    if (ethr_thr_create(tid,
 				(void * (*)(void *)) a1,
 				(void *) a2,
@@ -3608,7 +3640,7 @@ UWord erts_alc_test(UWord op, UWord a1, UWord a2, UWord a3)
 	    ethr_tid *tid = (ethr_tid *) a1;
 	    if (ethr_thr_join(*tid, NULL) != 0)
 		ERTS_ALC_TEST_ABORT;
-	    erts_free(ERTS_ALC_T_UNDEF, (void *) tid);
+	    erts_free(ERTS_ALC_T_TEST, (void *) tid);
 	    break;
 	}
 	case 0xf12:
@@ -3872,7 +3904,7 @@ check_memory_fence(void *ptr, Uint *size, ErtsAlcType_t n, int func)
 {
     Uint sz;
     Uint found_type;
-    UWord pre_pattern;
+    UWord pre_pattern, expected_pattern;
     UWord post_pattern;
     UWord *ui_ptr;
 #ifdef HARD_DEBUG
@@ -3882,6 +3914,8 @@ check_memory_fence(void *ptr, Uint *size, ErtsAlcType_t n, int func)
     if (!ptr)
 	return NULL;
 
+    expected_pattern = MK_PATTERN(n);
+
     ui_ptr = (UWord *) ptr;
     pre_pattern = *(--ui_ptr);
     *size = sz = *(--ui_ptr);
@@ -3890,7 +3924,13 @@ check_memory_fence(void *ptr, Uint *size, ErtsAlcType_t n, int func)
 #endif
 
     found_type = GET_TYPE_OF_PATTERN(pre_pattern);
-    if (pre_pattern != MK_PATTERN(n)) {
+
+    if (found_type != n) {
+        erts_exit(ERTS_ABORT_EXIT, "ERROR: Miss matching allocator types"
+                  " used in alloc and free\n");
+    }
+
+    if (pre_pattern != expected_pattern) {
 	if ((FIXED_FENCE_PATTERN_MASK & pre_pattern) != FIXED_FENCE_PATTERN)
 	    erts_exit(ERTS_ABORT_EXIT,
 		     "ERROR: Fence at beginning of memory block (p=0x%u) "
@@ -3900,8 +3940,7 @@ check_memory_fence(void *ptr, Uint *size, ErtsAlcType_t n, int func)
 
     sys_memcpy((void *) &post_pattern, (void *) (((char *)ptr)+sz), sizeof(UWord));
 
-    if (post_pattern != MK_PATTERN(n)
-	|| pre_pattern != post_pattern) {
+    if (post_pattern != expected_pattern || pre_pattern != post_pattern) {
 	char fbuf[10];
 	char obuf[10];
 	char *ftype;
@@ -3960,9 +3999,10 @@ check_memory_fence(void *ptr, Uint *size, ErtsAlcType_t n, int func)
 static ErtsAllocatorFunctions_t real_allctrs[ERTS_ALC_A_MAX+1];
 
 static void *
-debug_alloc(ErtsAlcType_t n, void *extra, Uint size)
+debug_alloc(ErtsAlcType_t type, void *extra, Uint size)
 {
     ErtsAllocatorFunctions_t *real_af = (ErtsAllocatorFunctions_t *) extra;
+    ErtsAlcType_t n;
     Uint dsize;
     void *res;
 
@@ -3970,9 +4010,11 @@ debug_alloc(ErtsAlcType_t n, void *extra, Uint size)
     erts_hdbg_chk_blks();
 #endif
 
+    n = ERTS_ALC_T2N(type);
+
     ASSERT(ERTS_ALC_N_MIN <= n && n <= ERTS_ALC_N_MAX);
     dsize = size + FENCE_SZ;
-    res = (*real_af->alloc)(n, real_af->extra, dsize);
+    res = (*real_af->alloc)(type, real_af->extra, dsize);
 
     res = set_memory_fence(res, size, n);
 
@@ -3986,14 +4028,17 @@ debug_alloc(ErtsAlcType_t n, void *extra, Uint size)
 
 
 static void *
-debug_realloc(ErtsAlcType_t n, void *extra, void *ptr, Uint size)
+debug_realloc(ErtsAlcType_t type, void *extra, void *ptr, Uint size)
 {
     ErtsAllocatorFunctions_t *real_af = (ErtsAllocatorFunctions_t *) extra;
+    ErtsAlcType_t n;
     Uint dsize;
     Uint old_size;
     void *dptr;
     void *res;
 
+    n = ERTS_ALC_T2N(type);
+
     ASSERT(ERTS_ALC_N_MIN <= n && n <= ERTS_ALC_N_MAX);
 
     dsize = size + FENCE_SZ;
@@ -4003,12 +4048,12 @@ debug_realloc(ErtsAlcType_t n, void *extra, void *ptr, Uint size)
     erts_hdbg_chk_blks();
 #endif
 
-    if (old_size > size)
+    if (ptr && old_size > size)
 	sys_memset((void *) (((char *) ptr) + size),
 		   0xf,
 		   sizeof(Uint) + old_size - size);
 
-    res = (*real_af->realloc)(n, real_af->extra, dptr, dsize);
+    res = (*real_af->realloc)(type, real_af->extra, dptr, dsize);
 
     res = set_memory_fence(res, size, n);
 
@@ -4021,12 +4066,16 @@ debug_realloc(ErtsAlcType_t n, void *extra, void *ptr, Uint size)
 }
 
 static void
-debug_free(ErtsAlcType_t n, void *extra, void *ptr)
+debug_free(ErtsAlcType_t type, void *extra, void *ptr)
 {
     ErtsAllocatorFunctions_t *real_af = (ErtsAllocatorFunctions_t *) extra;
+    ErtsAlcType_t n;
     void *dptr;
     Uint size;
-    int free_pattern = n;
+    int free_pattern;
+
+    n = ERTS_ALC_T2N(type);
+    free_pattern = n;
 
     ASSERT(ERTS_ALC_N_MIN <= n && n <= ERTS_ALC_N_MAX);
 
@@ -4044,7 +4093,7 @@ debug_free(ErtsAlcType_t n, void *extra, void *ptr)
 #endif
     sys_memset((void *) dptr, free_pattern, size + FENCE_SZ);
 
-    (*real_af->free)(n, real_af->extra, dptr);
+    (*real_af->free)(type, real_af->extra, dptr);
 
 #ifdef PRINT_OPS
     fprintf(stderr, "free(%s, 0x%lx)\r\n", ERTS_ALC_N2TD(n), (Uint) ptr);
diff --git a/erts/emulator/beam/erl_alloc.h b/erts/emulator/beam/erl_alloc.h
index fcb58ff58a..c13cf3f5b0 100644
--- a/erts/emulator/beam/erl_alloc.h
+++ b/erts/emulator/beam/erl_alloc.h
@@ -26,10 +26,23 @@
 #define ERL_THR_PROGRESS_TSD_TYPE_ONLY
 #include "erl_thr_progress.h"
 #undef ERL_THR_PROGRESS_TSD_TYPE_ONLY
-#include "erl_alloc_util.h"
 #include "erl_threads.h"
 #include "erl_mmap.h"
 
+typedef enum {
+    ERTS_ALC_S_INVALID = 0,
+
+    ERTS_ALC_S_GOODFIT,
+    ERTS_ALC_S_BESTFIT,
+    ERTS_ALC_S_AFIT,
+    ERTS_ALC_S_FIRSTFIT,
+
+    ERTS_ALC_S_MIN = ERTS_ALC_S_GOODFIT,
+    ERTS_ALC_S_MAX = ERTS_ALC_S_FIRSTFIT
+} ErtsAlcStrat_t;
+
+#include "erl_alloc_util.h"
+
 #ifdef DEBUG
 #  undef ERTS_ALC_WANT_INLINE
 #  define ERTS_ALC_WANT_INLINE 0
@@ -52,6 +65,14 @@
 #define ERTS_ALC_NO_FIXED_SIZES \
   (ERTS_ALC_N_MAX_A_FIXED_SIZE - ERTS_ALC_N_MIN_A_FIXED_SIZE + 1)
 
+#define ERTS_ALC_IS_FIX_TYPE(T) \
+    (ERTS_ALC_T2N(T) >= ERTS_ALC_N_MIN_A_FIXED_SIZE && \
+     ERTS_ALC_T2N(T) <= ERTS_ALC_N_MAX_A_FIXED_SIZE)
+
+#define ERTS_ALC_FIX_TYPE_IX(T) \
+  (ASSERT(ERTS_ALC_IS_FIX_TYPE(T)), \
+   ERTS_ALC_T2N((T)) - ERTS_ALC_N_MIN_A_FIXED_SIZE)
+
 void erts_sys_alloc_init(void);
 void *erts_sys_alloc(ErtsAlcType_t, void *, Uint);
 void *erts_sys_realloc(ErtsAlcType_t, void *, void *, Uint);
@@ -228,7 +249,7 @@ void *erts_alloc(ErtsAlcType_t type, Uint size)
     void *res;
     ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
     res = (*erts_allctrs[ERTS_ALC_T2A(type)].alloc)(
-            ERTS_ALC_T2N(type),
+            type,
             erts_allctrs[ERTS_ALC_T2A(type)].extra,
             size);
     if (!res)
@@ -243,7 +264,7 @@ void *erts_realloc(ErtsAlcType_t type, void *ptr, Uint size)
     void *res;
     ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
     res = (*erts_allctrs[ERTS_ALC_T2A(type)].realloc)(
-	ERTS_ALC_T2N(type),
+	type,
 	erts_allctrs[ERTS_ALC_T2A(type)].extra,
 	ptr,
 	size);
@@ -258,7 +279,7 @@ void erts_free(ErtsAlcType_t type, void *ptr)
 {
     ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
     (*erts_allctrs[ERTS_ALC_T2A(type)].free)(
-	ERTS_ALC_T2N(type),
+	type,
 	erts_allctrs[ERTS_ALC_T2A(type)].extra,
 	ptr);
     ERTS_MSACC_POP_STATE_X();
@@ -271,7 +292,7 @@ void *erts_alloc_fnf(ErtsAlcType_t type, Uint size)
     void *res;
     ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
     res = (*erts_allctrs[ERTS_ALC_T2A(type)].alloc)(
-	ERTS_ALC_T2N(type),
+	type,
 	erts_allctrs[ERTS_ALC_T2A(type)].extra,
 	size);
     ERTS_MSACC_POP_STATE_X();
@@ -285,7 +306,7 @@ void *erts_realloc_fnf(ErtsAlcType_t type, void *ptr, Uint size)
     void *res;
     ERTS_MSACC_PUSH_AND_SET_STATE_X(ERTS_MSACC_STATE_ALLOC);
     res = (*erts_allctrs[ERTS_ALC_T2A(type)].realloc)(
-	ERTS_ALC_T2N(type),
+	type,
 	erts_allctrs[ERTS_ALC_T2A(type)].extra,
 	ptr,
 	size);
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
index 4f03a34390..21941ba96e 100644
--- a/erts/emulator/beam/erl_alloc.types
+++ b/erts/emulator/beam/erl_alloc.types
@@ -30,10 +30,10 @@
 #   name space).
 # * Types, allocators, classes, and descriptions have different name
 #   spaces.
-# * The type, allocator, and class names INVALID are reserved and can
-#   not be used.
+# * The type, allocator, and class names INVALID are reserved and
+#   cannot be used.
 # * The descriptions invalid_allocator, invalid_class, and invalid_type
-#   are reserved and can not be used.
+#   are reserved and cannot be used.
 # * Declarations can be done conditionally by use of a
 #     +if <boolean_variable>
 #
@@ -149,6 +149,7 @@ type	MODULE_TABLE	LONG_LIVED	CODE		module_tab
 type	TAINT		LONG_LIVED	CODE		taint_list
 type	MODULE_REFS	STANDARD	CODE		module_refs
 type	NC_TMP		TEMPORARY	SYSTEM		nc_tmp
+type	NC_STD		STANDARD	SYSTEM		nc_std
 type	TMP		TEMPORARY	SYSTEM		tmp
 type	UNDEF		SYSTEM		SYSTEM		undefined
 type	DCACHE		STANDARD	SYSTEM		dcache
@@ -275,11 +276,14 @@ type	ML_DIST		STANDARD	SYSTEM		monitor_link_dist
 type	PF3_ARGS	SHORT_LIVED	PROCESSES	process_flag_3_arguments
 type	SETUP_CONN_ARG	SHORT_LIVED	PROCESSES	setup_connection_argument
 type    LIST_TRAP       SHORT_LIVED     PROCESSES       list_bif_trap_state
+type    CONT_EXIT_TRAP  SHORT_LIVED     PROCESSES       continue_exit_trap_state
+type    SEQ_YIELD_STATE SHORT_LIVED     SYSTEM          dist_seq_yield_state
 
 type	ENVIRONMENT	SYSTEM		SYSTEM		environment
 
 type	PERSISTENT_TERM	LONG_LIVED	CODE		persisten_term
 type	PERSISTENT_LOCK_Q SHORT_LIVED	SYSTEM		persistent_lock_q
+type	PERSISTENT_TERM_TMP SHORT_LIVED	SYSTEM		persistent_term_tmp_table
 
 #
 # Types used for special emulators
@@ -345,16 +349,17 @@ type	COUNTERS	STANDARD	SYSTEM		erl_bif_counters
 # Types used by system specific code
 #
 
-type  	TEMP_TERM 	TEMPORARY	SYSTEM		temp_term
-type	DRV_TAB		LONG_LIVED	SYSTEM		drv_tab
-type	DRV_EV_STATE	LONG_LIVED	SYSTEM		driver_event_state
-type	DRV_SEL_D_STATE	FIXED_SIZE	SYSTEM		driver_select_data_state
-type	NIF_SEL_D_STATE	FIXED_SIZE	SYSTEM		enif_select_data_state
-type	POLLSET		LONG_LIVED	SYSTEM		pollset
-type	POLLSET_UPDREQ	SHORT_LIVED	SYSTEM		pollset_update_req
-type	POLL_FDS	LONG_LIVED	SYSTEM		poll_fds
-type	FD_STATUS	LONG_LIVED	SYSTEM		fd_status
-type	SELECT_FDS	LONG_LIVED	SYSTEM		select_fds
+type  	TEMP_TERM       	TEMPORARY	SYSTEM		temp_term
+type  	SHORT_LIVED_TERM 	SHORT_LIVED	SYSTEM		short_lived_term
+type	DRV_TAB		        LONG_LIVED	SYSTEM		drv_tab
+type	DRV_EV_STATE	        LONG_LIVED	SYSTEM		driver_event_state
+type	DRV_SEL_D_STATE	        FIXED_SIZE	SYSTEM		driver_select_data_state
+type	NIF_SEL_D_STATE	        FIXED_SIZE	SYSTEM		enif_select_data_state
+type	POLLSET		        LONG_LIVED	SYSTEM		pollset
+type	POLLSET_UPDREQ	        SHORT_LIVED	SYSTEM		pollset_update_req
+type	POLL_FDS	        LONG_LIVED	SYSTEM		poll_fds
+type	FD_STATUS	        LONG_LIVED	SYSTEM		fd_status
+type	SELECT_FDS	        LONG_LIVED	SYSTEM		select_fds
 
 +if unix
 
diff --git a/erts/emulator/beam/erl_alloc_util.c b/erts/emulator/beam/erl_alloc_util.c
index 0be4562785..bfc2f5992c 100644
--- a/erts/emulator/beam/erl_alloc_util.c
+++ b/erts/emulator/beam/erl_alloc_util.c
@@ -42,6 +42,7 @@
 
 #include "global.h"
 #include "big.h"
+#include "erl_mmap.h"
 #include "erl_mtrace.h"
 #define GET_ERL_ALLOC_UTIL_IMPL
 #include "erl_alloc_util.h"
@@ -90,15 +91,18 @@ static int initialized = 0;
 #define SYS_ALLOC_CARRIER_FLOOR(X)	((X) & SYS_ALLOC_CARRIER_MASK)
 #define SYS_ALLOC_CARRIER_CEILING(X) \
   SYS_ALLOC_CARRIER_FLOOR((X) + INV_SYS_ALLOC_CARRIER_MASK)
+#define SYS_PAGE_SIZE                   (sys_page_size)
+#define SYS_PAGE_SZ_MASK                ((UWord)(SYS_PAGE_SIZE - 1))
 
 #if 0
 /* Can be useful for debugging */
 #define MBC_REALLOC_ALWAYS_MOVES
 #endif
 
-
 /* alloc_util global parameters */
 static Uint sys_alloc_carrier_size;
+static Uint sys_page_size;
+
 #if HAVE_ERTS_MSEG
 static Uint max_mseg_carriers;
 #endif
@@ -113,32 +117,38 @@ static int allow_sys_alloc_carriers;
 
 #define DEC_CC(CC) ((CC)--)
 
-/* Multi block carrier (MBC) memory layout in R16: 
+/* Multi block carrier (MBC) memory layout in OTP 22:
 
 Empty MBC:
-[Carrier_t|pad|Block_t L0T|fhdr| free... ]
+[Carrier_t|pad|Block_t L0T0|fhdr| free... ]
 
 MBC after allocating first block:
-[Carrier_t|pad|Block_t 000|        udata        |pad|Block_t L0T|fhdr| free... ]
+[Carrier_t|pad|Block_t 0000|        udata        |pad|Block_t L0T0|fhdr| free... ]
 
 MBC after allocating second block:
-[Carrier_t|pad|Block_t 000|        udata        |pad|Block_t 000|   udata   |pad|Block_t L0T|fhdr| free... ]
+[Carrier_t|pad|Block_t 0000|        udata        |pad|Block_t 0000|   udata   |pad|Block_t L0T0|fhdr| free... ]
 
 MBC after deallocating first block:
-[Carrier_t|pad|Block_t 00T|fhdr| free  |FreeBlkFtr_t|Block_t 0P0|   udata   |pad|Block_t L0T|fhdr| free... ]
+[Carrier_t|pad|Block_t 00T0|fhdr| free  |FreeBlkFtr_t|Block_t 0P00|   udata   |pad|Block_t L0T0|fhdr| free... ]
 
+MBC after allocating first block, with allocation tagging enabled:
+[Carrier_t|pad|Block_t 000A|        udata        |atag|pad|Block_t L0T0|fhdr| free... ]
 
     udata = Allocated user data
+    atag  = A tag with basic metadata about this allocation
     pad   = Padding to ensure correct alignment for user data
     fhdr  = Allocator specific header to keep track of free block
     free  = Unused free memory
     T     = This block is free (THIS_FREE_BLK_HDR_FLG)
     P     = Previous block is free (PREV_FREE_BLK_HDR_FLG)
     L     = Last block in carrier (LAST_BLK_HDR_FLG)
+    A     = Block has an allocation tag footer, only valid for allocated blocks
+            (ATAG_BLK_HDR_FLG)
 */
 
 /* Single block carrier (SBC):
-[Carrier_t|pad|Block_t 111| udata... ]
+[Carrier_t|pad|Block_t 1110| udata... ]
+[Carrier_t|pad|Block_t 111A| udata | atag]
 */
 
 /* Allocation tags ...
@@ -154,20 +164,20 @@ MBC after deallocating first block:
 
 typedef UWord alcu_atag_t;
 
-#define MAKE_ATAG(IdAtom, Type) \
-    (ASSERT((Type) >= ERTS_ALC_N_MIN && (Type) <= ERTS_ALC_N_MAX), \
+#define MAKE_ATAG(IdAtom, TypeNum) \
+    (ASSERT((TypeNum) >= ERTS_ALC_N_MIN && (TypeNum) <= ERTS_ALC_N_MAX), \
      ASSERT(atom_val(IdAtom) <= MAX_ATAG_ATOM_ID), \
-     (atom_val(IdAtom) << ERTS_ALC_N_BITS) | (Type))
+     (atom_val(IdAtom) << ERTS_ALC_N_BITS) | (TypeNum))
 
 #define ATAG_ID(AT) (make_atom((AT) >> ERTS_ALC_N_BITS))
 #define ATAG_TYPE(AT) ((AT) & ERTS_ALC_N_MASK)
 
 #define MAX_ATAG_ATOM_ID (ERTS_UWORD_MAX >> ERTS_ALC_N_BITS)
 
-#define DBG_IS_VALID_ATAG(Allocator, AT) \
+#define DBG_IS_VALID_ATAG(AT) \
     (ATAG_TYPE(AT) >= ERTS_ALC_N_MIN && \
      ATAG_TYPE(AT) <= ERTS_ALC_N_MAX && \
-     (Allocator)->alloc_no == ERTS_ALC_T2A(ERTS_ALC_N2T(ATAG_TYPE(AT))))
+     ATAG_ID(AT) <= MAX_ATAG_ATOM_ID)
 
 /* Blocks ... */
 
@@ -182,10 +192,15 @@ typedef UWord alcu_atag_t;
 #endif
 #define FBLK_FTR_SZ (sizeof(FreeBlkFtr_t))
 
+#define BLK_HAS_ATAG(B) \
+    (!!((B)->bhdr & ATAG_BLK_HDR_FLG))
+
 #define GET_BLK_ATAG(B) \
-    (((alcu_atag_t *) (((char *) (B)) + (BLK_SZ(B))))[-1])
+    (ASSERT(BLK_HAS_ATAG(B)), \
+     ((alcu_atag_t *) (((char *) (B)) + (BLK_SZ(B))))[-1])
 #define SET_BLK_ATAG(B, T) \
-    (((alcu_atag_t *) (((char *) (B)) + (BLK_SZ(B))))[-1] = (T))
+    ((B)->bhdr |= ATAG_BLK_HDR_FLG, \
+     ((alcu_atag_t *) (((char *) (B)) + (BLK_SZ(B))))[-1] = (T))
 
 #define BLK_ATAG_SZ(AP) ((AP)->atags ? sizeof(alcu_atag_t) : 0)
 
@@ -203,13 +218,13 @@ typedef UWord alcu_atag_t;
   (((FreeBlkFtr_t *) (((char *) (B)) + (SZ)))[-1] = (SZ))
 
 #define SET_MBC_ABLK_SZ(B, SZ) \
-  (ASSERT(((SZ) & FLG_MASK) == 0), \
+  (ASSERT(((SZ) & BLK_FLG_MASK) == 0), \
    (B)->bhdr = (((B)->bhdr) & ~MBC_ABLK_SZ_MASK) | (SZ))
 #define SET_MBC_FBLK_SZ(B, SZ) \
-  (ASSERT(((SZ) & FLG_MASK) == 0), \
+  (ASSERT(((SZ) & BLK_FLG_MASK) == 0), \
    (B)->bhdr = (((B)->bhdr) & ~MBC_FBLK_SZ_MASK) | (SZ))
 #define SET_SBC_BLK_SZ(B, SZ) \
-  (ASSERT(((SZ) & FLG_MASK) == 0), \
+  (ASSERT(((SZ) & BLK_FLG_MASK) == 0), \
    (B)->bhdr = (((B)->bhdr) & ~SBC_BLK_SZ_MASK) | (SZ))
 #define SET_PREV_BLK_FREE(AP,B) \
   (ASSERT(!IS_MBC_FIRST_BLK(AP,B)), \
@@ -235,12 +250,12 @@ typedef UWord alcu_atag_t;
 
 #  define SET_MBC_ABLK_HDR(B, Sz, F, C) \
     (ASSERT(((Sz) & ~MBC_ABLK_SZ_MASK) == 0), \
-     ASSERT(!((UWord)(F) & (~FLG_MASK|THIS_FREE_BLK_HDR_FLG))), \
+     ASSERT(!((UWord)(F) & (~BLK_FLG_MASK|THIS_FREE_BLK_HDR_FLG))), \
      (B)->bhdr = ((Sz) | (F) | (BLK_CARRIER_OFFSET(B,C) << MBC_ABLK_OFFSET_SHIFT)))
 
 #  define SET_MBC_FBLK_HDR(B, Sz, F, C) \
     (ASSERT(((Sz) & ~MBC_FBLK_SZ_MASK) == 0), \
-     ASSERT(((UWord)(F) & (~FLG_MASK|THIS_FREE_BLK_HDR_FLG|PREV_FREE_BLK_HDR_FLG)) == THIS_FREE_BLK_HDR_FLG), \
+     ASSERT(((UWord)(F) & (~BLK_FLG_MASK|THIS_FREE_BLK_HDR_FLG|PREV_FREE_BLK_HDR_FLG)) == THIS_FREE_BLK_HDR_FLG), \
      (B)->bhdr = ((Sz) | (F)), \
      (B)->u.carrier = (C))
 
@@ -257,8 +272,8 @@ typedef UWord alcu_atag_t;
 #  define SET_BLK_FREE(B) \
   (ASSERT(!IS_PREV_BLK_FREE(B)), \
    (B)->u.carrier = ABLK_TO_MBC(B), \
-   (B)->bhdr |= THIS_FREE_BLK_HDR_FLG, \
-   (B)->bhdr &= (MBC_ABLK_SZ_MASK|FLG_MASK))
+   (B)->bhdr &= (MBC_ABLK_SZ_MASK|LAST_BLK_HDR_FLG), \
+   (B)->bhdr |= THIS_FREE_BLK_HDR_FLG)
 
 #  define SET_BLK_ALLOCED(B) \
   (ASSERT(((B)->bhdr & (MBC_ABLK_OFFSET_MASK|THIS_FREE_BLK_HDR_FLG)) == THIS_FREE_BLK_HDR_FLG), \
@@ -270,15 +285,16 @@ typedef UWord alcu_atag_t;
 #  define MBC_SZ_MAX_LIMIT ((UWord)~0)
 
 #  define SET_MBC_ABLK_HDR(B, Sz, F, C) \
-    (ASSERT(((Sz) & FLG_MASK) == 0), \
-     ASSERT(!((UWord)(F) & (~FLG_MASK|THIS_FREE_BLK_HDR_FLG))), \
-     ASSERT((UWord)(F) < SBC_BLK_HDR_FLG), \
+    (ASSERT(((Sz) & BLK_FLG_MASK) == 0), \
+     ASSERT(((F) & ~BLK_FLG_MASK) == 0), \
+     ASSERT(!((UWord)(F) & (~BLK_FLG_MASK|THIS_FREE_BLK_HDR_FLG))), \
      (B)->bhdr = ((Sz) | (F)), \
      (B)->carrier = (C))
 
 #  define SET_MBC_FBLK_HDR(B, Sz, F, C) \
-    (ASSERT(((Sz) & FLG_MASK) == 0), \
-     ASSERT(((UWord)(F) & (~FLG_MASK|THIS_FREE_BLK_HDR_FLG|PREV_FREE_BLK_HDR_FLG)) == THIS_FREE_BLK_HDR_FLG), \
+    (ASSERT(((Sz) & BLK_FLG_MASK) == 0), \
+     ASSERT(((F) & ~BLK_FLG_MASK) == 0), \
+     ASSERT(((UWord)(F) & (~BLK_FLG_MASK|THIS_FREE_BLK_HDR_FLG|PREV_FREE_BLK_HDR_FLG)) == THIS_FREE_BLK_HDR_FLG), \
      (B)->bhdr = ((Sz) | (F)), \
      (B)->carrier = (C))
 
@@ -297,7 +313,7 @@ typedef UWord alcu_atag_t;
 #endif /* !MBC_ABLK_OFFSET_BITS */
 
 #define SET_SBC_BLK_HDR(B, Sz) \
-  (ASSERT(((Sz) & FLG_MASK) == 0), (B)->bhdr = ((Sz) | (SBC_BLK_HDR_FLG)))
+  (ASSERT(((Sz) & BLK_FLG_MASK) == 0), (B)->bhdr = ((Sz) | (SBC_BLK_HDR_FLG)))
 
 
 #define BLK_UMEM_SZ(B) \
@@ -320,7 +336,7 @@ typedef UWord alcu_atag_t;
 #define GET_PREV_FREE_BLK_HDR_FLG(B) \
   ((B)->bhdr & PREV_FREE_BLK_HDR_FLG)
 #define GET_BLK_HDR_FLGS(B) \
-  ((B)->bhdr & FLG_MASK)
+  ((B)->bhdr & BLK_FLG_MASK)
 
 #define NXT_BLK(B) \
   (ASSERT(IS_MBC_BLK(B)), \
@@ -419,7 +435,7 @@ do {										\
 #define SCH_SBC				SBC_CARRIER_HDR_FLAG
 
 #define SET_CARRIER_HDR(C, Sz, F, AP) \
-  (ASSERT(((Sz) & FLG_MASK) == 0), (C)->chdr = ((Sz) | (F)), \
+  (ASSERT(((Sz) & CRR_FLG_MASK) == 0), (C)->chdr = ((Sz) | (F)), \
    erts_atomic_init_nob(&(C)->allctr, (erts_aint_t) (AP)))
 
 #define BLK_TO_SBC(B) \
@@ -444,8 +460,8 @@ do {										\
   (!IS_SB_CARRIER((C)))
 
 #define SET_CARRIER_SZ(C, SZ) \
-  (ASSERT(((SZ) & FLG_MASK) == 0), \
-   ((C)->chdr = ((C)->chdr & FLG_MASK) | (SZ)))
+  (ASSERT(((SZ) & CRR_FLG_MASK) == 0), \
+   ((C)->chdr = ((C)->chdr & CRR_FLG_MASK) | (SZ)))
 
 #define CFLG_SBC				(1 << 0)
 #define CFLG_MBC				(1 << 1)
@@ -575,10 +591,12 @@ do {									\
 	STAT_MSEG_MBC_ALLOC((AP), csz__);				\
     else								\
 	STAT_SYS_ALLOC_MBC_ALLOC((AP), csz__);				\
-    (AP)->mbcs.blocks.curr.no += (CRR)->cpool.blocks;			\
+    set_new_allctr_abandon_limit(AP);                                   \
+    (AP)->mbcs.blocks.curr.no += (CRR)->cpool.blocks[(AP)->alloc_no];   \
     if ((AP)->mbcs.blocks.max.no < (AP)->mbcs.blocks.curr.no)		\
 	(AP)->mbcs.blocks.max.no = (AP)->mbcs.blocks.curr.no;		\
-    (AP)->mbcs.blocks.curr.size += (CRR)->cpool.blocks_size;		\
+    (AP)->mbcs.blocks.curr.size +=                                      \
+       (CRR)->cpool.blocks_size[(AP)->alloc_no];                        \
     if ((AP)->mbcs.blocks.max.size < (AP)->mbcs.blocks.curr.size)	\
 	(AP)->mbcs.blocks.max.size = (AP)->mbcs.blocks.curr.size;	\
 } while (0)
@@ -601,25 +619,33 @@ do {									\
     DEBUG_CHECK_CARRIER_NO_SZ((AP));					\
 } while (0)
 
-#define STAT_MBC_ABANDON(AP, CRR)					\
-do {									\
-    UWord csz__ = CARRIER_SZ((CRR));					\
-    if (IS_MSEG_CARRIER((CRR)))						\
-	STAT_MSEG_MBC_FREE((AP), csz__);				\
-    else								\
-	STAT_SYS_ALLOC_MBC_FREE((AP), csz__);				\
-    ERTS_ALC_CPOOL_ASSERT((AP)->mbcs.blocks.curr.no			\
-			  >= (CRR)->cpool.blocks);			\
-    (AP)->mbcs.blocks.curr.no -= (CRR)->cpool.blocks;			\
-    ERTS_ALC_CPOOL_ASSERT((AP)->mbcs.blocks.curr.size 			\
-			  >= (CRR)->cpool.blocks_size);			\
-    (AP)->mbcs.blocks.curr.size -= (CRR)->cpool.blocks_size;		\
+#define STAT_MBC_FREE(AP, CRR)                                               \
+do {                                                                         \
+    UWord csz__ = CARRIER_SZ((CRR));                                         \
+    if (IS_MSEG_CARRIER((CRR))) {                                            \
+        STAT_MSEG_MBC_FREE((AP), csz__);                                     \
+    } else {                                                                 \
+        STAT_SYS_ALLOC_MBC_FREE((AP), csz__);                                \
+    }                                                                        \
+    set_new_allctr_abandon_limit(AP);                                        \
+} while (0)
+
+#define STAT_MBC_ABANDON(AP, CRR)                                            \
+do {                                                                         \
+    STAT_MBC_FREE(AP, CRR);                                                  \
+    ERTS_ALC_CPOOL_ASSERT((AP)->mbcs.blocks.curr.no                          \
+                          >= (CRR)->cpool.blocks[(AP)->alloc_no]);           \
+    (AP)->mbcs.blocks.curr.no -= (CRR)->cpool.blocks[(AP)->alloc_no];        \
+    ERTS_ALC_CPOOL_ASSERT((AP)->mbcs.blocks.curr.size                        \
+                          >= (CRR)->cpool.blocks_size[(AP)->alloc_no]);      \
+    (AP)->mbcs.blocks.curr.size -= (CRR)->cpool.blocks_size[(AP)->alloc_no]; \
 } while (0)
 
-#define STAT_MBC_BLK_ALLOC_CRR(CRR, BSZ)				\
+#define STAT_MBC_BLK_ALLOC_CRR(AP, CRR, BSZ)				\
 do {									\
-    (CRR)->cpool.blocks++;						\
-    (CRR)->cpool.blocks_size += (BSZ);					\
+    (CRR)->cpool.blocks[(AP)->alloc_no]++;				\
+    (CRR)->cpool.blocks_size[(AP)->alloc_no] += (BSZ);			\
+    (CRR)->cpool.total_blocks_size += (BSZ);				\
 } while (0)
 
 #define STAT_MBC_BLK_ALLOC(AP, CRR, BSZ, FLGS)	       			\
@@ -631,50 +657,67 @@ do {									\
     cstats__->blocks.curr.size += (BSZ);				\
     if (cstats__->blocks.max.size < cstats__->blocks.curr.size)		\
 	cstats__->blocks.max.size = cstats__->blocks.curr.size;		\
-    STAT_MBC_BLK_ALLOC_CRR((CRR), (BSZ));				\
+    STAT_MBC_BLK_ALLOC_CRR((AP), (CRR), (BSZ));				\
 } while (0)
 
 static ERTS_INLINE int
 stat_cpool_mbc_blk_free(Allctr_t *allctr,
+                        ErtsAlcType_t type,
 			Carrier_t *crr,
 			Carrier_t **busy_pcrr_pp,
 			UWord blksz)
 {
+    Allctr_t *orig_allctr;
+    int alloc_no;
 
-    ERTS_ALC_CPOOL_ASSERT(crr->cpool.blocks > 0);
-    crr->cpool.blocks--;
-    ERTS_ALC_CPOOL_ASSERT(crr->cpool.blocks_size >= blksz);
-    crr->cpool.blocks_size -= blksz;
+    alloc_no = ERTS_ALC_T2A(type);
 
-    if (!busy_pcrr_pp || !*busy_pcrr_pp)
-	return 0;
+    ERTS_ALC_CPOOL_ASSERT(crr->cpool.blocks[alloc_no] > 0);
+    crr->cpool.blocks[alloc_no]--;
+    ERTS_ALC_CPOOL_ASSERT(crr->cpool.blocks_size[alloc_no] >= blksz);
+    crr->cpool.blocks_size[alloc_no] -= blksz;
+    ERTS_ALC_CPOOL_ASSERT(crr->cpool.total_blocks_size >= blksz);
+    crr->cpool.total_blocks_size -= blksz;
+
+    if (allctr->alloc_no == alloc_no && (!busy_pcrr_pp || !*busy_pcrr_pp)) {
+        /* This is a local block, so we should not update the pool
+         * statistics. */
+        return 0;
+    }
+
+    /* This is either a foreign block that's been fetched from the pool, or any
+     * block that's in the pool. The carrier's owner keeps the statistics for
+     * both pooled and foreign blocks. */
+
+    orig_allctr = crr->cpool.orig_allctr;
 
-    ERTS_ALC_CPOOL_ASSERT(crr == *busy_pcrr_pp);
+    ERTS_ALC_CPOOL_ASSERT(alloc_no != allctr->alloc_no ||
+        (crr == *busy_pcrr_pp && allctr == orig_allctr));
 
 #ifdef ERTS_ALC_CPOOL_DEBUG
     ERTS_ALC_CPOOL_ASSERT(
-	erts_atomic_dec_read_nob(&allctr->cpool.stat.no_blocks) >= 0);
+	erts_atomic_dec_read_nob(&orig_allctr->cpool.stat.no_blocks[alloc_no]) >= 0);
     ERTS_ALC_CPOOL_ASSERT(
-	erts_atomic_add_read_nob(&allctr->cpool.stat.blocks_size,
+	erts_atomic_add_read_nob(&orig_allctr->cpool.stat.blocks_size[alloc_no],
 				 -((erts_aint_t) blksz)) >= 0);
 #else
-    erts_atomic_dec_nob(&allctr->cpool.stat.no_blocks);
-    erts_atomic_add_nob(&allctr->cpool.stat.blocks_size,
+    erts_atomic_dec_nob(&orig_allctr->cpool.stat.no_blocks[alloc_no]);
+    erts_atomic_add_nob(&orig_allctr->cpool.stat.blocks_size[alloc_no],
 			-((erts_aint_t) blksz));
 #endif
 
     return 1;
 }
 
-#define STAT_MBC_BLK_FREE(AP, CRR, BPCRRPP, BSZ, FLGS)			\
-do {									\
-    if (!stat_cpool_mbc_blk_free((AP), (CRR), (BPCRRPP), (BSZ))) {	\
-	CarriersStats_t *cstats__ = &(AP)->mbcs;			\
-	ASSERT(cstats__->blocks.curr.no > 0);				\
-	cstats__->blocks.curr.no--;					\
-	ASSERT(cstats__->blocks.curr.size >= (BSZ));			\
-	cstats__->blocks.curr.size -= (BSZ);				\
-    }									\
+#define STAT_MBC_BLK_FREE(AP, TYPE, CRR, BPCRRPP, BSZ, FLGS)               \
+do {                                                                       \
+    if (!stat_cpool_mbc_blk_free((AP), (TYPE), (CRR), (BPCRRPP), (BSZ))) { \
+        CarriersStats_t *cstats__ = &(AP)->mbcs;                           \
+        ASSERT(cstats__->blocks.curr.no > 0);                              \
+        cstats__->blocks.curr.no--;                                        \
+        ASSERT(cstats__->blocks.curr.size >= (BSZ));                       \
+        cstats__->blocks.curr.size -= (BSZ);                               \
+    }                                                                      \
 } while (0)
 
 /* Debug stuff... */
@@ -721,8 +764,8 @@ static void make_name_atoms(Allctr_t *allctr);
 
 static Block_t *create_carrier(Allctr_t *, Uint, UWord);
 static void destroy_carrier(Allctr_t *, Block_t *, Carrier_t **);
-static void mbc_free(Allctr_t *allctr, void *p, Carrier_t **busy_pcrr_pp);
-static void dealloc_block(Allctr_t *, void *, ErtsAlcFixList_t *, int);
+static void mbc_free(Allctr_t *allctr, ErtsAlcType_t type, void *p, Carrier_t **busy_pcrr_pp);
+static void dealloc_block(Allctr_t *, ErtsAlcType_t, Uint32, void *, ErtsAlcFixList_t *);
 
 static alcu_atag_t determine_alloc_tag(Allctr_t *allocator, ErtsAlcType_t type)
 {
@@ -764,14 +807,14 @@ static alcu_atag_t determine_alloc_tag(Allctr_t *allocator, ErtsAlcType_t type)
         }
     }
 
-    return MAKE_ATAG(id, type);
+    return MAKE_ATAG(id, ERTS_ALC_T2N(type));
 }
 
 static void set_alloc_tag(Allctr_t *allocator, void *p, alcu_atag_t tag)
 {
     Block_t *block;
 
-    ASSERT(DBG_IS_VALID_ATAG(allocator, tag));
+    ASSERT(DBG_IS_VALID_ATAG(tag));
     ASSERT(allocator->atags && p);
     (void)allocator;
 
@@ -1312,28 +1355,9 @@ chk_fix_list(Allctr_t *allctr, ErtsAlcFixList_t *fix, int ix, int before)
 #define ERTS_DBG_CHK_FIX_LIST(A, FIX, IX, B)
 #endif
 
+static ERTS_INLINE Allctr_t *get_pref_allctr(void *extra);
 static void *mbc_alloc(Allctr_t *allctr, Uint size);
 
-typedef struct {
-    ErtsAllctrDDBlock_t ddblock__; /* must be first */
-    ErtsAlcType_t fix_type;
-} ErtsAllctrFixDDBlock_t;
-
-#define ERTS_ALC_FIX_NO_UNUSE (((ErtsAlcType_t) 1) << ERTS_ALC_N_BITS)
-
-static ERTS_INLINE void
-dealloc_fix_block(Allctr_t *allctr,
-		  ErtsAlcType_t type,
-		  void *ptr,
-		  ErtsAlcFixList_t *fix,
-		  int dec_cc_on_redirect)
-{
-    /* May be redirected... */
-    ASSERT((type & ERTS_ALC_FIX_NO_UNUSE) == 0);
-    ((ErtsAllctrFixDDBlock_t *) ptr)->fix_type = type | ERTS_ALC_FIX_NO_UNUSE;
-    dealloc_block(allctr, ptr, fix, dec_cc_on_redirect);
-}
-
 static ERTS_INLINE void
 sched_fix_shrink(Allctr_t *allctr, int on)
 {
@@ -1375,7 +1399,7 @@ fix_cpool_check_shrink(Allctr_t *allctr,
 	    if (fix->u.cpool.min_list_size > fix->list_size)
 		fix->u.cpool.min_list_size = fix->list_size;
 
-	    dealloc_fix_block(allctr, type, p, fix, 0);
+	    dealloc_block(allctr, type, DEALLOC_FLG_FIX_SHRINK, p, fix);
 	}
     }
 }
@@ -1386,11 +1410,9 @@ fix_cpool_alloc(Allctr_t *allctr, ErtsAlcType_t type, Uint size)
     void *res;
     ErtsAlcFixList_t *fix;
 
-    ASSERT(ERTS_ALC_N_MIN_A_FIXED_SIZE <= type
-	   && type <= ERTS_ALC_N_MAX_A_FIXED_SIZE);
-
-    fix = &allctr->fix[type - ERTS_ALC_N_MIN_A_FIXED_SIZE];
-    ASSERT(size == fix->type_size);
+    fix = &allctr->fix[ERTS_ALC_FIX_TYPE_IX(type)];
+    ASSERT(type == fix->type && size == fix->type_size);
+    ASSERT(size >= sizeof(ErtsAllctrDDBlock_t));
 
     res = fix->list;
     if (res) {
@@ -1419,21 +1441,39 @@ fix_cpool_alloc(Allctr_t *allctr, ErtsAlcType_t type, Uint size)
 static ERTS_INLINE void
 fix_cpool_free(Allctr_t *allctr,
 	       ErtsAlcType_t type,
+               Uint32 flags,
 	       void *p,
-	       Carrier_t **busy_pcrr_pp,
-	       int unuse)
+	       Carrier_t **busy_pcrr_pp)
 {
     ErtsAlcFixList_t *fix;
+    Allctr_t *fix_allctr;
+
+    /* If this isn't a fix allocator we need to update the fix list of our
+     * neighboring fix_alloc to keep the statistics consistent. */
+    if (!allctr->fix) {
+        ErtsAllocatorThrSpec_t *tspec = &erts_allctr_thr_spec[ERTS_ALC_A_FIXED_SIZE];
+        fix_allctr = get_pref_allctr(tspec);
+        ASSERT(!fix_allctr->thread_safe);
+        ASSERT(allctr != fix_allctr);
+    }
+    else {
+        fix_allctr = allctr;
+    }
 
-    ASSERT(ERTS_ALC_N_MIN_A_FIXED_SIZE <= type
-	   && type <= ERTS_ALC_N_MAX_A_FIXED_SIZE);
+    ASSERT(ERTS_ALC_IS_CPOOL_ENABLED(fix_allctr));
+    ASSERT(ERTS_ALC_IS_CPOOL_ENABLED(allctr));
 
-    fix = &allctr->fix[type - ERTS_ALC_N_MIN_A_FIXED_SIZE];
+    fix = &fix_allctr->fix[ERTS_ALC_FIX_TYPE_IX(type)];
+    ASSERT(type == fix->type);
 
-    if (unuse)
-	fix->u.cpool.used--;
+    if (!(flags & DEALLOC_FLG_FIX_SHRINK)) {
+        fix->u.cpool.used--;
+    }
 
-    if ((!busy_pcrr_pp || !*busy_pcrr_pp)
+    /* We don't want foreign blocks to be long-lived, so we skip recycling if
+     * allctr != fix_allctr. */
+    if (allctr == fix_allctr
+        && (!busy_pcrr_pp || !*busy_pcrr_pp)
 	&& !fix->u.cpool.shrink_list
 	&& fix->list_size < ERTS_ALCU_FIX_MAX_LIST_SZ) {
 	*((void **) p) = fix->list;
@@ -1446,7 +1486,7 @@ fix_cpool_free(Allctr_t *allctr,
 	if (IS_SBC_BLK(blk))
 	    destroy_carrier(allctr, blk, NULL);
 	else
-	    mbc_free(allctr, p, busy_pcrr_pp);
+	    mbc_free(allctr, type, p, busy_pcrr_pp);
 	fix->u.cpool.allocated--;
 	fix_cpool_check_shrink(allctr, type, fix, busy_pcrr_pp);
     }
@@ -1473,7 +1513,7 @@ fix_cpool_alloc_shrink(Allctr_t *allctr, erts_aint32_t flgs)
 	    fix->u.cpool.shrink_list = fix->u.cpool.min_list_size;
 	    fix->u.cpool.min_list_size = fix->list_size;
 	}
-	type = (ErtsAlcType_t) (ix + ERTS_ALC_N_MIN_A_FIXED_SIZE);
+	type = ERTS_ALC_N2T((ErtsAlcType_t) (ix + ERTS_ALC_N_MIN_A_FIXED_SIZE));
 	for (o = 0; o < ERTS_ALC_FIX_MAX_SHRINK_OPS || flush; o++) {
 	    void *ptr;
 
@@ -1487,7 +1527,7 @@ fix_cpool_alloc_shrink(Allctr_t *allctr, erts_aint32_t flgs)
 	    fix->list = *((void **) ptr);
 	    fix->list_size--;
 	    fix->u.cpool.shrink_list--;
-	    dealloc_fix_block(allctr, type, ptr, fix, 0);
+	    dealloc_block(allctr, type, DEALLOC_FLG_FIX_SHRINK, ptr, fix);
 	}
 	if (fix->u.cpool.min_list_size > fix->list_size)
 	    fix->u.cpool.min_list_size = fix->list_size;
@@ -1513,11 +1553,9 @@ fix_nocpool_alloc(Allctr_t *allctr, ErtsAlcType_t type, Uint size)
     ErtsAlcFixList_t *fix;
     void *res;
 
-    ASSERT(ERTS_ALC_N_MIN_A_FIXED_SIZE <= type
-	   && type <= ERTS_ALC_N_MAX_A_FIXED_SIZE);
-
-    fix = &allctr->fix[type - ERTS_ALC_N_MIN_A_FIXED_SIZE];
-    ASSERT(size == fix->type_size);
+    fix = &allctr->fix[ERTS_ALC_FIX_TYPE_IX(type)];
+    ASSERT(type == fix->type && size == fix->type_size);
+    ASSERT(size >= sizeof(ErtsAllctrDDBlock_t));
 
     ERTS_DBG_CHK_FIX_LIST(allctr, fix, ix, 1);
     fix->u.nocpool.used++;
@@ -1534,7 +1572,7 @@ fix_nocpool_alloc(Allctr_t *allctr, ErtsAlcType_t type, Uint size)
 	    if (IS_SBC_BLK(blk))
 		destroy_carrier(allctr, blk, NULL);
 	    else
-		mbc_free(allctr, p, NULL);
+		mbc_free(allctr, type, p, NULL);
 	    fix->u.nocpool.allocated--;
 	}
 	ERTS_DBG_CHK_FIX_LIST(allctr, fix, ix, 0);
@@ -1569,10 +1607,8 @@ fix_nocpool_free(Allctr_t *allctr,
     Block_t *blk;
     ErtsAlcFixList_t *fix;
 
-    ASSERT(ERTS_ALC_N_MIN_A_FIXED_SIZE <= type
-	   && type <= ERTS_ALC_N_MAX_A_FIXED_SIZE);
-
-    fix = &allctr->fix[type - ERTS_ALC_N_MIN_A_FIXED_SIZE];
+    fix = &allctr->fix[ERTS_ALC_T2N(type) - ERTS_ALC_N_MIN_A_FIXED_SIZE];
+    ASSERT(fix->type == type);
 
     ERTS_DBG_CHK_FIX_LIST(allctr, fix, ix, 1);
     fix->u.nocpool.used--;
@@ -1591,7 +1627,7 @@ fix_nocpool_free(Allctr_t *allctr,
 	if (IS_SBC_BLK(blk))
 	    destroy_carrier(allctr, blk, NULL);
 	else
-	    mbc_free(allctr, p, NULL);
+	    mbc_free(allctr, type, p, NULL);
 	p = fix->list;
 	fix->list = *((void **) p);
 	fix->list_size--;
@@ -1602,7 +1638,7 @@ fix_nocpool_free(Allctr_t *allctr,
     if (IS_SBC_BLK(blk))
 	destroy_carrier(allctr, blk, NULL);
     else
-	mbc_free(allctr, p, NULL);
+	mbc_free(allctr, type, p, NULL);
     ERTS_DBG_CHK_FIX_LIST(allctr, fix, ix, 0);
 }
 
@@ -1643,7 +1679,7 @@ fix_nocpool_alloc_shrink(Allctr_t *allctr, erts_aint32_t flgs)
 	    ptr = fix->list;
 	    fix->list = *((void **) ptr);
 	    fix->list_size--;
-	    dealloc_block(allctr, ptr, NULL, 0);
+	    dealloc_block(allctr, fix->type, 0, ptr, NULL);
 	    fix->u.nocpool.allocated--;
 	}
 	if (fix->list_size != 0) {
@@ -1685,6 +1721,7 @@ dealloc_mbc(Allctr_t *allctr, Carrier_t *crr)
 }
 
 
+static UWord allctr_abandon_limit(Allctr_t *allctr);
 static void set_new_allctr_abandon_limit(Allctr_t*);
 static void abandon_carrier(Allctr_t*, Carrier_t*);
 static void poolify_my_carrier(Allctr_t*, Carrier_t*);
@@ -1806,7 +1843,7 @@ get_used_allctr(Allctr_t *pref_allctr, int pref_lock, void *p, UWord *sizep,
 static void
 init_dd_queue(ErtsAllctrDDQueue_t *ddq)
 {
-    erts_atomic_init_nob(&ddq->tail.data.marker.atmc_next, ERTS_AINT_NULL);
+    erts_atomic_init_nob(&ddq->tail.data.marker.u.atmc_next, ERTS_AINT_NULL);
     erts_atomic_init_nob(&ddq->tail.data.last,
 			 (erts_aint_t) &ddq->tail.data.marker);
     erts_atomic_init_nob(&ddq->tail.data.um_refc[0], 0);
@@ -1827,17 +1864,17 @@ ddq_managed_thread_enqueue(ErtsAllctrDDQueue_t *ddq, void *ptr, int cinit)
     erts_aint_t itmp;
     ErtsAllctrDDBlock_t *enq, *this = ptr;
 
-    erts_atomic_init_nob(&this->atmc_next, ERTS_AINT_NULL);
+    erts_atomic_init_nob(&this->u.atmc_next, ERTS_AINT_NULL);
     /* Enqueue at end of list... */
 
     enq = (ErtsAllctrDDBlock_t *) erts_atomic_read_nob(&ddq->tail.data.last);
-    itmp = erts_atomic_cmpxchg_relb(&enq->atmc_next,
+    itmp = erts_atomic_cmpxchg_relb(&enq->u.atmc_next,
 				    (erts_aint_t) this,
 				    ERTS_AINT_NULL);
     if (itmp == ERTS_AINT_NULL) {
 	/* We are required to move last pointer */
 #ifdef DEBUG
-	ASSERT(ERTS_AINT_NULL == erts_atomic_read_nob(&this->atmc_next));
+	ASSERT(ERTS_AINT_NULL == erts_atomic_read_nob(&this->u.atmc_next));
 	ASSERT(((erts_aint_t) enq)
 	       == erts_atomic_xchg_relb(&ddq->tail.data.last,
 					(erts_aint_t) this));
@@ -1855,8 +1892,8 @@ ddq_managed_thread_enqueue(ErtsAllctrDDQueue_t *ddq, void *ptr, int cinit)
 
 	while (1) {
 	    erts_aint_t itmp2;
-	    erts_atomic_set_nob(&this->atmc_next, itmp);
-	    itmp2 = erts_atomic_cmpxchg_relb(&enq->atmc_next,
+	    erts_atomic_set_nob(&this->u.atmc_next, itmp);
+	    itmp2 = erts_atomic_cmpxchg_relb(&enq->u.atmc_next,
 					     (erts_aint_t) this,
 					     itmp);
 	    if (itmp == itmp2)
@@ -1865,7 +1902,7 @@ ddq_managed_thread_enqueue(ErtsAllctrDDQueue_t *ddq, void *ptr, int cinit)
 		itmp = itmp2;
 	    else {
 		enq = (ErtsAllctrDDBlock_t *) itmp2;
-		itmp = erts_atomic_read_acqb(&enq->atmc_next);
+		itmp = erts_atomic_read_acqb(&enq->u.atmc_next);
 		ASSERT(itmp != ERTS_AINT_NULL);
 	    }
 	    i++;
@@ -1881,8 +1918,8 @@ check_insert_marker(ErtsAllctrDDQueue_t *ddq, erts_aint_t ilast)
 	erts_aint_t itmp;
 	ErtsAllctrDDBlock_t *last = (ErtsAllctrDDBlock_t *) ilast;
 
-	erts_atomic_init_nob(&ddq->tail.data.marker.atmc_next, ERTS_AINT_NULL);
-	itmp = erts_atomic_cmpxchg_relb(&last->atmc_next,
+	erts_atomic_init_nob(&ddq->tail.data.marker.u.atmc_next, ERTS_AINT_NULL);
+	itmp = erts_atomic_cmpxchg_relb(&last->u.atmc_next,
 					(erts_aint_t) &ddq->tail.data.marker,
 					ERTS_AINT_NULL);
 	if (itmp == ERTS_AINT_NULL) {
@@ -1933,7 +1970,7 @@ ddq_dequeue(ErtsAllctrDDQueue_t *ddq)
 	ASSERT(ddq->head.used_marker);
 	ddq->head.used_marker = 0;
 	blk = ((ErtsAllctrDDBlock_t *)
-	       erts_atomic_read_nob(&blk->atmc_next));
+	       erts_atomic_read_nob(&blk->u.atmc_next));
 	if (blk == ddq->head.unref_end) {
 	    ddq->head.first = blk;
 	    return NULL;
@@ -1941,7 +1978,7 @@ ddq_dequeue(ErtsAllctrDDQueue_t *ddq)
     }
 
     ddq->head.first = ((ErtsAllctrDDBlock_t *)
-		       erts_atomic_read_nob(&blk->atmc_next));
+		       erts_atomic_read_nob(&blk->u.atmc_next));
 
     ASSERT(ddq->head.first);
 
@@ -2003,19 +2040,13 @@ check_pending_dealloc_carrier(Allctr_t *allctr,
 			      int *need_more_work);
 
 static void
-handle_delayed_fix_dealloc(Allctr_t *allctr, void *ptr)
+handle_delayed_fix_dealloc(Allctr_t *allctr, ErtsAlcType_t type, Uint32 flags,
+                           void *ptr)
 {
-    ErtsAlcType_t type;
-
-    type = ((ErtsAllctrFixDDBlock_t *) ptr)->fix_type;
-
-    ASSERT(ERTS_ALC_N_MIN_A_FIXED_SIZE
-	   <= (type & ~ERTS_ALC_FIX_NO_UNUSE));
-    ASSERT((type & ~ERTS_ALC_FIX_NO_UNUSE)
-	   <= ERTS_ALC_N_MAX_A_FIXED_SIZE);
+    ASSERT(ERTS_ALC_IS_FIX_TYPE(type));
 
     if (!ERTS_ALC_IS_CPOOL_ENABLED(allctr))
-	fix_nocpool_free(allctr, (type & ~ERTS_ALC_FIX_NO_UNUSE), ptr);
+	fix_nocpool_free(allctr, type, ptr);
     else {
 	Block_t *blk = UMEM2BLK(ptr);
 	Carrier_t *busy_pcrr_p;
@@ -2030,20 +2061,24 @@ handle_delayed_fix_dealloc(Allctr_t *allctr, void *ptr)
 				      NULL, &busy_pcrr_p);
 	if (used_allctr == allctr) {
 	doit:
-	    fix_cpool_free(allctr, (type & ~ERTS_ALC_FIX_NO_UNUSE),
-			   ptr, &busy_pcrr_p,
-			   !(type & ERTS_ALC_FIX_NO_UNUSE));
+	    fix_cpool_free(allctr, type, flags, ptr, &busy_pcrr_p);
 	    clear_busy_pool_carrier(allctr, busy_pcrr_p);
 	}
 	else {
 	    /* Carrier migrated; need to redirect block to new owner... */
-	    int cinit = used_allctr->dd.ix - allctr->dd.ix;
+            ErtsAllctrDDBlock_t *dd_block;
+            int cinit;
+
+            dd_block = (ErtsAllctrDDBlock_t*)ptr;
+            dd_block->flags = flags;
+            dd_block->type = type;
 
             ERTS_ALC_CPOOL_ASSERT(!busy_pcrr_p);
 
             DEC_CC(allctr->calls.this_free);
 
-	    ((ErtsAllctrFixDDBlock_t *) ptr)->fix_type = type;
+            cinit = used_allctr->dd.ix - allctr->dd.ix;
+
 	    if (ddq_enqueue(&used_allctr->dd.q, ptr, cinit))
 		erts_alloc_notify_delayed_dealloc(used_allctr->ix);
 	}
@@ -2067,7 +2102,6 @@ handle_delayed_dealloc(Allctr_t *allctr,
     int need_mr_wrk = 0;
     int have_checked_incoming = 0;
     int ops = 0;
-    ErtsAlcFixList_t *fix;
     int res;
     ErtsAllctrDDQueue_t *ddq;
 
@@ -2076,8 +2110,6 @@ handle_delayed_dealloc(Allctr_t *allctr,
 
     ERTS_ALCU_DBG_CHK_THR_ACCESS(allctr);
 
-    fix = allctr->fix;
-
     ddq = &allctr->dd.q;
 
     res = 0;
@@ -2166,16 +2198,27 @@ handle_delayed_dealloc(Allctr_t *allctr,
             }
 	}
 	else {
+            ErtsAllctrDDBlock_t *dd_block;
+            ErtsAlcType_t type;
+            Uint32 flags;
+        
+            dd_block = (ErtsAllctrDDBlock_t*)ptr;
+            flags = dd_block->flags;
+            type = dd_block->type;
+
+            flags |= DEALLOC_FLG_REDIRECTED;
+
             ASSERT(IS_SBC_BLK(blk) || (ABLK_TO_MBC(blk) !=
                                        ErtsContainerStruct(blk, Carrier_t,
                                                            cpool.homecoming_dd.blk)));
 
 	    INC_CC(allctr->calls.this_free);
 
-	    if (fix)
-		handle_delayed_fix_dealloc(allctr, ptr);
-	    else
-		dealloc_block(allctr, ptr, NULL, 1);
+	    if (ERTS_ALC_IS_FIX_TYPE(type)) {
+		handle_delayed_fix_dealloc(allctr, type, flags, ptr);
+	    } else {
+		dealloc_block(allctr, type, flags, ptr, NULL);
+            }
 	}
     }
 
@@ -2203,8 +2246,10 @@ enqueue_dealloc_other_instance(ErtsAlcType_t type,
 			       void *ptr,
 			       int cinit)
 {
-    if (allctr->fix)
-	((ErtsAllctrFixDDBlock_t*) ptr)->fix_type = type;
+    ErtsAllctrDDBlock_t *dd_block = ((ErtsAllctrDDBlock_t*)ptr);
+
+    dd_block->type = type;
+    dd_block->flags = 0;
 
     if (ddq_enqueue(&allctr->dd.q, ptr, cinit))
 	erts_alloc_notify_delayed_dealloc(allctr->ix);
@@ -2234,10 +2279,7 @@ check_abandon_carrier(Allctr_t *allctr, Block_t *fblk, Carrier_t **busy_pcrr_pp)
     if (!ERTS_ALC_IS_CPOOL_ENABLED(allctr))
 	return;
 
-    allctr->cpool.check_limit_count--;
-    if (--allctr->cpool.check_limit_count <= 0)
-	set_new_allctr_abandon_limit(allctr);
-
+    ASSERT(allctr->cpool.abandon_limit == allctr_abandon_limit(allctr));
     ASSERT(erts_thr_progress_is_managed_thread());
 
     if (allctr->cpool.disable_abandon)
@@ -2255,7 +2297,7 @@ check_abandon_carrier(Allctr_t *allctr, Block_t *fblk, Carrier_t **busy_pcrr_pp)
     if (allctr->main_carrier == crr)
 	return;
 
-    if (crr->cpool.blocks_size > crr->cpool.abandon_limit)
+    if (crr->cpool.total_blocks_size > crr->cpool.abandon_limit)
 	return;
 
     if (crr->cpool.thr_prgr != ERTS_THR_PRGR_INVALID
@@ -2291,24 +2333,26 @@ erts_alcu_check_delayed_dealloc(Allctr_t *allctr,
 			   ERTS_ALCU_DD_OPS_LIM_LOW, NULL, NULL, NULL)
 
 static void
-dealloc_block(Allctr_t *allctr, void *ptr, ErtsAlcFixList_t *fix, int dec_cc_on_redirect)
+dealloc_block(Allctr_t *allctr, ErtsAlcType_t type, Uint32 flags, void *ptr,
+              ErtsAlcFixList_t *fix)
 {
     Block_t *blk = UMEM2BLK(ptr);
 
+    ASSERT(!fix || type == fix->type);
+
     ERTS_LC_ASSERT(!allctr->thread_safe
 		       || erts_lc_mtx_is_locked(&allctr->mutex));
 
     if (IS_SBC_BLK(blk)) {
 	destroy_carrier(allctr, blk, NULL);
 	if (fix && ERTS_ALC_IS_CPOOL_ENABLED(allctr)) {
-	    ErtsAlcType_t type = ((ErtsAllctrFixDDBlock_t *) ptr)->fix_type;
-	    if (!(type & ERTS_ALC_FIX_NO_UNUSE))
+	    if (!(flags & DEALLOC_FLG_FIX_SHRINK))
 		fix->u.cpool.used--;
 	    fix->u.cpool.allocated--;
 	}
     }
     else if (!ERTS_ALC_IS_CPOOL_ENABLED(allctr))
-	mbc_free(allctr, ptr, NULL);
+	mbc_free(allctr, type, ptr, NULL);
     else {
 	Carrier_t *busy_pcrr_p;
 	Allctr_t *used_allctr;
@@ -2317,22 +2361,29 @@ dealloc_block(Allctr_t *allctr, void *ptr, ErtsAlcFixList_t *fix, int dec_cc_on_
 				      NULL, &busy_pcrr_p);
 	if (used_allctr == allctr) {
 	    if (fix) {
-		ErtsAlcType_t type = ((ErtsAllctrFixDDBlock_t *) ptr)->fix_type;
-		if (!(type & ERTS_ALC_FIX_NO_UNUSE))
+	        if (!(flags & DEALLOC_FLG_FIX_SHRINK))
 		    fix->u.cpool.used--;
 		fix->u.cpool.allocated--;
 	    }
-	    mbc_free(allctr, ptr, &busy_pcrr_p);
+	    mbc_free(allctr, type, ptr, &busy_pcrr_p);
 	    clear_busy_pool_carrier(allctr, busy_pcrr_p);
 	}
 	else {
 	    /* Carrier migrated; need to redirect block to new owner... */
-	    int cinit = used_allctr->dd.ix - allctr->dd.ix;
+            ErtsAllctrDDBlock_t *dd_block;
+            int cinit;
+
+            dd_block = (ErtsAllctrDDBlock_t*)ptr;
+            dd_block->flags = flags;
+            dd_block->type = type;
 
             ERTS_ALC_CPOOL_ASSERT(!busy_pcrr_p);
 
-            if (dec_cc_on_redirect)
+            if (flags & DEALLOC_FLG_REDIRECTED)
                 DEC_CC(allctr->calls.this_free);
+
+            cinit = used_allctr->dd.ix - allctr->dd.ix;
+
 	    if (ddq_enqueue(&used_allctr->dd.q, ptr, cinit))
 		erts_alloc_notify_delayed_dealloc(used_allctr->ix);
 	}
@@ -2498,9 +2549,155 @@ mbc_alloc(Allctr_t *allctr, Uint size)
     return BLK2UMEM(blk);
 }
 
+typedef struct {
+    char *ptr;
+    UWord size;
+} ErtsMemDiscardRegion;
+
+/* Construct a discard region for the user memory of a free block, letting the
+ * OS reclaim its physical memory when required.
+ *
+ * Note that we're ignoring both the footer and everything that comes before
+ * the minimum block size as the allocator uses those areas to manage the
+ * block. */
+static void ERTS_INLINE
+mem_discard_start(Allctr_t *allocator, Block_t *block,
+                  ErtsMemDiscardRegion *out)
+{
+    UWord size = BLK_SZ(block);
+
+    ASSERT(size >= allocator->min_block_size);
+
+    if (size > (allocator->min_block_size + FBLK_FTR_SZ)) {
+        out->size = size - allocator->min_block_size - FBLK_FTR_SZ;
+    } else {
+        out->size = 0;
+    }
+
+    out->ptr = (char*)block + allocator->min_block_size;
+}
+
+/* Expands a discard region into a neighboring free block, allowing us to
+ * discard the block header and first page.
+ *
+ * This is very important in small-allocation scenarios where no single block
+ * is large enough to be discarded on its own. */
+static void ERTS_INLINE
+mem_discard_coalesce(Allctr_t *allocator, Block_t *neighbor,
+                     ErtsMemDiscardRegion *region)
+{
+    char *neighbor_start;
+
+    ASSERT(IS_FREE_BLK(neighbor));
+
+    neighbor_start = (char*)neighbor;
+
+    if (region->ptr >= neighbor_start) {
+        char *region_start_page;
+
+        region_start_page = region->ptr - SYS_PAGE_SIZE;
+        region_start_page = (char*)((UWord)region_start_page & ~SYS_PAGE_SZ_MASK);
+
+        /* Expand if our first page begins within the previous free block's
+         * unused data. */
+        if (region_start_page >= (neighbor_start + allocator->min_block_size)) {
+            region->size += (region->ptr - region_start_page) - FBLK_FTR_SZ;
+            region->ptr = region_start_page;
+        }
+    } else {
+        char *region_end_page;
+        UWord neighbor_size;
+
+        ASSERT(region->ptr <= neighbor_start);
+
+        region_end_page = region->ptr + region->size + SYS_PAGE_SIZE;
+        region_end_page = (char*)((UWord)region_end_page & ~SYS_PAGE_SZ_MASK);
+
+        neighbor_size = BLK_SZ(neighbor) - FBLK_FTR_SZ;
+
+        /* Expand if our last page ends anywhere within the next free block,
+         * sans the footer we'll inherit. */
+        if (region_end_page < neighbor_start + neighbor_size) {
+            region->size += region_end_page - (region->ptr + region->size);
+        }
+    }
+}
+
+static void ERTS_INLINE
+mem_discard_finish(Allctr_t *allocator, Block_t *block,
+                   ErtsMemDiscardRegion *region)
+{
+#ifdef DEBUG
+    char *block_start, *block_end;
+    UWord block_size;
+
+    block_size = BLK_SZ(block);
+
+    /* Ensure that the region is completely covered by the legal area of the
+     * free block. This must hold even when the region is too small to be
+     * discarded. */
+    if (region->size > 0) {
+        ASSERT(block_size > allocator->min_block_size + FBLK_FTR_SZ);
+
+        block_start = (char*)block + allocator->min_block_size;
+        block_end = (char*)block + block_size - FBLK_FTR_SZ;
+
+        ASSERT(region->size == 0 ||
+            (region->ptr + region->size <= block_end &&
+             region->ptr >= block_start &&
+             region->size <= block_size));
+    }
+#else
+    (void)allocator;
+    (void)block;
+#endif
+
+    if (region->size > SYS_PAGE_SIZE) {
+        UWord align_offset, size;
+        char *ptr;
+
+        align_offset = SYS_PAGE_SIZE - ((UWord)region->ptr & SYS_PAGE_SZ_MASK);
+
+        size = (region->size - align_offset) & ~SYS_PAGE_SZ_MASK;
+        ptr = region->ptr + align_offset;
+
+        if (size > 0) {
+            ASSERT(!((UWord)ptr & SYS_PAGE_SZ_MASK));
+            ASSERT(!(size & SYS_PAGE_SZ_MASK));
+
+            erts_mem_discard(ptr, size);
+        }
+    }
+}
+
 static void
-mbc_free(Allctr_t *allctr, void *p, Carrier_t **busy_pcrr_pp)
+carrier_mem_discard_free_blocks(Allctr_t *allocator, Carrier_t *carrier)
 {
+    static const int MAX_BLOCKS_TO_DISCARD = 100;
+    Block_t *block;
+    int i;
+
+    block = allocator->first_fblk_in_mbc(allocator, carrier);
+    i = 0;
+
+    while (block != NULL && i < MAX_BLOCKS_TO_DISCARD) {
+        ErtsMemDiscardRegion region;
+
+        ASSERT(IS_FREE_BLK(block));
+
+        mem_discard_start(allocator, block, &region);
+        mem_discard_finish(allocator, block, &region);
+
+        block = allocator->next_fblk_in_mbc(allocator, carrier, block);
+        i++;
+    }
+}
+
+static void
+mbc_free(Allctr_t *allctr, ErtsAlcType_t type, void *p, Carrier_t **busy_pcrr_pp)
+{
+    ErtsMemDiscardRegion discard_region = {0};
+    int discard;
     Uint is_first_blk;
     Uint is_last_blk;
     Uint blk_sz;
@@ -2516,12 +2713,28 @@ mbc_free(Allctr_t *allctr, void *p, Carrier_t **busy_pcrr_pp)
     ASSERT(IS_MBC_BLK(blk));
     ASSERT(blk_sz >= allctr->min_block_size);
 
+#ifndef DEBUG
+    /* We want to mark freed blocks as reclaimable to the OS, but it's a fairly
+     * expensive operation which doesn't do much good if we use it again soon
+     * after, so we limit it to deallocations on pooled carriers. */
+    discard = busy_pcrr_pp && *busy_pcrr_pp;
+#else
+    /* Always discard in debug mode, regardless of whether we're in the pool or
+     * not. */
+    discard = 1;
+#endif
+
+    if (discard) {
+        mem_discard_start(allctr, blk, &discard_region);
+    }
+
     HARD_CHECK_BLK_CARRIER(allctr, blk);
 
     crr = ABLK_TO_MBC(blk);
 
     ERTS_ALC_CPOOL_FREE_OP(allctr);
-    STAT_MBC_BLK_FREE(allctr, crr, busy_pcrr_pp, blk_sz, alcu_flgs);
+
+    STAT_MBC_BLK_FREE(allctr, type, crr, busy_pcrr_pp, blk_sz, alcu_flgs);
 
     is_first_blk = IS_MBC_FIRST_ABLK(allctr, blk);
     is_last_blk = IS_LAST_BLK(blk);
@@ -2532,6 +2745,10 @@ mbc_free(Allctr_t *allctr, void *p, Carrier_t **busy_pcrr_pp)
 	blk = PREV_BLK(blk);
 	(*allctr->unlink_free_block)(allctr, blk);
 
+        if (discard) {
+            mem_discard_coalesce(allctr, blk, &discard_region);
+        }
+
 	blk_sz += MBC_FBLK_SZ(blk);
 	is_first_blk = IS_MBC_FIRST_FBLK(allctr, blk);
 	SET_MBC_FBLK_SZ(blk, blk_sz);
@@ -2547,6 +2764,11 @@ mbc_free(Allctr_t *allctr, void *p, Carrier_t **busy_pcrr_pp)
 	if (IS_FREE_BLK(nxt_blk)) {
 	    /* Coalesce with next block... */
 	    (*allctr->unlink_free_block)(allctr, nxt_blk);
+
+            if (discard) {
+                mem_discard_coalesce(allctr, nxt_blk, &discard_region);
+            }
+
 	    blk_sz += MBC_FBLK_SZ(nxt_blk);
 	    SET_MBC_FBLK_SZ(blk, blk_sz);
 
@@ -2582,16 +2804,22 @@ mbc_free(Allctr_t *allctr, void *p, Carrier_t **busy_pcrr_pp)
     else {
 	(*allctr->link_free_block)(allctr, blk);
 	HARD_CHECK_BLK_CARRIER(allctr, blk);
-        if (busy_pcrr_pp && *busy_pcrr_pp)
+
+        if (discard) {
+            mem_discard_finish(allctr, blk, &discard_region);
+        }
+
+        if (busy_pcrr_pp && *busy_pcrr_pp) {
             update_pooled_tree(allctr, crr, blk_sz);
-        else
+        } else {
             check_abandon_carrier(allctr, blk, busy_pcrr_pp);
+        }
     }
 }
 
 static void *
-mbc_realloc(Allctr_t *allctr, void *p, Uint size, Uint32 alcu_flgs,
-	    Carrier_t **busy_pcrr_pp)
+mbc_realloc(Allctr_t *allctr, ErtsAlcType_t type, void *p, Uint size,
+            Uint32 alcu_flgs, Carrier_t **busy_pcrr_pp)
 {
     void *new_p;
     Uint old_blk_sz;
@@ -2629,7 +2857,7 @@ mbc_realloc(Allctr_t *allctr, void *p, Uint size, Uint32 alcu_flgs,
         new_blk = UMEM2BLK(new_p);
         ASSERT(!(IS_MBC_BLK(new_blk) && ABLK_TO_MBC(new_blk) == *busy_pcrr_pp));
         sys_memcpy(new_p, p, MIN(size, old_blk_sz - ABLK_HDR_SZ));
-        mbc_free(allctr, p, busy_pcrr_pp);
+        mbc_free(allctr, type, p, busy_pcrr_pp);
         return new_p;
     }
 
@@ -2706,7 +2934,7 @@ mbc_realloc(Allctr_t *allctr, void *p, Uint size, Uint32 alcu_flgs,
 	crr = ABLK_TO_MBC(blk);
 
 	ERTS_ALC_CPOOL_REALLOC_OP(allctr);
-	STAT_MBC_BLK_FREE(allctr, crr, NULL, old_blk_sz, alcu_flgs);
+	STAT_MBC_BLK_FREE(allctr, type, crr, NULL, old_blk_sz, alcu_flgs);
 	STAT_MBC_BLK_ALLOC(allctr, crr, blk_sz, alcu_flgs);
 
 	ASSERT(MBC_BLK_SZ(blk) >= allctr->min_block_size);
@@ -2810,7 +3038,7 @@ mbc_realloc(Allctr_t *allctr, void *p, Uint size, Uint32 alcu_flgs,
 	    }
 
 	    ERTS_ALC_CPOOL_REALLOC_OP(allctr);
-	    STAT_MBC_BLK_FREE(allctr, crr, NULL, old_blk_sz, alcu_flgs);
+	    STAT_MBC_BLK_FREE(allctr, type, crr, NULL, old_blk_sz, alcu_flgs);
 	    STAT_MBC_BLK_ALLOC(allctr, crr, blk_sz, alcu_flgs);
 
 	    ASSERT(IS_ALLOCED_BLK(blk));
@@ -2871,7 +3099,7 @@ mbc_realloc(Allctr_t *allctr, void *p, Uint size, Uint32 alcu_flgs,
 	if (!new_p)
 	    return NULL;
 	sys_memcpy(new_p, p, MIN(size, old_blk_sz - ABLK_HDR_SZ));
-	mbc_free(allctr, p, busy_pcrr_pp);
+	mbc_free(allctr, type, p, busy_pcrr_pp);
 
 	return new_p;
 
@@ -2901,7 +3129,7 @@ mbc_realloc(Allctr_t *allctr, void *p, Uint size, Uint32 alcu_flgs,
 			       1);
 	    new_p = BLK2UMEM(new_blk);
 	    sys_memcpy(new_p, p, MIN(size, old_blk_sz - ABLK_HDR_SZ));
-	    mbc_free(allctr, p, NULL);
+	    mbc_free(allctr, type, p, NULL);
 	    return new_p;
 	}
 	else {
@@ -2958,7 +3186,7 @@ mbc_realloc(Allctr_t *allctr, void *p, Uint size, Uint32 alcu_flgs,
 			       0);
 
 	    ERTS_ALC_CPOOL_FREE_OP(allctr);
-	    STAT_MBC_BLK_FREE(allctr, crr, NULL, old_blk_sz, alcu_flgs);
+	    STAT_MBC_BLK_FREE(allctr, type, crr, NULL, old_blk_sz, alcu_flgs);
 
 	    return new_p;
 	}
@@ -2969,7 +3197,6 @@ mbc_realloc(Allctr_t *allctr, void *p, Uint size, Uint32 alcu_flgs,
 
 #define ERTS_ALC_MAX_DEALLOC_CARRIER		10
 #define ERTS_ALC_CPOOL_MAX_FETCH_INSPECT	100
-#define ERTS_ALC_CPOOL_CHECK_LIMIT_COUNT	100
 #define ERTS_ALC_CPOOL_MAX_FAILED_STAT_READS	3
 
 #define ERTS_ALC_CPOOL_PTR_MOD_MRK		(((erts_aint_t) 1) << 0)
@@ -2996,14 +3223,11 @@ typedef union {
 #  error "Carrier pool implementation assumes ERTS_ALC_A_MIN > ERTS_ALC_A_INVALID"
 #endif
 
-/*
- * The pool is only allowed to be manipulated by managed
- * threads except in the alloc_SUITE:cpool case. In this
- * test case carrier_pool[ERTS_ALC_A_INVALID] will be
- * used.
- */
+/* The pools are only allowed to be manipulated by managed threads except in
+ * the alloc_SUITE:cpool test, where only test_carrier_pool is used. */
 
-static ErtsAlcCrrPool_t carrier_pool[ERTS_ALC_A_MAX+1] erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+static ErtsAlcCrrPool_t firstfit_carrier_pool;
+static ErtsAlcCrrPool_t test_carrier_pool;
 
 #define ERTS_ALC_CPOOL_MAX_BACKOFF (1 << 8)
 
@@ -3024,12 +3248,12 @@ backoff(int n)
 static int
 cpool_dbg_is_in_pool(Allctr_t *allctr, Carrier_t *crr)
 {
-    ErtsAlcCPoolData_t *sentinel = &carrier_pool[allctr->alloc_no].sentinel;
+    ErtsAlcCPoolData_t *sentinel = allctr->cpool.sentinel;
     ErtsAlcCPoolData_t *cpdp = sentinel;
     Carrier_t *tmp_crr;
 
     while (1) {
-	cpdp = (ErtsAlcCPoolData_t *) (erts_atomic_read_ddrb(&cpdp->next) & ~FLG_MASK);
+	cpdp = (ErtsAlcCPoolData_t *) (erts_atomic_read_ddrb(&cpdp->next) & ~CRR_FLG_MASK);
 	if (cpdp == sentinel)
 	    return 0;
 	tmp_crr = (Carrier_t *) (((char *) cpdp) - offsetof(Carrier_t, cpool));
@@ -3041,7 +3265,7 @@ cpool_dbg_is_in_pool(Allctr_t *allctr, Carrier_t *crr)
 static int
 cpool_is_empty(Allctr_t *allctr)
 {
-    ErtsAlcCPoolData_t *sentinel = &carrier_pool[allctr->alloc_no].sentinel;
+    ErtsAlcCPoolData_t *sentinel = allctr->cpool.sentinel;
     return ((erts_atomic_read_rb(&sentinel->next) == (erts_aint_t) sentinel)
 	    && (erts_atomic_read_rb(&sentinel->prev) == (erts_aint_t) sentinel));
 }
@@ -3131,16 +3355,31 @@ cpool_insert(Allctr_t *allctr, Carrier_t *crr)
 {
     ErtsAlcCPoolData_t *cpd1p, *cpd2p;
     erts_aint_t val;
-    ErtsAlcCPoolData_t *sentinel = &carrier_pool[allctr->alloc_no].sentinel;
+    ErtsAlcCPoolData_t *sentinel = allctr->cpool.sentinel;
     Allctr_t *orig_allctr = crr->cpool.orig_allctr;
 
-    ERTS_ALC_CPOOL_ASSERT(allctr->alloc_no == ERTS_ALC_A_INVALID /* testcase */
+    ERTS_ALC_CPOOL_ASSERT(allctr->alloc_no == ERTS_ALC_A_TEST /* testcase */
 			  || erts_thr_progress_is_managed_thread());
 
-    erts_atomic_add_nob(&orig_allctr->cpool.stat.blocks_size,
-			(erts_aint_t) crr->cpool.blocks_size);
-    erts_atomic_add_nob(&orig_allctr->cpool.stat.no_blocks,
-			(erts_aint_t) crr->cpool.blocks);
+    {
+        int alloc_no = allctr->alloc_no;
+
+        ERTS_ALC_CPOOL_ASSERT(
+            erts_atomic_read_nob(&orig_allctr->cpool.stat.blocks_size[alloc_no]) >= 0 &&
+            crr->cpool.blocks_size[alloc_no] >= 0);
+
+        ERTS_ALC_CPOOL_ASSERT(
+            erts_atomic_read_nob(&orig_allctr->cpool.stat.no_blocks[alloc_no]) >= 0 &&
+            crr->cpool.blocks[alloc_no] >= 0);
+
+        /* We only modify the counter for our current type since the others are
+         * conceptually still in the pool. */
+        erts_atomic_add_nob(&orig_allctr->cpool.stat.blocks_size[alloc_no],
+                            ((erts_aint_t) crr->cpool.blocks_size[alloc_no]));
+        erts_atomic_add_nob(&orig_allctr->cpool.stat.no_blocks[alloc_no],
+                            ((erts_aint_t) crr->cpool.blocks[alloc_no]));
+    }
+
     erts_atomic_add_nob(&orig_allctr->cpool.stat.carriers_size,
 			(erts_aint_t) CARRIER_SZ(crr));
     erts_atomic_inc_nob(&orig_allctr->cpool.stat.no_carriers);
@@ -3213,10 +3452,10 @@ cpool_delete(Allctr_t *allctr, Allctr_t *prev_allctr, Carrier_t *crr)
     ErtsAlcCPoolData_t *cpd1p, *cpd2p;
     erts_aint_t val;
 #ifdef ERTS_ALC_CPOOL_DEBUG
-    ErtsAlcCPoolData_t *sentinel = &carrier_pool[allctr->alloc_no].sentinel;
+    ErtsAlcCPoolData_t *sentinel = allctr->cpool.sentinel;
 #endif
 
-    ERTS_ALC_CPOOL_ASSERT(allctr->alloc_no == ERTS_ALC_A_INVALID /* testcase */
+    ERTS_ALC_CPOOL_ASSERT(allctr->alloc_no == ERTS_ALC_A_TEST /* testcase */
 			  || erts_thr_progress_is_managed_thread());
     ERTS_ALC_CPOOL_ASSERT(sentinel != &crr->cpool);
 
@@ -3292,28 +3531,43 @@ cpool_delete(Allctr_t *allctr, Allctr_t *prev_allctr, Carrier_t *crr)
 
     crr->cpool.thr_prgr = erts_thr_progress_later(NULL);
 
-    erts_atomic_add_nob(&prev_allctr->cpool.stat.blocks_size,
-			-((erts_aint_t) crr->cpool.blocks_size));
-    erts_atomic_add_nob(&prev_allctr->cpool.stat.no_blocks,
-			-((erts_aint_t) crr->cpool.blocks));
-    erts_atomic_add_nob(&prev_allctr->cpool.stat.carriers_size,
+    {
+        Allctr_t *orig_allctr = crr->cpool.orig_allctr;
+        int alloc_no = allctr->alloc_no;
+
+        ERTS_ALC_CPOOL_ASSERT(orig_allctr == prev_allctr);
+
+        ERTS_ALC_CPOOL_ASSERT(crr->cpool.blocks_size[alloc_no] <=
+            erts_atomic_read_nob(&orig_allctr->cpool.stat.blocks_size[alloc_no]));
+
+        ERTS_ALC_CPOOL_ASSERT(crr->cpool.blocks[alloc_no] <=
+            erts_atomic_read_nob(&orig_allctr->cpool.stat.no_blocks[alloc_no]));
+
+        /* We only modify the counters for our current type since the others
+         * were, conceptually, never taken out of the pool. */
+        erts_atomic_add_nob(&orig_allctr->cpool.stat.blocks_size[alloc_no],
+                            -((erts_aint_t) crr->cpool.blocks_size[alloc_no]));
+        erts_atomic_add_nob(&orig_allctr->cpool.stat.no_blocks[alloc_no],
+                            -((erts_aint_t) crr->cpool.blocks[alloc_no]));
+
+        erts_atomic_add_nob(&orig_allctr->cpool.stat.carriers_size,
 			-((erts_aint_t) CARRIER_SZ(crr)));
-    erts_atomic_dec_wb(&prev_allctr->cpool.stat.no_carriers);
+        erts_atomic_dec_wb(&orig_allctr->cpool.stat.no_carriers);
+    }
 
 }
 
 static Carrier_t *
 cpool_fetch(Allctr_t *allctr, UWord size)
 {
-    enum { IGNORANT, HAS_SEEN_SENTINEL, THE_LAST_ONE } loop_state;
-    int i;
+    int i, seen_sentinel;
     Carrier_t *crr;
     Carrier_t *reinsert_crr = NULL;
     ErtsAlcCPoolData_t *cpdp;
     ErtsAlcCPoolData_t *cpool_entrance = NULL;
     ErtsAlcCPoolData_t *sentinel;
 
-    ERTS_ALC_CPOOL_ASSERT(allctr->alloc_no == ERTS_ALC_A_INVALID /* testcase */
+    ERTS_ALC_CPOOL_ASSERT(allctr->alloc_no == ERTS_ALC_A_TEST /* testcase */
 			  || erts_thr_progress_is_managed_thread());
 
     i = ERTS_ALC_CPOOL_MAX_FETCH_INSPECT;
@@ -3415,48 +3669,39 @@ cpool_fetch(Allctr_t *allctr, UWord size)
     /*
      * Finally search the shared pool and try employ foreign carriers
      */
-    sentinel = &carrier_pool[allctr->alloc_no].sentinel;
+    sentinel = allctr->cpool.sentinel;
     if (cpool_entrance) {
         /*
          * We saw a pooled carried above, use it as entrance into the pool
 	 */
-	cpdp = cpool_entrance;
     }
     else {
         /*
-         * No pooled carried seen above. Start search at cpool sentinel,
+         * No pooled carrier seen above. Start search at cpool sentinel,
 	 * but begin by passing one element before trying to fetch.
 	 * This in order to avoid contention with threads inserting elements.
 	 */
-	cpool_entrance = sentinel;
-	cpdp = cpool_aint2cpd(cpool_read(&cpool_entrance->prev));
-	if (cpdp == sentinel)
+        cpool_entrance = cpool_aint2cpd(cpool_read(&sentinel->prev));
+	if (cpool_entrance == sentinel)
 	    goto check_dc_list;
     }
 
-    loop_state = IGNORANT;
+    cpdp = cpool_entrance;
+    seen_sentinel = 0;
     do {
 	erts_aint_t exp;
 	cpdp = cpool_aint2cpd(cpool_read(&cpdp->prev));
-	if (cpdp == cpool_entrance) {
-	    if (cpool_entrance == sentinel) {
-		cpdp = cpool_aint2cpd(cpool_read(&cpdp->prev));
-		if (cpdp == sentinel)
-		    break;
-	    }
-            loop_state = THE_LAST_ONE;
-	}
-	else if (cpdp == sentinel) {
-	    if (loop_state == HAS_SEEN_SENTINEL) {
+        if (cpdp == sentinel) {
+	    if (seen_sentinel) {
 		/* We been here before. cpool_entrance must have been removed */
                 INC_CC(allctr->cpool.stat.entrance_removed);
 		break;
 	    }
-	    cpdp = cpool_aint2cpd(cpool_read(&cpdp->prev));
-	    if (cpdp == sentinel)
-                break;
-            loop_state = HAS_SEEN_SENTINEL;
+            seen_sentinel = 1;
+            continue;
 	}
+        ASSERT(cpdp != cpool_entrance || seen_sentinel);
+
 	crr = ErtsContainerStruct(cpdp, Carrier_t, cpool);
 	exp = erts_atomic_read_rb(&crr->allctr);
 
@@ -3489,7 +3734,7 @@ cpool_fetch(Allctr_t *allctr, UWord size)
             INC_CC(allctr->cpool.stat.fail_shared);
 	    return NULL;
         }
-    }while (loop_state != THE_LAST_ONE);
+    }while (cpdp != cpool_entrance);
 
 check_dc_list:
     /* Last; check our own pending dealloc carrier list... */
@@ -3668,8 +3913,9 @@ cpool_init_carrier_data(Allctr_t *allctr, Carrier_t *crr)
     crr->cpool.orig_allctr = allctr;
     crr->cpool.thr_prgr = ERTS_THR_PRGR_INVALID;
     erts_atomic_init_nob(&crr->cpool.max_size, 0);
-    crr->cpool.blocks = 0;
-    crr->cpool.blocks_size = 0;
+    sys_memset(&crr->cpool.blocks_size, 0, sizeof(crr->cpool.blocks_size));
+    sys_memset(&crr->cpool.blocks, 0, sizeof(crr->cpool.blocks));
+    crr->cpool.total_blocks_size = 0;
     if (!ERTS_ALC_IS_CPOOL_ENABLED(allctr))
 	crr->cpool.abandon_limit = 0;
     else {
@@ -3684,14 +3930,14 @@ cpool_init_carrier_data(Allctr_t *allctr, Carrier_t *crr)
     crr->cpool.state = ERTS_MBC_IS_HOME;
 }
 
-static void
-set_new_allctr_abandon_limit(Allctr_t *allctr)
+
+
+static UWord
+allctr_abandon_limit(Allctr_t *allctr)
 {
     UWord limit;
     UWord csz;
 
-    allctr->cpool.check_limit_count = ERTS_ALC_CPOOL_CHECK_LIMIT_COUNT;
-
     csz = allctr->mbcs.curr.norm.mseg.size;
     csz += allctr->mbcs.curr.norm.sys_alloc.size;
 
@@ -3701,7 +3947,13 @@ set_new_allctr_abandon_limit(Allctr_t *allctr)
     else
 	limit = (csz/100)*allctr->cpool.util_limit;
 
-    allctr->cpool.abandon_limit = limit;
+    return limit;
+}
+
+static void ERTS_INLINE
+set_new_allctr_abandon_limit(Allctr_t *allctr)
+{
+    allctr->cpool.abandon_limit = allctr_abandon_limit(allctr);
 }
 
 static void
@@ -3713,7 +3965,9 @@ abandon_carrier(Allctr_t *allctr, Carrier_t *crr)
 
     unlink_carrier(&allctr->mbc_list, crr);
     allctr->remove_mbc(allctr, crr);
-    set_new_allctr_abandon_limit(allctr);
+
+    /* Mark our free blocks as unused and reclaimable to the OS. */
+    carrier_mem_discard_free_blocks(allctr, crr);
 
     cpool_insert(allctr, crr);
 
@@ -3766,7 +4020,8 @@ poolify_my_carrier(Allctr_t *allctr, Carrier_t *crr)
 }
 
 static void
-cpool_read_stat(Allctr_t *allctr, UWord *nocp, UWord *cszp, UWord *nobp, UWord *bszp)
+cpool_read_stat(Allctr_t *allctr, int alloc_no,
+                UWord *nocp, UWord *cszp, UWord *nobp, UWord *bszp)
 {
     int i;
     UWord noc = 0, csz = 0, nob = 0, bsz = 0;
@@ -3786,10 +4041,10 @@ cpool_read_stat(Allctr_t *allctr, UWord *nocp, UWord *cszp, UWord *nobp, UWord *
 			? erts_atomic_read_nob(&allctr->cpool.stat.carriers_size)
 			: 0);
 	tnob = (UWord) (nobp
-			? erts_atomic_read_nob(&allctr->cpool.stat.no_blocks)
+			? erts_atomic_read_nob(&allctr->cpool.stat.no_blocks[alloc_no])
 			: 0);
 	tbsz = (UWord) (bszp
-			? erts_atomic_read_nob(&allctr->cpool.stat.blocks_size)
+			? erts_atomic_read_nob(&allctr->cpool.stat.blocks_size[alloc_no])
 			: 0);
 	if (tnoc == noc && tcsz == csz && tnob == nob && tbsz == bsz)
 	    break;
@@ -4044,6 +4299,7 @@ create_carrier(Allctr_t *allctr, Uint umem_sz, UWord flags)
 #if HAVE_ERTS_MSEG
     mbc_final_touch:
 #endif
+        set_new_allctr_abandon_limit(allctr);
 
 	blk = MBC_TO_FIRST_BLK(allctr, crr);
 
@@ -4262,7 +4518,6 @@ destroy_carrier(Allctr_t *allctr, Block_t *blk, Carrier_t **busy_pcrr_pp)
     else {
 	ASSERT(IS_MBC_FIRST_FBLK(allctr, blk));
 	crr = FIRST_BLK_TO_MBC(allctr, blk);
-	crr_sz = CARRIER_SZ(crr);
 
 #ifdef DEBUG
 	if (!allctr->stopped) {
@@ -4294,15 +4549,7 @@ destroy_carrier(Allctr_t *allctr, Block_t *blk, Carrier_t **busy_pcrr_pp)
 	else
 	{
 	    unlink_carrier(&allctr->mbc_list, crr);
-#if HAVE_ERTS_MSEG
-	    if (IS_MSEG_CARRIER(crr)) {
-		ASSERT(crr_sz % ERTS_SACRR_UNIT_SZ == 0);
-		STAT_MSEG_MBC_FREE(allctr, crr_sz);
-	    }
-	    else
-#endif
-		STAT_SYS_ALLOC_MBC_FREE(allctr, crr_sz);
-
+            STAT_MBC_FREE(allctr, crr);
             if (allctr->remove_mbc)
                 allctr->remove_mbc(allctr, crr);
 	}
@@ -4316,7 +4563,7 @@ destroy_carrier(Allctr_t *allctr, Block_t *blk, Carrier_t **busy_pcrr_pp)
             LTTNG5(carrier_destroy,
                 ERTS_ALC_A2AD(allctr->alloc_no),
                 allctr->ix,
-                crr_sz,
+                CARRIER_SZ(crr),
                 mbc_stats,
                 sbc_stats);
         }
@@ -4394,6 +4641,8 @@ static struct {
     Eterm blocks_size;
     Eterm blocks;
 
+    Eterm foreign_blocks;
+
     Eterm calls;
     Eterm sys_alloc;
     Eterm sys_free;
@@ -4494,6 +4743,7 @@ init_atoms(Allctr_t *allctr)
 	AM_INIT(carriers);
 	AM_INIT(blocks_size);
 	AM_INIT(blocks);
+	AM_INIT(foreign_blocks);
 
 	AM_INIT(calls);
 	AM_INIT(sys_alloc);
@@ -4629,7 +4879,6 @@ sz_info_fix(Allctr_t *allctr,
 		ErtsAlcFixList_t *fix = &allctr->fix[ix];
 		UWord alloced = fix->type_size * fix->u.cpool.allocated;
 		UWord used = fix->type_size * fix->u.cpool.used;
-                ErtsAlcType_t n = ERTS_ALC_N_MIN_A_FIXED_SIZE + ix;
 
 		if (print_to_p) {
 		    fmtfn_t to = *print_to_p;
@@ -4637,14 +4886,14 @@ sz_info_fix(Allctr_t *allctr,
 		    erts_print(to,
 			       arg,
 			       "fix type internal: %s %bpu %bpu\n",
-			       (char *) ERTS_ALC_N2TD(n),
+			       (char *) ERTS_ALC_T2TD(fix->type),
 			       alloced,
 			       used);
 		}
 
 		if (hpp || szp) {
 		    add_3tup(hpp, szp, &res,
-			     alloc_type_atoms[n],
+			     alloc_type_atoms[ERTS_ALC_T2N(fix->type)],
 			     bld_unstable_uint(hpp, szp, alloced),
 			     bld_unstable_uint(hpp, szp, used));
 		}
@@ -4657,7 +4906,6 @@ sz_info_fix(Allctr_t *allctr,
 	    ErtsAlcFixList_t *fix = &allctr->fix[ix];
 	    UWord alloced = fix->type_size * fix->u.nocpool.allocated;
 	    UWord used = fix->type_size*fix->u.nocpool.used;
-            ErtsAlcType_t n = ERTS_ALC_N_MIN_A_FIXED_SIZE + ix;
 
 	    if (print_to_p) {
 		fmtfn_t to = *print_to_p;
@@ -4665,14 +4913,14 @@ sz_info_fix(Allctr_t *allctr,
 		erts_print(to,
 			   arg,
 			   "fix type: %s %bpu %bpu\n",
-			   (char *) ERTS_ALC_N2TD(n),
+			   (char *) ERTS_ALC_T2TD(fix->type),
 			   alloced,
 			   used);
 	    }
 
 	    if (hpp || szp) {
 		add_3tup(hpp, szp, &res,
-			 alloc_type_atoms[n],
+			 alloc_type_atoms[ERTS_ALC_T2N(fix->type)],
 			 bld_unstable_uint(hpp, szp, alloced),
 			 bld_unstable_uint(hpp, szp, used));
 	    }
@@ -4745,9 +4993,9 @@ info_cpool(Allctr_t *allctr,
     noc = csz = nob = bsz = ~0;
     if (print_to_p || hpp) {
 	if (sz_only)
-	    cpool_read_stat(allctr, NULL, &csz, NULL, &bsz);
+	    cpool_read_stat(allctr, allctr->alloc_no, NULL, &csz, NULL, &bsz);
 	else
-	    cpool_read_stat(allctr, &noc, &csz, &nob, &bsz);
+	    cpool_read_stat(allctr, allctr->alloc_no, &noc, &csz, &nob, &bsz);
     }
 
     if (print_to_p) {
@@ -4762,6 +5010,10 @@ info_cpool(Allctr_t *allctr,
     }
 
     if (hpp || szp) {
+        Eterm foreign_blocks;
+        int i;
+
+        foreign_blocks = NIL;
 	res = NIL;
 
       if (!sz_only) {
@@ -4808,22 +5060,61 @@ info_cpool(Allctr_t *allctr,
         add_3tup(hpp, szp, &res, am.entrance_removed,
                  bld_unstable_uint(hpp, szp, ERTS_ALC_CC_GIGA_VAL(allctr->cpool.stat.entrance_removed)),
                  bld_unstable_uint(hpp, szp, ERTS_ALC_CC_VAL(allctr->cpool.stat.entrance_removed)));
+       }
 
 	add_2tup(hpp, szp, &res,
 		 am.carriers_size,
 		 bld_unstable_uint(hpp, szp, csz));
-      }
-	if (!sz_only)
-	    add_2tup(hpp, szp, &res,
-		     am.carriers,
-		     bld_unstable_uint(hpp, szp, noc));
+
+        if (!sz_only) {
+            add_2tup(hpp, szp, &res,
+                     am.carriers,
+                     bld_unstable_uint(hpp, szp, noc));
+        }
+
 	add_2tup(hpp, szp, &res,
 		 am.blocks_size,
 		 bld_unstable_uint(hpp, szp, bsz));
-	if (!sz_only)
+
+	if (!sz_only) {
 	    add_2tup(hpp, szp, &res,
 		     am.blocks,
 		     bld_unstable_uint(hpp, szp, nob));
+        }
+
+        for (i = ERTS_ALC_A_MIN; i <= ERTS_ALC_A_MAX; i++) {
+            const char *name_str;
+            Eterm name, info;
+
+            if (i == allctr->alloc_no) {
+                continue;
+            }
+
+            cpool_read_stat(allctr, i, NULL, NULL, &nob, &bsz);
+
+            if (bsz == 0 && (nob == 0 || sz_only)) {
+                continue;
+            }
+
+            name_str = ERTS_ALC_A2AD(i);
+            info = NIL;
+
+            add_2tup(hpp, szp, &info,
+                     am.blocks_size,
+                     bld_unstable_uint(hpp, szp, bsz));
+
+            if (!sz_only) {
+                add_2tup(hpp, szp, &info,
+                     am.blocks,
+                     bld_unstable_uint(hpp, szp, nob));
+            }
+
+            name = am_atom_put(name_str, sys_strlen(name_str));
+
+            add_2tup(hpp, szp, &foreign_blocks, name, info);
+        }
+
+        add_2tup(hpp, szp, &res, am.foreign_blocks, foreign_blocks);
     }
 
     return res;
@@ -5459,6 +5750,19 @@ erts_alcu_info(Allctr_t *allctr,
     return res;
 }
 
+void
+erts_alcu_foreign_size(Allctr_t *allctr, ErtsAlcType_t alloc_no, AllctrSize_t *size)
+{
+    if (ERTS_ALC_IS_CPOOL_ENABLED(allctr)) {
+        UWord csz, bsz;
+        cpool_read_stat(allctr, alloc_no, NULL, &csz, NULL, &bsz);
+        size->carriers = csz;
+        size->blocks = bsz;
+    } else {
+        size->carriers = 0;
+        size->blocks = 0;
+    }
+}
 
 void
 erts_alcu_current_size(Allctr_t *allctr, AllctrSize_t *size, ErtsAlcUFixInfo_t *fi, int fisz)
@@ -5477,7 +5781,7 @@ erts_alcu_current_size(Allctr_t *allctr, AllctrSize_t *size, ErtsAlcUFixInfo_t *
 
     if (ERTS_ALC_IS_CPOOL_ENABLED(allctr)) {
 	UWord csz, bsz;
-	cpool_read_stat(allctr, NULL, &csz, NULL, &bsz);
+	cpool_read_stat(allctr, allctr->alloc_no, NULL, &csz, NULL, &bsz);
 	size->blocks += bsz;
 	size->carriers += csz;
     }
@@ -5522,6 +5826,11 @@ do_erts_alcu_alloc(ErtsAlcType_t type, Allctr_t *allctr, Uint size)
 
     ERTS_ALCU_DBG_CHK_THR_ACCESS(allctr);
 
+    /* Reject sizes that can't fit into the header word. */
+    if (size > ~BLK_FLG_MASK) {
+        return NULL;
+    }
+
 #if ALLOC_ZERO_EQ_NULL
     if (!size)
 	return NULL;
@@ -5688,12 +5997,11 @@ do_erts_alcu_free(ErtsAlcType_t type, Allctr_t *allctr, void *p,
     ERTS_ALCU_DBG_CHK_THR_ACCESS(allctr);
 
     if (p) {
-
 	INC_CC(allctr->calls.this_free);
 
-	if (allctr->fix) {
+        if (ERTS_ALC_IS_FIX_TYPE(type)) {
 	    if (ERTS_ALC_IS_CPOOL_ENABLED(allctr))
-		fix_cpool_free(allctr, type, p, busy_pcrr_pp, 1);
+		fix_cpool_free(allctr, type, 0, p, busy_pcrr_pp);
 	    else
 		fix_nocpool_free(allctr, type, p);
 	}
@@ -5702,7 +6010,7 @@ do_erts_alcu_free(ErtsAlcType_t type, Allctr_t *allctr, void *p,
 	    if (IS_SBC_BLK(blk))
 		destroy_carrier(allctr, blk, NULL);
 	    else
-		mbc_free(allctr, p, busy_pcrr_pp);
+		mbc_free(allctr, type, p, busy_pcrr_pp);
 	}
     }
 }
@@ -5804,6 +6112,11 @@ do_erts_alcu_realloc(ErtsAlcType_t type,
 	return res;
     }
 
+    /* Reject sizes that can't fit into the header word. */
+    if (size > ~BLK_FLG_MASK) {
+        return NULL;
+    }
+
 #if ALLOC_ZERO_EQ_NULL
     if (!size) {
 	ASSERT(p);
@@ -5820,7 +6133,7 @@ do_erts_alcu_realloc(ErtsAlcType_t type,
 
     if (size < allctr->sbc_threshold) {
 	if (IS_MBC_BLK(blk))
-	    res = mbc_realloc(allctr, p, size, alcu_flgs, busy_pcrr_pp);
+	    res = mbc_realloc(allctr, type, p, size, alcu_flgs, busy_pcrr_pp);
 	else {
 	    Uint used_sz = SBC_HEADER_SIZE + ABLK_HDR_SZ + size;
 	    Uint crr_sz;
@@ -5879,7 +6192,7 @@ do_erts_alcu_realloc(ErtsAlcType_t type,
 		sys_memcpy((void *) res,
 			   (void *) p,
 			   MIN(MBC_ABLK_SZ(blk) - ABLK_HDR_SZ, size));
-		mbc_free(allctr, p, busy_pcrr_pp);
+		mbc_free(allctr, type, p, busy_pcrr_pp);
 	    }
 	    else
 		res = NULL;
@@ -6247,12 +6560,21 @@ int
 erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init)
 {
     /* erts_alcu_start assumes that allctr has been zeroed */
+    int i;
 
     if (((UWord)allctr & ERTS_CRR_ALCTR_FLG_MASK) != 0) {
         erts_exit(ERTS_ABORT_EXIT, "%s:%d:erts_alcu_start: Alignment error\n",
                  __FILE__, __LINE__);
     }
 
+    /* The various fields packed into the header word must not overlap */
+    ERTS_CT_ASSERT(!(MBC_ABLK_OFFSET_MASK & MBC_ABLK_SZ_MASK));
+    ERTS_CT_ASSERT(!(MBC_ABLK_OFFSET_MASK & BLK_FLG_MASK));
+    ERTS_CT_ASSERT(!(MBC_ABLK_SZ_MASK & BLK_FLG_MASK));
+    ERTS_CT_ASSERT(!(MBC_FBLK_SZ_MASK & BLK_FLG_MASK));
+    ERTS_CT_ASSERT(!(SBC_BLK_SZ_MASK & BLK_FLG_MASK));
+    ERTS_CT_ASSERT(!(CRR_SZ_MASK & CRR_FLG_MASK));
+
     if (!initialized)
 	goto error;
 
@@ -6270,6 +6592,11 @@ erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init)
 
     allctr->ix				= init->ix;
     allctr->alloc_no			= init->alloc_no;
+    allctr->alloc_strat			= init->alloc_strat;
+
+    ASSERT(allctr->alloc_no >= ERTS_ALC_A_MIN &&
+           allctr->alloc_no <= ERTS_ALC_A_MAX);
+
     if (allctr->alloc_no < ERTS_ALC_A_MIN
 	|| ERTS_ALC_A_MAX < allctr->alloc_no)
 	allctr->alloc_no = ERTS_ALC_A_INVALID;
@@ -6322,8 +6649,7 @@ erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init)
 						       + sizeof(FreeBlkFtr_t));
     if (init->tpref) {
 	Uint sz = ABLK_HDR_SZ;
-	sz += (init->fix ? 
-	       sizeof(ErtsAllctrFixDDBlock_t) : sizeof(ErtsAllctrDDBlock_t));
+	sz += sizeof(ErtsAllctrDDBlock_t);
 	sz = UNIT_CEILING(sz);
 	if (sz > allctr->min_block_size)
 	    allctr->min_block_size = sz;
@@ -6334,15 +6660,29 @@ erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init)
     allctr->cpool.dc_list.last = NULL;
     allctr->cpool.abandon_limit = 0;
     allctr->cpool.disable_abandon = 0;
-    erts_atomic_init_nob(&allctr->cpool.stat.blocks_size, 0);
-    erts_atomic_init_nob(&allctr->cpool.stat.no_blocks, 0);
+    for (i = ERTS_ALC_A_MIN; i <= ERTS_ALC_A_MAX; i++) {
+        erts_atomic_init_nob(&allctr->cpool.stat.blocks_size[i], 0);
+        erts_atomic_init_nob(&allctr->cpool.stat.no_blocks[i], 0);
+    }
     erts_atomic_init_nob(&allctr->cpool.stat.carriers_size, 0);
     erts_atomic_init_nob(&allctr->cpool.stat.no_carriers, 0);
-    allctr->cpool.check_limit_count = ERTS_ALC_CPOOL_CHECK_LIMIT_COUNT;
     if (!init->ts && init->acul && init->acnl) {
+        ASSERT(allctr->add_mbc);
+        ASSERT(allctr->remove_mbc);
+        ASSERT(allctr->largest_fblk_in_mbc);
+        ASSERT(allctr->first_fblk_in_mbc);
+        ASSERT(allctr->next_fblk_in_mbc);
+
         allctr->cpool.util_limit = init->acul;
         allctr->cpool.in_pool_limit = init->acnl;
         allctr->cpool.fblk_min_limit = init->acfml;
+
+        if (allctr->alloc_strat == ERTS_ALC_S_FIRSTFIT) {
+            allctr->cpool.sentinel = &firstfit_carrier_pool.sentinel;
+        }
+        else if (allctr->alloc_no != ERTS_ALC_A_TEST) {
+            ERTS_INTERNAL_ERROR("Impossible carrier migration config.");
+        }
     }
     else {
         allctr->cpool.util_limit = 0;
@@ -6350,6 +6690,12 @@ erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init)
         allctr->cpool.fblk_min_limit = 0;
     }
 
+    /* The invasive tests don't really care whether the pool is enabled or not,
+     * so we need to set this unconditionally for this allocator type. */
+    if (allctr->alloc_no == ERTS_ALC_A_TEST) {
+        allctr->cpool.sentinel = &test_carrier_pool.sentinel;
+    }
+
     allctr->sbc_threshold = adjust_sbct(allctr, init->sbct);
 
 #if HAVE_ERTS_MSEG
@@ -6461,9 +6807,9 @@ erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init)
 	allctr->fix_shrink_scheduled = 0;
 	for (i = 0; i < ERTS_ALC_NO_FIXED_SIZES; i++) {
 	    allctr->fix[i].type_size = init->fix_type_size[i];
+	    allctr->fix[i].type = ERTS_ALC_N2T(i + ERTS_ALC_N_MIN_A_FIXED_SIZE);
 	    allctr->fix[i].list_size = 0;
 	    allctr->fix[i].list = NULL;
-	    ASSERT(allctr->fix[i].type_size >= sizeof(ErtsAllctrFixDDBlock_t));
 	    if (ERTS_ALC_IS_CPOOL_ENABLED(allctr)) {
 		allctr->fix[i].u.cpool.min_list_size = 0;
 		allctr->fix[i].u.cpool.shrink_list = 0;
@@ -6512,12 +6858,16 @@ erts_alcu_stop(Allctr_t *allctr)
 void
 erts_alcu_init(AlcUInit_t *init)
 {
-    int i;
-    for (i = 0; i <= ERTS_ALC_A_MAX; i++) {
-	ErtsAlcCPoolData_t *sentinel = &carrier_pool[i].sentinel;
-	erts_atomic_init_nob(&sentinel->next, (erts_aint_t) sentinel);
-	erts_atomic_init_nob(&sentinel->prev, (erts_aint_t) sentinel);
-    }
+    ErtsAlcCPoolData_t *sentinel;
+
+    sentinel = &firstfit_carrier_pool.sentinel;
+    erts_atomic_init_nob(&sentinel->next, (erts_aint_t) sentinel);
+    erts_atomic_init_nob(&sentinel->prev, (erts_aint_t) sentinel);
+
+    sentinel = &test_carrier_pool.sentinel;
+    erts_atomic_init_nob(&sentinel->next, (erts_aint_t) sentinel);
+    erts_atomic_init_nob(&sentinel->prev, (erts_aint_t) sentinel);
+
     ERTS_CT_ASSERT(SBC_BLK_SZ_MASK == MBC_FBLK_SZ_MASK); /* see BLK_SZ */
 #if HAVE_ERTS_MSEG
     ASSERT(erts_mseg_unit_size() == ERTS_SACRR_UNIT_SZ);
@@ -6528,6 +6878,8 @@ erts_alcu_init(AlcUInit_t *init)
 #endif
     allow_sys_alloc_carriers = init->sac;
 
+    sys_page_size = erts_sys_get_page_size();
+
 #ifdef DEBUG
     carrier_alignment = sizeof(Unit_t);
 #endif
@@ -6699,7 +7051,7 @@ static int blockscan_cpool_yielding(blockscan_t *state)
 {
     ErtsAlcCPoolData_t *sentinel, *cursor;
 
-    sentinel = &carrier_pool[(state->allocator)->alloc_no].sentinel;
+    sentinel = (state->allocator)->cpool.sentinel;
     cursor = blockscan_restore_cpool_cursor(state);
 
     if (ERTS_PROC_IS_EXITING(state->process)) {
@@ -6760,12 +7112,21 @@ static int blockscan_cpool_yielding(blockscan_t *state)
     return 0;
 }
 
-static int blockscan_yield_helper(blockscan_t *state,
-                                  int (*yielding_op)(blockscan_t*))
+/* */
+
+static int blockscan_finish(blockscan_t *state)
 {
-    /* Note that we don't check whether to abort here; only yielding_op knows
-     * whether the carrier is still in the list/pool. */
+    if (ERTS_PROC_IS_EXITING(state->process)) {
+        state->abort(state->user_data);
+        return 0;
+    }
+
+    state->current_op = blockscan_finish;
 
+    return state->finish(state->user_data);
+}
+
+static void blockscan_lock_helper(blockscan_t *state) {
     if ((state->allocator)->thread_safe) {
         /* Locked scans have to be as short as possible. */
         state->reductions = 1;
@@ -6774,34 +7135,18 @@ static int blockscan_yield_helper(blockscan_t *state,
     } else {
         state->reductions = BLOCKSCAN_REDUCTIONS;
     }
+}
 
-    if (yielding_op(state)) {
-        state->next_op = state->current_op;
-    }
-
+static void blockscan_unlock_helper(blockscan_t *state) {
     if ((state->allocator)->thread_safe) {
         erts_mtx_unlock(&(state->allocator)->mutex);
     }
-
-    return 1;
-}
-
-/* */
-
-static int blockscan_finish(blockscan_t *state)
-{
-    if (ERTS_PROC_IS_EXITING(state->process)) {
-        state->abort(state->user_data);
-        return 0;
-    }
-
-    state->current_op = blockscan_finish;
-
-    return state->finish(state->user_data);
 }
 
 static int blockscan_sweep_sbcs(blockscan_t *state)
 {
+    blockscan_lock_helper(state);
+
     if (state->current_op != blockscan_sweep_sbcs) {
         SET_CARRIER_HDR(&state->dummy_carrier, 0, SCH_SBC, state->allocator);
         state->current_clist = &(state->allocator)->sbc_list;
@@ -6811,11 +7156,19 @@ static int blockscan_sweep_sbcs(blockscan_t *state)
     state->current_op = blockscan_sweep_sbcs;
     state->next_op = blockscan_finish;
 
-    return blockscan_yield_helper(state, blockscan_clist_yielding);
+    if (blockscan_clist_yielding(state)) {
+        state->next_op = state->current_op;
+    }
+    
+    blockscan_unlock_helper(state);
+
+    return 1;
 }
 
 static int blockscan_sweep_mbcs(blockscan_t *state)
 {
+    blockscan_lock_helper(state);
+
     if (state->current_op != blockscan_sweep_mbcs) {
         SET_CARRIER_HDR(&state->dummy_carrier, 0, SCH_MBC, state->allocator);
         state->current_clist = &(state->allocator)->mbc_list;
@@ -6825,23 +7178,34 @@ static int blockscan_sweep_mbcs(blockscan_t *state)
     state->current_op = blockscan_sweep_mbcs;
     state->next_op = blockscan_sweep_sbcs;
 
-    return blockscan_yield_helper(state, blockscan_clist_yielding);
+    if (blockscan_clist_yielding(state)) {
+        state->next_op = state->current_op;
+    }
+
+    blockscan_unlock_helper(state);
+
+    return 1;
 }
 
 static int blockscan_sweep_cpool(blockscan_t *state)
 {
-    if (state->current_op != blockscan_sweep_cpool) {
-        ErtsAlcCPoolData_t *sentinel;
+    blockscan_lock_helper(state);
 
+    if (state->current_op != blockscan_sweep_cpool) {
         SET_CARRIER_HDR(&state->dummy_carrier, 0, SCH_MBC, state->allocator);
-        sentinel = &carrier_pool[(state->allocator)->alloc_no].sentinel;
-        state->cpool_cursor = sentinel;
+        state->cpool_cursor = (state->allocator)->cpool.sentinel;
     }
 
     state->current_op = blockscan_sweep_cpool;
     state->next_op = blockscan_sweep_mbcs;
 
-    return blockscan_yield_helper(state, blockscan_cpool_yielding);
+    if (blockscan_cpool_yielding(state)) {
+        state->next_op = state->current_op;
+    }
+
+    blockscan_unlock_helper(state);
+
+    return 1;
 }
 
 static int blockscan_get_specific_allocator(int allocator_num,
@@ -7119,11 +7483,14 @@ static int gather_ahist_scan(Allctr_t *allocator,
         alcu_atag_t tag;
 
         block = SBC2BLK(allocator, carrier);
-        tag = GET_BLK_ATAG(block);
 
-        ASSERT(DBG_IS_VALID_ATAG(allocator, tag));
+        if (BLK_HAS_ATAG(block)) {
+            tag = GET_BLK_ATAG(block);
 
-        gather_ahist_update(state, tag, SBC_BLK_SZ(block));
+            ASSERT(DBG_IS_VALID_ATAG(tag));
+
+            gather_ahist_update(state, tag, SBC_BLK_SZ(block));
+        }
     } else {
         UWord scanned_bytes = MBC_HEADER_SIZE(allocator);
 
@@ -7134,10 +7501,10 @@ static int gather_ahist_scan(Allctr_t *allocator,
         while (1) {
             UWord block_size = MBC_BLK_SZ(block);
 
-            if (IS_ALLOCED_BLK(block)) {
+            if (IS_ALLOCED_BLK(block) && BLK_HAS_ATAG(block)) {
                 alcu_atag_t tag = GET_BLK_ATAG(block);
 
-                ASSERT(DBG_IS_VALID_ATAG(allocator, tag));
+                ASSERT(DBG_IS_VALID_ATAG(tag));
 
                 gather_ahist_update(state, tag, block_size);
             }
@@ -7159,7 +7526,7 @@ static int gather_ahist_scan(Allctr_t *allocator,
     return blocks_scanned;
 }
 
-static void gather_ahist_append_result(hist_tree_t *node, void *arg)
+static int gather_ahist_append_result(hist_tree_t *node, void *arg, Sint reds)
 {
     gather_ahist_t *state = (gather_ahist_t*)arg;
 
@@ -7193,6 +7560,7 @@ static void gather_ahist_append_result(hist_tree_t *node, void *arg)
 
     /* Plain free is intentional. */
     free(node);
+    return 1;
 }
 
 static void gather_ahist_send(gather_ahist_t *state)
@@ -7251,11 +7619,11 @@ static int gather_ahist_finish(void *arg)
         state->building_result = 1;
     }
 
-    if (hist_tree_rbt_foreach_destroy_yielding(&state->hist_tree,
-                                               &gather_ahist_append_result,
-                                               state,
-                                               &state->hist_tree_yield,
-                                               BLOCKSCAN_REDUCTIONS)) {
+    if (!hist_tree_rbt_foreach_destroy_yielding(&state->hist_tree,
+                                                &gather_ahist_append_result,
+                                                state,
+                                                &state->hist_tree_yield,
+                                                BLOCKSCAN_REDUCTIONS)) {
         return 1;
     }
 
@@ -7264,10 +7632,11 @@ static int gather_ahist_finish(void *arg)
     return 0;
 }
 
-static void gather_ahist_destroy_result(hist_tree_t *node, void *arg)
+static int gather_ahist_destroy_result(hist_tree_t *node, void *arg, Sint reds)
 {
     (void)arg;
     free(node);
+    return 1;
 }
 
 static void gather_ahist_abort(void *arg)
@@ -7297,8 +7666,6 @@ int erts_alcu_gather_alloc_histograms(Process *p, int allocator_num,
                                           sched_id,
                                           &allocator)) {
         return 0;
-    } else if (!allocator->atags) {
-        return 0;
     }
 
     ensure_atoms_initialized(allocator);
diff --git a/erts/emulator/beam/erl_alloc_util.h b/erts/emulator/beam/erl_alloc_util.h
index f26ace1534..b46b311c59 100644
--- a/erts/emulator/beam/erl_alloc_util.h
+++ b/erts/emulator/beam/erl_alloc_util.h
@@ -24,6 +24,7 @@
 #define ERTS_ALCU_VSN_STR "3.0"
 
 #include "erl_alloc_types.h"
+#include "erl_alloc.h"
 #define ERL_THREADS_EMU_INTERNAL__
 #include "erl_threads.h"
 
@@ -44,6 +45,7 @@ typedef struct {
 typedef struct {
     char *name_prefix;
     ErtsAlcType_t alloc_no;
+    ErtsAlcStrat_t alloc_strat;
     int force;
     int ix;
     int ts;
@@ -101,6 +103,7 @@ typedef struct {
 #define ERTS_DEFAULT_ALLCTR_INIT {                                         \
     NULL,                                                                  \
     ERTS_ALC_A_INVALID,	/* (number) alloc_no: allocator number           */\
+    ERTS_ALC_S_INVALID,	/* (number) alloc_strat: allocator strategy      */\
     0,			/* (bool)   force:  force enabled                */\
     0,			/* (number) ix: instance index                   */\
     1,			/* (bool)   ts:     thread safe                  */\
@@ -138,6 +141,7 @@ typedef struct {
 #define ERTS_DEFAULT_ALLCTR_INIT {                                         \
     NULL,                                                                  \
     ERTS_ALC_A_INVALID,	/* (number) alloc_no: allocator number           */\
+    ERTS_ALC_S_INVALID,	/* (number) alloc_strat: allocator strategy      */\
     0,			/* (bool)   force:  force enabled                */\
     0,			/* (number) ix: instance index                   */\
     1,			/* (bool)   ts:     thread safe                  */\
@@ -188,6 +192,7 @@ Eterm	erts_alcu_info(Allctr_t *, int, int, fmtfn_t *, void *, Uint **, Uint *);
 void	erts_alcu_init(AlcUInit_t *);
 void    erts_alcu_current_size(Allctr_t *, AllctrSize_t *,
 			       ErtsAlcUFixInfo_t *, int);
+void    erts_alcu_foreign_size(Allctr_t *, ErtsAlcType_t, AllctrSize_t *);
 void    erts_alcu_check_delayed_dealloc(Allctr_t *, int, int *, ErtsThrPrgrVal *, int *);
 erts_aint32_t erts_alcu_fix_alloc_shrink(Allctr_t *, erts_aint32_t);
 
@@ -286,10 +291,18 @@ void erts_alcu_sched_spec_data_init(struct ErtsSchedulerData_ *esdp);
 #define UNIT_FLOOR(X)	((X) & UNIT_MASK)
 #define UNIT_CEILING(X)	UNIT_FLOOR((X) + INV_UNIT_MASK)
 
-#define FLG_MASK		INV_UNIT_MASK
-#define SBC_BLK_SZ_MASK         UNIT_MASK
-#define MBC_FBLK_SZ_MASK        UNIT_MASK
-#define CARRIER_SZ_MASK         UNIT_MASK
+/* We store flags in the bits that no one will ever use. Generally these are
+ * the bits below the alignment size, but for blocks we also steal the highest
+ * bit since the header's a size and no one can expect to be able to allocate
+ * objects that large. */
+#define HIGHEST_WORD_BIT        (((UWord) 1) << (sizeof(UWord) * CHAR_BIT - 1))
+
+#define BLK_FLG_MASK            (INV_UNIT_MASK | HIGHEST_WORD_BIT)
+#define SBC_BLK_SZ_MASK         (~BLK_FLG_MASK)
+#define MBC_FBLK_SZ_MASK        (~BLK_FLG_MASK)
+
+#define CRR_FLG_MASK        INV_UNIT_MASK
+#define CRR_SZ_MASK         UNIT_MASK
 
 #if ERTS_HAVE_MSEG_SUPER_ALIGNED \
     || (!HAVE_ERTS_MSEG && ERTS_HAVE_ERTS_SYS_ALIGNED_ALLOC)
@@ -299,9 +312,9 @@ void erts_alcu_sched_spec_data_init(struct ErtsSchedulerData_ *esdp);
 #    define ERTS_SUPER_ALIGN_BITS 18
 #  endif
 #  ifdef ARCH_64 
-#    define MBC_ABLK_OFFSET_BITS   24
+#    define MBC_ABLK_OFFSET_BITS   23
 #  else
-#    define MBC_ABLK_OFFSET_BITS   9
+#    define MBC_ABLK_OFFSET_BITS   8
      /* Affects hard limits for sbct and lmbcs documented in erts_alloc.xml */
 #  endif
 #  define ERTS_SACRR_UNIT_SHIFT		ERTS_SUPER_ALIGN_BITS
@@ -321,19 +334,21 @@ void erts_alcu_sched_spec_data_init(struct ErtsSchedulerData_ *esdp);
 #endif
 
 #if MBC_ABLK_OFFSET_BITS
-#  define MBC_ABLK_OFFSET_SHIFT  (sizeof(UWord)*8 - MBC_ABLK_OFFSET_BITS)
-#  define MBC_ABLK_OFFSET_MASK   (~((UWord)0) << MBC_ABLK_OFFSET_SHIFT)
-#  define MBC_ABLK_SZ_MASK	(~MBC_ABLK_OFFSET_MASK & ~FLG_MASK)
+/* The shift is reduced by 1 since the highest bit is used for a flag. */
+#  define MBC_ABLK_OFFSET_SHIFT  (sizeof(UWord)*8 - 1 - MBC_ABLK_OFFSET_BITS)
+#  define MBC_ABLK_OFFSET_MASK \
+    (((UWORD_CONSTANT(1) << MBC_ABLK_OFFSET_BITS) - UWORD_CONSTANT(1)) \
+     << MBC_ABLK_OFFSET_SHIFT)
+#  define MBC_ABLK_SZ_MASK	(~MBC_ABLK_OFFSET_MASK & ~BLK_FLG_MASK)
 #else
-#  define MBC_ABLK_SZ_MASK	(~FLG_MASK)
+#  define MBC_ABLK_SZ_MASK	(~BLK_FLG_MASK)
 #endif
 
 #define MBC_ABLK_SZ(B) (ASSERT(!is_sbc_blk(B)), (B)->bhdr & MBC_ABLK_SZ_MASK)
 #define MBC_FBLK_SZ(B) (ASSERT(!is_sbc_blk(B)), (B)->bhdr & MBC_FBLK_SZ_MASK)
 #define SBC_BLK_SZ(B) (ASSERT(is_sbc_blk(B)), (B)->bhdr & SBC_BLK_SZ_MASK)
 
-#define CARRIER_SZ(C) \
-  ((C)->chdr & CARRIER_SZ_MASK)
+#define CARRIER_SZ(C) ((C)->chdr & CRR_SZ_MASK)
 
 typedef union {char c[ERTS_ALLOC_ALIGN_BYTES]; long l; double d;} Unit_t;
 
@@ -351,12 +366,20 @@ typedef struct {
 #endif
 } Block_t;
 
-typedef union ErtsAllctrDDBlock_t_ ErtsAllctrDDBlock_t;
+typedef struct ErtsAllctrDDBlock__ {
+    union  {
+        struct ErtsAllctrDDBlock__ *ptr_next;
+        erts_atomic_t atmc_next;
+    } u;
+    ErtsAlcType_t type;
+    Uint32 flags;
+} ErtsAllctrDDBlock_t;
 
-union ErtsAllctrDDBlock_t_ {
-    erts_atomic_t atmc_next;
-    ErtsAllctrDDBlock_t *ptr_next;
-};
+/* Deallocation was caused by shrinking a fix-list, so usage statistics has
+ * already been updated. */
+#define DEALLOC_FLG_FIX_SHRINK    (1 << 0)
+/* Deallocation was redirected to another instance. */
+#define DEALLOC_FLG_REDIRECTED    (1 << 1)
 
 typedef struct {
     Block_t blk;
@@ -365,11 +388,10 @@ typedef struct {
 #endif
 } ErtsFakeDDBlock_t;
 
-
-
 #define THIS_FREE_BLK_HDR_FLG 	(((UWord) 1) << 0)
 #define PREV_FREE_BLK_HDR_FLG 	(((UWord) 1) << 1)
 #define LAST_BLK_HDR_FLG 	(((UWord) 1) << 2)
+#define ATAG_BLK_HDR_FLG 	HIGHEST_WORD_BIT
 
 #define SBC_BLK_HDR_FLG /* Special flag combo for (allocated) SBC blocks */\
     (THIS_FREE_BLK_HDR_FLG | PREV_FREE_BLK_HDR_FLG | LAST_BLK_HDR_FLG)
@@ -381,9 +403,9 @@ typedef struct {
 #define HOMECOMING_MBC_BLK_HDR (THIS_FREE_BLK_HDR_FLG | LAST_BLK_HDR_FLG)
 
 #define IS_FREE_LAST_MBC_BLK(B) \
-    (((B)->bhdr & FLG_MASK) == (THIS_FREE_BLK_HDR_FLG | LAST_BLK_HDR_FLG))
+    (((B)->bhdr & BLK_FLG_MASK) == (THIS_FREE_BLK_HDR_FLG | LAST_BLK_HDR_FLG))
 
-#define IS_SBC_BLK(B) (((B)->bhdr & FLG_MASK) == SBC_BLK_HDR_FLG)
+#define IS_SBC_BLK(B) (((B)->bhdr & SBC_BLK_HDR_FLG) == SBC_BLK_HDR_FLG)
 #define IS_MBC_BLK(B) (!IS_SBC_BLK((B)))
 #define IS_FREE_BLK(B) (ASSERT(IS_MBC_BLK(B)), \
 			(B)->bhdr & THIS_FREE_BLK_HDR_FLG)
@@ -394,7 +416,8 @@ typedef struct {
 #  define ABLK_TO_MBC(B) \
     (ASSERT(IS_MBC_BLK(B) && !IS_FREE_BLK(B)), \
      (Carrier_t*)((ERTS_SACRR_UNIT_FLOOR((UWord)(B)) - \
-		  (((B)->bhdr >> MBC_ABLK_OFFSET_SHIFT) << ERTS_SACRR_UNIT_SHIFT))))
+		  ((((B)->bhdr & ~BLK_FLG_MASK) >> MBC_ABLK_OFFSET_SHIFT) \
+                      << ERTS_SACRR_UNIT_SHIFT))))
 #  define BLK_TO_MBC(B) (IS_FREE_BLK(B) ? FBLK_TO_MBC(B) : ABLK_TO_MBC(B))
 #else
 #  define FBLK_TO_MBC(B) ((B)->carrier)
@@ -433,8 +456,9 @@ typedef struct {
     ErtsThrPrgrVal thr_prgr;
     erts_atomic_t max_size;
     UWord abandon_limit;
-    UWord blocks;
-    UWord blocks_size;
+    UWord blocks[ERTS_ALC_A_MAX + 1];
+    UWord blocks_size[ERTS_ALC_A_MAX + 1];
+    UWord total_blocks_size;
     enum {
         ERTS_MBC_IS_HOME,
         ERTS_MBC_WAS_POOLED,
@@ -452,7 +476,7 @@ struct Carrier_t_ {
 };
 
 #define ERTS_ALC_CARRIER_TO_ALLCTR(C) \
-  ((Allctr_t *) (erts_atomic_read_nob(&(C)->allctr) & ~FLG_MASK))
+  ((Allctr_t *) (erts_atomic_read_nob(&(C)->allctr) & ~CRR_FLG_MASK))
 
 typedef struct {
     Carrier_t *first;
@@ -530,7 +554,6 @@ typedef struct {
     } head;
 } ErtsAllctrDDQueue_t;
 
-
 typedef struct {
     size_t type_size;
     SWord list_size;
@@ -549,6 +572,7 @@ typedef struct {
 	    UWord used;
 	} cpool;
     } u;
+    ErtsAlcType_t type;
 } ErtsAlcFixList_t;
 
 struct Allctr_t_ {
@@ -569,6 +593,9 @@ struct Allctr_t_ {
     /* Allocator number */
     ErtsAlcType_t	alloc_no;
 
+    /* Allocator strategy */
+    ErtsAlcStrat_t	alloc_strat;
+
     /* Instance index */
     int			ix;
 
@@ -617,6 +644,9 @@ struct Allctr_t_ {
 	AOFF_RBTree_t*   pooled_tree;
 	CarrierList_t	 dc_list;
 
+        /* the sentinel of the cpool we're attached to */
+        ErtsAlcCPoolData_t  *sentinel;
+
 	UWord		abandon_limit;
 	int		disable_abandon;
 	int		check_limit_count;
@@ -624,8 +654,8 @@ struct Allctr_t_ {
         UWord           in_pool_limit;    /* acnl */
         UWord           fblk_min_limit;   /* acmfl */
 	struct {
-	    erts_atomic_t	blocks_size;
-	    erts_atomic_t	no_blocks;
+	    erts_atomic_t	blocks_size[ERTS_ALC_A_MAX + 1];
+	    erts_atomic_t	no_blocks[ERTS_ALC_A_MAX + 1];
 	    erts_atomic_t	carriers_size;
 	    erts_atomic_t	no_carriers;
             CallCounter_t       fail_pooled;
@@ -657,10 +687,12 @@ struct Allctr_t_ {
     void		(*creating_mbc)		(Allctr_t *, Carrier_t *);
     void		(*destroying_mbc)	(Allctr_t *, Carrier_t *);
 
-    /* The three callbacks below are needed to support carrier migration */
+    /* The five callbacks below are needed to support carrier migration. */
     void		(*add_mbc)		(Allctr_t *, Carrier_t *);
     void		(*remove_mbc)	        (Allctr_t *, Carrier_t *);
     UWord		(*largest_fblk_in_mbc)  (Allctr_t *, Carrier_t *);
+    Block_t *           (*first_fblk_in_mbc)     (Allctr_t *, Carrier_t *);
+    Block_t *           (*next_fblk_in_mbc)      (Allctr_t *, Carrier_t *, Block_t *);
 
 #if HAVE_ERTS_MSEG
     void*               (*mseg_alloc)(Allctr_t*, Uint *size_p, Uint flags);
diff --git a/erts/emulator/beam/erl_ao_firstfit_alloc.c b/erts/emulator/beam/erl_ao_firstfit_alloc.c
index 3f0ab33597..c19d6d1b1e 100644
--- a/erts/emulator/beam/erl_ao_firstfit_alloc.c
+++ b/erts/emulator/beam/erl_ao_firstfit_alloc.c
@@ -100,16 +100,18 @@
 
 #define AOFF_BLK_SZ(B) MBC_FBLK_SZ(&(B)->hdr)
 
-#define LIST_NEXT(N) (((AOFF_RBTree_t*)(N))->u.next)
-#define LIST_PREV(N) (((AOFF_RBTree_t*)(N))->parent)
+#define AOFF_LIST_NEXT(N) (((AOFF_RBTree_t*)(N))->u.next)
+#define AOFF_LIST_PREV(N) (((AOFF_RBTree_t*)(N))->parent)
 
 typedef struct AOFF_Carrier_t_ AOFF_Carrier_t;
 
 struct AOFF_Carrier_t_ {
     Carrier_t crr;
-    AOFF_RBTree_t rbt_node;     /* My node in the carrier tree */
-    AOFF_RBTree_t* root;        /* Root of my block tree */
+    AOFF_RBTree_t rbt_node;        /* My node in the carrier tree */
+    AOFF_RBTree_t* root;           /* Root of my block tree */
+    enum AOFFSortOrder blk_order;
 };
+
 #define RBT_NODE_TO_MBC(PTR) ErtsContainerStruct((PTR), AOFF_Carrier_t, rbt_node)
 
 /* 
@@ -152,13 +154,13 @@ static ERTS_INLINE Uint node_max_size(AOFF_RBTree_t *x)
 static ERTS_INLINE void lower_max_size(AOFF_RBTree_t *node,
 				       AOFF_RBTree_t* stop_at)
 {
-    AOFF_RBTree_t* x = node;    
+    AOFF_RBTree_t* x = node;
     Uint old_max = x->max_sz;
     Uint new_max = node_max_size(x);
 
     if (new_max < old_max) {
 	x->max_sz = new_max;
-	while ((x=x->parent) != stop_at && x->max_sz == old_max) {		
+	while ((x=x->parent) != stop_at && x->max_sz == old_max) {
 	    x->max_sz = node_max_size(x);
 	}
 	ASSERT(x == stop_at || x->max_sz > old_max);
@@ -239,6 +241,9 @@ static void aoff_add_mbc(Allctr_t*, Carrier_t*);
 static void aoff_remove_mbc(Allctr_t*, Carrier_t*);
 static UWord aoff_largest_fblk_in_mbc(Allctr_t*, Carrier_t*);
 
+static Block_t *aoff_first_fblk_in_mbc(Allctr_t *, Carrier_t *);
+static Block_t *aoff_next_fblk_in_mbc(Allctr_t *, Carrier_t *, Block_t *);
+
 /* Generic tree functions used by both carrier and block trees. */
 static void rbt_delete(AOFF_RBTree_t** root, AOFF_RBTree_t* del);
 static void rbt_insert(enum AOFFSortOrder, AOFF_RBTree_t** root, AOFF_RBTree_t* blk);
@@ -281,15 +286,28 @@ erts_aoffalc_start(AOFFAllctr_t *alc,
 
     sys_memcpy((void *) alc, (void *) &zero.allctr, sizeof(AOFFAllctr_t));
 
+    if (aoffinit->blk_order == FF_CHAOS) {
+        const enum AOFFSortOrder orders[3] = {FF_AOFF, FF_AOBF, FF_BF};
+        int index = init->ix % (sizeof(orders) / sizeof(orders[0]));
+
+        ASSERT(init->alloc_no == ERTS_ALC_A_TEST);
+        aoffinit->blk_order = orders[index];
+    }
+
+    if (aoffinit->crr_order == FF_CHAOS) {
+        const enum AOFFSortOrder orders[2] = {FF_AGEFF, FF_AOFF};
+        int index = init->ix % (sizeof(orders) / sizeof(orders[0]));
+
+        ASSERT(init->alloc_no == ERTS_ALC_A_TEST);
+        aoffinit->crr_order = orders[index];
+    }
+
     alc->blk_order                      = aoffinit->blk_order;
     alc->crr_order                      = aoffinit->crr_order;
     allctr->mbc_header_size		= sizeof(AOFF_Carrier_t);
     allctr->min_mbc_size		= MIN_MBC_SZ;
     allctr->min_mbc_first_free_size	= MIN_MBC_FIRST_FREE_SZ;
-    allctr->min_block_size = (aoffinit->blk_order == FF_BF
-                              ? (offsetof(AOFF_RBTree_t, u.next)
-                                 + ErtsSizeofMember(AOFF_RBTree_t, u.next))
-                              : offsetof(AOFF_RBTree_t, u));
+    allctr->min_block_size              = sizeof(AOFF_RBTree_t);
 
     allctr->vsn_str			= ERTS_ALC_AOFF_ALLOC_VSN_STR;
 
@@ -311,6 +329,8 @@ erts_aoffalc_start(AOFFAllctr_t *alc,
     allctr->add_mbc                     = aoff_add_mbc;
     allctr->remove_mbc                  = aoff_remove_mbc;
     allctr->largest_fblk_in_mbc         = aoff_largest_fblk_in_mbc;
+    allctr->first_fblk_in_mbc           = aoff_first_fblk_in_mbc;
+    allctr->next_fblk_in_mbc            = aoff_next_fblk_in_mbc;
     allctr->init_atoms			= init_atoms;
 
 #ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
@@ -352,7 +372,7 @@ left_rotate(AOFF_RBTree_t **root, AOFF_RBTree_t *x)
     x->parent = y;
 
     y->max_sz = x->max_sz;
-    x->max_sz = node_max_size(x); 
+    x->max_sz = node_max_size(x);
     ASSERT(y->max_sz >= x->max_sz);
 }
 
@@ -377,7 +397,7 @@ right_rotate(AOFF_RBTree_t **root, AOFF_RBTree_t *x)
     y->right = x;
     x->parent = y;
     y->max_sz = x->max_sz;
-    x->max_sz = node_max_size(x);    
+    x->max_sz = node_max_size(x);
     ASSERT(y->max_sz >= x->max_sz);
 }
 
@@ -512,51 +532,52 @@ tree_insert_fixup(AOFF_RBTree_t** root, AOFF_RBTree_t *blk)
 static void
 aoff_unlink_free_block(Allctr_t *allctr, Block_t *blk)
 {
-    AOFFAllctr_t* alc = (AOFFAllctr_t*)allctr;
     AOFF_RBTree_t* del = (AOFF_RBTree_t*)blk;
     AOFF_Carrier_t *crr = (AOFF_Carrier_t*) FBLK_TO_MBC(&del->hdr);
 
+    (void)allctr;
+
     ASSERT(crr->rbt_node.hdr.bhdr == crr->root->max_sz);
-    HARD_CHECK_TREE(&crr->crr, alc->blk_order, crr->root, 0);
+    HARD_CHECK_TREE(&crr->crr, crr->blk_order, crr->root, 0);
 
-    if (alc->blk_order == FF_BF) {
+    if (crr->blk_order == FF_BF) {
 	ASSERT(del->flags & IS_BF_FLG);
 	if (IS_LIST_ELEM(del)) {
 	    /* Remove from list */
-	    ASSERT(LIST_PREV(del));
-	    ASSERT(LIST_PREV(del)->flags & IS_BF_FLG);
-	    LIST_NEXT(LIST_PREV(del)) = LIST_NEXT(del);
-	    if (LIST_NEXT(del)) {
-		ASSERT(LIST_NEXT(del)->flags & IS_BF_FLG);
-		LIST_PREV(LIST_NEXT(del)) = LIST_PREV(del);
+	    ASSERT(AOFF_LIST_PREV(del));
+	    ASSERT(AOFF_LIST_PREV(del)->flags & IS_BF_FLG);
+	    AOFF_LIST_NEXT(AOFF_LIST_PREV(del)) = AOFF_LIST_NEXT(del);
+	    if (AOFF_LIST_NEXT(del)) {
+		ASSERT(AOFF_LIST_NEXT(del)->flags & IS_BF_FLG);
+		AOFF_LIST_PREV(AOFF_LIST_NEXT(del)) = AOFF_LIST_PREV(del);
 	    }
 	    return;
 	}
-	else if (LIST_NEXT(del)) {
+	else if (AOFF_LIST_NEXT(del)) {
 	    /* Replace tree node by next element in list... */
 	    
-	    ASSERT(AOFF_BLK_SZ(LIST_NEXT(del)) == AOFF_BLK_SZ(del));
-	    ASSERT(IS_LIST_ELEM(LIST_NEXT(del)));
-	    
-	    replace(&crr->root, (AOFF_RBTree_t*)del, LIST_NEXT(del));
-	    
-	    HARD_CHECK_TREE(&crr->crr, alc->blk_order, crr->root, 0);
+	    ASSERT(AOFF_BLK_SZ(AOFF_LIST_NEXT(del)) == AOFF_BLK_SZ(del));
+	    ASSERT(IS_LIST_ELEM(AOFF_LIST_NEXT(del)));
+
+	    replace(&crr->root, (AOFF_RBTree_t*)del, AOFF_LIST_NEXT(del));
+
+	    HARD_CHECK_TREE(&crr->crr, crr->blk_order, crr->root, 0);
 	    return;
 	}
     }
 
     rbt_delete(&crr->root, (AOFF_RBTree_t*)del);
 
-    HARD_CHECK_TREE(&crr->crr, alc->blk_order, crr->root, 0);
+    HARD_CHECK_TREE(&crr->crr, crr->blk_order, crr->root, 0);
 
     /* Update the carrier tree with a potentially new (lower) max_sz
-     */    
+     */
     if (crr->root) {
 	if (crr->rbt_node.hdr.bhdr == crr->root->max_sz) {
 	    return;
 	}
 	ASSERT(crr->rbt_node.hdr.bhdr > crr->root->max_sz);
-	crr->rbt_node.hdr.bhdr = crr->root->max_sz; 
+	crr->rbt_node.hdr.bhdr = crr->root->max_sz;
     }
     else {
 	crr->rbt_node.hdr.bhdr = 0;
@@ -737,17 +758,18 @@ rbt_delete(AOFF_RBTree_t** root, AOFF_RBTree_t* del)
 static void
 aoff_link_free_block(Allctr_t *allctr, Block_t *block)
 {
-    AOFFAllctr_t* alc = (AOFFAllctr_t*) allctr;
     AOFF_RBTree_t *blk = (AOFF_RBTree_t *) block;
     AOFF_RBTree_t *crr_node;
     AOFF_Carrier_t *blk_crr = (AOFF_Carrier_t*) FBLK_TO_MBC(block);
     Uint blk_sz = AOFF_BLK_SZ(blk);
 
+    (void)allctr;
+
     ASSERT(allctr == ERTS_ALC_CARRIER_TO_ALLCTR(&blk_crr->crr));
     ASSERT(blk_crr->rbt_node.hdr.bhdr == (blk_crr->root ? blk_crr->root->max_sz : 0));
-    HARD_CHECK_TREE(&blk_crr->crr, alc->blk_order, blk_crr->root, 0);
+    HARD_CHECK_TREE(&blk_crr->crr, blk_crr->blk_order, blk_crr->root, 0);
 
-    rbt_insert(alc->blk_order, &blk_crr->root, blk);
+    rbt_insert(blk_crr->blk_order, &blk_crr->root, blk);
 
     /*
      * Update carrier tree with a potentially new (larger) max_sz
@@ -773,7 +795,7 @@ rbt_insert(enum AOFFSortOrder order, AOFF_RBTree_t** root, AOFF_RBTree_t* blk)
 #ifdef DEBUG
     blk->flags  = (order == FF_BF) ? IS_BF_FLG : 0;
 #else
-    blk->flags  = 0; 
+    blk->flags  = 0;
 #endif
     blk->left	= NULL;
     blk->right	= NULL;
@@ -787,7 +809,7 @@ rbt_insert(enum AOFFSortOrder order, AOFF_RBTree_t** root, AOFF_RBTree_t* blk)
     else {
 	AOFF_RBTree_t *x = *root;
 	while (1) {
-	    SWord diff; 
+	    SWord diff;
 	    if (x->max_sz < blk_sz) {
 		x->max_sz = blk_sz;
 	    }
@@ -810,14 +832,14 @@ rbt_insert(enum AOFFSortOrder order, AOFF_RBTree_t** root, AOFF_RBTree_t* blk)
 	    }
 	    else {
 		ASSERT(order == FF_BF);
-		ASSERT(blk->flags & IS_BF_FLG);			    
-		ASSERT(x->flags & IS_BF_FLG);			    
+		ASSERT(blk->flags & IS_BF_FLG);
+		ASSERT(x->flags & IS_BF_FLG);
 		SET_LIST_ELEM(blk);
-		LIST_NEXT(blk) = LIST_NEXT(x);
-		LIST_PREV(blk) = x;
-		if (LIST_NEXT(x))
-		    LIST_PREV(LIST_NEXT(x)) = blk;
-		LIST_NEXT(x) = blk;
+		AOFF_LIST_NEXT(blk) = AOFF_LIST_NEXT(x);
+		AOFF_LIST_PREV(blk) = x;
+		if (AOFF_LIST_NEXT(x))
+		    AOFF_LIST_PREV(AOFF_LIST_NEXT(x)) = blk;
+		AOFF_LIST_NEXT(x) = blk;
 		return;
 	    }
 	}
@@ -831,7 +853,7 @@ rbt_insert(enum AOFFSortOrder order, AOFF_RBTree_t** root, AOFF_RBTree_t* blk)
     }
     if (order == FF_BF) {
 	SET_TREE_NODE(blk);
-	LIST_NEXT(blk) = NULL;
+	AOFF_LIST_NEXT(blk) = NULL;
     }
 }
 
@@ -878,7 +900,7 @@ aoff_get_free_block(Allctr_t *allctr, Uint size,
 #ifdef HARD_DEBUG
     AOFF_RBTree_t* dbg_blk;
 #endif
-    
+
     ASSERT(!cand_blk || cand_size >= size);
 
     /* Get first-fit carrier
@@ -891,7 +913,7 @@ aoff_get_free_block(Allctr_t *allctr, Uint size,
     /* Get block within carrier tree
      */
 #ifdef HARD_DEBUG
-    dbg_blk = HARD_CHECK_TREE(&crr->crr, alc->blk_order, crr->root, size);
+    dbg_blk = HARD_CHECK_TREE(&crr->crr, crr->blk_order, crr->root, size);
 #endif
 
     blk = rbt_search(crr->root, size);
@@ -904,7 +926,7 @@ aoff_get_free_block(Allctr_t *allctr, Uint size,
     if (!blk)
 	return NULL;
 
-    if (cand_blk && cmp_cand_blk(alc->blk_order, cand_blk, blk) < 0) {
+    if (cand_blk && cmp_cand_blk(crr->blk_order, cand_blk, blk) < 0) {
 	return NULL; /* cand_blk was better */
     }
 
@@ -927,21 +949,28 @@ static void aoff_creating_mbc(Allctr_t *allctr, Carrier_t *carrier)
     AOFFAllctr_t *alc = (AOFFAllctr_t *) allctr;
     AOFF_Carrier_t *crr = (AOFF_Carrier_t*) carrier;
     AOFF_RBTree_t **root = &alc->mbc_root;
+    Sint64 bt = get_birth_time();
 
     HARD_CHECK_TREE(NULL, alc->crr_order, *root, 0);
 
     crr->rbt_node.hdr.bhdr = 0;
-    if (alc->crr_order == FF_AGEFF || IS_DEBUG) {
-        Sint64 bt = get_birth_time();
-        crr->rbt_node.u.birth_time = bt;
-        crr->crr.cpool.pooled.u.birth_time = bt;
-    }
+
+    /* While birth time is only used for FF_AGEFF, we have to set it for all
+     * types as we can be migrated to an instance that uses it and we don't
+     * want to mess its order up. */
+    crr->rbt_node.u.birth_time = bt;
+    crr->crr.cpool.pooled.u.birth_time = bt;
+
     rbt_insert(alc->crr_order, root, &crr->rbt_node);
 
     /* aoff_link_free_block will add free block later */
     crr->root = NULL;
 
     HARD_CHECK_TREE(NULL, alc->crr_order, *root, 0);
+
+    /* When a carrier has been migrated, its block order may differ from that
+     * of the allocator it's been migrated to. */
+    crr->blk_order = alc->blk_order;
 }
 
 #define IS_CRR_IN_TREE(CRR,ROOT) \
@@ -964,7 +993,7 @@ static void aoff_add_mbc(Allctr_t *allctr, Carrier_t *carrier)
     AOFF_RBTree_t **root = &alc->mbc_root;
 
     ASSERT(!IS_CRR_IN_TREE(crr, *root));
-    HARD_CHECK_TREE(NULL, alc->crr_order, *root, 0);   
+    HARD_CHECK_TREE(NULL, alc->crr_order, *root, 0);
 
     rbt_insert(alc->crr_order, root, &crr->rbt_node);
 
@@ -1034,6 +1063,62 @@ static UWord aoff_largest_fblk_in_mbc(Allctr_t* allctr, Carrier_t* carrier)
     return crr->rbt_node.hdr.bhdr;
 }
 
+static Block_t *aoff_first_fblk_in_mbc(Allctr_t *allctr, Carrier_t *carrier)
+{
+    AOFF_Carrier_t *crr = (AOFF_Carrier_t*)carrier;
+
+    (void)allctr;
+
+    if (crr->root) {
+        AOFF_RBTree_t *blk;
+
+        /* Descend to the rightmost block of the tree. */
+        for (blk = crr->root; blk->right; blk = blk->right);
+
+        return (Block_t*)blk;
+    }
+
+    return NULL;
+}
+
+static Block_t *aoff_next_fblk_in_mbc(Allctr_t *allctr, Carrier_t *carrier,
+                                      Block_t *block)
+{
+    AOFF_RBTree_t *parent, *blk;
+
+    (void)allctr;
+    (void)carrier;
+
+    blk = (AOFF_RBTree_t*)block;
+
+    if (blk->left) {
+        /* Descend to the rightmost block of the left subtree. */
+        for (blk = blk->left; blk->right; blk = blk->right);
+
+        return (Block_t*)blk;
+    }
+
+    while (blk->parent) {
+        parent = blk->parent;
+
+        /* If we ascend from the right we know we haven't visited our parent
+         * yet, because we always descend as far as we can to the right when
+         * entering a subtree. */
+        if (parent->right == blk) {
+            ASSERT(parent->left != blk);
+            return (Block_t*)parent;
+        }
+
+        /* If we ascend from the left we know we've already visited our
+         * parent, and will need to keep ascending until we do so from the
+         * right or reach the end of the tree. */
+        ASSERT(parent->left == blk);
+        blk = parent;
+    }
+
+    return NULL;
+}
+
 /*
  * info_options()
  */
@@ -1105,7 +1190,7 @@ info_options(Allctr_t *allctr,
     }
 
     if (hpp || szp) {
-	
+
 	if (!atoms_initialized)
 	    erts_exit(ERTS_ERROR_EXIT, "%s:%d: Internal error: Atoms not initialized",
 		     __FILE__, __LINE__);;
@@ -1132,7 +1217,7 @@ erts_aoffalc_test(UWord op, UWord a1, UWord a2)
     switch (op) {
     case 0x500: return (UWord) ((AOFFAllctr_t *) a1)->blk_order == FF_AOBF;
     case 0x501: {
-	AOFF_RBTree_t *node = ((AOFFAllctr_t *) a1)->mbc_root; 
+	AOFF_RBTree_t *node = ((AOFFAllctr_t *) a1)->mbc_root;
 	Uint size = (Uint) a2;
 	node = node ? rbt_search(node, size) : NULL;
 	return (UWord) (node ? RBT_NODE_TO_MBC(node)->root : NULL);
@@ -1140,13 +1225,13 @@ erts_aoffalc_test(UWord op, UWord a1, UWord a2)
     case 0x502:	return (UWord) ((AOFF_RBTree_t *) a1)->parent;
     case 0x503:	return (UWord) ((AOFF_RBTree_t *) a1)->left;
     case 0x504:	return (UWord) ((AOFF_RBTree_t *) a1)->right;
-    case 0x505:	return (UWord) LIST_NEXT(a1);
+    case 0x505:	return (UWord) AOFF_LIST_NEXT(a1);
     case 0x506:	return (UWord) IS_BLACK((AOFF_RBTree_t *) a1);
     case 0x507:	return (UWord) IS_TREE_NODE((AOFF_RBTree_t *) a1);
     case 0x508: return (UWord) 0; /* IS_BF_ALGO */
     case 0x509: return (UWord) ((AOFF_RBTree_t *) a1)->max_sz;
     case 0x50a: return (UWord) ((AOFFAllctr_t *) a1)->blk_order == FF_BF;
-    case 0x50b:	return (UWord) LIST_PREV(a1);
+    case 0x50b:	return (UWord) AOFF_LIST_PREV(a1);
     default:	ASSERT(0); return ~((UWord) 0);
     }
 }
@@ -1166,7 +1251,7 @@ static int rbt_is_member(AOFF_RBTree_t* root, AOFF_RBTree_t* node)
             return 0;
         }
 	node = node->parent;
-    }    
+    }
     return 1;
 }
 
@@ -1279,15 +1364,15 @@ check_tree(Carrier_t* within_crr, enum AOFFSortOrder order, AOFF_RBTree_t* root,
 	}
 	if (order == FF_BF) {
 	    AOFF_RBTree_t* y = x;
-	    AOFF_RBTree_t* nxt = LIST_NEXT(y);
+	    AOFF_RBTree_t* nxt = AOFF_LIST_NEXT(y);
 	    ASSERT(IS_TREE_NODE(x));
 	    while (nxt) {
 		ASSERT(IS_LIST_ELEM(nxt));
 		ASSERT(AOFF_BLK_SZ(nxt) == AOFF_BLK_SZ(x));
 		ASSERT(FBLK_TO_MBC(&nxt->hdr) == within_crr);
-		ASSERT(LIST_PREV(nxt) == y);
+		ASSERT(AOFF_LIST_PREV(nxt) == y);
 		y = nxt;
-		nxt = LIST_NEXT(nxt);
+		nxt = AOFF_LIST_NEXT(nxt);
 	    }
 	}
 
@@ -1301,13 +1386,13 @@ check_tree(Carrier_t* within_crr, enum AOFFSortOrder order, AOFF_RBTree_t* root,
 	if (x->left) {
 	    ASSERT(x->left->parent == x);
 	    ASSERT(cmp_blocks(order, x->left, x) < 0);
-	    ASSERT(x->left->max_sz <= x->max_sz);	    
+	    ASSERT(x->left->max_sz <= x->max_sz);
 	}
 
 	if (x->right) {
 	    ASSERT(x->right->parent == x);
 	    ASSERT(cmp_blocks(order, x->right, x) > 0);
-	    ASSERT(x->right->max_sz <= x->max_sz);	    
+	    ASSERT(x->right->max_sz <= x->max_sz);
 	}
 	ASSERT(x->max_sz >= AOFF_BLK_SZ(x));
 	ASSERT(x->max_sz == AOFF_BLK_SZ(x)
@@ -1327,7 +1412,7 @@ check_tree(Carrier_t* within_crr, enum AOFFSortOrder order, AOFF_RBTree_t* root,
 	x = x->parent;
 	--depth;
     }
-    ASSERT(depth == 0 || (!root && depth==1)); 
+    ASSERT(depth == 0 || (!root && depth==1));
     ASSERT(curr_blacks == 0);
     ASSERT((1 << (max_depth/2)) <= node_cnt);
 
@@ -1373,4 +1458,3 @@ print_tree(AOFF_RBTree_t* root)
 #endif /* PRINT_TREE */
 
 #endif /* HARD_DEBUG */
-
diff --git a/erts/emulator/beam/erl_ao_firstfit_alloc.h b/erts/emulator/beam/erl_ao_firstfit_alloc.h
index 68df9e0a49..9c9b98da86 100644
--- a/erts/emulator/beam/erl_ao_firstfit_alloc.h
+++ b/erts/emulator/beam/erl_ao_firstfit_alloc.h
@@ -32,7 +32,12 @@ enum AOFFSortOrder {
     FF_AGEFF = 0,    /* carrier trees only */
     FF_AOFF  = 1,
     FF_AOBF  = 2,    /* block trees only */
-    FF_BF    = 3     /* block trees only */
+    FF_BF    = 3,    /* block trees only */
+
+    FF_CHAOS = -1    /* A test-specific sort order that picks any of the above
+                      * after instance id. Used to test that carriers created
+                      * under one order will work fine after being migrated
+                      * to another. */
 };
 
 typedef struct {
diff --git a/erts/emulator/beam/erl_arith.c b/erts/emulator/beam/erl_arith.c
index 144fb56ea5..68d1cd989e 100644
--- a/erts/emulator/beam/erl_arith.c
+++ b/erts/emulator/beam/erl_arith.c
@@ -52,19 +52,11 @@ static ERTS_INLINE void maybe_shrink(Process* p, Eterm* hp, Eterm res, Uint allo
     Uint actual;
 
     if (is_immed(res)) {
-	if (p->heap <= hp && hp < p->htop) {
-	    p->htop = hp;
-	}
-	else {
-	    erts_heap_frag_shrink(p, hp);
-	}
+        ASSERT(!(p->heap <= hp && hp < p->htop));
+        erts_heap_frag_shrink(p, hp);
     } else if ((actual = bignum_header_arity(*hp)+1) < alloc) {
-	if (p->heap <= hp && hp < p->htop) {
-	    p->htop = hp+actual;
-	}
-	else {
-	    erts_heap_frag_shrink(p, hp+actual);
-	}
+        ASSERT(!(p->heap <= hp && hp < p->htop));
+        erts_heap_frag_shrink(p, hp+actual);
     }
 }
 
@@ -246,7 +238,7 @@ shift(Process* p, Eterm arg1, Eterm arg2, int right)
 		    BIF_ERROR(p, SYSTEM_LIMIT);
 		}
 		need = BIG_NEED_SIZE(ires+1);
-		bigp = HAlloc(p, need);
+		bigp = HeapFragOnlyAlloc(p, need);
 		arg1 = big_lshift(arg1, i, bigp);
 		maybe_shrink(p, bigp, arg1, need);
 		if (is_nil(arg1)) {
@@ -298,7 +290,7 @@ BIF_RETTYPE bnot_1(BIF_ALIST_1)
 	ret = make_small(~signed_val(BIF_ARG_1));
     } else if (is_big(BIF_ARG_1)) {
 	Uint need = BIG_NEED_SIZE(big_size(BIF_ARG_1)+1);
-	Eterm* bigp = HAlloc(BIF_P, need);
+	Eterm* bigp = HeapFragOnlyAlloc(BIF_P, need);
 
 	ret = big_bnot(BIF_ARG_1, bigp);
 	maybe_shrink(BIF_P, bigp, ret, need);
@@ -343,7 +335,7 @@ erts_mixed_plus(Process* p, Eterm arg1, Eterm arg2)
 		    if (IS_SSMALL(ires)) {
 			return make_small(ires);
 		    } else {
-			hp = HAlloc(p, 2);
+			hp = HeapFragOnlyAlloc(p, 2);
 			res = small_to_big(ires, hp);
 			return res;
 		    }
@@ -400,7 +392,7 @@ erts_mixed_plus(Process* p, Eterm arg1, Eterm arg2)
 		    sz2 = big_size(arg2);
 		    sz = MAX(sz1, sz2)+1;
 		    need_heap = BIG_NEED_SIZE(sz);
-		    hp = HAlloc(p, need_heap);
+		    hp = HeapFragOnlyAlloc(p, need_heap);
 		    res = big_plus(arg1, arg2, hp);
 		    maybe_shrink(p, hp, res, need_heap);
 		    if (is_nil(res)) {
@@ -446,7 +438,7 @@ erts_mixed_plus(Process* p, Eterm arg1, Eterm arg2)
 		do_float:
 		    f1.fd = f1.fd + f2.fd;
 		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    hp = HAlloc(p, FLOAT_SIZE_OBJECT);
+		    hp = HeapFragOnlyAlloc(p, FLOAT_SIZE_OBJECT);
 		    res = make_float(hp);
 		    PUT_DOUBLE(f1, hp);
 		    return res;
@@ -488,7 +480,7 @@ erts_mixed_minus(Process* p, Eterm arg1, Eterm arg2)
 		    if (IS_SSMALL(ires)) {
 			return make_small(ires);
 		    } else {
-			hp = HAlloc(p, 2);
+			hp = HeapFragOnlyAlloc(p, 2);
 			res = small_to_big(ires, hp);
 			return res;
 		    }
@@ -534,7 +526,7 @@ erts_mixed_minus(Process* p, Eterm arg1, Eterm arg2)
 		    sz2 = big_size(arg2);
 		    sz = MAX(sz1, sz2)+1;
 		    need_heap = BIG_NEED_SIZE(sz);
-		    hp = HAlloc(p, need_heap);
+		    hp = HeapFragOnlyAlloc(p, need_heap);
 		    res = big_minus(arg1, arg2, hp);
                     maybe_shrink(p, hp, res, need_heap);
 		    if (is_nil(res)) {
@@ -589,7 +581,7 @@ erts_mixed_minus(Process* p, Eterm arg1, Eterm arg2)
 		do_float:
 		    f1.fd = f1.fd - f2.fd;
 		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    hp = HAlloc(p, FLOAT_SIZE_OBJECT);
+		    hp = HeapFragOnlyAlloc(p, FLOAT_SIZE_OBJECT);
 		    res = make_float(hp);
 		    PUT_DOUBLE(f1, hp);
 		    return res;
@@ -657,7 +649,7 @@ erts_mixed_times(Process* p, Eterm arg1, Eterm arg2)
 			    hdr = big_res[0];
 			    arity = bignum_header_arity(hdr);
 			    ASSERT(arity == 1 || arity == 2);
-			    hp = HAlloc(p, arity+1);
+			    hp = HeapFragOnlyAlloc(p, arity+1);
 			    res = make_big(hp);
 			    *hp++ = hdr;
 			    *hp++ = big_res[1];
@@ -726,7 +718,7 @@ erts_mixed_times(Process* p, Eterm arg1, Eterm arg2)
 
 		do_big:
 		    need_heap = BIG_NEED_SIZE(sz);
-                    hp = HAlloc(p, need_heap);
+                    hp = HeapFragOnlyAlloc(p, need_heap);
 		    res = big_times(arg1, arg2, hp);
 
 		    /*
@@ -779,7 +771,7 @@ erts_mixed_times(Process* p, Eterm arg1, Eterm arg2)
 		do_float:
 		    f1.fd = f1.fd * f2.fd;
 		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    hp = HAlloc(p, FLOAT_SIZE_OBJECT);
+		    hp = HeapFragOnlyAlloc(p, FLOAT_SIZE_OBJECT);
 		    res = make_float(hp);
 		    PUT_DOUBLE(f1, hp);
 		    return res;
@@ -905,7 +897,7 @@ erts_mixed_div(Process* p, Eterm arg1, Eterm arg2)
 		do_float:
 		    f1.fd = f1.fd / f2.fd;
 		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    hp = HAlloc(p, FLOAT_SIZE_OBJECT);
+		    hp = HeapFragOnlyAlloc(p, FLOAT_SIZE_OBJECT);
 		    PUT_DOUBLE(f1, hp);
 		    return make_float(hp);
 		default:
@@ -957,7 +949,7 @@ erts_int_div(Process* p, Eterm arg1, Eterm arg2)
 
 	    ires = big_size(arg2);
 	    need = BIG_NEED_SIZE(i-ires+1) + BIG_NEED_SIZE(i);
-	    hp = HAlloc(p, need);
+	    hp = HeapFragOnlyAlloc(p, need);
 	    arg1 = big_div(arg1, arg2, hp);
 	    maybe_shrink(p, hp, arg1, need);
 	    if (is_nil(arg1)) {
@@ -1004,7 +996,7 @@ erts_int_rem(Process* p, Eterm arg1, Eterm arg2)
 	    arg1 = SMALL_ZERO;
 	} else if (ires > 0) {
 	    Uint need = BIG_NEED_SIZE(big_size(arg1));
-	    Eterm* hp = HAlloc(p, need);
+	    Eterm* hp = HeapFragOnlyAlloc(p, need);
 
 	    arg1 = big_rem(arg1, arg2, hp);
 	    maybe_shrink(p, hp, arg1, need);
@@ -1041,7 +1033,7 @@ Eterm erts_band(Process* p, Eterm arg1, Eterm arg2)
 	return THE_NON_VALUE;
     }
     need = BIG_NEED_SIZE(MAX(big_size(arg1), big_size(arg2)) + 1);
-    hp = HAlloc(p, need);
+    hp = HeapFragOnlyAlloc(p, need);
     arg1 = big_band(arg1, arg2, hp);
     ASSERT(is_not_nil(arg1));
     maybe_shrink(p, hp, arg1, need);
@@ -1069,7 +1061,7 @@ Eterm erts_bor(Process* p, Eterm arg1, Eterm arg2)
 	return THE_NON_VALUE;
     }
     need = BIG_NEED_SIZE(MAX(big_size(arg1), big_size(arg2)) + 1);
-    hp = HAlloc(p, need);
+    hp = HeapFragOnlyAlloc(p, need);
     arg1 = big_bor(arg1, arg2, hp);
     ASSERT(is_not_nil(arg1));
     maybe_shrink(p, hp, arg1, need);
@@ -1097,7 +1089,7 @@ Eterm erts_bxor(Process* p, Eterm arg1, Eterm arg2)
 	return THE_NON_VALUE;
     }
     need = BIG_NEED_SIZE(MAX(big_size(arg1), big_size(arg2)) + 1);
-    hp = HAlloc(p, need);
+    hp = HeapFragOnlyAlloc(p, need);
     arg1 = big_bxor(arg1, arg2, hp);
     ASSERT(is_not_nil(arg1));
     maybe_shrink(p, hp, arg1, need);
@@ -1110,7 +1102,7 @@ Eterm erts_bnot(Process* p, Eterm arg)
 
     if (is_big(arg)) {
 	Uint need = BIG_NEED_SIZE(big_size(arg)+1);
-	Eterm* bigp = HAlloc(p, need);
+	Eterm* bigp = HeapFragOnlyAlloc(p, need);
 
 	ret = big_bnot(arg, bigp);
 	maybe_shrink(p, bigp, ret, need);
@@ -1125,924 +1117,6 @@ Eterm erts_bnot(Process* p, Eterm arg)
     return ret;
 } 
 
-#define ERTS_NEED_GC(p, need) ((HEAP_LIMIT((p)) - HEAP_TOP((p))) <= (need))
-
-static ERTS_INLINE void
-trim_heap(Process* p, Eterm* hp, Eterm res)
-{
-    if (is_immed(res)) {
-	ASSERT(p->heap <= hp && hp <= p->htop);
-	p->htop = hp;
-    } else {
-	Eterm* new_htop;
-	ASSERT(is_big(res));
-	new_htop = hp + bignum_header_arity(*hp) + 1;
-	ASSERT(p->heap <= new_htop && new_htop <= p->htop);
-	p->htop = new_htop;
-    }
-    ASSERT(p->heap <= p->htop && p->htop <= p->stop);
-}
-
-/*
- * The functions that follow are called from the emulator loop.
- * They are not allowed to allocate heap fragments, but must do
- * a garbage collection if there is insufficient heap space.
- */
-
-#define erts_heap_frag_shrink horrible error
-#define maybe_shrink horrible error
-
-Eterm
-erts_gc_mixed_plus(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    Eterm res;
-    Eterm hdr;
-    FloatDef f1, f2;
-    dsize_t sz1, sz2, sz;
-    int need_heap;
-    Eterm* hp;
-    Sint ires;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    ERTS_FP_CHECK_INIT(p);
-    switch (arg1 & _TAG_PRIMARY_MASK) {
-    case TAG_PRIMARY_IMMED1:
-	switch ((arg1 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    ires = signed_val(arg1) + signed_val(arg2);
-		    if (IS_SSMALL(ires)) {
-			return make_small(ires);
-		    } else {
-			if (ERTS_NEED_GC(p, 2)) {
-			    erts_garbage_collect(p, 2, reg, live);
-			}
-			hp = p->htop;
-			p->htop += 2;
-			res = small_to_big(ires, hp);
-			return res;
-		    }
-		default:
-		badarith:
-		    p->freason = BADARITH;
-		    return THE_NON_VALUE;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    if (arg1 == SMALL_ZERO) {
-			return arg2;
-		    }
-		    arg1 = small_to_big(signed_val(arg1), tmp_big1);
-		    goto do_big;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	default:
-	    goto badarith;
-	}
-    case TAG_PRIMARY_BOXED:
-	hdr = *boxed_val(arg1);
-	switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-	case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if (arg2 == SMALL_ZERO) {
-			return arg1;
-		    }
-		    arg2 = small_to_big(signed_val(arg2), tmp_big2);
-		    goto do_big;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		do_big:
-		    sz1 = big_size(arg1);
-		    sz2 = big_size(arg2);
-		    sz = MAX(sz1, sz2)+1;
-		    need_heap = BIG_NEED_SIZE(sz);
-		    if (ERTS_NEED_GC(p, need_heap)) {
-			erts_garbage_collect(p, need_heap, reg, live+2);
-			if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-			    arg1 = reg[live];
-			}
-			if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-			    arg2 = reg[live+1];
-			}
-		    }
-		    hp = p->htop;
-		    p->htop += need_heap;
-		    res = big_plus(arg1, arg2, hp);
-		    trim_heap(p, hp, res);
-		    if (is_nil(res)) {
-			p->freason = SYSTEM_LIMIT;
-			return THE_NON_VALUE;
-		    }
-		    return res;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    GET_DOUBLE(arg2, f2);
-
-		do_float:
-		    f1.fd = f1.fd + f2.fd;
-		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-			erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live);
-		    }
-		    hp = p->htop;
-		    p->htop += FLOAT_SIZE_OBJECT;
-		    res = make_float(hp);
-		    PUT_DOUBLE(f1, hp);
-		    return res;
-		default:
-		    goto badarith;
-		}
-	    default:
-		goto badarith;
-	    }
-	}
-    default:
-	goto badarith;
-    }
-}
-
-Eterm
-erts_gc_mixed_minus(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    Eterm hdr;
-    Eterm res;
-    FloatDef f1, f2;
-    dsize_t sz1, sz2, sz;
-    int need_heap;
-    Eterm* hp;
-    Sint ires;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    ERTS_FP_CHECK_INIT(p);
-    switch (arg1 & _TAG_PRIMARY_MASK) {
-    case TAG_PRIMARY_IMMED1:
-	switch ((arg1 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    ires = signed_val(arg1) - signed_val(arg2);
-		    if (IS_SSMALL(ires)) {
-			return make_small(ires);
-		    } else {
-			if (ERTS_NEED_GC(p, 2)) {
-			    erts_garbage_collect(p, 2, reg, live);
-			}
-			hp = p->htop;
-			p->htop += 2;
-			res = small_to_big(ires, hp);
-			return res;
-		    }
-		default:
-		badarith:
-		    p->freason = BADARITH;
-		    return THE_NON_VALUE;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    arg1 = small_to_big(signed_val(arg1), tmp_big1);
-		    goto do_big;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	default:
-	    goto badarith;
-	}
-    case TAG_PRIMARY_BOXED:
-	hdr = *boxed_val(arg1);
-	switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-	case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if (arg2 == SMALL_ZERO) {
-			return arg1;
-		    }
-		    arg2 = small_to_big(signed_val(arg2), tmp_big2);
-
-		do_big:
-		    sz1 = big_size(arg1);
-		    sz2 = big_size(arg2);
-		    sz = MAX(sz1, sz2)+1;
-		    need_heap = BIG_NEED_SIZE(sz);
-		    if (ERTS_NEED_GC(p, need_heap)) {
-			erts_garbage_collect(p, need_heap, reg, live+2);
-			if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-			    arg1 = reg[live];
-			}
-			if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-			    arg2 = reg[live+1];
-			}
-		    }
-		    hp = p->htop;
-		    p->htop += need_heap;
-		    res = big_minus(arg1, arg2, hp);
-                    trim_heap(p, hp, res);
-		    if (is_nil(res)) {
-			p->freason = SYSTEM_LIMIT;
-			return THE_NON_VALUE;
-		    }
-		    return res;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    goto do_big;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    GET_DOUBLE(arg2, f2);
-
-		do_float:
-		    f1.fd = f1.fd - f2.fd;
-		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-			erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live);
-		    }
-		    hp = p->htop;
-		    p->htop += FLOAT_SIZE_OBJECT;
-		    res = make_float(hp);
-		    PUT_DOUBLE(f1, hp);
-		    return res;
-		default:
-		    goto badarith;
-		}
-	    default:
-		goto badarith;
-	    }
-	}
-    default:
-	goto badarith;
-    }
-}
-
-Eterm
-erts_gc_mixed_times(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    Eterm hdr;
-    Eterm res;
-    FloatDef f1, f2;
-    dsize_t sz1, sz2, sz;
-    int need_heap;
-    Eterm* hp;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    ERTS_FP_CHECK_INIT(p);
-    switch (arg1 & _TAG_PRIMARY_MASK) {
-    case TAG_PRIMARY_IMMED1:
-	switch ((arg1 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if ((arg1 == SMALL_ZERO) || (arg2 == SMALL_ZERO)) {
-			return(SMALL_ZERO);
-		    } else if (arg1 == SMALL_ONE) {
-			return(arg2);
-		    } else if (arg2 == SMALL_ONE) {
-			return(arg1);
-		    } else {
-			DeclareTmpHeap(big_res,3,p);
-			UseTmpHeap(3,p);
-
-			/*
-			 * The following code is optimized for the case that
-			 * result is small (which should be the most common case
-			 * in practice).
-			 */
-			res = small_times(signed_val(arg1), signed_val(arg2),
-					  big_res);
-			if (is_small(res)) {
-			    UnUseTmpHeap(3,p);
-			    return res;
-			} else {
-			    /*
-			     * The result is a a big number.
-			     * Allocate a heap fragment and copy the result.
-			     * Be careful to allocate exactly what we need
-			     * to not leave any holes.
-			     */
-			    Uint arity;
-			    Uint need;
-			    
-			    ASSERT(is_big(res));
-			    hdr = big_res[0];
-			    arity = bignum_header_arity(hdr);
-			    ASSERT(arity == 1 || arity == 2);
-			    need = arity + 1;
-			    if (ERTS_NEED_GC(p, need)) {
-				erts_garbage_collect(p, need, reg, live);
-			    }
-			    hp = p->htop;
-			    p->htop += need;
-			    res = make_big(hp);
-			    *hp++ = hdr;
-			    *hp++ = big_res[1];
-			    if (arity > 1) {
-				*hp = big_res[2];
-			    }
-			    UnUseTmpHeap(3,p);
-			    return res;
-			}
-		    }
-		default:
-		badarith:
-		    p->freason = BADARITH;
-		    return THE_NON_VALUE;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    if (arg1 == SMALL_ZERO)
-			return(SMALL_ZERO);
-		    if (arg1 == SMALL_ONE)
-			return(arg2);
-		    arg1 = small_to_big(signed_val(arg1), tmp_big1);
-		    sz = 2 + big_size(arg2);
-		    goto do_big;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	default:
-	    goto badarith;
-	}
-    case TAG_PRIMARY_BOXED:
-	hdr = *boxed_val(arg1);
-	switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-	case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if (arg2 == SMALL_ZERO)
-			return(SMALL_ZERO);
-		    if (arg2 == SMALL_ONE)
-			return(arg1);
-		    arg2 = small_to_big(signed_val(arg2), tmp_big2);
-		    sz = 2 + big_size(arg1);
-		    goto do_big;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    sz1 = big_size(arg1);
-		    sz2 = big_size(arg2);
-		    sz = sz1 + sz2;
-
-		do_big:
-		    need_heap = BIG_NEED_SIZE(sz);
-		    if (ERTS_NEED_GC(p, need_heap)) {
-			erts_garbage_collect(p, need_heap, reg, live+2);
-			if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-			    arg1 = reg[live];
-			}
-			if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-			    arg2 = reg[live+1];
-			}
-		    }
-		    hp = p->htop;
-		    p->htop += need_heap;
-		    res = big_times(arg1, arg2, hp);
-		    trim_heap(p, hp, res);
-
-		    /*
-		     * Note that the result must be big in this case, since
-		     * at least one operand was big to begin with, and
-		     * the absolute value of the other is > 1.
-		     */
-
-		    if (is_nil(res)) {
-			p->freason = SYSTEM_LIMIT;
-			return THE_NON_VALUE;
-		    }
-		    return res;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    GET_DOUBLE(arg2, f2);
-
-		do_float:
-		    f1.fd = f1.fd * f2.fd;
-		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-			erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live);
-		    }
-		    hp = p->htop;
-		    p->htop += FLOAT_SIZE_OBJECT;
-		    res = make_float(hp);
-		    PUT_DOUBLE(f1, hp);
-		    return res;
-		default:
-		    goto badarith;
-		}
-	    default:
-		goto badarith;
-	    }
-	}
-    default:
-	goto badarith;
-    }
-}
-
-Eterm
-erts_gc_mixed_div(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    FloatDef f1, f2;
-    Eterm* hp;
-    Eterm hdr;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    ERTS_FP_CHECK_INIT(p);
-    switch (arg1 & _TAG_PRIMARY_MASK) {
-    case TAG_PRIMARY_IMMED1:
-	switch ((arg1 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		badarith:
-		    p->freason = BADARITH;
-		    return THE_NON_VALUE;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	default:
-	    goto badarith;
-	}
-    case TAG_PRIMARY_BOXED:
-	hdr = *boxed_val(arg1);
-	switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-	case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0 ||
-			big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    GET_DOUBLE(arg2, f2);
-
-		do_float:
-		    f1.fd = f1.fd / f2.fd;
-		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-			erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live);
-		    }
-		    hp = p->htop;
-		    p->htop += FLOAT_SIZE_OBJECT;
-		    PUT_DOUBLE(f1, hp);
-		    return make_float(hp);
-		default:
-		    goto badarith;
-		}
-	    default:
-		goto badarith;
-	    }
-	}
-    default:
-	goto badarith;
-    }
-}
-
-Eterm
-erts_gc_int_div(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    int ires;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    switch (NUMBER_CODE(arg1, arg2)) {
-    case SMALL_SMALL:
-	/* This case occurs if the most negative fixnum is divided by -1. */
-	ASSERT(arg2 == make_small(-1));
-	arg1 = small_to_big(signed_val(arg1), tmp_big1);
-	/*FALLTHROUGH*/
-    case BIG_SMALL:
-	arg2 = small_to_big(signed_val(arg2), tmp_big2);
-	goto L_big_div;
-    case SMALL_BIG:
-	if (arg1 != make_small(MIN_SMALL)) {
-	    return SMALL_ZERO;
-	}
-	arg1 = small_to_big(signed_val(arg1), tmp_big1);
-	/*FALLTHROUGH*/
-    case BIG_BIG:
-    L_big_div:
-	ires = big_ucomp(arg1, arg2);
-	if (ires < 0) {
-	    arg1 = SMALL_ZERO;
-	} else if (ires == 0) {
-	    arg1 = (big_sign(arg1) == big_sign(arg2)) ?
-		SMALL_ONE : SMALL_MINUS_ONE;
-	} else {
-	    Eterm* hp;
-	    int i = big_size(arg1);
-	    Uint need;
-
-	    ires = big_size(arg2);
-	    need = BIG_NEED_SIZE(i-ires+1) + BIG_NEED_SIZE(i);
-	    if (ERTS_NEED_GC(p, need)) {
-		erts_garbage_collect(p, need, reg, live+2);
-		if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-		    arg1 = reg[live];
-		}
-		if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-		    arg2 = reg[live+1];
-		}
-	    }
-	    hp = p->htop;
-	    p->htop += need;
-	    arg1 = big_div(arg1, arg2, hp);
-	    trim_heap(p, hp, arg1);
-	    if (is_nil(arg1)) {
-		p->freason = SYSTEM_LIMIT;
-		return THE_NON_VALUE;
-	    }
-	}
-	return arg1;
-    default:
-	p->freason = BADARITH;
-	return THE_NON_VALUE;
-    }
-}
-
-Eterm
-erts_gc_int_rem(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    int ires;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    switch (NUMBER_CODE(arg1, arg2)) {
-    case BIG_SMALL:
-	arg2 = small_to_big(signed_val(arg2), tmp_big2);
-	goto L_big_rem;
-    case SMALL_BIG:
-	if (arg1 != make_small(MIN_SMALL)) {
-	    return arg1;
-	} else {
-	    Eterm tmp;
-	    tmp = small_to_big(signed_val(arg1), tmp_big1);
-	    if ((ires = big_ucomp(tmp, arg2)) == 0) {
-		return SMALL_ZERO;
-	    } else {
-		ASSERT(ires < 0);
-		return arg1;
-	    }
-	}
-	/* All paths returned */
-    case BIG_BIG:
-    L_big_rem:
-	ires = big_ucomp(arg1, arg2);
-	if (ires == 0) {
-	    arg1 = SMALL_ZERO;
-	} else if (ires > 0) {
-	    Eterm* hp;
-	    Uint need = BIG_NEED_SIZE(big_size(arg1));
-
-	    if (ERTS_NEED_GC(p, need)) {
-		erts_garbage_collect(p, need, reg, live+2);
-		if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-		    arg1 = reg[live];
-		}
-		if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-		    arg2 = reg[live+1];
-		}
-	    }
-	    hp = p->htop;
-	    p->htop += need;
-	    arg1 = big_rem(arg1, arg2, hp);
-	    trim_heap(p, hp, arg1);
-	    if (is_nil(arg1)) {
-		p->freason = SYSTEM_LIMIT;
-		return THE_NON_VALUE;
-	    }
-	}
-	return arg1;
-    default:
-	p->freason = BADARITH;
-	return THE_NON_VALUE;
-    }
-}
-
-#define DEFINE_GC_LOGIC_FUNC(func)						\
-Eterm erts_gc_##func(Process* p, Eterm* reg, Uint live)				\
-{										\
-    Eterm arg1;									\
-    Eterm arg2;									\
-    DECLARE_TMP(tmp_big1,0,p);							\
-    DECLARE_TMP(tmp_big2,1,p);							\
-    Eterm* hp;									\
-    int need;									\
-										\
-    arg1 = reg[live];								\
-    arg2 = reg[live+1];								\
-    switch (NUMBER_CODE(arg1, arg2)) {						\
-    case SMALL_BIG:								\
-	arg1 = small_to_big(signed_val(arg1), tmp_big1);			\
-	need = BIG_NEED_SIZE(big_size(arg2) + 1);				\
-	if (ERTS_NEED_GC(p, need)) {						\
-	    erts_garbage_collect(p, need, reg, live+2);				\
-	    arg2 = reg[live+1];							\
-	}									\
-	break;									\
-    case BIG_SMALL:								\
-	arg2 = small_to_big(signed_val(arg2), tmp_big2);			\
-	need = BIG_NEED_SIZE(big_size(arg1) + 1);				\
-	if (ERTS_NEED_GC(p, need)) {						\
-	    erts_garbage_collect(p, need, reg, live+2);				\
-	    arg1 = reg[live];							\
-	}									\
-	break;									\
-    case BIG_BIG:								\
-	need = BIG_NEED_SIZE(MAX(big_size(arg1), big_size(arg2)) + 1);		\
-	if (ERTS_NEED_GC(p, need)) {						\
-	    erts_garbage_collect(p, need, reg, live+2);				\
-	    arg1 = reg[live];							\
-	    arg2 = reg[live+1];							\
-	}									\
-	break;									\
-    default:									\
-	p->freason = BADARITH;							\
-	return THE_NON_VALUE;							\
-    }										\
-    hp = p->htop;								\
-    p->htop += need;								\
-    arg1 = big_##func(arg1, arg2, hp);						\
-    trim_heap(p, hp, arg1);							\
-    return arg1;								\
-}
-
-DEFINE_GC_LOGIC_FUNC(band)
-DEFINE_GC_LOGIC_FUNC(bor)
-DEFINE_GC_LOGIC_FUNC(bxor)
-
-Eterm erts_gc_bnot(Process* p, Eterm* reg, Uint live)
-{
-    Eterm result;
-    Eterm arg;
-    Uint need;
-    Eterm* bigp;
-
-    arg = reg[live];
-    if (is_not_big(arg)) {
-	p->freason = BADARITH;
-	return NIL;
-    } else {
-	need = BIG_NEED_SIZE(big_size(arg)+1);
-	if (ERTS_NEED_GC(p, need)) {
-	    erts_garbage_collect(p, need, reg, live+1);
-	    arg = reg[live];
-	}
-	bigp = p->htop;
-	p->htop += need;
-	result = big_bnot(arg, bigp);
-	trim_heap(p, bigp, result);
-	if (is_nil(result)) {
-	    p->freason = SYSTEM_LIMIT;
-	    return NIL;
-	}
-    }
-    return result;
-} 
-
 /* Needed to remove compiler optimization */
 double erts_get_positive_zero_float() {
     return 0.0f;
diff --git a/erts/emulator/beam/erl_bestfit_alloc.c b/erts/emulator/beam/erl_bestfit_alloc.c
index 9cb1199c2a..0e7be99801 100644
--- a/erts/emulator/beam/erl_bestfit_alloc.c
+++ b/erts/emulator/beam/erl_bestfit_alloc.c
@@ -122,8 +122,8 @@ typedef struct {
     RBTree_t *next;
 } RBTreeList_t;
 
-#define LIST_NEXT(N) (((RBTreeList_t *) (N))->next)
-#define LIST_PREV(N) (((RBTreeList_t *) (N))->t.parent)
+#define BF_LIST_NEXT(N) (((RBTreeList_t *) (N))->next)
+#define BF_LIST_PREV(N) (((RBTreeList_t *) (N))->t.parent)
 
 
 #ifdef DEBUG
@@ -209,6 +209,8 @@ erts_bfalc_start(BFAllctr_t *bfallctr,
     allctr->add_mbc                     = NULL;
     allctr->remove_mbc		        = NULL;
     allctr->largest_fblk_in_mbc         = NULL;
+    allctr->first_fblk_in_mbc           = NULL;
+    allctr->next_fblk_in_mbc            = NULL;
     allctr->init_atoms			= init_atoms;
 
 #ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
@@ -593,7 +595,6 @@ aobf_link_free_block(Allctr_t *allctr, Block_t *block)
     RBTree_t *blk = (RBTree_t *) block;
     Uint blk_sz = BF_BLK_SZ(blk);
 
-    
 
     blk->flags	= 0;
     blk->left	= NULL;
@@ -673,7 +674,7 @@ aobf_get_free_block(Allctr_t *allctr, Uint size,
 	    x = x->left;
 	}
     }
-    
+
     if (!blk)
 	return NULL;
 
@@ -729,11 +730,11 @@ bf_link_free_block(Allctr_t *allctr, Block_t *block)
 	    if (blk_sz == size) {
 
 		SET_LIST_ELEM(blk);
-		LIST_NEXT(blk) = LIST_NEXT(x);
-		LIST_PREV(blk) = x;
-		if (LIST_NEXT(x))
-		    LIST_PREV(LIST_NEXT(x)) = blk;
-		LIST_NEXT(x) = blk;
+		BF_LIST_NEXT(blk) = BF_LIST_NEXT(x);
+		BF_LIST_PREV(blk) = x;
+		if (BF_LIST_NEXT(x))
+		    BF_LIST_PREV(BF_LIST_NEXT(x)) = blk;
+		BF_LIST_NEXT(x) = blk;
 
 		return; /* Finnished */
 	    }
@@ -764,7 +765,7 @@ bf_link_free_block(Allctr_t *allctr, Block_t *block)
     }
 
     SET_TREE_NODE(blk);
-    LIST_NEXT(blk) = NULL;
+    BF_LIST_NEXT(blk) = NULL;
 
 #ifdef HARD_DEBUG
     check_tree(root, 0, 0);
@@ -780,22 +781,22 @@ bf_unlink_free_block(Allctr_t *allctr, Block_t *block)
 
     if (IS_LIST_ELEM(x)) {
 	/* Remove from list */
-	ASSERT(LIST_PREV(x));
-	LIST_NEXT(LIST_PREV(x)) = LIST_NEXT(x);
-	if (LIST_NEXT(x))
-	    LIST_PREV(LIST_NEXT(x)) = LIST_PREV(x);
+	ASSERT(BF_LIST_PREV(x));
+	BF_LIST_NEXT(BF_LIST_PREV(x)) = BF_LIST_NEXT(x);
+	if (BF_LIST_NEXT(x))
+	    BF_LIST_PREV(BF_LIST_NEXT(x)) = BF_LIST_PREV(x);
     }
-    else if (LIST_NEXT(x)) {
+    else if (BF_LIST_NEXT(x)) {
 	/* Replace tree node by next element in list... */
 
-	ASSERT(BF_BLK_SZ(LIST_NEXT(x)) == BF_BLK_SZ(x));
+	ASSERT(BF_BLK_SZ(BF_LIST_NEXT(x)) == BF_BLK_SZ(x));
 	ASSERT(IS_TREE_NODE(x));
-	ASSERT(IS_LIST_ELEM(LIST_NEXT(x)));
+	ASSERT(IS_LIST_ELEM(BF_LIST_NEXT(x)));
 
 #ifdef HARD_DEBUG
 	check_tree(root, 0, 0);
 #endif
-	replace(root, x, LIST_NEXT(x));
+	replace(root, x, BF_LIST_NEXT(x));
 
 #ifdef HARD_DEBUG
 	check_tree(bfallctr, 0);
@@ -834,7 +835,7 @@ bf_get_free_block(Allctr_t *allctr, Uint size,
 	    x = x->left;
 	}
     }
-    
+
     if (!blk)
 	return NULL;
 
@@ -853,7 +854,7 @@ bf_get_free_block(Allctr_t *allctr, Uint size,
 
     /* Use next block if it exist in order to avoid replacing
        the tree node */
-    blk = LIST_NEXT(blk) ? LIST_NEXT(blk) : blk;
+    blk = BF_LIST_NEXT(blk) ? BF_LIST_NEXT(blk) : blk;
 
     bf_unlink_free_block(allctr, (Block_t *) blk);
     return (Block_t *) blk;
@@ -938,7 +939,7 @@ info_options(Allctr_t *allctr,
     }
 
     if (hpp || szp) {
-	
+
 	if (!atoms_initialized)
 	    erts_exit(ERTS_ERROR_EXIT, "%s:%d: Internal error: Atoms not initialized",
 		     __FILE__, __LINE__);;
@@ -969,12 +970,12 @@ erts_bfalc_test(UWord op, UWord a1, UWord a2)
     case 0x202:	return (UWord) ((RBTree_t *) a1)->parent;
     case 0x203:	return (UWord) ((RBTree_t *) a1)->left;
     case 0x204:	return (UWord) ((RBTree_t *) a1)->right;
-    case 0x205:	return (UWord) LIST_NEXT(a1);
+    case 0x205:	return (UWord) BF_LIST_NEXT(a1);
     case 0x206:	return (UWord) IS_BLACK((RBTree_t *) a1);
     case 0x207:	return (UWord) IS_TREE_NODE((RBTree_t *) a1);
     case 0x208:	return (UWord) 1; /* IS_BF_ALGO */
     case 0x20a: return (UWord) !((BFAllctr_t *) a1)->address_order; /* IS_BF */
-    case 0x20b:	return (UWord) LIST_PREV(a1);
+    case 0x20b:	return (UWord) BF_LIST_PREV(a1);
     default:	ASSERT(0); return ~((UWord) 0);
     }
 }
diff --git a/erts/emulator/beam/erl_bif_atomics.c b/erts/emulator/beam/erl_bif_atomics.c
index 092dbb3bd3..029831bd95 100644
--- a/erts/emulator/beam/erl_bif_atomics.c
+++ b/erts/emulator/beam/erl_bif_atomics.c
@@ -133,7 +133,7 @@ static ERTS_INLINE Eterm bld_atomic(Process* proc, AtomicsRef* p,
         if ((Uint64)val <= MAX_SMALL)
             return make_small((Sint) val);
         else {
-            Uint hsz = ERTS_UINT64_HEAP_SIZE(val);
+            Uint hsz = ERTS_UINT64_HEAP_SIZE((Uint64)val);
             Eterm* hp = HAlloc(proc, hsz);
             return erts_uint64_to_big(val, &hp);
         }
diff --git a/erts/emulator/beam/erl_bif_binary.c b/erts/emulator/beam/erl_bif_binary.c
index a2610bf2e1..b8e56390c1 100644
--- a/erts/emulator/beam/erl_bif_binary.c
+++ b/erts/emulator/beam/erl_bif_binary.c
@@ -208,8 +208,8 @@ typedef struct _ac_trie {
 typedef struct _bm_data {
     byte *x;
     Sint len;
+    Sint *badshift;
     Sint *goodshift;
-    Sint badshift[ALPHABET_SIZE];
 } BMData;
 
 typedef struct _ac_find_all_state {
@@ -319,16 +319,104 @@ static void dump_ac_node(ACNode *node, int indent, int ch);
  * The needed size of binary data for a search structure - given the
  * accumulated string lengths.
  */
-#define BM_SIZE(StrLen) 	      /* StrLen: length of searchstring */ \
-((MYALIGN(sizeof(Sint) * (StrLen))) + /* goodshift array */                \
- MYALIGN(StrLen) +                    /* searchstring saved */             \
- (MYALIGN(sizeof(BMData))))           /* Structure */
+#define BM_SIZE_SINGLE()    /* Single byte search string */ \
+(MYALIGN(1) +               /* searchstring saved */        \
+ (MYALIGN(sizeof(BMData)))) /* Structure */
+
+#define BM_SIZE_MULTI(StrLen) 	           /* StrLen: length of searchstring */ \
+((MYALIGN(sizeof(Uint) * (StrLen))) +      /* goodshift array */                \
+ (MYALIGN(sizeof(Uint) * ALPHABET_SIZE)) + /* badshift array */                 \
+ MYALIGN(StrLen) +                         /* searchstring saved */             \
+ (MYALIGN(sizeof(BMData))))                /* Structure */
 
 #define AC_SIZE(StrLens)       /* StrLens: sum of all searchstring lengths */ \
 ((MYALIGN(sizeof(ACNode)) *                                                   \
 ((StrLens)+1)) + 	       /* The actual nodes (including rootnode) */    \
  MYALIGN(sizeof(ACTrie)))      /* Structure */
 
+/*
+ * Boyer Moore - most obviously implemented more or less exactly as
+ * Christian Charras and Thierry Lecroq describe it in "Handbook of
+ * Exact String-Matching Algorithms"
+ * http://www-igm.univ-mlv.fr/~lecroq/string/
+ */
+
+/*
+ * Call this to compute badshifts array
+ */
+static void compute_badshifts(BMData *bmd)
+{
+    Sint i;
+    Sint m = bmd->len;
+
+    for (i = 0; i < ALPHABET_SIZE; ++i) {
+	bmd->badshift[i] = m;
+    }
+    for (i = 0; i < m - 1; ++i) {
+	bmd->badshift[bmd->x[i]] = m - i - 1;
+    }
+}
+
+/* Helper for "compute_goodshifts" */
+static void compute_suffixes(byte *x, Sint m, Sint *suffixes)
+{
+    int f,g,i;
+
+    suffixes[m - 1] = m;
+
+    f = 0; /* To avoid use before set warning */
+
+    g = m - 1;
+
+    for (i = m - 2; i >= 0; --i) {
+	if (i > g && suffixes[i + m - 1 - f] < i - g) {
+	    suffixes[i] = suffixes[i + m - 1 - f];
+	} else {
+	    if (i < g) {
+		g = i;
+	    }
+	    f = i;
+	    while ( g >= 0 && x[g] == x[g + m - 1 - f] ) {
+		--g;
+	    }
+	    suffixes[i] = f - g;
+	}
+    }
+}
+
+/*
+ * Call this to compute goodshift array
+ */
+static void compute_goodshifts(BMData *bmd)
+{
+    Sint m = bmd->len;
+    byte *x = bmd->x;
+    Sint i, j;
+    Sint *suffixes = erts_alloc(ERTS_ALC_T_TMP, m * sizeof(Sint));
+
+    compute_suffixes(x, m, suffixes);
+
+    for (i = 0; i < m; ++i) {
+	bmd->goodshift[i] = m;
+    }
+
+    j = 0;
+
+    for (i = m - 1; i >= -1; --i) {
+	if (i == -1 || suffixes[i] == i + 1) {
+	    while (j < m - 1 - i) {
+		if (bmd->goodshift[j] == m) {
+		    bmd->goodshift[j] = m - 1 - i;
+		}
+		++j;
+	    }
+	}
+    }
+    for (i = 0; i <= m - 2; ++i) {
+	bmd->goodshift[m - 1 - suffixes[i]] = m - 1 - i;
+    }
+    erts_free(ERTS_ALC_T_TMP, suffixes);
+}
 
 /*
  * Callback for the magic binary
@@ -377,20 +465,37 @@ static ACTrie *create_acdata(MyAllocator *my, Uint len,
 
 /*
  * The same initialization of allocator and basic data for Boyer-Moore.
+ * For single byte, we don't use goodshift and badshift, only memchr.
  */
 static BMData *create_bmdata(MyAllocator *my, byte *x, Uint len,
 			     Binary **the_bin /* out */)
 {
-    Uint datasize = BM_SIZE(len);
+    Uint datasize;
     BMData *bmd;
-    Binary *mb = erts_create_magic_binary(datasize,cleanup_my_data_bm);
-    byte *data = ERTS_MAGIC_BIN_DATA(mb);
+    Binary *mb;
+    byte *data;
+
+    if(len > 1) {
+	datasize = BM_SIZE_MULTI(len);
+    } else {
+	datasize = BM_SIZE_SINGLE();
+    }
+
+    mb = erts_create_magic_binary(datasize,cleanup_my_data_bm);
+    data = ERTS_MAGIC_BIN_DATA(mb);
     init_my_allocator(my, datasize, data);
     bmd = my_alloc(my, sizeof(BMData));
     bmd->x = my_alloc(my,len);
     sys_memcpy(bmd->x,x,len);
     bmd->len = len;
-    bmd->goodshift = my_alloc(my,sizeof(Uint) * len);
+
+    if(len > 1) {
+	bmd->goodshift = my_alloc(my, sizeof(Uint) * len);
+	bmd->badshift = my_alloc(my, sizeof(Uint) * ALPHABET_SIZE);
+	compute_badshifts(bmd);
+	compute_goodshifts(bmd);
+    }
+
     *the_bin = mb;
     return bmd;
 }
@@ -711,91 +816,8 @@ static BFReturn ac_find_all_non_overlapping(BinaryFindContext *ctx, byte *haysta
     return (m == 0) ? BF_NOT_FOUND : BF_OK;
 }
 
-/*
- * Boyer Moore - most obviously implemented more or less exactly as
- * Christian Charras and Thierry Lecroq describe it in "Handbook of
- * Exact String-Matching Algorithms"
- * http://www-igm.univ-mlv.fr/~lecroq/string/
- */
-
-/*
- * Call this to compute badshifts array
- */
-static void compute_badshifts(BMData *bmd)
-{
-    Sint i;
-    Sint m = bmd->len;
-
-    for (i = 0; i < ALPHABET_SIZE; ++i) {
-	bmd->badshift[i] = m;
-    }
-    for (i = 0; i < m - 1; ++i) {
-	bmd->badshift[bmd->x[i]] = m - i - 1;
-    }
-}
-
-/* Helper for "compute_goodshifts" */
-static void compute_suffixes(byte *x, Sint m, Sint *suffixes)
-{
-    int f,g,i;
-
-    suffixes[m - 1] = m;
-
-    f = 0; /* To avoid use before set warning */
-
-    g = m - 1;
-
-    for (i = m - 2; i >= 0; --i) {
-	if (i > g && suffixes[i + m - 1 - f] < i - g) {
-	    suffixes[i] = suffixes[i + m - 1 - f];
-	} else {
-	    if (i < g) {
-		g = i;
-	    }
-	    f = i;
-	    while ( g >= 0 && x[g] == x[g + m - 1 - f] ) {
-		--g;
-	    }
-	    suffixes[i] = f - g;
-	}
-    }
-}
-
-/*
- * Call this to compute goodshift array
- */
-static void compute_goodshifts(BMData *bmd)
-{
-    Sint m = bmd->len;
-    byte *x = bmd->x;
-    Sint i, j;
-    Sint *suffixes = erts_alloc(ERTS_ALC_T_TMP, m * sizeof(Sint));
-
-    compute_suffixes(x, m, suffixes);
-
-    for (i = 0; i < m; ++i) {
-	bmd->goodshift[i] = m;
-    }
-
-    j = 0;
-
-    for (i = m - 1; i >= -1; --i) {
-	if (i == -1 || suffixes[i] == i + 1) {
-	    while (j < m - 1 - i) {
-		if (bmd->goodshift[j] == m) {
-		    bmd->goodshift[j] = m - 1 - i;
-		}
-		++j;
-	    }
-	}
-    }
-    for (i = 0; i <= m - 2; ++i) {
-	bmd->goodshift[m - 1 - suffixes[i]] = m - 1 - i;
-    }
-    erts_free(ERTS_ALC_T_TMP, suffixes);
-}
-
 #define BM_LOOP_FACTOR 10 /* Should we have a higher value? */
+#define MC_LOOP_FACTOR 8
 
 static void bm_init_find_first_match(BinaryFindContext *ctx)
 {
@@ -819,13 +841,38 @@ static BFReturn bm_find_first_match(BinaryFindContext *ctx, byte *haystack)
     Sint i;
     Sint j = state->pos;
     register Uint reds = *reductions;
+    byte *pos_pointer;
+    Sint needle_last = blen - 1;
+    Sint mem_read = len - needle_last - j;
 
-    while (j <= len - blen) {
+    if (mem_read <= 0) {
+	return BF_NOT_FOUND;
+    }
+    mem_read = MIN(mem_read, reds * MC_LOOP_FACTOR);
+    ASSERT(mem_read > 0);
+
+    pos_pointer = memchr(&haystack[j + needle_last], needle[needle_last], mem_read);
+    if (pos_pointer == NULL) {
+	reds -= mem_read / MC_LOOP_FACTOR;
+	j += mem_read;
+    } else {
+	reds -= (pos_pointer - &haystack[j]) / MC_LOOP_FACTOR;
+	j = pos_pointer - haystack - needle_last;
+    }
+
+    // Ensure we have at least one reduction before entering the loop
+    ++reds;
+
+    for(;;) {
+	if (j > len - blen) {
+	    *reductions = reds;
+	    return BF_NOT_FOUND;
+	}
 	if (--reds == 0) {
 	    state->pos = j;
 	    return BF_RESTART;
 	}
-	for (i = blen - 1; i >= 0 && needle[i] == haystack[i + j]; --i)
+	for (i = needle_last; i >= 0 && needle[i] == haystack[i + j]; --i)
 	    ;
 	if (i < 0) { /* found */
 	    *reductions = reds;
@@ -835,8 +882,6 @@ static BFReturn bm_find_first_match(BinaryFindContext *ctx, byte *haystack)
 	}
 	j += MAX(gs[i],bs[haystack[i+j]] - blen + 1 + i);
     }
-    *reductions = reds;
-    return BF_NOT_FOUND;
 }
 
 static void bm_init_find_all(BinaryFindContext *ctx)
@@ -875,14 +920,38 @@ static BFReturn bm_find_all_non_overlapping(BinaryFindContext *ctx, byte *haysta
     Sint *gs = bmd->goodshift;
     Sint *bs = bmd->badshift;
     byte *needle = bmd->x;
-    Sint i;
+    Sint i = -1; /* Use memchr on start and on every match */
     Sint j = state->pos;
     Uint m = state->m;
     Uint allocated = state->allocated;
     FindallData *out = state->out;
     register Uint reds = *reductions;
+    byte *pos_pointer;
+    Sint needle_last = blen - 1;
+    Sint mem_read;
 
-    while (j <= len - blen) {
+    for(;;) {
+	if (i < 0) {
+	    mem_read = len - needle_last - j;
+	    if(mem_read <= 0) {
+		goto done;
+	    }
+	    mem_read = MIN(mem_read, reds * MC_LOOP_FACTOR);
+	    ASSERT(mem_read > 0);
+	    pos_pointer = memchr(&haystack[j + needle_last], needle[needle_last], mem_read);
+	    if (pos_pointer == NULL) {
+		reds -= mem_read / MC_LOOP_FACTOR;
+		j += mem_read;
+	    } else {
+		reds -= (pos_pointer - &haystack[j]) / MC_LOOP_FACTOR;
+		j = pos_pointer - haystack - needle_last;
+	    }
+	    // Ensure we have at least one reduction when resuming the loop
+	    ++reds;
+	}
+	if (j > len - blen) {
+	    goto done;
+	}
 	if (--reds == 0) {
 	    state->pos = j;
 	    state->m = m;
@@ -890,7 +959,7 @@ static BFReturn bm_find_all_non_overlapping(BinaryFindContext *ctx, byte *haysta
 	    state->out = out;
 	    return BF_RESTART;
 	}
-	for (i = blen - 1; i >= 0 && needle[i] == haystack[i + j]; --i)
+	for (i = needle_last; i >= 0 && needle[i] == haystack[i + j]; --i)
 	    ;
 	if (i < 0) { /* found */
 	    if (m >= allocated) {
@@ -912,6 +981,7 @@ static BFReturn bm_find_all_non_overlapping(BinaryFindContext *ctx, byte *haysta
 	    j += MAX(gs[i],bs[haystack[i+j]] - blen + 1 + i);
 	}
     }
+ done:
     state->m = m;
     state->out = out;
     *reductions = reds;
@@ -931,6 +1001,7 @@ static int do_binary_match_compile(Eterm argument, Eterm *tag, Binary **binp)
     Eterm t, b, comp_term = NIL;
     Uint characters;
     Uint words;
+    Uint size;
 
     characters = 0;
     words = 0;
@@ -946,11 +1017,12 @@ static int do_binary_match_compile(Eterm argument, Eterm *tag, Binary **binp)
 	    if (binary_bitsize(b) != 0) {
 		goto badarg;
 	    }
-	    if (binary_size(b) == 0) {
+	    size = binary_size(b);
+	    if (size == 0) {
 		goto badarg;
 	    }
 	    ++words;
-	    characters += binary_size(b);
+	    characters += size;
 	}
 	if (is_not_nil(t)) {
 	    goto badarg;
@@ -979,16 +1051,13 @@ static int do_binary_match_compile(Eterm argument, Eterm *tag, Binary **binp)
 	Uint bitoffs, bitsize;
 	byte *temp_alloc = NULL;
 	MyAllocator my;
-	BMData *bmd;
 	Binary *bin;
 
 	ERTS_GET_BINARY_BYTES(comp_term, bytes, bitoffs, bitsize);
 	if (bitoffs != 0) {
 	    bytes = erts_get_aligned_binary_bytes(comp_term, &temp_alloc);
 	}
-	bmd = create_bmdata(&my, bytes, characters, &bin);
-	compute_badshifts(bmd);
-	compute_goodshifts(bmd);
+        create_bmdata(&my, bytes, characters, &bin);
 	erts_free_aligned_binary_bytes(temp_alloc);
 	CHECK_ALLOCATOR(my);
 	*tag = am_bm;
@@ -1681,9 +1750,8 @@ static Eterm do_split_single_result(Process *p, Eterm subject, BinaryFindContext
     Uint offset;
     Uint bit_offset;
     Uint bit_size;
-    ErlSubBin *sb1;
-    ErlSubBin *sb2;
-    Eterm *hp;
+    Uint hp_need;
+    Eterm *hp, *hp_end;
     Eterm ret;
 
     pos = ff->pos;
@@ -1696,57 +1764,58 @@ static Eterm do_split_single_result(Process *p, Eterm subject, BinaryFindContext
 	if (pos == 0) {
 	    ret = NIL;
 	} else {
-	    hp = HAlloc(p, (ERL_SUB_BIN_SIZE + 2));
+	    Eterm extracted;
+
+	    hp_need = EXTRACT_SUB_BIN_HEAP_NEED + 2;
+
+	    hp = HAlloc(p, hp_need);
+	    hp_end = hp + hp_need;
+
 	    ERTS_GET_REAL_BIN(subject, orig, offset, bit_offset, bit_size);
-	    sb1 = (ErlSubBin *) hp;
-	    sb1->thing_word = HEADER_SUB_BIN;
-	    sb1->size = pos;
-	    sb1->offs = offset;
-	    sb1->orig = orig;
-	    sb1->bitoffs = bit_offset;
-	    sb1->bitsize = bit_size;
-	    sb1->is_writable = 0;
-	    hp += ERL_SUB_BIN_SIZE;
-
-	    ret = CONS(hp, make_binary(sb1), NIL);
+	    extracted = erts_extract_sub_binary(&hp, orig, binary_bytes(orig),
+	                                        offset * 8 + bit_offset,
+	                                        pos * 8 + bit_size);
+
+	    ret = CONS(hp, extracted, NIL);
 	    hp += 2;
+
+	    HRelease(p, hp_end, hp);
+
+	    return ret;
 	}
     } else {
-	if ((ctx->flags & BF_FLAG_SPLIT_TRIM_ALL) && (pos == 0)) {
-	    hp = HAlloc(p, 1 * (ERL_SUB_BIN_SIZE + 2));
-	    ERTS_GET_REAL_BIN(subject, orig, offset, bit_offset, bit_size);
-	    sb1 = NULL;
-	} else {
-	    hp = HAlloc(p, 2 * (ERL_SUB_BIN_SIZE + 2));
-	    ERTS_GET_REAL_BIN(subject, orig, offset, bit_offset, bit_size);
-	    sb1 = (ErlSubBin *) hp;
-	    sb1->thing_word = HEADER_SUB_BIN;
-	    sb1->size = pos;
-	    sb1->offs = offset;
-	    sb1->orig = orig;
-	    sb1->bitoffs = bit_offset;
-	    sb1->bitsize = 0;
-	    sb1->is_writable = 0;
-	    hp += ERL_SUB_BIN_SIZE;
-	}
-
-	sb2 = (ErlSubBin *) hp;
-	sb2->thing_word = HEADER_SUB_BIN;
-	sb2->size = orig_size - pos - len;
-	sb2->offs = offset + pos + len;
-	sb2->orig = orig;
-	sb2->bitoffs = bit_offset;
-	sb2->bitsize = bit_size;
-	sb2->is_writable = 0;
-	hp += ERL_SUB_BIN_SIZE;
-
-	ret = CONS(hp, make_binary(sb2), NIL);
-	hp += 2;
-	if (sb1 != NULL) {
-	    ret = CONS(hp, make_binary(sb1), ret);
-	    hp += 2;
-	}
+        Eterm first, rest;
+
+        hp_need = (EXTRACT_SUB_BIN_HEAP_NEED + 2) * 2;
+
+        hp = HAlloc(p, hp_need);
+        hp_end = hp + hp_need;
+
+        ERTS_GET_REAL_BIN(subject, orig, offset, bit_offset, bit_size);
+
+        if ((ctx->flags & BF_FLAG_SPLIT_TRIM_ALL) && (pos == 0)) {
+            first = NIL;
+        } else {
+            first = erts_extract_sub_binary(&hp, orig, binary_bytes(orig),
+                                            offset * 8 + bit_offset,
+                                            pos * 8);
+        }
+
+        rest = erts_extract_sub_binary(&hp, orig, binary_bytes(orig),
+                                       (offset + pos + len) * 8 + bit_offset,
+                                       (orig_size - pos - len) * 8 + bit_size);
+
+        ret = CONS(hp, rest, NIL);
+        hp += 2;
+
+        if (first != NIL) {
+            ret = CONS(hp, first, ret);
+            hp += 2;
+        }
+
+        HRelease(p, hp_end, hp);
     }
+
     return ret;
 }
 
@@ -1760,7 +1829,9 @@ static Eterm do_split_global_result(Process *p, Eterm subject, BinaryFindContext
     Uint offset;
     Uint bit_offset;
     Uint bit_size;
-    ErlSubBin *sb;
+    Uint extracted_offset;
+    Uint extracted_size;
+    Eterm extracted;
     Uint do_trim;
     Sint i;
     register Uint reds = ctx->reds;
@@ -1783,7 +1854,8 @@ static Eterm do_split_global_result(Process *p, Eterm subject, BinaryFindContext
 	    *ctxp = ctx;
 	    fa = &(ctx->u.fa);
 	}
-	erts_factory_proc_prealloc_init(&(fa->factory), p, (fa->size + 1) * (ERL_SUB_BIN_SIZE + 2));
+	erts_factory_proc_prealloc_init(&(fa->factory), p, (fa->size + 1) *
+	                                (EXTRACT_SUB_BIN_HEAP_NEED + 2));
 	ctx->state = BFResult;
     }
 
@@ -1802,39 +1874,39 @@ static Eterm do_split_global_result(Process *p, Eterm subject, BinaryFindContext
 	    }
 	    return THE_NON_VALUE;
 	}
-	sb = (ErlSubBin *)(fa->factory.hp);
-	sb->size = fa->end_pos - (fad[i].pos + fad[i].len);
-	if (!(sb->size == 0 && do_trim)) {
-	    sb->thing_word = HEADER_SUB_BIN;
-	    sb->offs = offset + fad[i].pos + fad[i].len;
-	    sb->orig = orig;
-	    sb->bitoffs = bit_offset;
-	    sb->bitsize = 0;
-	    sb->is_writable = 0;
-	    fa->factory.hp += ERL_SUB_BIN_SIZE;
-	    fa->term = CONS(fa->factory.hp, make_binary(sb), fa->term);
-	    fa->factory.hp += 2;
-	    do_trim &= ~BF_FLAG_SPLIT_TRIM;
-	}
-	fa->end_pos = fad[i].pos;
+
+        extracted_offset = (offset + fad[i].pos + fad[i].len) * 8 + bit_offset;
+        extracted_size = (fa->end_pos - (fad[i].pos + fad[i].len)) * 8;
+
+        if (!(extracted_size == 0 && do_trim)) {
+            extracted = erts_extract_sub_binary(&fa->factory.hp, orig,
+                                                binary_bytes(orig),
+                                                extracted_offset,
+                                                extracted_size);
+            fa->term = CONS(fa->factory.hp, extracted, fa->term);
+            fa->factory.hp += 2;
+
+            do_trim &= ~BF_FLAG_SPLIT_TRIM;
+        }
+
+        fa->end_pos = fad[i].pos;
     }
 
     fa->head = i;
     ctx->reds = reds;
 
-    sb = (ErlSubBin *)(fa->factory.hp);
-    sb->size = fad[0].pos;
-    if (!(sb->size == 0 && do_trim)) {
-	sb->thing_word = HEADER_SUB_BIN;
-	sb->offs = offset;
-	sb->orig = orig;
-	sb->bitoffs = bit_offset;
-	sb->bitsize = 0;
-	sb->is_writable = 0;
-	fa->factory.hp += ERL_SUB_BIN_SIZE;
-	fa->term = CONS(fa->factory.hp, make_binary(sb), fa->term);
-	fa->factory.hp += 2;
+    extracted_offset = offset * 8 + bit_offset;
+    extracted_size = fad[0].pos * 8;
+
+    if (!(extracted_size == 0 && do_trim)) {
+        extracted = erts_extract_sub_binary(&fa->factory.hp, orig,
+                                            binary_bytes(orig),
+                                            extracted_offset,
+                                            extracted_size);
+        fa->term = CONS(fa->factory.hp, extracted, fa->term);
+        fa->factory.hp += 2;
     }
+
     erts_factory_close(&(fa->factory));
 
     return fa->term;
@@ -1868,8 +1940,8 @@ BIF_RETTYPE erts_binary_part(Process *p, Eterm binary, Eterm epos, Eterm elen)
     Uint offset;
     Uint bit_offset;
     Uint bit_size;
-    Eterm* hp;
-    ErlSubBin* sb;
+    Eterm *hp, *hp_end;
+    Eterm result;
 
     if (is_not_binary(binary)) {
 	goto badarg;
@@ -1901,120 +1973,23 @@ BIF_RETTYPE erts_binary_part(Process *p, Eterm binary, Eterm epos, Eterm elen)
 	goto badarg;
     }
 
-
-
-    hp = HAlloc(p, ERL_SUB_BIN_SIZE);
+    hp = HeapFragOnlyAlloc(p, EXTRACT_SUB_BIN_HEAP_NEED);
+    hp_end = hp + EXTRACT_SUB_BIN_HEAP_NEED;
 
     ERTS_GET_REAL_BIN(binary, orig, offset, bit_offset, bit_size);
-    sb = (ErlSubBin *) hp;
-    sb->thing_word = HEADER_SUB_BIN;
-    sb->size = len;
-    sb->offs = offset + pos;
-    sb->orig = orig;
-    sb->bitoffs = bit_offset;
-    sb->bitsize = 0;
-    sb->is_writable = 0;
-
-    BIF_RET(make_binary(sb));
-
- badarg:
-    BIF_ERROR(p, BADARG);
-}
-
-#define ERTS_NEED_GC(p, need) ((HEAP_LIMIT((p)) - HEAP_TOP((p))) <= (need))
-
-BIF_RETTYPE erts_gc_binary_part(Process *p, Eterm *reg, Eterm live, int range_is_tuple)
-{
-    Uint pos;
-    Sint len;
-    size_t orig_size;
-    Eterm orig;
-    Uint offset;
-    Uint bit_offset;
-    Uint bit_size;
-    Eterm* hp;
-    ErlSubBin* sb;
-    Eterm binary;
-    Eterm *tp;
-    Eterm epos, elen;
-    int extra_args;
-
-
-    if (range_is_tuple) {
-	Eterm tpl = reg[live];
-	extra_args = 1;
-	if (is_not_tuple(tpl)) {
-	    goto badarg;
-	}
-	tp = tuple_val(tpl);
-	if (arityval(*tp) != 2) {
-	    goto badarg;
-	}
-
-	epos = tp[1];
-	elen = tp[2];
-    } else {
-	extra_args = 2;
-	epos = reg[live-1];
-	elen = reg[live];
-    }
-    binary = reg[live-extra_args];
-
-    if (is_not_binary(binary)) {
-	goto badarg;
-    }
-    if (!term_to_Uint(epos, &pos)) {
-	goto badarg;
-    }
-    if (!term_to_Sint(elen, &len)) {
-	goto badarg;
-    }
-    if (len < 0) {
-	Uint lentmp = -(Uint)len;
-	/* overflow */
-	if ((Sint)lentmp < 0) {
-	    goto badarg;
-	}
-	len = lentmp;
-	if (len > pos) {
-	    goto badarg;
-	}
-	pos -= len;
-    }
-    /* overflow */
-    if ((pos + len) < pos || (len > 0 && (pos + len) == pos)) {
-	goto badarg;
-    }
-    if ((orig_size = binary_size(binary)) < pos ||
-	orig_size < (pos + len)) {
-	goto badarg;
-    }
-
-    if (ERTS_NEED_GC(p, ERL_SUB_BIN_SIZE)) {
-	erts_garbage_collect(p, ERL_SUB_BIN_SIZE, reg, live+1-extra_args); /* I don't need the tuple
-									      or indices any more */
-	binary = reg[live-extra_args];
-    }
 
-    hp = p->htop;
-    p->htop += ERL_SUB_BIN_SIZE;
+    result = erts_extract_sub_binary(&hp, orig, binary_bytes(orig),
+                                     (offset + pos) * 8 + bit_offset,
+                                     len * 8);
 
-    ERTS_GET_REAL_BIN(binary, orig, offset, bit_offset, bit_size);
-
-    sb = (ErlSubBin *) hp;
-    sb->thing_word = HEADER_SUB_BIN;
-    sb->size = len;
-    sb->offs = offset + pos;
-    sb->orig = orig;
-    sb->bitoffs = bit_offset;
-    sb->bitsize = 0;
-    sb->is_writable = 0;
+    HRelease(p, hp_end, hp);
 
-    BIF_RET(make_binary(sb));
+    BIF_RET(result);
 
  badarg:
     BIF_ERROR(p, BADARG);
 }
+
 /*************************************************************
  * The actual guard BIFs are in erl_bif_guard.c
  * but the implementation of both the non-gc and the gc
@@ -2762,7 +2737,7 @@ static BIF_RETTYPE do_encode_unsigned(Process *p, Eterm uns, Eterm endianess)
 	dsize_t num_parts = BIG_SIZE(bigp);
 	Eterm res;
 	byte *b;
-	ErtsDigit d;
+	ErtsDigit d = 0;
 
 	if(BIG_SIGN(bigp)) {
 	    goto badarg;
@@ -2778,26 +2753,22 @@ static BIF_RETTYPE do_encode_unsigned(Process *p, Eterm uns, Eterm endianess)
 	if (endianess == am_big) {
 	    Sint i,j;
 	    j = 0;
-	    d = BIG_DIGIT(bigp,0);
 	    for (i=n-1;i>=0;--i) {
-		b[i] = d & 0xFF;
-		if (!((++j) % sizeof(ErtsDigit))) {
+                if (!((j++) % sizeof(ErtsDigit))) {
 		    d = BIG_DIGIT(bigp,j / sizeof(ErtsDigit));
-		} else {
-		    d >>= 8;
 		}
+                b[i] = d & 0xFF;
+                d >>= 8;
 	    }
 	} else {
 	    Sint i,j;
 	    j = 0;
-	    d = BIG_DIGIT(bigp,0);
 	    for (i=0;i<n;++i) {
-		b[i] = d & 0xFF;
-		if (!((++j) % sizeof(ErtsDigit))) {
+                if (!((j++) % sizeof(ErtsDigit))) {
 		    d = BIG_DIGIT(bigp,j / sizeof(ErtsDigit));
-		} else {
-		    d >>= 8;
 		}
+                b[i] = d & 0xFF;
+                d >>= 8;
 	    }
 
 	}
@@ -3012,17 +2983,19 @@ static void dump_bm_data(BMData *bm)
 	}
     }
     erts_printf(">>\n");
-    erts_printf("GoodShift array:\n");
-    for (i = 0; i < bm->len; ++i) {
-	erts_printf("GoodShift[%d]: %ld\n", i, bm->goodshift[i]);
-    }
-    erts_printf("BadShift array:\n");
-    j = 0;
-    for (i = 0; i < ALPHABET_SIZE; i += j) {
-	for (j = 0; i + j < ALPHABET_SIZE && j < 6; ++j) {
-	    erts_printf("BS[%03d]:%02ld, ", i+j, bm->badshift[i+j]);
+    if(bm->len > 1) {
+	erts_printf("GoodShift array:\n");
+	for (i = 0; i < bm->len; ++i) {
+	    erts_printf("GoodShift[%d]: %ld\n", i, bm->goodshift[i]);
+	}
+	erts_printf("BadShift array:\n");
+	j = 0;
+	for (i = 0; i < ALPHABET_SIZE; i += j) {
+	    for (j = 0; i + j < ALPHABET_SIZE && j < 6; ++j) {
+		erts_printf("BS[%03d]:%02ld, ", i+j, bm->badshift[i+j]);
+	    }
+	    erts_printf("\n");
 	}
-	erts_printf("\n");
     }
 }
 
diff --git a/erts/emulator/beam/erl_bif_ddll.c b/erts/emulator/beam/erl_bif_ddll.c
index 4cda0948a0..639aee29dc 100644
--- a/erts/emulator/beam/erl_bif_ddll.c
+++ b/erts/emulator/beam/erl_bif_ddll.c
@@ -829,7 +829,7 @@ BIF_RETTYPE erl_ddll_format_error_int_1(BIF_ALIST_1)
 	    "cannot be loaded/unloaded";
 	break;
     case am_permanent:
-	errstring = "DDLL driver is permanent an can not be unloaded/loaded";
+	errstring = "DDLL driver is permanent an cannot be unloaded/loaded";
 	break;
     case am_not_loaded:
 	errstring = "DDLL driver is not loaded";
diff --git a/erts/emulator/beam/erl_bif_guard.c b/erts/emulator/beam/erl_bif_guard.c
index 8a5c6ada6c..09757e473b 100644
--- a/erts/emulator/beam/erl_bif_guard.c
+++ b/erts/emulator/beam/erl_bif_guard.c
@@ -19,7 +19,12 @@
  */
 
 /*
- * Numeric guard BIFs.
+ * This file implements the former GC BIFs. They used to do a GC when
+ * they needed heap space. Because of changes to the implementation of
+ * literals, those BIFs are now allowed to allocate heap fragments
+ * (using HeapFragOnlyAlloc()). Note that they must NOT call HAlloc(),
+ * because the caller does not do any SWAPIN / SWAPOUT (that is,
+ * HEAP_TOP(p) and HEAP_LIMIT(p) contain stale values).
  */
 
 #ifdef HAVE_CONFIG_H
@@ -36,14 +41,16 @@
 #include "erl_binary.h"
 #include "erl_map.h"
 
-static Eterm gc_double_to_integer(Process* p, double x, Eterm* reg, Uint live);
-
 static Eterm double_to_integer(Process* p, double x);
+static BIF_RETTYPE erlang_length_trap(BIF_ALIST_3);
+static Export erlang_length_export;
 
-/*
- * Guard BIFs called using apply/3 and guard BIFs that never build
- * anything on the heap.
- */
+void erts_init_bif_guard(void)
+{
+    erts_init_trap_export(&erlang_length_export,
+			  am_erlang, am_length, 3,
+			  &erlang_length_trap);
+}
 
 BIF_RETTYPE abs_1(BIF_ALIST_1)
 {
@@ -56,7 +63,7 @@ BIF_RETTYPE abs_1(BIF_ALIST_1)
 	i0 = signed_val(BIF_ARG_1);
 	i = ERTS_SMALL_ABS(i0);
 	if (i0 == MIN_SMALL) {
-	    hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
+	    hp = HeapFragOnlyAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
 	    BIF_RET(uint_to_big(i, hp));
 	} else {
 	    BIF_RET(make_small(i));
@@ -68,7 +75,7 @@ BIF_RETTYPE abs_1(BIF_ALIST_1)
 	    int sz = big_arity(BIF_ARG_1) + 1;
 	    Uint* x;
 
-	    hp = HAlloc(BIF_P, sz);	/* See note at beginning of file */
+	    hp = HeapFragOnlyAlloc(BIF_P, sz);	/* See note at beginning of file */
 	    sz--;
 	    res = make_big(hp);
 	    x = big_val(BIF_ARG_1);
@@ -83,7 +90,7 @@ BIF_RETTYPE abs_1(BIF_ALIST_1)
 
 	GET_DOUBLE(BIF_ARG_1, f);
 	if (f.fd < 0.0) {
-	    hp = HAlloc(BIF_P, FLOAT_SIZE_OBJECT);
+	    hp = HeapFragOnlyAlloc(BIF_P, FLOAT_SIZE_OBJECT);
 	    f.fd = fabs(f.fd);
 	    res = make_float(hp);
 	    PUT_DOUBLE(f, hp);
@@ -116,7 +123,7 @@ BIF_RETTYPE float_1(BIF_ALIST_1)
     } else if (big_to_double(BIF_ARG_1, &f.fd) < 0) {
 	goto badarg;
     }
-    hp = HAlloc(BIF_P, FLOAT_SIZE_OBJECT);
+    hp = HeapFragOnlyAlloc(BIF_P, FLOAT_SIZE_OBJECT);
     res = make_float(hp);
     PUT_DOUBLE(f, hp);
     BIF_RET(res);
@@ -194,26 +201,113 @@ BIF_RETTYPE round_1(BIF_ALIST_1)
     BIF_RET(res);
 }
 
+/*
+ * This version of length/1 is called from native code and apply/3.
+ */
+
 BIF_RETTYPE length_1(BIF_ALIST_1)
 {
+    Eterm args[3];
+
+    /*
+     * Arrange argument registers the way expected by
+     * erts_trapping_length_1(). We save the original argument in
+     * args[2] in case an error should signaled.
+     */
+
+    args[0] = BIF_ARG_1;
+    args[1] = make_small(0);
+    args[2] = BIF_ARG_1;
+    return erlang_length_trap(BIF_P, args, A__I);
+}
+
+static BIF_RETTYPE erlang_length_trap(BIF_ALIST_3)
+{
+    Eterm res;
+
+    res = erts_trapping_length_1(BIF_P, BIF__ARGS);
+    if (is_value(res)) {        /* Success. */
+        BIF_RET(res);
+    } else {                    /* Trap or error. */
+        if (BIF_P->freason == TRAP) {
+            /*
+             * The available reductions were exceeded. Trap.
+             */
+            BIF_TRAP3(&erlang_length_export, BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3);
+        } else {
+            /*
+             * Signal an error. The original argument was tucked away in BIF_ARG_3.
+             */
+            ERTS_BIF_ERROR_TRAPPED1(BIF_P, BIF_P->freason,
+                                    bif_export[BIF_length_1], BIF_ARG_3);
+        }
+    }
+}
+
+/*
+ * Trappable helper function for calculating length/1.
+ *
+ * When calling this function, entries in args[] should be set up as
+ * follows:
+ *
+ *   args[0] = List to calculate length for.
+ *   args[1] = Length accumulator (tagged integer).
+ *
+ * If the return value is a tagged integer, the length was calculated
+ * successfully.
+ *
+ * Otherwise, if return value is THE_NON_VALUE and p->freason is TRAP,
+ * the available reductions were exceeded and this function must be called
+ * again after rescheduling. args[0] and args[1] have been updated to
+ * contain the next part of the list and length so far, respectively.
+ *
+ * Otherwise, if return value is THE_NON_VALUE, the list did not end
+ * in an empty list (and p->freason is BADARG).
+ */
+
+Eterm erts_trapping_length_1(Process* p, Eterm* args)
+{
     Eterm list;
     Uint i;
-     
-    if (is_nil(BIF_ARG_1)) 
-	BIF_RET(SMALL_ZERO);
-    if (is_not_list(BIF_ARG_1)) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
-    list = BIF_ARG_1;
-    i = 0;
-    while (is_list(list)) {
-	i++;
+    Uint max_iter;
+    Uint saved_max_iter;
+
+#if defined(DEBUG) || defined(VALGRIND)
+    max_iter = 50;
+#else
+    max_iter = ERTS_BIF_REDS_LEFT(p) * 16;
+#endif
+    saved_max_iter = max_iter;
+    ASSERT(max_iter > 0);
+
+    list = args[0];
+    i = unsigned_val(args[1]);
+    while (is_list(list) && max_iter != 0) {
 	list = CDR(list_val(list));
+	i++, max_iter--;
+    }
+
+    if (is_list(list)) {
+        /*
+         * We have exceeded the alloted number of iterations.
+         * Save the result so far and signal a trap.
+         */
+        args[0] = list;
+        args[1] = make_small(i);
+        p->freason = TRAP;
+        BUMP_ALL_REDS(p);
+        return THE_NON_VALUE;
+    } else if (is_not_nil(list))  {
+        /* Error. Should be NIL. */
+	BIF_ERROR(p, BADARG);
     }
-    if (is_not_nil(list))  {
-	BIF_ERROR(BIF_P, BADARG);
-    }
-    BIF_RET(make_small(i));
+
+    /*
+     * We reached the end of the list successfully. Bump reductions
+     * and return result.
+     */
+    BUMP_REDS(p, (saved_max_iter - max_iter) / 16);
+    return make_small(i);
 }
 
 /* returns the size of a tuple or a binary */
@@ -229,7 +323,7 @@ BIF_RETTYPE size_1(BIF_ALIST_1)
 	if (IS_USMALL(0, sz)) {
 	    return make_small(sz);
 	} else {
-	    Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
+	    Eterm* hp = HeapFragOnlyAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
 	    BIF_RET(uint_to_big(sz, hp));
 	}
     }
@@ -252,12 +346,12 @@ BIF_RETTYPE bit_size_1(BIF_ALIST_1)
 	    if (IS_USMALL(0,low_bits)) {
 		BIF_RET(make_small(low_bits));
 	    } else {
-		Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
+		Eterm* hp = HeapFragOnlyAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
 		BIF_RET(uint_to_big(low_bits, hp));
 	    }
 	} else {
 	    Uint sz = BIG_UINT_HEAP_SIZE+1;
-	    Eterm* hp = HAlloc(BIF_P, sz);
+	    Eterm* hp = HeapFragOnlyAlloc(BIF_P, sz);
 	    hp[0] = make_pos_bignum_header(sz-1);
 	    BIG_DIGIT(hp,0) = low_bits;
 	    BIG_DIGIT(hp,1) = high_bits;
@@ -281,7 +375,7 @@ BIF_RETTYPE byte_size_1(BIF_ALIST_1)
 	if (IS_USMALL(0, bytesize)) {
 	    BIF_RET(make_small(bytesize));
 	} else {
-	    Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
+	    Eterm* hp = HeapFragOnlyAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
 	    BIF_RET(uint_to_big(bytesize, hp));
 	}
     } else {
@@ -325,7 +419,7 @@ double_to_integer(Process* p, double x)
     }
     sz = BIG_NEED_SIZE(ds);          /* number of words including arity */
 
-    hp = HAlloc(p, sz);
+    hp = HeapFragOnlyAlloc(p, sz);
     res = make_big(hp);
     xp = (ErtsDigit*) (hp + 1);
 
@@ -371,389 +465,3 @@ BIF_RETTYPE binary_part_2(BIF_ALIST_2)
  badarg:
    BIF_ERROR(BIF_P,BADARG);
 }
-
-
-/*
- * The following code is used when a guard that may build on the
- * heap is called directly. They must not use HAlloc(), but must
- * do a garbage collection if there is insufficient heap space.
- *
- * Important note: All error checking MUST be done before doing
- * a garbage collection. The compiler assumes that all registers
- * are still valid if a guard BIF generates an exception.
- */
-
-#define ERTS_NEED_GC(p, need) ((HEAP_LIMIT((p)) - HEAP_TOP((p))) <= (need))
-
-Eterm erts_gc_length_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm list = reg[live];
-    int i;
-
-    if (is_nil(list)) 
-	return SMALL_ZERO;
-    i = 0;
-    while (is_list(list)) {
-	i++;
-	list = CDR(list_val(list));
-    }
-    if (is_not_nil(list))  {
-	BIF_ERROR(p, BADARG);
-    }
-    return make_small(i);
-}
-
-Eterm erts_gc_size_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg = reg[live];
-    if (is_tuple(arg)) {
-	Eterm* tupleptr = tuple_val(arg);
-	return make_small(arityval(*tupleptr));
-    } else if (is_binary(arg)) {
-	Uint sz = binary_size(arg);
-	if (IS_USMALL(0, sz)) {
-	    return make_small(sz);
-	} else {
-	    Eterm* hp;
-	    if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-		erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live);
-	    }
-	    hp = p->htop;
-	    p->htop += BIG_UINT_HEAP_SIZE;
-	    return uint_to_big(sz, hp);
-	}
-    }
-    BIF_ERROR(p, BADARG);
-}
-
-Eterm erts_gc_bit_size_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg = reg[live];
-    if (is_binary(arg)) {
-	Uint low_bits;
-	Uint bytesize;
-	Uint high_bits;
-	bytesize = binary_size(arg);
-	high_bits = bytesize >>  ((sizeof(Uint) * 8)-3);
-	low_bits = (bytesize << 3) + binary_bitsize(arg);
-	if (high_bits == 0) {
-	    if (IS_USMALL(0,low_bits)) {
-		return make_small(low_bits);
-	    } else {
-		Eterm* hp; 
-		if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-		    erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live);
-		}
-		hp = p->htop;
-		p->htop += BIG_UINT_HEAP_SIZE;
-		return uint_to_big(low_bits, hp);
-	    }
-	} else {
-	    Uint sz = BIG_UINT_HEAP_SIZE+1;
-	    Eterm* hp;
-	    if (ERTS_NEED_GC(p, sz)) {
-		erts_garbage_collect(p, sz, reg, live);
-	    }
-	    hp = p->htop;
-	    p->htop += sz;
-	    hp[0] = make_pos_bignum_header(sz-1);
-	    BIG_DIGIT(hp,0) = low_bits;
-	    BIG_DIGIT(hp,1) = high_bits;
-	    return make_big(hp);
-	}
-    } else {
-	BIF_ERROR(p, BADARG);
-    }
-}
-
-Eterm erts_gc_byte_size_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg = reg[live];
-    if (is_binary(arg)) {
-	Uint bytesize = binary_size(arg);
-	if (binary_bitsize(arg) > 0) {
-	    bytesize++;
-	}
-	if (IS_USMALL(0, bytesize)) {
-	    return make_small(bytesize);
-	} else {
-	    Eterm* hp;
-	    if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-		erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live);
-	    }
-	    hp = p->htop;
-	    p->htop += BIG_UINT_HEAP_SIZE;
-	    return uint_to_big(bytesize, hp);
-	}
-    } else {
-	BIF_ERROR(p, BADARG);
-    }
-}
-
-Eterm erts_gc_map_size_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg = reg[live];
-    if (is_flatmap(arg)) {
-	flatmap_t *mp = (flatmap_t*)flatmap_val(arg);
-        return make_small(flatmap_get_size(mp));
-    } else if (is_hashmap(arg)) {
-        Eterm* hp;
-        Uint size;
-	size = hashmap_size(arg);
-        if (IS_USMALL(0, size)) {
-            return make_small(size);
-        }
-        if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-            erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live);
-        }
-        hp = p->htop;
-        p->htop += BIG_UINT_HEAP_SIZE;
-        return uint_to_big(size, hp);
-    }
-    p->fvalue = arg;
-    BIF_ERROR(p, BADMAP);
-}
-
-Eterm erts_gc_abs_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    Eterm res;
-    Sint i0, i;
-    Eterm* hp;
-
-    arg = reg[live];
-
-    /* integer arguments */
-    if (is_small(arg)) {
-	i0 = signed_val(arg);
-	i = ERTS_SMALL_ABS(i0);
-	if (i0 == MIN_SMALL) {
-	    if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-		erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live+1);
-		arg = reg[live];
-	    }
-	    hp = p->htop;
-	    p->htop += BIG_UINT_HEAP_SIZE;
-	    return uint_to_big(i, hp);
-	} else {
-	    return make_small(i);
-	}
-    } else if (is_big(arg)) {
-	if (!big_sign(arg)) {
-	    return arg;
-	} else {
-	    int sz = big_arity(arg) + 1;
-	    Uint* x;
-
-	    if (ERTS_NEED_GC(p, sz)) {
-		erts_garbage_collect(p, sz, reg, live+1);
-		arg = reg[live];
-	    }
-	    hp = p->htop;
-	    p->htop += sz;
-	    sz--;
-	    res = make_big(hp);
-	    x = big_val(arg);
-	    *hp++ = make_pos_bignum_header(sz);
-	    x++;                          /* skip thing */
-	    while(sz--)
-		*hp++ = *x++;
-	    return res;
-	}
-    } else if (is_float(arg)) {
-	FloatDef f;
-
-	GET_DOUBLE(arg, f);
-	if (f.fd < 0.0) {
-	    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-		erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live+1);
-		arg = reg[live];
-	    }
-	    hp = p->htop;
-	    p->htop += FLOAT_SIZE_OBJECT;
-	    f.fd = fabs(f.fd);
-	    res = make_float(hp);
-	    PUT_DOUBLE(f, hp);
-	    return res;
-	}
-	else
-	    return arg;
-    }
-    BIF_ERROR(p, BADARG);
-}
-
-Eterm erts_gc_float_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    Eterm res;
-    Eterm* hp;
-    FloatDef f;
-     
-    /* check args */
-    arg = reg[live];
-    if (is_not_integer(arg)) {
-	if (is_float(arg))  {
-	    return arg;
-	} else {
-	badarg:
-	    BIF_ERROR(p, BADARG);
-	}
-    }
-    if (is_small(arg)) {
-	Sint i = signed_val(arg);
-	f.fd = i;		/* use "C"'s auto casting */
-    } else if (big_to_double(arg, &f.fd) < 0) {
-	goto badarg;
-    }
-    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-	erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live+1);
-	arg = reg[live];
-    }
-    hp = p->htop;
-    p->htop += FLOAT_SIZE_OBJECT;
-    res = make_float(hp);
-    PUT_DOUBLE(f, hp);
-    return res;
-}
-
-Eterm erts_gc_round_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    FloatDef f;
-     
-    arg = reg[live];
-    if (is_not_float(arg)) {
-	if (is_integer(arg))  {
-	    return arg;
-	}
-	BIF_ERROR(p, BADARG);
-    }
-    GET_DOUBLE(arg, f);
-
-    return gc_double_to_integer(p, round(f.fd), reg, live);
-}
-
-Eterm erts_gc_trunc_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    FloatDef f;
-     
-    arg = reg[live];
-    if (is_not_float(arg)) {
-	if (is_integer(arg))  {
-	    return arg;
-	}
-	BIF_ERROR(p, BADARG);
-    }
-    /* get the float */
-    GET_DOUBLE(arg, f);
-
-    /* truncate it and return the resultant integer */
-    return gc_double_to_integer(p, (f.fd >= 0.0) ? floor(f.fd) : ceil(f.fd),
-				reg, live);
-}
-
-Eterm erts_gc_floor_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    FloatDef f;
-
-    arg = reg[live];
-    if (is_not_float(arg)) {
-	if (is_integer(arg))  {
-	    return arg;
-	}
-	BIF_ERROR(p, BADARG);
-    }
-    GET_DOUBLE(arg, f);
-    return gc_double_to_integer(p, floor(f.fd), reg, live);
-}
-
-Eterm erts_gc_ceil_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    FloatDef f;
-
-    arg = reg[live];
-    if (is_not_float(arg)) {
-	if (is_integer(arg))  {
-	    return arg;
-	}
-	BIF_ERROR(p, BADARG);
-    }
-    GET_DOUBLE(arg, f);
-    return gc_double_to_integer(p, ceil(f.fd), reg, live);
-}
-
-static Eterm
-gc_double_to_integer(Process* p, double x, Eterm* reg, Uint live)
-{
-    int is_negative;
-    int ds;
-    ErtsDigit* xp;
-    int i;
-    Eterm res;
-    size_t sz;
-    Eterm* hp;
-    double dbase;
-
-    if ((x < (double) (MAX_SMALL+1)) && (x > (double) (MIN_SMALL-1))) {
-	Sint xi = x;
-	return make_small(xi);
-    }
-
-    if (x >= 0) {
-	is_negative = 0;
-    } else {
-	is_negative = 1;
-	x = -x;
-    }
-
-    /* Unscale & (calculate exponent) */
-    ds = 0;
-    dbase = ((double)(D_MASK)+1);
-    while(x >= 1.0) {
-	x /= dbase;         /* "shift" right */
-	ds++;
-    }
-    sz = BIG_NEED_SIZE(ds);          /* number of words including arity */
-    if (ERTS_NEED_GC(p, sz)) {
-	erts_garbage_collect(p, sz, reg, live);
-    }
-    hp = p->htop;
-    p->htop += sz;
-    res = make_big(hp);
-    xp = (ErtsDigit*) (hp + 1);
-
-    for (i = ds-1; i >= 0; i--) {
-	ErtsDigit d;
-
-	x *= dbase;      /* "shift" left */
-	d = x;            /* trunc */
-	xp[i] = d;        /* store digit */
-	x -= d;           /* remove integer part */
-    }
-    while ((ds & (BIG_DIGITS_PER_WORD-1)) != 0) {
-	xp[ds++] = 0;
-    }
-
-    if (is_negative) {
-	*hp = make_neg_bignum_header(sz-1);
-    } else {
-	*hp = make_pos_bignum_header(sz-1);
-    }
-    return res;
-}
-
-/********************************************************************************
- * binary_part guards. The actual implementation is in erl_bif_binary.c
- ********************************************************************************/
-Eterm erts_gc_binary_part_3(Process* p, Eterm* reg, Uint live)
-{
-    return erts_gc_binary_part(p,reg,live,0);
-}
-
-Eterm erts_gc_binary_part_2(Process* p, Eterm* reg, Uint live)
-{
-    return erts_gc_binary_part(p,reg,live,1);
-}
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index e9f170870c..4d8c3eb9dd 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -227,7 +227,7 @@ bld_magic_ref_bin_list(Uint **hpp, Uint *szp, ErlOffHeap* oh)
           }).
 */
 
-static void do_calc_mon_size(ErtsMonitor *mon, void *vpsz)
+static int do_calc_mon_size(ErtsMonitor *mon, void *vpsz, Sint reds)
 {
     ErtsMonitorData *mdp = erts_monitor_to_data(mon);
     Uint *psz = vpsz;
@@ -238,7 +238,8 @@ static void do_calc_mon_size(ErtsMonitor *mon, void *vpsz)
     else
         *psz += is_immed(mon->other.item) ? 0 : NC_HEAP_SIZE(mon->other.item);
 
-    *psz += 9; /* CONS + 6-tuple */ 
+    *psz += 9; /* CONS + 6-tuple */
+    return 1;
 }
 
 typedef struct {
@@ -248,7 +249,7 @@ typedef struct {
     Eterm tag;
 } MonListContext;
 
-static void do_make_one_mon_element(ErtsMonitor *mon, void * vpmlc)
+static int do_make_one_mon_element(ErtsMonitor *mon, void * vpmlc, Sint reds)
 {
     ErtsMonitorData *mdp = erts_monitor_to_data(mon);
     MonListContext *pmlc = vpmlc;
@@ -319,6 +320,7 @@ static void do_make_one_mon_element(ErtsMonitor *mon, void * vpmlc)
     pmlc->hp += 7;
     pmlc->res = CONS(pmlc->hp, tup, pmlc->res);
     pmlc->hp += 2;
+    return 1;
 }
 
 static Eterm 
@@ -328,7 +330,7 @@ make_monitor_list(Process *p, int tree, ErtsMonitor *root, Eterm tail)
     Uint sz = 0;
     MonListContext mlc;
     void (*foreach)(ErtsMonitor *,
-                    void (*)(ErtsMonitor *, void *),
+                    ErtsMonitorFunc,
                     void *);
 
     foreach = tree ? erts_monitor_tree_foreach : erts_monitor_list_foreach;
@@ -354,7 +356,7 @@ make_monitor_list(Process *p, int tree, ErtsMonitor *root, Eterm tail)
           }).
 */
 
-static void calc_lnk_size(ErtsLink *lnk, void *vpsz)
+static int calc_lnk_size(ErtsLink *lnk, void *vpsz, Sint reds)
 {
     Uint *psz = vpsz;
     Uint sz = 0;
@@ -364,7 +366,8 @@ static void calc_lnk_size(ErtsLink *lnk, void *vpsz)
 
     *psz += sz;
     *psz += is_immed(lnk->other.item) ? 0 : size_object(lnk->other.item);
-    *psz += 7; /* CONS + 4-tuple */ 
+    *psz += 7; /* CONS + 4-tuple */
+    return 1;
 }
 
 typedef struct {
@@ -374,7 +377,7 @@ typedef struct {
     Eterm tag;
 } LnkListContext;
 
-static void make_one_lnk_element(ErtsLink *lnk, void * vpllc)
+static int make_one_lnk_element(ErtsLink *lnk, void * vpllc, Sint reds)
 {
     LnkListContext *pllc = vpllc;
     Eterm tup, t, pid, id;
@@ -411,6 +414,7 @@ static void make_one_lnk_element(ErtsLink *lnk, void * vpllc)
     pllc->hp += 5;
     pllc->res = CONS(pllc->hp, tup, pllc->res);
     pllc->hp += 2;
+    return 1;
 }
 
 static Eterm 
@@ -420,7 +424,7 @@ make_link_list(Process *p, int tree, ErtsLink *root, Eterm tail)
     Uint sz = 0;
     LnkListContext llc;
     void (*foreach)(ErtsLink *,
-                    void (*)(ErtsLink *, void *),
+                    ErtsLinkFunc,
                     void *);
 
     foreach = tree ? erts_link_tree_foreach : erts_link_list_foreach;
@@ -519,16 +523,17 @@ do {							\
     }							\
  } while (0)
 
-static void collect_one_link(ErtsLink *lnk, void *vmicp)
+static int collect_one_link(ErtsLink *lnk, void *vmicp, Sint reds)
 {
     MonitorInfoCollection *micp = vmicp;
     EXTEND_MONITOR_INFOS(micp);
     micp->mi[micp->mi_i].entity.term = lnk->other.item;
     micp->sz += 2 + NC_HEAP_SIZE(lnk->other.item);
     micp->mi_i++;
+    return 1;
 } 
 
-static void collect_one_origin_monitor(ErtsMonitor *mon, void *vmicp)
+static int collect_one_origin_monitor(ErtsMonitor *mon, void *vmicp, Sint reds)
 {
     if (erts_monitor_is_origin(mon)) {
         MonitorInfoCollection *micp = vmicp;
@@ -573,9 +578,10 @@ static void collect_one_origin_monitor(ErtsMonitor *mon, void *vmicp)
             break;
         }
     }
+    return 1;
 }
 
-static void collect_one_target_monitor(ErtsMonitor *mon, void *vmicp)
+static int collect_one_target_monitor(ErtsMonitor *mon, void *vmicp, Sint reds)
 {
     MonitorInfoCollection *micp = vmicp;
  
@@ -612,8 +618,8 @@ static void collect_one_target_monitor(ErtsMonitor *mon, void *vmicp)
         default:
             break;
         }
-
     }
+    return 1;
 }
 
 typedef struct {
@@ -653,8 +659,8 @@ do {									\
     }									\
  } while (0)
 
-static void
-collect_one_suspend_monitor(ErtsMonitor *mon, void *vsmicp)
+static int
+collect_one_suspend_monitor(ErtsMonitor *mon, void *vsmicp, Sint reds)
 {
     if (mon->type == ERTS_MON_TYPE_SUSPEND) {
         Sint count;
@@ -678,6 +684,7 @@ collect_one_suspend_monitor(ErtsMonitor *mon, void *vsmicp)
 
 	smicp->smi_i++;
     }
+    return 1;
 }
 
 /*
@@ -2586,6 +2593,7 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 
 	/* Need to be the only thread running... */
 	erts_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
+        BIF_P->scheduler_data->current_process = NULL;
 	erts_thr_progress_block();
 
 	if (BIF_ARG_1 == am_info)
@@ -2599,6 +2607,7 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 
 	erts_thr_progress_unblock();
 	erts_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
+       BIF_P->scheduler_data->current_process = BIF_P;
 
 	ASSERT(dsbufp && dsbufp->str);
 	res = new_binary(BIF_P, (byte *) dsbufp->str, dsbufp->str_len);
@@ -2719,9 +2728,7 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	    goto bld_instruction_counts;
 	}
 
-#ifdef DEBUG
 	ASSERT(endp == hp);
-#endif
 
 	BIF_RET(res);
 #endif /* #ifndef ERTS_OPCODE_COUNTER_SUPPORT */
@@ -2981,7 +2988,7 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
     } else if (ERTS_IS_ATOM_STR("context_reductions", BIF_ARG_1)) {
 	BIF_RET(make_small(CONTEXT_REDS));
     } else if (ERTS_IS_ATOM_STR("kernel_poll", BIF_ARG_1)) {
-#ifdef ERTS_ENABLE_KERNEL_POLL
+#if ERTS_ENABLE_KERNEL_POLL
 	BIF_RET(am_true);
 #else
 	BIF_RET(am_false);
@@ -3032,6 +3039,8 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	BIF_RET(erts_nif_taints(BIF_P));
     } else if (ERTS_IS_ATOM_STR("reader_groups_map", BIF_ARG_1)) {
 	BIF_RET(erts_get_reader_groups_map(BIF_P));
+    } else if (ERTS_IS_ATOM_STR("decentralized_counter_groups_map", BIF_ARG_1)) {
+	BIF_RET(erts_get_decentralized_counter_groups_map(BIF_P));
     } else if (ERTS_IS_ATOM_STR("dist_buf_busy_limit", BIF_ARG_1)) {
 	Uint hsz = 0;
 
@@ -3153,19 +3162,23 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	DECL_AM(tag);
 	BIF_RET(AM_tag);
 #endif
+    } else if (ERTS_IS_ATOM_STR("system_logger", BIF_ARG_1)) {
+        BIF_RET(erts_get_system_logger());
     }
 
     BIF_ERROR(BIF_P, BADARG);
 }
 
-static void monitor_size(ErtsMonitor *mon, void *vsz)
+static int monitor_size(ErtsMonitor *mon, void *vsz, Sint reds)
 {
     *((Uint *) vsz) = erts_monitor_size(mon);
+    return 1;
 }
 
-static void link_size(ErtsMonitor *lnk, void *vsz)
+static int link_size(ErtsMonitor *lnk, void *vsz, Sint reds)
 {
     *((Uint *) vsz) = erts_link_size(lnk);
+    return 1;
 }
 
 /**********************************************************************/ 
@@ -4237,7 +4250,10 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 		Uint dflags = (TERM_TO_BINARY_DFLAGS
                                & ~DFLAG_EXPORT_PTR_TAG
                                & ~DFLAG_BIT_BINARIES);
-		BIF_RET(erts_term_to_binary(BIF_P, tp[2], 0, dflags));
+		Eterm res = erts_term_to_binary(BIF_P, tp[2], 0, dflags);
+                if (is_value(res))
+                    BIF_RET(res);
+                BIF_ERROR(BIF_P, SYSTEM_LIMIT);
 	    }
 	    else if (ERTS_IS_ATOM_STR("dist_ctrl", tp[1])) {
 		Eterm res = am_undefined;
@@ -4444,6 +4460,7 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
 			BIF_P->fcalls = reds;
 		    else
 			BIF_P->fcalls = reds - CONTEXT_REDS;
+                    BIF_P->scheduler_data->virtual_reds = 0;
 		}
 		BIF_RET(am_true);
 	    }
@@ -4608,20 +4625,20 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
 	    }
 	}
 	else if (ERTS_IS_ATOM_STR("wait", BIF_ARG_1)) {
-	    if (ERTS_IS_ATOM_STR("deallocations", BIF_ARG_2)) {
-		int flag = ERTS_DEBUG_WAIT_COMPLETED_DEALLOCATIONS;
-		if (erts_debug_wait_completed(BIF_P, flag)) {
-		    ERTS_BIF_YIELD_RETURN(BIF_P, am_ok);
-		}
-	    }
-	    if (ERTS_IS_ATOM_STR("timer_cancellations", BIF_ARG_2)) {
-		int flag = ERTS_DEBUG_WAIT_COMPLETED_TIMER_CANCELLATIONS;
-		if (erts_debug_wait_completed(BIF_P, flag)) {
-		    ERTS_BIF_YIELD_RETURN(BIF_P, am_ok);
-		}
-	    }
+            int flag = 0;
+	    if (ERTS_IS_ATOM_STR("deallocations", BIF_ARG_2))
+                flag = ERTS_DEBUG_WAIT_COMPLETED_DEALLOCATIONS;
+            else if (ERTS_IS_ATOM_STR("timer_cancellations", BIF_ARG_2))
+		flag = ERTS_DEBUG_WAIT_COMPLETED_TIMER_CANCELLATIONS;
+            else if (ERTS_IS_ATOM_STR("aux_work", BIF_ARG_2))
+                flag = ERTS_DEBUG_WAIT_COMPLETED_AUX_WORK;
+
+            if (flag && erts_debug_wait_completed(BIF_P, flag)) {
+                ERTS_BIF_YIELD_RETURN(BIF_P, am_ok);
+            }
 	}
         else if (ERTS_IS_ATOM_STR("broken_halt", BIF_ARG_1)) {
+            erts_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
             broken_halt_test(BIF_ARG_2);
         }
 	else if (ERTS_IS_ATOM_STR("unique_monotonic_integer_state", BIF_ARG_1)) {
@@ -4685,6 +4702,32 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
             BIF_RET(am_notsup);
 #endif
         }
+        else if (ERTS_IS_ATOM_STR("ets_force_split", BIF_ARG_1)) {
+            if (is_tuple(BIF_ARG_2)) {
+                Eterm* tpl = tuple_val(BIF_ARG_2);
+
+                if (erts_ets_force_split(tpl[1], tpl[2] == am_true))
+                    BIF_RET(am_ok);
+            }
+        }
+        else if (ERTS_IS_ATOM_STR("ets_debug_random_split_join", BIF_ARG_1)) {
+            if (is_tuple(BIF_ARG_2)) {
+                Eterm* tpl = tuple_val(BIF_ARG_2);
+
+                if (erts_ets_debug_random_split_join(tpl[1], tpl[2] == am_true))
+                    BIF_RET(am_ok);
+            }
+        }
+        else if (ERTS_IS_ATOM_STR("mbuf", BIF_ARG_1)) {
+            Uint sz = size_object(BIF_ARG_2);
+            ErlHeapFragment* frag = new_message_buffer(sz);
+            Eterm *hp = frag->mem;
+            Eterm copy = copy_struct(BIF_ARG_2, sz, &hp, &frag->off_heap);
+            frag->next = BIF_P->mbuf;
+            BIF_P->mbuf = frag;
+            BIF_P->mbuf_sz += sz;
+            BIF_RET(copy);
+        }
     }
 
     BIF_ERROR(BIF_P, BADARG);
diff --git a/erts/emulator/beam/erl_bif_lists.c b/erts/emulator/beam/erl_bif_lists.c
index aaf262780f..fa2edfef1e 100644
--- a/erts/emulator/beam/erl_bif_lists.c
+++ b/erts/emulator/beam/erl_bif_lists.c
@@ -35,101 +35,270 @@
 
 static Eterm keyfind(int Bif, Process* p, Eterm Key, Eterm Pos, Eterm List);
 
+/* erlang:'++'/2
+ *
+ * Adds a list to another (LHS ++ RHS). For historical reasons this is
+ * implemented by copying LHS and setting its tail to RHS without checking
+ * that RHS is a proper list. [] ++ 'not_a_list' will therefore result in
+ * 'not_a_list', and [1,2] ++ 3 will result in [1,2|3], and this is a bug that
+ * we have to live with. */
 
-static BIF_RETTYPE append(Process* p, Eterm A, Eterm B)
-{
-    Eterm list;
-    Eterm copy;
-    Eterm last;
-    Eterm* hp = NULL;
-    Sint i;
+typedef struct {
+    Eterm lhs_original;
+    Eterm rhs_original;
 
-    list = A;
+    Eterm iterator;
 
-    if (is_nil(list)) {
-        BIF_RET(B);
-    }
+    Eterm result;
+    Eterm *result_cdr;
+} ErtsAppendContext;
+
+static int append_ctx_bin_dtor(Binary *context_bin) {
+    return 1;
+}
+
+static Eterm append_create_trap_state(Process *p,
+                                      ErtsAppendContext *from_context) {
+    ErtsAppendContext *to_context;
+    Binary *state_bin;
+    Eterm *hp;
+
+    state_bin = erts_create_magic_binary(sizeof(ErtsAppendContext),
+                                         append_ctx_bin_dtor);
 
-    if (is_not_list(list)) {
-        BIF_ERROR(p, BADARG);
+    to_context = ERTS_MAGIC_BIN_DATA(state_bin);
+    *to_context = *from_context;
+
+    if (from_context->result_cdr == &from_context->result) {
+        to_context->result_cdr = &to_context->result;
     }
 
-    /* optimistic append on heap first */
+    hp = HAlloc(p, ERTS_MAGIC_REF_THING_SIZE);
+    return erts_mk_magic_ref(&hp, &MSO(p), state_bin);
+}
+
+static BIF_RETTYPE lists_append_alloc(Process *p, ErtsAppendContext *context) {
+    static const Uint CELLS_PER_RED = 40;
+
+    Eterm *alloc_top, *alloc_end;
+    Uint cells_left, max_cells;
+    Eterm lookahead;
+
+    cells_left = max_cells = CELLS_PER_RED * ERTS_BIF_REDS_LEFT(p);
+    lookahead = context->iterator;
+
+#ifdef DEBUG
+    cells_left = max_cells = max_cells / 10 + 1;
+#endif
 
-    if ((i = HeapWordsLeft(p) / 2) < 4) {
-        goto list_tail;
+    while (cells_left != 0 && is_list(lookahead)) {
+        lookahead = CDR(list_val(lookahead));
+        cells_left--;
     }
 
-    hp   = HEAP_TOP(p);
-    copy = last = CONS(hp, CAR(list_val(list)), make_list(hp+2));
-    list = CDR(list_val(list));
-    hp  += 2;
-    i   -= 2; /* don't use the last 2 words (extra i--;) */
-
-    while(i-- && is_list(list)) {
-        Eterm* listp = list_val(list);
-        last = CONS(hp, CAR(listp), make_list(hp+2));
-        list = CDR(listp);
-        hp += 2;
+    BUMP_REDS(p, (max_cells - cells_left) / CELLS_PER_RED);
+
+    if (is_not_list(lookahead) && is_not_nil(lookahead)) {
+        /* It's possible that we're erroring out with an incomplete list, so it
+         * must be terminated or we'll leave a hole in the heap. */
+        *context->result_cdr = NIL;
+        return -1;
     }
 
-    /* A is proper and B is NIL return A as-is, don't update HTOP */
+    alloc_top = HAlloc(p, 2 * (max_cells - cells_left));
+    alloc_end = alloc_top + 2 * (max_cells - cells_left);
+
+    while (alloc_top < alloc_end) {
+        Eterm *cell = list_val(context->iterator);
+
+        ASSERT(context->iterator != lookahead);
+
+        *context->result_cdr = make_list(alloc_top);
+        context->result_cdr = &CDR(alloc_top);
+        CAR(alloc_top) = CAR(cell);
 
-    if (is_nil(list) && is_nil(B)) {
-        BIF_RET(A);
+        context->iterator = CDR(cell);
+        alloc_top += 2;
     }
 
-    if (is_nil(list)) {
-        HEAP_TOP(p) = hp;
-        CDR(list_val(last)) = B;
-        BIF_RET(copy);
+    if (is_list(context->iterator)) {
+        /* The result only has to be terminated when returning it to the user,
+         * but we're doing it when trapping as well to prevent headaches when
+         * debugging. */
+        *context->result_cdr = NIL;
+        ASSERT(cells_left == 0);
+        return 0;
+    }
+
+    *context->result_cdr = context->rhs_original;
+    ASSERT(is_nil(context->iterator));
+
+    if (is_nil(context->rhs_original)) {
+        /* The list we created was equal to the original, so we'll return that
+         * in the hopes that the garbage we created can be removed soon. */
+        context->result = context->lhs_original;
     }
 
-list_tail:
+    return 1;
+}
+
+static BIF_RETTYPE lists_append_onheap(Process *p, ErtsAppendContext *context) {
+    static const Uint CELLS_PER_RED = 60;
+
+    Eterm *alloc_start, *alloc_top, *alloc_end;
+    Uint cells_left, max_cells;
+
+    cells_left = max_cells = CELLS_PER_RED * ERTS_BIF_REDS_LEFT(p);
+
+#ifdef DEBUG
+    cells_left = max_cells = max_cells / 10 + 1;
+#endif
+
+    ASSERT(HEAP_LIMIT(p) >= HEAP_TOP(p) + 2);
+    alloc_start = HEAP_TOP(p);
+    alloc_end = HEAP_LIMIT(p) - 2;
+    alloc_top = alloc_start;
+
+    /* Don't process more cells than we have reductions for. */
+    alloc_end = MIN(alloc_top + (cells_left * 2), alloc_end);
+
+    while (alloc_top < alloc_end && is_list(context->iterator)) {
+        Eterm *cell = list_val(context->iterator);
+
+        *context->result_cdr = make_list(alloc_top);
+        context->result_cdr = &CDR(alloc_top);
+        CAR(alloc_top) = CAR(cell);
 
-    if ((i = erts_list_length(list)) < 0) {
-        BIF_ERROR(p, BADARG);
+        context->iterator = CDR(cell);
+        alloc_top += 2;
     }
 
-    /* remaining list was proper and B is NIL */
-    if (is_nil(B)) {
-        BIF_RET(A);
+    cells_left -= (alloc_top - alloc_start) / 2;
+    HEAP_TOP(p) = alloc_top;
+
+    ASSERT(cells_left >= 0 && cells_left <= max_cells);
+    BUMP_REDS(p, (max_cells - cells_left) / CELLS_PER_RED);
+
+    if (is_not_list(context->iterator) && is_not_nil(context->iterator)) {
+        *context->result_cdr = NIL;
+        return -1;
     }
 
-    if (hp) {
-        /* Note: fall through case, already written
-         * on the heap.
-         * The last 2 words of the heap is not written yet
-         */
-        Eterm *hp_save = hp;
-        ASSERT(i != 0);
-        HEAP_TOP(p) = hp + 2;
-        if (i == 1) {
-            hp[0] = CAR(list_val(list));
-            hp[1] = B;
-            BIF_RET(copy);
+    if (is_list(context->iterator)) {
+        if (cells_left > CELLS_PER_RED) {
+            return lists_append_alloc(p, context);
         }
-        hp   = HAlloc(p, 2*(i - 1));
-        last = CONS(hp_save, CAR(list_val(list)), make_list(hp));
-    } else {
-        hp   = HAlloc(p, 2*i);
-        copy = last = CONS(hp, CAR(list_val(list)), make_list(hp+2));
-        hp  += 2;
+
+        *context->result_cdr = NIL;
+        return 0;
+    }
+
+    *context->result_cdr = context->rhs_original;
+    ASSERT(is_nil(context->iterator));
+
+    if (is_nil(context->rhs_original)) {
+        context->result = context->lhs_original;
+    }
+
+    return 1;
+}
+
+static int append_continue(Process *p, ErtsAppendContext *context) {
+    /* We build the result on the unused part of the heap if possible to save
+     * us the trouble of having to figure out the list size. We fall back to
+     * lists_append_alloc when we run out of space. */
+    if (HeapWordsLeft(p) > 8) {
+        return lists_append_onheap(p, context);
     }
 
-    list = CDR(list_val(list));
-    i--;
+    return lists_append_alloc(p, context);
+}
+
+static int append_start(Process *p, Eterm lhs, Eterm rhs,
+                        ErtsAppendContext *context) {
+    context->lhs_original = lhs;
+    context->rhs_original = rhs;
+
+    context->result_cdr = &context->result;
+    context->result = NIL;
+
+    context->iterator = lhs;
+
+    return append_continue(p, context);
+}
+
+/* erlang:'++'/2 */
+static Eterm append(Export *bif_entry, BIF_ALIST_2) {
+    Eterm lhs = BIF_ARG_1, rhs = BIF_ARG_2;
+
+    if (is_nil(lhs)) {
+        /* This is buggy but expected, `[] ++ 'not_a_list'` has always resulted
+         * in 'not_a_list'. */
+        return rhs;
+    } else if (is_list(lhs)) {
+        /* We start with the context on the stack in the hopes that we won't
+         * have to trap. */
+        ErtsAppendContext context;
+        int res;
+
+        res = append_start(BIF_P, lhs, rhs, &context);
+
+        if (res == 0) {
+            Eterm state_mref;
+
+            state_mref = append_create_trap_state(BIF_P, &context);
+            erts_set_gc_state(BIF_P, 0);
+
+            BIF_TRAP2(bif_entry, BIF_P, state_mref, NIL);
+        }
+
+        if (res < 0) {
+            ASSERT(is_nil(*context.result_cdr));
+            BIF_ERROR(BIF_P, BADARG);
+        }
+
+        ASSERT(*context.result_cdr == context.rhs_original);
+        BIF_RET(context.result);
+    } else if (is_internal_magic_ref(lhs)) {
+        ErtsAppendContext *context;
+        int (*dtor)(Binary*);
+        Binary *magic_bin;
+
+        int res;
+
+        magic_bin = erts_magic_ref2bin(lhs);
+        dtor = ERTS_MAGIC_BIN_DESTRUCTOR(magic_bin);
+
+        if (dtor != append_ctx_bin_dtor) {
+            BIF_ERROR(BIF_P, BADARG);
+        }
+
+        ASSERT(BIF_P->flags & F_DISABLE_GC);
+        ASSERT(rhs == NIL);
+
+        context = ERTS_MAGIC_BIN_DATA(magic_bin);
+        res = append_continue(BIF_P, context);
+
+        if (res == 0) {
+            BIF_TRAP2(bif_entry, BIF_P, lhs, NIL);
+        }
+
+        erts_set_gc_state(BIF_P, 1);
+
+        if (res < 0) {
+            ASSERT(is_nil(*context->result_cdr));
+            ERTS_BIF_ERROR_TRAPPED2(BIF_P, BADARG, bif_entry,
+                                    context->lhs_original,
+                                    context->rhs_original);
+        }
 
-    ASSERT(i > -1);
-    while(i--) {
-        Eterm* listp = list_val(list);
-        last = CONS(hp, CAR(listp), make_list(hp+2));
-        list = CDR(listp);
-        hp  += 2;
+        ASSERT(*context->result_cdr == context->rhs_original);
+        BIF_RET(context->result);
     }
 
-    CDR(list_val(last)) = B;
-    BIF_RET(copy);
+    ASSERT(!(BIF_P->flags & F_DISABLE_GC));
+
+    BIF_ERROR(BIF_P, BADARG);
 }
 
 /*
@@ -139,12 +308,12 @@ list_tail:
 Eterm
 ebif_plusplus_2(BIF_ALIST_2)
 {
-    return append(BIF_P, BIF_ARG_1, BIF_ARG_2);
+    return append(bif_export[BIF_ebif_plusplus_2], BIF_CALL_ARGS);
 }
 
 BIF_RETTYPE append_2(BIF_ALIST_2)
 {
-    return append(BIF_P, BIF_ARG_1, BIF_ARG_2);
+    return append(bif_export[BIF_append_2], BIF_CALL_ARGS);
 }
 
 /* erlang:'--'/2
@@ -244,12 +413,25 @@ typedef struct {
 #define ERTS_RBT_GET_LEFT(T) ((T)->left)
 #define ERTS_RBT_SET_LEFT(T, L) ((T)->left = (L))
 #define ERTS_RBT_GET_KEY(T) ((T)->key)
-#define ERTS_RBT_CMP_KEYS(KX, KY) CMP_TERM(KX, KY)
+#define ERTS_RBT_CMP_KEYS(KX, KY) subtract_term_cmp((KX), (KY))
 #define ERTS_RBT_WANT_LOOKUP_INSERT
 #define ERTS_RBT_WANT_LOOKUP
 #define ERTS_RBT_WANT_DELETE
 #define ERTS_RBT_UNDEF
 
+/* erl_rbtree expects comparisons to return an int */
+static int subtract_term_cmp(Eterm a, Eterm b) {
+    Sint res = CMP_TERM(a, b);
+
+    if (res < 0) {
+        return -1;
+    } else if (res > 0) {
+        return 1;
+    }
+
+    return 0;
+}
+
 #include "erl_rbtree.h"
 
 static int subtract_continue(Process *p, ErtsSubtractContext *context);
@@ -915,7 +1097,7 @@ static BIF_RETTYPE lists_reverse_alloc(Process *c_p,
     list = list_in;
     tail = tail_in;
 
-    cells_left = max_cells = CELLS_PER_RED * (1 + ERTS_BIF_REDS_LEFT(c_p));
+    cells_left = max_cells = CELLS_PER_RED * ERTS_BIF_REDS_LEFT(c_p);
     lookahead = list;
 
     while (cells_left != 0 && is_list(lookahead)) {
@@ -964,7 +1146,7 @@ static BIF_RETTYPE lists_reverse_onheap(Process *c_p,
     list = list_in;
     tail = tail_in;
 
-    cells_left = max_cells = CELLS_PER_RED * (1 + ERTS_BIF_REDS_LEFT(c_p));
+    cells_left = max_cells = CELLS_PER_RED * ERTS_BIF_REDS_LEFT(c_p);
 
     ASSERT(HEAP_LIMIT(c_p) >= HEAP_TOP(c_p) + 2);
     alloc_start = HEAP_TOP(c_p);
@@ -992,8 +1174,6 @@ static BIF_RETTYPE lists_reverse_onheap(Process *c_p,
     if (is_nil(list)) {
         BIF_RET(tail);
     } else if (is_list(list)) {
-        ASSERT(is_list(tail));
-
         if (cells_left > CELLS_PER_RED) {
             return lists_reverse_alloc(c_p, list, tail);
         }
diff --git a/erts/emulator/beam/erl_bif_persistent.c b/erts/emulator/beam/erl_bif_persistent.c
index 9dca768a18..8662a9e33a 100644
--- a/erts/emulator/beam/erl_bif_persistent.c
+++ b/erts/emulator/beam/erl_bif_persistent.c
@@ -37,15 +37,6 @@
 #include "erl_binary.h"
 
 /*
- * The limit for the number of persistent terms before
- * a warning is issued.
- */
-
-#define WARNING_LIMIT 20000
-#define XSTR(s) STR(s)
-#define STR(s) #s
-
-/*
  * Parameters for the hash table.
  */
 #define INITIAL_SIZE 8
@@ -73,14 +64,69 @@ typedef struct trap_data {
     Uint memory;    /* Used by info/0 to count used memory */
 } TrapData;
 
+typedef enum {
+    ERTS_PERSISTENT_TERM_CPY_PLACE_START,
+    ERTS_PERSISTENT_TERM_CPY_PLACE_1,
+    ERTS_PERSISTENT_TERM_CPY_PLACE_2,
+    ERTS_PERSISTENT_TERM_CPY_PLACE_3
+} ErtsPersistentTermCpyTableLocation;
+
+typedef enum {
+    ERTS_PERSISTENT_TERM_CPY_NO_REHASH = 0,
+    ERTS_PERSISTENT_TERM_CPY_REHASH = 1,
+    ERTS_PERSISTENT_TERM_CPY_TEMP = 2
+} ErtsPersistentTermCpyTableType;
+
+typedef struct {
+    HashTable* old_table; /* in param */
+    Uint new_size; /* in param */
+    ErtsPersistentTermCpyTableType copy_type; /* in param */
+    Uint max_iterations; /* in param */
+    ErtsPersistentTermCpyTableLocation location; /* in/out param */
+    Uint iterations_done; /* in/out param */
+    Uint total_iterations_done; /* in/out param */
+    HashTable* new_table; /* out param */
+} ErtsPersistentTermCpyTableCtx;
+
+typedef enum {
+    PUT2_TRAP_LOCATION_NEW_KEY,
+    PUT2_TRAP_LOCATION_REPLACE_VALUE
+} ErtsPersistentTermPut2TrapLocation;
+
+typedef struct {
+    ErtsPersistentTermPut2TrapLocation trap_location;
+    Eterm key;
+    Eterm term;
+    Uint entry_index;
+    HashTable* hash_table;
+    Eterm heap[3];
+    Eterm tuple;
+    ErtsPersistentTermCpyTableCtx cpy_ctx;
+} ErtsPersistentTermPut2Context;
+
+typedef enum {
+    ERASE1_TRAP_LOCATION_TMP_COPY,
+    ERASE1_TRAP_LOCATION_FINAL_COPY
+} ErtsPersistentTermErase1TrapLocation;
+
+typedef struct {
+    ErtsPersistentTermErase1TrapLocation trap_location;
+    Eterm key;
+    HashTable* old_table;
+    HashTable* new_table;
+    Uint entry_index;
+    Eterm old_term;
+    HashTable* tmp_table;
+    ErtsPersistentTermCpyTableCtx cpy_ctx;
+} ErtsPersistentTermErase1Context;
+
 /*
  * Declarations of local functions.
  */
 
 static HashTable* create_initial_table(void);
 static Uint lookup(HashTable* hash_table, Eterm key);
-static HashTable* copy_table(HashTable* old_table, Uint new_size, int rehash);
-static HashTable* tmp_table_copy(HashTable* old_table);
+static HashTable* copy_table(ErtsPersistentTermCpyTableCtx* ctx);
 static int try_seize_update_permission(Process* c_p);
 static void release_update_permission(int release_updater);
 static void table_updater(void* table);
@@ -127,7 +173,6 @@ static Process* updater_process = NULL;
 
 /* Protected by update_table_permission_mtx */
 static ErtsThrPrgrLaterOp thr_prog_op;
-static int issued_warning = 0;
 
 /*
  * Queue of hash tables to be deleted.
@@ -139,7 +184,7 @@ static HashTable** delete_queue_tail = &delete_queue_head;
 
 /*
  * The following variables are only used during crash dumping. They
- * are intialized by erts_init_persistent_dumping().
+ * are initialized by erts_init_persistent_dumping().
  */
 
 ErtsLiteralArea** erts_persistent_areas;
@@ -188,101 +233,181 @@ void erts_init_bif_persistent_term(void)
 			  &persistent_term_info_trap);
 }
 
+/*
+ * Macro used for trapping in persistent_term_put_2 and
+ * persistent_term_erase_1
+ */
+#define TRAPPING_COPY_TABLE(TABLE_DEST, OLD_TABLE, NEW_SIZE, COPY_TYPE, LOC_NAME, TRAP_CODE) \
+    do {                                                                \
+        ctx->cpy_ctx = (ErtsPersistentTermCpyTableCtx){                 \
+            .old_table = OLD_TABLE,                                     \
+            .new_size = NEW_SIZE,                                       \
+            .copy_type = COPY_TYPE,                                     \
+            .location = ERTS_PERSISTENT_TERM_CPY_PLACE_START            \
+        };                                                              \
+        L_ ## LOC_NAME:                                                 \
+        ctx->cpy_ctx.max_iterations = MAX(1, max_iterations);           \
+        TABLE_DEST = copy_table(&ctx->cpy_ctx);                         \
+        iterations_until_trap -= ctx->cpy_ctx.total_iterations_done;    \
+        if (TABLE_DEST == NULL) {                                       \
+            ctx->trap_location = LOC_NAME;                              \
+            erts_set_gc_state(BIF_P, 0);                                \
+            BUMP_ALL_REDS(BIF_P);                                       \
+            TRAP_CODE;                                                  \
+        }                                                               \
+    } while (0)
+
+static int persistent_term_put_2_ctx_bin_dtor(Binary *context_bin)
+{
+    ErtsPersistentTermPut2Context* ctx = ERTS_MAGIC_BIN_DATA(context_bin);
+    if (ctx->cpy_ctx.new_table != NULL) {
+        erts_free(ERTS_ALC_T_PERSISTENT_TERM, ctx->cpy_ctx.new_table);
+        release_update_permission(0);
+    }
+    return 1;
+}
+/*
+ * A linear congruential generator that is used in the debug emulator
+ * to trap after a random number of iterations in
+ * persistent_term_put_2 and persistent_term_erase_1.
+ *
+ * https://en.wikipedia.org/wiki/Linear_congruential_generator
+ */
+#define GET_SMALL_RANDOM_INT(SEED)              \
+    (1103515245 * (SEED) + 12345)  % 227
+
 BIF_RETTYPE persistent_term_put_2(BIF_ALIST_2)
 {
-    Eterm key;
-    Eterm term;
-    Eterm heap[3];
-    Eterm tuple;
-    HashTable* hash_table;
-    Uint term_size;
-    Uint lit_area_size;
-    ErlOffHeap code_off_heap;
-    ErtsLiteralArea* literal_area;
-    erts_shcopy_t info;
-    Eterm* ptr;
-    Uint entry_index;
+    static const Uint ITERATIONS_PER_RED = 32;
+    ErtsPersistentTermPut2Context* ctx;
+    Eterm state_mref = THE_NON_VALUE;
+    long iterations_until_trap;
+    long max_iterations;
+#define PUT_TRAP_CODE                                                   \
+    BIF_TRAP2(bif_export[BIF_persistent_term_put_2], BIF_P, state_mref, BIF_ARG_2)
+#define TRAPPING_COPY_TABLE_PUT(TABLE_DEST, OLD_TABLE, NEW_SIZE, COPY_TYPE, LOC_NAME) \
+    TRAPPING_COPY_TABLE(TABLE_DEST, OLD_TABLE, NEW_SIZE, COPY_TYPE, LOC_NAME, PUT_TRAP_CODE)
+
+#ifdef DEBUG
+        (void)ITERATIONS_PER_RED;
+        iterations_until_trap = max_iterations =
+            GET_SMALL_RANDOM_INT(ERTS_BIF_REDS_LEFT(BIF_P) + (Uint)&ctx);
+#else
+        iterations_until_trap = max_iterations =
+            ITERATIONS_PER_RED * ERTS_BIF_REDS_LEFT(BIF_P);
+#endif
+    if (is_internal_magic_ref(BIF_ARG_1) &&
+        (ERTS_MAGIC_BIN_DESTRUCTOR(erts_magic_ref2bin(BIF_ARG_1)) ==
+         persistent_term_put_2_ctx_bin_dtor)) {
+        /* Restore state after a trap */
+        Binary* state_bin;
+        state_mref = BIF_ARG_1;
+        state_bin = erts_magic_ref2bin(state_mref);
+        ctx = ERTS_MAGIC_BIN_DATA(state_bin);
+        ASSERT(BIF_P->flags & F_DISABLE_GC);
+        erts_set_gc_state(BIF_P, 1);
+        switch (ctx->trap_location) {
+        case PUT2_TRAP_LOCATION_NEW_KEY:
+            goto L_PUT2_TRAP_LOCATION_NEW_KEY;
+        case PUT2_TRAP_LOCATION_REPLACE_VALUE:
+            goto L_PUT2_TRAP_LOCATION_REPLACE_VALUE;
+        }
+    } else {
+        /* Save state in magic bin in case trapping is necessary */
+        Eterm* hp;
+        Binary* state_bin = erts_create_magic_binary(sizeof(ErtsPersistentTermPut2Context),
+                                                     persistent_term_put_2_ctx_bin_dtor);
+        hp = HAlloc(BIF_P, ERTS_MAGIC_REF_THING_SIZE);
+        state_mref = erts_mk_magic_ref(&hp, &MSO(BIF_P), state_bin);
+        ctx = ERTS_MAGIC_BIN_DATA(state_bin);
+        /*
+         * IMPORTANT: The following field is used to detect if
+         * persistent_term_put_2_ctx_bin_dtor needs to free memory
+         */
+        ctx->cpy_ctx.new_table = NULL;
+    }
+
 
     if (!try_seize_update_permission(BIF_P)) {
 	ERTS_BIF_YIELD2(bif_export[BIF_persistent_term_put_2],
                         BIF_P, BIF_ARG_1, BIF_ARG_2);
     }
+    ctx->hash_table = (HashTable *) erts_atomic_read_nob(&the_hash_table);
 
-    hash_table = (HashTable *) erts_atomic_read_nob(&the_hash_table);
+    ctx->key = BIF_ARG_1;
+    ctx->term = BIF_ARG_2;
 
-    key = BIF_ARG_1;
-    term = BIF_ARG_2;
+    ctx->entry_index = lookup(ctx->hash_table, ctx->key);
 
-    entry_index = lookup(hash_table, key);
-
-    heap[0] = make_arityval(2);
-    heap[1] = key;
-    heap[2] = term;
-    tuple = make_tuple(heap);
+    ctx->heap[0] = make_arityval(2);
+    ctx->heap[1] = ctx->key;
+    ctx->heap[2] = ctx->term;
+    ctx->tuple = make_tuple(ctx->heap);
 
-    if (is_nil(hash_table->term[entry_index])) {
-        Uint size = hash_table->allocated;
-        if (MUST_GROW(hash_table)) {
-            size *= 2;
+    if (is_nil(ctx->hash_table->term[ctx->entry_index])) {
+        Uint new_size = ctx->hash_table->allocated;
+        if (MUST_GROW(ctx->hash_table)) {
+            new_size *= 2;
         }
-        hash_table = copy_table(hash_table, size, 0);
-        entry_index = lookup(hash_table, key);
-        hash_table->num_entries++;
+        TRAPPING_COPY_TABLE_PUT(ctx->hash_table,
+                                ctx->hash_table,
+                                new_size,
+                                ERTS_PERSISTENT_TERM_CPY_NO_REHASH,
+                                PUT2_TRAP_LOCATION_NEW_KEY);
+        ctx->entry_index = lookup(ctx->hash_table, ctx->key);
+        ctx->hash_table->num_entries++;
     } else {
-        Eterm tuple = hash_table->term[entry_index];
+        Eterm tuple = ctx->hash_table->term[ctx->entry_index];
         Eterm old_term;
 
         ASSERT(is_tuple_arity(tuple, 2));
         old_term = boxed_val(tuple)[2];
-        if (EQ(term, old_term)) {
+        if (EQ(ctx->term, old_term)) {
             /* Same value. No need to update anything. */
             release_update_permission(0);
             BIF_RET(am_ok);
         } else {
             /* Mark the old term for deletion. */
-            mark_for_deletion(hash_table, entry_index);
-            hash_table = copy_table(hash_table, hash_table->allocated, 0);
+            mark_for_deletion(ctx->hash_table, ctx->entry_index);
+            TRAPPING_COPY_TABLE_PUT(ctx->hash_table,
+                                    ctx->hash_table,
+                                    ctx->hash_table->allocated,
+                                    ERTS_PERSISTENT_TERM_CPY_NO_REHASH,
+                                    PUT2_TRAP_LOCATION_REPLACE_VALUE);
         }
     }
 
-    /*
-     * Preserve internal sharing in the term by using the
-     * sharing-preserving functions. However, literals must
-     * be copied in case the module holding them are unloaded.
-     */
-    INITIALIZE_SHCOPY(info);
-    info.copy_literals = 1;
-    term_size = copy_shared_calculate(tuple, &info);
-    ERTS_INIT_OFF_HEAP(&code_off_heap);
-    lit_area_size = ERTS_LITERAL_AREA_ALLOC_SIZE(term_size);
-    literal_area = erts_alloc(ERTS_ALC_T_LITERAL, lit_area_size);
-    ptr = &literal_area->start[0];
-    literal_area->end = ptr + term_size;
-    tuple = copy_shared_perform(tuple, term_size, &info, &ptr, &code_off_heap);
-    ASSERT(tuple_val(tuple) == literal_area->start);
-    literal_area->off_heap = code_off_heap.first;
-    DESTROY_SHCOPY(info);
-    erts_set_literal_tag(&tuple, literal_area->start, term_size);
-    hash_table->term[entry_index] = tuple;
-
-    erts_schedule_thr_prgr_later_op(table_updater, hash_table, &thr_prog_op);
-    suspend_updater(BIF_P);
-
-    /*
-     * Issue a warning once if the warning limit has been exceeded.
-     */
-
-    if (hash_table->num_entries > WARNING_LIMIT && issued_warning == 0) {
-        static char w[] =
-            "More than " XSTR(WARNING_LIMIT) " persistent terms "
-            "have been created.\n"
-            "It is recommended to avoid creating an excessive number of\n"
-            "persistent terms, as creation and deletion of persistent terms\n"
-            "will be slower as the number of persistent terms increases.\n";
-        issued_warning = 1;
-	erts_send_warning_to_logger_str(BIF_P->group_leader, w);
+    {
+        Uint term_size;
+        Uint lit_area_size;
+        ErlOffHeap code_off_heap;
+        ErtsLiteralArea* literal_area;
+        erts_shcopy_t info;
+        Eterm* ptr;
+        /*
+         * Preserve internal sharing in the term by using the
+         * sharing-preserving functions. However, literals must
+         * be copied in case the module holding them are unloaded.
+         */
+        INITIALIZE_SHCOPY(info);
+        info.copy_literals = 1;
+        term_size = copy_shared_calculate(ctx->tuple, &info);
+        ERTS_INIT_OFF_HEAP(&code_off_heap);
+        lit_area_size = ERTS_LITERAL_AREA_ALLOC_SIZE(term_size);
+        literal_area = erts_alloc(ERTS_ALC_T_LITERAL, lit_area_size);
+        ptr = &literal_area->start[0];
+        literal_area->end = ptr + term_size;
+        ctx->tuple = copy_shared_perform(ctx->tuple, term_size, &info, &ptr, &code_off_heap);
+        ASSERT(tuple_val(ctx->tuple) == literal_area->start);
+        literal_area->off_heap = code_off_heap.first;
+        DESTROY_SHCOPY(info);
+        erts_set_literal_tag(&ctx->tuple, literal_area->start, term_size);
+        ctx->hash_table->term[ctx->entry_index] = ctx->tuple;
+
+        erts_schedule_thr_prgr_later_op(table_updater, ctx->hash_table, &thr_prog_op);
+        suspend_updater(BIF_P);
     }
-
+    BUMP_REDS(BIF_P, (max_iterations - iterations_until_trap) / ITERATIONS_PER_RED);
     ERTS_BIF_YIELD_RETURN(BIF_P, am_ok);
 }
 
@@ -332,26 +457,101 @@ BIF_RETTYPE persistent_term_get_1(BIF_ALIST_1)
     BIF_ERROR(BIF_P, BADARG);
 }
 
-BIF_RETTYPE persistent_term_erase_1(BIF_ALIST_1)
+BIF_RETTYPE persistent_term_get_2(BIF_ALIST_2)
 {
     Eterm key = BIF_ARG_1;
-    HashTable* old_table;
-    HashTable* new_table;
+    Eterm result = BIF_ARG_2;
+    HashTable* hash_table = (HashTable *) erts_atomic_read_nob(&the_hash_table);
     Uint entry_index;
-    Eterm old_term;
+    Eterm term;
+
+    entry_index = lookup(hash_table, key);
+    term = hash_table->term[entry_index];
+    if (is_boxed(term)) {
+        ASSERT(is_tuple_arity(term, 2));
+        result = tuple_val(term)[2];
+    }
+    BIF_RET(result);
+}
+
+static int persistent_term_erase_1_ctx_bin_dtor(Binary *context_bin)
+{
+    ErtsPersistentTermErase1Context* ctx = ERTS_MAGIC_BIN_DATA(context_bin);
+    if (ctx->cpy_ctx.new_table != NULL) {
+        if (ctx->cpy_ctx.copy_type == ERTS_PERSISTENT_TERM_CPY_TEMP) {
+            erts_free(ERTS_ALC_T_PERSISTENT_TERM_TMP, ctx->cpy_ctx.new_table);
+        } else {
+            erts_free(ERTS_ALC_T_PERSISTENT_TERM, ctx->cpy_ctx.new_table);
+        }
+        if (ctx->tmp_table != NULL) {
+            erts_free(ERTS_ALC_T_PERSISTENT_TERM_TMP, ctx->tmp_table);
+        }
+        release_update_permission(0);
+    }
+    return 1;
+}
 
+BIF_RETTYPE persistent_term_erase_1(BIF_ALIST_1)
+{
+    static const Uint ITERATIONS_PER_RED = 32;
+    ErtsPersistentTermErase1Context* ctx;
+    Eterm state_mref = THE_NON_VALUE;
+    long iterations_until_trap;
+    long max_iterations;
+#ifdef DEBUG
+        (void)ITERATIONS_PER_RED;
+        iterations_until_trap = max_iterations =
+            GET_SMALL_RANDOM_INT(ERTS_BIF_REDS_LEFT(BIF_P) + (Uint)&ctx);
+#else
+        iterations_until_trap = max_iterations =
+            ITERATIONS_PER_RED * ERTS_BIF_REDS_LEFT(BIF_P);
+#endif
+#define ERASE_TRAP_CODE                                                 \
+        BIF_TRAP1(bif_export[BIF_persistent_term_erase_1], BIF_P, state_mref);
+#define TRAPPING_COPY_TABLE_ERASE(TABLE_DEST, OLD_TABLE, NEW_SIZE, REHASH, LOC_NAME) \
+        TRAPPING_COPY_TABLE(TABLE_DEST, OLD_TABLE, NEW_SIZE, REHASH, LOC_NAME, ERASE_TRAP_CODE)
+    if (is_internal_magic_ref(BIF_ARG_1) &&
+        (ERTS_MAGIC_BIN_DESTRUCTOR(erts_magic_ref2bin(BIF_ARG_1)) ==
+         persistent_term_erase_1_ctx_bin_dtor)) {
+        /* Restore the state after a trap */
+        Binary* state_bin;
+        state_mref = BIF_ARG_1;
+        state_bin = erts_magic_ref2bin(state_mref);
+        ctx = ERTS_MAGIC_BIN_DATA(state_bin);
+        ASSERT(BIF_P->flags & F_DISABLE_GC);
+        erts_set_gc_state(BIF_P, 1);
+        switch (ctx->trap_location) {
+        case ERASE1_TRAP_LOCATION_TMP_COPY:
+            goto L_ERASE1_TRAP_LOCATION_TMP_COPY;
+        case ERASE1_TRAP_LOCATION_FINAL_COPY:
+            goto L_ERASE1_TRAP_LOCATION_FINAL_COPY;
+        }
+    } else {
+        /* Save state in magic bin in case trapping is necessary */
+        Eterm* hp;
+        Binary* state_bin = erts_create_magic_binary(sizeof(ErtsPersistentTermErase1Context),
+                                                     persistent_term_erase_1_ctx_bin_dtor);
+        hp = HAlloc(BIF_P, ERTS_MAGIC_REF_THING_SIZE);
+        state_mref = erts_mk_magic_ref(&hp, &MSO(BIF_P), state_bin);
+        ctx = ERTS_MAGIC_BIN_DATA(state_bin);
+        /*
+         * IMPORTANT: The following two fields are used to detect if
+         * persistent_term_erase_1_ctx_bin_dtor needs to free memory
+         */
+        ctx->cpy_ctx.new_table = NULL;
+        ctx->tmp_table = NULL;
+    }
     if (!try_seize_update_permission(BIF_P)) {
 	ERTS_BIF_YIELD1(bif_export[BIF_persistent_term_erase_1],
                         BIF_P, BIF_ARG_1);
     }
 
-    old_table = (HashTable *) erts_atomic_read_nob(&the_hash_table);
-    entry_index = lookup(old_table, key);
-    old_term = old_table->term[entry_index];
-    if (is_boxed(old_term)) {
+    ctx->key = BIF_ARG_1;
+    ctx->old_table = (HashTable *) erts_atomic_read_nob(&the_hash_table);
+    ctx->entry_index = lookup(ctx->old_table, ctx->key);
+    ctx->old_term = ctx->old_table->term[ctx->entry_index];
+    if (is_boxed(ctx->old_term)) {
         Uint new_size;
-        HashTable* tmp_table;
-
         /*
          * Since we don't use any delete markers, we must rehash
          * the table when deleting terms to ensure that all terms
@@ -361,8 +561,12 @@ BIF_RETTYPE persistent_term_erase_1(BIF_ALIST_1)
          * temporary table copy of the same size as the old one.
          */
 
-        ASSERT(is_tuple_arity(old_term, 2));
-        tmp_table = tmp_table_copy(old_table);
+        ASSERT(is_tuple_arity(ctx->old_term, 2));
+        TRAPPING_COPY_TABLE_ERASE(ctx->tmp_table,
+                                  ctx->old_table,
+                                  ctx->old_table->allocated,
+                                  ERTS_PERSISTENT_TERM_CPY_TEMP,
+                                  ERASE1_TRAP_LOCATION_TMP_COPY);
 
         /*
          * Delete the term from the temporary table. Then copy the
@@ -370,18 +574,28 @@ BIF_RETTYPE persistent_term_erase_1(BIF_ALIST_1)
          * while copying.
          */
 
-        tmp_table->term[entry_index] = NIL;
-        tmp_table->num_entries--;
-        new_size = tmp_table->allocated;
-        if (MUST_SHRINK(tmp_table)) {
+        ctx->tmp_table->term[ctx->entry_index] = NIL;
+        ctx->tmp_table->num_entries--;
+        new_size = ctx->tmp_table->allocated;
+        if (MUST_SHRINK(ctx->tmp_table)) {
             new_size /= 2;
         }
-        new_table = copy_table(tmp_table, new_size, 1);
-        erts_free(ERTS_ALC_T_TMP, tmp_table);
+        TRAPPING_COPY_TABLE_ERASE(ctx->new_table,
+                                  ctx->tmp_table,
+                                  new_size,
+                                  ERTS_PERSISTENT_TERM_CPY_REHASH,
+                                  ERASE1_TRAP_LOCATION_FINAL_COPY);
+        erts_free(ERTS_ALC_T_PERSISTENT_TERM_TMP, ctx->tmp_table);
+        /*
+         * IMPORTANT: Memory management depends on that ctx->tmp_table
+         * is set to NULL on the line below
+         */
+        ctx->tmp_table = NULL;
 
-        mark_for_deletion(old_table, entry_index);
-        erts_schedule_thr_prgr_later_op(table_updater, new_table, &thr_prog_op);
+        mark_for_deletion(ctx->old_table, ctx->entry_index);
+        erts_schedule_thr_prgr_later_op(table_updater, ctx->new_table, &thr_prog_op);
         suspend_updater(BIF_P);
+        BUMP_REDS(BIF_P, (max_iterations - iterations_until_trap) / ITERATIONS_PER_RED);
         ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
     }
 
@@ -389,7 +603,7 @@ BIF_RETTYPE persistent_term_erase_1(BIF_ALIST_1)
      * Key is not present. Nothing to do.
      */
 
-    ASSERT(is_nil(old_term));
+    ASSERT(is_nil(ctx->old_term));
     release_update_permission(0);
     BIF_RET(am_false);
 }
@@ -723,65 +937,104 @@ lookup(HashTable* hash_table, Eterm key)
 }
 
 static HashTable*
-tmp_table_copy(HashTable* old_table)
+copy_table(ErtsPersistentTermCpyTableCtx* ctx)
 {
-    Uint size = old_table->allocated;
-    HashTable* tmp_table;
+    Uint old_size = ctx->old_table->allocated;
     Uint i;
-
-    tmp_table = (HashTable *) erts_alloc(ERTS_ALC_T_TMP,
-                                         sizeof(HashTable) +
-                                         sizeof(Eterm) * (size-1));
-    *tmp_table = *old_table;
-    for (i = 0; i < size; i++) {
-        tmp_table->term[i] = old_table->term[i];
+    ErtsAlcType_t alloc_type;
+    ctx->total_iterations_done = 0;
+    switch(ctx->location) {
+    case ERTS_PERSISTENT_TERM_CPY_PLACE_1: goto L_copy_table_place_1;
+    case ERTS_PERSISTENT_TERM_CPY_PLACE_2: goto L_copy_table_place_2;
+    case ERTS_PERSISTENT_TERM_CPY_PLACE_3: goto L_copy_table_place_3;
+    case ERTS_PERSISTENT_TERM_CPY_PLACE_START:
+        ctx->iterations_done = 0;
     }
-    return tmp_table;
-}
-
-static HashTable*
-copy_table(HashTable* old_table, Uint new_size, int rehash)
-{
-    HashTable* new_table;
-    Uint old_size = old_table->allocated;
-    Uint i;
-
-    new_table = (HashTable *) erts_alloc(ERTS_ALC_T_PERSISTENT_TERM,
-                                         sizeof(HashTable) +
-                                         sizeof(Eterm) * (new_size-1));
-    if (old_table->allocated == new_size && !rehash) {
+    if (ctx->copy_type == ERTS_PERSISTENT_TERM_CPY_TEMP) {
+        alloc_type = ERTS_ALC_T_PERSISTENT_TERM_TMP;
+    } else {
+        alloc_type = ERTS_ALC_T_PERSISTENT_TERM;
+    }
+    ctx->new_table = (HashTable *) erts_alloc(alloc_type,
+                                              sizeof(HashTable) +
+                                              sizeof(Eterm) * (ctx->new_size-1));
+    if (ctx->old_table->allocated == ctx->new_size &&
+        (ctx->copy_type == ERTS_PERSISTENT_TERM_CPY_NO_REHASH ||
+         ctx->copy_type == ERTS_PERSISTENT_TERM_CPY_TEMP)) {
         /*
          * Same size and no key deleted. Make an exact copy of the table.
          */
-        *new_table = *old_table;
-        for (i = 0; i < new_size; i++) {
-            new_table->term[i] = old_table->term[i];
+        *ctx->new_table = *ctx->old_table;
+    L_copy_table_place_1:
+        for (i = ctx->iterations_done;
+             i < MIN(ctx->iterations_done + ctx->max_iterations,
+                     ctx->new_size);
+             i++) {
+            ctx->new_table->term[i] = ctx->old_table->term[i];
         }
+        ctx->total_iterations_done = (i - ctx->iterations_done);
+        if (i < ctx->new_size) {
+            ctx->iterations_done = i;
+            ctx->location = ERTS_PERSISTENT_TERM_CPY_PLACE_1;
+            return NULL;
+        }
+        ctx->iterations_done = 0;
     } else {
         /*
          * The size of the table has changed or an element has been
          * deleted. Must rehash, by inserting all old terms into the
          * new (empty) table.
          */
-        new_table->allocated = new_size;
-        new_table->num_entries = old_table->num_entries;
-        new_table->mask = new_size - 1;
-        for (i = 0; i < new_size; i++) {
-            new_table->term[i] = NIL;
+        ctx->new_table->allocated = ctx->new_size;
+        ctx->new_table->num_entries = ctx->old_table->num_entries;
+        ctx->new_table->mask = ctx->new_size - 1;
+    L_copy_table_place_2:
+        for (i = ctx->iterations_done;
+             i < MIN(ctx->iterations_done + ctx->max_iterations,
+                     ctx->new_size);
+             i++) {
+            ctx->new_table->term[i] = NIL;
+        }
+        ctx->total_iterations_done = (i - ctx->iterations_done);
+        ctx->max_iterations -= ctx->total_iterations_done;
+        if (i < ctx->new_size) {
+            ctx->iterations_done = i;
+            ctx->location = ERTS_PERSISTENT_TERM_CPY_PLACE_2;
+            return NULL;
         }
-        for (i = 0; i < old_size; i++) {
-            if (is_tuple(old_table->term[i])) {
-                Eterm key = tuple_val(old_table->term[i])[1];
-                Uint entry_index = lookup(new_table, key);
-                ASSERT(is_nil(new_table->term[entry_index]));
-                new_table->term[entry_index] = old_table->term[i];
+        ctx->iterations_done = 0;
+    L_copy_table_place_3:
+        for (i = ctx->iterations_done;
+             i < MIN(ctx->iterations_done + ctx->max_iterations,
+                     old_size);
+             i++) {
+            if (is_tuple(ctx->old_table->term[i])) {
+                Eterm key = tuple_val(ctx->old_table->term[i])[1];
+                Uint entry_index = lookup(ctx->new_table, key);
+                ASSERT(is_nil(ctx->new_table->term[entry_index]));
+                ctx->new_table->term[entry_index] = ctx->old_table->term[i];
             }
         }
+        ctx->total_iterations_done += (i - ctx->iterations_done);
+        if (i < old_size) {
+            ctx->iterations_done = i;
+            ctx->location = ERTS_PERSISTENT_TERM_CPY_PLACE_3;
+            return NULL;
+        }
+        ctx->iterations_done = 0;
+    }
+    ctx->new_table->first_to_delete = 0;
+    ctx->new_table->num_to_delete = 0;
+    erts_atomic_init_nob(&ctx->new_table->refc, (erts_aint_t)1);
+    {
+        HashTable* new_table = ctx->new_table;
+        /*
+         * IMPORTANT: Memory management depends on that ctx->new_table is
+         * set to NULL on the line below
+         */
+        ctx->new_table = NULL;
+        return new_table;
     }
-    new_table->first_to_delete = 0;
-    new_table->num_to_delete = 0;
-    erts_atomic_init_nob(&new_table->refc, (erts_aint_t)1);
-    return new_table;
 }
 
 static void
@@ -981,3 +1234,102 @@ next_to_delete(void)
     erts_mtx_unlock(&delete_queue_mtx);
     return table;
 }
+
+/*
+ * test/debug functionality follow...
+ */
+
+static Uint accessed_literal_areas_size;
+static Uint accessed_no_literal_areas;
+static ErtsLiteralArea **accessed_literal_areas;
+
+int
+erts_debug_have_accessed_literal_area(ErtsLiteralArea *lap)
+{
+    Uint i;
+    for (i = 0; i < accessed_no_literal_areas; i++) {
+        if (accessed_literal_areas[i] == lap)
+            return !0;
+    }
+    return 0;
+}
+
+void
+erts_debug_save_accessed_literal_area(ErtsLiteralArea *lap)
+{
+    if (accessed_no_literal_areas == accessed_literal_areas_size) {
+        accessed_literal_areas_size += 10;
+        accessed_literal_areas = erts_realloc(ERTS_ALC_T_TMP,
+                                              accessed_literal_areas,
+                                              (sizeof(ErtsLiteralArea *)
+                                               *accessed_literal_areas_size));
+    }
+    accessed_literal_areas[accessed_no_literal_areas++] = lap;
+}
+
+static void debug_foreach_off_heap(HashTable *tbl, void (*func)(ErlOffHeap *, void *), void *arg)
+{
+    int i;
+    
+    for (i = 0; i < tbl->allocated; i++) {
+        Eterm term = tbl->term[i];
+        if (is_tuple_arity(term, 2)) {
+            ErtsLiteralArea *lap = term_to_area(term);
+            ErlOffHeap oh;
+            if (!erts_debug_have_accessed_literal_area(lap)) {
+                ERTS_INIT_OFF_HEAP(&oh);
+                oh.first = lap->off_heap;
+                (*func)(&oh, arg);
+                erts_debug_save_accessed_literal_area(lap);
+            }
+        }
+    }
+}
+
+struct debug_la_oh {
+    void (*func)(ErlOffHeap *, void *);
+    void *arg;
+};
+
+static void debug_handle_table(void *vfap,
+                               ErtsThrPrgrVal val,
+                               void *vtbl)
+{
+    struct debug_la_oh *fap = vfap;
+    HashTable *tbl = vtbl;
+    debug_foreach_off_heap(tbl, fap->func, fap->arg);
+}
+
+void
+erts_debug_foreach_persistent_term_off_heap(void (*func)(ErlOffHeap *, void *), void *arg)
+{
+    HashTable *tbl;
+    struct debug_la_oh fa;
+    accessed_no_literal_areas = 0;
+    accessed_literal_areas_size = 10;
+    accessed_literal_areas = erts_alloc(ERTS_ALC_T_TMP,
+                                        (sizeof(ErtsLiteralArea *)
+                                         * accessed_literal_areas_size));
+    
+    tbl = (HashTable *) erts_atomic_read_nob(&the_hash_table);
+    debug_foreach_off_heap(tbl, func, arg);
+    erts_mtx_lock(&delete_queue_mtx);
+    for (tbl = delete_queue_head; tbl; tbl = tbl->delete_next)
+        debug_foreach_off_heap(tbl, func, arg);
+    erts_mtx_unlock(&delete_queue_mtx);
+    fa.func = func;
+    fa.arg = arg;
+    erts_debug_later_op_foreach(table_updater,
+                                debug_handle_table,
+                                (void *) &fa);
+    erts_debug_later_op_foreach(table_deleter,
+                                debug_handle_table,
+                                (void *) &fa);
+    erts_debug_foreach_release_literal_area_off_heap(func, arg);
+    
+    erts_free(ERTS_ALC_T_TMP, accessed_literal_areas);
+    accessed_no_literal_areas = 0;
+    accessed_literal_areas_size = 0;
+    accessed_literal_areas = NULL;
+}
+
diff --git a/erts/emulator/beam/erl_bif_port.c b/erts/emulator/beam/erl_bif_port.c
index 7fe4e02782..ed825d3dda 100644
--- a/erts/emulator/beam/erl_bif_port.c
+++ b/erts/emulator/beam/erl_bif_port.c
@@ -891,10 +891,6 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_typep, int *err_nump)
 
 	    driver = &spawn_driver;
 	} else if (*tp == am_fd) { /* An fd port */
-	    int n;
-	    struct Sint_buf sbuf;
-	    char* p;
-
 	    if (arity != make_arityval(3)) {
 		goto badarg;
 	    }
@@ -904,15 +900,9 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_typep, int *err_nump)
 	    opts.ifd = unsigned_val(tp[1]);
 	    opts.ofd = unsigned_val(tp[2]);
 
-	    /* Syntesize name from input and output descriptor. */
-	    name_buf = erts_alloc(ERTS_ALC_T_TMP,
-				  2*sizeof(struct Sint_buf) + 2); 
-	    p = Sint_to_buf(opts.ifd, &sbuf);
-	    n = sys_strlen(p);
-	    sys_strncpy(name_buf, p, n);
-	    name_buf[n] = '/';
-	    p = Sint_to_buf(opts.ofd, &sbuf);
-	    sys_strcpy(name_buf+n+1, p);
+            /* Syntesize name from input and output descriptor. */
+            name_buf = erts_alloc(ERTS_ALC_T_TMP, 256);
+            erts_snprintf(name_buf, 256, "%i/%i", opts.ifd, opts.ofd);
 
 	    driver = &fd_driver;
 	} else {
diff --git a/erts/emulator/beam/erl_bif_re.c b/erts/emulator/beam/erl_bif_re.c
index bbc64eb9aa..b3bf1c7ee3 100644
--- a/erts/emulator/beam/erl_bif_re.c
+++ b/erts/emulator/beam/erl_bif_re.c
@@ -46,7 +46,7 @@ static Export *urun_trap_exportp = NULL;
 static Export *ucompile_trap_exportp = NULL;
 
 static BIF_RETTYPE re_exec_trap(BIF_ALIST_3);
-static BIF_RETTYPE re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3);
+static BIF_RETTYPE re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3, int first);
 
 static void *erts_erts_pcre_malloc(size_t size) {
     return erts_alloc(ERTS_ALC_T_RE_HEAP,size);
@@ -532,10 +532,7 @@ re_compile(Process* p, Eterm arg1, Eterm arg2)
     int options = 0;
     int pflags = 0;
     int unicode = 0;
-#ifdef DEBUG
     int buffres;
-#endif
-
 
     if (parse_options(arg2,&options,NULL,&pflags,NULL,NULL,NULL,NULL)
 	< 0) {
@@ -556,12 +553,8 @@ re_compile(Process* p, Eterm arg1, Eterm arg2)
         BIF_ERROR(p,BADARG);
     }
     expr = erts_alloc(ERTS_ALC_T_RE_TMP_BUF, slen + 1);
-#ifdef DEBUG
-    buffres =
-#endif
-    erts_iolist_to_buf(arg1, expr, slen);
-
-    ASSERT(buffres >= 0);
+    buffres = erts_iolist_to_buf(arg1, expr, slen);
+    ASSERT(buffres >= 0); (void)buffres;
 
     expr[slen]='\0';
     result = erts_pcre_compile2(expr, options, &errcode, 
@@ -1052,9 +1045,7 @@ build_capture(Eterm capture_spec[CAPSPEC_SIZE], const pcre *code)
 			tmpb[ap->len] = '\0';
 		    } else {
 			ErlDrvSizeT slen;
-#ifdef DEBUG
 			int buffres;
-#endif
 
 			if (erts_iolist_size(val, &slen)) {
 			    goto error;
@@ -1068,11 +1059,8 @@ build_capture(Eterm capture_spec[CAPSPEC_SIZE], const pcre *code)
 			    }
 			}
 
-#ifdef DEBUG
-			buffres =
-#endif
-			erts_iolist_to_buf(val, tmpb, slen);
-			ASSERT(buffres >= 0);
+			buffres = erts_iolist_to_buf(val, tmpb, slen);
+			ASSERT(buffres >= 0); (void)buffres;
 			tmpb[slen] = '\0';
 		    }
 		    build_one_capture(code,&ri,&sallocated,has_dupnames,tmpb);
@@ -1106,7 +1094,7 @@ build_capture(Eterm capture_spec[CAPSPEC_SIZE], const pcre *code)
  * The actual re:run/2,3 BIFs
  */
 static BIF_RETTYPE
-re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3)
+re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3, int first)
 {
     const pcre *code_tmp;
     RestartContext restart;
@@ -1132,6 +1120,14 @@ re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3)
 	< 0) {
 	BIF_ERROR(p,BADARG);
     }
+    if (!first) {
+        /*
+         * 'first' is false when re:grun() previously has called re:internal_run()
+         * with the same subject; i.e., no need to do yet another validation of
+         * the subject regarding utf8 encoding...
+         */
+        options |= PCRE_NO_UTF8_CHECK;
+    }
     is_list_cap = ((pflags & PARSE_FLAG_CAPTURE_OPT) && 
 		   (capture[CAPSPEC_TYPE] == am_list));
 
@@ -1145,9 +1141,7 @@ re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3)
 	    const char *errstr = "";
 	    int errofset = 0;
 	    int capture_count;
-#ifdef DEBUG
 	    int buffres;
-#endif
 
 	    if (pflags & PARSE_FLAG_UNICODE && 
 		(!is_binary(arg2) || !is_binary(arg1) ||
@@ -1161,12 +1155,8 @@ re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3)
 	    
 	    expr = erts_alloc(ERTS_ALC_T_RE_TMP_BUF, slen + 1);
 	    
-#ifdef DEBUG
-	    buffres =
-#endif
-	    erts_iolist_to_buf(arg2, expr, slen);
-
-	    ASSERT(buffres >= 0);
+	    buffres = erts_iolist_to_buf(arg2, expr, slen);
+	    ASSERT(buffres >= 0); (void)buffres;
 
 	    expr[slen]='\0';
 	    result = erts_pcre_compile2(expr, comp_options, &errcode, 
@@ -1317,9 +1307,7 @@ re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3)
 	restart.subject = (char *) (pb->bytes+offset);
 	restart.flags |= RESTART_FLAG_SUBJECT_IN_BINARY;
     } else {
-#ifdef DEBUG
 	int buffres;
-#endif
 handle_iolist:
 	if (erts_iolist_size(arg1, &slength)) {
 	    erts_free(ERTS_ALC_T_RE_SUBJECT, restart.ovector);
@@ -1331,11 +1319,8 @@ handle_iolist:
 	}
 	restart.subject = erts_alloc(ERTS_ALC_T_RE_SUBJECT, slength);
 
-#ifdef DEBUG
-	buffres =
-#endif
-	erts_iolist_to_buf(arg1, restart.subject, slength);
-	ASSERT(buffres >= 0);
+	buffres = erts_iolist_to_buf(arg1, restart.subject, slength);
+	ASSERT(buffres >= 0); (void)buffres;
     }
 
     if (pflags & PARSE_FLAG_REPORT_ERRORS) {
@@ -1383,15 +1368,28 @@ handle_iolist:
 }
 
 BIF_RETTYPE
+re_internal_run_4(BIF_ALIST_4)
+{
+    int first;
+    if (BIF_ARG_4 == am_false)
+        first = 0;
+    else if (BIF_ARG_4 == am_true)
+        first = !0;
+    else
+        BIF_ERROR(BIF_P,BADARG);
+    return re_run(BIF_P,BIF_ARG_1, BIF_ARG_2, BIF_ARG_3, first);
+}
+
+BIF_RETTYPE
 re_run_3(BIF_ALIST_3)
 {
-    return re_run(BIF_P,BIF_ARG_1, BIF_ARG_2, BIF_ARG_3);
+    return re_run(BIF_P,BIF_ARG_1, BIF_ARG_2, BIF_ARG_3, !0);
 }
 
 BIF_RETTYPE
 re_run_2(BIF_ALIST_2) 
 {
-    return re_run(BIF_P,BIF_ARG_1, BIF_ARG_2, NIL);
+    return re_run(BIF_P,BIF_ARG_1, BIF_ARG_2, NIL, !0);
 }
 
 /*
@@ -1430,6 +1428,7 @@ static BIF_RETTYPE re_exec_trap(BIF_ALIST_3)
     loop_count = 0xFFFFFFFF;
 #endif
     rc = erts_pcre_exec(NULL, &(restartp->extra), NULL, 0, 0, 0, NULL, 0);
+
     ASSERT(loop_count != 0xFFFFFFFF);
     BUMP_REDS(BIF_P, loop_count / LOOP_FACTOR);
     if (rc == PCRE_ERROR_LOOP_LIMIT) {
@@ -1457,10 +1456,7 @@ re_inspect_2(BIF_ALIST_2)
     Eterm res;
     const pcre *code;
     byte *temp_alloc = NULL;
-#ifdef DEBUG
-    int infores;
-#endif
-    
+    int infores;    
 
     if (is_not_tuple(BIF_ARG_1) || (arityval(*tuple_val(BIF_ARG_1)) != 5)) {
 	goto error;
@@ -1484,12 +1480,8 @@ re_inspect_2(BIF_ALIST_2)
     if (erts_pcre_fullinfo(code, NULL, PCRE_INFO_OPTIONS, &options) != 0)
 	goto error;
 
-#ifdef DEBUG
-    infores =
-#endif
-    erts_pcre_fullinfo(code, NULL, PCRE_INFO_NAMECOUNT, &top);
-
-    ASSERT(infores == 0);
+    infores = erts_pcre_fullinfo(code, NULL, PCRE_INFO_NAMECOUNT, &top);
+    ASSERT(infores == 0); (void)infores;
 
     if (top <= 0) {
 	hp = HAlloc(BIF_P, 3);
@@ -1497,18 +1489,10 @@ re_inspect_2(BIF_ALIST_2)
 	erts_free_aligned_binary_bytes(temp_alloc);
 	BIF_RET(res);
     }
-#ifdef DEBUG
-    infores =
-#endif
-    erts_pcre_fullinfo(code, NULL, PCRE_INFO_NAMEENTRYSIZE, &entrysize);
-
+    infores = erts_pcre_fullinfo(code, NULL, PCRE_INFO_NAMEENTRYSIZE, &entrysize);
     ASSERT(infores == 0);
 
-#ifdef DEBUG
-    infores =
-#endif
-    erts_pcre_fullinfo(code, NULL, PCRE_INFO_NAMETABLE, &nametable);
-
+    infores = erts_pcre_fullinfo(code, NULL, PCRE_INFO_NAMETABLE, &nametable);
     ASSERT(infores == 0);
     
     has_dupnames = ((options & PCRE_DUPNAMES) != 0);
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index 711e62c795..b31d5b86cb 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -74,7 +74,7 @@ static void smp_bp_finisher(void* arg);
 static BIF_RETTYPE
 system_monitor(Process *p, Eterm monitor_pid, Eterm list);
 
-static void new_seq_trace_token(Process* p); /* help func for seq_trace_2*/
+static void new_seq_trace_token(Process* p, int); /* help func for seq_trace_2*/
 static Eterm trace_info_pid(Process* p, Eterm pid_spec, Eterm key);
 static Eterm trace_info_func(Process* p, Eterm pid_spec, Eterm key);
 static Eterm trace_info_on_load(Process* p, Eterm key);
@@ -1874,7 +1874,7 @@ Eterm erts_seq_trace(Process *p, Eterm arg1, Eterm arg2,
 
     if (current_flag && ( (arg2 == am_true) || (arg2 == am_false)) ) {
 	/* Flags */
-        new_seq_trace_token(p);
+        new_seq_trace_token(p, 0);
         flags = unsigned_val(SEQ_TRACE_TOKEN_FLAGS(p));
 	if (build_result) {
 	    old_value = flags & current_flag ? am_true : am_false;
@@ -1889,11 +1889,11 @@ Eterm erts_seq_trace(Process *p, Eterm arg1, Eterm arg2,
 	return old_value;
     }
     else if (arg1 == am_label) {
-        new_seq_trace_token(p);
+        new_seq_trace_token(p, is_not_immed(arg2));
 	if (build_result) {
 	    old_value = SEQ_TRACE_TOKEN_LABEL(p);
 	}
-	SEQ_TRACE_TOKEN_LABEL(p) = arg2;
+        SEQ_TRACE_TOKEN_LABEL(p) = arg2;
     	return old_value;
     }
     else if (arg1 == am_serial) {
@@ -1905,7 +1905,7 @@ Eterm erts_seq_trace(Process *p, Eterm arg1, Eterm arg2,
 	if ((*tp != make_arityval(2)) || is_not_small(*(tp+1)) || is_not_small(*(tp+2))) {
 	    return THE_NON_VALUE;
         }
-        new_seq_trace_token(p);
+        new_seq_trace_token(p, 0);
 	if (build_result) {
 	    hp = HAlloc(p,3);
 	    old_value = TUPLE2(hp, SEQ_TRACE_TOKEN_LASTCNT(p),
@@ -1940,8 +1940,8 @@ Eterm erts_seq_trace(Process *p, Eterm arg1, Eterm arg2,
     }
 }
 
-void
-new_seq_trace_token(Process* p)
+static void
+new_seq_trace_token(Process* p, int ensure_new_heap)
 {
     Eterm* hp;
 
@@ -1953,6 +1953,16 @@ new_seq_trace_token(Process* p)
 				    p->common.id, /* Internal pid */	/* From   */
 				    make_small(p->seq_trace_lastcnt));
     }
+    else if (ensure_new_heap) {
+        Eterm* tpl = tuple_val(SEQ_TRACE_TOKEN(p));
+        ASSERT(arityval(tpl[0]) == 5);
+        if (ErtsInArea(tpl, OLD_HEAP(p),
+                       (OLD_HEND(p) - OLD_HEAP(p))*sizeof(Eterm))) {
+            hp = HAlloc(p, 6);
+            sys_memcpy(hp, tpl, 6*sizeof(Eterm));
+            SEQ_TRACE_TOKEN(p) = make_tuple(hp);
+        }
+    }
 }
 
 BIF_RETTYPE erl_seq_trace_info(Process *p, Eterm item)
@@ -2050,10 +2060,7 @@ BIF_RETTYPE seq_trace_print_2(BIF_ALIST_2)
     if (have_no_seqtrace(SEQ_TRACE_TOKEN(BIF_P))) {
 	BIF_RET(am_false);
     }
-    if (!(is_atom(BIF_ARG_1) || is_small(BIF_ARG_1))) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
-    if (SEQ_TRACE_TOKEN_LABEL(BIF_P) != BIF_ARG_1)
+    if (!EQ(BIF_ARG_1, SEQ_TRACE_TOKEN_LABEL(BIF_P)))
 	BIF_RET(am_false);
     seq_trace_update_send(BIF_P);
     seq_trace_output(SEQ_TRACE_TOKEN(BIF_P), BIF_ARG_2, 
diff --git a/erts/emulator/beam/erl_binary.h b/erts/emulator/beam/erl_binary.h
index 08edb43c49..66b59ef1a3 100644
--- a/erts/emulator/beam/erl_binary.h
+++ b/erts/emulator/beam/erl_binary.h
@@ -278,7 +278,6 @@ Eterm erts_bin_bytes_to_list(Eterm previous, Eterm* hp, byte* bytes, Uint size,
  */
 
 BIF_RETTYPE erts_list_to_binary_bif(Process *p, Eterm arg, Export *bif);
-BIF_RETTYPE erts_gc_binary_part(Process *p, Eterm *reg, Eterm live, int range_is_tuple);
 BIF_RETTYPE erts_binary_part(Process *p, Eterm binary, Eterm epos, Eterm elen);
 
 
@@ -315,6 +314,7 @@ ERTS_GLB_INLINE Binary *erts_bin_drv_alloc(Uint size);
 ERTS_GLB_INLINE Binary *erts_bin_nrml_alloc(Uint size);
 ERTS_GLB_INLINE Binary *erts_bin_realloc_fnf(Binary *bp, Uint size);
 ERTS_GLB_INLINE Binary *erts_bin_realloc(Binary *bp, Uint size);
+ERTS_GLB_INLINE void erts_magic_binary_free(Binary *bp);
 ERTS_GLB_INLINE void erts_bin_free(Binary *bp);
 ERTS_GLB_INLINE void erts_bin_release(Binary *bp);
 ERTS_GLB_INLINE Binary *erts_create_magic_binary_x(Uint size,
@@ -351,6 +351,19 @@ erts_free_aligned_binary_bytes(byte* buf)
     erts_free_aligned_binary_bytes_extra(buf,ERTS_ALC_T_TMP);
 }
 
+/* A binary's size in bits must fit into a word for matching to work. We used
+ * to allow creating larger binaries than this, but they acted really strangely
+ * in Erlang code and were pretty much only usable in drivers and NIFs.
+ *
+ * This check also ensures, indirectly, that there won't be an overflow when
+ * the size is bumped by CHICKEN_PAD and the binary struct itself. */
+#define BINARY_OVERFLOW_CHECK(BYTE_SIZE) \
+    do { \
+         if (ERTS_UNLIKELY(BYTE_SIZE > ERTS_UWORD_MAX / CHAR_BIT)) { \
+             return NULL; \
+         } \
+    } while(0)
+
 /* Explicit extra bytes allocated to counter buggy drivers.
 ** These extra bytes where earlier (< R13B04) added by an alignment-bug
 ** in this code. Do we dare remove this in some major release (R14?) maybe?
@@ -364,86 +377,114 @@ erts_free_aligned_binary_bytes(byte* buf)
 ERTS_GLB_INLINE Binary *
 erts_bin_drv_alloc_fnf(Uint size)
 {
-    Uint bsize = ERTS_SIZEOF_Binary(size) + CHICKEN_PAD;
     Binary *res;
+    Uint bsize;
+
+    BINARY_OVERFLOW_CHECK(size);
+    bsize = ERTS_SIZEOF_Binary(size) + CHICKEN_PAD;
 
-    if (bsize < size) /* overflow */
-	return NULL;
     res = erts_alloc_fnf(ERTS_ALC_T_DRV_BINARY, bsize);
     ERTS_CHK_BIN_ALIGNMENT(res);
+
     if (res) {
-	res->orig_size = size;
-	res->intern.flags = BIN_FLAG_DRV;
+        res->orig_size = size;
+        res->intern.flags = BIN_FLAG_DRV;
         erts_refc_init(&res->intern.refc, 1);
     }
+
     return res;
 }
 
 ERTS_GLB_INLINE Binary *
 erts_bin_drv_alloc(Uint size)
 {
-    Uint bsize = ERTS_SIZEOF_Binary(size) + CHICKEN_PAD;
+    Binary *res = erts_bin_drv_alloc_fnf(size);
+
+    if (res) {
+        return res;
+    }
+
+    erts_alloc_enomem(ERTS_ALC_T_DRV_BINARY, size);
+}
+
+ERTS_GLB_INLINE Binary *
+erts_bin_nrml_alloc_fnf(Uint size)
+{
     Binary *res;
+    Uint bsize;
+
+    BINARY_OVERFLOW_CHECK(size);
+    bsize = ERTS_SIZEOF_Binary(size) + CHICKEN_PAD;
 
-    if (bsize < size) /* overflow */
-	erts_alloc_enomem(ERTS_ALC_T_DRV_BINARY, size);
-    res = erts_alloc(ERTS_ALC_T_DRV_BINARY, bsize);
+    res = erts_alloc_fnf(ERTS_ALC_T_BINARY, bsize);
     ERTS_CHK_BIN_ALIGNMENT(res);
-    res->orig_size = size;
-    res->intern.flags = BIN_FLAG_DRV;
-    erts_refc_init(&res->intern.refc, 1);
+
+    if (res) {
+        res->orig_size = size;
+        res->intern.flags = 0;
+        erts_refc_init(&res->intern.refc, 1);
+    }
+
     return res;
 }
 
 ERTS_GLB_INLINE Binary *
 erts_bin_nrml_alloc(Uint size)
 {
-    Uint bsize = ERTS_SIZEOF_Binary(size) + CHICKEN_PAD;
-    Binary *res;
+    Binary *res = erts_bin_drv_alloc_fnf(size);
 
-    if (bsize < size) /* overflow */
-	erts_alloc_enomem(ERTS_ALC_T_BINARY, size);
-    res = erts_alloc(ERTS_ALC_T_BINARY, bsize);
-    ERTS_CHK_BIN_ALIGNMENT(res);
-    res->orig_size = size;
-    res->intern.flags = 0;
-    erts_refc_init(&res->intern.refc, 1);
-    return res;
+    if (res) {
+        return res;
+    }
+
+    erts_alloc_enomem(ERTS_ALC_T_BINARY, size);
 }
 
 ERTS_GLB_INLINE Binary *
 erts_bin_realloc_fnf(Binary *bp, Uint size)
 {
+    ErtsAlcType_t type;
     Binary *nbp;
-    Uint bsize = ERTS_SIZEOF_Binary(size) + CHICKEN_PAD;
-    ErtsAlcType_t type = (bp->intern.flags & BIN_FLAG_DRV) ? ERTS_ALC_T_DRV_BINARY
-	                                            : ERTS_ALC_T_BINARY;
+    Uint bsize;
+    
+    type = (bp->intern.flags & BIN_FLAG_DRV) ? ERTS_ALC_T_DRV_BINARY
+                                             : ERTS_ALC_T_BINARY;
     ASSERT((bp->intern.flags & BIN_FLAG_MAGIC) == 0);
-    if (bsize < size) /* overflow */
-	return NULL;
+
+    BINARY_OVERFLOW_CHECK(size);
+    bsize = ERTS_SIZEOF_Binary(size) + CHICKEN_PAD;
+
     nbp = erts_realloc_fnf(type, (void *) bp, bsize);
     ERTS_CHK_BIN_ALIGNMENT(nbp);
-    if (nbp)
-	nbp->orig_size = size;
+
+    if (nbp) {
+        nbp->orig_size = size;
+    }
+
     return nbp;
 }
 
 ERTS_GLB_INLINE Binary *
 erts_bin_realloc(Binary *bp, Uint size)
 {
-    Binary *nbp;
-    Uint bsize = ERTS_SIZEOF_Binary(size) + CHICKEN_PAD;
-    ErtsAlcType_t type = (bp->intern.flags & BIN_FLAG_DRV) ? ERTS_ALC_T_DRV_BINARY
-	                                            : ERTS_ALC_T_BINARY;
-    ASSERT((bp->intern.flags & BIN_FLAG_MAGIC) == 0);
-    if (bsize < size) /* overflow */
-	erts_realloc_enomem(type, bp, size);
-    nbp = erts_realloc_fnf(type, (void *) bp, bsize);
-    if (!nbp)
-	erts_realloc_enomem(type, bp, bsize);
-    ERTS_CHK_BIN_ALIGNMENT(nbp);
-    nbp->orig_size = size;
-    return nbp;
+    Binary *nbp = erts_bin_realloc_fnf(bp, size);
+
+    if (nbp) {
+        return nbp;
+    }
+
+    if (bp->intern.flags & BIN_FLAG_DRV) {
+        erts_realloc_enomem(ERTS_ALC_T_DRV_BINARY, bp, size);
+    } else {
+        erts_realloc_enomem(ERTS_ALC_T_BINARY, bp, size);
+    }
+}
+
+ERTS_GLB_INLINE void
+erts_magic_binary_free(Binary *bp)
+{
+    erts_magic_ref_remove_bin(ERTS_MAGIC_BIN_REFN(bp));
+    erts_free(ERTS_MAGIC_BIN_ATYPE(bp), (void *) bp);
 }
 
 ERTS_GLB_INLINE void
@@ -454,8 +495,7 @@ erts_bin_free(Binary *bp)
             /* Destructor took control of the deallocation */
             return;
         }
-	erts_magic_ref_remove_bin(ERTS_MAGIC_BIN_REFN(bp));
-        erts_free(ERTS_MAGIC_BIN_ATYPE(bp), (void *) bp);
+        erts_magic_binary_free(bp);
     }
     else if (bp->intern.flags & BIN_FLAG_DRV)
 	erts_free(ERTS_ALC_T_DRV_BINARY, (void *) bp);
diff --git a/erts/emulator/beam/erl_bits.c b/erts/emulator/beam/erl_bits.c
index 3a16913473..a0edbc81a4 100644
--- a/erts/emulator/beam/erl_bits.c
+++ b/erts/emulator/beam/erl_bits.c
@@ -124,10 +124,10 @@ erts_bs_start_match_2(Process *p, Eterm Binary, Uint Max)
     ProcBin* pb;
 
     ASSERT(is_binary(Binary));
+
     total_bin_size = binary_size(Binary);
-    if ((total_bin_size >> (8*sizeof(Uint)-3)) != 0) {
-	return THE_NON_VALUE;
-    }
+    ASSERT(total_bin_size <= ERTS_UWORD_MAX / CHAR_BIT);
+
     NeededSize = ERL_BIN_MATCHSTATE_SIZE(Max);
     hp = HeapOnlyAlloc(p, NeededSize);
     ms = (ErlBinMatchState *) hp;
@@ -144,6 +144,41 @@ erts_bs_start_match_2(Process *p, Eterm Binary, Uint Max)
     return make_matchstate(ms);
 }
 
+ErlBinMatchState *erts_bs_start_match_3(Process *p, Eterm Binary)
+{
+    Eterm Orig;
+    Uint offs;
+    Uint* hp;
+    Uint NeededSize;
+    ErlBinMatchState *ms;
+    Uint bitoffs;
+    Uint bitsize;
+    Uint total_bin_size;
+    ProcBin* pb;
+
+    ASSERT(is_binary(Binary));
+
+    total_bin_size = binary_size(Binary);
+    ASSERT(total_bin_size <= ERTS_UWORD_MAX / CHAR_BIT);
+
+    NeededSize = ERL_BIN_MATCHSTATE_SIZE(0);
+    hp = HeapOnlyAlloc(p, NeededSize);
+    ms = (ErlBinMatchState *) hp;
+    ERTS_GET_REAL_BIN(Binary, Orig, offs, bitoffs, bitsize);
+    pb = (ProcBin *) boxed_val(Orig);
+    if (pb->thing_word == HEADER_PROC_BIN && pb->flags != 0) {
+        erts_emasculate_writable_binary(pb);
+    }
+
+    ms->thing_word = HEADER_BIN_MATCHSTATE(0);
+    (ms->mb).orig = Orig;
+    (ms->mb).base = binary_bytes(Orig);
+    (ms->mb).offset = 8 * offs + bitoffs;
+    (ms->mb).size = total_bin_size * 8 + (ms->mb).offset + bitsize;
+
+    return ms;
+}
+
 #ifdef DEBUG
 # define CHECK_MATCH_BUFFER(MB) check_match_buffer(MB)
 
@@ -423,29 +458,25 @@ erts_bs_get_integer_2(Process *p, Uint num_bits, unsigned flags, ErlBinMatchBuff
 Eterm
 erts_bs_get_binary_2(Process *p, Uint num_bits, unsigned flags, ErlBinMatchBuffer* mb)
 {
-    ErlSubBin* sb;
+    Eterm result;
 
     CHECK_MATCH_BUFFER(mb);
-    if (mb->size - mb->offset < num_bits) {	/* Asked for too many bits.  */
-	return THE_NON_VALUE;
+    if (mb->size - mb->offset < num_bits) {
+        /* Asked for too many bits.  */
+        return THE_NON_VALUE;
     }
 
     /*
      * From now on, we can't fail.
      */
 
-    sb = (ErlSubBin *) HeapOnlyAlloc(p, ERL_SUB_BIN_SIZE);
-    
-    sb->thing_word = HEADER_SUB_BIN;
-    sb->orig = mb->orig;
-    sb->size = BYTE_OFFSET(num_bits);
-    sb->bitsize = BIT_OFFSET(num_bits);
-    sb->offs = BYTE_OFFSET(mb->offset);
-    sb->bitoffs = BIT_OFFSET(mb->offset);
-    sb->is_writable = 0;
+    result = erts_extract_sub_binary(&HEAP_TOP(p),
+                                     mb->orig, mb->base,
+                                     mb->offset, num_bits);
+
     mb->offset += num_bits;
-    
-    return make_binary(sb);
+
+    return result;
 }
 
 Eterm
@@ -509,21 +540,19 @@ erts_bs_get_float_2(Process *p, Uint num_bits, unsigned flags, ErlBinMatchBuffer
 Eterm
 erts_bs_get_binary_all_2(Process *p, ErlBinMatchBuffer* mb)
 {
-    ErlSubBin* sb;
-    Uint size;
+    Uint bit_size;
+    Eterm result;
 
     CHECK_MATCH_BUFFER(mb);
-    size =  mb->size-mb->offset;
-    sb = (ErlSubBin *) HeapOnlyAlloc(p, ERL_SUB_BIN_SIZE);
-    sb->thing_word = HEADER_SUB_BIN;
-    sb->size = BYTE_OFFSET(size);
-    sb->bitsize = BIT_OFFSET(size);
-    sb->offs = BYTE_OFFSET(mb->offset);
-    sb->bitoffs = BIT_OFFSET(mb->offset);
-    sb->is_writable = 0;
-    sb->orig = mb->orig;
-    mb->offset = mb->size;  
-    return make_binary(sb);
+    bit_size = mb->size - mb->offset;
+
+    result = erts_extract_sub_binary(&HEAP_TOP(p),
+                                     mb->orig, mb->base,
+                                     mb->offset, bit_size);
+
+    mb->offset = mb->size;
+
+    return result;
 }
 
 /****************************************************************
@@ -1295,6 +1324,14 @@ erts_bs_append(Process* c_p, Eterm* reg, Uint live, Eterm build_size_term,
 	}
     }
 
+    if (build_size_in_bits == 0) {
+        if (c_p->stop - c_p->htop < extra_words) {
+            (void) erts_garbage_collect(c_p, extra_words, reg, live+1);
+            bin = reg[live];
+        }
+	return bin;
+    }
+
     if((ERTS_UINT_MAX - build_size_in_bits) < erts_bin_offset) {
         c_p->freason = SYSTEM_LIMIT;
         return THE_NON_VALUE;
@@ -1352,13 +1389,13 @@ erts_bs_append(Process* c_p, Eterm* reg, Uint live, Eterm build_size_term,
 	Uint bitsize;
 	Eterm* hp;
 
-	/*
+        /*
 	 * Allocate heap space.
 	 */
 	heap_need = PROC_BIN_SIZE + ERL_SUB_BIN_SIZE + extra_words;
 	if (c_p->stop - c_p->htop < heap_need) {
 	    (void) erts_garbage_collect(c_p, heap_need, reg, live+1);
-	    bin = reg[live];
+            bin = reg[live];
 	}
 	hp = c_p->htop;
 
@@ -1376,6 +1413,10 @@ erts_bs_append(Process* c_p, Eterm* reg, Uint live, Eterm build_size_term,
 	    }
 	}
 
+	if (build_size_in_bits == 0) {
+            return bin;
+	}
+
         if((ERTS_UINT_MAX - build_size_in_bits) < erts_bin_offset) {
             c_p->freason = SYSTEM_LIMIT;
             return THE_NON_VALUE;
@@ -2049,3 +2090,39 @@ erts_copy_bits(byte* src,	/* Base pointer to source. */
     }
 }
 
+Eterm erts_extract_sub_binary(Eterm **hp, Eterm base_bin, byte *base_data,
+                              Uint bit_offset, Uint bit_size)
+{
+    Uint byte_offset, byte_size;
+
+    ERTS_CT_ASSERT(ERL_SUB_BIN_SIZE <= ERL_ONHEAP_BIN_LIMIT);
+
+    byte_offset = BYTE_OFFSET(bit_offset);
+    byte_size = BYTE_OFFSET(bit_size);
+
+    if (BIT_OFFSET(bit_size) == 0 && byte_size <= ERL_ONHEAP_BIN_LIMIT) {
+        ErlHeapBin *hb = (ErlHeapBin*)*hp;
+        *hp += heap_bin_size(byte_size);
+
+        hb->thing_word = header_heap_bin(byte_size);
+        hb->size = byte_size;
+
+        copy_binary_to_buffer(hb->data, 0, base_data, bit_offset, bit_size);
+
+        return make_binary(hb);
+    } else {
+        ErlSubBin *sb = (ErlSubBin*)*hp;
+        *hp += ERL_SUB_BIN_SIZE;
+
+        sb->thing_word = HEADER_SUB_BIN;
+        sb->size = byte_size;
+        sb->offs = byte_offset;
+        sb->orig = base_bin;
+        sb->bitoffs = BIT_OFFSET(bit_offset);
+        sb->bitsize = BIT_OFFSET(bit_size);
+        sb->is_writable = 0;
+
+        return make_binary(sb);
+    }
+}
+
diff --git a/erts/emulator/beam/erl_bits.h b/erts/emulator/beam/erl_bits.h
index 7beef5cfda..0b2a6f3760 100644
--- a/erts/emulator/beam/erl_bits.h
+++ b/erts/emulator/beam/erl_bits.h
@@ -73,12 +73,16 @@ struct erl_bits_state {
 typedef struct erl_bin_match_struct{
   Eterm thing_word;
   ErlBinMatchBuffer mb;		/* Present match buffer */
-  Eterm save_offset[1];		/* Saved offsets */
+  Eterm save_offset[1];         /* Saved offsets, only valid for contexts
+                                 * created through bs_start_match2. */
 } ErlBinMatchState;
 
-#define ERL_BIN_MATCHSTATE_SIZE(_Max) ((sizeof(ErlBinMatchState) + (_Max)*sizeof(Eterm))/sizeof(Eterm)) 
-#define HEADER_BIN_MATCHSTATE(_Max) _make_header(ERL_BIN_MATCHSTATE_SIZE((_Max))-1, _TAG_HEADER_BIN_MATCHSTATE)
-#define HEADER_NUM_SLOTS(hdr) (header_arity(hdr)-sizeof(ErlBinMatchState)/sizeof(Eterm)+1)
+#define ERL_BIN_MATCHSTATE_SIZE(_Max) \
+    ((offsetof(ErlBinMatchState, save_offset) + (_Max)*sizeof(Eterm))/sizeof(Eterm))
+#define HEADER_BIN_MATCHSTATE(_Max) \
+    _make_header(ERL_BIN_MATCHSTATE_SIZE((_Max)) - 1, _TAG_HEADER_BIN_MATCHSTATE)
+#define HEADER_NUM_SLOTS(hdr) \
+    (header_arity(hdr) - (offsetof(ErlBinMatchState, save_offset) / sizeof(Eterm)) + 1)
 
 #define make_matchstate(_Ms) make_boxed((Eterm*)(_Ms))  
 #define ms_matchbuffer(_Ms) &(((ErlBinMatchState*) boxed_val(_Ms))->mb)
@@ -112,7 +116,7 @@ typedef struct erl_bin_match_struct{
   do {											    \
     if (BIT_OFFSET(DstBufOffset) == 0 && (SrcBufferOffset == 0) &&			    \
         (BIT_OFFSET(NumBits)==0) && (NumBits != 0)) {					    \
-      sys_memcpy(DstBuffer+BYTE_OFFSET(DstBufOffset),					    \
+      sys_memcpy(((byte*)DstBuffer)+BYTE_OFFSET(DstBufOffset),					    \
 		 SrcBuffer, NBYTES(NumBits));						    \
     } else {										    \
       erts_copy_bits(SrcBuffer, SrcBufferOffset, 1,					    \
@@ -144,9 +148,13 @@ void erts_bits_destroy_state(ERL_BITS_PROTO_0);
  */
 
 Eterm erts_bs_start_match_2(Process *p, Eterm Bin, Uint Max);
+ErlBinMatchState *erts_bs_start_match_3(Process *p, Eterm Bin);
 Eterm erts_bs_get_integer_2(Process *p, Uint num_bits, unsigned flags, ErlBinMatchBuffer* mb);
-Eterm erts_bs_get_binary_2(Process *p, Uint num_bits, unsigned flags, ErlBinMatchBuffer* mb);
 Eterm erts_bs_get_float_2(Process *p, Uint num_bits, unsigned flags, ErlBinMatchBuffer* mb);
+
+/* These will create heap binaries when appropriate, so they require free space
+ * up to EXTRACT_SUB_BIN_HEAP_NEED. */
+Eterm erts_bs_get_binary_2(Process *p, Uint num_bits, unsigned flags, ErlBinMatchBuffer* mb);
 Eterm erts_bs_get_binary_all_2(Process *p, ErlBinMatchBuffer* mb);
 
 /*
@@ -177,6 +185,17 @@ void erts_copy_bits(byte* src, size_t soffs, int sdir,
 		    byte* dst, size_t doffs,int ddir, size_t n);        
 int erts_cmp_bits(byte* a_ptr, size_t a_offs, byte* b_ptr, size_t b_offs, size_t size); 
 
+
+/* Extracts a region from base_bin as a sub-binary or heap binary, whichever
+ * is the most appropriate.
+ *
+ * The caller must ensure that there's enough free space at *hp */
+Eterm erts_extract_sub_binary(Eterm **hp, Eterm base_bin, byte *base_data,
+                              Uint bit_offset, Uint num_bits);
+
+/* Pessimistic estimate of the words required for erts_extract_sub_binary */
+#define EXTRACT_SUB_BIN_HEAP_NEED (heap_bin_size(ERL_ONHEAP_BIN_LIMIT))
+
 /*
  * Flags for bs_get_* / bs_put_* / bs_init* instructions.
  */
diff --git a/erts/emulator/beam/erl_cpu_topology.c b/erts/emulator/beam/erl_cpu_topology.c
index 6f8d2f8c35..6a4f43297e 100644
--- a/erts/emulator/beam/erl_cpu_topology.c
+++ b/erts/emulator/beam/erl_cpu_topology.c
@@ -34,6 +34,7 @@
 #include "error.h"
 #include "bif.h"
 #include "erl_cpu_topology.h"
+#include "erl_flxctr.h"
 
 #define ERTS_MAX_READER_GROUPS 64
 
@@ -58,6 +59,7 @@ static erts_cpu_info_t *cpuinfo;
 
 static int max_main_threads;
 static int reader_groups;
+static int decentralized_counter_groups;
 
 static ErtsCpuBindData *scheduler2cpu_map;
 static erts_rwmtx_t cpuinfo_rwmtx;
@@ -127,6 +129,8 @@ static erts_cpu_groups_map_t *cpu_groups_maps;
 
 static erts_cpu_groups_map_t *reader_groups_map;
 
+static erts_cpu_groups_map_t *decentralized_counter_groups_map;
+
 #define ERTS_TOPOLOGY_CG ERTS_TOPOLOGY_MAX_DEPTH
 
 #define ERTS_MAX_CPU_TOPOLOGY_ID ((int) 0xffff)
@@ -138,6 +142,7 @@ static void cpu_bind_order_sort(erts_cpu_topology_t *cpudata,
 static void write_schedulers_bind_change(erts_cpu_topology_t *cpudata, int size);
 
 static void reader_groups_callback(int, ErtsSchedulerData *, int, void *);
+static void flxctr_groups_callback(int, ErtsSchedulerData *, int, void *);
 static erts_cpu_groups_map_t *add_cpu_groups(int groups,
 					     erts_cpu_groups_callback_t callback,
 					     void *arg);
@@ -1646,7 +1651,8 @@ erts_get_logical_processors(int *conf, int *onln, int *avail)
 }
 
 void
-erts_pre_early_init_cpu_topology(int *max_rg_p,
+erts_pre_early_init_cpu_topology(int *max_dcg_p,
+                                 int *max_rg_p,
 				 int *conf_p,
 				 int *onln_p,
 				 int *avail_p)
@@ -1654,6 +1660,7 @@ erts_pre_early_init_cpu_topology(int *max_rg_p,
     cpu_groups_maps = NULL;
     no_cpu_groups_callbacks = 0;
     *max_rg_p = ERTS_MAX_READER_GROUPS;
+    *max_dcg_p = ERTS_MAX_FLXCTR_GROUPS;
     cpuinfo = erts_cpu_info_create();
     get_logical_processors(conf_p, onln_p, avail_p);
 }
@@ -1662,7 +1669,9 @@ void
 erts_early_init_cpu_topology(int no_schedulers,
 			     int *max_main_threads_p,
 			     int max_reader_groups,
-			     int *reader_groups_p)
+			     int *reader_groups_p,
+                             int max_decentralized_counter_groups,
+                             int *decentralized_counter_groups_p)
 {
     user_cpudata = NULL;
     user_cpudata_size = 0;
@@ -1687,6 +1696,12 @@ erts_early_init_cpu_topology(int no_schedulers,
 	max_main_threads = no_schedulers;
     *max_main_threads_p = max_main_threads;
 
+    decentralized_counter_groups = max_main_threads;
+    if (decentralized_counter_groups <= 1 || max_decentralized_counter_groups <= 1)
+	decentralized_counter_groups = 1;
+    if (decentralized_counter_groups > max_decentralized_counter_groups)
+	decentralized_counter_groups = max_decentralized_counter_groups;
+    *decentralized_counter_groups_p = decentralized_counter_groups;
     reader_groups = max_main_threads;
     if (reader_groups <= 1 || max_reader_groups <= 1)
 	reader_groups = 0;
@@ -1718,6 +1733,9 @@ erts_init_cpu_topology(void)
     reader_groups_map = add_cpu_groups(reader_groups,
 				       reader_groups_callback,
 				       NULL);
+    decentralized_counter_groups_map = add_cpu_groups(decentralized_counter_groups,
+                                                      flxctr_groups_callback,
+                                                      NULL);
 
     if (cpu_bind_order == ERTS_CPU_BIND_NONE)
 	erts_rwmtx_rwunlock(&cpuinfo_rwmtx);
@@ -1789,6 +1807,15 @@ reader_groups_callback(int suspending,
 	erts_rwmtx_set_reader_group(suspending ? 0 : group+1);
 }
 
+void
+flxctr_groups_callback(int suspending,
+		       ErtsSchedulerData *esdp,
+		       int group,
+		       void *unused)
+{
+    erts_flxctr_set_slot(suspending ? 0 : group+1);
+}
+
 static Eterm get_cpu_groups_map(Process *c_p,
 				erts_cpu_groups_map_t *map,
 				int offset);
@@ -1821,6 +1848,16 @@ erts_get_reader_groups_map(Process *c_p)
     return res;
 }
 
+Eterm
+erts_get_decentralized_counter_groups_map(Process *c_p)
+{
+    Eterm res;
+    erts_rwmtx_rlock(&cpuinfo_rwmtx);
+    res = get_cpu_groups_map(c_p, decentralized_counter_groups_map, 1);
+    erts_rwmtx_runlock(&cpuinfo_rwmtx);
+    return res;
+}
+
 /*
  * CPU groups
  */
diff --git a/erts/emulator/beam/erl_cpu_topology.h b/erts/emulator/beam/erl_cpu_topology.h
index 88bcad79ab..4a428d7972 100644
--- a/erts/emulator/beam/erl_cpu_topology.h
+++ b/erts/emulator/beam/erl_cpu_topology.h
@@ -27,14 +27,19 @@
 #ifndef ERL_CPU_TOPOLOGY_H__
 #define ERL_CPU_TOPOLOGY_H__
 
-void erts_pre_early_init_cpu_topology(int *max_rg_p,
-				      int *conf_p,
-				      int *onln_p,
-				      int *avail_p);
-void erts_early_init_cpu_topology(int no_schedulers,
-				  int *max_main_threads_p,
-				  int max_reader_groups,
-				  int *reader_groups_p);
+void
+erts_pre_early_init_cpu_topology(int *max_dcg_p,
+                                 int *max_rg_p,
+				 int *conf_p,
+				 int *onln_p,
+				 int *avail_p);
+void
+erts_early_init_cpu_topology(int no_schedulers,
+			     int *max_main_threads_p,
+			     int max_reader_groups,
+			     int *reader_groups_p,
+                             int max_decentralized_counter_groups,
+                             int *decentralized_counter_groups_p);
 void erts_init_cpu_topology(void);
 
 
@@ -70,6 +75,7 @@ Eterm erts_bind_schedulers(Process *c_p, Eterm how);
 Eterm erts_get_schedulers_binds(Process *c_p);
 
 Eterm erts_get_reader_groups_map(Process *c_p);
+Eterm erts_get_decentralized_counter_groups_map(Process *c_p);
 
 Eterm erts_set_cpu_topology(Process *c_p, Eterm term);
 Eterm erts_get_cpu_topology_term(Process *c_p, Eterm which);
diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index c009a3bde8..3c74ef493b 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -42,6 +42,7 @@
 #include "bif.h"
 #include "big.h"
 #include "erl_binary.h"
+#include "bif.h"
 
 
 erts_atomic_t erts_ets_misc_mem_size;
@@ -64,6 +65,11 @@ do {                                                                     \
     }                                                                    \
 }while(0)
 
+#define DB_GET_APPROX_NITEMS(DB)                                        \
+    erts_flxctr_read_approx(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID)
+#define DB_GET_APPROX_MEM_CONSUMED(DB)                                  \
+    erts_flxctr_read_approx(&(DB)->common.counters, ERTS_DB_TABLE_MEM_COUNTER_ID)
+
 static BIF_RETTYPE db_bif_fail(Process* p, Uint freason,
                                Uint bif_ix, Export* bif_exp)
 {
@@ -81,16 +87,9 @@ static BIF_RETTYPE db_bif_fail(Process* p, Uint freason,
 /* Get a key from any table structure and a tagged object */
 #define TERM_GETKEY(tb, obj) db_getkey((tb)->common.keypos, (obj)) 
 
- 
-/* How safe are we from double-hits or missed objects
-** when iterating without fixation? */ 
-enum DbIterSafety {
-    ITER_UNSAFE,      /* Must fixate to be safe */
-    ITER_SAFE_LOCKED, /* Safe while table is locked, not between trap calls */
-    ITER_SAFE         /* No need to fixate at all */
-};
 #  define ITERATION_SAFETY(Proc,Tab) \
-    ((IS_TREE_TABLE((Tab)->common.status) || ONLY_WRITER(Proc,Tab)) ? ITER_SAFE \
+    ((IS_TREE_TABLE((Tab)->common.status) || IS_CATREE_TABLE((Tab)->common.status) \
+      || ONLY_WRITER(Proc,Tab)) ? ITER_SAFE                             \
      : (((Tab)->common.status & DB_FINE_LOCKED) ? ITER_UNSAFE : ITER_SAFE_LOCKED))
 
 #define DID_TRAP(P,Ret) (!is_value(Ret) && ((P)->freason == TRAP))
@@ -194,9 +193,6 @@ static int fixed_tabs_find(DbFixation* first, DbFixation* fix)
 #define ERTS_RBT_WANT_DELETE
 #define ERTS_RBT_WANT_FOREACH
 #define ERTS_RBT_WANT_FOREACH_DESTROY
-#ifdef DEBUG
-# define ERTS_RBT_WANT_LOOKUP
-#endif
 #define ERTS_RBT_UNDEF
 
 #include "erl_rbtree.h"
@@ -359,6 +355,7 @@ typedef enum {
 
 extern DbTableMethod db_hash;
 extern DbTableMethod db_tree;
+extern DbTableMethod db_catree;
 
 int user_requested_db_max_tabs;
 int erts_ets_realloc_always_moves;
@@ -407,21 +404,19 @@ static void
 free_dbtable(void *vtb)
 {
     DbTable *tb = (DbTable *) vtb;
-#ifdef HARDDEBUG
-	if (erts_atomic_read_nob(&tb->common.memory_size) != sizeof(DbTable)) {
-	    erts_fprintf(stderr, "ets: free_dbtable memory remain=%ld fix=%x\n",
-			 erts_atomic_read_nob(&tb->common.memory_size)-sizeof(DbTable),
-			 tb->common.fixations);
-	}
-#endif
-	erts_rwmtx_destroy(&tb->common.rwlock);
-	erts_mtx_destroy(&tb->common.fixlock);
-	ASSERT(is_immed(tb->common.heir_data));
+    ASSERT(erts_flxctr_is_snapshot_ongoing(&tb->common.counters) ||
+           sizeof(DbTable) == erts_flxctr_read_approx(&tb->common.counters,
+                                                      ERTS_DB_TABLE_MEM_COUNTER_ID));
+
+    erts_rwmtx_destroy(&tb->common.rwlock);
+    erts_mtx_destroy(&tb->common.fixlock);
+    ASSERT(is_immed(tb->common.heir_data));
 
-        if (tb->common.btid)
-            erts_bin_release(tb->common.btid);
+    if (tb->common.btid)
+        erts_bin_release(tb->common.btid);
 
-	erts_db_free(ERTS_ALC_T_DB_TABLE, tb, (void *) tb, sizeof(DbTable));
+    erts_flxctr_destroy(&tb->common.counters, ERTS_ALC_T_DB_TABLE);
+    erts_free(ERTS_ALC_T_DB_TABLE, tb);
 }
 
 static void schedule_free_dbtable(DbTable* tb)
@@ -1076,7 +1071,7 @@ BIF_RETTYPE ets_update_element_3(BIF_ALIST_3)
     DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE_REC, BIF_ets_update_element_3);
 
     UseTmpHeap(2,BIF_P);
-    if (!(tb->common.status & (DB_SET | DB_ORDERED_SET))) {
+    if (!(tb->common.status & (DB_SET | DB_ORDERED_SET | DB_CA_ORDERED_SET))) {
 	goto bail_out;
     }
     if (is_tuple(BIF_ARG_3)) {
@@ -1165,7 +1160,7 @@ do_update_counter(Process *p, DbTable* tb,
 
     UseTmpHeap(5, p);
 
-    if (!(tb->common.status & (DB_SET | DB_ORDERED_SET))) {
+    if (!(tb->common.status & (DB_SET | DB_ORDERED_SET | DB_CA_ORDERED_SET))) {
 	goto bail_out;
     }
     if (is_integer(arg3)) { /* Incr */
@@ -1647,15 +1642,15 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
 	val = CAR(list_val(list));
 	if (val == am_bag) {
 	    status |= DB_BAG;
-	    status &= ~(DB_SET | DB_DUPLICATE_BAG | DB_ORDERED_SET);
+	    status &= ~(DB_SET | DB_DUPLICATE_BAG | DB_ORDERED_SET | DB_CA_ORDERED_SET);
 	}
 	else if (val == am_duplicate_bag) {
 	    status |= DB_DUPLICATE_BAG;
-	    status &= ~(DB_SET | DB_BAG | DB_ORDERED_SET);
+	    status &= ~(DB_SET | DB_BAG | DB_ORDERED_SET | DB_CA_ORDERED_SET);
 	}
 	else if (val == am_ordered_set) {
 	    status |= DB_ORDERED_SET;
-	    status &= ~(DB_SET | DB_BAG | DB_DUPLICATE_BAG);
+	    status &= ~(DB_SET | DB_BAG | DB_DUPLICATE_BAG | DB_CA_ORDERED_SET);
 	}
 	else if (is_tuple(val)) {
 	    Eterm *tp = tuple_val(val);
@@ -1716,7 +1711,13 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     if (is_not_nil(list)) { /* bad opt or not a well formed list */
 	BIF_ERROR(BIF_P, BADARG);
     }
-    if (IS_HASH_TABLE(status)) {
+    if (IS_TREE_TABLE(status) && is_fine_locked && !(status & DB_PRIVATE)) {
+        meth = &db_catree;
+        status |= DB_CA_ORDERED_SET;
+        status &= ~(DB_SET | DB_BAG | DB_DUPLICATE_BAG | DB_ORDERED_SET);
+        status |= DB_FINE_LOCKED;
+    }
+    else if (IS_HASH_TABLE(status)) {
 	meth = &db_hash;
 	if (is_fine_locked && !(status & DB_PRIVATE)) {
 	    status |= DB_FINE_LOCKED;
@@ -1738,12 +1739,16 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
      */
     {
         DbTable init_tb;
-
-	erts_atomic_init_nob(&init_tb.common.memory_size, 0);
+        erts_flxctr_init(&init_tb.common.counters, 0, 2, ERTS_ALC_T_DB_TABLE);
 	tb = (DbTable*) erts_db_alloc(ERTS_ALC_T_DB_TABLE,
 				      &init_tb, sizeof(DbTable));
-	erts_atomic_init_nob(&tb->common.memory_size,
-				 erts_atomic_read_nob(&init_tb.common.memory_size));
+        erts_flxctr_init(&tb->common.counters,
+                         status & DB_CA_ORDERED_SET,
+                         2,
+                         ERTS_ALC_T_DB_TABLE);
+        erts_flxctr_add(&tb->common.counters,
+                        ERTS_DB_TABLE_MEM_COUNTER_ID,
+                        DB_GET_APPROX_MEM_CONSUMED(&init_tb));
     }
 
     tb->common.meth = meth;
@@ -1757,8 +1762,6 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     tb->common.owner = BIF_P->common.id;
     set_heir(BIF_P, tb, heir, heir_data);
 
-    erts_atomic_init_nob(&tb->common.nitems, 0);
-
     tb->common.fixing_procs = NULL;
     tb->common.compress = is_compressed;
 #ifdef ETS_DBG_FORCE_TRAP
@@ -2135,19 +2138,18 @@ BIF_RETTYPE ets_internal_delete_all_2(BIF_ALIST_2)
 {
     SWord initial_reds = ERTS_BIF_REDS_LEFT(BIF_P);
     SWord reds = initial_reds;
-    Eterm nitems;
+    Eterm nitems_holder = THE_NON_VALUE;
     DbTable* tb;
-
     CHECK_TABLES();
 
     DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE, BIF_ets_internal_delete_all_2);
 
     if (BIF_ARG_2 == am_undefined) {
-        nitems = erts_make_integer(erts_atomic_read_nob(&tb->common.nitems),
-                                   BIF_P);
-
-        reds = tb->common.meth->db_delete_all_objects(BIF_P, tb, reds);
-
+        reds = tb->common.meth->db_delete_all_objects(BIF_P,
+                                                      tb,
+                                                      reds,
+                                                      &nitems_holder);
+        ASSERT(nitems_holder != THE_NON_VALUE);
         ASSERT(!(tb->common.status & DB_BUSY));
 
         if (reds < 0) {
@@ -2166,7 +2168,7 @@ BIF_RETTYPE ets_internal_delete_all_2(BIF_ALIST_2)
             db_unlock(tb, LCK_WRITE);
             BUMP_ALL_REDS(BIF_P);
             BIF_TRAP2(bif_export[BIF_ets_internal_delete_all_2], BIF_P,
-                      BIF_ARG_1, nitems);
+                      BIF_ARG_1, nitems_holder);
         }
         else {
             /* Done, no trapping needed */
@@ -2176,15 +2178,19 @@ BIF_RETTYPE ets_internal_delete_all_2(BIF_ALIST_2)
     }
     else {
         /*
-         * The table lookup succeeded and second argument is nitems
+         * The table lookup succeeded and second argument is nitems_holder
          * and not 'undefined', which means we have trapped at least once
          * and are now done.
          */
-        nitems = BIF_ARG_2;
+        nitems_holder = BIF_ARG_2;
     }
-
     db_unlock(tb, LCK_WRITE);
+    {
+    Eterm nitems =
+        tb->common.meth->db_delete_all_objects_get_nitems_from_holder(BIF_P,
+                                                                      nitems_holder);
     BIF_RET(nitems);
+    }
 }
 
 static void delete_all_objects_continue(Process* p, DbTable* tb)
@@ -2197,7 +2203,7 @@ static void delete_all_objects_continue(Process* p, DbTable* tb)
     if ((tb->common.status & (DB_DELETE|DB_BUSY)) != DB_BUSY)
         return;
 
-    reds = tb->common.meth->db_delete_all_objects(p, tb, reds);
+    reds = tb->common.meth->db_delete_all_objects(p, tb, reds, NULL);
     
     if (reds < 0) {
         BUMP_ALL_REDS(p);
@@ -2283,6 +2289,7 @@ static BIF_RETTYPE ets_select_delete_trap_1(BIF_ALIST_1)
     Eterm ret;
     Eterm *tptr;
     db_lock_kind_t kind = LCK_WRITE_REC;
+    enum DbIterSafety safety = ITER_SAFE;
 
     CHECK_TABLES();
     ASSERT(is_tuple(a1));
@@ -2292,10 +2299,11 @@ static BIF_RETTYPE ets_select_delete_trap_1(BIF_ALIST_1)
     DB_TRAP_GET_TABLE(tb, tptr[1], DB_WRITE, kind,
                       &ets_select_delete_continue_exp);
 
-    cret = tb->common.meth->db_select_delete_continue(p,tb,a1,&ret);
+    cret = tb->common.meth->db_select_delete_continue(p,tb,a1,&ret,&safety);
 
-    if(!DID_TRAP(p,ret) && ITERATION_SAFETY(p,tb) != ITER_SAFE) {  
-	unfix_table_locked(p, tb, &kind);
+    if(!DID_TRAP(p,ret) && safety != ITER_SAFE) {
+        ASSERT(erts_refc_read(&tb->common.fix_count,1));
+        unfix_table_locked(p, tb, &kind);
     }
 
     db_unlock(tb, kind);
@@ -2333,7 +2341,8 @@ BIF_RETTYPE ets_internal_select_delete_2(BIF_ALIST_2)
     if (safety == ITER_UNSAFE) {
 	local_fix_table(tb);
     }
-    cret = tb->common.meth->db_select_delete(BIF_P, tb, BIF_ARG_1, BIF_ARG_2, &ret);
+    cret = tb->common.meth->db_select_delete(BIF_P, tb, BIF_ARG_1, BIF_ARG_2,
+                                             &ret, safety);
 
     if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
 	fix_table_locked(BIF_P,tb);
@@ -2725,7 +2734,7 @@ ets_select3(Process* p, DbTable* tb, Eterm tid, Eterm ms, Sint chunk_size)
     cret = tb->common.meth->db_select_chunk(p, tb, tid,
 					    ms, chunk_size,
 					    0 /* not reversed */,
-					    &ret);
+					    &ret, safety);
     if (DID_TRAP(p,ret) && safety != ITER_SAFE) {
 	fix_table_locked(p, tb);
     }
@@ -2752,7 +2761,8 @@ ets_select3(Process* p, DbTable* tb, Eterm tid, Eterm ms, Sint chunk_size)
 }
 
 
-/* We get here instead of in the real BIF when trapping */
+/* Trap here from: ets_select_1/2/3
+ */
 static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
 {
     Process *p = BIF_P;
@@ -2763,6 +2773,7 @@ static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
     Eterm ret;
     Eterm *tptr;
     db_lock_kind_t kind = LCK_READ;
+    enum DbIterSafety safety = ITER_SAFE;
 
     CHECK_TABLES();
 
@@ -2772,11 +2783,13 @@ static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
     DB_TRAP_GET_TABLE(tb, tptr[1], DB_READ, kind,
                       &ets_select_continue_exp);
 
-    cret = tb->common.meth->db_select_continue(p, tb, a1,
-					       &ret);
+    cret = tb->common.meth->db_select_continue(p, tb, a1, &ret, &safety);
 
-    if (!DID_TRAP(p,ret) && ITERATION_SAFETY(p,tb) != ITER_SAFE) {
-	unfix_table_locked(p, tb, &kind);
+    if (!DID_TRAP(p,ret)) {
+        if (safety != ITER_SAFE) {
+            ASSERT(erts_refc_read(&tb->common.fix_count,1));
+            unfix_table_locked(p, tb, &kind);
+        }
     }
     db_unlock(tb, kind);
 
@@ -2801,8 +2814,12 @@ static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
 BIF_RETTYPE ets_select_1(BIF_ALIST_1)
 {
     return ets_select1(BIF_P, BIF_ets_select_1, BIF_ARG_1);
+    /* TRAP: ets_select_trap_1 */
 }
 
+/*
+ * Common impl for select/1, select_reverse/1, match/1 and match_object/1
+ */
 static BIF_RETTYPE ets_select1(Process *p, int bif_ix, Eterm arg1)
 {
     BIF_RETTYPE result;
@@ -2810,7 +2827,7 @@ static BIF_RETTYPE ets_select1(Process *p, int bif_ix, Eterm arg1)
     int cret;
     Eterm ret;
     Eterm *tptr;
-    enum DbIterSafety safety;
+    enum DbIterSafety safety, safety_copy;
 
     CHECK_TABLES();
 
@@ -2835,7 +2852,8 @@ static BIF_RETTYPE ets_select1(Process *p, int bif_ix, Eterm arg1)
 	local_fix_table(tb);
     }
 
-    cret = tb->common.meth->db_select_continue(p,tb, arg1, &ret);
+    safety_copy = safety;
+    cret = tb->common.meth->db_select_continue(p,tb, arg1, &ret, &safety_copy);
 
     if (DID_TRAP(p,ret) && safety != ITER_SAFE) {
 	fix_table_locked(p, tb);
@@ -2867,6 +2885,7 @@ BIF_RETTYPE ets_select_2(BIF_ALIST_2)
     DbTable* tb;
     DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_select_2);
     return ets_select2(BIF_P, tb, BIF_ARG_1, BIF_ARG_2);
+    /* TRAP: ets_select_trap_1 */
 }
 
 static BIF_RETTYPE
@@ -2884,7 +2903,7 @@ ets_select2(Process* p, DbTable* tb, Eterm tid, Eterm ms)
 	local_fix_table(tb);
     }
 
-    cret = tb->common.meth->db_select(p, tb, tid, ms, 0, &ret);
+    cret = tb->common.meth->db_select(p, tb, tid, ms, 0, &ret, safety);
 
     if (DID_TRAP(p,ret) && safety != ITER_SAFE) {
 	fix_table_locked(p, tb);
@@ -2922,6 +2941,7 @@ static BIF_RETTYPE ets_select_count_1(BIF_ALIST_1)
     Eterm ret;
     Eterm *tptr;
     db_lock_kind_t kind = LCK_READ;
+    enum DbIterSafety safety = ITER_SAFE;
 
     CHECK_TABLES();
 
@@ -2931,9 +2951,10 @@ static BIF_RETTYPE ets_select_count_1(BIF_ALIST_1)
     DB_TRAP_GET_TABLE(tb, tptr[1], DB_READ, kind,
                       &ets_select_count_continue_exp);
 
-    cret = tb->common.meth->db_select_count_continue(p, tb, a1, &ret);
+    cret = tb->common.meth->db_select_count_continue(p, tb, a1, &ret, &safety);
 
-    if (!DID_TRAP(p,ret) && ITERATION_SAFETY(p,tb) != ITER_SAFE) {
+    if (!DID_TRAP(p,ret) && safety != ITER_SAFE) {
+        ASSERT(erts_refc_read(&tb->common.fix_count,1));
 	unfix_table_locked(p, tb, &kind);
     }
     db_unlock(tb, kind);
@@ -2971,7 +2992,8 @@ BIF_RETTYPE ets_select_count_2(BIF_ALIST_2)
     if (safety == ITER_UNSAFE) {
 	local_fix_table(tb);
     }
-    cret = tb->common.meth->db_select_count(BIF_P,tb, BIF_ARG_1, BIF_ARG_2, &ret);
+    cret = tb->common.meth->db_select_count(BIF_P,tb, BIF_ARG_1, BIF_ARG_2,
+                                            &ret, safety);
 
     if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
 	fix_table_locked(BIF_P, tb);
@@ -3010,6 +3032,7 @@ static BIF_RETTYPE ets_select_replace_1(BIF_ALIST_1)
     Eterm ret;
     Eterm *tptr;
     db_lock_kind_t kind = LCK_WRITE_REC;
+    enum DbIterSafety safety = ITER_SAFE;
 
     CHECK_TABLES();
     ASSERT(is_tuple(a1));
@@ -3019,9 +3042,10 @@ static BIF_RETTYPE ets_select_replace_1(BIF_ALIST_1)
     DB_TRAP_GET_TABLE(tb, tptr[1], DB_WRITE, kind,
                       &ets_select_replace_continue_exp);
 
-    cret = tb->common.meth->db_select_replace_continue(p,tb,a1,&ret);
+    cret = tb->common.meth->db_select_replace_continue(p,tb,a1,&ret,&safety);
 
-    if(!DID_TRAP(p,ret) && ITERATION_SAFETY(p,tb) != ITER_SAFE) {
+    if(!DID_TRAP(p,ret) && safety != ITER_SAFE) {
+        ASSERT(erts_refc_read(&tb->common.fix_count,1));
         unfix_table_locked(p, tb, &kind);
     }
 
@@ -3064,7 +3088,8 @@ BIF_RETTYPE ets_select_replace_2(BIF_ALIST_2)
     if (safety == ITER_UNSAFE) {
         local_fix_table(tb);
     }
-    cret = tb->common.meth->db_select_replace(BIF_P, tb, BIF_ARG_1, BIF_ARG_2, &ret);
+    cret = tb->common.meth->db_select_replace(BIF_P, tb, BIF_ARG_1, BIF_ARG_2,
+                                              &ret, safety);
 
     if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
         fix_table_locked(BIF_P,tb);
@@ -3116,7 +3141,7 @@ BIF_RETTYPE ets_select_reverse_3(BIF_ALIST_3)
     }
     cret = tb->common.meth->db_select_chunk(BIF_P,tb, BIF_ARG_1,
 					    BIF_ARG_2, chunk_size, 
-					    1 /* reversed */, &ret);
+					    1 /* reversed */, &ret, safety);
     if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
 	fix_table_locked(BIF_P, tb);
     }
@@ -3161,7 +3186,7 @@ BIF_RETTYPE ets_select_reverse_2(BIF_ALIST_2)
 	local_fix_table(tb);
     }
     cret = tb->common.meth->db_select(BIF_P,tb, BIF_ARG_1, BIF_ARG_2,
-				      1 /*reversed*/, &ret);
+				      1 /*reversed*/, &ret, safety);
 
     if (DID_TRAP(BIF_P,ret) && safety != ITER_SAFE) {
 	fix_table_locked(BIF_P, tb);
@@ -3265,13 +3290,29 @@ BIF_RETTYPE ets_info_1(BIF_ALIST_1)
     int i;
     Eterm* hp;
     Uint freason;
+    Sint size = -1;
+    Sint memory = -1;
+    Eterm table;
+    int is_ctrs_read_result_set = 0;
     /*Process* rp = NULL;*/
     /* If/when we implement lockless private tables:
     Eterm owner;
     */
-
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ, &freason)) == NULL) {
-	if (freason == BADARG && (is_atom(BIF_ARG_1) || is_ref(BIF_ARG_1)))
+    if(is_tuple(BIF_ARG_1) &&
+       is_tuple_arity(BIF_ARG_1, 2) &&
+       erts_flxctr_is_snapshot_result(tuple_val(BIF_ARG_1)[1])) {
+        Eterm counter_read_result  = tuple_val(BIF_ARG_1)[1];
+        table = tuple_val(BIF_ARG_1)[2];
+        size = erts_flxctr_get_snapshot_result_after_trap(counter_read_result,
+                                                          ERTS_DB_TABLE_NITEMS_COUNTER_ID);
+        memory = erts_flxctr_get_snapshot_result_after_trap(counter_read_result,
+                                                            ERTS_DB_TABLE_MEM_COUNTER_ID);
+        is_ctrs_read_result_set = 1;
+    } else {
+        table = BIF_ARG_1;
+    }
+    if ((tb = db_get_table(BIF_P, table, DB_INFO, LCK_READ, &freason)) == NULL) {
+	if (freason == BADARG && (is_atom(table) || is_ref(table)))
 	    BIF_RET(am_undefined);
 	else
             return db_bif_fail(BIF_P, freason, BIF_ets_info_1, NULL);
@@ -3302,9 +3343,35 @@ BIF_RETTYPE ets_info_1(BIF_ALIST_1)
 	    BIF_ERROR(BIF_P, BADARG);
 	}
     }*/
+
+    if (!is_ctrs_read_result_set) {
+        ErtsFlxCtrSnapshotResult res =
+            erts_flxctr_snapshot(&tb->common.counters, ERTS_ALC_T_DB_TABLE, BIF_P);
+        if (ERTS_FLXCTR_GET_RESULT_AFTER_TRAP == res.type) {
+            Eterm tuple;
+            db_unlock(tb, LCK_READ);
+            hp = HAlloc(BIF_P, 3);
+            tuple = TUPLE2(hp, res.trap_resume_state, table);
+            BIF_TRAP1(bif_export[BIF_ets_info_1], BIF_P, tuple);
+        } else if (res.type == ERTS_FLXCTR_TRY_AGAIN_AFTER_TRAP) {
+            db_unlock(tb, LCK_READ);
+            BIF_TRAP1(bif_export[BIF_ets_info_1], BIF_P, table);
+        } else {
+            size = res.result[ERTS_DB_TABLE_NITEMS_COUNTER_ID];
+            memory = res.result[ERTS_DB_TABLE_MEM_COUNTER_ID];
+            is_ctrs_read_result_set = 1;
+        }
+    }
     for (i = 0; i < sizeof(fields)/sizeof(Eterm); i++) {
-	results[i] = table_info(BIF_P, tb, fields[i]);
-	ASSERT(is_value(results[i]));
+        if (is_ctrs_read_result_set && am_size == fields[i]) {
+            results[i] = erts_make_integer(size, BIF_P);
+        } else if (is_ctrs_read_result_set && am_memory == fields[i]) {
+            Sint words = (Sint) ((memory + sizeof(Sint) - 1) / sizeof(Sint));
+            results[i] = erts_make_integer(words, BIF_P);
+        } else {
+            results[i] = table_info(BIF_P, tb, fields[i]);
+            ASSERT(is_value(results[i]));
+        }
     }
     db_unlock(tb, LCK_READ);
 
@@ -3332,14 +3399,43 @@ BIF_RETTYPE ets_info_2(BIF_ALIST_2)
     DbTable* tb;
     Eterm ret = THE_NON_VALUE;
     Uint freason;
-
+    if (erts_flxctr_is_snapshot_result(BIF_ARG_1)) {
+        Sint res;
+        if (am_memory == BIF_ARG_2) {
+            res = erts_flxctr_get_snapshot_result_after_trap(BIF_ARG_1,
+                                                             ERTS_DB_TABLE_MEM_COUNTER_ID);
+            res = (Sint) ((res + sizeof(Sint) - 1) / sizeof(Sint));
+        } else {
+            res = erts_flxctr_get_snapshot_result_after_trap(BIF_ARG_1,
+                                                             ERTS_DB_TABLE_NITEMS_COUNTER_ID);
+        }
+        BIF_RET(erts_make_integer(res, BIF_P));
+    }
     if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ, &freason)) == NULL) {
 	if (freason == BADARG && (is_atom(BIF_ARG_1) || is_ref(BIF_ARG_1)))
 	    BIF_RET(am_undefined);
         else
             return db_bif_fail(BIF_P, freason, BIF_ets_info_2, NULL);
     }
-    ret = table_info(BIF_P, tb, BIF_ARG_2);
+    if (BIF_ARG_2 == am_size || BIF_ARG_2 == am_memory) {
+        ErtsFlxCtrSnapshotResult res =
+            erts_flxctr_snapshot(&tb->common.counters, ERTS_ALC_T_DB_TABLE, BIF_P);
+        if (ERTS_FLXCTR_GET_RESULT_AFTER_TRAP == res.type) {
+            db_unlock(tb, LCK_READ);
+            BIF_TRAP2(bif_export[BIF_ets_info_2], BIF_P, res.trap_resume_state, BIF_ARG_2);
+        } else if (res.type == ERTS_FLXCTR_TRY_AGAIN_AFTER_TRAP) {
+            db_unlock(tb, LCK_READ);
+            BIF_TRAP2(bif_export[BIF_ets_info_2], BIF_P, BIF_ARG_1, BIF_ARG_2);
+        } else if (BIF_ARG_2 == am_size) {
+            ret = erts_make_integer(res.result[ERTS_DB_TABLE_NITEMS_COUNTER_ID], BIF_P);
+        } else { /* BIF_ARG_2 == am_memory */
+            Sint r = res.result[ERTS_DB_TABLE_MEM_COUNTER_ID];
+            r = (Sint) ((r + sizeof(Sint) - 1) / sizeof(Sint));
+            ret = erts_make_integer(r, BIF_P);
+        }
+    } else {
+        ret = table_info(BIF_P, tb, BIF_ARG_2);
+    }
     db_unlock(tb, LCK_READ);
     if (is_non_value(ret)) {
 	BIF_ERROR(BIF_P, BADARG);
@@ -3506,6 +3602,7 @@ void init_db(ErtsDbSpinCount db_spin_count)
 
     db_initialize_hash();
     db_initialize_tree();
+    db_initialize_catree();
 
     /* Non visual BIF to trap to. */
     erts_init_trap_export(&ets_select_delete_continue_exp,
@@ -3696,7 +3793,7 @@ static SWord proc_cleanup_fixed_table(Process* p, DbFixation* fix)
 /*
  * erts_db_process_exiting() is called when a process terminates.
  * It returns 0 when completely done, and !0 when it wants to
- * yield. c_p->u.terminate can hold a pointer to a state while
+ * yield. *yield_state can hold a pointer to a state while
  * yielding.
  */
 #define ERTS_DB_INTERNAL_ERROR(LSTR) \
@@ -3704,7 +3801,7 @@ static SWord proc_cleanup_fixed_table(Process* p, DbFixation* fix)
 	   __FILE__, __LINE__)
 
 int
-erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
+erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks, void **yield_state)
 {
     typedef struct {
         enum {
@@ -3714,7 +3811,7 @@ erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
         }op;
         DbTable *tb;
     } CleanupState;
-    CleanupState *state = (CleanupState *) c_p->u.terminate;
+    CleanupState *state = (CleanupState *) *yield_state;
     Eterm pid = c_p->common.id;
     CleanupState default_state;
     SWord initial_reds = ERTS_BIF_REDS_LEFT(c_p);
@@ -3787,7 +3884,7 @@ erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
 
                 if (state != &default_state)
                     erts_free(ERTS_ALC_T_DB_PROC_CLEANUP, state);
-                c_p->u.terminate = NULL;
+                *yield_state = NULL;
 
                 BUMP_REDS(c_p, (initial_reds - reds));
                 return 0;
@@ -3807,12 +3904,12 @@ erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
  yield:
 
     if (state == &default_state) {
-	c_p->u.terminate = erts_alloc(ERTS_ALC_T_DB_PROC_CLEANUP,
-				      sizeof(CleanupState));
-	sys_memcpy(c_p->u.terminate, (void*) state, sizeof(CleanupState));
+	*yield_state = erts_alloc(ERTS_ALC_T_DB_PROC_CLEANUP,
+                                  sizeof(CleanupState));
+	sys_memcpy(*yield_state, (void*) state, sizeof(CleanupState));
     }
     else
-        ASSERT(state == c_p->u.terminate);
+        ASSERT(state == *yield_state);
 
     return !0;
 }
@@ -3907,7 +4004,7 @@ struct free_fixations_ctx
     SWord cnt;
 };
 
-static void free_fixations_op(DbFixation* fix, void* vctx)
+static int free_fixations_op(DbFixation* fix, void* vctx, Sint reds)
 {
     struct free_fixations_ctx* ctx = (struct free_fixations_ctx*) vctx;
     erts_aint_t diff;
@@ -3944,6 +4041,7 @@ static void free_fixations_op(DbFixation* fix, void* vctx)
         ERTS_ETS_MISC_MEM_ADD(-sizeof(DbFixation));
     }
     ctx->cnt++;
+    return 1;
 }
 
 int erts_db_execute_free_fixation(Process* p, DbFixation* fix)
@@ -4088,7 +4186,7 @@ struct fixing_procs_info_ctx
     Eterm list;
 };
 
-static void fixing_procs_info_op(DbFixation* fix, void* vctx)
+static int fixing_procs_info_op(DbFixation* fix, void* vctx, Sint reds)
 {
     struct fixing_procs_info_ctx* ctx = (struct fixing_procs_info_ctx*) vctx;
     Eterm* hp;
@@ -4098,6 +4196,7 @@ static void fixing_procs_info_op(DbFixation* fix, void* vctx)
     tpl = TUPLE2(hp, fix->procs.p->common.id, make_small(fix->counter));
     hp += 3;
     ctx->list = CONS(hp, tpl, ctx->list);
+    return 1;
 }
 
 static Eterm table_info(Process* p, DbTable* tb, Eterm What)
@@ -4106,7 +4205,8 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
     int use_monotonic;
 
     if (What == am_size) {
-	ret = make_small(erts_atomic_read_nob(&tb->common.nitems));
+        Uint size = (Uint) (DB_GET_APPROX_NITEMS(tb));
+        ret = erts_make_integer(size, p);
     } else if (What == am_type) {
 	if (tb->common.status & DB_SET)  {
 	    ret = am_set;
@@ -4114,12 +4214,14 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 	    ret = am_duplicate_bag;
 	} else if (tb->common.status & DB_ORDERED_SET) {
 	    ret = am_ordered_set;
+	} else if (tb->common.status & DB_CA_ORDERED_SET) {
+	    ret = am_ordered_set;
 	} else { /*TT*/
 	    ASSERT(tb->common.status & DB_BAG);
 	    ret = am_bag;
 	}
     } else if (What == am_memory) {
-	Uint words = (Uint) ((erts_atomic_read_nob(&tb->common.memory_size)
+	Uint words = (Uint) ((DB_GET_APPROX_MEM_CONSUMED(tb)
 			      + sizeof(Uint)
 			      - 1)
 			     / sizeof(Uint));
@@ -4240,9 +4342,20 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 			 make_small(stats.max_chain_len),
 			 make_small(stats.kept_items));
 	}
-	else {
+	else if (IS_CATREE_TABLE(tb->common.status)) {
+            DbCATreeStats stats;
+            Eterm* hp;
+
+            db_calc_stats_catree(&tb->catree, &stats);
+            hp = HAlloc(p, 4);
+            ret = TUPLE3(hp,
+                         make_small(stats.route_nodes),
+                         make_small(stats.base_nodes),
+                         make_small(stats.max_depth));
+
+        }
+        else
 	    ret = am_false;
-	}
     }
     return ret;
 }
@@ -4266,9 +4379,9 @@ static void print_table(fmtfn_t to, void *to_arg, int show,  DbTable* tb)
 
     tb->common.meth->db_print(to, to_arg, show, tb);
 
-    erts_print(to, to_arg, "Objects: %d\n", (int)erts_atomic_read_nob(&tb->common.nitems));
+    erts_print(to, to_arg, "Objects: %d\n", (int)DB_GET_APPROX_NITEMS(tb));
     erts_print(to, to_arg, "Words: %bpu\n",
-	       (Uint) ((erts_atomic_read_nob(&tb->common.memory_size)
+	       (Uint) ((DB_GET_APPROX_MEM_CONSUMED(tb)
 			+ sizeof(Uint)
 			- 1)
 		       / sizeof(Uint)));
@@ -4302,7 +4415,7 @@ void db_info(fmtfn_t to, void *to_arg, int show)    /* Called by break handler *
     pdbi.to_arg = to_arg;
     pdbi.show = show;
 
-    erts_db_foreach_table(db_info_print, &pdbi);
+    erts_db_foreach_table(db_info_print, &pdbi, !0);
 }
 
 Uint
@@ -4315,7 +4428,7 @@ erts_get_ets_misc_mem_size(void)
 
 /* SMP Note: May only be used when system is locked */
 void
-erts_db_foreach_table(void (*func)(DbTable *, void *), void *arg)
+erts_db_foreach_table(void (*func)(DbTable *, void *), void *arg, int alive_only)
 {
     int ix;
 
@@ -4327,7 +4440,7 @@ erts_db_foreach_table(void (*func)(DbTable *, void *), void *arg)
         if (first) {
             DbTable *tb = first;
             do {
-                if (is_table_alive(tb))
+                if (!alive_only || is_table_alive(tb))
                     (*func)(tb, arg);
                 tb = tb->common.all.next;
             } while (tb != first);
@@ -4344,6 +4457,15 @@ erts_db_foreach_offheap(DbTable *tb,
     tb->common.meth->db_foreach_offheap(tb, func, arg);
 }
 
+void
+erts_db_foreach_thr_prgr_offheap(void (*func)(ErlOffHeap *, void *),
+                                 void *arg)
+{
+    erts_db_foreach_thr_prgr_offheap_hash(func, arg);
+    erts_db_foreach_thr_prgr_offheap_tree(func, arg);
+    erts_db_foreach_thr_prgr_offheap_catree(func, arg);
+}
+
 /* retrieve max number of ets tables */
 Uint
 erts_db_get_max_tabs()
@@ -4409,6 +4531,12 @@ void erts_lcnt_enable_db_lock_count(DbTable *tb, int enable) {
 
     if(IS_HASH_TABLE(tb->common.status)) {
         erts_lcnt_enable_db_hash_lock_count(&tb->hash, enable);
+    } else if(IS_CATREE_TABLE(tb->common.status)) {
+        /* erts_lcnt_enable_db_catree_lock_count is not thread safe so
+           the table needs to get locked */
+        db_lock(tb, LCK_WRITE);
+        erts_lcnt_enable_db_catree_lock_count(&tb->catree, enable);
+        db_unlock(tb, LCK_WRITE);
     }
 }
 
@@ -4441,3 +4569,29 @@ void erts_lcnt_update_db_locks(int enable) {
 #ifdef ETS_DBG_FORCE_TRAP
 erts_aint_t erts_ets_dbg_force_trap = 0;
 #endif
+
+int erts_ets_force_split(Eterm tid, int on)
+{
+    DbTable* tb = tid2tab(tid);
+    if (!tb || !IS_CATREE_TABLE(tb->common.type))
+        return 0;
+
+    db_lock(tb, LCK_WRITE);
+    if (!(tb->common.status & DB_DELETE))
+        db_catree_force_split(&tb->catree, on);
+    db_unlock(tb, LCK_WRITE);
+    return 1;
+}
+
+int erts_ets_debug_random_split_join(Eterm tid, int on)
+{
+    DbTable* tb = tid2tab(tid);
+    if (!tb || !IS_CATREE_TABLE(tb->common.type))
+        return 0;
+
+    db_lock(tb, LCK_WRITE);
+    if (!(tb->common.status & DB_DELETE))
+        db_catree_debug_random_split_join(&tb->catree, on);
+    db_unlock(tb, LCK_WRITE);
+    return 1;
+}
diff --git a/erts/emulator/beam/erl_db.h b/erts/emulator/beam/erl_db.h
index 23975d208f..c604744687 100644
--- a/erts/emulator/beam/erl_db.h
+++ b/erts/emulator/beam/erl_db.h
@@ -66,6 +66,7 @@ typedef struct {
 #include "erl_db_util.h" /* Flags */
 #include "erl_db_hash.h" /* DbTableHash */
 #include "erl_db_tree.h" /* DbTableTree */
+#include "erl_db_catree.h" /* DbTableCATree */
 /*TT*/
 
 Uint erts_get_ets_misc_mem_size(void);
@@ -90,6 +91,7 @@ union db_table {
     DbTableCommon common; /* Any type of db table */
     DbTableHash hash;     /* Linear hash array specific data */
     DbTableTree tree;     /* AVL tree specific data */
+    DbTableCATree catree;     /* CA tree specific data */
     DbTableRelease release;
     /*TT*/
 };
@@ -109,13 +111,15 @@ typedef enum {
 } ErtsDbSpinCount;
 
 void init_db(ErtsDbSpinCount);
-int erts_db_process_exiting(Process *, ErtsProcLocks);
+int erts_db_process_exiting(Process *, ErtsProcLocks, void **);
 int erts_db_execute_free_fixation(Process*, DbFixation*);
 void db_info(fmtfn_t, void *, int);
-void erts_db_foreach_table(void (*)(DbTable *, void *), void *);
+void erts_db_foreach_table(void (*)(DbTable *, void *), void *, int);
 void erts_db_foreach_offheap(DbTable *,
 			     void (*func)(ErlOffHeap *, void *),
 			     void *);
+void erts_db_foreach_thr_prgr_offheap(void (*func)(ErlOffHeap *, void *),
+                                      void *);
 
 extern int erts_ets_rwmtx_spin_count;
 extern int user_requested_db_max_tabs; /* set in erl_init */
@@ -128,6 +132,8 @@ extern Export ets_select_continue_exp;
 extern erts_atomic_t erts_ets_misc_mem_size;
 
 Eterm erts_ets_colliding_names(Process*, Eterm name, Uint cnt);
+int erts_ets_force_split(Eterm tid, int on);
+int erts_ets_debug_random_split_join(Eterm tid, int on);
 Uint erts_db_get_max_tabs(void);
 Eterm erts_db_make_tid(Process *c_p, DbTableCommon *tb);
 
@@ -157,7 +163,9 @@ do {									\
     erts_aint_t sz__ = (((erts_aint_t) (ALLOC_SZ))			\
 			- ((erts_aint_t) (FREE_SZ)));			\
     ASSERT((TAB));							\
-    erts_atomic_add_nob(&(TAB)->common.memory_size, sz__);		\
+    erts_flxctr_add(&(TAB)->common.counters,                            \
+                    ERTS_DB_TABLE_MEM_COUNTER_ID,                       \
+                    sz__);                                              \
 } while (0)
 
 #define ERTS_ETS_MISC_MEM_ADD(SZ) \
@@ -284,6 +292,12 @@ ERTS_GLB_INLINE void erts_db_free(ErtsAlcType_t type,
 				  void *ptr,
 				  Uint size);
 
+ERTS_GLB_INLINE void erts_schedule_db_free(DbTableCommon* tab,
+                                           void (*free_func)(void *),
+                                           void *ptr,
+                                           ErtsThrPrgrLaterOp *lop,
+                                           Uint size);
+
 ERTS_GLB_INLINE void erts_db_free_nt(ErtsAlcType_t type,
 				     void *ptr,
 				     Uint size);
@@ -296,11 +310,31 @@ erts_db_free(ErtsAlcType_t type, DbTable *tab, void *ptr, Uint size)
     ASSERT(ptr != 0);
     ASSERT(size == ERTS_ALC_DBG_BLK_SZ(ptr));
     ERTS_DB_ALC_MEM_UPDATE_(tab, size, 0);
+    ASSERT(((void *) tab) != ptr ||
+           tab->common.counters.is_decentralized ||
+           0 == erts_flxctr_read_centralized(&tab->common.counters,
+                                             ERTS_DB_TABLE_MEM_COUNTER_ID));
+    erts_free(type, ptr);
+}
 
-    ASSERT(((void *) tab) != ptr
-	   || erts_atomic_read_nob(&tab->common.memory_size) == 0);
+ERTS_GLB_INLINE void
+erts_schedule_db_free(DbTableCommon* tab,
+                      void (*free_func)(void *),
+                      void *ptr,
+                      ErtsThrPrgrLaterOp *lop,
+                      Uint size)
+{
+    ASSERT(ptr != 0);
+    ASSERT(((void *) tab) != ptr);
+    ASSERT(size == ERTS_ALC_DBG_BLK_SZ(ptr));
 
-    erts_free(type, ptr);
+    /*
+     * We update table memory stats here as table may already be gone
+     * when 'free_func' is finally called.
+     */
+    ERTS_DB_ALC_MEM_UPDATE_((DbTable*)tab, size, 0);
+
+    erts_schedule_thr_prgr_later_cleanup_op(free_func, ptr, lop, size);
 }
 
 ERTS_GLB_INLINE void
diff --git a/erts/emulator/beam/erl_db_catree.c b/erts/emulator/beam/erl_db_catree.c
new file mode 100644
index 0000000000..8a89eb72df
--- /dev/null
+++ b/erts/emulator/beam/erl_db_catree.c
@@ -0,0 +1,2449 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB and Kjell Winblad 1998-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+/*
+ * Description: Implementation of ETS ordered_set table type with
+ *              fine-grained synchronization.
+ *
+ * Author: 	Kjell Winblad
+ *
+ * This implementation is based on the contention adapting search tree
+ * (CA tree). The CA tree is a concurrent data structure that
+ * dynamically adapts its synchronization granularity based on how
+ * much contention is detected in locks. The following publication
+ * contains a detailed description of CA trees:
+ * 
+ * A Contention Adapting Approach to Concurrent Ordered Sets
+ * Journal of Parallel and Distributed Computing, 2018
+ * Kjell Winblad and Konstantinos Sagonas
+ * https://doi.org/10.1016/j.jpdc.2017.11.007
+ *
+ * The following publication may also be interesting as it discusses
+ * how the CA tree can be used as an ETS ordered_set table type
+ * backend:
+ *
+ * More Scalable Ordered Set for ETS Using Adaptation
+ * In Thirteenth ACM SIGPLAN workshop on Erlang (2014)
+ * Kjell Winblad and Konstantinos Sagonas
+ * https://doi.org/10.1145/2633448.2633455
+ *
+ * This implementation of the ordered_set ETS table type is only
+ * activated when the options {write_concurrency, true}, public and
+ * ordered_set are passed to the ets:new/2 function. This
+ * implementation is expected to scale better than the default
+ * implementation located in "erl_db_tree.c".
+ * 
+ * The default implementation has a static stack optimization (see
+ * get_static_stack in erl_db_tree.c). This implementation does not
+ * have such an optimization as it induces bad scalability when
+ * concurrent read operations are frequent (they all try to get hold
+ * of the same stack). The default implementation may thus perform
+ * better compared to this implementation in scenarios where the
+ * static stack optimization is useful. One such scenario is when only
+ * one process is accessing the table and this process is traversing
+ * the table with a sequence of next/2 calls.
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include "sys.h"
+#include "erl_vm.h"
+#include "global.h"
+#include "erl_process.h"
+#include "error.h"
+#define ERTS_WANT_DB_INTERNAL__
+#include "erl_db.h"
+#include "bif.h"
+#include "big.h"
+#include "erl_binary.h"
+
+#include "erl_db_catree.h"
+#include "erl_db_tree.h"
+#include "erl_db_tree_util.h"
+
+#ifdef DEBUG
+#  define IF_DEBUG(X) X
+#else
+#  define IF_DEBUG(X)
+#endif
+
+/*
+** Forward declarations
+*/
+
+static SWord do_free_base_node_cont(DbTableCATree *tb, SWord num_left);
+static SWord do_free_routing_nodes_catree_cont(DbTableCATree *tb, SWord num_left);
+static DbTableCATreeNode *catree_first_base_node_from_free_list(DbTableCATree *tb);
+
+/* Method interface functions */
+static int db_first_catree(Process *p, DbTable *tbl,
+                           Eterm *ret);
+static int db_next_catree(Process *p, DbTable *tbl,
+                          Eterm key, Eterm *ret);
+static int db_last_catree(Process *p, DbTable *tbl,
+                          Eterm *ret);
+static int db_prev_catree(Process *p, DbTable *tbl,
+                          Eterm key,
+                          Eterm *ret);
+static int db_put_catree(DbTable *tbl, Eterm obj, int key_clash_fail);
+static int db_get_catree(Process *p, DbTable *tbl,
+                         Eterm key,  Eterm *ret);
+static int db_member_catree(DbTable *tbl, Eterm key, Eterm *ret);
+static int db_get_element_catree(Process *p, DbTable *tbl,
+                                 Eterm key,int ndex,
+                                 Eterm *ret);
+static int db_erase_catree(DbTable *tbl, Eterm key, Eterm *ret);
+static int db_erase_object_catree(DbTable *tbl, Eterm object,Eterm *ret);
+static int db_slot_catree(Process *p, DbTable *tbl,
+                          Eterm slot_term,  Eterm *ret);
+static int db_select_catree(Process *p, DbTable *tbl, Eterm tid,
+                            Eterm pattern, int reversed, Eterm *ret,
+                            enum DbIterSafety);
+static int db_select_count_catree(Process *p, DbTable *tbl, Eterm tid,
+                                  Eterm pattern,  Eterm *ret, enum DbIterSafety);
+static int db_select_chunk_catree(Process *p, DbTable *tbl, Eterm tid,
+                                  Eterm pattern, Sint chunk_size,
+                                  int reversed, Eterm *ret, enum DbIterSafety);
+static int db_select_continue_catree(Process *p, DbTable *tbl,
+                                     Eterm continuation, Eterm *ret,
+                                     enum DbIterSafety*);
+static int db_select_count_continue_catree(Process *p, DbTable *tbl,
+                                           Eterm continuation, Eterm *ret,
+                                           enum DbIterSafety*);
+static int db_select_delete_catree(Process *p, DbTable *tbl, Eterm tid,
+                                   Eterm pattern,  Eterm *ret,
+                                   enum DbIterSafety);
+static int db_select_delete_continue_catree(Process *p, DbTable *tbl, 
+                                            Eterm continuation, Eterm *ret,
+                                            enum DbIterSafety*);
+static int db_select_replace_catree(Process *p, DbTable *tbl, Eterm tid,
+                                    Eterm pattern, Eterm *ret,
+                                    enum DbIterSafety);
+static int db_select_replace_continue_catree(Process *p, DbTable *tbl,
+                                             Eterm continuation, Eterm *ret,
+                                             enum DbIterSafety*);
+static int db_take_catree(Process *, DbTable *, Eterm, Eterm *);
+static void db_print_catree(fmtfn_t to, void *to_arg,
+                            int show, DbTable *tbl);
+static int db_free_table_catree(DbTable *tbl);
+static SWord db_free_table_continue_catree(DbTable *tbl, SWord);
+static void db_foreach_offheap_catree(DbTable *,
+                                      void (*)(ErlOffHeap *, void *),
+                                      void *);
+static SWord db_delete_all_objects_catree(Process* p,
+                                          DbTable* tbl,
+                                          SWord reds,
+                                          Eterm* nitems_holder_wb);
+static Eterm db_delete_all_objects_get_nitems_from_holder_catree(Process* p,
+                                                                 Eterm nitems_holder);
+static int
+db_lookup_dbterm_catree(Process *, DbTable *, Eterm key, Eterm obj,
+                        DbUpdateHandle*);
+static void db_finalize_dbterm_catree(int cret, DbUpdateHandle *);
+
+static void split_catree(DbTableCATree *tb,
+                         DbTableCATreeNode* ERTS_RESTRICT base,
+                         DbTableCATreeNode* ERTS_RESTRICT parent);
+static void join_catree(DbTableCATree *tb,
+                        DbTableCATreeNode *thiz,
+                        DbTableCATreeNode *parent);
+static ERTS_INLINE
+int try_wlock_base_node(DbTableCATreeBaseNode *base_node);
+static ERTS_INLINE
+void wunlock_base_node(DbTableCATreeNode *base_node);
+static ERTS_INLINE
+void wlock_base_node_no_stats(DbTableCATreeNode *base_node);
+static ERTS_INLINE
+void wunlock_adapt_base_node(DbTableCATree* tb,
+                             DbTableCATreeNode* node,
+                             DbTableCATreeNode* parent,
+                             int current_level);
+/*
+** External interface
+*/
+DbTableMethod db_catree =
+{
+    db_create_catree,
+    db_first_catree,
+    db_next_catree,
+    db_last_catree,
+    db_prev_catree,
+    db_put_catree,
+    db_get_catree,
+    db_get_element_catree,
+    db_member_catree,
+    db_erase_catree,
+    db_erase_object_catree,
+    db_slot_catree,
+    db_select_chunk_catree,
+    db_select_catree,
+    db_select_delete_catree,
+    db_select_continue_catree,
+    db_select_delete_continue_catree,
+    db_select_count_catree,
+    db_select_count_continue_catree,
+    db_select_replace_catree,
+    db_select_replace_continue_catree,
+    db_take_catree,
+    db_delete_all_objects_catree,
+    db_delete_all_objects_get_nitems_from_holder_catree,
+    db_free_table_catree,
+    db_free_table_continue_catree,
+    db_print_catree,
+    db_foreach_offheap_catree,
+    db_lookup_dbterm_catree,
+    db_finalize_dbterm_catree
+
+};
+
+/*
+ * Constants
+ */
+
+#define ERL_DB_CATREE_LOCK_FAILURE_CONTRIBUTION 250
+#define ERL_DB_CATREE_LOCK_SUCCESS_CONTRIBUTION (-1)
+#define ERL_DB_CATREE_LOCK_GRAVITY_CONTRIBUTION (-500)
+#define ERL_DB_CATREE_LOCK_GRAVITY_PATTERN (0xFF800000)
+#define ERL_DB_CATREE_LOCK_MORE_THAN_ONE_CONTRIBUTION (-10)
+#define ERL_DB_CATREE_HIGH_CONTENTION_LIMIT 1000
+#define ERL_DB_CATREE_LOW_CONTENTION_LIMIT (-1000)
+#define ERL_DB_CATREE_MAX_ROUTE_NODE_LAYER_HEIGHT 16
+#define ERL_DB_CATREE_LOCK_LOW_NO_CONTRIBUTION_LIMIT (-20000)
+#define ERL_DB_CATREE_LOCK_HIGH_NO_CONTRIBUTION_LIMIT (20000)
+
+/*
+ * Internal CA tree related helper functions and macros
+ */
+
+#define GET_ROUTE_NODE_KEY(node) (node->u.route.key.term)
+#define GET_BASE_NODE_LOCK(node) (&(node->u.base.lock))
+#define GET_ROUTE_NODE_LOCK(node) (&(node->u.route.lock))
+
+
+/* Helpers for reading and writing shared atomic variables */
+
+/* No memory barrier */
+#define GET_ROOT(tb) ((DbTableCATreeNode*)erts_atomic_read_nob(&((tb)->root)))
+#define GET_LEFT(ca_tree_route_node) ((DbTableCATreeNode*)erts_atomic_read_nob(&(ca_tree_route_node->u.route.left)))
+#define GET_RIGHT(ca_tree_route_node) ((DbTableCATreeNode*)erts_atomic_read_nob(&(ca_tree_route_node->u.route.right)))
+#define SET_ROOT(tb, v) erts_atomic_set_nob(&((tb)->root), (erts_aint_t)(v))
+#define SET_LEFT(ca_tree_route_node, v) erts_atomic_set_nob(&(ca_tree_route_node->u.route.left), (erts_aint_t)(v));
+#define SET_RIGHT(ca_tree_route_node, v) erts_atomic_set_nob(&(ca_tree_route_node->u.route.right), (erts_aint_t)(v));
+
+
+/* Release or acquire barriers */
+#define GET_ROOT_ACQB(tb) ((DbTableCATreeNode*)erts_atomic_read_acqb(&((tb)->root)))
+#define GET_LEFT_ACQB(ca_tree_route_node) ((DbTableCATreeNode*)erts_atomic_read_acqb(&(ca_tree_route_node->u.route.left)))
+#define GET_RIGHT_ACQB(ca_tree_route_node) ((DbTableCATreeNode*)erts_atomic_read_acqb(&(ca_tree_route_node->u.route.right)))
+#define SET_ROOT_RELB(tb, v) erts_atomic_set_relb(&((tb)->root), (erts_aint_t)(v))
+#define SET_LEFT_RELB(ca_tree_route_node, v) erts_atomic_set_relb(&(ca_tree_route_node->u.route.left), (erts_aint_t)(v));
+#define SET_RIGHT_RELB(ca_tree_route_node, v) erts_atomic_set_relb(&(ca_tree_route_node->u.route.right), (erts_aint_t)(v));
+
+/* Change base node lock statistics */
+#define BASE_NODE_STAT_SET(NODE, VALUE) erts_atomic_set_nob(&(NODE)->u.base.lock_statistics, VALUE)
+#define BASE_NODE_STAT_READ(NODE) erts_atomic_read_nob(&(NODE)->u.base.lock_statistics)
+#define BASE_NODE_STAT_ADD(NODE, VALUE)                                 \
+    do {                                                                \
+        Sint v = erts_atomic_read_nob(&((NODE)->u.base.lock_statistics)); \
+        ASSERT(VALUE > 0);                                              \
+        if(v < ERL_DB_CATREE_LOCK_HIGH_NO_CONTRIBUTION_LIMIT) {          \
+            erts_atomic_set_nob(&(NODE->u.base.lock_statistics), v + VALUE); \
+        }                                                               \
+    }while(0);
+#define BASE_NODE_STAT_SUB(NODE, VALUE)                                 \
+    do {                                                                \
+        Sint v = erts_atomic_read_nob(&((NODE)->u.base.lock_statistics)); \
+        ASSERT(VALUE < 0);                                              \
+        if(v > ERL_DB_CATREE_LOCK_LOW_NO_CONTRIBUTION_LIMIT) {          \
+            erts_atomic_set_nob(&(NODE->u.base.lock_statistics), v + VALUE); \
+        }                                                               \
+    }while(0);
+
+
+/* Compares a key to the key in a route node */
+static ERTS_INLINE Sint cmp_key_route(Eterm key,
+                                      DbTableCATreeNode *obj)
+{
+    return CMP(key, GET_ROUTE_NODE_KEY(obj));
+}
+
+/*
+ * Used by the split_tree function
+ */
+static ERTS_INLINE
+int less_than_two_elements(TreeDbTerm *root)
+{
+    return root == NULL || (root->left == NULL && root->right == NULL);
+}
+
+/*
+ * Inserts a TreeDbTerm into a tree. Returns the new root.
+ */
+static ERTS_INLINE
+TreeDbTerm* insert_TreeDbTerm(DbTableCATree *tb,
+                              TreeDbTerm *insert_to_root,
+                              TreeDbTerm *value_to_insert) {
+    /* Non recursive insertion in AVL tree, building our own stack */
+    TreeDbTerm **tstack[STACK_NEED];
+    int tpos = 0;
+    int dstack[STACK_NEED+1];
+    int dpos = 0;
+    int state = 0;
+    TreeDbTerm * base = insert_to_root;
+    TreeDbTerm **this = &base;
+    Sint c;
+    Eterm key;
+    int dir;
+    TreeDbTerm *p1, *p2, *p;
+
+    key = GETKEY(tb, value_to_insert->dbterm.tpl);
+
+    dstack[dpos++] = DIR_END;
+    for (;;)
+	if (!*this) { /* Found our place */
+	    state = 1;
+	    *this = value_to_insert;
+	    (*this)->balance = 0;
+	    (*this)->left = (*this)->right = NULL;
+	    break;
+	} else if ((c = cmp_key(&tb->common, key, *this)) < 0) {
+	    /* go lefts */
+	    dstack[dpos++] = DIR_LEFT;
+	    tstack[tpos++] = this;
+	    this = &((*this)->left);
+	} else { /* go right */
+	    dstack[dpos++] = DIR_RIGHT;
+	    tstack[tpos++] = this;
+	    this = &((*this)->right);
+	}
+
+    while (state && ( dir = dstack[--dpos] ) != DIR_END) {
+	this = tstack[--tpos];
+	p = *this;
+	if (dir == DIR_LEFT) {
+	    switch (p->balance) {
+	    case 1:
+		p->balance = 0;
+		state = 0;
+		break;
+	    case 0:
+		p->balance = -1;
+		break;
+	    case -1: /* The icky case */
+		p1 = p->left;
+		if (p1->balance == -1) { /* Single LL rotation */
+		    p->left = p1->right;
+		    p1->right = p;
+		    p->balance = 0;
+		    (*this) = p1;
+		} else { /* Double RR rotation */
+		    p2 = p1->right;
+		    p1->right = p2->left;
+		    p2->left = p1;
+		    p->left = p2->right;
+		    p2->right = p;
+		    p->balance = (p2->balance == -1) ? +1 : 0;
+		    p1->balance = (p2->balance == 1) ? -1 : 0;
+		    (*this) = p2;
+		}
+		(*this)->balance = 0;
+		state = 0;
+		break;
+	    }
+	} else { /* dir == DIR_RIGHT */
+	    switch (p->balance) {
+	    case -1:
+		p->balance = 0;
+		state = 0;
+		break;
+	    case 0:
+		p->balance = 1;
+		break;
+	    case 1:
+		p1 = p->right;
+		if (p1->balance == 1) { /* Single RR rotation */
+		    p->right = p1->left;
+		    p1->left = p;
+		    p->balance = 0;
+		    (*this) = p1;
+		} else { /* Double RL rotation */
+		    p2 = p1->left;
+		    p1->left = p2->right;
+		    p2->right = p1;
+		    p->right = p2->left;
+		    p2->left = p;
+		    p->balance = (p2->balance == 1) ? -1 : 0;
+		    p1->balance = (p2->balance == -1) ? 1 : 0;
+		    (*this) = p2;
+		}
+		(*this)->balance = 0;
+		state = 0;
+		break;
+	    }
+	}
+    }
+    return base;
+}
+
+/*
+ * Split an AVL tree into two trees. The function stores the node
+ * containing the "split key" in the write back parameter
+ * split_key_wb. The function stores the left tree containing the keys
+ * that are smaller than the "split key" in the write back parameter
+ * left_wb and the tree containing the rest of the keys in the write
+ * back parameter right_wb.
+ */
+static void split_tree(DbTableCATree *tb,
+                       TreeDbTerm *root,
+                       TreeDbTerm **split_key_node_wb,
+                       TreeDbTerm **left_wb,
+                       TreeDbTerm **right_wb) {
+    TreeDbTerm * split_node = NULL;
+    TreeDbTerm * left_root;
+    TreeDbTerm * right_root;
+    if (root->left == NULL) { /* To get non empty split */
+        *right_wb = root->right;
+        *split_key_node_wb = root->right;
+        root->right = NULL;
+        root->balance = 0;
+        *left_wb = root;
+        return;
+    }
+    split_node = root;
+    left_root = split_node->left;
+    split_node->left = NULL;
+    right_root = split_node->right;
+    split_node->right = NULL;
+    right_root = insert_TreeDbTerm(tb, right_root, split_node);
+    *split_key_node_wb = split_node;
+    *left_wb = left_root;
+    *right_wb = right_root;
+}
+
+/*
+ * Used by the join_trees function
+ */
+static ERTS_INLINE int compute_tree_hight(TreeDbTerm * root)
+{
+    if(root == NULL) {
+        return 0;
+    } else {
+        TreeDbTerm * current_node = root;
+        int hight_so_far = 1;
+        while (current_node->left != NULL || current_node->right != NULL) {
+            if (current_node->balance == -1) {
+                current_node = current_node->left;
+            } else {
+                current_node = current_node->right;
+            }
+            hight_so_far = hight_so_far + 1;
+        }
+        return hight_so_far;
+    }
+}
+
+/*
+ * Used by the join_trees function
+ */
+static ERTS_INLINE
+TreeDbTerm* linkout_min_or_max_tree_node(TreeDbTerm **root, int is_min)
+{
+    TreeDbTerm **tstack[STACK_NEED];
+    int tpos = 0;
+    int dstack[STACK_NEED+1];
+    int dpos = 0;
+    int state = 0;
+    TreeDbTerm **this = root;
+    int dir;
+    TreeDbTerm *q = NULL;
+
+    dstack[dpos++] = DIR_END;
+    for (;;) {
+        if (!*this) { /* Failure */
+            return NULL;
+        } else if (is_min && (*this)->left != NULL) {
+            dstack[dpos++] = DIR_LEFT;
+            tstack[tpos++] = this;
+            this = &((*this)->left);
+        } else if (!is_min && (*this)->right != NULL) {
+            dstack[dpos++] = DIR_RIGHT;
+            tstack[tpos++] = this;
+            this = &((*this)->right);
+        } else { /* Min value, found the one to splice out */
+            q = (*this);
+            if (q->right == NULL) {
+                (*this) = q->left;
+                state = 1;
+            } else if (q->left == NULL) {
+                (*this) = q->right;
+                state = 1;
+            }
+            break;
+        }
+    }
+    while (state && ( dir = dstack[--dpos] ) != DIR_END) {
+        this = tstack[--tpos];
+        if (dir == DIR_LEFT) {
+            state = tree_balance_left(this);
+        } else {
+            state = tree_balance_right(this);
+        }
+    }
+    return q;
+}
+
+#define LINKOUT_MIN_TREE_NODE(root) linkout_min_or_max_tree_node(root, 1)
+#define LINKOUT_MAX_TREE_NODE(root) linkout_min_or_max_tree_node(root, 0)
+
+/*
+ * Joins two AVL trees where all the keys in the left one are smaller
+ * then the keys in the right one and returns the resulting tree.
+ *
+ * The algorithm is described on page 474 in D. E. Knuth. The Art of
+ * Computer Programming: Sorting and Searching,
+ * vol. 3. Addison-Wesley, 2nd edition, 1998.
+ */
+static TreeDbTerm* join_trees(TreeDbTerm *left_root_param,
+                               TreeDbTerm *right_root_param)
+{
+    TreeDbTerm **tstack[STACK_NEED];
+    int tpos = 0;
+    int dstack[STACK_NEED+1];
+    int dpos = 0;
+    int state = 1;
+    TreeDbTerm **this;
+    int dir;
+    TreeDbTerm *p1, *p2, *p;
+    TreeDbTerm *left_root = left_root_param;
+    TreeDbTerm *right_root = right_root_param;
+    int left_height;
+    int right_height;
+    int current_height;
+    dstack[dpos++] = DIR_END;
+    if (left_root == NULL) {
+        return right_root;
+    } else if (right_root == NULL) {
+        return left_root;
+    }
+
+    left_height = compute_tree_hight(left_root);
+    right_height = compute_tree_hight(right_root);
+    if (left_height >= right_height) {
+        TreeDbTerm * new_root =
+            LINKOUT_MIN_TREE_NODE(&right_root);
+        int new_right_height = compute_tree_hight(right_root);
+        TreeDbTerm * current_node = left_root;
+        this = &left_root;
+        current_height = left_height;
+        while(current_height > new_right_height + 1) {
+            if (current_node->balance == -1) {
+                current_height = current_height - 2;
+            } else {
+                current_height = current_height - 1;
+            }
+            dstack[dpos++] = DIR_RIGHT;
+            tstack[tpos++] = this;
+            this = &((*this)->right);
+            current_node = current_node->right;
+        }
+        new_root->left = current_node;
+        new_root->right = right_root;
+        new_root->balance = new_right_height - current_height;
+        *this = new_root;
+    } else {
+        /* This case is symmetric to the previous case */
+        TreeDbTerm * new_root =
+            LINKOUT_MAX_TREE_NODE(&left_root);
+        int new_left_height = compute_tree_hight(left_root);
+        TreeDbTerm * current_node = right_root;
+        this = &right_root;
+        current_height = right_height;
+        while (current_height > new_left_height + 1) {
+            if (current_node->balance == 1) {
+                current_height = current_height - 2;
+            } else {
+                current_height = current_height - 1;
+            }
+            dstack[dpos++] = DIR_LEFT;
+            tstack[tpos++] = this;
+            this = &((*this)->left);
+            current_node = current_node->left;
+        }
+        new_root->right = current_node;
+        new_root->left = left_root;
+        new_root->balance = current_height - new_left_height;
+        *this = new_root;
+    }
+    /* Now we need to continue as if this was during the insert */
+    while (state && ( dir = dstack[--dpos] ) != DIR_END) {
+        this = tstack[--tpos];
+        p = *this;
+        if (dir == DIR_LEFT) {
+            switch (p->balance) {
+            case 1:
+                p->balance = 0;
+                state = 0;
+                break;
+            case 0:
+                p->balance = -1;
+                break;
+            case -1: /* The icky case */
+                p1 = p->left;
+                if (p1->balance == -1) { /* Single LL rotation */
+                    p->left = p1->right;
+                    p1->right = p;
+                    p->balance = 0;
+                    (*this) = p1;
+                } else { /* Double RR rotation */
+                    p2 = p1->right;
+                    p1->right = p2->left;
+                    p2->left = p1;
+                    p->left = p2->right;
+                    p2->right = p;
+                    p->balance = (p2->balance == -1) ? +1 : 0;
+                    p1->balance = (p2->balance == 1) ? -1 : 0;
+                    (*this) = p2;
+                }
+                (*this)->balance = 0;
+                state = 0;
+                break;
+            }
+        } else { /* dir == DIR_RIGHT */
+            switch (p->balance) {
+            case -1:
+                p->balance = 0;
+                state = 0;
+                break;
+            case 0:
+                p->balance = 1;
+                break;
+            case 1:
+                p1 = p->right;
+                if (p1->balance == 1) { /* Single RR rotation */
+                    p->right = p1->left;
+                    p1->left = p;
+                    p->balance = 0;
+                    (*this) = p1;
+                } else { /* Double RL rotation */
+                    p2 = p1->left;
+                    p1->left = p2->right;
+                    p2->right = p1;
+                    p->right = p2->left;
+                    p2->left = p;
+                    p->balance = (p2->balance == 1) ? -1 : 0;
+                    p1->balance = (p2->balance == -1) ? 1 : 0;
+                    (*this) = p2;
+                }
+                (*this)->balance = 0;
+                state = 0;
+                break;
+            }
+        }
+    }
+    /* Return the joined tree */
+    if (left_height >= right_height) {
+        return left_root;
+    } else {
+        return right_root;
+    }
+}
+
+#ifdef DEBUG
+#  define PROVOKE_RANDOM_SPLIT_JOIN
+#endif
+#ifdef PROVOKE_RANDOM_SPLIT_JOIN
+static int dbg_fastrand(void)
+{
+    static int g_seed = 648835;
+    g_seed = (214013*g_seed+2531011);
+    return (g_seed>>16)&0x7FFF;
+}
+
+static void dbg_provoke_random_splitjoin(DbTableCATree* tb,
+                                         DbTableCATreeNode* base_node)
+{
+    if (tb->common.status & DB_CATREE_FORCE_SPLIT ||
+        !(tb->common.status & DB_CATREE_DEBUG_RANDOM_SPLIT_JOIN))
+        return;
+
+    switch (dbg_fastrand() % 8) {
+    case 1:
+        BASE_NODE_STAT_ADD(base_node, 1+ERL_DB_CATREE_HIGH_CONTENTION_LIMIT);
+        break;
+    case 2:
+        BASE_NODE_STAT_SUB(base_node, -1+ERL_DB_CATREE_LOW_CONTENTION_LIMIT);
+        break;
+    }
+}
+#else
+#  define dbg_provoke_random_splitjoin(T,N)
+#endif /* PROVOKE_RANDOM_SPLIT_JOIN */
+
+static ERTS_NOINLINE
+void do_random_join(DbTableCATree* tb, Uint rand)
+{
+    DbTableCATreeNode* node = GET_ROOT_ACQB(tb);
+    DbTableCATreeNode* parent = NULL;
+    int level = 0;
+    Sint stat;
+    while (!node->is_base_node) {
+        parent = node;
+        if ((rand & (1 << level)) == 0) {
+            node = GET_LEFT_ACQB(node);
+        } else {
+            node = GET_RIGHT_ACQB(node);
+        }
+        level++;
+    }
+    BASE_NODE_STAT_SUB(node, ERL_DB_CATREE_LOCK_GRAVITY_CONTRIBUTION);
+    stat = BASE_NODE_STAT_READ(node);
+    if (stat >= ERL_DB_CATREE_LOW_CONTENTION_LIMIT &&
+        stat <= ERL_DB_CATREE_HIGH_CONTENTION_LIMIT) {
+        return; /* No adaptation */
+    }
+    if (parent != NULL && !try_wlock_base_node(&node->u.base)) {
+        if (!node->u.base.is_valid) {
+            wunlock_base_node(node);
+            return;
+        }
+        wunlock_adapt_base_node(tb, node, parent, level);
+    }
+}
+
+static ERTS_INLINE
+void do_random_join_with_low_probability(DbTableCATree* tb, Uint seed)
+{
+#ifndef ERTS_DB_CA_TREE_NO_RANDOM_JOIN_WITH_LOW_PROBABILITY
+    Uint32 rand = erts_sched_local_random(seed);
+    if (((rand & ERL_DB_CATREE_LOCK_GRAVITY_PATTERN)) == 0) {
+        do_random_join(tb, rand);
+    }
+#endif
+}
+
+static ERTS_INLINE
+int try_wlock_base_node(DbTableCATreeBaseNode *base_node)
+{
+    return EBUSY == erts_rwmtx_tryrwlock(&base_node->lock);
+}
+
+/*
+ * Locks a base node without adjusting the lock statistics
+ */
+static ERTS_INLINE
+void wlock_base_node_no_stats(DbTableCATreeNode *base_node)
+{
+    ASSERT(base_node->is_base_node);
+    erts_rwmtx_rwlock(&base_node->u.base.lock);
+}
+
+/*
+ * Locks a base node and adjusts the lock statistics according to if
+ * the lock was contended or not
+ */
+static ERTS_INLINE
+void wlock_base_node(DbTableCATreeNode *base_node)
+{
+    ASSERT(base_node->is_base_node);
+    if (try_wlock_base_node(&base_node->u.base)) {
+        /* The lock is contended */
+        wlock_base_node_no_stats(base_node);
+        BASE_NODE_STAT_ADD(base_node, ERL_DB_CATREE_LOCK_FAILURE_CONTRIBUTION);
+    } else {
+        BASE_NODE_STAT_SUB(base_node, ERL_DB_CATREE_LOCK_SUCCESS_CONTRIBUTION);
+    }
+}
+
+static ERTS_INLINE
+void wunlock_base_node(DbTableCATreeNode *base_node)
+{
+    erts_rwmtx_rwunlock(&base_node->u.base.lock);
+}
+
+static ERTS_INLINE
+void wunlock_adapt_base_node(DbTableCATree* tb,
+                             DbTableCATreeNode* node,
+                             DbTableCATreeNode* parent,
+                             int current_level)
+{
+    Sint base_node_lock_stat = BASE_NODE_STAT_READ(node);
+    dbg_provoke_random_splitjoin(tb,node);
+    if ((!node->u.base.root && parent && !(tb->common.status
+                                           & DB_CATREE_FORCE_SPLIT))
+        || base_node_lock_stat < ERL_DB_CATREE_LOW_CONTENTION_LIMIT) {
+        join_catree(tb, node, parent);
+    }
+    else if (base_node_lock_stat > ERL_DB_CATREE_HIGH_CONTENTION_LIMIT
+        && current_level < ERL_DB_CATREE_MAX_ROUTE_NODE_LAYER_HEIGHT) {
+        split_catree(tb, node, parent);
+    }
+    else {
+        wunlock_base_node(node);
+    }
+}
+
+static ERTS_INLINE
+void rlock_base_node(DbTableCATreeNode *base_node)
+{
+    ASSERT(base_node->is_base_node);
+    if (EBUSY == erts_rwmtx_tryrlock(&base_node->u.base.lock)) {
+        /* The lock is contended */
+        BASE_NODE_STAT_ADD(base_node, ERL_DB_CATREE_LOCK_FAILURE_CONTRIBUTION);
+        erts_rwmtx_rlock(&base_node->u.base.lock);
+    }
+}
+
+static ERTS_INLINE
+void runlock_base_node(DbTableCATreeNode *base_node, DbTableCATree* tb)
+{
+    ASSERT(base_node->is_base_node);
+    erts_rwmtx_runlock(&base_node->u.base.lock);
+    do_random_join_with_low_probability(tb, (Uint)base_node);
+}
+
+static ERTS_INLINE
+void runlock_base_node_no_rand(DbTableCATreeNode *base_node)
+{
+    ASSERT(base_node->is_base_node);
+    erts_rwmtx_runlock(&base_node->u.base.lock);
+}
+
+static ERTS_INLINE
+void lock_route_node(DbTableCATreeNode *route_node)
+{
+    ASSERT(!route_node->is_base_node);
+    erts_mtx_lock(&route_node->u.route.lock);
+}
+
+static ERTS_INLINE
+void unlock_route_node(DbTableCATreeNode *route_node)
+{
+    ASSERT(!route_node->is_base_node);
+    erts_mtx_unlock(&route_node->u.route.lock);
+}
+
+static ERTS_INLINE
+Eterm copy_route_key(DbRouteKey* dst, Eterm key, Uint key_size)
+{
+    dst->size = key_size;
+    if (key_size != 0) {
+        Eterm* hp = &dst->heap[0];
+        ErlOffHeap tmp_offheap;
+        tmp_offheap.first  = NULL;
+        dst->term = copy_struct(key, key_size, &hp, &tmp_offheap);
+        dst->oh = tmp_offheap.first;
+    }
+    else {
+        ASSERT(is_immed(key));
+        dst->term = key;
+        dst->oh = NULL;
+    }
+    return dst->term;
+}
+
+static ERTS_INLINE
+void destroy_route_key(DbRouteKey* key)
+{
+    if (key->oh) {
+        ErlOffHeap oh;
+        oh.first = key->oh;
+        erts_cleanup_offheap(&oh);
+    }
+}
+
+static ERTS_INLINE
+void init_root_iterator(DbTableCATree* tb, CATreeRootIterator* iter,
+                        int read_only)
+{
+    iter->tb = tb;
+    iter->read_only = read_only;
+    iter->locked_bnode = NULL;
+    iter->next_route_key = THE_NON_VALUE;
+    iter->search_key = NULL;
+}
+
+static ERTS_INLINE
+void lock_iter_base_node(CATreeRootIterator* iter,
+                         DbTableCATreeNode *base_node,
+                         DbTableCATreeNode *parent,
+                         int current_level)
+{
+    ASSERT(!iter->locked_bnode);
+    if (iter->read_only)
+        rlock_base_node(base_node);
+    else {
+        wlock_base_node(base_node);
+        iter->bnode_parent = parent;
+        iter->bnode_level = current_level;
+    }
+    iter->locked_bnode = base_node;
+}
+
+static ERTS_INLINE
+void unlock_iter_base_node(CATreeRootIterator* iter)
+{
+    ASSERT(iter->locked_bnode);
+    if (iter->read_only)
+        runlock_base_node(iter->locked_bnode, iter->tb);
+    else if (iter->locked_bnode->u.base.is_valid) {
+        wunlock_adapt_base_node(iter->tb, iter->locked_bnode,
+                                iter->bnode_parent, iter->bnode_level);
+    }
+    else
+        wunlock_base_node(iter->locked_bnode);
+    iter->locked_bnode = NULL;
+}
+
+static ERTS_INLINE
+void destroy_root_iterator(CATreeRootIterator* iter)
+{
+    if (iter->locked_bnode)
+        unlock_iter_base_node(iter);
+    if (iter->search_key) {
+        destroy_route_key(iter->search_key);
+        erts_free(ERTS_ALC_T_DB_TMP, iter->search_key);
+    }
+}
+
+typedef struct
+{
+    DbTableCATreeNode *parent;
+    int current_level;
+} FindBaseNode;
+
+static ERTS_INLINE
+DbTableCATreeNode* find_base_node(DbTableCATree* tb, Eterm key,
+                                  FindBaseNode* fbn)
+{
+    DbTableCATreeNode* ERTS_RESTRICT node = GET_ROOT_ACQB(tb);
+    if (fbn) {
+        fbn->parent = NULL;
+        fbn->current_level = 0;
+    }
+    while (!node->is_base_node) {
+        if (fbn) {
+            fbn->current_level++;
+            fbn->parent = node;
+        }
+        if (cmp_key_route(key, node) < 0) {
+            node = GET_LEFT_ACQB(node);
+        } else {
+            node = GET_RIGHT_ACQB(node);
+        }
+    }
+    return node;
+}
+
+static ERTS_INLINE
+DbTableCATreeNode* find_rlock_valid_base_node(DbTableCATree* tb, Eterm key)
+{
+    DbTableCATreeNode* base_node;
+
+    while (1) {
+        base_node = find_base_node(tb, key, NULL);
+        rlock_base_node(base_node);
+        if (base_node->u.base.is_valid)
+            break;
+        runlock_base_node_no_rand(base_node);
+    }
+    return base_node;
+}
+
+static ERTS_INLINE
+DbTableCATreeNode* find_wlock_valid_base_node(DbTableCATree* tb, Eterm key,
+                                              FindBaseNode* fbn)
+{
+    DbTableCATreeNode* base_node;
+
+    while (1) {
+        base_node = find_base_node(tb, key, fbn);
+        wlock_base_node(base_node);
+        if (base_node->u.base.is_valid)
+            break;
+        wunlock_base_node(base_node);
+    }
+    return base_node;
+}
+
+#ifdef ERTS_ENABLE_LOCK_CHECK
+#  define LC_ORDER(ORDER) ORDER
+#else
+#  define LC_ORDER(ORDER) NIL
+#endif
+
+#define sizeof_base_node() \
+          offsetof(DbTableCATreeNode, u.base.end_of_struct__)
+
+static DbTableCATreeNode *create_base_node(DbTableCATree *tb,
+                                           TreeDbTerm* root)
+{
+    DbTableCATreeNode *p;
+    erts_rwmtx_opt_t rwmtx_opt = ERTS_RWMTX_OPT_DEFAULT_INITER;
+    p = erts_db_alloc(ERTS_ALC_T_DB_TABLE, (DbTable *) tb,
+                      sizeof_base_node());
+
+    p->is_base_node = 1;
+    p->u.base.root = root;
+    if (tb->common.type & DB_FREQ_READ)
+        rwmtx_opt.type = ERTS_RWMTX_TYPE_FREQUENT_READ;
+    if (erts_ets_rwmtx_spin_count >= 0)
+        rwmtx_opt.main_spincount = erts_ets_rwmtx_spin_count;
+
+    erts_rwmtx_init_opt(&p->u.base.lock, &rwmtx_opt,
+                        "erl_db_catree_base_node",
+                        NIL,
+                        ERTS_LOCK_FLAGS_CATEGORY_DB);
+    BASE_NODE_STAT_SET(p, ((tb->common.status & DB_CATREE_FORCE_SPLIT)
+                           ? INT_MAX : 0));
+    p->u.base.is_valid = 1;
+    return p;
+}
+
+static ERTS_INLINE Uint sizeof_route_node(Uint key_size)
+{
+    return (offsetof(DbTableCATreeNode, u.route.key.heap)
+            + key_size*sizeof(Eterm));
+}
+
+static DbTableCATreeNode*
+create_route_node(DbTableCATree *tb,
+                  DbTableCATreeNode *left,
+                  DbTableCATreeNode *right,
+                  DbTerm * keyTerm,
+                  DbTableCATreeNode* lc_parent)
+{
+    Eterm key = GETKEY(tb,keyTerm->tpl);
+    int key_size = size_object(key);
+    DbTableCATreeNode* p = erts_db_alloc(ERTS_ALC_T_DB_TABLE,
+                                         (DbTable *) tb,
+                                         sizeof_route_node(key_size));
+
+    copy_route_key(&p->u.route.key, key, key_size);
+    p->is_base_node = 0;
+    p->u.route.is_valid = 1;
+    erts_atomic_init_nob(&p->u.route.left, (erts_aint_t)left);
+    erts_atomic_init_nob(&p->u.route.right, (erts_aint_t)right);
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    /* Route node lock order is inverse tree depth (from leafs toward root) */
+    p->u.route.lc_order = (lc_parent == NULL ? MAX_SMALL :
+                           lc_parent->u.route.lc_order - 1);
+    /*
+     * This assert may eventually fail as we don't increase 'lc_order' in join
+     * operations when route nodes move up in the tree.
+     * Tough luck if you run a lock-checking VM for such a long time on 32-bit.
+     */
+    ERTS_LC_ASSERT(p->u.route.lc_order >= 0);
+#endif
+    erts_mtx_init(&p->u.route.lock, "erl_db_catree_route_node",
+                  LC_ORDER(make_small(p->u.route.lc_order)),
+                  ERTS_LOCK_FLAGS_CATEGORY_DB);
+    return p;
+}
+
+static void do_free_base_node(void* vptr)
+{
+    DbTableCATreeNode *p = (DbTableCATreeNode *)vptr;
+    ASSERT(p->is_base_node);
+    erts_rwmtx_destroy(&p->u.base.lock);
+    erts_free(ERTS_ALC_T_DB_TABLE, p);
+}
+
+static void free_catree_base_node(DbTableCATree* tb, DbTableCATreeNode* p)
+{
+    ASSERT(p->is_base_node);
+    ERTS_DB_ALC_MEM_UPDATE_(tb, sizeof_base_node(), 0);
+    do_free_base_node(p);
+}
+
+static void do_free_route_node(void *vptr)
+{
+    DbTableCATreeNode *p = (DbTableCATreeNode *)vptr;
+    ASSERT(!p->is_base_node);
+    erts_mtx_destroy(&p->u.route.lock);
+    destroy_route_key(&p->u.route.key);
+    erts_free(ERTS_ALC_T_DB_TABLE, p);
+}
+
+static void free_catree_route_node(DbTableCATree* tb, DbTableCATreeNode* p)
+{
+    ASSERT(!p->is_base_node);
+    ERTS_DB_ALC_MEM_UPDATE_(tb, sizeof_route_node(p->u.route.key.size), 0);
+    do_free_route_node(p);
+}
+
+
+/*
+ * Returns the parent routing node of the specified
+ * route node 'child' if such a parent exists
+ * or NULL if 'child' is attached to the root.
+ */
+static ERTS_INLINE DbTableCATreeNode *
+parent_of(DbTableCATree *tb,
+          DbTableCATreeNode *child)
+{
+    Eterm key = GET_ROUTE_NODE_KEY(child);
+    DbTableCATreeNode *current = GET_ROOT_ACQB(tb);
+    DbTableCATreeNode *prev = NULL;
+
+    while (current != child) {
+        prev = current;
+        if (cmp_key_route(key, current) < 0) {
+            current = GET_LEFT_ACQB(current);
+        } else {
+            current = GET_RIGHT_ACQB(current);
+        }
+    }
+    return prev;
+}
+
+
+static ERTS_INLINE DbTableCATreeNode *
+leftmost_base_node(DbTableCATreeNode *root)
+{
+    DbTableCATreeNode *node = root;
+    while (!node->is_base_node) {
+        node = GET_LEFT_ACQB(node);
+    }
+    return node;
+}
+
+
+static ERTS_INLINE DbTableCATreeNode *
+rightmost_base_node(DbTableCATreeNode *root)
+{
+    DbTableCATreeNode *node = root;
+    while (!node->is_base_node) {
+        node = GET_RIGHT_ACQB(node);
+    }
+    return node;
+}
+
+
+static ERTS_INLINE DbTableCATreeNode *
+leftmost_route_node(DbTableCATreeNode *root)
+{
+    DbTableCATreeNode *node = root;
+    DbTableCATreeNode *prev_node = NULL;
+    while (!node->is_base_node) {
+        prev_node = node;
+        node = GET_LEFT_ACQB(node);
+    }
+    return prev_node;
+}
+
+static ERTS_INLINE DbTableCATreeNode*
+rightmost_route_node(DbTableCATreeNode *root)
+{
+    DbTableCATreeNode * node = root;
+    DbTableCATreeNode * prev_node = NULL;
+    while (!node->is_base_node) {
+        prev_node = node;
+        node = GET_RIGHT_ACQB(node);
+    }
+    return prev_node;
+}
+
+static ERTS_INLINE
+void init_tree_stack(DbTreeStack *stack,
+                     TreeDbTerm **stack_array,
+                     Uint init_slot)
+{
+    stack->array = stack_array;
+    stack->pos = 0;
+    stack->slot = init_slot;
+}
+
+static void join_catree(DbTableCATree *tb,
+                        DbTableCATreeNode *thiz,
+                        DbTableCATreeNode *parent)
+{
+    DbTableCATreeNode *gparent;
+    DbTableCATreeNode *neighbor;
+    DbTableCATreeNode *new_neighbor;
+    DbTableCATreeNode *neighbor_parent;
+
+    ASSERT(thiz->is_base_node);
+    if (parent == NULL) {
+        BASE_NODE_STAT_SET(thiz, 0);
+        wunlock_base_node(thiz);
+        return;
+    }
+    ASSERT(!parent->is_base_node);
+    if (GET_LEFT(parent) == thiz) {
+        neighbor = leftmost_base_node(GET_RIGHT_ACQB(parent));
+        if (try_wlock_base_node(&neighbor->u.base)) {
+            /* Failed to acquire lock */
+            BASE_NODE_STAT_SET(thiz, 0);
+            wunlock_base_node(thiz);
+            return;
+        } else if (!neighbor->u.base.is_valid) {
+            BASE_NODE_STAT_SET(thiz, 0);
+            wunlock_base_node(thiz);
+            wunlock_base_node(neighbor);
+            return;
+        } else {
+            lock_route_node(parent);
+            parent->u.route.is_valid = 0;
+            neighbor->u.base.is_valid = 0;
+            thiz->u.base.is_valid = 0;
+            gparent = NULL;
+            do {
+                if (gparent != NULL) {
+                    unlock_route_node(gparent);
+                }
+                gparent = parent_of(tb, parent);
+                if (gparent != NULL)
+                    lock_route_node(gparent);
+            } while (gparent != NULL && !gparent->u.route.is_valid);
+
+            if (gparent == NULL) {
+                SET_ROOT_RELB(tb, GET_RIGHT(parent));
+            } else if (GET_LEFT(gparent) == parent) {
+                SET_LEFT_RELB(gparent, GET_RIGHT(parent));
+            } else {
+                SET_RIGHT_RELB(gparent, GET_RIGHT(parent));
+            }
+            unlock_route_node(parent);
+            if (gparent != NULL) {
+                unlock_route_node(gparent);
+            }
+            {
+                TreeDbTerm* new_root = join_trees(thiz->u.base.root,
+                                                  neighbor->u.base.root);
+                new_neighbor = create_base_node(tb, new_root);
+            }
+            if (GET_RIGHT(parent) == neighbor) {
+                neighbor_parent = gparent;
+            } else {
+                neighbor_parent = leftmost_route_node(GET_RIGHT(parent));
+            }
+        }
+    } else { /* Symetric case */
+        ASSERT(GET_RIGHT(parent) == thiz);
+        neighbor = rightmost_base_node(GET_LEFT_ACQB(parent));
+        if (try_wlock_base_node(&neighbor->u.base)) {
+            /* Failed to acquire lock */
+            BASE_NODE_STAT_SET(thiz, 0);
+            wunlock_base_node(thiz);
+            return;
+        } else if (!neighbor->u.base.is_valid) {
+            BASE_NODE_STAT_SET(thiz, 0);
+            wunlock_base_node(thiz);
+            wunlock_base_node(neighbor);
+            return;
+        } else {
+            lock_route_node(parent);
+            parent->u.route.is_valid = 0;
+            neighbor->u.base.is_valid = 0;
+            thiz->u.base.is_valid = 0;
+            gparent = NULL;
+            do {
+                if (gparent != NULL) {
+                    unlock_route_node(gparent);
+                }
+                gparent = parent_of(tb, parent);
+                if (gparent != NULL) {
+                    lock_route_node(gparent);
+                } else {
+                    gparent = NULL;
+                }
+            } while (gparent != NULL && !gparent->u.route.is_valid);
+            if (gparent == NULL) {
+                SET_ROOT_RELB(tb, GET_LEFT(parent));
+            } else if (GET_RIGHT(gparent) == parent) {
+                SET_RIGHT_RELB(gparent, GET_LEFT(parent));
+            } else {
+                SET_LEFT_RELB(gparent, GET_LEFT(parent));
+            }
+            unlock_route_node(parent);
+            if (gparent != NULL) {
+                unlock_route_node(gparent);
+            }
+            {
+                TreeDbTerm* new_root = join_trees(neighbor->u.base.root,
+                                                  thiz->u.base.root);
+                new_neighbor = create_base_node(tb, new_root);
+            }
+            if (GET_LEFT(parent) == neighbor) {
+                neighbor_parent = gparent;
+            } else {
+                neighbor_parent =
+                    rightmost_route_node(GET_LEFT(parent));
+            }
+        }
+    }
+    /* Link in new neighbor and free nodes that are no longer in the tree */
+    if (neighbor_parent == NULL) {
+        SET_ROOT_RELB(tb, new_neighbor);
+    } else if (GET_LEFT(neighbor_parent) == neighbor) {
+        SET_LEFT_RELB(neighbor_parent, new_neighbor);
+    } else {
+        SET_RIGHT_RELB(neighbor_parent, new_neighbor);
+    }
+    wunlock_base_node(thiz);
+    wunlock_base_node(neighbor);
+    /* Free the parent and base */
+    erts_schedule_db_free(&tb->common,
+                          do_free_route_node,
+                          parent,
+                          &parent->u.route.free_item,
+                          sizeof_route_node(parent->u.route.key.size));
+    erts_schedule_db_free(&tb->common,
+                          do_free_base_node,
+                          thiz,
+                          &thiz->u.base.free_item,
+                          sizeof_base_node());
+    erts_schedule_db_free(&tb->common,
+                          do_free_base_node,
+                          neighbor,
+                          &neighbor->u.base.free_item,
+                          sizeof_base_node());
+}
+
+static void split_catree(DbTableCATree *tb,
+                         DbTableCATreeNode* ERTS_RESTRICT base,
+                         DbTableCATreeNode* ERTS_RESTRICT parent)
+{
+    TreeDbTerm *splitOutWriteBack;
+    DbTableCATreeNode* ERTS_RESTRICT new_left;
+    DbTableCATreeNode* ERTS_RESTRICT new_right;
+    DbTableCATreeNode* ERTS_RESTRICT new_route;
+
+    if (less_than_two_elements(base->u.base.root)) {
+        if (!(tb->common.status & DB_CATREE_FORCE_SPLIT))
+            BASE_NODE_STAT_SET(base, 0);
+        wunlock_base_node(base);
+        return;
+    } else {
+        TreeDbTerm *left_tree;
+        TreeDbTerm *right_tree;
+
+        split_tree(tb, base->u.base.root, &splitOutWriteBack,
+                   &left_tree, &right_tree);
+
+        new_left = create_base_node(tb, left_tree);
+        new_right = create_base_node(tb, right_tree);
+        new_route = create_route_node(tb,
+                                      new_left,
+                                      new_right,
+                                      &splitOutWriteBack->dbterm,
+                                      parent);
+        if (parent == NULL) {
+            SET_ROOT_RELB(tb, new_route);
+        } else if(GET_LEFT(parent) == base) {
+            SET_LEFT_RELB(parent, new_route);
+        } else {
+            SET_RIGHT_RELB(parent, new_route);
+        }
+        base->u.base.is_valid = 0;
+        wunlock_base_node(base);
+        erts_schedule_db_free(&tb->common,
+                              do_free_base_node,
+                              base,
+                              &base->u.base.free_item,
+                              sizeof_base_node());
+    }
+}
+
+/*
+ * Helper functions for removing the table
+ */
+
+static void catree_add_base_node_to_free_list(
+        DbTableCATree *tb,
+        DbTableCATreeNode *base_node_container)
+{
+    base_node_container->u.base.next =
+        tb->base_nodes_to_free_list;
+    tb->base_nodes_to_free_list = base_node_container;
+}
+
+static void catree_deque_base_node_from_free_list(DbTableCATree *tb)
+{
+    if (tb->base_nodes_to_free_list == NULL) {
+        return; /* List empty */
+    } else {
+        DbTableCATreeNode *first = tb->base_nodes_to_free_list;
+        tb->base_nodes_to_free_list = first->u.base.next;
+    }
+}
+
+static DbTableCATreeNode *catree_first_base_node_from_free_list(
+        DbTableCATree *tb)
+{
+    return tb->base_nodes_to_free_list;
+}
+
+static SWord do_free_routing_nodes_catree_cont(DbTableCATree *tb, SWord num_left)
+{
+    DbTableCATreeNode *root;
+    DbTableCATreeNode *p;
+    for (;;) {
+        root = POP_NODE(&tb->free_stack_rnodes);
+    	if (root == NULL) break;
+        else if(root->is_base_node) {
+            catree_add_base_node_to_free_list(tb, root);
+            break;
+        }
+    	for (;;) {
+            if ((GET_LEFT(root) != NULL) &&
+                (p = GET_LEFT(root))->is_base_node) {
+                SET_LEFT(root, NULL);
+                catree_add_base_node_to_free_list(tb, p);
+            } else if ((GET_RIGHT(root) != NULL) &&
+                       (p = GET_RIGHT(root))->is_base_node) {
+                SET_RIGHT(root, NULL);
+                catree_add_base_node_to_free_list(tb, p);
+            } else if ((p = GET_LEFT(root)) != NULL) {
+                SET_LEFT(root, NULL);
+                PUSH_NODE(&tb->free_stack_rnodes, root);
+                root = p;
+            } else if ((p = GET_RIGHT(root)) != NULL) {
+                SET_RIGHT(root, NULL);
+                PUSH_NODE(&tb->free_stack_rnodes, root);
+                root = p;
+            } else {
+                free_catree_route_node(tb, root);
+                if (--num_left >= 0) {
+                    break;
+                } else {
+                    return num_left;	/* Done enough for now */
+                }
+            }
+        }
+    }
+    return num_left;
+}
+
+static SWord do_free_base_node_cont(DbTableCATree *tb, SWord num_left)
+{
+    TreeDbTerm *root;
+    TreeDbTerm *p;
+    DbTableCATreeNode *base_node_container =
+        catree_first_base_node_from_free_list(tb);
+    for (;;) {
+        root = POP_NODE(&tb->free_stack_elems);
+        if (root == NULL) break;
+        for (;;) {
+            if ((p = root->left) != NULL) {
+                root->left = NULL;
+                PUSH_NODE(&tb->free_stack_elems, root);
+                root = p;
+            } else if ((p = root->right) != NULL) {
+                root->right = NULL;
+                PUSH_NODE(&tb->free_stack_elems, root);
+                root = p;
+            } else {
+                DEC_NITEMS((DbTable*)tb);
+                tb->nr_of_deleted_items++;
+                free_term((DbTable*)tb, root);
+                if (--num_left >= 0) {
+                    break;
+                } else {
+                    return num_left;	/* Done enough for now */
+                }
+            }
+        }
+    }
+    catree_deque_base_node_from_free_list(tb);
+    free_catree_base_node(tb, base_node_container);
+    base_node_container = catree_first_base_node_from_free_list(tb);
+    if (base_node_container != NULL) {
+        PUSH_NODE(&tb->free_stack_elems, base_node_container->u.base.root);
+    }
+    return num_left;
+}
+
+
+/*
+** Initialization function
+*/
+
+void db_initialize_catree(void)
+{
+    return;
+};
+
+/*
+** Table interface routines (i.e., what's called by the bif's)
+*/
+
+int db_create_catree(Process *p, DbTable *tbl)
+{
+    DbTableCATree *tb = &tbl->catree;
+    DbTableCATreeNode *root;
+
+    root = create_base_node(tb, NULL);
+    tb->deletion = 0;
+    tb->base_nodes_to_free_list = NULL;
+    tb->nr_of_deleted_items = 0;
+#ifdef DEBUG
+    tbl->common.status |= DB_CATREE_DEBUG_RANDOM_SPLIT_JOIN;
+#endif
+    erts_atomic_init_relb(&(tb->root), (erts_aint_t)root);
+    return DB_ERROR_NONE;
+}
+
+static int db_first_catree(Process *p, DbTable *tbl, Eterm *ret)
+{
+    TreeDbTerm *root;
+    CATreeRootIterator iter;
+    int result;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    root = *catree_find_first_root(&iter);
+    if (!root) {
+        TreeDbTerm **pp = catree_find_next_root(&iter, NULL);
+        root = pp ? *pp : NULL;
+    }
+
+    result = db_first_tree_common(p, tbl, root, ret, NULL);
+
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_next_catree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+{
+    DbTreeStack stack;
+    TreeDbTerm * stack_array[STACK_NEED];
+    TreeDbTerm **rootp;
+    CATreeRootIterator iter;
+    int result;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    iter.next_route_key = key;
+    rootp = catree_find_next_root(&iter, NULL);
+
+    do {
+        init_tree_stack(&stack, stack_array, 0);
+        result = db_next_tree_common(p, tbl, (rootp ? *rootp : NULL), key, ret, &stack);
+        if (result != DB_ERROR_NONE || *ret != am_EOT)
+            break;
+
+        rootp = catree_find_next_root(&iter, NULL);
+    } while (rootp);
+
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_last_catree(Process *p, DbTable *tbl, Eterm *ret)
+{
+    TreeDbTerm *root;
+    CATreeRootIterator iter;
+    int result;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    root = *catree_find_last_root(&iter);
+    if (!root) {
+        TreeDbTerm **pp = catree_find_prev_root(&iter, NULL);
+        root = pp ? *pp : NULL;
+    }
+
+    result = db_last_tree_common(p, tbl, root, ret, NULL);
+
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_prev_catree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+{
+    DbTreeStack stack;
+    TreeDbTerm * stack_array[STACK_NEED];
+    TreeDbTerm **rootp;
+    CATreeRootIterator iter;
+    int result;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    iter.next_route_key = key;
+    rootp = catree_find_prev_root(&iter, NULL);
+
+    do {
+        init_tree_stack(&stack, stack_array, 0);
+        result = db_prev_tree_common(p, tbl, (rootp ? *rootp : NULL), key, ret,
+                                     &stack);
+        if (result != DB_ERROR_NONE || *ret != am_EOT)
+            break;
+        rootp = catree_find_prev_root(&iter, NULL);
+    } while (rootp);
+
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_put_catree(DbTable *tbl, Eterm obj, int key_clash_fail)
+{
+    DbTableCATree *tb = &tbl->catree;
+    Eterm key = GETKEY(&tb->common, tuple_val(obj));
+    FindBaseNode fbn;
+    DbTableCATreeNode* node = find_wlock_valid_base_node(tb, key, &fbn);
+    int result = db_put_tree_common(&tb->common, &node->u.base.root, obj,
+                                    key_clash_fail, NULL);
+    wunlock_adapt_base_node(tb, node, fbn.parent, fbn.current_level);
+    return result;
+}
+
+static int db_get_catree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+{
+    DbTableCATree *tb = &tbl->catree;
+    DbTableCATreeNode* node = find_rlock_valid_base_node(tb, key);
+    int result = db_get_tree_common(p, &tb->common,
+                                    node->u.base.root,
+                                    key, ret, NULL);
+    runlock_base_node(node, tb);
+    return result;
+}
+
+TreeDbTerm** catree_find_root(Eterm key, CATreeRootIterator* iter)
+{
+    FindBaseNode fbn;
+    DbTableCATreeNode* base_node;
+
+    while (1) {
+        base_node = find_base_node(iter->tb, key, &fbn);
+        lock_iter_base_node(iter, base_node, fbn.parent, fbn.current_level);
+        if (base_node->u.base.is_valid)
+            break;
+        unlock_iter_base_node(iter);
+    }
+    return &base_node->u.base.root;
+}
+
+static Eterm save_iter_search_key(CATreeRootIterator* iter, Eterm key)
+{
+    Uint key_size;
+
+    if (is_immed(key))
+        return key;
+
+    if (iter->search_key) {
+        if (key == iter->search_key->term)
+            return key; /* already saved */
+        destroy_route_key(iter->search_key);
+    }
+    key_size = size_object(key);
+    if (!iter->search_key || key_size > iter->search_key->size) {
+        iter->search_key = erts_realloc(ERTS_ALC_T_DB_TMP,
+                                        iter->search_key,
+                                        (offsetof(DbRouteKey, heap)
+                                         + key_size*sizeof(Eterm)));
+    }
+    return copy_route_key(iter->search_key, key, key_size);
+}
+
+TreeDbTerm** catree_find_nextprev_root(CATreeRootIterator *iter,
+                                       int forward,
+                                       Eterm *search_keyp)
+{
+#ifdef DEBUG
+    DbTableCATreeNode *rejected_invalid = NULL;
+    DbTableCATreeNode *rejected_empty = NULL;
+#endif
+    DbTableCATreeNode *node;
+    DbTableCATreeNode *parent;
+    DbTableCATreeNode* next_route_node;
+    Eterm route_key = iter->next_route_key;
+    int current_level;
+
+    if (iter->locked_bnode) {
+        if (search_keyp)
+            *search_keyp = save_iter_search_key(iter, *search_keyp);
+        unlock_iter_base_node(iter);
+    }
+
+    if (is_non_value(route_key))
+        return NULL;
+
+    while (1) {
+        node = GET_ROOT_ACQB(iter->tb);
+        current_level = 0;
+        parent = NULL;
+        next_route_node = NULL;
+        while (!node->is_base_node) {
+            current_level++;
+            parent = node;
+            if (forward) {
+                if (cmp_key_route(route_key,node) < 0) {
+                    next_route_node = node;
+                    node = GET_LEFT_ACQB(node);
+                } else {
+                    node = GET_RIGHT_ACQB(node);
+                }
+            }
+            else {
+                if (cmp_key_route(route_key,node) > 0) {
+                    next_route_node = node;
+                    node = GET_RIGHT_ACQB(node);
+                } else {
+                    node = GET_LEFT_ACQB(node);
+                }
+            }
+        }
+        ASSERT(node != rejected_invalid);
+        lock_iter_base_node(iter, node, parent, current_level);
+        if (node->u.base.is_valid) {
+            ASSERT(node != rejected_empty);
+            if (node->u.base.root) {
+                iter->next_route_key = (next_route_node ?
+                                        next_route_node->u.route.key.term :
+                                        THE_NON_VALUE);
+                iter->locked_bnode = node;
+                return &node->u.base.root;
+            }
+            if (!next_route_node) {
+                unlock_iter_base_node(iter);
+                return NULL;
+            }
+            route_key = next_route_node->u.route.key.term;
+            IF_DEBUG(rejected_empty = node);
+        }
+        else
+            IF_DEBUG(rejected_invalid = node);
+
+        /* Retry */
+        unlock_iter_base_node(iter);
+    }
+}
+
+TreeDbTerm** catree_find_next_root(CATreeRootIterator *iter, Eterm* keyp)
+{
+    return catree_find_nextprev_root(iter, 1, keyp);
+}
+
+TreeDbTerm** catree_find_prev_root(CATreeRootIterator *iter, Eterm* keyp)
+{
+    return catree_find_nextprev_root(iter, 0, keyp);
+}
+
+/* @brief Find root of tree where object with smallest key of all larger than
+ * partially bound key may reside. Can be used as a starting point for
+ * a reverse iteration with pb_key.
+ *
+ * @param pb_key The partially bound key. Example {42, '$1'}
+ * @param iter An initialized root iterator.
+ *
+ * @return Pointer to found root pointer. May not be NULL.
+ */
+TreeDbTerm** catree_find_next_from_pb_key_root(Eterm pb_key,
+                                               CATreeRootIterator* iter)
+{
+#ifdef DEBUG
+    DbTableCATreeNode *rejected_base = NULL;
+#endif
+    DbTableCATreeNode *node;
+    DbTableCATreeNode *parent;
+    DbTableCATreeNode* next_route_node;
+    int current_level;
+
+    ASSERT(!iter->locked_bnode);
+
+    while (1) {
+        node = GET_ROOT_ACQB(iter->tb);
+        current_level = 0;
+        parent = NULL;
+        next_route_node = NULL;
+        while (!node->is_base_node) {
+            current_level++;
+            parent = node;
+            if (cmp_partly_bound(pb_key, GET_ROUTE_NODE_KEY(node)) >= 0) {
+                next_route_node = node;
+                node = GET_RIGHT_ACQB(node);
+            } else {
+                node = GET_LEFT_ACQB(node);
+            }
+        }
+        ASSERT(node != rejected_base);
+        lock_iter_base_node(iter, node, parent, current_level);
+        if (node->u.base.is_valid) {
+            iter->next_route_key = (next_route_node ?
+                                    next_route_node->u.route.key.term :
+                                    THE_NON_VALUE);
+            return &node->u.base.root;
+        }
+        /* Retry */
+        unlock_iter_base_node(iter);
+#ifdef DEBUG
+        rejected_base = node;
+#endif
+    }
+}
+
+/* @brief Find root of tree where object with largest key of all smaller than
+ * partially bound key may reside. Can be used as a starting point for
+ * a forward iteration with pb_key.
+ *
+ * @param pb_key The partially bound key. Example {42, '$1'}
+ * @param iter An initialized root iterator.
+ *
+ * @return Pointer to found root pointer. May not be NULL.
+ */
+TreeDbTerm** catree_find_prev_from_pb_key_root(Eterm key,
+                                               CATreeRootIterator* iter)
+{
+#ifdef DEBUG
+    DbTableCATreeNode *rejected_base = NULL;
+#endif
+    DbTableCATreeNode *node;
+    DbTableCATreeNode *parent;
+    DbTableCATreeNode* next_route_node;
+    int current_level;
+
+    ASSERT(!iter->locked_bnode);
+
+    while (1) {
+        node = GET_ROOT_ACQB(iter->tb);
+        current_level = 0;
+        parent = NULL;
+        next_route_node = NULL;
+        while (!node->is_base_node) {
+            current_level++;
+            parent = node;
+            if (cmp_partly_bound(key, GET_ROUTE_NODE_KEY(node)) <= 0) {
+                next_route_node = node;
+                node = GET_LEFT_ACQB(node);
+            } else {
+                node = GET_RIGHT_ACQB(node);
+            }
+        }
+        ASSERT(node != rejected_base);
+        lock_iter_base_node(iter, node, parent, current_level);
+        if (node->u.base.is_valid) {
+            iter->next_route_key = (next_route_node ?
+                                    next_route_node->u.route.key.term :
+                                    THE_NON_VALUE);
+            return &node->u.base.root;
+        }
+        /* Retry */
+        unlock_iter_base_node(iter);
+#ifdef DEBUG
+        rejected_base = node;
+#endif
+    }
+}
+
+static TreeDbTerm** catree_find_firstlast_root(CATreeRootIterator* iter,
+                                               int first)
+{
+#ifdef DEBUG
+    DbTableCATreeNode *rejected_base = NULL;
+#endif
+    DbTableCATreeNode *node;
+    DbTableCATreeNode* next_route_node;
+    int current_level;
+
+    while (1) {
+        node = GET_ROOT_ACQB(iter->tb);
+        current_level = 0;
+        next_route_node = NULL;
+        while (!node->is_base_node) {
+            current_level++;
+            next_route_node = node;
+            node = first ? GET_LEFT_ACQB(node) : GET_RIGHT_ACQB(node);
+        }
+        ASSERT(node != rejected_base);
+        lock_iter_base_node(iter, node, next_route_node, current_level);
+        if (node->u.base.is_valid) {
+            iter->next_route_key = (next_route_node ?
+                                    next_route_node->u.route.key.term :
+                                    THE_NON_VALUE);
+            return &node->u.base.root;
+        }
+        /* Retry */
+        unlock_iter_base_node(iter);
+#ifdef DEBUG
+        rejected_base = node;
+#endif
+    }
+}
+
+TreeDbTerm** catree_find_first_root(CATreeRootIterator* iter)
+{
+    return catree_find_firstlast_root(iter, 1);
+}
+
+TreeDbTerm** catree_find_last_root(CATreeRootIterator* iter)
+{
+    return catree_find_firstlast_root(iter, 0);
+}
+
+static int db_member_catree(DbTable *tbl, Eterm key, Eterm *ret)
+{
+    DbTableCATree *tb = &tbl->catree;
+    DbTableCATreeNode* node = find_rlock_valid_base_node(tb, key);
+    int result = db_member_tree_common(&tb->common,
+                                       node->u.base.root,
+                                       key, ret, NULL);
+    runlock_base_node(node, tb);
+    return result;
+}
+
+static int db_get_element_catree(Process *p, DbTable *tbl,
+			       Eterm key, int ndex, Eterm *ret)
+{
+    DbTableCATree *tb = &tbl->catree;
+    DbTableCATreeNode* node = find_rlock_valid_base_node(tb, key);
+    int result = db_get_element_tree_common(p, &tb->common,
+                                            node->u.base.root,
+                                            key, ndex, ret, NULL);
+    runlock_base_node(node, tb);
+    return result;
+}
+
+static int db_erase_catree(DbTable *tbl, Eterm key, Eterm *ret)
+{
+    DbTableCATree *tb = &tbl->catree;
+    FindBaseNode fbn;
+    DbTableCATreeNode* node = find_wlock_valid_base_node(tb, key, &fbn);
+    int result = db_erase_tree_common(tbl, &node->u.base.root, key,
+                                      ret, NULL);
+    wunlock_adapt_base_node(tb, node, fbn.parent, fbn.current_level);
+    return result;
+}
+
+static int db_erase_object_catree(DbTable *tbl, Eterm object, Eterm *ret)
+{
+    DbTableCATree *tb = &tbl->catree;
+    Eterm key = GETKEY(&tb->common, tuple_val(object));
+    FindBaseNode fbn;
+    DbTableCATreeNode* node = find_wlock_valid_base_node(tb, key, &fbn);
+    int result = db_erase_object_tree_common(tbl,
+                                             &node->u.base.root,
+                                             object,
+                                             ret,
+                                             NULL);
+    wunlock_adapt_base_node(tb, node, fbn.parent, fbn.current_level);
+    return result;
+}
+
+
+static int db_slot_catree(Process *p, DbTable *tbl,
+                          Eterm slot_term, Eterm *ret)
+{
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    result = db_slot_tree_common(p, tbl, *catree_find_first_root(&iter),
+                                 slot_term, ret, NULL, &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_select_continue_catree(Process *p,
+                                     DbTable *tbl,
+                                     Eterm continuation,
+                                     Eterm *ret,
+                                     enum DbIterSafety* safety_p)
+{
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    result = db_select_continue_tree_common(p, &tbl->common,
+                                            continuation, ret, NULL, &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_select_catree(Process *p, DbTable *tbl, Eterm tid,
+                            Eterm pattern, int reverse, Eterm *ret,
+                            enum DbIterSafety safety)
+{
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    result = db_select_tree_common(p, tbl, tid, pattern, reverse, ret,
+                                   NULL, &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_select_count_continue_catree(Process *p,
+                                           DbTable *tbl,
+                                           Eterm continuation,
+                                           Eterm *ret,
+                                           enum DbIterSafety* safety_p)
+{
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    result = db_select_count_continue_tree_common(p, tbl,
+                                                  continuation, ret, NULL,
+                                                  &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_select_count_catree(Process *p, DbTable *tbl, Eterm tid,
+                                  Eterm pattern, Eterm *ret,
+                                  enum DbIterSafety safety)
+{
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    result = db_select_count_tree_common(p, tbl,
+                                         tid, pattern, ret, NULL, &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_select_chunk_catree(Process *p, DbTable *tbl, Eterm tid,
+                                  Eterm pattern, Sint chunk_size,
+                                  int reversed, Eterm *ret,
+                                  enum DbIterSafety safety)
+{
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    result = db_select_chunk_tree_common(p, tbl,
+                                         tid, pattern, chunk_size, reversed, ret,
+                                         NULL, &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_select_delete_continue_catree(Process *p,
+                                            DbTable *tbl,
+                                            Eterm continuation,
+                                            Eterm *ret,
+                                            enum DbIterSafety* safety_p)
+{
+    DbTreeStack stack;
+    TreeDbTerm * stack_array[STACK_NEED];
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 0);
+    init_tree_stack(&stack, stack_array, 0);
+    result = db_select_delete_continue_tree_common(p, tbl, continuation, ret,
+                                                   &stack, &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_select_delete_catree(Process *p, DbTable *tbl, Eterm tid,
+                                   Eterm pattern, Eterm *ret,
+                                   enum DbIterSafety safety)
+{
+    DbTreeStack stack;
+    TreeDbTerm * stack_array[STACK_NEED];
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 0);
+    init_tree_stack(&stack, stack_array, 0);
+    result = db_select_delete_tree_common(p, tbl,
+                                          tid, pattern, ret, &stack,
+                                          &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_select_replace_catree(Process *p, DbTable *tbl, Eterm tid,
+                                    Eterm pattern, Eterm *ret,
+                                    enum DbIterSafety safety_p)
+{
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 0);
+    result = db_select_replace_tree_common(p, tbl,
+                                           tid, pattern, ret, NULL, &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_select_replace_continue_catree(Process *p, DbTable *tbl,
+                                             Eterm continuation, Eterm *ret,
+                                             enum DbIterSafety* safety_p)
+{
+    int result;
+    CATreeRootIterator iter;
+
+    init_root_iterator(&tbl->catree, &iter, 0);
+    result = db_select_replace_continue_tree_common(p, tbl, continuation, ret,
+                                                    NULL, &iter);
+    destroy_root_iterator(&iter);
+    return result;
+}
+
+static int db_take_catree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+{
+    DbTableCATree *tb = &tbl->catree;
+    FindBaseNode fbn;
+    DbTableCATreeNode* node = find_wlock_valid_base_node(tb, key, &fbn);
+    int result = db_take_tree_common(p, tbl, &node->u.base.root, key,
+                                     ret, NULL);
+    wunlock_adapt_base_node(tb, node, fbn.parent, fbn.current_level);
+    return result;
+}
+
+/*
+** Other interface routines (not directly coupled to one bif)
+*/
+
+
+/* Display tree contents (for dump) */
+static void db_print_catree(fmtfn_t to, void *to_arg,
+                            int show, DbTable *tbl)
+{
+    CATreeRootIterator iter;
+    TreeDbTerm** root;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    root = catree_find_first_root(&iter);
+    do {
+        db_print_tree_common(to, to_arg, show, *root, tbl);
+        root = catree_find_next_root(&iter, NULL);
+    } while (root);
+    destroy_root_iterator(&iter);
+}
+
+/* Release all memory occupied by a single table */
+static int db_free_table_catree(DbTable *tbl)
+{
+    while (db_free_table_continue_catree(tbl, ERTS_SWORD_MAX) < 0)
+	;
+    return 1;
+}
+
+static SWord db_free_table_continue_catree(DbTable *tbl, SWord reds)
+{
+    DbTableCATreeNode *first_base_node;
+    DbTableCATree *tb = &tbl->catree;
+    if (!tb->deletion) {
+        tb->deletion = 1;
+        tb->free_stack_elems.array =
+            erts_db_alloc(ERTS_ALC_T_DB_STK,
+                          (DbTable *) tb,
+                          sizeof(TreeDbTerm *) * STACK_NEED);
+        tb->free_stack_elems.pos = 0;
+        tb->free_stack_elems.slot = 0;
+        tb->free_stack_rnodes.array =
+            erts_db_alloc(ERTS_ALC_T_DB_STK,
+                          (DbTable *) tb,
+                          sizeof(DbTableCATreeNode *) * STACK_NEED);
+        tb->free_stack_rnodes.pos = 0;
+        tb->free_stack_rnodes.size = STACK_NEED;
+        PUSH_NODE(&tb->free_stack_rnodes, GET_ROOT(tb));
+        tb->is_routing_nodes_freed = 0;
+        tb->base_nodes_to_free_list = NULL;
+        tb->nr_of_deleted_items = 0;
+    }
+    if ( ! tb->is_routing_nodes_freed ) {
+        reds = do_free_routing_nodes_catree_cont(tb, reds);
+        if (reds < 0) {
+            return reds; /* Not finished */
+        } else {
+            tb->is_routing_nodes_freed = 1; /* Ready with the routing nodes */
+            first_base_node = catree_first_base_node_from_free_list(tb);
+            PUSH_NODE(&tb->free_stack_elems, first_base_node->u.base.root);
+        }
+    }
+    while (catree_first_base_node_from_free_list(tb) != NULL) {
+        reds = do_free_base_node_cont(tb, reds);
+        if (reds < 0) {
+            return reds; /* Continue later */
+        }
+    }
+    /* Time to free the main structure*/
+    erts_db_free(ERTS_ALC_T_DB_STK,
+                 (DbTable *) tb,
+                 (void *) tb->free_stack_elems.array,
+                 sizeof(TreeDbTerm *) * STACK_NEED);
+    erts_db_free(ERTS_ALC_T_DB_STK,
+                 (DbTable *) tb,
+                 (void *) tb->free_stack_rnodes.array,
+                 sizeof(DbTableCATreeNode *) * STACK_NEED);
+    return 1;
+}
+
+static
+int db_catree_nr_of_items_deleted_wb_dtor(Binary *context_bin) {
+    (void)context_bin;
+    return 1;
+}
+
+typedef struct {
+    Uint nr_of_deleted_items;
+} DbCATreeNrOfItemsDeletedWb;
+
+static Eterm
+create_and_install_num_of_deleted_items_wb_bin(Process *p, DbTableCATree *tb)
+{
+    Binary* bin =
+        erts_create_magic_binary(sizeof(DbCATreeNrOfItemsDeletedWb),
+                                 db_catree_nr_of_items_deleted_wb_dtor);
+    DbCATreeNrOfItemsDeletedWb* data = ERTS_MAGIC_BIN_DATA(bin);
+    Eterm* hp = HAlloc(p, ERTS_MAGIC_REF_THING_SIZE);
+    Eterm mref = erts_mk_magic_ref(&hp, &MSO(p), bin);
+    data->nr_of_deleted_items = 0;
+    tb->nr_of_deleted_items_wb = bin;
+    erts_refc_inctest(&bin->intern.refc, 2);   
+    return mref;
+}
+
+static Eterm db_delete_all_objects_get_nitems_from_holder_catree(Process* p,
+                                                                 Eterm mref)
+{
+    Binary* bin = erts_magic_ref2bin(mref);
+    DbCATreeNrOfItemsDeletedWb* data = ERTS_MAGIC_BIN_DATA(bin);
+    return erts_make_integer(data->nr_of_deleted_items, p);
+}
+
+static SWord db_delete_all_objects_catree(Process* p,
+                                          DbTable* tbl,
+                                          SWord reds,
+                                          Eterm* nitems_holder_wb)
+{
+    DbTableCATree *tb = &tbl->catree;
+    DbCATreeNrOfItemsDeletedWb* data;
+    if (!tb->deletion) {
+        *nitems_holder_wb =
+            create_and_install_num_of_deleted_items_wb_bin(p, tb);
+    }
+    reds = db_free_table_continue_catree(tbl, reds);
+    if (reds < 0)
+        return reds;
+    data = ERTS_MAGIC_BIN_DATA(tb->nr_of_deleted_items_wb);
+    data->nr_of_deleted_items = tb->nr_of_deleted_items;
+    erts_bin_release(tb->nr_of_deleted_items_wb);
+    db_create_catree(p, tbl);
+    return reds;
+}
+
+
+static void do_for_route_nodes(DbTableCATreeNode* node,
+                               void (*func)(ErlOffHeap *, void *),
+                               void *arg)
+{
+    ErlOffHeap tmp_offheap;
+
+    if (!GET_LEFT(node)->is_base_node)
+        do_for_route_nodes(GET_LEFT(node), func, arg);
+
+    tmp_offheap.first = node->u.route.key.oh;
+    tmp_offheap.overhead = 0;
+    (*func)(&tmp_offheap, arg);
+
+    if (!GET_RIGHT(node)->is_base_node)
+        do_for_route_nodes(GET_RIGHT(node), func, arg);
+}
+
+static void db_foreach_offheap_catree(DbTable *tbl,
+                                      void (*func)(ErlOffHeap *, void *),
+                                      void *arg)
+{
+    CATreeRootIterator iter;
+    TreeDbTerm** root;
+
+    init_root_iterator(&tbl->catree, &iter, 1);
+    root = catree_find_first_root(&iter);
+    do {
+        db_foreach_offheap_tree_common(*root, func, arg);
+        root = catree_find_next_root(&iter, NULL);
+    } while (root);
+    destroy_root_iterator(&iter);
+
+    do_for_route_nodes(GET_ROOT(&tbl->catree), func, arg);
+}
+
+static int db_lookup_dbterm_catree(Process *p, DbTable *tbl, Eterm key, Eterm obj,
+                                   DbUpdateHandle *handle)
+{
+    DbTableCATree *tb = &tbl->catree;
+    FindBaseNode fbn;
+    DbTableCATreeNode* node = find_wlock_valid_base_node(tb, key, &fbn);
+    int res = db_lookup_dbterm_tree_common(p, tbl, &node->u.base.root, key,
+                                           obj, handle, NULL);
+    if (res == 0) {
+        wunlock_adapt_base_node(tb, node, fbn.parent, fbn.current_level);
+    } else {
+        /* db_finalize_dbterm_catree will unlock */
+        handle->u.catree.base_node = node;
+        handle->u.catree.parent = fbn.parent;
+        handle->u.catree.current_level = fbn.current_level;
+    }
+    return res;
+}
+
+static void db_finalize_dbterm_catree(int cret, DbUpdateHandle *handle)
+{
+    DbTableCATree *tb = &(handle->tb->catree);
+    db_finalize_dbterm_tree_common(cret, handle, NULL);
+    wunlock_adapt_base_node(tb, handle->u.catree.base_node,
+                            handle->u.catree.parent,
+                            handle->u.catree.current_level);
+    return;
+}
+
+#ifdef ERTS_ENABLE_LOCK_COUNT
+static void erts_lcnt_enable_db_catree_lock_count_helper(DbTableCATree *tb,
+                                                         DbTableCATreeNode *node,
+                                                         int enable)
+{
+    erts_lcnt_ref_t *lcnt_ref;
+    erts_lock_flags_t lock_type;
+    if (node->is_base_node) {
+        lcnt_ref = &GET_BASE_NODE_LOCK(node)->lcnt;
+        lock_type = ERTS_LOCK_TYPE_RWMUTEX;
+    } else {
+        erts_lcnt_enable_db_catree_lock_count_helper(tb, GET_LEFT(node), enable);
+        erts_lcnt_enable_db_catree_lock_count_helper(tb, GET_RIGHT(node), enable);
+        lcnt_ref = &GET_ROUTE_NODE_LOCK(node)->lcnt;
+        lock_type = ERTS_LOCK_TYPE_MUTEX;
+    }
+    if (enable) {
+        erts_lcnt_install_new_lock_info(lcnt_ref, "db_hash_slot", tb->common.the_name,
+                                        lock_type | ERTS_LOCK_FLAGS_CATEGORY_DB);
+    } else {
+        erts_lcnt_uninstall(lcnt_ref);
+    }
+}
+
+void erts_lcnt_enable_db_catree_lock_count(DbTableCATree *tb, int enable)
+{
+    erts_lcnt_enable_db_catree_lock_count_helper(tb, GET_ROOT(tb), enable);
+}
+#endif /* ERTS_ENABLE_LOCK_COUNT */
+
+void db_catree_force_split(DbTableCATree* tb, int on)
+{
+    CATreeRootIterator iter;
+    TreeDbTerm** root;
+
+    init_root_iterator(tb, &iter, 1);
+    root = catree_find_first_root(&iter);
+    do {
+        BASE_NODE_STAT_SET(iter.locked_bnode, (on ? INT_MAX : 0));
+        root = catree_find_next_root(&iter, NULL);
+    } while (root);
+    destroy_root_iterator(&iter);
+
+    if (on)
+        tb->common.status |= DB_CATREE_FORCE_SPLIT;
+    else
+        tb->common.status &= ~DB_CATREE_FORCE_SPLIT;
+}
+
+void db_catree_debug_random_split_join(DbTableCATree* tb, int on)
+{
+    if (on)
+        tb->common.status |= DB_CATREE_DEBUG_RANDOM_SPLIT_JOIN;
+    else
+        tb->common.status &= ~DB_CATREE_DEBUG_RANDOM_SPLIT_JOIN;
+}
+
+void db_calc_stats_catree(DbTableCATree* tb, DbCATreeStats* stats)
+{
+    DbTableCATreeNode* stack[ERL_DB_CATREE_MAX_ROUTE_NODE_LAYER_HEIGHT];
+    DbTableCATreeNode* node;
+    Uint depth = 0;
+
+    stats->route_nodes = 0;
+    stats->base_nodes = 0;
+    stats->max_depth = 0;
+
+    node = GET_ROOT(tb);
+    do {
+        while (!node->is_base_node) {
+            stats->route_nodes++;
+            ASSERT(depth < sizeof(stack)/sizeof(*stack));
+            stack[depth++] = node;  /* PUSH parent */
+            if (stats->max_depth < depth)
+                stats->max_depth = depth;
+            node = GET_LEFT(node);
+        }
+        stats->base_nodes++;
+
+        while (depth > 0) {
+            DbTableCATreeNode* parent = stack[depth-1];
+            if (node == GET_LEFT(parent)) {
+                node = GET_RIGHT(parent);
+                break;
+            }
+            else {
+                ASSERT(node == GET_RIGHT(parent));
+                node = parent;
+                depth--; /* POP parent */
+            }
+        }
+    } while (depth > 0);
+}
+
+struct debug_catree_fa {
+    void (*func)(ErlOffHeap *, void *);
+    void *arg;
+};
+
+static void debug_free_route_node(void *vfap, ErtsThrPrgrVal val, void *vnp)
+{
+    DbTableCATreeNode *np = vnp;
+    if (np->u.route.key.oh) {
+        struct debug_catree_fa *fap = vfap;
+        ErlOffHeap oh;
+        ERTS_INIT_OFF_HEAP(&oh);
+        oh.first = np->u.route.key.oh;
+        (*fap->func)(&oh, fap->arg);
+    }
+}
+
+void
+erts_db_foreach_thr_prgr_offheap_catree(void (*func)(ErlOffHeap *, void *),
+                                        void *arg)
+{
+    struct debug_catree_fa fa;
+    fa.func = func;
+    fa.arg = arg;
+    erts_debug_later_op_foreach(do_free_route_node, debug_free_route_node, &fa);
+}
+
+
+#ifdef HARDDEBUG
+
+/*
+ * Not called, but kept as it might come to use
+ */
+static inline int my_check_table_tree(TreeDbTerm *t)
+{
+    int lh, rh;
+    if (t == NULL)
+	return 0;
+    lh = my_check_table_tree(t->left);
+    rh = my_check_table_tree(t->right);
+    if ((rh - lh) != t->balance) {
+	erts_fprintf(stderr, "Invalid tree balance for this node:\n");
+	erts_fprintf(stderr,"balance = %d, left = 0x%08X, right = 0x%08X\n",
+		     t->balance, t->left, t->right);
+	erts_fprintf(stderr,"\nDump:\n---------------------------------\n");
+	erts_fprintf(stderr,"\n---------------------------------\n");
+        abort();
+    }
+    return ((rh > lh) ? rh : lh) + 1;
+}
+
+#endif
diff --git a/erts/emulator/beam/erl_db_catree.h b/erts/emulator/beam/erl_db_catree.h
new file mode 100644
index 0000000000..2ede85e04e
--- /dev/null
+++ b/erts/emulator/beam/erl_db_catree.h
@@ -0,0 +1,140 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 1998-2016. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+/*
+ * Description: Implementation of ETS ordered_set table type with
+ *              fine-grained synchronization.
+ *
+ * Author: 	Kjell Winblad
+ *
+ * "erl_db_catree.c" contains more details about the implementation.
+ *
+ */
+
+#ifndef _DB_CATREE_H
+#define _DB_CATREE_H
+
+struct DbTableCATreeNode;
+
+typedef struct {
+    Eterm term;
+    struct erl_off_heap_header* oh;
+    Uint size;
+    Eterm heap[1];
+} DbRouteKey;
+
+typedef struct {
+    erts_rwmtx_t lock; /* The lock for this base node */
+    erts_atomic_t lock_statistics;
+    int is_valid; /* If this base node is still valid */
+    TreeDbTerm *root; /* The root of the sequential tree */
+    ErtsThrPrgrLaterOp free_item; /* Used when freeing using thread progress */
+    struct DbTableCATreeNode * next; /* Used when gradually deleting */
+
+    char end_of_struct__;
+} DbTableCATreeBaseNode;
+
+typedef struct {
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    Sint lc_order;
+#endif
+    ErtsThrPrgrLaterOp free_item; /* Used when freeing using thread progress */
+    erts_mtx_t lock; /* Used when joining route nodes */
+    int is_valid; /* If this route node is still valid */
+    erts_atomic_t left;
+    erts_atomic_t right;
+    DbRouteKey key;
+} DbTableCATreeRouteNode;
+
+typedef struct DbTableCATreeNode {
+    int is_base_node;
+    union {
+        DbTableCATreeRouteNode route;
+        DbTableCATreeBaseNode base;
+    } u;
+} DbTableCATreeNode;
+
+typedef struct {
+    Uint pos;          /* Current position on stack */
+    Uint size;         /* The size of the stack array */
+    DbTableCATreeNode** array; /* The stack */
+} CATreeNodeStack;
+
+typedef struct db_table_catree {
+    DbTableCommon common;
+
+    /* CA Tree-specific fields */
+    erts_atomic_t root;         /* The tree root (DbTableCATreeNode*) */
+    Uint deletion;		/* Being deleted */
+    DbTreeStack free_stack_elems;/* Used for deletion ...*/
+    CATreeNodeStack free_stack_rnodes;
+    DbTableCATreeNode *base_nodes_to_free_list;
+    int is_routing_nodes_freed;
+    /* The fields below are used by delete_all_objects and
+       select_delete(DeleteAll)*/
+    Uint nr_of_deleted_items;
+    Binary* nr_of_deleted_items_wb;
+} DbTableCATree;
+
+typedef struct {
+    DbTableCATree* tb;
+    Eterm next_route_key;
+    DbTableCATreeNode* locked_bnode;
+    DbTableCATreeNode* bnode_parent;
+    int bnode_level;
+    int read_only;
+    DbRouteKey* search_key;
+} CATreeRootIterator;
+
+
+void db_initialize_catree(void);
+
+int db_create_catree(Process *p, DbTable *tbl);
+
+TreeDbTerm** catree_find_root(Eterm key, CATreeRootIterator*);
+
+TreeDbTerm** catree_find_next_from_pb_key_root(Eterm key, CATreeRootIterator*);
+TreeDbTerm** catree_find_prev_from_pb_key_root(Eterm key, CATreeRootIterator*);
+TreeDbTerm** catree_find_nextprev_root(CATreeRootIterator*, int next, Eterm* keyp);
+TreeDbTerm** catree_find_next_root(CATreeRootIterator*, Eterm* keyp);
+TreeDbTerm** catree_find_prev_root(CATreeRootIterator*, Eterm* keyp);
+TreeDbTerm** catree_find_first_root(CATreeRootIterator*);
+TreeDbTerm** catree_find_last_root(CATreeRootIterator*);
+
+
+#ifdef ERTS_ENABLE_LOCK_COUNT
+void erts_lcnt_enable_db_catree_lock_count(DbTableCATree *tb, int enable);
+#endif
+
+void db_catree_force_split(DbTableCATree*, int on);
+void db_catree_debug_random_split_join(DbTableCATree*, int on);
+
+typedef struct {
+    Uint route_nodes;
+    Uint base_nodes;
+    Uint max_depth;
+} DbCATreeStats;
+void db_calc_stats_catree(DbTableCATree*, DbCATreeStats*);
+void
+erts_db_foreach_thr_prgr_offheap_catree(void (*func)(ErlOffHeap *, void *),
+                                        void *arg);
+
+
+#endif /* _DB_CATREE_H */
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index 752d3ae3a8..4904d3fa42 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -85,6 +85,14 @@
 
 #include "erl_db_hash.h"
 
+#define ADD_NITEMS(DB, TO_ADD)                                          \
+    erts_flxctr_add(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID, TO_ADD)
+#define INC_NITEMS(DB)                                                  \
+    erts_flxctr_inc_read_centralized(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID)
+#define DEC_NITEMS(DB)                                                  \
+    erts_flxctr_dec_read_centralized(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID)
+#define RESET_NITEMS(DB)                                                \
+    erts_flxctr_reset(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID)
 /* 
  * The following symbols can be manipulated to "tune" the linear hash array 
  */
@@ -121,7 +129,9 @@
      : ((struct segment**) erts_atomic_read_nob(&(tb)->segtab)))
 #endif
 #define NACTIVE(tb) ((int)erts_atomic_read_nob(&(tb)->nactive))
-#define NITEMS(tb) ((int)erts_atomic_read_nob(&(tb)->common.nitems))
+#define NITEMS(tb) \
+    ((Sint)erts_flxctr_read_centralized(&(tb)->common.counters,             \
+                                        ERTS_DB_TABLE_NITEMS_COUNTER_ID))
 
 #define SLOT_IX_TO_SEG_IX(i) (((i)+(EXT_SEGSZ-FIRST_SEGSZ)) >> EXT_SEGSZ_EXP)
 
@@ -404,26 +414,31 @@ static int db_slot_hash(Process *p, DbTable *tbl,
 
 static int db_select_chunk_hash(Process *p, DbTable *tbl, Eterm tid,
 				Eterm pattern, Sint chunk_size,
-				int reverse, Eterm *ret);
+				int reverse, Eterm *ret, enum DbIterSafety);
 static int db_select_hash(Process *p, DbTable *tbl, Eterm tid,
-			  Eterm pattern, int reverse, Eterm *ret);
+			  Eterm pattern, int reverse, Eterm *ret,
+                          enum DbIterSafety);
 static int db_select_continue_hash(Process *p, DbTable *tbl,
-				   Eterm continuation, Eterm *ret);
+				   Eterm continuation, Eterm *ret,
+                                   enum DbIterSafety*);
 
 static int db_select_count_hash(Process *p, DbTable *tbl, Eterm tid,
-				Eterm pattern, Eterm *ret);
+				Eterm pattern, Eterm *ret, enum DbIterSafety);
 static int db_select_count_continue_hash(Process *p, DbTable *tbl,
-					 Eterm continuation, Eterm *ret);
-
+					 Eterm continuation, Eterm *ret,
+                                         enum DbIterSafety*);
 static int db_select_delete_hash(Process *p, DbTable *tbl, Eterm tid,
-				 Eterm pattern, Eterm *ret);
+				 Eterm pattern, Eterm *ret,
+                                 enum DbIterSafety);
 static int db_select_delete_continue_hash(Process *p, DbTable *tbl,
-					  Eterm continuation, Eterm *ret);
+					  Eterm continuation, Eterm *ret,
+                                          enum DbIterSafety*);
 
 static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid,
-                                  Eterm pattern, Eterm *ret);
+                                  Eterm pattern, Eterm *ret, enum DbIterSafety);
 static int db_select_replace_continue_hash(Process *p, DbTable *tbl,
-                                           Eterm continuation, Eterm *ret);
+                                           Eterm continuation, Eterm *ret,
+                                           enum DbIterSafety*);
 
 static int db_take_hash(Process *, DbTable *, Eterm, Eterm *);
 static void db_print_hash(fmtfn_t to,
@@ -439,7 +454,12 @@ static void db_foreach_offheap_hash(DbTable *,
 				    void (*)(ErlOffHeap *, void *),
 				    void *);
 
-static SWord db_delete_all_objects_hash(Process* p, DbTable* tbl, SWord reds);
+static SWord db_delete_all_objects_hash(Process* p,
+                                        DbTable* tbl,
+                                        SWord reds,
+                                        Eterm* nitems_holder_wb);
+static Eterm db_delete_all_objects_get_nitems_from_holder_hash(Process* p,
+                                                               Eterm nitems_holder);
 #ifdef HARDDEBUG
 static void db_check_table_hash(DbTableHash *tb);
 #endif
@@ -535,7 +555,7 @@ DbTableMethod db_hash =
     db_select_chunk_hash,
     db_select_hash,
     db_select_delete_hash,
-    db_select_continue_hash, /* hmm continue_hash? */
+    db_select_continue_hash,
     db_select_delete_continue_hash,
     db_select_count_hash,
     db_select_count_continue_hash,
@@ -543,6 +563,7 @@ DbTableMethod db_hash =
     db_select_replace_continue_hash,
     db_take_hash,
     db_delete_all_objects_hash,
+    db_delete_all_objects_get_nitems_from_holder_hash,
     db_free_empty_table_hash,
     db_free_table_continue_hash,
     db_print_hash,
@@ -801,7 +822,7 @@ int db_put_hash(DbTable *tbl, Eterm obj, int key_clash_fail)
     if (tb->common.status & DB_SET) {
 	HashDbTerm* bnext = b->next;
 	if (is_pseudo_deleted(b)) {
-	    erts_atomic_inc_nob(&tb->common.nitems);
+            INC_NITEMS(tb);
             b->pseudo_deleted = 0;
 	}
 	else if (key_clash_fail) {
@@ -830,7 +851,7 @@ int db_put_hash(DbTable *tbl, Eterm obj, int key_clash_fail)
 	do {
 	    if (db_eq(&tb->common,obj,&q->dbterm)) {
 		if (is_pseudo_deleted(q)) {
-		    erts_atomic_inc_nob(&tb->common.nitems);
+		    INC_NITEMS(tb);
                     q->pseudo_deleted = 0;
 		    ASSERT(q->hvalue == hval);
 		    if (q != b) { /* must move to preserve key insertion order */
@@ -853,7 +874,7 @@ Lnew:
     q->pseudo_deleted = 0;
     q->next = b;
     *bp = q;
-    nitems = erts_atomic_inc_read_nob(&tb->common.nitems);
+    nitems = INC_NITEMS(tb);
     WUNLOCK_HASH(lck);
     {
 	int nactive = NACTIVE(tb);       
@@ -1051,7 +1072,7 @@ int db_erase_hash(DbTable *tbl, Eterm key, Eterm *ret)
     }
     WUNLOCK_HASH(lck);
     if (nitems_diff) {
-	erts_atomic_add_nob(&tb->common.nitems, nitems_diff);
+        ADD_NITEMS(tb, nitems_diff);
 	try_shrink(tb);
     }
     free_term_list(tb, free_us);
@@ -1112,7 +1133,7 @@ static int db_erase_object_hash(DbTable *tbl, Eterm object, Eterm *ret)
     }
     WUNLOCK_HASH(lck);
     if (nitems_diff) {
-	erts_atomic_add_nob(&tb->common.nitems, nitems_diff);
+        ADD_NITEMS(tb, nitems_diff);
 	try_shrink(tb);
     }
     free_term_list(tb, free_us);
@@ -1154,8 +1175,9 @@ static int db_slot_hash(Process *p, DbTable *tbl, Eterm slot_term, Eterm *ret)
  * Match traversal callbacks
  */
 
-typedef struct match_callbacks_t_ match_callbacks_t;
-struct match_callbacks_t_
+
+typedef struct traverse_context_t_ traverse_context_t;
+struct traverse_context_t_
 {
 /* Called when no match is possible.
  *      context_ptr: Pointer to context
@@ -1163,7 +1185,7 @@ struct match_callbacks_t_
  *
  * Both the direct return value and 'ret' are used as the traversal function return values.
  */
-    int (*on_nothing_can_match)(match_callbacks_t* ctx, Eterm* ret);
+    int (*on_nothing_can_match)(traverse_context_t* ctx, Eterm* ret);
 
 /* Called for each match result.
  *      context_ptr: Pointer to context
@@ -1174,7 +1196,7 @@ struct match_callbacks_t_
  *
  * Should return 1 for successful match, 0 otherwise.
  */
-    int (*on_match_res)(match_callbacks_t* ctx, Sint slot_ix,
+    int (*on_match_res)(traverse_context_t* ctx, Sint slot_ix,
                         HashDbTerm*** current_ptr_ptr, Eterm match_res);
 
 /* Called when either we've matched enough elements in this cycle or EOT was reached.
@@ -1188,7 +1210,7 @@ struct match_callbacks_t_
  * Both the direct return value and 'ret' are used as the traversal function return values.
  * If *mpp is set to NULL, it won't be deallocated (useful for trapping.)
  */
-    int (*on_loop_ended)(match_callbacks_t* ctx, Sint slot_ix, Sint got,
+    int (*on_loop_ended)(traverse_context_t* ctx, Sint slot_ix, Sint got,
                          Sint iterations_left, Binary** mpp, Eterm* ret);
 
 /* Called when it's time to trap
@@ -1201,16 +1223,21 @@ struct match_callbacks_t_
  * Both the direct return value and 'ret' are used as the traversal function return values.
  * If *mpp is set to NULL, it won't be deallocated (useful for trapping.)
  */
-    int (*on_trap)(match_callbacks_t* ctx, Sint slot_ix, Sint got, Binary** mpp,
+    int (*on_trap)(traverse_context_t* ctx, Sint slot_ix, Sint got, Binary** mpp,
                    Eterm* ret);
 
+    Process* p;
+    DbTableHash* tb;
+    Eterm tid;
+    Eterm* prev_continuation_tptr;
+    enum DbIterSafety safety;
 };
 
 
 /*
  * Begin hash table match traversal
  */
-static int match_traverse(Process* p, DbTableHash* tb,
+static int match_traverse(traverse_context_t* ctx,
                           Eterm pattern,
                           extra_match_validator_t extra_match_validator, /* Optional */
                           Sint chunk_size,      /* If 0, no chunking */
@@ -1218,9 +1245,9 @@ static int match_traverse(Process* p, DbTableHash* tb,
                           Eterm** hpp,          /* Heap */
                           int lock_for_write,   /* Set to 1 if we're going to delete or
                                                    modify existing terms */
-                          match_callbacks_t* ctx,
                           Eterm* ret)
 {
+    DbTableHash* tb = ctx->tb;
     Sint slot_ix;                  /* Slot index */
     HashDbTerm** current_ptr;      /* Refers to either the bucket pointer or
                                     * the 'next' pointer in the previous term
@@ -1287,7 +1314,7 @@ static int match_traverse(Process* p, DbTableHash* tb,
     for(;;) {
         if (*current_ptr != NULL) {
             if (!is_pseudo_deleted(*current_ptr)) {
-                match_res = db_match_dbterm(&tb->common, p, mpi.mp,
+                match_res = db_match_dbterm(&tb->common, ctx->p, mpi.mp,
                                             &(*current_ptr)->dbterm, hpp, 2);
                 saved_current = *current_ptr;
                 if (ctx->on_match_res(ctx, slot_ix, &current_ptr, match_res)) {
@@ -1323,11 +1350,7 @@ static int match_traverse(Process* p, DbTableHash* tb,
                 unlock_hash_function(lck);
                 break;
             }
-            if (iterations_left <= 0 || MBUF(p)) {
-                /*
-                 * We have either reached our limit, or just created some heap fragments.
-                 * Since many heap fragments will make the GC slower, trap and GC now.
-                 */
+            if (iterations_left <= 0) {
                 unlock_hash_function(lck);
                 ret_value = ctx->on_trap(ctx, slot_ix, got, &mpi.mp, ret);
                 goto done;
@@ -1356,7 +1379,7 @@ done:
 /*
  * Continue hash table match traversal
  */
-static int match_traverse_continue(Process* p, DbTableHash* tb,
+static int match_traverse_continue(traverse_context_t* ctx,
                                    Sint chunk_size,      /* If 0, no chunking */
                                    Sint iterations_left, /* Nr. of iterations left */
                                    Eterm** hpp,          /* Heap */
@@ -1365,9 +1388,9 @@ static int match_traverse_continue(Process* p, DbTableHash* tb,
                                    Binary** mpp,         /* Existing match program */
                                    int lock_for_write,   /* Set to 1 if we're going to delete or
                                                             modify existing terms */
-                                   match_callbacks_t* ctx,
                                    Eterm* ret)
 {
+    DbTableHash* tb = ctx->tb;
     HashDbTerm** current_ptr;  /* Refers to either the bucket pointer or
                                        * the 'next' pointer in the previous term
                                        */
@@ -1410,7 +1433,7 @@ static int match_traverse_continue(Process* p, DbTableHash* tb,
     for(;;) {
         if (*current_ptr != NULL) {
             if (!is_pseudo_deleted(*current_ptr)) {
-                match_res = db_match_dbterm(&tb->common, p, *mpp,
+                match_res = db_match_dbterm(&tb->common, ctx->p, *mpp,
                                             &(*current_ptr)->dbterm, hpp, 2);
                 saved_current = *current_ptr;
                 if (ctx->on_match_res(ctx, slot_ix, &current_ptr, match_res)) {
@@ -1433,11 +1456,7 @@ static int match_traverse_continue(Process* p, DbTableHash* tb,
                 unlock_hash_function(lck);
                 break;
             }
-            if (iterations_left <= 0 || MBUF(p)) {
-                /*
-                 * We have either reached our limit, or just created some heap fragments.
-                 * Since many heap fragments will make the GC slower, trap and GC now.
-                 */
+            if (iterations_left <= 0) {
                 unlock_hash_function(lck);
                 ret_value = ctx->on_trap(ctx, slot_ix, got, mpp, ret);
                 goto done;
@@ -1464,52 +1483,50 @@ done:
  */
 
 static ERTS_INLINE int on_simple_trap(Export* trap_function,
-                                                 Process* p,
-                                                 DbTableHash* tb,
-                                                 Eterm tid,
-                                                 Eterm* prev_continuation_tptr,
-                                                 Sint slot_ix,
-                                                 Sint got,
-                                                 Binary** mpp,
-                                                 Eterm* ret)
+                                      traverse_context_t* ctx,
+                                      Sint slot_ix,
+                                      Sint got,
+                                      Binary** mpp,
+                                      Eterm* ret)
 {
     Eterm* hp;
     Eterm egot;
     Eterm mpb;
     Eterm continuation;
-    int is_first_trap = (prev_continuation_tptr == NULL);
+    int is_first_trap = (ctx->prev_continuation_tptr == NULL);
     size_t base_halloc_sz = (is_first_trap ? ERTS_MAGIC_REF_THING_SIZE : 0);
 
-    BUMP_ALL_REDS(p);
+    BUMP_ALL_REDS(ctx->p);
     if (IS_USMALL(0, got)) {
-	hp = HAllocX(p,  base_halloc_sz + 5, ERTS_MAGIC_REF_THING_SIZE);
+	hp = HAllocX(ctx->p,  base_halloc_sz + 6, ERTS_MAGIC_REF_THING_SIZE);
 	egot = make_small(got);
     }
     else {
-	hp = HAllocX(p, base_halloc_sz + BIG_UINT_HEAP_SIZE + 5,
+	hp = HAllocX(ctx->p, base_halloc_sz + BIG_UINT_HEAP_SIZE + 6,
                      ERTS_MAGIC_REF_THING_SIZE);
 	egot = uint_to_big(got, hp);
 	hp += BIG_UINT_HEAP_SIZE;
     }
 
     if (is_first_trap) {
-        if (is_atom(tid))
-            tid = erts_db_make_tid(p, &tb->common);
-        mpb = erts_db_make_match_prog_ref(p, *mpp, &hp);
+        if (is_atom(ctx->tid))
+            ctx->tid = erts_db_make_tid(ctx->p, &ctx->tb->common);
+        mpb = erts_db_make_match_prog_ref(ctx->p, *mpp, &hp);
         *mpp = NULL; /* otherwise the caller will destroy it */
     }
     else {
-        ASSERT(!is_atom(tid));
-        mpb = prev_continuation_tptr[3];
+        ASSERT(!is_atom(ctx->tid));
+        mpb = ctx->prev_continuation_tptr[3];
     }
 
-    continuation = TUPLE4(
+    continuation = TUPLE5(
             hp,
-            tid,
+            ctx->tid,
             make_small(slot_ix),
             mpb,
-            egot);
-    ERTS_BIF_PREP_TRAP1(*ret, trap_function, p, continuation);
+            egot,
+            make_small(ctx->safety));
+    ERTS_BIF_PREP_TRAP1(*ret, trap_function, ctx->p, continuation);
     return DB_ERROR_NONE;
 }
 
@@ -1518,17 +1535,18 @@ static ERTS_INLINE int unpack_simple_continuation(Eterm continuation,
                                                   Eterm* tid_ptr,
                                                   Sint* slot_ix_p,
                                                   Binary** mpp,
-                                                  Sint* got_p)
+                                                  Sint* got_p,
+                                                  enum DbIterSafety* safety_p)
 {
     Eterm* tptr;
     ASSERT(is_tuple(continuation));
     tptr = tuple_val(continuation);
-    if (arityval(*tptr) != 4)
+    if (*tptr != make_arityval(5))
         return 1;
 
-    if (! is_small(tptr[2]) || !(is_big(tptr[4]) || is_small(tptr[4]))) {
+    if (!is_small(tptr[2]) || !(is_big(tptr[4]) || is_small(tptr[4]))
+        || !is_small(tptr[5]))
         return 1;
-    }
 
     *tptr_ptr = tptr;
     *tid_ptr = tptr[1];
@@ -1540,6 +1558,7 @@ static ERTS_INLINE int unpack_simple_continuation(Eterm continuation,
     else {
         *got_p = unsigned_val(tptr[4]);
     }
+    *safety_p = signed_val(tptr[5]);
     return 0;
 }
 
@@ -1553,24 +1572,20 @@ static ERTS_INLINE int unpack_simple_continuation(Eterm continuation,
 #define MAX_SELECT_CHUNK_ITERATIONS 1000
 
 typedef struct {
-    match_callbacks_t base;
-    Process* p;
-    DbTableHash* tb;
-    Eterm tid;
+    traverse_context_t base;
     Eterm* hp;
     Sint chunk_size;
     Eterm match_list;
-    Eterm* prev_continuation_tptr;
 } select_chunk_context_t;
 
-static int select_chunk_on_nothing_can_match(match_callbacks_t* ctx_base, Eterm* ret)
+static int select_chunk_on_nothing_can_match(traverse_context_t* ctx_base, Eterm* ret)
 {
     select_chunk_context_t* ctx = (select_chunk_context_t*) ctx_base;
     *ret = (ctx->chunk_size > 0 ? am_EOT : NIL);
     return DB_ERROR_NONE;
 }
 
-static int select_chunk_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
+static int select_chunk_on_match_res(traverse_context_t* ctx_base, Sint slot_ix,
                                      HashDbTerm*** current_ptr_ptr,
                                      Eterm match_res)
 {
@@ -1582,7 +1597,7 @@ static int select_chunk_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
     return 0;
 }
 
-static int select_chunk_on_loop_ended(match_callbacks_t* ctx_base,
+static int select_chunk_on_loop_ended(traverse_context_t* ctx_base,
                                       Sint slot_ix, Sint got,
                                       Sint iterations_left, Binary** mpp,
                                       Eterm* ret)
@@ -1598,7 +1613,7 @@ static int select_chunk_on_loop_ended(match_callbacks_t* ctx_base,
     }
     else {
         ASSERT(iterations_left < MAX_SELECT_CHUNK_ITERATIONS);
-        BUMP_REDS(ctx->p, MAX_SELECT_CHUNK_ITERATIONS - iterations_left);
+        BUMP_REDS(ctx->base.p, MAX_SELECT_CHUNK_ITERATIONS - iterations_left);
         if (ctx->chunk_size) {
             Eterm continuation;
             Eterm rest = NIL;
@@ -1617,14 +1632,14 @@ static int select_chunk_on_loop_ended(match_callbacks_t* ctx_base,
                                              been in 'user space' */
             }
             if (rest != NIL || slot_ix >= 0) { /* Need more calls */
-                Eterm tid = ctx->tid;
-                ctx->hp = HAllocX(ctx->p,
+                Eterm tid = ctx->base.tid;
+                ctx->hp = HAllocX(ctx->base.p,
                                   3 + 7 + ERTS_MAGIC_REF_THING_SIZE,
                                   ERTS_MAGIC_REF_THING_SIZE);
-                mpb = erts_db_make_match_prog_ref(ctx->p, *mpp, &ctx->hp);
+                mpb = erts_db_make_match_prog_ref(ctx->base.p, *mpp, &ctx->hp);
                 if (is_atom(tid))
-                    tid = erts_db_make_tid(ctx->p,
-                                           &ctx->tb->common);
+                    tid = erts_db_make_tid(ctx->base.p,
+                                           &ctx->base.tb->common);
                 continuation = TUPLE6(
                         ctx->hp,
                         tid,
@@ -1639,7 +1654,7 @@ static int select_chunk_on_loop_ended(match_callbacks_t* ctx_base,
             } else { /* All data is exhausted */
                 if (ctx->match_list != NIL) { /* No more data to search but still a
                                                             result to return to the caller */
-                    ctx->hp = HAlloc(ctx->p, 3);
+                    ctx->hp = HAlloc(ctx->base.p, 3);
                     *ret = TUPLE2(ctx->hp, ctx->match_list, am_EOT);
                     return DB_ERROR_NONE;
                 } else { /* Reached the end of the ttable with no data to return */
@@ -1653,7 +1668,7 @@ static int select_chunk_on_loop_ended(match_callbacks_t* ctx_base,
     }
 }
 
-static int select_chunk_on_trap(match_callbacks_t* ctx_base,
+static int select_chunk_on_trap(traverse_context_t* ctx_base,
                                 Sint slot_ix, Sint got,
                                 Binary** mpp, Eterm* ret)
 {
@@ -1662,74 +1677,77 @@ static int select_chunk_on_trap(match_callbacks_t* ctx_base,
     Eterm continuation;
     Eterm* hp;
 
-    BUMP_ALL_REDS(ctx->p);
+    BUMP_ALL_REDS(ctx->base.p);
 
-    if (ctx->prev_continuation_tptr == NULL) {
-        Eterm tid = ctx->tid;
+    if (ctx->base.prev_continuation_tptr == NULL) {
+        Eterm tid = ctx->base.tid;
         /* First time we're trapping */
-        hp = HAllocX(ctx->p, 7 + ERTS_MAGIC_REF_THING_SIZE,
+        hp = HAllocX(ctx->base.p, 8 + ERTS_MAGIC_REF_THING_SIZE,
                      ERTS_MAGIC_REF_THING_SIZE);
         if (is_atom(tid))
-            tid = erts_db_make_tid(ctx->p, &ctx->tb->common);
-        mpb = erts_db_make_match_prog_ref(ctx->p, *mpp, &hp);
-        continuation = TUPLE6(
+            tid = erts_db_make_tid(ctx->base.p, &ctx->base.tb->common);
+        mpb = erts_db_make_match_prog_ref(ctx->base.p, *mpp, &hp);
+        continuation = TUPLE7(
                 hp,
                 tid,
                 make_small(slot_ix),
                 make_small(ctx->chunk_size),
                 mpb,
                 ctx->match_list,
-                make_small(got));
+                make_small(got),
+                make_small(ctx->base.safety));
         *mpp = NULL; /* otherwise the caller will destroy it */
     }
     else {
         /* Not the first time we're trapping; reuse continuation terms */
-        hp = HAlloc(ctx->p, 7);
-        continuation = TUPLE6(
+        hp = HAlloc(ctx->base.p, 8);
+        continuation = TUPLE7(
                 hp,
-                ctx->prev_continuation_tptr[1],
+                ctx->base.prev_continuation_tptr[1],
                 make_small(slot_ix),
-                ctx->prev_continuation_tptr[3],
-                ctx->prev_continuation_tptr[4],
+                ctx->base.prev_continuation_tptr[3],
+                ctx->base.prev_continuation_tptr[4],
                 ctx->match_list,
-                make_small(got));
+                make_small(got),
+                make_small(ctx->base.safety));
     }
-    ERTS_BIF_PREP_TRAP1(*ret, &ets_select_continue_exp, ctx->p,
+    ERTS_BIF_PREP_TRAP1(*ret, &ets_select_continue_exp, ctx->base.p,
                         continuation);
     return DB_ERROR_NONE;
 }
 
 static int db_select_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern,
-                          int reverse, Eterm *ret)
+                          int reverse, Eterm *ret, enum DbIterSafety safety)
 {
-    return db_select_chunk_hash(p, tbl, tid, pattern, 0, reverse, ret);
+    return db_select_chunk_hash(p, tbl, tid, pattern, 0, reverse, ret, safety);
 }
 
 static int db_select_chunk_hash(Process *p, DbTable *tbl, Eterm tid,
                                 Eterm pattern, Sint chunk_size,
-                                int reverse, Eterm *ret)
+                                int reverse, Eterm *ret, enum DbIterSafety safety)
 {
     select_chunk_context_t ctx;
 
     ctx.base.on_nothing_can_match = select_chunk_on_nothing_can_match;
     ctx.base.on_match_res         = select_chunk_on_match_res;
     ctx.base.on_loop_ended        = select_chunk_on_loop_ended;
-    ctx.base.on_trap              = select_chunk_on_trap,
-    ctx.p = p;
-    ctx.tb = &tbl->hash;
-    ctx.tid = tid;
+    ctx.base.on_trap              = select_chunk_on_trap;
+    ctx.base.p = p;
+    ctx.base.tb = &tbl->hash;
+    ctx.base.tid = tid;
+    ctx.base.prev_continuation_tptr = NULL;
+    ctx.base.safety = safety;
     ctx.hp = NULL;
     ctx.chunk_size = chunk_size;
     ctx.match_list = NIL;
-    ctx.prev_continuation_tptr = NULL;
 
     return match_traverse(
-            ctx.p, ctx.tb,
+            &ctx.base,
             pattern, NULL,
             ctx.chunk_size,
             MAX_SELECT_CHUNK_ITERATIONS,
             &ctx.hp, 0,
-            &ctx.base, ret);
+            ret);
 }
 
 /*
@@ -1739,7 +1757,7 @@ static int db_select_chunk_hash(Process *p, DbTable *tbl, Eterm tid,
  */
 
 static
-int select_chunk_continue_on_loop_ended(match_callbacks_t* ctx_base,
+int select_chunk_continue_on_loop_ended(traverse_context_t* ctx_base,
                                         Sint slot_ix, Sint got,
                                         Sint iterations_left, Binary** mpp,
                                         Eterm* ret)
@@ -1750,14 +1768,14 @@ int select_chunk_continue_on_loop_ended(match_callbacks_t* ctx_base,
     Eterm* hp;
 
     ASSERT(iterations_left <= MAX_SELECT_CHUNK_ITERATIONS);
-    BUMP_REDS(ctx->p, MAX_SELECT_CHUNK_ITERATIONS - iterations_left);
+    BUMP_REDS(ctx->base.p, MAX_SELECT_CHUNK_ITERATIONS - iterations_left);
     if (ctx->chunk_size) {
         Sint rest_size = 0;
         if (got > ctx->chunk_size) {
             /* Cannot write destructively here,
                the list may have
                been in user space */
-            hp = HAlloc(ctx->p, (got - ctx->chunk_size) * 2);
+            hp = HAlloc(ctx->base.p, (got - ctx->chunk_size) * 2);
             while (got-- > ctx->chunk_size) {
                 rest = CONS(hp, CAR(list_val(ctx->match_list)), rest);
                 hp += 2;
@@ -1766,13 +1784,13 @@ int select_chunk_continue_on_loop_ended(match_callbacks_t* ctx_base,
             }
         }
         if (rest != NIL || slot_ix >= 0) {
-            hp = HAlloc(ctx->p, 3 + 7);
+            hp = HAlloc(ctx->base.p, 3 + 7);
             continuation = TUPLE6(
                     hp,
-                    ctx->prev_continuation_tptr[1],
+                    ctx->base.prev_continuation_tptr[1],
                     make_small(slot_ix),
-                    ctx->prev_continuation_tptr[3],
-                    ctx->prev_continuation_tptr[4],
+                    ctx->base.prev_continuation_tptr[3],
+                    ctx->base.prev_continuation_tptr[4],
                     rest,
                     make_small(rest_size));
             hp += 7;
@@ -1780,7 +1798,7 @@ int select_chunk_continue_on_loop_ended(match_callbacks_t* ctx_base,
             return DB_ERROR_NONE;
         } else {
             if (ctx->match_list != NIL) {
-                hp = HAlloc(ctx->p, 3);
+                hp = HAlloc(ctx->base.p, 3);
                 *ret = TUPLE2(hp, ctx->match_list, am_EOT);
                 return DB_ERROR_NONE;
             } else {
@@ -1794,10 +1812,11 @@ int select_chunk_continue_on_loop_ended(match_callbacks_t* ctx_base,
 }
 
 /*
- * This is called when select traps
+ * This is called when ets:select/1/2/3 traps
+ * and for ets:select/1 with user continuation term.
  */
 static int db_select_continue_hash(Process* p, DbTable* tbl, Eterm continuation,
-                                   Eterm* ret)
+                                   Eterm* ret, enum DbIterSafety* safety_p)
 {
     select_chunk_context_t ctx;
     Eterm* tptr;
@@ -1813,7 +1832,13 @@ static int db_select_continue_hash(Process* p, DbTable* tbl, Eterm continuation,
     ASSERT(is_tuple(continuation));
     tptr = tuple_val(continuation);
 
-    if (arityval(*tptr) != 6)
+    /*
+     * 6-tuple is select/1 user continuation term
+     * 7-tuple is select trap continuation
+     */
+    if (*tptr == make_arityval(7) && is_small(tptr[7]))
+        *safety_p = signed_val(tptr[7]);
+    else if (*tptr != make_arityval(6))
         goto badparam;
 
     if (!is_small(tptr[2]) || !is_small(tptr[3]) ||
@@ -1837,18 +1862,19 @@ static int db_select_continue_hash(Process* p, DbTable* tbl, Eterm continuation,
     ctx.base.on_match_res  = select_chunk_on_match_res;
     ctx.base.on_loop_ended = select_chunk_continue_on_loop_ended;
     ctx.base.on_trap       = select_chunk_on_trap;
-    ctx.p = p;
-    ctx.tb = &tbl->hash;
-    ctx.tid = tid;
+    ctx.base.p = p;
+    ctx.base.tb = &tbl->hash;
+    ctx.base.tid = tid;
+    ctx.base.prev_continuation_tptr = tptr;
+    ctx.base.safety = *safety_p;
     ctx.hp = NULL;
     ctx.chunk_size = chunk_size;
     ctx.match_list = match_list;
-    ctx.prev_continuation_tptr = tptr;
 
     return match_traverse_continue(
-            ctx.p, ctx.tb, ctx.chunk_size,
-            iterations_left, &ctx.hp, slot_ix, got, &mp, 0,
-            &ctx.base, ret);
+        &ctx.base, ctx.chunk_size,
+        iterations_left, &ctx.hp, slot_ix, got, &mp, 0,
+        ret);
 
 badparam:
     *ret = NIL;
@@ -1866,84 +1892,73 @@ badparam:
 
 #define MAX_SELECT_COUNT_ITERATIONS 1000
 
-typedef struct {
-    match_callbacks_t base;
-    Process* p;
-    DbTableHash* tb;
-    Eterm tid;
-    Eterm* prev_continuation_tptr;
-} select_count_context_t;
-
-static int select_count_on_nothing_can_match(match_callbacks_t* ctx_base,
+static int select_count_on_nothing_can_match(traverse_context_t* ctx_base,
                                              Eterm* ret)
 {
     *ret = make_small(0);
     return DB_ERROR_NONE;
 }
 
-static int select_count_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
+static int select_count_on_match_res(traverse_context_t* ctx_base, Sint slot_ix,
                                      HashDbTerm*** current_ptr_ptr,
                                      Eterm match_res)
 {
     return (match_res == am_true);
 }
 
-static int select_count_on_loop_ended(match_callbacks_t* ctx_base,
+static int select_count_on_loop_ended(traverse_context_t* ctx,
                                       Sint slot_ix, Sint got,
                                       Sint iterations_left, Binary** mpp,
                                       Eterm* ret)
 {
-    select_count_context_t* ctx = (select_count_context_t*) ctx_base;
     ASSERT(iterations_left <= MAX_SELECT_COUNT_ITERATIONS);
     BUMP_REDS(ctx->p, MAX_SELECT_COUNT_ITERATIONS - iterations_left);
     *ret = erts_make_integer(got, ctx->p);
     return DB_ERROR_NONE;
 }
 
-static int select_count_on_trap(match_callbacks_t* ctx_base,
+static int select_count_on_trap(traverse_context_t* ctx,
                                 Sint slot_ix, Sint got,
                                 Binary** mpp, Eterm* ret)
 {
-    select_count_context_t* ctx = (select_count_context_t*) ctx_base;
     return on_simple_trap(
-            &ets_select_count_continue_exp,
-            ctx->p,
-            ctx->tb,
-            ctx->tid,
-            ctx->prev_continuation_tptr,
+            &ets_select_count_continue_exp, ctx,
             slot_ix, got, mpp, ret);
 }
 
 static int db_select_count_hash(Process *p, DbTable *tbl, Eterm tid,
-                                Eterm pattern, Eterm *ret)
+                                Eterm pattern, Eterm *ret,
+                                enum DbIterSafety safety)
 {
-    select_count_context_t ctx;
+    traverse_context_t ctx;
     Sint iterations_left = MAX_SELECT_COUNT_ITERATIONS;
     Sint chunk_size = 0;
 
-    ctx.base.on_nothing_can_match = select_count_on_nothing_can_match;
-    ctx.base.on_match_res         = select_count_on_match_res;
-    ctx.base.on_loop_ended        = select_count_on_loop_ended;
-    ctx.base.on_trap              = select_count_on_trap;
+    ctx.on_nothing_can_match = select_count_on_nothing_can_match;
+    ctx.on_match_res         = select_count_on_match_res;
+    ctx.on_loop_ended        = select_count_on_loop_ended;
+    ctx.on_trap              = select_count_on_trap;
     ctx.p = p;
     ctx.tb = &tbl->hash;
     ctx.tid = tid;
     ctx.prev_continuation_tptr = NULL;
+    ctx.safety = safety;
 
     return match_traverse(
-            ctx.p, ctx.tb,
+            &ctx,
             pattern, NULL,
             chunk_size, iterations_left, NULL, 0,
-            &ctx.base, ret);
+            ret);
 }
 
 /*
  * This is called when select_count traps
  */
 static int db_select_count_continue_hash(Process* p, DbTable* tbl,
-                                         Eterm continuation, Eterm* ret)
+                                         Eterm continuation, Eterm* ret,
+                                         enum DbIterSafety* safety_p)
 {
-    select_count_context_t ctx;
+    traverse_context_t ctx;
     Eterm* tptr;
     Eterm tid;
     Binary* mp;
@@ -1952,24 +1967,26 @@ static int db_select_count_continue_hash(Process* p, DbTable* tbl,
     Sint chunk_size = 0;
     *ret = NIL;
 
-    if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
+    if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp,
+                                   &got, safety_p)) {
         *ret = NIL;
         return DB_ERROR_BADPARAM;
     }
 
-    ctx.base.on_match_res  = select_count_on_match_res;
-    ctx.base.on_loop_ended = select_count_on_loop_ended;
-    ctx.base.on_trap       = select_count_on_trap;
+    ctx.on_match_res  = select_count_on_match_res;
+    ctx.on_loop_ended = select_count_on_loop_ended;
+    ctx.on_trap       = select_count_on_trap;
     ctx.p = p;
     ctx.tb = &tbl->hash;
     ctx.tid = tid;
     ctx.prev_continuation_tptr = tptr;
+    ctx.safety = *safety_p;
 
     return match_traverse_continue(
-            ctx.p, ctx.tb, chunk_size,
+            &ctx, chunk_size,
             MAX_SELECT_COUNT_ITERATIONS,
             NULL, slot_ix, got, &mp, 0,
-            &ctx.base, ret);
+            ret);
 }
 
 #undef MAX_SELECT_COUNT_ITERATIONS
@@ -1984,24 +2001,20 @@ static int db_select_count_continue_hash(Process* p, DbTable* tbl,
 #define MAX_SELECT_DELETE_ITERATIONS 1000
 
 typedef struct {
-    match_callbacks_t base;
-    Process* p;
-    DbTableHash* tb;
-    Eterm tid;
-    Eterm* prev_continuation_tptr;
+    traverse_context_t base;
     erts_aint_t fixated_by_me;
     Uint last_pseudo_delete;
     HashDbTerm* free_us;
 } select_delete_context_t;
 
-static int select_delete_on_nothing_can_match(match_callbacks_t* ctx_base,
+static int select_delete_on_nothing_can_match(traverse_context_t* ctx_base,
                                               Eterm* ret)
 {
     *ret = make_small(0);
     return DB_ERROR_NONE;
 }
 
-static int select_delete_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
+static int select_delete_on_match_res(traverse_context_t* ctx_base, Sint slot_ix,
                                       HashDbTerm*** current_ptr_ptr,
                                       Eterm match_res)
 {
@@ -2011,9 +2024,9 @@ static int select_delete_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
     if (match_res != am_true)
         return 0;
 
-    if (NFIXED(ctx->tb) > ctx->fixated_by_me) { /* fixated by others? */
+    if (NFIXED(ctx->base.tb) > ctx->fixated_by_me) { /* fixated by others? */
         if (slot_ix != ctx->last_pseudo_delete) {
-            if (!add_fixed_deletion(ctx->tb, slot_ix, ctx->fixated_by_me))
+            if (!add_fixed_deletion(ctx->base.tb, slot_ix, ctx->fixated_by_me))
                 goto do_erase;
             ctx->last_pseudo_delete = slot_ix;
         }
@@ -2026,46 +2039,43 @@ static int select_delete_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
         del->next = ctx->free_us;
         ctx->free_us = del;
     }
-    erts_atomic_dec_nob(&ctx->tb->common.nitems);
+    DEC_NITEMS(ctx->base.tb);
 
     return 1;
 }
 
-static int select_delete_on_loop_ended(match_callbacks_t* ctx_base,
+static int select_delete_on_loop_ended(traverse_context_t* ctx_base,
                                        Sint slot_ix, Sint got,
                                        Sint iterations_left, Binary** mpp,
                                        Eterm* ret)
 {
     select_delete_context_t* ctx = (select_delete_context_t*) ctx_base;
-    free_term_list(ctx->tb, ctx->free_us);
+    free_term_list(ctx->base.tb, ctx->free_us);
     ctx->free_us = NULL;
     ASSERT(iterations_left <= MAX_SELECT_DELETE_ITERATIONS);
-    BUMP_REDS(ctx->p, MAX_SELECT_DELETE_ITERATIONS - iterations_left);
+    BUMP_REDS(ctx->base.p, MAX_SELECT_DELETE_ITERATIONS - iterations_left);
     if (got) {
-	try_shrink(ctx->tb);
+	try_shrink(ctx->base.tb);
     }
-    *ret = erts_make_integer(got, ctx->p);
+    *ret = erts_make_integer(got, ctx->base.p);
     return DB_ERROR_NONE;
 }
 
-static int select_delete_on_trap(match_callbacks_t* ctx_base,
+static int select_delete_on_trap(traverse_context_t* ctx_base,
                                  Sint slot_ix, Sint got,
                                  Binary** mpp, Eterm* ret)
 {
     select_delete_context_t* ctx = (select_delete_context_t*) ctx_base;
-    free_term_list(ctx->tb, ctx->free_us);
+    free_term_list(ctx->base.tb, ctx->free_us);
     ctx->free_us = NULL;
     return on_simple_trap(
-            &ets_select_delete_continue_exp,
-            ctx->p,
-            ctx->tb,
-            ctx->tid,
-            ctx->prev_continuation_tptr,
+            &ets_select_delete_continue_exp, &ctx->base,
             slot_ix, got, mpp, ret);
 }
 
 static int db_select_delete_hash(Process *p, DbTable *tbl, Eterm tid,
-                                 Eterm pattern, Eterm *ret)
+                                 Eterm pattern, Eterm *ret,
+                                 enum DbIterSafety safety)
 {
     select_delete_context_t ctx;
     Sint chunk_size = 0;
@@ -2074,27 +2084,29 @@ static int db_select_delete_hash(Process *p, DbTable *tbl, Eterm tid,
     ctx.base.on_match_res         = select_delete_on_match_res;
     ctx.base.on_loop_ended        = select_delete_on_loop_ended;
     ctx.base.on_trap              = select_delete_on_trap;
-    ctx.p = p;
-    ctx.tb = &tbl->hash;
-    ctx.tid = tid;
-    ctx.prev_continuation_tptr = NULL;
-    ctx.fixated_by_me = ctx.tb->common.is_thread_safe ? 0 : 1; /* TODO: something nicer */
+    ctx.base.p = p;
+    ctx.base.tb = &tbl->hash;
+    ctx.base.tid = tid;
+    ctx.base.prev_continuation_tptr = NULL;
+    ctx.base.safety = safety;
+    ctx.fixated_by_me = ctx.base.tb->common.is_thread_safe ? 0 : 1;
     ctx.last_pseudo_delete = (Uint) -1;
     ctx.free_us = NULL;
 
     return match_traverse(
-            ctx.p, ctx.tb,
+            &ctx.base,
             pattern, NULL,
             chunk_size,
             MAX_SELECT_DELETE_ITERATIONS, NULL, 1,
-            &ctx.base, ret);
+            ret);
 }
 
 /*
  * This is called when select_delete traps
  */
 static int db_select_delete_continue_hash(Process* p, DbTable* tbl,
-                                          Eterm continuation, Eterm* ret)
+                                          Eterm continuation, Eterm* ret,
+                                          enum DbIterSafety* safety_p)
 {
     select_delete_context_t ctx;
     Eterm* tptr;
@@ -2104,7 +2116,8 @@ static int db_select_delete_continue_hash(Process* p, DbTable* tbl,
     Sint slot_ix;
     Sint chunk_size = 0;
 
-    if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
+    if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp,
+                                   &got, safety_p)) {
         *ret = NIL;
         return DB_ERROR_BADPARAM;
     }
@@ -2112,19 +2125,20 @@ static int db_select_delete_continue_hash(Process* p, DbTable* tbl,
     ctx.base.on_match_res  = select_delete_on_match_res;
     ctx.base.on_loop_ended = select_delete_on_loop_ended;
     ctx.base.on_trap       = select_delete_on_trap;
-    ctx.p = p;
-    ctx.tb = &tbl->hash;
-    ctx.tid = tid;
-    ctx.prev_continuation_tptr = tptr;
-    ctx.fixated_by_me = ONLY_WRITER(p, ctx.tb) ? 0 : 1; /* TODO: something nicer */
+    ctx.base.p = p;
+    ctx.base.tb = &tbl->hash;
+    ctx.base.tid = tid;
+    ctx.base.prev_continuation_tptr = tptr;
+    ctx.base.safety = *safety_p;
+    ctx.fixated_by_me = ONLY_WRITER(p, ctx.base.tb) ? 0 : 1;
     ctx.last_pseudo_delete = (Uint) -1;
     ctx.free_us = NULL;
 
     return match_traverse_continue(
-            ctx.p, ctx.tb, chunk_size,
+            &ctx.base, chunk_size,
             MAX_SELECT_DELETE_ITERATIONS,
             NULL, slot_ix, got, &mp, 1,
-            &ctx.base, ret);
+            ret);
 }
 
 #undef MAX_SELECT_DELETE_ITERATIONS
@@ -2138,26 +2152,17 @@ static int db_select_delete_continue_hash(Process* p, DbTable* tbl,
 
 #define MAX_SELECT_REPLACE_ITERATIONS 1000
 
-typedef struct {
-    match_callbacks_t base;
-    Process* p;
-    DbTableHash* tb;
-    Eterm tid;
-    Eterm* prev_continuation_tptr;
-} select_replace_context_t;
-
-static int select_replace_on_nothing_can_match(match_callbacks_t* ctx_base,
+static int select_replace_on_nothing_can_match(traverse_context_t* ctx_base,
                                                Eterm* ret)
 {
     *ret = make_small(0);
     return DB_ERROR_NONE;
 }
 
-static int select_replace_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
+static int select_replace_on_match_res(traverse_context_t* ctx, Sint slot_ix,
                                        HashDbTerm*** current_ptr_ptr,
                                        Eterm match_res)
 {
-    select_replace_context_t* ctx = (select_replace_context_t*) ctx_base;
     DbTableHash* tb = ctx->tb;
     HashDbTerm* new;
     HashDbTerm* next;
@@ -2183,11 +2188,10 @@ static int select_replace_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix
     return 0;
 }
 
-static int select_replace_on_loop_ended(match_callbacks_t* ctx_base, Sint slot_ix,
+static int select_replace_on_loop_ended(traverse_context_t* ctx, Sint slot_ix,
                                         Sint got, Sint iterations_left,
                                         Binary** mpp, Eterm* ret)
 {
-    select_replace_context_t* ctx = (select_replace_context_t*) ctx_base;
     ASSERT(iterations_left <= MAX_SELECT_REPLACE_ITERATIONS);
     /* the more objects we've replaced, the more reductions we've consumed */
     BUMP_REDS(ctx->p,
@@ -2197,23 +2201,20 @@ static int select_replace_on_loop_ended(match_callbacks_t* ctx_base, Sint slot_i
     return DB_ERROR_NONE;
 }
 
-static int select_replace_on_trap(match_callbacks_t* ctx_base,
+static int select_replace_on_trap(traverse_context_t* ctx,
                                   Sint slot_ix, Sint got,
                                   Binary** mpp, Eterm* ret)
 {
-    select_replace_context_t* ctx = (select_replace_context_t*) ctx_base;
     return on_simple_trap(
-            &ets_select_replace_continue_exp,
-            ctx->p,
-            ctx->tb,
-            ctx->tid,
-            ctx->prev_continuation_tptr,
+            &ets_select_replace_continue_exp, ctx,
             slot_ix, got, mpp, ret);
 }
 
-static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern, Eterm *ret)
+static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid,
+                                  Eterm pattern, Eterm *ret,
+                                  enum DbIterSafety safety)
 {
-    select_replace_context_t ctx;
+    traverse_context_t ctx;
     Sint chunk_size = 0;
 
     /* Bag implementation presented both semantic consistency and performance issues,
@@ -2221,29 +2222,32 @@ static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pat
      */
     ASSERT(!(tbl->hash.common.status & DB_BAG));
 
-    ctx.base.on_nothing_can_match = select_replace_on_nothing_can_match;
-    ctx.base.on_match_res         = select_replace_on_match_res;
-    ctx.base.on_loop_ended        = select_replace_on_loop_ended;
-    ctx.base.on_trap              = select_replace_on_trap;
+    ctx.on_nothing_can_match = select_replace_on_nothing_can_match;
+    ctx.on_match_res         = select_replace_on_match_res;
+    ctx.on_loop_ended        = select_replace_on_loop_ended;
+    ctx.on_trap              = select_replace_on_trap;
     ctx.p = p;
     ctx.tb = &tbl->hash;
     ctx.tid = tid;
     ctx.prev_continuation_tptr = NULL;
+    ctx.safety = safety;
 
     return match_traverse(
-            ctx.p, ctx.tb,
+            &ctx,
             pattern, db_match_keeps_key,
             chunk_size,
             MAX_SELECT_REPLACE_ITERATIONS, NULL, 1,
-            &ctx.base, ret);
+            ret);
 }
 
 /*
  * This is called when select_replace traps
  */
-static int db_select_replace_continue_hash(Process* p, DbTable* tbl, Eterm continuation, Eterm* ret)
+static int db_select_replace_continue_hash(Process* p, DbTable* tbl,
+                                           Eterm continuation, Eterm* ret,
+                                           enum DbIterSafety* safety_p)
 {
-    select_replace_context_t ctx;
+    traverse_context_t ctx;
     Eterm* tptr;
     Eterm tid ;
     Binary* mp;
@@ -2252,25 +2256,27 @@ static int db_select_replace_continue_hash(Process* p, DbTable* tbl, Eterm conti
     Sint chunk_size = 0;
     *ret = NIL;
 
-    if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
+    if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp,
+                                   &got, safety_p)) {
         *ret = NIL;
         return DB_ERROR_BADPARAM;
     }
 
     /* Proceed */
-    ctx.base.on_match_res  = select_replace_on_match_res;
-    ctx.base.on_loop_ended = select_replace_on_loop_ended;
-    ctx.base.on_trap       = select_replace_on_trap;
+    ctx.on_match_res  = select_replace_on_match_res;
+    ctx.on_loop_ended = select_replace_on_loop_ended;
+    ctx.on_trap       = select_replace_on_trap;
     ctx.p = p;
     ctx.tb = &tbl->hash;
     ctx.tid = tid;
     ctx.prev_continuation_tptr = tptr;
+    ctx.safety = *safety_p;
 
     return match_traverse_continue(
-            ctx.p, ctx.tb, chunk_size,
+            &ctx, chunk_size,
             MAX_SELECT_REPLACE_ITERATIONS,
             NULL, slot_ix, got, &mp, 1,
-            &ctx.base, ret);
+            ret);
 }
 
 
@@ -2310,7 +2316,7 @@ static int db_take_hash(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
     }
     WUNLOCK_HASH(lck);
     if (nitems_diff) {
-        erts_atomic_add_nob(&tb->common.nitems, nitems_diff);
+        ADD_NITEMS(tb, nitems_diff);
         try_shrink(tb);
     }
     free_term_list(tb, free_us);
@@ -2370,7 +2376,7 @@ static SWord db_mark_all_deleted_hash(DbTable *tbl, SWord reds)
     fixdel->slot = NACTIVE(tb) - 1;
     fixdel->all = 1;
     fixdel->trap = 0;
-    erts_atomic_set_nob(&tb->common.nitems, 0);
+    RESET_NITEMS(tb);
     return loops < 0 ? 0 : loops / LOOPS_PER_REDUCTION;
 }
 
@@ -2478,7 +2484,8 @@ static SWord db_free_table_continue_hash(DbTable *tbl, SWord reds)
 		     (void*)tb->locks, sizeof(DbTableHashFineLocks));
 	tb->locks = NULL;
     }
-    ASSERT(erts_atomic_read_nob(&tb->common.memory_size) == sizeof(DbTable));
+    ASSERT(sizeof(DbTable) == erts_flxctr_read_approx(&tb->common.counters,
+                                                      ERTS_DB_TABLE_MEM_COUNTER_ID));
     return reds;			/* Done */
 }
 
@@ -2731,13 +2738,9 @@ static int free_seg(DbTableHash *tb, int free_records)
                  * sure no lingering threads are still hanging in BUCKET macro
                  * with an old segtab pointer.
                  */
-                Uint sz = SIZEOF_EXT_SEGTAB(est->nsegs);
-                ASSERT(sz == ERTS_ALC_DBG_BLK_SZ(est));
-                ERTS_DB_ALC_MEM_UPDATE_(tb, sz, 0);
-                erts_schedule_thr_prgr_later_cleanup_op(dealloc_ext_segtab,
-                                                        est,
-                                                        &est->lop,
-                                                        sz);
+                erts_schedule_db_free(&tb->common, dealloc_ext_segtab,
+                                      est, &est->lop,
+                                      SIZEOF_EXT_SEGTAB(est->nsegs));
             }
             else
                 erts_db_free(ERTS_ALC_T_DB_SEG, (DbTable*)tb, est,
@@ -3094,7 +3097,7 @@ db_lookup_dbterm_hash(Process *p, DbTable *tbl, Eterm key, Eterm obj,
             ASSERT(q->hvalue == hval);
             q->pseudo_deleted = 0;
             *bp = b = q;
-            erts_atomic_inc_nob(&tb->common.nitems);
+            INC_NITEMS(tb);
         }
 
         HRelease(p, hend, htop);
@@ -3107,7 +3110,7 @@ Ldone:
     handle->dbterm = &b->dbterm;
     handle->flags = flags;
     handle->new_size = b->dbterm.size;
-    handle->lck = lck;
+    handle->u.hash.lck = lck;
     return 1;
 }
 
@@ -3120,7 +3123,7 @@ db_finalize_dbterm_hash(int cret, DbUpdateHandle* handle)
     DbTableHash *tb = &tbl->hash;
     HashDbTerm **bp = (HashDbTerm **) handle->bp;
     HashDbTerm *b = *bp;
-    erts_rwmtx_t* lck = (erts_rwmtx_t*) handle->lck;
+    erts_rwmtx_t* lck = handle->u.hash.lck;
     HashDbTerm* free_me = NULL;
 
     ERTS_LC_ASSERT(IS_HASH_WLOCKED(tb, lck));  /* locked by db_lookup_dbterm_hash */
@@ -3137,7 +3140,7 @@ db_finalize_dbterm_hash(int cret, DbUpdateHandle* handle)
         }
 
         WUNLOCK_HASH(lck);
-        erts_atomic_dec_nob(&tb->common.nitems);
+        DEC_NITEMS(tb);
         try_shrink(tb);
     } else {
         if (handle->flags & DB_MUST_RESIZE) {
@@ -3146,7 +3149,7 @@ db_finalize_dbterm_hash(int cret, DbUpdateHandle* handle)
         }
         if (handle->flags & DB_INC_TRY_GROW) {
             int nactive;
-            int nitems = erts_atomic_inc_read_nob(&tb->common.nitems);
+            int nitems = INC_NITEMS(tb);
             WUNLOCK_HASH(lck);
             nactive = NACTIVE(tb);
 
@@ -3167,8 +3170,17 @@ db_finalize_dbterm_hash(int cret, DbUpdateHandle* handle)
     return;
 }
 
-static SWord db_delete_all_objects_hash(Process* p, DbTable* tbl, SWord reds)
+static SWord db_delete_all_objects_hash(Process* p,
+                                        DbTable* tbl,
+                                        SWord reds,
+                                        Eterm* nitems_holder_wb)
 {
+    if (nitems_holder_wb != NULL) {
+        Uint nr_of_items =
+            erts_flxctr_read_centralized(&tbl->common.counters,
+                                         ERTS_DB_TABLE_NITEMS_COUNTER_ID);
+        *nitems_holder_wb = erts_make_integer(nr_of_items, p);
+    }
     if (IS_FIXED(tbl)) {
 	reds = db_mark_all_deleted_hash(tbl, reds);
     } else {
@@ -3177,11 +3189,16 @@ static SWord db_delete_all_objects_hash(Process* p, DbTable* tbl, SWord reds)
             return reds;
 
 	db_create_hash(p, tbl);
-	erts_atomic_set_nob(&tbl->hash.common.nitems, 0);
+        RESET_NITEMS(tbl);
     }
     return reds;
 }
 
+static Eterm db_delete_all_objects_get_nitems_from_holder_hash(Process* p,
+                                                               Eterm nitems_holder){
+    return nitems_holder;
+}
+
 void db_foreach_offheap_hash(DbTable *tbl,
 			     void (*func)(ErlOffHeap *, void *),
 			     void * arg)
@@ -3245,6 +3262,12 @@ Eterm erts_ets_hash_sizeof_ext_segtab(void)
     return make_small(((SIZEOF_EXT_SEGTAB(0)-1) / sizeof(UWord)) + 1);
 }
 
+void
+erts_db_foreach_thr_prgr_offheap_hash(void (*func)(ErlOffHeap *, void *),
+                                      void *arg)
+{
+}
+
 #ifdef ERTS_ENABLE_LOCK_COUNT
 void erts_lcnt_enable_db_hash_lock_count(DbTableHash *tb, int enable) {
     int i;
diff --git a/erts/emulator/beam/erl_db_hash.h b/erts/emulator/beam/erl_db_hash.h
index eae5537ba4..9759d8b466 100644
--- a/erts/emulator/beam/erl_db_hash.h
+++ b/erts/emulator/beam/erl_db_hash.h
@@ -110,6 +110,9 @@ typedef struct {
 
 void db_calc_stats_hash(DbTableHash* tb, DbHashStats*);
 Eterm erts_ets_hash_sizeof_ext_segtab(void);
+void
+erts_db_foreach_thr_prgr_offheap_hash(void (*func)(ErlOffHeap *, void *),
+                                      void *arg);
 
 #ifdef ERTS_ENABLE_LOCK_COUNT
 void erts_lcnt_enable_db_hash_lock_count(DbTableHash *tb, int enable);
diff --git a/erts/emulator/beam/erl_db_tree.c b/erts/emulator/beam/erl_db_tree.c
index 45e4be2426..19b94b0634 100644
--- a/erts/emulator/beam/erl_db_tree.c
+++ b/erts/emulator/beam/erl_db_tree.c
@@ -48,33 +48,23 @@
 #include "erl_binary.h"
 
 #include "erl_db_tree.h"
+#include "erl_db_tree_util.h"
 
 #define GETKEY_WITH_POS(Keypos, Tplp) (*((Tplp) + Keypos))
-#define NITEMS(tb) ((int)erts_atomic_read_nob(&(tb)->common.nitems))
 
-/*
-** A stack of this size is enough for an AVL tree with more than
-** 0xFFFFFFFF elements. May be subject to change if
-** the datatype of the element counter is changed to a 64 bit integer.
-** The Maximal height of an AVL tree is calculated as:
-** h(n) <= 1.4404 * log(n + 2) - 0.328
-** Where n denotes the number of nodes, h(n) the height of the tree
-** with n nodes and log is the binary logarithm.
-*/
-
-#define STACK_NEED 50
-#define TREE_MAX_ELEMENTS 0xFFFFFFFFUL
-
-#define PUSH_NODE(Dtt, Tdt)                     \
-    ((Dtt)->array[(Dtt)->pos++] = Tdt)
-
-#define POP_NODE(Dtt)			\
-     (((Dtt)->pos) ? 			\
-      (Dtt)->array[--((Dtt)->pos)] : NULL)
-
-#define TOP_NODE(Dtt)                   \
-     ((Dtt->pos) ? 			\
-      (Dtt)->array[(Dtt)->pos - 1] : NULL)
+#define NITEMS_CENTRALIZED(tb)                                          \
+    ((Sint)erts_flxctr_read_centralized(&(tb)->common.counters,          \
+                                        ERTS_DB_TABLE_NITEMS_COUNTER_ID))
+#define ADD_NITEMS(DB, TO_ADD)                                          \
+    erts_flxctr_add(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID, TO_ADD)
+#define INC_NITEMS(DB)                                                  \
+    erts_flxctr_inc(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID)
+#define INC_NITEMS_CENTRALIZED(DB)                                      \
+    erts_flxctr_inc_read_centralized(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID)
+#define RESET_NITEMS(DB)                                                \
+    erts_flxctr_reset(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID)
+#define IS_CENTRALIZED_CTR(tb) (!(tb)->common.counters.is_decentralized)
+#define APPROX_MEM_CONSUMED(tb) erts_flxctr_read_approx(&(tb)->common.counters, ERTS_DB_TABLE_MEM_COUNTER_ID)
 
 #define TOPN_NODE(Dtt, Pos)                   \
      (((Pos) < Dtt->pos) ? 			\
@@ -89,10 +79,12 @@
 /* Obtain table static stack if available. NULL if not.
 ** Must be released with release_stack()
 */
-static DbTreeStack* get_static_stack(DbTableTree* tb)
+ERTS_INLINE static DbTreeStack* get_static_stack(DbTableTree* tb)
 {
-    if (!erts_atomic_xchg_acqb(&tb->is_stack_busy, 1)) {
-	return &tb->static_stack;
+    if (tb != NULL) {
+        ASSERT(IS_TREE_TABLE(tb->common.type));
+        if (!erts_atomic_xchg_acqb(&tb->is_stack_busy, 1))
+            return &tb->static_stack;
     }
     return NULL;
 }
@@ -100,13 +92,15 @@ static DbTreeStack* get_static_stack(DbTableTree* tb)
 /* Obtain static stack if available, otherwise empty dynamic stack.
 ** Must be released with release_stack()
 */
-static DbTreeStack* get_any_stack(DbTableTree* tb)
+static DbTreeStack* get_any_stack(DbTable* tb, DbTableTree* stack_container)
 {
     DbTreeStack* stack;
-    if (!erts_atomic_xchg_acqb(&tb->is_stack_busy, 1)) {
-	return &tb->static_stack;
+    if (stack_container != NULL) {
+        ASSERT(IS_TREE_TABLE(stack_container->common.type));
+        if (!erts_atomic_xchg_acqb(&stack_container->is_stack_busy, 1))
+            return &stack_container->static_stack;
     }
-    stack = erts_db_alloc(ERTS_ALC_T_DB_STK, (DbTable *) tb,
+    stack = erts_db_alloc(ERTS_ALC_T_DB_STK, tb,
 			  sizeof(DbTreeStack) + sizeof(TreeDbTerm*) * STACK_NEED);
     stack->pos = 0;
     stack->slot = 0;
@@ -114,62 +108,62 @@ static DbTreeStack* get_any_stack(DbTableTree* tb)
     return stack;
 }
 
-static void release_stack(DbTableTree* tb, DbTreeStack* stack)
+static void release_stack(DbTable* tb, DbTableTree* stack_container, DbTreeStack* stack)
 {
-    if (stack == &tb->static_stack) {
-	ASSERT(erts_atomic_read_nob(&tb->is_stack_busy) == 1);
-	erts_atomic_set_relb(&tb->is_stack_busy, 0);
-    }
-    else {
-	erts_db_free(ERTS_ALC_T_DB_STK, (DbTable *) tb,
-		     (void *) stack, sizeof(DbTreeStack) + sizeof(TreeDbTerm*) * STACK_NEED);
+    if (stack_container != NULL) {
+        ASSERT(IS_TREE_TABLE(stack_container->common.type));
+        if (stack == &stack_container->static_stack) {
+            ASSERT(erts_atomic_read_nob(&stack_container->is_stack_busy) == 1);
+            erts_atomic_set_relb(&stack_container->is_stack_busy, 0);
+            return;
+        }
     }
+    erts_db_free(ERTS_ALC_T_DB_STK, tb,
+                 (void *) stack, sizeof(DbTreeStack) + sizeof(TreeDbTerm*) * STACK_NEED);
 }
 
-static ERTS_INLINE void reset_static_stack(DbTableTree* tb)
+static ERTS_INLINE void reset_stack(DbTreeStack* stack)
 {
-    tb->static_stack.pos = 0;
-    tb->static_stack.slot = 0;
+    if (stack != NULL) {
+        stack->pos = 0;
+        stack->slot = 0;
+    }
 }
 
-static ERTS_INLINE void free_term(DbTableTree *tb, TreeDbTerm* p)
+static ERTS_INLINE void reset_static_stack(DbTableTree* tb)
 {
-    db_free_term((DbTable*)tb, p, offsetof(TreeDbTerm, dbterm));
+    if (tb != NULL) {
+        ASSERT(IS_TREE_TABLE(tb->common.type));
+        reset_stack(&tb->static_stack);
+    }
 }
 
-static ERTS_INLINE TreeDbTerm* new_dbterm(DbTableTree *tb, Eterm obj)
+static ERTS_INLINE TreeDbTerm* new_dbterm(DbTableCommon *tb, Eterm obj)
 {
     TreeDbTerm* p;
-    if (tb->common.compress) {
-	p = db_store_term_comp(&tb->common, NULL, offsetof(TreeDbTerm,dbterm), obj);
+    if (tb->compress) {
+	p = db_store_term_comp(tb, NULL, offsetof(TreeDbTerm,dbterm), obj);
     }
     else {
-	p = db_store_term(&tb->common, NULL, offsetof(TreeDbTerm,dbterm), obj);
+	p = db_store_term(tb, NULL, offsetof(TreeDbTerm,dbterm), obj);
     }
     return p;
 }
-static ERTS_INLINE TreeDbTerm* replace_dbterm(DbTableTree *tb, TreeDbTerm* old,
+static ERTS_INLINE TreeDbTerm* replace_dbterm(DbTableCommon *tb, TreeDbTerm* old,
 					      Eterm obj)
 {
     TreeDbTerm* p;
     ASSERT(old != NULL);
-    if (tb->common.compress) {
-	p = db_store_term_comp(&tb->common, &(old->dbterm), offsetof(TreeDbTerm,dbterm), obj);
+    if (tb->compress) {
+	p = db_store_term_comp(tb, &(old->dbterm), offsetof(TreeDbTerm,dbterm), obj);
     }
     else {
-	p = db_store_term(&tb->common, &(old->dbterm), offsetof(TreeDbTerm,dbterm), obj);
+	p = db_store_term(tb, &(old->dbterm), offsetof(TreeDbTerm,dbterm), obj);
     }
     return p;
 }
 
 /*
-** Some macros for "direction stacks"
-*/
-#define DIR_LEFT 0
-#define DIR_RIGHT 1
-#define DIR_END 2 
-
-/*
  * Number of records to delete before trapping.
  */
 #define DELETE_RECORD_LIMIT 12000
@@ -208,31 +202,37 @@ static void do_dump_tree2(DbTableTree*, int to, void *to_arg, int show,
 ** Datatypes
 */
 
+enum ms_key_boundness {
+    /* Order significant, larger means more "boundness" => less iteration */
+    MS_KEY_UNBOUND           = 0,
+    MS_KEY_PARTIALLY_BOUND   = 1,
+    MS_KEY_BOUND             = 2,
+    MS_KEY_IMPOSSIBLE        = 3
+};
+
 /* 
  * This structure is filled in by analyze_pattern() for the select 
  * functions.
  */
 struct mp_info {
-    int something_can_match;	/* The match_spec is not "impossible" */
-    int some_limitation;	/* There is some limitation on the search
-				 * area, i. e. least and/or most is set.*/
-    int got_partial;		/* The limitation has a partially bound
-				 * key */
+    enum ms_key_boundness key_boundness;
     Eterm least;		/* The lowest matching key (possibly 
 				 * partially bound expression) */
     Eterm most;                 /* The highest matching key (possibly 
 				 * partially bound expression) */
-
-    TreeDbTerm **save_term;      /* If the key is completely bound, this
-	 			  * will be the Tree node we're searching
-				  * for, otherwise it will be useless */
     Binary *mp;                 /* The compiled match program */
 };
 
+struct select_common {
+    TreeDbTerm **root;
+};
+
+
 /*
  * Used by doit_select(_chunk)
  */
 struct select_context {
+    struct select_common common;
     Process *p;
     Eterm accum;
     Binary *mp;
@@ -248,6 +248,7 @@ struct select_context {
  * Used by doit_select_count
  */
 struct select_count_context {
+    struct select_common common;
     Process *p;
     Binary *mp;
     Eterm end_condition;
@@ -261,8 +262,10 @@ struct select_count_context {
  * Used by doit_select_delete
  */
 struct select_delete_context {
+    struct select_common common;
     Process *p;
-    DbTableTree *tb;
+    DbTableCommon *tb;
+    DbTreeStack *stack;
     Uint accum;
     Binary *mp;
     Eterm end_condition;
@@ -276,8 +279,9 @@ struct select_delete_context {
  * Used by doit_select_replace
  */
 struct select_replace_context {
+    struct select_common common;
     Process *p;
-    DbTableTree *tb;
+    DbTableCommon *tb;
     Binary *mp;
     Eterm end_condition;
     Eterm *lastobj;
@@ -292,75 +296,83 @@ typedef int (*extra_match_validator_t)(int keypos, Eterm match, Eterm guard, Ete
 /*
 ** Forward declarations 
 */
-static TreeDbTerm *linkout_tree(DbTableTree *tb, Eterm key);
-static TreeDbTerm *linkout_object_tree(DbTableTree *tb, 
-				       Eterm object);
+static TreeDbTerm *linkout_tree(DbTableCommon *tb, TreeDbTerm **root,
+                                Eterm key, DbTreeStack *stack);
+static TreeDbTerm *linkout_object_tree(DbTableCommon *tb,  TreeDbTerm **root,
+				       Eterm object, DbTableTree *stack);
 static SWord do_free_tree_continue(DbTableTree *tb, SWord reds);
-static void free_term(DbTableTree *tb, TreeDbTerm* p);
-static int balance_left(TreeDbTerm **this); 
-static int balance_right(TreeDbTerm **this); 
+static void free_term(DbTable *tb, TreeDbTerm* p);
+int tree_balance_left(TreeDbTerm **this); 
+int tree_balance_right(TreeDbTerm **this); 
 static int delsub(TreeDbTerm **this); 
-static TreeDbTerm *slot_search(Process *p, DbTableTree *tb, Sint slot);
-static TreeDbTerm *find_node(DbTableTree *tb, Eterm key);
-static TreeDbTerm **find_node2(DbTableTree *tb, Eterm key);
-static TreeDbTerm **find_ptr(DbTableTree *tb, DbTreeStack*, TreeDbTerm *this);
-static TreeDbTerm *find_next(DbTableTree *tb, DbTreeStack*, Eterm key);
-static TreeDbTerm *find_prev(DbTableTree *tb, DbTreeStack*, Eterm key);
-static TreeDbTerm *find_next_from_pb_key(DbTableTree *tb, DbTreeStack*,
-					 Eterm key);
-static TreeDbTerm *find_prev_from_pb_key(DbTableTree *tb, DbTreeStack*,
-					 Eterm key);
-static void traverse_backwards(DbTableTree *tb,
+static TreeDbTerm *slot_search(Process *p, TreeDbTerm *root, Sint slot,
+                               DbTable *tb, DbTableTree *stack_container,
+                               CATreeRootIterator *iter, int* is_EOT);
+static TreeDbTerm *find_node(DbTableCommon *tb, TreeDbTerm *root,
+                             Eterm key, DbTableTree *stack_container);
+static TreeDbTerm **find_node2(DbTableCommon *tb, TreeDbTerm **root, Eterm key);
+static TreeDbTerm **find_ptr(DbTableCommon *tb, TreeDbTerm **root,
+                             DbTreeStack *stack, TreeDbTerm *this);
+static TreeDbTerm *find_next(DbTableCommon *tb, TreeDbTerm *root,
+                             DbTreeStack* stack, Eterm key);
+static TreeDbTerm *find_prev(DbTableCommon *tb, TreeDbTerm *root,
+                             DbTreeStack* stack, Eterm key);
+static TreeDbTerm *find_next_from_pb_key(DbTable*, TreeDbTerm*** rootpp,
+                                         DbTreeStack* stack, Eterm key,
+                                         CATreeRootIterator*);
+static TreeDbTerm *find_prev_from_pb_key(DbTable*,  TreeDbTerm*** rootpp,
+                                         DbTreeStack* stack, Eterm key,
+                                         CATreeRootIterator*);
+typedef int traverse_doit_funcT(DbTableCommon*, TreeDbTerm*,
+                                struct select_common*, int forward);
+
+static void traverse_backwards(DbTableCommon *tb,
 			       DbTreeStack*,
 			       Eterm lastkey,
-			       int (*doit)(DbTableTree *tb,
-					   TreeDbTerm *,
-					   void *,
-					   int),
-			       void *context); 
-static void traverse_forward(DbTableTree *tb,
+			       traverse_doit_funcT*,
+			       struct select_common *context,
+                               CATreeRootIterator*);
+static void traverse_forward(DbTableCommon *tb,
 			     DbTreeStack*,
 			     Eterm lastkey,
-			     int (*doit)(DbTableTree *tb,
-					 TreeDbTerm *,
-					 void *,
-					 int),
-			     void *context);
-static void traverse_update_backwards(DbTableTree *tb,
+                             traverse_doit_funcT*,
+			     struct select_common *context,
+                             CATreeRootIterator*);
+static void traverse_update_backwards(DbTableCommon *tb,
                                       DbTreeStack*,
                                       Eterm lastkey,
-                                      int (*doit)(DbTableTree *tb,
+                                      int (*doit)(DbTableCommon *tb,
                                                   TreeDbTerm **, // out
-                                                  void *,
+                                                  struct select_common*,
                                                   int),
-                                      void *context);
-static int key_given(DbTableTree *tb, Eterm pattern, TreeDbTerm ***ret,
-		     Eterm *partly_bound_key);
-static Sint cmp_partly_bound(Eterm partly_bound_key, Eterm bound_key);
+                                      struct select_common*,
+                                      CATreeRootIterator*);
+static enum ms_key_boundness key_boundness(DbTableCommon *tb,
+                                           Eterm pattern, Eterm *keyp);
 static Sint do_cmp_partly_bound(Eterm a, Eterm b, int *done);
 
-static int analyze_pattern(DbTableTree *tb, Eterm pattern, 
+static int analyze_pattern(DbTableCommon *tb, Eterm pattern,
                            extra_match_validator_t extra_validator, /* Optional callback */
                            struct mp_info *mpi);
-static int doit_select(DbTableTree *tb,
-		       TreeDbTerm *this,
-		       void *ptr,
+static int doit_select(DbTableCommon *tb,
+                       TreeDbTerm *this,
+                       struct select_common* ptr,
 		       int forward);
-static int doit_select_count(DbTableTree *tb,
+static int doit_select_count(DbTableCommon *tb,
 			     TreeDbTerm *this,
-			     void *ptr,
+                             struct select_common*,
 			     int forward);
-static int doit_select_chunk(DbTableTree *tb,
+static int doit_select_chunk(DbTableCommon *tb,
 			     TreeDbTerm *this,
-			     void *ptr,
+                             struct select_common*,
 			     int forward);
-static int doit_select_delete(DbTableTree *tb,
+static int doit_select_delete(DbTableCommon *tb,
 			      TreeDbTerm *this,
-			      void *ptr,
+			      struct select_common*,
 			      int forward);
-static int doit_select_replace(DbTableTree *tb,
+static int doit_select_replace(DbTableCommon *tb,
                                TreeDbTerm **this_ptr,
-                               void *ptr,
+                               struct select_common*,
                                int forward);
 
 static int partly_bound_can_match_lesser(Eterm partly_bound_1, 
@@ -396,24 +408,31 @@ static int db_erase_object_tree(DbTable *tbl, Eterm object,Eterm *ret);
 static int db_slot_tree(Process *p, DbTable *tbl, 
 			Eterm slot_term,  Eterm *ret);
 static int db_select_tree(Process *p, DbTable *tbl, Eterm tid,
-			  Eterm pattern, int reversed, Eterm *ret);
+			  Eterm pattern, int reversed, Eterm *ret,
+                          enum DbIterSafety);
 static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
-				Eterm pattern,  Eterm *ret);
+				Eterm pattern,  Eterm *ret, enum DbIterSafety);
 static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
 				Eterm pattern, Sint chunk_size,
-				int reversed, Eterm *ret);
+				int reversed, Eterm *ret, enum DbIterSafety);
 static int db_select_continue_tree(Process *p, DbTable *tbl,
-				   Eterm continuation, Eterm *ret);
+				   Eterm continuation, Eterm *ret,
+                                   enum DbIterSafety*);
 static int db_select_count_continue_tree(Process *p, DbTable *tbl,
-					 Eterm continuation, Eterm *ret);
+					 Eterm continuation, Eterm *ret,
+                                         enum DbIterSafety*);
 static int db_select_delete_tree(Process *p, DbTable *tbl, Eterm tid,
-				 Eterm pattern,  Eterm *ret);
+				 Eterm pattern,  Eterm *ret,
+                                 enum DbIterSafety);
 static int db_select_delete_continue_tree(Process *p, DbTable *tbl, 
-					  Eterm continuation, Eterm *ret);
+					  Eterm continuation, Eterm *ret,
+                                          enum DbIterSafety*);
 static int db_select_replace_tree(Process *p, DbTable *tbl, Eterm tid,
-                                  Eterm pattern, Eterm *ret);
+                                  Eterm pattern, Eterm *ret,
+                                  enum DbIterSafety);
 static int db_select_replace_continue_tree(Process *p, DbTable *tbl,
-                                           Eterm continuation, Eterm *ret);
+                                           Eterm continuation, Eterm *ret,
+                                           enum DbIterSafety*);
 static int db_take_tree(Process *, DbTable *, Eterm, Eterm *);
 static void db_print_tree(fmtfn_t to, void *to_arg,
 			  int show, DbTable *tbl);
@@ -425,8 +444,12 @@ static void db_foreach_offheap_tree(DbTable *,
 				    void (*)(ErlOffHeap *, void *),
 				    void *);
 
-static SWord db_delete_all_objects_tree(Process* p, DbTable* tbl, SWord reds);
-
+static SWord db_delete_all_objects_tree(Process* p,
+                                        DbTable* tbl,
+                                        SWord reds,
+                                        Eterm* nitems_holder_wb);
+static Eterm db_delete_all_objects_get_nitems_from_holder_tree(Process* p,
+                                                               Eterm nitems_holder);
 #ifdef HARDDEBUG
 static void db_check_table_tree(DbTable *tbl);
 #endif
@@ -470,6 +493,7 @@ DbTableMethod db_tree =
     db_select_replace_continue_tree,
     db_take_tree,
     db_delete_all_objects_tree,
+    db_delete_all_objects_get_nitems_from_holder_tree,
     db_free_empty_table_tree,
     db_free_table_continue_tree,
     db_print_tree,
@@ -508,18 +532,18 @@ int db_create_tree(Process *p, DbTable *tbl)
     return DB_ERROR_NONE;
 }
 
-static int db_first_tree(Process *p, DbTable *tbl, Eterm *ret)
+int db_first_tree_common(Process *p, DbTable *tbl, TreeDbTerm *root,
+                         Eterm *ret, DbTableTree *stack_container)
 {
-    DbTableTree *tb = &tbl->tree;
     DbTreeStack* stack;
     TreeDbTerm *this;
 
-    if (( this = tb->root ) == NULL) {
+    if (( this = root ) == NULL) {
 	*ret = am_EOT;
 	return DB_ERROR_NONE;
     }
     /* Walk down the tree to the left */
-    if ((stack = get_static_stack(tb)) != NULL) {
+    if ((stack = get_static_stack(stack_container)) != NULL) {
 	stack->pos = stack->slot = 0;
     }
     while (this->left != NULL) {
@@ -529,23 +553,27 @@ static int db_first_tree(Process *p, DbTable *tbl, Eterm *ret)
     if (stack) {
 	PUSH_NODE(stack, this);
 	stack->slot = 1;
-	release_stack(tb,stack);
+	release_stack(tbl,stack_container,stack);
     }
     *ret = db_copy_key(p, tbl, &this->dbterm);
     return DB_ERROR_NONE;
 }
 
-static int db_next_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+static int db_first_tree(Process *p, DbTable *tbl, Eterm *ret)
 {
     DbTableTree *tb = &tbl->tree;
-    DbTreeStack* stack;
+    return db_first_tree_common(p, tbl, tb->root, ret, tb);
+}
+
+int db_next_tree_common(Process *p, DbTable *tbl,
+                        TreeDbTerm *root, Eterm key,
+                        Eterm *ret, DbTreeStack* stack)
+{
     TreeDbTerm *this;
 
-    if (is_atom(key) && key == am_EOT)
+    if (key == am_EOT)
 	return DB_ERROR_BADKEY;
-    stack = get_any_stack(tb);
-    this = find_next(tb, stack, key);
-    release_stack(tb,stack);
+    this = find_next(&tbl->common, root, stack, key);
     if (this == NULL) {
 	*ret = am_EOT;
 	return DB_ERROR_NONE;
@@ -554,18 +582,27 @@ static int db_next_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
     return DB_ERROR_NONE;
 }
 
-static int db_last_tree(Process *p, DbTable *tbl, Eterm *ret)
+static int db_next_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
 {
     DbTableTree *tb = &tbl->tree;
+    DbTreeStack* stack = get_any_stack(tbl, tb);
+    int ret_val = db_next_tree_common(p, tbl, tb->root, key, ret, stack);
+    release_stack(tbl,tb,stack);
+    return ret_val;
+}
+
+int db_last_tree_common(Process *p, DbTable *tbl, TreeDbTerm *root,
+                        Eterm *ret, DbTableTree *stack_container)
+{
     TreeDbTerm *this;
     DbTreeStack* stack;
 
-    if (( this = tb->root ) == NULL) {
+    if (( this = root ) == NULL) {
 	*ret = am_EOT;
 	return DB_ERROR_NONE;
     }
     /* Walk down the tree to the right */
-    if ((stack = get_static_stack(tb)) != NULL) {
+    if ((stack = get_static_stack(stack_container)) != NULL) {
 	stack->pos = stack->slot = 0;
     }    
     while (this->right != NULL) {
@@ -574,24 +611,28 @@ static int db_last_tree(Process *p, DbTable *tbl, Eterm *ret)
     }
     if (stack) {
 	PUSH_NODE(stack, this);
-	stack->slot = NITEMS(tb);
-	release_stack(tb,stack);
+        /* Always centralized counters when static stack is used */
+	stack->slot = NITEMS_CENTRALIZED(tbl);
+	release_stack(tbl,stack_container,stack);
     }
     *ret = db_copy_key(p, tbl, &this->dbterm);
     return DB_ERROR_NONE;
 }
 
-static int db_prev_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+static int db_last_tree(Process *p, DbTable *tbl, Eterm *ret)
 {
     DbTableTree *tb = &tbl->tree;
+    return db_last_tree_common(p, tbl, tb->root, ret, tb);
+}
+
+int db_prev_tree_common(Process *p, DbTable *tbl, TreeDbTerm *root, Eterm key,
+                 Eterm *ret, DbTreeStack* stack)
+{
     TreeDbTerm *this;
-    DbTreeStack* stack;
 
-    if (is_atom(key) && key == am_EOT)
+    if (key == am_EOT)
 	return DB_ERROR_BADKEY;
-    stack = get_any_stack(tb);
-    this = find_prev(tb, stack, key);
-    release_stack(tb,stack);
+    this = find_prev(&tbl->common, root, stack, key);
     if (this == NULL) {
 	*ret = am_EOT;
 	return DB_ERROR_NONE;
@@ -600,25 +641,30 @@ static int db_prev_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
     return DB_ERROR_NONE;
 }
 
-static ERTS_INLINE Sint cmp_key(DbTableTree* tb, Eterm key, TreeDbTerm* obj) {
-    return CMP(key, GETKEY(tb,obj->dbterm.tpl));
+static int db_prev_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+{
+    DbTableTree *tb = &tbl->tree;
+    DbTreeStack* stack = get_any_stack(tbl, tb);
+    int res = db_prev_tree_common(p, tbl, tb->root, key, ret, stack);
+    release_stack(tbl,tb,stack);
+    return res;
 }
 
-static ERTS_INLINE int cmp_key_eq(DbTableTree* tb, Eterm key, TreeDbTerm* obj) {
+static ERTS_INLINE int cmp_key_eq(DbTableCommon* tb, Eterm key, TreeDbTerm* obj) {
     Eterm obj_key = GETKEY(tb,obj->dbterm.tpl);
     return is_same(key, obj_key) || CMP(key, obj_key) == 0;
 }
 
-static int db_put_tree(DbTable *tbl, Eterm obj, int key_clash_fail)
+int db_put_tree_common(DbTableCommon *tb, TreeDbTerm **root, Eterm obj,
+                       int key_clash_fail, DbTableTree *stack_container)
 {
-    DbTableTree *tb = &tbl->tree;
     /* Non recursive insertion in AVL tree, building our own stack */
     TreeDbTerm **tstack[STACK_NEED];
     int tpos = 0;
     int dstack[STACK_NEED+1];
     int dpos = 0;
     int state = 0;
-    TreeDbTerm **this = &tb->root;
+    TreeDbTerm **this = root;
     Sint c;
     Eterm key;
     int dir;
@@ -626,16 +672,13 @@ static int db_put_tree(DbTable *tbl, Eterm obj, int key_clash_fail)
 
     key = GETKEY(tb, tuple_val(obj));
 
-    reset_static_stack(tb);
+    reset_static_stack(stack_container);
 
     dstack[dpos++] = DIR_END;
     for (;;)
 	if (!*this) { /* Found our place */
 	    state = 1;
-	    if (erts_atomic_inc_read_nob(&tb->common.nitems) >= TREE_MAX_ELEMENTS) {
-		erts_atomic_dec_nob(&tb->common.nitems);
-		return DB_ERROR_SYSRES;
-	    }
+            INC_NITEMS(((DbTable*)tb));
 	    *this = new_dbterm(tb, obj);
 	    (*this)->balance = 0;
 	    (*this)->left = (*this)->right = NULL;
@@ -724,9 +767,15 @@ static int db_put_tree(DbTable *tbl, Eterm obj, int key_clash_fail)
     return DB_ERROR_NONE;
 }
 
-static int db_get_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+static int db_put_tree(DbTable *tbl, Eterm obj, int key_clash_fail)
 {
     DbTableTree *tb = &tbl->tree;
+    return db_put_tree_common(&tb->common, &tb->root, obj, key_clash_fail, tb);
+}
+
+int db_get_tree_common(Process *p, DbTableCommon *tb, TreeDbTerm *root, Eterm key,
+                       Eterm *ret, DbTableTree *stack_container)
+{
     Eterm copy;
     Eterm *hp, *hend;
     TreeDbTerm *this;
@@ -737,13 +786,13 @@ static int db_get_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
      * The list created around it is purely for interface conformance.
      */
     
-    this = find_node(tb,key);
+    this = find_node(tb,root,key,stack_container);
     if (this == NULL) {
 	*ret = NIL;
     } else {
 	hp = HAlloc(p, this->dbterm.size + 2);
 	hend = hp + this->dbterm.size + 2;
-	copy = db_copy_object_from_ets(&tb->common, &this->dbterm, &hp, &MSO(p));
+	copy = db_copy_object_from_ets(tb, &this->dbterm, &hp, &MSO(p));
 	*ret = CONS(hp, copy, NIL);
 	hp += 2;
 	HRelease(p,hend,hp);
@@ -751,18 +800,28 @@ static int db_get_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
     return DB_ERROR_NONE;
 }
 
-static int db_member_tree(DbTable *tbl, Eterm key, Eterm *ret)
+static int db_get_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
 {
     DbTableTree *tb = &tbl->tree;
+    return db_get_tree_common(p, &tb->common, tb->root, key, ret, tb);
+}
 
-    *ret = (find_node(tb,key) == NULL) ? am_false : am_true;
+int db_member_tree_common(DbTableCommon *tb, TreeDbTerm *root, Eterm key, Eterm *ret,
+                          DbTableTree *stack_container)
+{
+    *ret = (find_node(tb,root,key,stack_container) == NULL) ? am_false : am_true;
     return DB_ERROR_NONE;
 }
 
-static int db_get_element_tree(Process *p, DbTable *tbl,
-			       Eterm key, int ndex, Eterm *ret)
+static int db_member_tree(DbTable *tbl, Eterm key, Eterm *ret)
 {
     DbTableTree *tb = &tbl->tree;
+    return db_member_tree_common(&tb->common, tb->root, key, ret, tb);
+}
+
+int db_get_element_tree_common(Process *p, DbTableCommon *tb, TreeDbTerm *root, Eterm key,
+                               int ndex, Eterm *ret, DbTableTree *stack_container)
+{
     /*
      * Look the node up:
      */
@@ -776,54 +835,74 @@ static int db_get_element_tree(Process *p, DbTable *tbl,
      * around the element here either.
      */
     
-    this = find_node(tb,key);
+    this = find_node(tb,root,key,stack_container);
     if (this == NULL) {
 	return DB_ERROR_BADKEY;
     } else {
 	if (ndex > arityval(this->dbterm.tpl[0])) {
 	    return DB_ERROR_BADPARAM;
 	}
-	*ret = db_copy_element_from_ets(&tb->common, p, &this->dbterm, ndex, &hp, 0);
+	*ret = db_copy_element_from_ets(tb, p, &this->dbterm, ndex, &hp, 0);
     }
     return DB_ERROR_NONE;
 }
 
-static int db_erase_tree(DbTable *tbl, Eterm key, Eterm *ret)
+static int db_get_element_tree(Process *p, DbTable *tbl,
+			       Eterm key, int ndex, Eterm *ret)
 {
     DbTableTree *tb = &tbl->tree;
+    return db_get_element_tree_common(p, &tb->common, tb->root, key,
+                                      ndex, ret, tb);
+}
+
+int db_erase_tree_common(DbTable *tbl, TreeDbTerm **root, Eterm key, Eterm *ret,
+                         DbTreeStack *stack /* NULL if no static stack */)
+{
     TreeDbTerm *res;
 
     *ret = am_true;
 
-    if ((res = linkout_tree(tb, key)) != NULL) {
-	free_term(tb, res);
+    if ((res = linkout_tree(&tbl->common, root,key, stack)) != NULL) {
+	free_term(tbl, res);
     }
     return DB_ERROR_NONE;
 }
 
-static int db_erase_object_tree(DbTable *tbl, Eterm object, Eterm *ret)
+static int db_erase_tree(DbTable *tbl, Eterm key, Eterm *ret)
 {
     DbTableTree *tb = &tbl->tree;
+    return db_erase_tree_common(tbl, &tb->root, key, ret, &tb->static_stack);
+}
+
+int db_erase_object_tree_common(DbTable *tbl, TreeDbTerm **root, Eterm object,
+                                Eterm *ret, DbTableTree *stack_container)
+{
     TreeDbTerm *res;
 
     *ret = am_true;
 
-    if ((res = linkout_object_tree(tb, object)) != NULL) {
-	free_term(tb, res);
+    if ((res = linkout_object_tree(&tbl->common, root, object, stack_container)) != NULL) {
+	free_term(tbl, res);
     }
     return DB_ERROR_NONE;
 }
 
-
-static int db_slot_tree(Process *p, DbTable *tbl, 
-			Eterm slot_term, Eterm *ret)
+static int db_erase_object_tree(DbTable *tbl, Eterm object, Eterm *ret)
 {
     DbTableTree *tb = &tbl->tree;
+    return  db_erase_object_tree_common(tbl, &tb->root, object, ret, tb);
+}
+
+int db_slot_tree_common(Process *p, DbTable *tbl, TreeDbTerm *root,
+                        Eterm slot_term, Eterm *ret,
+                        DbTableTree *stack_container,
+                        CATreeRootIterator *iter)
+{
     Sint slot;
     TreeDbTerm *st;
     Eterm *hp, *hend;
     Eterm copy;
-
+    int is_EOT = 0;
     /*
      * The notion of a "slot" is not natural in a tree, but we try to
      * simulate it by giving the n'th node in the tree instead.
@@ -834,10 +913,10 @@ static int db_slot_tree(Process *p, DbTable *tbl,
 
     if (is_not_small(slot_term) ||
 	((slot = signed_val(slot_term)) < 0) ||
-	(slot > NITEMS(tb)))
+	(IS_CENTRALIZED_CTR(tbl) && slot > NITEMS_CENTRALIZED(tbl)))
 	return DB_ERROR_BADPARAM;
 
-    if (slot == NITEMS(tb)) {
+    if (IS_CENTRALIZED_CTR(tbl) && slot == NITEMS_CENTRALIZED(tbl)) {
 	*ret = am_EOT;
 	return DB_ERROR_NONE;
     }
@@ -847,20 +926,31 @@ static int db_slot_tree(Process *p, DbTable *tbl,
      * are counted from 1 and up.
      */
     ++slot;
-    st = slot_search(p, tb, slot); 
+    st = slot_search(p, root, slot, tbl, stack_container, iter, &is_EOT);
+    if (is_EOT) {
+        *ret = am_EOT;
+	return DB_ERROR_NONE;
+    }
     if (st == NULL) {
 	*ret = am_false;
 	return DB_ERROR_UNSPEC;
     }
     hp = HAlloc(p, st->dbterm.size + 2);
     hend = hp + st->dbterm.size + 2;
-    copy = db_copy_object_from_ets(&tb->common, &st->dbterm, &hp, &MSO(p));
+    copy = db_copy_object_from_ets(&tbl->common, &st->dbterm, &hp, &MSO(p));
     *ret = CONS(hp, copy, NIL);
     hp += 2;
     HRelease(p,hend,hp);
     return DB_ERROR_NONE;
 }
 
+static int db_slot_tree(Process *p, DbTable *tbl, 
+			Eterm slot_term, Eterm *ret)
+{
+    DbTableTree *tb = &tbl->tree;
+    return db_slot_tree_common(p, tbl, tb->root, slot_term, ret, tb, NULL);
+}
+
 
 
 static BIF_RETTYPE ets_select_reverse(BIF_ALIST_3)
@@ -926,19 +1016,14 @@ static BIF_RETTYPE bif_trap3(Export *bif,
 {
     BIF_TRAP3(bif, p, p1, p2, p3);
 }
-    
-/*
-** This is called either when the select bif traps or when ets:select/1 
-** is called. It does mostly the same as db_select_tree and may in either case
-** trap to itself again (via the ets:select/1 bif).
-** Note that this is common for db_select_tree and db_select_chunk_tree.
-*/
-static int db_select_continue_tree(Process *p, 
-				   DbTable *tbl,
-				   Eterm continuation,
-				   Eterm *ret)
+
+int db_select_continue_tree_common(Process *p, 
+                                   DbTableCommon *tb,
+                                   Eterm continuation,
+                                   Eterm *ret,
+                                   DbTableTree *stack_container,
+                                   CATreeRootIterator* iter)
 {
-    DbTableTree *tb = &tbl->tree;
     DbTreeStack* stack;
     struct select_context sc;
     unsigned sz;
@@ -951,7 +1036,6 @@ static int db_select_continue_tree(Process *p,
     Sint chunk_size;
     Sint reverse;
 
-
 #define RET_TO_BIF(Term, State) do { *ret = (Term); return State; } while(0);
 
     /* Decode continuation. We know it's a tuple but not the arity or 
@@ -980,28 +1064,37 @@ static int db_select_continue_tree(Process *p,
     sc.end_condition = NIL;
     sc.lastobj = NULL;
     sc.max = 1000;
-    sc.keypos = tb->common.keypos;
+    sc.keypos = tb->keypos;
     sc.chunk_size = chunk_size;
     reverse = unsigned_val(tptr[7]);
     sc.got = signed_val(tptr[8]);
 
-    stack = get_any_stack(tb);
-    if (chunk_size) {
-	if (reverse) {
-	    traverse_backwards(tb, stack, lastkey, &doit_select_chunk, &sc);
-	} else {
-	    traverse_forward(tb, stack, lastkey, &doit_select_chunk, &sc);
-	}
-    } else {
-	if (reverse) {
-	    traverse_forward(tb, stack, lastkey, &doit_select, &sc);
-	} else {
-	    traverse_backwards(tb, stack, lastkey, &doit_select, &sc);
-	}
+    if (iter) {
+        iter->next_route_key = lastkey;
+        sc.common.root = catree_find_nextprev_root(iter, !!reverse != !!chunk_size, NULL);
     }
-    release_stack(tb,stack);
+    else
+        sc.common.root = &((DbTableTree*)tb)->root;
+
+    if (sc.common.root) {
+        stack = get_any_stack((DbTable*)tb, stack_container);
+        if (chunk_size) {
+            if (reverse) {
+                traverse_backwards(tb, stack, lastkey, &doit_select_chunk, &sc.common, iter);
+            } else {
+                traverse_forward(tb, stack, lastkey, &doit_select_chunk, &sc.common, iter);
+            }
+        } else {
+            if (reverse) {
+                traverse_forward(tb, stack, lastkey, &doit_select, &sc.common, iter);
+            } else {
+                traverse_backwards(tb, stack, lastkey, &doit_select, &sc.common, iter);
+            }
+        }
+        release_stack((DbTable*)tb,stack_container,stack);
 
-    BUMP_REDS(p, 1000 - sc.max);
+        BUMP_REDS(p, 1000 - sc.max);
+    }
 
     if (sc.max > 0 || (chunk_size && sc.got == chunk_size)) {
 	if (chunk_size) {
@@ -1082,13 +1175,30 @@ static int db_select_continue_tree(Process *p,
 
 #undef RET_TO_BIF
 }
+    
+/*
+** This is called either when the select bif traps or when ets:select/1 
+** is called. It does mostly the same as db_select_tree and may in either case
+** trap to itself again (via the ets:select/1 bif).
+** Note that this is common for db_select_tree and db_select_chunk_tree.
+*/
+static int db_select_continue_tree(Process *p, 
+				   DbTable *tbl,
+				   Eterm continuation,
+				   Eterm *ret,
+                                   enum DbIterSafety* safety_p)
+{
+    DbTableTree *tb = &tbl->tree;
+    return db_select_continue_tree_common(p, &tb->common,
+                                          continuation, ret, tb, NULL);
+}
 
-
-static int db_select_tree(Process *p, DbTable *tbl, Eterm tid,
-			  Eterm pattern, int reverse, Eterm *ret)
+int db_select_tree_common(Process *p, DbTable *tb,
+                          Eterm tid, Eterm pattern, int reverse, Eterm *ret,
+                          DbTableTree *stack_container,
+                          CATreeRootIterator* iter)
 {
     /* Strategy: Traverse backwards to build resulting list from tail to head */
-    DbTableTree *tb = &tbl->tree;
     DbTreeStack* stack;
     struct select_context sc;
     struct mp_info mpi;
@@ -1121,42 +1231,62 @@ static int db_select_tree(Process *p, DbTable *tbl, Eterm tid,
     sc.got = 0;
     sc.chunk_size = 0;
 
-    if ((errcode = analyze_pattern(tb, pattern, NULL, &mpi)) != DB_ERROR_NONE) {
+    if ((errcode = analyze_pattern(&tb->common, pattern, NULL, &mpi)) != DB_ERROR_NONE) {
 	RET_TO_BIF(NIL,errcode);
     }
 
-    if (!mpi.something_can_match) {
+    if (mpi.key_boundness == MS_KEY_IMPOSSIBLE) {
 	RET_TO_BIF(NIL,DB_ERROR_NONE);  
 	/* can't possibly match anything */
     }
 
     sc.mp = mpi.mp;
 
-    if (!mpi.got_partial && mpi.some_limitation && 
-	CMP_EQ(mpi.least,mpi.most)) {
-	doit_select(tb,*(mpi.save_term),&sc,0 /* direction doesn't matter */);
+    if (mpi.key_boundness == MS_KEY_BOUND) {
+        ASSERT(CMP_EQ(mpi.least, mpi.most));
+        if (iter)
+            sc.common.root = catree_find_root(mpi.least, iter);
+        else
+            sc.common.root = &tb->tree.root;
+        this = find_node(&tb->common, *sc.common.root, mpi.least, NULL);
+        if (this)
+            doit_select(&tb->common, this, &sc.common, 0 /* direction doesn't matter */);
 	RET_TO_BIF(sc.accum,DB_ERROR_NONE);
     }
 
-    stack = get_any_stack(tb);
+    stack = get_any_stack((DbTable*)tb,stack_container);
     if (reverse) {
-	if (mpi.some_limitation) {
-	    if ((this = find_prev_from_pb_key(tb, stack, mpi.least)) != NULL) {
+	if (mpi.key_boundness == MS_KEY_PARTIALLY_BOUND) {
+            this = find_prev_from_pb_key(tb, &sc.common.root, stack, mpi.least, iter);
+	    if (this)
 		lastkey = GETKEY(tb, this->dbterm.tpl);
-	    }
 	    sc.end_condition = mpi.most;
 	}
-	traverse_forward(tb, stack, lastkey, &doit_select, &sc);
+        else {
+            ASSERT(mpi.key_boundness == MS_KEY_UNBOUND);
+            if (iter)
+                sc.common.root = catree_find_first_root(iter);
+            else
+                sc.common.root = &tb->tree.root;
+        }
+	traverse_forward(&tb->common, stack, lastkey, &doit_select, &sc.common, iter);
     } else {
-	if (mpi.some_limitation) {
-	    if ((this = find_next_from_pb_key(tb, stack, mpi.most)) != NULL) {
-		lastkey = GETKEY(tb, this->dbterm.tpl);
-	    }
+	if (mpi.key_boundness == MS_KEY_PARTIALLY_BOUND) {
+            this = find_next_from_pb_key(tb, &sc.common.root, stack, mpi.most, iter);
+	    if (this)
+                lastkey = GETKEY(tb, this->dbterm.tpl);
 	    sc.end_condition = mpi.least;
 	}
-	traverse_backwards(tb, stack, lastkey, &doit_select, &sc);
+        else {
+            ASSERT(mpi.key_boundness == MS_KEY_UNBOUND);
+            if (iter)
+                sc.common.root = catree_find_last_root(iter);
+            else
+                sc.common.root = &tb->tree.root;
+        }
+	traverse_backwards(&tb->common, stack, lastkey, &doit_select, &sc.common, iter);
     }
-    release_stack(tb,stack);
+    release_stack((DbTable*)tb,stack_container,stack);
 #ifdef HARDDEBUG
 	erts_fprintf(stderr,"Least: %T\n", mpi.least);
 	erts_fprintf(stderr,"Most: %T\n", mpi.most);
@@ -1192,16 +1322,21 @@ static int db_select_tree(Process *p, DbTable *tbl, Eterm tid,
 
 }
 
-    
-/*
-** This is called either when the select_count bif traps.
-*/
-static int db_select_count_continue_tree(Process *p, 
-					 DbTable *tbl,
-					 Eterm continuation,
-					 Eterm *ret)
+static int db_select_tree(Process *p, DbTable *tbl, Eterm tid,
+			  Eterm pattern, int reverse, Eterm *ret,
+                          enum DbIterSafety safety)
+{
+    return db_select_tree_common(p, tbl, tid,
+                                 pattern, reverse, ret, &tbl->tree, NULL);
+}
+
+int db_select_count_continue_tree_common(Process *p, 
+                                         DbTable *tb,
+                                         Eterm continuation,
+                                         Eterm *ret,
+                                         DbTableTree *stack_container,
+                                         CATreeRootIterator* iter)
 {
-    DbTableTree *tb = &tbl->tree;
     DbTreeStack* stack;
     struct select_count_context sc;
     unsigned sz;
@@ -1213,7 +1348,6 @@ static int db_select_count_continue_tree(Process *p,
     Eterm *tptr;
     Eterm egot;
 
-
 #define RET_TO_BIF(Term, State) do { *ret = (Term); return State; } while(0);
 
     /* Decode continuation. We know it's a tuple and everything else as
@@ -1245,11 +1379,21 @@ static int db_select_count_continue_tree(Process *p,
 	sc.got = unsigned_val(tptr[5]);
     }
 
-    stack = get_any_stack(tb);
-    traverse_backwards(tb, stack, lastkey, &doit_select_count, &sc);
-    release_stack(tb,stack);
+    if (iter) {
+        iter->next_route_key = lastkey;
+        sc.common.root = catree_find_prev_root(iter, NULL);
+    }
+    else {
+        sc.common.root = &tb->tree.root;
+    }
+
+    if (sc.common.root) {
+        stack = get_any_stack(tb, stack_container);
+        traverse_backwards(&tb->common, stack, lastkey, &doit_select_count, &sc.common, iter);
+        release_stack(tb,stack_container,stack);
 
-    BUMP_REDS(p, 1000 - sc.max);
+        BUMP_REDS(p, 1000 - sc.max);
+    }
 
     if (sc.max > 0) {
 	RET_TO_BIF(erts_make_integer(sc.got,p), DB_ERROR_NONE);
@@ -1285,11 +1429,26 @@ static int db_select_count_continue_tree(Process *p,
 #undef RET_TO_BIF
 }
 
-
-static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
-				Eterm pattern, Eterm *ret)
+/*
+** This is called either when the select_count bif traps.
+*/
+static int db_select_count_continue_tree(Process *p, 
+                                         DbTable *tbl,
+                                         Eterm continuation,
+                                         Eterm *ret,
+                                         enum DbIterSafety* safety_p)
 {
     DbTableTree *tb = &tbl->tree;
+    return db_select_count_continue_tree_common(p, tbl,
+                                                continuation, ret, tb, NULL);
+}
+
+
+int db_select_count_tree_common(Process *p, DbTable *tb,
+                                Eterm tid, Eterm pattern, Eterm *ret,
+                                DbTableTree *stack_container,
+                                CATreeRootIterator* iter)
+{
     DbTreeStack* stack;
     struct select_count_context sc;
     struct mp_info mpi;
@@ -1303,7 +1462,6 @@ static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
     Eterm egot;
     Eterm mpb;
 
-
 #define RET_TO_BIF(Term,RetVal) do { 	       	\
 	if (mpi.mp != NULL) {			\
 	    erts_bin_free(mpi.mp);       	\
@@ -1321,33 +1479,46 @@ static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
     sc.keypos = tb->common.keypos;
     sc.got = 0;
 
-    if ((errcode = analyze_pattern(tb, pattern, NULL, &mpi)) != DB_ERROR_NONE) {
+    if ((errcode = analyze_pattern(&tb->common, pattern, NULL, &mpi)) != DB_ERROR_NONE) {
 	RET_TO_BIF(NIL,errcode);
     }
 
-    if (!mpi.something_can_match) {
+    if (mpi.key_boundness == MS_KEY_IMPOSSIBLE) {
 	RET_TO_BIF(make_small(0),DB_ERROR_NONE);  
 	/* can't possibly match anything */
     }
 
     sc.mp = mpi.mp;
 
-    if (!mpi.got_partial && mpi.some_limitation && 
-	CMP_EQ(mpi.least,mpi.most)) {
-	doit_select_count(tb,*(mpi.save_term),&sc,0 /* dummy */);
+    if (mpi.key_boundness == MS_KEY_BOUND) {
+        ASSERT(CMP_EQ(mpi.least, mpi.most));
+        if (iter)
+            sc.common.root = catree_find_root(mpi.least, iter);
+        else
+            sc.common.root = &((DbTable*)tb)->tree.root;
+        this =  find_node(&tb->common, *sc.common.root, mpi.least, NULL);
+        if (this)
+            doit_select_count(&tb->common, this, &sc.common, 0 /* dummy */);
 	RET_TO_BIF(erts_make_integer(sc.got,p),DB_ERROR_NONE);
     }
 
-    stack = get_any_stack(tb);
-    if (mpi.some_limitation) {
-	if ((this = find_next_from_pb_key(tb, stack, mpi.most)) != NULL) {
-	    lastkey = GETKEY(tb, this->dbterm.tpl);
-	}
+    stack = get_any_stack((DbTable*)tb, stack_container);
+    if (mpi.key_boundness == MS_KEY_PARTIALLY_BOUND) {
+        this = find_next_from_pb_key(tb, &sc.common.root, stack, mpi.most, iter);
+	if (this)
+            lastkey = GETKEY(tb, this->dbterm.tpl);
 	sc.end_condition = mpi.least;
     }
+    else {
+        ASSERT(mpi.key_boundness == MS_KEY_UNBOUND);
+        if (iter)
+            sc.common.root = catree_find_last_root(iter);
+        else
+            sc.common.root = &tb->tree.root;
+    }
     
-    traverse_backwards(tb, stack, lastkey, &doit_select_count, &sc);
-    release_stack(tb,stack);
+    traverse_backwards(&tb->common, stack, lastkey, &doit_select_count, &sc.common, iter);
+    release_stack((DbTable*)tb,stack_container,stack);
     BUMP_REDS(p, 1000 - sc.max);
     if (sc.max > 0) {
 	RET_TO_BIF(erts_make_integer(sc.got,p),DB_ERROR_NONE);
@@ -1383,12 +1554,22 @@ static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
 
 }
 
-static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
-				Eterm pattern, Sint chunk_size,
-				int reverse,
-				Eterm *ret)
+static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
+                                Eterm pattern, Eterm *ret,
+                                enum DbIterSafety safety)
 {
     DbTableTree *tb = &tbl->tree;
+    return db_select_count_tree_common(p, tbl,
+                                       tid, pattern, ret, tb, NULL);
+}
+
+
+int db_select_chunk_tree_common(Process *p, DbTable *tb,
+                                Eterm tid, Eterm pattern, Sint chunk_size,
+                                int reverse, Eterm *ret,
+                                DbTableTree *stack_container,
+                                CATreeRootIterator* iter)
+{
     DbTreeStack* stack;
     struct select_context sc;
     struct mp_info mpi;
@@ -1401,7 +1582,6 @@ static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
     int errcode;
     Eterm mpb;
 
-
 #define RET_TO_BIF(Term,RetVal) do { 		\
 	if (mpi.mp != NULL) {			\
 	    erts_bin_free(mpi.mp);		\
@@ -1421,20 +1601,26 @@ static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
     sc.got = 0;
     sc.chunk_size = chunk_size;
 
-    if ((errcode = analyze_pattern(tb, pattern, NULL, &mpi)) != DB_ERROR_NONE) {
+    if ((errcode = analyze_pattern(&tb->common, pattern, NULL, &mpi)) != DB_ERROR_NONE) {
 	RET_TO_BIF(NIL,errcode);
     }
 
-    if (!mpi.something_can_match) {
+    if (mpi.key_boundness == MS_KEY_IMPOSSIBLE) {
 	RET_TO_BIF(am_EOT,DB_ERROR_NONE);
 	/* can't possibly match anything */
     }
 
     sc.mp = mpi.mp;
 
-    if (!mpi.got_partial && mpi.some_limitation && 
-	CMP_EQ(mpi.least,mpi.most)) {
-	doit_select(tb,*(mpi.save_term),&sc, 0 /* direction doesn't matter */);
+    if (mpi.key_boundness == MS_KEY_BOUND) {
+        ASSERT(CMP_EQ(mpi.least, mpi.most));
+        if (iter)
+            sc.common.root = catree_find_root(mpi.least, iter);
+        else
+            sc.common.root = &tb->tree.root;
+        this =  find_node(&tb->common, *sc.common.root, mpi.least, NULL);
+        if (this)
+            doit_select(&tb->common, this, &sc.common, 0 /* direction doesn't matter */);
 	if (sc.accum != NIL) {
 	    hp=HAlloc(p, 3);
 	    RET_TO_BIF(TUPLE2(hp,sc.accum,am_EOT),DB_ERROR_NONE);
@@ -1443,25 +1629,39 @@ static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
 	}
     }
 
-    stack = get_any_stack(tb);
+    stack = get_any_stack((DbTable*)tb,stack_container);
     if (reverse) {
-	if (mpi.some_limitation) {
-	    if ((this = find_next_from_pb_key(tb, stack, mpi.most)) != NULL) {
-		lastkey = GETKEY(tb, this->dbterm.tpl);
-	    }
+	if (mpi.key_boundness == MS_KEY_PARTIALLY_BOUND) {
+            this = find_next_from_pb_key(tb, &sc.common.root, stack, mpi.most, iter);
+	    if (this)
+                lastkey = GETKEY(tb, this->dbterm.tpl);
 	    sc.end_condition = mpi.least;
 	}
-	traverse_backwards(tb, stack, lastkey, &doit_select_chunk, &sc);
+        else {
+            ASSERT(mpi.key_boundness == MS_KEY_UNBOUND);
+            if (iter)
+                sc.common.root = catree_find_last_root(iter);
+            else
+                sc.common.root = &tb->tree.root;
+        }
+	traverse_backwards(&tb->common, stack, lastkey, &doit_select_chunk, &sc.common, iter);
     } else {
-	if (mpi.some_limitation) {
-	    if ((this = find_prev_from_pb_key(tb, stack, mpi.least)) != NULL) {
-		lastkey = GETKEY(tb, this->dbterm.tpl);
-	    }
+	if (mpi.key_boundness == MS_KEY_PARTIALLY_BOUND) {
+            this = find_prev_from_pb_key(tb, &sc.common.root, stack, mpi.least, iter);
+	    if (this)
+                lastkey = GETKEY(tb, this->dbterm.tpl);
 	    sc.end_condition = mpi.most;
 	}
-	traverse_forward(tb, stack, lastkey, &doit_select_chunk, &sc);
+        else {
+            ASSERT(mpi.key_boundness == MS_KEY_UNBOUND);
+            if (iter)
+                sc.common.root = catree_find_first_root(iter);
+            else
+                sc.common.root = &tb->tree.root;
+        }
+	traverse_forward(&tb->common, stack, lastkey, &doit_select_chunk, &sc.common, iter);
     }
-    release_stack(tb,stack);
+    release_stack((DbTable*)tb,stack_container,stack);
 
     BUMP_REDS(p, 1000 - sc.max);
     if (sc.max > 0 || sc.got == chunk_size) {
@@ -1530,15 +1730,25 @@ static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
 
 }
 
-/*
-** This is called when select_delete traps
-*/
-static int db_select_delete_continue_tree(Process *p, 
-					  DbTable *tbl,
-					  Eterm continuation,
-					  Eterm *ret)
+static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
+                                Eterm pattern, Sint chunk_size,
+                                int reverse,
+                                Eterm *ret, enum DbIterSafety safety)
 {
     DbTableTree *tb = &tbl->tree;
+    return db_select_chunk_tree_common(p, tbl,
+                                       tid, pattern, chunk_size,
+                                       reverse, ret, tb, NULL);
+}
+
+
+int db_select_delete_continue_tree_common(Process *p,
+                                          DbTable *tbl,
+                                          Eterm continuation,
+                                          Eterm *ret,
+                                          DbTreeStack* stack,
+                                          CATreeRootIterator* iter)
+{
     struct select_delete_context sc;
     unsigned sz;
     Eterm *hp; 
@@ -1549,10 +1759,9 @@ static int db_select_delete_continue_tree(Process *p,
     Eterm *tptr;
     Eterm eaccsum;
 
-
 #define RET_TO_BIF(Term, State) do { 		\
 	if (sc.erase_lastterm) {		\
-	    free_term(tb, sc.lastterm);		\
+	    free_term(tbl, sc.lastterm);		\
 	}					\
 	*ret = (Term); 				\
 	return State; 				\
@@ -1571,7 +1780,8 @@ static int db_select_delete_continue_tree(Process *p,
 
     mp = erts_db_get_match_prog_binary_unchecked(tptr[4]);
     sc.p = p;
-    sc.tb = tb;
+    sc.tb = &tbl->common;
+    sc.stack = stack;
     if (is_big(tptr[5])) {
 	sc.accum = big_to_uint32(tptr[5]);
     } else {
@@ -1580,17 +1790,26 @@ static int db_select_delete_continue_tree(Process *p,
     sc.mp = mp;
     sc.end_condition = NIL;
     sc.max = 1000;
-    sc.keypos = tb->common.keypos;
+    sc.keypos = tbl->common.keypos;
 
-    ASSERT(!erts_atomic_read_nob(&tb->is_stack_busy));
-    traverse_backwards(tb, &tb->static_stack, lastkey, &doit_select_delete, &sc);
+    if (iter) {
+        iter->next_route_key = lastkey;
+        sc.common.root = catree_find_prev_root(iter, NULL);
+    }
+    else {
+        sc.common.root = &tbl->tree.root;
+    }
 
-    BUMP_REDS(p, 1000 - sc.max);
+    if (sc.common.root) {
+        traverse_backwards(&tbl->common, stack, lastkey, &doit_select_delete, &sc.common, iter);
+
+        BUMP_REDS(p, 1000 - sc.max);
+    }
 
     if (sc.max > 0) {
 	RET_TO_BIF(erts_make_integer(sc.accum, p), DB_ERROR_NONE);
     }	
-    key = GETKEY(tb, (sc.lastterm)->dbterm.tpl);
+    key = GETKEY(&tbl->common, (sc.lastterm)->dbterm.tpl);
     if (end_condition != NIL && 
 	cmp_partly_bound(end_condition,key) > 0) { /* done anyway */
 	RET_TO_BIF(erts_make_integer(sc.accum,p),DB_ERROR_NONE);
@@ -1620,10 +1839,24 @@ static int db_select_delete_continue_tree(Process *p,
 #undef RET_TO_BIF
 }
 
-static int db_select_delete_tree(Process *p, DbTable *tbl, Eterm tid,
-				 Eterm pattern, Eterm *ret)
+static int db_select_delete_continue_tree(Process *p, 
+					  DbTable *tbl,
+					  Eterm continuation,
+					  Eterm *ret,
+                                          enum DbIterSafety* safety_p)
 {
     DbTableTree *tb = &tbl->tree;
+    ASSERT(!erts_atomic_read_nob(&tb->is_stack_busy));
+    return db_select_delete_continue_tree_common(p, tbl, continuation, ret,
+                                                 &tb->static_stack, NULL);
+}
+
+int db_select_delete_tree_common(Process *p, DbTable *tbl,
+                                 Eterm tid, Eterm pattern,
+                                 Eterm *ret,
+                                 DbTreeStack* stack,
+                                 CATreeRootIterator* iter)
+{
     struct select_delete_context sc;
     struct mp_info mpi;
     Eterm lastkey = THE_NON_VALUE;
@@ -1641,7 +1874,7 @@ static int db_select_delete_tree(Process *p, DbTable *tbl, Eterm tid,
 	    erts_bin_free(mpi.mp);       	\
 	}					\
 	if (sc.erase_lastterm) {                \
-	    free_term(tb, sc.lastterm);         \
+	    free_term(tbl, sc.lastterm);         \
 	}                                       \
 	*ret = (Term); 				\
 	return RetVal; 			        \
@@ -1655,42 +1888,57 @@ static int db_select_delete_tree(Process *p, DbTable *tbl, Eterm tid,
     sc.p = p;
     sc.max = 1000; 
     sc.end_condition = NIL;
-    sc.keypos = tb->common.keypos;
-    sc.tb = tb;
+    sc.keypos = tbl->common.keypos;
+    sc.tb = &tbl->common;
+    sc.stack = stack;
     
-    if ((errcode = analyze_pattern(tb, pattern, NULL, &mpi)) != DB_ERROR_NONE) {
+    if ((errcode = analyze_pattern(&tbl->common, pattern, NULL, &mpi)) != DB_ERROR_NONE) {
 	RET_TO_BIF(0,errcode);
     }
 
-    if (!mpi.something_can_match) {
+    if (mpi.key_boundness == MS_KEY_IMPOSSIBLE) {
 	RET_TO_BIF(make_small(0),DB_ERROR_NONE);  
 	/* can't possibly match anything */
     }
 
     sc.mp = mpi.mp;
 
-    if (!mpi.got_partial && mpi.some_limitation && 
-	CMP_EQ(mpi.least,mpi.most)) {
-	doit_select_delete(tb,*(mpi.save_term),&sc, 0 /* direction doesn't
+    if (mpi.key_boundness == MS_KEY_BOUND) {
+        ASSERT(CMP_EQ(mpi.least, mpi.most));
+        if (iter)
+            sc.common.root = catree_find_root(mpi.least, iter);
+        else
+            sc.common.root = &tbl->tree.root;
+        this =  find_node(&tbl->common, *sc.common.root, mpi.least, NULL);
+        if (this)
+            doit_select_delete(&tbl->common, this, &sc.common, 0 /* direction doesn't
 						      matter */);
 	RET_TO_BIF(erts_make_integer(sc.accum,p),DB_ERROR_NONE);
     }
 
-    if (mpi.some_limitation) {
-	if ((this = find_next_from_pb_key(tb, &tb->static_stack, mpi.most)) != NULL) {
-	    lastkey = GETKEY(tb, this->dbterm.tpl);
-	}
+    if (mpi.key_boundness == MS_KEY_PARTIALLY_BOUND) {
+        this = find_next_from_pb_key(tbl, &sc.common.root, stack, mpi.most, iter);
+        if (this)
+            lastkey = GETKEY(&tbl->common, this->dbterm.tpl);
 	sc.end_condition = mpi.least;
     }
+    else {
+        ASSERT(mpi.key_boundness == MS_KEY_UNBOUND);
+        if (iter)
+            sc.common.root = catree_find_last_root(iter);
+        else
+            sc.common.root = &tbl->tree.root;
+    }
 
-    traverse_backwards(tb, &tb->static_stack, lastkey, &doit_select_delete, &sc);
+    traverse_backwards(&tbl->common, stack, lastkey,
+                       &doit_select_delete, &sc.common, iter);
     BUMP_REDS(p, 1000 - sc.max);
 
     if (sc.max > 0) {
 	RET_TO_BIF(erts_make_integer(sc.accum,p), DB_ERROR_NONE);
     }
 
-    key = GETKEY(tb, (sc.lastterm)->dbterm.tpl);
+    key = GETKEY(&tbl->common, (sc.lastterm)->dbterm.tpl);
     sz = size_object(key);
     if (IS_USMALL(0, sc.accum)) {
 	hp = HAlloc(p, sz + ERTS_MAGIC_REF_THING_SIZE + 6);
@@ -1714,7 +1962,7 @@ static int db_select_delete_tree(Process *p, DbTable *tbl, Eterm tid,
 
     /* Don't free mpi.mp, so don't use macro */
     if (sc.erase_lastterm) {
-	free_term(tb, sc.lastterm);
+	free_term(tbl, sc.lastterm);
     }
     *ret = bif_trap1(&ets_select_delete_continue_exp, p, continuation); 
     return DB_ERROR_NONE;
@@ -1723,12 +1971,22 @@ static int db_select_delete_tree(Process *p, DbTable *tbl, Eterm tid,
 
 }
 
-static int db_select_replace_continue_tree(Process *p,
+static int db_select_delete_tree(Process *p, DbTable *tbl, Eterm tid,
+				 Eterm pattern, Eterm *ret,
+                                 enum DbIterSafety safety)
+{
+    DbTableTree *tb = &tbl->tree;
+    return db_select_delete_tree_common(p, tbl, tid, pattern, ret,
+                                        &tb->static_stack, NULL);
+}
+
+int db_select_replace_continue_tree_common(Process *p,
                                            DbTable *tbl,
                                            Eterm continuation,
-                                           Eterm *ret)
+                                           Eterm *ret,
+                                           DbTableTree *stack_container,
+                                           CATreeRootIterator* iter)
 {
-    DbTableTree *tb = &tbl->tree;
     DbTreeStack* stack;
     struct select_replace_context sc;
     unsigned sz;
@@ -1764,7 +2022,7 @@ static int db_select_replace_continue_tree(Process *p,
     sc.end_condition = NIL;
     sc.lastobj = NULL;
     sc.max = 1000;
-    sc.keypos = tb->common.keypos;
+    sc.keypos = tbl->common.keypos;
     if (is_big(tptr[5])) {
         sc.replaced = big_to_uint32(tptr[5]);
     } else {
@@ -1772,9 +2030,18 @@ static int db_select_replace_continue_tree(Process *p,
     }
     prev_replaced = sc.replaced;
 
-    stack = get_any_stack(tb);
-    traverse_update_backwards(tb, stack, lastkey, &doit_select_replace, &sc);
-    release_stack(tb,stack);
+    if (iter) {
+        iter->next_route_key = lastkey;
+        sc.common.root = catree_find_prev_root(iter, NULL);
+    }
+    else {
+        sc.common.root = &tbl->tree.root;
+    }
+
+    stack = get_any_stack(tbl, stack_container);
+    traverse_update_backwards(&tbl->common, stack, lastkey, &doit_select_replace,
+                              &sc.common, iter);
+    release_stack(tbl, stack_container,stack);
 
     // the more objects we've replaced, the more reductions we've consumed
     BUMP_REDS(p, MIN(2000, (1000 - sc.max) + (sc.replaced - prev_replaced)));
@@ -1782,7 +2049,7 @@ static int db_select_replace_continue_tree(Process *p,
     if (sc.max > 0) {
         RET_TO_BIF(erts_make_integer(sc.replaced,p), DB_ERROR_NONE);
     }
-    key = GETKEY(tb, sc.lastobj);
+    key = GETKEY(tbl, sc.lastobj);
     if (end_condition != NIL &&
             (cmp_partly_bound(end_condition,key) > 0)) {
         /* done anyway */
@@ -1813,10 +2080,21 @@ static int db_select_replace_continue_tree(Process *p,
 #undef RET_TO_BIF
 }
 
-static int db_select_replace_tree(Process *p, DbTable *tbl, Eterm tid,
-                                  Eterm pattern, Eterm *ret)
+static int db_select_replace_continue_tree(Process *p,
+                                           DbTable *tbl,
+                                           Eterm continuation,
+                                           Eterm *ret,
+                                           enum DbIterSafety* safety_p)
+{
+    return db_select_replace_continue_tree_common(p, tbl, continuation, ret,
+                                                  &tbl->tree, NULL);
+}
+
+int db_select_replace_tree_common(Process *p, DbTable *tbl,
+                                  Eterm tid, Eterm pattern, Eterm *ret,
+                                  DbTableTree *stack_container,
+                                  CATreeRootIterator* iter)
 {
-    DbTableTree *tb = &tbl->tree;
     DbTreeStack* stack;
     struct select_replace_context sc;
     struct mp_info mpi;
@@ -1843,48 +2121,64 @@ static int db_select_replace_tree(Process *p, DbTable *tbl, Eterm tid,
 
     sc.lastobj = NULL;
     sc.p = p;
-    sc.tb = tb;
+    sc.tb = &tbl->common;
     sc.max = 1000;
     sc.end_condition = NIL;
-    sc.keypos = tb->common.keypos;
+    sc.keypos = tbl->common.keypos;
     sc.replaced = 0;
 
-    if ((errcode = analyze_pattern(tb, pattern, db_match_keeps_key, &mpi)) != DB_ERROR_NONE) {
+    if ((errcode = analyze_pattern(&tbl->common, pattern, db_match_keeps_key, &mpi)) != DB_ERROR_NONE) {
         RET_TO_BIF(NIL,errcode);
     }
 
-    if (!mpi.something_can_match) {
+    if (mpi.key_boundness == MS_KEY_IMPOSSIBLE) {
         RET_TO_BIF(make_small(0),DB_ERROR_NONE);
         /* can't possibly match anything */
     }
 
     sc.mp = mpi.mp;
 
-    if (!mpi.got_partial && mpi.some_limitation &&
-            CMP_EQ(mpi.least,mpi.most)) {
-        doit_select_replace(tb,mpi.save_term,&sc,0 /* dummy */);
-        reset_static_stack(tb); /* may refer replaced term */
+    if (mpi.key_boundness == MS_KEY_BOUND) {
+        TreeDbTerm** pp;
+        ASSERT(CMP_EQ(mpi.least, mpi.most));
+        if (iter)
+            sc.common.root = catree_find_root(mpi.least, iter);
+        else
+            sc.common.root = &tbl->tree.root;
+        pp = find_node2(&tbl->common, sc.common.root, mpi.least);
+        if (pp) {
+            doit_select_replace(&tbl->common, pp, &sc.common, 0 /* dummy */);
+            reset_static_stack(stack_container); /* may refer replaced term */
+        }
         RET_TO_BIF(erts_make_integer(sc.replaced,p),DB_ERROR_NONE);
     }
 
-    stack = get_any_stack(tb);
+    stack = get_any_stack(tbl,stack_container);
 
-    if (mpi.some_limitation) {
-        if ((this = find_next_from_pb_key(tb, stack, mpi.most)) != NULL) {
-            lastkey = GETKEY(tb, this->dbterm.tpl);
-        }
+    if (mpi.key_boundness == MS_KEY_PARTIALLY_BOUND) {
+        this = find_next_from_pb_key(tbl, &sc.common.root, stack, mpi.most, iter);
+        if (this)
+            lastkey = GETKEY(tbl, this->dbterm.tpl);
         sc.end_condition = mpi.least;
     }
+    else {
+        ASSERT(mpi.key_boundness == MS_KEY_UNBOUND);
+        if (iter)
+            sc.common.root = catree_find_last_root(iter);
+        else
+            sc.common.root = &tbl->tree.root;
+    }
 
-    traverse_update_backwards(tb, stack, lastkey, &doit_select_replace, &sc);
-    release_stack(tb,stack);
+    traverse_update_backwards(&tbl->common, stack, lastkey, &doit_select_replace,
+                              &sc.common, iter);
+    release_stack(tbl,stack_container,stack);
     // the more objects we've replaced, the more reductions we've consumed
     BUMP_REDS(p, MIN(2000, (1000 - sc.max) + sc.replaced));
     if (sc.max > 0) {
         RET_TO_BIF(erts_make_integer(sc.replaced,p),DB_ERROR_NONE);
     }
 
-    key = GETKEY(tb, sc.lastobj);
+    key = GETKEY(tbl, sc.lastobj);
     sz = size_object(key);
     if (IS_USMALL(0, sc.replaced)) {
         hp = HAlloc(p, sz + ERTS_MAGIC_REF_THING_SIZE + 6);
@@ -1914,52 +2208,74 @@ static int db_select_replace_tree(Process *p, DbTable *tbl, Eterm tid,
 
 }
 
-static int db_take_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+static int db_select_replace_tree(Process *p, DbTable *tbl, Eterm tid,
+                                  Eterm pattern, Eterm *ret,
+                                  enum DbIterSafety safety)
+{
+    return db_select_replace_tree_common(p, tbl, tid, pattern, ret,
+                                         &tbl->tree, NULL);
+}
+
+int db_take_tree_common(Process *p, DbTable *tbl, TreeDbTerm **root,
+                        Eterm key, Eterm *ret,
+                        DbTreeStack *stack /* NULL if no static stack */)
 {
-    DbTableTree *tb = &tbl->tree;
     TreeDbTerm *this;
 
     *ret = NIL;
-    this = linkout_tree(tb, key);
+    this = linkout_tree(&tbl->common, root, key, stack);
     if (this) {
         Eterm copy, *hp, *hend;
 
         hp = HAlloc(p, this->dbterm.size + 2);
         hend = hp + this->dbterm.size + 2;
-        copy = db_copy_object_from_ets(&tb->common,
+        copy = db_copy_object_from_ets(&tbl->common,
                                        &this->dbterm, &hp, &MSO(p));
         *ret = CONS(hp, copy, NIL);
         hp += 2;
         HRelease(p, hend, hp);
-        free_term(tb, this);
+        free_term(tbl, this);
     }
     return DB_ERROR_NONE;
 }
 
+static int db_take_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
+{
+    DbTableTree *tb = &tbl->tree;
+    return db_take_tree_common(p, tbl, &tb->root,
+                               key, ret, &tb->static_stack);
+}
+
 /*
 ** Other interface routines (not directly coupled to one bif)
 */
 
-
-/* Display tree contents (for dump) */
-static void db_print_tree(fmtfn_t to, void *to_arg,
-			  int show,
-			  DbTable *tbl)
+void db_print_tree_common(fmtfn_t to, void *to_arg,
+                          int show, TreeDbTerm *root, DbTable *tbl)
 {
-    DbTableTree *tb = &tbl->tree;
 #ifdef TREE_DEBUG
     if (show)
 	erts_print(to, to_arg, "\nTree data dump:\n"
 		   "------------------------------------------------\n");
-    do_dump_tree2(&tbl->tree, to, to_arg, show, tb->root, 0);
+    do_dump_tree2(&tbl->common, to, to_arg, show, root, 0);
     if (show)
 	erts_print(to, to_arg, "\n"
 		   "------------------------------------------------\n");
 #else
-    erts_print(to, to_arg, "Ordered set (AVL tree), Elements: %d\n", NITEMS(tb));
+    erts_print(to, to_arg, "Ordered set (AVL tree), Elements: %d\n",
+               erts_flxctr_read_approx(&tbl->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID));
 #endif
 }
 
+/* Display tree contents (for dump) */
+static void db_print_tree(fmtfn_t to, void *to_arg,
+			  int show,
+			  DbTable *tbl)
+{
+    DbTableTree *tb = &tbl->tree;
+    db_print_tree_common(to, to_arg, show, tb->root, tbl);
+}
+
 /* release all memory occupied by a single table */
 static int db_free_empty_table_tree(DbTable *tbl)
 {
@@ -1984,31 +2300,57 @@ static SWord db_free_table_continue_tree(DbTable *tbl, SWord reds)
 		     (DbTable *) tb,
 		     (void *) tb->static_stack.array,
 		     sizeof(TreeDbTerm *) * STACK_NEED);
-	ASSERT(erts_atomic_read_nob(&tb->common.memory_size)
-	       == sizeof(DbTable));
+	ASSERT(erts_flxctr_is_snapshot_ongoing(&tb->common.counters) ||
+               ((APPROX_MEM_CONSUMED(tb)
+                 == sizeof(DbTable)) ||
+                (APPROX_MEM_CONSUMED(tb)
+                 == (sizeof(DbTable) + sizeof(DbFixation)))));
     }
     return reds;
 }
 
-static SWord db_delete_all_objects_tree(Process* p, DbTable* tbl, SWord reds)
+static SWord db_delete_all_objects_tree(Process* p,
+                                        DbTable* tbl,
+                                        SWord reds,
+                                        Eterm* nitems_holder_wb)
 {
+    if (nitems_holder_wb != NULL) {
+        Uint nr_of_items =
+            erts_flxctr_read_centralized(&tbl->common.counters,
+                                         ERTS_DB_TABLE_NITEMS_COUNTER_ID);
+        *nitems_holder_wb = erts_make_integer(nr_of_items, p);
+    }
     reds = db_free_table_continue_tree(tbl, reds);
     if (reds < 0)
         return reds;
     db_create_tree(p, tbl);
-    erts_atomic_set_nob(&tbl->tree.common.nitems, 0);
+    RESET_NITEMS(tbl);
     return reds;
 }
 
+static Eterm db_delete_all_objects_get_nitems_from_holder_tree(Process* p,
+                                                               Eterm holder)
+{
+    (void)p;
+    return holder;
+}
+
 static void do_db_tree_foreach_offheap(TreeDbTerm *,
 				       void (*)(ErlOffHeap *, void *),
 				       void *);
 
+void db_foreach_offheap_tree_common(TreeDbTerm *root,
+                                    void (*func)(ErlOffHeap *, void *),
+                                    void * arg)
+{
+    do_db_tree_foreach_offheap(root, func, arg);
+}
+
 static void db_foreach_offheap_tree(DbTable *tbl,
 				    void (*func)(ErlOffHeap *, void *),
 				    void * arg)
 {
-    do_db_tree_foreach_offheap(tbl->tree.root, func, arg);
+    db_foreach_offheap_tree_common(tbl->tree.root, func, arg);
 }
 
 
@@ -2033,13 +2375,14 @@ do_db_tree_foreach_offheap(TreeDbTerm *tdbt,
     do_db_tree_foreach_offheap(tdbt->right, func, arg);
 }
 
-static TreeDbTerm *linkout_tree(DbTableTree *tb, Eterm key) {
+static TreeDbTerm *linkout_tree(DbTableCommon *tb, TreeDbTerm **root,
+                                Eterm key, DbTreeStack *stack) {
     TreeDbTerm **tstack[STACK_NEED];
     int tpos = 0;
     int dstack[STACK_NEED+1];
     int dpos = 0;
     int state = 0;
-    TreeDbTerm **this = &tb->root;
+    TreeDbTerm **this = root;
     Sint c;
     int dir;
     TreeDbTerm *q = NULL;
@@ -2050,7 +2393,7 @@ static TreeDbTerm *linkout_tree(DbTableTree *tb, Eterm key) {
      * keep the balance. As in insert, we do the stacking ourselves.
      */
 
-    reset_static_stack(tb);
+    reset_stack(stack);
     dstack[dpos++] = DIR_END;
     for (;;) {
 	if (!*this) { /* Failure */
@@ -2076,30 +2419,30 @@ static TreeDbTerm *linkout_tree(DbTableTree *tb, Eterm key) {
 		tstack[tpos++] = this;
 		state = delsub(this);
 	    }
-	    erts_atomic_dec_nob(&tb->common.nitems);
+            DEC_NITEMS(((DbTable*)tb));
 	    break;
 	}
     }
     while (state && ( dir = dstack[--dpos] ) != DIR_END) {
 	this = tstack[--tpos];
 	if (dir == DIR_LEFT) {
-	    state = balance_left(this);
+	    state = tree_balance_left(this);
 	} else {
-	    state = balance_right(this);
+	    state = tree_balance_right(this);
 	}
     }
     return q;
 }
 
-static TreeDbTerm *linkout_object_tree(DbTableTree *tb, 
-				       Eterm object)
+static TreeDbTerm *linkout_object_tree(DbTableCommon *tb,  TreeDbTerm **root,
+				       Eterm object, DbTableTree *stack)
 {
     TreeDbTerm **tstack[STACK_NEED];
     int tpos = 0;
     int dstack[STACK_NEED+1];
     int dpos = 0;
     int state = 0;
-    TreeDbTerm **this = &tb->root;
+    TreeDbTerm **this = root;
     Sint c;
     int dir;
     TreeDbTerm *q = NULL;
@@ -2114,7 +2457,7 @@ static TreeDbTerm *linkout_object_tree(DbTableTree *tb,
     
     key = GETKEY(tb, tuple_val(object));
 
-    reset_static_stack(tb);
+    reset_static_stack(stack);
     dstack[dpos++] = DIR_END;
     for (;;) {
 	if (!*this) { /* Failure */
@@ -2128,7 +2471,7 @@ static TreeDbTerm *linkout_object_tree(DbTableTree *tb,
 	    tstack[tpos++] = this;
 	    this = &((*this)->right);
 	} else { /* Equal key, found the only possible matching object*/
-	    if (!db_eq(&tb->common,object,&(*this)->dbterm)) {
+	    if (!db_eq(tb,object,&(*this)->dbterm)) {
 		return NULL;
 	    }
 	    q = (*this);
@@ -2143,16 +2486,16 @@ static TreeDbTerm *linkout_object_tree(DbTableTree *tb,
 		tstack[tpos++] = this;
 		state = delsub(this);
 	    }
-	    erts_atomic_dec_nob(&tb->common.nitems);
+            DEC_NITEMS(((DbTable*)tb));
 	    break;
 	}
     }
     while (state && ( dir = dstack[--dpos] ) != DIR_END) {
 	this = tstack[--tpos];
 	if (dir == DIR_LEFT) {
-	    state = balance_left(this);
+	    state = tree_balance_left(this);
 	} else {
-	    state = balance_right(this);
+	    state = tree_balance_right(this);
 	}
     }
     return q;
@@ -2162,7 +2505,7 @@ static TreeDbTerm *linkout_object_tree(DbTableTree *tb,
 ** For the select functions, analyzes the pattern and determines which
 ** part of the tree should be searched. Also compiles the match program
 */
-static int analyze_pattern(DbTableTree *tb, Eterm pattern,
+static int analyze_pattern(DbTableCommon *tb, Eterm pattern,
                            extra_match_validator_t extra_validator, /* Optional callback */
                            struct mp_info *mpi)
 {
@@ -2173,17 +2516,12 @@ static int analyze_pattern(DbTableTree *tb, Eterm pattern,
     Eterm *ptpl;
     int i;
     int num_heads = 0;
-    Eterm key;
-    Eterm partly_bound;
-    int res;
-    Eterm least = 0;
-    Eterm most = 0;
+    Eterm least = THE_NON_VALUE;
+    Eterm most = THE_NON_VALUE;
+    enum ms_key_boundness boundness;
 
-    mpi->some_limitation = 1;
-    mpi->got_partial = 0;
-    mpi->something_can_match = 0;
+    mpi->key_boundness = MS_KEY_IMPOSSIBLE;
     mpi->mp = NULL;
-    mpi->save_term = NULL;
 
     for (lst = pattern; is_list(lst); lst = CDR(list_val(lst)))
 	++num_heads;
@@ -2204,6 +2542,7 @@ static int analyze_pattern(DbTableTree *tb, Eterm pattern,
         Eterm match;
         Eterm guard;
         Eterm body;
+        Eterm key;
 
 	ttpl = CAR(list_val(lst));
 	if (!is_tuple(ttpl)) {
@@ -2223,7 +2562,7 @@ static int analyze_pattern(DbTableTree *tb, Eterm pattern,
 	guards[i] = guard = ptpl[2];
 	bodies[i] = body = ptpl[3];
 
-        if(extra_validator != NULL && !extra_validator(tb->common.keypos, match, guard, body)) {
+        if(extra_validator != NULL && !extra_validator(tb->keypos, match, guard, body)) {
 	    if (buff != sbuff) {
 		erts_free(ERTS_ALC_T_DB_TMP, buff);
 	    }
@@ -2235,30 +2574,29 @@ static int analyze_pattern(DbTableTree *tb, Eterm pattern,
 	}
 	++i;
 
-	partly_bound = NIL;
-	res = key_given(tb, tpl, &(mpi->save_term), &partly_bound);
-	if ( res >= 0 ) {   /* Can match something */
-	    key = 0;
-	    mpi->something_can_match = 1;
-	    if (res > 0) {
-		key = GETKEY(tb,tuple_val(tpl)); 
-	    } else if (partly_bound != NIL) {
-		mpi->got_partial = 1;
-		key = partly_bound;
-	    } else {
-		mpi->some_limitation = 0;
-	    }
-	    if (key != 0) {
-		if (least == 0 || 
-		    partly_bound_can_match_lesser(key,least)) {
-		    least = key;
-		}
-		if (most == 0 || 
-		    partly_bound_can_match_greater(key,most)) {
-		    most = key;
-		}
-	    }
-	}
+        boundness = key_boundness(tb, tpl, &key);
+	switch (boundness)
+        {
+        case MS_KEY_BOUND:
+        case MS_KEY_PARTIALLY_BOUND:
+            if (is_non_value(least) || partly_bound_can_match_lesser(key,least)) {
+                least = key;
+            }
+            if (is_non_value(most) || partly_bound_can_match_greater(key,most)) {
+                most = key;
+            }
+            break;
+        case MS_KEY_IMPOSSIBLE:
+        case MS_KEY_UNBOUND:
+            break;
+        }
+        if (mpi->key_boundness > boundness)
+            mpi->key_boundness = boundness;
+    }
+
+    if (mpi->key_boundness == MS_KEY_BOUND && !CMP_EQ(least, most)) {
+        /* Several different bound keys */
+        mpi->key_boundness = MS_KEY_PARTIALLY_BOUND;
     }
     mpi->least = least;
     mpi->most = most;
@@ -2300,7 +2638,7 @@ static SWord do_free_tree_continue(DbTableTree *tb, SWord reds)
 		PUSH_NODE(&tb->static_stack, root);
 		root = p;
 	    } else {
-		free_term(tb, root);
+		free_term((DbTable*)tb, root);
 		if (--reds < 0) {
                     return reds;   /* Done enough for now */
                 }
@@ -2314,7 +2652,7 @@ static SWord do_free_tree_continue(DbTableTree *tb, SWord reds)
 /*
  * Deletion helpers
  */
-static int balance_left(TreeDbTerm **this) 
+int tree_balance_left(TreeDbTerm **this) 
 {
     TreeDbTerm *p, *p1, *p2;
     int b1, b2, h = 1;
@@ -2359,7 +2697,7 @@ static int balance_left(TreeDbTerm **this)
     return h;
 }
 
-static int balance_right(TreeDbTerm **this) 
+int tree_balance_right(TreeDbTerm **this) 
 {
     TreeDbTerm *p, *p1, *p2;
     int b1, b2, h = 1;
@@ -2431,7 +2769,7 @@ static int delsub(TreeDbTerm **this)
     h = 1;
     while (tpos && h) {
 	r = tstack[--tpos];
-	h = balance_right(r);
+	h = tree_balance_right(r);
     }
     return h;
 }
@@ -2440,11 +2778,30 @@ static int delsub(TreeDbTerm **this)
  * Helper for db_slot
  */
 
-static TreeDbTerm *slot_search(Process *p, DbTableTree *tb, Sint slot)
+static TreeDbTerm *slot_search(Process *p, TreeDbTerm *root,
+                               Sint slot, DbTable *tb,
+                               DbTableTree *stack_container,
+                               CATreeRootIterator *iter,
+                               int* is_EOT)
 {
     TreeDbTerm *this;
     TreeDbTerm *tmp;
-    DbTreeStack* stack = get_any_stack(tb);
+    TreeDbTerm *lastobj;
+    Eterm lastkey;
+    TreeDbTerm **pp;
+    DbTreeStack* stack;
+
+    if (iter) {
+        /* Find first non-empty tree */
+        while (!root) {
+            TreeDbTerm** pp = catree_find_next_root(iter, NULL);
+            if (!pp)
+                return NULL;
+            root = *pp;
+        }
+    }
+
+    stack = get_any_stack(tb,stack_container);
     ASSERT(stack != NULL);
 
     if (slot == 1) { /* Don't search from where we are if we are 
@@ -2456,57 +2813,92 @@ static TreeDbTerm *slot_search(Process *p, DbTableTree *tb, Sint slot)
 				are not recorded */
 	stack->pos = 0;
     }
-    if (EMPTY_NODE(stack)) {
-	this = tb->root;
-	if (this == NULL)
-	    goto done;
-	while (this->left != NULL){
-	    PUSH_NODE(stack, this);
-	    this = this->left;
-	}
-	PUSH_NODE(stack, this);
-	stack->slot = 1;
-    }
-    this = TOP_NODE(stack);
-    while (stack->slot != slot && this != NULL) {
-	if (slot > stack->slot) {
-	    if (this->right != NULL) {
-		this = this->right;
-		while (this->left != NULL) {
-		    PUSH_NODE(stack, this);
-		    this = this->left;
-		}
-		PUSH_NODE(stack, this);
-	    } else {
-		for (;;) {
-		    tmp = POP_NODE(stack);
-		    this = TOP_NODE(stack);
-		    if (this == NULL || this->left == tmp)
-			break;
-		}
-	    }		
-	    ++(stack->slot);
-	} else {
-	    if (this->left != NULL) {
-		this = this->left;
-		while (this->right != NULL) {
-		    PUSH_NODE(stack, this);
-		    this = this->right;
-		}
-		PUSH_NODE(stack, this);
-	    } else {
-		for (;;) {
-		    tmp = POP_NODE(stack);
-		    this = TOP_NODE(stack);
-		    if (this == NULL || this->right == tmp)
-			break;
-		}
-	    }		
-	    --(stack->slot);
-	}
+    while (1) {
+        if (EMPTY_NODE(stack)) {
+            this = root;
+            if (this == NULL)
+                goto next_root;
+            while (this->left != NULL){
+                PUSH_NODE(stack, this);
+                this = this->left;
+            }
+            PUSH_NODE(stack, this);
+            stack->slot++;
+        }
+        this = TOP_NODE(stack);
+        while (stack->slot != slot) {
+            ASSERT(this);
+            lastobj = this;
+            if (slot > stack->slot) {
+                if (this->right != NULL) {
+                    this = this->right;
+                    while (this->left != NULL) {
+                        PUSH_NODE(stack, this);
+                        this = this->left;
+                    }
+                    PUSH_NODE(stack, this);
+                } else {
+                    for (;;) {
+                        tmp = POP_NODE(stack);
+                        this = TOP_NODE(stack);
+                        if (!this)
+                            goto next_root;
+                        if (this->left == tmp)
+                            break;
+                    }
+                }
+                ++(stack->slot);
+            } else {
+                if (this->left != NULL) {
+                    this = this->left;
+                    while (this->right != NULL) {
+                        PUSH_NODE(stack, this);
+                        this = this->right;
+                    }
+                    PUSH_NODE(stack, this);
+                } else {
+                    for (;;) {
+                        tmp = POP_NODE(stack);
+                        this = TOP_NODE(stack);
+                        if (!this)
+                            goto next_root;
+                        if (this->right == tmp)
+                            break;
+                    }
+                }
+                --(stack->slot);
+            }
+        }
+         /* Found slot */
+        ASSERT(this);
+        break;
+
+next_root:
+        if (!iter) {
+            if (stack->slot == (slot-1)) {
+                *is_EOT = 1;
+            }
+            break; /* EOT */
+        }
+
+        ASSERT(slot > stack->slot);
+        if (lastobj) {
+            lastkey = GETKEY(tb, lastobj->dbterm.tpl);
+            lastobj = NULL;
+        }
+        pp = catree_find_next_root(iter, &lastkey);
+        if (!pp) {
+            if (stack->slot == (slot-1)) {
+                *is_EOT = 1;
+            }
+            break; /* EOT */
+        }
+        root = *pp;
+        stack->pos = 0;
+        find_next(&tb->common, root, stack, lastkey);
     }
-done:
-    release_stack(tb,stack);
+
+    release_stack(tb,stack_container,stack);
     return this;
 }
 
@@ -2514,7 +2906,8 @@ done:
  * Find next and previous in sort order
  */
 
-static TreeDbTerm *find_next(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
+static TreeDbTerm *find_next(DbTableCommon *tb, TreeDbTerm *root,
+                             DbTreeStack* stack, Eterm key) {
     TreeDbTerm *this;
     TreeDbTerm *tmp;
     Sint c;
@@ -2526,7 +2919,7 @@ static TreeDbTerm *find_next(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
 	}
     }
     if (EMPTY_NODE(stack)) { /* Have to rebuild the stack */
-	if (( this = tb->root ) == NULL)
+	if (( this = root ) == NULL)
 	    return NULL;
 	for (;;) {
 	    PUSH_NODE(stack, this);
@@ -2539,7 +2932,7 @@ static TreeDbTerm *find_next(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
 		    this = this->right;
 	    } else if (c < 0) {
 		if (this->left == NULL) /* Done */
-		    return this;
+                    goto found_next;
 		else
 		    this = this->left;
 	    } else
@@ -2554,8 +2947,6 @@ static TreeDbTerm *find_next(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
 	    this = this->left;
 	    PUSH_NODE(stack, this);
 	}
-	if (stack->slot > 0) 
-	    ++(stack->slot);
     } else {
 	do {
 	    tmp = POP_NODE(stack);
@@ -2564,13 +2955,17 @@ static TreeDbTerm *find_next(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
 		return NULL;
 	    }
 	} while (this->right == tmp);
-	if (stack->slot > 0) 
-	    ++(stack->slot);
     }
+
+found_next:
+    if (stack->slot > 0)
+        ++(stack->slot);
+
     return this;
 }
 
-static TreeDbTerm *find_prev(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
+static TreeDbTerm *find_prev(DbTableCommon *tb, TreeDbTerm *root,
+                             DbTreeStack* stack, Eterm key) {
     TreeDbTerm *this;
     TreeDbTerm *tmp;
     Sint c;
@@ -2582,7 +2977,7 @@ static TreeDbTerm *find_prev(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
 	}
     }
     if (EMPTY_NODE(stack)) { /* Have to rebuild the stack */
-	if (( this = tb->root ) == NULL)
+	if (( this = root ) == NULL)
 	    return NULL;
 	for (;;) {
 	    PUSH_NODE(stack, this);
@@ -2595,7 +2990,7 @@ static TreeDbTerm *find_prev(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
 		    this = this->left;
 	    } else if (c > 0) {
 		if (this->right == NULL) /* Done */
-		    return this;
+                    goto found_prev;
 		else
 		    this = this->right;
 	    } else
@@ -2610,8 +3005,6 @@ static TreeDbTerm *find_prev(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
 	    this = this->right;
 	    PUSH_NODE(stack, this);
 	}
-	if (stack->slot > 0) 
-	    --(stack->slot);
     } else {
 	do {
 	    tmp = POP_NODE(stack);
@@ -2620,74 +3013,112 @@ static TreeDbTerm *find_prev(DbTableTree *tb, DbTreeStack* stack, Eterm key) {
 		return NULL;
 	    }
 	} while (this->left == tmp);
-	if (stack->slot > 0) 
-	    --(stack->slot);
     }
+
+found_prev:
+    if (stack->slot > 0)
+        --(stack->slot);
+
     return this;
 }
 
-static TreeDbTerm *find_next_from_pb_key(DbTableTree *tb, DbTreeStack* stack,
-					 Eterm key)
+
+/* @brief Find object with smallest key of all larger than partially bound key.
+ * Can be used as a starting point for a reverse iteration with pb_key.
+ *
+ * @param pb_key The partially bound key. Example {42, '$1'}
+ * @param *rootpp Will return pointer to root pointer of tree with found object.
+ * @param iter Root iterator or NULL for plain DbTableTree.
+ * @param stack A stack to use. Will be cleared.
+ *
+ * @return found object or NULL if no such key exists.
+ */
+static TreeDbTerm *find_next_from_pb_key(DbTable *tbl,  TreeDbTerm*** rootpp,
+                                         DbTreeStack* stack, Eterm pb_key,
+                                         CATreeRootIterator* iter)
 {
+    TreeDbTerm* root;
     TreeDbTerm *this;
-    TreeDbTerm *tmp;
+    Uint candidate = 0;
     Sint c;
 
+    if (iter) {
+        *rootpp = catree_find_next_from_pb_key_root(pb_key, iter);
+        ASSERT(*rootpp);
+        root = **rootpp;
+    }
+    else {
+        *rootpp = &tbl->tree.root;
+        root = tbl->tree.root;
+    }
+
     /* spool the stack, we have to "re-search" */
     stack->pos = stack->slot = 0;
-    if (( this = tb->root ) == NULL)
+    if (( this = root ) == NULL)
 	return NULL;
     for (;;) {
 	PUSH_NODE(stack, this);
-	if (( c = cmp_partly_bound(key,GETKEY(tb, this->dbterm.tpl))) >= 0) {
+	if (( c = cmp_partly_bound(pb_key,GETKEY(tbl, this->dbterm.tpl))) >= 0) {
 	    if (this->right == NULL) {
-		do {
-		    tmp = POP_NODE(stack);
-		    if (( this = TOP_NODE(stack)) == NULL) {
-			return NULL;
-		    }
-		} while (this->right == tmp);
-		return this;
-	    } else
-		this = this->right;
+                stack->pos = candidate;
+                return TOP_NODE(stack);
+	    }
+            this = this->right;
 	} else /*if (c < 0)*/ {
 	    if (this->left == NULL) /* Done */
 		return this;
-	    else
-		this = this->left;
+            candidate = stack->pos;
+            this = this->left;
 	} 
     }
 }
 
-static TreeDbTerm *find_prev_from_pb_key(DbTableTree *tb, DbTreeStack* stack,
-					 Eterm key)
+/* @brief Find object with largest key of all smaller than partially bound key.
+ * Can be used as a starting point for a forward iteration with pb_key.
+ *
+ * @param pb_key The partially bound key. Example {42, '$1'}
+ * @param *rootpp Will return pointer to root pointer of found object.
+ * @param iter Root iterator or NULL for plain DbTableTree.
+ * @param stack A stack to use. Will be cleared.
+ *
+ * @return found object or NULL if no such key exists.
+ */
+static TreeDbTerm *find_prev_from_pb_key(DbTable *tbl, TreeDbTerm*** rootpp,
+                                         DbTreeStack* stack, Eterm pb_key,
+                                         CATreeRootIterator* iter)
 {
+    TreeDbTerm* root;
     TreeDbTerm *this;
-    TreeDbTerm *tmp;
+    Uint candidate = 0;
     Sint c;
 
+    if (iter) {
+        *rootpp = catree_find_prev_from_pb_key_root(pb_key, iter);
+        ASSERT(*rootpp);
+        root = **rootpp;
+    }
+    else {
+        *rootpp = &tbl->tree.root;
+        root = tbl->tree.root;
+    }
+
     /* spool the stack, we have to "re-search" */
     stack->pos = stack->slot = 0;
-    if (( this = tb->root ) == NULL)
+    if (( this = root ) == NULL)
 	return NULL;
     for (;;) {
 	PUSH_NODE(stack, this);
-	if (( c = cmp_partly_bound(key,GETKEY(tb, this->dbterm.tpl))) <= 0) {
+	if (( c = cmp_partly_bound(pb_key,GETKEY(tbl, this->dbterm.tpl))) <= 0) {
 	    if (this->left == NULL) {
-		do {
-		    tmp = POP_NODE(stack);
-		    if (( this = TOP_NODE(stack)) == NULL) {
-			return NULL;
-		    }
-		} while (this->left == tmp);
-		return this;
-	    } else
-		this = this->left;
-	} else /*if (c < 0)*/ {
+                stack->pos = candidate;
+                return TOP_NODE(stack);
+	    }
+            this = this->left;
+	} else /*if (c > 0)*/ {
 	    if (this->right == NULL) /* Done */
 		return this;
-	    else
-		this = this->right;
+            candidate = stack->pos;
+            this = this->right;
 	} 
     }
 }
@@ -2696,16 +3127,17 @@ static TreeDbTerm *find_prev_from_pb_key(DbTableTree *tb, DbTreeStack* stack,
 /*
  * Just lookup a node
  */
-static TreeDbTerm *find_node(DbTableTree *tb, Eterm key)
+static TreeDbTerm *find_node(DbTableCommon *tb, TreeDbTerm *root,
+                             Eterm key, DbTableTree *stack_container)
 {
     TreeDbTerm *this;
     Sint res;
-    DbTreeStack* stack = get_static_stack(tb);
+    DbTreeStack* stack = get_static_stack(stack_container);
 
     if(!stack || EMPTY_NODE(stack)
        || !cmp_key_eq(tb, key, (this=TOP_NODE(stack)))) {
 
-	this = tb->root;
+	this = root;
 	while (this != NULL && (res = cmp_key(tb,key,this)) != 0) {
 	    if (res < 0)
 		this = this->left;
@@ -2714,7 +3146,7 @@ static TreeDbTerm *find_node(DbTableTree *tb, Eterm key)
 	}
     }
     if (stack) {
-	release_stack(tb,stack);
+	release_stack((DbTable*)tb,stack_container,stack);
     }
     return this;
 }
@@ -2722,12 +3154,12 @@ static TreeDbTerm *find_node(DbTableTree *tb, Eterm key)
 /*
  * Lookup a node and return the address of the node pointer in the tree
  */
-static TreeDbTerm **find_node2(DbTableTree *tb, Eterm key)
+static TreeDbTerm **find_node2(DbTableCommon *tb, TreeDbTerm **root, Eterm key)
 {
     TreeDbTerm **this;
     Sint res;
 
-    this = &tb->root;
+    this = root;
     while ((*this) != NULL && (res = cmp_key(tb, key, *this)) != 0) {
 	if (res < 0)
 	    this = &((*this)->left);
@@ -2744,7 +3176,8 @@ static TreeDbTerm **find_node2(DbTableTree *tb, Eterm key)
  * Tries to reuse the existing stack for performance.
  */
 
-static TreeDbTerm **find_ptr(DbTableTree *tb, DbTreeStack *stack, TreeDbTerm *this) {
+static TreeDbTerm **find_ptr(DbTableCommon *tb, TreeDbTerm **root,
+                             DbTreeStack *stack, TreeDbTerm *this) {
     Eterm key = GETKEY(tb, this->dbterm.tpl);
     TreeDbTerm *tmp;
     TreeDbTerm *parent;
@@ -2757,7 +3190,7 @@ static TreeDbTerm **find_ptr(DbTableTree *tb, DbTreeStack *stack, TreeDbTerm *th
 	}
     }
     if (EMPTY_NODE(stack)) { /* Have to rebuild the stack */
-	if (( tmp = tb->root ) == NULL)
+	if (( tmp = *root ) == NULL)
 	    return NULL;
 	for (;;) {
 	    PUSH_NODE(stack, tmp);
@@ -2783,7 +3216,7 @@ static TreeDbTerm **find_ptr(DbTableTree *tb, DbTreeStack *stack, TreeDbTerm *th
 
     parent = TOPN_NODE(stack, 1);
     if (parent == NULL)
-        return ((this != tb->root) ? NULL : &(tb->root));
+        return ((this != *root) ? NULL : root);
     if (parent->left == this)
         return &(parent->left);
     if (parent->right == this)
@@ -2791,12 +3224,11 @@ static TreeDbTerm **find_ptr(DbTableTree *tb, DbTreeStack *stack, TreeDbTerm *th
     return NULL;
 }
 
-static int
-db_lookup_dbterm_tree(Process *p, DbTable *tbl, Eterm key, Eterm obj,
-                      DbUpdateHandle* handle)
+int db_lookup_dbterm_tree_common(Process *p, DbTable *tbl, TreeDbTerm **root,
+                                 Eterm key, Eterm obj, DbUpdateHandle* handle,
+                                 DbTableTree *stack_container)
 {
-    DbTableTree *tb = &tbl->tree;
-    TreeDbTerm **pp = find_node2(tb, key);
+    TreeDbTerm **pp = find_node2(&tbl->common, root, key);
     int flags = 0;
 
     if (pp == NULL) {
@@ -2807,18 +3239,19 @@ db_lookup_dbterm_tree(Process *p, DbTable *tbl, Eterm key, Eterm obj,
             int arity = arityval(*objp);
             Eterm *htop, *hend;
 
-            ASSERT(arity >= tb->common.keypos);
+            ASSERT(arity >= tbl->common.keypos);
             htop = HAlloc(p, arity + 1);
             hend = htop + arity + 1;
             sys_memcpy(htop, objp, sizeof(Eterm) * (arity + 1));
-            htop[tb->common.keypos] = key;
+            htop[tbl->common.keypos] = key;
             obj = make_tuple(htop);
 
-            if (db_put_tree(tbl, obj, 1) != DB_ERROR_NONE) {
+            if (db_put_tree_common(&tbl->common, root,
+                                   obj, 1, stack_container) != DB_ERROR_NONE) {
                 return 0;
             }
 
-            pp = find_node2(tb, key);
+            pp = find_node2(&tbl->common, root, key);
             ASSERT(pp != NULL);
             HRelease(p, hend, htop);
             flags |= DB_NEW_OBJECT;
@@ -2833,21 +3266,28 @@ db_lookup_dbterm_tree(Process *p, DbTable *tbl, Eterm key, Eterm obj,
     return 1;
 }
 
-static void
-db_finalize_dbterm_tree(int cret, DbUpdateHandle *handle)
+static int
+db_lookup_dbterm_tree(Process *p, DbTable *tbl, Eterm key, Eterm obj,
+                      DbUpdateHandle* handle)
 {
-    DbTable *tbl = handle->tb;
     DbTableTree *tb = &tbl->tree;
+    return db_lookup_dbterm_tree_common(p, tbl, &tb->root, key, obj, handle, tb);
+}
+
+void db_finalize_dbterm_tree_common(int cret, DbUpdateHandle *handle,
+                                    DbTableTree *stack_container)
+{
+    DbTable *tbl = handle->tb;
     TreeDbTerm *bp = (TreeDbTerm *) *handle->bp;
 
     if (handle->flags & DB_NEW_OBJECT && cret != DB_ERROR_NONE) {
         Eterm ret;
-        db_erase_tree(tbl, GETKEY(tb, bp->dbterm.tpl), &ret);
+        db_erase_tree(tbl, GETKEY(&tbl->common, bp->dbterm.tpl), &ret);
     } else if (handle->flags & DB_MUST_RESIZE) {
 	db_finalize_resize(handle, offsetof(TreeDbTerm,dbterm));
-        reset_static_stack(tb);
+        reset_static_stack(stack_container);
 
-        free_term(tb, bp);
+        free_term(tbl, bp);
     }
 #ifdef DEBUG
     handle->dbterm = 0;
@@ -2855,156 +3295,207 @@ db_finalize_dbterm_tree(int cret, DbUpdateHandle *handle)
     return;
 }   
 
+static void
+db_finalize_dbterm_tree(int cret, DbUpdateHandle *handle)
+{
+    DbTable *tbl = handle->tb;
+    DbTableTree *tb = &tbl->tree;
+    db_finalize_dbterm_tree_common(cret, handle, tb);
+}
+
 /*
  * Traverse the tree with a callback function, used by db_match_xxx
  */
-static void traverse_backwards(DbTableTree *tb,
+static void traverse_backwards(DbTableCommon *tb,
 			       DbTreeStack* stack,
 			       Eterm lastkey,
-			       int (*doit)(DbTableTree *,
-					   TreeDbTerm *,
-					   void *,
-					   int),
-			       void *context) 
+                               traverse_doit_funcT* doit,
+                               struct select_common *context,
+                               CATreeRootIterator* iter)
 {
     TreeDbTerm *this, *next;
+    TreeDbTerm** root = context->root;
 
     if (lastkey == THE_NON_VALUE) {
-	stack->pos = stack->slot = 0;
-	if (( this = tb->root ) == NULL) {
-	    return;
-	}
-	while (this != NULL) {
-	    PUSH_NODE(stack, this);
-	    this = this->right;
-	}
-	this = TOP_NODE(stack);
-	next = find_prev(tb, stack, GETKEY(tb, this->dbterm.tpl));
-	if (!((*doit)(tb, this, context, 0)))
-	    return;
+        if (iter) {
+            while (*root == NULL) {
+                root = catree_find_prev_root(iter, NULL);
+                if (!root)
+                    return;
+            }
+            context->root = root;
+        }
+        stack->pos = stack->slot = 0;
+        next = *root;
+        while (next != NULL) {
+            PUSH_NODE(stack, next);
+            next = next->right;
+        }
+        next = TOP_NODE(stack);
     } else {
-	next = find_prev(tb, stack, lastkey);
+        next = find_prev(tb, *root, stack, lastkey);
     }
 
-    while ((this = next) != NULL) {
-	next = find_prev(tb, stack, GETKEY(tb, this->dbterm.tpl));
-	if (!((*doit)(tb, this, context, 0)))
-	    return;
+    while (1) {
+        while (next) {
+            this = next;
+            lastkey = GETKEY(tb, this->dbterm.tpl);
+            next = find_prev(tb, *root, stack, lastkey);
+            if (!((*doit)(tb, this, context, 0)))
+                return;
+        }
+
+        if (!iter)
+            return;
+        ASSERT(is_value(lastkey));
+        root = catree_find_prev_root(iter, &lastkey);
+        if (!root)
+            return;
+        context->root = root;
+        stack->pos = stack->slot = 0;
+        next = find_prev(tb, *root, stack, lastkey);
     }
 }
 
 /*
  * Traverse the tree with a callback function, used by db_match_xxx
  */
-static void traverse_forward(DbTableTree *tb,
+static void traverse_forward(DbTableCommon *tb,
 			     DbTreeStack* stack,
 			     Eterm lastkey,
-			     int (*doit)(DbTableTree *,
-					 TreeDbTerm *,
-					 void *,
-					 int),
-			     void *context) 
+                             traverse_doit_funcT* doit,
+                             struct select_common *context,
+                             CATreeRootIterator* iter)
 {
     TreeDbTerm *this, *next;
+    TreeDbTerm **root = context->root;
 
     if (lastkey == THE_NON_VALUE) {
-	stack->pos = stack->slot = 0;
-	if (( this = tb->root ) == NULL) {
-	    return;
-	}
-	while (this != NULL) {
-	    PUSH_NODE(stack, this);
-	    this = this->left;
-	}
-	this = TOP_NODE(stack);
-	next = find_next(tb, stack, GETKEY(tb, this->dbterm.tpl));
-	if (!((*doit)(tb, this, context, 1)))
-	    return;
+        if (iter) {
+            while (*root == NULL) {
+                root = catree_find_next_root(iter, NULL);
+                if (!root)
+                    return;
+            }
+            context->root = root;
+        }
+        stack->pos = stack->slot = 0;
+        next = *root;
+        while (next != NULL) {
+            PUSH_NODE(stack, next);
+            next = next->left;
+        }
+        next = TOP_NODE(stack);
     } else {
-	next = find_next(tb, stack, lastkey);
+        next = find_next(tb, *root, stack, lastkey);
     }
 
-    while ((this = next) != NULL) {
-	next = find_next(tb, stack, GETKEY(tb, this->dbterm.tpl));
-	if (!((*doit)(tb, this, context, 1)))
-	    return;
+    while (1) {
+        while (next) {
+            this = next;
+            lastkey = GETKEY(tb, this->dbterm.tpl);
+            next = find_next(tb, *root, stack, lastkey);
+            if (!((*doit)(tb, this, context, 1)))
+                return;
+        }
+
+        if (!iter)
+            return;
+        ASSERT(is_value(lastkey));
+        root = catree_find_next_root(iter, &lastkey);
+        if (!root)
+            return;
+        context->root = root;
+        stack->pos = stack->slot = 0;
+        next = find_next(tb, *root, stack, lastkey);
     }
 }
 
 /*
  * Traverse the tree with an update callback function, used by db_select_replace
  */
-static void traverse_update_backwards(DbTableTree *tb,
+static void traverse_update_backwards(DbTableCommon *tb,
                                       DbTreeStack* stack,
                                       Eterm lastkey,
-                                      int (*doit)(DbTableTree*,
+                                      int (*doit)(DbTableCommon*,
                                                   TreeDbTerm**,
-                                                  void*,
+                                                  struct select_common*,
                                                   int),
-                                      void* context)
+                                      struct select_common* context,
+                                      CATreeRootIterator* iter)
 {
     int res;
     TreeDbTerm *this, *next, **this_ptr;
+    TreeDbTerm** root = context->root;
 
     if (lastkey == THE_NON_VALUE) {
-        stack->pos = stack->slot = 0;
-        if (( this = tb->root ) == NULL) {
-            return;
+        if (iter) {
+            while (*root == NULL) {
+                root = catree_find_prev_root(iter, NULL);
+                if (!root)
+                    return;
+                context->root = root;
+            }
         }
-        while (this != NULL) {
-            PUSH_NODE(stack, this);
-            this = this->right;
+        stack->pos = stack->slot = 0;
+        next = *root;
+        while (next) {
+            PUSH_NODE(stack, next);
+            next = next->right;
         }
-        this = TOP_NODE(stack);
-        this_ptr = find_ptr(tb, stack, this);
-        ASSERT(this_ptr != NULL);
-        res = (*doit)(tb, this_ptr, context, 0);
-        REPLACE_TOP_NODE(stack, *this_ptr);
-        next = find_prev(tb, stack, GETKEY(tb, (*this_ptr)->dbterm.tpl));
-        if (!res)
-            return;
-    } else {
-        next = find_prev(tb, stack, lastkey);
+        next = TOP_NODE(stack);
     }
+    else
+        next = find_prev(tb, *root, stack, lastkey);
+
+
+    while (1) {
+        while (next) {
+            this = next;
+            this_ptr = find_ptr(tb, root, stack, this);
+            ASSERT(this_ptr != NULL);
+            res = (*doit)(tb, this_ptr, context, 0);
+            this = *this_ptr;
+            REPLACE_TOP_NODE(stack, this);
+            if (!res)
+                return;
+            lastkey = GETKEY(tb, this->dbterm.tpl);
+            next = find_prev(tb, *root, stack, lastkey);
+        }
 
-    while ((this = next) != NULL) {
-        this_ptr = find_ptr(tb, stack, this);
-        ASSERT(this_ptr != NULL);
-        res = (*doit)(tb, this_ptr, context, 0);
-        REPLACE_TOP_NODE(stack, *this_ptr);
-        next = find_prev(tb, stack, GETKEY(tb, (*this_ptr)->dbterm.tpl));
-        if (!res)
+        if (!iter)
+            return;
+        ASSERT(is_value(lastkey));
+        root = catree_find_prev_root(iter, &lastkey);
+        if (!root)
             return;
+        context->root = root;
+        stack->pos = stack->slot = 0;
+        next = find_prev(tb, *root, stack, lastkey);
     }
 }
 
-/*
- * Returns 0 if not given 1 if given and -1 on no possible match
- * if key is given; *ret is set to point to the object concerned.
- */
-static int key_given(DbTableTree *tb, Eterm pattern, TreeDbTerm ***ret,
-		     Eterm *partly_bound)
+static enum ms_key_boundness key_boundness(DbTableCommon *tb,
+                                           Eterm pattern, Eterm *keyp)
 {
-    TreeDbTerm **this;
     Eterm key;
 
-    ASSERT(ret != NULL);
     if (pattern == am_Underscore || db_is_variable(pattern) != -1)
-	return 0;
-    key = db_getkey(tb->common.keypos, pattern);
+	return MS_KEY_UNBOUND;
+    key = db_getkey(tb->keypos, pattern);
     if (is_non_value(key))
-	return -1;  /* can't possibly match anything */
+	return MS_KEY_IMPOSSIBLE;  /* can't possibly match anything */
     if (!db_has_variable(key)) {   /* Bound key */
-	if (( this = find_node2(tb, key) ) == NULL) {
-	    return -1;
-	}
-	*ret = this;
-	return 1;
-    } else if (partly_bound != NULL && key != am_Underscore && 
-	       db_is_variable(key) < 0 && !db_has_map(key))
-	*partly_bound = key;
+        *keyp = key;
+	return MS_KEY_BOUND;
+    } else if (key != am_Underscore &&
+	       db_is_variable(key) < 0 && !db_has_map(key)) {
+
+	*keyp = key;
+        return MS_KEY_PARTIALLY_BOUND;
+    }
 	
-    return 0;
+    return MS_KEY_UNBOUND;
 }
 
 
@@ -3072,7 +3563,8 @@ static Sint do_cmp_partly_bound(Eterm a, Eterm b, int *done)
     }
 }
 
-static Sint cmp_partly_bound(Eterm partly_bound_key, Eterm bound_key) {
+Sint cmp_partly_bound(Eterm partly_bound_key, Eterm bound_key)
+{
     int done = 0;
     Sint ret = do_cmp_partly_bound(partly_bound_key, bound_key, &done);
 #ifdef HARDDEBUG
@@ -3118,7 +3610,7 @@ static int partly_bound_can_match_lesser(Eterm partly_bound_1,
     if (ret)
 	erts_fprintf(stderr," can match lesser than ");
     else
-	erts_fprintf(stderr," can not match lesser than ");
+	erts_fprintf(stderr," cannot match lesser than ");
     erts_fprintf(stderr,"%T\n",partly_bound_2);
 #endif
     return ret;
@@ -3136,7 +3628,7 @@ static int partly_bound_can_match_greater(Eterm partly_bound_1,
     if (ret)
 	erts_fprintf(stderr," can match greater than ");
     else
-	erts_fprintf(stderr," can not match greater than ");
+	erts_fprintf(stderr," cannot match greater than ");
     erts_fprintf(stderr,"%T\n",partly_bound_2);
 #endif
     return ret;
@@ -3288,7 +3780,8 @@ static int do_partly_bound_can_match_greater(Eterm a, Eterm b,
  * Callback functions for the different match functions
  */
 
-static int doit_select(DbTableTree *tb, TreeDbTerm *this, void *ptr,
+static int doit_select(DbTableCommon *tb, TreeDbTerm *this,
+                       struct select_common* ptr,
 		       int forward)
 {
     struct select_context *sc = (struct select_context *) ptr;
@@ -3306,24 +3799,18 @@ static int doit_select(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 			   GETKEY_WITH_POS(sc->keypos, this->dbterm.tpl)) > 0))) {
 	return 0;
     }
-    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &this->dbterm, &hp, 2);
+    ret = db_match_dbterm(tb, sc->p,sc->mp, &this->dbterm, &hp, 2);
     if (is_value(ret)) {
 	sc->accum = CONS(hp, ret, sc->accum);
     }
-    if (MBUF(sc->p)) {
-	/*
-	 * Force a trap and GC if a heap fragment was created. Many heap fragments
-	 * make the GC slow.
-	 */
-	sc->max = 0;
-    }
     if (--(sc->max) <= 0) {
 	return 0;
     }
     return 1;
 }
 
-static int doit_select_count(DbTableTree *tb, TreeDbTerm *this, void *ptr,
+static int doit_select_count(DbTableCommon *tb, TreeDbTerm *this,
+                             struct select_common* ptr,
 			     int forward)
 {
     struct select_count_context *sc = (struct select_count_context *) ptr;
@@ -3337,7 +3824,7 @@ static int doit_select_count(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 			  GETKEY_WITH_POS(sc->keypos, this->dbterm.tpl)) > 0)) {
 	return 0;
     }
-    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &this->dbterm, NULL, 0);
+    ret = db_match_dbterm(tb, sc->p, sc->mp, &this->dbterm, NULL, 0);
     if (ret == am_true) {
 	++(sc->got);
     }
@@ -3347,7 +3834,8 @@ static int doit_select_count(DbTableTree *tb, TreeDbTerm *this, void *ptr,
     return 1;
 }
 
-static int doit_select_chunk(DbTableTree *tb, TreeDbTerm *this, void *ptr,
+static int doit_select_chunk(DbTableCommon *tb, TreeDbTerm *this,
+                             struct select_common* ptr,
 			     int forward)
 {
     struct select_context *sc = (struct select_context *) ptr;
@@ -3366,18 +3854,11 @@ static int doit_select_chunk(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 	return 0;
     }
 
-    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &this->dbterm, &hp, 2);
+    ret = db_match_dbterm(tb, sc->p, sc->mp, &this->dbterm, &hp, 2);
     if (is_value(ret)) {
 	++(sc->got);
 	sc->accum = CONS(hp, ret, sc->accum);
     }
-    if (MBUF(sc->p)) {
-	/*
-	 * Force a trap and GC if a heap fragment was created. Many heap fragments
-	 * make the GC slow.
-	 */
-	sc->max = 0;
-    }
     if (--(sc->max) <= 0 || sc->got == sc->chunk_size) {
 	return 0;
     }
@@ -3385,7 +3866,8 @@ static int doit_select_chunk(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 }
 
 
-static int doit_select_delete(DbTableTree *tb, TreeDbTerm *this, void *ptr,
+static int doit_select_delete(DbTableCommon *tb, TreeDbTerm *this,
+                              struct select_common *ptr,
 			      int forward)
 {
     struct select_delete_context *sc = (struct select_delete_context *) ptr;
@@ -3393,7 +3875,7 @@ static int doit_select_delete(DbTableTree *tb, TreeDbTerm *this, void *ptr,
     Eterm key;
 
     if (sc->erase_lastterm)
-	free_term(tb, sc->lastterm);
+	free_term((DbTable*)tb, sc->lastterm);
     sc->erase_lastterm = 0;
     sc->lastterm = this;
     
@@ -3401,10 +3883,10 @@ static int doit_select_delete(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 	cmp_partly_bound(sc->end_condition, 
 			 GETKEY_WITH_POS(sc->keypos, this->dbterm.tpl)) > 0)
 	return 0;
-    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &this->dbterm, NULL, 0);
+    ret = db_match_dbterm(tb, sc->p, sc->mp, &this->dbterm, NULL, 0);
     if (ret == am_true) {
 	key = GETKEY(sc->tb, this->dbterm.tpl);
-	linkout_tree(sc->tb, key);
+	linkout_tree(sc->tb, sc->common.root, key, sc->stack);
 	sc->erase_lastterm = 1;
 	++sc->accum;
     }
@@ -3414,7 +3896,8 @@ static int doit_select_delete(DbTableTree *tb, TreeDbTerm *this, void *ptr,
     return 1;
 }
 
-static int doit_select_replace(DbTableTree *tb, TreeDbTerm **this, void *ptr,
+static int doit_select_replace(DbTableCommon *tb, TreeDbTerm **this,
+                               struct select_common* ptr,
                                int forward)
 {
     struct select_replace_context *sc = (struct select_replace_context *) ptr;
@@ -3428,13 +3911,13 @@ static int doit_select_replace(DbTableTree *tb, TreeDbTerm **this, void *ptr,
 			  GETKEY_WITH_POS(sc->keypos, (*this)->dbterm.tpl)) > 0)) {
 	return 0;
     }
-    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &(*this)->dbterm, NULL, 0);
+    ret = db_match_dbterm(tb, sc->p, sc->mp, &(*this)->dbterm, NULL, 0);
 
     if (is_value(ret)) {
         TreeDbTerm* new;
         TreeDbTerm* old = *this;
 #ifdef DEBUG
-        Eterm key = db_getkey(tb->common.keypos, ret);
+        Eterm key = db_getkey(tb->keypos, ret);
         ASSERT(is_value(key));
         ASSERT(cmp_key(tb, key, old) == 0);
 #endif
@@ -3444,7 +3927,7 @@ static int doit_select_replace(DbTableTree *tb, TreeDbTerm **this, void *ptr,
         new->balance = old->balance;
         sc->lastobj = new->dbterm.tpl;
         *this = new;
-        free_term(tb, old);
+        free_term((DbTable*)tb, old);
         ++(sc->replaced);
     }
     if (--(sc->max) <= 0) {
@@ -3453,8 +3936,14 @@ static int doit_select_replace(DbTableTree *tb, TreeDbTerm **this, void *ptr,
     return 1;
 }
 
+void
+erts_db_foreach_thr_prgr_offheap_tree(void (*func)(ErlOffHeap *, void *),
+                                      void *arg)
+{
+}
+
 #ifdef TREE_DEBUG
-static void do_dump_tree2(DbTableTree* tb, int to, void *to_arg, int show,
+static void do_dump_tree2(DbTableCommon* tb, int to, void *to_arg, int show,
 			  TreeDbTerm *t, int offset)
 {
     if (t == NULL)
@@ -3463,7 +3952,7 @@ static void do_dump_tree2(DbTableTree* tb, int to, void *to_arg, int show,
     if (show) {
 	const char* prefix;
 	Eterm term;
-	if (tb->common.compress) {
+	if (tb->compress) {
 	    prefix = "key=";
 	    term = GETKEY(tb, t->dbterm.tpl);
 	}
@@ -3518,7 +4007,7 @@ static void check_slot_pos(DbTableTree *tb)
 		   "element position %d is really 0x%08X, when stack says "
 		   "it's 0x%08X\n", tb->stack.slot, t, 
 		   tb->stack.array[tb->stack.pos - 1]);
-	do_dump_tree2(tb, ERTS_PRINT_STDERR, NULL, 1, tb->root, 0);
+	do_dump_tree2(&tb->common, ERTS_PRINT_STDERR, NULL, 1, tb->root, 0);
     }
 }
 	
@@ -3533,14 +4022,14 @@ static void check_saved_stack(DbTableTree *tb)
      if (t != stack->array[0]) {
 	 erts_fprintf(stderr,"tb->stack[0] is 0x%08X, should be 0x%08X\n",
 		      stack->array[0], t);
-	 do_dump_tree2(tb, ERTS_PRINT_STDERR, NULL, 1, tb->root, 0);
+	 do_dump_tree2(&tb->common, ERTS_PRINT_STDERR, NULL, 1, tb->root, 0);
 	 return;
      }
      while (n < stack->pos) {
 	 if (t == NULL) {
 	     erts_fprintf(stderr, "NULL pointer in tree when stack not empty,"
 			" stack depth is %d\n", n);
-	     do_dump_tree2(tb, ERTS_PRINT_STDERR, NULL, 1, tb->root, 0);
+	     do_dump_tree2(&tb->common, ERTS_PRINT_STDERR, NULL, 1, tb->root, 0);
 	     return;
 	 }
 	 n++;
@@ -3554,7 +4043,7 @@ static void check_saved_stack(DbTableTree *tb)
 			    "represent child pointer in tree!"
 			    "(left == 0x%08X, right == 0x%08X\n", 
 			    n, tb->stack[n], t->left, t->right);
-		 do_dump_tree2(tb, ERTS_PRINT_STDERR, NULL, 1, tb->root, 0);
+		 do_dump_tree2(&tb->common, ERTS_PRINT_STDERR, NULL, 1, tb->root, 0);
 		 return;
 	     }
 	 }
@@ -3573,7 +4062,7 @@ static int check_table_tree(DbTableTree* tb, TreeDbTerm *t)
 	erts_fprintf(stderr,"balance = %d, left = 0x%08X, right = 0x%08X\n",
 		     t->balance, t->left, t->right);
 	erts_fprintf(stderr,"\nDump:\n---------------------------------\n");
-	do_dump_tree2(tb, ERTS_PRINT_STDERR, NULL, 1, t, 0);
+	do_dump_tree2(&tb->common, ERTS_PRINT_STDERR, NULL, 1, t, 0);
 	erts_fprintf(stderr,"\n---------------------------------\n");
     }
     return ((rh > lh) ? rh : lh) + 1;
diff --git a/erts/emulator/beam/erl_db_tree.h b/erts/emulator/beam/erl_db_tree.h
index 54da2a6bc1..06e0005801 100644
--- a/erts/emulator/beam/erl_db_tree.h
+++ b/erts/emulator/beam/erl_db_tree.h
@@ -53,4 +53,8 @@ void db_initialize_tree(void);
 
 int db_create_tree(Process *p, DbTable *tbl);
 
+void
+erts_db_foreach_thr_prgr_offheap_tree(void (*func)(ErlOffHeap *, void *),
+                                      void *arg);
+
 #endif /* _DB_TREE_H */
diff --git a/erts/emulator/beam/erl_db_tree_util.h b/erts/emulator/beam/erl_db_tree_util.h
new file mode 100644
index 0000000000..ba4a8f79e5
--- /dev/null
+++ b/erts/emulator/beam/erl_db_tree_util.h
@@ -0,0 +1,174 @@
+/*
+ * %CopyrightBegin%
+ * 
+ * Copyright Ericsson AB 1998-2016. All Rights Reserved.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * %CopyrightEnd%
+ */
+
+#ifndef _DB_TREE_UTIL_H
+#define _DB_TREE_UTIL_H
+
+/*
+** Internal functions and macros used by both the CA tree and the AVL tree
+*/
+
+
+#if defined(ARCH_32)
+/*
+** A stack of this size is enough for an AVL tree with more than
+** 0xFFFFFFFF elements. May be subject to change if
+** the datatype of the element counter is changed to a 64 bit integer.
+** The Maximal height of an AVL tree is calculated as:
+** h(n) <= 1.4404 * log(n + 2) - 0.328
+** Where n denotes the number of nodes, h(n) the height of the tree
+** with n nodes and log is the binary logarithm.
+*/
+#define STACK_NEED 50
+#elif defined(ARCH_64)
+/*
+** A stack of this size is enough for an AVL tree with more than
+** 2^61 elements. 
+** The Maximal height of an AVL tree is calculated as above.
+*/
+#define STACK_NEED 90
+#else
+#error "Unsported architecture"
+#endif
+
+
+
+#define PUSH_NODE(Dtt, Tdt)                     \
+    ((Dtt)->array[(Dtt)->pos++] = Tdt)
+
+#define POP_NODE(Dtt)			\
+     (((Dtt)->pos) ? 			\
+      (Dtt)->array[--((Dtt)->pos)] : NULL)
+
+#define TOP_NODE(Dtt)                   \
+     ((Dtt->pos) ? 			\
+      (Dtt)->array[(Dtt)->pos - 1] : NULL)
+
+#define EMPTY_NODE(Dtt) (TOP_NODE(Dtt) == NULL)
+
+#define DEC_NITEMS(DB)                                                  \
+    erts_flxctr_dec(&(DB)->common.counters, ERTS_DB_TABLE_NITEMS_COUNTER_ID)
+
+static ERTS_INLINE void free_term(DbTable *tb, TreeDbTerm* p)
+{
+    db_free_term(tb, p, offsetof(TreeDbTerm, dbterm));
+}
+
+/*
+** Some macros for "direction stacks"
+*/
+#define DIR_LEFT 0
+#define DIR_RIGHT 1
+#define DIR_END 2 
+
+static ERTS_INLINE Sint cmp_key(DbTableCommon* tb, Eterm key, TreeDbTerm* obj) {
+    return CMP(key, GETKEY(tb,obj->dbterm.tpl));
+}
+
+int tree_balance_left(TreeDbTerm **this);
+int tree_balance_right(TreeDbTerm **this);
+
+int db_first_tree_common(Process *p, DbTable *tbl, TreeDbTerm *root,
+                         Eterm *ret, DbTableTree *stack_container);
+int db_next_tree_common(Process *p, DbTable *tbl,
+                        TreeDbTerm *root, Eterm key,
+                        Eterm *ret, DbTreeStack* stack);
+int db_last_tree_common(Process *p, DbTable *tbl, TreeDbTerm *root,
+                        Eterm *ret, DbTableTree *stack_container);
+int db_prev_tree_common(Process *p, DbTable *tbl, TreeDbTerm *root, Eterm key,
+                        Eterm *ret, DbTreeStack* stack);
+int db_put_tree_common(DbTableCommon *tb, TreeDbTerm **root, Eterm obj,
+                       int key_clash_fail, DbTableTree *stack_container);
+int db_get_tree_common(Process *p, DbTableCommon *tb, TreeDbTerm *root, Eterm key,
+                       Eterm *ret, DbTableTree *stack_container);
+int db_get_element_tree_common(Process *p, DbTableCommon *tb, TreeDbTerm *root, Eterm key,
+                               int ndex, Eterm *ret, DbTableTree *stack_container);
+int db_member_tree_common(DbTableCommon *tb, TreeDbTerm *root, Eterm key, Eterm *ret,
+                          DbTableTree *stack_container);
+int db_erase_tree_common(DbTable *tbl, TreeDbTerm **root, Eterm key, Eterm *ret,
+                         DbTreeStack *stack /* NULL if no static stack */);
+int db_erase_object_tree_common(DbTable *tbl, TreeDbTerm **root, Eterm object,
+                                Eterm *ret, DbTableTree *stack_container);
+int db_slot_tree_common(Process *p, DbTable *tbl, TreeDbTerm *root,
+                        Eterm slot_term, Eterm *ret,
+                        DbTableTree *stack_container,
+                        CATreeRootIterator*);
+int db_select_chunk_tree_common(Process *p, DbTable *tb,
+                                Eterm tid, Eterm pattern, Sint chunk_size,
+                                int reverse, Eterm *ret,
+                                DbTableTree *stack_container,
+                                CATreeRootIterator*);
+int db_select_tree_common(Process *p, DbTable *tb,
+                          Eterm tid, Eterm pattern, int reverse, Eterm *ret,
+                          DbTableTree *stack_container,
+                          CATreeRootIterator*);
+int db_select_delete_tree_common(Process *p, DbTable *tbl,
+                                 Eterm tid, Eterm pattern,
+                                 Eterm *ret,
+                                 DbTreeStack* stack,
+                                 CATreeRootIterator* iter);
+int db_select_continue_tree_common(Process *p, 
+                                   DbTableCommon *tb,
+                                   Eterm continuation,
+                                   Eterm *ret,
+                                   DbTableTree *stack_container,
+                                   CATreeRootIterator* iter);
+int db_select_delete_continue_tree_common(Process *p, 
+                                          DbTable *tbl,
+                                          Eterm continuation,
+                                          Eterm *ret,
+                                          DbTreeStack* stack,
+                                          CATreeRootIterator* iter);
+int db_select_count_tree_common(Process *p, DbTable *tb,
+                                Eterm tid, Eterm pattern, Eterm *ret,
+                                DbTableTree *stack_container,
+                                CATreeRootIterator* iter);
+int db_select_count_continue_tree_common(Process *p,
+                                         DbTable *tb,
+                                         Eterm continuation,
+                                         Eterm *ret,
+                                         DbTableTree *stack_container,
+                                         CATreeRootIterator* iter);
+int db_select_replace_tree_common(Process *p, DbTable*,
+                                  Eterm tid, Eterm pattern, Eterm *ret,
+                                  DbTableTree *stack_container,
+                                  CATreeRootIterator* iter);
+int db_select_replace_continue_tree_common(Process *p,
+                                           DbTable*,
+                                           Eterm continuation,
+                                           Eterm *ret,
+                                           DbTableTree *stack_container,
+                                           CATreeRootIterator* iter);
+int db_take_tree_common(Process *p, DbTable *tbl, TreeDbTerm **root,
+                        Eterm key, Eterm *ret,
+                        DbTreeStack *stack /* NULL if no static stack */);
+void db_print_tree_common(fmtfn_t to, void *to_arg,
+                          int show, TreeDbTerm *root, DbTable *tbl);
+void db_foreach_offheap_tree_common(TreeDbTerm *root,
+                                    void (*func)(ErlOffHeap *, void *),
+                                    void * arg);
+int db_lookup_dbterm_tree_common(Process *p, DbTable *tbl, TreeDbTerm **root,
+                                 Eterm key, Eterm obj, DbUpdateHandle* handle,
+                                 DbTableTree *stack_container);
+void db_finalize_dbterm_tree_common(int cret, DbUpdateHandle *handle,
+                                    DbTableTree *stack_container);
+Sint cmp_partly_bound(Eterm partly_bound_key, Eterm bound_key);
+
+#endif /* _DB_TREE_UTIL_H */
diff --git a/erts/emulator/beam/erl_db_util.c b/erts/emulator/beam/erl_db_util.c
index f1d47326b4..1ea7074d21 100644
--- a/erts/emulator/beam/erl_db_util.c
+++ b/erts/emulator/beam/erl_db_util.c
@@ -497,6 +497,7 @@ static erts_atomic32_t trace_control_word;
 /* This needs to be here, before the bif table... */
 
 static Eterm db_set_trace_control_word_fake_1(BIF_ALIST_1);
+static Eterm db_length_1(BIF_ALIST_1);
 
 /*
 ** The table of callable bif's, i e guard bif's and 
@@ -603,7 +604,7 @@ static DMCGuardBif guard_tab[] =
     },
     {
 	am_length,
-	&length_1,
+	&db_length_1,
 	1,
 	DBIF_ALL
     },
@@ -971,6 +972,26 @@ BIF_RETTYPE db_set_trace_control_word_1(BIF_ALIST_1)
     BIF_RET(db_set_trace_control_word(BIF_P, BIF_ARG_1));
 }
 
+/*
+ * Implementation of length/1 for match specs (non-trapping).
+ */
+static Eterm db_length_1(BIF_ALIST_1)
+{
+    Eterm list;
+    Uint i;
+
+    list = BIF_ARG_1;
+    i = 0;
+    while (is_list(list)) {
+	i++;
+	list = CDR(list_val(list));
+    }
+    if (is_not_nil(list)) {
+	BIF_ERROR(BIF_P, BADARG);
+    }
+    BIF_RET(make_small(i));
+}
+
 static Eterm db_set_trace_control_word_fake_1(BIF_ALIST_1)
 {
     Process *p = BIF_P;
@@ -2470,7 +2491,7 @@ restart:
 	case matchProcessDump: {
 	    erts_dsprintf_buf_t *dsbufp = erts_create_tmp_dsbuf(0);
             ASSERT(c_p == self);
-	    print_process_info(ERTS_PRINT_DSBUF, (void *) dsbufp, c_p);
+	    print_process_info(ERTS_PRINT_DSBUF, (void *) dsbufp, c_p, ERTS_PROC_LOCK_MAIN);
 	    *esp++ = new_binary(build_proc, (byte *)dsbufp->str,
 				dsbufp->str_len);
 	    erts_destroy_tmp_dsbuf(dsbufp);
@@ -3118,9 +3139,7 @@ void* db_store_term_comp(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj)
     Uint new_sz = offset + db_size_dbterm_comp(tb, obj);
     byte* basep;
     DbTerm* newp;
-#ifdef DEBUG
     byte* top;
-#endif
 
     ASSERT(tb->compress);
     if (old != 0) {
@@ -3142,11 +3161,8 @@ void* db_store_term_comp(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj)
     }
 
     newp->size = size_object(obj);
-#ifdef DEBUG
-    top = 
-#endif
-	copy_to_comp(tb, obj, newp, new_sz);
-    ASSERT(top <= basep + new_sz);
+    top = copy_to_comp(tb, obj, newp, new_sz);
+    ASSERT(top <= basep + new_sz); (void)top;
 
     /* ToDo: Maybe realloc if ((basep+new_sz) - top) > WASTED_SPACE_LIMIT */
 
@@ -3296,7 +3312,7 @@ void db_cleanup_offheap_comp(DbTerm* obj)
 	default:
 	    ASSERT(is_external_header(u.hdr->thing_word));
 	    ASSERT(u.pb != &tmp);
-	    erts_deref_node_entry(u.ext->node);
+	    erts_deref_node_entry(u.ext->node, make_boxed(u.ep));
 	    break;
 	}
     }
diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h
index 6ec3b4f98f..02d4dd6c9a 100644
--- a/erts/emulator/beam/erl_db_util.h
+++ b/erts/emulator/beam/erl_db_util.h
@@ -21,6 +21,7 @@
 #ifndef _DB_UTIL_H
 #define _DB_UTIL_H
 
+#include "erl_flxctr.h"
 #include "global.h"
 #include "erl_message.h"
 #include "erl_bif_unique.h"
@@ -89,9 +90,26 @@ typedef struct {
     void** bp;         /* {Hash|Tree}DbTerm** */
     Uint new_size;
     int flags;
-    void* lck;
+    union {
+        struct {
+            erts_rwmtx_t* lck;
+        } hash;
+        struct {
+            struct DbTableCATreeNode* base_node;
+            struct DbTableCATreeNode* parent;
+            int current_level;
+        } catree;
+    } u;
 } DbUpdateHandle;
 
+/* How safe are we from double-hits or missed objects
+ * when iterating without fixation?
+ */
+enum DbIterSafety {
+    ITER_UNSAFE,      /* Must fixate to be safe */
+    ITER_SAFE_LOCKED, /* Safe while table is locked, not between trap calls */
+    ITER_SAFE         /* No need to fixate at all */
+};
 
 typedef struct db_table_method
 {
@@ -141,48 +159,61 @@ typedef struct db_table_method
 			   Eterm pattern,
 			   Sint chunk_size,
 			   int reverse,
-			   Eterm* ret);
+			   Eterm* ret,
+                           enum DbIterSafety);
     int (*db_select)(Process* p, 
 		     DbTable* tb, /* [in out] */
                      Eterm tid,
 		     Eterm pattern,
 		     int reverse,
-		     Eterm* ret);
+		     Eterm* ret,
+                     enum DbIterSafety);
     int (*db_select_delete)(Process* p, 
 			    DbTable* tb, /* [in out] */
                             Eterm tid,
 			    Eterm pattern,
-			    Eterm* ret);
+			    Eterm* ret,
+                            enum DbIterSafety);
     int (*db_select_continue)(Process* p, 
 			      DbTable* tb, /* [in out] */
 			      Eterm continuation,
-			      Eterm* ret);
+			      Eterm* ret,
+                              enum DbIterSafety*);
     int (*db_select_delete_continue)(Process* p, 
 				     DbTable* tb, /* [in out] */
 				     Eterm continuation,
-				     Eterm* ret);
+				     Eterm* ret,
+                                     enum DbIterSafety*);
     int (*db_select_count)(Process* p, 
 			   DbTable* tb, /* [in out] */
                            Eterm tid,
 			   Eterm pattern, 
-			   Eterm* ret);
+			   Eterm* ret,
+                           enum DbIterSafety);
     int (*db_select_count_continue)(Process* p, 
 				    DbTable* tb, /* [in out] */ 
 				    Eterm continuation, 
-				    Eterm* ret);
+				    Eterm* ret,
+                                    enum DbIterSafety*);
     int (*db_select_replace)(Process* p,
             DbTable* tb, /* [in out] */
             Eterm tid,
             Eterm pattern,
-            Eterm* ret);
+            Eterm* ret,
+            enum DbIterSafety);
     int (*db_select_replace_continue)(Process* p,
             DbTable* tb, /* [in out] */
             Eterm continuation,
-            Eterm* ret);
+            Eterm* ret,
+            enum DbIterSafety*);
     int (*db_take)(Process *, DbTable *, Eterm, Eterm *);
 
-    SWord (*db_delete_all_objects)(Process* p, DbTable* db, SWord reds);
-
+    SWord (*db_delete_all_objects)(Process* p,
+                                   DbTable* db,
+                                   SWord reds,
+                                   Eterm* nitems_holder_wb);
+    Eterm (*db_delete_all_objects_get_nitems_from_holder)(Process* p,
+                                                          Eterm nitems_holder);
     int (*db_free_empty_table)(DbTable* db);
     SWord (*db_free_table_continue)(DbTable* db, SWord reds);
     
@@ -231,6 +262,9 @@ typedef struct {
     DbTable *prev;
 } DbTableList;
 
+#define ERTS_DB_TABLE_NITEMS_COUNTER_ID 0
+#define ERTS_DB_TABLE_MEM_COUNTER_ID 1
+
 /*
  * This structure contains data for all different types of database
  * tables. Note that these fields must match the same fields
@@ -255,8 +289,11 @@ typedef struct db_table_common {
     Eterm the_name;           /* an atom */
     Binary *btid;
     DbTableMethod* meth;      /* table methods */
-    erts_atomic_t nitems; /* Total number of items in table */
-    erts_atomic_t memory_size;/* Total memory size. NOTE: in bytes! */
+    /* The ErtsFlxCtr below contains:
+     * - Total number of items in table
+     * - Total memory size (NOTE: in bytes!) */
+    ErtsFlxCtr counters;
+    char extra_for_flxctr[ERTS_FLXCTR_NR_OF_EXTRA_BYTES(2)];
     struct {                  /* Last fixation time */
 	ErtsMonotonicTime monotonic;
 	ErtsMonotonicTime offset;
@@ -274,23 +311,29 @@ typedef struct db_table_common {
 } DbTableCommon;
 
 /* These are status bit patterns */
-#define DB_PRIVATE       (1 << 0)
-#define DB_PROTECTED     (1 << 1)
-#define DB_PUBLIC        (1 << 2)
-#define DB_DELETE        (1 << 3) /* table is being deleted */
-#define DB_SET           (1 << 4)
-#define DB_BAG           (1 << 5)
-#define DB_DUPLICATE_BAG (1 << 6)
-#define DB_ORDERED_SET   (1 << 7)
-#define DB_FINE_LOCKED   (1 << 8) /* write_concurrency */
-#define DB_FREQ_READ     (1 << 9) /* read_concurrency */
-#define DB_NAMED_TABLE   (1 << 10)
-#define DB_BUSY          (1 << 11)
+#define DB_PRIVATE        (1 << 0)
+#define DB_PROTECTED      (1 << 1)
+#define DB_PUBLIC         (1 << 2)
+#define DB_DELETE         (1 << 3) /* table is being deleted */
+#define DB_SET            (1 << 4)
+#define DB_BAG            (1 << 5)
+#define DB_DUPLICATE_BAG  (1 << 6)
+#define DB_ORDERED_SET    (1 << 7)
+#define DB_CA_ORDERED_SET (1 << 8)
+#define DB_FINE_LOCKED    (1 << 9)  /* write_concurrency */
+#define DB_FREQ_READ      (1 << 10) /* read_concurrency */
+#define DB_NAMED_TABLE    (1 << 11)
+#define DB_BUSY           (1 << 12)
+
+#define DB_CATREE_FORCE_SPLIT (1 << 31)  /* erts_debug */
+#define DB_CATREE_DEBUG_RANDOM_SPLIT_JOIN (1 << 30)  /* erts_debug */
 
 #define IS_HASH_TABLE(Status) (!!((Status) & \
 				  (DB_BAG | DB_SET | DB_DUPLICATE_BAG)))
 #define IS_TREE_TABLE(Status) (!!((Status) & \
 				  DB_ORDERED_SET))
+#define IS_CATREE_TABLE(Status) (!!((Status) & \
+                                    DB_CA_ORDERED_SET))
 #define NFIXED(T) (erts_refc_read(&(T)->common.fix_count,0))
 #define IS_FIXED(T) (NFIXED(T) != 0) 
 
diff --git a/erts/emulator/beam/erl_dirty_bif.tab b/erts/emulator/beam/erl_dirty_bif.tab
index 20299ff604..656acfebdb 100644
--- a/erts/emulator/beam/erl_dirty_bif.tab
+++ b/erts/emulator/beam/erl_dirty_bif.tab
@@ -57,9 +57,6 @@ dirty-cpu erts_debug:lcnt_clear/0
 #  and debug purposes only. We really do *not* want to execute these
 #  on dirty schedulers on a real system.
 
-dirty-cpu-test erlang:'++'/2
-dirty-cpu-test erlang:append/2
-dirty-cpu-test erlang:iolist_size/1
 dirty-cpu-test erlang:make_tuple/2
 dirty-cpu-test erlang:make_tuple/3
 dirty-cpu-test erlang:append_element/2
diff --git a/erts/emulator/beam/erl_drv_nif.h b/erts/emulator/beam/erl_drv_nif.h
index 31b4817fb1..a5ecbfff06 100644
--- a/erts/emulator/beam/erl_drv_nif.h
+++ b/erts/emulator/beam/erl_drv_nif.h
@@ -53,7 +53,9 @@ typedef enum {
 enum ErlNifSelectFlags {
     ERL_NIF_SELECT_READ      = (1 << 0),
     ERL_NIF_SELECT_WRITE     = (1 << 1),
-    ERL_NIF_SELECT_STOP      = (1 << 2)
+    ERL_NIF_SELECT_STOP      = (1 << 2),
+    ERL_NIF_SELECT_CANCEL    = (1 << 3),
+    ERL_NIF_SELECT_CUSTOM_MSG= (1 << 4)
 };
 
 /*
diff --git a/erts/emulator/beam/erl_flxctr.c b/erts/emulator/beam/erl_flxctr.c
new file mode 100644
index 0000000000..35f4a21508
--- /dev/null
+++ b/erts/emulator/beam/erl_flxctr.c
@@ -0,0 +1,370 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+/*
+ * Author: Kjell Winblad
+ */
+
+#include "erl_flxctr.h"
+
+static int reader_groups_array_size = 0;
+#define ERTS_FLXCTR_DECENTRALIZED_NO_SLOTS (reader_groups_array_size)
+
+static int erts_flxctr_read_ctx_bin_dtor(Binary *context_bin);
+static int erts_flxctr_wait_dtor(Binary *context_bin);
+
+typedef struct {
+    ErtsThrPrgrLaterOp later_op;
+    Process* process;
+    ErtsFlxCtrDecentralizedCtrArray* array;
+    ErtsFlxCtrDecentralizedCtrArray* next_array;
+    ErtsAlcType_t alloc_type;
+    int nr_of_counters;
+    Sint result[ERTS_FLXCTR_ATOMICS_PER_CACHE_LINE];
+} DecentralizedReadSnapshotInfo;
+
+typedef enum {
+    ERTS_FLXCTR_SNAPSHOT_NOT_ONGOING = 0,
+    ERTS_FLXCTR_SNAPSHOT_ONGOING = 1,
+    ERTS_FLXCTR_SNAPSHOT_ONGOING_TP_THREAD_DO_FREE = 2
+} erts_flxctr_snapshot_status;
+
+static void
+thr_prg_wake_up_and_count(void* bin_p)
+{
+    Binary* bin = bin_p;
+    DecentralizedReadSnapshotInfo* info = ERTS_MAGIC_BIN_DATA(bin);
+    Process* p = info->process;
+    ErtsFlxCtrDecentralizedCtrArray* array = info->array;
+    ErtsFlxCtrDecentralizedCtrArray* next = info->next_array;
+    int i, sched;
+    /* Reset result array */
+    for (i = 0; i < info->nr_of_counters; i++) {
+        info->result[i] = 0;
+    }
+    /* Read result from snapshot */
+    for (sched = 0; sched < ERTS_FLXCTR_DECENTRALIZED_NO_SLOTS; sched++) {
+        for (i = 0; i < info->nr_of_counters; i++) {
+            info->result[i] = info->result[i] +
+                erts_atomic_read_nob(&array->array[sched].counters[i]);
+        }
+    }
+    /* Update the next decentralized counter array */
+    for (i = 0; i < info->nr_of_counters; i++) {
+        erts_atomic_add_nob(&next->array[0].counters[i], info->result[i]);
+    }
+    /* Announce that the snapshot is done */
+    {
+    Sint expected = ERTS_FLXCTR_SNAPSHOT_ONGOING;
+    if (expected != erts_atomic_cmpxchg_mb(&next->snapshot_status,
+                                           ERTS_FLXCTR_SNAPSHOT_NOT_ONGOING,
+                                           expected)) {
+        /* The CAS failed which means that this thread need to free the next array. */
+        erts_free(info->alloc_type, next->block_start);
+    }
+    }
+    /* Resume the process that requested the snapshot */
+    erts_proc_lock(p, ERTS_PROC_LOCK_STATUS);
+    if (!ERTS_PROC_IS_EXITING(p)) {
+        erts_resume(p, ERTS_PROC_LOCK_STATUS);
+    }
+    /* Free the memory that is no longer needed */
+    erts_free(info->alloc_type, array->block_start);
+    erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
+    erts_proc_dec_refc(p);
+    erts_bin_release(bin);
+}
+
+typedef struct {
+    ErtsThrPrgrLaterOp later_op;
+    Process* process;
+} ErtsFlxCtrWakeUpLaterInfo;
+
+static void
+thr_prg_wake_up_later(void* bin_p)
+{
+    Binary* bin = bin_p;
+    ErtsFlxCtrWakeUpLaterInfo* info = ERTS_MAGIC_BIN_DATA(bin);
+    Process* p = info->process;
+    /* Resume the requesting process */
+    erts_proc_lock(p, ERTS_PROC_LOCK_STATUS);
+    if (!ERTS_PROC_IS_EXITING(p)) {
+        erts_resume(p, ERTS_PROC_LOCK_STATUS);
+    }
+    erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
+    /* Free data */
+    erts_proc_dec_refc(p);
+    erts_bin_release(bin);
+}
+
+static
+int erts_flxctr_read_ctx_bin_dtor(Binary *context_bin) {
+    (void)context_bin;
+    return 1;
+}
+
+static
+int erts_flxctr_wait_dtor(Binary *context_bin) {
+    (void)context_bin;
+    return 1;
+}
+
+static void suspend_until_thr_prg(Process* p)
+{
+    Binary* state_bin;
+    ErtsFlxCtrWakeUpLaterInfo* info;
+    state_bin = erts_create_magic_binary(sizeof(ErtsFlxCtrWakeUpLaterInfo),
+                                         erts_flxctr_wait_dtor);
+    info = ERTS_MAGIC_BIN_DATA(state_bin);
+    info->process = p;
+    erts_refc_inctest(&state_bin->intern.refc, 1);
+    erts_suspend(p, ERTS_PROC_LOCK_MAIN, NULL);
+    erts_proc_inc_refc(p);
+    ERTS_VBUMP_ALL_REDS(p);
+    erts_schedule_thr_prgr_later_op(thr_prg_wake_up_later, state_bin, &info->later_op);
+}
+
+
+static ErtsFlxCtrDecentralizedCtrArray*
+create_decentralized_ctr_array(ErtsAlcType_t alloc_type, Uint nr_of_counters) {
+    /* Allocate an ErtsFlxCtrDecentralizedCtrArray and make sure that
+       the array field is located at the start of a cache line */
+    char* bytes =
+        erts_alloc(alloc_type,
+                   sizeof(ErtsFlxCtrDecentralizedCtrArray) +
+                   (sizeof(ErtsFlxCtrDecentralizedCtrArrayElem) *
+                    ERTS_FLXCTR_DECENTRALIZED_NO_SLOTS) +
+                   ERTS_CACHE_LINE_SIZE);
+    void* block_start = bytes;
+    int bytes_to_next_cacheline_border;
+    ErtsFlxCtrDecentralizedCtrArray* array;
+    int i, sched;
+    bytes = &bytes[offsetof(ErtsFlxCtrDecentralizedCtrArray, array)];
+    bytes_to_next_cacheline_border =
+        ERTS_CACHE_LINE_SIZE - (((Uint)bytes) % ERTS_CACHE_LINE_SIZE);
+    array = (ErtsFlxCtrDecentralizedCtrArray*)
+        (&bytes[bytes_to_next_cacheline_border -
+                (int)offsetof(ErtsFlxCtrDecentralizedCtrArray, array)]);
+    ASSERT(((Uint)array->array) % ERTS_CACHE_LINE_SIZE == 0);
+    ASSERT(((Uint)array - (Uint)block_start) <= ERTS_CACHE_LINE_SIZE);
+    /* Initialize fields */
+    erts_atomic_init_nob(&array->snapshot_status, ERTS_FLXCTR_SNAPSHOT_ONGOING);
+    for (sched = 0; sched < ERTS_FLXCTR_DECENTRALIZED_NO_SLOTS; sched++) {
+        for (i = 0; i < nr_of_counters; i++) {
+            erts_atomic_init_nob(&array->array[sched].counters[i], 0);
+        }
+    }
+    array->block_start = block_start;
+    return array;
+}
+
+void erts_flxctr_setup(int decentralized_counter_groups)
+{
+    reader_groups_array_size = decentralized_counter_groups+1;
+}
+
+void erts_flxctr_init(ErtsFlxCtr* c,
+                      int is_decentralized,
+                      Uint nr_of_counters,
+                      ErtsAlcType_t alloc_type)
+{
+    ASSERT(nr_of_counters <= ERTS_FLXCTR_ATOMICS_PER_CACHE_LINE);
+    c->is_decentralized = is_decentralized;
+    c->nr_of_counters = nr_of_counters;
+    if (c->is_decentralized) {
+        ErtsFlxCtrDecentralizedCtrArray* array =
+            create_decentralized_ctr_array(alloc_type, nr_of_counters);
+        erts_atomic_set_nob(&array->snapshot_status,
+                            ERTS_FLXCTR_SNAPSHOT_NOT_ONGOING);
+        erts_atomic_init_nob(&c->u.counters_ptr, (Sint)array);
+        ASSERT(((Uint)array->array) % ERTS_CACHE_LINE_SIZE == 0);
+    } else {
+        int i;
+        for (i = 0; i < nr_of_counters; i++) {
+            erts_atomic_init_nob(&c->u.counters[i], 0);
+        }
+    }
+}
+
+void erts_flxctr_destroy(ErtsFlxCtr* c, ErtsAlcType_t type)
+{
+    if (c->is_decentralized) {
+        if (erts_flxctr_is_snapshot_ongoing(c)) {
+            ErtsFlxCtrDecentralizedCtrArray* array =
+                ERTS_FLXCTR_GET_CTR_ARRAY_PTR(c);
+            /* Try to delegate the resposibilty of freeing to
+               thr_prg_wake_up_and_count */
+            Sint expected = ERTS_FLXCTR_SNAPSHOT_ONGOING;
+            if (expected !=
+                erts_atomic_cmpxchg_mb(&array->snapshot_status,
+                                       ERTS_FLXCTR_SNAPSHOT_ONGOING_TP_THREAD_DO_FREE,
+                                       expected)) {
+                /* The delegation was unsuccessful which means that no
+                   snapshot is ongoing anymore and the freeing needs
+                   to be done here */
+                ERTS_ASSERT(!erts_flxctr_is_snapshot_ongoing(c));
+                erts_free(type, array->block_start);
+            }
+        } else {
+            erts_free(type, ERTS_FLXCTR_GET_CTR_ARRAY_PTR(c)->block_start);
+        }
+    }
+}
+
+ErtsFlxCtrSnapshotResult
+erts_flxctr_snapshot(ErtsFlxCtr* c,
+                     ErtsAlcType_t alloc_type,
+                     Process* p)
+{
+    if (c->is_decentralized) {
+        ErtsFlxCtrDecentralizedCtrArray* array = ERTS_FLXCTR_GET_CTR_ARRAY_PTR(c);
+        if (erts_flxctr_is_snapshot_ongoing(c)) {
+            /* Let the caller try again later */
+            ErtsFlxCtrSnapshotResult res =
+                {.type = ERTS_FLXCTR_TRY_AGAIN_AFTER_TRAP};
+            suspend_until_thr_prg(p);
+            return res;
+        } else {
+            Eterm* hp;
+            Binary* state_bin;
+            Eterm state_mref;
+            DecentralizedReadSnapshotInfo* info;
+            ErtsFlxCtrDecentralizedCtrArray* new_array =
+                create_decentralized_ctr_array(alloc_type, c->nr_of_counters);
+            int success =
+                ((Sint)array) == erts_atomic_cmpxchg_mb(&c->u.counters_ptr,
+                                                        (Sint)new_array,
+                                                        (Sint)array);
+            if (!success) {
+                /* Let the caller try again later */
+                ErtsFlxCtrSnapshotResult res =
+                    {.type = ERTS_FLXCTR_TRY_AGAIN_AFTER_TRAP};
+                suspend_until_thr_prg(p);
+                erts_free(alloc_type, new_array->block_start);
+                return res;
+            }
+            /* Create binary with info about the operation that can be
+               sent to the caller and to a thread progress function */
+            state_bin =
+                erts_create_magic_binary(sizeof(DecentralizedReadSnapshotInfo),
+                                         erts_flxctr_read_ctx_bin_dtor);
+            hp = HAlloc(p, ERTS_MAGIC_REF_THING_SIZE);
+            state_mref = erts_mk_magic_ref(&hp, &MSO(p), state_bin);
+            info = ERTS_MAGIC_BIN_DATA(state_bin);
+            info->alloc_type = alloc_type;
+            info->array = array;
+            info->next_array = new_array;
+            info->process = p;
+            info->nr_of_counters = c->nr_of_counters;
+            erts_proc_inc_refc(p);
+            erts_refc_inctest(&state_bin->intern.refc, 2);
+            erts_suspend(p, ERTS_PROC_LOCK_MAIN, NULL);
+            ERTS_VBUMP_ALL_REDS(p);
+            erts_schedule_thr_prgr_later_op(thr_prg_wake_up_and_count,
+                                            state_bin,
+                                            &info->later_op);
+            {
+                ErtsFlxCtrSnapshotResult res = {
+                    .type = ERTS_FLXCTR_GET_RESULT_AFTER_TRAP,
+                    .trap_resume_state = state_mref};
+                return res;
+            }
+        }
+    } else {
+        ErtsFlxCtrSnapshotResult res;
+        int i;
+        res.type = ERTS_FLXCTR_DONE;
+        for (i = 0; i < c->nr_of_counters; i++){
+            res.result[i] = erts_flxctr_read_centralized(c, i);
+        }
+        return res;
+    }
+}
+
+
+Sint erts_flxctr_get_snapshot_result_after_trap(Eterm result_holder,
+                                            Uint counter_nr)
+{
+    Binary* bin = erts_magic_ref2bin(result_holder);
+    DecentralizedReadSnapshotInfo* data = ERTS_MAGIC_BIN_DATA(bin);;
+    return data->result[counter_nr];
+}
+
+int erts_flxctr_is_snapshot_result(Eterm term)
+{
+    if (is_internal_magic_ref(term)) {
+        Binary* bin = erts_magic_ref2bin(term);
+        return ERTS_MAGIC_BIN_DESTRUCTOR(bin) ==  erts_flxctr_read_ctx_bin_dtor;
+    } else return 0;
+}
+
+Sint erts_flxctr_read_approx(ErtsFlxCtr* c,
+                             Uint counter_nr)
+{
+    if (c->is_decentralized) {
+        ErtsFlxCtrDecentralizedCtrArray* counter = ERTS_FLXCTR_GET_CTR_ARRAY_PTR(c);
+        Sint sum = 0;
+        int sched;
+        for (sched = 0; sched < ERTS_FLXCTR_DECENTRALIZED_NO_SLOTS; sched++) {
+            sum = sum + erts_atomic_read_nob(&counter->array[sched].counters[counter_nr]);
+        }
+        return sum;
+    } else {
+        return erts_flxctr_read_centralized(c, counter_nr);
+    }
+}
+
+int erts_flxctr_is_snapshot_ongoing(ErtsFlxCtr* c)
+{
+    return c->is_decentralized &&
+        (ERTS_FLXCTR_SNAPSHOT_NOT_ONGOING !=
+         erts_atomic_read_acqb(&ERTS_FLXCTR_GET_CTR_ARRAY_PTR(c)->snapshot_status));
+}
+
+int erts_flxctr_suspend_until_thr_prg_if_snapshot_ongoing(ErtsFlxCtr* c, Process* p)
+{
+    if (erts_flxctr_is_snapshot_ongoing(c)) {
+        suspend_until_thr_prg(p);
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+void erts_flxctr_reset(ErtsFlxCtr* c,
+                       Uint counter_nr)
+{
+    if (c->is_decentralized) {
+        int sched;
+        ErtsFlxCtrDecentralizedCtrArray* counter =
+            ERTS_FLXCTR_GET_CTR_ARRAY_PTR(c);
+        for (sched = 0; sched < ERTS_FLXCTR_DECENTRALIZED_NO_SLOTS; sched++) {
+            erts_atomic_set_nob(&counter->array[sched].counters[counter_nr], 0);
+        }
+    } else {
+        erts_atomic_set_nob(&c->u.counters[counter_nr], 0);
+    }
+}
+
+
+void erts_flxctr_set_slot(int group) {
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    esdp->flxctr_slot_no = group;
+}
diff --git a/erts/emulator/beam/erl_flxctr.h b/erts/emulator/beam/erl_flxctr.h
new file mode 100644
index 0000000000..5cab02b9eb
--- /dev/null
+++ b/erts/emulator/beam/erl_flxctr.h
@@ -0,0 +1,406 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+/**
+ * @file erl_flxctr.h
+ *
+ * @brief This file contains the API of a flexible counter. The
+ * counter can be configured during its initialization to be
+ * centralized or decentralized. The centralized configuration makes
+ * it possible to read the counter value extremely efficiently, but
+ * updates of the counter value can easily cause contention. The
+ * decentralized configuration has the reverse trade-off (i.e.,
+ * updates are efficient and scalable but reading the counter value is
+ * slow and may cause contention).
+ *
+ * @author Kjell Winblad
+ */
+
+#ifndef ERL_FLXCTR_H__
+#define ERL_FLXCTR_H__
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+#include "sys.h"
+#include "erl_vm.h"
+#include "global.h"
+#include "error.h"
+#include "bif.h"
+#include "big.h"
+#include "erl_binary.h"
+#include "bif.h"
+#include <stddef.h>
+
+/* Public Interface */
+
+#define ERTS_MAX_FLXCTR_GROUPS 256
+#define ERTS_FLXCTR_ATOMICS_PER_CACHE_LINE (ERTS_CACHE_LINE_SIZE / sizeof(erts_atomic_t))
+
+typedef struct {
+    int nr_of_counters;
+    int is_decentralized;
+    union {
+        erts_atomic_t counters_ptr;
+        erts_atomic_t counters[1];
+    } u;
+} ErtsFlxCtr;
+
+#define ERTS_FLXCTR_NR_OF_EXTRA_BYTES(NR_OF_COUNTERS)   \
+    ((NR_OF_COUNTERS-1) * sizeof(erts_atomic_t))
+
+/* Called by early_init */
+void erts_flxctr_setup(int decentralized_counter_groups);
+
+/**
+ * @brief Initializes an ErtsFlxCtr. The macro
+ * ERTS_FLXCTR_NR_OF_EXTRA_BYTES should be used to determine how much
+ * extra space that needs to be allocated directly after the
+ * ErtsFlxCtr when is_decentralized is set to zero.  Each ErtsFlxCtr
+ * instance may contain up to ERTS_FLXCTR_ATOMICS_PER_CACHE_LINE
+ * counters. These counters are numbered from zero to
+ * (ERTS_FLXCTR_ATOMICS_PER_CACHE_LINE-1). Most of the functions in
+ * this module take a parameter named counter_nr that controls which
+ * of the ERTS_FLXCTR_ATOMICS_PER_CACHE_LINE counters in the given
+ * ErtsFlxCtr that should be operated on.
+ *
+ * @param c The counter to initialize
+ * @param is_decentralized Non-zero value to make c decentralized
+ * @param nr_of_counters The number of counters included in c
+ *                       (max ERTS_FLXCTR_ATOMICS_PER_CACHE_LINE)
+ * @param alloc_type 
+ */
+void erts_flxctr_init(ErtsFlxCtr* c,
+                      int is_decentralized,
+                      Uint nr_of_counters,
+                      ErtsAlcType_t alloc_type);
+
+/**
+ * @brief Destroys an initialized counter.
+ *
+ * @param c The counter that should be destroyed
+ * @param alloc_type The allocation type (needs to be the same as the
+ *                   one passed to erts_flxctr_init when c was
+ *                   initialized)
+ */
+void erts_flxctr_destroy(ErtsFlxCtr* c, ErtsAlcType_t alloc_type);
+
+/**
+ * @brief Adds to_add to the counter with counter_nr in c
+ *
+ * @param c the ErtsFlxCtr to operate on
+ * @param counter_nr The number of the counter in c to modify
+ * @param to_add The amount that should be added to the specified counter
+ */
+ERTS_GLB_INLINE
+void erts_flxctr_add(ErtsFlxCtr* c,
+                     Uint counter_nr,
+                     int to_add);
+
+/**
+ * @brief Increases the specified counter by 1
+ *
+ * @param c The ErtsFlxCtr instance to operate on
+ * @param counter_nr The number of the counter within c to operate on
+ */
+ERTS_GLB_INLINE
+void erts_flxctr_inc(ErtsFlxCtr* c,
+                     Uint counter_nr);
+
+/**
+ * @brief Decreases the specified counter by 1
+ */
+ERTS_GLB_INLINE
+void erts_flxctr_dec(ErtsFlxCtr* c,
+                     Uint counter_nr);
+
+/**
+ * @brief This function tries to return the current value of the
+ * specified counter but may return an incorrect result if the counter
+ * is decentralized and other threads are accessing the counter
+ * concurrently.
+ *
+ * @param c The ErtsFlxCtr instance to operate on
+ * @param counter_nr The number of the counter within c to operate on
+ *
+ * @return A snapshot of the specifed counter if c is centralized or a
+ *         possibly incorrect estimate of the counter value if c is
+ *         decentralized
+ */
+Sint erts_flxctr_read_approx(ErtsFlxCtr* c,
+                             Uint counter_nr);
+
+/**
+ * @brief This function can only be used together with an ErtsFlxCtr
+ * that is configured to be centralized. The function increments the
+ * specified counter by 1 and returns the value of the counter after
+ * the increment.
+ */
+ERTS_GLB_INLINE
+Sint erts_flxctr_inc_read_centralized(ErtsFlxCtr* c,
+                                      Uint counter_nr);
+
+/**
+ * @brief This function can only be used together with a ErtsFlxCtr
+ * that is configured to be centralized. The function decrements the
+ * specified counter by 1 and returns the value of the counter after
+ * the operation.
+ */
+ERTS_GLB_INLINE
+Sint erts_flxctr_dec_read_centralized(ErtsFlxCtr* c,
+                                      Uint counter_nr);
+
+/**
+ * @brief This function can only be used together with an ErtsFlxCtr
+ * that is configured to be centralized. The function returns the
+ * current value of the specified counter.
+ */
+ERTS_GLB_INLINE
+Sint erts_flxctr_read_centralized(ErtsFlxCtr* c,
+                                  Uint counter_nr);
+
+
+typedef enum {
+    ERTS_FLXCTR_TRY_AGAIN_AFTER_TRAP,
+    ERTS_FLXCTR_DONE,
+    ERTS_FLXCTR_GET_RESULT_AFTER_TRAP
+} ErtsFlxctrSnapshotResultType;
+
+typedef struct {
+    ErtsFlxctrSnapshotResultType type;
+    Eterm trap_resume_state;
+    Sint result[ERTS_FLXCTR_ATOMICS_PER_CACHE_LINE];
+} ErtsFlxCtrSnapshotResult;
+
+/**
+ * @brief This function initiates an atomic snapshot of an ErtsFlxCtr
+ * to read out the values of one or more of the counters that are
+ * stored in the given ErtsFlxCtr. The caller needs to perform
+ * different actions after the return of this function depending on
+ * the value of the type field in the returned struct:
+ *
+ * - The caller needs to trap and try again after the trap if the
+ *   return value has the type ERTS_FLXCTR_TRY_AGAIN_AFTER_TRAP.
+ *
+ * - The caller can get the result directly from the result field of
+ *   the returned struct if the return value has the type
+ *   ERTS_FLXCTR_DONE. The value at index i in the result field
+ *   correspond to counter number i.
+ *
+ * - Finally, if the return value has the type
+ *   ERTS_FLXCTR_GET_RESULT_AFTER_TRAP, then the caller needs to save
+ *   the value of the field trap_resume_state from the returned struct
+ *   and trap. After the trap, the values of the counters can be
+ *   obtained by using the function
+ *   erts_flxctr_get_snapshot_result_after_trap. Note that the
+ *   function erts_flxctr_is_snapshot_result can be used to check if a
+ *   value is obtained from the trap_resume_state field in the
+ *   returned struct (this can be useful when the calling function
+ *   wakes up again after the trap).
+ *
+ * The snapshot operation that is initiated by this function should be
+ * considered to be ongoing from the issuing of this function until a
+ * struct with the type field set to ERTS_FLXCTR_DONE has been
+ * returned from the function or until the caller of this function has
+ * woken up after trapping.
+ *
+ * @param c The ErtsFlxCtr that the snapshot shall be taken from
+ * @param alloc_type The allocation type (needs to be the same as the
+ *                   type passed to erts_flxctr_init when c was
+ *                   initialized)
+ * @param p The Erlang process that is doing the call
+ *
+ * @return See the description above
+ *
+ */
+ErtsFlxCtrSnapshotResult
+erts_flxctr_snapshot(ErtsFlxCtr* c,
+                     ErtsAlcType_t alloc_type,
+                     Process* p);
+
+/**
+ * @brief Checks if the parameter term is a snapshot result (i.e.,
+ * something obtained from the trap_resume_state field of an
+ * ErtsFlxCtrSnapshotResult struct that has been returned from
+ * erts_flxctr_snapshot).
+ *
+ * @param term The term to check 
+ *
+ * @return A nonzero value iff the term is a snapshot result
+ */
+int erts_flxctr_is_snapshot_result(Eterm term);
+
+/**
+ * @brief Returns the result of a snapshot for a counter given a
+ * snapshot result returned by a call to erts_flxctr_snapshot (i.e.,
+ * the value stored in the trap_resume_state field of a struct
+ * returned by erts_flxctr_snapshot). The caller needs to trap between
+ * the return of erts_flxctr_snapshot and the call to this function.
+ */
+Sint erts_flxctr_get_snapshot_result_after_trap(Eterm trap_resume_state,
+                                                Uint counter_nr);
+
+/**
+ * @brief Resets the specified counter to 0. This function is unsafe
+ * to call while a snapshot operation may be active (initiated with
+ * the erts_flxctr_snapshot function).
+ */
+void erts_flxctr_reset(ErtsFlxCtr* c,
+                       Uint counter_nr);
+
+/**
+ * @brief Checks if a snapshot operation is active (snapshots are
+ * initiated with the erts_flxctr_snapshot function).
+ *
+ * @return nonzero value iff a snapshot was active at some point
+ * between the invocation and return of the function
+ */
+int erts_flxctr_is_snapshot_ongoing(ErtsFlxCtr* c);
+
+/**
+ * @brief This function checks if a snapshot operation is ongoing
+ * (snapshots are initiated with the erts_flxctr_snapshot function)
+ * and suspend the given process until thread progress has happened if
+ * it detected an ongoing snapshot operation. The caller needs to trap
+ * if a non-zero value is returned.
+ *
+ * @param c The ErtsFlxCtr to check
+ * @param p The calling process
+ *
+ * @return nonzero value if the given process has got suspended
+ */
+int erts_flxctr_suspend_until_thr_prg_if_snapshot_ongoing(ErtsFlxCtr* c, Process* p);
+
+/* End: Public Interface */
+
+/* Internal Declarations */
+
+#define ERTS_FLXCTR_GET_CTR_ARRAY_PTR(C)                                \
+    ((ErtsFlxCtrDecentralizedCtrArray*) erts_atomic_read_acqb(&(C)->u.counters_ptr))
+#define ERTS_FLXCTR_GET_CTR_PTR(C, SCHEDULER_ID, COUNTER_ID)            \
+    &(ERTS_FLXCTR_GET_CTR_ARRAY_PTR(C))->array[SCHEDULER_ID].counters[COUNTER_ID]
+
+
+typedef union {
+    erts_atomic_t counters[ERTS_FLXCTR_ATOMICS_PER_CACHE_LINE];
+    char pad[ERTS_CACHE_LINE_SIZE];
+} ErtsFlxCtrDecentralizedCtrArrayElem;
+
+typedef struct ErtsFlxCtrDecentralizedCtrArray {
+    void* block_start;
+    erts_atomic_t snapshot_status;
+    ErtsFlxCtrDecentralizedCtrArrayElem array[];
+} ErtsFlxCtrDecentralizedCtrArray;
+
+void erts_flxctr_set_slot(int group);
+
+ERTS_GLB_INLINE
+int erts_flxctr_get_slot_index(void);
+
+/* End: Internal Declarations */
+
+
+/* Implementation of inlined functions */
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE
+int erts_flxctr_get_slot_index(void)
+{
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    ASSERT(esdp && !ERTS_SCHEDULER_IS_DIRTY(esdp));
+    ASSERT(esdp->flxctr_slot_no > 0);
+    return esdp->flxctr_slot_no;
+}
+
+ERTS_GLB_INLINE
+void erts_flxctr_add(ErtsFlxCtr* c,
+                     Uint counter_nr,
+                     int to_add)
+{
+    ASSERT(counter_nr < c->nr_of_counters);
+    if (c->is_decentralized) {
+        erts_atomic_add_nob(ERTS_FLXCTR_GET_CTR_PTR(c,
+                                                    erts_flxctr_get_slot_index(),
+                                                    counter_nr),
+                            to_add);
+    } else {
+        erts_atomic_add_nob(&c->u.counters[counter_nr], to_add);
+    }
+}
+
+ERTS_GLB_INLINE
+void erts_flxctr_inc(ErtsFlxCtr* c,
+                     Uint counter_nr)
+{
+    ASSERT(counter_nr < c->nr_of_counters);
+    if (c->is_decentralized) {
+        erts_atomic_inc_nob(ERTS_FLXCTR_GET_CTR_PTR(c,
+                                                    erts_flxctr_get_slot_index(),
+                                                    counter_nr));
+    } else {
+        erts_atomic_inc_read_nob(&c->u.counters[counter_nr]);
+    }
+}
+
+ERTS_GLB_INLINE
+void erts_flxctr_dec(ErtsFlxCtr* c,
+                     Uint counter_nr)
+{
+    ASSERT(counter_nr < c->nr_of_counters);
+    if (c->is_decentralized) {
+        erts_atomic_dec_nob(ERTS_FLXCTR_GET_CTR_PTR(c,
+                                                    erts_flxctr_get_slot_index(),
+                                                    counter_nr));
+    } else {
+        erts_atomic_dec_nob(&c->u.counters[counter_nr]);
+    }
+}
+
+ERTS_GLB_INLINE
+Sint erts_flxctr_inc_read_centralized(ErtsFlxCtr* c,
+                                      Uint counter_nr)
+{
+    ASSERT(counter_nr < c->nr_of_counters);
+    ASSERT(!c->is_decentralized);
+    return erts_atomic_inc_read_nob(&c->u.counters[counter_nr]);
+}
+
+ERTS_GLB_INLINE
+Sint erts_flxctr_dec_read_centralized(ErtsFlxCtr* c,
+                                      Uint counter_nr)
+{
+    ASSERT(counter_nr < c->nr_of_counters);
+    ASSERT(!c->is_decentralized);
+    return erts_atomic_dec_read_nob(&c->u.counters[counter_nr]);
+}
+
+ERTS_GLB_INLINE
+Sint erts_flxctr_read_centralized(ErtsFlxCtr* c,
+                                  Uint counter_nr)
+{
+    ASSERT(counter_nr < c->nr_of_counters);
+    ASSERT(!c->is_decentralized);   
+    return erts_atomic_read_nob(&((erts_atomic_t*)(c->u.counters))[counter_nr]);
+}
+
+#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#endif /* ERL_FLXCTR_H__ */
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index d5dfb096b1..13b1f8ab4d 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -151,6 +151,7 @@ static void grow_new_heap(Process *p, Uint new_sz, Eterm* objv, int nobj);
 static void sweep_off_heap(Process *p, int fullsweep);
 static void offset_heap(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size);
 static void offset_heap_ptr(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size);
+static void offset_heap_ptr_nstack(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size);
 static void offset_rootset(Process *p, Sint offs, char* area, Uint area_size,
 			   Eterm* objv, int nobj);
 static void offset_off_heap(Process* p, Sint offs, char* area, Uint area_size);
@@ -577,7 +578,7 @@ force_reschedule:
 }
 
 static ERTS_FORCE_INLINE Uint
-young_gen_usage(Process *p)
+young_gen_usage(Process *p, Uint *ext_msg_usage)
 {
     Uint hsz;
     Eterm *aheap;
@@ -604,7 +605,10 @@ young_gen_usage(Process *p)
                 if (ERTS_SIG_IS_MSG(mp)
                     && mp->data.attached
                     && mp->data.attached != ERTS_MSG_COMBINED_HFRAG) {
-                    hsz += erts_msg_attached_data_size(mp);
+                    Uint sz = erts_msg_attached_data_size(mp);
+                    if (ERTS_SIG_IS_EXTERNAL_MSG(mp))
+                        *ext_msg_usage += sz;
+                    hsz += sz;
                 }
             });
     }
@@ -676,6 +680,7 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
 {
     Uint reclaimed_now = 0;
     Uint ygen_usage;
+    Uint ext_msg_usage = 0;
     Eterm gc_trace_end_tag;
     int reds;
     ErtsMonotonicTime start_time;
@@ -698,7 +703,7 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
 	return delay_garbage_collection(p, live_hf_end, need, fcalls);
     }
 
-    ygen_usage = max_young_gen_usage ? max_young_gen_usage : young_gen_usage(p);
+    ygen_usage = max_young_gen_usage ? max_young_gen_usage : young_gen_usage(p, &ext_msg_usage);
 
     if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
 	check_for_possibly_long_gc(p, ygen_usage);
@@ -739,7 +744,7 @@ garbage_collect(Process* p, ErlHeapFragment *live_hf_end,
             trace_gc(p, am_gc_minor_start, need, THE_NON_VALUE);
         }
         DTRACE2(gc_minor_start, pidbuf, need);
-        reds = minor_collection(p, live_hf_end, need, objv, nobj,
+        reds = minor_collection(p, live_hf_end, need + ext_msg_usage, objv, nobj,
 				ygen_usage, &reclaimed_now);
         DTRACE2(gc_minor_end, pidbuf, reclaimed_now);
         if (reds == -1) {
@@ -764,7 +769,7 @@ do_major_collection:
             trace_gc(p, am_gc_major_start, need, THE_NON_VALUE);
         }
         DTRACE2(gc_major_start, pidbuf, need);
-        reds = major_collection(p, live_hf_end, need, objv, nobj,
+        reds = major_collection(p, live_hf_end, need + ext_msg_usage, objv, nobj,
 				ygen_usage, &reclaimed_now);
         if (ERTS_SCHEDULER_IS_DIRTY(esdp))
             p->flags &= ~(F_DIRTY_MAJOR_GC|F_DIRTY_MINOR_GC);
@@ -1050,9 +1055,10 @@ erts_garbage_collect_hibernate(Process* p)
 		n_htop = tmp_n_htop;					\
 	} while(0)
 
+
 /*
  * offset_nstack() can ignore the descriptor-based traversal the other
- * nstack procedures use and simply call offset_heap_ptr() instead.
+ * nstack procedures use and do a simpler word by word traversal instead.
  * This relies on two facts:
  * 1. The only live non-Erlang terms on an nstack are return addresses,
  *    and they will be skipped thanks to the low/high range check.
@@ -1067,14 +1073,51 @@ static ERTS_INLINE void offset_nstack(Process* p, Sint offs,
 {
     if (p->hipe.nstack) {
 	ASSERT(p->hipe.nsp && p->hipe.nstend);
-	offset_heap_ptr(hipe_nstack_start(p), hipe_nstack_used(p),
-			offs, area, area_size);
+	offset_heap_ptr_nstack(hipe_nstack_start(p), hipe_nstack_used(p),
+                               offs, area, area_size);
     }
     else {
 	ASSERT(!p->hipe.nsp && !p->hipe.nstend);
     }
 }
 
+/*
+ * This is the same as offset_heap_ptr()
+ *
+ * Except for VALGRIND. It allows benign offsetting of undefined (dead) words
+ * on the nstack while also retaining them as undefined. This suppresses
+ * valgrinds "Conditional jump or move depends on uninitialised value(s)".
+ */
+static void
+offset_heap_ptr_nstack(Eterm* hp, Uint sz, Sint offs,
+                       char* area, Uint area_size)
+{
+    while (sz--) {
+	Eterm val = *hp;
+#ifdef VALGRIND
+        Eterm val_vbits;
+        VALGRIND_GET_VBITS(&val, &val_vbits, sizeof(val));
+        VALGRIND_MAKE_MEM_DEFINED(&val, sizeof(val));
+#endif
+	switch (primary_tag(val)) {
+	case TAG_PRIMARY_LIST:
+	case TAG_PRIMARY_BOXED:
+	    if (ErtsInArea(ptr_val(val), area, area_size)) {
+#ifdef VALGRIND
+                VALGRIND_SET_VBITS(&val, val_vbits, sizeof(val));
+#endif
+		*hp = offset_ptr(val, offs);
+	    }
+	    hp++;
+	    break;
+	default:
+	    hp++;
+	    break;
+	}
+    }
+}
+
+
 #else /* !HIPE */
 
 #define fullsweep_nstack(p,n_htop)		        	(n_htop)
@@ -1101,6 +1144,7 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
     Eterm* old_htop;
     Uint n;
     Uint ygen_usage = 0;
+    Uint ext_msg_usage = 0;
     struct erl_off_heap_header** prev = NULL;
     Sint64 reds;
     int hibernated = !!(p->flags & F_HIBERNATED);
@@ -1118,7 +1162,7 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
 	p->flags &= ~F_DIRTY_CLA;
     else {
         Uint size = byte_lit_size/sizeof(Uint);
-	ygen_usage = young_gen_usage(p);
+	ygen_usage = young_gen_usage(p, &ext_msg_usage);
         if (hibernated)
             size = size*2 + 3*ygen_usage;
         else
@@ -1130,7 +1174,7 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
 	}
     }
 
-    reds = (Sint64) garbage_collect(p, ERTS_INVALID_HFRAG_PTR, 0,
+    reds = (Sint64) garbage_collect(p, ERTS_INVALID_HFRAG_PTR, ext_msg_usage,
 				    p->arg_reg, p->arity, fcalls,
 				    ygen_usage);
     if (ERTS_PROC_IS_EXITING(p)) {
@@ -1303,7 +1347,8 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
                     ExternalThing *etp;
                     ASSERT(is_external_header(ptr->thing_word));
                     etp = (ExternalThing *) ptr;
-                    erts_refc_inc(&etp->node->refc, 1);
+                    erts_ref_node_entry(etp->node, 1,
+                                        make_boxed(&oh->thing_word));
                     break;
                 }
             }
@@ -1347,6 +1392,9 @@ minor_collection(Process* p, ErlHeapFragment *live_hf_end,
     Eterm *mature = p->abandoned_heap ? p->abandoned_heap : p->heap;
     Uint mature_size = p->high_water - mature;
     Uint size_before = ygen_usage;
+#ifdef DEBUG
+    Uint debug_tmp = 0;
+#endif
 
     /*
      * Check if we have gone past the max heap size limit
@@ -1483,7 +1531,7 @@ minor_collection(Process* p, ErlHeapFragment *live_hf_end,
            process from there */
         ASSERT(!MAX_HEAP_SIZE_GET(p) ||
                !(MAX_HEAP_SIZE_FLAGS_GET(p) & MAX_HEAP_SIZE_KILL) ||
-               MAX_HEAP_SIZE_GET(p) > (young_gen_usage(p) +
+               MAX_HEAP_SIZE_GET(p) > (young_gen_usage(p, &debug_tmp) +
                                        (OLD_HEND(p) - OLD_HEAP(p)) +
                                        (HEAP_END(p) - HEAP_TOP(p))));
 
@@ -2438,27 +2486,9 @@ erts_copy_one_frag(Eterm** hpp, ErlOffHeap* off_heap,
 	    cpy_words:
 		ASSERT(sz >= cpy_sz);
 		sz -= cpy_sz;
-		while (cpy_sz >= 8) {
-		    cpy_sz -= 8;
-		    *hp++ = *fhp++;
-		    *hp++ = *fhp++;
-		    *hp++ = *fhp++;
-		    *hp++ = *fhp++;
-		    *hp++ = *fhp++;
-		    *hp++ = *fhp++;
-		    *hp++ = *fhp++;
-		    *hp++ = *fhp++;
-		}
-		switch (cpy_sz) {
-		case 7: *hp++ = *fhp++;
-		case 6: *hp++ = *fhp++;
-		case 5: *hp++ = *fhp++;
-		case 4: *hp++ = *fhp++;
-		case 3: *hp++ = *fhp++;
-		case 2: *hp++ = *fhp++;
-		case 1: *hp++ = *fhp++;
-		default: break;
-		}
+                sys_memcpy(hp, fhp, cpy_sz * sizeof(Eterm));
+                hp += cpy_sz;
+                fhp += cpy_sz;
 		if (oh) {
 		    /* Add to offheap list */
 		    oh->next = off_heap->first;
@@ -2477,7 +2507,7 @@ erts_copy_one_frag(Eterm** hpp, ErlOffHeap* off_heap,
     *hpp = hp;
 
     for (i = 0; i < nrefs; i++) {
-	if (is_not_immed(refs[i]) && !erts_is_literal(refs[i],boxed_val(refs[i])))
+	if (is_not_immed(refs[i]) && !erts_is_literal(refs[i],ptr_val(refs[i])))
 	    refs[i] = offset_ptr(refs[i], offs);
     }
     bp->off_heap.first = NULL;
@@ -2854,7 +2884,11 @@ sweep_off_heap(Process *p, int fullsweep)
     while (ptr) {
 	if (IS_MOVED_BOXED(ptr->thing_word)) {
 	    ASSERT(!ErtsInArea(ptr, oheap, oheap_sz));
-	    *prev = ptr = (struct erl_off_heap_header*) boxed_val(ptr->thing_word);
+            if (is_external_header(((struct erl_off_heap_header*) boxed_val(ptr->thing_word))->thing_word))
+                erts_node_bookkeep(((ExternalThing*)ptr)->node,
+                                   make_boxed(&ptr->thing_word),
+                                   ERL_NODE_DEC, __FILE__, __LINE__);
+            *prev = ptr = (struct erl_off_heap_header*) boxed_val(ptr->thing_word);
 	    ASSERT(!IS_MOVED_BOXED(ptr->thing_word));
 	    switch (ptr->thing_word) {
 	    case HEADER_PROC_BIN: {
@@ -2881,6 +2915,11 @@ sweep_off_heap(Process *p, int fullsweep)
                 /* fall through... */
             }
             default:
+                if (is_external_header(ptr->thing_word)) {
+                    erts_node_bookkeep(((ExternalThing*)ptr)->node,
+                                       make_boxed(&ptr->thing_word),
+                                       ERL_NODE_INC, __FILE__, __LINE__);
+                }
 		prev = &ptr->next;
 		ptr = ptr->next;
 	    }
@@ -2914,7 +2953,8 @@ sweep_off_heap(Process *p, int fullsweep)
 		}
 	    default:
 		ASSERT(is_external_header(ptr->thing_word));
-		erts_deref_node_entry(((ExternalThing*)ptr)->node);
+		erts_deref_node_entry(((ExternalThing*)ptr)->node,
+                                      make_boxed(&ptr->thing_word));
 	    }
 	    *prev = ptr = ptr->next;
 	}
@@ -3047,6 +3087,15 @@ offset_heap(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size)
 		  {
 		      struct erl_off_heap_header* oh = (struct erl_off_heap_header*) hp;
 
+                      if (is_external_header(oh->thing_word)) {
+                          erts_node_bookkeep(((ExternalThing*)oh)->node,
+                                             make_boxed(((Eterm*)oh)-offs),
+                                             ERL_NODE_DEC, __FILE__, __LINE__);
+                          erts_node_bookkeep(((ExternalThing*)oh)->node,
+                                             make_boxed((Eterm*)oh), ERL_NODE_INC,
+                                             __FILE__, __LINE__);
+                      }
+
 		      if (ErtsInArea(oh->next, area, area_size)) {
 			  Eterm** uptr = (Eterm **) (void *) &oh->next;
 			  *uptr += offs; /* Patch the mso chain */
diff --git a/erts/emulator/beam/erl_goodfit_alloc.c b/erts/emulator/beam/erl_goodfit_alloc.c
index 01d4aa54ff..68b9579433 100644
--- a/erts/emulator/beam/erl_goodfit_alloc.c
+++ b/erts/emulator/beam/erl_goodfit_alloc.c
@@ -226,6 +226,8 @@ erts_gfalc_start(GFAllctr_t *gfallctr,
     allctr->add_mbc		        = NULL;
     allctr->remove_mbc		        = NULL;
     allctr->largest_fblk_in_mbc         = NULL;
+    allctr->first_fblk_in_mbc           = NULL;
+    allctr->next_fblk_in_mbc            = NULL;
     allctr->init_atoms			= init_atoms;
 
 #ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
diff --git a/erts/emulator/beam/erl_hl_timer.c b/erts/emulator/beam/erl_hl_timer.c
index ef7a55fa38..b0eb0e85c0 100644
--- a/erts/emulator/beam/erl_hl_timer.c
+++ b/erts/emulator/beam/erl_hl_timer.c
@@ -29,8 +29,6 @@
 #  include "config.h"
 #endif
 
-/* #define ERTS_MAGIC_REF_BIF_TIMERS */
-
 #include "sys.h"
 #include "global.h"
 #include "bif.h"
@@ -39,9 +37,6 @@
 #include "erl_time.h"
 #include "erl_hl_timer.h"
 #include "erl_proc_sig_queue.h"
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-#include "erl_binary.h"
-#endif
 
 #define ERTS_TMR_CHECK_CANCEL_ON_CREATE 0
 
@@ -195,14 +190,9 @@ struct ErtsBifTimer_ {
     } type;
     struct {
         erts_atomic32_t state;
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-        ErtsMagicBinary *mbin;
-        ErtsHLTimerList proc_list;
-#else
 	Uint32 refn[ERTS_REF_NUMBERS];
 	ErtsBifTimerTree proc_tree;
 	ErtsBifTimerTree tree;
-#endif
         Eterm message;
         ErlHeapFragment *bp;
     } btm;
@@ -220,11 +210,7 @@ typedef ErtsTimer *(*ErtsCreateTimerFunc)(ErtsSchedulerData *esdp,
                                           int short_time, ErtsTmrType type,
                                           void *rcvrp, Eterm rcvr,
                                           Eterm msg,
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-                                          ErtsMagicBinary *mbin,
-#else
                                           Uint32 *refn,
-#endif
                                           void (*callback)(void *), void *arg);
 
 #ifdef SMALL_MEMORY
@@ -303,16 +289,12 @@ typedef struct {
 struct ErtsHLTimerService_ {
     ErtsHLTCncldTmrQ canceled_queue;
     ErtsHLTimer *time_tree;
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
     ErtsBifTimer *btm_tree;
-#endif
     ErtsHLTimer *next_timeout;
     ErtsYieldingTimeoutState yield;
     ErtsTWheelTimer service_timer;
 };
 
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
-
 static ERTS_INLINE int
 refn_is_lt(Uint32 *x, Uint32 *y)
 {
@@ -334,8 +316,6 @@ refn_is_eq(Uint32 *x, Uint32 *y)
     return (x[0] == y[0]) & (x[1] == y[1]) & (x[2] == y[2]);
 }
 
-#endif
-
 #define ERTS_RBT_PREFIX time
 #define ERTS_RBT_T ErtsHLTimer
 #define ERTS_RBT_KEY_T ErtsMonotonicTime
@@ -525,13 +505,7 @@ same_time_list_lookup(ErtsHLTimer *root, ErtsHLTimer *x)
 
 #endif /* ERTS_HLT_HARD_DEBUG */
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-#define ERTS_BTM_HLT2REFN(T) ((T)->btm.mbin->refn)
-#else
 #define ERTS_BTM_HLT2REFN(T) ((T)->btm.refn)
-#endif
-
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
 
 #define ERTS_RBT_PREFIX btm
 #define ERTS_RBT_T ErtsBifTimer
@@ -576,87 +550,12 @@ same_time_list_lookup(ErtsHLTimer *root, ErtsHLTimer *x)
 #define ERTS_RBT_IS_EQ(KX, KY) refn_is_eq((KX), (KY))
 #define ERTS_RBT_WANT_DELETE
 #define ERTS_RBT_WANT_INSERT
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
 #define ERTS_RBT_WANT_LOOKUP
-#endif
 #define ERTS_RBT_WANT_FOREACH
 #define ERTS_RBT_UNDEF
 
 #include "erl_rbtree.h"
 
-#endif /* !ERTS_MAGIC_REF_BIF_TIMERS */
-
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-
-static ERTS_INLINE void
-proc_btm_list_insert(ErtsBifTimer **list, ErtsBifTimer *x)
-{
-    ErtsBifTimer *y = *list;
-    if (!y) {
-        x->btm.proc_list.next = x;
-        x->btm.proc_list.prev = x;
-        *list = x;
-    }
-    else {
-        ERTS_HLT_ASSERT(y->btm.proc_list.prev->btm.proc_list.next == y);
-        x->btm.proc_list.next = y;
-        x->btm.proc_list.prev = y->btm.proc_list.prev;
-        y->btm.proc_list.prev->btm.proc_list.next = x;
-        y->btm.proc_list.prev = x;
-    }
-}
-
-static ERTS_INLINE void
-proc_btm_list_delete(ErtsBifTimer **list, ErtsBifTimer *x)
-{
-    ErtsBifTimer *y = *list;
-    if (y == x && x->btm.proc_list.next == x) {
-        ERTS_HLT_ASSERT(x->btm.proc_list.prev == x);
-        *list = NULL;
-    }
-    else {
-        if (y == x)
-            *list = x->btm.proc_list.next;
-        ERTS_HLT_ASSERT(x->btm.proc_list.prev->btm.proc_list.next == x);
-        ERTS_HLT_ASSERT(x->btm.proc_list.next->btm.proc_list.prev == x);
-        x->btm.proc_list.prev->btm.proc_list.next = x->btm.proc_list.next;
-        x->btm.proc_list.next->btm.proc_list.prev = x->btm.proc_list.prev;
-    }
-    x->btm.proc_list.next = NULL;
-}
-
-static ERTS_INLINE int
-proc_btm_list_foreach_destroy_yielding(ErtsBifTimer **list,
-                                       void (*destroy)(ErtsBifTimer *, void *),
-                                       void *arg,
-                                       int limit)
-{
-    int i;
-    ErtsBifTimer *first, *last;
-
-    first = *list;
-    if (!first)
-        return 0;
-
-    last = first->btm.proc_list.prev;
-    for (i = 0; i < limit; i++) {
-        ErtsBifTimer *x = last;
-        last = last->btm.proc_list.prev;
-        (*destroy)(x, arg);
-        x->btm.proc_list.next = NULL;
-        if (x == first) {
-            *list = NULL;
-            return 0;
-        }
-    }
-
-    last->btm.proc_list.next = first;
-    first->btm.proc_list.prev = last;
-    return 1;
-}
-
-#else /* !ERTS_MAGIC_REF_BIF_TIMERS */
-
 #define ERTS_RBT_PREFIX proc_btm
 #define ERTS_RBT_T ErtsBifTimer
 #define ERTS_RBT_KEY_T Uint32 *
@@ -700,16 +599,12 @@ proc_btm_list_foreach_destroy_yielding(ErtsBifTimer **list,
 #define ERTS_RBT_IS_EQ(KX, KY) refn_is_eq((KX), (KY))
 #define ERTS_RBT_WANT_DELETE
 #define ERTS_RBT_WANT_INSERT
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
 #define ERTS_RBT_WANT_LOOKUP
-#endif
 #define ERTS_RBT_WANT_FOREACH_DESTROY_YIELDING
 #define ERTS_RBT_UNDEF
 
 #include "erl_rbtree.h"
 
-#endif /* !ERTS_MAGIC_REF_BIF_TIMERS */
-
 static void init_canceled_queue(ErtsHLTCncldTmrQ *cq);
 
 void
@@ -728,9 +623,7 @@ erts_create_timer_service(void)
     srv = erts_alloc_permanent_cache_aligned(ERTS_ALC_T_TIMER_SERVICE,
 					     sizeof(ErtsHLTimerService));
     srv->time_tree = NULL;
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
     srv->btm_tree = NULL;
-#endif
     srv->next_timeout = NULL;
     srv->yield = init_yield;
     erts_twheel_init_timer(&srv->service_timer);
@@ -805,40 +698,10 @@ port_timeout_common(Port *port, void *tmr)
     return 0;
 }
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-
-static erts_atomic_t *
-mbin_to_btmref__(ErtsMagicBinary *mbin)
-{
-    return erts_binary_to_magic_indirection((Binary *) mbin);
-}
-
-static ERTS_INLINE void
-magic_binary_init(ErtsMagicBinary *mbin, ErtsBifTimer *tmr)
-{
-    erts_atomic_t *aptr = mbin_to_btmref__(mbin);
-    erts_atomic_init_nob(aptr, (erts_aint_t) tmr);
-}
-
-static ERTS_INLINE ErtsBifTimer *
-magic_binary_to_btm(ErtsMagicBinary *mbin)
-{
-    erts_atomic_t *aptr = mbin_to_btmref__(mbin);
-    ErtsBifTimer *tmr = (ErtsBifTimer *) erts_atomic_read_nob(aptr);
-    ERTS_HLT_ASSERT(!tmr || tmr->btm.mbin == mbin);
-    return tmr;
-}
-
-#endif /* ERTS_MAGIC_REF_BIF_TIMERS */
-
 static ERTS_INLINE erts_aint_t
 init_btm_specifics(ErtsSchedulerData *esdp,
                    ErtsBifTimer *tmr, Eterm msg,
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-                   ErtsMagicBinary *mbin
-#else
                    Uint32 *refn
-#endif
     )
 {
     Uint hsz = is_immed(msg) ? ((Uint) 0) : size_object(msg);
@@ -853,13 +716,6 @@ init_btm_specifics(ErtsSchedulerData *esdp,
         tmr->btm.message = copy_struct(msg, hsz, &hp, &bp->off_heap);
         tmr->btm.bp = bp;
     }
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-    refc = 1;
-    tmr->btm.mbin = mbin;
-    erts_refc_inc(&mbin->refc, 1);
-    magic_binary_init(mbin, tmr);
-    tmr->btm.proc_list.next = NULL;
-#else
     refc = 0;
     tmr->btm.refn[0] = refn[0];
     tmr->btm.refn[1] = refn[1];
@@ -868,7 +724,6 @@ init_btm_specifics(ErtsSchedulerData *esdp,
     tmr->btm.proc_tree.parent = ERTS_HLT_PFIELD_NOT_IN_TABLE;
 
     btm_rbt_insert(&esdp->timer_service->btm_tree, tmr);
-#endif
 
     erts_atomic32_init_nob(&tmr->btm.state, ERTS_TMR_STATE_ACTIVE);
     return refc; /* refc from magic binary... */
@@ -886,11 +741,6 @@ timer_destroy(ErtsTimer *tmr, int twt, int btm)
             erts_free(ERTS_ALC_T_HL_PTIMER, tmr);
     }
     else {
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-        Binary *bp = (Binary *) tmr->btm.btm.mbin;
-        if (erts_refc_dectest(&bp->refc, 0) == 0)
-            erts_bin_free(bp);
-#endif
 	if (tmr->head.roflgs & ERTS_TMR_ROFLG_PRE_ALC)
 	    bif_timer_pre_free(&tmr->btm);
 	else
@@ -940,9 +790,6 @@ schedule_tw_timer_destroy(ErtsTWTimer *tmr)
     else {
 	/* Message buffer already dropped... */
 	size = sizeof(ErtsBifTimer);
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-        size += sizeof(ErtsMagicIndirectionWord);
-#endif
     }
 
     erts_schedule_thr_prgr_later_cleanup_op(
@@ -1006,11 +853,7 @@ create_tw_timer(ErtsSchedulerData *esdp,
 		int short_time, ErtsTmrType type,
 		void *rcvrp, Eterm rcvr,
 		Eterm msg,
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-                ErtsMagicBinary *mbin,
-#else
                 Uint32 *refn,
-#endif
 		void (*callback)(void *), void *arg)
 {
     ErtsTWTimer *tmr;
@@ -1087,11 +930,7 @@ create_tw_timer(ErtsSchedulerData *esdp,
         refc += init_btm_specifics(esdp,
                                    (ErtsBifTimer *) tmr,
                                    msg,
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-                                   mbin
-#else
                                    refn
-#endif
             );
         break;
 
@@ -1152,9 +991,6 @@ schedule_hl_timer_destroy(ErtsHLTimer *tmr, Uint32 roflgs)
     else {
 	/* Message buffer already dropped... */
 	size = sizeof(ErtsBifTimer);
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-        size += sizeof(ErtsMagicIndirectionWord);
-#endif
     }
 
     erts_schedule_thr_prgr_later_cleanup_op(
@@ -1192,34 +1028,6 @@ check_canceled_queue(ErtsSchedulerData *esdp, ErtsHLTimerService *srv)
 #endif
 }
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-
-static int
-bif_timer_ref_destructor(Binary *unused)
-{
-    return 1;
-}
-
-static ERTS_INLINE void
-btm_clear_magic_binary(ErtsBifTimer *tmr)
-{
-    erts_atomic_t *aptr = mbin_to_btmref__(tmr->btm.mbin);
-    Uint32 roflgs = tmr->type.head.roflgs;
-#ifdef ERTS_HLT_DEBUG
-    erts_aint_t tval = erts_atomic_xchg_nob(aptr,
-                                                (erts_aint_t) NULL);
-    ERTS_HLT_ASSERT(tval == (erts_aint_t) tmr);
-#else
-    erts_atomic_set_nob(aptr, (erts_aint_t) NULL);
-#endif
-    if (roflgs & ERTS_TMR_ROFLG_HLT)
-        hl_timer_dec_refc(&tmr->type.hlt, roflgs);
-    else
-        tw_timer_dec_refc(&tmr->type.twt);
-}
-
-#endif /* ERTS_MAGIC_REF_BIF_TIMERS */
-
 static ERTS_INLINE void
 bif_timer_timeout(ErtsHLTimerService *srv,
                   ErtsBifTimer *tmr,
@@ -1240,10 +1048,6 @@ bif_timer_timeout(ErtsHLTimerService *srv,
     if (state == ERTS_TMR_STATE_ACTIVE) {
         Process *proc;
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-        btm_clear_magic_binary(tmr);
-#endif
-
         if (roflgs & ERTS_TMR_ROFLG_REG_NAME) {
             Eterm term;
             term = tmr->type.head.receiver.name;
@@ -1266,18 +1070,11 @@ bif_timer_timeout(ErtsHLTimerService *srv,
             erts_proc_lock(proc, ERTS_PROC_LOCK_BTM);
             /* If the process is exiting do not disturb the cleanup... */
             if (!ERTS_PROC_IS_EXITING(proc)) {
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-                if (tmr->btm.proc_list.next) {
-                    proc_btm_list_delete(&proc->bif_timers, tmr);
-                    dec_refc = 1;
-                }
-#else
                 if (tmr->btm.proc_tree.parent != ERTS_HLT_PFIELD_NOT_IN_TABLE) {
                     proc_btm_rbt_delete(&proc->bif_timers, tmr);
                     tmr->btm.proc_tree.parent = ERTS_HLT_PFIELD_NOT_IN_TABLE;
                     dec_refc = 1;
                 }
-#endif
             }
             erts_proc_unlock(proc, ERTS_PROC_LOCK_BTM);
             if (dec_refc)
@@ -1287,25 +1084,18 @@ bif_timer_timeout(ErtsHLTimerService *srv,
             free_message_buffer(tmr->btm.bp);
     }
 
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
     if (tmr->btm.tree.parent != ERTS_HLT_PFIELD_NOT_IN_TABLE) {
 	btm_rbt_delete(&srv->btm_tree, tmr);
 	tmr->btm.tree.parent = ERTS_HLT_PFIELD_NOT_IN_TABLE;
     }
-#endif
-
 
 }
 
 static void
 tw_bif_timer_timeout(void *vbtmp)
 {
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-    ErtsHLTimerService *srv = NULL;
-#else
     ErtsSchedulerData *esdp = erts_get_scheduler_data();
     ErtsHLTimerService *srv = esdp->timer_service;
-#endif
     ErtsBifTimer *btmp = (ErtsBifTimer *) vbtmp;
     bif_timer_timeout(srv, btmp, btmp->type.head.roflgs);
     tw_timer_dec_refc(&btmp->type.twt);
@@ -1317,11 +1107,7 @@ create_hl_timer(ErtsSchedulerData *esdp,
 		int short_time, ErtsTmrType type,
 		void *rcvrp, Eterm rcvr,
 		Eterm msg,
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-                ErtsMagicBinary *mbin,
-#else
                 Uint32 *refn,
-#endif
 		void (*callback)(void *), void *arg)
 {
     ErtsHLTimerService *srv = esdp->timer_service;
@@ -1407,11 +1193,7 @@ create_hl_timer(ErtsSchedulerData *esdp,
         refc += init_btm_specifics(esdp,
                                    (ErtsBifTimer *) tmr,
                                    msg,
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-                                   mbin
-#else
                                    refn
-#endif
             );
     }
 
@@ -1628,7 +1410,6 @@ cleanup_sched_local_canceled_timer(ErtsSchedulerData *esdp,
     ERTS_HLT_ASSERT((tmr->head.roflgs & ERTS_TMR_ROFLG_SID_MASK)
 		    == (Uint32) esdp->no);
 
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
     if (roflgs & ERTS_TMR_ROFLG_BIF_TMR) {
         ErtsBifTimer *btm = (ErtsBifTimer *) tmr;
 	if (btm->btm.tree.parent != ERTS_HLT_PFIELD_NOT_IN_TABLE) {
@@ -1636,7 +1417,6 @@ cleanup_sched_local_canceled_timer(ErtsSchedulerData *esdp,
 	    btm->btm.tree.parent = ERTS_HLT_PFIELD_NOT_IN_TABLE;
 	}
     }
-#endif
 
     if (roflgs & ERTS_TMR_ROFLG_HLT) {
 	hlt_delete_timer(esdp, &tmr->hlt);
@@ -1909,9 +1689,6 @@ setup_bif_timer(Process *c_p, int twheel, ErtsMonotonicTime timeout_pos,
     Eterm ref, tmo_msg, *hp;
     ErtsBifTimer *tmr;
     ErtsSchedulerData *esdp;
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-    Binary *mbin;
-#endif
     Eterm tmp_hp[4];
     ErtsCreateTimerFunc create_timer;
 
@@ -1920,18 +1697,10 @@ setup_bif_timer(Process *c_p, int twheel, ErtsMonotonicTime timeout_pos,
 
     esdp = erts_proc_sched_data(c_p);
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-    mbin = erts_create_magic_indirection(bif_timer_ref_destructor);
-    hp = HAlloc(c_p, ERTS_MAGIC_REF_THING_SIZE);
-    ref = erts_mk_magic_ref(&hp, &c_p->off_heap, mbin);
-    ASSERT(erts_get_ref_numbers_thr_id(((ErtsMagicBinary *)mbin)->refn)
-           == (Uint32) esdp->no);
-#else
     hp = HAlloc(c_p, ERTS_REF_THING_SIZE);
     ref = erts_sched_make_ref_in_buffer(esdp, hp);
     ASSERT(erts_get_ref_numbers_thr_id(internal_ordinary_ref_numbers(ref))
            == (Uint32) esdp->no);
-#endif
 
     tmo_msg = wrap ? TUPLE3(tmp_hp, am_timeout, ref, msg) : msg;
 
@@ -1939,11 +1708,7 @@ setup_bif_timer(Process *c_p, int twheel, ErtsMonotonicTime timeout_pos,
     tmr = (ErtsBifTimer *) create_timer(esdp, timeout_pos,
                                         short_time, ERTS_TMR_BIF,
                                         NULL, rcvr, tmo_msg,
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-                                        (ErtsMagicBinary *) mbin,
-#else
                                         internal_ordinary_ref_numbers(ref),
-#endif
                                         NULL, NULL);
 
     if (is_internal_pid(rcvr)) {
@@ -1951,14 +1716,10 @@ setup_bif_timer(Process *c_p, int twheel, ErtsMonotonicTime timeout_pos,
 					  rcvr, ERTS_PROC_LOCK_BTM,
 					  ERTS_P2P_FLG_INC_REFC);
 	if (!proc) {
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-            btm_clear_magic_binary(tmr);
-#else
             if (tmr->btm.tree.parent != ERTS_HLT_PFIELD_NOT_IN_TABLE) {
                 btm_rbt_delete(&esdp->timer_service->btm_tree, tmr);
                 tmr->btm.tree.parent = ERTS_HLT_PFIELD_NOT_IN_TABLE;
             }
-#endif
 	    if (tmr->btm.bp)
 		free_message_buffer(tmr->btm.bp);
             if (twheel)
@@ -1968,11 +1729,7 @@ setup_bif_timer(Process *c_p, int twheel, ErtsMonotonicTime timeout_pos,
             timer_destroy((ErtsTimer *) tmr, twheel, 1);
 	}
 	else {
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-            proc_btm_list_insert(&proc->bif_timers, tmr);
-#else
 	    proc_btm_rbt_insert(&proc->bif_timers, tmr);
-#endif
 	    erts_proc_unlock(proc, ERTS_PROC_LOCK_BTM);
             tmr->type.head.receiver.proc = proc;
 	}
@@ -2000,10 +1757,6 @@ cancel_bif_timer(ErtsBifTimer *tmr)
     if (state != ERTS_TMR_STATE_ACTIVE)
 	return 0;
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-    btm_clear_magic_binary(tmr);
-#endif
-
     if (tmr->btm.bp)
 	free_message_buffer(tmr->btm.bp);
 
@@ -2022,19 +1775,12 @@ cancel_bif_timer(ErtsBifTimer *tmr)
 	 * the btm tree by itself (it may be in
 	 * the middle of tree destruction).
 	 */
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-        if (!ERTS_PROC_IS_EXITING(proc) && tmr->btm.proc_list.next) {
-            proc_btm_list_delete(&proc->bif_timers, tmr);
-            res = 1;
-        }
-#else
 	if (!ERTS_PROC_IS_EXITING(proc)
 	    && tmr->btm.proc_tree.parent != ERTS_HLT_PFIELD_NOT_IN_TABLE) {
 	    proc_btm_rbt_delete(&proc->bif_timers, tmr);
 	    tmr->btm.proc_tree.parent = ERTS_HLT_PFIELD_NOT_IN_TABLE;
 	    res = 1;
 	}
-#endif
 	erts_proc_unlock(proc, ERTS_PROC_LOCK_BTM);
     }
 
@@ -2075,12 +1821,10 @@ access_btm(ErtsBifTimer *tmr, Uint32 sid, ErtsSchedulerData *esdp, int cancel)
             queue_canceled_timer(esdp, sid, (ErtsTimer *) tmr);
     }
     else {
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
         if (tmr->btm.tree.parent != ERTS_HLT_PFIELD_NOT_IN_TABLE) {
 	    btm_rbt_delete(&esdp->timer_service->btm_tree, tmr);
 	    tmr->btm.tree.parent = ERTS_HLT_PFIELD_NOT_IN_TABLE;
 	}
-#endif
         if (is_hlt) {
             if (cncl_res > 0)
                 hl_timer_dec_refc(&tmr->type.hlt, tmr->type.hlt.head.roflgs);
@@ -2157,52 +1901,6 @@ send_async_info(Process *proc, ErtsProcLocks initial_locks,
     return am_ok;
 }
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-
-static BIF_RETTYPE
-access_bif_timer(Process *c_p, Eterm tref, int cancel, int async, int info)
-{
-    BIF_RETTYPE ret;
-    Eterm res;
-    Sint64 time_left;
-
-    if (!is_internal_magic_ref(tref)) {
-	if (is_not_ref(tref)) {
-            ERTS_BIF_PREP_ERROR(ret, c_p, BADARG);
-            return ret;
-        }
-        time_left = -1;
-    }
-    else {
-        ErtsMagicBinary *mbin;
-        mbin = (ErtsMagicBinary *) erts_magic_ref2bin(tref);
-        if (mbin->destructor != bif_timer_ref_destructor)
-            time_left = -1;
-        else {
-            ErtsBifTimer *tmr;
-            Uint32 sid;
-            tmr = magic_binary_to_btm(mbin);
-            sid = erts_get_ref_numbers_thr_id(internal_magic_ref_numbers(tref));
-            ASSERT(1 <= sid && sid <= erts_no_schedulers);
-            time_left = access_btm(tmr, sid, erts_proc_sched_data(c_p), cancel);
-        }
-    }
-
-    if (!info)
-        res = am_ok;
-    else if (!async)
-        res = return_info(c_p, time_left);
-    else
-        res = send_async_info(c_p, ERTS_PROC_LOCK_MAIN,
-                              tref, cancel, time_left);
-
-    ERTS_BIF_PREP_RET(ret, res);
-
-    return ret;
-}
-
-#else /* !ERTS_MAGIC_REF_BIF_TIMERS */
-
 static ERTS_INLINE Eterm
 send_sync_info(Process *proc, ErtsProcLocks initial_locks,
                Uint32 *refn, int cancel, Sint64 time_left)
@@ -2505,8 +2203,6 @@ no_timer:
     return no_timer_result(c_p, tref, cancel, async, info);
 }
 
-#endif /* !ERTS_MAGIC_REF_BIF_TIMERS */
-
 static ERTS_INLINE int
 bool_arg(Eterm val, int *argp)
 {
@@ -2567,9 +2263,10 @@ parse_bif_timer_options(Eterm option_list, int *async,
     return 1;
 }
 
-static void
-exit_cancel_bif_timer(ErtsBifTimer *tmr, void *vesdp)
+static int
+exit_cancel_bif_timer(ErtsBifTimer *tmr, void *vesdp, Sint reds)
 {
+#define ERTS_BTM_CANCEL_REDS 80
     ErtsSchedulerData *esdp = (ErtsSchedulerData *) vesdp;
     Uint32 sid, roflgs;
     erts_aint_t state;
@@ -2584,32 +2281,23 @@ exit_cancel_bif_timer(ErtsBifTimer *tmr, void *vesdp)
     is_hlt = !!(roflgs & ERTS_TMR_ROFLG_HLT);
 
     ERTS_HLT_ASSERT(sid == erts_get_ref_numbers_thr_id(ERTS_BTM_HLT2REFN(tmr)));
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-    ERTS_HLT_ASSERT(tmr->btm.proc_list.next);
-#else
     ERTS_HLT_ASSERT(tmr->btm.proc_tree.parent
 		    != ERTS_HLT_PFIELD_NOT_IN_TABLE);
     tmr->btm.proc_tree.parent = ERTS_HLT_PFIELD_NOT_IN_TABLE;
-#endif
 
     if (state == ERTS_TMR_STATE_ACTIVE) {
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-        btm_clear_magic_binary(tmr);
-#endif
         if (tmr->btm.bp)
             free_message_buffer(tmr->btm.bp);
 
         if (sid != (Uint32) esdp->no) {
             queue_canceled_timer(esdp, sid, (ErtsTimer *) tmr);
-            return;
+            return ERTS_BTM_CANCEL_REDS;
         }
 
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
         if (tmr->btm.tree.parent != ERTS_HLT_PFIELD_NOT_IN_TABLE) {
 	    btm_rbt_delete(&esdp->timer_service->btm_tree, tmr);
 	    tmr->btm.tree.parent = ERTS_HLT_PFIELD_NOT_IN_TABLE;
 	}
-#endif
         if (is_hlt)
             hlt_delete_timer(esdp, &tmr->type.hlt);
         else
@@ -2619,36 +2307,19 @@ exit_cancel_bif_timer(ErtsBifTimer *tmr, void *vesdp)
         hl_timer_dec_refc(&tmr->type.hlt, roflgs);
     else
         tw_timer_dec_refc(&tmr->type.twt);
+    return ERTS_BTM_CANCEL_REDS;
 }
 
-#ifdef ERTS_HLT_DEBUG
-#  define ERTS_BTM_MAX_DESTROY_LIMIT 2
-#else
-#  define ERTS_BTM_MAX_DESTROY_LIMIT 50
-#endif
-
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
 typedef struct {
     ErtsBifTimers *bif_timers;
     union {
 	proc_btm_rbt_yield_state_t proc_btm_yield_state;
     } u;
 } ErtsBifTimerYieldState;
-#endif
 
-int erts_cancel_bif_timers(Process *p, ErtsBifTimers **btm, void **vyspp)
+int erts_cancel_bif_timers(Process *p, ErtsBifTimers **btm, void **vyspp, int reds)
 {
     ErtsSchedulerData *esdp = erts_proc_sched_data(p);
-
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-
-    return proc_btm_list_foreach_destroy_yielding(btm,
-                                                  exit_cancel_bif_timer,
-                                                  (void *) esdp,
-                                                  ERTS_BTM_MAX_DESTROY_LIMIT);
-
-#else /* !ERTS_MAGIC_REF_BIF_TIMERS */
-
     ErtsBifTimerYieldState ys = {*btm, {ERTS_RBT_YIELD_STAT_INITER}};
     ErtsBifTimerYieldState *ysp;
     int res;
@@ -2661,9 +2332,9 @@ int erts_cancel_bif_timers(Process *p, ErtsBifTimers **btm, void **vyspp)
 						exit_cancel_bif_timer,
 						(void *) esdp,
 						&ysp->u.proc_btm_yield_state,
-						ERTS_BTM_MAX_DESTROY_LIMIT);
+						reds);
 
-    if (res == 0) {
+    if (res > 0) {
 	if (ysp != &ys)
 	    erts_free(ERTS_ALC_T_BTM_YIELD_STATE, ysp);
 	*vyspp = NULL;
@@ -2682,7 +2353,6 @@ int erts_cancel_bif_timers(Process *p, ErtsBifTimers **btm, void **vyspp)
 
     return res;
 
-#endif /* !ERTS_MAGIC_REF_BIF_TIMERS */
 }
 
 static ERTS_INLINE int
@@ -3116,11 +2786,6 @@ btm_print(ErtsBifTimer *tmr, void *vbtmp, ErtsMonotonicTime tpos, int is_hlt)
     ErtsMonotonicTime left;
     Eterm receiver;
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-    if (!(tmr->type.head.roflgs & ERTS_TMR_ROFLG_BIF_TMR))
-        return;
-#endif
-
     if (is_hlt) {
         ERTS_HLT_ASSERT(tmr->type.head.roflgs & ERTS_TMR_ROFLG_HLT);
         if (tmr->type.hlt.timeout <= btmp->now)
@@ -3149,24 +2814,8 @@ btm_print(ErtsBifTimer *tmr, void *vbtmp, ErtsMonotonicTime tpos, int is_hlt)
 	       (Sint64) left);
 }
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-
-static void
-hlt_btm_print(ErtsHLTimer *tmr, void *vbtmp)
-{
-    btm_print((ErtsBifTimer *) tmr, vbtmp, 0, 1);
-}
-
-static void
-twt_btm_print(void *vbtmp, ErtsMonotonicTime tpos, void *vtwtp)
-{
-    btm_print((ErtsBifTimer *) vtwtp, vbtmp, tpos, 0);
-}
-
-#else
-
-static void
-btm_tree_print(ErtsBifTimer *tmr, void *vbtmp)
+static int
+btm_tree_print(ErtsBifTimer *tmr, void *vbtmp, Sint reds)
 {
     int is_hlt = !!(tmr->type.head.roflgs & ERTS_TMR_ROFLG_HLT);
     ErtsMonotonicTime tpos;
@@ -3175,10 +2824,9 @@ btm_tree_print(ErtsBifTimer *tmr, void *vbtmp)
     else
         tpos = erts_tweel_read_timeout(&tmr->type.twt.u.tw_tmr);
     btm_print(tmr, vbtmp, tpos, is_hlt);
+    return 1;
 }
 
-#endif
-
 void
 erts_print_bif_timer_info(fmtfn_t to, void *to_arg)
 {
@@ -3196,15 +2844,7 @@ erts_print_bif_timer_info(fmtfn_t to, void *to_arg)
     for (six = 0; six < erts_no_schedulers; six++) {
 	ErtsHLTimerService *srv =
 	    erts_aligned_scheduler_data[six].esd.timer_service;
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-	ErtsTimerWheel *twheel =
-	    erts_aligned_scheduler_data[six].esd.timer_wheel;
-	erts_twheel_debug_foreach(twheel, tw_bif_timer_timeout,
-				  twt_btm_print, (void *) &btmp);
-	time_rbt_foreach(srv->time_tree, hlt_btm_print, (void *) &btmp);
-#else
 	btm_rbt_foreach(srv->btm_tree, btm_tree_print, (void *) &btmp);
-#endif
     }
 }
 
@@ -3216,13 +2856,9 @@ typedef struct {
     void *arg;
 } ErtsBTMForeachDebug;
 
-static void
-debug_btm_foreach(ErtsBifTimer *tmr, void *vbtmfd)
+static int
+debug_btm_foreach(ErtsBifTimer *tmr, void *vbtmfd, Sint reds)
 {
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-    if (!(tmr->type.head.roflgs & ERTS_TMR_ROFLG_BIF_TMR))
-        return;
-#endif
     if (erts_atomic32_read_nob(&tmr->btm.state) == ERTS_TMR_STATE_ACTIVE) {
 	ErtsBTMForeachDebug *btmfd = (ErtsBTMForeachDebug *) vbtmfd;
         Eterm id = ((tmr->type.head.roflgs & ERTS_TMR_ROFLG_REG_NAME)
@@ -3230,24 +2866,9 @@ debug_btm_foreach(ErtsBifTimer *tmr, void *vbtmfd)
                     : tmr->type.head.receiver.proc->common.id);
 	(*btmfd->func)(id, tmr->btm.message, tmr->btm.bp, btmfd->arg);
     }
+    return 1;
 }
 
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-
-static void
-hlt_debug_btm_foreach(ErtsHLTimer *tmr, void *vbtmfd)
-{
-    debug_btm_foreach((ErtsBifTimer *) tmr, vbtmfd);
-}
-
-static void
-twt_debug_btm_foreach(void *vbtmfd, ErtsMonotonicTime tpos, void *vtwtp)
-{
-    debug_btm_foreach((ErtsBifTimer *) vtwtp, vbtmfd);
-}
-
-#endif
-
 void
 erts_debug_bif_timer_foreach(void (*func)(Eterm,
 					  Eterm,
@@ -3267,20 +2888,9 @@ erts_debug_bif_timer_foreach(void (*func)(Eterm,
     for (six = 0; six < erts_no_schedulers; six++) {
 	ErtsHLTimerService *srv =
 	    erts_aligned_scheduler_data[six].esd.timer_service;
-#ifdef ERTS_MAGIC_REF_BIF_TIMERS
-	ErtsTimerWheel *twheel =
-	    erts_aligned_scheduler_data[six].esd.timer_wheel;            
-	erts_twheel_debug_foreach(twheel, tw_bif_timer_timeout,
-				  twt_debug_btm_foreach,
-                                  (void *) &btmfd);
-        time_rbt_foreach(srv->time_tree,
-                         hlt_debug_btm_foreach,
-                         (void *) &btmfd);
-#else
 	btm_rbt_foreach(srv->btm_tree,
 			debug_btm_foreach,
 			(void *) &btmfd);
-#endif
     }
 }
 
@@ -3305,8 +2915,8 @@ debug_callback_timer_foreach_list(ErtsHLTimer *tmr, void *vdfct)
 		      tmr->head.u.arg);
 }
 
-static void
-debug_callback_timer_foreach(ErtsHLTimer *tmr, void *vdfct)
+static int
+debug_callback_timer_foreach(ErtsHLTimer *tmr, void *vdfct, Sint reds)
 {
     ErtsDebugForeachCallbackTimer *dfct
 	= (ErtsDebugForeachCallbackTimer *) vdfct;
@@ -3321,6 +2931,7 @@ debug_callback_timer_foreach(ErtsHLTimer *tmr, void *vdfct)
 	(*dfct->func)(dfct->arg,
 		      tmr->timeout,
 		      tmr->head.u.arg);
+    return 1;
 }
 
 static void
@@ -3368,7 +2979,8 @@ erts_debug_callback_timer_foreach(void (*tclbk)(void *),
 
 	if (srv->yield.root)
 	    debug_callback_timer_foreach(srv->yield.root,
-					 (void *) &dfct);
+					 (void *) &dfct,
+                                         -1);
 
 	time_rbt_foreach(srv->time_tree,
 			 debug_callback_timer_foreach,
@@ -3403,9 +3015,7 @@ st_hdbg_func(ErtsHLTimer *tmr, void *vhdbg)
     }
     ERTS_HLT_ASSERT(tmr->time.tree.u.l.next->time.tree.u.l.prev == tmr);
     ERTS_HLT_ASSERT(tmr->time.tree.u.l.prev->time.tree.u.l.next == tmr);
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
     ERTS_HLT_ASSERT(btm_rbt_lookup(hdbg->srv->btm_tree, ERTS_BTM_HLT2REFN(tmr)) == tmr);
-#endif
 }
 
 static void
@@ -3434,10 +3044,8 @@ tt_hdbg_func(ErtsHLTimer *tmr, void *vhdbg)
 				& ~ERTS_HLT_PFLGS_MASK);
 	ERTS_HLT_ASSERT(tmr == prnt);
     }
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
     if (tmr->head.roflgs & ERTS_TMR_ROFLG_BIF_TMR)
 	ERTS_HLT_ASSERT(btm_rbt_lookup(hdbg->srv->btm_tree, ERTS_BTM_HLT2REFN(tmr)) == tmr);
-#endif
     if (tmr->time.tree.same_time) {
 	ErtsHdbgHLT st_hdbg;
 	st_hdbg.srv = hdbg->srv;
@@ -3503,7 +3111,6 @@ hdbg_chk_srv(ErtsHLTimerService *srv)
 	time_rbt_foreach(srv->time_tree, tt_hdbg_func, (void *) &hdbg);
 	ERTS_HLT_ASSERT(hdbg.found_root);
     }
-#ifndef ERTS_MAGIC_REF_BIF_TIMERS
     if (srv->btm_tree) {
 	ErtsHdbgHLT hdbg;
 	hdbg.srv = srv;
@@ -3512,7 +3119,6 @@ hdbg_chk_srv(ErtsHLTimerService *srv)
 	btm_rbt_foreach(srv->btm_tree, bt_hdbg_func, (void *) &hdbg);
 	ERTS_HLT_ASSERT(hdbg.found_root);
     }
-#endif
 }
 
 #endif /* ERTS_HLT_HARD_DEBUG */
diff --git a/erts/emulator/beam/erl_hl_timer.h b/erts/emulator/beam/erl_hl_timer.h
index e6f5e8b67d..29c873868b 100644
--- a/erts/emulator/beam/erl_hl_timer.h
+++ b/erts/emulator/beam/erl_hl_timer.h
@@ -56,7 +56,7 @@ void erts_cancel_proc_timer(Process *);
 void erts_set_port_timer(Port *, Sint64);
 void erts_cancel_port_timer(Port *);
 Sint64 erts_read_port_timer(Port *);
-int erts_cancel_bif_timers(Process *, ErtsBifTimers **, void **);
+int erts_cancel_bif_timers(Process *, ErtsBifTimers **, void **, int);
 int erts_detach_accessor_bif_timers(Process *, ErtsBifTimers *, void **);
 ErtsHLTimerService *erts_create_timer_service(void);
 void erts_hl_timer_init(void);
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index 99e788c718..547e4064a2 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -78,7 +78,7 @@ const char etp_erts_version[] = ERLANG_VERSION;
 const char etp_otp_release[] = ERLANG_OTP_RELEASE;
 const char etp_compile_date[] = ERLANG_COMPILE_DATE;
 const char etp_arch[] = ERLANG_ARCHITECTURE;
-#ifdef ERTS_ENABLE_KERNEL_POLL
+#if ERTS_ENABLE_KERNEL_POLL
 const int erts_use_kernel_poll = 1;
 const int etp_kernel_poll_support = 1;
 #else
@@ -128,7 +128,7 @@ const Eterm etp_hole_marker = 0;
 
 static int modified_sched_thread_suggested_stack_size = 0;
 
-Eterm erts_init_process_id;
+Eterm erts_init_process_id = ERTS_INVALID_PID;
 
 /*
  * Note about VxWorks: All variables must be initialized by executable code,
@@ -163,7 +163,6 @@ int erts_initialized = 0;
  * Configurable parameters.
  */
 
-Uint display_items;	    	/* no of items to display in traces etc */
 int H_MIN_SIZE;			/* The minimum heap grain */
 int BIN_VH_MIN_SIZE;		/* The minimum binary virtual*/
 int H_MAX_SIZE;			/* The maximum heap size */
@@ -354,6 +353,7 @@ erl_init(int ncpu,
     erts_init_bif();
     erts_init_bif_chksum();
     erts_init_bif_binary();
+    erts_init_bif_guard();
     erts_init_bif_persistent_term();
     erts_init_bif_re();
     erts_init_unicode(); /* after RE to get access to PCRE unicode */
@@ -376,22 +376,37 @@ erl_init(int ncpu,
 }
 
 static Eterm
-erl_first_process_otp(char* modname, void* code, unsigned size, int argc, char** argv)
+
+erl_spawn_system_process(Process* parent, Eterm mod, Eterm func, Eterm args,
+                         ErlSpawnOpts *so)
+{
+    Eterm res;
+    int arity;
+
+    ERTS_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(parent));
+    arity = erts_list_length(args);
+
+    if (erts_find_function(mod, func, arity, erts_active_code_ix()) == NULL) {
+	erts_exit(ERTS_ERROR_EXIT, "No function %T:%T/%i\n", mod, func, arity);
+    }
+
+    so->flags |= SPO_SYSTEM_PROC;
+
+    res = erl_create_process(parent, mod, func, args, so);
+
+    return res;
+}
+
+static Eterm
+erl_first_process_otp(char* mod_name, int argc, char** argv)
 {
     int i;
-    Eterm start_mod;
     Eterm args;
     Eterm res;
     Eterm* hp;
     Process parent;
     ErlSpawnOpts so;
-    Eterm env;
-    
-    start_mod = erts_atom_put((byte *) modname, sys_strlen(modname), ERTS_ATOM_ENC_LATIN1, 1);
-    if (erts_find_function(start_mod, am_start, 2,
-			   erts_active_code_ix()) == NULL) {
-	erts_exit(ERTS_ERROR_EXIT, "No function %s:start/2\n", modname);
-    }
+    Eterm boot_mod;
 
     /*
      * We need a dummy parent process to be able to call erl_create_process().
@@ -399,6 +414,7 @@ erl_first_process_otp(char* modname, void* code, unsigned size, int argc, char**
 
     erts_init_empty_process(&parent);
     erts_proc_lock(&parent, ERTS_PROC_LOCK_MAIN);
+
     hp = HAlloc(&parent, argc*2 + 4);
     args = NIL;
     for (i = argc-1; i >= 0; i--) {
@@ -406,49 +422,76 @@ erl_first_process_otp(char* modname, void* code, unsigned size, int argc, char**
 	args = CONS(hp, new_binary(&parent, (byte*)argv[i], len), args);
 	hp += 2;
     }
-    env = new_binary(&parent, code, size);
+    boot_mod = erts_atom_put((byte *) mod_name, sys_strlen(mod_name),
+                             ERTS_ATOM_ENC_LATIN1, 1);
     args = CONS(hp, args, NIL);
     hp += 2;
-    args = CONS(hp, env, args);
+    args = CONS(hp, boot_mod, args);
+
+    so.flags = erts_default_spo_flags;
+    res = erl_spawn_system_process(&parent, am_erl_init, am_start, args, &so);
+    ASSERT(is_internal_pid(res));
 
-    so.flags = erts_default_spo_flags|SPO_SYSTEM_PROC;
-    res = erl_create_process(&parent, start_mod, am_start, args, &so);
     erts_proc_unlock(&parent, ERTS_PROC_LOCK_MAIN);
     erts_cleanup_empty_process(&parent);
+
     return res;
 }
 
 static Eterm
 erl_system_process_otp(Eterm parent_pid, char* modname, int off_heap_msgq, int prio)
-{
-    Eterm start_mod;
-    Process* parent;
+{ 
+    Process *parent;
     ErlSpawnOpts so;
-    Eterm res;
-
-    start_mod = erts_atom_put((byte *) modname, sys_strlen(modname), ERTS_ATOM_ENC_LATIN1, 1);
-    if (erts_find_function(start_mod, am_start, 0,
-			   erts_active_code_ix()) == NULL) {
-	erts_exit(ERTS_ERROR_EXIT, "No function %s:start/0\n", modname);
-    }
+    Eterm mod, res;
 
     parent = erts_pid2proc(NULL, 0, parent_pid, ERTS_PROC_LOCK_MAIN);
+    mod = erts_atom_put((byte *) modname, sys_strlen(modname),
+                        ERTS_ATOM_ENC_LATIN1, 1);
 
-    so.flags = erts_default_spo_flags|SPO_SYSTEM_PROC|SPO_USE_ARGS;
-    if (off_heap_msgq)
+    so.flags = erts_default_spo_flags|SPO_USE_ARGS;
+
+    if (off_heap_msgq) {
         so.flags |= SPO_OFF_HEAP_MSGQ;
-    so.min_heap_size    = H_MIN_SIZE;
-    so.min_vheap_size   = BIN_VH_MIN_SIZE;
-    so.max_heap_size    = H_MAX_SIZE;
-    so.max_heap_flags   = H_MAX_FLAGS;
-    so.priority         = prio;
-    so.max_gen_gcs      = (Uint16) erts_atomic32_read_nob(&erts_max_gen_gcs);
-    so.scheduler        = 0;
-    res = erl_create_process(parent, start_mod, am_start, NIL, &so);
+    }
+
+    so.min_heap_size  = H_MIN_SIZE;
+    so.min_vheap_size = BIN_VH_MIN_SIZE;
+    so.max_heap_size  = H_MAX_SIZE;
+    so.max_heap_flags = H_MAX_FLAGS;
+    so.priority       = prio;
+    so.max_gen_gcs    = (Uint16) erts_atomic32_read_nob(&erts_max_gen_gcs);
+    so.scheduler      = 0;
+
+    res = erl_spawn_system_process(parent, mod, am_start, NIL, &so);
+    ASSERT(is_internal_pid(res));
+
     erts_proc_unlock(parent, ERTS_PROC_LOCK_MAIN);
+
     return res;
 }
 
+Eterm erts_internal_spawn_system_process_3(BIF_ALIST_3) {
+    Eterm mod, func, args, res;
+    ErlSpawnOpts so;
+
+    mod = BIF_ARG_1;
+    func = BIF_ARG_2;
+    args = BIF_ARG_3;
+
+    ASSERT(is_atom(mod));
+    ASSERT(is_atom(func));
+    ASSERT(erts_list_length(args) >= 0);
+
+    so.flags = erts_default_spo_flags;
+    res = erl_spawn_system_process(BIF_P, mod, func, args, &so);
+
+    if (is_non_value(res)) {
+        BIF_ERROR(BIF_P, so.error_code);
+    }
+
+    BIF_RET(res);
+}
 
 Eterm
 erts_preloaded(Process* p)
@@ -482,7 +525,6 @@ erts_preloaded(Process* p)
 /* static variables that must not change (use same values at restart) */
 static char* program;
 static char* init = "init";
-static char* boot = "boot";
 static int    boot_argc;
 static char** boot_argv;
 
@@ -536,9 +578,6 @@ void erts_usage(void)
     int this_rel = this_rel_num();
     erts_fprintf(stderr, "Usage: %s [flags] [ -- [init_args] ]\n", progname(program));
     erts_fprintf(stderr, "The flags are:\n\n");
-
-    /*    erts_fprintf(stderr, "-# number  set the number of items to be used in traces etc\n"); */
-
     erts_fprintf(stderr, "-a size        suggested stack size in kilo words for threads\n");
     erts_fprintf(stderr, "               in the async-thread pool, valid range is [%d-%d]\n",
 		 ERTS_ASYNC_THREAD_MIN_STACK_SIZE,
@@ -546,18 +585,15 @@ void erts_usage(void)
     erts_fprintf(stderr, "-A number      set number of threads in async thread pool,\n");
     erts_fprintf(stderr, "               valid range is [0-%d]\n",
 		 ERTS_MAX_NO_OF_ASYNC_THREADS);
-
     erts_fprintf(stderr, "-B[c|d|i]      c to have Ctrl-c interrupt the Erlang shell,\n");
     erts_fprintf(stderr, "               d (or no extra option) to disable the break\n");
     erts_fprintf(stderr, "               handler, i to ignore break signals\n");
-
-    /*    erts_fprintf(stderr, "-b func    set the boot function (default boot)\n"); */
-
     erts_fprintf(stderr, "-c bool        enable or disable time correction\n");
     erts_fprintf(stderr, "-C mode        set time warp mode; valid modes are:\n");
     erts_fprintf(stderr, "               no_time_warp|single_time_warp|multi_time_warp\n");
     erts_fprintf(stderr, "-d             don't write a crash dump for internally detected errors\n");
     erts_fprintf(stderr, "               (halt(String) will still produce a crash dump)\n");
+    erts_fprintf(stderr, "-dcg           set the limit for the number of decentralized counter groups\n");
     erts_fprintf(stderr, "-fn[u|a|l]     Control how filenames are interpreted\n");
     erts_fprintf(stderr, "-hms size      set minimum heap size in words (default %d)\n",
 	       H_DEFAULT_SIZE);
@@ -571,7 +607,6 @@ void erts_usage(void)
 	       erts_pd_initial_size);
     erts_fprintf(stderr, "-hmqd  val     set default message queue data flag for processes,\n");
     erts_fprintf(stderr, "               valid values are: off_heap | on_heap\n");
-
     erts_fprintf(stderr, "-IOp number    set number of pollsets to be used to poll for I/O,\n");
     erts_fprintf(stderr, "               This value has to be equal or smaller than the\n");
     erts_fprintf(stderr, "               number of poll threads. If the current platform\n");
@@ -582,9 +617,7 @@ void erts_usage(void)
     erts_fprintf(stderr, "               number of poll threads.");
     erts_fprintf(stderr, "-IOPt number   set number of threads to be used to poll for I/O\n");
     erts_fprintf(stderr, "               as a percentage of the number of schedulers.");
-
-    /*    erts_fprintf(stderr, "-i module  set the boot module (default init)\n"); */
-
+    erts_fprintf(stderr, "-i module      set the boot module (default init)\n");
     erts_fprintf(stderr, "-n[s|a|d]      Control behavior of signals to ports\n");
     erts_fprintf(stderr, "               Note that this flag is deprecated!\n");
     erts_fprintf(stderr, "-M<X> <Y>      memory allocator switches,\n");
@@ -599,7 +632,6 @@ void erts_usage(void)
     erts_fprintf(stderr, "-R number      set compatibility release number,\n");
     erts_fprintf(stderr, "               valid range [%d-%d]\n",
 		 this_rel-2, this_rel);
-
     erts_fprintf(stderr, "-r             force ets memory block to be moved on realloc\n");
     erts_fprintf(stderr, "-rg amount     set reader groups limit\n");
     erts_fprintf(stderr, "-sbt type      set scheduler bind type, valid types are:\n");
@@ -670,9 +702,7 @@ void erts_usage(void)
     erts_fprintf(stderr, "-T number      set modified timing level, valid range is [0-%d]\n",
 		 ERTS_MODIFIED_TIMING_LEVELS-1);
     erts_fprintf(stderr, "-V             print Erlang version\n");
-
     erts_fprintf(stderr, "-v             turn on chatty mode (GCs will be reported etc)\n");
-
     erts_fprintf(stderr, "-W<i|w|e>      set error logger warnings mapping,\n");
     erts_fprintf(stderr, "               see error_logger documentation for details\n");
     erts_fprintf(stderr, "-zdbbl size    set the distribution buffer busy limit in kilobytes\n");
@@ -756,6 +786,8 @@ early_init(int *argc, char **argv) /*
     int dirty_io_scheds;
     int max_reader_groups;
     int reader_groups;
+    int max_decentralized_counter_groups;
+    int decentralized_counter_groups;
     char envbuf[21]; /* enough for any 64-bit integer */
     size_t envbufsz;
 
@@ -763,7 +795,6 @@ early_init(int *argc, char **argv) /*
 
     erts_sched_compact_load = 1;
     erts_printf_eterm_func = erts_printf_term;
-    display_items = 200;
     erts_backtrace_depth = DEFAULT_BACKTRACE_SIZE;
     erts_async_max_threads = ERTS_DEFAULT_NO_ASYNC_THREADS;
     erts_async_thread_suggested_stack_size = ERTS_ASYNC_THREAD_MIN_STACK_SIZE;
@@ -776,7 +807,8 @@ early_init(int *argc, char **argv) /*
 
     erts_initialized = 0;
 
-    erts_pre_early_init_cpu_topology(&max_reader_groups,
+    erts_pre_early_init_cpu_topology(&max_decentralized_counter_groups,
+                                     &max_reader_groups,
 				     &ncpu,
 				     &ncpuonln,
 				     &ncpuavail);
@@ -837,6 +869,24 @@ early_init(int *argc, char **argv) /*
 	    }
 	    if (argv[i][0] == '-') {
 		switch (argv[i][1]) {
+		case 'd': {
+		    char *sub_param = argv[i]+2;
+		    if (has_prefix("cg", sub_param)) {
+			char *arg = get_arg(sub_param+2, argv[i+1], &i);
+			if (sscanf(arg, "%d", &max_decentralized_counter_groups) != 1) {
+			    erts_fprintf(stderr,
+					 "bad decentralized counter groups limit: %s\n", arg);
+			    erts_usage();
+			}
+			if (max_decentralized_counter_groups < 0) {
+			    erts_fprintf(stderr,
+					 "bad decentralized counter groups limit: %d\n",
+					 max_decentralized_counter_groups);
+			    erts_usage();
+			}
+		    }
+		    break;
+		}
 		case 'r': {
 		    char *sub_param = argv[i]+2;
 		    if (has_prefix("g", sub_param)) {
@@ -1158,8 +1208,10 @@ early_init(int *argc, char **argv) /*
     erts_early_init_cpu_topology(no_schedulers,
 				 &max_main_threads,
 				 max_reader_groups,
-				 &reader_groups);
-
+				 &reader_groups,
+                                 max_decentralized_counter_groups,
+                                 &decentralized_counter_groups);
+    erts_flxctr_setup(decentralized_counter_groups);
     {
 	erts_thr_late_init_data_t elid = ERTS_THR_LATE_INIT_DATA_DEF_INITER;
 	elid.mem.std.alloc = ethr_std_alloc;
@@ -1270,25 +1322,9 @@ erl_start(int argc, char **argv)
 
 	    /*
 	     * NOTE: -M flags are handled (and removed from argv) by
-	     * erts_alloc_init(). 
-	     *
-	     * The -d, -m, -S, -t, and -T flags was removed in
-	     * Erlang 5.3/OTP R9C.
-	     *
-	     * -S, and -T has been reused in Erlang 5.5/OTP R11B.
-	     *
-	     * -d has been reused in a patch R12B-4.
+	     * erts_alloc_init().
 	     */
 
-	case '#' :
-	    arg = get_arg(argv[i]+2, argv[i+1], &i);
-	    if ((display_items = atoi(arg)) == 0) {
-		erts_fprintf(stderr, "bad display items%s\n", arg);
-		erts_usage();
-	    }
-	    VERBOSE(DEBUG_SYSTEM,
-                    ("using display items %d\n",display_items));
-	    break;
 	case 'p':
 	    if (!sys_strncmp(argv[i],"-pc",3)) {
 		int printable_chars = ERL_PRINTABLE_CHARACTERS_LATIN1;
@@ -1567,11 +1603,6 @@ erl_start(int argc, char **argv)
 	    init = get_arg(argv[i]+2, argv[i+1], &i);
 	    break;
 
-	case 'b':
-	    /* define name of initial function */
-	    boot = get_arg(argv[i]+2, argv[i+1], &i);
-	    break;
-
 	case 'B':
 	  if (argv[i][2] == 'i')          /* +Bi */
 	    ignore_break = 1;
@@ -2257,8 +2288,8 @@ erl_start(int argc, char **argv)
 
     erts_initialized = 1;
 
-    erts_init_process_id = erl_first_process_otp("otp_ring0", NULL, 0,
-                                                 boot_argc, boot_argv);
+    erts_init_process_id = erl_first_process_otp(init, boot_argc, boot_argv);
+    ASSERT(erts_init_process_id != ERTS_INVALID_PID);
 
     {
 	/*
diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c
index 1416c5f96c..3aab4828cc 100644
--- a/erts/emulator/beam/erl_lock_check.c
+++ b/erts/emulator/beam/erl_lock_check.c
@@ -42,6 +42,7 @@
 #include "erl_term.h"
 #include "erl_threads.h"
 #include "erl_atom_table.h"
+#include "erl_utils.h"
 
 typedef struct {
     char *name;
@@ -91,6 +92,8 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"db_tab",				"address"		},
     {	"db_tab_fix",				"address"		},
     {	"db_hash_slot",				"address"		},
+    {	"erl_db_catree_base_node",		NULL		        },
+    {	"erl_db_catree_route_node",		"index"		        },
     {	"resource_monitors",			"address"	        },
     {   "driver_list",                          NULL                    },
     {	"proc_msgq",				"pid"			},
@@ -193,6 +196,12 @@ struct lc_locked_lock_t_ {
     unsigned int line;
     erts_lock_flags_t flags;
     erts_lock_options_t taken_options;
+    /*
+     * Pointer back to the lock instance if it exists or NULL for proc locks.
+     * If set, we use it to allow trylock of other lock instance
+     * but with identical lock order as an already locked lock.
+     */
+    erts_lc_lock_t *lck;
 };
 
 typedef struct {
@@ -406,6 +415,10 @@ new_locked_lock(lc_thread_t* thr,
     ll->line = line;
     ll->flags = lck->flags;
     ll->taken_options = options;
+    if ((lck->flags & ERTS_LOCK_FLAGS_MASK_TYPE) == ERTS_LOCK_FLAGS_TYPE_PROCLOCK)
+        ll->lck = NULL;
+    else
+        ll->lck = lck;
     return ll;
 }
 
@@ -709,6 +722,14 @@ erts_lc_get_lock_order_id(char *name)
     return (Sint16) -1;
 }
 
+static int
+lc_is_term_order(Sint16 id)
+{
+    return erts_lock_order[id].internal_order != NULL
+        && sys_strcmp(erts_lock_order[id].internal_order, "term") == 0;
+}
+
+
 static int compare_locked_by_id(lc_locked_lock_t *locked_lock, erts_lc_lock_t *comparand)
 {
     if(locked_lock->id < comparand->id) {
@@ -720,18 +741,23 @@ static int compare_locked_by_id(lc_locked_lock_t *locked_lock, erts_lc_lock_t *c
     return 0;
 }
 
-static int compare_locked_by_id_extra(lc_locked_lock_t *locked_lock, erts_lc_lock_t *comparand)
+static int compare_locked_by_id_extra(lc_locked_lock_t *ll, erts_lc_lock_t *comparand)
 {
-    int order = compare_locked_by_id(locked_lock, comparand);
+    int order = compare_locked_by_id(ll, comparand);
 
     if(order) {
         return order;
-    } else if(locked_lock->extra < comparand->extra) {
+    }
+    if (ll->flags & ERTS_LOCK_FLAGS_PROPERTY_TERM_ORDER) {
+        ASSERT(!is_header(ll->extra) && !is_header(comparand->extra));
+        return CMP(ll->extra, comparand->extra);
+    }
+
+    if(ll->extra < comparand->extra) {
         return -1;
-    } else if(locked_lock->extra > comparand->extra) {
+    } else if(ll->extra > comparand->extra) {
         return 1;
     }
-
     return 0;
 }
 
@@ -970,7 +996,8 @@ erts_lc_trylock_force_busy_flg(erts_lc_lock_t *lck, erts_lock_options_t options)
 	return 0;
     }
     else {
-	lc_locked_lock_t *tl_lck;
+        lc_locked_lock_t *ll;
+        int order;
 
 	ASSERT(thr->locked.last);
 
@@ -979,25 +1006,25 @@ erts_lc_trylock_force_busy_flg(erts_lc_lock_t *lck, erts_lock_options_t options)
 	    type_order_violation("trylocking ", thr, lck);
 #endif
 
-	if (thr->locked.last->id < lck->id
-	    || (thr->locked.last->id == lck->id
-		&& thr->locked.last->extra < lck->extra))
-	    return 0;
+        ll = thr->locked.last;
+        order = compare_locked_by_id_extra(ll, lck);
+
+	if (order < 0)
+            return 0;
 
 	/*
-	 * Lock order violation
+	 * TryLock order violation
 	 */
 
-
-	/* Check that we are not trying to lock this lock twice */
-	for (tl_lck = thr->locked.last; tl_lck; tl_lck = tl_lck->prev) {
-	    if (tl_lck->id < lck->id
-		|| (tl_lck->id == lck->id && tl_lck->extra <= lck->extra)) {
-		if (tl_lck->id == lck->id && tl_lck->extra == lck->extra)
-		    lock_twice("Trylocking", thr, lck, options);
-		break;
-	    }
-	}
+        /* Check that we are not trying to lock this lock twice */
+        do {
+            if (order == 0 && (ll->lck == lck || !ll->lck))
+                lock_twice("Trylocking", thr, lck, options);
+            ll = ll->prev;
+            if (!ll)
+                break;
+            order = compare_locked_by_id_extra(ll, lck);
+        } while (order >= 0);
 
 #ifndef ERTS_LC_ALLWAYS_FORCE_BUSY_TRYLOCK_ON_LOCK_ORDER_VIOLATION
 	/* We only force busy if a lock order violation would occur
@@ -1044,10 +1071,10 @@ void erts_lc_trylock_flg_x(int locked, erts_lc_lock_t *lck, erts_lock_options_t
 #endif
 
 	for (tl_lck = thr->locked.last; tl_lck; tl_lck = tl_lck->prev) {
-	    if (tl_lck->id < lck->id
-		|| (tl_lck->id == lck->id && tl_lck->extra <= lck->extra)) {
-		if (tl_lck->id == lck->id && tl_lck->extra == lck->extra)
-		    lock_twice("Trylocking", thr, lck, options);
+            int order = compare_locked_by_id_extra(tl_lck, lck);
+	    if (order <= 0) {
+                if (order == 0 && (tl_lck->lck == lck || !tl_lck->lck))
+                    lock_twice("Trylocking", thr, lck, options);
 		if (locked) {
 		    ll->next = tl_lck->next;
 		    ll->prev = tl_lck;
@@ -1089,10 +1116,10 @@ void erts_lc_require_lock_flg(erts_lc_lock_t *lck, erts_lock_options_t options,
 	for (l_lck2 = thr->required.last;
 	     l_lck2;
 	     l_lck2 = l_lck2->prev) {
-	    if (l_lck2->id < lck->id
-		|| (l_lck2->id == lck->id && l_lck2->extra < lck->extra))
+            int order = compare_locked_by_id_extra(l_lck2, lck);
+	    if (order < 0)
 		break;
-	    else if (l_lck2->id == lck->id && l_lck2->extra == lck->extra)
+	    if (order == 0)
 		require_twice(thr, lck);
 	}
 	if (!l_lck2) {
@@ -1150,6 +1177,7 @@ void erts_lc_lock_flg_x(erts_lc_lock_t *lck, erts_lock_options_t options,
 {
     lc_thread_t *thr;
     lc_locked_lock_t *new_ll;
+    int order;
 
     if (lck->inited != ERTS_LC_INITITALIZED)
 	uninitialized_lock();
@@ -1165,10 +1193,10 @@ void erts_lc_lock_flg_x(erts_lc_lock_t *lck, erts_lock_options_t options,
 	thr->locked.last = thr->locked.first = new_ll;
         ASSERT(0 < lck->id && lck->id < ERTS_LOCK_ORDER_SIZE);
         thr->matrix.m[lck->id][0] = 1;
+        return;
     }
-    else if (thr->locked.last->id < lck->id
-	     || (thr->locked.last->id == lck->id
-		 && thr->locked.last->extra < lck->extra)) {
+    order = compare_locked_by_id_extra(thr->locked.last, lck);
+    if (order < 0) {
         lc_locked_lock_t* ll;
 	if (LOCK_IS_TYPE_ORDER_VIOLATION(lck->flags, thr->locked.last->flags)) {
 	    type_order_violation("locking ", thr, lck);
@@ -1186,7 +1214,7 @@ void erts_lc_lock_flg_x(erts_lc_lock_t *lck, erts_lock_options_t options,
 	thr->locked.last->next = new_ll;
 	thr->locked.last = new_ll;
     }
-    else if (thr->locked.last->id == lck->id && thr->locked.last->extra == lck->extra)
+    else if (order == 0)
 	lock_twice("Locking", thr, lck, options);
     else
 	lock_order_violation(thr, lck);
@@ -1298,7 +1326,6 @@ void
 erts_lc_init_lock(erts_lc_lock_t *lck, char *name, erts_lock_flags_t flags)
 {
     lck->id = erts_lc_get_lock_order_id(name);
-
     lck->extra = (UWord) &lck->extra;
     ASSERT(is_not_immed(lck->extra));
     lck->flags = flags;
@@ -1311,8 +1338,13 @@ erts_lc_init_lock_x(erts_lc_lock_t *lck, char *name, erts_lock_flags_t flags, Et
 {
     lck->id = erts_lc_get_lock_order_id(name);
     lck->extra = extra;
-    ASSERT(is_immed(lck->extra));
     lck->flags = flags;
+    if (lc_is_term_order(lck->id)) {
+        lck->flags |= ERTS_LOCK_FLAGS_PROPERTY_TERM_ORDER;
+        ASSERT(!is_header(lck->extra));
+    }
+    else
+        ASSERT(is_immed(lck->extra));
     lck->taken_options = 0;
     lck->inited = ERTS_LC_INITITALIZED;
 }
diff --git a/erts/emulator/beam/erl_lock_check.h b/erts/emulator/beam/erl_lock_check.h
index d10e32985a..b32f27d9f9 100644
--- a/erts/emulator/beam/erl_lock_check.h
+++ b/erts/emulator/beam/erl_lock_check.h
@@ -104,7 +104,7 @@ Eterm erts_lc_dump_graph(void);
 
 #define erts_lc_lock(lck) erts_lc_lock_x(lck,__FILE__,__LINE__)
 #define erts_lc_trylock(res,lck) erts_lc_trylock_x(res,lck,__FILE__,__LINE__)
-#define erts_lc_lock_flg(lck) erts_lc_lock_flg_x(lck,__FILE__,__LINE__)
-#define erts_lc_trylock_flg(res,lck) erts_lc_trylock_flg_x(res,lck,__FILE__,__LINE__)
+#define erts_lc_lock_flg(lck,flg) erts_lc_lock_flg_x(lck,flg,__FILE__,__LINE__)
+#define erts_lc_trylock_flg(res,lck,flg) erts_lc_trylock_flg_x(res,lck,flg,__FILE__,__LINE__)
 
 #endif /* #ifndef ERTS_LOCK_CHECK_H__ */
diff --git a/erts/emulator/beam/erl_lock_count.h b/erts/emulator/beam/erl_lock_count.h
index 89d95a73cf..0d47b16e0b 100644
--- a/erts/emulator/beam/erl_lock_count.h
+++ b/erts/emulator/beam/erl_lock_count.h
@@ -532,7 +532,7 @@ ERTS_GLB_INLINE
 void lcnt_dec_lock_state__(ethr_atomic_t *l_state) {
     ethr_sint_t state = ethr_atomic_dec_read_acqb(l_state);
 
-    /* We can not assume that state is >= -1 here; unlock and unacquire might
+    /* We cannot assume that state is >= -1 here; unlock and unacquire might
      * bring it below -1 and race to increment it back. */
 
     if(state < 0) {
diff --git a/erts/emulator/beam/erl_lock_flags.h b/erts/emulator/beam/erl_lock_flags.h
index d711f69456..2db133b598 100644
--- a/erts/emulator/beam/erl_lock_flags.h
+++ b/erts/emulator/beam/erl_lock_flags.h
@@ -28,15 +28,17 @@
 
 /* Property/category are bitfields to simplify their use in masks. */
 #define ERTS_LOCK_FLAGS_MASK_CATEGORY (0xFFC0)
-#define ERTS_LOCK_FLAGS_MASK_PROPERTY (0x0030)
+#define ERTS_LOCK_FLAGS_MASK_PROPERTY (0x0038)
 
 /* Type is a plain number. */
-#define ERTS_LOCK_FLAGS_MASK_TYPE     (0x000F)
+#define ERTS_LOCK_FLAGS_MASK_TYPE     (0x0007)
 
 #define ERTS_LOCK_FLAGS_TYPE_SPINLOCK (1)
 #define ERTS_LOCK_FLAGS_TYPE_MUTEX    (2)
 #define ERTS_LOCK_FLAGS_TYPE_PROCLOCK (3)
 
+/* Lock checker use real term order instead of raw word compare */
+#define ERTS_LOCK_FLAGS_PROPERTY_TERM_ORDER (1 << 3)
 /* "Static" guarantees that the lock will never be destroyed once created. */
 #define ERTS_LOCK_FLAGS_PROPERTY_STATIC     (1 << 4)
 #define ERTS_LOCK_FLAGS_PROPERTY_READ_WRITE (1 << 5)
diff --git a/erts/emulator/beam/erl_map.c b/erts/emulator/beam/erl_map.c
index cba17d3e6a..62dd85e425 100644
--- a/erts/emulator/beam/erl_map.c
+++ b/erts/emulator/beam/erl_map.c
@@ -125,15 +125,20 @@ BIF_RETTYPE map_size_1(BIF_ALIST_1) {
 	flatmap_t *mp = (flatmap_t*)flatmap_val(BIF_ARG_1);
 	BIF_RET(make_small(flatmap_get_size(mp)));
     } else if (is_hashmap(BIF_ARG_1)) {
-	Eterm *head, *hp, res;
-	Uint size, hsz=0;
+	Eterm *head;
+	Uint size;
 
 	head = hashmap_val(BIF_ARG_1);
 	size = head[1];
-	(void) erts_bld_uint(NULL, &hsz, size);
-	hp = HAlloc(BIF_P, hsz);
-	res = erts_bld_uint(&hp, NULL, size);
-	BIF_RET(res);
+
+        /*
+         * As long as a small has 28 bits (on a 32-bit machine) for
+         * the integer itself, it is impossible to build a map whose
+         * size would not fit in a small. Add an assertion in case we
+         * ever decreases the number of bits in a small.
+         */
+        ASSERT(IS_USMALL(0, size));
+        BIF_RET(make_small(size));
     }
 
     BIF_P->fvalue = BIF_ARG_1;
@@ -475,7 +480,7 @@ Eterm erts_hashmap_from_array(ErtsHeapFactory* factory, Eterm *leafs, Uint n,
 
 Eterm erts_map_from_ks_and_vs(ErtsHeapFactory *factory, Eterm *ks0, Eterm *vs0, Uint n)
 {
-    if (n < MAP_SMALL_MAP_LIMIT) {
+    if (n <= MAP_SMALL_MAP_LIMIT) {
         Eterm *ks, *vs, *hp;
 	flatmap_t *mp;
 	Eterm keys;
@@ -1505,25 +1510,6 @@ int hashmap_key_hash_cmp(Eterm* ap, Eterm* bp)
     return ap ? -1 : 1;
 }
 
-/* maps:new/0 */
-
-BIF_RETTYPE maps_new_0(BIF_ALIST_0) {
-    Eterm* hp;
-    Eterm tup;
-    flatmap_t *mp;
-
-    hp    = HAlloc(BIF_P, (MAP_HEADER_FLATMAP_SZ + 1));
-    tup   = make_tuple(hp);
-    *hp++ = make_arityval(0);
-
-    mp    = (flatmap_t*)hp;
-    mp->thing_word = MAP_HEADER_FLATMAP;
-    mp->size = 0;
-    mp->keys = tup;
-
-    BIF_RET(make_flatmap(mp));
-}
-
 /* maps:put/3 */
 
 BIF_RETTYPE maps_put_3(BIF_ALIST_3) {
@@ -1707,11 +1693,16 @@ int erts_maps_update(Process *p, Eterm key, Eterm value, Eterm map, Eterm *res)
 	return 0;
 
 found_key:
-	*hp++ = value;
-	vs++;
-	if (++i < n)
-	    sys_memcpy(hp, vs, (n - i)*sizeof(Eterm));
-	*res = make_flatmap(shp);
+        if(*vs == value) {
+            HRelease(p, shp + MAP_HEADER_FLATMAP_SZ + n, shp);
+            *res = map;
+        } else {
+	    *hp++ = value;
+	    vs++;
+	    if (++i < n)
+	       sys_memcpy(hp, vs, (n - i)*sizeof(Eterm));
+	    *res = make_flatmap(shp);
+        }
 	return 1;
     }
 
@@ -1767,9 +1758,7 @@ Eterm erts_maps_put(Process *p, Eterm key, Eterm value, Eterm map) {
 	if (is_immed(key)) {
 	    for( i = 0; i < n; i ++) {
 		if (ks[i] == key) {
-		    *hp++ = value;
-		    vs++;
-		    c = 1;
+                    goto found_key;
 		} else {
 		    *hp++ = *vs++;
 		}
@@ -1777,18 +1766,13 @@ Eterm erts_maps_put(Process *p, Eterm key, Eterm value, Eterm map) {
 	} else {
 	    for( i = 0; i < n; i ++) {
 		if (EQ(ks[i], key)) {
-		    *hp++ = value;
-		    vs++;
-		    c = 1;
+		    goto found_key;
 		} else {
 		    *hp++ = *vs++;
 		}
 	    }
 	}
 
-	if (c)
-	    return res;
-
 	/* the map will grow */
 
 	if (n >= MAP_SMALL_MAP_LIMIT) {
@@ -1843,6 +1827,18 @@ Eterm erts_maps_put(Process *p, Eterm key, Eterm value, Eterm map) {
 	 */
 	*shp = make_pos_bignum_header(0);
 	return res;
+
+found_key:
+        if(*vs == value) {
+            HRelease(p, shp + MAP_HEADER_FLATMAP_SZ + n, shp);
+            return map;
+        } else {
+            *hp++ = value;
+            vs++;
+            if (++i < n)
+               sys_memcpy(hp, vs, (n - i)*sizeof(Eterm));
+            return res;
+        }
     }
     ASSERT(is_hashmap(map));
 
diff --git a/erts/emulator/beam/erl_message.c b/erts/emulator/beam/erl_message.c
index a3274d7443..1bebf6efe2 100644
--- a/erts/emulator/beam/erl_message.c
+++ b/erts/emulator/beam/erl_message.c
@@ -181,7 +181,7 @@ erts_cleanup_offheap(ErlOffHeap *offheap)
 	    break;
 	default:
 	    ASSERT(is_external_header(u.hdr->thing_word));
-	    erts_deref_node_entry(u.ext->node);
+	    erts_deref_node_entry(u.ext->node, make_boxed(u.ep));
 	    break;
 	}
     }
@@ -201,34 +201,44 @@ free_message_buffer(ErlHeapFragment* bp)
     }while (bp != NULL);
 }
 
+static void
+erts_cleanup_message(ErtsMessage *mp)
+{
+    ErlHeapFragment *bp;
+    if (ERTS_SIG_IS_EXTERNAL_MSG(mp) || ERTS_SIG_IS_NON_MSG(mp)) {
+        ErtsDistExternal *edep = erts_proc_sig_get_external(mp);
+        if (edep) {
+            erts_free_dist_ext_copy(edep);
+            if (mp->data.heap_frag == &mp->hfrag) {
+                ASSERT(ERTS_SIG_IS_EXTERNAL_MSG(mp));
+                mp->data.heap_frag = ERTS_MSG_COMBINED_HFRAG;
+            }
+        }
+    }
+
+    if (ERTS_SIG_IS_MSG(mp) && mp->data.attached != ERTS_MSG_COMBINED_HFRAG) {
+        bp = mp->data.heap_frag;
+    } else {
+        /* All non msg signals are combined HFRAG messages,
+           but we overwrite the mp->data field with the
+           nm_signal queue ptr so have to fix that here
+           before freeing it. */
+        mp->data.attached = ERTS_MSG_COMBINED_HFRAG;
+        bp = mp->hfrag.next;
+        erts_cleanup_offheap(&mp->hfrag.off_heap);
+    }
+
+    if (bp)
+        free_message_buffer(bp);
+}
+
 void
 erts_cleanup_messages(ErtsMessage *msgp)
 {
     ErtsMessage *mp = msgp;
     while (mp) {
 	ErtsMessage *fmp;
-	ErlHeapFragment *bp;
-	if (ERTS_SIG_IS_EXTERNAL_MSG(mp)) {
-	    if (is_not_immed(ERL_MESSAGE_TOKEN(mp))) {
-		bp = (ErlHeapFragment *) mp->data.dist_ext->ext_endp;
-		erts_cleanup_offheap(&bp->off_heap);
-	    }
-	    if (mp->data.dist_ext)
-		erts_free_dist_ext_copy(mp->data.dist_ext);
-	}
-        else {
-	    if (ERTS_SIG_IS_INTERNAL_MSG(mp)
-                && mp->data.attached != ERTS_MSG_COMBINED_HFRAG) {
-		bp = mp->data.heap_frag;
-            }
-	    else {
-                mp->data.attached = ERTS_MSG_COMBINED_HFRAG;
-		bp = mp->hfrag.next;
-		erts_cleanup_offheap(&mp->hfrag.off_heap);
-	    }
-	    if (bp)
-		free_message_buffer(bp);
-	}
+	erts_cleanup_message(mp);
 	fmp = mp;
 	mp = mp->next;
 	erts_free_message(fmp);
@@ -260,6 +270,7 @@ void
 erts_queue_dist_message(Process *rcvr,
 			ErtsProcLocks rcvr_locks,
 			ErtsDistExternal *dist_ext,
+                        ErlHeapFragment *hfrag,
 			Eterm token,
                         Eterm from)
 {
@@ -268,8 +279,26 @@ erts_queue_dist_message(Process *rcvr,
 
     ERTS_LC_ASSERT(rcvr_locks == erts_proc_lc_my_proc_locks(rcvr));
 
-    mp = erts_alloc_message(0, NULL);
-    mp->data.dist_ext = dist_ext;
+    if (hfrag) {
+        /* Fragmented message, allocate a message reference */
+        mp = erts_alloc_message(0, NULL);
+        mp->data.heap_frag = hfrag;
+    } else {
+        /* Un-fragmented message, allocate space for
+           token and dist_ext in message. */
+        Uint dist_ext_sz = erts_dist_ext_size(dist_ext) / sizeof(Eterm);
+        Uint token_sz = size_object(token);
+        Uint sz = token_sz + dist_ext_sz;
+        Eterm *hp;
+
+        mp = erts_alloc_message(sz, &hp);
+        mp->data.heap_frag = &mp->hfrag;
+        mp->hfrag.used_size = token_sz;
+
+        erts_make_dist_ext_copy(dist_ext, erts_get_dist_ext(mp->data.heap_frag));
+
+        token = copy_struct(token, token_sz, &hp, &mp->data.heap_frag->off_heap);
+    }
 
     ERL_MESSAGE_FROM(mp) = dist_ext->dep->sysname;
     ERL_MESSAGE_TERM(mp) = THE_NON_VALUE;
@@ -493,25 +522,27 @@ Uint
 erts_msg_attached_data_size_aux(ErtsMessage *msg)
 {
     Sint sz;
-    ASSERT(is_non_value(ERL_MESSAGE_TERM(msg)));
-    ASSERT(msg->data.dist_ext);
-    ASSERT(msg->data.dist_ext->heap_size < 0);
-
-    sz = erts_decode_dist_ext_size(msg->data.dist_ext);
-    if (sz < 0) {
-	/* Bad external
-	 * We leave the message intact in this case as it's not worth the trouble
-	 * to make all callers remove it from queue. It will be detected again
-	 * and removed from message queue later anyway.
-	 */
-	return 0;
-    }
+    ErtsDistExternal *edep = erts_get_dist_ext(msg->data.heap_frag);
+    ASSERT(ERTS_SIG_IS_EXTERNAL_MSG(msg));
 
-    msg->data.dist_ext->heap_size = sz;
-    if (is_not_nil(msg->m[1])) {
-	ErlHeapFragment *heap_frag;
-	heap_frag = erts_dist_ext_trailer(msg->data.dist_ext);
-	sz += heap_frag->used_size;
+    if (edep->heap_size < 0) {
+
+        sz = erts_decode_dist_ext_size(edep, 1, 1);
+        if (sz < 0) {
+            /* Bad external
+             * We leave the message intact in this case as it's not worth the trouble
+             * to make all callers remove it from queue. It will be detected again
+             * and removed from message queue later anyway.
+             */
+            return 0;
+        }
+
+        edep->heap_size = sz;
+    } else {
+        sz = edep->heap_size;
+    }
+    if (is_not_nil(ERL_MESSAGE_TOKEN(msg))) {
+	sz += msg->data.heap_frag->used_size;
     }
     return sz;
 }
@@ -532,9 +563,7 @@ erts_try_alloc_message_on_heap(Process *pp,
 
     if ((*psp) & ERTS_PSFLGS_VOLATILE_HEAP)
 	goto in_message_fragment;
-    else if (
-	*plp & ERTS_PROC_LOCK_MAIN
-	) {
+    else if (*plp & ERTS_PROC_LOCK_MAIN) {
     try_on_heap:
 	if (((*psp) & ERTS_PSFLGS_VOLATILE_HEAP)
 	    || (pp->flags & F_DISABLE_GC)
@@ -747,6 +776,13 @@ erts_send_message(Process* sender,
 #endif
 
     erts_queue_proc_message(sender, receiver, *receiver_locks, mp, message);
+
+    if (msize > ERTS_MSG_COPY_WORDS_PER_REDUCTION) {
+        Uint reds = msize / ERTS_MSG_COPY_WORDS_PER_REDUCTION;
+        if (reds > CONTEXT_REDS)
+            reds = CONTEXT_REDS;
+        BUMP_REDS(sender, (int) reds);
+    }
 }
 
 
@@ -1101,84 +1137,28 @@ change_to_off_heap:
     return res;
 }
 
-int
-erts_decode_dist_message(Process *proc, ErtsProcLocks proc_locks,
-			 ErtsMessage *msgp, int force_off_heap)
+void erts_factory_proc_init(ErtsHeapFactory* factory, Process* p)
 {
-    ErtsHeapFactory factory;
-    Eterm msg;
-    ErlHeapFragment *bp;
-    Sint need;
-    int decode_in_heap_frag;
-
-    decode_in_heap_frag = (force_off_heap
-			   || !(proc_locks & ERTS_PROC_LOCK_MAIN)
-			   || (proc->flags & F_OFF_HEAP_MSGQ));
-
-    if (msgp->data.dist_ext->heap_size >= 0)
-	need = msgp->data.dist_ext->heap_size;
-    else {
-	need = erts_decode_dist_ext_size(msgp->data.dist_ext);
-	if (need < 0) {
-	    /* bad msg; remove it... */
-	    if (is_not_immed(ERL_MESSAGE_TOKEN(msgp))) {
-		bp = erts_dist_ext_trailer(msgp->data.dist_ext);
-		erts_cleanup_offheap(&bp->off_heap);
-	    }
-	    erts_free_dist_ext_copy(msgp->data.dist_ext);
-	    msgp->data.dist_ext = NULL;
-	    return 0;
-	}
-
-	msgp->data.dist_ext->heap_size = need;
-    }
-
-    if (is_not_immed(ERL_MESSAGE_TOKEN(msgp))) {
-	bp = erts_dist_ext_trailer(msgp->data.dist_ext);
-	need += bp->used_size;
-    }
-
-    if (decode_in_heap_frag)
-	erts_factory_heap_frag_init(&factory, new_message_buffer(need));
-    else
-	erts_factory_proc_prealloc_init(&factory, proc, need);
-
-    ASSERT(msgp->data.dist_ext->heap_size >= 0);
-    if (is_not_immed(ERL_MESSAGE_TOKEN(msgp))) {
-	ErlHeapFragment *heap_frag;
-	heap_frag = erts_dist_ext_trailer(msgp->data.dist_ext);
-	ERL_MESSAGE_TOKEN(msgp) = copy_struct(ERL_MESSAGE_TOKEN(msgp),
-					      heap_frag->used_size,
-					      &factory.hp,
-					      factory.off_heap);
-	erts_cleanup_offheap(&heap_frag->off_heap);
-    }
-
-    msg = erts_decode_dist_ext(&factory, msgp->data.dist_ext);
-    ERL_MESSAGE_TERM(msgp) = msg;
-    erts_free_dist_ext_copy(msgp->data.dist_ext);
-    msgp->data.attached = NULL;
-
-    if (is_non_value(msg)) {
-	erts_factory_undo(&factory);
-	return 0;
-    }
-
-    erts_factory_trim_and_close(&factory, msgp->m,
-				ERL_MESSAGE_REF_ARRAY_SZ);
-
-    ASSERT(!msgp->data.heap_frag);
-
-    if (decode_in_heap_frag)
-	msgp->data.heap_frag = factory.heap_frags;
-
-    return 1;
-}
+    /* This function does not use HAlloc to allocate on the heap
+       as we do not want to use INIT_HEAP_MEM on the allocated
+       heap as that completely destroys the DEBUG emulators
+       performance. */
+    ErlHeapFragment *bp = p->mbuf;
+    factory->mode     = FACTORY_HALLOC;
+    factory->p        = p;
+    factory->hp_start = HEAP_TOP(p);
+    factory->hp       = factory->hp_start;
+    factory->hp_end   = HEAP_LIMIT(p);
+    factory->off_heap = &p->off_heap;
+    factory->message  = NULL;
+    factory->off_heap_saved.first    = p->off_heap.first;
+    factory->off_heap_saved.overhead = p->off_heap.overhead;
+    factory->heap_frags_saved = bp;
+    factory->heap_frags_saved_used = bp ? bp->used_size : 0;
+    factory->heap_frags = NULL; /* not used */
+    factory->alloc_type = 0; /* not used */
 
-void erts_factory_proc_init(ErtsHeapFactory* factory,
-			    Process* p)
-{
-    erts_factory_proc_prealloc_init(factory, p, HEAP_LIMIT(p) - HEAP_TOP(p));
+    HEAP_TOP(p) = HEAP_LIMIT(p);
 }
 
 void erts_factory_proc_prealloc_init(ErtsHeapFactory* factory,
@@ -1235,7 +1215,7 @@ erts_factory_message_create(ErtsHeapFactory* factory,
     int on_heap;
     erts_aint32_t state;
 
-    state = proc ? erts_atomic32_read_nob(&proc->state) : 0;
+    state = proc ? erts_atomic32_read_nob(&proc->state) : ERTS_PSFLG_OFF_HEAP_MSGQ;
 
     if (state & ERTS_PSFLG_OFF_HEAP_MSGQ) {
 	msgp = erts_alloc_message(sz, &hp);
@@ -1468,8 +1448,8 @@ void erts_factory_close(ErtsHeapFactory* factory)
 	    else
 		factory->message->data.heap_frag = factory->heap_frags;
 
-	    /* Fall through */
-	case FACTORY_HEAP_FRAGS:
+    /* Fall through */
+    case FACTORY_HEAP_FRAGS:
 	    bp = factory->heap_frags;
 	}
 
@@ -1610,6 +1590,9 @@ void erts_factory_undo(ErtsHeapFactory* factory)
 	    factory->message->hfrag.next = factory->heap_frags;
 	else
 	    factory->message->data.heap_frag = factory->heap_frags;
+        /* Set the message to NIL in order for this message not to be
+           treated as a distributed message by the cleanup_messages logic */
+        factory->message->m[0] = NIL;
 	erts_cleanup_messages(factory->message);
 	break;
     case FACTORY_TMP:
diff --git a/erts/emulator/beam/erl_message.h b/erts/emulator/beam/erl_message.h
index b2550814fd..5bd25737a7 100644
--- a/erts/emulator/beam/erl_message.h
+++ b/erts/emulator/beam/erl_message.h
@@ -22,10 +22,17 @@
 #define __ERL_MESSAGE_H__
 
 #include "sys.h"
+#include "erl_vm.h"
 #define ERTS_PROC_SIG_QUEUE_TYPE_ONLY
 #include "erl_proc_sig_queue.h"
 #undef ERTS_PROC_SIG_QUEUE_TYPE_ONLY
 
+#ifdef DEBUG
+#define ERTS_MSG_COPY_WORDS_PER_REDUCTION 4
+#else
+#define ERTS_MSG_COPY_WORDS_PER_REDUCTION 64
+#endif
+
 struct proc_bin;
 struct external_thing_;
 
@@ -111,6 +118,7 @@ erts_produce_heap(ErtsHeapFactory* factory, Uint need, Uint xtra)
     }
     res = factory->hp;
     factory->hp += need;
+    INIT_HEAP_MEM(res, need);
     return res;
 }
 
@@ -138,7 +146,7 @@ typedef struct erl_heap_fragment ErlHeapFragment;
 struct erl_heap_fragment {
     ErlHeapFragment* next;	/* Next heap fragment */
     ErlOffHeap off_heap;	/* Offset heap data. */
-    Uint alloc_size;		/* Size in (half)words of mem */
+    Uint alloc_size;		/* Size in words of mem */
     Uint used_size;		/* With terms to be moved to heap by GC */
     Eterm mem[1];		/* Data */
 };
@@ -167,7 +175,6 @@ struct erl_heap_fragment {
 #define ERL_MESSAGE_REF_FIELDS__			\
     ErtsMessage *next;	/* Next message */		\
     union {						\
-	ErtsDistExternal *dist_ext;			\
 	ErlHeapFragment *heap_frag;			\
 	void *attached;					\
     } data;						\
@@ -438,7 +445,8 @@ ErlHeapFragment* new_message_buffer(Uint);
 ErlHeapFragment* erts_resize_message_buffer(ErlHeapFragment *, Uint,
 					    Eterm *, Uint);
 void free_message_buffer(ErlHeapFragment *);
-void erts_queue_dist_message(Process*, ErtsProcLocks, ErtsDistExternal *, Eterm, Eterm);
+void erts_queue_dist_message(Process*, ErtsProcLocks, ErtsDistExternal *,
+                             ErlHeapFragment *, Eterm, Eterm);
 void erts_queue_message(Process*, ErtsProcLocks,ErtsMessage*, Eterm, Eterm);
 void erts_queue_proc_message(Process* from,Process* to, ErtsProcLocks,ErtsMessage*, Eterm);
 void erts_queue_proc_messages(Process* from, Process* to, ErtsProcLocks,
@@ -455,8 +463,6 @@ Sint erts_move_messages_off_heap(Process *c_p);
 Sint erts_complete_off_heap_message_queue_change(Process *c_p);
 Eterm erts_change_message_queue_management(Process *c_p, Eterm new_state);
 
-int erts_decode_dist_message(Process *, ErtsProcLocks, ErtsMessage *, int);
-
 void erts_cleanup_messages(ErtsMessage *mp);
 
 void *erts_alloc_message_ref(void);
@@ -585,22 +591,11 @@ ERTS_GLB_INLINE Uint erts_used_frag_sz(const ErlHeapFragment* bp)
 ERTS_GLB_INLINE Uint erts_msg_attached_data_size(ErtsMessage *msg)
 {
     ASSERT(msg->data.attached);
-    if (is_value(ERL_MESSAGE_TERM(msg))) {
-	ErlHeapFragment *bp;
-        bp = erts_message_to_heap_frag(msg);
-	return erts_used_frag_sz(bp);
-    }
-    else if (msg->data.dist_ext->heap_size < 0)
-	return erts_msg_attached_data_size_aux(msg);
-    else {
-	Uint sz = msg->data.dist_ext->heap_size;
-	if (is_not_nil(ERL_MESSAGE_TOKEN(msg))) {
-	    ErlHeapFragment *heap_frag;
-	    heap_frag = erts_dist_ext_trailer(msg->data.dist_ext);
-	    sz += heap_frag->used_size;
-	}
-	return sz;
-    }
+
+    if (ERTS_SIG_IS_INTERNAL_MSG(msg))
+	return erts_used_frag_sz(erts_message_to_heap_frag(msg));
+
+    return erts_msg_attached_data_size_aux(msg);
 }
 
 #endif
diff --git a/erts/emulator/beam/erl_monitor_link.c b/erts/emulator/beam/erl_monitor_link.c
index 48d9bd4ca5..43028be39d 100644
--- a/erts/emulator/beam/erl_monitor_link.c
+++ b/erts/emulator/beam/erl_monitor_link.c
@@ -191,7 +191,8 @@ ml_cmp_keys(Eterm key1, Eterm key2)
                 if (n1->sysname != n2->sysname)
                     return n1->sysname < n2->sysname ? -1 : 1;
                 ASSERT(n1->creation != n2->creation);
-                return n1->creation < n2->creation ? -1 : 1;
+                if (n1->creation != 0 && n2->creation != 0)
+                    return n1->creation < n2->creation ? -1 : 1;
             }
 
             ndw1 = external_thing_data_words(et1);
@@ -335,7 +336,7 @@ ml_rbt_delete(ErtsMonLnkNode **root, ErtsMonLnkNode *ml)
 
 static void
 ml_rbt_foreach(ErtsMonLnkNode *root,
-               void (*func)(ErtsMonLnkNode *, void *),
+               ErtsMonLnkNodeFunc func,
                void *arg)
 {
     mon_lnk_rbt_foreach(root, func, arg);
@@ -348,7 +349,7 @@ typedef struct {
 
 static int
 ml_rbt_foreach_yielding(ErtsMonLnkNode *root,
-                        void (*func)(ErtsMonLnkNode *, void *),
+                        ErtsMonLnkNodeFunc func,
                         void *arg,
                         void **vyspp,
                         Sint limit)
@@ -362,7 +363,7 @@ ml_rbt_foreach_yielding(ErtsMonLnkNode *root,
 	ysp = &ys;
     res = mon_lnk_rbt_foreach_yielding(ysp->root, func, arg,
                                        &ysp->rbt_ystate, limit);
-    if (res == 0) {
+    if (res > 0) {
 	if (ysp != &ys)
 	    erts_free(ERTS_ALC_T_ML_YIELD_STATE, ysp);
 	*vyspp = NULL;
@@ -383,22 +384,22 @@ ml_rbt_foreach_yielding(ErtsMonLnkNode *root,
 }
 
 typedef struct {
-    void (*func)(ErtsMonLnkNode *, void *);
+    ErtsMonLnkNodeFunc func;
     void *arg;
 } ErtsMonLnkForeachDeleteContext;
 
-static void
-rbt_wrap_foreach_delete(ErtsMonLnkNode *ml, void *vctxt)
+static int
+rbt_wrap_foreach_delete(ErtsMonLnkNode *ml, void *vctxt, Sint reds)
 {
     ErtsMonLnkForeachDeleteContext *ctxt = vctxt;
     ERTS_ML_ASSERT(ml->flags & ERTS_ML_FLG_IN_TABLE);
     ml->flags &= ~ERTS_ML_FLG_IN_TABLE;
-    ctxt->func(ml, ctxt->arg);
+    return ctxt->func(ml, ctxt->arg, reds);
 }
 
 static void
 ml_rbt_foreach_delete(ErtsMonLnkNode **root,
-                      void (*func)(ErtsMonLnkNode *, void *),
+                      ErtsMonLnkNodeFunc func,
                       void *arg)
 {
     ErtsMonLnkForeachDeleteContext ctxt;
@@ -411,7 +412,7 @@ ml_rbt_foreach_delete(ErtsMonLnkNode **root,
 
 static int
 ml_rbt_foreach_delete_yielding(ErtsMonLnkNode **root,
-                               void (*func)(ErtsMonLnkNode *, void *),
+                               ErtsMonLnkNodeFunc func,
                                void *arg,
                                void **vyspp,
                                Sint limit)
@@ -433,7 +434,7 @@ ml_rbt_foreach_delete_yielding(ErtsMonLnkNode **root,
                                                (void *) &ctxt,
                                                &ysp->rbt_ystate,
                                                limit);
-    if (res == 0) {
+    if (res > 0) {
 	if (ysp != &ys)
 	    erts_free(ERTS_ALC_T_ML_YIELD_STATE, ysp);
 	*vyspp = NULL;
@@ -459,12 +460,11 @@ ml_rbt_foreach_delete_yielding(ErtsMonLnkNode **root,
 
 static int
 ml_dl_list_foreach_yielding(ErtsMonLnkNode *list,
-                            void (*func)(ErtsMonLnkNode *, void *),
+                            ErtsMonLnkNodeFunc func,
                             void *arg,
                             void **vyspp,
-                            Sint limit)
+                            Sint reds)
 {
-    Sint cnt = 0;
     ErtsMonLnkNode *ml = (ErtsMonLnkNode *) *vyspp;
 
     ERTS_ML_ASSERT(!ml || list);
@@ -475,28 +475,26 @@ ml_dl_list_foreach_yielding(ErtsMonLnkNode *list,
     if (ml) {
         do {
             ERTS_ML_ASSERT(ml->flags & ERTS_ML_FLG_IN_TABLE);
-            func(ml, arg);
+            reds -= func(ml, arg, reds);
             ml = ml->node.list.next;
-            cnt++;
-        } while (ml != list && cnt < limit);
+        } while (ml != list && reds > 0);
         if (ml != list) {
             *vyspp = (void *) ml;
-            return 1; /* yield */
+            return 0; /* yield */
         }
     }
 
     *vyspp = NULL;
-    return 0; /* done */
+    return reds <= 0 ? 1 : reds; /* done */
 }
 
 static int
 ml_dl_list_foreach_delete_yielding(ErtsMonLnkNode **list,
-                                   void (*func)(ErtsMonLnkNode *, void *),
+                                   ErtsMonLnkNodeFunc func,
                                    void *arg,
                                    void **vyspp,
-                                   Sint limit)
+                                   Sint reds)
 {
-    Sint cnt = 0;
     ErtsMonLnkNode *first = *list;
     ErtsMonLnkNode *ml = (ErtsMonLnkNode *) *vyspp;
 
@@ -510,19 +508,18 @@ ml_dl_list_foreach_delete_yielding(ErtsMonLnkNode **list,
             ErtsMonLnkNode *next = ml->node.list.next;
             ERTS_ML_ASSERT(ml->flags & ERTS_ML_FLG_IN_TABLE);
             ml->flags &= ~ERTS_ML_FLG_IN_TABLE;
-            func(ml, arg);
+            reds -= func(ml, arg, reds);
             ml = next;
-            cnt++;
-        } while (ml != first && cnt < limit);
+        } while (ml != first && reds > 0);
         if (ml != first) {
             *vyspp = (void *) ml;
-            return 1; /* yield */
+            return 0; /* yield */
         }
     }
 
     *vyspp = NULL;
     *list = NULL;
-    return 0; /* done */
+    return reds <= 0 ? 1 : reds; /* done */
 }
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
@@ -666,91 +663,122 @@ erts_monitor_tree_delete(ErtsMonitor **root, ErtsMonitor *mon)
 
 void
 erts_monitor_tree_foreach(ErtsMonitor *root,
-                          void (*func)(ErtsMonitor *, void *),
+                          ErtsMonitorFunc func,
                           void *arg)
 {
     ml_rbt_foreach((ErtsMonLnkNode *) root,
-                   (void (*)(ErtsMonLnkNode*, void*)) func,
+                   (ErtsMonLnkNodeFunc) func,
                    arg);
 }
 
+void
+erts_debug_monitor_tree_destroying_foreach(ErtsMonitor *root,
+                                           ErtsMonitorFunc func,
+                                           void *arg,
+                                           void *vysp)
+{
+    void *tmp_vysp = erts_alloc(ERTS_ALC_T_ML_YIELD_STATE,
+                                sizeof(ErtsMonLnkYieldState));
+    Sint reds;
+    sys_memcpy(tmp_vysp, tmp_vysp, sizeof(ErtsMonLnkYieldState));
+    do {
+        reds = ml_rbt_foreach_yielding((ErtsMonLnkNode *) root,
+                                       (ErtsMonLnkNodeFunc) func,
+                                       arg, &tmp_vysp, (Sint) INT_MAX);
+    } while (reds <= 0);
+    ERTS_ML_ASSERT(!tmp_vysp);
+}
+
 int
 erts_monitor_tree_foreach_yielding(ErtsMonitor *root,
-                                   void (*func)(ErtsMonitor *, void *),
+                                   ErtsMonitorFunc func,
                                    void *arg,
                                    void **vyspp,
                                    Sint limit)
 {
     return ml_rbt_foreach_yielding((ErtsMonLnkNode *) root,
-                                   (void (*)(ErtsMonLnkNode*, void*)) func,
+                                   (int (*)(ErtsMonLnkNode*, void*, Sint)) func,
                                    arg, vyspp, limit);
 }
 
 void
 erts_monitor_tree_foreach_delete(ErtsMonitor **root,
-                                 void (*func)(ErtsMonitor *, void *),
+                                 ErtsMonitorFunc func,
                                  void *arg)
 {
     ml_rbt_foreach_delete((ErtsMonLnkNode **) root,
-                          (void (*)(ErtsMonLnkNode*, void*)) func,
+                          (int (*)(ErtsMonLnkNode*, void*, Sint)) func,
                           arg);
 }
 
 int
 erts_monitor_tree_foreach_delete_yielding(ErtsMonitor **root,
-                                          void (*func)(ErtsMonitor *, void *),
+                                          ErtsMonitorFunc func,
                                           void *arg,
                                           void **vyspp,
                                           Sint limit)
 {
     return ml_rbt_foreach_delete_yielding((ErtsMonLnkNode **) root,
-                                          (void (*)(ErtsMonLnkNode*, void*)) func,
+                                          (int (*)(ErtsMonLnkNode*, void*, Sint)) func,
                                           arg, vyspp, limit);
 }
 
 void
 erts_monitor_list_foreach(ErtsMonitor *list,
-                          void (*func)(ErtsMonitor *, void *),
+                          ErtsMonitorFunc func,
                           void *arg)
 {
     void *ystate = NULL;
-    while (ml_dl_list_foreach_yielding((ErtsMonLnkNode *) list,
-                                       (void (*)(ErtsMonLnkNode *, void *)) func,
-                                       arg, &ystate, (Sint) INT_MAX));
+    while (!ml_dl_list_foreach_yielding((ErtsMonLnkNode *) list,
+                                        (int (*)(ErtsMonLnkNode *, void *, Sint)) func,
+                                        arg, &ystate, (Sint) INT_MAX));
+}
+
+void
+erts_debug_monitor_list_destroying_foreach(ErtsMonitor *list,
+                                           ErtsMonitorFunc func,
+                                           void *arg,
+                                           void *vysp)
+{
+    void *tmp_vysp = vysp;
+    while (!ml_dl_list_foreach_yielding((ErtsMonLnkNode *) list,
+                                        (int (*)(ErtsMonLnkNode *, void *, Sint)) func,
+                                        arg, &tmp_vysp, (Sint) INT_MAX));
+    ERTS_ML_ASSERT(!tmp_vysp);
 }
 
 int
 erts_monitor_list_foreach_yielding(ErtsMonitor *list,
-                                   void (*func)(ErtsMonitor *, void *),
+                                   ErtsMonitorFunc func,
                                    void *arg,
                                    void **vyspp,
                                    Sint limit)
 {
     return ml_dl_list_foreach_yielding((ErtsMonLnkNode *) list,
-                                       (void (*)(ErtsMonLnkNode *, void *)) func,
+                                       (int (*)(ErtsMonLnkNode *, void *, Sint)) func,
                                        arg, vyspp, limit);
 }
 
 void
 erts_monitor_list_foreach_delete(ErtsMonitor **list,
-                                 void (*func)(ErtsMonitor *, void *),
+                                 ErtsMonitorFunc func,
                                  void *arg)
 {
     void *ystate = NULL;
-    while (ml_dl_list_foreach_delete_yielding((ErtsMonLnkNode **) list,
-                                              (void (*)(ErtsMonLnkNode*, void*)) func,
-                                              arg, &ystate, (Sint) INT_MAX));
+    while (!ml_dl_list_foreach_delete_yielding((ErtsMonLnkNode **) list,
+                                               (int (*)(ErtsMonLnkNode*, void*, Sint)) func,
+                                               arg, &ystate, (Sint) INT_MAX));
 }
 
 int
 erts_monitor_list_foreach_delete_yielding(ErtsMonitor **list,
-                                          void (*func)(ErtsMonitor *, void *),
+                                          ErtsMonitorFunc func,
                                           void *arg,
                                           void **vyspp,
                                           Sint limit)
 {
     return ml_dl_list_foreach_delete_yielding((ErtsMonLnkNode **) list,
-                                              (void (*)(ErtsMonLnkNode*, void*)) func,
+                                              (int (*)(ErtsMonLnkNode*, void*, Sint)) func,
                                               arg, vyspp, limit);
 }
 
@@ -1074,92 +1102,110 @@ erts_link_tree_delete(ErtsLink **root, ErtsLink *lnk)
 
 void
 erts_link_tree_foreach(ErtsLink *root,
-                       void (*func)(ErtsLink *, void *),
+                       ErtsLinkFunc func,
                        void *arg)
 {
     ml_rbt_foreach((ErtsMonLnkNode *) root,
-                   (void (*)(ErtsMonLnkNode*, void*)) func,
+                   (ErtsMonLnkNodeFunc) func,
                    arg);
 
 }
 
+void
+erts_debug_link_tree_destroying_foreach(ErtsLink *root,
+                                        ErtsLinkFunc func,
+                                        void *arg,
+                                        void *vysp)
+{
+    void *tmp_vysp = erts_alloc(ERTS_ALC_T_ML_YIELD_STATE,
+                                sizeof(ErtsMonLnkYieldState));
+    Sint reds;
+    sys_memcpy(tmp_vysp, vysp, sizeof(ErtsMonLnkYieldState));
+    do {
+        reds = ml_rbt_foreach_yielding((ErtsMonLnkNode *) root,
+                                       (ErtsMonLnkNodeFunc) func,
+                                       arg, &tmp_vysp, (Sint) INT_MAX);
+    } while (reds <= 0);
+    ERTS_ML_ASSERT(!tmp_vysp);
+}
+
 int
 erts_link_tree_foreach_yielding(ErtsLink *root,
-                                void (*func)(ErtsLink *, void *),
+                                ErtsLinkFunc func,
                                 void *arg,
                                 void **vyspp,
                                 Sint limit)
 {
     return ml_rbt_foreach_yielding((ErtsMonLnkNode *) root,
-                                   (void (*)(ErtsMonLnkNode*, void*)) func,
+                                   (ErtsMonLnkNodeFunc) func,
                                    arg, vyspp, limit);
 }
 
 void
 erts_link_tree_foreach_delete(ErtsLink **root,
-                              void (*func)(ErtsLink *, void *),
+                              ErtsLinkFunc func,
                               void *arg)
 {
     ml_rbt_foreach_delete((ErtsMonLnkNode **) root,
-                          (void (*)(ErtsMonLnkNode*, void*)) func,
+                          (ErtsMonLnkNodeFunc) func,
                           arg);
 }
 
 int
 erts_link_tree_foreach_delete_yielding(ErtsLink **root,
-                                       void (*func)(ErtsLink *, void *),
+                                       ErtsLinkFunc func,
                                        void *arg,
                                        void **vyspp,
                                        Sint limit)
 {
     return ml_rbt_foreach_delete_yielding((ErtsMonLnkNode **) root,
-                                          (void (*)(ErtsMonLnkNode*, void*)) func,
+                                          (ErtsMonLnkNodeFunc) func,
                                           arg, vyspp, limit);
 }
 
 void
 erts_link_list_foreach(ErtsLink *list,
-                       void (*func)(ErtsLink *, void *),
+                       ErtsLinkFunc func,
                        void *arg)
 {
     void *ystate = NULL;
-    while (ml_dl_list_foreach_yielding((ErtsMonLnkNode *) list,
-                                       (void (*)(ErtsMonLnkNode *, void *)) func,
-                                       arg, &ystate, (Sint) INT_MAX));
+    while (!ml_dl_list_foreach_yielding((ErtsMonLnkNode *) list,
+                                        (ErtsMonLnkNodeFunc) func,
+                                        arg, &ystate, (Sint) INT_MAX));
 }
 
 int
 erts_link_list_foreach_yielding(ErtsLink *list,
-                                void (*func)(ErtsLink *, void *),
+                                ErtsLinkFunc func,
                                 void *arg,
                                 void **vyspp,
                                 Sint limit)
 {
     return ml_dl_list_foreach_yielding((ErtsMonLnkNode *) list,
-                                       (void (*)(ErtsMonLnkNode *, void *)) func,
+                                       (ErtsMonLnkNodeFunc) func,
                                        arg, vyspp, limit);
 }
 
 void
 erts_link_list_foreach_delete(ErtsLink **list,
-                               void (*func)(ErtsLink *, void *),
+                               ErtsLinkFunc func,
                                void *arg)
 {
     void *ystate = NULL;
-    while (ml_dl_list_foreach_delete_yielding((ErtsMonLnkNode **) list,
-                                              (void (*)(ErtsMonLnkNode*, void*)) func,
-                                              arg, &ystate, (Sint) INT_MAX));
+    while (!ml_dl_list_foreach_delete_yielding((ErtsMonLnkNode **) list,
+                                               (ErtsMonLnkNodeFunc) func,
+                                               arg, &ystate, (Sint) INT_MAX));
 }
 
 int
 erts_link_list_foreach_delete_yielding(ErtsLink **list,
-                                       void (*func)(ErtsLink *, void *),
+                                       int (*func)(ErtsLink *, void *, Sint),
                                        void *arg,
                                        void **vyspp,
                                        Sint limit)
 {
     return ml_dl_list_foreach_delete_yielding((ErtsMonLnkNode **) list,
-                                              (void (*)(ErtsMonLnkNode*, void*)) func,
+                                              (ErtsMonLnkNodeFunc) func,
                                               arg, vyspp, limit);
 }
 
diff --git a/erts/emulator/beam/erl_monitor_link.h b/erts/emulator/beam/erl_monitor_link.h
index ed7bf7d54a..86be400c09 100644
--- a/erts/emulator/beam/erl_monitor_link.h
+++ b/erts/emulator/beam/erl_monitor_link.h
@@ -439,6 +439,7 @@
     (ERTS_ML_FLG_EXTENDED|ERTS_ML_FLG_NAME)
 
 typedef struct ErtsMonLnkNode__ ErtsMonLnkNode;
+typedef int (*ErtsMonLnkNodeFunc)(ErtsMonLnkNode *, void *, Sint);
 
 typedef struct {
     UWord parent; /* Parent ptr and flags... */
@@ -622,6 +623,7 @@ erts_ml_dl_list_last__(ErtsMonLnkNode *list)
 
 
 typedef struct ErtsMonLnkNode__ ErtsMonitor;
+typedef int (*ErtsMonitorFunc)(ErtsMonitor *, void *, Sint);
 
 typedef struct {
     ErtsMonitor origin;
@@ -653,6 +655,7 @@ struct ErtsMonitorDataExtended__ {
 
 typedef struct ErtsMonitorSuspend__ ErtsMonitorSuspend;
 
+
 struct ErtsMonitorSuspend__ {
     ErtsMonitorData md; /* origin = suspender; target = suspendee */
     ErtsMonitorSuspend *next;
@@ -685,7 +688,7 @@ ErtsMonitor *erts_monitor_tree_lookup(ErtsMonitor *root, Eterm key);
  *
  * @brief Lookup or insert a monitor in a monitor tree
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'mon' monitor is not part of any tree or list
  * If the above is not true, bad things will happen.
  *
@@ -711,7 +714,7 @@ ErtsMonitor *erts_monotor_tree_lookup_insert(ErtsMonitor **root,
  * If it is not found, creates a monitor and returns a pointer to the
  * origin monitor.
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - no target monitors with the key 'target' exists in the tree.
  * If the above is not true, bad things will happen.
  *
@@ -738,7 +741,7 @@ ErtsMonitor *erts_monitor_tree_lookup_create(ErtsMonitor **root, int *created,
  *
  * @brief Insert a monitor in a monitor tree
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - no monitors with the same key that 'mon' exist in the tree
  * - 'mon' is not part of any list of tree
  * If the above are not true, bad things will happen.
@@ -754,7 +757,7 @@ void erts_monitor_tree_insert(ErtsMonitor **root, ErtsMonitor *mon);
  *
  * @brief Replace a monitor in a monitor tree
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'old' monitor and 'new' monitor have exactly the same key
  * - 'old' monitor is part of the tree
  * - 'new' monitor is not part of any tree or list
@@ -774,7 +777,7 @@ void erts_monitor_tree_replace(ErtsMonitor **root, ErtsMonitor *old,
  *
  * @brief Delete a monitor from a monitor tree
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'mon' monitor is part of the tree
  * If the above is not true, bad things will happen.
  *
@@ -789,7 +792,7 @@ void erts_monitor_tree_delete(ErtsMonitor **root, ErtsMonitor *mon);
  *
  * @brief Call a function for each monitor in a monitor tree
  *
- * The funcion 'func' will be called with a pointer to a monitor
+ * The function 'func' will be called with a pointer to a monitor
  * as first argument and 'arg' as second argument for each monitor
  * in the tree referred to by 'root'.
  *
@@ -802,7 +805,7 @@ void erts_monitor_tree_delete(ErtsMonitor **root, ErtsMonitor *mon);
  *
  */
 void erts_monitor_tree_foreach(ErtsMonitor *root,
-                               void (*func)(ErtsMonitor *, void *),
+                               ErtsMonitorFunc func,
                                void *arg);
 
 /**
@@ -810,9 +813,10 @@ void erts_monitor_tree_foreach(ErtsMonitor *root,
  * @brief Call a function for each monitor in a monitor tree. Yield
  *        if lots of monitors exist.
  *
- * The funcion 'func' will be called with a pointer to a monitor
+ * The function 'func' will be called with a pointer to a monitor
  * as first argument and 'arg' as second argument for each monitor
- * in the tree referred to by 'root'.
+ * in the tree referred to by 'root'. It should return the number of
+ * reductions the operator took to perform.
  *
  * It is assumed that:
  * - *yspp equals NULL on first call
@@ -835,27 +839,28 @@ void erts_monitor_tree_foreach(ErtsMonitor *root,
  *                              *yspp should be NULL. When done *yspp
  *                              will be NULL.
  *
- * @param[in]     limit         Maximum amount of monitors to process
- *                              before yielding.
+ * @param[in]     reds          Reductions available to execute before yielding.
  *
- * @returns                     A non-zero value when all monitors has been
- *                              processed, and zero when more work is needed.
+ * @returns                     The unconsumed reductions when all monitors
+ *                              have been processed, and zero when more work
+ *                              is needed.
  *
  */
 int erts_monitor_tree_foreach_yielding(ErtsMonitor *root,
-                                       void (*func)(ErtsMonitor *, void *),
+                                       ErtsMonitorFunc func,
                                        void *arg,
                                        void **vyspp,
-                                       Sint limit);
+                                       Sint reds);
 
 /**
  *
  * @brief Delete all monitors from a monitor tree and call a function for
  *        each monitor
  *
- * The funcion 'func' will be called with a pointer to a monitor
+ * The function 'func' will be called with a pointer to a monitor
  * as first argument and 'arg' as second argument for each monitor
- * in the tree referred to by 'root'.
+ * in the tree referred to by 'root'. It should return the number of
+ * reductions the operator took to perform.
  *
  * @param[in,out] root          Pointer to pointer to root of monitor tree
  *
@@ -866,7 +871,7 @@ int erts_monitor_tree_foreach_yielding(ErtsMonitor *root,
  *
  */
 void erts_monitor_tree_foreach_delete(ErtsMonitor **root,
-                                      void (*func)(ErtsMonitor *, void *),
+                                      ErtsMonitorFunc func,
                                       void *arg);
 
 /**
@@ -874,9 +879,10 @@ void erts_monitor_tree_foreach_delete(ErtsMonitor **root,
  * @brief Delete all monitors from a monitor tree and call a function for
  *        each monitor
  *
- * The funcion 'func' will be called with a pointer to a monitor
+ * The function 'func' will be called with a pointer to a monitor
  * as first argument and 'arg' as second argument for each monitor
- * in the tree referred to by 'root'.
+ * in the tree referred to by 'root'. It should return the number of
+ * reductions the operator took to perform.
  *
  * It is assumed that:
  * - *yspp equals NULL on first call
@@ -899,18 +905,18 @@ void erts_monitor_tree_foreach_delete(ErtsMonitor **root,
  *                              *yspp should be NULL. When done *yspp
  *                              will be NULL.
  *
- * @param[in]     limit         Maximum amount of monitors to process
- *                              before yielding.
+ * @param[in]     reds          Reductions available to execute before yielding.
  *
- * @returns                     A non-zero value when all monitors has been
- *                              processed, and zero when more work is needed.
+ * @returns                     The unconsumed reductions when all monitors
+ *                              have been processed, and zero when more work
+ *                              is needed.
  *
  */
 int erts_monitor_tree_foreach_delete_yielding(ErtsMonitor **root,
-                                              void (*func)(ErtsMonitor *, void *),
+                                              ErtsMonitorFunc func,
                                               void *arg,
                                               void **vyspp,
-                                              Sint limit);
+                                              Sint reds);
 
 /*
  * --- Monitor list operations --
@@ -920,7 +926,7 @@ int erts_monitor_tree_foreach_delete_yielding(ErtsMonitor **root,
  *
  * @brief Insert a monitor in a monitor list
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'mon' monitor is not part of any list or tree
  * If the above is not true, bad things will happen.
  *
@@ -935,7 +941,7 @@ ERTS_GLB_INLINE void erts_monitor_list_insert(ErtsMonitor **list, ErtsMonitor *m
  *
  * @brief Delete a monitor from a monitor list
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'mon' monitor is part of the list
  * If the above is not true, bad things will happen.
  *
@@ -980,7 +986,7 @@ ERTS_GLB_INLINE ErtsMonitor *erts_monitor_list_last(ErtsMonitor *list);
  *
  * @brief Call a function for each monitor in a monitor list
  *
- * The funcion 'func' will be called with a pointer to a monitor
+ * The function 'func' will be called with a pointer to a monitor
  * as first argument and 'arg' as second argument for each monitor
  * in the tree referred to by 'list'.
  *
@@ -993,7 +999,7 @@ ERTS_GLB_INLINE ErtsMonitor *erts_monitor_list_last(ErtsMonitor *list);
  *
  */
 void erts_monitor_list_foreach(ErtsMonitor *list,
-                               void (*func)(ErtsMonitor *, void *),
+                               ErtsMonitorFunc func,
                                void *arg);
 
 /**
@@ -1001,9 +1007,10 @@ void erts_monitor_list_foreach(ErtsMonitor *list,
  * @brief Call a function for each monitor in a monitor list. Yield
  *        if lots of monitors exist.
  *
- * The funcion 'func' will be called with a pointer to a monitor
+ * The function 'func' will be called with a pointer to a monitor
  * as first argument and 'arg' as second argument for each monitor
- * in the tree referred to by 'root'.
+ * in the tree referred to by 'root'. It should return the number of
+ * reductions the operator took to perform.
  *
  * It is assumed that:
  * - *yspp equals NULL on first call
@@ -1026,25 +1033,25 @@ void erts_monitor_list_foreach(ErtsMonitor *list,
  *                              *yspp should be NULL. When done *yspp
  *                              will be NULL.
  *
- * @param[in]     limit         Maximum amount of monitors to process
- *                              before yielding.
+ * @param[in]     reds          Reductions available to execute before yielding.
  *
- * @returns                     A non-zero value when all monitors has been
- *                              processed, and zero when more work is needed.
+ * @returns                     The unconsumed reductions when all monitors
+ *                              have been processed, and zero when more work
+ *                              is needed.
  *
  */
 int erts_monitor_list_foreach_yielding(ErtsMonitor *list,
-                                       void (*func)(ErtsMonitor *, void *),
+                                       ErtsMonitorFunc func,
                                        void *arg,
                                        void **vyspp,
-                                       Sint limit);
+                                       Sint reds);
 
 /**
  *
  * @brief Delete all monitors from a monitor list and call a function for
  *        each monitor
  *
- * The funcion 'func' will be called with a pointer to a monitor
+ * The function 'func' will be called with a pointer to a monitor
  * as first argument and 'arg' as second argument for each monitor
  * in the tree referred to by 'root'.
  *
@@ -1057,7 +1064,7 @@ int erts_monitor_list_foreach_yielding(ErtsMonitor *list,
  *
  */
 void erts_monitor_list_foreach_delete(ErtsMonitor **list,
-                                      void (*func)(ErtsMonitor *, void *),
+                                      ErtsMonitorFunc func,
                                       void *arg);
 
 /**
@@ -1065,9 +1072,10 @@ void erts_monitor_list_foreach_delete(ErtsMonitor **list,
  * @brief Delete all monitors from a monitor list and call a function for
  *        each monitor
  *
- * The funcion 'func' will be called with a pointer to a monitor
+ * The function 'func' will be called with a pointer to a monitor
  * as first argument and 'arg' as second argument for each monitor
- * in the tree referred to by 'root'.
+ * in the tree referred to by 'root'. It should return the number of
+ * reductions the operator took to perform.
  *
  * It is assumed that:
  * - *yspp equals NULL on first call
@@ -1090,18 +1098,18 @@ void erts_monitor_list_foreach_delete(ErtsMonitor **list,
  *                              *yspp should be NULL. When done *yspp
  *                              will be NULL.
  *
- * @param[in]     limit         Maximum amount of monitors to process
- *                              before yielding.
+ * @param[in]     reds          Reductions available to execute before yielding.
  *
- * @returns                     A non-zero value when all monitors has been
- *                              processed, and zero when more work is needed.
+ * @returns                     The unconsumed reductions when all monitors
+ *                              have been processed, and zero when more work
+ *                              is needed.
  *
  */
 int erts_monitor_list_foreach_delete_yielding(ErtsMonitor **list,
-                                              void (*func)(ErtsMonitor *, void *),
+                                              ErtsMonitorFunc func,
                                               void *arg,
                                               void **vyspp,
-                                              Sint limit);
+                                              Sint reds);
 
 /*
  * --- Misc monitor operations ---
@@ -1113,7 +1121,7 @@ int erts_monitor_list_foreach_delete_yielding(ErtsMonitor **list,
  *
  * Can create all types of monitors
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'ref' is an internal ordinary reference if type is ERTS_MON_TYPE_PROC,
  *   ERTS_MON_TYPE_PORT, ERTS_MON_TYPE_TIME_OFFSET, or ERTS_MON_TYPE_RESOURCE
  * - 'ref' is NIL if type is ERTS_MON_TYPE_NODE, ERTS_MON_TYPE_NODES, or
@@ -1199,7 +1207,7 @@ ERTS_GLB_INLINE int erts_monitor_is_in_table(ErtsMonitor *mon);
  * When both the origin and the target part of the monitor have
  * been released the monitor structure will be deallocated.
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'mon' monitor is not part of any list or tree
  * - 'mon' is not referred to by any other structures
  * If the above are not true, bad things will happen.
@@ -1216,7 +1224,7 @@ ERTS_GLB_INLINE void erts_monitor_release(ErtsMonitor *mon);
  * Release both the origin and target parts of the monitor
  * simultaneously and deallocate the structure.
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - Neither the origin part nor the target part of the monitor
  *   are not part of any list or tree
  * - Neither the origin part nor the target part of the monitor
@@ -1232,7 +1240,7 @@ ERTS_GLB_INLINE void erts_monitor_release_both(ErtsMonitorData *mdp);
  *
  * @brief Insert monitor in dist monitor tree or list
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'mon' monitor is not part of any list or tree
  * If the above is not true, bad things will happen.
  *
@@ -1253,7 +1261,7 @@ ERTS_GLB_INLINE int erts_monitor_dist_insert(ErtsMonitor *mon, ErtsMonLnkDist *d
  *
  * @brief Delete monitor from dist monitor tree or list
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'mon' monitor earler has been inserted into 'dist'
  * If the above is not true, bad things will happen.
  *
@@ -1291,7 +1299,7 @@ erts_monitor_set_dead_dist(ErtsMonitor *mon, Eterm nodename);
  * whole size of the monitor data structure is returned; otherwise,
  * half of the size is returned.
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'mon' has not been released
  * If the above is not true, bad things will happen.
  *
@@ -1501,12 +1509,25 @@ ERTS_GLB_INLINE ErtsMonitorSuspend *erts_monitor_suspend(ErtsMonitor *mon)
 
 #endif
 
+void
+erts_debug_monitor_tree_destroying_foreach(ErtsMonitor *root,
+                                           ErtsMonitorFunc func,
+                                           void *arg,
+                                           void *vysp);
+void
+erts_debug_monitor_list_destroying_foreach(ErtsMonitor *list,
+                                           ErtsMonitorFunc func,
+                                           void *arg,
+                                           void *vysp);
+
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
  * Link Operations                                                           *
 \*                                                                           */
 
 typedef struct ErtsMonLnkNode__ ErtsLink;
 
+typedef int (*ErtsLinkFunc)(ErtsLink *, void *, Sint);
+
 typedef struct {
     ErtsLink a;
     ErtsLink b;
@@ -1544,7 +1565,7 @@ ErtsLink *erts_link_tree_lookup(ErtsLink *root, Eterm item);
  *
  * @brief Lookup or insert a link in a link tree
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'lnk' link is not part of any tree or list
  * If the above is not true, bad things will happen.
  *
@@ -1590,7 +1611,7 @@ ErtsLink *erts_link_tree_lookup_create(ErtsLink **root, int *created,
  *
  * @brief Insert a link in a link tree
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - no links with the same key that 'lnk' exist in the tree
  * - 'lnk' is not part of any list of tree
  * If the above are not true, bad things will happen.
@@ -1606,7 +1627,7 @@ void erts_link_tree_insert(ErtsLink **root, ErtsLink *lnk);
  *
  * @brief Replace a link in a link tree
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'old' link and 'new' link have exactly the same key
  * - 'old' link is part of the tree
  * - 'new' link is not part of any tree or list
@@ -1630,7 +1651,7 @@ void erts_link_tree_replace(ErtsLink **root, ErtsLink *old, ErtsLink *new);
  * the tree and 'lnk' has a lower address than the link in the
  * tree, the existing link in the tree is replaced by 'lnk'.
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'lnk' link is not part of any tree or list
  * If the above are not true, bad things will happen.
  *
@@ -1649,7 +1670,7 @@ ERTS_GLB_INLINE ErtsLink *erts_link_tree_insert_addr_replace(ErtsLink **root,
  *
  * @brief Delete a link from a link tree
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'lnk' link is part of the tree
  * If the above is not true, bad things will happen.
  *
@@ -1668,7 +1689,7 @@ void erts_link_tree_delete(ErtsLink **root, ErtsLink *lnk);
  * If link 'lnk' is not in the tree, another link with the same
  * key as 'lnk' is deleted from the tree if such a link exist.
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - if 'lnk' link is part of a tree or list, it is part of this tree
  * If the above is not true, bad things will happen.
  *
@@ -1687,7 +1708,7 @@ ERTS_GLB_INLINE ErtsLink *erts_link_tree_key_delete(ErtsLink **root, ErtsLink *l
  *
  * @brief Call a function for each link in a link tree
  *
- * The funcion 'func' will be called with a pointer to a link
+ * The function 'func' will be called with a pointer to a link
  * as first argument and 'arg' as second argument for each link
  * in the tree referred to by 'root'.
  *
@@ -1700,7 +1721,7 @@ ERTS_GLB_INLINE ErtsLink *erts_link_tree_key_delete(ErtsLink **root, ErtsLink *l
  *
  */
 void erts_link_tree_foreach(ErtsLink *root,
-                            void (*func)(ErtsLink *, void *),
+                            ErtsLinkFunc,
                             void *arg);
 
 /**
@@ -1708,9 +1729,10 @@ void erts_link_tree_foreach(ErtsLink *root,
  * @brief Call a function for each link in a link tree. Yield if lots
  *        of links exist.
  *
- * The funcion 'func' will be called with a pointer to a link
+ * The function 'func' will be called with a pointer to a link
  * as first argument and 'arg' as second argument for each link
- * in the tree referred to by 'root'.
+ * in the tree referred to by 'root'. It should return the number of
+ * reductions the operator took to perform.
  *
  * It is assumed that:
  * - *yspp equals NULL on first call
@@ -1733,25 +1755,25 @@ void erts_link_tree_foreach(ErtsLink *root,
  *                              *yspp should be NULL. When done *yspp
  *                              will be NULL.
  *
- * @param[in]     limit         Maximum amount of links to process
- *                              before yielding.
+ * @param[in]     reds          Reductions available to execute before yielding.
  *
- * @returns                     A non-zero value when all links has been
- *                              processed, and zero when more work is needed.
+ * @returns                     The unconsumed reductions when all links
+ *                              have been processed, and zero when more work
+ *                              is needed.
  *
  */
 int erts_link_tree_foreach_yielding(ErtsLink *root,
-                                    void (*func)(ErtsLink *, void *),
+                                    ErtsLinkFunc func,
                                     void *arg,
                                     void **vyspp,
-                                    Sint limit);
+                                    Sint reds);
 
 /**
  *
  * @brief Delete all links from a link tree and call a function for
  *        each link
  *
- * The funcion 'func' will be called with a pointer to a link
+ * The function 'func' will be called with a pointer to a link
  * as first argument and 'arg' as second argument for each link
  * in the tree referred to by 'root'.
  *
@@ -1764,7 +1786,7 @@ int erts_link_tree_foreach_yielding(ErtsLink *root,
  *
  */
 void erts_link_tree_foreach_delete(ErtsLink **root,
-                                   void (*func)(ErtsLink *, void *),
+                                   ErtsLinkFunc func,
                                    void *arg);
 
 /**
@@ -1772,9 +1794,10 @@ void erts_link_tree_foreach_delete(ErtsLink **root,
  * @brief Delete all links from a link tree and call a function for
  *        each link
  *
- * The funcion 'func' will be called with a pointer to a link
+ * The function 'func' will be called with a pointer to a link
  * as first argument and 'arg' as second argument for each link
- * in the tree referred to by 'root'.
+ * in the tree referred to by 'root'. It should return the number of
+ * reductions the operator took to perform.
  *
  * It is assumed that:
  * - *yspp equals NULL on first call
@@ -1797,18 +1820,18 @@ void erts_link_tree_foreach_delete(ErtsLink **root,
  *                              *yspp should be NULL. When done *yspp
  *                              will be NULL.
  *
- * @param[in]     limit         Maximum amount of links to process
- *                              before yielding.
+ * @param[in]     reds          Reductions available to execute before yielding.
  *
- * @returns                     A non-zero value when all links has been
- *                              processed, and zero when more work is needed.
+ * @returns                     The unconsumed reductions when all links
+ *                              have been processed, and zero when more work
+ *                              is needed.
  *
  */
 int erts_link_tree_foreach_delete_yielding(ErtsLink **root,
-                                           void (*func)(ErtsLink *, void *),
+                                           ErtsLinkFunc func,
                                            void *arg,
                                            void **vyspp,
-                                           Sint limit);
+                                           Sint reds);
 
 /* 
  * --- Link list operations ---
@@ -1818,7 +1841,7 @@ int erts_link_tree_foreach_delete_yielding(ErtsLink **root,
  *
  * @brief Insert a link in a link list
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'lnk' link is not part of any list or tree
  * If the above is not true, bad things will happen.
  *
@@ -1833,7 +1856,7 @@ ERTS_GLB_INLINE void erts_link_list_insert(ErtsLink **list, ErtsLink *lnk);
  *
  * @brief Delete a link from a link list
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'lnk' link is part of the list
  * If the above is not true, bad things will happen.
  *
@@ -1878,7 +1901,7 @@ ERTS_GLB_INLINE ErtsLink *erts_link_list_last(ErtsLink *list);
  *
  * @brief Call a function for each link in a link list
  *
- * The funcion 'func' will be called with a pointer to a link
+ * The function 'func' will be called with a pointer to a link
  * as first argument and 'arg' as second argument for each link
  * in the tree referred to by 'list'.
  *
@@ -1891,7 +1914,7 @@ ERTS_GLB_INLINE ErtsLink *erts_link_list_last(ErtsLink *list);
  *
  */
 void erts_link_list_foreach(ErtsLink *list,
-                            void (*func)(ErtsLink *, void *),
+                            ErtsLinkFunc func,
                             void *arg);
 
 /**
@@ -1899,9 +1922,10 @@ void erts_link_list_foreach(ErtsLink *list,
  * @brief Call a function for each link in a link list. Yield
  *        if lots of links exist.
  *
- * The funcion 'func' will be called with a pointer to a link
+ * The function 'func' will be called with a pointer to a link
  * as first argument and 'arg' as second argument for each link
- * in the tree referred to by 'root'.
+ * in the tree referred to by 'root'. It should return the number of
+ * reductions the operator took to perform.
  *
  * It is assumed that:
  * - *yspp equals NULL on first call
@@ -1924,25 +1948,25 @@ void erts_link_list_foreach(ErtsLink *list,
  *                              *yspp should be NULL. When done *yspp
  *                              will be NULL.
  *
- * @param[in]     limit         Maximum amount of links to process
- *                              before yielding.
+ * @param[in]     reds          Reductions available to execute before yielding.
  *
- * @returns                     A non-zero value when all links has been
- *                              processed, and zero when more work is needed.
+ * @returns                     The unconsumed reductions when all links
+ *                              have been processed, and zero when more work
+ *                              is needed.
  *
  */
 int erts_link_list_foreach_yielding(ErtsLink *list,
-                                    void (*func)(ErtsLink *, void *),
+                                    ErtsLinkFunc func,
                                     void *arg,
                                     void **vyspp,
-                                    Sint limit);
+                                    Sint reds);
 
 /**
  *
  * @brief Delete all links from a link list and call a function for
  *        each link
  *
- * The funcion 'func' will be called with a pointer to a link
+ * The function 'func' will be called with a pointer to a link
  * as first argument and 'arg' as second argument for each link
  * in the tree referred to by 'root'.
  *
@@ -1955,7 +1979,7 @@ int erts_link_list_foreach_yielding(ErtsLink *list,
  *
  */
 void erts_link_list_foreach_delete(ErtsLink **list,
-                                   void (*func)(ErtsLink *, void *),
+                                   ErtsLinkFunc func,
                                    void *arg);
 
 /**
@@ -1963,9 +1987,10 @@ void erts_link_list_foreach_delete(ErtsLink **list,
  * @brief Delete all links from a link list and call a function for
  *        each link
  *
- * The funcion 'func' will be called with a pointer to a link
+ * The function 'func' will be called with a pointer to a link
  * as first argument and 'arg' as second argument for each link
- * in the tree referred to by 'root'.
+ * in the tree referred to by 'root'. It should return the number of
+ * reductions the operator took to perform.
  *
  * It is assumed that:
  * - *yspp equals NULL on first call
@@ -1988,18 +2013,18 @@ void erts_link_list_foreach_delete(ErtsLink **list,
  *                              *yspp should be NULL. When done *yspp
  *                              will be NULL.
  *
- * @param[in]     limit         Maximum amount of links to process
- *                              before yielding.
+ * @param[in]     reds          Reductions available to execute before yielding.
  *
- * @returns                     A non-zero value when all links has been
- *                              processed, and zero when more work is needed.
+ * @returns                     The unconsumed reductions when all links
+ *                              have been processed, and zero when more work
+ *                              is needed.
  *
  */
 int erts_link_list_foreach_delete_yielding(ErtsLink **list,
-                                           void (*func)(ErtsLink *, void *),
+                                           ErtsLinkFunc func,
                                            void *arg,
                                            void **vyspp,
-                                           Sint limit);
+                                           Sint reds);
 
 /*
  * --- Misc link operations ---
@@ -2011,7 +2036,7 @@ int erts_link_list_foreach_delete_yielding(ErtsLink **list,
  *
  * Can create all types of links
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'ref' is an internal ordinary reference if type is ERTS_MON_TYPE_PROC,
  *   ERTS_MON_TYPE_PORT, ERTS_MON_TYPE_TIME_OFFSET, or ERTS_MON_TYPE_RESOURCE
  * - 'ref' is NIL if type is ERTS_MON_TYPE_NODE or ERTS_MON_TYPE_NODES
@@ -2081,7 +2106,7 @@ ERTS_GLB_INLINE int erts_link_is_in_table(ErtsLink *lnk);
  * When both link halves part of the link have been released the link
  * structure will be deallocated.
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'lnk' link is not part of any list or tree
  * - 'lnk' is not referred to by any other structures
  * If the above are not true, bad things will happen.
@@ -2098,7 +2123,7 @@ ERTS_GLB_INLINE void erts_link_release(ErtsLink *lnk);
  * Release both halves of a link simultaneously and deallocate
  * the structure.
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - Neither of the parts of the link are part of any list or tree
  * - Neither of the parts of the link or the link data structure
  *   are referred to by any other structures
@@ -2113,7 +2138,7 @@ ERTS_GLB_INLINE void erts_link_release_both(ErtsLinkData *ldp);
  *
  * @brief Insert link in dist link list
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'lnk' link is not part of any list or tree
  * If the above is not true, bad things will happen.
  *
@@ -2134,7 +2159,7 @@ ERTS_GLB_INLINE int erts_link_dist_insert(ErtsLink *lnk, ErtsMonLnkDist *dist);
  *
  * @brief Delete link from dist link list
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'lnk' link earler has been inserted into 'dist'
  * If the above is not true, bad things will happen.
  *
@@ -2172,7 +2197,7 @@ erts_link_set_dead_dist(ErtsLink *lnk, Eterm nodename);
  * whole size of the link data structure is returned; otherwise,
  * half of the size is returned.
  *
- * When the funcion is called it is assumed that:
+ * When the function is called it is assumed that:
  * - 'lnk' has not been released
  * If the above is not true, bad things will happen.
  *
@@ -2351,4 +2376,10 @@ erts_link_dist_delete(ErtsLink *lnk)
 
 #endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
 
+void
+erts_debug_link_tree_destroying_foreach(ErtsLink *root,
+                                        ErtsLinkFunc func,
+                                        void *arg,
+                                        void *vysp);
+
 #endif /* ERL_MONITOR_LINK_H__ */
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index ee6e6085b6..1fbe362330 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -707,6 +707,46 @@ error:
     return reds;
 }
 
+/** @brief Create a message with the content of process independent \c msg_env.
+ *  Invalidates \c msg_env.
+ */
+ErtsMessage* erts_create_message_from_nif_env(ErlNifEnv* msg_env)
+{
+    struct enif_msg_environment_t* menv = (struct enif_msg_environment_t*)msg_env;
+    ErtsMessage* mp;
+
+    flush_env(msg_env);
+    mp = erts_alloc_message(0, NULL);
+    mp->data.heap_frag = menv->env.heap_frag;
+    ASSERT(mp->data.heap_frag == MBUF(&menv->phony_proc));
+    if (mp->data.heap_frag != NULL) {
+        /* Move all offheap's from phony proc to the first fragment.
+           Quick and dirty... */
+        ASSERT(!is_offheap(&mp->data.heap_frag->off_heap));
+        mp->data.heap_frag->off_heap = MSO(&menv->phony_proc);
+        clear_offheap(&MSO(&menv->phony_proc));
+        menv->env.heap_frag = NULL;
+        MBUF(&menv->phony_proc) = NULL;
+    }
+    return mp;
+}
+
+static ERTS_INLINE ERL_NIF_TERM make_copy(ErlNifEnv* dst_env,
+                                          ERL_NIF_TERM src_term,
+                                          Uint *cpy_szp)
+{
+    Uint sz;
+    Eterm* hp;
+    /*
+     * No preserved sharing allowed as long as literals are also preserved.
+     * Process independent environment can not be reached by purge.
+     */
+    sz = size_object(src_term);
+    if (cpy_szp)
+        *cpy_szp += sz;
+    hp = alloc_heap(dst_env, sz);
+    return copy_struct(src_term, sz, &hp, &MSO(dst_env->proc));
+}
 
 int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
 	      ErlNifEnv* msg_env, ERL_NIF_TERM msg)
@@ -720,6 +760,7 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
     Eterm from;
     Eterm receiver = to_pid->pid;
     int scheduler;
+    Uint copy_sz = 0;
 
     execution_state(env, &c_p, &scheduler);
 
@@ -783,14 +824,14 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
                 stoken = NIL;
             }
 #endif
-            token = enif_make_copy(msg_env, stoken);
+            token = make_copy(msg_env, stoken, &copy_sz);
 
 #ifdef USE_VM_PROBES
             if (DT_UTAG_FLAGS(c_p) & DT_UTAG_SPREADING) {
                 if (is_immed(DT_UTAG(c_p)))
                     utag = DT_UTAG(c_p);
                 else
-                    utag = enif_make_copy(msg_env, DT_UTAG(c_p));
+                    utag = make_copy(msg_env, DT_UTAG(c_p), &copy_sz);
             }
             if (DTRACE_ENABLED(message_send)) {
                 if (have_seqtrace(stoken)) {
@@ -803,20 +844,8 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
             }
 #endif
         }
-        flush_env(msg_env);
-        mp = erts_alloc_message(0, NULL);
+        mp = erts_create_message_from_nif_env(msg_env);
         ERL_MESSAGE_TOKEN(mp) = token;
-        mp->data.heap_frag = menv->env.heap_frag;
-        ASSERT(mp->data.heap_frag == MBUF(&menv->phony_proc));
-        if (mp->data.heap_frag != NULL) {
-            /* Move all offheap's from phony proc to the first fragment.
-               Quick and dirty... */
-            ASSERT(!is_offheap(&mp->data.heap_frag->off_heap));
-            mp->data.heap_frag->off_heap = MSO(&menv->phony_proc);
-            clear_offheap(&MSO(&menv->phony_proc));
-            menv->env.heap_frag = NULL;
-            MBUF(&menv->phony_proc) = NULL;
-        }
     } else {
         erts_literal_area_t litarea;
 	ErlOffHeap *ohp;
@@ -824,6 +853,7 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
         Uint sz;
         INITIALIZE_LITERAL_PURGE_AREA(litarea);
         sz = size_object_litopt(msg, &litarea);
+        copy_sz += sz;
 	if (c_p && !env->tracee) {
 	    full_flush_env(env);
 	    mp = erts_alloc_message_heap(rp, &rp_locks, sz, &hp, &ohp);
@@ -856,6 +886,12 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
             trace_send(c_p, receiver, msg);
 	    full_cache_env(env);
 	}
+        if (c_p && scheduler > 0 && copy_sz > ERTS_MSG_COPY_WORDS_PER_REDUCTION) {
+            Uint reds = copy_sz / ERTS_MSG_COPY_WORDS_PER_REDUCTION;
+            if (reds > CONTEXT_REDS)
+                reds = CONTEXT_REDS;
+            BUMP_REDS(c_p, (int) reds);
+        }
     }
     else {
         /* This clause is taken when the nif is called in the context
@@ -924,6 +960,7 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
         erts_queue_message(rp, rp_locks, mp, msg, from);
 
 done:
+
     if (c_p == rp)
 	rp_locks &= ~ERTS_PROC_LOCK_MAIN;
     if (rp_locks & ~lc_locks)
@@ -987,7 +1024,7 @@ static Eterm call_whereis(ErlNifEnv *env, Eterm name)
     int scheduler;
 
     execution_state(env, &c_p, &scheduler);
-    ASSERT((c_p && scheduler) || (!c_p && !scheduler));
+    ASSERT(scheduler || !c_p);
 
     if (scheduler < 0) {
         /* dirty scheduler */
@@ -1036,18 +1073,9 @@ int enif_whereis_port(ErlNifEnv *env, ERL_NIF_TERM name, ErlNifPort *port)
 
 ERL_NIF_TERM enif_make_copy(ErlNifEnv* dst_env, ERL_NIF_TERM src_term)
 {
-    Uint sz;
-    Eterm* hp;
-    /*
-     * No preserved sharing allowed as long as literals are also preserved.
-     * Process independent environment can not be reached by purge.
-     */
-    sz = size_object(src_term);
-    hp = alloc_heap(dst_env, sz);
-    return copy_struct(src_term, sz, &hp, &MSO(dst_env->proc));
+    return make_copy(dst_env, src_term, NULL);
 }
 
-
 #ifdef DEBUG
 static int is_offheap(const ErlOffHeap* oh)
 {
@@ -1072,6 +1100,17 @@ int enif_get_local_pid(ErlNifEnv* env, ERL_NIF_TERM term, ErlNifPid* pid)
     return 0;
 }
 
+void enif_set_pid_undefined(ErlNifPid* pid)
+{
+    pid->pid = am_undefined;
+}
+
+int enif_is_pid_undefined(const ErlNifPid* pid)
+{
+    ASSERT(pid->pid == am_undefined || is_internal_pid(pid->pid));
+    return pid->pid == am_undefined;
+}
+
 int enif_get_local_port(ErlNifEnv* env, ERL_NIF_TERM term, ErlNifPort* port)
 {
     if (is_internal_port(term)) {
@@ -1136,6 +1175,47 @@ int enif_is_number(ErlNifEnv* env, ERL_NIF_TERM term)
     return is_number(term);
 }
 
+ErlNifTermType enif_term_type(ErlNifEnv* env, ERL_NIF_TERM term) {
+    (void)env;
+
+    switch (tag_val_def(term)) {
+    case ATOM_DEF:
+        return ERL_NIF_TERM_TYPE_ATOM;
+    case BINARY_DEF:
+        return ERL_NIF_TERM_TYPE_BITSTRING;
+    case FLOAT_DEF:
+        return ERL_NIF_TERM_TYPE_FLOAT;
+    case EXPORT_DEF:
+    case FUN_DEF:
+        return ERL_NIF_TERM_TYPE_FUN;
+    case BIG_DEF:
+    case SMALL_DEF:
+        return ERL_NIF_TERM_TYPE_INTEGER;
+    case LIST_DEF:
+    case NIL_DEF:
+        return ERL_NIF_TERM_TYPE_LIST;
+    case MAP_DEF:
+        return ERL_NIF_TERM_TYPE_MAP;
+    case EXTERNAL_PID_DEF:
+    case PID_DEF:
+        return ERL_NIF_TERM_TYPE_PID;
+    case EXTERNAL_PORT_DEF:
+    case PORT_DEF:
+        return ERL_NIF_TERM_TYPE_PORT;
+    case EXTERNAL_REF_DEF:
+    case REF_DEF:
+        return ERL_NIF_TERM_TYPE_REFERENCE;
+    case TUPLE_DEF:
+        return ERL_NIF_TERM_TYPE_TUPLE;
+    default:
+        /* tag_val_def() aborts on its own when passed complete garbage, but
+         * it's possible that the user has given us garbage that just happens
+         * to match something that tag_val_def() accepts but we don't, like
+         * binary match contexts. */
+        ERTS_INTERNAL_ERROR("Invalid term passed to enif_term_type");
+    }
+}
+
 static void aligned_binary_dtor(struct enif_tmp_obj_t* obj)
 {
     erts_free_aligned_binary_bytes_extra((byte*)obj, obj->allocator);
@@ -1264,11 +1344,18 @@ unsigned char* enif_make_new_binary(ErlNifEnv* env, size_t size,
 int enif_term_to_binary(ErlNifEnv *dst_env, ERL_NIF_TERM term,
                         ErlNifBinary *bin)
 {
-    Sint size;
+    Uint size;
     byte *bp;
     Binary* refbin;
 
-    size = erts_encode_ext_size(term);
+    switch (erts_encode_ext_size(term, &size)) {
+    case ERTS_EXT_SZ_SYSTEM_LIMIT:
+        return 0; /* system limit */
+    case ERTS_EXT_SZ_YIELD:
+        ERTS_INTERNAL_ERROR("Unexpected yield");
+    case ERTS_EXT_SZ_OK:
+        break;
+    }
     if (!enif_alloc_binary(size, bin))
         return 0;
 
@@ -2346,18 +2433,42 @@ rmon_refc_read(ErtsResourceMonitors *rms)
     return rms->refc & ERTS_RESOURCE_REFC_MASK;
 }
 
-static void dtor_demonitor(ErtsMonitor* mon, void* context)
+static int dtor_demonitor(ErtsMonitor* mon, void* context, Sint reds)
 {
     ASSERT(erts_monitor_is_origin(mon));
     ASSERT(is_internal_pid(mon->other.item));
 
     erts_proc_sig_send_demonitor(mon);
+    return 1;
 }
 
-#  define NIF_RESOURCE_DTOR &nif_resource_dtor
+#ifdef DEBUG
+int erts_dbg_is_resource_dying(ErtsResource* resource)
+{
+    return resource->monitors && rmon_is_dying(resource->monitors);
+}
+#endif
+
+#define NIF_RESOURCE_DTOR &nif_resource_dtor_prologue
 
-static int nif_resource_dtor(Binary* bin)
+static void run_resource_dtor(void* vbin);
+ 
+static int nif_resource_dtor_prologue(Binary* bin)
+{
+    /*
+     * Schedule user resource destructor as aux work to get a context
+     * where we know what locks we have for example.
+     */
+    Uint sched_id = erts_get_scheduler_id();
+    if (!sched_id)
+        sched_id = 1;
+    erts_schedule_misc_aux_work(sched_id, run_resource_dtor, bin);
+    return 0; /* don't free */
+}
+ 
+static void run_resource_dtor(void* vbin)
 {
+    Binary* bin = (Binary*) vbin;
     ErtsResource* resource = (ErtsResource*) ERTS_MAGIC_BIN_UNALIGNED_DATA(bin);
     ErlNifResourceType* type = resource->type;
     ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(bin) == NIF_RESOURCE_DTOR);
@@ -2389,11 +2500,11 @@ static int nif_resource_dtor(Binary* bin)
          * If resource->monitors->refc != 0 there are
          * outstanding references to the resource from
          * monitors that has not been removed yet.
-         * nif_resource_dtor() will be called again this
+         * nif_resource_dtor_prologue() will be called again when this
          * reference count reach zero.
          */
         if (refc != 0)
-            return 0; /* we'll be back... */
+            return; /* we'll be back... */
         erts_mtx_destroy(&rm->lock);
     }
 
@@ -2410,7 +2521,7 @@ static int nif_resource_dtor(Binary* bin)
 	steal_resource_type(type);
 	erts_free(ERTS_ALC_T_NIF, type);
     }
-    return 1;
+    erts_magic_binary_free((Binary*)vbin);
 }
 
 void erts_resource_stop(ErtsResource* resource, ErlNifEvent e,
@@ -2694,8 +2805,12 @@ int enif_consume_timeslice(ErlNifEnv* env, int percent)
 {
     Process *proc;
     Sint reds;
+    int sched;
 
-    execution_state(env, &proc, NULL);
+    execution_state(env, &proc, &sched);
+
+    if (sched < 0)
+        return 0; /* no-op on dirty scheduler */
 
     ASSERT(is_proc_bound(env) && percent >= 1 && percent <= 100);
     if (percent < 1) percent = 1;
@@ -3318,6 +3433,9 @@ int enif_monitor_process(ErlNifEnv* env, void* obj, const ErlNifPid* target_pid,
     }
     ASSERT(rsrc->type->down);
 
+    if (target_pid->pid == am_undefined)
+        return 1;
+
     ref = erts_make_ref_in_buffer(tmp);
 
     mdp = erts_monitor_create(ERTS_MON_TYPE_RESOURCE, ref,
@@ -3351,6 +3469,12 @@ int enif_monitor_process(ErlNifEnv* env, void* obj, const ErlNifPid* target_pid,
     return 0;
 }
 
+ERL_NIF_TERM enif_make_monitor_term(ErlNifEnv* env, const ErlNifMonitor* monitor)
+{
+    Eterm* hp = alloc_heap(env, ERTS_REF_THING_SIZE);
+    return erts_driver_monitor_to_ref(hp, monitor);
+}
+
 int enif_demonitor_process(ErlNifEnv* env, void* obj, const ErlNifMonitor* monitor)
 {
     ErtsResource* rsrc = DATA_TO_RESOURCE(obj);
diff --git a/erts/emulator/beam/erl_nif.h b/erts/emulator/beam/erl_nif.h
index 4c09496ef1..c250e8f683 100644
--- a/erts/emulator/beam/erl_nif.h
+++ b/erts/emulator/beam/erl_nif.h
@@ -54,10 +54,22 @@
 ** 2.13: 20.1 add enif_ioq
 ** 2.14: 21.0 add enif_ioq_peek_head, enif_(mutex|cond|rwlock|thread)_name
 **                enif_vfprintf, enif_vsnprintf, enif_make_map_from_arrays
+** 2.15: 22.0 ERL_NIF_SELECT_CANCEL, enif_select_(read|write)
+**            enif_term_type
 */
 #define ERL_NIF_MAJOR_VERSION 2
-#define ERL_NIF_MINOR_VERSION 14
-#define ERL_NIF_MIN_ERTS_VERSION "erts-10.0 (OTP-21)"
+#define ERL_NIF_MINOR_VERSION 15
+
+/*
+ * WHEN CHANGING INTERFACE VERSION, also replace erts version below with
+ * a ticket number e.g. "erts-@OTP-12345@". The syntax is the same as for
+ * runtime dependencies so multiple tickets should be separated with ":", e.g.
+ * "erts-@OTP-12345:OTP-54321@".
+ *
+ * If you're not on the OTP team, you should use a placeholder like
+ * erts-@MyName@ instead.
+ */
+#define ERL_NIF_MIN_ERTS_VERSION "erts-10.4"
 
 /*
  * The emulator will refuse to load a nif-lib with a major version
@@ -160,6 +172,8 @@ typedef int ErlNifEvent;
 #define ERL_NIF_SELECT_STOP_SCHEDULED (1 << 1)
 #define ERL_NIF_SELECT_INVALID_EVENT  (1 << 2)
 #define ERL_NIF_SELECT_FAILED         (1 << 3)
+#define ERL_NIF_SELECT_READ_CANCELLED (1 << 4)
+#define ERL_NIF_SELECT_WRITE_CANCELLED (1 << 5)
 
 typedef enum
 {
@@ -274,6 +288,26 @@ typedef enum {
     ERL_NIF_IOQ_NORMAL = 1
 } ErlNifIOQueueOpts;
 
+typedef enum {
+    ERL_NIF_TERM_TYPE_ATOM = 1,
+    ERL_NIF_TERM_TYPE_BITSTRING = 2,
+    ERL_NIF_TERM_TYPE_FLOAT = 3,
+    ERL_NIF_TERM_TYPE_FUN = 4,
+    ERL_NIF_TERM_TYPE_INTEGER = 5,
+    ERL_NIF_TERM_TYPE_LIST = 6,
+    ERL_NIF_TERM_TYPE_MAP = 7,
+    ERL_NIF_TERM_TYPE_PID = 8,
+    ERL_NIF_TERM_TYPE_PORT = 9,
+    ERL_NIF_TERM_TYPE_REFERENCE = 10,
+    ERL_NIF_TERM_TYPE_TUPLE = 11,
+
+    /* This is a dummy value intended to coax the compiler into warning about
+     * unhandled values in a switch even if all the above values have been
+     * handled. We can add new entries at any time so the user must always
+     * have a default case. */
+    ERL_NIF_TERM_TYPE__MISSING_DEFAULT_CASE__READ_THE_MANUAL = -1
+} ErlNifTermType;
+
 /*
  * Return values from enif_thread_type(). Negative values
  * reserved for specific types of non-scheduler threads.
diff --git a/erts/emulator/beam/erl_nif_api_funcs.h b/erts/emulator/beam/erl_nif_api_funcs.h
index 81f64f2390..d57f6ec97c 100644
--- a/erts/emulator/beam/erl_nif_api_funcs.h
+++ b/erts/emulator/beam/erl_nif_api_funcs.h
@@ -210,6 +210,13 @@ ERL_NIF_API_FUNC_DECL(int,enif_vsnprintf,(char*, size_t, const char *fmt, va_lis
 
 ERL_NIF_API_FUNC_DECL(int,enif_make_map_from_arrays,(ErlNifEnv *env, ERL_NIF_TERM keys[], ERL_NIF_TERM values[], size_t cnt, ERL_NIF_TERM *map_out));
 
+ERL_NIF_API_FUNC_DECL(int,enif_select_x,(ErlNifEnv* env, ErlNifEvent e, enum ErlNifSelectFlags flags, void* obj, const ErlNifPid* pid, ERL_NIF_TERM msg, ErlNifEnv* msg_env));
+ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_make_monitor_term,(ErlNifEnv* env, const ErlNifMonitor*));
+ERL_NIF_API_FUNC_DECL(void,enif_set_pid_undefined,(ErlNifPid* pid));
+ERL_NIF_API_FUNC_DECL(int,enif_is_pid_undefined,(const ErlNifPid* pid));
+
+ERL_NIF_API_FUNC_DECL(ErlNifTermType,enif_term_type,(ErlNifEnv* env, ERL_NIF_TERM term));
+
 /*
 ** ADD NEW ENTRIES HERE (before this comment) !!!
 */
@@ -392,6 +399,11 @@ ERL_NIF_API_FUNC_DECL(int,enif_make_map_from_arrays,(ErlNifEnv *env, ERL_NIF_TER
 #  define enif_vfprintf ERL_NIF_API_FUNC_MACRO(enif_vfprintf)
 #  define enif_vsnprintf ERL_NIF_API_FUNC_MACRO(enif_vsnprintf)
 #  define enif_make_map_from_arrays ERL_NIF_API_FUNC_MACRO(enif_make_map_from_arrays)
+#  define enif_select_x ERL_NIF_API_FUNC_MACRO(enif_select_x)
+#  define enif_make_monitor_term ERL_NIF_API_FUNC_MACRO(enif_make_monitor_term)
+#  define enif_set_pid_undefined ERL_NIF_API_FUNC_MACRO(enif_set_pid_undefined)
+#  define enif_is_pid_undefined ERL_NIF_API_FUNC_MACRO(enif_is_pid_undefined)
+#  define enif_term_type ERL_NIF_API_FUNC_MACRO(enif_term_type)
 
 /*
 ** ADD NEW ENTRIES HERE (before this comment)
@@ -623,6 +635,13 @@ static ERL_NIF_INLINE ERL_NIF_TERM enif_make_list9(ErlNifEnv* env,
 #ifndef enif_make_pid
 
 #  define enif_make_pid(ENV, PID) ((void)(ENV),(const ERL_NIF_TERM)((PID)->pid))
+#  define enif_compare_pids(A, B) (enif_compare((A)->pid,(B)->pid))
+#  define enif_select_read(ENV, E, OBJ, PID, MSG, MSG_ENV) \
+    enif_select_x(ENV, E, ERL_NIF_SELECT_READ | ERL_NIF_SELECT_CUSTOM_MSG, \
+                  OBJ, PID, MSG, MSG_ENV)
+#  define enif_select_write(ENV, E, OBJ, PID, MSG, MSG_ENV) \
+    enif_select_x(ENV, E, ERL_NIF_SELECT_WRITE | ERL_NIF_SELECT_CUSTOM_MSG, \
+                  OBJ, PID, MSG, MSG_ENV)
 
 #if SIZEOF_LONG == 8
 #  define enif_get_int64 enif_get_long
diff --git a/erts/emulator/beam/erl_node_tables.c b/erts/emulator/beam/erl_node_tables.c
index 18ed782ae3..50e9812534 100644
--- a/erts/emulator/beam/erl_node_tables.c
+++ b/erts/emulator/beam/erl_node_tables.c
@@ -177,6 +177,7 @@ dist_table_alloc(void *dep_tmpl)
     dep->connection_id			= 0;
     dep->state				= ERTS_DE_STATE_IDLE;
     dep->flags				= 0;
+    dep->opts                           = 0;
     dep->version			= 0;
 
     dep->mld                            = NULL;
@@ -201,6 +202,7 @@ dist_table_alloc(void *dep_tmpl)
     dep->send				= NULL;
     dep->cache				= NULL;
     dep->transcode_ctx                  = NULL;
+    dep->sequences                      = NULL;
 
     /* Link in */
 
@@ -658,6 +660,7 @@ erts_set_dist_entry_not_connected(DistEntry *dep)
 
     dep->state = ERTS_DE_STATE_IDLE;
     dep->flags = 0;
+    dep->opts = 0;
     dep->prev = NULL;
     dep->cid = NIL;
 
@@ -801,8 +804,8 @@ node_table_hash(void *venp)
 static int
 node_table_cmp(void *venp1, void *venp2)
 {
-    return ((((ErlNode *) venp1)->sysname == ((ErlNode *) venp2)->sysname
-	     && ((ErlNode *) venp1)->creation == ((ErlNode *) venp2)->creation)
+    return ((((ErlNode *) venp1)->sysname == ((ErlNode *) venp2)->sysname) &&
+            ((((ErlNode *) venp1)->creation == ((ErlNode *) venp2)->creation))
 	    ? 0
 	    : 1);
 }
@@ -816,11 +819,16 @@ node_table_alloc(void *venp_tmpl)
 
     node_entries++;
 
-    erts_refc_init(&enp->refc, -1);
+    erts_init_node_entry(enp, -1);
     enp->creation = ((ErlNode *) venp_tmpl)->creation;
     enp->sysname = ((ErlNode *) venp_tmpl)->sysname;
     enp->dist_entry = erts_find_or_insert_dist_entry(((ErlNode *) venp_tmpl)->sysname);
 
+#ifdef ERL_NODE_BOOKKEEP
+    erts_atomic_init_nob(&enp->slot, 0);
+    sys_memzero(enp->books, sizeof(struct erl_node_bookkeeping) * 1024);
+#endif
+
     return (void *) enp;
 }
 
@@ -873,7 +881,7 @@ erts_node_table_info(fmtfn_t to, void *to_arg)
 }
 
 
-ErlNode *erts_find_or_insert_node(Eterm sysname, Uint32 creation)
+ErlNode *erts_find_or_insert_node(Eterm sysname, Uint32 creation, Eterm book)
 {
     ErlNode *res;
     ErlNode ne;
@@ -883,9 +891,9 @@ ErlNode *erts_find_or_insert_node(Eterm sysname, Uint32 creation)
     erts_rwmtx_rlock(&erts_node_table_rwmtx);
     res = hash_get(&erts_node_table, (void *) &ne);
     if (res && res != erts_this_node) {
-	erts_aint_t refc = erts_refc_inctest(&res->refc, 0);
+	erts_aint_t refc = erts_ref_node_entry(res, 0, book);
 	if (refc < 2) /* New or pending delete */
-	    erts_refc_inc(&res->refc, 1);
+            erts_ref_node_entry(res, 1, THE_NON_VALUE);
     }
     erts_rwmtx_runlock(&erts_node_table_rwmtx);
     if (res)
@@ -895,9 +903,9 @@ ErlNode *erts_find_or_insert_node(Eterm sysname, Uint32 creation)
     res = hash_put(&erts_node_table, (void *) &ne);
     ASSERT(res);
     if (res != erts_this_node) {
-	erts_aint_t refc = erts_refc_inctest(&res->refc, 0);
+	erts_aint_t refc = erts_ref_node_entry(res, 0, book);
 	if (refc < 2) /* New or pending delete */
-	    erts_refc_inc(&res->refc, 1);
+	    erts_ref_node_entry(res, 1, THE_NON_VALUE);
     }
     erts_rwmtx_rwunlock(&erts_node_table_rwmtx);
     return res;
@@ -924,6 +932,8 @@ static void try_delete_node(void *venp)
      *
      * If refc > 0, the entry is in use. Keep the entry.
      */
+    erts_node_bookkeep(enp, THE_NON_VALUE, ERL_NODE_DEC,
+                       __FILE__, __LINE__);
     refc = erts_refc_dectest(&enp->refc, -1);
     if (refc == -1)
 	(void) hash_erase(&erts_node_table, (void *) enp);
@@ -1021,7 +1031,7 @@ erts_set_this_node(Eterm sysname, Uint creation)
     erts_deref_dist_entry(erts_this_dist_entry);
 
     erts_this_node = NULL; /* to make sure refc is bumped for this node */
-    erts_this_node = erts_find_or_insert_node(sysname, creation);
+    erts_this_node = erts_find_or_insert_node(sysname, creation, THE_NON_VALUE);
     erts_this_dist_entry = erts_this_node->dist_entry;
 
     erts_ref_dist_entry(erts_this_dist_entry);
@@ -1090,7 +1100,7 @@ void erts_init_node_tables(int dd_sec)
     node_tmpl.creation = 0;
     erts_this_node = hash_put(&erts_node_table, &node_tmpl);
      /* +1 for erts_this_node */
-    erts_refc_init(&erts_this_node->refc, 1);
+    erts_init_node_entry(erts_this_node, 1);
 
     ASSERT(erts_this_node->dist_entry != NULL);
     erts_this_dist_entry = erts_this_node->dist_entry;
@@ -1155,6 +1165,12 @@ void erts_lcnt_update_distribution_locks(int enable) {
  * can damage the real-time properties of the system.                        *
 \* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
+#ifdef ERL_NODE_BOOKKEEP
+#define ERTS_DBG_NC_ALLOC_TYPE ERTS_ALC_T_NC_STD
+#else
+#define ERTS_DBG_NC_ALLOC_TYPE ERTS_ALC_T_NC_TMP
+#endif
+
 #include "erl_db.h"
 
 #undef  INIT_AM
@@ -1177,11 +1193,14 @@ static Eterm AM_system;
 static Eterm AM_timer;
 static Eterm AM_delayed_delete_timer;
 static Eterm AM_thread_progress_delete_timer;
+static Eterm AM_sequence;
 static Eterm AM_signal;
+static Eterm AM_persistent_term;
 
 static void setup_reference_table(void);
 static Eterm reference_table_term(Uint **hpp, ErlOffHeap *ohp, Uint *szp);
 static void delete_reference_table(void);
+static void clear_system(void);
 
 #undef ERTS_MAX__
 #define ERTS_MAX__(A, B) ((A) > (B) ? (A) : (B))
@@ -1218,6 +1237,7 @@ typedef struct dist_referrer_ {
     int ctrl_ref;
     int system_ref;
     int signal_ref;
+    int sequence_ref;
     Eterm id;
     Uint creation;
     Uint id_heap[ID_HEAP_SIZE];
@@ -1233,11 +1253,11 @@ typedef struct inserted_bin_ {
     Binary *bin_val;
 } InsertedBin;
 
-static ReferredNode *referred_nodes;
+static ReferredNode *referred_nodes = NULL;
 static int no_referred_nodes;
-static ReferredDist *referred_dists;
+static ReferredDist *referred_dists = NULL;
 static int no_referred_dists;
-static InsertedBin *inserted_bins;
+static InsertedBin *inserted_bins = NULL;
 
 Eterm
 erts_get_node_and_dist_references(struct process *proc)
@@ -1272,9 +1292,16 @@ erts_get_node_and_dist_references(struct process *proc)
 	INIT_AM(delayed_delete_timer);
         INIT_AM(thread_progress_delete_timer);
 	INIT_AM(signal);
+	INIT_AM(sequence);
+	INIT_AM(persistent_term);
 	references_atoms_need_init = 0;
     }
 
+#ifdef ERL_NODE_BOOKKEEP
+    if (referred_nodes || referred_dists || inserted_bins)
+        delete_reference_table();
+#endif
+    
     setup_reference_table();
 
     /* Get term size */
@@ -1292,7 +1319,11 @@ erts_get_node_and_dist_references(struct process *proc)
 
     ASSERT(endp == hp);
 
+#ifndef ERL_NODE_BOOKKEEP
     delete_reference_table();
+#endif
+    
+    clear_system();
 
     erts_thr_progress_unblock();
     erts_proc_lock(proc, ERTS_PROC_LOCK_MAIN);
@@ -1309,8 +1340,9 @@ erts_get_node_and_dist_references(struct process *proc)
 #define TIMER_REF 8
 #define SYSTEM_REF 9
 #define SIGNAL_REF 10
+#define SEQUENCE_REF 11
 
-#define INC_TAB_SZ 10
+#define INC_TAB_SZ 11
 
 static void
 insert_dist_referrer(ReferredDist *referred_dist,
@@ -1326,7 +1358,7 @@ insert_dist_referrer(ReferredDist *referred_dist,
 	    break;
 
     if(!drp) {
-	drp = (DistReferrer *) erts_alloc(ERTS_ALC_T_NC_TMP,
+	drp = (DistReferrer *) erts_alloc(ERTS_DBG_NC_ALLOC_TYPE,
 					  sizeof(DistReferrer));
 	drp->next = referred_dist->referrers;
 	referred_dist->referrers = drp;
@@ -1344,6 +1376,7 @@ insert_dist_referrer(ReferredDist *referred_dist,
 	drp->ctrl_ref = 0;
 	drp->system_ref = 0;
         drp->signal_ref = 0;
+        drp->sequence_ref = 0;
     }
 
     switch (type) {
@@ -1353,6 +1386,7 @@ insert_dist_referrer(ReferredDist *referred_dist,
     case ETS_REF:	drp->ets_ref++;	        break;
     case SYSTEM_REF:	drp->system_ref++;	break;
     case SIGNAL_REF:	drp->signal_ref++;	break;
+    case SEQUENCE_REF:	drp->sequence_ref++;	break;
     default:		ASSERT(0);
     }
 }
@@ -1387,7 +1421,7 @@ insert_node_referrer(ReferredNode *referred_node, int type, Eterm id)
 	    break;
 
     if(!nrp) {
-	nrp = (NodeReferrer *) erts_alloc(ERTS_ALC_T_NC_TMP,
+	nrp = (NodeReferrer *) erts_alloc(ERTS_DBG_NC_ALLOC_TYPE,
 					  sizeof(NodeReferrer));
 	nrp->next = referred_node->referrers;
         ERTS_INIT_OFF_HEAP(&nrp->off_heap);
@@ -1501,7 +1535,8 @@ insert_offheap(ErlOffHeap *oh, int type, Eterm id)
 		    erts_match_prog_foreach_offheap((Binary *) u.mref->mb,
 						    insert_offheap2,
 						    (void *) &a);
-		    nib = erts_alloc(ERTS_ALC_T_NC_TMP, sizeof(InsertedBin));
+		    nib = erts_alloc(ERTS_DBG_NC_ALLOC_TYPE,
+                                     sizeof(InsertedBin));
 		    nib->bin_val = (Binary *) u.mref->mb;
 		    nib->next = inserted_bins;
 		    inserted_bins = nib;
@@ -1509,7 +1544,7 @@ insert_offheap(ErlOffHeap *oh, int type, Eterm id)
 		}
 	    }
             else if (IsSendCtxBinary(u.mref->mb)) {
-                ErtsSendContext* ctx = ERTS_MAGIC_BIN_DATA(u.mref->mb);
+                ErtsDSigSendContext* ctx = ERTS_MAGIC_BIN_DATA(u.mref->mb);
                 if (ctx->deref_dep)
                     insert_dist_entry(ctx->dep, type, id, 0);
             }
@@ -1544,28 +1579,18 @@ static void insert_monitor_data(ErtsMonitor *mon, int type, Eterm id)
     mdp->origin.flags |= ERTS_ML_FLG_DBG_VISITED;
 }
 
-static void insert_monitor(ErtsMonitor *mon, void *idp)
+static int insert_monitor(ErtsMonitor *mon, void *idp, Sint reds)
 {
     Eterm id = *((Eterm *) idp);
     insert_monitor_data(mon, MONITOR_REF, id);
+    return 1;
 }
 
-static void clear_visited_monitor(ErtsMonitor *mon, void *p)
+static int clear_visited_monitor(ErtsMonitor *mon, void *p, Sint reds)
 {
     ErtsMonitorData *mdp = erts_monitor_to_data(mon);
     mdp->origin.flags &= ~ERTS_ML_FLG_DBG_VISITED;
-}
-
-static void
-insert_p_monitors(ErtsPTabElementCommon *p)
-{
-    Eterm id = p->id;
-    erts_monitor_tree_foreach(p->u.alive.monitors,
-                              insert_monitor,
-                              (void *) &id);
-    erts_monitor_list_foreach(p->u.alive.lt_monitors,
-                              insert_monitor,
-                              (void *) &id);
+    return 1;
 }
 
 static void
@@ -1581,15 +1606,20 @@ insert_dist_monitors(DistEntry *dep)
     }
 }
 
+
+static int
+insert_sequence(DistSeqNode *seq, void *arg, Sint reds)
+{
+    ErtsDistExternal *edep = erts_get_dist_ext(&seq->hfrag);
+    insert_offheap(&seq->hfrag.off_heap, SEQUENCE_REF, *(Eterm*)arg);
+    insert_dist_entry(edep->dep, SEQUENCE_REF, *(Eterm*)arg, 0);
+    return 1;
+}
+
 static void
-clear_visited_p_monitors(ErtsPTabElementCommon *p)
+insert_dist_sequences(DistEntry *dep)
 {
-    erts_monitor_tree_foreach(p->u.alive.monitors,
-                              clear_visited_monitor,
-                              NULL);
-    erts_monitor_list_foreach(p->u.alive.lt_monitors,
-                              clear_visited_monitor,
-                              NULL);
+    erts_debug_dist_seq_tree_foreach(dep, insert_sequence, (void *) &dep->sysname);
 }
 
 static void
@@ -1621,23 +1651,18 @@ static void insert_link_data(ErtsLink *lnk, int type, Eterm id)
     ldp->a.flags |= ERTS_ML_FLG_DBG_VISITED;
 }
 
-static void insert_link(ErtsLink *lnk, void *idp)
+static int insert_link(ErtsLink *lnk, void *idp, Sint reds)
 {
     Eterm id = *((Eterm *) idp);
     insert_link_data(lnk, LINK_REF, id);
+    return 1;
 }
 
-static void clear_visited_link(ErtsLink *lnk, void *p)
+static int clear_visited_link(ErtsLink *lnk, void *p, Sint reds)
 {
     ErtsLinkData *ldp = erts_link_to_data(lnk);
     ldp->a.flags &= ~ERTS_ML_FLG_DBG_VISITED;
-}
-
-static void
-insert_p_links(ErtsPTabElementCommon *p)
-{
-    Eterm id = p->id;
-    erts_link_tree_foreach(p->u.alive.links, insert_link, (void *) &id);
+    return 1;
 }
 
 static void
@@ -1650,14 +1675,6 @@ insert_dist_links(DistEntry *dep)
 }
 
 static void
-clear_visited_p_links(ErtsPTabElementCommon *p)
-{
-    erts_link_tree_foreach(p->u.alive.links,
-                           clear_visited_link,
-                           NULL);
-}
-
-static void
 clear_visited_dist_links(DistEntry *dep)
 {
     if (dep->mld)
@@ -1770,11 +1787,9 @@ insert_message(ErtsMessage *msg, int type, Process *proc)
         else if (ERTS_SIG_IS_INTERNAL_MSG(msg))
             heap_frag = msg->data.heap_frag;
         else {
-            if (msg->data.dist_ext->dep)
-                insert_dist_entry(msg->data.dist_ext->dep,
-                                  type, proc->common.id, 0);
-            if (is_not_nil(ERL_MESSAGE_TOKEN(msg)))
-                heap_frag = erts_dist_ext_trailer(msg->data.dist_ext);
+            heap_frag = msg->data.heap_frag;
+            insert_dist_entry(erts_get_dist_ext(heap_frag)->dep,
+                              type, proc->common.id, 0);
         }
     }
     while (heap_frag) {
@@ -1798,24 +1813,148 @@ insert_sig_offheap(ErlOffHeap *ohp, void *arg)
     insert_offheap(ohp, SIGNAL_REF, proc->common.id);
 }
 
-static void
-insert_sig_monitor(ErtsMonitor *mon, void *arg)
+static int
+insert_sig_monitor(ErtsMonitor *mon, void *arg, Sint reds)
 {
     Process *proc = arg;
     insert_monitor_data(mon, SIGNAL_REF, proc->common.id);
+    return 1;
 }
 
-static void
-insert_sig_link(ErtsLink *lnk, void *arg)
+static int
+insert_sig_link(ErtsLink *lnk, void *arg, Sint reds)
 {
     Process *proc = arg;
     insert_link_data(lnk, SIGNAL_REF, proc->common.id);
+    return 1;
 }
 
 static void
-setup_reference_table(void)
+insert_sig_ext(ErtsDistExternal *edep, void *arg)
+{
+    Process *proc = arg;
+    insert_dist_entry(edep->dep, SIGNAL_REF, proc->common.id, 0);
+}
+
+static void
+insert_process(Process *proc)
 {
+    int mli;
+    ErtsMessage *msg_list[] = {proc->msg_frag};
     ErlHeapFragment *hfp;
+
+    /* Insert Heap */
+    insert_offheap(&(proc->off_heap),
+                   HEAP_REF,
+                   proc->common.id);
+    /* Insert heap fragments buffers */
+    for(hfp = proc->mbuf; hfp; hfp = hfp->next)
+        insert_offheap(&(hfp->off_heap),
+                       HEAP_REF,
+                       proc->common.id);
+
+    /* Insert msg buffers */
+    for (mli = 0; mli < sizeof(msg_list)/sizeof(msg_list[0]); mli++) {
+        ErtsMessage *msg;
+        for (msg = msg_list[mli]; msg; msg = msg->next)
+            insert_message(msg, HEAP_REF, proc);
+    }
+
+    /* Insert signal queue */
+    erts_proc_sig_debug_foreach_sig(proc,
+                                    insert_sig_msg,
+                                    insert_sig_offheap,
+                                    insert_sig_monitor,
+                                    insert_sig_link,
+                                    insert_sig_ext,
+                                    (void *) proc);
+
+    /* Insert monitors and links... */
+    erts_debug_proc_monitor_link_foreach(proc,
+                                         insert_monitor,
+                                         insert_link,
+                                         (void *) &proc->common.id);
+
+    {
+        DistEntry *dep = ERTS_PROC_GET_DIST_ENTRY(proc);
+        if (dep)
+            insert_dist_entry(dep,
+                              CTRL_REF,
+                              proc->common.id,
+                              0);
+    }
+}
+
+static void
+insert_process2(Process *proc, void *arg)
+{
+    insert_process(proc);
+}
+
+static void
+insert_dist_suspended_procs(DistEntry *dep)
+{
+    ErtsProcList *plist = erts_proclist_peek_first(dep->suspended);
+    while (plist) {
+        if (is_not_immed(plist->u.pid))
+            insert_process(plist->u.p);
+        plist = erts_proclist_peek_next(dep->suspended, plist);
+    }
+}
+
+static void clear_process(Process *proc);
+
+static void
+clear_dist_suspended_procs(DistEntry *dep)
+{
+    ErtsProcList *plist = erts_proclist_peek_first(dep->suspended);
+    while (plist) {
+        if (is_not_immed(plist->u.pid))
+            clear_process(plist->u.p);
+        plist = erts_proclist_peek_next(dep->suspended, plist);
+    }
+}
+
+static void
+insert_persistent_term(ErlOffHeap *ohp, void *arg)
+{
+    Eterm heap[3];
+    insert_offheap(ohp, SYSTEM_REF,
+                   TUPLE2(&heap[0], AM_system, AM_persistent_term));
+}
+
+static void
+insert_ets_offheap_thr_prgr(ErlOffHeap *ohp, void *arg)
+{
+    Eterm heap[3];
+    insert_offheap(ohp, ETS_REF,
+                   TUPLE2(&heap[0], AM_system, AM_ets));
+}
+
+#ifdef ERL_NODE_BOOKKEEP
+void
+erts_node_bookkeep(ErlNode *np, Eterm term, int what, char *f, int l)
+{
+    erts_aint_t slot = (erts_atomic_inc_read_nob(&np->slot) - 1) % ERTS_BOOKKEEP_SIZE;
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    Eterm who = THE_NON_VALUE;
+    ASSERT(np);
+    np->books[slot].what = what;
+    np->books[slot].term = term;
+    np->books[slot].file = f;
+    np->books[slot].line = l;
+    if (esdp->current_process) {
+        who = esdp->current_process->common.id;
+    } else if (esdp->current_port) {
+        who = esdp->current_port->common.id;
+    }
+    np->books[slot].who = who;
+}
+#endif
+
+static void
+setup_reference_table(void)
+{
     DistEntry *dep;
     HashInfo hi;
     int i, max;
@@ -1824,14 +1963,14 @@ setup_reference_table(void)
     inserted_bins = NULL;
 
     hash_get_info(&hi, &erts_node_table);
-    referred_nodes = erts_alloc(ERTS_ALC_T_NC_TMP,
+    referred_nodes = erts_alloc(ERTS_DBG_NC_ALLOC_TYPE,
 				hi.objs*sizeof(ReferredNode));
     no_referred_nodes = 0;
     hash_foreach(&erts_node_table, init_referred_node, NULL);
     ASSERT(no_referred_nodes == hi.objs);
 
     hash_get_info(&hi, &erts_dist_table);
-    referred_dists = erts_alloc(ERTS_ALC_T_NC_TMP,
+    referred_dists = erts_alloc(ERTS_DBG_NC_ALLOC_TYPE,
 				hi.objs*sizeof(ReferredDist));
     no_referred_dists = 0;
     hash_foreach(&erts_dist_table, init_referred_dist, NULL);
@@ -1865,53 +2004,12 @@ setup_reference_table(void)
     /* Insert all processes */
     for (i = 0; i < max; i++) {
 	Process *proc = erts_pix2proc(i);
-	if (proc) {
-	    int mli;
-	    ErtsMessage *msg_list[] = {proc->msg_frag};
-
-	    /* Insert Heap */
-	    insert_offheap(&(proc->off_heap),
-			   HEAP_REF,
-			   proc->common.id);
-	    /* Insert heap fragments buffers */
-	    for(hfp = proc->mbuf; hfp; hfp = hfp->next)
-		insert_offheap(&(hfp->off_heap),
-			       HEAP_REF,
-			       proc->common.id);
-
-	    /* Insert msg buffers */
-	    for (mli = 0; mli < sizeof(msg_list)/sizeof(msg_list[0]); mli++) {
-		ErtsMessage *msg;
-		for (msg = msg_list[mli]; msg; msg = msg->next)
-                    insert_message(msg, HEAP_REF, proc);
-	    }
-
-            /* Insert signal queue */
-            erts_proc_sig_debug_foreach_sig(proc,
-                                            insert_sig_msg,
-                                            insert_sig_offheap,
-                                            insert_sig_monitor,
-                                            insert_sig_link,
-                                            (void *) proc);
-
-	    /* Insert links */
-            insert_p_links(&proc->common);
-
-            /* Insert monitors */
-            insert_p_monitors(&proc->common);
-
-            {
-                DistEntry *dep = ERTS_PROC_GET_DIST_ENTRY(proc);
-                if (dep)
-                    insert_dist_entry(dep,
-                                      CTRL_REF,
-                                      proc->common.id,
-                                      0);
-            }
-	}
+	if (proc)
+            insert_process(proc);
     }
-    
-    erts_foreach_sys_msg_in_q(insert_sys_msg);
+    erts_debug_free_process_foreach(insert_process2, NULL);
+
+    erts_debug_foreach_sys_msg_in_q(insert_sys_msg);
 
     /* Insert all ports */
     max = erts_ptab_max(&erts_port);
@@ -1928,10 +2026,18 @@ setup_reference_table(void)
 	if (state & ERTS_PORT_SFLGS_DEAD)
 	    continue;
 
-	/* Insert links */
-        insert_p_links(&prt->common);
-	/* Insert monitors */
-        insert_p_monitors(&prt->common);
+        /* Insert links */
+        erts_link_tree_foreach(ERTS_P_LINKS(prt),
+                               insert_link,
+                               (void *) &prt->common.id);
+        /* Insert monitors */
+        erts_monitor_tree_foreach(ERTS_P_MONITORS(prt),
+                                  insert_monitor,
+                                  (void *) &prt->common.id);
+        /* Insert local target monitors */
+        erts_monitor_list_foreach(ERTS_P_LT_MONITORS(prt),
+                                  insert_monitor,
+                                  (void *) &prt->common.id);
 	/* Insert port data */
 	ohp = erts_port_data_offheap(prt);
 	if (ohp)
@@ -1983,16 +2089,22 @@ setup_reference_table(void)
     for(dep = erts_visible_dist_entries; dep; dep = dep->next) {
         insert_dist_links(dep);
         insert_dist_monitors(dep);
+        insert_dist_sequences(dep);
+        insert_dist_suspended_procs(dep);
     }
 
     for(dep = erts_hidden_dist_entries; dep; dep = dep->next) {
         insert_dist_links(dep);
         insert_dist_monitors(dep);
+        insert_dist_sequences(dep);
+        insert_dist_suspended_procs(dep);
     }
 
     for(dep = erts_pending_dist_entries; dep; dep = dep->next) {
         insert_dist_links(dep);
         insert_dist_monitors(dep);
+        insert_dist_sequences(dep);
+        insert_dist_suspended_procs(dep);
     }
 
     /* Not connected dist entries should not have any links,
@@ -2000,14 +2112,21 @@ setup_reference_table(void)
     for(dep = erts_not_connected_dist_entries; dep; dep = dep->next) {
         insert_dist_links(dep);
         insert_dist_monitors(dep);
+        insert_dist_sequences(dep);
+        insert_dist_suspended_procs(dep);
     }
 
     /* Insert all ets tables */
-    erts_db_foreach_table(insert_ets_table, NULL);
+    erts_db_foreach_table(insert_ets_table, NULL, 0);
+    erts_db_foreach_thr_prgr_offheap(insert_ets_offheap_thr_prgr, NULL);
 
     /* Insert all bif timers */
     erts_debug_bif_timer_foreach(insert_bif_timer, NULL);
 
+    /* Insert persistent term storage */
+    erts_debug_foreach_persistent_term_off_heap(insert_persistent_term,
+                                                NULL);
+
     /* Insert node table (references to dist) */
     hash_foreach(&erts_node_table, insert_erl_node, NULL);
 }
@@ -2173,6 +2292,10 @@ reference_table_term(Uint **hpp, ErlOffHeap *ohp, Uint *szp)
 		tup = MK_2TUP(AM_system, MK_UINT(drp->system_ref));
 		drl = MK_CONS(tup, drl);
 	    }
+            if(drp->sequence_ref) {
+		tup = MK_2TUP(AM_sequence, MK_UINT(drp->sequence_ref));
+		drl = MK_CONS(tup, drl);
+	    }
 	    if(drp->signal_ref) {
 		tup = MK_2TUP(AM_signal, MK_UINT(drp->signal_ref));
 		drl = MK_CONS(tup, drl);
@@ -2202,7 +2325,7 @@ reference_table_term(Uint **hpp, ErlOffHeap *ohp, Uint *szp)
                 tup = MK_2TUP(AM_ets, drp->id);
             }
 	    else {
-		ASSERT(!drp->ctrl_ref && drp->node_ref && !drp->signal_ref);
+		ASSERT(!drp->ctrl_ref && (drp->node_ref || drp->sequence_ref) && !drp->signal_ref);
 		ASSERT(is_atom(drp->id));
 		tup = MK_2TUP(drp->id, MK_UINT(drp->creation));
 		tup = MK_2TUP(AM_node, tup);
@@ -2247,11 +2370,16 @@ static void noop_sig_offheap(ErlOffHeap *oh, void *arg)
 
 }
 
+static void noop_sig_ext(ErtsDistExternal *ext, void *arg)
+{
+
+}
+
+
 static void
 delete_reference_table(void)
 {
-    DistEntry *dep;
-    int i, max;
+    int i;
     for(i = 0; i < no_referred_nodes; i++) {
 	NodeReferrer *nrp;
 	NodeReferrer *tnrp;
@@ -2260,11 +2388,13 @@ delete_reference_table(void)
             erts_cleanup_offheap(&nrp->off_heap);
 	    tnrp = nrp;
 	    nrp = nrp->next;
-	    erts_free(ERTS_ALC_T_NC_TMP, (void *) tnrp);
+	    erts_free(ERTS_DBG_NC_ALLOC_TYPE, (void *) tnrp);
 	}
     }
-    if (referred_nodes)
-	erts_free(ERTS_ALC_T_NC_TMP, (void *) referred_nodes);
+    if (referred_nodes) {
+	erts_free(ERTS_DBG_NC_ALLOC_TYPE, (void *) referred_nodes);
+        referred_nodes = NULL;
+    }
 
     for(i = 0; i < no_referred_dists; i++) {
 	DistReferrer *drp;
@@ -2273,33 +2403,57 @@ delete_reference_table(void)
 	while(drp) {
 	    tdrp = drp;
 	    drp = drp->next;
-	    erts_free(ERTS_ALC_T_NC_TMP, (void *) tdrp);
+	    erts_free(ERTS_DBG_NC_ALLOC_TYPE, (void *) tdrp);
 	}
     }
-    if (referred_dists)
-	erts_free(ERTS_ALC_T_NC_TMP, (void *) referred_dists);
+    if (referred_dists) {
+	erts_free(ERTS_DBG_NC_ALLOC_TYPE, (void *) referred_dists);
+        referred_dists = NULL;
+    }
     while(inserted_bins) {
 	InsertedBin *ib = inserted_bins;
 	inserted_bins = inserted_bins->next;
-	erts_free(ERTS_ALC_T_NC_TMP, (void *)ib);
+	erts_free(ERTS_DBG_NC_ALLOC_TYPE, (void *)ib);
     }
+}
+
+static void clear_process(Process *proc)
+{
+    erts_proc_sig_debug_foreach_sig(proc,
+                                    noop_sig_msg,
+                                    noop_sig_offheap,
+                                    clear_visited_monitor,
+                                    clear_visited_link,
+                                    noop_sig_ext,
+                                    (void *) proc);
 
-    /* Cleanup... */
+
+    /* Clear monitors and links... */
+    erts_debug_proc_monitor_link_foreach(proc,
+                                         clear_visited_monitor,
+                                         clear_visited_link,
+                                         (void *) &proc->common.id);
+}
+
+static void clear_process2(Process *proc, void *arg)
+{
+    clear_process(proc);
+}
+
+static void
+clear_system(void)
+{
+    DistEntry *dep;
+    int i, max;
+    /* Clear... */
 
     max = erts_ptab_max(&erts_proc);
     for (i = 0; i < max; i++) {
 	Process *proc = erts_pix2proc(i);
-	if (proc) {
-            clear_visited_p_links(&proc->common);
-            clear_visited_p_monitors(&proc->common);
-            erts_proc_sig_debug_foreach_sig(proc,
-                                            noop_sig_msg,
-                                            noop_sig_offheap,
-                                            clear_visited_monitor,
-                                            clear_visited_link,
-                                            (void *) proc);
-        }
+	if (proc)
+            clear_process(proc);
     }
+    erts_debug_free_process_foreach(clear_process2, NULL);
 
     max = erts_ptab_max(&erts_port);
     for (i = 0; i < max; i++) {
@@ -2314,28 +2468,42 @@ delete_reference_table(void)
 	if (state & ERTS_PORT_SFLGS_DEAD)
 	    continue;
 
-        clear_visited_p_links(&prt->common);
-        clear_visited_p_monitors(&prt->common);
+        /* Clear links */
+        erts_link_tree_foreach(ERTS_P_LINKS(prt),
+                               clear_visited_link,
+                               (void *) &prt->common.id);
+        /* Clear monitors */
+        erts_monitor_tree_foreach(ERTS_P_MONITORS(prt),
+                                  clear_visited_monitor,
+                                  (void *) &prt->common.id);
+        /* Clear local target monitors */
+        erts_monitor_list_foreach(ERTS_P_LT_MONITORS(prt),
+                                  clear_visited_monitor,
+                                  (void *) &prt->common.id);
     }
 
     for(dep = erts_visible_dist_entries; dep; dep = dep->next) {
         clear_visited_dist_links(dep);
         clear_visited_dist_monitors(dep);
+        clear_dist_suspended_procs(dep);
     }
 
     for(dep = erts_hidden_dist_entries; dep; dep = dep->next) {
         clear_visited_dist_links(dep);
         clear_visited_dist_monitors(dep);
+        clear_dist_suspended_procs(dep);
     }
 
     for(dep = erts_pending_dist_entries; dep; dep = dep->next) {
         clear_visited_dist_links(dep);
         clear_visited_dist_monitors(dep);
+        clear_dist_suspended_procs(dep);
     }
 
     for(dep = erts_not_connected_dist_entries; dep; dep = dep->next) {
         clear_visited_dist_links(dep);
         clear_visited_dist_monitors(dep);
+        clear_dist_suspended_procs(dep);
     }
 }
 
diff --git a/erts/emulator/beam/erl_node_tables.h b/erts/emulator/beam/erl_node_tables.h
index c44f1f8991..ffaafbbbea 100644
--- a/erts/emulator/beam/erl_node_tables.h
+++ b/erts/emulator/beam/erl_node_tables.h
@@ -95,14 +95,26 @@ enum dist_entry_state {
 struct ErtsDistOutputBuf_ {
 #ifdef DEBUG
     Uint dbg_pattern;
+    byte *ext_startp;
     byte *alloc_endp;
 #endif
     ErtsDistOutputBuf *next;
-    Uint hopefull_flags;
+    Binary *bin;
+    /* Pointers to the distribution header,
+       if NULL the distr header is in the extp */
+    byte *hdrp;
+    byte *hdr_endp;
+    /* Pointers to the ctl + payload */
     byte *extp;
     byte *ext_endp;
+    /* Start of payload and hopefull_flags, used by transcode */
+    Uint hopefull_flags;
     byte *msg_start;
-    byte data[1];
+    /* start of the ext buffer, this is not always the same as extp
+       as the atom cache handling can use less then the allotted buffer.
+       This value is needed to calculate the size of this output buffer.*/
+    byte *ext_start;
+
 };
 
 typedef struct {
@@ -137,6 +149,7 @@ struct dist_entry_ {
     enum dist_entry_state state;
     Uint32 flags;		/* Distribution flags, like hidden, 
 				   atom cache etc. */
+    Uint32 opts;
     unsigned long version;	/* Protocol version */
 
     ErtsMonLnkDist *mld;        /* Monitors and links */
@@ -161,14 +174,62 @@ struct dist_entry_ {
     ErtsThrPrgrLaterOp later_op;
 
     struct transcode_context* transcode_ctx;
+
+    struct dist_sequences *sequences; /* Ongoing distribution sequences */
+};
+
+/*
+#define ERL_NODE_BOOKKEEP
+ * Bookkeeping of ErlNode inc and dec operations to help debug refc problems.
+ * This is best used together with cerl -rr. Type the below into gdb:
+ * gdb:
+set pagination off
+set $i = 0
+set $node = referred_nodes[$node_ix].node
+while $i < $node->slot.counter
+ printf "%s:%d ", $node->books[$i].file, $node->books[$i].line
+ printf "%p: ", $node->books[$i].term
+ etp-1 $node->books[$i].who
+ printf " "
+ p $node->books[$i].what
+ set $i++
+end
+
+  * Then save that into a file called test.txt and run the below in
+  * an erlang shell in order to get all inc/dec that do not have a
+  * match.
+
+f(), {ok, B} = file:read_file("test.txt").
+Vs = [begin [Val, _, _, _, What] = All = string:lexemes(Ln, " "),{Val,What,All} end || Ln <- string:lexemes(B,"\n")].
+Accs = lists:foldl(fun({V,<<"ERL_NODE_INC">>,_},M) -> Val = maps:get(V,M,0), M#{ V => Val + 1 }; ({V,<<"ERL_NODE_DEC">>,_},M) -> Val = maps:get(V,M,0), M#{ V => Val - 1 } end, #{}, Vs).
+lists:usort(lists:filter(fun({V,N}) -> N /= 0 end, maps:to_list(Accs))).
+
+ * There are bound to be bugs in the the instrumentation code, but
+ * atleast this is a place to start when hunting refc bugs.
+ *
+ */
+#ifdef ERL_NODE_BOOKKEEP
+struct erl_node_bookkeeping {
+    Eterm who;
+    Eterm term;
+    char *file;
+    int line;
+    enum { ERL_NODE_INC, ERL_NODE_DEC } what;
 };
 
+#define ERTS_BOOKKEEP_SIZE (1024)
+#endif
+
 typedef struct erl_node_ {
   HashBucket hash_bucket;	/* Hash bucket */
   erts_refc_t refc;		/* Reference count */
   Eterm	sysname;		/* name@host atom for efficiency */
   Uint32 creation;		/* Creation */
   DistEntry *dist_entry;	/* Corresponding dist entry */
+#ifdef ERL_NODE_BOOKKEEP
+  struct erl_node_bookkeeping books[ERTS_BOOKKEEP_SIZE];
+  erts_atomic_t slot;
+#endif
 } ErlNode;
 
 
@@ -201,7 +262,7 @@ void erts_dist_table_info(fmtfn_t, void *);
 void erts_set_dist_entry_not_connected(DistEntry *);
 void erts_set_dist_entry_pending(DistEntry *);
 void erts_set_dist_entry_connected(DistEntry *, Eterm, Uint);
-ErlNode *erts_find_or_insert_node(Eterm, Uint32);
+ErlNode *erts_find_or_insert_node(Eterm, Uint32, Eterm);
 void erts_schedule_delete_node(ErlNode *);
 void erts_set_this_node(Eterm, Uint);
 Uint erts_node_table_size(void);
@@ -219,22 +280,68 @@ DistEntry *erts_dhandle_to_dist_entry(Eterm dhandle, Uint32* connection_id);
 Eterm erts_build_dhandle(Eterm **hpp, ErlOffHeap*, DistEntry*, Uint32 conn_id);
 Eterm erts_make_dhandle(Process *c_p, DistEntry*, Uint32 conn_id);
 
-ERTS_GLB_INLINE void erts_deref_node_entry(ErlNode *np);
+ERTS_GLB_INLINE void erts_init_node_entry(ErlNode *np, erts_aint_t val);
+#ifdef ERL_NODE_BOOKKEEP
+#define erts_ref_node_entry(NP, MIN, T) erts_ref_node_entry__((NP), (MIN), (T), __FILE__, __LINE__)
+#define erts_deref_node_entry(NP, T) erts_deref_node_entry__((NP), (T), __FILE__, __LINE__)
+ERTS_GLB_INLINE erts_aint_t erts_ref_node_entry__(ErlNode *np, int min_val, Eterm term, char *file, int line);
+ERTS_GLB_INLINE void erts_deref_node_entry__(ErlNode *np, Eterm term, char *file, int line);
+#else
+ERTS_GLB_INLINE erts_aint_t erts_ref_node_entry(ErlNode *np, int min_val, Eterm term);
+ERTS_GLB_INLINE void erts_deref_node_entry(ErlNode *np, Eterm term);
+#endif
 ERTS_GLB_INLINE void erts_de_rlock(DistEntry *dep);
 ERTS_GLB_INLINE void erts_de_runlock(DistEntry *dep);
 ERTS_GLB_INLINE void erts_de_rwlock(DistEntry *dep);
 ERTS_GLB_INLINE void erts_de_rwunlock(DistEntry *dep);
+#ifdef ERL_NODE_BOOKKEEP
+void erts_node_bookkeep(ErlNode *, Eterm , int, char *file, int line);
+#else
+#define erts_node_bookkeep(...)
+#endif
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
 ERTS_GLB_INLINE void
-erts_deref_node_entry(ErlNode *np)
+erts_init_node_entry(ErlNode *np, erts_aint_t val)
+{
+    erts_refc_init(&np->refc, val);
+}
+
+#ifdef ERL_NODE_BOOKKEEP
+
+ERTS_GLB_INLINE erts_aint_t
+erts_ref_node_entry__(ErlNode *np, int min_val, Eterm term, char *file, int line)
+{
+    erts_node_bookkeep(np, term, ERL_NODE_INC, file, line);
+    return erts_refc_inctest(&np->refc, min_val);
+}
+
+ERTS_GLB_INLINE void
+erts_deref_node_entry__(ErlNode *np, Eterm term, char *file, int line)
+{
+    erts_node_bookkeep(np, term, ERL_NODE_DEC, file, line);
+    if (erts_refc_dectest(&np->refc, 0) == 0)
+	erts_schedule_delete_node(np);
+}
+
+#else
+
+ERTS_GLB_INLINE erts_aint_t
+erts_ref_node_entry(ErlNode *np, int min_val, Eterm term)
+{
+    return erts_refc_inctest(&np->refc, min_val);
+}
+
+ERTS_GLB_INLINE void
+erts_deref_node_entry(ErlNode *np, Eterm term)
 {
-    ASSERT(np);
     if (erts_refc_dectest(&np->refc, 0) == 0)
 	erts_schedule_delete_node(np);
 }
 
+#endif
+
 ERTS_GLB_INLINE void
 erts_de_rlock(DistEntry *dep)
 {
diff --git a/erts/emulator/beam/erl_port.h b/erts/emulator/beam/erl_port.h
index 25976d38cc..039d8cf67a 100644
--- a/erts/emulator/beam/erl_port.h
+++ b/erts/emulator/beam/erl_port.h
@@ -1018,6 +1018,6 @@ int erts_port_output_async(Port *, Eterm, Eterm);
 /*
  * Signals from ports to ports. Used by sys drivers.
  */
-int erl_drv_port_control(Eterm, char, char*, ErlDrvSizeT);
+int erl_drv_port_control(Eterm, unsigned int, char*, ErlDrvSizeT);
 
 #endif
diff --git a/erts/emulator/beam/erl_port_task.c b/erts/emulator/beam/erl_port_task.c
index c8f2e88127..30a7875387 100644
--- a/erts/emulator/beam/erl_port_task.c
+++ b/erts/emulator/beam/erl_port_task.c
@@ -2094,7 +2094,7 @@ begin_port_cleanup(Port *pp, ErtsPortTask **execqp, int *processing_busy_q_p)
 
 	    erts_snprintf(port_str, sizeof(DTRACE_CHARBUF_NAME(port_str)), "%T", pp->common.id);
 	    while (plp2 != NULL) {
-		erts_snprintf(pid_str, sizeof(DTRACE_CHARBUF_NAME(pid_str)), "%T", plp2->pid);
+		erts_snprintf(pid_str, sizeof(DTRACE_CHARBUF_NAME(pid_str)), "%T", plp2->u.pid);
 		DTRACE2(process_port_unblocked, pid_str, port_str);
 	    }
 	}
diff --git a/erts/emulator/beam/erl_posix_str.c b/erts/emulator/beam/erl_posix_str.c
index 7b3e640d3f..5b515d6e78 100644
--- a/erts/emulator/beam/erl_posix_str.c
+++ b/erts/emulator/beam/erl_posix_str.c
@@ -171,6 +171,9 @@ erl_errno_id(error)
 #if defined(EIDRM) && (!defined(EINPROGRESS) || (EIDRM != EINPROGRESS))
     case EIDRM: return "eidrm";
 #endif
+#ifdef EILSEQ
+    case EILSEQ: return "eilseq";
+#endif
 #ifdef EINIT
     case EINIT: return "einit";
 #endif
diff --git a/erts/emulator/beam/erl_printf_term.c b/erts/emulator/beam/erl_printf_term.c
index 990a01b96f..67c486a0db 100644
--- a/erts/emulator/beam/erl_printf_term.c
+++ b/erts/emulator/beam/erl_printf_term.c
@@ -364,13 +364,13 @@ print_term(fmtfn_t fn, void* arg, Eterm obj, long *dcount) {
 	    int print_res;
 	    char def_buf[64];
 	    char *buf, *big_str;
-	    Uint sz = (Uint) big_decimal_estimate(wobj);
+	    Uint sz = (Uint) big_integer_estimate(wobj, 10);
 	    sz++;
 	    if (sz <= 64)
 		buf = &def_buf[0];
 	    else
 		buf = erts_alloc(ERTS_ALC_T_TMP, sz);
-	    big_str = erts_big_to_string(wobj, buf, sz);
+	    big_str = erts_big_to_string(wobj, 10, buf, sz);
 	    print_res = erts_printf_string(fn, arg, big_str);
 	    if (buf != &def_buf[0])
 		erts_free(ERTS_ALC_T_TMP, (void *) buf);
@@ -487,6 +487,8 @@ print_term(fmtfn_t fn, void* arg, Eterm obj, long *dcount) {
 			PRINT_UWORD(res, fn, arg, 'u', 0, 1, octet);
 			++bytep;
 			--bytesize;
+                        if ((*dcount)-- <= 0)
+                            goto L_done;
 		    }
 		    if (bitsize) {
 			Uint bits = bitoffs + bitsize;
@@ -521,6 +523,8 @@ print_term(fmtfn_t fn, void* arg, Eterm obj, long *dcount) {
 			PRINT_CHAR(res, fn, arg, octet);
 			++bytep;
 			--bytesize;
+                        if ((*dcount)-- <= 0)
+                            goto L_done;
 		    }
 		    PRINT_STRING(res, fn, arg, "\">>");
 		}
@@ -529,13 +533,34 @@ print_term(fmtfn_t fn, void* arg, Eterm obj, long *dcount) {
 	case EXPORT_DEF:
 	    {
 		Export* ep = *((Export **) (export_val(wobj) + 1));
-		Atom* module = atom_tab(atom_val(ep->info.mfa.module));
-		Atom* name = atom_tab(atom_val(ep->info.mfa.function));
+		long tdcount;
+		int tres;
 
 		PRINT_STRING(res, fn, arg, "fun ");
-		PRINT_BUF(res, fn, arg, module->name, module->len);
+
+		/* We pass a temporary 'dcount' and adjust the real one later to ensure
+		 * that the fun doesn't get split up between the module and function
+		 * name. */
+		tdcount = MAX_ATOM_SZ_LIMIT;
+		tres = print_atom_name(fn, arg, ep->info.mfa.module, &tdcount);
+		if (tres < 0) {
+		    res = tres;
+		    goto L_done;
+		}
+		*dcount -= (MAX_ATOM_SZ_LIMIT - tdcount);
+		res += tres;
+
 		PRINT_CHAR(res, fn, arg, ':');
-		PRINT_BUF(res, fn, arg, name->name, name->len);
+
+		tdcount = MAX_ATOM_SZ_LIMIT;
+		tres = print_atom_name(fn, arg, ep->info.mfa.function, &tdcount);
+		if (tres < 0) {
+		    res = tres;
+		    goto L_done;
+		}
+		*dcount -= (MAX_ATOM_SZ_LIMIT - tdcount);
+		res += tres;
+
 		PRINT_CHAR(res, fn, arg, '/');
 		PRINT_SWORD(res, fn, arg, 'd', 0, 1,
 			    (ErlPfSWord) ep->info.mfa.arity);
diff --git a/erts/emulator/beam/erl_proc_sig_queue.c b/erts/emulator/beam/erl_proc_sig_queue.c
index f343e984f7..d5e0e3b218 100644
--- a/erts/emulator/beam/erl_proc_sig_queue.c
+++ b/erts/emulator/beam/erl_proc_sig_queue.c
@@ -36,6 +36,7 @@
 #include "erl_port_task.h"
 #include "erl_trace.h"
 #include "beam_bp.h"
+#include "erl_binary.h"
 #include "big.h"
 #include "erl_gc.h"
 #include "bif.h"
@@ -80,6 +81,11 @@
 #define ERTS_SIG_Q_TYPE_ADJUST_TRACE_INFO \
     ERTS_SIG_Q_TYPE_MAX
 
+#define ERTS_SIG_IS_GEN_EXIT(sig)                                       \
+    (ERTS_PROC_SIG_TYPE(((ErtsSignal *) sig)->common.tag) == ERTS_SIG_Q_TYPE_GEN_EXIT)
+#define ERTS_SIG_IS_GEN_EXIT_EXTERNAL(sig)                              \
+    (ASSERT(ERTS_SIG_IS_GEN_EXIT(sig)),is_non_value(get_exit_signal_data(sig)->reason))
+
 Process *ERTS_WRITE_UNLIKELY(erts_dirty_process_signal_handler);
 Process *ERTS_WRITE_UNLIKELY(erts_dirty_process_signal_handler_high);
 Process *ERTS_WRITE_UNLIKELY(erts_dirty_process_signal_handler_max);
@@ -259,7 +265,7 @@ destroy_dist_proc_demonitor(ErtsSigDistProcDemonitor *dmon)
     Eterm ref = dmon->ref;
     if (is_external(ref)) {
         ExternalThing *etp = external_thing_ptr(ref);
-        erts_deref_node_entry(etp->node);
+        erts_deref_node_entry(etp->node, ref);
     }
     erts_free(ERTS_ALC_T_DIST_DEMONITOR, dmon);
 }
@@ -294,7 +300,8 @@ destroy_sig_dist_link_op(ErtsSigDistLinkOp *sdlnk)
 {
     ASSERT(is_external_pid(sdlnk->remote));
     ASSERT(boxed_val(sdlnk->remote) == &sdlnk->heap[0]);
-    erts_deref_node_entry(((ExternalThing *) &sdlnk->heap[0])->node);
+    erts_deref_node_entry(((ExternalThing *) &sdlnk->heap[0])->node,
+                          make_boxed(&sdlnk->heap[0]));
     erts_free(ERTS_ALC_T_SIG_DATA, sdlnk);
 }
 
@@ -604,7 +611,8 @@ proc_queue_signal(Process *c_p, Eterm pid, ErtsSignal *sig, int op)
 #endif
                 return 1;
             }
-            ASSERT(esdp->pending_signal.dbg_from == esdp->current_process);
+            ASSERT(esdp->pending_signal.dbg_from == esdp->current_process ||
+                   esdp->pending_signal.dbg_from == esdp->free_process);
             if (pend_sig != sig) {
                 /* Switch them and send previously pending signal instead */
                 Eterm pend_to = esdp->pending_signal.to;
@@ -936,29 +944,54 @@ erts_proc_sig_privqs_len(Process *c_p)
     return proc_sig_privqs_len(c_p, 0);
 }
 
+ErtsDistExternal *
+erts_proc_sig_get_external(ErtsMessage *msgp)
+{
+    if (ERTS_SIG_IS_EXTERNAL_MSG(msgp)) {
+        return erts_get_dist_ext(msgp->data.heap_frag);
+    } else if (ERTS_SIG_IS_NON_MSG(msgp) &&
+               ERTS_SIG_IS_GEN_EXIT(msgp) &&
+               ERTS_SIG_IS_GEN_EXIT_EXTERNAL(msgp)) {
+        ErtsDistExternal *edep;
+        ErtsExitSignalData *xsigd = get_exit_signal_data(msgp);
+        ASSERT(ERTS_PROC_SIG_TYPE(((ErtsSignal *) msgp)->common.tag) == ERTS_SIG_Q_TYPE_GEN_EXIT);
+        ASSERT(is_non_value(xsigd->reason));
+        if (msgp->hfrag.next == NULL)
+            edep = (ErtsDistExternal*)(xsigd + 1);
+        else
+            edep = erts_get_dist_ext(msgp->hfrag.next);
+        return edep;
+    }
+    return NULL;
+}
+
 static void do_seq_trace_output(Eterm to, Eterm token, Eterm msg);
 
 static void
 send_gen_exit_signal(Process *c_p, Eterm from_tag,
                      Eterm from, Eterm to,
-                     Sint16 op, Eterm reason, Eterm ref,
-                     Eterm token, int normal_kills)
+                     Sint16 op, Eterm reason, ErtsDistExternal *dist_ext,
+                     ErlHeapFragment *dist_ext_hfrag,
+                     Eterm ref, Eterm token, int normal_kills)
 {
     ErtsExitSignalData *xsigd;
     Eterm *hp, *start_hp, s_reason, s_ref, s_message, s_token, s_from;
     ErtsMessage *mp;
     ErlHeapFragment *hfrag;
     ErlOffHeap *ohp;
-    Uint hsz, from_sz, reason_sz, ref_sz, token_sz;
+    Uint hsz, from_sz, reason_sz, ref_sz, token_sz, dist_ext_sz;
     int seq_trace;
 #ifdef USE_VM_PROBES
     Eterm s_utag, utag;
     Uint utag_sz;
 #endif
 
+    ASSERT((is_value(reason) && dist_ext == NULL) ||
+           (is_non_value(reason) && dist_ext != NULL));
+
     ASSERT(is_immed(from_tag));
 
-    hsz = sizeof(ErtsExitSignalData)/sizeof(Uint);
+    hsz = sizeof(ErtsExitSignalData)/sizeof(Eterm);
 
     seq_trace = c_p && have_seqtrace(token);
     if (seq_trace)
@@ -977,33 +1010,44 @@ send_gen_exit_signal(Process *c_p, Eterm from_tag,
     hsz += utag_sz;
 #endif
 
-    token_sz = is_immed(token) ? 0 : size_object(token);
+    token_sz = size_object(token);
     hsz += token_sz;
 
-    from_sz = is_immed(from) ? 0 : size_object(from);
+    from_sz = size_object(from);
     hsz += from_sz;
 
-    reason_sz = is_immed(reason) ? 0 : size_object(reason);
-    hsz += reason_sz;
+    ref_sz = size_object(ref);
+    hsz += ref_sz;
 
-    switch (op) {
-    case ERTS_SIG_Q_OP_EXIT:
-    case ERTS_SIG_Q_OP_EXIT_LINKED: {
-        /* {'EXIT', From, Reason} */
-        hsz += 4; /* 3-tuple */
-        ref_sz = 0;
-        break;
-    }
-    case ERTS_SIG_Q_OP_MONITOR_DOWN: {
-        /* {'DOWN', Ref, process, From, Reason} */
-        hsz += 6; /* 5-tuple */
-        ref_sz = NC_HEAP_SIZE(ref);
-        hsz += ref_sz;
-        break;
-    }
-    default:
-        ERTS_INTERNAL_ERROR("Invalid exit signal op");
-        break;
+    reason_sz = 0; /* Set to silence gcc warning */
+
+    /* The reason was part of the control message,
+       just use copy it into the xsigd */
+    if (is_value(reason)) {
+        reason_sz = size_object(reason);
+        hsz += reason_sz;
+
+        switch (op) {
+        case ERTS_SIG_Q_OP_EXIT:
+        case ERTS_SIG_Q_OP_EXIT_LINKED: {
+            /* {'EXIT', From, Reason} */
+            hsz += 4; /* 3-tuple */
+            break;
+        }
+        case ERTS_SIG_Q_OP_MONITOR_DOWN: {
+            /* {'DOWN', Ref, process, From, Reason} */
+            hsz += 6; /* 5-tuple */
+            break;
+        }
+        default:
+            ERTS_INTERNAL_ERROR("Invalid exit signal op");
+            break;
+        }
+    } else if (dist_ext != NULL && dist_ext_hfrag == NULL) {
+        /* The message was not fragmented so we need to create space
+           for a single dist_ext element */
+        dist_ext_sz = erts_dist_ext_size(dist_ext) / sizeof(Eterm);
+        hsz += dist_ext_sz;
     }
 
     /*
@@ -1015,35 +1059,33 @@ send_gen_exit_signal(Process *c_p, Eterm from_tag,
     ohp = &hfrag->off_heap;
     start_hp = hp;
 
-    s_token = (is_immed(token)
-                ? token
-                : copy_struct(token, token_sz, &hp, ohp));
-
-    s_reason = (is_immed(reason)
-                ? reason
-                : copy_struct(reason, reason_sz, &hp, ohp));
+    s_token = copy_struct(token, token_sz, &hp, ohp);
+    s_from = copy_struct(from, from_sz, &hp, ohp);
+    s_ref = copy_struct(ref, ref_sz, &hp, ohp);
 
-    s_from = (is_immed(from)
-              ? from
-              : copy_struct(from, from_sz, &hp, ohp));
-
-    if (!ref_sz)
-        s_ref = NIL;
-    else
-        s_ref = STORE_NC(&hp, ohp, ref);
+    if (is_value(reason)) {
+        s_reason = copy_struct(reason, reason_sz, &hp, ohp);
 
-    switch (op) {
-    case ERTS_SIG_Q_OP_EXIT:
-    case ERTS_SIG_Q_OP_EXIT_LINKED:
-        /* {'EXIT', From, Reason} */
-        s_message = TUPLE3(hp, am_EXIT, s_from, s_reason);
-        hp += 4;
-        break;
-    case ERTS_SIG_Q_OP_MONITOR_DOWN:
-        /* {'DOWN', Ref, process, From, Reason} */
-        s_message = TUPLE5(hp, am_DOWN, s_ref, am_process, s_from, s_reason);
-        hp += 6;
-        break;
+        switch (op) {
+        case ERTS_SIG_Q_OP_EXIT:
+        case ERTS_SIG_Q_OP_EXIT_LINKED:
+            /* {'EXIT', From, Reason} */
+            s_message = TUPLE3(hp, am_EXIT, s_from, s_reason);
+            hp += 4;
+            break;
+        case ERTS_SIG_Q_OP_MONITOR_DOWN:
+            /* {'DOWN', Ref, process, From, Reason} */
+            s_message = TUPLE5(hp, am_DOWN, s_ref, am_process, s_from, s_reason);
+            hp += 6;
+            break;
+        default:
+            /* This cannot happen, used to silence gcc warning */
+            s_message = THE_NON_VALUE;
+            break;
+        }
+    } else {
+        s_message = THE_NON_VALUE;
+        s_reason = THE_NON_VALUE;
     }
 
 #ifdef USE_VM_PROBES
@@ -1061,11 +1103,13 @@ send_gen_exit_signal(Process *c_p, Eterm from_tag,
 
     hfrag->used_size = hp - start_hp;
 
-    xsigd = (ErtsExitSignalData *) (char *) hp;
+    xsigd = (ErtsExitSignalData *) hp;
 
     xsigd->message = s_message;
     xsigd->from = s_from;
     xsigd->reason = s_reason;
+    hfrag->next = dist_ext_hfrag;
+
     if (is_nil(s_ref))
         xsigd->u.normal_kills = normal_kills;
     else {
@@ -1073,6 +1117,15 @@ send_gen_exit_signal(Process *c_p, Eterm from_tag,
         xsigd->u.ref = s_ref;
     }
 
+    hp += sizeof(ErtsExitSignalData)/sizeof(Eterm);
+
+    if (dist_ext != NULL && dist_ext_hfrag == NULL && is_non_value(reason)) {
+        erts_make_dist_ext_copy(dist_ext, (ErtsDistExternal *) hp);
+        hp += dist_ext_sz;
+    }
+
+    ASSERT(hp == mp->hfrag.mem + mp->hfrag.alloc_size);
+
     if (seq_trace)
         do_seq_trace_output(to, s_token, s_message);
 
@@ -1205,7 +1258,19 @@ erts_proc_sig_send_exit(Process *c_p, Eterm from, Eterm to,
         from_tag = dep->sysname;
     }
     send_gen_exit_signal(c_p, from_tag, from, to, ERTS_SIG_Q_OP_EXIT,
-                         reason, NIL, token, normal_kills);
+                         reason, NULL, NULL, NIL, token, normal_kills);
+}
+
+void
+erts_proc_sig_send_dist_exit(DistEntry *dep,
+                             Eterm from, Eterm to,
+                             ErtsDistExternal *dist_ext,
+                             ErlHeapFragment *hfrag,
+                             Eterm reason, Eterm token)
+{
+    send_gen_exit_signal(NULL, dep->sysname, from, to, ERTS_SIG_Q_OP_EXIT,
+                         reason, dist_ext, hfrag, NIL, token, 0);
+
 }
 
 void
@@ -1219,7 +1284,7 @@ erts_proc_sig_send_link_exit(Process *c_p, Eterm from, ErtsLink *lnk,
     if (is_not_immed(reason) || is_not_nil(token)) {
         ASSERT(is_internal_pid(from) || is_internal_port(from));
         send_gen_exit_signal(c_p, from, from, to, ERTS_SIG_Q_OP_EXIT_LINKED,
-                             reason, NIL, token, 0);
+                             reason, NULL, NULL, NIL, token, 0);
     }
     else {
         /* Pass signal using old link structure... */
@@ -1274,10 +1339,13 @@ erts_proc_sig_send_unlink(Process *c_p, ErtsLink *lnk)
 void
 erts_proc_sig_send_dist_link_exit(DistEntry *dep,
                                   Eterm from, Eterm to,
+                                  ErtsDistExternal *dist_ext,
+                                  ErlHeapFragment *hfrag,
                                   Eterm reason, Eterm token)
 {
     send_gen_exit_signal(NULL, dep->sysname, from, to, ERTS_SIG_Q_OP_EXIT_LINKED,
-                         reason, NIL, token, 0);
+                         reason, dist_ext, hfrag, NIL, token, 0);
+
 }
 
 void
@@ -1299,16 +1367,18 @@ erts_proc_sig_send_dist_unlink(DistEntry *dep, Eterm from, Eterm to)
 void
 erts_proc_sig_send_dist_monitor_down(DistEntry *dep, Eterm ref,
                                      Eterm from, Eterm to,
+                                     ErtsDistExternal *dist_ext,
+                                     ErlHeapFragment *hfrag,
                                      Eterm reason)
 {
     Eterm monitored, heap[3];
-    if (is_atom(from)) 
+    if (is_atom(from))
         monitored = TUPLE2(&heap[0], from, dep->sysname);
     else
         monitored = from;
     send_gen_exit_signal(NULL, dep->sysname, monitored,
                          to, ERTS_SIG_Q_OP_MONITOR_DOWN,
-                         reason, ref, NIL, 0);    
+                         reason, dist_ext, hfrag, ref, NIL, 0);
 }
 
 void
@@ -1376,10 +1446,10 @@ erts_proc_sig_send_monitor_down(ErtsMonitor *mon, Eterm reason)
                    || is_internal_pid(from_tag)
                    || is_atom(from_tag));
             monitored = TUPLE2(&heap[0], name, node);
-        }    
+        }
         send_gen_exit_signal(NULL, from_tag, monitored,
                              to, ERTS_SIG_Q_OP_MONITOR_DOWN,
-                             reason, mdp->ref, NIL, 0);
+                             reason, NULL, NULL, mdp->ref, NIL, 0);
     }
     erts_monitor_release(mon);
 }
@@ -2037,7 +2107,6 @@ handle_exit_signal(Process *c_p, ErtsSigRecvTracing *tracing,
     if (type == ERTS_SIG_Q_TYPE_GEN_EXIT) {
         xsigd = get_exit_signal_data(sig);
         from = xsigd->from;
-        reason = xsigd->reason;
         if (op != ERTS_SIG_Q_OP_EXIT_LINKED)
             ignore = 0;
         else {
@@ -2062,6 +2131,18 @@ handle_exit_signal(Process *c_p, ErtsSigRecvTracing *tracing,
             }
         }
 
+        /* This GEN_EXIT was received from another node, decode the exit reason */
+        if (ERTS_SIG_IS_GEN_EXIT_EXTERNAL(sig))
+            erts_proc_sig_decode_dist(c_p, ERTS_PROC_LOCK_MAIN, sig, 1);
+
+        reason = xsigd->reason;
+
+        if (is_non_value(reason)) {
+            /* Bad distribution message; remove it from queue... */
+            ignore = !0;
+            destroy = !0;
+        }
+
         if (!ignore) {
 
             if ((op != ERTS_SIG_Q_OP_EXIT || reason != am_kill)
@@ -2929,6 +3010,104 @@ handle_sync_suspend(Process *c_p, ErtsMessage *mp)
     }
 }
 
+int
+erts_proc_sig_decode_dist(Process *proc, ErtsProcLocks proc_locks,
+                          ErtsMessage *msgp, int force_off_heap)
+{
+    ErtsHeapFactory factory;
+    ErlHeapFragment *hfrag;
+    Eterm msg;
+    Sint need;
+    ErtsDistExternal *edep;
+    ErtsExitSignalData *xsigd = NULL;
+
+    edep = erts_proc_sig_get_external(msgp);
+    if (!ERTS_SIG_IS_EXTERNAL_MSG(msgp))
+        xsigd = get_exit_signal_data(msgp);
+
+    if (edep->heap_size >= 0)
+	need = edep->heap_size;
+    else {
+	need = erts_decode_dist_ext_size(edep, 1, 1);
+	if (need < 0) {
+	    /* bad signal; remove it... */
+	    return 0;
+	}
+
+	edep->heap_size = need;
+    }
+
+    if (ERTS_SIG_IS_NON_MSG(msgp)) {
+        switch (ERTS_PROC_SIG_OP(ERL_MESSAGE_TERM(msgp))) {
+        case ERTS_SIG_Q_OP_EXIT:
+        case ERTS_SIG_Q_OP_EXIT_LINKED:
+            /* {'EXIT', From, Reason} */
+            need += 4;
+            break;
+        case ERTS_SIG_Q_OP_MONITOR_DOWN:
+            /* {'DOWN', Ref, process, From, Reason} */
+            need += 6; /* 5-tuple */
+            break;
+        default:
+            ERTS_INTERNAL_ERROR("Invalid exit signal op");
+            break;
+        }
+    }
+
+    hfrag = new_message_buffer(need);
+    erts_factory_heap_frag_init(&factory, hfrag);
+
+    ASSERT(edep->heap_size >= 0);
+
+    msg = erts_decode_dist_ext(&factory, edep, 1);
+
+    if (is_non_value(msg)) {
+        erts_factory_undo(&factory);
+        return 0;
+    }
+
+    if (ERTS_SIG_IS_MSG(msgp)) {
+        ERL_MESSAGE_TERM(msgp) = msg;
+        if (msgp->data.heap_frag == &msgp->hfrag)
+            msgp->data.heap_frag = ERTS_MSG_COMBINED_HFRAG;
+    } else {
+        switch (ERTS_PROC_SIG_OP(ERL_MESSAGE_TERM(msgp))) {
+        case ERTS_SIG_Q_OP_EXIT:
+        case ERTS_SIG_Q_OP_EXIT_LINKED:
+            /* {'EXIT', From, Reason} */
+            erts_reserve_heap(&factory, 4);
+            xsigd->message = TUPLE3(factory.hp, am_EXIT, xsigd->from, msg);
+            factory.hp += 4;
+            break;
+        case ERTS_SIG_Q_OP_MONITOR_DOWN:
+            /* {'DOWN', Ref, process, From, Reason} */
+            erts_reserve_heap(&factory, 6);
+            xsigd->message = TUPLE5(factory.hp, am_DOWN, xsigd->u.ref, am_process, xsigd->from, msg);
+            factory.hp += 6;
+            break;
+        }
+        xsigd->reason = msg;
+    }
+
+    erts_free_dist_ext_copy(edep);
+
+    erts_factory_close(&factory);
+
+    hfrag = factory.heap_frags;
+    while (hfrag->next)
+        hfrag = hfrag->next;
+
+    if (ERTS_SIG_IS_MSG(msgp) && msgp->data.heap_frag != ERTS_MSG_COMBINED_HFRAG) {
+        hfrag->next = msgp->data.heap_frag;
+        msgp->data.heap_frag = factory.heap_frags;
+    } else {
+        hfrag->next = msgp->hfrag.next;
+        msgp->hfrag.next = factory.heap_frags;
+    }
+
+    return 1;
+}
+
 void
 erts_proc_sig_handle_pending_suspend(Process *c_p)
 {
@@ -3045,7 +3224,7 @@ erts_proc_sig_handle_incoming(Process *c_p, erts_aint32_t *statep,
         ASSERT(ERTS_SIG_IS_NON_MSG(sig));
 
         tag = ((ErtsSignal *) sig)->common.tag;
- 
+
         switch (ERTS_PROC_SIG_OP(tag)) {
 
         case ERTS_SIG_Q_OP_EXIT:
@@ -3091,6 +3270,12 @@ erts_proc_sig_handle_incoming(Process *c_p, erts_aint32_t *statep,
                 break;
             case ERTS_SIG_Q_TYPE_GEN_EXIT:
                 xsigd = get_exit_signal_data(sig);
+
+                /* This GEN_EXIT was received from another node, decode the exit reason */
+                if (ERTS_SIG_IS_GEN_EXIT_EXTERNAL(sig))
+                    if (!erts_proc_sig_decode_dist(c_p, ERTS_PROC_LOCK_MAIN, sig, 1))
+                        break; /* Decode failed, just remove signal */
+
                 omon = erts_monitor_tree_lookup(ERTS_P_MONITORS(c_p),
                                                 xsigd->u.ref);
                 if (omon) {
@@ -3247,9 +3432,15 @@ erts_proc_sig_handle_incoming(Process *c_p, erts_aint32_t *statep,
                             erts_nif_demonitored((ErtsResource *) tmon->other.ptr);
                             cnt++;
                             break;
-                        case ERTS_MON_TYPE_SUSPEND:
-                            erts_resume(c_p, ERTS_PROC_LOCK_MAIN);
+                        case ERTS_MON_TYPE_SUSPEND: {
+                            ErtsMonitorSuspend *msp;
+                            erts_aint_t mstate;
+                            msp = (ErtsMonitorSuspend *) erts_monitor_to_data(tmon);
+                            mstate = erts_atomic_read_acqb(&msp->state);
+                            if (mstate & ERTS_MSUSPEND_STATE_FLG_ACTIVE)
+                                erts_resume(c_p, ERTS_PROC_LOCK_MAIN);
                             break;
+                        }
                         default:
                             break;
                         }
@@ -3590,9 +3781,10 @@ stretch_limit(Process *c_p, ErtsSigRecvTracing *tp,
 
 
 int
-erts_proc_sig_handle_exit(Process *c_p, int *redsp)
+erts_proc_sig_handle_exit(Process *c_p, Sint *redsp)
 {
-    int cnt, limit;
+    int cnt;
+    Sint limit;
     ErtsMessage *sig, ***next_nm_sig;
 
     ERTS_HDBG_CHECK_SIGNAL_PRIV_QUEUE(c_p, 0);
@@ -3671,9 +3863,9 @@ erts_proc_sig_handle_exit(Process *c_p, int *redsp)
             break;
 
         case ERTS_SIG_Q_OP_MONITOR: {
-            ErtsProcExitContext pectxt = {c_p, am_noproc};
+            ErtsProcExitContext pectxt = {c_p, am_noproc, NULL, NULL, NIL};
             erts_proc_exit_handle_monitor((ErtsMonitor *) sig,
-                                          (void *) &pectxt);
+                                          (void *) &pectxt, -1);
             cnt += 4;
             break;
         }
@@ -3687,7 +3879,7 @@ erts_proc_sig_handle_exit(Process *c_p, int *redsp)
 
         case ERTS_SIG_Q_OP_LINK: {
             ErtsProcExitContext pectxt = {c_p, am_noproc};
-            erts_proc_exit_handle_link((ErtsLink *) sig, (void *) &pectxt);
+            erts_proc_exit_handle_link((ErtsLink *) sig, (void *) &pectxt, -1);
             break;
         }
 
@@ -3784,6 +3976,9 @@ clear_seq_trace_token(ErtsMessage *sig)
             case ERTS_MON_TYPE_PROC:
             case ERTS_MON_TYPE_DIST_PROC:
             case ERTS_MON_TYPE_NODE:
+            case ERTS_MON_TYPE_NODES:
+            case ERTS_MON_TYPE_SUSPEND:
+            case ERTS_MON_TYPE_TIME_OFFSET:
                 break;
             default:
                 ERTS_INTERNAL_ERROR("Unexpected sig type");
@@ -3800,6 +3995,11 @@ clear_seq_trace_token(ErtsMessage *sig)
         case ERTS_SIG_Q_OP_LINK:
         case ERTS_SIG_Q_OP_UNLINK:
         case ERTS_SIG_Q_OP_TRACE_CHANGE_STATE:
+        case ERTS_SIG_Q_OP_GROUP_LEADER:
+        case ERTS_SIG_Q_OP_IS_ALIVE:
+        case ERTS_SIG_Q_OP_PROCESS_INFO:
+        case ERTS_SIG_Q_OP_SYNC_SUSPEND:
+        case ERTS_SIG_Q_OP_RPC:
             break;
 
         default:
@@ -3812,7 +4012,6 @@ clear_seq_trace_token(ErtsMessage *sig)
 void
 erts_proc_sig_clear_seq_trace_tokens(Process *c_p)
 {
-    ASSERT(erts_thr_progress_is_blocking());
     erts_proc_sig_fetch(c_p);
     ERTS_FOREACH_SIG_PRIVQS(c_p, sig, clear_seq_trace_token(sig));
 }
@@ -3852,6 +4051,7 @@ erts_proc_sig_signal_size(ErtsSignal *sig)
         case ERTS_MON_TYPE_DIST_PROC:
         case ERTS_MON_TYPE_NODE:
             size = erts_monitor_size((ErtsMonitor *) sig);
+            break;
         default:
             ERTS_INTERNAL_ERROR("Unexpected sig type");
             break;
@@ -4189,11 +4389,13 @@ handle_msg_tracing(Process *c_p, ErtsSigRecvTracing *tracing,
             return -1; /* Yield... */
         }
         if (ERTS_SIG_IS_EXTERNAL_MSG(sig)) {
-            cnt++;
-            if (!erts_decode_dist_message(c_p, ERTS_PROC_LOCK_MAIN,
-                                          sig, 0)) {
+            cnt += 50; /* Decode is expensive... */
+            if (!erts_proc_sig_decode_dist(c_p, ERTS_PROC_LOCK_MAIN,
+                                           sig, 0)) {
                 /* Bad dist message; remove it... */
                 remove_mq_m_sig(c_p, sig, next_sig, next_nm_sig);
+                sig->next = NULL;
+                erts_cleanup_messages(sig);
                 sig = *next_sig;
                 continue;
             }
@@ -4265,18 +4467,12 @@ erts_proc_sig_prep_msgq_for_inspection(Process *c_p,
 
 	if (ERTS_SIG_IS_EXTERNAL_MSG(mp)) {
 	    /* decode it... */
-	    if (mp->data.attached)
-		erts_decode_dist_message(rp, rp_locks, mp, !0);
-
-	    msg = ERL_MESSAGE_TERM(mp);
-
-	    if (is_non_value(msg)) {
+            if (!erts_proc_sig_decode_dist(rp, rp_locks, mp, !0)) {
 		ErtsMessage *bad_mp = mp;
 		/*
 		 * Bad distribution message; remove
 		 * it from the queue...
 		 */
-		ASSERT(!mp->data.attached);
 
 		ASSERT(*mpp == bad_mp);
 
@@ -4288,6 +4484,8 @@ erts_proc_sig_prep_msgq_for_inspection(Process *c_p,
 		erts_cleanup_messages(bad_mp);
 		continue;
 	    }
+
+	    msg = ERL_MESSAGE_TERM(mp);
 	}
 
 	ASSERT(is_value(msg));
@@ -4446,12 +4644,21 @@ debug_foreach_sig_fake_oh(Eterm term,
 
 }
 
+static void
+debug_foreach_sig_external(ErtsMessage *msgp,
+                           void (*ext_func)(ErtsDistExternal *, void *),
+                           void *arg)
+{
+    ext_func(erts_proc_sig_get_external(msgp), arg);
+}
+
 void
 erts_proc_sig_debug_foreach_sig(Process *c_p,
                                 void (*msg_func)(ErtsMessage *, void *),
                                 void (*oh_func)(ErlOffHeap *, void *),
-                                void (*mon_func)(ErtsMonitor *, void *),
-                                void (*lnk_func)(ErtsLink *, void *),
+                                ErtsMonitorFunc mon_func,
+                                ErtsLinkFunc lnk_func,
+                                void (*ext_func)(ErtsDistExternal *, void *),
                                 void *arg)
 {
     ErtsMessage *queue[] = {c_p->sig_qs.first, c_p->sig_qs.cont, c_p->sig_inq.first};
@@ -4460,10 +4667,10 @@ erts_proc_sig_debug_foreach_sig(Process *c_p,
     for (qix = 0; qix < sizeof(queue)/sizeof(queue[0]); qix++) {
         ErtsMessage *sig;
         for (sig = queue[qix]; sig; sig = sig->next) {
-            
-            if (ERTS_SIG_IS_MSG(sig))
+
+            if (ERTS_SIG_IS_MSG(sig)) {
                 msg_func(sig, arg);
-            else {
+            } else {
                 Eterm tag;
                 Uint16 type;
                 int op;
@@ -4482,18 +4689,23 @@ erts_proc_sig_debug_foreach_sig(Process *c_p,
                 case ERTS_SIG_Q_OP_MONITOR_DOWN:
                     switch (type) {
                     case ERTS_SIG_Q_TYPE_GEN_EXIT:
-                        debug_foreach_sig_heap_frags(&sig->hfrag, oh_func, arg);
+                        if (!ERTS_SIG_IS_GEN_EXIT_EXTERNAL(sig))
+                            debug_foreach_sig_heap_frags(&sig->hfrag, oh_func, arg);
+                        else {
+                            oh_func(&sig->hfrag.off_heap, arg);
+                            debug_foreach_sig_external(sig, ext_func, arg);
+                        }
                         break;
                     case ERTS_LNK_TYPE_PORT:
                     case ERTS_LNK_TYPE_PROC:
                     case ERTS_LNK_TYPE_DIST_PROC:
-                        lnk_func((ErtsLink *) sig, arg);
+                        lnk_func((ErtsLink *) sig, arg, -1);
                         break;
                     case ERTS_MON_TYPE_PORT:
                     case ERTS_MON_TYPE_PROC:
                     case ERTS_MON_TYPE_DIST_PROC:
                     case ERTS_MON_TYPE_NODE:
-                        mon_func((ErtsMonitor *) sig, arg);
+                        mon_func((ErtsMonitor *) sig, arg, -1);
                         break;
                     default:
                         ERTS_INTERNAL_ERROR("Unexpected sig type");
@@ -4514,7 +4726,7 @@ erts_proc_sig_debug_foreach_sig(Process *c_p,
                     /* Fall through... */
 
                 case ERTS_SIG_Q_OP_MONITOR:
-                    mon_func((ErtsMonitor *) sig, arg);
+                    mon_func((ErtsMonitor *) sig, arg, -1);
                     break;
 
                 case ERTS_SIG_Q_OP_UNLINK:
@@ -4526,7 +4738,7 @@ erts_proc_sig_debug_foreach_sig(Process *c_p,
                     /* Fall through... */
 
                 case ERTS_SIG_Q_OP_LINK:
-                    lnk_func((ErtsLink *) sig, arg);
+                    lnk_func((ErtsLink *) sig, arg, -1);
                     break;
 
                 case ERTS_SIG_Q_OP_GROUP_LEADER: {
diff --git a/erts/emulator/beam/erl_proc_sig_queue.h b/erts/emulator/beam/erl_proc_sig_queue.h
index 3fc2d06b2d..2b055e73bc 100644
--- a/erts/emulator/beam/erl_proc_sig_queue.h
+++ b/erts/emulator/beam/erl_proc_sig_queue.h
@@ -89,6 +89,7 @@
 #endif
 
 struct erl_mesg;
+struct erl_dist_external;
 
 typedef struct {
     struct erl_mesg *next;
@@ -212,6 +213,38 @@ erts_proc_sig_send_exit(Process *c_p, Eterm from, Eterm to,
 
 /**
  *
+ * @brief Send an exit signal to a process.
+ *
+ * This function is used instead of erts_proc_sig_send_link_exit()
+ * when the signal arrives via the distribution and
+ * therefore no link structure is available.
+ *
+ * @param[in]     dep           Distribution entry of channel
+ *                              that the signal arrived on.
+ *
+ * @param[in]     from          Identifier of sender.
+ *
+ * @param[in]     to            Identifier of receiver.
+ *
+ * @param[in]     dist_ext      The exit reason in external term format
+ *
+ * @param[in]     hfrag         Heap frag with trace token and dist_ext
+ *                              iff available, otherwise NULL.
+ *
+ * @param[in]     reason        Exit reason.
+ *
+ * @param[in]     token         Seq trace token.
+ *
+ */
+void
+erts_proc_sig_send_dist_exit(DistEntry *dep,
+                             Eterm from, Eterm to,
+                             ErtsDistExternal *dist_ext,
+                             ErlHeapFragment *hfrag,
+                             Eterm reason, Eterm token);
+
+/**
+ *
  * @brief Send an exit signal due to broken link to a process.
  *
  *
@@ -282,7 +315,7 @@ erts_proc_sig_send_unlink(Process *c_p, ErtsLink *lnk);
  *
  * This function is used instead of erts_proc_sig_send_link_exit()
  * when the signal arrives via the distribution and
- * no link structure is available.
+ * therefore no link structure is available.
  *
  * @param[in]     dep           Distribution entry of channel
  *                              that the signal arrived on.
@@ -291,6 +324,11 @@ erts_proc_sig_send_unlink(Process *c_p, ErtsLink *lnk);
  *
  * @param[in]     to            Identifier of receiver.
  *
+ * @param[in]     dist_ext      The exit reason in external term format
+ *
+ * @param[in]     hfrag         Heap frag with trace token and dist_ext
+ *                              iff available, otherwise NULL.
+ *
  * @param[in]     reason        Exit reason.
  *
  * @param[in]     token         Seq trace token.
@@ -299,6 +337,8 @@ erts_proc_sig_send_unlink(Process *c_p, ErtsLink *lnk);
 void
 erts_proc_sig_send_dist_link_exit(struct dist_entry_ *dep,
                                   Eterm from, Eterm to,
+                                  ErtsDistExternal *dist_ext,
+                                  ErlHeapFragment *hfrag,
                                   Eterm reason, Eterm token);
 
 /**
@@ -307,7 +347,7 @@ erts_proc_sig_send_dist_link_exit(struct dist_entry_ *dep,
  *
  * This function is used instead of erts_proc_sig_send_unlink()
  * when the signal arrives via the distribution and
- * no link structure is available.
+ * therefore no link structure is available.
  *
  * @param[in]     dep           Distribution entry of channel
  *                              that the signal arrived on.
@@ -380,7 +420,7 @@ erts_proc_sig_send_monitor(ErtsMonitor *mon, Eterm to);
  *
  * This function is used instead of erts_proc_sig_send_monitor_down()
  * when the signal arrives via the distribution and
- * no link structure is available.
+ * therefore no monitor structure is available.
  *
  * @param[in]     dep           Pointer to distribution entry
  *                              of channel that the signal
@@ -392,12 +432,19 @@ erts_proc_sig_send_monitor(ErtsMonitor *mon, Eterm to);
  *
  * @param[in]     to            Identifier of receiver.
  *
+ * @param[in]     dist_ext      The exit reason in external term format
+ *
+ * @param[in]     hfrag         Heap frag with trace token and dist_ext
+ *                              iff available, otherwise NULL.
+ *
  * @param[in]     reason        Exit reason.
  *
  */
 void
 erts_proc_sig_send_dist_monitor_down(DistEntry *dep, Eterm ref,
                                      Eterm from, Eterm to,
+                                     ErtsDistExternal *dist_ext,
+                                     ErlHeapFragment *hfrag,
                                      Eterm reason);
 
 /**
@@ -740,7 +787,7 @@ erts_proc_sig_handle_incoming(Process *c_p, erts_aint32_t *statep,
  *                              queue.
  */
 int
-erts_proc_sig_handle_exit(Process *c_p, int *redsp);
+erts_proc_sig_handle_exit(Process *c_p, Sint *redsp);
 
 /**
  *
@@ -962,6 +1009,34 @@ void
 erts_proc_sig_handle_pending_suspend(Process *c_p);
 
 /**
+ *
+ * @brief Decode the reason term in an external signal
+ *
+ * Any distributed signal with a payload only has the control
+ * message decoded by the dist entry. The final decode of the
+ * payload is done by the process when it inspects the signal
+ * by calling this function.
+ *
+ * This functions handles both messages and link/monitor exits.
+ *
+ * Return true if the decode was successful, false otherwise.
+ *
+ * @param[in]   c_p             Pointer to executing process
+ *
+ * @param[in]   proc_lock       Locks held by process. Should always be MAIN.
+ *
+ * @param[in]   msgp            The signal to decode
+ *
+ * @param[in]   force_off_heap  If the term should be forced to be off-heap
+ */
+int
+erts_proc_sig_decode_dist(Process *proc, ErtsProcLocks proc_locks,
+                          ErtsMessage *msgp, int force_off_heap);
+
+ErtsDistExternal *
+erts_proc_sig_get_external(ErtsMessage *msgp);
+
+/**
  * @brief Initialize this functionality
  */
 void erts_proc_sig_queue_init(void);
@@ -970,8 +1045,9 @@ void
 erts_proc_sig_debug_foreach_sig(Process *c_p,
                                 void (*msg_func)(ErtsMessage *, void *),
                                 void (*oh_func)(ErlOffHeap *, void *),
-                                void (*mon_func)(ErtsMonitor *, void *),
-                                void (*lnk_func)(ErtsLink *, void *),
+                                ErtsMonitorFunc mon_func,
+                                ErtsLinkFunc lnk_func,
+                                void (*ext_func)(ErtsDistExternal *, void *),
                                 void *arg);
 
 extern Process *erts_dirty_process_signal_handler;
@@ -989,8 +1065,7 @@ erts_proc_sig_fetch(Process *proc)
     Sint res = 0;
     ErtsSignal *sig;
 
-    ERTS_LC_ASSERT(erts_thr_progress_is_blocking()
-                   || ERTS_PROC_IS_EXITING(proc)
+    ERTS_LC_ASSERT(ERTS_PROC_IS_EXITING(proc)
                    || ((erts_proc_lc_my_proc_locks(proc)
                         & (ERTS_PROC_LOCK_MAIN
                            | ERTS_PROC_LOCK_MSGQ))
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 2427d87f66..1c1ef1db84 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -92,10 +92,6 @@
 #undef HARDDEBUG
 #endif
 
-#ifdef HARDDEBUG
-#define HARDDEBUG_RUNQS
-#endif
-
 #ifdef HIPE
 #include "hipe_mode_switch.h"	/* for hipe_init_process() */
 #include "hipe_signal.h"	/* for hipe_thread_signal_init() */
@@ -344,6 +340,7 @@ erts_sched_stat_t erts_sched_stat;
 static erts_tsd_key_t ERTS_WRITE_UNLIKELY(sched_data_key);
 
 #if ERTS_POLL_USE_SCHEDULER_POLLING
+static erts_atomic32_t function_calls;
 static erts_atomic32_t doing_sys_schedule;
 #endif
 static erts_atomic32_t no_empty_run_queues;
@@ -738,12 +735,6 @@ erts_pre_init_process(void)
 #endif
 }
 
-static void
-release_process(void *vproc)
-{
-    erts_proc_dec_refc((Process *) vproc);
-}
-
 /* initialize the scheduler */
 void
 erts_init_process(int ncpu, int proc_tab_size, int legacy_proc_tab)
@@ -755,7 +746,7 @@ erts_init_process(int ncpu, int proc_tab_size, int legacy_proc_tab)
 
     erts_ptab_init_table(&erts_proc,
 			 ERTS_ALC_T_PROC_TABLE,
-			 release_process,
+			 NULL,
 			 (ErtsPTabElementCommon *) &erts_invalid_process.common,
 			 proc_tab_size,
 			 sizeof(Process),
@@ -1479,7 +1470,10 @@ proclist_create(Process *p)
 {
     ErtsProcList *plp = proclist_alloc();
     ensure_later_proc_interval(p->common.u.alive.started_interval);
-    plp->pid = p->common.id;
+    if (erts_atomic32_read_nob(&p->state) & ERTS_PSFLG_FREE)
+        plp->u.p = p;
+    else
+        plp->u.pid = p->common.id;
     plp->started_interval = p->common.u.alive.started_interval;
     return plp;
 }
@@ -1488,7 +1482,7 @@ static ERTS_INLINE ErtsProcList *
 proclist_copy(ErtsProcList *plp0)
 {
     ErtsProcList *plp1 = proclist_alloc();
-    plp1->pid = plp0->pid;
+    plp1->u.pid = plp0->u.pid;
     plp1->started_interval = plp0->started_interval;
     return plp1;
 }
@@ -1523,7 +1517,10 @@ erts_proclist_dump(fmtfn_t to, void *to_arg, ErtsProcList *plp)
     ErtsProcList *first = plp;
 
     while (plp) {
-        erts_print(to, to_arg, "%T", plp->pid);
+        if (is_pid(plp->u.pid))
+            erts_print(to, to_arg, "%T", plp->u.pid);
+        else
+            erts_print(to, to_arg, "%T", plp->u.p->common.id);
         plp = plp->next;
         if (plp == first)
             break;
@@ -2378,9 +2375,12 @@ struct debug_lop {
 static void later_thr_debug_wait_completed(void *vlop)
 {
     struct debug_lop *lop = vlop;
-    erts_aint32_t count = (erts_aint32_t) erts_no_schedulers;
-    count += 1; /* aux thread */
-    if (erts_atomic32_dec_read_mb(&debug_wait_completed_count) == count) {
+
+    if (erts_atomic32_dec_read_mb(&debug_wait_completed_count) == 1) {
+        erts_aint32_t count = (erts_aint32_t) erts_no_schedulers;
+        count += 1; /* aux thread */
+        erts_atomic32_set_nob(&debug_wait_completed_count, count);
+
         /* scheduler threads */
         erts_schedule_multi_misc_aux_work(0,
                                           erts_no_schedulers,
@@ -2398,19 +2398,28 @@ static void later_thr_debug_wait_completed(void *vlop)
 static void
 init_thr_debug_wait_completed(void *vproc)
 {
-    struct debug_lop* lop = erts_alloc(ERTS_ALC_T_DEBUG,
-                                       sizeof(struct debug_lop));
-    lop->proc = vproc;
-    erts_schedule_thr_prgr_later_op(later_thr_debug_wait_completed, lop, &lop->lop);
+    if (debug_wait_completed_flags == ERTS_DEBUG_WAIT_COMPLETED_AUX_WORK) {
+        if (erts_atomic32_dec_read_mb(&debug_wait_completed_count) == 1) {
+            erts_atomic32_set_nob(&debug_wait_completed_count, 0);
+            erts_resume((Process *) vproc, (ErtsProcLocks) 0);
+            erts_proc_dec_refc((Process *) vproc);
+        }
+    }
+    else {
+        struct debug_lop* lop = erts_alloc(ERTS_ALC_T_DEBUG,
+                                           sizeof(struct debug_lop));
+        lop->proc = vproc;
+        erts_schedule_thr_prgr_later_op(later_thr_debug_wait_completed, lop, &lop->lop);
+    }
 }
 
 
 int
 erts_debug_wait_completed(Process *c_p, int flags)
 {
-    /* Only one process at a time can do this */
-    erts_aint32_t count = (erts_aint32_t) (2*erts_no_schedulers);
-    count += 1; /* aux thread */
+    /* Only one process at a time can do this, +1 to mark as busy */
+    erts_aint32_t count = (erts_aint32_t) (erts_no_schedulers + 1);
+
     if (0 == erts_atomic32_cmpxchg_mb(&debug_wait_completed_count,
 				      count,
 				      0)) {
@@ -2465,6 +2474,13 @@ handle_reap_ports(ErtsAuxWorkData *awdp, erts_aint32_t aux_work, int waiting)
 
 	    erts_port_lock(prt);
 
+            if (prt->common.u.alive.reg &&
+                prt->common.u.alive.reg->name == am_heart_port) {
+                /* Leave heart port to not get killed before flushing is done*/
+                erts_port_release(prt);
+                continue;
+            }
+
 	    state = erts_atomic32_read_nob(&prt->state);
 	    if (!(state & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
 			   | ERTS_PORT_SFLG_HALT))) {
@@ -3251,6 +3267,7 @@ poll_thread(void *arg)
 static ERTS_INLINE void
 clear_sys_scheduling(void)
 {
+    erts_atomic32_set_relb(&function_calls, 0);
     erts_atomic32_set_mb(&doing_sys_schedule, 0);
 }
 
@@ -3273,31 +3290,49 @@ prepare_for_sys_schedule(void)
     return 0;
 }
 
-static void
-check_io_timer(void *null)
+#else
+#define clear_sys_scheduling()
+#define prepare_for_sys_schedule() 0
+#endif
+
+#ifdef HARDDEBUG
+#define ERTS_HDBG_CHK_SLEEP_LIST(SL, L, F, FN) \
+    check_sleepers_list((SL), (L), (F), (FN))
+static void check_sleepers_list(ErtsSchedulerSleepList *sl,
+                                int lock,
+                                ErtsSchedulerSleepInfo *find,
+                                ErtsSchedulerSleepInfo *find_not)
 {
-    ErtsSchedulerData *esdp = erts_get_scheduler_data();
-    if (prepare_for_sys_schedule()) {
-        erts_check_io(esdp->ssi->psi, ERTS_POLL_NO_TIMEOUT);
-        clear_sys_scheduling();
-    }
+    ErtsSchedulerSleepInfo *last_out;
+    int found = 0;
 
-    /* The timer is cleared if this schedulers run-queue became empty
-       or if the CHECKIO flag was cleared. The CHECKIO flags is cleared
-       when a check_balance assigns another scheduler to be the poller in
-       the overload scenario. */
-    if ((ERTS_RUNQ_FLGS_GET_NOB(esdp->run_queue) & (ERTS_RUNQ_FLG_OUT_OF_WORK|ERTS_RUNQ_FLG_CHECKIO))
-        == ERTS_RUNQ_FLG_CHECKIO) {
-        erts_start_timer_callback(ERTS_POLL_SCHEDULER_POLLING_TIMEOUT,
-                                  check_io_timer, NULL);
-    } else {
-        ERTS_RUNQ_FLGS_UNSET(esdp->run_queue, ERTS_RUNQ_FLG_CHECKIO);
-    }
-}
+    if (lock)
+        erts_spin_lock(&sl->lock);
 
+    ERTS_ASSERT(!find_not || (!find_not->next && !find_not->prev));
+    
+    last_out = sl->list;
+    if (last_out) {
+        ErtsSchedulerSleepInfo *tmp = last_out;
+        do {
+            ERTS_ASSERT(tmp->next);
+            ERTS_ASSERT(tmp->prev);
+            ERTS_ASSERT(tmp->next->prev == tmp);
+            ERTS_ASSERT(tmp->prev->next == tmp);
+            ERTS_ASSERT(tmp != find_not);
+            if (tmp == find)
+                found = !0;
+            tmp = tmp->next;
+            
+        } while (tmp != last_out);
+    }
+    ERTS_ASSERT(!find || found);
+
+    if (lock)
+        erts_spin_unlock(&sl->lock);
+}
 #else
-#define clear_sys_scheduling()
-#define prepare_for_sys_schedule() 0
+#define ERTS_HDBG_CHK_SLEEP_LIST(SL, L, F, FN) ((void) 0)
 #endif
 
 static void
@@ -3313,23 +3348,29 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 
     ERTS_LC_ASSERT(erts_lc_runq_is_locked(rq));
 
-    if (ERTS_RUNQ_IX_IS_DIRTY(rq->ix))
-	erts_spin_lock(&rq->sleepers.lock);
     flgs = sched_prep_spin_wait(ssi);
     if (flgs & ERTS_SSI_FLG_SUSPENDED) {
 	/* Go suspend instead... */
-	if (ERTS_RUNQ_IX_IS_DIRTY(rq->ix))
-	    erts_spin_unlock(&rq->sleepers.lock);
 	return;
     }
 
     if (ERTS_RUNQ_IX_IS_DIRTY(rq->ix)) {
-	ssi->prev = NULL;
-	ssi->next = rq->sleepers.list;
-	if (rq->sleepers.list)
-	    rq->sleepers.list->prev = ssi;
-	rq->sleepers.list = ssi;
-	erts_spin_unlock(&rq->sleepers.lock);
+        erts_spin_lock(&rq->sleepers.lock);
+        ERTS_HDBG_CHK_SLEEP_LIST(&rq->sleepers, 0, NULL, ssi);
+        ASSERT(!ssi->next); /* Not in sleepers list */
+        ASSERT(!ssi->prev);
+        if (!rq->sleepers.list) {
+            ssi->next = ssi->prev = ssi;
+            rq->sleepers.list = ssi;
+        }
+        else {
+            ssi->prev = rq->sleepers.list;
+            ssi->next = rq->sleepers.list->next;
+            ssi->prev->next = ssi;
+            ssi->next->prev = ssi;
+        }
+        ERTS_HDBG_CHK_SLEEP_LIST(&rq->sleepers, 0, ssi, NULL);
+        erts_spin_unlock(&rq->sleepers.lock);
         dirty_active(esdp, -1);
     }
 
@@ -3348,7 +3389,12 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
         ErtsMonotonicTime current_time = 0;
 
         aux_work = erts_atomic32_read_acqb(&ssi->aux_work);
-        if (aux_work && !ERTS_SCHEDULER_IS_DIRTY(esdp)) {
+
+        if (aux_work && ERTS_SCHEDULER_IS_DIRTY(esdp)) {
+            ERTS_INTERNAL_ERROR("Executing aux work on a dirty scheduler.");
+        }
+
+        if (aux_work) {
             if (!thr_prgr_active) {
                 erts_thr_progress_active(erts_thr_prgr_data(esdp), thr_prgr_active = 1);
                 sched_wall_time_change(esdp, 1);
@@ -3360,16 +3406,14 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
         }
 
         if (aux_work) {
-            if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
-                flgs = erts_atomic32_read_acqb(&ssi->flags);
-                current_time = erts_get_monotonic_time(esdp);
-                if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref)) {
-                    if (!thr_prgr_active) {
-                        erts_thr_progress_active(erts_thr_prgr_data(esdp), thr_prgr_active = 1);
-                        sched_wall_time_change(esdp, 1);
-                    }
-                    erts_bump_timers(esdp->timer_wheel, current_time);
+            flgs = erts_atomic32_read_acqb(&ssi->flags);
+            current_time = erts_get_monotonic_time(esdp);
+            if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref)) {
+                if (!thr_prgr_active) {
+                    erts_thr_progress_active(erts_thr_prgr_data(esdp), thr_prgr_active = 1);
+                    sched_wall_time_change(esdp, 1);
                 }
+                erts_bump_timers(esdp->timer_wheel, current_time);
             }
         }
         else {
@@ -3406,6 +3450,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
                         current_time = erts_get_monotonic_time(esdp);
                     }
                 }
+                *fcalls = 0;
                 clear_sys_scheduling();
             } else {
                 if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
@@ -3470,8 +3515,28 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
                                         (ERTS_SSI_FLG_SUSPENDED
                                          | ERTS_SSI_FLG_MSB_EXEC));
 
-    if (ERTS_SCHEDULER_IS_DIRTY(esdp))
+    if (ERTS_SCHEDULER_IS_DIRTY(esdp)) {
         dirty_sched_wall_time_change(esdp, working = 1);
+        erts_spin_lock(&rq->sleepers.lock);
+        ERTS_HDBG_CHK_SLEEP_LIST(&rq->sleepers, 0, ssi->next ? ssi : NULL, NULL);
+        if (ssi->next) { /* Still in list... */
+            if (ssi->next == ssi) {
+                ASSERT(rq->sleepers.list == ssi);
+                ASSERT(ssi->prev == ssi);
+                rq->sleepers.list = NULL;
+            }
+            else {
+                ASSERT(ssi->prev != ssi);
+                if (rq->sleepers.list == ssi)
+                    rq->sleepers.list = ssi->next;
+                ssi->prev->next = ssi->next;
+                ssi->next->prev = ssi->prev;
+            }
+            ssi->next = ssi->prev = NULL;
+        }
+        ERTS_HDBG_CHK_SLEEP_LIST(&rq->sleepers, 0, NULL, ssi);
+        erts_spin_unlock(&rq->sleepers.lock);
+    }
     else if (!thr_prgr_active) {
         erts_thr_progress_active(erts_thr_prgr_data(esdp), thr_prgr_active = 1);
         sched_wall_time_change(esdp, 1);
@@ -3559,56 +3624,44 @@ wake_scheduler(ErtsRunQueue *rq)
 }
 
 static void
-wake_dirty_schedulers(ErtsRunQueue *rq, int one)
+wake_dirty_scheduler(ErtsRunQueue *rq)
 {
-    ErtsSchedulerSleepInfo *ssi;
+    ErtsSchedulerSleepInfo *lo_ssi, *fo_ssi;
     ErtsSchedulerSleepList *sl;
 
     ASSERT(ERTS_RUNQ_IX_IS_DIRTY(rq->ix));
 
     sl = &rq->sleepers;
     erts_spin_lock(&sl->lock);
-    ssi = sl->list;
-    if (!ssi) {
+    ERTS_HDBG_CHK_SLEEP_LIST(&rq->sleepers, 0, NULL, NULL);
+    lo_ssi = sl->list;
+    if (!lo_ssi) {
 	erts_spin_unlock(&sl->lock);
-	if (one)
-	    wake_scheduler(rq);
-    } else if (one) {
+        wake_scheduler(rq);
+    }
+    else {
 	erts_aint32_t flgs;
-	if (ssi->prev)
-	    ssi->prev->next = ssi->next;
-	else {
-	    ASSERT(sl->list == ssi);
-	    sl->list = ssi->next;
+        fo_ssi = lo_ssi->next;
+        ASSERT(fo_ssi->prev == lo_ssi);
+        if (fo_ssi == lo_ssi) {
+	    ASSERT(lo_ssi->prev == lo_ssi);
+            sl->list = NULL;
+        }
+        else {
+            ASSERT(lo_ssi->prev != lo_ssi);
+	    lo_ssi->next = fo_ssi->next;
+	    fo_ssi->next->prev = fo_ssi->prev;
 	}
-	if (ssi->next)
-	    ssi->next->prev = ssi->prev;
-
-	erts_spin_unlock(&sl->lock);
-
-	ERTS_THR_MEMORY_BARRIER;
-	flgs = ssi_flags_set_wake(ssi);
-	erts_sched_finish_poke(ssi, flgs);
-    } else {
-	sl->list = NULL;
+        fo_ssi->next = fo_ssi->prev = NULL;
+        ERTS_HDBG_CHK_SLEEP_LIST(&rq->sleepers, 0, NULL, fo_ssi);
 	erts_spin_unlock(&sl->lock);
 
 	ERTS_THR_MEMORY_BARRIER;
-	do {
-	    ErtsSchedulerSleepInfo *wake_ssi = ssi;
-	    ssi = ssi->next;
-	    erts_sched_finish_poke(wake_ssi, ssi_flags_set_wake(wake_ssi));
-	} while (ssi);
+	flgs = ssi_flags_set_wake(fo_ssi);
+	erts_sched_finish_poke(fo_ssi, flgs);
     }
 }
 
-static void
-wake_dirty_scheduler(ErtsRunQueue *rq)
-{
-    wake_dirty_schedulers(rq, 1);
-}
-
-
 #define ERTS_NO_USED_RUNQS_SHIFT 16
 #define ERTS_NO_RUNQS_MASK 0xffffU
 
@@ -4103,9 +4156,7 @@ schedule_bound_processes(ErtsRunQueue *rq,
 static ERTS_INLINE void
 clear_proc_dirty_queue_bit(Process *p, ErtsRunQueue *rq, int prio_bit)
 {
-#ifdef DEBUG
     erts_aint32_t old;
-#endif
     erts_aint32_t qb = prio_bit;
     if (rq == ERTS_DIRTY_CPU_RUNQ)
 	qb <<= ERTS_PDSFLGS_IN_CPU_PRQ_MASK_OFFSET;
@@ -4113,13 +4164,8 @@ clear_proc_dirty_queue_bit(Process *p, ErtsRunQueue *rq, int prio_bit)
 	ASSERT(rq == ERTS_DIRTY_IO_RUNQ);
 	qb <<= ERTS_PDSFLGS_IN_IO_PRQ_MASK_OFFSET;
     }
-#ifdef DEBUG
-    old = (int)
-#else
-	(void)
-#endif
-	erts_atomic32_read_band_mb(&p->dirty_state, ~qb);
-    ASSERT(old & qb);
+    old = (int) erts_atomic32_read_band_mb(&p->dirty_state, ~qb);
+    ASSERT(old & qb); (void)old;
 }
 
 
@@ -4661,15 +4707,6 @@ check_balance(ErtsRunQueue *c_rq)
     if (blnc_no_rqs == 1) {
 	c_rq->check_balance_reds = INT_MAX;
 	erts_atomic32_set_nob(&balance_info.checking_balance, 0);
-#if ERTS_POLL_USE_SCHEDULER_POLLING
-	c_rq->check_balance_reds = ERTS_RUNQ_CALL_CHECK_BALANCE_REDS;
-        if ((ERTS_RUNQ_FLGS_GET_NOB(c_rq) & (ERTS_RUNQ_FLG_OUT_OF_WORK|ERTS_RUNQ_FLG_CHECKIO))
-             == 0) {
-            ERTS_RUNQ_FLGS_SET(c_rq, ERTS_RUNQ_FLG_CHECKIO);
-            erts_start_timer_callback(ERTS_POLL_SCHEDULER_POLLING_TIMEOUT, check_io_timer, NULL);
-        }
-        ERTS_RUNQ_FLGS_UNSET(c_rq, ERTS_RUNQ_FLGS_MIGRATION_INFO);
-#endif
 	return;
     }
 
@@ -5189,19 +5226,6 @@ erts_fprintf(stderr, "--------------------------------\n");
     /* Publish new migration paths... */
     erts_atomic_set_wb(&erts_migration_paths, (erts_aint_t) new_mpaths);
 
-#if ERTS_POLL_USE_SCHEDULER_POLLING
-    if (full_scheds == current_active) {
-        ERTS_ASSERT(full_scheds <= current_active);
-        /* All active schedulers ran for full, we need to do active polling,
-           so we setup a timer that does active polling */
-        if (!(ERTS_RUNQ_FLGS_GET_NOB(c_rq) & ERTS_RUNQ_FLG_CHECKIO)) {
-            /* Active polling is not running, start it */
-            erts_start_timer_callback(ERTS_POLL_SCHEDULER_POLLING_TIMEOUT, check_io_timer, NULL);
-        }
-        run_queue_info[c_rq->ix].flags |= ERTS_RUNQ_FLG_CHECKIO;
-    }
-#endif
-
     /* Reset balance statistics in all online queues */
     for (qix = 0; qix < blnc_no_rqs; qix++) {
 	Uint32 flags = run_queue_info[qix].flags;
@@ -5211,8 +5235,6 @@ erts_fprintf(stderr, "--------------------------------\n");
 	ASSERT(!(flags & ERTS_RUNQ_FLG_OUT_OF_WORK));
 	if (rq->waiting)
 	    flags |= ERTS_RUNQ_FLG_OUT_OF_WORK;
-        if (rq != c_rq)
-            flags &= ~ERTS_RUNQ_FLG_CHECKIO;
 
 	rq->full_reds_history_sum
 	    = run_queue_info[qix].full_reds_history_sum;
@@ -5222,7 +5244,7 @@ erts_fprintf(stderr, "--------------------------------\n");
 	ERTS_DBG_CHK_FULL_REDS_HISTORY(rq);
 
 	rq->out_of_work_count = 0;
-	(void) ERTS_RUNQ_FLGS_READ_BSET(rq, ERTS_RUNQ_FLGS_MIGRATION_INFO|ERTS_RUNQ_FLG_CHECKIO, flags);
+	(void) ERTS_RUNQ_FLGS_READ_BSET(rq, ERTS_RUNQ_FLGS_MIGRATION_INFO, flags);
 	rq->max_len = erts_atomic32_read_dirty(&rq->len);
 	for (pix = 0; pix < ERTS_NO_PRIO_LEVELS; pix++) {
 	    ErtsRunQueueInfo *rqi;
@@ -5873,6 +5895,7 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online, int no_poll_th
 	erts_alloc_permanent_cache_aligned(ERTS_ALC_T_RUNQS, size_runqs);
 #if ERTS_POLL_USE_SCHEDULER_POLLING
     erts_atomic32_init_nob(&doing_sys_schedule, 0);
+    erts_atomic32_init_nob(&function_calls, 0);
 #endif
     erts_atomic32_init_nob(&no_empty_run_queues, 0);
 
@@ -5988,6 +6011,8 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online, int no_poll_th
     for (ix = 0; ix < no_dirty_cpu_schedulers; ix++) {
 	ErtsSchedulerSleepInfo *ssi = &aligned_dirty_cpu_sched_sleep_info[ix].ssi;
 	erts_atomic32_init_nob(&ssi->flags, 0);
+        ssi->next = NULL;
+        ssi->prev = NULL;
 	ssi->event = NULL; /* initialized in sched_dirty_cpu_thread_func */
 	erts_atomic32_init_nob(&ssi->aux_work, 0);
     }
@@ -5998,6 +6023,8 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online, int no_poll_th
     for (ix = 0; ix < no_dirty_io_schedulers; ix++) {
 	ErtsSchedulerSleepInfo *ssi = &aligned_dirty_io_sched_sleep_info[ix].ssi;
 	erts_atomic32_init_nob(&ssi->flags, 0);
+        ssi->next = NULL;
+        ssi->prev = NULL;
 	ssi->event = NULL; /* initialized in sched_dirty_io_thread_func */
 	erts_atomic32_init_nob(&ssi->aux_work, 0);
     }
@@ -6511,8 +6538,7 @@ schedule_out_process(ErtsRunQueue *c_rq, erts_aint32_t state, Process *p,
 
 	n &= ~running_flgs;
 	if ((!!(a & (ERTS_PSFLG_ACTIVE_SYS|ERTS_PSFLG_DIRTY_ACTIVE_SYS))
-	    | ((a & (ERTS_PSFLG_ACTIVE|ERTS_PSFLG_SUSPENDED)) == ERTS_PSFLG_ACTIVE))
-            & !(a & ERTS_PSFLG_FREE)) {
+	    | ((a & (ERTS_PSFLG_ACTIVE|ERTS_PSFLG_SUSPENDED)) == ERTS_PSFLG_ACTIVE))) {
 	    enqueue = check_enqueue_in_prio_queue(p, &enq_prio, &n, a);
 	}
 	a = erts_atomic32_cmpxchg_mb(&p->state, n, e);
@@ -6547,7 +6573,6 @@ schedule_out_process(ErtsRunQueue *c_rq, erts_aint32_t state, Process *p,
     else {
 	Process* sched_p;
 
-        ASSERT(!(n & ERTS_PSFLG_FREE));
 	ASSERT(!(n & ERTS_PSFLG_SUSPENDED) || (n & (ERTS_PSFLG_ACTIVE_SYS
 						    | ERTS_PSFLG_DIRTY_ACTIVE_SYS)));
 
@@ -6677,8 +6702,8 @@ change_proc_schedule_state(Process *p,
 
 	enqueue = ERTS_ENQUEUE_NOT;
 
-	if (a & ERTS_PSFLG_FREE)
-	    break; /* We don't want to schedule free processes... */
+        if ((a & (ERTS_PSFLG_FREE|ERTS_PSFLG_ACTIVE)) == ERTS_PSFLG_FREE)
+            break; /* If free and not active, do not schedule */
 
 	if (clear_state_flags)
 	    n &= ~clear_state_flags;
@@ -7204,8 +7229,7 @@ schdlr_sspnd_resume_procs(ErtsSchedType sched_type,
     while (resume->msb.chngrs) {
 	ErtsProcList *plp = resume->msb.chngrs;
 	resume->msb.chngrs = plp->next;
-	schdlr_sspnd_resume_proc(sched_type,
-                                 plp->pid);
+	schdlr_sspnd_resume_proc(sched_type, plp->u.pid);
 	proclist_destroy(plp);
     }
 }
@@ -7281,9 +7305,7 @@ msb_scheduler_type_switch(ErtsSchedType sched_type,
     Uint32 nrml_prio, dcpu_prio, dio_prio;
     ErtsSchedType exec_type;
     ErtsRunQueue *exec_rq;
-#ifdef DEBUG
     erts_aint32_t dbg_val;
-#endif
 
     ASSERT(schdlr_sspnd.msb.ongoing);
 
@@ -7398,16 +7420,12 @@ msb_scheduler_type_switch(ErtsSchedType sched_type,
      * Suspend this scheduler and wake up scheduler
      * number one of another type...
      */
-#ifdef DEBUG
     dbg_val =
-#else
-    (void)
-#endif
         erts_atomic32_read_bset_mb(&esdp->ssi->flags,
                                        (ERTS_SSI_FLG_SUSPENDED
                                         | ERTS_SSI_FLG_MSB_EXEC),
                                        ERTS_SSI_FLG_SUSPENDED);
-    ASSERT(dbg_val & ERTS_SSI_FLG_MSB_EXEC);
+    ASSERT(dbg_val & ERTS_SSI_FLG_MSB_EXEC); (void)dbg_val;
 
     switch (exec_type) {
     case ERTS_SCHED_NORMAL:
@@ -7425,11 +7443,7 @@ msb_scheduler_type_switch(ErtsSchedType sched_type,
         break;
     }
 
-#ifdef DEBUG
     dbg_val =
-#else
-    (void)
-#endif
         erts_atomic32_read_bset_mb(&exec_rq->scheduler->ssi->flags,
                                        (ERTS_SSI_FLG_SUSPENDED
                                         | ERTS_SSI_FLG_MSB_EXEC),
@@ -7517,7 +7531,13 @@ suspend_scheduler(ErtsSchedulerData *esdp)
         return;
     }
 
+#ifdef HARDDEBUG
+    if (sched_type != ERTS_SCHED_NORMAL)
+        ERTS_HDBG_CHK_SLEEP_LIST(&esdp->run_queue->sleepers, !0, NULL, ssi);
+#endif
+
     if (erts_atomic32_read_nob(&ssi->flags) & ERTS_SSI_FLG_MSB_EXEC) {
+
         ASSERT(no == 1);
         if (!msb_scheduler_type_switch(sched_type, esdp, no))
             return;
@@ -7641,7 +7661,7 @@ suspend_scheduler(ErtsSchedulerData *esdp)
 			else {
 			    schdlr_sspnd.changer = am_true; /* change right in transit */
 			    /* resume process that is queued for next change... */
-			    resume.onln.nxt = plp->pid;
+			    resume.onln.nxt = plp->u.pid;
 			    ASSERT(is_internal_pid(resume.onln.nxt));
 			}
 		    }
@@ -7861,7 +7881,7 @@ abort_sched_onln_chng_waitq(Process *p)
 		proclist_destroy(plp);
 		plp = erts_proclist_peek_first(schdlr_sspnd.chngq);
 		if (plp)
-		    resume = plp->pid;
+		    resume = plp->u.pid;
 		else
 		    schdlr_sspnd.changer = am_false;
 	    }
@@ -8127,7 +8147,8 @@ done:
 ErtsSchedSuspendResult
 erts_block_multi_scheduling(Process *p, ErtsProcLocks plocks, int on, int normal, int all)
 {
-    int resume_proc, ix, res, have_unlocked_plocks = 0;
+    ErtsSchedSuspendResult res;
+    int resume_proc, ix, have_unlocked_plocks = 0;
     ErtsProcList *plp;
     ErtsMultiSchedulingBlock *msbp;
     erts_aint32_t chng_flg;
@@ -8360,10 +8381,10 @@ erts_multi_scheduling_blockers(Process *p, int normal)
 	     plp1;
 	     plp1 = erts_proclist_peek_next(msbp->blckrs, plp1)) {
 	    for (plp2 = erts_proclist_peek_first(msbp->blckrs);
-		 plp2->pid != plp1->pid;
+		 plp2->u.pid != plp1->u.pid;
 		 plp2 = erts_proclist_peek_next(msbp->blckrs, plp2));
 	    if (plp2 == plp1) {
-		res = CONS(hp, plp1->pid, res);
+		res = CONS(hp, plp1->u.pid, res);
 		hp += 2;
 	    }
 	    /* else: already in result list */
@@ -8547,9 +8568,6 @@ erts_start_schedulers(void)
 {
     ethr_tid tid;
     int res = 0;
-    Uint actual;
-    Uint wanted = erts_no_schedulers;
-    Uint wanted_no_schedulers = erts_no_schedulers;
     char name[16];
     ethr_thr_opts opts = ETHR_THR_OPTS_DEFAULT_INITER;
     int ix;
@@ -8563,40 +8581,34 @@ erts_start_schedulers(void)
         erts_snprintf(opts.name, 16, "runq_supervisor");
 	erts_atomic_init_nob(&runq_supervisor_sleeping, 0);
 	if (0 != ethr_event_init(&runq_supervision_event))
-	    erts_exit(ERTS_ERROR_EXIT, "Failed to create run-queue supervision event\n");
+	    erts_exit(ERTS_ABORT_EXIT, "Failed to create run-queue supervision event\n");
         res = ethr_thr_create(&runq_supervisor_tid,
                               runq_supervisor,
                               NULL,
                               &opts);
 	if (0 != res)
-	    erts_exit(ERTS_ERROR_EXIT, "Failed to create run-queue supervision thread, "
+	    erts_exit(ERTS_ABORT_EXIT, "Failed to create run-queue supervision thread, "
                       "error = %d\n", res);
 
     }
 
     opts.suggested_stack_size = erts_sched_thread_suggested_stack_size;
 
-    if (wanted < 1)
-	wanted = 1;
-    if (wanted > ERTS_MAX_NO_OF_SCHEDULERS) {
-	wanted = ERTS_MAX_NO_OF_SCHEDULERS;
-	res = ENOTSUP;
-    }
-
-    for (actual = 0; actual < wanted; actual++) {
-	ErtsSchedulerData *esdp = ERTS_SCHEDULER_IX(actual);
-
-	ASSERT(actual == esdp->no - 1);
-
-	erts_snprintf(opts.name, 16, "%lu_scheduler", actual + 1);
+    ASSERT(erts_no_schedulers > 0 && erts_no_schedulers <= ERTS_MAX_NO_OF_SCHEDULERS);
 
+    for (ix = 0; ix < erts_no_schedulers; ix++) {
+	ErtsSchedulerData *esdp = ERTS_SCHEDULER_IX(ix);
+	ASSERT(ix == esdp->no - 1);
+	erts_snprintf(opts.name, 16, "%lu_scheduler", ix + 1);
 	res = ethr_thr_create(&esdp->tid, sched_thread_func, (void*)esdp, &opts);
-
 	if (res != 0) {
-           break;
+           erts_exit(ERTS_ABORT_EXIT, "Failed to create scheduler thread %d, error = %d\n", ix, res);
 	}
     }
-    erts_no_schedulers = actual;
+
+    /* Probably not needed as thread create will imply a memory barrier,
+       but we do one just to be safe. */
+    ERTS_THR_MEMORY_BARRIER;
 
     {
 	for (ix = 0; ix < erts_no_dirty_cpu_schedulers; ix++) {
@@ -8605,7 +8617,7 @@ erts_start_schedulers(void)
             opts.suggested_stack_size = erts_dcpu_sched_thread_suggested_stack_size;
 	    res = ethr_thr_create(&esdp->tid,sched_dirty_cpu_thread_func,(void*)esdp,&opts);
 	    if (res != 0)
-		erts_exit(ERTS_ERROR_EXIT, "Failed to create dirty cpu scheduler thread %d, error = %d\n", ix, res);
+		erts_exit(ERTS_ABORT_EXIT, "Failed to create dirty cpu scheduler thread %d, error = %d\n", ix, res);
 	}
 	for (ix = 0; ix < erts_no_dirty_io_schedulers; ix++) {
 	    ErtsSchedulerData *esdp = ERTS_DIRTY_IO_SCHEDULER_IX(ix);
@@ -8613,40 +8625,22 @@ erts_start_schedulers(void)
             opts.suggested_stack_size = erts_dio_sched_thread_suggested_stack_size;
 	    res = ethr_thr_create(&esdp->tid,sched_dirty_io_thread_func,(void*)esdp,&opts);
 	    if (res != 0)
-		erts_exit(ERTS_ERROR_EXIT, "Failed to create dirty io scheduler thread %d, error = %d\n", ix, res);
+		erts_exit(ERTS_ABORT_EXIT, "Failed to create dirty io scheduler thread %d, error = %d\n", ix, res);
 	}
     }
 
-    ERTS_THR_MEMORY_BARRIER;
-
     erts_snprintf(opts.name, 16, "aux");
 
     res = ethr_thr_create(&tid, aux_thread, NULL, &opts);
     if (res != 0)
-	erts_exit(ERTS_ERROR_EXIT, "Failed to create aux thread, error = %d\n", res);
+	erts_exit(ERTS_ABORT_EXIT, "Failed to create aux thread, error = %d\n", res);
 
     for (ix = 0; ix < erts_no_poll_threads; ix++) {
         erts_snprintf(opts.name, 16, "%d_poller", ix);
 
         res = ethr_thr_create(&tid, poll_thread, (void*)(UWord)ix, &opts);
         if (res != 0)
-            erts_exit(ERTS_ERROR_EXIT, "Failed to create poll thread\n");
-    }
-
-    if (actual < 1)
-	erts_exit(ERTS_ERROR_EXIT,
-		 "Failed to create any scheduler-threads: %s (%d)\n",
-		 erl_errno_id(res),
-		 res);
-    if (res != 0) {
-	erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
-	ASSERT(actual != wanted_no_schedulers);
-	erts_dsprintf(dsbufp,
-		      "Failed to create %beu scheduler-threads (%s:%d); "
-		      "only %beu scheduler-thread%s created.\n",
-		      wanted_no_schedulers, erl_errno_id(res), res,
-		      actual, actual == 1 ? " was" : "s were");
-	erts_send_error_to_logger_nogl(dsbufp);
+            erts_exit(ERTS_ABORT_EXIT, "Failed to create poll thread\n");
     }
 }
 
@@ -9000,11 +8994,8 @@ erts_suspend(Process* c_p, ErtsProcLocks c_p_locks, Port *busy_port)
 	suspend = 1;
 
     if (suspend) {
-#ifdef DEBUG
-	int res =
-#endif
-	    suspend_process(c_p, c_p);
-	ASSERT(res);
+	int res = suspend_process(c_p, c_p);
+	ASSERT(res); (void)res;
     }
 
     if (!(c_p_locks & ERTS_PROC_LOCK_STATUS))
@@ -9035,8 +9026,13 @@ erts_resume_processes(ErtsProcList *list)
     while (plp) {
 	Process *proc;
 	ErtsProcList *fplp;
-	ASSERT(is_internal_pid(plp->pid));
-	proc = erts_pid2proc(NULL, 0, plp->pid, ERTS_PROC_LOCK_STATUS);
+	ASSERT(is_internal_pid(plp->u.pid) || is_CP((Eterm)plp->u.p));
+        if (is_internal_pid(plp->u.pid))
+            proc = erts_pid2proc(NULL, 0, plp->u.pid, ERTS_PROC_LOCK_STATUS);
+        else {
+            proc = plp->u.p;
+            erts_proc_lock(proc, ERTS_PROC_LOCK_STATUS);
+        }
 	if (proc) {
 	    if (erts_proclist_same(plp, proc)) {
 		resume_process(proc, ERTS_PROC_LOCK_STATUS);
@@ -9217,7 +9213,7 @@ Process *erts_schedule(ErtsSchedulerData *esdp, Process *p, int calls)
     Process *proxy_p = NULL;
     ErtsRunQueue *rq;
     int context_reds;
-    int fcalls;
+    int fcalls = 0;
     int actual_reds;
     int reds;
     Uint32 flags;
@@ -9291,6 +9287,10 @@ Process *erts_schedule(ErtsSchedulerData *esdp, Process *p, int calls)
 	    reds = ERTS_PROC_MIN_CONTEXT_SWITCH_REDS_COST;
 	esdp->virtual_reds = 0;
 
+#if ERTS_POLL_USE_SCHEDULER_POLLING
+        fcalls = (int) erts_atomic32_add_read_acqb(&function_calls, reds);
+#endif
+
 	ASSERT(esdp && esdp == erts_get_scheduler_data());
 
 	rq = erts_get_runq_current(esdp);
@@ -9445,6 +9445,7 @@ Process *erts_schedule(ErtsSchedulerData *esdp, Process *p, int calls)
 
 	if (!is_normal_sched & !!(flags & ERTS_RUNQ_FLG_HALTING)) {
 	    /* Wait for emulator to terminate... */
+	    erts_runq_unlock(rq);
 	    while (1)
 		erts_milli_sleep(1000*1000);
 	}
@@ -9507,7 +9508,33 @@ Process *erts_schedule(ErtsSchedulerData *esdp, Process *p, int calls)
 	    non_empty_runq(rq);
 
 	    goto check_activities_to_run;
-	}
+	} else if (is_normal_sched &&
+                   fcalls > (2 * context_reds) &&
+                   prepare_for_sys_schedule()) {
+            ErtsMonotonicTime current_time;
+	    /*
+	     * Schedule system-level activities.
+	     */
+
+	    ERTS_MSACC_PUSH_STATE_CACHED_M();
+
+	    erts_runq_unlock(rq);
+
+            ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_CHECK_IO);
+            LTTNG2(scheduler_poll, esdp->no, 1);
+
+	    erts_check_io(esdp->ssi->psi, ERTS_POLL_NO_TIMEOUT);
+	    ERTS_MSACC_POP_STATE_M();
+
+	    current_time = erts_get_monotonic_time(esdp);
+	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
+		erts_bump_timers(esdp->timer_wheel, current_time);
+
+	    erts_runq_lock(rq);
+	    fcalls = 0;
+	    clear_sys_scheduling();
+	    goto continue_check_activities_to_run;
+        }
 
         if (flags & ERTS_RUNQ_FLG_MISC_OP)
 	    exec_misc_ops(rq);
@@ -9598,7 +9625,8 @@ Process *erts_schedule(ErtsSchedulerData *esdp, Process *p, int calls)
 
 	    while (1) {
 		erts_aint32_t exp, new;
-		int run_process;
+		int run_process, not_running, exiting_on_normal_sched,
+                    not_suspended, not_exiting_on_dirty_sched;
 		new = exp = state;
 		new &= psflg_band_mask;
 		/*
@@ -9607,29 +9635,33 @@ Process *erts_schedule(ErtsSchedulerData *esdp, Process *p, int calls)
 		 * scheduler, and not suspended (and not in a
 		 * state where suspend should be ignored).
 		 */
-		run_process = (((!(state & (ERTS_PSFLG_RUNNING
-					    | ERTS_PSFLG_RUNNING_SYS
-					    | ERTS_PSFLG_DIRTY_RUNNING
-					    | ERTS_PSFLG_DIRTY_RUNNING_SYS
-					    | ERTS_PSFLG_FREE)))
-				| (((state & (ERTS_PSFLG_RUNNING
-
-					      | ERTS_PSFLG_FREE
-					      | ERTS_PSFLG_RUNNING_SYS
-					      | ERTS_PSFLG_DIRTY_RUNNING_SYS
-					      | ERTS_PSFLG_EXITING))
-				    == ERTS_PSFLG_EXITING)
-				   & (!!is_normal_sched))
-				   )
-			       & ((state & (ERTS_PSFLG_SUSPENDED
-					    | ERTS_PSFLG_EXITING
-					    | ERTS_PSFLG_FREE
-					    | ERTS_PSFLG_ACTIVE_SYS
-					    | ERTS_PSFLG_DIRTY_ACTIVE_SYS))
-				  != ERTS_PSFLG_SUSPENDED)
-                               & (!(state & ERTS_PSFLG_EXITING)
-                                  | (!!is_normal_sched))
-                    );
+                not_running = !(state & (ERTS_PSFLG_RUNNING
+                                         | ERTS_PSFLG_RUNNING_SYS
+                                         | ERTS_PSFLG_DIRTY_RUNNING
+                                         | ERTS_PSFLG_DIRTY_RUNNING_SYS
+                                         | ERTS_PSFLG_FREE));
+                exiting_on_normal_sched =
+                    ((state & (ERTS_PSFLG_RUNNING
+                               | ERTS_PSFLG_ACTIVE
+                               | ERTS_PSFLG_RUNNING_SYS
+                               | ERTS_PSFLG_DIRTY_RUNNING_SYS
+                               | ERTS_PSFLG_EXITING))
+                     == (ERTS_PSFLG_EXITING|ERTS_PSFLG_ACTIVE))
+                    & (!!is_normal_sched);
+
+
+                not_suspended = ((state & (ERTS_PSFLG_SUSPENDED
+                                           | ERTS_PSFLG_EXITING
+                                           | ERTS_PSFLG_FREE
+                                           | ERTS_PSFLG_ACTIVE_SYS
+                                           | ERTS_PSFLG_DIRTY_ACTIVE_SYS))
+                                 != ERTS_PSFLG_SUSPENDED);
+
+                not_exiting_on_dirty_sched = !(state & ERTS_PSFLG_EXITING) | (!!is_normal_sched);
+
+		run_process = (not_running | exiting_on_normal_sched)
+                    & not_suspended
+                    & not_exiting_on_dirty_sched;
 
 		if (run_process) {
 		    if (state & (ERTS_PSFLG_ACTIVE_SYS
@@ -9920,7 +9952,7 @@ trace_schedule_in(Process *p, erts_aint32_t state)
     /* Clear tracer if it has been removed */
     if (erts_is_tracer_proc_enabled(p, ERTS_PROC_LOCK_MAIN, &p->common)) {
 
-        if (state & ERTS_PSFLG_EXITING) {
+        if (state & ERTS_PSFLG_EXITING && p->u.terminate) {
             if (ARE_TRACE_FLAGS_ON(p, F_TRACE_SCHED_EXIT))
                 trace_sched(p, ERTS_PROC_LOCK_MAIN, am_in_exiting);
         }
@@ -9944,12 +9976,9 @@ trace_schedule_out(Process *p, erts_aint32_t state)
     if (IS_TRACED_FL(p, F_TRACE_CALLS) && !(state & ERTS_PSFLG_FREE))
         erts_schedule_time_break(p, ERTS_BP_CALL_TIME_SCHEDULE_OUT);
 
-    if ((state & (ERTS_PSFLG_FREE|ERTS_PSFLG_EXITING)) == ERTS_PSFLG_EXITING) {
+    if (state & ERTS_PSFLG_EXITING && p->u.terminate) {
         if (ARE_TRACE_FLAGS_ON(p, F_TRACE_SCHED_EXIT))
-            trace_sched(p, ERTS_PROC_LOCK_MAIN,
-                        ((state & ERTS_PSFLG_FREE)
-                         ? am_out_exited
-                         : am_out_exiting));
+            trace_sched(p, ERTS_PROC_LOCK_MAIN, am_out_exiting);
     }
     else {
         if (ARE_TRACE_FLAGS_ON(p, F_TRACE_SCHED) ||
@@ -12024,12 +12053,103 @@ erts_set_self_exiting(Process *c_p, Eterm reason)
         add2runq(enqueue, enq_prio, c_p, state, NULL);
 }
 
-void
-erts_proc_exit_handle_monitor(ErtsMonitor *mon, void *vctxt)
+static int
+erts_proc_exit_handle_dist_monitor(ErtsMonitor *mon, void *vctxt, Sint reds)
+{
+    ErtsProcExitContext *ctxt = (ErtsProcExitContext *) vctxt;
+    Process *c_p = ctxt->c_p;
+    Eterm reason = ctxt->reason;
+    int code;
+    ErtsDSigSendContext ctx;
+    ErtsMonLnkDist *dist;
+    DistEntry *dep;
+    Eterm watcher, ref, *hp;
+    ErtsMonitorData *mdp = NULL;
+    Eterm watched;
+    Uint watcher_sz, ref_sz;
+    ErtsHeapFactory factory;
+    Sint reds_consumed = 0;
+
+    ASSERT(c_p->flags & F_DISABLE_GC);
+    ASSERT(erts_monitor_is_target(mon) && mon->type == ERTS_MON_TYPE_DIST_PROC);
+
+    mdp = erts_monitor_to_data(mon);
+
+    if (mon->flags & ERTS_ML_FLG_NAME)
+        watched = ((ErtsMonitorDataExtended *) mdp)->u.name;
+    else
+        watched = c_p->common.id;
+    ASSERT(is_internal_pid(watched) || is_atom(watched));
+
+    watcher = mon->other.item;
+    ASSERT(is_external_pid(watcher));
+    dep = external_pid_dist_entry(watcher);
+    ASSERT(dep);
+    dist = ((ErtsMonitorDataExtended *) mdp)->dist;
+    ASSERT(dist);
+
+    code = erts_dsig_prepare(&ctx, dep, c_p, ERTS_PROC_LOCK_MAIN,
+                             ERTS_DSP_NO_LOCK, 0, 0, 1);
+
+    ctx.reds = (Sint) (reds * TERM_TO_BINARY_LOOP_FACTOR);
+
+    switch (code) {
+    case ERTS_DSIG_PREP_NOT_ALIVE:
+    case ERTS_DSIG_PREP_NOT_CONNECTED:
+        break;
+    case ERTS_DSIG_PREP_PENDING:
+    case ERTS_DSIG_PREP_CONNECTED:
+        if (dist->connection_id != ctx.connection_id)
+            break;
+        erts_factory_proc_init(&factory, c_p);
+        watcher_sz = size_object(watcher);
+        hp = erts_produce_heap(&factory, watcher_sz, 0);
+        watcher = copy_struct(watcher, watcher_sz, &hp, factory.off_heap);
+        ref_sz = size_object(mdp->ref);
+        hp = erts_produce_heap(&factory, ref_sz, 0);
+        ref = copy_struct(mdp->ref, ref_sz, &hp, factory.off_heap);
+        erts_factory_close(&factory);
+        code = erts_dsig_send_m_exit(&ctx,
+                                     watcher,
+                                     watched,
+                                     ref,
+                                     reason);
+        reds_consumed = reds - (ctx.reds / TERM_TO_BINARY_LOOP_FACTOR);
+        switch (code) {
+        case ERTS_DSIG_SEND_CONTINUE:
+        case ERTS_DSIG_SEND_YIELD:
+            ctxt->dist_state = erts_dsend_export_trap_context(c_p, &ctx);
+            reds_consumed = reds; /* force yield */
+            break;
+        case ERTS_DSIG_SEND_OK:
+            break;
+        case ERTS_DSIG_SEND_TOO_LRG:
+            erts_kill_dist_connection(dep, dist->connection_id);
+            break;
+        default:
+            ASSERT(! "Invalid dsig send exit monitor result");
+            break;
+        }
+        break;
+    default:
+        ASSERT(! "Invalid dsig prep exit monitor result");
+        break;
+    }
+    if (!erts_monitor_dist_delete(&mdp->origin))
+        erts_monitor_release(mon);
+    else
+        erts_monitor_release_both(mdp);
+    return reds_consumed;
+}
+
+int
+erts_proc_exit_handle_monitor(ErtsMonitor *mon, void *vctxt, Sint reds)
 {
-    Process *c_p = ((ErtsProcExitContext *) vctxt)->c_p;
-    Eterm reason = ((ErtsProcExitContext *) vctxt)->reason;
+    ErtsProcExitContext *ctxt = (ErtsProcExitContext *) vctxt;
+    Process *c_p = ctxt->c_p;
+    Eterm reason = ctxt->reason;
     ErtsMonitorData *mdp = NULL;
+    int res = 1;
 
     if (erts_monitor_is_target(mon)) {
         /* We are being watched... */
@@ -12059,43 +12179,48 @@ erts_proc_exit_handle_monitor(ErtsMonitor *mon, void *vctxt)
         case ERTS_MON_TYPE_DIST_PROC: {
             ErtsMonLnkDist *dist;
             DistEntry *dep;
-            ErtsDSigData dsd;
+            ErtsDSigSendContext ctx;
             int code;
             Eterm watcher;
             Eterm watched;
 
-            mdp = erts_monitor_to_data(mon);
-
-            if (mon->flags & ERTS_ML_FLG_NAME)
-                watched = ((ErtsMonitorDataExtended *) mdp)->u.name;
-            else
-                watched = c_p->common.id;
-            ASSERT(is_internal_pid(watched) || is_atom(watched));
+            if (is_immed(reason)) {
+                mdp = erts_monitor_to_data(mon);
 
-            watcher = mon->other.item;
-	    ASSERT(is_external_pid(watcher));    
-	    dep = external_pid_dist_entry(watcher);
-            ASSERT(dep);
-            dist = ((ErtsMonitorDataExtended *) mdp)->dist;
-            ASSERT(dist);
-            code = erts_dsig_prepare(&dsd, dep, NULL, 0,
-                                     ERTS_DSP_NO_LOCK, 0, 0);
-            switch (code) {
-            case ERTS_DSIG_PREP_CONNECTED:
-            case ERTS_DSIG_PREP_PENDING:
-                if (dist->connection_id == dsd.connection_id) {
-                    code = erts_dsig_send_m_exit(&dsd,
-                                                 watcher,
-                                                 watched,
-                                                 mdp->ref,
-                                                 reason);
-                    ASSERT(code == ERTS_DSIG_SEND_OK);
+                if (mon->flags & ERTS_ML_FLG_NAME)
+                    watched = ((ErtsMonitorDataExtended *) mdp)->u.name;
+                else
+                    watched = c_p->common.id;
+                ASSERT(is_internal_pid(watched) || is_atom(watched));
+
+                watcher = mon->other.item;
+                ASSERT(is_external_pid(watcher));
+                dep = external_pid_dist_entry(watcher);
+                ASSERT(dep);
+                dist = ((ErtsMonitorDataExtended *) mdp)->dist;
+                ASSERT(dist);
+                code = erts_dsig_prepare(&ctx, dep, NULL, 0,
+                                         ERTS_DSP_NO_LOCK, 1, 1, 0);
+                switch (code) {
+                case ERTS_DSIG_PREP_CONNECTED:
+                case ERTS_DSIG_PREP_PENDING:
+                    if (dist->connection_id == ctx.connection_id) {
+                        code = erts_dsig_send_m_exit(&ctx,
+                                                     watcher,
+                                                     watched,
+                                                     mdp->ref,
+                                                     reason);
+                        ASSERT(code == ERTS_DSIG_SEND_OK);
+                    }
+                default:
+                    break;
                 }
-            default:
-                break;
+                if (!erts_monitor_dist_delete(&mdp->origin))
+                    mdp = NULL;
+            } else {
+                erts_monitor_tree_insert(&ctxt->dist_monitors, mon);
+                return 1;
             }
-            if (!erts_monitor_dist_delete(&mdp->origin))
-                mdp = NULL;
             break;
         }
         default:
@@ -12137,7 +12262,7 @@ erts_proc_exit_handle_monitor(ErtsMonitor *mon, void *vctxt)
         case ERTS_MON_TYPE_DIST_PROC: {
             ErtsMonLnkDist *dist;
             DistEntry *dep;
-            ErtsDSigData dsd;
+            ErtsDSigSendContext ctx;
             int code;
             Eterm watched;
 
@@ -12154,17 +12279,16 @@ erts_proc_exit_handle_monitor(ErtsMonitor *mon, void *vctxt)
                 ASSERT(is_external_pid(watched));
 		dep = external_pid_dist_entry(watched);
             }
-            code = erts_dsig_prepare(&dsd, dep, NULL, 0,
-                                     ERTS_DSP_NO_LOCK, 0, 0);
+            code = erts_dsig_prepare(&ctx, dep, NULL, 0,
+                                     ERTS_DSP_NO_LOCK, 1, 1, 0);
             switch (code) {
             case ERTS_DSIG_PREP_CONNECTED:
             case ERTS_DSIG_PREP_PENDING:
-                if (dist->connection_id == dsd.connection_id) {
-                    code = erts_dsig_send_demonitor(&dsd,
+                if (dist->connection_id == ctx.connection_id) {
+                    code = erts_dsig_send_demonitor(&ctx,
                                                     c_p->common.id,
                                                     watched,
-                                                    mdp->ref,
-                                                    1);
+                                                    mdp->ref);
                     ASSERT(code == ERTS_DSIG_SEND_OK);
                 }
             default:
@@ -12172,6 +12296,7 @@ erts_proc_exit_handle_monitor(ErtsMonitor *mon, void *vctxt)
             }
             if (!erts_monitor_dist_delete(&mdp->target))
                 mdp = NULL;
+            res = 100;
             break;
         }
         default:
@@ -12184,11 +12309,93 @@ erts_proc_exit_handle_monitor(ErtsMonitor *mon, void *vctxt)
         erts_monitor_release_both(mdp);
     else if (mon)
         erts_monitor_release(mon);
+    return res;
 }
 
-void
-erts_proc_exit_handle_link(ErtsLink *lnk, void *vctxt)
+static int
+erts_proc_exit_handle_dist_link(ErtsLink *lnk, void *vctxt, Sint reds)
+{
+    ErtsProcExitContext *ctxt = (ErtsProcExitContext *) vctxt;
+    Process *c_p = ctxt->c_p;
+    Eterm reason = ctxt->reason, item, *hp;
+    Uint item_sz;
+    int code;
+    ErtsDSigSendContext ctx;
+    ErtsMonLnkDist *dist;
+    DistEntry *dep;
+    ErtsLink *dlnk;
+    ErtsLinkData *ldp = NULL;
+    ErtsHeapFactory factory;
+    Sint reds_consumed = 0;
+
+    ASSERT(c_p->flags & F_DISABLE_GC);
+    ASSERT(lnk->type == ERTS_LNK_TYPE_DIST_PROC);
+    dlnk = erts_link_to_other(lnk, &ldp);
+    dist = ((ErtsLinkDataExtended *) ldp)->dist;
+
+    ASSERT(is_external_pid(lnk->other.item));
+    dep = external_pid_dist_entry(lnk->other.item);
+
+    ASSERT(dep != erts_this_dist_entry);
+
+    if (!erts_link_dist_delete(dlnk))
+        ldp = NULL;
+
+    code = erts_dsig_prepare(&ctx, dep, c_p, ERTS_PROC_LOCK_MAIN,
+                             ERTS_DSP_NO_LOCK, 0, 0, 0);
+
+    ctx.reds = (Sint) (reds * TERM_TO_BINARY_LOOP_FACTOR);
+
+    switch (code) {
+    case ERTS_DSIG_PREP_NOT_ALIVE:
+    case ERTS_DSIG_PREP_NOT_CONNECTED:
+        break;
+    case ERTS_DSIG_PREP_PENDING:
+    case ERTS_DSIG_PREP_CONNECTED:
+        if (dist->connection_id != ctx.connection_id)
+            break;
+        erts_factory_proc_init(&factory, c_p);
+        item_sz = size_object(lnk->other.item);
+        hp = erts_produce_heap(&factory, item_sz, 0);
+        item = copy_struct(lnk->other.item, item_sz, &hp, factory.off_heap);
+        erts_factory_close(&factory);
+        code = erts_dsig_send_exit_tt(&ctx,
+                                      c_p->common.id,
+                                      item,
+                                      reason,
+                                      SEQ_TRACE_TOKEN(c_p));
+        reds_consumed = reds - (ctx.reds / TERM_TO_BINARY_LOOP_FACTOR);
+        switch (code) {
+        case ERTS_DSIG_SEND_YIELD:
+        case ERTS_DSIG_SEND_CONTINUE:
+            ctxt->dist_state = erts_dsend_export_trap_context(c_p, &ctx);
+            reds_consumed = reds; /* force yield */
+            break;
+        case ERTS_DSIG_SEND_OK:
+            break;
+        case ERTS_DSIG_SEND_TOO_LRG:
+            erts_kill_dist_connection(dep, dist->connection_id);
+            break;
+        default:
+            ASSERT(! "Invalid dsig send exit monitor result");
+            break;
+        }
+        break;
+    default:
+        ASSERT(! "Invalid dsig prep exit monitor result");
+        break;
+    }
+    if (ldp)
+        erts_link_release_both(ldp);
+    else if (lnk)
+        erts_link_release(lnk);
+    return reds_consumed;
+}
+
+int
+erts_proc_exit_handle_link(ErtsLink *lnk, void *vctxt, Sint reds)
 {
+    ErtsProcExitContext *ctxt = (ErtsProcExitContext *) vctxt;
     Process *c_p = ((ErtsProcExitContext *) vctxt)->c_p;
     Eterm reason = ((ErtsProcExitContext *) vctxt)->reason;
     ErtsLinkData *ldp = NULL;
@@ -12219,32 +12426,40 @@ erts_proc_exit_handle_link(ErtsLink *lnk, void *vctxt)
         DistEntry *dep;
         ErtsMonLnkDist *dist;
         ErtsLink *dlnk;
-        ErtsDSigData dsd;
+        ErtsDSigSendContext ctx;
         int code;
 
-        dlnk = erts_link_to_other(lnk, &ldp);
-        dist = ((ErtsLinkDataExtended *) ldp)->dist;
+        if (is_immed(reason)) {
+            dlnk = erts_link_to_other(lnk, &ldp);
+            dist = ((ErtsLinkDataExtended *) ldp)->dist;
 
-        ASSERT(is_external_pid(lnk->other.item));
-        dep = external_pid_dist_entry(lnk->other.item);
+            ASSERT(is_external_pid(lnk->other.item));
+            dep = external_pid_dist_entry(lnk->other.item);
 
-        ASSERT(dep != erts_this_dist_entry);
+            ASSERT(dep != erts_this_dist_entry);
 
-        if (!erts_link_dist_delete(dlnk))
-            ldp = NULL;
+            if (!erts_link_dist_delete(dlnk))
+                ldp = NULL;
 
-        code = erts_dsig_prepare(&dsd, dep, c_p, 0, ERTS_DSP_NO_LOCK, 0, 0);
-        switch (code) {
-        case ERTS_DSIG_PREP_CONNECTED:
-        case ERTS_DSIG_PREP_PENDING:
-            if (dist->connection_id == dsd.connection_id) {
-                code = erts_dsig_send_exit_tt(&dsd,
-                                              c_p->common.id,
-                                              lnk->other.item,
-                                              reason,
-                                              SEQ_TRACE_TOKEN(c_p));
-                ASSERT(code == ERTS_DSIG_SEND_OK);
+            code = erts_dsig_prepare(&ctx, dep, c_p, 0, ERTS_DSP_NO_LOCK, 1, 1, 0);
+            switch (code) {
+            case ERTS_DSIG_PREP_CONNECTED:
+            case ERTS_DSIG_PREP_PENDING:
+                if (dist->connection_id == ctx.connection_id) {
+                    code = erts_dsig_send_exit_tt(&ctx,
+                                                  c_p->common.id,
+                                                  lnk->other.item,
+                                                  reason,
+                                                  SEQ_TRACE_TOKEN(c_p));
+                    ASSERT(code == ERTS_DSIG_SEND_OK);
+                }
+                break;
+            default:
+                break;
             }
+        } else {
+            erts_link_tree_insert(&ctxt->dist_links, lnk);
+            return 1;
         }
         break;
     }
@@ -12257,6 +12472,7 @@ erts_proc_exit_handle_link(ErtsLink *lnk, void *vctxt)
         erts_link_release_both(ldp);
     else if (lnk)
         erts_link_release(lnk);
+    return 1;
 }
 
 /* this function fishishes a process and propagates exit messages - called
@@ -12290,11 +12506,8 @@ erts_do_exit_process(Process* p, Eterm reason)
 
     set_self_exiting(p, reason, NULL, NULL, NULL);
 
-    if (IS_TRACED(p)) {
-	if (IS_TRACED_FL(p, F_TRACE_CALLS))
-	    erts_schedule_time_break(p, ERTS_BP_CALL_TIME_SCHEDULE_EXITING);
-
-    }
+    if (IS_TRACED_FL(p, F_TRACE_CALLS))
+        erts_schedule_time_break(p, ERTS_BP_CALL_TIME_SCHEDULE_EXITING);
 
     erts_trace_check_exiting(p->common.id);
 
@@ -12309,288 +12522,454 @@ erts_do_exit_process(Process* p, Eterm reason)
 
     erts_proc_unlock(p, ERTS_PROC_LOCKS_ALL_MINOR);
 
-    if (IS_TRACED_FL(p,F_TRACE_PROCS))
+    if (IS_TRACED_FL(p, F_TRACE_PROCS))
         trace_proc(p, ERTS_PROC_LOCK_MAIN, p, am_exit, reason);
 
-
     /*
      * p->u.initial of this process can *not* be used anymore;
      * will be overwritten by misc termination data.
      */
     p->u.terminate = NULL;
 
+    BUMP_REDS(p, 100);
+
     erts_continue_exit_process(p);
 }
 
-void
-erts_continue_exit_process(Process *p)
-{
+enum continue_exit_phase {
+    ERTS_CONTINUE_EXIT_TIMERS,
+    ERTS_CONTINUE_EXIT_BLCKD_MSHED,
+    ERTS_CONTINUE_EXIT_BLCKD_NMSHED,
+    ERTS_CONTINUE_EXIT_USING_DB,
+    ERTS_CONTINUE_EXIT_CLEAN_SYS_TASKS,
+    ERTS_CONTINUE_EXIT_FREE,
+    ERTS_CONTINUE_EXIT_CLEAN_SYS_TASKS_AFTER,
+    ERTS_CONTINUE_EXIT_LINKS,
+    ERTS_CONTINUE_EXIT_MONITORS,
+    ERTS_CONTINUE_EXIT_LT_MONITORS,
+    ERTS_CONTINUE_EXIT_HANDLE_PROC_SIG,
+    ERTS_CONTINUE_EXIT_DIST_LINKS,
+    ERTS_CONTINUE_EXIT_DIST_MONITORS,
+    ERTS_CONTINUE_EXIT_DONE,
+};
+
+struct continue_exit_state {
+    enum continue_exit_phase phase;
     ErtsLink *links;
     ErtsMonitor *monitors;
     ErtsMonitor *lt_monitors;
+    Eterm reason;
+    ErtsProcExitContext pectxt;
+    DistEntry *dep;
+    void *yield_state;
+};
+
+void
+erts_continue_exit_process(Process *p)
+{
+    struct continue_exit_state static_state, *trap_state = &static_state;
     ErtsProcLocks curr_locks = ERTS_PROC_LOCK_MAIN;
-    Eterm reason = p->fvalue;
-    DistEntry *dep = NULL;
     erts_aint32_t state;
     int delay_del_proc = 0;
-    ErtsProcExitContext pectxt;
-
+    Sint reds = ERTS_BIF_REDS_LEFT(p);
 #ifdef DEBUG
     int yield_allowed = 1;
 #endif
 
+    if (p->u.terminate) {
+        trap_state = p->u.terminate;
+        /* Re-set the reason as it may have been gc:ed */
+        trap_state->reason = p->fvalue;
+    } else {
+        trap_state->phase = ERTS_CONTINUE_EXIT_TIMERS;
+        trap_state->reason = p->fvalue;
+        trap_state->dep = NULL;
+        trap_state->yield_state = NULL;
+    }
+
     ERTS_LC_ASSERT(ERTS_PROC_LOCK_MAIN == erts_proc_lc_my_proc_locks(p));
 
     ASSERT(ERTS_PROC_IS_EXITING(p));
 
     ASSERT(erts_proc_read_refc(p) > 0);
-    if (p->bif_timers) {
-	if (erts_cancel_bif_timers(p, &p->bif_timers, &p->u.terminate)) {
-	    ASSERT(erts_proc_read_refc(p) > 0);
-	    goto yield;
-	}
-	ASSERT(erts_proc_read_refc(p) > 0);
-	p->bif_timers = NULL;
-    }
-
-    if (p->flags & F_SCHDLR_ONLN_WAITQ)
-	abort_sched_onln_chng_waitq(p);
-
-    if (p->flags & F_HAVE_BLCKD_MSCHED) {
-	ErtsSchedSuspendResult ssr;
-	ssr = erts_block_multi_scheduling(p, ERTS_PROC_LOCK_MAIN, 0, 0, 1);
-	switch (ssr) {
-	case ERTS_SCHDLR_SSPND_YIELD_RESTART:
-	    goto yield;
-	case ERTS_SCHDLR_SSPND_DONE_MSCHED_BLOCKED:
-	case ERTS_SCHDLR_SSPND_DONE_NMSCHED_BLOCKED:
-	case ERTS_SCHDLR_SSPND_YIELD_DONE_MSCHED_BLOCKED:
-	case ERTS_SCHDLR_SSPND_YIELD_DONE_NMSCHED_BLOCKED:
-	case ERTS_SCHDLR_SSPND_DONE:
-	case ERTS_SCHDLR_SSPND_YIELD_DONE:
-	    p->flags &= ~F_HAVE_BLCKD_MSCHED;
-	    break;
-	case ERTS_SCHDLR_SSPND_EINVAL:
-	default:
-	    erts_exit(ERTS_ABORT_EXIT, "%s:%d: Internal error: %d\n",
-		      __FILE__, __LINE__, (int) ssr);
-	}
-    }
-    if (p->flags & F_HAVE_BLCKD_NMSCHED) {
-	ErtsSchedSuspendResult ssr;
-	ssr = erts_block_multi_scheduling(p, ERTS_PROC_LOCK_MAIN, 0, 1, 1);
-	switch (ssr) {
-	case ERTS_SCHDLR_SSPND_YIELD_RESTART:
-	    goto yield;
-	case ERTS_SCHDLR_SSPND_DONE_MSCHED_BLOCKED:
-	case ERTS_SCHDLR_SSPND_DONE_NMSCHED_BLOCKED:
-	case ERTS_SCHDLR_SSPND_YIELD_DONE_MSCHED_BLOCKED:
-	case ERTS_SCHDLR_SSPND_YIELD_DONE_NMSCHED_BLOCKED:
-	case ERTS_SCHDLR_SSPND_DONE:
-	case ERTS_SCHDLR_SSPND_YIELD_DONE:
-	    p->flags &= ~F_HAVE_BLCKD_MSCHED;
-	    break;
-	case ERTS_SCHDLR_SSPND_EINVAL:
-	default:
-	    erts_exit(ERTS_ABORT_EXIT, "%s:%d: Internal error: %d\n",
-		     __FILE__, __LINE__, (int) ssr);
-	}
-    }
+restart:
+    switch (trap_state->phase) {
+    case ERTS_CONTINUE_EXIT_TIMERS:
+        if (p->bif_timers) {
+            reds = erts_cancel_bif_timers(p, &p->bif_timers, &trap_state->yield_state, reds);
+            if (reds <= 0) goto yield;
+            p->bif_timers = NULL;
+        }
 
-    if (p->flags & F_USING_DB) {
-	if (erts_db_process_exiting(p, ERTS_PROC_LOCK_MAIN))
-	    goto yield;
-	p->flags &= ~F_USING_DB;
-    }
+        if (p->flags & F_SCHDLR_ONLN_WAITQ) {
+            abort_sched_onln_chng_waitq(p);
+            reds -= 100;
+        }
 
-    erts_set_gc_state(p, 1);
-    state = erts_atomic32_read_acqb(&p->state);
-    if ((state & ERTS_PSFLG_SYS_TASKS) || p->dirty_sys_tasks) {
-	if (cleanup_sys_tasks(p, state, CONTEXT_REDS) >= CONTEXT_REDS/2)
-	    goto yield;
-    }
+        trap_state->phase = ERTS_CONTINUE_EXIT_BLCKD_MSHED;
+        if (reds <= 0) goto yield;
+    case ERTS_CONTINUE_EXIT_BLCKD_MSHED:
+
+        if (p->flags & F_HAVE_BLCKD_MSCHED) {
+            ErtsSchedSuspendResult ssr;
+            ssr = erts_block_multi_scheduling(p, ERTS_PROC_LOCK_MAIN, 0, 0, 1);
+            switch (ssr) {
+            case ERTS_SCHDLR_SSPND_DONE:
+            case ERTS_SCHDLR_SSPND_DONE_MSCHED_BLOCKED:
+            case ERTS_SCHDLR_SSPND_DONE_NMSCHED_BLOCKED:
+                p->flags &= ~F_HAVE_BLCKD_MSCHED;
+                break;
+            default:
+                erts_exit(ERTS_ABORT_EXIT, "%s:%d: Internal error: %d\n",
+                          __FILE__, __LINE__, (int) ssr);
+            }
+            reds -= 100;
+        }
 
-#ifdef DEBUG
-    erts_proc_lock(p, ERTS_PROC_LOCK_STATUS);
-    ASSERT(ERTS_PROC_GET_DELAYED_GC_TASK_QS(p) == NULL);
-    ASSERT(p->dirty_sys_tasks == NULL);
-    erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
-#endif
+        trap_state->phase = ERTS_CONTINUE_EXIT_BLCKD_NMSHED;
+        if (reds <= 0) goto yield;
+    case ERTS_CONTINUE_EXIT_BLCKD_NMSHED:
+
+        if (p->flags & F_HAVE_BLCKD_NMSCHED) {
+            ErtsSchedSuspendResult ssr;
+            ssr = erts_block_multi_scheduling(p, ERTS_PROC_LOCK_MAIN, 0, 1, 1);
+            switch (ssr) {
+            case ERTS_SCHDLR_SSPND_DONE:
+            case ERTS_SCHDLR_SSPND_DONE_MSCHED_BLOCKED:
+            case ERTS_SCHDLR_SSPND_DONE_NMSCHED_BLOCKED:
+                p->flags &= ~F_HAVE_BLCKD_MSCHED;
+                break;
+            default:
+                erts_exit(ERTS_ABORT_EXIT, "%s:%d: Internal error: %d\n",
+                          __FILE__, __LINE__, (int) ssr);
+            }
+            reds -= 100;
+        }
 
-    if (p->flags & F_USING_DDLL) {
-	erts_ddll_proc_dead(p, ERTS_PROC_LOCK_MAIN);
-	p->flags &= ~F_USING_DDLL;
-    }
+        trap_state->yield_state = NULL;
+        trap_state->phase = ERTS_CONTINUE_EXIT_USING_DB;
+        if (reds <= 0) goto yield;
+    case ERTS_CONTINUE_EXIT_USING_DB:
 
-    /*
-     * The registered name *should* be the last "erlang resource" to
-     * cleanup.
-     */
-    if (p->common.u.alive.reg) {
-	(void) erts_unregister_name(p, ERTS_PROC_LOCK_MAIN, NULL, THE_NON_VALUE);
-	ASSERT(!p->common.u.alive.reg);
-    }
+        if (p->flags & F_USING_DB) {
+            if (erts_db_process_exiting(p, ERTS_PROC_LOCK_MAIN, &trap_state->yield_state))
+                goto yield;
+            p->flags &= ~F_USING_DB;
+        }
 
-    if (IS_TRACED_FL(p, F_TRACE_SCHED_EXIT))
-        trace_sched(p, curr_locks, am_out_exited);
+        trap_state->phase = ERTS_CONTINUE_EXIT_CLEAN_SYS_TASKS;
+    case ERTS_CONTINUE_EXIT_CLEAN_SYS_TASKS:
 
-    erts_proc_lock(p, ERTS_PROC_LOCKS_ALL_MINOR);
-    curr_locks = ERTS_PROC_LOCKS_ALL;
+        /* We enable GC again as it can produce more sys-tasks */
+        erts_set_gc_state(p, 1);
+        state = erts_atomic32_read_acqb(&p->state);
+        if ((state & ERTS_PSFLG_SYS_TASKS) || p->dirty_sys_tasks) {
+            reds -= cleanup_sys_tasks(p, state, reds);
+            if (reds <= 0) goto yield;
+        }
+
+        trap_state->phase = ERTS_CONTINUE_EXIT_FREE;
+    case ERTS_CONTINUE_EXIT_FREE:
 
-    /*
-     * From this point on we are no longer allowed to yield
-     * this process.
-     */
 #ifdef DEBUG
-    yield_allowed = 0;
+        erts_proc_lock(p, ERTS_PROC_LOCK_STATUS);
+        ASSERT(ERTS_PROC_GET_DELAYED_GC_TASK_QS(p) == NULL);
+        ASSERT(p->dirty_sys_tasks == NULL);
+        erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
 #endif
 
-    /*
-     * Note! The monitor and link fields will be overwritten 
-     * by erts_ptab_delete_element() below.
-     */
-    links = ERTS_P_LINKS(p);
-    monitors = ERTS_P_MONITORS(p);
-    lt_monitors = ERTS_P_LT_MONITORS(p);
+        if (p->flags & F_USING_DDLL) {
+            erts_ddll_proc_dead(p, ERTS_PROC_LOCK_MAIN);
+            p->flags &= ~F_USING_DDLL;
+        }
 
-    {
-	/* Do *not* use erts_get_runq_proc() */
-	ErtsRunQueue *rq;
-	rq = erts_get_runq_current(erts_proc_sched_data(p));
+        /*
+         * The registered name *should* be the last "erlang resource" to
+         * cleanup.
+         */
+        if (p->common.u.alive.reg) {
+            (void) erts_unregister_name(p, ERTS_PROC_LOCK_MAIN, NULL, THE_NON_VALUE);
+            ASSERT(!p->common.u.alive.reg);
+        }
 
-	erts_runq_lock(rq);
+        erts_proc_lock(p, ERTS_PROC_LOCKS_ALL_MINOR);
+        curr_locks = ERTS_PROC_LOCKS_ALL;
 
-	ASSERT(p->scheduler_data);
-	ASSERT(p->scheduler_data->current_process == p);
-	ASSERT(p->scheduler_data->free_process == NULL);
+        /*
+         * Note! The monitor and link fields will be overwritten 
+         * by erts_ptab_delete_element() below.
+         */
+        trap_state->links = ERTS_P_LINKS(p);
+        trap_state->monitors = ERTS_P_MONITORS(p);
+        trap_state->lt_monitors = ERTS_P_LT_MONITORS(p);
 
-	p->scheduler_data->current_process = NULL;
-	p->scheduler_data->free_process = p;
+        {
+            /* Do *not* use erts_get_runq_proc() */
+            ErtsRunQueue *rq;
+            rq = erts_get_runq_current(erts_proc_sched_data(p));
 
-	/* Time of death! */
-	erts_ptab_delete_element(&erts_proc, &p->common);
+            erts_runq_lock(rq);
 
-	erts_runq_unlock(rq);
-    }
+            ASSERT(p->scheduler_data);
+            ASSERT(p->scheduler_data->current_process == p);
+            ASSERT(p->scheduler_data->free_process == NULL);
 
-    /*
-     * All "erlang resources" have to be deallocated before this point,
-     * e.g. registered name, so monitoring and linked processes can
-     * be sure that all interesting resources have been deallocated
-     * when the monitors and/or links hit.
-     */
+            /* Time of death! */
+            erts_ptab_delete_element(&erts_proc, &p->common);
 
-    {
-	/* Inactivate and notify free */
-	erts_aint32_t n, e, a = erts_atomic32_read_nob(&p->state);
-	int refc_inced = 0;
-	while (1) {
-	    n = e = a;
-	    ASSERT(a & ERTS_PSFLG_EXITING);
-	    n |= ERTS_PSFLG_FREE;
-	    n &= ~(ERTS_PSFLG_ACTIVE
-                   | ERTS_PSFLG_ACTIVE_SYS
-                   | ERTS_PSFLG_DIRTY_ACTIVE_SYS);
-	    if ((n & ERTS_PSFLG_IN_RUNQ) && !refc_inced) {
-		erts_proc_inc_refc(p);
-		refc_inced = 1;
-	    }
-	    a = erts_atomic32_cmpxchg_mb(&p->state, n, e);
-	    if (a == e)
-		break;
-	}
+            erts_runq_unlock(rq);
+        }
 
-        if (a & (ERTS_PSFLG_DIRTY_RUNNING
-                 | ERTS_PSFLG_DIRTY_RUNNING_SYS)) {
-	    p->flags |= F_DELAYED_DEL_PROC;
-	    delay_del_proc = 1;
-	    /*
-	     * The dirty scheduler decrease refc
-             * when done with the process...
-	     */
-	}
+        /*
+         * All "erlang resources" have to be deallocated before this point,
+         * e.g. registered name, so monitoring and linked processes can
+         * be sure that all interesting resources have been deallocated
+         * when the monitors and/or links hit.
+         */
 
-	if (refc_inced && !(n & ERTS_PSFLG_IN_RUNQ))
-	    erts_proc_dec_refc(p);
-    }
+        {
+            /* Inactivate and notify free */
+            erts_aint32_t n, e, a = erts_atomic32_read_nob(&p->state);
+            int refc_inced = 0;
+            while (1) {
+                n = e = a;
+                ASSERT(a & ERTS_PSFLG_EXITING);
+                n |= ERTS_PSFLG_FREE;
+                if ((n & ERTS_PSFLG_IN_RUNQ) && !refc_inced) {
+                    erts_proc_inc_refc(p);
+                    refc_inced = 1;
+                }
+                a = erts_atomic32_cmpxchg_mb(&p->state, n, e);
+                if (a == e)
+                    break;
+            }
 
-    dep = ((p->flags & F_DISTRIBUTION)
-           ? ERTS_PROC_SET_DIST_ENTRY(p, NULL)
-           : NULL);
+            if (refc_inced && !(n & ERTS_PSFLG_IN_RUNQ))
+                erts_proc_dec_refc(p);
+        }
 
+        trap_state->dep = ((p->flags & F_DISTRIBUTION)
+                      ? ERTS_PROC_SET_DIST_ENTRY(p, NULL)
+                      : NULL);
+
+        reds -= 50;
 
-    /*
-     * It might show up signal prio elevation tasks until we
-     * have entered free state. Cleanup such tasks now.
-     */
-    state = erts_atomic32_read_acqb(&p->state);
-    if (!(state & ERTS_PSFLG_SYS_TASKS))
-        erts_proc_unlock(p, ERTS_PROC_LOCKS_ALL);
-    else {
         erts_proc_unlock(p, ERTS_PROC_LOCKS_ALL_MINOR);
+        curr_locks = ERTS_PROC_LOCK_MAIN;
+        trap_state->phase = ERTS_CONTINUE_EXIT_CLEAN_SYS_TASKS_AFTER;
+    case ERTS_CONTINUE_EXIT_CLEAN_SYS_TASKS_AFTER:
+        /*
+         * It might show up signal prio elevation tasks until we
+         * have entered free state. Cleanup such tasks now.
+         */
 
-        do {
-            (void) cleanup_sys_tasks(p, state, CONTEXT_REDS);
-            state = erts_atomic32_read_acqb(&p->state);
-        } while (state & ERTS_PSFLG_SYS_TASKS);
-        
-        erts_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
-    }
+        state = erts_atomic32_read_acqb(&p->state);
+        if ((state & ERTS_PSFLG_SYS_TASKS) || p->dirty_sys_tasks) {
+            reds -= cleanup_sys_tasks(p, state, reds);
+            if (reds <= 0) goto yield;
+        }
+
+        /* Needs to be unlocked for erts_do_net_exits to work?!? */
+        // erts_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
 
 #ifdef DEBUG
-    erts_proc_lock(p, ERTS_PROC_LOCK_STATUS);
-    ASSERT(p->sys_task_qs == NULL);
-    erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
+        erts_proc_lock(p, ERTS_PROC_LOCK_STATUS);
+        ASSERT(p->sys_task_qs == NULL);
+        erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
 #endif
 
-    if (dep) {
-        erts_do_net_exits(dep, (reason == am_kill) ? am_killed : reason);
-        erts_deref_dist_entry(dep);
-    }
+        if (trap_state->dep) {
+            erts_do_net_exits(trap_state->dep,
+                              (trap_state->reason == am_kill) ? am_killed : trap_state->reason);
+            erts_deref_dist_entry(trap_state->dep);
+        }
 
-    pectxt.c_p = p;
-    pectxt.reason = reason;
+        /* Disable GC so that reason does not get moved */
+        erts_set_gc_state(p, 0);
+
+        trap_state->pectxt.c_p = p;
+        trap_state->pectxt.reason = trap_state->reason;
+        trap_state->pectxt.dist_links = NULL;
+        trap_state->pectxt.dist_monitors = NULL;
+        trap_state->pectxt.dist_state = NIL;
+
+        erts_proc_lock(p, ERTS_PROC_LOCK_MSGQ);
+
+        erts_proc_sig_fetch(p);
+
+        erts_proc_unlock(p, ERTS_PROC_LOCK_MSGQ);
+
+        trap_state->yield_state = NULL;
+        trap_state->phase = ERTS_CONTINUE_EXIT_LINKS;
+        if (reds <= 0) goto yield;
+    case ERTS_CONTINUE_EXIT_LINKS:
+
+        reds = erts_link_tree_foreach_delete_yielding(
+            &trap_state->links,
+            erts_proc_exit_handle_link,
+            (void *) &trap_state->pectxt,
+            &trap_state->yield_state,
+            reds);
+        if (reds <= 0)
+            goto yield;
+
+        ASSERT(!trap_state->links);
+        trap_state->yield_state = NULL;
+        trap_state->phase = ERTS_CONTINUE_EXIT_MONITORS;
+    case ERTS_CONTINUE_EXIT_MONITORS:
+
+    reds = erts_monitor_tree_foreach_delete_yielding(
+            &trap_state->monitors,
+            erts_proc_exit_handle_monitor,
+            (void *) &trap_state->pectxt,
+            &trap_state->yield_state,
+            reds);
+        if (reds <= 0)
+            goto yield;
+
+        ASSERT(!trap_state->monitors);
+        trap_state->yield_state = NULL;
+        trap_state->phase = ERTS_CONTINUE_EXIT_LT_MONITORS;
+    case ERTS_CONTINUE_EXIT_LT_MONITORS:
+
+        reds = erts_monitor_list_foreach_delete_yielding(
+            &trap_state->lt_monitors,
+            erts_proc_exit_handle_monitor,
+            (void *) &trap_state->pectxt,
+            &trap_state->yield_state,
+            reds);
+        if (reds <= 0)
+            goto yield;
+
+        ASSERT(!trap_state->lt_monitors);
+        trap_state->phase = ERTS_CONTINUE_EXIT_HANDLE_PROC_SIG;
+    case ERTS_CONTINUE_EXIT_HANDLE_PROC_SIG: {
+        Sint r = reds;
+
+        if (!erts_proc_sig_handle_exit(p, &r))
+            goto yield;
+
+        reds -= r;
+
+        trap_state->phase = ERTS_CONTINUE_EXIT_DIST_LINKS;
+    }
+    case ERTS_CONTINUE_EXIT_DIST_LINKS: {
+
+        continue_dist_send:
+        if (is_not_nil(trap_state->pectxt.dist_state)) {
+            Binary* bin = erts_magic_ref2bin(trap_state->pectxt.dist_state);
+            ErtsDSigSendContext* ctx = (ErtsDSigSendContext*) ERTS_MAGIC_BIN_DATA(bin);
+            Sint initial_reds = (Sint) (ERTS_BIF_REDS_LEFT(p) * TERM_TO_BINARY_LOOP_FACTOR);
+            int result;
+
+            ctx->reds = initial_reds;
+            result = erts_dsig_send(ctx);
+
+            /* erts_dsig_send bumps reductions on the process in the ctx */
+            reds = ERTS_BIF_REDS_LEFT(p);
+
+            switch (result) {
+            case ERTS_DSIG_SEND_OK:
+                break;
+            case ERTS_DSIG_SEND_TOO_LRG: /*SEND_SYSTEM_LIMIT*/
+                erts_kill_dist_connection(ctx->dep, ctx->connection_id);
+                break;
+            case ERTS_DSIG_SEND_YIELD: /*SEND_YIELD_RETURN*/
+            case ERTS_DSIG_SEND_CONTINUE: { /*SEND_YIELD_CONTINUE*/
+                goto yield;
+            }
+            }
 
-    erts_proc_lock(p, ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_MSGQ);
+            trap_state->pectxt.dist_state = NIL;
+            if (reds <= 0)
+                goto yield;
+            goto restart;
+        }
 
-    erts_proc_sig_fetch(p);
+        reds = erts_link_tree_foreach_delete_yielding(
+            &trap_state->pectxt.dist_links,
+            erts_proc_exit_handle_dist_link,
+            (void *) &trap_state->pectxt,
+            &trap_state->yield_state,
+            reds);
+        if (reds <= 0 || is_not_nil(trap_state->pectxt.dist_state))
+            goto yield;
+        trap_state->phase = ERTS_CONTINUE_EXIT_DIST_MONITORS;
+    }
+    case ERTS_CONTINUE_EXIT_DIST_MONITORS: {
+
+        if (is_not_nil(trap_state->pectxt.dist_state))
+            goto continue_dist_send;
+
+        reds = erts_monitor_tree_foreach_delete_yielding(
+            &trap_state->pectxt.dist_monitors,
+            erts_proc_exit_handle_dist_monitor,
+            (void *) &trap_state->pectxt,
+            &trap_state->yield_state,
+            reds);
+        if (reds <= 0 || is_not_nil(trap_state->pectxt.dist_state))
+            goto yield;
+
+        trap_state->phase = ERTS_CONTINUE_EXIT_DONE;
+    }
+    case ERTS_CONTINUE_EXIT_DONE: {
+        erts_aint_t state;
+        /*
+         * From this point on we are no longer allowed to yield
+         * this process.
+         */
+#ifdef DEBUG
+        yield_allowed = 0;
+#endif
 
-    erts_proc_unlock(p, ERTS_PROC_LOCK_MSGQ);
+        /* Enable GC again, through strictly not needed it puts
+           the process in a consistent state. */
+        erts_set_gc_state(p, 1);
 
-    if (links) {
-        erts_link_tree_foreach_delete(&links,
-                                      erts_proc_exit_handle_link,
-                                      (void *) &pectxt);
-        ASSERT(!links);
-    }
+        /* Set state to not active as we don't want this process
+           to be scheduled in again after this. */
+        state = erts_atomic32_read_band_relb(&p->state,
+                                             ~(ERTS_PSFLG_ACTIVE
+                                               | ERTS_PSFLG_ACTIVE_SYS
+                                               | ERTS_PSFLG_DIRTY_ACTIVE_SYS));
 
-    if (monitors) {
-        erts_monitor_tree_foreach_delete(&monitors,
-                                         erts_proc_exit_handle_monitor,
-                                         (void *) &pectxt);
-        ASSERT(!monitors);
-    }
+        ASSERT(p->scheduler_data);
+        ASSERT(p->scheduler_data->current_process == p);
+        ASSERT(p->scheduler_data->free_process == NULL);
+
+        p->scheduler_data->current_process = NULL;
+        p->scheduler_data->free_process = p;
+
+        if (state & (ERTS_PSFLG_DIRTY_RUNNING
+                     | ERTS_PSFLG_DIRTY_RUNNING_SYS)) {
+            p->flags |= F_DELAYED_DEL_PROC;
+            delay_del_proc = 1;
+            /*
+             * The dirty scheduler decrease refc
+             * when done with the process...
+             */
+        }
 
-    if (lt_monitors) {
-        erts_monitor_list_foreach_delete(&lt_monitors,
-                                         erts_proc_exit_handle_monitor,
-                                         (void *) &pectxt);
-        ASSERT(!lt_monitors);
+        erts_schedule_thr_prgr_later_cleanup_op(
+            (void (*)(void*))erts_proc_dec_refc,
+            (void *) &p->common,
+            &p->common.u.release,
+            sizeof(Process));
+
+        break;
+    }
     }
 
-    /*
-     * erts_proc_sig_handle_exit() implements yielding.
-     * However, this function cannot handle it yet... loop
-     * until done...
-     */
-    while (!0) {
-        int reds = CONTEXT_REDS;
-        if (erts_proc_sig_handle_exit(p, &reds))
-            break;
+    if (trap_state != &static_state) {
+        erts_free(ERTS_ALC_T_CONT_EXIT_TRAP, trap_state);
+        p->u.terminate = NULL;
     }
 
     ERTS_CHK_HAVE_ONLY_MAIN_PROC_LOCK(p);
 
+    if (IS_TRACED_FL(p, F_TRACE_SCHED_EXIT))
+        trace_sched(p, curr_locks, am_out_exited);
+
     erts_flush_trace_messages(p, ERTS_PROC_LOCK_MAIN);
 
     ERTS_TRACER_CLEAR(&ERTS_TRACER(p));
@@ -12602,15 +12981,30 @@ erts_continue_exit_process(Process *p)
 
  yield:
 
-#ifdef DEBUG
     ASSERT(yield_allowed);
-#endif
 
     ERTS_LC_ASSERT(curr_locks == erts_proc_lc_my_proc_locks(p));
     ERTS_LC_ASSERT(ERTS_PROC_LOCK_MAIN & curr_locks);
+    ASSERT(erts_proc_read_refc(p) > 0);
+
+    if (trap_state == &static_state) {
+        trap_state = erts_alloc(ERTS_ALC_T_CONT_EXIT_TRAP, sizeof(*trap_state));
+        sys_memcpy(trap_state, &static_state, sizeof(*trap_state));
+        p->u.terminate = trap_state;
+    }
+
+    ASSERT(p->scheduler_data);
+    ASSERT(p->scheduler_data->current_process == p);
+    ASSERT(p->scheduler_data->free_process == NULL);
+
+    if (trap_state->phase >= ERTS_CONTINUE_EXIT_FREE) {
+        p->scheduler_data->current_process = NULL;
+        p->scheduler_data->free_process = p;
+    }
 
     p->i = (BeamInstr *) beam_continue_exit;
 
+    /* Why is this lock take??? */
     if (!(curr_locks & ERTS_PROC_LOCK_STATUS)) {
 	erts_proc_lock(p, ERTS_PROC_LOCK_STATUS);
 	curr_locks |= ERTS_PROC_LOCK_STATUS;
@@ -13026,10 +13420,10 @@ void erts_halt(int code)
     if (-1 == erts_atomic32_cmpxchg_acqb(&erts_halt_progress,
 					     erts_no_schedulers,
 					     -1)) {
+        notify_reap_ports_relb();
         ERTS_RUNQ_FLGS_SET(ERTS_DIRTY_CPU_RUNQ, ERTS_RUNQ_FLG_HALTING);
         ERTS_RUNQ_FLGS_SET(ERTS_DIRTY_IO_RUNQ, ERTS_RUNQ_FLG_HALTING);
 	erts_halt_code = code;
-	notify_reap_ports_relb();
     }
 }
 
@@ -13074,3 +13468,79 @@ erts_debug_later_op_foreach(void (*callback)(void*),
         }
     }
 }
+
+void
+erts_debug_free_process_foreach(void (*func)(Process *, void *), void *arg)
+{
+    ErtsRunQueue *rq;
+    int ix, prio;
+    for (ix = 0; ix < erts_no_run_queues; ix++) {
+        rq = ERTS_RUNQ_IX(ix);
+        for (prio = PRIORITY_MAX; prio < PRIORITY_LOW; prio++) {
+            Process *p = rq->procs.prio[prio].first;
+            for (; p; p = p->next) {
+                if (ERTS_PSFLG_FREE & erts_atomic32_read_nob(&p->state))
+                    (*func)(p, arg);
+            }
+        }
+    }
+}
+
+void
+erts_debug_proc_monitor_link_foreach(Process *proc,
+                                     int (*monitor_func)(ErtsMonitor *, void *, Sint ),
+                                     int (*link_func)(ErtsLink *, void *, Sint ),
+                                     void *arg)
+{
+    if (!(erts_atomic32_read_nob(&proc->state) & ERTS_PSFLG_FREE)) {
+        /* For all links */
+        erts_link_tree_foreach(ERTS_P_LINKS(proc),
+                               link_func,
+                               arg);
+        /* For all monitors */
+        erts_monitor_tree_foreach(ERTS_P_MONITORS(proc),
+                                  monitor_func,
+                                  arg);
+        /* For all local target monitors */
+        erts_monitor_list_foreach(ERTS_P_LT_MONITORS(proc),
+                                  monitor_func,
+                                  arg);
+    }
+    else {
+        struct continue_exit_state *ce_state = proc->u.terminate;
+
+        /* For all links */
+        if (ce_state->phase == ERTS_CONTINUE_EXIT_LINKS)
+            erts_debug_link_tree_destroying_foreach(ce_state->links,
+                                                    link_func,
+                                                    arg,
+                                                    ce_state->yield_state);
+        else
+            erts_link_tree_foreach(ce_state->links,
+                                   link_func,
+                                   arg);
+
+        /* For all monitors */
+        if (ce_state->phase == ERTS_CONTINUE_EXIT_MONITORS)
+            erts_debug_monitor_tree_destroying_foreach(ce_state->monitors,
+                                                       monitor_func,
+                                                       arg,
+                                                       ce_state->yield_state);
+        else
+            erts_monitor_tree_foreach(ce_state->monitors,
+                                      monitor_func,
+                                      arg);
+
+        /* For all local target monitors */
+        if (ce_state->phase == ERTS_CONTINUE_EXIT_LT_MONITORS)
+            erts_debug_monitor_list_destroying_foreach(ce_state->lt_monitors,
+                                                       monitor_func,
+                                                       arg,
+                                                       ce_state->yield_state);
+        else
+            erts_monitor_list_foreach(ce_state->lt_monitors,
+                                      monitor_func,
+                                      arg);
+
+    }
+}
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index a1b029adbe..c0d7cfd13d 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -173,8 +173,6 @@ extern int erts_dio_sched_thread_suggested_stack_size;
   (((Uint32) 1) << (ERTS_RUNQ_FLG_BASE2 + 9))
 #define ERTS_RUNQ_FLG_HALTING \
   (((Uint32) 1) << (ERTS_RUNQ_FLG_BASE2 + 10))
-#define ERTS_RUNQ_FLG_CHECKIO \
-  (((Uint32) 1) << (ERTS_RUNQ_FLG_BASE2 + 11))
 
 #define ERTS_RUNQ_FLG_MAX (ERTS_RUNQ_FLG_BASE2 + 12)
 
@@ -359,7 +357,7 @@ typedef struct ErtsSchedulerSleepInfo_ ErtsSchedulerSleepInfo;
 
 typedef struct {
     erts_spinlock_t lock;
-    ErtsSchedulerSleepInfo *list;
+    ErtsSchedulerSleepInfo *list; /* circular lifo list; points to last out */
 } ErtsSchedulerSleepList;
 
 struct ErtsSchedulerSleepInfo_ {
@@ -383,7 +381,10 @@ struct ErtsSchedulerSleepInfo_ {
 
 typedef struct ErtsProcList_ ErtsProcList;
 struct ErtsProcList_ {
-    Eterm pid;
+    union {
+        Eterm pid;
+        Process *p;
+    } u;
     Uint64 started_interval;
     ErtsProcList* next;
     ErtsProcList* prev;
@@ -640,6 +641,7 @@ struct ErtsSchedulerData_ {
     ErtsSchedType type;
     Uint no;			/* Scheduler number for normal schedulers */
     Uint dirty_no;  /* Scheduler number for dirty schedulers */
+    int flxctr_slot_no; /* slot nr when a flxctr is used */
     struct enif_environment_t *current_nif;
     Process *dirty_shadow_process;
     Port *current_port;
@@ -699,6 +701,13 @@ void
 erts_debug_later_op_foreach(void (*callback)(void*),
                             void (*func)(void *, ErtsThrPrgrVal, void *),
                             void *arg);
+void
+erts_debug_free_process_foreach(void (*func)(Process *, void *), void *arg);
+void
+erts_debug_proc_monitor_link_foreach(Process *proc,
+                                     int (*monitor_func)(ErtsMonitor *, void *, Sint ),
+                                     int (*link_func)(ErtsLink *, void *, Sint ),
+                                     void *arg);
 
 #ifdef ERTS_INCLUDE_SCHEDULER_INTERNALS
 
@@ -1228,9 +1237,10 @@ void erts_check_for_holes(Process* p);
 
 /* The sequential tracing token is a tuple of size 5:
  *
- *    {Flags, Label, Serial, Sender}
+ *    {Flags, Label, Serial, Sender, LastCnt}
+ *
+ *  WARNING: The top 5-tuple is *MUTABLE* and thus INTERNAL ONLY.
  */
-
 #define SEQ_TRACE_TOKEN_ARITY(p)    (arityval(*(tuple_val(SEQ_TRACE_TOKEN(p)))))
 #define SEQ_TRACE_TOKEN_FLAGS(p)    (*(tuple_val(SEQ_TRACE_TOKEN(p)) + 1))
 #define SEQ_TRACE_TOKEN_LABEL(p)    (*(tuple_val(SEQ_TRACE_TOKEN(p)) + 2))
@@ -1321,9 +1331,6 @@ ERTS_GLB_INLINE void erts_heap_frag_shrink(Process* p, Eterm* hp)
 #endif /* inline */
 
 Eterm* erts_heap_alloc(Process* p, Uint need, Uint xtra);
-#ifdef CHECK_FOR_HOLES
-Eterm* erts_set_hole_marker(Eterm* ptr, Uint sz);
-#endif
 
 extern erts_rwmtx_t erts_cpu_bind_rwmtx;
 /* If any of the erts_system_monitor_* variables are set (enabled),
@@ -1582,7 +1589,7 @@ ERTS_GLB_INLINE int erts_proclist_is_last(ErtsProcList *, ErtsProcList *);
 ERTS_GLB_INLINE int
 erts_proclist_same(ErtsProcList *plp, Process *p)
 {
-    return (plp->pid == p->common.id
+    return ((plp->u.pid == p->common.id || plp->u.p == p)
 	    && (plp->started_interval
 		== p->common.u.alive.started_interval));
 }
@@ -1821,9 +1828,12 @@ Eterm erts_process_info(Process *c_p, ErtsHeapFactory *hfact,
 typedef struct {
     Process *c_p;
     Eterm reason;
+    ErtsLink *dist_links;
+    ErtsMonitor *dist_monitors;
+    Eterm dist_state;
 } ErtsProcExitContext;
-void erts_proc_exit_handle_monitor(ErtsMonitor *mon, void *vctxt);
-void erts_proc_exit_handle_link(ErtsLink *lnk, void *vctxt);
+int erts_proc_exit_handle_monitor(ErtsMonitor *mon, void *vctxt, Sint reds);
+int erts_proc_exit_handle_link(ErtsLink *lnk, void *vctxt, Sint reds);
 
 Eterm erts_get_process_priority(erts_aint32_t state);
 Eterm erts_set_process_priority(Process *p, Eterm prio);
@@ -1846,12 +1856,14 @@ int erts_resume_processes(ErtsProcList *);
 void erts_deep_process_dump(fmtfn_t, void *);
 
 Eterm erts_get_reader_groups_map(Process *c_p);
+Eterm erts_get_decentralized_counter_groups_map(Process *c_p);
 Eterm erts_debug_reader_groups_map(Process *c_p, int groups);
 
 Uint erts_debug_nbalance(void);
 
 #define ERTS_DEBUG_WAIT_COMPLETED_DEALLOCATIONS		(1 << 0)
 #define ERTS_DEBUG_WAIT_COMPLETED_TIMER_CANCELLATIONS	(1 << 1)
+#define ERTS_DEBUG_WAIT_COMPLETED_AUX_WORK		(1 << 2)
 
 int erts_debug_wait_completed(Process *c_p, int flags);
 
@@ -2348,6 +2360,8 @@ erts_try_change_runq_proc(Process *p, ErtsRunQueue *rq)
                                             old_rqint);
         if (act_rqint == old_rqint)
             return !0;
+
+        old_rqint = act_rqint;
     }
 }
 
@@ -2627,6 +2641,9 @@ void erts_notify_inc_runq(ErtsRunQueue *runq);
 void erts_sched_finish_poke(ErtsSchedulerSleepInfo *, erts_aint32_t);
 ERTS_GLB_INLINE void erts_sched_poke(ErtsSchedulerSleepInfo *ssi);
 void erts_aux_thread_poke(void);
+ERTS_GLB_INLINE Uint32 erts_sched_local_random_hash_64_to_32_shift(Uint64 key);
+ERTS_GLB_INLINE Uint32 erts_sched_local_random(Uint additional_seed);
+
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
@@ -2643,6 +2660,39 @@ erts_sched_poke(ErtsSchedulerSleepInfo *ssi)
 }
 
 
+/*
+ * Source: https://gist.github.com/badboy/6267743
+ *         http://web.archive.org/web/20071223173210/http://www.concentric.net/~Ttwang/tech/inthash.htm
+ */
+ERTS_GLB_INLINE
+Uint32 erts_sched_local_random_hash_64_to_32_shift(Uint64 key)
+{
+    key = (~key) + (key << 18); /* key = (key << 18) - key - 1; */
+    key = key ^ (key >> 31);
+    key = (key + (key << 2)) + (key << 4);
+    key = key ^ (key >> 11);
+    key = key + (key << 6);
+    key = key ^ (key >> 22);
+    return (Uint32) key;
+}
+
+/*
+ * This function attempts to return a random number based on the state
+ * of the scheduler, the current process and the additional_seed
+ * parameter.
+ */
+ERTS_GLB_INLINE
+Uint32 erts_sched_local_random(Uint additional_seed)
+{
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    Uint64 seed =
+        additional_seed +
+        esdp->reductions +
+        esdp->current_process->fcalls +
+        (((Uint64)esdp->no) << 32);
+    return erts_sched_local_random_hash_64_to_32_shift(seed);
+}
+
 #endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
 
 
diff --git a/erts/emulator/beam/erl_process_dump.c b/erts/emulator/beam/erl_process_dump.c
index ac5054ea10..71262061dd 100644
--- a/erts/emulator/beam/erl_process_dump.c
+++ b/erts/emulator/beam/erl_process_dump.c
@@ -100,16 +100,18 @@ erts_deep_process_dump(fmtfn_t to, void *to_arg)
     dump_binaries(to, to_arg, all_binaries);
 }
 
-static void
-monitor_size(ErtsMonitor *mon, void *vsize)
+static int
+monitor_size(ErtsMonitor *mon, void *vsize, Sint reds)
 {
     *((Uint *) vsize) += erts_monitor_size(mon);
+    return 1;
 }
 
-static void
-link_size(ErtsMonitor *lnk, void *vsize)
+static int
+link_size(ErtsMonitor *lnk, void *vsize, Sint reds)
 {
     *((Uint *) vsize) += erts_link_size(lnk);
+    return 1;
 }
 
 Uint erts_process_memory(Process *p, int include_sigs_in_transit)
@@ -119,12 +121,14 @@ Uint erts_process_memory(Process *p, int include_sigs_in_transit)
 
     size += sizeof(Process);
 
-    erts_link_tree_foreach(ERTS_P_LINKS(p),
-                           link_size, (void *) &size);
-    erts_monitor_tree_foreach(ERTS_P_MONITORS(p),
-                              monitor_size, (void *) &size);
-    erts_monitor_list_foreach(ERTS_P_LT_MONITORS(p),
-                              monitor_size, (void *) &size);
+    if ((erts_atomic32_read_nob(&p->state) & ERTS_PSFLG_EXITING) == 0) {
+        erts_link_tree_foreach(ERTS_P_LINKS(p),
+                               link_size, (void *) &size);
+        erts_monitor_tree_foreach(ERTS_P_MONITORS(p),
+                                  monitor_size, (void *) &size);
+        erts_monitor_list_foreach(ERTS_P_LT_MONITORS(p),
+                                  monitor_size, (void *) &size);
+    }
     size += (p->heap_sz + p->mbuf_sz) * sizeof(Eterm);
     if (p->abandoned_heap)
         size += (p->hend - p->heap) * sizeof(Eterm);
@@ -189,11 +193,11 @@ static ERTS_INLINE void
 dump_msg(fmtfn_t to, void *to_arg, ErtsMessage *mp)
 {
     if (ERTS_SIG_IS_MSG((ErtsSignal *) mp)) {
-        Eterm mesg = ERL_MESSAGE_TERM(mp);
-        if (is_value(mesg))
-            dump_element(to, to_arg, mesg);
+        Eterm mesg;
+        if (ERTS_SIG_IS_INTERNAL_MSG(mp))
+            dump_element(to, to_arg, ERL_MESSAGE_TERM(mp));
         else
-            dump_dist_ext(to, to_arg, mp->data.dist_ext);
+            dump_dist_ext(to, to_arg, erts_get_dist_ext(mp->data.heap_frag));
         mesg = ERL_MESSAGE_TOKEN(mp);
         erts_print(to, to_arg, ":");
         dump_element(to, to_arg, mesg);
@@ -265,6 +269,7 @@ dump_dist_ext(fmtfn_t to, void *to_arg, ErtsDistExternal *edep)
     else {
 	byte *e;
 	size_t sz;
+        int i;
 
 	if (!(edep->flags & ERTS_DIST_EXT_ATOM_TRANS_TAB))
 	    erts_print(to, to_arg, "D0:");
@@ -274,8 +279,8 @@ dump_dist_ext(fmtfn_t to, void *to_arg, ErtsDistExternal *edep)
 	    for (i = 0; i < edep->attab.size; i++)
 		dump_element(to, to_arg, edep->attab.atom[i]);
 	}
-	sz = edep->ext_endp - edep->extp;
-	e = edep->extp;
+	sz = edep->data->ext_endp - edep->data->extp;
+	e = edep->data->extp;
 	if (edep->flags & ERTS_DIST_EXT_DFLAG_HDR) {
 	    ASSERT(*e != VERSION_MAGIC);
 	    sz++;
@@ -286,15 +291,19 @@ dump_dist_ext(fmtfn_t to, void *to_arg, ErtsDistExternal *edep)
 	erts_print(to, to_arg, "E%X:", sz);
         if (edep->flags & ERTS_DIST_EXT_DFLAG_HDR) {
             byte sbuf[3];
-            int i = 0;
+
+            i = 0;
 
             sbuf[i++] = VERSION_MAGIC;
-            while (i < sizeof(sbuf) && e < edep->ext_endp) {
+            while (i < sizeof(sbuf) && e < edep->data->ext_endp) {
                 sbuf[i++] = *e++;
             }
             erts_print_base64(to, to_arg, sbuf, i);
         }
-        erts_print_base64(to, to_arg, e, edep->ext_endp - e);
+        erts_print_base64(to, to_arg, e, edep->data->ext_endp - e);
+        for (i = 1; i < edep->data->frag_id; i++)
+            erts_print_base64(to, to_arg, edep->data[i].extp,
+                              edep->data[i].ext_endp - edep->data[i].extp);
     }
 }
 
@@ -1005,6 +1014,10 @@ dump_module_literals(fmtfn_t to, void *to_arg, ErtsLiteralArea* lit_area)
             }
             size = 1 + header_arity(w);
             switch (w & _HEADER_SUBTAG_MASK) {
+            case FUN_SUBTAG:
+                ASSERT(((ErlFunThing*)(htop))->num_free == 0);
+                size += 1;
+                break;
             case MAP_SUBTAG:
                 if (is_flatmap_header(w)) {
                     size += 1 + flatmap_get_size(htop);
diff --git a/erts/emulator/beam/erl_ptab.h b/erts/emulator/beam/erl_ptab.h
index 94f0247492..c30a684002 100644
--- a/erts/emulator/beam/erl_ptab.h
+++ b/erts/emulator/beam/erl_ptab.h
@@ -68,8 +68,11 @@ typedef struct {
 	    Uint64 started_interval;
 	    struct reg_proc *reg;
 	    ErtsLink *links;
-	    ErtsMonitor *monitors;
+             /* Local target monitors, double linked list
+                contains the remote part of local monitors  */
             ErtsMonitor *lt_monitors;
+             /* other monitors, rb tree */
+	    ErtsMonitor *monitors;
 	} alive;
 
 	/* --- While being released --- */
diff --git a/erts/emulator/beam/erl_rbtree.h b/erts/emulator/beam/erl_rbtree.h
index e50abf5cec..ce401fa7e7 100644
--- a/erts/emulator/beam/erl_rbtree.h
+++ b/erts/emulator/beam/erl_rbtree.h
@@ -161,7 +161,7 @@
  *
  * - void <ERTS_RBT_PREFIX>_rbt_foreach(
  *                         ERTS_RBT_T *tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
  *                         void *arg);
  *         Operate by calling the operator 'op' on each element.
  *         Order is undefined.
@@ -170,7 +170,7 @@
  *
  * - void <ERTS_RBT_PREFIX>_rbt_foreach_destroy(
  *                         ERTS_RBT_T *tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
  *                         void *arg);
  *         Operate by calling the operator 'op' on each element.
  *         Order is undefined. Each element should be destroyed
@@ -180,39 +180,46 @@
  *
  * - int <ERTS_RBT_PREFIX>_rbt_foreach_yielding(
  *                         ERTS_RBT_T *tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
  *                         void *arg,
  *                         <ERTS_RBT_PREFIX>_rbt_yield_state_t *ystate,
- *                         Sint ylimit);
+ *                         Sint reds);
  *         Operate by calling the operator 'op' on each element.
  *         Order is undefined.
  *
- *         Yield when 'ylimit' elements has been processed. True is
- *         returned when yielding, and false is returned when
- *         the whole tree has been processed. The tree should not be
- *         modified until all of it has been processed.
+ *         Yield when 'reds' reductions has been processed. The 'op'
+ *         function return the number of reductions that each element
+ *         took to process. The number of reductions remaining is returned,
+ *         meaning that if 0 is returned, there are more elements to be
+ *         processed. If a value greater than 0 is returned the foreach has
+ *         ended. The tree should not be modified until all of it has been
+ *         processed.
  *
  *         'arg' is passed as argument to 'op'.
  *
  * - int <ERTS_RBT_PREFIX>_rbt_foreach_destroy_yielding(
  *                         ERTS_RBT_T *tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
  *                         void *arg,
  *                         <ERTS_RBT_PREFIX>_rbt_yield_state_t *ystate,
- *                         Sint ylimit);
+ *                         Sint reds);
  *         Operate by calling the operator 'op' on each element.
  *         Order is undefined. Each element should be destroyed
  *         by 'op'.
  *
- *         Yield when 'ylimit' elements has been processed. True is
- *         returned when yielding, and false is returned when
- *         the whole tree has been processed.
+ *         Yield when 'reds' reductions has been processed. The 'op'
+ *         function return the number of reductions that each element
+ *         took to process. The number of reductions remaining is returned,
+ *         meaning that if 0 is returned, there are more elements to be
+ *         processed. If a value greater than 0 is returned the foreach has
+ *         ended. The tree should not be modified until all of it has been
+ *         processed.
  *
  *         'arg' is passed as argument to 'op'.
  *
  * - void <ERTS_RBT_PREFIX>_rbt_foreach_small(
  *                         ERTS_RBT_T *tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
  *                         void *arg);
  *         Operate by calling the operator 'op' on each element from
  *         smallest towards larger elements.
@@ -221,7 +228,7 @@
  *
  * - void <ERTS_RBT_PREFIX>_rbt_foreach_large(
  *                         ERTS_RBT_T *tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
  *                         void *arg);
  *         Operate by calling the operator 'op' on each element from
  *         largest towards smaller elements.
@@ -230,40 +237,46 @@
  *
  * - int <ERTS_RBT_PREFIX>_rbt_foreach_small_yielding(
  *                         ERTS_RBT_T *tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
  *                         void *arg,
  *                         <ERTS_RBT_PREFIX>_rbt_yield_state_t *ystate,
- *                         Sint ylimit);
+ *                         Sint reds);
  *         Operate by calling the operator 'op' on each element from
  *         smallest towards larger elements.
  *
- *         Yield when 'ylimit' elements has been processed. True is
- *         returned when yielding, and false is returned when
- *         the whole tree has been processed. The tree should not be
- *         modified until all of it has been processed.
+ *         Yield when 'reds' reductions has been processed. The 'op'
+ *         function return the number of reductions that each element
+ *         took to process. The number of reductions remaining is returned,
+ *         meaning that if 0 is returned, there are more elements to be
+ *         processed. If a value greater than 0 is returned the foreach has
+ *         ended. The tree should not be modified until all of it has been
+ *         processed.
  *
  *         'arg' is passed as argument to 'op'.
  *
  * - int <ERTS_RBT_PREFIX>_rbt_foreach_large_yielding(
  *                         ERTS_RBT_T *tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
  *                         void *arg,
  *                         <ERTS_RBT_PREFIX>_rbt_yield_state_t *ystate,
- *                         Sint ylimit);
+ *                         Sint reds);
  *         Operate by calling the operator 'op' on each element from
  *         largest towards smaller elements.
  *
- *         Yield when 'ylimit' elements has been processed. True is
- *         returned when yielding, and false is returned when
- *         the whole tree has been processed. The tree should not be
- *         modified until all of it has been processed.
+ *         Yield when 'reds' reductions has been processed. The 'op'
+ *         function return the number of reductions that each element
+ *         took to process. The number of reductions remaining is returned,
+ *         meaning that if 0 is returned, there are more elements to be
+ *         processed. If a value greater than 0 is returned the foreach has
+ *         ended. The tree should not be modified until all of it has been
+ *         processed.
  *
  *         'arg' is passed as argument to 'op'.
  *
  * - void <ERTS_RBT_PREFIX>_rbt_foreach_small_destroy(
  *                         ERTS_RBT_T **tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
- *                         void (*destr)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
+ *                         int (*destr)(ERTS_RBT_T *, void *),
  *                         void *arg);
  *         Operate by calling the operator 'op' on each element from
  *         smallest towards larger elements.
@@ -277,8 +290,8 @@
  *
  * - void <ERTS_RBT_PREFIX>_rbt_foreach_large_destroy(
  *                         ERTS_RBT_T **tree,
- *                         void (*op)(ERTS_RBT_T *, void *),
- *                         void (*destr)(ERTS_RBT_T *, void *),
+ *                         int (*op)(ERTS_RBT_T *, void *),
+ *                         int (*destr)(ERTS_RBT_T *, void *),
  *                         void *arg);
  *         Operate by calling the operator 'op' on each element from
  *         largest towards smaller elements.
@@ -292,11 +305,11 @@
  *
  * - int <ERTS_RBT_PREFIX>_rbt_foreach_small_destroy_yielding(
  *                        ERTS_RBT_T **tree,
- *                        void (*op)(ERTS_RBT_T *, void *),
- *                        void (*destr)(ERTS_RBT_T *, void *),
+ *                        int (*op)(ERTS_RBT_T *, void *),
+ *                        int (*destr)(ERTS_RBT_T *, void *),
  *                        void *arg,
  *                        <ERTS_RBT_PREFIX>_rbt_yield_state_t *ystate,
- *                        Sint ylimit);
+ *                        Sint reds);
  *         Operate by calling the operator 'op' on each element from
  *         smallest towards larger elements.
  *
@@ -305,20 +318,23 @@
  *         Note that elements are often destroyed in another order
  *         than the order that the elements are operated on.
  *
- *         Yield when 'ylimit' elements has been processed. True is
- *         returned when yielding, and false is returned when
- *         the whole tree has been processed. The tree should not be
- *         modified until all of it has been processed.
+ *         Yield when 'reds' reductions has been processed. The 'op' and
+ *         'destr' functions return the number of reductions that each element
+ *         took to process. The number of reductions remaining is returned,
+ *         meaning that if 0 is returned, there are more elements to be
+ *         processed. If a value greater than 0 is returned the foreach has
+ *         ended. The tree should not be modified until all of it has been
+ *         processed.
  *
  *         'arg' is passed as argument to 'op' and 'destroy'.
  *
  * - int <ERTS_RBT_PREFIX>_rbt_foreach_large_destroy_yielding(
  *                        ERTS_RBT_T **tree,
- *                        void (*op)(ERTS_RBT_T *, void *),
- *                        void (*destr)(ERTS_RBT_T *, void *),
+ *                        int (*op)(ERTS_RBT_T *, void *),
+ *                        int (*destr)(ERTS_RBT_T *, void *),
  *                        void *arg,
  *                        <ERTS_RBT_PREFIX>_rbt_yield_state_t *ystate,
- *                        Sint ylimit);
+ *                        Sint reds);
  *         Operate by calling the operator 'op' on each element from
  *         largest towards smaller elements.
  *
@@ -327,10 +343,13 @@
  *         Note that elements are often destroyed in another order
  *         than the order that the elements are operated on.
  *
- *         Yield when 'ylimit' elements has been processed. True is
- *         returned when yielding, and false is returned when
- *         the whole tree has been processed. The tree should not be
- *         modified until all of it has been processed.
+ *         Yield when 'reds' reductions has been processed. The 'op' and
+ *         'destr' functions return the number of reductions that each element
+ *         took to process. The number of reductions remaining is returned,
+ *         meaning that if 0 is returned, there are more elements to be
+ *         processed. If a value greater than 0 is returned the foreach has
+ *         ended. The tree should not be modified until all of it has been
+ *         processed.
  *
  *         'arg' is passed as argument to 'op' and 'destroy'.
  *
@@ -447,17 +466,6 @@
 #  define ERTS_RBT_API_INLINE__ ERTS_INLINE
 #endif
 
-#ifndef ERTS_RBT_YIELD_STAT_INITER
-#  define ERTS_RBT_YIELD_STAT_INITER {NULL, 0}
-#endif
-#ifndef ERTS_RBT_YIELD_STAT_INIT
-#  define ERTS_RBT_YIELD_STAT_INIT(YS) \
-    do {                               \
-        (YS)->x = NULL;                \
-        (YS)->up = 0;                  \
-    } while (0)
-#endif
-
 #define ERTS_RBT_CONCAT_MACRO_VALUES___(X, Y) \
     X ## Y
 #define ERTS_RBT_CONCAT_MACRO_VALUES__(X, Y) \
@@ -470,8 +478,38 @@
 typedef struct {
     ERTS_RBT_T *x;
     int up;
+#ifdef DEBUG
+    int debug_red_adj;
+#endif
 } ERTS_RBT_YIELD_STATE_T__;
 
+#define ERTS_RBT_CALLBACK_FOREACH_FUNC(NAME) int (*NAME)(ERTS_RBT_T *, void *, Sint)
+
+#ifndef ERTS_RBT_YIELD_STAT_INITER
+#  ifdef DEBUG
+#    define ERTS_RBT_YIELD_STAT_INITER {NULL, 0, CONTEXT_REDS}
+#  else
+#    define ERTS_RBT_YIELD_STAT_INITER {NULL, 0}
+#  endif
+#endif
+#ifndef ERTS_RBT_YIELD_STAT_INIT
+#  define ERTS_RBT_YIELD_STAT_INIT__(YS)                                \
+    do {                                                                \
+        (YS)->x = NULL;                                                 \
+        (YS)->up = 0;                                                   \
+    } while (0)
+#  ifdef DEBUG
+#    define ERTS_RBT_YIELD_STAT_INIT(YS)        \
+    do {                                        \
+        ERTS_RBT_YIELD_STAT_INIT__(YS);         \
+        (YS)->debug_red_adj = CONTEXT_REDS;     \
+    } while(0)
+#  else
+#    define ERTS_RBT_YIELD_STAT_INIT(YS) ERTS_RBT_YIELD_STAT_INIT__(YS)
+#  endif
+#endif
+
+
 #define ERTS_RBT_FUNC__(Name) \
     ERTS_RBT_CONCAT_MACRO_VALUES__(ERTS_RBT_PREFIX, _rbt_ ## Name)
 
@@ -1302,11 +1340,11 @@ ERTS_RBT_FUNC__(largest)(ERTS_RBT_T *root)
 static ERTS_INLINE int
 ERTS_RBT_FUNC__(foreach_unordered__)(ERTS_RBT_T **root,
 				     int destroying,
-				     void (*op)(ERTS_RBT_T *, void *),
+				     ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
 				     void *arg,
-				     int yielding,
+                                     int yielding,
 				     ERTS_RBT_YIELD_STATE_T__ *ystate,
-				     Sint ylimit)
+				     Sint reds)
 {
     ERTS_RBT_T *c, *p, *x;
 
@@ -1314,13 +1352,17 @@ ERTS_RBT_FUNC__(foreach_unordered__)(ERTS_RBT_T **root,
 
     if (yielding && ystate->x) {
 	x = ystate->x;
+#ifdef DEBUG
+        if (ystate->debug_red_adj > 0)
+            ystate->debug_red_adj -= 100;
+#endif
 	ERTS_RBT_ASSERT(ystate->up);
 	goto restart_up;
     }
     else {
 	x = *root;
 	if (!x)
-	    return 0;
+	    return reds;
 	if (destroying)
 	    *root = NULL;
     }
@@ -1346,10 +1388,10 @@ ERTS_RBT_FUNC__(foreach_unordered__)(ERTS_RBT_T **root,
 #ifdef ERTS_RBT_DEBUG
 	    int cdir;
 #endif
-	    if (yielding && ylimit-- <= 0) {
+	    if (yielding && reds <= 0) {
 		ystate->x = x;
 		ystate->up = 1;
-		return 1;
+		return 0;
 	    }
 
 	restart_up:
@@ -1375,14 +1417,20 @@ ERTS_RBT_FUNC__(foreach_unordered__)(ERTS_RBT_T **root,
 	    }
 #endif
 
-	    (*op)(x, arg);
+            reds -= (*op)(x, arg, reds);
+#ifdef DEBUG
+            if (yielding)
+                reds -= ystate->debug_red_adj;
+#endif
 
 	    if (!p) {
+                /* Done */
 		if (yielding) {
 		    ystate->x = NULL;
 		    ystate->up = 0;
+                    return reds <= 0 ? 1 : reds;
 		}
-		return 0; /* Done */
+                return 1;
 	    }
 
 	    c = ERTS_RBT_GET_RIGHT(p);
@@ -1407,20 +1455,26 @@ static ERTS_INLINE int
 ERTS_RBT_FUNC__(foreach_ordered__)(ERTS_RBT_T **root,
 				   int from_small,
 				   int destroying,
-				   void (*op)(ERTS_RBT_T *, void *),
-				   void (*destroy)(ERTS_RBT_T *, void *),
+                                   ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
+                                   ERTS_RBT_CALLBACK_FOREACH_FUNC(destroy),
 				   void *arg,
-				   int yielding,
+                                   int yielding,
 				   ERTS_RBT_YIELD_STATE_T__ *ystate,
-				   Sint ylimit)
+				   Sint reds)
 {
     ERTS_RBT_T *c, *p, *x;
 
     ERTS_RBT_ASSERT(!yielding || ystate);
     ERTS_RBT_ASSERT(!destroying || destroy);
+    ERTS_RBT_ASSERT(!yielding || yop);
+    ERTS_RBT_ASSERT(yielding || op);
 
     if (yielding && ystate->x) {
 	x = ystate->x;
+#ifdef DEBUG
+        if (ystate->debug_red_adj > 0)
+            ystate->debug_red_adj -= 100;
+#endif
 	if (ystate->up)
 	    goto restart_up;
 	else
@@ -1429,7 +1483,7 @@ ERTS_RBT_FUNC__(foreach_ordered__)(ERTS_RBT_T **root,
     else {
 	x = *root;
 	if (!x)
-	    return 0;
+	    return reds;
 	if (destroying)
 	    *root = NULL;
     }
@@ -1445,12 +1499,16 @@ ERTS_RBT_FUNC__(foreach_ordered__)(ERTS_RBT_T **root,
 		x = c;
 	    }
 
-	    (*op)(x, arg);
+            reds -= (*op)(x, arg, reds);
+#ifdef DEBUG
+            if (yielding)
+                reds -= ystate->debug_red_adj;
+#endif
 
-	    if (yielding && --ylimit <= 0) {
+	    if (yielding && reds <= 0) {
 		ystate->x = x;
 		ystate->up = 0;
-		return 1;
+		return 0;
 	    }
 
 	restart_down:
@@ -1472,12 +1530,16 @@ ERTS_RBT_FUNC__(foreach_ordered__)(ERTS_RBT_T **root,
 				     ? ERTS_RBT_GET_LEFT(p)
 				     : ERTS_RBT_GET_RIGHT(p)) == x);
 
-		    (*op)(p, arg);
+                    reds -= (*op)(p, arg, reds);
+#ifdef DEBUG
+                    if (yielding)
+                        reds -= ystate->debug_red_adj;
+#endif
 
-		    if (yielding && --ylimit <= 0) {
+		    if (yielding && reds <= 0) {
 			ystate->x = x;
 			ystate->up = 1;
-			return 1;
+			return 0;
 		    restart_up:
 			p = ERTS_RBT_GET_PARENT(x);
 		    }
@@ -1510,15 +1572,20 @@ ERTS_RBT_FUNC__(foreach_ordered__)(ERTS_RBT_T **root,
 		}
 #endif
 
-		(*destroy)(x, arg);
+		reds -= (*destroy)(x, arg, reds);
+#ifdef DEBUG
+                if (yielding)
+                    reds -= ystate->debug_red_adj;
+#endif
 	    }
 
 	    if (!p) {
 		if (yielding) {
 		    ystate->x = NULL;
 		    ystate->up = 0;
+                    return reds <= 0 ? 1 : reds;
 		}
-		return 0; /* Done */
+		return 1; /* Done */
 	    }
 	    x = p;
 	}
@@ -1531,7 +1598,7 @@ ERTS_RBT_FUNC__(foreach_ordered__)(ERTS_RBT_T **root,
 
 static ERTS_RBT_API_INLINE__ void
 ERTS_RBT_FUNC__(foreach)(ERTS_RBT_T *root,
-			 void (*op)(ERTS_RBT_T *, void *),
+			 ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
 			 void *arg)
 {
     (void) ERTS_RBT_FUNC__(foreach_unordered__)(&root, 0, op, arg,
@@ -1544,7 +1611,7 @@ ERTS_RBT_FUNC__(foreach)(ERTS_RBT_T *root,
 
 static ERTS_RBT_API_INLINE__ void
 ERTS_RBT_FUNC__(foreach_small)(ERTS_RBT_T *root,
-			       void (*op)(ERTS_RBT_T *, void *),
+			       ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
 			       void *arg)
 {
     (void) ERTS_RBT_FUNC__(foreach_ordered__)(&root, 1, 0,
@@ -1558,7 +1625,7 @@ ERTS_RBT_FUNC__(foreach_small)(ERTS_RBT_T *root,
 
 static ERTS_RBT_API_INLINE__ void
 ERTS_RBT_FUNC__(foreach_large)(ERTS_RBT_T *root,
-			       void (*op)(ERTS_RBT_T *, void *),
+			       ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
 			       void *arg)
 {
     (void) ERTS_RBT_FUNC__(foreach_ordered__)(&root, 0, 0,
@@ -1572,13 +1639,13 @@ ERTS_RBT_FUNC__(foreach_large)(ERTS_RBT_T *root,
 
 static ERTS_RBT_API_INLINE__ int
 ERTS_RBT_FUNC__(foreach_yielding)(ERTS_RBT_T *root,
-				  void (*op)(ERTS_RBT_T *, void *),
+				  ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
 				  void *arg,
 				  ERTS_RBT_YIELD_STATE_T__ *ystate,
-				  Sint ylimit)
+				  Sint reds)
 {
     return ERTS_RBT_FUNC__(foreach_unordered__)(&root, 0, op, arg,
-						1, ystate, ylimit);
+						1, ystate, reds);
 }
 
 #endif /* ERTS_RBT_WANT_FOREACH_YIELDING */
@@ -1587,14 +1654,14 @@ ERTS_RBT_FUNC__(foreach_yielding)(ERTS_RBT_T *root,
 
 static ERTS_RBT_API_INLINE__ int
 ERTS_RBT_FUNC__(foreach_small_yielding)(ERTS_RBT_T *root,
-					void (*op)(ERTS_RBT_T *, void *),
+					ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
 					void *arg,
 					ERTS_RBT_YIELD_STATE_T__ *ystate,
-					Sint ylimit)
+					Sint reds)
 {
     return ERTS_RBT_FUNC__(foreach_ordered__)(&root, 1, 0,
 					      op, NULL, arg,
-					      1, ystate, ylimit);
+					      1, ystate, reds);
 }
 
 #endif /* ERTS_RBT_WANT_FOREACH_SMALL_YIELDING */
@@ -1603,14 +1670,14 @@ ERTS_RBT_FUNC__(foreach_small_yielding)(ERTS_RBT_T *root,
 
 static ERTS_RBT_API_INLINE__ int
 ERTS_RBT_FUNC__(foreach_large_yielding)(ERTS_RBT_T *root,
-					void (*op)(ERTS_RBT_T *, void *),
+					ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
 					void *arg,
 					ERTS_RBT_YIELD_STATE_T__ *ystate,
-					Sint ylimit)
+					Sint reds)
 {
     return ERTS_RBT_FUNC__(foreach_ordered__)(&root, 0, 0,
 					      op, NULL, arg,
-					      1, ystate, ylimit);
+					      1, ystate, reds);
 }
 
 #endif /* ERTS_RBT_WANT_FOREACH_LARGE_YIELDING */
@@ -1619,11 +1686,11 @@ ERTS_RBT_FUNC__(foreach_large_yielding)(ERTS_RBT_T *root,
 
 static ERTS_RBT_API_INLINE__ void
 ERTS_RBT_FUNC__(foreach_destroy)(ERTS_RBT_T **root,
-				 void (*op)(ERTS_RBT_T *, void *),
+				 ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
 				 void *arg)
 {
     (void) ERTS_RBT_FUNC__(foreach_unordered__)(root, 1, op, arg,
-						0, NULL, 0);
+                                                0, NULL, 0);
 }
 
 #endif /* ERTS_RBT_WANT_FOREACH_DESTROY */
@@ -1632,8 +1699,8 @@ ERTS_RBT_FUNC__(foreach_destroy)(ERTS_RBT_T **root,
 
 static ERTS_RBT_API_INLINE__ void
 ERTS_RBT_FUNC__(foreach_small_destroy)(ERTS_RBT_T **root,
-				       void (*op)(ERTS_RBT_T *, void *),
-				       void (*destr)(ERTS_RBT_T *, void *),
+				       ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
+				       ERTS_RBT_CALLBACK_FOREACH_FUNC(destr),
 				       void *arg)
 {
     (void) ERTS_RBT_FUNC__(foreach_ordered__)(root, 1, 1,
@@ -1647,8 +1714,8 @@ ERTS_RBT_FUNC__(foreach_small_destroy)(ERTS_RBT_T **root,
 
 static ERTS_RBT_API_INLINE__ void
 ERTS_RBT_FUNC__(foreach_large_destroy)(ERTS_RBT_T **root,
-				       void (*op)(ERTS_RBT_T *, void *),
-				       void (*destr)(ERTS_RBT_T *, void *),
+				       ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
+				       ERTS_RBT_CALLBACK_FOREACH_FUNC(destr),
 				       void *arg)
 {
     (void) ERTS_RBT_FUNC__(foreach_ordered__)(root, 0, 1,
@@ -1662,13 +1729,13 @@ ERTS_RBT_FUNC__(foreach_large_destroy)(ERTS_RBT_T **root,
 
 static ERTS_RBT_API_INLINE__ int
 ERTS_RBT_FUNC__(foreach_destroy_yielding)(ERTS_RBT_T **root,
-					  void (*op)(ERTS_RBT_T *, void *),
+					  ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
 					  void *arg,
 					  ERTS_RBT_YIELD_STATE_T__ *ystate,
-					  Sint ylimit)
+					  Sint reds)
 {
     return ERTS_RBT_FUNC__(foreach_unordered__)(root, 1, op, arg,
-						1, ystate, ylimit);
+						1, ystate, reds);
 }
 
 #endif /* ERTS_RBT_WANT_FOREACH_DESTROY_YIELDING */
@@ -1677,15 +1744,15 @@ ERTS_RBT_FUNC__(foreach_destroy_yielding)(ERTS_RBT_T **root,
 
 static ERTS_RBT_API_INLINE__ int
 ERTS_RBT_FUNC__(foreach_small_destroy_yielding)(ERTS_RBT_T **root,
-						void (*op)(ERTS_RBT_T *, void *),
-						void (*destr)(ERTS_RBT_T *, void *),
+						ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
+						ERTS_RBT_CALLBACK_FOREACH_FUNC(destr),
 						void *arg,
 						ERTS_RBT_YIELD_STATE_T__ *ystate,
-						Sint ylimit)
+						Sint reds)
 {
     return ERTS_RBT_FUNC__(foreach_ordered__)(root, 1, 1,
 					      op, destr, arg,
-					      1, ystate, ylimit);
+					      1, ystate, reds);
 }
 
 #endif /* ERTS_RBT_WANT_FOREACH_SMALL_DESTROY_YIELDING */
@@ -1694,15 +1761,15 @@ ERTS_RBT_FUNC__(foreach_small_destroy_yielding)(ERTS_RBT_T **root,
 
 static ERTS_RBT_API_INLINE__ int
 ERTS_RBT_FUNC__(foreach_large_destroy_yielding)(ERTS_RBT_T **root,
-						void (*op)(ERTS_RBT_T *, void *),
-						void (*destr)(ERTS_RBT_T *, void *),
+						ERTS_RBT_CALLBACK_FOREACH_FUNC(op),
+						ERTS_RBT_CALLBACK_FOREACH_FUNC(destr),
 						void *arg,
 						ERTS_RBT_YIELD_STATE_T__ *ystate,
-						Sint ylimit)
+						Sint reds)
 {
     return ERTS_RBT_FUNC__(foreach_ordered__)(root, 0, 1,
 					      op, destr, arg,
-					      1, ystate, ylimit);
+					      1, ystate, reds);
 }
 
 #endif /* ERTS_RBT_WANT_FOREACH_LARGE_DESTROY_YIELDING */
@@ -1855,6 +1922,7 @@ ERTS_RBT_FUNC__(hdbg_check_tree)(ERTS_RBT_T *root, ERTS_RBT_T *n)
 #ifdef ERTS_RBT_UNDEF
 #  undef ERTS_RBT_PREFIX
 #  undef ERTS_RBT_T
+#  undef ERTS_RBT_CALLBACK_FOREACH_FUNC
 #  undef ERTS_RBT_KEY_T
 #  undef ERTS_RBT_FLAGS_T
 #  undef ERTS_RBT_INIT_EMPTY_TNODE
diff --git a/erts/emulator/beam/erl_sched_spec_pre_alloc.h b/erts/emulator/beam/erl_sched_spec_pre_alloc.h
index 74cc966cbe..6f715ae80d 100644
--- a/erts/emulator/beam/erl_sched_spec_pre_alloc.h
+++ b/erts/emulator/beam/erl_sched_spec_pre_alloc.h
@@ -49,7 +49,7 @@ do {									\
 #endif
 
 #ifdef DEBUG
-extern Uint erts_no_schedulers;
+extern Uint ERTS_WRITE_UNLIKELY(erts_no_schedulers);
 #endif
 
 #define ERTS_SSPA_FORCE_THR_CHECK_PROGRESS 10
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c
index 29c698e34f..d26ea19494 100644
--- a/erts/emulator/beam/erl_time_sup.c
+++ b/erts/emulator/beam/erl_time_sup.c
@@ -1911,8 +1911,8 @@ typedef struct {
     ErtsTimeOffsetMonitorInfo *to_mon_info;
 } ErtsTimeOffsetMonitorContext;
 
-static void
-save_time_offset_monitor(ErtsMonitor *mon, void *vcntxt)
+static int
+save_time_offset_monitor(ErtsMonitor *mon, void *vcntxt, Sint reds)
 {
     ErtsTimeOffsetMonitorContext *cntxt;
     ErtsMonitorData *mdp = erts_monitor_to_data(mon);
@@ -1935,7 +1935,7 @@ save_time_offset_monitor(ErtsMonitor *mon, void *vcntxt)
 
     cntxt->to_mon_info[mix].ref
 	= make_internal_ref(&cntxt->to_mon_info[mix].heap[0]);
-
+    return 1;
 }
 
 static void
diff --git a/erts/emulator/beam/erl_trace.c b/erts/emulator/beam/erl_trace.c
index 2350d4c02f..f6f177887c 100644
--- a/erts/emulator/beam/erl_trace.c
+++ b/erts/emulator/beam/erl_trace.c
@@ -72,6 +72,7 @@ static ErtsTracer default_port_tracer;
 
 static Eterm system_monitor;
 static Eterm system_profile;
+static erts_atomic_t system_logger;
 
 #ifdef HAVE_ERTS_NOW_CPU
 int erts_cpu_timestamp;
@@ -340,6 +341,7 @@ void erts_init_trace(void) {
     default_port_trace_flags = F_INITIAL_TRACE_FLAGS;
     default_port_tracer = erts_tracer_nil;
     system_seq_tracer = erts_tracer_nil;
+    erts_atomic_init_nob(&system_logger, am_logger);
     init_sys_msg_dispatcher();
     init_tracer_nif();
 }
@@ -633,9 +635,11 @@ write_sys_msg_to_port(Eterm unused_to,
 		      Eterm message) {
     byte *buffer;
     byte *ptr;
-    unsigned size;
+    Uint size;
+
+    if (erts_encode_ext_size(message, &size) != ERTS_EXT_SZ_OK)
+	erts_exit(ERTS_ERROR_EXIT, "Internal error: System limit\n");
 
-    size = erts_encode_ext_size(message);
     buffer = (byte *) erts_alloc(ERTS_ALC_T_TMP, size);
 
     ptr = buffer;
@@ -709,7 +713,9 @@ trace_sched(Process *p, ErtsProcLocks locks, Eterm what)
     trace_sched_aux(p, locks, what);
 }
 
-/* Send {trace_ts, Pid, Send, Msg, DestPid, Timestamp}
+/* Send {trace_ts, Pid, Send, Msg, DestPid, PamResult, Timestamp}
+ * or   {trace_ts, Pid, Send, Msg, DestPid, Timestamp}
+ * or   {trace, Pid, Send, Msg, DestPid, PamResult}
  * or   {trace, Pid, Send, Msg, DestPid}
  *
  * where 'Send' is 'send' or 'send_to_non_existing_process'.
@@ -769,7 +775,9 @@ trace_send(Process *p, Eterm to, Eterm msg)
     erts_match_set_release_result_trace(p, pam_result);
 }
 
-/* Send {trace_ts, Pid, receive, Msg, Timestamp}
+/* Send {trace_ts, Pid, receive, Msg, PamResult, Timestamp}
+ * or   {trace_ts, Pid, receive, Msg, Timestamp}
+ * or   {trace, Pid, receive, Msg, PamResult}
  * or   {trace, Pid, receive, Msg}
  */
 void
@@ -2027,10 +2035,24 @@ enqueue_sys_msg(enum ErtsSysMsgType type,
     erts_mtx_unlock(&smq_mtx);
 }
 
+Eterm
+erts_get_system_logger(void)
+{
+    return (Eterm)erts_atomic_read_nob(&system_logger);
+}
+
+Eterm
+erts_set_system_logger(Eterm logger)
+{
+    if (logger != am_logger && logger != am_undefined && !is_internal_pid(logger))
+        return THE_NON_VALUE;
+    return (Eterm)erts_atomic_xchg_nob(&system_logger, logger);
+}
+
 void
 erts_queue_error_logger_message(Eterm from, Eterm msg, ErlHeapFragment *bp)
 {
-    enqueue_sys_msg(SYS_MSG_TYPE_ERRLGR, from, am_logger, msg, bp);
+    enqueue_sys_msg(SYS_MSG_TYPE_ERRLGR, from, erts_get_system_logger(), msg, bp);
 }
 
 void
@@ -2172,11 +2194,12 @@ sys_msg_dispatcher_wait(void *vwait_p)
     erts_mtx_unlock(&smq_mtx);
 }
 
+static ErtsSysMsgQ *local_sys_message_queue = NULL;
+
 static void *
 sys_msg_dispatcher_func(void *unused)
 {
     ErtsThrPrgrCallbacks callbacks;
-    ErtsSysMsgQ *local_sys_message_queue = NULL;
     ErtsThrPrgrData *tpd;
     int wait = 0;
 
@@ -2184,6 +2207,8 @@ sys_msg_dispatcher_func(void *unused)
     erts_lc_set_thread_name("system message dispatcher");
 #endif
 
+    local_sys_message_queue = NULL;
+
     callbacks.arg = (void *) &wait;
     callbacks.wakeup = sys_msg_dispatcher_wakeup;
     callbacks.prepare_wait = sys_msg_dispatcher_prep_wait;
@@ -2240,6 +2265,8 @@ sys_msg_dispatcher_func(void *unused)
 	    Process *proc = NULL;
 	    Port *port = NULL;
 
+            ASSERT(is_value(smqp->msg));
+
 	    if (erts_thr_progress_update(tpd))
 		erts_thr_progress_leader_update(tpd);
 
@@ -2271,7 +2298,7 @@ sys_msg_dispatcher_func(void *unused)
 		}
 		break;
 	    case SYS_MSG_TYPE_ERRLGR:
-		receiver = am_logger;
+		receiver = smqp->to;
 		break;
 	    default:
 		receiver = NIL;
@@ -2285,8 +2312,15 @@ sys_msg_dispatcher_func(void *unused)
 	    if (is_internal_pid(receiver)) {
 		proc = erts_pid2proc(NULL, 0, receiver, proc_locks);
 		if (!proc) {
-		    /* Bad tracer */
-		    goto failure;
+                    if (smqp->type == SYS_MSG_TYPE_ERRLGR) {
+                        /* Bad logger process, send to kernel 'logger' process */
+                        erts_set_system_logger(am_logger);
+                        receiver = erts_get_system_logger();
+                        goto logger;
+                    } else {
+                        /* Bad tracer */
+                        goto failure;
+                    }
 		}
 		else {
 		    ErtsMessage *mp;
@@ -2299,9 +2333,9 @@ sys_msg_dispatcher_func(void *unused)
 #endif
 		    erts_proc_unlock(proc, proc_locks);
 		}
-	    }
-	    else if (receiver == am_logger) {
-		proc = erts_whereis_process(NULL,0,receiver,proc_locks,0);
+	    } else if (receiver == am_logger) {
+            logger:
+		proc = erts_whereis_process(NULL,0,am_logger,proc_locks,0);
 		if (!proc)
 		    goto failure;
 		else if (smqp->from == proc->common.id)
@@ -2309,7 +2343,10 @@ sys_msg_dispatcher_func(void *unused)
 		else
 		    goto queue_proc_msg;
 	    }
-	    else if (is_internal_port(receiver)) {
+            else if (receiver == am_undefined) {
+                goto drop_sys_msg;
+	    }
+            else if (is_internal_port(receiver)) {
 		port = erts_thr_id2port_sflgs(receiver,
 					      ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
 		if (!port)
@@ -2342,6 +2379,7 @@ sys_msg_dispatcher_func(void *unused)
 		erts_fprintf(stderr, "dropped\n");
 #endif
 	    }
+            smqp->msg = THE_NON_VALUE;
 	}
     }
 
@@ -2349,32 +2387,38 @@ sys_msg_dispatcher_func(void *unused)
 }
 
 void
-erts_foreach_sys_msg_in_q(void (*func)(Eterm,
-				       Eterm,
-				       Eterm,
-				       ErlHeapFragment *))
+erts_debug_foreach_sys_msg_in_q(void (*func)(Eterm,
+                                             Eterm,
+                                             Eterm,
+                                             ErlHeapFragment *))
 {
-    ErtsSysMsgQ *sm;
-    erts_mtx_lock(&smq_mtx);
-    for (sm = sys_message_queue; sm; sm = sm->next) {
-	Eterm to;
-	switch (sm->type) {
-	case SYS_MSG_TYPE_SYSMON:
-	    to = erts_get_system_monitor();
-	    break;
-	case SYS_MSG_TYPE_SYSPROF:
-	    to = erts_get_system_profile();
-	    break;
-	case SYS_MSG_TYPE_ERRLGR:
-	    to = am_logger;
-	    break;
-	default:
-	    to = NIL;
-	    break;
-	}
-	(*func)(sm->from, to, sm->msg, sm->bp);
+    ErtsSysMsgQ *smq[] = {sys_message_queue, local_sys_message_queue};
+    int i;
+
+    ERTS_LC_ASSERT(erts_thr_progress_is_blocking());
+
+    for (i = 0; i < sizeof(smq)/sizeof(smq[0]); i++) {
+        ErtsSysMsgQ *sm;
+        for (sm = smq[i]; sm; sm = sm->next) {
+            Eterm to;
+            switch (sm->type) {
+            case SYS_MSG_TYPE_SYSMON:
+                to = erts_get_system_monitor();
+                break;
+            case SYS_MSG_TYPE_SYSPROF:
+                to = erts_get_system_profile();
+                break;
+            case SYS_MSG_TYPE_ERRLGR:
+                to = erts_get_system_logger();
+                break;
+            default:
+                to = NIL;
+                break;
+            }
+            if (is_value(sm->msg))
+                (*func)(sm->from, to, sm->msg, sm->bp);
+        }
     }
-    erts_mtx_unlock(&smq_mtx);
 }
 
 
diff --git a/erts/emulator/beam/erl_trace.h b/erts/emulator/beam/erl_trace.h
index bccf31606e..af38ef52db 100644
--- a/erts/emulator/beam/erl_trace.h
+++ b/erts/emulator/beam/erl_trace.h
@@ -90,10 +90,12 @@ int erts_is_tracer_valid(Process* p);
 void erts_check_my_tracer_proc(Process *);
 void erts_block_sys_msg_dispatcher(void);
 void erts_release_sys_msg_dispatcher(void);
-void erts_foreach_sys_msg_in_q(void (*func)(Eterm,
-					    Eterm,
-					    Eterm,
-					    ErlHeapFragment *));
+void erts_debug_foreach_sys_msg_in_q(void (*func)(Eterm,
+                                                  Eterm,
+                                                  Eterm,
+                                                  ErlHeapFragment *));
+Eterm erts_set_system_logger(Eterm);
+Eterm erts_get_system_logger(void);
 void erts_queue_error_logger_message(Eterm, Eterm, ErlHeapFragment *);
 void erts_send_sys_msg_proc(Eterm, Eterm, Eterm, ErlHeapFragment *);
 
diff --git a/erts/emulator/beam/erl_unicode.c b/erts/emulator/beam/erl_unicode.c
index d225916ac5..1d6869a7cd 100644
--- a/erts/emulator/beam/erl_unicode.c
+++ b/erts/emulator/beam/erl_unicode.c
@@ -1358,11 +1358,9 @@ Uint erts_atom_to_string_length(Eterm atom)
     else {
         byte* err_pos;
         Uint num_chars;
-#ifdef DEBUG
         int ares =
-#endif
             erts_analyze_utf8(ap->name, ap->len, &err_pos, &num_chars, NULL);
-        ASSERT(ares == ERTS_UTF8_OK);
+        ASSERT(ares == ERTS_UTF8_OK); (void)ares;
 
         return num_chars;
     }
diff --git a/erts/emulator/beam/erl_utils.h b/erts/emulator/beam/erl_utils.h
index 880febba8b..430ac305c5 100644
--- a/erts/emulator/beam/erl_utils.h
+++ b/erts/emulator/beam/erl_utils.h
@@ -69,7 +69,6 @@ int erts_fit_in_bits_int32(Sint32);
 int erts_fit_in_bits_uint(Uint);
 Sint erts_list_length(Eterm);
 int erts_is_builtin(Eterm, Eterm, int);
-Uint32 block_hash(byte *, unsigned, Uint32);
 Uint32 make_hash2(Eterm);
 Uint32 make_hash(Eterm);
 Uint32 make_internal_hash(Eterm, Uint32 salt);
diff --git a/erts/emulator/beam/erl_vm.h b/erts/emulator/beam/erl_vm.h
index 4089fac48e..e623148587 100644
--- a/erts/emulator/beam/erl_vm.h
+++ b/erts/emulator/beam/erl_vm.h
@@ -41,8 +41,8 @@
 #define MAX_REG 1024            /* Max number of x(N) registers used */
 
 /*
- * The new arithmetic operations need some extra X registers in the register array.
- * so does the gc_bif's (i_gc_bif3 need 3 extra).
+ * The new trapping length/1 implementation need 3 extra registers in the
+ * register array.
  */
 #define ERTS_X_REGS_ALLOCATED (MAX_REG+3)
 
@@ -67,9 +67,10 @@
                  (unsigned long)HEAP_TOP(p),(sz),__FILE__,__LINE__)),   \
  */
 #  ifdef CHECK_FOR_HOLES
-#    define INIT_HEAP_MEM(p,sz) erts_set_hole_marker(HEAP_TOP(p), (sz))
+Eterm* erts_set_hole_marker(Eterm* ptr, Uint sz);
+#    define INIT_HEAP_MEM(p,sz) erts_set_hole_marker(p, (sz))
 #  else
-#    define INIT_HEAP_MEM(p,sz) sys_memset(HEAP_TOP(p),0x01,(sz)*sizeof(Eterm*))
+#    define INIT_HEAP_MEM(p,sz) sys_memset(p,0x01,(sz)*sizeof(Eterm*))
 #  endif
 #else
 #  define INIT_HEAP_MEM(p,sz) ((void)0)
@@ -91,7 +92,7 @@
      ErtsHAllocLockCheck(p),					      \
      (IS_FORCE_HEAP_FRAGS || (((HEAP_LIMIT(p) - HEAP_TOP(p)) < (sz))) \
       ? erts_heap_alloc((p),(sz),(xtra))                              \
-      : (INIT_HEAP_MEM(p,sz),		                              \
+      : (INIT_HEAP_MEM(HEAP_TOP(p),sz),                               \
          HEAP_TOP(p) = HEAP_TOP(p) + (sz), HEAP_TOP(p) - (sz))))
 
 #define HAlloc(P, SZ) HAllocX(P,SZ,0)
@@ -146,6 +147,21 @@
       (HEAP_TOP(p) = HEAP_TOP(p) + (sz), HEAP_TOP(p) - (sz))))
 #endif
 
+/*
+ * Always allocate in a heap fragment, never on the heap.
+ */
+#if defined(VALGRIND)
+/* Running under valgrind, allocate exactly as much as needed.*/
+#  define HeapFragOnlyAlloc(p, sz)              \
+  (ASSERT((sz) >= 0),                           \
+   ErtsHAllocLockCheck(p),                      \
+   erts_heap_alloc((p),(sz),0))
+#else
+#  define HeapFragOnlyAlloc(p, sz)              \
+  (ASSERT((sz) >= 0),                           \
+   ErtsHAllocLockCheck(p),                      \
+   erts_heap_alloc((p),(sz),512))
+#endif
 
 /*
  * Description for each instruction (defined here because the name and
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index 9a66e491f3..ce61cdf040 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -102,7 +102,7 @@ static byte* enc_term(ErtsAtomCacheMap *, Eterm, byte*, Uint32, struct erl_off_h
 struct TTBEncodeContext_;
 static int enc_term_int(struct TTBEncodeContext_*,ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags,
 			struct erl_off_heap_header** off_heap, Sint *reds, byte **res);
-static Uint is_external_string(Eterm obj, int* p_is_string);
+static int is_external_string(Eterm obj, Uint* lenp);
 static byte* enc_atom(ErtsAtomCacheMap *, Eterm, byte*, Uint32);
 static byte* enc_pid(ErtsAtomCacheMap *, Eterm, byte*, Uint32);
 struct B2TContext_t;
@@ -112,13 +112,13 @@ static byte* dec_pid(ErtsDistExternal *, ErtsHeapFactory*, byte*, Eterm*, byte t
 static Sint decoded_size(byte *ep, byte* endp, int internal_tags, struct B2TContext_t*);
 static BIF_RETTYPE term_to_binary_trap_1(BIF_ALIST_1);
 
-static Eterm erts_term_to_binary_int(Process* p, Eterm Term, int level, Uint flags, 
-				     Binary *context_b);
+static Eterm erts_term_to_binary_int(Process* p, Eterm Term, Eterm opts, int level,
+                                     Uint flags, Binary *context_b);
 
 static Uint encode_size_struct2(ErtsAtomCacheMap *, Eterm, unsigned);
 struct TTBSizeContext_;
-static int encode_size_struct_int(struct TTBSizeContext_*, ErtsAtomCacheMap *acmp, Eterm obj,
-				  unsigned dflags, Sint *reds, Uint *res);
+static ErtsExtSzRes encode_size_struct_int(struct TTBSizeContext_*, ErtsAtomCacheMap *acmp,
+                                           Eterm obj, unsigned dflags, Sint *reds, Uint *res);
 
 static Export binary_to_term_trap_export;
 static BIF_RETTYPE binary_to_term_trap_1(BIF_ALIST_1);
@@ -262,19 +262,12 @@ erts_finalize_atom_cache_map(ErtsAtomCacheMap *acmp, Uint32 dflags)
     if (acmp) {
 	int long_atoms = 0; /* !0 if one or more atoms are longer than 255. */
 	int i;
-	int sz;
-	int fix_sz
-	    = 1 /* VERSION_MAGIC */
-	    + 1 /* DIST_HEADER */
-	    + 1 /* dist header flags */
-	    + 1 /* number of internal cache entries */
-	    ;
+	int sz = 0;
 	int min_sz;
         ASSERT(dflags & DFLAG_UTF8_ATOMS);
 	ASSERT(acmp->hdr_sz < 0);
 	/* Make sure cache update instructions fit */
-	min_sz = fix_sz+(2+4)*acmp->sz;
-	sz = fix_sz;
+	min_sz = (2+4)*acmp->sz;
 	for (i = 0; i < acmp->sz; i++) {
 	    Atom *a;
 	    Eterm atom;
@@ -302,17 +295,28 @@ erts_finalize_atom_cache_map(ErtsAtomCacheMap *acmp, Uint32 dflags)
 }
 
 Uint
-erts_encode_ext_dist_header_size(ErtsAtomCacheMap *acmp)
+erts_encode_ext_dist_header_size(ErtsAtomCacheMap *acmp, Uint fragments)
 {
     if (!acmp)
 	return 0;
     else {
+        int fix_sz
+            = 1 /* VERSION_MAGIC */
+            + 1 /* DIST_HEADER */
+            + 1 /* dist header flags */
+            + 1 /* number of internal cache entries */
+            ;
 	ASSERT(acmp->hdr_sz >= 0);
-	return acmp->hdr_sz;
+        if (fragments > 1)
+            fix_sz += 8 /* sequence id */
+                + 8 /* number of fragments */
+                ;
+        return fix_sz + acmp->hdr_sz;
     }
 }
 
-byte *erts_encode_ext_dist_header_setup(byte *ctl_ext, ErtsAtomCacheMap *acmp)
+byte *erts_encode_ext_dist_header_setup(byte *ctl_ext, ErtsAtomCacheMap *acmp,
+                                        Uint fragments, Eterm from)
 {
     /* Maximum number of atom must be less than the maximum of a 32 bits
        unsigned integer. Check is done in erl_init.c, erl_start function. */
@@ -346,12 +350,37 @@ byte *erts_encode_ext_dist_header_setup(byte *ctl_ext, ErtsAtomCacheMap *acmp)
 	put_int8(acmp->sz, ep);
 	--ep;
 	put_int8(dist_hdr_flags, ep);
-	*--ep = DIST_HEADER;
-	*--ep = VERSION_MAGIC;
+        if (fragments > 1) {
+            ASSERT(is_pid(from));
+            ep -= 8;
+            put_int64(fragments, ep);
+            ep -= 8;
+            put_int64(from, ep);
+            *--ep = DIST_FRAG_HEADER;
+        } else {
+            *--ep = DIST_HEADER;
+        }
+        *--ep = VERSION_MAGIC;
 	return ep;
     }
 }
 
+byte *erts_encode_ext_dist_header_fragment(byte **hdrpp,
+                                           Uint fragment,
+                                           Eterm from)
+{
+    byte *ep = *hdrpp, *start = ep;
+    ASSERT(is_pid(from));
+    *ep++ = VERSION_MAGIC;
+    *ep++ = DIST_FRAG_CONT;
+    put_int64(from, ep);
+    ep += 8;
+    put_int64(fragment, ep);
+    ep += 8;
+    *hdrpp = ep;
+    return start;
+}
+
 
 #define PASS_THROUGH 'p'
 
@@ -365,7 +394,8 @@ Sint erts_encode_ext_dist_header_finalize(ErtsDistOutputBuf* ob,
     int ci, sz;
     byte dist_hdr_flags;
     int long_atoms;
-    register byte *ep = ob->extp;
+    Uint64 seq_id = 0, frag_id = 0;
+    register byte *ep = ob->hdrp ? ob->hdrp : ob->extp;
     ASSERT(dflags & DFLAG_UTF8_ATOMS);
 
     /*
@@ -416,7 +446,7 @@ Sint erts_encode_ext_dist_header_finalize(ErtsDistOutputBuf* ob,
         }
         goto done;
     }
-    else if (ep[1] != DIST_HEADER) {
+    else if (ep[1] != DIST_HEADER && ep[1] != DIST_FRAG_HEADER && ep[1] != DIST_FRAG_CONT) {
         ASSERT(ep[1] == SMALL_TUPLE_EXT || ep[1] == LARGE_TUPLE_EXT);
         ASSERT(!(dflags & DFLAG_DIST_HDR_ATOM_CACHE));
         /* Node without atom cache, 'pass through' needed */
@@ -424,6 +454,17 @@ Sint erts_encode_ext_dist_header_finalize(ErtsDistOutputBuf* ob,
         goto done;
     }
 
+    if (ep[1] == DIST_FRAG_CONT) {
+        ep = ob->extp;
+        goto done;
+    } else if (ep[1] == DIST_FRAG_HEADER) {
+        /* skip the seq id and frag id */
+        seq_id = get_int64(&ep[2]);
+        ep += 8;
+        frag_id = get_int64(&ep[2]);
+        ep += 8;
+    }
+
     dist_hdr_flags = ep[2];
     long_atoms = ERTS_DIST_HDR_LONG_ATOMS_FLG & ((int) dist_hdr_flags);
 
@@ -546,57 +587,66 @@ Sint erts_encode_ext_dist_header_finalize(ErtsDistOutputBuf* ob,
     }
     --ep;
     put_int8(ci, ep);
-    *--ep = DIST_HEADER;
+    if (seq_id) {
+        ep -= 8;
+        put_int64(frag_id, ep);
+        ep -= 8;
+        put_int64(seq_id, ep);
+        *--ep = DIST_FRAG_HEADER;
+    } else {
+        *--ep = DIST_HEADER;
+    }
     *--ep = VERSION_MAGIC;
 done:
     ob->extp = ep;
-    ASSERT(&ob->data[0] <= ob->extp && ob->extp < ob->ext_endp);
+    ASSERT((byte*)ob->bin->orig_bytes <= ob->extp && ob->extp < ob->ext_endp);
     return reds < 0 ? 0 : reds;
 }
 
-int erts_encode_dist_ext_size(Eterm term, Uint32 flags, ErtsAtomCacheMap *acmp,
-			      Uint* szp)
+ErtsExtSzRes
+erts_encode_dist_ext_size(Eterm term, Uint32 flags, ErtsAtomCacheMap *acmp, Uint* szp)
 {
     Uint sz;
-    if (encode_size_struct_int(NULL, acmp, term, flags, NULL, &sz)) {
-	return -1;
-    } else {
+    ErtsExtSzRes res = encode_size_struct_int(NULL, acmp, term, flags, NULL, &sz);
+    if (res == ERTS_EXT_SZ_OK) {
 #ifndef ERTS_DEBUG_USE_DIST_SEP
 	if (!(flags & (DFLAG_DIST_HDR_ATOM_CACHE | DFLAG_NO_MAGIC)))
 #endif
 	    sz++ /* VERSION_MAGIC */;
 
 	*szp += sz;
-	return 0;
     }
+    return res;
 }
 
-int erts_encode_dist_ext_size_int(Eterm term, struct erts_dsig_send_context* ctx, Uint* szp)
+ErtsExtSzRes
+erts_encode_dist_ext_size_ctx(Eterm term, ErtsDSigSendContext *ctx, Uint* szp)
 {
     Uint sz;
-    if (encode_size_struct_int(&ctx->u.sc, ctx->acmp, term, ctx->flags, &ctx->reds, &sz)) {
-	return -1;
-    } else {
+    ErtsExtSzRes res = encode_size_struct_int(&ctx->u.sc, ctx->acmp, term,
+                                              ctx->flags, &ctx->reds, &sz);
+    if (res == ERTS_EXT_SZ_OK) {
 #ifndef ERTS_DEBUG_USE_DIST_SEP
 	if (!(ctx->flags & (DFLAG_DIST_HDR_ATOM_CACHE | DFLAG_NO_MAGIC)))
 #endif
 	    sz++ /* VERSION_MAGIC */;
 
 	*szp += sz;
-	return 0;
     }
+    return res;
 }
 
-Uint erts_encode_ext_size(Eterm term)
+ErtsExtSzRes erts_encode_ext_size_2(Eterm term, unsigned dflags, Uint *szp)
 {
-    return encode_size_struct2(NULL, term, TERM_TO_BINARY_DFLAGS)
-	+ 1 /* VERSION_MAGIC */;
+    ErtsExtSzRes res = encode_size_struct_int(NULL, NULL, term, dflags,
+                                              NULL, szp);
+    (*szp)++ /* VERSION_MAGIC */;
+    return res;
 }
 
-Uint erts_encode_ext_size_2(Eterm term, unsigned dflags)
+ErtsExtSzRes erts_encode_ext_size(Eterm term, Uint *szp)
 {
-    return encode_size_struct2(NULL, term, dflags)
-        + 1 /* VERSION_MAGIC */;
+    return erts_encode_ext_size_2(term, TERM_TO_BINARY_DFLAGS, szp);
 }
 
 Uint erts_encode_ext_size_ets(Eterm term)
@@ -635,56 +685,110 @@ byte* erts_encode_ext_ets(Eterm term, byte *ep, struct erl_off_heap_header** off
 		    off_heap);
 }
 
-ErtsDistExternal *
-erts_make_dist_ext_copy(ErtsDistExternal *edep, Uint xsize)
+
+static Uint
+dist_ext_size(ErtsDistExternal *edep)
 {
-    size_t align_sz;
-    size_t dist_ext_sz;
-    size_t ext_sz;
-    byte *ep;
-    ErtsDistExternal *new_edep;
+    Uint sz = sizeof(ErtsDistExternal);
 
-    dist_ext_sz = ERTS_DIST_EXT_SIZE(edep);
-    ASSERT(edep->ext_endp && edep->extp);
-    ASSERT(edep->ext_endp >= edep->extp);
-    ext_sz = edep->ext_endp - edep->extp;
+    ASSERT(edep->data->ext_endp && edep->data->extp);
+    ASSERT(edep->data->ext_endp >= edep->data->extp);
 
-    align_sz = ERTS_EXTRA_DATA_ALIGN_SZ(dist_ext_sz + ext_sz);
+    if (edep->flags & ERTS_DIST_EXT_ATOM_TRANS_TAB) {
+        ASSERT(0 <= edep->attab.size \
+               && edep->attab.size <= ERTS_ATOM_CACHE_SIZE);
+        sz -= sizeof(Eterm)*(ERTS_ATOM_CACHE_SIZE - edep->attab.size);
+    } else {
+        sz -= sizeof(ErtsAtomTranslationTable);
+    }
+    ASSERT(sz % 4 == 0);
+    return sz;
+}
 
-    new_edep = erts_alloc(ERTS_ALC_T_EXT_TERM_DATA,
-			  dist_ext_sz + ext_sz + align_sz + xsize);
+Uint
+erts_dist_ext_size(ErtsDistExternal *edep)
+{
+    Uint sz = dist_ext_size(edep);
+    sz += 4;  /* may need to pad to 8-byte-align ErtsDistExternalData */
+    sz += edep->data[0].frag_id * sizeof(ErtsDistExternalData);
+    return sz;
+}
+
+Uint
+erts_dist_ext_data_size(ErtsDistExternal *edep)
+{
+    Uint sz = 0, i;
+    for (i = 0; i < edep->data->frag_id; i++)
+        sz += edep->data[i].ext_endp - edep->data[i].extp;
+    return sz;
+}
+
+void
+erts_dist_ext_frag(ErtsDistExternalData *ede_datap, ErtsDistExternal *edep)
+{
+    ErtsDistExternalData *new_ede_datap = &edep->data[edep->data->frag_id - ede_datap->frag_id];
+    sys_memcpy(new_ede_datap, ede_datap, sizeof(ErtsDistExternalData));
+
+    /* If the data is not backed by a binary, we create one here to keep
+       things simple. Only custom distribution drivers should use lists. */
+    if (new_ede_datap->binp == NULL) {
+        size_t ext_sz = ede_datap->ext_endp - ede_datap->extp;
+        new_ede_datap->binp = erts_bin_nrml_alloc(ext_sz);
+        sys_memcpy(new_ede_datap->binp->orig_bytes, (void *) ede_datap->extp, ext_sz);
+        new_ede_datap->extp = (byte*)new_ede_datap->binp->orig_bytes;
+        new_ede_datap->ext_endp = (byte*)new_ede_datap->binp->orig_bytes + ext_sz;
+    } else {
+        erts_refc_inc(&new_ede_datap->binp->intern.refc, 2);
+    }
+}
+
+void
+erts_make_dist_ext_copy(ErtsDistExternal *edep, ErtsDistExternal *new_edep)
+{
+    size_t dist_ext_sz = dist_ext_size(edep);
+    byte *ep;
 
     ep = (byte *) new_edep;
     sys_memcpy((void *) ep, (void *) edep, dist_ext_sz);
+    erts_ref_dist_entry(new_edep->dep);
+
     ep += dist_ext_sz;
-    if (new_edep->dep)
-        erts_ref_dist_entry(new_edep->dep);
-    new_edep->extp = ep;
-    new_edep->ext_endp = ep + ext_sz;
-    new_edep->heap_size = -1;
-    sys_memcpy((void *) ep, (void *) edep->extp, ext_sz);
-    return new_edep;
+    ep += (UWord)ep & 4; /* 8-byte alignment for ErtsDistExternalData */
+    ASSERT((UWord)ep % 8 == 0);
+
+    new_edep->data = (ErtsDistExternalData*)ep;
+    sys_memzero(new_edep->data, sizeof(ErtsDistExternalData) * edep->data->frag_id);
+    new_edep->data->frag_id = edep->data->frag_id;
+    erts_dist_ext_frag(edep->data, new_edep);
 }
 
-int
+void
+erts_free_dist_ext_copy(ErtsDistExternal *edep)
+{
+    int i;
+    erts_deref_dist_entry(edep->dep);
+    for (i = 0; i < edep->data->frag_id; i++)
+        if (edep->data[i].binp)
+            erts_bin_release(edep->data[i].binp);
+}
+
+ErtsPrepDistExtRes
 erts_prepare_dist_ext(ErtsDistExternal *edep,
 		      byte *ext,
 		      Uint size,
+                      Binary *binp,
 		      DistEntry *dep,
                       Uint32 conn_id,
 		      ErtsAtomCache *cache)
 {
     register byte *ep;
 
-    edep->heap_size = -1;
-    edep->flags = 0;
-    edep->dep = dep;
-
     ASSERT(dep);
     erts_de_rlock(dep);
 
     ASSERT(dep->flags & DFLAG_UTF8_ATOMS);
 
+
     if ((dep->state != ERTS_DE_STATE_CONNECTED &&
          dep->state != ERTS_DE_STATE_PENDING)
         || dep->connection_id != conn_id) {
@@ -697,7 +801,7 @@ erts_prepare_dist_ext(ErtsDistExternal *edep,
         ext++;
         size--;
     }
-    edep->ext_endp = ext + size;
+
     ep = ext;
 
     if (size < 2)
@@ -713,16 +817,33 @@ erts_prepare_dist_ext(ErtsDistExternal *edep,
 	goto fail;
     }
 
+    edep->heap_size = -1;
+    edep->flags = 0;
+    edep->dep = dep;
+    edep->connection_id = conn_id;
+    edep->data->ext_endp = ext+size;
+    edep->data->binp = binp;
+    edep->data->seq_id = 0;
+    edep->data->frag_id = 1;
+
     if (dep->flags & DFLAG_DIST_HDR_ATOM_CACHE)
         edep->flags |= ERTS_DIST_EXT_DFLAG_HDR;
 
-    edep->connection_id = dep->connection_id;
-
-    if (ep[1] != DIST_HEADER) {
+    if (ep[1] != DIST_HEADER && ep[1] != DIST_FRAG_HEADER && ep[1] != DIST_FRAG_CONT) {
 	if (edep->flags & ERTS_DIST_EXT_DFLAG_HDR)
 	    goto bad_hdr;
 	edep->attab.size = 0;
-	edep->extp = ext;
+	edep->data->extp = ext;
+    }
+    else if (ep[1] == DIST_FRAG_CONT) {
+        if (!(dep->flags & DFLAG_FRAGMENTS))
+            goto bad_hdr;
+        edep->attab.size = 0;
+	edep->data->extp = ext + 1 + 1 + 8 + 8;
+        edep->data->seq_id = get_int64(&ep[2]);
+        edep->data->frag_id = get_int64(&ep[2+8]);
+        erts_de_runlock(dep);
+        return ERTS_PREP_DIST_EXT_FRAG_CONT;
     }
     else {
 	int tix;
@@ -731,9 +852,17 @@ erts_prepare_dist_ext(ErtsDistExternal *edep,
 	if (!(edep->flags & ERTS_DIST_EXT_DFLAG_HDR))
 	    goto bad_hdr;
 
+        if (ep[1] == DIST_FRAG_HEADER) {
+            if (!(dep->flags & DFLAG_FRAGMENTS))
+                goto bad_hdr;
+            edep->data->seq_id = get_int64(&ep[2]);
+            edep->data->frag_id = get_int64(&ep[2+8]);
+            ep += 16;
+        }
+
 #undef CHKSIZE
 #define CHKSIZE(SZ) \
-	do { if ((SZ) > edep->ext_endp - ep) goto bad_hdr; } while(0)
+	do { if ((SZ) > edep->data->ext_endp - ep) goto bad_hdr; } while(0)
 
 	CHKSIZE(1+1+1);
 	ep += 2;
@@ -863,7 +992,7 @@ erts_prepare_dist_ext(ErtsDistExternal *edep,
 #endif
 	    }
 	}
-	edep->extp = ep;
+	edep->data->extp = ep;
 #ifdef ERTS_DEBUG_USE_DIST_SEP
 	if (*ep != VERSION_MAGIC)
 	    goto bad_hdr;
@@ -888,7 +1017,7 @@ erts_prepare_dist_ext(ErtsDistExternal *edep,
 		      erts_this_node->sysname,
 		      edep->dep->sysname,
 		      dist_entry_channel_no(edep->dep));
-	for (ep = ext; ep < edep->ext_endp; ep++)
+	for (ep = ext; ep < edep->data->ext_endp; ep++)
 	    erts_dsprintf(dsbufp, ep != ext ? ",%b8u" : "<<%b8u", *ep);
 	erts_dsprintf(dsbufp, ">>");
 	erts_send_warning_to_logger_nogl(dsbufp);
@@ -913,9 +1042,9 @@ bad_dist_ext(ErtsDistExternal *edep)
 		      erts_this_node->sysname,
 		      dep->sysname,
 		      dist_entry_channel_no(dep));
-	for (ep = edep->extp; ep < edep->ext_endp; ep++)
+	for (ep = edep->data->extp; ep < edep->data->ext_endp; ep++)
 	    erts_dsprintf(dsbufp,
-			  ep != edep->extp ? ",%b8u" : "<<...,%b8u",
+			  ep != edep->data->extp ? ",%b8u" : "<<...,%b8u",
 			  *ep);
 	erts_dsprintf(dsbufp, ">>\n");
 	erts_dsprintf(dsbufp, "ATOM_CACHE_REF translations: ");
@@ -933,30 +1062,59 @@ bad_dist_ext(ErtsDistExternal *edep)
 }
 
 Sint
-erts_decode_dist_ext_size(ErtsDistExternal *edep)
+erts_decode_dist_ext_size(ErtsDistExternal *edep, int kill_connection, int payload)
 {
     Sint res;
     byte *ep;
-    if (edep->extp >= edep->ext_endp)
+
+    if (edep->data->frag_id > 1 && payload) {
+        Uint sz = 0;
+        Binary *bin;
+        int i;
+        byte *ep;
+
+        for (i = 0; i < edep->data->frag_id; i++)
+            sz += edep->data[i].ext_endp - edep->data[i].extp;
+
+        bin = erts_bin_nrml_alloc(sz);
+        ep = (byte*)bin->orig_bytes;
+
+        for (i = 0; i < edep->data->frag_id; i++) {
+            sys_memcpy(ep, edep->data[i].extp, edep->data[i].ext_endp - edep->data[i].extp);
+            ep += edep->data[i].ext_endp - edep->data[i].extp;
+            erts_bin_release(edep->data[i].binp);
+            edep->data[i].binp = NULL;
+            edep->data[i].extp = NULL;
+            edep->data[i].ext_endp = NULL;
+        }
+
+        edep->data->frag_id = 1;
+        edep->data->extp = (byte*)bin->orig_bytes;
+        edep->data->ext_endp = ep;
+        edep->data->binp = bin;
+    }
+
+    if (edep->data->extp >= edep->data->ext_endp)
 	goto fail;
 #ifndef ERTS_DEBUG_USE_DIST_SEP
     if (edep->flags & ERTS_DIST_EXT_DFLAG_HDR) {
-	if (*edep->extp == VERSION_MAGIC)
+	if (*edep->data->extp == VERSION_MAGIC)
 	    goto fail;
-	ep = edep->extp;
+	ep = edep->data->extp;
     }
     else
 #endif
     {
-	if (*edep->extp != VERSION_MAGIC)
+	if (*edep->data->extp != VERSION_MAGIC)
 	    goto fail;
-	ep = edep->extp+1;
+	ep = edep->data->extp+1;
     }
-    res = decoded_size(ep, edep->ext_endp, 0, NULL);
+    res = decoded_size(ep, edep->data->ext_endp, 0, NULL);
     if (res >= 0)
 	return res;
  fail:
-    bad_dist_ext(edep);
+    if (kill_connection)
+        bad_dist_ext(edep);
     return -1;
 }
 
@@ -982,12 +1140,15 @@ Sint erts_decode_ext_size_ets(byte *ext, Uint size)
 */
 Eterm
 erts_decode_dist_ext(ErtsHeapFactory* factory,
-		     ErtsDistExternal *edep)
+		     ErtsDistExternal *edep,
+                     int kill_connection)
 {
     Eterm obj;
-    byte* ep = edep->extp;
+    byte* ep;
+
+    ep = edep->data->extp;
 
-    if (ep >= edep->ext_endp)
+    if (ep >= edep->data->ext_endp)
 	goto error;
 #ifndef ERTS_DEBUG_USE_DIST_SEP
     if (edep->flags & ERTS_DIST_EXT_DFLAG_HDR) {
@@ -1005,14 +1166,15 @@ erts_decode_dist_ext(ErtsHeapFactory* factory,
     if (!ep)
 	goto error;
 
-    edep->extp = ep;
+    edep->data->extp = ep;
 
     return obj;
 
  error:
     erts_factory_undo(factory);
 
-    bad_dist_ext(edep);
+    if (kill_connection)
+        bad_dist_ext(edep);
 
     return THE_NON_VALUE;
 }
@@ -1029,6 +1191,7 @@ Eterm erts_decode_ext(ErtsHeapFactory* factory, byte **ext, Uint32 flags)
     if (flags) {
         ASSERT(flags == ERTS_DIST_EXT_BTT_SAFE);
         ede.flags = flags; /* a dummy struct just for the flags */
+        ede.data = NULL;
         edep = &ede;
     } else {
         edep = NULL;
@@ -1057,6 +1220,7 @@ BIF_RETTYPE erts_debug_dist_ext_to_term_2(BIF_ALIST_2)
     Eterm res;
     Sint hsz;
     ErtsDistExternal ede;
+    ErtsDistExternalData ede_data;
     Eterm *tp;
     Eterm real_bin;
     Uint offset;
@@ -1069,7 +1233,8 @@ BIF_RETTYPE erts_debug_dist_ext_to_term_2(BIF_ALIST_2)
     ede.flags = ERTS_DIST_EXT_ATOM_TRANS_TAB;
     ede.dep = NULL;
     ede.heap_size = -1;
-    
+    ede.data = &ede_data;
+
     if (is_not_tuple(BIF_ARG_1))
 	goto badarg;
     tp = tuple_val(BIF_ARG_1);
@@ -1094,15 +1259,17 @@ BIF_RETTYPE erts_debug_dist_ext_to_term_2(BIF_ALIST_2)
     if (bitsize != 0)
 	goto badarg;
 
-    ede.extp = binary_bytes(real_bin)+offset;
-    ede.ext_endp = ede.extp + size;
+    ede.data->extp = binary_bytes(real_bin)+offset;
+    ede.data->ext_endp = ede.data->extp + size;
+    ede.data->frag_id = 1;
+    ede.data->binp = NULL;
 
-    hsz = erts_decode_dist_ext_size(&ede);
+    hsz = erts_decode_dist_ext_size(&ede, 1, 1);
     if (hsz < 0)
 	goto badarg;
 
     erts_factory_proc_prealloc_init(&factory, BIF_P, hsz);
-    res = erts_decode_dist_ext(&factory, &ede);
+    res = erts_decode_dist_ext(&factory, &ede, 1);
     erts_factory_close(&factory);
 
     if (is_value(res))
@@ -1117,9 +1284,22 @@ static BIF_RETTYPE term_to_binary_trap_1(BIF_ALIST_1)
 {
     Eterm *tp = tuple_val(BIF_ARG_1);
     Eterm Term = tp[1];
-    Eterm bt = tp[2];
+    Eterm Opts = tp[2];
+    Eterm bt = tp[3];
     Binary *bin = erts_magic_ref2bin(bt);
-    Eterm res = erts_term_to_binary_int(BIF_P, Term, 0, 0,bin);
+    Eterm res = erts_term_to_binary_int(BIF_P, Term, Opts, 0, 0,bin);
+    if (is_non_value(res)) {
+        if (erts_set_gc_state(BIF_P, 1)
+            || MSO(BIF_P).overhead > BIN_VHEAP_SZ(BIF_P)) {
+            ERTS_VBUMP_ALL_REDS(BIF_P);
+        }
+        if (Opts == am_undefined)
+            ERTS_BIF_ERROR_TRAPPED1(BIF_P, SYSTEM_LIMIT,
+                                    bif_export[BIF_term_to_binary_1], Term);
+        else
+            ERTS_BIF_ERROR_TRAPPED2(BIF_P, SYSTEM_LIMIT,
+                                    bif_export[BIF_term_to_binary_2], Term, Opts);
+    }
     if (is_tuple(res)) {
 	ASSERT(BIF_P->flags & F_DISABLE_GC);
 	BIF_TRAP1(&term_to_binary_trap_export,BIF_P,res);
@@ -1136,7 +1316,12 @@ HIPE_WRAPPER_BIF_DISABLE_GC(term_to_binary, 1)
 
 BIF_RETTYPE term_to_binary_1(BIF_ALIST_1)
 {
-    Eterm res = erts_term_to_binary_int(BIF_P, BIF_ARG_1, 0, TERM_TO_BINARY_DFLAGS, NULL);
+    Eterm res = erts_term_to_binary_int(BIF_P, BIF_ARG_1, am_undefined,
+                                        0, TERM_TO_BINARY_DFLAGS, NULL);
+    if (is_non_value(res)) {
+	ASSERT(!(BIF_P->flags & F_DISABLE_GC));
+        BIF_ERROR(BIF_P, SYSTEM_LIMIT);
+    }
     if (is_tuple(res)) {
 	erts_set_gc_state(BIF_P, 0);
 	BIF_TRAP1(&term_to_binary_trap_export,BIF_P,res);
@@ -1195,7 +1380,12 @@ BIF_RETTYPE term_to_binary_2(BIF_ALIST_2)
 	goto error;
     }
 
-    res = erts_term_to_binary_int(p, Term, level, flags, NULL);
+    res = erts_term_to_binary_int(p, Term, BIF_ARG_2,
+                                  level, flags, NULL);
+    if (is_non_value(res)) {
+	ASSERT(!(BIF_P->flags & F_DISABLE_GC));
+        BIF_ERROR(BIF_P, SYSTEM_LIMIT);
+    }
     if (is_tuple(res)) {
 	erts_set_gc_state(p, 0);
 	BIF_TRAP1(&term_to_binary_trap_export,BIF_P,res);
@@ -1605,6 +1795,7 @@ static BIF_RETTYPE binary_to_term_int(Process* p, Eterm bin, B2TContext *ctx)
         case B2TDecodeBinary: {
 	    ErtsDistExternal fakedep;
             fakedep.flags = ctx->flags;
+            fakedep.data = NULL;
             dec_term(&fakedep, NULL, NULL, NULL, ctx);
             break;
 	}
@@ -1744,8 +1935,17 @@ external_size_1(BIF_ALIST_1)
 {
     Process* p = BIF_P;
     Eterm Term = BIF_ARG_1;
+    Uint size;
+
+    switch (erts_encode_ext_size(Term, &size)) {
+    case ERTS_EXT_SZ_SYSTEM_LIMIT:
+        BIF_ERROR(BIF_P, SYSTEM_LIMIT);
+    case ERTS_EXT_SZ_YIELD:
+        ERTS_INTERNAL_ERROR("Unexpected yield");
+    case ERTS_EXT_SZ_OK:
+        break;
+    }
 
-    Uint size = erts_encode_ext_size(Term);
     if (IS_USMALL(0, size)) {
 	BIF_RET(make_small(size));
     } else {
@@ -1788,7 +1988,15 @@ external_size_2(BIF_ALIST_2)
         goto error;
     }
 
-    size = erts_encode_ext_size_2(BIF_ARG_1, flags);
+    switch (erts_encode_ext_size_2(BIF_ARG_1, flags, &size)) {
+    case ERTS_EXT_SZ_SYSTEM_LIMIT:
+        BIF_ERROR(BIF_P, SYSTEM_LIMIT);
+    case ERTS_EXT_SZ_YIELD:
+        ERTS_INTERNAL_ERROR("Unexpected yield");
+    case ERTS_EXT_SZ_OK:
+        break;
+    }
+
     if (IS_USMALL(0, size)) {
         BIF_RET(make_small(size));
     } else {
@@ -1876,7 +2084,15 @@ erts_term_to_binary_simple(Process* p, Eterm Term, Uint size, int level, Uint fl
 Eterm
 erts_term_to_binary(Process* p, Eterm Term, int level, Uint flags) {
     Uint size;
-    size = encode_size_struct2(NULL, Term, flags) + 1 /* VERSION_MAGIC */;
+    switch (encode_size_struct_int(NULL, NULL, Term, flags, NULL, &size)) {
+    case ERTS_EXT_SZ_SYSTEM_LIMIT:
+        return THE_NON_VALUE;
+    case ERTS_EXT_SZ_YIELD:
+        ERTS_INTERNAL_ERROR("Unexpected yield");
+    case ERTS_EXT_SZ_OK:
+        break;
+    }
+    size++; /* VERSION_MAGIC */;
     return erts_term_to_binary_simple(p, Term, size, level, flags);
 }
 
@@ -1926,8 +2142,8 @@ static int ttb_context_destructor(Binary *context_bin)
     return 1;
 }
 
-static Eterm erts_term_to_binary_int(Process* p, Eterm Term, int level, Uint flags, 
-				     Binary *context_b) 
+static Eterm erts_term_to_binary_int(Process* p, Eterm Term, Eterm opts, int level,
+                                     Uint flags, Binary *context_b) 
 {
     Eterm *hp;
     Eterm res;
@@ -1945,18 +2161,17 @@ static Eterm erts_term_to_binary_int(Process* p, Eterm Term, int level, Uint fla
     do {								\
 	if (context_b == NULL) {					\
 	    context_b = erts_create_magic_binary(sizeof(TTBContext),    \
-                                                 ttb_context_destructor);   \
+                                                 ttb_context_destructor);\
 	    context =  ERTS_MAGIC_BIN_DATA(context_b);			\
-	    sys_memcpy(context,&c_buff,sizeof(TTBContext));			\
+	    sys_memcpy(context,&c_buff,sizeof(TTBContext));		\
 	}								\
     } while (0)
 
 #define RETURN_STATE()							\
     do {								\
-	static const int TUPLE2_SIZE = 2 + 1;				\
-	hp = HAlloc(p, ERTS_MAGIC_REF_THING_SIZE + TUPLE2_SIZE);        \
+	hp = HAlloc(p, ERTS_MAGIC_REF_THING_SIZE + 1 + 3);              \
 	c_term = erts_mk_magic_ref(&hp, &MSO(p), context_b);            \
-	res = TUPLE2(hp, Term, c_term);					\
+	res = TUPLE3(hp, Term, opts, c_term);                           \
 	BUMP_ALL_REDS(p);                                               \
 	return res;							\
     } while (0);
@@ -1982,11 +2197,17 @@ static Eterm erts_term_to_binary_int(Process* p, Eterm Term, int level, Uint fla
 		int level;
 		Uint flags;
 		/* Try for fast path */
-		if (encode_size_struct_int(&context->s.sc, NULL, Term,
-					   context->s.sc.flags, &reds, &size) < 0) {
+                switch (encode_size_struct_int(&context->s.sc, NULL, Term,
+                                               context->s.sc.flags, &reds, &size)) {
+                case ERTS_EXT_SZ_SYSTEM_LIMIT:
+                    BUMP_REDS(p, (initial_reds - reds) / TERM_TO_BINARY_LOOP_FACTOR);
+                    return THE_NON_VALUE;
+                case ERTS_EXT_SZ_YIELD:
 		    EXPORT_CONTEXT();
 		    /* Same state */
 		    RETURN_STATE();
+                case ERTS_EXT_SZ_OK:
+                    break;
 		}
 		++size; /* VERSION_MAGIC */
 		/* Move these to next state */
@@ -2348,7 +2569,7 @@ dec_atom(ErtsDistExternal *edep, byte* ep, Eterm* objp)
     return ep;
 }
 
-static ERTS_INLINE ErlNode* dec_get_node(Eterm sysname, Uint32 creation)
+static ERTS_INLINE ErlNode* dec_get_node(Eterm sysname, Uint32 creation, Eterm book)
 {
     if (sysname == INTERNAL_LOCAL_SYSNAME)  /* && DFLAG_INTERNAL_TAGS */
 	return erts_this_node;
@@ -2357,7 +2578,7 @@ static ERTS_INLINE ErlNode* dec_get_node(Eterm sysname, Uint32 creation)
 	&& (creation == erts_this_node->creation || creation == ORIG_CREATION))
 	return erts_this_node;
 
-    return erts_find_or_insert_node(sysname,creation);
+    return erts_find_or_insert_node(sysname,creation,book);
 }
 
 static byte*
@@ -2403,7 +2624,7 @@ dec_pid(ErtsDistExternal *edep, ErtsHeapFactory* factory, byte* ep,
      * We are careful to create the node entry only after all
      * validity tests are done.
      */
-    node = dec_get_node(sysname, cre);
+    node = dec_get_node(sysname, cre, make_boxed(factory->hp));
 
     if(node == erts_this_node) {
 	*objp = make_internal_pid(data);
@@ -2481,11 +2702,21 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 	    {
 		Eterm* cons = list_val(obj);
 		Eterm tl;
+                Uint len_cnt = WSTACK_POP(s);
 
 		obj = CAR(cons);
 		tl = CDR(cons);
-		WSTACK_PUSH2(s, (is_list(tl) ? ENC_ONE_CONS : ENC_TERM),
-			     tl);
+                if (is_list(tl)) {
+                    len_cnt++;
+                    WSTACK_PUSH3(s, len_cnt, ENC_ONE_CONS, tl);
+                }
+                else {
+                    byte* list_lenp = (byte*) WSTACK_POP(s);
+		    ASSERT(list_lenp[-1] == LIST_EXT);
+                    put_int32(len_cnt, list_lenp);
+
+                    WSTACK_PUSH2(s, ENC_TERM, tl);
+                }
 	    }
 	    break;
 	case ENC_PATCH_FUN_SIZE:
@@ -2689,10 +2920,7 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 	}
 	case LIST_DEF:
 	    {
-		int is_str;
-
-		i = is_external_string(obj, &is_str);
-		if (is_str) {
+		if (is_external_string(obj, &i)) {
 		    *ep++ = STRING_EXT;
 		    put_int16(i, ep);
 		    ep += 2;
@@ -2701,9 +2929,12 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 			*ep++ = unsigned_val(CAR(cons));
 			obj = CDR(cons);
 		    }
+		    r -= i;
 		} else {
+		    r -= i/2;
 		    *ep++ = LIST_EXT;
-		    put_int32(i, ep);
+                    /* Patch list length when we find end of list */
+                    WSTACK_PUSH2(s, (UWord)ep, 1);
 		    ep += 4;
 		    goto encode_one_cons;
 		}
@@ -2961,9 +3192,13 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
     return 0;
 }
 
+/** @brief Is it a list of bytes not longer than MAX_STRING_LEN?
+ * @param lenp out: string length or number of list cells traversed
+ * @return true/false
+ */
 static
-Uint
-is_external_string(Eterm list, int* p_is_string)
+int
+is_external_string(Eterm list, Uint* lenp)
 {
     Uint len = 0;
 
@@ -2975,29 +3210,15 @@ is_external_string(Eterm list, int* p_is_string)
 	Eterm* consp = list_val(list);
 	Eterm hd = CAR(consp);
 
-	if (!is_byte(hd)) {
-	    break;
+	if (!is_byte(hd) || ++len > MAX_STRING_LEN) {
+	    *lenp = len;
+            return 0;
 	}
-	len++;
 	list = CDR(consp);
     }
 
-    /*
-     * If we have reached the end of the list, and we have
-     * not exceeded the maximum length of a string, this
-     * is a string.
-     */
-    *p_is_string = is_nil(list) && len < MAX_STRING_LEN;
-
-    /*
-     * Continue to calculate the length.
-     */
-    while (is_list(list)) {
-	Eterm* consp = list_val(list);
-	len++;
-	list = CDR(consp);
-    }
-    return len;
+    *lenp = len;
+    return is_nil(list);
 }
 
 
@@ -3397,7 +3618,7 @@ dec_term_atom_common:
                     cre = get_int32(ep);
                     ep += 4;
                 }
-		node = dec_get_node(sysname, cre);
+		node = dec_get_node(sysname, cre, make_boxed(hp));
 		if(node == erts_this_node) {
 		    *objp = make_internal_port(num);
 		}
@@ -3468,7 +3689,7 @@ dec_term_atom_common:
 
 		cre = get_int32(ep);
 		ep += 4;
-		r0 = get_int32(ep); /* allow full word */
+		r0 = get_int32(ep);
 		ep += 4;
 
 	    ref_ext_common: {
@@ -3477,8 +3698,15 @@ dec_term_atom_common:
 		if (ref_words > ERTS_MAX_REF_NUMBERS)
 		    goto error;
 
-		node = dec_get_node(sysname, cre);
+		node = dec_get_node(sysname, cre, make_boxed(hp));
 		if(node == erts_this_node) {
+                    if (r0 >= MAX_REFERENCE) {
+                          /*
+                           * Must reject local refs with more than 18 bits
+                           * in first word as magic ref table relies on it.
+                           */
+                        goto error;
+                    }
 	
 		    rtp = (ErtsORefThing *) hp;
 		    ref_num = &rtp->num[0];
@@ -3565,6 +3793,30 @@ dec_term_atom_common:
 		    hp += heap_bin_size(n);
 		    sys_memcpy(hb->data, ep, n);
 		    *objp = make_binary(hb);
+		} else if (edep && edep->data && edep->data->binp &&
+                           n > (edep->data->binp->orig_size / 4)) {
+                    /* If we decode a refc binary from a distribution data
+                       entry we know that it is a refc binary to begin with
+                       so we just increment it and use the reference. This
+                       means that the entire distribution data entry will
+                       remain until this binary is de-allocated so we only
+                       do it if a substantial part (> 25%) of the data
+                       is a binary. */
+                    ProcBin* pb = (ProcBin *) hp;
+                    Binary* bptr = edep->data->binp;
+                    erts_refc_inc(&bptr->intern.refc, 1);
+                    pb->thing_word = HEADER_PROC_BIN;
+                    pb->size = n;
+                    pb->next = factory->off_heap->first;
+                    factory->off_heap->first = (struct erl_off_heap_header*)pb;
+                    pb->val = bptr;
+                    pb->bytes = (byte*) ep;
+                    ERTS_ASSERT((byte*)(bptr->orig_bytes) < ep &&
+                                ep+n <= (byte*)(bptr->orig_bytes+bptr->orig_size));
+                    pb->flags = 0;
+                    OH_OVERHEAD(factory->off_heap, pb->size / sizeof(Eterm));
+                    hp += PROC_BIN_SIZE;
+                    *objp = make_binary(pb);
 		} else {
 		    Binary* dbin = erts_bin_nrml_alloc(n);
 
@@ -4041,13 +4293,21 @@ error_hamt:
    to a sequence of bytes
    N.B. That this must agree with to_external2() above!!!
    (except for cached atoms) */
-static Uint encode_size_struct2(ErtsAtomCacheMap *acmp, Eterm obj, unsigned dflags) {
-    Uint res;
-    (void) encode_size_struct_int(NULL, acmp, obj, dflags, NULL, &res);
-    return res;
+static Uint encode_size_struct2(ErtsAtomCacheMap *acmp,
+                                Eterm obj,
+                                unsigned dflags) {
+    Uint size;
+    ErtsExtSzRes res = encode_size_struct_int(NULL, acmp, obj,
+                                              dflags, NULL, &size);
+    /*
+     * encode_size_struct2() only allowed when
+     * we know the result will always be OK!
+     */ 
+    ASSERT(res == ERTS_EXT_SZ_OK); (void) res;
+    return (Uint) size;
 }
 
-static int
+static ErtsExtSzRes
 encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 		       unsigned dflags, Sint *reds, Uint *res)
 {
@@ -4075,12 +4335,12 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
     for (;;) {
 	ASSERT(!is_header(obj));
 
-	if (ctx && --r == 0) {
-	    *reds = r;
+	if (ctx && --r <= 0) {
+	    *reds = 0;
 	    ctx->obj = obj;
 	    ctx->result = result;
 	    WSTACK_SAVE(s, &ctx->wstack);
-	    return -1;
+	    return ERTS_EXT_SZ_YIELD;
 	}
 	switch (tag_val_def(obj)) {
 	case NIL_DEF:
@@ -4166,8 +4426,10 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 	    result += (1 + encode_size_struct2(acmp, port_node_name(obj), dflags) +
 		      4 + 1);
 	    break;
-	case LIST_DEF:
-	    if ((m = is_string(obj)) && (m < MAX_STRING_LEN)) {
+	case LIST_DEF: {
+	    int is_str = is_external_string(obj, &m);
+	    r -= m/2;
+	    if (is_str) {
 		result += m + 2 + 1;
 	    } else {
 		result += 5;
@@ -4176,6 +4438,7 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 		continue; /* big loop */
 	    }
 	    break;
+	}
 	case TUPLE_DEF:
 	    {
 		Eterm* ptr = tuple_val(obj);
@@ -4253,11 +4516,26 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 		result += 32;   /* Yes, including the tag */
 	    }
 	    break;
-	case BINARY_DEF:
-	    if (dflags & DFLAG_INTERNAL_TAGS) {
+	case BINARY_DEF: {
+            ProcBin* pb = (ProcBin*) binary_val(obj);
+            Uint tot_bytes = pb->size;
+            if (!(dflags & DFLAG_INTERNAL_TAGS)) {
+#ifdef ARCH_64
+                if (tot_bytes >= (Uint) 0xffffffff) {
+                    if (pb->thing_word == HEADER_SUB_BIN) {
+                        ErlSubBin* sub = (ErlSubBin*) pb;
+                        tot_bytes += (sub->bitoffs + sub->bitsize+ 7) / 8;
+                    }
+                    if (tot_bytes > (Uint) 0xffffffff) {
+                        WSTACK_DESTROY(s);
+                        return ERTS_EXT_SZ_SYSTEM_LIMIT;
+                    }
+                }
+#endif
+            }
+            else {
 		ProcBin* pb = (ProcBin*) binary_val(obj);
 		Uint sub_extra = 0;
-		Uint tot_bytes = pb->size;
 		if (pb->thing_word == HEADER_SUB_BIN) {
 		    ErlSubBin* sub = (ErlSubBin*) pb;
 		    pb = (ProcBin*) binary_val(sub->orig);
@@ -4274,6 +4552,7 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 	    result += 1 + 4 + binary_size(obj) +
 		    5;			/* For unaligned binary */
 	    break;
+        }
 	case FUN_DEF:
 	    {
 		ErlFunThing* funp = (ErlFunThing *) fun_val(obj);
@@ -4306,7 +4585,7 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 	    break;
 
 	default:
-	    erts_exit(ERTS_ERROR_EXIT,"Internal data structure error (in encode_size_struct2)%x\n",
+	    erts_exit(ERTS_ERROR_EXIT,"Internal data structure error (in encode_size_struct_int) %x\n",
 		     obj);
 	}
 
@@ -4317,7 +4596,7 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 
         if (is_header(obj)) {
             switch (obj) {
-	    case LIST_TAIL_OP:
+            case LIST_TAIL_OP:
 		obj = (Eterm) WSTACK_POP(s);
 		if (is_list(obj)) {
 		    Eterm* cons = list_val(obj);
@@ -4343,10 +4622,10 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
     WSTACK_DESTROY(s);
     if (ctx) {
 	ASSERT(ctx->wstack.wstart == NULL);
-	*reds = r;
+	*reds = r < 0 ? 0 : r;
     }
     *res = result;
-    return 0;
+    return ERTS_EXT_SZ_OK;
 }
 
 
diff --git a/erts/emulator/beam/external.h b/erts/emulator/beam/external.h
index edac177cc6..e362a6c81f 100644
--- a/erts/emulator/beam/external.h
+++ b/erts/emulator/beam/external.h
@@ -58,6 +58,8 @@
 #define SMALL_ATOM_UTF8_EXT 'w'
 
 #define DIST_HEADER       'D'
+#define DIST_FRAG_HEADER  'E'
+#define DIST_FRAG_CONT    'F'
 #define ATOM_CACHE_REF    'R'
 #define ATOM_INTERNAL_REF2 'I'
 #define ATOM_INTERNAL_REF3 'K'
@@ -122,24 +124,26 @@ typedef struct {
 
 #define ERTS_DIST_CON_ID_MASK ((Uint32) 0x00ffffff) /* also in net_kernel.erl */
 
-typedef struct {
-    DistEntry *dep;
+struct binary;
+typedef struct erl_dist_external_data ErtsDistExternalData;
+
+struct erl_dist_external_data {
+    Uint64 seq_id;
+    Uint64 frag_id;
     byte *extp;
     byte *ext_endp;
+    struct binary *binp;
+};
+
+typedef struct erl_dist_external {
     Sint heap_size;
-    Uint32 connection_id;
+    DistEntry *dep;
     Uint32 flags;
+    Uint32 connection_id;
+    ErtsDistExternalData *data;
     ErtsAtomTranslationTable attab;
 } ErtsDistExternal;
 
-#define ERTS_DIST_EXT_SIZE(EDEP) \
-  (sizeof(ErtsDistExternal) \
-   - (((EDEP)->flags & ERTS_DIST_EXT_ATOM_TRANS_TAB) \
-      ? (ASSERT(0 <= (EDEP)->attab.size \
-		&& (EDEP)->attab.size <= ERTS_ATOM_CACHE_SIZE), \
-	 sizeof(Eterm)*(ERTS_ATOM_CACHE_SIZE - (EDEP)->attab.size)) \
-      : sizeof(ErtsAtomTranslationTable)))
-
 typedef struct {
     byte *extp;
     int exttmp;
@@ -155,36 +159,48 @@ void erts_reset_atom_cache_map(ErtsAtomCacheMap *);
 void erts_destroy_atom_cache_map(ErtsAtomCacheMap *);
 void erts_finalize_atom_cache_map(ErtsAtomCacheMap *, Uint32);
 
-Uint erts_encode_ext_dist_header_size(ErtsAtomCacheMap *);
-byte *erts_encode_ext_dist_header_setup(byte *, ErtsAtomCacheMap *);
+Uint erts_encode_ext_dist_header_size(ErtsAtomCacheMap *, Uint);
+byte *erts_encode_ext_dist_header_setup(byte *, ErtsAtomCacheMap *, Uint, Eterm);
+byte *erts_encode_ext_dist_header_fragment(byte **, Uint, Eterm);
 Sint erts_encode_ext_dist_header_finalize(ErtsDistOutputBuf*, DistEntry *, Uint32 dflags, Sint reds);
 struct erts_dsig_send_context;
-int erts_encode_dist_ext_size(Eterm, Uint32, ErtsAtomCacheMap*, Uint* szp);
-int erts_encode_dist_ext_size_int(Eterm term, struct erts_dsig_send_context* ctx, Uint* szp);
+
+typedef enum {
+    ERTS_EXT_SZ_OK,
+    ERTS_EXT_SZ_YIELD,
+    ERTS_EXT_SZ_SYSTEM_LIMIT
+} ErtsExtSzRes;
+
+ErtsExtSzRes erts_encode_dist_ext_size(Eterm, Uint32, ErtsAtomCacheMap*, Uint* szp);
+ErtsExtSzRes erts_encode_dist_ext_size_ctx(Eterm term, struct erts_dsig_send_context* ctx, Uint* szp);
 struct TTBEncodeContext_;
 int erts_encode_dist_ext(Eterm, byte **, Uint32, ErtsAtomCacheMap *,
 			  struct TTBEncodeContext_ *, Sint* reds);
 
-Uint erts_encode_ext_size(Eterm);
-Uint erts_encode_ext_size_2(Eterm, unsigned);
+ErtsExtSzRes erts_encode_ext_size(Eterm, Uint *szp);
+ErtsExtSzRes erts_encode_ext_size_2(Eterm, unsigned, Uint *szp);
 Uint erts_encode_ext_size_ets(Eterm);
 void erts_encode_ext(Eterm, byte **);
 byte* erts_encode_ext_ets(Eterm, byte *, struct erl_off_heap_header** ext_off_heap);
 
-ERTS_GLB_INLINE void erts_free_dist_ext_copy(ErtsDistExternal *);
-ERTS_GLB_INLINE void *erts_dist_ext_trailer(ErtsDistExternal *);
-ErtsDistExternal *erts_make_dist_ext_copy(ErtsDistExternal *, Uint);
-void *erts_dist_ext_trailer(ErtsDistExternal *);
-void erts_destroy_dist_ext_copy(ErtsDistExternal *);
-
-#define ERTS_PREP_DIST_EXT_FAILED       (-1)
-#define ERTS_PREP_DIST_EXT_SUCCESS      (0)
-#define ERTS_PREP_DIST_EXT_CLOSED       (1)
-
-int erts_prepare_dist_ext(ErtsDistExternal *, byte *, Uint,
-			  DistEntry *, Uint32 conn_id, ErtsAtomCache *);
-Sint erts_decode_dist_ext_size(ErtsDistExternal *);
-Eterm erts_decode_dist_ext(ErtsHeapFactory* factory, ErtsDistExternal *);
+Uint erts_dist_ext_size(ErtsDistExternal *);
+Uint erts_dist_ext_data_size(ErtsDistExternal *);
+void erts_free_dist_ext_copy(ErtsDistExternal *);
+void erts_make_dist_ext_copy(ErtsDistExternal *, ErtsDistExternal *);
+void erts_dist_ext_frag(ErtsDistExternalData *, ErtsDistExternal *);
+#define erts_get_dist_ext(HFRAG) ((ErtsDistExternal*)((HFRAG)->mem + (HFRAG)->used_size))
+
+typedef enum {
+    ERTS_PREP_DIST_EXT_FAILED,
+    ERTS_PREP_DIST_EXT_SUCCESS,
+    ERTS_PREP_DIST_EXT_FRAG_CONT,
+    ERTS_PREP_DIST_EXT_CLOSED
+} ErtsPrepDistExtRes;
+
+ErtsPrepDistExtRes erts_prepare_dist_ext(ErtsDistExternal *, byte *, Uint, struct binary *,
+                                         DistEntry *, Uint32, ErtsAtomCache *);
+Sint erts_decode_dist_ext_size(ErtsDistExternal *, int, int);
+Eterm erts_decode_dist_ext(ErtsHeapFactory*, ErtsDistExternal *, int);
 
 Sint erts_decode_ext_size(byte*, Uint);
 Sint erts_decode_ext_size_ets(byte*, Uint);
@@ -200,25 +216,4 @@ int erts_debug_max_atom_out_cache_index(void);
 int erts_debug_atom_to_out_cache_index(Eterm);
 void transcode_free_ctx(DistEntry* dep);
 
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-ERTS_GLB_INLINE void
-erts_free_dist_ext_copy(ErtsDistExternal *edep)
-{
-    if (edep->dep)
-	erts_deref_dist_entry(edep->dep);
-    erts_free(ERTS_ALC_T_EXT_TERM_DATA, edep);
-}
-
-ERTS_GLB_INLINE void *
-erts_dist_ext_trailer(ErtsDistExternal *edep)
-{
-    void *res = (void *) (edep->ext_endp
-			  + ERTS_EXTRA_DATA_ALIGN_SZ(edep->ext_endp));
-    ASSERT((((UWord) res) % sizeof(Uint)) == 0);
-    return res;
-}
-
-#endif
-
 #endif /* ERL_EXTERNAL_H__ */
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 0631404599..0c2cf98033 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -113,6 +113,9 @@ extern Eterm erts_bld_resource_ref(Eterm** hp, ErlOffHeap*, ErtsResource*);
 extern void erts_pre_nif(struct enif_environment_t*, Process*,
 			 struct erl_module_nif*, Process* tracee);
 extern void erts_post_nif(struct enif_environment_t* env);
+#ifdef DEBUG
+int erts_dbg_is_resource_dying(ErtsResource*);
+#endif
 extern void erts_resource_stop(ErtsResource*, ErlNifEvent, int is_direct_call);
 void erts_fire_nif_monitor(ErtsMonitor *tmon);
 void erts_nif_demonitored(ErtsResource* resource);
@@ -131,6 +134,7 @@ extern Eterm erts_nif_call_function(Process *p, Process *tracee,
 
 int erts_call_dirty_nif(ErtsSchedulerData *esdp, Process *c_p,
 			BeamInstr *I, Eterm *reg);
+ErtsMessage* erts_create_message_from_nif_env(ErlNifEnv* msg_env);
 
 
 /* Driver handle (wrapper for old plain handle) */
@@ -292,7 +296,6 @@ union erl_off_heap_ptr {
 /* controls warning mapping in error_logger */
 
 extern Eterm node_cookie;
-extern Uint display_items;	/* no of items to display in traces etc */
 
 extern int erts_backtrace_depth;
 extern erts_atomic32_t erts_max_gen_gcs;
@@ -892,6 +895,11 @@ void erts_init_bif(void);
 Eterm erl_send(Process *p, Eterm to, Eterm msg);
 int erts_set_group_leader(Process *proc, Eterm new_gl);
 
+/* erl_bif_guard.c */
+
+void erts_init_bif_guard(void);
+Eterm erts_trapping_length_1(Process* p, Eterm* args);
+
 /* erl_bif_op.c */
 
 Eterm erl_is_function(Process* p, Eterm arg1, Eterm arg2);
@@ -899,7 +907,8 @@ Eterm erl_is_function(Process* p, Eterm arg1, Eterm arg2);
 /* beam_bif_load.c */
 Eterm erts_check_process_code(Process *c_p, Eterm module, int *redsp, int fcalls);
 Eterm erts_proc_copy_literal_area(Process *c_p, int *redsp, int fcalls, int gc_allowed);
-
+void erts_debug_foreach_release_literal_area_off_heap(void (*func)(ErlOffHeap *, void *),
+                                                      void *arg);
 typedef struct ErtsLiteralArea_ {
     struct erl_off_heap_header *off_heap;
     Eterm *end;
@@ -962,7 +971,7 @@ void init_break_handler(void);
 void erts_set_ignore_break(void);
 void erts_replace_intr(void);
 void process_info(fmtfn_t, void *);
-void print_process_info(fmtfn_t, void *, Process*);
+void print_process_info(fmtfn_t, void *, Process*, ErtsProcLocks);
 void info(fmtfn_t, void *);
 void loaded(fmtfn_t, void *);
 void erts_print_base64(fmtfn_t to, void *to_arg, byte* src, Uint size);
@@ -1064,17 +1073,46 @@ Uint size_object_x(Eterm, erts_literal_area_t*);
 #define size_object_litopt(Term,LitArea) size_object_x(Term,LitArea)
 
 Uint copy_shared_calculate(Eterm, erts_shcopy_t*);
-Eterm copy_shared_perform(Eterm, Uint, erts_shcopy_t*, Eterm**, ErlOffHeap*);
-
 Uint size_shared(Eterm);
 
+/* #define ERTS_COPY_REGISTER_LOCATION */
+
+#ifdef ERTS_COPY_REGISTER_LOCATION
+
+#define copy_shared_perform(U, V, X, Y, Z) \
+    copy_shared_perform_x((U), (V), (X), (Y), (Z), __FILE__, __LINE__)
+Eterm copy_shared_perform_x(Eterm, Uint, erts_shcopy_t*, Eterm**, ErlOffHeap*,
+                            char *file, int line);
+
+Eterm copy_struct_x(Eterm, Uint, Eterm**, ErlOffHeap*, Uint*, erts_literal_area_t*,
+                    char *file, int line);
+#define copy_struct(Obj,Sz,HPP,OH) \
+    copy_struct_x(Obj,Sz,HPP,OH,NULL,NULL,__FILE__,__LINE__)
+#define copy_struct_litopt(Obj,Sz,HPP,OH,LitArea) \
+    copy_struct_x(Obj,Sz,HPP,OH,NULL,LitArea,__FILE__,__LINE__)
+
+#define copy_shallow(R, SZ, HPP, OH) \
+    copy_shallow_x((R), (SZ), (HPP), (OH), __FILE__, __LINE__)
+Eterm copy_shallow_x(Eterm* ERTS_RESTRICT, Uint, Eterm**, ErlOffHeap*,
+                     char *file, int line);
+
+#else
+
+#define copy_shared_perform(U, V, X, Y, Z) \
+    copy_shared_perform_x((U), (V), (X), (Y), (Z))
+Eterm copy_shared_perform_x(Eterm, Uint, erts_shcopy_t*, Eterm**, ErlOffHeap*);
+
 Eterm copy_struct_x(Eterm, Uint, Eterm**, ErlOffHeap*, Uint*, erts_literal_area_t*);
 #define copy_struct(Obj,Sz,HPP,OH) \
     copy_struct_x(Obj,Sz,HPP,OH,NULL,NULL)
 #define copy_struct_litopt(Obj,Sz,HPP,OH,LitArea) \
     copy_struct_x(Obj,Sz,HPP,OH,NULL,LitArea)
 
-Eterm copy_shallow(Eterm* ERTS_RESTRICT, Uint, Eterm**, ErlOffHeap*);
+#define copy_shallow(R, SZ, HPP, OH) \
+    copy_shallow_x((R), (SZ), (HPP), (OH))
+Eterm copy_shallow_x(Eterm* ERTS_RESTRICT, Uint, Eterm**, ErlOffHeap*);
+
+#endif
 
 void erts_move_multi_frags(Eterm** hpp, ErlOffHeap*, ErlHeapFragment* first,
 			   Eterm* refs, unsigned nrefs, int literals);
@@ -1088,7 +1126,7 @@ extern int distribution_info(fmtfn_t, void *);
 extern int is_node_name_atom(Eterm a);
 
 extern int erts_net_message(Port *, DistEntry *, Uint32 conn_id,
-			    byte *, ErlDrvSizeT, byte *, ErlDrvSizeT);
+			    byte *, ErlDrvSizeT, Binary *, byte *, ErlDrvSizeT);
 
 extern void init_dist(void);
 extern int stop_dist(void);
@@ -1208,10 +1246,11 @@ Uint64 erts_timestamp_millis(void);
 
 Export* erts_find_function(Eterm, Eterm, unsigned int, ErtsCodeIndex);
 
-void *erts_calc_stacklimit(char *prev_c, UWord stacksize);
-int erts_check_below_limit(char *ptr, char *limit);
-int erts_check_above_limit(char *ptr, char *limit);
-void *erts_ptr_id(void *ptr);
+/* ERTS_NOINLINE prevents link-time optimization across modules */
+void *erts_calc_stacklimit(char *prev_c, UWord stacksize) ERTS_NOINLINE;
+int erts_check_below_limit(char *ptr, char *limit) ERTS_NOINLINE;
+int erts_check_above_limit(char *ptr, char *limit) ERTS_NOINLINE;
+void *erts_ptr_id(void *ptr) ERTS_NOINLINE;
 
 Eterm store_external_or_ref_in_proc_(Process *, Eterm);
 Eterm store_external_or_ref_(Uint **, ErlOffHeap*, Eterm);
@@ -1248,6 +1287,10 @@ Uint erts_persistent_term_count(void);
 void erts_init_persistent_dumping(void);
 extern ErtsLiteralArea** erts_persistent_areas;
 extern Uint erts_num_persistent_areas;
+void erts_debug_foreach_persistent_term_off_heap(void (*func)(ErlOffHeap *, void *),
+                                                 void *arg);
+int erts_debug_have_accessed_literal_area(ErtsLiteralArea *lap);
+void erts_debug_save_accessed_literal_area(ErtsLiteralArea *lap);
 
 /* external.c */
 void erts_init_external(void);
@@ -1303,14 +1346,7 @@ Sint intlist_to_buf(Eterm, char*, Sint); /* most callers pass plain char*'s */
 int erts_unicode_list_to_buf(Eterm list, byte *buf, Sint len, Sint* written);
 Sint erts_unicode_list_to_buf_len(Eterm list);
 
-struct Sint_buf {
-#if defined(ARCH_64)
-    char s[22];
-#else
-    char s[12];
-#endif
-};	
-char* Sint_to_buf(Sint, struct Sint_buf*);
+int Sint_to_buf(Sint num, int base, char **buf_p, size_t buf_size);
 
 #define ERTS_IOLIST_STATE_INITER(C_P, OBJ)	\
     {(C_P), 0, 0, (OBJ), {NULL, NULL, NULL, ERTS_ALC_T_INVALID}, 0, 0}
diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab
index 42c1168f85..7cffe7fb5c 100644
--- a/erts/emulator/beam/instrs.tab
+++ b/erts/emulator/beam/instrs.tab
@@ -238,6 +238,7 @@ HANDLE_APPLY_FUN_ERROR() {
 }
 
 DISPATCH_FUN(I) {
+    //| -no_next
     SET_I($I);
     Dispatchfun();
 }
@@ -299,6 +300,7 @@ i_call_fun_last(Fun, Deallocate) {
 }
 
 return() {
+    //| -no_next
     SET_I(c_p->cp);
     DTRACE_RETURN_FROM_PC(c_p);
 
@@ -357,7 +359,7 @@ i_get_tuple_element2(Src, Element, Dst) {
     dst[1] = E2;
 }
 
-i_get_tuple_element2y(Src, Element, D1, D2) {
+i_get_tuple_element2_dst(Src, Element, D1, D2) {
     Eterm* src;
     Eterm E1, E2;
     src = ADD_BYTE_OFFSET(tuple_val($Src), $Element);
@@ -434,6 +436,30 @@ init(Y) {
     make_blank($Y);
 }
 
+init_seq3(Y1) {
+    Eterm* dst = &$Y1;
+    make_blank(dst[0]);
+    make_blank(dst[1]);
+    make_blank(dst[2]);
+}
+
+init_seq4(Y1) {
+    Eterm* dst = &$Y1;
+    make_blank(dst[0]);
+    make_blank(dst[1]);
+    make_blank(dst[2]);
+    make_blank(dst[3]);
+}
+
+init_seq5(Y1) {
+    Eterm* dst = &$Y1;
+    make_blank(dst[0]);
+    make_blank(dst[1]);
+    make_blank(dst[2]);
+    make_blank(dst[3]);
+    make_blank(dst[4]);
+}
+
 init2(Y1, Y2) {
     make_blank($Y1);
     make_blank($Y2);
@@ -451,6 +477,13 @@ i_make_fun(FunP, NumFree) {
     HEAVY_SWAPIN;
 }
 
+move_trim(Src, Dst, Words) {
+    Uint cp = E[0];
+    $Dst = $Src;
+    E += $Words;
+    E[0] = cp;
+}
+
 i_trim(Words) {
     Uint cp = E[0];
     E += $Words;
@@ -467,10 +500,6 @@ move3(S1, D1, S2, D2, S3, D3) {
     $D3 = $S3;
 }
 
-move_dup(Src, D1, D2) {
-    $D1 = $D2 = $Src;
-}
-
 move2_par(S1, D1, S2, D2) {
     Eterm V1, V2;
     V1 = $S1;
@@ -486,6 +515,48 @@ move_shift(Src, SD, D) {
     $SD = V;
 }
 
+move_src_window2(Src, D1, D2) {
+    Eterm* src = &$Src;
+    Eterm s1, s2;
+    s1 = src[0];
+    s2 = src[1];
+    $D1 = s1;
+    $D2 = s2;
+}
+
+move_src_window3(Src, D1, D2, D3) {
+    Eterm* src = &$Src;
+    Eterm s1, s2, s3;
+    s1 = src[0];
+    s2 = src[1];
+    s3 = src[2];
+    $D1 = s1;
+    $D2 = s2;
+    $D3 = s3;
+}
+
+move_src_window4(Src, D1, D2, D3, D4) {
+    Eterm* src = &$Src;
+    Eterm s1, s2, s3, s4;
+    s1 = src[0];
+    s2 = src[1];
+    s3 = src[2];
+    s4 = src[3];
+    $D1 = s1;
+    $D2 = s2;
+    $D3 = s3;
+    $D4 = s4;
+}
+
+move_window2(S1, S2, D) {
+    Eterm xt0, xt1;
+    Eterm* y = &$D;
+    xt0  = $S1;
+    xt1  = $S2;
+    y[0] = xt0;
+    y[1] = xt1;
+}
+
 move_window3(S1, S2, S3, D) {
     Eterm xt0, xt1, xt2;
     Eterm* y = &$D;
@@ -559,17 +630,19 @@ update_list(Hd, Dst) {
     HTOP += 2;
 }
 
-i_put_tuple := i_put_tuple.make.fill;
-
-i_put_tuple.make(Dst) {
-    $Dst = make_tuple(HTOP);
-}
-
-i_put_tuple.fill(Arity) {
+put_tuple2(Dst, Arity) {
     Eterm* hp = HTOP;
     Eterm arity = $Arity;
 
+    /*
+     * If operands are not packed (in the 32-bit VM),
+     * is is not safe to use $Dst directly after I
+     * has been updated.
+     */
+    Eterm* dst_ptr = &($Dst);
+
     //| -no_next
+    ASSERT(arity != 0);
     *hp++ = make_arityval(arity);
     I = $NEXT_INSTRUCTION;
     do {
@@ -586,6 +659,7 @@ i_put_tuple.fill(Arity) {
             break;
         }
     } while (--arity != 0);
+    *dst_ptr = make_tuple(HTOP);
     HTOP = hp;
     ASSERT(VALID_INSTR(* (Eterm *)I));
     Goto(*I);
@@ -637,12 +711,6 @@ is_nonempty_list(Fail, Src) {
     }
 }
 
-is_nonempty_list_test_heap(Fail, Need, Live) {
-    //| -no_prefetch
-    $is_nonempty_list($Fail, x(0));
-    $test_heap($Need, $Live);
-}
-
 is_nonempty_list_allocate(Fail, Src, Need, Live) {
     //| -no_prefetch
     $is_nonempty_list($Fail, $Src);
@@ -655,13 +723,27 @@ is_nonempty_list_get_list(Fail, Src, Hd, Tl) {
     $get_list($Src, $Hd, $Tl);
 }
 
+is_nonempty_list_get_hd(Fail, Src, Hd) {
+    //| -no_prefetch
+    $is_nonempty_list($Fail, $Src);
+    $get_hd($Src, $Hd);
+}
+
+is_nonempty_list_get_tl(Fail, Src, Tl) {
+    //| -no_prefetch
+    $is_nonempty_list($Fail, $Src);
+    $get_tl($Src, $Tl);
+}
+
 jump(Fail) {
     $JUMP($Fail);
 }
 
-move_jump(Fail, Src) {
-    x(0) = $Src;
-    $jump($Fail);
+move_jump(Lbl, Src, Dst) {
+    Eterm lbl = $Lbl;
+    Eterm src = $Src;
+    $Dst = src;
+    $JUMP(lbl);
 }
 
 //
@@ -704,12 +786,18 @@ is_function(Fail, Src) {
     }
 }
 
-is_function2(Fail, Fun, Arity) {
+cold_is_function2(Fail, Fun, Arity) {
     if (erl_is_function(c_p, $Fun, $Arity) != am_true ) {
         $FAIL($Fail);
     }
 }
 
+hot_is_function2(Fail, Fun, Arity) {
+    if (!is_function2($Fun, $Arity)) {
+        $FAIL($Fail);
+    }
+}
+
 is_integer(Fail, Src) {
     if (is_not_integer($Src)) {
         $FAIL($Fail);
@@ -767,6 +855,16 @@ is_tagged_tuple(Fail, Src, Arityval, Tag) {
     }
 }
 
+is_tagged_tuple_ff(NotTupleFail, WrongRecordFail, Src, Arityval, Tag) {
+    Eterm term = $Src;
+    if (is_not_tuple(term)) {
+        $FAIL($NotTupleFail);
+    } else if (ERTS_UNLIKELY((tuple_val(term))[0] != $Arityval ||
+                             (tuple_val(term))[1] != $Tag)) {
+        $FAIL($WrongRecordFail);
+    }
+}
+
 is_tuple(Fail, Src) {
     if (is_not_tuple($Src)) {
         $FAIL($Fail);
@@ -786,6 +884,16 @@ test_arity(Fail, Pointer, Arity) {
     }
 }
 
+test_arity_get_tuple_element(Fail, Pointer, Arity, Pos, Dst) {
+    Eterm* ptr = tuple_val($Pointer);
+    Eterm* src;
+    if (*ptr != $Arity) {
+        $FAIL($Fail);
+    }
+    src = ADD_BYTE_OFFSET(ptr, $Pos);
+    $Dst = *src;
+}
+
 i_is_eq_exact_immed(Fail, X, Y) {
     if ($X != $Y) {
         $FAIL($Fail);
@@ -824,12 +932,16 @@ i_is_ne_exact_literal(Fail, Src, Literal) {
     }
 }
 
-is_eq(Fail, X, Y) {
-    CMP_EQ_ACTION($X, $Y, $FAIL($Fail));
+is_eq(Fail, A, B) {
+    Eterm a = $A;
+    Eterm b = $B;
+    CMP_EQ_ACTION(a, b, $FAIL($Fail));
 }
 
-is_ne(Fail, X, Y) {
-    CMP_NE_ACTION($X, $Y, $FAIL($Fail));
+is_ne(Fail, A, B) {
+    Eterm a = $A;
+    Eterm b = $B;
+    CMP_NE_ACTION(a, b, $FAIL($Fail));
 }
 
 is_lt(Fail, X, Y) {
@@ -889,7 +1001,7 @@ catch_end(Y) {
             }
             /* only x(2) is included in the rootset here */
             if (E - HTOP < 3) {
-                SWAPOUT;
+                $GC_SWAPOUT();
                 PROCESS_MAIN_CHK_LOCKS(c_p);
                 FCALLS -= erts_garbage_collect_nobump(c_p, 3, reg+2, 1, FCALLS);
                 ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
@@ -948,22 +1060,34 @@ build_stacktrace() {
 }
 
 raw_raise() {
+    //| -no_prefetch
     Eterm class = x(0);
     Eterm value = x(1);
     Eterm stacktrace = x(2);
+    Eterm* freason_ptr;
+
+    /*
+     * Note that the i_raise instruction will override c_p->freason
+     * with the freason field stored inside the StackTrace struct in
+     * ftrace. Therefore, we must take care to store the class both
+     * inside the StackTrace struct and in c_p->freason (important if
+     * the class is different from the class of the original
+     * exception).
+     */
+    freason_ptr = get_freason_ptr_from_exc(stacktrace);
 
     if (class == am_error) {
-        c_p->freason = EXC_ERROR & ~EXF_SAVETRACE;
+        *freason_ptr = c_p->freason = EXC_ERROR & ~EXF_SAVETRACE;
         c_p->fvalue = value;
         c_p->ftrace = stacktrace;
         goto find_func_info;
     } else if (class == am_exit) {
-        c_p->freason = EXC_EXIT & ~EXF_SAVETRACE;
+        *freason_ptr = c_p->freason = EXC_EXIT & ~EXF_SAVETRACE;
         c_p->fvalue = value;
         c_p->ftrace = stacktrace;
         goto find_func_info;
     } else if (class == am_throw) {
-        c_p->freason = EXC_THROWN & ~EXF_SAVETRACE;
+        *freason_ptr = c_p->freason = EXC_THROWN & ~EXF_SAVETRACE;
         c_p->fvalue = value;
         c_p->ftrace = stacktrace;
         goto find_func_info;
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index 5325480901..45fef0c0e5 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -3644,20 +3644,22 @@ typedef struct {
     Eterm reason;
 } ErtsPortExitContext;
 
-static void link_port_exit(ErtsLink *lnk, void *vpectxt)
+static int link_port_exit(ErtsLink *lnk, void *vpectxt, Sint reds)
 {
     ErtsPortExitContext *pectxt = vpectxt;
     erts_proc_sig_send_link_exit(NULL, pectxt->port_id,
                                  lnk, pectxt->reason, NIL);
+    return 1;
 }
 
-static void monitor_port_exit(ErtsMonitor *mon, void *vpectxt)
+static int monitor_port_exit(ErtsMonitor *mon, void *vpectxt, Sint reds)
 {
     ErtsPortExitContext *pectxt = vpectxt;
     if (erts_monitor_is_target(mon))
         erts_proc_sig_send_monitor_down(mon, pectxt->reason);
     else
         erts_proc_sig_send_demonitor(mon);
+    return 1;
 }
 
 /* 'from' is sending 'this_port' an exit signal, (this_port must be internal).
@@ -4073,7 +4075,7 @@ done:
  * to the caller.
  */
 int
-erl_drv_port_control(Eterm port_num, char cmd, char* buff, ErlDrvSizeT size)
+erl_drv_port_control(Eterm port_num, unsigned int cmd, char* buff, ErlDrvSizeT size)
 {
     ErtsProc2PortSigData *sigdp = erts_port_task_alloc_p2p_sig_data();
 
@@ -4448,6 +4450,7 @@ erts_port_call(Process* c_p,
     char input_buf[256];
     char *bufp;
     byte *endp;
+    Uint uintsz;
     ErlDrvSizeT size;
     int try_call;
     erts_aint32_t sched_flags;
@@ -4460,7 +4463,9 @@ erts_port_call(Process* c_p,
 
     try_call = !(sched_flags & ERTS_PTS_FLGS_FORCE_SCHEDULE_OP);
 
-    size = erts_encode_ext_size(data);
+    if (erts_encode_ext_size(data, &uintsz) != ERTS_EXT_SZ_OK)
+        return ERTS_PORT_OP_BADARG;
+    size = (ErlDrvSizeT) uintsz;
 
     if (!try_call)
 	bufp = erts_alloc(ERTS_ALC_T_DRV_CALL_DATA, size);
@@ -4836,7 +4841,7 @@ typedef struct {
     void *arg;
 } prt_one_lnk_data;
 
-static void prt_one_monitor(ErtsMonitor *mon, void *vprtd)
+static int prt_one_monitor(ErtsMonitor *mon, void *vprtd, Sint reds)
 {
     ErtsMonitorData *mdp = erts_monitor_to_data(mon);
     prt_one_lnk_data *prtd = (prt_one_lnk_data *) vprtd;
@@ -4844,12 +4849,14 @@ static void prt_one_monitor(ErtsMonitor *mon, void *vprtd)
         erts_print(prtd->to, prtd->arg, "(%p,%T)", mon->other.ptr, mdp->ref);
     else
         erts_print(prtd->to, prtd->arg, "(%T,%T)", mon->other.item, mdp->ref);
+    return 1;
 }
 
-static void prt_one_lnk(ErtsLink *lnk, void *vprtd)
+static int prt_one_lnk(ErtsLink *lnk, void *vprtd, Sint reds)
 {
     prt_one_lnk_data *prtd = (prt_one_lnk_data *) vprtd;
     erts_print(prtd->to, prtd->arg, "%T", lnk->other.item);
+    return 1;
 }
 
 static void dump_port_state(fmtfn_t to, void *arg, erts_aint32_t state)
@@ -5100,7 +5107,7 @@ erts_port_resume_procs(Port *prt)
 
 	    erts_snprintf(port_str, sizeof(DTRACE_CHARBUF_NAME(port_str)), "%T", prt->common.id);
 	    while (plp2 != NULL) {
-		erts_snprintf(pid_str, sizeof(DTRACE_CHARBUF_NAME(pid_str)), "%T", plp2->pid);
+		erts_snprintf(pid_str, sizeof(DTRACE_CHARBUF_NAME(pid_str)), "%T", plp2->u.pid);
 		DTRACE2(process_port_unblocked, pid_str, port_str);
 	    }
 	}
@@ -5291,44 +5298,31 @@ erts_get_port_names(Eterm id, ErlDrvPort drv_port)
 	pnp->driver_name = NULL;
     }
     else {
-	int do_realloc = 1;
-	int len = -1;
-	size_t pnp_len = sizeof(ErtsPortNames);
-#ifndef DEBUG
-	pnp_len += 100; /* In most cases 100 characters will be enough... */
-	ASSERT(prt->common.id == id);
-#endif
-	pnp = erts_alloc(ERTS_ALC_T_PORT_NAMES, pnp_len);
-	do {
-	    int nlen;
-	    char *name, *driver_name;
-	    if (len > 0) {
-		erts_free(ERTS_ALC_T_PORT_NAMES, pnp);
-		pnp_len = sizeof(ErtsPortNames) + len;
-		pnp = erts_alloc(ERTS_ALC_T_PORT_NAMES, pnp_len);
-	    }
-	    name = prt->name;
-	    len = nlen = name ? sys_strlen(name) + 1 : 0;
-	    driver_name = (prt->drv_ptr ? prt->drv_ptr->name : NULL);
-	    len += driver_name ? sys_strlen(driver_name) + 1 : 0;
-	    if (len <= pnp_len - sizeof(ErtsPortNames)) {
-		if (!name)
-		    pnp->name = NULL;
-		else {
-		    pnp->name = ((char *) pnp) + sizeof(ErtsPortNames);
-		    sys_strcpy(pnp->name, name);
-		}
-		if (!driver_name)
-		    pnp->driver_name = NULL;
-		else {
-		    pnp->driver_name = (((char *) pnp)
-					+ sizeof(ErtsPortNames)
-					+ nlen);
-		    sys_strcpy(pnp->driver_name, driver_name);
-		}
-		do_realloc = 0;
-	    }
-	} while (do_realloc);
+	int len;
+        int nlen;
+        char *driver_name;
+
+        len = nlen = prt->name ? sys_strlen(prt->name) + 1 : 0;
+        driver_name = (prt->drv_ptr ? prt->drv_ptr->name : NULL);
+        len += driver_name ? sys_strlen(driver_name) + 1 : 0;
+
+        pnp = erts_alloc(ERTS_ALC_T_PORT_NAMES,
+                         sizeof(ErtsPortNames) + len);
+
+        if (!prt->name)
+            pnp->name = NULL;
+        else {
+            pnp->name = ((char *) pnp) + sizeof(ErtsPortNames);
+            sys_strcpy(pnp->name, prt->name);
+        }
+        if (!driver_name)
+            pnp->driver_name = NULL;
+        else {
+            pnp->driver_name = (((char *) pnp)
+                                + sizeof(ErtsPortNames)
+                                + nlen);
+            sys_strcpy(pnp->driver_name, driver_name);
+        }
     }
     return pnp;
 }
@@ -6177,6 +6171,7 @@ int driver_output_binary(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
 				dep,
                                 conn_id,
 				(byte*) hbuf, hlen,
+                                ErlDrvBinary2Binary(bin),
 				(byte*) (bin->orig_bytes+offs), len);
     }
     else
@@ -6222,12 +6217,14 @@ int driver_output2(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
 				    dep,
                                     conn_id,
 				    NULL, 0,
+                                    NULL,
 				    (byte*) hbuf, hlen);
 	else
 	    return erts_net_message(prt,
 				    dep,
                                     conn_id,
 				    (byte*) hbuf, hlen,
+                                    NULL,
 				    (byte*) buf, len);
     }
     else if (state & ERTS_PORT_SFLG_LINEBUF_IO)
diff --git a/erts/emulator/beam/macros.tab b/erts/emulator/beam/macros.tab
index 494fe8961e..1b5e5f66b0 100644
--- a/erts/emulator/beam/macros.tab
+++ b/erts/emulator/beam/macros.tab
@@ -63,10 +63,21 @@ JUMP(Fail) {
     Goto(*I);
 }
 
+GC_SWAPOUT() {
+    //
+    // Since a garbage collection is expensive anyway, we can afford
+    // to save the instruction counter so that the correct function will
+    // be pointed in the crash dump if the garbage collection fails
+    // because of insufficient memory.
+    //
+    SWAPOUT;
+    c_p->i = I;
+}
+
 GC_TEST(Ns, Nh, Live) {
     Uint need = $Nh + $Ns;
     if (ERTS_UNLIKELY(E - HTOP < need)) {
-       SWAPOUT;
+       $GC_SWAPOUT();
        PROCESS_MAIN_CHK_LOCKS(c_p);
        FCALLS -= erts_garbage_collect_nobump(c_p, need, reg, $Live, FCALLS);
        ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
@@ -79,7 +90,7 @@ GC_TEST(Ns, Nh, Live) {
 GC_TEST_PRESERVE(NeedHeap, Live, PreserveTerm) {
     Uint need = $NeedHeap;
     if (ERTS_UNLIKELY(E - HTOP < need)) {
-       SWAPOUT;
+       $GC_SWAPOUT();
        reg[$Live] = $PreserveTerm;
        PROCESS_MAIN_CHK_LOCKS(c_p);
        FCALLS -= erts_garbage_collect_nobump(c_p, need, reg, $Live+1, FCALLS);
diff --git a/erts/emulator/beam/map_instrs.tab b/erts/emulator/beam/map_instrs.tab
index c594a87298..5620d5a2d1 100644
--- a/erts/emulator/beam/map_instrs.tab
+++ b/erts/emulator/beam/map_instrs.tab
@@ -127,11 +127,21 @@ i_get_map_elements(Fail, Src, N) {
     }
 }
 
-update_map_assoc(Src, Dst, Live, N) {
+update_map_assoc := update_map_assoc.fetch.execute;
+
+update_map_assoc.head() {
+    Eterm map;
+}
+
+update_map_assoc.fetch(Src) {
+    map = $Src;
+}
+
+update_map_assoc.execute(Dst, Live, N) {
     Eterm res;
     Uint live = $Live;
 
-    reg[live] = $Src;
+    reg[live] = map;
     HEAVY_SWAPOUT;
     res = erts_gc_update_map_assoc(c_p, reg, live, $N, $NEXT_INSTRUCTION);
     HEAVY_SWAPIN;
@@ -141,11 +151,21 @@ update_map_assoc(Src, Dst, Live, N) {
     $NEXT($NEXT_INSTRUCTION+$N);
 }
 
-update_map_exact(Fail, Src, Dst, Live, N) {
+update_map_exact := update_map_exact.fetch.execute;
+
+update_map_exact.head() {
+    Eterm map;
+}
+
+update_map_exact.fetch(Src) {
+    map = $Src;
+}
+
+update_map_exact.execute(Fail, Dst, Live, N) {
     Eterm res;
     Uint live = $Live;
 
-    reg[live] = $Src;
+    reg[live] = map;
     HEAVY_SWAPOUT;
     res = erts_gc_update_map_exact(c_p, reg, live, $N, $NEXT_INSTRUCTION);
     HEAVY_SWAPIN;
diff --git a/erts/emulator/beam/msg_instrs.tab b/erts/emulator/beam/msg_instrs.tab
index 9bf3aefaca..b08466c830 100644
--- a/erts/emulator/beam/msg_instrs.tab
+++ b/erts/emulator/beam/msg_instrs.tab
@@ -105,6 +105,7 @@ i_loop_rec(Dest) {
         $SET_CP_I_ABS(I);
         c_p->arity = 0;
         c_p->current = NULL;
+        c_p->fcalls = FCALLS;
         FCALLS -= erts_proc_sig_receive_helper(c_p, FCALLS, neg_o_reds,
                                                &msgp, &get_out);
         SWAPIN;
@@ -137,8 +138,8 @@ i_loop_rec(Dest) {
 
     if (ERTS_UNLIKELY(ERTS_SIG_IS_EXTERNAL_MSG(msgp))) {
         FCALLS -= 10; /* FIXME: bump appropriate amount... */
-        SWAPOUT; /* erts_decode_dist_message() may write to heap... */
-        if (!erts_decode_dist_message(c_p, ERTS_PROC_LOCK_MAIN, msgp, 0)) {
+        SWAPOUT; /* erts_proc_sig_decode_dist() may write to heap... */
+        if (!erts_proc_sig_decode_dist(c_p, ERTS_PROC_LOCK_MAIN, msgp, 0)) {
             /*
              * A corrupt distribution message that we weren't able to decode;
              * remove it...
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index e76d896ffc..b9d4f6afcc 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -1,7 +1,7 @@
 #
 # %CopyrightBegin%
 #
-# Copyright Ericsson AB 1997-2018. All Rights Reserved.
+# Copyright Ericsson AB 1997-2019. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -74,23 +74,19 @@ trace_jump W
 
 return
 
+# To ensure that a "move Src x(0)" instruction can be combined with
+# the following call instruction, we need to make sure that there is
+# no line/1 instruction between the move and the call.
 #
-# To ensure that a "move Src x(0)" instruction can be combined
-# with the following call instruction, we need to make sure that
-# there is no line/1 instruction between the move and the call.
-#
-# A tail-recursive call to an external function (non-BIF) will
-# never be saved on the stack, so there is no reason to keep
-# the line instruction. (The compiler did not remove the line
-# instruction because it cannot tell the difference between
-# BIFs and ordinary Erlang functions.)
-#
+# A tail-recursive call to an external function (BIF or non-BIF) will
+# never be saved on the stack, so there is no reason to keep the line
+# instruction.
 
 move S X0=x==0 | line Loc | call_ext Ar Func => \
      line Loc | move S X0 | call_ext Ar Func
-move S X0=x==0 | line Loc | call_ext_last Ar Func=u$is_not_bif D => \
+move S X0=x==0 | line Loc | call_ext_last Ar Func D => \
      move S X0 | call_ext_last Ar Func D
-move S X0=x==0 | line Loc | call_ext_only Ar Func=u$is_not_bif => \
+move S X0=x==0 | line Loc | call_ext_only Ar Func => \
      move S X0 | call_ext_only Ar Func
 move S X0=x==0 | line Loc | call Ar Func => \
      line Loc | move S X0 | call Ar Func
@@ -102,15 +98,18 @@ line I
 allocate t t?
 allocate_heap t I t?
 
-%cold
+# This instruction when a BIF is called tail-recursively when
+# ther is stack frame.
 deallocate Q
-%hot
 
 init y
 allocate_zero t t?
 allocate_heap_zero t I t?
 
+move Src=y Dst=x | trim N Remaining => move_trim Src Dst N
 trim N Remaining => i_trim N
+
+move_trim y x t
 i_trim t
 
 test_heap I t?
@@ -118,11 +117,21 @@ test_heap I t?
 allocate_heap S u==0 R => allocate S R
 allocate_heap_zero S u==0 R => allocate_zero S R
 
-init2 y y
-init3 y y y
+init Y1 | init Y2 | init Y3 | succ(Y1,Y2) | succ(Y2,Y3) => init_seq3 Y1
+init_seq3 Y1 | init Y4 | succ3(Y1,Y4) => init_seq4 Y1
+init_seq4 Y1 | init Y5 | succ4(Y1,Y5) => init_seq5 Y1
+
+init_seq3 y
+init_seq4 y
+init_seq5 y
+
 init Y1 | init Y2 | init Y3 => init3 Y1 Y2 Y3
 init Y1 | init Y2 => init2 Y1 Y2
 
+init2 y y
+init3 y y y
+
+
 # Selecting values
 
 select_val S=aiq Fail=f Size=u Rest=* => const_select_val(S, Fail, Size, Rest)
@@ -205,14 +214,11 @@ set_tuple_element s S P
 
 # Get tuple element
 
-i_get_tuple_element xy P x
-
-%cold
-i_get_tuple_element xy P y
-%hot
+i_get_tuple_element xy P xy
 
 i_get_tuple_element2 x P x
-i_get_tuple_element2y x P y y
+i_get_tuple_element2_dst x P x x
+i_get_tuple_element2_dst x P y y
 
 i_get_tuple_element3 x P x
 
@@ -258,12 +264,14 @@ system_limit j
 # Move instructions.
 #
 
-move C=cxy x==0 | jump Lbl => move_jump Lbl C
+move Src=cxy Dst=xy | jump Lbl => move_jump Lbl Src Dst
 
-move_jump f ncxy
+move_jump f cxy xy
+move_jump f c r
 
-# Movement to and from the stack is common
-# Try to pack as much as we can into one instruction
+
+# Movement to and from the stack is common.
+# Try to pack as much as we can into one instruction.
 
 # Window move
 move_window/5
@@ -274,6 +282,9 @@ move_window/6
 move X1=x Y1=y | move X2=x Y2=y | move X3=x Y3=y | succ(Y1,Y2) | succ(Y2,Y3) => \
     move_window X1 X2 X3 Y1 Y3
 
+move X1=x Y1=y | move X2=x Y2=y | succ(Y1,Y2) => \
+    move_window2 X1 X2 Y1
+
 move_window X1=x X2=x X3=x Y1=y Y3=y | move X4=x Y4=y | succ(Y3,Y4) => \
     move_window X1 X2 X3 X4 Y1 Y4
 
@@ -283,15 +294,54 @@ move_window X1=x X2=x X3=x X4=x Y1=y Y4=y | move X5=x Y5=y | succ(Y4,Y5) => \
 move_window X1=x X2=x X3=x Y1=y Y3=y => move_window3 X1 X2 X3 Y1
 move_window X1=x X2=x X3=x X4=x Y1=y Y4=y => move_window4 X1 X2 X3 X4 Y1
 
+move_window2 x x y
 move_window3 x x x y
 move_window4 x x x x y
 move_window5 x x x x x y
 
+# y -> x
+
+move_src_window/4
+move_src_window/5
+
+move Y1=y X1=x | move Y2=y X2=x | succ(Y1, Y2) => \
+    move_src_window Y1 Y2 X1 X2
+
+move_src_window Y1 Y2 X1 X2 | move Y3=y X3=x | succ(Y2, Y3) => \
+    move_src_window Y1 Y3 X1 X2 X3
+move_src_window Y1 Y2 X1 X2 | move Y3=y X3=x | move Y4=y X4=x | succ(Y3, Y4) => \
+    move_src_window2 Y1 X1 X2 | move_src_window Y3 Y4 X3 X4
+move_src_window Y1 Y2 X1 X2 | move Y3=y X3=x => \
+    move3 Y1 X1 Y2 X2 Y3 X3
+
+move_src_window Y1 Y3 X1 X2 X3 | move Y4=y X4=x | succ(Y3, Y4) => \
+    move_src_window4 Y1 X1 X2 X3 X4
+
+move_src_window Y1 y X1 X2    => move_src_window2 Y1 X1 X2
+move_src_window Y1 y X1 X2 X3 => move_src_window3 Y1 X1 X2 X3
+
+move_src_window2 y x x
+move_src_window3 y x x x
+move_src_window4 y x x x x
+
 # Swap registers.
-move R1=x Tmp=x | move R2=xy R1 | move Tmp R2 => swap_temp R1 R2 Tmp
+move R1=xy Tmp=x | move R2=xy R1 | move Tmp R2 => swap_temp R1 R2 Tmp
+
+# The compiler uses x(1022) when swapping registers. It will definitely
+# not be used again.
+swap_temp R1 R2 Tmp=x==1022 => swap R1 R2
+
+swap_temp R1 R2 Tmp | move Src Tmp => swap R1 R2 | move Src Tmp
 
 swap_temp R1 R2 Tmp | line Loc | apply Live | is_killed_apply(Tmp, Live) => \
   swap R1 R2 | line Loc | apply Live
+swap_temp R1 R2 Tmp | line Loc | apply_last Live D | is_killed_apply(Tmp, Live) => \
+  swap R1 R2 | line Loc | apply_last Live D
+
+swap_temp R1 R2 Tmp | line Loc | call_fun Live | is_killed_by_call_fun(Tmp, Live) => \
+  swap R1 R2 | line Loc | call_fun Live
+swap_temp R1 R2 Tmp | make_fun2 OldIndex=u | is_killed_by_make_fun(Tmp, OldIndex) => \
+  swap R1 R2 | make_fun2 OldIndex
 
 swap_temp R1 R2 Tmp | line Loc | call Live Addr | is_killed(Tmp, Live) => \
   swap R1 R2 | line Loc | call Live Addr
@@ -307,84 +357,112 @@ swap_temp R1 R2 Tmp | line Loc | call_ext_only Live Addr | \
 swap_temp R1 R2 Tmp | line Loc | call_ext_last Live Addr D | \
   is_killed(Tmp, Live) => swap R1 R2 | line Loc | call_ext_last Live Addr D
 
-swap_temp x xy x
+swap_temp R1 R2 Tmp | call_ext Live Addr | is_killed(Tmp, Live) => \
+  swap R1 R2 | call_ext Live Addr
+swap_temp R1 R2 Tmp | call_ext_only Live Addr | is_killed(Tmp, Live) => \
+  swap R1 R2 | call_ext_only Live Addr
+swap_temp R1 R2 Tmp | call_ext_last Live Addr D | is_killed(Tmp, Live) => \
+  swap R1 R2 | call_ext_last Live Addr D
+
+swap_temp R1 R2 Tmp | move Src Any | line Loc | call Live Addr | \
+  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
+     swap R1 R2 | move Src Any | line Loc | call Live Addr
+swap_temp R1 R2 Tmp | move Src Any | line Loc | call_ext Live Addr | \
+  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
+     swap R1 R2 | move Src Any | line Loc | call_ext Live Addr
+swap_temp R1 R2 Tmp | move Src Any | call_only Live Addr | \
+  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
+    swap R1 R2 | move Src Any | call_only Live Addr
+swap_temp R1 R2 Tmp | move Src Any | line Loc | call_ext_only Live Addr | \
+  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
+    swap R1 R2 | move Src Any | line Loc | call_ext_only Live Addr
+swap_temp R1 R2 Tmp | move Src Any | line Loc | call_fun Live | \
+  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
+    swap R1 R2 | move Src Any | line Loc | call_fun Live
+
+swap_temp R1 R2 Tmp | line Loc | send | is_killed_by_send(Tmp) => \
+  swap R1 R2 | line Loc | send
+
+# swap_temp/3 with Y register operands are rare.
+swap_temp R1 R2=y Tmp => swap R1 R2 | move R2 Tmp
+swap_temp R1=y R2 Tmp => swap R1 R2 | move R2 Tmp
+
+swap R1=x R2=y => swap R2 R1
+
+swap_temp x x x
+
+swap xy x
+swap y y
+
+# move_shift
+
+move SD=x    D=x | move Src=cxy SD=x  | distinct(D, Src) => move_shift Src SD D
+move SD=y    D=x | move Src=x  SD=y   | distinct(D, Src) => move_shift Src SD D
+move SD=y    D=x | init SD            |                  => move_shift n   SD D
+move SD=x    D=y | move Src=x  SD=x   | distinct(D, Src) => move_shift Src SD D
+move SD=x==0 D=y | move Src=y SD=x==0 | distinct(D, Src) => move_shift Src SD D
+
+move_shift cxy x x
+move_shift nx y x
+move_shift x x y
+move_shift y r y
+
+# move2_par x x x x
 
-swap x xy
+move X1=x X2=x | move X3=x X4=x | independent_moves(X1, X2, X3, X4) => \
+     move2_par X1 X2 X3 X4
+move2_par x x x x
 
-move Src=x D1=x | move Src=x D2=x => move_dup Src D1 D2
-move Src=x SD=x | move SD=x D=x   => move_dup Src SD D
-move Src=x D1=x | move Src=x D2=y => move_dup Src D1 D2
-move Src=y SD=x | move SD=x D=y   => move_dup Src SD D
-move Src=x SD=x | move SD=x D=y   => move_dup Src SD D
-move Src=y SD=x | move SD=x D=x   => move_dup Src SD D
+# move2_par x x x y
 
-move SD=x D=x | move Src=xy SD=x => move_shift Src SD D
-move SD=y D=x | move Src=x  SD=y => move_shift Src SD D
-move SD=x D=y | move Src=x  SD=x => move_shift Src SD D
+move X1=x X2=x | move X3=x Y1=y | independent_moves(X1, X2, X3, Y1) => \
+     move2_par X1 X2 X3 Y1
+move X3=x Y1=y | move X1=x X2=x | independent_moves(X3, Y1, X1, X2) => \
+     move2_par X1 X2 X3 Y1
+move2_par x x x y
 
-# The transformations above guarantee that the source for
-# the second move is not the same as the destination for
-# the first move. That means that we can do the moves in
-# parallel (fetch both values, then store them) which could
-# be faster.
+# move2_par y x y x
 
-move X1=x Y1=y | move X2=x Y2=y => move2_par X1 Y1 X2 Y2
 move Y1=y X1=x | move Y2=y X2=x => move2_par Y1 X1 Y2 X2
+move2_par y x y x
 
-move X1=x X2=x | move X3=x X4=x => move2_par X1 X2 X3 X4
+# move2_par y x x y
 
-move X1=x X2=x | move X3=x Y1=y => move2_par X1 X2 X3 Y1
+move S1=y S2=x | move X1=x Y1=y | independent_moves(S1, S2, X1, Y1) => \
+     move2_par S1 S2 X1 Y1
+move X1=x Y1=y | move S1=y S2=x | independent_moves(S1, S2, X1, Y1) => \
+     move2_par S1 S2 X1 Y1
+move2_par y x x y
 
-move S1=x S2=x | move X1=x Y1=y => move2_par S1 S2 X1 Y1
+# move2_par y x x x
 
-move S1=y S2=x | move X1=x Y1=y => move2_par S1 S2 X1 Y1
+move Y1=y X1=x | move S1=x D1=x | independent_moves(Y1, X1, S1, D1) => \
+     move2_par Y1 X1 S1 D1
+move S1=x D1=x | move Y1=y X1=x | independent_moves(Y1, X1, S1, D1) => \
+     move2_par Y1 X1 S1 D1
+move2_par y x x x
 
-move Y1=y X1=x | move S1=x D1=x => move2_par Y1 X1 S1 D1
-move S1=x D1=x | move Y1=y X1=x => move2_par S1 D1 Y1 X1
+# move3
 
-move2_par X1=x Y1=y X2=x Y2=y | move X3=x Y3=y => move3 X1 Y1 X2 Y2 X3 Y3
 move2_par Y1=y X1=x Y2=y X2=x | move Y3=y X3=x => move3 Y1 X1 Y2 X2 Y3 X3
 move2_par X1=x X2=x X3=x X4=x | move X5=x X6=x => move3 X1 X2 X3 X4 X5 X6
 
+move3 y x y x y x
+move3 x x x x x x
+
+# move_x1, move_x2
+
 move C=aiq X=x==1 => move_x1 C
 move C=aiq X=x==2 => move_x2 C
 
+move n D=y => init D
+
 move_x1 c
 move_x2 c
 
-move_shift x x x
-move_shift y x x
-move_shift x y x
-move_shift x x y
-
-move_dup xy x xy
-
-move2_par x y x y
-move2_par y x y x
-move2_par x x x x
-
-move2_par x x x y
-
-move2_par y x x y
-
-move2_par x x y x
-move2_par y x x x
-
-move3 x y x y x y
-move3 y x y x y x
-move3 x x x x x x
-
-# The compiler almost never generates a "move Literal y(Y)" instruction,
-# so let's cheat if we encounter one.
-move S=n D=y => init D
-move S=c D=y => move S x | move x D
-
-move x x
-move x y
-move y x
-move c x
+move xy xy
+move c xy
 move n x
-move y y
 
 # The following move instructions using x(0) are frequently used.
 
@@ -478,14 +556,25 @@ is_ge f? c x
 is_ge f? s s
 %hot
 
-is_eq f? s s
+is_eq Fail=f Const=c Reg=xy => is_eq Fail Reg Const
+is_eq Fail=f C1=c C2=c => move C1 x | is_eq Fail x C2
+is_eq f? S s
 
-is_ne f? s s
+is_ne Fail=f Const=c Reg=xy => is_ne Fail Reg Const
+is_ne Fail=f C1=c C2=c => move C1 x | is_ne Fail x C2
+is_ne f? S s
 
 #
-# Putting things.
+# Putting tuples.
+#
+# Code compiled with OTP 22 and later uses put_tuple2 to
+# to construct a tuple.
+#
+# Code compiled before OTP 22 uses put_tuple + one put instruction
+# per element. Translate to put_tuple2.
 #
 
+i_put_tuple/2
 put_tuple Arity Dst => i_put_tuple Dst u
 
 i_put_tuple Dst Arity Puts=* | put S1 | put S2 | \
@@ -495,11 +584,13 @@ i_put_tuple Dst Arity Puts=* | put S1 | put S2 | \
 i_put_tuple Dst Arity Puts=* | put S => \
 	    tuple_append_put(Arity, Dst, Puts, S)
 
-i_put_tuple/2
+i_put_tuple Dst Arity Puts=* => put_tuple2 Dst Arity Puts
 
-i_put_tuple xy I
+put_tuple2 xy I
 
 #
+# Putting lists.
+#
 # The instruction "put_list Const [] Dst" were generated in rare
 # circumstances up to and including OTP 18. Starting with OTP 19,
 # AFAIK, it should never be generated.
@@ -510,32 +601,26 @@ put_list Src Dst=x Dst => update_list Src Dst
 
 update_list xyc x
 
-put_list x n x
-put_list y n x
-put_list x x x
-put_list y x x
+# put_list SrcReg1 SrcReg2 => Dst
+
+put_list xy xy x
 
-put_list y y x
-put_list x y x
+# put_list SrcReg [] => Dst
 
-# put_list SrcReg Constant Dst
+put_list xy n xy
 
-put_list x c x
-put_list x c y
+# put_list SrcReg Constant => x
 
-put_list y c x
+put_list xy c x
 
-# put_list Constant SrcReg Dst
+# put_list Constant SrcReg => Dst
 
-put_list c x x
-put_list c y x
+put_list c xy x
 
 # The following put_list instructions using x(0) are frequently used.
 
-put_list r n r
-put_list r n x
-put_list r x x
-put_list r x r
+put_list r n rx
+put_list r x rx
 put_list x x r
 
 %cold
@@ -602,19 +687,36 @@ is_tuple f? rxy
 
 test_arity Fail Literal=q Arity => move Literal x | test_arity Fail x Arity
 test_arity Fail=f c Arity => jump Fail
+test_arity Fail Tuple=x Arity | get_tuple_element Tuple Pos Dst=x => \
+   test_arity_get_tuple_element Fail Tuple Arity Pos Dst
 
 test_arity f? xy A
 
-get_tuple_element Reg=x P1 D1=x | get_tuple_element Reg=x P2 D2=x | \
+test_arity_get_tuple_element f? x A P x
+
+is_tuple NotTupleFail Tuple=x | is_tagged_tuple WrongRecordFail Tuple Arity Atom => \
+   is_tagged_tuple_ff NotTupleFail WrongRecordFail Tuple Arity Atom
+
+is_tagged_tuple_ff f? f? rx A a
+
+get_tuple_element Reg=x P1 D1=x | \
+   get_tuple_element Reg=x P2 D2=x | \
    get_tuple_element Reg=x P3 D3=x | \
-   succ(P1, P2) | succ(P2, P3) | \
-   succ(D1, D2) | succ(D2, D3) => i_get_tuple_element3 Reg P1 D1
+   succ(P1, P2) | succ(P2, P3) | succ(D1, D2) | succ(D2, D3) | \
+   distinct(D1, Reg) | distinct(D2, Reg) => \
+      i_get_tuple_element3 Reg P1 D1
+
+get_tuple_element Reg=x P1 D1=x | \
+   get_tuple_element Reg=x P2 D2=x | \
+   succ(P1, P2) | succ(D1, D2) | \
+   distinct(D1, Reg) => \
+      i_get_tuple_element2 Reg P1 D1
 
 get_tuple_element Reg=x P1 D1=x | get_tuple_element Reg=x P2 D2=x | \
-   succ(P1, P2) | succ(D1, D2) => i_get_tuple_element2 Reg P1 D1
+   succ(P1, P2) | distinct(D1, Reg) => i_get_tuple_element2_dst Reg P1 D1 D2
 
 get_tuple_element Reg=x P1 D1=y | get_tuple_element Reg=x P2 D2=y | \
-   succ(P1, P2) => i_get_tuple_element2y Reg P1 D1 D2
+   succ(P1, P2) => i_get_tuple_element2_dst Reg P1 D1 D2
 
 get_tuple_element Reg P Dst => i_get_tuple_element Reg P Dst
 
@@ -638,14 +740,21 @@ is_list f? y
 
 is_nonempty_list Fail=f S=x | allocate Need Rs => is_nonempty_list_allocate Fail S Need Rs
 
-is_nonempty_list F=f x==0 | test_heap I1 I2 => is_nonempty_list_test_heap F I1 I2
-
 is_nonempty_list Fail=f S=x | get_list S D1=x D2=x => \
   is_nonempty_list_get_list Fail S D1 D2
 
+is_nonempty_list Fail=f S=x | get_hd S Dst=x => \
+  is_nonempty_list_get_hd Fail S Dst
+
+is_nonempty_list Fail=f S=x | get_tl S Dst=x => \
+  is_nonempty_list_get_tl Fail S Dst
+
 is_nonempty_list_allocate f? rx t t
-is_nonempty_list_test_heap f? I t
+
 is_nonempty_list_get_list f? rx x x
+is_nonempty_list_get_hd f? x x
+is_nonempty_list_get_tl f? x x
+
 is_nonempty_list f? xy
 
 is_atom f? x
@@ -710,11 +819,12 @@ is_boolean Fail=f ac => jump Fail
 is_boolean f? xy
 %hot
 
-is_function2 Fail=f Literal=q Arity | literal_is_export(Literal) =>
-is_function2 Fail=f c Arity => jump Fail
-is_function2 Fail=f Fun a => jump Fail
+is_function2 Fail=f Fun Arity => gen_is_function2(Fail, Fun, Arity)
 
-is_function2 f? S s
+%cold
+cold_is_function2 f? x x
+%hot
+hot_is_function2 f? S t
 
 # Allocating & initializing.
 allocate Need Regs | init Y => allocate_init Need Regs Y
@@ -946,10 +1056,9 @@ call_ext_only u==0 u$func:os:perf_counter/0 => \
 
 call_ext u Bif=u$is_bif => call_bif Bif
 
-call_ext_last u Bif=u$is_bif D => call_bif Bif | deallocate_return D
+call_ext_last u Bif=u$is_bif D => deallocate D | call_bif_only Bif
 
-call_ext_only Ar=u Bif=u$is_bif => \
-  allocate u Ar | call_bif Bif | deallocate_return u
+call_ext_only Ar=u Bif=u$is_bif => call_bif_only Bif
 
 #
 # Any remaining calls are calls to Erlang functions, not BIFs.
@@ -981,6 +1090,7 @@ i_perf_counter
 %hot
 
 call_bif e
+call_bif_only e
 
 #
 # Calls to non-building and guard BIFs.
@@ -989,14 +1099,18 @@ call_bif e
 bif0 u$bif:erlang:self/0 Dst=d => self Dst
 bif0 u$bif:erlang:node/0 Dst=d => node Dst
 
+bif1 Fail=f Bif=u$bif:erlang:hd/1 Src=x Dst=x => is_nonempty_list_get_hd Fail Src Dst
+bif1 Fail=f Bif=u$bif:erlang:tl/1 Src=x Dst=x => is_nonempty_list_get_tl Fail Src Dst
+
 bif1 Fail Bif=u$bif:erlang:get/1 Src=s Dst=d => gen_get(Src, Dst)
 
 bif2 Jump=j u$bif:erlang:element/2 S1=s S2=xy Dst=d => gen_element(Jump, S1, S2, Dst)
 
-bif1 p Bif S1 Dst => bif1_body Bif S1 Dst
+bif1 p Bif S1 Dst         => i_bif1_body S1 Bif Dst
+bif1 Fail=f Bif S1 Dst    => i_bif1 S1 Fail Bif Dst
 
-bif2 p Bif S1 S2 Dst => i_bif2_body Bif S1 S2 Dst
-bif2 Fail Bif S1 S2 Dst => i_bif2 Fail Bif S1 S2 Dst
+bif2 p Bif S1 S2 Dst      => i_bif2_body S2 S1 Bif Dst
+bif2 Fail=f Bif S1 S2 Dst => i_bif2 S2 S1 Fail Bif Dst
 
 i_get_hash c I d
 i_get s d
@@ -1014,10 +1128,12 @@ i_fast_element xy j? I d
 
 i_element xy j? s d
 
-bif1 f? b s d
-bif1_body b s d
-i_bif2 f? b s s d
-i_bif2_body b s s d
+i_bif1 s f? b d
+i_bif1_body s b d
+i_bif2 s s f? b d
+i_bif2_body s s b d
+i_bif3 s s s f? b d
+i_bif3_body s s s b d
 
 #
 # Internal calls.
@@ -1062,8 +1178,25 @@ call_fun Arity => i_call_fun Arity
 i_call_fun t
 i_call_fun_last t Q
 
+
+#
+# A fun with an empty environment can be converted to a literal.
+# As a further optimization, the we try to move the fun to its
+# final destination directly.
+
 make_fun2 OldIndex=u => gen_make_fun2(OldIndex)
 
+move_fun/2
+move_fun Fun X0 | move X0 Dst | move Src X0 => move Fun Dst | move Src X0
+move_fun Fun X0 | move A B | move X0 Dst | move Src X0 | \
+  independent_moves(Fun, X0, A, B) | distinct(Dst, A) => \
+    move Fun Dst | move A B | move Src X0
+move_fun Fun X0 | move X0 Dst | make_fun2 OldIndex | \
+  is_killed_by_make_fun(X0, OldIndex)=> \
+    move Fun Dst | make_fun2 OldIndex
+
+move_fun Fun Dst => move Fun Dst
+
 %cold
 i_make_fun W t
 %hot
@@ -1074,101 +1207,141 @@ is_function Fail=f c => jump Fail
 func_info M F A => i_func_info u M F A
 
 # ================================================================
-# New bit syntax matching (R11B).
+# Bit syntax matching obsoleted in OTP 22.
 # ================================================================
 
-%warm
+%cold
 bs_start_match2 Fail=f ica X Y D => jump Fail
 bs_start_match2 Fail Bin X Y D => i_bs_start_match2 Bin Fail X Y D
-i_bs_start_match2 xy f t t x
+i_bs_start_match2 xy f t t d
 
+bs_save2 Y=y Index => move Y x | bs_save2 x Index
 bs_save2 Reg Index => gen_bs_save(Reg, Index)
 i_bs_save2 x t
 
+bs_restore2 Y=y Index => move Y x | bs_restore2 x Index
 bs_restore2 Reg Index => gen_bs_restore(Reg, Index)
 i_bs_restore2 x t
 
+bs_context_to_binary Y=y | line L | badmatch Y => \
+    move Y x | bs_context_to_binary x | line L | badmatch x
+bs_context_to_binary Y=y => move Y x | bs_context_to_binary x
+bs_context_to_binary x
+%warm
+
+# ================================================================
+# New bit syntax matching (R11B).
+# ================================================================
+
+%warm
+
 # Matching integers
 bs_match_string Fail Ms Bits Val => i_bs_match_string Ms Fail Bits Val
 
-i_bs_match_string x f W W
+i_bs_match_string xy f W W
 
 # Fetching integers from binaries.
-bs_get_integer2 Fail=f Ms=x Live=u Sz=sq Unit=u Flags=u Dst=d => \
+bs_get_integer2 Fail=f Ms=xy Live=u Sz=sq Unit=u Flags=u Dst=d => \
 			gen_get_integer2(Fail, Ms, Live, Sz, Unit, Flags, Dst)
 
-i_bs_get_integer_small_imm x W f? t x
-i_bs_get_integer_imm x W t f? t x
-i_bs_get_integer f? t t x s x
-i_bs_get_integer_8 x f? x
-i_bs_get_integer_16 x f? x
+i_bs_get_integer_small_imm Ms Bits Fail Flags Y=y => \
+   i_bs_get_integer_small_imm Ms Bits Fail Flags x | move x Y
+
+i_bs_get_integer_imm Ms Bits Live Fail Flags Y=y => \
+   i_bs_get_integer_imm Ms Bits Live Fail Flags x | move x Y
+
+i_bs_get_integer_small_imm xy W f? t x
+i_bs_get_integer_imm xy W t f? t x
+i_bs_get_integer xy f? t t s d
+i_bs_get_integer_8 xy f? d
+i_bs_get_integer_16 xy f? d
 
 %if ARCH_64
-i_bs_get_integer_32 x f? x
+i_bs_get_integer_32 xy f? d
 %endif
 
 # Fetching binaries from binaries.
-bs_get_binary2 Fail=f Ms=x Live=u Sz=sq Unit=u Flags=u Dst=d => \
+bs_get_binary2 Fail=f Ms=xy Live=u Sz=sq Unit=u Flags=u Dst=d => \
 			gen_get_binary2(Fail, Ms, Live, Sz, Unit, Flags, Dst)
 
-i_bs_get_binary_imm2 f? x t W t x
-i_bs_get_binary2 f x t? s t x
-i_bs_get_binary_all2 f? x t t x
-i_bs_get_binary_all_reuse x f? t
+i_bs_get_binary_imm2 xy f? t W t d
+i_bs_get_binary2 xy f t? s t d
+i_bs_get_binary_all2 xy f? t t d
 
 # Fetching float from binaries.
-bs_get_float2 Fail=f Ms=x Live=u Sz=s Unit=u Flags=u Dst=d => \
+bs_get_float2 Fail=f Ms=xy Live=u Sz=s Unit=u Flags=u Dst=d => \
 		gen_get_float2(Fail, Ms, Live, Sz, Unit, Flags, Dst)
 
 bs_get_float2 Fail=f Ms=x Live=u Sz=q Unit=u Flags=u Dst=d => jump Fail
 
-i_bs_get_float2 f? x t s t x
+i_bs_get_float2 xy f? t s t d
 
 # Miscellanous
 
-bs_skip_bits2 Fail=f Ms=x Sz=sq Unit=u Flags=u => \
+bs_skip_bits2 Fail=f Ms=xy Sz=sq Unit=u Flags=u => \
 			gen_skip_bits2(Fail, Ms, Sz, Unit, Flags)
 
-i_bs_skip_bits_imm2 f? x W
-i_bs_skip_bits2 f? x xy t
-i_bs_skip_bits_all2 f? x t
+i_bs_skip_bits_imm2 f? xy W
+i_bs_skip_bits2 xy xy f? t
 
-bs_test_tail2 Fail=f Ms=x Bits=u==0 => bs_test_zero_tail2 Fail Ms
-bs_test_tail2 Fail=f Ms=x Bits=u => bs_test_tail_imm2 Fail Ms Bits
-bs_test_zero_tail2 f? x
-bs_test_tail_imm2 f? x W
+bs_test_tail2 Fail=f Ms=xy Bits=u==0 => bs_test_zero_tail2 Fail Ms
+bs_test_tail2 Fail=f Ms=xy Bits=u => bs_test_tail_imm2 Fail Ms Bits
+bs_test_zero_tail2 f? xy
+bs_test_tail_imm2 f? xy W
 
 bs_test_unit F Ms Unit=u==8 => bs_test_unit8 F Ms
-bs_test_unit f? x t
-bs_test_unit8 f? x
+bs_test_unit f? xy t
+bs_test_unit8 f? xy
 
-# An y register operand for bs_context_to_binary is rare,
-# but can happen because of inlining.
+# Gets a bitstring from the tail of a context.
+bs_get_tail xy d t
 
-bs_context_to_binary Y=y | line L | badmatch Y => \
-    move Y x | bs_context_to_binary x | line L | badmatch x
+# New bs_start_match variant for contexts with external position storage.
+#
+# bs_get/set_position is used to save positions into registers instead of
+# "slots" in the context itself, which lets us continue matching even after
+# we've passed it off to another function.
 
-bs_context_to_binary Y=y => move Y x | bs_context_to_binary x
+%if ARCH_64
+bs_start_match3 Fail Bin Live Ctx | bs_get_position Ctx Pos=x Ignored => \
+    i_bs_start_match3_gp Bin Live Fail Ctx Pos
+i_bs_start_match3_gp xy t f d x
+%endif
 
-bs_context_to_binary x
+bs_start_match3 Fail=f ica Live Dst => jump Fail
+bs_start_match3 Fail Bin Live Dst => i_bs_start_match3 Bin Live Fail Dst
+
+i_bs_start_match3 xy t f d
+
+# Match context position instructions. 64-bit assumes that all positions can
+# fit into an unsigned small.
+
+%if ARCH_64
+    bs_get_position Src Dst Live => i_bs_get_position Src Dst
+    i_bs_get_position xy xy
+    bs_set_position xy xy
+%else
+    bs_get_position xy d t?
+    bs_set_position xy xy
+%endif
 
 #
 # Utf8/utf16/utf32 support. (R12B-5)
 #
-bs_get_utf8 Fail=f Ms=x u u Dst=d => i_bs_get_utf8 Ms Fail Dst
-i_bs_get_utf8 x f? x
+bs_get_utf8 Fail=f Ms=xy u u Dst=d => i_bs_get_utf8 Ms Fail Dst
+i_bs_get_utf8 xy f? d
 
-bs_skip_utf8 Fail=f Ms=x u u => i_bs_get_utf8 Ms Fail x
+bs_skip_utf8 Fail=f Ms=xy u u => i_bs_get_utf8 Ms Fail x
 
-bs_get_utf16 Fail=f Ms=x u Flags=u Dst=d => i_bs_get_utf16 Ms Fail Flags Dst
-bs_skip_utf16 Fail=f Ms=x u Flags=u => i_bs_get_utf16 Ms Fail Flags x
+bs_get_utf16 Fail=f Ms=xy u Flags=u Dst=d => i_bs_get_utf16 Ms Fail Flags Dst
+bs_skip_utf16 Fail=f Ms=xy u Flags=u => i_bs_get_utf16 Ms Fail Flags x
 
-i_bs_get_utf16 x f? t x
+i_bs_get_utf16 xy f? t d
 
-bs_get_utf32 Fail=f Ms=x Live=u Flags=u Dst=d => \
+bs_get_utf32 Fail=f Ms=xy Live=u Flags=u Dst=d => \
 	bs_get_integer2 Fail Ms Live i=32 u=1 Flags Dst | \
 	i_bs_validate_unicode_retract Fail Dst Ms
-bs_skip_utf32 Fail=f Ms=x Live=u Flags=u => \
+bs_skip_utf32 Fail=f Ms=xy Live=u Flags=u => \
 	bs_get_integer2 Fail Ms Live i=32 u=1 Flags x | \
 	i_bs_validate_unicode_retract Fail x Ms
 
@@ -1182,6 +1355,9 @@ i_bs_validate_unicode_retract j s S
 
 bs_init2 Fail Sz Words Regs Flags Dst | binary_too_big(Sz) => system_limit Fail
 
+bs_init2 Fail Sz Words Regs Flags Dst=y => \
+   bs_init2 Fail Sz Words Regs Flags x | move x Dst
+
 bs_init2 Fail Sz=u Words=u==0 Regs Flags Dst => i_bs_init Sz Regs Dst
 
 bs_init2 Fail Sz=u Words Regs Flags Dst => \
@@ -1202,6 +1378,8 @@ i_bs_init_heap W I t? x
 
 
 bs_init_bits Fail Sz=o Words Regs Flags Dst => system_limit Fail
+bs_init_bits Fail Sz Words Regs Flags Dst=y => \
+   bs_init_bits Fail Sz Words Regs Flags x | move x Dst
 
 bs_init_bits Fail Sz=u Words=u==0 Regs Flags Dst => i_bs_init_bits Sz Regs Dst
 bs_init_bits Fail Sz=u Words Regs Flags Dst =>  i_bs_init_bits_heap Sz Words Regs Dst
@@ -1230,7 +1408,7 @@ bs_private_append Fail Size Unit Bin Flags Dst => \
 
 bs_init_writable
 
-i_bs_append j? I t? t s x
+i_bs_append j? I t? t s xy
 i_bs_private_append j? t s S x
 
 #
@@ -1240,31 +1418,35 @@ i_bs_private_append j? t s S x
 bs_put_integer Fail=j Sz=sq Unit=u Flags=u Src=s => \
 			gen_put_integer(Fail, Sz, Unit, Flags, Src)
 
-i_new_bs_put_integer j? s t s
-i_new_bs_put_integer_imm j? W t s
+i_new_bs_put_integer j? S t s
+i_new_bs_put_integer_imm xyc j? W t
 
 #
 # Utf8/utf16/utf32 support. (R12B-5)
 #
 
-bs_utf8_size j Src=s Dst=d => i_bs_utf8_size Src Dst
+bs_utf8_size j Src Dst=d => i_bs_utf8_size Src Dst
+bs_utf16_size j Src Dst=d => i_bs_utf16_size Src Dst
 
-i_bs_utf8_size s x
+bs_put_utf8 Fail u Src => i_bs_put_utf8 Fail Src
 
-bs_utf16_size j Src=s Dst=d => i_bs_utf16_size Src Dst
-
-i_bs_utf16_size s x
-
-bs_put_utf8 Fail u Src=s => i_bs_put_utf8 Fail Src
+bs_put_utf32 Fail=j Flags=u Src=s => \
+   i_bs_validate_unicode Fail Src | bs_put_integer Fail i=32 u=1 Flags Src
 
-i_bs_put_utf8 j? s
+i_bs_utf8_size S x
+i_bs_utf16_size S x
 
-bs_put_utf16 j? t s
+i_bs_put_utf8 j? S
+bs_put_utf16 j? t S
 
-bs_put_utf32 Fail=j Flags=u Src=s => \
-   i_bs_validate_unicode Fail Src | bs_put_integer Fail i=32 u=1 Flags Src
+i_bs_validate_unicode j? S
 
-i_bs_validate_unicode j? s
+# Handle unoptimized code.
+i_bs_utf8_size Src=c Dst => move Src x | i_bs_utf8_size x Dst
+i_bs_utf16_size Src=c Dst => move Src x | i_bs_utf16_size x Dst
+i_bs_put_utf8 Fail Src=c => move Src x | i_bs_put_utf8 Fail x
+bs_put_utf16 Fail Flags Src=c => move Src x | bs_put_utf16 Fail Flags x
+i_bs_validate_unicode Fail Src=c => move Src x | i_bs_validate_unicode Fail x
 
 #
 # Storing floats into binaries.
@@ -1274,7 +1456,7 @@ bs_put_float Fail Sz=q Unit Flags Val => badarg Fail
 bs_put_float Fail=j Sz=s Unit=u Flags=u Src=s => \
 			gen_put_float(Fail, Sz, Unit, Flags, Src)
 
-i_new_bs_put_float j? s t s
+i_new_bs_put_float j? S t s
 i_new_bs_put_float_imm j? W t s
 
 #
@@ -1284,9 +1466,18 @@ i_new_bs_put_float_imm j? W t s
 bs_put_binary Fail=j Sz=s Unit=u Flags=u Src=s => \
 			gen_put_binary(Fail, Sz, Unit, Flags, Src)
 
-i_new_bs_put_binary j? s t s
-i_new_bs_put_binary_imm j? W s
-i_new_bs_put_binary_all j? s t
+# In unoptimized code, the binary argument could be a literal. (In optimized code,
+# there would be a bs_put_string instruction.)
+i_new_bs_put_binary Fail Size Unit Lit=c => \
+   move Lit x | i_new_bs_put_binary Fail Size Unit x
+i_new_bs_put_binary_imm Fail Size Lit=c => \
+   move Lit x | i_new_bs_put_binary_imm Fail Size x
+i_new_bs_put_binary_all Lit=c Fail Unit => \
+   move Lit x | i_new_bs_put_binary_all x Fail Unit
+
+i_new_bs_put_binary j? S t S
+i_new_bs_put_binary_imm j? W S
+i_new_bs_put_binary_all xy j? t
 
 #
 # Warning: The i_bs_put_string and i_new_bs_put_string instructions
@@ -1384,23 +1575,22 @@ put_map_exact F Map Dst Live Size Rest=* | map_key_sort(Size, Rest) => \
 
 sorted_put_map_assoc Map Dst Live Size Rest=* | is_empty_map(Map) => \
    new_map Dst Live Size Rest
-sorted_put_map_assoc Src=s Dst Live Size Rest=* => \
-	       update_map_assoc Src Dst Live Size Rest
-sorted_put_map_assoc Src Dst Live Size Rest=* => \
-	       move Src x | update_map_assoc x Dst Live Size Rest
+sorted_put_map_assoc Src=xyc Dst Live Size Rest=* => \
+   update_map_assoc Src Dst Live Size Rest
 
-sorted_put_map_exact F Src=s Dst Live Size Rest=* => \
-	      update_map_exact F Src Dst Live Size Rest
-sorted_put_map_exact F Src Dst Live Size Rest=* => \
-	      move Src x | update_map_exact F x Dst Live Size Rest
+sorted_put_map_exact Fail Src=xy Dst Live Size Rest=* => \
+   update_map_exact Src Fail Dst Live Size Rest
+# Literal map arguments for an exact update operation are extremely rare.
+sorted_put_map_exact Fail Src Dst Live Size Rest=* => \
+   move Src x | update_map_exact x Fail Dst Live Size Rest
 
 new_map Dst Live Size Rest=* | is_small_map_literal_keys(Size, Rest) => \
    gen_new_small_map_lit(Dst, Live, Size, Rest)
 
 new_map d t I
 i_new_small_map_lit d t q
-update_map_assoc s d t I
-update_map_exact j? s d t I
+update_map_assoc xyc d t I
+update_map_exact xy j? d t I
 
 is_map Fail Lit=q | literal_is_map(Lit) =>
 is_map Fail cq => jump Fail
@@ -1447,80 +1637,94 @@ gc_bif2 Fail Live u$bif:erlang:sminus/2 S1 S2 Dst => \
 
 #
 # Optimize addition and subtraction of small literals using
-# the i_increment/4 instruction (in bodies, not in guards).
+# the i_increment/3 instruction (in bodies, not in guards).
 #
 
 gen_plus p Live Int=i Reg=d Dst => \
-	gen_increment(Reg, Int, Live, Dst)
+	gen_increment(Reg, Int, Dst)
 gen_plus p Live Reg=d Int=i Dst => \
-	gen_increment(Reg, Int, Live, Dst)
+	gen_increment(Reg, Int, Dst)
 
 gen_minus p Live Reg=d Int=i Dst | negation_is_small(Int) => \
-	gen_increment_from_minus(Reg, Int, Live, Dst)
+	gen_increment_from_minus(Reg, Int, Dst)
 
 #
-# GCing arithmetic instructions.
+# Arithmetic instructions.
 #
 
-gen_plus Fail Live S1 S2 Dst => i_plus S1 S2 Fail Live Dst
+# It is OK to swap arguments for '+' in a guard. It is also
+# OK to turn minus into plus in a guard.
+gen_plus Fail=f Live S1=c S2 Dst => i_plus S2 S1 Fail Dst
+gen_minus Fail=f Live S1 S2=i Dst => gen_plus_from_minus(Fail, Live, S1, S2, Dst)
+
+gen_plus Fail Live S1 S2 Dst => i_plus S1 S2 Fail Dst
 
-gen_minus Fail Live S1 S2 Dst => i_minus S1 S2 Fail Live Dst
+gen_minus Fail Live S1 S2 Dst => i_minus S1 S2 Fail Dst
 
 gc_bif2 Fail Live u$bif:erlang:stimes/2 S1 S2 Dst => \
-  i_times Fail Live S1 S2 Dst
+  i_times Fail S1 S2 Dst
 
 gc_bif2 Fail Live u$bif:erlang:div/2 S1 S2 Dst => \
-  i_m_div Fail Live S1 S2 Dst
+  i_m_div Fail S1 S2 Dst
 gc_bif2 Fail Live u$bif:erlang:intdiv/2 S1 S2 Dst => \
-  i_int_div Fail Live S1 S2 Dst
+  i_int_div Fail S1 S2 Dst
 
 gc_bif2 Fail Live u$bif:erlang:rem/2 S1 S2 Dst => \
-  i_rem S1 S2 Fail Live Dst
+  i_rem S1 S2 Fail Dst
 
 gc_bif2 Fail Live u$bif:erlang:bsl/2 S1 S2 Dst => \
-  i_bsl S1 S2 Fail Live Dst
+  i_bsl S1 S2 Fail Dst
 gc_bif2 Fail Live u$bif:erlang:bsr/2 S1 S2 Dst => \
-  i_bsr S1 S2 Fail Live Dst
+  i_bsr S1 S2 Fail Dst
 
 gc_bif2 Fail Live u$bif:erlang:band/2 S1 S2 Dst => \
-  i_band S1 S2 Fail Live Dst
+  i_band S1 S2 Fail Dst
 
 gc_bif2 Fail Live u$bif:erlang:bor/2 S1 S2 Dst => \
-  i_bor Fail Live S1 S2 Dst
+  i_bor Fail S1 S2 Dst
 
 gc_bif2 Fail Live u$bif:erlang:bxor/2 S1 S2 Dst => \
-  i_bxor Fail Live S1 S2 Dst
+  i_bxor Fail S1 S2 Dst
 
-gc_bif1 Fail I u$bif:erlang:bnot/1 Src Dst=d => i_int_bnot Fail Src I Dst
+gc_bif1 Fail Live u$bif:erlang:bnot/1 Src Dst=d => i_int_bnot Fail Src Dst
 
-i_increment rxy W t d
+i_increment rxy W d
 
-i_plus x xy j? t d
-i_plus s s  j? t d
+# Handle unoptimized code.
+i_plus S1=c S2=c Fail Dst => move S1 x | i_plus x S2 Fail Dst
+i_plus S1=c S2=xy Fail Dst => i_plus S2 S1 Fail Dst
 
-i_minus x x j? t d
-i_minus s s j? t d
+i_plus xy xyc j? d
 
-i_times j? t s s d
+# A minus instruction with a constant right operand will be
+# converted to an i_increment instruction, except in guards or
+# when the negated value of the constant won't fit in a guard.
+# Therefore, it very rare.
+i_minus S1 S2=c Fail Dst => move S2 x | i_minus S1 x Fail Dst
 
-i_m_div j? t s s d
-i_int_div j? t s s d
+i_minus xy xy j? d
+i_minus c xy j? d
 
-i_rem x x j? t d
-i_rem s s j? t d
+i_times j? s s d
 
-i_bsl s s j? t d
-i_bsr s s j? t d
+i_m_div j? s s d
+i_int_div j? s s d
 
-i_band x c j? t d
-i_band s s j? t d
+i_rem x x j? d
+i_rem s s j? d
 
-i_bor j? I s s d
-i_bxor j? I s s d
+i_bsl s s j? d
+i_bsr s s j? d
 
-i_int_bnot Fail Src=c Live Dst => move Src x | i_int_bnot Fail x Live Dst
+i_band x c j? d
+i_band s s j? d
 
-i_int_bnot j? S t d
+i_bor j? s s d
+i_bxor j? s s d
+
+i_int_bnot Fail Src=c Dst => move Src x | i_int_bnot Fail x Dst
+
+i_int_bnot j? S d
 
 #
 # Old guard BIFs that creates heap fragments are no longer allowed.
@@ -1533,29 +1737,28 @@ bif1 Fail u$bif:erlang:round/1 s d => too_old_compiler
 bif1 Fail u$bif:erlang:trunc/1 s d => too_old_compiler
 
 #
-# Guard BIFs.
+# Handle the length/1 guard BIF specially to make it trappable.
 #
-gc_bif1 Fail I Bif Src Dst => \
-	gen_guard_bif1(Fail, I, Bif, Src, Dst)
-
-gc_bif2 Fail I Bif S1 S2 Dst => \
-	gen_guard_bif2(Fail, I, Bif, S1, S2, Dst)
 
-gc_bif3 Fail I Bif S1 S2 S3 Dst => \
-	gen_guard_bif3(Fail, I, Bif, S1, S2, S3, Dst)
+gc_bif1 Fail=j Live u$bif:erlang:length/1 Src Dst => \
+   i_length_setup Live Src | i_length Fail Live Dst
 
-i_gc_bif1 j? W s t? d
+i_length_setup Live Src=c => move Src x | i_length_setup Live x
 
-i_gc_bif2 j? W t? s s d
+i_length_setup t xy
+i_length j? t d
 
-ii_gc_bif3/7
+#
+# Guard BIFs.
+#
+gc_bif1 p Live Bif Src Dst           => i_bif1_body Src Bif Dst
+gc_bif1 Fail=f Live Bif Src Dst      => i_bif1 Src Fail Bif Dst
 
-# A specific instruction can only have 6 operands, so we must
-# pass one of the arguments in an x register.
-ii_gc_bif3 Fail Bif Live S1 S2 S3 Dst => \
-  move S1 x | i_gc_bif3 Fail Bif Live S2 S3 Dst
+gc_bif2 p Live Bif S1 S2 Dst         => i_bif2_body S2 S1 Bif Dst
+gc_bif2 Fail=f Live Bif S1 S2 Dst    => i_bif2 S2 S1 Fail Bif Dst
 
-i_gc_bif3 j? W t? s s d
+gc_bif3 p Live Bif S1 S2 S3 Dst      => i_bif3_body S3 S2 S1 Bif Dst
+gc_bif3 Fail=f Live Bif S1 S2 S3 Dst => i_bif3 S3 S2 S1 Fail Bif Dst
 
 #
 # The following instruction is specially handled in beam_load.c
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index 869a575cb4..c261c8e117 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -63,6 +63,14 @@
 #  endif
 #endif
 
+#ifndef ERTS_NOINLINE
+#  if ERTS_AT_LEAST_GCC_VSN__(3,1,1)
+#    define ERTS_NOINLINE __attribute__((__noinline__))
+#  else
+#    define ERTS_NOINLINE
+#  endif
+#endif
+
 #if defined(DEBUG) || defined(ERTS_ENABLE_LOCK_CHECK)
 #  undef ERTS_CAN_INLINE
 #  define ERTS_CAN_INLINE 0
@@ -111,6 +119,23 @@
 #endif
 #endif
 
+/*
+ * Test for clang's convenient __has_builtin feature checking macro.
+ */
+#ifndef __has_builtin
+  #define __has_builtin(x) 0
+#endif
+
+/*
+ * Define HAVE_OVERFLOW_CHECK_BUILTINS if the overflow checking arithmetic
+ * builtins are available.
+ */
+#if ERTS_AT_LEAST_GCC_VSN__(5, 1, 0)
+#  define HAVE_OVERFLOW_CHECK_BUILTINS 1
+#elif __has_builtin(__builtin_mul_overflow)
+#  define HAVE_OVERFLOW_CHECK_BUILTINS 1
+#endif
+
 #include "erl_misc_utils.h"
 
 /*
@@ -1291,4 +1316,13 @@ erts_raw_env_next_char(byte *p, int encoding)
 
 #endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
 
+/*
+ * Magic numbers for our driver port_control callbacks.
+ * Kept them below 1<<27 to not inflict extra bignum garbage on 32-bit.
+ */
+#define ERTS_TTYSL_DRV_CONTROL_MAGIC_NUMBER  0x018b0900U
+#define ERTS_INET_DRV_CONTROL_MAGIC_NUMBER   0x03f1a300U
+#define ERTS_SPAWN_DRV_CONTROL_MAGIC_NUMBER  0x04c76a00U
+#define ERTS_FORKER_DRV_CONTROL_MAGIC_NUMBER 0x050a7800U
+
 #endif
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c
index a3069e419a..9eb020d070 100644
--- a/erts/emulator/beam/time.c
+++ b/erts/emulator/beam/time.c
@@ -316,7 +316,7 @@ struct ErtsTimerWheel_ {
 #define ERTS_TW_SLOT_AT_ONCE (-1)
 
 #define ERTS_TW_BUMP_LATER_WHEEL(TIW) \
-    ((tiw)->pos + ERTS_TW_LATER_WHEEL_SLOT_SIZE >= (TIW)->later.pos)
+    ((TIW)->pos + ERTS_TW_LATER_WHEEL_SLOT_SIZE >= (TIW)->later.pos)
 
 static int bump_later_wheel(ErtsTimerWheel *tiw, int *yield_count_p);
 
@@ -701,7 +701,8 @@ remove_timer(ErtsTimerWheel *tiw, ErtsTWheelTimer *p)
         if (slot < ERTS_TW_SOON_WHEEL_END_SLOT) {
             if (empty_slot
                 && tiw->true_next_timeout_time
-                && p->timeout_pos == tiw->next_timeout_pos) {
+                && p->timeout_pos == tiw->next_timeout_pos
+                && tiw->yield_slot == ERTS_TW_SLOT_INACTIVE) {
                 tiw->true_next_timeout_time = 0;
             }
             if (--tiw->soon.nto == 0)
@@ -714,7 +715,8 @@ remove_timer(ErtsTimerWheel *tiw, ErtsTWheelTimer *p)
                 ErtsMonotonicTime tpos = tiw->later.min_tpos;
                 tpos &= ERTS_TW_LATER_WHEEL_POS_MASK;
                 tpos -= ERTS_TW_LATER_WHEEL_SLOT_SIZE;
-                if (tpos == tiw->next_timeout_pos)
+                if (tpos == tiw->next_timeout_pos
+                    && tiw->yield_slot == ERTS_TW_SLOT_INACTIVE)
                     tiw->true_next_timeout_time = 0;
             }
             if (--tiw->later.nto == 0) {
@@ -908,7 +910,6 @@ erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time)
 
             {
                 ErtsMonotonicTime tmp_slots = bump_to - tiw->pos;
-                tmp_slots = (bump_to - tiw->pos);
                 if (tmp_slots < ERTS_TW_SOON_WHEEL_SIZE)
                     slots = (int) tmp_slots;
                 else
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index d81bd89a48..0bbae65e28 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -1069,11 +1069,11 @@ do {                               \
 
 #define HCONST 0x9e3779b9UL /* the golden ratio; an arbitrary value */
 
-Uint32
-block_hash(byte *k, unsigned length, Uint32 initval)
+static Uint32
+block_hash(byte *k, Uint length, Uint32 initval)
 {
    Uint32 a,b,c;
-   unsigned len;
+   Uint len;
 
    /* Set up the internal state */
    len = length;
@@ -1569,7 +1569,7 @@ make_hash2(Eterm term)
  * MUST BE USED AS INPUT FOR THE HASH. Two different terms must always have a
  * chance of hashing different when salted: hash([Salt|A]) vs hash([Salt|B]).
  *
- * This is why we can not use cached hash values for atoms for example.
+ * This is why we cannot use cached hash values for atoms for example.
  *
  */
 
@@ -1749,7 +1749,7 @@ make_internal_hash(Eterm term, Uint32 salt)
 	    case SUB_BINARY_SUBTAG:
 	    {
 		byte* bptr;
-		unsigned sz = binary_size(term);
+		Uint sz = binary_size(term);
 		Uint32 con = HCONST_13 + hash;
 		Uint bitoffs;
 		Uint bitsize;
@@ -1946,7 +1946,7 @@ do_allocate_logger_message(Eterm gleader, ErtsMonotonicTime *ts, Eterm *pid,
     else
         sz += MAP4_SZ /* metadata map w gl w pid*/;
 
-    *ts = ERTS_MONOTONIC_TO_USEC(erts_get_monotonic_time(NULL) + erts_get_time_offset());
+    *ts = ERTS_MONOTONIC_TO_USEC(erts_os_system_time());
     erts_bld_sint64(NULL, &sz, *ts);
 
     *bp = new_message_buffer(sz);
@@ -2701,7 +2701,8 @@ Sint erts_cmp_compound(Eterm a, Eterm b, int exact, int eq_only)
             if((AN)->sysname != (BN)->sysname)				\
                 RETURN_NEQ(erts_cmp_atoms((AN)->sysname, (BN)->sysname));	\
 	    ASSERT((AN)->creation != (BN)->creation);			\
-	    RETURN_NEQ(((AN)->creation < (BN)->creation) ? -1 : 1);	\
+            if ((AN)->creation != 0 && (BN)->creation != 0)             \
+                RETURN_NEQ(((AN)->creation < (BN)->creation) ? -1 : 1);	\
 	}								\
     } while (0)
 
@@ -3486,7 +3487,7 @@ store_external_or_ref_(Uint **hpp, ErlOffHeap* oh, Eterm ns)
     if (is_external_header(*from_hp)) {
 	ExternalThing *etp = (ExternalThing *) from_hp;
 	ASSERT(is_external(ns));
-	erts_refc_inc(&etp->node->refc, 2);
+        erts_ref_node_entry(etp->node, 2, make_boxed(to_hp));
     }
     else if (is_ordinary_ref_thing(from_hp))
 	return make_internal_ref(to_hp);
@@ -3681,30 +3682,47 @@ erts_unicode_list_to_buf_len(Eterm list)
     }
 }
 
-/*
-** Convert an integer to a byte list
-** return pointer to converted stuff (need not to be at start of buf!)
-*/
-char* Sint_to_buf(Sint n, struct Sint_buf *buf)
+/* Prints an integer in the given base, returning the number of digits printed.
+ *
+ * (*buf) is a pointer to the buffer, and is set to the start of the string
+ * when returning. */
+int Sint_to_buf(Sint n, int base, char **buf, size_t buf_size)
 {
-    char* p = &buf->s[sizeof(buf->s)-1];
-    int sign = 0;
-
-    *p-- = '\0'; /* null terminate */
-    if (n == 0)
-	*p-- = '0';
-    else if (n < 0) {
-	sign = 1;
-	n = -n;
+    char *p = &(*buf)[buf_size - 1];
+    int sign = 0, size = 0;
+
+    ASSERT(base >= 2 && base <= 36);
+
+    if (n == 0) {
+        *p-- = '0';
+        size++;
+    } else if (n < 0) {
+        sign = 1;
+        n = -n;
     }
 
     while (n != 0) {
-	*p-- = (n % 10) + '0';
-	n /= 10;
+        int digit = n % base;
+
+        if (digit < 10) {
+            *p-- = '0' + digit;
+        } else {
+            *p-- = 'A' + (digit - 10);
+        }
+
+        size++;
+
+        n /= base;
     }
-    if (sign)
-	*p-- = '-';
-    return p+1;
+
+    if (sign) {
+        *p-- = '-';
+        size++;
+    }
+
+    *buf = p + 1;
+
+    return size;
 }
 
 /* Build a list of integers in some safe memory area
@@ -4771,58 +4789,3 @@ erts_ptr_id(void *ptr)
     return ptr;
 }
 
-#ifdef DEBUG
-/*
- * Handy functions when using a debugger - don't use in the code!
- */
-
-void upp(byte *buf, size_t sz)
-{
-    bin_write(ERTS_PRINT_STDERR, NULL, buf, sz);
-}
-
-void pat(Eterm atom)
-{
-    upp(atom_tab(atom_val(atom))->name,
-	atom_tab(atom_val(atom))->len);
-}
-
-
-void pinfo()
-{
-    process_info(ERTS_PRINT_STDOUT, NULL);
-}
-
-
-void pp(p)
-Process *p;
-{
-    if(p)
-	print_process_info(ERTS_PRINT_STDERR, NULL, p);
-}
-
-void ppi(Eterm pid)
-{
-    pp(erts_proc_lookup(pid));
-}
-
-void td(Eterm x)
-{
-    erts_fprintf(stderr, "%T\n", x);
-}
-
-void
-ps(Process* p, Eterm* stop)
-{
-    Eterm* sp = STACK_START(p) - 1;
-
-    if (stop <= STACK_END(p)) {
-        stop = STACK_END(p) + 1;
-    }
-
-    while(sp >= stop) {
-	erts_printf("%p: %.75T\n", sp, *sp);
-	sp--;
-    }
-}
-#endif
diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index 47eb5df7dd..66ff8d8450 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  *
- * Copyright Ericsson AB 1997-2018. All Rights Reserved.
+ * Copyright Ericsson AB 1997-2019. All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -574,7 +574,7 @@ static int my_strncasecmp(const char *s1, const char *s2, size_t n)
                                     driver_select(port, e, mode | (on?ERL_DRV_USE:0), on)
 
 #define sock_select(d, flags, onoff) do { \
-        ASSERT(!(d)->is_ignored); \
+        ASSERT(!INET_IGNORED(d));         \
         (d)->event_mask = (onoff) ? \
                  ((d)->event_mask | (flags)) : \
                  ((d)->event_mask & ~(flags)); \
@@ -634,9 +634,13 @@ static size_t my_strnlen(const char *s, size_t maxlen)
  * header length.  To get the header length we use
  * the pointer difference from the cmsg start pointer
  * to the CMSG_DATA(cmsg) pointer.
+ *
+ * Some platforms (seen on ppc Linux 2.6.29-3.ydl61.3)
+ * may return 0 as the cmsg_len if the cmsg is to be ignored.
  */
 #define LEN_CMSG_DATA(cmsg)                                             \
-    ((cmsg)->cmsg_len - ((char*)CMSG_DATA(cmsg) - (char*)(cmsg)))
+    ((cmsg)->cmsg_len < sizeof (struct cmsghdr) ? 0 :                   \
+     (cmsg)->cmsg_len - ((char*)CMSG_DATA(cmsg) - (char*)(cmsg)))
 #define NXT_CMSG_HDR(cmsg)                                              \
     ((struct cmsghdr*)(((char*)(cmsg)) + CMSG_SPACE(LEN_CMSG_DATA(cmsg))))
 #endif
@@ -894,6 +898,15 @@ static size_t my_strnlen(const char *s, size_t maxlen)
 #define INET_CMSG_RECVTCLASS     (1 << 1) /* am_recvtclass, am_tclass */
 #define INET_CMSG_RECVTTL        (1 << 2) /* am_recvttl, am_ttl */
 
+/* Inet flags */
+#define INET_FLG_BUFFER_SET      (1 << 0) /* am_buffer has been set by user */
+#define INET_FLG_IS_IGNORED      (1 << 1) /* If a fd is ignored by the inet_drv.
+                                             This flag should be set to true when
+                                             the fd is used outside of inet_drv. */
+#define INET_FLG_IS_IGNORED_RD   (1 << 2)
+#define INET_FLG_IS_IGNORED_WR   (1 << 3)
+#define INET_FLG_IS_IGNORED_PASS (1 << 4)
+
 /*
 ** End of interface constants.
 **--------------------------------------------------------------------------*/
@@ -939,10 +952,11 @@ static size_t my_strnlen(const char *s, size_t maxlen)
 #define INET_IFNAMSIZ          16
 
 /* INET Ignore states */
-#define INET_IGNORE_NONE    0
-#define INET_IGNORE_READ    (1 << 0)
-#define INET_IGNORE_WRITE   (1 << 1)
-#define INET_IGNORE_PASSIVE (1 << 2)
+#define INET_IGNORE_CLEAR(desc) ((desc)->flags & ~(INET_IGNORE_READ|INET_IGNORE_WRITE|INET_IGNORE_PASSIVE))
+#define INET_IGNORED(desc)   ((desc)->flags & INET_FLG_IS_IGNORED)
+#define INET_IGNORE_READ    (INET_FLG_IS_IGNORED|INET_FLG_IS_IGNORED_RD)
+#define INET_IGNORE_WRITE   (INET_FLG_IS_IGNORED|INET_FLG_IS_IGNORED_WR)
+#define INET_IGNORE_PASSIVE (INET_FLG_IS_IGNORED|INET_FLG_IS_IGNORED_PASS)
 
 /* Max length of Erlang Term Buffer (for outputting structured terms):  */
 #ifdef  HAVE_SCTP
@@ -1063,6 +1077,7 @@ typedef struct {
     long forced_events;           /* Mask of events that are forcefully signalled 
 				   on windows see winsock_event_select 
 				   for details */
+    int err;                      /* Keeps error code for closed socket */
     int send_would_block;       /* Last send attempt failed with "WOULDBLOCK" */
 #endif
     ErlDrvPort  port;           /* the port identifier */
@@ -1124,9 +1139,7 @@ typedef struct {
     double send_avg;            /* average packet size sent */
 
     subs_list empty_out_q_subs; /* Empty out queue subscribers */
-    int is_ignored;             /* if a fd is ignored by the inet_drv.
-				   This flag should be set to true when
-				   the fd is used outside of inet_drv. */
+    int flags;
 #ifdef HAVE_SETNS
     char *netns;                /* Socket network namespace name
 				   as full file path */
@@ -3367,6 +3380,71 @@ static int udp_parse_ancillary_data(ErlDrvTermData *spec, int i,
     i = LOAD_NIL(spec, i);
     return LOAD_LIST(spec, i, n+1);
 }
+
+static int compile_ancillary_data(struct msghdr *mhdr,
+                                  char *ptr, ErlDrvSizeT anc_len) {
+    struct cmsghdr *cmsg;
+    size_t controllen = 0;
+    cmsg = CMSG_FIRSTHDR(mhdr);
+    for (;;) {
+        if (anc_len == 0) {
+            /* End of options to compile */
+            mhdr->msg_controllen = controllen;
+            return 0;
+        }
+        if (cmsg == NULL) {
+            /* End of destination before end of options */
+            return 1;
+        }
+
+#define COMPILE_ANCILLARY_DATA_ITEM(Level, Opt, Type, Get, Size)        \
+        do {                                                            \
+            if (anc_len < (Size)) return 1;                             \
+            sys_memset(cmsg, '\0', CMSG_SPACE(sizeof(Type)));           \
+            cmsg->cmsg_level = Level;                                   \
+            cmsg->cmsg_type = Opt;                                      \
+            cmsg->cmsg_len = CMSG_LEN(sizeof(Type));                    \
+            *((Type *) CMSG_DATA(cmsg)) = Get(ptr);                     \
+            controllen += CMSG_SPACE(sizeof(Type));                     \
+            cmsg = CMSG_NXTHDR(mhdr, cmsg);                             \
+            ptr += 4;                                                   \
+            anc_len -= 4;                                               \
+        } while (0)
+#define SIZEOF_ANCILLARY_DATA (2 * CMSG_SPACE(sizeof(int)))
+        /* (IP_TOS | IPV6_TCLASS) + IP_TTL */
+
+        switch (anc_len--, *ptr++) {
+        case INET_OPT_TOS: {
+#if defined(IPPROTO_IP) && defined(IP_TOS)
+            COMPILE_ANCILLARY_DATA_ITEM(IPPROTO_IP, IP_TOS, int, get_int32, 4);
+#else
+            return 1; /* Socket option not implemented */
+#endif
+            break;
+        }
+        case INET_OPT_TTL: {
+#if defined(IPPROTO_IP) && defined(IP_TTL)
+            COMPILE_ANCILLARY_DATA_ITEM(IPPROTO_IP, IP_TTL, int, get_int32, 4);
+#else
+            return 1; /* Socket option not implemented */
+#endif
+            break;
+        }
+        case INET_OPT_TCLASS: {
+#if defined(IPPROTO_IPV6) && defined(IPV6_TCLASS)
+            COMPILE_ANCILLARY_DATA_ITEM(IPPROTO_IPV6, IPV6_TCLASS, int, get_int32, 4);
+#else
+            return 1; /* Socket option not implemented */
+#endif
+            break;
+        }
+        default:
+            /* Unknow socket option */
+            return 1;
+        }
+#undef COMPILE_ANCILLARY_DATA_ITEM
+    }
+}
 #endif /* ifndef __WIN32__ */
 
 /* 
@@ -4547,7 +4625,7 @@ static void desc_close(inet_descriptor* desc)
 	 * We should close the fd here, but the other driver might still
 	 * be selecting on it.
 	 */
-	if (!desc->is_ignored)
+	if (!INET_IGNORED(desc))
 	    driver_select(desc->port,(ErlDrvEvent)(long)desc->event, 
 			  ERL_DRV_USE, 0);
 	else
@@ -4568,7 +4646,7 @@ static void desc_close_read(inet_descriptor* desc)
 {
     if (desc->s != INVALID_SOCKET) {
 #ifdef __WIN32__
-	/* This call can not be right???
+	/* This call cannot be right???
 	 * We want to turn off read events but keep any write events.
 	 * But on windows driver_select(...,READ,1) is only used as a
 	 * way to hook into the pollset. sock_select is used to control
@@ -6308,6 +6386,7 @@ static int inet_set_opts(inet_descriptor* desc, char* ptr, int len)
 		    (long)desc->port, desc->s, ival));
 	    if (ival < INET_MIN_BUFFER) ival = INET_MIN_BUFFER;
 	    desc->bufsz = ival;
+            desc->flags |= INET_FLG_BUFFER_SET;
 	    continue;
 
 	case INET_LOPT_ACTIVE:
@@ -6503,6 +6582,16 @@ static int inet_set_opts(inet_descriptor* desc, char* ptr, int len)
 	case INET_OPT_RCVBUF:    type = SO_RCVBUF; 
 	    DEBUGF(("inet_set_opts(%ld): s=%d, SO_RCVBUF=%d\r\n",
 		    (long)desc->port, desc->s, ival));
+            if (!(desc->flags & INET_FLG_BUFFER_SET)) {
+                /* make sure we have desc->bufsz >= SO_RCVBUF */
+                if (ival > (1 << 16) && desc->stype == SOCK_DGRAM && !IS_SCTP(desc))
+                    /* For UDP we don't want to automatically
+                       set the buffer size to be larger than
+                       the theoretical max MTU */
+                    desc->bufsz = 1 << 16;
+                else if (ival > desc->bufsz)
+                    desc->bufsz = ival;
+            }
 	    break;
 	case INET_OPT_LINGER:    type = SO_LINGER; 
 	    if (len < 4)
@@ -6748,23 +6837,17 @@ static int inet_set_opts(inet_descriptor* desc, char* ptr, int len)
 	}
 	DEBUGF(("inet_set_opts(%ld): s=%d returned %d\r\n",
 		(long)desc->port, desc->s, res));
-	if (type == SO_RCVBUF) {
-	    /* make sure we have desc->bufsz >= SO_RCVBUF */
-            if (ival > (1 << 16) && desc->stype == SOCK_DGRAM && !IS_SCTP(desc))
-                /* For UDP we don't want to automatically
-                   set the buffer size to be larger than
-                   the theoretical max MTU */
-                desc->bufsz = 1 << 16;
-	    else if (ival > desc->bufsz)
-		desc->bufsz = ival;
-	}
     }
 
     if ( ((desc->stype == SOCK_STREAM) && IS_CONNECTED(desc)) ||
 	((desc->stype == SOCK_DGRAM) && IS_OPEN(desc))) {
 
-	if (desc->active != old_active)
+	if (desc->active != old_active) {
+            /* Need to cancel the read_packet timer if we go from active to passive. */
+            if (desc->active == INET_PASSIVE && desc->stype == SOCK_DGRAM)
+                driver_cancel_timer(desc->port);
 	    sock_select(desc, (FD_READ|FD_CLOSE), (desc->active>0));
+        }
 
 	/* XXX: UDP sockets could also trigger immediate read here NIY */
 	if ((desc->stype==SOCK_STREAM) && desc->active) {
@@ -6906,6 +6989,7 @@ static int sctp_set_opts(inet_descriptor* desc, char* ptr, int len)
 
 	    if (desc->bufsz < INET_MIN_BUFFER)
 		desc->bufsz = INET_MIN_BUFFER;
+            desc->flags |= INET_FLG_BUFFER_SET;
 	    res = 0;	  /* This does not affect the kernel buffer size */
 	    continue;
 
@@ -7027,6 +7111,7 @@ static int sctp_set_opts(inet_descriptor* desc, char* ptr, int len)
 	       smaller than the kernel one: */
 	    if (desc->bufsz <= arg.ival)
 		desc->bufsz  = arg.ival;
+            desc->flags |= INET_FLG_BUFFER_SET;
 	    break;
 	}
 	case INET_OPT_SNDBUF:
@@ -7037,10 +7122,6 @@ static int sctp_set_opts(inet_descriptor* desc, char* ptr, int len)
 	    arg_ptr = (char*) (&arg.ival);
 	    arg_sz  = sizeof  ( arg.ival);
 
-	    /* Adjust the size of the user-level recv buffer, so it's not
-	       smaller than the kernel one: */
-	    if (desc->bufsz <= arg.ival)
-		desc->bufsz  = arg.ival;
 	    break;
 	}
 	case INET_OPT_REUSEADDR:
@@ -9048,6 +9129,7 @@ static ErlDrvData inet_start(ErlDrvPort port, int size, int protocol)
     desc->event_mask = 0;
 #ifdef __WIN32__
     desc->forced_events = 0;
+    desc->err = 0;
     desc->send_would_block = 0;
 #endif
     desc->port = port;
@@ -9097,7 +9179,7 @@ static ErlDrvData inet_start(ErlDrvPort port, int size, int protocol)
 
     sys_memzero((char *)&desc->remote,sizeof(desc->remote));
 
-    desc->is_ignored = 0;
+    desc->flags = 0;
 
 #ifdef HAVE_SETNS
     desc->netns = NULL;
@@ -9499,19 +9581,19 @@ static ErlDrvSSizeT inet_ctl(inet_descriptor* desc, int cmd, char* buf,
       if (desc->stype != SOCK_STREAM)
 	  return ctl_error(EINVAL, rbuf, rsize);
 
-      if (*buf == 1 && !desc->is_ignored) {
+      if (*buf == 1 && !INET_IGNORED(desc)) {
 	  sock_select(desc, (FD_READ|FD_WRITE|FD_CLOSE|ERL_DRV_USE_NO_CALLBACK), 0);
 	  if (desc->active)
-	    desc->is_ignored = INET_IGNORE_READ;
+	    desc->flags |= INET_IGNORE_READ;
 	  else
-	    desc->is_ignored = INET_IGNORE_PASSIVE;
-      } else if (*buf == 0 && desc->is_ignored) {
+	    desc->flags |= INET_IGNORE_PASSIVE;
+      } else if (*buf == 0 && INET_IGNORED(desc)) {
 	  int flags = FD_CLOSE;
-	  if (desc->is_ignored & INET_IGNORE_READ)
+	  if (desc->flags & INET_IGNORE_READ)
 	    flags |= FD_READ;
-	  if (desc->is_ignored & INET_IGNORE_WRITE)
+	  if (desc->flags & INET_IGNORE_WRITE)
 	    flags |= FD_WRITE;
-	  desc->is_ignored = INET_IGNORE_NONE;
+	  desc->flags = INET_IGNORE_CLEAR(desc);
 	  if (flags != FD_CLOSE)
 	    sock_select(desc, flags, 1);
       } else
@@ -9831,10 +9913,8 @@ static tcp_descriptor* tcp_inet_copy(tcp_descriptor* desc,SOCKET s,
     copy_desc->send_timeout  = desc->send_timeout;
     copy_desc->send_timeout_close = desc->send_timeout_close;
 
-    if (desc->tcp_add_flags & TCP_ADDF_SHOW_ECONNRESET)
-	copy_desc->tcp_add_flags |= TCP_ADDF_SHOW_ECONNRESET;
-    else
-	copy_desc->tcp_add_flags &= ~TCP_ADDF_SHOW_ECONNRESET;
+    copy_desc->tcp_add_flags = desc->tcp_add_flags
+        & (TCP_ADDF_SHOW_ECONNRESET | TCP_ADDF_LINGER_ZERO);
     
     /* The new port will be linked and connected to the original caller */
     port = driver_create_port(port, owner, "tcp_inet", (ErlDrvData) copy_desc);
@@ -9951,6 +10031,7 @@ static ErlDrvSSizeT tcp_inet_ctl(ErlDrvData e, unsigned int cmd,
 {
     tcp_descriptor* desc = (tcp_descriptor*)e;
 
+    cmd -= ERTS_INET_DRV_CONTROL_MAGIC_NUMBER;
     switch(cmd) {
     case INET_REQ_OPEN: { /* open socket and return internal index */
 	int domain;
@@ -10226,17 +10307,17 @@ static ErlDrvSSizeT tcp_inet_ctl(ErlDrvData e, unsigned int cmd,
 	if (enq_async(INETP(desc), tbuf, TCP_REQ_RECV) < 0)
 	    return ctl_error(EALREADY, rbuf, rsize);
 
-	if (INETP(desc)->is_ignored || tcp_recv(desc, n) == 0) {
+	if (INET_IGNORED(INETP(desc)) || tcp_recv(desc, n) == 0) {
 	    if (timeout == 0)
 		async_error_am(INETP(desc), am_timeout);
 	    else {
 		if (timeout != INET_INFINITY)
                     add_multi_timer(desc, INETP(desc)->port, 0,
                                     timeout, &tcp_inet_recv_timeout);
-		if (!INETP(desc)->is_ignored)
+		if (!INET_IGNORED(INETP(desc)))
 		    sock_select(INETP(desc),(FD_READ|FD_CLOSE),1);
 		else
-		  INETP(desc)->is_ignored |= INET_IGNORE_READ;
+		  INETP(desc)->flags |= INET_IGNORE_READ;
 	    }
 	}
 	return ctl_reply(INET_REP_OK, tbuf, 2, rbuf, rsize);
@@ -10898,7 +10979,7 @@ static int winsock_event_select(inet_descriptor *desc, int flags, int on)
 {
     int save_event_mask = desc->event_mask;
     
-    desc->forced_events = 0;
+    desc->forced_events &= FD_CLOSE;
     if (on) 
 	desc->event_mask |= flags;
     else
@@ -10950,7 +11031,7 @@ static int winsock_event_select(inet_descriptor *desc, int flags, int on)
 		TIMEVAL tmo = {0,0};
 		FD_SET fds;
 		int ret;
-		
+
 		FD_ZERO(&fds);
 		FD_SET(desc->s,&fds);
 		do_force = (select(desc->s+1,0,&fds,0,&tmo) > 0);
@@ -10967,7 +11048,7 @@ static int winsock_event_select(inet_descriptor *desc, int flags, int on)
 	    FD_SET fds;
 	    int ret;
 	    unsigned long arg;
-	  
+
 	    FD_ZERO(&fds);
 	    FD_SET(desc->s,&fds);
 	    ret = select(desc->s+1,&fds,0,0,&tmo);
@@ -11006,13 +11087,16 @@ static void tcp_inet_event(ErlDrvData e, ErlDrvEvent event)
 	goto error;
     }
 
-    DEBUGF((" => event=%02X, mask=%02X\r\n",
-	    netEv.lNetworkEvents, desc->inet.event_mask));
+    DEBUGF((" => event=%02X, mask=%02X, forced=%02X\r\n",
+	    netEv.lNetworkEvents, desc->inet.event_mask,
+            desc->inet.forced_events));
 
     /* Add the forced events. */
-
     netEv.lNetworkEvents |= desc->inet.forced_events;
 
+    if (desc->inet.forced_events & FD_CLOSE)
+        netEv.iErrorCode[FD_CLOSE_BIT] = desc->inet.err;
+
     /*
      * Calling WSAEventSelect() with a mask of 0 doesn't always turn off
      * all events.  To avoid acting on events we don't want, we mask
@@ -11032,16 +11116,29 @@ static void tcp_inet_event(ErlDrvData e, ErlDrvEvent event)
 	    goto error;
 	}
 	if (netEv.lNetworkEvents & FD_CLOSE) {
-	    /*
+
+            /* We may not get any more FD_CLOSE events so we
+               keep this event and always signal it from
+               this moment on. */
+            if ((desc->inet.forced_events & FD_CLOSE) == 0) {
+                desc->inet.forced_events |= FD_CLOSE;
+                desc->inet.err = netEv.iErrorCode[FD_CLOSE_BIT];
+            }
+
+            /*
 	     * We must loop to read out the remaining packets (if any).
 	     */
 	    for (;;) {
-		DEBUGF(("Retrying read due to closed port\r\n"));
-		/* XXX The buffer will be thrown away on error (empty que).
-		   Possible SMP FIXME. */
-		if (!desc->inet.active && (desc->inet.opt) == NULL) {
-		    goto error;
-		}
+
+                /* if passive and no subscribers, break loop */
+                if (!desc->inet.active && desc->inet.opt == NULL) {
+                    /* do not trigger close event when socket is
+                       transitioned to passive */
+                    netEv.lNetworkEvents &= ~FD_CLOSE;
+                    break;
+                }
+
+		DEBUGF(("Retrying read due to FD_CLOSE\r\n"));
 		if (tcp_inet_input(desc, event) < 0) {
 		    goto error;
 		}
@@ -11103,7 +11200,7 @@ static int tcp_inet_input(tcp_descriptor* desc, HANDLE event)
 #ifdef DEBUG
     long port = (long) desc->inet.port;  /* Used after driver_exit() */
 #endif
-    ASSERT(!INETP(desc)->is_ignored);
+    ASSERT(!INET_IGNORED(INETP(desc)));
     DEBUGF(("tcp_inet_input(%ld) {s=%d\r\n", port, desc->inet.s));
     /* XXX fprintf(stderr,"tcp_inet_input(%ld) {s=%d}\r\n",(long) desc->inet.port, desc->inet.s); */
     if (desc->inet.state == INET_STATE_ACCEPTING) {
@@ -11370,7 +11467,7 @@ static int tcp_shutdown_error(tcp_descriptor* desc, int err)
 static void tcp_inet_delay_send(ErlDrvData data, ErlDrvTermData dummy)
 {
     tcp_descriptor *desc = (tcp_descriptor*)data;
-    (void)tcp_inet_output(desc, INETP(desc)->s);
+    (void)tcp_inet_output(desc, (HANDLE) INETP(desc)->s);
 }
 
 /*
@@ -11438,8 +11535,8 @@ static int tcp_sendv(tcp_descriptor* desc, ErlIOVec* ev)
 	DEBUGF(("tcp_sendv(%ld): s=%d, about to send "LLU","LLU" bytes\r\n",
 		(long)desc->inet.port, desc->inet.s, (llu_t)h_len, (llu_t)len));
 
-	if (INETP(desc)->is_ignored) {
-	    INETP(desc)->is_ignored |= INET_IGNORE_WRITE;
+	if (INET_IGNORED(INETP(desc))) {
+	    INETP(desc)->flags |= INET_IGNORE_WRITE;
 	    n = 0;
 	} else if (desc->tcp_add_flags & TCP_ADDF_DELAY_SEND) {
             driver_enqv(ix, ev, 0);
@@ -11474,7 +11571,7 @@ static int tcp_sendv(tcp_descriptor* desc, ErlIOVec* ev)
 	DEBUGF(("tcp_sendv(%ld): s=%d, Send failed, queuing\r\n", 
 		(long)desc->inet.port, desc->inet.s));
 	driver_enqv(ix, ev, n); 
-	if (!INETP(desc)->is_ignored)
+	if (!INET_IGNORED(INETP(desc)))
 	    sock_select(INETP(desc),(FD_WRITE|FD_CLOSE), 1);
     }
     return 0;
@@ -11543,8 +11640,8 @@ static int tcp_send(tcp_descriptor* desc, char* ptr, ErlDrvSizeT len)
 
 	DEBUGF(("tcp_send(%ld): s=%d, about to send "LLU","LLU" bytes\r\n",
 		(long)desc->inet.port, desc->inet.s, (llu_t)h_len, (llu_t)len));
-	if (INETP(desc)->is_ignored) {
-	    INETP(desc)->is_ignored |= INET_IGNORE_WRITE;
+	if (INET_IGNORED(INETP(desc))) {
+	    INETP(desc)->flags |= INET_IGNORE_WRITE;
 	    n = 0;
 	} else if (desc->tcp_add_flags & TCP_ADDF_DELAY_SEND) {
 	    sock_send(desc->inet.s, buf, 0, 0);
@@ -11577,7 +11674,7 @@ static int tcp_send(tcp_descriptor* desc, char* ptr, ErlDrvSizeT len)
 	    n -= h_len;
 	    driver_enq(ix, ptr+n, len-n);
 	}
-	if (!INETP(desc)->is_ignored)
+	if (!INET_IGNORED(INETP(desc)))
 	    sock_select(INETP(desc),(FD_WRITE|FD_CLOSE), 1);
     }
     return 0;
@@ -11858,7 +11955,7 @@ static int tcp_inet_output(tcp_descriptor* desc, HANDLE event)
     int ret = 0;
     ErlDrvPort ix = desc->inet.port;
 
-    ASSERT(!INETP(desc)->is_ignored);
+    ASSERT(!INET_IGNORED(INETP(desc)));
     DEBUGF(("tcp_inet_output(%ld) {s=%d\r\n", 
 	    (long)desc->inet.port, desc->inet.s));
     if (desc->inet.state == INET_STATE_CONNECTING) {
@@ -12180,6 +12277,7 @@ static ErlDrvSSizeT packet_inet_ctl(ErlDrvData e, unsigned int cmd, char* buf,
     int type = SOCK_DGRAM;
     int af = AF_INET;
 
+    cmd -= ERTS_INET_DRV_CONTROL_MAGIC_NUMBER;
     switch(cmd) {
     case INET_REQ_OPEN:   /* open socket and return internal index */
 	DEBUGF(("packet_inet_ctl(%ld): OPEN\r\n", (long)desc->port)); 
@@ -12532,9 +12630,12 @@ static void packet_inet_timeout(ErlDrvData e)
 {
     udp_descriptor  * udesc = (udp_descriptor*) e;
     inet_descriptor * desc  = INETP(udesc);
-    if (!(desc->active))
+    if (!(desc->active)) {
 	sock_select(desc, FD_READ, 0);
-    async_error_am (desc, am_timeout);
+        async_error_am (desc, am_timeout);
+    } else {
+        (void)packet_inet_input(udesc, (HANDLE) desc->s);
+    }
 }
 
 
@@ -12577,11 +12678,8 @@ static void packet_inet_command(ErlDrvData e, char* buf, ErlDrvSizeT len)
 	    char ancd[CMSG_SPACE(sizeof(*sri))];
 	} cmsg;
 	
-	if (len < SCTP_GET_SENDPARAMS_LEN) {
-	    inet_reply_error(desc, EINVAL);
-	    return;
-	}
-	
+	if (len < SCTP_GET_SENDPARAMS_LEN) goto return_einval;
+
 	/* The ancillary data */
 	sri = (struct sctp_sndrcvinfo *) (CMSG_DATA(&cmsg.hdr));
 	/* Get the "sndrcvinfo" from the buffer, advancing the "ptr": */
@@ -12614,28 +12712,82 @@ static void packet_inet_command(ErlDrvData e, char* buf, ErlDrvSizeT len)
 	goto check_result_code;
     }
 #endif
-    /* UDP socket. Even if it is connected, there is an address prefix
-       here -- ignored for connected sockets: */
-    sz = len;
-    qtr = ptr;
-    xerror = inet_set_faddress(desc->sfamily, &other, &qtr, &sz);
-    if (xerror != NULL) {
-        inet_reply_error_am(desc, driver_mk_atom(xerror));
-	return;
-    }
-    len -= (qtr - ptr);
-    ptr = qtr;
-    /* Now "ptr" is the user data ptr, "len" is data length: */
-    inet_output_count(desc, len);
-    
-    if (desc->state & INET_F_ACTIVE) { /* connected (ignore address) */
-	code = sock_send(desc->s, ptr, len, 0);
-    }
-    else {
-	code = sock_sendto(desc->s, ptr, len, 0, &other.sa, sz);
+    {
+        ErlDrvSizeT anc_len;
+        
+        /* UDP socket. Even if it is connected, there is an address prefix
+           here -- ignored for connected sockets: */
+        sz = len;
+        qtr = ptr;
+        xerror = inet_set_faddress(desc->sfamily, &other, &qtr, &sz);
+        if (xerror != NULL) {
+            inet_reply_error_am(desc, driver_mk_atom(xerror));
+            return;
+        }
+        len -= (qtr - ptr);
+        ptr = qtr;
+
+        /* Here comes ancillary data */
+        if (len < 4) goto return_einval;
+        anc_len = get_int32(ptr);
+        len -= 4; ptr += 4;
+        if (len < anc_len) goto return_einval;
+
+        if (anc_len == 0) {
+            /* Empty ancillary data */
+            /* Now "ptr" is the user data ptr, "len" is data length: */
+            inet_output_count(desc, len);
+            if (desc->state & INET_F_ACTIVE) {
+                /* connected (ignore address) */
+                code = sock_send(desc->s, ptr, len, 0);
+            }
+            else {
+                code = sock_sendto(desc->s, ptr, len, 0, &other.sa, sz);
+            }
+        }
+        else {
+#ifdef __WIN32__
+            goto return_einval; /* Can not send ancillary data on Windows */
+#else
+            struct iovec iov[1];
+            struct msghdr mhdr;
+            union { /* For ancillary data         */
+                struct cmsghdr hdr;
+                char ancd[SIZEOF_ANCILLARY_DATA];
+            } cmsg;
+            sys_memset(&iov, '\0', sizeof(iov));
+            sys_memset(&mhdr, '\0', sizeof(mhdr));
+            sys_memset(&cmsg, '\0', sizeof(cmsg));
+            if (desc->state & INET_F_ACTIVE) {
+                /* connected (ignore address) */
+                mhdr.msg_name = NULL;
+                mhdr.msg_namelen = 0;
+            }
+            else {
+                mhdr.msg_name = &other;
+                mhdr.msg_namelen = sz;
+            }
+            mhdr.msg_control = cmsg.ancd;
+            mhdr.msg_controllen = sizeof(cmsg.ancd);
+            if (compile_ancillary_data(&mhdr, ptr, anc_len) != 0) {
+                goto return_einval;
+            }
+            ASSERT(mhdr.msg_controllen != 0);
+            len -= anc_len;
+            ptr += anc_len;
+            /* Now "ptr" is the user data ptr, "len" is data length: */
+            iov[0].iov_len = len;
+            iov[0].iov_base = ptr;
+            mhdr.msg_iov = iov;
+            mhdr.msg_iovlen = 1;
+            mhdr.msg_flags = 0;
+            inet_output_count(desc, len);
+            code = sock_sendmsg(desc->s, &mhdr, 0);
+#endif
+        }
     }
 
-#ifdef HAVE_SCTP    
+#ifdef HAVE_SCTP
  check_result_code:
     /* "code" analysis is the same for both SCTP and UDP cases above: */
 #endif
@@ -12645,8 +12797,15 @@ static void packet_inet_command(ErlDrvData e, char* buf, ErlDrvSizeT len)
     }
     else
 	inet_reply_ok(desc);
+    return;
+    
+ return_einval:
+    inet_reply_error(desc, EINVAL);
+    return;
 }
-#endif
+
+#endif /* HAVE_UDP */
+
 
 #ifdef __WIN32__
 static void packet_inet_event(ErlDrvData e, ErlDrvEvent event)
@@ -12890,6 +13049,15 @@ static int packet_inet_input(udp_descriptor* udesc, HANDLE event)
 	sock_select(desc, FD_READ, 1);
     }
 #endif
+
+    /* We set a timer on the port to trigger now.
+       This emulates a "yield" operation as that is
+       what we want to do here. We do *NOT* do a deselect
+       as that is expensive, instead we check if the
+       socket it still active when the timeout triggers
+       and if it is not, then we just ignore the timeout */
+    driver_set_timer(desc->port, 0);
+
     return count;
 }
 
@@ -12956,38 +13124,40 @@ make_noninheritable_handle(SOCKET s)
 static void fire_multi_timers(tcp_descriptor *desc, ErlDrvPort port,
 			      ErlDrvData data)
 {
-    ErlDrvTime next_timeout;
-    MultiTimerData *curr = desc->mtd;
-    if (!curr) {
-	ASSERT(0);
-	return;
+    ErlDrvTime next_timeout = 0;
+    if (!desc->mtd) {
+        ASSERT(0);
+        return;
     }
 #ifdef DEBUG
     {
 	ErlDrvTime chk = erl_drv_monotonic_time(ERL_DRV_MSEC);
-	ASSERT(chk >= curr->when);
+	ASSERT(chk >= desc->mtd->when);
     }
 #endif
     do {
-	MultiTimerData *save = curr;
+	MultiTimerData save = *desc->mtd;
 
-	(*(save->timeout_function))(data,save->caller);
+        /* We first remove the timer so that the timeout_functions has
+           can call clean_multi_timers without breaking anything */
+        if (desc->mtd_cache == NULL) {
+            desc->mtd_cache = desc->mtd;
+        } else {
+            FREE(desc->mtd);
+        }
 
-        curr = curr->next;
+        desc->mtd = save.next;
+        if (desc->mtd != NULL)
+            desc->mtd->prev = NULL;
 
-        if (desc->mtd_cache == NULL)
-            desc->mtd_cache = save;
-        else
-            FREE(save);
+	(*(save.timeout_function))(data,save.caller);
 
-	if (curr == NULL) {
-            desc->mtd = NULL;
+        if (desc->mtd == NULL)
 	    return;
-	}
-	curr->prev = NULL;
-	next_timeout = curr->when - erl_drv_monotonic_time(ERL_DRV_MSEC);
+
+	next_timeout = desc->mtd->when - erl_drv_monotonic_time(ERL_DRV_MSEC);
     } while (next_timeout <= 0);
-    desc->mtd = curr;
+
     driver_set_timer(port, (unsigned long) next_timeout);
 }
 
diff --git a/erts/emulator/drivers/unix/ttsl_drv.c b/erts/emulator/drivers/unix/ttsl_drv.c
index 28c6cc0f94..f6864f96da 100644
--- a/erts/emulator/drivers/unix/ttsl_drv.c
+++ b/erts/emulator/drivers/unix/ttsl_drv.c
@@ -31,7 +31,7 @@
 static int ttysl_init(void);
 static ErlDrvData ttysl_start(ErlDrvPort, char*);
 
-#ifdef HAVE_TERMCAP  /* else make an empty driver that can not be opened */
+#ifdef HAVE_TERMCAP  /* else make an empty driver that cannot be opened */
 
 #ifndef WANT_NONBLOCKING
 #define WANT_NONBLOCKING
@@ -394,6 +394,8 @@ static ErlDrvSSizeT ttysl_control(ErlDrvData drv_data,
 {
     char resbuff[2*sizeof(Uint32)];
     ErlDrvSizeT res_size;
+
+    command -= ERTS_TTYSL_DRV_CONTROL_MAGIC_NUMBER;
     switch (command) {
     case CTRL_OP_GET_WINSIZE:
 	{
@@ -419,7 +421,7 @@ static ErlDrvSSizeT ttysl_control(ErlDrvData drv_data,
 	}
 	break;
     default:
-	return 0;
+	return -1;
     }
     if (rlen < res_size) {
 	*rbuf = driver_alloc(res_size);
diff --git a/erts/emulator/drivers/win32/ttsl_drv.c b/erts/emulator/drivers/win32/ttsl_drv.c
index 99e7fb25a4..d19bfa3079 100644
--- a/erts/emulator/drivers/win32/ttsl_drv.c
+++ b/erts/emulator/drivers/win32/ttsl_drv.c
@@ -176,6 +176,8 @@ static ErlDrvSSizeT ttysl_control(ErlDrvData drv_data,
 {
     char resbuff[2*sizeof(Uint32)];
     ErlDrvSizeT res_size;
+
+    command -= ERTS_TTYSL_DRV_CONTROL_MAGIC_NUMBER;
     switch (command) {
     case CTRL_OP_GET_WINSIZE:
 	{
@@ -201,7 +203,7 @@ static ErlDrvSSizeT ttysl_control(ErlDrvData drv_data,
 	}
 	break;
     default:
-	return 0;
+	return -1;
     }
     if (rlen < res_size) {
 	*rbuf = driver_alloc(res_size);
diff --git a/erts/emulator/hipe/hipe_arm.c b/erts/emulator/hipe/hipe_arm.c
index b61939724c..3e1d7e4d5e 100644
--- a/erts/emulator/hipe/hipe_arm.c
+++ b/erts/emulator/hipe/hipe_arm.c
@@ -18,6 +18,7 @@
  * %CopyrightEnd%
  */
 
+#ifdef __arm__
 
 #include <stddef.h>	/* offsetof() */
 #ifdef HAVE_CONFIG_H
@@ -30,24 +31,39 @@
 #include "hipe_native_bif.h"	/* nbif_callemu() */
 #include "hipe_bif0.h"
 
+#ifndef __has_builtin
+# define __has_builtin(x) 0
+#endif
+
 /* Flush dcache and invalidate icache for a range of addresses. */
 void hipe_flush_icache_range(void *address, unsigned int nbytes)
 {
-#if defined(__ARM_EABI__)
+    void* end = (char*)address + nbytes;
+
+#if ERTS_AT_LEAST_GCC_VSN__(4, 3, 0) || __has_builtin(__builtin___clear_cache)
+    __builtin___clear_cache(address, end);
+#elif defined(__clang__)
+    void __clear_cache(void *start, void *end);
+    __clear_cache(address, end);
+#elif defined(__linux__)
+# if defined(__ARM_EABI__)
     register unsigned long beg __asm__("r0") = (unsigned long)address;
-    register unsigned long end __asm__("r1") = (unsigned long)address + nbytes;
+    register unsigned long end __asm__("r1") = (unsigned long)end;
     register unsigned long flg __asm__("r2") = 0;
     register unsigned long scno __asm__("r7") = 0xf0002;
     __asm__ __volatile__("swi 0"	/* sys_cacheflush() */
 			 : "=r"(beg)
 			 : "0"(beg), "r"(end), "r"(flg), "r"(scno));
-#else
+# else
     register unsigned long beg __asm__("r0") = (unsigned long)address;
-    register unsigned long end __asm__("r1") = (unsigned long)address + nbytes;
+    register unsigned long end __asm__("r1") = (unsigned long)end;
     register unsigned long flg __asm__("r2") = 0;
     __asm__ __volatile__("swi 0x9f0002"	/* sys_cacheflush() */
 			 : "=r"(beg)
 			 : "0"(beg), "r"(end), "r"(flg));
+# endif
+#else
+# error "Don't know how to flush instruction cache"
 #endif
 }
 
@@ -270,3 +286,5 @@ void hipe_arch_print_pcb(struct hipe_process_state *p)
     U("narity     ", narity);
 #undef U
 }
+
+#endif /*__arm__*/
diff --git a/erts/emulator/hipe/hipe_native_bif.c b/erts/emulator/hipe/hipe_native_bif.c
index 211ce0492a..80e5d81023 100644
--- a/erts/emulator/hipe/hipe_native_bif.c
+++ b/erts/emulator/hipe/hipe_native_bif.c
@@ -579,7 +579,7 @@ Eterm hipe_check_get_msg(Process *c_p)
 
     if (ERTS_SIG_IS_EXTERNAL_MSG(msgp)) {
         /* FIXME: bump appropriate amount... */
-        if (!erts_decode_dist_message(c_p, ERTS_PROC_LOCK_MAIN, msgp, 0)) {
+        if (!erts_proc_sig_decode_dist(c_p, ERTS_PROC_LOCK_MAIN, msgp, 0)) {
             /*
              * A corrupt distribution message that we weren't able to decode;
              * remove it...
diff --git a/erts/emulator/hipe/hipe_x86.h b/erts/emulator/hipe/hipe_x86.h
index 8967793171..a1fe75e792 100644
--- a/erts/emulator/hipe/hipe_x86.h
+++ b/erts/emulator/hipe/hipe_x86.h
@@ -22,17 +22,28 @@
 #ifndef HIPE_X86_H
 #define HIPE_X86_H
 
-static __inline__ void hipe_flush_icache_word(void *address)
-{
-    /* Do nothing. This works as long as compiled code is
-       executed by a single CPU thread. */
-}
+#ifndef __has_builtin
+# define __has_builtin(x) 0
+#endif
 
 static __inline__ void
 hipe_flush_icache_range(void *address, unsigned int nbytes)
 {
-    /* Do nothing. This works as long as compiled code is
-       executed by a single CPU thread. */
+    void* end = (char*)address + nbytes;
+
+#if ERTS_AT_LEAST_GCC_VSN__(4, 3, 0) || __has_builtin(__builtin___clear_cache)
+    __builtin___clear_cache(address, end);
+#elif defined(__clang__)
+    void __clear_cache(void *start, void *end);
+    __clear_cache(address, end);
+#else
+# warning "Don't know how to flush instruction cache"
+#endif
+}
+
+static __inline__ void hipe_flush_icache_word(void *address)
+{
+    hipe_flush_icache_range(address, sizeof(void*));
 }
 
 /* for stack descriptor hash lookup */
diff --git a/erts/emulator/internal_doc/CarrierMigration.md b/erts/emulator/internal_doc/CarrierMigration.md
index 3a796d11b7..40f6031ca8 100644
--- a/erts/emulator/internal_doc/CarrierMigration.md
+++ b/erts/emulator/internal_doc/CarrierMigration.md
@@ -1,6 +1,9 @@
 Carrier Migration
 =================
 
+Introduction
+------------
+
 The ERTS memory allocators manage memory blocks in two types of raw
 memory chunks. We call these chunks of raw memory
 *carriers*. Single-block carriers which only contain one large block,
@@ -34,8 +37,7 @@ Solution
 --------
 
 In order to prevent scenarios like this we've implemented support for
-migration of multi-block carriers between allocator instances of the
-same type.
+migration of multi-block carriers between allocator instances.
 
 ### Management of Free Blocks ###
 
@@ -130,10 +132,6 @@ threads may have references to it via the pool.
 
 ### Migration ###
 
-There exists one pool for each allocator type enabling migration of
-carriers between scheduler specific allocator instances of the same
-allocator type.
-
 Each allocator instance keeps track of the current utilization of its
 multi-block carriers. When the total utilization falls below the "abandon
 carrier utilization limit" it starts to inspect the utilization of the
@@ -146,11 +144,11 @@ Since the carrier has been unlinked from the data structure of
 available free blocks, no more allocations will be made in the
 carrier.
 
-The allocator instance that created a carrier is called its **owner**.
+The allocator instance that created a carrier is called its *owner*.
 Ownership never changes.
 
 The allocator instance that has the responsibility to perform deallocations in a
-carrier is called its **employer**. The employer may also perform allocations if
+carrier is called its *employer*. The employer may also perform allocations if
 the carrier is not in the pool. Employment may change when a carrier is fetched from
 or inserted into the pool.
 
@@ -158,14 +156,14 @@ Deallocations in a carrier, while it remains in the pool, is always performed
 the owner. That is, all pooled carriers are employed by their owners.
 
 Each carrier has an atomic word containing a pointer to the employing allocator
-instance and three bit flags; IN_POOL, BUSY and HOMECOMING.
+instance and three bit flags; IN\_POOL, BUSY and HOMECOMING.
 
 When fetching a carrier from the pool, employment may change and further
 deallocations in the carrier will be redirected to the new
 employer using the delayed dealloc functionality.
 
 When a foreign allocator instance abandons a carrier back into the pool, it will
-also pass it back to its **owner** using the delayed dealloc queue. When doing
+also pass it back to its *owner* using the delayed dealloc queue. When doing
 this it will set the HOMECOMING bit flag to mark it as "enqueued". The owner
 will later clear the HOMECOMING bit when the carrier is dequeued. This mechanism
 prevents a carrier from being enqueued again before it has been dequeued.
@@ -185,14 +183,14 @@ back to the owner for deallocation using the delayed dealloc functionality.
 
 In short:
 
-* The allocator instance that created a carrier **owns** it.
-* An empty carrier is always deallocated by its **owner**.
-* **Ownership** never changes.
-* The allocator instance that uses a carrier **employs** it.
-* An **employer** can abandon a carrier into the pool.
+* The allocator instance that created a carrier *owns* it.
+* An empty carrier is always deallocated by its *owner*.
+* *Ownership* never changes.
+* The allocator instance that uses a carrier *employs* it.
+* An *employer* can abandon a carrier into the pool.
 * Pooled carriers are not allocated from.
-* Pooled carriers are always **employed** by their **owner**.
-* **Employment** can only change from **owner** to a foreign allocator
+* Pooled carriers are always *employed* by their *owner*.
+* *Employment* can only change from *owner* to a foreign allocator
   when a carrier is fetched from the pool.
 
 
@@ -208,8 +206,8 @@ limited. We only inspect a limited number of carriers. If none of
 those carriers had a free block large enough to satisfy the allocation
 request, the search will fail. A carrier in the pool can also be BUSY
 if another thread is currently doing block deallocation work on the
-carrier. A BUSY carrier will also be skipped by the search as it can
-not satisfy the request. The pool is lock-free and we do not want to
+carrier. A BUSY carrier will also be skipped by the search as it cannot
+satisfy the request. The pool is lock-free and we do not want to
 block, waiting for the other thread to finish.
 
 ### The bad cluster problem ###
@@ -234,7 +232,7 @@ carrier. When the cluster gets to the same size as the search limit,
 all searches will essentially fail.
 
 To counter the "bad cluster" problem and also ease the contention, the
-search will now always start by first looking at the allocators **own**
+search will now always start by first looking at the allocators *own*
 carriers. That is, carriers that were initially created by the
 allocator itself and later had been abandoned to the pool. If none of
 our own abandoned carrier would do, then the search continues into the
@@ -287,11 +285,3 @@ reduced using the `aoffcbf` strategy. A trade off between memory
 consumption and performance is however inevitable, and it is up to
 the user to decide what is most important. 
 
-Further work
-------------
-
-It would be quite easy to extend this to allow migration of multi-block
-carriers between all allocator types. More or less the only obstacle
-is maintenance of the statistics information.
-
-
diff --git a/erts/emulator/internal_doc/CodeLoading.md b/erts/emulator/internal_doc/CodeLoading.md
index 151b9cd57c..0b2e3070e7 100644
--- a/erts/emulator/internal_doc/CodeLoading.md
+++ b/erts/emulator/internal_doc/CodeLoading.md
@@ -45,7 +45,7 @@ free to schedule other work while the second loader is waiting. (See
 `erts_release_code_write_permission`).
 
 The ability to prepare several modules in parallel is not currently
-used as almost all code loading is serialized by the code_server
+used as almost all code loading is serialized by the code\_server
 process. The BIF interface is however prepared for this.
 
       erlang:prepare_loading(Module, Code) -> LoaderState
@@ -71,8 +71,8 @@ structures. These *code access structures* are
 
 * Export table. One entry for every exported function.
 * Module table. One entry for each loaded module.
-* "beam_catches". Identifies jump destinations for catch instructions.
-* "beam_ranges". Map code address to function and line in source file.
+* "beam\_catches". Identifies jump destinations for catch instructions.
+* "beam\_ranges". Map code address to function and line in source file.
 
 The most frequently used of these structures is the export table that
 is accessed in run time for every executed external function call to
diff --git a/erts/emulator/internal_doc/CountingInstructions.md b/erts/emulator/internal_doc/CountingInstructions.md
new file mode 100644
index 0000000000..d4b1213d00
--- /dev/null
+++ b/erts/emulator/internal_doc/CountingInstructions.md
@@ -0,0 +1,53 @@
+Counting Instructions
+=====================
+
+Here is an example that shows how to count how many times each
+instruction is executed:
+
+    $ (cd erts/emulator && make icount)
+     MAKE	icount
+    make[1]: Entering directory `/home/uabbgus/otp/erts/emulator'
+      .
+      .
+      .
+    make[1]: Leaving directory `/home/uabbgus/otp/erts/emulator'
+    $ cat t.erl
+    -module(t).
+    -compile([export_all,nowarn_export_all]).
+
+    count() ->
+        erts_debug:ic(fun benchmark/0).
+
+    benchmark() ->
+        %% Run dialyzer.
+        Root = code:root_dir(),
+        Wc1 = filename:join(Root, "lib/{kernel,stdlib}/ebin/*.beam"),
+        Wc2 = filename:join(Root, "erts/preloaded/ebin/*.beam"),
+        Files = filelib:wildcard(Wc1) ++ filelib:wildcard(Wc2),
+        Opts = [{analysis_type,plt_build},{files,Files},{get_warnings,true}],
+        dialyzer:run(Opts).
+    $ $ERL_TOP/bin/cerl -icount
+    Erlang/OTP 22 [RELEASE CANDIDATE 1] [erts-10.2.4] [source-ac0d451] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe] [instruction-counting]
+
+    Eshell V10.2.4  (abort with ^G)
+    1> c(t).
+    {ok,t}
+    2> t:count().
+               0 badarg_j
+               0 badmatch_x
+               0 bs_add_jsstx
+               0 bs_context_to_binary_x
+                .
+                .
+                .
+       536461394 move_call_last_yfQ
+       552405176 allocate_tt
+       619920327 i_is_eq_exact_immed_frc
+       636419163 is_nonempty_list_allocate_frtt
+       641859278 i_get_tuple_element_xPx
+       678196718 move_return_c
+       786289914 is_tagged_tuple_frAa
+       865826424 i_call_f
+    Total: 20728870321
+    []
+    3>
diff --git a/erts/emulator/internal_doc/GarbageCollection.md b/erts/emulator/internal_doc/GarbageCollection.md
index 1d9e3f4160..a1627b3233 100644
--- a/erts/emulator/internal_doc/GarbageCollection.md
+++ b/erts/emulator/internal_doc/GarbageCollection.md
@@ -1,6 +1,6 @@
 # Erlang Garbage Collector
 
-Erlang manages dynamic memory with a [tracing garbage collector](https://en.wikipedia.org/wiki/Tracing_garbage_collection). More precisely a per process generational semi-space copying collector using [Cheney's](#cheney) copy collection algorithm together with a global large object space.
+Erlang manages dynamic memory with a [tracing garbage collector](https://en.wikipedia.org/wiki/Tracing_garbage_collection). More precisely a per process generational semi-space copying collector using Cheney's copy collection algorithm together with a global large object space. (See C. J. Cheney in [References](#references).)
 
 ## Overview
 
@@ -12,12 +12,11 @@ Terms are created on the heap by evaluating expressions. There are two major typ
 
 Let's look at an example that returns a tuple with the newly created data.
 
-```erlang
-data(Foo) ->
-   Cons = [42|Foo],
-   Literal = {text, "hello world!"},
-   {tag, Cons, Literal}.
-```
+
+    data(Foo) ->
+       Cons = [42|Foo],
+       Literal = {text, "hello world!"},
+       {tag, Cons, Literal}.
 
 In this example we first create a new cons cell with an integer and a tuple with some text. Then a tuple of size three wrapping the other values with an atom tag is created and returned.
 
@@ -25,7 +24,6 @@ On the heap tuples require a word size for each of its elements as well as for t
 
 Compiling this code to beam assembly (`erlc -S`) shows exactly what is happening.
 
-```erlang
     ...
     {test_heap,6,1}.
     {put_list,{integer,42},{x,0},{x,1}}.
@@ -34,9 +32,8 @@ Compiling this code to beam assembly (`erlc -S`) shows exactly what is happening
     {put,{x,1}}.
     {put,{literal,{text,"hello world!"}}}.
     return.
-```
 
-Looking at the assembler code we can see three things; The heap requirement in this function turns out to be only six words, as seen by the `{test_heap,6,1}` instruction. All the allocations are combined to a single instruction. The bulk of the data `{text, "hello world!"}` is a *literal*. Literals, sometimes referred to as constants, are not allocated in the function since they are a part of the module and allocated at load time.
+Looking at the assembler code we can see three things: The heap requirement in this function turns out to be only six words, as seen by the `{test_heap,6,1}` instruction. All the allocations are combined to a single instruction. The bulk of the data `{text, "hello world!"}` is a *literal*. Literals, sometimes referred to as constants, are not allocated in the function since they are a part of the module and allocated at load time.
 
 If there is not enough space available on the heap to satisfy the `test_heap` instructions request for memory, then a garbage collection is initiated. It may happen immediately in the `test_heap` instruction, or it can be delayed until a later time depending on what state the process is in. If the garbage collection is delayed, any memory needed will be allocated in heap fragments. Heap fragments are extra memory blocks that are a part of the young heap, but are not allocated in the contigious area where terms normally reside. See [The young heap](#the-young-heap) for more details.
 
@@ -50,11 +47,9 @@ It follows all the pointers from the root-set to the heap and copies each term w
 
 After the header word has been copied a [*move marker*](https://github.com/erlang/otp/blob/OTP-18.0/erts/emulator/beam/erl_gc.h#L45-L46) is destructively placed in it pointing to the term in the *to space*. Any other term that points to the already moved term will [see this move marker](https://github.com/erlang/otp/blob/OTP-18.0/erts/emulator/beam/erl_gc.c#L1125) and copy the referring pointer instead. For example, if the have the following Erlang code:
 
-```erlang
-foo(Arg) ->
-    T = {test, Arg},
-    {wrapper, T, T, T}.
-```
+    foo(Arg) ->
+        T = {test, Arg},
+        {wrapper, T, T, T}.
 
 Only one copy of T exists on the heap and during the garbage collection only the first time T is encountered will it be copied.
 
@@ -86,15 +81,15 @@ In the next garbage collection, any pointers to the old heap will be ignored and
 
 Generational garbage collection aims to increase performance at the expense of memory. This is achieved because only the young, smaller, heap is considered in most garbage collections.
 
-The generational [hypothesis](#ungar) predicts that most terms tend to die young, and for an immutable language such as Erlang, young terms die even faster than in other languages. So for most usage patterns the data in the new heap will die very soon after it is allocated. This is good because it limits the amount of data copied to the old heap and also because the garbage collection algorithm used is proportional to the amount of live data on the heap.
+The generational hypothesis predicts that most terms tend to die young (see D. Ungar in [References](#references)), and for an immutable language such as Erlang, young terms die even faster than in other languages. So for most usage patterns the data in the new heap will die very soon after it is allocated. This is good because it limits the amount of data copied to the old heap and also because the garbage collection algorithm used is proportional to the amount of live data on the heap.
 
 One critical issue to note here is that any term on the young heap can reference terms on the old heap but *no* term on the old heap may refer to a term on the young heap. This is due to the nature of the copy algorithm. Anything referenced by an old heap term is not included in the reference tree, root-set and its followers, and hence is not copied. If it was, the data would be lost, fire and brimstone would rise to cover the earth. Fortunately, this comes naturally for Erlang because the terms are immutable and thus there can be no pointers modified on the old heap to point to the young heap.
 
-To reclaim data from the old heap, both young and old heaps are included during the collection and copied to a common *to space*. Both the *from space* of the young and old heap are then deallocated and the procedure will start over from the beginning. This type of garbage collection is called a full sweep and is triggered when the size of the area under the high-watermark is larger than the size of the free area of the old heap. It can also be triggered by doing a manual call to [erlang:garbage_collect()](http://erlang.org/doc/man/erlang.html#garbage_collect-0), or by running into the young garbage collection limit set by [spawn_opt(fun(),[{fullsweep_after, N}])](http://erlang.org/doc/man/erlang.html#spawn_opt-4) where N is the number of young garbage collections to do before forcing a garbage collection of both young and old heap.
+To reclaim data from the old heap, both young and old heaps are included during the collection and copied to a common *to space*. Both the *from space* of the young and old heap are then deallocated and the procedure will start over from the beginning. This type of garbage collection is called a full sweep and is triggered when the size of the area under the high-watermark is larger than the size of the free area of the old heap. It can also be triggered by doing a manual call to [erlang:garbage_collect()](http://erlang.org/doc/man/erlang.html#garbage_collect-0), or by running into the young garbage collection limit set by [spawn\_opt(fun(),[{fullsweep\_after, N}\])](http://erlang.org/doc/man/erlang.html#spawn_opt-4) where N is the number of young garbage collections to do before forcing a garbage collection of both young and old heap.
 
 ## The young heap
 
-The young heap, or the allocation heap, consists of the stack and heap as described in the Overview. However, it also includes any heap fragments that are attached to the heap. All of the heap fragments are considered to be above the high-watermark and part of the young generation. Heap fragments contain terms that either did not fit on the heap, or were created by another process and then attached to the heap. For instance if the bif binary_to_term created a term which does not fit on the current heap without doing a garbage collection, it will create a heap-fragment for the term and then schedule a garbage collection for later. Also if a message is sent to the process, the payload may be placed in a heap-fragment and that fragment is added to young heap when the message is matched in a receive clause.
+The young heap, or the allocation heap, consists of the stack and heap as described in the Overview. However, it also includes any heap fragments that are attached to the heap. All of the heap fragments are considered to be above the high-watermark and part of the young generation. Heap fragments contain terms that either did not fit on the heap, or were created by another process and then attached to the heap. For instance if the bif `binary_to_term/1` created a term which does not fit on the current heap without doing a garbage collection, it will create a heap-fragment for the term and then schedule a garbage collection for later. Also if a message is sent to the process, the payload may be placed in a heap-fragment and that fragment is added to young heap when the message is matched in a receive clause.
 
 This procedure differs from how it worked prior to Erlang/OTP 19.0. Before 19.0, only a contiguous memory block where the young heap and stack resided was considered to be part of the young heap. Heap fragments and messages were immediately copied into the young heap before they could be inspected by the Erlang program. The behaviour introduced in 19.0 is superior in many ways - most significantly it reduces the number of necessary copy operations and the root set for garbage collection.
 
@@ -118,21 +113,19 @@ The old heap is always one step ahead in the heap growth stages than the young h
 
 When garbage collecting a heap (young or old) all literals are left in place and not copied. To figure out if a term should be copied or not when doing a garbage collection the following pseudo code is used:
 
-```c
-if (erts_is_literal(ptr) || (on_old_heap(ptr) && !fullsweep)) {
-  /* literal or non fullsweep - do not copy */
-} else {
-  copy(ptr);
-}
-```
+    if (erts_is_literal(ptr) || (on_old_heap(ptr) && !fullsweep)) {
+      /* literal or non fullsweep - do not copy */
+    } else {
+      copy(ptr);
+    }
 
 The [`erts_is_literal`](https://github.com/erlang/otp/blob/OTP-19.0/erts/emulator/beam/global.h#L1452-L1465) check works differently on different architectures and operating systems.
 
-On 64 bit systems that allow mapping of unreserved virtual memory areas (most operating systems except Windows), an area of size 1 GB (by default) is mapped and then all literals are placed within that area. Then all that has to be done to determine if something is a literal or not is [two quick pointer checks](https://github.com/erlang/otp/blob/OTP-19.0/erts/emulator/beam/erl_alloc.h#L322-L324). This system relies on the fact that a memory page that has not been touched yet does not take any actual space. So even if 1 GB of virtual memory is mapped, only the memory which is actually needed for literals is allocated in ram. The size of the literal area is configurable through the +MIscs erts_alloc option.
+On 64 bit systems that allow mapping of unreserved virtual memory areas (most operating systems except Windows), an area of size 1 GB (by default) is mapped and then all literals are placed within that area. Then all that has to be done to determine if something is a literal or not is [two quick pointer checks](https://github.com/erlang/otp/blob/OTP-19.0/erts/emulator/beam/erl_alloc.h#L322-L324). This system relies on the fact that a memory page that has not been touched yet does not take any actual space. So even if 1 GB of virtual memory is mapped, only the memory which is actually needed for literals is allocated in ram. The size of the literal area is configurable through the +MIscs erts\_alloc option.
 
 On 32 bit systems, there is not enough virtual memory space to allocate 1 GB for just literals, so instead small 256 KB sized literal regions are created on demand and a card mark bit-array of the entire 32 bit memory space is then used to determine if a term is a literal or not. Since the total memory space is only 32 bits, the card mark bit-array is only 256 words large. On a 64 bit system the same bit-array would have to be 1 tera words large, so this technique is only viable on 32 bit systems. Doing [lookups in the array](https://github.com/erlang/otp/blob/OTP-19.0/erts/emulator/beam/erl_alloc.h#L316-L319) is a little more expensive then just doing the pointer checks that can be done in 64 bit systems, but not extremely so.
 
-On 64 bit windows, on which erts_alloc cannot do unreserved virtual memory mappings, a [special tag](https://github.com/erlang/otp/blob/OTP-19.0/erts/emulator/beam/erl_term.h#L59) within the Erlang term object is used to determine if something [is a literal or not](https://github.com/erlang/otp/blob/OTP-19.0/erts/emulator/beam/erl_term.h#L248-L252). This is very cheap, however, the tag is only available on 64 bit machines, and it is possible to do a great deal of other nice optimizations with this tag in the future (like for instance a more compact list implementation) so it is not used on operating systems where it is not needed.
+On 64 bit windows, on which erts\_alloc cannot do unreserved virtual memory mappings, a [special tag](https://github.com/erlang/otp/blob/OTP-19.0/erts/emulator/beam/erl_term.h#L59) within the Erlang term object is used to determine if something [is a literal or not](https://github.com/erlang/otp/blob/OTP-19.0/erts/emulator/beam/erl_term.h#L248-L252). This is very cheap, however, the tag is only available on 64 bit machines, and it is possible to do a great deal of other nice optimizations with this tag in the future (like for instance a more compact list implementation) so it is not used on operating systems where it is not needed.
 
 This behaviour is different from how it worked prior to Erlang/OTP 19.0. Before 19.0 the literal check was done by checking if the pointer pointed to the young or old heap block. If it did not, then it was considered a literal. This lead to considerable overhead and strange memory usage scenarios, so it was removed in 19.0.
 
@@ -182,6 +175,8 @@ Using `on_heap` will force all messages to be part of on the young heap which wi
 
 Which one of these strategies is best depends a lot on what the process is doing and how it interacts with other processes. So, as always, profile the application and see how it behaves with the different options.
 
-   <a name="cheney">[1]</a>: C. J. Cheney. A nonrecursive list compacting algorithm. Commun. ACM, 13(11):677–678, Nov. 1970.
+## References
+
+C. J. Cheney. A nonrecursive list compacting algorithm. Commun. ACM, 13(11):677–678, Nov. 1970.
 
-   <a name="ungar">[2]</a>: D. Ungar. Generation scavenging: A non-disruptive high performance storage reclamation algorithm. SIGSOFT Softw. Eng. Notes, 9(3):157–167, Apr. 1984.
+D. Ungar. Generation scavenging: A non-disruptive high performance storage reclamation algorithm. SIGSOFT Softw. Eng. Notes, 9(3):157–167, Apr. 1984.
diff --git a/erts/emulator/internal_doc/PTables.md b/erts/emulator/internal_doc/PTables.md
index 6fe0e7665d..ef61963a40 100644
--- a/erts/emulator/internal_doc/PTables.md
+++ b/erts/emulator/internal_doc/PTables.md
@@ -85,13 +85,13 @@ following:
 3.  Depending on use, issue appropriate memory barrier.
 
     A common barrier used is a barrier with acquire semantics. On
-    x86/x86_64 this maps to a compiler barrier preventing the compiler
+    x86/x86\_64 this maps to a compiler barrier preventing the compiler
     to reorder instructions, but on other hardware often some kind of
     light weight hardware memory barrier is also needed.
 
     When comparing with a locked approach, at least one heavy weight
     memory barrier will be issued when locking the lock on most, if
-    not all, hardware architectures (including x86/x86_64), and often
+    not all, hardware architectures (including x86/x86\_64), and often
     some kind of light weight memory barrier will be issued when
     unlocking the lock. 
 
diff --git a/erts/emulator/internal_doc/SuperCarrier.md b/erts/emulator/internal_doc/SuperCarrier.md
index acf722ea37..f52c6613d5 100644
--- a/erts/emulator/internal_doc/SuperCarrier.md
+++ b/erts/emulator/internal_doc/SuperCarrier.md
@@ -5,7 +5,7 @@ A super carrier is large memory area, allocated at VM start, which can
 be used during runtime to allocate normal carriers from.
 
 The super carrier feature was introduced in OTP R16B03. It is
-enabled with command line option +MMscs <size in Mb>
+enabled with command line option +MMscs &lt;size in Mb&gt;
 and can be configured with other options.
 
 Problem
@@ -65,7 +65,7 @@ carrier is full.
 
 ### Implementation ###
 
-The entire super carrier implementation is kept in erl_mmap.c. The
+The entire super carrier implementation is kept in erl\_mmap.c. The
 name suggest that it can be viewed as our own mmap implementation.
 
 A super carrier needs to satisfy two slightly different kinds of
@@ -98,8 +98,8 @@ other.
 
 ### Data structures ###
 
-The MBC area is called **sa** as in super aligned and the SBC area is
-called **sua** as in super un-aligned.
+The MBC area is called *sa* as in super aligned and the SBC area is
+called *sua* as in super un-aligned.
 
 Note that the "super" in super alignment and the "super" in super
 carrier has nothing to do with each other. We could have choosen
@@ -128,7 +128,7 @@ down or up.
 We need to keep track of all the free segments in order to reuse them
 for new carrier allocations. One initial idea was to use the same
 mechanism that is used to keep track of free blocks within MBCs
-(alloc_util and the different strategies). However, that would not be
+(alloc\_util and the different strategies). However, that would not be
 as straight forward as one can think and can also waste quite a lot of
 memory as it uses prepended block headers. The granularity of the
 super carrier is one memory page (usually 4kb). We want to allocate
diff --git a/erts/emulator/internal_doc/Tracing.md b/erts/emulator/internal_doc/Tracing.md
index 7f97f64765..196ae0dd4e 100644
--- a/erts/emulator/internal_doc/Tracing.md
+++ b/erts/emulator/internal_doc/Tracing.md
@@ -37,6 +37,7 @@ what different type of break actions that are enabled.
 
 Same Same but Different
 -----------------------
+
 Even though `trace_pattern` use the same technique as the non-blocking
 code loading with replicated generations of data structures and an
 atomic switch, the implementations are quite separate from each
@@ -72,6 +73,7 @@ aligned write operation on all hardware architectures we use.
 
 Adding a new Breakpoint
 -----------------------
+
 This is a simplified sequence describing what `trace_pattern` goes
 through when adding a new breakpoint.
 
@@ -82,7 +84,7 @@ through when adding a new breakpoint.
    instruction word in the breakpoint.
 
 3. Write a pointer to the breakpoint at offset -4 from the first
-   instruction "func_info" header.
+   instruction "func\_info" header.
 
 4. Set the staging part of the breakpoint as enabled with specified
    breakpoint data.
@@ -139,7 +141,7 @@ and removing breakpoints.
 
 2. Allocate new breakpoint structures with a disabled active part and
    the original beam instruction. Write a pointer to the breakpoint in
-   "func_info" header at offset -4.
+   "func\_info" header at offset -4.
 
 3. Update the staging part of all affected breakpoints. Disable
    breakpoints that are to be removed.
diff --git a/erts/emulator/internal_doc/beam_makeops.md b/erts/emulator/internal_doc/beam_makeops.md
index 1da8d2ab05..2880099b70 100644
--- a/erts/emulator/internal_doc/beam_makeops.md
+++ b/erts/emulator/internal_doc/beam_makeops.md
@@ -403,7 +403,7 @@ A line with `//` is also a comment.  It is recommended to only
 use this style of comments in files that define implementations of
 instructions.
 
-A long line can be broken into shorter lines by a placing a`\` before
+A long line can be broken into shorter lines by a placing a `\` before
 the newline.
 
 ### Variable definitions ###
@@ -1159,7 +1159,6 @@ implementation of `gen_element()`:
 
         return op;
     }
-}
 
 ### Defining the implementation ###
 
@@ -1452,7 +1451,7 @@ optionally additional heap space.
 
 ##### The NEXT_INSTRUCTION pre-bound variable #####
 
-The NEXT_INSTRUCTION is a pre-bound variable that is available in
+The NEXT\_INSTRUCTION is a pre-bound variable that is available in
 all instructions.  It expands to the address of the next instruction.
 
 Here is an example:
@@ -1545,7 +1544,7 @@ register, the pointer will no longer be valid.  (Y registers are
 stored on the stack.)
 
 In those circumstances, `$REFRESH_GEN_DEST()` must be invoked
-to set up the pointer again.  **beam\_makeops** will notice
+to set up the pointer again. **beam\_makeops** will notice
 if there is a call to a function that does a garbage collection and
 `$REFRESH_GEN_DEST()` is not called.
 
diff --git a/erts/emulator/nifs/common/prim_file_nif.c b/erts/emulator/nifs/common/prim_file_nif.c
index b34bf11205..3df04e42e2 100644
--- a/erts/emulator/nifs/common/prim_file_nif.c
+++ b/erts/emulator/nifs/common/prim_file_nif.c
@@ -38,7 +38,6 @@ static void unload(ErlNifEnv *env, void* priv_data);
 
 static ErlNifResourceType *efile_resource_type;
 
-static ERL_NIF_TERM am_erts_prim_file;
 static ERL_NIF_TERM am_close;
 
 static ERL_NIF_TERM am_ok;
@@ -220,7 +219,6 @@ static int load(ErlNifEnv *env, void** priv_data, ERL_NIF_TERM prim_file_pid)
         ASSERT(!"bad pid passed to prim_file_nif");
     }
 
-    am_erts_prim_file = enif_make_atom(env, "erts_prim_file");
     am_close = enif_make_atom(env, "close");
 
     am_ok = enif_make_atom(env, "ok");
@@ -478,7 +476,8 @@ static ERL_NIF_TERM open_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]
     ERL_NIF_TERM result;
     efile_path_t path;
 
-    if(argc != 2 || !enif_is_list(env, argv[1])) {
+    ASSERT(argc == 2);
+    if(!enif_is_list(env, argv[1])) {
         return enif_make_badarg(env);
     }
 
@@ -553,7 +552,8 @@ static ERL_NIF_TERM read_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, con
     SysIOVec read_vec[1];
     ErlNifBinary result;
 
-    if(argc != 1 || !enif_is_number(env, argv[0])) {
+    ASSERT(argc == 1);
+    if(!enif_is_number(env, argv[0])) {
         return enif_make_badarg(env);
     }
 
@@ -591,7 +591,8 @@ static ERL_NIF_TERM write_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, co
     Sint64 bytes_written;
     ERL_NIF_TERM tail;
 
-    if(argc != 1 || !enif_inspect_iovec(env, 64, argv[0], &tail, &input)) {
+    ASSERT(argc == 1);
+    if(!enif_inspect_iovec(env, 64, argv[0], &tail, &input)) {
         return enif_make_badarg(env);
     }
 
@@ -614,8 +615,8 @@ static ERL_NIF_TERM pread_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, co
     SysIOVec read_vec[1];
     ErlNifBinary result;
 
-    if(argc != 2 || !enif_is_number(env, argv[0])
-                 || !enif_is_number(env, argv[1])) {
+    ASSERT(argc == 2);
+    if(!enif_is_number(env, argv[0]) || !enif_is_number(env, argv[1])) {
         return enif_make_badarg(env);
     }
 
@@ -654,8 +655,9 @@ static ERL_NIF_TERM pwrite_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, c
     Sint64 bytes_written, offset;
     ERL_NIF_TERM tail;
 
-    if(argc != 2 || !enif_is_number(env, argv[0])
-                 || !enif_inspect_iovec(env, 64, argv[1], &tail, &input)) {
+    ASSERT(argc == 2);
+    if(!enif_is_number(env, argv[0])
+       || !enif_inspect_iovec(env, 64, argv[1], &tail, &input)) {
         return enif_make_badarg(env);
     }
 
@@ -682,7 +684,8 @@ static ERL_NIF_TERM seek_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, con
     Sint64 new_position, offset;
     enum efile_seek_t seek;
 
-    if(argc != 2 || !enif_get_int64(env, argv[1], &offset)) {
+    ASSERT(argc == 2);
+    if(!enif_get_int64(env, argv[1], &offset)) {
         return enif_make_badarg(env);
     }
 
@@ -706,7 +709,8 @@ static ERL_NIF_TERM seek_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, con
 static ERL_NIF_TERM sync_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
     int data_only;
 
-    if(argc != 1 || !enif_get_int(env, argv[0], &data_only)) {
+    ASSERT(argc == 1);
+    if(!enif_get_int(env, argv[0], &data_only)) {
         return enif_make_badarg(env);
     }
 
@@ -718,9 +722,7 @@ static ERL_NIF_TERM sync_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, con
 }
 
 static ERL_NIF_TERM truncate_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
-    if(argc != 0) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 0);
 
     if(!efile_truncate(d)) {
         return posix_error_to_tuple(env, d->posix_errno);
@@ -732,8 +734,8 @@ static ERL_NIF_TERM truncate_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc,
 static ERL_NIF_TERM allocate_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
     Sint64 offset, length;
 
-    if(argc != 2 || !enif_is_number(env, argv[0])
-                 || !enif_is_number(env, argv[1])) {
+    ASSERT(argc == 2);
+    if(!enif_is_number(env, argv[0]) || !enif_is_number(env, argv[1])) {
         return enif_make_badarg(env);
     }
 
@@ -754,8 +756,8 @@ static ERL_NIF_TERM advise_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, c
     enum efile_advise_t advise;
     Sint64 offset, length;
 
-    if(argc != 3 || !enif_is_number(env, argv[0])
-                 || !enif_is_number(env, argv[1])) {
+    ASSERT(argc == 3);
+    if(!enif_is_number(env, argv[0]) || !enif_is_number(env, argv[1])) {
         return enif_make_badarg(env);
     }
 
@@ -818,8 +820,8 @@ static ERL_NIF_TERM ipread_s32bu_p32bu_nif_impl(efile_data_t *d, ErlNifEnv *env,
 
     ErlNifBinary payload;
 
-    if(argc != 2 || !enif_is_number(env, argv[0])
-                 || !enif_is_number(env, argv[1])) {
+    ASSERT(argc == 2);
+    if(!enif_is_number(env, argv[0]) || !enif_is_number(env, argv[1])) {
         return enif_make_badarg(env);
     }
 
@@ -886,9 +888,7 @@ static ERL_NIF_TERM ipread_s32bu_p32bu_nif_impl(efile_data_t *d, ErlNifEnv *env,
 }
 
 static ERL_NIF_TERM get_handle_nif_impl(efile_data_t *d, ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
-    if(argc != 0) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 0);
 
     return efile_get_handle(env, d);
 }
@@ -900,7 +900,8 @@ static ERL_NIF_TERM read_info_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM a
     efile_path_t path;
     int follow_links;
 
-    if(argc != 2 || !enif_get_int(env, argv[1], &follow_links)) {
+    ASSERT(argc == 2);
+    if(!enif_get_int(env, argv[1], &follow_links)) {
         return enif_make_badarg(env);
     }
 
@@ -933,9 +934,10 @@ static ERL_NIF_TERM set_permissions_nif(ErlNifEnv *env, int argc, const ERL_NIF_
     posix_errno_t posix_errno;
 
     efile_path_t path;
-    Uint permissions;
+    unsigned int permissions;
 
-    if(argc != 2 || !enif_get_uint(env, argv[1], &permissions)) {
+    ASSERT(argc == 2);
+    if(!enif_get_uint(env, argv[1], &permissions)) {
         return enif_make_badarg(env);
     }
 
@@ -952,10 +954,10 @@ static ERL_NIF_TERM set_owner_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM a
     posix_errno_t posix_errno;
 
     efile_path_t path;
-    Sint uid, gid;
+    int uid, gid;
 
-    if(argc != 3 || !enif_get_int(env, argv[1], &uid)
-                 || !enif_get_int(env, argv[2], &gid)) {
+    ASSERT(argc == 3);
+    if(!enif_get_int(env, argv[1], &uid) || !enif_get_int(env, argv[2], &gid)) {
         return enif_make_badarg(env);
     }
 
@@ -974,9 +976,10 @@ static ERL_NIF_TERM set_time_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM ar
     Sint64 accessed, modified, created;
     efile_path_t path;
 
-    if(argc != 4 || !enif_get_int64(env, argv[1], &accessed)
-                 || !enif_get_int64(env, argv[2], &modified)
-                 || !enif_get_int64(env, argv[3], &created)) {
+    ASSERT(argc == 4);
+    if(!enif_get_int64(env, argv[1], &accessed)
+       || !enif_get_int64(env, argv[2], &modified)
+       || !enif_get_int64(env, argv[3], &created)) {
         return enif_make_badarg(env);
     }
 
@@ -995,9 +998,7 @@ static ERL_NIF_TERM read_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM a
     efile_path_t path;
     ERL_NIF_TERM result;
 
-    if(argc != 1) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 1);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1014,9 +1015,7 @@ static ERL_NIF_TERM list_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM ar
     efile_path_t path;
     ERL_NIF_TERM result;
 
-    if(argc != 1) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 1);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1032,9 +1031,7 @@ static ERL_NIF_TERM rename_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv
 
     efile_path_t existing_path, new_path;
 
-    if(argc != 2) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 2);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &existing_path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1052,9 +1049,7 @@ static ERL_NIF_TERM make_hard_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_T
 
     efile_path_t existing_path, new_path;
 
-    if(argc != 2) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 2);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &existing_path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1072,9 +1067,7 @@ static ERL_NIF_TERM make_soft_link_nif(ErlNifEnv *env, int argc, const ERL_NIF_T
 
     efile_path_t existing_path, new_path;
 
-    if(argc != 2) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 2);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &existing_path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1092,9 +1085,7 @@ static ERL_NIF_TERM make_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM ar
 
     efile_path_t path;
 
-    if(argc != 1) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 1);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1110,9 +1101,7 @@ static ERL_NIF_TERM del_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM ar
 
     efile_path_t path;
 
-    if(argc != 1) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 1);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1128,9 +1117,7 @@ static ERL_NIF_TERM del_dir_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM arg
 
     efile_path_t path;
 
-    if(argc != 1) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 1);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1147,7 +1134,8 @@ static ERL_NIF_TERM get_device_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_T
     ERL_NIF_TERM result;
     int device_index;
 
-    if(argc != 1 || !enif_get_int(env, argv[0], &device_index)) {
+    ASSERT(argc == 1);
+    if(!enif_get_int(env, argv[0], &device_index)) {
         return enif_make_badarg(env);
     }
 
@@ -1162,9 +1150,7 @@ static ERL_NIF_TERM get_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM arg
     posix_errno_t posix_errno;
     ERL_NIF_TERM result;
 
-    if(argc != 0) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 0);
 
     if((posix_errno = efile_get_cwd(env, &result))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1178,9 +1164,7 @@ static ERL_NIF_TERM set_cwd_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM arg
 
     efile_path_t path;
 
-    if(argc != 1) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 1);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1256,9 +1240,7 @@ static ERL_NIF_TERM read_file_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM a
 
     ErlNifBinary result;
 
-    if(argc != 1) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 1);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &path))) {
         return posix_error_to_tuple(env, posix_errno);
@@ -1286,9 +1268,7 @@ static ERL_NIF_TERM altname_nif(ErlNifEnv *env, int argc, const ERL_NIF_TERM arg
     efile_path_t path;
     ERL_NIF_TERM result;
 
-    if(argc != 1) {
-        return enif_make_badarg(env);
-    }
+    ASSERT(argc == 1);
 
     if((posix_errno = efile_marshal_path(env, argv[0], &path))) {
         return posix_error_to_tuple(env, posix_errno);
diff --git a/erts/emulator/nifs/common/prim_net_nif.c b/erts/emulator/nifs/common/prim_net_nif.c
new file mode 100644
index 0000000000..11a8ff724e
--- /dev/null
+++ b/erts/emulator/nifs/common/prim_net_nif.c
@@ -0,0 +1,1656 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : The NIF (C) part of the net interface
+ *            This is a module of miscellaneous functions.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#define STATIC_ERLANG_NIF 1
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* If we HAVE_SCTP_H and Solaris, we need to define the following in
+ * order to get SCTP working:
+ */
+#if (defined(HAVE_SCTP_H) && defined(__sun) && defined(__SVR4))
+#define SOLARIS10    1
+/* WARNING: This is not quite correct, it may also be Solaris 11! */
+#define _XPG4_2
+#define __EXTENSIONS__
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <time.h>
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_SYS_UIO_H
+#include <sys/uio.h>
+#endif
+
+#ifdef HAVE_NET_IF_DL_H
+#include <net/if_dl.h>
+#endif
+
+#ifdef HAVE_IFADDRS_H
+#include <ifaddrs.h>
+#endif
+
+#ifdef HAVE_NETPACKET_PACKET_H
+#include <netpacket/packet.h>
+#endif
+
+#ifdef HAVE_SYS_UN_H
+#include <sys/un.h>
+#endif
+
+/* SENDFILE STUFF HERE IF WE NEED IT... */
+
+#if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__)
+#define __DARWIN__ 1
+#endif
+
+
+#ifdef __WIN32__
+#define STRNCASECMP               strncasecmp
+#define INCL_WINSOCK_API_TYPEDEFS 1
+
+#ifndef WINDOWS_H_INCLUDES_WINSOCK2_H
+#include <winsock2.h>
+#endif
+#include <windows.h>
+#include <Ws2tcpip.h>   /* NEED VC 6.0 or higher */
+
+/* Visual studio 2008+: NTDDI_VERSION needs to be set for iphlpapi.h
+ * to define the right structures. It needs to be set to WINXP (or LONGHORN)
+ * for IPV6 to work and it's set lower by default, so we need to change it.
+ */
+#ifdef HAVE_SDKDDKVER_H
+#  include <sdkddkver.h>
+#  ifdef NTDDI_VERSION
+#    undef NTDDI_VERSION
+#  endif
+#  define NTDDI_VERSION NTDDI_WINXP
+#endif
+#include <iphlpapi.h>
+
+#undef WANT_NONBLOCKING
+#include "sys.h"
+
+#else /* !__WIN32__ */
+
+#include <sys/time.h>
+#ifdef NETDB_H_NEEDS_IN_H
+#include <netinet/in.h>
+#endif
+#include <netdb.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#ifdef DEF_INADDR_LOOPBACK_IN_RPC_TYPES_H
+#include <rpc/types.h>
+#endif
+
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <arpa/inet.h>
+
+#include <sys/param.h>
+#ifdef HAVE_ARPA_NAMESER_H
+#include <arpa/nameser.h>
+#endif
+
+#ifdef HAVE_SYS_SOCKIO_H
+#include <sys/sockio.h>
+#endif
+
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
+#include <net/if.h>
+
+#ifdef HAVE_SCHED_H
+#include <sched.h>
+#endif
+
+#ifdef HAVE_SETNS_H
+#include <setns.h>
+#endif
+
+#define HAVE_UDP
+
+#ifndef WANT_NONBLOCKING
+#define WANT_NONBLOCKING
+#endif
+#include "sys.h"
+
+#endif
+
+#include <erl_nif.h>
+
+#include "socket_dbg.h"
+#include "socket_int.h"
+#include "socket_util.h"
+
+
+/* All platforms fail on malloc errors. */
+#define FATAL_MALLOC
+
+
+#ifdef __WIN32__
+#define net_gethostname(__buf__, __bufSz__) gethostname((__buf__), (__bufSz__))
+#else
+#define net_gethostname(__buf__, __bufSz__) gethostname((__buf__), (__bufSz__))
+#endif // __WIN32__
+
+
+
+/* *** Misc macros and defines *** */
+
+#ifdef __WIN32__
+#define get_errno() WSAGetLastError()
+#else
+#define get_errno() errno
+#endif
+
+
+#define HOSTNAME_LEN 256
+#define SERVICE_LEN  256
+
+
+/* MAXHOSTNAMELEN could be 64 or 255 depending
+ * on the platform. Instead, use INET_MAXHOSTNAMELEN
+ * which is always 255 across all platforms
+ */
+#define NET_MAXHOSTNAMELEN 255
+
+
+/* =================================================================== *
+ *                                                                     *
+ *                        Various enif macros                          *
+ *                                                                     *
+ * =================================================================== */
+
+
+#ifdef HAVE_SOCKLEN_T
+#  define SOCKLEN_T socklen_t
+#else
+#  define SOCKLEN_T size_t
+#endif
+
+/* Debug stuff... */
+#define NET_NIF_DEBUG_DEFAULT FALSE
+
+#define NDBG( proto ) ESOCK_DBG_PRINTF( data.debug , proto )
+
+
+typedef struct {
+    BOOLEAN_T debug;
+} NetData;
+
+
+
+/* =================================================================== *
+ *                                                                     *
+ *                           Static data                               *
+ *                                                                     *
+ * =================================================================== */
+
+
+static NetData data;
+
+
+
+/* ----------------------------------------------------------------------
+ *  F o r w a r d s
+ * ----------------------------------------------------------------------
+ */
+
+/* THIS IS JUST TEMPORARY */
+extern char* erl_errno_id(int error);
+
+/* All the nif "callback" functions for the net API has
+ * the exact same API:
+ *
+ * nif_<funcname>(ErlNifEnv*         env,
+ *                int                argc,
+ *                const ERL_NIF_TERM argv[]);
+ *
+ * So, to simplify, use some macro magic to define those.
+ *
+ * These are the functions making up the "official" API.
+ */
+
+#define ENET_NIF_FUNCS                  \
+    ENET_NIF_FUNC_DEF(info);            \
+    ENET_NIF_FUNC_DEF(command);         \
+    ENET_NIF_FUNC_DEF(gethostname);     \
+    ENET_NIF_FUNC_DEF(getnameinfo);     \
+    ENET_NIF_FUNC_DEF(getaddrinfo);      \
+    ENET_NIF_FUNC_DEF(if_name2index);   \
+    ENET_NIF_FUNC_DEF(if_index2name);   \
+    ENET_NIF_FUNC_DEF(if_names);
+
+#define ENET_NIF_FUNC_DEF(F)                              \
+    static ERL_NIF_TERM nif_##F(ErlNifEnv*         env,    \
+                                int                argc,   \
+                                const ERL_NIF_TERM argv[]);
+ENET_NIF_FUNCS
+#undef ENET_NIF_FUNC_DEF
+
+
+/* And here comes the functions that does the actual work (for the most part) */
+static ERL_NIF_TERM ncommand(ErlNifEnv*   env,
+                             ERL_NIF_TERM cmd);
+static ERL_NIF_TERM ngethostname(ErlNifEnv* env);
+static ERL_NIF_TERM ngetnameinfo(ErlNifEnv*          env,
+                                 const ESockAddress* saP,
+                                 SOCKLEN_T           saLen,
+                                 int                 flags);
+static ERL_NIF_TERM ngetaddrinfo(ErlNifEnv* env,
+                                 char*      host,
+                                 char*      serv);
+static ERL_NIF_TERM nif_name2index(ErlNifEnv* env,
+                                   char*      ifn);
+static ERL_NIF_TERM nif_index2name(ErlNifEnv*   env,
+                                   unsigned int id);
+static ERL_NIF_TERM nif_names(ErlNifEnv* env);
+static unsigned int nif_names_length(struct if_nameindex* p);
+
+/*
+static void net_dtor(ErlNifEnv* env, void* obj);
+static void net_stop(ErlNifEnv* env,
+                     void*      obj,
+                     int        fd,
+                     int        is_direct_call);
+static void net_down(ErlNifEnv*           env,
+                     void*                obj,
+                     const ErlNifPid*     pid,
+                     const ErlNifMonitor* mon);
+*/
+
+static BOOLEAN_T decode_nameinfo_flags(ErlNifEnv*         env,
+                                       const ERL_NIF_TERM eflags,
+                                       int*               flags);
+static BOOLEAN_T decode_nameinfo_flags_list(ErlNifEnv*         env,
+                                            const ERL_NIF_TERM eflags,
+                                            int*               flags);
+static
+BOOLEAN_T decode_addrinfo_string(ErlNifEnv*         env,
+                                 const ERL_NIF_TERM eString,
+                                 char**             stringP);
+static ERL_NIF_TERM decode_bool(ErlNifEnv*   env,
+                                ERL_NIF_TERM eBool,
+                                BOOLEAN_T*   bool);
+static ERL_NIF_TERM encode_address_infos(ErlNifEnv*       env,
+                                         struct addrinfo* addrInfo);
+static ERL_NIF_TERM encode_address_info(ErlNifEnv*       env,
+                                        struct addrinfo* addrInfoP);
+static unsigned int address_info_length(struct addrinfo* addrInfoP);
+
+static ERL_NIF_TERM encode_address_info_family(ErlNifEnv* env,
+                                         int        family);
+static ERL_NIF_TERM encode_address_info_type(ErlNifEnv* env,
+                                       int        socktype);
+static ERL_NIF_TERM encode_address_info_proto(ErlNifEnv* env,
+                                        int        proto);
+
+static char* make_address_info(ErlNifEnv*    env,
+                               ERL_NIF_TERM  fam,
+                               ERL_NIF_TERM  sockType,
+                               ERL_NIF_TERM  proto,
+                               ERL_NIF_TERM  addr,
+                               ERL_NIF_TERM* ai);
+
+static BOOLEAN_T extract_debug(ErlNifEnv*   env,
+                               ERL_NIF_TERM map);
+static int on_load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info);
+
+
+#if HAVE_IN6
+#  if ! defined(HAVE_IN6ADDR_ANY) || ! HAVE_IN6ADDR_ANY
+#    if HAVE_DECL_IN6ADDR_ANY_INIT
+static const struct in6_addr in6addr_any = { { IN6ADDR_ANY_INIT } };
+#    else
+static const struct in6_addr in6addr_any =
+    { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } };
+#    endif /* HAVE_IN6ADDR_ANY_INIT */
+#  endif /* ! HAVE_DECL_IN6ADDR_ANY */
+
+#  if ! defined(HAVE_IN6ADDR_LOOPBACK) || ! HAVE_IN6ADDR_LOOPBACK
+#    if HAVE_DECL_IN6ADDR_LOOPBACK_INIT
+static const struct in6_addr in6addr_loopback =
+    { { IN6ADDR_LOOPBACK_INIT } };
+#    else
+static const struct in6_addr in6addr_loopback =
+    { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 } } };
+#    endif /* HAVE_IN6ADDR_LOOPBACk_INIT */
+#  endif /* ! HAVE_DECL_IN6ADDR_LOOPBACK */
+#endif /* HAVE_IN6 */
+
+
+
+/* *** Local atoms *** */
+
+#define LOCAL_ATOMS                             \
+    LOCAL_ATOM_DECL(address_info);              \
+    LOCAL_ATOM_DECL(debug);                     \
+    LOCAL_ATOM_DECL(host);                      \
+    LOCAL_ATOM_DECL(idn);                       \
+    LOCAL_ATOM_DECL(idna_allow_unassigned);     \
+    LOCAL_ATOM_DECL(idna_use_std3_ascii_rules); \
+    LOCAL_ATOM_DECL(namereqd);                  \
+    LOCAL_ATOM_DECL(name_info);                 \
+    LOCAL_ATOM_DECL(nofqdn);                    \
+    LOCAL_ATOM_DECL(numerichost);               \
+    LOCAL_ATOM_DECL(numericserv);               \
+    LOCAL_ATOM_DECL(service);
+
+#define LOCAL_ERROR_REASON_ATOMS               \
+    LOCAL_ATOM_DECL(eaddrfamily);              \
+    LOCAL_ATOM_DECL(ebadflags);                \
+    LOCAL_ATOM_DECL(efail);                    \
+    LOCAL_ATOM_DECL(efamily);                  \
+    LOCAL_ATOM_DECL(efault);                   \
+    LOCAL_ATOM_DECL(emem);                     \
+    LOCAL_ATOM_DECL(enametoolong);             \
+    LOCAL_ATOM_DECL(enodata);                  \
+    LOCAL_ATOM_DECL(enoname);                  \
+    LOCAL_ATOM_DECL(enxio);                    \
+    LOCAL_ATOM_DECL(eoverflow);                \
+    LOCAL_ATOM_DECL(eservice);                 \
+    LOCAL_ATOM_DECL(esocktype);                \
+    LOCAL_ATOM_DECL(esystem);
+
+#define LOCAL_ATOM_DECL(A) static ERL_NIF_TERM atom_##A
+LOCAL_ATOMS
+LOCAL_ERROR_REASON_ATOMS
+#undef LOCAL_ATOM_DECL
+
+
+/* *** net *** */
+static ErlNifResourceType*    net;
+static ErlNifResourceTypeInit netInit = {
+    NULL, // net_dtor,
+    NULL, // net_stop,
+    NULL  // (ErlNifResourceDown*) net_down
+};
+
+
+
+/* ----------------------------------------------------------------------
+ *  N I F   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ *
+ * Utility and admin functions:
+ * ----------------------------
+ * nif_info/0
+ * nif_command/1
+ *
+ * The "proper" net functions:
+ * ------------------------------
+ * nif_gethostname/0
+ * nif_getnameinfo/2
+ * nif_getaddrinfo/3
+ * nif_if_name2index/1
+ * nif_if_index2name/1
+ * nif_if_names/0
+ *
+ */
+
+
+/* ----------------------------------------------------------------------
+ * nif_info
+ *
+ * Description:
+ * This is currently just a placeholder...
+ */
+static
+ERL_NIF_TERM nif_info(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM info, tmp;
+
+    NDBG( ("NET", "info -> entry\r\n") );
+
+    tmp  = enif_make_new_map(env);
+    if (!enif_make_map_put(env, tmp, atom_debug, BOOL2ATOM(data.debug), &info))
+        info = tmp;
+
+    NDBG( ("NET", "info -> done: %T\r\n", info) );
+
+    return info;
+#endif
+}
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_command
+ *
+ * Description:
+ * This is a general purpose utility function.
+ *
+ * Arguments:
+ * Command - This is a general purpose command, of any type.
+ *           Currently, the only supported command is:
+ *
+ *                  {debug, boolean()}
+ */
+static
+ERL_NIF_TERM nif_command(ErlNifEnv*         env,
+                         int                argc,
+                         const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM ecmd, result;
+
+    NDBG( ("NET", "command -> entry (%d)\r\n", argc) );
+
+    if (argc != 1)
+        return enif_make_badarg(env);
+
+    ecmd = argv[0];
+
+    NDBG( ("NET", "command -> ecmd: %T\r\n", ecmd) );
+
+    result = ncommand(env, ecmd);
+
+    NDBG( ("NET", "command -> result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+/*
+ * The command can, in principle, be anything, though currently we only
+ * support a debug command.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ncommand(ErlNifEnv*   env,
+                      ERL_NIF_TERM cmd)
+{
+    const ERL_NIF_TERM* t;
+    int                 tsz;
+
+    if (IS_TUPLE(env, cmd)) {
+        /* Could be the debug tuple */
+        if (!GET_TUPLE(env, cmd, &tsz, &t))
+            return esock_make_error(env, esock_atom_einval);
+
+        if (tsz != 2)
+            return esock_make_error(env, esock_atom_einval);
+
+        /* First element should be the atom 'debug' */
+        if (COMPARE(t[0], atom_debug) != 0)
+            return esock_make_error(env, esock_atom_einval);
+
+        return decode_bool(env, t[1], &data.debug);
+
+    } else {
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_gethostname
+ *
+ * Description:
+ * Access the hostname of the current processor.
+ *
+ */
+static
+ERL_NIF_TERM nif_gethostname(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM result;
+    
+    NDBG( ("NET", "nif_gethostname -> entry (%d)\r\n", argc) );
+
+    if (argc != 0)
+        return enif_make_badarg(env);
+
+    result = ngethostname(env);
+
+    NDBG( ("NET", "nif_gethostname -> done when result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ngethostname(ErlNifEnv* env)
+{
+    ERL_NIF_TERM result;
+    char         buf[NET_MAXHOSTNAMELEN + 1];
+    int          res;
+
+    res = net_gethostname(buf, sizeof(buf));
+
+    NDBG( ("NET", "ngethostname -> gethostname res: %d\r\n", res) );
+
+    switch (res) {
+    case 0:
+        result = esock_make_ok2(env, MKS(env, buf));
+        break;
+
+    case EFAULT:
+        result = esock_make_error(env, atom_efault);
+        break;
+
+    case EINVAL:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+
+    case ENAMETOOLONG:
+        result = esock_make_error(env, atom_enametoolong);
+        break;
+
+    default:
+        result = esock_make_error(env, MKI(env, res));
+        break;
+    }
+
+    return result;
+}
+#endif
+
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_getnameinfo
+ *
+ * Description:
+ * Address-to-name translation in protocol-independent manner.
+ *
+ * Arguments:
+ * SockAddr - Socket Address (address and port)
+ * Flags    - The flags argument modifies the behavior of getnameinfo().
+ */
+
+static
+ERL_NIF_TERM nif_getnameinfo(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM result;
+    ERL_NIF_TERM eSockAddr, eFlags;
+    int          flags = 0; // Just in case...
+    ESockAddress sa;
+    SOCKLEN_T    saLen = 0; // Just in case...
+    char*        xres;
+
+    NDBG( ("NET", "nif_getnameinfo -> entry (%d)\r\n", argc) );
+
+    if (argc != 2)
+        return enif_make_badarg(env);
+    eSockAddr = argv[0];
+    eFlags    = argv[1];
+
+    NDBG( ("NET",
+           "nif_getnameinfo -> "
+           "\r\n   SockAddr: %T"
+           "\r\n   Flags:    %T"
+           "\r\n", eSockAddr, eFlags) );
+
+    if ((xres = esock_decode_sockaddr(env, eSockAddr, &sa, &saLen)) != NULL) {
+        NDBG( ("NET", "nif_getnameinfo -> failed decode sockaddr: %s\r\n", xres) );
+        return esock_make_error_str(env, xres);
+    }
+
+    NDBG( ("NET", "nif_getnameinfo -> (try) decode flags\r\n") );
+
+    if (!decode_nameinfo_flags(env, eFlags, &flags))
+        return enif_make_badarg(env);
+
+    result = ngetnameinfo(env, &sa, saLen, flags);
+
+    NDBG( ("NET",
+           "nif_getnameinfo -> done when result: "
+           "\r\n   %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+/* Given the provided sock(et) address (and flags), retreive the host and
+ * service info.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ngetnameinfo(ErlNifEnv*          env,
+                          const ESockAddress* saP,
+                          SOCKLEN_T           saLen,
+                          int                 flags)
+{
+    ERL_NIF_TERM result;
+    char         host[HOSTNAME_LEN];
+    SOCKLEN_T    hostLen = sizeof(host);
+    char         serv[SERVICE_LEN];
+    SOCKLEN_T    servLen = sizeof(serv);
+
+    int res = getnameinfo((struct sockaddr*) saP, saLen,
+                          host, hostLen,
+                          serv, servLen,
+                          flags);
+
+    NDBG( ("NET", "ngetnameinfo -> res: %d\r\n", res) );
+
+    switch (res) {
+    case 0:
+        {
+            ERL_NIF_TERM keys[] = {atom_host,      atom_service};
+            ERL_NIF_TERM vals[] = {MKS(env, host), MKS(env, serv)};
+            ERL_NIF_TERM info;
+            unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+            unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+            ESOCK_ASSERT( (numKeys == numVals) );
+
+            if (!MKMA(env, keys, vals, numKeys, &info))
+                return enif_make_badarg(env);
+
+            result = esock_make_ok2(env, info);
+        }
+        break;
+
+#if defined(EAI_AGAIN)
+    case EAI_AGAIN:
+        result = esock_make_error(env, esock_atom_eagain);
+        break;
+#endif
+
+#if defined(EAI_BADFLAGS)
+    case EAI_BADFLAGS:
+        result = esock_make_error(env, atom_ebadflags);
+        break;
+#endif
+
+#if defined(EAI_FAIL)
+    case EAI_FAIL:
+        result = esock_make_error(env, atom_efail);
+        break;
+#endif
+
+#if defined(EAI_FAMILY)
+    case EAI_FAMILY:
+        result = esock_make_error(env, atom_efamily);
+        break;
+#endif
+
+#if defined(EAI_MEMORY)
+    case EAI_MEMORY:
+        result = esock_make_error(env, atom_emem);
+        break;
+#endif
+
+#if defined(EAI_NONAME)
+    case EAI_NONAME:
+        result = esock_make_error(env, atom_enoname);
+        break;
+#endif
+
+#if defined(EAI_OVERFLOW)
+    case EAI_OVERFLOW:
+        result = esock_make_error(env, atom_eoverflow);
+        break;
+#endif
+
+#if defined(EAI_SYSTEM)
+    case EAI_SYSTEM:
+        result = esock_make_error_errno(env, get_errno());
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_getaddrinfo
+ *
+ * Description:
+ * Network address and service translation.
+ *
+ * Arguments:
+ * Host    - Host name (either a string or the atom undefined)
+ * Service - Service name (either a string or the atom undefined)
+ * Hints   - Hints for the lookup (address info record) (currently *ignored*)
+ */
+
+static
+ERL_NIF_TERM nif_getaddrinfo(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM     result, eHostName, eServName; //, eHints;
+    char*            hostName;
+    char*            servName;
+    // struct addrinfo* hints;
+
+    NDBG( ("NET", "nif_getaddrinfo -> entry (%d)\r\n", argc) );
+
+    if (argc != 3) {
+        return enif_make_badarg(env);
+    }
+    eHostName = argv[0];
+    eServName = argv[1];
+    // eHints    = argv[2];
+
+    NDBG( ("NET",
+           "nif_getaddrinfo -> "
+           "\r\n   ehost:    %T"
+           "\r\n   eservice: %T"
+           "\r\n   ehints:   %T"
+           "\r\n", argv[0], argv[1], argv[2]) );
+
+    if (!decode_addrinfo_string(env, eHostName, &hostName))
+        return enif_make_badarg(env);
+
+    if (!decode_addrinfo_string(env, eServName, &servName))
+        return enif_make_badarg(env);
+
+    /*
+    if (decode_addrinfo_hints(env, eHints, &hints))
+        return enif_make_badarg(env);
+    */
+
+    if ((hostName == NULL) && (servName == NULL))
+        return enif_make_badarg(env);
+
+    result = ngetaddrinfo(env, hostName, servName);
+
+    if (hostName != NULL)
+        FREE(hostName);
+
+    if (servName != NULL)
+        FREE(servName);
+
+    /*
+    if (hints != NULL)
+        FREE(hints);
+    */
+
+    NDBG( ("NET",
+           "nif_getaddrinfo -> done when result: "
+           "\r\n   %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ngetaddrinfo(ErlNifEnv* env,
+                          char*      host,
+                          char*      serv)
+{
+    ERL_NIF_TERM     result;
+    struct addrinfo* addrInfoP;
+    int              res;
+
+    NDBG( ("NET", "ngetaddrinfo -> entry with"
+           "\r\n   host: %s"
+           "\r\n   serv: %s"
+           "\r\n",
+           ((host == NULL) ? "NULL" : host),
+           ((serv == NULL) ? "NULL" : serv)) );
+    
+    res = getaddrinfo(host, serv, NULL, &addrInfoP);
+
+    NDBG( ("NET", "ngetaddrinfo -> res: %d\r\n", res) );
+    
+    switch (res) {
+    case 0:
+        {
+            ERL_NIF_TERM addrInfo = encode_address_infos(env, addrInfoP);
+            freeaddrinfo(addrInfoP);
+            result = esock_make_ok2(env, addrInfo);
+        }
+        break;
+
+#if defined(EAI_ADDRFAMILY)
+    case EAI_ADDRFAMILY:
+        result = esock_make_error(env, atom_eaddrfamily);
+        break;
+#endif
+
+#if defined(EAI_AGAIN)
+    case EAI_AGAIN:
+        result = esock_make_error(env, esock_atom_eagain);
+        break;
+#endif
+
+#if defined(EAI_BADFLAGS)
+    case EAI_BADFLAGS:
+        result = esock_make_error(env, atom_ebadflags);
+        break;
+#endif
+
+#if defined(EAI_FAIL)
+    case EAI_FAIL:
+        result = esock_make_error(env, atom_efail);
+        break;
+#endif
+
+#if defined(EAI_FAMILY)
+    case EAI_FAMILY:
+        result = esock_make_error(env, atom_efamily);
+        break;
+#endif
+
+#if defined(EAI_MEMORY)
+    case EAI_MEMORY:
+        result = esock_make_error(env, atom_emem);
+        break;
+#endif
+
+#if defined(EAI_NODATA)
+    case EAI_NODATA:
+        result = esock_make_error(env, atom_enodata);
+        break;
+#endif
+
+#if defined(EAI_NONAME)
+    case EAI_NONAME:
+        result = esock_make_error(env, atom_enoname);
+        break;
+#endif
+
+#if defined(EAI_SERVICE)
+    case EAI_SERVICE:
+        result = esock_make_error(env, atom_eservice);
+        break;
+#endif
+
+#if defined(EAI_SOCKTYPE)
+    case EAI_SOCKTYPE:
+        result = esock_make_error(env, atom_esocktype);
+        break;
+#endif
+
+#if defined(EAI_SYSTEM)
+    case EAI_SYSTEM:
+        result = esock_make_error(env, atom_esystem);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_if_name2index
+ *
+ * Description:
+ * Perform a Interface Name to Interface Index translation.
+ *
+ * Arguments:
+ * Ifn - Interface name to be translated.
+ */
+
+static
+ERL_NIF_TERM nif_if_name2index(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM eifn, result;
+    char         ifn[IF_NAMESIZE+1];
+
+    NDBG( ("NET", "nif_if_name2index -> entry (%d)\r\n", argc) );
+
+    if (argc != 1) {
+        return enif_make_badarg(env);
+    }
+    eifn = argv[0];
+
+    NDBG( ("NET",
+           "nif_if_name2index -> "
+           "\r\n   Ifn: %T"
+           "\r\n", argv[0]) );
+
+    if (0 >= GET_STR(env, eifn, ifn, sizeof(ifn)))
+        return esock_make_error(env, esock_atom_einval);
+
+    result = nif_name2index(env, ifn);
+
+    NDBG( ("NET", "nif_if_name2index -> done when result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nif_name2index(ErlNifEnv* env,
+                            char*      ifn)
+{
+    unsigned int idx;
+
+    NDBG( ("NET", "nif_name2index -> entry with ifn: %s\r\n", ifn) );
+
+    idx = if_nametoindex(ifn);
+
+    NDBG( ("NET", "nif_name2index -> idx: %d\r\n", idx) );
+
+    if (idx == 0) {
+        int save_errno = get_errno();
+        NDBG( ("NET", "nif_name2index -> failed: %d\r\n", save_errno) );
+        return esock_make_error_errno(env, save_errno);
+    } else {
+         return esock_make_ok2(env, MKI(env, idx));
+    }
+
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_if_index2name
+ *
+ * Description:
+ * Perform a Interface Index to Interface Name translation.
+ *
+ * Arguments:
+ * Idx - Interface index to be translated.
+ */
+
+static
+ERL_NIF_TERM nif_if_index2name(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM result;
+    unsigned int idx;
+
+    NDBG( ("NET", "nif_if_index2name -> entry (%d)\r\n", argc) );
+
+    if ((argc != 1) ||
+        !GET_UINT(env, argv[0], &idx)) {
+        return enif_make_badarg(env);
+    }
+
+    NDBG( ("NET", "nif_index2name -> "
+           "\r\n   Idx: %T"
+           "\r\n", argv[0]) );
+
+    result = nif_index2name(env, idx);
+
+    NDBG( ("NET", "nif_if_index2name -> done when result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nif_index2name(ErlNifEnv*   env,
+                            unsigned int idx)
+{
+    ERL_NIF_TERM result;
+    char*        ifn = MALLOC(IF_NAMESIZE+1);
+
+    if (ifn == NULL)
+        return enif_make_badarg(env); // PLACEHOLDER
+
+    if (NULL != if_indextoname(idx, ifn)) {
+        result = esock_make_ok2(env, MKS(env, ifn));
+    } else {
+        result = esock_make_error(env, atom_enxio);
+    }
+
+    FREE(ifn);
+
+    return result;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_if_names
+ *
+ * Description:
+ * Get network interface names and indexes.
+ *
+ */
+
+static
+ERL_NIF_TERM nif_if_names(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM result;
+
+    NDBG( ("NET", "nif_if_names -> entry (%d)\r\n", argc) );
+
+    if (argc != 0) {
+        return enif_make_badarg(env);
+    }
+
+    result = nif_names(env);
+
+    NDBG( ("NET", "nif_if_names -> done when result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nif_names(ErlNifEnv* env)
+{
+    ERL_NIF_TERM         result;
+    struct if_nameindex* ifs = if_nameindex();
+
+    NDBG( ("NET", "nif_names -> ifs: 0x%lX\r\n", ifs) );
+
+    if (ifs == NULL) {
+        result = esock_make_error_errno(env, get_errno());
+    } else {
+        /*
+         * We got some interfaces:
+         * 1) Calculate how many - the only way is to iterate through the list
+         *    until its end (which is indicated by an entry with index = zero
+         *    and if_name = NULL).
+         * 2) Allocate an ERL_NIF_TERM array of the calculated length.
+         * 3) Iterate through the array of interfaces and for each create
+         *    a two tuple: {Idx, If}
+         *
+         * Or shall we instead build a list in reverse order and then when
+         * its done, reverse that? Check
+         */
+        unsigned int len = nif_names_length(ifs);
+
+        NDBG( ("NET", "nif_names -> len: %d\r\n", len) );
+
+        if (len > 0) {
+            ERL_NIF_TERM* array = MALLOC(len * sizeof(ERL_NIF_TERM));
+            unsigned int  i;
+
+            for (i = 0; i < len; i++) {
+                array[i] = MKT2(env,
+                                MKI(env, ifs[i].if_index),
+                                MKS(env, ifs[i].if_name));
+            }
+
+            result = esock_make_ok2(env, MKLA(env, array, len));
+            FREE(array);
+        } else {
+            result = esock_make_ok2(env, enif_make_list(env, 0));
+        }
+    }
+
+    if (ifs != NULL)
+        if_freenameindex(ifs);
+
+    return result;
+}
+
+
+static
+unsigned int nif_names_length(struct if_nameindex* p)
+{
+    unsigned int len = 0;
+    BOOLEAN_T    done =  FALSE;
+
+    while (!done) {
+
+        NDBG( ("NET", "nif_names_length -> %d: "
+               "\r\n   if_index: %d"
+               "\r\n   if_name:  0x%lX"
+               "\r\n", len, p[len].if_index, p[len].if_name) );
+
+        if ((p[len].if_index == 0) && (p[len].if_name == NULL))
+            done = TRUE;
+        else
+            len++;
+    }
+
+    return len;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  U t i l i t y   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* The erlang format for a set of flags is a list of atoms.
+ * A special case is when there is no flags, which is
+ * represented by the atom undefined.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T decode_nameinfo_flags(ErlNifEnv*         env,
+                                const ERL_NIF_TERM eflags,
+                                int*               flags)
+{
+    BOOLEAN_T result;
+
+    if (IS_ATOM(env, eflags)) {
+        NDBG( ("NET", "decode_nameinfo_flags -> is atom (%T)\r\n", eflags) );
+        if (COMPARE(eflags, esock_atom_undefined) == 0) {
+            *flags = 0;
+            result = TRUE;
+        } else {
+            result = FALSE;
+        }
+    } else if (IS_LIST(env, eflags)) {
+        NDBG( ("NET", "decode_nameinfo_flags -> is list\r\n") );
+        result = decode_nameinfo_flags_list(env, eflags, flags);
+    } else {
+        result = FALSE;
+    }
+
+    NDBG( ("NET", "decode_nameinfo_flags -> result: %s\r\n", B2S(result)) );
+
+    return result;
+}
+
+
+
+static
+BOOLEAN_T decode_nameinfo_flags_list(ErlNifEnv*         env,
+                                     const ERL_NIF_TERM eflags,
+                                     int*               flags)
+{
+    ERL_NIF_TERM elem, tail, list = eflags;
+    int          tmp = 0;
+    BOOLEAN_T    done = FALSE;
+
+    while (!done) {
+        if (GET_LIST_ELEM(env, list, &elem, &tail)) {
+            if (COMPARE(elem, atom_namereqd) == 0) {
+                tmp |= NI_NAMEREQD;
+            } else if (COMPARE(elem, esock_atom_dgram) == 0) {
+                tmp |= NI_DGRAM;
+            } else if (COMPARE(elem, atom_nofqdn) == 0) {
+                tmp |= NI_NOFQDN;
+            } else if (COMPARE(elem, atom_numerichost) == 0) {
+                tmp |= NI_NUMERICHOST;
+            } else if (COMPARE(elem, atom_numericserv) == 0) {
+                tmp |= NI_NUMERICSERV;
+
+                /* Starting with glibc 2.3.4: */
+
+#if defined(NI_IDN)
+            } else if (COMPARE(elem, atom_idn) == 0) {
+                tmp |= NI_IDN;
+#endif
+
+#if defined(NI_IDN_ALLOW_UNASSIGNED)
+            } else if (COMPARE(elem, atom_idna_allow_unassigned) == 0) {
+                tmp |= NI_IDN_ALLOW_UNASSIGNED;
+#endif
+
+#if defined(NI_IDN_USE_STD3_ASCII_RULES)
+            } else if (COMPARE(elem, atom_idna_use_std3_ascii_rules) == 0) {
+                tmp |= NI_IDN_USE_STD3_ASCII_RULES;
+#endif
+
+            } else {
+                return FALSE;
+            }
+
+            list = tail;
+
+        } else {
+            done = TRUE;
+        }
+    }
+
+    *flags = tmp;
+
+    return TRUE;
+}
+
+
+
+/* Decode the address info string (hostname or service name)
+ * The string is either the atom undefined or an actual string.
+ */
+static
+BOOLEAN_T decode_addrinfo_string(ErlNifEnv*         env,
+                                 const ERL_NIF_TERM eString,
+                                 char**             stringP)
+{
+    BOOLEAN_T result;
+
+    if (IS_ATOM(env, eString)) {
+
+        if (COMPARE(eString, esock_atom_undefined) == 0) {
+            *stringP = NULL;
+            result   = TRUE;
+        } else {
+            *stringP = NULL;
+            result   = FALSE;
+        }
+
+    } else {
+
+        result = esock_decode_string(env, eString, stringP);
+
+    }
+
+    return result;
+
+}
+
+
+
+static
+ERL_NIF_TERM decode_bool(ErlNifEnv*   env,
+                         ERL_NIF_TERM eBool,
+                         BOOLEAN_T*   bool)
+{
+    if (COMPARE(eBool, esock_atom_true) == 0) {
+        *bool = TRUE;
+        return esock_atom_ok;
+    } else if (COMPARE(eBool, esock_atom_false) == 0) {
+        *bool = FALSE;
+        return esock_atom_ok;
+    } else {
+        return esock_make_error(env, esock_atom_einval);
+    }
+}
+
+
+
+/* Encode the address info
+ * The address info is a linked list och address info, which
+ * will result in the result being a list of zero or more length.
+ */
+static
+ERL_NIF_TERM encode_address_infos(ErlNifEnv*       env,
+                                  struct addrinfo* addrInfo)
+{
+    ERL_NIF_TERM result;
+    unsigned int len = address_info_length(addrInfo);
+
+    NDBG( ("NET", "encode_address_infos -> len: %d\r\n", len) );
+
+    if (len > 0) {
+        ERL_NIF_TERM*    array = MALLOC(len * sizeof(ERL_NIF_TERM));
+        unsigned int     i     = 0;
+        struct addrinfo* p     = addrInfo;
+
+        while (i < len) {
+            array[i] = encode_address_info(env, p);
+            p = p->ai_next;
+            i++;
+        }
+
+        result = MKLA(env, array, len);
+        FREE(array);
+    } else {
+        result = MKEL(env);
+    }
+
+    NDBG( ("NET", "encode_address_infos -> result: "
+           "\r\n   %T\r\n", result) );
+
+    return result;
+}
+
+
+
+/* Calculate the length of the adress info linked list
+ * The list is NULL-terminated, so the only way is to
+ * iterate through the list until we find next = NULL.
+ */
+static
+unsigned int address_info_length(struct addrinfo* addrInfoP)
+{
+    unsigned int     len = 1;
+    struct addrinfo* tmp;
+    BOOLEAN_T        done = FALSE;
+
+    tmp = addrInfoP;
+
+    while (!done) {
+        if (tmp->ai_next != NULL) {
+            len++;
+            tmp = tmp->ai_next;
+        } else {
+            done = TRUE;
+        }
+    }
+
+    return len;
+}
+
+
+
+/* Create one (erlang) instance of the address info record
+ * Should we have address info as a record or as a map?
+ *
+ * {address_info, Fam, Type, Proto, Addr}
+ */
+static
+ERL_NIF_TERM encode_address_info(ErlNifEnv*       env,
+                                 struct addrinfo* addrInfoP)
+{
+    ERL_NIF_TERM fam, type, proto, addr, addrInfo;
+
+    fam   = encode_address_info_family(env, addrInfoP->ai_family);
+    type  = encode_address_info_type(env,   addrInfoP->ai_socktype);
+    proto = encode_address_info_proto(env,  addrInfoP->ai_protocol);
+    esock_encode_sockaddr(env,
+                          (ESockAddress*) addrInfoP->ai_addr,
+                          addrInfoP->ai_addrlen,
+                          &addr);
+    
+    if (make_address_info(env, fam, type, proto, addr, &addrInfo) == NULL)
+        return addrInfo;
+    else
+        return esock_atom_undefined; // We should to better...
+
+}
+
+
+/* Convert an "native" family to an erlang family (=domain).
+ * Note that this is not currently exhaustive, but only supports
+ * inet and inet6. Other values will be returned as is, that is
+ * in the form of an integer.
+ */
+static
+ERL_NIF_TERM encode_address_info_family(ErlNifEnv* env,
+                                        int        family)
+{
+    ERL_NIF_TERM efam;
+
+    if (NULL != esock_encode_domain(env, family, &efam))
+        efam = MKI(env, family);
+
+    return efam;
+}
+
+
+
+/* Convert an "native" socket type to an erlang socket type.
+ * Note that this is not currently exhaustive, but only supports
+ * stream and dgram. Other values will be returned as is, that is
+ * in the form of an integer.
+ */
+static
+ERL_NIF_TERM encode_address_info_type(ErlNifEnv* env,
+                                      int        socktype)
+{
+    ERL_NIF_TERM etype;
+
+    if (NULL != esock_encode_type(env, socktype, &etype))
+        etype = MKI(env, socktype);
+
+    return etype;
+}
+
+
+
+/* Convert an "native" protocol to an erlang protocol.
+ * Note that this is not currently exhaustive, but only supports
+ * tcp and udp. Other values will be returned as is, that is
+ * in the form of an integer.
+ */
+static
+ERL_NIF_TERM encode_address_info_proto(ErlNifEnv* env,
+                                       int        proto)
+{
+    ERL_NIF_TERM eproto;
+
+    if (NULL != esock_encode_protocol(env, proto, &eproto))
+        eproto = MKI(env, proto);
+
+    return eproto;
+}
+
+
+
+static
+char* make_address_info(ErlNifEnv*    env,
+                        ERL_NIF_TERM  fam,
+                        ERL_NIF_TERM  sockType,
+                        ERL_NIF_TERM  proto,
+                        ERL_NIF_TERM  addr,
+                        ERL_NIF_TERM* ai)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_family,
+                           esock_atom_type,
+                           esock_atom_protocol,
+                           esock_atom_addr};
+    ERL_NIF_TERM vals[] = {fam, sockType, proto, addr};
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, ai)) {
+        *ai = esock_atom_undefined;
+        return ESOCK_STR_EINVAL;
+    } else {
+        return NULL;
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  C a l l b a c k   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* =========================================================================
+ * net_dtor - Callback function for resource destructor
+ *
+ */
+/*
+static
+void net_dtor(ErlNifEnv* env, void* obj)
+{
+}
+*/
+
+
+/* =========================================================================
+ * net_stop - Callback function for resource stop
+ *
+ */
+/*
+static
+void net_stop(ErlNifEnv* env, void* obj, int fd, int is_direct_call)
+{
+}
+*/
+
+
+
+
+/* =========================================================================
+ * net_down - Callback function for resource down (monitored processes)
+ *
+ */
+/*
+static
+void net_down(ErlNifEnv*           env,
+              void*                obj,
+              const ErlNifPid*     pid,
+              const ErlNifMonitor* mon)
+{
+}
+*/
+
+
+
+/* ----------------------------------------------------------------------
+ *  L o a d / u n l o a d / u p g r a d e   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+static
+ErlNifFunc net_funcs[] =
+{
+    // Some utility functions
+    {"nif_info",      0, nif_info,      0},
+    {"nif_command",   1, nif_command,   0}, // Shall we let this be dirty?
+
+    /* get/set hostname */
+    {"nif_gethostname",         0, nif_gethostname,   0},
+
+    /* address and name translation in protocol-independent manner */
+    {"nif_getnameinfo",         2, nif_getnameinfo,   0},
+    {"nif_getaddrinfo",         3, nif_getaddrinfo,   0},
+
+    /* Network interface (name and/or index) functions */
+    {"nif_if_name2index",       1, nif_if_name2index, 0},
+    {"nif_if_index2name",       1, nif_if_index2name, 0},
+    {"nif_if_names",            0, nif_if_names,      0}
+};
+
+
+#if !defined(__WIN32__)
+static
+BOOLEAN_T extract_debug(ErlNifEnv*   env,
+                        ERL_NIF_TERM map)
+{
+    /*
+     * We need to do this here since the "proper" atom has not been
+     * created when this function is called.
+     */
+    ERL_NIF_TERM debug = MKA(env, "debug");
+    
+    return esock_extract_bool_from_map(env, map, debug, NET_NIF_DEBUG_DEFAULT);
+}
+#endif
+
+
+/* =======================================================================
+ * load_info - A map of misc info (e.g global debug)
+ */
+
+static
+int on_load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info)
+{
+#if !defined(__WIN32__)    
+    // We should make it possible to use load_info to get default values
+    data.debug = extract_debug(env, load_info);
+
+    NDBG( ("NET", "on_load -> entry\r\n") );
+#endif
+
+#define LOCAL_ATOM_DECL(A) atom_##A = MKA(env, #A)
+LOCAL_ATOMS
+LOCAL_ERROR_REASON_ATOMS
+#undef LOCAL_ATOM_DECL
+
+    // For storing "global" things...
+    // data.env       = enif_alloc_env(); // We should really check
+    // data.version   = MKA(env, ERTS_VERSION);
+    // data.buildDate = MKA(env, ERTS_BUILD_DATE);
+
+    net = enif_open_resource_type_x(env,
+                                    "net",
+                                    &netInit,
+                                    ERL_NIF_RT_CREATE,
+                                    NULL);
+
+#if !defined(__WIN32__)    
+    NDBG( ("NET", "on_load -> done\r\n") );
+#endif
+
+    return !net;
+}
+
+ERL_NIF_INIT(prim_net, net_funcs, on_load, NULL, NULL, NULL)
diff --git a/erts/emulator/nifs/common/socket_dbg.c b/erts/emulator/nifs/common/socket_dbg.c
new file mode 100644
index 0000000000..0005575017
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_dbg.c
@@ -0,0 +1,97 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Debug functions for the socket and net NIF(s).
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <time.h>
+
+#include <erl_nif.h>
+#include "socket_util.h"
+#include "socket_dbg.h"
+
+#define TSELF()            enif_thread_self()
+#define TNAME(__T__)       enif_thread_name( __T__ )
+#define TSNAME()           TNAME(TSELF())
+
+FILE* esock_dbgout = NULL;
+
+extern
+void esock_dbg_init(char* filename)
+{
+  if (filename != NULL) {
+    if (strcmp(filename, ESOCK_DBGOUT_DEFAULT) == 0) {
+        esock_dbgout = stdout;
+    } else if (strcmp(filename, ESOCK_DBGOUT_UNIQUE) == 0) {
+        char template[] = "/tmp/esock-dbg-XXXXXX";
+        esock_dbgout = fdopen(mkstemp(template), "w+");
+    } else {
+        esock_dbgout = fopen(filename, "w+");
+    }
+  } else {
+    char template[] = "/tmp/esock-dbg-XXXXXX";
+    esock_dbgout = fdopen(mkstemp(template), "w+");
+  }
+}
+
+
+
+/*
+ * Print a debug format string *with* both a timestamp and the
+ * the name of the *current* thread.
+ */
+extern
+void esock_dbg_printf( const char* prefix, const char* format, ... )
+{
+  va_list         args;
+  char            f[512 + strlen(format)]; // This has to suffice...
+  char            stamp[30];
+  int             res;
+
+  /*
+   * We should really include self in the printout,
+   * so we can se which process are executing the code.
+   * But then I must change the API....something for later.
+   */
+
+  if (esock_timestamp(stamp, sizeof(stamp))) {
+      res = enif_snprintf(f, sizeof(f), "%s [%s] [%s] %s",
+                          prefix, stamp, TSNAME(), format);
+  } else {
+      res = enif_snprintf(f, sizeof(f), "%s [%s] %s",
+                          prefix, TSNAME(), format);
+  }
+  
+  if (res > 0) {
+      va_start (args, format);
+      enif_vfprintf (esock_dbgout, f, args);
+      va_end (args);
+      fflush(esock_dbgout);
+  }
+
+  return;
+}
+
diff --git a/erts/emulator/nifs/common/socket_dbg.h b/erts/emulator/nifs/common/socket_dbg.h
new file mode 100644
index 0000000000..8fce211a8a
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_dbg.h
@@ -0,0 +1,55 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ * Purpose : Defines and macros for the debug util of the socket and 
+ * net NIF(s).
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#ifndef SOCKET_DBG_H__
+#define SOCKET_DBG_H__
+
+/* Used when calling the init function */
+#define ESOCK_DBGOUT_DEFAULT "stdout"
+#define ESOCK_DBGOUT_UNIQUE  "unique"
+
+
+/* Used in debug printouts */
+#ifdef __WIN32__
+#define LLU "%I64u"
+#else
+#define LLU "%llu"
+#endif
+typedef unsigned long long llu_t;
+
+extern FILE* esock_dbgout; // Initiated by the 'init' function
+
+#define ESOCK_DBG_PRINTF( ___COND___ , proto ) \
+    if ( ___COND___ ) {                        \
+        esock_dbg_printf proto;                \
+        fflush(esock_dbgout);                  \
+    }
+
+
+extern void esock_dbg_init(char* filename);
+extern void esock_dbg_printf( const char* prefix, const char* format, ... );
+
+#endif // SOCKET_DBG_H__
diff --git a/erts/emulator/nifs/common/socket_int.h b/erts/emulator/nifs/common/socket_int.h
new file mode 100644
index 0000000000..4161775a04
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_int.h
@@ -0,0 +1,399 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Utility "stuff" for socket and net.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#ifndef SOCKET_INT_H__
+#define SOCKET_INT_H__
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef __WIN32__
+
+/* All this just to replace sys/socket.h, netinet/in.h and sys/un.h??? */
+#define INCL_WINSOCK_API_TYPEDEFS 1
+#ifndef WINDOWS_H_INCLUDES_WINSOCK2_H
+#include <winsock2.h>
+#endif
+#include <windows.h>
+#include <Ws2tcpip.h>   /* NEED VC 6.0 or higher */
+/* Visual studio 2008+: NTDDI_VERSION needs to be set for iphlpapi.h
+ * to define the right structures. It needs to be set to WINXP (or LONGHORN)
+ * for IPV6 to work and it's set lower by default, so we need to change it.
+ */
+#ifdef HAVE_SDKDDKVER_H
+#  include <sdkddkver.h>
+#  ifdef NTDDI_VERSION
+#    undef NTDDI_VERSION
+#  endif
+#  define NTDDI_VERSION NTDDI_WINXP
+#endif
+#include <iphlpapi.h>
+
+#else /* !__WIN32__ */
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#ifdef HAVE_SYS_UN_H
+#include <sys/un.h>
+#endif
+
+#endif
+
+#include <erl_nif.h>
+
+/* The general purpose sockaddr */
+typedef union {
+    /* General sockaddr */
+    struct sockaddr     sa;
+
+    /* IPv4 sockaddr */
+    struct sockaddr_in  in4;
+
+    /* IPv6 sockaddr */
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    struct sockaddr_in6 in6;
+#endif
+
+    /* Unix Domain Socket sockaddr */
+#if defined(HAVE_SYS_UN_H)
+    struct sockaddr_un  un;
+#endif
+
+} ESockAddress;
+
+
+/* *** Boolean *type* stuff... *** */
+typedef unsigned int BOOLEAN_T;
+#define TRUE  1
+#define FALSE 0
+
+#define BOOL2ATOM(__B__) ((__B__) ? esock_atom_true : esock_atom_false)
+
+#define B2S(__B__) ((__B__) ? "true" : "false")
+
+/* Misc error strings */
+#define ESOCK_STR_EAFNOSUPPORT "eafnosupport"
+#define ESOCK_STR_EAGAIN       "eagain"
+#define ESOCK_STR_EINVAL       "einval"
+
+
+/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ * "Global" atoms
+ *
+ * Note that when an (global) atom is added here, it must also be added
+ * in the socket_nif.c file!
+ */
+
+#define GLOBAL_ATOM_DEFS                       \
+    GLOBAL_ATOM_DEF(abort);                    \
+    GLOBAL_ATOM_DEF(accept);                   \
+    GLOBAL_ATOM_DEF(acceptconn);               \
+    GLOBAL_ATOM_DEF(acceptfilter);             \
+    GLOBAL_ATOM_DEF(adaption_layer);           \
+    GLOBAL_ATOM_DEF(addr);                     \
+    GLOBAL_ATOM_DEF(addrform);                 \
+    GLOBAL_ATOM_DEF(add_membership);           \
+    GLOBAL_ATOM_DEF(add_source_membership);    \
+    GLOBAL_ATOM_DEF(any);                      \
+    GLOBAL_ATOM_DEF(associnfo);                \
+    GLOBAL_ATOM_DEF(authhdr);                  \
+    GLOBAL_ATOM_DEF(auth_active_key);          \
+    GLOBAL_ATOM_DEF(auth_asconf);              \
+    GLOBAL_ATOM_DEF(auth_chunk);               \
+    GLOBAL_ATOM_DEF(auth_delete_key);          \
+    GLOBAL_ATOM_DEF(auth_key);                 \
+    GLOBAL_ATOM_DEF(auth_level);               \
+    GLOBAL_ATOM_DEF(autoclose);                \
+    GLOBAL_ATOM_DEF(bindtodevice);             \
+    GLOBAL_ATOM_DEF(block_source);             \
+    GLOBAL_ATOM_DEF(broadcast);                \
+    GLOBAL_ATOM_DEF(busy_poll);                \
+    GLOBAL_ATOM_DEF(checksum);                 \
+    GLOBAL_ATOM_DEF(close);                    \
+    GLOBAL_ATOM_DEF(command);                  \
+    GLOBAL_ATOM_DEF(connect);                  \
+    GLOBAL_ATOM_DEF(congestion);               \
+    GLOBAL_ATOM_DEF(context);                  \
+    GLOBAL_ATOM_DEF(cork);                     \
+    GLOBAL_ATOM_DEF(credentials);              \
+    GLOBAL_ATOM_DEF(ctrl);                     \
+    GLOBAL_ATOM_DEF(ctrunc);                   \
+    GLOBAL_ATOM_DEF(data);                     \
+    GLOBAL_ATOM_DEF(debug);                    \
+    GLOBAL_ATOM_DEF(default);      \
+    GLOBAL_ATOM_DEF(default_send_params);      \
+    GLOBAL_ATOM_DEF(delayed_ack_time);         \
+    GLOBAL_ATOM_DEF(dgram);                    \
+    GLOBAL_ATOM_DEF(disable_fragments);        \
+    GLOBAL_ATOM_DEF(domain);                   \
+    GLOBAL_ATOM_DEF(dontfrag);                 \
+    GLOBAL_ATOM_DEF(dontroute);                \
+    GLOBAL_ATOM_DEF(drop_membership);          \
+    GLOBAL_ATOM_DEF(drop_source_membership);   \
+    GLOBAL_ATOM_DEF(dstopts);                  \
+    GLOBAL_ATOM_DEF(eor);                      \
+    GLOBAL_ATOM_DEF(error);                    \
+    GLOBAL_ATOM_DEF(errqueue);                 \
+    GLOBAL_ATOM_DEF(esp_network_level);        \
+    GLOBAL_ATOM_DEF(esp_trans_level);          \
+    GLOBAL_ATOM_DEF(events);                   \
+    GLOBAL_ATOM_DEF(explicit_eor);             \
+    GLOBAL_ATOM_DEF(faith);                    \
+    GLOBAL_ATOM_DEF(false);                    \
+    GLOBAL_ATOM_DEF(family);                   \
+    GLOBAL_ATOM_DEF(flags);                    \
+    GLOBAL_ATOM_DEF(flowinfo);                 \
+    GLOBAL_ATOM_DEF(fragment_interleave);      \
+    GLOBAL_ATOM_DEF(freebind);                 \
+    GLOBAL_ATOM_DEF(get_peer_addr_info);       \
+    GLOBAL_ATOM_DEF(hdrincl);                  \
+    GLOBAL_ATOM_DEF(hmac_ident);               \
+    GLOBAL_ATOM_DEF(hoplimit);                 \
+    GLOBAL_ATOM_DEF(hopopts);                  \
+    GLOBAL_ATOM_DEF(ifindex);                  \
+    GLOBAL_ATOM_DEF(inet);                     \
+    GLOBAL_ATOM_DEF(inet6);                    \
+    GLOBAL_ATOM_DEF(info);                     \
+    GLOBAL_ATOM_DEF(initmsg);                  \
+    GLOBAL_ATOM_DEF(iov);                      \
+    GLOBAL_ATOM_DEF(ip);                       \
+    GLOBAL_ATOM_DEF(ipcomp_level);             \
+    GLOBAL_ATOM_DEF(ipv6);                     \
+    GLOBAL_ATOM_DEF(i_want_mapped_v4_addr);    \
+    GLOBAL_ATOM_DEF(join_group);               \
+    GLOBAL_ATOM_DEF(keepalive);                \
+    GLOBAL_ATOM_DEF(keepcnt);                  \
+    GLOBAL_ATOM_DEF(keepidle);                 \
+    GLOBAL_ATOM_DEF(keepintvl);                \
+    GLOBAL_ATOM_DEF(leave_group);              \
+    GLOBAL_ATOM_DEF(level);                    \
+    GLOBAL_ATOM_DEF(linger);                   \
+    GLOBAL_ATOM_DEF(local);                    \
+    GLOBAL_ATOM_DEF(local_auth_chunks);        \
+    GLOBAL_ATOM_DEF(loopback);                 \
+    GLOBAL_ATOM_DEF(lowdelay);                 \
+    GLOBAL_ATOM_DEF(mark);                     \
+    GLOBAL_ATOM_DEF(maxburst);                 \
+    GLOBAL_ATOM_DEF(maxseg);                   \
+    GLOBAL_ATOM_DEF(md5sig);                   \
+    GLOBAL_ATOM_DEF(mincost);                  \
+    GLOBAL_ATOM_DEF(minttl);                   \
+    GLOBAL_ATOM_DEF(msfilter);                 \
+    GLOBAL_ATOM_DEF(mtu);                      \
+    GLOBAL_ATOM_DEF(mtu_discover);             \
+    GLOBAL_ATOM_DEF(multicast_all);            \
+    GLOBAL_ATOM_DEF(multicast_hops);           \
+    GLOBAL_ATOM_DEF(multicast_if);             \
+    GLOBAL_ATOM_DEF(multicast_loop);           \
+    GLOBAL_ATOM_DEF(multicast_ttl);            \
+    GLOBAL_ATOM_DEF(nodelay);                  \
+    GLOBAL_ATOM_DEF(nodefrag);                 \
+    GLOBAL_ATOM_DEF(noopt);                    \
+    GLOBAL_ATOM_DEF(nopush);                   \
+    GLOBAL_ATOM_DEF(not_found);                \
+    GLOBAL_ATOM_DEF(not_owner);                \
+    GLOBAL_ATOM_DEF(ok);                       \
+    GLOBAL_ATOM_DEF(oob);                      \
+    GLOBAL_ATOM_DEF(oobinline);                \
+    GLOBAL_ATOM_DEF(options);                  \
+    GLOBAL_ATOM_DEF(origdstaddr);              \
+    GLOBAL_ATOM_DEF(partial_delivery_point);   \
+    GLOBAL_ATOM_DEF(passcred);                 \
+    GLOBAL_ATOM_DEF(path);                     \
+    GLOBAL_ATOM_DEF(peekcred);                 \
+    GLOBAL_ATOM_DEF(peek_off);                 \
+    GLOBAL_ATOM_DEF(peer_addr_params);         \
+    GLOBAL_ATOM_DEF(peer_auth_chunks);         \
+    GLOBAL_ATOM_DEF(pktinfo);                  \
+    GLOBAL_ATOM_DEF(pktoptions);               \
+    GLOBAL_ATOM_DEF(port);                     \
+    GLOBAL_ATOM_DEF(portrange);                \
+    GLOBAL_ATOM_DEF(primary_addr);             \
+    GLOBAL_ATOM_DEF(priority);                 \
+    GLOBAL_ATOM_DEF(protocol);                 \
+    GLOBAL_ATOM_DEF(raw);                      \
+    GLOBAL_ATOM_DEF(rcvbuf);                   \
+    GLOBAL_ATOM_DEF(rcvbufforce);              \
+    GLOBAL_ATOM_DEF(rcvlowat);                 \
+    GLOBAL_ATOM_DEF(rcvtimeo);                 \
+    GLOBAL_ATOM_DEF(rdm);                      \
+    GLOBAL_ATOM_DEF(recv);                     \
+    GLOBAL_ATOM_DEF(recvdstaddr);              \
+    GLOBAL_ATOM_DEF(recverr);                  \
+    GLOBAL_ATOM_DEF(recvfrom);                 \
+    GLOBAL_ATOM_DEF(recvif);                   \
+    GLOBAL_ATOM_DEF(recvmsg);                  \
+    GLOBAL_ATOM_DEF(recvopts);                 \
+    GLOBAL_ATOM_DEF(recvorigdstaddr);          \
+    GLOBAL_ATOM_DEF(recvpktinfo);              \
+    GLOBAL_ATOM_DEF(recvtclass);               \
+    GLOBAL_ATOM_DEF(recvtos);                  \
+    GLOBAL_ATOM_DEF(recvttl);                  \
+    GLOBAL_ATOM_DEF(reliability);              \
+    GLOBAL_ATOM_DEF(reset_streams);            \
+    GLOBAL_ATOM_DEF(retopts);                  \
+    GLOBAL_ATOM_DEF(reuseaddr);                \
+    GLOBAL_ATOM_DEF(reuseport);                \
+    GLOBAL_ATOM_DEF(rights);                   \
+    GLOBAL_ATOM_DEF(router_alert);             \
+    GLOBAL_ATOM_DEF(rthdr);                    \
+    GLOBAL_ATOM_DEF(rtoinfo);                  \
+    GLOBAL_ATOM_DEF(rxq_ovfl);                 \
+    GLOBAL_ATOM_DEF(scope_id);                 \
+    GLOBAL_ATOM_DEF(sctp);                     \
+    GLOBAL_ATOM_DEF(sec);                      \
+    GLOBAL_ATOM_DEF(select_failed);            \
+    GLOBAL_ATOM_DEF(select_sent);              \
+    GLOBAL_ATOM_DEF(send);                     \
+    GLOBAL_ATOM_DEF(sendmsg);                  \
+    GLOBAL_ATOM_DEF(sendsrcaddr);              \
+    GLOBAL_ATOM_DEF(sendto);                   \
+    GLOBAL_ATOM_DEF(seqpacket);                \
+    GLOBAL_ATOM_DEF(setfib);                   \
+    GLOBAL_ATOM_DEF(set_peer_primary_addr);    \
+    GLOBAL_ATOM_DEF(sndbuf);                   \
+    GLOBAL_ATOM_DEF(sndbufforce);              \
+    GLOBAL_ATOM_DEF(sndlowat);                 \
+    GLOBAL_ATOM_DEF(sndtimeo);                 \
+    GLOBAL_ATOM_DEF(socket);                   \
+    GLOBAL_ATOM_DEF(socket_tag);               \
+    GLOBAL_ATOM_DEF(spec_dst);                 \
+    GLOBAL_ATOM_DEF(status);                   \
+    GLOBAL_ATOM_DEF(stream);                   \
+    GLOBAL_ATOM_DEF(syncnt);                   \
+    GLOBAL_ATOM_DEF(tclass);                   \
+    GLOBAL_ATOM_DEF(tcp);                      \
+    GLOBAL_ATOM_DEF(throughput);               \
+    GLOBAL_ATOM_DEF(timestamp);                \
+    GLOBAL_ATOM_DEF(tos);                      \
+    GLOBAL_ATOM_DEF(transparent);              \
+    GLOBAL_ATOM_DEF(true);                     \
+    GLOBAL_ATOM_DEF(trunc);                    \
+    GLOBAL_ATOM_DEF(ttl);                      \
+    GLOBAL_ATOM_DEF(type);                     \
+    GLOBAL_ATOM_DEF(udp);                      \
+    GLOBAL_ATOM_DEF(unblock_source);           \
+    GLOBAL_ATOM_DEF(undefined);                \
+    GLOBAL_ATOM_DEF(unicast_hops);             \
+    GLOBAL_ATOM_DEF(unknown);                  \
+    GLOBAL_ATOM_DEF(usec);                     \
+    GLOBAL_ATOM_DEF(user_timeout);             \
+    GLOBAL_ATOM_DEF(use_ext_recvinfo);         \
+    GLOBAL_ATOM_DEF(use_min_mtu);              \
+    GLOBAL_ATOM_DEF(v6only);
+
+
+/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ * Error reason atoms
+ */
+
+#define GLOBAL_ERROR_REASON_ATOM_DEFS \
+    GLOBAL_ATOM_DEF(eafnosupport);    \
+    GLOBAL_ATOM_DEF(eagain);          \
+    GLOBAL_ATOM_DEF(einval);
+
+
+#define GLOBAL_ATOM_DEF(A) extern ERL_NIF_TERM esock_atom_##A
+GLOBAL_ATOM_DEFS
+GLOBAL_ERROR_REASON_ATOM_DEFS
+#undef GLOBAL_ATOM_DEF
+
+
+/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ * Various wrapper macros for enif functions
+ */
+#define MALLOC(SZ)          enif_alloc((SZ))
+#define REALLOC(P, SZ)      enif_realloc((P), (SZ))
+#define FREE(P)             enif_free((P))
+
+#define MKA(E,S)            enif_make_atom((E), (S))
+#define MKBIN(E,B)          enif_make_binary((E), (B))
+#define MKI(E,I)            enif_make_int((E), (I))
+#define MKL(E,L)            enif_make_long((E), (L))
+#define MKLA(E,A,L)         enif_make_list_from_array((E), (A), (L))
+#define MKEL(E)             enif_make_list((E), 0)
+#define MKMA(E,KA,VA,L,M)   enif_make_map_from_arrays((E), (KA), (VA), (L), (M))
+#define MKPID(E, P)         enif_make_pid((E), (P))
+#define MKREF(E)            enif_make_ref((E))
+#define MKS(E,S)            enif_make_string((E), (S), ERL_NIF_LATIN1)
+#define MKSL(E,S,L)         enif_make_string_len((E), (S), (L), ERL_NIF_LATIN1)
+#define MKSBIN(E,B,ST,SZ)   enif_make_sub_binary((E), (B), (ST), (SZ))
+#define MKT2(E,E1,E2)       enif_make_tuple2((E), (E1), (E2))
+#define MKT3(E,E1,E2,E3)    enif_make_tuple3((E), (E1), (E2), (E3))
+#define MKT4(E,E1,E2,E3,E4) enif_make_tuple4((E), (E1), (E2), (E3), (E4))
+#define MKT5(E,E1,E2,E3,E4,E5) \
+    enif_make_tuple5((E), (E1), (E2), (E3), (E4), (E5))
+#define MKT8(E,E1,E2,E3,E4,E5,E6,E7,E8) \
+    enif_make_tuple8((E), (E1), (E2), (E3), (E4), (E5), (E6), (E7), (E8))
+#define MKTA(E, A, AL)      enif_make_tuple_from_array((E), (A), (AL))
+#define MKUI(E,UI)          enif_make_uint((E), (UI))
+#define MKUL(E,UL)          enif_make_ulong((E), (UL))
+
+#define MCREATE(N)          enif_mutex_create((N))
+#define MDESTROY(M)         enif_mutex_destroy((M))
+#define MLOCK(M)            enif_mutex_lock((M))
+#define MUNLOCK(M)          enif_mutex_unlock((M))
+
+#define MONP(S,E,D,P,M)     esock_monitor((S), (E), (D), (P), (M))
+#define DEMONP(S,E,D,M)     esock_demonitor((S), (E), (D), (M))
+#define MON_INIT(M)         esock_monitor_init((M))
+#define MON2T(E, M)         enif_make_monitor_term((E), (M))
+
+#define COMPARE(A, B)        enif_compare((A), (B))
+#define COMPARE_PIDS(P1, P2) enif_compare_pids((P1), (P2))
+
+#define IS_ATOM(E,  TE) enif_is_atom((E),   (TE))
+#define IS_BIN(E,   TE) enif_is_binary((E), (TE))
+#define IS_LIST(E,  TE) enif_is_list((E),   (TE))
+#define IS_MAP(E,   TE) enif_is_map((E), (TE))
+#define IS_NUM(E,   TE) enif_is_number((E), (TE))
+#define IS_TUPLE(E, TE) enif_is_tuple((E),  (TE))
+
+#define GET_ATOM_LEN(E, TE, LP) \
+    enif_get_atom_length((E), (TE), (LP), ERL_NIF_LATIN1)
+#define GET_ATOM(E, TE, BP, MAX) \
+    enif_get_atom((E), (TE), (BP), (MAX), ERL_NIF_LATIN1)
+#define GET_BIN(E, TE, BP)          enif_inspect_iolist_as_binary((E), (TE), (BP))
+#define GET_INT(E, TE, IP)          enif_get_int((E), (TE), (IP))
+#define GET_LIST_ELEM(E, L, HP, TP) enif_get_list_cell((E), (L), (HP), (TP))
+#define GET_LIST_LEN(E, L, LP)      enif_get_list_length((E), (L), (LP))
+#define GET_LONG(E, TE, LP)         enif_get_long((E), (TE), (LP))
+#define GET_LPID(E, T, P)           enif_get_local_pid((E), (T), (P))
+#define GET_STR(E, L, B, SZ)      \
+    enif_get_string((E), (L), (B), (SZ), ERL_NIF_LATIN1)
+#define GET_UINT(E, TE, UIP)        enif_get_uint((E), (TE), (UIP))
+#define GET_ULONG(E, TE, ULP)       enif_get_long((E), (TE), (ULP))
+#define GET_TUPLE(E, TE, TSZ, TA)   enif_get_tuple((E), (TE), (TSZ), (TA))
+#define GET_MAP_VAL(E, M, K, V)     enif_get_map_value((E), (M), (K), (V))
+
+#define ALLOC_BIN(SZ, BP)         enif_alloc_binary((SZ), (BP))
+#define REALLOC_BIN(SZ, BP)       enif_realloc_binary((SZ), (BP))
+#define FREE_BIN(BP)              enif_release_binary((BP))
+
+/* Copy term T into environment E */
+#define CP_TERM(E, T) enif_make_copy((E), (T))
+
+#endif // SOCKET_INT_H__
diff --git a/erts/emulator/nifs/common/socket_nif.c b/erts/emulator/nifs/common/socket_nif.c
new file mode 100644
index 0000000000..bbeb8b6cdd
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_nif.c
@@ -0,0 +1,19697 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ * Purpose : The NIF (C) part of the socket interface
+ *
+ * All of the nif-functions which are part of the API has two parts.
+ * The first function is called 'nif_<something>', e.g. nif_open.
+ * This does the initial validation and argument processing and then 
+ * calls the function that does the actual work. This is called
+ * 'esock_<something>'.
+ * ----------------------------------------------------------------------
+ *
+ *
+ * This is just a code snippet in case there is need of extra debugging
+ *
+ * esock_dbg_printf("DEMONP", "[%d] %s: %T\r\n",
+ *                  descP->sock, slogan,
+ *                  esock_make_monitor_term(env, &mon));
+ *
+ */
+
+#define STATIC_ERLANG_NIF 1
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* If we HAVE_SCTP_H and Solaris, we need to define the following in
+ * order to get SCTP working:
+ */
+#if (defined(HAVE_SCTP_H) && defined(__sun) && defined(__SVR4))
+#define SOLARIS10    1
+/* WARNING: This is not quite correct, it may also be Solaris 11! */
+#define _XPG4_2
+#define __EXTENSIONS__
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <time.h>
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_SYS_UIO_H
+#include <sys/uio.h>
+#endif
+
+#ifdef HAVE_NET_IF_DL_H
+#include <net/if_dl.h>
+#endif
+
+#ifdef HAVE_IFADDRS_H
+#include <ifaddrs.h>
+#endif
+
+#ifdef HAVE_NETPACKET_PACKET_H
+#include <netpacket/packet.h>
+#endif
+
+#ifdef HAVE_SYS_UN_H
+#include <sys/un.h>
+#endif
+
+/* SENDFILE STUFF HERE IF WE NEED IT... */
+
+#if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__)
+#define __DARWIN__ 1
+#endif
+
+
+#ifdef __WIN32__
+#define STRNCASECMP               strncasecmp
+#define INCL_WINSOCK_API_TYPEDEFS 1
+
+#ifndef WINDOWS_H_INCLUDES_WINSOCK2_H
+#include <winsock2.h>
+#endif
+#include <windows.h>
+#include <Ws2tcpip.h>   /* NEED VC 6.0 or higher */
+
+/* Visual studio 2008+: NTDDI_VERSION needs to be set for iphlpapi.h
+ * to define the right structures. It needs to be set to WINXP (or LONGHORN)
+ * for IPV6 to work and it's set lower by default, so we need to change it.
+ */
+#ifdef HAVE_SDKDDKVER_H
+#  include <sdkddkver.h>
+#  ifdef NTDDI_VERSION
+#    undef NTDDI_VERSION
+#  endif
+#  define NTDDI_VERSION NTDDI_WINXP
+#endif
+#include <iphlpapi.h>
+
+#undef WANT_NONBLOCKING
+#include "sys.h"
+
+
+
+/* AND HERE WE MAY HAVE A BUNCH OF DEFINES....SEE INET DRIVER.... */
+
+
+
+
+#else /* ifdef __WIN32__ */
+
+#include <sys/time.h>
+#ifdef NETDB_H_NEEDS_IN_H
+#include <netinet/in.h>
+#endif
+#include <netdb.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#ifdef DEF_INADDR_LOOPBACK_IN_RPC_TYPES_H
+#include <rpc/types.h>
+#endif
+
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <arpa/inet.h>
+
+#include <sys/param.h>
+#ifdef HAVE_ARPA_NAMESER_H
+#include <arpa/nameser.h>
+#endif
+
+#ifdef HAVE_SYS_SOCKIO_H
+#include <sys/sockio.h>
+#endif
+
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
+#include <net/if.h>
+
+#ifdef HAVE_SCHED_H
+#include <sched.h>
+#endif
+
+#ifdef HAVE_SETNS_H
+#include <setns.h>
+#endif
+
+#define HAVE_UDP
+
+/* SCTP support -- currently for UNIX platforms only: */
+#undef HAVE_SCTP
+#if defined(HAVE_SCTP_H)
+
+#include <netinet/sctp.h>
+
+/* SCTP Socket API Draft from version 11 on specifies that netinet/sctp.h must
+   explicitly define HAVE_SCTP in case when SCTP is supported,  but Solaris 10
+   still apparently uses Draft 10, and does not define that symbol, so we have
+   to define it explicitly:
+*/
+#ifndef     HAVE_SCTP
+#    define HAVE_SCTP
+#endif
+
+/* These changed in draft 11, so SOLARIS10 uses the old MSG_* */
+#if ! HAVE_DECL_SCTP_UNORDERED
+#     define    SCTP_UNORDERED  MSG_UNORDERED
+#endif
+#if ! HAVE_DECL_SCTP_ADDR_OVER
+#     define    SCTP_ADDR_OVER  MSG_ADDR_OVER
+#endif
+#if ! HAVE_DECL_SCTP_ABORT
+#     define    SCTP_ABORT      MSG_ABORT
+#endif
+#if ! HAVE_DECL_SCTP_EOF
+#     define    SCTP_EOF        MSG_EOF
+#endif
+
+/* More Solaris 10 fixes: */
+#if ! HAVE_DECL_SCTP_CLOSED && HAVE_DECL_SCTPS_IDLE
+#    define SCTP_CLOSED SCTPS_IDLE
+#    undef HAVE_DECL_SCTP_CLOSED
+#    define HAVE_DECL_SCTP_CLOSED 1
+#endif
+#if ! HAVE_DECL_SCTP_BOUND && HAVE_DECL_SCTPS_BOUND
+#    define SCTP_BOUND SCTPS_BOUND
+#    undef HAVE_DECL_SCTP_BOUND
+#    define HAVE_DECL_SCTP_BOUND 1
+#endif
+#if ! HAVE_DECL_SCTP_LISTEN && HAVE_DECL_SCTPS_LISTEN
+#    define SCTP_LISTEN SCTPS_LISTEN
+#    undef HAVE_DECL_SCTP_LISTEN
+#    define HAVE_DECL_SCTP_LISTEN 1
+#endif
+#if ! HAVE_DECL_SCTP_COOKIE_WAIT && HAVE_DECL_SCTPS_COOKIE_WAIT
+#    define SCTP_COOKIE_WAIT SCTPS_COOKIE_WAIT
+#    undef HAVE_DECL_SCTP_COOKIE_WAIT
+#    define HAVE_DECL_SCTP_COOKIE_WAIT 1
+#endif
+#if ! HAVE_DECL_SCTP_COOKIE_ECHOED && HAVE_DECL_SCTPS_COOKIE_ECHOED
+#    define SCTP_COOKIE_ECHOED SCTPS_COOKIE_ECHOED
+#    undef HAVE_DECL_SCTP_COOKIE_ECHOED
+#    define HAVE_DECL_SCTP_COOKIE_ECHOED 1
+#endif
+#if ! HAVE_DECL_SCTP_ESTABLISHED && HAVE_DECL_SCTPS_ESTABLISHED
+#    define SCTP_ESTABLISHED SCTPS_ESTABLISHED
+#    undef HAVE_DECL_SCTP_ESTABLISHED
+#    define HAVE_DECL_SCTP_ESTABLISHED 1
+#endif
+#if ! HAVE_DECL_SCTP_SHUTDOWN_PENDING && HAVE_DECL_SCTPS_SHUTDOWN_PENDING
+#    define SCTP_SHUTDOWN_PENDING SCTPS_SHUTDOWN_PENDING
+#    undef HAVE_DECL_SCTP_SHUTDOWN_PENDING
+#    define HAVE_DECL_SCTP_SHUTDOWN_PENDING 1
+#endif
+#if ! HAVE_DECL_SCTP_SHUTDOWN_SENT && HAVE_DECL_SCTPS_SHUTDOWN_SENT
+#    define SCTP_SHUTDOWN_SENT SCTPS_SHUTDOWN_SENT
+#    undef HAVE_DECL_SCTP_SHUTDOWN_SENT
+#    define HAVE_DECL_SCTP_SHUTDOWN_SENT 1
+#endif
+#if ! HAVE_DECL_SCTP_SHUTDOWN_RECEIVED && HAVE_DECL_SCTPS_SHUTDOWN_RECEIVED
+#    define SCTP_SHUTDOWN_RECEIVED SCTPS_SHUTDOWN_RECEIVED
+#    undef HAVE_DECL_SCTP_SHUTDOWN_RECEIVED
+#    define HAVE_DECL_SCTP_SHUTDOWN_RECEIVED 1
+#endif
+#if ! HAVE_DECL_SCTP_SHUTDOWN_ACK_SENT && HAVE_DECL_SCTPS_SHUTDOWN_ACK_SENT
+#    define SCTP_SHUTDOWN_ACK_SENT SCTPS_SHUTDOWN_ACK_SENT
+#    undef HAVE_DECL_SCTP_SHUTDOWN_ACK_SENT
+#    define HAVE_DECL_SCTP_SHUTDOWN_ACK_SENT 1
+#endif
+/* New spelling in lksctp 2.6.22 or maybe even earlier:
+ *  adaption -> adaptation
+ */
+#if !defined(SCTP_ADAPTATION_LAYER) && defined (SCTP_ADAPTION_LAYER)
+#     define SCTP_ADAPTATION_LAYER       SCTP_ADAPTION_LAYER
+#     define SCTP_ADAPTATION_INDICATION  SCTP_ADAPTION_INDICATION
+#     define sctp_adaptation_event       sctp_adaption_event
+#     define sctp_setadaptation          sctp_setadaption
+#     define sn_adaptation_event         sn_adaption_event
+#     define sai_adaptation_ind          sai_adaption_ind
+#     define ssb_adaptation_ind          ssb_adaption_ind
+#     define sctp_adaptation_layer_event sctp_adaption_layer_event
+#endif
+
+/*
+ * We *may* need this stuff later when we *fully* implement support for SCTP 
+ *
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_BINDX)
+static typeof(sctp_bindx) *esock_sctp_bindx = NULL;
+#else
+static int (*esock_sctp_bindx)
+	(int sd, struct sockaddr *addrs, int addrcnt, int flags) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_PEELOFF)
+static typeof(sctp_peeloff) *esock_sctp_peeloff = NULL;
+#else
+static int (*esock_sctp_peeloff)
+        (int sd, sctp_assoc_t assoc_id) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_GETLADDRS)
+static typeof(sctp_getladdrs) *esock_sctp_getladdrs = NULL;
+#else
+static int (*esock_sctp_getladdrs)
+        (int sd, sctp_assoc_t assoc_id, struct sockaddr **ss) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_FREELADDRS)
+static typeof(sctp_freeladdrs) *esock_sctp_freeladdrs = NULL;
+#else
+static void (*esock_sctp_freeladdrs)(struct sockaddr *addrs) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_GETPADDRS)
+static typeof(sctp_getpaddrs) *esock_sctp_getpaddrs = NULL;
+#else
+static int (*esock_sctp_getpaddrs)
+        (int sd, sctp_assoc_t assoc_id, struct sockaddr **ss) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_FREEPADDRS)
+static typeof(sctp_freepaddrs) *esock_sctp_freepaddrs = NULL;
+#else
+static void (*esock_sctp_freepaddrs)(struct sockaddr *addrs) = NULL;
+#endif
+
+*/
+
+#endif /* #if defined(HAVE_SCTP_H) */
+
+
+#ifndef WANT_NONBLOCKING
+#define WANT_NONBLOCKING
+#endif
+#include "sys.h"
+
+/* Socket stuff */
+#define INVALID_SOCKET -1
+// #define INVALID_EVENT  -1
+#define SOCKET_ERROR   -1
+
+#endif /* ifdef __WIN32__ */
+
+#include <erl_nif.h>
+
+#include "socket_dbg.h"
+#include "socket_tarray.h"
+#include "socket_int.h"
+#include "socket_util.h"
+
+
+#if defined(ERTS_INLINE)
+#  define ESOCK_INLINE ERTS_INLINE
+#else
+#  if defined(__GNUC__)
+#    define ESOCK_INLINE __inline__
+#  elif defined(__WIN32__)
+#    define ESOCK_INLINE __inline
+#  else
+#    define ESOCK_INLINE
+#  endif
+#endif
+
+
+#if defined(SOL_IPV6) || defined(IPPROTO_IPV6)
+#define HAVE_IPV6
+#endif
+
+/* All platforms fail on malloc errors. */
+#define FATAL_MALLOC
+
+
+/* Debug stuff... */
+#define ESOCK_GLOBAL_DEBUG_DEFAULT FALSE
+#define ESOCK_DEBUG_DEFAULT        FALSE
+
+/* Counters and stuff (Don't know where to sent this stuff anyway) */
+#define ESOCK_NIF_IOW_DEFAULT FALSE
+
+
+
+/* Socket stuff */
+#define INVALID_EVENT  -1
+
+#define SOCKET int
+#define HANDLE long int
+
+
+/* ==============================================================================
+ * The IS_SOCKET_ERROR macro below is used for portability reasons.
+ * While POSIX specifies that errors from socket-related system calls
+ * should be indicated with a -1 return value, some users have experienced
+ * non-Windows OS kernels that return negative values other than -1.
+ * While one can argue that such kernels are technically broken, comparing
+ * against values less than 0 covers their out-of-spec return values without
+ * imposing incorrect semantics on systems that manage to correctly return -1
+ * for errors, thus increasing Erlang's portability.
+ */
+#ifdef __WIN32__
+#define IS_SOCKET_ERROR(val) ((val) == SOCKET_ERROR)
+#else
+#define IS_SOCKET_ERROR(val) ((val) < 0)
+#endif
+
+
+/* *** Misc macros and defines *** */
+
+/* This macro exist on some (linux) platforms */
+#if !defined(IPTOS_TOS_MASK)
+#define IPTOS_TOS_MASK     0x1E
+#endif
+#if !defined(IPTOS_TOS)
+#define IPTOS_TOS(tos)          ((tos)&IPTOS_TOS_MASK)
+#endif
+
+
+#if defined(TCP_CA_NAME_MAX)
+#define ESOCK_OPT_TCP_CONGESTION_NAME_MAX TCP_CA_NAME_MAX
+#else
+/* This is really excessive, but just in case... */
+#define ESOCK_OPT_TCP_CONGESTION_NAME_MAX 256
+#endif
+
+
+#if defined(TCP_CONGESTION) || defined(SO_BINDTODEVICE)
+#define USE_GETOPT_STR_OPT
+#define USE_SETOPT_STR_OPT
+#endif
+
+
+
+/* *** Socket state defs *** */
+
+#define ESOCK_FLAG_OPEN         0x0001
+#define ESOCK_FLAG_ACTIVE       0x0004
+#define ESOCK_FLAG_LISTEN       0x0008
+#define ESOCK_FLAG_CON          0x0010
+#define ESOCK_FLAG_ACC          0x0020
+#define ESOCK_FLAG_BUSY         0x0040
+#define ESOCK_FLAG_CLOSE        0x0080
+
+#define ESOCK_STATE_CLOSED          (0)
+#define ESOCK_STATE_OPEN            (ESOCK_FLAG_OPEN)
+#define ESOCK_STATE_CONNECTED       (ESOCK_STATE_OPEN      | ESOCK_FLAG_ACTIVE)
+#define ESOCK_STATE_LISTENING       (ESOCK_STATE_OPEN      | ESOCK_FLAG_LISTEN)
+#define ESOCK_STATE_CONNECTING      (ESOCK_STATE_OPEN      | ESOCK_FLAG_CON)
+#define ESOCK_STATE_ACCEPTING       (ESOCK_STATE_LISTENING | ESOCK_FLAG_ACC)
+#define ESOCK_STATE_CLOSING         (ESOCK_FLAG_CLOSE)
+#define ESOCK_STATE_DTOR            (0xFFFF)
+
+#define IS_CLOSED(d)                            \
+    ((d)->state == ESOCK_STATE_CLOSED)
+
+/*
+#define IS_STATE(d, f) \
+    (((d)->state & (f)) == (f))
+*/
+
+#define IS_CLOSING(d)                                                   \
+    (((d)->state & ESOCK_STATE_CLOSING) == ESOCK_STATE_CLOSING)
+
+#define IS_OPEN(d)                                              \
+    (((d)->state & ESOCK_FLAG_OPEN) == ESOCK_FLAG_OPEN)
+
+#define IS_CONNECTED(d)                                                 \
+    (((d)->state & ESOCK_STATE_CONNECTED) == ESOCK_STATE_CONNECTED)
+
+#define IS_CONNECTING(d)                                \
+    (((d)->state & ESOCK_FLAG_CON) == ESOCK_FLAG_CON)
+
+/*
+#define IS_BUSY(d)                                      \
+    (((d)->state & ESOCK_FLAG_BUSY) == ESOCK_FLAG_BUSY)
+*/
+
+#define ESOCK_GET_RESOURCE(ENV, REF, RES) \
+    enif_get_resource((ENV), (REF), esocks, (RES))
+
+#define ESOCK_SEND_FLAG_CONFIRM    0
+#define ESOCK_SEND_FLAG_DONTROUTE  1
+#define ESOCK_SEND_FLAG_EOR        2
+#define ESOCK_SEND_FLAG_MORE       3
+#define ESOCK_SEND_FLAG_NOSIGNAL   4
+#define ESOCK_SEND_FLAG_OOB        5
+#define ESOCK_SEND_FLAG_LOW        ESOCK_SEND_FLAG_CONFIRM
+#define ESOCK_SEND_FLAG_HIGH       ESOCK_SEND_FLAG_OOB
+
+#define ESOCK_RECV_FLAG_CMSG_CLOEXEC 0
+#define ESOCK_RECV_FLAG_ERRQUEUE     1
+#define ESOCK_RECV_FLAG_OOB          2
+#define ESOCK_RECV_FLAG_PEEK         3
+#define ESOCK_RECV_FLAG_TRUNC        4
+#define ESOCK_RECV_FLAG_LOW          ESOCK_RECV_FLAG_CMSG_CLOEXEC
+#define ESOCK_RECV_FLAG_HIGH         ESOCK_RECV_FLAG_TRUNC
+
+#define ESOCK_RECV_BUFFER_SIZE_DEFAULT      8192
+#define ESOCK_RECV_CTRL_BUFFER_SIZE_DEFAULT 1024
+#define ESOCK_SEND_CTRL_BUFFER_SIZE_DEFAULT 1024
+
+#define VT2S(__VT__) (((__VT__) == ESOCK_OPT_VALUE_TYPE_UNSPEC) ? "unspec" : \
+                      (((__VT__) == ESOCK_OPT_VALUE_TYPE_INT) ? "int" : \
+                       ((__VT__) == ESOCK_OPT_VALUE_TYPE_BOOL) ? "bool" : \
+                       "undef"))
+
+#define ESOCK_OPT_VALUE_TYPE_UNSPEC 0
+#define ESOCK_OPT_VALUE_TYPE_INT    1
+#define ESOCK_OPT_VALUE_TYPE_BOOL   2
+
+#define ESOCK_DESC_PATTERN_CREATED 0x03030303
+#define ESOCK_DESC_PATTERN_DTOR    0xC0C0C0C0
+
+/*
+typedef union {
+    struct {
+        // 0 = not open, 1 = open
+        unsigned int open:1;
+        // 0 = not conn, 1 = connecting, 2 = connected
+        unsigned int connect:2;
+        // unsigned int connecting:1;
+        // unsigned int connected:1;
+        // 0 = not listen, 1 = listening, 2 = accepting
+        unsigned int listen:2;
+        // unsigned int listening:1;
+        // unsigned int accepting:1;
+        / * Room for more... * /
+    } flags;
+    unsigned int field; // Make it easy to reset all flags...
+} SocketState;
+*/
+
+/*
+#define IS_OPEN(d)       ((d)->state.flags.open)
+#define IS_CONNECTED(d)  ((d)->state.flags.connect == ESOCK_STATE_CONNECTED)
+#define IS_CONNECTING(d) ((d)->state.flags.connect == ESOCK_STATE_CONNECTING)
+*/
+
+
+/*----------------------------------------------------------------------------
+ * Interface constants.
+ *
+ * This section must be "identical" to the corresponding socket.hrl
+ */
+
+/* domain */
+#define ESOCK_DOMAIN_LOCAL       1
+#define ESOCK_DOMAIN_INET        2
+#define ESOCK_DOMAIN_INET6       3
+
+/* type */
+#define ESOCK_TYPE_STREAM        1
+#define ESOCK_TYPE_DGRAM         2
+#define ESOCK_TYPE_RAW           3
+// #define ESOCK_TYPE_RDM           4
+#define ESOCK_TYPE_SEQPACKET     5
+
+/* protocol */
+#define ESOCK_PROTOCOL_DEFAULT   0
+#define ESOCK_PROTOCOL_IP        1
+#define ESOCK_PROTOCOL_TCP       2
+#define ESOCK_PROTOCOL_UDP       3
+#define ESOCK_PROTOCOL_SCTP      4
+#define ESOCK_PROTOCOL_ICMP      5
+#define ESOCK_PROTOCOL_IGMP      6
+
+/* shutdown how */
+#define ESOCK_SHUTDOWN_HOW_RD    0
+#define ESOCK_SHUTDOWN_HOW_WR    1
+#define ESOCK_SHUTDOWN_HOW_RDWR  2
+
+
+#define ESOCK_OPT_LEVEL_OTP        0
+#define ESOCK_OPT_LEVEL_SOCKET     1
+#define ESOCK_OPT_LEVEL_IP         2
+#define ESOCK_OPT_LEVEL_IPV6       3
+#define ESOCK_OPT_LEVEL_TCP        4
+#define ESOCK_OPT_LEVEL_UDP        5
+#define ESOCK_OPT_LEVEL_SCTP       6
+
+#define ESOCK_OPT_OTP_DEBUG        1
+#define ESOCK_OPT_OTP_IOW          2
+#define ESOCK_OPT_OTP_CTRL_PROC    3
+#define ESOCK_OPT_OTP_RCVBUF       4
+#define ESOCK_OPT_OTP_RCVCTRLBUF   6
+#define ESOCK_OPT_OTP_SNDCTRLBUF   7
+#define ESOCK_OPT_OTP_FD           8
+#define ESOCK_OPT_OTP_DOMAIN       0xFF01 // INTERNAL AND ONLY GET
+#define ESOCK_OPT_OTP_TYPE         0xFF02 // INTERNAL AND ONLY GET
+#define ESOCK_OPT_OTP_PROTOCOL     0xFF03 // INTERNAL AND ONLY GET
+
+#define ESOCK_OPT_SOCK_ACCEPTCONN     1
+#define ESOCK_OPT_SOCK_BINDTODEVICE   3
+#define ESOCK_OPT_SOCK_BROADCAST      4
+#define ESOCK_OPT_SOCK_DEBUG          6
+#define ESOCK_OPT_SOCK_DOMAIN         7
+#define ESOCK_OPT_SOCK_DONTROUTE      8
+#define ESOCK_OPT_SOCK_KEEPALIVE     10
+#define ESOCK_OPT_SOCK_LINGER        11
+#define ESOCK_OPT_SOCK_OOBINLINE     13
+#define ESOCK_OPT_SOCK_PEEK_OFF      15
+#define ESOCK_OPT_SOCK_PRIORITY      17
+#define ESOCK_OPT_SOCK_PROTOCOL      18
+#define ESOCK_OPT_SOCK_RCVBUF        19
+#define ESOCK_OPT_SOCK_RCVLOWAT      21
+#define ESOCK_OPT_SOCK_RCVTIMEO      22
+#define ESOCK_OPT_SOCK_REUSEADDR     23
+#define ESOCK_OPT_SOCK_REUSEPORT     24
+#define ESOCK_OPT_SOCK_SNDBUF        27
+#define ESOCK_OPT_SOCK_SNDLOWAT      29
+#define ESOCK_OPT_SOCK_SNDTIMEO      30
+#define ESOCK_OPT_SOCK_TIMESTAMP     31
+#define ESOCK_OPT_SOCK_TYPE          32
+
+#define ESOCK_OPT_IP_ADD_MEMBERSHIP          1
+#define ESOCK_OPT_IP_ADD_SOURCE_MEMBERSHIP   2
+#define ESOCK_OPT_IP_BLOCK_SOURCE            3
+#define ESOCK_OPT_IP_DROP_MEMBERSHIP         5
+#define ESOCK_OPT_IP_DROP_SOURCE_MEMBERSHIP  6
+#define ESOCK_OPT_IP_FREEBIND                7
+#define ESOCK_OPT_IP_HDRINCL                 8
+#define ESOCK_OPT_IP_MINTTL                  9
+#define ESOCK_OPT_IP_MSFILTER               10
+#define ESOCK_OPT_IP_MTU                    11
+#define ESOCK_OPT_IP_MTU_DISCOVER           12
+#define ESOCK_OPT_IP_MULTICAST_ALL          13
+#define ESOCK_OPT_IP_MULTICAST_IF           14
+#define ESOCK_OPT_IP_MULTICAST_LOOP         15
+#define ESOCK_OPT_IP_MULTICAST_TTL          16
+#define ESOCK_OPT_IP_NODEFRAG               17
+#define ESOCK_OPT_IP_PKTINFO                19
+#define ESOCK_OPT_IP_RECVDSTADDR            20
+#define ESOCK_OPT_IP_RECVERR                21
+#define ESOCK_OPT_IP_RECVIF                 22
+#define ESOCK_OPT_IP_RECVOPTS               23
+#define ESOCK_OPT_IP_RECVORIGDSTADDR        24
+#define ESOCK_OPT_IP_RECVTOS                25
+#define ESOCK_OPT_IP_RECVTTL                26
+#define ESOCK_OPT_IP_RETOPTS                27
+#define ESOCK_OPT_IP_ROUTER_ALERT           28
+#define ESOCK_OPT_IP_SENDSRCADDR            29 // Same as IP_RECVDSTADDR?
+#define ESOCK_OPT_IP_TOS                    30
+#define ESOCK_OPT_IP_TRANSPARENT            31
+#define ESOCK_OPT_IP_TTL                    32
+#define ESOCK_OPT_IP_UNBLOCK_SOURCE         33
+
+#define ESOCK_OPT_IPV6_ADDRFORM              1
+#define ESOCK_OPT_IPV6_ADD_MEMBERSHIP        2
+#define ESOCK_OPT_IPV6_AUTHHDR               3
+#define ESOCK_OPT_IPV6_DROP_MEMBERSHIP       6
+#define ESOCK_OPT_IPV6_DSTOPTS               7
+#define ESOCK_OPT_IPV6_FLOWINFO             11
+#define ESOCK_OPT_IPV6_HOPLIMIT             12
+#define ESOCK_OPT_IPV6_HOPOPTS              13
+#define ESOCK_OPT_IPV6_MTU                  17
+#define ESOCK_OPT_IPV6_MTU_DISCOVER         18
+#define ESOCK_OPT_IPV6_MULTICAST_HOPS       19
+#define ESOCK_OPT_IPV6_MULTICAST_IF         20
+#define ESOCK_OPT_IPV6_MULTICAST_LOOP       21
+#define ESOCK_OPT_IPV6_RECVERR              24
+#define ESOCK_OPT_IPV6_RECVPKTINFO          25 // PKTINFO on FreeBSD
+#define ESOCK_OPT_IPV6_ROUTER_ALERT         27
+#define ESOCK_OPT_IPV6_RTHDR                28
+#define ESOCK_OPT_IPV6_UNICAST_HOPS         30
+#define ESOCK_OPT_IPV6_V6ONLY               32
+
+#define ESOCK_OPT_TCP_CONGESTION   1
+#define ESOCK_OPT_TCP_CORK         2
+#define ESOCK_OPT_TCP_MAXSEG       7
+#define ESOCK_OPT_TCP_NODELAY      9
+
+#define ESOCK_OPT_UDP_CORK         1
+
+#define ESOCK_OPT_SCTP_ASSOCINFO           2
+#define ESOCK_OPT_SCTP_AUTOCLOSE           8
+#define ESOCK_OPT_SCTP_DISABLE_FRAGMENTS  12
+#define ESOCK_OPT_SCTP_EVENTS             14
+#define ESOCK_OPT_SCTP_INITMSG            18
+#define ESOCK_OPT_SCTP_MAXSEG             21
+#define ESOCK_OPT_SCTP_NODELAY            23
+#define ESOCK_OPT_SCTP_RTOINFO            29
+
+/* We should *eventually* use this instead of hard-coding the size (to 1) */
+#define ESOCK_RECVMSG_IOVEC_SZ 1
+
+#define ESOCK_CMD_DEBUG        0x0001
+
+#define ESOCK_SUPPORTS_OPTIONS 0x0001
+#define ESOCK_SUPPORTS_SCTP    0x0002
+#define ESOCK_SUPPORTS_IPV6    0x0003
+#define ESOCK_SUPPORTS_LOCAL   0x0004
+
+#define ESOCK_WHICH_PROTO_ERROR -1
+#define ESOCK_WHICH_PROTO_UNSUP -2
+
+
+
+/* =================================================================== *
+ *                                                                     *
+ *                        Various esockmacros                          *
+ *                                                                     *
+ * =================================================================== */
+
+/* Global socket debug */
+#define SGDBG( proto )         ESOCK_DBG_PRINTF( data.dbg , proto )
+/* Socket specific debug */
+#define SSDBG( __D__ , proto ) ESOCK_DBG_PRINTF( (__D__)->dbg , proto )
+
+#define SOCK_CNT_INC( __E__, __D__, SF, ACNT, CNT, INC)  \
+    {                                                    \
+        if (cnt_inc(CNT, INC) && (__D__)->iow) {         \
+            esock_send_wrap_msg(__E__, __D__, SF, ACNT); \
+        }                                                \
+    }
+
+
+/* =================================================================== *
+ *                                                                     *
+ *                    Basic socket operations                          *
+ *                                                                     *
+ * =================================================================== */
+
+#ifdef __WIN32__
+
+/* *** Windows macros *** */
+
+#define sock_accept(s, addr, len) \
+    make_noninheritable_handle(accept((s), (addr), (len)))
+#define sock_bind(s, addr, len)        bind((s), (addr), (len))
+#define sock_close(s)                  closesocket((s))
+#define sock_close_event(e)            WSACloseEvent(e)
+#define sock_connect(s, addr, len)     connect((s), (addr), (len))
+#define sock_create_event(s)           WSACreateEvent()
+#define sock_errno()                   WSAGetLastError()
+#define sock_getopt(s,l,o,v,ln)        getsockopt((s),(l),(o),(v),(ln))
+#define sock_htons(x)                  htons((x))
+#define sock_htonl(x)                  htonl((x))
+#define sock_listen(s, b)              listen((s), (b))
+#define sock_name(s, addr, len)        getsockname((s), (addr), (len))
+#define sock_ntohs(x)                  ntohs((x))
+#define sock_open(domain, type, proto)                             \
+    make_noninheritable_handle(socket((domain), (type), (proto)))
+#define sock_peer(s, addr, len)    getpeername((s), (addr), (len))
+#define sock_recv(s,buf,len,flag)  recv((s),(buf),(len),(flag))
+#define sock_recvfrom(s,buf,blen,flag,addr,alen) \
+    recvfrom((s),(buf),(blen),(flag),(addr),(alen))
+#define sock_send(s,buf,len,flag)      send((s),(buf),(len),(flag))
+#define sock_sendto(s,buf,blen,flag,addr,alen) \
+    sendto((s),(buf),(blen),(flag),(addr),(alen))
+#define sock_setopt(s,l,o,v,ln)        setsockopt((s),(l),(o),(v),(ln))
+#define sock_shutdown(s, how)          shutdown((s), (how))
+
+
+#define SET_BLOCKING(s)            ioctlsocket(s, FIONBIO, &zero_value)
+#define SET_NONBLOCKING(s)         ioctlsocket(s, FIONBIO, &one_value)
+static unsigned long zero_value = 0;
+static unsigned long one_value  = 1;
+
+
+#else /* !__WIN32__ */
+
+
+#ifdef HAS_ACCEPT4
+// We have to figure out what the flags are...
+#define sock_accept(s, addr, len)       accept4((s), (addr), (len), (SOCK_CLOEXEC))
+#else
+#define sock_accept(s, addr, len)       accept((s), (addr), (len))
+#endif
+#define sock_bind(s, addr, len)         bind((s), (addr), (len))
+#define sock_close(s)                   close((s))
+#define sock_close_event(e)             /* do nothing */
+#define sock_connect(s, addr, len)      connect((s), (addr), (len))
+#define sock_create_event(s)            (s) /* return file descriptor */
+#define sock_errno()                    errno
+#define sock_getopt(s,t,n,v,l)          getsockopt((s),(t),(n),(v),(l))
+#define sock_htons(x)                   htons((x))
+#define sock_htonl(x)                   htonl((x))
+#define sock_listen(s, b)               listen((s), (b))
+#define sock_name(s, addr, len)         getsockname((s), (addr), (len))
+#define sock_ntohs(x)                   ntohs((x))
+#define sock_open(domain, type, proto)  socket((domain), (type), (proto))
+#define sock_peer(s, addr, len)         getpeername((s), (addr), (len))
+#define sock_recv(s,buf,len,flag)       recv((s),(buf),(len),(flag))
+#define sock_recvfrom(s,buf,blen,flag,addr,alen) \
+    recvfrom((s),(buf),(blen),(flag),(addr),(alen))
+#define sock_recvmsg(s,msghdr,flag)     recvmsg((s),(msghdr),(flag))
+#define sock_send(s,buf,len,flag)       send((s), (buf), (len), (flag))
+#define sock_sendmsg(s,msghdr,flag)     sendmsg((s),(msghdr),(flag))
+#define sock_sendto(s,buf,blen,flag,addr,alen) \
+                sendto((s),(buf),(blen),(flag),(addr),(alen))
+#define sock_setopt(s,l,o,v,ln)         setsockopt((s),(l),(o),(v),(ln))
+#define sock_shutdown(s, how)           shutdown((s), (how))
+
+#endif /* !__WIN32__ */
+
+#ifdef HAVE_SOCKLEN_T
+#  define SOCKLEN_T socklen_t
+#else
+#  define SOCKLEN_T size_t
+#endif
+
+#ifdef __WIN32__
+#define SOCKOPTLEN_T int
+#else
+#define SOCKOPTLEN_T SOCKLEN_T
+#endif
+
+/* We can use the IPv4 def for this since the beginning
+ * is the same for INET and INET6 */
+#define which_address_port(sap)		     \
+  ((((sap)->in4.sin_family == AF_INET) ||  \
+    ((sap)->in4.sin_family == AF_INET6)) ? \
+   ((sap)->in4.sin_port) : -1)
+
+
+typedef struct {
+    ErlNifMonitor mon;
+    BOOLEAN_T     isActive;
+} ESockMonitor;
+
+typedef struct {
+    ErlNifPid    pid; // PID of the requesting process
+    ESockMonitor mon; // Monitor to the requesting process
+
+    /* We need an environment for the copy of the ref we store here.
+     * We will also use this environment for any messages we send
+     * (with the ref in it). Such as the select message (used in the 
+     * select call) or the abort message.
+     */
+    ErlNifEnv*   env;
+    ERL_NIF_TERM ref; // The (unique) reference (ID) of the request
+} ESockRequestor;
+
+typedef struct esock_request_queue_element {
+    struct esock_request_queue_element* nextP;
+    ESockRequestor                      data;
+} ESockRequestQueueElement;
+
+typedef struct {
+    ESockRequestQueueElement* first;
+    ESockRequestQueueElement* last;
+} ESockRequestQueue;
+
+
+typedef struct {
+    /* 
+     * +++ This is a way to, possibly, detect memory overrides "and stuff" +++
+     *
+     * We have two patterns. One is set when the descriptor is created (allocated)
+     * and one is set when the descriptor is dtor'ed.
+     */
+    Uint32             pattern;
+
+    /* +++ The actual socket +++ */
+    SOCKET             sock;
+    HANDLE             event;
+
+    /* +++ Stuff "about" the socket +++ */
+    int                domain;
+    int                type;
+    int                protocol;
+
+    unsigned int       state;
+    ESockAddress       remote;
+    unsigned int       addrLen;
+
+    /* +++ Controller (owner) process +++ */
+    ErlNifPid          ctrlPid;
+    ESockMonitor       ctrlMon;
+
+    /* +++ Connector process +++ */
+    ErlNifPid          connPid;
+    ESockMonitor       connMon;
+
+    /* +++ Write stuff +++ */
+    ErlNifMutex*       writeMtx;
+    ESockRequestor     currentWriter;
+    ESockRequestor*    currentWriterP; // NULL or points to currentWriter
+    ESockRequestQueue  writersQ;
+    BOOLEAN_T          isWritable;
+    Uint32             writePkgCnt;
+    Uint32             writeByteCnt;
+    Uint32             writeTries;
+    Uint32             writeWaits;
+    Uint32             writeFails;
+
+    /* +++ Read stuff +++ */
+    ErlNifMutex*       readMtx;
+    ESockRequestor     currentReader;
+    ESockRequestor*    currentReaderP; // NULL or points to currentReader
+    ESockRequestQueue  readersQ;
+    BOOLEAN_T          isReadable;
+    ErlNifBinary       rbuffer;      // DO WE NEED THIS
+    Uint32             readCapacity; // DO WE NEED THIS
+    Uint32             readPkgCnt;
+    Uint32             readByteCnt;
+    Uint32             readTries;
+    Uint32             readWaits;
+    Uint32             readFails;
+
+    /* +++ Accept stuff +++ */
+    ErlNifMutex*       accMtx;
+    ESockRequestor     currentAcceptor;
+    ESockRequestor*    currentAcceptorP; // NULL or points to currentAcceptor
+    ESockRequestQueue  acceptorsQ;
+
+    /* +++ Config & Misc stuff +++ */
+    ErlNifMutex*       cfgMtx;
+    size_t       rBufSz;  // Read buffer size (when data length = 0)
+    /* rNum and rNumCnt are used (together with rBufSz) when calling the recv 
+     * function with the Length argument set to 0 (zero).
+     * If rNum is 0 (zero), then rNumCnt is not used and only *one* read will
+     * be done. Also, when get'ing the value of the option (rcvbuf) with 
+     * getopt, the value will be reported as an integer. If the rNum has a 
+     * value greater then 0 (zero), then it will instead be reported as {N, BufSz}.
+     */
+    unsigned int rNum;    // recv: Number of reads using rBufSz
+    unsigned int rNumCnt; // recv: Current number of reads (so far)
+    size_t       rCtrlSz; // Read control buffer size
+    size_t       wCtrlSz; // Write control buffer size
+    BOOLEAN_T    iow;     // Inform On (counter) Wrap
+    BOOLEAN_T    dbg;
+
+    /* +++ Close stuff +++ */
+    ErlNifMutex*  closeMtx;
+    ErlNifPid     closerPid;
+    ESockMonitor  closerMon;
+    ErlNifEnv*    closeEnv;
+    ERL_NIF_TERM  closeRef;
+    BOOLEAN_T     closeLocal;
+
+} ESockDescriptor;
+
+
+/* Global stuff.
+ */
+typedef struct {
+    /* These are for debugging, testing and the like */
+    // ERL_NIF_TERM version;
+    // ERL_NIF_TERM buildDate;
+    BOOLEAN_T    dbg;
+
+    BOOLEAN_T    iow; // Where do we send this? Subscription?
+    ErlNifMutex* cntMtx;
+    Uint32       numSockets;
+    Uint32       numTypeStreams;
+    Uint32       numTypeDGrams;
+    Uint32       numTypeSeqPkgs;
+    Uint32       numDomainInet;
+    Uint32       numDomainInet6;
+    Uint32       numDomainLocal;
+    Uint32       numProtoIP;
+    Uint32       numProtoTCP;
+    Uint32       numProtoUDP;
+    Uint32       numProtoSCTP;
+} ESockData;
+
+
+/* ----------------------------------------------------------------------
+ *  F o r w a r d s
+ * ----------------------------------------------------------------------
+ */
+
+
+extern char* erl_errno_id(int error); /* THIS IS JUST TEMPORARY??? */
+
+
+/* All the nif "callback" functions for the socket API has
+ * the exact same API:
+ *
+ * nif_<funcname>(ErlNifEnv*         env,
+ *                int                argc,
+ *                const ERL_NIF_TERM argv[]);
+ *
+ * So, to simplify, use some macro magic to define those.
+ *
+ * These are the functions making up the "official" API.
+ * Basically, these functions does some preliminary checks and argument
+ * extractions and then call the functions called 'n<funcname>', which 
+ * does the actual work. Except for the info function.
+ *
+ * nif_info
+ * nif_command
+ * nif_supports
+ * nif_open
+ * nif_bind
+ * nif_connect
+ * nif_listen
+ * nif_accept
+ * nif_send
+ * nif_sendto
+ * nif_sendmsg
+ * nif_recv
+ * nif_recvfrom
+ * nif_recvmsg
+ * nif_close
+ * nif_shutdown
+ * nif_setopt
+ * nif_getopt
+ * nif_sockname
+ * nif_peername
+ * nif_finalize_connection
+ * nif_finalize_close
+ * nif_cancel
+ */
+
+#define ESOCK_NIF_FUNCS                             \
+    ESOCK_NIF_FUNC_DEF(info);                       \
+    ESOCK_NIF_FUNC_DEF(command);                    \
+    ESOCK_NIF_FUNC_DEF(supports);                   \
+    ESOCK_NIF_FUNC_DEF(open);                       \
+    ESOCK_NIF_FUNC_DEF(bind);                       \
+    ESOCK_NIF_FUNC_DEF(connect);                    \
+    ESOCK_NIF_FUNC_DEF(listen);                     \
+    ESOCK_NIF_FUNC_DEF(accept);                     \
+    ESOCK_NIF_FUNC_DEF(send);                       \
+    ESOCK_NIF_FUNC_DEF(sendto);                     \
+    ESOCK_NIF_FUNC_DEF(sendmsg);                    \
+    ESOCK_NIF_FUNC_DEF(recv);                       \
+    ESOCK_NIF_FUNC_DEF(recvfrom);                   \
+    ESOCK_NIF_FUNC_DEF(recvmsg);                    \
+    ESOCK_NIF_FUNC_DEF(close);                      \
+    ESOCK_NIF_FUNC_DEF(shutdown);                   \
+    ESOCK_NIF_FUNC_DEF(setopt);                     \
+    ESOCK_NIF_FUNC_DEF(getopt);                     \
+    ESOCK_NIF_FUNC_DEF(sockname);                   \
+    ESOCK_NIF_FUNC_DEF(peername);                   \
+    ESOCK_NIF_FUNC_DEF(finalize_connection);        \
+    ESOCK_NIF_FUNC_DEF(finalize_close);             \
+    ESOCK_NIF_FUNC_DEF(cancel);
+
+#define ESOCK_NIF_FUNC_DEF(F)                              \
+    static ERL_NIF_TERM nif_##F(ErlNifEnv*         env,    \
+                                int                argc,   \
+                                const ERL_NIF_TERM argv[]);
+ESOCK_NIF_FUNCS
+#undef ESOCK_NIF_FUNC_DEF
+
+
+#if !defined(__WIN32__)
+
+/* And here comes the functions that does the actual work (for the most part) */
+
+static BOOLEAN_T ecommand2command(ErlNifEnv*    env,
+                                  ERL_NIF_TERM  ecommand,
+                                  Uint16*       command,
+                                  ERL_NIF_TERM* edata);
+static ERL_NIF_TERM esock_command(ErlNifEnv*   env,
+                                  Uint16       cmd,
+                                  ERL_NIF_TERM ecdata);
+static ERL_NIF_TERM esock_command_debug(ErlNifEnv* env, ERL_NIF_TERM ecdata);
+
+static ERL_NIF_TERM esock_global_info(ErlNifEnv* env);
+static ERL_NIF_TERM esock_socket_info(ErlNifEnv*       env,
+                                      ESockDescriptor* descP);
+static ERL_NIF_TERM esock_socket_info_counters(ErlNifEnv*       env,
+                                               ESockDescriptor* descP);
+#define ESOCK_SOCKET_INFO_REQ_FUNCS              \
+    ESOCK_SOCKET_INFO_REQ_FUNC_DEF(readers);     \
+    ESOCK_SOCKET_INFO_REQ_FUNC_DEF(writers);     \
+    ESOCK_SOCKET_INFO_REQ_FUNC_DEF(acceptors);
+
+#define ESOCK_SOCKET_INFO_REQ_FUNC_DEF(F)                               \
+    static ERL_NIF_TERM esock_socket_info_##F(ErlNifEnv*         env,   \
+                                              ESockDescriptor*   descP);
+ESOCK_SOCKET_INFO_REQ_FUNCS
+#undef ESOCK_SOCKET_INFO_REQ_FUNC_DEF
+
+static ERL_NIF_TERM socket_info_reqs(ErlNifEnv*         env,
+                                     ESockDescriptor*   descP,
+                                     ErlNifMutex*       mtx,
+                                     ESockRequestor*    crp,
+                                     ESockRequestQueue* q);
+
+static ERL_NIF_TERM esock_supports(ErlNifEnv* env, int key);
+static ERL_NIF_TERM esock_supports_options(ErlNifEnv* env);
+static ERL_NIF_TERM esock_supports_options_socket(ErlNifEnv* env);
+static ERL_NIF_TERM esock_supports_options_ip(ErlNifEnv* env);
+static ERL_NIF_TERM esock_supports_options_ipv6(ErlNifEnv* env);
+static ERL_NIF_TERM esock_supports_options_tcp(ErlNifEnv* env);
+static ERL_NIF_TERM esock_supports_options_udp(ErlNifEnv* env);
+static ERL_NIF_TERM esock_supports_options_sctp(ErlNifEnv* env);
+static ERL_NIF_TERM esock_supports_sctp(ErlNifEnv* env);
+static ERL_NIF_TERM esock_supports_ipv6(ErlNifEnv* env);
+static ERL_NIF_TERM esock_supports_local(ErlNifEnv* env);
+
+static ERL_NIF_TERM esock_open(ErlNifEnv* env,
+                          int        domain,
+                          int        type,
+                          int        protocol,
+                          char*      netns);
+static BOOLEAN_T esock_open_which_protocol(SOCKET sock, int* proto);
+
+static ERL_NIF_TERM esock_bind(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               ESockAddress*    sockAddrP,
+                               unsigned int     addrLen);
+static ERL_NIF_TERM esock_connect(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  ERL_NIF_TERM     sockRef);
+static ERL_NIF_TERM esock_listen(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 int              backlog);
+static ERL_NIF_TERM esock_accept(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 ERL_NIF_TERM     sockRef,
+                                 ERL_NIF_TERM     ref);
+static ERL_NIF_TERM esock_accept_listening(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     sockRef,
+                                           ERL_NIF_TERM     ref);
+static ERL_NIF_TERM esock_accept_listening_error(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     sockRef,
+                                                 ERL_NIF_TERM     accRef,
+                                                 ErlNifPid        caller,
+                                                 int              save_errno);
+static ERL_NIF_TERM esock_accept_listening_accept(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  SOCKET           accSock,
+                                                  ErlNifPid        caller,
+                                                  ESockAddress*    remote);
+static ERL_NIF_TERM esock_accept_accepting(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     sockRef,
+                                           ERL_NIF_TERM     ref);
+static ERL_NIF_TERM esock_accept_accepting_current(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     sockRef,
+                                                   ERL_NIF_TERM     ref);
+static ERL_NIF_TERM esock_accept_accepting_current_accept(ErlNifEnv*       env,
+                                                          ESockDescriptor* descP,
+                                                          ERL_NIF_TERM     sockRef,
+                                                          SOCKET           accSock,
+                                                          ESockAddress*    remote);
+static ERL_NIF_TERM esock_accept_accepting_current_error(ErlNifEnv*       env,
+                                                         ESockDescriptor* descP,
+                                                         ERL_NIF_TERM     sockRef,
+                                                         ERL_NIF_TERM     opRef,
+                                                         int              save_errno);
+static ERL_NIF_TERM esock_accept_accepting_other(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     ref,
+                                                 ErlNifPid        caller);
+static ERL_NIF_TERM esock_accept_busy_retry(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     sockRef,
+                                            ERL_NIF_TERM     accRef,
+                                            ErlNifPid*       pid,
+                                            unsigned int     nextState);
+static BOOLEAN_T esock_accept_accepted(ErlNifEnv*       env,
+                                       ESockDescriptor* descP,
+                                       SOCKET           accSock,
+                                       ErlNifPid        pid,
+                                       ESockAddress*    remote,
+                                       ERL_NIF_TERM*    result);
+static ERL_NIF_TERM esock_send(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               ERL_NIF_TERM     sockRef,
+                               ERL_NIF_TERM     sendRef,
+                               ErlNifBinary*    dataP,
+                               int              flags);
+static ERL_NIF_TERM esock_sendto(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 ERL_NIF_TERM     sockRef,
+                                 ERL_NIF_TERM     sendRef,
+                                 ErlNifBinary*    dataP,
+                                 int              flags,
+                                 ESockAddress*    toAddrP,
+                                 unsigned int     toAddrLen);
+static ERL_NIF_TERM esock_sendmsg(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  ERL_NIF_TERM     sockRef,
+                                  ERL_NIF_TERM     sendRef,
+                                  ERL_NIF_TERM     eMsgHdr,
+                                  int              flags);
+static ERL_NIF_TERM esock_recv(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               ERL_NIF_TERM     sendRef,
+                               ERL_NIF_TERM     recvRef,
+                               int              len,
+                               int              flags);
+static ERL_NIF_TERM esock_recvfrom(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   ERL_NIF_TERM     sockRef,
+                                   ERL_NIF_TERM     recvRef,
+                                   Uint16           bufSz,
+                                   int              flags);
+static ERL_NIF_TERM esock_recvmsg(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  ERL_NIF_TERM     sockRef,
+                                  ERL_NIF_TERM     recvRef,
+                                  Uint16           bufLen,
+                                  Uint16           ctrlLen,
+                                  int              flags);
+static ERL_NIF_TERM esock_close(ErlNifEnv*       env,
+                                ESockDescriptor* descP);
+static BOOLEAN_T esock_close_check(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   ERL_NIF_TERM*    reason);
+static ERL_NIF_TERM esock_close_do(ErlNifEnv*       env,
+                                   ESockDescriptor* descP);
+static ERL_NIF_TERM esock_shutdown(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   int              how);
+static ERL_NIF_TERM esock_setopt(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 BOOLEAN_T        isEncoded,
+                                 BOOLEAN_T        isOTP,
+                                 int              level,
+                                 int              eOpt,
+                                 ERL_NIF_TERM     eVal);
+
+/* Set OTP level options */
+static ERL_NIF_TERM esock_setopt_otp(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     int              eOpt,
+                                     ERL_NIF_TERM     eVal);
+/* *** esock_setopt_otp_debug      ***
+ * *** esock_setopt_otp_iow        ***
+ * *** esock_setopt_otp_ctrl_proc  ***
+ * *** esock_setopt_otp_rcvbuf     ***
+ * *** esock_setopt_otp_rcvctrlbuf ***
+ * *** esock_setopt_otp_sndctrlbuf ***
+ */
+#define ESOCK_SETOPT_OTP_FUNCS             \
+    ESOCK_SETOPT_OTP_FUNC_DEF(debug);      \
+    ESOCK_SETOPT_OTP_FUNC_DEF(iow);        \
+    ESOCK_SETOPT_OTP_FUNC_DEF(ctrl_proc);  \
+    ESOCK_SETOPT_OTP_FUNC_DEF(rcvbuf);     \
+    ESOCK_SETOPT_OTP_FUNC_DEF(rcvctrlbuf); \
+    ESOCK_SETOPT_OTP_FUNC_DEF(sndctrlbuf);
+#define ESOCK_SETOPT_OTP_FUNC_DEF(F)                                 \
+    static ERL_NIF_TERM esock_setopt_otp_##F(ErlNifEnv*       env,   \
+                                             ESockDescriptor* descP, \
+                                             ERL_NIF_TERM     eVal)
+ESOCK_SETOPT_OTP_FUNCS
+#undef ESOCK_SETOPT_OTP_FUNC_DEF
+
+/* Set native options */
+static ERL_NIF_TERM esock_setopt_native(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        int              level,
+                                        int              eOpt,
+                                        ERL_NIF_TERM     eVal);
+static ERL_NIF_TERM esock_setopt_level(ErlNifEnv*       env,
+                                       ESockDescriptor* descP,
+                                       int              level,
+                                       int              eOpt,
+                                       ERL_NIF_TERM     eVal);
+static ERL_NIF_TERM esock_setopt_lvl_socket(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            int              eOpt,
+                                            ERL_NIF_TERM     eVal);
+
+
+/* *** Handling set of socket options for level = socket *** */
+
+#if defined(SO_BINDTODEVICE)
+static ERL_NIF_TERM esock_setopt_lvl_sock_bindtodevice(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP,
+                                                       ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_BROADCAST)
+static ERL_NIF_TERM esock_setopt_lvl_sock_broadcast(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_DEBUG)
+static ERL_NIF_TERM esock_setopt_lvl_sock_debug(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_DONTROUTE)
+static ERL_NIF_TERM esock_setopt_lvl_sock_dontroute(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_KEEPALIVE)
+static ERL_NIF_TERM esock_setopt_lvl_sock_keepalive(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_LINGER)
+static ERL_NIF_TERM esock_setopt_lvl_sock_linger(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_OOBINLINE)
+static ERL_NIF_TERM esock_setopt_lvl_sock_oobinline(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_PEEK_OFF)
+static ERL_NIF_TERM esock_setopt_lvl_sock_peek_off(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_PRIORITY)
+static ERL_NIF_TERM esock_setopt_lvl_sock_priority(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_RCVBUF)
+static ERL_NIF_TERM esock_setopt_lvl_sock_rcvbuf(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_RCVLOWAT)
+static ERL_NIF_TERM esock_setopt_lvl_sock_rcvlowat(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_RCVTIMEO)
+static ERL_NIF_TERM esock_setopt_lvl_sock_rcvtimeo(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_REUSEADDR)
+static ERL_NIF_TERM esock_setopt_lvl_sock_reuseaddr(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_REUSEPORT)
+static ERL_NIF_TERM esock_setopt_lvl_sock_reuseport(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_SNDBUF)
+static ERL_NIF_TERM esock_setopt_lvl_sock_sndbuf(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_SNDLOWAT)
+static ERL_NIF_TERM esock_setopt_lvl_sock_sndlowat(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_SNDTIMEO)
+static ERL_NIF_TERM esock_setopt_lvl_sock_sndtimeo(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal);
+#endif
+#if defined(SO_TIMESTAMP)
+static ERL_NIF_TERM esock_setopt_lvl_sock_timestamp(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+static ERL_NIF_TERM esock_setopt_lvl_ip(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        int              eOpt,
+                                        ERL_NIF_TERM     eVal);
+
+/* *** Handling set of socket options for level = ip *** */
+#if defined(IP_ADD_MEMBERSHIP)
+static ERL_NIF_TERM esock_setopt_lvl_ip_add_membership(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP,
+                                                       ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_ADD_SOURCE_MEMBERSHIP)
+static ERL_NIF_TERM esock_setopt_lvl_ip_add_source_membership(ErlNifEnv*       env,
+                                                              ESockDescriptor* descP,
+                                                              ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_BLOCK_SOURCE)
+static ERL_NIF_TERM esock_setopt_lvl_ip_block_source(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP,
+                                                     ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_DROP_MEMBERSHIP)
+static ERL_NIF_TERM esock_setopt_lvl_ip_drop_membership(ErlNifEnv*       env,
+                                                        ESockDescriptor* descP,
+                                                        ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_DROP_SOURCE_MEMBERSHIP)
+static ERL_NIF_TERM esock_setopt_lvl_ip_drop_source_membership(ErlNifEnv*       env,
+                                                               ESockDescriptor* descP,
+                                                               ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_FREEBIND)
+static ERL_NIF_TERM esock_setopt_lvl_ip_freebind(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_HDRINCL)
+static ERL_NIF_TERM esock_setopt_lvl_ip_hdrincl(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_MINTTL)
+static ERL_NIF_TERM esock_setopt_lvl_ip_minttl(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_MSFILTER) && defined(IP_MSFILTER_SIZE)
+static ERL_NIF_TERM esock_setopt_lvl_ip_msfilter(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+static BOOLEAN_T decode_ip_msfilter_mode(ErlNifEnv*   env,
+                                         ERL_NIF_TERM eVal,
+                                         Uint32*      mode);
+static ERL_NIF_TERM esock_setopt_lvl_ip_msfilter_set(ErlNifEnv*          env,
+                                                     SOCKET              sock,
+                                                     struct ip_msfilter* msfP,
+                                                     SOCKLEN_T           optLen);
+#endif
+#if defined(IP_MTU_DISCOVER)
+static ERL_NIF_TERM esock_setopt_lvl_ip_mtu_discover(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP,
+                                                     ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_MULTICAST_ALL)
+static ERL_NIF_TERM esock_setopt_lvl_ip_multicast_all(ErlNifEnv*       env,
+                                                      ESockDescriptor* descP,
+                                                      ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_MULTICAST_IF)
+static ERL_NIF_TERM esock_setopt_lvl_ip_multicast_if(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP,
+                                                     ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_MULTICAST_LOOP)
+static ERL_NIF_TERM esock_setopt_lvl_ip_multicast_loop(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP,
+                                                       ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_MULTICAST_TTL)
+static ERL_NIF_TERM esock_setopt_lvl_ip_multicast_ttl(ErlNifEnv*       env,
+                                                      ESockDescriptor* descP,
+                                                      ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_NODEFRAG)
+static ERL_NIF_TERM esock_setopt_lvl_ip_nodefrag(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_PKTINFO)
+static ERL_NIF_TERM esock_setopt_lvl_ip_pktinfo(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_RECVDSTADDR)
+static ERL_NIF_TERM esock_setopt_lvl_ip_recvdstaddr(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_RECVERR)
+static ERL_NIF_TERM esock_setopt_lvl_ip_recverr(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_RECVIF)
+static ERL_NIF_TERM esock_setopt_lvl_ip_recvif(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_RECVOPTS)
+static ERL_NIF_TERM esock_setopt_lvl_ip_recvopts(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_RECVORIGDSTADDR)
+static ERL_NIF_TERM esock_setopt_lvl_ip_recvorigdstaddr(ErlNifEnv*       env,
+                                                        ESockDescriptor* descP,
+                                                        ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_RECVTOS)
+static ERL_NIF_TERM esock_setopt_lvl_ip_recvtos(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_RECVTTL)
+static ERL_NIF_TERM esock_setopt_lvl_ip_recvttl(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_RETOPTS)
+static ERL_NIF_TERM esock_setopt_lvl_ip_retopts(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_ROUTER_ALERT)
+static ERL_NIF_TERM esock_setopt_lvl_ip_router_alert(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP,
+                                                     ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_SENDSRCADDR)
+static ERL_NIF_TERM esock_setopt_lvl_ip_sendsrcaddr(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_TOS)
+static ERL_NIF_TERM esock_setopt_lvl_ip_tos(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_TRANSPARENT)
+static ERL_NIF_TERM esock_setopt_lvl_ip_transparent(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_TTL)
+static ERL_NIF_TERM esock_setopt_lvl_ip_ttl(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal);
+#endif
+#if defined(IP_UNBLOCK_SOURCE)
+static ERL_NIF_TERM esock_setopt_lvl_ip_unblock_source(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP,
+                                                       ERL_NIF_TERM     eVal);
+#endif
+
+#if defined(IP_DROP_MEMBERSHIP) || defined(IP_ADD_MEMBERSHIP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_update_membership(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal,
+                                                   int              opt);
+#endif
+#if defined(IP_ADD_SOURCE_MEMBERSHIP) || defined(IP_DROP_SOURCE_MEMBERSHIP) || defined(IP_BLOCK_SOURCE) || defined(IP_UNBLOCK_SOURCE)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_update_source(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               ERL_NIF_TERM     eVal,
+                                               int              opt);
+#endif
+
+
+/* *** Handling set of socket options for level = ipv6 *** */
+#if defined(HAVE_IPV6)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          int              eOpt,
+                                          ERL_NIF_TERM     eVal);
+#if defined(IPV6_ADDRFORM)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_addrform(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_ADD_MEMBERSHIP)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_add_membership(ErlNifEnv*       env,
+                                                         ESockDescriptor* descP,
+                                                         ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_AUTHHDR)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_authhdr(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_DROP_MEMBERSHIP)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_drop_membership(ErlNifEnv*       env,
+                                                          ESockDescriptor* descP,
+                                                          ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_DSTOPTS)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_dstopts(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_FLOWINFO)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_flowinfo(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_HOPLIMIT)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_hoplimit(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_HOPOPTS)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_hopopts(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_MTU)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_mtu(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_MTU_DISCOVER)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_mtu_discover(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP,
+                                                       ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_MULTICAST_HOPS)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_multicast_hops(ErlNifEnv*       env,
+                                                         ESockDescriptor* descP,
+                                                         ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_MULTICAST_IF)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_multicast_if(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP,
+                                                       ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_MULTICAST_LOOP)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_multicast_loop(ErlNifEnv*       env,
+                                                         ESockDescriptor* descP,
+                                                         ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_RECVERR)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_recverr(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_recvpktinfo(ErlNifEnv*       env,
+                                                      ESockDescriptor* descP,
+                                                      ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_ROUTER_ALERT)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_router_alert(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP,
+                                                       ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_RTHDR)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_rthdr(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_UNICAST_HOPS)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_unicast_hops(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP,
+                                                       ERL_NIF_TERM     eVal);
+#endif
+#if defined(IPV6_V6ONLY)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_v6only(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+
+#if defined(IPV6_ADD_MEMBERSHIP) || defined(IPV6_DROP_MEMBERSHIP)
+static ERL_NIF_TERM esock_setopt_lvl_ipv6_update_membership(ErlNifEnv*       env,
+                                                            ESockDescriptor* descP,
+                                                            ERL_NIF_TERM     eVal,
+                                                            int              opt);
+#endif
+
+#endif // defined(HAVE_IPV6)
+static ERL_NIF_TERM esock_setopt_lvl_tcp(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              eOpt,
+                                         ERL_NIF_TERM     eVal);
+#if defined(TCP_CONGESTION)
+static ERL_NIF_TERM esock_setopt_lvl_tcp_congestion(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(TCP_MAXSEG)
+static ERL_NIF_TERM esock_setopt_lvl_tcp_maxseg(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal);
+#endif
+#if defined(TCP_NODELAY)
+static ERL_NIF_TERM esock_setopt_lvl_tcp_nodelay(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+static ERL_NIF_TERM esock_setopt_lvl_udp(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              eOpt,
+                                         ERL_NIF_TERM     eVal);
+#if defined(UDP_CORK)
+static ERL_NIF_TERM esock_setopt_lvl_udp_cork(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     eVal);
+#endif
+#if defined(HAVE_SCTP)
+static ERL_NIF_TERM esock_setopt_lvl_sctp(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          int              eOpt,
+                                          ERL_NIF_TERM     eVal);
+#if defined(SCTP_ASSOCINFO)
+static ERL_NIF_TERM esock_setopt_lvl_sctp_associnfo(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(SCTP_AUTOCLOSE)
+static ERL_NIF_TERM esock_setopt_lvl_sctp_autoclose(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP,
+                                                    ERL_NIF_TERM     eVal);
+#endif
+#if defined(SCTP_DISABLE_FRAGMENTS)
+static ERL_NIF_TERM esock_setopt_lvl_sctp_disable_fragments(ErlNifEnv*       env,
+                                                            ESockDescriptor* descP,
+                                                            ERL_NIF_TERM     eVal);
+#endif
+#if defined(SCTP_EVENTS)
+static ERL_NIF_TERM esock_setopt_lvl_sctp_events(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+#if defined(SCTP_INITMSG)
+static ERL_NIF_TERM esock_setopt_lvl_sctp_initmsg(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal);
+#endif
+#if defined(SCTP_MAXSEG)
+static ERL_NIF_TERM esock_setopt_lvl_sctp_maxseg(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal);
+#endif
+#if defined(SCTP_NODELAY)
+static ERL_NIF_TERM esock_setopt_lvl_sctp_nodelay(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal);
+#endif
+#if defined(SCTP_RTOINFO)
+static ERL_NIF_TERM esock_setopt_lvl_sctp_rtoinfo(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal);
+#endif
+#endif // defined(HAVE_SCTP)
+
+static ERL_NIF_TERM esock_getopt(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 BOOLEAN_T        isEncoded,
+                                 BOOLEAN_T        isOTP,
+                                 int              level,
+                                 ERL_NIF_TERM     eOpt);
+
+static ERL_NIF_TERM esock_getopt_otp(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     int              eOpt);
+/* *** esock_getopt_otp_debug      ***
+ * *** esock_getopt_otp_iow        ***
+ * *** esock_getopt_otp_ctrl_proc  ***
+ * *** esock_getopt_otp_rcvbuf     ***
+ * *** esock_getopt_otp_rcvctrlbuf ***
+ * *** esock_getopt_otp_sndctrlbuf ***
+ * *** esock_getopt_otp_fd         ***
+ * *** esock_getopt_otp_domain     ***
+ * *** esock_getopt_otp_type       ***
+ * *** esock_getopt_otp_protocol   ***
+ */
+#define ESOCK_GETOPT_OTP_FUNCS             \
+    ESOCK_GETOPT_OTP_FUNC_DEF(debug);      \
+    ESOCK_GETOPT_OTP_FUNC_DEF(iow);        \
+    ESOCK_GETOPT_OTP_FUNC_DEF(ctrl_proc);  \
+    ESOCK_GETOPT_OTP_FUNC_DEF(rcvbuf);     \
+    ESOCK_GETOPT_OTP_FUNC_DEF(rcvctrlbuf); \
+    ESOCK_GETOPT_OTP_FUNC_DEF(sndctrlbuf); \
+    ESOCK_GETOPT_OTP_FUNC_DEF(fd);         \
+    ESOCK_GETOPT_OTP_FUNC_DEF(domain);     \
+    ESOCK_GETOPT_OTP_FUNC_DEF(type);       \
+    ESOCK_GETOPT_OTP_FUNC_DEF(protocol);
+#define ESOCK_GETOPT_OTP_FUNC_DEF(F)                               \
+    static ERL_NIF_TERM esock_getopt_otp_##F(ErlNifEnv*        env, \
+                                             ESockDescriptor* descP)
+ESOCK_GETOPT_OTP_FUNCS
+#undef ESOCK_GETOPT_OTP_FUNC_DEF
+
+static ERL_NIF_TERM esock_getopt_native(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        int              level,
+                                        ERL_NIF_TERM     eOpt);
+static ERL_NIF_TERM esock_getopt_native_unspec(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               int              level,
+                                               int              opt,
+                                               SOCKOPTLEN_T     valueSz);
+static ERL_NIF_TERM esock_getopt_level(ErlNifEnv*       env,
+                                       ESockDescriptor* descP,
+                                       int              level,
+                                       int              eOpt);
+static ERL_NIF_TERM esock_getopt_lvl_socket(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            int              eOpt);
+#if defined(SO_ACCEPTCONN)
+static ERL_NIF_TERM esock_getopt_lvl_sock_acceptconn(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP);
+#endif
+#if defined(SO_BINDTODEVICE)
+static ERL_NIF_TERM esock_getopt_lvl_sock_bindtodevice(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP);
+#endif
+#if defined(SO_BROADCAST)
+static ERL_NIF_TERM esock_getopt_lvl_sock_broadcast(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(SO_DEBUG)
+static ERL_NIF_TERM esock_getopt_lvl_sock_debug(ErlNifEnv*       env,
+                                                ESockDescriptor* descP);
+#endif
+#if defined(SO_DOMAIN)
+static ERL_NIF_TERM esock_getopt_lvl_sock_domain(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+#if defined(SO_DONTROUTE)
+static ERL_NIF_TERM esock_getopt_lvl_sock_dontroute(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(SO_KEEPALIVE)
+static ERL_NIF_TERM esock_getopt_lvl_sock_keepalive(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(SO_LINGER)
+static ERL_NIF_TERM esock_getopt_lvl_sock_linger(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+#if defined(SO_OOBINLINE)
+static ERL_NIF_TERM esock_getopt_lvl_sock_oobinline(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(SO_PEEK_OFF)
+static ERL_NIF_TERM esock_getopt_lvl_sock_peek_off(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP);
+#endif
+#if defined(SO_PRIORITY)
+static ERL_NIF_TERM esock_getopt_lvl_sock_priority(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP);
+#endif
+#if defined(SO_PROTOCOL)
+static ERL_NIF_TERM esock_getopt_lvl_sock_protocol(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP);
+#endif
+#if defined(SO_RCVBUF)
+static ERL_NIF_TERM esock_getopt_lvl_sock_rcvbuf(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+#if defined(SO_RCVLOWAT)
+static ERL_NIF_TERM esock_getopt_lvl_sock_rcvlowat(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP);
+#endif
+#if defined(SO_RCVTIMEO)
+static ERL_NIF_TERM esock_getopt_lvl_sock_rcvtimeo(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP);
+#endif
+#if defined(SO_REUSEADDR)
+static ERL_NIF_TERM esock_getopt_lvl_sock_reuseaddr(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(SO_REUSEPORT)
+static ERL_NIF_TERM esock_getopt_lvl_sock_reuseport(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(SO_SNDBUF)
+static ERL_NIF_TERM esock_getopt_lvl_sock_sndbuf(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+#if defined(SO_SNDLOWAT)
+static ERL_NIF_TERM esock_getopt_lvl_sock_sndlowat(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP);
+#endif
+#if defined(SO_SNDTIMEO)
+static ERL_NIF_TERM esock_getopt_lvl_sock_sndtimeo(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP);
+#endif
+#if defined(SO_TIMESTAMP)
+static ERL_NIF_TERM esock_getopt_lvl_sock_timestamp(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(SO_TYPE)
+static ERL_NIF_TERM esock_getopt_lvl_sock_type(ErlNifEnv*       env,
+                                               ESockDescriptor* descP);
+#endif
+static ERL_NIF_TERM esock_getopt_lvl_ip(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        int              eOpt);
+#if defined(IP_FREEBIND)
+static ERL_NIF_TERM esock_getopt_lvl_ip_freebind(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+#if defined(IP_HDRINCL)
+static ERL_NIF_TERM esock_getopt_lvl_ip_hdrincl(ErlNifEnv*       env,
+                                                ESockDescriptor* descP);
+#endif
+#if defined(IP_MINTTL)
+static ERL_NIF_TERM esock_getopt_lvl_ip_minttl(ErlNifEnv*       env,
+                                               ESockDescriptor* descP);
+#endif
+#if defined(IP_MTU)
+static ERL_NIF_TERM esock_getopt_lvl_ip_mtu(ErlNifEnv*       env,
+                                            ESockDescriptor* descP);
+#endif
+#if defined(IP_MTU_DISCOVER)
+static ERL_NIF_TERM esock_getopt_lvl_ip_mtu_discover(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP);
+#endif
+#if defined(IP_MULTICAST_ALL)
+static ERL_NIF_TERM esock_getopt_lvl_ip_multicast_all(ErlNifEnv*       env,
+                                                      ESockDescriptor* descP);
+#endif
+#if defined(IP_MULTICAST_IF)
+static ERL_NIF_TERM esock_getopt_lvl_ip_multicast_if(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP);
+#endif
+#if defined(IP_MULTICAST_LOOP)
+static ERL_NIF_TERM esock_getopt_lvl_ip_multicast_loop(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP);
+#endif
+#if defined(IP_MULTICAST_TTL)
+static ERL_NIF_TERM esock_getopt_lvl_ip_multicast_ttl(ErlNifEnv*       env,
+                                                      ESockDescriptor* descP);
+#endif
+#if defined(IP_NODEFRAG)
+static ERL_NIF_TERM esock_getopt_lvl_ip_nodefrag(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+#if defined(IP_PKTINFO)
+static ERL_NIF_TERM esock_getopt_lvl_ip_pktinfo(ErlNifEnv*       env,
+                                                ESockDescriptor* descP);
+#endif
+#if defined(IP_RECVDSTADDR)
+static ERL_NIF_TERM esock_getopt_lvl_ip_recvdstaddr(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(IP_RECVERR)
+static ERL_NIF_TERM esock_getopt_lvl_ip_recverr(ErlNifEnv*       env,
+                                                ESockDescriptor* descP);
+#endif
+#if defined(IP_RECVIF)
+static ERL_NIF_TERM esock_getopt_lvl_ip_recvif(ErlNifEnv*       env,
+                                               ESockDescriptor* descP);
+#endif
+#if defined(IP_RECVOPTS)
+static ERL_NIF_TERM esock_getopt_lvl_ip_recvopts(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+#if defined(IP_RECVORIGDSTADDR)
+static ERL_NIF_TERM esock_getopt_lvl_ip_recvorigdstaddr(ErlNifEnv*       env,
+                                                        ESockDescriptor* descP);
+#endif
+#if defined(IP_RECVTOS)
+static ERL_NIF_TERM esock_getopt_lvl_ip_recvtos(ErlNifEnv*       env,
+                                                ESockDescriptor* descP);
+#endif
+#if defined(IP_RECVTTL)
+static ERL_NIF_TERM esock_getopt_lvl_ip_recvttl(ErlNifEnv*       env,
+                                                ESockDescriptor* descP);
+#endif
+#if defined(IP_RETOPTS)
+static ERL_NIF_TERM esock_getopt_lvl_ip_retopts(ErlNifEnv*       env,
+                                                ESockDescriptor* descP);
+#endif
+#if defined(IP_ROUTER_ALERT)
+static ERL_NIF_TERM esock_getopt_lvl_ip_router_alert(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP);
+#endif
+#if defined(IP_SENDSRCADDR)
+static ERL_NIF_TERM esock_getopt_lvl_ip_sendsrcaddr(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(IP_TOS)
+static ERL_NIF_TERM esock_getopt_lvl_ip_tos(ErlNifEnv*       env,
+                                            ESockDescriptor* descP);
+#endif
+#if defined(IP_TRANSPARENT)
+static ERL_NIF_TERM esock_getopt_lvl_ip_transparent(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(IP_TTL)
+static ERL_NIF_TERM esock_getopt_lvl_ip_ttl(ErlNifEnv*       env,
+                                            ESockDescriptor* descP);
+#endif
+#if defined(HAVE_IPV6)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          int              eOpt);
+#if defined(IPV6_AUTHHDR)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_authhdr(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP);
+#endif
+#if defined(IPV6_DSTOPTS)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_dstopts(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP);
+#endif
+#if defined(IPV6_FLOWINFO)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_flowinfo(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP);
+#endif
+#if defined(IPV6_HOPLIMIT)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_hoplimit(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP);
+#endif
+#if defined(IPV6_HOPOPTS)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_hopopts(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP);
+#endif
+#if defined(IPV6_MTU)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_mtu(ErlNifEnv*       env,
+                                              ESockDescriptor* descP);
+#endif
+#if defined(IPV6_MTU_DISCOVER)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_mtu_discover(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP);
+#endif
+#if defined(IPV6_MULTICAST_HOPS)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_multicast_hops(ErlNifEnv*       env,
+                                                         ESockDescriptor* descP);
+#endif
+#if defined(IPV6_MULTICAST_IF)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_multicast_if(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP);
+#endif
+#if defined(IPV6_MULTICAST_LOOP)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_multicast_loop(ErlNifEnv*       env,
+                                                         ESockDescriptor* descP);
+#endif
+#if defined(IPV6_RECVERR)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_recverr(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP);
+#endif
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_recvpktinfo(ErlNifEnv*       env,
+                                                      ESockDescriptor* descP);
+#endif
+#if defined(IPV6_ROUTER_ALERT)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_router_alert(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP);
+#endif
+#if defined(IPV6_RTHDR)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_rthdr(ErlNifEnv*       env,
+                                                ESockDescriptor* descP);
+#endif
+#if defined(IPV6_UNICAST_HOPS)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_unicast_hops(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP);
+#endif
+#if defined(IPV6_V6ONLY)
+static ERL_NIF_TERM esock_getopt_lvl_ipv6_v6only(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+
+#endif // defined(HAVE_IPV6)
+
+static ERL_NIF_TERM esock_getopt_lvl_tcp(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              eOpt);
+#if defined(TCP_CONGESTION)
+static ERL_NIF_TERM esock_getopt_lvl_tcp_congestion(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(TCP_MAXSEG)
+static ERL_NIF_TERM esock_getopt_lvl_tcp_maxseg(ErlNifEnv*       env,
+                                                ESockDescriptor* descP);
+#endif
+#if defined(TCP_NODELAY)
+static ERL_NIF_TERM esock_getopt_lvl_tcp_nodelay(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+static ERL_NIF_TERM esock_getopt_lvl_udp(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              eOpt);
+#if defined(UDP_CORK)
+static ERL_NIF_TERM esock_getopt_lvl_udp_cork(ErlNifEnv*       env,
+                                              ESockDescriptor* descP);
+#endif
+#if defined(HAVE_SCTP)
+static ERL_NIF_TERM esock_getopt_lvl_sctp(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          int              eOpt);
+#if defined(SCTP_ASSOCINFO)
+static ERL_NIF_TERM esock_getopt_lvl_sctp_associnfo(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(SCTP_AUTOCLOSE)
+static ERL_NIF_TERM esock_getopt_lvl_sctp_autoclose(ErlNifEnv*       env,
+                                                    ESockDescriptor* descP);
+#endif
+#if defined(SCTP_DISABLE_FRAGMENTS)
+static ERL_NIF_TERM esock_getopt_lvl_sctp_disable_fragments(ErlNifEnv*       env,
+                                                            ESockDescriptor* descP);
+#endif
+#if defined(SCTP_MAXSEG)
+static ERL_NIF_TERM esock_getopt_lvl_sctp_maxseg(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP);
+#endif
+#if defined(SCTP_INITMSG)
+static ERL_NIF_TERM esock_getopt_lvl_sctp_initmsg(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP);
+#endif
+#if defined(SCTP_NODELAY)
+static ERL_NIF_TERM esock_getopt_lvl_sctp_nodelay(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP);
+#endif
+#if defined(SCTP_RTOINFO)
+static ERL_NIF_TERM esock_getopt_lvl_sctp_rtoinfo(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP);
+#endif
+#endif // defined(HAVE_SCTP)
+static ERL_NIF_TERM esock_sockname(ErlNifEnv*       env,
+                                   ESockDescriptor* descP);
+static ERL_NIF_TERM esock_peername(ErlNifEnv*       env,
+                                   ESockDescriptor* descP);
+static ERL_NIF_TERM esock_cancel(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 ERL_NIF_TERM     op,
+                                 ERL_NIF_TERM     sockRef,
+                                 ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_connect(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_accept(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        ERL_NIF_TERM     sockRef,
+                                        ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_accept_current(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     sockRef);
+static ERL_NIF_TERM esock_cancel_accept_waiting(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_send(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      ERL_NIF_TERM     sockRef,
+                                      ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_send_current(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     sockRef);
+static ERL_NIF_TERM esock_cancel_send_waiting(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_recv(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      ERL_NIF_TERM     sockRef,
+                                      ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_recv_current(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     sockRef);
+static ERL_NIF_TERM esock_cancel_recv_waiting(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_read_select(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_write_select(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     opRef);
+static ERL_NIF_TERM esock_cancel_mode_select(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     opRef,
+                                             int              smode,
+                                             int              rmode);
+
+#if defined(USE_SETOPT_STR_OPT)
+static ERL_NIF_TERM esock_setopt_str_opt(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              level,
+                                         int              opt,
+                                         int              max,
+                                         ERL_NIF_TERM     eVal);
+#endif
+static ERL_NIF_TERM esock_setopt_bool_opt(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          int              level,
+                                          int              opt,
+                                          ERL_NIF_TERM     eVal);
+static ERL_NIF_TERM esock_setopt_int_opt(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              level,
+                                         int              opt,
+                                         ERL_NIF_TERM     eVal);
+static ERL_NIF_TERM esock_setopt_timeval_opt(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             int              level,
+                                             int              opt,
+                                             ERL_NIF_TERM     eVal);
+
+#if defined(USE_GETOPT_STR_OPT)
+static ERL_NIF_TERM esock_getopt_str_opt(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              level,
+                                         int              opt,
+                                         int              max);
+#endif
+static ERL_NIF_TERM esock_getopt_bool_opt(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          int              level,
+                                          int              opt);
+static ERL_NIF_TERM esock_getopt_int_opt(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              level,
+                                         int              opt);
+static ERL_NIF_TERM esock_getopt_timeval_opt(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             int              level,
+                                             int              opt);
+
+static BOOLEAN_T send_check_writer(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   ERL_NIF_TERM     ref,
+                                   ERL_NIF_TERM*    checkResult);
+static ERL_NIF_TERM send_check_result(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      ssize_t          written,
+                                      ssize_t          dataSize,
+                                      int              saveErrno,
+                                      ERL_NIF_TERM     sockRef,
+                                      ERL_NIF_TERM     sendRef);
+static ERL_NIF_TERM send_check_ok(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  ssize_t          written,
+                                  ssize_t          dataSize,
+                                  ERL_NIF_TERM     sockRef);
+static ERL_NIF_TERM send_check_fail(ErlNifEnv*       env,
+                                    ESockDescriptor* descP,
+                                    int              saveErrno,
+                                    ERL_NIF_TERM     sockRef);
+static ERL_NIF_TERM send_check_retry(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     ssize_t          written,
+                                     ERL_NIF_TERM     sockRef,
+                                     ERL_NIF_TERM     sendRef);
+static BOOLEAN_T recv_check_reader(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   ERL_NIF_TERM     ref,
+                                   ERL_NIF_TERM*    checkResult);
+static char* recv_init_current_reader(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      ERL_NIF_TERM     ref);
+static ERL_NIF_TERM recv_update_current_reader(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               ERL_NIF_TERM     sockRef);
+static void recv_error_current_reader(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      ERL_NIF_TERM     sockRef,
+                                      ERL_NIF_TERM     reason);
+static ERL_NIF_TERM recv_check_result(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      int              read,
+                                      int              toRead,
+                                      int              saveErrno,
+                                      ErlNifBinary*    bufP,
+                                      ERL_NIF_TERM     sockRef,
+                                      ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recv_check_full(ErlNifEnv*       env,
+                                    ESockDescriptor* descP,
+                                    int              read,
+                                    int              toRead,
+                                    ErlNifBinary*    bufP,
+                                    ERL_NIF_TERM     sockRef,
+                                    ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recv_check_full_maybe_done(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               int              read,
+                                               int              toRead,
+                                               ErlNifBinary*    bufP,
+                                               ERL_NIF_TERM     sockRef,
+                                               ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recv_check_full_done(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              read,
+                                         ErlNifBinary*    bufP,
+                                         ERL_NIF_TERM     sockRef);
+static ERL_NIF_TERM recv_check_fail(ErlNifEnv*       env,
+                                    ESockDescriptor* descP,
+                                    int              saveErrno,
+                                    ErlNifBinary*    buf1P,
+                                    ErlNifBinary*    buf2P,
+                                    ERL_NIF_TERM     sockRef,
+                                    ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recv_check_fail_closed(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     sockRef,
+                                           ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recv_check_partial(ErlNifEnv*       env,
+                                       ESockDescriptor* descP,
+                                       int              read,
+                                       int              toRead,
+                                       ErlNifBinary*    bufP,
+                                       ERL_NIF_TERM     sockRef,
+                                       ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recv_check_partial_done(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            int              read,
+                                            ErlNifBinary*    bufP,
+                                            ERL_NIF_TERM     sockRef);
+static ERL_NIF_TERM recv_check_partial_part(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            int              read,
+                                            ErlNifBinary*    bufP,
+                                            ERL_NIF_TERM     sockRef,
+                                            ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recv_check_retry(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     ERL_NIF_TERM     sockRef,
+                                     ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recv_check_fail_gen(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        int              saveErrno,
+                                        ERL_NIF_TERM     sockRef);
+static ERL_NIF_TERM recvfrom_check_result(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          int              read,
+                                          int              saveErrno,
+                                          ErlNifBinary*    bufP,
+                                          ESockAddress*    fromAddrP,
+                                          unsigned int     fromAddrLen,
+                                          ERL_NIF_TERM     sockRef,
+                                          ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recvmsg_check_result(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         int              read,
+                                         int              saveErrno,
+                                         struct msghdr*   msgHdrP,
+                                         ErlNifBinary*    dataBufP,
+                                         ErlNifBinary*    ctrlBufP,
+                                         ERL_NIF_TERM     sockRef,
+                                         ERL_NIF_TERM     recvRef);
+static ERL_NIF_TERM recvmsg_check_msg(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      int              read,
+                                      struct msghdr*   msgHdrP,
+                                      ErlNifBinary*    dataBufP,
+                                      ErlNifBinary*    ctrlBufP,
+                                      ERL_NIF_TERM     sockRef);
+
+static ERL_NIF_TERM esock_finalize_connection(ErlNifEnv*       env,
+                                              ESockDescriptor* descP);
+static ERL_NIF_TERM esock_finalize_close(ErlNifEnv*       env,
+                                         ESockDescriptor* descP);
+
+extern char* encode_msghdr(ErlNifEnv*       env,
+                           ESockDescriptor* descP,
+                           int              read,
+                           struct msghdr*   msgHdrP,
+                           ErlNifBinary*    dataBufP,
+                           ErlNifBinary*    ctrlBufP,
+                           ERL_NIF_TERM*    eSockAddr);
+extern char* encode_cmsghdrs(ErlNifEnv*       env,
+                             ESockDescriptor* descP,
+                             ErlNifBinary*    cmsgBinP,
+                             struct msghdr*   msgHdrP,
+                             ERL_NIF_TERM*    eCMsgHdr);
+extern char* decode_cmsghdrs(ErlNifEnv*       env,
+                             ESockDescriptor* descP,
+                             ERL_NIF_TERM     eCMsgHdr,
+                             char*            cmsgHdrBufP,
+                             size_t           cmsgHdrBufLen,
+                             size_t*          cmsgHdrBufUsed);
+extern char* decode_cmsghdr(ErlNifEnv*       env,
+                            ESockDescriptor* descP,
+                            ERL_NIF_TERM     eCMsgHdr,
+                            char*            bufP,
+                            size_t           rem,
+                            size_t*          used);
+static char* encode_cmsghdr_level(ErlNifEnv*    env,
+                                  int           level,
+                                  ERL_NIF_TERM* eLevel);
+static char* decode_cmsghdr_level(ErlNifEnv*   env,
+                                  ERL_NIF_TERM eLevel,
+                                  int*         level);
+static char* encode_cmsghdr_type(ErlNifEnv*    env,
+                                 int           level,
+                                 int           type,
+                                 ERL_NIF_TERM* eType);
+static char* decode_cmsghdr_type(ErlNifEnv*   env,
+                                 int          level,
+                                 ERL_NIF_TERM eType,
+                                 int*         type);
+static char* encode_cmsghdr_data(ErlNifEnv*     env,
+                                 ERL_NIF_TERM   ctrlBuf,
+                                 int            level,
+                                 int            type,
+                                 unsigned char* dataP,
+                                 size_t         dataPos,
+                                 size_t         dataLen,
+                                 ERL_NIF_TERM*  eCMsgHdrData);
+static char* encode_cmsghdr_data_socket(ErlNifEnv*     env,
+                                        ERL_NIF_TERM   ctrlBuf,
+                                        int            type,
+                                        unsigned char* dataP,
+                                        size_t         dataPos,
+                                        size_t         dataLen,
+                                        ERL_NIF_TERM*  eCMsgHdrData);
+static char* encode_cmsghdr_data_ip(ErlNifEnv*     env,
+                                    ERL_NIF_TERM   ctrlBuf,
+                                    int            type,
+                                    unsigned char* dataP,
+                                    size_t         dataPos,
+                                    size_t         dataLen,
+                                    ERL_NIF_TERM*  eCMsgHdrData);
+#if defined(HAVE_IPV6)
+static char* encode_cmsghdr_data_ipv6(ErlNifEnv*     env,
+                                      ERL_NIF_TERM   ctrlBuf,
+                                      int            type,
+                                      unsigned char* dataP,
+                                      size_t         dataPos,
+                                      size_t         dataLen,
+                                      ERL_NIF_TERM*  eCMsgHdrData);
+#endif
+extern char* encode_msghdr_flags(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 int              msgFlags,
+                                 ERL_NIF_TERM*    flags);
+static char* decode_cmsghdr_data(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 char*            bufP,
+                                 size_t           rem,
+                                 int              level,
+                                 int              type,
+                                 ERL_NIF_TERM     eData,
+                                 size_t*          used);
+static char* decode_cmsghdr_final(ESockDescriptor* descP,
+                                  char*            bufP,
+                                  size_t           rem,
+                                  int              level,
+                                  int              type,
+                                  char*            data,
+                                  int              sz,
+                                  size_t*          used);
+static BOOLEAN_T decode_sock_linger(ErlNifEnv*     env,
+                                    ERL_NIF_TERM   eVal,
+                                    struct linger* valP);
+#if defined(IP_TOS)
+static BOOLEAN_T decode_ip_tos(ErlNifEnv*   env,
+                               ERL_NIF_TERM eVal,
+                               int*         val);
+#endif
+#if defined(IP_MTU_DISCOVER)
+static char* decode_ip_pmtudisc(ErlNifEnv*   env,
+                                ERL_NIF_TERM eVal,
+                                int*         val);
+#endif
+#if defined(IP_MTU_DISCOVER)
+static void encode_ip_pmtudisc(ErlNifEnv*    env,
+                               int           val,
+                               ERL_NIF_TERM* eVal);
+#endif
+#if defined(IPV6_MTU_DISCOVER)
+static char* decode_ipv6_pmtudisc(ErlNifEnv*   env,
+                                  ERL_NIF_TERM eVal,
+                                  int*         val);
+#endif
+#if defined(IPV6_MTU_DISCOVER)
+static void encode_ipv6_pmtudisc(ErlNifEnv*    env,
+                                 int           val,
+                                 ERL_NIF_TERM* eVal);
+#endif
+
+/*
+static BOOLEAN_T decode_bool(ErlNifEnv*   env,
+                             ERL_NIF_TERM eVal,
+                             BOOLEAN_T*   val);
+*/
+static BOOLEAN_T decode_native_get_opt(ErlNifEnv*   env,
+                                       ERL_NIF_TERM eVal,
+                                       int*         opt,
+                                       Uint16*      valueType,
+                                       int*         valueSz);
+// static void encode_bool(BOOLEAN_T val, ERL_NIF_TERM* eVal);
+static ERL_NIF_TERM encode_ip_tos(ErlNifEnv* env, int val);
+
+static void esock_stop_handle_current(ErlNifEnv*       env,
+                                      const char*      role,
+                                      ESockDescriptor* descP,
+                                      ERL_NIF_TERM     sockRef,
+                                      ESockRequestor*  reqP);
+static void inform_waiting_procs(ErlNifEnv*         env,
+                                 const char*        role,
+                                 ESockDescriptor*   descP,
+                                 ERL_NIF_TERM       sockRef,
+                                 ESockRequestQueue* q,
+                                 BOOLEAN_T          free,
+                                 ERL_NIF_TERM       reason);
+
+static int socket_setopt(int             sock,
+                         int             level,
+                         int             opt,
+                         const void*     optVal,
+                         const socklen_t optLen);
+
+static BOOLEAN_T is_connector(ErlNifEnv*       env,
+                              ESockDescriptor* descP);
+static BOOLEAN_T verify_is_connected(ESockDescriptor* descP, int* err);
+
+static ESockDescriptor* alloc_descriptor(SOCKET sock, HANDLE event);
+
+
+static BOOLEAN_T edomain2domain(int edomain, int* domain);
+static BOOLEAN_T etype2type(int etype, int* type);
+static BOOLEAN_T eproto2proto(ErlNifEnv*         env,
+                              const ERL_NIF_TERM eproto,
+                              int*               proto);
+static BOOLEAN_T ehow2how(unsigned int ehow, int* how);
+static BOOLEAN_T esendflags2sendflags(unsigned int esendflags, int* sendflags);
+static BOOLEAN_T erecvflags2recvflags(unsigned int erecvflags, int* recvflags);
+static BOOLEAN_T elevel2level(BOOLEAN_T  isEncoded,
+                              int        eLevel,
+                              BOOLEAN_T* isOTP,
+                              int*       level);
+#ifdef HAVE_SETNS
+static BOOLEAN_T emap2netns(ErlNifEnv* env, ERL_NIF_TERM map, char** netns);
+static BOOLEAN_T change_network_namespace(char* netns, int* cns, int* err);
+static BOOLEAN_T restore_network_namespace(int ns, SOCKET sock, int* err);
+#endif
+
+static BOOLEAN_T cnt_inc(Uint32* cnt, Uint32 inc);
+static void      cnt_dec(Uint32* cnt, Uint32 dec);
+
+static void inc_socket(int domain, int type, int protocol);
+static void dec_socket(int domain, int type, int protocol);
+
+
+
+/* *** activate_next_acceptor ***
+ * *** activate_next_writer   ***
+ * *** activate_next_reader   ***
+ *
+ * All the activate-next functions for acceptor, writer and reader
+ * have exactly the same API, so we apply some macro magic to simplify.
+ * They simply operates on dufferent data structures.
+ *
+ */
+
+#define ACTIVATE_NEXT_FUNCS_DEFS     \
+    ACTIVATE_NEXT_FUNC_DEF(acceptor) \
+    ACTIVATE_NEXT_FUNC_DEF(writer)   \
+    ACTIVATE_NEXT_FUNC_DEF(reader)
+
+#define ACTIVATE_NEXT_FUNC_DEF(F)                                 \
+    static BOOLEAN_T activate_next_##F(ErlNifEnv*       env,      \
+                                       ESockDescriptor* descP,    \
+                                       ERL_NIF_TERM     sockRef);
+ACTIVATE_NEXT_FUNCS_DEFS
+#undef ACTIVATE_NEXT_FUNC_DEF
+    
+/* *** acceptor_search4pid | writer_search4pid | reader_search4pid ***
+ * *** acceptor_push       | writer_push       | reader_push       ***
+ * *** acceptor_pop        | writer_pop        | reader_pop        ***
+ * *** acceptor_unqueue    | writer_unqueue    | reader_unqueue    ***
+ *
+ * All the queue operator functions (search4pid, push, pop
+ * and unqueue) for acceptor, writer and reader has exactly
+ * the same API, so we apply some macro magic to simplify.
+ */
+
+#define ESOCK_OPERATOR_FUNCS_DEFS      \
+    ESOCK_OPERATOR_FUNCS_DEF(acceptor) \
+    ESOCK_OPERATOR_FUNCS_DEF(writer)   \
+    ESOCK_OPERATOR_FUNCS_DEF(reader)
+
+#define ESOCK_OPERATOR_FUNCS_DEF(O)                            \
+    static BOOLEAN_T O##_search4pid(ErlNifEnv*       env,      \
+                                    ESockDescriptor* descP,    \
+                                    ErlNifPid*       pid);     \
+    static ERL_NIF_TERM O##_push(ErlNifEnv*       env,         \
+                                 ESockDescriptor* descP,       \
+                                 ErlNifPid        pid,         \
+                                 ERL_NIF_TERM     ref);        \
+    static BOOLEAN_T O##_pop(ErlNifEnv*       env,             \
+                             ESockDescriptor* descP,           \
+                             ESockRequestor*  reqP);           \
+    static BOOLEAN_T O##_unqueue(ErlNifEnv*       env,         \
+                                 ESockDescriptor* descP,       \
+                                 const ErlNifPid* pid);
+ESOCK_OPERATOR_FUNCS_DEFS
+#undef ESOCK_OPERATOR_FUNCS_DEF
+
+static BOOLEAN_T requestor_pop(ESockRequestQueue* q,
+                               ESockRequestor*    reqP);
+
+static BOOLEAN_T qsearch4pid(ErlNifEnv*         env,
+                             ESockRequestQueue* q,
+                             ErlNifPid*         pid);
+static void qpush(ESockRequestQueue*        q,
+                  ESockRequestQueueElement* e);
+static ESockRequestQueueElement* qpop(ESockRequestQueue* q);
+static BOOLEAN_T qunqueue(ErlNifEnv*         env,
+                          ESockDescriptor*   descP,
+                          const char*        slogan,
+                          ESockRequestQueue* q,
+                          const ErlNifPid*   pid);
+
+static int esock_monitor(const char*      slogan,
+                         ErlNifEnv*       env,
+                         ESockDescriptor* descP,
+                         const ErlNifPid* pid,
+                         ESockMonitor*    mon);
+static int esock_demonitor(const char*      slogan,
+                           ErlNifEnv*       env,
+                           ESockDescriptor* descP,
+                           ESockMonitor*    monP);
+static void esock_monitor_init(ESockMonitor* mon);
+static ERL_NIF_TERM esock_make_monitor_term(ErlNifEnv*          env,
+                                            const ESockMonitor* monP);
+
+
+#endif // if defined(__WIN32__)
+
+/*
+#if defined(HAVE_SYS_UN_H) || defined(SO_BINDTODEVICE)
+static size_t my_strnlen(const char *s, size_t maxlen);
+#endif
+*/
+
+static void esock_dtor(ErlNifEnv* env, void* obj);
+static void esock_stop(ErlNifEnv* env,
+                       void*      obj,
+                       int        fd,
+                       int        is_direct_call);
+static void esock_down(ErlNifEnv*           env,
+                       void*                obj,
+                       const ErlNifPid*     pid,
+                       const ErlNifMonitor* mon);
+
+#if !defined(__WIN32__)
+
+static void esock_down_acceptor(ErlNifEnv*       env,
+                                ESockDescriptor* descP,
+                                ERL_NIF_TERM     sockRef,
+                                const ErlNifPid* pid);
+static void esock_down_writer(ErlNifEnv*       env,
+                              ESockDescriptor* descP,
+                              ERL_NIF_TERM     sockRef,
+                              const ErlNifPid* pid);
+static void esock_down_reader(ErlNifEnv*       env,
+                              ESockDescriptor* descP,
+                              ERL_NIF_TERM     sockRef,
+                              const ErlNifPid* pid);
+
+static char* esock_send_wrap_msg(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 ERL_NIF_TERM     sockRef,
+                                 ERL_NIF_TERM     cnt);
+static char* esock_send_close_msg(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  ErlNifPid*       pid);
+static char* esock_send_abort_msg(ErlNifEnv*   env,
+                                  ERL_NIF_TERM sockRef,
+                                  ERL_NIF_TERM recvRef,
+                                  ErlNifEnv*   msgEnv,
+                                  ERL_NIF_TERM reason,
+                                  ErlNifPid*   pid);
+static char* esock_send_msg(ErlNifEnv*   env,
+                            ErlNifPid*   pid,
+                            ERL_NIF_TERM msg,
+                            ErlNifEnv*   msgEnv);
+
+static ERL_NIF_TERM mk_abort_msg(ErlNifEnv*   env,
+                                 ERL_NIF_TERM sockRef,
+                                 ERL_NIF_TERM opRef,
+                                 ERL_NIF_TERM reason);
+static ERL_NIF_TERM mk_wrap_msg(ErlNifEnv*   env,
+                                ERL_NIF_TERM sockRef,
+                                ERL_NIF_TERM cnt);
+static ERL_NIF_TERM mk_close_msg(ErlNifEnv*   env,
+                                 ERL_NIF_TERM sockRef,
+                                 ERL_NIF_TERM closeRef);
+static ERL_NIF_TERM mk_select_msg(ErlNifEnv*   env,
+                                  ERL_NIF_TERM sockRef,
+                                  ERL_NIF_TERM selectRef);
+static ERL_NIF_TERM mk_socket_msg(ErlNifEnv*   env,
+                                  ERL_NIF_TERM sockRef,
+                                  ERL_NIF_TERM tag,
+                                  ERL_NIF_TERM info);
+static ERL_NIF_TERM mk_socket(ErlNifEnv*   env,
+                              ERL_NIF_TERM sockRef);
+
+static int esock_select_read(ErlNifEnv*       env,
+                             ErlNifEvent      event,
+                             void*            obj,
+                             const ErlNifPid* pid,
+                             ERL_NIF_TERM     sockRef,
+                             ERL_NIF_TERM     selectRef);
+static int esock_select_write(ErlNifEnv*       env,
+                              ErlNifEvent      event,
+                              void*            obj,
+                              const ErlNifPid* pid,
+                              ERL_NIF_TERM     sockRef,
+                              ERL_NIF_TERM     selectRef);
+static int esock_select_stop(ErlNifEnv*  env,
+                             ErlNifEvent event,
+                             void*       obj);
+static int esock_select_cancel(ErlNifEnv*             env,
+                               ErlNifEvent            event,
+                               enum ErlNifSelectFlags mode,
+                               void*                  obj);
+
+static BOOLEAN_T extract_debug(ErlNifEnv*   env,
+                               ERL_NIF_TERM map);
+static BOOLEAN_T extract_iow(ErlNifEnv*   env,
+                             ERL_NIF_TERM map);
+
+#endif // if defined(__WIN32__)
+
+static int on_load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info);
+
+
+
+#if HAVE_IN6
+#  if ! defined(HAVE_IN6ADDR_ANY) || ! HAVE_IN6ADDR_ANY
+#    if HAVE_DECL_IN6ADDR_ANY_INIT
+static const struct in6_addr in6addr_any = { { IN6ADDR_ANY_INIT } };
+#    else
+static const struct in6_addr in6addr_any =
+    { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } };
+#    endif /* HAVE_IN6ADDR_ANY_INIT */
+#  endif /* ! HAVE_DECL_IN6ADDR_ANY */
+
+#  if ! defined(HAVE_IN6ADDR_LOOPBACK) || ! HAVE_IN6ADDR_LOOPBACK
+#    if HAVE_DECL_IN6ADDR_LOOPBACK_INIT
+static const struct in6_addr in6addr_loopback =
+    { { IN6ADDR_LOOPBACK_INIT } };
+#    else
+static const struct in6_addr in6addr_loopback =
+    { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 } } };
+#    endif /* HAVE_IN6ADDR_LOOPBACk_INIT */
+#  endif /* ! HAVE_DECL_IN6ADDR_LOOPBACK */
+#endif /* HAVE_IN6 */
+
+
+
+/* (special) error string constants */
+static char str_exmon[]          = "exmonitor";  // failed monitor
+static char str_exself[]         = "exself";     // failed self
+static char str_exsend[]         = "exsend";     // failed send
+
+
+
+/* *** Global atoms *** 
+ * Note that when an (global) atom is added here, it must also be added
+ * in the socket_int.h file!
+ */
+#define GLOBAL_ATOMS                                   \
+    GLOBAL_ATOM_DECL(abort);                           \
+    GLOBAL_ATOM_DECL(accept);                          \
+    GLOBAL_ATOM_DECL(acceptconn);                      \
+    GLOBAL_ATOM_DECL(acceptfilter);                    \
+    GLOBAL_ATOM_DECL(adaption_layer);                  \
+    GLOBAL_ATOM_DECL(addr);                            \
+    GLOBAL_ATOM_DECL(addrform);                        \
+    GLOBAL_ATOM_DECL(add_membership);                  \
+    GLOBAL_ATOM_DECL(add_source_membership);           \
+    GLOBAL_ATOM_DECL(any);                             \
+    GLOBAL_ATOM_DECL(associnfo);                       \
+    GLOBAL_ATOM_DECL(authhdr);                         \
+    GLOBAL_ATOM_DECL(auth_active_key);                 \
+    GLOBAL_ATOM_DECL(auth_asconf);                     \
+    GLOBAL_ATOM_DECL(auth_chunk);                      \
+    GLOBAL_ATOM_DECL(auth_delete_key);                 \
+    GLOBAL_ATOM_DECL(auth_key);                        \
+    GLOBAL_ATOM_DECL(auth_level);                      \
+    GLOBAL_ATOM_DECL(autoclose);                       \
+    GLOBAL_ATOM_DECL(bindtodevice);                    \
+    GLOBAL_ATOM_DECL(block_source);                    \
+    GLOBAL_ATOM_DECL(broadcast);                       \
+    GLOBAL_ATOM_DECL(busy_poll);                       \
+    GLOBAL_ATOM_DECL(checksum);                        \
+    GLOBAL_ATOM_DECL(close);                           \
+    GLOBAL_ATOM_DECL(command);                         \
+    GLOBAL_ATOM_DECL(connect);                         \
+    GLOBAL_ATOM_DECL(congestion);                      \
+    GLOBAL_ATOM_DECL(context);                         \
+    GLOBAL_ATOM_DECL(cork);                            \
+    GLOBAL_ATOM_DECL(credentials);                     \
+    GLOBAL_ATOM_DECL(ctrl);                            \
+    GLOBAL_ATOM_DECL(ctrunc);                          \
+    GLOBAL_ATOM_DECL(data);                            \
+    GLOBAL_ATOM_DECL(debug);                           \
+    GLOBAL_ATOM_DECL(default);                         \
+    GLOBAL_ATOM_DECL(default_send_params);             \
+    GLOBAL_ATOM_DECL(delayed_ack_time);                \
+    GLOBAL_ATOM_DECL(dgram);                           \
+    GLOBAL_ATOM_DECL(disable_fragments);               \
+    GLOBAL_ATOM_DECL(domain);                          \
+    GLOBAL_ATOM_DECL(dontfrag);                        \
+    GLOBAL_ATOM_DECL(dontroute);                       \
+    GLOBAL_ATOM_DECL(drop_membership);                 \
+    GLOBAL_ATOM_DECL(drop_source_membership);          \
+    GLOBAL_ATOM_DECL(dstopts);                         \
+    GLOBAL_ATOM_DECL(eor);                             \
+    GLOBAL_ATOM_DECL(error);                           \
+    GLOBAL_ATOM_DECL(errqueue);                        \
+    GLOBAL_ATOM_DECL(esp_network_level);               \
+    GLOBAL_ATOM_DECL(esp_trans_level);                 \
+    GLOBAL_ATOM_DECL(events);                          \
+    GLOBAL_ATOM_DECL(explicit_eor);                    \
+    GLOBAL_ATOM_DECL(faith);                           \
+    GLOBAL_ATOM_DECL(false);                           \
+    GLOBAL_ATOM_DECL(family);                          \
+    GLOBAL_ATOM_DECL(flags);                           \
+    GLOBAL_ATOM_DECL(flowinfo);                        \
+    GLOBAL_ATOM_DECL(fragment_interleave);             \
+    GLOBAL_ATOM_DECL(freebind);                        \
+    GLOBAL_ATOM_DECL(get_peer_addr_info);              \
+    GLOBAL_ATOM_DECL(hdrincl);                         \
+    GLOBAL_ATOM_DECL(hmac_ident);                      \
+    GLOBAL_ATOM_DECL(hoplimit);                        \
+    GLOBAL_ATOM_DECL(hopopts);                         \
+    GLOBAL_ATOM_DECL(ifindex);                         \
+    GLOBAL_ATOM_DECL(inet);                            \
+    GLOBAL_ATOM_DECL(inet6);                           \
+    GLOBAL_ATOM_DECL(info);                            \
+    GLOBAL_ATOM_DECL(initmsg);                         \
+    GLOBAL_ATOM_DECL(iov);                             \
+    GLOBAL_ATOM_DECL(ip);                              \
+    GLOBAL_ATOM_DECL(ipcomp_level);                    \
+    GLOBAL_ATOM_DECL(ipv6);                            \
+    GLOBAL_ATOM_DECL(i_want_mapped_v4_addr);           \
+    GLOBAL_ATOM_DECL(join_group);                      \
+    GLOBAL_ATOM_DECL(keepalive);                       \
+    GLOBAL_ATOM_DECL(keepcnt);                         \
+    GLOBAL_ATOM_DECL(keepidle);                        \
+    GLOBAL_ATOM_DECL(keepintvl);                       \
+    GLOBAL_ATOM_DECL(leave_group);                     \
+    GLOBAL_ATOM_DECL(level);                           \
+    GLOBAL_ATOM_DECL(linger);                          \
+    GLOBAL_ATOM_DECL(local);                           \
+    GLOBAL_ATOM_DECL(local_auth_chunks);               \
+    GLOBAL_ATOM_DECL(loopback);                        \
+    GLOBAL_ATOM_DECL(lowdelay);                        \
+    GLOBAL_ATOM_DECL(mark);                            \
+    GLOBAL_ATOM_DECL(maxburst);                        \
+    GLOBAL_ATOM_DECL(maxseg);                          \
+    GLOBAL_ATOM_DECL(md5sig);                          \
+    GLOBAL_ATOM_DECL(mincost);                         \
+    GLOBAL_ATOM_DECL(minttl);                          \
+    GLOBAL_ATOM_DECL(msfilter);                        \
+    GLOBAL_ATOM_DECL(mtu);                             \
+    GLOBAL_ATOM_DECL(mtu_discover);                    \
+    GLOBAL_ATOM_DECL(multicast_all);                   \
+    GLOBAL_ATOM_DECL(multicast_hops);                  \
+    GLOBAL_ATOM_DECL(multicast_if);                    \
+    GLOBAL_ATOM_DECL(multicast_loop);                  \
+    GLOBAL_ATOM_DECL(multicast_ttl);                   \
+    GLOBAL_ATOM_DECL(nodelay);                         \
+    GLOBAL_ATOM_DECL(nodefrag);                        \
+    GLOBAL_ATOM_DECL(noopt);                           \
+    GLOBAL_ATOM_DECL(nopush);                          \
+    GLOBAL_ATOM_DECL(not_found);                       \
+    GLOBAL_ATOM_DECL(not_owner);                       \
+    GLOBAL_ATOM_DECL(ok);                              \
+    GLOBAL_ATOM_DECL(oob);                             \
+    GLOBAL_ATOM_DECL(oobinline);                       \
+    GLOBAL_ATOM_DECL(options);                         \
+    GLOBAL_ATOM_DECL(origdstaddr);                     \
+    GLOBAL_ATOM_DECL(partial_delivery_point);          \
+    GLOBAL_ATOM_DECL(passcred);                        \
+    GLOBAL_ATOM_DECL(path);                            \
+    GLOBAL_ATOM_DECL(peekcred);                        \
+    GLOBAL_ATOM_DECL(peek_off);                        \
+    GLOBAL_ATOM_DECL(peer_addr_params);                \
+    GLOBAL_ATOM_DECL(peer_auth_chunks);                \
+    GLOBAL_ATOM_DECL(pktinfo);                         \
+    GLOBAL_ATOM_DECL(pktoptions);                      \
+    GLOBAL_ATOM_DECL(port);                            \
+    GLOBAL_ATOM_DECL(portrange);                       \
+    GLOBAL_ATOM_DECL(primary_addr);                    \
+    GLOBAL_ATOM_DECL(priority);                        \
+    GLOBAL_ATOM_DECL(protocol);                        \
+    GLOBAL_ATOM_DECL(raw);                             \
+    GLOBAL_ATOM_DECL(rcvbuf);                          \
+    GLOBAL_ATOM_DECL(rcvbufforce);                     \
+    GLOBAL_ATOM_DECL(rcvlowat);                        \
+    GLOBAL_ATOM_DECL(rcvtimeo);                        \
+    GLOBAL_ATOM_DECL(rdm);                             \
+    GLOBAL_ATOM_DECL(recv);                            \
+    GLOBAL_ATOM_DECL(recvdstaddr);                     \
+    GLOBAL_ATOM_DECL(recverr);                         \
+    GLOBAL_ATOM_DECL(recvfrom);                        \
+    GLOBAL_ATOM_DECL(recvif);                          \
+    GLOBAL_ATOM_DECL(recvmsg);                         \
+    GLOBAL_ATOM_DECL(recvopts);                        \
+    GLOBAL_ATOM_DECL(recvorigdstaddr);                 \
+    GLOBAL_ATOM_DECL(recvpktinfo);                     \
+    GLOBAL_ATOM_DECL(recvtclass);                      \
+    GLOBAL_ATOM_DECL(recvtos);                         \
+    GLOBAL_ATOM_DECL(recvttl);                         \
+    GLOBAL_ATOM_DECL(reliability);                     \
+    GLOBAL_ATOM_DECL(reset_streams);                   \
+    GLOBAL_ATOM_DECL(retopts);                         \
+    GLOBAL_ATOM_DECL(reuseaddr);                       \
+    GLOBAL_ATOM_DECL(reuseport);                       \
+    GLOBAL_ATOM_DECL(rights);                          \
+    GLOBAL_ATOM_DECL(router_alert);                    \
+    GLOBAL_ATOM_DECL(rthdr);                           \
+    GLOBAL_ATOM_DECL(rtoinfo);                         \
+    GLOBAL_ATOM_DECL(rxq_ovfl);                        \
+    GLOBAL_ATOM_DECL(scope_id);                        \
+    GLOBAL_ATOM_DECL(sctp);                            \
+    GLOBAL_ATOM_DECL(sec);                             \
+    GLOBAL_ATOM_DECL(select_failed);                   \
+    GLOBAL_ATOM_DECL(select_sent);                     \
+    GLOBAL_ATOM_DECL(send);                            \
+    GLOBAL_ATOM_DECL(sendmsg);                         \
+    GLOBAL_ATOM_DECL(sendsrcaddr);                     \
+    GLOBAL_ATOM_DECL(sendto);                          \
+    GLOBAL_ATOM_DECL(seqpacket);                       \
+    GLOBAL_ATOM_DECL(setfib);                          \
+    GLOBAL_ATOM_DECL(set_peer_primary_addr);           \
+    GLOBAL_ATOM_DECL(socket);                          \
+    GLOBAL_ATOM_DECL(sndbuf);                          \
+    GLOBAL_ATOM_DECL(sndbufforce);                     \
+    GLOBAL_ATOM_DECL(sndlowat);                        \
+    GLOBAL_ATOM_DECL(sndtimeo);                        \
+    GLOBAL_ATOM_DECL(spec_dst);                        \
+    GLOBAL_ATOM_DECL(status);                          \
+    GLOBAL_ATOM_DECL(stream);                          \
+    GLOBAL_ATOM_DECL(syncnt);                          \
+    GLOBAL_ATOM_DECL(tclass);                          \
+    GLOBAL_ATOM_DECL(tcp);                             \
+    GLOBAL_ATOM_DECL(throughput);                      \
+    GLOBAL_ATOM_DECL(timestamp);                       \
+    GLOBAL_ATOM_DECL(tos);                             \
+    GLOBAL_ATOM_DECL(transparent);                     \
+    GLOBAL_ATOM_DECL(true);                            \
+    GLOBAL_ATOM_DECL(trunc);                           \
+    GLOBAL_ATOM_DECL(ttl);                             \
+    GLOBAL_ATOM_DECL(type);                            \
+    GLOBAL_ATOM_DECL(udp);                             \
+    GLOBAL_ATOM_DECL(unblock_source);                  \
+    GLOBAL_ATOM_DECL(undefined);                       \
+    GLOBAL_ATOM_DECL(unicast_hops);                    \
+    GLOBAL_ATOM_DECL(unknown);                         \
+    GLOBAL_ATOM_DECL(usec);                            \
+    GLOBAL_ATOM_DECL(user_timeout);                    \
+    GLOBAL_ATOM_DECL(use_ext_recvinfo);                \
+    GLOBAL_ATOM_DECL(use_min_mtu);                     \
+    GLOBAL_ATOM_DECL(v6only);
+
+
+/* *** Global error reason atoms *** */
+#define GLOBAL_ERROR_REASON_ATOMS   \
+    GLOBAL_ATOM_DECL(eagain);       \
+    GLOBAL_ATOM_DECL(eafnosupport); \
+    GLOBAL_ATOM_DECL(einval);
+
+
+#define GLOBAL_ATOM_DECL(A) ERL_NIF_TERM esock_atom_##A
+GLOBAL_ATOMS
+GLOBAL_ERROR_REASON_ATOMS
+#undef GLOBAL_ATOM_DECL
+ERL_NIF_TERM esock_atom_socket_tag; // This has a "special" name ('$socket')
+
+/* *** Local atoms *** */
+#define LOCAL_ATOMS                    \
+    LOCAL_ATOM_DECL(adaptation_layer); \
+    LOCAL_ATOM_DECL(address);          \
+    LOCAL_ATOM_DECL(association);      \
+    LOCAL_ATOM_DECL(assoc_id);         \
+    LOCAL_ATOM_DECL(authentication);   \
+    LOCAL_ATOM_DECL(bool);             \
+    LOCAL_ATOM_DECL(close);            \
+    LOCAL_ATOM_DECL(closed);           \
+    LOCAL_ATOM_DECL(closing);          \
+    LOCAL_ATOM_DECL(cookie_life);      \
+    LOCAL_ATOM_DECL(counter_wrap);     \
+    LOCAL_ATOM_DECL(counters);         \
+    LOCAL_ATOM_DECL(data_in);          \
+    LOCAL_ATOM_DECL(do);               \
+    LOCAL_ATOM_DECL(dont);             \
+    LOCAL_ATOM_DECL(exclude);          \
+    LOCAL_ATOM_DECL(false);            \
+    LOCAL_ATOM_DECL(global_counters);  \
+    LOCAL_ATOM_DECL(in4_sockaddr);     \
+    LOCAL_ATOM_DECL(in6_sockaddr);     \
+    LOCAL_ATOM_DECL(include);          \
+    LOCAL_ATOM_DECL(initial);          \
+    LOCAL_ATOM_DECL(int);              \
+    LOCAL_ATOM_DECL(interface);        \
+    LOCAL_ATOM_DECL(iow);              \
+    LOCAL_ATOM_DECL(local_rwnd);       \
+    LOCAL_ATOM_DECL(max);              \
+    LOCAL_ATOM_DECL(max_attempts);     \
+    LOCAL_ATOM_DECL(max_init_timeo);   \
+    LOCAL_ATOM_DECL(max_instreams);    \
+    LOCAL_ATOM_DECL(max_rxt);          \
+    LOCAL_ATOM_DECL(min);              \
+    LOCAL_ATOM_DECL(mode);             \
+    LOCAL_ATOM_DECL(multiaddr);        \
+    LOCAL_ATOM_DECL(null);             \
+    LOCAL_ATOM_DECL(num_acceptors);    \
+    LOCAL_ATOM_DECL(num_dinet);        \
+    LOCAL_ATOM_DECL(num_dinet6);       \
+    LOCAL_ATOM_DECL(num_dlocal);       \
+    LOCAL_ATOM_DECL(num_outstreams);   \
+    LOCAL_ATOM_DECL(num_peer_dests);   \
+    LOCAL_ATOM_DECL(num_pip);          \
+    LOCAL_ATOM_DECL(num_psctp);        \
+    LOCAL_ATOM_DECL(num_ptcp);         \
+    LOCAL_ATOM_DECL(num_pudp);         \
+    LOCAL_ATOM_DECL(num_readers);      \
+    LOCAL_ATOM_DECL(num_sockets);      \
+    LOCAL_ATOM_DECL(num_tdgrams);      \
+    LOCAL_ATOM_DECL(num_tseqpkgs);     \
+    LOCAL_ATOM_DECL(num_tstreams);     \
+    LOCAL_ATOM_DECL(num_writers);      \
+    LOCAL_ATOM_DECL(partial_delivery); \
+    LOCAL_ATOM_DECL(peer_error);       \
+    LOCAL_ATOM_DECL(peer_rwnd);        \
+    LOCAL_ATOM_DECL(probe);            \
+    LOCAL_ATOM_DECL(read_byte);        \
+    LOCAL_ATOM_DECL(read_fails);       \
+    LOCAL_ATOM_DECL(read_pkg);         \
+    LOCAL_ATOM_DECL(read_tries);       \
+    LOCAL_ATOM_DECL(read_waits);       \
+    LOCAL_ATOM_DECL(select);           \
+    LOCAL_ATOM_DECL(sender_dry);       \
+    LOCAL_ATOM_DECL(send_failure);     \
+    LOCAL_ATOM_DECL(shutdown);         \
+    LOCAL_ATOM_DECL(slist);            \
+    LOCAL_ATOM_DECL(sourceaddr);       \
+    LOCAL_ATOM_DECL(timeout);          \
+    LOCAL_ATOM_DECL(true);             \
+    LOCAL_ATOM_DECL(want);             \
+    LOCAL_ATOM_DECL(write_byte);       \
+    LOCAL_ATOM_DECL(write_fails);      \
+    LOCAL_ATOM_DECL(write_pkg);        \
+    LOCAL_ATOM_DECL(write_tries);      \
+    LOCAL_ATOM_DECL(write_waits);
+
+/* Local error reason atoms */
+#define LOCAL_ERROR_REASON_ATOMS                \
+    LOCAL_ATOM_DECL(eisconn);                   \
+    LOCAL_ATOM_DECL(enotclosing);               \
+    LOCAL_ATOM_DECL(enotconn);                  \
+    LOCAL_ATOM_DECL(exalloc);                   \
+    LOCAL_ATOM_DECL(exbadstate);                \
+    LOCAL_ATOM_DECL(exbusy);                    \
+    LOCAL_ATOM_DECL(exmon);                     \
+    LOCAL_ATOM_DECL(exself);                    \
+    LOCAL_ATOM_DECL(exsend);
+
+#define LOCAL_ATOM_DECL(LA) static ERL_NIF_TERM atom_##LA
+LOCAL_ATOMS
+LOCAL_ERROR_REASON_ATOMS
+#undef LOCAL_ATOM_DECL
+
+
+/* *** Sockets *** */
+static ErlNifResourceType*    esocks;
+static ErlNifResourceTypeInit esockInit = {
+   esock_dtor,
+   esock_stop,
+   (ErlNifResourceDown*) esock_down
+};
+
+// Initiated when the nif is loaded
+static ESockData data;
+
+
+/* These two (inline) functions are primarily intended for debugging,
+ * that is, to make it easy to add debug printouts.
+ */
+static ESOCK_INLINE void esock_free_env(const char* slogan, ErlNifEnv* env)
+{
+    SGDBG( ("SOCKET", "env free - %s: 0x%lX\r\n", slogan, env) );
+    // esock_dbg_printf("SOCK ENV", "free - %s: 0x%lX\r\n", slogan, env);
+
+    if (env != NULL) enif_free_env(env);
+}
+
+
+static ESOCK_INLINE ErlNifEnv* esock_alloc_env(const char* slogan)
+{
+    ErlNifEnv* env = enif_alloc_env();
+
+    SGDBG( ("SOCKET", "env alloc - %s: 0x%lX\r\n", slogan, env) );
+    // esock_dbg_printf("SOCK ENV", "alloc - %s: 0x%lX\r\n", slogan, env);
+
+    return env;
+}
+
+
+/* ----------------------------------------------------------------------
+ *  N I F   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ *
+ * Utility and admin functions:
+ * ----------------------------
+ * nif_info/0
+ * nif_command/1
+ * nif_supports/1
+ *
+ * The "proper" socket functions:
+ * ------------------------------
+ * nif_open(Domain, Type, Protocol, Extra)
+ * nif_bind(Sock, LocalAddr)
+ * nif_connect(Sock, SockAddr)
+ * nif_listen(Sock, Backlog)
+ * nif_accept(LSock, Ref)
+ * nif_send(Sock, SendRef, Data, Flags)
+ * nif_sendto(Sock, SendRef, Data, Dest, Flags)
+ * nif_sendmsg(Sock, SendRef, MsgHdr, Flags)
+ * nif_recv(Sock, RecvRef, Length, Flags)
+ * nif_recvfrom(Sock, RecvRef, BufSz, Flags)
+ * nif_recvmsg(Sock, RecvRef, BufSz, CtrlSz, Flags)
+ * nif_close(Sock)
+ * nif_shutdown(Sock, How)
+ * nif_sockname(Sock)
+ * nif_peername(Sock)
+ *
+ * And some functions to manipulate and retrieve socket options:
+ * -------------------------------------------------------------
+ * nif_setopt/5
+ * nif_getopt/4
+ *
+ * And some utility functions:
+ * -------------------------------------------------------------
+ *
+ * And some socket admin functions:
+ * -------------------------------------------------------------
+ * nif_cancel(Sock, Ref)
+ */
+
+
+/* ----------------------------------------------------------------------
+ * nif_info
+ *
+ * Description:
+ * This is currently just a placeholder...
+ */
+#define MKCT(E, T, C) MKT2((E), (T), MKUI((E), (C)))
+
+static
+ERL_NIF_TERM nif_info(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM info;
+
+    SGDBG( ("SOCKET", "nif_info -> entry with %d args\r\n", argc) );
+    
+    switch (argc) {
+    case 0:
+        info = esock_global_info(env);
+        break;
+
+    case 1:
+        {
+            ESockDescriptor* descP;
+
+            if (!ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP)) {
+                return enif_make_badarg(env);
+            }
+            SSDBG( descP, ("SOCKET", "nif_info -> get socket info\r\n") );
+            info = esock_socket_info(env, descP);
+        }
+        break;
+        
+    default:
+        return enif_make_badarg(env);
+    }
+
+    return info;
+
+#endif
+}
+
+
+/*
+ * This function return a property list containing "global" info.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_global_info(ErlNifEnv* env)
+{
+    ERL_NIF_TERM numSockets     = MKCT(env, atom_num_sockets,  data.numSockets);
+    ERL_NIF_TERM numTypeDGrams  = MKCT(env, atom_num_tdgrams,  data.numTypeDGrams);
+    ERL_NIF_TERM numTypeStreams = MKCT(env, atom_num_tstreams, data.numTypeStreams);
+    ERL_NIF_TERM numTypeSeqPkgs = MKCT(env, atom_num_tseqpkgs, data.numTypeSeqPkgs);
+    ERL_NIF_TERM numDomLocal    = MKCT(env, atom_num_dlocal,   data.numDomainLocal);
+    ERL_NIF_TERM numDomInet     = MKCT(env, atom_num_dinet,    data.numDomainInet);
+    ERL_NIF_TERM numDomInet6    = MKCT(env, atom_num_dinet6,   data.numDomainInet6);
+    ERL_NIF_TERM numProtoIP     = MKCT(env, atom_num_pip,      data.numProtoIP);
+    ERL_NIF_TERM numProtoTCP    = MKCT(env, atom_num_ptcp,     data.numProtoTCP);
+    ERL_NIF_TERM numProtoUDP    = MKCT(env, atom_num_pudp,     data.numProtoUDP);
+    ERL_NIF_TERM numProtoSCTP   = MKCT(env, atom_num_psctp,    data.numProtoSCTP);
+    ERL_NIF_TERM gcnt[]  = {numSockets,
+                            numTypeDGrams, numTypeStreams, numTypeSeqPkgs,
+                            numDomLocal, numDomInet, numDomInet6,
+                            numProtoIP, numProtoTCP, numProtoUDP, numProtoSCTP};
+    unsigned int lenGCnt = sizeof(gcnt) / sizeof(ERL_NIF_TERM);
+    ERL_NIF_TERM lgcnt   = MKLA(env, gcnt, lenGCnt);
+    ERL_NIF_TERM keys[]  = {esock_atom_debug, atom_iow, atom_global_counters};
+    ERL_NIF_TERM vals[]  = {BOOL2ATOM(data.dbg), BOOL2ATOM(data.iow), lgcnt};
+    ERL_NIF_TERM info;
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+    ESOCK_ASSERT( (numKeys == numVals) );
+
+    if (!MKMA(env, keys, vals, numKeys, &info))
+        return enif_make_badarg(env);
+
+    return info;
+}
+
+
+
+/*
+ * This function return a property *map*. The properties are: 
+ *    counters:  A list of each socket counter and there current values
+ *    readers:   The number of current and waiting readers
+ *    writers:   The number of current and waiting writers
+ *    acceptors: The number of current and waiting acceptors
+ */
+static
+ERL_NIF_TERM esock_socket_info(ErlNifEnv*       env,
+                               ESockDescriptor* descP)
+{
+    ERL_NIF_TERM counters  = esock_socket_info_counters(env, descP);
+    ERL_NIF_TERM readers   = esock_socket_info_readers(env, descP);
+    ERL_NIF_TERM writers   = esock_socket_info_writers(env, descP);
+    ERL_NIF_TERM acceptors = esock_socket_info_acceptors(env, descP);
+    ERL_NIF_TERM keys[]    = {atom_counters, atom_num_readers,
+                              atom_num_writers, atom_num_acceptors};
+    ERL_NIF_TERM vals[]    = {counters, readers, writers, acceptors};
+    ERL_NIF_TERM info;
+    unsigned int numKeys  = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals  = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+    SSDBG( descP, ("SOCKET", "esock_socket_info -> "
+                   "\r\n   numKeys: %d"
+                   "\r\n   numVals: %d"
+                   "\r\n", numKeys, numVals) );
+
+    ESOCK_ASSERT( (numKeys == numVals) );
+
+    if (!MKMA(env, keys, vals, numKeys, &info))
+        return enif_make_badarg(env);
+
+    SSDBG( descP, ("SOCKET", "esock_socket_info -> done with"
+                   "\r\n   info: %T"
+                   "\r\n", info) );
+
+    return info;
+    
+}
+
+
+/*
+ * Collect all counters for a socket.
+ */
+static
+ERL_NIF_TERM esock_socket_info_counters(ErlNifEnv*       env,
+                                        ESockDescriptor* descP)
+{
+    ERL_NIF_TERM info;
+
+    MLOCK(descP->writeMtx);
+    MLOCK(descP->readMtx);
+
+    {
+        ERL_NIF_TERM readByteCnt  = MKCT(env, atom_read_byte, descP->readByteCnt);
+        ERL_NIF_TERM readFails    = MKCT(env, atom_read_fails, descP->readFails);
+        ERL_NIF_TERM readPkgCnt   = MKCT(env, atom_read_pkg, descP->readPkgCnt);
+        ERL_NIF_TERM readTries    = MKCT(env, atom_read_tries, descP->readTries);
+        ERL_NIF_TERM readWaits    = MKCT(env, atom_read_waits, descP->readWaits);
+        ERL_NIF_TERM writeByteCnt = MKCT(env, atom_write_byte, descP->writeByteCnt);
+        ERL_NIF_TERM writeFails   = MKCT(env, atom_write_fails, descP->writeFails);
+        ERL_NIF_TERM writePkgCnt  = MKCT(env, atom_write_pkg, descP->writePkgCnt);
+        ERL_NIF_TERM writeTries   = MKCT(env, atom_write_tries, descP->writeTries);
+        ERL_NIF_TERM writeWaits   = MKCT(env, atom_write_waits, descP->writeWaits);
+        ERL_NIF_TERM acnt[]       = {readByteCnt, readFails, readPkgCnt,
+                                     readTries, readWaits,
+                                     writeByteCnt, writeFails, writePkgCnt,
+                                     writeTries, writeWaits};
+        unsigned int lenACnt      = sizeof(acnt) / sizeof(ERL_NIF_TERM);
+
+        info = MKLA(env, acnt, lenACnt);
+
+        SSDBG( descP, ("SOCKET", "esock_socket_info_counters -> "
+                       "\r\n   lenACnt: %d"
+                       "\r\n   info:    %T"
+                       "\r\n", lenACnt, info) );
+
+    }
+
+    MUNLOCK(descP->readMtx);
+    MUNLOCK(descP->writeMtx);
+
+    SSDBG( descP, ("SOCKET", "esock_socket_info_counters -> done with"
+                   "\r\n   info: %T"
+                   "\r\n", info) );
+
+    return info;
+}
+#endif
+
+
+/* ----------------------------------------------------------------------
+ * nif_command
+ *
+ * Description:
+ * This function is intended to handle "various" commands. That is,
+ * commands and operations that are not part of the socket API proper.
+ * Currently it handles setting the global debug. Its a map with two
+ * attributes command and (command) data:
+ * #{command :: atom(), data :: term()}
+ *
+ * Command                    Data
+ * debug                      boolean()
+ *
+ */
+
+static
+ERL_NIF_TERM nif_command(ErlNifEnv*         env,
+                         int                argc,
+                         const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM ecmd, ecdata, result;
+    Uint16       cmd;
+
+    SGDBG( ("SOCKET", "nif_command -> entry with %d args\r\n", argc) );
+
+    if ((argc != 1) ||
+        !IS_MAP(env,  argv[0])) {
+        return enif_make_badarg(env);
+    }
+    ecmd = argv[0];
+
+    SGDBG( ("SOCKET", "nif_command -> "
+            "\r\n   (e) command: %T"
+            "\r\n", ecmd) );
+
+    if (!ecommand2command(env, ecmd, &cmd, &ecdata)) {
+        SGDBG( ("SOCKET", "nif_command -> invalid command\r\n") );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    SGDBG( ("SOCKET", "nif_command -> "
+            "\r\n   command:          %d"
+            "\r\n   (e) command data: %T"
+            "\r\n", cmd, ecdata) );
+
+    result = esock_command(env, cmd, ecdata);
+    
+    SGDBG( ("SOCKET", "nif_command -> done with result: "
+           "\r\n   %T"
+           "\r\n", result) );
+
+    return result;
+
+#endif
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_command(ErlNifEnv* env, Uint16 cmd, ERL_NIF_TERM ecdata)
+{
+    ERL_NIF_TERM result;
+
+    SGDBG( ("SOCKET", "esock_command -> entry with 0x%lX\r\n", cmd) );
+
+    switch (cmd) {
+    case ESOCK_CMD_DEBUG:
+        result = esock_command_debug(env, ecdata);
+        break;
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+
+static
+ERL_NIF_TERM esock_command_debug(ErlNifEnv* env, ERL_NIF_TERM ecdata)
+{
+    ERL_NIF_TERM result;
+
+    /* The data *should* be a boolean() */
+
+    if (COMPARE(ecdata, esock_atom_true) == 0) {
+        data.dbg = TRUE;
+        result   = esock_atom_ok;
+    } else if (COMPARE(ecdata, esock_atom_false) == 0) {
+        data.dbg = FALSE;
+        result   = esock_atom_ok;
+    } else {
+        SGDBG( ("SOCKET", "esock_command_debug -> invalid debug value: %T\r\n",
+                ecdata) );
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    return result;
+}
+#endif
+
+
+/* *** esock_socket_info_readers   ***
+ * *** esock_socket_info_writers   ***
+ * *** esock_socket_info_acceptors ***
+ *
+ * Calculate how many readers | writers | acceptors we have for this socket.
+ * Current requestor + any waiting requestors (of the type).
+ *
+ */
+
+#if !defined(__WIN32__)
+#define ESOCK_INFO_REQ_FUNCS                                                  \
+    ESOCK_INFO_REQ_FUNC_DECL(readers,   readMtx,  currentReaderP,   readersQ) \
+    ESOCK_INFO_REQ_FUNC_DECL(writers,   writeMtx, currentWriterP,   writersQ) \
+    ESOCK_INFO_REQ_FUNC_DECL(acceptors, accMtx,   currentAcceptorP, acceptorsQ)
+
+#define ESOCK_INFO_REQ_FUNC_DECL(F, MTX, CRP, Q)                               \
+    static                                                                      \
+    ERL_NIF_TERM esock_socket_info_##F(ErlNifEnv*       env,                    \
+                                       ESockDescriptor* descP)                  \
+    {                                                                           \
+        return socket_info_reqs(env, descP, descP->MTX, descP->CRP, &descP->Q); \
+    }
+ESOCK_INFO_REQ_FUNCS
+#undef ESOCK_INFO_REQ_FUNC_DECL
+
+
+static
+ERL_NIF_TERM socket_info_reqs(ErlNifEnv*         env,
+                              ESockDescriptor*   descP,
+                              ErlNifMutex*       mtx,
+                              ESockRequestor*    crp,
+                              ESockRequestQueue* q)
+{
+    ESockRequestQueueElement* tmp;
+    ERL_NIF_TERM              info;
+    unsigned int              cnt = 0;
+
+    MLOCK(mtx);
+
+    if (crp != NULL) {
+        // We have an active requestor!
+        cnt++;
+
+        // And add all the waiting requestors
+        tmp = q->first;
+        while (tmp != NULL) {
+            cnt++;
+            tmp = tmp->nextP;
+        }
+    }
+
+    MUNLOCK(mtx);
+
+    info = MKUI(env, cnt);
+
+    SSDBG( descP, ("SOCKET", "socket_info_reqs -> done with"
+                   "\r\n   info: %T"
+                   "\r\n", info) );
+
+    return info;
+}
+#endif
+
+
+/* ----------------------------------------------------------------------
+ * nif_supports
+ *
+ * Description:
+ * This function is intended to answer the question: "Is X supported?"
+ * Currently three keys are "supported": options | sctp | ipv6
+ * That results in a list of all *known options* (known by us) and if
+ * the platform supports (OS) it or not.
+ *
+ * Key
+ * ---
+ * options         [{socket, [{Opt, boolean()}]},
+ *                  {ip,     [{Opt, boolean()}]},
+ *                  {ipv6,   [{Opt, boolean()}]},
+ *                  {tcp,    [{Opt, boolean()}]},
+ *                  {udp,    [{Opt, boolean()}]},
+ *                  {sctp,   [{Opt, boolean()}]}]
+ * sctp            boolean()
+ * ipv6            boolean()
+ * local           boolean()
+ */
+
+static
+ERL_NIF_TERM nif_supports(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    int key;
+    
+    SGDBG( ("SOCKET", "nif_supports -> entry with %d args\r\n", argc) );
+    
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !GET_INT(env, argv[0], &key)) {
+        return enif_make_badarg(env);
+    }
+
+    return esock_supports(env, key);
+#endif
+}
+
+
+
+/* esock_supports - what features do we support
+ *
+ * This is to prove information about what features actually
+ * work on the current platform.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports(ErlNifEnv* env, int key)
+{
+    ERL_NIF_TERM result;
+
+    SGDBG( ("SOCKET", "esock_supports -> entry with 0x%lX\r\n", key) );
+
+    switch (key) {
+    case ESOCK_SUPPORTS_OPTIONS:
+        result = esock_supports_options(env);
+        break;
+
+    case ESOCK_SUPPORTS_SCTP:
+        result = esock_supports_sctp(env);
+        break;
+
+    case ESOCK_SUPPORTS_IPV6:
+        result = esock_supports_ipv6(env);
+        break;
+
+    case ESOCK_SUPPORTS_LOCAL:
+        result = esock_supports_local(env);
+        break;
+
+    default:
+        result = esock_atom_false;
+        break;
+    }
+
+    return result;
+}
+#endif
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_options(ErlNifEnv* env)
+{
+    ERL_NIF_TERM sockOpts  = esock_supports_options_socket(env);
+    ERL_NIF_TERM sockOptsT = MKT2(env, esock_atom_socket, sockOpts);
+    ERL_NIF_TERM ipOpts    = esock_supports_options_ip(env);
+    ERL_NIF_TERM ipOptsT   = MKT2(env, esock_atom_ip, ipOpts);
+    ERL_NIF_TERM ipv6Opts  = esock_supports_options_ipv6(env);
+    ERL_NIF_TERM ipv6OptsT = MKT2(env, esock_atom_ipv6, ipv6Opts);
+    ERL_NIF_TERM tcpOpts   = esock_supports_options_tcp(env);
+    ERL_NIF_TERM tcpOptsT  = MKT2(env, esock_atom_tcp, tcpOpts);
+    ERL_NIF_TERM udpOpts   = esock_supports_options_udp(env);
+    ERL_NIF_TERM udpOptsT  = MKT2(env, esock_atom_udp, udpOpts);
+    ERL_NIF_TERM sctpOpts  = esock_supports_options_sctp(env);
+    ERL_NIF_TERM sctpOptsT = MKT2(env, esock_atom_sctp, sctpOpts);
+    ERL_NIF_TERM optsA[]   = {sockOptsT,
+                              ipOptsT, ipv6OptsT,
+                              tcpOptsT, udpOptsT, sctpOptsT};
+    unsigned int lenOptsA  = sizeof(optsA) / sizeof(ERL_NIF_TERM);
+    ERL_NIF_TERM optsL     = MKLA(env, optsA, lenOptsA);
+
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_options_socket(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(128);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** ESOCK_OPT_SOCK_ACCEPTCONN => SO_ACCEPTCONN *** */
+#if defined(SO_ACCEPTCONN)
+    tmp = MKT2(env, esock_atom_acceptconn, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_acceptconn, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_ACCEPTFILTER => SO_ACCEPTFILTER *** */
+    tmp = MKT2(env, esock_atom_acceptfilter, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_BINDTODEVICE => SO_BINDTODEVICE *** */
+#if defined(SO_BINDTODEVICE)
+    tmp = MKT2(env, esock_atom_bindtodevice, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_bindtodevice, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_BROADCAST => SO_BROADCAST *** */
+#if defined(SO_BROADCAST)
+    tmp = MKT2(env, esock_atom_broadcast, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_broadcast, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_BUSY_POLL => SO_BUSY_POLL *** */
+    tmp = MKT2(env, esock_atom_busy_poll, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_DEBUG => SO_DEBUG *** */
+#if defined(SO_DEBUG)
+    tmp = MKT2(env, esock_atom_debug, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_debug, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_DOMAIN => SO_DOMAIN *** */
+#if defined(SO_DOMAIN)
+    tmp = MKT2(env, esock_atom_domain, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_domain, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_DONTROUTE => SO_DONTROUTE *** */
+#if defined(SO_DONTROUTE)
+    tmp = MKT2(env, esock_atom_dontroute, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_dontroute, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_ERROR => SO_ERROR *** */
+    tmp = MKT2(env, esock_atom_error, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_KEEPALIVE => SO_KEEPALIVE *** */
+#if defined(SO_KEEPALIVE)
+    tmp = MKT2(env, esock_atom_keepalive, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_keepalive, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_LINGER => SO_LINGER *** */
+#if defined(SO_LINGER)
+    tmp = MKT2(env, esock_atom_linger, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_linger, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_MARK => SO_MARK *** */
+    tmp = MKT2(env, esock_atom_mark, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_OOBINLINE => SO_OOBINLINE *** */
+#if defined(SO_OOBINLINE)
+    tmp = MKT2(env, esock_atom_oobinline, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_oobinline, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_PASSCRED => SO_PASSCRED *** */
+    tmp = MKT2(env, esock_atom_passcred, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_PEEK_OFF => SO_PEEK_OFF *** */
+#if defined(SO_PEEK_OFF)
+    tmp = MKT2(env, esock_atom_peek_off, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_peek_off, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_PEEKCRED => SO_PEEKCRED *** */
+    tmp = MKT2(env, esock_atom_peekcred, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_PRIORITY => SO_PRIORITY *** */
+#if defined(SO_PRIORITY)
+    tmp = MKT2(env, esock_atom_priority, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_priority, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_PROTOCOL => SO_PROTOCOL *** */
+#if defined(SO_PROTOCOL)
+    tmp = MKT2(env, esock_atom_protocol, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_protocol, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_RCVBUF => SO_RCVBUF *** */
+#if defined(SO_RCVBUF)
+    tmp = MKT2(env, esock_atom_rcvbuf, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rcvbuf, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_RCVBUFFORCE => SO_RCVBUFFORCE *** */
+    tmp = MKT2(env, esock_atom_rcvbufforce, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_RCVLOWAT => SO_RCVLOWAT *** */
+#if defined(SO_RCVLOWAT)
+    tmp = MKT2(env, esock_atom_rcvlowat, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rcvlowat, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_RCVTIMEO => SO_RCVTIMEO *** */
+#if defined(SO_RCVTIMEO)
+    tmp = MKT2(env, esock_atom_rcvtimeo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rcvtimeo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_REUSEADDR => SO_REUSEADDR *** */
+#if defined(SO_REUSEADDR)
+    tmp = MKT2(env, esock_atom_reuseaddr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_reuseaddr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_REUSEPORT => SO_REUSEPORT *** */
+#if defined(SO_REUSEPORT)
+    tmp = MKT2(env, esock_atom_reuseport, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_reuseport, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_RXQ_OVFL => SO_RXQ_OVFL *** */
+    tmp = MKT2(env, esock_atom_rxq_ovfl, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_SETFIB => SO_SETFIB *** */
+    tmp = MKT2(env, esock_atom_setfib, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_SNDBUF => SO_SNDBUF *** */
+#if defined(SO_SNDBUF)
+    tmp = MKT2(env, esock_atom_sndbuf, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_sndbuf, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_SNDBUFFORCE => SO_SNDBUFFORCE *** */
+    tmp = MKT2(env, esock_atom_sndbufforce, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_SNDLOWAT => SO_SNDLOWAT *** */
+#if defined(SO_SNDLOWAT)
+    tmp = MKT2(env, esock_atom_sndlowat, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_sndlowat, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_SNDTIMEO => SO_SNDTIMEO *** */
+#if defined(SO_SNDTIMEO)
+    tmp = MKT2(env, esock_atom_sndtimeo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_sndtimeo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_TIMESTAMP => SO_TIMESTAMP *** */
+#if defined(SO_TIMESTAMP)
+    tmp = MKT2(env, esock_atom_timestamp, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_timestamp, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SOCK_TYPE => SO_TYPE *** */
+#if defined(SO_TYPE)
+    tmp = MKT2(env, esock_atom_type, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_type, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_options_ip(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(128);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** ESOCK_OPT_IP_ADD_MEMBERSHIP => IP_ADD_MEMBERSHIP *** */
+#if defined(IP_ADD_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_add_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_add_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_ADD_SOURCE_MEMBERSHIP => IP_ADD_SOURCE_MEMBERSHIP *** */
+#if defined(IP_ADD_SOURCE_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_add_source_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_add_source_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_BLOCK_SOURCE => IP_BLOCK_SOURCE *** */
+#if defined(IP_BLOCK_SOURCE)
+    tmp = MKT2(env, esock_atom_block_source, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_block_source, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_DONTFRAG => IP_DONTFRAG *** */
+    tmp = MKT2(env, esock_atom_dontfrag, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_DROP_MEMBERSHIP => IP_DROP_MEMBERSHIP *** */
+#if defined(IP_DROP_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_drop_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_drop_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_DROP_SOURCE_MEMBERSHIP => IP_DROP_SOURCE_MEMBERSHIP *** */
+#if defined(IP_DROP_SOURCE_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_drop_source_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_drop_source_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_FREEBIND => IP_FREEBIND *** */
+#if defined(IP_FREEBIND)
+    tmp = MKT2(env, esock_atom_freebind, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_freebind, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_HDRINCL => IP_HDRINCL *** */
+#if defined(IP_HDRINCL)
+    tmp = MKT2(env, esock_atom_hdrincl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_hdrincl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_MINTTL => IP_MINTTL *** */
+#if defined(IP_MINTTL)
+    tmp = MKT2(env, esock_atom_minttl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_minttl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_MSFILTER => IP_MSFILTER / IP_MSFILTER_SIZE *** */
+#if defined(IP_MSFILTER) && defined(IP_MSFILTER_SIZE)
+    tmp = MKT2(env, esock_atom_msfilter, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_msfilter, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_MTU => IP_MTU *** */
+    tmp = MKT2(env, esock_atom_mtu, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_MTU_DISCOVER => IP_MTU_DISCOVER *** */
+#if defined(IP_MTU_DISCOVER)
+    tmp = MKT2(env, esock_atom_mtu_discover, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_mtu_discover, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_MULTICAST_ALL => IP_MULTICAST_ALL *** */
+#if defined(IP_MULTICAST_ALL)
+    tmp = MKT2(env, esock_atom_multicast_all, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_all, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_MULTICAST_IF => IP_MULTICAST_IF *** */
+#if defined(IP_MULTICAST_IF)
+    tmp = MKT2(env, esock_atom_multicast_if, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_if, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_MULTICAST_LOOP => IP_MULTICAST_LOOP *** */
+#if defined(IP_MULTICAST_LOOP)
+    tmp = MKT2(env, esock_atom_multicast_loop, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_loop, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_MULTICAST_TTL => IP_MULTICAST_TTL *** */
+#if defined(IP_MULTICAST_TTL)
+    tmp = MKT2(env, esock_atom_multicast_ttl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_ttl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_NODEFRAG => IP_NODEFRAG *** */
+#if defined(IP_NODEFRAG)
+    tmp = MKT2(env, esock_atom_nodefrag, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_nodefrag, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_OPTIONS => IP_OPTIONS *** */
+    tmp = MKT2(env, esock_atom_options, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_PKTINFO => IP_PKTINFO *** */
+#if defined(IP_PKTINFO)
+    tmp = MKT2(env, esock_atom_pktinfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_pktinfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_RECVDSTADDR => IP_RECVDSTADDR *** */
+#if defined(IP_RECVDSTADDR)
+    tmp = MKT2(env, esock_atom_recvdstaddr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvdstaddr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_RECVERR => IP_RECVERR *** */
+#if defined(IP_RECVERR)
+    tmp = MKT2(env, esock_atom_recverr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recverr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_RECVIF => IP_RECVIF *** */
+#if defined(IP_RECVIF)
+    tmp = MKT2(env, esock_atom_recvif, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvif, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_RECVOPTS => IP_RECVOPTS *** */
+#if defined(IP_RECVOPTS)
+    tmp = MKT2(env, esock_atom_recvopts, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvopts, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_RECVORIGDSTADDR => IP_RECVORIGDSTADDR *** */
+#if defined(IP_RECVORIGDSTADDR)
+    tmp = MKT2(env, esock_atom_recvorigdstaddr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvorigdstaddr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_RECVTOS => IP_RECVTOS *** */
+#if defined(IP_RECVTOS)
+    tmp = MKT2(env, esock_atom_recvtos, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvtos, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_RECVTTL => IP_RECVTTL *** */
+#if defined(IP_RECVTTL)
+    tmp = MKT2(env, esock_atom_recvttl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvttl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_RETOPTS => IP_RETOPTS *** */
+#if defined(IP_RETOPTS)
+    tmp = MKT2(env, esock_atom_retopts, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_retopts, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_ROUTER_ALERT => IP_ROUTER_ALERT *** */
+#if defined(IP_ROUTER_ALERT)
+    tmp = MKT2(env, esock_atom_router_alert, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_router_alert, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_SENDSRCADDR => IP_SENDSRCADDR *** */
+#if defined(IP_SENDSRCADDR)
+    tmp = MKT2(env, esock_atom_sendsrcaddr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_sendsrcaddr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_TOS => IP_TOS *** */
+#if defined(IP_TOS)
+    tmp = MKT2(env, esock_atom_tos, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_tos, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_TRANSPARENT => IP_TRANSPARENT *** */
+#if defined(IP_TRANSPARENT)
+    tmp = MKT2(env, esock_atom_transparent, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_transparent, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_TTL => IP_TTL *** */
+#if defined(IP_TTL)
+    tmp = MKT2(env, esock_atom_ttl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_ttl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IP_UNBLOCK_SOURCE => IP_UNBLOCK_SOURCE *** */
+#if defined(IP_UNBLOCK_SOURCE)
+    tmp = MKT2(env, esock_atom_unblock_source, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_unblock_source, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_options_ipv6(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(128);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** ESOCK_OPT_IPV6_ADDRFORM => IPV6_ADDRFORM *** */
+#if defined(IPV6_ADDRFORM)
+    tmp = MKT2(env, esock_atom_addrform, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_addrform, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_ADD_MEMBERSHIP => IPV6_ADD_MEMBERSHIP *** */
+#if defined(IPV6_ADD_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_add_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_add_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_AUTHHDR => IPV6_AUTHHDR *** */
+#if defined(IPV6_AUTHHDR)
+    tmp = MKT2(env, esock_atom_authhdr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_authhdr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_AUTH_LEVEL => IPV6_AUTH_LEVEL *** */
+    tmp = MKT2(env, esock_atom_auth_level, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_CHECKSUM => IPV6_CHECKSUM *** */
+    tmp = MKT2(env, esock_atom_checksum, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_DROP_MEMBERSHIP => IPV6_DROP_MEMBERSHIP *** */
+#if defined(IPV6_DROP_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_drop_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_drop_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_DSTOPTS => IPV6_DSTOPTS *** */
+#if defined(IPV6_DSTOPTS)
+    tmp = MKT2(env, esock_atom_dstopts, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_dstopts, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_ESP_NETWORK_LEVEL => IPV6_ESP_NETWORK_LEVEL *** */
+    tmp = MKT2(env, esock_atom_esp_network_level, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_ESP_TRANS_LEVEL => IPV6_ESP_TRANS_LEVEL *** */
+    tmp = MKT2(env, esock_atom_esp_trans_level, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_FAITH => IPV6_FAITH *** */
+    tmp = MKT2(env, esock_atom_faith, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_FLOWINFO => IPV6_FLOWINFO *** */
+#if defined(IPV6_FLOWINFO)
+    tmp = MKT2(env, esock_atom_flowinfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_flowinfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_HOPLIMIT => IPV6_HOPLIMIT *** */
+#if defined(IPV6_HOPLIMIT)
+    tmp = MKT2(env, esock_atom_hoplimit, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_hoplimit, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_HOPOPTS => IPV6_HOPOPTS *** */
+#if defined(IPV6_HOPOPTS)
+    tmp = MKT2(env, esock_atom_hopopts, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_hopopts, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_IPCOMP_LEVEL => IPV6_IPCOMP_LEVEL *** */
+    tmp = MKT2(env, esock_atom_ipcomp_level, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_JOIN_GROUP => IPV6_JOIN_GROUP *** */
+    tmp = MKT2(env, esock_atom_join_group, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_LEAVE_GROUP => IPV6_LEAVE_GROUP *** */
+    tmp = MKT2(env, esock_atom_leave_group, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_MTU => IPV6_MTU *** */
+#if defined(IPV6_MTU)
+    tmp = MKT2(env, esock_atom_mtu, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_mtu, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_MTU_DISCOVER => IPV6_MTU_DISCOVER *** */
+#if defined(IPV6_MTU_DISCOVER)
+    tmp = MKT2(env, esock_atom_mtu_discover, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_mtu_discover, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_MULTICAST_HOPS => IPV6_MULTICAST_HOPS *** */
+#if defined(IPV6_MULTICAST_HOPS)
+    tmp = MKT2(env, esock_atom_multicast_hops, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_hops, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_MULTICAST_IF => IPV6_MULTICAST_IF *** */
+#if defined(IPV6_MULTICAST_IF)
+    tmp = MKT2(env, esock_atom_multicast_if, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_if, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_MULTICAST_LOOP => IPV6_MULTICAST_LOOP *** */
+#if defined(IPV6_MULTICAST_LOOP)
+    tmp = MKT2(env, esock_atom_multicast_loop, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_loop, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_PORTRANGE => IPV6_PORTRANGE *** */
+    tmp = MKT2(env, esock_atom_portrange, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_PKTOPTIONS => IPV6_PKTOPTIONS *** */
+    tmp = MKT2(env, esock_atom_pktoptions, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_RECVERR => IPV6_RECVERR *** */
+#if defined(IPV6_RECVERR)
+    tmp = MKT2(env, esock_atom_recverr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recverr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_RECVPKTINFO => IPV6_RECVPKTINFO *** */
+#if defined(IPV6_RECVPKTINFO)
+    tmp = MKT2(env, esock_atom_recvpktinfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvpktinfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_RECVTCLASS => IPV6_RECVTCLASS *** */
+    tmp = MKT2(env, esock_atom_recvtclass, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_ROUTER_ALERT => IPV6_ROUTER_ALERT *** */
+#if defined(IPV6_ROUTER_ALERT)
+    tmp = MKT2(env, esock_atom_router_alert, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_router_alert, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_RTHDR => IPV6_RTHDR *** */
+#if defined(IPV6_RTHDR)
+    tmp = MKT2(env, esock_atom_rthdr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rthdr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_TCLASS => IPV6_TCLASS *** */
+    tmp = MKT2(env, esock_atom_tclass, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_UNICAST_HOPS => IPV6_UNICAST_HOPS *** */
+#if defined(IPV6_UNICAST_HOPS)
+    tmp = MKT2(env, esock_atom_unicast_hops, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_unicast_hops, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_USE_MIN_MTU => IPV6_USE_MIN_MTU *** */
+    tmp = MKT2(env, esock_atom_use_min_mtu, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_IPV6_V6ONLY => IPV6_V6ONLY *** */
+#if defined(IPV6_V6ONLY)
+    tmp = MKT2(env, esock_atom_v6only, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_v6only, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_options_tcp(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(32);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** ESOCK_OPT_TCP_CONGESTION => TCP_CONGESTION *** */
+#if defined(TCP_CONGESTION)
+    tmp = MKT2(env, esock_atom_congestion, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_congestion, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_CORK => TCP_CORK *** */
+#if defined(TCP_CORK)
+    tmp = MKT2(env, esock_atom_cork, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_cork, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_INFO => TCP_INFO *** */
+    tmp = MKT2(env, esock_atom_info, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_KEEPCNT => TCP_KEEPCNT *** */
+    tmp = MKT2(env, esock_atom_keepcnt, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_KEEPIDLE => TCP_KEEPIDLE *** */
+    tmp = MKT2(env, esock_atom_keepidle, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_KEEPINTVL => TCP_KEEPINTVL *** */
+    tmp = MKT2(env, esock_atom_keepintvl, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_MAXSEG => TCP_MAXSEG *** */
+#if defined(TCP_MAXSEG)
+    tmp = MKT2(env, esock_atom_maxseg, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_maxseg, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_MD5SIG => TCP_MD5SIG *** */
+    tmp = MKT2(env, esock_atom_md5sig, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_NODELAY => TCP_NODELAY *** */
+#if defined(TCP_NODELAY)
+    tmp = MKT2(env, esock_atom_nodelay, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_nodelay, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_NOOPT => TCP_NOOPT *** */
+    tmp = MKT2(env, esock_atom_noopt, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_NOPUSH => TCP_NOPUSH *** */
+    tmp = MKT2(env, esock_atom_nopush, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_SYNCNT => TCP_SYNCNT *** */
+    tmp = MKT2(env, esock_atom_syncnt, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_TCP_USER_TIMEOUT => TCP_USER_TIMEOUT *** */
+    tmp = MKT2(env, esock_atom_user_timeout, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_options_udp(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(8);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** ESOCK_OPT_UDP_CORK => UDP_CORK *** */
+#if defined(UDP_CORK)
+    tmp = MKT2(env, esock_atom_cork, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_cork, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_options_sctp(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(64);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** ESOCK_OPT_SCTP_ADAPTION_LAYER => SCTP_ADAPTION_LAYER *** */
+    tmp = MKT2(env, esock_atom_adaption_layer, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_ASSOCINFO => SCTP_ASSOCINFO *** */
+#if defined(SCTP_ASSOCINFO)
+    tmp = MKT2(env, esock_atom_associnfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_associnfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_AUTH_ACTIVE_KEY => SCTP_AUTH_ACTIVE_KEY *** */
+    tmp = MKT2(env, esock_atom_auth_active_key, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_AUTH_ASCONF => SCTP_AUTH_ASCONF *** */
+    tmp = MKT2(env, esock_atom_auth_asconf, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_AUTH_CHUNK => SCTP_AUTH_CHUNK *** */
+    tmp = MKT2(env, esock_atom_auth_chunk, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_AUTH_DELETE_KEY => SCTP_AUTH_DELETE_KEY *** */
+    tmp = MKT2(env, esock_atom_auth_delete_key, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_AUTH_KEY => SCTP_AUTH_KEY *** */
+    tmp = MKT2(env, esock_atom_auth_key, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_AUTOCLOSE => SCTP_AUTOCLOSE *** */
+#if defined(SCTP_AUTOCLOSE)
+    tmp = MKT2(env, esock_atom_autoclose, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_autoclose, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_CONTEXT => SCTP_CONTEXT *** */
+    tmp = MKT2(env, esock_atom_context, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_DEFAULT_SEND_PARAMS => SCTP_DEFAULT_SEND_PARAMS *** */
+    tmp = MKT2(env, esock_atom_default_send_params, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_DELAYED_ACK_TIME => SCTP_DELAYED_ACK_TIME *** */
+    tmp = MKT2(env, esock_atom_delayed_ack_time, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_DISABLE_FRAGMENTS => SCTP_DISABLE_FRAGMENTS *** */
+#if defined(SCTP_DISABLE_FRAGMENTS)
+    tmp = MKT2(env, esock_atom_disable_fragments, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_disable_fragments, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_HMAC_IDENT => SCTP_HMAC_IDENT *** */
+    tmp = MKT2(env, esock_atom_hmac_ident, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_EVENTS => SCTP_EVENTS *** */
+#if defined(SCTP_EVENTS)
+    tmp = MKT2(env, esock_atom_events, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_events, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_EXPLICIT_EOR => SCTP_EXPLICIT_EOR *** */
+    tmp = MKT2(env, esock_atom_explicit_eor, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_FRAGMENT_INTERLEAVE => SCTP_FRAGMENT_INTERLEAVE *** */
+    tmp = MKT2(env, esock_atom_fragment_interleave, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_GET_PEER_ADDR_INFO => SCTP_GET_PEER_ADDR_INFO *** */
+    tmp = MKT2(env, esock_atom_get_peer_addr_info, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_INITMSG => SCTP_INITMSG *** */
+#if defined(SCTP_INITMSG)
+    tmp = MKT2(env, esock_atom_initmsg, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_initmsg, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_I_WANT_MAPPED_V4_ADDR => SCTP_I_WANT_MAPPED_V4_ADDR *** */
+    tmp = MKT2(env, esock_atom_i_want_mapped_v4_addr, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_LOCAL_AUTH_CHUNKS => SCTP_LOCAL_AUTH_CHUNKS *** */
+    tmp = MKT2(env, esock_atom_local_auth_chunks, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_MAXSEG => SCTP_MAXSEG *** */
+#if defined(SCTP_MAXSEG)
+    tmp = MKT2(env, esock_atom_maxseg, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_maxseg, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_MAXBURST => SCTP_MAXBURST *** */
+    tmp = MKT2(env, esock_atom_maxburst, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_NODELAY => SCTP_NODELAY *** */
+#if defined(SCTP_NODELAY)
+    tmp = MKT2(env, esock_atom_nodelay, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_nodelay, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_PARTIAL_DELIVERY_POINT => SCTP_PARTIAL_DELIVERY_POINT *** */
+    tmp = MKT2(env, esock_atom_partial_delivery_point, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_PEER_ADDR_PARAMS => SCTP_PEER_ADDR_PARAMS *** */
+    tmp = MKT2(env, esock_atom_peer_addr_params, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_PEER_AUTH_CHUNKS => SCTP_PEER_AUTH_CHUNKS *** */
+    tmp = MKT2(env, esock_atom_peer_auth_chunks, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_PRIMARY_ADDR => SCTP_PRIMARY_ADDR *** */
+    tmp = MKT2(env, esock_atom_primary_addr, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_RESET_STREAMS => SCTP_RESET_STREAMS *** */
+    tmp = MKT2(env, esock_atom_reset_streams, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_RTOINFO => SCTP_RTOINFO *** */
+#if defined(SCTP_RTOINFO)
+    tmp = MKT2(env, esock_atom_rtoinfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rtoinfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_SET_PEER_PRIMARY_ADDR => SCTP_SET_PEER_PRIMARY_ADDR *** */
+    tmp = MKT2(env, esock_atom_set_peer_primary_addr, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_STATUS => SCTP_STATUS *** */
+    tmp = MKT2(env, esock_atom_status, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** ESOCK_OPT_SCTP_USE_EXT_RECVINFO => SCTP_USE_EXT_RECVINFO *** */
+    tmp = MKT2(env, esock_atom_use_ext_recvinfo, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_sctp(ErlNifEnv* env)
+{
+    ERL_NIF_TERM supports;
+
+#if defined(HAVE_SCTP)
+    supports = esock_atom_true;
+#else
+    supports = esock_atom_false;
+#endif
+
+    return supports;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_ipv6(ErlNifEnv* env)
+{
+    ERL_NIF_TERM supports;
+
+    /* Is this (test) really sufficient for testing if we support IPv6? */
+#if defined(HAVE_IPV6)
+    supports = esock_atom_true;
+#else
+    supports = esock_atom_false;
+#endif
+
+    return supports;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_supports_local(ErlNifEnv* env)
+{
+    ERL_NIF_TERM supports;
+
+#if defined(AF_LOCAL)
+    supports = esock_atom_true;
+#else
+    supports = esock_atom_false;
+#endif
+
+    return supports;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_open
+ *
+ * Description:
+ * Create an endpoint for communication.
+ *
+ * Arguments:
+ * Domain   - The domain, for example 'inet'
+ * Type     - Type of socket, for example 'stream'
+ * Protocol - The protocol, for example 'tcp'
+ * Extra    - A map with "obscure" options.
+ *            Currently the only allowed option is netns (network namespace).
+ *            This is *only* allowed on linux!
+ *            We sould also use this for the fd value, in case we should use
+ *            an already existing (file) descriptor.
+ */
+static
+ERL_NIF_TERM nif_open(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    int          edomain, etype, eproto;
+    int          domain, type, proto;
+    char*        netns;
+    ERL_NIF_TERM emap;
+    ERL_NIF_TERM result;
+
+    SGDBG( ("SOCKET", "nif_open -> entry with %d args\r\n", argc) );
+    
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 4) ||
+        !GET_INT(env, argv[0], &edomain) ||
+        !GET_INT(env, argv[1], &etype) ||
+        !IS_MAP(env,  argv[3])) {
+        return enif_make_badarg(env);
+    }
+    eproto = argv[2];
+    emap   = argv[3];
+
+    SGDBG( ("SOCKET", "nif_open -> "
+            "\r\n   edomain: %T"
+            "\r\n   etype:   %T"
+            "\r\n   eproto:  %T"
+            "\r\n   extra:   %T"
+            "\r\n", argv[0], argv[1], eproto, emap) );
+
+    if (!edomain2domain(edomain, &domain)) {
+        SGDBG( ("SOCKET", "nif_open -> invalid domain: %d\r\n", edomain) );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if (!etype2type(etype, &type)) {
+        SGDBG( ("SOCKET", "nif_open -> invalid type: %d\r\n", etype) );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if (!eproto2proto(env, eproto, &proto)) {
+        SGDBG( ("SOCKET", "nif_open -> invalid protocol: %d\r\n", eproto) );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+#ifdef HAVE_SETNS
+    /* We *currently* only support one extra option: netns */
+    if (!emap2netns(env, emap, &netns)) {
+        SGDBG( ("SOCKET", "nif_open -> namespace: %s\r\n", netns) );
+        return enif_make_badarg(env);
+    }
+#else
+    netns = NULL;
+#endif
+
+
+    result = esock_open(env, domain, type, proto, netns);
+
+    SGDBG( ("SOCKET", "nif_open -> done with result: "
+           "\r\n   %T"
+           "\r\n", result) );
+
+    return result;
+
+#endif // if defined(__WIN32__)
+}
+
+
+/* esock_open - create an endpoint for communication
+ *
+ * Assumes the input has been validated.
+ *
+ * Normally we want debugging on (individual) sockets to be controlled
+ * by the sockets own debug flag. But since we don't even have a socket
+ * yet, we must use the global debug flag.
+ */
+#if !defined(__WIN32__)
+
+static
+ERL_NIF_TERM esock_open(ErlNifEnv* env,
+                        int domain, int type, int protocol,
+                        char* netns)
+{
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     res;
+    int              proto = protocol, save_errno = 0;
+    SOCKET           sock;
+    HANDLE           event;
+#ifdef HAVE_SETNS
+    int              current_ns = 0;
+#endif
+
+    SGDBG( ("SOCKET", "esock_open -> entry with"
+            "\r\n   domain:   %d"
+            "\r\n   type:     %d"
+            "\r\n   protocol: %d"
+            "\r\n   netns:    %s"
+            "\r\n", domain, type, protocol, ((netns == NULL) ? "NULL" : netns)) );
+
+#ifdef HAVE_SETNS
+    if ((netns != NULL) &&
+        !change_network_namespace(netns, &current_ns, &save_errno))
+        return esock_make_error_errno(env, save_errno);
+#endif
+
+    if ((sock = sock_open(domain, type, proto)) == INVALID_SOCKET)
+        return esock_make_error_errno(env, sock_errno());
+
+    SGDBG( ("SOCKET", "esock_open -> open success: %d\r\n", sock) );
+
+
+    /* NOTE that if the protocol = 0 (default) and the domain is not
+     * local (AF_LOCAL) we need to explicitly get the protocol here!
+     */
+    
+    if ((proto == 0)
+#if defined(AF_LOCAL)
+        && (domain != AF_LOCAL)
+#endif
+        )
+        if (!esock_open_which_protocol(sock, &proto)) {
+            if (proto == ESOCK_WHICH_PROTO_ERROR) {
+                save_errno = sock_errno();
+                while ((sock_close(sock) == INVALID_SOCKET) &&
+                       (sock_errno() == EINTR));
+                return esock_make_error_errno(env, save_errno);
+            } else {
+                while ((sock_close(sock) == INVALID_SOCKET) &&
+                       (sock_errno() == EINTR));
+                return esock_make_error(env, esock_atom_eafnosupport);
+            }
+        }
+
+
+#ifdef HAVE_SETNS
+    if ((netns != NULL) &&
+        !restore_network_namespace(current_ns, sock, &save_errno))
+        return esock_make_error_errno(env, save_errno);
+
+    if (netns != NULL)
+        FREE(netns);
+#endif
+
+
+    if ((event = sock_create_event(sock)) == INVALID_EVENT) {
+        save_errno = sock_errno();
+        while ((sock_close(sock) == INVALID_SOCKET) && (sock_errno() == EINTR));
+        return esock_make_error_errno(env, save_errno);
+    }
+
+    SGDBG( ("SOCKET", "esock_open -> event success: %d\r\n", event) );
+
+    SET_NONBLOCKING(sock);
+
+
+    /* Create and initiate the socket "descriptor" */
+    if ((descP = alloc_descriptor(sock, event)) == NULL) {
+        sock_close(sock);
+        // Not sure if this is really the proper error, but...
+        return enif_make_badarg(env);
+    }
+
+    descP->state    = ESOCK_STATE_OPEN;
+    descP->domain   = domain;
+    descP->type     = type;
+    descP->protocol = proto;
+
+    /* Does this apply to other types? Such as RAW?
+     * Also, is this really correct? Should we not wait for bind?
+     */
+    if (type == SOCK_DGRAM) {
+        descP->isReadable = TRUE;
+        descP->isWritable = TRUE;
+    }
+
+    /*
+     * Should we keep track of sockets (resources) in some way?
+     * Doing it here will require mutex to ensure data integrity,
+     * which will be costly. Send it somewhere?
+     */
+    res = enif_make_resource(env, descP);
+    enif_release_resource(descP);
+
+    /* Keep track of the creator
+     * This should not be a problem, but just in case
+     * the *open* function is used with the wrong kind
+     * of environment...
+     */
+    if (enif_self(env, &descP->ctrlPid) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    if (MONP("esock_open -> ctrl",
+             env, descP,
+             &descP->ctrlPid,
+             &descP->ctrlMon) != 0)
+        return esock_make_error(env, atom_exmon);
+
+
+    inc_socket(domain, type, protocol);
+
+    return esock_make_ok2(env, res);
+}
+
+
+static
+BOOLEAN_T esock_open_which_protocol(SOCKET sock, int* proto)
+{
+#if defined(SO_PROTOCOL)
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(sock, SOL_SOCKET, SO_PROTOCOL, &val, &valSz);
+
+    if (res != 0) {
+        *proto = ESOCK_WHICH_PROTO_ERROR;
+        return FALSE;
+    } else {
+        *proto = val;
+        return TRUE;
+    }
+#else
+    *proto = ESOCK_WHICH_PROTO_UNSUP;
+    return FALSE;
+#endif
+}
+
+
+#endif // if !defined(__WIN32__)
+
+
+
+#ifdef HAVE_SETNS
+/* We should really have another API, so that we can return errno... */
+
+/* *** change network namespace ***
+ * Retreive the current namespace and set the new.
+ * Return result and previous namespace if successfull.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T change_network_namespace(char* netns, int* cns, int* err)
+{
+    int save_errno;
+    int current_ns = 0;
+    int new_ns     = 0;
+
+    SGDBG( ("SOCKET", "change_network_namespace -> entry with"
+            "\r\n   new ns: %s", netns) );
+
+    if (netns != NULL) {
+        current_ns = open("/proc/self/ns/net", O_RDONLY);
+        if (current_ns == INVALID_SOCKET) {
+            *cns = current_ns;
+            *err = sock_errno();
+            return FALSE;
+        }
+        new_ns = open(netns, O_RDONLY);
+        if (new_ns == INVALID_SOCKET) {
+            save_errno = sock_errno();
+            while (close(current_ns) == INVALID_SOCKET &&
+                   sock_errno() == EINTR);
+            *cns = -1;
+            *err = save_errno;
+            return FALSE;
+        }
+        if (setns(new_ns, CLONE_NEWNET) != 0) {
+            save_errno = sock_errno();
+            while ((close(new_ns) == INVALID_SOCKET) &&
+                   (sock_errno() == EINTR));
+            while ((close(current_ns) == INVALID_SOCKET) &&
+                   (sock_errno() == EINTR));
+            *cns = -1;
+            *err = save_errno;
+            return FALSE;
+        } else {
+            while ((close(new_ns) == INVALID_SOCKET) &&
+                   (sock_errno() == EINTR));
+            *cns = current_ns;
+            *err = 0;
+            return TRUE;
+        }
+    } else {
+        *cns = INVALID_SOCKET;
+        *err = 0;
+        return TRUE;
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+/* *** restore network namespace ***
+ * Restore the previous namespace (see above).
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T restore_network_namespace(int ns, SOCKET sock, int* err)
+{
+    int save_errno;
+
+    SGDBG( ("SOCKET", "restore_network_namespace -> entry with"
+            "\r\n   ns: %d", ns) );
+
+    if (ns != INVALID_SOCKET) {
+        if (setns(ns, CLONE_NEWNET) != 0) {
+            /* XXX Failed to restore network namespace.
+             * What to do? Tidy up and return an error...
+             * Note that the thread now might still be in the namespace.
+             * Can this even happen? Should the emulator be aborted?
+             */
+            if (sock != INVALID_SOCKET)
+                save_errno = sock_errno();
+            while (close(sock) == INVALID_SOCKET &&
+                   sock_errno() == EINTR);
+            sock = INVALID_SOCKET;
+            while (close(ns) == INVALID_SOCKET &&
+                   sock_errno() == EINTR);
+            *err = save_errno;
+            return FALSE;
+        } else {
+            while (close(ns) == INVALID_SOCKET &&
+                   sock_errno() == EINTR);
+            *err = 0;
+            return TRUE;
+        }
+  }
+
+  *err = 0;
+  return TRUE;
+}
+#endif // if !defined(__WIN32__)
+#endif // ifdef HAVE_SETNS
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_bind
+ *
+ * Description:
+ * Bind a name to a socket.
+ *
+ * Arguments:
+ * [0] Socket (ref) - Points to the socket descriptor.
+ * [1] LocalAddr    - Local address is a sockaddr map ( socket:sockaddr() ).
+ */
+static
+ERL_NIF_TERM nif_bind(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     eSockAddr;
+    ESockAddress     sockAddr;
+    unsigned int     addrLen;
+    char*            xres;
+
+    SGDBG( ("SOCKET", "nif_bind -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 2) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    eSockAddr = argv[1];
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_bind -> args when sock = %d (0x%lX)"
+            "\r\n   Socket:   %T"
+            "\r\n   SockAddr: %T"
+            "\r\n", descP->sock, descP->state, argv[0], eSockAddr) );
+
+    /* Make sure we are ready
+     * Not sure how this would even happen, but...
+     */
+    if (descP->state != ESOCK_STATE_OPEN)
+        return esock_make_error(env, atom_exbadstate);
+
+    if ((xres = esock_decode_sockaddr(env, eSockAddr, &sockAddr, &addrLen)) != NULL)
+        return esock_make_error_str(env, xres);
+        
+    return esock_bind(env, descP, &sockAddr, addrLen);
+
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_bind(ErlNifEnv*       env,
+                        ESockDescriptor* descP,
+                        ESockAddress*    sockAddrP,
+                        unsigned int     addrLen)
+{
+    int port, ntohs_port;
+
+    SSDBG( descP, ("SOCKET", "esock_bind -> try bind\r\n") );
+
+    if (IS_SOCKET_ERROR(sock_bind(descP->sock,
+                                  (struct sockaddr*) sockAddrP, addrLen))) {
+        return esock_make_error_errno(env, sock_errno());
+    }
+
+    SSDBG( descP, ("SOCKET", "esock_bind -> bound - get port\r\n") );
+
+    port = which_address_port(sockAddrP);
+    SSDBG( descP, ("SOCKET", "esock_bind -> port: %d\r\n", port) );
+    if (port == 0) {
+        SOCKLEN_T len = sizeof(ESockAddress);
+        sys_memzero((char *) sockAddrP, len);
+        sock_name(descP->sock, &sockAddrP->sa, &len);
+        port = which_address_port(sockAddrP);
+    } else if (port == -1) {
+        port = 0;
+    }
+
+    ntohs_port = sock_ntohs(port);
+    
+    SSDBG( descP, ("SOCKET",
+                   "esock_bind -> done with port = %d\r\n", ntohs_port) );
+
+    return esock_make_ok2(env, MKI(env, ntohs_port));
+
+}
+#endif // if !defined(__WIN32__)
+
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_connect
+ *
+ * Description:
+ * Initiate a connection on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SockAddr     - Socket Address of "remote" host.
+ *                This is sockaddr(), which is either
+ *                sockaddr_in4 or sockaddr_in6.
+ */
+static
+ERL_NIF_TERM nif_connect(ErlNifEnv*         env,
+                         int                argc,
+                         const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     res, eSockAddr, sockRef;
+    char*            xres;
+
+    SGDBG( ("SOCKET", "nif_connect -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    sockRef = argv[0];
+    if ((argc != 2) ||
+        !ESOCK_GET_RESOURCE(env, sockRef, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    eSockAddr = argv[1];
+
+    SSDBG( descP,
+           ("SOCKET", "nif_connect -> args when sock = %d:"
+            "\r\n   Socket:   %T"
+            "\r\n   SockAddr: %T"
+            "\r\n", descP->sock, argv[0], eSockAddr) );
+    
+    if ((xres = esock_decode_sockaddr(env, eSockAddr,
+                                      &descP->remote,
+                                      &descP->addrLen)) != NULL) {
+        return esock_make_error_str(env, xres);
+    }
+
+
+    /* Only a *!%&$*# would send an opened but non-connected socket
+     * somewhere (before its actually usable), but just to be on the
+     * safe side we do the best we can to avoid complications...
+     */
+
+    MLOCK(descP->readMtx);
+    MLOCK(descP->writeMtx);
+    MLOCK(descP->cfgMtx);
+
+    res = esock_connect(env, descP, sockRef);
+
+    MUNLOCK(descP->cfgMtx);
+    MUNLOCK(descP->writeMtx);
+    MUNLOCK(descP->readMtx);
+
+    return res;
+
+#endif // if !defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_connect(ErlNifEnv*       env,
+                           ESockDescriptor* descP,
+                           ERL_NIF_TERM     sockRef)
+{
+    ERL_NIF_TERM res, ref;
+    int          code, sres, save_errno = 0;
+
+    /* 
+     * Verify that we are where in the proper state
+     */
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    if (!IS_OPEN(descP)) {
+        SSDBG( descP, ("SOCKET", "esock_connect -> not open\r\n") );
+        return esock_make_error(env, atom_exbadstate);
+    }
+
+    if (IS_CONNECTED(descP)) {
+        SSDBG( descP, ("SOCKET", "esock_connect -> already connected\r\n") );
+        return esock_make_error(env, atom_eisconn);
+    }
+
+    if (IS_CONNECTING(descP) && !is_connector(env, descP)) {
+        SSDBG( descP, ("SOCKET", "esock_connect -> already connecting\r\n") );
+        return esock_make_error(env, esock_atom_einval);
+    }
+    
+
+    /* 
+     * And attempt to connect
+     */
+
+    code = sock_connect(descP->sock,
+                        (struct sockaddr*) &descP->remote,
+                        descP->addrLen);
+    save_errno = sock_errno();
+
+    SSDBG( descP, ("SOCKET", "esock_connect -> connect result: %d, %d\r\n",
+                   code, save_errno) );
+
+    if (IS_SOCKET_ERROR(code)) {
+        switch (save_errno) {
+        case ERRNO_BLOCK:   /* Winsock2            */
+        case EINPROGRESS:   /* Unix & OSE!!        */
+            SSDBG( descP, ("SOCKET",
+                           "esock_connect -> would block => select\r\n") );
+
+            ref = MKREF(env);
+
+            if (IS_CONNECTING(descP)) {
+                /* Glitch */
+                res = esock_make_ok2(env, ref);
+            } else {
+
+                /* First time here */
+
+                if (enif_self(env, &descP->connPid) == NULL)
+                    return esock_make_error(env, atom_exself);
+
+                if (MONP("esock_connect -> conn",
+                         env, descP,
+                         &descP->connPid,
+                         &descP->connMon) != 0)
+                    return esock_make_error(env, atom_exmon);
+
+                descP->state = ESOCK_STATE_CONNECTING;
+
+                if ((sres = esock_select_write(env, descP->sock, descP, NULL,
+                                               sockRef, ref)) < 0) {
+                    res = esock_make_error(env,
+                                           MKT2(env,
+                                                esock_atom_select_failed,
+                                                MKI(env, sres)));
+                } else {
+                    res = esock_make_ok2(env, ref);
+                }
+            }
+            break;
+
+        case EISCONN:
+            SSDBG( descP, ("SOCKET",
+                           "esock_connect -> *already* connected\r\n") );
+            {
+                /* This is ***strange*** so make sure */
+                int err = 0;
+                if (!verify_is_connected(descP, &err)) {
+                    descP->state = ESOCK_STATE_OPEN;  /* restore state */
+                    res = esock_make_error_errno(env, err);
+                } else {
+                    descP->state = ESOCK_STATE_CONNECTED;
+                    /* And just to be on the safe side, reset these */
+                    enif_set_pid_undefined(&descP->connPid);
+                    DEMONP("esock_connect -> connected",
+                           env, descP, &descP->connMon);
+                    descP->isReadable = TRUE;
+                    descP->isWritable = TRUE;
+                    res = esock_atom_ok;
+                }
+            }
+            break;
+
+        default:
+            SSDBG( descP, ("SOCKET", "esock_connect -> other error(1): %d\r\n",
+                           save_errno) );
+            res = esock_make_error_errno(env, save_errno);
+            break;
+        }
+
+    } else if (code == 0) {                 /* ok we are connected */
+
+        SSDBG( descP, ("SOCKET", "esock_connect -> connected\r\n") );
+
+        descP->state      = ESOCK_STATE_CONNECTED;
+        enif_set_pid_undefined(&descP->connPid);
+        DEMONP("esock_connect -> connected", env, descP, &descP->connMon);
+        descP->isReadable = TRUE;
+        descP->isWritable = TRUE;
+
+        res = esock_atom_ok;
+
+    } else {
+        /* Do we really need this case? */
+
+        SSDBG( descP, ("SOCKET", "esock_connect -> other error(2): %d\r\n",
+                       save_errno) );
+
+        res = esock_make_error_errno(env, save_errno);
+    }
+
+    return res;
+
+}
+#endif // if !defined(__WIN32__)
+
+
+/* ----------------------------------------------------------------------
+ * nif_finalize_connection
+ *
+ * Description:
+ * Make socket ready for input and output.
+ * This function is called if we where made to wait when we called the
+ * nif_connect function (we made a select, and the select message has
+ * now been received).
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+static
+ERL_NIF_TERM nif_finalize_connection(ErlNifEnv*         env,
+                                     int                argc,
+                                     const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    return esock_finalize_connection(env, descP);
+
+#endif
+}
+
+
+/* *** esock_finalize_connection ***
+ * Perform the final check to verify a connection.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_finalize_connection(ErlNifEnv*       env,
+                                       ESockDescriptor* descP)
+{
+    int error;
+
+    if (!IS_CONNECTING(descP))
+        return esock_make_error(env, atom_enotconn);
+
+    if (!verify_is_connected(descP, &error)) {
+        descP->state = ESOCK_STATE_OPEN;  /* restore state */
+        return esock_make_error_errno(env, error);
+    }
+
+    descP->state      = ESOCK_STATE_CONNECTED;
+    enif_set_pid_undefined(&descP->connPid);
+    DEMONP("esock_finalize_connection -> connected",
+           env, descP, &descP->connMon);
+    descP->isReadable = TRUE;
+    descP->isWritable = TRUE;
+
+    return esock_atom_ok;
+}
+#endif
+
+
+/* *** verify_is_connected ***
+ * Check if a connection has been established.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T verify_is_connected(ESockDescriptor* descP, int* err)
+{
+    /*
+     * *** This is strange ***
+     *
+     * This *should* work on Windows NT too, but doesn't.
+     * An bug in Winsock 2.0 for Windows NT?
+     *
+     * See "Unix Netwok Programming", W.R.Stevens, p 412 for a
+     * discussion about Unix portability and non blocking connect.
+     */
+
+#ifndef SO_ERROR
+    
+    int sz, code;
+
+    sz = sizeof(descP->remote);
+    sys_memzero((char *) &descP->remote, sz);
+    code = sock_peer(desc->sock,
+                     (struct sockaddr*) &descP->remote, &sz);
+
+    if (IS_SOCKET_ERROR(code)) {
+        *err = sock_errno();
+        return FALSE;
+    }
+
+#else
+
+    int          error = 0;             /* Has to be initiated, we check it */
+    unsigned int sz    = sizeof(error); /* even if we get -1                */
+    int          code  = sock_getopt(descP->sock,
+                                     SOL_SOCKET, SO_ERROR,
+                                     (void *)&error, &sz);
+
+    if ((code < 0) || error) {
+        *err = error;
+        return FALSE;
+    }
+
+#endif /* SO_ERROR */
+
+    *err = 0;
+
+    return TRUE;
+}
+#endif
+
+
+
+/* *** is_connector ***
+ * Check if the current process is the connector process.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T is_connector(ErlNifEnv*       env,
+                       ESockDescriptor* descP)
+{
+    ErlNifPid caller;
+
+    if (enif_self(env, &caller) == NULL)
+        return FALSE;
+
+    if (COMPARE_PIDS(&descP->connPid, &caller) == 0)
+        return TRUE;
+    else
+        return FALSE;
+    
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_listen
+ *
+ * Description:
+ * Listen for connections on a socket.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * Backlog      - The maximum length to which the queue of pending
+ *                connections for socket may grow.
+ */
+static
+ERL_NIF_TERM nif_listen(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    int              backlog;
+
+    SGDBG( ("SOCKET", "nif_listen -> entry with argc: %d\r\n", argc) );
+    
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 2) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP) ||
+        !GET_INT(env, argv[1], &backlog)) {
+        return enif_make_badarg(env);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nif_listen -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   backlog: %d"
+            "\r\n", descP->sock, argv[0], backlog) );
+    
+    return esock_listen(env, descP, backlog);
+
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_listen(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          int              backlog)
+{
+    
+    /* 
+     * Verify that we are where in the proper state
+     */
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    if (descP->state == ESOCK_STATE_CLOSED)
+        return esock_make_error(env, atom_exbadstate);
+
+    if (!IS_OPEN(descP))
+        return esock_make_error(env, atom_exbadstate);
+
+
+    /* 
+     * And attempt to make socket listening
+     */
+    
+    if (IS_SOCKET_ERROR(sock_listen(descP->sock, backlog)))
+        return esock_make_error_errno(env, sock_errno());
+
+    descP->state = ESOCK_STATE_LISTENING;
+
+    return esock_atom_ok;
+
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_accept
+ *
+ * Description:
+ * Accept a connection on a socket.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * Request ref  - Unique "id" of this request
+ *                (used for the select, if none is in queue).
+ */
+static
+ERL_NIF_TERM nif_accept(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     sockRef, ref, res;
+
+    SGDBG( ("SOCKET", "nif_accept -> entry with argc: %d\r\n", argc) );
+    
+    /* Extract arguments and perform preliminary validation */
+
+    sockRef = argv[0];
+    if ((argc != 2) ||
+        !ESOCK_GET_RESOURCE(env, sockRef, (void**) &descP)) {
+        return enif_make_badarg(env); 
+    }
+    ref = argv[1];
+    
+    MLOCK(descP->accMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "nif_accept -> args when sock = %d:"
+            "\r\n   Socket:                %T"
+            "\r\n   ReqRef:                %T"
+            "\r\nwhen"
+            "\r\n   State:                 %s"
+            "\r\n   Current Acceptor Addr: 0x%lX"
+            "\r\n   Current Acceptor pid:  %T"
+            "\r\n   Current Acceptor mon:  %T"
+            "\r\n   Current Acceptor env:  0x%lX"
+            "\r\n   Current Acceptor ref:  %T"
+            "\r\n",
+            descP->sock,
+            sockRef, ref,
+            ((descP->state == ESOCK_STATE_LISTENING) ? "listening" :
+             ((descP->state == ESOCK_STATE_ACCEPTING) ? "accepting" : "other")),
+            descP->currentAcceptorP,
+            descP->currentAcceptor.pid,
+            esock_make_monitor_term(env, &descP->currentAcceptor.mon),
+            descP->currentAcceptor.env,
+            descP->currentAcceptor.ref) );
+
+    res = esock_accept(env, descP, sockRef, ref);
+
+    MUNLOCK(descP->accMtx);
+
+    return res;
+
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_accept(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          ERL_NIF_TERM     sockRef,
+                          ERL_NIF_TERM     ref)
+{
+    ERL_NIF_TERM res;
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    switch (descP->state) {
+    case ESOCK_STATE_LISTENING:
+        res = esock_accept_listening(env, descP, sockRef, ref);
+        break;
+
+    case ESOCK_STATE_ACCEPTING:
+        res = esock_accept_accepting(env, descP, sockRef, ref);
+        break;
+
+    default:
+        res = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return res;
+}
+#endif // if !defined(__WIN32__)
+
+
+/* *** esock_accept_listening ***
+ *
+ * We have no active acceptor (and therefor no acceptors in queue).
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_accept_listening(ErlNifEnv*       env,
+                                    ESockDescriptor* descP,
+                                    ERL_NIF_TERM     sockRef,
+                                    ERL_NIF_TERM     accRef)
+{
+    ESockAddress  remote;
+    unsigned int  n;
+    SOCKET        accSock;
+    int           save_errno;
+    ErlNifPid     caller;
+    ERL_NIF_TERM  res;
+
+    SSDBG( descP, ("SOCKET", "esock_accept_listening -> get caller\r\n") );
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    n = sizeof(remote);
+    sys_memzero((char *) &remote, n);
+    SSDBG( descP, ("SOCKET", "esock_accept_listening -> try accept\r\n") );
+    accSock = sock_accept(descP->sock, (struct sockaddr*) &remote, &n);
+    if (accSock == INVALID_SOCKET) {
+
+        save_errno = sock_errno();
+
+        SSDBG( descP,
+               ("SOCKET",
+                "esock_accept_listening -> accept failed (%d)\r\n",
+                save_errno) );
+
+        res = esock_accept_listening_error(env, descP, sockRef, accRef,
+                                           caller, save_errno);
+
+    } else {
+
+        /*
+         * We got one
+         */
+
+        SSDBG( descP, ("SOCKET", "esock_accept_listening -> success\r\n") );
+
+        res = esock_accept_listening_accept(env, descP, accSock, caller, &remote);
+
+    }
+
+    return res;
+}
+
+
+/* *** esock_accept_listening_error ***
+ *
+ * The accept call resultet in an error - handle it.
+ * There are only two cases: 
+ * 1) BLOCK => Attempt a "retry"
+ * 2) Other => Return the value (converted to an atom)
+ */
+static
+ERL_NIF_TERM esock_accept_listening_error(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     sockRef,
+                                          ERL_NIF_TERM     accRef,
+                                          ErlNifPid        caller,
+                                          int              save_errno)
+{
+    ERL_NIF_TERM res;
+
+    if (save_errno == ERRNO_BLOCK) {
+
+        /* *** Try again later *** */
+
+        SSDBG( descP,
+               ("SOCKET", "esock_accept_listening_error -> would block\r\n") );
+
+        descP->currentAcceptor.pid = caller;
+        if (MONP("esock_accept_listening -> current acceptor",
+                 env, descP,
+                 &descP->currentAcceptor.pid,
+                 &descP->currentAcceptor.mon) != 0) {
+            enif_set_pid_undefined(&descP->currentAcceptor.pid);
+            res = esock_make_error(env, atom_exmon);
+        } else {
+            ESOCK_ASSERT(!descP->currentAcceptor.env);
+            descP->currentAcceptor.env = esock_alloc_env("current acceptor");
+            descP->currentAcceptor.ref = CP_TERM(descP->currentAcceptor.env,
+                                                 accRef);
+            descP->currentAcceptorP    = &descP->currentAcceptor;
+            res = esock_accept_busy_retry(env, descP,
+                                          sockRef, accRef,
+                                          NULL, ESOCK_STATE_ACCEPTING);
+        }
+    } else {
+        SSDBG( descP,
+               ("SOCKET",
+                "esock_accept_listening -> errno: %d\r\n", save_errno) );
+        res = esock_make_error_errno(env, save_errno);
+    }
+
+    return res;
+}
+
+
+/* *** esock_accept_listening_accept ***
+ *
+ * The accept call was successful (accepted) - handle the new connection.
+ */
+static
+ERL_NIF_TERM esock_accept_listening_accept(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           SOCKET           accSock,
+                                           ErlNifPid        caller,
+                                           ESockAddress*    remote)
+{
+    ERL_NIF_TERM res;
+
+    esock_accept_accepted(env, descP, accSock, caller, remote, &res);
+    
+    return res;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* *** esock_accept_accepting ***
+ *
+ * We have an active acceptor and possibly acceptors waiting in queue.
+ * If the pid of the calling process is not the pid of the "current process",
+ * push the requester onto the (acceptor) queue.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_accept_accepting(ErlNifEnv*       env,
+                                    ESockDescriptor* descP,
+                                    ERL_NIF_TERM     sockRef,
+                                    ERL_NIF_TERM     ref)
+{
+    ErlNifPid     caller;
+    ERL_NIF_TERM  res;
+
+    SSDBG( descP, ("SOCKET", "esock_accept_accepting -> get caller\r\n") );
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    SSDBG( descP, ("SOCKET", "esock_accept_accepting -> check: "
+                   "are caller current acceptor:"
+                   "\r\n   Caller:  %T"
+                   "\r\n   Current: %T"
+                   "\r\n", caller, descP->currentAcceptor.pid) );
+
+    if (COMPARE_PIDS(&descP->currentAcceptor.pid, &caller) == 0) {
+
+        SSDBG( descP,
+               ("SOCKET", "esock_accept_accepting -> current acceptor\r\n") );
+
+        res = esock_accept_accepting_current(env, descP, sockRef, ref);
+
+    } else {
+
+        /* Not the "current acceptor", so (maybe) push onto queue */
+
+        SSDBG( descP,
+               ("SOCKET",
+                "esock_accept_accepting -> *not* current acceptor\r\n") );
+
+        res = esock_accept_accepting_other(env, descP, ref, caller);
+
+    }
+
+    return res;
+
+}
+
+
+
+/* *** esock_accept_accepting_current ***
+ * Handles when the current acceptor makes another attempt.
+ */
+static
+ERL_NIF_TERM esock_accept_accepting_current(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     sockRef,
+                                            ERL_NIF_TERM     accRef)
+{
+    ESockAddress  remote;
+    unsigned int  n;
+    SOCKET        accSock;
+    int           save_errno;
+    ERL_NIF_TERM  res;
+
+    SSDBG( descP, ("SOCKET",
+                   "esock_accept_accepting_current -> try accept\r\n") );
+    n = sizeof(descP->remote);
+    sys_memzero((char *) &remote, n);
+    accSock = sock_accept(descP->sock, (struct sockaddr*) &remote, &n);
+    if (accSock == INVALID_SOCKET) {
+
+        save_errno = sock_errno();
+
+        SSDBG( descP,
+               ("SOCKET",
+                "esock_accept_accepting_current -> accept failed: %d\r\n",
+                save_errno) );
+
+        res = esock_accept_accepting_current_error(env, descP, sockRef,
+                                                   accRef, save_errno);
+                                              
+    } else {
+
+        SSDBG( descP, ("SOCKET",
+                       "esock_accept_accepting_current -> accepted\r\n") );
+        
+        res = esock_accept_accepting_current_accept(env, descP, sockRef,
+                                                    accSock, &remote);
+
+    }
+
+    return res;
+}
+
+
+/* *** esock_accept_accepting_current_accept ***
+ * Handles when the current acceptor succeeded in its accept call - 
+ * handle the new connection.
+ */
+static
+ERL_NIF_TERM esock_accept_accepting_current_accept(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     sockRef,
+                                                   SOCKET           accSock,
+                                                   ESockAddress*    remote)
+{
+    ERL_NIF_TERM res;
+
+    if (esock_accept_accepted(env, descP, accSock,
+                              descP->currentAcceptor.pid, remote, &res)) {
+
+        /* Clean out the old cobweb's before trying to invite a new spider */
+
+        descP->currentAcceptor.ref = esock_atom_undefined;
+        enif_set_pid_undefined(&descP->currentAcceptor.pid);
+        esock_free_env("esock_accept_accepting_current_accept - "
+                       "current-accept-env",
+                       descP->currentAcceptor.env);
+        descP->currentAcceptor.env =  NULL;
+
+        if (!activate_next_acceptor(env, descP, sockRef)) {
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "esock_accept_accepting_current_accept -> "
+                    "no more writers\r\n") );
+
+            descP->state               = ESOCK_STATE_LISTENING;
+
+            descP->currentAcceptorP    = NULL;
+            ESOCK_ASSERT(!descP->currentAcceptor.env);
+            descP->currentAcceptor.env = NULL;
+            MON_INIT(&descP->currentAcceptor.mon);
+        }
+
+    }
+
+    return res;
+}
+
+
+/* *** esock_accept_accepting_current_error ***
+ * The accept call of current acceptor resultet in an error - handle it.
+ * There are only two cases: 
+ * 1) BLOCK => Attempt a "retry"
+ * 2) Other => Return the value (converted to an atom)
+ */
+static
+ERL_NIF_TERM esock_accept_accepting_current_error(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     sockRef,
+                                                  ERL_NIF_TERM     opRef,
+                                                  int              save_errno)
+{
+    ESockRequestor req;
+    ERL_NIF_TERM   res, reason;
+
+    req.env = NULL;
+    if (save_errno == ERRNO_BLOCK) {
+
+        /*
+         * Just try again, no real error, just a ghost trigger from poll,
+         */
+
+        SSDBG( descP,
+               ("SOCKET",
+                "esock_accept_accepting_current_error -> "
+                "would block: try again\r\n") );
+
+        res = esock_accept_busy_retry(env, descP, sockRef, opRef,
+                                      &descP->currentAcceptor.pid,
+                                      /* No state change */
+                                      descP->state);
+
+    } else {
+
+        reason = MKA(env, erl_errno_id(save_errno));
+        res    = esock_make_error(env, reason);
+
+        while (acceptor_pop(env, descP, &req)) {
+            SSDBG( descP,
+                   ("SOCKET",
+                    "esock_accept_accepting_current_error -> abort %T\r\n",
+                    req.pid) );
+            esock_send_abort_msg(env, sockRef, req.ref, req.env,
+                                 reason, &req.pid);
+            req.env = NULL;
+            DEMONP("esock_accept_accepting_current_error -> pop'ed writer",
+                   env, descP, &req.mon);
+        }
+
+    }
+
+    return res;
+}
+
+
+/* *** esock_accept_accepting_other ***
+ * Handles when the another acceptor makes an attempt, which
+ * results (maybe) in the request beeing pushed onto the 
+ * acceptor queue.
+ */
+static
+ERL_NIF_TERM esock_accept_accepting_other(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     ref,
+                                          ErlNifPid        caller)
+{
+    ERL_NIF_TERM  result;
+
+    if (!acceptor_search4pid(env, descP, &caller)) // Ugh! (&caller)
+        result = acceptor_push(env, descP, caller, ref);
+    else
+        result = esock_make_error(env, esock_atom_eagain);
+    
+    return result;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* *** esock_accept_busy_retry ***
+ *
+ * Perform a retry select. If successful, set nextState.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_accept_busy_retry(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     ERL_NIF_TERM     sockRef,
+                                     ERL_NIF_TERM     accRef,
+                                     ErlNifPid*       pid,
+                                     unsigned int     nextState)
+{
+    int          sres;
+    ERL_NIF_TERM res, reason;
+
+    if ((sres = esock_select_read(env, descP->sock, descP, pid,
+                                  sockRef, accRef)) < 0) {
+        reason = MKT2(env, esock_atom_select_failed, MKI(env, sres));
+        res    = esock_make_error(env, reason);
+    } else {
+        descP->state = nextState;
+        res          = esock_make_error(env, esock_atom_eagain); // OK!!
+    }
+
+    return res;
+}
+
+
+
+/* *** esock_accept_accepted ***
+ *
+ * Generic function handling a successful accept.
+ */
+static
+BOOLEAN_T esock_accept_accepted(ErlNifEnv*       env,
+                                ESockDescriptor* descP,
+                                SOCKET           accSock,
+                                ErlNifPid        pid,
+                                ESockAddress*    remote,
+                                ERL_NIF_TERM*    result)
+{
+    ESockDescriptor* accDescP;
+    HANDLE           accEvent;
+    ERL_NIF_TERM     accRef;
+    int              save_errno;
+
+    /*
+     * We got one
+     */
+
+    if ((accEvent = sock_create_event(accSock)) == INVALID_EVENT) {
+        save_errno = sock_errno();
+        while ((sock_close(accSock) == INVALID_SOCKET) &&
+               (sock_errno() == EINTR));
+        *result = esock_make_error_errno(env, save_errno);
+        return FALSE;
+    }
+
+    if ((accDescP = alloc_descriptor(accSock, accEvent)) == NULL) {
+        sock_close(accSock);
+        *result = enif_make_badarg(env);
+        return FALSE;
+    }
+
+    accDescP->domain   = descP->domain;
+    accDescP->type     = descP->type;
+    accDescP->protocol = descP->protocol;
+    accDescP->rBufSz   = descP->rBufSz;  // Inherit buffer size
+    accDescP->rNum     = descP->rNum;    // Inherit buffer uses
+    accDescP->rNumCnt  = 0;
+    accDescP->rCtrlSz  = descP->rCtrlSz; // Inherit buffer size
+    accDescP->wCtrlSz  = descP->wCtrlSz; // Inherit buffer size
+
+    accRef = enif_make_resource(env, accDescP);
+    enif_release_resource(accDescP);
+
+    accDescP->ctrlPid = pid;
+    if (MONP("esock_accept_accepted -> ctrl",
+             env, accDescP,
+             &accDescP->ctrlPid,
+             &accDescP->ctrlMon) != 0) {
+        sock_close(accSock);
+        enif_set_pid_undefined(&descP->ctrlPid);
+        *result = esock_make_error(env, atom_exmon);
+        return FALSE;
+    }
+
+    accDescP->remote = *remote;
+    SET_NONBLOCKING(accDescP->sock);
+
+    accDescP->state      = ESOCK_STATE_CONNECTED;
+    accDescP->isReadable = TRUE;
+    accDescP->isWritable = TRUE;
+
+    *result = esock_make_ok2(env, accRef);
+
+    return TRUE;
+    
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_send
+ *
+ * Description:
+ * Send a message on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SendRef      - A unique id for this (send) request.
+ * Data         - The data to send in the form of a IOVec.
+ * Flags        - Send flags.
+ */
+
+static
+ERL_NIF_TERM nif_send(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     sockRef, sendRef;
+    ErlNifBinary     sndData;
+    unsigned int     eflags;
+    int              flags;
+    ERL_NIF_TERM     res;
+
+    SGDBG( ("SOCKET", "nif_send -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 4) ||
+        !GET_BIN(env, argv[2], &sndData) ||
+        !GET_UINT(env, argv[3], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we send in case we send abort
+    sendRef = argv[1];
+
+    if (!ESOCK_GET_RESOURCE(env, sockRef, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nif_send -> args when sock = %d:"
+            "\r\n   Socket:       %T"
+            "\r\n   SendRef:      %T"
+            "\r\n   Size of data: %d"
+            "\r\n   eFlags:       %d"
+            "\r\n", descP->sock, sockRef, sendRef, sndData.size, eflags) );
+
+    if (!esendflags2sendflags(eflags, &flags))
+        return enif_make_badarg(env);
+
+    MLOCK(descP->writeMtx);
+
+    /* We need to handle the case when another process tries
+     * to write at the same time.
+     * If the current write could not write its entire package
+     * this time (resulting in an select). The write of the
+     * other process must be made to wait until current
+     * is done!
+     */
+
+    res = esock_send(env, descP, sockRef, sendRef, &sndData, flags);
+
+    MUNLOCK(descP->writeMtx);
+
+    return res;
+
+#endif // if defined(__WIN32__)
+}
+
+
+
+/* *** esock_send ***
+ *
+ * Do the actual send.
+ * Do some initial writer checks, do the actual send and then
+ * analyze the result. If we are done, another writer may be
+ * scheduled (if there is one in the writer queue).
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_send(ErlNifEnv*       env,
+                        ESockDescriptor* descP,
+                        ERL_NIF_TERM     sockRef,
+                        ERL_NIF_TERM     sendRef,
+                        ErlNifBinary*    sndDataP,
+                        int              flags)
+{
+    int          save_errno;
+    ssize_t      written;
+    ERL_NIF_TERM writerCheck;
+
+    if (!descP->isWritable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current writer and if its us */
+    if (!send_check_writer(env, descP, sendRef, &writerCheck))
+        return writerCheck;
+    
+    /* We ignore the wrap for the moment.
+     * Maybe we should issue a wrap-message to controlling process...
+     */
+    // cnt_inc(&descP->writeTries, 1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_write_tries, &descP->writeTries, 1);
+
+    written = sock_send(descP->sock, sndDataP->data, sndDataP->size, flags);
+    if (IS_SOCKET_ERROR(written))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // The value does not actually matter in this case
+    
+    return send_check_result(env, descP,
+                             written, sndDataP->size, save_errno,
+                             sockRef, sendRef);
+
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_sendto
+ *
+ * Description:
+ * Send a message on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SendRef      - A unique id for this (send) request.
+ * Data         - The data to send in the form of a IOVec.
+ * Dest         - Destination (socket) address.
+ * Flags        - Send flags.
+ */
+
+static
+ERL_NIF_TERM nif_sendto(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     sockRef, sendRef;
+    ErlNifBinary     sndData;
+    unsigned int     eflags;
+    int              flags;
+    ERL_NIF_TERM     eSockAddr;
+    ESockAddress     remoteAddr;
+    unsigned int     remoteAddrLen;
+    char*            xres;
+    ERL_NIF_TERM     res;
+
+    SGDBG( ("SOCKET", "nif_sendto -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 5) ||
+        !GET_BIN(env, argv[2], &sndData) ||
+        !GET_UINT(env, argv[4], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef   = argv[0]; // We need this in case we send abort (to the caller)
+    sendRef   = argv[1];
+    eSockAddr = argv[3];
+
+    if (!ESOCK_GET_RESOURCE(env, sockRef, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_sendto -> args when sock = %d:"
+            "\r\n   Socket:       %T"
+            "\r\n   sendRef:      %T"
+            "\r\n   size of data: %d"
+            "\r\n   eSockAddr:    %T"
+            "\r\n   eflags:       %d"
+            "\r\n",
+            descP->sock, sockRef, sendRef, sndData.size, eSockAddr, eflags) );
+
+    if (!esendflags2sendflags(eflags, &flags)) {
+        SSDBG( descP, ("SOCKET", "nif_sendto -> sendflags decode failed\r\n") );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if ((xres = esock_decode_sockaddr(env, eSockAddr,
+                                      &remoteAddr,
+                                      &remoteAddrLen)) != NULL) {
+        SSDBG( descP,
+               ("SOCKET", "nif_sendto -> sockaddr decode: %s\r\n", xres) );
+        return esock_make_error_str(env, xres);
+    }
+
+    MLOCK(descP->writeMtx);
+
+    res = esock_sendto(env, descP, sockRef, sendRef, &sndData, flags,
+                       &remoteAddr, remoteAddrLen);
+
+    MUNLOCK(descP->writeMtx);
+
+    SGDBG( ("SOCKET", "nif_sendto -> done with result: "
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_sendto(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          ERL_NIF_TERM     sockRef,
+                          ERL_NIF_TERM     sendRef,
+                          ErlNifBinary*    dataP,
+                          int              flags,
+                          ESockAddress*    toAddrP,
+                          unsigned int     toAddrLen)
+{
+    int          save_errno;
+    ssize_t      written;
+    ERL_NIF_TERM writerCheck;
+
+    if (!descP->isWritable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current writer and if its us */
+    if (!send_check_writer(env, descP, sendRef, &writerCheck))
+        return writerCheck;
+    
+    /* We ignore the wrap for the moment.
+     * Maybe we should issue a wrap-message to controlling process...
+     */
+    // cnt_inc(&descP->writeTries, 1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_write_tries, &descP->writeTries, 1);
+
+    if (toAddrP != NULL) {
+        written = sock_sendto(descP->sock,
+                              dataP->data, dataP->size, flags,
+                              &toAddrP->sa, toAddrLen);
+    } else {
+        written = sock_sendto(descP->sock,
+                              dataP->data, dataP->size, flags,
+                              NULL, 0);
+    }
+    if (IS_SOCKET_ERROR(written))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // The value does not actually matter in this case
+
+    return send_check_result(env, descP, written, dataP->size, save_errno,
+                             sockRef, sendRef);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_sendmsg
+ *
+ * Description:
+ * Send a message on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SendRef      - A unique id for this (send) request.
+ * MsgHdr       - Message Header - data and (maybe) control and dest
+ * Flags        - Send flags.
+ */
+
+static
+ERL_NIF_TERM nif_sendmsg(ErlNifEnv*         env,
+                         int                argc,
+                         const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ERL_NIF_TERM     res, sockRef, sendRef, eMsgHdr;
+    ESockDescriptor* descP;
+    unsigned int     eflags;
+    int              flags;
+
+    SGDBG( ("SOCKET", "nif_sendmsg -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 4) ||
+        !IS_MAP(env, argv[2]) ||
+        !GET_UINT(env, argv[3], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we send abort (to the caller)
+    sendRef = argv[1];
+    eMsgHdr = argv[2];
+
+    if (!ESOCK_GET_RESOURCE(env, sockRef, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_sendmsg -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   sendRef: %T"
+            "\r\n   eflags:  %d"
+            "\r\n",
+            descP->sock, argv[0], sendRef, eflags) );
+
+    if (!esendflags2sendflags(eflags, &flags))
+        return esock_make_error(env, esock_atom_einval);
+
+    MLOCK(descP->writeMtx);
+
+    res = esock_sendmsg(env, descP, sockRef, sendRef, eMsgHdr, flags);
+
+    MUNLOCK(descP->writeMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "nif_sendmsg -> done with result: "
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_sendmsg(ErlNifEnv*       env,
+                           ESockDescriptor* descP,
+                           ERL_NIF_TERM     sockRef,
+                           ERL_NIF_TERM     sendRef,
+                           ERL_NIF_TERM     eMsgHdr,
+                           int              flags)
+{
+    ERL_NIF_TERM  res, eAddr, eIOV, eCtrl;
+    ESockAddress  addr;
+    struct msghdr msgHdr;
+    ErlNifBinary* iovBins;
+    struct iovec* iov;
+    unsigned int  iovLen;
+    char*         ctrlBuf;
+    size_t        ctrlBufLen, ctrlBufUsed;
+    int           save_errno;
+    ssize_t       written, dataSize;
+    ERL_NIF_TERM  writerCheck;
+    char*         xres;
+
+    if (!descP->isWritable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current writer and if its us */
+    if (!send_check_writer(env, descP, sendRef, &writerCheck))
+        return writerCheck;
+    
+    /* Depending on if we are *connected* or not, we require
+     * different things in the msghdr map.
+     */
+    if (IS_CONNECTED(descP)) {
+
+        /* We don't need the address */
+
+        SSDBG( descP, ("SOCKET",
+                       "esock_sendmsg -> connected: no address\r\n") );
+
+        msgHdr.msg_name    = NULL;
+        msgHdr.msg_namelen = 0;
+        
+    } else {
+
+        /* We need the address */
+
+        msgHdr.msg_name    = (void*) &addr;
+        msgHdr.msg_namelen = sizeof(addr);
+        sys_memzero((char *) msgHdr.msg_name, msgHdr.msg_namelen);
+        if (!GET_MAP_VAL(env, eMsgHdr, esock_atom_addr, &eAddr))
+            return esock_make_error(env, esock_atom_einval);
+
+        SSDBG( descP, ("SOCKET", "esock_sendmsg -> not connected: "
+                       "\r\n   address: %T"
+                       "\r\n", eAddr) );
+
+        if ((xres = esock_decode_sockaddr(env, eAddr,
+                                          msgHdr.msg_name,
+                                          &msgHdr.msg_namelen)) != NULL)
+            return esock_make_error_str(env, xres);
+    }
+
+
+    /* Extract the (other) attributes of the msghdr map: iov and maybe ctrl */
+
+    /* The *mandatory* iov, which must be a list */
+    if (!GET_MAP_VAL(env, eMsgHdr, esock_atom_iov, &eIOV))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_LIST_LEN(env, eIOV, &iovLen) && (iovLen > 0))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP, ("SOCKET", "esock_sendmsg -> iov length: %d\r\n", iovLen) );
+
+    iovBins = MALLOC(iovLen * sizeof(ErlNifBinary));
+    ESOCK_ASSERT( (iovBins != NULL) );
+
+    iov     = MALLOC(iovLen * sizeof(struct iovec));
+    ESOCK_ASSERT( (iov != NULL) );
+
+    /* The *opional* ctrl */
+    if (GET_MAP_VAL(env, eMsgHdr, esock_atom_ctrl, &eCtrl)) {
+        ctrlBufLen = descP->wCtrlSz;
+        ctrlBuf    = (char*) MALLOC(ctrlBufLen);
+        ESOCK_ASSERT( (ctrlBuf != NULL) );
+    } else {
+        eCtrl      = esock_atom_undefined;
+        ctrlBufLen = 0;
+        ctrlBuf    = NULL;
+    }
+    SSDBG( descP, ("SOCKET", "esock_sendmsg -> optional ctrl: "
+                   "\r\n   ctrlBuf:    0x%lX"
+                   "\r\n   ctrlBufLen: %d"
+                   "\r\n   eCtrl:      %T\r\n", ctrlBuf, ctrlBufLen, eCtrl) );
+    
+    /* Decode the iov and initiate that part of the msghdr */
+    if ((xres = esock_decode_iov(env, eIOV,
+                                 iovBins, iov, iovLen, &dataSize)) != NULL) {
+        FREE(iovBins);
+        FREE(iov);
+        if (ctrlBuf != NULL) FREE(ctrlBuf);
+        return esock_make_error_str(env, xres);
+    }
+    msgHdr.msg_iov    = iov;
+    msgHdr.msg_iovlen = iovLen;
+    
+
+    SSDBG( descP, ("SOCKET",
+                   "esock_sendmsg -> "
+                   "total (iov) data size: %d\r\n", dataSize) );
+
+
+    /* Decode the ctrl and initiate that part of the msghdr.
+     */
+    if (ctrlBuf != NULL) {
+        if ((xres = decode_cmsghdrs(env, descP,
+                                    eCtrl,
+                                    ctrlBuf, ctrlBufLen, &ctrlBufUsed)) != NULL) {
+            FREE(iovBins);
+            FREE(iov);
+            if (ctrlBuf != NULL) FREE(ctrlBuf);
+            return esock_make_error_str(env, xres);
+        }
+    } else {
+        ctrlBufUsed = 0;
+    }
+    msgHdr.msg_control    = ctrlBuf;
+    msgHdr.msg_controllen = ctrlBufUsed;
+    
+
+    /* The msg-flags field is not used when sending, but zero it just in case */
+    msgHdr.msg_flags      = 0;
+    
+
+    /* We ignore the wrap for the moment.
+     * Maybe we should issue a wrap-message to controlling process...
+     */
+    // cnt_inc(&descP->writeTries, 1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_write_tries, &descP->writeTries, 1);
+
+    /* And now, finally, try to send the message */
+    written = sock_sendmsg(descP->sock, &msgHdr, flags);
+
+    if (IS_SOCKET_ERROR(written))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // OK or not complete: this value should not matter in this case
+
+    res = send_check_result(env, descP, written, dataSize, save_errno,
+                            sockRef, sendRef);
+
+    FREE(iovBins);
+    FREE(iov);
+    if (ctrlBuf != NULL) FREE(ctrlBuf);
+    
+    return res;
+
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_writev / nif_sendv
+ *
+ * Description:
+ * Send a message (vector) on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SendRef      - A unique id for this (send) request.
+ * Data         - A vector of binaries
+ * Flags        - Send flags.
+ */
+
+#ifdef FOBAR
+static
+ERL_NIF_TERM nwritev(ErlNifEnv*       env,
+                     ESockDescriptor* descP,
+                     ERL_NIF_TERM     sendRef,
+                     ERL_NIF_TERM     data)
+{
+    ERL_NIF_TERM tail;
+    ErlNifIOVec  vec;
+    ErlNifIOVec* iovec = &vec;
+    SysIOVec*    sysiovec;
+    int          save_errno;
+    int          iovcnt, n;
+
+    if (!enif_inspect_iovec(env, MAX_VSZ, data, &tail, &iovec))
+        return enif_make_badarg(env);
+
+    if (enif_ioq_size(descP->outQ) > 0) {
+        /* If the I/O queue contains data we enqueue the iovec
+         * and then peek the data to write out of the queue.
+         */
+        if (!enif_ioq_enqv(q, iovec, 0))
+            return -3;
+
+        sysiovec = enif_ioq_peek(descP->outQ, &iovcnt);
+
+    } else {
+        /* If the I/O queue is empty we skip the trip through it. */
+        iovcnt   = iovec->iovcnt;
+        sysiovec = iovec->iov;
+    }
+
+    /* Attempt to write the data */
+    n = writev(fd, sysiovec, iovcnt);
+    saved_errno = errno;
+
+    if (enif_ioq_size(descP->outQ) == 0) {
+        /* If the I/O queue was initially empty we enqueue any
+           remaining data into the queue for writing later. */
+        if (n >= 0 && !enif_ioq_enqv(descP->outQ, iovec, n))
+            return -3;
+    } else {
+        /* Dequeue any data that was written from the queue. */
+        if (n > 0 && !enif_ioq_deq(descP->outQ, n, NULL))
+            return -4;
+    }
+    /* return n, which is either number of bytes written or -1 if
+       some error happened */
+    errno = saved_errno;
+    return n;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_recv
+ *
+ * Description:
+ * Receive a message on a socket.
+ * Normally used only on a connected socket!
+ * If we are trying to read > 0 bytes, then that is what we do.
+ * But if we have specified 0 bytes, then we want to read
+ * whatever is in the buffers (everything it got).
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * RecvRef      - A unique id for this (send) request.
+ * Length       - The number of bytes to receive.
+ * Flags        - Receive flags.
+ */
+
+static
+ERL_NIF_TERM nif_recv(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     sockRef, recvRef;
+    int              len;
+    unsigned int     eflags;
+    int              flags;
+    ERL_NIF_TERM     res;
+
+    if ((argc != 4) ||
+        !GET_INT(env, argv[2], &len) ||
+        !GET_UINT(env, argv[3], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we send abort (to the caller)
+    recvRef = argv[1];
+
+    if (!ESOCK_GET_RESOURCE(env, sockRef, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    
+    if (!erecvflags2recvflags(eflags, &flags))
+        return enif_make_badarg(env);
+
+    MLOCK(descP->readMtx);
+
+    /* We need to handle the case when another process tries
+     * to receive at the same time.
+     * If the current recv could not read its entire package
+     * this time (resulting in an select). The read of the
+     * other process must be made to wait until current
+     * is done!
+     */
+
+    res = esock_recv(env, descP, sockRef, recvRef, len, flags);
+
+    MUNLOCK(descP->readMtx);
+
+    return res;
+
+#endif // if defined(__WIN32__)
+}
+
+
+/* The (read) buffer handling should be optimized!
+ * But for now we make it easy for ourselves by
+ * allocating a binary (of the specified or default
+ * size) and then throwing it away...
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_recv(ErlNifEnv*       env,
+                        ESockDescriptor* descP,
+                        ERL_NIF_TERM     sockRef,
+                        ERL_NIF_TERM     recvRef,
+                        int              len,
+                        int              flags)
+{
+    ssize_t      read;
+    ErlNifBinary buf;
+    ERL_NIF_TERM readerCheck;
+    int          save_errno;
+    int          bufSz = (len ? len : descP->rBufSz);
+
+    SSDBG( descP, ("SOCKET", "esock_recv -> entry with"
+                   "\r\n   len:   %d (%d:%d)"
+                   "\r\n   flags: %d"
+                   "\r\n", len, descP->rNumCnt, bufSz, flags) );
+
+    if (!descP->isReadable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current reader and if its us */
+    if (!recv_check_reader(env, descP, recvRef, &readerCheck))
+        return readerCheck;
+    
+    /* Allocate a buffer:
+     * Either as much as we want to read or (if zero (0)) use the "default"
+     * size (what has been configured).
+     */
+    if (!ALLOC_BIN(bufSz, &buf))
+        return esock_make_error(env, atom_exalloc);
+
+    // cnt_inc(&descP->readTries, 1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_read_tries, &descP->readTries, 1);
+
+    // If it fails (read = -1), we need errno...
+    SSDBG( descP, ("SOCKET", "esock_recv -> try read (%d)\r\n", buf.size) );
+    read = sock_recv(descP->sock, buf.data, buf.size, flags);
+    if (IS_SOCKET_ERROR(read)) {
+        save_errno = sock_errno();
+    } else {
+        save_errno = -1; // The value does not actually matter in this case
+    }
+    
+    SSDBG( descP, ("SOCKET",
+                   "esock_recv -> read: %d (%d)\r\n", read, save_errno) );
+
+    return recv_check_result(env, descP,
+                             read, len,
+                             save_errno,
+                             &buf,
+                             sockRef,
+                             recvRef);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_recvfrom
+ *
+ * Description:
+ * Receive a message on a socket.
+ * Normally used only on a (un-) connected socket!
+ * If a buffer size = 0 is specified, then the we will use the default
+ * buffer size for this socket (whatever has been configured).
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * RecvRef      - A unique id for this (send) request.
+ * BufSz        - Size of the buffer into which we put the received message.
+ * Flags        - Receive flags.
+ *
+ * <KOLLA>
+ *
+ * How do we handle if the peek flag is set? We need to basically keep
+ * track of if we expect any data from the read. Regardless of the 
+ * number of bytes we try to read.
+ *
+ * </KOLLA>
+ */
+
+static
+ERL_NIF_TERM nif_recvfrom(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     sockRef, recvRef;
+    unsigned int     bufSz;
+    unsigned int     eflags;
+    int              flags;
+    ERL_NIF_TERM     res;
+
+    SGDBG( ("SOCKET", "nif_recvfrom -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 4) ||
+        !GET_UINT(env, argv[2], &bufSz) ||
+        !GET_UINT(env, argv[3], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we send abort (to the caller)
+    recvRef = argv[1];
+
+    if (!ESOCK_GET_RESOURCE(env, sockRef, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nif_recvfrom -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   recvRef: %T"
+            "\r\n   bufSz:   %d"
+            "\r\n   eflags:  %d"
+            "\r\n", descP->sock, argv[0], recvRef, bufSz, eflags) );
+
+    /* if (IS_OPEN(descP)) */
+    /*     return esock_make_error(env, atom_enotconn); */
+
+    if (!erecvflags2recvflags(eflags, &flags)) {
+        SSDBG( descP, ("SOCKET", "nif_recvfrom -> recvflags decode failed\r\n") );
+        return enif_make_badarg(env);
+    }
+
+    MLOCK(descP->readMtx);
+
+    /* <KOLLA>
+     * We need to handle the case when another process tries
+     * to receive at the same time.
+     * If the current recv could not read its entire package
+     * this time (resulting in an select). The read of the
+     * other process must be made to wait until current
+     * is done!
+     * Basically, we need a read queue!
+     *
+     * A 'reading' field (boolean), which is set if we did
+     * not manage to read the entire message and reset every
+     * time we do.
+     * </KOLLA>
+     */
+
+    res = esock_recvfrom(env, descP, sockRef, recvRef, bufSz, flags);
+
+    MUNLOCK(descP->readMtx);
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+/* The (read) buffer handling *must* be optimized!
+ * But for now we make it easy for ourselves by
+ * allocating a binary (of the specified or default
+ * size) and then throwing it away...
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_recvfrom(ErlNifEnv*       env,
+                            ESockDescriptor* descP,
+                            ERL_NIF_TERM     sockRef,
+                            ERL_NIF_TERM     recvRef,
+                            Uint16           len,
+                            int              flags)
+{
+    ESockAddress  fromAddr;
+    unsigned int  addrLen;
+    ssize_t       read;
+    int           save_errno;
+    ErlNifBinary  buf;
+    ERL_NIF_TERM  readerCheck;
+    int           bufSz = (len ? len : descP->rBufSz);
+
+    SSDBG( descP, ("SOCKET", "esock_recvfrom -> entry with"
+                   "\r\n   len:   %d (%d)"
+                   "\r\n   flags: %d"
+                   "\r\n", len, bufSz, flags) );
+
+    if (!descP->isReadable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current reader and if its us */
+    if (!recv_check_reader(env, descP, recvRef, &readerCheck))
+        return readerCheck;
+    
+    /* Allocate a buffer:
+     * Either as much as we want to read or (if zero (0)) use the "default"
+     * size (what has been configured).
+     */
+    if (!ALLOC_BIN(bufSz, &buf))
+        return esock_make_error(env, atom_exalloc);
+
+    // cnt_inc(&descP->readTries, 1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_read_tries, &descP->readTries, 1);
+
+    addrLen = sizeof(fromAddr);
+    sys_memzero((char*) &fromAddr, addrLen);
+
+    read = sock_recvfrom(descP->sock, buf.data, buf.size, flags,
+                         &fromAddr.sa, &addrLen);
+    if (IS_SOCKET_ERROR(read))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // The value does not actually matter in this case
+
+    return recvfrom_check_result(env, descP,
+                                 read,
+                                 save_errno,
+                                 &buf,
+                                 &fromAddr, addrLen,
+                                 sockRef,
+                                 recvRef);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_recvmsg
+ *
+ * Description:
+ * Receive a message on a socket.
+ * Normally used only on a (un-) connected socket!
+ * If a buffer size = 0 is specified, then we will use the default
+ * buffer size for this socket (whatever has been configured).
+ * If ctrl (buffer) size = 0 is specified, then the default ctrl
+ * (buffer) size is used (1024). 
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * RecvRef      - A unique id for this (send) request.
+ * BufSz        - Size of the buffer into which we put the received message.
+ * CtrlSz       - Size of the ctrl (buffer) into which we put the received 
+ *                ancillary data.
+ * Flags        - Receive flags.
+ *
+ * <KOLLA>
+ *
+ * How do we handle if the peek flag is set? We need to basically keep
+ * track of if we expect any data from the read. Regardless of the 
+ * number of bytes we try to read.
+ *
+ * </KOLLA>
+ */
+
+static
+ERL_NIF_TERM nif_recvmsg(ErlNifEnv*         env,
+                         int                argc,
+                         const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     sockRef, recvRef;
+    unsigned int     bufSz;
+    unsigned int     ctrlSz;
+    unsigned int     eflags;
+    int              flags;
+    ERL_NIF_TERM     res;
+
+    SGDBG( ("SOCKET", "nif_recvmsg -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 5) ||
+        !GET_UINT(env, argv[2], &bufSz) ||
+        !GET_UINT(env, argv[3], &ctrlSz) ||
+        !GET_UINT(env, argv[4], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we send abort (to the caller)
+    recvRef = argv[1];
+
+    if (!ESOCK_GET_RESOURCE(env, sockRef, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_recvmsg -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   recvRef: %T"
+            "\r\n   bufSz:   %d"
+            "\r\n   ctrlSz:  %d"
+            "\r\n   eflags:  %d"
+            "\r\n", descP->sock, argv[0], recvRef, bufSz, ctrlSz, eflags) );
+
+    /* if (IS_OPEN(descP)) */
+    /*     return esock_make_error(env, atom_enotconn); */
+
+    if (!erecvflags2recvflags(eflags, &flags))
+        return enif_make_badarg(env);
+
+    MLOCK(descP->readMtx);
+
+    /* <KOLLA>
+     *
+     * We need to handle the case when another process tries
+     * to receive at the same time.
+     * If the current recv could not read its entire package
+     * this time (resulting in an select). The read of the
+     * other process must be made to wait until current
+     * is done!
+     * Basically, we need a read queue!
+     *
+     * A 'reading' field (boolean), which is set if we did
+     * not manage to read the entire message and reset every
+     * time we do.
+     *
+     * </KOLLA>
+     */
+
+    res = esock_recvmsg(env, descP, sockRef, recvRef, bufSz, ctrlSz, flags);
+
+    MUNLOCK(descP->readMtx);
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+/* The (read) buffer handling *must* be optimized!
+ * But for now we make it easy for ourselves by
+ * allocating a binary (of the specified or default
+ * size) and then throwing it away...
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_recvmsg(ErlNifEnv*       env,
+                           ESockDescriptor* descP,
+                           ERL_NIF_TERM     sockRef,
+                           ERL_NIF_TERM     recvRef,
+                           Uint16           bufLen,
+                           Uint16           ctrlLen,
+                           int              flags)
+{
+    unsigned int  addrLen;
+    ssize_t       read;
+    int           save_errno;
+    int           bufSz  = (bufLen  ? bufLen  : descP->rBufSz);
+    int           ctrlSz = (ctrlLen ? ctrlLen : descP->rCtrlSz);
+    struct msghdr msgHdr;
+    struct iovec  iov[1];  // Shall we always use 1?
+    ErlNifBinary  data[1]; // Shall we always use 1?
+    ErlNifBinary  ctrl;
+    ERL_NIF_TERM  readerCheck;
+    ESockAddress  addr;
+
+    SSDBG( descP, ("SOCKET", "esock_recvmsg -> entry with"
+                   "\r\n   bufSz:  %d (%d)"
+                   "\r\n   ctrlSz: %d (%d)"
+                   "\r\n   flags:  %d"
+                   "\r\n", bufSz, bufLen, ctrlSz, ctrlLen, flags) );
+
+    if (!descP->isReadable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current reader and if its us */
+    if (!recv_check_reader(env, descP, recvRef, &readerCheck))
+        return readerCheck;
+    
+    /*
+    for (i = 0; i < sizeof(buf); i++) {
+        if (!ALLOC_BIN(bifSz, &buf[i]))
+            return esock_make_error(env, atom_exalloc);
+        iov[i].iov_base = buf[i].data;
+        iov[i].iov_len  = buf[i].size;
+    }
+    */
+    
+    /* Allocate the (msg) data buffer:
+     */
+    if (!ALLOC_BIN(bufSz, &data[0]))
+        return esock_make_error(env, atom_exalloc);
+
+    /* Allocate the ctrl (buffer):
+     */
+    if (!ALLOC_BIN(ctrlSz, &ctrl))
+        return esock_make_error(env, atom_exalloc);
+
+    // cnt_inc(&descP->readTries, 1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_read_tries, &descP->readTries, 1);
+
+    addrLen = sizeof(addr);
+    sys_memzero((char*) &addr,   addrLen);
+    sys_memzero((char*) &msgHdr, sizeof(msgHdr));
+
+    iov[0].iov_base = data[0].data;
+    iov[0].iov_len  = data[0].size;
+        
+    msgHdr.msg_name       = &addr;
+    msgHdr.msg_namelen    = addrLen;
+    msgHdr.msg_iov        = iov;
+    msgHdr.msg_iovlen     = 1; // Should use a constant or calculate...
+    msgHdr.msg_control    = ctrl.data;
+    msgHdr.msg_controllen = ctrl.size;
+
+    read = sock_recvmsg(descP->sock, &msgHdr, flags);
+    if (IS_SOCKET_ERROR(read))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // The value does not actually matter in this case
+
+    return recvmsg_check_result(env, descP,
+                                read,
+                                save_errno,
+                                &msgHdr,
+                                data,  // Needed for iov encode
+                                &ctrl, // Needed for ctrl header encode
+                                sockRef,
+                                recvRef);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_close
+ *
+ * Description:
+ * Close a (socket) file descriptor.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+
+static
+ERL_NIF_TERM nif_close(ErlNifEnv*         env,
+                       int                argc,
+                       const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+
+    if ((argc != 1) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    return esock_close(env, descP);
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_close(ErlNifEnv*       env,
+                         ESockDescriptor* descP)
+{
+    ERL_NIF_TERM reply, reason;
+    BOOLEAN_T    doClose;
+
+    SSDBG( descP, ("SOCKET", 
+                   "esock_close -> [%d] entry (0x%lX, 0x%lX, 0x%lX, 0x%lX)\r\n",
+                   descP->sock,
+                   descP->state,
+                   descP->currentWriterP,
+                   descP->currentReaderP,
+                   descP->currentAcceptorP) );
+
+    MLOCK(descP->closeMtx);
+
+    doClose = esock_close_check(env, descP, &reason);
+
+    if (doClose) {
+        reply = esock_close_do(env, descP);
+    } else {
+        reply = esock_make_error(env, reason);
+    }
+
+    MUNLOCK(descP->closeMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_close -> [%d] done when: "
+            "\r\n   state: 0x%lX"
+            "\r\n   reply: %T"
+            "\r\n", descP->sock, descP->state, reply) );
+
+    return reply;
+}
+
+
+
+/* *** esock_close_check ***
+ *
+ * Check if we should try to perform the first stage close.
+ */
+static
+BOOLEAN_T esock_close_check(ErlNifEnv*       env,
+                            ESockDescriptor* descP,
+                            ERL_NIF_TERM*    reason)
+{
+    BOOLEAN_T doClose;
+
+    if (descP->state == ESOCK_STATE_CLOSED) {
+
+        doClose = FALSE;
+        *reason = atom_closed;
+
+    } else if (descP->state == ESOCK_STATE_CLOSING) {
+
+        doClose = FALSE;
+        *reason = atom_closing;
+
+    } else {
+
+        /* Store the PID of the caller,
+         * since we need to inform it when we
+         * (that is, the stop callback function)
+         * completes.
+         */
+
+        if (enif_self(env, &descP->closerPid) == NULL) {
+
+            doClose = FALSE;
+            *reason = atom_exself;
+
+        } else {
+
+            /* Monitor the caller, since we should complete this
+             * operation even if the caller dies (for whatever reason).
+             *
+             * <KOLLA>
+             *
+             * Can we actually use this for anything?
+             *
+             * </KOLLA>
+             */
+
+            if (MONP("esock_close_check -> closer",
+                     env, descP,
+                     &descP->closerPid,
+                     &descP->closerMon) != 0) {
+
+                doClose = FALSE;
+                *reason = atom_exmon;
+
+            } else {
+
+                descP->closeLocal = TRUE;
+                descP->state      = ESOCK_STATE_CLOSING;
+                descP->isReadable = FALSE;
+                descP->isWritable = FALSE;
+                doClose           = TRUE;
+                *reason           = esock_atom_undefined; // NOT used !!
+
+            }
+        }
+    }
+
+    return doClose;
+    
+}
+
+
+
+/* *** esock_close_do ***
+ *
+ * Perform (do) the first stage close.
+ */
+static
+ERL_NIF_TERM esock_close_do(ErlNifEnv*       env,
+                            ESockDescriptor* descP)
+{
+    int          domain   = descP->domain;
+    int          type     = descP->type;
+    int          protocol = descP->protocol;
+    int          sres;
+    ERL_NIF_TERM reply, reason;
+
+    descP->closeEnv = esock_alloc_env("esock_close_do - close-env");
+    descP->closeRef = MKREF(descP->closeEnv);
+
+    sres            = esock_select_stop(env, descP->sock, descP);
+
+    if (sres & ERL_NIF_SELECT_STOP_CALLED) {
+
+        /* Prep done - inform the caller it can finalize (close) directly */
+        SSDBG( descP,
+               ("SOCKET",
+                "esock_close -> [%d] stop was called\r\n", descP->sock) );
+
+        dec_socket(domain, type, protocol);
+        reply = esock_atom_ok;
+
+    } else if (sres & ERL_NIF_SELECT_STOP_SCHEDULED) {
+
+        /* The stop callback function has been *scheduled* which means that we
+         * have to wait for it to complete. */
+        SSDBG( descP,
+               ("SOCKET", "esock_close -> [%d] stop was scheduled\r\n",
+                descP->sock) );
+
+        dec_socket(domain, type, protocol); // SHALL WE DO THIS AT finalize?
+        reply = esock_make_ok2(env, enif_make_copy(env, descP->closeRef));
+
+    } else {
+
+        SSDBG( descP,
+               ("SOCKET", "esock_close -> [%d] stop failed: %d\r\n",
+                descP->sock, sres) );
+
+        /* <KOLLA>
+         *
+         * WE SHOULD REALLY HAVE A WAY TO CLOBBER THE SOCKET,
+         * SO WE DON'T LET STUFF LEAK.
+         * NOW, BECAUSE WE FAILED TO SELECT, WE CANNOT FINISH
+         * THE CLOSE, WHAT TO DO? ABORT?
+         *
+         * </KOLLA>
+         */
+
+        // Do we need this?
+        DEMONP("esock_close_do -> closer", env, descP, &descP->closerMon); 
+
+        reason = MKT2(env, esock_atom_select_failed, MKI(env, sres));
+        reply  = esock_make_error(env, reason);
+    }
+
+    return reply;
+}
+
+
+
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_finalize_close
+ *
+ * Description:
+ * Perform the actual socket close!
+ * Note that this function is executed in a dirty scheduler.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+static
+ERL_NIF_TERM nif_finalize_close(ErlNifEnv*         env,
+                                int                argc,
+                                const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    return esock_finalize_close(env, descP);
+#endif // if defined(__WIN32__)
+}
+
+
+/* *** esock_finalize_close ***
+ * Perform the final step in the socket close.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_finalize_close(ErlNifEnv*       env,
+                                  ESockDescriptor* descP)
+{
+    ERL_NIF_TERM reply;
+
+    if (IS_CLOSED(descP))
+        return esock_atom_ok;
+
+    if (!IS_CLOSING(descP))
+        return esock_make_error(env, atom_enotclosing);
+
+    /* This nif is executed in a dirty scheduler just so that
+     * it can "hang" (whith minumum effect on the VM) while the
+     * kernel writes our buffers. IF we have set the linger option
+     * for this ({true, integer() > 0}). For this to work we must
+     * be blocking...
+     */
+    SET_BLOCKING(descP->sock);
+
+    if (sock_close(descP->sock) != 0) {
+        int save_errno = sock_errno();
+
+        if (save_errno != ERRNO_BLOCK) {
+            /* Not all data in the buffers where sent,
+             * make sure the caller gets this.
+             */
+            reply = esock_make_error(env, atom_timeout);
+        } else {
+            reply = esock_make_error_errno(env, save_errno);
+        }
+    } else {
+        reply = esock_atom_ok;
+    }
+    sock_close_event(descP->event);
+
+    descP->sock  = INVALID_SOCKET;
+    descP->event = INVALID_EVENT;
+
+    descP->state = ESOCK_STATE_CLOSED;
+
+    return reply;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_shutdown
+ *
+ * Description:
+ * Disable sends and/or receives on a socket.
+ *
+ * Arguments:
+ * [0] Socket (ref) - Points to the socket descriptor.
+ * [1] How          - What will be shutdown.
+ */
+
+static
+ERL_NIF_TERM nif_shutdown(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    unsigned int     ehow;
+    int              how;
+
+    if ((argc != 2) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP) ||
+        !GET_UINT(env, argv[1], &ehow)) {
+        return enif_make_badarg(env);
+    }
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    if (!ehow2how(ehow, &how))
+        return enif_make_badarg(env);
+
+    return esock_shutdown(env, descP, how);
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_shutdown(ErlNifEnv*       env,
+                            ESockDescriptor* descP,
+                            int              how)
+{
+    ERL_NIF_TERM reply;
+
+    if (sock_shutdown(descP->sock, how) == 0) {
+        switch (how) {
+        case SHUT_RD:
+            descP->isReadable = FALSE;
+            break;
+        case SHUT_WR:
+            descP->isWritable = FALSE;
+            break;
+        case SHUT_RDWR:
+            descP->isReadable = FALSE;
+            descP->isWritable = FALSE;
+            break;
+        }
+        reply = esock_atom_ok;
+    } else {
+        reply = esock_make_error_errno(env, sock_errno());
+    }
+
+    return reply;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_setopt
+ *
+ * Description:
+ * Set socket option.
+ * Its possible to use a "raw" mode (not encoded). That is, we do not
+ * interpret level, opt and value. They are passed "as is" to the
+ * setsockopt function call (the value arguments is assumed to be a
+ * binary, already encoded).
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * Encoded      - Are the "arguments" encoded or not.
+ * Level        - Level of the socket option.
+ * Opt          - The socket option.
+ * Value        - Value of the socket option (type depend on the option).
+ */
+
+static
+ERL_NIF_TERM nif_setopt(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__) 
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP = NULL;
+    int              eLevel, level = -1;
+    int              eOpt;
+    ERL_NIF_TERM     eIsEncoded;
+    ERL_NIF_TERM     eVal;
+    BOOLEAN_T        isEncoded, isOTP;
+    ERL_NIF_TERM     result;
+
+    SGDBG( ("SOCKET", "nif_setopt -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 5) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP) ||
+        !GET_INT(env, argv[2], &eLevel) ||
+        !GET_INT(env, argv[3], &eOpt)) {
+        SGDBG( ("SOCKET", "nif_setopt -> failed initial arg check\r\n") );
+        return enif_make_badarg(env);
+    }
+    eIsEncoded = argv[1];
+    eVal       = argv[4];
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    isEncoded = esock_decode_bool(eIsEncoded);
+
+    /* SGDBG( ("SOCKET", "nif_setopt -> eIsDecoded (%T) decoded: %d\r\n", */
+    /*         eIsEncoded, isEncoded) ); */
+
+    if (!elevel2level(isEncoded, eLevel, &isOTP, &level)) {
+        SSDBG( descP, ("SOCKET", "nif_seopt -> failed decode level\r\n") );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nif_setopt -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   Encoded: %d (%T)"
+            "\r\n   Level:   %d (%d)"
+            "\r\n   Opt:     %d"
+            "\r\n   Value:   %T"
+            "\r\n",
+            descP->sock, argv[0],
+            isEncoded, eIsEncoded,
+            level, eLevel,
+            eOpt, eVal) );
+
+    MLOCK(descP->cfgMtx);
+
+    result = esock_setopt(env, descP, isEncoded, isOTP, level, eOpt, eVal);
+
+    MUNLOCK(descP->cfgMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "nif_setopt -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_setopt(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          BOOLEAN_T        isEncoded,
+                          BOOLEAN_T        isOTP,
+                          int              level,
+                          int              eOpt,
+                          ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    if (isOTP) {
+        /* These are not actual socket options,
+         * but options for our implementation.
+         */
+        result = esock_setopt_otp(env, descP, eOpt, eVal);
+    } else if (!isEncoded) {
+        result = esock_setopt_native(env, descP, level, eOpt, eVal);
+    } else {
+        result = esock_setopt_level(env, descP, level, eOpt, eVal);
+    }
+
+    return result;
+}
+
+
+
+/* esock_setopt_otp - Handle OTP (level) options
+ */
+static
+ERL_NIF_TERM esock_setopt_otp(ErlNifEnv*       env,
+                              ESockDescriptor* descP,
+                              int              eOpt,
+                              ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_otp -> entry with"
+            "\r\n   eOpt: %d"
+            "\r\n   eVal: %T"
+            "\r\n", eOpt, eVal) );
+
+    switch (eOpt) {
+    case ESOCK_OPT_OTP_DEBUG:
+        result = esock_setopt_otp_debug(env, descP, eVal);
+        break;
+
+    case ESOCK_OPT_OTP_IOW:
+        result = esock_setopt_otp_iow(env, descP, eVal);
+        break;
+
+    case ESOCK_OPT_OTP_CTRL_PROC:
+        result = esock_setopt_otp_ctrl_proc(env, descP, eVal);
+        break;
+
+    case ESOCK_OPT_OTP_RCVBUF:
+        result = esock_setopt_otp_rcvbuf(env, descP, eVal);
+        break;
+
+    case ESOCK_OPT_OTP_RCVCTRLBUF:
+        result = esock_setopt_otp_rcvctrlbuf(env, descP, eVal);
+        break;
+
+    case ESOCK_OPT_OTP_SNDCTRLBUF:
+        result = esock_setopt_otp_sndctrlbuf(env, descP, eVal);
+        break;
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* esock_setopt_otp_debug - Handle the OTP (level) debug options
+ */
+static
+ERL_NIF_TERM esock_setopt_otp_debug(ErlNifEnv*       env,
+                                    ESockDescriptor* descP,
+                                    ERL_NIF_TERM     eVal)
+{
+    descP->dbg = esock_decode_bool(eVal);
+
+    return esock_atom_ok;
+}
+
+
+/* esock_setopt_otp_iow - Handle the OTP (level) iow options
+ */
+static
+ERL_NIF_TERM esock_setopt_otp_iow(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  ERL_NIF_TERM     eVal)
+{
+    descP->iow = esock_decode_bool(eVal);
+
+    return esock_atom_ok;
+}
+
+
+
+/* esock_setopt_otp_ctrl_proc - Handle the OTP (level) 
+ * controlling_process options
+ */
+static
+ERL_NIF_TERM esock_setopt_otp_ctrl_proc(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        ERL_NIF_TERM     eVal)
+{
+    ErlNifPid     caller, newCtrlPid;
+    ESockMonitor  newCtrlMon;
+    int           xres;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_otp_ctrl_proc -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    /* Before we begin, ensure that caller is (current) controlling-process */
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    if (COMPARE_PIDS(&descP->ctrlPid, &caller) != 0) {
+        SSDBG( descP, ("SOCKET",
+                       "esock_setopt_otp_ctrl_proc -> not owner (%T)\r\n",
+                       descP->ctrlPid) );
+        return esock_make_error(env, esock_atom_not_owner);
+    }
+    
+    if (!GET_LPID(env, eVal, &newCtrlPid)) {
+        esock_warning_msg("Failed get pid of new controlling process\r\n");
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if ((xres = MONP("esock_setopt_otp_ctrl_proc -> (new) ctrl",
+                     env, descP, &newCtrlPid, &newCtrlMon)) != 0) {
+        esock_warning_msg("Failed monitor (%d) (new) controlling process\r\n",
+                          xres);
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if ((xres = DEMONP("esock_setopt_otp_ctrl_proc -> (old) ctrl",
+                       env, descP, &descP->ctrlMon)) != 0) {
+        esock_warning_msg("Failed demonitor (%d) "
+                          "old controlling process %T (%T)\r\n",
+                          xres, descP->ctrlPid, descP->ctrlMon);
+    }
+
+    descP->ctrlPid = newCtrlPid;
+    descP->ctrlMon = newCtrlMon;
+    
+    SSDBG( descP, ("SOCKET", "esock_setopt_otp_ctrl_proc -> done\r\n") );
+
+    return esock_atom_ok;
+}
+
+
+
+/* esock_setopt_otp_rcvbuf - Handle the OTP (level) rcvbuf option
+ * The (otp) rcvbuf option is provided as:
+ *
+ *       BufSz :: integer() | {N :: pos_integer(), BufSz :: pod_integer()}
+ *
+ * Where N is the max number of reads.
+ */
+static
+ERL_NIF_TERM esock_setopt_otp_rcvbuf(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     ERL_NIF_TERM     eVal)
+{
+    const ERL_NIF_TERM* t;   // The array of the elements of the tuple
+    int                 tsz; // The size of the tuple - should be 2
+    unsigned int        n;
+    size_t              bufSz;
+    char*               xres;
+
+    if (IS_NUM(env, eVal)) {
+
+        /* This will have the effect that the buffer size will be
+         * reported as an integer (getopt).
+         */
+        n = 0;
+
+        if ((xres = esock_decode_bufsz(env,
+                                       eVal,
+                                       ESOCK_RECV_BUFFER_SIZE_DEFAULT,
+                                       &bufSz)) != NULL)
+            return esock_make_error_str(env, xres);
+
+    } else if (IS_TUPLE(env, eVal)) {
+
+        if (!GET_TUPLE(env, eVal, &tsz, &t))
+            return enif_make_badarg(env); // We should use a "proper" error value...
+
+        if (tsz != 2)
+            return enif_make_badarg(env); // We should use a "proper" error value...
+    
+        if (!GET_UINT(env, t[0], &n))
+            return enif_make_badarg(env); // We should use a "proper" error value...
+
+        if ((xres = esock_decode_bufsz(env,
+                                       t[1],
+                                       ESOCK_RECV_BUFFER_SIZE_DEFAULT,
+                                       &bufSz)) != NULL)
+            return esock_make_error_str(env, xres);
+
+    } else {
+        return enif_make_badarg(env); // We should use a "proper" error value...
+    }
+
+    descP->rNum   = n;
+    descP->rBufSz = bufSz;
+
+    return esock_atom_ok;
+}
+
+
+
+/* esock_setopt_otp_rcvctrlbuf - Handle the OTP (level) rcvctrlbuf option
+ */
+static
+ERL_NIF_TERM esock_setopt_otp_rcvctrlbuf(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+    size_t val;
+    char*  xres;
+
+    if ((xres = esock_decode_bufsz(env,
+                                   eVal,
+                                   ESOCK_RECV_CTRL_BUFFER_SIZE_DEFAULT,
+                                   &val)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    descP->rCtrlSz = val;
+    
+    return esock_atom_ok;
+}
+
+
+
+/* esock_setopt_otp_sndctrlbuf - Handle the OTP (level) sndctrlbuf option
+ */
+static
+ERL_NIF_TERM esock_setopt_otp_sndctrlbuf(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+    size_t val;
+    char*  xres;
+
+    if ((xres = esock_decode_bufsz(env,
+                                   eVal,
+                                   ESOCK_SEND_CTRL_BUFFER_SIZE_DEFAULT,
+                                   &val)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    descP->wCtrlSz = val;
+    
+    return esock_atom_ok;
+}
+
+
+
+/* The option has *not* been encoded. Instead it has been provided
+ * in "native mode" (option is provided as is and value as a binary).
+ */
+static
+ERL_NIF_TERM esock_setopt_native(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 int              level,
+                                 int              opt,
+                                 ERL_NIF_TERM     eVal)
+{
+    ErlNifBinary val;
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_native -> entry with"
+            "\r\n   level: %d"
+            "\r\n   opt:   %d"
+            "\r\n   eVal:  %T"
+            "\r\n", level, opt, eVal) );
+
+    if (GET_BIN(env, eVal, &val)) {
+        int res = socket_setopt(descP->sock, level, opt,
+                                val.data, val.size);
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_native -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* esock_setopt_level - A "proper" level (option) has been specified
+ */
+static
+ERL_NIF_TERM esock_setopt_level(ErlNifEnv*       env,
+                                ESockDescriptor* descP,
+                                int              level,
+                                int              eOpt,
+                                ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_level -> entry with"
+            "\r\n   level: %d"
+            "\r\n", level) );
+
+    switch (level) {
+    case SOL_SOCKET:
+        result = esock_setopt_lvl_socket(env, descP, eOpt, eVal);
+        break;
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        result = esock_setopt_lvl_ip(env, descP, eOpt, eVal);
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif
+        result = esock_setopt_lvl_ipv6(env, descP, eOpt, eVal);
+        break;
+#endif
+
+    case IPPROTO_TCP:
+        result = esock_setopt_lvl_tcp(env, descP, eOpt, eVal);
+        break;
+
+    case IPPROTO_UDP:
+        result = esock_setopt_lvl_udp(env, descP, eOpt, eVal);
+        break;
+
+#if defined(HAVE_SCTP)
+    case IPPROTO_SCTP:
+        result = esock_setopt_lvl_sctp(env, descP, eOpt, eVal);
+        break;
+#endif
+
+    default:
+        SSDBG( descP,
+               ("SOCKET",
+                "esock_setopt_level -> unknown level (%d)\r\n", level) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_level -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* esock_setopt_lvl_socket - Level *SOCKET* option
+ */
+static
+ERL_NIF_TERM esock_setopt_lvl_socket(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     int              eOpt,
+                                     ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_socket -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(SO_BINDTODEVICE)
+    case ESOCK_OPT_SOCK_BINDTODEVICE:
+        result = esock_setopt_lvl_sock_bindtodevice(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_BROADCAST)
+    case ESOCK_OPT_SOCK_BROADCAST:
+        result = esock_setopt_lvl_sock_broadcast(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_DEBUG)
+    case ESOCK_OPT_SOCK_DEBUG:
+        result = esock_setopt_lvl_sock_debug(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_DONTROUTE)
+    case ESOCK_OPT_SOCK_DONTROUTE:
+        result = esock_setopt_lvl_sock_dontroute(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_KEEPALIVE)
+    case ESOCK_OPT_SOCK_KEEPALIVE:
+        result = esock_setopt_lvl_sock_keepalive(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_LINGER)
+    case ESOCK_OPT_SOCK_LINGER:
+        result = esock_setopt_lvl_sock_linger(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_PEEK_OFF)
+    case ESOCK_OPT_SOCK_PEEK_OFF:
+        result = esock_setopt_lvl_sock_peek_off(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_OOBINLINE)
+    case ESOCK_OPT_SOCK_OOBINLINE:
+        result = esock_setopt_lvl_sock_oobinline(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_PRIORITY)
+    case ESOCK_OPT_SOCK_PRIORITY:
+        result = esock_setopt_lvl_sock_priority(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_RCVBUF)
+    case ESOCK_OPT_SOCK_RCVBUF:
+        result = esock_setopt_lvl_sock_rcvbuf(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_RCVLOWAT)
+    case ESOCK_OPT_SOCK_RCVLOWAT:
+        result = esock_setopt_lvl_sock_rcvlowat(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_RCVTIMEO)
+    case ESOCK_OPT_SOCK_RCVTIMEO:
+        result = esock_setopt_lvl_sock_rcvtimeo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_REUSEADDR)
+    case ESOCK_OPT_SOCK_REUSEADDR:
+        result = esock_setopt_lvl_sock_reuseaddr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_REUSEPORT)
+    case ESOCK_OPT_SOCK_REUSEPORT:
+        result = esock_setopt_lvl_sock_reuseport(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_SNDBUF)
+    case ESOCK_OPT_SOCK_SNDBUF:
+        result = esock_setopt_lvl_sock_sndbuf(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_SNDLOWAT)
+    case ESOCK_OPT_SOCK_SNDLOWAT:
+        result = esock_setopt_lvl_sock_sndlowat(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_SNDTIMEO)
+    case ESOCK_OPT_SOCK_SNDTIMEO:
+        result = esock_setopt_lvl_sock_sndtimeo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_TIMESTAMP)
+    case ESOCK_OPT_SOCK_TIMESTAMP:
+        result = esock_setopt_lvl_sock_timestamp(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        SSDBG( descP,
+               ("SOCKET",
+                "esock_setopt_lvl_socket -> unknown opt (%d)\r\n", eOpt) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_socket -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+#if defined(SO_BINDTODEVICE)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_bindtodevice(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_str_opt(env, descP,
+                                SOL_SOCKET, SO_BINDTODEVICE,
+                                IFNAMSIZ, eVal);
+}
+#endif
+
+
+#if defined(SO_BROADCAST)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_broadcast(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, SOL_SOCKET, SO_BROADCAST, eVal);
+}
+#endif
+
+
+#if defined(SO_DEBUG)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_debug(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP, SOL_SOCKET, SO_DEBUG, eVal);
+}
+#endif
+
+
+#if defined(SO_DONTROUTE)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_dontroute(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, SOL_SOCKET, SO_DONTROUTE, eVal);
+}
+#endif
+
+
+#if defined(SO_KEEPALIVE)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_keepalive(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, SOL_SOCKET, SO_KEEPALIVE, eVal);
+}
+#endif
+
+
+#if defined(SO_LINGER)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_linger(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM  result;
+    struct linger val;
+
+    if (decode_sock_linger(env, eVal, &val)) {
+        int optLen = sizeof(val);
+        int res    = socket_setopt(descP->sock, SOL_SOCKET, SO_LINGER,
+                                   (void*) &val, optLen);
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(SO_OOBINLINE)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_oobinline(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, SOL_SOCKET, SO_OOBINLINE, eVal);
+}
+#endif
+
+
+#if defined(SO_PEEK_OFF)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_peek_off(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP, SOL_SOCKET, SO_PEEK_OFF, eVal);
+}
+#endif
+
+
+#if defined(SO_PRIORITY)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_priority(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP, SOL_SOCKET, SO_PRIORITY, eVal);
+}
+#endif
+
+
+#if defined(SO_RCVBUF)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_rcvbuf(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP, SOL_SOCKET, SO_RCVBUF, eVal);
+}
+#endif
+
+
+#if defined(SO_RCVLOWAT)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_rcvlowat(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP, SOL_SOCKET, SO_RCVLOWAT, eVal);
+}
+#endif
+
+
+#if defined(SO_RCVTIMEO)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_rcvtimeo(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_timeval_opt(env, descP, SOL_SOCKET, SO_RCVTIMEO, eVal);
+}
+#endif
+
+
+#if defined(SO_REUSEADDR)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_reuseaddr(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, SOL_SOCKET, SO_REUSEADDR, eVal);
+}
+#endif
+
+
+#if defined(SO_REUSEPORT)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_reuseport(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, SOL_SOCKET, SO_REUSEPORT, eVal);
+}
+#endif
+
+
+#if defined(SO_SNDBUF)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_sndbuf(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP, SOL_SOCKET, SO_SNDBUF, eVal);
+}
+#endif
+
+
+#if defined(SO_SNDLOWAT)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_sndlowat(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP, SOL_SOCKET, SO_SNDLOWAT, eVal);
+}
+#endif
+
+
+#if defined(SO_SNDTIMEO)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_sndtimeo(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal)
+{
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sock_sndtimeo -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    return esock_setopt_timeval_opt(env, descP, SOL_SOCKET, SO_SNDTIMEO, eVal);
+}
+#endif
+
+
+#if defined(SO_TIMESTAMP)
+static
+ERL_NIF_TERM esock_setopt_lvl_sock_timestamp(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, SOL_SOCKET, SO_TIMESTAMP, eVal);
+}
+#endif
+
+
+
+/* esock_setopt_lvl_ip - Level *IP* option(s)
+ */
+static
+ERL_NIF_TERM esock_setopt_lvl_ip(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 int              eOpt,
+                                 ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_ip -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(IP_ADD_MEMBERSHIP)
+    case ESOCK_OPT_IP_ADD_MEMBERSHIP:
+        result = esock_setopt_lvl_ip_add_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_ADD_SOURCE_MEMBERSHIP)
+    case ESOCK_OPT_IP_ADD_SOURCE_MEMBERSHIP:
+        result = esock_setopt_lvl_ip_add_source_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_BLOCK_SOURCE)
+    case ESOCK_OPT_IP_BLOCK_SOURCE:
+        result = esock_setopt_lvl_ip_block_source(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_DROP_MEMBERSHIP)
+    case ESOCK_OPT_IP_DROP_MEMBERSHIP:
+        result = esock_setopt_lvl_ip_drop_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_DROP_SOURCE_MEMBERSHIP)
+    case ESOCK_OPT_IP_DROP_SOURCE_MEMBERSHIP:
+        result = esock_setopt_lvl_ip_drop_source_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_FREEBIND)
+    case ESOCK_OPT_IP_FREEBIND:
+        result = esock_setopt_lvl_ip_freebind(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_HDRINCL)
+    case ESOCK_OPT_IP_HDRINCL:
+        result = esock_setopt_lvl_ip_hdrincl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MINTTL)
+    case ESOCK_OPT_IP_MINTTL:
+        result = esock_setopt_lvl_ip_minttl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MSFILTER) && defined(IP_MSFILTER_SIZE)
+    case ESOCK_OPT_IP_MSFILTER:
+        result = esock_setopt_lvl_ip_msfilter(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MTU_DISCOVER)
+    case ESOCK_OPT_IP_MTU_DISCOVER:
+        result = esock_setopt_lvl_ip_mtu_discover(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_ALL)
+    case ESOCK_OPT_IP_MULTICAST_ALL:
+        result = esock_setopt_lvl_ip_multicast_all(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_IF)
+    case ESOCK_OPT_IP_MULTICAST_IF:
+        result = esock_setopt_lvl_ip_multicast_if(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_LOOP)
+    case ESOCK_OPT_IP_MULTICAST_LOOP:
+        result = esock_setopt_lvl_ip_multicast_loop(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_TTL)
+    case ESOCK_OPT_IP_MULTICAST_TTL:
+        result = esock_setopt_lvl_ip_multicast_ttl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_NODEFRAG)
+    case ESOCK_OPT_IP_NODEFRAG:
+        result = esock_setopt_lvl_ip_nodefrag(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_PKTINFO)
+    case ESOCK_OPT_IP_PKTINFO:
+        result = esock_setopt_lvl_ip_pktinfo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVDSTADDR)
+    case ESOCK_OPT_IP_RECVDSTADDR:
+        result = esock_setopt_lvl_ip_recvdstaddr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVERR)
+    case ESOCK_OPT_IP_RECVERR:
+        result = esock_setopt_lvl_ip_recverr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVIF)
+    case ESOCK_OPT_IP_RECVIF:
+        result = esock_setopt_lvl_ip_recvif(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVOPTS)
+    case ESOCK_OPT_IP_RECVOPTS:
+        result = esock_setopt_lvl_ip_recvopts(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVORIGDSTADDR)
+    case ESOCK_OPT_IP_RECVORIGDSTADDR:
+        result = esock_setopt_lvl_ip_recvorigdstaddr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVTOS)
+    case ESOCK_OPT_IP_RECVTOS:
+        result = esock_setopt_lvl_ip_recvtos(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVTTL)
+    case ESOCK_OPT_IP_RECVTTL:
+        result = esock_setopt_lvl_ip_recvttl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RETOPTS)
+    case ESOCK_OPT_IP_RETOPTS:
+        result = esock_setopt_lvl_ip_retopts(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_ROUTER_ALERT)
+    case ESOCK_OPT_IP_ROUTER_ALERT:
+        result = esock_setopt_lvl_ip_router_alert(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_SENDSRCADDR)
+    case ESOCK_OPT_IP_SENDSRCADDR:
+        result = esock_setopt_lvl_ip_sendsrcaddr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_TOS)
+    case ESOCK_OPT_IP_TOS:
+        result = esock_setopt_lvl_ip_tos(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_TRANSPARENT)
+    case ESOCK_OPT_IP_TRANSPARENT:
+        result = esock_setopt_lvl_ip_transparent(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_TTL)
+    case ESOCK_OPT_IP_TTL:
+        result = esock_setopt_lvl_ip_ttl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_UNBLOCK_SOURCE)
+    case ESOCK_OPT_IP_UNBLOCK_SOURCE:
+        result = esock_setopt_lvl_ip_unblock_source(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        SSDBG( descP, ("SOCKET",
+                       "esock_setopt_lvl_ip -> unknown opt (%d)\r\n", eOpt) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_ip -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* esock_setopt_lvl_ip_add_membership - Level IP ADD_MEMBERSHIP option
+ *
+ * The value is a map with two attributes: multiaddr and interface.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is either the atom 'any' or a 4-tuple
+ * (IPv4 address).
+ */
+#if defined(IP_ADD_MEMBERSHIP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_add_membership(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_lvl_ip_update_membership(env, descP, eVal,
+                                                 IP_ADD_MEMBERSHIP);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_add_source_membership -
+ * Level IP ADD_SOURCE_MEMBERSHIP option
+ *
+ * The value is a map with three attributes: multiaddr, interface and
+ * sourceaddr.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is always a 4-tuple (IPv4 address).
+ * The attribute 'sourceaddr' is always a 4-tuple (IPv4 address).
+ * (IPv4 address).
+ */
+#if defined(IP_ADD_SOURCE_MEMBERSHIP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_add_source_membership(ErlNifEnv*       env,
+                                                       ESockDescriptor* descP,
+                                                       ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_lvl_ip_update_source(env, descP, eVal,
+                                             IP_ADD_SOURCE_MEMBERSHIP);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_block_source - Level IP BLOCK_SOURCE option
+ *
+ * The value is a map with three attributes: multiaddr, interface and
+ * sourceaddr.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is always a 4-tuple (IPv4 address).
+ * The attribute 'sourceaddr' is always a 4-tuple (IPv4 address).
+ * (IPv4 address).
+ */
+#if defined(IP_BLOCK_SOURCE)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_block_source(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_lvl_ip_update_source(env, descP, eVal, IP_BLOCK_SOURCE);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_drop_membership - Level IP DROP_MEMBERSHIP option
+ *
+ * The value is a map with two attributes: multiaddr and interface.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is either the atom 'any' or a 4-tuple
+ * (IPv4 address).
+ *
+ * We should really have a common function with add_membership,
+ * since the code is virtually identical (except for the option
+ * value).
+ */
+#if defined(IP_DROP_MEMBERSHIP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_drop_membership(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_lvl_ip_update_membership(env, descP, eVal,
+                                                 IP_DROP_MEMBERSHIP);
+}
+#endif
+
+
+
+/* esock_setopt_lvl_ip_drop_source_membership - 
+ * Level IP DROP_SOURCE_MEMBERSHIP option
+ *
+ * The value is a map with three attributes: multiaddr, interface and
+ * sourceaddr.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is always a 4-tuple (IPv4 address).
+ * The attribute 'sourceaddr' is always a 4-tuple (IPv4 address).
+ * (IPv4 address).
+ */
+#if defined(IP_DROP_SOURCE_MEMBERSHIP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_drop_source_membership(ErlNifEnv*       env,
+                                                        ESockDescriptor* descP,
+                                                        ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_lvl_ip_update_source(env, descP, eVal,
+                                             IP_DROP_SOURCE_MEMBERSHIP);
+}
+#endif
+
+
+
+/* esock_setopt_lvl_ip_freebind - Level IP FREEBIND option
+ */
+#if defined(IP_FREEBIND)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_freebind(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_FREEBIND, eVal);
+}
+#endif
+
+
+
+/* esock_setopt_lvl_ip_hdrincl - Level IP HDRINCL option
+ */
+#if defined(IP_HDRINCL)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_hdrincl(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_HDRINCL, eVal);
+}
+#endif
+
+
+
+/* esock_setopt_lvl_ip_minttl - Level IP MINTTL option
+ */
+#if defined(IP_MINTTL)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_minttl(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_int_opt(env, descP, level, IP_MINTTL, eVal);
+}
+#endif
+
+
+
+/* esock_setopt_lvl_ip_msfilter - Level IP MSFILTER option
+ *
+ * The value can be *either* the atom 'null' or a map of type ip_msfilter().
+ */
+#if defined(IP_MSFILTER) && defined(IP_MSFILTER_SIZE)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_msfilter(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    if (COMPARE(eVal, atom_null) == 0) {
+        return esock_setopt_lvl_ip_msfilter_set(env, descP->sock, NULL, 0);
+    } else {
+        struct ip_msfilter* msfP;
+        Uint32              msfSz;
+        ERL_NIF_TERM        eMultiAddr, eInterface, eFMode, eSList, elem, tail;
+        size_t              sz;
+        unsigned int        slistLen, idx;
+
+        if (!IS_MAP(env, eVal))
+            return esock_make_error(env, esock_atom_einval);
+        
+        // It must have atleast four attributes
+        if (!enif_get_map_size(env, eVal, &sz) || (sz < 4))
+            return esock_make_error(env, esock_atom_einval);
+
+        if (!GET_MAP_VAL(env, eVal, atom_multiaddr, &eMultiAddr))
+            return esock_make_error(env, esock_atom_einval);
+        
+        if (!GET_MAP_VAL(env, eVal, atom_interface, &eInterface))
+            return esock_make_error(env, esock_atom_einval);
+        
+        if (!GET_MAP_VAL(env, eVal, atom_mode, &eFMode))
+            return esock_make_error(env, esock_atom_einval);
+        
+        if (!GET_MAP_VAL(env, eVal, atom_slist, &eSList))
+            return esock_make_error(env, esock_atom_einval);
+
+        /* We start (decoding) with the slist, since without it we don't
+         * really know how much (memory) to allocate.
+         */
+        if (!GET_LIST_LEN(env, eSList, &slistLen))
+            return esock_make_error(env, esock_atom_einval);
+
+        msfSz = IP_MSFILTER_SIZE(slistLen);
+        msfP  = MALLOC(msfSz);
+
+        if (!esock_decode_ip4_address(env, eMultiAddr, &msfP->imsf_multiaddr)) {
+            FREE(msfP);
+            return esock_make_error(env, esock_atom_einval);
+        }
+        
+        if (!esock_decode_ip4_address(env, eInterface, &msfP->imsf_interface)) {
+            FREE(msfP);
+            return esock_make_error(env, esock_atom_einval);
+        }
+        
+        if (!decode_ip_msfilter_mode(env, eFMode, (Uint32*) &msfP->imsf_fmode)) {
+            FREE(msfP);
+            return esock_make_error(env, esock_atom_einval);
+        }
+
+        /* And finally, extract the source addresses */
+        msfP->imsf_numsrc = slistLen;
+        for (idx = 0; idx < slistLen; idx++) {
+            if (GET_LIST_ELEM(env, eSList, &elem, &tail)) {
+                if (!esock_decode_ip4_address(env, elem, &msfP->imsf_slist[idx])) {
+                    FREE(msfP);
+                    return esock_make_error(env, esock_atom_einval);
+                } else {
+                    eSList = tail;
+                }
+            }
+        }
+
+        /* And now, finally, set the option */
+        result = esock_setopt_lvl_ip_msfilter_set(env, descP->sock,
+                                                  msfP, msfSz);
+        FREE(msfP);
+        return result;
+    }
+
+}
+
+
+static
+BOOLEAN_T decode_ip_msfilter_mode(ErlNifEnv*   env,
+                                  ERL_NIF_TERM eVal,
+                                  Uint32*      mode)
+{
+    BOOLEAN_T result;
+
+    if (COMPARE(eVal, atom_include) == 0) {
+        *mode  = MCAST_INCLUDE;
+        result = TRUE;        
+    } else if (COMPARE(eVal, atom_exclude) == 0) {
+        *mode  = MCAST_EXCLUDE;
+        result = TRUE;        
+    } else {
+        result = FALSE;
+    }
+
+    return result;
+}
+
+
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_msfilter_set(ErlNifEnv*          env,
+                                              SOCKET              sock,
+                                              struct ip_msfilter* msfP,
+                                              SOCKLEN_T           optLen)
+{
+    ERL_NIF_TERM result;
+    int          res;
+#if defined(SOL_IP)
+    int          level = SOL_IP;
+#else
+    int          level = IPPROTO_IP;
+#endif
+
+    res = socket_setopt(sock, level, IP_MSFILTER, (void*) msfP, optLen);
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+#endif // IP_MSFILTER
+
+
+
+/* esock_setopt_lvl_ip_mtu_discover - Level IP MTU_DISCOVER option
+ *
+ * The value is an atom of the type ip_pmtudisc().
+ */
+#if defined(IP_MTU_DISCOVER)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_mtu_discover(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM   result;
+    int            val;
+    char*          xres;
+    int            res;
+#if defined(SOL_IP)
+    int            level = SOL_IP;
+#else
+    int            level = IPPROTO_IP;
+#endif
+
+    if ((xres = decode_ip_pmtudisc(env, eVal, &val)) != NULL) {
+
+        result = esock_make_error_str(env, xres);
+
+    } else {
+
+        res = socket_setopt(descP->sock, level, IP_MTU_DISCOVER,
+                            &val, sizeof(val));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    }
+
+    return result;
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_multicast_all - Level IP MULTICAST_ALL option
+ */
+#if defined(IP_MULTICAST_ALL)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_multicast_all(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_MULTICAST_ALL, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_multicast_if - Level IP MULTICAST_IF option
+ *
+ * The value is either the atom 'any' or a 4-tuple.
+ */
+#if defined(IP_MULTICAST_IF)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_multicast_if(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM   result;
+    struct in_addr ifAddr;
+    char*          xres;
+    int            res;
+#if defined(SOL_IP)
+    int            level = SOL_IP;
+#else
+    int            level = IPPROTO_IP;
+#endif
+
+    if ((xres = esock_decode_ip4_address(env, eVal, &ifAddr)) != NULL) {
+        result = esock_make_error_str(env, xres);
+    } else {
+        
+        res = socket_setopt(descP->sock, level, IP_MULTICAST_LOOP,
+                            &ifAddr, sizeof(ifAddr));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    }
+
+    return result;
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_multicast_loop - Level IP MULTICAST_LOOP option
+ */
+#if defined(IP_MULTICAST_LOOP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_multicast_loop(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_MULTICAST_LOOP, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_multicast_ttl - Level IP MULTICAST_TTL option
+ */
+#if defined(IP_MULTICAST_TTL)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_multicast_ttl(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_int_opt(env, descP, level, IP_MULTICAST_TTL, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_nodefrag - Level IP NODEFRAG option
+ */
+#if defined(IP_NODEFRAG)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_nodefrag(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_NODEFRAG, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_pktinfo - Level IP PKTINFO option
+ */
+#if defined(IP_PKTINFO)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_pktinfo(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_PKTINFO, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_recvdstaddr - Level IP RECVDSTADDR option
+ */
+#if defined(IP_RECVDSTADDR)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_recvdstaddr(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_RECVDSTADDR, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_recverr - Level IP RECVERR option
+ */
+#if defined(IP_RECVERR)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_recverr(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_RECVERR, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_recvif - Level IP RECVIF option
+ */
+#if defined(IP_RECVIF)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_recvif(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_RECVIF, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_recvopts - Level IP RECVOPTS option
+ */
+#if defined(IP_RECVOPTS)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_recvopts(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_RECVOPTS, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_recvorigdstaddr - Level IP RECVORIGDSTADDR option
+ */
+#if defined(IP_RECVORIGDSTADDR)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_recvorigdstaddr(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP,
+                                                 ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_RECVORIGDSTADDR, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_recvtos - Level IP RECVTOS option
+ */
+#if defined(IP_RECVTOS)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_recvtos(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_RECVTOS, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_recvttl - Level IP RECVTTL option
+ */
+#if defined(IP_RECVTTL)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_recvttl(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_RECVTTL, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_retopts - Level IP RETOPTS option
+ */
+#if defined(IP_RETOPTS)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_retopts(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_RETOPTS, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_router_alert - Level IP ROUTER_ALERT option
+ */
+#if defined(IP_ROUTER_ALERT)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_router_alert(ErlNifEnv*       env,
+                                              ESockDescriptor* descP,
+                                              ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_int_opt(env, descP, level, IP_ROUTER_ALERT, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_sendsrcaddr - Level IP SENDSRCADDR option
+ */
+#if defined(IP_SENDSRCADDR)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_sendsrcaddr(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_SENDSRCADDR, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_tos - Level IP TOS option
+ */
+#if defined(IP_TOS)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_tos(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int          level = SOL_IP;
+#else
+    int          level = IPPROTO_IP;
+#endif
+    ERL_NIF_TERM result;
+    int          val;
+
+    if (decode_ip_tos(env, eVal, &val)) {
+        int res = socket_setopt(descP->sock, level, IP_TOS, &val, sizeof(val));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    return result;
+}
+#endif
+
+
+/* esock_setopt_lvl_ip_transparent - Level IP TRANSPARENT option
+ */
+#if defined(IP_TRANSPARENT)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_transparent(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IP_TRANSPARENT, eVal);
+}
+#endif
+
+
+
+/* esock_setopt_lvl_ip_ttl - Level IP TTL option
+ */
+#if defined(IP_TTL)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_ttl(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_setopt_int_opt(env, descP, level, IP_TTL, eVal);
+}
+#endif
+
+
+
+/* esock_setopt_lvl_ip_unblock_source - Level IP UNBLOCK_SOURCE option
+ *
+ * The value is a map with three attributes: multiaddr, interface and
+ * sourceaddr.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is always a 4-tuple (IPv4 address).
+ * The attribute 'sourceaddr' is always a 4-tuple (IPv4 address).
+ * (IPv4 address).
+ */
+#if defined(IP_UNBLOCK_SOURCE)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_unblock_source(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_lvl_ip_update_source(env, descP, eVal,
+                                             IP_UNBLOCK_SOURCE);
+}
+#endif
+
+
+
+#if defined(IP_ADD_MEMBERSHIP) || defined(IP_DROP_MEMBERSHIP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_update_membership(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal,
+                                                   int              opt)
+{
+    ERL_NIF_TERM   result, eMultiAddr, eInterface;
+    struct ip_mreq mreq;
+    char*          xres;
+    int            res;
+    size_t         sz;
+#if defined(SOL_IP)
+    int            level = SOL_IP;
+#else
+    int            level = IPPROTO_IP;
+#endif
+
+    // It must be a map
+    if (!IS_MAP(env, eVal)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ip_update_membership -> "
+                "value *not* a map\r\n") );
+        return enif_make_badarg(env);
+    }
+
+    // It must have atleast two attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 2)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ip_update_membership -> "
+                "invalid map value: %T\r\n", eVal) );
+        return enif_make_badarg(env);
+    }
+
+    if (!GET_MAP_VAL(env, eVal, atom_multiaddr, &eMultiAddr)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ip_update_membership -> "
+                "failed get multiaddr (map) attribute\r\n") );
+        return enif_make_badarg(env);
+    }
+
+    if (!GET_MAP_VAL(env, eVal, atom_interface, &eInterface)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ip_update_membership -> "
+                "failed get interface (map) attribute\r\n") );
+        return enif_make_badarg(env);
+    }
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eMultiAddr,
+                                         &mreq.imr_multiaddr)) != NULL) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ip_update_membership -> "
+                "failed decode multiaddr %T: %s\r\n", eMultiAddr, xres) );
+        return esock_make_error_str(env, xres);
+    }
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eInterface,
+                                         &mreq.imr_interface)) != NULL) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ip_update_membership -> "
+                "failed decode interface %T: %s\r\n", eInterface, xres) );
+        return esock_make_error_str(env, xres);
+    }
+
+    res = socket_setopt(descP->sock, level, opt, &mreq, sizeof(mreq));
+
+    if (res != 0) {
+        int save_errno = sock_errno();
+
+        result = esock_make_error_errno(env, save_errno);
+
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ip_update_membership -> "
+                "failed setopt: %T (%d)\r\n", result, save_errno) );
+
+    } else {
+        result = esock_atom_ok;
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(IP_ADD_SOURCE_MEMBERSHIP) || defined(IP_DROP_SOURCE_MEMBERSHIP) || defined(IP_BLOCK_SOURCE) || defined(IP_UNBLOCK_SOURCE)
+static
+ERL_NIF_TERM esock_setopt_lvl_ip_update_source(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               ERL_NIF_TERM     eVal,
+                                               int              opt)
+{
+    ERL_NIF_TERM          result, eMultiAddr, eInterface, eSourceAddr;
+    struct ip_mreq_source mreq;
+    char*                 xres;
+    int                   res;
+    size_t                sz;
+#if defined(SOL_IP)
+    int            level = SOL_IP;
+#else
+    int            level = IPPROTO_IP;
+#endif
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return enif_make_badarg(env);
+
+    // It must have atleast three attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz >= 3))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_multiaddr, &eMultiAddr))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_interface, &eInterface))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_sourceaddr, &eSourceAddr))
+        return enif_make_badarg(env);
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eMultiAddr,
+                                         &mreq.imr_multiaddr)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eInterface,
+                                         &mreq.imr_interface)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eSourceAddr,
+                                         &mreq.imr_sourceaddr)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    res = socket_setopt(descP->sock, level, opt, &mreq, sizeof(mreq));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+#endif
+
+
+
+/* *** Handling set of socket options for level = ipv6 *** */
+
+/* esock_setopt_lvl_ipv6 - Level *IPv6* option(s)
+ */
+#if defined(HAVE_IPV6)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   int              eOpt,
+                                   ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_ipv6 -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(IPV6_ADDRFORM)
+    case ESOCK_OPT_IPV6_ADDRFORM:
+        result = esock_setopt_lvl_ipv6_addrform(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_ADD_MEMBERSHIP)
+    case ESOCK_OPT_IPV6_ADD_MEMBERSHIP:
+        result = esock_setopt_lvl_ipv6_add_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_AUTHHDR)
+    case ESOCK_OPT_IPV6_AUTHHDR:
+        result = esock_setopt_lvl_ipv6_authhdr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_DROP_MEMBERSHIP)
+    case ESOCK_OPT_IPV6_DROP_MEMBERSHIP:
+        result = esock_setopt_lvl_ipv6_drop_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_DSTOPTS)
+    case ESOCK_OPT_IPV6_DSTOPTS:
+        result = esock_setopt_lvl_ipv6_dstopts(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_FLOWINFO)
+    case ESOCK_OPT_IPV6_FLOWINFO:
+        result = esock_setopt_lvl_ipv6_flowinfo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_HOPLIMIT)
+    case ESOCK_OPT_IPV6_HOPLIMIT:
+        result = esock_setopt_lvl_ipv6_hoplimit(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_HOPOPTS)
+    case ESOCK_OPT_IPV6_HOPOPTS:
+        result = esock_setopt_lvl_ipv6_hopopts(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MTU)
+    case ESOCK_OPT_IPV6_MTU:
+        result = esock_setopt_lvl_ipv6_mtu(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MTU_DISCOVER)
+    case ESOCK_OPT_IPV6_MTU_DISCOVER:
+        result = esock_setopt_lvl_ipv6_mtu_discover(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_HOPS)
+    case ESOCK_OPT_IPV6_MULTICAST_HOPS:
+        result = esock_setopt_lvl_ipv6_multicast_hops(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_IF)
+    case ESOCK_OPT_IPV6_MULTICAST_IF:
+        result = esock_setopt_lvl_ipv6_multicast_if(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_LOOP)
+    case ESOCK_OPT_IPV6_MULTICAST_LOOP:
+        result = esock_setopt_lvl_ipv6_multicast_loop(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_RECVERR)
+    case ESOCK_OPT_IPV6_RECVERR:
+        result = esock_setopt_lvl_ipv6_recverr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+    case ESOCK_OPT_IPV6_RECVPKTINFO:
+        result = esock_setopt_lvl_ipv6_recvpktinfo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_ROUTER_ALERT)
+    case ESOCK_OPT_IPV6_ROUTER_ALERT:
+        result = esock_setopt_lvl_ipv6_router_alert(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_RTHDR)
+    case ESOCK_OPT_IPV6_RTHDR:
+        result = esock_setopt_lvl_ipv6_rthdr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_UNICAST_HOPS)
+    case ESOCK_OPT_IPV6_UNICAST_HOPS:
+        result = esock_setopt_lvl_ipv6_unicast_hops(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_V6ONLY)
+    case ESOCK_OPT_IPV6_V6ONLY:
+        result = esock_setopt_lvl_ipv6_v6only(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        SSDBG( descP,
+               ("SOCKET",
+                "esock_setopt_lvl_ipv6 -> unknown opt (%d)\r\n", eOpt) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_ipv6 -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+#if defined(IPV6_ADDRFORM)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_addrform(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+    int          res, edomain, domain;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_ipv6_addrform -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    if (!GET_INT(env, eVal, &edomain))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_ipv6_addrform -> decode"
+            "\r\n   edomain: %d"
+            "\r\n", edomain) );
+
+    if (!edomain2domain(edomain, &domain))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP, ("SOCKET",
+                   "esock_setopt_lvl_ipv6_addrform -> try set opt to %d\r\n",
+                   domain) );
+    
+    res = socket_setopt(descP->sock,
+                        SOL_IPV6, IPV6_ADDRFORM,
+                        &domain, sizeof(domain));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+#endif
+
+
+#if defined(IPV6_ADD_MEMBERSHIP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_add_membership(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_lvl_ipv6_update_membership(env, descP, eVal,
+                                              IPV6_ADD_MEMBERSHIP);
+}
+#endif
+
+
+#if defined(IPV6_AUTHHDR)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_authhdr(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, SOL_IPV6, IPV6_AUTHHDR, eVal);
+}
+#endif
+
+
+#if defined(IPV6_DROP_MEMBERSHIP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_drop_membership(ErlNifEnv*       env,
+                                                   ESockDescriptor* descP,
+                                                   ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_lvl_ipv6_update_membership(env, descP, eVal,
+                                              IPV6_DROP_MEMBERSHIP);
+}
+#endif
+
+
+#if defined(IPV6_DSTOPTS)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_dstopts(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IPV6_DSTOPTS, eVal);
+}
+#endif
+
+
+#if defined(IPV6_FLOWINFO)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_flowinfo(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IPV6_FLOWINFO, eVal);
+}
+#endif
+
+
+#if defined(IPV6_HOPLIMIT)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_hoplimit(ErlNifEnv*       env,
+                                            ESockDescriptor* descP,
+                                            ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IPV6_HOPLIMIT, eVal);
+}
+#endif
+
+
+#if defined(IPV6_HOPOPTS)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_hopopts(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IPV6_HOPOPTS, eVal);
+}
+#endif
+
+
+#if defined(IPV6_MTU)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_mtu(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_int_opt(env, descP, level, IPV6_MTU, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_ipv6_mtu_discover - Level IPv6 MTU_DISCOVER option
+ *
+ * The value is an atom of the type ipv6_pmtudisc().
+ */
+#if defined(IPV6_MTU_DISCOVER)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_mtu_discover(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM  result;
+    int           val;
+    char*         xres;
+    int           res;
+
+    if ((xres = decode_ipv6_pmtudisc(env, eVal, &val)) != NULL) {
+
+        result = esock_make_error_str(env, xres);
+
+    } else {
+#if defined(SOL_IPV6)
+        int level = SOL_IPV6;
+#else
+        int level = IPPROTO_IPV6;
+#endif
+
+
+        res = socket_setopt(descP->sock, level, IPV6_MTU_DISCOVER,
+                            &val, sizeof(val));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(IPV6_MULTICAST_HOPS)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_multicast_hops(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_int_opt(env, descP, level, IPV6_MULTICAST_HOPS, eVal);
+}
+#endif
+
+
+
+#if defined(IPV6_MULTICAST_IF)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_multicast_if(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_int_opt(env, descP, level, IPV6_MULTICAST_IF, eVal);
+}
+#endif
+
+
+
+#if defined(IPV6_MULTICAST_LOOP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_multicast_loop(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP,
+                                                  ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IPV6_MULTICAST_LOOP, eVal);
+}
+#endif
+
+
+#if defined(IPV6_RECVERR)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_recverr(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IPV6_RECVERR, eVal);
+}
+#endif
+
+
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_recvpktinfo(ErlNifEnv*       env,
+                                               ESockDescriptor* descP,
+                                               ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+#if defined(IPV6_RECVPKTINFO)
+    int opt = IPV6_RECVPKTINFO;
+#else
+    int opt = IPV6_PKTINFO;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, opt, eVal);
+}
+#endif
+
+
+#if defined(IPV6_ROUTER_ALERT)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_router_alert(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_int_opt(env, descP, level, IPV6_ROUTER_ALERT, eVal);
+}
+#endif
+
+
+
+#if defined(IPV6_RTHDR)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_rthdr(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IPV6_RTHDR, eVal);
+}
+#endif
+
+
+#if defined(IPV6_UNICAST_HOPS)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_unicast_hops(ErlNifEnv*       env,
+                                                ESockDescriptor* descP,
+                                                ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_int_opt(env, descP, level, IPV6_UNICAST_HOPS, eVal);
+}
+#endif
+
+
+
+#if defined(IPV6_V6ONLY)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_v6only(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_setopt_bool_opt(env, descP, level, IPV6_V6ONLY, eVal);
+}
+#endif
+
+
+#if defined(IPV6_ADD_MEMBERSHIP) || defined(IPV6_DROP_MEMBERSHIP)
+static
+ERL_NIF_TERM esock_setopt_lvl_ipv6_update_membership(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP,
+                                                     ERL_NIF_TERM     eVal,
+                                                     int              opt)
+{
+    ERL_NIF_TERM     result, eMultiAddr, eInterface;
+    struct ipv6_mreq mreq;
+    char*            xres;
+    int              res;
+    size_t           sz;
+#if defined(SOL_IPV6)
+    int              level = SOL_IPV6;
+#else
+    int              level = IPPROTO_IPV6;
+#endif
+
+    // It must be a map
+    if (!IS_MAP(env, eVal)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ipv6_update_membership -> "
+                "value *not* a map\r\n") );
+        return enif_make_badarg(env);
+    }
+
+    // It must have atleast two attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 2)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ipv6_update_membership -> "
+                "invalid map value: %T\r\n", eVal) );
+        return enif_make_badarg(env);
+    }
+
+    if (!GET_MAP_VAL(env, eVal, atom_multiaddr, &eMultiAddr)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ipv6_update_membership -> "
+                "failed get multiaddr (map) attribute\r\n") );
+        return enif_make_badarg(env);
+    }
+
+    if (!GET_MAP_VAL(env, eVal, atom_interface, &eInterface)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ipv6_update_membership -> "
+                "failed get interface (map) attribute\r\n") );
+        return enif_make_badarg(env);
+    }
+
+    if ((xres = esock_decode_ip6_address(env,
+                                         eMultiAddr,
+                                         &mreq.ipv6mr_multiaddr)) != NULL) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ipv6_update_membership -> "
+                "failed decode multiaddr %T: %s\r\n", eMultiAddr, xres) );
+        return esock_make_error_str(env, xres);
+    }
+
+    if (!GET_UINT(env, eInterface, &mreq.ipv6mr_interface)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ip_update_membership -> "
+                "failed decode interface %T: %s\r\n", eInterface, xres) );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    res = socket_setopt(descP->sock, level, opt, &mreq, sizeof(mreq));
+
+    if (res != 0) {
+        int save_errno = sock_errno();
+
+        result = esock_make_error_errno(env, save_errno);
+
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_lvl_ipv6_update_membership -> "
+                "failed setopt: %T (%d)\r\n", result, save_errno) );
+
+    } else {
+        result = esock_atom_ok;
+    }
+
+    return result;
+}
+#endif
+
+
+
+#endif // defined(HAVE_IPV6)
+
+
+
+/* esock_setopt_lvl_tcp - Level *TCP* option(s)
+ */
+static
+ERL_NIF_TERM esock_setopt_lvl_tcp(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              eOpt,
+                                  ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_tcp -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(TCP_CONGESTION)
+    case ESOCK_OPT_TCP_CONGESTION:
+        result = esock_setopt_lvl_tcp_congestion(env, descP, eVal);
+        break;
+#endif
+
+#if defined(TCP_MAXSEG)
+    case ESOCK_OPT_TCP_MAXSEG:
+        result = esock_setopt_lvl_tcp_maxseg(env, descP, eVal);
+        break;
+#endif
+
+#if defined(TCP_NODELAY)
+    case ESOCK_OPT_TCP_NODELAY:
+        result = esock_setopt_lvl_tcp_nodelay(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* esock_setopt_lvl_tcp_congestion - Level TCP CONGESTION option
+ */
+#if defined(TCP_CONGESTION)
+static
+ERL_NIF_TERM esock_setopt_lvl_tcp_congestion(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    int max = ESOCK_OPT_TCP_CONGESTION_NAME_MAX+1;
+
+    return esock_setopt_str_opt(env, descP,
+                                IPPROTO_TCP, TCP_CONGESTION, max, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_tcp_maxseg - Level TCP MAXSEG option
+ */
+#if defined(TCP_MAXSEG)
+static
+ERL_NIF_TERM esock_setopt_lvl_tcp_maxseg(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP, IPPROTO_TCP, TCP_MAXSEG, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_tcp_nodelay - Level TCP NODELAY option
+ */
+#if defined(TCP_NODELAY)
+static
+ERL_NIF_TERM esock_setopt_lvl_tcp_nodelay(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, IPPROTO_TCP, TCP_NODELAY, eVal);
+}
+#endif
+
+
+
+/* esock_setopt_lvl_udp - Level *UDP* option(s)
+ */
+static
+ERL_NIF_TERM esock_setopt_lvl_udp(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              eOpt,
+                                  ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_udp -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(UDP_CORK)
+    case ESOCK_OPT_UDP_CORK:
+        result = esock_setopt_lvl_udp_cork(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* esock_setopt_lvl_udp_cork - Level UDP CORK option
+ */
+#if defined(UDP_CORK)
+static
+ERL_NIF_TERM esock_setopt_lvl_udp_cork(ErlNifEnv*       env,
+                                       ESockDescriptor* descP,
+                                       ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, IPPROTO_UDP, UDP_CORK, eVal);
+}
+#endif
+
+
+
+
+/* esock_setopt_lvl_sctp - Level *SCTP* option(s)
+ */
+#if defined(HAVE_SCTP)
+static
+ERL_NIF_TERM esock_setopt_lvl_sctp(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   int              eOpt,
+                                   ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sctp -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(SCTP_ASSOCINFO)
+    case ESOCK_OPT_SCTP_ASSOCINFO:
+        result = esock_setopt_lvl_sctp_associnfo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_AUTOCLOSE)
+    case ESOCK_OPT_SCTP_AUTOCLOSE:
+        result = esock_setopt_lvl_sctp_autoclose(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_DISABLE_FRAGMENTS)
+    case ESOCK_OPT_SCTP_DISABLE_FRAGMENTS:
+        result = esock_setopt_lvl_sctp_disable_fragments(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_EVENTS)
+    case ESOCK_OPT_SCTP_EVENTS:
+        result = esock_setopt_lvl_sctp_events(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_INITMSG)
+    case ESOCK_OPT_SCTP_INITMSG:
+        result = esock_setopt_lvl_sctp_initmsg(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_MAXSEG)
+    case ESOCK_OPT_SCTP_MAXSEG:
+        result = esock_setopt_lvl_sctp_maxseg(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_NODELAY)
+    case ESOCK_OPT_SCTP_NODELAY:
+        result = esock_setopt_lvl_sctp_nodelay(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_RTOINFO)
+    case ESOCK_OPT_SCTP_RTOINFO:
+        result = esock_setopt_lvl_sctp_rtoinfo(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* esock_setopt_lvl_sctp_associnfo - Level SCTP ASSOCINFO option
+ */
+#if defined(SCTP_ASSOCINFO)
+static
+ERL_NIF_TERM esock_setopt_lvl_sctp_associnfo(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM            result;
+    ERL_NIF_TERM            eAssocId, eMaxRxt, eNumPeerDests;
+    ERL_NIF_TERM            ePeerRWND, eLocalRWND, eCookieLife;
+    struct sctp_assocparams assocParams;
+    int                     res;
+    size_t                  sz;
+    unsigned int            tmp;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sctp_associnfo -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return esock_make_error(env, esock_atom_einval);
+
+    // It must have atleast ten attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 6))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_associnfo -> extract attributes\r\n") );    
+
+    if (!GET_MAP_VAL(env, eVal, atom_assoc_id,          &eAssocId))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max_rxt,        &eMaxRxt))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_num_peer_dests, &eNumPeerDests))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_peer_rwnd,      &ePeerRWND))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_local_rwnd,     &eLocalRWND))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_cookie_life,    &eCookieLife))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_associnfo -> decode attributes\r\n") );
+
+    /* On some platforms the assoc id is typed as an unsigned integer (uint32)
+     * So, to avoid warnings there, we always make an explicit cast... 
+     * Also, size of types matter, so adjust for that...
+     */
+
+#if (SIZEOF_INT == 4)
+    {
+        int tmpAssocId;
+        if (!GET_INT(env, eAssocId, &tmpAssocId))
+            return esock_make_error(env, esock_atom_einval);
+        assocParams.sasoc_assoc_id =
+            (typeof(assocParams.sasoc_assoc_id)) tmpAssocId;
+    }
+#elif (SIZEOF_LONG == 4)
+    {
+        long tmpAssocId;
+        if (!GET_LONG(env, eAssocId, &tmpAssocId))
+            return esock_make_error(env, esock_atom_einval);
+        assocParams.sasoc_assoc_id =
+            (typeof(assocParams.sasoc_assoc_id)) tmpAssocId;
+    }
+#else
+    SIZE CHECK FOR ASSOC ID FAILED
+#endif
+
+    
+    /*
+     * We should really make sure this is ok in erlang (to ensure that 
+     * the values (max-rxt and num-peer-dests) fits in 16-bits).
+     * The value should be a 16-bit unsigned int...
+     * Both sasoc_asocmaxrxt and sasoc_number_peer_destinations.
+     */
+    
+    if (!GET_UINT(env, eMaxRxt, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    assocParams.sasoc_asocmaxrxt = (Uint16) tmp;
+
+    if (!GET_UINT(env, eNumPeerDests, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    assocParams.sasoc_number_peer_destinations = (Uint16) tmp;
+
+    if (!GET_UINT(env, ePeerRWND, &assocParams.sasoc_peer_rwnd))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_UINT(env, eLocalRWND, &assocParams.sasoc_local_rwnd))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_UINT(env, eCookieLife, &assocParams.sasoc_cookie_life))
+        return esock_make_error(env, esock_atom_einval);
+    
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_associnfo -> set associnfo option\r\n") );
+
+    res = socket_setopt(descP->sock, IPPROTO_SCTP, SCTP_ASSOCINFO,
+                        &assocParams, sizeof(assocParams));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sctp_associnfo -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+#endif
+
+
+/* esock_setopt_lvl_sctp_autoclose - Level SCTP AUTOCLOSE option
+ */
+#if defined(SCTP_AUTOCLOSE)
+static
+ERL_NIF_TERM esock_setopt_lvl_sctp_autoclose(ErlNifEnv*       env,
+                                             ESockDescriptor* descP,
+                                             ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP,
+                                IPPROTO_SCTP, SCTP_AUTOCLOSE, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_sctp_disable_fragments -
+ * Level SCTP DISABLE_FRAGMENTS option
+ */
+#if defined(SCTP_DISABLE_FRAGMENTS)
+static
+ERL_NIF_TERM esock_setopt_lvl_sctp_disable_fragments(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP,
+                                                     ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP,
+                                 IPPROTO_SCTP, SCTP_DISABLE_FRAGMENTS, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_sctp_events - Level SCTP EVENTS option
+ */
+#if defined(SCTP_EVENTS)
+static
+ERL_NIF_TERM esock_setopt_lvl_sctp_events(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM                result;
+    ERL_NIF_TERM                eDataIn, eAssoc, eAddr, eSndFailure;
+    ERL_NIF_TERM                ePeerError, eShutdown, ePartialDelivery;
+    ERL_NIF_TERM                eAdaptLayer;
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_AUTHENTICATION_EVENT)
+    ERL_NIF_TERM                eAuth;
+#endif
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_SENDER_DRY_EVENT)
+    ERL_NIF_TERM                eSndDry;
+#endif
+    struct sctp_event_subscribe events;
+    int                         res;
+    size_t                      sz;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sctp_events -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return esock_make_error(env, esock_atom_einval);
+
+    // It must have atleast ten attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 10))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_events -> extract attributes\r\n") );    
+
+    if (!GET_MAP_VAL(env, eVal, atom_data_in,          &eDataIn))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_association,      &eAssoc))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_address,          &eAddr))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_send_failure,     &eSndFailure))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_peer_error,       &ePeerError))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_shutdown,         &eShutdown))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_partial_delivery, &ePartialDelivery))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_adaptation_layer, &eAdaptLayer))
+        return esock_make_error(env, esock_atom_einval);
+
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_AUTHENTICATION_EVENT)
+    if (!GET_MAP_VAL(env, eVal, atom_authentication,   &eAuth))
+        return esock_make_error(env, esock_atom_einval);
+#endif
+
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_SENDER_DRY_EVENT)
+    if (!GET_MAP_VAL(env, eVal, atom_sender_dry,       &eSndDry))
+        return esock_make_error(env, esock_atom_einval);
+#endif
+
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_events -> decode attributes\r\n") );
+
+    events.sctp_data_io_event          = esock_decode_bool(eDataIn);
+    events.sctp_association_event      = esock_decode_bool(eAssoc);
+    events.sctp_address_event          = esock_decode_bool(eAddr);
+    events.sctp_send_failure_event     = esock_decode_bool(eSndFailure);
+    events.sctp_peer_error_event       = esock_decode_bool(ePeerError);
+    events.sctp_shutdown_event         = esock_decode_bool(eShutdown);
+    events.sctp_partial_delivery_event = esock_decode_bool(ePartialDelivery);
+    events.sctp_adaptation_layer_event = esock_decode_bool(eAdaptLayer);
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_AUTHENTICATION_EVENT)
+    events.sctp_authentication_event   = esock_decode_bool(eAuth);
+#endif
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_SENDER_DRY_EVENT)
+    events.sctp_sender_dry_event       = esock_decode_bool(eSndDry);
+#endif
+    
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_events -> set events option\r\n") );
+
+    res = socket_setopt(descP->sock, IPPROTO_SCTP, SCTP_EVENTS,
+                        &events, sizeof(events));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sctp_events -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+#endif
+
+
+/* esock_setopt_lvl_sctp_initmsg - Level SCTP INITMSG option
+ */
+#if defined(SCTP_INITMSG)
+static
+ERL_NIF_TERM esock_setopt_lvl_sctp_initmsg(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM        result;
+    ERL_NIF_TERM        eNumOut, eMaxIn, eMaxAttempts, eMaxInitTO;
+    struct sctp_initmsg initMsg;
+    int                 res;
+    size_t              sz;
+    unsigned int        tmp;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sctp_initmsg -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return esock_make_error(env, esock_atom_einval);
+
+    // It must have atleast ten attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 4))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_initmsg -> extract attributes\r\n") );    
+
+    if (!GET_MAP_VAL(env, eVal, atom_num_outstreams, &eNumOut))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max_instreams,  &eMaxIn))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max_attempts,   &eMaxAttempts))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max_init_timeo, &eMaxInitTO))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_initmsg -> decode attributes\r\n") );
+
+    if (!GET_UINT(env, eNumOut, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    initMsg.sinit_num_ostreams = (Uint16) tmp;
+    
+    if (!GET_UINT(env, eMaxIn, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    initMsg.sinit_max_instreams = (Uint16) tmp;
+    
+    if (!GET_UINT(env, eMaxAttempts, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    initMsg.sinit_max_attempts = (Uint16) tmp;
+    
+    if (!GET_UINT(env, eMaxInitTO, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    initMsg.sinit_max_init_timeo = (Uint16) tmp;
+    
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_initmsg -> set initmsg option\r\n") );
+
+    res = socket_setopt(descP->sock, IPPROTO_SCTP, SCTP_INITMSG,
+                        &initMsg, sizeof(initMsg));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sctp_initmsg -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+#endif
+
+
+/* esock_setopt_lvl_sctp_maxseg - Level SCTP MAXSEG option
+ */
+#if defined(SCTP_MAXSEG)
+static
+ERL_NIF_TERM esock_setopt_lvl_sctp_maxseg(ErlNifEnv*       env,
+                                          ESockDescriptor* descP,
+                                          ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_int_opt(env, descP, IPPROTO_SCTP, SCTP_MAXSEG, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_sctp_nodelay - Level SCTP NODELAY option
+ */
+#if defined(SCTP_NODELAY)
+static
+ERL_NIF_TERM esock_setopt_lvl_sctp_nodelay(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     eVal)
+{
+    return esock_setopt_bool_opt(env, descP, IPPROTO_SCTP, SCTP_NODELAY, eVal);
+}
+#endif
+
+
+/* esock_setopt_lvl_sctp_rtoinfo - Level SCTP RTOINFO option
+ */
+#if defined(SCTP_RTOINFO)
+static
+ERL_NIF_TERM esock_setopt_lvl_sctp_rtoinfo(ErlNifEnv*       env,
+                                           ESockDescriptor* descP,
+                                           ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM        result;
+    ERL_NIF_TERM        eAssocId, eInitial, eMax, eMin;
+    struct sctp_rtoinfo rtoInfo;
+    int                 res;
+    size_t              sz;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sctp_rtoinfo -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return esock_make_error(env, esock_atom_einval);
+
+    // It must have atleast ten attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 4))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_rtoinfo -> extract attributes\r\n") );    
+
+    if (!GET_MAP_VAL(env, eVal, atom_assoc_id, &eAssocId))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_initial,  &eInitial))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max,      &eMax))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_min,      &eMin))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_rtoinfo -> decode attributes\r\n") );
+
+    /* On some platforms the assoc id is typed as an unsigned integer (uint32)
+     * So, to avoid warnings there, we always make an explicit cast... 
+     * Also, size of types matter, so adjust for that...
+     */
+
+#if (SIZEOF_INT == 4)
+    {
+        int tmpAssocId;
+        if (!GET_INT(env, eAssocId, &tmpAssocId))
+            return esock_make_error(env, esock_atom_einval);
+        rtoInfo.srto_assoc_id = (typeof(rtoInfo.srto_assoc_id)) tmpAssocId;
+    }
+#elif (SIZEOF_LONG == 4)
+    {
+        long tmpAssocId;
+        if (!GET_LONG(env, eAssocId, &tmpAssocId))
+            return esock_make_error(env, esock_atom_einval);
+        rtoInfo.srto_assoc_id = (typeof(rtoInfo.srto_assoc_id)) tmpAssocId;
+    }
+#else
+    SIZE CHECK FOR ASSOC ID FAILED
+#endif
+    
+    if (!GET_UINT(env, eInitial, &rtoInfo.srto_initial))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_UINT(env, eMax, &rtoInfo.srto_max))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_UINT(env, eMin, &rtoInfo.srto_min))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET",
+            "esock_setopt_lvl_sctp_rtoinfo -> set associnfo option\r\n") );
+
+    res = socket_setopt(descP->sock, IPPROTO_SCTP, SCTP_RTOINFO,
+                        &rtoInfo, sizeof(rtoInfo));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_lvl_sctp_rtoinfo -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+#endif
+
+
+
+#endif // defined(HAVE_SCTP)
+
+
+
+
+/* esock_setopt_bool_opt - set an option that has an (integer) bool value
+ */
+static
+ERL_NIF_TERM esock_setopt_bool_opt(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   int              level,
+                                   int              opt,
+                                   ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+    BOOLEAN_T    val;
+    int          ival, res;
+
+    val = esock_decode_bool(eVal);
+    
+    ival = (val) ? 1 : 0;
+    res  = socket_setopt(descP->sock, level, opt, &ival, sizeof(ival));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+
+
+/* esock_setopt_int_opt - set an option that has an integer value
+ */
+static
+ERL_NIF_TERM esock_setopt_int_opt(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              level,
+                                  int              opt,
+                                  ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+    int          val;
+
+    if (GET_INT(env, eVal, &val)) {
+        int res;
+
+        /*
+        SSDBG( descP,
+               ("SOCKET", "esock_setopt_int_opt -> set option"
+                "\r\n   opt: %d"
+                "\r\n   val: %d"
+                "\r\n", opt, val) );
+        */
+
+        res = socket_setopt(descP->sock, level, opt, &val, sizeof(val));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    return result;
+}
+
+
+/* esock_setopt_str_opt - set an option that has an string value
+ */
+#if defined(USE_SETOPT_STR_OPT)
+static
+ERL_NIF_TERM esock_setopt_str_opt(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              level,
+                                  int              opt,
+                                  int              max,
+                                  ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM result;
+    char*        val = MALLOC(max);
+
+    if (GET_STR(env, eVal, val, max) > 0) {
+        int optLen = strlen(val);
+        int res    = socket_setopt(descP->sock, level, opt, &val, optLen);
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    FREE(val);
+
+    return result;
+}
+#endif
+
+
+/* esock_setopt_timeval_opt - set an option that has an (timeval) bool value
+ */
+static
+ERL_NIF_TERM esock_setopt_timeval_opt(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      int              level,
+                                      int              opt,
+                                      ERL_NIF_TERM     eVal)
+{
+    ERL_NIF_TERM   result;
+    struct timeval timeVal;
+    int            res;
+    char*          xres;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_timeval_opt -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    if ((xres = esock_decode_timeval(env, eVal, &timeVal)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_timeval_opt -> set timeval option\r\n") );
+
+    res = socket_setopt(descP->sock, level, opt, &timeVal, sizeof(timeVal));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_setopt_timeval_opt -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+
+
+
+static
+BOOLEAN_T elevel2level(BOOLEAN_T  isEncoded,
+                       int        eLevel,
+                       BOOLEAN_T* isOTP,
+                       int*       level)
+{
+    BOOLEAN_T result;
+
+    if (isEncoded) {
+        switch (eLevel) {
+        case ESOCK_OPT_LEVEL_OTP:
+            *isOTP = TRUE;
+            *level = -1;
+            result = TRUE;
+            break;
+
+        case ESOCK_OPT_LEVEL_SOCKET:
+            *isOTP = FALSE;
+            *level = SOL_SOCKET;
+            result = TRUE;
+            break;
+
+        case ESOCK_OPT_LEVEL_IP:
+            *isOTP = FALSE;
+#if defined(SOL_IP)
+            *level = SOL_IP;
+#else
+            *level = IPPROTO_IP;
+#endif
+            result = TRUE;
+            break;
+
+#if defined(HAVE_IPV6)
+        case ESOCK_OPT_LEVEL_IPV6:
+            *isOTP = FALSE;
+#if defined(SOL_IPV6)
+            *level = SOL_IPV6;
+#else
+            *level = IPPROTO_IPV6;
+#endif
+            result = TRUE;
+            break;
+#endif
+
+        case ESOCK_OPT_LEVEL_TCP:
+            *isOTP = FALSE;
+            *level = IPPROTO_TCP;
+            result = TRUE;
+            break;
+
+        case ESOCK_OPT_LEVEL_UDP:
+            *isOTP = FALSE;
+            *level = IPPROTO_UDP;
+            result = TRUE;
+            break;
+
+#ifdef HAVE_SCTP
+        case ESOCK_OPT_LEVEL_SCTP:
+            *isOTP = FALSE;
+            *level = IPPROTO_SCTP;
+            result = TRUE;
+            break;
+#endif
+
+        default:
+            *isOTP = FALSE;
+            *level = -1;
+            result = FALSE;
+            break;
+        }
+    } else {
+        *isOTP = FALSE;
+        *level = eLevel;
+        result = TRUE;
+    }
+
+    return result;
+}
+
+
+
+/* +++ socket_setopt +++
+ *
+ * <Per H @ Tail-f>
+ * The original code here had problems that possibly
+ * only occur if you abuse it for non-INET sockets, but anyway:
+ * a) If the getsockopt for SO_PRIORITY or IP_TOS failed, the actual
+ *    requested setsockopt was never even attempted.
+ * b) If {get,set}sockopt for one of IP_TOS and SO_PRIORITY failed,
+ *    but ditto for the other worked and that was actually the requested
+ *    option, failure was still reported to erlang.
+ * </Per H @ Tail-f>
+ *
+ * <PaN>
+ * The relations between SO_PRIORITY, TOS and other options
+ * is not what you (or at least I) would expect...:
+ * If TOS is set after priority, priority is zeroed.
+ * If any other option is set after tos, tos might be zeroed.
+ * Therefore, save tos and priority. If something else is set,
+ * restore both after setting, if  tos is set, restore only
+ * prio and if prio is set restore none... All to keep the
+ * user feeling socket options are independent.
+ * </PaN>
+ */
+static
+int socket_setopt(int sock, int level, int opt,
+                  const void* optVal, const socklen_t optLen)
+{
+    int res;
+
+#if  defined(IP_TOS) && defined(SOL_IP) && defined(SO_PRIORITY)
+    int          tmpIValPRIO;
+    int          tmpIValTOS;
+    int          resPRIO;
+    int          resTOS;
+    SOCKOPTLEN_T tmpArgSzPRIO = sizeof(tmpIValPRIO);
+    SOCKOPTLEN_T tmpArgSzTOS  = sizeof(tmpIValTOS);
+
+    resPRIO = sock_getopt(sock, SOL_SOCKET, SO_PRIORITY,
+                           &tmpIValPRIO, &tmpArgSzPRIO);
+    resTOS  = sock_getopt(sock, SOL_IP, IP_TOS,
+                          &tmpIValTOS, &tmpArgSzTOS);
+
+    res = sock_setopt(sock, level, opt, optVal, optLen);
+    if (res == 0) {
+
+        /* Ok, now we *maybe* need to "maybe" restore PRIO and TOS...
+         * maybe, possibly, ...
+         */
+
+        if (opt != SO_PRIORITY) {
+	    if ((opt != IP_TOS) && (resTOS == 0)) {
+		resTOS = sock_setopt(sock, SOL_IP, IP_TOS,
+                                     (void *) &tmpIValTOS,
+                                     tmpArgSzTOS);
+                res = resTOS;
+            }
+	    if ((res == 0) && (resPRIO == 0)) {
+		resPRIO = sock_setopt(sock, SOL_SOCKET, SO_PRIORITY,
+                                      &tmpIValPRIO,
+                                      tmpArgSzPRIO);
+
+                /* Some kernels set a SO_PRIORITY by default
+                 * that you are not permitted to reset,
+                 * silently ignore this error condition.
+                 */
+
+                if ((resPRIO != 0) && (sock_errno() == EPERM)) {
+                    res = 0;
+                } else {
+                    res = resPRIO;
+		}
+	    }
+	}
+    }
+
+#else
+
+    res = sock_setopt(sock, level, opt, optVal, optLen);
+
+#endif
+
+    return res;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_getopt
+ *
+ * Description:
+ * Get socket option.
+ * Its possible to use a "raw" mode (not encoded). That is, we do not
+ * interpret level and opt. They are passed "as is" to the
+ * getsockopt function call. The value in this case will "copied" as
+ * is and provided to the user in the form of a binary.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * IsEncoded    - Are the "arguments" encoded or not.
+ * Level        - Level of the socket option.
+ * Opt          - The socket option.
+ */
+
+static
+ERL_NIF_TERM nif_getopt(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    int              eLevel, level = -1;
+    ERL_NIF_TERM     eIsEncoded, eOpt;
+    BOOLEAN_T        isEncoded, isOTP;
+    ERL_NIF_TERM     result;
+
+    SGDBG( ("SOCKET", "nif_getopt -> entry with argc: %d\r\n", argc) );
+
+    if ((argc != 4) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP) ||
+        !GET_INT(env, argv[2], &eLevel)) {
+        SGDBG( ("SOCKET", "nif_getopt -> failed processing args\r\n") );
+        return enif_make_badarg(env);
+    }
+    eIsEncoded = argv[1];
+    eOpt       = argv[3]; // Is "normally" an int, but if raw mode: {Int, ValueSz}
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_getopt -> args when sock = %d:"
+            "\r\n   Socket:     %T"
+            "\r\n   eIsEncoded: %T"
+            "\r\n   eLevel:     %d"
+            "\r\n   eOpt:       %T"
+            "\r\n", descP->sock, argv[0], eIsEncoded, eLevel, eOpt) );
+
+    isEncoded = esock_decode_bool(eIsEncoded);
+
+    if (!elevel2level(isEncoded, eLevel, &isOTP, &level))
+        return esock_make_error(env, esock_atom_einval);
+
+    MLOCK(descP->cfgMtx);
+
+    result = esock_getopt(env, descP, isEncoded, isOTP, level, eOpt);
+    
+    MUNLOCK(descP->cfgMtx);
+
+    return result;
+
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_getopt(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          BOOLEAN_T        isEncoded,
+                          BOOLEAN_T        isOTP,
+                          int              level,
+                          ERL_NIF_TERM     eOpt)
+{
+    ERL_NIF_TERM result;
+    int          opt;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt -> entry with"
+            "\r\n   isEncoded: %s"
+            "\r\n   isOTP:     %s"
+            "\r\n   level:     %d"
+            "\r\n   eOpt:      %T"
+            "\r\n", B2S(isEncoded), B2S(isOTP), level, eOpt) );
+
+    if (isOTP) {
+        /* These are not actual socket options,
+         * but options for our implementation.
+         */
+        if (GET_INT(env, eOpt, &opt))
+            result = esock_getopt_otp(env, descP, opt);
+        else
+            result = esock_make_error(env, esock_atom_einval);
+    } else if (!isEncoded) {
+        result = esock_getopt_native(env, descP, level, eOpt);
+    } else {
+        if (GET_INT(env, eOpt, &opt))
+            result = esock_getopt_level(env, descP, level, opt);
+        else
+            result = esock_make_error(env, esock_atom_einval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* esock_getopt_otp - Handle OTP (level) options
+ */
+static
+ERL_NIF_TERM esock_getopt_otp(ErlNifEnv*       env,
+                              ESockDescriptor* descP,
+                              int              eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_otp -> entry with"
+            "\r\n   eOpt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+    case ESOCK_OPT_OTP_DEBUG:
+        result = esock_getopt_otp_debug(env, descP);
+        break;
+
+    case ESOCK_OPT_OTP_IOW:
+        result = esock_getopt_otp_iow(env, descP);
+        break;
+
+    case ESOCK_OPT_OTP_CTRL_PROC:
+        result = esock_getopt_otp_ctrl_proc(env, descP);
+        break;
+
+    case ESOCK_OPT_OTP_RCVBUF:
+        result = esock_getopt_otp_rcvbuf(env, descP);
+        break;
+
+    case ESOCK_OPT_OTP_RCVCTRLBUF:
+        result = esock_getopt_otp_rcvctrlbuf(env, descP);
+        break;
+
+    case ESOCK_OPT_OTP_SNDCTRLBUF:
+        result = esock_getopt_otp_sndctrlbuf(env, descP);
+        break;
+
+    case ESOCK_OPT_OTP_FD:
+        result = esock_getopt_otp_fd(env, descP);
+        break;
+
+        /* *** INTERNAL *** */
+    case ESOCK_OPT_OTP_DOMAIN:
+        result = esock_getopt_otp_domain(env, descP);
+        break;
+
+    case ESOCK_OPT_OTP_TYPE:
+        result = esock_getopt_otp_type(env, descP);
+        break;
+
+    case ESOCK_OPT_OTP_PROTOCOL:
+        result = esock_getopt_otp_protocol(env, descP);
+        break;
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_otp -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* esock_getopt_otp_debug - Handle the OTP (level) debug option
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_debug(ErlNifEnv*       env,
+                                    ESockDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = esock_encode_bool(descP->dbg);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* esock_getopt_otp_iow - Handle the OTP (level) iow option
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_iow(ErlNifEnv*       env,
+                                  ESockDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = esock_encode_bool(descP->iow);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* esock_getopt_otp_ctrl_proc - Handle the OTP (level) controlling_process option
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_ctrl_proc(ErlNifEnv*       env,
+                                        ESockDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = MKPID(env, &descP->ctrlPid);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+
+/* esock_getopt_otp_rcvbuf - Handle the OTP (level) rcvbuf option
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_rcvbuf(ErlNifEnv*       env,
+                                     ESockDescriptor* descP)
+{
+    ERL_NIF_TERM eVal;
+
+    if (descP->rNum == 0) {
+        eVal = MKI(env, descP->rBufSz);
+    } else {
+        eVal = MKT2(env, MKI(env, descP->rNum), MKI(env, descP->rBufSz));
+    }
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* esock_getopt_otp_rcvctrlbuf - Handle the OTP (level) rcvctrlbuf option
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_rcvctrlbuf(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = MKI(env, descP->rCtrlSz);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* esock_getopt_otp_sndctrlbuf - Handle the OTP (level) sndctrlbuf option
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_sndctrlbuf(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = MKI(env, descP->wCtrlSz);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* esock_getopt_otp_fd - Handle the OTP (level) fd option
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_fd(ErlNifEnv*       env,
+                                 ESockDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = MKI(env, descP->sock);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* esock_getopt_otp_domain - Handle the OTP (level) domain option
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_domain(ErlNifEnv*       env,
+                                     ESockDescriptor* descP)
+{
+    ERL_NIF_TERM result, reason;
+    int          val = descP->domain;
+
+    switch (val) {
+    case AF_INET:
+        result = esock_make_ok2(env, esock_atom_inet);
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case AF_INET6:
+        result = esock_make_ok2(env, esock_atom_inet6);
+        break;
+#endif
+
+#if defined(HAVE_SYS_UN_H)
+    case AF_UNIX:
+        result = esock_make_ok2(env, esock_atom_local);
+        break;
+#endif
+
+    default:
+        reason = MKT2(env, esock_atom_unknown, MKI(env, val));
+        result = esock_make_error(env, reason);
+        break;
+    }
+    
+    return result;
+}
+
+
+/* esock_getopt_otp_type - Handle the OTP (level) type options.
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_type(ErlNifEnv*       env,
+                                   ESockDescriptor* descP)
+{
+    ERL_NIF_TERM result, reason;
+    int          val = descP->type;
+
+    switch (val) {
+    case SOCK_STREAM:
+        result = esock_make_ok2(env, esock_atom_stream);
+        break;
+
+    case SOCK_DGRAM:
+        result = esock_make_ok2(env, esock_atom_dgram);
+        break;
+
+#ifdef HAVE_SCTP
+    case SOCK_SEQPACKET:
+        result = esock_make_ok2(env, esock_atom_seqpacket);
+        break;
+#endif
+    case SOCK_RAW:
+        result = esock_make_ok2(env, esock_atom_raw);
+        break;
+
+    case SOCK_RDM:
+        result = esock_make_ok2(env, esock_atom_rdm);
+        break;
+
+    default:
+        reason = MKT2(env, esock_atom_unknown, MKI(env, val));
+        result = esock_make_error(env, reason);
+        break;
+    }
+
+    return result;
+}
+
+
+/* esock_getopt_otp_protocol - Handle the OTP (level) protocol options.
+ */
+static
+ERL_NIF_TERM esock_getopt_otp_protocol(ErlNifEnv*       env,
+                                       ESockDescriptor* descP)
+{
+    ERL_NIF_TERM result, reason;
+    int          val = descP->protocol;
+
+        switch (val) {
+        case IPPROTO_IP:
+#if defined(AF_LOCAL)
+            if (descP->domain == AF_LOCAL) {
+                result = esock_make_ok2(env, esock_atom_default);
+            } else {
+                result = esock_make_ok2(env, esock_atom_ip);
+            }
+#else
+            result = esock_make_ok2(env, esock_atom_ip);
+#endif
+            break;
+
+        case IPPROTO_TCP:
+            result = esock_make_ok2(env, esock_atom_tcp);
+            break;
+
+        case IPPROTO_UDP:
+            result = esock_make_ok2(env, esock_atom_udp);
+            break;
+
+#if defined(HAVE_SCTP)
+        case IPPROTO_SCTP:
+            result = esock_make_ok2(env, esock_atom_sctp);
+            break;
+#endif
+
+        default:
+            reason = MKT2(env, esock_atom_unknown, MKI(env, val));
+            result = esock_make_error(env, reason);
+            break;
+    }
+
+    return result;
+}
+
+
+
+/* The option has *not* been encoded. Instead it has been provided
+ * in "native mode" (option is provided as is). In this case it will have the
+ * format: {NativeOpt :: integer(), ValueSize :: non_neg_integer()}
+ */
+static
+ERL_NIF_TERM esock_getopt_native(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 int              level,
+                                 ERL_NIF_TERM     eOpt)
+{
+    ERL_NIF_TERM result = enif_make_badarg(env);
+    int          opt;
+    Uint16       valueType;
+    SOCKOPTLEN_T valueSz;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_native -> entry with"
+            "\r\n   level: %d"
+            "\r\n   eOpt:  %T"
+            "\r\n", level, eOpt) );
+
+    /* <KOLLA>
+     * We should really make it possible to specify more common specific types,
+     * such as integer or boolean (instead of the size)...
+     * </KOLLA>
+     */
+
+    if (decode_native_get_opt(env, eOpt, &opt, &valueType, (int*) &valueSz)) {
+
+        SSDBG( descP,
+               ("SOCKET", "esock_getopt_native -> decoded opt"
+                "\r\n   valueType: %d (%s)"
+                "\r\n   ValueSize: %d"
+                "\r\n", valueType, VT2S(valueType), valueSz) );
+
+        switch (valueType) {
+        case ESOCK_OPT_VALUE_TYPE_UNSPEC:
+            result = esock_getopt_native_unspec(env, descP,
+                                                level, opt, valueSz);
+            break;
+        case ESOCK_OPT_VALUE_TYPE_INT:
+            result = esock_getopt_int_opt(env, descP, level, opt);
+            break;
+        case ESOCK_OPT_VALUE_TYPE_BOOL:
+            result = esock_getopt_bool_opt(env, descP, level, opt);
+            break;
+        default:
+            result = esock_make_error(env, esock_atom_einval);
+            break;
+        }
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_native -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+static
+ERL_NIF_TERM esock_getopt_native_unspec(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        int              level,
+                                        int              opt,
+                                        SOCKOPTLEN_T     valueSz)
+{
+    ERL_NIF_TERM result = esock_make_error(env, esock_atom_einval);
+    int          res;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_native_unspec -> entry with"
+            "\r\n   level:   %d"
+            "\r\n   opt:     %d"
+            "\r\n   valueSz: %d"
+            "\r\n", level, opt, valueSz) );
+
+    if (valueSz == 0) {
+        res = sock_getopt(descP->sock, level, opt, NULL, NULL);
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+    } else {
+        SOCKOPTLEN_T vsz = valueSz;
+        ErlNifBinary val;
+
+        SSDBG( descP, ("SOCKET",
+                       "esock_getopt_native_unspec -> try alloc buffer\r\n") );
+
+        if (ALLOC_BIN(vsz, &val)) {
+            int saveErrno;
+            res = sock_getopt(descP->sock, level, opt, val.data, &vsz);
+            if (res != 0) {
+                saveErrno = sock_errno();
+                
+                result = esock_make_error_errno(env, saveErrno);
+            } else {
+
+                /* Did we use all of the buffer? */
+                if (vsz == val.size) {
+
+                    result = esock_make_ok2(env, MKBIN(env, &val));
+
+                } else {
+
+                    ERL_NIF_TERM tmp;
+
+                    tmp = MKBIN(env, &val);
+                    tmp = MKSBIN(env, tmp, 0, vsz);
+                    
+                    result = esock_make_ok2(env, tmp);
+                }
+            }
+        } else {
+            result = enif_make_badarg(env);
+        }
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_native_unspec -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* esock_getopt_level - A "proper" level (option) has been specified
+ */
+static
+ERL_NIF_TERM esock_getopt_level(ErlNifEnv*       env,
+                                ESockDescriptor* descP,
+                                int              level,
+                                int              eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_level -> entry with"
+            "\r\n   level: %d"
+            "\r\n   eOpt:  %d"
+            "\r\n", level, eOpt) );
+
+    switch (level) {
+    case SOL_SOCKET:
+        result = esock_getopt_lvl_socket(env, descP, eOpt);
+        break;
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        result = esock_getopt_lvl_ip(env, descP, eOpt);
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif
+        result = esock_getopt_lvl_ipv6(env, descP, eOpt);
+        break;
+#endif
+
+    case IPPROTO_TCP:
+        result = esock_getopt_lvl_tcp(env, descP, eOpt);
+        break;
+
+    case IPPROTO_UDP:
+        result = esock_getopt_lvl_udp(env, descP, eOpt);
+        break;
+
+#if defined(HAVE_SCTP)
+    case IPPROTO_SCTP:
+        result = esock_getopt_lvl_sctp(env, descP, eOpt);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_level -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* esock_getopt_lvl_socket - Level *SOCKET* option
+ */
+static
+ERL_NIF_TERM esock_getopt_lvl_socket(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     int              eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_socket -> entry with"
+            "\r\n   eOpt:  %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(SO_ACCEPTCONN)
+    case ESOCK_OPT_SOCK_ACCEPTCONN:
+        result = esock_getopt_lvl_sock_acceptconn(env, descP);
+        break;
+#endif
+
+#if defined(SO_BINDTODEVICE)
+    case ESOCK_OPT_SOCK_BINDTODEVICE:
+        result = esock_getopt_lvl_sock_bindtodevice(env, descP);
+        break;
+#endif
+
+#if defined(SO_BROADCAST)
+    case ESOCK_OPT_SOCK_BROADCAST:
+        result = esock_getopt_lvl_sock_broadcast(env, descP);
+        break;
+#endif
+
+#if defined(SO_DEBUG)
+    case ESOCK_OPT_SOCK_DEBUG:
+        result = esock_getopt_lvl_sock_debug(env, descP);
+        break;
+#endif
+
+#if defined(SO_DOMAIN)
+    case ESOCK_OPT_SOCK_DOMAIN:
+        result = esock_getopt_lvl_sock_domain(env, descP);
+        break;
+#endif
+
+#if defined(SO_DONTROUTE)
+    case ESOCK_OPT_SOCK_DONTROUTE:
+        result = esock_getopt_lvl_sock_dontroute(env, descP);
+        break;
+#endif
+
+#if defined(SO_KEEPALIVE)
+    case ESOCK_OPT_SOCK_KEEPALIVE:
+        result = esock_getopt_lvl_sock_keepalive(env, descP);
+        break;
+#endif
+
+#if defined(SO_LINGER)
+    case ESOCK_OPT_SOCK_LINGER:
+        result = esock_getopt_lvl_sock_linger(env, descP);
+        break;
+#endif
+
+#if defined(SO_OOBINLINE)
+    case ESOCK_OPT_SOCK_OOBINLINE:
+        result = esock_getopt_lvl_sock_oobinline(env, descP);
+        break;
+#endif
+
+#if defined(SO_PEEK_OFF)
+    case ESOCK_OPT_SOCK_PEEK_OFF:
+        result = esock_getopt_lvl_sock_peek_off(env, descP);
+        break;
+#endif
+
+#if defined(SO_PRIORITY)
+    case ESOCK_OPT_SOCK_PRIORITY:
+        result = esock_getopt_lvl_sock_priority(env, descP);
+        break;
+#endif
+
+#if defined(SO_PROTOCOL)
+    case ESOCK_OPT_SOCK_PROTOCOL:
+        result = esock_getopt_lvl_sock_protocol(env, descP);
+        break;
+#endif
+
+#if defined(SO_RCVBUF)
+    case ESOCK_OPT_SOCK_RCVBUF:
+        result = esock_getopt_lvl_sock_rcvbuf(env, descP);
+        break;
+#endif
+
+#if defined(SO_RCVLOWAT)
+    case ESOCK_OPT_SOCK_RCVLOWAT:
+        result = esock_getopt_lvl_sock_rcvlowat(env, descP);
+        break;
+#endif
+
+#if defined(SO_RCVTIMEO)
+    case ESOCK_OPT_SOCK_RCVTIMEO:
+        result = esock_getopt_lvl_sock_rcvtimeo(env, descP);
+        break;
+#endif
+
+#if defined(SO_REUSEADDR)
+    case ESOCK_OPT_SOCK_REUSEADDR:
+        result = esock_getopt_lvl_sock_reuseaddr(env, descP);
+        break;
+#endif
+
+#if defined(SO_REUSEPORT)
+    case ESOCK_OPT_SOCK_REUSEPORT:
+        result = esock_getopt_lvl_sock_reuseport(env, descP);
+        break;
+#endif
+
+#if defined(SO_SNDBUF)
+    case ESOCK_OPT_SOCK_SNDBUF:
+        result = esock_getopt_lvl_sock_sndbuf(env, descP);
+        break;
+#endif
+
+#if defined(SO_SNDLOWAT)
+    case ESOCK_OPT_SOCK_SNDLOWAT:
+        result = esock_getopt_lvl_sock_sndlowat(env, descP);
+        break;
+#endif
+
+#if defined(SO_SNDTIMEO)
+    case ESOCK_OPT_SOCK_SNDTIMEO:
+        result = esock_getopt_lvl_sock_sndtimeo(env, descP);
+        break;
+#endif
+
+#if defined(SO_TIMESTAMP)
+    case ESOCK_OPT_SOCK_TIMESTAMP:
+        result = esock_getopt_lvl_sock_timestamp(env, descP);
+        break;
+#endif
+
+#if defined(SO_TYPE)
+    case ESOCK_OPT_SOCK_TYPE:
+        result = esock_getopt_lvl_sock_type(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_socket -> done when"
+            "\r\n   result:  %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+#if defined(SO_ACCEPTCONN)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_acceptconn(ErlNifEnv*       env,
+                                              ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, SOL_SOCKET, SO_ACCEPTCONN);
+}
+#endif
+
+
+#if defined(SO_BINDTODEVICE)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_bindtodevice(ErlNifEnv*       env,
+                                                ESockDescriptor* descP)
+{
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_sock_bindtodevice -> entry with\r\n") );
+
+    return esock_getopt_str_opt(env, descP,
+                                SOL_SOCKET, SO_BINDTODEVICE, IFNAMSIZ+1);
+}
+#endif
+
+
+#if defined(SO_BROADCAST)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_broadcast(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, SOL_SOCKET, SO_BROADCAST);
+}
+#endif
+
+
+#if defined(SO_DEBUG)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_debug(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, SOL_SOCKET, SO_DEBUG);
+}
+#endif
+
+
+#if defined(SO_DOMAIN)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_domain(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+    ERL_NIF_TERM result, reason;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, SOL_SOCKET, SO_DOMAIN,
+                      &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        switch (val) {
+        case AF_INET:
+            result = esock_make_ok2(env, esock_atom_inet);
+            break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+        case AF_INET6:
+            result = esock_make_ok2(env, esock_atom_inet6);
+            break;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+        case AF_UNIX:
+        result = esock_make_ok2(env, esock_atom_local);
+        break;
+#endif
+
+        default:
+            reason = MKT2(env, esock_atom_unknown, MKI(env, val));
+            result = esock_make_error(env, reason);
+            break;
+        }
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(SO_DONTROUTE)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_dontroute(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, SOL_SOCKET, SO_DONTROUTE);
+}
+#endif
+
+
+#if defined(SO_KEEPALIVE)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_keepalive(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, SOL_SOCKET, SO_KEEPALIVE);
+}
+#endif
+
+
+#if defined(SO_LINGER)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_linger(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+    ERL_NIF_TERM  result;
+    struct linger val;
+    SOCKOPTLEN_T  valSz = sizeof(val);
+    int           res;
+
+    sys_memzero((void *) &val, sizeof(val));
+
+    res = sock_getopt(descP->sock, SOL_SOCKET, SO_LINGER,
+                      &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM lOnOff = ((val.l_onoff) ? atom_true : atom_false);
+        ERL_NIF_TERM lSecs  = MKI(env, val.l_linger);
+        ERL_NIF_TERM linger = MKT2(env, lOnOff, lSecs);
+
+        result = esock_make_ok2(env, linger);
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(SO_OOBINLINE)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_oobinline(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, SOL_SOCKET, SO_OOBINLINE);
+}
+#endif
+
+
+#if defined(SO_PEEK_OFF)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_peek_off(ErlNifEnv*       env,
+                                            ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, SOL_SOCKET, SO_PEEK_OFF);
+}
+#endif
+
+
+#if defined(SO_PRIORITY)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_priority(ErlNifEnv*       env,
+                                            ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, SOL_SOCKET, SO_PRIORITY);
+}
+#endif
+
+
+#if defined(SO_PROTOCOL)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_protocol(ErlNifEnv*       env,
+                                            ESockDescriptor* descP)
+{
+    ERL_NIF_TERM result, reason;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, SOL_SOCKET, SO_PROTOCOL,
+                      &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        switch (val) {
+        case IPPROTO_IP:
+#if defined(AF_LOCAL)
+            if (descP->domain == AF_LOCAL)
+                result = esock_make_ok2(env, esock_atom_default);
+            else
+                result = esock_make_ok2(env, esock_atom_ip);
+#else
+            result = esock_make_ok2(env, esock_atom_ip);
+#endif
+            break;
+
+        case IPPROTO_TCP:
+            result = esock_make_ok2(env, esock_atom_tcp);
+            break;
+
+        case IPPROTO_UDP:
+            result = esock_make_ok2(env, esock_atom_udp);
+            break;
+
+#if defined(HAVE_SCTP)
+        case IPPROTO_SCTP:
+            result = esock_make_ok2(env, esock_atom_sctp);
+            break;
+#endif
+
+        default:
+            reason = MKT2(env, esock_atom_unknown, MKI(env, val));
+            result = esock_make_error(env, reason);
+            break;
+        }
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(SO_RCVBUF)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_rcvbuf(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, SOL_SOCKET, SO_RCVBUF);
+}
+#endif
+
+
+#if defined(SO_RCVLOWAT)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_rcvlowat(ErlNifEnv*       env,
+                                            ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, SOL_SOCKET, SO_RCVLOWAT);
+}
+#endif
+
+
+#if defined(SO_RCVTIMEO)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_rcvtimeo(ErlNifEnv*       env,
+                                            ESockDescriptor* descP)
+{
+    return esock_getopt_timeval_opt(env, descP, SOL_SOCKET, SO_RCVTIMEO);
+}
+#endif
+
+
+#if defined(SO_REUSEADDR)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_reuseaddr(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, SOL_SOCKET, SO_REUSEADDR);
+}
+#endif
+
+
+#if defined(SO_REUSEPORT)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_reuseport(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, SOL_SOCKET, SO_REUSEPORT);
+}
+#endif
+
+
+#if defined(SO_SNDBUF)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_sndbuf(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, SOL_SOCKET, SO_SNDBUF);
+}
+#endif
+
+
+#if defined(SO_SNDLOWAT)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_sndlowat(ErlNifEnv*       env,
+                                            ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, SOL_SOCKET, SO_SNDLOWAT);
+}
+#endif
+
+
+#if defined(SO_SNDTIMEO)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_sndtimeo(ErlNifEnv*       env,
+                                            ESockDescriptor* descP)
+{
+    return esock_getopt_timeval_opt(env, descP, SOL_SOCKET, SO_SNDTIMEO);
+}
+#endif
+
+
+#if defined(SO_TIMESTAMP)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_timestamp(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, SOL_SOCKET, SO_TIMESTAMP);
+}
+#endif
+
+
+#if defined(SO_TYPE)
+static
+ERL_NIF_TERM esock_getopt_lvl_sock_type(ErlNifEnv*       env,
+                                        ESockDescriptor* descP)
+{
+    ERL_NIF_TERM result, reason;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, SOL_SOCKET, SO_TYPE, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        switch (val) {
+        case SOCK_STREAM:
+            result = esock_make_ok2(env, esock_atom_stream);
+            break;
+        case SOCK_DGRAM:
+            result = esock_make_ok2(env, esock_atom_dgram);
+            break;
+#ifdef HAVE_SCTP
+        case SOCK_SEQPACKET:
+            result = esock_make_ok2(env, esock_atom_seqpacket);
+            break;
+#endif
+        case SOCK_RAW:
+            result = esock_make_ok2(env, esock_atom_raw);
+            break;
+        case SOCK_RDM:
+            result = esock_make_ok2(env, esock_atom_rdm);
+            break;
+        default:
+            reason = MKT2(env, esock_atom_unknown, MKI(env, val));
+            result = esock_make_error(env, reason);
+            break;
+        }
+    }
+
+    return result;
+}
+#endif
+
+
+/* esock_getopt_lvl_ip - Level *IP* option(s)
+ */
+static
+ERL_NIF_TERM esock_getopt_lvl_ip(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 int              eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_ip -> entry with"
+            "\r\n   eOpt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(IP_FREEBIND)
+    case ESOCK_OPT_IP_FREEBIND:
+        result = esock_getopt_lvl_ip_freebind(env, descP);
+        break;
+#endif
+
+#if defined(IP_HDRINCL)
+    case ESOCK_OPT_IP_HDRINCL:
+        result = esock_getopt_lvl_ip_hdrincl(env, descP);
+        break;
+#endif
+
+#if defined(IP_MINTTL)
+    case ESOCK_OPT_IP_MINTTL:
+        result = esock_getopt_lvl_ip_minttl(env, descP);
+        break;
+#endif
+
+#if defined(IP_MTU)
+    case ESOCK_OPT_IP_MTU:
+        result = esock_getopt_lvl_ip_mtu(env, descP);
+        break;
+#endif
+
+#if defined(IP_MTU_DISCOVER)
+    case ESOCK_OPT_IP_MTU_DISCOVER:
+        result = esock_getopt_lvl_ip_mtu_discover(env, descP);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_ALL)
+    case ESOCK_OPT_IP_MULTICAST_ALL:
+        result = esock_getopt_lvl_ip_multicast_all(env, descP);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_IF)
+    case ESOCK_OPT_IP_MULTICAST_IF:
+        result = esock_getopt_lvl_ip_multicast_if(env, descP);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_LOOP)
+    case ESOCK_OPT_IP_MULTICAST_LOOP:
+        result = esock_getopt_lvl_ip_multicast_loop(env, descP);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_TTL)
+    case ESOCK_OPT_IP_MULTICAST_TTL:
+        result = esock_getopt_lvl_ip_multicast_ttl(env, descP);
+        break;
+#endif
+
+#if defined(IP_NODEFRAG)
+    case ESOCK_OPT_IP_NODEFRAG:
+        result = esock_getopt_lvl_ip_nodefrag(env, descP);
+        break;
+#endif
+
+#if defined(IP_PKTINFO)
+    case ESOCK_OPT_IP_PKTINFO:
+        result = esock_getopt_lvl_ip_pktinfo(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVDSTADDR)
+    case ESOCK_OPT_IP_RECVDSTADDR:
+        result = esock_getopt_lvl_ip_recvdstaddr(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVERR)
+    case ESOCK_OPT_IP_RECVERR:
+        result = esock_getopt_lvl_ip_recverr(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVIF)
+    case ESOCK_OPT_IP_RECVIF:
+        result = esock_getopt_lvl_ip_recvif(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVOPTS)
+    case ESOCK_OPT_IP_RECVOPTS:
+        result = esock_getopt_lvl_ip_recvopts(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVORIGDSTADDR)
+    case ESOCK_OPT_IP_RECVORIGDSTADDR:
+        result = esock_getopt_lvl_ip_recvorigdstaddr(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVTOS)
+    case ESOCK_OPT_IP_RECVTOS:
+        result = esock_getopt_lvl_ip_recvtos(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVTTL)
+    case ESOCK_OPT_IP_RECVTTL:
+        result = esock_getopt_lvl_ip_recvttl(env, descP);
+        break;
+#endif
+
+#if defined(IP_RETOPTS)
+    case ESOCK_OPT_IP_RETOPTS:
+        result = esock_getopt_lvl_ip_retopts(env, descP);
+        break;
+#endif
+
+#if defined(IP_ROUTER_ALERT)
+    case ESOCK_OPT_IP_ROUTER_ALERT:
+        result = esock_getopt_lvl_ip_router_alert(env, descP);
+        break;
+#endif
+
+#if defined(IP_SENDSRCADDR)
+    case ESOCK_OPT_IP_SENDSRCADDR:
+        result = esock_getopt_lvl_ip_sendsrcaddr(env, descP);
+        break;
+#endif
+
+#if defined(IP_TOS)
+    case ESOCK_OPT_IP_TOS:
+        result = esock_getopt_lvl_ip_tos(env, descP);
+        break;
+#endif
+
+#if defined(IP_TRANSPARENT)
+    case ESOCK_OPT_IP_TRANSPARENT:
+        result = esock_getopt_lvl_ip_transparent(env, descP);
+        break;
+#endif
+
+#if defined(IP_TTL)
+    case ESOCK_OPT_IP_TTL:
+        result = esock_getopt_lvl_ip_ttl(env, descP);
+        break;
+#endif
+
+    default:
+        SSDBG( descP,
+               ("SOCKET", "esock_getopt_lvl_ip -> unknown opt %d\r\n", eOpt) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_ip -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* esock_getopt_lvl_ip_minttl - Level IP MINTTL option
+ */
+#if defined(IP_MINTTL)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_minttl(ErlNifEnv*       env,
+                                        ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IP_MINTTL);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_freebind - Level IP FREEBIND option
+ */
+#if defined(IP_FREEBIND)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_freebind(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_FREEBIND);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_hdrincl - Level IP HDRINCL option
+ */
+#if defined(IP_HDRINCL)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_hdrincl(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_HDRINCL);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_mtu - Level IP MTU option
+ */
+#if defined(IP_MTU)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_mtu(ErlNifEnv*       env,
+                                     ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IP_MTU);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_mtu_discover - Level IP MTU_DISCOVER option
+ */
+#if defined(IP_MTU_DISCOVER)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_mtu_discover(ErlNifEnv*       env,
+                                              ESockDescriptor* descP)
+{
+    ERL_NIF_TERM   result;
+    ERL_NIF_TERM   eMtuDisc;
+    int            mtuDisc;
+    SOCKOPTLEN_T   mtuDiscSz = sizeof(mtuDisc);
+    int            res;
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    res = sock_getopt(descP->sock, level, IP_MTU_DISCOVER,
+                      &mtuDisc, &mtuDiscSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        encode_ip_pmtudisc(env, mtuDisc, &eMtuDisc);
+        result = esock_make_ok2(env, eMtuDisc);
+    }
+
+    return result;
+
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_multicast_all - Level IP MULTICAST_ALL option
+ */
+#if defined(IP_MULTICAST_ALL)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_multicast_all(ErlNifEnv*       env,
+                                               ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_MULTICAST_ALL);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_multicast_if - Level IP MULTICAST_IF option
+ */
+#if defined(IP_MULTICAST_IF)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_multicast_if(ErlNifEnv*       env,
+                                              ESockDescriptor* descP)
+{
+    ERL_NIF_TERM   result;
+    ERL_NIF_TERM   eAddr;
+    struct in_addr ifAddr;
+    SOCKOPTLEN_T   ifAddrSz = sizeof(ifAddr);
+    char*          xres;
+    int            res;
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    res = sock_getopt(descP->sock, level, IP_MULTICAST_IF, &ifAddr, &ifAddrSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        if ((xres = esock_encode_ip4_address(env, &ifAddr, &eAddr)) != NULL) {
+            result = esock_make_error_str(env, xres);
+        } else {
+            result = esock_make_ok2(env, eAddr);
+        }
+    }
+
+    return result;
+
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_multicast_loop - Level IP MULTICAST_LOOP option
+ */
+#if defined(IP_MULTICAST_LOOP)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_multicast_loop(ErlNifEnv*       env,
+                                                ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_MULTICAST_LOOP);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_multicast_ttl - Level IP MULTICAST_TTL option
+ */
+#if defined(IP_MULTICAST_TTL)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_multicast_ttl(ErlNifEnv*       env,
+                                               ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IP_MULTICAST_TTL);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_nodefrag - Level IP NODEFRAG option
+ */
+#if defined(IP_NODEFRAG)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_nodefrag(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_NODEFRAG);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_pktinfo - Level IP PKTINFO option
+ */
+#if defined(IP_PKTINFO)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_pktinfo(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_PKTINFO);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_recvtos - Level IP RECVTOS option
+ */
+#if defined(IP_RECVTOS)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_recvtos(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_RECVTOS);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_recvdstaddr - Level IP RECVDSTADDR option
+ */
+#if defined(IP_RECVDSTADDR)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_recvdstaddr(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_RECVDSTADDR);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_recverr - Level IP RECVERR option
+ */
+#if defined(IP_RECVERR)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_recverr(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_RECVERR);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_recvif - Level IP RECVIF option
+ */
+#if defined(IP_RECVIF)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_recvif(ErlNifEnv*       env,
+                                        ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_RECVIF);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_recvopt - Level IP RECVOPTS option
+ */
+#if defined(IP_RECVOPTS)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_recvopts(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_RECVOPTS);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_recvorigdstaddr - Level IP RECVORIGDSTADDR option
+ */
+#if defined(IP_RECVORIGDSTADDR)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_recvorigdstaddr(ErlNifEnv*       env,
+                                                 ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_RECVORIGDSTADDR);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_recvttl - Level IP RECVTTL option
+ */
+#if defined(IP_RECVTTL)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_recvttl(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_RECVTTL);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_retopts - Level IP RETOPTS option
+ */
+#if defined(IP_RETOPTS)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_retopts(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_RETOPTS);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_router_alert - Level IP ROUTER_ALERT option
+ */
+#if defined(IP_ROUTER_ALERT)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_router_alert(ErlNifEnv*       env,
+                                              ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IP_ROUTER_ALERT);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_sendsrcaddr - Level IP SENDSRCADDR option
+ */
+#if defined(IP_SENDSRCADDR)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_sendsrcaddr(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_SENDSRCADDR);
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_tos - Level IP TOS option
+ */
+#if defined(IP_TOS)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_tos(ErlNifEnv*       env,
+                                     ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int          level = SOL_IP;
+#else
+    int          level = IPPROTO_IP;
+#endif
+    ERL_NIF_TERM result;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, level, IP_TOS, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        result = encode_ip_tos(env, val);
+    }
+
+    return result;
+}
+#endif
+
+
+/* esock_getopt_lvl_ip_transparent - Level IP TRANSPARENT option
+ */
+#if defined(IP_TRANSPARENT)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_transparent(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IP_TRANSPARENT);
+}
+#endif
+
+
+
+/* esock_getopt_lvl_ip_ttl - Level IP TTL option
+ */
+#if defined(IP_TTL)
+static
+ERL_NIF_TERM esock_getopt_lvl_ip_ttl(ErlNifEnv*       env,
+                                     ESockDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IP_TTL);
+}
+#endif
+
+
+
+/* esock_getopt_lvl_ipv6 - Level *IPv6* option(s)
+ */
+#if defined(HAVE_IPV6)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   int              eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_ipv6 -> entry with"
+            "\r\n   eOpt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(IPV6_AUTHHDR)
+    case ESOCK_OPT_IPV6_AUTHHDR:
+        result = esock_getopt_lvl_ipv6_authhdr(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_DSTOPTS)
+    case ESOCK_OPT_IPV6_DSTOPTS:
+        result = esock_getopt_lvl_ipv6_dstopts(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_FLOWINFO)
+    case ESOCK_OPT_IPV6_FLOWINFO:
+        result = esock_getopt_lvl_ipv6_flowinfo(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_HOPLIMIT)
+    case ESOCK_OPT_IPV6_HOPLIMIT:
+        result = esock_getopt_lvl_ipv6_hoplimit(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_HOPOPTS)
+    case ESOCK_OPT_IPV6_HOPOPTS:
+        result = esock_getopt_lvl_ipv6_hopopts(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MTU)
+    case ESOCK_OPT_IPV6_MTU:
+        result = esock_getopt_lvl_ipv6_mtu(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MTU_DISCOVER)
+    case ESOCK_OPT_IPV6_MTU_DISCOVER:
+        result = esock_getopt_lvl_ipv6_mtu_discover(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_HOPS)
+    case ESOCK_OPT_IPV6_MULTICAST_HOPS:
+        result = esock_getopt_lvl_ipv6_multicast_hops(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_IF)
+    case ESOCK_OPT_IPV6_MULTICAST_IF:
+        result = esock_getopt_lvl_ipv6_multicast_if(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_LOOP)
+    case ESOCK_OPT_IPV6_MULTICAST_LOOP:
+        result = esock_getopt_lvl_ipv6_multicast_loop(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_RECVERR)
+    case ESOCK_OPT_IPV6_RECVERR:
+        result = esock_getopt_lvl_ipv6_recverr(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+    case ESOCK_OPT_IPV6_RECVPKTINFO:
+        result = esock_getopt_lvl_ipv6_recvpktinfo(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_ROUTER_ALERT)
+    case ESOCK_OPT_IPV6_ROUTER_ALERT:
+        result = esock_getopt_lvl_ipv6_router_alert(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_RTHDR)
+    case ESOCK_OPT_IPV6_RTHDR:
+        result = esock_getopt_lvl_ipv6_rthdr(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_UNICAST_HOPS)
+    case ESOCK_OPT_IPV6_UNICAST_HOPS:
+        result = esock_getopt_lvl_ipv6_unicast_hops(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_V6ONLY)
+    case ESOCK_OPT_IPV6_V6ONLY:
+        result = esock_getopt_lvl_ipv6_v6only(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_ipv6 -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+#if defined(IPV6_AUTHHDR)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_authhdr(ErlNifEnv*       env,
+                                           ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, SOL_IPV6, IPV6_AUTHHDR);
+}
+#endif
+
+
+#if defined(IPV6_DSTOPTS)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_dstopts(ErlNifEnv*       env,
+                                           ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+    return esock_getopt_bool_opt(env, descP, level, IPV6_DSTOPTS);
+}
+#endif
+
+
+#if defined(IPV6_FLOWINFO)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_flowinfo(ErlNifEnv*       env,
+                                            ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IPV6_FLOWINFO);
+}
+#endif
+
+
+#if defined(IPV6_HOPLIMIT)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_hoplimit(ErlNifEnv*       env,
+                                            ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IPV6_HOPLIMIT);
+}
+#endif
+
+
+#if defined(IPV6_HOPOPTS)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_hopopts(ErlNifEnv*       env,
+                                           ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IPV6_HOPOPTS);
+}
+#endif
+
+
+#if defined(IPV6_MTU)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_mtu(ErlNifEnv*       env,
+                                       ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IPV6_MTU);
+}
+#endif
+
+
+/* esock_getopt_lvl_ipv6_mtu_discover - Level IPv6 MTU_DISCOVER option
+ */
+#if defined(IPV6_MTU_DISCOVER)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_mtu_discover(ErlNifEnv*       env,
+                                                ESockDescriptor* descP)
+{
+    ERL_NIF_TERM  result;
+    ERL_NIF_TERM  eMtuDisc;
+    int           mtuDisc;
+    SOCKOPTLEN_T  mtuDiscSz = sizeof(mtuDisc);
+    int           res;
+#if defined(SOL_IPV6)
+    int           level = SOL_IPV6;
+#else
+    int           level = IPPROTO_IPV6;
+#endif
+
+    res = sock_getopt(descP->sock, level, IPV6_MTU_DISCOVER,
+                      &mtuDisc, &mtuDiscSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        encode_ipv6_pmtudisc(env, mtuDisc, &eMtuDisc);
+        result = esock_make_ok2(env, eMtuDisc);
+    }
+
+    return result;
+
+}
+#endif
+
+
+#if defined(IPV6_MULTICAST_HOPS)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_multicast_hops(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IPV6_MULTICAST_HOPS);
+}
+#endif
+
+
+#if defined(IPV6_MULTICAST_IF)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_multicast_if(ErlNifEnv*       env,
+                                                ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IPV6_MULTICAST_IF);
+}
+#endif
+
+
+#if defined(IPV6_MULTICAST_LOOP)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_multicast_loop(ErlNifEnv*       env,
+                                                  ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IPV6_MULTICAST_LOOP);
+}
+#endif
+
+
+#if defined(IPV6_RECVERR)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_recverr(ErlNifEnv*       env,
+                                           ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IPV6_RECVERR);
+}
+#endif
+
+
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_recvpktinfo(ErlNifEnv*       env,
+                                               ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+#if defined(IPV6_RECVPKTINFO)
+    int opt   = IPV6_RECVPKTINFO;
+#else
+    int opt   = IPV6_PKTINFO;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, opt);
+}
+#endif
+
+
+#if defined(IPV6_ROUTER_ALERT)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_router_alert(ErlNifEnv*       env,
+                                                ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IPV6_ROUTER_ALERT);
+}
+#endif
+
+
+#if defined(IPV6_RTHDR)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_rthdr(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IPV6_RTHDR);
+}
+#endif
+
+
+#if defined(IPV6_UNICAST_HOPS)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_unicast_hops(ErlNifEnv*       env,
+                                                ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_int_opt(env, descP, level, IPV6_UNICAST_HOPS);
+}
+#endif
+
+
+#if defined(IPV6_V6ONLY)
+static
+ERL_NIF_TERM esock_getopt_lvl_ipv6_v6only(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return esock_getopt_bool_opt(env, descP, level, IPV6_V6ONLY);
+}
+#endif
+
+
+#endif // defined(HAVE_IPV6)
+
+
+
+/* esock_getopt_lvl_tcp - Level *TCP* option(s)
+ */
+static
+ERL_NIF_TERM esock_getopt_lvl_tcp(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              eOpt)
+{
+    ERL_NIF_TERM result;
+
+    switch (eOpt) {
+#if defined(TCP_CONGESTION)
+    case ESOCK_OPT_TCP_CONGESTION:
+        result = esock_getopt_lvl_tcp_congestion(env, descP);
+        break;
+#endif
+
+#if defined(TCP_MAXSEG)
+    case ESOCK_OPT_TCP_MAXSEG:
+        result = esock_getopt_lvl_tcp_maxseg(env, descP);
+        break;
+#endif
+
+#if defined(TCP_NODELAY)
+    case ESOCK_OPT_TCP_NODELAY:
+        result = esock_getopt_lvl_tcp_nodelay(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* esock_getopt_lvl_tcp_congestion - Level TCP CONGESTION option
+ */
+#if defined(TCP_CONGESTION)
+static
+ERL_NIF_TERM esock_getopt_lvl_tcp_congestion(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    int max = ESOCK_OPT_TCP_CONGESTION_NAME_MAX+1;
+
+    return esock_getopt_str_opt(env, descP, IPPROTO_TCP, TCP_CONGESTION, max);
+}
+#endif
+
+
+/* esock_getopt_lvl_tcp_maxseg - Level TCP MAXSEG option
+ */
+#if defined(TCP_MAXSEG)
+static
+ERL_NIF_TERM esock_getopt_lvl_tcp_maxseg(ErlNifEnv*       env,
+                                         ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, IPPROTO_TCP, TCP_MAXSEG);
+}
+#endif
+
+
+/* esock_getopt_lvl_tcp_nodelay - Level TCP NODELAY option
+ */
+#if defined(TCP_NODELAY)
+static
+ERL_NIF_TERM esock_getopt_lvl_tcp_nodelay(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, IPPROTO_TCP, TCP_NODELAY);
+}
+#endif
+
+
+
+/* esock_getopt_lvl_udp - Level *UDP* option(s)
+ */
+static
+ERL_NIF_TERM esock_getopt_lvl_udp(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              eOpt)
+{
+    ERL_NIF_TERM result;
+
+    switch (eOpt) {
+#if defined(UDP_CORK)
+    case ESOCK_OPT_UDP_CORK:
+        result = esock_getopt_lvl_udp_cork(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* esock_getopt_lvl_udp_cork - Level UDP CORK option
+ */
+#if defined(UDP_CORK)
+static
+ERL_NIF_TERM esock_getopt_lvl_udp_cork(ErlNifEnv*       env,
+                                       ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, IPPROTO_UDP, UDP_CORK);
+}
+#endif
+
+
+
+/* esock_getopt_lvl_sctp - Level *SCTP* option(s)
+ */
+#if defined(HAVE_SCTP)
+static
+ERL_NIF_TERM esock_getopt_lvl_sctp(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   int              eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_sctp -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(SCTP_ASSOCINFO)
+    case ESOCK_OPT_SCTP_ASSOCINFO:
+        result = esock_getopt_lvl_sctp_associnfo(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_AUTOCLOSE)
+    case ESOCK_OPT_SCTP_AUTOCLOSE:
+        result = esock_getopt_lvl_sctp_autoclose(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_DISABLE_FRAGMENTS)
+    case ESOCK_OPT_SCTP_DISABLE_FRAGMENTS:
+        result = esock_getopt_lvl_sctp_disable_fragments(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_INITMSG)
+    case ESOCK_OPT_SCTP_INITMSG:
+        result = esock_getopt_lvl_sctp_initmsg(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_MAXSEG)
+    case ESOCK_OPT_SCTP_MAXSEG:
+        result = esock_getopt_lvl_sctp_maxseg(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_NODELAY)
+    case ESOCK_OPT_SCTP_NODELAY:
+        result = esock_getopt_lvl_sctp_nodelay(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_RTOINFO)
+    case ESOCK_OPT_SCTP_RTOINFO:
+        result = esock_getopt_lvl_sctp_rtoinfo(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_sctp -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* esock_getopt_lvl_sctp_associnfo - Level SCTP ASSOCINFO option
+ *
+ * <KOLLA>
+ *
+ * We should really specify which association this relates to,
+ * as it is now we get assoc-id = 0. If this socket is an 
+ * association (and not an endpoint) then it will have an
+ * assoc id. But since the sctp support at present is "limited",
+ * we leave it for now.
+ * What do we do if this is an endpoint? Invalid op?
+ *
+ * </KOLLA>
+ */
+#if defined(SCTP_ASSOCINFO)
+static
+ERL_NIF_TERM esock_getopt_lvl_sctp_associnfo(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    ERL_NIF_TERM            result;
+    struct sctp_assocparams val;
+    SOCKOPTLEN_T            valSz = sizeof(val);
+    int                     res;
+
+    SSDBG( descP, ("SOCKET", "esock_getopt_lvl_sctp_associnfo -> entry\r\n") );
+    
+    sys_memzero((char*) &val, valSz);
+    res = sock_getopt(descP->sock, IPPROTO_SCTP, SCTP_ASSOCINFO, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM eAssocParams;
+        ERL_NIF_TERM keys[]  = {atom_assoc_id, atom_max_rxt, atom_num_peer_dests,
+                                atom_peer_rwnd, atom_local_rwnd, atom_cookie_life};
+        ERL_NIF_TERM vals[]  = {MKUI(env, val.sasoc_assoc_id),
+                                MKUI(env, val.sasoc_asocmaxrxt),
+                                MKUI(env, val.sasoc_number_peer_destinations),
+                                MKUI(env, val.sasoc_peer_rwnd),
+                                MKUI(env, val.sasoc_local_rwnd),
+                                MKUI(env, val.sasoc_cookie_life)};
+        unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+        unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+        ESOCK_ASSERT( (numKeys == numVals) );
+
+        if (!MKMA(env, keys, vals, numKeys, &eAssocParams))
+            return esock_make_error(env, esock_atom_einval);;
+    
+        result = esock_make_ok2(env, eAssocParams);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_sctp_associnfo -> done with"
+            "\r\n   res:    %d"
+            "\r\n   result: %T"
+            "\r\n", res, result) );
+
+    return result;
+}
+#endif
+
+
+/* esock_getopt_lvl_sctp_autoclose - Level SCTP AUTOCLOSE option
+ */
+#if defined(SCTP_AUTOCLOSE)
+static
+ERL_NIF_TERM esock_getopt_lvl_sctp_autoclose(ErlNifEnv*       env,
+                                             ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, IPPROTO_SCTP, SCTP_AUTOCLOSE);
+}
+#endif
+
+
+/* esock_getopt_lvl_sctp_disable_fragments - Level SCTP DISABLE:FRAGMENTS option
+ */
+#if defined(SCTP_DISABLE_FRAGMENTS)
+static
+ERL_NIF_TERM esock_getopt_lvl_sctp_disable_fragments(ErlNifEnv*       env,
+                                                     ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP,
+                                 IPPROTO_SCTP, SCTP_DISABLE_FRAGMENTS);
+}
+#endif
+
+
+/* esock_getopt_lvl_sctp_initmsg - Level SCTP INITMSG option
+ *
+ */
+#if defined(SCTP_INITMSG)
+static
+ERL_NIF_TERM esock_getopt_lvl_sctp_initmsg(ErlNifEnv*       env,
+                                           ESockDescriptor* descP)
+{
+    ERL_NIF_TERM        result;
+    struct sctp_initmsg val;
+    SOCKOPTLEN_T        valSz = sizeof(val);
+    int                 res;
+
+    SSDBG( descP, ("SOCKET", "esock_getopt_lvl_sctp_initmsg -> entry\r\n") );
+    
+    sys_memzero((char*) &val, valSz);
+    res = sock_getopt(descP->sock, IPPROTO_SCTP, SCTP_INITMSG, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM eInitMsg;
+        ERL_NIF_TERM keys[]  = {atom_num_outstreams, atom_max_instreams,
+                                atom_max_attempts, atom_max_init_timeo};
+        ERL_NIF_TERM vals[]  = {MKUI(env, val.sinit_num_ostreams),
+                                MKUI(env, val.sinit_max_instreams),
+                                MKUI(env, val.sinit_max_attempts),
+                                MKUI(env, val.sinit_max_init_timeo)};
+        unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+        unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+        ESOCK_ASSERT( (numKeys == numVals) );
+
+        if (!MKMA(env, keys, vals, numKeys, &eInitMsg))
+            return esock_make_error(env, esock_atom_einval);;
+    
+        result = esock_make_ok2(env, eInitMsg);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_sctp_initmsg -> done with"
+            "\r\n   res:    %d"
+            "\r\n   result: %T"
+            "\r\n", res, result) );
+
+    return result;
+}
+#endif
+
+
+/* esock_getopt_lvl_sctp_maxseg - Level SCTP MAXSEG option
+ */
+#if defined(SCTP_MAXSEG)
+static
+ERL_NIF_TERM esock_getopt_lvl_sctp_maxseg(ErlNifEnv*       env,
+                                          ESockDescriptor* descP)
+{
+    return esock_getopt_int_opt(env, descP, IPPROTO_SCTP, SCTP_MAXSEG);
+}
+#endif
+
+
+/* esock_getopt_lvl_sctp_nodelay - Level SCTP NODELAY option
+ */
+#if defined(SCTP_NODELAY)
+static
+ERL_NIF_TERM esock_getopt_lvl_sctp_nodelay(ErlNifEnv*       env,
+                                           ESockDescriptor* descP)
+{
+    return esock_getopt_bool_opt(env, descP, IPPROTO_SCTP, SCTP_NODELAY);
+}
+#endif
+
+
+/* esock_getopt_lvl_sctp_associnfo - Level SCTP ASSOCINFO option
+ *
+ * <KOLLA>
+ *
+ * We should really specify which association this relates to,
+ * as it is now we get assoc-id = 0. If this socket is an 
+ * association (and not an endpoint) then it will have an
+ * assoc id (we can assume). But since the sctp support at 
+ * present is "limited", we leave it for now.
+ * What do we do if this is an endpoint? Invalid op?
+ *
+ * </KOLLA>
+ */
+#if defined(SCTP_RTOINFO)
+static
+ERL_NIF_TERM esock_getopt_lvl_sctp_rtoinfo(ErlNifEnv*       env,
+                                           ESockDescriptor* descP)
+{
+    ERL_NIF_TERM        result;
+    struct sctp_rtoinfo val;
+    SOCKOPTLEN_T        valSz = sizeof(val);
+    int                 res;
+
+    SSDBG( descP, ("SOCKET", "esock_getopt_lvl_sctp_rtoinfo -> entry\r\n") );
+    
+    sys_memzero((char*) &val, valSz);
+    res = sock_getopt(descP->sock, IPPROTO_SCTP, SCTP_RTOINFO, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM eRTOInfo;        
+        ERL_NIF_TERM keys[]  = {atom_assoc_id, atom_initial, atom_max, atom_min};
+        ERL_NIF_TERM vals[]  = {MKUI(env, val.srto_assoc_id),
+                                MKUI(env, val.srto_initial),
+                                MKUI(env, val.srto_max),
+                                MKUI(env, val.srto_min)};
+        unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+        unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+        ESOCK_ASSERT( (numKeys == numVals) );
+
+        if (!MKMA(env, keys, vals, numKeys, &eRTOInfo))
+            return esock_make_error(env, esock_atom_einval);;
+    
+        result = esock_make_ok2(env, eRTOInfo);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_lvl_sctp_rtoinfo -> done with"
+            "\r\n   res:    %d"
+            "\r\n   result: %T"
+            "\r\n", res, result) );
+
+    return result;
+}
+#endif
+
+
+
+#endif // defined(HAVE_SCTP)
+
+
+
+/* esock_getopt_bool_opt - get an (integer) bool option
+ */
+static
+ERL_NIF_TERM esock_getopt_bool_opt(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   int              level,
+                                   int              opt)
+{
+    ERL_NIF_TERM result;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    /*
+    SSDBG( descP, ("SOCKET", "esock_getopt_bool_opt -> entry with"
+                   "\r\n: level: %d"
+                   "\r\n: opt:   %d"
+                   "\r\n", level, opt) );
+    */
+
+    res = sock_getopt(descP->sock, level, opt, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM bval = ((val) ? atom_true : atom_false);
+
+        result = esock_make_ok2(env, bval);
+    }
+
+    /*
+    SSDBG( descP, ("SOCKET", "esock_getopt_bool_opt -> done when"
+                   "\r\n: res:    %d"
+                   "\r\n: result: %T"
+                   "\r\n", res, result) );
+    */
+
+    return result;
+}
+
+
+/* esock_getopt_int_opt - get an integer option
+ */
+static
+ERL_NIF_TERM esock_getopt_int_opt(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              level,
+                                  int              opt)
+{
+    ERL_NIF_TERM result;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, level, opt, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        result = esock_make_ok2(env, MKI(env, val));
+    }
+
+    return result;
+}
+
+
+
+/* esock_getopt_timeval_opt - get an timeval option
+ */
+static
+ERL_NIF_TERM esock_getopt_timeval_opt(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      int              level,
+                                      int              opt)
+{
+    ERL_NIF_TERM   result;
+    struct timeval val;
+    SOCKOPTLEN_T   valSz = sizeof(val);
+    int            res;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_timeval_opt -> entry with"
+            "\r\n   level: %d"
+            "\r\n   opt:   %d"
+            "\r\n", level, opt) );
+
+    sys_memzero((char*) &val, valSz);
+    res = sock_getopt(descP->sock, level, opt, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM eTimeVal;
+        char*        xres;
+
+        if ((xres = esock_encode_timeval(env, &val, &eTimeVal)) != NULL)
+            result = esock_make_error_str(env, xres);
+        else
+            result = esock_make_ok2(env, eTimeVal);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_timeval_opt -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* esock_getopt_str_opt - get an string option
+ *
+ * We provide the max size of the string. This is the
+ * size of the buffer we allocate for the value.
+ * The actual size of the (read) value will be communicated
+ * in the optSz variable.
+ */
+#if defined(USE_GETOPT_STR_OPT)
+static
+ERL_NIF_TERM esock_getopt_str_opt(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              level,
+                                  int              opt,
+                                  int              max)
+{
+    ERL_NIF_TERM result;
+    char*        val   = MALLOC(max);
+    SOCKOPTLEN_T valSz = max;
+    int          res;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_str_opt -> entry with"
+            "\r\n   level: %d"
+            "\r\n   opt:   %d"
+            "\r\n   max:   %d"
+            "\r\n", level, opt, max) );
+
+    res = sock_getopt(descP->sock, level, opt, val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM sval = MKSL(env, val, valSz);
+
+        result = esock_make_ok2(env, sval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "esock_getopt_str_opt -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    FREE(val);
+
+    return result;
+}
+#endif // if defined(USE_GETOPT_STR_OPT)
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_sockname - get socket name
+ *
+ * Description:
+ * Returns the current address to which the socket is bound.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+
+static
+ERL_NIF_TERM nif_sockname(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     res;
+
+    SGDBG( ("SOCKET", "nif_sockname -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_sockname -> args when sock = %d:"
+            "\r\n   Socket: %T"
+            "\r\n", descP->sock, argv[0]) );
+
+    res = esock_sockname(env, descP);
+
+    SSDBG( descP, ("SOCKET", "nif_sockname -> done with res = %T\r\n", res) );
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_sockname(ErlNifEnv*       env,
+                            ESockDescriptor* descP)
+{
+    ESockAddress  sa;
+    ESockAddress* saP = &sa;
+    unsigned int  sz  = sizeof(ESockAddress);
+
+    sys_memzero((char*) saP, sz);
+    if (IS_SOCKET_ERROR(sock_name(descP->sock, (struct sockaddr*) saP, &sz))) {
+        return esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM esa;
+        char*        xres;
+
+        if ((xres = esock_encode_sockaddr(env, saP, sz, &esa)) != NULL)
+            return esock_make_error_str(env, xres);
+        else
+            return esock_make_ok2(env, esa);
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_peername - get name of the connected peer socket
+ *
+ * Description:
+ * Returns the address of the peer connected to the socket.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+
+static
+ERL_NIF_TERM nif_peername(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     res;
+
+    SGDBG( ("SOCKET", "nif_peername -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !ESOCK_GET_RESOURCE(env, argv[0], (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_peername -> args when sock = %d:"
+            "\r\n   Socket: %T"
+            "\r\n", descP->sock, argv[0]) );
+
+    res = esock_peername(env, descP);
+
+    SSDBG( descP, ("SOCKET", "nif_peername -> done with res = %T\r\n", res) );
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_peername(ErlNifEnv*       env,
+                            ESockDescriptor* descP)
+{
+    ESockAddress  sa;
+    ESockAddress* saP = &sa;
+    unsigned int  sz  = sizeof(ESockAddress);
+
+    sys_memzero((char*) saP, sz);
+    if (IS_SOCKET_ERROR(sock_peer(descP->sock, (struct sockaddr*) saP, &sz))) {
+        return esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM esa;
+        char*        xres;
+
+        if ((xres = esock_encode_sockaddr(env, saP, sz, &esa)) != NULL)
+            return esock_make_error_str(env, xres);
+        else
+            return esock_make_ok2(env, esa);
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_cancel
+ *
+ * Description:
+ * Cancel a previous select!
+ *
+ * Arguments:
+ * Socket    (ref)  - Points to the socket descriptor.
+ * Operation (atom) - What kind of operation (accept, send, ...) is to be cancelled
+ * Ref       (ref)  - Unique id for the operation
+ */
+static
+ERL_NIF_TERM nif_cancel(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "notsup"));
+#else
+    ESockDescriptor* descP;
+    ERL_NIF_TERM     op, sockRef, opRef, result;
+
+    SGDBG( ("SOCKET", "nif_cancel -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    sockRef = argv[0];
+    if ((argc != 3) ||
+        !ESOCK_GET_RESOURCE(env, sockRef, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    op    = argv[1];
+    opRef = argv[2];
+        
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_cancel -> args when sock = %d:"
+            "\r\n   op:    %T"
+            "\r\n   opRef: %T"
+            "\r\n", descP->sock, op, opRef) );
+    
+    result = esock_cancel(env, descP, op, sockRef, opRef);
+
+    SSDBG( descP,
+           ("SOCKET", "nif_cancel -> done with result: "
+           "\r\n   %T"
+           "\r\n", result) );
+
+    return result;
+#endif // if !defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM esock_cancel(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          ERL_NIF_TERM     op,
+                          ERL_NIF_TERM     sockRef,
+                          ERL_NIF_TERM     opRef)
+{
+    /* <KOLLA>
+     *
+     * Do we really need all these variants? Should it not be enough with: 
+     *
+     *     connect | accept | send | recv
+     *
+     * </KOLLA>
+     */
+    if (COMPARE(op, esock_atom_connect) == 0) {
+        return esock_cancel_connect(env, descP, opRef);
+    } else if (COMPARE(op, esock_atom_accept) == 0) {
+        return esock_cancel_accept(env, descP, sockRef, opRef);
+    } else if (COMPARE(op, esock_atom_send) == 0) {
+        return esock_cancel_send(env, descP, sockRef, opRef);
+    } else if (COMPARE(op, esock_atom_sendto) == 0) {
+        return esock_cancel_send(env, descP, sockRef, opRef);
+    } else if (COMPARE(op, esock_atom_sendmsg) == 0) {
+        return esock_cancel_send(env, descP, sockRef, opRef);
+    } else if (COMPARE(op, esock_atom_recv) == 0) {
+        return esock_cancel_recv(env, descP, sockRef, opRef);
+    } else if (COMPARE(op, esock_atom_recvfrom) == 0) {
+        return esock_cancel_recv(env, descP, sockRef, opRef);
+    } else if (COMPARE(op, esock_atom_recvmsg) == 0) {
+        return esock_cancel_recv(env, descP, sockRef, opRef);
+    } else {
+        return esock_make_error(env, esock_atom_einval);
+    }
+}
+
+
+
+/* *** esock_cancel_connect ***
+ *
+ *
+ */
+static
+ERL_NIF_TERM esock_cancel_connect(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  ERL_NIF_TERM     opRef)
+{
+    return esock_cancel_write_select(env, descP, opRef);
+}
+
+
+/* *** esock_cancel_accept ***
+ *
+ * We have two different cases:
+ *   *) Its the current acceptor
+ *      Cancel the select!
+ *      We need to activate one of the waiting acceptors.
+ *   *) Its one of the acceptors ("waiting") in the queue
+ *      Simply remove the acceptor from the queue.
+ *
+ */
+static
+ERL_NIF_TERM esock_cancel_accept(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 ERL_NIF_TERM     sockRef,
+                                 ERL_NIF_TERM     opRef)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_cancel_accept -> entry with"
+            "\r\n   opRef: %T"
+            "\r\n   %s"
+            "\r\n", opRef,
+            ((descP->currentAcceptorP == NULL) ? "without acceptor" : "with acceptor")) );
+
+    MLOCK(descP->accMtx);
+
+    if (descP->currentAcceptorP != NULL) {
+        if (COMPARE(opRef, descP->currentAcceptor.ref) == 0) {
+            res = esock_cancel_accept_current(env, descP, sockRef);
+        } else {
+            res = esock_cancel_accept_waiting(env, descP, opRef);
+        }
+    } else {
+        /* Or badarg? */
+        res =  esock_make_error(env, esock_atom_einval);
+    }
+
+    MUNLOCK(descP->accMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_cancel_accept -> done with result:"
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+}
+
+
+/* The current acceptor process has an ongoing select we first must
+ * cancel. Then we must re-activate the "first" (the first
+ * in the acceptor queue).
+ */
+static
+ERL_NIF_TERM esock_cancel_accept_current(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     sockRef)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP, ("SOCKET", "esock_cancel_accept_current -> entry\r\n") );
+
+    DEMONP("esock_cancel_accept_current -> current acceptor",
+           env, descP, &descP->currentAcceptor.mon);
+    res = esock_cancel_read_select(env, descP, descP->currentAcceptor.ref);
+
+    SSDBG( descP, ("SOCKET",
+                   "esock_cancel_accept_current -> cancel res: %T\r\n", res) );
+
+    if (!activate_next_acceptor(env, descP, sockRef)) {
+
+        SSDBG( descP,
+               ("SOCKET", "esock_cancel_accept_current -> no more writers\r\n") );
+
+        descP->state               = ESOCK_STATE_LISTENING;
+
+        descP->currentAcceptorP    = NULL;
+        descP->currentAcceptor.ref = esock_atom_undefined;
+        enif_set_pid_undefined(&descP->currentAcceptor.pid);
+        esock_monitor_init(&descP->currentAcceptor.mon);
+    }
+
+    SSDBG( descP, ("SOCKET", "esock_cancel_accept_current -> done with result:"
+                   "\r\n   %T"
+                   "\r\n", res) );
+
+    return res;
+}
+
+
+/* These processes have not performed a select, so we can simply
+ * remove them from the acceptor queue.
+ */
+static
+ERL_NIF_TERM esock_cancel_accept_waiting(ErlNifEnv*       env,
+                                         ESockDescriptor* descP,
+                                         ERL_NIF_TERM     opRef)
+{
+    ErlNifPid caller;
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    /* unqueue request from (acceptor) queue */
+
+    if (acceptor_unqueue(env, descP, &caller)) {
+        return esock_atom_ok;
+    } else {
+        /* Race? */
+        return esock_make_error(env, esock_atom_not_found);
+    }
+}
+
+
+
+/* *** esock_cancel_send ***
+ *
+ * Cancel a send operation.
+ * Its either the current writer or one of the waiting writers.
+ */
+static
+ERL_NIF_TERM esock_cancel_send(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               ERL_NIF_TERM     sockRef,
+                               ERL_NIF_TERM     opRef)
+{
+    ERL_NIF_TERM res;
+
+    MLOCK(descP->writeMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_cancel_send -> entry with"
+            "\r\n   opRef: %T"
+            "\r\n   %s"
+            "\r\n", opRef,
+            ((descP->currentWriterP == NULL) ? "without writer" : "with writer")) );
+
+    if (descP->currentWriterP != NULL) {
+        if (COMPARE(opRef, descP->currentWriter.ref) == 0) {
+            res = esock_cancel_send_current(env, descP, sockRef);
+        } else {
+            res = esock_cancel_send_waiting(env, descP, opRef);
+        }
+    } else {
+        /* Or badarg? */
+        res =  esock_make_error(env, esock_atom_einval);
+    }
+
+    MUNLOCK(descP->writeMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_cancel_send -> done with result:"
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+}
+
+
+
+/* The current writer process has an ongoing select we first must
+ * cancel. Then we must re-activate the "first" (the first
+ * in the writer queue).
+ */
+static
+ERL_NIF_TERM esock_cancel_send_current(ErlNifEnv*       env,
+                                       ESockDescriptor* descP,
+                                       ERL_NIF_TERM     sockRef)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP, ("SOCKET", "esock_cancel_send_current -> entry\r\n") );
+
+    DEMONP("esock_cancel_send_current -> current writer",
+           env, descP, &descP->currentWriter.mon);
+    res = esock_cancel_write_select(env, descP, descP->currentWriter.ref);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_cancel_send_current -> cancel res: %T\r\n", res) );
+
+    if (!activate_next_writer(env, descP, sockRef)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_cancel_send_current -> no more writers\r\n") );
+        descP->currentWriterP    = NULL;
+        descP->currentWriter.ref = esock_atom_undefined;
+        enif_set_pid_undefined(&descP->currentWriter.pid);
+        esock_monitor_init(&descP->currentWriter.mon);
+    }
+
+    SSDBG( descP, ("SOCKET", "esock_cancel_send_current -> done with result:"
+                   "\r\n   %T"
+                   "\r\n", res) );
+
+    return res;
+}
+
+
+/* These processes have not performed a select, so we can simply
+ * remove them from the writer queue.
+ */
+static
+ERL_NIF_TERM esock_cancel_send_waiting(ErlNifEnv*       env,
+                                       ESockDescriptor* descP,
+                                       ERL_NIF_TERM     opRef)
+{
+    ErlNifPid caller;
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    /* unqueue request from (writer) queue */
+
+    if (writer_unqueue(env, descP, &caller)) {
+        return esock_atom_ok;
+    } else {
+        /* Race? */
+        return esock_make_error(env, esock_atom_not_found);
+    }
+}
+
+
+
+/* *** esock_cancel_recv ***
+ *
+ * Cancel a read operation.
+ * Its either the current reader or one of the waiting readers.
+ */
+static
+ERL_NIF_TERM esock_cancel_recv(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               ERL_NIF_TERM     sockRef,
+                               ERL_NIF_TERM     opRef)
+{
+    ERL_NIF_TERM res;
+
+    MLOCK(descP->readMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_cancel_recv -> entry with"
+            "\r\n   opRef: %T"
+            "\r\n   %s"
+            "\r\n", opRef,
+            ((descP->currentReaderP == NULL) ? "without reader" : "with reader")) );
+
+    if (descP->currentReaderP != NULL) {
+        if (COMPARE(opRef, descP->currentReader.ref) == 0) {
+            res = esock_cancel_recv_current(env, descP, sockRef);
+        } else {
+            res = esock_cancel_recv_waiting(env, descP, opRef);
+        }
+    } else {
+        /* Or badarg? */
+        res =  esock_make_error(env, esock_atom_einval);
+    }
+
+    MUNLOCK(descP->readMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_cancel_recv -> done with result:"
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+}
+
+
+/* The current reader process has an ongoing select we first must
+ * cancel. Then we must re-activate the "first" (the first
+ * in the reader queue).
+ */
+static
+ERL_NIF_TERM esock_cancel_recv_current(ErlNifEnv*       env,
+                                       ESockDescriptor* descP,
+                                       ERL_NIF_TERM     sockRef)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP, ("SOCKET", "esock_cancel_recv_current -> entry\r\n") );
+
+    DEMONP("esock_cancel_recv_current -> current reader",
+           env, descP, &descP->currentReader.mon);
+    res = esock_cancel_read_select(env, descP, descP->currentReader.ref);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_cancel_recv_current -> cancel res: %T\r\n", res) );
+
+    if (!activate_next_reader(env, descP, sockRef)) {
+        SSDBG( descP,
+               ("SOCKET", "esock_cancel_recv_current -> no more readers\r\n") );
+        descP->currentReaderP    = NULL;
+        descP->currentReader.ref = esock_atom_undefined;
+        enif_set_pid_undefined(&descP->currentReader.pid);
+        esock_monitor_init(&descP->currentReader.mon);
+    }
+
+    SSDBG( descP, ("SOCKET", "esock_cancel_recv_current -> done with result:"
+                   "\r\n   %T"
+                   "\r\n", res) );
+
+    return res;
+}
+
+
+/* These processes have not performed a select, so we can simply
+ * remove them from the reader queue.
+ */
+static
+ERL_NIF_TERM esock_cancel_recv_waiting(ErlNifEnv*       env,
+                                       ESockDescriptor* descP,
+                                       ERL_NIF_TERM     opRef)
+{
+    ErlNifPid caller;
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    /* unqueue request from (reader) queue */
+
+    if (reader_unqueue(env, descP, &caller)) {
+        return esock_atom_ok;
+    } else {
+        /* Race? */
+        return esock_make_error(env, esock_atom_not_found);
+    }
+}
+
+
+
+static
+ERL_NIF_TERM esock_cancel_read_select(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      ERL_NIF_TERM     opRef)
+{
+    return esock_cancel_mode_select(env, descP, opRef,
+                                    ERL_NIF_SELECT_READ,
+                                    ERL_NIF_SELECT_READ_CANCELLED);
+}
+
+
+static
+ERL_NIF_TERM esock_cancel_write_select(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  ERL_NIF_TERM     opRef)
+{
+    return esock_cancel_mode_select(env, descP, opRef,
+                                    ERL_NIF_SELECT_WRITE,
+                                    ERL_NIF_SELECT_WRITE_CANCELLED);
+}
+
+
+static
+ERL_NIF_TERM esock_cancel_mode_select(ErlNifEnv*       env,
+                                      ESockDescriptor* descP,
+                                      ERL_NIF_TERM     opRef,
+                                      int              smode,
+                                      int              rmode)
+{
+    int selectRes = esock_select_cancel(env, descP->sock, smode, descP);
+
+    if (selectRes & rmode) {
+        /* Was cancelled */
+        return esock_atom_ok;
+    } else if (selectRes > 0) {
+        /* Has already sent the message */
+        return esock_make_error(env, esock_atom_select_sent);
+    } else {
+        /* Stopped? */
+        SSDBG( descP, ("SOCKET",
+                       "esock_cancel_mode_select -> failed: %d (0x%lX)"
+                       "\r\n", selectRes, selectRes) );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+}
+#endif // if !defined(__WIN32__)
+
+
+
+
+/* ----------------------------------------------------------------------
+ *  U t i l i t y   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* *** send_check_writer ***
+ *
+ * Checks if we have a current writer and if that is us.
+ * If not (current writer), then we must be made to wait
+ * for our turn. This is done by pushing us unto the writer queue.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T send_check_writer(ErlNifEnv*       env,
+                            ESockDescriptor* descP,
+                            ERL_NIF_TERM     ref,
+                            ERL_NIF_TERM*    checkResult)
+{
+    if (descP->currentWriterP != NULL) {
+        ErlNifPid caller;
+        
+        if (enif_self(env, &caller) == NULL) {
+            *checkResult = esock_make_error(env, atom_exself);
+            return FALSE;
+        }
+
+        if (COMPARE_PIDS(&descP->currentWriter.pid, &caller) != 0) {
+            /* Not the "current writer", so (maybe) push onto queue */
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "send_check_writer -> not (current) writer\r\n") );
+
+            if (!writer_search4pid(env, descP, &caller))
+                *checkResult = writer_push(env, descP, caller, ref);
+            else
+                *checkResult = esock_make_error(env, esock_atom_eagain);
+            
+            SSDBG( descP,
+                   ("SOCKET",
+                    "send_check_writer -> queue (push) result: %T\r\n",
+                    checkResult) );
+            
+            return FALSE;
+
+        }
+        
+    }
+
+    // Does not actually matter in this case, but ...
+    *checkResult = esock_atom_ok;
+
+    return TRUE;
+}
+
+
+
+/* *** send_check_result ***
+ *
+ * Check the result of a socket send (send, sendto and sendmsg) call.
+ * If a "complete" send has been made, the next (waiting) writer will be 
+ * scheduled (if there is one).
+ * If we did not manage to send the entire package, make another select,
+ * so that we can be informed when we can make another try (to send the rest),
+ * and return with the amount we actually managed to send (its up to the caller
+ * (that is the erlang code) to figure out hust much is left to send).
+ * If the write fail, we give up and return with the appropriate error code.
+ *
+ * What about the remaining writers!!
+ *
+ */
+static
+ERL_NIF_TERM send_check_result(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               ssize_t          written,
+                               ssize_t          dataSize,
+                               int              saveErrno,
+                               ERL_NIF_TERM     sockRef,
+                               ERL_NIF_TERM     sendRef)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP,
+           ("SOCKET", "send_check_result -> entry with"
+            "\r\n   written:   %d"
+            "\r\n   dataSize:  %d"
+            "\r\n   saveErrno: %d"
+            "\r\n", written, dataSize, saveErrno) );
+
+    if (written >= dataSize) {
+
+        res = send_check_ok(env, descP, written, dataSize, sockRef);
+
+    } else if (written < 0) {
+
+        /* Some kind of send failure - check what kind */
+
+        if ((saveErrno != EAGAIN) && (saveErrno != EINTR)) {
+
+            res = send_check_fail(env, descP, saveErrno, sockRef);
+
+        } else {
+
+            /* Ok, try again later */
+
+            SSDBG( descP, ("SOCKET", "send_check_result -> try again\r\n") );
+
+            res = send_check_retry(env, descP, written, sockRef, sendRef);
+
+        }
+
+    } else {
+
+        /* Not the entire package */
+
+        SSDBG( descP,
+               ("SOCKET", "send_check_result -> "
+                "not entire package written (%d of %d)\r\n",
+                written, dataSize) );
+
+        res = send_check_retry(env, descP, written, sockRef, sendRef);
+
+    }
+
+    SSDBG( descP, ("SOCKET", "send_check_result -> done: %T\r\n", res) );
+
+    return res;
+}
+
+
+/* *** send_check_ok ***
+ *
+ * Processing done upon successful send.
+ */
+static
+ERL_NIF_TERM send_check_ok(ErlNifEnv*       env,
+                           ESockDescriptor* descP,
+                           ssize_t          written,
+                           ssize_t          dataSize,
+                           ERL_NIF_TERM     sockRef)
+{
+    // cnt_inc(&descP->writePkgCnt,  1);
+    SOCK_CNT_INC(env, descP, sockRef,
+                 atom_write_pkg, &descP->writePkgCnt, 1);
+    // cnt_inc(&descP->writeByteCnt, written);
+    SOCK_CNT_INC(env, descP, sockRef,
+                 atom_write_byte, &descP->writeByteCnt, written);
+
+    if (descP->currentWriterP != NULL) {
+        DEMONP("send_check_ok -> current writer",
+               env, descP, &descP->currentWriter.mon);
+        esock_free_env("send_check_ok", descP->currentWriter.env);
+        descP->currentWriter.env = NULL;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "send_check_ok -> "
+            "everything written (%d,%d) - done\r\n", dataSize, written) );
+
+    /*
+     * Ok, this write is done maybe activate the next (if any)
+     */
+
+    if (!activate_next_writer(env, descP, sockRef)) {
+        descP->currentWriterP    = NULL;
+        ESOCK_ASSERT(!descP->currentWriter.env);
+        descP->currentWriter.env = NULL;
+        descP->currentWriter.ref = esock_atom_undefined;
+        enif_set_pid_undefined(&descP->currentWriter.pid);
+        esock_monitor_init(&descP->currentWriter.mon);
+    }
+
+    return esock_atom_ok;
+}
+
+
+
+/* *** send_check_failure ***
+ *
+ * Processing done upon failed send.
+ * An actual failure - we (and everyone waiting) give up.
+ */
+static
+ERL_NIF_TERM send_check_fail(ErlNifEnv*       env,
+                             ESockDescriptor* descP,
+                             int              saveErrno,
+                             ERL_NIF_TERM     sockRef)
+{
+    ESockRequestor req;
+    ERL_NIF_TERM   reason;
+
+    req.env = NULL;
+    // cnt_inc(&descP->writeFails, 1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_write_fails, &descP->writeFails, 1);
+
+    SSDBG( descP, ("SOCKET", "send_check_fail -> error: %d\r\n", saveErrno) );
+
+    reason = MKA(env, erl_errno_id(saveErrno));
+
+    if (descP->currentWriterP != NULL) {
+
+        DEMONP("send_check_fail -> current writer",
+               env, descP, &descP->currentWriter.mon);
+
+        while (writer_pop(env, descP, &req)) {
+            SSDBG( descP,
+                   ("SOCKET", "send_check_fail -> abort %T\r\n", req.pid) );
+            esock_send_abort_msg(env, sockRef, req.ref, req.env,
+                                 reason, &req.pid);
+            req.env = NULL;
+            DEMONP("send_check_fail -> pop'ed writer", env, descP, &req.mon);
+        }
+    }
+
+    return esock_make_error(env, reason);
+}
+
+
+
+/* *** send_check_retry ***
+ *
+ * Processing done upon uncomplete or blocked send.
+ *
+ * We failed to write the *entire* packet (anything less
+ * then size of the packet, which is 0 <= written < sizeof
+ * packet, so schedule the rest for later.
+ */
+static
+ERL_NIF_TERM send_check_retry(ErlNifEnv*       env,
+                              ESockDescriptor* descP,
+                              ssize_t          written,
+                              ERL_NIF_TERM     sockRef,
+                              ERL_NIF_TERM     sendRef)
+{
+    int          sres;
+    ErlNifPid    caller;
+    ERL_NIF_TERM res;
+
+    if (descP->currentWriterP == NULL) {
+
+        if (enif_self(env, &caller) == NULL)
+            return esock_make_error(env, atom_exself);
+        descP->currentWriter.pid = caller;
+
+        if (MONP("send_check_retry -> current writer",
+                 env, descP,
+                 &descP->currentWriter.pid,
+                 &descP->currentWriter.mon) != 0) {
+            enif_set_pid_undefined(&descP->currentWriter.pid);
+            return esock_make_error(env, atom_exmon);
+        } else {
+            ESOCK_ASSERT(!descP->currentWriter.env);
+            descP->currentWriter.env = esock_alloc_env("current-writer");
+            descP->currentWriter.ref = CP_TERM(descP->currentWriter.env, sendRef);
+            descP->currentWriterP    = &descP->currentWriter;
+        }
+    }
+
+    // cnt_inc(&descP->writeWaits, 1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_write_waits, &descP->writeWaits, 1);
+
+    sres = esock_select_write(env, descP->sock, descP, NULL, sockRef, sendRef);
+
+    if (written >= 0) {
+
+        /* Partial *write* success */
+
+        if (sres < 0) {
+            /* Returned: {error, Reason}
+             * Reason:   {select_failed, sres, written}
+             */
+            res = esock_make_error(env,
+                                   MKT3(env,
+                                        esock_atom_select_failed,
+                                        MKI(env, sres),
+                                        MKI(env, written)));
+        } else {
+            res = esock_make_ok2(env, MKI(env, written));
+        }
+
+    } else {
+
+        if (sres < 0) {
+            /* Returned: {error, Reason}
+             * Reason:   {select_failed, sres}
+             */
+            res = esock_make_error(env,
+                                   MKT2(env,
+                                        esock_atom_select_failed,
+                                        MKI(env, sres)));
+        } else {
+            res = esock_make_error(env, esock_atom_eagain);
+        }
+    }
+
+    return res;
+}
+
+
+
+
+/* *** recv_check_reader ***
+ *
+ * Checks if we have a current reader and if that is us. If not,
+ * then we must be made to wait for our turn. This is done by pushing
+ * us unto the reader queue.
+ * Note that we do *not* actually initiate the currentReader structure
+ * here, since we do not actually know yet if we need to! We do that in
+ * the [recv|recvfrom|recvmsg]_check_result function.
+ */
+static
+BOOLEAN_T recv_check_reader(ErlNifEnv*       env,
+                            ESockDescriptor* descP,
+                            ERL_NIF_TERM     ref,
+                            ERL_NIF_TERM*    checkResult)
+{
+    if (descP->currentReaderP != NULL) {
+        ErlNifPid caller;
+        
+        if (enif_self(env, &caller) == NULL) {
+            *checkResult = esock_make_error(env, atom_exself);
+            return FALSE;
+        }
+
+        if (COMPARE_PIDS(&descP->currentReader.pid, &caller) != 0) {
+            ERL_NIF_TERM tmp;
+
+            /* Not the "current reader", so (maybe) push onto queue */
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recv_check_reader -> not (current) reader\r\n") );
+
+            if (!reader_search4pid(env, descP, &caller))
+                tmp = reader_push(env, descP, caller, ref);
+            else
+                tmp = esock_make_error(env, esock_atom_eagain);
+            
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recv_check_reader -> queue (push) result: %T\r\n", tmp) );
+
+            *checkResult = tmp;
+
+            return FALSE;
+
+        }
+        
+    }
+
+    // Does not actually matter in this case, but ...
+    *checkResult = esock_atom_ok;
+
+    return TRUE;
+}
+
+
+
+/* *** recv_init_current_reader ***
+ *
+ * Initiate (maybe) the currentReader structure of the descriptor.
+ * Including monitoring the calling process.
+ */
+static
+char* recv_init_current_reader(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               ERL_NIF_TERM     recvRef)
+{
+    if (descP->currentReaderP == NULL) {
+        ErlNifPid caller;
+
+        if (enif_self(env, &caller) == NULL)
+            return str_exself;
+
+        descP->currentReader.pid = caller;
+        if (MONP("recv_init_current_reader -> current reader",
+                 env, descP,
+                 &descP->currentReader.pid,
+                 &descP->currentReader.mon) != 0) {
+            enif_set_pid_undefined(&descP->currentReader.pid);
+            return str_exmon;
+        } else {
+            ESOCK_ASSERT(!descP->currentReader.env);
+            descP->currentReader.env = esock_alloc_env("current-reader");
+            descP->currentReader.ref = CP_TERM(descP->currentReader.env,
+                                               recvRef);
+            descP->currentReaderP    = &descP->currentReader;
+        }
+    } else {
+
+        /*
+         * This is a retry:
+         * We have done, for instance, recv(Sock, X), but only received Y < X.
+         * We then call recv again with size = X-Y. So, we then get a new ref.
+         * 
+         * Make use of the existing environment
+         */
+
+        descP->currentReader.ref = CP_TERM(descP->currentReader.env, recvRef);
+    }
+
+    return NULL;
+}
+
+
+
+/* *** recv_update_current_reader ***
+ *
+ * Demonitors the current reader process and pop's the reader queue.
+ * If there is a waiting (reader) process, then it will be assigned
+ * as the new current reader and a new (read) select will be done.
+ */
+
+static
+ERL_NIF_TERM recv_update_current_reader(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        ERL_NIF_TERM     sockRef)
+{
+    ERL_NIF_TERM res = esock_atom_ok;
+
+    if (descP->currentReaderP != NULL) {
+        
+        DEMONP("recv_update_current_reader",
+               env, descP, &descP->currentReader.mon);
+
+        esock_free_env("recv_update_current_reader - current-read-env",
+                       descP->currentReader.env);
+        descP->currentReader.env = NULL;
+
+        if (!activate_next_reader(env, descP, sockRef)) {
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recv_update_current_reader -> no more readers\r\n") );
+
+            descP->currentReaderP    = NULL;
+            descP->currentReader.ref = esock_atom_undefined;
+            enif_set_pid_undefined(&descP->currentReader.pid);
+            esock_monitor_init(&descP->currentReader.mon);
+        }
+
+    }
+
+    return res;
+}
+
+
+
+/* *** recv_error_current_reader ***
+ *
+ * Process the current reader and any waiting readers
+ * when a read (fatal) error has occured.
+ * All waiting readers will be "aborted", that is a 
+ * nif_abort message will be sent (with reaf and reason).
+ */
+static
+void recv_error_current_reader(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               ERL_NIF_TERM     sockRef,
+                               ERL_NIF_TERM     reason)
+{
+    ESockRequestor req;
+
+    req.env = NULL;
+    if (descP->currentReaderP != NULL) {
+
+        DEMONP("recv_error_current_reader -> current reader",
+               env, descP, &descP->currentReader.mon);
+
+        while (reader_pop(env, descP, &req)) {
+            SSDBG( descP,
+                   ("SOCKET", "recv_error_current_reader -> abort %T\r\n",
+                    req.pid) );
+            esock_send_abort_msg(env, sockRef, req.ref, req.env,
+                                 reason, &req.pid);
+            req.env = NULL;
+            DEMONP("recv_error_current_reader -> pop'ed reader",
+                   env, descP, &req.mon);
+        }
+    }
+}
+
+
+
+/* *** recv_check_result ***
+ *
+ * Process the result of a call to recv.
+ */
+static
+ERL_NIF_TERM recv_check_result(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               int              read,
+                               int              toRead,
+                               int              saveErrno,
+                               ErlNifBinary*    bufP,
+                               ERL_NIF_TERM     sockRef,
+                               ERL_NIF_TERM     recvRef)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP,
+           ("SOCKET", "recv_check_result -> entry with"
+            "\r\n   read:      %d"
+            "\r\n   toRead:    %d"
+            "\r\n   saveErrno: %d"
+            "\r\n   recvRef:   %T"
+            "\r\n", read, toRead, saveErrno, recvRef) );
+
+
+    /* <KOLLA>
+     *
+     * We need to handle read = 0 for other type(s) (DGRAM) when
+     * its actually valid to read 0 bytes.
+     *
+     * </KOLLA>
+     */
+    
+    if ((read == 0) && (descP->type == SOCK_STREAM)) {
+
+        res = esock_make_error(env, atom_closed);
+        
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_fails, &descP->readFails, 1);
+
+        /*
+         * When a stream socket peer has performed an orderly shutdown,
+         * the return value will be 0 (the traditional "end-of-file" return).
+         *
+         * *We* do never actually try to read 0 bytes from a stream socket!
+         *
+         * We must also notify any waiting readers!
+         */
+
+        recv_error_current_reader(env, descP, sockRef, res);
+
+        FREE_BIN(bufP);
+
+    } else {
+    
+        /* There is a special case: If the provided 'to read' value is
+         * zero (0) (only for type =/= stream).
+         * That means that we reads as much as we can, using the default
+         * read buffer size.
+         */
+
+        if (bufP->size == read) {
+
+            /* +++ We filled the buffer +++ */
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recv_check_result -> [%d] filled the buffer\r\n",
+                    toRead) );
+
+            res = recv_check_full(env, descP, read, toRead, bufP,
+                                  sockRef, recvRef);
+
+        } else if (read < 0) {
+
+            /* +++ Error handling +++ */
+
+            res = recv_check_fail(env, descP, saveErrno, bufP, NULL,
+                                  sockRef, recvRef);
+
+        } else {
+
+            /* +++ We did not fill the buffer +++ */
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recv_check_result -> [%d] "
+                    "did not fill the buffer (%d of %d)\r\n",
+                    toRead, read, bufP->size) );
+
+            res = recv_check_partial(env, descP, read, toRead, bufP,
+                                     sockRef, recvRef);
+
+        }
+    }
+
+    return res;
+}
+
+
+
+/* *** recv_check_full ***
+ *
+ * This function is called if we filled the allocated buffer.
+ * But are we done yet?
+ *
+ * toRead = 0 means: Give me everything you have => maybe
+ * toRead > 0 means: Yes
+ */
+static
+ERL_NIF_TERM recv_check_full(ErlNifEnv*       env,
+                             ESockDescriptor* descP,
+                             int              read,
+                             int              toRead,
+                             ErlNifBinary*    bufP,
+                             ERL_NIF_TERM     sockRef,
+                             ERL_NIF_TERM     recvRef)
+{
+    ERL_NIF_TERM res;
+
+    if (toRead == 0) {
+
+        /* +++ Give us everything you have got =>     *
+         *     (maybe) needs to continue          +++ */
+
+        /* Send up each chunk of data for each of the read
+         * and let the erlang code assemble it: {ok, false, Bin}
+         * (when complete it should return {ok, true, Bin}).
+         * We need to read atleast one more time to be sure if its
+         * done...
+         *
+         * Also, we need to check if the rNumCnt has reached its max (rNum),
+         * in which case we will assume the read to be done!
+         */
+
+        SSDBG( descP,
+               ("SOCKET", "recv_check_full -> shall we continue reading"
+                "\r\n   read:    %d"
+                "\r\n   rNum:    %d"
+                "\r\n   rNumCnt: %d"
+                "\r\n", read, descP->rNum, descP->rNumCnt) );
+
+        res = recv_check_full_maybe_done(env, descP, read, toRead, bufP,
+                                         sockRef, recvRef);
+
+    } else {
+
+        /* +++ We got exactly as much as we requested => We are done +++ */
+
+        SSDBG( descP,
+               ("SOCKET",
+                "recv_check_full -> [%d] "
+                "we got exactly what we could fit\r\n", toRead) );
+
+        res = recv_check_full_done(env, descP, read, bufP, sockRef);
+
+    }
+
+    return res;
+
+}
+
+
+
+/* *** recv_check_full_maybe_done ***
+ *
+ * Send up each chunk of data for each of the read
+ * and let the erlang code assemble it: {ok, false, Bin}
+ * (when complete it should return {ok, true, Bin}).
+ * We need to read atleast one more time to be sure if its
+ * done...
+ *
+ * Also, we need to check if the rNumCnt has reached its max (rNum),
+ * in which case we will assume the read to be done!
+ */
+static
+ERL_NIF_TERM recv_check_full_maybe_done(ErlNifEnv*       env,
+                                        ESockDescriptor* descP,
+                                        int              read,
+                                        int              toRead,
+                                        ErlNifBinary*    bufP,
+                                        ERL_NIF_TERM     sockRef,
+                                        ERL_NIF_TERM     recvRef)
+{
+    char* xres;
+
+    // cnt_inc(&descP->readByteCnt, read);
+    SOCK_CNT_INC(env, descP, sockRef, atom_read_byte, &descP->readByteCnt, read);
+
+    if (descP->rNum > 0) {
+
+        descP->rNumCnt++;
+        if (descP->rNumCnt >= descP->rNum) {
+
+            descP->rNumCnt = 0;
+
+            // cnt_inc(&descP->readPkgCnt, 1);
+            SOCK_CNT_INC(env, descP, sockRef, atom_read_pkg, &descP->readPkgCnt, 1);
+
+            recv_update_current_reader(env, descP, sockRef);
+
+            /* This transfers "ownership" of the *allocated* binary to an
+             * erlang term (no need for an explicit free).
+             */
+
+            return esock_make_ok3(env, atom_true, MKBIN(env, bufP));
+
+        }
+    }
+
+    /* Yes, we *do* need to continue reading */
+
+    if ((xres = recv_init_current_reader(env, descP, recvRef)) != NULL) {
+        descP->rNumCnt = 0;
+        FREE_BIN(bufP);
+        return esock_make_error_str(env, xres);
+    }
+
+    /* This transfers "ownership" of the *allocated* binary to an
+     * erlang term (no need for an explicit free).
+     */
+
+    SSDBG( descP,
+           ("SOCKET",
+            "recv_check_full_maybe_done -> [%d] "
+            "we are done for now - read more\r\n", toRead) );
+
+    return esock_make_ok3(env, atom_false, MKBIN(env, bufP));
+}
+
+
+
+/* *** recv_check_full_done ***
+ *
+ * A successful recv and we filled the buffer.
+ */
+static
+ERL_NIF_TERM recv_check_full_done(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              read,
+                                  ErlNifBinary*    bufP,
+                                  ERL_NIF_TERM     sockRef)
+{
+    ERL_NIF_TERM data;
+
+    // cnt_inc(&descP->readPkgCnt,  1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_read_pkg, &descP->readPkgCnt, 1);
+    // cnt_inc(&descP->readByteCnt, read);
+    SOCK_CNT_INC(env, descP, sockRef, atom_read_byte, &descP->readByteCnt, read);
+
+    recv_update_current_reader(env, descP, sockRef);
+
+    /* This transfers "ownership" of the *allocated* binary to an
+     * erlang term (no need for an explicit free).
+     */
+    data = MKBIN(env, bufP);
+
+    return esock_make_ok3(env, atom_true, data);
+}
+
+
+
+/* *** recv_check_fail ***
+ *
+ * Handle recv failure.
+ */
+static
+ERL_NIF_TERM recv_check_fail(ErlNifEnv*       env,
+                             ESockDescriptor* descP,
+                             int              saveErrno,
+                             ErlNifBinary*    buf1P,
+                             ErlNifBinary*    buf2P,
+                             ERL_NIF_TERM     sockRef,
+                             ERL_NIF_TERM     recvRef)
+{
+    ERL_NIF_TERM res;
+
+    FREE_BIN(buf1P); if (buf2P != NULL) FREE_BIN(buf2P);
+
+    if (saveErrno == ECONNRESET)  {
+
+        /* +++ Oups - closed +++ */
+
+        SSDBG( descP, ("SOCKET", "recv_check_fail -> closed\r\n") );
+
+        // This is a bit overkill (to count here), but just in case...
+        // cnt_inc(&descP->readFails, 1);
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_fails, &descP->readFails, 1);
+
+        res = recv_check_fail_closed(env, descP, sockRef, recvRef);
+
+    } else if ((saveErrno == ERRNO_BLOCK) ||
+               (saveErrno == EAGAIN)) {
+
+        SSDBG( descP, ("SOCKET", "recv_check_fail -> eagain\r\n") );
+
+        res = recv_check_retry(env, descP, sockRef, recvRef);
+
+    } else {
+
+        SSDBG( descP, ("SOCKET", "recv_check_fail -> errno: %d\r\n",
+                       saveErrno) );
+
+        // cnt_inc(&descP->readFails, 1);
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_fails, &descP->readFails, 1);
+
+        res = recv_check_fail_gen(env, descP, saveErrno, sockRef);
+    }
+
+    return res;
+}
+
+
+
+/* *** recv_check_fail_closed ***
+ *
+ * We detected that the socket was closed wile reading.
+ * Inform current and waiting readers.
+ */
+static
+ERL_NIF_TERM recv_check_fail_closed(ErlNifEnv*       env,
+                                    ESockDescriptor* descP,
+                                    ERL_NIF_TERM     sockRef,
+                                    ERL_NIF_TERM     recvRef)
+{
+    ERL_NIF_TERM res = esock_make_error(env, atom_closed);
+    int          sres;
+
+    /* <KOLLA>
+     *
+     * IF THE CURRENT PROCESS IS *NOT* THE CONTROLLING
+     * PROCESS, WE NEED TO INFORM IT!!!
+     *
+     * ALL WAITING PROCESSES MUST ALSO GET THE ERROR!!
+     * HANDLED BY THE STOP (CALLBACK) FUNCTION?
+     *
+     * SINCE THIS IS A REMOTE CLOSE, WE DON'T NEED TO WAIT
+     * FOR OUTPUT TO BE WRITTEN (NO ONE WILL READ), JUST
+     * ABORT THE SOCKET REGARDLESS OF LINGER???
+     *
+     * </KOLLA>
+     */
+
+    descP->closeLocal = FALSE;
+    descP->state      = ESOCK_STATE_CLOSING;
+
+    recv_error_current_reader(env, descP, sockRef, res);
+
+    if ((sres = esock_select_stop(env, descP->sock, descP)) < 0) {
+        esock_warning_msg("Failed stop select (closed) "
+                          "for current reader (%T): %d\r\n",
+                          recvRef, sres);
+    }
+
+    return res;
+}
+
+
+
+/* *** recv_check_retry ***
+ *
+ * The recv call would have blocked, so retry.
+ */
+static
+ERL_NIF_TERM recv_check_retry(ErlNifEnv*       env,
+                              ESockDescriptor* descP,
+                              ERL_NIF_TERM     sockRef,
+                              ERL_NIF_TERM     recvRef)
+{
+    int          sres;
+    char*        xres;
+    ERL_NIF_TERM reason;
+
+    descP->rNumCnt = 0;
+    if ((xres = recv_init_current_reader(env, descP, recvRef)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    SSDBG( descP, ("SOCKET", "recv_check_retry -> SELECT for more\r\n") );
+
+    if ((sres = esock_select_read(env, descP->sock, descP, NULL,
+                                  sockRef, recvRef)) < 0) {
+        /* Ouch
+         * Now what? We have copied ref into *its own* environment!
+         */
+        reason = MKT2(env, esock_atom_select_failed, MKI(env, sres));
+    } else {
+        reason = esock_atom_eagain;
+    }
+
+    return esock_make_error(env, reason);
+
+}
+
+
+
+/* *** recv_check_fail_gen ***
+ *
+ * The recv call had a "general" failure.
+ */
+static
+ERL_NIF_TERM recv_check_fail_gen(ErlNifEnv*       env,
+                                 ESockDescriptor* descP,
+                                 int              saveErrno,
+                                 ERL_NIF_TERM     sockRef)
+{
+    ERL_NIF_TERM res = esock_make_error_errno(env, saveErrno);
+
+    recv_error_current_reader(env, descP, sockRef, res);
+
+    return res;
+}
+
+
+
+/* *** recv_check_partial ***
+ *
+ * Handle a sucessful recv which only partly filled the specified buffer.
+ */
+static
+ERL_NIF_TERM recv_check_partial(ErlNifEnv*       env,
+                                ESockDescriptor* descP,
+                                int              read,
+                                int              toRead,
+                                ErlNifBinary*    bufP,
+                                ERL_NIF_TERM     sockRef,
+                                ERL_NIF_TERM     recvRef)
+{
+    ERL_NIF_TERM res;
+
+    if (toRead == 0) {
+
+        /* +++ We got it all, but since we      +++
+         * +++ did not fill the buffer, we      +++
+         * +++ must split it into a sub-binary. +++
+         */
+
+        SSDBG( descP,
+               ("SOCKET",
+                "recv_check_partial -> [%d] split buffer\r\n", toRead) );
+
+        res = recv_check_partial_done(env, descP, read, bufP, sockRef);
+
+    } else {
+
+        SSDBG( descP, ("SOCKET", "recv_check_partial -> [%d] "
+                       "only part of message - expect more\r\n", toRead) );
+
+        res = recv_check_partial_part(env, descP, read, bufP, sockRef, recvRef);
+    }
+
+    return res;
+}
+
+
+
+/* *** recv_check_partial_done ***
+ *
+ * A successful but only partial recv, which fulfilled the required read.
+ */
+static
+ERL_NIF_TERM recv_check_partial_done(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     int              read,
+                                     ErlNifBinary*    bufP,
+                                     ERL_NIF_TERM     sockRef)
+{
+    ERL_NIF_TERM data;
+
+    descP->rNumCnt = 0;
+    // cnt_inc(&descP->readPkgCnt,  1);
+    SOCK_CNT_INC(env, descP, sockRef, atom_read_pkg, &descP->readPkgCnt, 1);
+    // cnt_inc(&descP->readByteCnt, read);
+    SOCK_CNT_INC(env, descP, sockRef, atom_read_byte, &descP->readByteCnt, read);
+
+    recv_update_current_reader(env, descP, sockRef);
+
+    /* This transfers "ownership" of the *allocated* binary to an
+     * erlang term (no need for an explicit free).
+     */
+    data = MKBIN(env, bufP);
+    data = MKSBIN(env, data, 0, read);
+
+    SSDBG( descP,
+           ("SOCKET", "recv_check_partial_done -> [%d] done\r\n", read) );
+
+    return esock_make_ok3(env, atom_true, data);
+}
+
+
+
+/* *** recv_check_partial_part ***
+ *
+ * A successful but only partial recv, which only partly fulfilled
+ * the required read.
+ */
+static
+ERL_NIF_TERM recv_check_partial_part(ErlNifEnv*       env,
+                                     ESockDescriptor* descP,
+                                     int              read,
+                                     ErlNifBinary*    bufP,
+                                     ERL_NIF_TERM     sockRef,
+                                     ERL_NIF_TERM     recvRef)
+{
+    ERL_NIF_TERM res, reason, data;
+    char*        xres;
+    int          sres;
+
+    if ((xres = recv_init_current_reader(env, descP, recvRef)) != NULL) {
+        FREE_BIN(bufP);
+        return esock_make_error_str(env, xres);
+    }
+
+    data = MKBIN(env, bufP);
+    data = MKSBIN(env, data, 0, read);
+
+    // cnt_inc(&descP->readByteCnt, read);
+    SOCK_CNT_INC(env, descP, sockRef, atom_read_byte, &descP->readByteCnt, read);
+
+    /* SELECT for more data */
+
+    sres = esock_select_read(env, descP->sock, descP, NULL,
+                             sockRef, recvRef);
+    if (sres < 0) {
+        /* Result: {error, Reason}
+         * Reason: {select_failed, sres, data}
+         */
+        reason = MKT3(env, esock_atom_select_failed, MKI(env, sres), data);
+        res    = esock_make_error(env, reason);
+
+    } else {
+
+        res = esock_make_ok3(env, atom_false, data);
+
+    }
+
+    /* This transfers "ownership" of the *allocated* binary to an
+     * erlang term (no need for an explicit free).
+     */
+    return res;
+}
+
+
+
+
+
+/* The recvfrom function delivers one (1) message. If our buffer
+ * is to small, the message will be truncated. So, regardless
+ * if we filled the buffer or not, we have got what we are going
+ * to get regarding this message.
+ */
+static
+ERL_NIF_TERM recvfrom_check_result(ErlNifEnv*       env,
+                                   ESockDescriptor* descP,
+                                   int              read,
+                                   int              saveErrno,
+                                   ErlNifBinary*    bufP,
+                                   ESockAddress*    fromAddrP,
+                                   unsigned int     fromAddrLen,
+                                   ERL_NIF_TERM     sockRef,
+                                   ERL_NIF_TERM     recvRef)
+{
+    ERL_NIF_TERM data, res;
+
+    SSDBG( descP,
+           ("SOCKET", "recvfrom_check_result -> entry with"
+            "\r\n   read:      %d"
+            "\r\n   saveErrno: %d"
+            "\r\n   recvRef:   %T"
+            "\r\n", read, saveErrno, recvRef) );
+
+    if (read < 0) {
+
+        /* +++ Error handling +++ */
+
+        res = recv_check_fail(env, descP, saveErrno, bufP, NULL,
+                              sockRef, recvRef);
+
+    } else {
+
+        /* +++ We sucessfully got a message - time to encode the address +++ */
+
+        ERL_NIF_TERM eSockAddr;
+
+        esock_encode_sockaddr(env,
+                              fromAddrP, fromAddrLen,
+                              &eSockAddr);
+
+        if (read == bufP->size) {
+
+            data = MKBIN(env, bufP);
+
+        } else {
+
+            /* +++ We got a chunk of data but +++
+             * +++ since we did not fill the  +++
+             * +++ buffer, we must split it   +++
+             * +++ into a sub-binary.         +++
+             */
+
+            data = MKBIN(env, bufP);
+            data = MKSBIN(env, data, 0, read);
+        }
+
+        // cnt_inc(&descP->readPkgCnt,  1);
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_pkg, &descP->readPkgCnt, 1);
+        // cnt_inc(&descP->readByteCnt, read);
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_byte,
+                     &descP->readByteCnt, read);
+
+        recv_update_current_reader(env, descP, sockRef);
+        
+        res = esock_make_ok2(env, MKT2(env, eSockAddr, data));
+
+    }
+
+    return res;
+
+}
+
+
+
+/* *** recvmsg_check_result ***
+ *
+ * The recvmsg function delivers one (1) message. If our buffer
+ * is to small, the message will be truncated. So, regardless
+ * if we filled the buffer or not, we have got what we are going
+ * to get regarding this message.
+ */
+static
+ERL_NIF_TERM recvmsg_check_result(ErlNifEnv*       env,
+                                  ESockDescriptor* descP,
+                                  int              read,
+                                  int              saveErrno,
+                                  struct msghdr*   msgHdrP,
+                                  ErlNifBinary*    dataBufP,
+                                  ErlNifBinary*    ctrlBufP,
+                                  ERL_NIF_TERM     sockRef,
+                                  ERL_NIF_TERM     recvRef)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP,
+           ("SOCKET", "recvmsg_check_result -> entry with"
+            "\r\n   read:      %d"
+            "\r\n   saveErrno: %d"
+            "\r\n   recvRef:   %T"
+            "\r\n", read, saveErrno, recvRef) );
+
+
+    /* <KOLLA>
+     *
+     * We need to handle read = 0 for other type(s) (DGRAM) when
+     * its actually valid to read 0 bytes.
+     *
+     * </KOLLA>
+     */
+    
+    if ((read == 0) && (descP->type == SOCK_STREAM)) {
+        
+        /*
+         * When a stream socket peer has performed an orderly shutdown,
+         * the return value will be 0 (the traditional "end-of-file" return).
+         *
+         * *We* do never actually try to read 0 bytes from a stream socket!
+         */
+
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_fails, &descP->readFails, 1);
+
+        FREE_BIN(dataBufP); FREE_BIN(ctrlBufP);
+
+        return esock_make_error(env, atom_closed);
+
+    }
+
+
+    /* There is a special case: If the provided 'to read' value is
+     * zero (0). That means that we reads as much as we can, using
+     * the default read buffer size.
+     */
+
+    if (read < 0) {
+
+        /* +++ Error handling +++ */
+
+        res = recv_check_fail(env, descP, saveErrno, dataBufP, ctrlBufP,
+                              sockRef, recvRef);
+
+    } else {
+
+        /* +++ We sucessfully got a message - time to encode it +++ */
+
+        res = recvmsg_check_msg(env, descP, read, msgHdrP,
+                                dataBufP, ctrlBufP, sockRef);
+
+    }
+
+    return res;
+
+}
+
+
+
+/* *** recvmsg_check_msg ***
+ *
+ * We successfully read one message. Time to process.
+ */
+static
+ERL_NIF_TERM recvmsg_check_msg(ErlNifEnv*       env,
+                               ESockDescriptor* descP,
+                               int              read,
+                               struct msghdr*   msgHdrP,
+                               ErlNifBinary*    dataBufP,
+                               ErlNifBinary*    ctrlBufP,
+                               ERL_NIF_TERM     sockRef)
+{
+    ERL_NIF_TERM res, eMsgHdr;
+    char*        xres;
+
+    /*
+     * <KOLLA>
+     *
+     * The return value of recvmsg is the *total* number of bytes
+     * that where successfully read. This data has been put into
+     * the *IO vector*.
+     *
+     * </KOLLA>
+     */
+
+    if ((xres = encode_msghdr(env, descP,
+                              read, msgHdrP, dataBufP, ctrlBufP,
+                              &eMsgHdr)) != NULL) {
+
+        SSDBG( descP,
+               ("SOCKET",
+                "recvmsg_check_result -> "
+                "(msghdr) encode failed: %s\r\n", xres) );
+
+        /* So this is a bit strange. We did "successfully" read 'read' bytes,
+         * but then we fail to process the message header. So what counters
+         * shall we increment?
+         *    Only failure?
+         *    Or only success (pkg and byte), since the read was "ok" (or was it?)
+         *    Or all of them?
+         *
+         * For now, we increment all three...
+         */
+         
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_fails, &descP->readFails, 1);
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_pkg, &descP->readPkgCnt, 1);
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_byte,
+                     &descP->readByteCnt, read);
+
+        recv_update_current_reader(env, descP, sockRef);
+
+        FREE_BIN(dataBufP); FREE_BIN(ctrlBufP);
+
+        res = esock_make_error_str(env, xres);
+
+    } else {
+
+        SSDBG( descP,
+               ("SOCKET", "recvmsg_check_result -> (msghdr) encode ok\r\n") );
+
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_pkg, &descP->readPkgCnt, 1);
+        SOCK_CNT_INC(env, descP, sockRef, atom_read_byte,
+                     &descP->readByteCnt, read);
+
+        recv_update_current_reader(env, descP, sockRef);
+
+        res = esock_make_ok2(env, eMsgHdr);
+    }
+
+    return res;
+}
+
+
+
+
+/* +++ encode_msghdr +++
+ *
+ * Encode a msghdr (recvmsg). In erlang its represented as
+ * a map, which has a specific set of attributes:
+ *
+ *     addr (source address) - sockaddr()
+ *     iov                   - [binary()]
+ *     ctrl                  - [cmsghdr()]
+ *     flags                 - msghdr_flags()
+ */
+
+extern
+char* encode_msghdr(ErlNifEnv*       env,
+                    ESockDescriptor* descP,
+                    int              read,
+                    struct msghdr*   msgHdrP,
+                    ErlNifBinary*    dataBufP,
+                    ErlNifBinary*    ctrlBufP,
+                    ERL_NIF_TERM*    eSockAddr)
+{
+    char*        xres;
+    ERL_NIF_TERM addr, iov, ctrl, flags;
+
+    SSDBG( descP,
+           ("SOCKET", "encode_msghdr -> entry with"
+            "\r\n   read: %d"
+            "\r\n", read) );
+
+    /* The address is not used if we are connected (unless, maybe,
+     * family is 'local'), so check (length = 0) before we try to encodel
+     */
+    if (msgHdrP->msg_namelen != 0) {
+        if ((xres = esock_encode_sockaddr(env,
+                                          (ESockAddress*) msgHdrP->msg_name,
+                                          msgHdrP->msg_namelen,
+                                          &addr)) != NULL)
+            return xres;
+    } else {
+        addr = esock_atom_undefined;
+    }
+
+    SSDBG( descP, ("SOCKET", "encode_msghdr -> try encode iov\r\n") );
+    if ((xres = esock_encode_iov(env,
+                                 read,
+                                 msgHdrP->msg_iov,
+                                 msgHdrP->msg_iovlen,
+                                 dataBufP,
+                                 &iov)) != NULL)
+        return xres;
+
+    SSDBG( descP, ("SOCKET", "encode_msghdr -> try encode cmsghdrs\r\n") );
+    if ((xres = encode_cmsghdrs(env, descP, ctrlBufP, msgHdrP, &ctrl)) != NULL)
+        return xres;
+
+    SSDBG( descP, ("SOCKET", "encode_msghdr -> try encode flags\r\n") );
+    if ((xres = encode_msghdr_flags(env, descP, msgHdrP->msg_flags, &flags)) != NULL)
+        return xres;
+
+    SSDBG( descP,
+           ("SOCKET", "encode_msghdr -> components encoded:"
+            "\r\n   addr:  %T"
+            "\r\n   ctrl:  %T"
+            "\r\n   flags: %T"
+           "\r\n", addr, ctrl, flags) );
+    {
+        ERL_NIF_TERM keys[]  = {esock_atom_addr,
+                                esock_atom_iov,
+                                esock_atom_ctrl,
+                                esock_atom_flags};
+        ERL_NIF_TERM vals[]  = {addr, iov, ctrl, flags};
+        unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+        unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+        ERL_NIF_TERM tmp;
+        
+        ESOCK_ASSERT( (numKeys == numVals) );
+        
+        SSDBG( descP, ("SOCKET", "encode_msghdr -> create msghdr map\r\n") );
+        if (!MKMA(env, keys, vals, numKeys, &tmp))
+            return ESOCK_STR_EINVAL;
+
+        SSDBG( descP, ("SOCKET", "encode_msghdr -> msghdr encoded\r\n") );
+
+        *eSockAddr = tmp;
+    }
+
+    SSDBG( descP, ("SOCKET", "encode_msghdr -> done\r\n") );
+
+    return NULL;
+}
+
+
+
+
+/* +++ encode_cmsghdrs +++
+ *
+ * Encode a list of cmsghdr(). There can be 0 or more cmsghdr "blocks".
+ *
+ * Our "problem" is that we have no idea how many control messages
+ * we have.
+ *
+ * The cmsgHdrP arguments points to the start of the control data buffer,
+ * an actual binary. Its the only way to create sub-binaries. So, what we
+ * need to continue processing this is to turn that into an binary erlang 
+ * term (which can then in turn be turned into sub-binaries).
+ *
+ * We need the cmsgBufP (even though cmsgHdrP points to it) to be able
+ * to create sub-binaries (one for each cmsg hdr).
+ *
+ * The TArray (term array) is created with the size of 128, which should
+ * be enough. But if its not, then it will be automatically realloc'ed during
+ * add. Once we are done adding hdr's to it, we convert the tarray to a list.
+ */
+
+extern
+char* encode_cmsghdrs(ErlNifEnv*       env,
+                      ESockDescriptor* descP,
+                      ErlNifBinary*    cmsgBinP,
+                      struct msghdr*   msgHdrP,
+                      ERL_NIF_TERM*    eCMsgHdr)
+{
+    ERL_NIF_TERM    ctrlBuf  = MKBIN(env, cmsgBinP); // The *entire* binary
+    SocketTArray    cmsghdrs = TARRAY_CREATE(128);
+    struct cmsghdr* firstP   = CMSG_FIRSTHDR(msgHdrP);
+    struct cmsghdr* currentP;
+    
+    SSDBG( descP, ("SOCKET", "encode_cmsghdrs -> entry when"
+                   "\r\n   msg ctrl len:  %d"
+                   "\r\n   (ctrl) firstP: 0x%lX"
+                   "\r\n",
+                   msgHdrP->msg_controllen, firstP) );
+
+    for (currentP = firstP;
+         /*
+          * In *old* versions of darwin, the CMSG_FIRSTHDR does not
+          * check the msg_controllen, so we do it here.
+          * We should really test this stuff during configure,
+          * but for now, this will have to do.
+          */
+#if defined(__DARWIN__)
+         (msgHdrP->msg_controllen >= sizeof(struct cmsghdr)) && (currentP != NULL);
+#else
+         (currentP != NULL);
+#endif
+         currentP = CMSG_NXTHDR(msgHdrP, currentP)) {
+
+        SSDBG( descP,
+               ("SOCKET", "encode_cmsghdrs -> process cmsg header when"
+                "\r\n   TArray Size: %d"
+                "\r\n", TARRAY_SZ(cmsghdrs)) );
+
+        /* MUST check this since on Linux the returned "cmsg" may actually
+         * go too far!
+         */
+        if (((CHARP(currentP) + currentP->cmsg_len) - CHARP(firstP)) >
+            msgHdrP->msg_controllen) {
+
+            /* Ouch, fatal error - give up 
+             * We assume we cannot trust any data if this is wrong.
+             */
+
+            SSDBG( descP,
+                   ("SOCKET", "encode_cmsghdrs -> check failed when: "
+                    "\r\n   currentP:           0x%lX"
+                    "\r\n   (current) cmsg_len: %d"
+                    "\r\n   firstP:             0x%lX"
+                    "\r\n   =>                  %d"
+                    "\r\n   msg ctrl len:       %d"
+                    "\r\n",
+                    CHARP(currentP), currentP->cmsg_len, CHARP(firstP),
+                    (CHARP(currentP) + currentP->cmsg_len) - CHARP(firstP),
+                    msgHdrP->msg_controllen) );
+
+            TARRAY_DELETE(cmsghdrs);
+            return ESOCK_STR_EINVAL;
+        } else {
+            ERL_NIF_TERM   level, type, data;
+            unsigned char* dataP   = (unsigned char*) CMSG_DATA(currentP);
+            size_t         dataPos = dataP - cmsgBinP->data;
+            size_t         dataLen = currentP->cmsg_len - (CHARP(currentP)-CHARP(dataP));
+
+            SSDBG( descP,
+                   ("SOCKET", "encode_cmsghdrs -> cmsg header data: "
+                    "\r\n   dataPos: %d"
+                    "\r\n   dataLen: %d"
+                    "\r\n", dataPos, dataLen) );
+
+            /* We can't give up just because its an unknown protocol,
+             * so if its a protocol we don't know, we return its integer 
+             * value and leave it to the user.
+             */
+            if (encode_cmsghdr_level(env, currentP->cmsg_level, &level) != NULL)
+                level = MKI(env, currentP->cmsg_level);
+
+            if (encode_cmsghdr_type(env,
+                                    currentP->cmsg_level, currentP->cmsg_type,
+                                    &type) != NULL)
+                type = MKI(env, currentP->cmsg_type);
+
+            if (encode_cmsghdr_data(env, ctrlBuf,
+                                    currentP->cmsg_level,
+                                    currentP->cmsg_type,
+                                    dataP, dataPos, dataLen,
+                                    &data) != NULL)
+                data = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+
+            SSDBG( descP,
+                   ("SOCKET", "encode_cmsghdrs -> "
+                    "\r\n   level: %T"
+                    "\r\n   type:  %T"
+                    "\r\n   data:  %T"
+                    "\r\n", level, type, data) );
+
+            /* And finally create the 'cmsghdr' map -
+             * and if successfull add it to the tarray.
+             */
+            {
+                ERL_NIF_TERM keys[]  = {esock_atom_level,
+                                        esock_atom_type,
+                                        esock_atom_data};
+                ERL_NIF_TERM vals[]  = {level, type, data};
+                unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+                unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+                ERL_NIF_TERM cmsgHdr;
+
+                /* Guard agains cut-and-paste errors */
+                ESOCK_ASSERT( (numKeys == numVals) );
+            
+                if (!MKMA(env, keys, vals, numKeys, &cmsgHdr)) {
+                    TARRAY_DELETE(cmsghdrs);
+                    return ESOCK_STR_EINVAL;
+                }
+
+                /* And finally add it to the list... */
+                TARRAY_ADD(cmsghdrs, cmsgHdr);
+            }
+        }
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "encode_cmsghdrs -> cmsg headers processed when"
+            "\r\n   TArray Size: %d"
+            "\r\n", TARRAY_SZ(cmsghdrs)) );
+
+    /* The tarray is populated - convert it to a list */
+    TARRAY_TOLIST(cmsghdrs, env, eCMsgHdr);
+
+    return NULL;
+}
+
+
+
+/* +++ decode_cmsghdrs +++
+ *
+ * Decode a list of cmsghdr(). There can be 0 or more cmsghdr "blocks".
+ *
+ * Each element can either be a (erlang) map that needs to be decoded,
+ * or a (erlang) binary that just needs to be appended to the control
+ * buffer.
+ *
+ * Our "problem" is that we have no idea much memory we actually need.
+ *
+ */
+
+extern
+char* decode_cmsghdrs(ErlNifEnv*       env,
+                      ESockDescriptor* descP,
+                      ERL_NIF_TERM     eCMsgHdr,
+                      char*            cmsgHdrBufP,
+                      size_t           cmsgHdrBufLen,
+                      size_t*          cmsgHdrBufUsed)
+{
+    ERL_NIF_TERM elem, tail, list;
+    char*        bufP;
+    size_t       rem, used, totUsed = 0;
+    unsigned int len;
+    int          i;
+    char*        xres;
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdrs -> entry with"
+                   "\r\n   cmsgHdrBufP:   0x%lX"
+                   "\r\n   cmsgHdrBufLen: %d"
+                   "\r\n", cmsgHdrBufP, cmsgHdrBufLen) );
+
+    if (IS_LIST(env, eCMsgHdr) && GET_LIST_LEN(env, eCMsgHdr, &len)) {
+
+        SSDBG( descP, ("SOCKET", "decode_cmsghdrs -> list length: %d\r\n", len) );
+
+        for (i = 0, list = eCMsgHdr, rem  = cmsgHdrBufLen, bufP = cmsgHdrBufP;
+             i < len; i++) {
+            
+            SSDBG( descP, ("SOCKET", "decode_cmsghdrs -> process elem %d:"
+                           "\r\n   (buffer) rem:     %u"
+                           "\r\n   (buffer) totUsed: %u"
+                           "\r\n", i, rem, totUsed) );
+
+            /* Extract the (current) head of the (cmsg hdr) list */
+            if (!GET_LIST_ELEM(env, list, &elem, &tail))
+                return ESOCK_STR_EINVAL;
+            
+            used = 0; // Just in case...
+            if ((xres = decode_cmsghdr(env, descP, elem, bufP, rem, &used)) != NULL)
+                return xres;
+
+            bufP     = CHARP( ULONG(bufP) + used );
+            rem      = SZT( rem - used );
+            list     = tail;
+            totUsed += used;
+
+        }
+
+        SSDBG( descP, ("SOCKET",
+                       "decode_cmsghdrs -> all %d ctrl headers processed\r\n",
+                       len) );
+
+        xres = NULL;
+    } else {
+        xres = ESOCK_STR_EINVAL;
+    }
+
+    *cmsgHdrBufUsed = totUsed;
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdrs -> done with %s when"
+                   "\r\n   totUsed = %u\r\n",
+                   ((xres != NULL) ? xres : "NULL"), totUsed) );
+
+    return xres;
+}
+
+
+/* +++ decode_cmsghdr +++
+ *
+ * Decode one cmsghdr(). Put the "result" into the buffer and advance the
+ * pointer (of the buffer) afterwards. Also update 'rem' accordingly.
+ * But before the actual decode, make sure that there is enough room in 
+ * the buffer for the cmsg header (sizeof(*hdr) < rem).
+ *
+ * The eCMsgHdr should be a map with three fields: 
+ *
+ *     level :: cmsghdr_level()   (socket | protocol() | integer())
+ *     type  :: cmsghdr_type()    (atom() | integer())
+ *                                What values are valid depend on the level
+ *     data  :: cmsghdr_data()    (term() | binary())
+ *                                The type of the data depends on
+ *                                level and type, but can be a binary,
+ *                                which means that the data is already coded.
+ */
+extern
+char* decode_cmsghdr(ErlNifEnv*       env,
+                     ESockDescriptor* descP,
+                     ERL_NIF_TERM     eCMsgHdr,
+                     char*            bufP,
+                     size_t           rem,
+                     size_t*          used)
+{
+    SSDBG( descP, ("SOCKET", "decode_cmsghdr -> entry with"
+                   "\r\n   eCMsgHdr: %T"
+                   "\r\n", eCMsgHdr) );
+
+    if (IS_MAP(env, eCMsgHdr)) {
+        ERL_NIF_TERM eLevel, eType, eData;
+        int          level, type;
+        char*        xres;
+
+        /* First extract all three attributes (as terms) */
+
+        if (!GET_MAP_VAL(env, eCMsgHdr, esock_atom_level, &eLevel))
+            return ESOCK_STR_EINVAL;
+        
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> eLevel: %T"
+                       "\r\n", eLevel) );
+
+        if (!GET_MAP_VAL(env, eCMsgHdr, esock_atom_type, &eType))
+            return ESOCK_STR_EINVAL;
+        
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> eType:  %T"
+                       "\r\n", eType) );
+
+        if (!GET_MAP_VAL(env, eCMsgHdr, esock_atom_data, &eData))
+            return ESOCK_STR_EINVAL;
+
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> eData:  %T"
+                       "\r\n", eData) );
+
+        /* Second, decode level */
+        if ((xres = decode_cmsghdr_level(env, eLevel, &level)) != NULL)
+            return xres;
+
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> level:  %d\r\n", level) );
+
+        /* third, decode type */
+        if ((xres = decode_cmsghdr_type(env, level, eType, &type)) != NULL)
+            return xres;
+        
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> type:   %d\r\n", type) );
+
+        /* And finally data
+         * If its a binary, we are done. Otherwise, we need to check
+         * level and type to know what kind of data to expect.
+         */
+
+        return decode_cmsghdr_data(env, descP, bufP, rem, level, type, eData, used);
+
+    } else {
+        *used = 0;
+        return ESOCK_STR_EINVAL;
+    }
+
+    return NULL;
+}
+
+
+/* *** decode_cmsghdr_data ***
+ *
+ * For all combinations of level and type we accept a binary as data,
+ * so we begin by testing for that. If its not a binary, then we check
+ * level (ip) and type (tos or ttl), in which case the data *must* be
+ * an integer and ip_tos() respectively.
+ */
+static
+char* decode_cmsghdr_data(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          char*            bufP,
+                          size_t           rem,
+                          int              level,
+                          int              type,
+                          ERL_NIF_TERM     eData,
+                          size_t*          used)
+{
+    char* xres;
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> entry with"
+                   "\r\n   eData: %T"
+                   "\r\n", eData) );
+
+    if (IS_BIN(env, eData)) {
+        ErlNifBinary bin;
+        
+        if (GET_BIN(env, eData, &bin)) {
+            SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> "
+                           "do final decode with binary\r\n") );
+            return decode_cmsghdr_final(descP, bufP, rem, level, type,
+                                        (char*) bin.data, bin.size,
+                                        used);
+        } else {
+            *used = 0;
+            xres  = ESOCK_STR_EINVAL;
+        }
+    } else {
+
+        /* Its *not* a binary so we need to look at what level and type 
+         * we have and treat them individually.
+         */
+
+        switch (level) {
+#if defined(SOL_IP)
+        case SOL_IP:
+#else
+        case IPPROTO_IP:
+#endif
+            switch (type) {
+#if defined(IP_TOS)
+            case IP_TOS:
+                {
+                    int data;
+                    if (decode_ip_tos(env, eData, &data)) {
+                        SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> "
+                                       "do final decode with tos\r\n") );
+                        return decode_cmsghdr_final(descP, bufP, rem, level, type,
+                                                    (char*) &data,
+                                                    sizeof(data),
+                                                    used);
+                    } else {
+                        *used = 0;
+                        xres  = ESOCK_STR_EINVAL;
+                    }
+                }
+                break;
+#endif
+
+#if defined(IP_TTL)
+            case IP_TTL:
+                {
+                    int data;
+                    if (GET_INT(env, eData, &data)) {
+                        SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> "
+                                       "do final decode with ttl\r\n") );
+                        return decode_cmsghdr_final(descP, bufP, rem, level, type,
+                                                    (char*) &data,
+                                                    sizeof(data),
+                                                    used);
+                    } else {
+                        *used = 0;
+                        xres  = ESOCK_STR_EINVAL;
+                    }
+                }
+                break;
+#endif
+
+            }
+            break;
+
+        default:
+            *used = 0;
+            xres  = ESOCK_STR_EINVAL;
+            break;
+        }        
+
+    }
+
+    return xres;
+}
+                              
+
+/* *** decode_cmsghdr_final ***
+ *
+ * This does the final create of the cmsghdr (including the data copy).
+ */
+static
+char* decode_cmsghdr_final(ESockDescriptor* descP,
+                           char*            bufP,
+                           size_t           rem,
+                           int              level,
+                           int              type,
+                           char*            data,
+                           int              sz,
+                           size_t*          used)
+{
+    int len   = CMSG_LEN(sz);
+    int space = CMSG_SPACE(sz);
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> entry when"
+                   "\r\n   level: %d"
+                   "\r\n   type:  %d"
+                   "\r\n   sz:    %d => %d, %d"
+                   "\r\n", level, type, sz, len, space) );
+
+    if (rem >= space) {
+        struct cmsghdr* cmsgP = (struct cmsghdr*) bufP;
+        
+        /* The header */
+        cmsgP->cmsg_len   = len;
+        cmsgP->cmsg_level = level;
+        cmsgP->cmsg_type  = type;
+
+        sys_memcpy(CMSG_DATA(cmsgP), data, sz);
+        *used = space;
+    } else {
+        *used = 0;
+        return ESOCK_STR_EINVAL;
+    }
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdr_final -> done\r\n") );
+
+    return NULL;
+}
+
+
+/* +++ encode_cmsghdr_level +++
+ *
+ * Encode the level part of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_level(ErlNifEnv*    env,
+                           int           level,
+                           ERL_NIF_TERM* eLevel)
+{
+    char* xres;
+
+    switch (level) {
+    case SOL_SOCKET:
+        *eLevel = esock_atom_socket;
+        xres    = NULL;
+        break;
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        *eLevel = esock_atom_ip;
+        xres    = NULL;
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif
+        *eLevel = esock_atom_ip;
+        xres    = NULL;
+        break;
+#endif
+
+    case IPPROTO_UDP:
+        *eLevel = esock_atom_udp;
+        xres    = NULL;
+        break;
+
+    default:
+        *eLevel = MKI(env, level);
+        xres    = NULL;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ decode_cmsghdr_level +++
+ *
+ * Decode the level part of the cmsghdr().
+ *
+ */
+
+static
+char* decode_cmsghdr_level(ErlNifEnv*   env,
+                           ERL_NIF_TERM eLevel,
+                           int*         level)
+{
+    char* xres = NULL;
+
+    if (IS_ATOM(env, eLevel)) {
+
+        if (COMPARE(eLevel, esock_atom_socket) == 0) {
+            *level = SOL_SOCKET;
+            xres   = NULL;
+        } else if (COMPARE(eLevel, esock_atom_ip) == 0) {
+#if defined(SOL_IP)
+            *level = SOL_IP;
+#else
+            *level = IPPROTO_IP;
+#endif
+            xres   = NULL;
+#if defined(HAVE_IPV6)
+        } else if (COMPARE(eLevel, esock_atom_ipv6) == 0) {
+#if defined(SOL_IPV6)
+            *level = SOL_IPV6;
+#else
+            *level = IPPROTO_IPV6;
+#endif
+            xres   = NULL;
+#endif
+        } else if (COMPARE(eLevel, esock_atom_udp) == 0) {
+            *level = IPPROTO_UDP;
+            xres   = NULL;
+        } else {
+            *level = -1;
+            xres   = ESOCK_STR_EINVAL;
+        }
+    } else if (IS_NUM(env, eLevel)) {
+        if (!GET_INT(env, eLevel, level))
+            xres = ESOCK_STR_EINVAL;
+    } else {
+        *level = -1;
+        xres   = ESOCK_STR_EINVAL;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ encode_cmsghdr_type +++
+ *
+ * Encode the type part of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_type(ErlNifEnv*    env,
+                          int           level,
+                          int           type,
+                          ERL_NIF_TERM* eType)
+{
+    char* xres = NULL;
+
+    switch (level) {
+    case SOL_SOCKET:
+        switch (type) {
+#if defined(SO_TIMESTAMP)
+        case SO_TIMESTAMP:
+            *eType = esock_atom_timestamp;
+            break;
+#endif
+
+#if defined(SCM_RIGHTS)
+        case SCM_RIGHTS:
+            *eType = esock_atom_rights;
+            break;
+#endif
+
+#if defined(SCM_CREDENTIALS)
+        case SCM_CREDENTIALS:
+            *eType = esock_atom_credentials;
+            break;
+#endif
+
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        switch (type) {
+#if defined(IP_TOS)
+        case IP_TOS:
+            *eType = esock_atom_tos;
+            break;
+#endif
+
+#if defined(IP_TTL)
+        case IP_TTL:
+            *eType = esock_atom_ttl;
+            break;
+#endif
+
+#if defined(IP_PKTINFO)
+        case IP_PKTINFO:
+            *eType = esock_atom_pktinfo;
+            break;
+#endif
+
+#if defined(IP_ORIGDSTADDR)
+        case IP_ORIGDSTADDR:
+            *eType = esock_atom_origdstaddr;
+            break;
+#endif
+
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+        case SOL_IPV6:
+#else
+        case IPPROTO_IPV6:
+#endif
+        switch (type) {
+#if defined(IPV6_PKTINFO)
+        case IPV6_PKTINFO:
+            *eType = esock_atom_pktinfo;
+            break;
+#endif
+
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+#endif
+
+    case IPPROTO_TCP:
+        switch (type) {
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+
+    case IPPROTO_UDP:
+        switch (type) {
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+
+#if defined(HAVE_SCTP)
+    case IPPROTO_SCTP:
+        switch (type) {
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+#endif
+
+    default:
+        xres = ESOCK_STR_EINVAL;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ decode_cmsghdr_type +++
+ *
+ * Decode the type part of the cmsghdr().
+ *
+ */
+
+static
+char* decode_cmsghdr_type(ErlNifEnv*   env,
+                          int          level,
+                          ERL_NIF_TERM eType,
+                          int*         type)
+{
+    char* xres = NULL;
+
+    switch (level) {
+    case SOL_SOCKET:
+        if (IS_NUM(env, eType)) {
+            if (!GET_INT(env, eType, type)) {
+                *type = -1;
+                xres  = ESOCK_STR_EINVAL;
+            }
+        } else {
+            *type = -1;
+            xres = ESOCK_STR_EINVAL;
+        }
+        break;
+
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        if (IS_ATOM(env, eType)) {
+            if (COMPARE(eType, esock_atom_tos) == 0) {
+#if defined(IP_TOS)
+                *type = IP_TOS;
+#else
+                xres  = ESOCK_STR_EINVAL;
+#endif
+            } else if (COMPARE(eType, esock_atom_ttl) == 0) {
+#if defined(IP_TTL)
+                *type = IP_TTL;
+#else
+                xres  = ESOCK_STR_EINVAL;
+#endif
+            } else {
+                xres = ESOCK_STR_EINVAL;
+            }
+        } else if (IS_NUM(env, eType)) {
+            if (!GET_INT(env, eType, type)) {
+                *type = -1;
+                xres  = ESOCK_STR_EINVAL;
+            }
+        } else {
+            *type = -1;
+            xres  = ESOCK_STR_EINVAL;
+        }
+        break;
+        
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif
+        if (IS_NUM(env, eType)) {
+            if (!GET_INT(env, eType, type)) {
+                *type = -1;
+                xres  = ESOCK_STR_EINVAL;
+            }
+        } else {
+            *type = -1;
+            xres = ESOCK_STR_EINVAL;
+        }
+        break;
+#endif
+        
+    case IPPROTO_UDP:
+        if (IS_NUM(env, eType)) {
+            if (!GET_INT(env, eType, type)) {
+                *type = -1;
+                xres  = ESOCK_STR_EINVAL;
+            }
+        } else {
+            *type = -1;
+            xres = ESOCK_STR_EINVAL;
+        }
+        break;
+
+    default:
+        *type = -1;
+        xres  = ESOCK_STR_EINVAL;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ encode_cmsghdr_data +++
+ *
+ * Encode the data part of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_data(ErlNifEnv*     env,
+                          ERL_NIF_TERM   ctrlBuf,
+                          int            level,
+                          int            type,
+                          unsigned char* dataP,
+                          size_t         dataPos,
+                          size_t         dataLen,
+                          ERL_NIF_TERM*  eCMsgHdrData)
+{
+    char* xres;
+
+    switch (level) {
+#if defined(SOL_SOCKET)
+    case SOL_SOCKET:
+        xres = encode_cmsghdr_data_socket(env, ctrlBuf, type,
+                                          dataP, dataPos, dataLen,
+                                          eCMsgHdrData);
+        break;
+#endif
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        xres = encode_cmsghdr_data_ip(env, ctrlBuf, type,
+                                      dataP, dataPos, dataLen,
+                                      eCMsgHdrData);
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif        
+        xres = encode_cmsghdr_data_ipv6(env, ctrlBuf, type,
+                                        dataP, dataPos, dataLen,
+                                        eCMsgHdrData);
+        break;
+#endif
+
+        /*
+          case IPPROTO_TCP:
+          xres = encode_cmsghdr_data_tcp(env, type, dataP, eCMsgHdrData);
+          break;
+        */
+
+        /*
+          case IPPROTO_UDP:
+          xres = encode_cmsghdr_data_udp(env, type, dataP, eCMsgHdrData);
+          break;
+        */
+
+        /*
+          #if defined(HAVE_SCTP)
+          case IPPROTO_SCTP:
+          xres = encode_cmsghdr_data_sctp(env, type, dataP, eCMsgHdrData);
+          break;
+          #endif
+        */
+
+    default:
+        *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        xres = NULL;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ encode_cmsghdr_data_socket +++
+ *
+ * Encode the data part when "protocol" = socket of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_data_socket(ErlNifEnv*     env,
+                                 ERL_NIF_TERM   ctrlBuf,
+                                 int            type,
+                                 unsigned char* dataP,
+                                 size_t         dataPos,
+                                 size_t         dataLen,
+                                 ERL_NIF_TERM*  eCMsgHdrData)
+{
+    // char* xres;
+
+    switch (type) {
+#if defined(SO_TIMESTAMP)
+    case SO_TIMESTAMP:
+        {
+            struct timeval* timeP = (struct timeval*) dataP;
+
+            if (esock_encode_timeval(env, timeP, eCMsgHdrData) != NULL)
+                *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        }
+        break;
+#endif
+
+    default:
+        *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        break;
+    }
+
+    return NULL;
+}
+
+
+
+/* +++ encode_cmsghdr_data_ip +++
+ *
+ * Encode the data part when protocol = IP of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_data_ip(ErlNifEnv*     env,
+                             ERL_NIF_TERM   ctrlBuf,
+                             int            type,
+                             unsigned char* dataP,
+                             size_t         dataPos,
+                             size_t         dataLen,
+                             ERL_NIF_TERM*  eCMsgHdrData)
+{
+    char* xres = NULL;
+
+    switch (type) {
+#if defined(IP_TOS)
+    case IP_TOS:
+        {
+            unsigned char tos = *dataP;
+            switch (IPTOS_TOS(tos)) {
+            case IPTOS_LOWDELAY:
+                *eCMsgHdrData = esock_atom_lowdelay;
+                break;
+            case IPTOS_THROUGHPUT:
+                *eCMsgHdrData = esock_atom_throughput;
+                break;
+            case IPTOS_RELIABILITY:
+                *eCMsgHdrData = esock_atom_reliability;
+                break;
+#if defined(IPTOS_MINCOST)
+            case IPTOS_MINCOST:
+                *eCMsgHdrData = esock_atom_mincost;
+                break;
+#endif
+            default:
+                *eCMsgHdrData = MKUI(env, tos);
+                break;
+            }
+        }
+        break;
+#endif
+
+#if defined(IP_TTL)
+    case IP_TTL:
+        {
+            int ttl = *((int*) dataP);
+            *eCMsgHdrData = MKI(env, ttl);
+        }
+        break;
+#endif
+
+#if defined(IP_PKTINFO)
+    case IP_PKTINFO:
+        {
+            struct in_pktinfo* pktInfoP = (struct in_pktinfo*) dataP;
+            ERL_NIF_TERM       ifIndex  = MKUI(env, pktInfoP->ipi_ifindex);
+            ERL_NIF_TERM       specDst, addr;
+
+            if ((xres = esock_encode_ip4_address(env,
+                                                 &pktInfoP->ipi_spec_dst,
+                                                 &specDst)) != NULL) {
+                *eCMsgHdrData = esock_atom_undefined;
+                return xres;
+            }
+
+            if ((xres = esock_encode_ip4_address(env,
+                                                 &pktInfoP->ipi_addr,
+                                                 &addr)) != NULL) {
+                *eCMsgHdrData = esock_atom_undefined;
+                return xres;
+            }
+
+
+            {
+                ERL_NIF_TERM keys[] = {esock_atom_ifindex,
+                                       esock_atom_spec_dst,
+                                       esock_atom_addr};
+                ERL_NIF_TERM vals[] = {ifIndex, specDst, addr};
+                unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+                unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+                ESOCK_ASSERT( (numKeys == numVals) );
+                
+                if (!MKMA(env, keys, vals, numKeys, eCMsgHdrData)) {
+                    *eCMsgHdrData = esock_atom_undefined;
+                    return ESOCK_STR_EINVAL;
+                }
+            }
+        }
+        break;
+#endif
+
+#if defined(IP_ORIGDSTADDR)
+    case IP_ORIGDSTADDR:
+        if ((xres = esock_encode_sockaddr_in4(env,
+                                              (struct sockaddr_in*) dataP,
+                                              dataLen,
+                                              eCMsgHdrData)) != NULL) {
+            *eCMsgHdrData = esock_atom_undefined;
+            return xres;            
+        }
+        break;
+#endif
+
+    default:
+        *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ encode_cmsghdr_data_ipv6 +++
+ *
+ * Encode the data part when protocol = IPv6 of the cmsghdr().
+ *
+ */
+#if defined(HAVE_IPV6)
+static
+char* encode_cmsghdr_data_ipv6(ErlNifEnv*     env,
+                               ERL_NIF_TERM   ctrlBuf,
+                               int            type,
+                               unsigned char* dataP,
+                               size_t         dataPos,
+                               size_t         dataLen,
+                               ERL_NIF_TERM*  eCMsgHdrData)
+{
+    switch (type) {
+#if defined(IPV6_PKTINFO)
+    case IPV6_PKTINFO:
+        {
+            struct in6_pktinfo* pktInfoP = (struct in6_pktinfo*) dataP;
+            ERL_NIF_TERM        ifIndex  = MKI(env, pktInfoP->ipi6_ifindex);
+            ERL_NIF_TERM        addr;
+            char*               xres;
+
+            if ((xres = esock_encode_ip6_address(env,
+                                                 &pktInfoP->ipi6_addr,
+                                                 &addr)) != NULL) {
+                *eCMsgHdrData = esock_atom_undefined;
+                return xres;
+            }
+
+            {
+                ERL_NIF_TERM keys[]  = {esock_atom_addr, esock_atom_ifindex};
+                ERL_NIF_TERM vals[]  = {addr, ifIndex};
+                unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+                unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+                ESOCK_ASSERT( (numKeys == numVals) );
+                
+                if (!MKMA(env, keys, vals, numKeys, eCMsgHdrData)) {
+                    *eCMsgHdrData = esock_atom_undefined;
+                    return ESOCK_STR_EINVAL;
+                }
+            }
+        }
+        break;
+#endif
+
+    default:
+        *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        break;
+    }
+
+    return NULL;
+}
+#endif
+
+
+
+/* +++ encode_msghdr_flags +++
+ *
+ * Encode a list of msghdr_flag().
+ *
+ * The following flags are handled: eor | trunc | ctrunc | oob | errqueue.
+ */
+
+extern
+char* encode_msghdr_flags(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          int              msgFlags,
+                          ERL_NIF_TERM*    flags)
+{
+    SSDBG( descP,
+           ("SOCKET", "encode_cmsghdrs_flags -> entry with"
+            "\r\n   msgFlags: %d (0x%lX)"
+            "\r\n", msgFlags, msgFlags) );
+
+    if (msgFlags == 0) {
+        *flags = MKEL(env);
+        return NULL;
+    } else {
+        SocketTArray ta = TARRAY_CREATE(10); // Just to be on the safe side
+
+#if defined(MSG_EOR)
+        if ((msgFlags & MSG_EOR) == MSG_EOR)
+            TARRAY_ADD(ta, esock_atom_eor);
+#endif
+
+#if defined(MSG_TRUNC)
+        if ((msgFlags & MSG_TRUNC) == MSG_TRUNC)
+            TARRAY_ADD(ta, esock_atom_trunc);
+#endif
+    
+#if defined(MSG_CTRUNC)
+        if ((msgFlags & MSG_CTRUNC) == MSG_CTRUNC)
+            TARRAY_ADD(ta, esock_atom_ctrunc);
+#endif
+    
+#if defined(MSG_OOB)
+        if ((msgFlags & MSG_OOB) == MSG_OOB)
+            TARRAY_ADD(ta, esock_atom_oob);
+#endif
+    
+#if defined(MSG_ERRQUEUE)
+        if ((msgFlags & MSG_ERRQUEUE) == MSG_ERRQUEUE)
+            TARRAY_ADD(ta, esock_atom_errqueue);
+#endif
+
+        SSDBG( descP,
+               ("SOCKET", "esock_encode_cmsghdrs -> flags processed when"
+                "\r\n   TArray size: %d"
+                "\r\n", TARRAY_SZ(ta)) );
+
+        TARRAY_TOLIST(ta, env, flags);
+
+        return NULL;
+    }
+}
+
+
+
+
+/* +++ decode the linger value +++
+ * The (socket) linger option is provided as a two tuple:
+ *
+ *       {OnOff :: boolean(), Time :: integer()}
+ *
+ */
+static
+BOOLEAN_T decode_sock_linger(ErlNifEnv* env, ERL_NIF_TERM eVal, struct linger* valP)
+{
+    const ERL_NIF_TERM* lt; // The array of the elements of the tuple
+    int                 sz; // The size of the tuple - should be 2
+    BOOLEAN_T           onOff;
+    int                 secs;
+
+    if (!GET_TUPLE(env, eVal, &sz, &lt))
+        return FALSE;
+
+    if (sz != 2)
+        return FALSE;
+
+
+    /* So fas so good - now check the two elements of the tuple. */
+
+    onOff = esock_decode_bool(lt[0]);
+
+    if (!GET_INT(env, lt[1], &secs))
+        return FALSE;
+
+    valP->l_onoff  = (onOff) ? 1 : 0;
+    valP->l_linger = secs;
+
+    return TRUE;
+}
+
+
+
+/* +++ decode the ip socket option TOS +++
+ * The (ip) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * When its an atom it can have the values:
+ *
+ *       lowdelay |  throughput | reliability | mincost
+ *
+ */
+#if defined(IP_TOS)
+static
+BOOLEAN_T decode_ip_tos(ErlNifEnv* env, ERL_NIF_TERM eVal, int* val)
+{
+    BOOLEAN_T result = FALSE;
+
+    if (IS_ATOM(env, eVal)) {
+
+        if (COMPARE(eVal, esock_atom_lowdelay) == 0) {
+            *val   = IPTOS_LOWDELAY;
+            result = TRUE;
+        } else if (COMPARE(eVal, esock_atom_throughput) == 0) {
+            *val   = IPTOS_THROUGHPUT;
+            result = TRUE;
+        } else if (COMPARE(eVal, esock_atom_reliability) == 0) {
+            *val   = IPTOS_RELIABILITY;
+            result = TRUE;
+#if defined(IPTOS_MINCOST)
+        } else if (COMPARE(eVal, esock_atom_mincost) == 0) {
+            *val   = IPTOS_MINCOST;
+            result = TRUE;
+#endif
+        } else {
+            *val   = -1;
+            result = FALSE;
+        }
+            
+    } else if (IS_NUM(env, eVal)) {
+
+        if (GET_INT(env, eVal, val)) {
+            result = TRUE;
+        } else {
+            *val   = -1;
+            result = FALSE;
+        }
+
+    } else {
+        *val   = -1;
+        result = FALSE;
+    }
+
+    return result;
+}
+#endif
+
+
+
+/* +++ decode the ip socket option MTU_DISCOVER +++
+ * The (ip) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * When its an atom it can have the values:
+ *
+ *       want | dont | do | probe
+ *
+ */
+#if defined(IP_MTU_DISCOVER)
+static
+char* decode_ip_pmtudisc(ErlNifEnv* env, ERL_NIF_TERM eVal, int* val)
+{
+    char* res = NULL;
+
+    if (IS_ATOM(env, eVal)) {
+
+        if (COMPARE(eVal, atom_want) == 0) {
+            *val = IP_PMTUDISC_WANT;
+        } else if (COMPARE(eVal, atom_dont) == 0) {
+            *val = IP_PMTUDISC_DONT;
+        } else if (COMPARE(eVal, atom_do) == 0) {
+            *val = IP_PMTUDISC_DO;
+#if defined(IP_PMTUDISC_PROBE)
+        } else if (COMPARE(eVal, atom_probe) == 0) {
+            *val = IP_PMTUDISC_PROBE;
+#endif
+        } else {
+            *val = -1;
+            res  = ESOCK_STR_EINVAL;
+        }
+
+    } else if (IS_NUM(env, eVal)) {
+
+        if (!GET_INT(env, eVal, val)) {
+            *val = -1;
+            res  = ESOCK_STR_EINVAL;
+        }
+
+    } else {
+
+        *val   = -1;
+        res  = ESOCK_STR_EINVAL;
+
+    }
+
+    return res;
+}
+#endif
+
+
+
+/* +++ decode the ipv6 socket option MTU_DISCOVER +++
+ * The (ip) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * When its an atom it can have the values:
+ *
+ *       want | dont | do | probe
+ *
+ */
+#if defined(IPV6_MTU_DISCOVER)
+static
+char* decode_ipv6_pmtudisc(ErlNifEnv* env, ERL_NIF_TERM eVal, int* val)
+{
+    char* res = NULL;
+
+    if (IS_ATOM(env, eVal)) {
+
+        if (COMPARE(eVal, atom_want) == 0) {
+            *val = IPV6_PMTUDISC_WANT;
+        } else if (COMPARE(eVal, atom_dont) == 0) {
+            *val = IPV6_PMTUDISC_DONT;
+        } else if (COMPARE(eVal, atom_do) == 0) {
+            *val = IPV6_PMTUDISC_DO;
+#if defined(IPV6_PMTUDISC_PROBE)
+        } else if (COMPARE(eVal, atom_probe) == 0) {
+            *val = IPV6_PMTUDISC_PROBE;
+#endif
+        } else {
+            *val = -1;
+            res  = ESOCK_STR_EINVAL;
+        }
+
+    } else if (IS_NUM(env, eVal)) {
+
+        if (!GET_INT(env, eVal, val)) {
+            *val = -1;
+            res  = ESOCK_STR_EINVAL;
+        }
+
+    } else {
+
+        *val   = -1;
+        res  = ESOCK_STR_EINVAL;
+
+    }
+
+    return res;
+}
+#endif
+
+
+
+/* +++ encode the ip socket option MTU_DISCOVER +++
+ * The (ip) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * If its one of the "known" values, it will be an atom:
+ *
+ *       want | dont | do | probe
+ *
+ */
+#if defined(IP_MTU_DISCOVER)
+static
+void encode_ip_pmtudisc(ErlNifEnv* env, int val, ERL_NIF_TERM* eVal)
+{
+    switch (val) {
+    case IP_PMTUDISC_WANT:
+        *eVal = atom_want;
+        break;
+
+    case IP_PMTUDISC_DONT:
+        *eVal = atom_dont;
+        break;
+
+    case IP_PMTUDISC_DO:
+        *eVal = atom_do;
+        break;
+
+#if defined(IP_PMTUDISC_PROBE)
+    case IP_PMTUDISC_PROBE:
+        *eVal = atom_probe;
+        break;
+#endif
+
+    default:
+        *eVal = MKI(env, val);
+        break;
+    }
+
+    return;
+}
+#endif
+
+
+
+/* +++ encode the ipv6 socket option MTU_DISCOVER +++
+ * The (ipv6) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * If its one of the "known" values, it will be an atom:
+ *
+ *       want | dont | do | probe
+ *
+ */
+#if defined(IPV6_MTU_DISCOVER)
+static
+void encode_ipv6_pmtudisc(ErlNifEnv* env, int val, ERL_NIF_TERM* eVal)
+{
+    switch (val) {
+    case IPV6_PMTUDISC_WANT:
+        *eVal = atom_want;
+        break;
+
+    case IPV6_PMTUDISC_DONT:
+        *eVal = atom_dont;
+        break;
+
+    case IPV6_PMTUDISC_DO:
+        *eVal = atom_do;
+        break;
+
+#if defined(IPV6_PMTUDISC_PROBE)
+    case IPV6_PMTUDISC_PROBE:
+        *eVal = atom_probe;
+        break;
+#endif
+
+    default:
+        *eVal = MKI(env, val);
+        break;
+    }
+
+    return;
+}
+#endif
+
+
+
+/* +++ decocde the native getopt option +++
+ * The option is in this case provide in the form of a two tuple:
+ *
+ *           {NativeOpt, ValueSize}
+ *
+ * NativeOpt :: integer()
+ * ValueSize :: int | bool | non_neg_integer()
+ *
+ */
+static
+BOOLEAN_T decode_native_get_opt(ErlNifEnv* env, ERL_NIF_TERM eVal,
+                                int* opt, Uint16* valueType, int* valueSz)
+{
+    const ERL_NIF_TERM* nativeOptT;
+    int                 nativeOptTSz;
+
+    /* First, get the tuple and verify its size (2) */
+
+    if (!GET_TUPLE(env, eVal, &nativeOptTSz, &nativeOptT))
+        return FALSE;
+
+    if (nativeOptTSz != 2)
+        return FALSE;
+
+    /* So far so good.
+     * First element is an integer.
+     * Second element is an atom or an integer.
+     * The only "types" that we support at the moment are:
+     *
+     *            bool - Which is actually a integer
+     *                   (but will be *returned* as a boolean())
+     *            int  - Just short for integer
+     */
+
+    if (!GET_INT(env, nativeOptT[0], opt))
+        return FALSE;
+
+    if (IS_ATOM(env, nativeOptT[1])) {
+
+        if (COMPARE(nativeOptT[1], atom_int) == 0) {
+            SGDBG( ("SOCKET", "decode_native_get_opt -> int\r\n") );
+            *valueType = ESOCK_OPT_VALUE_TYPE_INT;
+            *valueSz   = sizeof(int); // Just to be sure
+        } else if (COMPARE(nativeOptT[1], atom_bool) == 0) {
+            SGDBG( ("SOCKET", "decode_native_get_opt -> bool\r\n") );
+            *valueType = ESOCK_OPT_VALUE_TYPE_BOOL;
+            *valueSz   = sizeof(int); // Just to be sure
+        } else {
+            return FALSE;
+        }
+    } else if (IS_NUM(env, nativeOptT[1])) {
+        if (GET_INT(env, nativeOptT[1], valueSz)) {
+            SGDBG( ("SOCKET", "decode_native_get_opt -> unspec\r\n") );
+            *valueType = ESOCK_OPT_VALUE_TYPE_UNSPEC;
+        } else {
+            return FALSE;
+        }
+    } else {
+        return FALSE;
+    }
+
+    SGDBG( ("SOCKET", "decode_native_get_opt -> done\r\n") );
+
+    return TRUE;
+}
+
+
+
+/* +++ encode the ip socket option tos +++
+ * The (ip) option can be provide as:
+ *
+ *       lowdelay |  throughput | reliability | mincost | integer()
+ *
+ */
+static
+ERL_NIF_TERM encode_ip_tos(ErlNifEnv* env, int val)
+{
+    ERL_NIF_TERM result;
+
+    switch (IPTOS_TOS(val)) {
+    case IPTOS_LOWDELAY:
+        result = esock_make_ok2(env, esock_atom_lowdelay);
+        break;
+
+    case IPTOS_THROUGHPUT:
+        result = esock_make_ok2(env, esock_atom_throughput);
+        break;
+
+    case IPTOS_RELIABILITY:
+        result = esock_make_ok2(env, esock_atom_reliability);
+        break;
+
+#if defined(IPTOS_MINCOST)
+    case IPTOS_MINCOST:
+        result = esock_make_ok2(env, esock_atom_mincost);
+        break;
+#endif
+
+    default:
+        result = esock_make_ok2(env, MKI(env, val));
+        break;
+    }
+
+    return result;
+}
+
+
+
+
+
+/* *** alloc_descriptor ***
+ *
+ * Allocate and perform basic initialization of a socket descriptor.
+ *
+ */
+static
+ESockDescriptor* alloc_descriptor(SOCKET sock, HANDLE event)
+{
+    ESockDescriptor* descP;
+
+    if ((descP = enif_alloc_resource(esocks, sizeof(ESockDescriptor))) != NULL) {
+        char buf[64]; /* Buffer used for building the mutex name */
+
+        descP->pattern        = ESOCK_DESC_PATTERN_CREATED;
+
+        enif_set_pid_undefined(&descP->connPid);
+        MON_INIT(&descP->connMon);
+
+        sprintf(buf, "esock[w,%d]", sock);
+        descP->writeMtx       = MCREATE(buf);
+        enif_set_pid_undefined(&descP->currentWriter.pid);
+        MON_INIT(&descP->currentWriter.mon);
+        descP->currentWriter.env = NULL;
+        descP->currentWriter.ref = esock_atom_undefined;
+        descP->currentWriterP = NULL; // currentWriter not used
+        descP->writersQ.first = NULL;
+        descP->writersQ.last  = NULL;
+        descP->isWritable     = FALSE; // TRUE;
+        descP->writePkgCnt    = 0;
+        descP->writeByteCnt   = 0;
+        descP->writeTries     = 0;
+        descP->writeWaits     = 0;
+        descP->writeFails     = 0;
+
+        sprintf(buf, "esock[r,%d]", sock);
+        descP->readMtx        = MCREATE(buf);
+        enif_set_pid_undefined(&descP->currentReader.pid);
+        MON_INIT(&descP->currentReader.mon);
+        descP->currentReader.env = NULL;
+        descP->currentReader.ref = esock_atom_undefined;
+        descP->currentReaderP = NULL; // currentReader not used
+        descP->readersQ.first = NULL;
+        descP->readersQ.last  = NULL;
+        descP->isReadable     = FALSE; // TRUE;
+        descP->readPkgCnt     = 0;
+        descP->readByteCnt    = 0;
+        descP->readTries      = 0;
+        descP->readWaits      = 0;
+        descP->readFails      = 0;
+
+        sprintf(buf, "esock[acc,%d]", sock);
+        descP->accMtx           = MCREATE(buf);
+        enif_set_pid_undefined(&descP->currentAcceptor.pid);
+        MON_INIT(&descP->currentAcceptor.mon);
+        descP->currentAcceptor.env = NULL;
+        descP->currentAcceptor.ref = esock_atom_undefined;
+        descP->currentAcceptorP = NULL; // currentAcceptor not used
+        descP->acceptorsQ.first = NULL;
+        descP->acceptorsQ.last  = NULL;
+
+        sprintf(buf, "esock[close,%d]", sock);
+        descP->closeMtx         = MCREATE(buf);
+        descP->closeEnv         = NULL;
+        descP->closeRef         = esock_atom_undefined;
+        enif_set_pid_undefined(&descP->closerPid);
+        MON_INIT(&descP->closerMon);
+
+        sprintf(buf, "esock[cfg,%d]", sock);
+        descP->cfgMtx           = MCREATE(buf);
+        descP->rBufSz           = ESOCK_RECV_BUFFER_SIZE_DEFAULT;
+        descP->rNum             = 0;
+        descP->rNumCnt          = 0;
+        descP->rCtrlSz          = ESOCK_RECV_CTRL_BUFFER_SIZE_DEFAULT;
+        descP->wCtrlSz          = ESOCK_SEND_CTRL_BUFFER_SIZE_DEFAULT;
+        descP->iow              = FALSE;
+        descP->dbg              = ESOCK_DEBUG_DEFAULT;
+
+        descP->sock             = sock;
+        descP->event            = event;
+
+        enif_set_pid_undefined(&descP->ctrlPid);
+        MON_INIT(&descP->ctrlMon);
+
+    }
+
+    return descP;
+}
+
+
+
+/* Decrement counters for when a socket is closed
+ */
+static
+void dec_socket(int domain, int type, int protocol)
+{
+    MLOCK(data.cntMtx);
+
+    cnt_dec(&data.numSockets, 1);
+
+    /* *** Domain counter *** */
+    if (domain == AF_INET)
+        cnt_dec(&data.numDomainInet, 1);
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    else if (domain == AF_INET6)
+        cnt_dec(&data.numDomainInet6, 1);
+#endif
+#if defined(HAVE_SYS_UN_H)
+    else if (domain == AF_UNIX)
+        cnt_dec(&data.numDomainInet6, 1);
+#endif
+
+    /* *** Type counter *** */
+    if (type == SOCK_STREAM)
+        cnt_dec(&data.numTypeStreams, 1);
+    else if (type == SOCK_DGRAM)
+        cnt_dec(&data.numTypeDGrams, 1);
+#ifdef HAVE_SCTP
+    else if (type == SOCK_SEQPACKET)
+        cnt_dec(&data.numTypeSeqPkgs, 1);
+#endif
+
+    /* *** Protocol counter *** */
+    if (protocol == IPPROTO_IP)
+        cnt_dec(&data.numProtoIP, 1);
+    else if (protocol == IPPROTO_TCP)
+        cnt_dec(&data.numProtoTCP, 1);
+    else if (protocol == IPPROTO_UDP)
+        cnt_dec(&data.numProtoUDP, 1);
+#if defined(HAVE_SCTP)
+    else if (protocol == IPPROTO_SCTP)
+        cnt_dec(&data.numProtoSCTP, 1);
+#endif
+
+    MUNLOCK(data.cntMtx);
+}
+
+
+/* Increment counters for when a socket is opened
+ */
+static
+void inc_socket(int domain, int type, int protocol)
+{
+    MLOCK(data.cntMtx);
+
+    cnt_inc(&data.numSockets, 1);
+    
+    /* *** Domain counter *** */
+    if (domain == AF_INET)
+        cnt_inc(&data.numDomainInet, 1);
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    else if (domain == AF_INET6)
+        cnt_inc(&data.numDomainInet6, 1);
+#endif
+#if defined(HAVE_SYS_UN_H)
+    else if (domain == AF_UNIX)
+        cnt_inc(&data.numDomainInet6, 1);
+#endif
+
+    /* *** Type counter *** */
+    if (type == SOCK_STREAM)
+        cnt_inc(&data.numTypeStreams, 1);
+    else if (type == SOCK_DGRAM)
+        cnt_inc(&data.numTypeDGrams, 1);
+#ifdef HAVE_SCTP
+    else if (type == SOCK_SEQPACKET)
+        cnt_inc(&data.numTypeSeqPkgs, 1);
+#endif
+
+    /* *** Protocol counter *** */
+    if (protocol == IPPROTO_IP)
+        cnt_inc(&data.numProtoIP, 1);
+    else if (protocol == IPPROTO_TCP)
+        cnt_inc(&data.numProtoTCP, 1);
+    else if (protocol == IPPROTO_UDP)
+        cnt_inc(&data.numProtoUDP, 1);
+#if defined(HAVE_SCTP)
+    else if (protocol == IPPROTO_SCTP)
+        cnt_inc(&data.numProtoSCTP, 1);
+#endif
+
+    MUNLOCK(data.cntMtx);
+}
+
+
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  D e c o d e / E n c o d e   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* edomain2domain - convert internal (erlang) domain to (proper) domain
+ *
+ * Note that only a subset is supported.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T edomain2domain(int edomain, int* domain)
+{
+    switch (edomain) {
+    case ESOCK_DOMAIN_INET:
+        *domain = AF_INET;
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case ESOCK_DOMAIN_INET6:
+        *domain = AF_INET6;
+        break;
+#endif
+#ifdef HAVE_SYS_UN_H
+    case ESOCK_DOMAIN_LOCAL:
+        *domain = AF_UNIX;
+        break;
+#endif
+
+    default:
+        *domain = -1;
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+
+/* etype2type - convert internal (erlang) type to (proper) type
+ *
+ * Note that only a subset is supported.
+ */
+static
+BOOLEAN_T etype2type(int etype, int* type)
+{
+    switch (etype) {
+    case ESOCK_TYPE_STREAM:
+        *type = SOCK_STREAM;
+        break;
+
+    case ESOCK_TYPE_DGRAM:
+        *type = SOCK_DGRAM;
+        break;
+
+    case ESOCK_TYPE_RAW:
+        *type = SOCK_RAW;
+        break;
+
+#ifdef HAVE_SCTP    
+    case ESOCK_TYPE_SEQPACKET:
+        *type = SOCK_SEQPACKET;
+        break;
+#endif
+
+    default:
+        *type = -1;
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+
+/* eproto2proto - convert internal (erlang) protocol to (proper) protocol
+ *
+ * Note that only a subset is supported.
+ */
+static
+BOOLEAN_T eproto2proto(ErlNifEnv*   env,
+                       ERL_NIF_TERM eproto,
+                       int*         proto)
+{
+    if (IS_NUM(env, eproto)) {
+        int ep;
+
+        if (!GET_INT(env, eproto, &ep)) {
+            *proto = -1;
+            return FALSE;
+        }
+
+        switch (ep) {
+        case ESOCK_PROTOCOL_DEFAULT:
+            *proto = 0; // default - note that _IP also has the value 0...
+            break;
+            
+        case ESOCK_PROTOCOL_IP:
+            *proto = IPPROTO_IP;
+            break;
+            
+        case ESOCK_PROTOCOL_TCP:
+            *proto = IPPROTO_TCP;
+            break;
+            
+        case ESOCK_PROTOCOL_UDP:
+            *proto = IPPROTO_UDP;
+            break;
+            
+#if defined(HAVE_SCTP)
+        case ESOCK_PROTOCOL_SCTP:
+            *proto = IPPROTO_SCTP;
+            break;
+#endif
+            
+        case ESOCK_PROTOCOL_ICMP:
+            *proto = IPPROTO_ICMP;
+            break;
+            
+        case ESOCK_PROTOCOL_IGMP:
+            *proto = IPPROTO_IGMP;
+            break;
+            
+        default:
+            *proto = -2;
+            return FALSE;
+        }
+    } else {
+        const ERL_NIF_TERM* a;
+        int                 sz;
+
+        if (!GET_TUPLE(env, eproto, &sz, &a)) {
+            *proto = -3;
+            return FALSE;
+        }
+        
+        if (sz != 2) {
+            *proto = -4;
+            return FALSE;
+        }
+
+        if (COMPARE(a[0], esock_atom_raw) != 0) {
+            *proto = -5;
+            return FALSE;
+        }
+
+        if (!GET_INT(env, a[1], proto)) {
+            *proto = -6;
+            return FALSE;
+        }
+    }
+
+    return TRUE;
+}
+
+
+#ifdef HAVE_SETNS
+ /* emap2netns - extract the netns field from the extra map
+ *
+ * Note that currently we only support one extra option, the netns.
+ */
+static
+BOOLEAN_T emap2netns(ErlNifEnv* env, ERL_NIF_TERM map, char** netns)
+{
+    size_t       sz;
+    ERL_NIF_TERM key;
+    ERL_NIF_TERM value;
+    unsigned int len;
+    char*        buf;
+    int          written;
+
+    /* Note that its acceptable that the extra map is empty */
+    if (!enif_get_map_size(env, map, &sz) ||
+        (sz != 1)) {
+        *netns = NULL;
+        return TRUE;
+    }
+
+    /* The currently only supported extra option is:  netns */
+    key = enif_make_atom(env, "netns");
+    if (!GET_MAP_VAL(env, map, key, &value)) {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+
+    /* So far so good. The value should be a string, check. */
+    if (!enif_is_list(env, value)) {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+
+    if (!enif_get_list_length(env, value, &len)) {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+
+    if ((buf = MALLOC(len+1)) == NULL) {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+
+    written = enif_get_string(env, value, buf, len+1, ERL_NIF_LATIN1);
+    if (written == (len+1)) {
+        *netns = buf;
+        return TRUE;
+    } else {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+}
+#endif
+
+
+/* esendflags2sendflags - convert internal (erlang) send flags to (proper)
+ * send flags.
+ */
+static
+BOOLEAN_T esendflags2sendflags(unsigned int eflags, int* flags)
+{
+    unsigned int ef;
+    int          tmp = 0;
+
+    /* First, check if we have any flags at all */
+    if (eflags == 0) {
+        *flags = 0;
+        return TRUE;
+    }
+        
+    for (ef = ESOCK_SEND_FLAG_LOW; ef <= ESOCK_SEND_FLAG_HIGH; ef++) {
+
+        switch (ef) {
+#if defined(MSG_CONFIRM)
+        case ESOCK_SEND_FLAG_CONFIRM:
+            if ((1 << ESOCK_SEND_FLAG_CONFIRM) & eflags)
+                tmp |= MSG_CONFIRM;
+            break;
+#endif
+
+#if defined(MSG_DONTROUTE)
+        case ESOCK_SEND_FLAG_DONTROUTE:
+            if ((1 << ESOCK_SEND_FLAG_DONTROUTE) & eflags)
+                tmp |= MSG_DONTROUTE;
+            break;
+#endif
+
+#if defined(MSG_EOR)
+        case ESOCK_SEND_FLAG_EOR:
+            if ((1 << ESOCK_SEND_FLAG_EOR) & eflags)
+                tmp |= MSG_EOR;
+            break;
+#endif
+
+#if defined(MSG_MORE)
+        case ESOCK_SEND_FLAG_MORE:
+            if ((1 << ESOCK_SEND_FLAG_MORE) & eflags)
+                tmp |= MSG_MORE;
+            break;
+#endif
+
+#if defined(MSG_NOSIGNAL)
+        case ESOCK_SEND_FLAG_NOSIGNAL:
+            if ((1 << ESOCK_SEND_FLAG_NOSIGNAL) & eflags)
+                tmp |= MSG_NOSIGNAL;
+            break;
+#endif
+
+#if defined(MSG_OOB)
+        case ESOCK_SEND_FLAG_OOB:
+            if ((1 << ESOCK_SEND_FLAG_OOB) & eflags)
+                tmp |= MSG_OOB;
+            break;
+#endif
+
+        default:
+            return FALSE;
+        }
+
+    }
+
+    *flags = tmp;
+
+    return TRUE;
+}
+
+
+
+/* erecvflags2recvflags - convert internal (erlang) send flags to (proper)
+ * send flags.
+ */
+static
+BOOLEAN_T erecvflags2recvflags(unsigned int eflags, int* flags)
+{
+    unsigned int ef;
+    int          tmp = 0;
+
+    SGDBG( ("SOCKET", "erecvflags2recvflags -> entry with"
+            "\r\n   eflags: %d"
+            "\r\n", eflags) );
+
+    if (eflags == 0) {
+        *flags = 0;
+        return TRUE;
+    }
+
+    for (ef = ESOCK_RECV_FLAG_LOW; ef <= ESOCK_RECV_FLAG_HIGH; ef++) {
+
+        SGDBG( ("SOCKET", "erecvflags2recvflags -> iteration"
+                "\r\n   ef:  %d"
+                "\r\n   tmp: %d"
+                "\r\n", ef, tmp) );
+
+        switch (ef) {
+#if defined(MSG_CMSG_CLOEXEC)
+        case ESOCK_RECV_FLAG_CMSG_CLOEXEC:
+            if ((1 << ESOCK_RECV_FLAG_CMSG_CLOEXEC) & eflags)
+                tmp |= MSG_CMSG_CLOEXEC;
+            break;
+#endif
+
+#if defined(MSG_ERRQUEUE)
+        case ESOCK_RECV_FLAG_ERRQUEUE:
+            if ((1 << ESOCK_RECV_FLAG_ERRQUEUE) & eflags)
+                tmp |= MSG_ERRQUEUE;
+            break;
+#endif
+
+#if defined(MSG_OOB)
+        case ESOCK_RECV_FLAG_OOB:
+            if ((1 << ESOCK_RECV_FLAG_OOB) & eflags)
+                tmp |= MSG_OOB;
+            break;
+#endif
+
+            /*
+             * <KOLLA>
+             *
+             * We need to handle this, because it may effect the read algorithm
+             *
+             * </KOLLA>
+             */
+#if defined(MSG_PEEK)
+        case ESOCK_RECV_FLAG_PEEK:
+            if ((1 << ESOCK_RECV_FLAG_PEEK) & eflags)
+                tmp |= MSG_PEEK;
+            break;
+#endif
+
+#if defined(MSG_TRUNC)
+        case ESOCK_RECV_FLAG_TRUNC:
+            if ((1 << ESOCK_RECV_FLAG_TRUNC) & eflags)
+                tmp |= MSG_TRUNC;
+            break;
+#endif
+
+        default:
+            return FALSE;
+        }
+
+    }
+
+    *flags = tmp;
+
+    return TRUE;
+}
+
+
+
+/* eproto2proto - convert internal (erlang) protocol to (proper) protocol
+ *
+ * Note that only a subset is supported.
+ */
+static
+BOOLEAN_T ehow2how(unsigned int ehow, int* how)
+{
+     switch (ehow) {
+     case ESOCK_SHUTDOWN_HOW_RD:
+         *how = SHUT_RD;
+         break;
+
+     case ESOCK_SHUTDOWN_HOW_WR:
+         *how = SHUT_WR;
+         break;
+
+     case ESOCK_SHUTDOWN_HOW_RDWR:
+         *how = SHUT_RDWR;
+         break;
+
+     default:
+         return FALSE;
+     }
+
+     return TRUE;
+}
+
+
+
+/* ecommand2command - convert erlang command to "native" command (and data)
+ */
+static
+BOOLEAN_T ecommand2command(ErlNifEnv*    env,
+                           ERL_NIF_TERM  ecommand,
+                           Uint16*       command,
+                           ERL_NIF_TERM* edata)
+{
+    size_t       sz;
+    ERL_NIF_TERM ecmd;
+
+    if (!IS_MAP(env, ecommand)) {
+        SGDBG( ("SOCKET", "ecommand2command -> (e)command not a map\r\n") );
+        return FALSE;
+    }
+
+    /* The map shall have exactly two attrbutes: 
+     *          'command' and 'data'
+     */
+    if (!enif_get_map_size(env, ecommand, &sz) || (sz != 2)) {
+        SGDBG( ("SOCKET", "ecommand2command -> comamnd map size invalid\r\n") );
+        return FALSE;
+    }
+
+    /* Get the command value, and transform into integer
+     * (might as well do that, since theer is no point in
+     *  extracting the data if command is invalid).
+     */
+    if (!GET_MAP_VAL(env, ecommand, esock_atom_command, &ecmd)) {
+        SGDBG( ("SOCKET", "ecommand2command -> command attribute not found\r\n") );
+        return FALSE;
+    }
+    if (COMPARE(ecmd, esock_atom_debug) == 0) {
+        *command = ESOCK_CMD_DEBUG;
+    } else {
+        SGDBG( ("SOCKET", "ecommand2command -> unknown command %T\r\n", ecmd) );
+        return FALSE;
+    }
+
+    /* Get the command data value, we do *not* convert it to 
+     * the native form (here) since it may "in theory" be complex.
+     */
+    if (!GET_MAP_VAL(env, ecommand, esock_atom_data, edata)) {
+        SGDBG( ("SOCKET", "ecommand2command -> (command) data not found\r\n") );
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+
+
+
+#if defined(HAVE_SYS_UN_H) || defined(SO_BINDTODEVICE)
+/* strnlen doesn't exist everywhere */
+/*
+static
+size_t my_strnlen(const char *s, size_t maxlen)
+{
+    size_t i = 0;
+    while (i < maxlen && s[i] != '\0')
+        i++;
+    return i;
+}
+*/
+#endif
+
+
+/* Send an counter wrap message to the controlling process:
+ * A message in the form:
+ *
+ *     {'$socket', Socket, counter_wrap, Counter :: atom()}
+ *
+ * This message will only be sent if the iow (Inform On Wrap) is TRUE.
+ */
+static
+char* esock_send_wrap_msg(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          ERL_NIF_TERM     sockRef,
+                          ERL_NIF_TERM     cnt)
+{
+    ERL_NIF_TERM msg = mk_wrap_msg(env, sockRef, cnt);
+    
+    return esock_send_msg(env, &descP->ctrlPid, msg, NULL);
+}
+
+
+/* Send an close message to the specified process:
+ * A message in the form:
+ *
+ *     {'$socket', Socket, close, CloseRef}
+ *
+ * This message is for processes that is waiting in the
+ * erlang API (close-) function for the socket to be "closed"
+ * (actually that the 'stop' callback function has been called).
+ */
+static
+char* esock_send_close_msg(ErlNifEnv*       env,
+                           ESockDescriptor* descP,
+                           ErlNifPid*       pid)
+{
+    ERL_NIF_TERM sockRef, msg;
+    ErlNifEnv*   menv;
+    
+    if (descP->closeEnv != NULL) {
+        sockRef = enif_make_resource(descP->closeEnv, descP);
+        msg     = mk_close_msg(descP->closeEnv, sockRef, descP->closeRef);
+        menv    = descP->closeEnv;
+    } else {
+        sockRef = enif_make_resource(env, descP);
+        msg     = mk_close_msg(env, sockRef, descP->closeRef);
+        menv    = NULL; // This has the effect that the message will be copied
+    }
+    
+    return esock_send_msg(env, pid, msg, menv);
+}
+
+
+/* Send an abort message to the specified process:
+ * A message in the form:
+ *
+ *     {'$socket', Socket, abort, {RecvRef, Reason}}
+ *
+ * This message is for processes that is waiting in the
+ * erlang API functions for a select message.
+ */
+static
+char* esock_send_abort_msg(ErlNifEnv*   env,
+                           ERL_NIF_TERM sockRef,
+                           ERL_NIF_TERM opRef,
+                           ErlNifEnv*   msgEnv,
+                           ERL_NIF_TERM reason,
+                           ErlNifPid*   pid)
+{
+    ERL_NIF_TERM msg = mk_abort_msg(msgEnv,
+                                    /* sockRef not in msgEnv so copy */
+                                    CP_TERM(msgEnv, sockRef),
+                                    opRef, reason);
+
+    return esock_send_msg(env, pid, msg, msgEnv);
+}
+
+
+/* Send a message to the specified process.
+ */
+static
+char* esock_send_msg(ErlNifEnv*   env,
+                     ErlNifPid*   pid,
+                     ERL_NIF_TERM msg,
+                     ErlNifEnv*   msgEnv)
+{
+    int res = enif_send(env, pid, msgEnv, msg);
+    if (msgEnv)
+        esock_free_env("esock_msg_send - msg-env", msgEnv);
+
+    if (!res)
+        return str_exsend;
+    else
+        return NULL;
+}
+
+
+
+/* *** mk_abort_msg ***
+ *
+ * Create the abort message, which has the following form:
+ *
+ *     {'$socket', Socket, abort, {OpRef, Reason}}
+ *
+ * This message is for processes that are waiting in the
+ * erlang API functions for a select (or this) message.
+ */
+static
+ERL_NIF_TERM mk_abort_msg(ErlNifEnv*   env,
+                          ERL_NIF_TERM sockRef,
+                          ERL_NIF_TERM opRef,
+                          ERL_NIF_TERM reason)
+{
+    ERL_NIF_TERM info = MKT2(env, opRef, reason);
+    
+    return mk_socket_msg(env, sockRef, esock_atom_abort, info);
+}
+
+
+/* *** mk_wrap_msg ***
+ *
+ * Construct a counter wrap (socket) message. It has the form: 
+ *
+ *         {'$socket', Socket, counter_wrap, Counter}
+ *
+ */
+static
+ERL_NIF_TERM mk_wrap_msg(ErlNifEnv*   env,
+                         ERL_NIF_TERM sockRef,
+                         ERL_NIF_TERM cnt)
+{
+    return mk_socket_msg(env, sockRef, atom_counter_wrap, cnt);
+}
+
+
+/* *** mk_close_msg ***
+ *
+ * Construct a close (socket) message. It has the form: 
+ *
+ *         {'$socket', Socket, close, closeRef}
+ *
+ */
+static
+ERL_NIF_TERM mk_close_msg(ErlNifEnv*   env,
+                          ERL_NIF_TERM sockRef,
+                          ERL_NIF_TERM closeRef)
+{
+    return mk_socket_msg(env, sockRef, esock_atom_close, closeRef);
+}
+
+
+/* *** mk_select_msg ***
+ *
+ * Construct a select (socket) message. It has the form: 
+ *
+ *         {'$socket', Socket, select, selectRef}
+ *
+ */
+static
+ERL_NIF_TERM mk_select_msg(ErlNifEnv*   env,
+                           ERL_NIF_TERM sockRef,
+                           ERL_NIF_TERM selectRef)
+{
+    return mk_socket_msg(env, sockRef, atom_select, selectRef);
+}
+
+
+/* *** mk_socket_msg ***
+ *
+ * Construct the socket message:
+ *
+ *         {'$socket', Socket, Tag, Info}
+ *
+ * Socket :: socket() (#socket{})
+ * Tag    :: atom()
+ * Info   :: term()
+ *
+ */
+static
+ERL_NIF_TERM mk_socket_msg(ErlNifEnv*   env,
+                           ERL_NIF_TERM sockRef,
+                           ERL_NIF_TERM tag,
+                           ERL_NIF_TERM info)
+{
+    ERL_NIF_TERM socket = mk_socket(env, sockRef);
+
+    return MKT4(env, esock_atom_socket_tag, socket, tag, info);
+}
+
+
+/* *** mk_socket ***
+ *
+ * Simple utility function that construct the socket resord:
+ *
+ *      #socket{ref = SockRef} => {socket, SockRef :: reference()}
+ */
+static
+ERL_NIF_TERM mk_socket(ErlNifEnv*   env,
+                       ERL_NIF_TERM sockRef)
+{
+    return MKT2(env, esock_atom_socket, sockRef);
+}
+
+#endif // #if defined(__WIN32__)
+
+                              
+/* ----------------------------------------------------------------------
+ *  S e l e c t   W r a p p e r   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* *** esock_select_read ***
+ *
+ * Perform a read select. When the select is triggered, a 'select'
+ * message (see mk_select_msg) will be sent.
+ *
+ * There are two ways to handle the select message:
+ * 1) Create "your own" environment and create the message using it
+ *    and then pass it on to the select function.
+ * 2) Or, to create the message using any available environment,
+ *    and then pass a NULL pointer to the select function.
+ *    This will have the effect that the select function will 
+ *    create its own environment and then copy the message to it.
+ * We choose the second alternative.
+ */
+static
+int esock_select_read(ErlNifEnv*       env,
+                      ErlNifEvent      event,     // The file descriptor
+                      void*            obj,       // The socket descriptor object
+                      const ErlNifPid* pid,       // Destination
+                      ERL_NIF_TERM     sockRef,   // Socket
+                      ERL_NIF_TERM     selectRef) // "ID" of the operation
+{
+    ERL_NIF_TERM selectMsg = mk_select_msg(env, sockRef, selectRef);
+
+    return enif_select_read(env, event, obj, pid, selectMsg, NULL);
+
+}
+
+
+/* *** esock_select_write ***
+ *
+ * Perform a write select. When the select is triggered, a 'select'
+ * message (see mk_select_msg) will be sent.
+ * The sockRef is copied to the msgEnv when the socket message is created,
+ * so no need to do that here, but the selectRef needs to be copied.
+ */
+static
+int esock_select_write(ErlNifEnv*       env,
+                       ErlNifEvent      event,     // The file descriptor
+                       void*            obj,       // The socket descriptor
+                       const ErlNifPid* pid,       // Destination
+                       ERL_NIF_TERM     sockRef,   // Socket
+                       ERL_NIF_TERM     selectRef) // "ID" of the operation
+{
+    ERL_NIF_TERM selectMsg = mk_select_msg(env, sockRef, selectRef);
+
+    return enif_select_write(env, event, obj, pid, selectMsg, NULL);
+}
+
+
+static
+int esock_select_stop(ErlNifEnv*  env,
+                      ErlNifEvent event,
+                      void*       obj)
+{
+    return enif_select(env, event, (ERL_NIF_SELECT_STOP), obj, NULL,
+                       esock_atom_undefined);
+}
+
+static
+int esock_select_cancel(ErlNifEnv*             env,
+                        ErlNifEvent            event,
+                        enum ErlNifSelectFlags mode,
+                        void*                  obj)
+{
+    return enif_select(env, event, (ERL_NIF_SELECT_CANCEL | mode), obj, NULL,
+                       esock_atom_undefined);
+}
+
+
+/* ----------------------------------------------------------------------
+ *  A c t i v a t e   N e x t   ( o p e r a t o r )   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* *** activate_next_acceptor ***
+ * *** activate_next_writer   ***
+ * *** activate_next_reader   ***
+ *
+ * This functions pops the requestors queue and then selects until it 
+ * manages to successfully activate a requestor or the queue is empty.
+ * Return value indicates if a new requestor was activated or not.
+ */
+
+#if !defined(__WIN32__)
+
+#define ACTIVATE_NEXT_FUNCS                                               \
+    ACTIVATE_NEXT_FUNC_DECL(acceptor, read,  currentAcceptor, acceptorsQ) \
+    ACTIVATE_NEXT_FUNC_DECL(writer,   write, currentWriter,   writersQ)   \
+    ACTIVATE_NEXT_FUNC_DECL(reader,   read,  currentReader,   readersQ)
+
+#define ACTIVATE_NEXT_FUNC_DECL(F, S, R, Q)                  \
+    static                                                   \
+    BOOLEAN_T activate_next_##F(ErlNifEnv*       env,        \
+                                ESockDescriptor* descP,      \
+                                ERL_NIF_TERM     sockRef)    \
+    {                                                        \
+        BOOLEAN_T          popped, activated;                \
+        int                sres;                             \
+        ERL_NIF_TERM       reason;                           \
+        ESockRequestor*    reqP = &descP->R;                 \
+        ESockRequestQueue* q    = &descP->Q;                 \
+                                                             \
+        popped = FALSE;                                      \
+        do {                                                 \
+                                                             \
+            if (requestor_pop(q, reqP)) {                    \
+                                                             \
+                /* There was another one */                  \
+                                                             \
+                SSDBG( descP,                                \
+                       ("SOCKET",                                       \
+                        "activate_next_" #F " -> new (active) requestor: " \
+                        "\r\n   pid: %T"                                \
+                        "\r\n   ref: %T"                                \
+                        "\r\n", reqP->pid, reqP->ref) );                \
+                                                                        \
+                /* We need to copy req ref to 'env' */                  \
+                if ((sres = esock_select_##S(env, descP->sock, descP,   \
+                                             &reqP->pid, sockRef,       \
+                                             CP_TERM(env, reqP->ref))) < 0) { \
+                                                                        \
+                    /* We need to inform this process, reqP->pid,  */   \
+                    /* that we failed to select, so we don't leave */   \
+                    /* it hanging.                                 */   \
+                    /* => send abort                               */   \
+                                                                        \
+                    reason = MKT2(env,                                  \
+                                  esock_atom_select_failed,             \
+                                  MKI(env, sres));                      \
+                    esock_send_abort_msg(env, sockRef,                  \
+                                         reqP->ref, reqP->env,          \
+                                         reason, &reqP->pid);           \
+                    reqP->env = NULL;                                  \
+                                                                        \
+                } else {                                                \
+                                                                        \
+                    /* Success: New requestor selected */               \
+                    popped    = TRUE;                                   \
+                    activated = FALSE;                                  \
+                                                                        \
+                }                                                       \
+                                                                        \
+            } else {                                                    \
+                                                                        \
+                SSDBG( descP,                                           \
+                       ("SOCKET",                                       \
+                        "activate_next_" #F " -> no more requestors\r\n") ); \
+                                                                        \
+                popped    = TRUE;                                       \
+                activated = FALSE;                                      \
+            }                                                           \
+                                                                        \
+        } while (!popped);                                              \
+                                                                        \
+        SSDBG( descP,                                                   \
+               ("SOCKET", "activate_next_" #F " -> "                    \
+                "done with %s\r\n", B2S(activated)) );                  \
+                                                                        \
+        return activated;                                               \
+    }
+ACTIVATE_NEXT_FUNCS
+#undef ACTIVATE_NEXT_FUNC_DECL
+
+
+#endif // if !defined(__WIN32__)
+
+
+/* ----------------------------------------------------------------------
+ *  R e q u e s t o r   Q u e u e   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ *
+ * Since each of these functions (search4pid, push, pop and unqueue
+ * are virtually identical for acceptors, writers and readers, 
+ * we make use of set of declaration macros.
+ */
+
+#if !defined(__WIN32__)
+
+/* *** acceptor_search4pid ***
+ * *** writer_search4pid   ***
+ * *** reader_search4pid   ***
+ *
+ * Search for a pid in the requestor (acceptor, writer, or reader) queue.
+ *
+ */
+
+#define REQ_SEARCH4PID_FUNCS                       \
+    REQ_SEARCH4PID_FUNC_DECL(acceptor, acceptorsQ) \
+    REQ_SEARCH4PID_FUNC_DECL(writer,   writersQ)   \
+    REQ_SEARCH4PID_FUNC_DECL(reader,   readersQ)
+
+#define REQ_SEARCH4PID_FUNC_DECL(F, Q)                 \
+    static                                             \
+    BOOLEAN_T F##_search4pid(ErlNifEnv*       env,     \
+                             ESockDescriptor* descP,   \
+                             ErlNifPid*       pid)     \
+    {                                                  \
+        return qsearch4pid(env, &descP->Q, pid);       \
+    }
+REQ_SEARCH4PID_FUNCS
+#undef REQ_SEARCH4PID_FUNC_DECL
+
+
+
+/* *** acceptor_push ***
+ * *** writer_push   ***
+ * *** reader_push   ***
+ *
+ * Push a requestor (acceptor, writer, or reader) onto its queue.
+ * This happens when we already have a current request (of its type).
+ *
+ */
+
+#define REQ_PUSH_FUNCS                       \
+    REQ_PUSH_FUNC_DECL(acceptor, acceptorsQ) \
+    REQ_PUSH_FUNC_DECL(writer,   writersQ)   \
+    REQ_PUSH_FUNC_DECL(reader,   readersQ)
+
+#define REQ_PUSH_FUNC_DECL(F, Q)                                       \
+    static                                                             \
+    ERL_NIF_TERM F##_push(ErlNifEnv*       env,                        \
+                          ESockDescriptor* descP,                      \
+                          ErlNifPid        pid,                        \
+                          ERL_NIF_TERM     ref)                        \
+    {                                                                  \
+        ESockRequestQueueElement* e    = MALLOC(sizeof(ESockRequestQueueElement)); \
+        ESockRequestor*           reqP = &e->data;                     \
+                                                                       \
+        reqP->pid = pid;                                               \
+        if (MONP("reader_push -> " #F " request",                      \
+                 env, descP, &pid, &reqP->mon) != 0) {                 \
+            FREE(e);                                                   \
+            return esock_make_error(env, atom_exmon);                  \
+        }                                                              \
+        reqP->env = esock_alloc_env(#F "_push");                                  \
+        reqP->ref = enif_make_copy(reqP->env, ref);                    \
+                                                                       \
+        qpush(&descP->Q, e);                                           \
+                                                                       \
+        return esock_make_error(env, esock_atom_eagain);               \
+    }
+REQ_PUSH_FUNCS
+#undef REQ_PUSH_FUNC_DECL
+
+
+
+/* *** acceptor_pop ***
+ * *** writer_pop   ***
+ * *** reader_pop   ***
+ *
+ * Pop a requestor (acceptor, writer, or reader) from its queue.
+ *
+ */
+#define REQ_POP_FUNCS                       \
+    REQ_POP_FUNC_DECL(acceptor, acceptorsQ) \
+    REQ_POP_FUNC_DECL(writer,   writersQ)   \
+    REQ_POP_FUNC_DECL(reader,   readersQ)
+
+#define REQ_POP_FUNC_DECL(F, Q)                \
+    static                                     \
+    BOOLEAN_T F##_pop(ErlNifEnv*       env,    \
+                      ESockDescriptor* descP,  \
+                      ESockRequestor*  reqP)   \
+    {                                          \
+        return requestor_pop(&descP->Q, reqP); \
+    }
+REQ_POP_FUNCS
+#undef REQ_POP_FUNC_DECL
+
+
+
+/* *** acceptor_unqueue ***
+ * *** writer_unqueue   ***
+ * *** reader_unqueue   ***
+ *
+ * Remove a requestor (acceptor, writer, or reader) from its queue.
+ *
+ */
+
+#define REQ_UNQUEUE_FUNCS                       \
+    REQ_UNQUEUE_FUNC_DECL(acceptor, acceptorsQ) \
+    REQ_UNQUEUE_FUNC_DECL(writer,   writersQ)   \
+    REQ_UNQUEUE_FUNC_DECL(reader,   readersQ)
+
+#define REQ_UNQUEUE_FUNC_DECL(F, Q)                            \
+    static                                                     \
+    BOOLEAN_T F##_unqueue(ErlNifEnv*       env,                \
+                          ESockDescriptor* descP,              \
+                          const ErlNifPid* pid)                \
+    {                                                          \
+        return qunqueue(env, descP, "qunqueue -> waiting " #F, \
+                        &descP->Q, pid);                       \
+    }
+REQ_UNQUEUE_FUNCS
+#undef REQ_UNQUEUE_FUNC_DECL
+
+
+
+/* *** requestor pop ***
+ *
+ * Pop an requestor from its queue.
+ */
+static
+BOOLEAN_T requestor_pop(ESockRequestQueue* q,
+                        ESockRequestor*    reqP)
+{
+    ESockRequestQueueElement* e = qpop(q);
+
+    if (reqP->env)
+        esock_free_env("requestor_pop", reqP->env);
+
+    if (e != NULL) {
+        reqP->pid = e->data.pid;
+        reqP->mon = e->data.mon;
+        reqP->env = e->data.env;
+        reqP->ref = e->data.ref;
+        FREE(e);
+        return TRUE;
+    } else {
+        /* Queue was empty */
+        enif_set_pid_undefined(&reqP->pid);
+        MON_INIT(&reqP->mon);
+        reqP->env = NULL;
+        reqP->ref = esock_atom_undefined; // Just in case
+        return FALSE;
+    }
+    
+}
+
+
+static
+BOOLEAN_T qsearch4pid(ErlNifEnv*         env,
+                      ESockRequestQueue* q,
+                      ErlNifPid*         pid)
+{
+    ESockRequestQueueElement* tmp = q->first;
+    
+    while (tmp != NULL) {
+        if (COMPARE_PIDS(&tmp->data.pid, pid) == 0)
+            return TRUE;
+        else
+            tmp = tmp->nextP;
+    }
+
+    return FALSE;
+}
+
+
+static
+void qpush(ESockRequestQueue*        q,
+           ESockRequestQueueElement* e)
+{
+    if (q->first != NULL) {
+        q->last->nextP = e;
+        q->last        = e;
+        e->nextP       = NULL;
+    } else {
+        q->first = e;
+        q->last  = e;
+        e->nextP = NULL;
+    }
+}
+ 
+ 
+static
+ESockRequestQueueElement* qpop(ESockRequestQueue* q)
+{
+    ESockRequestQueueElement* e = q->first;
+    
+    if (e != NULL) {
+        /* Atleast one element in the queue */
+        if (e == q->last) {
+            /* Only one element in the queue */
+            q->first = q->last = NULL;
+        } else {
+            /* More than one element in the queue */
+            q->first = e->nextP;
+        }
+    }
+    
+    return e;
+}
+
+
+
+static
+BOOLEAN_T qunqueue(ErlNifEnv*         env,
+                   ESockDescriptor*   descP,
+                   const char*        slogan,
+                   ESockRequestQueue* q,
+                   const ErlNifPid*   pid)
+{
+    ESockRequestQueueElement* e = q->first;
+    ESockRequestQueueElement* p = NULL;
+
+    /* Check if it was one of the waiting acceptor processes */
+    while (e != NULL) {
+        if (COMPARE_PIDS(&e->data.pid, pid) == 0) {
+
+            /* We have a match */
+
+            DEMONP(slogan, env, descP, &e->data.mon);
+            
+            if (p != NULL) {
+                /* Not the first, but could be the last */
+                if (q->last == e) {
+                    q->last  = p;
+                    p->nextP = NULL;                    
+                } else {
+                    p->nextP = e->nextP;
+                }
+                    
+            } else {
+                /* The first and could also be the last */
+                if (q->last == e) {
+                    q->last  = NULL;
+                    q->first = NULL;
+                } else {
+                    q->first = e->nextP;
+                }
+            }
+
+            if (e->data.env)
+                esock_free_env("qunqueue", e->data.env);
+            FREE(e);
+
+            return TRUE;
+        }
+
+        /* Try next */
+        p = e;
+        e = e->nextP;
+    }
+
+    return FALSE;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  C o u n t e r   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+#if !defined(__WIN32__)
+static
+BOOLEAN_T cnt_inc(Uint32* cnt, Uint32 inc)
+{
+    BOOLEAN_T wrap;
+    Uint32    max     = 0xFFFFFFFF;
+    Uint32    current = *cnt;
+
+    if ((max - inc) >= current) {
+        *cnt += inc;
+        wrap  = FALSE;
+    } else {
+        *cnt = inc - (max - current) - 1;
+        wrap = TRUE;
+    }
+
+    return (wrap);
+}
+
+
+static
+void cnt_dec(Uint32* cnt, Uint32 dec)
+{
+    Uint32 current = *cnt;
+
+    if (dec > current)
+        *cnt = 0; // The counter cannot be < 0 so this is the best we can do...
+    else
+        *cnt -= dec;
+
+    return;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+
+/* ----------------------------------------------------------------------
+ *  M o n i t o r   W r a p p e r   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+#if !defined(__WIN32__)
+
+static
+int esock_monitor(const char*      slogan,
+                  ErlNifEnv*       env,
+                  ESockDescriptor* descP,
+                  const ErlNifPid* pid,
+                  ESockMonitor*    monP)
+{
+    int res;
+
+    SSDBG( descP, ("SOCKET", "[%d] %s: try monitor\r\n", descP->sock, slogan) );
+    res = enif_monitor_process(env, descP, pid, &monP->mon);
+
+    if (res != 0) {
+        monP->isActive = FALSE;
+        SSDBG( descP, ("SOCKET", "[%d] monitor failed: %d\r\n", descP->sock, res) );
+    } else {
+        monP->isActive = TRUE;
+    }
+
+    return res;
+}
+
+
+static
+int esock_demonitor(const char*      slogan,
+                    ErlNifEnv*       env,
+                    ESockDescriptor* descP,
+                    ESockMonitor*    monP)
+{
+    int res;
+
+    if (!monP->isActive)
+        return 1;
+
+    SSDBG( descP, ("SOCKET", "[%d] %s: try demonitor\r\n", descP->sock, slogan) );
+
+    res = enif_demonitor_process(env, descP, &monP->mon);
+
+    if (res == 0) {
+        esock_monitor_init(monP);
+    } else {
+        SSDBG( descP,
+               ("SOCKET", "[%d] demonitor failed: %d\r\n", descP->sock, res) );
+    }
+
+    return res;
+}
+
+
+static
+void esock_monitor_init(ESockMonitor* monP)
+{
+    monP->isActive = FALSE;
+}
+
+
+static
+ERL_NIF_TERM esock_make_monitor_term(ErlNifEnv* env, const ESockMonitor* monP)
+{
+    if (monP->isActive)
+        return enif_make_monitor_term(env, &monP->mon);
+    else
+        return esock_atom_undefined;
+}
+
+
+
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  C a l l b a c k   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+
+static void free_request_queue(ESockRequestQueue* q)
+{
+    while (q->first) {
+        ESockRequestQueueElement* free_me = q->first;
+        q->first = free_me->nextP;
+        if (free_me->data.env)
+            esock_free_env("dtor", free_me->data.env);
+        FREE(free_me);
+    }
+}
+
+/* =========================================================================
+ * esock_dtor - Callback function for resource destructor
+ *
+ */
+static
+void esock_dtor(ErlNifEnv* env, void* obj)
+{
+#if !defined(__WIN32__)    
+  ESockDescriptor* descP = (ESockDescriptor*) obj;
+
+  MDESTROY(descP->writeMtx); descP->writeMtx = NULL;
+  MDESTROY(descP->readMtx);  descP->readMtx  = NULL;
+  MDESTROY(descP->accMtx);   descP->accMtx   = NULL;
+  MDESTROY(descP->closeMtx); descP->closeMtx = NULL;
+  MDESTROY(descP->cfgMtx);   descP->cfgMtx   = NULL;
+
+  if (descP->currentReader.env) {
+      esock_free_env("dtor reader", descP->currentReader.env);
+      descP->currentReader.env = NULL;
+  }
+  if (descP->currentWriter.env) {
+      esock_free_env("dtor writer", descP->currentWriter.env);
+      descP->currentWriter.env = NULL;
+  }
+  if (descP->currentAcceptor.env) {
+      esock_free_env("dtor acceptor", descP->currentAcceptor.env);
+      descP->currentAcceptor.env = NULL;
+  }
+  free_request_queue(&descP->readersQ);
+  free_request_queue(&descP->writersQ);
+  free_request_queue(&descP->acceptorsQ);
+
+  descP->state   = ESOCK_STATE_DTOR;
+  descP->pattern = ESOCK_DESC_PATTERN_DTOR;  
+#endif
+}
+
+
+/* =========================================================================
+ * esock_stop - Callback function for resource stop
+ *
+ * When the socket is stopped, we need to inform:
+ *
+ *     * the controlling process
+ *     * the current writer and any waiting writers
+ *     * the current reader and any waiting readers
+ *     * the current acceptor and any waiting acceptor
+ *
+ * Also, make sure no process gets the message twice
+ * (in case it is, for instance, both controlling process
+ * and a writer).
+ *
+ */
+static
+void esock_stop(ErlNifEnv* env, void* obj, int fd, int is_direct_call)
+{
+#if !defined(__WIN32__)
+    ESockDescriptor* descP = (ESockDescriptor*) obj;
+    ERL_NIF_TERM     sockRef;
+
+    SSDBG( descP,
+           ("SOCKET", "esock_stop -> entry when %s"
+            "\r\n   sock: %d (%d)"
+            "\r\n",
+            ((is_direct_call) ? "called" : "scheduled"), descP->sock, fd) );
+
+    /* +++ Lock it down +++ */
+    
+    MLOCK(descP->writeMtx);
+    MLOCK(descP->readMtx);
+    MLOCK(descP->accMtx);
+    MLOCK(descP->cfgMtx);
+    if (!is_direct_call) MLOCK(descP->closeMtx);
+    
+    SSDBG( descP, ("SOCKET", "esock_stop -> "
+                   "[%d, %T] all mutex(s) locked when counters:"
+                   "\r\n   writePkgCnt:  %u"
+                   "\r\n   writeByteCnt: %u"
+                   "\r\n   writeTries:   %u"
+                   "\r\n   writeWaits:   %u"
+                   "\r\n   writeFails:   %u"
+                   "\r\n   readPkgCnt:   %u"
+                   "\r\n   readByteCnt:  %u"
+                   "\r\n   readTries:    %u"
+                   "\r\n   readWaits:    %u"
+                   "\r\n",
+                   descP->sock, descP->ctrlPid,
+                   descP->writePkgCnt,
+                   descP->writeByteCnt,
+                   descP->writeTries,
+                   descP->writeWaits,
+                   descP->writeFails,
+                   descP->readPkgCnt,
+                   descP->readByteCnt,
+                   descP->readTries,
+                   descP->readWaits) );
+
+    sockRef           = enif_make_resource(env, descP);
+    descP->state      = ESOCK_STATE_CLOSING; // Just in case...???
+    descP->isReadable = FALSE;
+    descP->isWritable = FALSE;
+
+    /* We should check that we actually have a monitor.
+     * This *should* be done with a "NULL" monitor value,
+     * which there currently is none...
+     * If we got here because the controlling process died,
+     * there is no point to demonitor. Also, we do not actually
+     * have a monitor in that case...
+     */
+    DEMONP("esock_stop -> ctrl", env, descP, &descP->ctrlMon);
+
+
+
+    /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+     *
+     *           Check current and waiting Writers
+     *
+     * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+     */
+
+    if (descP->currentWriterP != NULL) {
+
+        /* We have a (current) writer and *may* therefor also have
+         * writers waiting.
+         */
+
+        esock_stop_handle_current(env,
+                                  "writer",
+                                  descP, sockRef, &descP->currentWriter);
+
+        /* And also deal with the waiting writers (in the same way) */
+        SSDBG( descP, ("SOCKET", "esock_stop -> handle waiting writer(s)\r\n") );
+        inform_waiting_procs(env, "writer",
+                             descP, sockRef, &descP->writersQ, TRUE, atom_closed);
+    }
+
+
+    /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+     *
+     *           Check current and waiting Readers
+     *
+     * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+     */
+
+    if (descP->currentReaderP != NULL) {
+        
+        /* We have a (current) reader and *may* therefor also have
+         * readers waiting.
+         */
+        
+        esock_stop_handle_current(env,
+                                  "reader",
+                                  descP, sockRef, &descP->currentReader);
+
+        /* And also deal with the waiting readers (in the same way) */
+        SSDBG( descP, ("SOCKET", "esock_stop -> handle waiting reader(s)\r\n") );
+        inform_waiting_procs(env, "reader",
+                             descP, sockRef, &descP->readersQ, TRUE, atom_closed);
+    }
+
+
+
+    /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+     *
+     *           Check current and waiting Acceptors
+     *
+     * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+     */
+
+    if (descP->currentAcceptorP != NULL) {
+
+        /* We have a (current) acceptor and *may* therefor also have
+         * acceptors waiting.
+         */
+
+        esock_stop_handle_current(env,
+                                  "acceptor",
+                                  descP, sockRef, &descP->currentAcceptor);
+        
+        /* And also deal with the waiting acceptors (in the same way) */
+        SSDBG( descP, ("SOCKET", "esock_stop -> handle waiting acceptor(s)\r\n") );
+        inform_waiting_procs(env, "acceptor",
+                             descP, sockRef, &descP->acceptorsQ, TRUE, atom_closed);
+    }
+    
+    
+
+    /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+     *
+     *           Maybe inform waiting closer
+     *
+     * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+     */
+
+    if (descP->sock != INVALID_SOCKET) {
+
+        if (descP->closeLocal) {
+
+            if (!is_direct_call) {
+                
+                /* +++ send close message to the waiting process +++ */
+
+                esock_send_close_msg(env, descP, &descP->closerPid);
+
+                DEMONP("esock_stop -> closer", env, descP, &descP->closerMon);
+
+            } else {
+
+                /* We only need to explicitly free the environment here
+                 * since the message send takes care of it if scheduled.
+                 */
+
+                if (descP->closeEnv != NULL)
+                    esock_free_env("esock_stop - close-env", descP->closeEnv);
+
+            }
+        }
+    }
+    
+
+    SSDBG( descP, ("SOCKET", "esock_stop -> unlock all mutex(s)\r\n") );
+
+    if (!is_direct_call) MUNLOCK(descP->closeMtx);
+    MUNLOCK(descP->cfgMtx);
+    MUNLOCK(descP->accMtx);
+    MUNLOCK(descP->readMtx);
+    MUNLOCK(descP->writeMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "esock_stop -> done (%d, %d)\r\n", descP->sock, fd) );
+
+#endif // if !defined(__WIN32__)
+}
+
+
+
+/* *** esock_stop_handle_current ***
+ *
+ * Handle current requestor (reader, writer or acceptor) during
+ * socket stop.
+ */
+#if !defined(__WIN32__)
+static
+void esock_stop_handle_current(ErlNifEnv*       env,
+                               const char*      role,
+                               ESockDescriptor* descP,
+                               ERL_NIF_TERM     sockRef,
+                               ESockRequestor*  reqP)
+{
+    SSDBG( descP, ("SOCKET", "esock_stop -> handle current %s\r\n", role) );
+
+    DEMONP("esock_stop_handle_current", env, descP, &reqP->mon);
+
+    if (COMPARE_PIDS(&descP->closerPid, &reqP->pid) != 0) {
+
+        SSDBG( descP, ("SOCKET", "esock_stop_handle_current -> "
+                       "send abort message to current %s %T\r\n",
+                       role, reqP->pid) );
+
+        if (esock_send_abort_msg(env, sockRef, reqP->ref, reqP->env,
+                                 atom_closed, &reqP->pid) != NULL) {
+
+            esock_warning_msg("Failed sending abort (%T) message to "
+                              "current %s %T\r\n",
+                              reqP->ref, role, reqP->pid);
+        }
+        reqP->env = NULL;
+    }
+}
+
+
+
+/* This function traverse the queue and sends the specified
+ * nif_abort message with the specified reason to each member,
+ * and if the 'free' argument is TRUE, the queue will be emptied.
+ */
+static
+void inform_waiting_procs(ErlNifEnv*         env,
+                          const char*        role,
+                          ESockDescriptor*   descP,
+                          ERL_NIF_TERM       sockRef,
+                          ESockRequestQueue* q,
+                          BOOLEAN_T          free,
+                          ERL_NIF_TERM       reason)
+{
+    ESockRequestQueueElement* currentP = q->first;
+    ESockRequestQueueElement* nextP;
+
+    SSDBG( descP,
+           ("SOCKET",
+            "inform_waiting_procs -> handle waiting %s(s)\r\n", role) );
+
+    while (currentP != NULL) {
+
+        /* <KOLLA>
+         *
+         * Should we inform anyone if we fail to demonitor?
+         * NOT SURE WHAT THAT WOULD REPRESENT AND IT IS NOT
+         * IMPORTANT IN *THIS* CASE, BUT ITS A FUNDAMENTAL OP...
+         *
+         * </KOLLA>
+         */
+
+        SSDBG( descP,
+               ("SOCKET",
+                "inform_waiting_procs -> abort request %T (from %T)\r\n",
+                currentP->data.ref, currentP->data.pid) );
+
+        if (esock_send_abort_msg(env,
+                                 sockRef,
+                                 currentP->data.ref,
+                                 currentP->data.env,
+                                 reason,
+                                 &currentP->data.pid) != NULL) {
+
+            esock_warning_msg("Failed sending abort (%T) message to "
+                              "current %s %T\r\n",
+                              currentP->data.ref,
+                              role,
+                              currentP->data.pid);
+
+        }
+        currentP->data.env = NULL,
+
+        DEMONP("inform_waiting_procs -> current 'request'",
+               env, descP, &currentP->data.mon);
+        nextP = currentP->nextP;
+        if (free) FREE(currentP);
+        currentP = nextP;
+    }
+
+    if (free) {
+        q->first = NULL;
+        q->last  = NULL;
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+/* =========================================================================
+ * esock_down - Callback function for resource down (monitored processes)
+ *
+ */
+static
+void esock_down(ErlNifEnv*           env,
+                void*                obj,
+                const ErlNifPid*     pid,
+                const ErlNifMonitor* mon)
+{
+#if !defined(__WIN32__)
+    ESockDescriptor* descP = (ESockDescriptor*) obj;
+    int              sres;
+    ERL_NIF_TERM     sockRef;
+
+    SSDBG( descP, ("SOCKET", "esock_down -> entry with"
+                   "\r\n   sock:  %d"
+                   "\r\n   pid:   %T"
+                   "\r\n   Close: %s (%s)"
+                   "\r\n",
+                   descP->sock, *pid,
+                   B2S(IS_CLOSED(descP)),
+                   B2S(IS_CLOSING(descP))) );
+
+    if (!IS_CLOSED(descP)) {
+
+        if (COMPARE_PIDS(&descP->ctrlPid, pid) == 0) {
+
+            /* We don't bother with the queue cleanup here - 
+             * we leave it to the stop callback function.
+             */
+
+            SSDBG( descP,
+                   ("SOCKET", "esock_down -> controlling process exit\r\n") );
+
+            descP->state      = ESOCK_STATE_CLOSING;
+            descP->closeLocal = TRUE;
+            descP->closerPid  = *pid;
+            MON_INIT(&descP->closerMon);
+
+            sres = esock_select_stop(env, descP->sock, descP);
+
+            if (sres & ERL_NIF_SELECT_STOP_CALLED) {
+
+                /* We are done - we can finalize (socket close) directly */
+                SSDBG( descP,
+                       ("SOCKET", 
+                        "esock_down -> [%d] stop called\r\n", descP->sock) );
+
+                dec_socket(descP->domain, descP->type, descP->protocol);
+                descP->state = ESOCK_STATE_CLOSED;
+
+                /* And finally close the socket.
+                 * Since we close the socket because of an exiting owner,
+                 * we do not need to wait for buffers to sync (linger).
+                 * If the owner wish to ensure the buffer are written,
+                 * it should have closed the socket explicitly...
+                 */
+                if (sock_close(descP->sock) != 0) {
+                    int save_errno = sock_errno();
+
+                    esock_warning_msg("Failed closing socket for terminating "
+                                      "controlling process: "
+                                      "\r\n   Controlling Process: %T"
+                                      "\r\n   Descriptor:          %d"
+                                      "\r\n   Errno:               %d"
+                                      "\r\n", pid, descP->sock, save_errno);
+                }
+                sock_close_event(descP->event);
+
+                descP->sock  = INVALID_SOCKET;
+                descP->event = INVALID_EVENT;
+
+                descP->state = ESOCK_STATE_CLOSED;
+
+            } else if (sres & ERL_NIF_SELECT_STOP_SCHEDULED) {
+
+                /* The stop callback function has been *scheduled* which means
+                 * that "should" wait for it to complete. But since we are in
+                 * a callback (down) function, we cannot...
+                 * So, we must close the socket
+                 */
+                SSDBG( descP,
+                       ("SOCKET",
+                        "esock_down -> [%d] stop scheduled\r\n",
+                        descP->sock) );
+
+                dec_socket(descP->domain, descP->type, descP->protocol);
+
+                /* And now what? We can't wait for the stop function here... 
+                 * So, we simply close it here and leave the rest of the "close"
+                 * for later (when the stop function actually gets called...
+                 */
+
+                if (sock_close(descP->sock) != 0) {
+                    int save_errno = sock_errno();
+
+                    esock_warning_msg("Failed closing socket for terminating "
+                                      "controlling process: "
+                                      "\r\n   Controlling Process: %T"
+                                      "\r\n   Descriptor:          %d"
+                                      "\r\n   Errno:               %d"
+                                      "\r\n", pid, descP->sock, save_errno);
+                }
+                sock_close_event(descP->event);
+
+            } else {
+
+                esock_warning_msg("Failed selecting stop when handling down "
+                                  "of controlling process: "
+                                  "\r\n   Select Res:          %d"
+                                  "\r\n   Controlling Process: %T"
+                                  "\r\n   Descriptor:          %d"
+                                  "\r\n   Monitor:             %T"
+                                  "\r\n", sres, pid, descP->sock,
+                                  MON2T(env, mon));
+            }
+
+        } else if (COMPARE_PIDS(&descP->connPid, pid) == 0) {
+
+            /* The connPid is only set during the connection.
+             * The same goes for the monitor (connMon).
+             */
+
+            descP->state = ESOCK_STATE_OPEN;  /* restore state */
+            enif_set_pid_undefined(&descP->connPid);
+            DEMONP("esock_down -> connector",
+                   env, descP, &descP->connMon);
+
+        } else {
+
+            /* check all operation queue(s): acceptor, writer and reader. 
+             *
+             * Is it really any point in doing this if the socket is closed?
+             *
+             */
+
+            SSDBG( descP, ("SOCKET", "esock_down -> other process term\r\n") );
+
+            sockRef = enif_make_resource(env, descP);
+
+            MLOCK(descP->accMtx);
+            if (descP->currentAcceptorP != NULL)
+                esock_down_acceptor(env, descP, sockRef, pid);
+            MUNLOCK(descP->accMtx);
+
+            MLOCK(descP->writeMtx);
+            if (descP->currentWriterP != NULL)
+                esock_down_writer(env, descP, sockRef, pid);
+            MUNLOCK(descP->writeMtx);
+
+            MLOCK(descP->readMtx);
+            if (descP->currentReaderP != NULL)
+                esock_down_reader(env, descP, sockRef, pid);
+            MUNLOCK(descP->readMtx);
+
+        }
+    }
+
+    SSDBG( descP, ("SOCKET", "esock_down -> done\r\n") );
+
+#endif // if !defined(__WIN32__)
+}
+
+
+
+/* *** esock_down_acceptor ***
+ *
+ * Check and then handle a downed acceptor process.
+ *
+ */
+#if !defined(__WIN32__)
+static
+void esock_down_acceptor(ErlNifEnv*       env,
+                          ESockDescriptor* descP,
+                          ERL_NIF_TERM     sockRef,
+                          const ErlNifPid* pid)
+{
+    if (COMPARE_PIDS(&descP->currentAcceptor.pid, pid) == 0) {
+        
+        SSDBG( descP, ("SOCKET",
+                       "esock_down_acceptor -> "
+                       "current acceptor - try activate next\r\n") );
+        
+        if (!activate_next_acceptor(env, descP, sockRef)) {
+
+            SSDBG( descP,
+                   ("SOCKET", "esock_down_acceptor -> no more writers\r\n") );
+
+            descP->state               = ESOCK_STATE_LISTENING;
+
+            descP->currentAcceptorP    = NULL;
+            descP->currentAcceptor.ref = esock_atom_undefined;
+            enif_set_pid_undefined(&descP->currentAcceptor.pid);
+            esock_monitor_init(&descP->currentAcceptor.mon);
+        }
+
+    } else {
+        
+        /* Maybe unqueue one of the waiting acceptors */
+        
+        SSDBG( descP, ("SOCKET",
+                       "esock_down_acceptor -> "
+                       "not current acceptor - maybe a waiting acceptor\r\n") );
+        
+        acceptor_unqueue(env, descP, pid);
+    }
+}
+
+
+
+
+/* *** esock_down_writer ***
+ *
+ * Check and then handle a downed writer process.
+ *
+ */
+static
+void esock_down_writer(ErlNifEnv*       env,
+                        ESockDescriptor* descP,
+                        ERL_NIF_TERM     sockRef,
+                        const ErlNifPid* pid)
+{
+    if (COMPARE_PIDS(&descP->currentWriter.pid, pid) == 0) {
+        
+        SSDBG( descP, ("SOCKET",
+                       "esock_down_writer -> "
+                       "current writer - try activate next\r\n") );
+        
+        if (!activate_next_writer(env, descP, sockRef)) {
+            SSDBG( descP, ("SOCKET",
+                           "esock_down_writer -> no active writer\r\n") );
+            descP->currentWriterP    = NULL;
+            descP->currentWriter.ref = esock_atom_undefined;
+            enif_set_pid_undefined(&descP->currentWriter.pid);
+            esock_monitor_init(&descP->currentWriter.mon);
+        }
+        
+    } else {
+        
+        /* Maybe unqueue one of the waiting writer(s) */
+        
+        SSDBG( descP, ("SOCKET",
+                       "esock_down_writer -> "
+                       "not current writer - maybe a waiting writer\r\n") );
+        
+        writer_unqueue(env, descP, pid);
+    }
+}
+
+
+
+
+/* *** esock_down_reader ***
+ *
+ * Check and then handle a downed reader process.
+ *
+ */
+static
+void esock_down_reader(ErlNifEnv*       env,
+                        ESockDescriptor* descP,
+                        ERL_NIF_TERM     sockRef,
+                        const ErlNifPid* pid)
+{
+    if (COMPARE_PIDS(&descP->currentReader.pid, pid) == 0) {
+        
+        SSDBG( descP, ("SOCKET",
+                       "esock_down_reader -> "
+                       "current reader - try activate next\r\n") );
+        
+        if (!activate_next_reader(env, descP, sockRef)) {
+            SSDBG( descP,
+                   ("SOCKET",
+                    "esock_down_reader -> no more readers\r\n") );
+            descP->currentReaderP    = NULL;
+            descP->currentReader.ref = esock_atom_undefined;
+            enif_set_pid_undefined(&descP->currentReader.pid);
+            esock_monitor_init(&descP->currentReader.mon);
+        }
+
+    } else {
+        
+        /* Maybe unqueue one of the waiting reader(s) */
+        
+        SSDBG( descP, ("SOCKET",
+                       "esock_down_reader -> "
+                       "not current reader - maybe a waiting reader\r\n") );
+        
+        reader_unqueue(env, descP, pid);
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  L o a d / u n l o a d / u p g r a d e   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+static
+ErlNifFunc esock_funcs[] =
+{
+    // Some utility and support functions
+    {"nif_info",                0, nif_info, 0},
+    {"nif_info",                1, nif_info, 0},
+    {"nif_supports",            1, nif_supports, 0},
+    {"nif_command",             1, nif_command, 0},
+
+    // The proper "socket" interface
+    // nif_open/1 is (supposed to be) used when we already have a file descriptor
+    // {"nif_open",                1, nif_open, 0},
+    {"nif_open",                4, nif_open, 0},
+    {"nif_bind",                2, nif_bind, 0},
+    {"nif_connect",             2, nif_connect, 0},
+    {"nif_listen",              2, nif_listen, 0},
+    {"nif_accept",              2, nif_accept, 0},
+    {"nif_send",                4, nif_send, 0},
+    {"nif_sendto",              5, nif_sendto, 0},
+    {"nif_sendmsg",             4, nif_sendmsg, 0},
+    {"nif_recv",                4, nif_recv, 0},
+    {"nif_recvfrom",            4, nif_recvfrom, 0},
+    {"nif_recvmsg",             5, nif_recvmsg, 0},
+    {"nif_close",               1, nif_close, 0},
+    {"nif_shutdown",            2, nif_shutdown, 0},
+    {"nif_setopt",              5, nif_setopt, 0},
+    {"nif_getopt",              4, nif_getopt, 0},
+    {"nif_sockname",            1, nif_sockname, 0},
+    {"nif_peername",            1, nif_peername, 0},
+
+    /* Misc utility functions */
+
+    /* "Extra" functions to "complete" the socket interface.
+     * For instance, the function nif_finalize_connection
+     * is called after the connect *select* has "completed".
+     */
+    {"nif_finalize_connection", 1, nif_finalize_connection, 0},
+    {"nif_cancel",              3, nif_cancel, 0},
+    {"nif_finalize_close",      1, nif_finalize_close, ERL_NIF_DIRTY_JOB_IO_BOUND}
+};
+
+
+#if !defined(__WIN32__)
+static
+BOOLEAN_T extract_debug(ErlNifEnv*   env,
+                        ERL_NIF_TERM map)
+{
+    /*
+     * We need to do this here since the "proper" atom has not been
+     * created when this function is called.
+     */
+    ERL_NIF_TERM debug = MKA(env, "debug");
+    
+    return esock_extract_bool_from_map(env, map, debug, ESOCK_GLOBAL_DEBUG_DEFAULT);
+}
+
+static
+BOOLEAN_T extract_iow(ErlNifEnv*   env,
+                      ERL_NIF_TERM map)
+{
+    /*
+     * We need to do this here since the "proper" atom has not been
+     * created when this function is called.
+     */
+    ERL_NIF_TERM iow = MKA(env, "iow");
+    
+    return esock_extract_bool_from_map(env, map, iow, ESOCK_NIF_IOW_DEFAULT);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* =======================================================================
+ * load_info - A map of misc info (e.g global debug)
+ */
+
+static
+int on_load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info)
+{
+#if !defined(__WIN32__)    
+    esock_dbg_init(ESOCK_DBGOUT_DEFAULT);
+    // esock_dbg_init(ESOCK_DBGOUT_UNIQUE);
+
+    data.dbg = extract_debug(env, load_info);
+    data.iow = extract_iow(env, load_info);
+
+    /* +++ Global Counters +++ */
+    data.cntMtx         = MCREATE("esock[gcnt]");
+    data.numSockets     = 0;
+    data.numTypeDGrams  = 0;
+    data.numTypeStreams = 0;
+    data.numTypeSeqPkgs = 0;
+    data.numDomainLocal = 0;
+    data.numDomainInet  = 0;
+    data.numDomainInet6 = 0;
+    data.numProtoIP     = 0;
+    data.numProtoTCP    = 0;
+    data.numProtoUDP    = 0;
+    data.numProtoSCTP   = 0;
+#endif
+
+    /* +++ Local atoms and error reason atoms +++ */
+#define LOCAL_ATOM_DECL(A) atom_##A = MKA(env, #A)
+LOCAL_ATOMS
+LOCAL_ERROR_REASON_ATOMS
+#undef LOCAL_ATOM_DECL
+
+    /* Global atom(s) and error reason atom(s) */
+#define GLOBAL_ATOM_DECL(A) esock_atom_##A = MKA(env, #A)
+GLOBAL_ATOMS
+GLOBAL_ERROR_REASON_ATOMS
+#undef GLOBAL_ATOM_DECL
+    esock_atom_socket_tag = MKA(env, "$socket");
+
+    esocks = enif_open_resource_type_x(env,
+                                       "sockets",
+                                       &esockInit,
+                                       ERL_NIF_RT_CREATE,
+                                       NULL);
+
+    return !esocks;
+}
+
+/*
+ * MODULE:  socket (the erlang API/interface module)
+ * funcs:   esock_funcs (defines the API of this nif)
+ * load:    on_load (load this nif)
+ * upgrade: NULL (not used)
+ * NULL:    THIS IS NOT USED
+ * unload:  NULL (not used)
+ */
+ERL_NIF_INIT(socket, esock_funcs, on_load, NULL, NULL, NULL)
diff --git a/erts/emulator/nifs/common/socket_tarray.c b/erts/emulator/nifs/common/socket_tarray.c
new file mode 100644
index 0000000000..def22c4919
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_tarray.c
@@ -0,0 +1,143 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Build and "maintain" a (erlang) term array of 
+ *            variable length.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+/* #ifdef HAVE_CONFIG_H */
+/* #include "config.h" */
+/* #endif */
+
+#include <stdio.h>
+
+#include <erl_nif.h>
+
+#include "socket_int.h"
+#include <sys.h>
+#include "socket_util.h"
+#include "socket_tarray.h"
+
+
+
+/* ----------------------------------------------------------------------
+ * Types 
+ */
+
+typedef struct {
+  Uint32        sz;
+  Uint32        idx;
+  ERL_NIF_TERM* array;
+} SocketTArrayInt;
+
+
+/* ----------------------------------------------------------------------
+ * Forward for internal functions
+ */
+
+static void esock_tarray_add1(SocketTArrayInt* taP, ERL_NIF_TERM t);
+static void esock_tarray_ensure_fits(SocketTArrayInt* taP, Uint32 needs);
+
+
+/* ----------------------------------------------------------------------
+ * API
+ */
+
+extern
+void* esock_tarray_create(Uint32 sz)
+{
+    SocketTArrayInt* tarrayP;
+
+    ESOCK_ASSERT( (sz > 0) );
+
+    tarrayP = MALLOC(sizeof(SocketTArrayInt));
+    ESOCK_ASSERT( (tarrayP != NULL) );
+  
+    tarrayP->array = MALLOC(sz * sizeof(ERL_NIF_TERM));
+    ESOCK_ASSERT( (tarrayP->array != NULL) );
+    tarrayP->sz   = sz;
+    tarrayP->idx  = 0;
+    
+    return ((SocketTArray) tarrayP);
+}
+
+extern
+void esock_tarray_delete(SocketTArray ta)
+{
+    SocketTArrayInt* taP = (SocketTArrayInt*) ta;
+
+    FREE(taP->array);
+    FREE(taP);
+}
+
+
+extern
+Uint32 esock_tarray_sz(SocketTArray a)
+{
+  return ( ((SocketTArrayInt*) a)->idx );
+}
+
+extern
+void esock_tarray_add(SocketTArray ta, ERL_NIF_TERM t)
+{
+    esock_tarray_add1((SocketTArrayInt*) ta, t);
+}
+
+extern
+void esock_tarray_tolist(SocketTArray  ta,
+                         ErlNifEnv*    env,
+                         ERL_NIF_TERM* list)
+{
+    SocketTArrayInt* taP = (SocketTArrayInt*) ta;
+
+    *list = MKLA(env, taP->array, taP->idx);
+
+    esock_tarray_delete(taP);
+}
+
+
+
+/* ----------------------------------------------------------------------
+ * "Internal" functions
+ */
+
+static
+void esock_tarray_add1(SocketTArrayInt* taP, ERL_NIF_TERM t)
+{
+  esock_tarray_ensure_fits(taP, 1);
+
+  taP->array[taP->idx++] = t;
+}
+
+static
+void esock_tarray_ensure_fits(SocketTArrayInt* taP, Uint32 needs)
+{ 
+  if (taP->sz < (taP->idx + needs)) {
+    Uint32 newSz = (needs < taP->sz) ? 2*taP->sz : 2*needs;
+    void*  mem   = REALLOC(taP->array, newSz * sizeof(ERL_NIF_TERM));
+    
+    ESOCK_ASSERT( (mem != NULL) );
+    
+    taP->sz    = newSz;
+    taP->array = (ERL_NIF_TERM*) mem;
+  }
+}
diff --git a/erts/emulator/nifs/common/socket_tarray.h b/erts/emulator/nifs/common/socket_tarray.h
new file mode 100644
index 0000000000..4f1152fb9e
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_tarray.h
@@ -0,0 +1,47 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Build and "maintain" a (erlang) term array of 
+ *            variable length.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#ifndef SOCKET_TARRAY_H__
+#define SOCKET_TARRAY_H__
+
+typedef void* SocketTArray;
+
+extern SocketTArray esock_tarray_create(Uint32 sz);
+extern void         esock_tarray_delete(SocketTArray ta);
+extern Uint32       esock_tarray_sz(SocketTArray ta);
+extern void         esock_tarray_add(SocketTArray ta, ERL_NIF_TERM t);
+extern void         esock_tarray_tolist(SocketTArray  ta,
+                                        ErlNifEnv*    env,
+                                        ERL_NIF_TERM* list);
+
+#define TARRAY_CREATE(SZ)        esock_tarray_create((SZ))
+#define TARRAY_DELETE(TA)        esock_tarray_delete((TA))
+#define TARRAY_SZ(TA)            esock_tarray_sz((TA))
+#define TARRAY_ADD(TA, T)        esock_tarray_add((TA), (T))
+#define TARRAY_TOLIST(TA, E, L)  esock_tarray_tolist((TA), (E), (L))
+
+
+#endif // SOCKET_TARRAY_H__
diff --git a/erts/emulator/nifs/common/socket_util.c b/erts/emulator/nifs/common/socket_util.c
new file mode 100644
index 0000000000..54c310ecc7
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_util.c
@@ -0,0 +1,1699 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Utility functions for the socket and net NIF(s).
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <time.h>
+#include <stddef.h>
+
+#include "socket_int.h"
+#include "sys.h"
+#include "socket_util.h"
+#include "socket_dbg.h"
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* We don't have a "debug flag" to check here, so we 
+ * should use the compile debug flag, whatever that is...
+ */
+
+// #define COMPILE_DEBUG_FLAG_WE_NEED_TO_CHECK 1
+#if defined(COMPILE_DEBUG_FLAG_WE_NEED_TO_CHECK)
+#define UTIL_DEBUG TRUE
+#else
+#define UTIL_DEBUG FALSE
+#endif
+
+#define UDBG( proto ) ESOCK_DBG_PRINTF( UTIL_DEBUG , proto )
+
+
+extern char* erl_errno_id(int error); /* THIS IS JUST TEMPORARY??? */
+
+#if (defined(HAVE_LOCALTIME_R) && defined(HAVE_STRFTIME))
+#define ESOCK_USE_PRETTY_TIMESTAMP 1
+#endif
+    
+
+static char* make_sockaddr_in4(ErlNifEnv*    env,
+                               ERL_NIF_TERM  port,
+                               ERL_NIF_TERM  addr,
+                               ERL_NIF_TERM* sa);
+static char* make_sockaddr_in6(ErlNifEnv*    env,
+                               ERL_NIF_TERM  port,
+                               ERL_NIF_TERM  addr,
+                               ERL_NIF_TERM  flowInfo,
+                               ERL_NIF_TERM  scopeId,
+                               ERL_NIF_TERM* sa);
+static char* make_sockaddr_un(ErlNifEnv*    env,
+                              ERL_NIF_TERM  path,
+                              ERL_NIF_TERM* sa);
+
+
+/* +++ esock_encode_iov +++
+ *
+ * Encode an IO Vector. In erlang we represented this as a list of binaries.
+ *
+ * We iterate through the IO vector, and as long as the remaining (rem)
+ * number of bytes is greater than the size of the current buffer, we
+ * contunue. When we have a buffer that is greater than rem, we have found
+ * the last buffer (it may be empty, and then the previous was last). 
+ * We may need to split this (if 0 < rem < bufferSz).
+ */
+
+extern
+char* esock_encode_iov(ErlNifEnv*    env,
+                       int           read,
+                       struct iovec* iov,
+                       size_t        len,
+                       ErlNifBinary* data,
+                       ERL_NIF_TERM* eIOV)
+{
+    int          rem = read;
+    Uint16       i;
+    BOOLEAN_T    done = FALSE;
+    ERL_NIF_TERM a[len]; // At most this length
+
+    UDBG( ("SUTIL", "esock_encode_iov -> entry with"
+           "\r\n   read:      %d"
+           "\r\n   (IOV) len: %d"
+           "\r\n", read, len) );
+
+    if (len == 0) {
+        *eIOV = MKEL(env);
+        return NULL;
+    }
+
+    for (i = 0; (!done) && (i < len); i++) {
+        UDBG( ("SUTIL", "esock_encode_iov -> process iov:"
+               "\r\n   iov[%d].iov_len: %d"
+               "\r\n   rem:            %d"
+               "\r\n", i, iov[i].iov_len, rem) );
+        if (iov[i].iov_len == rem) {
+            /* We have the exact amount - we are done */
+            UDBG( ("SUTIL", "esock_encode_iov -> exact => done\r\n") );
+            a[i] = MKBIN(env, &data[i]);
+            rem  = 0; // Besserwisser
+            done = TRUE;
+        } else if (iov[i].iov_len < rem) {
+            /* Filled another buffer - continue */
+            UDBG( ("SUTIL", "esock_encode_iov -> filled => continue\r\n") );
+            a[i] = MKBIN(env, &data[i]);
+            rem -= iov[i].iov_len;
+        } else if (iov[i].iov_len > rem) {
+            /* Partly filled buffer (=> split) - we are done */
+            ERL_NIF_TERM tmp;
+            UDBG( ("SUTIL", "esock_encode_iov -> split => done\r\n") );
+            tmp  = MKBIN(env, &data[i]);
+            a[i] = MKSBIN(env, tmp, 0, rem);
+            rem  = 0; // Besserwisser
+            done = TRUE;
+        }
+    }
+
+    UDBG( ("SUTIL", "esock_encode_iov -> create the IOV list (%d)\r\n", i) );
+
+    *eIOV = MKLA(env, a, i);
+
+    UDBG( ("SUTIL", "esock_encode_msghdr -> done\r\n") );
+
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_iov +++
+ *
+ * Decode an IO Vector. In erlang we represented this as a list of binaries.
+ *
+ * We assume that we have already figured out how long the iov (actually
+ * eIOV) is (len), and therefor allocated an array of bins and iov to be
+ * used.
+ */
+
+extern
+char* esock_decode_iov(ErlNifEnv*    env,
+                       ERL_NIF_TERM  eIOV,
+                       ErlNifBinary* bufs,
+                       struct iovec* iov,
+                       size_t        len,
+                       ssize_t*      totSize)
+{
+    Uint16       i;
+    ssize_t      sz;
+    ERL_NIF_TERM elem, tail, list;
+
+    UDBG( ("SUTIL", "esock_decode_iov -> entry with"
+           "\r\n   (IOV) len: %d"
+           "\r\n", read, len) );
+
+    for (i = 0, list = eIOV, sz = 0; (i < len); i++) {
+
+        UDBG( ("SUTIL", "esock_decode_iov -> "
+               "\r\n   iov[%d].iov_len: %d"
+               "\r\n   rem:            %d"
+               "\r\n", i) );
+
+        if (!GET_LIST_ELEM(env, list, &elem, &tail))
+            return ESOCK_STR_EINVAL;
+
+        if (IS_BIN(env, elem) && GET_BIN(env, elem, &bufs[i])) {
+            iov[i].iov_base  = (caddr_t) bufs[i].data;
+            iov[i].iov_len   = bufs[i].size;
+            sz              += bufs[i].size;
+        } else {
+            return ESOCK_STR_EINVAL;
+        }
+
+        list = tail;
+    }
+
+    *totSize = sz;
+
+    UDBG( ("SUTIL", "esock_decode_msghdr -> done (%d)\r\n", sz) );
+
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_sockaddr +++
+ *
+ * Decode a socket address - sockaddr. In erlang its represented as
+ * a map, which has a specific set of attributes, depending on one
+ * mandatory attribute; family. So depending on the value of the family
+ * attribute: 
+ *
+ *    local - sockaddr_un:  path
+ *    inet  - sockaddr_in4: port, addr
+ *    inet6 - sockaddr_in6: port, addr, flowinfo, scope_id
+ */
+
+extern
+char* esock_decode_sockaddr(ErlNifEnv*    env,
+                            ERL_NIF_TERM  eSockAddr,
+                            ESockAddress* sockAddrP,
+                            unsigned int* addrLen)
+{
+    ERL_NIF_TERM efam;
+    int          fam;
+    char*        xres;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr -> entry\r\n") );
+
+    if (!IS_MAP(env, eSockAddr))
+        return ESOCK_STR_EINVAL;
+
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_family, &efam))
+        return ESOCK_STR_EINVAL;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr -> try decode domain (%T)\r\n", efam) );
+    if ((xres = esock_decode_domain(env, efam, &fam)) != NULL)
+        return xres;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr -> fam: %d\r\n", fam) );
+    switch (fam) {
+    case AF_INET:
+        xres = esock_decode_sockaddr_in4(env, eSockAddr,
+                                         &sockAddrP->in4, addrLen);
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case AF_INET6:
+        xres = esock_decode_sockaddr_in6(env, eSockAddr,
+                                         &sockAddrP->in6, addrLen);
+        break;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+    case AF_UNIX:
+        xres = esock_decode_sockaddr_un(env, eSockAddr,
+                                        &sockAddrP->un, addrLen);
+        break;
+#endif
+
+    default:
+        xres = ESOCK_STR_EAFNOSUPPORT;
+        break;
+
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_encode_sockaddr +++
+ *
+ * Encode a socket address - sockaddr. In erlang its represented as
+ * a map, which has a specific set of attributes, depending on one
+ * mandatory attribute; family. So depending on the value of the family
+ * attribute: 
+ *
+ *    local - sockaddr_un:  path
+ *    inet  - sockaddr_in4: port, addr
+ *    inet6 - sockaddr_in6: port, addr, flowinfo, scope_id
+ */
+
+extern
+char* esock_encode_sockaddr(ErlNifEnv*    env,
+                            ESockAddress* sockAddrP,
+                            unsigned int  addrLen,
+                            ERL_NIF_TERM* eSockAddr)
+{
+    char* xres;
+
+    UDBG( ("SUTIL", "esock_encode_sockaddr -> entry with"
+           "\r\n   family:  %d"
+           "\r\n   addrLen: %d"
+           "\r\n", sockAddrP->sa.sa_family, addrLen) );
+
+    switch (sockAddrP->sa.sa_family) {
+    case AF_INET:
+        xres = esock_encode_sockaddr_in4(env, &sockAddrP->in4, addrLen, eSockAddr);
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case AF_INET6:
+        xres = esock_encode_sockaddr_in6(env, &sockAddrP->in6, addrLen, eSockAddr);
+        break;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+    case AF_UNIX:
+        xres = esock_encode_sockaddr_un(env, &sockAddrP->un, addrLen, eSockAddr);
+        break;
+#endif
+
+    default:
+        *eSockAddr = esock_atom_undefined;
+        xres       = ESOCK_STR_EAFNOSUPPORT;
+        break;
+
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_sockaddr_in4 +++
+ *
+ * Decode a IPv4 socket address - sockaddr_in4. In erlang its represented as
+ * a map, which has a specific set of attributes (beside the mandatory family
+ * attribute, which is "inherited" from the "sockaddr" type): 
+ *
+ *    port :: port_numbber()
+ *    addr :: ip4_address()
+ *
+ * The erlang module ensures that both of these has values exist, so there 
+ * is no need for any elaborate error handling.
+ */
+
+extern
+char* esock_decode_sockaddr_in4(ErlNifEnv*          env,
+                                ERL_NIF_TERM        eSockAddr,
+                                struct sockaddr_in* sockAddrP,
+                                unsigned int*       addrLen)
+{
+    ERL_NIF_TERM eport, eaddr;
+    int          port;
+    char*        xres;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> entry\r\n") );
+
+    /* Basic init */
+    sys_memzero((char*) sockAddrP, sizeof(struct sockaddr_in));
+
+#ifndef NO_SA_LEN
+    sockAddrP->sin_len = sizeof(struct sockaddr_in);
+#endif
+
+    sockAddrP->sin_family = AF_INET;
+
+    /* Extract (e) port number from map */
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> try get port number\r\n") );
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_port, &eport))
+        return ESOCK_STR_EINVAL;
+
+    /* Decode port number */
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> try decode port number\r\n") );
+    if (!GET_INT(env, eport, &port))
+        return ESOCK_STR_EINVAL;
+    
+    sockAddrP->sin_port = htons(port);
+
+    /* Extract (e) address from map */
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> try get (ip) address\r\n") );
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_addr, &eaddr))
+        return ESOCK_STR_EINVAL;
+
+    /* Decode address */
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> try decode (ip) address\r\n") );
+    if ((xres = esock_decode_ip4_address(env,
+                                         eaddr,
+                                         &sockAddrP->sin_addr)) != NULL)
+        return xres;
+
+    *addrLen = sizeof(struct sockaddr_in);
+    
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> done\r\n") );
+
+    return NULL;
+}
+
+
+
+/* +++ esock_encode_sockaddr_in4 +++
+ *
+ * Encode a IPv4 socket address - sockaddr_in4. In erlang its represented as
+ * a map, which has a specific set of attributes (beside the mandatory family
+ * attribute, which is "inherited" from the "sockaddr" type):
+ *
+ *    port :: port_numbber()
+ *    addr :: ip4_address()
+ *
+ */
+
+extern
+char* esock_encode_sockaddr_in4(ErlNifEnv*          env,
+                                struct sockaddr_in* sockAddrP,
+                                unsigned int        addrLen,
+                                ERL_NIF_TERM*       eSockAddr)
+{
+    ERL_NIF_TERM ePort, eAddr;
+    int          port;
+    char*        xres = NULL;
+
+    UDBG( ("SUTIL", "esock_encode_sockaddr_in4 -> entry\r\n") );
+
+    if (addrLen >= sizeof(struct sockaddr_in)) {
+        /* The port */
+        port  = ntohs(sockAddrP->sin_port);
+        ePort = MKI(env, port);
+
+        /* The address */
+        if ((xres = esock_encode_ip4_address(env, &sockAddrP->sin_addr,
+                                             &eAddr)) == NULL) {
+            /* And finally construct the in4_sockaddr record */
+            xres = make_sockaddr_in4(env, ePort, eAddr, eSockAddr);
+        } else {
+            UDBG( ("SUTIL", "esock_encode_sockaddr_in4 -> "
+                   "failed encoding (ip) address: "
+                   "\r\n   xres: %s"
+                   "\r\n", xres) );
+            *eSockAddr = esock_atom_undefined;
+            xres       = ESOCK_STR_EINVAL;
+        }
+
+    } else {
+        UDBG( ("SUTIL", "esock_encode_sockaddr_in4 -> wrong size: "
+               "\r\n   addrLen:   %d"
+               "\r\n   addr size: %d"
+               "\r\n", addrLen, sizeof(struct sockaddr_in)) );
+        *eSockAddr = esock_atom_undefined;
+        xres       = ESOCK_STR_EINVAL;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_sockaddr_in6 +++
+ *
+ * Decode a IPv6 socket address - sockaddr_in6. In erlang its represented as
+ * a map, which has a specific set of attributes (beside the mandatory family
+ * attribute, which is "inherited" from the "sockaddr" type): 
+ *
+ *    port     :: port_numbber()  (integer)
+ *    addr     :: ip6_address()   (tuple)
+ *    flowinfo :: in6_flow_info() (integer)
+ *    scope_id :: in6_scope_id()  (integer)
+ *
+ * The erlang module ensures that all of these has values exist, so there
+ * is no need for any elaborate error handling here.
+ */
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_decode_sockaddr_in6(ErlNifEnv*           env,
+                                ERL_NIF_TERM         eSockAddr,
+                                struct sockaddr_in6* sockAddrP,
+                                unsigned int*        addrLen)
+{
+    ERL_NIF_TERM eport, eaddr, eflowInfo, escopeId;
+    int          port;
+    unsigned int flowInfo, scopeId;
+    char*        xres;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> entry\r\n") );
+
+    /* Basic init */
+    sys_memzero((char*) sockAddrP, sizeof(struct sockaddr_in6));
+#ifndef NO_SA_LEN
+    sockAddrP->sin6_len = sizeof(struct sockaddr_in);
+#endif
+
+    sockAddrP->sin6_family = AF_INET6;
+
+    /* *** Extract (e) port number from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_port, &eport))
+        return ESOCK_STR_EINVAL;
+
+    /* Decode port number */
+    if (!GET_INT(env, eport, &port))
+        return ESOCK_STR_EINVAL;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> port: %d\r\n", port) );
+
+    sockAddrP->sin6_port = htons(port);
+
+    /* *** Extract (e) flowinfo from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_flowinfo, &eflowInfo))
+        return ESOCK_STR_EINVAL;
+
+    /* 4: Get the flowinfo */
+    if (!GET_UINT(env, eflowInfo, &flowInfo))
+        return ESOCK_STR_EINVAL;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> flowinfo: %d\r\n", flowInfo) );
+
+    sockAddrP->sin6_flowinfo = flowInfo;
+    
+    /* *** Extract (e) scope_id from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_scope_id, &escopeId))
+        return ESOCK_STR_EINVAL;
+
+    /* *** Get the scope_id *** */
+    if (!GET_UINT(env, escopeId, &scopeId))
+        return ESOCK_STR_EINVAL;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> scopeId: %d\r\n", scopeId) );
+
+    sockAddrP->sin6_scope_id = scopeId;
+
+    /* *** Extract (e) address from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_addr, &eaddr))
+        return ESOCK_STR_EINVAL;
+
+    /* Decode address */
+    if ((xres = esock_decode_ip6_address(env,
+                                         eaddr,
+                                         &sockAddrP->sin6_addr)) != NULL)
+        return xres;
+
+    *addrLen = sizeof(struct sockaddr_in6);
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> done\r\n") );
+
+    return NULL;
+}
+#endif
+
+
+
+/* +++ esock_encode_sockaddr_in6 +++
+ *
+ * Encode a IPv6 socket address - sockaddr_in6. In erlang its represented as
+ * a map, which has a specific set of attributes (beside the mandatory family
+ * attribute, which is "inherited" from the "sockaddr" type): 
+ *
+ *    port     :: port_numbber()  (integer)
+ *    addr     :: ip6_address()   (tuple)
+ *    flowinfo :: in6_flow_info() (integer)
+ *    scope_id :: in6_scope_id()  (integer)
+ *
+ */
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_encode_sockaddr_in6(ErlNifEnv*           env,
+                                struct sockaddr_in6* sockAddrP,
+                                unsigned int         addrLen,
+                                ERL_NIF_TERM*        eSockAddr)
+{
+    ERL_NIF_TERM ePort, eAddr, eFlowInfo, eScopeId;
+    char*        xres;
+
+    if (addrLen >= sizeof(struct sockaddr_in6)) {
+        /* The port */
+        ePort = MKI(env, ntohs(sockAddrP->sin6_port));
+
+        /* The flowInfo */
+        eFlowInfo = MKI(env, sockAddrP->sin6_flowinfo);
+            
+        /* The scopeId */
+        eScopeId = MKI(env, sockAddrP->sin6_scope_id);
+        
+        /* The address */
+        if ((xres = esock_encode_ip6_address(env, &sockAddrP->sin6_addr,
+                                             &eAddr)) == NULL) {
+            /* And finally construct the in6_sockaddr record */
+            xres = make_sockaddr_in6(env,
+                                     ePort, eAddr, eFlowInfo, eScopeId, eSockAddr);
+        } else {
+            *eSockAddr = esock_atom_undefined;
+            xres       = ESOCK_STR_EINVAL;
+        }
+
+    } else {
+        *eSockAddr = esock_atom_undefined;
+        xres       = ESOCK_STR_EINVAL;
+    }
+
+    return xres;
+}
+#endif
+
+
+
+/* +++ esock_decode_sockaddr_un +++
+ *
+ * Decode a Unix Domain socket address - sockaddr_un. In erlang its 
+ * represented as a map, which has a specific set of attributes
+ * (beside the mandatory family attribute, which is "inherited" from
+ * the "sockaddr" type):
+ *
+ *    path :: binary()
+ *
+ * The erlang module ensures that this value exist, so there 
+ * is no need for any elaborate error handling here.
+ */
+
+#ifdef HAVE_SYS_UN_H
+extern
+char* esock_decode_sockaddr_un(ErlNifEnv*          env,
+                               ERL_NIF_TERM        eSockAddr,
+                               struct sockaddr_un* sockAddrP,
+                               unsigned int*       addrLen)
+{
+    ErlNifBinary bin;
+    ERL_NIF_TERM epath;
+    unsigned int len;
+
+    /* *** Extract (e) path (a binary) from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_path, &epath))
+        return ESOCK_STR_EINVAL;
+
+    /* Get the path */
+    if (!GET_BIN(env, epath, &bin))
+        return ESOCK_STR_EINVAL;
+    
+    if ((bin.size +
+#ifdef __linux__
+         /* Make sure the address gets zero terminated
+          * except when the first byte is \0 because then it is
+          * sort of zero terminated although the zero termination
+          * comes before the address...
+          * This fix handles Linux's nonportable
+          * abstract socket address extension.
+          */
+         (bin.data[0] == '\0' ? 0 : 1)
+#else
+         1
+#endif
+         ) > sizeof(sockAddrP->sun_path))
+        return ESOCK_STR_EINVAL;
+
+
+    sys_memzero((char*) sockAddrP, sizeof(struct sockaddr_un));
+    sockAddrP->sun_family = AF_UNIX;
+
+    sys_memcpy(sockAddrP->sun_path, bin.data, bin.size);
+    len = offsetof(struct sockaddr_un, sun_path) + bin.size;
+
+#ifndef NO_SA_LEN
+    sockAddrP->sun_len = len;
+#endif
+    *addrLen = len;
+
+    return NULL;
+}
+#endif
+
+
+
+/* +++ esock_encode_sockaddr_un +++
+ *
+ * Encode a Unix Domain socket address - sockaddr_un. In erlang its 
+ * represented as a map, which has a specific set of attributes
+ * (beside the mandatory family attribute, which is "inherited" from
+ * the "sockaddr" type):
+ *
+ *    path :: binary()
+ *
+ */
+
+#ifdef HAVE_SYS_UN_H
+extern
+char* esock_encode_sockaddr_un(ErlNifEnv*          env,
+                               struct sockaddr_un* sockAddrP,
+                               unsigned int        addrLen,
+                               ERL_NIF_TERM*       eSockAddr)
+{
+    ERL_NIF_TERM ePath;
+    size_t       n, m;
+    char*        xres;
+
+    if (addrLen >= offsetof(struct sockaddr_un, sun_path)) {
+        n = addrLen - offsetof(struct sockaddr_un, sun_path);
+        if (255 < n) {
+            *eSockAddr = esock_atom_undefined;
+            xres       = ESOCK_STR_EINVAL;
+        } else {
+            m = esock_strnlen(sockAddrP->sun_path, n);
+#ifdef __linux__
+            /* Assume that the address is a zero terminated string,
+             * except when the first byte is \0 i.e the string length is 0,
+             * then use the reported length instead.
+             * This fix handles Linux's nonportable
+             * abstract socket address extension.
+             */
+            if (m == 0) {
+                m = n;
+            }
+#endif
+
+            /* And finally build the 'path' attribute */
+            ePath      = MKSL(env, sockAddrP->sun_path, m);
+
+            /* And the socket address */
+            xres = make_sockaddr_un(env, ePath, eSockAddr);
+        }
+    } else {
+        *eSockAddr = esock_atom_undefined;
+        xres       = ESOCK_STR_EINVAL;
+    }
+
+    return xres;
+}
+#endif
+
+
+
+/* +++ esock_decode_ip4_address +++
+ *
+ * Decode a IPv4 address. This can be three things:
+ *
+ *    + Then atom 'any'
+ *    + Then atom 'loopback'
+ *    + An ip4_address() (4 tuple)
+ *
+ * Note that this *only* decodes the "address" part of a
+ * (IPv4) socket address.
+ */
+
+extern
+char* esock_decode_ip4_address(ErlNifEnv*      env,
+                               ERL_NIF_TERM    eAddr,
+                               struct in_addr* inAddrP)
+{
+    struct in_addr addr;
+
+    UDBG( ("SUTIL", "esock_decode_ip4_address -> entry with"
+           "\r\n   eAddr: %T"
+           "\r\n", eAddr) );
+
+    if (IS_ATOM(env, eAddr)) {
+
+        /* This is either 'any' | 'broadcast' | 'loopback' */
+
+        if (COMPARE(esock_atom_loopback, eAddr) == 0) {
+            UDBG( ("SUTIL",
+		   "esock_decode_ip4_address -> address: lookback\r\n") );
+            addr.s_addr = htonl(INADDR_LOOPBACK);
+        } else if (COMPARE(esock_atom_any, eAddr) == 0) {
+	  UDBG( ("SUTIL",
+		 "esock_decode_ip4_address -> address: any\r\n") );
+	  addr.s_addr = htonl(INADDR_ANY);
+        } else if (COMPARE(esock_atom_broadcast, eAddr) == 0) {
+	  UDBG( ("SUTIL",
+		 "esock_decode_ip4_address -> address: broadcast\r\n") );
+	  addr.s_addr = htonl(INADDR_BROADCAST);
+        } else {
+            UDBG( ("SUTIL",
+		   "esock_decode_ip4_address -> address: unknown\r\n") );
+            return ESOCK_STR_EINVAL;
+        }
+
+        inAddrP->s_addr = addr.s_addr;
+
+    } else {
+        /* This is a 4-tuple */
+
+        const ERL_NIF_TERM* addrt;
+        int                 addrtSz;
+        int                 a, v;
+        char                addr[4];
+        
+        if (!GET_TUPLE(env, eAddr, &addrtSz, &addrt))
+            return ESOCK_STR_EINVAL;
+        
+        if (addrtSz != 4)
+            return ESOCK_STR_EINVAL;
+
+        for (a = 0; a < 4; a++) {
+            if (!GET_INT(env, addrt[a], &v))
+                return ESOCK_STR_EINVAL;
+            addr[a] = v;
+        }
+
+        sys_memcpy(inAddrP, &addr, sizeof(addr));
+        
+    }
+
+    return NULL;
+}
+
+
+
+/* +++ esock_encode_ip4_address +++
+ *
+ * Encode a IPv4 address:
+ *
+ *    + An ip4_address() (4 tuple)
+ *
+ * Note that this *only* decodes the "address" part of a
+ * (IPv4) socket address. There are several other things (port).
+ */
+
+extern
+char* esock_encode_ip4_address(ErlNifEnv*      env,
+                               struct in_addr* addrP,
+                               ERL_NIF_TERM*   eAddr)
+{
+    unsigned int   i;
+    ERL_NIF_TERM   at[4];
+    unsigned int   atLen = sizeof(at) / sizeof(ERL_NIF_TERM);
+    unsigned char* a     = (unsigned char*) addrP;
+    ERL_NIF_TERM   addr;
+    
+    /* The address */
+    for (i = 0; i < atLen; i++) {
+        at[i] = MKI(env, a[i]);
+    }
+
+    addr = MKTA(env, at, atLen);
+    UDBG( ("SUTIL", "esock_encode_ip4_address -> addr: %T\r\n", addr) );
+    // *eAddr = MKTA(env, at, atLen);
+    *eAddr = addr;
+    
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_ip6_address +++
+ *
+ * Decode a IPv6 address. This can be three things:
+ *
+ *    + Then atom 'any'
+ *    + Then atom 'loopback'
+ *    + An ip6_address() (8 tuple)
+ *
+ * Note that this *only* decodes the "address" part of a
+ * (IPv6) socket address. There are several other things
+ * (port, flowinfo and scope_id) that are handled elsewhere).
+ */
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_decode_ip6_address(ErlNifEnv*       env,
+                               ERL_NIF_TERM     eAddr,
+                               struct in6_addr* inAddrP)
+{
+    UDBG( ("SUTIL", "esock_decode_ip6_address -> entry with"
+           "\r\n   eAddr: %T"
+           "\r\n", eAddr) );
+
+    if (IS_ATOM(env, eAddr)) {
+        /* This is either 'any' or 'loopback' */
+        const struct in6_addr* addr;
+
+        if (COMPARE(esock_atom_loopback, eAddr) == 0) {
+            addr = &in6addr_loopback;
+        } else if (COMPARE(esock_atom_any, eAddr) == 0) {
+            addr = &in6addr_any;
+        } else {
+            return ESOCK_STR_EINVAL;
+        }
+        
+        *inAddrP = *addr;
+        
+    } else {
+        /* This is a 8-tuple */
+        
+        const ERL_NIF_TERM* addrt;
+        int                 addrtSz;
+        int                 ai, v;
+        unsigned char       addr[16];
+        unsigned char*      a = addr;
+        unsigned int        addrLen = sizeof(addr) / sizeof(unsigned char);
+        
+        if (!GET_TUPLE(env, eAddr, &addrtSz, &addrt))
+            return ESOCK_STR_EINVAL;
+        
+        if (addrtSz != 8)
+            return ESOCK_STR_EINVAL;
+        
+        for (ai = 0; ai < 8; ai++) {
+            if (!GET_INT(env, addrt[ai], &v))
+                return ESOCK_STR_EINVAL;
+            put_int16(v, a);
+            a += 2;
+        }
+        
+        sys_memcpy(inAddrP, &addr, addrLen);
+
+    }
+
+    return NULL;
+}
+#endif
+
+
+
+/* +++ esock_encode_ip6_address +++
+ *
+ * Encode a IPv6 address:
+ *
+ *    + An ip6_address() (8 tuple)
+ *
+ * Note that this *only* encodes the "address" part of a
+ * (IPv6) socket address. There are several other things
+ * (port, flowinfo and scope_id) that are handled elsewhere).
+ */
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_encode_ip6_address(ErlNifEnv*       env,
+                               struct in6_addr* addrP,
+                               ERL_NIF_TERM*    eAddr)
+{
+    unsigned int   i;
+    ERL_NIF_TERM   at[8];
+    unsigned int   atLen = sizeof(at) / sizeof(ERL_NIF_TERM);
+    unsigned char* a     = (unsigned char*) addrP;
+    
+    /* The address */
+    for (i = 0; i < atLen; i++) {
+        at[i] = MKI(env, get_int16(a + i*2));
+    }
+
+    *eAddr = MKTA(env, at, atLen);
+    
+    return NULL;
+}
+#endif
+
+
+
+/* +++ esock_encode_timeval +++
+ *
+ * Encode a timeval struct into its erlang form, a map with two fields:
+ *
+ *    sec
+ *    usec
+ *
+ */
+extern
+char* esock_encode_timeval(ErlNifEnv*      env,
+                           struct timeval* timeP,
+                           ERL_NIF_TERM*   eTime)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_sec, esock_atom_usec};
+    ERL_NIF_TERM vals[] = {MKL(env, timeP->tv_sec), MKL(env, timeP->tv_usec)};
+    
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, eTime))
+        return ESOCK_STR_EINVAL;
+
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_timeval +++
+ *
+ * Decode a timeval in its erlang form (a map) into its native form,
+ * a timeval struct.
+ *
+ */
+extern
+char* esock_decode_timeval(ErlNifEnv*      env,
+                           ERL_NIF_TERM    eTime,
+                           struct timeval* timeP)
+{
+    ERL_NIF_TERM eSec, eUSec;
+    size_t       sz;
+
+    // It must be a map
+    if (!IS_MAP(env, eTime))
+        return ESOCK_STR_EINVAL;
+
+    // It must have atleast two attributes
+    if (!enif_get_map_size(env, eTime, &sz) || (sz < 2))
+        return ESOCK_STR_EINVAL;
+
+    if (!GET_MAP_VAL(env, eTime, esock_atom_sec, &eSec))
+        return ESOCK_STR_EINVAL;
+
+    if (!GET_MAP_VAL(env, eTime, esock_atom_usec, &eUSec))
+        return ESOCK_STR_EINVAL;
+
+    if (!GET_LONG(env, eSec, &timeP->tv_sec))
+        return ESOCK_STR_EINVAL;
+    
+#if (SIZEOF_INT == 4)
+    {
+        int usec;
+        if (!GET_INT(env, eUSec, &usec))
+            return ESOCK_STR_EINVAL;
+        timeP->tv_usec = (typeof(timeP->tv_usec)) usec;
+    }
+#elif (SIZEOF_LONG == 4)
+    {
+        long usec;
+        if (!GET_LONG(env, eUSec, &usec))
+            return ESOCK_STR_EINVAL;
+        timeP->tv_usec = (typeof(timeP->tv_usec)) usec;
+    }
+#else
+    /* Ok, we give up... */
+    if (!GET_LONG(env, eUSec, &timeP->tv_usec))
+        return ESOCK_STR_EINVAL;
+
+#endif
+    
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_domain +++
+ *
+ * Decode the Erlang form of the 'domain' type, that is: 
+ * 
+ *    inet  => AF_INET
+ *    inet6 => AF_INET6
+ *    local => AF_UNIX
+ *
+ */
+extern
+char* esock_decode_domain(ErlNifEnv*   env,
+                          ERL_NIF_TERM eDomain,
+                          int*         domain)
+{
+    char* xres = NULL;
+
+    if (COMPARE(esock_atom_inet, eDomain) == 0) {
+        *domain = AF_INET;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    } else if (COMPARE(esock_atom_inet6, eDomain) == 0) {
+        *domain = AF_INET6;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+    } else if (COMPARE(esock_atom_local, eDomain) == 0) {
+        *domain = AF_UNIX;
+#endif
+
+    } else {
+        *domain = -1;
+        xres    = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_encode_domain +++
+ *
+ * Encode the native domain to the Erlang form, that is: 
+ * 
+ *    AF_INET  => inet
+ *    AF_INET6 => inet6
+ *    AF_UNIX  => local
+ *
+ */
+extern
+char* esock_encode_domain(ErlNifEnv*    env,
+                          int           domain,
+                          ERL_NIF_TERM* eDomain)
+{
+    char* xres = NULL;
+
+    switch (domain) {
+    case AF_INET:
+        *eDomain = esock_atom_inet;
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case AF_INET6:
+        *eDomain = esock_atom_inet6;
+        break;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+    case AF_UNIX:
+        *eDomain = esock_atom_local;
+        break;
+#endif
+
+    default:
+        *eDomain = esock_atom_undefined; // Just in case
+        xres     = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_type +++
+ *
+ * Decode the Erlang form of the 'type' type, that is: 
+ * 
+ *    stream    => SOCK_STREAM
+ *    dgram     => SOCK_DGRAM
+ *    raw       => SOCK_RAW
+ *    seqpacket => SOCK_SEQPACKET
+ *
+ */
+extern
+char* esock_decode_type(ErlNifEnv*   env,
+                        ERL_NIF_TERM eType,
+                        int*         type)
+{
+    char* xres = NULL;
+
+    if (COMPARE(esock_atom_stream, eType) == 0) {
+        *type = SOCK_STREAM;
+    } else if (COMPARE(esock_atom_dgram, eType) == 0) {
+        *type = SOCK_DGRAM;
+    } else if (COMPARE(esock_atom_raw, eType) == 0) {
+        *type = SOCK_RAW;
+
+#if defined(HAVE_SCTP)
+    } else if (COMPARE(esock_atom_seqpacket, eType) == 0) {
+        *type = SOCK_SEQPACKET;
+#endif
+
+    } else {
+        *type = -1;
+        xres  = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_type +++
+ *
+ * Encode the native type to the Erlang form, that is: 
+ * 
+ *    SOCK_STREAM    => stream
+ *    SOCK_DGRAM     => dgram
+ *    SOCK_RAW       => raw
+ *    SOCK_SEQPACKET => seqpacket
+ *
+ */
+extern
+char* esock_encode_type(ErlNifEnv*    env,
+                        int           type,
+                        ERL_NIF_TERM* eType)
+{
+    char* xres = NULL;
+
+    switch (type) {
+    case SOCK_STREAM:
+        *eType = esock_atom_stream;
+        break;
+
+    case SOCK_DGRAM:
+        *eType = esock_atom_dgram;
+        break;
+
+    case SOCK_RAW:
+        *eType = esock_atom_raw;
+        break;
+
+#if defined(HAVE_SCTP)
+    case SOCK_SEQPACKET:
+        *eType = esock_atom_seqpacket;
+        break;
+#endif
+
+    default:
+        *eType = esock_atom_undefined; // Just in case
+        xres   = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_encode_protocol +++
+ *
+ * Encode the native protocol to the Erlang form, that is: 
+ * 
+ *    SOL_IP | IPPROTO_IP => ip
+ *    SOL_IPV6            => ipv6
+ *    SOL_TCP             => tcp
+ *    SOL_UDP             => udp
+ *    SOL_SCTP            => sctp
+ *
+ */
+extern
+char* esock_encode_protocol(ErlNifEnv*    env,
+                            int           proto,
+                            ERL_NIF_TERM* eProto)
+{
+    char* xres = NULL;
+
+    switch (proto) {
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        *eProto = esock_atom_ip;
+        break;
+
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+        *eProto = esock_atom_ipv6;
+        break;
+#endif
+
+    case IPPROTO_TCP:
+        *eProto = esock_atom_tcp;
+        break;
+
+    case IPPROTO_UDP:
+        *eProto = esock_atom_udp;
+        break;
+
+#if defined(HAVE_SCTP)
+    case IPPROTO_SCTP:
+        *eProto = esock_atom_sctp;
+        break;
+#endif
+
+    default:
+        *eProto = esock_atom_undefined;
+        xres    = ESOCK_STR_EAFNOSUPPORT;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_protocol +++
+ *
+ * Decode the Erlang form of the 'protocol' type, that is: 
+ * 
+ *    ip   => SOL_IP | IPPROTO_IP
+ *    ipv6 => SOL_IPV6
+ *    tcp  => SOL_TCP
+ *    udp  => SOL_UDP
+ *    sctp => SOL_SCTP
+ *
+ */
+extern
+char* esock_decode_protocol(ErlNifEnv*   env,
+                            ERL_NIF_TERM eProto,
+                            int*         proto)
+{
+    char* xres = NULL;
+
+    if (COMPARE(esock_atom_ip, eProto) == 0) {
+#if defined(SOL_IP)
+        *proto = SOL_IP;
+#else
+        *proto = IPPROTO_IP;
+#endif
+    } else if (COMPARE(esock_atom_ipv6, eProto) == 0) {
+#if defined(SOL_IPV6)
+        *proto = SOL_IPV6;
+#else
+        *proto = IPPROTO_IPV6;
+#endif
+    } else if (COMPARE(esock_atom_tcp, eProto) == 0) {
+        *proto = IPPROTO_TCP;
+    } else if (COMPARE(esock_atom_udp, eProto) == 0) {
+        *proto = IPPROTO_UDP;
+#if defined(HAVE_SCTP)
+    } else if (COMPARE(esock_atom_sctp, eProto) == 0) {
+        *proto = IPPROTO_SCTP;
+#endif
+    } else {
+        *proto = -1;
+        xres   = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_bufsz +++
+ *
+ * Decode an buffer size. The size of a buffer is: 
+ * 
+ *    Sz > 0 => Use provided value
+ *    Sz     => Use provided default
+ *
+ */
+extern
+char* esock_decode_bufsz(ErlNifEnv*   env,
+                         ERL_NIF_TERM eVal,
+                         size_t       defSz,
+                         size_t*      sz)
+{
+    int val;
+
+    if (!GET_INT(env, eVal, &val))
+        return ESOCK_STR_EINVAL;
+
+    if (val > 0)
+        *sz = (size_t) val;
+    else
+        *sz = defSz;
+
+    return NULL;
+}
+
+
+
+/* *** esock_decode_string ***
+ *
+ * Decode a string value. A successful decode results in an 
+ * allocation of the string, which the caller has to free
+ * once the string has been used.
+ */
+extern
+BOOLEAN_T esock_decode_string(ErlNifEnv*         env,
+                              const ERL_NIF_TERM eString,
+                              char**             stringP)
+{
+    BOOLEAN_T    result;
+    unsigned int len;
+    char*        bufP;
+    
+    if (!GET_LIST_LEN(env, eString, &len) && (len != 0)) {
+        *stringP = NULL;
+        result   = FALSE;
+    } else {
+
+        UDBG( ("SUTIL", "esock_decode_string -> len: %d\r\n", len) );
+
+        bufP = MALLOC(len + 1); // We shall NULL-terminate
+    
+        if (GET_STR(env, eString, bufP, len+1)) {
+            UDBG( ("SUTIL", "esock_decode_string -> buf: %s\r\n", bufP) );
+            // bufP[len] = '\0';
+            *stringP = bufP;
+            result   = TRUE;
+        } else {
+            *stringP = NULL;
+            result   = FALSE;
+            FREE(bufP);
+        }
+    }
+
+    return result;
+}
+
+
+
+/* *** esock_extract_bool_from_map ***
+ *
+ * Extract an boolean item from a map.
+ *
+ */
+extern
+BOOLEAN_T esock_extract_bool_from_map(ErlNifEnv*   env,
+                                      ERL_NIF_TERM map,
+                                      ERL_NIF_TERM key,
+                                      BOOLEAN_T    def)
+{
+    ERL_NIF_TERM val;
+
+    if (!GET_MAP_VAL(env, map, key, &val))
+        return def;
+
+    if (!IS_ATOM(env, val))
+        return def;
+
+    if (COMPARE(val, esock_atom_true) == 0)
+        return TRUE;
+    else
+        return FALSE;
+}
+
+
+
+/* *** esock_decode_bool ***
+ *
+ * Decode a boolean value.
+ *
+ */
+extern
+BOOLEAN_T esock_decode_bool(ERL_NIF_TERM val)
+{
+    if (COMPARE(esock_atom_true, val) == 0) 
+        return TRUE;
+    else
+        return FALSE;
+}
+
+
+/* *** esock_encode_bool ***
+ *
+ * Encode a boolean value.
+ *
+ */
+extern
+ERL_NIF_TERM esock_encode_bool(BOOLEAN_T val)
+{
+    if (val)
+        return esock_atom_true;
+    else
+        return esock_atom_false;
+}
+
+
+/* Create an ok two (2) tuple in the form:
+ *
+ *         {ok, Any}
+ *
+ * The second element (Any) is already in the form of an
+ * ERL_NIF_TERM so all we have to do is create the tuple.
+ */
+extern
+ERL_NIF_TERM esock_make_ok2(ErlNifEnv* env, ERL_NIF_TERM any)
+{
+    return MKT2(env, esock_atom_ok, any);
+}
+
+
+/* Create an ok three (3) tuple in the form:
+ *
+ *         {ok, Val1, Val2}
+ *
+ * The second (Val1) and third (Val2) elements are already in
+ * the form of an ERL_NIF_TERM so all we have to do is create
+ * the tuple.
+ */
+extern
+ERL_NIF_TERM esock_make_ok3(ErlNifEnv* env, ERL_NIF_TERM val1, ERL_NIF_TERM val2)
+{
+  return MKT3(env, esock_atom_ok, val1, val2);
+}
+
+
+
+/* Create an error two (2) tuple in the form:
+ *
+ *          {error, Reason}
+ *
+ * The second element (Reason) is already in the form of an
+ * ERL_NIF_TERM so all we have to do is create the tuple.
+ */
+extern
+ERL_NIF_TERM esock_make_error(ErlNifEnv* env, ERL_NIF_TERM reason)
+{
+    return MKT2(env, esock_atom_error, reason);
+}
+
+
+
+/* Create an error two (2) tuple in the form: {error, Reason}.
+ *
+ *          {error, Reason}
+ *
+ * The second element, Reason, is the reason string that has
+ * converted into an atom.
+ */
+extern
+ERL_NIF_TERM esock_make_error_str(ErlNifEnv* env, char* reason)
+{
+    return esock_make_error(env, MKA(env, reason));
+}
+
+
+/* Create an error two (2) tuple in the form:
+ *
+ *          {error, Reason}
+ *
+ * The second element, Reason, is the errno value in its
+ * basic form (integer) which has been converted into an atom.
+ */
+extern
+ERL_NIF_TERM esock_make_error_errno(ErlNifEnv* env, int err)
+{
+    return esock_make_error_str(env, erl_errno_id(err));
+}
+
+
+
+/* strnlen doesn't exist everywhere */
+extern
+size_t esock_strnlen(const char *s, size_t maxlen)
+{
+    size_t i = 0;
+    while (i < maxlen && s[i] != '\0')
+        i++;
+    return i;
+}
+
+
+
+/* *** esock_abort ***
+ *
+ * Generate an abort with "extra" info. This should be called
+ * via the ESOCK_ABORT macro.
+ * Basically it prints the extra info onto stderr before aborting.
+ *
+ */
+extern
+void esock_abort(const char* expr,
+                 const char* func,
+                 const char* file,
+                 int         line)
+{
+  fflush(stdout);
+  fprintf(stderr, "%s:%d:%s() Assertion failed: %s\n",
+	  file, line, func, expr);
+  fflush(stderr);
+  abort();
+}
+
+
+
+/* *** esock_warning_msg ***
+ *
+ * Temporary function for issuing warning messages.
+ *
+ */
+extern
+void esock_warning_msg( const char* format, ... )
+{
+  va_list         args;
+  char            f[512 + sizeof(format)]; // This has to suffice...
+  char            stamp[64]; // Just in case...
+  int             res;
+
+  /*
+   * We should really include self in the printout,
+   * so we can se which process are executing the code.
+   * But then I must change the API....something for later.
+   */
+
+  // 2018-06-29 12:13:21.232089
+  // 29-Jun-2018::13:47:25.097097
+
+  if (esock_timestamp(stamp, sizeof(stamp))) {
+      res = enif_snprintf(f, sizeof(f),
+                          "=WARNING MSG==== %s ===\r\n%s",
+                          stamp, format);
+  } else {
+      res = enif_snprintf(f, sizeof(f), "=WARNING MSG==== %s", format);
+  }
+
+  if (res > 0) {
+      va_start (args, format);
+      enif_vfprintf (stdout, f, args);
+      va_end (args);
+      fflush(stdout);
+  }
+
+  return;
+}
+
+
+/* *** esock_timestamp ***
+ *
+ * Create a timestamp string.
+ * If awailable, we use the localtime_r and strftime function(s)
+ * to produces a nice readable timestamp. But if not (awailable),
+ * it produces a timestamp in the form of an "Epoch" (A real epoch
+ * is the number of seconds since 1/1 1970, but our timestamp is
+ * the number micro seconds since 1/1 1970).
+ */
+
+extern
+BOOLEAN_T esock_timestamp(char *buf, unsigned int len)
+{
+    int        ret;
+    ErlNifTime monTime = enif_monotonic_time(ERL_NIF_USEC);
+    ErlNifTime offTime = enif_time_offset(ERL_NIF_USEC);
+    ErlNifTime time    = monTime + offTime;
+#if defined(ESOCK_USE_PRETTY_TIMESTAMP)
+    time_t     sec     = time / 1000000; // (if _MSEC) sec  = time / 1000;
+    time_t     usec    = time % 1000000; // (if _MSEC) msec = time % 1000;
+    int        buflen;
+    struct tm  t;
+
+    if (localtime_r(&sec, &t) == NULL)
+        return FALSE;
+
+    ret = strftime(buf, len, "%d-%B-%Y::%T", &t);
+    if (ret == 0)
+        return FALSE;
+    len -= ret - 1;
+    buflen = strlen(buf);
+
+    ret = enif_snprintf(&buf[buflen], len, ".%06b64d", usec);
+    if (ret >= len)
+        return FALSE;
+
+    return TRUE;
+#else
+    ret = enif_snprintf(buf, len, "%b64d", time);
+    if (ret == 0)
+        return FALSE;
+    else
+        return TRUE;
+#endif
+}
+
+
+
+/* =================================================================== *
+ *                                                                     *
+ *              Various (internal) utility functions                   *
+ *                                                                     *
+ * =================================================================== */
+
+/* Construct the IPv4 socket address */
+static
+char* make_sockaddr_in4(ErlNifEnv*    env,
+                        ERL_NIF_TERM  port,
+                        ERL_NIF_TERM  addr,
+                        ERL_NIF_TERM* sa)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_family, esock_atom_port, esock_atom_addr};
+    ERL_NIF_TERM vals[] = {esock_atom_inet, port, addr};
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, sa)) {
+        *sa = esock_atom_undefined;
+        return ESOCK_STR_EINVAL;
+    } else {
+        return NULL;
+    }
+}
+
+
+/* Construct the IPv6 socket address */
+static
+char* make_sockaddr_in6(ErlNifEnv*    env,
+                        ERL_NIF_TERM  port,
+                        ERL_NIF_TERM  addr,
+                        ERL_NIF_TERM  flowInfo,
+                        ERL_NIF_TERM  scopeId,
+                        ERL_NIF_TERM* sa)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_family,
+                           esock_atom_port,
+                           esock_atom_addr,
+                           esock_atom_flowinfo,
+                           esock_atom_scope_id};
+    ERL_NIF_TERM vals[] = {esock_atom_inet6, port, addr, flowInfo, scopeId};
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, sa)) {
+        *sa = esock_atom_undefined;
+        return ESOCK_STR_EINVAL;
+    } else {
+        return NULL;
+    }
+}
+
+
+/* Construct the Unix Domain socket address */
+static
+char* make_sockaddr_un(ErlNifEnv*    env,
+                       ERL_NIF_TERM  path,
+                       ERL_NIF_TERM* sa)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_family, esock_atom_path};
+    ERL_NIF_TERM vals[] = {esock_atom_local,  path};
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, sa)) {
+        *sa = esock_atom_undefined;
+        return ESOCK_STR_EINVAL;
+    } else {
+        return NULL;
+    }
+}
+
+
diff --git a/erts/emulator/nifs/common/socket_util.h b/erts/emulator/nifs/common/socket_util.h
new file mode 100644
index 0000000000..2688a920c4
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_util.h
@@ -0,0 +1,208 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Utility "stuff" for socket and net.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#ifndef SOCKET_UTIL_H__
+#define SOCKET_UTIL_H__
+
+#include <erl_nif.h>
+#include "socket_int.h"
+
+#define CHAR(C)  ((char) (C))
+#define UCHAR(C) ((unsigned char) (C))
+#define INT(I)   ((int)   (I))
+#define UINT(U)  ((unsigned int) (U))
+#define LONG(L)  ((long) (L))
+#define ULONG(L) ((unsigned long) (L))
+#define SZT(I)   ((size_t) (I))
+#define VOIDP(P) ((void*) (P))
+#define CHARP(P) ((char*) (P))
+
+#define ESOCK_ABORT(E)  esock_abort(E, __func__, __FILE__, __LINE__)
+#define ESOCK_ASSERT(e) ((void) ((e) ? 1 : (ESOCK_ABORT(#e), 0)))
+
+extern
+char* esock_encode_iov(ErlNifEnv*    env,
+                       int           read,
+                       struct iovec* iov,
+                       size_t        len,
+                       ErlNifBinary* data,
+                       ERL_NIF_TERM* eIOV);
+extern
+char* esock_decode_iov(ErlNifEnv*    env,
+                       ERL_NIF_TERM  eIOV,
+                       ErlNifBinary* bufs,
+                       struct iovec* iov,
+                       size_t        len,
+                       ssize_t*      totSize);
+extern
+char* esock_decode_sockaddr(ErlNifEnv*    env,
+                            ERL_NIF_TERM  eSockAddr,
+                            ESockAddress* sockAddrP,
+                            unsigned int* addrLen);
+extern
+char* esock_encode_sockaddr(ErlNifEnv*    env,
+                            ESockAddress* sockAddrP,
+                            unsigned int  addrLen,
+                            ERL_NIF_TERM* eSockAddr);
+
+extern
+char* esock_decode_sockaddr_in4(ErlNifEnv*          env,
+                                ERL_NIF_TERM        eSockAddr,
+                                struct sockaddr_in* sockAddrP,
+                                unsigned int*       addrLen);
+extern
+char* esock_encode_sockaddr_in4(ErlNifEnv*          env,
+                                struct sockaddr_in* sockAddrP,
+                                unsigned int        addrLen,
+                                ERL_NIF_TERM*       eSockAddr);
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_decode_sockaddr_in6(ErlNifEnv*           env,
+                                ERL_NIF_TERM         eSockAddr,
+                                struct sockaddr_in6* sockAddrP,
+                                unsigned int*        addrLen);
+extern
+char* esock_encode_sockaddr_in6(ErlNifEnv*           env,
+                                struct sockaddr_in6* sockAddrP,
+                                unsigned int         addrLen,
+                                ERL_NIF_TERM*        eSockAddr);
+#endif
+
+#ifdef HAVE_SYS_UN_H
+extern
+char* esock_decode_sockaddr_un(ErlNifEnv*          env,
+                               ERL_NIF_TERM        eSockAddr,
+                               struct sockaddr_un* sockAddrP,
+                               unsigned int*       addrLen);
+extern
+char* esock_encode_sockaddr_un(ErlNifEnv*          env,
+                               struct sockaddr_un* sockAddrP,
+                               unsigned int        addrLen,
+                               ERL_NIF_TERM*       eSockAddr);
+#endif
+
+extern
+char* esock_decode_ip4_address(ErlNifEnv*      env,
+                               ERL_NIF_TERM    eAddr,
+                               struct in_addr* inAddrP);
+extern
+char* esock_encode_ip4_address(ErlNifEnv*      env,
+                               struct in_addr* addrP,
+                               ERL_NIF_TERM*   eAddr);
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_decode_ip6_address(ErlNifEnv*       env,
+                               ERL_NIF_TERM     eAddr,
+                               struct in6_addr* inAddrP);
+extern
+char* esock_encode_ip6_address(ErlNifEnv*       env,
+                               struct in6_addr* addrP,
+                               ERL_NIF_TERM*    eAddr);
+#endif
+
+extern char* esock_encode_timeval(ErlNifEnv*      env,
+                                  struct timeval* timeP,
+                                  ERL_NIF_TERM*   eTime);
+extern char* esock_decode_timeval(ErlNifEnv*      env,
+                                  ERL_NIF_TERM    eTime,
+                                  struct timeval* timeP);
+extern
+char* esock_decode_domain(ErlNifEnv*   env,
+                          ERL_NIF_TERM eDomain,
+                          int*         domain);
+extern
+char* esock_encode_domain(ErlNifEnv*    env,
+                          int           domain,
+                          ERL_NIF_TERM* eDomain);
+
+extern
+char* esock_decode_type(ErlNifEnv*   env,
+                        ERL_NIF_TERM eType,
+                        int*         type);
+extern
+char* esock_encode_type(ErlNifEnv*    env,
+                        int           type,
+                        ERL_NIF_TERM* eType);
+
+extern
+char* esock_decode_protocol(ErlNifEnv*   env,
+                            ERL_NIF_TERM eProtocol,
+                            int*         protocol);
+extern
+char* esock_encode_protocol(ErlNifEnv*    env,
+                            int           type,
+                            ERL_NIF_TERM* eProtocol);
+
+extern
+char* esock_decode_bufsz(ErlNifEnv*   env,
+                         ERL_NIF_TERM eVal,
+                         size_t       defSz,
+                         size_t*      sz);
+
+extern
+BOOLEAN_T esock_decode_string(ErlNifEnv*         env,
+                              const ERL_NIF_TERM eString,
+                              char**             stringP);
+
+extern
+BOOLEAN_T esock_extract_bool_from_map(ErlNifEnv*   env,
+                                      ERL_NIF_TERM map,
+                                      ERL_NIF_TERM key,
+                                      BOOLEAN_T    def);
+extern
+BOOLEAN_T esock_decode_bool(ERL_NIF_TERM val);
+extern
+ERL_NIF_TERM esock_encode_bool(BOOLEAN_T val);
+
+extern
+size_t esock_strnlen(const char *s, size_t maxlen);
+extern
+void esock_abort(const char* expr,
+                 const char* func,
+                 const char* file,
+                 int         line);
+
+extern
+ERL_NIF_TERM esock_make_ok2(ErlNifEnv* env, ERL_NIF_TERM any);
+extern
+ERL_NIF_TERM esock_make_ok3(ErlNifEnv* env, ERL_NIF_TERM val1, ERL_NIF_TERM val2);
+
+extern
+ERL_NIF_TERM esock_make_error(ErlNifEnv* env, ERL_NIF_TERM reason);
+extern
+ERL_NIF_TERM esock_make_error_str(ErlNifEnv* env, char* reason);
+extern
+ERL_NIF_TERM esock_make_error_errno(ErlNifEnv* env, int err);
+
+extern
+BOOLEAN_T esock_timestamp(char *buf, unsigned int len);
+
+extern
+void esock_warning_msg(const char* format, ... );
+
+
+#endif // SOCKET_UTIL_H__
diff --git a/erts/emulator/nifs/win32/win_prim_file.c b/erts/emulator/nifs/win32/win_prim_file.c
index d0aa70542f..e7d3924240 100644
--- a/erts/emulator/nifs/win32/win_prim_file.c
+++ b/erts/emulator/nifs/win32/win_prim_file.c
@@ -142,12 +142,15 @@ static posix_errno_t get_full_path(ErlNifEnv *env, WCHAR *input, efile_path_t *r
         maybe_unc_path = !sys_memcmp(result->data, L"\\\\", sizeof(WCHAR) * 2);
 
         if(maybe_unc_path && !is_long_path) {
-            /* \\localhost\c$\gurka -> \\?\UNC\localhost\c$\gurka */
+            /* \\localhost\c$\gurka -> \\?\UNC\localhost\c$\gurka
+             *
+             * Note that the length is reduced by 2 as the "\\" is replaced by
+             * the UNC prefix */
             sys_memmove(result->data + LP_UNC_PREFIX_SIZE,
                 &((WCHAR*)result->data)[2],
-                (actual_length - 1) * sizeof(WCHAR));
+                (actual_length + 1 - 2) * sizeof(WCHAR));
             sys_memcpy(result->data, LP_UNC_PREFIX, LP_UNC_PREFIX_SIZE);
-            actual_length += LP_UNC_PREFIX_LENGTH;
+            actual_length += LP_UNC_PREFIX_LENGTH - 2;
         } else if(!is_long_path) {
             /* C:\gurka -> \\?\C:\gurka */
             sys_memmove(result->data + LP_PREFIX_SIZE, result->data,
diff --git a/erts/emulator/pcre/LICENCE b/erts/emulator/pcre/LICENCE
index f6ef7fd766..760a6666b6 100644
--- a/erts/emulator/pcre/LICENCE
+++ b/erts/emulator/pcre/LICENCE
@@ -25,7 +25,7 @@ Email domain:     cam.ac.uk
 University of Cambridge Computing Service,
 Cambridge, England.
 
-Copyright (c) 1997-2018 University of Cambridge
+Copyright (c) 1997-2019 University of Cambridge
 All rights reserved.
 
 
@@ -34,9 +34,9 @@ PCRE JUST-IN-TIME COMPILATION SUPPORT
 
 Written by:       Zoltan Herczeg
 Email local part: hzmester
-Emain domain:     freemail.hu
+Email domain:     freemail.hu
 
-Copyright(c) 2010-2018 Zoltan Herczeg
+Copyright(c) 2010-2019 Zoltan Herczeg
 All rights reserved.
 
 
@@ -45,9 +45,9 @@ STACK-LESS JUST-IN-TIME COMPILER
 
 Written by:       Zoltan Herczeg
 Email local part: hzmester
-Emain domain:     freemail.hu
+Email domain:     freemail.hu
 
-Copyright(c) 2009-2018 Zoltan Herczeg
+Copyright(c) 2009-2019 Zoltan Herczeg
 All rights reserved.
 
 
diff --git a/erts/emulator/pcre/pcre-8.42.tar.bz2 b/erts/emulator/pcre/pcre-8.42.tar.bz2
deleted file mode 100644
index 61bfa38970..0000000000
--- a/erts/emulator/pcre/pcre-8.42.tar.bz2
+++ /dev/null
diff --git a/erts/emulator/pcre/pcre-8.43.tar.bz2 b/erts/emulator/pcre/pcre-8.43.tar.bz2
new file mode 100644
index 0000000000..e20c601f71
--- /dev/null
+++ b/erts/emulator/pcre/pcre-8.43.tar.bz2
diff --git a/erts/emulator/pcre/pcre.h b/erts/emulator/pcre/pcre.h
index 3563791223..49c9fc6dc8 100644
--- a/erts/emulator/pcre/pcre.h
+++ b/erts/emulator/pcre/pcre.h
@@ -43,9 +43,9 @@ POSSIBILITY OF SUCH DAMAGE.
 /* The current PCRE version information. */
 
 #define PCRE_MAJOR          8
-#define PCRE_MINOR          42
+#define PCRE_MINOR          43
 #define PCRE_PRERELEASE     
-#define PCRE_DATE           2018-03-20
+#define PCRE_DATE           2019-02-23
 
 /* When an application links to a PCRE DLL in Windows, the symbols that are
 imported have to be identified as such. When building PCRE, the appropriate
@@ -240,6 +240,9 @@ with J. */
 #define PCRE_UTF8_ERR20             20
 #define PCRE_UTF8_ERR21             21
 #define PCRE_UTF8_ERR22             22  /* Unused (was non-character) */
+#if defined(ERLANG_INTEGRATION)
+#define PCRE_UTF8_YIELD             23
+#endif
 
 /* Specific error codes for UTF-16 validity checks */
 
diff --git a/erts/emulator/pcre/pcre_compile.c b/erts/emulator/pcre/pcre_compile.c
index ae7f6e2a2a..6ac222b27e 100644
--- a/erts/emulator/pcre/pcre_compile.c
+++ b/erts/emulator/pcre/pcre_compile.c
@@ -6,7 +6,7 @@
 and semantics are as close as possible to those of the Perl 5 language.
 
                        Written by Philip Hazel
-           Copyright (c) 1997-2016 University of Cambridge
+           Copyright (c) 1997-2018 University of Cambridge
 
 -----------------------------------------------------------------------------
 Redistribution and use in source and binary forms, with or without
@@ -3300,7 +3300,7 @@ for(;;)
       if ((*xclass_flags & XCL_MAP) == 0)
         {
         /* No bits are set for characters < 256. */
-        if (list[1] == 0) return TRUE;
+        if (list[1] == 0) return (*xclass_flags & XCL_NOT) == 0;
         /* Might be an empty repeat. */
         continue;
         }
@@ -7643,6 +7643,8 @@ for (;; ptr++)
         /* Can't determine a first byte now */
 
         if (firstcharflags == REQ_UNSET) firstcharflags = REQ_NONE;
+        zerofirstchar = firstchar;
+        zerofirstcharflags = firstcharflags;
         continue;
 
 
@@ -8683,10 +8685,18 @@ do {
      if (!is_anchored(scode, new_map, cd, atomcount)) return FALSE;
      }
 
-   /* Positive forward assertions and conditions */
+   /* Positive forward assertion */
 
-   else if (op == OP_ASSERT || op == OP_COND)
+   else if (op == OP_ASSERT)
+     {
+     if (!is_anchored(scode, bracket_map, cd, atomcount)) return FALSE;
+     }
+
+   /* Condition; not anchored if no second branch */
+
+   else if (op == OP_COND)
      {
+     if (scode[GET(scode,1)] != OP_ALT) return FALSE;
      if (!is_anchored(scode, bracket_map, cd, atomcount)) return FALSE;
      }
 
diff --git a/erts/emulator/pcre/pcre_exec.c b/erts/emulator/pcre/pcre_exec.c
index 1946e97a72..55a7b377bf 100644
--- a/erts/emulator/pcre/pcre_exec.c
+++ b/erts/emulator/pcre/pcre_exec.c
@@ -6642,10 +6642,16 @@ typedef struct {
     REAL_PCRE *Xre;
     heapframe Xframe_zero; /* Always NO_RECURSE */
 
+    /* for yield in valid_utf() */
+
+    struct PRIV(valid_utf_ystate) valid_utf_ystate;
+    
     /* Original function parameters that need be saved */
     int Xstart_offset;
     int Xoffsetcount;
     int *Xoffsets;
+    int Xlength;
+    PCRE_SPTR Xsubject;
 } PcreExecContext;
 #endif  
    
@@ -6675,6 +6681,7 @@ pcre32_exec(const pcre32 *argument_re, const pcre32_extra *extra_data,
 #endif
 {
 #ifndef ERLANG_INTEGRATION
+#define ERTS_UPDATE_CONSUMED(X, MD)
 int rc, ocount, arg_offset_max;
 int newline;
 BOOL using_temporary_offsets = FALSE;
@@ -6736,6 +6743,8 @@ heapframe frame_zero;
   start_offset = exec_context->Xstart_offset;   \
   offsetcount = exec_context->Xoffsetcount;     \
   offsets = exec_context->Xoffsets;             \
+  length = exec_context->Xlength;               \
+  subject = exec_context->Xsubject;             \
 } while (0)
 
 #define SWAPOUT() do {				\
@@ -6750,8 +6759,30 @@ heapframe frame_zero;
   exec_context->Xstart_offset = start_offset;   \
   exec_context->Xoffsetcount = offsetcount;     \
   exec_context->Xoffsets = offsets;             \
+  exec_context->Xlength = length;               \
+  exec_context->Xsubject = subject;             \
 } while (0)
 
+#define ERTS_UPDATE_CONSUMED(X, MD)                                 \
+do {                                                                \
+    if (((X)->flags & PCRE_EXTRA_LOOP_LIMIT) != 0) {                \
+        unsigned long consumed__;                                   \
+        if (!(X)->restart_data) {                                   \
+            consumed__ = 0;                                         \
+        }                                                           \
+        else {                                                      \
+            PcreExecContext *ctx__ = (PcreExecContext *)            \
+                (*(X)->restart_data);                               \
+            consumed__ = ctx__->valid_utf_ystate.cnt;               \
+            ctx__->valid_utf_ystate.cnt = 0;                        \
+        }                                                           \
+        if ((MD)) {                                                 \
+            match_data *md__ = (MD);                                \
+            consumed__ += (X)->loop_limit - md__->loop_limit;       \
+        }                                                           \
+        *((X)->loop_counter_return) = consumed__;                   \
+    }                                                               \
+} while (0)
 PcreExecContext *exec_context;
 PcreExecContext internal_context;
 
@@ -6776,15 +6807,21 @@ pcre_uchar req_char;
      /* we are restarting, every initialization is skipped and we jump directly into the loop */
    exec_context = (PcreExecContext *) *(extra_data->restart_data);
    SWAPIN();
-
+   if (exec_context->valid_utf_ystate.yielded)
+       goto restart_valid_utf;
    goto RESTART_INTERRUPTED;
  } else {
    if (extra_data != NULL && 
        (extra_data->flags & PCRE_EXTRA_LOOP_LIMIT)) {
      exec_context = (PcreExecContext *) (erts_pcre_malloc)(sizeof(PcreExecContext));
-     *(extra_data->restart_data) = (void *) exec_context; 
+     *(extra_data->restart_data) = (void *) exec_context;
+     exec_context->valid_utf_ystate.yielded = 0;
      /* need freeing by special routine from client */
    } else {
+#if defined(ERLANG_INTEGRATION)
+     fprintf(stderr, "Unexpected execution path\n");
+     abort();
+#endif
      exec_context = &internal_context;
    }
    
@@ -6865,9 +6902,38 @@ code for an invalid string if a results vector is available. */
 if (utf && (options & PCRE_NO_UTF8_CHECK) == 0)
   {
   int erroroffset;
-  int errorcode = PRIV(valid_utf)((PCRE_PUCHAR)subject, length, &erroroffset);
+  int errorcode;
+
+#if !defined(ERLANG_INTEGRATION)
+  errorcode = PRIV(valid_utf)((PCRE_PUCHAR)subject, length);
+#else
+  struct PRIV(valid_utf_ystate) *ystate;
+  
+  if (!extra_data || !extra_data->restart_data) {
+      ystate = NULL;
+  }
+  else if (!(extra_data->flags & PCRE_EXTRA_LOOP_LIMIT)) {
+      exec_context->valid_utf_ystate.cnt = 10;
+      ystate = NULL;
+  }
+  else {
+      exec_context->valid_utf_ystate.yielded = 0;
+  restart_valid_utf:
+      ystate = &exec_context->valid_utf_ystate;
+      ystate->cnt = (int) extra_data->loop_limit;
+  }
+  errorcode = PRIV(yielding_valid_utf)((PCRE_PUCHAR)subject, length,
+                                       &erroroffset, ystate);
+#endif
   if (errorcode != 0)
     {
+#if defined(ERLANG_INTEGRATION)
+    if (ystate && ystate->yielded) {
+        ERTS_UPDATE_CONSUMED(extra_data, NULL);
+        SWAPOUT();
+        return PCRE_ERROR_LOOP_LIMIT;
+    }
+#endif
     if (offsetcount >= 2)
       {
       offsets[0] = erroroffset;
@@ -6890,6 +6956,11 @@ if (utf && (options & PCRE_NO_UTF8_CHECK) == 0)
     return PCRE_ERROR_BADUTF8_OFFSET;
 #endif
   }
+#if defined(ERLANG_INTEGRATION)
+else {
+    exec_context->valid_utf_ystate.cnt = 0;
+}
+#endif
 #endif
 
 /* If the pattern was successfully studied with JIT support, run the JIT
@@ -6950,7 +7021,11 @@ if (extra_data != NULL)
 #ifdef ERLANG_INTEGRATION
   if ((flags & PCRE_EXTRA_LOOP_LIMIT) != 0) 
     {
-    md->loop_limit = extra_data->loop_limit;
+        md->loop_limit = extra_data->loop_limit;
+        if (extra_data->restart_data)
+          md->loop_limit -= extra_data->loop_limit - exec_context->valid_utf_ystate.cnt;
+        if (md->loop_limit < 10)
+            md->loop_limit = 10; /* At least do something if we've come this far... */
     }
 #endif
   }
@@ -7266,14 +7341,8 @@ for(;;)
 #endif
         if ((start_bits[c/8] & (1 << (c&7))) != 0)
 	  {
-#ifdef ERLANG_INTEGRATION
-          if ((extra_data->flags & PCRE_EXTRA_LOOP_LIMIT) != 0) 
-            {
-            *extra_data->loop_counter_return = 
-               (extra_data->loop_limit - md->loop_limit);
-            }
-#endif
-          break;
+              ERTS_UPDATE_CONSUMED(extra_data, md);
+              break;
 	  }
         start_match++;
         }
@@ -7298,13 +7367,7 @@ for(;;)
         (pcre_uint32)(end_subject - start_match) < study->minlength)
       {
       rc = MATCH_NOMATCH;
-#ifdef ERLANG_INTEGRATION
-      if ((extra_data->flags & PCRE_EXTRA_LOOP_LIMIT) != 0) 
- 	{
- 	*extra_data->loop_counter_return = 
- 	  (extra_data->loop_limit - md->loop_limit);
-        }
-#endif
+      ERTS_UPDATE_CONSUMED(extra_data, md);
       break;
       }
 
@@ -7353,13 +7416,7 @@ for(;;)
         if (p >= end_subject)
           {
           rc = MATCH_NOMATCH;
-#ifdef ERLANG_INTEGRATION
-	if ((extra_data->flags & PCRE_EXTRA_LOOP_LIMIT) != 0) 
-	  {
-	  *extra_data->loop_counter_return = 
-	    (extra_data->loop_limit - md->loop_limit);
-          }
-#endif
+          ERTS_UPDATE_CONSUMED(extra_data, md);
           break;
           }
 
@@ -7390,11 +7447,7 @@ for(;;)
   EDEBUGF(("Calling match..."));
   rc = match(start_match, md->start_code, start_match, 2, md, NULL, 0);
 #ifdef ERLANG_INTEGRATION
-  if ((extra_data->flags & PCRE_EXTRA_LOOP_LIMIT) != 0) 
-    {
-    *extra_data->loop_counter_return = 
-       (extra_data->loop_limit - md->loop_limit);
-    }
+  ERTS_UPDATE_CONSUMED(extra_data, md);
   SWAPOUT();
   while(rc == PCRE_ERROR_LOOP_LIMIT) {
       EDEBUGF(("Loop limit break detected"));
diff --git a/erts/emulator/pcre/pcre_internal.h b/erts/emulator/pcre/pcre_internal.h
index c84dcb5a38..71f473e86f 100644
--- a/erts/emulator/pcre/pcre_internal.h
+++ b/erts/emulator/pcre/pcre_internal.h
@@ -2756,6 +2756,17 @@ extern int               PRIV(strcmp_uc_c8_utf)(const pcre_uchar *,
 
 #endif /* COMPILE_PCRE[8|16|32] */
 
+#if defined(ERLANG_INTEGRATION)
+struct PRIV(valid_utf_ystate) {
+    unsigned int cnt;
+    int length;
+    int yielded;
+    PCRE_PUCHAR p;
+};
+extern int               PRIV(yielding_valid_utf)(PCRE_PUCHAR, int, int *,
+                                                  struct PRIV(valid_utf_ystate) *);
+#endif
+                                               
 extern const pcre_uchar *PRIV(find_bracket)(const pcre_uchar *, BOOL, int);
 extern BOOL              PRIV(is_newline)(PCRE_PUCHAR, int, PCRE_PUCHAR,
                            int *, BOOL);
diff --git a/erts/emulator/pcre/pcre_jit_compile.c b/erts/emulator/pcre/pcre_jit_compile.c
index 926e40f6d3..2d2288f81e 100644
--- a/erts/emulator/pcre/pcre_jit_compile.c
+++ b/erts/emulator/pcre/pcre_jit_compile.c
@@ -9002,7 +9002,7 @@ if (exact > 1)
 #ifdef SUPPORT_UTF
       && !common->utf
 #endif
-      )
+      && type != OP_ANYNL && type != OP_EXTUNI)
     {
     OP2(SLJIT_ADD, TMP1, 0, STR_PTR, 0, SLJIT_IMM, IN_UCHARS(exact));
     add_jump(compiler, &backtrack->topbacktracks, CMP(SLJIT_GREATER, TMP1, 0, STR_END, 0));
diff --git a/erts/emulator/pcre/pcre_valid_utf8.c b/erts/emulator/pcre/pcre_valid_utf8.c
index 516d8f4725..1dc1f9ba0c 100644
--- a/erts/emulator/pcre/pcre_valid_utf8.c
+++ b/erts/emulator/pcre/pcre_valid_utf8.c
@@ -107,19 +107,80 @@ Returns:       = 0    if the string is a valid UTF-8 string
 int
 PRIV(valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset)
 {
+
+#if defined(ERLANG_INTEGRATION)
+    return PRIV(yielding_valid_utf)(string, length, erroroffset, NULL);
+}
+
+int
+PRIV(yielding_valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset, struct PRIV(valid_utf_ystate) *ystate)
+{
+#endif
+
 #ifdef SUPPORT_UTF
 register PCRE_PUCHAR p;
 
+#if defined(ERLANG_INTEGRATION)
+register long cnt;
+
+if (!ystate) {
+    cnt = -1;
+}
+else {
+    cnt = ystate->cnt;
+    if (ystate->yielded) {
+        p = ystate->p;
+        length = ystate->length;
+        if (length < 0) 
+            goto restart_length;
+        else
+            goto restart_validate;
+    }
+}
+#endif
+
 if (length < 0)
   {
-  for (p = string; *p != 0; p++);
-  length = (int)(p - string);
+      for (p = string; *p != 0; p++) {
+#if defined(ERLANG_INTEGRATION)
+          if (cnt > 0 && --cnt == 0) {
+              /*
+               * Return with cnt set to amount consumed;
+               * i.e. same amount as at start...
+               */
+              ystate->yielded = !0;
+              ystate->length = length;
+              ystate->p = p;
+              return PCRE_UTF8_YIELD;
+          }
+      restart_length:
+          (void) !0;
+#endif
+      }
+      length = (int)(p - string);
   }
 
 for (p = string; length-- > 0; p++)
   {
   register pcre_uchar ab, c, d;
 
+#if defined(ERLANG_INTEGRATION)
+
+  if (cnt > 0 && --cnt == 0) {
+      /*
+       * Return with cnt set to amount consumed;
+       * i.e. same amount as at start...
+       */
+      ystate->yielded = !0;
+      ystate->length = length;
+      ystate->p = p;
+      return PCRE_UTF8_YIELD;
+  }
+  
+  restart_validate:
+
+#endif
+  
   c = *p;
   if (c < 128) continue;                /* ASCII character */
 
@@ -290,6 +351,14 @@ for (p = string; length-- > 0; p++)
     }
   }
 
+#if defined(ERLANG_INTEGRATION)
+if (ystate) {
+    /* Return with cnt set to amount consumed... */
+    ystate->cnt -= cnt;
+    ystate->yielded = 0;
+}
+#endif
+
 #else  /* Not SUPPORT_UTF */
 (void)(string);  /* Keep picky compilers happy */
 (void)(length);
diff --git a/erts/emulator/sys/common/erl_check_io.c b/erts/emulator/sys/common/erl_check_io.c
index c681fa481f..fb18c837ab 100644
--- a/erts/emulator/sys/common/erl_check_io.c
+++ b/erts/emulator/sys/common/erl_check_io.c
@@ -44,7 +44,7 @@
 #include "erl_time.h"
 
 #if 0
-#define DEBUG_PRINT(FMT, ...) erts_printf(FMT "\r\n", ##__VA_ARGS__)
+#define DEBUG_PRINT(FMT, ...) do { erts_printf(FMT "\r\n", ##__VA_ARGS__); fflush(stdout); } while(0)
 #define DEBUG_PRINT_FD(FMT, STATE, ...)                                 \
     DEBUG_PRINT("%d: " FMT " (ev=%s, ac=%s, flg=%s)",                   \
                 (STATE) ? (STATE)->fd : (ErtsSysFdType)-1, ##__VA_ARGS__, \
@@ -534,6 +534,7 @@ erts_io_notify_port_task_executed(ErtsPortTaskType type,
             if (state->active_events & ERTS_POLL_EV_OUT)
                 oready(state->driver.select->outport, state);
             state->active_events = 0;
+            active_events = 0;
         }
     }
 
@@ -591,6 +592,96 @@ abort_tasks(ErtsDrvEventState *state, int mode)
     }
 }
 
+static void prepare_select_msg(struct erts_nif_select_event* e,
+                               enum ErlNifSelectFlags mode,
+                               Eterm recipient,
+                               ErtsResource* resource,
+                               Eterm msg,
+                               ErlNifEnv* msg_env,
+                               Eterm event_atom)
+{
+    ErtsMessage* mp;
+    Eterm* hp;
+    Uint hsz;
+
+    if (is_not_nil(e->pid)) {
+        ASSERT(e->mp);
+        erts_cleanup_messages(e->mp);
+    }
+
+    if (mode & ERL_NIF_SELECT_CUSTOM_MSG) {
+        if (msg_env) {
+            mp = erts_create_message_from_nif_env(msg_env);
+            ERL_MESSAGE_TERM(mp) = msg;
+        }
+        else {
+            hsz = size_object(msg);
+            mp = erts_alloc_message(hsz, &hp);
+            ERL_MESSAGE_TERM(mp) = copy_struct(msg, hsz, &hp, &mp->hfrag.off_heap);
+        }
+    }
+    else {
+        ErtsBinary* bin;
+        Eterm resource_term, ref_term, tuple;
+        Eterm* hp_start;
+
+         /* {select, Resource, Ref, EventAtom} */
+        hsz = 5 + ERTS_MAGIC_REF_THING_SIZE;
+        if (is_internal_ref(msg))
+            hsz += ERTS_REF_THING_SIZE;
+        else
+            ASSERT(is_immed(msg));
+
+        mp = erts_alloc_message(hsz, &hp);
+        hp_start = hp;
+
+        bin = ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(resource);
+        resource_term = erts_mk_magic_ref(&hp, &mp->hfrag.off_heap, &bin->binary);
+        if (is_internal_ref(msg)) {
+            Uint32* refn = internal_ref_numbers(msg);
+            write_ref_thing(hp, refn[0], refn[1], refn[2]);
+            ref_term = make_internal_ref(hp);
+            hp += ERTS_REF_THING_SIZE;
+        }
+        else {
+            ASSERT(is_immed(msg));
+            ref_term = msg;
+        }
+        tuple = TUPLE4(hp, am_select, resource_term, ref_term, event_atom);
+        hp += 5;
+        ERL_MESSAGE_TERM(mp) = tuple;
+        ASSERT(hp == hp_start + hsz); (void)hp_start;
+    }
+
+    ASSERT(is_not_nil(recipient));
+    e->pid = recipient;
+    e->mp = mp;
+}
+
+static ERTS_INLINE void send_select_msg(struct erts_nif_select_event* e)
+{
+    Process* rp = erts_proc_lookup(e->pid);
+
+    ASSERT(is_internal_pid(e->pid));
+    if (!rp) {
+        erts_cleanup_messages(e->mp);
+        return;
+    }
+
+    erts_queue_message(rp, 0, e->mp, ERL_MESSAGE_TERM(e->mp), am_system);
+}
+
+static void clear_select_event(struct erts_nif_select_event* e)
+{
+    if (is_not_nil(e->pid)) {
+        /* Discard unsent message */
+        ASSERT(e->mp);
+        erts_cleanup_messages(e->mp);
+        e->mp = NULL;
+        e->pid = NIL;
+    }
+}
+
 static void
 deselect(ErtsDrvEventState *state, int mode)
 {
@@ -621,8 +712,8 @@ deselect(ErtsDrvEventState *state, int mode)
         erts_io_control(state, ERTS_POLL_OP_DEL, 0);
 	switch (state->type) {
         case ERTS_EV_TYPE_NIF:
-            state->driver.nif->in.pid = NIL;
-            state->driver.nif->out.pid = NIL;
+            clear_select_event(&state->driver.nif->in);
+            clear_select_event(&state->driver.nif->out);
             enif_release_resource(state->driver.stop.resource->data);
             state->driver.stop.resource = NULL;
             break;
@@ -752,6 +843,8 @@ driver_select(ErlDrvPort ix, ErlDrvEvent e, int mode, int on)
             ret = 0;
             goto done_unknown;
         }
+        /* For some reason (don't know why), we do not clean all
+           events when doing ERL_DRV_USE_NO_CALLBACK. */
         else if ((mode&ERL_DRV_USE_NO_CALLBACK) == ERL_DRV_USE) {
             mode |= (ERL_DRV_READ | ERL_DRV_WRITE);
         }
@@ -943,12 +1036,21 @@ done_unknown:
 }
 
 int
-enif_select(ErlNifEnv* env,
-            ErlNifEvent e,
-            enum ErlNifSelectFlags mode,
-            void* obj,
-            const ErlNifPid* pid,
-            Eterm ref)
+enif_select(ErlNifEnv* env, ErlNifEvent e, enum ErlNifSelectFlags mode,
+            void* obj, const ErlNifPid* pid, Eterm msg)
+{
+    return enif_select_x(env, e, mode, obj, pid, msg, NULL);
+}
+
+
+int
+enif_select_x(ErlNifEnv* env,
+              ErlNifEvent e,
+              enum ErlNifSelectFlags mode,
+              void* obj,
+              const ErlNifPid* pid,
+              Eterm msg,
+              ErlNifEnv* msg_env)
 {
     int on;
     ErtsResource* resource = DATA_TO_RESOURCE(obj);
@@ -962,11 +1064,11 @@ enif_select(ErlNifEnv* env,
     ErtsDrvSelectDataState *free_select = NULL;
     ErtsNifSelectDataState *free_nif = NULL;
 
-    ASSERT(!resource->monitors);
+    ASSERT(!erts_dbg_is_resource_dying(resource));
 
 #ifdef ERTS_SYS_CONTINOUS_FD_NUMBERS
     if (!grow_drv_ev_state(fd)) {
-        if (fd > 0) nif_select_large_fd_error(fd, mode, resource, ref);
+        if (fd > 0) nif_select_large_fd_error(fd, mode, resource, msg);
         return INT_MIN | ERL_NIF_SELECT_INVALID_EVENT;
     }
 #endif
@@ -993,7 +1095,7 @@ enif_select(ErlNifEnv* env,
         ctl_op = ERTS_POLL_OP_DEL;
     }
     else {
-        on = 1;
+        on = !(mode & ERL_NIF_SELECT_CANCEL);
         ASSERT(mode);
         if (mode & ERL_DRV_READ) {
             ctl_events |= ERTS_POLL_EV_IN;
@@ -1012,21 +1114,21 @@ enif_select(ErlNifEnv* env,
          * Changing process and/or ref is ok (I think?).
          */
         if (state->driver.stop.resource != resource)
-            nif_select_steal(state, ERL_DRV_READ | ERL_DRV_WRITE, resource, ref);
+            nif_select_steal(state, ERL_DRV_READ | ERL_DRV_WRITE, resource, msg);
         break;
     case ERTS_EV_TYPE_DRV_SEL:
-        nif_select_steal(state, mode, resource, ref);
+        nif_select_steal(state, mode, resource, msg);
         break;
     case ERTS_EV_TYPE_STOP_USE: {
         erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
-        print_nif_select_op(dsbufp, fd, mode, resource, ref);
+        print_nif_select_op(dsbufp, fd, mode, resource, msg);
         steal_pending_stop_use(dsbufp, ERTS_INVALID_ERL_DRV_PORT, state, mode, on);
         ASSERT(state->type == ERTS_EV_TYPE_NONE);
         break;
     }
     case ERTS_EV_TYPE_STOP_NIF: {
         erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
-        print_nif_select_op(dsbufp, fd, mode, resource, ref);
+        print_nif_select_op(dsbufp, fd, mode, resource, msg);
         steal_pending_stop_nif(dsbufp, resource, state, mode, on);
         if (state->type == ERTS_EV_TYPE_STOP_NIF) {
             ret = ERL_NIF_SELECT_STOP_SCHEDULED;  /* ?? */
@@ -1082,7 +1184,7 @@ enif_select(ErlNifEnv* env,
 
     if (on) {
         const Eterm recipient = pid ? pid->pid : env->proc->common.id;
-        Uint32* refn;
+        ASSERT(is_internal_pid(recipient));
         if (!state->driver.nif)
             state->driver.nif = alloc_nif_select_data();
         if (state->type == ERTS_EV_TYPE_NONE) {
@@ -1093,64 +1195,62 @@ enif_select(ErlNifEnv* env,
         ASSERT(state->type == ERTS_EV_TYPE_NIF);
         ASSERT(state->driver.stop.resource == resource);
         if (mode & ERL_DRV_READ) {
-            state->driver.nif->in.pid = recipient;
-            if (is_immed(ref)) {
-                state->driver.nif->in.immed = ref;
-            } else {
-                ASSERT(is_internal_ref(ref));
-                refn = internal_ref_numbers(ref);
-                state->driver.nif->in.immed = THE_NON_VALUE;
-                sys_memcpy(state->driver.nif->in.refn, refn,
-                           sizeof(state->driver.nif->in.refn));
-            }
+            prepare_select_msg(&state->driver.nif->in, mode, recipient,
+                               resource, msg, msg_env, am_ready_input);
+            msg_env = NULL;
         }
         if (mode & ERL_DRV_WRITE) {
-            state->driver.nif->out.pid = recipient;
-            if (is_immed(ref)) {
-                state->driver.nif->out.immed = ref;
-            } else {
-                ASSERT(is_internal_ref(ref));
-                refn = internal_ref_numbers(ref);
-                state->driver.nif->out.immed = THE_NON_VALUE;
-                sys_memcpy(state->driver.nif->out.refn, refn,
-                           sizeof(state->driver.nif->out.refn));
-            }
+            prepare_select_msg(&state->driver.nif->out, mode, recipient,
+                               resource, msg, msg_env, am_ready_output);
         }
         ret = 0;
     }
     else { /* off */
+        ret = 0;
         if (state->type == ERTS_EV_TYPE_NIF) {
-            state->driver.nif->in.pid = NIL;
-            state->driver.nif->out.pid = NIL;
-        }
-        ASSERT(state->events==0);
-        if (!wake_poller) {
-            /*
-             * Safe to close fd now as it is not in pollset
-             * or there was no need to eject fd (kernel poll)
-             */
-            if (state->type == ERTS_EV_TYPE_NIF) {
-                ASSERT(state->driver.stop.resource == resource);
-                call_stop = CALL_STOP_AND_RELEASE;
-                state->driver.stop.resource = NULL;
+            if (mode & ERL_NIF_SELECT_READ
+                && is_not_nil(state->driver.nif->in.pid)) {
+                clear_select_event(&state->driver.nif->in);
+                ret |= ERL_NIF_SELECT_READ_CANCELLED;
             }
-            else {
-                ASSERT(!state->driver.stop.resource);
-                call_stop = CALL_STOP;
+            if (mode & ERL_NIF_SELECT_WRITE
+                && is_not_nil(state->driver.nif->out.pid)) {
+                clear_select_event(&state->driver.nif->out);
+                ret |= ERL_NIF_SELECT_WRITE_CANCELLED;
             }
-            state->type = ERTS_EV_TYPE_NONE;
-            ret = ERL_NIF_SELECT_STOP_CALLED;
         }
-        else {
-            /* Not safe to close fd, postpone stop_select callback. */
-            if (state->type == ERTS_EV_TYPE_NONE) {
-                ASSERT(!state->driver.stop.resource);
-                state->driver.stop.resource = resource;
-                enif_keep_resource(resource);
+        if (mode & ERL_NIF_SELECT_STOP) {
+            ASSERT(state->events==0);
+            if (!wake_poller) {
+                /*
+                 * Safe to close fd now as it is not in pollset
+                 * or there was no need to eject fd (kernel poll)
+                 */
+                if (state->type == ERTS_EV_TYPE_NIF) {
+                    ASSERT(state->driver.stop.resource == resource);
+                    call_stop = CALL_STOP_AND_RELEASE;
+                    state->driver.stop.resource = NULL;
+                }
+                else {
+                    ASSERT(!state->driver.stop.resource);
+                    call_stop = CALL_STOP;
+                }
+                state->type = ERTS_EV_TYPE_NONE;
+                ret |= ERL_NIF_SELECT_STOP_CALLED;
+            }
+            else {
+                /* Not safe to close fd, postpone stop_select callback. */
+                if (state->type == ERTS_EV_TYPE_NONE) {
+                    ASSERT(!state->driver.stop.resource);
+                    state->driver.stop.resource = resource;
+                    enif_keep_resource(resource);
+                }
+                state->type = ERTS_EV_TYPE_STOP_NIF;
+                ret |= ERL_NIF_SELECT_STOP_SCHEDULED;
             }
-            state->type = ERTS_EV_TYPE_STOP_NIF;
-            ret = ERL_NIF_SELECT_STOP_SCHEDULED;
         }
+        else
+            ASSERT(mode & ERL_NIF_SELECT_CANCEL);
     }
 
 done:
@@ -1328,7 +1428,8 @@ print_nif_select_op(erts_dsprintf_buf_t *dsbufp,
 		  (int) fd,
 		  mode & ERL_NIF_SELECT_READ ? " READ" : "",
 		  mode & ERL_NIF_SELECT_WRITE ? " WRITE" : "",
-		  mode & ERL_NIF_SELECT_STOP ? " STOP" : "",
+		  (mode & ERL_NIF_SELECT_STOP ? " STOP"
+                   : (mode & ERL_NIF_SELECT_CANCEL ? " CANCEL" : "")),
 		  resource->type->module,
                   resource->type->name,
                   ref);
@@ -1531,53 +1632,6 @@ oready(Eterm id, ErtsDrvEventState *state)
     }
 }
 
-static ERTS_INLINE void
-send_event_tuple(struct erts_nif_select_event* e, ErtsResource* resource,
-                 Eterm event_atom)
-{
-    Process* rp = erts_proc_lookup(e->pid);
-    ErtsProcLocks rp_locks = 0;
-    ErtsMessage* mp;
-    ErlOffHeap* ohp;
-    ErtsBinary* bin;
-    Eterm* hp;
-    Uint hsz;
-    Eterm resource_term, ref_term, tuple;
-
-    if (!rp) {
-        return;
-    }
-
-    bin = ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(resource);
-
-     /* {select, Resource, Ref, EventAtom} */
-    if (is_value(e->immed)) {
-        hsz = 5 + ERTS_MAGIC_REF_THING_SIZE;
-    }
-    else {
-        hsz = 5 + ERTS_MAGIC_REF_THING_SIZE + ERTS_REF_THING_SIZE;
-    }
-
-    mp = erts_alloc_message_heap(rp, &rp_locks, hsz, &hp, &ohp);
-
-    resource_term = erts_mk_magic_ref(&hp, ohp, &bin->binary);
-    if (is_value(e->immed)) {
-        ASSERT(is_immed(e->immed));
-        ref_term = e->immed;
-    }
-    else {
-        write_ref_thing(hp, e->refn[0], e->refn[1], e->refn[2]);
-        ref_term = make_internal_ref(hp);
-        hp += ERTS_REF_THING_SIZE;
-    }
-    tuple = TUPLE4(hp, am_select, resource_term, ref_term, event_atom);
-
-    erts_queue_message(rp, rp_locks, mp, tuple, am_system);
-
-    if (rp_locks)
-        erts_proc_unlock(rp, rp_locks);
-}
-
 static void bad_fd_in_pollset(ErtsDrvEventState *, Eterm inport, Eterm outport);
 
 void
@@ -1751,7 +1805,6 @@ erts_check_io(ErtsPollThread *psi, ErtsMonotonicTime timeout_time)
         case ERTS_EV_TYPE_NIF: { /* Requested via enif_select()... */
             struct erts_nif_select_event in = {NIL};
             struct erts_nif_select_event out = {NIL};
-            ErtsResource* resource = NULL;
 
             if (revents & (ERTS_POLL_EV_IN|ERTS_POLL_EV_OUT)) {
                 if (revents & ERTS_POLL_EV_OUT) {
@@ -1759,6 +1812,7 @@ erts_check_io(ErtsPollThread *psi, ErtsMonotonicTime timeout_time)
                         out = state->driver.nif->out;
                         resource = state->driver.stop.resource;
                         state->driver.nif->out.pid = NIL;
+                        state->driver.nif->out.mp = NULL;
                     }
                 }
                 if (revents & ERTS_POLL_EV_IN) {
@@ -1766,6 +1820,7 @@ erts_check_io(ErtsPollThread *psi, ErtsMonotonicTime timeout_time)
                         in = state->driver.nif->in;
                         resource = state->driver.stop.resource;
                         state->driver.nif->in.pid = NIL;
+                        state->driver.nif->in.mp = NULL;
                     }
                 }
                 state->events &= ~revents;
@@ -1778,10 +1833,10 @@ erts_check_io(ErtsPollThread *psi, ErtsMonotonicTime timeout_time)
             erts_mtx_unlock(fd_mtx(fd));
 
             if (is_not_nil(in.pid)) {
-                send_event_tuple(&in, resource, am_ready_input);
+                send_select_msg(&in);
             }
             if (is_not_nil(out.pid)) {
-                send_event_tuple(&out, resource, am_ready_output);
+                send_select_msg(&out);
             }
             continue;
         }
@@ -2262,14 +2317,14 @@ erts_check_io_info(void *proc)
 
 #if ERTS_POLL_USE_FALLBACK
     erts_poll_info_flbk(get_fallback_pollset(), &piv[0]);
-    piv[0].poll_threads = 1;
+    piv[0].poll_threads = 0;
     piv[0].active_fds = 0;
     piv++;
 #endif
 
 #if ERTS_POLL_USE_SCHEDULER_POLLING
     erts_poll_info(get_scheduler_pollset(0), &piv[0]);
-    piv[0].poll_threads = 1;
+    piv[0].poll_threads = 0;
     piv[0].active_fds = 0;
     piv++;
 #endif
@@ -2439,6 +2494,10 @@ drvmode2str(int mode) {
     case ERL_DRV_WRITE|ERL_DRV_USE: return "WRITE|USE";
     case ERL_DRV_READ|ERL_DRV_WRITE|ERL_DRV_USE: return "READ|WRITE|USE";
     case ERL_DRV_USE: return "USE";
+    case ERL_DRV_READ|ERL_DRV_USE_NO_CALLBACK: return "READ|USE_NO_CB";
+    case ERL_DRV_WRITE|ERL_DRV_USE_NO_CALLBACK: return "WRITE|USE_NO_CB";
+    case ERL_DRV_READ|ERL_DRV_WRITE|ERL_DRV_USE_NO_CALLBACK: return "READ|WRITE|USE_NO_CB";
+    case ERL_DRV_USE_NO_CALLBACK: return "USE_NO_CB";
     case ERL_DRV_READ: return "READ";
     case ERL_DRV_WRITE: return "WRITE";
     case ERL_DRV_READ|ERL_DRV_WRITE: return "READ|WRITE";
@@ -2448,10 +2507,16 @@ drvmode2str(int mode) {
 
 static ERTS_INLINE char *
 nifmode2str(enum ErlNifSelectFlags mode) {
+    if (mode & ERL_NIF_SELECT_STOP)
+        return "STOP";
     switch (mode) {
     case ERL_NIF_SELECT_READ: return "READ";
     case ERL_NIF_SELECT_WRITE: return "WRITE";
-    case ERL_NIF_SELECT_STOP: return "STOP";
+    case ERL_NIF_SELECT_READ|ERL_NIF_SELECT_WRITE: return "READ|WRITE";
+    case ERL_NIF_SELECT_CANCEL|ERL_NIF_SELECT_READ: return "CANCEL|READ";
+    case ERL_NIF_SELECT_CANCEL|ERL_NIF_SELECT_WRITE: return "CANCEL|WRITE";
+    case ERL_NIF_SELECT_CANCEL|ERL_NIF_SELECT_READ|ERL_NIF_SELECT_WRITE:
+        return "CANCEL|READ|WRITE";
     default: return "UNKNOWN";
     }
 }
diff --git a/erts/emulator/sys/common/erl_check_io.h b/erts/emulator/sys/common/erl_check_io.h
index 31182be5ec..0f3fc4f7a2 100644
--- a/erts/emulator/sys/common/erl_check_io.h
+++ b/erts/emulator/sys/common/erl_check_io.h
@@ -138,8 +138,7 @@ typedef struct {
 
 struct erts_nif_select_event {
     Eterm pid;
-    Eterm immed;
-    Uint32 refn[ERTS_REF_NUMBERS];
+    ErtsMessage *mp;
 };
 
 typedef struct {
diff --git a/erts/emulator/sys/common/erl_mmap.h b/erts/emulator/sys/common/erl_mmap.h
index 539daea419..3085bf7e19 100644
--- a/erts/emulator/sys/common/erl_mmap.h
+++ b/erts/emulator/sys/common/erl_mmap.h
@@ -176,4 +176,61 @@ void hard_dbg_remove_mseg(void* seg, UWord sz);
 
 #endif /* HAVE_ERTS_MMAP */
 
+/* Marks the given memory region as unused without freeing it, letting the OS
+ * reclaim its physical memory with the promise that we'll get it back (without
+ * its contents) the next time it's accessed. */
+ERTS_GLB_INLINE void erts_mem_discard(void *p, UWord size);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+#ifdef VALGRIND
+    #include <valgrind/memcheck.h>
+
+    ERTS_GLB_INLINE void erts_mem_discard(void *ptr, UWord size) {
+        VALGRIND_MAKE_MEM_UNDEFINED(ptr, size);
+    }
+#elif defined(DEBUG)
+    /* Try to provoke crashes by filling the discard region with garbage. It's
+     * extremely hard to find bugs where we've discarded too much, as the
+     * region often retains its old contents if it's accessed before the OS
+     * reclaims it. */
+    ERTS_GLB_INLINE void erts_mem_discard(void *ptr, UWord size) {
+        static const char pattern[] = "DISCARDED";
+        char *data;
+        int i;
+
+        for(i = 0, data = ptr; i < size; i++) {
+            data[i] = pattern[i % sizeof(pattern)];
+        }
+    }
+#elif defined(HAVE_SYS_MMAN_H) && !(defined(__sun) || defined(__sun__))
+    #include <sys/mman.h>
+
+    ERTS_GLB_INLINE void erts_mem_discard(void *ptr, UWord size) {
+    #ifdef MADV_FREE
+        /* This is preferred as it doesn't necessarily free the pages right
+         * away, which is a bit faster than MADV_DONTNEED. */
+        madvise(ptr, size, MADV_FREE);
+    #else
+        madvise(ptr, size, MADV_DONTNEED);
+    #endif
+    }
+#elif defined(_WIN32)
+    #include <winbase.h>
+
+    /* MEM_RESET is defined on all supported versions of Windows, and has the
+     * same semantics as MADV_FREE. */
+    ERTS_GLB_INLINE void erts_mem_discard(void *ptr, UWord size) {
+        VirtualAlloc(ptr, size, MEM_RESET, PAGE_READWRITE);
+    }
+#else
+    /* Dummy implementation. */
+    ERTS_GLB_INLINE void erts_mem_discard(void *ptr, UWord size) {
+        (void)ptr;
+        (void)size;
+    }
+#endif
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
 #endif /* ERL_MMAP_H__ */
diff --git a/erts/emulator/sys/common/erl_osenv.c b/erts/emulator/sys/common/erl_osenv.c
index 6a16377736..f055c5f854 100644
--- a/erts/emulator/sys/common/erl_osenv.c
+++ b/erts/emulator/sys/common/erl_osenv.c
@@ -167,9 +167,10 @@ void erts_osenv_init(erts_osenv_t *env) {
     env->tree = NULL;
 }
 
-static void destroy_foreach(env_rbtnode_t *node, void *_state) {
+static int destroy_foreach(env_rbtnode_t *node, void *_state, Sint reds) {
     erts_free(ERTS_ALC_T_ENVIRONMENT, node);
     (void)_state;
+    return 1;
 }
 
 void erts_osenv_clear(erts_osenv_t *env) {
@@ -182,7 +183,7 @@ struct __env_merge {
     erts_osenv_t *env;
 };
 
-static void merge_foreach(env_rbtnode_t *node, void *_state) {
+static int merge_foreach(env_rbtnode_t *node, void *_state, Sint reds) {
     struct __env_merge *state = (struct __env_merge*)(_state);
     env_rbtnode_t *existing_node;
 
@@ -191,6 +192,7 @@ static void merge_foreach(env_rbtnode_t *node, void *_state) {
     if(existing_node == NULL || state->overwrite_existing) {
         erts_osenv_put_native(state->env, &node->key, &node->value);
     }
+    return 1;
 }
 
 void erts_osenv_merge(erts_osenv_t *env, const erts_osenv_t *with, int overwrite) {
@@ -208,7 +210,7 @@ struct __env_foreach_term {
     void *user_state;
 };
 
-static void foreach_term_wrapper(env_rbtnode_t *node, void *_state) {
+static int foreach_term_wrapper(env_rbtnode_t *node, void *_state, Sint reds) {
     struct __env_foreach_term *state = (struct __env_foreach_term*)_state;
     Eterm key, value;
 
@@ -218,6 +220,7 @@ static void foreach_term_wrapper(env_rbtnode_t *node, void *_state) {
         node->value.length, (byte*)node->value.data);
 
     state->user_callback(state->process, state->user_state, key, value);
+    return 1;
 }
 
 void erts_osenv_foreach_term(const erts_osenv_t *env, struct process *process,
@@ -314,10 +317,11 @@ struct __env_foreach_native {
     void *user_state;
 };
 
-static void foreach_native_wrapper(env_rbtnode_t *node, void *_state) {
+static int foreach_native_wrapper(env_rbtnode_t *node, void *_state, Sint reds) {
     struct __env_foreach_native *state = (struct __env_foreach_native*)_state;
 
     state->user_callback(state->user_state, &node->key, &node->value);
+    return 1;
 }
 
 void erts_osenv_foreach_native(const erts_osenv_t *env, void *state,
diff --git a/erts/emulator/sys/common/erl_poll.c b/erts/emulator/sys/common/erl_poll.c
index 51d50933ff..1b125056f5 100644
--- a/erts/emulator/sys/common/erl_poll.c
+++ b/erts/emulator/sys/common/erl_poll.c
@@ -872,8 +872,8 @@ update_pollset(ErtsPollSet *ps, int fd, ErtsPollOp op, ErtsPollEvents events)
         }
     }
 
-#if defined(EV_DISPATCH) && !defined(__OpenBSD__)
-    /* If we have EV_DISPATCH we use it, unless we are on OpenBSD as the
+#if defined(EV_DISPATCH) && !(defined(__OpenBSD__) || defined(__NetBSD__))
+    /* If we have EV_DISPATCH we use it, unless we are on OpenBSD/NetBSD as the
        behavior of EV_EOF seems to be edge triggered there and we need it
        to be level triggered.
 
@@ -924,7 +924,7 @@ update_pollset(ErtsPollSet *ps, int fd, ErtsPollOp op, ErtsPollEvents events)
         ERTS_EV_SET(&evts[len++], fd, EVFILT_WRITE, flags, (void *) ERTS_POLL_EV_OUT);
     }
 #else
-    uint32_t flags = EV_ADD;
+    uint32_t flags = EV_ADD|EV_ENABLE;
 
     if (ps->oneshot) flags |= EV_ONESHOT;
 
@@ -932,9 +932,27 @@ update_pollset(ErtsPollSet *ps, int fd, ErtsPollOp op, ErtsPollEvents events)
         erts_atomic_dec_nob(&ps->no_of_user_fds);
         /* We don't do anything when a delete is issued. The fds will be removed
            when they are triggered, or when they are closed. */
-        events = 0;
+        if (ps->oneshot)
+            events = 0;
+        else {
+            flags = EV_DELETE;
+            events = ERTS_POLL_EV_IN;
+        }
     } else if (op == ERTS_POLL_OP_ADD) {
         erts_atomic_inc_nob(&ps->no_of_user_fds);
+        /* Only allow EV_IN in non-oneshot poll-sets */
+        ASSERT(ps->oneshot || events == ERTS_POLL_EV_IN);
+    } else if (!ps->oneshot) {
+        ASSERT(op == ERTS_POLL_OP_MOD);
+        /* If we are not oneshot and do a mod we should disable the FD.
+           We assume that it is only the read side that is active as
+           currently only read is selected upon in the non-oneshot
+           poll-sets. */
+        if (!events)
+            flags = EV_DISABLE;
+        else
+            flags = EV_ENABLE;
+        events = ERTS_POLL_EV_IN;
     }
 
     if (events & ERTS_POLL_EV_IN) {
@@ -961,16 +979,15 @@ update_pollset(ErtsPollSet *ps, int fd, ErtsPollOp op, ErtsPollEvents events)
         for (i = 0; i < len; i++) {
             const char *flags = "UNKNOWN";
             if (evts[i].flags == (EV_DELETE)) flags = "EV_DELETE";
-            if (evts[i].flags == (EV_ADD|EV_ONESHOT)) flags = "EV_ADD|EV_ONESHOT";
             if (evts[i].flags == (EV_ADD)) flags = "EV_ADD";
+            if (evts[i].flags == (EV_ADD|EV_ONESHOT)) flags = "EV_ADD|EV_ONESHOT";
+            if (evts[i].flags == (EV_ENABLE)) flags = "EV_ENABLE";
+            if (evts[i].flags == (EV_DISABLE)) flags = "EV_DISABLE";
+            if (evts[i].flags == (EV_ADD|EV_DISABLE)) flags = "EV_ADD|EV_DISABLE";
 #ifdef EV_DISPATCH
             if (evts[i].flags == (EV_ADD|EV_DISPATCH)) flags = "EV_ADD|EV_DISPATCH";
-            if (evts[i].flags == (EV_ADD|EV_DISABLE)) flags = "EV_ADD|EV_DISABLE";
             if (evts[i].flags == (EV_ENABLE|EV_DISPATCH)) flags = "EV_ENABLE|EV_DISPATCH";
-            if (evts[i].flags == (EV_ENABLE)) flags = "EV_ENABLE";
-            if (evts[i].flags == (EV_DISABLE)) flags = "EV_DISABLE";
             if (evts[i].flags == (EV_DISABLE|EV_DISPATCH)) flags = "EV_DISABLE|EV_DISABLE";
-            if (evts[i].flags == (EV_DISABLE)) flags = "EV_DISABLE";
 #endif
 
             keventbp += sprintf(keventbp, "%s{%lu, %s, %s}",i > 0 ? ", " : "",
@@ -2326,6 +2343,7 @@ uint32_t epoll_events(int kp_fd, int fd)
 {
     /* For epoll we read the information about what is selected upon from the proc fs.*/
     char fname[30];
+    char s[256];
     FILE *f;
     unsigned int pos, flags, mnt_id;
     int line = 0;
@@ -2343,16 +2361,17 @@ uint32_t epoll_events(int kp_fd, int fd)
     }
     if (fscanf(f,"\nmnt_id:\t%x\n", &mnt_id));
     line += 3;
-    while (!feof(f)) {
+    while (fgets(s, sizeof(s) / sizeof(*s), f)) {
         /* tfd:       10 events: 40000019 data:       180000000a */
         int ev_fd;
         uint32_t events;
         uint64_t data;
-        if (fscanf(f,"tfd:%d events:%x data:%llx\n", &ev_fd, &events,
+        if (sscanf(s,"tfd:%d events:%x data:%llx", &ev_fd, &events,
                    (unsigned long long*)&data) != 3) {
             fprintf(stderr,"failed to parse file %s on line %d, errno = %d\n", fname,
                     line,
                     errno);
+            fclose(f);
             return 0;
         }
         if (fd == ev_fd) {
@@ -2392,6 +2411,7 @@ ERTS_POLL_EXPORT(erts_poll_get_selected_events)(ErtsPollSet *ps,
 
     /* For epoll we read the information about what is selected upon from the proc fs.*/
     char fname[30];
+    char s[256];
     FILE *f;
     unsigned int pos, flags, mnt_id;
     int line = 0;
@@ -2406,20 +2426,22 @@ ERTS_POLL_EXPORT(erts_poll_get_selected_events)(ErtsPollSet *ps,
     if (fscanf(f,"pos:\t%x\nflags:\t%x", &pos, &flags) != 2) {
         fprintf(stderr,"failed to parse file %s, errno = %d\n", fname, errno);
         ASSERT(0);
+        fclose(f);
         return;
     }
     if (fscanf(f,"\nmnt_id:\t%x\n", &mnt_id));
     line += 3;
-    while (!feof(f)) {
+    while (fgets(s, sizeof(s) / sizeof(*s), f)) {
         /* tfd:       10 events: 40000019 data:       180000000a */
         int fd;
         uint32_t events;
         uint64_t data;
-        if (fscanf(f,"tfd:%d events:%x data:%llx\n", &fd, &events,
+        if (sscanf(s,"tfd:%d events:%x data:%llx", &fd, &events,
                    (unsigned long long*)&data) != 3) {
             fprintf(stderr,"failed to parse file %s on line %d, errno = %d\n",
                     fname, line, errno);
             ASSERT(0);
+            fclose(f);
             return;
         }
         if (fd == ps->wake_fds[0] || fd == ps->wake_fds[1])
@@ -2435,6 +2457,7 @@ ERTS_POLL_EXPORT(erts_poll_get_selected_events)(ErtsPollSet *ps,
         ev[fd] = (ERTS_POLL_EV_IN|ERTS_POLL_EV_OUT) & ERTS_POLL_EV_N2E(events);
         line++;
     }
+    fclose(f);
 #else
     for (fd = 0; fd < len; fd++)
         ev[fd] = ERTS_POLL_EV_NONE;
diff --git a/erts/emulator/sys/unix/sys_drivers.c b/erts/emulator/sys/unix/sys_drivers.c
index 816bdea9c5..92020c6f35 100644
--- a/erts/emulator/sys/unix/sys_drivers.c
+++ b/erts/emulator/sys/unix/sys_drivers.c
@@ -732,7 +732,8 @@ static ErlDrvData spawn_start(ErlDrvPort port_num, char* name,
         proto->u.start.fds[1] = ifd[1];
         proto->u.start.fds[2] = stderrfd;
         proto->u.start.port_id = opts->exit_status ? erts_drvport2id(port_num) : THE_NON_VALUE;
-        if (erl_drv_port_control(forker_port, 'S', (char*)proto, sizeof(*proto))) {
+        if (erl_drv_port_control(forker_port, ERTS_FORKER_DRV_CONTROL_MAGIC_NUMBER,
+                                 (char*)proto, sizeof(*proto))) {
             /* The forker port has been killed, we close both fd's which will
                make open_port throw an epipe error */
             close(ofd[0]);
@@ -759,6 +760,9 @@ static ErlDrvSSizeT spawn_control(ErlDrvData e, unsigned int cmd, char *buf,
     ErtsSysDriverData *dd = (ErtsSysDriverData*)e;
     ErtsSysForkerProto *proto = (ErtsSysForkerProto *)buf;
 
+    if (cmd != ERTS_SPAWN_DRV_CONTROL_MAGIC_NUMBER)
+        return -1;
+
     ASSERT(len == sizeof(*proto));
     ASSERT(proto->action == ErtsSysForkerProtoAction_SigChld);
 
@@ -781,15 +785,15 @@ static ErlDrvSSizeT spawn_control(ErlDrvData e, unsigned int cmd, char *buf,
 
 static int fd_get_window_size(int fd, Uint32 *width, Uint32 *height)
 {
-#ifdef TIOCGWINSZ 
+#ifdef TIOCGWINSZ
     struct winsize ws;
     if (ioctl(fd,TIOCGWINSZ,&ws) == 0) {
 	*width = (Uint32) ws.ws_col;
 	*height = (Uint32) ws.ws_row;
-	return 0;
+	return 1;
     }
 #endif
-    return -1;
+    return 0;
 }
 
 static ErlDrvSSizeT fd_control(ErlDrvData drv_data,
@@ -797,20 +801,34 @@ static ErlDrvSSizeT fd_control(ErlDrvData drv_data,
 			       char *buf, ErlDrvSizeT len,
 			       char **rbuf, ErlDrvSizeT rlen)
 {
-    int fd = (int)(long)drv_data;
     char resbuff[2*sizeof(Uint32)];
+    ErtsSysDriverData* dd = (ErtsSysDriverData*)drv_data;
+    command -= ERTS_TTYSL_DRV_CONTROL_MAGIC_NUMBER;
     switch (command) {
     case FD_CTRL_OP_GET_WINSIZE:
 	{
 	    Uint32 w,h;
-	    if (fd_get_window_size(fd,&w,&h)) 
-		return 0;
+            int success = 0;
+            if (dd->ofd != NULL) {
+                /* Try with output file descriptor */
+                int out_fd = dd->ofd->fd;
+                success = fd_get_window_size(out_fd,&w,&h);
+            }
+            if (!success && dd->ifd != NULL) {
+                /* Try with input file descriptor */
+                int in_fd = dd->ifd->fd;
+                success = fd_get_window_size(in_fd,&w,&h);
+            }
+            if (!success) {
+                return -1;
+            }
+            /* Succeeded */
 	    memcpy(resbuff,&w,sizeof(Uint32));
 	    memcpy(resbuff+sizeof(Uint32),&h,sizeof(Uint32));
 	}
 	break;
     default:
-	return 0;
+	return -1;
     }
     if (rlen < 2*sizeof(Uint32)) {
 	*rbuf = driver_alloc(2*sizeof(Uint32));
@@ -998,12 +1016,10 @@ static void clear_fd_data(ErtsSysFdData *fdd)
     fdd->psz = 0;
 }
 
-static void nbio_stop_fd(ErlDrvPort prt, ErtsSysFdData *fdd)
+static void nbio_stop_fd(ErlDrvPort prt, ErtsSysFdData *fdd, int use)
 {
-    driver_select(prt, abs(fdd->fd), ERL_DRV_USE_NO_CALLBACK|DO_READ|DO_WRITE, 0);
     clear_fd_data(fdd);
     SET_BLOCKING(abs(fdd->fd));
-
 }
 
 static void fd_stop(ErlDrvData ev)  /* Does not close the fds */
@@ -1020,11 +1036,13 @@ static void fd_stop(ErlDrvData ev)  /* Does not close the fds */
 
     if (dd->ifd) {
         sz += sizeof(ErtsSysFdData);
-        nbio_stop_fd(prt, dd->ifd);
+        driver_select(prt, abs(dd->ifd->fd), ERL_DRV_USE_NO_CALLBACK|DO_READ|DO_WRITE, 0);
+        nbio_stop_fd(prt, dd->ifd, 1);
     }
     if (dd->ofd && dd->ofd != dd->ifd) {
         sz += sizeof(ErtsSysFdData);
-        nbio_stop_fd(prt, dd->ofd);
+        driver_select(prt, abs(dd->ofd->fd), ERL_DRV_USE_NO_CALLBACK|DO_WRITE, 0);
+        nbio_stop_fd(prt, dd->ofd, 1);
     }
 
      erts_free(ERTS_ALC_T_DRV_TAB, dd);
@@ -1070,12 +1088,12 @@ static void stop(ErlDrvData ev)
     ErlDrvPort prt = dd->port_num;
 
     if (dd->ifd) {
-        nbio_stop_fd(prt, dd->ifd);
+        nbio_stop_fd(prt, dd->ifd, 0);
         driver_select(prt, abs(dd->ifd->fd), ERL_DRV_USE, 0);  /* close(ifd); */
     }
 
     if (dd->ofd && dd->ofd != dd->ifd) {
-	nbio_stop_fd(prt, dd->ofd);
+	nbio_stop_fd(prt, dd->ofd, 0);
 	driver_select(prt, abs(dd->ofd->fd), ERL_DRV_USE, 0);  /* close(ofd); */
     }
 
@@ -1693,7 +1711,8 @@ static void forker_sigchld(Eterm port_id, int error)
        already used by the spawn_driver, we use control instead.
        Note that when using erl_drv_port_control it is an asynchronous
        control. */
-    erl_drv_port_control(port_id, 'S', (char*)proto, sizeof(*proto));
+    erl_drv_port_control(port_id, ERTS_SPAWN_DRV_CONTROL_MAGIC_NUMBER,
+                         (char*)proto, sizeof(*proto));
 }
 
 static void forker_ready_input(ErlDrvData e, ErlDrvEvent fd)
@@ -1778,6 +1797,9 @@ static ErlDrvSSizeT forker_control(ErlDrvData e, unsigned int cmd, char *buf,
     ErlDrvPort port_num = (ErlDrvPort)e;
     int res;
 
+    if (cmd != ERTS_FORKER_DRV_CONTROL_MAGIC_NUMBER)
+        return -1;
+
     if (first_call) {
         /*
          * Do driver_select here when schedulers and their pollsets have started.
diff --git a/erts/emulator/sys/win32/sys.c b/erts/emulator/sys/win32/sys.c
index a1c630d68a..b95aadc9b2 100644
--- a/erts/emulator/sys/win32/sys.c
+++ b/erts/emulator/sys/win32/sys.c
@@ -186,7 +186,9 @@ void sys_primitive_init(HMODULE beam)
 UWord
 erts_sys_get_page_size(void)
 {
-    return (UWord) 4*1024; /* Guess 4 KB */
+    SYSTEM_INFO info;
+    GetSystemInfo(&info);
+    return (UWord)info.dwPageSize;
 }
 
 Uint
diff --git a/erts/emulator/test/Makefile b/erts/emulator/test/Makefile
index 6a064ec8d4..019af2162f 100644
--- a/erts/emulator/test/Makefile
+++ b/erts/emulator/test/Makefile
@@ -28,6 +28,24 @@ EBIN = .
 # Target Specs
 # ----------------------------------------------------
 
+SOCKET_MODULES = \
+	socket_test_lib \
+	socket_test_logger \
+	socket_test_evaluator \
+	socket_test_ttest_lib \
+	socket_test_ttest_tcp_gen \
+	socket_test_ttest_tcp_socket \
+	socket_test_ttest_tcp_client \
+	socket_test_ttest_tcp_client_gen \
+	socket_test_ttest_tcp_client_socket \
+	socket_test_ttest_tcp_server \
+	socket_test_ttest_tcp_server_gen \
+	socket_test_ttest_tcp_server_socket \
+	socket_SUITE
+
+NET_MODULES = \
+	net_SUITE
+
 MODULES= \
 	a_SUITE \
 	after_SUITE \
@@ -84,6 +102,7 @@ MODULES= \
 	monitor_SUITE \
 	multi_load_SUITE \
 	nested_SUITE \
+	$(NET_MODULES) \
 	nif_SUITE \
 	node_container_SUITE \
 	nofrag_SUITE \
@@ -105,7 +124,9 @@ MODULES= \
 	send_term_SUITE \
 	sensitive_SUITE \
 	signal_SUITE \
+	small_SUITE \
 	smoke_test_SUITE \
+	$(SOCKET_MODULES) \
 	statistics_SUITE \
 	system_info_SUITE \
 	system_profile_SUITE \
@@ -130,6 +151,7 @@ MODULES= \
 	ignore_cores \
 	dgawd_handler \
 	random_iolist \
+	erts_test_utils \
 	crypto_reference
 
 NO_OPT= bs_bincomp \
@@ -152,8 +174,14 @@ NATIVE_MODULES= $(NATIVE:%=%_native_SUITE)
 NATIVE_ERL_FILES= $(NATIVE_MODULES:%=%.erl)
 
 ERL_FILES= $(MODULES:%=%.erl)
+HRL_FILES= \
+	socket_test_evaluator.hrl \
+	socket_test_ttest.hrl \
+	socket_test_ttest_client.hrl
 
 TARGET_FILES = $(MODULES:%=$(EBIN)/%.$(EMULATOR))
+NET_TARGETS = $(NET_MODULES:%=$(EBIN)/%.$(EMULATOR))
+SOCKET_TARGETS = $(SOCKET_MODULES:%=$(EBIN)/%.$(EMULATOR))
 
 EMAKEFILE=Emakefile
 
@@ -179,14 +207,10 @@ ERL_COMPILE_FLAGS +=
 # ----------------------------------------------------
 
 make_emakefile: $(NO_OPT_ERL_FILES) $(NATIVE_ERL_FILES)
-	# This special rule can be removed when communication with R7B nodes 
-	# is no longer supported.
-	$(ERL_TOP)/make/make_emakefile $(ERL_COMPILE_FLAGS) +compressed -o$(EBIN) \
-	'*_SUITE_make' > $(EMAKEFILE)
 	$(ERL_TOP)/make/make_emakefile $(ERL_COMPILE_FLAGS) +compressed -o$(EBIN) \
 	$(MODULES) >> $(EMAKEFILE)
-	$(ERL_TOP)/make/make_emakefile +no_copt +no_postopt $(ERL_COMPILE_FLAGS) \
-	-o$(EBIN) $(NO_OPT_MODULES) >> $(EMAKEFILE)
+	$(ERL_TOP)/make/make_emakefile +no_copt +no_postopt +no_ssa_opt +no_bsm_opt \
+        $(ERL_COMPILE_FLAGS) -o$(EBIN) $(NO_OPT_MODULES) >> $(EMAKEFILE)
 	$(ERL_TOP)/make/make_emakefile +native $(ERL_COMPILE_FLAGS) \
 	-o$(EBIN) $(NATIVE_MODULES) >> $(EMAKEFILE)
 
@@ -200,6 +224,10 @@ clean:
 
 docs:
 
+targets: $(TARGET_FILES)
+socket_targets: $(SOCKET_TARGETS)
+net_targets: $(NET_TARGETS)
+
 # ----------------------------------------------------
 # Special targets
 # ----------------------------------------------------
@@ -220,7 +248,7 @@ release_spec:
 release_tests_spec: make_emakefile
 	$(INSTALL_DIR) "$(RELSYSDIR)"
 	$(INSTALL_DATA) $(EMAKEFILE) $(TEST_SPEC_FILES) \
-		$(ERL_FILES) "$(RELSYSDIR)"
+		$(ERL_FILES) $(HRL_FILES) "$(RELSYSDIR)"
 	$(INSTALL_DATA) $(NO_OPT_ERL_FILES) "$(RELSYSDIR)"
 	$(INSTALL_DATA) $(NATIVE_ERL_FILES) "$(RELSYSDIR)"
 	chmod -R u+w "$(RELSYSDIR)"
diff --git a/erts/emulator/test/alloc_SUITE.erl b/erts/emulator/test/alloc_SUITE.erl
index 343afe85e6..4e0243c1cd 100644
--- a/erts/emulator/test/alloc_SUITE.erl
+++ b/erts/emulator/test/alloc_SUITE.erl
@@ -71,7 +71,8 @@ migration(Cfg) ->
     %% Disable driver_alloc to avoid recursive alloc_util calls
     %% through enif_mutex_create() in my_creating_mbc().
     drv_case(Cfg, concurrent, "+MZe true +MRe false"),
-    drv_case(Cfg, concurrent, "+MZe true +MRe false +MZas ageffcbf").
+    drv_case(Cfg, concurrent, "+MZe true +MRe false +MZas ageffcbf"),
+    drv_case(Cfg, concurrent, "+MZe true +MRe false +MZas chaosff").
 
 erts_mmap(Config) when is_list(Config) ->
     case {os:type(), mmsc_flags()} of
diff --git a/erts/emulator/test/atomics_SUITE.erl b/erts/emulator/test/atomics_SUITE.erl
index 8c42354770..a5407c42ee 100644
--- a/erts/emulator/test/atomics_SUITE.erl
+++ b/erts/emulator/test/atomics_SUITE.erl
@@ -126,6 +126,9 @@ unsigned_limits(Config) when is_list(Config) ->
     Min = atomics:add_get(Ref, 1, 1),
     Max = atomics:sub_get(Ref, 1, 1),
 
+    atomics:put(Ref, 1, Max),
+    io:format("Max=~p~n", [atomics:get(Ref, 1)]),
+
     {'EXIT',{badarg,_}} = (catch atomics:add(Ref, 1, Max+1)),
     IncrMin = -(1 bsl (Bits-1)),
     ok = atomics:put(Ref, 1, -IncrMin),
diff --git a/erts/emulator/test/bif_SUITE.erl b/erts/emulator/test/bif_SUITE.erl
index 9e7bcd5255..c5abd04e07 100644
--- a/erts/emulator/test/bif_SUITE.erl
+++ b/erts/emulator/test/bif_SUITE.erl
@@ -37,7 +37,9 @@
          group_leader_prio/1, group_leader_prio_dirty/1,
          is_process_alive/1,
          process_info_blast/1,
-         os_env_case_sensitivity/1]).
+         os_env_case_sensitivity/1,
+         test_length/1,
+         fixed_apply_badarg/1]).
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
@@ -52,7 +54,8 @@ all() ->
      erl_crash_dump_bytes, min_max, erlang_halt, is_builtin,
      error_stacktrace, error_stacktrace_during_call_trace,
      group_leader_prio, group_leader_prio_dirty,
-     is_process_alive, process_info_blast, os_env_case_sensitivity].
+     is_process_alive, process_info_blast, os_env_case_sensitivity,
+     test_length,fixed_apply_badarg].
 
 %% Uses erlang:display to test that erts_printf does not do deep recursion
 display(Config) when is_list(Config) ->
@@ -609,6 +612,16 @@ binary_to_existing_atom(Config) when is_list(Config) ->
 
     UnlikelyAtom = binary_to_atom(id(UnlikelyBin), latin1),
     UnlikelyAtom = binary_to_existing_atom(UnlikelyBin, latin1),
+
+    %% ERL-944; a binary that was too large would overflow the latin1-to-utf8
+    %% conversion buffer.
+    OverflowAtom = <<0:511/unit:8,
+                     196, 133, 196, 133, 196, 133, 196, 133, 196, 133,
+                     196, 133, 196, 133, 196, 133, 196, 133, 196, 133,
+                     196, 133, 196, 133, 196, 133, 196, 133, 196, 133,
+                     196, 133, 196, 133, 196, 133, 196, 133, 196, 133>>,
+    {'EXIT', _} = (catch binary_to_existing_atom(OverflowAtom, latin1)),
+
     ok.
 
 
@@ -1181,7 +1194,70 @@ consume_msgs() ->
     after 0 ->
               ok
     end.
-                              
+
+%% Test that length/1 returns the correct result after trapping, and
+%% also that the argument is correct in the stacktrace for a badarg
+%% exception.
+
+test_length(_Config) ->
+    {Start,Inc} = case test_server:timetrap_scale_factor() of
+                      1 -> {16*4000,3977};
+                      _ -> {100,1}
+            end,
+    Good = lists:reverse(lists:seq(1, Start)),
+    Bad = Good ++ [bad|cons],
+    test_length(Start, 10*Start, Inc, Good, Bad),
+
+    %% Test that calling length/1 from a match spec works.
+    MsList = lists:seq(1, 2*Start),
+    MsInput = [{tag,Good},{tag,MsList}],
+    Ms0 = [{{tag,'$1'},[{'>',{length,'$1'},Start}],['$1']}],
+    Ms = ets:match_spec_compile(Ms0),
+    [MsList] = ets:match_spec_run(MsInput, Ms),
+    ok.
+
+test_length(I, N, Inc, Good, Bad) when I < N ->
+    Length = id(length),
+    I = length(Good),
+    I = erlang:Length(Good),
+
+    %% Test length/1 in guards.
+    if
+        length(Good) =:= I ->
+            ok
+    end,
+    if
+        length(Bad) =:= I ->
+            error(should_fail);
+        true ->
+            ok
+    end,
+
+    {'EXIT',{badarg,[{erlang,length,[[I|_]],_}|_]}} = (catch length(Bad)),
+    {'EXIT',{badarg,[{erlang,length,[[I|_]],_}|_]}} = (catch erlang:Length(Bad)),
+    IncSeq = lists:seq(I + 1, I + Inc),
+    test_length(I+Inc, N, Inc,
+                lists:reverse(IncSeq, Good),
+                lists:reverse(IncSeq, Bad));
+test_length(_, _, _, _, _) -> ok.
+
+%% apply/3 with a fixed number of arguments didn't include all arguments on
+%% badarg exceptions.
+fixed_apply_badarg(Config) when is_list(Config) ->
+    Bad = id({}),
+
+    {'EXIT',{badarg, [{erlang,apply,[{},baz,[a,b]],[]} | _]}} =
+        (catch Bad:baz(a,b)),
+    {'EXIT',{badarg, [{erlang,apply,[baz,{},[c,d]],[]} | _]}} =
+        (catch baz:Bad(c,d)),
+
+    {'EXIT',{badarg, [{erlang,apply,[{},baz,[e,f]],[]} | _]}} =
+        (catch apply(Bad,baz,[e,f])),
+    {'EXIT',{badarg, [{erlang,apply,[baz,{},[g,h]],[]} | _]}} =
+        (catch apply(baz,Bad,[g,h])),
+
+    ok.
+
 %% helpers
     
 id(I) -> I.
diff --git a/erts/emulator/test/big_SUITE.erl b/erts/emulator/test/big_SUITE.erl
index 0a42b09903..3b9b9e5989 100644
--- a/erts/emulator/test/big_SUITE.erl
+++ b/erts/emulator/test/big_SUITE.erl
@@ -24,7 +24,7 @@
 
 -export([t_div/1, eq_28/1, eq_32/1, eq_big/1, eq_math/1, big_literals/1,
 	 borders/1, negative/1, big_float_1/1, big_float_2/1,
-         bxor_2pow/1,
+         bxor_2pow/1, band_2pow/1,
 	 shift_limit_1/1, powmod/1, system_limit/1, toobig/1, otp_6692/1]).
 
 %% Internal exports.
@@ -43,7 +43,7 @@ suite() ->
 all() -> 
     [t_div, eq_28, eq_32, eq_big, eq_math, big_literals,
      borders, negative, {group, big_float}, shift_limit_1,
-     bxor_2pow,
+     bxor_2pow, band_2pow,
      powmod, system_limit, toobig, otp_6692].
 
 groups() -> 
@@ -168,7 +168,11 @@ eval({op,_,Op,A0,B0}, LFH) ->
     Res = eval_op(Op, A, B),
     erlang:garbage_collect(),
     Res;
-eval({integer,_,I}, _) -> I;
+eval({integer,_,I}, _) ->
+    %% "Parasitic" ("symbiotic"?) test of squaring all numbers
+    %% found in the test data.
+    test_squaring(I),
+    I;
 eval({call,_,{atom,_,Local},Args0}, LFH) ->
     Args = eval_list(Args0, LFH),
     LFH(Local, Args).
@@ -192,6 +196,18 @@ eval_op('bxor', A, B) -> A bxor B;
 eval_op('bsl', A, B) -> A bsl B;
 eval_op('bsr', A, B) -> A bsr B.
 
+test_squaring(I) ->
+    %% Multiplying an integer by itself is specially optimized, so we
+    %% should take special care to test squaring.  The optimization
+    %% will kick in when the two operands have the same address.
+    Sqr = I * I,
+
+    %% This expression will be multiplied in the usual way, because
+    %% the the two operands for '*' are stored at different addresses.
+    Sqr = I * ((I + id(1)) - id(1)),
+
+    ok.
+
 %% Built in test functions
 
 fac(0) -> 1;
@@ -456,3 +472,38 @@ my_bxor(A, B, N, Acc0) ->
                false -> Acc0 bor (1 bsl N)
           end,
     my_bxor(A bsr 1, B bsr 1, N+1, Acc1).
+
+
+%% ERL-804
+band_2pow(_Config) ->
+    IL = lists:seq(8*3, 8*16, 4),
+    JL = lists:seq(0, 64),
+    [band_2pow_1((1 bsl I), (1 bsl J))
+     || I <- IL, J <- JL],
+    ok.
+
+band_2pow_1(A, B) ->
+    for(-1,1, fun(Ad) ->
+                      for(-1,1, fun(Bd) ->
+                                        band_2pow_2(A+Ad, B+Bd),
+                                        band_2pow_2(-A+Ad, B+Bd),
+                                        band_2pow_2(A+Ad, -B+Bd),
+                                        band_2pow_2(-A+Ad, -B+Bd)
+                                end)
+              end).
+
+band_2pow_2(A, B) ->
+    Correct = my_band(A, B),
+    case A band B of
+        Correct -> ok;
+        Wrong ->
+            io:format("~.16# band ~.16#\n", [A,B]),
+            io:format("Expected ~.16#\n", [Correct]),
+            io:format("Got      ~.16#\n", [Wrong]),
+            ct:fail({failed, 'band'})
+
+    end.
+
+%% Implement band without band
+my_band(A, B) ->
+    bnot ((bnot A) bor (bnot B)).
diff --git a/erts/emulator/test/binary_SUITE.erl b/erts/emulator/test/binary_SUITE.erl
index 23c675733c..fbd1325c3a 100644
--- a/erts/emulator/test/binary_SUITE.erl
+++ b/erts/emulator/test/binary_SUITE.erl
@@ -40,6 +40,7 @@
 %%
 
 -include_lib("common_test/include/ct.hrl").
+-include_lib("common_test/include/ct_event.hrl").
 
 -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
 	 init_per_group/2,end_per_group/2, 
@@ -50,6 +51,14 @@
 	 terms/1, terms_float/1, float_middle_endian/1,
          b2t_used_big/1,
 	 external_size/1, t_iolist_size/1,
+         t_iolist_size_huge_list/1,
+         t_iolist_size_huge_bad_arg_list/1,
+         t_iolist_size_shallow_trapping/1,
+         t_iolist_size_shallow_short_lists/1,
+         t_iolist_size_shallow_tiny_lists/1,
+         t_iolist_size_deep_trapping/1,
+         t_iolist_size_deep_short_lists/1,
+         t_iolist_size_deep_tiny_lists/1,
 	 t_hash/1,
 	 bad_size/1,
 	 bad_term_to_binary/1,
@@ -62,7 +71,8 @@
          term2bin_tuple_fallbacks/1,
          robustness/1,otp_8117/1,
 	 otp_8180/1, trapping/1, large/1,
-	 error_after_yield/1, cmp_old_impl/1]).
+	 error_after_yield/1, cmp_old_impl/1,
+         t2b_system_limit/1]).
 
 %% Internal exports.
 -export([sleeper/0,trapping_loop/4]).
@@ -70,15 +80,19 @@
 suite() -> [{ct_hooks,[ts_install_cth]},
 	    {timetrap,{minutes,4}}].
 
-all() -> 
+all() ->
     [copy_terms, conversions, deep_lists, deep_bitstr_lists,
      t_split_binary, bad_split,
      bad_list_to_binary, bad_binary_to_list, terms,
      terms_float, float_middle_endian, external_size, t_iolist_size,
+     t_iolist_size_huge_list,
+     t_iolist_size_huge_bad_arg_list,
+     {group, iolist_size_benchmarks},
      b2t_used_big,
      bad_binary_to_term_2, safe_binary_to_term2,
      bad_binary_to_term, bad_terms, t_hash, bad_size,
-     bad_term_to_binary, more_bad_terms, otp_5484, otp_5933,
+     bad_term_to_binary, t2b_system_limit, more_bad_terms,
+     otp_5484, otp_5933,
      ordering, unaligned_order, gc_test,
      bit_sized_binary_sizes, otp_6817, otp_8117, deep,
      term2bin_tuple_fallbacks,
@@ -86,13 +100,36 @@ all() ->
      error_after_yield, cmp_old_impl].
 
 groups() -> 
-    [].
+    [
+     {
+      iolist_size_benchmarks, 
+      [],
+      [t_iolist_size_shallow_trapping,
+       t_iolist_size_shallow_short_lists,
+       t_iolist_size_shallow_tiny_lists,
+       t_iolist_size_deep_trapping,
+       t_iolist_size_deep_short_lists,
+       t_iolist_size_deep_tiny_lists
+      ]
+     }
+    ].
 
 init_per_suite(Config) ->
+    A0 = case application:start(sasl) of
+	     ok -> [sasl];
+	     _ -> []
+	 end,
+    A = case application:start(os_mon) of
+	     ok -> [os_mon|A0];
+	     _ -> A0
+	 end,
+    [{started_apps, A}|Config].
+
+end_per_suite(Config) ->
+    As = proplists:get_value(started_apps, Config),
+    lists:foreach(fun (A) -> application:stop(A) end, As),
     Config.
 
-end_per_suite(_Config) ->
-    ok.
 
 init_per_group(_GroupName, Config) ->
     Config.
@@ -427,6 +464,54 @@ bad_term_to_binary(Config) when is_list(Config) ->
 
     ok.
 
+t2b_system_limit(Config) when is_list(Config) ->
+    case erlang:system_info(wordsize) of
+        8 ->
+            case proplists:get_value(system_total_memory,
+                                     memsup:get_system_memory_data()) of
+                Memory when is_integer(Memory),
+                            Memory > 6*1024*1024*1024 ->
+                    test_t2b_system_limit(),
+                    garbage_collect(),
+                    ok;
+                _ ->
+                    {skipped, "Not enough memory on this machine"}
+            end;
+        4 ->
+            {skipped, "Only interesting on 64-bit builds"}
+    end.
+
+test_t2b_system_limit() ->
+    io:format("Creating HugeBin~n", []),
+    Bits = ((1 bsl 32)+1)*8,
+    HugeBin = <<0:Bits>>,
+
+    io:format("Testing term_to_binary(HugeBin)~n", []),
+    {'EXIT',{system_limit,[{erlang,term_to_binary,
+                            [HugeBin],
+                            _} |_]}} = (catch term_to_binary(HugeBin)),
+
+    io:format("Testing term_to_binary(HugeBin, [compressed])~n", []),
+    {'EXIT',{system_limit,[{erlang,term_to_binary,
+                            [HugeBin, [compressed]],
+                            _} |_]}} = (catch term_to_binary(HugeBin, [compressed])),
+
+    %% Check that it works also after we have trapped...
+    io:format("Creating HugeListBin~n", []),
+    HugeListBin = [lists:duplicate(2000000,2000000), HugeBin],
+
+    io:format("Testing term_to_binary(HugeListBin)~n", []),
+    {'EXIT',{system_limit,[{erlang,term_to_binary,
+                            [HugeListBin],
+                            _} |_]}} = (catch term_to_binary(HugeListBin)),
+
+    io:format("Testing term_to_binary(HugeListBin, [compressed])~n", []),
+    {'EXIT',{system_limit,[{erlang,term_to_binary,
+                            [HugeListBin, [compressed]],
+                            _} |_]}} = (catch term_to_binary(HugeListBin, [compressed])),
+
+    ok.
+
 %% Tests binary_to_term/1 and term_to_binary/1.
 
 terms(Config) when is_list(Config) ->
@@ -615,6 +700,143 @@ build_iolist(N0, Base) ->
 	    [47,L,L|Seq]
     end.
 
+approx_4GB_bin() ->
+    Bin = lists:duplicate(4194304, 255),
+    BinRet = erlang:iolist_to_binary(lists:duplicate(1124, Bin)),
+    BinRet.
+
+duplicate_iolist(IOList, 0) ->
+    IOList;
+duplicate_iolist(IOList, NrOfTimes) ->
+    duplicate_iolist([IOList, IOList], NrOfTimes - 1).
+
+t_iolist_size_huge_list(Config)  when is_list(Config) ->
+    run_when_enough_resources(
+      fun() ->
+              {TimeToCreateIOList, IOList} = timer:tc(fun()->duplicate_iolist(approx_4GB_bin(), 32) end),
+              {IOListSizeTime, CalculatedSize} = timer:tc(fun()->erlang:iolist_size(IOList) end),
+              20248183924657750016 = CalculatedSize,
+              {comment, io_lib:format("Time to create iolist: ~f s. Time to calculate size: ~f s.", 
+                                      [TimeToCreateIOList / 1000000, IOListSizeTime / 1000000])}
+      end).
+
+t_iolist_size_huge_bad_arg_list(Config)  when is_list(Config) ->
+    run_when_enough_resources(
+      fun() ->
+              P = self(),
+              spawn_link(fun()-> IOListTmp = duplicate_iolist(approx_4GB_bin(), 32),
+                                 IOList = [IOListTmp, [badarg]],
+                                 {'EXIT',{badarg,_}} = (catch erlang:iolist_size(IOList)),
+                                 P ! ok
+                         end),
+              receive ok -> ok end
+         end).
+
+%% iolist_size tests for shallow lists
+
+t_iolist_size_shallow_trapping(Config) when is_list(Config) ->
+    Lengths = [2000, 20000, 200000, 200000, 2000000, 20000000],
+    run_iolist_size_test_and_benchmark(Lengths, fun make_shallow_iolist/2).
+
+t_iolist_size_shallow_short_lists(Config) when is_list(Config) ->
+    Lengths = lists:duplicate(15000, 300),
+    run_iolist_size_test_and_benchmark(Lengths, fun make_shallow_iolist/2).
+
+t_iolist_size_shallow_tiny_lists(Config) when is_list(Config) ->
+    Lengths = lists:duplicate(250000, 18),
+    run_iolist_size_test_and_benchmark(Lengths, fun make_shallow_iolist/2).
+
+make_shallow_iolist(SizeDiv2, LastItem) ->
+    lists:map(
+      fun(I) -> 
+              case I of
+                  SizeDiv2 -> [1, LastItem];
+                  _ -> [1, 1]
+              end
+      end,
+      lists:seq(1, SizeDiv2)).
+
+%% iolist_size tests for deep lists
+
+t_iolist_size_deep_trapping(Config) when is_list(Config) ->
+    Lengths = [2000, 20000, 200000, 200000, 2000000, 10000000],
+    run_iolist_size_test_and_benchmark(Lengths, fun make_deep_iolist/2).
+
+t_iolist_size_deep_short_lists(Config) when is_list(Config) ->
+    Lengths = lists:duplicate(10000, 300),
+    run_iolist_size_test_and_benchmark(Lengths, fun make_deep_iolist/2).
+
+t_iolist_size_deep_tiny_lists(Config) when is_list(Config) ->
+    Lengths = lists:duplicate(150000, 18),
+    run_iolist_size_test_and_benchmark(Lengths, fun make_deep_iolist/2).
+
+make_deep_iolist(1, LastItem) ->
+    [1, LastItem];
+make_deep_iolist(Depth, LastItem) ->
+    [[1, 1], make_deep_iolist(Depth - 1, LastItem)].
+
+% Helper functions for iolist_size tests
+
+run_iolist_size_test_and_benchmark(Lengths, ListGenerator) ->
+    run_when_enough_resources(
+      fun() ->
+              GoodListsWithSizes =
+                  lists:map(fun(Length) -> {Length*2, ListGenerator(Length, 1)} end, Lengths),
+              BadListsWithSizes =
+                  lists:map(fun(Length) -> {Length*2, ListGenerator(Length, bad)} end, Lengths),
+              erlang:garbage_collect(),
+              report_throughput(
+                fun() ->
+                        lists:foreach(
+                          fun(_)->
+                                  lists:foreach(
+                                    fun({Size, List}) -> Size = iolist_size(List) end,
+                                    GoodListsWithSizes),
+                                  lists:foreach(
+                                    fun({_, List}) -> {'EXIT',_} = (catch (iolist_size(List))) end,
+                                    BadListsWithSizes)
+                          end,
+                          lists:seq(1,3))
+                end,
+                lists:sum(Lengths)*4)
+      end).
+
+report_throughput(Fun, NrOfItems) ->
+    Parent = self(),
+    spawn(fun() -> Parent ! timer:tc(Fun) end),
+    {Time, _} = receive D -> D end,
+    ItemsPerMicrosecond = NrOfItems / Time,
+    ct_event:notify(#event{ name = benchmark_data, data = [{value, ItemsPerMicrosecond}]}),
+    {comment, io_lib:format("Items per microsecond: ~p, Nr of items: ~p, Benchmark time: ~p seconds)",
+                            [ItemsPerMicrosecond, NrOfItems, Time/1000000])}.
+
+total_memory() ->
+    %% Total memory in GB.
+    try
+	MemoryData = memsup:get_system_memory_data(),
+	case lists:keysearch(total_memory, 1, MemoryData) of
+	    {value, {total_memory, TM}} ->
+		TM div (1024*1024*1024);
+	    false ->
+		{value, {system_total_memory, STM}} =
+		    lists:keysearch(system_total_memory, 1, MemoryData),
+		STM div (1024*1024*1024)
+	end
+    catch
+	_ : _ ->
+	    undefined
+    end.
+
+run_when_enough_resources(Fun) ->
+    case {total_memory(), erlang:system_info(wordsize)} of
+        {Mem, 8} when is_integer(Mem) andalso Mem >= 15 ->
+            Fun();
+        {Mem, WordSize} ->
+            {skipped, 
+             io_lib:format("Not enough resources (System Memory >= ~p, Word Size = ~p)",
+                           [Mem, WordSize])}
+    end.
+    
 
 %% OTP-4053
 bad_binary_to_term_2(Config) when is_list(Config) ->
@@ -1216,7 +1438,8 @@ sleeper() ->
 gc_test(Config) when is_list(Config) ->
     %% Note: This test is only relevant for REFC binaries.
     %% Therefore, we take care that all binaries are REFC binaries.
-    B = list_to_binary(lists:seq(0, ?heap_binary_size)),
+    true = 192 > ?heap_binary_size,
+    B = list_to_binary(lists:seq(1, 192)),
     Self = self(),
     F1 = fun() ->
 		 gc(),
@@ -1225,22 +1448,22 @@ gc_test(Config) when is_list(Config) ->
 	 end,
     F = fun() ->
 		receive go -> ok end,
-		{binary,[{_,65,1}]} = process_info(self(), binary),
+		{binary,[{_,192,1}]} = process_info(self(), binary),
 		gc(),
-		{B1,B2} = my_split_binary(B, 4),
+		{B1,B2} = my_split_binary(B, 68),
 		gc(),
 		gc(),
 		{binary,L1} = process_info(self(), binary),
 		[Binfo1,Binfo2,Binfo3] = L1,
-		{_,65,3} = Binfo1 = Binfo2 = Binfo3,
-		65 = size(B),
-		4 = size(B1),
-		61 = size(B2),
+		{_,192,3} = Binfo1 = Binfo2 = Binfo3,
+		192 = size(B),
+		68 = size(B1),
+		124 = size(B2),
 		F1()
 	end,
     gc(),
     gc(),
-    65 = size(B),
+    192 = size(B),
     gc_test1(spawn_opt(erlang, apply, [F,[]], [link,{fullsweep_after,0}])).
 
 gc_test1(Pid) ->
@@ -1531,13 +1754,16 @@ error_after_yield_bad_ext_term() ->
 		    BadAtomExt]). %% Invalid atom at the end
 	    
 cmp_old_impl(Config) when is_list(Config) ->
-    %% Compare results from new yielding implementations with
-    %% old non yielding implementations 
+    %% This test was originally a comparison with the non yielding
+    %% implementation in R16B. Since OTP 22 we can't talk distribution with such
+    %% old nodes (< 19). The test case it kept but compares with previous major
+    %% version for semantic regression test.
     Cookie = atom_to_list(erlang:get_cookie()),
-    Rel = "r16b_latest",
+    Rel = (integer_to_list(list_to_integer(erlang:system_info(otp_release)) - 1)
+           ++ "_latest"),
     case test_server:is_release_available(Rel) of
 	false ->
-	    {skipped, "No "++Rel++" available"};
+	    {skipped, "No OTP "++Rel++" available"};
 	true ->
 	    {ok, Node} = test_server:start_node(list_to_atom(atom_to_list(?MODULE)++"_"++Rel),
 				       peer,
diff --git a/erts/emulator/test/bs_construct_SUITE.erl b/erts/emulator/test/bs_construct_SUITE.erl
index ce50bcdd86..8fab4f5bc4 100644
--- a/erts/emulator/test/bs_construct_SUITE.erl
+++ b/erts/emulator/test/bs_construct_SUITE.erl
@@ -16,8 +16,6 @@
 %% limitations under the License.
 %% 
 %% %CopyrightEnd%
-%%
-%% Purpose : Common utilities used by several optimization passes.
 %% 
 
 -module(bs_construct_SUITE).
@@ -26,10 +24,10 @@
          init_per_suite/1, end_per_suite/1,
 	 test1/1, test2/1, test3/1, test4/1, test5/1, testf/1,
 	 not_used/1, in_guard/1,
-	 mem_leak/1, coerce_to_float/1, bjorn/1,
-	 huge_float_field/1, huge_binary/1, system_limit/1, badarg/1,
+	 mem_leak/1, coerce_to_float/1, bjorn/1, append_empty_is_same/1,
+	 huge_float_field/1, system_limit/1, badarg/1,
 	 copy_writable_binary/1, kostis/1, dynamic/1, bs_add/1,
-	 otp_7422/1, zero_width/1, bad_append/1, bs_add_overflow/1]).
+	 otp_7422/1, zero_width/1, bad_append/1, bs_append_overflow/1]).
 
 -include_lib("common_test/include/ct.hrl").
 
@@ -39,10 +37,10 @@ suite() ->
 
 all() -> 
     [test1, test2, test3, test4, test5, testf, not_used,
-     in_guard, mem_leak, coerce_to_float, bjorn,
-     huge_float_field, huge_binary, system_limit, badarg,
+     in_guard, mem_leak, coerce_to_float, bjorn, append_empty_is_same,
+     huge_float_field, system_limit, badarg,
      copy_writable_binary, kostis, dynamic, bs_add, otp_7422, zero_width,
-     bad_append, bs_add_overflow].
+     bad_append, bs_append_overflow].
 
 init_per_suite(Config) ->
     Config.
@@ -520,6 +518,16 @@ do_more(Bin, Sz) ->
 do_something() ->
     throw(blurf).
 
+append_empty_is_same(Config) when is_list(Config) ->
+    NonWritableBin = <<"123">>,
+    true = erts_debug:same(NonWritableBin, append(NonWritableBin, <<>>)),
+    WritableBin = <<(id(<<>>))/binary,0,1,2,3,4,5,6,7>>,
+    true = erts_debug:same(WritableBin, append(WritableBin, <<>>)),
+    ok.
+
+append(A, B) ->
+    <<A/binary, B/binary>>.
+
 huge_float_field(Config) when is_list(Config) ->
     {'EXIT',{badarg,_}} = (catch <<0.0:9/float-unit:8>>),
     huge_float_check(catch <<0.0:67108865/float-unit:64>>),
@@ -533,56 +541,6 @@ huge_float_field(Config) when is_list(Config) ->
 huge_float_check({'EXIT',{system_limit,_}}) -> ok;
 huge_float_check({'EXIT',{badarg,_}}) -> ok.
 
-huge_binary(Config) when is_list(Config) ->
-    ct:timetrap({seconds, 60}),
-    16777216 = size(<<0:(id(1 bsl 26)),(-1):(id(1 bsl 26))>>),
-    garbage_collect(),
-    FreeMem = free_mem(),
-    io:format("Free memory (Mb): ~p\n", [FreeMem]),
-    {Shift,Return} = case free_mem() of
-			 undefined ->
-			     %% This test has to be inlined inside the case to
-			     %% use a literal Shift
-			     garbage_collect(),
-			     id(<<0:((1 bsl 32)-1)>>),
-			     {32,ok};
-			 Mb when Mb > 600 ->
-			     garbage_collect(),
-			     id(<<0:((1 bsl 32)-1)>>),
-			     {32,ok};
-			 Mb when Mb > 300 ->
-			     garbage_collect(),
-			     id(<<0:((1 bsl 31)-1)>>),
-			     {31,"Limit huge binaries to 256 Mb"};
-			 Mb when Mb > 200 ->
-			     garbage_collect(),
-			     id(<<0:((1 bsl 30)-1)>>),
-			     {30,"Limit huge binary to 128 Mb"};
-			 _ ->
-			     garbage_collect(),
-			     id(<<0:((1 bsl 29)-1)>>),
-                             {29,"Limit huge binary to 64 Mb"}
-		     end,
-    garbage_collect(),
-    id(<<0:((1 bsl Shift)-1)>>),
-    garbage_collect(),
-    id(<<0:(id((1 bsl Shift)-1))>>),
-    garbage_collect(),
-    case Return of
-	ok -> ok;	     
-	Comment -> {comment, Comment}
-    end.
-
-%% Return the amount of free memory in Mb.
-free_mem() ->
-    {ok,Apps} = application:ensure_all_started(os_mon),
-    Mem = memsup:get_system_memory_data(),
-    [ok = application:stop(App)||App <- Apps],
-    case proplists:get_value(free_memory,Mem) of
-        undefined -> undefined;
-        Val -> Val div (1024*1024)
-    end.
-
 system_limit(Config) when is_list(Config) ->
     WordSize = erlang:system_info(wordsize),
     BitsPerWord = WordSize * 8,
@@ -894,33 +852,37 @@ append_unit_8(Bin) ->
 append_unit_16(Bin) ->
     <<Bin/binary-unit:16,0:1>>.
 
-%% Produce a large result of bs_add that, if cast to signed int, would overflow
-%% into a negative number that fits a smallnum.
-bs_add_overflow(_Config) ->
+%% Test that the bs_append instruction will correctly check for
+%% overflow by producing a binary whose total size would exceed the
+%% maximum allowed size for a binary on a 32-bit computer.
+
+bs_append_overflow(_Config) ->
     Memsize = memsize(),
     io:format("Memsize = ~w Bytes~n", [Memsize]),
     case erlang:system_info(wordsize) of
 	8 ->
+            %% Not possible to test on a 64-bit computer.
 	    {skip, "64-bit architecture"};
         _ when Memsize < (2 bsl 30) ->
-	    {skip, "Less then 2 GB of memory"};
+	    {skip, "Less than 2 GB of memory"};
 	4 ->
-            {'EXIT', {system_limit, _}} = (catch bs_add_overflow_signed()),
-            {'EXIT', {system_limit, _}} = (catch bs_add_overflow_unsigned()),
+            {'EXIT', {system_limit, _}} = (catch bs_append_overflow_signed()),
+            erlang:garbage_collect(),
+            {'EXIT', {system_limit, _}} = (catch bs_append_overflow_unsigned()),
+            erlang:garbage_collect(),
 	    ok
     end.
 
-bs_add_overflow_signed() ->
-    %% Produce a large result of bs_add that, if cast to signed int, would
+bs_append_overflow_signed() ->
+    %% Produce a large binary that, if cast to signed int, would
     %% overflow into a negative number that fits a smallnum.
     Large = <<0:((1 bsl 30)-1)>>,
     <<Large/bits, Large/bits, Large/bits, Large/bits,
       Large/bits, Large/bits, Large/bits, Large/bits,
       Large/bits>>.
 
-bs_add_overflow_unsigned() ->
-    %% Produce a large result of bs_add that goes beyond the limit of an
-    %% unsigned word. This used to succeed but produced an incorrect result
+bs_append_overflow_unsigned() ->
+    %% The following would succeed but would produce an incorrect result
     %% where B =:= C!
     A = <<0:((1 bsl 32)-8)>>,
     B = <<2, 3>>,
diff --git a/erts/emulator/test/bs_match_int_SUITE.erl b/erts/emulator/test/bs_match_int_SUITE.erl
index e913dc98b0..454e55d017 100644
--- a/erts/emulator/test/bs_match_int_SUITE.erl
+++ b/erts/emulator/test/bs_match_int_SUITE.erl
@@ -234,34 +234,49 @@ mml_choose(<<_A:8>>) -> single_byte_binary;
 mml_choose(<<_A:8,_T/binary>>) -> multi_byte_binary.
 
 match_huge_int(Config) when is_list(Config) ->
-    Sz = 1 bsl 27,
-    Bin = <<0:Sz,13:8>>,
-    skip_huge_int_1(Sz, Bin),
-    0 = match_huge_int_1(Sz, Bin),
-
-    %% Test overflowing the size of an integer field.
-    nomatch = overflow_huge_int_skip_32(Bin),
-    case erlang:system_info(wordsize) of
-	4 ->
-	    nomatch = overflow_huge_int_32(Bin);
-	8 ->
-	    %% An attempt will be made to allocate heap space for
-	    %% the bignum (which will probably fail); only if the
-	    %% allocation succeeds will the matching fail because
-	    %% the binary is too small.
-	    ok
-    end,
-    nomatch = overflow_huge_int_skip_64(Bin),
-    nomatch = overflow_huge_int_64(Bin),
-
-    %% Test overflowing the size of an integer field using variables as sizes.
-    Sizes = case erlang:system_info(wordsize) of
-		      4 -> lists:seq(25, 32);
-		      8 -> []
-		  end ++ lists:seq(50, 64),
-    ok = overflow_huge_int_unit128(Bin, Sizes),
-
-    ok.
+    case ?MODULE of
+        bs_match_int_no_opt_SUITE ->
+            %% This test case is written with the assumption that
+            %% bs_skip2 instructions are used when the value of the
+            %% extracted segment will not be used. In OTP 21 and earlier, that
+            %% assumption was always true, because the bs_skip optimization
+            %% was included in v3_codegen and could not be disabled.
+            %% In OTP 22, the bs_skip optimization is done by beam_ssa_opt
+            %% and is disabled.
+            %%
+            %% On memory-constrained computers, using bs_get_integer2
+            %% instructions may cause the runtime system to terminate
+            %% because of insufficient memory.
+            {skip, "unoptimized code would use too much memory"};
+        bs_match_int_SUITE ->
+            Sz = 1 bsl 27,
+            Bin = <<0:Sz,13:8>>,
+            skip_huge_int_1(Sz, Bin),
+            0 = match_huge_int_1(Sz, Bin),
+
+            %% Test overflowing the size of an integer field.
+            nomatch = overflow_huge_int_skip_32(Bin),
+            case erlang:system_info(wordsize) of
+                4 ->
+                    nomatch = overflow_huge_int_32(Bin);
+                8 ->
+                    %% An attempt will be made to allocate heap space for
+                    %% the bignum (which will probably fail); only if the
+                    %% allocation succeeds will the matching fail because
+                    %% the binary is too small.
+                    ok
+            end,
+            nomatch = overflow_huge_int_skip_64(Bin),
+            nomatch = overflow_huge_int_64(Bin),
+
+            %% Test overflowing the size of an integer field using
+            %% variables as sizes.
+            Sizes = case erlang:system_info(wordsize) of
+                        4 -> lists:seq(25, 32);
+                        8 -> []
+                    end ++ lists:seq(50, 64),
+            ok = overflow_huge_int_unit128(Bin, Sizes)
+    end.
 
 overflow_huge_int_unit128(Bin, [Sz0|Sizes]) ->
     Sz = id(1 bsl Sz0),
diff --git a/erts/emulator/test/bs_match_misc_SUITE.erl b/erts/emulator/test/bs_match_misc_SUITE.erl
index 17759d78f3..cae4eb54d2 100644
--- a/erts/emulator/test/bs_match_misc_SUITE.erl
+++ b/erts/emulator/test/bs_match_misc_SUITE.erl
@@ -24,7 +24,7 @@
 	 kenneth/1,encode_binary/1,native/1,happi/1,
 	 size_var/1,wiger/1,x0_context/1,huge_float_field/1,
 	 writable_binary_matched/1,otp_7198/1,unordered_bindings/1,
-	 float_middle_endian/1]).
+	 float_middle_endian/1,unsafe_get_binary_reuse/1]).
 
 -include_lib("common_test/include/ct.hrl").
 
@@ -36,7 +36,8 @@ all() ->
     [bound_var, bound_tail, t_float, little_float, sean,
      kenneth, encode_binary, native, happi, size_var, wiger,
      x0_context, huge_float_field, writable_binary_matched,
-     otp_7198, unordered_bindings, float_middle_endian].
+     otp_7198, unordered_bindings, float_middle_endian,
+     unsafe_get_binary_reuse].
 
 
 %% Test matching of bound variables.
@@ -556,5 +557,21 @@ unordered_bindings(CompressedLength, HashSize, PadLength, T) ->
      Padding:PadLength/binary,PadLength>> = T,
     {Content,Mac,Padding}.
 
+%% ERL-901: A load-time optimization assumed that match contexts had no further
+%% uses when a bs_get_binary2 overwrote the match context's register, and
+%% figured it would be safe to reuse the match context's memory for the
+%% resulting binary.
+%%
+%% This is no longer safe as of OTP 22, as a match context may be reused after
+%% being passed to another function.
+unsafe_get_binary_reuse(Config) when is_list(Config) ->
+    <<_First, Rest/binary>> = <<"hello">>,
+    ubgr_1(Rest),
+    <<Second,_/bits>> = Rest,
+    $e = Second,
+    ok.
+
+ubgr_1(<<_CP/utf8, Rest/binary>>) -> id(Rest);
+ubgr_1(_) -> false.
 
 id(I) -> I.
diff --git a/erts/emulator/test/call_trace_SUITE.erl b/erts/emulator/test/call_trace_SUITE.erl
index d19f7f81ad..742592f88e 100644
--- a/erts/emulator/test/call_trace_SUITE.erl
+++ b/erts/emulator/test/call_trace_SUITE.erl
@@ -1395,7 +1395,7 @@ seq(M, N, R) when M =< N ->
     seq(M, N-1, [N|R]);
 seq(_, _, R) -> R.
 
-%% lists:reverse can not be called since it is traced
+%% lists:reverse cannot be called since it is traced
 reverse(L) ->
     reverse(L, []).
 %%
diff --git a/erts/emulator/test/code_SUITE.erl b/erts/emulator/test/code_SUITE.erl
index 0444ba4f89..493c6ebe99 100644
--- a/erts/emulator/test/code_SUITE.erl
+++ b/erts/emulator/test/code_SUITE.erl
@@ -332,6 +332,7 @@ constant_pools(Config) when is_list(Config) ->
     A = literals:a(),
     B = literals:b(),
     C = literals:huge_bignum(),
+    D = literals:funs(),
     process_flag(trap_exit, true),
     Self = self(),
 
@@ -345,7 +346,7 @@ constant_pools(Config) when is_list(Config) ->
     true = erlang:purge_module(literals),
     NoOldHeap ! done,
     receive
-        {'EXIT',NoOldHeap,{A,B,C}} ->
+        {'EXIT',NoOldHeap,{A,B,C,D}} ->
             ok;
         Other ->
             ct:fail({unexpected,Other})
@@ -362,7 +363,7 @@ constant_pools(Config) when is_list(Config) ->
     erlang:purge_module(literals),
     OldHeap ! done,
     receive
-	{'EXIT',OldHeap,{A,B,C,[1,2,3|_]=Seq}} when length(Seq) =:= 16 ->
+	{'EXIT',OldHeap,{A,B,C,D,[1,2,3|_]=Seq}} when length(Seq) =:= 16 ->
 	    ok
     end,
 
@@ -390,7 +391,7 @@ constant_pools(Config) when is_list(Config) ->
 	{'DOWN', Mon, process, Hib, Reason} ->
 	    {undef, [{no_module,
 		      no_function,
-		      [{A,B,C,[1,2,3|_]=Seq}], _}]} = Reason,
+		      [{A,B,C,D,[1,2,3|_]=Seq}], _}]} = Reason,
 	    16 = length(Seq)
     end,
     HeapSz = TotHeapSz, %% Ensure restored to hibernated state...
@@ -400,7 +401,9 @@ constant_pools(Config) when is_list(Config) ->
 no_old_heap(Parent) ->
     A = literals:a(),
     B = literals:b(),
-    Res = {A,B,literals:huge_bignum()},
+    C = literals:huge_bignum(),
+    D = literals:funs(),
+    Res = {A,B,C,D},
     Parent ! go,
     receive
         done ->
@@ -410,7 +413,9 @@ no_old_heap(Parent) ->
 old_heap(Parent) ->
     A = literals:a(),
     B = literals:b(),
-    Res = {A,B,literals:huge_bignum(),lists:seq(1, 16)},
+    C = literals:huge_bignum(),
+    D = literals:funs(),
+    Res = {A,B,C,D,lists:seq(1, 16)},
     create_old_heap(),
     Parent ! go,
     receive
@@ -421,7 +426,9 @@ old_heap(Parent) ->
 hibernated(Parent) ->
     A = literals:a(),
     B = literals:b(),
-    Res = {A,B,literals:huge_bignum(),lists:seq(1, 16)},
+    C = literals:huge_bignum(),
+    D = literals:funs(),
+    Res = {A,B,C,D,lists:seq(1, 16)},
     Parent ! go,
     erlang:hibernate(no_module, no_function, [Res]).
 
@@ -755,7 +762,8 @@ t_copy_literals_frags(Config) when is_list(Config) ->
                                           0, 1, 2, 3, 4, 5, 6, 7,
                                           8, 9,10,11,12,13,14,15,
                                           0, 1, 2, 3, 4, 5, 6, 7,
-                                          8, 9,10,11,12,13,14,15>>}]),
+                                          8, 9,10,11,12,13,14,15>>},
+                        {f, fun ?MODULE:all/0}]),
 
     {module, ?mod} = erlang:load_module(?mod, Bin),
     N = 6000,
@@ -796,6 +804,7 @@ literal_receiver() ->
             C = ?mod:c(),
             D = ?mod:d(),
             E = ?mod:e(),
+            F = ?mod:f(),
             literal_receiver();
         {Pid, sender_confirm} ->
             io:format("sender confirm ~w~n", [Pid]),
@@ -811,7 +820,8 @@ literal_sender(N, Recv) ->
                           ?mod:b(),
                           ?mod:c(),
                           ?mod:d(),
-                          ?mod:e()]},
+                          ?mod:e(),
+                          ?mod:f()]},
     literal_sender(N - 1, Recv).
 
 literal_switcher() ->
diff --git a/erts/emulator/test/code_SUITE_data/literals.erl b/erts/emulator/test/code_SUITE_data/literals.erl
index 7c3b0ebe73..13c8b412b0 100644
--- a/erts/emulator/test/code_SUITE_data/literals.erl
+++ b/erts/emulator/test/code_SUITE_data/literals.erl
@@ -19,7 +19,8 @@
 %%
 
 -module(literals).
--export([a/0,b/0,huge_bignum/0,binary/0,unused_binaries/0,bits/0]).
+-export([a/0,b/0,huge_bignum/0,funs/0,
+         binary/0,unused_binaries/0,bits/0]).
 -export([msg1/0,msg2/0,msg3/0,msg4/0,msg5/0]).
 
 a() ->
@@ -108,3 +109,8 @@ msg2() -> {"hello","world"}.
 msg3() -> <<"halloj">>.
 msg4() -> #{ 1=> "hello", b => "world"}.
 msg5() -> {1,2,3,4,5,6}.
+
+funs() ->
+    %% Literal funs (in a non-literal list).
+    [fun ?MODULE:a/0,
+     fun() -> ok end].                          %No environment.
diff --git a/erts/emulator/test/dirty_bif_SUITE.erl b/erts/emulator/test/dirty_bif_SUITE.erl
index 46eb0cba58..4f5ad0295a 100644
--- a/erts/emulator/test/dirty_bif_SUITE.erl
+++ b/erts/emulator/test/dirty_bif_SUITE.erl
@@ -38,7 +38,8 @@
 	 dirty_process_info/1,
 	 dirty_process_register/1,
 	 dirty_process_trace/1,
-	 code_purge/1]).
+	 code_purge/1,
+         otp_15688/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
@@ -64,7 +65,8 @@ all() ->
      dirty_process_info,
      dirty_process_register,
      dirty_process_trace,
-     code_purge].
+     code_purge,
+     otp_15688].
 
 init_per_suite(Config) ->
     case erlang:system_info(dirty_cpu_schedulers) of
@@ -498,10 +500,58 @@ code_purge(Config) when is_list(Config) ->
     true = Time =< 1000,
     ok.
 
+otp_15688(Config) when is_list(Config) ->
+    ImBack = make_ref(),
+    {See, SeeMon} = spawn_monitor(fun () ->
+                                          erts_debug:dirty_io(wait, 2000),
+                                          exit(ImBack)
+                                  end),
+    wait_until(fun () ->
+                       [{current_function, {erts_debug, dirty_io, 2}},
+                        {status, running}]
+                           == process_info(See,
+                                           [current_function, status])
+               end),
+    {Ser1, Ser1Mon} = spawn_monitor(fun () ->
+                                            erlang:suspend_process(See,
+                                                                   [asynchronous])
+                                    end),
+    erlang:suspend_process(See, [asynchronous]),
+    receive {'DOWN', Ser1Mon, process, Ser1, normal} -> ok end,
+
+    %% Verify that we sent the suspend request while it was executing dirty...
+    [{current_function, {erts_debug, dirty_io, 2}},
+     {status, running}] = process_info(See, [current_function, status]),
+
+    wait_until(fun () ->
+                       {status, suspended} == process_info(See, status)
+               end),
+    erlang:resume_process(See),
+
+    receive
+        {'DOWN', SeeMon, process, See, Reason} ->
+            ImBack = Reason
+    after 4000 ->
+            %% Resume bug seems to have hit us...
+            PI = process_info(See),
+            exit(See, kill),
+            ct:fail({suspendee_stuck, PI})
+    end.
+    
+
 %%
 %% Internal...
 %%
 
+wait_until(Fun) ->
+    case Fun() of
+        true ->
+            ok;
+        _ ->
+            receive after 100 -> ok end,
+            wait_until(Fun)
+    end.
+
 access_dirty_process(Config, Start, Test, Finish) ->
     {ok, Node} = start_node(Config, ""),
     [ok] = mcall(Node,
diff --git a/erts/emulator/test/distribution_SUITE.erl b/erts/emulator/test/distribution_SUITE.erl
index 885c66331c..9dcdd60060 100644
--- a/erts/emulator/test/distribution_SUITE.erl
+++ b/erts/emulator/test/distribution_SUITE.erl
@@ -19,7 +19,6 @@
 %%
 
 -module(distribution_SUITE).
--compile(r16).
 
 -define(VERSION_MAGIC,       131).
 
@@ -39,6 +38,8 @@
 -define(Line,).
 
 -export([all/0, suite/0, groups/0,
+         init_per_suite/1, end_per_suite/1,
+         init_per_group/2, end_per_group/2,
          ping/1, bulk_send_small/1,
          group_leader/1,
          optimistic_dflags/1,
@@ -53,7 +54,6 @@
          dist_parallel_send/1,
          atom_roundtrip/1,
          unicode_atom_roundtrip/1,
-         atom_roundtrip_r16b/1,
          contended_atom_cache_entry/1,
          contended_unicode_atom_cache_entry/1,
          bad_dist_structure/1,
@@ -62,7 +62,13 @@
          bad_dist_ext_control/1,
          bad_dist_ext_connection_id/1,
          bad_dist_ext_size/1,
-	 start_epmd_false/1, epmd_module/1]).
+	 start_epmd_false/1, epmd_module/1,
+         bad_dist_fragments/1,
+         message_latency_large_message/1,
+         message_latency_large_link_exit/1,
+         message_latency_large_monitor_exit/1,
+         message_latency_large_exit2/1,
+         system_limit/1]).
 
 %% Internal exports.
 -export([sender/3, receiver2/2, dummy_waiter/0, dead_process/0,
@@ -70,7 +76,7 @@
          optimistic_dflags_echo/0, optimistic_dflags_sender/1,
          roundtrip/1, bounce/1, do_dist_auto_connect/1, inet_rpc_server/1,
          dist_parallel_sender/3, dist_parallel_receiver/0,
-         dist_evil_parallel_receiver/0]).
+         dist_evil_parallel_receiver/0, make_busy/2]).
 
 %% epmd_module exports
 -export([start_link/0, register_node/2, register_node/3, port_please/2, address_please/3]).
@@ -88,10 +94,10 @@ all() ->
      ref_port_roundtrip, nil_roundtrip, stop_dist,
      {group, trap_bif}, {group, dist_auto_connect},
      dist_parallel_send, atom_roundtrip, unicode_atom_roundtrip,
-     atom_roundtrip_r16b,
      contended_atom_cache_entry, contended_unicode_atom_cache_entry,
-     bad_dist_structure, {group, bad_dist_ext},
-     start_epmd_false, epmd_module].
+     {group, message_latency},
+     {group, bad_dist}, {group, bad_dist_ext},
+     start_epmd_false, epmd_module, system_limit].
 
 groups() ->
     [{bulk_send, [], [bulk_send_small, bulk_send_big, bulk_send_bigbig]},
@@ -100,10 +106,40 @@ groups() ->
      {trap_bif, [], [trap_bif_1, trap_bif_2, trap_bif_3]},
      {dist_auto_connect, [],
       [dist_auto_connect_never, dist_auto_connect_once]},
+     {bad_dist, [],
+      [bad_dist_structure, bad_dist_fragments]},
      {bad_dist_ext, [],
       [bad_dist_ext_receive, bad_dist_ext_process_info,
        bad_dist_ext_size,
-       bad_dist_ext_control, bad_dist_ext_connection_id]}].
+       bad_dist_ext_control, bad_dist_ext_connection_id]},
+     {message_latency, [],
+      [message_latency_large_message,
+       message_latency_large_link_exit,
+       message_latency_large_monitor_exit,
+       message_latency_large_exit2]}
+    ].
+
+init_per_suite(Config) ->
+    {ok, Apps} = application:ensure_all_started(os_mon),
+    [{started_apps, Apps} | Config].
+
+end_per_suite(Config) ->
+    Apps = proplists:get_value(started_apps, Config),
+    [application:stop(App) || App <- lists:reverse(Apps)],
+    Config.
+
+init_per_group(message_latency, Config) ->
+    Free = free_memory(),
+    if Free < 2048 ->
+            {skip, "Not enough memory"};
+       true ->
+            Config
+    end;
+init_per_group(_, Config) ->
+    Config.
+
+end_per_group(_, Config) ->
+    Config.
 
 %% Tests pinging a node in different ways.
 ping(Config) when is_list(Config) ->
@@ -568,10 +604,20 @@ do_busy_test(Node, Fun) ->
             %% Don't match arity; it is different in debug and
             %% optimized emulator
             [{status, suspended},
-             {current_function, {erlang, bif_return_trap, _}}] = Pinfo,
+             {current_function, {Mod, Func, _}}] = Pinfo,
+            if
+                Mod =:= erlang andalso Func =:= bif_return_trap ->
+                    true;
+                Mod =:= erts_internal andalso Func =:= dsend_continue_trap ->
+                    true;
+                true ->
+                    ct:fail({incorrect, pinfo, Pinfo})
+            end,
             receive
                 {'DOWN', M, process, P, Reason} ->
                     io:format("~p died with exit reason ~p~n", [P, Reason]),
+                    verify_nc(node()),
+                    verify_nc(Node),
                     normal = Reason
             end
     end.
@@ -720,6 +766,7 @@ link_to_dead_new_node(Config) when is_list(Config) ->
         {'EXIT', Pid, noproc} ->
             ok;
         Other ->
+            stop_node(Node),
             ct:fail({unexpected_message, Other})
     after 5000 ->
               ct:fail(nothing_received)
@@ -931,7 +978,9 @@ dist_auto_connect_never(Config) when is_list(Config) ->
                      ok;
                  {do_dist_auto_connect, Error} ->
                      {error, Error};
-                 Other ->
+                 %% The io:formats in dos_dist_auto_connect will
+                 %% generate port output messages that are ok
+                 Other when not is_port(element(1, Other))->
                      {error, Other}
              after 32000 ->
                        timeout
@@ -1107,23 +1156,6 @@ atom_roundtrip(Config) when is_list(Config) ->
     stop_node(Node),
     ok.
 
-atom_roundtrip_r16b(Config) when is_list(Config) ->
-    case test_server:is_release_available("r16b") of
-        true ->
-            ct:timetrap({minutes, 6}),
-            AtomData = unicode_atom_data(),
-            verify_atom_data(AtomData),
-            case start_node(Config, [], "r16b") of
-                {ok, Node} ->
-                    do_atom_roundtrip(Node, AtomData),
-                    stop_node(Node);
-                {error, timeout} ->
-                    {skip,"Unable to start OTP R16B release"}
-            end;
-        false ->
-            {skip,"No OTP R16B available"}
-    end.
-
 unicode_atom_roundtrip(Config) when is_list(Config) ->
     AtomData = unicode_atom_data(),
     verify_atom_data(AtomData),
@@ -1364,6 +1396,303 @@ get_conflicting_unicode_atoms(CIX, N) ->
             get_conflicting_unicode_atoms(CIX, N)
     end.
 
+
+%% The message_latency_large tests that small distribution messages are
+%% not blocked by other large distribution messages. Basically it tests
+%% that fragmentation of distribution messages works.
+%%
+%% Because of large problems to get reliable values from these testcases
+%% they no longer fail when the latency is incorrect. However, they are
+%% kept as they continue to find bugs in the distribution implementation.
+message_latency_large_message(Config) when is_list(Config) ->
+    measure_latency_large_message(?FUNCTION_NAME, fun(Dropper, Payload) -> Dropper ! Payload end).
+
+message_latency_large_exit2(Config) when is_list(Config) ->
+    measure_latency_large_message(?FUNCTION_NAME, fun erlang:exit/2).
+
+message_latency_large_link_exit(Config) when is_list(Config) ->
+    message_latency_large_exit(?FUNCTION_NAME, fun erlang:link/1).
+
+message_latency_large_monitor_exit(Config) when is_list(Config) ->
+    message_latency_large_exit(?FUNCTION_NAME, fun(Dropper) ->
+                                                       Dropper ! {monitor, self()},
+                                                       receive ok -> ok end
+                                               end).
+
+message_latency_large_exit(Nodename, ReasonFun) ->
+    measure_latency_large_message(
+      Nodename,
+      fun(Dropper, Payload) ->
+              Pid  = spawn(fun() ->
+                                   receive go -> ok end,
+                                   ReasonFun(Dropper),
+                                   exit(Payload)
+                           end),
+
+              FlushTrace = fun F() ->
+                                   receive
+                                       {trace, Pid, _, _} ->
+                                           F()
+                                   after 0 ->
+                                           ok
+                                   end
+                           end,
+
+              erlang:trace(Pid, true, [exiting]),
+              Pid ! go,
+              receive
+                  {trace, Pid, out_exited, 0} ->
+                      FlushTrace()
+              end
+      end).
+
+measure_latency_large_message(Nodename, DataFun) ->
+
+    erlang:system_monitor(self(), [busy_dist_port]),
+
+    {ok, N} = start_node(Nodename),
+
+    Dropper = spawn(N, fun F() ->
+                               process_flag(trap_exit, true),
+                               receive
+                                   {monitor,Pid} ->
+                                       erlang:monitor(process, Pid),
+                                       Pid ! ok;
+                                   _ -> ok
+                               end,
+                               F()
+                       end),
+
+    Echo = spawn(N, fun F() -> receive {From, Msg} -> From ! Msg, F() end end),
+
+    BuildType = erlang:system_info(build_type),
+    WordSize = erlang:system_info(wordsize),
+
+    if
+        BuildType =/= opt; WordSize =:= 4 ->
+            %% Test 3.2 MB and 32 MB and test the latency difference of sent messages
+            Payloads = [{I, <<0:(I * 32 * 1024 * 8)>>} || I <- [1,10]];
+        true ->
+            %% Test 32 MB and 320 MB and test the latency difference of sent messages
+            Payloads = [{I, <<0:(I * 32 * 1024 * 1024 * 8)>>} || I <- [1,10]]
+    end,
+
+    IndexTimes = [{I, measure_latency(DataFun, Dropper, Echo, P)}
+                  || {I, P} <- Payloads],
+
+    Times = [ Time || {_I, Time} <- IndexTimes],
+
+    ct:pal("~p",[IndexTimes]),
+
+    stop_node(N),
+
+    case {lists:max(Times), lists:min(Times)} of
+        {Max, Min} when Max * 0.25 > Min, BuildType =:= opt ->
+            %% We only issue a comment for this failure as the
+            %% testcases proved very difficult to run successfully
+            %% on many platforms.
+            ct:comment({incorrect_latency, IndexTimes}),
+            ok;
+        _ ->
+            ok
+    end.
+
+measure_latency(DataFun, Dropper, Echo, Payload) ->
+
+    flush(),
+
+    Senders = [spawn_monitor(
+                 fun F() ->
+                         DataFun(Dropper, Payload),
+                         receive
+                             die -> ok
+                         after 0 ->
+                                 F()
+                         end
+                 end) || _ <- lists:seq(1,2)],
+
+    wait_for_busy_dist(2 * 60 * 1000, 10),
+
+    {TS, Times} =
+        timer:tc(fun() ->
+                         [begin
+                              T0 = erlang:monotonic_time(),
+                              Echo ! {self(), hello},
+                              receive hello -> ok end,
+                              (erlang:monotonic_time() - T0) / 1000000
+                          end || _ <- lists:seq(1,100)]
+                 end),
+    Avg = lists:sum(Times) / length(Times),
+    StdDev = math:sqrt(lists:sum([math:pow(V - Avg,2) || V <- Times]) / length(Times)),
+    ct:pal("Times: Avg: ~p Max: ~p Min: ~p Var: ~p",
+           [Avg, lists:max(Times), lists:min(Times), StdDev]),
+    [begin
+         Sender ! die,
+         receive
+             {'DOWN', Ref, process, _, _} ->
+                 ok
+         end
+     end || {Sender, Ref} <- Senders],
+    TS.
+
+wait_for_busy_dist(_Tmo, 0) ->
+    ok;
+wait_for_busy_dist(Tmo, N) ->
+    T0 = erlang:monotonic_time(millisecond),
+    receive
+         {monitor, _Sender, busy_dist_port, _Info} ->
+             wait_for_busy_dist(Tmo - (erlang:monotonic_time(millisecond) - T0), N - 1)
+    after Tmo ->
+            ct:log("Timed out waiting for busy_dist, ~p left",[N]),
+            timeout
+    end.
+
+flush() ->
+    receive
+        _ ->
+            flush()
+    after 0 ->
+            ok
+    end.
+
+system_limit(Config) when is_list(Config) ->
+    case erlang:system_info(wordsize) of
+        8 ->
+            case proplists:get_value(system_total_memory,
+                                     memsup:get_system_memory_data()) of
+                Memory when is_integer(Memory),
+                            Memory > 6*1024*1024*1024 ->
+                    test_system_limit(Config),
+                    garbage_collect(),
+                    ok;
+                _ ->
+                    {skipped, "Not enough memory on this machine"}
+            end;
+        4 ->
+            {skipped, "Only interesting on 64-bit builds"}
+    end.
+
+test_system_limit(Config) when is_list(Config) ->
+    Bits = ((1 bsl 32)+1)*8,
+    HugeBin = <<0:Bits>>,
+    HugeListBin = [lists:duplicate(2000000,2000000), HugeBin],
+    {ok, N1} = start_node(Config),
+    monitor_node(N1, true),
+    receive
+        {nodedown, N1} ->
+            ct:fail({unexpected_nodedown, N1})
+    after 0 ->
+            ok
+    end,
+    P1 = spawn(N1,
+               fun () ->
+                       receive after infinity -> ok end
+               end),
+
+    io:format("~n** distributed send **~n~n", []),
+    try
+        P1 ! HugeBin,
+        exit(oops1)
+    catch
+        error:system_limit -> ok
+    end,
+    try
+        P1 ! HugeListBin,
+        exit(oops2)
+    catch
+        error:system_limit -> ok
+    end,
+
+    io:format("~n** distributed exit **~n~n", []),
+    try
+        exit(P1, HugeBin),
+        exit(oops3)
+    catch
+        error:system_limit -> ok
+    end,
+    try
+        exit(P1, HugeListBin),
+        exit(oops4)
+    catch
+        error:system_limit -> ok
+    end,
+
+    io:format("~n** distributed registered send **~n~n", []),
+    try
+        {missing_proc, N1} ! HugeBin,
+        exit(oops5)
+    catch
+        error:system_limit -> ok
+    end,
+    try
+        {missing_proc, N1} ! HugeListBin,
+        exit(oops6)
+    catch
+        error:system_limit -> ok
+    end,
+    receive
+        {nodedown, N1} ->
+            ct:fail({unexpected_nodedown, N1})
+    after 0 ->
+            ok
+    end,
+
+    %%
+    %% system_limit in exit reasons brings the
+    %% connection down...
+    %%
+
+    io:format("~n** distributed link exit **~n~n", []),
+    spawn(fun () ->
+                  link(P1),
+                  exit(HugeBin)
+          end),
+    receive {nodedown, N1} -> ok end,
+
+    {ok, N2} = start_node(Config),
+    monitor_node(N2, true),
+    P2 = spawn(N2,
+               fun () ->
+                       receive after infinity -> ok end
+               end),
+    spawn(fun () ->
+                  link(P2),
+                  exit(HugeListBin)
+          end),
+    receive {nodedown, N2} -> ok end,
+
+    io:format("~n** distributed monitor down **~n~n", []),
+    {ok, N3} = start_node(Config),
+    monitor_node(N3, true),
+    Go1 = make_ref(),
+    LP1 = spawn(fun () ->
+                        receive Go1 -> ok end,
+                        exit(HugeBin)
+                end),
+    _ = spawn(N3,
+               fun () ->
+                       _ = erlang:monitor(process, LP1),
+                       LP1 ! Go1,
+                       receive after infinity -> ok end
+               end),
+    receive {nodedown, N3} -> ok end,
+
+    {ok, N4} = start_node(Config),
+    monitor_node(N4, true),
+    Go2 = make_ref(),
+    LP2 = spawn(fun () ->
+                        receive Go2 -> ok end,
+                        exit(HugeListBin)
+                end),
+    _ = spawn(N4,
+              fun () ->
+                      _ = erlang:monitor(process, LP2),
+                      LP2 ! Go2,
+                      receive after infinity -> ok end
+              end),
+    receive {nodedown, N4} -> ok end,
+    ok.
+
 -define(COOKIE, '').
 -define(DOP_LINK,		1).
 -define(DOP_SEND,		2).
@@ -1382,6 +1711,15 @@ get_conflicting_unicode_atoms(CIX, N) ->
 -define(DOP_DEMONITOR_P,	20).
 -define(DOP_MONITOR_P_EXIT,	21).
 
+-define(DOP_SEND_SENDER, 22).
+-define(DOP_SEND_SENDER_TT, 23).
+
+-define(DOP_PAYLOAD_EXIT, 24).
+-define(DOP_PAYLOAD_EXIT_TT, 25).
+-define(DOP_PAYLOAD_EXIT2, 26).
+-define(DOP_PAYLOAD_EXIT2_TT, 27).
+-define(DOP_PAYLOAD_MONITOR_P_EXIT, 28).
+
 start_monitor(Offender,P) ->
     Parent = self(),
     Q = spawn(Offender,
@@ -1515,7 +1853,145 @@ bad_dist_structure(Config) when is_list(Config) ->
     stop_node(Victim),
     ok.
 
+%% Test various dist fragmentation errors
+bad_dist_fragments(Config) when is_list(Config) ->
+    ct:timetrap({seconds, 15}),
+
+    {ok, Offender} = start_node(bad_dist_fragment_offender),
+    {ok, Victim} = start_node(bad_dist_fragment_victim),
+
+    Msg = iolist_to_binary(dmsg_ext(lists:duplicate(255,255))),
+
+    start_node_monitors([Offender,Victim]),
+    Parent = self(),
+    P = spawn(Victim,
+              fun () ->
+                      process_flag(trap_exit,true),
+                      Parent ! {self(), started},
+                      receive check_msgs -> ok end,
+                      bad_dist_struct_check_msgs([one,
+                                                  two]),
+                      Parent ! {self(), messages_checked},
+                      receive done -> ok end
+              end),
+    receive {P, started} -> ok end,
+    pong = rpc:call(Victim, net_adm, ping, [Offender]),
+    verify_up(Offender, Victim),
+    true = lists:member(Offender, rpc:call(Victim, erlang, nodes, [])),
+    start_monitor(Offender,P),
+    P ! one,
+
+    start_monitor(Offender,P),
+    send_bad_fragments(Offender, Victim, P,{?DOP_SEND,?COOKIE,P},3,
+                      [{frg, 1, binary:part(Msg, 10,byte_size(Msg)-10)}]),
+
+    start_monitor(Offender,P),
+    send_bad_fragments(Offender, Victim, P,{?DOP_SEND,?COOKIE,P},3,
+                      [{hdr, 3, binary:part(Msg, 0,10)},
+                       {frg, 1, binary:part(Msg, 10,byte_size(Msg)-10)}]),
+
+    start_monitor(Offender,P),
+    send_bad_fragments(Offender, Victim, P,{?DOP_SEND,?COOKIE,P},3,
+                      [{hdr, 3, binary:part(Msg, 0,10)},
+                       {hdr, 3, binary:part(Msg, 0,10)}]),
+
+    start_monitor(Offender,P),
+    send_bad_fragments(Offender, Victim, P,{?DOP_SEND,?COOKIE,P,broken},3,
+                      [{hdr, 1, binary:part(Msg, 10,byte_size(Msg)-10)}]),
+
+    start_monitor(Offender,P),
+    send_bad_fragments(Offender, Victim, P,{?DOP_SEND,?COOKIE,P},3,
+                      [{hdr, 3, binary:part(Msg, 10,byte_size(Msg)-10)},
+                       close]),
+
+    start_monitor(Offender,P),
+    ExitVictim = spawn(Victim, fun() -> receive ok -> ok end end),
+    send_bad_fragments(Offender, Victim, P,{?DOP_PAYLOAD_EXIT,P,ExitVictim},2,
+                      [{hdr, 1, [131]}]),
+
+    start_monitor(Offender,P),
+    Exit2Victim = spawn(Victim, fun() -> receive ok -> ok end end),
+    send_bad_fragments(Offender, Victim, P,{?DOP_PAYLOAD_EXIT2,P,Exit2Victim},2,
+                      [{hdr, 1, [132]}]),
+
+    start_monitor(Offender,P),
+    DownVictim = spawn(Victim, fun() -> receive ok -> ok end end),
+    DownRef = erlang:monitor(process, DownVictim),
+    send_bad_fragments(Offender, Victim, P,{?DOP_PAYLOAD_MONITOR_P_EXIT,P,DownVictim,DownRef},2,
+                      [{hdr, 1, [133]}]),
+
+    P ! two,
+    P ! check_msgs,
+    receive
+        {P, messages_checked} -> ok
+    after 5000 ->
+              exit(victim_is_dead)
+    end,
+
+    {message_queue_len, 0}
+    = rpc:call(Victim, erlang, process_info, [P, message_queue_len]),
+
+    unlink(P),
+    P ! done,
+    stop_node(Offender),
+    stop_node(Victim),
+    ok.
+
+dmsg_frag_hdr(Frag) ->
+    dmsg_frag_hdr(erlang:phash2(self()), Frag).
+dmsg_frag_hdr(Seq, Frag) ->
+    [131, $E, uint64_be(Seq), uint64_be(Frag), 0].
+
+dmsg_frag(Frag) ->
+    dmsg_frag(erlang:phash2(self()), Frag).
+dmsg_frag(Seq, Frag) ->
+    [131, $F, uint64_be(Seq), uint64_be(Frag)].
 
+send_bad_fragments(Offender,VictimNode,Victim,Ctrl,WhereToPutSelf,Fragments) ->
+    Parent = self(),
+    Done = make_ref(),
+    ct:pal("Send: ~p",[Fragments]),
+    spawn_link(Offender,
+          fun () ->
+                  Node = node(Victim),
+                  pong = net_adm:ping(Node),
+                  erlang:monitor_node(Node, true),
+                  DCtrl = dctrl(Node),
+                  Ctrl1 = case WhereToPutSelf of
+                             0 ->
+                                 Ctrl;
+                             N when N > 0 ->
+                                 setelement(N,Ctrl,self())
+                         end,
+
+                  FragData = [case Type of
+                                  hdr ->
+                                      [dmsg_frag_hdr(FragId),
+                                       dmsg_ext(Ctrl1), FragPayload];
+                                  frg ->
+                                      [dmsg_frag(FragId), FragPayload]
+                              end || {Type, FragId, FragPayload} <- Fragments],
+
+                  receive {nodedown, Node} -> exit("premature nodedown")
+                  after 10 -> ok
+                  end,
+
+                  [ dctrl_send(DCtrl, D) || D <- FragData ],
+                  [ erlang:port_close(DCtrl) || close <- Fragments],
+
+                  receive {nodedown, Node} -> ok
+                  after 5000 -> exit("missing nodedown")
+                  end,
+                  Parent ! {FragData,Done}
+          end),
+    receive
+        {WhatSent,Done} ->
+            io:format("Offender sent ~p~n",[WhatSent]),
+            verify_nc(VictimNode),
+            ok
+    after 7000 ->
+              exit(unable_to_send)
+    end.
 
 bad_dist_ext_receive(Config) when is_list(Config) ->
     {ok, Offender} = start_node(bad_dist_ext_receive_offender),
@@ -2124,8 +2600,30 @@ start_node(Config, Args, Rel) when is_list(Config), is_list(Rel) ->
     start_node(Name, Args, Rel).
 
 stop_node(Node) ->
+    verify_nc(Node),
     test_server:stop_node(Node).
 
+verify_nc(Node) ->
+    P = self(),
+    Ref = make_ref(),
+    Pid = spawn(Node,
+                fun() ->
+                        R = erts_test_utils:check_node_dist(fun(E) -> E end),
+                        P ! {Ref, R}
+                end),
+    MonRef = monitor(process, Pid),
+    receive
+        {Ref, ok} ->
+            demonitor(MonRef,[flush]),
+            ok;
+        {Ref, Error} ->
+            ct:log("~s",[Error]),
+            ct:fail(failed_nc_refc_check);
+        {'DOWN', MonRef, _, _, _} = Down ->
+            ct:log("~p",[Down]),
+            ct:fail(crashed_nc_refc_check)
+    end.
+
 freeze_node(Node, MS) ->
     Own = 300,
     DoingIt = make_ref(),
@@ -2485,6 +2983,17 @@ mk_ref({NodeNameExt, Creation}, Numbers) when is_integer(Creation),
             exit({unexpected_binary_to_term_result, Other})
     end.
 
+uint64_be(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 64 ->
+    [(Uint bsr 56) band 16#ff,
+     (Uint bsr 48) band 16#ff,
+     (Uint bsr 40) band 16#ff,
+     (Uint bsr 32) band 16#ff,
+     (Uint bsr 24) band 16#ff,
+     (Uint bsr 16) band 16#ff,
+     (Uint bsr 8) band 16#ff,
+     Uint band 16#ff];
+uint64_be(Uint) ->
+    exit({badarg, uint64_be, [Uint]}).
 
 uint32_be(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 32 ->
     [(Uint bsr 24) band 16#ff,
@@ -2505,3 +3014,23 @@ uint8(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 8 ->
     Uint band 16#ff;
 uint8(Uint) ->
     exit({badarg, uint8, [Uint]}).
+
+free_memory() ->
+    %% Free memory in MB.
+    try
+	SMD = memsup:get_system_memory_data(),
+	{value, {free_memory, Free}} = lists:keysearch(free_memory, 1, SMD),
+	TotFree = (Free +
+		   case lists:keysearch(cached_memory, 1, SMD) of
+		       {value, {cached_memory, Cached}} -> Cached;
+		       false -> 0
+		   end +
+		   case lists:keysearch(buffered_memory, 1, SMD) of
+		       {value, {buffered_memory, Buffed}} -> Buffed;
+		       false -> 0
+		   end),
+	TotFree div (1024*1024)
+    catch
+	error : undef ->
+	    ct:fail({"os_mon not built"})
+    end.
diff --git a/erts/emulator/test/driver_SUITE.erl b/erts/emulator/test/driver_SUITE.erl
index bd62708aa7..f6d7c55017 100644
--- a/erts/emulator/test/driver_SUITE.erl
+++ b/erts/emulator/test/driver_SUITE.erl
@@ -120,29 +120,6 @@
 
 -define(heap_binary_size, 64).
 
-init_per_testcase(Case, Config) when is_atom(Case), is_list(Config) ->
-    CIOD = rpc(Config,
-               fun() ->
-                       case catch erts_debug:get_internal_state(available_internal_state) of
-                           true -> ok;
-                           _ -> erts_debug:set_internal_state(available_internal_state, true)
-                       end,
-                       erts_debug:get_internal_state(check_io_debug)
-               end),
-    erlang:display({init_per_testcase, Case}),
-    0 = element(1, CIOD),
-    [{testcase, Case}|Config].
-
-end_per_testcase(Case, Config) ->
-    erlang:display({end_per_testcase, Case}),
-    CIOD = rpc(Config,
-               fun() ->
-                       get_stable_check_io_info(),
-                       erts_debug:get_internal_state(check_io_debug)
-               end),
-    0 = element(1, CIOD),
-    ok.
-
 suite() ->
     [{ct_hooks,[ts_install_cth]},
      {timetrap, {minutes, 1}}].
@@ -219,6 +196,48 @@ end_per_group(_GroupName, Config) ->
     end,
     Config.
 
+init_per_testcase(Case, Config) when is_atom(Case), is_list(Config) ->
+    CIOD = rpc(Config,
+               fun() ->
+                       case catch erts_debug:get_internal_state(available_internal_state) of
+                           true -> ok;
+                           _ -> erts_debug:set_internal_state(available_internal_state, true)
+                       end,
+                       erts_debug:get_internal_state(check_io_debug)
+               end),
+    erlang:display({init_per_testcase, Case}),
+    0 = element(1, CIOD),
+    [{testcase, Case}|Config].
+
+end_per_testcase(Case, Config) ->
+    erlang:display({end_per_testcase, Case}),
+    try rpc(Config, fun() ->
+                            get_stable_check_io_info(),
+                            erts_debug:get_internal_state(check_io_debug)
+                    end) of
+        CIOD ->
+            0 = element(1, CIOD)
+    catch _E:_R:_ST ->
+            %% Logs some info about the system
+            ct_os_cmd("epmd -names"),
+            ct_os_cmd("ps aux"),
+            %% Restart the node
+            case proplists:get_value(node, Config) of
+                undefined ->
+                    ok;
+                Node ->
+                    timer:sleep(1000), %% Give the node time to die
+                    [NodeName, _] = string:lexemes(atom_to_list(Node),"@"),
+                    {ok, Node} = start_node_final(
+                                   list_to_atom(NodeName),
+                                   proplists:get_value(node_args, Config))
+            end
+    end,
+    ok.
+
+ct_os_cmd(Cmd) ->
+    ct:log("~s: ~s",[Cmd,os:cmd(Cmd)]).
+
 %% Test sending bad types to port with an outputv-capable driver.
 outputv_errors(Config) when is_list(Config) ->
     Path = proplists:get_value(data_dir, Config),
@@ -998,7 +1017,9 @@ chkio_test({erts_poll_info, Before},
             During = get_check_io_total(erlang:system_info(check_io)),
             erlang:display(During),
 
-            0 = element(1, erts_debug:get_internal_state(check_io_debug)),
+            [0 = element(1, erts_debug:get_internal_state(check_io_debug)) ||
+                %% The pollset is not stable when running the fallback testcase
+                Test /= ?CHKIO_USE_FALLBACK_POLLSET],
             io:format("During test: ~p~n", [During]),
             chk_chkio_port(Port),
             case erlang:port_control(Port, ?CHKIO_STOP, "") of
@@ -1069,14 +1090,19 @@ get_stable_check_io_info(N) ->
 get_check_io_total(ChkIo) ->
     ct:log("ChkIo = ~p~n",[ChkIo]),
     {Fallback, Rest} = get_fallback(ChkIo),
+    OnlyPollThreads = [PS || PS <- Rest, not is_scheduler_pollset(PS)],
     add_fallback_infos(Fallback,
-      lists:foldl(fun(Pollset, Acc) ->
-                          lists:zipwith(fun(A, B) ->
-                                                add_pollset_infos(A,B)
-                                        end,
-                                        Pollset, Acc)
-                  end,
-                  hd(Rest), tl(Rest))).
+      lists:foldl(
+        fun(Pollset, Acc) ->
+                lists:zipwith(fun(A, B) ->
+                                      add_pollset_infos(A,B)
+                              end,
+                              Pollset, Acc)
+        end,
+        hd(OnlyPollThreads), tl(OnlyPollThreads))).
+
+is_scheduler_pollset(Pollset) ->
+    proplists:get_value(poll_threads, Pollset) == 0.
 
 add_pollset_infos({Tag, A}=TA , {Tag, B}=TB) ->
     case tag_type(Tag) of
@@ -2637,7 +2663,6 @@ start_node(Config) when is_list(Config) ->
 start_node(Name) ->
     start_node(Name, "").
 start_node(NodeName, Args) ->
-    Pa = filename:dirname(code:which(?MODULE)),
     Name = list_to_atom(atom_to_list(?MODULE)
                         ++ "-"
                         ++ atom_to_list(NodeName)
@@ -2645,7 +2670,17 @@ start_node(NodeName, Args) ->
                         ++ integer_to_list(erlang:system_time(second))
                         ++ "-"
                         ++ integer_to_list(erlang:unique_integer([positive]))),
-    test_server:start_node(Name, slave, [{args, Args ++ " -pa "++Pa}]).
+    start_node_final(Name, Args).
+start_node_final(Name, Args) ->
+    {ok, Pwd} = file:get_cwd(),
+    FinalArgs = [Args, " -pa ", filename:dirname(code:which(?MODULE))],
+    {ok, Node} = test_server:start_node(Name, slave, [{args, FinalArgs}]),
+    LogPath = Pwd ++ "/error_log." ++ atom_to_list(Name),
+    ct:pal("Logging to: ~s", [LogPath]),
+    rpc:call(Node, logger, add_handler, [file_handler, logger_std_h,
+                                         #{formatter => {logger_formatter,#{ single_line => false }},
+                                           config => #{file => LogPath }}]),
+    {ok, Node}.
 
 stop_node(Node) ->
     test_server:stop_node(Node).
@@ -2660,24 +2695,7 @@ wait_deallocations() ->
 
 driver_alloc_size() ->
     wait_deallocations(),
-    case erlang:system_info({allocator_sizes, driver_alloc}) of
-        false ->
-            undefined;
-        MemInfo ->
-            CS = lists:foldl(
-                   fun ({instance, _, L}, Acc) ->
-                           {value,{_,MBCS}} = lists:keysearch(mbcs, 1, L),
-                           {value,{_,SBCS}} = lists:keysearch(sbcs, 1, L),
-                           [MBCS,SBCS | Acc]
-                   end,
-                   [],
-                   MemInfo),
-            lists:foldl(
-              fun(L, Sz0) ->
-                      {value,{_,Sz,_,_}} = lists:keysearch(blocks_size, 1, L),
-                      Sz0+Sz
-              end, 0, CS)
-    end.
+    erts_debug:alloc_blocks_size(driver_alloc).
 
 rpc(Config, Fun) ->
     case proplists:get_value(node, Config) of
diff --git a/erts/emulator/test/dump_SUITE.erl b/erts/emulator/test/dump_SUITE.erl
index d0237b78cc..6133b82756 100644
--- a/erts/emulator/test/dump_SUITE.erl
+++ b/erts/emulator/test/dump_SUITE.erl
@@ -24,7 +24,7 @@
 
 -export([all/0, suite/0, init_per_testcase/2, end_per_testcase/2]).
 
--export([signal_abort/1]).
+-export([signal_abort/1, exiting_dump/1, free_dump/1]).
 
 -export([load/0]).
 
@@ -35,7 +35,7 @@ suite() ->
      {timetrap, {minutes, 2}}].
 
 all() ->
-    [signal_abort].
+    [signal_abort, exiting_dump, free_dump].
 
 init_per_testcase(signal_abort, Config) ->
     SO = erlang:system_info(schedulers_online),
@@ -48,7 +48,10 @@ init_per_testcase(signal_abort, Config) ->
             {skip, "the platform does not support scheduler dump"};
        Dump ->
             Config
-    end.
+    end;
+init_per_testcase(_, Config) ->
+    Config.
+
 
 end_per_testcase(_, Config) ->
     Config.
@@ -65,12 +68,14 @@ signal_abort(Config) ->
 
     {ok, Node} = start_node(Config),
 
-    _P1 = spawn(Node, ?MODULE, load, []),
-    _P2 = spawn(Node, ?MODULE, load, []),
-    _P3 = spawn(Node, ?MODULE, load, []),
-    _P4 = spawn(Node, ?MODULE, load, []),
-    _P5 = spawn(Node, ?MODULE, load, []),
-    _P6 = spawn(Node, ?MODULE, load, []),
+    SO = rpc:call(Node, erlang, system_info, [schedulers_online]),
+
+    _P1 = spawn_opt(Node, ?MODULE, load, [], [{scheduler, (0 rem SO) + 1}]),
+    _P2 = spawn_opt(Node, ?MODULE, load, [], [{scheduler, (1 rem SO) + 1}]),
+    _P3 = spawn_opt(Node, ?MODULE, load, [], [{scheduler, (2 rem SO) + 1}]),
+    _P4 = spawn_opt(Node, ?MODULE, load, [], [{scheduler, (3 rem SO) + 1}]),
+    _P5 = spawn_opt(Node, ?MODULE, load, [], [{scheduler, (4 rem SO) + 1}]),
+    _P6 = spawn_opt(Node, ?MODULE, load, [], [{scheduler, (5 rem SO) + 1}]),
 
     timer:sleep(500),
 
@@ -79,8 +84,6 @@ signal_abort(Config) ->
 
     {ok, Bin} = get_dump_when_done(Dump),
 
-    ct:log("~s",[Bin]),
-
     {match, Matches} = re:run(Bin,"Current Process: <",[global]),
 
     ct:log("Found ~p",[Matches]),
@@ -91,6 +94,111 @@ signal_abort(Config) ->
 
     ok.
 
+load() ->
+    lists:seq(1,10000),
+    load().
+
+
+%% Test that crash dumping when a process is in the state EXITING works
+exiting_dump(Config) when is_list(Config) ->
+    Dump = filename:join(proplists:get_value(priv_dir, Config),"signal_abort.dump"),
+
+    {ok, Node} = start_node(Config),
+
+    Self = self(),
+
+    Pid = spawn_link(Node,
+                     fun() ->
+                             [begin
+                                  T = ets:new(hej,[]),
+                                  [ets:insert(T,{I,I}) || I <- lists:seq(1,1000)]
+                              end || _ <- lists:seq(1,1000)],
+                             Self ! ready,
+                             receive ok -> ok end
+                     end),
+
+    true = rpc:call(Node, os, putenv, ["ERL_CRASH_DUMP",Dump]),
+
+    receive ready -> unlink(Pid), Pid ! ok end,
+
+    rpc:call(Node, erlang, halt, ["dump"]),
+
+    {ok, Bin} = get_dump_when_done(Dump),
+
+    {match, Matches} = re:run(Bin,"^State: Exiting", [global, multiline]),
+
+    ct:log("Found ~p",[Matches]),
+
+    true = length(Matches) == 1,
+
+    file:delete(Dump),
+
+    ok.
+
+%% Test that crash dumping when a process is in the state FREE works
+free_dump(Config) when is_list(Config) ->
+    Dump = filename:join(proplists:get_value(priv_dir, Config),"signal_abort.dump"),
+
+    {ok, NodeA} = start_node(Config),
+    {ok, NodeB} = start_node(Config),
+
+    Self = self(),
+
+    PidA = spawn_link(
+             NodeA,
+             fun() ->
+                     Self ! ready,
+                     Reason = lists:duplicate(1000000,100),
+                     receive
+                         ok ->
+                             spawn(fun() ->
+                                           erlang:system_monitor(self(), [busy_dist_port]),
+                                           timer:sleep(5),
+                                           receive
+                                               M ->
+                                                   io:format("~p",[M])
+%% We may want to add this timeout here in-case no busy condition is triggered
+%%                                           after 60 * 1000 ->
+%%                                                   io:format("Timeout")
+                                           end,
+                                           erlang:halt("dump")
+                                   end),
+                             exit(Reason)
+                     end
+             end),
+
+    PidB = spawn_link(NodeB,
+                      fun() ->
+                              [erlang:monitor(process, PidA) || _ <- lists:seq(1,10000)],
+                              Self ! done,
+                              receive _ -> ok end
+                      end),
+
+    receive done -> ok end,
+    true = rpc:call(NodeA, os, putenv, ["ERL_CRASH_DUMP",Dump]),
+    %% Make the node busy towards NodeB for 10 seconds.
+    BusyPid = rpc:call(NodeA, distribution_SUITE, make_busy, [NodeB,10000]),
+    ct:pal("~p",[BusyPid]),
+
+    receive ready -> unlink(PidA), PidA ! ok end,
+
+    {ok, Bin} = get_dump_when_done(Dump),
+
+    {match, Matches} = re:run(Bin,"^State: Non Existing", [global, multiline]),
+
+    ct:log("Found ~p",[Matches]),
+
+    true = length(Matches) == 1,
+
+    file:delete(Dump),
+
+    unlink(PidB),
+
+    rpc:call(NodeB, erlang, halt, [0]),
+
+    ok.
+
+
 get_dump_when_done(Dump) ->
     case file:read_file_info(Dump) of
         {ok, #file_info{ size = Sz }} ->
@@ -104,15 +212,13 @@ get_dump_when_done(Dump, Sz) ->
     timer:sleep(1000),
     case file:read_file_info(Dump) of
         {ok, #file_info{ size = Sz }} ->
-            file:read_file(Dump);
+            {ok, Bin} = file:read_file(Dump),
+            ct:log("~s",[Bin]),
+            {ok, Bin};
         {ok, #file_info{ size = NewSz }} ->
             get_dump_when_done(Dump, NewSz)
     end.
 
-load() ->
-    lists:seq(1,10000),
-    load().
-
 start_node(Config) when is_list(Config) ->
     Pa = filename:dirname(code:which(?MODULE)),
     Name = list_to_atom(atom_to_list(?MODULE)
diff --git a/erts/emulator/test/efile_SUITE.erl b/erts/emulator/test/efile_SUITE.erl
index 7dcf302742..045b351e02 100644
--- a/erts/emulator/test/efile_SUITE.erl
+++ b/erts/emulator/test/efile_SUITE.erl
@@ -45,7 +45,12 @@ iter_max_files(Config) when is_list(Config) ->
 iter_max_files_1(Config) ->
     DataDir = proplists:get_value(data_dir,Config),
     TestFile = filename:join(DataDir, "existing_file"),
-    N = 10,
+    case erlang:system_info(debug_compiled) of
+        true ->
+            N = 5;
+        false ->
+            N = 10
+    end,
     %% Run on a different node in order to make the test more stable.
     Dir = filename:dirname(code:which(?MODULE)),
     {ok,Node} = test_server:start_node(test_iter_max_files,slave,
@@ -100,34 +105,27 @@ open_files(Name) ->
 %% a /proc directory), let's read some zero sized files 500 times each, while
 %% ensuring that response isn't empty << >>
 proc_zero_sized_files(Config) when is_list(Config) ->
-    {Type, Flavor} = os:type(),
-    %% Some files which exist on Linux but might be missing on other systems
-    Inputs = ["/proc/cpuinfo",
-              "/proc/meminfo",
-              "/proc/partitions",
-              "/proc/swaps",
-              "/proc/version",
-              "/proc/uptime",
-              %% curproc is present on freebsd
-              "/proc/curproc/cmdline"],
-    case filelib:is_dir("/proc") of
-        false -> {skip, "/proc not found"}; % skip the test if no /proc
-        _ when Type =:= unix andalso Flavor =:= sunos ->
-            %% SunOS has a /proc, but no zero sized special files
-            {skip, "sunos does not have any zero sized special files"};
-        true ->
-            %% Take away files which do not exist in proc
-            Inputs1 = lists:filter(fun filelib:is_file/1, Inputs),
-
-            %% Fail if none of mentioned files exist in /proc, did we just get
-            %% a normal /proc directory without any special files?
-            ?assertNotEqual([], Inputs1),
-
+    TestFiles0 = [%% Some files which exist on Linux but might be missing on
+                  %% other systems
+                  "/proc/cpuinfo",
+                  "/proc/meminfo",
+                  "/proc/partitions",
+                  "/proc/swaps",
+                  "/proc/version",
+                  "/proc/uptime",
+                  %% curproc is present on FreeBSD
+                  "/proc/curproc/cmdline"],
+
+    TestFiles = [F || F <- TestFiles0, filelib:is_file(F)],
+
+    case TestFiles of
+        [_|_] ->
             %% For 6 inputs and 500 attempts each this do run anywhere
             %% between 500 and 3000 function calls.
-            lists:foreach(
-                fun(Filename) -> do_proc_zero_sized(Filename, 500) end,
-                Inputs1)
+            [do_proc_zero_sized(F, 500) || F <- TestFiles],
+            ok;
+        [] ->
+            {skip, "Failed to find any known zero-sized files"}
     end.
 
 %% @doc Test one file N times to also trigger possible leaking fds and memory
diff --git a/erts/emulator/test/emulator_bench.spec b/erts/emulator/test/emulator_bench.spec
index f709d913b7..03638bfa23 100644
--- a/erts/emulator/test/emulator_bench.spec
+++ b/erts/emulator/test/emulator_bench.spec
@@ -1 +1,3 @@
 {groups,"../emulator_test",estone_SUITE,[estone_bench]}.
+{groups,"../emulator_test",binary_SUITE,[iolist_size_benchmarks]}.
+{groups,"../emulator_test",erts_debug_SUITE,[interpreter_size_bench]}.
diff --git a/erts/emulator/test/erts_debug_SUITE.erl b/erts/emulator/test/erts_debug_SUITE.erl
index 6aa7a445b5..6798e3bf25 100644
--- a/erts/emulator/test/erts_debug_SUITE.erl
+++ b/erts/emulator/test/erts_debug_SUITE.erl
@@ -20,10 +20,14 @@
 
 -module(erts_debug_SUITE).
 -include_lib("common_test/include/ct.hrl").
+-include_lib("common_test/include/ct_event.hrl").
 
--export([all/0, suite/0,
-	 test_size/1,flat_size_big/1,df/1,term_type/1,
-	 instructions/1, stack_check/1]).
+-export([all/0, suite/0, groups/0,
+         test_size/1,flat_size_big/1,df/1,term_type/1,
+         instructions/1, stack_check/1, alloc_blocks_size/1,
+         interpreter_size_bench/1]).
+
+-export([do_alloc_blocks_size/0]).
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
@@ -31,7 +35,16 @@ suite() ->
 
 all() -> 
     [test_size, flat_size_big, df, instructions, term_type,
-     stack_check].
+     stack_check, alloc_blocks_size].
+
+groups() -> 
+    [{interpreter_size_bench, [], [interpreter_size_bench]}].
+
+interpreter_size_bench(_Config) ->
+    Size = erts_debug:interpreter_size(),
+    ct_event:notify(#event{name=benchmark_data,
+                           data=[{value,Size}]}),
+    {comment,integer_to_list(Size)++" bytes"}.
 
 test_size(Config) when is_list(Config) ->
     ConsCell1 = id([a|b]),
@@ -210,5 +223,28 @@ instructions(Config) when is_list(Config) ->
     _ = [list_to_atom(I) || I <- Is],
     ok.
 
+alloc_blocks_size(Config) when is_list(Config) ->
+    F = fun(Args) ->
+                Node = start_slave(Args),
+                ok = rpc:call(Node, ?MODULE, do_alloc_blocks_size, []),
+                true = test_server:stop_node(Node)
+        end,
+    F("+Meamax"),
+    F("+Meamin"),
+    F(""),
+    ok.
+
+do_alloc_blocks_size() ->
+    _ = erts_debug:alloc_blocks_size(binary_alloc),
+    ok.
+
+start_slave(Args) ->
+    Name = ?MODULE_STRING ++ "_slave",
+    Pa = filename:dirname(code:which(?MODULE)),
+    {ok, Node} = test_server:start_node(list_to_atom(Name),
+                                        slave,
+                                        [{args, "-pa " ++ Pa ++ " " ++ Args}]),
+    Node.
+
 id(I) ->
     I.
diff --git a/erts/emulator/test/erts_test_utils.erl b/erts/emulator/test/erts_test_utils.erl
new file mode 100644
index 0000000000..9c9eaa70ed
--- /dev/null
+++ b/erts/emulator/test/erts_test_utils.erl
@@ -0,0 +1,272 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2002-2018. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(erts_test_utils).
+-compile(r20).
+
+%%
+%% THIS MODULE IS ALSO USED BY *OTHER* APPLICATIONS TEST CODE
+%%
+
+-export([mk_ext_pid/3,
+         mk_ext_port/2,
+         mk_ext_ref/2,
+         available_internal_state/1,
+         check_node_dist/0, check_node_dist/1, check_node_dist/3]).
+
+
+
+-define(VERSION_MAGIC,       131).
+
+-define(ATOM_EXT,            100).
+-define(REFERENCE_EXT,       101).
+-define(PORT_EXT,            102).
+-define(PID_EXT,             103).
+-define(NEW_REFERENCE_EXT,   114).
+-define(NEW_PID_EXT,         $X).
+-define(NEW_PORT_EXT,        $Y).
+-define(NEWER_REFERENCE_EXT, $Z).
+
+uint32_be(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 32 ->
+    [(Uint bsr 24) band 16#ff,
+     (Uint bsr 16) band 16#ff,
+     (Uint bsr 8) band 16#ff,
+     Uint band 16#ff];
+uint32_be(Uint) ->
+    exit({badarg, uint32_be, [Uint]}).
+
+
+uint16_be(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 16 ->
+    [(Uint bsr 8) band 16#ff,
+     Uint band 16#ff];
+uint16_be(Uint) ->
+    exit({badarg, uint16_be, [Uint]}).
+
+uint8(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 8 ->
+    Uint band 16#ff;
+uint8(Uint) ->
+    exit({badarg, uint8, [Uint]}).
+
+pid_tag(bad_creation) -> ?PID_EXT;
+pid_tag(Creation) when Creation =< 3 -> ?PID_EXT;
+pid_tag(_Creation) -> ?NEW_PID_EXT.
+
+enc_creation(bad_creation) -> uint8(4);
+enc_creation(Creation) when Creation =< 3 -> uint8(Creation);
+enc_creation(Creation) -> uint32_be(Creation).
+
+mk_ext_pid({NodeName, Creation}, Number, Serial) when is_atom(NodeName) ->
+    mk_ext_pid({atom_to_list(NodeName), Creation}, Number, Serial);
+mk_ext_pid({NodeName, Creation}, Number, Serial) ->
+    case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
+					      pid_tag(Creation),
+					      ?ATOM_EXT,
+					      uint16_be(length(NodeName)),
+					      NodeName,
+					      uint32_be(Number),
+					      uint32_be(Serial),
+					      enc_creation(Creation)])) of
+	Pid when is_pid(Pid) ->
+	    Pid;
+	{'EXIT', {badarg, _}} ->
+	    exit({badarg, mk_pid, [{NodeName, Creation}, Number, Serial]});
+	Other ->
+	    exit({unexpected_binary_to_term_result, Other})
+    end.
+
+port_tag(bad_creation) -> ?PORT_EXT;
+port_tag(Creation) when Creation =< 3 -> ?PORT_EXT;
+port_tag(_Creation) -> ?NEW_PORT_EXT.
+
+mk_ext_port({NodeName, Creation}, Number) when is_atom(NodeName) ->
+    mk_ext_port({atom_to_list(NodeName), Creation}, Number);
+mk_ext_port({NodeName, Creation}, Number) ->
+    case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
+					      port_tag(Creation),
+					      ?ATOM_EXT,
+					      uint16_be(length(NodeName)),
+					      NodeName,
+					      uint32_be(Number),
+					      enc_creation(Creation)])) of
+	Port when is_port(Port) ->
+	    Port;
+	{'EXIT', {badarg, _}} ->
+	    exit({badarg, mk_port, [{NodeName, Creation}, Number]});
+	Other ->
+	    exit({unexpected_binary_to_term_result, Other})
+    end.
+
+ref_tag(bad_creation) -> ?NEW_REFERENCE_EXT;
+ref_tag(Creation) when Creation =< 3 -> ?NEW_REFERENCE_EXT;
+ref_tag(_Creation) -> ?NEWER_REFERENCE_EXT.
+
+mk_ext_ref({NodeName, Creation}, Numbers) when is_atom(NodeName),
+					   is_list(Numbers) ->
+    mk_ext_ref({atom_to_list(NodeName), Creation}, Numbers);
+mk_ext_ref({NodeName, Creation}, [Number]) when is_list(NodeName),
+                                                Creation =< 3,
+                                                is_integer(Number) ->
+    case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
+                                              ?REFERENCE_EXT,
+                                              ?ATOM_EXT,
+                                              uint16_be(length(NodeName)),
+                                              NodeName,
+                                              uint32_be(Number),
+                                              uint8(Creation)])) of
+        Ref when is_reference(Ref) ->
+            Ref;
+        {'EXIT', {badarg, _}} ->
+            exit({badarg, mk_ref, [{NodeName, Creation}, [Number]]});
+        Other ->
+            exit({unexpected_binary_to_term_result, Other})
+    end;
+mk_ext_ref({NodeName, Creation}, Numbers) when is_list(NodeName),
+                                               is_list(Numbers) ->
+    case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
+					      ref_tag(Creation),
+					      uint16_be(length(Numbers)),
+					      ?ATOM_EXT,
+					      uint16_be(length(NodeName)),
+					      NodeName,
+					      enc_creation(Creation),
+					      lists:map(fun (N) ->
+								uint32_be(N)
+							end,
+							Numbers)])) of
+	Ref when is_reference(Ref) ->
+	    Ref;
+	{'EXIT', {badarg, _}} ->
+	    exit({badarg, mk_ref, [{NodeName, Creation}, Numbers]});
+	Other ->
+	    exit({unexpected_binary_to_term_result, Other})
+    end.
+
+
+available_internal_state(Bool) when Bool == true; Bool == false ->
+    case {Bool,
+          (catch erts_debug:get_internal_state(available_internal_state))} of
+        {true, true} ->
+            true;
+        {false, true} ->
+            erts_debug:set_internal_state(available_internal_state, false),
+            true;
+        {true, _} ->
+            erts_debug:set_internal_state(available_internal_state, true),
+            false;
+        {false, _} ->
+            false
+    end.
+
+
+%%
+%% Check reference counters for node- and dist entries.
+%%
+check_node_dist() ->
+    check_node_dist(fun(ErrMsg) ->
+                            io:format("check_node_dist ERROR:\n~p\n", [ErrMsg]),
+                            error
+                    end).
+
+check_node_dist(Fail) ->
+    AIS = available_internal_state(true),
+    [erlang:garbage_collect(P) || P <- erlang:processes()],
+    {{node_references, NodeRefs},
+     {dist_references, DistRefs}} =
+        erts_debug:get_internal_state(node_and_dist_references),
+    R = check_node_dist(Fail, NodeRefs, DistRefs),
+    available_internal_state(AIS),
+    R.
+
+check_node_dist(Fail, NodeRefs, DistRefs) ->
+    AIS = available_internal_state(true),
+    R = check_nd_refc({node(),erlang:system_info(creation)},
+                  NodeRefs, DistRefs, Fail),
+    available_internal_state(AIS),
+    R.
+
+
+check_nd_refc({ThisNodeName, ThisCreation}, NodeRefs, DistRefs, Fail) ->
+    case catch begin
+                   check_refc(ThisNodeName,ThisCreation,"node table",NodeRefs),
+                   check_refc(ThisNodeName,ThisCreation,"dist table",DistRefs),
+                   ok
+               end of
+        ok ->
+            ok;
+        {'EXIT', Reason} ->
+            {Y,Mo,D} = date(),
+            {H,Mi,S} = time(),
+            ErrMsg = io_lib:format("~n"
+                                   "*** Reference count check of node ~w "
+                                   "failed (~p) at ~w~w~w ~w:~w:~w~n"
+                                   "*** Node table references:~n ~p~n"
+                                   "*** Dist table references:~n ~p~n",
+                                   [node(), Reason, Y, Mo, D, H, Mi, S,
+                                    NodeRefs, DistRefs]),
+            Fail(lists:flatten(ErrMsg))
+    end.
+
+
+check_refc(ThisNodeName,ThisCreation,Table,EntryList) when is_list(EntryList) ->
+    lists:foreach(
+      fun ({Entry, Refc, ReferrerList}) ->
+              {DelayedDeleteTimer,
+               FoundRefs} =
+              lists:foldl(
+                fun ({Referrer, ReferencesList}, {DDT, A1}) ->
+                        {case Referrer of
+                             {system,delayed_delete_timer} ->
+                                 true;
+                             {system,thread_progress_delete_timer} ->
+                                 true;
+                             _ ->
+                                 DDT
+                         end,
+                         A1 + lists:foldl(fun ({_T,Rs},A2) ->
+                                                  A2+Rs
+                                          end,
+                                          0,
+                                          ReferencesList)}
+                end,
+                {false, 0},
+                ReferrerList),
+
+              %% Reference count equals found references?
+              case {Refc, FoundRefs, DelayedDeleteTimer} of
+                  {X, X, _} ->
+                      ok;
+                  {0, 1, true} ->
+                      ok;
+                  _ ->
+                      exit({invalid_reference_count, Table, Entry})
+              end,
+
+              %% All entries in table referred to?
+              case {Entry, Refc} of
+                  {ThisNodeName, 0} -> ok;
+                  {{ThisNodeName, ThisCreation}, 0} -> ok;
+                  {_, 0} when DelayedDeleteTimer == false ->
+                      exit({not_referred_entry_in_table, Table, Entry});
+                  {_, _} -> ok 
+              end
+
+      end,
+      EntryList),
+    ok.
diff --git a/erts/emulator/test/esock_misc/socket_client.erl b/erts/emulator/test/esock_misc/socket_client.erl
new file mode 100644
index 0000000000..1c07e799b8
--- /dev/null
+++ b/erts/emulator/test/esock_misc/socket_client.erl
@@ -0,0 +1,538 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2018-2018. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(socket_client).
+
+-export([
+         start/1, start/2, start/5, start/6,
+         start_tcp/1, start_tcp/2, start_tcp/3,
+         start_tcp4/1, start_tcp4/2, start_tcp6/1, start_tcp6/2,
+         start_udp/1, start_udp/2, start_udp/3,
+         start_udp4/1, start_udp4/2, start_udp6/1, start_udp6/2
+        ]).
+
+-define(LIB, socket_lib).
+
+-record(client, {socket, verbose = true, msg = true, type, dest, msg_id = 1}).
+
+start(Port) ->
+    start(Port, 1).
+
+start(Port, Num) ->
+    start_tcp(Port, Num).
+
+start_tcp(Port) ->
+    start_tcp(Port, 1).
+
+start_tcp(Port, Num) ->
+    start_tcp4(Port, Num).
+
+start_tcp4(Port) ->
+    start_tcp4(Port, 1).
+
+start_tcp4(Port, Num) ->
+    start(inet, stream, tcp, Port, Num).
+
+start_tcp6(Port) ->
+    start_tcp6(Port, 1).
+
+start_tcp6(Port, Num) ->
+    start(inet6, stream, tcp, Port, Num).
+
+start_tcp(Addr, Port, Num) when (size(Addr) =:= 4) andalso 
+                                is_integer(Num) andalso 
+                                (Num > 0) ->
+    start(inet, stream, tcp, Addr, Port, Num);
+start_tcp(Addr, Port, Num) when (size(Addr) =:= 8) andalso 
+                                is_integer(Num) andalso 
+                                (Num > 0) ->
+    start(inet6, stream, tcp, Addr, Port, Num).
+
+
+start_udp(Port) ->
+    start_udp(Port, 1).
+
+start_udp(Port, Num) ->
+    start_udp4(Port, Num).
+
+start_udp4(Port) ->
+    start_udp4(Port, 1).
+
+start_udp4(Port, Num) ->
+    start(inet, dgram, udp, Port, Num).
+
+start_udp6(Port) ->
+    start_udp6(Port, 1).
+
+start_udp6(Port, Num) ->
+    start(inet6, dgram, udp, Port, Num).
+
+start_udp(Addr, Port, Num) when (size(Addr) =:= 4) ->
+    start(inet, dgram, udp, Addr, Port, Num);
+start_udp(Addr, Port, Num) when (size(Addr) =:= 8) ->
+    start(inet6, dgram, udp, Addr, Port, Num).
+
+
+start(Domain, Type, Proto, Port, Num) 
+  when is_integer(Port) andalso is_integer(Num) ->
+    start(Domain, Type, Proto, which_addr(Domain), Port, Num);
+
+start(Domain, Type, Proto, Addr, Port) ->
+    start(Domain, Type, Proto, Addr, Port, 1).
+
+start(Domain, Type, Proto, Addr, Port, 1 = Num) ->
+    start(Domain, Type, Proto, Addr, Port, Num, true);
+start(Domain, Type, Proto, Addr, Port, Num) 
+  when is_integer(Num) andalso (Num > 1) ->
+    start(Domain, Type, Proto, Addr, Port, Num, false).
+
+start(Domain, Type, Proto, Addr, Port, Num, Verbose) ->
+    put(sname, "starter"),
+    Clients = start_clients(Num, Domain, Type, Proto, Addr, Port, Verbose),
+    await_clients(Clients).
+
+start_clients(Num, Domain, Type, Proto, Addr, Port, Verbose) ->
+    start_clients(Num, 1, Domain, Type, Proto, Addr, Port, Verbose, []).
+
+start_clients(Num, ID, Domain, Type, Proto, Addr, Port, Verbose, Acc) 
+  when (Num > 0) ->
+    StartClient = fun() ->
+                          start_client(ID, Domain, Type, Proto, Addr, Port, Verbose)
+                  end,
+    {Pid, _} = spawn_monitor(StartClient),
+    ?LIB:sleep(500),
+    i("start client ~w", [ID]),
+    start_clients(Num-1, ID+1, Domain, Type, Proto, Addr, Port, Verbose, [Pid|Acc]);
+start_clients(_, _, _, _, _, _, _, _, Acc) ->
+    i("all client(s) started"),
+    lists:reverse(Acc).
+
+await_clients([]) ->
+    i("all clients done");
+await_clients(Clients) ->
+    receive
+        {'DOWN', _MRef, process, Pid, _Reason} ->
+            case lists:delete(Pid, Clients) of
+                Clients2 when (Clients2 =/= Clients) ->
+                    i("client ~p done", [Pid]),
+                    await_clients(Clients2);
+                _ ->
+                    await_clients(Clients)
+            end
+    end.
+
+
+start_client(ID, Domain, Type, Proto, Addr, Port, Verbose) ->
+    put(sname, ?LIB:f("client[~w]", [ID])),
+    SA = #{family => Domain,
+           addr   => Addr,
+           port   => Port},
+    %% The way we use tos only works because we
+    %% send so few messages (a new value for every
+    %% message).
+    tos_init(),
+    do_start(Domain, Type, Proto, SA, Verbose).
+
+do_start(Domain, stream = Type, Proto, SA, Verbose) ->
+    try do_init(Domain, Type, Proto) of
+        Sock ->
+            connect(Sock, SA),
+            maybe_print_start_info(Verbose, Sock, Type),
+            %% Give the server some time...
+            ?LIB:sleep(5000),
+            %% ok = socket:close(Sock),
+            send_loop(#client{socket  = Sock, 
+                              type    = Type,
+                              verbose = Verbose})
+    catch
+        throw:E ->
+            e("Failed initiate: "
+              "~n   Error: ~p", [E])
+    end;
+do_start(Domain, dgram = Type, Proto, SA, Verbose) ->
+    try do_init(Domain, Type, Proto) of
+        Sock ->
+            maybe_print_start_info(Verbose, Sock, Type),
+            %% Give the server some time...
+            ?LIB:sleep(5000),
+            %% ok = socket:close(Sock),
+            send_loop(#client{socket  = Sock,
+                              type    = Type,
+                              dest    = SA,
+                              verbose = Verbose})
+    catch
+        throw:E ->
+            e("Failed initiate: "
+              "~n   Error: ~p", [E])
+    end.
+
+maybe_print_start_info(true = _Verbose, Sock, stream = _Type) ->
+    {ok, Name}    = socket:sockname(Sock),
+    {ok, Peer}    = socket:peername(Sock),
+    {ok, Domain}  = socket:getopt(Sock, socket, domain),
+    {ok, Type}    = socket:getopt(Sock, socket, type),
+    {ok, Proto}   = socket:getopt(Sock, socket, protocol),
+    {ok, OOBI}    = socket:getopt(Sock, socket, oobinline),
+    {ok, SndBuf}  = socket:getopt(Sock, socket, sndbuf),
+    {ok, RcvBuf}  = socket:getopt(Sock, socket, rcvbuf),
+    {ok, Linger}  = socket:getopt(Sock, socket, linger),
+    {ok, MTU}     = socket:getopt(Sock, ip,     mtu),
+    {ok, MTUDisc} = socket:getopt(Sock, ip,     mtu_discover),
+    {ok, MALL}    = socket:getopt(Sock, ip,     multicast_all),
+    {ok, MIF}     = socket:getopt(Sock, ip,     multicast_if),
+    {ok, MLoop}   = socket:getopt(Sock, ip,     multicast_loop),
+    {ok, MTTL}    = socket:getopt(Sock, ip,     multicast_ttl),
+    {ok, RecvTOS} = socket:getopt(Sock, ip,     recvtos),
+    i("connected: "
+      "~n   From: ~p"
+      "~n   To:   ~p"
+      "~nwhen"
+      "~n   (socket) Domain:         ~p"
+      "~n   (socket) Type:           ~p"
+      "~n   (socket) Protocol:       ~p"
+      "~n   (socket) OOBInline:      ~p"
+      "~n   (socket) SndBuf:         ~p"
+      "~n   (socket) RcvBuf:         ~p"
+      "~n   (socket) Linger:         ~p"
+      "~n   (ip)     MTU:            ~p"
+      "~n   (ip)     MTU Discovery:  ~p"
+      "~n   (ip)     Multicast ALL:  ~p"
+      "~n   (ip)     Multicast IF:   ~p"
+      "~n   (ip)     Multicast Loop: ~p"
+      "~n   (ip)     Multicast TTL:  ~p"
+      "~n   (ip)     RecvTOS:        ~p"
+      "~n   => wait some", 
+      [Name, Peer,
+       Domain, Type, Proto,
+       OOBI, SndBuf, RcvBuf, Linger,
+       MTU, MTUDisc, MALL, MIF, MLoop, MTTL,
+       RecvTOS]);
+maybe_print_start_info(true = _Verbose, Sock, dgram = _Type) ->
+    {ok, Domain}  = socket:getopt(Sock, socket, domain),
+    {ok, Type}    = socket:getopt(Sock, socket, type),
+    {ok, Proto}   = socket:getopt(Sock, socket, protocol),
+    {ok, OOBI}    = socket:getopt(Sock, socket, oobinline),
+    {ok, SndBuf}  = socket:getopt(Sock, socket, sndbuf),
+    {ok, RcvBuf}  = socket:getopt(Sock, socket, rcvbuf),
+    {ok, Linger}  = socket:getopt(Sock, socket, linger),
+    {ok, MALL}    = socket:getopt(Sock, ip,     multicast_all),
+    {ok, MIF}     = socket:getopt(Sock, ip,     multicast_if),
+    {ok, MLoop}   = socket:getopt(Sock, ip,     multicast_loop),
+    {ok, MTTL}    = socket:getopt(Sock, ip,     multicast_ttl),
+    {ok, RecvTOS} = socket:getopt(Sock, ip,     recvtos),
+    {ok, RecvTTL} = socket:getopt(Sock, ip,     recvttl),
+    i("initiated when: "
+      "~n   (socket) Domain:         ~p"
+      "~n   (socket) Type:           ~p"
+      "~n   (socket) Protocol:       ~p"
+      "~n   (socket) OOBInline:      ~p"
+      "~n   (socket) SndBuf:         ~p"
+      "~n   (socket) RcvBuf:         ~p"
+      "~n   (socket) Linger:         ~p"
+      "~n   (ip)     Multicast ALL:  ~p"
+      "~n   (ip)     Multicast IF:   ~p"
+      "~n   (ip)     Multicast Loop: ~p"
+      "~n   (ip)     Multicast TTL:  ~p"
+      "~n   (ip)     RecvTOS:        ~p"
+      "~n   (ip)     RecvTTL:        ~p"
+      "~n   => wait some",
+      [Domain, Type, Proto,
+       OOBI, SndBuf, RcvBuf, Linger,
+       MALL, MIF, MLoop, MTTL,
+       RecvTOS, RecvTTL]);
+maybe_print_start_info(_Verbose, _Sock, _Type) ->
+    ok.
+
+    
+do_init(Domain, stream = Type, Proto) ->
+    i("try (socket) open"),
+    Sock = case socket:open(Domain, Type, Proto) of
+               {ok, S} ->
+                   S;
+               {error, OReason} ->
+                   throw({open, OReason})
+           end,
+    i("try (socket) bind"),
+    case socket:bind(Sock, any) of
+        {ok, _P} ->
+            ok = socket:setopt(Sock, socket, timestamp, true),
+            ok = socket:setopt(Sock, ip,     tos,       mincost),
+            ok = socket:setopt(Sock, ip,     recvtos,   true),
+            Sock;
+        {error, BReason} ->
+            throw({bind, BReason})
+    end;
+do_init(Domain, dgram = Type, Proto) ->
+    i("try (socket) open"),
+    Sock = case socket:open(Domain, Type, Proto) of
+               {ok, S} ->
+                   S;
+               {error, OReason} ->
+                   throw({open, OReason})
+           end,
+    case socket:bind(Sock, any) of
+        {ok, _} ->
+            ok = socket:setopt(Sock, socket, timestamp, true),
+            ok = socket:setopt(Sock, ip,     tos,       mincost),
+            ok = socket:setopt(Sock, ip,     recvtos,   true),
+            ok = socket:setopt(Sock, ip,     recvttl,   true),
+            Sock;
+        {error, BReason} ->
+            throw({bind, BReason})
+    end.
+
+
+which_addr(Domain) ->
+    Iflist = case inet:getifaddrs() of
+                 {ok, IFL} ->
+                     IFL;
+                 {error, Reason} ->
+                     throw({inet,getifaddrs,Reason})
+             end,
+    which_addr(Domain, Iflist).
+
+
+connect(Sock, SA) ->
+    i("try (socket) connect to:"
+      "~n   ~p", [SA]),
+    case socket:connect(Sock, SA) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            e("connect failure: "
+              "~n   ~p", [Reason]),
+            exit({connect, Reason})
+    end.
+
+
+send_loop(#client{msg_id = N} = C) when (N =< 10) ->
+    i("try send request ~w", [N]),
+    Req = ?LIB:enc_req_msg(N, "hejsan"),
+    case send(C, Req) of
+        ok ->
+            i("request ~w sent - now try read answer", [N]),
+            case recv(C) of
+                {ok, {Source, Msg}} ->
+                    if
+                        (C#client.verbose =:= true) ->
+                            i("received ~w bytes of data~s", 
+                              [size(Msg),  case Source of
+                                               undefined -> "";
+                                               _ -> ?LIB:f(" from:~n   ~p", [Source])
+                                           end]);
+                        true ->
+                            i("received ~w bytes", [size(Msg)])
+                    end,
+                    case ?LIB:dec_msg(Msg) of
+                        {reply, N, Reply} ->
+                            if
+                                (C#client.verbose =:= true) ->
+                                    i("received reply ~w: ~p", [N, Reply]);
+                                true ->
+                                    i("received reply ~w", [N])
+                            end,
+                            ?LIB:sleep(500), % Just to spread it out a bit
+                            send_loop(C#client{msg_id = N+1})
+                    end;
+                {error, RReason} ->
+                    e("Failed recv response for request ~w: "
+                      "~n   ~p", [N, RReason]),
+                    exit({failed_recv, RReason})
+            end;
+        {error, SReason} ->
+            e("Failed send request ~w: "
+              "~n   ~p", [N, SReason]),
+            exit({failed_send, SReason})
+    end;
+send_loop(Client) ->
+    sock_close(Client).
+
+sock_close(#client{socket = Sock, verbose = true}) ->
+    i("we are done - close the socket when: "
+      "~n   ~p", [socket:info()]),
+    ok = socket:close(Sock),
+    i("we are done - socket closed when: "
+      "~n   ~p", [socket:info()]);
+sock_close(#client{socket = Sock}) ->
+    i("we are done"),
+    ok = socket:close(Sock).
+
+    
+
+send(#client{socket = Sock, type = stream}, Msg) ->
+    socket:send(Sock, Msg);
+send(#client{socket = Sock, type = dgram, dest = Dest}, Msg) ->
+    %% i("try send to: "
+    %%   "~n   ~p", [Dest]),
+    %% ok = socket:setopt(Sock, otp, debug, true),
+    TOS = tos_next(),
+    ok = socket:setopt(Sock, ip, tos, TOS),
+    case socket:sendto(Sock, Msg, Dest) of
+        ok = OK ->
+            OK;
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+recv(#client{socket = Sock, type = stream, msg = false}) ->
+    case socket:recv(Sock) of
+        {ok, Msg} ->
+            {ok, {undefined, Msg}};
+        {error, _} = ERROR ->
+            ERROR
+    end;
+recv(#client{socket = Sock, verbose = Verbose, type = stream, msg = true}) ->
+    case socket:recvmsg(Sock) of
+        %% An iov of length 1 is an simplification...
+        {ok, #{addr  := undefined = Source,
+               iov   := [Msg],
+               ctrl  := CMsgHdrs,
+               flags := Flags}} ->
+            if
+                (Verbose =:= true) ->
+                    i("received message: "
+                      "~n   CMsgHdr: ~p"
+                      "~n   Flags:   ~p", [CMsgHdrs, Flags]);
+                true ->
+                    ok
+                        end,
+            {ok, {Source, Msg}};
+        {error, _} = ERROR ->
+            ERROR
+    end;
+recv(#client{socket = Sock, type = dgram, msg = false}) ->
+    socket:recvfrom(Sock);
+recv(#client{socket = Sock, verbose = Verbose, type = dgram, msg = true}) ->
+    case socket:recvmsg(Sock) of
+        {ok, #{addr  := Source,
+               iov   := [Msg],
+               ctrl  := CMsgHdrs,
+               flags := Flags}} ->
+            if
+                (Verbose =:= true) ->
+                    i("received message: "
+                      "~n   CMsgHdr: ~p"
+                      "~n   Flags:   ~p", [CMsgHdrs, Flags]);
+                true ->
+                    ok
+            end,
+            {ok, {Source, Msg}};
+        {error, _} = ERROR ->
+            ERROR
+    end.
+        
+
+
+which_addr(_Domain, []) ->
+    throw(no_address);
+which_addr(Domain, [{Name, IFO}|_IFL]) when (Name =/= "lo") ->
+    which_addr2(Domain, IFO);
+which_addr(Domain, [_|IFL]) ->
+    which_addr(Domain, IFL).
+
+which_addr2(inet = _Domain, [{addr, Addr}|_IFO]) when (size(Addr) =:= 4) ->
+    Addr;
+which_addr2(inet6 = _Domain, [{addr, Addr}|_IFO]) when (size(Addr) =:= 8) ->
+    Addr;
+which_addr2(Domain, [_|IFO]) ->
+    which_addr2(Domain, IFO).
+
+
+%% ---
+
+%% enc_req_msg(N, Data) ->
+%%     enc_msg(?REQ, N, Data).
+
+%% enc_rep_msg(N, Data) ->
+%%     enc_msg(?REP, N, Data).
+
+%% enc_msg(Type, N, Data) when is_list(Data) ->
+%%     enc_msg(Type, N, list_to_binary(Data));
+%% enc_msg(Type, N, Data) 
+%%   when is_integer(Type) andalso is_integer(N) andalso is_binary(Data) ->
+%%     <<Type:32/integer, N:32/integer, Data/binary>>.
+    
+%% dec_msg(<<?REQ:32/integer, N:32/integer, Data/binary>>) ->
+%%     {request, N, Data};
+%% dec_msg(<<?REP:32/integer, N:32/integer, Data/binary>>) ->
+%%     {reply, N, Data}.
+
+
+%% ---
+
+%% sleep(T) ->
+%%     receive after T -> ok end.
+
+                     
+%% ---
+
+%% formated_timestamp() ->
+%%     format_timestamp(os:timestamp()).
+
+%% format_timestamp(Now) ->
+%%     N2T = fun(N) -> calendar:now_to_local_time(N) end,
+%%     format_timestamp(Now, N2T, true).
+
+%% format_timestamp({_N1, _N2, N3} = N, N2T, true) ->
+%%     FormatExtra = ".~.2.0w",
+%%     ArgsExtra   = [N3 div 10000],
+%%     format_timestamp(N, N2T, FormatExtra, ArgsExtra);
+%% format_timestamp({_N1, _N2, _N3} = N, N2T, false) ->
+%%     FormatExtra = "",
+%%     ArgsExtra   = [],
+%%     format_timestamp(N, N2T, FormatExtra, ArgsExtra).
+
+%% format_timestamp(N, N2T, FormatExtra, ArgsExtra) ->
+%%     {Date, Time}   = N2T(N),
+%%     {YYYY,MM,DD}   = Date,
+%%     {Hour,Min,Sec} = Time,
+%%     FormatDate =
+%%         io_lib:format("~.4w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w" ++ FormatExtra,
+%%                       [YYYY, MM, DD, Hour, Min, Sec] ++ ArgsExtra),
+%%     lists:flatten(FormatDate).
+
+
+%% ---
+
+tos_init() ->
+    put(tos, 1).
+
+tos_next() ->
+    case get(tos) of
+        TOS when (TOS < 100) ->
+            put(tos, TOS + 1),
+            TOS;
+        _ ->
+            put(tos, 1),
+            1
+    end.
+
+
+%% ---
+
+e(F, A) ->
+    ?LIB:e(F, A).
+
+i(F) ->
+    ?LIB:i(F).
+
+i(F, A) ->
+    ?LIB:i(F, A).
+    
diff --git a/erts/emulator/test/esock_misc/socket_lib.erl b/erts/emulator/test/esock_misc/socket_lib.erl
new file mode 100644
index 0000000000..9d6524d467
--- /dev/null
+++ b/erts/emulator/test/esock_misc/socket_lib.erl
@@ -0,0 +1,133 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2018-2018. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(socket_lib).
+
+-export([
+         sleep/1,
+         req/0, rep/0,
+         enc_req_msg/2, enc_rep_msg/2,
+         enc_msg/3, dec_msg/1,
+         request/3, reply/4,
+         f/2,
+         i/1, i/2,
+         e/2
+        ]).
+
+
+-define(REQ, 0).
+-define(REP, 1).
+
+
+%% ---
+
+sleep(T) ->
+    receive after T -> ok end.
+
+
+%% ---
+
+req() -> ?REQ.
+rep() -> ?REP.
+
+enc_req_msg(N, Data) ->
+    enc_msg(?REQ, N, Data).
+
+enc_rep_msg(N, Data) ->
+    enc_msg(?REP, N, Data).
+
+enc_msg(Type, N, Data) when is_list(Data) ->
+    enc_msg(Type, N, list_to_binary(Data));
+enc_msg(Type, N, Data) 
+  when is_integer(Type) andalso is_integer(N) andalso is_binary(Data) ->
+    <<Type:32/integer, N:32/integer, Data/binary>>.
+    
+dec_msg(<<?REQ:32/integer, N:32/integer, Data/binary>>) ->
+    {request, N, Data};
+dec_msg(<<?REP:32/integer, N:32/integer, Data/binary>>) ->
+    {reply, N, Data}.
+
+
+%% ---
+
+request(Tag, Pid, Request) ->
+    Ref = make_ref(),
+    Pid ! {Tag, self(), Ref, Request},
+    receive
+        {Tag, Pid, Ref, Reply} ->
+            Reply
+    end.
+    
+reply(Tag, Pid, Ref, Reply) ->
+    Pid ! {Tag, self(), Ref, Reply}.
+
+
+%% ---
+
+f(F, A) ->
+    lists:flatten(io_lib:format(F, A)).
+
+
+%% ---
+
+e(F, A) ->
+    p("<ERROR> " ++ F, A).
+
+i(F) ->
+    i(F, []).
+i(F, A) ->
+    p("*** " ++ F, A).
+
+p(F, A) ->
+    p(get(sname), F, A).
+
+p(SName, F, A) ->
+    io:format("[~s,~p][~s] " ++ F ++ "~n", 
+              [SName,self(),formated_timestamp()|A]).
+
+
+%% ---
+
+formated_timestamp() ->
+    format_timestamp(os:timestamp()).
+
+format_timestamp(Now) ->
+    N2T = fun(N) -> calendar:now_to_local_time(N) end,
+    format_timestamp(Now, N2T, true).
+
+format_timestamp({_N1, _N2, N3} = N, N2T, true) ->
+    FormatExtra = ".~.2.0w",
+    ArgsExtra   = [N3 div 10000],
+    format_timestamp(N, N2T, FormatExtra, ArgsExtra);
+format_timestamp({_N1, _N2, _N3} = N, N2T, false) ->
+    FormatExtra = "",
+    ArgsExtra   = [],
+    format_timestamp(N, N2T, FormatExtra, ArgsExtra).
+
+format_timestamp(N, N2T, FormatExtra, ArgsExtra) ->
+    {Date, Time}   = N2T(N),
+    {YYYY,MM,DD}   = Date,
+    {Hour,Min,Sec} = Time,
+    FormatDate =
+        io_lib:format("~.4w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w" ++ FormatExtra,
+                      [YYYY, MM, DD, Hour, Min, Sec] ++ ArgsExtra),
+    lists:flatten(FormatDate).
+
+
diff --git a/erts/emulator/test/esock_misc/socket_server.erl b/erts/emulator/test/esock_misc/socket_server.erl
new file mode 100644
index 0000000000..45adffc5e6
--- /dev/null
+++ b/erts/emulator/test/esock_misc/socket_server.erl
@@ -0,0 +1,954 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2018-2018. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(socket_server).
+
+-export([
+         start/0, start/5,
+         start_tcp/0,  start_tcp/1,  start_tcp/3,
+         start_tcp4/0, start_tcp4/1, start_tcp4/2,
+         start_tcp6/0, start_tcp6/1, start_tcp6/2,
+         start_udp/0,  start_udp/1,  start_udp/3,
+         start_udp4/0, start_udp4/1, start_udp4/2,
+         start_udp6/0, start_udp6/1, start_udp6/2,
+         start_sctp/0, start_sctp/1
+        ]).
+
+-define(LIB, socket_lib).
+
+-record(manager,  {socket, msg, peek, acceptors, handler_id, handlers}).
+-record(acceptor, {id, socket, manager, 
+                   atimeout = 5000}).
+-record(handler,  {socket, peek, msg, type, manager, 
+                   stimeout = 5000, rtimeout = 5000}).
+
+-define(NUM_ACCEPTORS, 5).
+
+start() ->
+    start_tcp().
+
+start_tcp() ->
+    start_tcp4().
+
+start_tcp(Peek) ->
+    start_tcp4(Peek).
+
+start_tcp4() ->
+    start_tcp4(false).
+
+start_tcp4(Peek) ->
+    start_tcp4(false, Peek).
+
+start_tcp4(UseMsg, Peek) ->
+    start_tcp(inet, UseMsg, Peek).
+
+start_tcp6() ->
+    start_tcp6(false).
+
+start_tcp6(Peek) ->
+    start_tcp6(false, Peek).
+
+start_tcp6(UseMsg, Peek) ->
+    start_tcp(inet6, UseMsg, Peek).
+
+start_tcp(Domain, UseMsg, Peek) when is_boolean(UseMsg) andalso is_boolean(Peek) ->
+    start(Domain, stream, tcp, UseMsg, Peek).
+
+start_udp() ->
+    start_udp4().
+
+start_udp(Peek) ->
+    start_udp4(Peek).
+
+start_udp4() ->
+    start_udp4(false).
+
+start_udp4(Peek) ->
+    start_udp4(false, Peek).
+
+start_udp4(UseMsg, Peek) ->
+    start_udp(inet, UseMsg, Peek).
+
+start_udp6() ->
+    start_udp6(false, false).
+
+start_udp6(Peek) ->
+    start_udp6(false, Peek).
+
+start_udp6(UseMsg, Peek) ->
+    start_udp(inet6, UseMsg, Peek).
+
+start_udp(Domain, UseMsg, Peek) when is_boolean(UseMsg) andalso is_boolean(Peek) ->
+    start(Domain, dgram, udp, UseMsg, Peek).
+
+
+start_sctp() ->
+    start_sctp(inet).
+
+start_sctp(Domain) when ((Domain =:= inet) orelse (Domain =:= inet6)) ->
+    start(Domain, seqpacket, sctp, true, false).
+
+start(Domain, Type, Proto, UseMsg, Peek) ->
+    put(sname, "starter"),
+    i("try start manager"),
+    {Pid, MRef} = manager_start(Domain, Type, Proto, UseMsg, Peek),
+    i("manager (~p) started", [Pid]),
+    loop(Pid, MRef).
+
+loop(Pid, MRef) ->
+    receive
+        {'DOWN', MRef, process, Pid, Reason} ->
+            i("manager process exited: "
+              "~n   ~p", [Reason]),
+            ok
+    end.
+
+
+%% =========================================================================
+
+manager_start(Domain, Type, Proto, UseMsg, Peek) ->
+    spawn_monitor(fun() -> manager_init(Domain, Type, Proto, UseMsg, Peek) end).
+
+manager_start_handler(Pid, Sock) ->
+    manager_request(Pid, {start_handler, Sock}).
+
+manager_stop(Pid, Reason) ->
+    manager_request(Pid, {stop, Reason}).
+
+manager_request(Pid, Request) ->
+    ?LIB:request(manager, Pid, Request).
+
+manager_reply(Pid, Ref, Reply) ->
+    ?LIB:reply(manager, Pid, Ref, Reply).
+
+
+manager_init(Domain, Type, Proto, UseMsg, Peek) ->
+    put(sname, "manager"),
+    do_manager_init(Domain, Type, Proto, UseMsg, Peek).
+
+do_manager_init(Domain, stream = Type, Proto, UseMsg, Peek) ->
+    i("try start acceptor(s)"),
+    {Sock, Acceptors} = manager_stream_init(Domain, Type, Proto),
+    manager_loop(#manager{socket     = Sock,
+                          msg        = UseMsg,
+                          peek       = Peek,
+                          acceptors  = Acceptors,
+                          handler_id = 1,
+                          handlers   = []});
+do_manager_init(Domain, dgram = Type, Proto, UseMsg, Peek) ->
+    i("try open socket"),
+    case socket:open(Domain, Type, Proto) of
+        {ok, Sock} ->
+            F = fun(X) -> case socket:getopt(Sock, socket, X) of
+                              {ok, V} ->    f("~p", [V]);
+                              {error, R} -> f("error: ~p", [R])
+                          end
+                end,
+            i("socket opened (~s,~s,~s): "
+              "~n   broadcast: ~s"
+              "~n   dontroute: ~s"
+              "~n   keepalive: ~s"
+              "~n   reuseaddr: ~s"
+              "~n   linger:    ~s"
+              "~n   debug:     ~s"
+              "~n   prio:      ~s"
+              "~n   rcvbuf:    ~s"
+              "~n   rcvtimeo:  ~s"
+              "~n   sndbuf:    ~s"
+              "~n   sndtimeo:  ~s"
+              "~n   => try find (local) address", 
+              [F(domain), F(type), F(protocol), 
+               F(broadcast), F(dontroute), F(keepalive), F(reuseaddr), F(linger),
+               F(debug), F(priority), 
+               F(rcvbuf), F(rcvtimeo), F(sndbuf), F(sndtimeo)]),
+            Addr = which_addr(Domain),
+            SA = #{family => Domain,
+                   addr   => Addr},
+            i("try bind to: "
+              "~n   ~p", [Addr]),
+            case socket:bind(Sock, SA) of
+                {ok, _P} ->
+                   ok;
+                {error, BReason} ->
+                    throw({bind, BReason})
+            end,
+            i("bound to: "
+              "~n   ~s"
+              "~n   => try start handler", 
+              [case socket:sockname(Sock) of
+                   {ok, Name} -> f("~p", [Name]);
+                   {error, R} -> f("error: ~p", [R])
+               end]),
+            case handler_start(1, Sock, UseMsg, Peek) of
+                {ok, {Pid, MRef}} ->
+                    i("handler (~p) started", [Pid]),
+                    handler_continue(Pid),
+                    manager_loop(#manager{peek       = Peek,
+                                          msg        = UseMsg,
+                                          handler_id = 2, % Just in case
+                                          handlers   = [{1, Pid, MRef}]});
+                {error, SReason} ->
+                    e("Failed starting handler: "
+                      "~n   ~p", [SReason]),
+                    exit({failed_start_handler, SReason})
+            end;
+        {error, OReason} ->
+            e("Failed open socket: "
+              "~n   ~p", [OReason]),
+            exit({failed_open_socket, OReason})
+    end;
+do_manager_init(Domain, seqpacket = Type, sctp = Proto, _UseMsg, _Peek) ->
+    %% This is as far as I have got with SCTP at the moment...
+    case socket:open(Domain, Type, Proto) of
+        {ok, Sock} ->
+            i("(sctp) socket opened: "
+              "~n   ~p", [Sock]),
+            EXP = fun(_Desc, Expect, Expect) ->
+                          Expect;
+                     (Desc, Expect, Actual) ->
+                          e("Unexpected result ~w: "
+                            "~n   Expect: ~p"
+                            "~n   Actual: ~p", [Desc, Expect, Actual]),
+                          exit({Desc, Expect, Actual})
+                  end,
+            GO = fun(O) -> case socket:getopt(Sock, sctp, O) of
+                               {ok, V}    -> f("~p", [V]);
+                               {error, R} -> f("error: ~p", [R])
+                           end
+                 end,
+            %% ok = socket:setopt(Sock, otp, debug, true),
+
+            i("Miscellaneous options: "
+              "~n   associnfo:         ~s"
+              "~n   autoclose:         ~s"
+              "~n   disable-fragments: ~s"
+              "~n   initmsg:           ~s"
+              "~n   maxseg:            ~s"
+              "~n   nodelay:           ~s"
+              "~n   rtoinfo:           ~s", 
+              [GO(associnfo),
+               GO(autoclose),
+               GO(disable_fragments),
+               GO(initmsg),
+               GO(maxseg),
+               GO(nodelay),
+               GO(rtoinfo)]),
+
+            Events = #{data_in          => true,
+                       association      => true,
+                       address          => true,
+                       send_failure     => true,
+                       peer_error       => true,
+                       shutdown         => true,
+                       partial_delivery => true,
+                       adaptation_layer => true,
+                       authentication   => true,
+                       sender_dry       => true},
+            EXP(set_sctp_events, ok, socket:setopt(Sock, sctp, events, Events)),
+            EXP(close_socket, ok, socket:close(Sock));
+        {error, Reason} ->
+            exit({failed_open, Reason})
+    end;
+do_manager_init(Domain, raw = Type, Proto, UseMsg, Peek) when is_integer(Proto) ->
+    do_manager_init(Domain, Type, {raw, Proto}, UseMsg, Peek);
+do_manager_init(Domain, raw = Type, Proto, _UseMsg, _Peek) ->
+    case socket:open(Domain, Type, Proto) of
+        {ok, Sock} ->
+            i("(sctp) socket opened: "
+              "~n   ~p", [Sock]),
+            socket:close(Sock);
+        {error, Reason} ->
+            exit({failed_open, Reason})
+    end.
+
+
+
+manager_stream_init(Domain, Type, Proto) ->
+    i("try (socket) open"),
+    Sock = case socket:open(Domain, Type, Proto) of
+               {ok, S} ->
+                   S;
+               {error, OReason} ->
+                   throw({open, OReason})
+           end,
+    F = fun(X) -> case socket:getopt(Sock, socket, X) of
+                      {ok, V} ->    f("~p", [V]);
+                      {error, R} -> f("error: ~p", [R])
+                  end
+        end,
+    i("(socket) open (~s,~s,~s): "
+      "~n   debug:     ~s"
+      "~n   prio:      ~s"
+      "~n   => try find (local) address", 
+      [F(domain), F(type), F(protocol), F(debug), F(priority)]),
+    Addr = which_addr(Domain),
+    SA = #{family => Domain,
+           addr   => Addr},
+    i("found: "
+      "~n   ~p"
+      "~n   => try (socket) bind", [Addr]),
+    %% ok = socket:setopt(Sock, otp, debug, true),
+    %% ok = socket:setopt(Sock, socket, debug, 1), %% must have rights!!
+    Port = case socket:bind(Sock, SA) of
+               {ok, P} ->
+                   %% ok = socket:setopt(Sock, socket, debug, 0), %% must have rights!!
+                   %% ok = socket:setopt(Sock, otp, debug, false),
+                   P;
+               {error, BReason} ->
+                   throw({bind, BReason})
+           end,
+    i("bound to: "
+      "~n   ~p"
+      "~n   => try (socket) listen (acceptconn: ~s)", 
+      [Port, F(acceptconn)]),
+    case socket:listen(Sock) of
+        ok ->
+            i("listening (acceptconn: ~s)", 
+              [F(acceptconn)]),
+            manager_stream_init(Sock, 1, ?NUM_ACCEPTORS, []);
+        {error, LReason} ->
+            throw({listen, LReason})
+    end.
+
+which_addr(Domain) ->
+    Iflist = case inet:getifaddrs() of
+                 {ok, IFL} ->
+                     IFL;
+                 {error, Reason} ->
+                     throw({inet,getifaddrs,Reason})
+             end,
+    which_addr(Domain, Iflist).
+
+which_addr(_Domain, []) ->
+    throw(no_address);
+which_addr(Domain, [{Name, IFO}|_IFL]) when (Name =/= "lo") ->
+    which_addr2(Domain, IFO);
+which_addr(Domain, [_|IFL]) ->
+    which_addr(Domain, IFL).
+
+which_addr2(_, []) ->
+    throw(no_address);
+which_addr2(inet = _Domain, [{addr, Addr}|_IFO]) when (size(Addr) =:= 4) ->
+    Addr;
+which_addr2(inet6 = _Domain, [{addr, Addr}|_IFO]) when (size(Addr) =:= 8) ->
+    Addr;
+which_addr2(Domain, [_|IFO]) ->
+    which_addr2(Domain, IFO).
+
+
+manager_stream_init(Sock, ID, NumAcceptors, Acc) 
+  when (NumAcceptors > 0) ->
+    i("try start acceptor"),
+    case acceptor_start(Sock, ID) of
+        {ok, {Pid, MRef}} ->
+            i("acceptor ~w (~p) started", [ID, Pid]),
+            ?LIB:sleep(2000),
+            manager_stream_init(Sock, ID+1, NumAcceptors-1, 
+                                [{ID, Pid, MRef}|Acc]);
+        {error, Reason} ->
+            exit({failed_starting_acceptor, Reason})
+    end;
+manager_stream_init(Sock, _ID, 0, Acc) ->
+    %% Req = {kill_acceptor, length(Acc)}, % Last in the queue
+    %% Req = {kill_acceptor, 3},           % In the "middle" of the queue
+    %% Req = {kill_acceptor, 2},           % The first in the queue
+    %% Req = {kill_acceptor, 1},           % Current acceptor
+    %% Msg = {manager, self(), make_ref(), Req},
+    %% erlang:send_after(timer:seconds(10), self(), Msg),
+    {Sock, lists:reverse(Acc)}.
+
+
+manager_loop(M) ->
+    receive
+        {'DOWN', MRef, process, Pid, Reason} ->
+            M2 = manager_handle_down(M, MRef, Pid, Reason),
+            manager_loop(M2);
+        
+        {manager, Pid, Ref, Request} ->
+            M2 = manager_handle_request(M, Pid, Ref, Request),
+            manager_loop(M2)
+    end.
+
+
+manager_handle_down(#manager{acceptors = Acceptors,
+                             handlers  = Handlers} = M, MRef, Pid, Reason) ->
+    case lists:keysearch(Pid, 2, Acceptors) of
+        {value, {ID, Pid, MRef}} when (Reason =:= normal) ->
+            i("acceptor ~w exited (normally)", [ID]),
+            case lists:keydelete(Pid, 2, Acceptors) of
+                [] ->
+                    %% We are done
+                    i("the last acceptor - we are done"),
+                    exit(normal);
+                Acceptors2 ->
+                    M#manager{acceptors = Acceptors2}
+            end;
+        {value, {ID, Pid, MRef}} ->
+            e("acceptor ~w crashed: "
+              "~n   ~p", [ID, Reason]),
+            exit({acceptor_died, Reason});
+
+        false -> %% handler!
+            if
+                (Reason =/= normal) ->
+                    e("handler ~p died: "
+                      "~n   ~p", [Pid, Reason]);
+                true ->
+                    i("handler ~p terminated", [Pid])
+            end,
+            Handlers2 = lists:keydelete(Pid, 2, Handlers),
+            M#manager{handlers = Handlers2}
+    end.
+
+
+manager_handle_request(#manager{peek       = Peek,
+                                msg        = UseMsg,
+                                handler_id = HID,
+                                handlers   = Handlers} = M, Pid, Ref,
+                       {start_handler, Sock}) ->
+    i("try start handler (~w)", [HID]),
+    case handler_start(HID, Sock, UseMsg, Peek) of
+        {ok, {HPid, HMRef}} ->
+            i("handler ~w started", [HID]),
+            manager_reply(Pid, Ref, {ok, HPid}),
+            M#manager{handler_id = HID+1,
+                      handlers   = [{HID, HPid, HMRef}|Handlers]};
+        {error, Reason} = ERROR ->
+            e("Failed starting new handler: "
+              "~n   Sock:   ~p"
+              "~n   Reason: ~p", [Sock, Reason]),
+            manager_reply(Pid, Ref, ERROR),
+            M
+    end;
+manager_handle_request(#manager{socket    = Sock,
+                                acceptors = [{AID, APid, AMRef}]} = M, _Pid, _Ref,
+                       {kill_acceptor, AID}) ->
+    i("try kill (only remeining) acceptor ~w", [AID]),
+    socket:setopt(Sock, otp, debug, true),
+    manager_stop_acceptor(APid, AMRef, AID, kill),
+    M#manager{acceptors = []};
+manager_handle_request(#manager{socket    = Sock,
+                                acceptors = Acceptors} = M, _Pid, _Ref,
+                       {kill_acceptor, AID}) ->
+    i("try kill acceptor ~w", [AID]),
+    case lists:keysearch(AID, 1, Acceptors) of
+        {value, {AID, APid, AMRef}} ->
+            socket:setopt(Sock, otp, debug, true),
+            manager_stop_acceptor(APid, AMRef, AID, kill),
+            Acceptors2 = lists:keydelete(AID, 1, Acceptors),
+            M#manager{acceptors = Acceptors2};
+        false ->
+            e("no such acceptor"),
+            M
+    end;
+manager_handle_request(#manager{acceptors = Acceptors,
+                                handlers  = Handlers}, Pid, Ref,
+                       {stop, Reason}) ->
+    i("stop"),
+    manager_reply(Pid, Ref, ok),
+    manager_stop_handlers(Handlers, Reason),
+    manager_stop_acceptors(Acceptors, Reason),
+    i("stopped", []),
+    exit(Reason).
+
+manager_stop_acceptors(Acceptors, Reason) ->
+    lists:foreach(fun({ID,P,M}) -> 
+                          manager_stop_acceptor(P, M, ID, Reason) 
+                  end, Acceptors).
+    
+manager_stop_acceptor(Pid, MRef, ID, Reason) ->
+    i("try stop acceptor ~w (~p): ~p", [ID, Pid, Reason]),
+    erlang:demonitor(MRef, [flush]),
+    acceptor_stop(Pid, Reason),
+    ok.
+
+manager_stop_handlers(Handlers, Reason) ->
+    lists:foreach(fun({ID,P,M}) -> 
+                          manager_stop_handler(P, M, ID, Reason) 
+                  end, Handlers).
+
+manager_stop_handler(Pid, MRef, ID, Reason) ->
+    i("try stop handler ~w (~p): ~p", [ID, Pid, Reason]),
+    erlang:demonitor(MRef, [flush]),
+    handler_stop(Pid, Reason),
+    ok.
+
+    
+
+%% =========================================================================
+
+acceptor_start(Sock, ID) ->
+    Self = self(),
+    A = {Pid, _} = spawn_monitor(fun() -> 
+                                         acceptor_init(Self, Sock, ID) 
+                                 end),
+    receive
+        {acceptor, Pid, ok} ->
+            {ok, A};
+        {acceptor, Pid, {error, _} = Error} ->
+            exit(Pid, kill), % Just in case
+            Error;
+        {'DOWN', _MRef, process, Pid, Reason} ->
+            {error, {crashed, Reason}}
+    end.
+
+acceptor_stop(Pid, _Reason) ->
+    %% acceptor_request(Pid, {stop, Reason}).
+    exit(Pid, kill).
+
+%% acceptor_request(Pid, Request) ->
+%%     request(acceptor, Pid, Request).
+
+%% acceptor_reply(Pid, Ref, Reply) ->
+%%     reply(acceptor, Pid, Ref, Reply).
+
+
+acceptor_init(Manager, Sock, ID) ->
+    put(sname, f("acceptor[~w]", [ID])),
+    Manager ! {acceptor, self(), ok},
+    %% ok = socket:setopt(Sock, otp, debug, true),
+    acceptor_loop(#acceptor{id      = ID,
+                            manager = Manager,
+                            socket  = Sock}).
+
+acceptor_loop(#acceptor{socket = LSock, atimeout = Timeout} = A) ->
+    i("try accept"),
+    case socket:accept(LSock, Timeout) of
+        {ok, Sock} ->
+            i("accepted: "
+              "~n   ~p"
+              "~nwhen"
+              "~n   ~p", [Sock, socket:info()]),
+            case acceptor_handle_accept_success(A, Sock) of
+                ok ->
+                    acceptor_loop(A);
+                {error, Reason} ->
+                    e("Failed starting handler: "
+                      "~n   ~p", [Reason]),
+                    socket:close(Sock),
+                    exit({failed_starting_handler, Reason})
+            end;
+        {error, timeout} ->
+            i("timeout"),
+            acceptor_loop(A);
+        {error, Reason} ->
+            e("accept failure: "
+              "~n   ~p", [Reason]),
+            exit({accept, Reason})
+    end.
+
+acceptor_handle_accept_success(#acceptor{manager = Manager}, Sock) ->
+    i("try start handler for peer"
+      "~n   ~p", [case socket:peername(Sock) of
+                      {ok, Peer} -> Peer;
+                      {error, _} = E -> E
+                  end]),
+    case manager_start_handler(Manager, Sock) of
+        {ok, Pid} ->
+            i("handler (~p) started - now change 'ownership'", [Pid]),
+            case socket:setopt(Sock, otp, controlling_process, Pid) of
+                ok ->
+                    %% Normally we should have a msgs collection here
+                    %% (of messages we receive before the control was
+                    %% handled over to Handler), but since we don't 
+                    %% have active implemented yet...
+                    i("new handler (~p) now controlling process", [Pid]),
+                    handler_continue(Pid),
+                    ok;
+                {error, _} = ERROR ->
+                    exit(Pid, kill),
+                    ERROR
+            end;
+        {error, Reason2} ->
+            e("failed starting handler: "
+              "~n   (new) Socket: ~p"
+              "~n   Reason:       ~p", [Sock, Reason2]),
+            exit({failed_starting_handler, Reason2})
+    end.
+
+
+
+%% =========================================================================
+
+handler_start(ID, Sock, UseMsg, Peek) ->
+    Self = self(),
+    H = {Pid, _} = spawn_monitor(fun() ->
+                                         handler_init(Self, ID, UseMsg, Peek, Sock)
+                                 end),
+    receive
+        {handler, Pid, ok} ->
+            {ok, H};
+        {handler, Pid, {error, _} = ERROR} ->
+            exit(Pid, kill), % Just in case
+            ERROR
+    end.
+
+handler_stop(Pid, _Reason) ->
+    %% handler_request(Pid, {stop, Reason}).
+    exit(Pid, kill).
+
+handler_continue(Pid) ->
+    handler_request(Pid, continue).
+
+handler_request(Pid, Request) ->
+    ?LIB:request(handler, Pid, Request).
+
+handler_reply(Pid, Ref, Reply) ->
+    ?LIB:reply(handler, Pid, Ref, Reply).
+
+
+handler_init(Manager, ID, Msg, Peek, Sock) ->
+    put(sname, f("handler:~w", [ID])),
+    i("starting"),
+    Manager ! {handler, self(), ok},
+    receive
+        {handler, Pid, Ref, continue} ->
+            i("got continue"),
+            handler_reply(Pid, Ref, ok),
+            G = fun(L, O) -> case socket:getopt(Sock, L, O) of
+                                {ok, Val} ->
+                                    f("~p", [Val]);
+                                {error, R} when is_atom(R) ->
+                                    f("error: ~w", [R]);
+                                {error, {T, R}} when is_atom(T) ->
+                                    f("error: ~w, ~p", [T, R]);
+                                {error, R} ->
+                                    f("error: ~p", [R])
+                          end
+                end,
+            GSO  = fun(O) -> G(socket, O) end,
+            GIP4 = fun(O) -> G(ip,     O) end,
+            GIP6 = fun(O) -> G(ipv6,   O) end,
+            {ok, Domain} = socket:getopt(Sock, socket, domain),
+            {ok, Type}   = socket:getopt(Sock, socket, type),
+            {ok, Proto}  = socket:getopt(Sock, socket, protocol),
+            B2D          = GSO(bindtodevice),
+            RA           = GSO(reuseaddr),
+            RP           = GSO(reuseport),
+            OOBI         = GSO(oobinline),
+            RcvBuf       = GSO(rcvbuf),
+            RcvLW        = GSO(rcvlowat),
+            RcvTO        = GSO(rcvtimeo),
+            SndBuf       = GSO(sndbuf),
+            SndLW        = GSO(sndlowat),
+            SndTO        = GSO(sndtimeo),
+            Linger       = GSO(linger),
+            Timestamp    = GSO(timestamp),
+            FreeBind     = GIP4(freebind),
+            MTU          = GIP4(mtu),
+            MTUDisc      = GIP4(mtu_discover),
+            MALL         = GIP4(multicast_all),
+            MIF4         = GIP4(multicast_if),
+            MLoop4       = GIP4(multicast_loop),
+            MTTL         = GIP4(multicast_ttl),
+            NF           = GIP4(nodefrag), % raw only
+            PktInfo      = GIP4(pktinfo),  % dgram only
+            RecvErr4     = GIP4(recverr),
+            RecvIF       = GIP4(recvif),   % Only dgram and raw (and FreeBSD)
+            RecvOPTS     = GIP4(recvopts), % Not stream
+            RecvOrigDstAddr = GIP4(recvorigdstaddr),
+            RecvTOS      = GIP4(recvtos),
+            RecvTTL      = GIP4(recvttl),  % not stream
+            RetOpts      = GIP4(retopts),  % not stream
+            SendSrcAddr  = GIP4(sendsrcaddr),
+            TOS          = GIP4(tos),
+            Transparent  = GIP4(transparent),
+            TTL          = GIP4(ttl),
+            MHops        = GIP6(multicast_hops),
+            MIF6         = GIP6(multicast_if), % Only dgram and raw
+            MLoop6       = GIP6(multicast_loop),
+            RecvErr6     = GIP6(recverr),
+            RecvPktInfo  = GIP6(recvpktinfo),
+            RtHdr        = GIP6(rthdr),
+            AuthHdr      = GIP6(authhdr),
+            HopLimit     = GIP6(hoplimit),
+            HopOpts      = GIP6(hopopts),
+            DstOpts      = GIP6(dstopts),
+            FlowInfo     = GIP6(flowinfo),
+            UHops        = GIP6(unicast_hops),
+            i("got continue when: "
+              "~n   (socket) Domain:             ~p"
+              "~n   (socket) Type:               ~p"
+              "~n   (socket) Protocol:           ~p"
+              "~n   (socket) Reuse Address:      ~s"
+              "~n   (socket) Reuse Port:         ~s"
+              "~n   (socket) Bind To Device:     ~s"
+              "~n   (socket) OOBInline:          ~s"
+              "~n   (socket) RcvBuf:             ~s"
+              "~n   (socket) RcvLW:              ~s"
+              "~n   (socket) RcvTO:              ~s"
+              "~n   (socket) SndBuf:             ~s"
+              "~n   (socket) SndLW:              ~s"
+              "~n   (socket) SndTO:              ~s"
+              "~n   (socket) Linger:             ~s"
+              "~n   (socket) Timestamp:          ~s"
+              "~n   (ip)     FreeBind:           ~s"
+              "~n   (ip)     MTU:                ~s"
+              "~n   (ip)     MTU Discovery:      ~s"
+              "~n   (ip)     Multicast ALL:      ~s"
+              "~n   (ip)     Multicast IF:       ~s"
+              "~n   (ip)     Multicast Loop:     ~s"
+              "~n   (ip)     Multicast TTL:      ~s"
+              "~n   (ip)     Node Frag:          ~s"
+              "~n   (ip)     Pkt Info:           ~s"
+              "~n   (ip)     Recv Err:           ~s"
+              "~n   (ip)     Recv IF:            ~s"
+              "~n   (ip)     Recv OPTS:          ~s"
+              "~n   (ip)     Recv Orig Dst Addr: ~s"
+              "~n   (ip)     Recv TOS:           ~s"
+              "~n   (ip)     Recv TTL:           ~s"
+              "~n   (ip)     Ret Opts:           ~s"
+              "~n   (ip)     Send Src Addr:      ~s"
+              "~n   (ip)     TOS:                ~s"
+              "~n   (ip)     Transparent:        ~s"
+              "~n   (ip)     TTL:                ~s"
+              "~n   (ipv6)   Multicast Hops:     ~s"
+              "~n   (ipv6)   Multicast IF:       ~s"
+              "~n   (ipv6)   Multicast Loop:     ~s"
+              "~n   (ipv6)   Recv Err:           ~s"
+              "~n   (ipv6)   Recv Pkt Info:      ~s"
+              "~n   (ipv6)   RT Hdr:             ~s"
+              "~n   (ipv6)   Auth Hdr:           ~s"
+              "~n   (ipv6)   Hop Limit:          ~s"
+              "~n   (ipv6)   Hop Opts:           ~s"
+              "~n   (ipv6)   Dst Opts:           ~s"
+              "~n   (ipv6)   Flow Info:          ~s"
+              "~n   (ipv6)   Unicast Hops:       ~s",
+              [Domain, Type, Proto,
+               RA, RP, B2D, OOBI,
+               RcvBuf, RcvLW, RcvTO, SndBuf, SndLW, SndTO,
+               Linger, Timestamp,
+               FreeBind, MTU, MTUDisc, MALL, MIF4, MLoop4, MTTL,
+               NF, PktInfo,RecvErr4, 
+               RecvIF, RecvOPTS, RecvOrigDstAddr, RecvTOS, RecvTTL, RetOpts,
+               SendSrcAddr, TOS, Transparent, TTL,
+               MHops, MIF6, MLoop6, RecvErr6, RecvPktInfo,
+               RtHdr, AuthHdr, HopLimit, HopOpts, DstOpts, FlowInfo,
+               UHops]),
+
+            %% ok = socket:setopt(Sock, otp, debug, true),
+            %% case socket:getopt(Sock, 0, {13, int}) of
+            %%     {ok, Val} ->
+            %%         i("PktOpts ok:  ~p", [Val]);
+            %%     {error, Reason} ->
+            %%         e("PktOpts err: ~p", [Reason])
+            %% end,
+            %% ok = socket:setopt(Sock, otp, debug, false),
+            SSO = fun(O, V) -> soso(Sock, O, V) end,
+            SIP4 = 
+                fun(O, V) ->
+                        if 
+                            (Type =:= dgram) -> 
+                                ok = soip(Sock, O,  V);
+                            true ->
+                                ok
+                        end
+                end,
+            SSO(timestamp, true),
+            SIP4(pktinfo, true),
+            ok = soip(Sock, recvtos,  true),
+            SIP4(recvttl,  true),
+            ok = soip(Sock, recvorigdstaddr,  true),
+
+            handler_loop(#handler{msg     = Msg,
+                                  peek    = Peek,
+                                  manager = Manager,
+                                  type    = Type,
+                                  socket  = Sock})
+    end.
+
+so(Sock, Lvl, Opt, Val) ->
+    ok = socket:setopt(Sock, Lvl, Opt, Val).
+
+soso(Sock, Opt, Val) ->
+    so(Sock, socket, Opt, Val).
+
+soip(Sock, Opt, Val) ->
+    so(Sock, ip, Opt, Val).
+
+%% soipv6(Sock, Opt, Val) ->
+%%     so(Sock, ipv6, Opt, Val).
+
+handler_loop(H) ->
+    i("try read message"),
+    case recv(H) of
+        {ok, {Source, Msg}} ->
+            i("received ~w bytes of data~s", 
+              [size(Msg), case Source of
+                              undefined -> "";
+                              _ -> f(" from:~n   ~p", [Source])
+                          end]),
+            case ?LIB:dec_msg(Msg) of
+                {request, N, Req} ->
+                    i("received request ~w: "
+                      "~n   ~p", [N, Req]),
+                    Reply = ?LIB:enc_rep_msg(N, "hoppsan"),
+                    case send(H, Reply, Source) of
+                        ok ->
+                            i("successfully sent reply ~w", [N]),
+                            handler_loop(H);
+                        {error, SReason} ->
+                            e("failed sending reply ~w:"
+                              "~n   ~p", [N, SReason]),
+                            exit({failed_sending_reply, SReason})
+                    end
+            end;
+
+        {error, closed} ->
+            i("closed when"
+              "~n   ~p", [socket:info()]),
+            exit(normal);
+        
+        {error, RReason} ->
+            e("failed reading request: "
+              "~n   ~p", [RReason]),
+            exit({failed_reading_request, RReason})
+    end.
+
+
+recv(#handler{peek = true, socket = Sock, type = stream}) ->
+    peek_recv(Sock);
+recv(#handler{socket = Sock, msg = true, type = stream}) ->
+    case socket:recvmsg(Sock) of
+        {ok, #{addr  := undefined = Source,
+               iov   := [Data],
+               ctrl  := CMsgHdrs,
+               flags := Flags}} ->
+            i("received message: "
+              "~n   CMsgHdrs: ~p"
+              "~n   Flags:    ~p", [CMsgHdrs, Flags]),
+            {ok, {Source, Data}};
+        {ok, X} ->
+            e("received *unexpected* message: "
+              "~n   ~p", [X]),
+            {error, {unexpected, X}};
+        {error, _} = ERROR ->
+            ERROR
+    end;
+recv(#handler{socket = Sock, msg = true, type = dgram}) ->
+    case socket:recvmsg(Sock) of
+        {ok, #{addr  := Source,
+               iov   := [Data],
+               ctrl  := CMsgHdrs,
+               flags := Flags}} ->
+            i("received message: "
+              "~n   CMsgHdrs: ~p"
+              "~n   Flags:    ~p", [CMsgHdrs, Flags]),
+            {ok, {Source, Data}};
+        {ok, X} ->
+            {error, {unexpected, X}};
+        {error, _} = ERROR ->
+            ERROR
+    end;
+recv(#handler{peek = false, socket = Sock, type = stream}) ->
+    do_recv(Sock);
+recv(#handler{peek = Peek, socket = Sock, type = dgram})
+  when (Peek =:= true) ->
+    %% ok  = socket:setopt(Sock, otp, debug, true),
+    RES = peek_recvfrom(Sock, 5),
+    %% ok  = socket:setopt(Sock, otp, debug, false),
+    RES;
+recv(#handler{peek = Peek, socket = Sock, type = dgram})
+  when (Peek =:= false) ->
+    %% ok = socket:setopt(Sock, otp, debug, true),
+    socket:recvfrom(Sock).
+
+do_recv(Sock) ->
+    case socket:recv(Sock) of
+        {ok, Msg} ->
+            {ok, {undefined, Msg}};
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+peek_recv(Sock) ->
+    i("try peek on the message type (expect request)"),
+    Type = ?LIB:req(),
+    case socket:recv(Sock, 4, [peek]) of
+        {ok, <<Type:32>>} ->
+            i("was request - do proper recv"),
+            do_recv(Sock);
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+peek_recvfrom(Sock, BufSz) ->
+    i("try peek recvfrom with buffer size ~w", [BufSz]),
+    case socket:recvfrom(Sock, BufSz, [peek]) of
+        {ok, {_Source, Msg}} when (BufSz =:= size(Msg)) ->
+            %% i("we filled the buffer: "
+            %%   "~n   ~p", [Msg]),
+            %% It *may not* fit => try again with double size
+            peek_recvfrom(Sock, BufSz*2);
+        {ok, _} ->
+            %% It fits => read for real
+            i("we did *not* fill the buffer - do the 'real' read"),
+            socket:recvfrom(Sock);
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+
+send(#handler{socket = Sock, msg = true, type = stream, stimeout = Timeout}, 
+     Msg, _) ->
+    CMsgHdr  = #{level => ip, type => tos, data => reliability},
+    CMsgHdrs = [CMsgHdr],
+    MsgHdr   = #{iov => [Msg], ctrl => CMsgHdrs},
+    %% socket:setopt(Sock, otp, debug, true),
+    Res = socket:sendmsg(Sock, MsgHdr, Timeout),
+    %% socket:setopt(Sock, otp, debug, false),
+    Res;
+send(#handler{socket = Sock, type = stream, stimeout = Timeout}, Msg, _) ->
+    socket:send(Sock, Msg, Timeout);
+send(#handler{socket = Sock, msg = true, type = dgram, stimeout = Timeout}, 
+     Msg, Dest) ->
+    CMsgHdr  = #{level => ip, type => tos, data => reliability},
+    CMsgHdrs = [CMsgHdr],
+    MsgHdr   = #{addr => Dest,
+                 ctrl => CMsgHdrs,
+                 iov  => [Msg]},
+    %% ok = socket:setopt(Sock, otp, debug, true),
+    Res = socket:sendmsg(Sock, MsgHdr, Timeout),
+    %% ok = socket:setopt(Sock, otp, debug, false),
+    Res;
+send(#handler{socket = Sock, type = dgram, stimeout = Timeout}, Msg, Dest) ->
+    socket:sendto(Sock, Msg, Dest, Timeout).
+
+%% filler() ->
+%%     list_to_binary(lists:duplicate(2048, " FILLER ")).
+
+
+
+%% =========================================================================
+
+f(F, A) ->
+    ?LIB:f(F, A).
+
+e(F) ->
+    e(F, []).
+e(F, A) ->
+    ?LIB:e(F, A).
+
+i(F) ->
+    ?LIB:i(F).
+
+i(F, A) ->
+    ?LIB:i(F, A).
+
diff --git a/erts/emulator/test/esock_ttest/.gitignore b/erts/emulator/test/esock_ttest/.gitignore
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/erts/emulator/test/esock_ttest/.gitignore
diff --git a/erts/emulator/test/esock_ttest/esock-ttest b/erts/emulator/test/esock_ttest/esock-ttest
new file mode 100755
index 0000000000..2ded557484
--- /dev/null
+++ b/erts/emulator/test/esock_ttest/esock-ttest
@@ -0,0 +1,382 @@
+#!/usr/bin/env escript
+
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+%% ==========================================================================
+%%
+%% This is a simple wrapper escript on top of the socket ttest program(s).
+%% The idea is to make it simple to run in a normal shell (bash).
+%%
+%% ==========================================================================
+
+-define(SECS(I), timer:seconds(I)).
+
+-define(CLIENT_MSG_1_MAX_OUTSTANDING, 100).
+-define(CLIENT_MSG_2_MAX_OUTSTANDING,  10).
+-define(CLIENT_MSG_3_MAX_OUTSTANDING,   1).
+
+main(Args) ->
+    State = process_args(Args),
+    exec(State),
+    ok.
+
+usage(ErrorString) when is_list(ErrorString) ->
+    eprint(ErrorString),
+    usage(),
+    erlang:halt(0).
+
+usage() ->
+    io:format("usage: ~s [options]"
+              "~n"
+              "~n   This erlang script is used to start the (e)socket ttest "
+              "~n   units (server or client)."
+              "~n"
+              "~n   options: "
+              "~n     --help                       Display this info and exit. "
+              "~n     --server [server-options]    Start a server. "
+              "~n                                  There are no mandatory server options."
+              "~n     --client client-options      Start a client"
+              "~n                                  Some client options are mandatory and"
+              "~n                                  others optional."
+              "~n     --domain <domain>            local | inet | inet6"
+              "~n                                  Which domain to use."
+              "~n                                  Only valid for server."
+              "~n                                  Defaults to: inet"
+              "~n     --async                      Asynchronous mode (Timeout = nowait)"
+              "~n                                  This option is only valid for transport = sock."
+              "~n                                  Also, its only used when active =/= false."
+              "~n     --active <active>            boolean() | once."
+              "~n                                  Valid for both client and server."
+              "~n                                  Defaults to: false"
+              "~n     --transport <transport>      Which transport to use: gen|sock[:plain|msg]"
+              "~n                                     gen:  gen_tcp"
+              "~n                                     sock: socket"
+              "~n                                          plain: recv/send (default)"
+              "~n                                          msg:   recvmsg/sendmsg"
+              "~n                                  Defaults to: sock:plain"
+              "~n     --scon <addr>:<port>|<path>  Server info."
+              "~n                                  The address part is in the standard form:"
+              "~n                                       \"a.b.c.d\"."
+              "~n                                  <path> is used for Unix Domain sockets (local)."
+              "~n                                  Only valid, and mandatory, for client."
+              "~n     --msg-id <1|2|3>             Choose which message to use during the test."
+              "~n                                  Basically: "
+              "~n                                     1: small"
+              "~n                                     2: medium"
+              "~n                                     3: large"
+              "~n                                  Defaults to: 1"
+              "~n     --max-outstanding <Num>      How many messages to send before waiting for"
+              "~n                                  a reply."
+              "~n                                  Valid only for client."
+              "~n                                  Defaults to: "
+              "~n                                     MsgID 1: 100"
+              "~n                                     MsgID 2:  10"
+              "~n                                     MsgID 3:   1"
+              "~n     --runtime <Time>             Time of the test in seconds."
+              "~n                                  Only valid for client."
+              "~n                                  Mandatory."
+              "~n                                  Defaults to: 60 (seconds)"
+              "~n"
+              "~n"
+              "~n", 
+              [scriptname()]),
+    ok.
+
+process_args(["--help"|_]) ->
+    usage();
+process_args(["--server"|ServerArgs]) ->
+    process_server_args(ServerArgs);
+process_args(["--client"|ClientArgs]) ->
+    process_client_args(ClientArgs);
+process_args(Args) ->
+    usage(f("Invalid Args: "
+            "~n   ~p", [Args])).
+
+
+process_server_args(Args) ->
+    Defaults = #{role      => server,
+                 domain    => inet,
+                 async     => false,
+                 active    => false,
+                 transport => {sock, plain}},
+    process_server_args(Args, Defaults).
+
+process_server_args([], State) ->
+    State;
+
+process_server_args(["--domain", Domain|Args], State) 
+  when ((Domain =:= "local") orelse
+        (Domain =:= "inet") orelse
+        (Domain =:= "inet6")) ->
+    process_server_args(Args, State#{domain => list_to_atom(Domain)});
+
+process_server_args(["--async"|Args], State) ->
+    process_server_args(Args, State#{async => true});
+
+process_server_args(["--active", Active|Args], State) 
+  when ((Active =:= "false") orelse
+        (Active =:= "once") orelse
+        (Active =:= "true")) ->
+    process_server_args(Args, State#{active => list_to_atom(Active)});
+
+process_server_args(["--transport", "gen" | Args], State) ->
+    process_server_args(Args, State#{transport => gen});
+process_server_args(["--transport", "sock" | Args], State) ->
+    process_server_args(Args, State#{transport => {sock, plain}});
+process_server_args(["--transport", "sock:plain" | Args], State) ->
+    process_server_args(Args, State#{transport => {sock, plain}});
+process_server_args(["--transport", "sock:msg" | Args], State) ->
+    process_server_args(Args, State#{transport => {sock, msg}});
+
+process_server_args([Arg|_], _State) ->
+    usage(f("Invalid Server arg: ~s", [Arg])).
+
+
+process_client_args(Args) ->
+    Defaults = #{role            => client,
+                 async           => false,
+                 active          => false,
+                 transport       => {sock, plain},
+                 %% Will cause error if not provided
+                 %% Should be "addr:port or string()
+                 server          => undefined,
+                 msg_id          => 1,
+                 %% Will be filled in based on msg_id if not provided
+                 max_outstanding => undefined,
+                 runtime         => ?SECS(60)},
+    process_client_args(Args, Defaults).
+
+process_client_args([], State) ->
+    process_client_args_ensure_max_outstanding(State);
+
+process_client_args(["--async"|Args], State) ->
+    process_client_args(Args, State#{async => true});
+
+process_client_args(["--active", Active|Args], State) 
+  when (Active =:= "false") orelse
+       (Active =:= "once") orelse
+       (Active =:= "true") ->
+    process_client_args(Args, State#{active => list_to_atom(Active)});
+
+process_client_args(["--transport", "gen" | Args], State) ->
+    process_client_args(Args, State#{transport => gen});
+process_client_args(["--transport", "sock" | Args], State) ->
+    process_client_args(Args, State#{transport => {sock, plain}});
+process_client_args(["--transport", "sock:plain" | Args], State) ->
+    process_client_args(Args, State#{transport => {sock, plain}});
+process_client_args(["--transport", "sock:msg" | Args], State) ->
+    process_client_args(Args, State#{transport => {sock, msg}});
+
+process_client_args(["--msg-id", MsgID|Args], State)
+  when ((MsgID =:= "1") orelse
+        (MsgID =:= "2") orelse
+        (MsgID =:= "3")) ->
+    process_client_args(Args, State#{msg_id => list_to_integer(MsgID)});
+
+process_client_args(["--max-outstanding", Max|Args], State) ->
+    try list_to_integer(Max) of
+        I when (I > 0) ->
+            process_client_args(Args, State#{max_outstanding => I});
+        _ ->
+            usage(f("Invalid Max Outstanding: ~s", [Max]))
+    catch
+        _:_:_ ->
+            usage(f("Invalid Max Outstanding: ~s", [Max]))
+    end;
+
+process_client_args(["--scon", Server|Args], State) ->
+    case string:split(Server, ":", trailing) of
+        [AddrStr,PortStr] ->
+            Addr = case inet:parse_address(AddrStr) of
+                       {ok, A} ->
+                           A;
+                       {error, _} ->
+                           usage(f("Invalid Server Address: ~s", [AddrStr]))
+                   end,
+            Port = try list_to_integer(PortStr) of
+                       I when (I > 0) ->
+                           I;
+                       _ ->
+                           usage(f("Invalid Server Port: ~s", [PortStr]))
+                   catch
+                       _:_:_ ->
+                           usage(f("Invalid Server Port: ~s", [PortStr]))
+                   end,
+            process_client_args(Args, State#{server => {Addr, Port}});
+        [Path] ->
+            process_client_args(Args, State#{server => Path});
+        _ ->
+            usage(f("Invalid Server: ~s", [Server]))
+    end;
+
+process_client_args(["--runtime", T|Args], State) ->
+    try list_to_integer(T) of
+        I when (I > 0) ->
+            process_client_args(Args, State#{runtime => ?SECS(I)});
+        _ ->
+            usage(f("Invalid Run Time: ~s", [T]))
+    catch
+        _:_:_ ->
+            usage(f("Invalid Run Time: ~s", [T]))
+    end;
+
+process_client_args([Arg|_], _State) ->
+    usage(f("Invalid Client arg: ~s", [Arg])).
+
+
+process_client_args_ensure_max_outstanding(
+  #{msg_id          := 1,
+    max_outstanding := undefined} = State) ->
+    State#{max_outstanding => ?CLIENT_MSG_1_MAX_OUTSTANDING};
+process_client_args_ensure_max_outstanding(
+  #{msg_id          := 2,
+    max_outstanding := undefined} = State) ->
+    State#{max_outstanding => ?CLIENT_MSG_2_MAX_OUTSTANDING};
+process_client_args_ensure_max_outstanding(
+  #{msg_id          := 3,
+    max_outstanding := undefined} = State) ->
+    State#{max_outstanding => ?CLIENT_MSG_3_MAX_OUTSTANDING};
+process_client_args_ensure_max_outstanding(
+  #{msg_id          := MsgID,
+    max_outstanding := MaxOutstanding} = State)
+  when ((MsgID =:= 1) orelse
+        (MsgID =:= 2) orelse
+        (MsgID =:= 3)) andalso 
+       (is_integer(MaxOutstanding) andalso (MaxOutstanding > 0)) ->
+    State;
+process_client_args_ensure_max_outstanding(
+  #{msg_id          := MsgID,
+    max_outstanding := MaxOutstanding}) ->
+    usage(f("Invalid Msg ID (~w) and Max Outstanding (~w)", 
+            [MsgID, MaxOutstanding])).
+
+
+
+%% ==========================================================================
+
+exec(#{role      := server,
+       domain    := Domain,
+       active    := Active,
+       transport := gen})
+  when (Domain =:= inet) orelse (Domain =:= inet6) ->
+    case socket_test_ttest_tcp_server_gen:start(Domain, Active) of
+        {ok, {Pid, _}} ->
+            MRef = erlang:monitor(process, Pid),
+            receive
+                {'DOWN', MRef, process, Pid, Info} ->
+                    Info
+            end;
+        {error, Reason} ->
+            eprint(f("Failed starting server: "
+                     "~n   ~p", [Reason])),
+            error
+    end;
+exec(#{role      := server,
+       domain    := Domain,
+       async     := Async,
+       active    := Active,
+       transport := {sock, Method}}) ->
+    case socket_test_ttest_tcp_server_socket:start(Method, Domain, Async, Active) of
+        {ok, {Pid, _}} ->
+            MRef = erlang:monitor(process, Pid),
+            receive
+                {'DOWN', MRef, process, Pid, Info} ->
+                    Info
+            end;
+        {error, Reason} ->
+            eprint(f("Failed starting server: "
+                     "~n   ~p", [Reason])),
+            error
+    end;
+
+exec(#{role   := client,
+       server := undefined}) ->
+    usage("Mandatory option 'server' not provided");
+exec(#{role            := client,
+       server          := {_Addr, _Port} = ServerInfo,
+       active          := Active,
+       transport       := gen,
+       msg_id          := MsgID,
+       max_outstanding := MaxOutstanding,
+       runtime         := RunTime}) ->
+    case socket_test_ttest_tcp_client_gen:start(true,
+                                                ServerInfo,
+                                                Active,
+                                                MsgID, MaxOutstanding,
+                                                RunTime) of
+        {ok, Pid} ->
+            MRef = erlang:monitor(process, Pid),
+            receive
+                {'DOWN', MRef, process, Pid, Info} ->
+                    Info
+            end;
+        {error, Reason} ->
+            eprint(f("Failed starting server: "
+                     "~n   ~p", [Reason])),
+            error
+    end;
+exec(#{role            := client,
+       server          := ServerInfo,
+       async           := Async,
+       active          := Active,
+       transport       := {sock, Method},
+       msg_id          := MsgID,
+       max_outstanding := MaxOutstanding,
+       runtime         := RunTime}) ->
+    case socket_test_ttest_tcp_client_socket:start(true,
+                                                   Async,
+						   Active,
+                                                   Method,
+                                                   ServerInfo,
+                                                   MsgID, MaxOutstanding,
+                                                   RunTime) of
+        {ok, Pid} ->
+            MRef = erlang:monitor(process, Pid),
+            receive
+                {'DOWN', MRef, process, Pid, Info} ->
+                    Info
+            end;
+        {error, Reason} ->
+            eprint(f("Failed starting server: "
+                     "~n   ~p", [Reason])),
+            error
+    end;
+exec(_) ->
+    usage("Unexpected option combo"),
+    ok.
+
+
+
+%% ==========================================================================
+    
+f(F, A) ->
+    socket_test_ttest_lib:format(F, A).
+
+eprint(ErrorString) when is_list(ErrorString) ->
+    print("<ERROR> " ++ ErrorString ++ "~n", []).
+
+print(F, A) ->
+    io:format(F ++ "~n", A).
+
+scriptname() ->
+    FullName = escript:script_name(),
+    filename:basename(FullName).
+
diff --git a/erts/emulator/test/esock_ttest/esock-ttest-client b/erts/emulator/test/esock_ttest/esock-ttest-client
new file mode 100755
index 0000000000..5ae05d03b8
--- /dev/null
+++ b/erts/emulator/test/esock_ttest/esock-ttest-client
@@ -0,0 +1,92 @@
+#!/bin/sh
+
+# 
+#  %CopyrightBegin%
+#  
+#  Copyright Ericsson AB 2019-2019. All Rights Reserved.
+#  
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+# 
+#      http://www.apache.org/licenses/LICENSE-2.0
+# 
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#  
+#  %CopyrightEnd%
+# 
+
+#
+# This is just a simple convenience wrapper to the esock-ttest.
+# That means that there are some options not available here.
+#
+
+EMU=$ERL_TOP/erts/emulator
+EMU_TEST=$EMU/test
+ESOCK_TTEST=$EMU_TEST/esock_ttest
+
+RUNTIME=30
+# RUNTIME=60
+# RUNTIME=600
+
+if [ $# = 3 ]; then
+    MSGID=$1
+    SERVER_INFO=$2:$3
+
+    ITERATIONS="\
+       gen  false $MSGID
+       gen  true  $MSGID
+       gen  once  $MSGID
+       sock false $MSGID --async
+       sock true  $MSGID --async
+       sock once  $MSGID --async"
+
+else
+    if [ $# = 2 ]; then
+	MSGID=$1
+	SERVER_INFO=$2
+
+	ITERATIONS="\
+           sock false $MSGID --async
+           sock true  $MSGID --async
+           sock once  $MSGID --async"
+
+    else
+	echo "Invalid number of args"
+	exit 1;
+    fi
+fi
+
+
+# ---------------------------------------------------------------------------
+
+# For when we have figured out how to configure local for gen_tcp...
+
+#ITERATIONS="\
+#   gen  false  $MSGID
+#   gen  true   $MSGID
+#   gen  once   $MSGID
+#   sock false  $MSGID
+#   sock true   $MSGID
+#   sock once   $MSGID"
+
+# ---------------------------------------------------------------------------
+
+echo "$ITERATIONS" |
+  while read TRANSPORT ACTIVE MSG_ID ASYNC; do
+
+      echo ""
+      echo "=========== transport = $TRANSPORT, active = $ACTIVE, msg-id = $MSG_ID ==========="
+      # The /dev/null at the end is necessary because erlang "does things" with stdin
+      # and this case would cause the 'while read' to "fail" so that we only would
+      # loop one time
+      $ESOCK_TTEST/esock-ttest --client --transport $TRANSPORT $ASYNC --active $ACTIVE --msg-id $MSG_ID --scon $SERVER_INFO --runtime $RUNTIME </dev/null
+      echo ""
+
+  done
+
+
diff --git a/erts/emulator/test/esock_ttest/esock-ttest-server-gen b/erts/emulator/test/esock_ttest/esock-ttest-server-gen
new file mode 100755
index 0000000000..c29184772e
--- /dev/null
+++ b/erts/emulator/test/esock_ttest/esock-ttest-server-gen
@@ -0,0 +1,32 @@
+#!/bin/sh
+
+# 
+#  %CopyrightBegin%
+#  
+#  Copyright Ericsson AB 2019-2019. All Rights Reserved.
+#  
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+# 
+#      http://www.apache.org/licenses/LICENSE-2.0
+# 
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#  
+#  %CopyrightEnd%
+# 
+
+EMU=$ERL_TOP/erts/emulator
+EMU_TEST=$EMU/test
+ESOCK_TTEST=$EMU_TEST/esock_ttest
+
+if [ $# = 1 ]; then
+    ACTIVE="--active $1"
+fi
+
+$ESOCK_TTEST/esock-ttest --server --transport gen $ACTIVE
+
diff --git a/erts/emulator/test/esock_ttest/esock-ttest-server-sock b/erts/emulator/test/esock_ttest/esock-ttest-server-sock
new file mode 100755
index 0000000000..c443d42e64
--- /dev/null
+++ b/erts/emulator/test/esock_ttest/esock-ttest-server-sock
@@ -0,0 +1,56 @@
+#!/bin/sh
+
+# 
+#  %CopyrightBegin%
+#  
+#  Copyright Ericsson AB 2019-2019. All Rights Reserved.
+#  
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+# 
+#      http://www.apache.org/licenses/LICENSE-2.0
+# 
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#  
+#  %CopyrightEnd%
+# 
+
+EMU=$ERL_TOP/erts/emulator
+EMU_TEST=$EMU/test
+ESOCK_TTEST=$EMU_TEST/esock_ttest
+
+#  $1 - async  - boolean()
+#  $2 - active - once | boolean()
+# [$3 - domain - inet (default) | inet6 | local]
+if [ $# -ge 2 ]; then
+
+    async=$1
+    active=$2
+
+    if [ $async = true ]; then
+	ASYNC="--async"
+    else
+	ASYNC=
+    fi
+
+    ACTIVE="--active $active"
+
+    if [ $# = 3 ]; then
+	DOMAIN="--domain $3"
+    fi
+
+
+else
+    echo "<ERROR> Missing args: async and active"
+    echo ""
+    exit 1
+fi
+
+
+$ESOCK_TTEST/esock-ttest --server $DOMAIN $ASYNC --transport sock $ACTIVE
+
diff --git a/erts/emulator/test/exception_SUITE.erl b/erts/emulator/test/exception_SUITE.erl
index aec66cb9a3..154bce3c35 100644
--- a/erts/emulator/test/exception_SUITE.erl
+++ b/erts/emulator/test/exception_SUITE.erl
@@ -23,6 +23,7 @@
 -export([all/0, suite/0,
          badmatch/1, pending_errors/1, nil_arith/1, top_of_stacktrace/1,
          stacktrace/1, nested_stacktrace/1, raise/1, gunilla/1, per/1,
+         change_exception_class/1,
          exception_with_heap_frag/1, backtrace_depth/1,
          line_numbers/1]).
 
@@ -36,6 +37,11 @@
 %% during compilation instead of at runtime, so do not perform this analysis.
 -compile([{hipe, [no_icode_range]}]).
 
+%% Module-level type optimization propagates the constants used when testing
+%% increment1/1 and increment2/1, which makes it test something completely
+%% different, so we're turning it off.
+-compile(no_module_opt).
+
 suite() ->
     [{ct_hooks,[ts_install_cth]},
      {timetrap, {minutes, 1}}].
@@ -43,6 +49,7 @@ suite() ->
 all() -> 
     [badmatch, pending_errors, nil_arith, top_of_stacktrace,
      stacktrace, nested_stacktrace, raise, gunilla, per,
+     change_exception_class,
      exception_with_heap_frag, backtrace_depth, line_numbers].
 
 -define(try_match(E),
@@ -507,6 +514,38 @@ t1(_,X,_) ->
 t2(_,X,_) ->
     (X bsl 1) + 1.
 
+change_exception_class(_Config) ->
+    try
+        change_exception_class_1(fun() -> throw(arne) end)
+    catch
+        error:arne ->
+            ok;
+        Class:arne ->
+            ct:fail({wrong_exception_class,Class})
+    end.
+
+change_exception_class_1(F) ->
+    try
+        change_exception_class_2(F)
+    after
+        %% The exception would be caught and rethrown using
+        %% an i_raise instruction. Before the correction
+        %% of the raw_raise instruction, the change of class
+        %% would not stick.
+        io:put_chars("Exception automatically rethrown here\n")
+    end.
+
+change_exception_class_2(F) ->
+    try
+        F()
+    catch
+        throw:Reason:Stack ->
+            %% Translated to a raw_raise instruction.
+            %% The change of exception class would not stick
+            %% if the i_raise instruction was later executed.
+            erlang:raise(error, Reason, Stack)
+    end.
+
 %%
 %% Make sure that even if a BIF builds an heap fragment, then causes an exception,
 %% the stacktrace term will still be OK (specifically, that it does not contain
diff --git a/erts/emulator/test/fun_SUITE.erl b/erts/emulator/test/fun_SUITE.erl
index 73fe9b0d8f..ad8ef0feff 100644
--- a/erts/emulator/test/fun_SUITE.erl
+++ b/erts/emulator/test/fun_SUITE.erl
@@ -27,7 +27,7 @@
 	 fun_to_port/1,t_phash/1,t_phash2/1,md5/1,
 	 refc/1,refc_ets/1,refc_dist/1,
 	 const_propagation/1,t_arity/1,t_is_function2/1,
-	 t_fun_info/1,t_fun_info_mfa/1]).
+	 t_fun_info/1,t_fun_info_mfa/1,t_fun_to_list/1]).
 
 -export([nothing/0]).
 
@@ -44,7 +44,7 @@ all() ->
      equality, ordering, fun_to_port, t_phash,
      t_phash2, md5, refc, refc_ets, refc_dist,
      const_propagation, t_arity, t_is_function2, t_fun_info,
-     t_fun_info_mfa].
+     t_fun_info_mfa,t_fun_to_list].
 
 %% Test that the correct EXIT code is returned for all types of bad funs.
 bad_apply(Config) when is_list(Config) ->
@@ -513,6 +513,8 @@ refc(Config) when is_list(Config) ->
 	Other -> ct:fail({unexpected,Other})
     end,
     process_flag(trap_exit, false),
+    %% Wait to make sure that the process has terminated completely.
+    receive after 1 -> ok end,
     {refc,3} = erlang:fun_info(F1, refc),
 
     %% Garbage collect. Only the F2 fun will be left.
@@ -576,7 +578,7 @@ refc_dist(Config) when is_list(Config) ->
     process_flag(trap_exit, true),
     Pid = spawn_link(Node, fun() -> receive
                                         Fun when is_function(Fun) ->
-                                            2 = fun_refc(Fun),
+                                            3 = fun_refc(Fun),
                                             exit({normal,Fun}) end
                            end),
     F = fun() -> 42 end,
@@ -592,13 +594,14 @@ refc_dist(Config) when is_list(Config) ->
     3 = fun_refc(F2),
     true = erlang:garbage_collect(),
     2 = fun_refc(F),
-    refc_dist_send(Node, F).
+    refc_dist_send(Node, F),
+    test_server:stop_node(Node).
 
 refc_dist_send(Node, F) ->
     Pid = spawn_link(Node, fun() -> receive
                                         {To,Fun} when is_function(Fun) ->
                                             wait_until(fun () ->
-                                                               2 =:= fun_refc(Fun)
+                                                               3 =:= fun_refc(Fun)
                                                        end),
                                             To ! Fun
                                     end
@@ -626,7 +629,7 @@ refc_dist_reg_send(Node, F) ->
                                    Me ! Ref,
                                    receive
                                        {Me,Fun} when is_function(Fun) ->
-                                           2 = fun_refc(Fun),
+                                           3 = fun_refc(Fun),
                                            Me ! Fun
                                    end
                            end),
@@ -682,6 +685,7 @@ t_arity(Config) when is_list(Config) ->
     43 = spawn_call(Node, fun(X, Y) -> A+X+Y end),
     1 = spawn_call(Node, fun(X, Y) -> X+Y end),
     45 = spawn_call(Node, fun(X, Y, Z) -> A+X+Y+Z end),
+    test_server:stop_node(Node),
     ok.
 
 t_is_function2(Config) when is_list(Config) ->
@@ -710,6 +714,16 @@ t_is_function2(Config) when is_list(Config) ->
     bad_arity({}),
     bad_arity({a,b}),
     bad_arity(self()),
+
+    %% Bad arity argument in guard test.
+    Fun = fun erlang:abs/1,
+    ok = if
+             is_function(Fun, -1) -> error;
+             is_function(Fun, 256) -> error;
+             is_function(Fun, a) -> error;
+             is_function(Fun, Fun) -> error;
+             true -> ok
+         end,
     ok.
 
 bad_arity(A) ->
@@ -788,6 +802,12 @@ t_fun_info_mfa(Config) when is_list(Config) ->
     {'EXIT',_} = (catch erlang:fun_info_mfa(id(d))),
     ok.
 
+t_fun_to_list(Config) when is_list(Config) ->
+    "fun a:b/1" = erlang:fun_to_list(fun a:b/1),
+    "fun 'a-esc':'b-esc'/1" = erlang:fun_to_list(fun 'a-esc':'b-esc'/1),
+    "fun 'a-esc':b/1" = erlang:fun_to_list(fun 'a-esc':b/1),
+    "fun a:'b-esc'/1" = erlang:fun_to_list(fun a:'b-esc'/1),
+    ok.
 
 bad_info(Term) ->
     try	erlang:fun_info(Term, module) of
@@ -806,11 +826,13 @@ verify_not_undef(Fun, Tag) ->
 	    ct:fail("tag ~w not defined in fun_info", [Tag]);
 	{Tag,_} -> ok
     end.
-	    
+
 id(X) ->
     X.
 
 spawn_call(Node, AFun) ->
+    Parent = self(),
+    Init = erlang:whereis(init),
     Pid = spawn_link(Node,
 		     fun() ->
 			     receive
@@ -821,8 +843,10 @@ spawn_call(Node, AFun) ->
 						_ -> lists:seq(0, Arity-1)
 					    end,
 				     Res = apply(Fun, Args),
-				     {pid,Creator} = erlang:fun_info(Fun, pid),
-				     Creator ! {result,Res}
+                     case erlang:fun_info(Fun, pid) of
+                        {pid,Init} -> Parent ! {result,Res};
+                        {pid,Creator} -> Creator ! {result,Res}
+                     end
 			     end
 		     end),
     Pid ! {AFun,AFun,AFun},
diff --git a/erts/emulator/test/lcnt_SUITE.erl b/erts/emulator/test/lcnt_SUITE.erl
index 87b97037d6..2dbaec9942 100644
--- a/erts/emulator/test/lcnt_SUITE.erl
+++ b/erts/emulator/test/lcnt_SUITE.erl
@@ -187,5 +187,8 @@ remove_untoggleable_locks([]) ->
     [];
 remove_untoggleable_locks([{resource_monitors, _, _, _} | T]) ->
     remove_untoggleable_locks(T);
+remove_untoggleable_locks([{'socket[gcnt]', _, _, _} | T]) ->
+    %% Global lock used by socket NIF
+    remove_untoggleable_locks(T);
 remove_untoggleable_locks([H | T]) ->
     [H | remove_untoggleable_locks(T)].
diff --git a/erts/emulator/test/map_SUITE.erl b/erts/emulator/test/map_SUITE.erl
index d0a6763fe5..9ea59e1084 100644
--- a/erts/emulator/test/map_SUITE.erl
+++ b/erts/emulator/test/map_SUITE.erl
@@ -17,7 +17,7 @@
 %% %CopyrightEnd%
 %%
 -module(map_SUITE).
--export([all/0, suite/0]).
+-export([all/0, suite/0, init_per_suite/1, end_per_suite/1]).
 
 -export([t_build_and_match_literals/1, t_build_and_match_literals_large/1,
          t_update_literals/1, t_update_literals_large/1,
@@ -84,7 +84,10 @@
          %% instruction-level tests
          t_has_map_fields/1,
          y_regs/1,
-         badmap_17/1]).
+         badmap_17/1,
+
+         %%Bugs
+         t_large_unequal_bins_same_hash_bug/1]).
 
 -include_lib("stdlib/include/ms_transform.hrl").
 
@@ -149,7 +152,26 @@ all() -> [t_build_and_match_literals, t_build_and_match_literals_large,
           %% instruction-level tests
           t_has_map_fields,
           y_regs,
-          badmap_17].
+          badmap_17,
+
+          %% Bugs
+          t_large_unequal_bins_same_hash_bug].
+
+init_per_suite(Config) ->
+    A0 = case application:start(sasl) of
+	     ok -> [sasl];
+	     _ -> []
+	 end,
+    A = case application:start(os_mon) of
+	     ok -> [os_mon|A0];
+	     _ -> A0
+	 end,
+    [{started_apps, A}|Config].
+
+end_per_suite(Config) ->
+    As = proplists:get_value(started_apps, Config),
+    lists:foreach(fun (A) -> application:stop(A) end, As),
+    Config.
 
 %% tests
 
@@ -3374,3 +3396,67 @@ fannerl() ->
       104,2,97,9,97,16,70,63,184,100,97,32,0,0,0,104,2,97,10,97,16,70,63,169,174,
       254,64,0,0,0,104,2,97,11,97,16,70,191,119,121,234,0,0,0,0,104,2,97,12,97,
       16,70,63,149,12,170,128,0,0,0,104,2,97,13,97,16,70,191,144,193,191,0,0,0,0>>.
+
+%% This test case checks that the bug with ticket number OTP-15707 is
+%% fixed. The bug could cause a crash or memory usage to grow until
+%% the machine ran out of memory.
+t_large_unequal_bins_same_hash_bug(Config) when is_list(Config) ->
+    run_when_enough_resources(
+      fun() ->
+              K1 = get_4GB_bin(1),
+              K2 = get_4GB_bin(2),
+              Map = make_map(500),
+              Map2 = maps:put(K1, 42, Map),
+              %% The map needed to contain at least 32 key-value pairs
+              %% at this point to get the crash or out of memory
+              %% problem on the next line
+              Map3 = maps:put(K2, 43, Map2),
+              %% The following line should avoid that the compiler
+              %% optimizes away the above
+              io:format("~p ~p~n", [erlang:phash2(Map3), maps:size(Map3)])
+      end).
+
+make_map(0) -> 
+    #{};
+make_map(Size) ->
+    maps:put(Size, Size, make_map(Size-1)).
+
+get_4GB_bin(Value) ->
+    List = lists:duplicate(65536, Value),
+    Bin = erlang:iolist_to_binary(List),
+    IOList4GB = duplicate_iolist(Bin, 16),
+    Bin4GB = erlang:iolist_to_binary(IOList4GB),
+    4294967296 = size(Bin4GB),
+    Bin4GB.
+
+duplicate_iolist(IOList, 0) ->
+    IOList;
+duplicate_iolist(IOList, NrOfTimes) ->
+    duplicate_iolist([IOList, IOList], NrOfTimes - 1).
+
+run_when_enough_resources(Fun) ->
+    case {total_memory(), erlang:system_info(wordsize)} of
+        {Mem, 8} when is_integer(Mem) andalso Mem >= 31 ->
+            Fun();
+        {Mem, WordSize} ->
+            {skipped, 
+             io_lib:format("Not enough resources (System Memory >= ~p, Word Size = ~p)",
+                           [Mem, WordSize])}
+    end.
+
+total_memory() ->
+    %% Total memory in GB.
+    try
+	MemoryData = memsup:get_system_memory_data(),
+	case lists:keysearch(total_memory, 1, MemoryData) of
+	    {value, {total_memory, TM}} ->
+		TM div (1024*1024*1024);
+	    false ->
+		{value, {system_total_memory, STM}} =
+		    lists:keysearch(system_total_memory, 1, MemoryData),
+		STM div (1024*1024*1024)
+	end
+    catch
+	_ : _ ->
+	    undefined
+    end.
diff --git a/erts/emulator/test/multi_load_SUITE.erl b/erts/emulator/test/multi_load_SUITE.erl
index edf3205812..c79e2b6dcd 100644
--- a/erts/emulator/test/multi_load_SUITE.erl
+++ b/erts/emulator/test/multi_load_SUITE.erl
@@ -30,7 +30,15 @@ all() ->
     [many,on_load,errors].
 
 many(_Config) ->
-    Ms = make_modules(100, fun many_module/1),
+
+    N = case erlang:system_info(build_type) of
+            valgrind ->
+                10;
+            _ ->
+                100
+        end,
+
+    Ms = make_modules(N, fun many_module/1),
 
     io:put_chars("Light load\n"
 		 "=========="),
diff --git a/erts/emulator/test/net_SUITE.erl b/erts/emulator/test/net_SUITE.erl
new file mode 100644
index 0000000000..c6e77a5373
--- /dev/null
+++ b/erts/emulator/test/net_SUITE.erl
@@ -0,0 +1,489 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2019-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+%%
+%% This test suite is basically a "placeholder" for a proper test suite...
+%% Also we should really call prim_net directly, and not net (since that does
+%% not even reside here).
+%%
+
+%% Run the entire test suite: 
+%% ts:run(emulator, net_SUITE, [batch]).
+%%
+%% Run a specific group:
+%% ts:run(emulator, net_SUITE, {group, foo}, [batch]).
+%%
+%% Run a specific test case:
+%% ts:run(emulator, net_SUITE, foo, [batch]).
+
+-module(net_SUITE).
+
+-include_lib("common_test/include/ct.hrl").
+-include_lib("common_test/include/ct_event.hrl").
+
+%% Suite exports
+-export([suite/0, all/0, groups/0]).
+-export([init_per_suite/1,    end_per_suite/1,
+         init_per_group/2,    end_per_group/2,
+         init_per_testcase/2, end_per_testcase/2]).
+
+%% Test cases
+-export([
+         %% *** API Basic ***
+         api_b_gethostname/1,
+         api_b_name_and_addr_info/1,
+         
+         api_b_name_and_index/1
+
+         %% Tickets
+        ]).
+
+
+%% -include("socket_test_evaluator.hrl").
+
+%% Internal exports
+%% -export([]).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+-define(SLEEP(T), receive after T -> ok end).
+
+-define(FAIL(R), exit(R)).
+
+-define(MINS(M), timer:minutes(M)).
+-define(SECS(S), timer:seconds(S)).
+
+-define(TT(T),   ct:timetrap(T)).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+suite() ->
+    [{ct_hooks,[ts_install_cth]},
+     {timetrap,{minutes,1}}].
+
+all() -> 
+    Groups = [{api, "ENET_TEST_API", include}],
+    [use_group(Group, Env, Default) || {Group, Env, Default} <- Groups].
+
+use_group(Group, Env, Default) ->
+	case os:getenv(Env) of
+	    false when (Default =:= include) ->
+		[{group, Group}];
+	    false ->
+		[];
+	    Val ->
+		case list_to_atom(string:to_lower(Val)) of
+		    Use when (Use =:= include) orelse 
+			     (Use =:= enable) orelse 
+			     (Use =:= true) ->
+			[{group, Group}];
+		    _ ->
+			[]
+		end
+	end.
+    
+
+groups() -> 
+    [{api,       [], api_cases()},
+     {api_basic, [], api_basic_cases()}
+
+     %% {tickets, [], ticket_cases()}
+    ].
+     
+api_cases() ->
+    [
+     {group, api_basic}
+    ].
+
+api_basic_cases() ->
+    [
+     api_b_gethostname,
+     api_b_name_and_addr_info,
+     api_b_name_and_index
+    ].
+
+%% ticket_cases() ->
+%%     [].
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+init_per_suite(Config) ->
+    %% We test on the socket module for simplicity
+    case lists:member(socket, erlang:loaded()) of
+        true ->
+            case os:type() of
+                {win32, _} ->
+                    not_yet_implemented();
+                _ ->
+                    %% ?LOGGER:start(),
+                    Config
+            end;
+        false ->
+            {skip, "esock disabled"}
+    end.
+
+end_per_suite(_) ->
+    %% ?LOGGER:stop(),
+    ok.
+
+init_per_group(_Group, Config) ->
+    Config.
+
+end_per_group(_Group, Config) ->
+    Config.
+
+
+init_per_testcase(_TC, Config) ->
+    Config.
+
+end_per_testcase(_TC, Config) ->
+    Config.
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%                                                                     %%
+%%                           API BASIC                                 %%
+%%                                                                     %%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Get the hostname of the host.
+api_b_gethostname(suite) ->
+    [];
+api_b_gethostname(doc) ->
+    [];
+api_b_gethostname(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_gethostname,
+           fun() ->
+                   ok = api_b_gethostname()
+           end).
+
+
+api_b_gethostname() ->
+    case net:gethostname() of
+        {ok, Hostname} ->
+            i("hostname: ~s", [Hostname]),
+            ok;
+        {error, Reason} ->
+            ?FAIL(Reason)
+    end.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Get name and address info.
+api_b_name_and_addr_info(suite) ->
+    [];
+api_b_name_and_addr_info(doc) ->
+    [];
+api_b_name_and_addr_info(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_name_and_addr_info,
+           fun() ->
+                   ok = api_b_name_and_addr_info()
+           end).
+
+
+api_b_name_and_addr_info() ->
+    Domain = inet,
+    Addr   = which_local_addr(Domain),
+    SA     = #{family => Domain, addr => Addr},
+    Hostname =
+        case net:getnameinfo(SA) of
+            {ok, #{host := Name, service := Service} = NameInfo} 
+              when is_list(Name) andalso is_list(Service) ->
+                i("getnameinfo: "
+                  "~n   ~p", [NameInfo]),
+                Name;
+            {ok, BadNameInfo} ->
+                ?FAIL({getnameinfo, SA, BadNameInfo});
+            {error, Reason1} ->
+                ?FAIL({getnameinfo, SA, Reason1})
+        end,
+    case net:getaddrinfo(Hostname) of
+        {ok, AddrInfos} when is_list(AddrInfos) ->
+            i("getaddrinfo: "
+              "~n   ~p", [AddrInfos]),
+            verify_addr_info(AddrInfos, Domain);
+        {ok, BadAddrInfo} ->
+            ?FAIL({getaddrinfo, Hostname, BadAddrInfo});
+        {error, Reason2} ->
+            ?FAIL({getaddrinfo, Hostname, Reason2})
+    end.
+
+
+verify_addr_info(AddrInfos, Domain) when (AddrInfos =/= []) ->
+    verify_addr_info2(AddrInfos, Domain).
+    
+verify_addr_info2([], _Domain) ->
+    ok;
+verify_addr_info2([#{addr     := #{addr   := Addr,
+				   family := Domain,
+				   port   := Port},
+                     family   := Domain,
+                     type     := _Type,
+                     protocol := _Proto}|T], Domain) 
+  when is_integer(Port) andalso
+       (((Domain =:= inet) andalso is_tuple(Addr) andalso (size(Addr) =:= 4)) orelse
+        ((Domain =:= inet6) andalso is_tuple(Addr) andalso (size(Addr) =:= 8))) -> 
+    verify_addr_info2(T, Domain);
+verify_addr_info2([#{family := DomainA}|T], DomainB) 
+  when (DomainA =/= DomainB) ->
+    %% Ignore entries for other domains
+    verify_addr_info2(T, DomainB);
+verify_addr_info2([BadAddrInfo|_], Domain) ->
+    ?FAIL({bad_address_info, BadAddrInfo, Domain}).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Verify (interface) name and index functions.
+%% if_names/0,
+%% if_name2index/1
+%% if_index2name/1
+api_b_name_and_index(suite) ->
+    [];
+api_b_name_and_index(doc) ->
+    [];
+api_b_name_and_index(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_name_and_index,
+           fun() ->
+                   ok = api_b_name_and_index()
+           end).
+
+
+api_b_name_and_index() ->
+    Names =
+        case net:if_names() of
+            {ok, N} when is_list(N) andalso (N =/= []) ->
+                N;
+            {error, Reason} ->
+                ?FAIL({if_names, Reason})
+        end,
+    verify_if_names(Names).
+
+verify_if_names([]) ->
+    ok;
+verify_if_names([{Index, Name}|T]) ->
+    case net:if_name2index(Name) of
+        {ok, Index} ->
+            ok;
+        {ok, BadIndex} ->
+            ?FAIL({name2index, Name, Index, BadIndex});
+        {error, ReasonN2I} ->
+            ?FAIL({name2index, Name, ReasonN2I})
+    end,
+    case net:if_index2name(Index) of
+        {ok, Name} ->
+            ok;
+        {ok, BadName} ->
+            ?FAIL({index2name, Index, Name, BadName});
+        {error, ReasonI2N} ->
+            ?FAIL({index2name, Index, ReasonI2N})
+    end,
+    verify_if_names(T).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% local_host() ->
+%%     try net_adm:localhost() of
+%%         Host when is_list(Host) ->
+%% 	    %% Convert to shortname if long
+%% 	    case string:tokens(Host, [$.]) of
+%% 		[H|_] ->
+%% 		    list_to_atom(H)
+%% 	    end
+%%     catch
+%%         C:E:S ->
+%%             erlang:raise(C, E, S)
+%%     end.
+
+
+%% This gets the local address (not 127.0...)
+%% We should really implement this using the (new) net module,
+%% but until that gets the necessary functionality...
+which_local_addr(Domain) ->
+    case inet:getifaddrs() of
+        {ok, IFL} ->
+            which_addr(Domain, IFL);
+        {error, Reason} ->
+            ?FAIL({inet, getifaddrs, Reason})
+    end.
+
+which_addr(_Domain, []) ->
+    skip(no_address);
+which_addr(Domain, [{"lo" ++ _, _}|IFL]) ->
+    which_addr(Domain, IFL);
+which_addr(Domain, [{_Name, IFO}|IFL]) ->
+    case which_addr2(Domain, IFO) of
+        {ok, Addr} ->
+            Addr;
+        {error, no_address} ->
+            which_addr(Domain, IFL)
+    end;
+which_addr(Domain, [_|IFL]) ->
+    which_addr(Domain, IFL).
+
+which_addr2(_Domain, []) ->
+    {error, no_address};
+which_addr2(inet = _Domain, [{addr, Addr}|_IFO]) when (size(Addr) =:= 4) ->
+    {ok, Addr};
+which_addr2(inet6 = _Domain, [{addr, Addr}|_IFO]) when (size(Addr) =:= 8) ->
+    {ok, Addr};
+which_addr2(Domain, [_|IFO]) ->
+    which_addr2(Domain, IFO).
+
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+not_yet_implemented() ->
+    skip("not yet implemented").
+
+skip(Reason) ->
+    throw({skip, Reason}).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% t() ->
+%%     os:timestamp().
+
+
+%% tdiff({A1, B1, C1} = _T1x, {A2, B2, C2} = _T2x) ->
+%%     T1 = A1*1000000000+B1*1000+(C1 div 1000), 
+%%     T2 = A2*1000000000+B2*1000+(C2 div 1000), 
+%%     T2 - T1.
+
+
+formated_timestamp() ->
+    format_timestamp(os:timestamp()).
+
+format_timestamp({_N1, _N2, _N3} = TS) ->
+    {_Date, Time}   = calendar:now_to_local_time(TS),
+    %% {YYYY,MM,DD}   = Date,
+    {Hour,Min,Sec} = Time,
+    %% FormatTS = 
+    %%     io_lib:format("~.4w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w.~w",
+    %%                   [YYYY, MM, DD, Hour, Min, Sec, N3]),  
+    FormatTS = io_lib:format("~.2.0w:~.2.0w:~.2.0w", [Hour, Min, Sec]),  
+    lists:flatten(FormatTS).
+
+   
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+set_tc_name(N) when is_atom(N) ->
+    set_tc_name(atom_to_list(N));
+set_tc_name(N) when is_list(N) ->
+    put(tc_name, N).
+
+%% get_tc_name() ->
+%%     get(tc_name).
+
+tc_begin(TC) ->
+    set_tc_name(TC),
+    tc_print("begin ***",
+             "~n----------------------------------------------------~n", "").
+    
+tc_end(Result) when is_list(Result) ->
+    tc_print("done: ~s", [Result], 
+             "", "----------------------------------------------------~n~n"),
+    ok.
+
+
+tc_try(Case, Fun) when is_atom(Case) andalso is_function(Fun, 0) ->
+    tc_begin(Case),
+    try 
+        begin
+            Fun(),
+            ?SLEEP(?SECS(1)),
+            tc_end("ok")
+        end
+    catch
+        throw:{skip, _} = SKIP ->
+            tc_end("skipping"),
+            SKIP;
+        Class:Error:Stack ->
+            tc_end("failed"),
+            erlang:raise(Class, Error, Stack)
+    end.
+
+
+tc_print(F, Before, After) ->
+    tc_print(F, [], Before, After).
+
+tc_print(F, A, Before, After) ->
+    Name = tc_which_name(),
+    FStr = f("*** [~s][~s][~p] " ++ F ++ "~n", 
+             [formated_timestamp(),Name,self()|A]),
+    io:format(user, Before ++ FStr ++ After, []).
+
+tc_which_name() ->
+    case get(tc_name) of
+        undefined ->
+            case get(sname) of
+                undefined ->
+                    "";
+                SName when is_list(SName) ->
+                    SName
+            end;
+        Name when is_list(Name) ->
+            Name
+    end.
+    
+   
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% l2a(S) when is_list(S) ->
+%%     list_to_atom(S).
+
+%% l2b(L) when is_list(L) ->
+%%     list_to_binary(L).
+
+%% b2l(B) when is_binary(B) ->
+%%     binary_to_list(B).
+
+f(F, A) ->
+    lists:flatten(io_lib:format(F, A)).
+
+
+%% i(F) ->
+%%     i(F, []).
+
+i(F, A) ->
+    FStr = f("[~s] " ++ F, [formated_timestamp()|A]),
+    io:format(user, FStr ++ "~n", []),
+    io:format(FStr, []).
+
diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl
index a2f3489943..b824daea67 100644
--- a/erts/emulator/test/nif_SUITE.erl
+++ b/erts/emulator/test/nif_SUITE.erl
@@ -28,6 +28,7 @@
 -include_lib("stdlib/include/assert.hrl").
 
 -export([all/0, suite/0, groups/0,
+         init_per_suite/1, end_per_suite/1,
          init_per_group/2, end_per_group/2,
 	 init_per_testcase/2, end_per_testcase/2,
          basic/1, reload_error/1, upgrade/1, heap_frag/1,
@@ -64,7 +65,9 @@
          nif_phash2/1,
          nif_whereis/1, nif_whereis_parallel/1,
          nif_whereis_threaded/1, nif_whereis_proxy/1,
-         nif_ioq/1
+         nif_ioq/1,
+         pid/1,
+         nif_term_type/1
 	]).
 
 -export([many_args_100/100]).
@@ -103,7 +106,17 @@ all() ->
      nif_internal_hash_salted,
      nif_phash2,
      nif_whereis, nif_whereis_parallel, nif_whereis_threaded,
-     nif_ioq].
+     nif_ioq,
+     pid,
+     nif_term_type].
+
+init_per_suite(Config) ->
+    erts_debug:set_internal_state(available_internal_state, true),
+    Config.
+
+end_per_suite(_Config) ->
+    catch erts_debug:set_internal_state(available_internal_state, false),
+    ok.
 
 groups() ->
     [{G, [], api_repeaters()} || G <- api_groups()]
@@ -114,7 +127,6 @@ groups() ->
                     monitor_process_d,
                     demonitor_process]}].
 
-
 api_groups() -> [api_latest, api_2_4, api_2_0].
 
 api_repeaters() -> [upgrade, resource_takeover, t_on_load].
@@ -485,91 +497,118 @@ t_on_load(Config) when is_list(Config) ->
 -define(ERL_NIF_SELECT_READ, (1 bsl 0)).
 -define(ERL_NIF_SELECT_WRITE, (1 bsl 1)).
 -define(ERL_NIF_SELECT_STOP, (1 bsl 2)).
+-define(ERL_NIF_SELECT_CANCEL, (1 bsl 3)).
+-define(ERL_NIF_SELECT_CUSTOM_MSG, (1 bsl 4)).
 
 -define(ERL_NIF_SELECT_STOP_CALLED, (1 bsl 0)).
 -define(ERL_NIF_SELECT_STOP_SCHEDULED, (1 bsl 1)).
 -define(ERL_NIF_SELECT_INVALID_EVENT, (1 bsl 2)).
 -define(ERL_NIF_SELECT_FAILED, (1 bsl 3)).
-
+-define(ERL_NIF_SELECT_READ_CANCELLED, (1 bsl 4)).
+-define(ERL_NIF_SELECT_WRITE_CANCELLED, (1 bsl 5)).
 
 select(Config) when is_list(Config) ->
     ensure_lib_loaded(Config),
+    select_do(0, make_ref(), make_ref(), null),
+
+    RefBin = list_to_binary(lists:duplicate(100, $x)),
+    [select_do(?ERL_NIF_SELECT_CUSTOM_MSG,
+               small, {a, tuple, with, "some", RefBin}, MSG_ENV)
+     || MSG_ENV <- [null, alloc_env]],
+    ok.
+
+select_do(Flag, Ref, Ref2, MSG_ENV) ->
+    io:format("select_do(~p, ~p, ~p)\n", [Ref, Ref2, MSG_ENV]),
 
-    Ref = make_ref(),
-    Ref2 = make_ref(),
     {{R, R_ptr}, {W, W_ptr}} = pipe_nif(),
     ok = write_nif(W, <<"hej">>),
     <<"hej">> = read_nif(R, 3),
 
     %% Wait for read
     eagain = read_nif(R, 3),
-    0 = select_nif(R,?ERL_NIF_SELECT_READ,R,null,Ref),
+    0 = select_nif(R,?ERL_NIF_SELECT_READ bor Flag, R,null,Ref,MSG_ENV),
     [] = flush(0),
     ok = write_nif(W, <<"hej">>),
-    [{select, R, Ref, ready_input}] = flush(),
-    0 = select_nif(R,?ERL_NIF_SELECT_READ,R,self(),Ref2),
-    [{select, R, Ref2, ready_input}] = flush(),
+    receive_ready(R, Ref, ready_input),
+    0 = select_nif(R,?ERL_NIF_SELECT_READ bor Flag,R,self(),Ref2,MSG_ENV),
+    receive_ready(R, Ref2, ready_input),
     Papa = self(),
     Pid = spawn_link(fun() ->
-                             [{select, R, Ref, ready_input}] = flush(),
+                             receive_ready(R, Ref, ready_input),
                              Papa ! {self(), done}
                      end),
-    0 = select_nif(R,?ERL_NIF_SELECT_READ,R,Pid,Ref),
+    0 = select_nif(R, ?ERL_NIF_SELECT_READ bor Flag, R, Pid, Ref,MSG_ENV),
     {Pid, done} = receive_any(1000),
+
+    %% Cancel read
+    0 = select_nif(R,?ERL_NIF_SELECT_READ bor ?ERL_NIF_SELECT_CANCEL,R,null,Ref,null),
     <<"hej">> = read_nif(R, 3),
+    0 = select_nif(R, ?ERL_NIF_SELECT_READ bor Flag, R, null, Ref, MSG_ENV),
+    ?ERL_NIF_SELECT_READ_CANCELLED =
+        select_nif(R,?ERL_NIF_SELECT_READ bor ?ERL_NIF_SELECT_CANCEL,R,null,Ref,null),
+    ok = write_nif(W, <<"hej again">>),
+    [] = flush(0),
+    <<"hej again">> = read_nif(R, 9),
 
     %% Wait for write
     Written = write_full(W, $a),
-    0 = select_nif(W,?ERL_NIF_SELECT_WRITE,W,self(),Ref),
+    0 = select_nif(W, ?ERL_NIF_SELECT_WRITE bor Flag, W, self(), Ref, MSG_ENV),
     [] = flush(0),
     Written = read_nif(R,byte_size(Written)),
-    [{select, W, Ref, ready_output}] = flush(),
+    receive_ready(W, Ref, ready_output),
+
+    %% Cancel write
+    0 = select_nif(W, ?ERL_NIF_SELECT_WRITE bor ?ERL_NIF_SELECT_CANCEL, W, null, Ref, null),
+    Written2 = write_full(W, $b),
+    0 = select_nif(W, ?ERL_NIF_SELECT_WRITE bor Flag, W, null, Ref, MSG_ENV),
+    ?ERL_NIF_SELECT_WRITE_CANCELLED =
+        select_nif(W, ?ERL_NIF_SELECT_WRITE bor ?ERL_NIF_SELECT_CANCEL, W, null, Ref, null),
+    Written2 = read_nif(R,byte_size(Written2)),
+    [] = flush(0),
 
     %% Close write and wait for EOF
     eagain = read_nif(R, 1),
-    check_stop_ret(select_nif(W,?ERL_NIF_SELECT_STOP,W,null,Ref)),
+    check_stop_ret(select_nif(W, ?ERL_NIF_SELECT_STOP, W, null, Ref, null)),
     [{fd_resource_stop, W_ptr, _}] = flush(),
     {1, {W_ptr,_}} = last_fd_stop_call(),
     true = is_closed_nif(W),
     [] = flush(0),
-    0 = select_nif(R,?ERL_NIF_SELECT_READ,R,self(),Ref),
-    [{select, R, Ref, ready_input}] = flush(),
+    0 = select_nif(R, ?ERL_NIF_SELECT_READ bor Flag, R, self(), Ref, MSG_ENV),
+    receive_ready(R, Ref, ready_input),
     eof = read_nif(R,1),
 
-    check_stop_ret(select_nif(R,?ERL_NIF_SELECT_STOP,R,null,Ref)),
+    check_stop_ret(select_nif(R, ?ERL_NIF_SELECT_STOP, R, null, Ref, null)),
     [{fd_resource_stop, R_ptr, _}] = flush(),
     {1, {R_ptr,_}} = last_fd_stop_call(),
     true = is_closed_nif(R),
 
-    select_2(Config).
+    select_2(Flag, Ref, Ref2, MSG_ENV).
 
-select_2(Config) ->
+select_2(Flag, Ref1, Ref2, MSG_ENV) ->
     erlang:garbage_collect(),
     {_,_,2} = last_resource_dtor_call(),
 
-    Ref1 = make_ref(),
-    Ref2 = make_ref(),
     {{R, R_ptr}, {W, W_ptr}} = pipe_nif(),
 
     %% Change ref
     eagain = read_nif(R, 1),
-    0 = select_nif(R,?ERL_NIF_SELECT_READ,R,null,Ref1),
-    0 = select_nif(R,?ERL_NIF_SELECT_READ,R,self(),Ref2),
+    0 = select_nif(R, ?ERL_NIF_SELECT_READ bor Flag, R, null, Ref1, MSG_ENV),
+    0 = select_nif(R, ?ERL_NIF_SELECT_READ bor Flag, R, self(), Ref2, MSG_ENV),
 
     [] = flush(0),
     ok = write_nif(W, <<"hej">>),
-    [{select, R, Ref2, ready_input}] = flush(),
+    receive_ready(R, Ref2, ready_input),
     <<"hej">> = read_nif(R, 3),
 
     %% Change pid
     eagain = read_nif(R, 1),
-    0 = select_nif(R,?ERL_NIF_SELECT_READ,R,null,Ref1),
+    0 = select_nif(R, ?ERL_NIF_SELECT_READ bor Flag, R, null, Ref1, MSG_ENV),
     Papa = self(),
     spawn_link(fun() ->
-                       0 = select_nif(R,?ERL_NIF_SELECT_READ,R,null,Ref1),
+                       0 = select_nif(R, ?ERL_NIF_SELECT_READ bor Flag, R, null, Ref1, MSG_ENV),
                        [] = flush(0),
                        Papa ! sync,
-                       [{select, R, Ref1, ready_input}] = flush(),
+                       receive_ready(R, Ref1, ready_input),
                        <<"hej">> = read_nif(R, 3),
                        Papa ! done
                end),
@@ -578,24 +617,30 @@ select_2(Config) ->
     done = receive_any(),
     [] = flush(0),
 
-    check_stop_ret(select_nif(R,?ERL_NIF_SELECT_STOP,R,null,Ref1)),
+    check_stop_ret(select_nif(R,?ERL_NIF_SELECT_STOP,R,null,Ref1, null)),
     [{fd_resource_stop, R_ptr, _}] = flush(),
     {1, {R_ptr,_}} = last_fd_stop_call(),
     true = is_closed_nif(R),
 
     %% Stop without previous read/write select
-    ?ERL_NIF_SELECT_STOP_CALLED = select_nif(W,?ERL_NIF_SELECT_STOP,W,null,Ref1),
+    ?ERL_NIF_SELECT_STOP_CALLED = select_nif(W,?ERL_NIF_SELECT_STOP,W,null,Ref1,null),
     [{fd_resource_stop, W_ptr, 1}] = flush(),
     {1, {W_ptr,1}} = last_fd_stop_call(),
     true = is_closed_nif(W),
 
-    select_3(Config).
+    select_3().
 
-select_3(_Config) ->
+select_3() ->
     erlang:garbage_collect(),
     {_,_,2} = last_resource_dtor_call(),
     ok.
 
+receive_ready(R, Ref, IOatom) when is_reference(Ref) ->
+    [{select, R, Ref, IOatom}] = flush();
+receive_ready(_, Msg, _) ->
+    [Got] = flush(),
+    {true,_,_} = {Got=:=Msg, Got, Msg}.
+
 %% @doc The stealing child process for the select_steal test. Duplicates given
 %% W/RFds and runs select on them to steal
 select_steal_child_process(Parent, RFd) ->
@@ -604,7 +649,7 @@ select_steal_child_process(Parent, RFd) ->
     Ref2 = make_ref(),
 
     %% Try to select from the child pid (steal from parent)
-    ?assertEqual(0, select_nif(R2Fd, ?ERL_NIF_SELECT_READ, R2Fd, null, Ref2)),
+    ?assertEqual(0, select_nif(R2Fd, ?ERL_NIF_SELECT_READ, R2Fd, null, Ref2, null)),
     ?assertEqual([], flush(0)),
     ?assertEqual(eagain, read_nif(R2Fd, 1)),
 
@@ -612,7 +657,7 @@ select_steal_child_process(Parent, RFd) ->
     Parent ! {self(), stage1}, % signal parent to send the <<"stolen1">>
 
     %% Receive <<"stolen1">> via enif_select
-    ?assertEqual(0, select_nif(R2Fd, ?ERL_NIF_SELECT_READ, R2Fd, null, Ref2)),
+    ?assertEqual(0, select_nif(R2Fd, ?ERL_NIF_SELECT_READ, R2Fd, null, Ref2, null)),
     ?assertMatch([{select, R2Fd, Ref2, ready_input}], flush()),
     ?assertEqual(<<"stolen1">>, read_nif(R2Fd, 7)),
 
@@ -630,7 +675,7 @@ select_steal(Config) when is_list(Config) ->
     {{RFd, RPtr}, {WFd, WPtr}} = pipe_nif(),
 
     %% Bind the socket to current pid in enif_select
-    ?assertEqual(0, select_nif(RFd, ?ERL_NIF_SELECT_READ, RFd, null, Ref)),
+    ?assertEqual(0, select_nif(RFd, ?ERL_NIF_SELECT_READ, RFd, null, Ref, null)),
     ?assertEqual([], flush(0)),
 
     %% Spawn a process and do some stealing
@@ -644,15 +689,15 @@ select_steal(Config) when is_list(Config) ->
     ?assertMatch([{Pid, done}], flush(1)),  % synchronize with the child
 
     %% Try to select from the parent pid (steal back)
-    ?assertEqual(0, select_nif(RFd, ?ERL_NIF_SELECT_READ, RFd, Pid, Ref)),
+    ?assertEqual(0, select_nif(RFd, ?ERL_NIF_SELECT_READ, RFd, Pid, Ref, null)),
 
     %% Ensure that no data is hanging and close.
     %% Rfd is stolen at this point.
-    check_stop_ret(select_nif(WFd, ?ERL_NIF_SELECT_STOP, WFd, null, Ref)),
+    check_stop_ret(select_nif(WFd, ?ERL_NIF_SELECT_STOP, WFd, null, Ref, null)),
     ?assertMatch([{fd_resource_stop, WPtr, _}], flush()),
     {1, {WPtr, 1}} = last_fd_stop_call(),
 
-    check_stop_ret(select_nif(RFd, ?ERL_NIF_SELECT_STOP, RFd, null, Ref)),
+    check_stop_ret(select_nif(RFd, ?ERL_NIF_SELECT_STOP, RFd, null, Ref, null)),
     ?assertMatch([{fd_resource_stop, RPtr, _}], flush()),
     {1, {RPtr, _DirectCall}} = last_fd_stop_call(),
 
@@ -789,8 +834,11 @@ demonitor_process(Config) ->
                      end),
     R_ptr = alloc_monitor_resource_nif(),
     {0,MonBin1} = monitor_process_nif(R_ptr, Pid, true, self()),
+    MonTerm1 = make_monitor_term_nif(MonBin1),
     [R_ptr] = monitored_by(Pid),
     {0,MonBin2} = monitor_process_nif(R_ptr, Pid, true, self()),
+    MonTerm2 = make_monitor_term_nif(MonBin2),
+    true = (MonTerm1 =/= MonTerm2),
     [R_ptr, R_ptr] = monitored_by(Pid),
     0 = demonitor_process_nif(R_ptr, MonBin1),
     [R_ptr] = monitored_by(Pid),
@@ -804,6 +852,10 @@ demonitor_process(Config) ->
     {R_ptr, _, 1} = last_resource_dtor_call(),
     [] = monitored_by(Pid),
     Pid ! return,
+
+    erlang:garbage_collect(),
+    true = (MonTerm1 =/= MonTerm2),
+    io:format("MonTerm1 = ~p\nMonTerm2 = ~p\n", [MonTerm1, MonTerm2]),
     ok.
 
 
@@ -1175,6 +1227,15 @@ maps(Config) when is_list(Config) ->
     M2 = maps_from_list_nif(maps:to_list(M2)),
     M3 = maps_from_list_nif(maps:to_list(M3)),
 
+    %% Test different map sizes (OTP-15567)
+    repeat_while(fun({35,_}) -> false;
+                    ({K,Map}) ->
+                         Map = maps_from_list_nif(maps:to_list(Map)),
+                         Map = maps:filter(fun(K2,V) -> V =:= K2*100 end, Map),
+                         {K+1, maps:put(K,K*100,Map)}
+                 end,
+                 {1,#{}}),
+
     has_duplicate_keys = maps_from_list_nif([{1,1},{1,1}]),
 
     verify_tmpmem(TmpMem),
@@ -1241,24 +1302,29 @@ resource_hugo_do(Type) ->
     release_resource(HugoPtr),
     erlang:garbage_collect(),
     {HugoPtr,HugoBin} = get_resource(Type,Hugo),
-    Pid = spawn_link(fun() -> 			     
-                             receive {Pid, Type, Resource, Ptr, Bin} ->
-                                         Pid ! {self(), got_it},
-                                         receive {Pid, check_it} ->
-                                                     {Ptr,Bin} = get_resource(Type,Resource),
-                                                     Pid ! {self(), ok}
-                                         end
-                             end
-                     end),
+    {Pid,_} =
+        spawn_monitor(fun() ->
+                              receive {Pid, Type, Resource, Ptr, Bin} ->
+                                      Pid ! {self(), got_it},
+                                      receive {Pid, check_it} ->
+                                              {Ptr,Bin} = get_resource(Type,Resource)
+                                      end
+                              end,
+                              gc_and_exit(ok)
+                      end),
     Pid ! {self(), Type, Hugo, HugoPtr, HugoBin},
     {Pid, got_it} = receive_any(),
     erlang:garbage_collect(),   % just to make our ProcBin move in memory
     Pid ! {self(), check_it},
-    {Pid, ok} = receive_any(),
+    {'DOWN', _, process, Pid, ok} = receive_any(),
     [] = last_resource_dtor_call(),
     {HugoPtr,HugoBin} = get_resource(Type,Hugo),
     {HugoPtr, HugoBin, 1}.
 
+gc_and_exit(Reason) ->
+    erlang:garbage_collect(),
+    exit(Reason).
+
 resource_otto(Type) ->
     {OttoPtr, OttoBin} = resource_otto_do(Type),
     erlang:garbage_collect(),
@@ -1335,14 +1401,14 @@ resource_binary_do() ->
     ResInfo = {Ptr,_} = get_resource(binary_resource_type,ResBin1),
 
     Papa = self(),
-    Forwarder = spawn_link(fun() -> forwarder(Papa) end),
+    {Forwarder,_} = spawn_monitor(fun() -> forwarder(Papa) end),
     io:format("sending to forwarder pid=~p\n",[Forwarder]),  
     Forwarder ! ResBin1,
     ResBin2 = receive_any(),
     ResBin2 = ResBin1,
     ResInfo = get_resource(binary_resource_type,ResBin2),
     Forwarder ! terminate,
-    {Forwarder, 1} = receive_any(),
+    {'DOWN', _, process, Forwarder, 1} = receive_any(),
     erlang:garbage_collect(),
     ResInfo = get_resource(binary_resource_type,ResBin1),
     ResInfo = get_resource(binary_resource_type,ResBin2),
@@ -1702,6 +1768,7 @@ read_resource(Type, {Holder,Id}) ->
 forget_resource({Holder,Id}) ->
     Holder ! {self(), forget, Id},
     {Holder, forget_ok, Id} = receive_any(),
+    erts_debug:set_internal_state(wait, aux_work),
     ok.
 
 
@@ -1862,11 +1929,11 @@ send2_do1(SendBlobF) ->
     send2_do2(SendBlobF, self()),
 
     Papa = self(),
-    Forwarder = spawn_link(fun() -> forwarder(Papa) end),
+    {Forwarder,_} = spawn_monitor(fun() -> forwarder(Papa) end),
     io:format("sending to forwarder pid=~p\n",[Forwarder]),
     send2_do2(SendBlobF, Forwarder),
     Forwarder ! terminate,
-    {Forwarder, 4} = receive_any(),
+    {'DOWN', _, process, Forwarder, 4} = receive_any(),
     ok.
 
 send2_do2(SendBlobF, To) ->   
@@ -1922,7 +1989,7 @@ forwarder(To) ->
 forwarder(To, N) ->
     case receive_any() of
 	terminate ->
-	    To ! {self(), N};
+            gc_and_exit(N);
 	Msg ->	    
 	    To ! Msg,	   
 	    forwarder(To, N+1)
@@ -2471,6 +2538,13 @@ repeat(0, _, Arg) ->
 repeat(N, Fun, Arg0) ->
     repeat(N-1, Fun, Fun(Arg0)).
 
+repeat_while(Fun, Acc0) ->
+    case Fun(Acc0) of
+        false -> ok;
+        Acc1 ->
+            repeat_while(Fun, Acc1)
+    end.
+
 check(Exp,Got,Line) ->
     case Got of
  	Exp -> Exp;	    
@@ -3040,22 +3114,31 @@ nif_whereis_threaded(Config) when is_list(Config) ->
     RegName = nif_whereis_test_threaded,
     undefined = erlang:whereis(RegName),
 
-    Ref = make_ref(),
-    {Pid, Mon} = spawn_monitor(?MODULE, nif_whereis_proxy, [Ref]),
-    true = register(RegName, Pid),
+    Self = self(),
+    true = register(RegName, Self),
 
-    {ok, ProcThr} = whereis_thd_lookup(pid, RegName),
-    {ok, Pid} = whereis_thd_result(ProcThr),
+    {ok, ProcThr} = whereis_thd_lookup(pid, RegName, "dtor to proc"),
+    {ok, Self} = whereis_thd_result(ProcThr),
 
-    Pid ! {Ref, quit},
-    ok = receive {'DOWN', Mon, process, Pid, normal} -> ok end,
+    nif_whereis_threaded_2(RegName).
+
+nif_whereis_threaded_2(RegName) ->
+    erlang:garbage_collect(),
+    "dtor to proc" = receive_any(1000),
+    true = unregister(RegName),
 
     Port = open_port({spawn, echo_drv}, [eof]),
     true = register(RegName, Port),
 
-    {ok, PortThr} = whereis_thd_lookup(port, RegName),
+    {ok, PortThr} = whereis_thd_lookup(port, RegName, "dtor to port"),
     {ok, Port} = whereis_thd_result(PortThr),
 
+    nif_whereis_threaded_3(Port).
+
+nif_whereis_threaded_3(Port) ->
+    erlang:garbage_collect(),
+    {Port, {data, "dtor to port"}} = receive_any(1000),
+
     port_close(Port),
     ok.
 
@@ -3311,6 +3394,69 @@ make_unaligned_binary(Bin0) ->
     <<0:3,Bin:Size/binary,31:5>> = id(<<0:3,Bin0/binary,31:5>>),
     Bin.
 
+pid(Config) ->
+    ensure_lib_loaded(Config),
+    Self = self(),
+    {true, ErlNifPid} = get_local_pid_nif(Self),
+    false = is_pid_undefined_nif(ErlNifPid),
+    Self = make_pid_nif(ErlNifPid),
+
+    UndefPid = set_pid_undefined_nif(),
+    true = is_pid_undefined_nif(UndefPid),
+    undefined = make_pid_nif(UndefPid),
+    0 = send_term(UndefPid, message),
+
+    Other = spawn(fun() -> ok end),
+    {true,OtherNifPid} = get_local_pid_nif(Other),
+    Cmp = compare_pids_nif(ErlNifPid, OtherNifPid),
+    true = if Cmp < 0 -> Self < Other;
+              Cmp > 0 -> Self > Other
+           end,
+    0 = compare_pids_nif(ErlNifPid, ErlNifPid),
+
+    {false, _} = get_local_pid_nif(undefined),
+    ok.
+
+nif_term_type(Config) ->
+    ensure_lib_loaded(Config),
+
+    atom = term_type_nif(atom),
+
+    bitstring = term_type_nif(<<1:1>>),
+    bitstring = term_type_nif(<<1:8>>),
+
+    float = term_type_nif(0.0),
+
+    'fun' = term_type_nif(fun external:function/1),
+    'fun' = term_type_nif(fun(A) -> A end),
+    'fun' = term_type_nif(fun id/1),
+
+    integer = term_type_nif(1 bsl 1024),        %Bignum.
+    integer = term_type_nif(1),
+
+    list = term_type_nif([list]),
+    list = term_type_nif([]),
+
+    LargeMap = maps:from_list([{N, N} || N <- lists:seq(1, 256)]),
+    map = term_type_nif(LargeMap),
+    map = term_type_nif(#{ small => map }),
+
+    pid = term_type_nif(self()),
+
+    Port = open_port({spawn,echo_drv},[eof]),
+    port = term_type_nif(Port),
+    port_close(Port),
+
+    reference = term_type_nif(make_ref()),
+
+    tuple = term_type_nif({}),
+
+    ok.
+
+last_resource_dtor_call() ->
+    erts_debug:set_internal_state(wait, aux_work),
+    last_resource_dtor_call_nif().
+
 id(I) -> I.
 
 %% The NIFs:
@@ -3338,7 +3484,7 @@ make_resource(_) -> ?nif_stub.
 get_resource(_,_) -> ?nif_stub.
 release_resource(_) -> ?nif_stub.
 release_resource_from_thread(_) -> ?nif_stub.
-last_resource_dtor_call() -> ?nif_stub.
+last_resource_dtor_call_nif() -> ?nif_stub.
 make_new_resource(_,_) -> ?nif_stub.
 check_is(_,_,_,_,_,_,_,_,_,_,_) -> ?nif_stub.
 check_is_exception() -> ?nif_stub.
@@ -3376,7 +3522,7 @@ term_to_binary_nif(_, _) -> ?nif_stub.
 binary_to_term_nif(_, _, _) -> ?nif_stub.
 port_command_nif(_, _) -> ?nif_stub.
 format_term_nif(_,_) -> ?nif_stub.
-select_nif(_,_,_,_,_) -> ?nif_stub.
+select_nif(_,_,_,_,_,_) -> ?nif_stub.
 dupe_resource_nif(_) -> ?nif_stub.
 pipe_nif() -> ?nif_stub.
 write_nif(_,_) -> ?nif_stub.
@@ -3388,6 +3534,7 @@ alloc_monitor_resource_nif() -> ?nif_stub.
 monitor_process_nif(_,_,_,_) -> ?nif_stub.
 demonitor_process_nif(_,_) -> ?nif_stub.
 compare_monitors_nif(_,_) -> ?nif_stub.
+make_monitor_term_nif(_) -> ?nif_stub.
 monitor_frenzy_nif(_,_,_,_) -> ?nif_stub.
 ioq_nif(_) -> ?nif_stub.
 ioq_nif(_,_) -> ?nif_stub.
@@ -3397,7 +3544,7 @@ ioq_nif(_,_,_,_) -> ?nif_stub.
 %% whereis
 whereis_send(_Type,_Name,_Msg) -> ?nif_stub.
 whereis_term(_Type,_Name) -> ?nif_stub.
-whereis_thd_lookup(_Type,_Name) -> ?nif_stub.
+whereis_thd_lookup(_Type,_Name, _Msg) -> ?nif_stub.
 whereis_thd_result(_Thd) -> ?nif_stub.
 
 %% maps
@@ -3418,5 +3565,13 @@ convert_time_unit(_,_,_) -> ?nif_stub.
 now_time() -> ?nif_stub.
 cpu_time() -> ?nif_stub.
 
+get_local_pid_nif(_) -> ?nif_stub.
+make_pid_nif(_) -> ?nif_stub.
+set_pid_undefined_nif() -> ?nif_stub.
+is_pid_undefined_nif(_) -> ?nif_stub.
+compare_pids_nif(_, _) -> ?nif_stub.
+
+term_type_nif(_) -> ?nif_stub.
+
 nif_stub_error(Line) ->
     exit({nif_not_loaded,module,?MODULE,line,Line}).
diff --git a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
index f2ce6dbe67..ff47cfe500 100644
--- a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
+++ b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
@@ -27,6 +27,7 @@
 #ifndef __WIN32__
 #include <unistd.h>
 #include <fcntl.h>
+#include <sys/uio.h>
 #endif
 
 #include "nif_mod.h"
@@ -707,28 +708,23 @@ static ERL_NIF_TERM tuple_2_list(ErlNifEnv* env, int argc, const ERL_NIF_TERM ar
 
 static ERL_NIF_TERM is_identical(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {    
-    if (argc != 2) {
-	return enif_make_badarg(env);
-    }
+    assert(argc == 2);
     return enif_make_atom(env, (enif_is_identical(argv[0],argv[1]) ?
 				"true" : "false"));
 }
 
 static ERL_NIF_TERM compare(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {    
-    if (argc != 2) {
-	return enif_make_badarg(env);
-    }
+    assert(argc == 2);
     return enif_make_int(env, enif_compare(argv[0],argv[1]));
 }
 
 static ERL_NIF_TERM hash_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
-    if (argc != 3) {
-        return enif_make_badarg(env);
-    }
-
     ErlNifHash type;
+    ErlNifUInt64 salt;
+
+    assert(argc == 3);
     if (enif_is_identical(argv[0], enif_make_atom(env, "internal"))) {
         type = ERL_NIF_INTERNAL_HASH;
     }
@@ -739,7 +735,6 @@ static ERL_NIF_TERM hash_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]
         return enif_make_badarg(env);
     }
 
-    ErlNifUInt64 salt;
     if (! enif_get_uint64(env, argv[2], &salt)) {
         return enif_make_badarg(env);
     }
@@ -866,7 +861,7 @@ static ERL_NIF_TERM iolist_2_bin(ErlNifEnv* env, int argc, const ERL_NIF_TERM ar
     return enif_make_binary(env,&obin);
 }
 
-static ERL_NIF_TERM last_resource_dtor_call(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+static ERL_NIF_TERM last_resource_dtor_call_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     ERL_NIF_TERM ret;
     if (resource_dtor_last != NULL) {
@@ -1010,6 +1005,7 @@ static ERL_NIF_TERM release_resource(ErlNifEnv* env, int argc, const ERL_NIF_TER
 static void* threaded_release_resource(void* resource)
 {
     enif_release_resource(resource);
+    return NULL;
 }
 
 static ERL_NIF_TERM release_resource_from_thread(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
@@ -1201,7 +1197,6 @@ static void fill(void* dst, unsigned bytes, int seed)
 enum {
     /* results */
     WHEREIS_SUCCESS,
-    WHEREIS_ERROR_TYPE,
     WHEREIS_ERROR_LOOKUP,
     WHEREIS_ERROR_SEND,
     /* types */
@@ -1221,6 +1216,8 @@ typedef struct {
     whereis_term_data_t res;
     ErlNifTid tid;
     int type;
+    int rc;
+    ERL_NIF_TERM dtor_msg;
 } whereis_thread_resource_t;
 
 static whereis_thread_resource_t* whereis_thread_resource_create(void)
@@ -1233,21 +1230,35 @@ static whereis_thread_resource_t* whereis_thread_resource_create(void)
     return rp;
 }
 
+static int whereis_lookup_internal(ErlNifEnv*, int type, ERL_NIF_TERM name,
+                                   whereis_term_data_t* out);
+static int whereis_send_internal(ErlNifEnv*, int type, whereis_term_data_t* to,
+                                 ERL_NIF_TERM msg);
+
+
 static void whereis_thread_resource_dtor(ErlNifEnv* env, void* obj)
 {
     whereis_thread_resource_t* rp = (whereis_thread_resource_t*) obj;
+    whereis_term_data_t to;
+
+    if (whereis_lookup_internal(env, rp->type, rp->name, &to)
+        == WHEREIS_SUCCESS) {
+        whereis_send_internal(env, rp->type, &to, rp->dtor_msg);
+    }
     enif_free_env(rp->env);
 }
 
-static int whereis_type(ERL_NIF_TERM type)
+static int whereis_type(ERL_NIF_TERM type_term, int* type_p)
 {
-    if (enif_is_identical(type, atom_pid))
-        return WHEREIS_LOOKUP_PID;
-
-    if (enif_is_identical(type, atom_port))
-        return WHEREIS_LOOKUP_PORT;
-
-    return WHEREIS_ERROR_TYPE;
+    if (enif_is_identical(type_term, atom_pid)) {
+        *type_p = WHEREIS_LOOKUP_PID;
+        return 1;
+    }
+    if (enif_is_identical(type_term, atom_port)) {
+        *type_p = WHEREIS_LOOKUP_PORT;
+        return 1;
+    }
+    return 0;
 }
 
 static int whereis_lookup_internal(
@@ -1261,7 +1272,7 @@ static int whereis_lookup_internal(
         return enif_whereis_port(env, name, & out->port)
             ? WHEREIS_SUCCESS : WHEREIS_ERROR_LOOKUP;
 
-    return WHEREIS_ERROR_TYPE;
+    abort();
 }
 
 static int whereis_send_internal(
@@ -1275,23 +1286,20 @@ static int whereis_send_internal(
         return enif_port_command(env, & to->port, NULL, msg)
             ? WHEREIS_SUCCESS : WHEREIS_ERROR_SEND;
 
-    return WHEREIS_ERROR_TYPE;
+    abort();
 }
 
-static int whereis_resolved_term(
-    ErlNifEnv* env, int type, whereis_term_data_t* res, ERL_NIF_TERM* out)
+static ERL_NIF_TERM whereis_resolved_term(
+    ErlNifEnv* env, int type, whereis_term_data_t* res)
 {
     switch (type) {
         case WHEREIS_LOOKUP_PID:
-            *out = enif_make_pid(env, & res->pid);
-            break;
+            return enif_make_pid(env, &res->pid);
         case WHEREIS_LOOKUP_PORT:
-            *out = enif_make_port(env, & res->port);
-            break;
+            return enif_make_port(env, &res->port);
         default:
-            return WHEREIS_ERROR_TYPE;
+            abort();
     }
-    return WHEREIS_SUCCESS;
 }
 
 static ERL_NIF_TERM whereis_result_term(ErlNifEnv* env, int result)
@@ -1307,9 +1315,6 @@ static ERL_NIF_TERM whereis_result_term(ErlNifEnv* env, int result)
         case WHEREIS_ERROR_SEND:
             err = atom_send;
             break;
-        case WHEREIS_ERROR_TYPE:
-            err = atom_badarg;
-            break;
         default:
             err = enif_make_int(env, -result);
             break;
@@ -1320,14 +1325,10 @@ static ERL_NIF_TERM whereis_result_term(ErlNifEnv* env, int result)
 static void* whereis_lookup_thread(void* arg)
 {
     whereis_thread_resource_t* rp = (whereis_thread_resource_t*) arg;
-    int rc;
 
-    /* enif_whereis_xxx should work with allocated or null env */
-    rc = whereis_lookup_internal(
-        ((rp->type == WHEREIS_LOOKUP_PID) ? NULL : rp->env),
-        rp->type, rp->name, & rp->res);
+    rp->rc = whereis_lookup_internal(NULL, rp->type, rp->name, &rp->res);
 
-    return (((char*) NULL) + rc);
+    return NULL;
 }
 
 /* whereis_term(Type, Name) -> pid() | port() | false */
@@ -1335,20 +1336,16 @@ static ERL_NIF_TERM
 whereis_term(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     whereis_term_data_t res;
-    ERL_NIF_TERM ret;
     int type, rc;
 
-    if (argc != 2)  /* allow non-atom name for testing */
-        return enif_make_badarg(env);
-
-    if ((type = whereis_type(argv[0])) == WHEREIS_ERROR_TYPE)
+    assert(argc == 2);
+    if (!whereis_type(argv[0], &type))
         return enif_make_badarg(env);
 
     rc = whereis_lookup_internal(env, type, argv[1], & res);
-    if (rc == WHEREIS_SUCCESS) {
-        rc = whereis_resolved_term(env, type, & res, & ret);
-    }
-    return (rc == WHEREIS_SUCCESS) ? ret : atom_false;
+    return (rc == WHEREIS_SUCCESS ?
+            whereis_resolved_term(env, type, &res) :
+            atom_false);
 }
 
 /* whereis_send(Type, Name, Message) -> ok | {error, Reason} */
@@ -1358,10 +1355,11 @@ whereis_send(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     whereis_term_data_t to;
     int type, rc;
 
-    if (argc != 3 || !enif_is_atom(env, argv[1]))
+    assert(argc == 3);
+    if (!enif_is_atom(env, argv[1]))
         return enif_make_badarg(env);
 
-    if ((type = whereis_type(argv[0])) == WHEREIS_ERROR_TYPE)
+    if (!whereis_type(argv[0], &type))
         return enif_make_badarg(env);
 
     rc = whereis_lookup_internal(env, type, argv[1], & to);
@@ -1371,33 +1369,35 @@ whereis_send(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     return whereis_result_term(env, rc);
 }
 
-/* whereis_thd_lookup(Type, Name) -> {ok, Resource} | {error, SysErrno} */
+/* whereis_thd_lookup(Type, Name, DtorMsg) -> {ok, Resource} | {error, SysErrno} */
 static ERL_NIF_TERM
 whereis_thd_lookup(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     whereis_thread_resource_t* rp;
     int type, rc;
+    ERL_NIF_TERM ret;
 
-    if (argc != 2 || !enif_is_atom(env, argv[1]))
+    assert(argc == 3);
+    if (!enif_is_atom(env, argv[1]))
         return enif_make_badarg(env);
 
-    if ((type = whereis_type(argv[0])) == WHEREIS_ERROR_TYPE)
+    if (!whereis_type(argv[0], &type))
         return enif_make_badarg(env);
 
     rp = whereis_thread_resource_create();
     rp->type = type;
     rp->name = enif_make_copy(rp->env, argv[1]);
+    rp->dtor_msg = enif_make_copy(rp->env, argv[2]);
 
     rc = enif_thread_create(
         "nif_SUITE:whereis_thd", & rp->tid, whereis_lookup_thread, rp, NULL);
 
-    if (rc == 0) {
-        return enif_make_tuple2(env, atom_ok, enif_make_resource(env, rp));
-    }
-    else {
-        enif_release_resource(rp);
-        return enif_make_tuple2(env, atom_error, enif_make_int(env, rc));
-    }
+    if (rc == 0)
+        ret = enif_make_tuple2(env, atom_ok, enif_make_resource(env, rp));
+    else
+        ret = enif_make_tuple2(env, atom_error, enif_make_int(env, rc));
+    enif_release_resource(rp);
+    return ret;
 }
 
 /* whereis_thd_result(Resource) -> {ok, pid() | port()} | {error, ErrNum} */
@@ -1406,24 +1406,22 @@ whereis_thd_result(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     whereis_thread_resource_t* rp;
     ERL_NIF_TERM ret;
-    char* thdret; /* so we can keep compilers happy converting to int */
-    int rc;
+    int join_rc;
 
-    if (argc != 1
-    || !enif_get_resource(env, argv[0], whereis_resource_type, (void**) & rp))
+    assert(argc == 1);
+    if (!enif_get_resource(env, argv[0], whereis_resource_type, (void**) & rp))
         return enif_make_badarg(env);
 
-    if ((rc = enif_thread_join(rp->tid, (void**) & thdret)) != 0)
-        return enif_make_tuple2(env, atom_error, enif_make_int(env, rc));
+    if ((join_rc = enif_thread_join(rp->tid, NULL)) != 0)
+        return enif_make_tuple2(env, atom_error, enif_make_int(env, join_rc));
     
-    rc = (int)(thdret - ((char*) NULL));
-    if (rc == WHEREIS_SUCCESS) {
-        rc = whereis_resolved_term(env, rp->type, & rp->res, & ret);
+    if (rp->rc == WHEREIS_SUCCESS) {
+        ret = enif_make_tuple2(env, atom_ok,
+                               whereis_resolved_term(env, rp->type, &rp->res));
     }
-    ret = (rc == WHEREIS_SUCCESS)
-        ? enif_make_tuple2(env, atom_ok, ret) : whereis_result_term(env, rc);
+    else
+        ret = whereis_result_term(env, rp->rc);
     
-    enif_release_resource(rp);
     return ret;
 }
 
@@ -1882,12 +1880,23 @@ static ERL_NIF_TERM copy_blob(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[
     return enif_make_copy(env, mti.p->blob);
 }
 
+static int get_pidbin(ErlNifEnv* env, ERL_NIF_TERM pidbin, ErlNifPid* pid)
+{
+    ErlNifBinary bin;
+
+    if (!enif_inspect_binary(env, pidbin, &bin) || bin.size != sizeof(ErlNifPid))
+        return 0;
+
+    memcpy(pid, bin.data, bin.size);
+    return 1;
+}
+
 static ERL_NIF_TERM send_term(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     ErlNifEnv* menv;
     ErlNifPid pid;
     int ret;
-    if (!enif_get_local_pid(env, argv[0], &pid)) {
+    if (!enif_get_local_pid(env, argv[0], &pid) && !get_pidbin(env, argv[0], &pid)) {
 	return enif_make_badarg(env);
     }
     menv = enif_alloc_env();
@@ -1996,8 +2005,7 @@ static ERL_NIF_TERM nif_sched1(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv
 static ERL_NIF_TERM call_nif_schedule(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     ERL_NIF_TERM result;
-    if (argc != 2)
-	return enif_make_atom(env, "false");
+    assert(argc == 2);
     result = enif_schedule_nif(env, "nif_sched1", 0, nif_sched1, argc, argv);
     assert(!enif_is_exception(env, result));
     return result;
@@ -2144,7 +2152,8 @@ static ERL_NIF_TERM maps_from_list_nif(ErlNifEnv* env, int argc, const ERL_NIF_T
     ERL_NIF_TERM result, cell;
     unsigned count;
 
-    if (argc != 1 || !enif_get_list_length(env, argv[0], &count)) {
+    assert(argc == 1);
+    if (!enif_get_list_length(env, argv[0], &count)) {
         return enif_make_badarg(env);
     }
 
@@ -2191,7 +2200,8 @@ static ERL_NIF_TERM sorted_list_from_maps_nif(ErlNifEnv* env, int argc, const ER
     ErlNifMapIterator iter_b;
     int cnt, next_ret, prev_ret;
 
-    if (argc != 1 && !enif_is_map(env, map))
+    assert(argc == 1);
+    if (!enif_is_map(env, map))
 	return enif_make_int(env, __LINE__);
 
     if(!enif_map_iterator_create(env, map, &iter_f, ERL_NIF_MAP_ITERATOR_FIRST))
@@ -2252,9 +2262,7 @@ static ERL_NIF_TERM monotonic_time(ErlNifEnv* env, int argc, const ERL_NIF_TERM
 {
     ErlNifTimeUnit time_unit;
 
-    if (argc != 1)
-	return atom_false;
-
+    assert(argc == 1);
     if (enif_compare(argv[0], atom_second) == 0)
 	time_unit = ERL_NIF_SEC;
     else if (enif_compare(argv[0], atom_millisecond) == 0)
@@ -2273,9 +2281,7 @@ static ERL_NIF_TERM time_offset(ErlNifEnv* env, int argc, const ERL_NIF_TERM arg
 {
     ErlNifTimeUnit time_unit;
 
-    if (argc != 1)
-	return atom_false;
-
+    assert(argc == 1);
     if (enif_compare(argv[0], atom_second) == 0)
 	time_unit = ERL_NIF_SEC;
     else if (enif_compare(argv[0], atom_millisecond) == 0)
@@ -2295,9 +2301,7 @@ static ERL_NIF_TERM convert_time_unit(ErlNifEnv* env, int argc, const ERL_NIF_TE
     ErlNifTime val;
     ErlNifTimeUnit from, to;
 
-    if (argc != 3)
-	return atom_false;
-
+    assert(argc == 3);
     if (!enif_get_int64(env, argv[0], &i64))
 	return enif_make_badarg(env);
 
@@ -2486,7 +2490,8 @@ static ERL_NIF_TERM select_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv
     enum ErlNifSelectFlags mode;
     void* obj;
     ErlNifPid nifpid, *pid = NULL;
-    ERL_NIF_TERM ref;
+    ERL_NIF_TERM ref_or_msg;
+    ErlNifEnv* msg_env = NULL;
     int retval;
 
     if (!get_fd(env, argv[0], &fdr)
@@ -2501,11 +2506,27 @@ static ERL_NIF_TERM select_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv
 	    return enif_make_badarg(env);
 	pid = &nifpid;
     }
-    ref = argv[4];
+    ref_or_msg = argv[4];
+    if (argv[5] != atom_null) {
+        msg_env = enif_alloc_env();
+        ref_or_msg = enif_make_copy(msg_env, ref_or_msg);
+    }
 
     fdr->was_selected = 1;
     enif_self(env, &fdr->pid);
-    retval = enif_select(env, fdr->fd, mode, obj, pid, ref);
+    switch (mode) {
+    case ERL_NIF_SELECT_CUSTOM_MSG | ERL_NIF_SELECT_READ:
+        retval = enif_select_read(env, fdr->fd, obj, pid, ref_or_msg, msg_env);
+        break;
+    case ERL_NIF_SELECT_CUSTOM_MSG | ERL_NIF_SELECT_WRITE:
+        retval = enif_select_write(env, fdr->fd, obj, pid, ref_or_msg, msg_env);
+        break;
+    default:
+        retval = enif_select(env, fdr->fd, mode, obj, pid, ref_or_msg);
+    }
+
+    if (msg_env)
+        enif_free_env(msg_env);
 
     return enif_make_int(env, retval);
 }
@@ -2830,6 +2851,16 @@ static ERL_NIF_TERM compare_monitors_nif(ErlNifEnv* env, int argc, const ERL_NIF
     return enif_make_int(env, enif_compare_monitors(&m1, &m2));
 }
 
+static ERL_NIF_TERM make_monitor_term_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    ErlNifMonitor m;
+    if (!get_monitor(env, argv[0], &m)) {
+        return enif_make_badarg(env);
+    }
+
+    return enif_make_monitor_term(env, &m);
+}
+
 
 /*********** monitor_frenzy ************/
 
@@ -3281,7 +3312,7 @@ static int writeiovec(ErlNifEnv *env, ERL_NIF_TERM term, ERL_NIF_TERM *tail, Erl
     }
 
     /* Attempt to write the data */
-    n = writev(fd, sysiovec, iovcnt);
+    n = writev(fd, (struct iovec*)sysiovec, iovcnt);
     saved_errno = errno;
 
     if (enif_ioq_size(q) == 0) {
@@ -3355,10 +3386,11 @@ static ERL_NIF_TERM ioq(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 
         if (enif_is_identical(argv[0], enif_make_atom(env, "example"))) {
 #ifndef __WIN32__
-            int fd[2], res = 0, cnt = 0, queue_cnt;
+            int fd[2], res = 0, cnt = 0;
             ERL_NIF_TERM tail;
             char buff[255];
-            pipe(fd);
+            res = pipe(fd);
+            assert(res == 0);
             fcntl(fd[0], F_SETFL, fcntl(fd[0], F_GETFL) | O_NONBLOCK);
             fcntl(fd[1], F_SETFL, fcntl(fd[1], F_GETFL) | O_NONBLOCK);
 
@@ -3486,6 +3518,95 @@ static ERL_NIF_TERM ioq(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     return enif_make_badarg(env);
 }
 
+static ERL_NIF_TERM make_bool(ErlNifEnv* env, int bool)
+{
+    return bool ? atom_true : atom_false;
+}
+
+static ERL_NIF_TERM get_local_pid_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    ErlNifPid pid;
+    ERL_NIF_TERM pid_bin;
+    int ret = enif_get_local_pid(env, argv[0], &pid);
+
+    memcpy(enif_make_new_binary(env, sizeof(ErlNifPid), &pid_bin),
+           &pid, sizeof(ErlNifPid));
+
+    return enif_make_tuple2(env, make_bool(env, ret), pid_bin);
+}
+
+static ERL_NIF_TERM make_pid_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    ErlNifPid pid;
+
+    if (!get_pidbin(env, argv[0], &pid))
+        return enif_make_badarg(env);
+
+    return enif_make_pid(env, &pid);
+}
+
+static ERL_NIF_TERM set_pid_undefined_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    ErlNifPid pid;
+    ERL_NIF_TERM pid_bin;
+
+    enif_set_pid_undefined(&pid);
+    memcpy(enif_make_new_binary(env, sizeof(ErlNifPid), &pid_bin),
+           &pid, sizeof(ErlNifPid));
+
+    return pid_bin;
+}
+
+static ERL_NIF_TERM is_pid_undefined_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    ErlNifPid pid;
+
+    if (!get_pidbin(env, argv[0], &pid))
+        return enif_make_badarg(env);
+
+    return make_bool(env, enif_is_pid_undefined(&pid));
+}
+
+static ERL_NIF_TERM compare_pids_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    ErlNifPid a, b;
+
+    if (!get_pidbin(env, argv[0], &a) || !get_pidbin(env, argv[1], &b))
+        return enif_make_badarg(env);
+
+    return enif_make_int(env, enif_compare_pids(&a, &b));
+}
+
+static ERL_NIF_TERM term_type_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    switch (enif_term_type(env, argv[0])) {
+    case ERL_NIF_TERM_TYPE_ATOM:
+        return enif_make_atom(env, "atom");
+    case ERL_NIF_TERM_TYPE_BITSTRING:
+        return enif_make_atom(env, "bitstring");
+    case ERL_NIF_TERM_TYPE_FLOAT:
+        return enif_make_atom(env, "float");
+    case ERL_NIF_TERM_TYPE_FUN:
+        return enif_make_atom(env, "fun");
+    case ERL_NIF_TERM_TYPE_INTEGER:
+        return enif_make_atom(env, "integer");
+    case ERL_NIF_TERM_TYPE_LIST:
+        return enif_make_atom(env, "list");
+    case ERL_NIF_TERM_TYPE_MAP:
+        return enif_make_atom(env, "map");
+    case ERL_NIF_TERM_TYPE_PID:
+        return enif_make_atom(env, "pid");
+    case ERL_NIF_TERM_TYPE_PORT:
+        return enif_make_atom(env, "port");
+    case ERL_NIF_TERM_TYPE_REFERENCE:
+        return enif_make_atom(env, "reference");
+    case ERL_NIF_TERM_TYPE_TUPLE:
+        return enif_make_atom(env, "tuple");
+    default:
+        return enif_make_badarg(env);
+    }
+}
+
 static ErlNifFunc nif_funcs[] =
 {
     {"lib_version", 0, lib_version},
@@ -3512,7 +3633,7 @@ static ErlNifFunc nif_funcs[] =
     {"get_resource", 2, get_resource},
     {"release_resource", 1, release_resource},
     {"release_resource_from_thread", 1, release_resource_from_thread},
-    {"last_resource_dtor_call", 0, last_resource_dtor_call},
+    {"last_resource_dtor_call_nif", 0, last_resource_dtor_call_nif},
     {"make_new_resource", 2, make_new_resource},
     {"check_is", 11, check_is},
     {"check_is_exception", 0, check_is_exception},
@@ -3565,7 +3686,7 @@ static ErlNifFunc nif_funcs[] =
     {"binary_to_term_nif", 3, binary_to_term},
     {"port_command_nif", 2, port_command},
     {"format_term_nif", 2, format_term},
-    {"select_nif", 5, select_nif},
+    {"select_nif", 6, select_nif},
 #ifndef __WIN32__
     {"pipe_nif", 0, pipe_nif},
     {"write_nif", 2, write_nif},
@@ -3579,15 +3700,22 @@ static ErlNifFunc nif_funcs[] =
     {"monitor_process_nif", 4, monitor_process_nif},
     {"demonitor_process_nif", 2, demonitor_process_nif},
     {"compare_monitors_nif", 2, compare_monitors_nif},
+    {"make_monitor_term_nif", 1, make_monitor_term_nif},
     {"monitor_frenzy_nif", 4, monitor_frenzy_nif},
     {"whereis_send", 3, whereis_send},
     {"whereis_term", 2, whereis_term},
-    {"whereis_thd_lookup", 2, whereis_thd_lookup},
+    {"whereis_thd_lookup", 3, whereis_thd_lookup},
     {"whereis_thd_result", 1, whereis_thd_result},
     {"ioq_nif", 1, ioq},
     {"ioq_nif", 2, ioq},
     {"ioq_nif", 3, ioq},
-    {"ioq_nif", 4, ioq}
+    {"ioq_nif", 4, ioq},
+    {"get_local_pid_nif", 1, get_local_pid_nif},
+    {"make_pid_nif", 1, make_pid_nif},
+    {"set_pid_undefined_nif", 0, set_pid_undefined_nif},
+    {"is_pid_undefined_nif", 1, is_pid_undefined_nif},
+    {"compare_pids_nif", 2, compare_pids_nif},
+    {"term_type_nif", 1, term_type_nif}
 };
 
 ERL_NIF_INIT(nif_SUITE,nif_funcs,load,NULL,upgrade,unload)
diff --git a/erts/emulator/test/node_container_SUITE.erl b/erts/emulator/test/node_container_SUITE.erl
index 300b4ed036..c44693f8d9 100644
--- a/erts/emulator/test/node_container_SUITE.erl
+++ b/erts/emulator/test/node_container_SUITE.erl
@@ -51,7 +51,8 @@
          unique_pid/1,
          iter_max_procs/1,
          magic_ref/1,
-         dist_entry_gc/1]).
+         dist_entry_gc/1,
+         persistent_term/1]).
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
@@ -63,7 +64,8 @@ all() ->
      node_table_gc, dist_link_refc, dist_monitor_refc,
      node_controller_refc, ets_refc, match_spec_refc,
      timer_refc, pid_wrap, port_wrap, bad_nc,
-     unique_pid, iter_max_procs, magic_ref].
+     unique_pid, iter_max_procs,
+     magic_ref, persistent_term].
 
 init_per_suite(Config) ->
     Config.
@@ -71,25 +73,10 @@ init_per_suite(Config) ->
 end_per_suite(_Config) ->
     erts_debug:set_internal_state(available_internal_state, true),
     erts_debug:set_internal_state(node_tab_delayed_delete, -1), %% restore original value
-    available_internal_state(false).
-
-available_internal_state(Bool) when Bool == true; Bool == false ->
-    case {Bool,
-          (catch erts_debug:get_internal_state(available_internal_state))} of
-        {true, true} ->
-            true;
-        {false, true} ->
-            erts_debug:set_internal_state(available_internal_state, false),
-            true;
-        {true, _} ->
-            erts_debug:set_internal_state(available_internal_state, true),
-            false;
-        {false, _} ->
-            false
-    end.
+    erts_test_utils:available_internal_state(false).
 
 init_per_testcase(_Case, Config) when is_list(Config) ->
-    available_internal_state(true),
+    erts_test_utils:available_internal_state(true),
     Config.
 
 end_per_testcase(_Case, Config) when is_list(Config) ->
@@ -585,7 +572,17 @@ node_controller_refc(Config) when is_list(Config) ->
     wait_until(fun () -> not is_process_alive(P) end),
     lists:foreach(fun (Proc) -> garbage_collect(Proc) end, processes()),
     false = get_node_references({Node,Creation}),
-    false = get_dist_references(Node),
+    wait_until(fun () ->
+                       case get_dist_references(Node) of
+                           false ->
+                               true;
+                           [{{system,thread_progress_delete_timer},
+                             [{system,1}]}] ->
+                               false;
+                           Other ->
+                               ct:fail(Other)
+                       end
+               end),
     false = lists:member(Node, nodes(known)),
     nc_refc_check(node()),
     erts_debug:set_internal_state(node_tab_delayed_delete, -1), %% restore original value
@@ -886,7 +883,22 @@ magic_ref(Config) when is_list(Config) ->
 	{'DOWN', Mon, process, Pid, _} ->
 	    ok
     end,
-    {Addr0, 2, true} = erts_debug:get_internal_state({magic_ref,MRef0}),
+    MaxTime = erlang:monotonic_time(millisecond) + 1000,
+    %% The DOWN signal is sent before heap is cleaned up,
+    %% so we might need to wait some time after the DOWN
+    %% signal has been received before the heap actually
+    %% has been cleaned up...
+    wait_until(fun () ->
+                       case erts_debug:get_internal_state({magic_ref,MRef0}) of
+                           {Addr0, 2, true} ->
+                               true;
+                           {Addr0, 3, true} ->
+                               true = MaxTime >= erlang:monotonic_time(millisecond),
+                               false;
+                           Error ->
+                               ct:fail(Error)
+                       end
+               end),
     id(MRef0),
     id(MRef1),
     MRefExt = term_to_binary(erts_debug:set_internal_state(make, magic_ref)),
@@ -896,6 +908,44 @@ magic_ref(Config) when is_list(Config) ->
     true = erts_debug:get_internal_state({magic_ref,MRef2}),
     ok.
 
+persistent_term(Config) when is_list(Config) ->
+    {ok, Node} = start_node(get_nodefirstname()),
+    Self = self(),
+    NcData = make_ref(),
+    RPid = spawn_link(Node,
+                      fun () ->
+                              Self ! {NcData, self(), hd(erlang:ports()), erlang:make_ref()}
+                      end),
+    Data = receive
+               {NcData, RPid, RPort, RRef} ->
+                   {RPid, RPort, RRef}
+           end,
+    unlink(RPid),
+    stop_node(Node),
+    Stuff = lists:foldl(fun (N, Acc) ->
+                                persistent_term:put({?MODULE, N}, Data),
+                                persistent_term:erase({?MODULE, N-1}),
+                                node_container_refc_check(node()),
+                                Data = persistent_term:get({?MODULE, N}),
+                                try
+                                    persistent_term:get({?MODULE, N-1})
+                                catch
+                                    error:badarg ->
+                                        ok
+                                end,
+                                case N rem 4 of
+                                    0 -> [persistent_term:get({?MODULE, N})|Acc];
+                                    _ -> Acc
+                                end
+                        end,
+                        [],
+                        lists:seq(1, 100)),
+    persistent_term:erase({?MODULE, 100}),
+    receive after 2000 -> ok end, %% give literal gc some time to run...
+    node_container_refc_check(node()),
+    id(Stuff),
+    ok.
+
 
 lost_pending_connection(Node) ->
     _ = (catch erts_internal:new_connection(Node)),
@@ -928,9 +978,9 @@ id(X) ->
 -define(ND_REFS, erts_debug:get_internal_state(node_and_dist_references)).
 
 node_container_refc_check(Node) when is_atom(Node) ->
-    AIS = available_internal_state(true),
+    AIS = erts_test_utils:available_internal_state(true),
     nc_refc_check(Node),
-    available_internal_state(AIS).
+    erts_test_utils:available_internal_state(AIS).
 
 nc_refc_check(Node) when is_atom(Node) ->
     Ref = make_ref(),
@@ -938,15 +988,11 @@ nc_refc_check(Node) when is_atom(Node) ->
     io:format("Starting reference count check of node ~w~n", [Node]),
     spawn_link(Node,
                fun () ->
-                       {{node_references, NodeRefs},
-                        {dist_references, DistRefs}} = ?ND_REFS,
-                       check_nd_refc({node(), erlang:system_info(creation)},
-                                     NodeRefs,
-                                     DistRefs,
-                                     fun (ErrMsg) ->
-                                             Self ! {Ref, ErrMsg, failed},
-                                             exit(normal)
-                                     end),
+                       erts_test_utils:check_node_dist(
+                         fun (ErrMsg) ->
+                                 Self ! {Ref, ErrMsg, failed},
+                                 exit(normal)
+                         end),
                        Self ! {Ref, succeded}
                end),
     receive
@@ -958,98 +1004,26 @@ nc_refc_check(Node) when is_atom(Node) ->
             ok
     end.
 
-check_nd_refc({ThisNodeName, ThisCreation}, NodeRefs, DistRefs, Fail) ->
-    case catch begin
-                   check_refc(ThisNodeName,ThisCreation,"node table",NodeRefs),
-                   check_refc(ThisNodeName,ThisCreation,"dist table",DistRefs),
-                   ok
-               end of
-        ok ->
-            ok;
-        {'EXIT', Reason} ->
-            {Y,Mo,D} = date(),
-            {H,Mi,S} = time(),
-            ErrMsg = io_lib:format("~n"
-                                   "*** Reference count check of node ~w "
-                                   "failed (~p) at ~w~w~w ~w:~w:~w~n"
-                                   "*** Node table references:~n ~p~n"
-                                   "*** Dist table references:~n ~p~n",
-                                   [node(), Reason, Y, Mo, D, H, Mi, S,
-                                    NodeRefs, DistRefs]),
-            Fail(lists:flatten(ErrMsg))
-    end.
-
-
-check_refc(ThisNodeName,ThisCreation,Table,EntryList) when is_list(EntryList) ->
-    lists:foreach(
-      fun ({Entry, Refc, ReferrerList}) ->
-              {DelayedDeleteTimer,
-               FoundRefs} =
-              lists:foldl(
-                fun ({Referrer, ReferencesList}, {DDT, A1}) ->
-                        {case Referrer of
-                             {system,delayed_delete_timer} ->
-                                 true;
-                             {system,thread_progress_delete_timer} ->
-                                 true;
-                             _ ->
-                                 DDT
-                         end,
-                         A1 + lists:foldl(fun ({_T,Rs},A2) ->
-                                                  A2+Rs
-                                          end,
-                                          0,
-                                          ReferencesList)}
-                end,
-                {false, 0},
-                ReferrerList),
-
-              %% Reference count equals found references?
-              case {Refc, FoundRefs, DelayedDeleteTimer} of
-                  {X, X, _} ->
-                      ok;
-                  {0, 1, true} ->
-                      ok;
-                  _ ->
-                      exit({invalid_reference_count, Table, Entry})
-              end,
-
-              %% All entries in table referred to?
-              case {Entry, Refc} of
-                  {ThisNodeName, 0} -> ok;
-                  {{ThisNodeName, ThisCreation}, 0} -> ok;
-                  {_, 0} when DelayedDeleteTimer == false ->
-                      exit({not_referred_entry_in_table, Table, Entry});
-                  {_, _} -> ok 
-              end
-
-      end,
-      EntryList),
-    ok.
-
 get_node_references({NodeName, Creation} = Node) when is_atom(NodeName),
                                                       is_integer(Creation) ->
     {{node_references, NodeRefs},
      {dist_references, DistRefs}} = ?ND_REFS,
-    check_nd_refc({node(), erlang:system_info(creation)},
-                  NodeRefs,
-                  DistRefs,
-                  fun (ErrMsg) ->
-                          io:format("~s", [ErrMsg]),
-                          ct:fail(reference_count_check_failed)
-                  end),
+    erts_test_utils:check_node_dist(
+      fun (ErrMsg) ->
+              io:format("~s", [ErrMsg]),
+              ct:fail(reference_count_check_failed)
+      end,
+      NodeRefs, DistRefs),
     find_references(Node, NodeRefs).
 
 get_dist_references(NodeName) when is_atom(NodeName) ->
     {{node_references, NodeRefs},
      {dist_references, DistRefs}} = ?ND_REFS,
-    check_nd_refc({node(), erlang:system_info(creation)},
-                  NodeRefs,
-                  DistRefs,
-                  fun (ErrMsg) ->
-                          io:format("~s", [ErrMsg]),
-                          ct:fail(reference_count_check_failed)
-                  end),
+    erts_test_utils:check_node_dist(fun (ErrMsg) ->
+                                            io:format("~s", [ErrMsg]),
+                                            ct:fail(reference_count_check_failed)
+                                    end,
+                                    NodeRefs, DistRefs),
     find_references(NodeName, DistRefs).
 
 find_references(N, NRefList) ->
@@ -1138,133 +1112,15 @@ get_nodename() ->
                  ++ "@"
                  ++ hostname()).
 
-
-
--define(VERSION_MAGIC,       131).
-
--define(ATOM_EXT,            100).
--define(REFERENCE_EXT,       101).
--define(PORT_EXT,            102).
--define(PID_EXT,             103).
--define(NEW_REFERENCE_EXT,   114).
--define(NEW_PID_EXT,         $X).
--define(NEW_PORT_EXT,        $Y).
--define(NEWER_REFERENCE_EXT, $Z).
-
-uint32_be(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 32 ->
-    [(Uint bsr 24) band 16#ff,
-     (Uint bsr 16) band 16#ff,
-     (Uint bsr 8) band 16#ff,
-     Uint band 16#ff];
-uint32_be(Uint) ->
-    exit({badarg, uint32_be, [Uint]}).
-
-
-uint16_be(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 16 ->
-    [(Uint bsr 8) band 16#ff,
-     Uint band 16#ff];
-uint16_be(Uint) ->
-    exit({badarg, uint16_be, [Uint]}).
-
-uint8(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 8 ->
-    Uint band 16#ff;
-uint8(Uint) ->
-    exit({badarg, uint8, [Uint]}).
-
-
-pid_tag(bad_creation) -> ?PID_EXT;
-pid_tag(Creation) when Creation =< 3 -> ?PID_EXT;
-pid_tag(_Creation) -> ?NEW_PID_EXT.
-
-enc_creation(bad_creation) -> uint8(4);
-enc_creation(Creation) when Creation =< 3 -> uint8(Creation);
-enc_creation(Creation) -> uint32_be(Creation).
-
-mk_pid({NodeName, Creation}, Number, Serial) when is_atom(NodeName) ->
-    mk_pid({atom_to_list(NodeName), Creation}, Number, Serial);
 mk_pid({NodeName, Creation}, Number, Serial) ->
-    case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
-					      pid_tag(Creation),
-					      ?ATOM_EXT,
-					      uint16_be(length(NodeName)),
-					      NodeName,
-					      uint32_be(Number),
-					      uint32_be(Serial),
-					      enc_creation(Creation)])) of
-	Pid when is_pid(Pid) ->
-	    Pid;
-	{'EXIT', {badarg, _}} ->
-	    exit({badarg, mk_pid, [{NodeName, Creation}, Number, Serial]});
-	Other ->
-	    exit({unexpected_binary_to_term_result, Other})
-    end.
+    erts_test_utils:mk_ext_pid({NodeName, Creation}, Number, Serial).
 
-port_tag(bad_creation) -> ?PORT_EXT;
-port_tag(Creation) when Creation =< 3 -> ?PORT_EXT;
-port_tag(_Creation) -> ?NEW_PORT_EXT.
-
-mk_port({NodeName, Creation}, Number) when is_atom(NodeName) ->
-    mk_port({atom_to_list(NodeName), Creation}, Number);
 mk_port({NodeName, Creation}, Number) ->
-    case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
-					      port_tag(Creation),
-					      ?ATOM_EXT,
-					      uint16_be(length(NodeName)),
-					      NodeName,
-					      uint32_be(Number),
-					      enc_creation(Creation)])) of
-	Port when is_port(Port) ->
-	    Port;
-	{'EXIT', {badarg, _}} ->
-	    exit({badarg, mk_port, [{NodeName, Creation}, Number]});
-	Other ->
-	    exit({unexpected_binary_to_term_result, Other})
-    end.
+    erts_test_utils:mk_ext_port({NodeName, Creation}, Number).
+
+mk_ref({NodeName, Creation}, Numbers) ->
+    erts_test_utils:mk_ext_ref({NodeName, Creation}, Numbers).
 
-ref_tag(bad_creation) -> ?NEW_REFERENCE_EXT;
-ref_tag(Creation) when Creation =< 3 -> ?NEW_REFERENCE_EXT;
-ref_tag(_Creation) -> ?NEWER_REFERENCE_EXT.
-
-mk_ref({NodeName, Creation}, Numbers) when is_atom(NodeName),
-					   is_list(Numbers) ->
-    mk_ref({atom_to_list(NodeName), Creation}, Numbers);
-mk_ref({NodeName, Creation}, [Number]) when is_list(NodeName),
-					    Creation =< 3,
-					    is_integer(Number) ->
-    case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
-                                              ?REFERENCE_EXT,
-                                              ?ATOM_EXT,
-                                              uint16_be(length(NodeName)),
-                                              NodeName,
-                                              uint32_be(Number),
-                                              uint8(Creation)])) of
-        Ref when is_reference(Ref) ->
-            Ref;
-        {'EXIT', {badarg, _}} ->
-            exit({badarg, mk_ref, [{NodeName, Creation}, [Number]]});
-        Other ->
-            exit({unexpected_binary_to_term_result, Other})
-    end;
-mk_ref({NodeName, Creation}, Numbers) when is_list(NodeName),
-					   is_list(Numbers) ->
-    case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
-					      ref_tag(Creation),
-					      uint16_be(length(Numbers)),
-					      ?ATOM_EXT,
-					      uint16_be(length(NodeName)),
-					      NodeName,
-					      enc_creation(Creation),
-					      lists:map(fun (N) ->
-								uint32_be(N)
-							end,
-							Numbers)])) of
-	Ref when is_reference(Ref) ->
-	    Ref;
-	{'EXIT', {badarg, _}} ->
-	    exit({badarg, mk_ref, [{NodeName, Creation}, Numbers]});
-	Other ->
-	    exit({unexpected_binary_to_term_result, Other})
-    end.
 
 exec_loop() ->
     receive
diff --git a/erts/emulator/test/num_bif_SUITE.erl b/erts/emulator/test/num_bif_SUITE.erl
index f15217814a..6b834705cf 100644
--- a/erts/emulator/test/num_bif_SUITE.erl
+++ b/erts/emulator/test/num_bif_SUITE.erl
@@ -504,6 +504,10 @@ t_integer_to_string(Config) when is_list(Config) ->
     test_its("A", 10, 16),
     test_its("D4BE", 54462, 16),
     test_its("-D4BE", -54462, 16),
+    test_its("FFFFFFFFFF", 1099511627775, 16),
+    test_its("123456789ABCDEF123456789ABCDEF123456789ABCDEF",
+             108977460683796539709587792812439445667270661579197935,
+             16),
 
     lists:foreach(fun(Value) ->
 			  {'EXIT', {badarg, _}} =
@@ -515,12 +519,14 @@ t_integer_to_string(Config) when is_list(Config) ->
     ok.
 
 test_its(List,Int) ->
-    Int = list_to_integer(List),
-    Int = binary_to_integer(list_to_binary(List)).
+    List = integer_to_list(Int),
+    Binary = list_to_binary(List),
+    Binary = integer_to_binary(Int).
 
 test_its(List,Int,Base) ->
-    Int = list_to_integer(List, Base),
-    Int = binary_to_integer(list_to_binary(List), Base).
+    List = integer_to_list(Int, Base),
+    Binary = list_to_binary(List),
+    Binary = integer_to_binary(Int, Base).
 
 %% Tests binary_to_integer/1.
 
diff --git a/erts/emulator/test/persistent_term_SUITE.erl b/erts/emulator/test/persistent_term_SUITE.erl
index 58cd3276b0..c9874e5679 100644
--- a/erts/emulator/test/persistent_term_SUITE.erl
+++ b/erts/emulator/test/persistent_term_SUITE.erl
@@ -6,7 +6,7 @@
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
 %% You may obtain a copy of the License at
-%5
+%%
 %%     http://www.apache.org/licenses/LICENSE-2.0
 %%
 %% Unless required by applicable law or agreed to in writing, software
@@ -21,11 +21,13 @@
 -module(persistent_term_SUITE).
 -include_lib("common_test/include/ct.hrl").
 
--export([all/0,suite/0,
+-export([all/0,suite/0,init_per_suite/1,end_per_suite/1,
 	 basic/1,purging/1,sharing/1,get_trapping/1,
          info/1,info_trapping/1,killed_while_trapping/1,
          off_heap_values/1,keys/1,collisions/1,
-         init_restart/1]).
+         init_restart/1, put_erase_trapping/1,
+         killed_while_trapping_put/1,
+         killed_while_trapping_erase/1]).
 
 %%
 -export([test_init_restart_cmd/1]).
@@ -37,41 +39,53 @@ suite() ->
 all() ->
     [basic,purging,sharing,get_trapping,info,info_trapping,
      killed_while_trapping,off_heap_values,keys,collisions,
-     init_restart].
+     init_restart, put_erase_trapping, killed_while_trapping_put,
+     killed_while_trapping_erase].
+
+init_per_suite(Config) ->
+    %% Put a term in the dict so that we know that the testcases handle
+    %% stray terms left by stdlib or other test suites.
+    persistent_term:put(init_per_suite, {?MODULE}),
+    Config.
+
+end_per_suite(Config) ->
+    persistent_term:erase(init_per_suite),
+    Config.
 
 basic(_Config) ->
     Chk = chk(),
     N = 777,
     Seq = lists:seq(1, N),
-    par(2, N, Seq),
-    seq(3, Seq),
-    seq(3, Seq),                                %Same values.
+    par(2, N, Seq, Chk),
+    seq(3, Seq, Chk),
+    seq(3, Seq, Chk),                                %Same values.
     _ = [begin
              Key = {?MODULE,{key,I}},
              true = persistent_term:erase(Key),
              false = persistent_term:erase(Key),
-             {'EXIT',{badarg,_}} = (catch persistent_term:get(Key))
+             {'EXIT',{badarg,_}} = (catch persistent_term:get(Key)),
+             {not_present,Key} = persistent_term:get(Key, {not_present,Key})
          end || I <- Seq],
-    [] = [P || {{?MODULE,_},_}=P <- persistent_term:get()],
+    [] = [P || {{?MODULE,_},_}=P <- pget(Chk)],
     chk(Chk).
 
-par(C, N, Seq) ->
+par(C, N, Seq, Chk) ->
     _ = [spawn_link(fun() ->
                             ok = persistent_term:put({?MODULE,{key,I}},
                                                      {value,C*I})
                     end) || I <- Seq],
-    Result = wait(N),
+    Result = wait(N, Chk),
     _ = [begin
              Double = C*I,
              {{?MODULE,{key,I}},{value,Double}} = Res
          end || {I,Res} <- lists:zip(Seq, Result)],
     ok.
 
-seq(C, Seq) ->
+seq(C, Seq, Chk) ->
     _ = [ok = persistent_term:put({?MODULE,{key,I}}, {value,C*I}) ||
             I <- Seq],
-    All = persistent_term:get(),
-    All = [P || {{?MODULE,_},_}=P <- persistent_term:get()],
+    All = pget(Chk),
+    All = [P || {{?MODULE,_},_}=P <- All],
     All = [{Key,persistent_term:get(Key)} || {Key,_} <- All],
     Result = lists:sort(All),
     _ = [begin
@@ -80,15 +94,15 @@ seq(C, Seq) ->
          end || {I,Res} <- lists:zip(Seq, Result)],
     ok.
 
-wait(N) ->
-    All = [P || {{?MODULE,_},_}=P <- persistent_term:get()],
+wait(N, Chk) ->
+    All = [P || {{?MODULE,_},_}=P <- pget(Chk)],
     case length(All) of
         N ->
             All = [{Key,persistent_term:get(Key)} || {Key,_} <- All],
             lists:sort(All);
         _ ->
             receive after 10 -> ok end,
-            wait(N)
+            wait(N, Chk)
     end.
 
 %% Make sure that terms that have been erased are copied into all
@@ -200,23 +214,23 @@ get_trapping(_Config) ->
             _ -> 1000
         end,
     spawn_link(fun() -> get_trapping_create(N) end),
-    All = do_get_trapping(N, []),
+    All = do_get_trapping(N, [], Chk),
     N = get_trapping_check_result(lists:sort(All), 1),
     erlang:garbage_collect(),
     get_trapping_erase(N),
     chk(Chk).
 
-do_get_trapping(N, Prev) ->
-    case persistent_term:get() of
+do_get_trapping(N, Prev, Chk) ->
+    case pget(Chk) of
         Prev when length(Prev) >= N ->
             All = [P || {{?MODULE,{get_trapping,_}},_}=P <- Prev],
             case length(All) of
                 N -> All;
-                _ -> do_get_trapping(N, Prev)
+                _ -> do_get_trapping(N, Prev, Chk)
             end;
         New ->
             receive after 1 -> ok end,
-            do_get_trapping(N, New)
+            do_get_trapping(N, New, Chk)
     end.
 
 get_trapping_create(0) ->
@@ -331,25 +345,25 @@ info_trapping(_Config) ->
             _ -> 1000
         end,
     spawn_link(fun() -> info_trapping_create(N) end),
-    All = do_info_trapping(N, 0),
+    All = do_info_trapping(N, 0, Chk),
     N = info_trapping_check_result(lists:sort(All), 1),
     erlang:garbage_collect(),
     info_trapping_erase(N),
     chk(Chk).
 
-do_info_trapping(N, PrevMem) ->
+do_info_trapping(N, PrevMem, Chk) ->
     case info_info() of
-        {N,Mem} ->
+        {M,Mem} when M >= N ->
             true = Mem >= PrevMem,
-            All = [P || {{?MODULE,{info_trapping,_}},_}=P <- persistent_term:get()],
+            All = [P || {{?MODULE,{info_trapping,_}},_}=P <- pget(Chk)],
             case length(All) of
                 N -> All;
-                _ -> do_info_trapping(N, PrevMem)
+                _ -> do_info_trapping(N, PrevMem, Chk)
             end;
         {_,Mem} ->
             true = Mem >= PrevMem,
             receive after 1 -> ok end,
-            do_info_trapping(N, Mem)
+            do_info_trapping(N, Mem, Chk)
     end.
 
 info_trapping_create(0) ->
@@ -462,17 +476,17 @@ collisions(_Config) ->
     _ = [V = persistent_term:get(K) || {K,V} <- Kvs],
 
     %% Now delete the persistent terms in random order.
-    collisions_delete(lists:keysort(2, Kvs)),
+    collisions_delete(lists:keysort(2, Kvs), Chk),
 
     chk(Chk).
 
-collisions_delete([{Key,Val}|Kvs]) ->
+collisions_delete([{Key,Val}|Kvs], Chk) ->
     Val = persistent_term:get(Key),
     true = persistent_term:erase(Key),
-    true = lists:sort(persistent_term:get()) =:= lists:sort(Kvs),
+    true = lists:sort(pget(Chk)) =:= lists:sort(Kvs),
     _ = [V = persistent_term:get(K) || {K,V} <- Kvs],
-    collisions_delete(Kvs);
-collisions_delete([]) ->
+    collisions_delete(Kvs, Chk);
+collisions_delete([], _) ->
     ok.
 
 colliding_keys() ->
@@ -589,15 +603,16 @@ do_test_init_restart_cmd(File) ->
 %% and after each test case.
 
 chk() ->
-    persistent_term:info().
+    {persistent_term:info(), persistent_term:get()}.
 
-chk(Chk) ->
-    Chk = persistent_term:info(),
+chk({Info, _Initial} = Chk) ->
+    Info = persistent_term:info(),
     Key = {?MODULE,?FUNCTION_NAME},
-    ok = persistent_term:put(Key, {term,Chk}),
+    ok = persistent_term:put(Key, {term,Info}),
     Term = persistent_term:get(Key),
     true = persistent_term:erase(Key),
     chk_not_stuck(Term),
+    [persistent_term:erase(K) || {K, _} <- pget(Chk)],
     ok.
 
 chk_not_stuck(Term) ->
@@ -612,3 +627,72 @@ chk_not_stuck(Term) ->
         _ ->
             ok
     end.
+
+pget({_, Initial}) ->
+    persistent_term:get() -- Initial.
+
+
+killed_while_trapping_put(_Config) ->
+    erts_debug:set_internal_state(available_internal_state, true),
+    repeat(
+      fun() ->
+              NrOfPutsInChild = 10000,
+              do_puts(2500, my_value),
+              Pid =
+                  spawn(fun() ->
+                                do_puts(NrOfPutsInChild, my_value2)
+                        end),
+              timer:sleep(1),
+              erlang:exit(Pid, kill),
+              do_erases(NrOfPutsInChild)
+      end,
+      10),
+    erts_debug:set_internal_state(available_internal_state, false).
+
+killed_while_trapping_erase(_Config) ->
+    erts_debug:set_internal_state(available_internal_state, true),
+    repeat(
+      fun() ->
+              NrOfErases = 2500,
+              do_puts(NrOfErases, my_value),
+              Pid =
+                  spawn(fun() ->
+                                do_erases(NrOfErases)
+                        end),
+              timer:sleep(1),
+              erlang:exit(Pid, kill),
+              do_erases(NrOfErases)
+      end,
+      10),
+    erts_debug:set_internal_state(available_internal_state, false).
+
+put_erase_trapping(_Config) ->
+    NrOfItems = 5000,
+    erts_debug:set_internal_state(available_internal_state, true),
+    do_puts(NrOfItems, first),
+    do_puts(NrOfItems, second),
+    do_erases(NrOfItems),
+    erts_debug:set_internal_state(available_internal_state, false).
+
+do_puts(0, _) -> ok;
+do_puts(NrOfPuts, ValuePrefix) ->
+    Key = {?MODULE, NrOfPuts},
+    Value = {ValuePrefix, NrOfPuts},
+    erts_debug:set_internal_state(reds_left, rand:uniform(250)),
+    persistent_term:put(Key, Value),
+    Value = persistent_term:get(Key),
+    do_puts(NrOfPuts - 1, ValuePrefix).
+
+do_erases(0) -> ok;
+do_erases(NrOfErases) ->
+    Key = {?MODULE,NrOfErases},
+    erts_debug:set_internal_state(reds_left, rand:uniform(500)),
+    persistent_term:erase(Key),
+    not_found = persistent_term:get(Key, not_found),
+    do_erases(NrOfErases - 1).
+
+repeat(_Fun, 0) ->
+    ok;
+repeat(Fun, N) ->
+    Fun(),
+    repeat(Fun, N-1).
diff --git a/erts/emulator/test/process_SUITE.erl b/erts/emulator/test/process_SUITE.erl
index 57eb082d64..13dde12e69 100644
--- a/erts/emulator/test/process_SUITE.erl
+++ b/erts/emulator/test/process_SUITE.erl
@@ -44,6 +44,7 @@
          process_info_garbage_collection/1,
          process_info_smoke_all/1,
          process_info_status_handled_signal/1,
+         process_info_reductions/1,
 	 bump_reductions/1, low_prio/1, binary_owner/1, yield/1, yield2/1,
 	 otp_4725/1, bad_register/1, garbage_collect/1, otp_6237/1,
 	 process_info_messages/1, process_flag_badarg/1, process_flag_heap_size/1,
@@ -84,6 +85,7 @@ all() ->
      process_info_garbage_collection,
      process_info_smoke_all,
      process_info_status_handled_signal,
+     process_info_reductions,
      bump_reductions, low_prio, yield, yield2, otp_4725,
      bad_register, garbage_collect, process_info_messages,
      process_flag_badarg, process_flag_heap_size,
@@ -133,6 +135,15 @@ init_per_group(_GroupName, Config) ->
 end_per_group(_GroupName, Config) ->
     Config.
 
+init_per_testcase(Func, Config)
+  when Func =:= processes_default_tab;
+       Func =:= processes_this_tab ->
+    case erlang:system_info(debug_compiled) of
+        true ->
+            {skip, "Don't run in debug"};
+        false ->
+            [{testcase, Func} | Config]
+    end;
 init_per_testcase(Func, Config) when is_atom(Func), is_list(Config) ->
     [{testcase, Func}|Config].
 
@@ -1084,6 +1095,90 @@ process_info_status_handled_signal(Config) when is_list(Config) ->
     false = erlang:is_process_alive(P),
     ok.
 
+%% OTP-15709
+%% Provoke a bug where process_info(reductions) returned wrong result
+%% because REDS_IN (def_arg_reg[5]) is read when the process in not running.
+%%
+%% And a bug where process_info(reductions) on a process which was releasing its
+%% main lock during execution could result in negative reduction diffs.
+process_info_reductions(Config) when is_list(Config) ->
+    {S1, S2} = case erlang:system_info(schedulers) of
+                   1 -> {1,1};
+                   _ -> {1,2}
+               end,
+    io:format("Run on schedulers ~p and ~p\n", [S1,S2]),
+    Boss = self(),
+    Doer = spawn_opt(fun () ->
+                             pi_reductions_tester(true, 10, fun pi_reductions_spinnloop/0, S2),
+                             pi_reductions_tester(true, 10, fun pi_reductions_recvloop/0, S2),
+                             pi_reductions_tester(false, 100, fun pi_reductions_main_unlocker/0, S2),
+                             Boss ! {self(), done}
+                     end,
+                     [link, {scheduler, S1}]),
+
+    {Doer, done} = receive M -> M end,
+    ok.
+
+pi_reductions_tester(ForceSignal, MaxCalls, Fun, S2) ->
+    Pid = spawn_opt(Fun, [link, {scheduler,S2}]),
+    Extra = case ForceSignal of
+                true ->
+                    %% Add another item that force sending the request
+                    %% as a signal, like 'current_function'.
+                    [current_function];
+                false ->
+                    []
+            end,
+    LoopFun = fun Me(Calls, Prev, Acc0) ->
+                      PI = process_info(Pid, [reductions | Extra]),
+                      [{reductions,Reds} | _] = PI,
+                      Diff = Reds - Prev,
+                      %% Verify we get sane non-negative reduction diffs
+                      {Diff, true} = {Diff, (Diff >= 0)},
+                      {Diff, true} = {Diff, (Diff =< 1000*1000)},
+                      Acc1 = [Diff | Acc0],
+                      case Calls >= MaxCalls of
+                          true -> Acc1;
+                          false -> Me(Calls+1, Reds, Acc1)
+                      end
+              end,
+    DiffList = LoopFun(0, 0, []),
+    unlink(Pid),
+    exit(Pid,kill),
+    io:format("Reduction diffs: ~p\n", [lists:reverse(DiffList)]),
+    ok.
+
+pi_reductions_spinnloop() ->
+    %% 6 args to make use of def_arg_reg[5] which is also used as REDS_IN
+    pi_reductions_spinnloop(999*1000, atom, "hej", self(), make_ref(), 3.14).
+
+pi_reductions_spinnloop(N,A,B,C,D,E) when N > 0 ->
+    pi_reductions_spinnloop(N-1,B,C,D,E,A);
+pi_reductions_spinnloop(0,_,_,_,_,_) ->
+    %% Stop to limit max number of reductions consumed
+    pi_reductions_recvloop().
+
+pi_reductions_recvloop() ->
+    receive
+        "a free lunch" -> false
+    end.
+
+pi_reductions_main_unlocker() ->
+    Other = spawn_link(fun() -> receive die -> ok end end),
+    pi_reductions_main_unlocker_loop(Other).
+
+pi_reductions_main_unlocker_loop(Other) ->
+    %% Assumption: register(OtherPid, Name) will unlock main lock of calling
+    %% process during execution.
+    register(pi_reductions_main_unlocker, Other),
+    unregister(pi_reductions_main_unlocker),
+
+    %% Yield in order to increase probability of process_info sometimes probing
+    %% this process when it's not RUNNING.
+    erlang:yield(),
+    pi_reductions_main_unlocker_loop(Other).
+
+
 %% Tests erlang:bump_reductions/1.
 bump_reductions(Config) when is_list(Config) ->
     erlang:garbage_collect(),
@@ -2104,6 +2199,13 @@ spawn_opt_max_heap_size(_Config) ->
 
     error_logger:add_report_handler(?MODULE, self()),
 
+    %% flush any prior messages in error_logger
+    Pid = spawn(fun() -> ok = nok end),
+    receive
+        {error, _, {emulator, _, [Pid|_]}} ->
+            flush()
+    end,
+
     %% Test that numerical limit works
     max_heap_size_test(1024, 1024, true, true),
 
@@ -2208,6 +2310,13 @@ receive_unexpected() ->
             ok
     end.
 
+flush() ->
+    receive
+        _M -> flush()
+    after 0 ->
+            ok
+    end.
+
 %% error_logger report handler proxy
 init(Pid) ->
     {ok, Pid}.
@@ -2233,8 +2342,8 @@ processes_term_proc_list(Config) when is_list(Config) ->
     %% We have to run this test case with +S1 since instrument:allocations()
     %% will report a free()'d block as present until it's actually deallocated
     %% by its employer.
-    Run("+MSe true +MSatags false +S1"),
-    Run("+MSe true +MSatags true +S1"),
+    Run("+MSe true +Muatags false +S1"),
+    Run("+MSe true +Muatags true +S1"),
 
     ok.
 
@@ -2242,10 +2351,12 @@ processes_term_proc_list(Config) when is_list(Config) ->
 	chk_term_proc_list(?LINE, MC, XB)).
 
 chk_term_proc_list(Line, MustChk, ExpectBlks) ->
-    Allocs = instrument:allocations(#{ allocator_types => [sl_alloc] }),
+    Allocs = instrument:allocations(),
     case {MustChk, Allocs} of
 	{false, {error, not_enabled}} ->
 	    not_enabled;
+	{false, {ok, {_Shift, _Unscanned, ByOrigin}}} when ByOrigin =:= #{} ->
+	    not_enabled;
 	{_, {ok, {_Shift, _Unscanned, ByOrigin}}} ->
             ByType = maps:get(system, ByOrigin, #{}),
             Hist = maps:get(ptab_list_deleted_el, ByType, {}),
@@ -2489,14 +2600,20 @@ garb_other_running(Config) when is_list(Config) ->
 
 no_priority_inversion(Config) when is_list(Config) ->
     Prio = process_flag(priority, max),
-    HTLs = lists:map(fun (_) ->
+    Master = self(),
+    Executing = make_ref(),
+    HTLs = lists:map(fun (Sched) ->
 			     spawn_opt(fun () ->
+                                               Master ! {self(), Executing},
 					       tok_loop()
 				       end,
-				       [{priority, high}, monitor, link])
+				       [{priority, high},
+                                        {scheduler, Sched},
+                                        monitor,
+                                        link])
 		     end,
-		     lists:seq(1, 2*erlang:system_info(schedulers))),
-    receive after 500 -> ok end,
+		     lists:seq(1, erlang:system_info(schedulers_online))),
+    lists:foreach(fun ({P, _}) -> receive {P,Executing} -> ok end end, HTLs),
     LTL = spawn_opt(fun () ->
 			    tok_loop()
 		    end,
@@ -2518,14 +2635,19 @@ no_priority_inversion(Config) when is_list(Config) ->
 
 no_priority_inversion2(Config) when is_list(Config) ->
     Prio = process_flag(priority, max),
-    MTLs = lists:map(fun (_) ->
+    Master = self(),
+    Executing = make_ref(),
+    MTLs = lists:map(fun (Sched) ->
 			     spawn_opt(fun () ->
+                                               Master ! {self(), Executing},
 					       tok_loop()
 				       end,
-				       [{priority, max}, monitor, link])
+				       [{priority, max},
+                                        {scheduler, Sched},
+                                        monitor, link])
 		     end,
-		     lists:seq(1, 2*erlang:system_info(schedulers))),
-    receive after 2000 -> ok end,
+		     lists:seq(1, erlang:system_info(schedulers_online))),
+    lists:foreach(fun ({P, _}) -> receive {P,Executing} -> ok end end, MTLs),
     {PL, ML} = spawn_opt(fun () ->
 			       tok_loop()
 		       end,
diff --git a/erts/emulator/test/scheduler_SUITE.erl b/erts/emulator/test/scheduler_SUITE.erl
index 2e0dfa42f3..f61949c75b 100644
--- a/erts/emulator/test/scheduler_SUITE.erl
+++ b/erts/emulator/test/scheduler_SUITE.erl
@@ -1450,28 +1450,26 @@ poll_threads(Config) when is_list(Config) ->
     {Conc, PollType, KP} = get_ioconfig(Config),
     {Sched, SchedOnln, _} = get_sstate(Config, ""),
 
+    [1, 1] = get_ionum(Config,"+IOt 2 +IOp 2"),
+    [1, 1, 1, 1, 1] = get_ionum(Config,"+IOt 5 +IOp 5"),
+    [1, 1] = get_ionum(Config, "+S 2 +IOPt 100 +IOPp 100"),
+
     if
         Conc ->
-            [1, 1, 1] = get_ionum(Config,"+IOt 2 +IOp 2"),
-            [1, 1, 1, 1, 1, 1] = get_ionum(Config,"+IOt 5 +IOp 5"),
-            [1, 1, 1] = get_ionum(Config, "+S 2 +IOPt 100 +IOPp 100"),
 
-            [5, 1] = get_ionum(Config,"+IOt 5 +IOp 1"),
-            [3, 2, 1] = get_ionum(Config,"+IOt 5 +IOp 2"),
-            [2, 2, 2, 2, 2, 1] = get_ionum(Config,"+IOt 10 +IOPp 50"),
+            [5] = get_ionum(Config,"+IOt 5 +IOp 1"),
+            [3, 2] = get_ionum(Config,"+IOt 5 +IOp 2"),
+            [2, 2, 2, 2, 2] = get_ionum(Config,"+IOt 10 +IOPp 50"),
 
-            [2, 1] = get_ionum(Config, "+S 2 +IOPt 100"),
-            [4, 1] = get_ionum(Config, "+S 4 +IOPt 100"),
-            [4, 1] = get_ionum(Config, "+S 4:2 +IOPt 100"),
-            [4, 4, 1] = get_ionum(Config, "+S 8 +IOPt 100 +IOPp 25"),
+            [2] = get_ionum(Config, "+S 2 +IOPt 100"),
+            [4] = get_ionum(Config, "+S 4 +IOPt 100"),
+            [4] = get_ionum(Config, "+S 4:2 +IOPt 100"),
+            [4, 4] = get_ionum(Config, "+S 8 +IOPt 100 +IOPp 25"),
 
             fail = get_ionum(Config, "+IOt 1 +IOp 2"),
 
             ok;
         not Conc ->
-            [1, 1] = get_ionum(Config,"+IOt 2 +IOp 2"),
-            [1, 1, 1, 1, 1] = get_ionum(Config,"+IOt 5 +IOp 5"),
-            [1, 1] = get_ionum(Config, "+S 2 +IOPt 100 +IOPp 100"),
 
             [1, 1, 1, 1, 1] = get_ionum(Config,"+IOt 5 +IOp 1"),
             [1, 1, 1, 1, 1] = get_ionum(Config,"+IOt 5 +IOp 2"),
@@ -1515,7 +1513,8 @@ get_iostate(Config, Cmd)->
                                              erlang:system_info(check_io)
                                      end]),
             IO = [IOState || IOState <- IOStates,
-                             proplists:get_value(fallback, IOState) == false],
+                             proplists:get_value(fallback, IOState) == false,
+                             proplists:get_value(poll_threads, IOState) /= 0],
             stop_node(Node),
             IO;
         {error,timeout} ->
diff --git a/erts/emulator/test/small_SUITE.erl b/erts/emulator/test/small_SUITE.erl
new file mode 100644
index 0000000000..00a02e5560
--- /dev/null
+++ b/erts/emulator/test/small_SUITE.erl
@@ -0,0 +1,115 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2019. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(small_SUITE).
+
+-export([all/0, suite/0]).
+-export([edge_cases/1]).
+
+-include_lib("common_test/include/ct.hrl").
+
+suite() ->
+    [{ct_hooks,[ts_install_cth]},
+     {timetrap, {minutes, 1}}].
+
+all() ->
+    [edge_cases].
+
+edge_cases(Config) when is_list(Config) ->
+    {MinSmall, MaxSmall} = Limits = determine_small_limits(0),
+    ct:pal("Limits = ~p", [Limits]),
+
+    true = (MaxSmall + 1) =:= MaxSmall + id(1),
+    true = (MinSmall - 1) =:= MinSmall - id(1),
+    true = (MaxSmall + 1) > id(MaxSmall),
+    true = (MinSmall - 1) < id(MinSmall),
+    -1 = MinSmall + id(MaxSmall),
+    -1 = MaxSmall + id(MinSmall),
+
+    false = is_small(MinSmall * -1),
+    false = is_small(MinSmall - id(1)),
+    false = is_small(MinSmall - 1),
+    false = is_small(MaxSmall + id(1)),
+
+    Lower = lists:seq(MinSmall, MinSmall + 128),
+    Upper = lists:seq(MaxSmall, MaxSmall - 128, -1),
+    Pow2 = seq_pow2(MinSmall, MaxSmall),
+    NearZero = lists:seq(-128, 128),
+
+    ok = test_combinations([Lower, Upper, Pow2, NearZero], MinSmall, MaxSmall),
+
+    ok.
+
+test_combinations([As | Rest]=TestVectors, MinS, MaxS) ->
+    [begin
+        _ = [arith_test(A, B, MinS, MaxS) || B <- Bs]
+     end || A <- As, Bs <- TestVectors],
+    test_combinations(Rest, MinS, MaxS);
+test_combinations([], _MinS, _MaxS) ->
+    ok.
+
+%% Builds a sequence of all powers of 2 between MinSmall and MaxSmall
+seq_pow2(MinSmall, MaxSmall) ->
+    sp2_1(MinSmall, MinSmall, MaxSmall).
+
+sp2_1(N, _MinS, MaxS) when N >= MaxS ->
+    [];
+sp2_1(-1, MinS, MaxS) ->
+    [-1 | sp2_1(1, MinS, MaxS)];
+sp2_1(N, MinS, MaxS) when N < 0 ->
+    [N | sp2_1(N bsr 1, MinS, MaxS)];
+sp2_1(N, MinS, MaxS) when N > 0 ->
+    [N | sp2_1(N bsl 1, MinS, MaxS)].
+
+arith_test(A, B, MinS, MaxS) ->
+    verify_kind(A + B, MinS, MaxS),
+    verify_kind(B + A, MinS, MaxS),
+    verify_kind(A - B, MinS, MaxS),
+    verify_kind(B - A, MinS, MaxS),
+    verify_kind(A * B, MinS, MaxS),
+    verify_kind(B * A, MinS, MaxS),
+
+    true = A + B =:= apply(erlang, id('+'), [A, B]),
+    true = A - B =:= apply(erlang, id('-'), [A, B]),
+    true = A * B =:= apply(erlang, id('*'), [A, B]),
+
+    true = A + B =:= B + id(A),
+    true = A - B =:= A + id(-B),
+    true = B - A =:= B + id(-A),
+    true = A * B =:= B * id(A),
+
+    true = B =:= 0 orelse ((A * B) div id(B) =:= A),
+    true = A =:= 0 orelse ((B * A) div id(A) =:= B),
+
+    ok.
+
+%% Verifies that N is a small when it should be
+verify_kind(N, MinS, MaxS) ->
+    true = is_small(N) =:= (N >= MinS andalso N =< MaxS).
+
+is_small(N) when is_integer(N) ->
+    0 =:= erts_debug:flat_size(N).
+
+determine_small_limits(N) ->
+    case is_small(-1 bsl N) of
+        true -> determine_small_limits(N + 1);
+        false -> {-1 bsl (N - 1), (1 bsl (N - 1)) - 1}
+    end.
+
+id(I) -> I.
diff --git a/erts/emulator/test/smoke_test_SUITE.erl b/erts/emulator/test/smoke_test_SUITE.erl
index 26c610e3a8..5b46342127 100644
--- a/erts/emulator/test/smoke_test_SUITE.erl
+++ b/erts/emulator/test/smoke_test_SUITE.erl
@@ -56,7 +56,7 @@ end_per_testcase(_Case, Config) when is_list(Config) ->
 %%%
 
 boot_combo(Config) when is_list(Config) ->
-    ZFlags = os:getenv("ERL_ZFLAGS"),
+    ZFlags = os:getenv("ERL_ZFLAGS", ""),
     NOOP = fun () -> ok end,
     A42 = fun () ->
 		  case erlang:system_info(threads) of
@@ -87,10 +87,7 @@ boot_combo(Config) when is_list(Config) ->
 	%% A lot more combos could be implemented...
 	ok
     after
-	os:putenv("ERL_ZFLAGS", case ZFlags of
-				    false -> "";
-				    _ -> ZFlags
-				end)
+	os:putenv("ERL_ZFLAGS", ZFlags)
     end.
 
 native_atomics(Config) when is_list(Config) ->
diff --git a/erts/emulator/test/socket_SUITE.erl b/erts/emulator/test/socket_SUITE.erl
new file mode 100644
index 0000000000..4980ea2a82
--- /dev/null
+++ b/erts/emulator/test/socket_SUITE.erl
@@ -0,0 +1,29159 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+%% There are some environment variables that can be used to "manipulate"
+%% the test suite: 
+%%
+%% Variable that controls which 'groups' are to run (with default values)
+%%
+%%         ESOCK_TEST_API:         include
+%%         ESOCK_TEST_SOCK_CLOSE:  include
+%%         ESOCK_TEST_TRAFFIC:     include
+%%         ESOCK_TEST_TTEST:       exclude
+%%
+%% Variable that controls "verbosity" of the test case(s):
+%%
+%%         ESOCK_TEST_QUIET: true (default) | false
+%%
+%% Defines the runtime of the ttest cases
+%% (This is the time during which "measurement" is performed. 
+%%  the actual time it takes for the test case to complete
+%%  will be longer; setup, completion, ...)
+%%
+%%          ESOCK_TEST_TTEST_RUNTIME: 10 seconds
+%%              Format of values: <integer>[<unit>]
+%%              Where unit is: ms | s | m
+%%                 ms - milli seconds
+%%                 s  - seconds (default)
+%%                 m  - minutes
+%%
+
+%% Run the entire test suite: 
+%% ts:run(emulator, socket_SUITE, [batch]).
+%%
+%% Run a specific group:
+%% ts:run(emulator, socket_SUITE, {group, foo}, [batch]).
+%%
+%% Run a specific test case:
+%% ts:run(emulator, socket_SUITE, foo, [batch]).
+
+-module(socket_SUITE).
+
+-include_lib("common_test/include/ct.hrl").
+-include_lib("common_test/include/ct_event.hrl").
+-include("socket_test_evaluator.hrl").
+
+%% Suite exports
+-export([suite/0, all/0, groups/0]).
+-export([init_per_suite/1,    end_per_suite/1,
+         init_per_group/2,    end_per_group/2,
+         init_per_testcase/2, end_per_testcase/2]).
+
+%% Test cases
+-export([
+         %% *** API Misc ***
+         api_m_debug/1,
+
+         %% *** API Basic ***
+         api_b_open_and_close_udp4/1,
+         api_b_open_and_close_tcp4/1,
+         api_b_open_and_close_udpL/1,
+         api_b_open_and_close_tcpL/1,
+         api_b_sendto_and_recvfrom_udp4/1,
+         api_b_sendto_and_recvfrom_udpL/1,
+         api_b_sendmsg_and_recvmsg_udp4/1,
+         api_b_sendmsg_and_recvmsg_udpL/1,
+         api_b_send_and_recv_tcp4/1,
+         api_b_send_and_recv_tcpL/1,
+         api_b_sendmsg_and_recvmsg_tcp4/1,
+         api_b_sendmsg_and_recvmsg_tcpL/1,
+
+         %% *** API async ***
+         api_a_connect_tcp4/1,
+         api_a_connect_tcp6/1,
+         api_a_sendto_and_recvfrom_udp4/1,
+         api_a_sendto_and_recvfrom_udp6/1,
+         api_a_sendmsg_and_recvmsg_udp4/1,
+         api_a_sendmsg_and_recvmsg_udp6/1,
+         api_a_send_and_recv_tcp4/1,
+         api_a_send_and_recv_tcp6/1,
+         api_a_sendmsg_and_recvmsg_tcp4/1,
+         api_a_sendmsg_and_recvmsg_tcp6/1,
+         api_a_recvfrom_cancel_udp4/1,
+         api_a_recvfrom_cancel_udp6/1,
+         api_a_recvmsg_cancel_udp4/1,
+         api_a_recvmsg_cancel_udp6/1,
+         api_a_accept_cancel_tcp4/1,
+         api_a_accept_cancel_tcp6/1,
+         api_a_recv_cancel_tcp4/1,
+         api_a_recv_cancel_tcp6/1,
+         api_a_recvmsg_cancel_tcp4/1,
+         api_a_recvmsg_cancel_tcp6/1,
+         api_a_mrecvfrom_cancel_udp4/1,
+         api_a_mrecvfrom_cancel_udp6/1,
+         api_a_mrecvmsg_cancel_udp4/1,
+         api_a_mrecvmsg_cancel_udp6/1,
+         api_a_maccept_cancel_tcp4/1,
+         api_a_maccept_cancel_tcp6/1,
+         api_a_mrecv_cancel_tcp4/1,
+         api_a_mrecv_cancel_tcp6/1,
+         api_a_mrecvmsg_cancel_tcp4/1,
+         api_a_mrecvmsg_cancel_tcp6/1,
+
+
+         %% *** API Options ***
+         api_opt_simple_otp_options/1,
+         api_opt_simple_otp_rcvbuf_option/1,
+         api_opt_simple_otp_controlling_process/1,
+         api_opt_sock_acceptconn_udp/1,
+         api_opt_sock_acceptconn_tcp/1,
+         api_opt_sock_acceptfilter/1,
+         api_opt_sock_bindtodevice/1,
+         api_opt_sock_broadcast/1,
+         api_opt_sock_debug/1,
+         api_opt_sock_domain/1,
+         api_opt_sock_dontroute/1,
+         api_opt_sock_error/1,
+         api_opt_sock_keepalive/1,
+         api_opt_sock_linger/1,
+         api_opt_ip_add_drop_membership/1,
+
+         %% *** API Operation Timeout ***
+         api_to_connect_tcp4/1,
+         api_to_connect_tcp6/1,
+         api_to_accept_tcp4/1,
+         api_to_accept_tcp6/1,
+         api_to_maccept_tcp4/1,
+         api_to_maccept_tcp6/1,
+         api_to_send_tcp4/1,
+         api_to_send_tcp6/1,
+         api_to_sendto_udp4/1,
+         api_to_sendto_udp6/1,
+         api_to_sendmsg_tcp4/1,
+         api_to_sendmsg_tcp6/1,
+         api_to_recv_udp4/1,
+         api_to_recv_udp6/1,
+         api_to_recv_tcp4/1,
+         api_to_recv_tcp6/1,
+         api_to_recvfrom_udp4/1,
+         api_to_recvfrom_udp6/1,
+         api_to_recvmsg_udp4/1,
+         api_to_recvmsg_udp6/1,
+         api_to_recvmsg_tcp4/1,
+         api_to_recvmsg_tcp6/1,
+
+         %% *** Socket Closure ***
+         sc_cpe_socket_cleanup_tcp4/1,
+         sc_cpe_socket_cleanup_tcp6/1,
+         sc_cpe_socket_cleanup_tcpL/1,
+         sc_cpe_socket_cleanup_udp4/1,
+         sc_cpe_socket_cleanup_udp6/1,
+         sc_cpe_socket_cleanup_udpL/1,
+
+         sc_lc_recv_response_tcp4/1,
+         sc_lc_recv_response_tcp6/1,
+         sc_lc_recv_response_tcpL/1,
+         sc_lc_recvfrom_response_udp4/1,
+         sc_lc_recvfrom_response_udp6/1,
+         sc_lc_recvfrom_response_udpL/1,
+         sc_lc_recvmsg_response_tcp4/1,
+         sc_lc_recvmsg_response_tcp6/1,
+         sc_lc_recvmsg_response_tcpL/1,
+         sc_lc_recvmsg_response_udp4/1,
+         sc_lc_recvmsg_response_udp6/1,
+         sc_lc_recvmsg_response_udpL/1,
+         sc_lc_acceptor_response_tcp4/1,
+         sc_lc_acceptor_response_tcp6/1,
+         sc_lc_acceptor_response_tcpL/1,
+
+         sc_rc_recv_response_tcp4/1,
+         sc_rc_recv_response_tcp6/1,
+         sc_rc_recv_response_tcpL/1,
+         sc_rc_recvmsg_response_tcp4/1,
+         sc_rc_recvmsg_response_tcp6/1,
+         sc_rc_recvmsg_response_tcpL/1,
+
+         sc_rs_recv_send_shutdown_receive_tcp4/1,
+         sc_rs_recv_send_shutdown_receive_tcp6/1,
+         sc_rs_recv_send_shutdown_receive_tcpL/1,
+         sc_rs_recvmsg_send_shutdown_receive_tcp4/1,
+         sc_rs_recvmsg_send_shutdown_receive_tcp6/1,
+         sc_rs_recvmsg_send_shutdown_receive_tcpL/1,
+
+         %% *** Traffic ***
+         traffic_send_and_recv_counters_tcp4/1,
+         traffic_send_and_recv_counters_tcp6/1,
+         traffic_send_and_recv_counters_tcpL/1,
+         traffic_sendmsg_and_recvmsg_counters_tcp4/1,
+         traffic_sendmsg_and_recvmsg_counters_tcp6/1,
+         traffic_sendmsg_and_recvmsg_counters_tcpL/1,
+         traffic_sendto_and_recvfrom_counters_udp4/1,
+         traffic_sendto_and_recvfrom_counters_udp6/1,
+         traffic_sendto_and_recvfrom_counters_udpL/1,
+         traffic_sendmsg_and_recvmsg_counters_udp4/1,
+         traffic_sendmsg_and_recvmsg_counters_udp6/1,
+         traffic_sendmsg_and_recvmsg_counters_udpL/1,
+
+         traffic_send_and_recv_chunks_tcp4/1,
+         traffic_send_and_recv_chunks_tcp6/1,
+         traffic_send_and_recv_chunks_tcpL/1,
+
+         traffic_ping_pong_small_send_and_recv_tcp4/1,
+         traffic_ping_pong_small_send_and_recv_tcp6/1,
+         traffic_ping_pong_small_send_and_recv_tcpL/1,
+         traffic_ping_pong_medium_send_and_recv_tcp4/1,
+         traffic_ping_pong_medium_send_and_recv_tcp6/1,
+         traffic_ping_pong_medium_send_and_recv_tcpL/1,
+         traffic_ping_pong_large_send_and_recv_tcp4/1,
+         traffic_ping_pong_large_send_and_recv_tcp6/1,
+         traffic_ping_pong_large_send_and_recv_tcpL/1,
+
+         traffic_ping_pong_small_sendto_and_recvfrom_udp4/1,
+         traffic_ping_pong_small_sendto_and_recvfrom_udp6/1,
+         traffic_ping_pong_small_sendto_and_recvfrom_udpL/1,
+         traffic_ping_pong_medium_sendto_and_recvfrom_udp4/1,
+         traffic_ping_pong_medium_sendto_and_recvfrom_udp6/1,
+         traffic_ping_pong_medium_sendto_and_recvfrom_udpL/1,
+
+         traffic_ping_pong_small_sendmsg_and_recvmsg_tcp4/1,
+         traffic_ping_pong_small_sendmsg_and_recvmsg_tcp6/1,
+         traffic_ping_pong_small_sendmsg_and_recvmsg_tcpL/1,
+         traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp4/1,
+         traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp6/1,
+         traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL/1,
+         traffic_ping_pong_large_sendmsg_and_recvmsg_tcp4/1,
+         traffic_ping_pong_large_sendmsg_and_recvmsg_tcp6/1,
+         traffic_ping_pong_large_sendmsg_and_recvmsg_tcpL/1,
+
+         traffic_ping_pong_small_sendmsg_and_recvmsg_udp4/1,
+         traffic_ping_pong_small_sendmsg_and_recvmsg_udp6/1,
+         traffic_ping_pong_small_sendmsg_and_recvmsg_udpL/1,
+         traffic_ping_pong_medium_sendmsg_and_recvmsg_udp4/1,
+         traffic_ping_pong_medium_sendmsg_and_recvmsg_udp6/1,
+         traffic_ping_pong_medium_sendmsg_and_recvmsg_udpL/1,
+
+         %% *** Time Test ***
+         %% Server: transport = gen_tcp, active = false
+         %% Client: transport = gen_tcp
+         ttest_sgenf_cgenf_small_tcp4/1,
+         ttest_sgenf_cgenf_small_tcp6/1,
+         ttest_sgenf_cgenf_medium_tcp4/1,
+         ttest_sgenf_cgenf_medium_tcp6/1,
+         ttest_sgenf_cgenf_large_tcp4/1,
+         ttest_sgenf_cgenf_large_tcp6/1,
+
+         ttest_sgenf_cgeno_small_tcp4/1,
+         ttest_sgenf_cgeno_small_tcp6/1,
+         ttest_sgenf_cgeno_medium_tcp4/1,
+         ttest_sgenf_cgeno_medium_tcp6/1,
+         ttest_sgenf_cgeno_large_tcp4/1,
+         ttest_sgenf_cgeno_large_tcp6/1,
+
+         ttest_sgenf_cgent_small_tcp4/1,
+         ttest_sgenf_cgent_small_tcp6/1,
+         ttest_sgenf_cgent_medium_tcp4/1,
+         ttest_sgenf_cgent_medium_tcp6/1,
+         ttest_sgenf_cgent_large_tcp4/1,
+         ttest_sgenf_cgent_large_tcp6/1,
+
+         %% Server: transport = gen_tcp, active = false
+         %% Client: transport = socket(tcp)
+         ttest_sgenf_csockf_small_tcp4/1,
+         ttest_sgenf_csockf_small_tcp6/1,
+         ttest_sgenf_csockf_medium_tcp4/1,
+         ttest_sgenf_csockf_medium_tcp6/1,
+         ttest_sgenf_csockf_large_tcp4/1,
+         ttest_sgenf_csockf_large_tcp6/1,
+
+         ttest_sgenf_csocko_small_tcp4/1,
+         ttest_sgenf_csocko_small_tcp6/1,
+         ttest_sgenf_csocko_medium_tcp4/1,
+         ttest_sgenf_csocko_medium_tcp6/1,
+         ttest_sgenf_csocko_large_tcp4/1,
+         ttest_sgenf_csocko_large_tcp6/1,
+
+         ttest_sgenf_csockt_small_tcp4/1,
+         ttest_sgenf_csockt_small_tcp6/1,
+         ttest_sgenf_csockt_medium_tcp4/1,
+         ttest_sgenf_csockt_medium_tcp6/1,
+         ttest_sgenf_csockt_large_tcp4/1,
+         ttest_sgenf_csockt_large_tcp6/1,
+
+         %% Server: transport = gen_tcp, active = once
+         %% Client: transport = gen_tcp
+         ttest_sgeno_cgenf_small_tcp4/1,
+         ttest_sgeno_cgenf_small_tcp6/1,
+         ttest_sgeno_cgenf_medium_tcp4/1,
+         ttest_sgeno_cgenf_medium_tcp6/1,
+         ttest_sgeno_cgenf_large_tcp4/1,
+         ttest_sgeno_cgenf_large_tcp6/1,
+
+         ttest_sgeno_cgeno_small_tcp4/1,
+         ttest_sgeno_cgeno_small_tcp6/1,
+         ttest_sgeno_cgeno_medium_tcp4/1,
+         ttest_sgeno_cgeno_medium_tcp6/1,
+         ttest_sgeno_cgeno_large_tcp4/1,
+         ttest_sgeno_cgeno_large_tcp6/1,
+
+         ttest_sgeno_cgent_small_tcp4/1,
+         ttest_sgeno_cgent_small_tcp6/1,
+         ttest_sgeno_cgent_medium_tcp4/1,
+         ttest_sgeno_cgent_medium_tcp6/1,
+         ttest_sgeno_cgent_large_tcp4/1,
+         ttest_sgeno_cgent_large_tcp6/1,
+
+         %% Server: transport = gen_tcp, active = once
+         %% Client: transport = socket(tcp)
+         ttest_sgeno_csockf_small_tcp4/1,
+         ttest_sgeno_csockf_small_tcp6/1,
+         ttest_sgeno_csockf_medium_tcp4/1,
+         ttest_sgeno_csockf_medium_tcp6/1,
+         ttest_sgeno_csockf_large_tcp4/1,
+         ttest_sgeno_csockf_large_tcp6/1,
+
+         ttest_sgeno_csocko_small_tcp4/1,
+         ttest_sgeno_csocko_small_tcp6/1,
+         ttest_sgeno_csocko_medium_tcp4/1,
+         ttest_sgeno_csocko_medium_tcp6/1,
+         ttest_sgeno_csocko_large_tcp4/1,
+         ttest_sgeno_csocko_large_tcp6/1,
+
+         ttest_sgeno_csockt_small_tcp4/1,
+         ttest_sgeno_csockt_small_tcp6/1,
+         ttest_sgeno_csockt_medium_tcp4/1,
+         ttest_sgeno_csockt_medium_tcp6/1,
+         ttest_sgeno_csockt_large_tcp4/1,
+         ttest_sgeno_csockt_large_tcp6/1,
+
+         %% Server: transport = gen_tcp, active = true
+         %% Client: transport = gen_tcp
+         ttest_sgent_cgenf_small_tcp4/1,
+         ttest_sgent_cgenf_small_tcp6/1,
+         ttest_sgent_cgenf_medium_tcp4/1,
+         ttest_sgent_cgenf_medium_tcp6/1,
+         ttest_sgent_cgenf_large_tcp4/1,
+         ttest_sgent_cgenf_large_tcp6/1,
+
+         ttest_sgent_cgeno_small_tcp4/1,
+         ttest_sgent_cgeno_small_tcp6/1,
+         ttest_sgent_cgeno_medium_tcp4/1,
+         ttest_sgent_cgeno_medium_tcp6/1,
+         ttest_sgent_cgeno_large_tcp4/1,
+         ttest_sgent_cgeno_large_tcp6/1,
+
+         ttest_sgent_cgent_small_tcp4/1,
+         ttest_sgent_cgent_small_tcp6/1,
+         ttest_sgent_cgent_medium_tcp4/1,
+         ttest_sgent_cgent_medium_tcp6/1,
+         ttest_sgent_cgent_large_tcp4/1,
+         ttest_sgent_cgent_large_tcp6/1,
+
+         %% Server: transport = gen_tcp, active = true
+         %% Client: transport = socket(tcp)
+         ttest_sgent_csockf_small_tcp4/1,
+         ttest_sgent_csockf_small_tcp6/1,
+         ttest_sgent_csockf_medium_tcp4/1,
+         ttest_sgent_csockf_medium_tcp6/1,
+         ttest_sgent_csockf_large_tcp4/1,
+         ttest_sgent_csockf_large_tcp6/1,
+
+         ttest_sgent_csocko_small_tcp4/1,
+         ttest_sgent_csocko_small_tcp6/1,
+         ttest_sgent_csocko_medium_tcp4/1,
+         ttest_sgent_csocko_medium_tcp6/1,
+         ttest_sgent_csocko_large_tcp4/1,
+         ttest_sgent_csocko_large_tcp6/1,
+
+         ttest_sgent_csockt_small_tcp4/1,
+         ttest_sgent_csockt_small_tcp6/1,
+         ttest_sgent_csockt_medium_tcp4/1,
+         ttest_sgent_csockt_medium_tcp6/1,
+         ttest_sgent_csockt_large_tcp4/1,
+         ttest_sgent_csockt_large_tcp6/1,
+
+         %% Server: transport = socket(tcp), active = false
+         %% Client: transport = gen_tcp
+         ttest_ssockf_cgenf_small_tcp4/1,
+         ttest_ssockf_cgenf_small_tcp6/1,
+         ttest_ssockf_cgenf_medium_tcp4/1,
+         ttest_ssockf_cgenf_medium_tcp6/1,
+         ttest_ssockf_cgenf_large_tcp4/1,
+         ttest_ssockf_cgenf_large_tcp6/1,
+
+         ttest_ssockf_cgeno_small_tcp4/1,
+         ttest_ssockf_cgeno_small_tcp6/1,
+         ttest_ssockf_cgeno_medium_tcp4/1,
+         ttest_ssockf_cgeno_medium_tcp6/1,
+         ttest_ssockf_cgeno_large_tcp4/1,
+         ttest_ssockf_cgeno_large_tcp6/1,
+
+         ttest_ssockf_cgent_small_tcp4/1,
+         ttest_ssockf_cgent_small_tcp6/1,
+         ttest_ssockf_cgent_medium_tcp4/1,
+         ttest_ssockf_cgent_medium_tcp6/1,
+         ttest_ssockf_cgent_large_tcp4/1,
+         ttest_ssockf_cgent_large_tcp6/1,
+
+         %% Server: transport = socket(tcp), active = false
+         %% Client: transport = socket(tcp)
+         ttest_ssockf_csockf_small_tcp4/1,
+         ttest_ssockf_csockf_small_tcp6/1,
+         ttest_ssockf_csockf_small_tcpL/1,
+         ttest_ssockf_csockf_medium_tcp4/1,
+         ttest_ssockf_csockf_medium_tcp6/1,
+         ttest_ssockf_csockf_medium_tcpL/1,
+         ttest_ssockf_csockf_large_tcp4/1,
+         ttest_ssockf_csockf_large_tcp6/1,
+         ttest_ssockf_csockf_large_tcpL/1,
+
+         ttest_ssockf_csocko_small_tcp4/1,
+         ttest_ssockf_csocko_small_tcp6/1,
+         ttest_ssockf_csocko_small_tcpL/1,
+         ttest_ssockf_csocko_medium_tcp4/1,
+         ttest_ssockf_csocko_medium_tcp6/1,
+         ttest_ssockf_csocko_medium_tcpL/1,
+         ttest_ssockf_csocko_large_tcp4/1,
+         ttest_ssockf_csocko_large_tcp6/1,
+         ttest_ssockf_csocko_large_tcpL/1,
+
+         ttest_ssockf_csockt_small_tcp4/1,
+         ttest_ssockf_csockt_small_tcp6/1,
+         ttest_ssockf_csockt_small_tcpL/1,
+         ttest_ssockf_csockt_medium_tcp4/1,
+         ttest_ssockf_csockt_medium_tcp6/1,
+         ttest_ssockf_csockt_medium_tcpL/1,
+         ttest_ssockf_csockt_large_tcp4/1,
+         ttest_ssockf_csockt_large_tcp6/1,
+         ttest_ssockf_csockt_large_tcpL/1,
+
+         %% Server: transport = socket(tcp), active = once
+         %% Client: transport = gen_tcp
+         ttest_ssocko_cgenf_small_tcp4/1,
+         ttest_ssocko_cgenf_small_tcp6/1,
+         ttest_ssocko_cgenf_medium_tcp4/1,
+         ttest_ssocko_cgenf_medium_tcp6/1,
+         ttest_ssocko_cgenf_large_tcp4/1,
+         ttest_ssocko_cgenf_large_tcp6/1,
+
+         ttest_ssocko_cgeno_small_tcp4/1,
+         ttest_ssocko_cgeno_small_tcp6/1,
+         ttest_ssocko_cgeno_medium_tcp4/1,
+         ttest_ssocko_cgeno_medium_tcp6/1,
+         ttest_ssocko_cgeno_large_tcp4/1,
+         ttest_ssocko_cgeno_large_tcp6/1,
+
+         ttest_ssocko_cgent_small_tcp4/1,
+         ttest_ssocko_cgent_small_tcp6/1,
+         ttest_ssocko_cgent_medium_tcp4/1,
+         ttest_ssocko_cgent_medium_tcp6/1,
+         ttest_ssocko_cgent_large_tcp4/1,
+         ttest_ssocko_cgent_large_tcp6/1,
+
+         %% Server: transport = socket(tcp), active = once
+         %% Client: transport = socket(tcp)
+         ttest_ssocko_csockf_small_tcp4/1,
+         ttest_ssocko_csockf_small_tcp6/1,
+         ttest_ssocko_csockf_small_tcpL/1,
+         ttest_ssocko_csockf_medium_tcp4/1,
+         ttest_ssocko_csockf_medium_tcpL/1,
+         ttest_ssocko_csockf_medium_tcp6/1,
+         ttest_ssocko_csockf_large_tcp4/1,
+         ttest_ssocko_csockf_large_tcp6/1,
+         ttest_ssocko_csockf_large_tcpL/1,
+
+         ttest_ssocko_csocko_small_tcp4/1,
+         ttest_ssocko_csocko_small_tcp6/1,
+         ttest_ssocko_csocko_small_tcpL/1,
+         ttest_ssocko_csocko_medium_tcp4/1,
+         ttest_ssocko_csocko_medium_tcp6/1,
+         ttest_ssocko_csocko_medium_tcpL/1,
+         ttest_ssocko_csocko_large_tcp4/1,
+         ttest_ssocko_csocko_large_tcp6/1,
+         ttest_ssocko_csocko_large_tcpL/1,
+
+         ttest_ssocko_csockt_small_tcp4/1,
+         ttest_ssocko_csockt_small_tcp6/1,
+         ttest_ssocko_csockt_small_tcpL/1,
+         ttest_ssocko_csockt_medium_tcp4/1,
+         ttest_ssocko_csockt_medium_tcp6/1,
+         ttest_ssocko_csockt_medium_tcpL/1,
+         ttest_ssocko_csockt_large_tcp4/1,
+         ttest_ssocko_csockt_large_tcp6/1,
+         ttest_ssocko_csockt_large_tcpL/1,
+
+         %% Server: transport = socket(tcp), active = true
+         %% Client: transport = gen_tcp
+         ttest_ssockt_cgenf_small_tcp4/1,
+         ttest_ssockt_cgenf_small_tcp6/1,
+         ttest_ssockt_cgenf_medium_tcp4/1,
+         ttest_ssockt_cgenf_medium_tcp6/1,
+         ttest_ssockt_cgenf_large_tcp4/1,
+         ttest_ssockt_cgenf_large_tcp6/1,
+
+         ttest_ssockt_cgeno_small_tcp4/1,
+         ttest_ssockt_cgeno_small_tcp6/1,
+         ttest_ssockt_cgeno_medium_tcp4/1,
+         ttest_ssockt_cgeno_medium_tcp6/1,
+         ttest_ssockt_cgeno_large_tcp4/1,
+         ttest_ssockt_cgeno_large_tcp6/1,
+
+         ttest_ssockt_cgent_small_tcp4/1,
+         ttest_ssockt_cgent_small_tcp6/1,
+         ttest_ssockt_cgent_medium_tcp4/1,
+         ttest_ssockt_cgent_medium_tcp6/1,
+         ttest_ssockt_cgent_large_tcp4/1,
+         ttest_ssockt_cgent_large_tcp6/1,
+
+         %% Server: transport = socket(tcp), active = true
+         %% Client: transport = socket(tcp)
+         ttest_ssockt_csockf_small_tcp4/1,
+         ttest_ssockt_csockf_small_tcp6/1,
+         ttest_ssockt_csockf_small_tcpL/1,
+         ttest_ssockt_csockf_medium_tcp4/1,
+         ttest_ssockt_csockf_medium_tcp6/1,
+         ttest_ssockt_csockf_medium_tcpL/1,
+         ttest_ssockt_csockf_large_tcp4/1,
+         ttest_ssockt_csockf_large_tcp6/1,
+         ttest_ssockt_csockf_large_tcpL/1,
+
+         ttest_ssockt_csocko_small_tcp4/1,
+         ttest_ssockt_csocko_small_tcp6/1,
+         ttest_ssockt_csocko_small_tcpL/1,
+         ttest_ssockt_csocko_medium_tcp4/1,
+         ttest_ssockt_csocko_medium_tcp6/1,
+         ttest_ssockt_csocko_medium_tcpL/1,
+         ttest_ssockt_csocko_large_tcp4/1,
+         ttest_ssockt_csocko_large_tcp6/1,
+         ttest_ssockt_csocko_large_tcpL/1,
+
+         ttest_ssockt_csockt_small_tcp4/1,
+         ttest_ssockt_csockt_small_tcp6/1,
+         ttest_ssockt_csockt_small_tcpL/1,
+         ttest_ssockt_csockt_medium_tcp4/1,
+         ttest_ssockt_csockt_medium_tcp6/1,
+         ttest_ssockt_csockt_medium_tcpL/1,
+         ttest_ssockt_csockt_large_tcp4/1,
+         ttest_ssockt_csockt_large_tcp6/1,
+         ttest_ssockt_csockt_large_tcpL/1
+
+         %% Tickets
+        ]).
+
+
+%% Internal exports
+%% -export([]).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+-define(LIB,        socket_test_lib).
+-define(TTEST_LIB,  socket_test_ttest_lib).
+-define(LOGGER,     socket_test_logger).
+
+-define(BASIC_REQ,  <<"hejsan">>).
+-define(BASIC_REP,  <<"hoppsan">>).
+
+-define(DATA,       <<"HOPPSAN">>). % Temporary
+-define(FAIL(R),    exit(R)).
+
+-define(SLEEP(T),   receive after T -> ok end).
+
+-define(MINS(M),    timer:minutes(M)).
+-define(SECS(S),    timer:seconds(S)).
+
+-define(TT(T),      ct:timetrap(T)).
+
+-define(F(F, A),    ?LIB:f(F, A)).
+
+
+-define(TPP_SMALL,  lists:seq(1, 8)).
+-define(TPP_MEDIUM, lists:flatten(lists:duplicate(1024, ?TPP_SMALL))).
+-define(TPP_LARGE,  lists:flatten(lists:duplicate(1024, ?TPP_MEDIUM))).
+
+-define(TPP_SMALL_NUM,  10000).
+-define(TPP_MEDIUM_NUM, 1000).
+-define(TPP_LARGE_NUM,  100).
+
+-define(TTEST_RUNTIME,  ?SECS(10)).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+suite() ->
+    [{ct_hooks,[ts_install_cth]},
+     {timetrap,{minutes,1}}].
+
+all() -> 
+    Groups = [{api,          "ESOCK_TEST_API",        include},
+	      {socket_close, "ESOCK_TEST_SOCK_CLOSE", include},
+	      {traffic,      "ESOCK_TEST_TRAFFIC",    include},
+	      {ttest,        "ESOCK_TEST_TTEST",      exclude}],
+    [use_group(Group, Env, Default) || {Group, Env, Default} <- Groups].
+
+use_group(Group, Env, Default) ->
+	case os:getenv(Env) of
+	    false when (Default =:= include) ->
+		[{group, Group}];
+	    false ->
+		[];
+	    Val ->
+		case list_to_atom(string:to_lower(Val)) of
+		    Use when (Use =:= include) orelse 
+			     (Use =:= enable) orelse 
+			     (Use =:= true) ->
+			[{group, Group}];
+		    _ ->
+			[]
+		end
+	end.
+    
+
+groups() -> 
+    [{api,                         [], api_cases()},
+     {api_misc,                    [], api_misc_cases()},
+     {api_basic,                   [], api_basic_cases()},
+     {api_async,                   [], api_async_cases()},
+     {api_options,                 [], api_options_cases()},
+     {api_options_otp,             [], api_options_otp_cases()},
+     {api_options_socket,          [], api_options_socket_cases()},
+     {api_option_sock_acceptconn,  [], api_option_sock_acceptconn_cases()},
+     {api_options_ip,              [], api_options_ip_cases()},
+     %% {api_options_ipv6,           [], api_options_ipv6_cases()},
+     %% {api_options_tcp,            [], api_options_tcp_cases()},
+     %% {api_options_udp,            [], api_options_udp_cases()},
+     %% {api_options_sctp,           [], api_options_sctp_cases()},
+     {api_op_with_timeout,         [], api_op_with_timeout_cases()},
+     {socket_close,                [], socket_close_cases()},
+     {sc_ctrl_proc_exit,           [], sc_cp_exit_cases()},
+     {sc_local_close,              [], sc_lc_cases()},
+     {sc_remote_close,             [], sc_rc_cases()},
+     {sc_remote_shutdown,          [], sc_rs_cases()},
+     {traffic,                     [], traffic_cases()},
+     {traffic_counters,            [], traffic_counters_cases()},
+     {traffic_chunks,              [], traffic_chunks_cases()},
+     {traffic_pp_send_recv,        [], traffic_pp_send_recv_cases()},
+     {traffic_pp_sendto_recvfrom,  [], traffic_pp_sendto_recvfrom_cases()},
+     {traffic_pp_sendmsg_recvmsg,  [], traffic_pp_sendmsg_recvmsg_cases()},
+     {ttest,                       [], ttest_cases()},
+     {ttest_sgenf,                 [], ttest_sgenf_cases()},
+     {ttest_sgenf_cgen,            [], ttest_sgenf_cgen_cases()},
+     {ttest_sgenf_cgenf,           [], ttest_sgenf_cgenf_cases()},
+     {ttest_sgenf_cgeno,           [], ttest_sgenf_cgeno_cases()},
+     {ttest_sgenf_cgent,           [], ttest_sgenf_cgent_cases()},
+     {ttest_sgenf_csock,           [], ttest_sgenf_csock_cases()},
+     {ttest_sgenf_csockf,          [], ttest_sgenf_csockf_cases()},
+     {ttest_sgenf_csocko,          [], ttest_sgenf_csocko_cases()},
+     {ttest_sgenf_csockt,          [], ttest_sgenf_csockt_cases()},
+     {ttest_sgeno,                 [], ttest_sgeno_cases()},
+     {ttest_sgeno_cgen,            [], ttest_sgeno_cgen_cases()},
+     {ttest_sgeno_cgenf,           [], ttest_sgeno_cgenf_cases()},
+     {ttest_sgeno_cgeno,           [], ttest_sgeno_cgeno_cases()},
+     {ttest_sgeno_cgent,           [], ttest_sgeno_cgent_cases()},
+     {ttest_sgeno_csock,           [], ttest_sgeno_csock_cases()},
+     {ttest_sgeno_csockf,          [], ttest_sgeno_csockf_cases()},
+     {ttest_sgeno_csocko,          [], ttest_sgeno_csocko_cases()},
+     {ttest_sgeno_csockt,          [], ttest_sgeno_csockt_cases()},
+     {ttest_sgent,                 [], ttest_sgent_cases()},
+     {ttest_sgent_cgen,            [], ttest_sgent_cgen_cases()},
+     {ttest_sgent_cgenf,           [], ttest_sgent_cgenf_cases()},
+     {ttest_sgent_cgeno,           [], ttest_sgent_cgeno_cases()},
+     {ttest_sgent_cgent,           [], ttest_sgent_cgent_cases()},
+     {ttest_sgent_csock,           [], ttest_sgent_csock_cases()},
+     {ttest_sgent_csockf,          [], ttest_sgent_csockf_cases()},
+     {ttest_sgent_csocko,          [], ttest_sgent_csocko_cases()},
+     {ttest_sgent_csockt,          [], ttest_sgent_csockt_cases()},
+     {ttest_ssockf,                [], ttest_ssockf_cases()},
+     {ttest_ssockf_cgen,           [], ttest_ssockf_cgen_cases()},
+     {ttest_ssockf_cgenf,          [], ttest_ssockf_cgenf_cases()},
+     {ttest_ssockf_cgeno,          [], ttest_ssockf_cgeno_cases()},
+     {ttest_ssockf_cgent,          [], ttest_ssockf_cgent_cases()},
+     {ttest_ssockf_csock,          [], ttest_ssockf_csock_cases()},
+     {ttest_ssockf_csockf,         [], ttest_ssockf_csockf_cases()},
+     {ttest_ssockf_csocko,         [], ttest_ssockf_csocko_cases()},
+     {ttest_ssockf_csockt,         [], ttest_ssockf_csockt_cases()},
+     {ttest_ssocko,                [], ttest_ssocko_cases()},
+     {ttest_ssocko_cgen,           [], ttest_ssocko_cgen_cases()},
+     {ttest_ssocko_cgenf,          [], ttest_ssocko_cgenf_cases()},
+     {ttest_ssocko_cgeno,          [], ttest_ssocko_cgeno_cases()},
+     {ttest_ssocko_cgent,          [], ttest_ssocko_cgent_cases()},
+     {ttest_ssocko_csock,          [], ttest_ssocko_csock_cases()},
+     {ttest_ssocko_csockf,         [], ttest_ssocko_csockf_cases()},
+     {ttest_ssocko_csocko,         [], ttest_ssocko_csocko_cases()},
+     {ttest_ssocko_csockt,         [], ttest_ssocko_csockt_cases()},
+     {ttest_ssockt,                [], ttest_ssockt_cases()},
+     {ttest_ssockt_cgen,           [], ttest_ssockt_cgen_cases()},
+     {ttest_ssockt_cgenf,          [], ttest_ssockt_cgenf_cases()},
+     {ttest_ssockt_cgeno,          [], ttest_ssockt_cgeno_cases()},
+     {ttest_ssockt_cgent,          [], ttest_ssockt_cgent_cases()},
+     {ttest_ssockt_csock,          [], ttest_ssockt_csock_cases()},
+     {ttest_ssockt_csockf,         [], ttest_ssockt_csockf_cases()},
+     {ttest_ssockt_csocko,         [], ttest_ssockt_csocko_cases()},
+     {ttest_ssockt_csockt,         [], ttest_ssockt_csockt_cases()}
+
+     %% {tickets,             [], ticket_cases()}
+    ].
+     
+api_cases() ->
+    [
+     {group, api_misc},
+     {group, api_basic},
+     {group, api_async},
+     {group, api_options},
+     {group, api_op_with_timeout}
+    ].
+
+api_misc_cases() ->
+    [
+     api_m_debug
+    ].
+
+api_basic_cases() ->
+    [
+     api_b_open_and_close_udp4,
+     api_b_open_and_close_tcp4,
+     api_b_open_and_close_udpL,
+     api_b_open_and_close_tcpL,
+     api_b_sendto_and_recvfrom_udp4,
+     api_b_sendto_and_recvfrom_udpL,
+     api_b_sendmsg_and_recvmsg_udp4,
+     api_b_sendmsg_and_recvmsg_udpL,
+     api_b_send_and_recv_tcp4,
+     api_b_send_and_recv_tcpL,
+     api_b_sendmsg_and_recvmsg_tcp4,
+     api_b_sendmsg_and_recvmsg_tcpL
+    ].
+
+api_async_cases() ->
+    [
+     api_a_connect_tcp4,
+     api_a_connect_tcp6,
+     api_a_sendto_and_recvfrom_udp4,
+     api_a_sendto_and_recvfrom_udp6,
+     api_a_sendmsg_and_recvmsg_udp4,
+     api_a_sendmsg_and_recvmsg_udp6,
+     api_a_send_and_recv_tcp4,
+     api_a_send_and_recv_tcp6,
+     api_a_sendmsg_and_recvmsg_tcp4,
+     api_a_sendmsg_and_recvmsg_tcp6,
+     api_a_recvfrom_cancel_udp4,
+     api_a_recvfrom_cancel_udp6,
+     api_a_recvmsg_cancel_udp4,
+     api_a_recvmsg_cancel_udp6,
+     api_a_accept_cancel_tcp4,
+     api_a_accept_cancel_tcp6,
+     api_a_recv_cancel_tcp4,
+     api_a_recv_cancel_tcp6,
+     api_a_recvmsg_cancel_tcp4,
+     api_a_recvmsg_cancel_tcp6,
+     api_a_mrecvfrom_cancel_udp4,
+     api_a_mrecvfrom_cancel_udp6,
+     api_a_mrecvmsg_cancel_udp4,
+     api_a_mrecvmsg_cancel_udp6,
+     api_a_maccept_cancel_tcp4,
+     api_a_maccept_cancel_tcp6,
+     api_a_mrecv_cancel_tcp4,
+     api_a_mrecv_cancel_tcp6,
+     api_a_mrecvmsg_cancel_tcp4,
+     api_a_mrecvmsg_cancel_tcp6
+    ].
+
+api_options_cases() ->
+    [
+     {group, api_options_otp},
+     {group, api_options_socket},
+     {group, api_options_ip}% ,
+     %% {group, api_options_ipv6},
+     %% {group, api_options_tcp},
+     %% {group, api_options_udp},
+     %% {group, api_options_sctp}
+    ].
+
+api_options_otp_cases() ->
+    [
+     api_opt_simple_otp_options,
+     api_opt_simple_otp_rcvbuf_option,
+     api_opt_simple_otp_controlling_process
+    ].
+
+api_options_socket_cases() ->
+    [
+     {group, api_option_sock_acceptconn},
+     api_opt_sock_acceptfilter,
+     api_opt_sock_bindtodevice,
+     api_opt_sock_broadcast,
+     api_opt_sock_debug,
+     api_opt_sock_domain,
+     api_opt_sock_dontroute,
+     api_opt_sock_error,
+     api_opt_sock_keepalive,
+     api_opt_sock_linger
+    ].
+
+api_option_sock_acceptconn_cases() ->
+    [
+     api_opt_sock_acceptconn_udp,
+     api_opt_sock_acceptconn_tcp
+    ].
+
+api_options_ip_cases() ->
+    [
+     api_opt_ip_add_drop_membership
+    ].
+
+%% api_options_ipv6_cases() ->
+%%     [
+%%     ].
+
+api_op_with_timeout_cases() ->
+    [
+     api_to_connect_tcp4,
+     api_to_connect_tcp6,
+     api_to_accept_tcp4,
+     api_to_accept_tcp6,
+     api_to_maccept_tcp4,
+     api_to_maccept_tcp6,
+     api_to_send_tcp4,
+     api_to_send_tcp6,
+     api_to_sendto_udp4,
+     api_to_sendto_udp6,
+     api_to_sendmsg_tcp4,
+     api_to_sendmsg_tcp6,
+     api_to_recv_udp4,
+     api_to_recv_udp6,
+     api_to_recv_tcp4,
+     api_to_recv_tcp6,
+     api_to_recvfrom_udp4,
+     api_to_recvfrom_udp6,
+     api_to_recvmsg_udp4,
+     api_to_recvmsg_udp6,
+     api_to_recvmsg_tcp4,
+     api_to_recvmsg_tcp6
+    ].
+
+%% These cases tests what happens when the socket is closed/shutdown,
+%% locally or remotely.
+socket_close_cases() ->
+    [
+     {group, sc_ctrl_proc_exit},
+     {group, sc_local_close},
+     {group, sc_remote_close},
+     {group, sc_remote_shutdown}
+    ].
+
+%% These cases are all about socket cleanup after the controlling process
+%% exits *without* explicitly calling socket:close/1.
+sc_cp_exit_cases() ->
+    [
+     sc_cpe_socket_cleanup_tcp4,
+     sc_cpe_socket_cleanup_tcp6,
+     sc_cpe_socket_cleanup_tcpL,
+     sc_cpe_socket_cleanup_udp4,
+     sc_cpe_socket_cleanup_udp6,
+     sc_cpe_socket_cleanup_udpL
+    ].
+
+%% These cases tests what happens when the socket is closed locally.
+sc_lc_cases() ->
+    [
+     sc_lc_recv_response_tcp4,
+     sc_lc_recv_response_tcp6,
+     sc_lc_recv_response_tcpL,
+
+     sc_lc_recvfrom_response_udp4,
+     sc_lc_recvfrom_response_udp6,
+     sc_lc_recvfrom_response_udpL,
+
+     sc_lc_recvmsg_response_tcp4,
+     sc_lc_recvmsg_response_tcp6,
+     sc_lc_recvmsg_response_tcpL,
+     sc_lc_recvmsg_response_udp4,
+     sc_lc_recvmsg_response_udp6,
+     sc_lc_recvmsg_response_udpL,
+
+     sc_lc_acceptor_response_tcp4,
+     sc_lc_acceptor_response_tcp6,
+     sc_lc_acceptor_response_tcpL
+    ].
+
+%% These cases tests what happens when the socket is closed remotely.
+sc_rc_cases() ->
+    [
+     sc_rc_recv_response_tcp4,
+     sc_rc_recv_response_tcp6,
+     sc_rc_recv_response_tcpL,
+
+     sc_rc_recvmsg_response_tcp4,
+     sc_rc_recvmsg_response_tcp6,
+     sc_rc_recvmsg_response_tcpL
+    ].
+
+%% These cases tests what happens when the socket is shutdown/closed remotely
+%% after writing and reading is ongoing.
+sc_rs_cases() ->
+    [
+     sc_rs_recv_send_shutdown_receive_tcp4,
+     sc_rs_recv_send_shutdown_receive_tcp6,
+     sc_rs_recv_send_shutdown_receive_tcpL,
+
+     sc_rs_recvmsg_send_shutdown_receive_tcp4,
+     sc_rs_recvmsg_send_shutdown_receive_tcp6,
+     sc_rs_recvmsg_send_shutdown_receive_tcpL
+    ].
+
+
+traffic_cases() ->
+    [
+     {group, traffic_counters},
+     {group, traffic_chunks},
+     {group, traffic_pp_send_recv},
+     {group, traffic_pp_sendto_recvfrom},
+     {group, traffic_pp_sendmsg_recvmsg}
+    ].
+
+traffic_counters_cases() ->
+    [
+     traffic_send_and_recv_counters_tcp4,
+     traffic_send_and_recv_counters_tcp6,
+     traffic_send_and_recv_counters_tcpL,
+     traffic_sendmsg_and_recvmsg_counters_tcp4,
+     traffic_sendmsg_and_recvmsg_counters_tcp6,
+     traffic_sendmsg_and_recvmsg_counters_tcpL,
+     traffic_sendto_and_recvfrom_counters_udp4,
+     traffic_sendto_and_recvfrom_counters_udp6,
+     traffic_sendto_and_recvfrom_counters_udpL,
+     traffic_sendmsg_and_recvmsg_counters_udp4,
+     traffic_sendmsg_and_recvmsg_counters_udp6,
+     traffic_sendmsg_and_recvmsg_counters_udpL
+    ].
+
+traffic_chunks_cases() ->
+    [
+     traffic_send_and_recv_chunks_tcp4,
+     traffic_send_and_recv_chunks_tcp6,
+     traffic_send_and_recv_chunks_tcpL
+    ].
+
+traffic_pp_send_recv_cases() ->
+    [
+     traffic_ping_pong_small_send_and_recv_tcp4,
+     traffic_ping_pong_small_send_and_recv_tcp6,
+     traffic_ping_pong_small_send_and_recv_tcpL,
+     traffic_ping_pong_medium_send_and_recv_tcp4,
+     traffic_ping_pong_medium_send_and_recv_tcp6,
+     traffic_ping_pong_medium_send_and_recv_tcpL,
+     traffic_ping_pong_large_send_and_recv_tcp4,
+     traffic_ping_pong_large_send_and_recv_tcp6,
+     traffic_ping_pong_large_send_and_recv_tcpL
+    ].    
+
+traffic_pp_sendto_recvfrom_cases() ->
+    [
+     traffic_ping_pong_small_sendto_and_recvfrom_udp4,
+     traffic_ping_pong_small_sendto_and_recvfrom_udp6,
+     traffic_ping_pong_small_sendto_and_recvfrom_udpL,
+     traffic_ping_pong_medium_sendto_and_recvfrom_udp4,
+     traffic_ping_pong_medium_sendto_and_recvfrom_udp6,
+     traffic_ping_pong_medium_sendto_and_recvfrom_udpL
+    ].
+
+traffic_pp_sendmsg_recvmsg_cases() ->
+    [    
+     traffic_ping_pong_small_sendmsg_and_recvmsg_tcp4,
+     traffic_ping_pong_small_sendmsg_and_recvmsg_tcp6,
+     traffic_ping_pong_small_sendmsg_and_recvmsg_tcpL,
+     traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp4,
+     traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp6,
+     traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL,
+     traffic_ping_pong_large_sendmsg_and_recvmsg_tcp4,
+     traffic_ping_pong_large_sendmsg_and_recvmsg_tcp6,
+     traffic_ping_pong_large_sendmsg_and_recvmsg_tcpL,
+
+     traffic_ping_pong_small_sendmsg_and_recvmsg_udp4,
+     traffic_ping_pong_small_sendmsg_and_recvmsg_udp6,
+     traffic_ping_pong_small_sendmsg_and_recvmsg_udpL,
+     traffic_ping_pong_medium_sendmsg_and_recvmsg_udp4,
+     traffic_ping_pong_medium_sendmsg_and_recvmsg_udp6,
+     traffic_ping_pong_medium_sendmsg_and_recvmsg_udpL
+    ].
+    
+ttest_cases() ->
+    [
+     %% Server: transport = gen_tcp, active = false
+     {group, ttest_sgenf},
+
+     %% Server: transport = gen_tcp, active = once
+     {group, ttest_sgeno},
+
+     %% Server: transport = gen_tcp, active = true
+     {group, ttest_sgent},
+
+     %% Server: transport = socket(tcp), active = false
+     {group, ttest_ssockf},
+
+     %% Server: transport = socket(tcp), active = once
+     {group, ttest_ssocko},
+
+     %% Server: transport = socket(tcp), active = true
+     {group, ttest_ssockt}
+
+    ].
+
+
+%% Server: transport = gen_tcp, active = false
+ttest_sgenf_cases() ->
+    [
+     {group, ttest_sgenf_cgen},
+     {group, ttest_sgenf_csock}
+    ].
+
+%% Server: transport = gen_tcp, active = false
+%% Client: transport = gen_tcp
+ttest_sgenf_cgen_cases() ->
+    [
+     {group, ttest_sgenf_cgenf},
+     {group, ttest_sgenf_cgeno},
+     {group, ttest_sgenf_cgent}
+    ].
+
+%% Server: transport = gen_tcp, active = false
+%% Client: transport = gen_tcp, active = false
+ttest_sgenf_cgenf_cases() ->
+    [
+     ttest_sgenf_cgenf_small_tcp4,
+     ttest_sgenf_cgenf_small_tcp6,
+
+     ttest_sgenf_cgenf_medium_tcp4,
+     ttest_sgenf_cgenf_medium_tcp6,
+
+     ttest_sgenf_cgenf_large_tcp4,
+     ttest_sgenf_cgenf_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = false
+%% Client: transport = gen_tcp, active = once
+ttest_sgenf_cgeno_cases() ->
+    [
+     ttest_sgenf_cgeno_small_tcp4,
+     ttest_sgenf_cgeno_small_tcp6,
+
+     ttest_sgenf_cgeno_medium_tcp4,
+     ttest_sgenf_cgeno_medium_tcp6,
+
+     ttest_sgenf_cgeno_large_tcp4,
+     ttest_sgenf_cgeno_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = false
+%% Client: transport = gen_tcp, active = true
+ttest_sgenf_cgent_cases() ->
+    [
+     ttest_sgenf_cgent_small_tcp4,
+     ttest_sgenf_cgent_small_tcp6,
+
+     ttest_sgenf_cgent_medium_tcp4,
+     ttest_sgenf_cgent_medium_tcp6,
+
+     ttest_sgenf_cgent_large_tcp4,
+     ttest_sgenf_cgent_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = false
+%% Client: transport = socket(tcp)
+ttest_sgenf_csock_cases() ->
+    [
+     {group, ttest_sgenf_csockf},
+     {group, ttest_sgenf_csocko},
+     {group, ttest_sgenf_csockt}
+    ].
+
+ttest_sgenf_csockf_cases() ->
+    [
+     ttest_sgenf_csockf_small_tcp4,
+     ttest_sgenf_csockf_small_tcp6,
+
+     ttest_sgenf_csockf_medium_tcp4,
+     ttest_sgenf_csockf_medium_tcp6,
+
+     ttest_sgenf_csockf_large_tcp4,
+     ttest_sgenf_csockf_large_tcp6
+    ].
+
+ttest_sgenf_csocko_cases() ->
+    [
+     ttest_sgenf_csocko_small_tcp4,
+     ttest_sgenf_csocko_small_tcp6,
+
+     ttest_sgenf_csocko_medium_tcp4,
+     ttest_sgenf_csocko_medium_tcp6,
+
+     ttest_sgenf_csocko_large_tcp4,
+     ttest_sgenf_csocko_large_tcp6
+    ].
+
+ttest_sgenf_csockt_cases() ->
+    [
+     ttest_sgenf_csockt_small_tcp4,
+     ttest_sgenf_csockt_small_tcp6,
+
+     ttest_sgenf_csockt_medium_tcp4,
+     ttest_sgenf_csockt_medium_tcp6,
+
+     ttest_sgenf_csockt_large_tcp4,
+     ttest_sgenf_csockt_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = once
+ttest_sgeno_cases() ->
+    [
+     {group, ttest_sgeno_cgen},
+     {group, ttest_sgeno_csock}
+    ].
+
+%% Server: transport = gen_tcp, active = once
+%% Client: transport = gen_tcp
+ttest_sgeno_cgen_cases() ->
+    [
+     {group, ttest_sgeno_cgenf},
+     {group, ttest_sgeno_cgeno},
+     {group, ttest_sgeno_cgent}
+    ].
+
+%% Server: transport = gen_tcp, active = once
+%% Client: transport = gen_tcp, active = false
+ttest_sgeno_cgenf_cases() ->
+    [
+     ttest_sgeno_cgenf_small_tcp4,
+     ttest_sgeno_cgenf_small_tcp6,
+
+     ttest_sgeno_cgenf_medium_tcp4,
+     ttest_sgeno_cgenf_medium_tcp6,
+
+     ttest_sgeno_cgenf_large_tcp4,
+     ttest_sgeno_cgenf_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = once
+%% Client: transport = gen_tcp, active = once
+ttest_sgeno_cgeno_cases() ->
+    [
+     ttest_sgeno_cgeno_small_tcp4,
+     ttest_sgeno_cgeno_small_tcp6,
+
+     ttest_sgeno_cgeno_medium_tcp4,
+     ttest_sgeno_cgeno_medium_tcp6,
+
+     ttest_sgeno_cgeno_large_tcp4,
+     ttest_sgeno_cgeno_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = once
+%% Client: transport = gen_tcp, active = true
+ttest_sgeno_cgent_cases() ->
+    [
+     ttest_sgeno_cgent_small_tcp4,
+     ttest_sgeno_cgent_small_tcp6,
+
+     ttest_sgeno_cgent_medium_tcp4,
+     ttest_sgeno_cgent_medium_tcp6,
+
+     ttest_sgeno_cgent_large_tcp4,
+     ttest_sgeno_cgent_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = once
+%% Client: transport = socket(tcp)
+ttest_sgeno_csock_cases() ->
+    [
+     {group, ttest_sgeno_csockf},
+     {group, ttest_sgeno_csocko},
+     {group, ttest_sgeno_csockt}
+    ].
+
+ttest_sgeno_csockf_cases() ->
+    [
+     ttest_sgeno_csockf_small_tcp4,
+     ttest_sgeno_csockf_small_tcp6,
+
+     ttest_sgeno_csockf_medium_tcp4,
+     ttest_sgeno_csockf_medium_tcp6,
+
+     ttest_sgeno_csockf_large_tcp4,
+     ttest_sgeno_csockf_large_tcp6
+    ].
+
+ttest_sgeno_csocko_cases() ->
+    [
+     ttest_sgeno_csocko_small_tcp4,
+     ttest_sgeno_csocko_small_tcp6,
+
+     ttest_sgeno_csocko_medium_tcp4,
+     ttest_sgeno_csocko_medium_tcp6,
+
+     ttest_sgeno_csocko_large_tcp4,
+     ttest_sgeno_csocko_large_tcp6
+    ].
+
+ttest_sgeno_csockt_cases() ->
+    [
+     ttest_sgeno_csockt_small_tcp4,
+     ttest_sgeno_csockt_small_tcp6,
+
+     ttest_sgeno_csockt_medium_tcp4,
+     ttest_sgeno_csockt_medium_tcp6,
+
+     ttest_sgeno_csockt_large_tcp4,
+     ttest_sgeno_csockt_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = true
+ttest_sgent_cases() ->
+    [
+     {group, ttest_sgent_cgen},
+     {group, ttest_sgent_csock}
+    ].
+
+%% Server: transport = gen_tcp, active = true
+%% Client: transport = gen_tcp
+ttest_sgent_cgen_cases() ->
+    [
+     {group, ttest_sgent_cgenf},
+     {group, ttest_sgent_cgeno},
+     {group, ttest_sgent_cgent}
+    ].
+
+%% Server: transport = gen_tcp, active = true
+%% Client: transport = gen_tcp, active = false
+ttest_sgent_cgenf_cases() ->
+    [
+     ttest_sgent_cgenf_small_tcp4,
+     ttest_sgent_cgenf_small_tcp6,
+
+     ttest_sgent_cgenf_medium_tcp4,
+     ttest_sgent_cgenf_medium_tcp6,
+
+     ttest_sgent_cgenf_large_tcp4,
+     ttest_sgent_cgenf_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = true
+%% Client: transport = gen_tcp, active = once
+ttest_sgent_cgeno_cases() ->
+    [
+     ttest_sgent_cgeno_small_tcp4,
+     ttest_sgent_cgeno_small_tcp6,
+
+     ttest_sgent_cgeno_medium_tcp4,
+     ttest_sgent_cgeno_medium_tcp6,
+
+     ttest_sgent_cgeno_large_tcp4,
+     ttest_sgent_cgeno_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = true
+%% Client: transport = gen_tcp, active = true
+ttest_sgent_cgent_cases() ->
+    [
+     ttest_sgent_cgent_small_tcp4,
+     ttest_sgent_cgent_small_tcp6,
+
+     ttest_sgent_cgent_medium_tcp4,
+     ttest_sgent_cgent_medium_tcp6,
+
+     ttest_sgent_cgent_large_tcp4,
+     ttest_sgent_cgent_large_tcp6
+    ].
+
+%% Server: transport = gen_tcp, active = true
+%% Client: transport = socket(tcp)
+ttest_sgent_csock_cases() ->
+    [
+     {group, ttest_sgent_csockf},
+     {group, ttest_sgent_csocko},
+     {group, ttest_sgent_csockt}
+    ].
+
+ttest_sgent_csockf_cases() ->
+    [
+     ttest_sgent_csockf_small_tcp4,
+     ttest_sgent_csockf_small_tcp6,
+
+     ttest_sgent_csockf_medium_tcp4,
+     ttest_sgent_csockf_medium_tcp6,
+
+     ttest_sgent_csockf_large_tcp4,
+     ttest_sgent_csockf_large_tcp6
+    ].
+
+ttest_sgent_csocko_cases() ->
+    [
+     ttest_sgent_csocko_small_tcp4,
+     ttest_sgent_csocko_small_tcp6,
+
+     ttest_sgent_csocko_medium_tcp4,
+     ttest_sgent_csocko_medium_tcp6,
+
+     ttest_sgent_csocko_large_tcp4,
+     ttest_sgent_csocko_large_tcp6
+    ].
+
+ttest_sgent_csockt_cases() ->
+    [
+     ttest_sgent_csockt_small_tcp4,
+     ttest_sgent_csockt_small_tcp6,
+
+     ttest_sgent_csockt_medium_tcp4,
+     ttest_sgent_csockt_medium_tcp6,
+
+     ttest_sgent_csockt_large_tcp4,
+     ttest_sgent_csockt_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = false
+ttest_ssockf_cases() ->
+    [
+     {group, ttest_ssockf_cgen},
+     {group, ttest_ssockf_csock}
+    ].
+
+%% Server: transport = socket(tcp), active = false
+%% Client: transport = gen_tcp
+ttest_ssockf_cgen_cases() ->
+    [
+     {group, ttest_ssockf_cgenf},
+     {group, ttest_ssockf_cgeno},
+     {group, ttest_ssockf_cgent}
+    ].
+
+%% Server: transport = socket(tcp), active = false
+%% Client: transport = gen_tcp, active = false
+ttest_ssockf_cgenf_cases() ->
+    [
+     ttest_ssockf_cgenf_small_tcp4,
+     ttest_ssockf_cgenf_small_tcp6,
+
+     ttest_ssockf_cgenf_medium_tcp4,
+     ttest_ssockf_cgenf_medium_tcp6,
+
+     ttest_ssockf_cgenf_large_tcp4,
+     ttest_ssockf_cgenf_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = false
+%% Client: transport = gen_tcp, active = once
+ttest_ssockf_cgeno_cases() ->
+    [
+     ttest_ssockf_cgeno_small_tcp4,
+     ttest_ssockf_cgeno_small_tcp6,
+
+     ttest_ssockf_cgeno_medium_tcp4,
+     ttest_ssockf_cgeno_medium_tcp6,
+
+     ttest_ssockf_cgeno_large_tcp4,
+     ttest_ssockf_cgeno_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = false
+%% Client: transport = gen_tcp, active = true
+ttest_ssockf_cgent_cases() ->
+    [
+     ttest_ssockf_cgent_small_tcp4,
+     ttest_ssockf_cgent_small_tcp6,
+
+     ttest_ssockf_cgent_medium_tcp4,
+     ttest_ssockf_cgent_medium_tcp6,
+
+     ttest_ssockf_cgent_large_tcp4,
+     ttest_ssockf_cgent_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = false
+%% Client: transport = socket(tcp)
+ttest_ssockf_csock_cases() ->
+    [
+     {group, ttest_ssockf_csockf},
+     {group, ttest_ssockf_csocko},
+     {group, ttest_ssockf_csockt}
+    ].
+
+%% Server: transport = socket(tcp), active = false
+%% Client: transport = socket(tcp), active = false
+ttest_ssockf_csockf_cases() ->
+    [
+     ttest_ssockf_csockf_small_tcp4,
+     ttest_ssockf_csockf_small_tcp6,
+     ttest_ssockf_csockf_small_tcpL,
+
+     ttest_ssockf_csockf_medium_tcp4,
+     ttest_ssockf_csockf_medium_tcp6,
+     ttest_ssockf_csockf_medium_tcpL,
+
+     ttest_ssockf_csockf_large_tcp4,
+     ttest_ssockf_csockf_large_tcp6,
+     ttest_ssockf_csockf_large_tcpL
+    ].
+
+%% Server: transport = socket(tcp), active = false
+%% Client: transport = socket(tcp), active = once
+ttest_ssockf_csocko_cases() ->
+    [
+     ttest_ssockf_csocko_small_tcp4,
+     ttest_ssockf_csocko_small_tcp6,
+     ttest_ssockf_csocko_small_tcpL,
+
+     ttest_ssockf_csocko_medium_tcp4,
+     ttest_ssockf_csocko_medium_tcp6,
+     ttest_ssockf_csocko_medium_tcpL,
+
+     ttest_ssockf_csocko_large_tcp4,
+     ttest_ssockf_csocko_large_tcp6,
+     ttest_ssockf_csocko_large_tcpL
+    ].
+
+%% Server: transport = socket(tcp), active = false
+%% Client: transport = socket(tcp), active = true
+ttest_ssockf_csockt_cases() ->
+    [
+     ttest_ssockf_csockt_small_tcp4,
+     ttest_ssockf_csockt_small_tcp6,
+     ttest_ssockf_csockt_small_tcpL,
+
+     ttest_ssockf_csockt_medium_tcp4,
+     ttest_ssockf_csockt_medium_tcp6,
+     ttest_ssockf_csockt_medium_tcpL,
+
+     ttest_ssockf_csockt_large_tcp4,
+     ttest_ssockf_csockt_large_tcp6,
+     ttest_ssockf_csockt_large_tcpL
+    ].
+
+%% Server: transport = socket(tcp), active = once
+ttest_ssocko_cases() ->
+    [
+     {group, ttest_ssocko_cgen},
+     {group, ttest_ssocko_csock}
+    ].
+
+%% Server: transport = socket(tcp), active = once
+%% Client: transport = gen_tcp
+ttest_ssocko_cgen_cases() ->
+    [
+     {group, ttest_ssocko_cgenf},
+     {group, ttest_ssocko_cgeno},
+     {group, ttest_ssocko_cgent}
+    ].
+
+%% Server: transport = socket(tcp), active = once
+%% Client: transport = gen_tcp, active = false
+ttest_ssocko_cgenf_cases() ->
+    [
+     ttest_ssocko_cgenf_small_tcp4,
+     ttest_ssocko_cgenf_small_tcp6,
+
+     ttest_ssocko_cgenf_medium_tcp4,
+     ttest_ssocko_cgenf_medium_tcp6,
+
+     ttest_ssocko_cgenf_large_tcp4,
+     ttest_ssocko_cgenf_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = once
+%% Client: transport = gen_tcp, active = once
+ttest_ssocko_cgeno_cases() ->
+    [
+     ttest_ssocko_cgeno_small_tcp4,
+     ttest_ssocko_cgeno_small_tcp6,
+
+     ttest_ssocko_cgeno_medium_tcp4,
+     ttest_ssocko_cgeno_medium_tcp6,
+
+     ttest_ssocko_cgeno_large_tcp4,
+     ttest_ssocko_cgeno_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = once
+%% Client: transport = gen_tcp, active = true
+ttest_ssocko_cgent_cases() ->
+    [
+     ttest_ssocko_cgent_small_tcp4,
+     ttest_ssocko_cgent_small_tcp6,
+
+     ttest_ssocko_cgent_medium_tcp4,
+     ttest_ssocko_cgent_medium_tcp6,
+
+     ttest_ssocko_cgent_large_tcp4,
+     ttest_ssocko_cgent_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = once
+%% Client: transport = socket(tcp)
+ttest_ssocko_csock_cases() ->
+    [
+     {group, ttest_ssocko_csockf},
+     {group, ttest_ssocko_csocko},
+     {group, ttest_ssocko_csockt}
+    ].
+
+%% Server: transport = socket(tcp), active = once
+%% Client: transport = socket(tcp), active = false
+ttest_ssocko_csockf_cases() ->
+    [
+     ttest_ssocko_csockf_small_tcp4,
+     ttest_ssocko_csockf_small_tcp6,
+     ttest_ssocko_csockf_small_tcpL,
+
+     ttest_ssocko_csockf_medium_tcp4,
+     ttest_ssocko_csockf_medium_tcp6,
+     ttest_ssocko_csockf_medium_tcpL,
+
+     ttest_ssocko_csockf_large_tcp4,
+     ttest_ssocko_csockf_large_tcp6,
+     ttest_ssocko_csockf_large_tcpL
+    ].
+
+%% Server: transport = socket(tcp), active = once
+%% Client: transport = socket(tcp), active = once
+ttest_ssocko_csocko_cases() ->
+    [
+     ttest_ssocko_csocko_small_tcp4,
+     ttest_ssocko_csocko_small_tcp6,
+     ttest_ssocko_csocko_small_tcpL,
+
+     ttest_ssocko_csocko_medium_tcp4,
+     ttest_ssocko_csocko_medium_tcp6,
+     ttest_ssocko_csocko_medium_tcpL,
+
+     ttest_ssocko_csocko_large_tcp4,
+     ttest_ssocko_csocko_large_tcp6,
+     ttest_ssocko_csocko_large_tcpL
+    ].
+
+%% Server: transport = socket(tcp), active = once
+%% Client: transport = socket(tcp), active = true
+ttest_ssocko_csockt_cases() ->
+    [
+     ttest_ssocko_csockt_small_tcp4,
+     ttest_ssocko_csockt_small_tcp6,
+     ttest_ssocko_csockt_small_tcpL,
+
+     ttest_ssocko_csockt_medium_tcp4,
+     ttest_ssocko_csockt_medium_tcp6,
+     ttest_ssocko_csockt_medium_tcpL,
+
+     ttest_ssocko_csockt_large_tcp4,
+     ttest_ssocko_csockt_large_tcp6,
+     ttest_ssocko_csockt_large_tcpL
+    ].
+
+%% Server: transport = socket(tcp), active = true
+ttest_ssockt_cases() ->
+    [
+     {group, ttest_ssockt_cgen},
+     {group, ttest_ssockt_csock}
+    ].
+
+%% Server: transport = socket(tcp), active = true
+%% Client: transport = gen_tcp
+ttest_ssockt_cgen_cases() ->
+    [
+     {group, ttest_ssockt_cgenf},
+     {group, ttest_ssockt_cgeno},
+     {group, ttest_ssockt_cgent}
+    ].
+
+%% Server: transport = socket(tcp), active = true
+%% Client: transport = gen_tcp, active = false
+ttest_ssockt_cgenf_cases() ->
+    [
+     ttest_ssockt_cgenf_small_tcp4,
+     ttest_ssockt_cgenf_small_tcp6,
+
+     ttest_ssockt_cgenf_medium_tcp4,
+     ttest_ssockt_cgenf_medium_tcp6,
+
+     ttest_ssockt_cgenf_large_tcp4,
+     ttest_ssockt_cgenf_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = true
+%% Client: transport = gen_tcp, active = once
+ttest_ssockt_cgeno_cases() ->
+    [
+     ttest_ssockt_cgeno_small_tcp4,
+     ttest_ssockt_cgeno_small_tcp6,
+
+     ttest_ssockt_cgeno_medium_tcp4,
+     ttest_ssockt_cgeno_medium_tcp6,
+
+     ttest_ssockt_cgeno_large_tcp4,
+     ttest_ssockt_cgeno_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = true
+%% Client: transport = gen_tcp, active = true
+ttest_ssockt_cgent_cases() ->
+    [
+     ttest_ssockt_cgent_small_tcp4,
+     ttest_ssockt_cgent_small_tcp6,
+
+     ttest_ssockt_cgent_medium_tcp4,
+     ttest_ssockt_cgent_medium_tcp6,
+
+     ttest_ssockt_cgent_large_tcp4,
+     ttest_ssockt_cgent_large_tcp6
+    ].
+
+%% Server: transport = socket(tcp), active = true
+%% Client: transport = socket(tcp)
+ttest_ssockt_csock_cases() ->
+    [
+     {group, ttest_ssockt_csockf},
+     {group, ttest_ssockt_csocko},
+     {group, ttest_ssockt_csockt}
+    ].
+
+%% Server: transport = socket(tcp), active = true
+%% Client: transport = socket(tcp), active = false
+ttest_ssockt_csockf_cases() ->
+    [
+     ttest_ssockt_csockf_small_tcp4,
+     ttest_ssockt_csockf_small_tcp6,
+     ttest_ssockt_csockf_small_tcpL,
+
+     ttest_ssockt_csockf_medium_tcp4,
+     ttest_ssockt_csockf_medium_tcp6,
+     ttest_ssockt_csockf_medium_tcpL,
+
+     ttest_ssockt_csockf_large_tcp4,
+     ttest_ssockt_csockf_large_tcp6,
+     ttest_ssockt_csockf_large_tcpL
+    ].
+
+%% Server: transport = socket(tcp), active = true
+%% Client: transport = socket(tcp), active = once
+ttest_ssockt_csocko_cases() ->
+    [
+     ttest_ssockt_csocko_small_tcp4,
+     ttest_ssockt_csocko_small_tcp6,
+     ttest_ssockt_csocko_small_tcpL,
+
+     ttest_ssockt_csocko_medium_tcp4,
+     ttest_ssockt_csocko_medium_tcp6,
+     ttest_ssockt_csocko_medium_tcpL,
+
+     ttest_ssockt_csocko_large_tcp4,
+     ttest_ssockt_csocko_large_tcp6,
+     ttest_ssockt_csocko_large_tcpL
+    ].
+
+%% Server: transport = socket(tcp), active = true
+%% Client: transport = socket(tcp), active = true
+ttest_ssockt_csockt_cases() ->
+    [
+     ttest_ssockt_csockt_small_tcp4,
+     ttest_ssockt_csockt_small_tcp6,
+     ttest_ssockt_csockt_small_tcpL,
+
+     ttest_ssockt_csockt_medium_tcp4,
+     ttest_ssockt_csockt_medium_tcp6,
+     ttest_ssockt_csockt_medium_tcpL,
+
+     ttest_ssockt_csockt_large_tcp4,
+     ttest_ssockt_csockt_large_tcp6,
+     ttest_ssockt_csockt_large_tcpL
+    ].
+
+%% ticket_cases() ->
+%%     [].
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+init_per_suite(Config) ->
+    case lists:member(socket, erlang:loaded()) of
+        true ->
+            case os:type() of
+                {win32, _} ->
+                    (catch not_yet_implemented());
+                _ ->
+                    case quiet_mode(Config) of
+                        default ->
+                            ?LOGGER:start(),
+                            Config;
+                        Quiet ->
+                            ?LOGGER:start(Quiet),
+                            [{esock_test_quiet, Quiet}|Config]
+                    end
+            end;
+        false ->
+            {skip, "esock disabled"}
+    end.
+
+end_per_suite(_) ->
+    (catch ?LOGGER:stop()),
+    ok.
+
+
+init_per_group(ttest = _GroupName, Config) ->
+    io:format("init_per_group(~w) -> entry with"
+              "~n   Config: ~p"
+              "~n", [_GroupName, Config]),
+    ttest_manager_start(),
+    case lists:keysearch(esock_test_ttest_runtime, 1, Config) of
+        {value, _} ->
+            Config;
+        false ->
+            [{esock_test_ttest_runtime, which_ttest_runtime_env()} | Config]
+    end;
+init_per_group(_GroupName, Config) ->
+    Config.
+
+end_per_group(ttest = _GroupName, Config) ->
+    io:format("init_per_group(~w) -> entry with"
+              "~n   Config: ~p"
+              "~n", [_GroupName, Config]),
+    ttest_manager_stop(),
+    lists:keydelete(esock_test_ttest_runtime, 1, Config);
+end_per_group(_GroupName, Config) ->
+    Config.
+
+
+init_per_testcase(_TC, Config) ->
+    io:format("init_per_testcase(~w) -> entry with"
+              "~n   Config: ~p"
+              "~n", [_TC, Config]),
+    %% case quiet_mode(Config) of
+    %%     default ->
+    %%         ?LOGGER:start();
+    %%     Quiet ->
+    %%         ?LOGGER:start(Quiet)
+    %% end,
+    Config.
+
+end_per_testcase(_TC, Config) ->
+    %% ?LOGGER:stop(),
+    Config.
+
+
+quiet_mode(Config) ->
+    case lists:keysearch(esock_test_quiet, 1, Config) of
+        {value, {esock_test_quiet, Quiet}} ->
+            Quiet;
+        false ->
+            case os:getenv("ESOCK_TEST_QUIET") of
+                "true"  -> true;
+                "false" -> false;
+                _       -> default
+            end
+    end.
+
+
+                
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%                                                                     %%
+%%                           API MISC                                  %%
+%%                                                                     %%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% A simple test case that tests that the global debug can be channged.
+%% At the same time, it will test the info function (since it uses it
+%% for verification).
+
+api_m_debug(suite) ->
+    [];
+api_m_debug(doc) ->
+    [];
+api_m_debug(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_m_debug,
+           fun() -> has_bugfree_gcc() end,
+           fun() ->
+                   ok = api_m_debug()
+           end).
+
+%% For some reason this test case triggers a gcc bug, which causes
+%% a segfault, on an ancient Fedora 16 VM. So, check the version of gcc...
+%% Not pretty, but the simplest way to skip (without actually testing for the host).
+has_bugfree_gcc() ->
+    has_bugfree_gcc(os:type()).
+
+%% Make sure we are on linux
+has_bugfree_gcc({unix, linux}) ->
+    has_bugfree_gcc2(string:trim(os:cmd("cat /etc/issue")));
+has_bugfree_gcc(_) ->
+    ok.
+
+%% Make sure we are on Fedora 16
+has_bugfree_gcc2("Fedora release 16 " ++ _) ->
+    has_bugfree_gcc3(os:cmd("gcc --version"));
+has_bugfree_gcc2("Welcome to SUSE Linux " ++ _) ->
+    has_bugfree_gcc4(os:cmd("gcc --version"));
+has_bugfree_gcc2(_) ->
+    ok.
+
+has_bugfree_gcc3("gcc (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2" ++ _) ->
+    skip("Buggy GCC");
+has_bugfree_gcc3(_) ->
+    ok.
+
+has_bugfree_gcc4("gcc (SUSE Linux) 4.3.2" ++ _) ->
+    skip("Buggy GCC");
+has_bugfree_gcc4(_) ->
+    ok.
+
+api_m_debug() ->
+    i("get initial info"),
+    #{debug := D0} = socket:info(),
+    D1 = not D0,
+    i("set new debug (~w => ~w)", [D0, D1]),
+    ok = socket:debug(D1),
+    i("get updated info (~w)", [D1]),
+    #{debug := D1} = socket:info(),
+    D2 = not D1,
+    i("set new debug (~w => ~w)", [D1, D2]),
+    ok = socket:debug(D2),
+    i("get updated info (~w)", [D2]),
+    #{debug := D2} = socket:info(),
+    i("ok"),
+    ok.
+    
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%                                                                     %%
+%%                           API BASIC                                 %%
+%%                                                                     %%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically open (create) and close an IPv4 UDP (dgram) socket.
+%% With some extra checks...
+api_b_open_and_close_udp4(suite) ->
+    [];
+api_b_open_and_close_udp4(doc) ->
+    [];
+api_b_open_and_close_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_open_and_close_udp4,
+           fun() ->
+                   InitState = #{domain   => inet,
+                                 type     => dgram,
+                                 protocol => udp},
+                   ok = api_b_open_and_close(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically open (create) and close an IPv4 TCP (stream) socket.
+%% With some extra checks...
+api_b_open_and_close_tcp4(suite) ->
+    [];
+api_b_open_and_close_tcp4(doc) ->
+    [];
+api_b_open_and_close_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_open_and_close_tcp4,
+           fun() ->
+                   InitState = #{domain   => inet,
+                                 type     => stream,
+                                 protocol => tcp},
+                   ok = api_b_open_and_close(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically open (create) and close an Unix Domain dgram (UDP) socket.
+%% With some extra checks...
+api_b_open_and_close_udpL(suite) ->
+    [];
+api_b_open_and_close_udpL(doc) ->
+    [];
+api_b_open_and_close_udpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_open_and_close_udpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain   => local,
+                                 type     => dgram,
+                                 protocol => default},
+                   ok = api_b_open_and_close(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically open (create) and close an Unix Domain stream (TCP) socket.
+%% With some extra checks...
+api_b_open_and_close_tcpL(suite) ->
+    [];
+api_b_open_and_close_tcpL(doc) ->
+    [];
+api_b_open_and_close_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_open_and_close_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain   => local,
+                                 type     => stream,
+                                 protocol => default},
+                   ok = api_b_open_and_close(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_b_open_and_close(InitState) ->
+    Seq = 
+        [
+         #{desc => "open",
+           cmd  => fun(#{domain   := Domain,
+                         type     := Type,
+                         protocol := Protocol} = S) -> 
+                           Res = socket:open(Domain, Type, Protocol), 
+                           {ok, {S, Res}} 
+                   end},
+         #{desc => "validate open",
+           cmd  => fun({S, {ok, Sock}}) -> 
+                           NewS = S#{socket => Sock},
+                           {ok, NewS};
+                      ({_, {error, _} = ERROR}) ->
+                           ERROR
+                   end},
+         #{desc => "get domain (maybe)",
+           cmd  => fun(#{socket := Sock} = S) ->
+                           Res = socket:getopt(Sock, socket, domain),
+                           {ok, {S, Res}}
+                   end},
+         #{desc => "validate domain (maybe)",
+           cmd  => fun({#{domain := Domain} = S, {ok, Domain}}) -> 
+                           {ok, S};
+                      ({#{domain := ExpDomain}, {ok, Domain}}) ->
+                           {error, {unexpected_domain, ExpDomain, Domain}};
+                      %% Some platforms do not support this option
+                      ({S, {error, einval}}) ->
+                           {ok, S};
+                      ({_, {error, _} = ERROR}) ->
+                           ERROR
+                   end},
+         #{desc => "get type",
+           cmd  => fun(#{socket := Sock} = State) ->
+                           Res = socket:getopt(Sock, socket, type), 
+                           {ok, {State, Res}}
+                   end},
+         #{desc => "validate type",
+           cmd  => fun({#{type := Type} = State, {ok, Type}}) ->
+                           {ok, State};
+                      ({#{type := ExpType}, {ok, Type}}) ->
+                           {error, {unexpected_type, ExpType, Type}};
+                      ({_, {error, _} = ERROR}) ->
+                           ERROR
+                   end},
+         #{desc => "get protocol",
+           cmd  => fun(#{socket := Sock} = State) ->
+			   case socket:supports(options, socket, protocol) of
+			       true ->
+				   Res = socket:getopt(Sock, socket, protocol),
+				   {ok, {State, Res}};
+			       false ->
+				   {ok, {State, not_supported}}
+			   end
+                   end},
+         #{desc => "validate protocol",
+           cmd  => fun({State, not_supported}) ->
+			   ?SEV_IPRINT("socket option 'protocol' "
+				       "not supported"),
+                           {ok, State};
+                      ({#{protocol := Protocol} = State, {ok, Protocol}}) ->
+                           {ok, State};
+                      ({#{protocol := ExpProtocol}, {ok, Protocol}}) ->
+                           {error, {unexpected_type, ExpProtocol, Protocol}};
+                      ({_, {error, _} = ERROR}) ->
+                           ERROR
+                   end},
+         #{desc => "get controlling-process",
+           cmd  => fun(#{socket := Sock} = State) ->
+                           Res = socket:getopt(Sock, otp, controlling_process),
+                           {ok, {State, Res}}
+                   end},
+         #{desc => "validate controlling-process",
+           cmd  => fun({State, {ok, Pid}}) ->
+                           case self() of
+                               Pid ->
+                                   {ok, State};
+                               _ ->
+                                   {error, {unexpected_owner, Pid}}
+                           end;
+                      ({_, {error, _} = ERROR}) ->
+                           ERROR
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{socket := Sock} = State) ->
+                           Res = socket:close(Sock),
+                           {ok, {State, Res}}
+                   end},
+         #{desc => "validate socket close",
+           cmd  => fun({_, ok}) ->
+                           ok;
+                      ({_, {error, _} = ERROR}) ->
+                           ERROR
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+    Evaluator = ?SEV_START("tester", Seq, InitState),
+    ok = ?SEV_AWAIT_FINISH([Evaluator]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive on an IPv4 UDP (dgram) socket using
+%% sendto and recvfrom..
+api_b_sendto_and_recvfrom_udp4(suite) ->
+    [];
+api_b_sendto_and_recvfrom_udp4(doc) ->
+    [];
+api_b_sendto_and_recvfrom_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_sendto_and_recvfrom_udp4,
+           fun() ->
+                   Send = fun(Sock, Data, Dest) ->
+                                  socket:sendto(Sock, Data, Dest)
+                          end,
+                   Recv = fun(Sock) ->
+                                  socket:recvfrom(Sock)
+                          end,
+                   InitState = #{domain => inet,
+                                 proto  => udp,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_b_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive on an IPv4 UDP (dgram) socket using
+%% sendto and recvfrom.
+api_b_sendto_and_recvfrom_udpL(suite) ->
+    [];
+api_b_sendto_and_recvfrom_udpL(doc) ->
+    [];
+api_b_sendto_and_recvfrom_udpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_sendto_and_recvfrom_udpL,
+           fun() ->
+                   has_support_unix_domain_socket(),
+                   unix_domain_socket_host_cond()
+           end,
+           fun() ->
+                   Send = fun(Sock, Data, Dest) ->
+                                  socket:sendto(Sock, Data, Dest)
+                          end,
+                   Recv = fun(Sock) ->
+                                  socket:recvfrom(Sock)
+                          end,
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_b_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive on an IPv4 UDP (dgram) socket
+%% using sendmsg and recvmsg.
+api_b_sendmsg_and_recvmsg_udp4(suite) ->
+    [];
+api_b_sendmsg_and_recvmsg_udp4(doc) ->
+    [];
+api_b_sendmsg_and_recvmsg_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_sendmsg_and_recvmsg_udp4,
+           fun() ->
+                   Send = fun(Sock, Data, Dest) ->
+                                  %% We need tests for this,
+                                  %% but this is not the place it.
+                                  %% CMsgHdr  = #{level => ip,
+                                  %%              type  => tos,
+                                  %%              data  => reliability},
+                                  %% CMsgHdrs = [CMsgHdr],
+                                  MsgHdr = #{addr => Dest,
+                                             %% ctrl => CMsgHdrs,
+                                             iov  => [Data]},
+                                  socket:sendmsg(Sock, MsgHdr)
+                          end,
+                   Recv = fun(Sock) ->
+                                  %% We have some issues on old darwing...
+                                  %% socket:setopt(Sock, otp, debug, true),
+                                  case socket:recvmsg(Sock) of
+                                      {ok, #{addr  := Source,
+                                             iov   := [Data]}} ->
+                                          %% socket:setopt(Sock, otp, debug, false),
+                                          {ok, {Source, Data}};
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet,
+                                 proto  => udp,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_b_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive on an IPv4 UDP (dgram) socket
+%% using sendmsg and recvmsg.
+api_b_sendmsg_and_recvmsg_udpL(suite) ->
+    [];
+api_b_sendmsg_and_recvmsg_udpL(doc) ->
+    [];
+api_b_sendmsg_and_recvmsg_udpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_b_sendmsg_and_recvmsg_udpL,
+           fun() ->
+                   has_support_unix_domain_socket(),
+                   unix_domain_socket_host_cond()
+           end,
+           fun() ->
+                   Send = fun(Sock, Data, Dest) ->
+                                  %% We need tests for this,
+                                  %% but this is not the place it.
+                                  %% CMsgHdr  = #{level => ip,
+                                  %%              type  => tos,
+                                  %%              data  => reliability},
+                                  %% CMsgHdrs = [CMsgHdr],
+                                  MsgHdr = #{addr => Dest,
+                                             %% ctrl => CMsgHdrs,
+                                             iov  => [Data]},
+                                  socket:sendmsg(Sock, MsgHdr)
+                          end,
+                   Recv = fun(Sock) ->
+                                  %% We have some issues on old darwing...
+                                  %% socket:setopt(Sock, otp, debug, true),
+                                  case socket:recvmsg(Sock) of
+                                      {ok, #{addr  := Source,
+                                             iov   := [Data]}} ->
+                                          %% socket:setopt(Sock, otp, debug, false),
+                                          {ok, {Source, Data}};
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_b_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_b_send_and_recv_udp(InitState) ->
+    Seq = 
+        [
+         #{desc => "local address",
+           cmd  => fun(#{domain := local = Domain} = State) ->
+                           LSASrc = which_local_socket_addr(Domain),
+                           LSADst = which_local_socket_addr(Domain),
+                           {ok, State#{lsa_src => LSASrc,
+                                       lsa_dst => LSADst}};
+                      (#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa_src => LSA,
+                                       lsa_dst => LSA}}
+                   end},
+
+         #{desc => "open src socket",
+           cmd  => fun(#{domain := Domain,
+                         proto  := Proto} = State) ->
+                           Sock = sock_open(Domain, dgram, Proto),
+                           {ok, State#{sock_src => Sock}}
+                   end},
+         #{desc => "bind src",
+           cmd  => fun(#{sock_src := Sock, lsa_src := LSA}) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ?SEV_IPRINT("src bound"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("src bind failed: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "sockname src socket",
+           cmd  => fun(#{sock_src := Sock} = State) ->
+                           SASrc = sock_sockname(Sock),
+                           ?SEV_IPRINT("src sockaddr: "
+                                       "~n   ~p", [SASrc]),
+                           {ok, State#{sa_src => SASrc}}
+                   end},
+
+         #{desc => "open dst socket",
+           cmd  => fun(#{domain := Domain,
+                         proto  := Proto} = State) ->
+                           Sock = sock_open(Domain, dgram, Proto),
+                           {ok, State#{sock_dst => Sock}}
+                   end},
+         #{desc => "bind dst",
+           cmd  => fun(#{sock_dst := Sock, lsa_dst := LSA}) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ?SEV_IPRINT("src bound"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("src bind failed: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "sockname dst socket",
+           cmd  => fun(#{sock_dst := Sock} = State) ->
+                           SADst = sock_sockname(Sock),
+                           ?SEV_IPRINT("dst sockaddr: "
+                                       "~n   ~p", [SADst]),
+                           {ok, State#{sa_dst => SADst}}
+                   end},
+         #{desc => "send req (to dst)",
+           cmd  => fun(#{sock_src := Sock, sa_dst := Dst, send := Send}) ->
+                           Send(Sock, ?BASIC_REQ, Dst)
+                   end},
+         #{desc => "recv req (from src)",
+           cmd  => fun(#{sock_dst := Sock, sa_src := Src, recv := Recv}) ->
+                           case Recv(Sock) of
+                               {ok, {Src, ?BASIC_REQ}} ->
+                                   ok;
+                               {ok, UnexpData} ->
+                                   {error, {unexpected_data, UnexpData}};
+                               {error, _} = ERROR ->
+                                   %% At the moment there is no way to get
+                                   %% status or state for the socket...
+                                   ERROR
+                           end
+                   end},
+         #{desc => "send rep (to src)",
+           cmd  => fun(#{sock_dst := Sock, sa_src := Src, send := Send}) ->
+                           Send(Sock, ?BASIC_REP, Src)
+                   end},
+         #{desc => "recv rep (from dst)",
+           cmd  => fun(#{sock_src := Sock, sa_dst := Dst, recv := Recv}) ->
+                           case Recv(Sock) of
+                               {ok, {Dst, ?BASIC_REP}} ->
+                                   ok;
+                               {ok, UnexpData} ->
+                                   {error, {unexpected_data, UnexpData}};
+                               {error, _} = ERROR ->
+                                   %% At the moment there is no way to get
+                                   %% status or state for the socket...
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close src socket",
+           cmd  => fun(#{domain   := local,
+                         sock_src := Sock,
+                         lsa_src  := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() -> maps:remove(lsa_src, State) end,
+                                           fun() -> State end),
+                           {ok, maps:remove(sock_src, State1)};
+                      (#{sock_src := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(sock_src, State)}
+                   end},
+         #{desc => "close dst socket",
+           cmd  => fun(#{domain   := local,
+                         sock_dst := Sock,
+                         lsa_dst  := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() -> maps:remove(lsa_dst, State) end,
+                                           fun() -> State end),
+                           {ok, maps:remove(sock_dst, State1)};
+                      (#{sock_dst := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(sock_dst, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+    Evaluator = ?SEV_START("tester", Seq, InitState),
+    ok = ?SEV_AWAIT_FINISH([Evaluator]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive using the "common" functions (send and recv)
+%% on an IPv4 TCP (stream) socket.
+api_b_send_and_recv_tcp4(suite) ->
+    [];
+api_b_send_and_recv_tcp4(doc) ->
+    [];
+api_b_send_and_recv_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_b_send_and_recv_tcp4,
+           fun() ->
+                   Send = fun(Sock, Data) ->
+                                  socket:send(Sock, Data)
+                          end,
+                   Recv = fun(Sock) ->
+                                  socket:recv(Sock)
+                          end,
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_b_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive using the "common" functions (send and recv)
+%% on an Unix Domain (stream) socket (TCP).
+api_b_send_and_recv_tcpL(suite) ->
+    [];
+api_b_send_and_recv_tcpL(doc) ->
+    [];
+api_b_send_and_recv_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_b_send_and_recv_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   Send = fun(Sock, Data) ->
+                                  socket:send(Sock, Data)
+                          end,
+                   Recv = fun(Sock) ->
+                                  socket:recv(Sock)
+                          end,
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_b_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive using the msg functions (sendmsg and recvmsg)
+%% on an IPv4 TCP (stream) socket.
+api_b_sendmsg_and_recvmsg_tcp4(suite) ->
+    [];
+api_b_sendmsg_and_recvmsg_tcp4(doc) ->
+    [];
+api_b_sendmsg_and_recvmsg_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_b_sendmsg_and_recvmsg_tcp4,
+           fun() ->
+                   Send = fun(Sock, Data) ->
+                                  MsgHdr = #{iov => [Data]},
+                                  socket:sendmsg(Sock, MsgHdr)
+                          end,
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock) of
+                                      {ok, #{addr  := undefined,
+                                             iov   := [Data]}} ->
+                                          {ok, Data};
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_b_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive using the msg functions (sendmsg and recvmsg)
+%% on an Unix Domain (stream) socket (TCP).
+api_b_sendmsg_and_recvmsg_tcpL(suite) ->
+    [];
+api_b_sendmsg_and_recvmsg_tcpL(doc) ->
+    [];
+api_b_sendmsg_and_recvmsg_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_b_sendmsg_and_recvmsg_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   Send = fun(Sock, Data) ->
+                                  MsgHdr = #{iov => [Data]},
+                                  socket:sendmsg(Sock, MsgHdr)
+                          end,
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock) of
+                                      %% On some platforms, the address
+                                      %% is *not* provided (e.g. FreeBSD)
+                                      {ok, #{addr  := undefined,
+                                             iov   := [Data]}} ->
+                                          {ok, Data};
+                                      %% On some platforms, the address
+                                      %% *is* provided (e.g. linux)
+                                      {ok, #{addr  := #{family := local},
+                                             iov   := [Data]}} ->
+                                          socket:setopt(Sock, 
+                                                        otp, 
+                                                        debug, 
+                                                        false),
+                                          {ok, Data};
+                                      {error, _} = ERROR ->
+                                          socket:setopt(Sock, 
+                                                        otp, 
+                                                        debug, 
+                                                        false),
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_b_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_b_send_and_recv_tcp(InitState) ->
+    process_flag(trap_exit, true),
+    ServerSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain,
+                         proto  := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{domain := local,
+                         lsock  := LSock,
+                         lsa    := LSA} = _State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, _Port} ->
+                                   ok; % We do not care about the port for local
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{lsock := LSock, lsa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   ?SEV_IPRINT("bound to port: ~w", [Port]),
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain := local,
+                         tester := Tester, lsa := #{path := Path}}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Path),
+                           ok;
+                      (#{tester := Tester, lport := Port}) ->
+                           %% This is actually not used for unix domain socket
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "await connection",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   ?SEV_IPRINT("accepted: ~n   ~p", [Sock]),
+                                   {ok, State#{csock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+         #{desc => "await (recv) request",
+           cmd  => fun(#{csock := Sock, recv := Recv}) ->
+                           case Recv(Sock) of
+                               {ok, ?BASIC_REQ} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv request)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_req),
+                           ok
+                   end},
+         #{desc => "await continue (with send reply)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_reply)
+                   end},
+         #{desc => "send reply",
+           cmd  => fun(#{csock := Sock, send := Send}) ->
+                           Send(Sock, ?BASIC_REP)
+                   end},
+         #{desc => "announce ready (send reply)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_reply),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close connection socket",
+           cmd  => fun(#{csock := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(csock, State)}
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{domain   := local,
+                         lsock    := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(lsock, State1)};
+                      (#{lsock := LSock} = State) ->
+                           case socket:close(LSock) of
+                               ok ->
+                                   {ok, maps:remove(lsock, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(#{domain := local} = State) ->
+                           {Tester, Path} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_path => Path}};
+                      (State) ->
+                           {Tester, Port} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_port => Port}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** The init part ***
+         #{desc => "which server (local) address",
+           cmd  => fun(#{domain      := local = Domain,
+                         server_path := Path} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = #{family => Domain, path => Path},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}};
+                      (#{domain := Domain, server_port := Port} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = LSA#{port => Port},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain,
+                         proto  := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect)
+                   end},
+         #{desc => "connect to server",
+           cmd  => fun(#{sock := Sock, server_sa := SSA}) ->
+                           socket:connect(Sock, SSA)
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+         #{desc => "await continue (send request)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_req)
+                   end},
+         #{desc => "send request (to server)",
+           cmd  => fun(#{sock := Sock, send := Send}) ->
+                           Send(Sock, ?BASIC_REQ)
+                   end},
+         #{desc => "announce ready (send request)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_req),
+                           ok
+                   end},
+         #{desc => "await recv reply (from server)",
+           cmd  => fun(#{sock := Sock, recv := Recv}) ->
+                           {ok, ?BASIC_REP} = Recv(Sock),
+                           ok
+                   end},
+         #{desc => "announce ready (recv reply)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_reply),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{domain   := local,
+                         sock     := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(sock, State1)};
+                      (#{sock := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_port => Port}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client := Pid, server_port := Port} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Port),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "order server to continue (with accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, accept),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client to continue (with connect)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, connect),
+                           ok
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, connect)
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, accept)
+                   end},
+         #{desc => "order client to continue (with send request)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send_req),
+                           ok
+                   end},
+         #{desc => "await client ready (with send request)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, send_req)
+                   end},
+         #{desc => "await server ready (request recv)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, recv_req)
+                   end},
+         #{desc => "order server to continue (with send reply)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, send_reply),
+                           ok
+                   end},
+         #{desc => "await server ready (with reply sent)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, send_reply)
+                   end},
+         #{desc => "await client ready (reply recv)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, recv_reply)
+                   end},
+
+
+         %% *** Termination ***
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client, State),
+                           {ok, State1}
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server, State),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    Server = ?SEV_START("server", ServerSeq, InitState),
+
+    i("start client evaluator"),
+    Client = ?SEV_START("client", ClientSeq, InitState),
+    i("await evaluator(s)"),
+
+    i("start tester evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically establish a TCP connection via an async connect. IPv4.
+
+api_a_connect_tcp4(suite) ->
+    [];
+api_a_connect_tcp4(doc) ->
+    [];
+api_a_connect_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_connect_tcp4,
+           fun() ->
+                   ok = api_a_connect_tcpD(inet)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically establish a TCP connection via an async connect. IPv6.
+
+api_a_connect_tcp6(suite) ->
+    [];
+api_a_connect_tcp6(doc) ->
+    [];
+api_a_connect_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_connect_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ok = api_a_connect_tcpD(inet6)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_connect_tcpD(Domain) ->
+    Connect = fun(Sock, SockAddr) ->
+                      socket:connect(Sock, SockAddr, nowait)
+              end,
+    Send = fun(Sock, Data) ->
+                   socket:send(Sock, Data)
+           end,
+    Recv = fun(Sock) ->
+                   socket:recv(Sock)
+           end,
+    InitState = #{domain  => Domain,
+                  connect => Connect,
+                  send    => Send,
+                  recv    => Recv},
+    api_a_connect_tcp(InitState).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_connect_tcp(InitState) ->
+    process_flag(trap_exit, true),
+    ServerSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, lsa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, lport := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "await connection",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   ?SEV_IPRINT("accepted: ~n   ~p", [Sock]),
+                                   {ok, State#{csock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv_req)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_req)
+                   end},
+         #{desc => "recv req",
+           cmd  => fun(#{csock := Sock, recv := Recv}) ->
+                           case Recv(Sock) of
+                               {ok, ?BASIC_REQ} ->
+                                   ok;
+                               {ok, UnexpData} ->
+                                   {error, {unexpected_data, UnexpData}};
+                               {error, _} = ERROR ->
+                                   %% At the moment there is no way to get
+                                   %% status or state for the socket...
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_req)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_req),
+                           ok
+                   end},
+         #{desc => "await continue (send_rep)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_rep)
+                   end},
+         #{desc => "send rep",
+           cmd  => fun(#{csock := Sock, send := Send}) ->
+                           Send(Sock, ?BASIC_REP)
+                   end},
+         #{desc => "announce ready (send_rep)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_rep),
+                           ok
+                   end},
+	 
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close connection socket",
+           cmd  => fun(#{csock := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(csock, State)}
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{lsock := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(lsock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           {Tester, Port} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_port => Port}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** The init part ***
+         #{desc => "which server (local) address",
+           cmd  => fun(#{domain := Domain, server_port := Port} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = LSA#{port => Port},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "await continue (async connect)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, async_connect)
+                   end},
+         #{desc => "connect (async) to server",
+           cmd  => fun(#{sock      := Sock,
+                         server_sa := SSA,
+                         connect   := Connect} = State) ->
+                           case Connect(Sock, SSA) of
+                               ok ->
+                                   ?SEV_IPRINT("ok -> "
+					       "unexpected success => SKIP", 
+                                               []),
+                                   {skip, unexpected_success};
+                               {select, {select_info, ST, SR}} ->
+                                   ?SEV_IPRINT("select ->"
+                                               "~n   tag: ~p"
+                                               "~n   ref: ~p", [ST, SR]),
+                                   {ok, State#{connect_stag => ST,
+                                               connect_sref => SR}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (connect select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect_select),
+                           ok
+                   end},
+         #{desc => "await select message",
+           cmd  => fun(#{sock := Sock, connect_sref := Ref}) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   ?SEV_IPRINT("select message ->"
+                                               "~n   ref: ~p", [Ref]),
+                                   ok
+                           after 5000 ->
+                                   ?SEV_EPRINT("timeout: "
+                                               "~n   message queue: ~p",
+                                               [mq()]),
+                                   {error, timeout}
+                           end
+                   end},
+         #{desc => "announce ready (select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, select),
+                           ok
+                   end},
+         #{desc => "connect (async) to server",
+           cmd  => fun(#{sock := Sock, server_sa := SSA, connect := Connect}) ->
+                           case Connect(Sock, SSA) of
+                               ok ->
+                                   ok;
+                               {select, SelectInfo} ->
+                                   {error, {unexpected_select, SelectInfo}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+         #{desc => "get peername",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           case socket:peername(Sock) of
+                               {ok, SockAddr} ->
+                                   ?SEV_IPRINT("Peer Name: ~p", [SockAddr]),
+                                   ok;
+                                {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "await continue (send_req)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_req)
+                   end},
+         #{desc => "send req",
+           cmd  => fun(#{sock := Sock, send := Send}) ->
+                           Send(Sock, ?BASIC_REQ)
+                   end},
+         #{desc => "announce ready (send_req)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_req),
+                           ok
+                   end},
+         #{desc => "await continue (recv_rep)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_rep)
+                   end},
+         #{desc => "recv rep",
+           cmd  => fun(#{sock := Sock, recv := Recv}) ->
+                           case Recv(Sock) of
+                               {ok, ?BASIC_REP} ->
+                                   ok;
+                               {ok, UnexpData} ->
+                                   {error, {unexpected_data, UnexpData}};
+                               {error, _} = ERROR ->
+                                   %% At the moment there is no way to get
+                                   %% status or state for the socket...
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_rep)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_rep),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           State2 = maps:remove(sock,         State),
+                           State3 = maps:remove(connect_stag, State2),
+                           State4 = maps:remove(connect_sref, State3),
+                           {ok, State4}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_port => Port}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client := Pid, server_port := Port} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Port),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+
+
+         %% *** The actual test ***
+         #{desc => "order client to continue (async connect)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, async_connect),
+                           ok
+                   end},
+         #{desc => "await client ready (connect select)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, connect_select)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order server to continue (with accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, accept),
+                           ok
+                   end},
+         #{desc => "await client ready (select)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, select)
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, connect)
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, accept)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order server to recv test req (recv req)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, recv_req),
+                           ok
+                   end},
+         #{desc => "order client to send test req (send req)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send_req),
+                           ok
+                   end},
+         #{desc => "await client ready (send_req)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, send_req)
+                   end},
+         #{desc => "await server ready (recv_req)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, recv_req)
+                   end},
+         #{desc => "order client to recv test rep (send rep)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, recv_rep),
+                           ok
+                   end},
+         #{desc => "order server to send test rep (send rep)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, send_rep),
+                           ok
+                   end},
+         #{desc => "await server ready (send_rep)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, send_rep)
+                   end},
+         #{desc => "await client ready (recv_rep)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, recv_rep)
+                   end},
+
+
+         %% *** Termination ***
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client, State),
+                           {ok, State1}
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server, State),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    Server = ?SEV_START("server", ServerSeq, InitState),
+
+    i("start client evaluator"),
+    Client = ?SEV_START("client", ClientSeq, InitState),
+    i("await evaluator(s)"),
+
+    i("start tester evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive on an IPv4 UDP (dgram) socket using
+%% sendto and recvfrom. But we try to be async. That is, we use
+%% the 'nowait' value for the Timeout argument (and await the eventual
+%% select message). Note that we only do this for the recvfrom,
+%% since its much more difficult to "arrange" for sendto.
+%%
+api_a_sendto_and_recvfrom_udp4(suite) ->
+    [];
+api_a_sendto_and_recvfrom_udp4(doc) ->
+    [];
+api_a_sendto_and_recvfrom_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_a_sendto_and_recvfrom_udp4,
+           fun() ->
+                   Send = fun(Sock, Data, Dest) ->
+                                  socket:sendto(Sock, Data, Dest)
+                          end,
+                   Recv = fun(Sock) ->
+                                  socket:recvfrom(Sock, 0, nowait)
+                          end,
+                   InitState = #{domain => inet,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_a_send_and_recv_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive on an IPv6 UDP (dgram) socket using
+%% sendto and recvfrom. But we try to be async. That is, we use
+%% the 'nowait' value for the Timeout argument (and await the eventual
+%% select message). Note that we only do this for the recvfrom,
+%% since its much more difficult to "arrange" for sendto.
+%%
+api_a_sendto_and_recvfrom_udp6(suite) ->
+    [];
+api_a_sendto_and_recvfrom_udp6(doc) ->
+    [];
+api_a_sendto_and_recvfrom_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_a_sendto_and_recvfrom_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Send = fun(Sock, Data, Dest) ->
+                                  socket:sendto(Sock, Data, Dest)
+                          end,
+                   Recv = fun(Sock) ->
+                                  socket:recvfrom(Sock, 0, nowait)
+                          end,
+                   InitState = #{domain => inet6,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_a_send_and_recv_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive on an IPv4 UDP (dgram) socket using
+%% sendto and recvfrom. But we try to be async. That is, we use
+%% the 'nowait' value for the Timeout argument (and await the eventual
+%% select message). Note that we only do this for the recvmsg,
+%% since its much more difficult to "arrange" for sendmsg.
+%%
+api_a_sendmsg_and_recvmsg_udp4(suite) ->
+    [];
+api_a_sendmsg_and_recvmsg_udp4(doc) ->
+    [];
+api_a_sendmsg_and_recvmsg_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_a_sendmsg_and_recvmsg_udp4,
+           fun() ->
+                   Send = fun(Sock, Data, Dest) ->
+                                  MsgHdr = #{addr => Dest,
+                                             %% ctrl => CMsgHdrs,
+                                             iov  => [Data]},
+                                  socket:sendmsg(Sock, MsgHdr)
+                          end,
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock, nowait) of
+                                      {ok, #{addr  := Source,
+                                             iov   := [Data]}} ->
+                                          {ok, {Source, Data}};
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_a_send_and_recv_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive on an IPv6 UDP (dgram) socket using
+%% sendto and recvfrom. But we try to be async. That is, we use
+%% the 'nowait' value for the Timeout argument (and await the eventual
+%% select message). Note that we only do this for the recvmsg,
+%% since its much more difficult to "arrange" for sendmsg.
+%%
+api_a_sendmsg_and_recvmsg_udp6(suite) ->
+    [];
+api_a_sendmsg_and_recvmsg_udp6(doc) ->
+    [];
+api_a_sendmsg_and_recvmsg_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_a_sendmsg_and_recvmsg_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Send = fun(Sock, Data, Dest) ->
+                                  MsgHdr = #{addr => Dest,
+                                             %% ctrl => CMsgHdrs,
+                                             iov  => [Data]},
+                                  socket:sendmsg(Sock, MsgHdr)
+                          end,
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock, nowait) of
+                                      {ok, #{addr  := Source,
+                                             iov   := [Data]}} ->
+                                          {ok, {Source, Data}};
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet6,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_a_send_and_recv_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_send_and_recv_udp(InitState) ->
+    ServerSeq = 
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind socket (to local address)",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{port => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, local_sa := LSA, port := Port}) ->
+                           ServerSA = LSA#{port => Port},
+                           ?SEV_ANNOUNCE_READY(Tester, init, ServerSA),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "try recv request (with nowait, expect select)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, {select_info, Tag, RecvRef}} ->
+                                   ?SEV_IPRINT("expected select: "
+                                               "~n   Tag: ~p"
+                                               "~n   Ref: ~p", [Tag, RecvRef]),
+                                   {ok, State#{recv_stag => Tag,
+                                               recv_sref => RecvRef}};
+                               {ok, X} ->
+                                   {error, {unexpected_succes, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await select message",
+           cmd  => fun(#{sock := Sock, recv_sref := RecvRef}) ->
+                           receive
+                               {'$socket', Sock, select, RecvRef} ->
+                                   ok
+                           after 5000 ->
+                                   ?SEV_EPRINT("message queue: ~p", [mq()]),
+                                   {error, timeout}
+                           end
+                   end},
+         #{desc => "announce ready (select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, select),
+                           ok
+                   end},
+         #{desc => "now read the data (request)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {ok, {Src, ?BASIC_REQ}} ->
+                                   {ok, State#{req_src => Src}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv request)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_req),
+                           ok
+                   end},
+
+         #{desc => "await continue (send reply)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_reply)
+                   end},
+         #{desc => "send reply",
+           cmd  => fun(#{sock := Sock, req_src := Src, send := Send}) ->
+                           Send(Sock, ?BASIC_REP, Src)
+                   end},
+         #{desc => "announce ready (send)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   State2 = maps:remove(tester,    State),
+                                   State3 = maps:remove(recv_stag, State2),
+                                   State4 = maps:remove(recv_sref, State3),
+                                   State5 = maps:remove(req_src,   State4),
+                                   {ok, State5};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    ClientSeq = 
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, ServerSA} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester    => Tester, 
+                                       server_sa => ServerSA}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "open socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           Sock = sock_open(Domain, dgram, udp),
+                           SA   = sock_sockname(Sock),
+                           {ok, State#{sock => Sock, sa => SA}}
+                   end},
+         #{desc => "bind socket (to local address)",
+           cmd  => fun(#{sock := Sock, lsa := LSA}) ->
+                          case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (send request)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_req)
+                   end},
+         #{desc => "send request",
+           cmd  => fun(#{sock := Sock, server_sa := Server, send := Send}) ->
+                           Send(Sock, ?BASIC_REQ, Server)
+                   end},
+         #{desc => "announce ready (send request)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_req),
+                           ok
+                   end},
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "try recv reply (with nowait)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, {select_info, Tag, RecvRef}} ->
+                                   {ok, State#{recv_stag => Tag,
+                                               recv_sref => RecvRef}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await select message",
+           cmd  => fun(#{sock := Sock, recv_sref := RecvRef}) ->
+                           receive
+                               {'$socket', Sock, select, RecvRef} ->
+                                   ok
+                           end
+                   end},
+         #{desc => "announce ready (select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, select),
+                           ok
+                   end},
+         #{desc => "now read the data (reply)",
+           cmd  => fun(#{sock := Sock, recv := Recv}) ->
+                           case Recv(Sock) of
+                               {ok, {_Src, ?BASIC_REP}} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv reply)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_rep),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   State2 = maps:remove(tester,    State),
+                                   State3 = maps:remove(recv_stag, State2),
+                                   State4 = maps:remove(recv_sref, State3),
+                                   {ok, State4};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq = 
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, ServerSA} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client    := Pid, 
+                         server_sa := ServerSA} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, ServerSA),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+ 
+         %% The actual test
+         #{desc => "order server continue (recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await server ready (recv_select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, recv_select)
+                   end},
+
+         #{desc => "order client continue (send request)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, send_req),
+                           ok
+                   end},
+         #{desc => "await client ready (send request)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, send_req)
+                   end},
+         #{desc => "await server ready (select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, select)
+                   end},
+         #{desc => "await server ready (recv request)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, recv_req)
+                   end},
+
+         #{desc => "order client continue (recv)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await client ready (recv_select)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, recv_select)
+                   end},
+         #{desc => "order server continue (send reply)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, send_reply),
+                           ok
+                   end},
+         #{desc => "await server ready (send)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, send)
+                   end},
+         #{desc => "await client ready (select)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, select)
+                   end},
+         #{desc => "await client ready (recv reply)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, recv_rep)
+                   end},
+
+         %% Terminations
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(client, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    ServerInitState = InitState,
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator(s)"),
+    ClientInitState = InitState,
+    Client = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive using the "common" functions (send and recv)
+%% on an IPv4 TCP (stream) socket. But we try to be async. That is, we use
+%% the 'nowait' value for the Timeout argument (and await the eventual
+%% select message). Note that we only do this for the recv,
+%% since its much more difficult to "arrange" for send.
+%% We *also* test async for accept.
+api_a_send_and_recv_tcp4(suite) ->
+    [];
+api_a_send_and_recv_tcp4(doc) ->
+    [];
+api_a_send_and_recv_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_send_and_recv_tcp4,
+           fun() ->
+                   Send = fun(Sock, Data) ->
+                                  socket:send(Sock, Data)
+                          end,
+                   Recv = fun(Sock) ->
+                                  socket:recv(Sock, 0, nowait)
+                          end,
+                   InitState = #{domain => inet,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_a_send_and_recv_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive using the "common" functions (send and recv)
+%% on an IPv6 TCP (stream) socket. But we try to be async. That is, we use
+%% the 'nowait' value for the Timeout argument (and await the eventual
+%% select message). Note that we only do this for the recv,
+%% since its much more difficult to "arrange" for send.
+%% We *also* test async for accept.
+api_a_send_and_recv_tcp6(suite) ->
+    [];
+api_a_send_and_recv_tcp6(doc) ->
+    [];
+api_a_send_and_recv_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_send_and_recv_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Send = fun(Sock, Data) ->
+                                  socket:send(Sock, Data)
+                          end,
+                   Recv = fun(Sock) ->
+                                  socket:recv(Sock, 0, nowait)
+                          end,
+                   InitState = #{domain => inet6,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_a_send_and_recv_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive using the msg functions (sendmsg and recvmsg)
+%% on an IPv4 TCP (stream) socket. But we try to be async. That is, we use
+%% the 'nowait' value for the Timeout argument (and await the eventual
+%% select message). Note that we only do this for the recvmsg,
+%% since its much more difficult to "arrange" for sendmsg.
+%% We *also* test async for accept.
+api_a_sendmsg_and_recvmsg_tcp4(suite) ->
+    [];
+api_a_sendmsg_and_recvmsg_tcp4(doc) ->
+    [];
+api_a_sendmsg_and_recvmsg_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_sendmsg_and_recvmsg_tcp4,
+           fun() ->
+                   Send = fun(Sock, Data) ->
+                                  MsgHdr = #{iov => [Data]},
+                                  socket:sendmsg(Sock, MsgHdr)
+                          end,
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock, nowait) of
+                                      {ok, #{addr  := undefined,
+                                             iov   := [Data]}} ->
+                                          {ok, Data};
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+				      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_a_send_and_recv_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically send and receive using the msg functions (sendmsg and recvmsg)
+%% on an IPv6 TCP (stream) socket. But we try to be async. That is, we use
+%% the 'nowait' value for the Timeout argument (and await the eventual
+%% select message). Note that we only do this for the recvmsg,
+%% since its much more difficult to "arrange" for sendmsg.
+%% We *also* test async for accept.
+api_a_sendmsg_and_recvmsg_tcp6(suite) ->
+    [];
+api_a_sendmsg_and_recvmsg_tcp6(doc) ->
+    [];
+api_a_sendmsg_and_recvmsg_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_sendmsg_and_recvmsg_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Send = fun(Sock, Data) ->
+                                  MsgHdr = #{iov => [Data]},
+                                  socket:sendmsg(Sock, MsgHdr)
+                          end,
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock, nowait) of
+                                      {ok, #{addr  := undefined,
+                                             iov   := [Data]}} ->
+                                          {ok, Data};
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+				      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet6,
+                                 send   => Send,
+                                 recv   => Recv},
+                   ok = api_a_send_and_recv_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_send_and_recv_tcp(InitState) ->
+    process_flag(trap_exit, true),
+    ServerSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, lsa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, lport := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "await connection (nowait)",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock, nowait) of
+                               {select, {select_info, Tag, Ref}} ->
+                                   ?SEV_IPRINT("accept select: "
+                                               "~n   Tag: ~p"
+                                               "~n   Ref: ~p", [Tag, Ref]),
+                                   {ok, State#{accept_stag => Tag,
+                                               accept_sref => Ref}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept_select),
+                           ok
+                   end},
+         #{desc => "await select message",
+           cmd  => fun(#{lsock := Sock, accept_sref := Ref}) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   ok
+                           end
+                   end},
+         #{desc => "announce ready (select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, select),
+                           ok
+                   end},
+         #{desc => "await connection (again)",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock, nowait) of
+                               {ok, Sock} ->
+                                   ?SEV_IPRINT("accepted: "
+                                               "~n   Sock: ~p", [Sock]),
+                                   {ok, State#{csock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv request)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_req)
+                   end},
+         #{desc => "try recv request (with nowait, expect select)",
+           cmd  => fun(#{csock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, {select_info, Tag, Ref}} ->
+                                   ?SEV_IPRINT("recv select: "
+                                               "~n   Tag: ~p"
+                                               "~n   Ref: ~p", [Tag, Ref]),
+                                   {ok, State#{recv_stag => Tag,
+                                               recv_sref => Ref}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await select message",
+           cmd  => fun(#{csock := Sock, recv_sref := RecvRef}) ->
+                           receive
+                               {'$socket', Sock, select, RecvRef} ->
+                                   ok
+                           end
+                   end},
+         #{desc => "announce ready (select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, select),
+                           ok
+                   end},
+         #{desc => "now read the data (request)",
+           cmd  => fun(#{csock := Sock, recv := Recv} = _State) ->
+                           case Recv(Sock) of
+                               {ok, ?BASIC_REQ} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv request)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_req),
+                           ok
+                   end},
+
+         #{desc => "await continue (send reply)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_rep)
+                   end},
+         #{desc => "send reply",
+           cmd  => fun(#{csock := Sock, send := Send}) ->
+                           Send(Sock, ?BASIC_REP)
+                   end},
+         #{desc => "announce ready (send reply)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_rep),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close connection socket",
+           cmd  => fun(#{csock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{lsock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    ClientSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           {Tester, Port} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_port => Port}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** The init part ***
+         #{desc => "which server (local) address",
+           cmd  => fun(#{domain := Domain, server_port := Port} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = LSA#{port => Port},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect)
+                   end},
+         #{desc => "connect to server",
+           cmd  => fun(#{sock := Sock, server_sa := SSA}) ->
+                           socket:connect(Sock, SSA)
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+
+         #{desc => "await continue (send request)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_req)
+                   end},
+         #{desc => "send request (to server)",
+           cmd  => fun(#{sock := Sock, send := Send}) ->
+                           ok = Send(Sock, ?BASIC_REQ)
+                   end},
+         #{desc => "announce ready (send request)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_req),
+                           ok
+                   end},
+
+         #{desc => "try recv reply (with nowait, expect select)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, {select_info, Tag, Ref}} ->
+                                   ?SEV_IPRINT("recv select: "
+                                               "~n   Tag: ~p"
+                                               "~n   Ref: ~p", [Tag, Ref]),
+                                   {ok, State#{recv_stag => Tag,
+                                               recv_sref => Ref}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await select message",
+           cmd  => fun(#{sock := Sock, recv_sref := RecvRef}) ->
+                           receive
+                               {'$socket', Sock, select, RecvRef} ->
+                                   ok
+                           end
+                   end},
+         #{desc => "announce ready (select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, select),
+                           ok
+                   end},
+         #{desc => "now read the data (reply)",
+           cmd  => fun(#{sock := Sock, recv := Recv}) ->
+                           {ok, ?BASIC_REP} = Recv(Sock),
+                           ok
+                   end},
+         #{desc => "announce ready (recv reply)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_rep),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_port => Port}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client := Pid, server_port := Port} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Port),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "order server to continue (with accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, accept),
+                           ok
+                   end},
+         #{desc => "await server ready (accept select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, accept_select)
+                   end},
+         #{desc => "order client to continue (with connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect),
+                           ok
+                   end},
+         #{desc => "await server ready (select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, select)
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, accept)
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, client, connect)
+                   end},
+
+         #{desc => "order server to continue (recv request)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv_req),
+                           ok
+                   end},
+         #{desc => "await server ready (recv select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, recv_select)
+                   end},
+         #{desc => "order client to continue (send request)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, send_req),
+                           ok
+                   end},
+         #{desc => "await client ready (send request)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, send_req)
+                   end},
+         #{desc => "await server ready (select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, select)
+                   end},
+         #{desc => "await server ready (recv request)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, recv_req)
+                   end},
+
+         #{desc => "order client to continue (recv reply)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv_rep),
+                           ok
+                   end},
+         #{desc => "await client ready (recv select)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, client, recv_select)
+                   end},
+         #{desc => "order server to continue (send reply)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, send_rep),
+                           ok
+                   end},
+         #{desc => "await server ready (send reply)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, send_rep)
+                   end},
+         #{desc => "await client ready (select)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, client, select)
+                   end},
+         #{desc => "await client ready (reply recv)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, recv_rep)
+                   end},
+
+
+         %% *** Termination ***
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client, State),
+                           {ok, State1}
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server, State),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    Server = ?SEV_START("server", ServerSeq, InitState),
+
+    i("start client evaluator"),
+    Client = ?SEV_START("client", ClientSeq, InitState),
+
+    i("start tester evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to recvfrom,
+%% wait some time and then cancel. IPv4
+%%
+api_a_recvfrom_cancel_udp4(suite) ->
+    [];
+api_a_recvfrom_cancel_udp4(doc) ->
+    [];
+api_a_recvfrom_cancel_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_recvfrom_cancel_udp4,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  case socket:recvfrom(Sock, 0, nowait) of
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet,
+                                 recv   => Recv},
+                   ok = api_a_recv_cancel_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to recvfrom,
+%% wait some time and then cancel. IPv6
+%%
+api_a_recvfrom_cancel_udp6(suite) ->
+    [];
+api_a_recvfrom_cancel_udp6(doc) ->
+    [];
+api_a_recvfrom_cancel_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_recvfrom_cancel_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  case socket:recvfrom(Sock, 0, nowait) of
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet6,
+                                 recv   => Recv},
+                   ok = api_a_recv_cancel_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to recvmsg,
+%% wait some time and then cancel. IPv4
+%%
+api_a_recvmsg_cancel_udp4(suite) ->
+    [];
+api_a_recvmsg_cancel_udp4(doc) ->
+    [];
+api_a_recvmsg_cancel_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_recvmsg_cancel_udp4,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock, nowait) of
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet,
+                                 recv   => Recv},
+                   ok = api_a_recv_cancel_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to recvmsg,
+%% wait some time and then cancel. IPv6
+%%
+api_a_recvmsg_cancel_udp6(suite) ->
+    [];
+api_a_recvmsg_cancel_udp6(doc) ->
+    [];
+api_a_recvmsg_cancel_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_recvmsg_cancel_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock, nowait) of
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet6,
+                                 recv   => Recv},
+                   ok = api_a_recv_cancel_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_recv_cancel_udp(InitState) ->
+    ServerSeq = 
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind socket (to local address)",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{port => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, local_sa := LSA, port := Port}) ->
+                           ServerSA = LSA#{port => Port},
+                           ?SEV_ANNOUNCE_READY(Tester, init, ServerSA),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "try recv request (with nowait, expect select)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, SelectInfo} ->
+                                   {ok, State#{recv_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await select message (without success)",
+           cmd  => fun(#{sock := Sock}) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}}
+                           after 5000 ->
+                                   ok
+                           end
+                   end},
+         #{desc => "announce ready (no select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, no_select),
+                           ok
+                   end},
+         #{desc => "await continue (cancel)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, cancel)
+                   end},
+         #{desc => "cancel",
+           cmd  => fun(#{sock := Sock, recv_select_info := SelectInfo}) ->
+                           ok = socket:cancel(Sock, SelectInfo)
+                   end},
+         #{desc => "announce ready (cancel)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, cancel),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   State2 = maps:remove(tester,    State),
+                                   State3 = maps:remove(recv_stag, State2),
+                                   State4 = maps:remove(recv_sref, State3),
+                                   State5 = maps:remove(req_src,   State4),
+                                   {ok, State5};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq = 
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, ServerSA} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+
+         %% The actual test
+         #{desc => "order server continue (recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await server ready (recv select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, recv_select)
+                   end},
+         #{desc => "await server ready (no select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, no_select)
+                   end},
+         #{desc => "order server continue (cancel)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, cancel),
+                           ok
+                   end},
+         #{desc => "await server ready (cancel)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, cancel)
+                   end},
+
+         %% Terminations
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    ServerInitState = InitState,
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server => Server#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server, Tester]).
+
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to accept,
+%% wait some time and then cancel. IPv4
+%%
+api_a_accept_cancel_tcp4(suite) ->
+    [];
+api_a_accept_cancel_tcp4(doc) ->
+    [];
+api_a_accept_cancel_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_accept_cancel_tcp4,
+           fun() ->
+                   Accept = fun(Sock) ->
+                                    case socket:accept(Sock, nowait) of
+                                        {ok, _} = OK ->
+                                            OK;
+                                        {select, _} = SELECT ->
+                                            SELECT;
+                                        {error, _} = ERROR ->
+                                            ERROR
+                                    end
+                            end,
+                   InitState = #{domain => inet,
+                                 accept => Accept},
+                   ok = api_a_accept_cancel_tcp(InitState)
+           end).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to accept,
+%% wait some time and then cancel. IPv6
+%%
+api_a_accept_cancel_tcp6(suite) ->
+    [];
+api_a_accept_cancel_tcp6(doc) ->
+    [];
+api_a_accept_cancel_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_accept_cancel_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Accept = fun(Sock) ->
+                                    case socket:accept(Sock, nowait) of
+                                        {ok, _} = OK ->
+                                            OK;
+                                        {select, _} = SELECT ->
+                                            SELECT;
+                                        {error, _} = ERROR ->
+                                            ERROR
+                                    end
+                            end,
+                   InitState = #{domain => inet6,
+                                 accept => Accept},
+                   ok = api_a_accept_cancel_tcp(InitState)
+           end).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_accept_cancel_tcp(InitState) ->
+    process_flag(trap_exit, true),
+    ServerSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, lsa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, lport := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "await connection (nowait)",
+           cmd  => fun(#{lsock := LSock, accept := Accept} = State) ->
+                           case Accept(LSock) of
+                               {select, {select_info, T, R} = SelectInfo} ->
+                                   ?SEV_IPRINT("accept select: "
+                                               "~n   T: ~p"
+                                               "~n   R: ~p", [T, R]),
+                                   {ok, State#{accept_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept_select),
+                           ok
+                   end},
+         #{desc => "await select message (without success)",
+           cmd  => fun(#{lsock := Sock}) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}}
+                           after 5000 ->
+                                   ok
+                           end
+                   end},
+         #{desc => "announce ready (no select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, no_select),
+                           ok
+                   end},
+         #{desc => "await continue (cancel)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, cancel)
+                   end},
+         #{desc => "cancel",
+           cmd  => fun(#{lsock := Sock, accept_select_info := SelectInfo}) ->
+                           ok = socket:cancel(Sock, SelectInfo)
+                   end},
+         #{desc => "announce ready (cancel)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, cancel),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{lsock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_port => Port}}
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "order server to continue (with accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, accept),
+                           ok
+                   end},
+         #{desc => "await server ready (accept select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, accept_select)
+                   end},
+         #{desc => "await server ready (no select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, no_select)
+                   end},
+         #{desc => "order server to continue (cancel)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, cancel),
+                           ok
+                   end},
+         #{desc => "await server ready (cancel)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, cancel)
+                   end},
+
+         %% *** Termination ***
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server, State),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    Server = ?SEV_START("server", ServerSeq, InitState),
+
+    i("start tester evaluator"),
+    TesterInitState = #{server => Server#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, Tester]).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to recv,
+%% wait some time and then cancel. IPv4
+%%
+api_a_recv_cancel_tcp4(suite) ->
+    [];
+api_a_recv_cancel_tcp4(doc) ->
+    [];
+api_a_recv_cancel_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_recv_cancel_tcp4,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  socket:recv(Sock, 0, nowait)
+                          end,
+                   InitState = #{domain => inet,
+                                 recv   => Recv},
+                   ok = api_a_recv_cancel_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to recv,
+%% wait some time and then cancel. IPv6
+%%
+api_a_recv_cancel_tcp6(suite) ->
+    [];
+api_a_recv_cancel_tcp6(doc) ->
+    [];
+api_a_recv_cancel_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_recv_cancel_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  socket:recv(Sock, 0, nowait)
+                          end,
+                   InitState = #{domain => inet6,
+                                 recv   => Recv},
+                   ok = api_a_recv_cancel_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to recvmsg,
+%% wait some time and then cancel. IPv4
+%%
+api_a_recvmsg_cancel_tcp4(suite) ->
+    [];
+api_a_recvmsg_cancel_tcp4(doc) ->
+    [];
+api_a_recvmsg_cancel_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_recvmsg_cancel_tcp4,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  socket:recvmsg(Sock, nowait)
+                          end,
+                   InitState = #{domain => inet,
+                                 recv   => Recv},
+                   ok = api_a_recv_cancel_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to recvmsg,
+%% wait some time and then cancel. IPv6
+%%
+api_a_recvmsg_cancel_tcp6(suite) ->
+    [];
+api_a_recvmsg_cancel_tcp6(doc) ->
+    [];
+api_a_recvmsg_cancel_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_a_recvmsg_cancel_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  socket:recvmsg(Sock, nowait)
+                          end,
+                   InitState = #{domain => inet6,
+                                 recv   => Recv},
+                   ok = api_a_recv_cancel_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_recv_cancel_tcp(InitState) ->
+    process_flag(trap_exit, true),
+    ServerSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, lsa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, lport := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "await connection (nowait)",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, CSock} ->
+                                   {ok, State#{csock => CSock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+
+         #{desc => "await continue (nowait recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "try recv request (with nowait, expect select)",
+           cmd  => fun(#{csock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, {select_info, T, R} = SelectInfo} ->
+                                   ?SEV_IPRINT("recv select: "
+                                               "~n   Tag: ~p"
+                                               "~n   Ref: ~p", [T, R]),
+                                   {ok, State#{recv_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await select message",
+           cmd  => fun(#{csock := Sock}) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}}
+                           after 5000 ->
+                                   ok
+                           end
+                   end},
+         #{desc => "announce ready (no select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, no_select),
+                           ok
+                   end},
+         #{desc => "await continue (cancel)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, cancel)
+                   end},
+         #{desc => "cancel",
+           cmd  => fun(#{csock := Sock, recv_select_info := SelectInfo}) ->
+                           ok = socket:cancel(Sock, SelectInfo)
+                   end},
+         #{desc => "announce ready (cancel)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, cancel),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close connection socket",
+           cmd  => fun(#{csock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{lsock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    ClientSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           {Tester, Port} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_port => Port}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** The init part ***
+         #{desc => "which server (local) address",
+           cmd  => fun(#{domain := Domain, server_port := Port} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = LSA#{port => Port},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect)
+                   end},
+         #{desc => "connect to server",
+           cmd  => fun(#{sock := Sock, server_sa := SSA}) ->
+                           socket:connect(Sock, SSA)
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_port => Port}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client := Pid, server_port := Port} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Port),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "order server to continue (with accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, accept),
+                           ok
+                   end},
+         #{desc => "order client to continue (connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect),
+                           ok
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, client, connect)
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, accept)
+                   end},
+
+         #{desc => "order server to continue (recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await server ready (recv select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, recv_select)
+                   end},
+         #{desc => "await server ready (no select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, no_select)
+                   end},
+         #{desc => "order server to continue (send request)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, cancel),
+                           ok
+                   end},
+         #{desc => "await server ready (cancel)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, server, cancel)
+                   end},
+
+         %% *** Termination ***
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client, State),
+                           {ok, State1}
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server, State),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    Server = ?SEV_START("server", ServerSeq, InitState),
+
+    i("start client evaluator"),
+    Client = ?SEV_START("client", ClientSeq, InitState),
+
+    i("start tester evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to recvfrom
+%% (from *several* processes), wait some time and then cancel.
+%% This should result in abort messages to the 'other' processes. IPv4
+%%
+api_a_mrecvfrom_cancel_udp4(suite) ->
+    [];
+api_a_mrecvfrom_cancel_udp4(doc) ->
+    [];
+api_a_mrecvfrom_cancel_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_mrecvfrom_cancel_udp4,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  case socket:recvfrom(Sock, 0, nowait) of
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet,
+                                 recv   => Recv},
+                   ok = api_a_mrecv_cancel_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to recvfrom
+%% (from *several* processes), wait some time and then cancel.
+%% This should result in abort messages to the 'other' processes. IPv6
+%%
+api_a_mrecvfrom_cancel_udp6(suite) ->
+    [];
+api_a_mrecvfrom_cancel_udp6(doc) ->
+    [];
+api_a_mrecvfrom_cancel_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_mrecvfrom_cancel_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  case socket:recvfrom(Sock, 0, nowait) of
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet6,
+                                 recv   => Recv},
+                   ok = api_a_mrecv_cancel_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to recvmsg
+%% (from *several* processes), wait some time and then cancel.
+%% This should result in abort messages to the 'other' processes. IPv4
+%%
+api_a_mrecvmsg_cancel_udp4(suite) ->
+    [];
+api_a_mrecvmsg_cancel_udp4(doc) ->
+    [];
+api_a_mrecvmsg_cancel_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_mrecvmsg_cancel_udp4,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock, nowait) of
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet,
+                                 recv   => Recv},
+                   ok = api_a_mrecv_cancel_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to recvmsg
+%% (from *several* processes), wait some time and then cancel.
+%% This should result in abort messages to the 'other' processes. IPv6
+%%
+api_a_mrecvmsg_cancel_udp6(suite) ->
+    [];
+api_a_mrecvmsg_cancel_udp6(doc) ->
+    [];
+api_a_mrecvmsg_cancel_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_mrecvmsg_cancel_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  case socket:recvmsg(Sock, nowait) of
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {select, _} = SELECT ->
+                                          SELECT;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet6,
+                                 recv   => Recv},
+                   ok = api_a_mrecv_cancel_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_mrecv_cancel_udp(InitState) ->
+    ServerSeq = 
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind socket (to local address)",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{port => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, sock := Sock}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Sock),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "try recv request (with nowait, expect select)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, SelectInfo} ->
+                                   {ok, State#{recv_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await abort message",
+           cmd  => fun(#{sock             := Sock,
+                         recv_select_info := {select_info, _, Ref}} = State) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}};
+                               {'$socket', Sock, abort, {Ref, closed}} ->
+                                   {ok, maps:remove(sock, State)}
+                           after 5000 ->
+                                   ?SEV_EPRINT("message queue: ~p", [mq()]),
+                                   {error, timeout}
+                           end
+                   end},
+         #{desc => "announce ready (abort)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, abort),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   State2 = maps:remove(tester,    State),
+                                   State3 = maps:remove(recv_stag, State2),
+                                   State4 = maps:remove(recv_sref, State3),
+                                   State5 = maps:remove(req_src,   State4),
+                                   {ok, State5};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    AltServerSeq = 
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, Sock} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, sock => Sock}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "try recv request (with nowait, expect select)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, SelectInfo} ->
+                                   {ok, State#{recv_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await abort message",
+           cmd  => fun(#{sock             := Sock,
+                         recv_select_info := {select_info, _, Ref}} = State) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}};
+                               {'$socket', Sock, abort, {Ref, closed}} ->
+                                   {ok, maps:remove(sock, State)}
+                           after 5000 ->
+                                   ?SEV_EPRINT("message queue: ~p", [mq()]),
+                                   {error, timeout}
+                           end
+                   end},
+         #{desc => "announce ready (abort)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, abort),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   ?SEV_IPRINT("terminating"),
+                                   State1 = maps:remove(recv_select_info, State),
+                                   State2 = maps:remove(tester,           State1),
+                                   State3 = maps:remove(sock,             State2),
+                                   {ok, State3};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+
+    TesterSeq = 
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor alt-server 1",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor alt-server 2",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, Sock} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{sock => Sock}}
+                   end},
+
+         %% Start the alt-server 1
+         #{desc => "order alt-server 1 start",
+           cmd  => fun(#{alt_server1 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await alt-server 1 ready (init)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, alt_server1, init)
+                   end},
+
+         %% Start the alt-server 2
+         #{desc => "order alt-server 2 start",
+           cmd  => fun(#{alt_server2 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await alt-server 2 ready (init)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, alt_server2, init)
+                   end},
+
+
+         %% The actual test
+         #{desc => "order server continue (recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await server ready (recv select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, recv_select)
+                   end},
+
+         #{desc => "order alt-server 1 continue (recv)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await alt-server 1 ready (recv select)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server1, recv_select)
+                   end},
+
+         #{desc => "order alt-server 2 continue (recv)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await alt-server 2 ready (recv select)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server2, recv_select)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "close the socket",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           socket:close(Sock)
+                   end},
+
+         #{desc => "await server ready (abort)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, abort)
+                   end},
+         #{desc => "await alt-server 1 ready (abort)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server1, abort)
+                   end},
+         #{desc => "await alt-server 2 ready (abort)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server2, abort)
+                   end},
+
+         %% Terminations
+         #{desc => "order alt-server 2 to terminate",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await alt-server 2 termination",
+           cmd  => fun(#{alt_server2 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(alt_server2, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "order alt-server 1 to terminate",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await alt-server 1 termination",
+           cmd  => fun(#{alt_server1 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(alt_server1, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    Server = ?SEV_START("server", ServerSeq, InitState),
+
+    i("start alt-server 1 evaluator"),
+    AltServer1 = ?SEV_START("alt_server1", AltServerSeq, InitState),
+
+    i("start alt-server 2 evaluator"),
+    AltServer2 = ?SEV_START("alt_server2", AltServerSeq, InitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server      => Server#ev.pid,
+                        alt_server1 => AltServer1#ev.pid,
+                        alt_server2 => AltServer2#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, AltServer1, AltServer2, Tester]).
+
+
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to accept
+%% (from *several* processes), wait some time and then cancel,
+%% This should result in abort messages to the 'other' processes. IPv4
+%%
+api_a_maccept_cancel_tcp4(suite) ->
+    [];
+api_a_maccept_cancel_tcp4(doc) ->
+    [];
+api_a_maccept_cancel_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_maccept_cancel_tcp4,
+           fun() ->
+                   Accept = fun(Sock) ->
+                                    case socket:accept(Sock, nowait) of
+                                        {ok, _} = OK ->
+                                            OK;
+                                        {select, _} = SELECT ->
+                                            SELECT;
+                                        {error, _} = ERROR ->
+                                            ERROR
+                                    end
+                            end,
+                   InitState = #{domain => inet,
+                                 accept => Accept},
+                   ok = api_a_maccept_cancel_tcp(InitState)
+           end).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to accept
+%% (from *several* processes), wait some time and then cancel,
+%% This should result in abort messages to the 'other' processes. IPv6
+%%
+api_a_maccept_cancel_tcp6(suite) ->
+    [];
+api_a_maccept_cancel_tcp6(doc) ->
+    [];
+api_a_maccept_cancel_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_maccept_cancel_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Accept = fun(Sock) ->
+                                    case socket:accept(Sock, nowait) of
+                                        {ok, _} = OK ->
+                                            OK;
+                                        {select, _} = SELECT ->
+                                            SELECT;
+                                        {error, _} = ERROR ->
+                                            ERROR
+                                    end
+                            end,
+                   InitState = #{domain => inet6,
+                                 accept => Accept},
+                   ok = api_a_maccept_cancel_tcp(InitState)
+           end).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_maccept_cancel_tcp(InitState) ->
+    process_flag(trap_exit, true),
+    ServerSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, lsa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, lsock := Sock}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Sock),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "await connection (nowait)",
+           cmd  => fun(#{lsock := LSock, accept := Accept} = State) ->
+                           case Accept(LSock) of
+                               {select, {select_info, T, R} = SelectInfo} ->
+                                   ?SEV_IPRINT("accept select: "
+                                               "~n   T: ~p"
+                                               "~n   R: ~p", [T, R]),
+                                   {ok, State#{accept_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept_select),
+                           ok
+                   end},
+         #{desc => "await select message (without success)",
+           cmd  => fun(#{lsock              := Sock,
+                         accept_select_info := {select_info, _, Ref}} = State) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}};
+                               {'$socket', Sock, abort, {Ref, closed}} ->
+                                   {ok, maps:remove(lsock, State)}
+                           after 5000 ->
+                                   ?SEV_EPRINT("message queue: ~p", [mq()]),
+                                   {error, timeout}
+                           end
+                   end},
+         #{desc => "announce ready (abort)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, abort),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    AltServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, Sock} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, lsock => Sock}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "try accept request (with nowait, expect select)",
+           cmd  => fun(#{lsock := Sock, accept := Accept} = State) ->
+                           case Accept(Sock) of
+                               {select, SelectInfo} ->
+                                   {ok, State#{accept_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept_select),
+                           ok
+                   end},
+         #{desc => "await abort message",
+           cmd  => fun(#{lsock              := Sock,
+                         accept_select_info := {select_info, _, Ref}} = State) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}};
+                               {'$socket', Sock, abort, {Ref, closed}} ->
+                                   {ok, maps:remove(sock, State)}
+                           after 5000 ->
+                                   ?SEV_EPRINT("message queue: ~p", [mq()]),
+                                   {error, timeout}
+                           end
+                   end},
+         #{desc => "announce ready (abort)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, abort),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   ?SEV_IPRINT("terminating"),
+                                   State1 = maps:remove(tester,             State),
+                                   State2 = maps:remove(accept_select_info, State1),
+                                   State3 = maps:remove(lsock,              State2),
+                                   {ok, State3};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor alt-server 1",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor alt-server 2",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, Sock} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{sock => Sock}}
+                   end},
+
+         %% Start the alt-server 1
+         #{desc => "order alt-server 1 start",
+           cmd  => fun(#{alt_server1 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await alt-server 1 ready (init)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, alt_server1, init)
+                   end},
+
+         %% Start the alt-server 2
+         #{desc => "order alt-server 2 start",
+           cmd  => fun(#{alt_server2 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await alt-server 2 ready (init)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, alt_server2, init)
+                   end},
+
+
+         %% *** The actual test ***
+         #{desc => "order server continue (accept)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         #{desc => "await server ready (accept select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, accept_select)
+                   end},
+
+         #{desc => "order alt-server 1 continue (accept)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         #{desc => "await alt-server 1 ready (accept select)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server1, accept_select)
+                   end},
+
+         #{desc => "order alt-server 2 continue (accept)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         #{desc => "await alt-server 2 ready (accept select)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server2, accept_select)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "close the socket",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           socket:close(Sock)
+                   end},
+
+         #{desc => "await server ready (abort)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, abort)
+                   end},
+         #{desc => "await alt-server 1 ready (abort)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server1, abort)
+                   end},
+         #{desc => "await alt-server 2 ready (abort)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server2, abort)
+                   end},
+
+
+         %% *** Termination ***
+         #{desc => "order alt-server 2 to terminate",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await alt-server 2 termination",
+           cmd  => fun(#{alt_server2 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(alt_server2, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "order alt-server 1 to terminate",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await alt-server 1 termination",
+           cmd  => fun(#{alt_server1 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(alt_server1, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server, State),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    Server = ?SEV_START("server", ServerSeq, InitState),
+
+    i("start alt-server 1 evaluator"),
+    AltServer1 = ?SEV_START("alt_server1", AltServerSeq, InitState),
+
+    i("start alt-server 2 evaluator"),
+    AltServer2 = ?SEV_START("alt_server2", AltServerSeq, InitState),
+
+    i("start tester evaluator"),
+    TesterInitState = #{server      => Server#ev.pid,
+                        alt_server1 => AltServer1#ev.pid,
+                        alt_server2 => AltServer2#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, AltServer1, AltServer2, Tester]).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to recv
+%% (from *several* processes), wait some time and then cancel,
+%% This should result in abort messages to the 'other' processes. IPv4
+%%
+api_a_mrecv_cancel_tcp4(suite) ->
+    [];
+api_a_mrecv_cancel_tcp4(doc) ->
+    [];
+api_a_mrecv_cancel_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_mrecv_cancel_tcp4,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  socket:recv(Sock, 0, nowait)
+                          end,
+                   InitState = #{domain => inet,
+                                 recv   => Recv},
+                   ok = api_a_mrecv_cancel_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to recv
+%% (from *several* processes), wait some time and then cancel,
+%% This should result in abort messages to the 'other' processes. IPv6
+%%
+api_a_mrecv_cancel_tcp6(suite) ->
+    [];
+api_a_mrecv_cancel_tcp6(doc) ->
+    [];
+api_a_mrecv_cancel_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_mrecv_cancel_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  socket:recv(Sock, 0, nowait)
+                          end,
+                   InitState = #{domain => inet6,
+                                 recv   => Recv},
+                   ok = api_a_mrecv_cancel_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to recvmsg
+%% (from *several* processes), wait some time and then cancel,
+%% This should result in abort messages to the 'other' processes. IPv4
+%%
+api_a_mrecvmsg_cancel_tcp4(suite) ->
+    [];
+api_a_mrecvmsg_cancel_tcp4(doc) ->
+    [];
+api_a_mrecvmsg_cancel_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_mrecvmsg_cancel_tcp4,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  socket:recvmsg(Sock, nowait)
+                          end,
+                   InitState = #{domain => inet,
+                                 recv   => Recv},
+                   ok = api_a_mrecv_cancel_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make multiple async (Timeout = nowait) call(s) to recvmsg
+%% (from *several* processes), wait some time and then cancel,
+%% This should result in abort messages to the 'other' processes. IPv6
+%%
+api_a_mrecvmsg_cancel_tcp6(suite) ->
+    [];
+api_a_mrecvmsg_cancel_tcp6(doc) ->
+    [];
+api_a_mrecvmsg_cancel_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_a_mrecvmsg_cancel_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  socket:recvmsg(Sock, nowait)
+                          end,
+                   InitState = #{domain => inet6,
+                                 recv   => Recv},
+                   ok = api_a_mrecv_cancel_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_mrecv_cancel_tcp(InitState) ->
+    process_flag(trap_exit, true),
+    ServerSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, lsa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, lport := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "await connection (nowait)",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, CSock} ->
+                                   {ok, State#{csock => CSock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester, csock := Sock}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept, Sock),
+                           ok
+                   end},
+
+         #{desc => "await continue (nowait recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "try recv request (with nowait, expect select)",
+           cmd  => fun(#{csock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, {select_info, T, R} = SelectInfo} ->
+                                   ?SEV_IPRINT("recv select: "
+                                               "~n   Tag: ~p"
+                                               "~n   Ref: ~p", [T, R]),
+                                   {ok, State#{recv_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await select message",
+           cmd  => fun(#{csock            := Sock,
+                         recv_select_info := {select_info, _, Ref}} = State) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}};
+                               {'$socket', Sock, abort, {Ref, closed}} ->
+                                   {ok, maps:remove(sock, State)}
+                           after 5000 ->
+                                   ok
+                           end
+                   end},
+         #{desc => "announce ready (abort)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, abort),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{lsock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    AltServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, Sock} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, sock => Sock}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "try recv request (with nowait, expect select)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {select, SelectInfo} ->
+                                   {ok, State#{recv_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await abort message",
+           cmd  => fun(#{sock             := Sock,
+                         recv_select_info := {select_info, _, Ref}} = State) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}};
+                               {'$socket', Sock, abort, {Ref, closed}} ->
+                                   {ok, maps:remove(sock, State)}
+                           after 5000 ->
+                                   ?SEV_EPRINT("message queue: ~p", [mq()]),
+                                   {error, timeout}
+                           end
+                   end},
+         #{desc => "announce ready (abort)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, abort),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   ?SEV_IPRINT("terminating"),
+                                   State1 = maps:remove(recv_select_info, State),
+                                   State2 = maps:remove(tester,           State1),
+                                   State3 = maps:remove(sock,             State2),
+                                   {ok, State3};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           {Tester, Port} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_port => Port}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** The init part ***
+         #{desc => "which server (local) address",
+           cmd  => fun(#{domain := Domain, server_port := Port} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = LSA#{port => Port},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect)
+                   end},
+         #{desc => "connect to server",
+           cmd  => fun(#{sock := Sock, server_sa := SSA}) ->
+                           socket:connect(Sock, SSA)
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor alt-server 1",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor alt-server 2",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_port => Port}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client := Pid, server_port := Port} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Port),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+
+         #{desc => "order server to continue (with accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, accept),
+                           ok
+                   end},
+         #{desc => "order client to continue (connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect),
+                           ok
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, client, connect)
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, Sock} = ?SEV_AWAIT_READY(Pid, server, accept),
+                           {ok, State#{sock => Sock}}
+                   end},
+
+         %% Start the alt server 1
+         #{desc => "order alt-server 1 start",
+           cmd  => fun(#{alt_server1 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await alt-server 1 ready (init)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server1, init)
+                   end},
+
+         %% Start the alt server 2
+         #{desc => "order alt-server 2 start",
+           cmd  => fun(#{alt_server2 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await alt-server 2 ready (init)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server2, init)
+                   end},
+
+
+         %% *** The actual test ***
+         #{desc => "order server continue (recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await server ready (recv select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, recv_select)
+                   end},
+
+         #{desc => "order alt-server 1 continue (recv)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await alt-server 1 ready (recv select)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server1, recv_select)
+                   end},
+
+         #{desc => "order alt-server 2 continue (recv)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await alt-server 2 ready (recv select)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server2, recv_select)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "close the socket",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           socket:close(Sock)
+                   end},
+
+         #{desc => "await server ready (abort)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, abort)
+                   end},
+         #{desc => "await alt-server 1 ready (abort)",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server1, abort)
+                   end},
+         #{desc => "await alt-server 2 ready (abort)",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, alt_server2, abort)
+                   end},
+
+         %% Terminations
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client, State),
+                           {ok, State1}
+                   end},
+
+         #{desc => "order alt-server 2 to terminate",
+           cmd  => fun(#{alt_server2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await alt-server 2 termination",
+           cmd  => fun(#{alt_server2 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(alt_server2, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "order alt-server 1 to terminate",
+           cmd  => fun(#{alt_server1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await alt-server 1 termination",
+           cmd  => fun(#{alt_server1 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(alt_server1, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    Server = ?SEV_START("server", ServerSeq, InitState),
+
+    i("start alt-server 1 evaluator"),
+    AltServer1 = ?SEV_START("alt_server1", AltServerSeq, InitState),
+
+    i("start alt-server 2 evaluator"),
+    AltServer2 = ?SEV_START("alt_server2", AltServerSeq, InitState),
+
+    i("start client evaluator"),
+    Client = ?SEV_START("client", ClientSeq, InitState),
+
+    i("start tester evaluator"),
+    TesterInitState = #{server      => Server#ev.pid,
+                        alt_server1 => AltServer1#ev.pid,
+                        alt_server2 => AltServer2#ev.pid,
+                        client      => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, AltServer1, AltServer2, Client, Tester]).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%                                                                     %%
+%%                           API OPTIONS                               %%
+%%                                                                     %%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Perform some simple getopt and setopt with the level = otp options
+api_opt_simple_otp_options(suite) ->
+    [];
+api_opt_simple_otp_options(doc) ->
+    [];
+api_opt_simple_otp_options(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_opt_simple_otp_options,
+           fun() -> api_opt_simple_otp_options() end).
+
+api_opt_simple_otp_options() ->
+    Get = fun(S, Key) ->
+                  socket:getopt(S, otp, Key)
+          end,
+    Set = fun(S, Key, Val) ->
+                  socket:setopt(S, otp, Key, Val)
+          end,
+
+    Seq = 
+        [
+         %% *** Init part ***
+         #{desc => "create socket",
+           cmd  => fun(#{domain   := Domain, 
+                         type     := Type,
+                         protocol := Protocol} = State) ->
+                           Sock = sock_open(Domain, Type, Protocol),
+                           {ok, State#{sock => Sock}}
+                   end},
+         #{desc => "create dummy process",
+           cmd  => fun(State) ->
+                           Pid =  spawn_link(fun() -> 
+                                                     put(sname, "dummy"),
+                                                     receive
+                                                         die -> 
+                                                             exit(normal) 
+                                                     end 
+                                             end),
+                           {ok, State#{dummy => Pid}}
+                   end},
+
+         %% *** Check iow part ***
+         #{desc => "get iow",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           case Get(Sock, iow) of
+                               {ok, IOW} when is_boolean(IOW) ->
+                                   {ok, State#{iow => IOW}};
+                               {ok, InvalidIOW} ->
+                                   {error, {invalid, InvalidIOW}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% #{desc => "enable debug",
+         %%   cmd  => fun(#{sock := Sock}) ->
+         %%                   ok = socket:setopt(Sock, otp, debug, true)
+         %%           end},
+
+         #{desc => "set (new) iow",
+           cmd  => fun(#{sock := Sock, iow := OldIOW} = State) ->
+                           NewIOW = not OldIOW,
+                           case Set(Sock, iow, NewIOW) of
+                               ok ->
+                                   {ok, State#{iow => NewIOW}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "get (new) iow",
+           cmd  => fun(#{sock := Sock, iow := IOW}) ->
+                           case Get(Sock, iow) of
+                               {ok, IOW} ->
+                                   ok;
+                               {ok, InvalidIOW} ->
+                                   {error, {invalid, InvalidIOW}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** Check rcvbuf part ***
+         #{desc => "get rcvbuf",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           case Get(Sock, rcvbuf) of
+                               {ok, RcvBuf} when is_integer(RcvBuf) ->
+                                   {ok, State#{rcvbuf => RcvBuf}};
+                               {ok, {N, RcvBuf} = V} when is_integer(N) andalso 
+                                                          is_integer(RcvBuf) ->
+                                   {ok, State#{rcvbuf => V}};
+                               {ok, InvalidRcvBuf} ->
+                                   {error, {invalid, InvalidRcvBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "set (new) rcvbuf",
+           cmd  => fun(#{sock := Sock, rcvbuf := {OldN, OldRcvBuf}} = State) ->
+                           NewRcvBuf = {OldN+2, OldRcvBuf + 1024},
+                           case Set(Sock, rcvbuf, NewRcvBuf) of
+                               ok ->
+                                   {ok, State#{rcvbuf => NewRcvBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{sock := Sock, rcvbuf := OldRcvBuf} = State) when is_integer(OldRcvBuf) ->
+                           NewRcvBuf = 2 * OldRcvBuf,
+                           case Set(Sock, rcvbuf, NewRcvBuf) of
+                               ok ->
+                                   {ok, State#{rcvbuf => NewRcvBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{sock := Sock, rcvbuf := OldRcvBuf,
+                         type := stream,
+                         protocol := tcp} = State) when is_integer(OldRcvBuf) ->
+                           NewRcvBuf = {2, OldRcvBuf},
+                           case Set(Sock, rcvbuf, NewRcvBuf) of
+                               ok ->
+                                   {ok, State#{rcvbuf => NewRcvBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "get (new) rcvbuf",
+           cmd  => fun(#{sock := Sock, rcvbuf := RcvBuf}) ->
+                           case Get(Sock, rcvbuf) of
+                               {ok, RcvBuf} ->
+                                   ok;
+                               {ok, InvalidRcvBuf} ->
+                                   {error, {invalid, InvalidRcvBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** Check rcvctrlbuf part ***
+         #{desc => "get rcvctrlbuf",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           case Get(Sock, rcvctrlbuf) of
+                               {ok, RcvCtrlBuf} when is_integer(RcvCtrlBuf) ->
+                                   {ok, State#{rcvctrlbuf => RcvCtrlBuf}};
+                               {ok, InvalidRcvCtrlBuf} ->
+                                   {error, {invalid, InvalidRcvCtrlBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "set (new) rcvctrlbuf",
+           cmd  => fun(#{sock := Sock, rcvctrlbuf := OldRcvCtrlBuf} = State) ->
+                           NewRcvCtrlBuf = 2 * OldRcvCtrlBuf,
+                           case Set(Sock, rcvctrlbuf, NewRcvCtrlBuf) of
+                               ok ->
+                                   {ok, State#{rcvctrlbuf => NewRcvCtrlBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "get (new) rcvctrlbuf",
+           cmd  => fun(#{sock := Sock, rcvctrlbuf := RcvCtrlBuf}) ->
+                           case Get(Sock, rcvctrlbuf) of
+                               {ok, RcvCtrlBuf} ->
+                                   ok;
+                               {ok, InvalidRcvCtrlBuf} ->
+                                   {error, {invalid, InvalidRcvCtrlBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         %% *** Check rcvctrlbuf part ***
+         #{desc => "get rcvctrlbuf",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           case Get(Sock, rcvctrlbuf) of
+                               {ok, RcvCtrlBuf} when is_integer(RcvCtrlBuf) ->
+                                   {ok, State#{rcvctrlbuf => RcvCtrlBuf}};
+                               {ok, InvalidRcvCtrlBuf} ->
+                                   {error, {invalid, InvalidRcvCtrlBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "set (new) rcvctrlbuf",
+           cmd  => fun(#{sock := Sock, rcvctrlbuf := OldRcvCtrlBuf} = State) ->
+                           NewRcvCtrlBuf = 2 * OldRcvCtrlBuf,
+                           case Set(Sock, rcvctrlbuf, NewRcvCtrlBuf) of
+                               ok ->
+                                   {ok, State#{rcvctrlbuf => NewRcvCtrlBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "get (new) rcvctrlbuf",
+           cmd  => fun(#{sock := Sock, rcvctrlbuf := RcvCtrlBuf}) ->
+                           case Get(Sock, rcvctrlbuf) of
+                               {ok, RcvCtrlBuf} ->
+                                   ok;
+                               {ok, InvalidRcvCtrlBuf} ->
+                                   {error, {invalid, InvalidRcvCtrlBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** Check sndctrlbuf part ***
+         #{desc => "get sndctrlbuf",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           case Get(Sock, sndctrlbuf) of
+                               {ok, SndCtrlBuf} when is_integer(SndCtrlBuf) ->
+                                   {ok, State#{sndctrlbuf => SndCtrlBuf}};
+                               {ok, InvalidSndCtrlBuf} ->
+                                   {error, {invalid, InvalidSndCtrlBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "set (new) sndctrlbuf",
+           cmd  => fun(#{sock := Sock, sndctrlbuf := OldSndCtrlBuf} = State) ->
+                           NewSndCtrlBuf = 2 * OldSndCtrlBuf,
+                           case Set(Sock, sndctrlbuf, NewSndCtrlBuf) of
+                               ok ->
+                                   {ok, State#{sndctrlbuf => NewSndCtrlBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "get (new) sndctrlbuf",
+           cmd  => fun(#{sock := Sock, sndctrlbuf := SndCtrlBuf}) ->
+                           case Get(Sock, sndctrlbuf) of
+                               {ok, SndCtrlBuf} ->
+                                   ok;
+                               {ok, InvalidSndCtrlBuf} ->
+                                   {error, {invalid, InvalidSndCtrlBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** Check controlling-process part ***
+         #{desc => "verify self as controlling-process",
+           cmd  => fun(#{sock := Sock}) ->
+                           Self = self(),
+                           case Get(Sock, controlling_process) of
+                               {ok, Self} ->
+                                   ok;
+                               {ok, InvalidPid} ->
+                                   {error, {invalid, InvalidPid}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "set dummy as controlling-process",
+           cmd  => fun(#{sock := Sock, dummy := Dummy}) ->
+                           Set(Sock, controlling_process, Dummy)
+                   end},
+         #{desc => "verify dummy as controlling-process",
+           cmd  => fun(#{sock := Sock, dummy := Dummy}) ->
+                           case Get(Sock, controlling_process) of
+                               {ok, Dummy} ->
+                                   ok;
+                               {ok, InvalidPid} ->
+                                   {error, {invalid, InvalidPid}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         #{desc => "finish",
+           cmd  => fun(_) ->
+                           {ok, normal}
+                   end}
+        ],
+
+    i("start tcp (stream) evaluator"),
+    InitState1 = #{domain => inet, type => stream, protocol => tcp},
+    Tester1 = ?SEV_START("tcp-tester", Seq, InitState1),
+    i("await tcp evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Tester1]),
+
+    i("start udp (dgram) socket"),
+    InitState2 = #{domain => inet, type => dgram, protocol => udp},
+    Tester2 = ?SEV_START("udp-tester", Seq, InitState2),
+    i("await udp evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Tester2]).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Perform some simple operations with the rcvbuf otp option
+%% The operations we test here are only for type = stream and
+%% protocol = tcp.
+api_opt_simple_otp_rcvbuf_option(suite) ->
+    [];
+api_opt_simple_otp_rcvbuf_option(doc) ->
+    [];
+api_opt_simple_otp_rcvbuf_option(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(api_opt_simple_otp_rcvbuf_option,
+           fun() -> api_opt_simple_otp_rcvbuf_option() end).
+
+api_opt_simple_otp_rcvbuf_option() ->
+    Get = fun(S) ->
+                  socket:getopt(S, otp, rcvbuf)
+          end,
+    Set = fun(S, Val) ->
+                  socket:setopt(S, otp, rcvbuf, Val)
+          end,
+
+    ServerSeq = 
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, local_sa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester   := Tester,
+                         local_sa := LocalSA,
+                         lport    := Port}) ->
+                           ServerSA = LocalSA#{port => Port},
+                           ?SEV_ANNOUNCE_READY(Tester, init, ServerSA),
+                           ok
+                   end},
+
+
+         %% *** The actual test part ***
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "attempt to accept",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+
+         %% Recv with default size for (otp) rcvbuf
+         #{desc => "await continue (recv initial)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, recv) of
+                               {ok, MsgSz} ->
+                                   ?SEV_IPRINT("MsgSz: ~p", [MsgSz]),
+                                   {ok, State#{msg_sz => MsgSz}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt to recv",
+           cmd  => fun(#{sock := Sock, msg_sz := MsgSz} = _State) ->
+                           ?SEV_IPRINT("try recv ~w bytes when rcvbuf is ~s", 
+                                       [MsgSz,
+                                        case Get(Sock) of
+                                            {ok, RcvBuf} -> f("~w", [RcvBuf]);
+                                            {error, _}   -> "-"
+                                        end]),
+                           case socket:recv(Sock) of
+                               {ok, Data} when (size(Data) =:= MsgSz) ->
+                                   ok;
+                               {ok, Data} ->
+                                   {error, {invalid_msg_sz, MsgSz, size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv initial)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv),
+                           ok
+                   end},
+
+         %% Recv with new size (1) for (otp) rcvbuf
+         #{desc => "await continue (recv 1)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, recv) of
+                               {ok, NewRcvBuf} ->
+                                   ?SEV_IPRINT("set new rcvbuf: ~p", [NewRcvBuf]),
+                                   {ok, State#{rcvbuf => NewRcvBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt to setopt rcvbuf",
+           cmd  => fun(#{sock := Sock, rcvbuf := NewRcvBuf} = _State) ->
+                           case Set(Sock, NewRcvBuf) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt to recv",
+           cmd  => fun(#{sock := Sock, msg_sz := MsgSz} = _State) ->
+                           case socket:recv(Sock) of
+                               {ok, Data} when (size(Data) =:= MsgSz) ->
+                                   ok;
+                               {ok, Data} ->
+                                   {error, {invalid_msg_sz, MsgSz, size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv),
+                           ok
+                   end},
+
+         %% Recv with new size (2) for (otp) rcvbuf
+         #{desc => "await continue (recv 2)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, recv) of
+                               {ok, NewRcvBuf} ->
+                                   ?SEV_IPRINT("set new rcvbuf: ~p", [NewRcvBuf]),
+                                   {ok, State#{rcvbuf => NewRcvBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt to setopt rcvbuf",
+           cmd  => fun(#{sock := Sock, rcvbuf := NewRcvBuf} = _State) ->
+                           case Set(Sock, NewRcvBuf) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt to recv",
+           cmd  => fun(#{sock := Sock, msg_sz := MsgSz} = _State) ->
+                           case socket:recv(Sock) of
+                               {ok, Data} when (size(Data) =:= MsgSz) ->
+                                   ok;
+                               {ok, Data} ->
+                                   {error, {invalid_msg_sz, MsgSz, size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv),
+                           ok
+                   end},
+
+         %% Recv with new size (3) for (otp) rcvbuf
+         #{desc => "await continue (recv 3, truncated)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, recv) of
+                               {ok, {ExpSz, NewRcvBuf}} ->
+                                   {ok, State#{msg_sz => ExpSz,
+                                               rcvbuf => NewRcvBuf}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt to setopt rcvbuf",
+           cmd  => fun(#{sock := Sock, rcvbuf := NewRcvBuf} = _State) ->
+                           case Set(Sock, NewRcvBuf) of
+                               ok ->
+                                   ?SEV_IPRINT("set new rcvbuf: ~p", [NewRcvBuf]),
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt to recv",
+           cmd  => fun(#{sock := Sock, msg_sz := MsgSz} = _State) ->
+                           ?SEV_IPRINT("try recv ~w bytes of data", [MsgSz]),
+                           case socket:recv(Sock) of
+                               {ok, Data} when (size(Data) =:= MsgSz) ->
+                                   ok;
+                               {ok, Data} ->
+                                   {error, {invalid_msg_sz, MsgSz, size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv),
+                           ok
+                   end},
+
+
+         %% Termination
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket(s)",
+           cmd  => fun(#{lsock := LSock, sock := Sock} = State) ->
+                           sock_close(Sock),
+                           sock_close(LSock),
+                           State1 = maps:remove(sock,  State),
+                           State2 = maps:remove(lport, State1),
+                           State3 = maps:remove(lsock, State2),
+                           {ok, State3}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, ServerSA} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester    => Tester,
+                                       server_sa => ServerSA}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect)
+                   end},
+         #{desc => "connect to server",
+           cmd  => fun(#{sock := Sock, server_sa := SSA}) ->
+                           socket:connect(Sock, SSA)
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+
+         #{desc => "await continue (send initial)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, send) of
+                               {ok, Data} ->
+                                   {ok, State#{data => Data}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "send (initial) data to server",
+           cmd  => fun(#{sock := Sock, data := Data} = _State) ->
+                           ?SEV_IPRINT("try send ~w bytes", [size(Data)]),
+                           socket:send(Sock, Data)
+                   end},
+         #{desc => "announce ready (send initial)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send),
+                           ok
+                   end},
+
+         #{desc => "await continue (send 1)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send)
+                   end},
+         #{desc => "send (1) data to server",
+           cmd  => fun(#{sock := Sock, data := Data}) ->
+                           ?SEV_IPRINT("try send ~w bytes", [size(Data)]),
+                           socket:send(Sock, Data)
+                   end},
+         #{desc => "announce ready (send 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send),
+                           ok
+                   end},
+
+         #{desc => "await continue (send 2)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send)
+                   end},
+         #{desc => "send (2) data to server",
+           cmd  => fun(#{sock := Sock, data := Data}) ->
+                           ?SEV_IPRINT("try send ~w bytes", [size(Data)]),
+                           socket:send(Sock, Data)
+                   end},
+         #{desc => "announce ready (send 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send),
+                           ok
+                   end},
+
+         #{desc => "await continue (send 3)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send)
+                   end},
+         #{desc => "send (3) data to server",
+           cmd  => fun(#{sock := Sock, data := Data}) ->
+                           ?SEV_IPRINT("try send ~w bytes", [size(Data)]),
+                           socket:send(Sock, Data)
+                   end},
+         #{desc => "announce ready (send 3)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send),
+                           ok
+                   end},
+
+
+         %% Termination
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock}) ->
+                           socket:close(Sock)
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Server} = _State) ->
+                           _MRef = erlang:monitor(process, Server),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Client} = _State) ->
+                           _MRef = erlang:monitor(process, Client),
+                           ok
+                   end},
+         #{desc => "order server start",
+           cmd  => fun(#{server := Server}) ->
+                           ?SEV_ANNOUNCE_START(Server)
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Server} = State) ->
+                           {ok, ServerSA} = ?SEV_AWAIT_READY(Server, server, init),
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+         #{desc => "order client start",
+           cmd  => fun(#{client    := Client,
+                         server_sa := ServerSA}) ->
+                           ?SEV_ANNOUNCE_START(Client, ServerSA),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, init)
+                   end},
+
+
+         %% The actual test (connecting)
+         #{desc => "order server accept (accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, accept),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client continue (connect)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, connect),
+                           ok
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, connect)
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, accept)
+                   end},
+
+         %% The actual test (initial part)
+         #{desc => "order client continue (send initial)",
+           cmd  => fun(#{client := Client, data := Data} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Data),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order server continue (recv initial)",
+           cmd  => fun(#{server := Server, data := Data} = _State) ->
+                           ExpMsgSz = size(Data),
+                           ?SEV_ANNOUNCE_CONTINUE(Server, recv, ExpMsgSz),
+                           ok
+                   end},
+         #{desc => "await client ready (send initial)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, client, send,
+                                                 [{server, Server}]) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await server ready (recv initial)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Server, client, recv,
+                                                 [{client, Client}]) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% The actual test (part 1)
+         #{desc => "order client continue (send 1)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order server continue (recv 1)",
+           cmd  => fun(#{server := Server, data := Data} = _State) ->
+                           MsgSz     = size(Data),
+                           NewRcvBuf = {2 + (MsgSz div 1024), 1024},
+                           ?SEV_ANNOUNCE_CONTINUE(Server, recv, NewRcvBuf),
+                           ok
+                   end},
+         #{desc => "await client ready (send 1)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, client, send,
+                                                 [{server, Server}]) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await server ready (recv 1)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Server, client, recv,
+                                                 [{client, Client}]) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% The actual test (part 2)
+         #{desc => "order client continue (send 2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order server continue (recv 2)",
+           cmd  => fun(#{server := Server, data := Data} = _State) ->
+                           MsgSz     = size(Data),
+                           NewRcvBuf = {2 + (MsgSz div 2048), 2048},
+                           ?SEV_ANNOUNCE_CONTINUE(Server, recv, NewRcvBuf),
+                           ok
+                   end},
+         #{desc => "await client ready (send 2)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, client, send,
+                                                 [{server, Server}]) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await server ready (recv 2)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Server, client, recv,
+                                                 [{client, Client}]) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% The actual test (part 3)
+         #{desc => "order client continue (send 3)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order server continue (recv 3)",
+           cmd  => fun(#{server := Server, data := Data} = _State) ->
+                           MsgSz     = size(Data),
+                           BufSz     = 2048,
+                           N         = MsgSz div BufSz - 1,
+                           NewRcvBuf = {N, BufSz},
+                           ?SEV_ANNOUNCE_CONTINUE(Server, recv,
+                                                  {N*BufSz, NewRcvBuf})
+                   end},
+         #{desc => "await client ready (send 3)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, client, send,
+                                                 [{server, Server}]) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await server ready (recv 3)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Server, client, recv,
+                                                 [{client, Client}]) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         %% *** Terminate server ***
+         #{desc => "order client terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client down",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client,    State),
+                           {ok, State1}
+                   end},
+         #{desc => "order server terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server down",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server,    State),
+                           State2 = maps:remove(server_sa, State1),
+                           {ok, State2}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    %% Create a data binary of 6*1024 bytes
+    Data      = list_to_binary(lists:duplicate(6*4, lists:seq(0, 255))),
+    InitState = #{domain => inet,
+                  data   => Data},
+
+    i("create server evaluator"),
+    ServerInitState = #{domain => maps:get(domain, InitState)},
+    Server          = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("create client evaluator"),
+    ClientInitState = #{host   => local_host(),
+                        domain => maps:get(domain, InitState)},
+    Client          = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("create tester evaluator"),
+    TesterInitState = InitState#{server => Server#ev.pid,
+                                 client => Client#ev.pid},
+    Tester          = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Perform some simple getopt and setopt with the level = otp options
+api_opt_simple_otp_controlling_process(suite) ->
+    [];
+api_opt_simple_otp_controlling_process(doc) ->
+    [];
+api_opt_simple_otp_controlling_process(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(api_opt_simple_otp_controlling_process,
+           fun() -> api_opt_simple_otp_controlling_process() end).
+
+api_opt_simple_otp_controlling_process() ->
+    Get = fun(S, Key) ->
+                  socket:getopt(S, otp, Key)
+          end,
+    Set = fun(S, Key, Val) ->
+                  socket:setopt(S, otp, Key, Val)
+          end,
+
+    ClientSeq =
+        [
+         %% *** Init part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, Sock} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester,
+                                       sock   => Sock}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "verify tester as controlling-process",
+           cmd  => fun(#{tester := Tester, sock := Sock} = _State) ->
+                           case Get(Sock, controlling_process) of
+                               {ok, Tester} ->
+                                   ok;
+                               {ok, InvalidPid} ->
+                                   {error, {invalid, InvalidPid}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt invalid controlling-process transfer (to self)",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           case Set(Sock, controlling_process, self()) of
+                               {error, not_owner} ->
+                                   ok;
+                               ok ->
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (not owner)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, not_owner),
+                           ok
+                   end},
+         #{desc => "await continue (owner)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, owner)
+                   end},
+         #{desc => "verify self as controlling-process",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           Self = self(),
+                           case Get(Sock, controlling_process) of
+                               {ok, Self} ->
+                                   ok;
+                               {ok, InvalidPid} ->
+                                   {error, {invalid, InvalidPid}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt controlling-process transfer to tester",
+           cmd  => fun(#{tester := Tester, sock := Sock} = _State) ->
+                           Set(Sock, controlling_process, Tester)
+                   end},
+         #{desc => "attempt invalid controlling-process transfer (to self)",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           case Set(Sock, controlling_process, self()) of
+                               {error, not_owner} ->
+                                   ok;
+                               ok ->
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (owner)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, owner),
+                           ok
+
+                   end},
+         
+         %% *** Termination ***
+         #{desc => "await termination",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           ?SEV_AWAIT_TERMINATE(Tester, tester),
+                           State1 = maps:remove(tester, State),
+                           State2 = maps:remove(sock, State1),
+                           {ok, State2}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "create socket",
+           cmd  => fun(#{domain   := Domain, 
+                         type     := Type,
+                         protocol := Protocol} = State) ->
+                           Sock = sock_open(Domain, Type, Protocol),
+                           {ok, State#{sock => Sock}}
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Client} = _State) ->
+                           _MRef = erlang:monitor(process, Client),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "verify self as controlling-process",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           Self = self(),
+                           case Get(Sock, controlling_process) of
+                               {ok, Self} ->
+                                   ok;
+                               {ok, InvalidPid} ->
+                                   {error, {invalid, InvalidPid}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order (client) start",
+           cmd  => fun(#{client := Client, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Client, Sock),
+                           ok
+                   end},
+         #{desc => "await (client) ready (not owner)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, not_owner)
+                   end},
+         #{desc => "attempt controlling-process transfer to client",
+           cmd  => fun(#{client := Client, sock := Sock} = _State) ->
+                           Set(Sock, controlling_process, Client)
+                   end},
+         #{desc => "verify client as controlling-process",
+           cmd  => fun(#{client := Client, sock := Sock} = _State) ->
+                           case Get(Sock, controlling_process) of
+                               {ok, Client} ->
+                                   ok;
+                               {ok, InvalidPid} ->
+                                   {error, {invalid, InvalidPid}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt invalid controlling-process transfer (to self)",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           case Set(Sock, controlling_process, self()) of
+                               {error, not_owner} ->
+                                   ok;
+                               ok ->
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order (client) continue (owner)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, owner),
+                           ok
+                   end},
+         #{desc => "await (client) ready (2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, owner),
+                           ok
+                   end},
+         #{desc => "verify self as controlling-process",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           Self = self(),
+                           case Get(Sock, controlling_process) of
+                               {ok, Self} ->
+                                   ok;
+                               {ok, InvalidPid} ->
+                                   {error, {invalid, InvalidPid}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** Termination ***
+         #{desc => "order (client) terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           {ok, maps:remove(client, State)}
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           sock_close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start tcp (stream) client evaluator"),
+    ClientInitState1 = #{},
+    Client1 = ?SEV_START("tcp-client", ClientSeq, ClientInitState1),
+
+    i("start tcp (stream) tester evaluator"),
+    TesterInitState1 = #{domain   => inet, 
+                         type     => stream, 
+                         protocol => tcp,
+                         client   => Client1#ev.pid},
+    Tester1 = ?SEV_START("tcp-tester", TesterSeq, TesterInitState1),
+
+    i("await tcp evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester1, Client1]),
+
+    i("start udp (dgram) client evaluator"),
+    ClientInitState2 = #{},
+    Client2 = ?SEV_START("udp-client", ClientSeq, ClientInitState2),
+
+    i("start udp (dgram) tester evaluator"),
+    TesterInitState2 = #{domain   => inet, 
+                         type     => dgram, 
+                         protocol => udp,
+                         client   => Client2#ev.pid},
+    Tester2 = ?SEV_START("udp-tester", TesterSeq, TesterInitState2),
+
+    i("await udp evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester2, Client2]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option acceptconn for UDP.
+%% This should be possible to get but not set.
+
+api_opt_sock_acceptconn_udp(suite) ->
+    [];
+api_opt_sock_acceptconn_udp(doc) ->
+    [];
+api_opt_sock_acceptconn_udp(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(api_opt_sock_acceptconn_udp,
+           fun() ->
+                   has_support_sock_acceptconn()
+           end,
+           fun() -> api_opt_sock_acceptconn_udp() end).
+
+
+
+api_opt_sock_acceptconn_udp() ->
+    Opt = acceptconn,
+    Set = fun(S, Val) ->
+                  socket:setopt(S, socket, Opt, Val)
+          end,
+    Get = fun(S) ->
+                  socket:getopt(S, socket, Opt)
+          end,
+
+    TesterSeq =
+        [
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "[get] verify socket (before bind)",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "Not accepting connections"),
+                                   ok;
+                               {ok, true} ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Accepting connections"),
+                                   {error, {unexpected_success, {Opt, true}}};
+                               {error, enoprotoopt = Reason} ->
+                                   %% On some platforms this is not accepted
+                                   %% for UDP, so skip this part (UDP).
+                                   ?SEV_EPRINT("Expected Failure: "
+                                               "~p => SKIP", [Reason]),
+                                   (catch socket:close(Sock)),
+                                   {skip, Reason};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[set] verify socket (before bind)",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           case Set(Sock, true) of
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p",
+                                               [Reason]),
+                                   ok;
+                               ok ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Set acceptconn (=true)"),
+                                   {error, unexpected_success}
+                           end
+                   end},
+
+         #{desc => "bind socket to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "[get] verify socket (after bind)",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "Not accepting connections"),
+                                   ok;
+                               {ok, true} ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Accepting connections"),
+                                   {error, {unexpected_success, {Opt, true}}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[set] verify socket (after bind)",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           case Set(Sock, true) of
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p",
+                                               [Reason]),
+                                   ok;
+                               ok ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Set acceptconn (=true)"),
+                                   {error, unexpected_success}
+                           end
+                   end},
+
+         %% *** Termination ***
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           socket:close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    Domain = inet,
+
+    i("start tester evaluator"),
+    InitState = #{domain  => Domain},
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option acceptconn for TCP.
+%% This should be possible to get but not set.
+
+api_opt_sock_acceptconn_tcp(suite) ->
+    [];
+api_opt_sock_acceptconn_tcp(doc) ->
+    [];
+api_opt_sock_acceptconn_tcp(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(api_opt_sock_acceptconn_tcp,
+           fun() ->
+                   has_support_sock_acceptconn()
+           end,
+           fun() -> api_opt_sock_acceptconn_tcp() end).
+
+
+
+api_opt_sock_acceptconn_tcp() ->
+    Opt = acceptconn,
+    Set = fun(S, Val) ->
+                  socket:setopt(S, socket, Opt, Val)
+          end,
+    Get = fun(S) ->
+                  socket:getopt(S, socket, Opt)
+          end,
+
+    TesterSeq =
+        [
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "[get] verify listen socket (before bind)",
+           cmd  => fun(#{lsock := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "Not accepting connections"),
+                                   ok;
+                               {ok, true} ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Accepting connections"),
+                                   {error, {unexpected_success, {Opt, true}}};
+                               {error, enoprotoopt = Reason} ->
+                                   ?SEV_EPRINT("Expected Failure: "
+                                               "~p => SKIP", [Reason]),
+                                   (catch socket:close(Sock)),
+                                   {skip, Reason};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[set] verify listen socket (before bind)",
+           cmd  => fun(#{lsock := Sock} = _State) ->
+                           case Set(Sock, true) of
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   ok;
+                               ok ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Set acceptconn (=true)"),
+                                   {error, unexpected_success}
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "bind listen socket to local address",
+           cmd  => fun(#{lsock := Sock, local_sa := LSA} = State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{server_sa => LSA#{port => Port}}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "[get] verify listen socket (after bind)",
+           cmd  => fun(#{lsock := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "Not accepting connections"),
+                                   ok;
+                               {ok, true} ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Accepting connections"),
+                                   {error, {unexpected_success, {Opt, true}}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[set] verify listen socket (after bind)",
+           cmd  => fun(#{lsock := Sock} = _State) ->
+                           case Set(Sock, true) of
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   ok;
+                               ok ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Set acceptconn (=true)"),
+                                   {error, unexpected_success}
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "make listen socket accept connections",
+           cmd  => fun(#{lsock := Sock} = _State) ->
+                           case socket:listen(Sock) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "[get] verify listen socket (after listen)",
+           cmd  => fun(#{lsock := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, true} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "Accepting connections"),
+                                   ok;
+                               {ok, false} ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Not accepting connections"),
+                                   {error, {unexpected_success, {Opt, false}}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[set] verify listen socket (after listen)",
+           cmd  => fun(#{lsock := Sock} = _State) ->
+                           case Set(Sock, false) of
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   ok;
+                               ok ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Set acceptconn (=false)"),
+                                   {error, unexpected_success}
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "create (connecting) socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{csockc => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "bind connecting socket to local address",
+           cmd  => fun(#{csockc := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "[get] verify connecting socket (before connect)",
+           cmd  => fun(#{csockc := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "Not accepting connections"),
+                                   ok;
+                               {ok, true} ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Accepting connections"),
+                                   {error, {unexpected_success, {Opt, true}}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[set] verify connecting socket (before connect)",
+           cmd  => fun(#{csockc := Sock} = _State) ->
+                           case Set(Sock, true) of
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   ok;
+                               ok ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Set acceptconn (=true)"),
+                                   {error, unexpected_success}
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "connect to server",
+           cmd  => fun(#{csockc := Sock, server_sa := SSA} = _State) ->
+                           case socket:connect(Sock, SSA) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "accept connection",
+           cmd  => fun(#{lsock := Sock} = State) ->
+                           case socket:accept(Sock) of
+                               {ok, CSock} ->
+                                   {ok, State#{csocks => CSock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "[get] verify connecting socket (after connect)",
+           cmd  => fun(#{csockc := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "Not accepting connections"),
+                                   ok;
+                               {ok, true} ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Accepting connections"),
+                                   {error, {unexpected_success, {Opt, true}}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[set] verify connecting socket (after connect)",
+           cmd  => fun(#{csockc := Sock} = _State) ->
+                           case Set(Sock, true) of
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   ok;
+                               ok ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Set acceptconn (=true)"),
+                                   {error, unexpected_success}
+                           end
+                   end},
+
+         #{desc => "[get] verify connected socket",
+           cmd  => fun(#{csocks := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "Not accepting connections"),
+                                   ok;
+                               {ok, true} ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Accepting connections"),
+                                   {error, {unexpected_success, {Opt, true}}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[set] verify connected socket",
+           cmd  => fun(#{csocks := Sock} = _State) ->
+                           case Set(Sock, true) of
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   ok;
+                               ok ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Set acceptconn (=true)"),
+                                   {error, unexpected_success}
+                           end
+                   end},
+
+         #{desc => "[get] verify listen socket (after connect)",
+           cmd  => fun(#{lsock := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, true} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "Accepting connections"),
+                                   ok;
+                               {ok, false} ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Not accepting connections"),
+                                   {error, {unexpected_success, {Opt, false}}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[set] verify listen socket (after connect)",
+           cmd  => fun(#{lsock := Sock} = _State) ->
+                           case Set(Sock, false) of
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   ok;
+                               ok ->
+                                   ?SEV_EPRINT("Unexpected Success: "
+                                               "Set acceptconn (=false)"),
+                                   {error, unexpected_success}
+                           end
+                   end},
+
+         %% *** Termination ***
+         #{desc => "close connecting socket(s)",
+           cmd  => fun(#{csockc := Sock} = State0) ->
+                           socket:close(Sock),
+                           State1 = maps:remove(csockc, State0),
+                           State2 = maps:remove(csocks, State1), %% Auto-close
+                           {ok, maps:remove(csockc, State2)}
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{lsock := Sock} = State) ->
+                           socket:close(Sock),
+                           {ok, maps:remove(lsock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    Domain = inet,
+
+    i("start tester evaluator"),
+    InitState = #{domain  => Domain},
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option acceptfilter. PLACEHOLDER!
+
+api_opt_sock_acceptfilter(suite) ->
+    [];
+api_opt_sock_acceptfilter(doc) ->
+    [];
+api_opt_sock_acceptfilter(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(api_opt_sock_acceptfilter,
+           fun() -> not_yet_implemented() end,
+           fun() -> ok end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option bindtodevice.
+%% It has not always been possible to 'get' this option
+%% (atleast on linux).
+
+api_opt_sock_bindtodevice(suite) ->
+    [];
+api_opt_sock_bindtodevice(doc) ->
+    [];
+api_opt_sock_bindtodevice(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(api_opt_sock_bindtodevice,
+           fun() -> has_support_sock_bindtodevice() end,
+           fun() -> api_opt_sock_bindtodevice() end).
+
+
+api_opt_sock_bindtodevice() ->
+    Opt = bindtodevice,
+    Set = fun(S, Val) ->
+                  socket:setopt(S, socket, Opt, Val)
+          end,
+    Get = fun(S) ->
+                  socket:getopt(S, socket, Opt)
+          end,
+
+    TesterSeq =
+        [
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case ?LIB:which_local_host_info(Domain) of
+                               {ok, #{name := Name, addr := Addr}} ->
+                                   ?SEV_IPRINT("local host info (~p): "
+                                               "~n   Name: ~p"
+                                               "~n   Addr: ~p",
+                                               [Domain, Name, Addr]),
+                                   LSA = #{family => Domain,
+                                           addr   => Addr},
+                                   {ok, State#{dev      => Name,
+                                               local_sa => LSA}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "create UDP socket 1",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{usock1 => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "create UDP socket 2",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{usock2 => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "create TCP socket 1",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{tsock1 => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "create TCP socket 2",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{tsock2 => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "[get] verify UDP socket 1 (before bindtodevice)",
+           cmd  => fun(#{usock1 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Dev} ->
+                                   ?SEV_IPRINT("Expected Success: ~p", [Dev]),
+                                   ok;
+                               {error, enoprotoopt = Reason} ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p => SKIP",
+					       [Reason]),
+                                   {skip, Reason};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[get] verify UDP socket 2 (before bind)",
+           cmd  => fun(#{usock2 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Dev} ->
+                                   ?SEV_IPRINT("Expected Success: ~p", [Dev]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[get] verify TCP socket 1 (before bindtodevice)",
+           cmd  => fun(#{tsock1 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Dev} ->
+                                   ?SEV_IPRINT("Expected Success: ~p", [Dev]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[get] verify TCP socket 2 (before bind)",
+           cmd  => fun(#{tsock2 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Dev} ->
+                                   ?SEV_IPRINT("Expected Success: ~p", [Dev]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "Bind UDP socket 1 to device",
+           cmd  => fun(#{usock1 := Sock, dev := Dev} = State) ->
+                           case Set(Sock, Dev) of
+                               ok ->
+                                   ?SEV_IPRINT("Expected Success"),
+                                   ok;
+                               {error, eperm = Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   (catch socket:close(Sock)),
+                                   {ok, State#{usock1 => skip}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Bind UDP socket 2 to local address",
+           cmd  => fun(#{usock2 := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ?SEV_IPRINT("Expected Success"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Bind TCP socket 1 to device",
+           cmd  => fun(#{usock1 := USock1,
+                         tsock1 := Sock, dev := Dev} = State) ->
+                           case Set(Sock, Dev) of
+                               ok ->
+                                   ?SEV_IPRINT("Expected Success"),
+                                   ok;
+                               {error, eperm = Reason} when (USock1 =:= skip) ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   {skip, Reason};
+                               {error, eperm = Reason} ->
+                                   ?SEV_IPRINT("Expected Failure: ~p", [Reason]),
+                                   (catch socket:close(Sock)),
+                                   {ok, State#{tsock1 => skip}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Bind TCP socket 2 to local address",
+           cmd  => fun(#{tsock2 := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ?SEV_IPRINT("Expected Success"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "[get] verify UDP socket 1 (after bindtodevice)",
+           cmd  => fun(#{usock1 := skip} = _State) ->
+                           ?SEV_IPRINT("SKIP'ed (previous eperm)"),
+                           ok;
+                      (#{usock1 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Dev} ->
+                                   ?SEV_IPRINT("Expected Success: ~p", [Dev]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[get] verify UDP socket 2 (after bind)",
+           cmd  => fun(#{usock2 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Dev} ->
+                                   ?SEV_IPRINT("Expected Success: ~p", [Dev]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[get] verify TCP socket 1 (after bindtodevice)",
+           cmd  => fun(#{tsock1 := skip} = _State) ->
+                           ?SEV_IPRINT("SKIP'ed (previous eperm)"),
+                           ok;
+                      (#{tsock1 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Dev} ->
+                                   ?SEV_IPRINT("Expected Success: ~p", [Dev]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[get] verify TCP socket 2 (after bind)",
+           cmd  => fun(#{tsock2 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Dev} ->
+                                   ?SEV_IPRINT("Expected Success: ~p", [Dev]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         %% *** Termination ***
+         #{desc => "close UDP socket 1",
+           cmd  => fun(#{usock1 := skip} = State) ->
+                           ?SEV_IPRINT("SKIP'ed (already closed)"),
+                           {ok, maps:remove(usock1, State)};
+                      (#{usock1 := Sock} = State) ->
+                           socket:close(Sock),
+                           {ok, maps:remove(usock1, State)}
+                   end},
+         #{desc => "close UDP socket 2",
+           cmd  => fun(#{usock2 := Sock} = State) ->
+                           socket:close(Sock),
+                           {ok, maps:remove(usock2, State)}
+                   end},
+         #{desc => "close TCP socket 1",
+           cmd  => fun(#{tsock1 := skip} = State) ->
+                           ?SEV_IPRINT("SKIP'ed (already closed)"),
+                           {ok, maps:remove(tsock1, State)};
+                      (#{tsock1 := Sock} = State) ->
+                           socket:close(Sock),
+                           {ok, maps:remove(tsock1, State)}
+                   end},
+         #{desc => "close TCP socket 2",
+           cmd  => fun(#{tsock2 := Sock} = State) ->
+                           socket:close(Sock),
+                           {ok, maps:remove(tsock2, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    Domain = inet,
+
+    i("start tester evaluator"),
+    InitState = #{domain  => Domain},
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option broadcast.
+%% Make it possible for datagram sockets to send packets to a broadcast
+%% address (IPv4 only).
+
+api_opt_sock_broadcast(suite) ->
+    [];
+api_opt_sock_broadcast(doc) ->
+    [];
+api_opt_sock_broadcast(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(api_opt_sock_broadcast,
+           fun() -> has_support_sock_broadcast() end,
+           fun() -> api_opt_sock_broadcast() end).
+
+
+api_opt_sock_broadcast() ->
+    Opt    = broadcast,
+    Set    = fun(S, Val) when is_boolean(Val) ->
+                     socket:setopt(S, socket, Opt, Val)
+             end,
+    Get    = fun(S) ->
+                     socket:getopt(S, socket, Opt)
+             end,
+
+    TesterSeq =
+        [
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case ?LIB:which_local_host_info(Domain) of
+                               {ok, #{name      := Name,
+                                      addr      := Addr,
+                                      broadaddr := BAddr}} ->
+                                   ?SEV_IPRINT("local host info: "
+                                               "~n   Name:           ~p"
+                                               "~n   Addr:           ~p"
+                                               "~n   Broadcast Addr: ~p",
+                                               [Name, Addr, BAddr]),
+                                   LSA = #{family => Domain,
+                                           addr   => Addr},
+                                   BSA = #{family => Domain,
+                                           addr   => BAddr},
+                                   {ok, State#{lsa => LSA,
+                                               bsa => BSA}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "[socket 1] create UDP socket (listening 1)",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock1 => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 1] Bind UDP socket (to limited broadcast address)",
+           cmd  => fun(#{sock1 := Sock} = State) ->
+			   BSA = #{family => inet,
+				   addr   => broadcast},
+                           ?SEV_IPRINT("Try bind (socket 1) to: "
+                                       "~n   ~p", [BSA]),
+                           case socket:bind(Sock, BSA) of
+                               {ok, Port} ->
+                                   ?SEV_IPRINT("Expected Success (bound): ~p",
+                                               [Port]),
+                                   {ok, State#{sa1 => BSA#{port => Port}}};
+                               {error, eaddrnotavail = Reason} ->
+                                   ?SEV_IPRINT("~p => "
+					       "SKIP limited broadcast test",
+					       [Reason]),
+                                   {ok, State#{sa1 => skip}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 1] UDP socket sockname",
+           cmd  => fun(#{sa1 := skip} = _State) ->
+                           ?SEV_IPRINT("SKIP limited broadcast test"),
+                           ok;
+		      (#{sock1 := Sock} = _State) ->
+			   case socket:sockname(Sock) of
+			       {ok, SA} ->
+				   ?SEV_IPRINT("SA: ~p", [SA]),
+				   ok;
+			       {error, _} = ERROR ->
+				   ERROR
+			   end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "[socket 2] create UDP socket (listening 2)",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock2 => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 2] Bind UDP socket (to subnet-directed broadcast address)",
+           cmd  => fun(#{sock2 := Sock,
+			 bsa   := BSA} = State) ->
+                           ?SEV_IPRINT("Try bind (socket 1) to: "
+                                       "~n   ~p", [BSA]),
+                           case socket:bind(Sock, BSA) of
+                               {ok, Port} ->
+                                   ?SEV_IPRINT("Expected Success (bound): ~p",
+                                               [Port]),
+                                   {ok, State#{sa2 => BSA#{port => Port}}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 2] UDP socket sockname",
+           cmd  => fun(#{sock2 := Sock} = _State) ->
+                           case socket:sockname(Sock) of
+                               {ok, SA} ->
+				   ?SEV_IPRINT("SA: ~p", [SA]),
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "[socket 3] create UDP socket (sender)",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock3 => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 3][get] verify UDP socket (before bind and set)",
+           cmd  => fun(#{sock3 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "broadcast not allowed"),
+                                   ok;
+                               {ok, true} ->
+                                   ?SEV_IPRINT("Unexpected Success result: "
+                                               "broadcast already allowed"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 3] Try make broadcast allowed",
+           cmd  => fun(#{sock3 := Sock} = _State) ->
+                           case Set(Sock, true) of
+                               ok ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "broadcast now allowed"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 3] verify UDP socket broadcast allowed",
+           cmd  => fun(#{sock3 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, true} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "broadcast allowed"),
+                                   ok;
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Unexpected Success result: "
+                                               "broadcast *not* allowed"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 3] Bind UDP socket (to local address)",
+           cmd  => fun(#{sock3 := Sock, lsa := LSA} = State) ->
+                           ?SEV_IPRINT("Try bind (socket 2) to: "
+                                       "~n   ~p", [LSA]),
+                           case socket:bind(Sock, LSA) of
+                               {ok, Port} ->
+                                   ?SEV_IPRINT("Expected Success (bound): ~p",
+                                               [Port]),
+                                   {ok, State#{sa3 => LSA#{port => Port}}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 3] verify UDP socket (after set)",
+           cmd  => fun(#{sock3 := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, true} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "broadcast allowed"),
+                                   ok;
+                               {ok, false} ->
+                                   ?SEV_IPRINT("Unexpected Success result: "
+                                               "broadcast not allowed"),
+                                   {error, not_allowed};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+	 ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "[socket 3] try send to limited broadcast address",
+           cmd  => fun(#{sa1 := skip} = _State) ->
+                           ?SEV_IPRINT("SKIP limited broadcast test"),
+			   ok;
+		      (#{sock3 := Sock,
+			 sa1   := Dest} = _State) ->
+			   Data = list_to_binary("hejsan"),
+			   ?SEV_IPRINT("try send to bradcast address: "
+				       "~n   ~p", [Dest]),
+			   case socket:sendto(Sock, Data, Dest) of
+			       ok ->
+				   ?SEV_IPRINT("Expected Success: "
+					       "broadcast message sent"),
+				   ok;
+			       {error, Reason} = ERROR ->
+				   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+				   ERROR
+			   end
+		   end},
+         #{desc => "[socket 1] try recv",
+           cmd  => fun(#{sa1 := skip} = _State) ->
+			   ?SEV_IPRINT("SKIP limited broadcast test"),
+			   ok;
+		      (#{sock1 := Sock} = State) ->
+                           case socket:recvfrom(Sock, 0, 5000) of
+                               {ok, _} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "received message"),
+                                   ok;
+                               {error, timeout = Reason} ->
+                                   %% Some platforms seem to balk at this.
+                                   %% It spossible to bind to this, and
+                                   %% send to it, but no data is received.
+                                   %% At some point we should investigate...
+                                   %% For now, we just skip this part of
+                                   %% the test...
+                                   ?SEV_IPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   {ok, State#{sa1 => skip}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+	 ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "[socket 3] try send to subnet-directed broadcast address",
+           cmd  => fun(#{sock3 := Sock,
+                         sa2   := Dest} = _State) ->
+                           Data = list_to_binary("hejsan"),
+                           ?SEV_IPRINT("try send to bradcast address: "
+                                       "~n   ~p", [Dest]),
+                           case socket:sendto(Sock, Data, Dest) of
+                               ok ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "broadcast message sent"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "[socket 2] try recv",
+           cmd  => fun(#{sock2 := Sock, sa1 := SA1} = _State) ->
+                           case socket:recvfrom(Sock, 0, 5000) of
+                               {ok, _} ->
+                                   ?SEV_IPRINT("Expected Success: "
+                                               "received message"),
+                                   ok;
+                               {error, timeout = Reason} when (SA1 =:= skip) ->
+                                   ?SEV_IPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   {skip, "receive timeout"};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+         %% *** Termination ***
+         #{desc => "[socket 3] close UDP socket (sender)",
+           cmd  => fun(#{sock3 := Sock} = State0) ->
+                           socket:close(Sock),
+			   State1 = maps:remove(sock3, State0),
+			   State2 = maps:remove(sa3,   State1),
+			   {ok, State2}
+                   end},
+         #{desc => "[socket 2] close UDP socket (listener 2)",
+           cmd  => fun(#{sock2 := Sock} = State0) ->
+                           socket:close(Sock),
+			   State1 = maps:remove(sock2, State0),
+			   State2 = maps:remove(sa2,   State1),
+                           {ok, State2}
+                   end},
+         #{desc => "[socket 1] close UDP socket (listener 1)",
+           cmd  => fun(#{sock1 := Sock} = State0) ->
+                           socket:close(Sock),
+			   State1 = maps:remove(sock1, State0),
+			   State2 = maps:remove(sa1,   State1),
+                           {ok, State2}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    Domain = inet,
+
+    i("start tester evaluator"),
+    InitState = #{domain => Domain},
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option debug.
+%% On linux, this test requires that the user running the test to have
+%% CAP_NET_ADMIN capabilities or be root (effective user ID of 0), 
+%% therefor we explicitly test for the result eacces when attempting to
+%% set, and skip if we get it.
+
+api_opt_sock_debug(suite) ->
+    [];
+api_opt_sock_debug(doc) ->
+    [];
+api_opt_sock_debug(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_opt_sock_debug,
+           fun() -> has_support_sock_debug() end,
+           fun() -> api_opt_sock_debug() end).
+
+
+api_opt_sock_debug() ->
+    Opt    = debug,
+    Set    = fun(S, Val) when is_integer(Val) ->
+                     socket:setopt(S, socket, Opt, Val)
+             end,
+    Get    = fun(S) ->
+                     socket:getopt(S, socket, Opt)
+             end,
+
+    TesterSeq =
+        [
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case ?LIB:which_local_host_info(Domain) of
+                               {ok, #{name      := Name,
+                                      addr      := Addr,
+                                      broadaddr := BAddr}} ->
+                                   ?SEV_IPRINT("local host info: "
+                                               "~n   Name:           ~p"
+                                               "~n   Addr:           ~p"
+                                               "~n   Broadcast Addr: ~p",
+                                               [Name, Addr, BAddr]),
+                                   LSA = #{family => Domain,
+                                           addr   => Addr},
+                                   BSA = #{family => Domain,
+                                           addr   => BAddr},
+                                   {ok, State#{lsa => LSA,
+                                               bsa => BSA}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "create UDP socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Get current debug value",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           case Get(Sock) of
+                               {ok, Debug} when is_integer(Debug) ->
+                                   ?SEV_IPRINT("Success: ~p", [Debug]),
+                                   {ok, State#{debug => Debug}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Try enable socket debug",
+           cmd  => fun(#{sock := Sock, debug := Debug} = State) ->
+			   NewDebug = Debug + 1,
+                           case Set(Sock, NewDebug) of
+                               ok ->
+                                   ?SEV_IPRINT("Expected Success"),
+                                   {ok, State#{debug => NewDebug}};
+                               {error, eacces = Reason} ->
+                                   ?SEV_EPRINT("NO ACCESS => SKIP"),
+                                   {skip, Reason};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Get current (new) debug value",
+           cmd  => fun(#{sock := Sock, debug := Debug} = _State) ->
+                           case Get(Sock) of
+                               {ok, Debug} when is_integer(Debug) ->
+                                   ?SEV_IPRINT("Success: ~p", [Debug]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+         %% *** Termination ***
+         #{desc => "close UDP socket",
+           cmd  => fun(#{sock := Sock} = State0) ->
+                           socket:close(Sock),
+			   State1 = maps:remove(sock, State0),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    Domain = inet,
+
+    i("start tester evaluator"),
+    InitState = #{domain => Domain},
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option domain.
+%% This is a read only option. Also not available on all platforms.
+
+api_opt_sock_domain(suite) ->
+    [];
+api_opt_sock_domain(doc) ->
+    [];
+api_opt_sock_domain(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_opt_sock_domain,
+           fun() -> has_support_sock_domain() end,
+           fun() -> api_opt_sock_domain() end).
+
+
+api_opt_sock_domain() ->
+    Opt = domain,
+    Get = fun(S) ->
+                  socket:getopt(S, socket, Opt)
+          end,
+
+    TesterSeq =
+        [
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case ?LIB:which_local_host_info(Domain) of
+                               {ok, #{name      := Name,
+                                      addr      := Addr,
+                                      broadaddr := BAddr}} ->
+                                   ?SEV_IPRINT("local host info: "
+                                               "~n   Name:           ~p"
+                                               "~n   Addr:           ~p"
+                                               "~n   Broadcast Addr: ~p",
+                                               [Name, Addr, BAddr]),
+                                   LSA = #{family => Domain,
+                                           addr   => Addr},
+                                   BSA = #{family => Domain,
+                                           addr   => BAddr},
+                                   {ok, State#{lsa => LSA,
+                                               bsa => BSA}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "create IPv4 UDP socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{usock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Get domain for the UDP socket",
+           cmd  => fun(#{domain := Domain, usock := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Domain} ->
+                                   ?SEV_IPRINT("Success: ~p", [Domain]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "create TCP socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{tsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Get domain for the TCP socket",
+           cmd  => fun(#{domain := Domain, tsock := Sock} = _State) ->
+                           case Get(Sock) of
+                               {ok, Domain} ->
+                                   ?SEV_IPRINT("Success: ~p", [Domain]),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+         %% *** Termination ***
+         #{desc => "close UDP socket",
+           cmd  => fun(#{usock := Sock} = State0) ->
+                           socket:close(Sock),
+			   State1 = maps:remove(usock, State0),
+                           {ok, State1}
+                   end},
+         #{desc => "close TCP socket",
+           cmd  => fun(#{tsock := Sock} = State0) ->
+                           socket:close(Sock),
+			   State1 = maps:remove(tsock, State0),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    Domain = inet,
+
+    i("start tester evaluator"),
+    InitState = #{domain => Domain},
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option dontroute.
+%% The man page has the following to say:
+%% "Don't send via a gateway, send only to directly connected hosts.
+%%  The same effect can be achieved by setting the MSG_DONTROUTE
+%%  flag on a socket send(2) operation."
+%% Since its "kind of" difficult to check if it actually takes an 
+%% effect (you would need a gateway for that and a machine "on the
+%% other side"), we only test if we can set and get the value.
+%% Better then nothing.
+
+api_opt_sock_dontroute(suite) ->
+    [];
+api_opt_sock_dontroute(doc) ->
+    [];
+api_opt_sock_dontroute(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_opt_sock_dontroute,
+           fun() -> has_support_sock_dontroute() end,
+           fun() -> api_opt_sock_dontroute() end).
+
+
+api_opt_sock_dontroute() ->
+    Opt    = dontroute,
+    Set    = fun(S, Val) when is_boolean(Val) ->
+                     socket:setopt(S, socket, Opt, Val)
+             end,
+    Get    = fun(S) ->
+                     socket:getopt(S, socket, Opt)
+             end,
+
+    TesterSeq =
+        [
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case ?LIB:which_local_host_info(Domain) of
+                               {ok, #{name      := Name,
+                                      addr      := Addr,
+                                      broadaddr := BAddr}} ->
+                                   ?SEV_IPRINT("local host info: "
+                                               "~n   Name:           ~p"
+                                               "~n   Addr:           ~p"
+                                               "~n   Broadcast Addr: ~p",
+                                               [Name, Addr, BAddr]),
+                                   LSA = #{family => Domain,
+                                           addr   => Addr},
+                                   BSA = #{family => Domain,
+                                           addr   => BAddr},
+                                   {ok, State#{lsa => LSA,
+                                               bsa => BSA}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "create UDP socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Get current value",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           case Get(Sock) of
+                               {ok, Val} when is_boolean(Val) ->
+                                   ?SEV_IPRINT("Success: ~p", [Val]),
+                                   {ok, State#{dontroute => Val}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Try change value",
+           cmd  => fun(#{sock := Sock, dontroute := Current} = State) ->
+			   New = not Current,
+                           ?SEV_IPRINT("Change from ~p to ~p", [Current, New]),
+                           case Set(Sock, New) of
+                               ok ->
+                                   ?SEV_IPRINT("Expected Success"),
+                                   {ok, State#{dontroute => New}};
+                               {error, eopnotsupp = Reason} ->
+                                   ?SEV_EPRINT("Expected Failure: ~p",
+					       [Reason]),
+                                   {skip, Reason};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Verify changed value",
+           cmd  => fun(#{sock := Sock, dontroute := Val} = _State) ->
+                           case Get(Sock) of
+                               {ok, Val} ->
+                                   ?SEV_IPRINT("Expected Success"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+         %% *** Termination ***
+         #{desc => "close UDP socket",
+           cmd  => fun(#{sock := Sock} = State0) ->
+                           socket:close(Sock),
+			   State1 = maps:remove(sock, State0),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    Domain = inet,
+
+    i("start tester evaluator"),
+    InitState = #{domain => Domain},
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option error. PLACEHOLDER!
+
+api_opt_sock_error(suite) ->
+    [];
+api_opt_sock_error(doc) ->
+    [];
+api_opt_sock_error(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_opt_sock_error,
+           fun() -> not_yet_implemented() end,
+           fun() -> ok end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option keepalive.
+%% This is bit tricky to test, partly because we have no control over
+%% the underlying TCP timeouts. So, for now, we just test that we can
+%% change the value.
+
+api_opt_sock_keepalive(suite) ->
+    [];
+api_opt_sock_keepalive(doc) ->
+    [];
+api_opt_sock_keepalive(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_opt_sock_keepalive,
+           fun() -> has_support_sock_keepalive() end,
+           fun() -> api_opt_sock_keepalive() end).
+
+
+api_opt_sock_keepalive() ->
+    Opt    = keepalive,
+    Set    = fun(S, Val) when is_boolean(Val) ->
+                     socket:setopt(S, socket, Opt, Val)
+             end,
+    Get    = fun(S) ->
+                     socket:getopt(S, socket, Opt)
+             end,
+
+    TesterSeq =
+        [
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case ?LIB:which_local_host_info(Domain) of
+                               {ok, #{name      := Name,
+                                      addr      := Addr,
+                                      broadaddr := BAddr}} ->
+                                   ?SEV_IPRINT("local host info: "
+                                               "~n   Name:           ~p"
+                                               "~n   Addr:           ~p"
+                                               "~n   Broadcast Addr: ~p",
+                                               [Name, Addr, BAddr]),
+                                   LSA = #{family => Domain,
+                                           addr   => Addr},
+                                   BSA = #{family => Domain,
+                                           addr   => BAddr},
+                                   {ok, State#{lsa => LSA,
+                                               bsa => BSA}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "create TCP socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Get current value",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           case Get(Sock) of
+                               {ok, Val} when is_boolean(Val) ->
+                                   ?SEV_IPRINT("Success: ~p", [Val]),
+                                   {ok, State#{keepalive => Val}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Try change the value",
+           cmd  => fun(#{sock := Sock, keepalive := Current} = State) ->
+			   New = not Current,
+                           ?SEV_IPRINT("Try change value from ~p to ~p", 
+                                       [Current, New]),
+                           case Set(Sock, New) of
+                               ok ->
+                                   ?SEV_IPRINT("Expected Success"),
+                                   {ok, State#{keepalive => New}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected Failure: ~p",
+					       [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "Verify (new) current value",
+           cmd  => fun(#{sock := Sock, keepalive := Val} = _State) ->
+                           case Get(Sock) of
+                               {ok, Val} ->
+                                   ?SEV_IPRINT("Expected Success (~p)", [Val]),
+                                   ok;
+                               {ok, OtherVal} ->
+                                   ?SEV_IPRINT("Unexpected Success: ~p",
+                                               [OtherVal]),
+                                   {error, {unexpected_success_value,
+                                            Val, OtherVal}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected failure: ~p",
+                                               [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+         %% *** Termination ***
+         #{desc => "close UDP socket",
+           cmd  => fun(#{sock := Sock} = State0) ->
+                           socket:close(Sock),
+			   State1 = maps:remove(sock, State0),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    Domain = inet,
+
+    i("start tester evaluator"),
+    InitState = #{domain => Domain},
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests the socket option linger. PLACEHOLDER!
+
+api_opt_sock_linger(suite) ->
+    [];
+api_opt_sock_linger(doc) ->
+    [];
+api_opt_sock_linger(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_opt_sock_linger,
+           fun() -> not_yet_implemented() end,
+           fun() -> ok end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Tests that the add_mambership and drop_membership ip options work.
+%% We create one server and two clients. The server only send messages,
+%% the clients only receives messages.
+%% An UDP datagram is forbidden (RFC 1122) from having a source address
+%% that is a multicast address (or a broadcast address).
+%% So, the server create a socket "for sending" and the clients sockets
+%% "for receiving".
+%% Sending socket:   Bound to the local address (and any port).
+%%                   When sending, the dest will be the multicast address
+%%                   and port of the receiving socket.
+%% Receiving socket: Bound to the multicast address and port.
+api_opt_ip_add_drop_membership(suite) ->
+    [];
+api_opt_ip_add_drop_membership(doc) ->
+    ["OTP-15908 (ERL-980)"];
+api_opt_ip_add_drop_membership(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(api_opt_ip_add_drop_membership,
+           fun() ->
+                   has_support_ip_add_membership(),
+                   has_support_ip_drop_membership(),
+                   has_support_ip_multicast()
+           end,
+           fun() -> api_opt_ip_add_drop_membership() end).
+
+
+api_opt_ip_add_drop_membership() ->
+    Set = fun(S, Key, Val) ->
+                  socket:setopt(S, ip, Key, Val)
+          end,
+    AddMembership  = fun(S, Val) -> Set(S, add_membership,  Val) end,
+    DropMembership = fun(S, Val) -> Set(S, drop_membership, Val) end,
+
+    ServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, MSA} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, msa => MSA}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make recv socket reuse addr",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           case socket:setopt(Sock, socket, reuseaddr, true) of
+                               ok ->
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Failed set reuseaddr: "
+                                               "~n   ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind recv socket to multicast address",
+           cmd  => fun(#{sock := Sock, msa := MSA} = State) ->
+                           case socket:bind(Sock, MSA) of
+                               {ok, Port} ->
+                                   ?SEV_IPRINT("bound to:"
+                                               "~n   ~p", [Port]),
+                                   {ok, State#{msa => MSA#{port => Port}}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (add_membership)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, add_membership)
+                   end},
+         #{desc => "add membership",
+           cmd  => fun(#{sock     := Sock,
+                         msa      := #{addr := MAddr},
+                         local_sa := #{addr := Addr}} = State) ->
+                           MReq = #{multiaddr => MAddr,
+                                    interface => Addr},
+                           ?SEV_IPRINT("try add membership to:"
+                                       "~n   ~p", [MReq]),
+                           case AddMembership(Sock, MReq) of
+                               ok ->
+                                   ?SEV_IPRINT("membership added"),
+                                   {ok, State#{mreq => MReq}};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Failed adding membership to: "
+                                               "~n   ~p"
+                                               "~n   Reason:  ~p",
+                                               [MReq, Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (add-membership)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, add_membership),
+                           ok
+                   end},
+
+         #{desc => "await continue (drop_membership)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, drop_membership)
+                   end},
+         #{desc => "drop membership",
+           cmd  => fun(#{sock := Sock,
+                         mreq := MReq} = State) ->
+                           ?SEV_IPRINT("try drop membership from:"
+                                       "~n   ~p", [MReq]),
+                           case DropMembership(Sock, MReq) of
+                               ok ->
+                                   ?SEV_IPRINT("membership dropped"),
+                                   {ok, maps:remove(mreq, State)};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Failed drop membership from: "
+                                               "~n   ~p"
+                                               "~n   Reason:  ~p",
+                                               [MReq, Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (drop-membership)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, drop_membership),
+                           ok
+                   end},
+
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           socket:close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Server} = _State) ->
+                           _MRef = erlang:monitor(process, Server),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid, msa := MSA} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, MSA),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           case ?SEV_AWAIT_READY(Pid, server, init) of
+                               ok ->
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Start of server failed: "
+                                               "~n   ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** The actual test ***
+         #{desc => "order server to continue (add-membership)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, add_membership),
+                           ok
+                   end},
+         #{desc => "await server ready (add-membership)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, add_membership)
+                   end},
+
+         #{desc => "order server to continue (drop-membership)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, drop_membership),
+                           ok
+                   end},
+         #{desc => "await server ready (drop-membership)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, drop_membership)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         %% *** Termination ***
+         #{desc => "order server terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           {ok, maps:remove(server, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    Domain = inet,
+    i("get multicast address"),
+    MAddr  = which_ip_multicast_address(),
+    MSA    = #{family => Domain, addr => MAddr},
+
+    i("start server evaluator"),
+    ServerInitState = #{domain => Domain},
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start tester evaluator"),
+    TesterInitState = #{domain  => Domain,
+                        msa     => MSA,
+                        server  => Server#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Tester, Server]).
+
+
+
+which_ip_multicast_address() ->
+    which_multicast_address(inet).
+
+which_multicast_address(Domain) ->
+    case os:type() of
+        {unix, linux} ->
+            WhichMAddr = fun([_, _, MAddr]) -> MAddr end,
+            which_multicast_address2(Domain, WhichMAddr);
+
+        {unix, sunos} ->
+            WhichMAddr = fun([_, MAddr, _]) -> MAddr end,
+            which_multicast_address2(Domain, WhichMAddr);
+
+        Type ->
+            %% Actually, what is "not supported". is netstat!
+            not_supported({multicast, Type})
+    end.
+
+%% Note that the 'netstat -g' table looks different on linux and SunOS
+%% Linux: IfName - RefCnt - Group
+%% SunOS: IfName - Group  - RefCnt
+
+which_multicast_address2(Domain, WhichMAddr) ->
+    IfName = which_local_host_ifname(Domain),
+    %% On some platforms the netstat barfs out some crap on stderr
+    %% before the actual info...
+    case os:cmd("netstat -g 2>/dev/null | grep " ++ IfName) of
+        [] ->
+            %% Can't figure out if we support multicast or not...
+            not_supported(no_netstat);
+        NetstatGroupsStr ->
+            try
+                begin
+                    NetstatGroups0   = string:tokens(NetstatGroupsStr, [$\n]),
+                    NetstatGroups    = [string:tokens(G, [$ ]) || 
+                                           G <- NetstatGroups0],
+                    MAddrs           = [WhichMAddr(NetstatGroup) || 
+                                           NetstatGroup <- NetstatGroups],
+                    which_multicast_address3(Domain, MAddrs)
+                end
+            catch
+                throw:E:_ ->
+                    throw(E);
+                C:E:S ->
+                    not_supported({multicast, {C,E,S}})
+            end
+    end.
+
+which_multicast_address3(_Domain, []) ->
+    not_supported({multicast, no_valid_addrs});
+which_multicast_address3(Domain, [MAddrStr|MAddrs]) ->
+    %% Even on linux some of these are not actually addresses, but
+    %% "host names", such as all-systems.mcast.net. But both
+    %% address strings, such as "224.0.0.251" and host name strings
+    %% gets translated into an address by the inet:inet:getaddr/2.
+    case inet:getaddr(MAddrStr, Domain) of
+        {ok, MAddr} ->
+            MAddr;
+        {error, _} ->
+            which_multicast_address3(Domain, MAddrs)
+    end.
+    
+which_local_host_ifname(Domain) ->
+    case ?LIB:which_local_host_info(Domain) of
+        {ok, #{name := Name}} ->
+            Name;
+        {error, Reason} ->
+            not_supported({multicast, Reason})
+    end.
+
+    
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%                                                                     %%
+%%                  API OPERATIONS WITH TIMEOUT                        %%
+%%                                                                     %%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the connect timeout option
+%% on an IPv4 TCP (stream) socket.
+api_to_connect_tcp4(suite) ->
+    [];
+api_to_connect_tcp4(doc) ->
+    [];
+api_to_connect_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    Cond = fun() -> api_to_connect_cond() end,
+    tc_try(api_to_connect_tcp4,
+           Cond,
+           fun() ->
+                   InitState = #{domain        => inet,
+                                 backlog       => 1,
+                                 timeout       => 5000,
+                                 connect_limit => 3},
+                   ok = api_to_connect_tcp(InitState)
+           end).
+
+api_to_connect_cond() ->
+    api_to_connect_cond(os:type(), os:version()).
+
+%% I don't know exactly at which version this starts to work.
+%% I know it does not work for 4.4.*, but is does for 4.15.
+%% So, just to simplify, we require atleast 4.15
+api_to_connect_cond({unix, linux}, {Maj, Min, _Rev}) ->
+    if
+        (Maj > 4) ->
+            ok;
+        ((Maj =:= 4) andalso (Min >= 15)) ->
+            ok;
+        true ->
+            skip("TC does not work")
+    end;
+%% Only test on one machine, which has version 6.3, and there it does
+%% not work, so disable for all.
+api_to_connect_cond({unix, openbsd}, _) ->
+    skip("TC does not work");
+api_to_connect_cond({unix, freebsd}, {Maj, Min, _Rev}) ->
+    if
+        ((Maj >= 10) andalso (Min >= 4)) ->
+            ok;
+        true ->
+            skip("TC may not work")
+    end;
+api_to_connect_cond({unix, sunos}, {Maj, Min, _Rev}) ->
+    if
+        ((Maj >= 5) andalso (Min >= 10)) ->
+            ok;
+        true ->
+            skip("TC may not work")
+    end;
+api_to_connect_cond(_, _) ->
+    skip("TC may not work").
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the connect timeout option
+%% on an IPv6 TCP (stream) socket.
+api_to_connect_tcp6(suite) ->
+    [];
+api_to_connect_tcp6(doc) ->
+    [];
+api_to_connect_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_connect_tcp6,
+           fun() -> has_support_ipv6(), api_to_connect_cond() end,
+           fun() ->
+                   InitState = #{domain        => inet6,
+                                 backlog       => 1,
+                                 timeout       => 5000,
+                                 connect_limit => 3},
+                   ok = api_to_connect_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% We use the backlog (listen) argument to test this.
+%% Note that the behaviour of the TCP "server side" can vary when 
+%% a client connect to a "busy" server (full backlog).
+%% For instance, on FreeBSD (11.2) the reponse when the backlog is full
+%% is a econreset.
+
+api_to_connect_tcp(InitState) ->
+    process_flag(trap_exit, true),
+
+    ServerSeq = 
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           {Tester, Backlog} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester  => Tester,
+                                       backlog => Backlog}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, local_sa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket (with backlog = 1)",
+           cmd  => fun(#{lsock := LSock, backlog := Backlog}) ->
+                           socket:listen(LSock, Backlog)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, lport := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{lsock := Sock} = State) ->
+                           sock_close(Sock),
+                           State1 = maps:remove(lport, State),
+                           State2 = maps:remove(sock,  State1),
+                           {ok, State2}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, ServerSA} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester    => Tester,
+                                       server_sa => ServerSA}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create node",
+           cmd  => fun(#{host := Host} = State) ->
+			   ?SEV_IPRINT("try create node on ~p", [Host]),
+                           case start_node(Host, client) of
+                               {ok, Node} ->
+                                   ?SEV_IPRINT("client node ~p started",
+                                               [Node]),
+                                   {ok, State#{node => Node}};
+                               {error, Reason} ->
+                                   {skip, Reason}
+                           end
+                   end},
+         #{desc => "monitor client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           true = erlang:monitor_node(Node, true),
+                           ok
+                   end},
+         #{desc => "start remote client on client node",
+           cmd  => fun(#{node := Node} = State) ->
+                           Pid = api_toc_tcp_client_start(Node),
+                           ?SEV_IPRINT("remote client ~p started", [Pid]),
+                           {ok, State#{rclient => Pid}}
+                   end},
+         #{desc => "monitor remote client",
+           cmd  => fun(#{rclient := Pid}) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "order remote client to start",
+           cmd  => fun(#{rclient   := Client,
+                         server_sa := ServerSA}) ->
+                           ?SEV_ANNOUNCE_START(Client, ServerSA),
+                           ok
+                   end},
+         #{desc => "await remote client ready",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, init,
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, connect,
+                                                    [{rclient, Client}]) of
+                               {ok, {ConTimeout, ConLimit}} ->
+                                   {ok, State#{connect_timeout => ConTimeout,
+                                               connect_limit   => ConLimit}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (connect)",
+           cmd  => fun(#{rclient         := RClient,
+                         connect_timeout := ConTimeout,
+                         connect_limit   := ConLimit}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(RClient, connect,
+                                                  {ConTimeout, ConLimit}),
+                           ok
+                   end},
+         #{desc => "await remote client ready (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := RClient} = State) ->
+                           case ?SEV_AWAIT_READY(RClient, rclient, connect,
+                                                 [{tester, Tester}]) of
+                               {ok, ok = _Result} ->
+                                   {ok, maps:remove(connect_limit, State)};
+                               {ok, {error, {connect_limit_reached,R,L}}} ->
+                                   {skip,
+                                    ?LIB:f("Connect limit reached ~w: ~w",
+                                           [L, R])};
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := RClient} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester,
+                                                     [{rclient, RClient}]) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "kill remote client",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await remote client termination",
+           cmd  => fun(#{rclient := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(rclient, State),
+                           {ok, State1}
+                   end},
+         #{desc => "stop client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           stop_node(Node)
+                   end},
+         #{desc => "await client node termination",
+           cmd  => fun(#{node := Node} = State) ->
+                           receive
+                               {nodedown, Node} ->
+                                   State1 = maps:remove(node_id, State),
+                                   State2 = maps:remove(node,    State1),
+                                   {ok, State2}
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Server} = _State) ->
+                           _MRef = erlang:monitor(process, Server),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Client} = _State) ->
+                           _MRef = erlang:monitor(process, Client),
+                           ok
+                   end},
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "order server start",
+           cmd  => fun(#{server  := Server,
+                         backlog := Backlog}) ->
+                           ?SEV_ANNOUNCE_START(Server, Backlog),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Server, local_sa := LSA} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Server, server, init),
+                           ServerSA = LSA#{port => Port},
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+         #{desc => "order client start",
+           cmd  => fun(#{client    := Client,
+                         server_sa := ServerSA}) ->
+                           ?SEV_ANNOUNCE_START(Client, ServerSA),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, init),
+                           ok
+                   end},
+
+         %% The actual test
+         %% The server does nothing (this is the point), no accept,
+         %% the client tries to connect.
+         #{desc => "order client continue (connect)",
+           cmd  => fun(#{client        := Client,
+                         timeout       := Timeout,
+                         connect_limit := ConLimit} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, connect,
+                                                  {Timeout, ConLimit}),
+                           ok
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, client, connect,
+                                                 [{server, Server}]) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** Terminate server ***
+         #{desc => "order client terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client down",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client,    State),
+                           {ok, State1}
+                   end},
+         #{desc => "order server terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server down",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server,    State),
+                           State2 = maps:remove(server_sa, State1),
+                           {ok, State2}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("create server evaluator"),
+    ServerInitState = #{domain => maps:get(domain, InitState)},
+    Server          = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("create client evaluator"),
+    ClientInitState = #{host   => local_host(),
+                        domain => maps:get(domain, InitState)},
+    Client          = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("create tester evaluator"),
+    TesterInitState = InitState#{server => Server#ev.pid,
+                                 client => Client#ev.pid},
+    Tester          = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+api_toc_tcp_client_start(Node) ->
+    Self = self(),
+    Fun  = fun() -> api_toc_tcp_client(Self) end,
+    erlang:spawn(Node, Fun).
+
+api_toc_tcp_client(Parent) ->
+    api_toc_tcp_client_init(Parent),
+    ServerSA = api_toc_tcp_client_await_start(Parent),
+    Domain   = maps:get(family, ServerSA),
+    api_toc_tcp_client_announce_ready(Parent, init),
+    {To, ConLimit} = api_toc_tcp_client_await_continue(Parent, connect),
+    Result = api_to_connect_tcp_await_timeout(To, ServerSA, Domain, ConLimit),
+    ?SEV_IPRINT("result: ~p", [Result]),
+    api_toc_tcp_client_announce_ready(Parent, connect, Result),
+    Reason = api_toc_tcp_client_await_terminate(Parent),
+    exit(Reason).
+
+api_toc_tcp_client_init(Parent) ->
+    put(sname, "rclient"),
+    %% i("api_toc_tcp_client_init -> entry"),
+    _MRef = erlang:monitor(process, Parent),
+    ok.
+
+api_toc_tcp_client_await_start(Parent) ->
+    %% i("api_toc_tcp_client_await_start -> entry"),
+    ?SEV_AWAIT_START(Parent).
+
+api_toc_tcp_client_announce_ready(Parent, Slogan) ->
+    ?SEV_ANNOUNCE_READY(Parent, Slogan).
+api_toc_tcp_client_announce_ready(Parent, Slogan, Result) ->
+    ?SEV_ANNOUNCE_READY(Parent, Slogan, Result).
+
+api_toc_tcp_client_await_continue(Parent, Slogan) ->
+    %% i("api_toc_tcp_client_await_continue -> entry"),
+    case ?SEV_AWAIT_CONTINUE(Parent, parent, Slogan) of
+        ok ->
+            ok;
+        {ok, Extra} ->
+            Extra;
+        {error, Reason} ->
+            exit({await_continue, Slogan, Reason})
+    end.
+
+api_toc_tcp_client_await_terminate(Parent) ->
+    %% i("api_toc_tcp_client_await_terminate -> entry"),
+    case ?SEV_AWAIT_TERMINATE(Parent, parent) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            Reason
+    end.
+
+api_to_connect_tcp_await_timeout(To, ServerSA, Domain, ConLimit) ->
+    LSA = which_local_socket_addr(Domain),
+    NewSock = fun() ->
+                      S = case socket:open(Domain, stream, tcp) of
+                              {ok, Sock} ->
+                                  Sock;
+                              {error, OReason} ->
+                                  ?FAIL({open, OReason})
+                          end,
+                      case socket:bind(S, LSA) of
+                          {ok, _} ->
+                              S;
+                          {error, BReason} ->
+                              ?FAIL({bind, BReason})
+                      end
+              end,
+    api_to_connect_tcp_await_timeout(1, ConLimit, To, ServerSA, NewSock, []).
+
+api_to_connect_tcp_await_timeout(ID, ConLimit, _To, _ServerSA, _NewSock, Acc)
+  when (ID > ConLimit) ->
+    api_to_connect_tcp_await_timeout3(Acc),
+    {error, {connect_limit_reached, ID, ConLimit}};
+api_to_connect_tcp_await_timeout(ID, ConLimit, To, ServerSA, NewSock, Acc) ->
+    case api_to_connect_tcp_await_timeout2(ID, To, ServerSA, NewSock) of
+        ok ->
+            %% ?SEV_IPRINT("success when number of socks: ~w", [length(Acc)]),
+            api_to_connect_tcp_await_timeout3(Acc),
+            ok;
+        {ok, Sock} ->
+            %% ?SEV_IPRINT("~w: unexpected success (connect)", [ID]),
+            api_to_connect_tcp_await_timeout(ID+1, ConLimit,
+                                             To, ServerSA, NewSock,
+                                             [Sock|Acc]);
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+api_to_connect_tcp_await_timeout2(_ID, To, ServerSA, NewSock) ->
+    Sock = NewSock(),
+    %% ?SEV_IPRINT("~w: try connect", [ID]),
+    Start = t(),
+    case socket:connect(Sock, ServerSA, To) of
+        {error, timeout} ->
+            Stop  = t(),
+            TDiff = Stop - Start,
+            if
+                (TDiff >= To) ->
+                    (catch socket:close(Sock)),
+                    ok;
+                true ->
+                    (catch socket:close(Sock)),
+                    ?FAIL({unexpected_timeout, TDiff, To})
+            end;
+        {error, econnreset = _Reason} ->
+            (catch socket:close(Sock)),
+            ok;
+        {error, Reason} ->
+            (catch socket:close(Sock)),
+            ?FAIL({connect, Reason});
+        ok ->
+            {ok, Sock}
+    end.
+
+api_to_connect_tcp_await_timeout3([]) ->
+    ok;
+api_to_connect_tcp_await_timeout3([Sock|Socka]) ->
+    (catch socket:close(Sock)),
+    api_to_connect_tcp_await_timeout3(Socka).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the accept timeout option
+%% on an IPv4 TCP (stream) socket.
+api_to_accept_tcp4(suite) ->
+    [];
+api_to_accept_tcp4(doc) ->
+    [];
+api_to_accept_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_accept_tcp4,
+           fun() ->
+                   InitState = #{domain => inet, timeout => 5000},
+                   ok = api_to_accept_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the accept timeout option
+%% on an IPv6 TCP (stream) socket.
+api_to_accept_tcp6(suite) ->
+    [];
+api_to_accept_tcp6(doc) ->
+    [];
+api_to_accept_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_accept_tcp4,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain => inet6, timeout => 5000},
+                   ok = api_to_accept_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_to_accept_tcp(InitState) ->
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create (listen) socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, lsa := LSA} = _State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, _} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+
+         %% *** The actual test part ***
+         #{desc => "attempt to accept (without success)",
+           cmd  => fun(#{lsock := LSock, timeout := To} = State) ->
+                           Start = t(),
+                           case socket:accept(LSock, To) of
+                               {error, timeout} ->
+                                   {ok, State#{start => Start, stop => t()}};
+                               {ok, Sock} ->
+                                   (catch socket:close(Sock)),
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate timeout time",
+           cmd  => fun(#{start := Start, stop := Stop, timeout := To} = _State) ->
+                           TDiff  = Stop - Start,
+                           if
+                               (TDiff >= To) ->
+                                   ok;
+                               true ->
+                                   {error, {unexpected_timeout, TDiff, To}}
+                           end
+                   end},
+
+         %% *** Close (listen) socket ***
+         #{desc => "close (listen) socket",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           sock_close(LSock),
+                           {ok, maps:remove(sock3, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("create tester evaluator"),
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the multi accept timeout option
+%% on an IPv4 TCP (stream) socket with multiple acceptor processes 
+%% (three in this case).
+api_to_maccept_tcp4(suite) ->
+    [];
+api_to_maccept_tcp4(doc) ->
+    [];
+api_to_maccept_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_to_maccept_tcp4,
+           fun() ->
+                   InitState = #{domain => inet, timeout => 5000},
+                   ok = api_to_maccept_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the accept timeout option
+%% on an IPv6 TCP (stream) socket.
+api_to_maccept_tcp6(suite) ->
+    [];
+api_to_maccept_tcp6(doc) ->
+    [];
+api_to_maccept_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(20)),
+    tc_try(api_to_maccept_tcp4,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain => inet6, timeout => 5000},
+                   ok = api_to_maccept_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_to_maccept_tcp(InitState) ->
+    PrimAcceptorSeq =
+        [
+         %% *** Init part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create (listen) socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, lsa := LSA} = _State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, _} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{lsock := LSock, tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, LSock),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "attempt to accept (without success)",
+           cmd  => fun(#{lsock := LSock, timeout := To} = State) ->
+                           Start = t(),
+                           case socket:accept(LSock, To) of
+                               {error, timeout} ->
+                                   {ok, State#{start => Start, stop => t()}};
+                               {ok, Sock} ->
+                                   ?SEV_EPRINT("Unexpected accept success: "
+                                               "~n   ~p", [Sock]),
+                                   (catch socket:close(Sock)),
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate timeout time",
+           cmd  => fun(#{start := Start, stop := Stop, timeout := To} = _State) ->
+                           TDiff  = Stop - Start,
+                           if
+                               (TDiff >= To) ->
+                                   ok;
+                               true ->
+                                   {error, {unexpected_timeout, TDiff, To}}
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+
+         %% *** Terminate ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_TERMINATE(Tester, tester),
+                           ok
+                   end},
+         %% *** Close (listen) socket ***
+         #{desc => "close (listen) socket",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           sock_close(LSock),
+                           {ok, maps:remove(lsock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    SecAcceptorSeq =
+        [
+         %% *** Init part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, LSock} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester,
+                                       lsock  => LSock}}
+                           
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% *** The actual test part ***
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "attempt to accept (without success)",
+           cmd  => fun(#{lsock := LSock, timeout := To} = State) ->
+                           Start = t(),
+                           case socket:accept(LSock, To) of
+                               {error, timeout} ->
+                                   {ok, State#{start => Start, stop => t()}};
+                               {ok, Sock} ->
+                                   (catch socket:close(Sock)),
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate timeout time",
+           cmd  => fun(#{start := Start, stop := Stop, timeout := To} = State) ->
+                           TDiff  = Stop - Start,
+                           if
+                               (TDiff >= To) ->
+                                   State1 = maps:remove(start, State),
+                                   State2 = maps:remove(stop,  State1),
+                                   {ok, State2};
+                               true ->
+                                   {error, {unexpected_timeout, TDiff, To}}
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+
+         %% *** Terminate ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq =
+        [
+         %% Init part
+         #{desc => "monitor prim-acceptor",
+           cmd  => fun(#{prim_acceptor := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor sec-acceptor 1",
+           cmd  => fun(#{sec_acceptor1 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor sec-acceptor 2",
+           cmd  => fun(#{sec_acceptor2 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+
+         %% Start the prim-acceptor
+         #{desc => "start prim-acceptor",
+           cmd  => fun(#{prim_acceptor := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await prim-acceptor ready (init)",
+           cmd  => fun(#{prim_acceptor := Pid} = State) ->
+                           {ok, Sock} = ?SEV_AWAIT_READY(Pid, prim_acceptor, init),
+                           {ok, State#{lsock => Sock}}
+                   end},
+
+         %% Start sec-acceptor-1
+         #{desc => "start sec-acceptor 1",
+           cmd  => fun(#{sec_acceptor1 := Pid, lsock := LSock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, LSock),
+                           ok
+                   end},
+         #{desc => "await sec-acceptor 1 ready (init)",
+           cmd  => fun(#{sec_acceptor1 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, sec_acceptor1, init)
+                   end},
+
+         %% Start sec-acceptor-2
+         #{desc => "start sec-acceptor 2",
+           cmd  => fun(#{sec_acceptor2 := Pid, lsock := LSock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, LSock),
+                           ok
+                   end},
+         #{desc => "await sec-acceptor 2 ready (init)",
+           cmd  => fun(#{sec_acceptor2 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, sec_acceptor2, init)
+                   end},
+
+         %% Activate the acceptor(s)
+         #{desc => "active prim-acceptor",
+           cmd  => fun(#{prim_acceptor := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         #{desc => "active sec-acceptor 1",
+           cmd  => fun(#{sec_acceptor1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         #{desc => "active sec-acceptor 2",
+           cmd  => fun(#{sec_acceptor2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+
+         %% Await acceptor(s) completions
+         #{desc => "await prim-acceptor ready (accept)",
+           cmd  => fun(#{prim_acceptor := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, prim_acceptor, accept)
+                   end},
+         #{desc => "await sec-acceptor 1 ready (accept)",
+           cmd  => fun(#{sec_acceptor1 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, sec_acceptor1, accept)
+                   end},
+         #{desc => "await sec-acceptor 2 ready (accept)",
+           cmd  => fun(#{sec_acceptor2 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, sec_acceptor2, accept)
+                   end},
+
+         %% Terminate
+         #{desc => "order prim-acceptor to terminate",
+           cmd  => fun(#{prim_acceptor := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await prim-acceptor termination",
+           cmd  => fun(#{prim_acceptor := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(prim_acceptor, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order sec-acceptor 1 to terminate",
+           cmd  => fun(#{sec_acceptor1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await sec-acceptor 1 termination",
+           cmd  => fun(#{sec_acceptor1 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(sec_acceptor1, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order sec-acceptor 2 to terminate",
+           cmd  => fun(#{sec_acceptor2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await sec-acceptor 2 termination",
+           cmd  => fun(#{sec_acceptor2 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(sec_acceptor2, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("create prim-acceptor evaluator"),
+    PrimAInitState = InitState,
+    PrimAcceptor = ?SEV_START("prim-acceptor", PrimAcceptorSeq, PrimAInitState),
+
+    i("create sec-acceptor 1 evaluator"),
+    SecAInitState1 = maps:remove(domain, InitState),
+    SecAcceptor1 = ?SEV_START("sec-acceptor-1", SecAcceptorSeq, SecAInitState1),
+    
+    i("create sec-acceptor 2 evaluator"),
+    SecAInitState2 = SecAInitState1,
+    SecAcceptor2 = ?SEV_START("sec-acceptor-2", SecAcceptorSeq, SecAInitState2),
+
+    i("create tester evaluator"),
+    TesterInitState = #{prim_acceptor => PrimAcceptor#ev.pid,
+                        sec_acceptor1 => SecAcceptor1#ev.pid,
+                        sec_acceptor2 => SecAcceptor2#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([PrimAcceptor, SecAcceptor1, SecAcceptor2, Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the send timeout option
+%% on an IPv4 TCP (stream) socket.
+api_to_send_tcp4(suite) ->
+    [];
+api_to_send_tcp4(doc) ->
+    [];
+api_to_send_tcp4(_Config) when is_list(_Config) ->
+    tc_try(api_to_send_tcp4,
+           fun() ->
+                   not_yet_implemented()%% ,
+                   %% ok = api_to_send_tcp(inet)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the send timeout option
+%% on an IPv6 TCP (stream) socket.
+api_to_send_tcp6(suite) ->
+    [];
+api_to_send_tcp6(doc) ->
+    [];
+api_to_send_tcp6(_Config) when is_list(_Config) ->
+    tc_try(api_to_send_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   not_yet_implemented()%% ,
+                   %% ok = api_to_send_tcp(inet6)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the sendto timeout option
+%% on an IPv4 UDP (dgram) socket.
+api_to_sendto_udp4(suite) ->
+    [];
+api_to_sendto_udp4(doc) ->
+    [];
+api_to_sendto_udp4(_Config) when is_list(_Config) ->
+    tc_try(api_to_sendto_udp4,
+           fun() ->
+                   not_yet_implemented()%% ,
+                   %% ok = api_to_sendto_to_udp(inet)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the sendto timeout option
+%% on an IPv6 UDP (dgram) socket.
+api_to_sendto_udp6(suite) ->
+    [];
+api_to_sendto_udp6(doc) ->
+    [];
+api_to_sendto_udp6(_Config) when is_list(_Config) ->
+    tc_try(api_to_sendto_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   not_yet_implemented()%% ,
+                   %% ok = api_to_sendto_to_udp(inet6)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the sendmsg timeout option
+%% on an IPv4 TCP (stream) socket.
+api_to_sendmsg_tcp4(suite) ->
+    [];
+api_to_sendmsg_tcp4(doc) ->
+    [];
+api_to_sendmsg_tcp4(_Config) when is_list(_Config) ->
+    tc_try(api_to_sendmsg_tcp4,
+           fun() ->
+                   not_yet_implemented()%% ,
+                   %% ok = api_to_sendmsg_tcp(inet)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the sendmsg timeout option
+%% on an IPv6 TCP (stream) socket.
+api_to_sendmsg_tcp6(suite) ->
+    [];
+api_to_sendmsg_tcp6(doc) ->
+    [];
+api_to_sendmsg_tcp6(_Config) when is_list(_Config) ->
+    tc_try(api_to_sendmsg_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   not_yet_implemented()%% ,
+                   %% ok = api_to_sendmsg_tcp(inet6)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recv timeout option
+%% on an IPv4 UDP (dgram) socket. To test this we must connect
+%% the socket.
+api_to_recv_udp4(suite) ->
+    [];
+api_to_recv_udp4(doc) ->
+    [];
+api_to_recv_udp4(_Config) when is_list(_Config) ->
+    tc_try(api_to_recv_udp4,
+           fun() ->
+                   not_yet_implemented()%%,
+                   %%ok = api_to_recv_udp(inet)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recv timeout option
+%% on an IPv6 UDP (dgram) socket. To test this we must connect
+%% the socket.
+api_to_recv_udp6(suite) ->
+    [];
+api_to_recv_udp6(doc) ->
+    [];
+api_to_recv_udp6(_Config) when is_list(_Config) ->
+    tc_try(api_to_recv_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   not_yet_implemented()%% ,
+                   %% ok = api_to_recv_udp(inet6)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recv timeout option
+%% on an IPv4 TCP (stream) socket.
+api_to_recv_tcp4(suite) ->
+    [];
+api_to_recv_tcp4(doc) ->
+    [];
+api_to_recv_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_recv_tcp4,
+           fun() ->
+                   Recv = fun(Sock, To) -> socket:recv(Sock, 0, To) end,
+                   InitState = #{domain  => inet,
+                                 recv    => Recv,
+                                 timeout => 2000},
+                   ok = api_to_receive_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recv timeout option
+%% on an IPv6 TCP (stream) socket.
+api_to_recv_tcp6(suite) ->
+    [];
+api_to_recv_tcp6(doc) ->
+    [];
+api_to_recv_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_recv_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   case socket:supports(ipv6) of
+                       true ->
+                           Recv = fun(Sock, To) -> 
+                                          socket:recv(Sock, 0, To)
+                                  end,
+                           InitState = #{domain  => inet6,
+                                         recv    => Recv,
+                                         timeout => 2000},
+                           ok = api_to_receive_tcp(InitState);
+                       false ->
+                           skip("ipv6 not supported")
+                   end
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_to_receive_tcp(InitState) ->
+    process_flag(trap_exit, true),
+
+    ServerSeq = 
+        [
+         %% *** Wait for start order ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester}) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{lsock := LSock, local_sa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket (with backlog = 1)",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock, 1)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, lport := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "await continue (accept and recv)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept_recv)
+                   end},
+         #{desc => "attempt accept",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "attempt to recv (without success)",
+           cmd  => fun(#{sock := Sock, recv := Recv, timeout := To} = State) ->
+                           Start = t(),
+                           case Recv(Sock, To) of
+                               {error, timeout} ->
+                                   {ok, State#{start => Start, stop => t()}};
+                               {ok, _Data} ->
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate timeout time",
+           cmd  => fun(#{start := Start, stop := Stop, timeout := To} = State) ->
+                           TDiff  = Stop - Start,
+                           if
+                               (TDiff >= To) ->
+                                   State1 = maps:remove(start, State),
+                                   State2 = maps:remove(stop,  State1),
+                                   {ok, State2};
+                               true ->
+                                   {error, {unexpected_timeout, TDiff, To}}
+                           end
+                   end},
+         #{desc => "announce ready (recv timeout success)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept_recv),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close (traffic) socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           sock_close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+         #{desc => "close (listen) socket",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           sock_close(LSock),
+                           {ok, maps:remove(lsock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           {Tester, Port} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester      => Tester,
+                                       server_port => Port}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain, server_port := Port} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = LSA#{port => Port},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, stream, tcp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "await continue (with connect)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect)
+                   end},
+         #{desc => "connect",
+           cmd  => fun(#{sock := Sock, server_sa := SSA}) ->
+                           sock_connect(Sock, SSA),
+                           ok
+                   end},
+
+         %% *** Termination ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           sock_close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Server} = _State) ->
+                           _MRef = erlang:monitor(process, Server),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Client} = _State) ->
+                           _MRef = erlang:monitor(process, Client),
+                           ok
+                   end},
+
+         %% *** Activate server ***
+         #{desc => "start server",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_START(Server),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Server} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Server, server, init),
+                           {ok, State#{server_port => Port}}
+                   end},
+         #{desc => "order server to continue (with accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, accept_recv),
+                           ok
+                   end},
+
+         %% *** Activate client ***
+         #{desc => "start client",
+           cmd  => fun(#{client := Client, server_port := Port} = _State) ->
+                           ?SEV_ANNOUNCE_START(Client, Port),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, init)
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "order client to continue (with connect)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, connect),
+                           ok
+                   end},
+         #{desc => "await server ready (accept/recv)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, accept_recv)
+                   end},
+
+         %% *** Termination ***
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Client} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Client) of
+                               ok ->
+                                   State1 = maps:remove(client, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Server) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   State2 = maps:remove(server_port, State1),
+                                   {ok, State2};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    
+    i("start server evaluator"),
+    ServerInitState = InitState,
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator"),
+    ClientInitState = InitState,
+    Client = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("start tester evaluator"),
+    TesterInitState = #{server => Server#ev.pid, 
+                        client => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recvfrom timeout option
+%% on an IPv4 UDP (dgram) socket.
+api_to_recvfrom_udp4(suite) ->
+    [];
+api_to_recvfrom_udp4(doc) ->
+    [];
+api_to_recvfrom_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_recvfrom_udp4,
+           fun() ->
+                   Recv = fun(Sock, To) -> socket:recvfrom(Sock, 0, To) end,
+                   InitState = #{domain  => inet,
+                                 recv    => Recv,
+                                 timeout => 2000},
+                   ok = api_to_receive_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recvfrom timeout option
+%% on an IPv6 UDP (dgram) socket.
+api_to_recvfrom_udp6(suite) ->
+    [];
+api_to_recvfrom_udp6(doc) ->
+    [];
+api_to_recvfrom_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_recvfrom_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock, To) -> socket:recvfrom(Sock, 0, To) end,
+                   InitState = #{domain  => inet6,
+                                 recv    => Recv,
+                                 timeout => 2000},
+                   ok = api_to_receive_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_to_receive_udp(InitState) ->
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, lsa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** The actual test ***
+         #{desc => "attempt to read (without success)",
+           cmd  => fun(#{sock := Sock, recv := Recv, timeout := To} = State) ->
+                           Start = t(),
+                           case Recv(Sock, To) of
+                               {error, timeout} ->
+                                   {ok, State#{start => Start,
+                                               stop => t()}};
+                               {ok, _} ->
+                                   {error, unexpected_sucsess};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate timeout time",
+           cmd  => fun(#{start := Start, stop := Stop, timeout := To} = _State) ->
+                           TDiff  = Stop - Start,
+                           if
+                               (TDiff >= To) ->
+                                   ok;
+                               true ->
+                                   {error, {unexpected_timeout, TDiff, To}}
+                           end
+                   end},
+         
+         %% *** Termination ***
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           %% socket:setopt(Sock, otp, debug, true),
+                           sock_close(Sock),
+                           ok
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start tester evaluator"),
+    Tester = ?SEV_START("tester", TesterSeq, InitState),
+    
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recvmsg timeout option
+%% on an IPv4 UDP (dgram) socket.
+api_to_recvmsg_udp4(suite) ->
+    [];
+api_to_recvmsg_udp4(doc) ->
+    [];
+api_to_recvmsg_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_recvmsg_udp4,
+           fun() ->
+                   Recv = fun(Sock, To) -> socket:recvmsg(Sock, To) end,
+                   InitState = #{domain  => inet,
+                                 recv    => Recv,
+                                 timeout => 2000},
+                   ok = api_to_receive_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recvmsg timeout option
+%% on an IPv6 UDP (dgram) socket.
+api_to_recvmsg_udp6(suite) ->
+    [];
+api_to_recvmsg_udp6(doc) ->
+    [];
+api_to_recvmsg_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_recvmsg_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock, To) -> socket:recvmsg(Sock, To) end,
+                   InitState = #{domain  => inet6,
+                                 recv    => Recv,
+                                 timeout => 2000},
+                   ok = api_to_receive_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recvmsg timeout option
+%% on an IPv4 TCP (stream) socket.
+api_to_recvmsg_tcp4(suite) ->
+    [];
+api_to_recvmsg_tcp4(doc) ->
+    [];
+api_to_recvmsg_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_recvmsg_tcp4,
+           fun() ->
+                   Recv = fun(Sock, To) -> socket:recvmsg(Sock, To) end,
+                   InitState = #{domain  => inet,
+                                 recv    => Recv,
+                                 timeout => 2000},
+                   ok = api_to_receive_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This test case is intended to test the recvmsg timeout option
+%% on an IPv6 TCP (stream) socket.
+api_to_recvmsg_tcp6(suite) ->
+    [];
+api_to_recvmsg_tcp6(doc) ->
+    [];
+api_to_recvmsg_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(api_to_recvmsg_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv = fun(Sock, To) -> socket:recvmsg(Sock, To) end,
+                   InitState = #{domain  => inet6,
+                                 recv    => Recv,
+                                 timeout => 2000},
+                   ok = api_to_receive_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%                                                                     %%
+%%                         SOCKET CLOSURE                              %%
+%%                                                                     %%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sockets are cleaned up
+%% ("removed") when the controlling process terminates (without explicitly 
+%% calling the close function). For a IPv4 TCP (stream) socket.
+
+sc_cpe_socket_cleanup_tcp4(suite) ->
+    [];
+sc_cpe_socket_cleanup_tcp4(doc) ->
+    [];
+sc_cpe_socket_cleanup_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_cpe_socket_cleanup_tcp4,
+           fun() ->
+                   InitState = #{domain   => inet,
+                                 type     => stream,
+                                 protocol => tcp},
+                   ok = sc_cpe_socket_cleanup(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sockets are cleaned up
+%% ("removed") when the controlling process terminates (without explicitly 
+%% calling the close function). For a IPv6 TCP (stream) socket.
+
+sc_cpe_socket_cleanup_tcp6(suite) ->
+    [];
+sc_cpe_socket_cleanup_tcp6(doc) ->
+    [];
+sc_cpe_socket_cleanup_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_cpe_socket_cleanup_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain   => inet6,
+                                 type     => stream,
+                                 protocol => tcp},
+                   ok = sc_cpe_socket_cleanup(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sockets are cleaned up
+%% ("removed") when the controlling process terminates (without explicitly 
+%% calling the close function). For a Unix Domain (stream) socket (TCP).
+
+sc_cpe_socket_cleanup_tcpL(suite) ->
+    [];
+sc_cpe_socket_cleanup_tcpL(doc) ->
+    [];
+sc_cpe_socket_cleanup_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_cpe_socket_cleanup_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain   => local,
+                                 type     => stream,
+                                 protocol => default},
+                   ok = sc_cpe_socket_cleanup(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sockets are cleaned up
+%% ("removed") when the controlling process terminates (without explicitly 
+%% calling the close function). For a IPv4 UDP (dgram) socket.
+
+sc_cpe_socket_cleanup_udp4(suite) ->
+    [];
+sc_cpe_socket_cleanup_udp4(doc) ->
+    [];
+sc_cpe_socket_cleanup_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_cpe_socket_cleanup_udp4,
+           fun() ->
+                   InitState = #{domain   => inet,
+                                 type     => dgram,
+                                 protocol => udp},
+                   ok = sc_cpe_socket_cleanup(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sockets are cleaned up
+%% (removed) when the controlling process terminates (without explicitly 
+%% calling the close function). For a IPv6 UDP (dgram) socket.
+
+sc_cpe_socket_cleanup_udp6(suite) ->
+    [];
+sc_cpe_socket_cleanup_udp6(doc) ->
+    [];
+sc_cpe_socket_cleanup_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_cpe_socket_cleanup_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain   => inet6,
+                                 type     => dgram,
+                                 protocol => udp},
+                   ok = sc_cpe_socket_cleanup(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sockets are cleaned up
+%% ("removed") when the controlling process terminates (without explicitly 
+%% calling the close function). For a Unix Domain (dgram) socket (UDP).
+
+sc_cpe_socket_cleanup_udpL(suite) ->
+    [];
+sc_cpe_socket_cleanup_udpL(doc) ->
+    [];
+sc_cpe_socket_cleanup_udpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_cpe_socket_cleanup_udpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain   => local,
+                                 type     => dgram,
+                                 protocol => default},
+                   ok = sc_cpe_socket_cleanup(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+sc_cpe_socket_cleanup(InitState) ->
+    OwnerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "create socket",
+           cmd  => fun(#{domain   := Domain, 
+                         type     := Type, 
+                         protocol := Proto} = State) ->
+                           case socket:open(Domain, Type, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Sock),
+                           ok
+                   end},
+
+         %% *** The actual test ***
+         %% We *intentially* leave the socket "as is", no explicit close
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor owner",
+           cmd  => fun(#{owner := Owner} = _State) ->
+                           _MRef = erlang:monitor(process, Owner),
+                           ok
+                   end},
+         #{desc => "order (owner) start",
+           cmd  => fun(#{owner := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await (owner) ready",
+           cmd  => fun(#{owner := Pid} = State) ->
+                           {ok, Sock} = ?SEV_AWAIT_READY(Pid, owner, init),
+                           {ok, State#{sock => Sock}}
+                   end},
+         #{desc => "verify owner as controlling-process",
+           cmd  => fun(#{owner := Pid, sock := Sock} = _State) ->
+                           case socket:getopt(Sock, otp, controlling_process) of
+                               {ok, Pid} ->
+                                   ok;
+                               {ok, Other} ->
+                                   {error, {unexpected_owner, Other}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order (owner) terminate",
+           cmd  => fun(#{owner := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await (owner) termination",
+           cmd  => fun(#{owner := Pid} = _State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         ?SEV_SLEEP(?SECS(5)),
+
+         %% The reason we get closed, is that as long as there is a ref to 
+         %% the resource (socket), then it will not be garbage collected.
+         %% Note that its still a race that the nif has processed that the
+         %% "controlling process" has terminated. There really is no 
+         %% proper timeout for this, but the 5 seconds "should" be enough...
+         %% We should really have some way to subscribe to socket events...
+         #{desc => "verify no socket (closed)",
+           cmd  => fun(#{owner := Pid, sock := Sock} = _State) ->
+                           case socket:getopt(Sock, otp, controlling_process) of
+                               {ok, OtherPid} ->
+                                   {error, {unexpected_success, Pid, OtherPid}};
+                               {error, closed} ->
+                                   ok;
+                               {error, Reason} ->
+                                   ?SEV_IPRINT("expected failure: ~p", [Reason]),
+                                   {error, {unexpected_failure, Reason}}
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start (socket) owner evaluator"),
+    Owner = ?SEV_START("owner", OwnerSeq, InitState),
+
+    i("start tester evaluator"),
+    TesterInitState = #{owner => Owner#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Owner, Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while a process is calling the recv function.
+%% Socket is IPv4.
+%% 
+%% <KOLLA>
+%% 
+%% We should really have a similar test cases for when the controlling
+%% process exits and there are other processes in recv, accept, and 
+%% all the other functions.
+%% 
+%% </KOLLA>
+
+sc_lc_recv_response_tcp4(suite) ->
+    [];
+sc_lc_recv_response_tcp4(doc) ->
+    [];
+sc_lc_recv_response_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_lc_recv_response_tcp4,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recv(Sock) end,
+                   InitState = #{domain   => inet,
+                                 protocol => tcp,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recv function.
+%% Socket is IPv6.
+
+sc_lc_recv_response_tcp6(suite) ->
+    [];
+sc_lc_recv_response_tcp6(doc) ->
+    [];
+sc_lc_recv_response_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_lc_recv_response_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recv(Sock) end,
+                   InitState = #{domain   => inet6,
+                                 protocol => tcp,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recv function.
+%% Socket is Unix Domain (stream) socket.
+
+sc_lc_recv_response_tcpL(suite) ->
+    [];
+sc_lc_recv_response_tcpL(doc) ->
+    [];
+sc_lc_recv_response_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_lc_recv_response_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recv(Sock) end,
+                   InitState = #{domain   => local,
+                                 protocol => default,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+sc_lc_receive_response_tcp(InitState) ->
+    %% This (acceptor) is the server that accepts connections.
+    %% But it is also suppose to close the connection socket, 
+    %% and trigger the read failure (=closed) for the handler process.
+    AcceptorSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create (listen) socket",
+           cmd  => fun(#{domain   := Domain, 
+                         protocol := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{domain := local,
+                         lsock  := LSock,
+                         lsa    := LSA} = _State) ->
+                           ?SEV_IPRINT("bind to LSA: "
+                                       "~n   ~p", [LSA]),
+                           case socket:bind(LSock, LSA) of
+                               {ok, _Port} ->
+                                   ok; % We do not care about the port for local
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{lsock := LSock,
+                         lsa   := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   ?SEV_IPRINT("bound to port: ~w", [Port]),
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain := local,
+                         tester := Tester,
+                         lsa    := #{path := Path}}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Path),
+                           ok;
+                      (#{tester := Tester, lport := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+                           
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, accept) of
+                               {ok, {H1, H2, H3}} ->
+                                   {ok, State#{handler1 => H1,
+                                               handler2 => H2,
+                                               handler3 => H3}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await accept",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   ?SEV_IPRINT("connection accepted: "
+                                               "~n   ~p", [socket:sockname(Sock)]),
+                                   {ok, State#{csock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+         #{desc => "transfer connection to handler 1",
+           cmd  => fun(#{handler1 := Handler, csock := Sock}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Handler, transfer, Sock),
+                           ok
+                   end},
+         #{desc => "transfer connection to handler 2",
+           cmd  => fun(#{handler2 := Handler, csock := Sock}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Handler, transfer, Sock),
+                           ok
+                   end},
+         #{desc => "transfer connection to handler 3",
+           cmd  => fun(#{handler3 := Handler, csock := Sock}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Handler, transfer, Sock),
+                           ok
+                   end},
+         #{desc => "await continue (close)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, close),
+                           ok
+                   end},
+         #{desc => "close connection socket",
+           cmd  => fun(#{csock := Sock} = State) ->
+                           case socket:close(Sock) of
+                               ok ->
+                                   {ok, maps:remove(csock, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (close)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, close),
+                           ok
+                   end},
+
+         %% *** Terminate ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{domain := local,
+                         lsock  := Sock,
+                         lsa    := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->maps:remove(lsa, State) end,
+                                           fun() -> State end),
+                           State2 = maps:remove(lsock, State1),
+                           State3 = maps:remove(lport, State2),
+                           {ok, State3};
+                      (#{lsock := Sock} = State) ->
+                           case socket:close(Sock) of
+                               ok ->
+                                   State1 = maps:remove(lsock, State),
+                                   State2 = maps:remove(lport, State1),
+                                   {ok, State2};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    %% The point of this is to perform the recv for which
+    %% we are testing the reponse.
+    HandlerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           {Tester, Acceptor} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester  => Tester, 
+                                      acceptor => Acceptor}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+         #{desc => "monitor acceptor",
+           cmd  => fun(#{acceptor := Acceptor} = _State) ->
+                           _MRef = erlang:monitor(process, Acceptor),
+                           ok
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (transfer)",
+           cmd  => fun(#{acceptor := Pid} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Pid, acceptor, transfer) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (transfer)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, transfer),
+                           ok
+                   end},
+         #{desc => "attempt recv (=> closed)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           %% ok = socket:setopt(Sock, otp, debug, true),
+                           case Recv(Sock) of
+                               {ok, _Data} ->
+                                   ?SEV_EPRINT("Unexpected data received"),
+                                   {error, unexpected_success};
+                               {error, closed} ->
+                                   ?SEV_IPRINT("received expected 'closed' "
+                                               "result"),
+                                   State1 = maps:remove(sock, State),
+                                   {ok, State1};
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("Unexpected read failure: "
+                                               "~n   ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv closed)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_closed),
+                           ok
+                   end},
+
+         %% *** Terminate ***
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    %% The point of this is basically just to create the connection.
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain   := Domain, 
+                         protocol := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind socket to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           ?SEV_IPRINT("bind to LSA: "
+                                       "~n   ~p", [LSA]),
+                           case socket:bind(Sock, LSA) of
+                               {ok, _} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{domain := local = Domain,
+                         tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, connect) of
+                               {ok, ServerPath} ->
+                                   ?SEV_IPRINT("Server Path: "
+                                               "~n   ~s", [ServerPath]),
+                                   ServerSA = #{family => Domain,
+                                                path   => ServerPath},
+                                   {ok, State#{server_sa => ServerSA}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{tester := Tester, local_sa := LSA} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, connect) of
+                               {ok, Port} ->
+                                   ServerSA = LSA#{port => Port},
+                                   {ok, State#{server_sa => ServerSA}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "connect to server",
+           cmd  => fun(#{sock := Sock, server_sa := ServerSA}) ->
+                           socket:connect(Sock, ServerSA)
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+
+         %% *** Terminate ***
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end                           
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{domain   := local,
+                         sock     := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           sock_close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(sock, State1)};
+                       (#{sock := Sock} = State) ->
+                           sock_close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor acceptor",
+           cmd  => fun(#{acceptor := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor handler 1",
+           cmd  => fun(#{handler1 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor handler 2",
+           cmd  => fun(#{handler2 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor handler 3",
+           cmd  => fun(#{handler3 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the acceptor
+         #{desc => "order acceptor start",
+           cmd  => fun(#{acceptor := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await acceptor ready (init)",
+           cmd  => fun(#{acceptor := Pid} = State) ->
+                           case ?SEV_AWAIT_READY(Pid, acceptor, init) of
+                               {ok, PortOrPath} ->
+                                   {ok, State#{server_info => PortOrPath}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% Start the handler(s)
+         #{desc => "order handler 1 start",
+           cmd  => fun(#{acceptor := Acceptor, handler1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Acceptor),
+                           ok
+                   end},
+         #{desc => "await handler 1 ready (init)",
+           cmd  => fun(#{handler1 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, handler1, init)
+                   end},
+         #{desc => "order handler 2 start",
+           cmd  => fun(#{acceptor := Acceptor, handler2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Acceptor),
+                           ok
+                   end},
+         #{desc => "await handler 2 ready (init)",
+           cmd  => fun(#{handler2 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, handler2, init)
+                   end},
+         #{desc => "order handler 3 start",
+           cmd  => fun(#{acceptor := Acceptor, handler3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Acceptor),
+                           ok
+                   end},
+         #{desc => "await handler 3 ready (init)",
+           cmd  => fun(#{handler3 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, handler3, init)
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+
+         %% The actual test
+         #{desc => "order acceptor to continue (accept)",
+           cmd  => fun(#{acceptor := Pid, 
+                         handler1 := H1, 
+                         handler2 := H2, 
+                         handler3 := H3} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept, {H1, H2, H3}),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client to continue (connect)",
+           cmd  => fun(#{client := Pid, server_info := Info} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect, Info),
+                           ok
+                   end},
+         #{desc => "await acceptor ready (accept)",
+           cmd  => fun(#{acceptor := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, acceptor, accept)
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, connect)
+                   end},
+         #{desc => "await handler 1 ready (transfer)",
+           cmd  => fun(#{handler1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, handler1, transfer)
+                   end},
+         #{desc => "await handler 2 ready (transfer)",
+           cmd  => fun(#{handler2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, handler2, transfer)
+                   end},
+         #{desc => "await handler 3 ready (transfer)",
+           cmd  => fun(#{handler3 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, handler3, transfer)
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order acceptor to continue (close connection socket)",
+           cmd  => fun(#{acceptor := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, close),
+                           ok
+                   end},
+         #{desc => "await acceptor ready (close)",
+           cmd  => fun(#{acceptor := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, acceptor, close)
+                   end},
+         #{desc => "await handler 1 ready (recv closed)",
+           cmd  => fun(#{handler1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, handler1, recv_closed)
+                   end},
+         #{desc => "await handler 2 ready (recv closed)",
+           cmd  => fun(#{handler2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, handler2, recv_closed)
+                   end},
+         #{desc => "await handler 3 ready (recv closed)",
+           cmd  => fun(#{handler3 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, handler3, recv_closed)
+                   end},
+
+         %% Terminations
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(client, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order handler 1 to terminate",
+           cmd  => fun(#{handler1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await handler 1 termination",
+           cmd  => fun(#{handler1 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(handler1, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order handler 2 to terminate",
+           cmd  => fun(#{handler2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await handler 2 termination",
+           cmd  => fun(#{handler2 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(handler2, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order handler 3 to terminate",
+           cmd  => fun(#{handler3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await handler 3 termination",
+           cmd  => fun(#{handler3 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(handler3, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order acceptor to terminate",
+           cmd  => fun(#{acceptor := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await acceptor termination",
+           cmd  => fun(#{acceptor := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(acceptor, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start acceptor evaluator"),
+    AccInitState = InitState,
+    Acceptor = ?SEV_START("acceptor", AcceptorSeq, AccInitState),
+
+    i("start handler 1 evaluator"),
+    HandlerInitState = #{recv => maps:get(recv, InitState)},
+    Handler1 = ?SEV_START("handler-1", HandlerSeq, HandlerInitState),
+
+    i("start handler 2 evaluator"),
+    Handler2 = ?SEV_START("handler-2", HandlerSeq, HandlerInitState),
+
+    i("start handler 3 evaluator"),
+    Handler3 = ?SEV_START("handler-3", HandlerSeq, HandlerInitState),
+
+    i("start client evaluator"),
+    ClientInitState = InitState,
+    Client = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("start tester evaluator"),
+    TesterInitState = #{acceptor => Acceptor#ev.pid,
+                        handler1 => Handler1#ev.pid,
+                        handler2 => Handler2#ev.pid,
+                        handler3 => Handler3#ev.pid,
+                        client   => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Acceptor, 
+                            Handler1, Handler2, Handler3, 
+                            Client, Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while a process is calling the recvfrom function.
+%% Socket is IPv4.
+%% 
+
+sc_lc_recvfrom_response_udp4(suite) ->
+    [];
+sc_lc_recvfrom_response_udp4(doc) ->
+    [];
+sc_lc_recvfrom_response_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_lc_recvfrom_response_udp4,
+           fun() ->
+                   Recv      = fun(Sock, To) -> socket:recvfrom(Sock, [], To) end,
+                   InitState = #{domain   => inet,
+                                 protocol => udp,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recv function.
+%% Socket is IPv6.
+
+sc_lc_recvfrom_response_udp6(suite) ->
+    [];
+sc_lc_recvfrom_response_udp6(doc) ->
+    [];
+sc_lc_recvfrom_response_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_lc_recvfrom_response_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv      = fun(Sock, To) -> socket:recvfrom(Sock, [], To) end,
+                   InitState = #{domain   => inet6,
+                                 protocol => udp,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recv function.
+%% Socket is Unix Domainm (dgram) socket.
+
+sc_lc_recvfrom_response_udpL(suite) ->
+    [];
+sc_lc_recvfrom_response_udpL(doc) ->
+    [];
+sc_lc_recvfrom_response_udpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_lc_recvfrom_response_udpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   Recv      = fun(Sock, To) -> socket:recvfrom(Sock, [], To) end,
+                   InitState = #{domain   => local,
+                                 protocol => default,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+sc_lc_receive_response_udp(InitState) ->
+    PrimServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "open socket",
+           cmd  => fun(#{domain := Domain, protocol := Proto} = State) ->
+                           Sock = sock_open(Domain, dgram, Proto),
+                           SA   = sock_sockname(Sock),
+                           {ok, State#{sock => Sock, sa => SA}}
+                   end},
+         #{desc => "bind socket",
+           cmd  => fun(#{sock := Sock, local_sa := LSA}) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ?SEV_IPRINT("src bound"),
+                                   ok;
+                               {error, Reason} = ERROR ->
+                                   ?SEV_EPRINT("src bind failed: ~p", [Reason]),
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, sock := Sock}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Sock),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv, with timeout)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, recv) of
+                               {ok, Timeout} ->
+                                   {ok, State#{timeout => Timeout}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "receive, with timeout",
+           cmd  => fun(#{sock := Sock, recv := Recv, timeout := Timeout}) ->
+                           case Recv(Sock, Timeout) of
+                               {error, timeout} ->
+                                   ok;
+                               {ok, _} ->
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv, with timeout)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv),
+                           ok
+                   end},
+         #{desc => "await continue (close)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ok = ?SEV_AWAIT_CONTINUE(Tester, tester, close)
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{domain   := local,
+                         sock     := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(sock, State1)};
+                      (#{sock := Sock} = State) ->
+                           case socket:close(Sock) of
+                               ok ->
+                                   {ok, maps:remove(sock, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (close)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, close),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, terminate) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    SecServerSeq =
+        [
+         %% *** Init part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, Sock} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, sock => Sock}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ok = ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                           
+                   end},
+         #{desc => "receive",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock, infinity) of
+                               {error, closed} ->
+                                   {ok, maps:remove(sock, State)};
+                               {ok, _} ->
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv closed)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_closed),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor primary server",
+           cmd  => fun(#{prim_server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor secondary server 1",
+           cmd  => fun(#{sec_server1 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor secondary server 2",
+           cmd  => fun(#{sec_server2 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor secondary server 3",
+           cmd  => fun(#{sec_server3 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the primary server
+         #{desc => "order 'primary server' start",
+           cmd  => fun(#{prim_server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await 'primary server' ready (init)",
+           cmd  => fun(#{prim_server := Pid} = State) ->
+                           {ok, Sock} = ?SEV_AWAIT_READY(Pid, prim_server, init),
+                           {ok, State#{sock => Sock}}
+                   end},
+
+         %% Start the secondary server 1
+         #{desc => "order 'secondary server 1' start",
+           cmd  => fun(#{sec_server1 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await 'secondary server 1' ready (init)",
+           cmd  => fun(#{sec_server1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, sec_server1, init)
+                   end},
+
+         %% Start the secondary server 2
+         #{desc => "order 'secondary server 2' start",
+           cmd  => fun(#{sec_server2 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await 'secondary server 2' ready (init)",
+           cmd  => fun(#{sec_server2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, sec_server2, init)
+                   end},
+
+         %% Start the secondary server 3
+         #{desc => "order 'secondary server 3' start",
+           cmd  => fun(#{sec_server3 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await 'secondary server 3' ready (init)",
+           cmd  => fun(#{sec_server3 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, sec_server3, init)
+                   end},
+
+
+         %% The actual test
+         %% Make all the seondary servers continue, with an infinit recvfrom
+         %% and then the prim-server with a timed recvfrom.
+         %% After the prim server notifies us (about the timeout) we order it
+         %% to close the socket, which should cause the all the secondary 
+         %% server to return with error-closed.
+
+         #{desc => "order 'secondary server 1' to continue (recv)",
+           cmd  => fun(#{sec_server1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order 'secondary server 2' to continue (recv)",
+           cmd  => fun(#{sec_server2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order 'secondary server 3' to continue (recv)",
+           cmd  => fun(#{sec_server3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order 'primary server' to continue (recv, with timeout)",
+           cmd  => fun(#{prim_server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv, ?SECS(5)),
+                           ok
+                   end},
+         #{desc => "await 'primary server' ready (recv, with timeout)",
+           cmd  => fun(#{prim_server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, prim_server, recv)
+                   end},
+         #{desc => "order 'primary server' to continue (close)",
+           cmd  => fun(#{prim_server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, close),
+                           ok
+                   end},
+         #{desc => "await 'primary server' ready (close)",
+           cmd  => fun(#{prim_server := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, prim_server, close)
+                   end},
+         #{desc => "await 'secondary server 1' ready (closed)",
+           cmd  => fun(#{sec_server1 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, sec_server1, recv_closed)
+                   end},
+         #{desc => "await 'secondary server 2' ready (closed)",
+           cmd  => fun(#{sec_server2 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, sec_server2, recv_closed)
+                   end},
+         #{desc => "await 'secondary server 3' ready (closed)",
+           cmd  => fun(#{sec_server3 := Pid} = _State) ->
+                           ?SEV_AWAIT_READY(Pid, sec_server3, recv_closed)
+                   end},
+
+         %% Terminations
+         #{desc => "order 'secondary server 3' to terminate",
+           cmd  => fun(#{sec_server3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await 'secondary server 3' termination",
+           cmd  => fun(#{sec_server3 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(sec_server3, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order 'secondary server 2' to terminate",
+           cmd  => fun(#{sec_server2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await 'secondary server 2' termination",
+           cmd  => fun(#{sec_server2 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(sec_server2, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order 'secondary server 1' to terminate",
+           cmd  => fun(#{sec_server1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await 'secondary server 1' termination",
+           cmd  => fun(#{sec_server1 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(sec_server1, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order 'primary server' to terminate",
+           cmd  => fun(#{prim_server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await 'primary server' termination",
+           cmd  => fun(#{prim_server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(prim_server, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+    
+
+    i("start 'primary server' evaluator"),
+    PrimSrvInitState = InitState,
+    PrimServer = ?SEV_START("prim-server", PrimServerSeq, PrimSrvInitState),
+
+    i("start 'secondary server 1' evaluator"),
+    SecSrvInitState = #{recv => maps:get(recv, InitState)},
+    SecServer1 = ?SEV_START("sec-server-1", SecServerSeq, SecSrvInitState),
+
+    i("start 'secondary server 2' evaluator"),
+    SecServer2 = ?SEV_START("sec-server-2", SecServerSeq, SecSrvInitState),
+
+    i("start 'secondary server 3' evaluator"),
+    SecServer3 = ?SEV_START("sec-server-3", SecServerSeq, SecSrvInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{prim_server => PrimServer#ev.pid,
+                        sec_server1 => SecServer1#ev.pid,
+                        sec_server2 => SecServer2#ev.pid,
+                        sec_server3 => SecServer3#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([PrimServer, 
+                            SecServer1, SecServer2, SecServer3,
+                            Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recvmsg function.
+%% Socket is IPv4.
+
+sc_lc_recvmsg_response_tcp4(suite) ->
+    [];
+sc_lc_recvmsg_response_tcp4(doc) ->
+    [];
+sc_lc_recvmsg_response_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_lc_recvmsg_response_tcp4,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recvmsg(Sock) end,
+                   InitState = #{domain   => inet,
+                                 protocol => tcp,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recvmsg function.
+%% Socket is IPv6.
+
+sc_lc_recvmsg_response_tcp6(suite) ->
+    [];
+sc_lc_recvmsg_response_tcp6(doc) ->
+    [];
+sc_lc_recvmsg_response_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_recvmsg_response_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recvmsg(Sock) end,
+                   InitState = #{domain   => inet6,
+                                 protocol => tcp,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recvmsg function.
+%% Socket is Unix Domain (stream) socket.
+
+sc_lc_recvmsg_response_tcpL(suite) ->
+    [];
+sc_lc_recvmsg_response_tcpL(doc) ->
+    [];
+sc_lc_recvmsg_response_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_recvmsg_response_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recvmsg(Sock) end,
+                   InitState = #{domain   => local,
+                                 protocol => default,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recvmsg function.
+%% Socket is IPv4.
+
+sc_lc_recvmsg_response_udp4(suite) ->
+    [];
+sc_lc_recvmsg_response_udp4(doc) ->
+    [];
+sc_lc_recvmsg_response_udp4(_Config) when is_list(_Config) ->
+    tc_try(sc_lc_recvmsg_response_udp4,
+           fun() ->
+                   ?TT(?SECS(10)),
+                   Recv      = fun(Sock, To) -> socket:recvmsg(Sock, To) end,
+                   InitState = #{domain   => inet,
+                                 protocol => udp,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recvmsg function.
+%% Socket is IPv6.
+
+sc_lc_recvmsg_response_udp6(suite) ->
+    [];
+sc_lc_recvmsg_response_udp6(doc) ->
+    [];
+sc_lc_recvmsg_response_udp6(_Config) when is_list(_Config) ->
+    tc_try(sc_recvmsg_response_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(10)),
+                   Recv      = fun(Sock, To) -> socket:recvmsg(Sock, To) end,
+                   InitState = #{domain   => inet6,
+                                 protocol => udp,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the recvmsg function.
+%% Socket is Unix Domain (dgram) socket.
+
+sc_lc_recvmsg_response_udpL(suite) ->
+    [];
+sc_lc_recvmsg_response_udpL(doc) ->
+    [];
+sc_lc_recvmsg_response_udpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_recvmsg_response_udpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   Recv      = fun(Sock, To) -> socket:recvmsg(Sock, To) end,
+                   InitState = #{domain   => local,
+                                 protocol => default,
+                                 recv     => Recv},
+                   ok = sc_lc_receive_response_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the accept function.
+%% We test what happens with a non-controlling_process also, since we 
+%% git the setup anyway.
+%% Socket is IPv4.
+
+sc_lc_acceptor_response_tcp4(suite) ->
+    [];
+sc_lc_acceptor_response_tcp4(doc) ->
+    [];
+sc_lc_acceptor_response_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_lc_acceptor_response_tcp4,
+           fun() ->
+                   InitState = #{domain   => inet,
+                                 protocol => tcp},
+                   ok = sc_lc_acceptor_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the accept function.
+%% We test what happens with a non-controlling_process also, since we 
+%% git the setup anyway.
+%% Socket is IPv6.
+
+sc_lc_acceptor_response_tcp6(suite) ->
+    [];
+sc_lc_acceptor_response_tcp6(doc) ->
+    [];
+sc_lc_acceptor_response_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_lc_acceptor_response_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain   => inet6,
+                                 protocol => tcp},
+                   ok = sc_lc_acceptor_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% locally closed while the process is calling the accept function.
+%% We test what happens with a non-controlling_process also, since we 
+%% git the setup anyway.
+%% Socket is Unix Domain (stream) socket.
+
+sc_lc_acceptor_response_tcpL(suite) ->
+    [];
+sc_lc_acceptor_response_tcpL(doc) ->
+    [];
+sc_lc_acceptor_response_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_lc_acceptor_response_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain   => local,
+                                 protocol => default},
+                   ok = sc_lc_acceptor_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+sc_lc_acceptor_response_tcp(InitState) ->
+    PrimAcceptorSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{lsa => LSA}}
+                   end},
+         #{desc => "create (listen) socket",
+           cmd  => fun(#{domain   := Domain, 
+                         protocol := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, lsa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{sock := Sock}) ->
+                           socket:listen(Sock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Sock),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, accept) of
+                               {ok, Timeout} ->
+                                   {ok, State#{timeout => Timeout}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await connection",
+           cmd  => fun(#{sock := LSock, timeout := Timeout} = _State) ->
+                           case socket:accept(LSock, Timeout) of
+                               {error, timeout} ->
+                                   ok;
+                               {ok, Sock} ->
+                                   ?SEV_EPRINT("unexpected success"),
+                                   (catch socket:close(Sock)),
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept timeout)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept_timeout),
+                           ok
+                   end},
+         #{desc => "await continue (close)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ok = ?SEV_AWAIT_CONTINUE(Tester, tester, close)
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{domain := local,
+                         sock   := Sock,
+                         lsa    := #{path := Path}} = State) ->
+                           case socket:close(Sock) of
+                               ok ->
+                                   State1 =
+                                       unlink_path(Path,
+                                                   fun() ->
+                                                           maps:remove(lsa, State)
+                                                   end,
+                                                   fun() ->
+                                                           State
+                                                   end),
+                                   {ok, maps:remove(sock, State1)};
+                               {error, _} = ERROR ->
+                                   unlink_path(Path),
+                                   ERROR
+                           end;
+                      (#{sock := Sock} = State) ->
+                           case socket:close(Sock) of
+                               ok ->
+                                   {ok, maps:remove(sock, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (close)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, close),
+                           ok
+                   end},
+
+                                                % Termination
+         #{desc => "await terminate",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    SecAcceptorSeq =
+        [
+         %% *** Init part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, Sock} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, sock => Sock}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init)
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ok = ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "accept",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           case socket:accept(Sock) of
+                               {error, closed} ->
+                                   {ok, maps:remove(sock, State)};
+                               {ok, _} ->
+                                   {error, unexpected_success};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept closed)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept_closed)
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor 'primary acceptor'",
+           cmd  => fun(#{prim_acc := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor 'secondary acceptor 1'",
+           cmd  => fun(#{sec_acc1 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor secondary acceptor 2",
+           cmd  => fun(#{sec_acc2 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor secondary acceptor 3",
+           cmd  => fun(#{sec_acc3 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the primary server
+         #{desc => "order 'primary acceptor' start",
+           cmd  => fun(#{prim_acc := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await 'primary acceptor' ready (init)",
+           cmd  => fun(#{prim_acc := Pid} = State) ->
+                           {ok, Sock} = ?SEV_AWAIT_READY(Pid, prim_acc, init),
+                           {ok, State#{sock => Sock}}
+                   end},
+
+         %% Start the secondary acceptor 1
+         #{desc => "order 'secondary acceptor 1' start",
+           cmd  => fun(#{sec_acc1 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await 'secondary acceptor 1' ready (init)",
+           cmd  => fun(#{sec_acc1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, sec_acc1, init)
+                   end},
+
+         %% Start the secondary acceptor 2
+         #{desc => "order 'secondary acceptor 2' start",
+           cmd  => fun(#{sec_acc2 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await 'secondary acceptor 2' ready (init)",
+           cmd  => fun(#{sec_acc2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, sec_acc2, init)
+                   end},
+
+         %% Start the secondary acceptor 3
+         #{desc => "order 'secondary acceptor 3' start",
+           cmd  => fun(#{sec_acc3 := Pid, sock := Sock} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Sock),
+                           ok
+                   end},
+         #{desc => "await 'secondary acceptor 3' ready (init)",
+           cmd  => fun(#{sec_acc3 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, sec_acc3, init)
+                   end},
+
+
+         %% The actual test
+         %% Make all the seondary servers continue, with an infinit recvfrom
+         %% and then the prim-server with a timed recvfrom.
+         %% After the prim server notifies us (about the timeout) we order it
+         %% to close the socket, which should cause the all the secondary 
+         %% server to return with error-closed.
+
+         #{desc => "order 'secondary acceptor 1' to continue (accept)",
+           cmd  => fun(#{sec_acc1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order 'secondary acceptor 2' to continue (accept)",
+           cmd  => fun(#{sec_acc2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order 'secondary acceptor 3' to continue (accept)",
+           cmd  => fun(#{sec_acc3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order 'primary acceptor' to continue",
+           cmd  => fun(#{prim_acc := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept, ?SECS(5)),
+                           ok
+                   end},
+         #{desc => "await 'primary acceptor' ready (accept timeout)",
+           cmd  => fun(#{prim_acc := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, prim_acc, accept_timeout)
+                   end},
+         #{desc => "order 'primary acceptor' to continue (close)",
+           cmd  => fun(#{prim_acc := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, close),
+                           ok
+                   end},
+         #{desc => "await 'primary acceptor' ready (close)",
+           cmd  => fun(#{prim_acc := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, prim_acc, close)
+                   end},
+         #{desc => "await 'secondary acceptor 1' ready (accept closed)",
+           cmd  => fun(#{sec_acc1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, sec_acc1, accept_closed)
+                   end},
+         #{desc => "await 'secondary acceptor 2' ready (accept closed)",
+           cmd  => fun(#{sec_acc2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, sec_acc2, accept_closed)
+                   end},
+         #{desc => "await 'secondary acceptor 3' ready (accept closed)",
+           cmd  => fun(#{sec_acc3 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, sec_acc3, accept_closed)
+                   end},
+
+
+         %% Terminations
+         #{desc => "order 'secondary acceptor 3' to terminate",
+           cmd  => fun(#{sec_acc3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await 'secondary acceptor 3' termination",
+           cmd  => fun(#{sec_acc3 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(sec_acc3, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order 'secondary acceptor 2' to terminate",
+           cmd  => fun(#{sec_acc2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await 'secondary acceptor 2' termination",
+           cmd  => fun(#{sec_acc2 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(sec_acc2, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order 'secondary acceptor 1' to terminate",
+           cmd  => fun(#{sec_acc1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await 'secondary acceptor 1' termination",
+           cmd  => fun(#{sec_acc1 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(sec_acc1, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order 'primary acceptor' to terminate",
+           cmd  => fun(#{prim_acc := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await 'primary acceptor' termination",
+           cmd  => fun(#{prim_acc := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   {ok, maps:remove(prim_acc, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    i("start 'primary acceptor' evaluator"),
+    PrimAccInitState = InitState,
+    PrimAcc = ?SEV_START("prim-acceptor", PrimAcceptorSeq, PrimAccInitState),
+
+    i("start 'secondary acceptor 1' evaluator"),
+    SecAccInitState = #{},
+    SecAcc1 = ?SEV_START("sec-acceptor-1", SecAcceptorSeq, SecAccInitState),
+
+    i("start 'secondary acceptor 2' evaluator"),
+    SecAcc2 = ?SEV_START("sec-acceptor-2", SecAcceptorSeq, SecAccInitState),
+
+    i("start 'secondary acceptor 3' evaluator"),
+    SecAcc3 = ?SEV_START("sec-acceptor-3", SecAcceptorSeq, SecAccInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{prim_acc => PrimAcc#ev.pid,
+                        sec_acc1 => SecAcc1#ev.pid,
+                        sec_acc2 => SecAcc2#ev.pid,
+                        sec_acc3 => SecAcc3#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([PrimAcc, SecAcc1, SecAcc2, SecAcc3, Tester]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% remotely closed while the process is calling the recv function.
+%% Socket is IPv4.
+%%
+%% To minimize the chance of "weirdness", we should really have test cases
+%% where the two sides of the connection is on different machines. But for
+%% now, we will make do with different VMs on the same host.
+%%
+
+sc_rc_recv_response_tcp4(suite) ->
+    [];
+sc_rc_recv_response_tcp4(doc) ->
+    [];
+sc_rc_recv_response_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_rc_recv_response_tcp4,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recv(Sock) end,
+                   InitState = #{domain   => inet,
+                                 protocol => tcp,
+                                 recv     => Recv},
+                   ok = sc_rc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% remotely closed while the process is calling the recv function.
+%% Socket is IPv6.
+
+sc_rc_recv_response_tcp6(suite) ->
+    [];
+sc_rc_recv_response_tcp6(doc) ->
+    [];
+sc_rc_recv_response_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_rc_recv_response_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recv(Sock) end,
+                   InitState = #{domain   => inet6,
+                                 protocol => tcp,
+                                 recv     => Recv},
+                   ok = sc_rc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% remotely closed while the process is calling the recv function.
+%% Socket is Unix Domain (stream) socket.
+
+sc_rc_recv_response_tcpL(suite) ->
+    [];
+sc_rc_recv_response_tcpL(doc) ->
+    [];
+sc_rc_recv_response_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_rc_recv_response_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recv(Sock) end,
+                   InitState = #{domain   => local,
+                                 protocol => default,
+                                 recv     => Recv},
+                   ok = sc_rc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+sc_rc_receive_response_tcp(InitState) ->
+    %% Each connection are handled by handler processes.
+    %% These are created (on the fly) and handled internally 
+    %% by the server!
+    ServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain, protocol := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{domain := local,
+                         lsock  := LSock,
+                         lsa    := LSA} = _State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, _Port} ->
+                                   ok; % We do not care about the port for local
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{lsock    := LSock,
+                         local_sa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain   := local,
+                         tester   := Tester,
+                         local_sa := LSA}) ->
+                           %% Actually we only need to send the path,
+                           %% but to keep it simple, we send the "same"
+                           %% as for non-local.
+                           ?SEV_ANNOUNCE_READY(Tester, init, LSA),
+                           ok;
+                      (#{tester := Tester, local_sa := LSA, lport := Port}) ->
+                           ServerSA = LSA#{port => Port},
+                           ?SEV_ANNOUNCE_READY(Tester, init, ServerSA),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept all three connections)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "accept 1",
+           cmd  => fun(#{lsock := LSock, recv := Recv} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   ?SEV_IPRINT("accepted: try start handler"),
+                                   Handler = sc_rc_tcp_handler_start(1, Recv, Sock),
+                                   ?SEV_IPRINT("handler started"),
+                                   {ok, State#{csock1   => Sock,
+                                               handler1 => Handler}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await handler 1 ready (init)",
+           cmd  => fun(#{tester   := Tester, 
+                         handler1 := Handler1} = _State) ->
+                           ?SEV_AWAIT_READY(Handler1, handler1, init, 
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "accept 2",
+           cmd  => fun(#{lsock := LSock, recv := Recv} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   ?SEV_IPRINT("accepted: try start handler"),
+                                   Handler = sc_rc_tcp_handler_start(2, Recv, Sock),
+                                   ?SEV_IPRINT("handler started"),
+                                   {ok, State#{csock2   => Sock,
+                                               handler2 => Handler}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await handler 2 ready (init)",
+           cmd  => fun(#{tester   := Tester, 
+                         handler1 := Handler1, 
+                         handler2 := Handler2} = _State) ->
+                           ?SEV_AWAIT_READY(Handler2, handler2, init, 
+                                            [{tester,   Tester},
+                                             {handler1, Handler1}])
+                   end},
+         #{desc => "accept 3",
+           cmd  => fun(#{lsock := LSock, recv := Recv} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   ?SEV_IPRINT("accepted: try start handler"),
+                                   Handler = sc_rc_tcp_handler_start(3, Recv, Sock),
+                                   ?SEV_IPRINT("handler started"),
+                                   {ok, State#{csock3   => Sock,
+                                               handler3 => Handler}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await handler 3 ready (init)",
+           cmd  => fun(#{tester   := Tester, 
+                         handler1 := Handler1, 
+                         handler2 := Handler2, 
+                         handler3 := Handler3} = _State) ->
+                           ?SEV_AWAIT_READY(Handler3, handler3, init, 
+                                            [{tester,   Tester},
+                                             {handler1, Handler1},
+                                             {handler2, Handler2}])
+                   end},
+         #{desc => "announce ready (accept all three connections)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "order handler 1 to receive",
+           cmd  => fun(#{handler1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "order handler 2 to receive",
+           cmd  => fun(#{handler2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "order handler 3 to receive",
+           cmd  => fun(#{handler3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await ready from handler 1 (recv)",
+           cmd  => fun(#{tester := Tester, handler1 := Pid} = _State) ->
+                           case ?SEV_AWAIT_READY(Pid, handler1, recv, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await ready from handler 2 (recv)",
+           cmd  => fun(#{tester := Tester, handler2 := Pid} = _State) ->
+                           case ?SEV_AWAIT_READY(Pid, handler2, recv, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await ready from handler 3 (recv)",
+           cmd  => fun(#{tester := Tester, handler3 := Pid} = _State) ->
+                           case ?SEV_AWAIT_READY(Pid, handler3, recv, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv closed from all handlers)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_closed),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order handler 1 to terminate",
+           cmd  => fun(#{handler1 := Pid} = _State) ->
+                           %% Pid ! {terminate, self(), ok},
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await handler 1 termination",
+           cmd  => fun(#{handler1 := Pid} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Pid),
+                           State1 = maps:remove(csock1,   State),
+                           State2 = maps:remove(handler1, State1),
+                           {ok, State2}
+                   end},
+         #{desc => "order handler 2 to terminate",
+           cmd  => fun(#{handler2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await handler 2 termination",
+           cmd  => fun(#{handler2 := Pid} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Pid),
+                           State1 = maps:remove(csock2,   State),
+                           State2 = maps:remove(handler2, State1),
+                           {ok, State2}
+                   end},
+         #{desc => "order handler 3 to terminate",
+           cmd  => fun(#{handler3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await handler 3 termination",
+           cmd  => fun(#{handler3 := Pid} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Pid),
+                           State1 = maps:remove(csock3,   State),
+                           State2 = maps:remove(handler3, State1),
+                           {ok, State2}
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{domain := local,
+                         lsock  := LSock,
+                         lsa    := #{path := Path}} = State) ->
+                           case socket:close(LSock) of
+                               ok ->
+                                   State1 =
+                                       unlink_path(Path,
+                                                   fun() ->
+                                                           maps:remove(lsa, State)
+                                                   end,
+                                                   fun() ->
+                                                           State
+                                                   end),
+                                   {ok, maps:remove(lsock, State1)};
+                               {error, _} = ERROR ->
+                                   unlink_path(Path),
+                                   ERROR
+                           end;
+                      (#{lsock := LSock} = State) ->
+                           case socket:close(LSock) of
+                               ok ->
+                                   {ok, maps:remove(lsock, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, {NodeID, ServerSA}} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester    => Tester, 
+                                       node_id   => NodeID, 
+                                       server_sa => ServerSA}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "create node",
+           cmd  => fun(#{host := Host, node_id := NodeID} = State) ->
+                           case start_node(Host, l2a(f("client_~w", [NodeID]))) of
+                               {ok, Node} ->
+                                   ?SEV_IPRINT("client node ~p started", [Node]),
+                                   {ok, State#{node => Node}};
+                               {error, Reason} ->
+                                   {skip, Reason}
+                           end
+                   end},
+         #{desc => "monitor client node 1",
+           cmd  => fun(#{node := Node} = _State) ->
+                           true = erlang:monitor_node(Node, true),
+                           ok
+                   end},
+         #{desc => "start remote client on client node",
+           cmd  => fun(#{node := Node} = State) ->
+                           Pid = sc_rc_tcp_client_start(Node),
+                           ?SEV_IPRINT("client ~p started", [Pid]),
+                           {ok, State#{rclient => Pid}}
+                   end},
+         #{desc => "monitor remote client",
+           cmd  => fun(#{rclient := Pid}) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "order remote client to start",
+           cmd  => fun(#{rclient   := Client,
+                         server_sa := ServerSA,
+                         protocol  := Proto}) ->
+                           ?SEV_ANNOUNCE_START(Client, {ServerSA, Proto}),
+                           ok
+                   end},
+         #{desc => "await remote client ready",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, init, 
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect, 
+                                               [{rclient, Client}]),
+                           ok
+                   end},
+         #{desc => "order remote client to continue (connect)",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, connect),
+                           ok
+                   end},
+         #{desc => "await client process ready (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, connect, 
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (connected)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+         #{desc => "await continue (close)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, close, 
+                                               [{rclient, Client}]),
+                           ok
+                   end},
+         #{desc => "order remote client to close",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, close),
+                           ok
+                   end},
+         #{desc => "await remote client ready (closed)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, close, 
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (close)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, close),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester  := Tester, 
+                         rclient := Client} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester,
+                                                     [{rclient, Client}]) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "kill remote client",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await remote client termination",
+           cmd  => fun(#{rclient := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(rclient, State),
+                           {ok, State1}
+                   end},
+         #{desc => "stop client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           stop_node(Node)
+                   end},
+         #{desc => "await client node termination",
+           cmd  => fun(#{node := Node} = State) ->
+                           receive
+                               {nodedown, Node} ->
+                                   State1 = maps:remove(node_id, State),
+                                   State2 = maps:remove(node,    State1),
+                                   {ok, State2}
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client 1",
+           cmd  => fun(#{client1 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client 2",
+           cmd  => fun(#{client2 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client 3",
+           cmd  => fun(#{client3 := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, ServerSA} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+
+         %% Start the client(s)
+         #{desc => "order client 1 start",
+           cmd  => fun(#{client1   := Pid, 
+                         server_sa := ServerSA} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, {1, ServerSA}),
+                           ok
+                   end},
+         #{desc => "await client 1 ready (init)",
+           cmd  => fun(#{client1 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client1, init)
+                   end},
+         #{desc => "order client 2 start",
+           cmd  => fun(#{client2   := Pid, 
+                         server_sa := ServerSA} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, {2, ServerSA}),
+                           ok
+                   end},
+         #{desc => "await client 2 ready (init)",
+           cmd  => fun(#{client2 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client2, init)
+                   end},
+         #{desc => "order client 3 start",
+           cmd  => fun(#{client3   := Pid, 
+                         server_sa := ServerSA} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, {3, ServerSA}),
+                           ok
+                   end},
+         #{desc => "await client 3 ready (init)",
+           cmd  => fun(#{client3 := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client3, init)
+                   end},
+
+         %% The actual test
+         #{desc => "order server continue (accept)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client 1 continue (connect)",
+           cmd  => fun(#{client1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect),
+                           ok
+                   end},
+         #{desc => "await client 1 ready (connect)",
+           cmd  => fun(#{server  := Server,
+                         client1 := Client1,
+                         client2 := Client2,
+                         client3 := Client3} = _State) ->
+                           ?SEV_AWAIT_READY(Client1, client1, connect, 
+                                            [{server,  Server},
+                                             {client2, Client2},
+                                             {client3, Client3}]),
+                           ok
+                   end},
+         #{desc => "order client 2 continue (connect)",
+           cmd  => fun(#{client2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect),
+                           ok
+                   end},
+         #{desc => "await client 2 ready (connect)",
+           cmd  => fun(#{server  := Server,
+                         client1 := Client1,
+                         client2 := Client2,
+                         client3 := Client3} = _State) ->
+                           ?SEV_AWAIT_READY(Client2, client2, connect, 
+                                            [{server,  Server},
+                                             {client1, Client1},
+                                             {client3, Client3}]),
+                           ok
+                   end},
+         #{desc => "order client 3 continue (connect)",
+           cmd  => fun(#{client3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect),
+                           ok
+                   end},
+         #{desc => "await client 3 ready (connect)",
+           cmd  => fun(#{server  := Server,
+                         client1 := Client1,
+                         client2 := Client2,
+                         client3 := Client3} = _State) ->
+                           ?SEV_AWAIT_READY(Client3, client3, connect, 
+                                            [{server,  Server},
+                                             {client1, Client1},
+                                             {client2, Client2}]),
+                           ok
+                   end},
+         #{desc => "await server ready (accept from all connections)",
+           cmd  => fun(#{server  := Server,
+                         client1 := Client1,
+                         client2 := Client2,
+                         client3 := Client3} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, accept,
+                                            [{client1, Client1},
+                                             {client2, Client2},
+                                             {client3, Client3}]),
+                           ok
+                   end},
+         #{desc => "order server continue (recv for all connections)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client 1 continue (close)",
+           cmd  => fun(#{client1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, close),
+                           ok
+                   end},
+         #{desc => "await client 1 ready (close)",
+           cmd  => fun(#{server  := Server,
+                         client1 := Client1,
+                         client2 := Client2,
+                         client3 := Client3} = _State) ->
+                           ?SEV_AWAIT_READY(Client1, client1, close, 
+                                            [{server,  Server},
+                                             {client2, Client2},
+                                             {client3, Client3}]),
+                           ok
+                   end},
+         #{desc => "order client 2 continue (close)",
+           cmd  => fun(#{client2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, close),
+                           ok
+                   end},
+         #{desc => "await client 2 ready (close)",
+           cmd  => fun(#{server  := Server,
+                         client1 := Client1,
+                         client2 := Client2,
+                         client3 := Client3} = _State) ->
+                           ?SEV_AWAIT_READY(Client2, client2, close, 
+                                            [{server,  Server},
+                                             {client1, Client1},
+                                             {client3, Client3}]),
+                           ok
+                   end},
+         #{desc => "order client 3 continue (close)",
+           cmd  => fun(#{client3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, close),
+                           ok
+                   end},
+         #{desc => "await client 3 ready (close)",
+           cmd  => fun(#{server  := Server,
+                         client1 := Client1,
+                         client2 := Client2,
+                         client3 := Client3} = _State) ->
+                           ?SEV_AWAIT_READY(Client3, client1, close, 
+                                            [{server,  Server},
+                                             {client1, Client1},
+                                             {client2, Client2}]),
+                           ok
+                   end},
+         #{desc => "await server ready (close for all connections)",
+           cmd  => fun(#{server  := Server,
+                         client1 := Client1,
+                         client2 := Client2,
+                         client3 := Client3} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, recv_closed,
+                                            [{client1, Client1},
+                                             {client2, Client2},
+                                             {client3, Client3}]),
+                           ok
+                   end},
+
+         %% Terminations
+         #{desc => "order client 1 to terminate",
+           cmd  => fun(#{client1 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await client 1 termination",
+           cmd  => fun(#{client1 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(client1, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order client 2 to terminate",
+           cmd  => fun(#{client2 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await client 2 termination",
+           cmd  => fun(#{client2 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(client2, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order client 3 to terminate",
+           cmd  => fun(#{client3 := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await client 3 termination",
+           cmd  => fun(#{client3 := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(client3, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    ServerInitState = InitState,
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator(s)"),
+    ClientInitState = InitState#{host => local_host()},
+    Client1 = ?SEV_START("client-1", ClientSeq, ClientInitState),
+    Client2 = ?SEV_START("client-2", ClientSeq, ClientInitState),
+    Client3 = ?SEV_START("client-3", ClientSeq, ClientInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server  => Server#ev.pid,
+                        client1 => Client1#ev.pid,
+                        client2 => Client2#ev.pid,
+                        client3 => Client3#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server,
+                            Client1, Client2, Client3,
+                            Tester]).
+
+
+sc_rc_tcp_client_start(Node) ->
+    Self = self(),
+    Fun  = fun() -> sc_rc_tcp_client(Self) end,
+    erlang:spawn(Node, Fun).
+
+
+sc_rc_tcp_client(Parent) ->
+    sc_rc_tcp_client_init(Parent),
+    {ServerSA, Proto} = sc_rc_tcp_client_await_start(Parent),
+    Domain   = maps:get(family, ServerSA),
+    Sock     = sc_rc_tcp_client_create(Domain, Proto),
+    Path     = sc_rc_tcp_client_bind(Sock, Domain),
+    sc_rc_tcp_client_announce_ready(Parent, init),
+    sc_rc_tcp_client_await_continue(Parent, connect),
+    sc_rc_tcp_client_connect(Sock, ServerSA),
+    sc_rc_tcp_client_announce_ready(Parent, connect),
+    sc_rc_tcp_client_await_continue(Parent, close),
+    sc_rc_tcp_client_close(Sock, Path),
+    sc_rc_tcp_client_announce_ready(Parent, close),
+    Reason = sc_rc_tcp_client_await_terminate(Parent),
+    ?SEV_IPRINT("terminate"),
+    exit(Reason).
+
+sc_rc_tcp_client_init(Parent) ->
+    put(sname, "rclient"),
+    ?SEV_IPRINT("init"),
+    _MRef = erlang:monitor(process, Parent),
+    ok.
+
+sc_rc_tcp_client_await_start(Parent) ->
+    i("sc_rc_tcp_client_await_start -> entry"),
+    ?SEV_AWAIT_START(Parent).
+
+sc_rc_tcp_client_create(Domain, Proto) ->
+    i("sc_rc_tcp_client_create -> entry"),
+    case socket:open(Domain, stream, Proto) of
+        {ok, Sock} ->
+            case socket:getopt(Sock, otp, fd) of
+                {ok, FD} ->
+                    put(sname, f("rclient-~w", [FD])); % Update SName
+                _ ->
+                    ok
+            end,
+            Sock;
+        {error, Reason} ->
+            exit({open_failed, Reason})
+    end.
+
+sc_rc_tcp_client_bind(Sock, Domain) ->
+    i("sc_rc_tcp_client_bind -> entry"),
+    LSA = which_local_socket_addr(Domain),
+    case socket:bind(Sock, LSA) of
+        {ok, _} ->
+            case socket:sockname(Sock) of
+                {ok, #{family := local, path := Path}} ->
+                    Path;
+                {ok, _} ->
+                    undefined;
+                {error, Reason1} ->
+                    exit({sockname, Reason1})
+            end;
+        {error, Reason} ->
+            exit({bind, Reason})
+    end.
+
+sc_rc_tcp_client_announce_ready(Parent, Slogan) ->
+    ?SEV_IPRINT("ready ~w", [Slogan]),
+    ?SEV_ANNOUNCE_READY(Parent, Slogan).
+
+sc_rc_tcp_client_await_continue(Parent, Slogan) ->
+    ?SEV_IPRINT("await ~w continue", [Slogan]),
+    ?SEV_AWAIT_CONTINUE(Parent, parent, Slogan).
+
+sc_rc_tcp_client_connect(Sock, ServerSA) ->
+    i("sc_rc_tcp_client_connect -> entry"),
+    case socket:connect(Sock, ServerSA) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            exit({connect, Reason})
+    end.
+
+sc_rc_tcp_client_close(Sock, Path) ->
+    i("sc_rc_tcp_client_close -> entry"),
+    case socket:close(Sock) of
+        ok ->
+            unlink_path(Path),
+            ok;
+        {error, Reason} ->
+            ?SEV_EPRINT("failed closing: "
+                        "~n   Reason: ~p", [Reason]),
+            unlink_path(Path),
+            {error, {close, Reason}}
+    end.
+
+sc_rc_tcp_client_await_terminate(Parent) ->
+    i("sc_rc_tcp_client_await_terminate -> entry"),
+    case ?SEV_AWAIT_TERMINATE(Parent, parent) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            Reason
+    end.
+
+
+%% The handlers run on the same node as the server (the local node).
+
+sc_rc_tcp_handler_start(ID, Recv, Sock) ->
+    Self     = self(),
+    Fun      = fun() -> sc_rc_tcp_handler(ID, Self, Recv, Sock) end,
+    {Pid, _} = erlang:spawn_monitor(Fun),
+    Pid.
+
+sc_rc_tcp_handler(ID, Parent, Recv, Sock) ->
+    sc_rc_tcp_handler_init(ID, socket:getopt(Sock, otp, fd), Parent),
+    sc_rc_tcp_handler_await(Parent, recv),
+    RecvRes = sc_rc_tcp_handler_recv(Recv, Sock),
+    sc_rc_tcp_handler_announce_ready(Parent, recv, RecvRes),
+    Reason = sc_rc_tcp_handler_await(Parent, terminate),
+    exit(Reason).
+
+sc_rc_tcp_handler_init(ID, {ok, FD}, Parent) ->
+    put(sname, f("handler-~w:~w", [ID, FD])),
+    _MRef = erlang:monitor(process, Parent),
+    ?SEV_IPRINT("started"),
+    ?SEV_ANNOUNCE_READY(Parent, init),
+    ok.
+
+sc_rc_tcp_handler_await(Parent, terminate) ->
+    ?SEV_IPRINT("await terminate"),
+    ?SEV_AWAIT_TERMINATE(Parent, tester);
+sc_rc_tcp_handler_await(Parent, Slogan) ->
+    ?SEV_IPRINT("await ~w", [Slogan]),
+    ?SEV_AWAIT_CONTINUE(Parent, parent, Slogan).
+
+sc_rc_tcp_handler_recv(Recv, Sock) ->
+    ?SEV_IPRINT("recv"),
+    try Recv(Sock) of
+        {error, closed} ->
+            ok;
+        {ok, _} ->
+            ?SEV_IPRINT("unexpected success"),
+            {error, unexpected_success};
+        {error, Reason} = ERROR ->
+            ?SEV_IPRINT("receive error: "
+                        "~n   ~p", [Reason]),
+            ERROR
+    catch
+        C:E:S ->
+            ?SEV_IPRINT("receive failure: "
+                        "~n   Class: ~p"
+                        "~n   Error: ~p"
+                        "~n   Stack: ~p", [C, E, S]),
+            {error, {recv, C, E, S}}
+    end.
+
+sc_rc_tcp_handler_announce_ready(Parent, Slogan, Result) ->
+    ?SEV_IPRINT("announce ready"),
+    ?SEV_ANNOUNCE_READY(Parent, Slogan, Result),
+    ok.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% remotely closed while the process is calling the recvmsg function.
+%% Socket is IPv4.
+
+sc_rc_recvmsg_response_tcp4(suite) ->
+    [];
+sc_rc_recvmsg_response_tcp4(doc) ->
+    [];
+sc_rc_recvmsg_response_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_rc_recvmsg_response_tcp4,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recvmsg(Sock) end,
+                   InitState = #{domain   => inet,
+                                 protocol => tcp,
+                                 recv     => Recv},
+                   ok = sc_rc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% remotely closed while the process is calling the recvmsg function.
+%% Socket is IPv6.
+
+sc_rc_recvmsg_response_tcp6(suite) ->
+    [];
+sc_rc_recvmsg_response_tcp6(doc) ->
+    [];
+sc_rc_recvmsg_response_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_rc_recvmsg_response_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recvmsg(Sock) end,
+                   InitState = #{domain   => inet6,
+                                 protocol => tcp,
+                                 recv     => Recv},
+                   ok = sc_rc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is 
+%% remotely closed while the process is calling the recvmsg function.
+%% Socket is Unix Domain (stream) socket.
+
+sc_rc_recvmsg_response_tcpL(suite) ->
+    [];
+sc_rc_recvmsg_response_tcpL(doc) ->
+    [];
+sc_rc_recvmsg_response_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_rc_recvmsg_response_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   Recv      = fun(Sock) -> socket:recvmsg(Sock) end,
+                   InitState = #{domain   => local,
+                                 protocol => default,
+                                 recv     => Recv},
+                   ok = sc_rc_receive_response_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is
+%% remotely closed while the process is calling the recv function.
+%% The remote client sends data, then shutdown(write) and then the
+%% reader attempts a recv.
+%% Socket is IPv4.
+%%
+%% To minimize the chance of "weirdness", we should really have test cases
+%% where the two sides of the connection is on different machines. But for
+%% now, we will make do with different VMs on the same host.
+%% This would of course not work for Unix Domain sockets.
+%%
+
+sc_rs_recv_send_shutdown_receive_tcp4(suite) ->
+    [];
+sc_rs_recv_send_shutdown_receive_tcp4(doc) ->
+    [];
+sc_rs_recv_send_shutdown_receive_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(sc_rs_recv_send_shutdown_receive_tcp4,
+           fun() ->
+                   MsgData   = ?DATA,
+                   Recv      = fun(Sock) ->
+                                       socket:recv(Sock)
+                               end,
+                   Send      = fun(Sock, Data) ->
+                                       socket:send(Sock, Data)
+                               end,
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 recv   => Recv,
+                                 send   => Send,
+                                 data   => MsgData},
+                   ok = sc_rs_send_shutdown_receive_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is
+%% remotely closed while the process is calling the recv function.
+%% The remote client sends data, then shutdown(write) and then the
+%% reader attempts a recv.
+%% Socket is IPv6.
+
+sc_rs_recv_send_shutdown_receive_tcp6(suite) ->
+    [];
+sc_rs_recv_send_shutdown_receive_tcp6(doc) ->
+    [];
+sc_rs_recv_send_shutdown_receive_tcp6(_Config) when is_list(_Config) ->
+    tc_try(sc_rs_recv_send_shutdown_receive_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(10)),
+                   MsgData   = ?DATA,
+                   Recv      = fun(Sock) ->
+                                       socket:recv(Sock)
+                               end,
+                   Send      = fun(Sock, Data) ->
+                                       socket:send(Sock, Data)
+                               end,
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 recv   => Recv,
+                                 send   => Send,
+                                 data   => MsgData},
+                   ok = sc_rs_send_shutdown_receive_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is
+%% remotely closed while the process is calling the recv function.
+%% The remote client sends data, then shutdown(write) and then the
+%% reader attempts a recv.
+%% Socket is Unix Domain (stream) socket.
+
+sc_rs_recv_send_shutdown_receive_tcpL(suite) ->
+    [];
+sc_rs_recv_send_shutdown_receive_tcpL(doc) ->
+    [];
+sc_rs_recv_send_shutdown_receive_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_rs_recv_send_shutdown_receive_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   MsgData   = ?DATA,
+                   Recv      = fun(Sock) ->
+                                       socket:recv(Sock)
+                               end,
+                   Send      = fun(Sock, Data) ->
+                                       socket:send(Sock, Data)
+                               end,
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 recv   => Recv,
+                                 send   => Send,
+                                 data   => MsgData},
+                   ok = sc_rs_send_shutdown_receive_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+sc_rs_send_shutdown_receive_tcp(InitState) ->
+    %% The connection is handled by a handler processes.
+    %% This are created (on the fly) and handled internally
+    %% by the server!
+    ServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           i("get local address for ~p", [Domain]),
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain, proto := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{domain   := local,
+                         lsock    := LSock,
+                         local_sa := LSA} = _State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, _Port} ->
+                                   ok; % We do not care about the port for local
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{lsock := LSock, local_sa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   ?SEV_IPRINT("bound to port: ~w", [Port]),
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain := local,
+                         tester := Tester, local_sa := LSA}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, LSA),
+                           ok;
+                      (#{tester := Tester, local_sa := LSA, lport := Port}) ->
+                           ServerSA = LSA#{port => Port},
+                           ?SEV_ANNOUNCE_READY(Tester, init, ServerSA),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "accept",
+           cmd  => fun(#{lsock := LSock, recv := Recv} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   ?SEV_IPRINT("accepted: try start handler"),
+                                   Handler =
+                                       sc_rs_tcp_handler_start(Recv, Sock),
+                                   ?SEV_IPRINT("handler started"),
+                                   {ok, State#{csock   => Sock,
+                                               handler => Handler}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await handler ready (init)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = _State) ->
+                           ?SEV_AWAIT_READY(Handler, handler, init,
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+
+         #{desc => "await continue (first recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "order handler to receive (first)",
+           cmd  => fun(#{handler := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await ready from handler (first recv)",
+           cmd  => fun(#{tester := Tester, handler := Pid} = _State) ->
+                           case ?SEV_AWAIT_READY(Pid, handler, recv,
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   ?SEV_IPRINT("first recv: ~p", [Result]),
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (first recv)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv),
+                           ok
+                   end},
+         #{desc => "await continue (second recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "order handler to receive (second)",
+           cmd  => fun(#{handler := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await ready from handler (second recv)",
+           cmd  => fun(#{tester := Tester, handler := Pid} = _State) ->
+                           case ?SEV_AWAIT_READY(Pid, handler, recv,
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   ?SEV_IPRINT("second recv: ~p", [Result]),
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (second recv)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order handler to terminate",
+           cmd  => fun(#{handler := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await handler termination",
+           cmd  => fun(#{handler := Pid} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Pid),
+                           State1 = maps:remove(csock,   State),
+                           State2 = maps:remove(handler, State1),
+                           {ok, State2}
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{domain   := local,
+                         lsock    := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(lsock, State1)};
+                      (#{lsock := LSock} = State) ->
+                           case socket:close(LSock) of
+                               ok ->
+                                   {ok, maps:remove(lsock, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, ServerSA} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester    => Tester, 
+                                       server_sa => ServerSA}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "create node",
+           cmd  => fun(#{host := Host} = State) ->
+                           case start_node(Host, client) of
+                               {ok, Node} ->
+                                   ?SEV_IPRINT("client node ~p started",
+                                               [Node]),
+                                   {ok, State#{node => Node}};
+                               {error, Reason} ->
+                                   {skip, Reason}
+                           end
+                   end},
+         #{desc => "monitor client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           true = erlang:monitor_node(Node, true),
+                           ok
+                   end},
+         #{desc => "start remote client on client node",
+           cmd  => fun(#{node := Node,
+                         send := Send} = State) ->
+                           Pid = sc_rs_tcp_client_start(Node, Send),
+                           ?SEV_IPRINT("client ~p started", [Pid]),
+                           {ok, State#{rclient => Pid}}
+                   end},
+         #{desc => "monitor remote client",
+           cmd  => fun(#{rclient := Pid}) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "order remote client to start",
+           cmd  => fun(#{rclient   := Client,
+                         proto     := Proto,
+                         server_sa := ServerSA}) ->
+                           ?SEV_ANNOUNCE_START(Client, {ServerSA, Proto}),
+                           ok
+                   end},
+         #{desc => "await remote client ready",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, init, 
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect, 
+                                               [{rclient, Client}]),
+                           ok
+                   end},
+         #{desc => "order remote client to continue (connect)",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, connect),
+                           ok
+                   end},
+         #{desc => "await client process ready (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, connect,
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+
+         #{desc => "await continue (send)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, send,
+                                                    [{rclient, Client}]) of
+                               {ok, Data} ->
+                                   {ok, State#{rclient_data => Data}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to send",
+           cmd  => fun(#{rclient      := Client,
+                         rclient_data := Data}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Data),
+                           ok
+                   end},
+         #{desc => "await remote client ready (closed)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, send,
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (send)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send),
+                           ok
+                   end},
+
+
+         #{desc => "await continue (shutdown)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, shutdown,
+                                               [{rclient, Client}]),
+                           ok
+                   end},
+         #{desc => "order remote client to shutdown",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, shutdown),
+                           ok
+                   end},
+         #{desc => "await remote client ready (shiutdown)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, shutdown,
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (shutdown)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, shutdown),
+                           ok
+                   end},
+
+         #{desc => "await continue (close)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, close,
+                                               [{rclient, Client}]),
+                           ok
+                   end},
+         #{desc => "order remote client to close",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, close),
+                           ok
+                   end},
+         #{desc => "await remote client ready (closed)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, close,
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (close)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, close),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester,
+                                                     [{rclient, Client}]) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "kill remote client",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await remote client termination",
+           cmd  => fun(#{rclient := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(rclient, State),
+                           {ok, State1}
+                   end},
+         #{desc => "stop client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           stop_node(Node)
+                   end},
+         #{desc => "await client node termination",
+           cmd  => fun(#{node := Node} = State) ->
+                           receive
+                               {nodedown, Node} ->
+                                   State1 = maps:remove(node_id, State),
+                                   State2 = maps:remove(node,    State1),
+                                   {ok, State2}
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, ServerSA} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+
+         %% Start the client(s)
+         #{desc => "order client start",
+           cmd  => fun(#{client    := Pid,
+                         server_sa := ServerSA} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, ServerSA),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+
+         %% The actual test
+         #{desc => "order server continue (accept)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client continue (connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect),
+                           ok
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, connect,
+                                            [{server, Server}]),
+                           ok
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, accept,
+                                            [{client, Client}]),
+                           ok
+                   end},
+
+         #{desc => "order client continue (send)",
+           cmd  => fun(#{client := Pid,
+                         data   := Data} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, send, Data),
+                           ok
+                   end},
+         #{desc => "await client ready (send)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, send,
+                                            [{server, Server}]),
+                           ok
+                   end},
+
+         #{desc => "order client continue (shutdown)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, shutdown),
+                           ok
+                   end},
+         #{desc => "await client ready (shutdown)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, shutdown,
+                                            [{server, Server}]),
+                           ok
+                   end},
+
+         #{desc => "order server continue (first recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await server ready (first recv)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, recv,
+                                            [{client, Client}]),
+                           ok
+                   end},
+
+         #{desc => "order server continue (second recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await server ready (second recv)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, recv,
+                                            [{client, Client}]),
+                           ok
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order client continue (close)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, close),
+                           ok
+                   end},
+         #{desc => "await client ready (close)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, close,
+                                            [{server, Server}]),
+                           ok
+                   end},
+
+         %% Terminations
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(client, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    ServerInitState = #{domain => maps:get(domain, InitState),
+                        proto  => maps:get(proto,  InitState),
+                        recv   => maps:get(recv,   InitState)},
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator"),
+    ClientInitState = #{host   => local_host(),
+                        domain => maps:get(domain, InitState),
+                        proto  => maps:get(proto,  InitState),
+                        send   => maps:get(send, InitState)},
+    Client = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid,
+                        data   => maps:get(data, InitState)},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+sc_rs_tcp_client_start(Node, Send) ->
+    Self = self(),
+    Fun  = fun() -> sc_rs_tcp_client(Self, Send) end,
+    erlang:spawn(Node, Fun).
+
+
+sc_rs_tcp_client(Parent, Send) ->
+    sc_rs_tcp_client_init(Parent),
+    {ServerSA, Proto} = sc_rs_tcp_client_await_start(Parent),
+    Domain   = maps:get(family, ServerSA),
+    Sock     = sc_rs_tcp_client_create(Domain, Proto),
+    Path     = sc_rs_tcp_client_bind(Sock, Domain),
+    sc_rs_tcp_client_announce_ready(Parent, init),
+    sc_rs_tcp_client_await_continue(Parent, connect),
+    sc_rs_tcp_client_connect(Sock, ServerSA),
+    sc_rs_tcp_client_announce_ready(Parent, connect),
+    Data = sc_rs_tcp_client_await_continue(Parent, send),
+    sc_rs_tcp_client_send(Sock, Send, Data),
+    sc_rs_tcp_client_announce_ready(Parent, send),
+    sc_rs_tcp_client_await_continue(Parent, shutdown),
+    sc_rs_tcp_client_shutdown(Sock),
+    sc_rs_tcp_client_announce_ready(Parent, shutdown),
+    sc_rs_tcp_client_await_continue(Parent, close),
+    sc_rs_tcp_client_close(Sock, Path),
+    sc_rs_tcp_client_announce_ready(Parent, close),
+    Reason = sc_rs_tcp_client_await_terminate(Parent),
+    ?SEV_IPRINT("terminate"),
+    exit(Reason).
+
+sc_rs_tcp_client_init(Parent) ->
+    put(sname, "rclient"),
+    ?SEV_IPRINT("init"),
+    _MRef = erlang:monitor(process, Parent),
+    ok.
+
+sc_rs_tcp_client_await_start(Parent) ->
+    i("sc_rs_tcp_client_await_start -> entry"),
+    ?SEV_AWAIT_START(Parent).
+
+sc_rs_tcp_client_create(Domain, Proto) ->
+    i("sc_rs_tcp_client_create -> entry"),
+    case socket:open(Domain, stream, Proto) of
+        {ok, Sock} ->
+            Sock;
+        {error, Reason} ->
+            exit({open_failed, Reason})
+    end.
+
+sc_rs_tcp_client_bind(Sock, Domain) ->
+    i("sc_rs_tcp_client_bind -> entry"),
+    LSA = which_local_socket_addr(Domain),
+    case socket:bind(Sock, LSA) of
+        {ok, _} ->
+            case socket:sockname(Sock) of
+                {ok, #{family := local, path := Path}} ->
+                    Path;
+                {ok, _} ->
+                    undefined;
+                {error, Reason1} ->
+                    exit({sockname, Reason1})
+            end;
+        {error, Reason} ->
+            exit({bind, Reason})
+    end.
+
+sc_rs_tcp_client_announce_ready(Parent, Slogan) ->
+    ?SEV_ANNOUNCE_READY(Parent, Slogan).
+
+sc_rs_tcp_client_await_continue(Parent, Slogan) ->
+    i("sc_rs_tcp_client_await_continue -> entry"),
+    case ?SEV_AWAIT_CONTINUE(Parent, parent, Slogan) of
+        ok ->
+            ok;
+        {ok, Extra} ->
+            Extra;
+        {error, Reason} ->
+            exit({await_continue, Slogan, Reason})
+    end.
+
+
+sc_rs_tcp_client_connect(Sock, ServerSA) ->
+    i("sc_rs_tcp_client_connect -> entry"),
+    case socket:connect(Sock, ServerSA) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            exit({connect, Reason})
+    end.
+
+sc_rs_tcp_client_send(Sock, Send, Data) ->
+    i("sc_rs_tcp_client_send -> entry"),
+    case Send(Sock, Data) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            exit({send, Reason})
+    end.
+
+sc_rs_tcp_client_shutdown(Sock) ->
+    i("sc_rs_tcp_client_shutdown -> entry"),
+    case socket:shutdown(Sock, write) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            exit({shutdown, Reason})
+    end.
+
+sc_rs_tcp_client_close(Sock, Path) ->
+    i("sc_rs_tcp_client_close -> entry"),
+    case socket:close(Sock) of
+        ok ->
+            unlink_path(Path),
+            ok;
+        {error, Reason} ->
+            ?SEV_EPRINT("failed closing: "
+                        "~n   Reason: ~p", [Reason]),
+            unlink_path(Path),
+            {error, {close, Reason}}
+    end.
+
+sc_rs_tcp_client_await_terminate(Parent) ->
+    i("sc_rs_tcp_client_await_terminate -> entry"),
+    case ?SEV_AWAIT_TERMINATE(Parent, parent) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            Reason
+    end.
+
+
+%% The handlers run on the same node as the server (the local node).
+
+sc_rs_tcp_handler_start(Recv, Sock) ->
+    Self     = self(),
+    Fun      = fun() -> sc_rs_tcp_handler(Self, Recv, Sock) end,
+    {Pid, _} = erlang:spawn_monitor(Fun),
+    Pid.
+
+sc_rs_tcp_handler(Parent, Recv, Sock) ->
+    sc_rs_tcp_handler_init(Parent),
+    sc_rs_tcp_handler_await(Parent, recv),
+    ok = sc_rs_tcp_handler_recv(Recv, Sock, true),
+    sc_rs_tcp_handler_announce_ready(Parent, recv, received),
+    sc_rs_tcp_handler_await(Parent, recv),
+    ok = sc_rs_tcp_handler_recv(Recv, Sock, false),
+    sc_rs_tcp_handler_announce_ready(Parent, recv, closed),
+    Reason = sc_rs_tcp_handler_await(Parent, terminate),
+    exit(Reason).
+
+sc_rs_tcp_handler_init(Parent) ->
+    put(sname, "handler"),
+    _MRef = erlang:monitor(process, Parent),
+    ?SEV_IPRINT("started"),
+    ?SEV_ANNOUNCE_READY(Parent, init),
+    ok.
+
+sc_rs_tcp_handler_await(Parent, terminate) ->
+    ?SEV_IPRINT("await terminate"),
+    ?SEV_AWAIT_TERMINATE(Parent, tester);
+sc_rs_tcp_handler_await(Parent, Slogan) ->
+    ?SEV_IPRINT("await ~w", [Slogan]),
+    ?SEV_AWAIT_CONTINUE(Parent, parent, Slogan).
+
+%% This hould actually work - we leave it for now
+sc_rs_tcp_handler_recv(Recv, Sock, First) ->
+    ?SEV_IPRINT("recv"),
+    try Recv(Sock) of
+        {ok, _} when (First =:= true) ->
+            ok;
+        {error, closed} when (First =:= false) ->
+            ok;
+        {ok, _} ->
+            ?SEV_IPRINT("unexpected success"),
+            {error, unexpected_success};
+        {error, Reason} = ERROR ->
+            ?SEV_IPRINT("receive error: "
+                        "~n   ~p", [Reason]),
+            ERROR
+    catch
+        C:E:S ->
+            ?SEV_IPRINT("receive failure: "
+                        "~n   Class: ~p"
+                        "~n   Error: ~p"
+                        "~n   Stack: ~p", [C, E, S]),
+            {error, {recv, C, E, S}}
+    end.
+
+sc_rs_tcp_handler_announce_ready(Parent, Slogan, Result) ->
+    ?SEV_IPRINT("announce ready"),
+    ?SEV_ANNOUNCE_READY(Parent, Slogan, Result),
+    ok.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is
+%% remotely closed while the process is calling the recvmsg function.
+%% The remote client sends data, then shutdown(write) and then the
+%% reader attempts a recv.
+%% Socket is IPv4.
+
+sc_rs_recvmsg_send_shutdown_receive_tcp4(suite) ->
+    [];
+sc_rs_recvmsg_send_shutdown_receive_tcp4(doc) ->
+    [];
+sc_rs_recvmsg_send_shutdown_receive_tcp4(_Config) when is_list(_Config) ->
+    tc_try(sc_rs_recvmsg_send_shutdown_receive_tcp4,
+           fun() ->
+                   ?TT(?SECS(30)),
+                   MsgData   = ?DATA,
+                   Recv      = fun(Sock) ->
+                                       case socket:recvmsg(Sock) of
+                                           {ok, #{addr  := undefined,
+                                                  iov   := [Data]}} ->
+                                               {ok, Data};
+                                           {error, _} = ERROR ->
+                                               ERROR
+                                       end
+                               end,
+                   Send      = fun(Sock, Data) when is_binary(Data) ->
+                                  MsgHdr = #{iov => [Data]},
+                                  socket:sendmsg(Sock, MsgHdr)
+                               end,
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 recv   => Recv,
+                                 send   => Send,
+                                 data   => MsgData},
+                   ok = sc_rs_send_shutdown_receive_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is
+%% remotely closed while the process is calling the recvmsg function.
+%% The remote client sends data, then shutdown(write) and then the
+%% reader attempts a recv.
+%% Socket is IPv6.
+
+sc_rs_recvmsg_send_shutdown_receive_tcp6(suite) ->
+    [];
+sc_rs_recvmsg_send_shutdown_receive_tcp6(doc) ->
+    [];
+sc_rs_recvmsg_send_shutdown_receive_tcp6(_Config) when is_list(_Config) ->
+    tc_try(sc_rs_recvmsg_send_shutdown_receive_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(10)),
+                   MsgData   = ?DATA,
+                   Recv      = fun(Sock) ->
+                                       case socket:recvmsg(Sock) of
+                                           {ok, #{addr  := undefined,
+                                                  iov   := [Data]}} ->
+                                               {ok, Data};
+                                           {error, _} = ERROR ->
+                                               ERROR
+                                       end
+                               end,
+                   Send      = fun(Sock, Data) when is_binary(Data) ->
+                                       MsgHdr = #{iov => [Data]},
+                                       socket:sendmsg(Sock, MsgHdr)
+                               end,
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 recv   => Recv,
+                                 send   => Send,
+                                 data   => MsgData},
+                   ok = sc_rs_send_shutdown_receive_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test what happens when a socket is
+%% remotely closed while the process is calling the recvmsg function.
+%% The remote client sends data, then shutdown(write) and then the
+%% reader attempts a recv.
+%% Socket is UNix Domain (stream) socket.
+
+sc_rs_recvmsg_send_shutdown_receive_tcpL(suite) ->
+    [];
+sc_rs_recvmsg_send_shutdown_receive_tcpL(doc) ->
+    [];
+sc_rs_recvmsg_send_shutdown_receive_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(10)),
+    tc_try(sc_rs_recvmsg_send_shutdown_receive_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   {ok, CWD} = file:get_cwd(),
+                   ?SEV_IPRINT("CWD: ~s", [CWD]),
+                   MsgData   = ?DATA,
+                   Recv      = fun(Sock) ->
+                                       case socket:recvmsg(Sock) of
+                                           %% On some platforms, the address
+                                           %% is *not* provided (e.g. FreeBSD)
+                                           {ok, #{addr  := undefined,
+                                                  iov   := [Data]}} ->
+                                               {ok, Data};
+                                           %% On some platforms, the address
+                                           %% *is* provided (e.g. linux)
+                                           {ok, #{addr  := #{family := local},
+                                                  iov   := [Data]}} ->
+                                               {ok, Data};
+                                           {error, _} = ERROR ->
+                                               ERROR
+                                       end
+                               end,
+                   Send      = fun(Sock, Data) when is_binary(Data) ->
+                                       MsgHdr = #{iov => [Data]},
+                                       socket:sendmsg(Sock, MsgHdr)
+                               end,
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 recv   => Recv,
+                                 send   => Send,
+                                 data   => MsgData},
+                   ok = sc_rs_send_shutdown_receive_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use TCP on IPv4.
+
+traffic_send_and_recv_counters_tcp4(suite) ->
+    [];
+traffic_send_and_recv_counters_tcp4(doc) ->
+    [];
+traffic_send_and_recv_counters_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_send_and_recv_counters_tcp4,
+           fun() ->
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 recv   => fun(S)    -> socket:recv(S)    end,
+                                 send   => fun(S, D) -> socket:send(S, D) end},
+                   ok = traffic_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use TCP on IPv6.
+
+traffic_send_and_recv_counters_tcp6(suite) ->
+    [];
+traffic_send_and_recv_counters_tcp6(doc) ->
+    [];
+traffic_send_and_recv_counters_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_send_and_recv_counters_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 recv   => fun(S)    -> socket:recv(S)    end,
+                                 send   => fun(S, D) -> socket:send(S, D) end},
+                   ok = traffic_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use default (TCP) on local.
+
+traffic_send_and_recv_counters_tcpL(suite) ->
+    [];
+traffic_send_and_recv_counters_tcpL(doc) ->
+    [];
+traffic_send_and_recv_counters_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_send_and_recv_counters_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 recv   => fun(S)    -> socket:recv(S)    end,
+                                 send   => fun(S, D) -> socket:send(S, D) end},
+                   ok = traffic_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use TCP on IPv4.
+
+traffic_sendmsg_and_recvmsg_counters_tcp4(suite) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_tcp4(doc) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_sendmsg_and_recvmsg_counters_tcp4,
+           fun() ->
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 recv   => fun(S) ->
+                                                   case socket:recvmsg(S) of
+                                                       {ok, #{addr := _Source,
+                                                              iov  := [Data]}} ->
+                                                           {ok, Data};
+                                                       {error, _} = ERROR ->
+                                                           ERROR
+                                                   end
+                                           end,
+                                 send   => fun(S, Data) ->
+                                                   MsgHdr = #{iov => [Data]},
+                                                   socket:sendmsg(S, MsgHdr)
+                                           end},
+                   ok = traffic_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use TCP on IPv6.
+
+traffic_sendmsg_and_recvmsg_counters_tcp6(suite) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_tcp6(doc) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_sendmsg_and_recvmsg_counters_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 recv   => fun(S) ->
+                                                   case socket:recvmsg(S) of
+                                                       {ok, #{addr := _Source,
+                                                              iov  := [Data]}} ->
+                                                           {ok, Data};
+                                                       {error, _} = ERROR ->
+                                                           ERROR
+                                                   end
+                                           end,
+                                 send   => fun(S, Data) ->
+                                                   MsgHdr = #{iov => [Data]},
+                                                   socket:sendmsg(S, MsgHdr)
+                                           end},
+                   ok = traffic_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use default (TCP) on local.
+
+traffic_sendmsg_and_recvmsg_counters_tcpL(suite) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_tcpL(doc) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_sendmsg_and_recvmsg_counters_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 recv   => fun(S) ->
+                                                   case socket:recvmsg(S) of
+                                                       {ok, #{addr := _Source,
+                                                              iov  := [Data]}} ->
+                                                           {ok, Data};
+                                                       {error, _} = ERROR ->
+                                                           ERROR
+                                                   end
+                                           end,
+                                 send   => fun(S, Data) ->
+                                                   MsgHdr = #{iov => [Data]},
+                                                   socket:sendmsg(S, MsgHdr)
+                                           end},
+                   ok = traffic_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+traffic_send_and_recv_tcp(InitState) ->
+    ServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain, proto := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, eafnosupport = Reason} ->
+                                   {skip, Reason};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{domain   := local,
+                         lsock    := LSock,
+                         local_sa := LSA} = _State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, _Port} ->
+                                   ok; % We do not care about the port for local
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{lsock    := LSock,
+                         local_sa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain   := local,
+                         tester   := Tester,
+                         local_sa := #{path := Path}}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Path),
+                           ok;
+                      (#{tester   := Tester,
+                         lport    := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "accept",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   {ok, State#{csock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "initial counter validation (=zero)",
+           cmd  => fun(#{csock := Sock} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("Validate initial counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(Counters)
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv_and_validate 1)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_and_validate)
+                   end},
+         #{desc => "recv (1)",
+           cmd  => fun(#{csock := Sock,
+                         recv  := Recv} = State) ->
+                           case Recv(Sock) of
+                               {ok, Data} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{read_pkg  => 1,
+                                               read_byte => size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (recv 1)",
+           cmd  => fun(#{csock     := Sock,
+                         read_pkg  := Pkg,
+                         read_byte := Byte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,   Pkg},
+                                      {read_byte,  Byte},
+                                      {read_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (recv_and_validate 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (send_and_validate 1)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_and_validate)
+                   end},
+         #{desc => "send (1)",
+           cmd  => fun(#{csock := Sock,
+                         send  := Send} = State) ->
+                           Data = ?DATA,
+                           case Send(Sock, Data) of
+                               ok ->
+                                   ?SEV_IPRINT("sent ~p bytes", [size(Data)]),
+                                   {ok, State#{write_pkg  => 1,
+                                               write_byte => size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (send 1)",
+           cmd  => fun(#{csock      := Sock,
+                         read_pkg   := RPkg,
+                         read_byte  := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (send_and_validate 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv_and_validate 2)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_and_validate)
+                   end},
+         #{desc => "recv (2)",
+           cmd  => fun(#{csock     := Sock,
+                         recv      := Recv,
+                         read_pkg  := Pkg,
+                         read_byte := Byte} = State) ->
+                           case Recv(Sock) of
+                               {ok, Data} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{read_pkg  => Pkg + 1,
+                                               read_byte => Byte + size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (recv 2)",
+           cmd  => fun(#{csock      := Sock,
+                         read_pkg   := RPkg,
+                         read_byte  := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (recv_and_validate 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (send_and_validate 2)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_and_validate)
+                   end},
+         #{desc => "send (2)",
+           cmd  => fun(#{csock      := Sock,
+                         send       := Send,
+                         write_pkg  := Pkg,
+                         write_byte := Byte} = State) ->
+                           Data = ?DATA,
+                           case Send(Sock, Data) of
+                               ok ->
+                                   ?SEV_IPRINT("sent ~p bytes", [size(Data)]),
+                                   {ok, State#{write_pkg  => Pkg + 1,
+                                               write_byte => Byte + size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (send 2)",
+           cmd  => fun(#{csock      := Sock,
+                         read_pkg   := RPkg,
+                         read_byte  := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (send_and_validate 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_and_validate),
+                           ok
+                   end},
+
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close connection socket (just in case)",
+           cmd  => fun(#{csock := Sock} = State) ->
+                           (catch socket:close(Sock)),
+                           {ok, maps:remove(csock, State)}
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{domain   := local,
+                         lsock    := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(lsock, State1)};
+                      (#{lsock := Sock} = State) ->
+                           (catch socket:close(Sock)),
+                           {ok, maps:remove(lsock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(#{domain := local} = State) ->
+                           {Tester, Path} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_path => Path}};
+                      (State) ->
+                           {Tester, Port} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_port => Port}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which server (local) address",
+           cmd  => fun(#{domain      := local = Domain,
+                         server_path := Path} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = #{family => Domain, path => Path},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}};
+                      (#{domain := Domain, server_port := Port} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = LSA#{port => Port},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain,
+                         proto  := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, eafnosupport = Reason} ->
+                                   {skip, Reason};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect),
+                           ok
+                   end},
+         #{desc => "connect to server",
+           cmd  => fun(#{sock := Sock, server_sa := SSA}) ->
+                           socket:connect(Sock, SSA)
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+
+         #{desc => "await continue (send_and_validate 1)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_and_validate)
+                   end},
+         #{desc => "send (1)",
+           cmd  => fun(#{sock := Sock,
+                         send := Send} = State) ->
+                           Data = ?DATA,
+                           case Send(Sock, Data) of
+                               ok ->
+                                   ?SEV_IPRINT("sent ~p bytes", [size(Data)]),
+                                   {ok, State#{write_pkg  => 1,
+                                               write_byte => size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (send 1)",
+           cmd  => fun(#{sock      := Sock,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (send_and_validate 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv_and_validate 1)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_and_validate)
+                   end},
+         #{desc => "recv (1)",
+           cmd  => fun(#{sock := Sock,
+                         recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {ok, Data} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{read_pkg  => 1,
+                                               read_byte => size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (recv 1)",
+           cmd  => fun(#{sock      := Sock,
+                         read_pkg  := RPkg,
+                         read_byte := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (recv_and_validate 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (send_and_validate 2)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_and_validate)
+                   end},
+         #{desc => "send (2)",
+           cmd  => fun(#{sock       := Sock,
+                         send       := Send,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = State) ->
+                           Data = ?DATA,
+                           case Send(Sock, Data) of
+                               ok ->
+                                   ?SEV_IPRINT("sent ~p bytes", [size(Data)]),
+                                   {ok, State#{write_pkg  => SPkg + 1,
+                                               write_byte => SByte + size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (send 2)",
+           cmd  => fun(#{sock      := Sock,
+                         read_pkg  := RPkg,
+                         read_byte := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (send_and_validate 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv_and_validate 2)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_and_validate)
+                   end},
+         #{desc => "recv (2)",
+           cmd  => fun(#{sock      := Sock,
+                         recv      := Recv,
+                         read_pkg  := RPkg,
+                         read_byte := RByte} = State) ->
+                           case Recv(Sock) of
+                               {ok, Data} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{read_pkg  => RPkg + 1,
+                                               read_byte => RByte + size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (recv 2)",
+           cmd  => fun(#{sock      := Sock,
+                         read_pkg  := RPkg,
+                         read_byte := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (recv_and_validate 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_and_validate),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close connection socket",
+           cmd  => fun(#{domain   := local,
+                         sock     := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(sock, State1)};
+                      (#{sock := Sock} = State) ->
+                           socket:close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{domain := local,
+                         server := Pid} = State) ->
+                           {ok, Path} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{path => Path}};
+                      (#{server := Pid} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{port => Port}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{domain := local,
+                         client := Pid,
+                         path   := Path} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Path),
+                           ok;
+                      (#{client := Pid,
+                         port   := Port} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Port),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+
+         %% *** The actual test ***
+
+         #{desc => "order server to continue (with accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, accept),
+                           ok
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order client to continue (with connect)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, connect),
+                           ok
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, connect)
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, accept)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order server to continue (recv_and_validate 1)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, recv_and_validate),
+                           ok
+                   end},
+         #{desc => "order client to continue (send_and_validate 1)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send_and_validate),
+                           ok
+                   end},
+         #{desc => "await client ready (send_and_validate 1)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, send_and_validate)
+                   end},
+         #{desc => "await server ready (recv_and_validate 1)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, recv_and_validate)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order client to continue (recv_and_validate 1)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, recv_and_validate),
+                           ok
+                   end},
+         #{desc => "order server to continue (send_and_validate 1)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, send_and_validate),
+                           ok
+                   end},
+         #{desc => "await server ready (send_and_validate 1)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, send_and_validate)
+                   end},
+         #{desc => "await client ready (recv_and_validate 1)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, recv_and_validate)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order server to continue (recv_and_validate 2)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, recv_and_validate),
+                           ok
+                   end},
+         #{desc => "order client to continue (send_and_validate 2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send_and_validate),
+                           ok
+                   end},
+         #{desc => "await client ready (send_and_validate 2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, send_and_validate)
+                   end},
+         #{desc => "await server ready (recv_and_validate 2)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, recv_and_validate)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order client to continue (recv_and_validate 2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, recv_and_validate),
+                           ok
+                   end},
+         #{desc => "order server to continue (send_and_validate 2)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, send_and_validate),
+                           ok
+                   end},
+         #{desc => "await server ready (send_and_validate 2)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, send_and_validate)
+                   end},
+         #{desc => "await client ready (recv_and_validate 2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, recv_and_validate)
+                   end},
+
+         %% *** Termination ***
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client, State),
+                           {ok, State1}
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server, State),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    ServerInitState = InitState#{host => local_host()},
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator(s)"),
+    ClientInitState = InitState#{host => local_host()},
+    Client = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+traffic_sar_counters_validation(Counters) ->
+    traffic_sar_counters_validation(Counters, []).
+
+traffic_sar_counters_validation(Counters, []) ->
+    (catch lists:foreach(
+             fun({_Cnt, 0})   -> ok;
+                ({Cnt,  Val}) -> throw({error, {invalid_counter, Cnt, Val}})
+             end,
+             Counters));
+traffic_sar_counters_validation(Counters, [{Cnt, Val}|ValidateCounters]) ->
+    case lists:keysearch(Cnt, 1, Counters) of
+        {value, {Cnt, Val}} ->
+            Counters2 = lists:keydelete(Cnt, 1, Counters),
+            traffic_sar_counters_validation(Counters2, ValidateCounters);
+        {value, {Cnt, _Val}} when (Val =:= any) ->
+            Counters2 = lists:keydelete(Cnt, 1, Counters),
+            traffic_sar_counters_validation(Counters2, ValidateCounters);
+        {value, {Cnt, InvVal}} ->
+            {error, {invalid_counter, Cnt, InvVal, Val}};
+        false ->
+            {error, {unknown_counter, Cnt, Counters}}
+    end.
+
+                          
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use UDP on IPv4.
+
+traffic_sendto_and_recvfrom_counters_udp4(suite) ->
+    [];
+traffic_sendto_and_recvfrom_counters_udp4(doc) ->
+    [];
+traffic_sendto_and_recvfrom_counters_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_sendto_and_recvfrom_counters_udp4,
+           fun() ->
+                   InitState = #{domain => inet,
+                                 proto  => udp,
+                                 recv   => fun(S) ->
+                                                   socket:recvfrom(S)
+                                           end,
+                                 send   => fun(S, Data, Dest) ->
+                                                   socket:sendto(S, Data, Dest)
+                                           end},
+                   ok = traffic_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use UDP on IPv6.
+
+traffic_sendto_and_recvfrom_counters_udp6(suite) ->
+    [];
+traffic_sendto_and_recvfrom_counters_udp6(doc) ->
+    [];
+traffic_sendto_and_recvfrom_counters_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_sendto_and_recvfrom_counters_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain => inet6,
+                                 proto  => udp,
+                                 recv   => fun(S) ->
+                                                   socket:recvfrom(S)
+                                           end,
+                                 send   => fun(S, Data, Dest) ->
+                                                   socket:sendto(S, Data, Dest)
+                                           end},
+                   ok = traffic_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use default (UDP) on local.
+
+traffic_sendto_and_recvfrom_counters_udpL(suite) ->
+    [];
+traffic_sendto_and_recvfrom_counters_udpL(doc) ->
+    [];
+traffic_sendto_and_recvfrom_counters_udpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_sendto_and_recvfrom_counters_udp4,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 recv   => fun(S) ->
+                                                   socket:recvfrom(S)
+                                           end,
+                                 send   => fun(S, Data, Dest) ->
+                                                   socket:sendto(S, Data, Dest)
+                                           end},
+                   ok = traffic_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use UDP on IPv4.
+
+traffic_sendmsg_and_recvmsg_counters_udp4(suite) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_udp4(doc) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_sendmsg_and_recvmsg_counters_udp4,
+           fun() ->
+                   InitState = #{domain => inet,
+                                 proto  => udp,
+                                 recv   => fun(S) ->
+                                                   case socket:recvmsg(S) of
+                                                       {ok, #{addr  := Source,
+                                                              iov   := [Data]}} ->
+                                                           {ok, {Source, Data}};
+                                                       {error, _} = ERROR ->
+                                                           ERROR
+                                                   end
+                                           end,
+                                 send   => fun(S, Data, Dest) ->
+                                                   MsgHdr = #{addr => Dest,
+                                                              iov  => [Data]},
+                                                   socket:sendmsg(S, MsgHdr)
+                                           end},
+                   ok = traffic_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use UDP on IPv6.
+
+traffic_sendmsg_and_recvmsg_counters_udp6(suite) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_udp6(doc) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_udp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_sendmsg_and_recvmsg_counters_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain => inet6,
+                                 proto  => udp,
+                                 recv   => fun(S) ->
+                                                   case socket:recvmsg(S) of
+                                                       {ok, #{addr  := Source,
+                                                              iov   := [Data]}} ->
+                                                           {ok, {Source, Data}};
+                                                       {error, _} = ERROR ->
+                                                           ERROR
+                                                   end
+                                           end,
+                                 send   => fun(S, Data, Dest) ->
+                                                   MsgHdr = #{addr => Dest,
+                                                              iov  => [Data]},
+                                                   socket:sendmsg(S, MsgHdr)
+                                           end},
+                   ok = traffic_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to (simply) test that the counters
+%% for both read and write.
+%% So that its easy to extend, we use fun's for read and write.
+%% We use default (UDP) on local.
+
+traffic_sendmsg_and_recvmsg_counters_udpL(suite) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_udpL(doc) ->
+    [];
+traffic_sendmsg_and_recvmsg_counters_udpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    tc_try(traffic_sendmsg_and_recvmsg_counters_udpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 recv   => fun(S) ->
+                                                   case socket:recvmsg(S) of
+                                                       {ok, #{addr  := Source,
+                                                              iov   := [Data]}} ->
+                                                           {ok, {Source, Data}};
+                                                       {error, _} = ERROR ->
+                                                           ERROR
+                                                   end
+                                           end,
+                                 send   => fun(S, Data, Dest) ->
+                                                   MsgHdr = #{addr => Dest,
+                                                              iov  => [Data]},
+                                                   socket:sendmsg(S, MsgHdr)
+                                           end},
+                   ok = traffic_send_and_recv_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+traffic_send_and_recv_udp(InitState) ->
+    ServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain, proto := Proto} = State) ->
+                           case socket:open(Domain, dgram, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{domain   := local,
+                         sock     := Sock,
+                         local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok; % We do not care about the port for local
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{sock     := LSock,
+                         local_sa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "initial counter validation (=zero)",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("Validate initial counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(Counters)
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain   := local,
+                         tester   := Tester,
+                         local_sa := #{path := Path}}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Path),
+                           ok;
+                      (#{tester   := Tester,
+                         lport    := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Port),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv_and_validate 1)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_and_validate)
+                   end},
+         #{desc => "recv (1)",
+           cmd  => fun(#{sock := Sock,
+                         recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {ok, {ClientSA, Data}} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{client_sa => ClientSA,
+                                               read_pkg  => 1,
+                                               read_byte => size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (recv 1)",
+           cmd  => fun(#{sock      := Sock,
+                         read_pkg  := Pkg,
+                         read_byte := Byte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,   Pkg},
+                                      {read_byte,  Byte},
+                                      {read_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (recv_and_validate 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (send_and_validate 1)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_and_validate)
+                   end},
+         #{desc => "send (1)",
+           cmd  => fun(#{sock      := Sock,
+                         send      := Send,
+                         client_sa := ClientSA} = State) ->
+                           Data = ?DATA,
+                           case Send(Sock, Data, ClientSA) of
+                               ok ->
+                                   ?SEV_IPRINT("sent ~p bytes", [size(Data)]),
+                                   {ok, State#{write_pkg  => 1,
+                                               write_byte => size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (send 1)",
+           cmd  => fun(#{sock       := Sock,
+                         read_pkg   := RPkg,
+                         read_byte  := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (send_and_validate 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv_and_validate 2)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_and_validate)
+                   end},
+         #{desc => "recv (2)",
+           cmd  => fun(#{sock      := Sock,
+                         recv      := Recv,
+                         read_pkg  := Pkg,
+                         read_byte := Byte} = State) ->
+                           case Recv(Sock) of
+                               {ok, {Source, Data}} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{client_sa => Source,
+                                               read_pkg  => Pkg + 1,
+                                               read_byte => Byte + size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (recv 2)",
+           cmd  => fun(#{sock       := Sock,
+                         read_pkg   := RPkg,
+                         read_byte  := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (recv_and_validate 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (send_and_validate 2)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_and_validate)
+                   end},
+         #{desc => "send (2)",
+           cmd  => fun(#{sock       := Sock,
+                         client_sa  := ClientSA,
+                         send       := Send,
+                         write_pkg  := Pkg,
+                         write_byte := Byte} = State) ->
+                           Data = ?DATA,
+                           case Send(Sock, Data, ClientSA) of
+                               ok ->
+                                   ?SEV_IPRINT("sent ~p bytes", [size(Data)]),
+                                   {ok, State#{write_pkg  => Pkg + 1,
+                                               write_byte => Byte + size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (send 2)",
+           cmd  => fun(#{sock       := Sock,
+                         read_pkg   := RPkg,
+                         read_byte  := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (send_and_validate 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_and_validate),
+                           ok
+                   end},
+
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket (just in case)",
+           cmd  => fun(#{domain   := local,
+                         sock     := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(lsock, State1)};
+                      (#{sock := Sock} = State) ->
+                           (catch socket:close(Sock)),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start (from tester)",
+           cmd  => fun(#{domain := local} = State) ->
+                           {Tester, Path} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_path => Path}};
+                      (State) ->
+                           {Tester, Port} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester, server_port => Port}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which server (local) address",
+           cmd  => fun(#{domain      := local = Domain,
+                         server_path := Path} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = #{family => Domain, path => Path},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}};
+                      (#{domain := Domain, server_port := Port} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           SSA = LSA#{port => Port},
+                           {ok, State#{local_sa => LSA, server_sa => SSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain,
+                         proto  := Proto} = State) ->
+                           case socket:open(Domain, dgram, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _Port} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "initial counter validation (=zero)",
+           cmd  => fun(#{sock := Sock} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("Validate initial counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(Counters)
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (send_and_validate 1)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_and_validate)
+                   end},
+         #{desc => "send (1)",
+           cmd  => fun(#{sock      := Sock,
+                         send      := Send,
+                         server_sa := ServerSA} = State) ->
+                           Data = ?DATA,
+                           case Send(Sock, Data, ServerSA) of
+                               ok ->
+                                   ?SEV_IPRINT("sent ~p bytes", [size(Data)]),
+                                   {ok, State#{write_pkg  => 1,
+                                               write_byte => size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (send 1)",
+           cmd  => fun(#{sock       := Sock,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (send_and_validate 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv_and_validate 1)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_and_validate)
+                   end},
+         #{desc => "recv (1)",
+           cmd  => fun(#{sock      := Sock,
+                         recv      := Recv,
+                         server_sa := #{family := local} = ServerSA} = State) ->
+                           case Recv(Sock) of
+                               {ok, {ServerSA, Data}} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{read_pkg  => 1,
+                                               read_byte => size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{sock      := Sock,
+                         recv      := Recv,
+                         server_sa := #{addr := Addr, port := Port}} = State) ->
+                           case Recv(Sock) of
+                               {ok, {#{addr := Addr, port := Port}, Data}} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{read_pkg  => 1,
+                                               read_byte => size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (recv 1)",
+           cmd  => fun(#{sock      := Sock,
+                         read_pkg  := RPkg,
+                         read_byte := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (recv_and_validate 1)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (send_and_validate 2)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, send_and_validate)
+                   end},
+         #{desc => "send (2)",
+           cmd  => fun(#{sock       := Sock,
+                         send       := Send,
+                         server_sa  := ServerSA,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = State) ->
+                           Data = ?DATA,
+                           case Send(Sock, Data, ServerSA) of
+                               ok ->
+                                   ?SEV_IPRINT("sent ~p bytes", [size(Data)]),
+                                   {ok, State#{write_pkg  => SPkg + 1,
+                                               write_byte => SByte + size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (send 2)",
+           cmd  => fun(#{sock       := Sock,
+                         read_pkg   := RPkg,
+                         read_byte  := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (send_and_validate 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_and_validate),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv_and_validate 2)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_and_validate)
+                   end},
+         #{desc => "recv (2)",
+           cmd  => fun(#{sock      := Sock,
+                         server_sa := #{family := local} = ServerSA,
+                         recv      := Recv,
+                         read_pkg  := RPkg,
+                         read_byte := RByte} = State) ->
+                           case Recv(Sock) of
+                               {ok, {ServerSA, Data}} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{read_pkg  => RPkg + 1,
+                                               read_byte => RByte + size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+		      (#{sock      := Sock,
+                         server_sa := #{addr := Addr, port := Port},
+                         recv      := Recv,
+                         read_pkg  := RPkg,
+                         read_byte := RByte} = State) ->
+                           case Recv(Sock) of
+                               {ok, {#{addr := Addr, port := Port}, Data}} ->
+                                   ?SEV_IPRINT("recv ~p bytes", [size(Data)]),
+                                   {ok, State#{read_pkg  => RPkg + 1,
+                                               read_byte => RByte + size(Data)}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "validate (recv 2)",
+           cmd  => fun(#{sock      := Sock,
+                         read_pkg  := RPkg,
+                         read_byte := RByte,
+                         write_pkg  := SPkg,
+                         write_byte := SByte} = _State) ->
+                           try socket:info(Sock) of
+                               #{counters := Counters} ->
+                                   ?SEV_IPRINT("validate counters: "
+                                               "~n   ~p", [Counters]),
+                                   traffic_sar_counters_validation(
+                                     Counters,
+                                     [{read_pkg,    RPkg},
+                                      {read_byte,   RByte},
+                                      {write_pkg,   SPkg},
+                                      {write_byte,  SByte},
+                                      {read_tries,  any},
+                                      {write_tries, any}])
+                           catch
+                               C:E:S ->
+                                   ?SEV_EPRINT("Failed get socket info: "
+                                               "~n   Class: ~p"
+                                               "~n   Error: ~p"
+                                               "~n   Stack: ~p", [C, E, S]),
+                                   {error, {socket_info_failed, {C, E, S}}}
+                           end
+                   end},
+         #{desc => "announce ready (recv_and_validate 2)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_and_validate),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close connection socket",
+           cmd  => fun(#{domain   := local,
+                         sock     := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(sock, State1)};
+                      (#{sock := Sock} = State) ->
+                           socket:close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{domain := local,
+                         server := Pid} = State) ->
+                           {ok, Path} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{path => Path}};
+                      (#{server := Pid} = State) ->
+                           {ok, Port} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{port => Port}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{domain := local,
+                         client := Pid,
+                         path   := Path} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Path),
+                           ok;
+                      (#{client := Pid,
+                         port   := Port} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Port),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+
+         %% *** The actual test ***
+
+         #{desc => "order server to continue (recv_and_validate 1)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, recv_and_validate),
+                           ok
+                   end},
+         #{desc => "order client to continue (send_and_validate 1)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send_and_validate),
+                           ok
+                   end},
+         #{desc => "await client ready (send_and_validate 1)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, send_and_validate)
+                   end},
+         #{desc => "await server ready (recv_and_validate 1)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, recv_and_validate)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order client to continue (recv_and_validate 1)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, recv_and_validate),
+                           ok
+                   end},
+         #{desc => "order server to continue (send_and_validate 1)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, send_and_validate),
+                           ok
+                   end},
+         #{desc => "await server ready (send_and_validate 1)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, send_and_validate)
+                   end},
+         #{desc => "await client ready (recv_and_validate 1)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, recv_and_validate)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order server to continue (recv_and_validate 2)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, recv_and_validate),
+                           ok
+                   end},
+         #{desc => "order client to continue (send_and_validate 2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send_and_validate),
+                           ok
+                   end},
+         #{desc => "await client ready (send_and_validate 2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, send_and_validate)
+                   end},
+         #{desc => "await server ready (recv_and_validate 2)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, recv_and_validate)
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "order client to continue (recv_and_validate 2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, recv_and_validate),
+                           ok
+                   end},
+         #{desc => "order server to continue (send_and_validate 2)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Server, send_and_validate),
+                           ok
+                   end},
+         #{desc => "await server ready (send_and_validate 2)",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, send_and_validate)
+                   end},
+         #{desc => "await client ready (recv_and_validate 2)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, recv_and_validate)
+                   end},
+
+         %% *** Termination ***
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client, State),
+                           {ok, State1}
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Server} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           State1 = maps:remove(server, State),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    ServerInitState = InitState#{host => local_host()},
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator(s)"),
+    ClientInitState = InitState#{host => local_host()},
+    Client = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% behave as expected when sending and/or reading chunks.
+%% First send data in one "big" chunk, and read it in "small" chunks.
+%% Second, send in a bunch of "small" chunks, and read in one "big" chunk.
+%% Socket is IPv4.
+
+traffic_send_and_recv_chunks_tcp4(suite) ->
+    [];
+traffic_send_and_recv_chunks_tcp4(doc) ->
+    [];
+traffic_send_and_recv_chunks_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(traffic_send_and_recv_chunks_tcp4,
+           fun() ->
+                   InitState = #{domain => inet,
+                                 proto  => tcp},
+                   ok = traffic_send_and_recv_chunks_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% behave as expected when sending and/or reading chunks.
+%% First send data in one "big" chunk, and read it in "small" chunks.
+%% Second, send in a bunch of "small" chunks, and read in one "big" chunk.
+%% Socket is IPv6.
+
+traffic_send_and_recv_chunks_tcp6(suite) ->
+    [];
+traffic_send_and_recv_chunks_tcp6(doc) ->
+    [];
+traffic_send_and_recv_chunks_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(traffic_send_and_recv_chunks_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain => inet6,
+                                 proto  => tcp},
+                   ok = traffic_send_and_recv_chunks_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% behave as expected when sending and/or reading chunks.
+%% First send data in one "big" chunk, and read it in "small" chunks.
+%% Second, send in a bunch of "small" chunks, and read in one "big" chunk.
+%% Socket is UNix Domain (Stream) socket.
+
+traffic_send_and_recv_chunks_tcpL(suite) ->
+    [];
+traffic_send_and_recv_chunks_tcpL(doc) ->
+    [];
+traffic_send_and_recv_chunks_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    tc_try(traffic_send_and_recv_chunks_tcp6,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain => local,
+                                 proto  => default},
+                   ok = traffic_send_and_recv_chunks_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+traffic_send_and_recv_chunks_tcp(InitState) ->
+    ServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain, proto := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{domain   := local,
+                         lsock    := LSock,
+                         local_sa := LSA} = _State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, _Port} ->
+                                   ok; % We do not care about the port for local
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{lsock    := LSock,
+                         local_sa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain   := local,
+                         tester   := Tester,
+                         local_sa := LSA}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, LSA),
+                           ok;
+                      (#{tester   := Tester,
+                         local_sa := LSA,
+                         lport    := Port}) ->
+                           ServerSA = LSA#{port => Port},
+                           ?SEV_ANNOUNCE_READY(Tester, init, ServerSA),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "accept",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   {ok, State#{csock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+
+         #{desc => "await continue (recv-many-small)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv_many_small)
+                   end},
+         #{desc => "recv chunk 1",
+           cmd  => fun(#{csock := Sock} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 1 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv chunk 2",
+           cmd  => fun(#{csock  := Sock,
+                         chunks := Chunks} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 2 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)|Chunks]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv chunk 3",
+           cmd  => fun(#{csock  := Sock,
+                         chunks := Chunks} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 3 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)|Chunks]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv chunk 4",
+           cmd  => fun(#{csock  := Sock,
+                         chunks := Chunks} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 4 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)|Chunks]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv chunk 5",
+           cmd  => fun(#{csock  := Sock,
+                         chunks := Chunks} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 5 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)|Chunks]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv chunk 6",
+           cmd  => fun(#{csock  := Sock,
+                         chunks := Chunks} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 6 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)|Chunks]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv chunk 7",
+           cmd  => fun(#{csock  := Sock,
+                         chunks := Chunks} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 7 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)|Chunks]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv chunk 8",
+           cmd  => fun(#{csock  := Sock,
+                         chunks := Chunks} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 8 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)|Chunks]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv chunk 9",
+           cmd  => fun(#{csock  := Sock,
+                         chunks := Chunks} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 9 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)|Chunks]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv chunk 10",
+           cmd  => fun(#{csock  := Sock,
+                         chunks := Chunks} = State) ->
+                           case socket:recv(Sock, 100) of
+                               {ok, Chunk} ->
+                                   ?SEV_IPRINT("recv of chunk 10 of ~p bytes",
+                                               [size(Chunk)]),
+                                   {ok, State#{chunks => [b2l(Chunk)|Chunks]}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv-many-small)",
+           cmd  => fun(#{tester := Tester,
+                         chunks := Chunks} = State) ->
+                           Data = lists:flatten(lists:reverse(Chunks)),
+                           ?SEV_ANNOUNCE_READY(Tester, recv_many_small, Data),
+                           {ok, maps:remove(chunks, State)}
+                   end},
+
+         #{desc => "await continue (recv-one-big)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester, recv_one_big) of
+                               {ok, Size} ->
+                                   {ok, State#{size => Size}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "recv (one big)",
+           cmd  => fun(#{tester := Tester, csock := Sock, size := Size} = _State) ->
+                           %% socket:setopt(Sock, otp, debug, true),
+                           case socket:recv(Sock, Size) of
+                               {ok, Data} ->
+                                   ?SEV_ANNOUNCE_READY(Tester,
+                                                       recv_one_big,
+                                                       b2l(Data)),
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close connection socket (just in case)",
+           cmd  => fun(#{csock := Sock} = State) ->
+                           (catch socket:close(Sock)),
+                           {ok, maps:remove(csock, State)}
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{domain   := local,
+                         lsock    := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           ok = socket:close(Sock),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() ->
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(lsock, State1)};
+                      (#{lsock := Sock} = State) ->
+                           (catch socket:close(Sock)),
+                           {ok, maps:remove(lsock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, ServerSA} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester    => Tester,
+                                       server_sa => ServerSA}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "create node",
+           cmd  => fun(#{host := Host} = State) ->
+                           case start_node(Host, client) of
+                               {ok, Node} ->
+                                   ?SEV_IPRINT("(remote) client node ~p started",
+                                               [Node]),
+                                   {ok, State#{node => Node}};
+                               {error, Reason} ->
+                                   {skip, Reason}
+                           end
+                   end},
+         #{desc => "monitor client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           true = erlang:monitor_node(Node, true),
+                           ok
+                   end},
+         #{desc => "start remote client",
+           cmd  => fun(#{node := Node} = State) ->
+                           Pid = traffic_snr_tcp_client_start(Node),
+                           ?SEV_IPRINT("client ~p started", [Pid]),
+                           {ok, State#{rclient => Pid}}
+                   end},
+         #{desc => "monitor remote client",
+           cmd  => fun(#{rclient := Pid}) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "order remote client to start",
+           cmd  => fun(#{rclient   := Client,
+                         server_sa := ServerSA,
+                         proto     := Proto}) ->
+                           ?SEV_ANNOUNCE_START(Client, {ServerSA, Proto}),
+                           ok
+                   end},
+         #{desc => "await remote client ready",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, init,
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect,
+                                               [{rclient, Client}]),
+                           ok
+                   end},
+         #{desc => "order remote client to continue (connect)",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, connect),
+                           ok
+                   end},
+         #{desc => "await client process ready (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, rclient, connect,
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+
+         #{desc => "await continue (send-one-big)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester,
+                                                    send_one_big,
+                                                    [{rclient, Client}]) of
+                               {ok, Data} ->
+                                   {ok, State#{data => Data}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send)",
+           cmd  => fun(#{rclient := Client, data := Data}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Data),
+                           ok
+                   end},
+         #{desc => "await client process ready (send)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send,
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (send-one-big)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_one_big),
+                           ok
+                   end},
+
+         #{desc => "await continue (send-many-small)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = State) ->
+                           case ?SEV_AWAIT_CONTINUE(Tester, tester,
+                                                    send_many_small,
+                                                    [{rclient, Client}]) of
+                               {ok, Data} ->
+                                   {ok, State#{data => Data}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 1)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, RestData} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 1: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, State#{data => RestData}}
+                   end},
+         #{desc => "await client process ready (send chunk 1)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 2)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, RestData} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 2: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, State#{data => RestData}}
+                   end},
+         #{desc => "await client process ready (send chunk 2)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 3)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, RestData} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 3: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, State#{data => RestData}}
+                   end},
+         #{desc => "await client process ready (send chunk 3)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 4)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, RestData} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 4: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, State#{data => RestData}}
+                   end},
+         #{desc => "await client process ready (send chunk 4)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 5)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, RestData} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 5: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, State#{data => RestData}}
+                   end},
+         #{desc => "await client process ready (send chunk 5)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 6)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, RestData} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 6: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, State#{data => RestData}}
+                   end},
+         #{desc => "await client process ready (send chunk 6)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 7)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, RestData} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 7: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, State#{data => RestData}}
+                   end},
+         #{desc => "await client process ready (send chunk 7)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 8)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, RestData} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 8: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, State#{data => RestData}}
+                   end},
+         #{desc => "await client process ready (send chunk 8)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 9)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, RestData} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 9: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, State#{data => RestData}}
+                   end},
+         #{desc => "await client process ready (send chunk 9)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send chunk 10)",
+           cmd  => fun(#{rclient := Client,
+                         data    := Data} = State) ->
+                           {Chunk, []} = lists:split(100, Data),
+                           %% ?SEV_IPRINT("order send of chunk 10: "
+                           %%             "~n   Size: ~p"
+                           %%             "~n   ~p", [length(Chunk), Chunk]),
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, Chunk),
+                           {ok, maps:remove(data, State)}
+                   end},
+         #{desc => "await client process ready (send chunk 10)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order remote client to continue (send stop)",
+           cmd  => fun(#{rclient := Client} = State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, send, stop),
+                           {ok, maps:remove(data, State)}
+                   end},
+         #{desc => "await client process ready (send stop)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Client, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   Result;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (send-many-small)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send_many_small),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester  := Tester, 
+                         rclient := Client} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester,
+                                                     [{rclient, Client}]) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "kill remote client",
+           cmd  => fun(#{rclient := Client}) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await remote client termination",
+           cmd  => fun(#{rclient := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(rclient, State),
+                           {ok, State1}
+                   end},
+         #{desc => "stop client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           stop_node(Node)
+                   end},
+         #{desc => "await client node termination",
+           cmd  => fun(#{node := Node} = State) ->
+                           receive
+                               {nodedown, Node} ->
+                                   {ok, maps:remove(node, State)}
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, ServerSA} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client    := Pid, 
+                         server_sa := ServerSA} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, ServerSA),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+ 
+         %% The actual test
+         #{desc => "order server continue (accept)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client continue (connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect),
+                           ok
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, accept,
+                                            [{client, Client}]),
+                           ok
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, connect, 
+                                            [{server, Server}])
+                   end},
+
+         #{desc => "generate data",
+           cmd  => fun(State) ->
+                           D1 = lists:seq(1,250),
+                           D2 = lists:duplicate(4, D1),
+                           D3 = lists:flatten(D2),
+                           {ok, State#{data => D3}}
+                   end},
+
+         %% (client) Send one big and (server) recv may small
+         #{desc => "order server continue (recv-many-small)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv_many_small),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client continue (send-one-big)",
+           cmd  => fun(#{client := Pid, data := Data} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, send_one_big, Data),
+                           ok
+                   end},
+         #{desc => "await client ready (send-one-big)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Client, client, send_one_big, 
+                                                 [{server, Server}])
+                   end},
+         #{desc => "await server ready (recv-many-small)",
+           cmd  => fun(#{server := Server,
+                         client := Client, 
+                         data   := Data} = _State) ->
+                           case ?SEV_AWAIT_READY(Server, server, recv_many_small,
+                                                 [{client, Client}]) of
+                               {ok, Data} ->
+                                   ok;
+                               {ok, OtherData} ->
+                                   {error, {mismatched_data, Data, OtherData}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         #{desc => "order server continue (recv-one-big)",
+           cmd  => fun(#{server := Pid, data := Data} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv_one_big, length(Data)),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client continue (send-many-small)",
+           cmd  => fun(#{client := Pid, data := Data} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, send_many_small, Data),
+                           ok
+                   end},
+         #{desc => "await client ready (send-many-small)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Client, client, send_many_small, 
+                                                 [{server, Server}])
+                   end},
+         #{desc => "await server ready (recv-one-big)",
+           cmd  => fun(#{server := Server,
+                         client := Client, 
+                         data   := Data} = State) ->
+                           case ?SEV_AWAIT_READY(Server, server, recv_one_big,
+                                                 [{client, Client}]) of
+                               {ok, Data} ->
+                                   {ok, maps:remove(data, State)};
+                               {ok, OtherData} ->
+                                   {error, {mismatched_data, Data, OtherData}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+         %% Terminations
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(client, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    ServerInitState = InitState,
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator(s)"),
+    ClientInitState = InitState#{host => local_host()},
+    Client = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+    
+
+
+traffic_snr_tcp_client_start(Node) ->
+    Self = self(),
+    Fun  = fun() -> traffic_snr_tcp_client(Self) end,
+    erlang:spawn(Node, Fun).
+
+traffic_snr_tcp_client(Parent) ->
+    {Sock, ServerSA, Path} = traffic_snr_tcp_client_init(Parent),
+    traffic_snr_tcp_client_announce_ready(Parent, init),
+    traffic_snr_tcp_client_await_continue(Parent, connect),
+    traffic_snr_tcp_client_connect(Sock, ServerSA),
+    traffic_snr_tcp_client_announce_ready(Parent, connect),
+    traffic_snr_tcp_client_send_loop(Parent, Sock),
+    Reason = traffic_snr_tcp_client_await_terminate(Parent),
+    traffic_snr_tcp_client_close(Sock, Path),
+    exit(Reason).
+
+
+traffic_snr_tcp_client_send_loop(Parent, Sock) ->
+    case ?SEV_AWAIT_CONTINUE(Parent, parent, send) of
+        {ok, stop} -> % Breakes the loop
+            ?SEV_ANNOUNCE_READY(Parent, send, ok),
+            ok;
+        {ok, Data} ->
+            case socket:send(Sock, Data) of
+                ok ->
+                    ?SEV_ANNOUNCE_READY(Parent, send, ok),
+                    traffic_snr_tcp_client_send_loop(Parent, Sock);
+                {error, Reason} = ERROR ->
+                    ?SEV_ANNOUNCE_READY(Parent, send, ERROR),
+                    exit({send, Reason})
+            end;
+        {error, Reason} ->
+            exit({await_continue, Reason})
+    end.
+
+traffic_snr_tcp_client_init(Parent) ->
+    put(sname, "rclient"),
+    ?SEV_IPRINT("init"),
+    _MRef = erlang:monitor(process, Parent),
+    {ServerSA, Proto} = traffic_snr_tcp_client_await_start(Parent),
+    Domain   = maps:get(family, ServerSA),
+    Sock     = traffic_snr_tcp_client_create(Domain, Proto),
+    Path     = traffic_snr_tcp_client_bind(Sock, Domain),
+    {Sock, ServerSA, Path}.
+
+traffic_snr_tcp_client_await_start(Parent) ->
+    i("traffic_snr_tcp_client_await_start -> entry"),
+    ?SEV_AWAIT_START(Parent).
+
+traffic_snr_tcp_client_create(Domain, Proto) ->
+    i("traffic_snr_tcp_client_create -> entry"),
+    case socket:open(Domain, stream, Proto) of
+        {ok, Sock} ->
+            Sock;
+        {error, Reason} ->
+            exit({open_failed, Reason})
+    end.
+
+traffic_snr_tcp_client_bind(Sock, Domain) ->
+    i("traffic_snr_tcp_client_bind -> entry"),
+    LSA = which_local_socket_addr(Domain),
+    case socket:bind(Sock, LSA) of
+        {ok, _} ->
+            case socket:sockname(Sock) of
+                {ok, #{family := local, path := Path}} ->
+                    Path;
+                {ok, _} ->
+                    undefined;
+                {error, Reason1} ->
+                    exit({sockname, Reason1})
+            end;
+        {error, Reason} ->
+            exit({bind, Reason})
+    end.
+
+traffic_snr_tcp_client_announce_ready(Parent, Slogan) ->
+    ?SEV_ANNOUNCE_READY(Parent, Slogan).
+
+traffic_snr_tcp_client_await_continue(Parent, Slogan) ->
+    i("traffic_snr_tcp_client_await_continue -> entry"),
+    ?SEV_AWAIT_CONTINUE(Parent, parent, Slogan).
+
+traffic_snr_tcp_client_connect(Sock, ServerSA) ->
+    i("traffic_snr_tcp_client_connect -> entry"),
+    case socket:connect(Sock, ServerSA) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            exit({connect, Reason})
+    end.
+
+traffic_snr_tcp_client_close(Sock, Path) ->
+    i("traffic_snr_tcp_client_close -> entry"),
+    case socket:close(Sock) of
+        ok ->
+            unlink_path(Path),
+            ok;
+        {error, Reason} ->
+            ?SEV_EPRINT("failed closing: "
+                        "~n   Reason: ~p", [Reason]),
+            unlink_path(Path),
+            {error, {close, Reason}}
+    end.
+
+traffic_snr_tcp_client_await_terminate(Parent) ->
+    i("traffic_snr_tcp_client_await_terminate -> entry"),
+    case ?SEV_AWAIT_TERMINATE(Parent, parent) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            Reason
+    end.
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for IPv4.
+
+traffic_ping_pong_small_send_and_recv_tcp4(suite) ->
+    [];
+traffic_ping_pong_small_send_and_recv_tcp4(doc) ->
+    [];
+traffic_ping_pong_small_send_and_recv_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_send_and_recv_tcp4,
+           fun() ->
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_send_and_recv_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for IPv6.
+
+traffic_ping_pong_small_send_and_recv_tcp6(suite) ->
+    [];
+traffic_ping_pong_small_send_and_recv_tcp6(doc) ->
+    [];
+traffic_ping_pong_small_send_and_recv_tcp6(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_send_and_recv_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for Unix Domain (stream) socket.
+
+traffic_ping_pong_small_send_and_recv_tcpL(suite) ->
+    [];
+traffic_ping_pong_small_send_and_recv_tcpL(doc) ->
+    [];
+traffic_ping_pong_small_send_and_recv_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(15)),
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_send_and_recv_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for IPv4.
+
+traffic_ping_pong_medium_send_and_recv_tcp4(suite) ->
+    [];
+traffic_ping_pong_medium_send_and_recv_tcp4(doc) ->
+    [];
+traffic_ping_pong_medium_send_and_recv_tcp4(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_send_and_recv_tcp4,
+           fun() ->
+                   ?TT(?SECS(30)),
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for IPv6.
+
+traffic_ping_pong_medium_send_and_recv_tcp6(suite) ->
+    [];
+traffic_ping_pong_medium_send_and_recv_tcp6(doc) ->
+    [];
+traffic_ping_pong_medium_send_and_recv_tcp6(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_send_and_recv_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(30)),
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_send_and_recv_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for Unix Domain (stream) socket.
+
+traffic_ping_pong_medium_send_and_recv_tcpL(suite) ->
+    [];
+traffic_ping_pong_medium_send_and_recv_tcpL(doc) ->
+    [];
+traffic_ping_pong_medium_send_and_recv_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(30)),
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_send_and_recv_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_send_and_recv_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'large' message test case, for IPv4.
+
+traffic_ping_pong_large_send_and_recv_tcp4(suite) ->
+    [];
+traffic_ping_pong_large_send_and_recv_tcp4(doc) ->
+    [];
+traffic_ping_pong_large_send_and_recv_tcp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(45)),
+    Msg = l2b(?TPP_LARGE),
+    Num = ?TPP_LARGE_NUM,
+    tc_try(traffic_ping_pong_large_send_and_recv_tcp4,
+           fun() ->
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_send_and_recv_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'large' message test case, for IPv6.
+
+traffic_ping_pong_large_send_and_recv_tcp6(suite) ->
+    [];
+traffic_ping_pong_large_send_and_recv_tcp6(doc) ->
+    [];
+traffic_ping_pong_large_send_and_recv_tcp6(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_LARGE),
+    Num = ?TPP_LARGE_NUM,
+    tc_try(traffic_ping_pong_large_send_and_recv_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(45)),
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_send_and_recv_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the send and recv functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'large' message test case, for UNix Domain (stream) socket.
+
+traffic_ping_pong_large_send_and_recv_tcpL(suite) ->
+    [];
+traffic_ping_pong_large_send_and_recv_tcpL(doc) ->
+    [];
+traffic_ping_pong_large_send_and_recv_tcpL(_Config) when is_list(_Config) ->
+    ?TT(?SECS(45)),
+    Msg = l2b(?TPP_LARGE),
+    Num = ?TPP_LARGE_NUM,
+    tc_try(traffic_ping_pong_large_send_and_recv_tcpL,
+           fun() ->
+                   has_support_unix_domain_socket(),
+                   traffic_ping_pong_large_host_cond()
+           end,
+           fun() ->
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_send_and_recv_tcp(InitState)
+           end).
+
+%% This test case is a bit extreme and fails on some hosts
+%% (e.g. OpenIndiana Hipster), so exclude them.
+traffic_ping_pong_large_host_cond() ->
+    traffic_ping_pong_large_host_cond(os:type(), os:version()).
+
+traffic_ping_pong_large_host_cond({unix, sunos}, _) ->
+    skip("TC does not work on platform");
+traffic_ping_pong_large_host_cond(_, _) ->
+    ok.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendto and recvfrom 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for two different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for IPv4.
+
+traffic_ping_pong_small_sendto_and_recvfrom_udp4(suite) ->
+    [];
+traffic_ping_pong_small_sendto_and_recvfrom_udp4(doc) ->
+    [];
+traffic_ping_pong_small_sendto_and_recvfrom_udp4(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_sendto_and_recvfrom_udp4,
+           fun() ->
+                   ?TT(?SECS(45)),
+                   InitState = #{domain => inet,
+                                 proto  => udp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendto_and_recvfrom_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendto and recvfrom 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for two different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for IPv6.
+
+traffic_ping_pong_small_sendto_and_recvfrom_udp6(suite) ->
+    [];
+traffic_ping_pong_small_sendto_and_recvfrom_udp6(doc) ->
+    [];
+traffic_ping_pong_small_sendto_and_recvfrom_udp6(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_sendto_and_recvfrom_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(45)),
+                   InitState = #{domain => inet6,
+                                 proto  => udp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendto_and_recvfrom_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendto and recvfrom 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for two different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for Unix Domain (dgram) socket.
+
+traffic_ping_pong_small_sendto_and_recvfrom_udpL(suite) ->
+    [];
+traffic_ping_pong_small_sendto_and_recvfrom_udpL(doc) ->
+    [];
+traffic_ping_pong_small_sendto_and_recvfrom_udpL(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_sendto_and_recvfrom_udpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   ?TT(?SECS(45)),
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendto_and_recvfrom_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendto and recvfrom 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for two different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for IPv4.
+
+traffic_ping_pong_medium_sendto_and_recvfrom_udp4(suite) ->
+    [];
+traffic_ping_pong_medium_sendto_and_recvfrom_udp4(doc) ->
+    [];
+traffic_ping_pong_medium_sendto_and_recvfrom_udp4(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_sendto_and_recvfrom_udp4,
+           fun() ->
+                   ?TT(?SECS(45)),
+                   InitState = #{domain => inet,
+                                 proto  => udp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendto_and_recvfrom_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendto and recvfrom 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for two different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for IPv6.
+
+traffic_ping_pong_medium_sendto_and_recvfrom_udp6(suite) ->
+    [];
+traffic_ping_pong_medium_sendto_and_recvfrom_udp6(doc) ->
+    [];
+traffic_ping_pong_medium_sendto_and_recvfrom_udp6(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_sendto_and_recvfrom_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(45)),
+                   InitState = #{domain => inet6,
+                                 proto  => udp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendto_and_recvfrom_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendto and recvfrom 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for two different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for Unix Domain (dgram) socket.
+
+traffic_ping_pong_medium_sendto_and_recvfrom_udpL(suite) ->
+    [];
+traffic_ping_pong_medium_sendto_and_recvfrom_udpL(doc) ->
+    [];
+traffic_ping_pong_medium_sendto_and_recvfrom_udpL(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_sendto_and_recvfrom_udpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   ?TT(?SECS(45)),
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendto_and_recvfrom_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for IPv4.
+
+traffic_ping_pong_small_sendmsg_and_recvmsg_tcp4(suite) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_tcp4(doc) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_tcp4(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_sendmsg_and_recvmsg_tcp4,
+           fun() ->
+                   ?TT(?SECS(20)),
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for IPv6.
+
+traffic_ping_pong_small_sendmsg_and_recvmsg_tcp6(suite) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_tcp6(doc) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_tcp6(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_sendmsg_and_recvmsg_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(20)),
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for Unix Domain (stream) socket.
+
+traffic_ping_pong_small_sendmsg_and_recvmsg_tcpL(suite) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_tcpL(doc) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_tcpL(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_sendmsg_and_recvmsg_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   ?TT(?SECS(20)),
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for IPv4.
+
+traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp4(suite) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp4(doc) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp4(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp4,
+           fun() ->
+                   ?TT(?SECS(30)),
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for IPv6.
+
+traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp6(suite) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp6(doc) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp6(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_sendmsg_and_recvmsg_tcp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(30)),
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for Unix Domain (stream) socket.
+
+traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL(suite) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL(doc) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_sendmsg_and_recvmsg_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   ?TT(?SECS(30)),
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'large' message test case, for IPv4.
+
+traffic_ping_pong_large_sendmsg_and_recvmsg_tcp4(suite) ->
+    [];
+traffic_ping_pong_large_sendmsg_and_recvmsg_tcp4(doc) ->
+    [];
+traffic_ping_pong_large_sendmsg_and_recvmsg_tcp4(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_LARGE),
+    Num = ?TPP_LARGE_NUM,
+    tc_try(traffic_ping_pong_large_sendmsg_and_recvmsg_tcp4,
+           fun() -> traffic_ping_pong_large_sendmsg_and_recvmsg_cond() end,
+           fun() ->
+                   ?TT(?SECS(60)),
+                   InitState = #{domain => inet,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
+           end).
+
+
+traffic_ping_pong_large_sendmsg_and_recvmsg_cond() ->
+    traffic_ping_pong_large_sendmsg_and_recvmsg_cond(os:type(), os:version()).
+
+traffic_ping_pong_large_sendmsg_and_recvmsg_cond({unix, linux}, {M, _, _})
+  when (M < 3) ->
+    skip("TC may not work on this version");
+traffic_ping_pong_large_sendmsg_and_recvmsg_cond(_, _) ->
+    ok.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'large' message test case, for IPv6.
+
+traffic_ping_pong_large_sendmsg_and_recvmsg_tcp6(suite) ->
+    [];
+traffic_ping_pong_large_sendmsg_and_recvmsg_tcp6(doc) ->
+    [];
+traffic_ping_pong_large_sendmsg_and_recvmsg_tcp6(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_LARGE),
+    Num = ?TPP_LARGE_NUM,
+    tc_try(traffic_ping_pong_large_sendmsg_and_recvmsg_tcp6,
+           fun() ->
+                   has_support_ipv6(),
+                   traffic_ping_pong_large_sendmsg_and_recvmsg_cond()
+           end,
+           fun() ->
+                   ?TT(?SECS(60)),
+                   InitState = #{domain => inet6,
+                                 proto  => tcp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes), medium (8K) and large (8M).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'large' message test case, for Unix Domain (stream) socket.
+
+traffic_ping_pong_large_sendmsg_and_recvmsg_tcpL(suite) ->
+    [];
+traffic_ping_pong_large_sendmsg_and_recvmsg_tcpL(doc) ->
+    [];
+traffic_ping_pong_large_sendmsg_and_recvmsg_tcpL(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_LARGE),
+    Num = ?TPP_LARGE_NUM,
+    tc_try(traffic_ping_pong_large_sendmsg_and_recvmsg_tcpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   ?TT(?SECS(60)),
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for IPv4.
+
+traffic_ping_pong_small_sendmsg_and_recvmsg_udp4(suite) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_udp4(doc) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_udp4(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_sendmsg_and_recvmsg_udp4,
+           fun() ->
+                   ?TT(?SECS(60)),
+                   InitState = #{domain => inet,
+                                 proto  => udp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for IPv6.
+
+traffic_ping_pong_small_sendmsg_and_recvmsg_udp6(suite) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_udp6(doc) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_udp6(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_sendmsg_and_recvmsg_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(60)),
+                   InitState = #{domain => inet6,
+                                 proto  => udp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg functions
+%% by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'small' message test case, for Unix Domain (dgram) socket.
+
+traffic_ping_pong_small_sendmsg_and_recvmsg_udpL(suite) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_udpL(doc) ->
+    [];
+traffic_ping_pong_small_sendmsg_and_recvmsg_udpL(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_SMALL),
+    Num = ?TPP_SMALL_NUM,
+    tc_try(traffic_ping_pong_small_sendmsg_and_recvmsg_udpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   ?TT(?SECS(60)),
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for IPv4.
+
+traffic_ping_pong_medium_sendmsg_and_recvmsg_udp4(suite) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_udp4(doc) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_udp4(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_sendmsg_and_recvmsg_udp4,
+           fun() ->
+                   ?TT(?SECS(60)),
+                   InitState = #{domain => inet,
+                                 proto  => udp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_udp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for IPv6.
+
+traffic_ping_pong_medium_sendmsg_and_recvmsg_udp6(suite) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_udp6(doc) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_udp6(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_sendmsg_and_recvmsg_udp6,
+           fun() -> has_support_ipv6() end,
+           fun() ->
+                   ?TT(?SECS(60)),
+                   InitState = #{domain => inet6,
+                                 proto  => udp,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case is intended to test that the sendmsg and recvmsg 
+%% functions by repeatedly sending a meassage between two entities.
+%% The same basic test case is used for three different message sizes; 
+%% small (8 bytes) and medium (8K).
+%% The message is sent from A to B and then back again. This is 
+%% repeated a set number of times (more times the small the message).
+%% This is the 'medium' message test case, for Unix Domain (dgram) socket.
+
+traffic_ping_pong_medium_sendmsg_and_recvmsg_udpL(suite) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_udpL(doc) ->
+    [];
+traffic_ping_pong_medium_sendmsg_and_recvmsg_udpL(_Config) when is_list(_Config) ->
+    Msg = l2b(?TPP_MEDIUM),
+    Num = ?TPP_MEDIUM_NUM,
+    tc_try(traffic_ping_pong_medium_sendmsg_and_recvmsg_udpL,
+           fun() -> has_support_unix_domain_socket() end,
+           fun() ->
+                   ?TT(?SECS(60)),
+                   InitState = #{domain => local,
+                                 proto  => default,
+                                 msg    => Msg,
+                                 num    => Num},
+                   ok = traffic_ping_pong_sendmsg_and_recvmsg_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Ping-Pong for TCP
+
+traffic_ping_pong_send_and_recv_tcp(InitState) ->
+    Send = fun(Sock, Data) -> socket:send(Sock, Data) end,
+    Recv = fun(Sock, Sz)   -> socket:recv(Sock, Sz) end,
+    InitState2 = InitState#{send => Send, % Send function
+                            recv => Recv  % Receive function
+                           },
+    traffic_ping_pong_send_and_receive_tcp(InitState2).
+
+traffic_ping_pong_sendmsg_and_recvmsg_tcp(#{domain := local} = InitState) ->
+    Recv = fun(Sock, Sz)   -> 
+                   case socket:recvmsg(Sock, Sz, 0) of
+                       %% On some platforms, the address
+                       %% is *not* provided (e.g. FreeBSD)
+                       {ok, #{addr  := undefined,
+                              iov   := [Data]}} ->
+                           {ok, Data};
+                       %% On some platforms, the address
+                       %% *is* provided (e.g. linux)
+                       {ok, #{addr  := #{family := local},
+                              iov   := [Data]}} ->
+                           {ok, Data};
+                       {error, _} = ERROR ->
+                           ERROR
+                   end
+           end,
+    InitState2 = InitState#{recv => Recv},  % Receive function
+    traffic_ping_pong_sendmsg_and_recvmsg_tcp2(InitState2);
+traffic_ping_pong_sendmsg_and_recvmsg_tcp(InitState) ->
+    Recv = fun(Sock, Sz)   -> 
+                   case socket:recvmsg(Sock, Sz, 0) of
+                       {ok, #{addr  := undefined,
+                              iov   := [Data]}} ->
+                           {ok, Data};
+                       {error, _} = ERROR ->
+                           ERROR
+                   end
+           end,
+    InitState2 = InitState#{recv => Recv},  % Receive function
+    traffic_ping_pong_sendmsg_and_recvmsg_tcp2(InitState2).
+
+traffic_ping_pong_sendmsg_and_recvmsg_tcp2(InitState) ->
+    Send = fun(Sock, Data) when is_binary(Data) ->
+                   MsgHdr = #{iov => [Data]},
+                   socket:sendmsg(Sock, MsgHdr);
+              (Sock, Data) when is_list(Data) -> %% We assume iovec...
+                   MsgHdr = #{iov => Data},
+                   socket:sendmsg(Sock, MsgHdr)
+           end,
+    InitState2 = InitState#{send => Send}, % Send function
+    traffic_ping_pong_send_and_receive_tcp(InitState2).
+
+
+traffic_ping_pong_send_and_receive_tcp(#{msg := Msg} = InitState) ->
+    Fun = fun(Sock) -> 
+                  {ok, RcvSz} = socket:getopt(Sock, socket, rcvbuf),
+		  ?SEV_IPRINT("RcvBuf is ~p (needs atleast ~p)", 
+			      [RcvSz, 16+size(Msg)]),
+                  if (RcvSz < size(Msg)) ->
+                          NewRcvSz = 1024+size(Msg),
+                          case socket:setopt(Sock, socket, rcvbuf, NewRcvSz) of
+			      ok ->
+				  ok;
+			      {error, enobufs} ->
+				  skip(?F("Change ~w buffer size (to ~w) "
+                                          "not allowed", 
+                                          [rcvbuf, NewRcvSz]));
+			      {error, Reason1} ->
+				  ?FAIL({rcvbuf, Reason1})
+			  end;
+                     true ->
+                          ok
+                  end,
+                  {ok, SndSz} = socket:getopt(Sock, socket, sndbuf),
+		  ?SEV_IPRINT("SndBuf is ~p (needs atleast ~p)", 
+			      [SndSz, 16+size(Msg)]),
+                  if (SndSz < size(Msg)) ->
+                          NewSndSz = 1024+size(Msg),
+                          case socket:setopt(Sock, socket, sndbuf, NewSndSz) of
+			      ok ->
+				  ok;
+			      {error, enobufs} ->
+				  skip(?F("Change ~w buffer size (to ~w) "
+                                          "not allowed", 
+                                          [sndbuf, NewSndSz]));
+			      {error, Reason2} ->
+				  ?FAIL({sndbuf, Reason2})
+			  end;
+                     true ->
+                          ok
+                  end,
+                  ok = socket:setopt(Sock, otp, rcvbuf, {12, 1024})
+          end,
+    traffic_ping_pong_send_and_receive_tcp2(InitState#{buf_init => Fun}).
+
+traffic_ping_pong_send_and_receive_tcp2(InitState) ->
+    ServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create listen socket",
+           cmd  => fun(#{domain := Domain, proto := Proto} = State) ->
+                           case socket:open(Domain, stream, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{lsock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{domain := local,
+                         lsock  := LSock,
+                         lsa    := LSA} = _State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, _Port} ->
+                                   ok; % We do not care about the port for local
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{lsock := LSock, local_sa := LSA} = State) ->
+                           case socket:bind(LSock, LSA) of
+                               {ok, Port} ->
+                                   ?SEV_IPRINT("bound to port: ~w", [Port]),
+                                   {ok, State#{lport => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "maybe init buffers",
+           cmd  => fun(#{lsock := LSock, buf_init := BufInit} = _State) ->
+                           BufInit(LSock)
+                   end},
+         #{desc => "make listen socket",
+           cmd  => fun(#{lsock := LSock}) ->
+                           socket:listen(LSock)
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain := local,
+                         tester := Tester, local_sa := LSA}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, LSA),
+                           ok;
+                      (#{tester := Tester, local_sa := LSA, lport := Port}) ->
+                           ServerSA = LSA#{port => Port},
+                           ?SEV_ANNOUNCE_READY(Tester, init, ServerSA),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (accept)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, accept)
+                   end},
+         #{desc => "accept",
+           cmd  => fun(#{lsock := LSock} = State) ->
+                           case socket:accept(LSock) of
+                               {ok, Sock} ->
+                                   {ok, State#{csock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "create handler",
+           cmd  => fun(State) ->
+                           Handler = tpp_tcp_handler_create(),
+                           ?SEV_IPRINT("handler created: ~p", [Handler]),
+                           {ok, State#{handler => Handler}}
+                   end},
+         #{desc => "monitor handler",
+           cmd  => fun(#{handler := Handler} = _State) ->
+                           _MRef = erlang:monitor(process, Handler),
+                           ok
+                   end},
+         #{desc => "transfer connection socket ownership to handler",
+           cmd  => fun(#{handler := Handler, csock := Sock} = _State) ->
+                           socket:setopt(Sock, otp, controlling_process, Handler)
+                   end},
+         #{desc => "start handler",
+           cmd  => fun(#{handler  := Handler,
+                         csock    := Sock,
+                         send     := Send,
+                         recv     := Recv} = _State) ->
+                           ?SEV_ANNOUNCE_START(Handler, {Sock, Send, Recv}),
+                           ok
+                   end},
+         #{desc => "await handler ready (init)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = State) ->
+                           case ?SEV_AWAIT_READY(Handler, handler, init, 
+                                                 [{tester, Tester}]) of
+                               ok ->
+                                   {ok, maps:remove(csock, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (accept)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, accept),
+                           ok
+                   end},
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv, 
+                                               [{handler, Handler}])
+                   end},
+         #{desc => "order handler to recv",
+           cmd  => fun(#{handler := Handler} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Handler, recv),
+                           ok
+                   end},
+         #{desc => "await handler ready (recv)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = State) ->
+                           case ?SEV_AWAIT_READY(Handler, handler, recv, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   %% ?SEV_IPRINT("Result: ~p", [Result]),
+                                   {ok, State#{result => Result}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv)",
+           cmd  => fun(#{tester := Tester, 
+                         result := Result} = State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv, Result),
+                           {ok, maps:remove(result, State)}
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "stop handler",
+           cmd  => fun(#{handler := Handler}) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Handler),
+                           ok
+                   end},
+         #{desc => "await handler termination",
+           cmd  => fun(#{handler := Handler} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Handler),
+                           State1 = maps:remove(handler, State),
+                           {ok, State1}
+                   end},
+         #{desc => "close listen socket",
+           cmd  => fun(#{domain   := local,
+                         lsock    := Sock,
+                         local_sa := #{path := Path}} = State) ->
+                           (catch socket:close(Sock)),
+                           State1 =
+                               unlink_path(Path,
+                                           fun() -> 
+                                                   maps:remove(local_sa, State)
+                                           end,
+                                           fun() -> State end),
+                           {ok, maps:remove(lsock, State1)};
+                      (#{lsock := Sock} = State) ->
+                           (catch socket:close(Sock)),
+                           {ok, maps:remove(lsock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, ServerSA} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester    => Tester, 
+                                       server_sa => ServerSA}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "create node",
+           cmd  => fun(#{host := Host} = State) ->
+                           case start_node(Host, client) of
+                               {ok, Node} ->
+                                   ?SEV_IPRINT("(remote) client node ~p started", 
+                                               [Node]),
+                                   {ok, State#{node => Node}};
+                               {error, Reason} ->
+                                   {skip, Reason}
+                           end
+                   end},
+         #{desc => "monitor client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           true = erlang:monitor_node(Node, true),
+                           ok
+                   end},
+         #{desc => "create remote client",
+           cmd  => fun(#{node := Node} = State) ->
+                           Pid = tpp_tcp_client_create(Node),
+                           ?SEV_IPRINT("remote client created: ~p", [Pid]),
+                           {ok, State#{rclient => Pid}}
+                   end},
+         #{desc => "monitor remote client",
+           cmd  => fun(#{rclient := Pid}) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "order remote client to start",
+           cmd  => fun(#{rclient   := RClient,
+                         proto     := Proto,
+                         server_sa := ServerSA,
+                         buf_init  := BufInit,
+                         send      := Send,
+                         recv      := Recv}) ->
+                           ?SEV_ANNOUNCE_START(RClient, 
+                                               {ServerSA, Proto, BufInit,
+                                                Send, Recv}),
+                           ok
+                   end},
+         #{desc => "await remote client ready",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := RClient} = _State) ->
+                           ?SEV_AWAIT_READY(RClient, rclient, init, 
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := RClient} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, connect, 
+                                               [{rclient, RClient}]),
+                           ok
+                   end},
+         #{desc => "order remote client to continue (connect)",
+           cmd  => fun(#{rclient := RClient}) ->
+                           ?SEV_ANNOUNCE_CONTINUE(RClient, connect),
+                           ok
+                   end},
+         #{desc => "await remote client ready (connect)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := RClient} = _State) ->
+                           ?SEV_AWAIT_READY(RClient, rclient, connect, 
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (connect)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, connect),
+                           ok
+                   end},
+         #{desc => "await continue (send)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := RClient} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, 
+                                               send, 
+                                               [{rclient, RClient}])
+                   end},
+         #{desc => "order remote client to continue (send)",
+           cmd  => fun(#{rclient := RClient,
+                         msg     := Msg,
+                         num     := Num} = State) ->
+                           Data = {Msg, Num},
+                           ?SEV_ANNOUNCE_CONTINUE(RClient, send, Data),
+                           {ok, maps:remove(data, State)}
+                   end},
+         #{desc => "await remote client ready (send)",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := RClient} = State) ->
+                           case ?SEV_AWAIT_READY(RClient, rclient, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   %% ?SEV_IPRINT("remote client result: "
+                                   %%             "~n   ~p", [Result]),
+                                   {ok, State#{result => Result}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (send)",
+           cmd  => fun(#{tester := Tester, result := Result} = State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send, Result),
+                           {ok, maps:remove(result, State)}
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester  := Tester, 
+                         rclient := RClient} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester,
+                                                     [{rclient, RClient}]) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "stop remote client",
+           cmd  => fun(#{rclient := RClient}) ->
+                           ?SEV_ANNOUNCE_TERMINATE(RClient),
+                           ok
+                   end},
+         #{desc => "await remote client termination",
+           cmd  => fun(#{rclient := RClient} = State) ->
+                           ?SEV_AWAIT_TERMINATION(RClient),
+                           State1 = maps:remove(rclient, State),
+                           {ok, State1}
+                   end},
+         #{desc => "stop client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           stop_node(Node)
+                   end},
+         #{desc => "await client node termination",
+           cmd  => fun(#{node := Node} = State) ->
+                           receive
+                               {nodedown, Node} ->
+                                   {ok, maps:remove(node, State)}
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, ServerSA} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client    := Pid, 
+                         server_sa := ServerSA} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, ServerSA),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+ 
+         %% The actual test
+         #{desc => "order server continue (accept)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, accept),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client continue (connect)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, connect),
+                           ok
+                   end},
+         #{desc => "await server ready (accept)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Server, server, accept,
+                                            [{client, Client}]),
+                           ok
+                   end},
+         #{desc => "await client ready (connect)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           ?SEV_AWAIT_READY(Client, client, connect, 
+                                            [{server, Server}])
+                   end},
+         #{desc => "order server continue (recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client continue (send)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, send),
+                           ok
+                   end},
+         #{desc => "await client ready (send)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = State) ->
+                           case ?SEV_AWAIT_READY(Client, client, send, 
+                                                 [{server, Server}]) of
+                               {ok, {_, _, _, _} = Result} ->
+                                   ?SEV_IPRINT("client result: "
+                                               "~n   ~p", [Result]),
+                                   {ok, State#{client_result => Result}};
+                               {ok, BadResult} ->
+                                   ?SEV_EPRINT("client result: "
+                                               "~n   ~p", [BadResult]),
+                                   {error, {invalid_client_result, BadResult}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await server ready (recv)",
+           cmd  => fun(#{server := Server,
+                         client := Client,
+                         num    := Num} = State) ->
+                           case ?SEV_AWAIT_READY(Server, server, recv,
+                                                 [{client, Client}]) of
+                               {ok, {Num, _, _, _, _} = Result} ->
+                                   ?SEV_IPRINT("server result: "
+                                               "~n   ~p", [Result]),
+                                   Result2 = erlang:delete_element(1, Result),
+                                   {ok, State#{server_result => Result2}};
+                               {ok, BadResult} ->
+                                   ?SEV_EPRINT("bad server result: "
+                                               "~n   ~p", [BadResult]),
+                                   {error, {invalid_server_result, BadResult}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "present result",
+           cmd  => fun(#{server_result := SRes,
+                         client_result := CRes,
+                         num           := Num} = State) ->
+                           {SSent, SReceived, SStart, SStop} = SRes,
+                           {CSent, CReceived, CStart, CStop} = CRes,
+                           STime = tdiff(SStart, SStop),
+                           CTime = tdiff(CStart, CStop),
+                           %% Note that the sizes we are counting is only 
+                           %% the "data" part of the messages. There is also
+                           %% fixed header for each message, which of cource
+                           %% is small for the large messages, but comparatively
+                           %% big for the small messages!
+                           ?SEV_IPRINT("Results: ~w messages exchanged"
+                                       "~n   Server: ~w msec"
+                                       "~n      ~.2f msec/message (roundtrip)"
+                                       "~n      ~.2f messages/msec (roundtrip)"
+                                       "~n      ~w bytes/msec sent"
+                                       "~n      ~w bytes/msec received"
+                                       "~n   Client: ~w msec"
+                                       "~n      ~.2f msec/message (roundtrip)"
+                                       "~n      ~.2f messages/msec (roundtrip)"
+                                       "~n      ~w bytes/msec sent"
+                                       "~n      ~w bytes/msec received",
+                                       [Num,
+                                        STime,
+                                        STime / Num,
+                                        Num / STime,
+                                        SSent div STime,
+                                        SReceived div STime,
+                                        CTime,
+                                        CTime / Num,
+                                        Num / CTime,
+                                        CSent div CTime,
+                                        CReceived div CTime]),
+                           State1 = maps:remove(server_result, State),
+                           State2 = maps:remove(client_result, State1),
+                           {ok, State2}
+                   end},
+
+         %% Terminations
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(client, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    ServerInitState = #{domain   => maps:get(domain,   InitState),
+                        proto    => maps:get(proto,    InitState),
+                        recv     => maps:get(recv,     InitState),
+                        send     => maps:get(send,     InitState),
+                        buf_init => maps:get(buf_init, InitState)},
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator(s)"),
+    ClientInitState = InitState#{host => local_host()},
+    Client = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid,
+                        num    => maps:get(num, InitState)},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+    
+
+tpp_tcp_handler_create() ->
+    Self = self(),
+    erlang:spawn(fun() -> tpp_tcp_handler(Self) end).
+
+tpp_tcp_handler(Parent) ->
+    tpp_tcp_handler_init(Parent),
+    {Sock, Send, Recv} = tpp_tcp_handler_await_start(Parent),
+    tpp_tcp_handler_announce_ready(Parent, init),
+    tpp_tcp_handler_await_continue(Parent, recv),
+    Result = tpp_tcp_handler_msg_exchange(Sock, Send, Recv),
+    tpp_tcp_handler_announce_ready(Parent, recv, Result),
+    Reason = tpp_tcp_handler_await_terminate(Parent),
+    ?SEV_IPRINT("terminating"),
+    exit(Reason).
+
+tpp_tcp_handler_init(Parent) ->
+    put(sname, "handler"),
+    ?SEV_IPRINT("init"),
+    _MRef = erlang:monitor(process, Parent),
+    ok.
+
+tpp_tcp_handler_await_start(Parent) ->
+    ?SEV_IPRINT("await start"),
+    ?SEV_AWAIT_START(Parent).
+
+tpp_tcp_handler_announce_ready(Parent, Slogan) ->
+    ?SEV_IPRINT("announce ready (~p)", [Slogan]),
+    ?SEV_ANNOUNCE_READY(Parent, Slogan).
+tpp_tcp_handler_announce_ready(Parent, Slogan, Extra) ->
+    ?SEV_IPRINT("announce ready (~p)", [Slogan]),
+    ?SEV_ANNOUNCE_READY(Parent, Slogan, Extra).
+
+tpp_tcp_handler_await_continue(Parent, Slogan) ->
+    ?SEV_IPRINT("await continue (~p)", [Slogan]),
+    case ?SEV_AWAIT_CONTINUE(Parent, parent, Slogan) of
+        ok ->
+            %% ?SEV_IPRINT("continue (~p): ok", [Slogan]),
+            ok;
+        {error, Reason} ->
+            ?SEV_EPRINT("continue (~p): error"
+                        "~n   ~p", [Slogan, Reason]),
+            exit({continue, Slogan, Reason})
+    end.
+
+tpp_tcp_handler_await_terminate(Parent) ->
+    ?SEV_IPRINT("await terminate"),
+    case ?SEV_AWAIT_TERMINATE(Parent, parent) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            Reason
+    end.
+
+tpp_tcp_handler_msg_exchange(Sock, Send, Recv) ->
+    tpp_tcp_handler_msg_exchange_loop(Sock, Send, Recv, 0, 0, 0, undefined).
+
+tpp_tcp_handler_msg_exchange_loop(Sock, Send, Recv, N, Sent, Received, Start) ->
+    %% ?SEV_IPRINT("[~w] try receive", [N]),
+    case tpp_tcp_recv_req(Sock, Recv) of
+        {ok, Msg, RecvSz} ->
+            NewStart = if (Start =:= undefined) -> ?LIB:timestamp(); 
+                          true -> Start end,
+            %% ?SEV_IPRINT("[~w] received - now try send", [N]),
+            case tpp_tcp_send_rep(Sock, Send, Msg) of
+                {ok, SendSz} ->
+                    tpp_tcp_handler_msg_exchange_loop(Sock, Send, Recv,
+                                                      N+1,
+                                                      Sent+SendSz,
+                                                      Received+RecvSz,
+                                                      NewStart);
+                {error, SReason} ->
+                    ?SEV_EPRINT("send (~w): ~p", [N, SReason]),
+                    exit({send, SReason, N})
+            end;
+        {error, closed} ->
+            ?SEV_IPRINT("closed - we are done: ~w, ~w, ~w", [N, Sent, Received]),
+            Stop = ?LIB:timestamp(),
+            {N, Sent, Received, Start, Stop};
+        {error, RReason} ->
+            ?SEV_EPRINT("recv (~w): ~p", [N, RReason]),
+            exit({recv, RReason, N})
+    end.
+            
+%% The (remote) client process
+
+tpp_tcp_client_create(Node) ->
+    Self = self(),
+    Fun  = fun() -> tpp_tcp_client(Self) end,
+    erlang:spawn(Node, Fun).
+
+tpp_tcp_client(Parent) ->
+    tpp_tcp_client_init(Parent),
+    {ServerSA, Proto, BufInit, Send, Recv} = tpp_tcp_client_await_start(Parent),
+    Domain   = maps:get(family, ServerSA),
+    Sock     = tpp_tcp_client_sock_open(Domain, Proto, BufInit),
+    Path     = tpp_tcp_client_sock_bind(Sock, Domain),
+    tpp_tcp_client_announce_ready(Parent, init),
+    tpp_tcp_client_await_continue(Parent, connect),
+    tpp_tcp_client_sock_connect(Sock, ServerSA),
+    tpp_tcp_client_announce_ready(Parent, connect),
+    {InitMsg, Num} = tpp_tcp_client_await_continue(Parent, send),
+    Result = tpp_tcp_client_msg_exchange(Sock, Send, Recv, InitMsg, Num),
+    tpp_tcp_client_announce_ready(Parent, send, Result),
+    Reason = tpp_tcp_client_await_terminate(Parent),
+    tpp_tcp_client_sock_close(Sock, Path),
+    ?SEV_IPRINT("terminating"),
+    exit(Reason).
+
+tpp_tcp_client_init(Parent) ->
+    put(sname, "rclient"),
+    ?SEV_IPRINT("init"),
+    _MRef = erlang:monitor(process, Parent),
+    ok.
+
+tpp_tcp_client_await_start(Parent) ->
+    ?SEV_IPRINT("await start"),
+    ?SEV_AWAIT_START(Parent).
+
+tpp_tcp_client_announce_ready(Parent, Slogan) ->
+    ?SEV_IPRINT("announce ready (~p)", [Slogan]),
+    ?SEV_ANNOUNCE_READY(Parent, Slogan).
+tpp_tcp_client_announce_ready(Parent, Slogan, Extra) ->
+    ?SEV_IPRINT("announce ready (~p): ~p", [Slogan, Extra]),
+    ?SEV_ANNOUNCE_READY(Parent, Slogan, Extra).
+
+tpp_tcp_client_await_continue(Parent, Slogan) ->
+    ?SEV_IPRINT("await continue (~p)", [Slogan]),
+    case ?SEV_AWAIT_CONTINUE(Parent, parent, Slogan) of
+        ok ->
+            ?SEV_IPRINT("continue (~p): ok", [Slogan]),
+            ok;
+        {ok, Data} ->
+            ?SEV_IPRINT("continue (~p): ok with data", [Slogan]),
+            Data;
+        {error, Reason} ->
+            ?SEV_EPRINT("continue (~p): error"
+                        "~n   ~p", [Slogan, Reason]),
+            exit({continue, Slogan, Reason})
+    end.
+
+tpp_tcp_client_await_terminate(Parent) ->
+    ?SEV_IPRINT("await terminate"),
+    case ?SEV_AWAIT_TERMINATE(Parent, parent) of
+        ok ->
+            ?SEV_IPRINT("termination received: normal"),
+            normal;
+        {error, Reason} ->
+            ?SEV_IPRINT("termination received: ~w", [Reason]),
+            Reason
+    end.
+
+tpp_tcp_client_msg_exchange(Sock, Send, Recv, InitMsg, Num) ->
+    Start = ?LIB:timestamp(),
+    tpp_tcp_client_msg_exchange_loop(Sock, Send, Recv, InitMsg, 
+                                     Num, 0, 0, 0, Start).
+
+tpp_tcp_client_msg_exchange_loop(Sock, _Send, _Recv, _Msg,
+                                 Num, Num, Sent, Received,
+                                 Start) ->
+    Stop = ?LIB:timestamp(),
+    case socket:close(Sock) of
+        ok ->
+            {Sent, Received, Start, Stop};
+        {error, Reason} ->
+            exit({failed_closing, Reason})
+    end;
+tpp_tcp_client_msg_exchange_loop(Sock, Send, Recv, Data, 
+                                 Num, N, Sent, Received, Start) ->
+    %% d("tpp_tcp_client_msg_exchange_loop(~w,~w) try send ~w", [Num,N,size(Data)]),
+    case tpp_tcp_send_req(Sock, Send, Data) of
+        {ok, SendSz} ->
+            %% d("tpp_tcp_client_msg_exchange_loop(~w,~w) sent - "
+            %%   "now try recv", [Num,N]),
+            case tpp_tcp_recv_rep(Sock, Recv) of
+                {ok, NewData, RecvSz} ->
+                    tpp_tcp_client_msg_exchange_loop(Sock, Send, Recv,
+                                                     NewData, Num, N+1,
+                                                     Sent+SendSz, 
+                                                     Received+RecvSz, 
+                                                     Start);
+                {error, RReason} ->
+                    ?SEV_EPRINT("recv (~w of ~w): ~p: "
+                                "~n   ~p", [N, Num, RReason, mq()]),
+                    exit({recv, RReason, N})
+            end;
+        {error, SReason} ->
+            ?SEV_EPRINT("send (~w of ~w): ~p"
+                        "~n   ~p", [N, Num, SReason, mq()]),
+            exit({send, SReason, N})
+    end.
+
+tpp_tcp_client_sock_open(Domain, Proto, BufInit) ->
+    case socket:open(Domain, stream, Proto) of
+        {ok, Sock} ->
+            ok = BufInit(Sock),
+            Sock;
+        {error, Reason} ->
+            exit({open_failed, Reason})
+    end.
+
+tpp_tcp_client_sock_bind(Sock, Domain) ->
+    LSA = which_local_socket_addr(Domain),
+    case socket:bind(Sock, LSA) of
+        {ok, _} ->
+            case socket:sockname(Sock) of
+                {ok, #{family := local, path := Path}} ->
+                    Path;
+                {ok, _} ->
+                    undefined;
+                {error, Reason1} ->
+                    exit({sockname, Reason1})
+            end;
+        {error, Reason2} ->
+            exit({bind, Reason2})
+    end.
+
+tpp_tcp_client_sock_connect(Sock, ServerSA) ->
+    case socket:connect(Sock, ServerSA) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            exit({connect, Reason})
+    end.
+
+tpp_tcp_client_sock_close(Sock, Path) ->
+    case socket:close(Sock) of
+        ok ->
+            unlink_path(Path),
+            ok;
+        {error, Reason} ->
+            ?SEV_EPRINT("failed closing: "
+                        "~n   Reason: ~p", [Reason]),
+            unlink_path(Path),
+            {error, {close, Reason}}
+    end.
+
+    
+    
+-define(TPP_REQUEST, 1).
+-define(TPP_REPLY,   2).
+
+tpp_tcp_recv_req(Sock, Recv) ->
+    tpp_tcp_recv(Sock, Recv, ?TPP_REQUEST).
+
+tpp_tcp_recv_rep(Sock, Recv) ->
+    tpp_tcp_recv(Sock, Recv, ?TPP_REPLY).
+
+tpp_tcp_recv(Sock, Recv, Tag) ->
+    case Recv(Sock, 0) of
+        {ok, <<Tag:32/integer, Sz:32/integer, Data/binary>> = Msg} 
+          when (Sz =:= size(Data)) ->
+            %% We got it all
+            {ok, Data, size(Msg)};
+        {ok, <<Tag:32/integer, Sz:32/integer, Data/binary>> = Msg} ->
+            Remains = Sz - size(Data),
+            tpp_tcp_recv(Sock, Recv, Tag, Remains, size(Msg), [Data]);
+        {ok, <<Tag:32/integer, _/binary>>} ->
+            {error, {invalid_msg_tag, Tag}};
+        {error, _R} = ERROR ->
+            ERROR
+    end.
+
+tpp_tcp_recv(Sock, Recv, Tag, Remaining, AccSz, Acc) ->
+    case Recv(Sock, Remaining) of
+        {ok, Data} when (Remaining =:= size(Data)) ->
+            %% We got the rest
+            TotSz = AccSz + size(Data),
+            {ok, erlang:iolist_to_binary(lists:reverse([Data | Acc])), TotSz};
+        {ok, Data} when (Remaining > size(Data)) ->
+            tpp_tcp_recv(Sock, Recv, Tag, 
+                         Remaining - size(Data), AccSz + size(Data),     
+                         [Data | Acc]);
+        {error, _R} = ERROR ->
+            ERROR
+    end.
+                                                         
+            
+tpp_tcp_send_req(Sock, Send, Data) ->
+    tpp_tcp_send(Sock, Send, ?TPP_REQUEST, Data).
+
+tpp_tcp_send_rep(Sock, Send, Data) ->
+    tpp_tcp_send(Sock, Send, ?TPP_REPLY, Data).
+
+tpp_tcp_send(Sock, Send, Tag, Data) ->
+    DataSz = size(Data),
+    Msg    = <<Tag:32/integer, DataSz:32/integer, Data/binary>>,
+    tpp_tcp_send_msg(Sock, Send, Msg, 0).
+
+tpp_tcp_send_msg(Sock, Send, Msg, AccSz) when is_binary(Msg) ->
+    case Send(Sock, Msg) of
+        ok ->
+            {ok, AccSz+size(Msg)};
+        {ok, Rest} -> % This is an IOVec
+            RestBin = list_to_binary(Rest),
+            tpp_tcp_send_msg(Sock, Send, RestBin, AccSz+(size(Msg)-size(RestBin)));
+        {error, _} = ERROR ->
+            ERROR
+    end.
+    
+
+%% size_of_data(Data) when is_binary(Data) ->
+%%     size(Data);
+%% size_of_data(Data) when is_list(Data) ->
+%%     size_of_iovec(Data, 0).
+
+%% size_of_iovec([], Sz) ->
+%%     Sz;
+%% size_of_iovec([B|IOVec], Sz) ->
+%%     size_of_iovec(IOVec, Sz+size(B)).
+
+mq() ->
+    mq(self()).
+
+mq(Pid) when is_pid(Pid) ->
+    Tag = messages,
+    {Tag, Msgs} = process_info(Pid, Tag),
+    Msgs.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Ping-Pong for UDP
+
+traffic_ping_pong_sendto_and_recvfrom_udp(InitState) ->
+    Send = fun(Sock, Data, Dest) ->
+                   socket:sendto(Sock, Data, Dest)
+           end,
+    Recv = fun(Sock, Sz)         ->
+                   socket:recvfrom(Sock, Sz)
+           end,
+    InitState2 = InitState#{send => Send, % Send function
+                            recv => Recv  % Receive function
+                           },
+    traffic_ping_pong_send_and_receive_udp(InitState2).
+
+traffic_ping_pong_sendmsg_and_recvmsg_udp(InitState) ->
+    Send = fun(Sock, Data, Dest) when is_binary(Data) ->
+                   MsgHdr = #{addr => Dest, iov => [Data]},
+                   socket:sendmsg(Sock, MsgHdr);
+              (Sock, Data, Dest) when is_list(Data) -> %% We assume iovec...
+                   MsgHdr = #{addr => Dest, iov => Data},
+                   socket:sendmsg(Sock, MsgHdr)
+           end,
+    Recv = fun(Sock, Sz)   ->
+                   case socket:recvmsg(Sock, Sz, 0) of
+                       {ok, #{addr  := Source,
+                              iov   := [Data]}} ->
+                           {ok, {Source, Data}};
+                       {error, _} = ERROR ->
+                           ERROR
+                   end
+           end,
+    InitState2 = InitState#{send => Send, % Send function
+                            recv => Recv  % Receive function
+                           },
+    traffic_ping_pong_send_and_receive_udp(InitState2).
+
+
+traffic_ping_pong_send_and_receive_udp(#{msg := Msg} = InitState) ->
+    Fun = fun(Sock) -> 
+                  {ok, RcvSz} = socket:getopt(Sock, socket, rcvbuf),
+                  if (RcvSz =< (8+size(Msg))) ->
+                          i("adjust socket rcvbuf buffer size"),
+                          ok = socket:setopt(Sock, socket, rcvbuf, 1024+size(Msg));
+                     true ->
+                          ok
+                  end,
+                  {ok, SndSz} = socket:getopt(Sock, socket, sndbuf),
+                  if (SndSz =< (8+size(Msg))) ->
+                          i("adjust socket sndbuf buffer size"),
+                          ok = socket:setopt(Sock, socket, sndbuf, 1024+size(Msg));
+                     true ->
+                          ok
+                  end,
+                  {ok, OtpRcvBuf} = socket:getopt(Sock, otp, rcvbuf),
+                  if
+                      (OtpRcvBuf =< (8+size(Msg))) ->
+                          i("adjust otp rcvbuf buffer size"),
+                          ok = socket:setopt(Sock, otp, rcvbuf, 1024+size(Msg));
+                      true ->
+                          ok
+                  end
+          end,
+    traffic_ping_pong_send_and_receive_udp2(InitState#{buf_init => Fun}).
+
+traffic_ping_pong_send_and_receive_udp2(InitState) ->
+    ServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LSA = which_local_socket_addr(Domain),
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain, proto := Proto} = State) ->
+                           case socket:open(Domain, dgram, Proto) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind to local address",
+           cmd  => fun(#{domain := local,
+                         sock := Sock, local_sa := LSA} = _State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, _} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{sock := Sock, local_sa := LSA} = State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{port => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "maybe init buffers",
+           cmd  => fun(#{sock := Sock, buf_init := BufInit} = _State) ->
+                           BufInit(Sock)
+                   end},
+         #{desc => "create handler",
+           cmd  => fun(State) ->
+                           Handler = tpp_udp_server_handler_create(),
+                           ?SEV_IPRINT("handler created: ~p", [Handler]),
+                           {ok, State#{handler => Handler}}
+                   end},
+         #{desc => "monitor handler",
+           cmd  => fun(#{handler := Handler} = _State) ->
+                           _MRef = erlang:monitor(process, Handler),
+                           ok
+                   end},
+         #{desc => "start handler",
+           cmd  => fun(#{handler := Handler,
+                         sock    := Sock,
+                         send    := Send,
+                         recv    := Recv} = _State) ->
+                           ?SEV_ANNOUNCE_START(Handler, {Sock, Send, Recv}),
+                           ok
+                   end},
+         #{desc => "await handler ready (init)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = State) ->
+                           case ?SEV_AWAIT_READY(Handler, handler, init, 
+                                                 [{tester, Tester}]) of
+                               ok ->
+                                   {ok, maps:remove(csock, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain := local,
+                         tester := Tester, local_sa := LSA}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, LSA),
+                           ok;
+                      (#{tester := Tester, local_sa := LSA, port := Port}) ->
+                           ServerSA = LSA#{port => Port},
+                           ?SEV_ANNOUNCE_READY(Tester, init, ServerSA),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv, 
+                                               [{handler, Handler}])
+                   end},
+         #{desc => "order handler to recv",
+           cmd  => fun(#{handler := Handler,
+                         sock    := _Sock} = _State) ->
+                           %% socket:setopt(Sock, otp, debug, true),
+                           ?SEV_ANNOUNCE_CONTINUE(Handler, recv),
+                           ok
+                   end},
+         #{desc => "await continue (close)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, close, 
+                                               [{handler, Handler}])
+                   end},
+
+         ?SEV_SLEEP(?SECS(1)),
+
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           %% socket:setopt(Sock, otp, debug, true),
+                           case socket:close(Sock) of
+                               ok ->
+                                   {ok, maps:remove(sock, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "(maybe) unlink socket",
+           cmd  => fun(#{domain   := local,
+                         local_sa := #{path := Path}} = State) ->
+                           unlink_path(Path,
+                                       fun() ->
+                                               {ok, maps:remove(local_sa, State)}
+                                       end,
+                                       fun() ->
+                                               ok
+                                       end);
+                      (_) ->
+                           ok
+                   end},
+         #{desc => "announce ready (close)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, close),
+                           ok
+                   end},
+         #{desc => "await handler ready (recv)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = State) ->
+                           case ?SEV_AWAIT_READY(Handler, handler, recv, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   %% ?SEV_IPRINT("Result: ~p", [Result]),
+                                   {ok, State#{result => Result}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv)",
+           cmd  => fun(#{tester := Tester, 
+                         result := Result} = State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv, Result),
+                           {ok, maps:remove(result, State)}
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "stop handler",
+           cmd  => fun(#{handler := Handler}) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Handler),
+                           ok
+                   end},
+         #{desc => "await handler termination",
+           cmd  => fun(#{handler := Handler} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Handler),
+                           State1 = maps:remove(handler, State),
+                           {ok, State1}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           {Tester, ServerSA} = ?SEV_AWAIT_START(),
+                           {ok, State#{tester    => Tester, 
+                                       server_sa => ServerSA}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "create node",
+           cmd  => fun(#{host := Host} = State) ->
+                           case start_node(Host, client) of
+                               {ok, Node} ->
+                                   ?SEV_IPRINT("(remote) client node ~p started", 
+                                               [Node]),
+                                   {ok, State#{node => Node}};
+                               {error, Reason} ->
+                                   {skip, Reason}
+                           end
+                   end},
+         #{desc => "monitor client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           true = erlang:monitor_node(Node, true),
+                           ok
+                   end},
+         #{desc => "create (remote) handler",
+           cmd  => fun(#{node := Node} = State) ->
+                           Pid = tpp_udp_client_handler_create(Node),
+                           ?SEV_IPRINT("handler created: ~p", [Pid]),
+                           {ok, State#{handler => Pid}}
+                   end},
+         #{desc => "monitor remote handler",
+           cmd  => fun(#{handler := Pid}) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "order remote handler to start",
+           cmd  => fun(#{handler   := Handler,
+                         server_sa := ServerSA,
+                         proto     := Proto,
+                         buf_init  := BufInit,
+                         send      := Send,
+                         recv      := Recv}) ->
+                           ?SEV_ANNOUNCE_START(Handler, 
+                                               {ServerSA, Proto, BufInit,
+                                                Send, Recv}),
+                           ok
+                   end},
+         #{desc => "await (remote) handler ready",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = _State) ->
+                           ?SEV_AWAIT_READY(Handler, handler, init, 
+                                            [{tester, Tester}])
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (send)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, 
+                                               send, 
+                                               [{handler, Handler}])
+                   end},
+         #{desc => "order handler to continue (send)",
+           cmd  => fun(#{handler := Handler,
+                         msg     := Msg,
+                         num     := Num} = State) ->
+                           Data = {Msg, Num},
+                           ?SEV_ANNOUNCE_CONTINUE(Handler, send, Data),
+                           {ok, maps:remove(data, State)}
+                   end},
+         #{desc => "await remote handler ready (send)",
+           cmd  => fun(#{tester  := Tester,
+                         handler := Handler} = State) ->
+                           case ?SEV_AWAIT_READY(Handler, handler, send, 
+                                                 [{tester, Tester}]) of
+                               {ok, Result} ->
+                                   %% ?SEV_IPRINT("remote client result: "
+                                   %%             "~n   ~p", [Result]),
+                                   {ok, State#{result => Result}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (send)",
+           cmd  => fun(#{tester := Tester, result := Result} = State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, send, Result),
+                           {ok, maps:remove(result, State)}
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester  := Tester, 
+                         handler := Handler} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester,
+                                                     [{handler, Handler}]) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "stop (remote) handler",
+           cmd  => fun(#{handler := Handler}) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Handler),
+                           ok
+                   end},
+         #{desc => "await (remote) handler termination",
+           cmd  => fun(#{handler := Handler} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Handler),
+                           State1 = maps:remove(handler, State),
+                           {ok, State1}
+                   end},
+         #{desc => "stop client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           stop_node(Node)
+                   end},
+         #{desc => "await client node termination",
+           cmd  => fun(#{node := Node} = State) ->
+                           receive
+                               {nodedown, Node} ->
+                                   {ok, maps:remove(node, State)}
+                           end
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, ServerSA} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{client    := Pid, 
+                         server_sa := ServerSA} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, ServerSA),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, client, init)
+                   end},
+ 
+         %% The actual test
+         #{desc => "order server continue (recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         ?SEV_SLEEP(?SECS(1)),
+         #{desc => "order client continue (send)",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, send),
+                           ok
+                   end},
+         #{desc => "await client ready (send)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = State) ->
+                           case ?SEV_AWAIT_READY(Client, client, send, 
+                                                 [{server, Server}]) of
+                               {ok, {_, _, _, _} = Result} ->
+                                   ?SEV_IPRINT("client result: "
+                                               "~n   ~p", [Result]),
+                                   {ok, State#{client_result => Result}};
+                               {ok, BadResult} ->
+                                   ?SEV_EPRINT("client result: "
+                                               "~n   ~p", [BadResult]),
+                                   {error, {invalid_client_result, BadResult}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order server continue (close)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, close),
+                           ok
+                   end},
+         #{desc => "await server ready (close)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, close)
+                   end},
+         %% Because of the way we control the server, there is no real 
+         %% point in collecting statistics from it (the time will include
+         %% our communication with it).
+         #{desc => "await server ready (recv)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = _State) ->
+                           case ?SEV_AWAIT_READY(Server, server, recv,
+                                                 [{client, Client}]) of
+                               {ok, _Result} ->
+                                   ok;
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "present result",
+           cmd  => fun(#{client_result := CRes,
+                         num           := Num} = State) ->
+                           {CSent, CReceived, CStart, CStop} = CRes,
+                           CTime = tdiff(CStart, CStop),
+                           %% Note that the sizes we are counting is only 
+                           %% the "data" part of the messages. There is also
+                           %% fixed header for each message, which of cource
+                           %% is small for the large messages, but comparatively
+                           %% big for the small messages!
+                           ?SEV_IPRINT("Results: ~w messages exchanged"
+                                       "~n   Client: ~w msec"
+                                       "~n      ~.2f msec/message (roundtrip)"
+                                       "~n      ~.2f messages/msec (roundtrip)"
+                                       "~n      ~w bytes/msec sent"
+                                       "~n      ~w bytes/msec received",
+                                       [Num,
+                                        CTime,
+                                        CTime / Num,
+                                        Num / CTime,
+                                        CSent div CTime,
+                                        CReceived div CTime]),
+                           State1 = maps:remove(client_result, State),
+                           {ok, State1}
+                   end},
+
+         %% Terminations
+         #{desc => "order client to terminate",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await client termination",
+           cmd  => fun(#{client := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(client, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    i("start server evaluator"),
+    ServerInitState = #{domain   => maps:get(domain,   InitState),
+                        proto    => maps:get(proto,    InitState),
+                        recv     => maps:get(recv,     InitState),
+                        send     => maps:get(send,     InitState),
+                        buf_init => maps:get(buf_init, InitState)},
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator(s)"),
+    ClientInitState = InitState#{host => local_host()},
+    Client = ?SEV_START("client", ClientSeq, ClientInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server => Server#ev.pid,
+                        client => Client#ev.pid,
+                        num    => maps:get(num, InitState)},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+%% Server side handler process
+%% We don't actually need a separate process for this socket, 
+%% but we do it anyway to simplify the sequence.
+tpp_udp_server_handler_create() ->
+    Self = self(),
+    erlang:spawn(fun() -> tpp_udp_server_handler(Self) end).
+
+tpp_udp_server_handler(Parent) ->
+    tpp_udp_server_handler_init(Parent),
+    {Sock, Send, Recv} = tpp_udp_handler_await_start(Parent),
+    tpp_udp_handler_announce_ready(Parent, init),
+    tpp_udp_handler_await_continue(Parent, recv),
+    Result = tpp_udp_server_handler_msg_exchange(Sock, Send, Recv),
+    tpp_udp_handler_announce_ready(Parent, recv, Result),
+    Reason = tpp_udp_handler_await_terminate(Parent),
+    ?SEV_IPRINT("terminating"),
+    exit(Reason).
+
+tpp_udp_server_handler_init(Parent) ->
+    put(sname, "shandler"),
+    ?SEV_IPRINT("init"),
+    _MRef = erlang:monitor(process, Parent),
+    ok.
+
+tpp_udp_server_handler_msg_exchange(Sock, Send, Recv) ->
+    tpp_udp_server_handler_msg_exchange_loop(Sock, Send, Recv,
+                                             0, 0, 0, undefined).
+
+tpp_udp_server_handler_msg_exchange_loop(Sock, Send, Recv, 
+                                         N, Sent, Received, Start) ->
+    %% ?SEV_IPRINT("[~w] try receive", [N]),
+    %% if 
+    %%     (N =:= (?TPP_SMALL_NUM-2)) -> 
+    %%         ?SEV_IPRINT("[~w] try receive", [N]),
+    %%         socket:setopt(Sock, otp, debug, true); 
+    %%     true -> ok
+    %% end,
+    try tpp_udp_recv_req(Sock, Recv) of
+        {ok, Msg, RecvSz, From} ->
+            NewStart = if (Start =:= undefined) -> ?LIB:timestamp(); 
+                          true -> Start end,
+            %% ?SEV_IPRINT("[~w] received - now try send", [N]),
+            try tpp_udp_send_rep(Sock, Send, Msg, From) of
+                {ok, SendSz} ->
+                    tpp_udp_server_handler_msg_exchange_loop(Sock, Send, Recv,
+                                                             N+1,
+                                                             Sent+SendSz,
+                                                             Received+RecvSz,
+                                                             NewStart);
+                {error, SReason} ->
+                    ?SEV_EPRINT("send (~w): ~p", [N, SReason]),
+                    exit({send, SReason, N})
+	    catch
+		SC:SE:SS ->
+		    exit({send, {SC, SE, SS}, N})
+            end;
+        {error, closed} ->
+            ?SEV_IPRINT("closed - we are done: ~w, ~w, ~w",
+                        [N, Sent, Received]),
+            Stop = ?LIB:timestamp(),
+            {N, Sent, Received, Start, Stop};
+        {error, RReason} ->
+            ?SEV_EPRINT("recv (~w): ~p", [N, RReason]),
+            exit({recv, RReason, N})
+    catch
+	RC:RE:RS ->
+	    exit({recv, {RC, RE, RS}, N})	
+    end.
+  
+
+%% The (remote) client side handler process
+
+tpp_udp_client_handler_create(Node) ->
+    Self = self(),
+    Fun  = fun() -> put(sname, "chandler"), tpp_udp_client_handler(Self) end,
+    erlang:spawn(Node, Fun).
+
+tpp_udp_client_handler(Parent) ->
+    tpp_udp_client_handler_init(Parent),
+    ?SEV_IPRINT("await start command"),
+    {ServerSA, Proto, BufInit, Send, Recv} = tpp_udp_handler_await_start(Parent),
+    ?SEV_IPRINT("start command with"
+                "~n   ServerSA: ~p", [ServerSA]),
+    Domain   = maps:get(family, ServerSA),
+    Sock     = tpp_udp_sock_open(Domain, Proto, BufInit),
+    Path     = tpp_udp_sock_bind(Sock, Domain),
+    ?SEV_IPRINT("announce ready", []),
+    tpp_udp_handler_announce_ready(Parent, init),
+    {InitMsg, Num} = tpp_udp_handler_await_continue(Parent, send),
+    ?SEV_IPRINT("received continue with"
+                "~n   Num: ~p", [Num]),
+    Result = tpp_udp_client_handler_msg_exchange(Sock, ServerSA, 
+                                                 Send, Recv, InitMsg, Num),
+    ?SEV_IPRINT("ready"),
+    tpp_udp_handler_announce_ready(Parent, send, Result),
+    ?SEV_IPRINT("await terminate"),
+    Reason = tpp_udp_handler_await_terminate(Parent),
+    ?SEV_IPRINT("terminate with ~p", [Reason]),
+    tpp_udp_sock_close(Sock, Path),
+    ?SEV_IPRINT("terminating"),
+    exit(Reason).
+
+tpp_udp_client_handler_init(Parent) ->
+    put(sname, "chandler"),
+    ?SEV_IPRINT("init"),
+    _MRef = erlang:monitor(process, Parent),
+    ok.
+
+tpp_udp_client_handler_msg_exchange(Sock, ServerSA,
+                                    Send, Recv, InitMsg, Num) ->
+    Start = ?LIB:timestamp(),
+    tpp_udp_client_handler_msg_exchange_loop(Sock, ServerSA,
+                                             Send, Recv, InitMsg,
+                                             Num, 0, 0, 0, Start).
+
+tpp_udp_client_handler_msg_exchange_loop(_Sock, _Dest, _Send, _Recv, _Msg,
+                                         Num, Num, Sent, Received,
+                                         Start) ->
+    Stop = ?LIB:timestamp(),
+    {Sent, Received, Start, Stop};
+tpp_udp_client_handler_msg_exchange_loop(Sock,
+					 #{family := local} = Dest,
+					 Send, Recv, Data,
+                                         Num, N, Sent, Received, Start) ->
+    case tpp_udp_send_req(Sock, Send, Data, Dest) of
+        {ok, SendSz} ->
+            case tpp_udp_recv_rep(Sock, Recv) of
+                {ok, NewData, RecvSz, Dest} ->
+                    tpp_udp_client_handler_msg_exchange_loop(Sock, Dest,
+                                                             Send, Recv,
+                                                             NewData, Num, N+1,
+                                                             Sent+SendSz, 
+                                                             Received+RecvSz, 
+                                                             Start);
+                {error, RReason} ->
+                    ?SEV_EPRINT("recv (~w of ~w): ~p", [N, Num, RReason]),
+                    exit({recv, RReason, N})
+            end;
+        {error, SReason} ->
+            ?SEV_EPRINT("send (~w of ~w): ~p", [N, Num, SReason]),
+            exit({send, SReason, N})
+    end;
+tpp_udp_client_handler_msg_exchange_loop(Sock,
+					 #{addr := Addr, port := Port} = Dest0,
+					 Send, Recv, Data,
+                                         Num, N, Sent, Received, Start) ->
+    case tpp_udp_send_req(Sock, Send, Data, Dest0) of
+        {ok, SendSz} ->
+            case tpp_udp_recv_rep(Sock, Recv) of
+                {ok, NewData, RecvSz, #{addr := Addr, port := Port} = Dest1} ->
+                    tpp_udp_client_handler_msg_exchange_loop(Sock, Dest1,
+                                                             Send, Recv,
+                                                             NewData, Num, N+1,
+                                                             Sent+SendSz, 
+                                                             Received+RecvSz, 
+                                                             Start);
+                {error, RReason} ->
+                    ?SEV_EPRINT("recv (~w of ~w): ~p", [N, Num, RReason]),
+                    exit({recv, RReason, N})
+            end;
+        {error, SReason} ->
+            ?SEV_EPRINT("send (~w of ~w): ~p", [N, Num, SReason]),
+            exit({send, SReason, N})
+    end.
+
+
+tpp_udp_recv_req(Sock, Recv) ->
+    tpp_udp_recv(Sock, Recv, ?TPP_REQUEST).
+
+tpp_udp_recv_rep(Sock, Recv) ->
+    tpp_udp_recv(Sock, Recv, ?TPP_REPLY).
+
+tpp_udp_recv(Sock, Recv, Tag) ->
+    %% ok = socket:setopt(Sock, otp, debug, true),
+    try Recv(Sock, 0) of
+        {ok, {Source, <<Tag:32/integer, Sz:32/integer, Data/binary>> = Msg}} 
+          when (Sz =:= size(Data)) ->
+	    %% ok = socket:setopt(Sock, otp, debug, false),
+            %% We got it all
+            %% ?SEV_IPRINT("tpp_udp_recv -> got all: "
+            %%             "~n   Source:     ~p"
+            %%             "~n   Tag:        ~p"
+            %%             "~n   Sz:         ~p"
+            %%             "~n   size(Data): ~p",
+            %%             [Source, Tag, Sz, size(Data)]),
+            {ok, Data, size(Msg), Source};
+        {ok, {_Source, <<Tag:32/integer, Sz:32/integer, Data/binary>>}} ->
+	    %% ok = socket:setopt(Sock, otp, debug, false),
+            {error, {invalid_msg, Sz, size(Data)}};
+        {ok, {_, <<Tag:32/integer, _/binary>>}} ->
+	    %% ok = socket:setopt(Sock, otp, debug, false),
+            {error, {invalid_msg_tag, Tag}};
+        {error, _} = ERROR ->
+	    %% ok = socket:setopt(Sock, otp, debug, false),
+            ERROR
+    catch
+	C:E:S ->
+	    {error, {catched, C, E, S}}
+    end.
+
+tpp_udp_send_req(Sock, Send, Data, Dest) ->
+    tpp_udp_send(Sock, Send, ?TPP_REQUEST, Data, Dest).
+
+tpp_udp_send_rep(Sock, Send, Data, Dest) ->
+    tpp_udp_send(Sock, Send, ?TPP_REPLY, Data, Dest).
+
+tpp_udp_send(Sock, Send, Tag, Data, Dest) ->
+    DataSz = size(Data),
+    Msg    = <<Tag:32/integer, DataSz:32/integer, Data/binary>>,
+    tpp_udp_send_msg(Sock, Send, Msg, Dest, 0).
+
+tpp_udp_send_msg(Sock, Send, Msg, Dest, AccSz) when is_binary(Msg) ->
+    case Send(Sock, Msg, Dest) of
+        ok ->
+            {ok, AccSz+size(Msg)};
+        {ok, Rest} -> % This is an IOVec
+            RestBin = list_to_binary(Rest),
+            tpp_udp_send_msg(Sock, Send, RestBin, Dest,
+                             AccSz+(size(Msg)-size(RestBin)));
+        {error, _} = ERROR ->
+            ERROR
+    end.
+    
+
+tpp_udp_handler_await_start(Parent) ->
+    ?SEV_IPRINT("await start"),
+    ?SEV_AWAIT_START(Parent).
+
+tpp_udp_handler_announce_ready(Parent, Slogan) ->
+    ?SEV_IPRINT("announce ready (~p)", [Slogan]),
+    ?SEV_ANNOUNCE_READY(Parent, Slogan).
+tpp_udp_handler_announce_ready(Parent, Slogan, Extra) ->
+    ?SEV_IPRINT("announce ready (~p)", [Slogan]),
+    ?SEV_ANNOUNCE_READY(Parent, Slogan, Extra).
+
+tpp_udp_handler_await_continue(Parent, Slogan) ->
+    ?SEV_IPRINT("await continue (~p)", [Slogan]),
+    case ?SEV_AWAIT_CONTINUE(Parent, parent, Slogan) of
+        ok ->
+            ?SEV_IPRINT("continue (~p): ok", [Slogan]),
+            ok;
+        {ok, Data} ->
+            ?SEV_IPRINT("continue (~p): ok with data", [Slogan]),
+            Data;
+        {error, Reason} ->
+            ?SEV_EPRINT("continue (~p): error"
+                        "~n   ~p", [Slogan, Reason]),
+            exit({continue, Slogan, Reason})
+    end.
+
+tpp_udp_handler_await_terminate(Parent) ->
+    ?SEV_IPRINT("await terminate"),
+    case ?SEV_AWAIT_TERMINATE(Parent, parent) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            Reason
+    end.
+
+
+tpp_udp_sock_open(Domain, Proto, BufInit) ->
+    case socket:open(Domain, dgram, Proto) of
+        {ok, Sock} ->
+            ok = BufInit(Sock),
+            Sock;
+        {error, Reason} ->
+            exit({open_failed, Reason})
+    end.
+
+tpp_udp_sock_bind(Sock, Domain) ->
+    LSA = which_local_socket_addr(Domain),
+    case socket:bind(Sock, LSA) of
+        {ok, _} ->
+            ok;
+        {error, Reason} ->
+            exit({bind, Reason})
+    end.
+
+tpp_udp_sock_close(Sock, Path) ->
+    case socket:close(Sock) of
+        ok ->
+            unlink_path(Path),
+            ok;
+        {error, Reason} ->
+            ?SEV_EPRINT("Failed closing socket: "
+                        "~n   ~p", [Reason]),
+            unlink_path(Path),
+            {error, {close, Reason}}
+    end.
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgenf_cgenf_small_tcp4(suite) ->
+    [];
+ttest_sgenf_cgenf_small_tcp4(doc) ->
+    [];
+ttest_sgenf_cgenf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgenf_small_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_cgenf_small_tcp6(suite) ->
+    [];
+ttest_sgenf_cgenf_small_tcp6(doc) ->
+    [];
+ttest_sgenf_cgenf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgenf_small_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgenf_cgenf_medium_tcp4(suite) ->
+    [];
+ttest_sgenf_cgenf_medium_tcp4(doc) ->
+    [];
+ttest_sgenf_cgenf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgenf_medium_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_cgenf_medium_tcp6(suite) ->
+    [];
+ttest_sgenf_cgenf_medium_tcp6(doc) ->
+    [];
+ttest_sgenf_cgenf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgenf_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgenf_cgenf_large_tcp4(suite) ->
+    [];
+ttest_sgenf_cgenf_large_tcp4(doc) ->
+    [];
+ttest_sgenf_cgenf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgenf_large_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_cgenf_large_tcp6(suite) ->
+    [];
+ttest_sgenf_cgenf_large_tcp6(doc) ->
+    [];
+ttest_sgenf_cgenf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgenf_large_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgenf_cgeno_small_tcp4(suite) ->
+    [];
+ttest_sgenf_cgeno_small_tcp4(doc) ->
+    [];
+ttest_sgenf_cgeno_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgeno_small_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_cgeno_small_tcp6(suite) ->
+    [];
+ttest_sgenf_cgeno_small_tcp6(doc) ->
+    [];
+ttest_sgenf_cgeno_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgenf_cgeno_medium_tcp4(suite) ->
+    [];
+ttest_sgenf_cgeno_medium_tcp4(doc) ->
+    [];
+ttest_sgenf_cgeno_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgeno_medium_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_cgeno_medium_tcp6(suite) ->
+    [];
+ttest_sgenf_cgeno_medium_tcp6(doc) ->
+    [];
+ttest_sgenf_cgeno_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgeno_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgenf_cgeno_large_tcp4(suite) ->
+    [];
+ttest_sgenf_cgeno_large_tcp4(doc) ->
+    [];
+ttest_sgenf_cgeno_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgeno_large_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_cgeno_large_tcp6(suite) ->
+    [];
+ttest_sgenf_cgeno_large_tcp6(doc) ->
+    [];
+ttest_sgenf_cgeno_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgeno_large_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgenf_cgent_small_tcp4(suite) ->
+    [];
+ttest_sgenf_cgent_small_tcp4(doc) ->
+    [];
+ttest_sgenf_cgent_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgent_small_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_cgent_small_tcp6(suite) ->
+    [];
+ttest_sgenf_cgent_small_tcp6(doc) ->
+    [];
+ttest_sgenf_cgent_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgenf_cgent_medium_tcp4(suite) ->
+    [];
+ttest_sgenf_cgent_medium_tcp4(doc) ->
+    [];
+ttest_sgenf_cgent_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgent_medium_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_cgent_medium_tcp6(suite) ->
+    [];
+ttest_sgenf_cgent_medium_tcp6(doc) ->
+    [];
+ttest_sgenf_cgent_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgent_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgenf_cgent_large_tcp4(suite) ->
+    [];
+ttest_sgenf_cgent_large_tcp4(doc) ->
+    [];
+ttest_sgenf_cgent_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgent_large_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_cgent_large_tcp6(suite) ->
+    [];
+ttest_sgenf_cgent_large_tcp6(doc) ->
+    [];
+ttest_sgenf_cgent_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_cgent_large_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgenf_csockf_small_tcp4(suite) ->
+    [];
+ttest_sgenf_csockf_small_tcp4(doc) ->
+    [];
+ttest_sgenf_csockf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockf_small_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_csockf_small_tcp6(suite) ->
+    [];
+ttest_sgenf_csockf_small_tcp6(doc) ->
+    [];
+ttest_sgenf_csockf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockf_small_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgenf_csockf_medium_tcp4(suite) ->
+    [];
+ttest_sgenf_csockf_medium_tcp4(doc) ->
+    [];
+ttest_sgenf_csockf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockf_medium_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_csockf_medium_tcp6(suite) ->
+    [];
+ttest_sgenf_csockf_medium_tcp6(doc) ->
+    [];
+ttest_sgenf_csockf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockf_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgenf_csockf_large_tcp4(suite) ->
+    [];
+ttest_sgenf_csockf_large_tcp4(doc) ->
+    [];
+ttest_sgenf_csockf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockf_large_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_csockf_large_tcp6(suite) ->
+    [];
+ttest_sgenf_csockf_large_tcp6(doc) ->
+    [];
+ttest_sgenf_csockf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockf_large_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgenf_csocko_small_tcp4(suite) ->
+    [];
+ttest_sgenf_csocko_small_tcp4(doc) ->
+    [];
+ttest_sgenf_csocko_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csocko_small_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_csocko_small_tcp6(suite) ->
+    [];
+ttest_sgenf_csocko_small_tcp6(doc) ->
+    [];
+ttest_sgenf_csocko_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgenf_csocko_medium_tcp4(suite) ->
+    [];
+ttest_sgenf_csocko_medium_tcp4(doc) ->
+    [];
+ttest_sgenf_csocko_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csocko_medium_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_csocko_medium_tcp6(suite) ->
+    [];
+ttest_sgenf_csocko_medium_tcp6(doc) ->
+    [];
+ttest_sgenf_csocko_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csocko_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgenf_csocko_large_tcp4(suite) ->
+    [];
+ttest_sgenf_csocko_large_tcp4(doc) ->
+    [];
+ttest_sgenf_csocko_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csocko_large_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_csocko_large_tcp6(suite) ->
+    [];
+ttest_sgenf_csocko_large_tcp6(doc) ->
+    [];
+ttest_sgenf_csocko_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csocko_large_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgenf_csockt_small_tcp4(suite) ->
+    [];
+ttest_sgenf_csockt_small_tcp4(doc) ->
+    [];
+ttest_sgenf_csockt_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockt_small_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_csockt_small_tcp6(suite) ->
+    [];
+ttest_sgenf_csockt_small_tcp6(doc) ->
+    [];
+ttest_sgenf_csockt_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgenf_csockt_medium_tcp4(suite) ->
+    [];
+ttest_sgenf_csockt_medium_tcp4(doc) ->
+    [];
+ttest_sgenf_csockt_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockt_medium_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_csockt_medium_tcp6(suite) ->
+    [];
+ttest_sgenf_csockt_medium_tcp6(doc) ->
+    [];
+ttest_sgenf_csockt_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockt_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgenf_csockt_large_tcp4(suite) ->
+    [];
+ttest_sgenf_csockt_large_tcp4(doc) ->
+    [];
+ttest_sgenf_csockt_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockt_large_tcp4,
+              Runtime,
+              inet,
+              gen, false,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgenf_csockt_large_tcp6(suite) ->
+    [];
+ttest_sgenf_csockt_large_tcp6(doc) ->
+    [];
+ttest_sgenf_csockt_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgenf_csockt_large_tcp6,
+              Runtime,
+              inet6,
+              gen, false,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgeno_cgenf_small_tcp4(suite) ->
+    [];
+ttest_sgeno_cgenf_small_tcp4(doc) ->
+    [];
+ttest_sgeno_cgenf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgenf_small_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_cgenf_small_tcp6(suite) ->
+    [];
+ttest_sgeno_cgenf_small_tcp6(doc) ->
+    [];
+ttest_sgeno_cgenf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgenf_small_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgeno_cgenf_medium_tcp4(suite) ->
+    [];
+ttest_sgeno_cgenf_medium_tcp4(doc) ->
+    [];
+ttest_sgeno_cgenf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgenf_medium_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_cgenf_medium_tcp6(suite) ->
+    [];
+ttest_sgeno_cgenf_medium_tcp6(doc) ->
+    [];
+ttest_sgeno_cgenf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgenf_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgeno_cgenf_large_tcp4(suite) ->
+    [];
+ttest_sgeno_cgenf_large_tcp4(doc) ->
+    [];
+ttest_sgeno_cgenf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgenf_large_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_cgenf_large_tcp6(suite) ->
+    [];
+ttest_sgeno_cgenf_large_tcp6(doc) ->
+    [];
+ttest_sgeno_cgenf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgenf_large_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgeno_cgeno_small_tcp4(suite) ->
+    [];
+ttest_sgeno_cgeno_small_tcp4(doc) ->
+    [];
+ttest_sgeno_cgeno_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgeno_small_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_cgeno_small_tcp6(suite) ->
+    [];
+ttest_sgeno_cgeno_small_tcp6(doc) ->
+    [];
+ttest_sgeno_cgeno_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgeno_cgeno_medium_tcp4(suite) ->
+    [];
+ttest_sgeno_cgeno_medium_tcp4(doc) ->
+    [];
+ttest_sgeno_cgeno_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgeno_medium_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_cgeno_medium_tcp6(suite) ->
+    [];
+ttest_sgeno_cgeno_medium_tcp6(doc) ->
+    [];
+ttest_sgeno_cgeno_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgeno_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgeno_cgeno_large_tcp4(suite) ->
+    [];
+ttest_sgeno_cgeno_large_tcp4(doc) ->
+    [];
+ttest_sgeno_cgeno_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgeno_large_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_cgeno_large_tcp6(suite) ->
+    [];
+ttest_sgeno_cgeno_large_tcp6(doc) ->
+    [];
+ttest_sgeno_cgeno_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgeno_large_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgeno_cgent_small_tcp4(suite) ->
+    [];
+ttest_sgeno_cgent_small_tcp4(doc) ->
+    [];
+ttest_sgeno_cgent_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgent_small_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_cgent_small_tcp6(suite) ->
+    [];
+ttest_sgeno_cgent_small_tcp6(doc) ->
+    [];
+ttest_sgeno_cgent_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgeno_cgent_medium_tcp4(suite) ->
+    [];
+ttest_sgeno_cgent_medium_tcp4(doc) ->
+    [];
+ttest_sgeno_cgent_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgent_medium_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_cgent_medium_tcp6(suite) ->
+    [];
+ttest_sgeno_cgent_medium_tcp6(doc) ->
+    [];
+ttest_sgeno_cgent_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgent_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgeno_cgent_large_tcp4(suite) ->
+    [];
+ttest_sgeno_cgent_large_tcp4(doc) ->
+    [];
+ttest_sgeno_cgent_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgent_large_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_cgent_large_tcp6(suite) ->
+    [];
+ttest_sgeno_cgent_large_tcp6(doc) ->
+    [];
+ttest_sgeno_cgent_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_cgent_large_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgeno_csockf_small_tcp4(suite) ->
+    [];
+ttest_sgeno_csockf_small_tcp4(doc) ->
+    [];
+ttest_sgeno_csockf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockf_small_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_csockf_small_tcp6(suite) ->
+    [];
+ttest_sgeno_csockf_small_tcp6(doc) ->
+    [];
+ttest_sgeno_csockf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockf_small_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgeno_csockf_medium_tcp4(suite) ->
+    [];
+ttest_sgeno_csockf_medium_tcp4(doc) ->
+    [];
+ttest_sgeno_csockf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockf_medium_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_csockf_medium_tcp6(suite) ->
+    [];
+ttest_sgeno_csockf_medium_tcp6(doc) ->
+    [];
+ttest_sgeno_csockf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockf_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgeno_csockf_large_tcp4(suite) ->
+    [];
+ttest_sgeno_csockf_large_tcp4(doc) ->
+    [];
+ttest_sgeno_csockf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockf_large_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_csockf_large_tcp6(suite) ->
+    [];
+ttest_sgeno_csockf_large_tcp6(doc) ->
+    [];
+ttest_sgeno_csockf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockf_large_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgeno_csocko_small_tcp4(suite) ->
+    [];
+ttest_sgeno_csocko_small_tcp4(doc) ->
+    [];
+ttest_sgeno_csocko_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csocko_small_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_csocko_small_tcp6(suite) ->
+    [];
+ttest_sgeno_csocko_small_tcp6(doc) ->
+    [];
+ttest_sgeno_csocko_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgeno_csocko_medium_tcp4(suite) ->
+    [];
+ttest_sgeno_csocko_medium_tcp4(doc) ->
+    [];
+ttest_sgeno_csocko_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csocko_medium_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_csocko_medium_tcp6(suite) ->
+    [];
+ttest_sgeno_csocko_medium_tcp6(doc) ->
+    [];
+ttest_sgeno_csocko_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csocko_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgeno_csocko_large_tcp4(suite) ->
+    [];
+ttest_sgeno_csocko_large_tcp4(doc) ->
+    [];
+ttest_sgeno_csocko_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csocko_large_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_csocko_large_tcp6(suite) ->
+    [];
+ttest_sgeno_csocko_large_tcp6(doc) ->
+    [];
+ttest_sgeno_csocko_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csocko_large_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgeno_csockt_small_tcp4(suite) ->
+    [];
+ttest_sgeno_csockt_small_tcp4(doc) ->
+    [];
+ttest_sgeno_csockt_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockt_small_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_csockt_small_tcp6(suite) ->
+    [];
+ttest_sgeno_csockt_small_tcp6(doc) ->
+    [];
+ttest_sgeno_csockt_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgeno_csockt_medium_tcp4(suite) ->
+    [];
+ttest_sgeno_csockt_medium_tcp4(doc) ->
+    [];
+ttest_sgeno_csockt_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockt_medium_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_csockt_medium_tcp6(suite) ->
+    [];
+ttest_sgeno_csockt_medium_tcp6(doc) ->
+    [];
+ttest_sgeno_csockt_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockt_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgeno_csockt_large_tcp4(suite) ->
+    [];
+ttest_sgeno_csockt_large_tcp4(doc) ->
+    [];
+ttest_sgeno_csockt_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockt_large_tcp4,
+              Runtime,
+              inet,
+              gen, once,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgeno_csockt_large_tcp6(suite) ->
+    [];
+ttest_sgeno_csockt_large_tcp6(doc) ->
+    [];
+ttest_sgeno_csockt_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgeno_csockt_large_tcp6,
+              Runtime,
+              inet6,
+              gen, once,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgent_cgenf_small_tcp4(suite) ->
+    [];
+ttest_sgent_cgenf_small_tcp4(doc) ->
+    [];
+ttest_sgent_cgenf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgenf_small_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_cgenf_small_tcp6(suite) ->
+    [];
+ttest_sgent_cgenf_small_tcp6(doc) ->
+    [];
+ttest_sgent_cgenf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgenf_small_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgent_cgenf_medium_tcp4(suite) ->
+    [];
+ttest_sgent_cgenf_medium_tcp4(doc) ->
+    [];
+ttest_sgent_cgenf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgenf_medium_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_cgenf_medium_tcp6(suite) ->
+    [];
+ttest_sgent_cgenf_medium_tcp6(doc) ->
+    [];
+ttest_sgent_cgenf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgenf_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgent_cgenf_large_tcp4(suite) ->
+    [];
+ttest_sgent_cgenf_large_tcp4(doc) ->
+    [];
+ttest_sgent_cgenf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgenf_large_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_cgenf_large_tcp6(suite) ->
+    [];
+ttest_sgent_cgenf_large_tcp6(doc) ->
+    [];
+ttest_sgent_cgenf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgenf_large_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgent_cgeno_small_tcp4(suite) ->
+    [];
+ttest_sgent_cgeno_small_tcp4(doc) ->
+    [];
+ttest_sgent_cgeno_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgeno_small_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_cgeno_small_tcp6(suite) ->
+    [];
+ttest_sgent_cgeno_small_tcp6(doc) ->
+    [];
+ttest_sgent_cgeno_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgent_cgeno_medium_tcp4(suite) ->
+    [];
+ttest_sgent_cgeno_medium_tcp4(doc) ->
+    [];
+ttest_sgent_cgeno_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgeno_medium_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_cgeno_medium_tcp6(suite) ->
+    [];
+ttest_sgent_cgeno_medium_tcp6(doc) ->
+    [];
+ttest_sgent_cgeno_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgeno_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgent_cgeno_large_tcp4(suite) ->
+    [];
+ttest_sgent_cgeno_large_tcp4(doc) ->
+    [];
+ttest_sgent_cgeno_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgeno_large_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_cgeno_large_tcp6(suite) ->
+    [];
+ttest_sgent_cgeno_large_tcp6(doc) ->
+    [];
+ttest_sgent_cgeno_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgeno_large_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgent_cgent_small_tcp4(suite) ->
+    [];
+ttest_sgent_cgent_small_tcp4(doc) ->
+    [];
+ttest_sgent_cgent_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgent_small_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_cgent_small_tcp6(suite) ->
+    [];
+ttest_sgent_cgent_small_tcp6(doc) ->
+    [];
+ttest_sgent_cgent_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgent_cgent_medium_tcp4(suite) ->
+    [];
+ttest_sgent_cgent_medium_tcp4(doc) ->
+    ["Server(gen,true), Client(gen,true), Domain=inet, msg=medium"];
+ttest_sgent_cgent_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgent_medium_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_cgent_medium_tcp6(suite) ->
+    [];
+ttest_sgent_cgent_medium_tcp6(doc) ->
+    ["Server(gen,true), Client(gen,true), Domain=inet6, msg=medium"];
+ttest_sgent_cgent_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgent_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgent_cgent_large_tcp4(suite) ->
+    [];
+ttest_sgent_cgent_large_tcp4(doc) ->
+    ["Server(gen,true), Client(gen,true), Domain=inet, msg=large"];
+ttest_sgent_cgent_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgent_large_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_cgent_large_tcp6(suite) ->
+    [];
+ttest_sgent_cgent_large_tcp6(doc) ->
+    ["Server(gen,true), Client(gen,true), Domain=inet6, msg=large"];
+ttest_sgent_cgent_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_cgent_large_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgent_csockf_small_tcp4(suite) ->
+    [];
+ttest_sgent_csockf_small_tcp4(doc) ->
+    [];
+ttest_sgent_csockf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockf_small_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_csockf_small_tcp6(suite) ->
+    [];
+ttest_sgent_csockf_small_tcp6(doc) ->
+    [];
+ttest_sgent_csockf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockf_small_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgent_csockf_medium_tcp4(suite) ->
+    [];
+ttest_sgent_csockf_medium_tcp4(doc) ->
+    [];
+ttest_sgent_csockf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockf_medium_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_csockf_medium_tcp6(suite) ->
+    [];
+ttest_sgent_csockf_medium_tcp6(doc) ->
+    [];
+ttest_sgent_csockf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockf_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgent_csockf_large_tcp4(suite) ->
+    [];
+ttest_sgent_csockf_large_tcp4(doc) ->
+    [];
+ttest_sgent_csockf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockf_large_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_csockf_large_tcp6(suite) ->
+    [];
+ttest_sgent_csockf_large_tcp6(doc) ->
+    [];
+ttest_sgent_csockf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockf_large_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgent_csocko_small_tcp4(suite) ->
+    [];
+ttest_sgent_csocko_small_tcp4(doc) ->
+    [];
+ttest_sgent_csocko_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csocko_small_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_csocko_small_tcp6(suite) ->
+    [];
+ttest_sgent_csocko_small_tcp6(doc) ->
+    [];
+ttest_sgent_csocko_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgent_csocko_medium_tcp4(suite) ->
+    [];
+ttest_sgent_csocko_medium_tcp4(doc) ->
+    [];
+ttest_sgent_csocko_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csocko_medium_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_csocko_medium_tcp6(suite) ->
+    [];
+ttest_sgent_csocko_medium_tcp6(doc) ->
+    [];
+ttest_sgent_csocko_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csocko_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgent_csocko_large_tcp4(suite) ->
+    [];
+ttest_sgent_csocko_large_tcp4(doc) ->
+    [];
+ttest_sgent_csocko_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csocko_large_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_csocko_large_tcp6(suite) ->
+    [];
+ttest_sgent_csocko_large_tcp6(doc) ->
+    [];
+ttest_sgent_csocko_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csocko_large_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_sgent_csockt_small_tcp4(suite) ->
+    [];
+ttest_sgent_csockt_small_tcp4(doc) ->
+    [];
+ttest_sgent_csockt_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockt_small_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_csockt_small_tcp6(suite) ->
+    [];
+ttest_sgent_csockt_small_tcp6(doc) ->
+    [];
+ttest_sgent_csockt_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_sgent_csockt_medium_tcp4(suite) ->
+    [];
+ttest_sgent_csockt_medium_tcp4(doc) ->
+    [];
+ttest_sgent_csockt_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockt_medium_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_csockt_medium_tcp6(suite) ->
+    [];
+ttest_sgent_csockt_medium_tcp6(doc) ->
+    [];
+ttest_sgent_csockt_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockt_medium_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_sgent_csockt_large_tcp4(suite) ->
+    [];
+ttest_sgent_csockt_large_tcp4(doc) ->
+    [];
+ttest_sgent_csockt_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockt_large_tcp4,
+              Runtime,
+              inet,
+              gen, true,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = gen_tcp, Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_sgent_csockt_large_tcp6(suite) ->
+    [];
+ttest_sgent_csockt_large_tcp6(doc) ->
+    [];
+ttest_sgent_csockt_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_sgent_csockt_large_tcp6,
+              Runtime,
+              inet6,
+              gen, true,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockf_cgenf_small_tcp4(suite) ->
+    [];
+ttest_ssockf_cgenf_small_tcp4(doc) ->
+    [];
+ttest_ssockf_cgenf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgenf_small_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_cgenf_small_tcp6(suite) ->
+    [];
+ttest_ssockf_cgenf_small_tcp6(doc) ->
+    [];
+ttest_ssockf_cgenf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgenf_small_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockf_cgenf_medium_tcp4(suite) ->
+    [];
+ttest_ssockf_cgenf_medium_tcp4(doc) ->
+    [];
+ttest_ssockf_cgenf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgenf_medium_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_cgenf_medium_tcp6(suite) ->
+    [];
+ttest_ssockf_cgenf_medium_tcp6(doc) ->
+    [];
+ttest_ssockf_cgenf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgenf_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockf_cgenf_large_tcp4(suite) ->
+    [];
+ttest_ssockf_cgenf_large_tcp4(doc) ->
+    [];
+ttest_ssockf_cgenf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgenf_large_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_cgenf_large_tcp6(suite) ->
+    [];
+ttest_ssockf_cgenf_large_tcp6(doc) ->
+    [];
+ttest_ssockf_cgenf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgenf_large_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockf_cgeno_small_tcp4(suite) ->
+    [];
+ttest_ssockf_cgeno_small_tcp4(doc) ->
+    [];
+ttest_ssockf_cgeno_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgeno_small_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_cgeno_small_tcp6(suite) ->
+    [];
+ttest_ssockf_cgeno_small_tcp6(doc) ->
+    [];
+ttest_ssockf_cgeno_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockf_cgeno_medium_tcp4(suite) ->
+    [];
+ttest_ssockf_cgeno_medium_tcp4(doc) ->
+    [];
+ttest_ssockf_cgeno_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgeno_medium_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_cgeno_medium_tcp6(suite) ->
+    [];
+ttest_ssockf_cgeno_medium_tcp6(doc) ->
+    [];
+ttest_ssockf_cgeno_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgeno_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockf_cgeno_large_tcp4(suite) ->
+    [];
+ttest_ssockf_cgeno_large_tcp4(doc) ->
+    [];
+ttest_ssockf_cgeno_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgeno_large_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_cgeno_large_tcp6(suite) ->
+    [];
+ttest_ssockf_cgeno_large_tcp6(doc) ->
+    [];
+ttest_ssockf_cgeno_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgeno_large_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockf_cgent_small_tcp4(suite) ->
+    [];
+ttest_ssockf_cgent_small_tcp4(doc) ->
+    [];
+ttest_ssockf_cgent_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgent_small_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport =  socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_cgent_small_tcp6(suite) ->
+    [];
+ttest_ssockf_cgent_small_tcp6(doc) ->
+    [];
+ttest_ssockf_cgent_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockf_cgent_medium_tcp4(suite) ->
+    [];
+ttest_ssockf_cgent_medium_tcp4(doc) ->
+    [];
+ttest_ssockf_cgent_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgent_medium_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_cgent_medium_tcp6(suite) ->
+    [];
+ttest_ssockf_cgent_medium_tcp6(doc) ->
+    [];
+ttest_ssockf_cgent_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgent_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockf_cgent_large_tcp4(suite) ->
+    [];
+ttest_ssockf_cgent_large_tcp4(doc) ->
+    [];
+ttest_ssockf_cgent_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgent_large_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_cgent_large_tcp6(suite) ->
+    [];
+ttest_ssockf_cgent_large_tcp6(doc) ->
+    [];
+ttest_ssockf_cgent_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_cgent_large_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockf_csockf_small_tcp4(suite) ->
+    [];
+ttest_ssockf_csockf_small_tcp4(doc) ->
+    [];
+ttest_ssockf_csockf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockf_small_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_csockf_small_tcp6(suite) ->
+    [];
+ttest_ssockf_csockf_small_tcp6(doc) ->
+    [];
+ttest_ssockf_csockf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockf_small_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       local
+%% 
+
+ttest_ssockf_csockf_small_tcpL(suite) ->
+    [];
+ttest_ssockf_csockf_small_tcpL(doc) ->
+    [];
+ttest_ssockf_csockf_small_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockf_small_tcpL,
+              Runtime,
+              local,
+              sock, false,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockf_csockf_medium_tcp4(suite) ->
+    [];
+ttest_ssockf_csockf_medium_tcp4(doc) ->
+    [];
+ttest_ssockf_csockf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockf_medium_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_csockf_medium_tcp6(suite) ->
+    [];
+ttest_ssockf_csockf_medium_tcp6(doc) ->
+    [];
+ttest_ssockf_csockf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockf_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       local
+%% 
+
+ttest_ssockf_csockf_medium_tcpL(suite) ->
+    [];
+ttest_ssockf_csockf_medium_tcpL(doc) ->
+    [];
+ttest_ssockf_csockf_medium_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockf_medium_tcpL,
+              Runtime,
+              local,
+              sock, false,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockf_csockf_large_tcp4(suite) ->
+    [];
+ttest_ssockf_csockf_large_tcp4(doc) ->
+    [];
+ttest_ssockf_csockf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockf_large_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_csockf_large_tcp6(suite) ->
+    [];
+ttest_ssockf_csockf_large_tcp6(doc) ->
+    [];
+ttest_ssockf_csockf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockf_large_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       local
+%% 
+
+ttest_ssockf_csockf_large_tcpL(suite) ->
+    [];
+ttest_ssockf_csockf_large_tcpL(doc) ->
+    [];
+ttest_ssockf_csockf_large_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockf_large_tcpL,
+              Runtime,
+              local,
+              sock, false,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockf_csocko_small_tcp4(suite) ->
+    [];
+ttest_ssockf_csocko_small_tcp4(doc) ->
+    [];
+ttest_ssockf_csocko_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_small_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_csocko_small_tcp6(suite) ->
+    [];
+ttest_ssockf_csocko_small_tcp6(doc) ->
+    [];
+ttest_ssockf_csocko_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       local
+%% 
+
+ttest_ssockf_csocko_small_tcpL(suite) ->
+    [];
+ttest_ssockf_csocko_small_tcpL(doc) ->
+    [];
+ttest_ssockf_csocko_small_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_small_tcpL,
+              Runtime,
+              local,
+              sock, false,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockf_csocko_medium_tcp4(suite) ->
+    [];
+ttest_ssockf_csocko_medium_tcp4(doc) ->
+    [];
+ttest_ssockf_csocko_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_medium_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_csocko_medium_tcp6(suite) ->
+    [];
+ttest_ssockf_csocko_medium_tcp6(doc) ->
+    [];
+ttest_ssockf_csocko_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       local
+%% 
+
+ttest_ssockf_csocko_medium_tcpL(suite) ->
+    [];
+ttest_ssockf_csocko_medium_tcpL(doc) ->
+    [];
+ttest_ssockf_csocko_medium_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_medium_tcpL,
+              Runtime,
+              local,
+              sock, false,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockf_csocko_large_tcp4(suite) ->
+    [];
+ttest_ssockf_csocko_large_tcp4(doc) ->
+    [];
+ttest_ssockf_csocko_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_large_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_csocko_large_tcp6(suite) ->
+    [];
+ttest_ssockf_csocko_large_tcp6(doc) ->
+    [];
+ttest_ssockf_csocko_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_large_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       local
+%% 
+
+ttest_ssockf_csocko_large_tcpL(suite) ->
+    [];
+ttest_ssockf_csocko_large_tcpL(doc) ->
+    [];
+ttest_ssockf_csocko_large_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_large_tcpL,
+              Runtime,
+              local,
+              sock, false,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockf_csockt_small_tcp4(suite) ->
+    [];
+ttest_ssockf_csockt_small_tcp4(doc) ->
+    [];
+ttest_ssockf_csockt_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockt_small_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport =  socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_csockt_small_tcp6(suite) ->
+    [];
+ttest_ssockf_csockt_small_tcp6(doc) ->
+    [];
+ttest_ssockf_csockt_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport =  socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       local
+%% 
+
+ttest_ssockf_csockt_small_tcpL(suite) ->
+    [];
+ttest_ssockf_csockt_small_tcpL(doc) ->
+    [];
+ttest_ssockf_csockt_small_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csocko_small_tcpL,
+              Runtime,
+              local,
+              sock, false,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockf_csockt_medium_tcp4(suite) ->
+    [];
+ttest_ssockf_csockt_medium_tcp4(doc) ->
+    [];
+ttest_ssockf_csockt_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockt_medium_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_csockt_medium_tcp6(suite) ->
+    [];
+ttest_ssockf_csockt_medium_tcp6(doc) ->
+    [];
+ttest_ssockf_csockt_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockt_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       local
+%% 
+
+ttest_ssockf_csockt_medium_tcpL(suite) ->
+    [];
+ttest_ssockf_csockt_medium_tcpL(doc) ->
+    [];
+ttest_ssockf_csockt_medium_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockt_medium_tcpL,
+              Runtime,
+              local,
+              sock, false,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockf_csockt_large_tcp4(suite) ->
+    [];
+ttest_ssockf_csockt_large_tcp4(doc) ->
+    [];
+ttest_ssockf_csockt_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockt_large_tcp4,
+              Runtime,
+              inet,
+              sock, false,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockf_csockt_large_tcp6(suite) ->
+    [];
+ttest_ssockf_csockt_large_tcp6(doc) ->
+    [];
+ttest_ssockf_csockt_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockt_large_tcp6,
+              Runtime,
+              inet6,
+              sock, false,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       local
+%% 
+
+ttest_ssockf_csockt_large_tcpL(suite) ->
+    [];
+ttest_ssockf_csockt_large_tcpL(doc) ->
+    [];
+ttest_ssockf_csockt_large_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockf_csockt_large_tcpL,
+              Runtime,
+              local,
+              sock, false,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssocko_cgenf_small_tcp4(suite) ->
+    [];
+ttest_ssocko_cgenf_small_tcp4(doc) ->
+    [];
+ttest_ssocko_cgenf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgenf_small_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_cgenf_small_tcp6(suite) ->
+    [];
+ttest_ssocko_cgenf_small_tcp6(doc) ->
+    [];
+ttest_ssocko_cgenf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgenf_small_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssocko_cgenf_medium_tcp4(suite) ->
+    [];
+ttest_ssocko_cgenf_medium_tcp4(doc) ->
+    [];
+ttest_ssocko_cgenf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgenf_medium_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_cgenf_medium_tcp6(suite) ->
+    [];
+ttest_ssocko_cgenf_medium_tcp6(doc) ->
+    [];
+ttest_ssocko_cgenf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgenf_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssocko_cgenf_large_tcp4(suite) ->
+    [];
+ttest_ssocko_cgenf_large_tcp4(doc) ->
+    [];
+ttest_ssocko_cgenf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgenf_large_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_cgenf_large_tcp6(suite) ->
+    [];
+ttest_ssocko_cgenf_large_tcp6(doc) ->
+    [];
+ttest_ssocko_cgenf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgenf_large_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssocko_cgeno_small_tcp4(suite) ->
+    [];
+ttest_ssocko_cgeno_small_tcp4(doc) ->
+    [];
+ttest_ssocko_cgeno_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgeno_small_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_cgeno_small_tcp6(suite) ->
+    [];
+ttest_ssocko_cgeno_small_tcp6(doc) ->
+    [];
+ttest_ssocko_cgeno_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssocko_cgeno_medium_tcp4(suite) ->
+    [];
+ttest_ssocko_cgeno_medium_tcp4(doc) ->
+    [];
+ttest_ssocko_cgeno_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgeno_medium_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_cgeno_medium_tcp6(suite) ->
+    [];
+ttest_ssocko_cgeno_medium_tcp6(doc) ->
+    [];
+ttest_ssocko_cgeno_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgeno_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssocko_cgeno_large_tcp4(suite) ->
+    [];
+ttest_ssocko_cgeno_large_tcp4(doc) ->
+    [];
+ttest_ssocko_cgeno_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgeno_large_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_cgeno_large_tcp6(suite) ->
+    [];
+ttest_ssocko_cgeno_large_tcp6(doc) ->
+    [];
+ttest_ssocko_cgeno_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgeno_large_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssocko_cgent_small_tcp4(suite) ->
+    [];
+ttest_ssocko_cgent_small_tcp4(doc) ->
+    [];
+ttest_ssocko_cgent_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgent_small_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport =  socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_cgent_small_tcp6(suite) ->
+    [];
+ttest_ssocko_cgent_small_tcp6(doc) ->
+    [];
+ttest_ssocko_cgent_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgent_small_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssocko_cgent_medium_tcp4(suite) ->
+    [];
+ttest_ssocko_cgent_medium_tcp4(doc) ->
+    [];
+ttest_ssocko_cgent_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgent_medium_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_cgent_medium_tcp6(suite) ->
+    [];
+ttest_ssocko_cgent_medium_tcp6(doc) ->
+    [];
+ttest_ssocko_cgent_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgent_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssocko_cgent_large_tcp4(suite) ->
+    [];
+ttest_ssocko_cgent_large_tcp4(doc) ->
+    [];
+ttest_ssocko_cgent_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgent_large_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = false
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_cgent_large_tcp6(suite) ->
+    [];
+ttest_ssocko_cgent_large_tcp6(doc) ->
+    [];
+ttest_ssocko_cgent_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_cgent_large_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssocko_csockf_small_tcp4(suite) ->
+    [];
+ttest_ssocko_csockf_small_tcp4(doc) ->
+    [];
+ttest_ssocko_csockf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockf_small_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_csockf_small_tcp6(suite) ->
+    [];
+ttest_ssocko_csockf_small_tcp6(doc) ->
+    [];
+ttest_ssocko_csockf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockf_small_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       local
+%% 
+
+ttest_ssocko_csockf_small_tcpL(suite) ->
+    [];
+ttest_ssocko_csockf_small_tcpL(doc) ->
+    [];
+ttest_ssocko_csockf_small_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockf_small_tcpL,
+              Runtime,
+              local,
+              sock, once,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssocko_csockf_medium_tcp4(suite) ->
+    [];
+ttest_ssocko_csockf_medium_tcp4(doc) ->
+    [];
+ttest_ssocko_csockf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockf_medium_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_csockf_medium_tcp6(suite) ->
+    [];
+ttest_ssocko_csockf_medium_tcp6(doc) ->
+    [];
+ttest_ssocko_csockf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockf_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       local
+%% 
+
+ttest_ssocko_csockf_medium_tcpL(suite) ->
+    [];
+ttest_ssocko_csockf_medium_tcpL(doc) ->
+    [];
+ttest_ssocko_csockf_medium_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockf_medium_tcpL,
+              Runtime,
+              local,
+              sock, once,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssocko_csockf_large_tcp4(suite) ->
+    [];
+ttest_ssocko_csockf_large_tcp4(doc) ->
+    [];
+ttest_ssocko_csockf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockf_large_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_csockf_large_tcp6(suite) ->
+    [];
+ttest_ssocko_csockf_large_tcp6(doc) ->
+    [];
+ttest_ssocko_csockf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockf_large_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       local
+%% 
+
+ttest_ssocko_csockf_large_tcpL(suite) ->
+    [];
+ttest_ssocko_csockf_large_tcpL(doc) ->
+    [];
+ttest_ssocko_csockf_large_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockf_large_tcpL,
+              Runtime,
+              local,
+              sock, once,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssocko_csocko_small_tcp4(suite) ->
+    [];
+ttest_ssocko_csocko_small_tcp4(doc) ->
+    [];
+ttest_ssocko_csocko_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_small_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_csocko_small_tcp6(suite) ->
+    [];
+ttest_ssocko_csocko_small_tcp6(doc) ->
+    [];
+ttest_ssocko_csocko_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       local
+%% 
+
+ttest_ssocko_csocko_small_tcpL(suite) ->
+    [];
+ttest_ssocko_csocko_small_tcpL(doc) ->
+    [];
+ttest_ssocko_csocko_small_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_small_tcpL,
+              Runtime,
+              local,
+              sock, once,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssocko_csocko_medium_tcp4(suite) ->
+    [];
+ttest_ssocko_csocko_medium_tcp4(doc) ->
+    [];
+ttest_ssocko_csocko_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_medium_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_csocko_medium_tcp6(suite) ->
+    [];
+ttest_ssocko_csocko_medium_tcp6(doc) ->
+    [];
+ttest_ssocko_csocko_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       local
+%% 
+
+ttest_ssocko_csocko_medium_tcpL(suite) ->
+    [];
+ttest_ssocko_csocko_medium_tcpL(doc) ->
+    [];
+ttest_ssocko_csocko_medium_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_medium_tcpL,
+              Runtime,
+              local,
+              sock, once,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssocko_csocko_large_tcp4(suite) ->
+    [];
+ttest_ssocko_csocko_large_tcp4(doc) ->
+    [];
+ttest_ssocko_csocko_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_large_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_csocko_large_tcp6(suite) ->
+    [];
+ttest_ssocko_csocko_large_tcp6(doc) ->
+    [];
+ttest_ssocko_csocko_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_large_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       local
+%% 
+
+ttest_ssocko_csocko_large_tcpL(suite) ->
+    [];
+ttest_ssocko_csocko_large_tcpL(doc) ->
+    [];
+ttest_ssocko_csocko_large_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_large_tcpL,
+              Runtime,
+              local,
+              sock, once,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssocko_csockt_small_tcp4(suite) ->
+    [];
+ttest_ssocko_csockt_small_tcp4(doc) ->
+    [];
+ttest_ssocko_csockt_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockt_small_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport =  socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_csockt_small_tcp6(suite) ->
+    [];
+ttest_ssocko_csockt_small_tcp6(doc) ->
+    [];
+ttest_ssocko_csockt_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport =  socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       local
+%% 
+
+ttest_ssocko_csockt_small_tcpL(suite) ->
+    [];
+ttest_ssocko_csockt_small_tcpL(doc) ->
+    [];
+ttest_ssocko_csockt_small_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csocko_small_tcpL,
+              Runtime,
+              local,
+              sock, once,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssocko_csockt_medium_tcp4(suite) ->
+    [];
+ttest_ssocko_csockt_medium_tcp4(doc) ->
+    [];
+ttest_ssocko_csockt_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockt_medium_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_csockt_medium_tcp6(suite) ->
+    [];
+ttest_ssocko_csockt_medium_tcp6(doc) ->
+    [];
+ttest_ssocko_csockt_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockt_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       local
+%% 
+
+ttest_ssocko_csockt_medium_tcpL(suite) ->
+    [];
+ttest_ssocko_csockt_medium_tcpL(doc) ->
+    [];
+ttest_ssocko_csockt_medium_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockt_medium_tcpL,
+              Runtime,
+              local,
+              sock, once,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssocko_csockt_large_tcp4(suite) ->
+    [];
+ttest_ssocko_csockt_large_tcp4(doc) ->
+    [];
+ttest_ssocko_csockt_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockt_large_tcp4,
+              Runtime,
+              inet,
+              sock, once,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssocko_csockt_large_tcp6(suite) ->
+    [];
+ttest_ssocko_csockt_large_tcp6(doc) ->
+    [];
+ttest_ssocko_csockt_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockt_large_tcp6,
+              Runtime,
+              inet6,
+              sock, once,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = once
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       local
+%% 
+
+ttest_ssocko_csockt_large_tcpL(suite) ->
+    [];
+ttest_ssocko_csockt_large_tcpL(doc) ->
+    [];
+ttest_ssocko_csockt_large_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssocko_csockt_large_tcpL,
+              Runtime,
+              local,
+              sock, once,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockt_cgenf_small_tcp4(suite) ->
+    [];
+ttest_ssockt_cgenf_small_tcp4(doc) ->
+    [];
+ttest_ssockt_cgenf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgenf_small_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_cgenf_small_tcp6(suite) ->
+    [];
+ttest_ssockt_cgenf_small_tcp6(doc) ->
+    [];
+ttest_ssockt_cgenf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgenf_small_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              gen, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockt_cgenf_medium_tcp4(suite) ->
+    [];
+ttest_ssockt_cgenf_medium_tcp4(doc) ->
+    [];
+ttest_ssockt_cgenf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgenf_medium_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_cgenf_medium_tcp6(suite) ->
+    [];
+ttest_ssockt_cgenf_medium_tcp6(doc) ->
+    [];
+ttest_ssockt_cgenf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgenf_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              gen, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockt_cgenf_large_tcp4(suite) ->
+    [];
+ttest_ssockt_cgenf_large_tcp4(doc) ->
+    [];
+ttest_ssockt_cgenf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgenf_large_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_cgenf_large_tcp6(suite) ->
+    [];
+ttest_ssockt_cgenf_large_tcp6(doc) ->
+    [];
+ttest_ssockt_cgenf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgenf_large_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              gen, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockt_cgeno_small_tcp4(suite) ->
+    [];
+ttest_ssockt_cgeno_small_tcp4(doc) ->
+    [];
+ttest_ssockt_cgeno_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgeno_small_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_cgeno_small_tcp6(suite) ->
+    [];
+ttest_ssockt_cgeno_small_tcp6(doc) ->
+    [];
+ttest_ssockt_cgeno_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgeno_small_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              gen, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockt_cgeno_medium_tcp4(suite) ->
+    [];
+ttest_ssockt_cgeno_medium_tcp4(doc) ->
+    [];
+ttest_ssockt_cgeno_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgeno_medium_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_cgeno_medium_tcp6(suite) ->
+    [];
+ttest_ssockt_cgeno_medium_tcp6(doc) ->
+    [];
+ttest_ssockt_cgeno_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgeno_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              gen, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockt_cgeno_large_tcp4(suite) ->
+    [];
+ttest_ssockt_cgeno_large_tcp4(doc) ->
+    [];
+ttest_ssockt_cgeno_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgeno_large_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_cgeno_large_tcp6(suite) ->
+    [];
+ttest_ssockt_cgeno_large_tcp6(doc) ->
+    [];
+ttest_ssockt_cgeno_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgeno_large_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              gen, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockt_cgent_small_tcp4(suite) ->
+    [];
+ttest_ssockt_cgent_small_tcp4(doc) ->
+    [];
+ttest_ssockt_cgent_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgent_small_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport =  socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_cgent_small_tcp6(suite) ->
+    [];
+ttest_ssockt_cgent_small_tcp6(doc) ->
+    [];
+ttest_ssockt_cgent_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgent_small_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              gen, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockt_cgent_medium_tcp4(suite) ->
+    [];
+ttest_ssockt_cgent_medium_tcp4(doc) ->
+    [];
+ttest_ssockt_cgent_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgent_medium_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_cgent_medium_tcp6(suite) ->
+    [];
+ttest_ssockt_cgent_medium_tcp6(doc) ->
+    [];
+ttest_ssockt_cgent_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgent_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              gen, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockt_cgent_large_tcp4(suite) ->
+    [];
+ttest_ssockt_cgent_large_tcp4(doc) ->
+    [];
+ttest_ssockt_cgent_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgent_large_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = gen_tcp, Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_cgent_large_tcp6(suite) ->
+    [];
+ttest_ssockt_cgent_large_tcp6(doc) ->
+    [];
+ttest_ssockt_cgent_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_cgent_large_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              gen, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockt_csockf_small_tcp4(suite) ->
+    [];
+ttest_ssockt_csockf_small_tcp4(doc) ->
+    [];
+ttest_ssockt_csockf_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockf_small_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_csockf_small_tcp6(suite) ->
+    [];
+ttest_ssockt_csockf_small_tcp6(doc) ->
+    [];
+ttest_ssockt_csockf_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockf_small_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: small (=1)
+%% Domain:       local
+%% 
+
+ttest_ssockt_csockf_small_tcpL(suite) ->
+    [];
+ttest_ssockt_csockf_small_tcpL(doc) ->
+    [];
+ttest_ssockt_csockf_small_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockf_small_tcpL,
+              Runtime,
+              local,
+              sock, true,
+              sock, false,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockt_csockf_medium_tcp4(suite) ->
+    [];
+ttest_ssockt_csockf_medium_tcp4(doc) ->
+    [];
+ttest_ssockt_csockf_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockf_medium_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_csockf_medium_tcp6(suite) ->
+    [];
+ttest_ssockt_csockf_medium_tcp6(doc) ->
+    [];
+ttest_ssockt_csockf_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockf_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: medium (=2)
+%% Domain:       local
+%% 
+
+ttest_ssockt_csockf_medium_tcpL(suite) ->
+    [];
+ttest_ssockt_csockf_medium_tcpL(doc) ->
+    [];
+ttest_ssockt_csockf_medium_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockf_medium_tcpL,
+              Runtime,
+              local,
+              sock, true,
+              sock, false,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockt_csockf_large_tcp4(suite) ->
+    [];
+ttest_ssockt_csockf_large_tcp4(doc) ->
+    [];
+ttest_ssockt_csockf_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockf_large_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_csockf_large_tcp6(suite) ->
+    [];
+ttest_ssockt_csockf_large_tcp6(doc) ->
+    [];
+ttest_ssockt_csockf_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockf_large_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = false
+%% Message Size: large (=3)
+%% Domain:       local
+%% 
+
+ttest_ssockt_csockf_large_tcpL(suite) ->
+    [];
+ttest_ssockt_csockf_large_tcpL(doc) ->
+    [];
+ttest_ssockt_csockf_large_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockf_large_tcpL,
+              Runtime,
+              local,
+              sock, true,
+              sock, false,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockt_csocko_small_tcp4(suite) ->
+    [];
+ttest_ssockt_csocko_small_tcp4(doc) ->
+    [];
+ttest_ssockt_csocko_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_small_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_csocko_small_tcp6(suite) ->
+    [];
+ttest_ssockt_csocko_small_tcp6(doc) ->
+    [];
+ttest_ssockt_csocko_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: small (=1)
+%% Domain:       local
+%% 
+
+ttest_ssockt_csocko_small_tcpL(suite) ->
+    [];
+ttest_ssockt_csocko_small_tcpL(doc) ->
+    [];
+ttest_ssockt_csocko_small_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_small_tcpL,
+              Runtime,
+              local,
+              sock, true,
+              sock, once,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockt_csocko_medium_tcp4(suite) ->
+    [];
+ttest_ssockt_csocko_medium_tcp4(doc) ->
+    [];
+ttest_ssockt_csocko_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_medium_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_csocko_medium_tcp6(suite) ->
+    [];
+ttest_ssockt_csocko_medium_tcp6(doc) ->
+    [];
+ttest_ssockt_csocko_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: medium (=2)
+%% Domain:       local
+%% 
+
+ttest_ssockt_csocko_medium_tcpL(suite) ->
+    [];
+ttest_ssockt_csocko_medium_tcpL(doc) ->
+    [];
+ttest_ssockt_csocko_medium_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_medium_tcpL,
+              Runtime,
+              local,
+              sock, true,
+              sock, once,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockt_csocko_large_tcp4(suite) ->
+    [];
+ttest_ssockt_csocko_large_tcp4(doc) ->
+    [];
+ttest_ssockt_csocko_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_large_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_csocko_large_tcp6(suite) ->
+    [];
+ttest_ssockt_csocko_large_tcp6(doc) ->
+    [];
+ttest_ssockt_csocko_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_large_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = once
+%% Message Size: large (=3)
+%% Domain:       local
+%% 
+
+ttest_ssockt_csocko_large_tcpL(suite) ->
+    [];
+ttest_ssockt_csocko_large_tcpL(doc) ->
+    [];
+ttest_ssockt_csocko_large_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_large_tcpL,
+              Runtime,
+              local,
+              sock, true,
+              sock, once,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet
+%%
+
+ttest_ssockt_csockt_small_tcp4(suite) ->
+    [];
+ttest_ssockt_csockt_small_tcp4(doc) ->
+    [];
+ttest_ssockt_csockt_small_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockt_small_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport =  socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_csockt_small_tcp6(suite) ->
+    [];
+ttest_ssockt_csockt_small_tcp6(doc) ->
+    [];
+ttest_ssockt_csockt_small_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_small_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport =  socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: small (=1)
+%% Domain:       local
+%% 
+
+ttest_ssockt_csockt_small_tcpL(suite) ->
+    [];
+ttest_ssockt_csockt_small_tcpL(doc) ->
+    [];
+ttest_ssockt_csockt_small_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csocko_small_tcpL,
+              Runtime,
+              local,
+              sock, true,
+              sock, true,
+              1, 200).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet
+%%
+
+ttest_ssockt_csockt_medium_tcp4(suite) ->
+    [];
+ttest_ssockt_csockt_medium_tcp4(doc) ->
+    [];
+ttest_ssockt_csockt_medium_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockt_medium_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_csockt_medium_tcp6(suite) ->
+    [];
+ttest_ssockt_csockt_medium_tcp6(doc) ->
+    [];
+ttest_ssockt_csockt_medium_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockt_medium_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: medium (=2)
+%% Domain:       local
+%% 
+
+ttest_ssockt_csockt_medium_tcpL(suite) ->
+    [];
+ttest_ssockt_csockt_medium_tcpL(doc) ->
+    [];
+ttest_ssockt_csockt_medium_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockt_medium_tcpL,
+              Runtime,
+              local,
+              sock, true,
+              sock, true,
+              2, 20).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet
+%%
+
+ttest_ssockt_csockt_large_tcp4(suite) ->
+    [];
+ttest_ssockt_csockt_large_tcp4(doc) ->
+    [];
+ttest_ssockt_csockt_large_tcp4(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockt_large_tcp4,
+              Runtime,
+              inet,
+              sock, true,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       inet6
+%% 
+
+ttest_ssockt_csockt_large_tcp6(suite) ->
+    [];
+ttest_ssockt_csockt_large_tcp6(doc) ->
+    [];
+ttest_ssockt_csockt_large_tcp6(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockt_large_tcp6,
+              Runtime,
+              inet6,
+              sock, true,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% This test case uses the time test (ttest) utility to implement a 
+%% ping-pong like test case.
+%% Server:       Transport = socket(tcp), Active = true
+%% Client:       Transport = socket(tcp), Active = true
+%% Message Size: large (=3)
+%% Domain:       local
+%% 
+
+ttest_ssockt_csockt_large_tcpL(suite) ->
+    [];
+ttest_ssockt_csockt_large_tcpL(doc) ->
+    [];
+ttest_ssockt_csockt_large_tcpL(Config) when is_list(Config) ->
+    Runtime = which_ttest_runtime(Config),
+    ttest_tcp(ttest_ssockt_csockt_large_tcpL,
+              Runtime,
+              local,
+              sock, true,
+              sock, true,
+              3, 2).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+which_ttest_runtime(Config) when is_list(Config) ->
+    case lists:keysearch(esock_test_ttest_runtime, 1, Config) of
+        {value, {esock_test_ttest_runtime, Runtime}} ->
+            Runtime;
+        false ->
+            which_ttest_runtime_env()
+    end.
+
+which_ttest_runtime_env() ->
+    which_ttest_runtime_env(os:getenv("ESOCK_TEST_TTEST_RUNTIME")).
+
+which_ttest_runtime_env(TStr) when is_list(TStr) ->
+    which_ttest_runtime_env2(lists:reverse(TStr));
+which_ttest_runtime_env(false) ->
+    ?TTEST_RUNTIME.
+
+
+%% The format is: <int>[unit]
+%% where the optional unit can be:
+%% ms: milliseconds
+%% s:  seconds (default)
+%% m:  minutes
+which_ttest_runtime_env2([$s, $m | MS]) when (length(MS) > 0) ->
+    convert_time(MS, fun(X) -> X end);
+which_ttest_runtime_env2([$m | M]) when (length(M) > 0) ->
+    convert_time(M, fun(X) -> ?MINS(X) end);
+which_ttest_runtime_env2([$s | S]) when (length(S) > 0) ->
+    convert_time(S, fun(X) -> ?SECS(X) end);
+which_ttest_runtime_env2(S) ->
+    convert_time(S, fun(X) -> ?SECS(X) end).
+
+convert_time(TStrRev, Convert) ->
+    try list_to_integer(lists:reverse(TStrRev)) of
+        I -> Convert(I)
+    catch
+        _:_ ->
+            ?TTEST_RUNTIME
+    end.
+
+%% ttest_tcp(TC,
+%%           Domain,
+%%           ServerMod, ServerActive,
+%%           ClientMod, ClientActive,
+%%           MsgID, MaxOutstanding) ->
+%%     ttest_tcp(TC,
+%%               ?TTEST_RUNTIME,
+%%               Domain,
+%%               ServerMod, ServerActive,
+%%               ClientMod, ClientActive,
+%%               MsgID, MaxOutstanding).
+ttest_tcp(TC,
+          Runtime,
+          Domain,
+          ServerMod, ServerActive,
+          ClientMod, ClientActive,
+          MsgID, MaxOutstanding) ->
+    tc_try(TC,
+           fun() ->
+                   if
+                       (Domain =:= local) -> has_support_unix_domain_socket(); 
+                       (Domain =:= inet6) -> has_support_ipv6();
+                       true -> ok 
+                   end
+           end,
+           fun() ->
+                   %% This may be overkill, depending on the runtime,
+                   %% but better safe then sorry...
+                   ?TT(Runtime + ?SECS(60)),
+                   InitState = #{domain          => Domain,
+                                 msg_id          => MsgID,
+                                 max_outstanding => MaxOutstanding,
+                                 runtime         => Runtime,
+                                 server_mod      => ServerMod,
+                                 server_active   => ServerActive,
+                                 client_mod      => ClientMod,
+                                 client_active   => ClientActive},
+                   ok = ttest_tcp(InitState)
+           end).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+ttest_tcp(InitState) ->
+    ServerSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+
+         %% *** Init part ***
+         #{desc => "create node",
+           cmd  => fun(#{host := Host} = State) ->
+                           case start_node(Host, server) of
+                               {ok, Node} ->
+                                   {ok, State#{node => Node}};
+                               {error, Reason} ->
+                                   {skip, Reason}
+                           end
+                   end},
+         #{desc => "monitor server node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           true = erlang:monitor_node(Node, true),
+                           ok
+                   end},
+         #{desc => "start ttest (remote) server",
+           cmd  => fun(#{domain := local = Domain,
+                         mod    := Mod,
+                         active := Active,
+                         node   := Node} = State) ->
+                           case ttest_tcp_server_start(Node,
+                                                       Domain, Mod, Active) of
+                               {ok, {{Pid, _}, Path}} ->
+                                   {ok, State#{rserver => Pid,
+                                               path    => Path}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{domain := Domain,
+                         mod    := Mod,
+                         active := Active,
+                         node   := Node} = State) ->
+                           case ttest_tcp_server_start(Node,
+                                                       Domain, Mod, Active) of
+                               {ok, {{Pid, _}, {Addr, Port}}} ->
+                                   {ok, State#{rserver => Pid,
+                                               addr    => Addr,
+                                               port    => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{domain := local,
+                         tester := Tester,
+                         path   := Path}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, Path),
+                           ok;
+                      (#{tester := Tester,
+                         addr   := Addr,
+                         port   := Port}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init, {Addr, Port}),
+                           ok
+                   end},
+
+
+         %% *** Termination ***
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester  := Tester, 
+                         rserver := RServer} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester,
+                                                     [{rserver, RServer}]) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         %% The remote server is in a accept, with a timeout of 5 seconds,
+         %% so may have to wait a bit...
+         #{desc => "order (remote) ttest server terminate",
+           cmd  => fun(#{node    := _Node,
+                         rserver := RServer}) ->
+                           ttest_tcp_server_stop(RServer),
+                           ok
+                   end},
+         #{desc => "await ttest (remote) server termination",
+           cmd  => fun(#{rserver := RServer} = State) ->
+                           ?SEV_AWAIT_TERMINATION(RServer),
+                           State1 = maps:remove(rserver, State),
+                           {ok, State1}
+                   end},
+         #{desc => "stop (server) node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           stop_node(Node)
+                   end},
+         #{desc => "await (server) node termination",
+           cmd  => fun(#{node := Node} = State) ->
+                           receive
+                               {nodedown, Node} ->
+                                   {ok, maps:remove(node, State)}
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    ClientSeq =
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(#{domain := local} = State) ->
+                           {Tester, ServerPath} = 
+                               ?SEV_AWAIT_START(),
+                           {ok, State#{tester      => Tester,
+                                       server_path => ServerPath}};
+                      (State) ->
+                           {Tester, {ServerAddr, ServerPort}} = 
+                               ?SEV_AWAIT_START(),
+                           {ok, State#{tester      => Tester,
+                                       server_addr => ServerAddr,
+                                       server_port => ServerPort}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+
+         %% *** Init part ***
+         #{desc => "create node",
+           cmd  => fun(#{host := Host} = State) ->
+                           case start_node(Host, client) of
+                               {ok, Node} ->
+                                   {ok, State#{node => Node}};
+                               {error, Reason} ->
+                                   {skip, Reason}
+                           end
+                   end},
+         #{desc => "monitor client node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           true = erlang:monitor_node(Node, true),
+                           ok
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, init),
+                           ok
+                   end},
+
+
+         %% The actual test
+         #{desc => "await continue (ttest)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, ttest),
+                           ok
+                   end},
+         #{desc => "start ttest (remote) client",
+           cmd  => fun(#{domain          := local = Domain,
+                         node            := Node,
+                         mod             := Mod,
+                         active          := Active,
+                         msg_id          := MsgID,
+                         max_outstanding := MaxOutstanding,
+                         runtime         := RunTime,
+                         server_path     := Path} = State) ->
+                           Self   = self(),
+                           Notify =
+                               fun(Result) ->
+                                       ?SEV_ANNOUNCE_READY(Self, ttest, Result)
+                               end,                           
+                           case ttest_tcp_client_start(Node, Notify,
+                                                       Domain, Mod,
+                                                       Path,
+                                                       Active,
+                                                       MsgID, MaxOutstanding,
+                                                       RunTime) of
+                               {ok, {Pid, _MRef}} ->
+                                   {ok, State#{rclient => Pid}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end;
+                      (#{domain          := Domain,
+                         node            := Node,
+                         mod             := Mod,
+                         active          := Active,
+                         msg_id          := MsgID,
+                         max_outstanding := MaxOutstanding,
+                         runtime         := RunTime,
+                         server_addr     := Addr,
+                         server_port     := Port} = State) ->
+                           Self   = self(),
+                           Notify =
+                               fun(Result) ->
+                                       ?SEV_ANNOUNCE_READY(Self, ttest, Result)
+                               end,                           
+                           case ttest_tcp_client_start(Node, Notify,
+                                                       Domain, Mod,
+                                                       {Addr, Port},
+                                                       Active,
+                                                       MsgID, MaxOutstanding,
+                                                       RunTime) of
+                               {ok, {Pid, _MRef}} ->
+                                   {ok, State#{rclient => Pid}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "await ttest ready",
+           cmd  => fun(#{tester  := Tester,
+                         rclient := RClient} = State) ->
+                           case ?SEV_AWAIT_READY(RClient, rclient, ttest, 
+                                                 [{tester, Tester}]) of
+                             {ok, Result} ->
+                                 {ok, State#{result => Result}};
+                             {error, _} = ERROR ->
+                                 ERROR
+                         end
+                   end},
+         #{desc => "await ttest (remote) client termination",
+           cmd  => fun(#{rclient := RClient} = State) ->
+                           ?SEV_AWAIT_TERMINATION(RClient),
+                           State1 = maps:remove(rclient, State),
+                           {ok, State1}
+                   end},
+         #{desc => "announce ready (ttest)",
+           cmd  => fun(#{tester := Tester,
+                         result := Result} = State) ->
+                           ?SEV_ANNOUNCE_READY(Tester, ttest, Result),
+                           {ok, maps:remove(result, State)}
+                   end},
+
+
+         %% *** Termination ***
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   {ok, maps:remove(tester, State)};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "stop (client) node",
+           cmd  => fun(#{node := Node} = _State) ->
+                           stop_node(Node)
+                   end},
+         #{desc => "await (client) node termination",
+           cmd  => fun(#{node := Node} = State) ->
+                           receive
+                               {nodedown, Node} ->
+                                   {ok, maps:remove(node, State)}
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    TesterSeq =
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+         #{desc => "monitor client",
+           cmd  => fun(#{client := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{domain := local,
+                         server := Pid} = State) ->
+                           {ok, Path} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_path => Path}};
+                      (#{server := Pid} = State) ->
+                           {ok, {Addr, Port}} =
+                               ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_addr => Addr,
+                                       server_port => Port}}
+                   end},
+
+
+         %% Start the client
+         #{desc => "order client start",
+           cmd  => fun(#{domain      := local,
+                         client      := Pid,
+                         server_path := Path} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, Path),
+                           ok;
+                      (#{client      := Pid,
+                         server_addr := Addr,
+                         server_port := Port} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid, {Addr, Port}),
+                           ok
+                   end},
+         #{desc => "await client ready (init)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Client, client, init)
+                   end},
+ 
+         %% The actual test
+         #{desc => "order client continue (ttest)",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Client, ttest),
+                           ok
+                   end},
+         #{desc => "await client ready (ttest)",
+           cmd  => fun(#{server := Server,
+                         client := Client} = State) ->
+                           case ?SEV_AWAIT_READY(Client, client, ttest,
+                                                 [{server, Server}]) of
+                               {ok, Result} ->
+                                   {ok, State#{result => Result}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** Terminate server ***
+         #{desc => "order client terminate",
+           cmd  => fun(#{client := Client} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Client),
+                           ok
+                   end},
+         #{desc => "await client down",
+           cmd  => fun(#{client := Client} = State) ->
+                           ?SEV_AWAIT_TERMINATION(Client),
+                           State1 = maps:remove(client,    State),
+                           {ok, State1}
+                   end},
+         #{desc => "order server terminate",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Server),
+                           ok
+                   end},
+         #{desc => "await server down",
+           cmd  => fun(#{server := Server} = _State) ->
+                           ?SEV_AWAIT_TERMINATION(Server),
+                           ok
+                   end},
+
+         
+         %% Present the results
+         #{desc => "present the results",
+           cmd  => fun(#{result        := Result,
+                         domain        := Domain,
+                         server_mod    := ServerTrans,
+                         server_active := ServerActive,
+                         client_mod    := ClientTrans,
+                         client_active := ClientActive,
+                         msg_id        := MsgID} = State) ->
+                           case Result of
+                               #{status  := ok,
+                                 runtime := RunTime,
+                                 cnt     := Cnt,
+                                 bcnt    := BCnt} ->
+                                   ttest_report(Domain,
+                                                ServerTrans, ServerActive,
+                                                ClientTrans, ClientActive,
+                                                MsgID,
+                                                RunTime, BCnt, Cnt),
+                                   ?SEV_IPRINT(
+                                      "TTest results: "
+                                      "~n   Run Time:                    ~s"
+                                      "~n   Byte Count:                  ~s"
+                                      "~n   Number of message exchanges: ~s"
+                                      "~n~n",
+                                      [
+                                       ?TTEST_LIB:format_time(RunTime),
+                                       if ((BCnt =:= 0) orelse (RunTime =:= 0)) ->
+                                               ?TTEST_LIB:format("~w, ~w",
+                                                                 [BCnt, RunTime]);
+                                          true ->
+                                               ?TTEST_LIB:format("~p => ~p byte / ms",
+                                                                 [BCnt, BCnt div RunTime])
+                                       end,
+                                       if (RunTime =:= 0) ->
+                                               "-";
+                                          true ->
+                                               ?TTEST_LIB:format("~p => ~p iterations / ms",
+                                                                 [Cnt, Cnt div RunTime])
+                                       end
+                                      ]),
+                                   {ok, maps:remove(result, State)};
+
+                               #{status  := Failure,
+                                 runtime := RunTime,
+                                 sid     := SID,
+                                 rid     := RID,
+                                 scnt    := SCnt,
+                                 rcnt    := RCnt,
+                                 bcnt    := BCnt,
+                                 num     := Num} ->
+                                   ?SEV_EPRINT("Time Test failed: "
+                                               "~n   ~p"
+                                               "~n"
+                                               "~nwhen"
+                                               "~n"
+                                               "~n   Run Time:       ~s"
+                                               "~n   Send ID:        ~p"
+                                               "~n   Recv ID:        ~p"
+                                               "~n   Send Count:     ~p"
+                                               "~n   Recv Count:     ~p"
+                                               "~n   Byte Count:     ~p"
+                                               "~n   Num Iterations: ~p",
+                                               [Failure,
+                                                ?TTEST_LIB:format_time(RunTime),
+                                                SID, RID, SCnt, RCnt, BCnt, Num]),
+                                   {error, Failure}
+                           end
+                   end},
+
+         %% This is just so that the printout above shall have time to come
+         %% out before then end of the test case.
+         ?SEV_SLEEP(?SECS(1)),
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    Domain = maps:get(domain, InitState),
+    LHost  = local_host(),
+    LAddr  = which_local_addr(Domain),
+
+    i("start server evaluator"),
+    ServerInitState = #{host   => LHost,
+			addr   => LAddr,
+                        domain => Domain,
+                        mod    => maps:get(server_mod,    InitState),
+                        active => maps:get(server_active, InitState)},
+    Server          = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start client evaluator"),
+    ClientInitState = #{host            => LHost,
+			addr            => LAddr,
+                        domain          => Domain,
+                        mod             => maps:get(client_mod,      InitState),
+                        active          => maps:get(client_active,   InitState),
+                        msg_id          => maps:get(msg_id,          InitState),
+                        max_outstanding => maps:get(max_outstanding, InitState),
+                        runtime         => maps:get(runtime,         InitState)},
+    Client          = ?SEV_START("client", ClientSeq, ClientInitState),
+    
+    i("start 'tester' evaluator"),
+    TesterInitState = #{domain        => Domain,
+			msg_id        => maps:get(msg_id,        InitState),
+                        client        => Client#ev.pid,
+			client_mod    => maps:get(client_mod,    InitState),
+			client_active => maps:get(client_active, InitState),
+                        server        => Server#ev.pid,
+                        server_mod    => maps:get(server_mod,    InitState),
+                        server_active => maps:get(server_active, InitState)},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator(s)"),
+    ok = ?SEV_AWAIT_FINISH([Server, Client, Tester]).
+
+
+
+ttest_tcp_server_start(Node, Domain, gen, Active) ->
+    TransportMod = socket_test_ttest_tcp_gen,
+    Transport    = {TransportMod, #{domain => Domain}},
+    socket_test_ttest_tcp_server:start_monitor(Node, Transport, Active);
+ttest_tcp_server_start(Node, Domain, sock, Active) ->
+    TransportMod = socket_test_ttest_tcp_socket,
+    Transport    = {TransportMod, #{domain => Domain,
+                                    async  => true,
+                                    method => plain}},
+    socket_test_ttest_tcp_server:start_monitor(Node, Transport, Active).
+
+ttest_tcp_server_stop(Pid) ->
+    socket_test_ttest_tcp_server:stop(Pid).
+
+ttest_tcp_client_start(Node,
+                       Notify,
+                       Domain, gen,
+                       ServerInfo, Active, MsgID, MaxOutstanding, RunTime) ->
+    TransportMod = socket_test_ttest_tcp_gen,
+    Transport    = {TransportMod, #{domain => Domain}},    
+    socket_test_ttest_tcp_client:start_monitor(Node,
+                                               Notify,
+                                               Transport,
+                                               ServerInfo,
+                                               Active,
+                                               MsgID, MaxOutstanding, RunTime);
+ttest_tcp_client_start(Node,
+                       Notify,
+                       Domain, sock,
+                       ServerInfo, Active, MsgID, MaxOutstanding, RunTime) ->
+    TransportMod = socket_test_ttest_tcp_socket,
+    Transport    = {TransportMod, #{domain => Domain,
+                                    async  => true,
+                                    method => plain}},
+    socket_test_ttest_tcp_client:start_monitor(Node,
+                                               Notify,
+                                               Transport,
+                                               ServerInfo,
+                                               Active,
+                                               MsgID, MaxOutstanding, RunTime).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+-define(TTEST_MANAGER, esock_ttest_manager).
+
+-record(ttest_report_id,
+        {domain        :: socket:domain(),
+         serv_trans    :: gen | sock,
+         serv_active   :: once | boolean(),
+         client_trans  :: gen | sock,
+         client_active :: once | boolean(),
+         msg_id        :: small | medium | large}).
+
+-record(ttest_report, {id    :: #ttest_report_id{},
+                       time  :: non_neg_integer(),
+                       bytes :: non_neg_integer(),
+                       msgs  :: non_neg_integer()}).
+
+-spec ttest_report(Domain      :: socket:domain(),
+                   ServTrans   :: gen | sock, ServActive   :: once | boolean(),
+                   ClientTrans :: gen | sock, ClientActive :: once | boolean(),
+                   MsgID       :: 1 | 2 | 3,
+                   RunTime     :: non_neg_integer(),
+                   NumBytes    :: non_neg_integer(),
+                   NumMsgs     :: non_neg_integer()) -> ok.
+
+ttest_report(Domain,
+             ServTrans,   ServActive,
+             ClientTrans, ClientActive,
+             MsgID,
+             RunTime,
+             NumBytes,
+             NumMsgs) ->
+    ID = #ttest_report_id{domain        = Domain,
+                          serv_trans    = ServTrans,
+                          serv_active   = ServActive,
+                          client_trans  = ClientTrans,
+                          client_active = ClientActive,
+                          msg_id        = ttest_msg_id_num_to_name(MsgID)},
+    Report = #ttest_report{id    = ID,
+                           time  = RunTime,
+                           bytes = NumBytes,
+                           msgs  = NumMsgs},
+    %% If we run just one test case, the group init has never been run
+    %% and therefor the ttest manager is not running (we also don't actually
+    %% care about collecting reports in that case).
+    (catch global:send(?TTEST_MANAGER, Report)),
+    ok.
+
+ttest_msg_id_num_to_name(1) ->
+    small;
+ttest_msg_id_num_to_name(2) ->
+    medium;
+ttest_msg_id_num_to_name(3) ->
+    large.
+    
+ttest_manager_start() ->
+    Self = self(),
+    {Pid, MRef} = spawn_monitor(fun() -> ttest_manager_init(Self) end),
+    receive
+        {ttest_manager_started, Pid} ->
+            erlang:demonitor(MRef, [flush]),
+            ok;
+        {'DOWN', MRef, process, Pid, Reason} ->
+            exit({failed_starting, ttest_manager, Reason})
+    after 5000 ->
+            exit(Pid, kill),
+            exit({failed_starting, ttest_manager, timeout})
+    end.
+
+ttest_manager_stop() ->
+    case global:whereis_name(?TTEST_MANAGER) of
+        Pid when is_pid(Pid) ->
+            erlang:monitor(process, Pid),
+            global:send(?TTEST_MANAGER, stop),
+            receive
+                {'DOWN', _MRef, process, Pid, _} ->
+                    ok
+            after 10000 ->
+                    exit(Pid, kill),
+                    ok
+            end;
+        _ ->
+            ok
+    end.
+
+ttest_manager_init(Parent) ->
+    yes = global:register_name(?TTEST_MANAGER, self()),
+    ets:new(?TTEST_MANAGER, 
+            [{keypos, #ttest_report.id}, named_table, protected, ordered_set]),
+    Parent ! {ttest_manager_started, self()},
+    ttest_manager_loop().
+
+ttest_manager_loop() ->
+    receive
+        stop ->
+            ?LOGGER:format("manager stopping~n", []),
+            ttest_manager_done();
+
+        #ttest_report{id    = _ID,
+                      time  = _RunTime,
+                      bytes = _NumBytes,
+                      msgs  = _NumMsgs} = Report ->
+            true = ets:insert_new(?TTEST_MANAGER, Report),
+            ttest_manager_loop()
+    end.
+
+%% We are supposed to pretty print the result here...
+ttest_manager_done() ->
+    format_reports(inet),
+    %% format_reports(inet6),
+    ets:delete(?TTEST_MANAGER),
+    exit(normal).
+
+format_reports(Domain) ->
+    ?LOGGER:format("Domain ~w reports:~n~n", [Domain]),
+    format_reports(Domain, small),
+    format_reports(Domain, medium),
+    format_reports(Domain, large).
+    
+format_reports(Domain, MsgID) when is_atom(MsgID) ->
+    case which_ttest_reports(Domain, MsgID) of
+        [] ->
+            ?LOGGER:format("   No ~w reports~n~n", [MsgID]);
+        Reports ->
+            ?LOGGER:format("   ~w reports: ~n", [MsgID]),
+            lists:foreach(fun(R) -> format_report(R) end, Reports)
+    end.
+
+%% This should really be a table like this:
+%%
+%%             client
+%% server      gen(false)  gen(once)  gen(true)  sock(false)  sock(once)  sock(true)
+%% gen(false)  nnn
+%% gen(once)   nnn
+%% gen(true)   nnn
+%% sock(false) nnn
+%% sock(once)  nnn
+%% sock(true)  nnn
+%%
+format_report(#ttest_report{id    = #ttest_report_id{serv_trans    = STrans,
+                                                     serv_active   = SActive,
+                                                     client_trans  = CTrans,
+                                                     client_active = CActive},
+                            time  = RunTime,
+                            bytes = BCnt,
+                            msgs  = MCnt}) ->
+    ?LOGGER:format("      server ~w[~w] - client ~w[~w] => "
+                   "~n         Run Time: ~s"
+                   "~n         Bytes:    ~s"
+                   "~n         Messages: ~s"
+                   "~n", [STrans, SActive, CTrans, CActive,
+                          ?TTEST_LIB:format_time(RunTime),
+                          if ((BCnt =:= 0) orelse (RunTime =:= 0)) ->
+                                  ?TTEST_LIB:format("~w, ~w",
+                                                    [BCnt, RunTime]);
+                             true ->
+                                  ?TTEST_LIB:format("~p => ~p byte / ms",
+                                                    [BCnt, BCnt div RunTime])
+                          end,
+                          if (RunTime =:= 0) ->
+                                  "-";
+                             true ->
+                                  ?TTEST_LIB:format("~p => ~p iterations / ms",
+                                                    [MCnt, MCnt div RunTime])
+                          end]),
+    ok.
+
+
+which_ttest_reports(Domain, all) ->
+    [R || R = #ttest_report{id = #ttest_report_id{domain = D}} <- 
+              ets:tab2list(?TTEST_MANAGER), Domain =:= D];
+which_ttest_reports(Domain, MsgID) ->
+    [R || R = #ttest_report{id = #ttest_report_id{domain = D, msg_id = MID}} <- 
+              ets:tab2list(?TTEST_MANAGER), (Domain =:= D) andalso (MsgID =:= MID)].
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This mechanism has only one purpose: So that we are able to kill
+%% the node-starter process if it takes to long. The node-starter
+%% runs on the local node.
+%% This crapola is hopefully temporary, but we have seen that on
+%% some platforms the ct_slave:start simply hangs.
+-define(NODE_START_TIMEOUT, 10000).
+start_node(Host, NodeName) ->
+    start_node(Host, NodeName, ?NODE_START_TIMEOUT).
+
+start_node(Host, NodeName, Timeout) ->
+    {NodeStarter, _} =
+        spawn_monitor(fun() -> exit(start_unique_node(Host, NodeName)) end),
+    receive
+        {'DOWN', _, process, NodeStarter, Result} ->
+            %% i("Node Starter (~p) reported: ~p", [NodeStarter, Result]),
+            Result
+    after Timeout ->
+            exit(NodeStarter, kill),
+            {error, {failed_starting_node, NodeName, timeout}}
+    end.
+
+start_unique_node(Host, NodeName) ->
+    UniqueNodeName = f("~w_~w", [NodeName, erlang:system_time(millisecond)]),
+    case do_start_node(Host, UniqueNodeName) of
+        {ok, _} = OK ->
+            global:sync(),
+            %% i("Node ~p started: "
+            %%    "~n   Nodes:        ~p"
+            %%    "~n   Logger:       ~p"
+            %%    "~n   Global Names: ~p",
+            %%    [NodeName, nodes(),
+            %%     global:whereis_name(socket_test_logger),
+            %%     global:registered_names()]),
+            OK;
+        {error, Reason, _} ->
+            {error, Reason}
+    end.
+
+do_start_node(Host, NodeName) when is_list(NodeName) ->
+    do_start_node(Host, list_to_atom(NodeName));
+do_start_node(Host, NodeName) when is_atom(NodeName) ->
+    Dir   = filename:dirname(code:which(?MODULE)),
+    Flags = "-pa " ++ Dir,
+    Opts  = [{monitor_master, true}, {erl_flags, Flags}],
+    ct_slave:start(Host, NodeName, Opts).
+
+
+stop_node(Node) ->
+    case ct_slave:stop(Node) of
+        {ok, _} ->
+            ok;
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+    
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+sock_open(Domain, Type, Proto) ->
+    try socket:open(Domain, Type, Proto) of
+        {ok, Socket} ->
+            Socket;
+        {error, Reason} ->
+            ?FAIL({open, Reason})
+    catch
+        C:E:S ->
+            ?FAIL({open, C, E, S})
+    end.
+
+
+sock_connect(Sock, SockAddr) ->
+    try socket:connect(Sock, SockAddr) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            ?FAIL({connect, Reason})
+    catch
+        C:E:S ->
+            ?FAIL({connect, C, E, S})
+    end.
+    
+sock_sockname(Sock) ->
+    try socket:sockname(Sock) of
+        {ok, SockAddr} ->
+            SockAddr;
+        {error, Reason} ->
+            ?FAIL({sockname, Reason})
+    catch
+        C:E:S ->
+            ?FAIL({sockname, C, E, S})
+    end.
+    
+sock_close(Sock) ->
+    try socket:close(Sock) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            i("sock_close -> error: ~p", [Reason]),
+            ?FAIL({close, Reason})
+    catch
+        C:E:S ->
+            i("sock_close -> failed: ~p, ~p, ~p", [C, E, S]),
+            ?FAIL({close, C, E, S})
+    end.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+local_host() ->
+    try net_adm:localhost() of
+        Host when is_list(Host) ->
+	    %% Convert to shortname if long
+	    case string:tokens(Host, [$.]) of
+		[H|_] ->
+		    list_to_atom(H)
+	    end
+    catch
+        C:E:S ->
+            erlang:raise(C, E, S)
+    end.
+
+
+%% The point of this is to "ensure" that paths from different test runs
+%% don't clash.
+mk_unique_path() ->
+    [NodeName | _] = string:tokens(atom_to_list(node()), [$@]),
+    Path = ?LIB:f("/tmp/esock_~s_~w", [NodeName, erlang:system_time(nanosecond)]),
+    ensure_unique_path(Path).
+
+ensure_unique_path(Path) ->
+    case file:read_file_info(Path) of
+        {ok, _} -> % Ouch, append a unique ID and try again
+            ensure_unique_path(Path, 1);
+        {error, _} ->
+            %% We assume this means it does not exist yet...
+            %% If we have several process in paralell trying to create
+            %% (unique) path's, then we are in trouble. To *really* be
+            %% on the safe side we should have a (central) path registry...
+            Path
+    end.
+
+ensure_unique_path(Path, ID) when (ID < 100) -> % If this is not enough...
+    NewPath = ?LIB:f("~s_~w", [Path, ID]),
+    case file:read_file_info(NewPath) of
+        {ok, _} -> % Ouch, this also existed, increment and try again
+            ensure_unique_path(Path, ID + 1);
+        {error, _} -> % We assume this means it does not exist yet...
+            NewPath
+    end;
+ensure_unique_path(_, _) -> 
+    skip("Could not create unique path").
+    
+            
+which_local_socket_addr(local = Domain) ->
+    #{family => Domain,
+      path   => mk_unique_path()};
+
+%% This gets the local socket address (not 127.0...)
+%% We should really implement this using the (new) net module,
+%% but until that gets the necessary functionality...
+which_local_socket_addr(Domain) ->
+    case ?LIB:which_local_host_info(Domain) of
+        {ok, #{addr := Addr}} ->
+            #{family => Domain,
+              addr   => Addr};
+        {error, Reason} ->
+            ?FAIL(Reason)
+    end.
+
+
+
+which_local_addr(local = _Domain) ->
+    mk_unique_path();
+
+%% This gets the local address (not 127.0...)
+%% We should really implement this using the (new) net module,
+%% but until that gets the necessary functionality...
+which_local_addr(Domain) ->
+    ?LIB:which_local_addr(Domain).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Here are all the *general* test case condition functions.
+
+%% We also need (be able) to figure out the the multicast address,
+%% which we only support for some platforms (linux and sunos).
+%% We don't do that here, but since we can only do that (find a
+%% multicast address) for specific platforms, we check that we are
+%% on of those platforms here.
+has_support_ip_multicast() ->
+    case os:type() of
+        {unix, OsName} when (OsName =:= linux) orelse
+                            (OsName =:= sunos) ->
+            case ?LIB:which_local_host_info(inet) of
+                {ok, #{flags := Flags}} ->
+                    case lists:member(multicast, Flags) of
+                        true ->
+                            ok;
+                        false ->
+                            not_supported(multicast)
+                    end;
+                {error, Reason} ->
+                    not_supported({multicast, Reason})
+            end;
+        {unix, OsName} ->
+            skip(?F("Not Supported: platform ~w", [OsName]));
+        Type ->
+            skip(?F("Not Supported: platform ~p", [Type]))
+    end.
+
+has_support_sock_acceptconn() ->
+    has_support_socket_option_sock(acceptconn).
+
+has_support_sock_bindtodevice() ->
+    has_support_socket_option_sock(bindtodevice).
+
+has_support_sock_broadcast() ->
+    has_support_socket_option_sock(broadcast),
+    case ?LIB:which_local_host_info(inet) of
+        {ok, #{flags := Flags}} ->
+            case lists:member(broadcast, Flags) of
+                true ->
+                    ok;
+                false ->
+                    not_supported({broadcast, Flags})
+            end;
+        {error, Reason} ->
+            not_supported({broadcast, Reason})
+    end.
+
+has_support_sock_debug() ->
+    has_support_socket_option_sock(debug).
+
+has_support_sock_domain() ->
+    has_support_socket_option_sock(domain).
+
+has_support_sock_dontroute() ->
+    has_support_socket_option_sock(dontroute).
+
+has_support_sock_keepalive() ->
+    has_support_socket_option_sock(keepalive).
+
+
+has_support_ip_add_membership() ->
+    has_support_socket_option_ip(add_membership).
+
+has_support_ip_drop_membership() ->
+    has_support_socket_option_ip(drop_membership).
+
+
+has_support_socket_option_ip(Opt) ->
+    has_support_socket_option(ip, Opt).
+
+has_support_socket_option_sock(Opt) ->
+    has_support_socket_option(socket, Opt).
+
+has_support_socket_option(Level, Option) ->
+    case socket:supports(options, Level, Option) of
+        true ->
+            ok;
+        false ->
+            skip(?F("Not Supported: ~w option ~w", [Level, Option]))
+    end.
+
+
+
+
+unix_domain_socket_host_cond() ->
+    unix_domain_socket_host_cond(os:type(), os:version()).
+
+unix_domain_socket_host_cond({unix, linux}, {M, _, _}) when (M < 3) ->
+    skip("TC may not work on this version");
+unix_domain_socket_host_cond(_, _) ->
+    ok.
+
+has_support_unix_domain_socket() ->
+    case os:type() of
+        {win32, _} ->
+            skip("Not supported");
+        _ ->
+            case socket:supports(local) of
+                true ->
+                    ok;
+                false ->
+                    skip("Not supported")
+            end
+    end.
+
+
+%% The idea is that this function shall test if the test host has 
+%% support for IPv6. If not, there is no point in running IPv6 tests.
+%% Currently we just skip.
+has_support_ipv6() ->
+    ?LIB:has_support_ipv6().
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+unlink_path(Path) ->
+    unlink_path(Path, fun() -> ok end, fun() -> ok end).
+
+unlink_path(Path, Success, Failure) when is_list(Path) andalso 
+                                         is_function(Success, 0) andalso
+                                         is_function(Failure, 0) ->
+    ?SEV_IPRINT("try unlink path: "
+                "~n   ~s", [Path]),
+    case os:cmd("unlink " ++ Path) of
+        "" ->
+            ?SEV_IPRINT("path unlinked: "
+                        "~n   Path: ~s", [Path]),
+            Success();
+        Result ->
+            ?SEV_EPRINT("unlink maybe failed: "
+                        "~n   Path: ~s"
+                        "~n   Res:  ~s", [Path, Result]),
+            Failure()
+    end;
+unlink_path(_, _, _) ->
+    ok.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+not_supported(What) ->
+    skip({not_supported, What}).
+
+not_yet_implemented() ->
+    skip("not yet implemented").
+
+skip(Reason) ->
+    throw({skip, Reason}).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+t() ->
+    ts(ms).
+
+ts(ms) ->
+    erlang:monotonic_time(milli_seconds).
+
+tdiff({A1, B1, C1} = _T1x, {A2, B2, C2} = _T2x) ->
+    T1 = A1*1000000000+B1*1000+(C1 div 1000), 
+    T2 = A2*1000000000+B2*1000+(C2 div 1000), 
+    T2 - T1.
+
+
+formated_timestamp() ->
+    format_timestamp(os:timestamp()).
+
+format_timestamp({_N1, _N2, _N3} = TS) ->
+    {_Date, Time}   = calendar:now_to_local_time(TS),
+    %% {YYYY,MM,DD}   = Date,
+    {Hour,Min,Sec} = Time,
+    %% FormatTS = 
+    %%     io_lib:format("~.4w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w.~w",
+    %%                   [YYYY, MM, DD, Hour, Min, Sec, N3]),  
+    FormatTS = io_lib:format("~.2.0w:~.2.0w:~.2.0w", [Hour, Min, Sec]),  
+    lists:flatten(FormatTS).
+
+   
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+set_tc_name(N) when is_atom(N) ->
+    set_tc_name(atom_to_list(N));
+set_tc_name(N) when is_list(N) ->
+    put(tc_name, N).
+
+%% get_tc_name() ->
+%%     get(tc_name).
+
+tc_begin(TC) ->
+    OldVal = process_flag(trap_exit, true),
+    put(old_trap_exit, OldVal),
+    set_tc_name(TC),
+    tc_print("begin ***",
+             "~n----------------------------------------------------~n", "").
+    
+tc_end(Result) when is_list(Result) ->
+    OldVal = erase(old_trap_exit),
+    process_flag(trap_exit, OldVal),
+    tc_print("done: ~s", [Result], 
+             "", "----------------------------------------------------~n~n"),
+    ok.
+
+%% *** tc_try/2,3 ***
+%% Case:      Basically the test case name
+%% TCCondFun: A fun that is evaluated before the actual test case
+%%            The point of this is that it can performs checks to
+%%            see if we shall run the test case at all.
+%%            For instance, the test case may only work in specific
+%%            conditions.
+%% FCFun:     The test case fun
+tc_try(Case, TCFun) ->
+    TCCondFun = fun() -> ok end,
+    tc_try(Case, TCCondFun, TCFun).
+
+tc_try(Case, TCCondFun, TCFun) 
+  when is_atom(Case) andalso
+       is_function(TCCondFun, 0) andalso
+       is_function(TCFun, 0) ->
+    tc_begin(Case),
+    try TCCondFun() of
+        ok ->
+            try 
+                begin
+                    TCFun(),
+                    ?SLEEP(?SECS(1)),
+                    tc_end("ok")
+                end
+            catch
+                C:{skip, _} = SKIP when ((C =:= throw) orelse (C =:= exit)) ->
+                    %% i("catched[tc] (skip): "
+                    %%   "~n   C:    ~p"
+                    %%   "~n   SKIP: ~p"
+                    %%   "~n", [C, SKIP]),
+                    tc_end( f("skipping(catched,~w,tc)", [C]) ),
+                    SKIP;
+                C:E:S ->
+                    %% i("catched[tc]: "
+                    %%   "~n   C: ~p"
+                    %%   "~n   E: ~p"
+                    %%   "~n   S: ~p"
+                    %%    "~n", [C, E, S]),
+                    tc_end( f("failed(catched,~w,tc)", [C]) ),
+                    erlang:raise(C, E, S)
+            end;
+        {skip, _} = SKIP ->
+            tc_end("skipping(tc)"),
+            SKIP;
+        {error, Reason} ->
+            tc_end("failed(tc)"),
+            exit({tc_cond_failed, Reason})
+    catch
+        C:{skip, _} = SKIP when ((C =:= throw) orelse (C =:= exit)) ->
+            %% i("catched[cond] (skip): "
+            %%   "~n   C:    ~p"
+            %%   "~n   SKIP: ~p"
+            %%   "~n", [C, SKIP]),
+            tc_end( f("skipping(catched,~w,cond)", [C]) ),
+            SKIP;
+        C:E:S ->
+            %% i("catched[cond]: "
+            %%   "~n   C: ~p"
+            %%   "~n   E: ~p"
+            %%   "~n   S: ~p"
+            %%   "~n", [C, E, S]),
+            tc_end( f("failed(catched,~w,cond)", [C]) ),
+            erlang:raise(C, E, S)
+    end.
+
+
+tc_print(F, Before, After) ->
+    tc_print(F, [], Before, After).
+
+tc_print(F, A, Before, After) ->
+    Name = tc_which_name(),
+    FStr = f("*** [~s][~s][~p] " ++ F ++ "~n", 
+             [formated_timestamp(),Name,self()|A]),
+    io:format(user, Before ++ FStr ++ After, []).
+
+tc_which_name() ->
+    case get(tc_name) of
+        undefined ->
+            case get(sname) of
+                undefined ->
+                    "";
+                SName when is_list(SName) ->
+                    SName
+            end;
+        Name when is_list(Name) ->
+            Name
+    end.
+    
+   
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+l2a(S) when is_list(S) ->
+    list_to_atom(S).
+
+l2b(L) when is_list(L) ->
+    list_to_binary(L).
+
+b2l(B) when is_binary(B) ->
+    binary_to_list(B).
+
+f(F, A) ->
+    lists:flatten(io_lib:format(F, A)).
+
+%% p(F) ->
+%%     p(F, []).
+
+%% p(F, A) ->
+%%     p(F, A, "", "").
+
+%% p(F, A, Before, After) when is_list(Before) andalso is_list(After) ->
+%%     TcName = 
+%%         case get(tc_name) of
+%%             undefined ->
+%%                 case get(sname) of
+%%                     undefined ->
+%%                         "";
+%%                     SName when is_list(SName) ->
+%%                         SName
+%%                 end;
+%%             Name when is_list(Name) ->
+%%                 Name
+%%         end,
+%%     FStr = f("*** [~s][~s][~p] " ++ F ++ "~n", 
+%%              [formated_timestamp(),TcName,self()|A]),
+%%     i(Before ++ FStr ++ After, []).
+
+
+%% d(F, A) ->
+%%     d(get(dbg_fd), F, A).
+
+%% d(undefined, F, A) ->
+%%     [NodeNameStr|_] = string:split(atom_to_list(node()), [$@]),
+%%     DbgFileName = f("~s-dbg.txt", [NodeNameStr]),
+%%     case file:open(DbgFileName, [write]) of
+%%         {ok, FD} ->
+%%             put(dbg_fd, FD),
+%%             d(FD, F, A);
+%%         {error, Reason} ->
+%%             exit({failed_open_dbg_file, Reason})
+%%     end;
+%% d(FD, F, A) ->
+%%     io:format(FD, "~s~n", [f("[~s] " ++ F, [formated_timestamp()|A])]).
+
+i(F) ->
+    i(F, []).
+
+i(F, A) ->
+    FStr = f("[~s] " ++ F, [formated_timestamp()|A]),
+    io:format(user, FStr ++ "~n", []),
+    io:format(FStr, []).
+
diff --git a/erts/emulator/test/socket_test_evaluator.erl b/erts/emulator/test/socket_test_evaluator.erl
new file mode 100644
index 0000000000..694f0d5f1e
--- /dev/null
+++ b/erts/emulator/test/socket_test_evaluator.erl
@@ -0,0 +1,664 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_evaluator).
+
+%% Evaluator control functions
+-export([
+         start/3,
+         await_finish/1
+        ]).
+
+%% Functions used by evaluators to interact with eachother
+-export([
+         %% Announce functions
+         %% (Send an announcement from one evaluator to another)
+         announce_start/1,     announce_start/2,
+         announce_continue/2,  announce_continue/3,
+         announce_ready/2,     announce_ready/3,
+         announce_terminate/1,
+
+         %% Await functions
+         %% (Wait for an announcement from another evaluator)
+         await_start/0,        await_start/1,
+         await_continue/3,     await_continue/4,
+         await_ready/3,        await_ready/4,
+         await_terminate/2,    await_terminate/3,
+         await_termination/1,  await_termination/2
+        ]).
+
+%% Utility functions
+-export([
+         iprint/2, % Info  printouts
+         eprint/2  % Error printouts
+        ]).
+
+-export_type([
+              ev/0,
+              initial_evaluator_state/0,
+              evaluator_state/0,
+              command_fun/0,
+              command/0
+             ]).
+
+
+-include("socket_test_evaluator.hrl").
+
+-type ev() :: #ev{}.
+-type initial_evaluator_state() :: map().
+-type evaluator_state() :: term().
+-type command_fun() :: 
+        fun((State :: evaluator_state()) -> ok) |
+        fun((State :: evaluator_state()) -> {ok, evaluator_state()}) |
+        fun((State :: evaluator_state()) -> {error, term()}).
+
+-type command() :: #{desc  := string(),
+                     cmd   := command_fun()}.
+
+
+%% ============================================================================
+
+-define(LIB,                    socket_test_lib).
+-define(LOGGER,                 socket_test_logger).
+
+-define(EXTRA_NOTHING,          '$nothing').
+-define(ANNOUNCEMENT_START,     '$start').
+-define(ANNOUNCEMENT_READY,     '$ready').
+-define(ANNOUNCEMENT_CONTINUE,  '$continue').
+-define(ANNOUNCEMENT_TERMINATE, '$terminate').
+
+-define(START_NAME_NONE,        '$no-name').
+-define(START_SLOGAN,           ?ANNOUNCEMENT_START).
+-define(TERMINATE_SLOGAN,       ?ANNOUNCEMENT_TERMINATE).
+
+
+%% ============================================================================
+
+-spec start(Name, Seq, Init) -> ev() when
+      Name :: string(),
+      Seq  :: [command()],
+      Init :: initial_evaluator_state().
+                             
+start(Name, Seq, InitState) 
+  when is_list(Name) andalso is_list(Seq) andalso (Seq =/= []) ->
+    %% Make sure 'parent' is not already used
+    case maps:find(parent, InitState) of
+        {ok, _} ->
+            erlang:error({already_used, parent});
+        error ->
+            InitState2 = InitState#{parent => self()},
+            Pid = erlang:spawn_link(
+                    fun() -> init(Name, Seq, InitState2) end),
+            %% MRef = erlang:monitor(process, Pid),
+            #ev{name = Name, pid = Pid}%, mref = MRef}
+    end.
+
+init(Name, Seq, Init) ->
+    put(sname, Name),
+    process_flag(trap_exit, true),
+    loop(1, Seq, Init).
+
+loop(_ID, [], FinalState) ->
+    exit(FinalState);
+loop(ID, [#{desc := Desc,
+            cmd  := Cmd}|Cmds], State) when is_function(Cmd, 1) ->
+    iprint("evaluate command ~2w: ~s", [ID, Desc]),
+    try Cmd(State) of
+        ok ->
+            loop(ID + 1, Cmds, State);
+        {ok, NewState} ->
+            loop(ID + 1, Cmds, NewState);
+        {skip, Reason} ->
+            ?SEV_IPRINT("command ~w skip: "
+                        "~n   ~p", [ID, Reason]),
+            exit({skip, Reason});
+        {error, Reason} ->
+            ?SEV_EPRINT("command ~w failed: "
+                        "~n   ~p", [ID, Reason]),
+            exit({command_failed, ID, Reason, State})
+    catch
+        C:{skip, command} = E:_ when ((C =:= throw) orelse (C =:= exit)) ->
+            %% Secondary skip
+            exit(E);
+        C:{skip, R} = E:_ when ((C =:= throw) orelse (C =:= exit)) ->
+            ?SEV_IPRINT("command ~w skip catched(~w): "
+                        "~n   Reason: ~p", [ID, C, R]),
+            exit(E);
+        C:E:S ->
+            ?SEV_EPRINT("command ~w crashed: "
+                        "~n   Class:      ~p"
+                        "~n   Error:      ~p"
+                        "~n   Call Stack: ~p", [ID, C, E, S]),
+            exit({command_crashed, ID, {C,E,S}, State})
+    end.
+
+
+%% ============================================================================
+
+-spec await_finish(Evs) -> term() when
+      Evs :: [ev()].
+
+await_finish(Evs) ->
+    await_finish(Evs, [], []).
+
+await_finish([], _, []) ->
+    ok;
+await_finish([], _OK, Fails) ->
+    ?SEV_EPRINT("Fails: "
+		"~n   ~p", [Fails]),
+    Fails;
+await_finish(Evs, OK, Fails) ->
+    receive
+        %% Successfull termination of evaluator
+        {'DOWN', _MRef, process, Pid, normal} ->
+            {Evs2, OK2, Fails2} = await_finish_normal(Pid, Evs, OK, Fails),
+            await_finish(Evs2, OK2, Fails2);
+        {'EXIT', Pid, normal} ->
+            {Evs2, OK2, Fails2} = await_finish_normal(Pid, Evs, OK, Fails),
+            await_finish(Evs2, OK2, Fails2);
+
+        %% The evaluator can skip the test case:
+        {'DOWN', _MRef, process, Pid, {skip, Reason}} ->
+            %% ?SEV_IPRINT("await_finish -> skip (down) received: "
+            %%             "~n   Pid:    ~p"
+            %%             "~n   Reason: ~p", [Pid, Reason]),
+            await_finish_skip(Pid, Reason, Evs, OK);
+        {'EXIT', Pid, {skip, Reason}} ->
+            %% ?SEV_IPRINT("await_finish -> skip (exit) received: "
+            %%             "~n   Pid:    ~p"
+            %%             "~n   Reason: ~p", [Pid, Reason]),
+            await_finish_skip(Pid, Reason, Evs, OK);
+
+        %% Evaluator failed
+        {'DOWN', _MRef, process, Pid, Reason} ->
+            %% ?SEV_IPRINT("await_finish -> fail (down) received: "
+            %%             "~n   Pid:    ~p"
+            %%             "~n   Reason: ~p", [Pid, Reason]),
+            {Evs2, OK2, Fails2} =
+                await_finish_fail(Pid, Reason, Evs, OK, Fails),
+            await_finish(Evs2, OK2, Fails2);
+        {'EXIT', Pid, Reason} ->
+            %% ?SEV_IPRINT("await_finish -> fail (exit) received: "
+            %%             "~n   Pid:    ~p"
+            %%             "~n   Reason: ~p", [Pid, Reason]),
+            {Evs2, OK2, Fails2} =
+                await_finish_fail(Pid, Reason, Evs, OK, Fails),
+            await_finish(Evs2, OK2, Fails2)
+    end.
+
+
+await_finish_normal(Pid, Evs, OK, Fails) ->
+    case lists:keysearch(Pid, #ev.pid, Evs) of
+        {value, #ev{name = Name}} ->
+            iprint("evaluator '~s' (~p) success", [Name, Pid]),
+            NewEvs = lists:keydelete(Pid, #ev.pid, Evs),
+            {NewEvs, [Pid|OK], Fails};
+        false ->
+            case lists:member(Pid, OK) of
+                true ->
+                    ok;
+                false ->
+                    iprint("unknown process ~p died (normal)", [Pid]),
+                    ok
+            end,
+            {Evs, OK, Fails}
+    end.
+
+await_finish_skip(Pid, Reason, Evs, OK) ->
+    Evs2 =
+        case lists:keysearch(Pid, #ev.pid, Evs) of
+            {value, #ev{name = Name}} ->
+                ?SEV_IPRINT("evaluator '~s' (~p) issued SKIP: "
+                            "~n   ~p", [Name, Pid, Reason]),
+                lists:keydelete(Pid, #ev.pid, Evs);
+            false ->
+                case lists:member(Pid, OK) of
+                    true ->
+                        ?SEV_IPRINT("already terminated (ok) process ~p skip"
+                                    "~n   ~p", [Pid]),
+                        ok;
+                    false ->
+                        ?SEV_IPRINT("unknown process ~p issued SKIP: "
+                                    "~n   ~p", [Pid, Reason]),
+                        iprint("unknown process ~p issued SKIP: "
+                               "~n   ~p", [Pid, Reason])
+                end,
+                Evs
+        end,
+    await_evs_terminated(Evs2),
+    ?LIB:skip(Reason).
+
+await_evs_terminated(Evs) ->
+    Instructions =
+        [
+         %% Just wait for the evaluators to die on their own
+         {fun() -> ?SEV_IPRINT("await (no action) evs termination") end,
+          fun(_) -> ok end},
+
+         %% Send them a skip message, causing the evaluators to
+         %% die with a skip reason.
+         {fun() -> ?SEV_IPRINT("await (send skip message) evs termination") end,
+          fun(#ev{pid = Pid}) -> Pid ! skip end},
+
+         %% And if nothing else works, try to kill the remaining evaluators
+         {fun() -> ?SEV_IPRINT("await (issue exit kill) evs termination") end,
+          fun(#ev{pid = Pid}) -> exit(Pid, kill) end}],
+
+    await_evs_terminated(Evs, Instructions).
+
+await_evs_terminated([], _) ->
+    ok;
+await_evs_terminated(Evs, []) ->
+    {error, {failed_terminated, [P||#ev{pid=P} <- Evs]}};
+await_evs_terminated(Evs, [{Inform, Command}|Instructions]) ->
+    Inform(),
+    lists:foreach(Command, Evs),
+    RemEvs = await_evs_termination(Evs),
+    await_evs_terminated(RemEvs, Instructions).
+
+await_evs_termination(Evs) ->
+    await_evs_termination(Evs, 2000).
+
+await_evs_termination([], _Timeout) ->
+    [];
+await_evs_termination(Evs, Timeout) ->
+    T = t(),
+    receive
+        {'DOWN', _MRef, process, Pid, _Reason} ->
+            %% ?SEV_IPRINT("await_evs_termination -> DOWN: "
+            %%             "~n   Pid:    ~p"
+            %%             "~n   Reason: ~p", [Pid, Reason]),
+            Evs2 = lists:keydelete(Pid, #ev.pid, Evs),
+            await_evs_termination(Evs2, tdiff(T, t()));
+        {'EXIT', Pid, _Reason} ->
+            %% ?SEV_IPRINT("await_evs_termination -> EXIT: "
+            %%             "~n   Pid:    ~p"
+            %%             "~n   Reason: ~p", [Pid, Reason]),
+            Evs2 = lists:keydelete(Pid, #ev.pid, Evs),
+            await_evs_termination(Evs2, tdiff(T, t()))
+
+    after Timeout ->
+            Evs
+    end.
+
+        
+await_finish_fail(Pid, Reason, Evs, OK, Fails) ->
+    case lists:keysearch(Pid, #ev.pid, Evs) of
+        {value, #ev{name = Name}} ->
+            iprint("evaluator '~s' (~p) failed", [Name, Pid]),
+            NewEvs = lists:keydelete(Pid, #ev.pid, Evs),
+            {NewEvs, OK, [{Pid, Reason}|Fails]};
+        false ->
+            case lists:member(Pid, OK) of
+                true ->
+                    ok;
+                false ->
+                    iprint("unknown process ~p died: "
+                           "~n   ~p", [Pid, Reason])
+            end,
+            {Evs, OK, Fails}
+    end.
+
+
+
+%% ============================================================================
+
+-spec announce_start(To) -> ok when
+      To :: pid().
+
+announce_start(To) ->
+    announce(To, ?ANNOUNCEMENT_START, ?START_SLOGAN).
+
+-spec announce_start(To, Extra) -> ok when
+      To    :: pid(),
+      Extra :: term().
+
+announce_start(To, Extra) ->
+    announce(To, ?ANNOUNCEMENT_START, ?START_SLOGAN, Extra).
+
+
+%% ============================================================================
+
+-spec announce_continue(To, Slogan) -> ok when
+      To     :: pid(),
+      Slogan :: atom().
+
+announce_continue(To, Slogan) ->
+    announce_continue(To, Slogan, ?EXTRA_NOTHING).
+
+-spec announce_continue(To, Slogan, Extra) -> ok when
+      To     :: pid(),
+      Slogan :: atom(),
+      Extra  :: term().
+
+announce_continue(To, Slogan, Extra) ->
+    announce(To, ?ANNOUNCEMENT_CONTINUE, Slogan, Extra).
+
+
+%% ============================================================================
+
+-spec announce_ready(To, Slogan) -> ok when
+      To     :: pid(),
+      Slogan :: atom().
+
+announce_ready(To, Slogan) ->
+    announce_ready(To, Slogan, ?EXTRA_NOTHING).
+
+-spec announce_ready(To, Slogan, Extra) -> ok when
+      To     :: pid(),
+      Slogan :: atom(),
+      Extra  :: term().
+
+announce_ready(To, Slogan, Extra) ->
+    announce(To, ?ANNOUNCEMENT_READY, Slogan, Extra).
+
+
+%% ============================================================================
+
+-spec announce_terminate(To) -> ok when
+      To     :: pid().
+
+announce_terminate(To) ->
+    announce(To, ?ANNOUNCEMENT_TERMINATE, ?TERMINATE_SLOGAN).
+
+
+%% ============================================================================
+
+-spec announce(To, Announcement, Slogan) -> ok when
+      To           :: pid(),
+      Announcement :: atom(),
+      Slogan       :: atom().
+
+announce(To, Announcement, Slogan) ->
+    announce(To, Announcement, Slogan, ?EXTRA_NOTHING).
+
+-spec announce(To, Announcement, Slogan, Extra) -> ok when
+      To           :: pid(),
+      Announcement :: atom(),
+      Slogan       :: atom(),
+      Extra        :: term().
+
+announce(To, Announcement, Slogan, Extra) 
+  when is_pid(To) andalso 
+       is_atom(Announcement) andalso  
+       is_atom(Slogan) ->
+    %% iprint("announce -> entry with: "
+    %%        "~n   To:           ~p"
+    %%        "~n   Announcement: ~p"
+    %%        "~n   Slogan:       ~p"
+    %%        "~n   Extra:        ~p", 
+    %%        [To, Announcement, Slogan, Extra]),
+    To ! {Announcement, self(), Slogan, Extra},
+    ok.
+
+
+
+%% ============================================================================
+
+-spec await_start() -> Pid | {Pid, Extra} when
+      Pid   :: pid(),
+      Extra :: term().
+
+await_start() ->
+    await_start(any).
+
+-spec await_start(Pid) -> Pid | {Pid, Extra} when
+      Pid   :: pid(),
+      Extra :: term().
+
+await_start(P) when is_pid(P) orelse (P =:= any) ->
+    case await(P, ?START_NAME_NONE, ?ANNOUNCEMENT_START, ?START_SLOGAN, []) of
+        {ok, Any} when is_pid(P) ->
+            Any;
+        {ok, Pid} when is_pid(Pid) andalso (P =:= any) ->
+            Pid;
+        {ok, {Pid, _} = OK} when is_pid(Pid) andalso (P =:= any) ->
+            OK
+    end.
+
+
+%% ============================================================================
+
+-spec await_continue(From, Name, Slogan) -> ok | {ok, Extra} | {error, Reason} when 
+      From   :: pid(),
+      Name   :: atom(),
+      Slogan :: atom(),
+      Extra  :: term(),
+      Reason :: term().
+
+await_continue(From, Name, Slogan) ->
+    await_continue(From, Name, Slogan, []).
+
+-spec await_continue(From, Name, Slogan, OtherPids) -> 
+                         ok | {ok, Extra} | {error, Reason} when 
+      From      :: pid(),
+      Name      :: atom(),
+      Slogan    :: atom(),
+      OtherPids :: [{pid(), atom()}],
+      Extra     :: term(),
+      Reason    :: term().
+
+await_continue(From, Name, Slogan, OtherPids) 
+  when is_pid(From) andalso
+       is_atom(Name) andalso
+       is_atom(Slogan) andalso
+       is_list(OtherPids) ->
+    await(From, Name, ?ANNOUNCEMENT_CONTINUE, Slogan, OtherPids).
+
+
+
+%% ============================================================================
+
+-spec await_ready(From, Name, Slogan) -> ok | {ok, Extra} | {error, Reason} when 
+      From   :: pid(),
+      Name   :: atom(),
+      Slogan :: atom(),
+      Extra  :: term(),
+      Reason :: term().
+
+await_ready(From, Name, Slogan) ->
+    await_ready(From, Name, Slogan, []).
+
+-spec await_ready(From, Name, Slogan, OtherPids) -> 
+                         ok | {ok, Extra} | {error, Reason} when 
+      From      :: pid(),
+      Name      :: atom(),
+      Slogan    :: atom(),
+      OtherPids :: [{pid(), atom()}],
+      Extra     :: term(),
+      Reason    :: term().
+
+await_ready(From, Name, Slogan, OtherPids) 
+  when is_pid(From) andalso
+       is_atom(Name) andalso
+       is_atom(Slogan) andalso
+       is_list(OtherPids) ->
+    await(From, Name, ?ANNOUNCEMENT_READY, Slogan, OtherPids).
+
+
+
+%% ============================================================================
+
+-spec await_terminate(Pid, Name) -> ok | {error, Reason} when
+      Pid    :: pid(),
+      Name   :: atom(),
+      Reason :: term().
+
+await_terminate(Pid, Name) when is_pid(Pid) andalso is_atom(Name) ->
+    await_terminate(Pid, Name, []).
+
+-spec await_terminate(Pid, Name, OtherPids) -> ok | {error, Reason} when
+      Pid       :: pid(),
+      Name      :: atom(),
+      OtherPids :: [{pid(), atom()}],
+      Reason    :: term().
+
+await_terminate(Pid, Name, OtherPids) ->
+    await(Pid, Name, ?ANNOUNCEMENT_TERMINATE, ?TERMINATE_SLOGAN, OtherPids).
+
+
+%% ============================================================================
+
+-spec await_termination(Pid) -> ok | {error, Reason} when
+      Pid    :: pid(),
+      Reason :: term().
+
+await_termination(Pid) when is_pid(Pid) ->
+    await_termination(Pid, any).
+
+-spec await_termination(Pid, ExpReason) -> ok | {error, Reason} when
+      Pid       :: pid(),
+      ExpReason :: term(),
+      Reason    :: term().
+
+await_termination(Pid, ExpReason) ->
+    receive
+        {'DOWN', _, process, Pid, _} when (ExpReason =:= any) ->
+            ok;
+        {'DOWN', _, process, Pid, Reason} when (ExpReason =:= Reason) ->
+            ok;
+        {'DOWN', _, process, Pid, Reason} ->
+            {error, {unexpected_reason, ExpReason, Reason}}
+    end.
+
+
+%% ============================================================================
+
+%% We expect a message (announcement) from Pid, but we also watch for DOWN from 
+%% both Pid and OtherPids, in which case the test has failed!
+
+-spec await(ExpPid, Name, Announcement, Slogan, OtherPids) -> 
+                   ok | {ok, Extra} | {error, Reason} when
+      ExpPid       :: any | pid(),
+      Name         :: atom(),
+      Announcement :: atom(),
+      Slogan       :: atom(),
+      OtherPids    :: [{pid(), atom()}],
+      Extra        :: term(),
+      Reason       :: term().
+
+await(ExpPid, Name, Announcement, Slogan, OtherPids) 
+  when (is_pid(ExpPid) orelse (ExpPid =:= any)) andalso 
+       is_atom(Name) andalso 
+       is_atom(Announcement) andalso 
+       is_atom(Slogan) andalso 
+       is_list(OtherPids) ->
+    receive
+        skip ->
+            %% This means that another evaluator has issued a skip,
+            %% and we have been instructed to terminate as a result.
+            ?LIB:skip(command);
+        {Announcement, Pid, Slogan, ?EXTRA_NOTHING} when (ExpPid =:= any) ->
+            {ok, Pid};
+        {Announcement, Pid, Slogan, Extra} when (ExpPid =:= any) ->
+            {ok, {Pid, Extra}};
+        {Announcement, Pid, Slogan, ?EXTRA_NOTHING} when (Pid =:= ExpPid) ->
+            ok;
+        {Announcement, Pid, Slogan, Extra} when (Pid =:= ExpPid) ->
+            {ok, Extra};
+        {'DOWN', _, process, Pid, {skip, SkipReason}} when (Pid =:= ExpPid) ->
+            iprint("Unexpected SKIP from ~w (~p): "
+                   "~n   ~p", [Name, Pid, SkipReason]),
+            ?LIB:skip({Name, SkipReason});
+        {'DOWN', _, process, Pid, Reason} when (Pid =:= ExpPid) ->
+            eprint("Unexpected DOWN from ~w (~p): "
+                   "~n   ~p", [Name, Pid, Reason]),
+            {error, {unexpected_exit, Name, Reason}};
+        {'DOWN', _, process, OtherPid, Reason} ->
+            case check_down(OtherPid, Reason, OtherPids) of
+                ok ->
+                    iprint("DOWN from unknown process ~p: "
+                           "~n      ~p"
+                           "~n   when"
+                           "~n      OtherPids: "
+                           "~n         ~p", [OtherPid, Reason, OtherPids]),
+                    await(ExpPid, Name, Announcement, Slogan, OtherPids);
+                {error, _} = ERROR ->
+                    ERROR
+            end
+    after infinity -> % For easy debugging, just change to some valid time (5000)
+            iprint("await -> timeout for msg from ~p (~w): "
+                   "~n   Announcement: ~p"
+                   "~n   Slogan:       ~p"
+                   "~nwhen"
+                   "~n   Messages:     ~p", 
+                   [ExpPid, Name, Announcement, Slogan, pi(messages)]),
+            await(ExpPid, Name, Announcement, Slogan, OtherPids)
+    end.
+
+pi(Item) ->
+    pi(self(), Item).
+
+pi(Pid, Item) ->
+    {Item, Info} = process_info(Pid, Item),
+    Info.
+
+check_down(Pid, DownReason, Pids) ->
+    case lists:keymember(Pid, 1, Pids) of
+        {value, {_, Name}} ->
+            eprint("Unexpected DOWN from ~w (~p): "
+                   "~n   ~p", [Name, Pid, DownReason]),
+            {error, {unexpected_exit, Name, DownReason}};
+        false ->
+            ok
+    end.
+
+
+%% ============================================================================
+
+f(F, A) ->
+    lists:flatten(io_lib:format(F, A)).
+
+
+iprint(F, A) ->
+    print("", F, A).
+
+eprint(F, A) ->
+    print("<ERROR> ", F, A).
+
+print(Prefix, F, A) ->
+    %% The two prints is to get the output both in the shell (for when
+    %% "personal" testing is going on) and in the logs.
+    IDStr = 
+        case get(sname) of
+            undefined ->
+                %% This means its not an evaluator, 
+                %% or a named process. Instead its 
+                %% most likely the test case itself, 
+                %% so skip the name and the pid.
+                "";
+            SName ->
+                f("[~s][~p]", [SName, self()])
+        end,
+    ?LOGGER:format("[~s]~s ~s" ++ F,
+                   [?LIB:formated_timestamp(), IDStr, Prefix | A]).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+t() ->
+    os:timestamp().
+
+
+tdiff({A1, B1, C1} = _T1x, {A2, B2, C2} = _T2x) ->
+    T1 = A1*1000000000+B1*1000+(C1 div 1000), 
+    T2 = A2*1000000000+B2*1000+(C2 div 1000), 
+    T2 - T1.
+
diff --git a/erts/emulator/test/socket_test_evaluator.hrl b/erts/emulator/test/socket_test_evaluator.hrl
new file mode 100644
index 0000000000..5be49dc022
--- /dev/null
+++ b/erts/emulator/test/socket_test_evaluator.hrl
@@ -0,0 +1,68 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2018. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-ifndef(socket_test_evaluator).
+-define(socket_test_evaluator, true).
+
+-record(ev, {name :: string(),
+             pid  :: pid(),
+             mref :: reference()}).
+
+-define(SEV,                              socket_test_evaluator).
+
+-define(SEV_START(N, S, IS),              ?SEV:start(N, S, IS)).
+-define(SEV_AWAIT_FINISH(Evs),            ?SEV:await_finish(Evs)).
+
+-define(SEV_ANNOUNCE_START(To),           ?SEV:announce_start(To)).
+-define(SEV_ANNOUNCE_START(To, Ex),       ?SEV:announce_start(To, Ex)).
+-define(SEV_ANNOUNCE_CONTINUE(To, S),     ?SEV:announce_continue(To, S)).
+-define(SEV_ANNOUNCE_CONTINUE(To, S, Ex), ?SEV:announce_continue(To, S, Ex)).
+-define(SEV_ANNOUNCE_READY(To, S),        ?SEV:announce_ready(To, S)).
+-define(SEV_ANNOUNCE_READY(To, S, Ex),    ?SEV:announce_ready(To, S, Ex)).
+-define(SEV_ANNOUNCE_TERMINATE(To),       ?SEV:announce_terminate(To)).
+
+-define(SEV_AWAIT_START(),                ?SEV:await_start()).
+-define(SEV_AWAIT_START(P),               ?SEV:await_start(P)).
+-define(SEV_AWAIT_CONTINUE(F, N, S),      ?SEV:await_continue(F, N, S)).
+-define(SEV_AWAIT_CONTINUE(F, N, S, Ps),  ?SEV:await_continue(F, N, S, Ps)).
+-define(SEV_AWAIT_READY(F, N, S),         ?SEV:await_ready(F, N, S)).
+-define(SEV_AWAIT_READY(F, N, S, Ps),     ?SEV:await_ready(F, N, S, Ps)).
+-define(SEV_AWAIT_TERMINATE(F, N),        ?SEV:await_terminate(F, N)).
+-define(SEV_AWAIT_TERMINATE(F, N, Ps),    ?SEV:await_terminate(F, N, Ps)).
+-define(SEV_AWAIT_TERMINATION(P),         ?SEV:await_termination(P)).
+-define(SEV_AWAIT_TERMINATION(P, R),      ?SEV:await_termination(P, R)).
+
+-define(SEV_IPRINT(F, A),                 ?SEV:iprint(F, A)).
+-define(SEV_IPRINT(F),                    ?SEV_IPRINT(F, [])).
+-define(SEV_EPRINT(F, A),                 ?SEV:eprint(F, A)).
+-define(SEV_EPRINT(F),                    ?SEV_EPRINT(F, [])).
+
+-define(SEV_SLEEP(T), #{desc => "sleep",
+                        cmd  => fun(_) ->
+                                        ?SLEEP(T),
+                                        ok
+                                end}).
+-define(SEV_FINISH_NORMAL, #{desc => "finish",
+                             cmd  => fun(_) ->
+                                             {ok, normal}
+                                     end}).
+
+-endif. % -ifdef(socket_test_evaluator).
+
diff --git a/erts/emulator/test/socket_test_lib.erl b/erts/emulator/test/socket_test_lib.erl
new file mode 100644
index 0000000000..39cbf0c79f
--- /dev/null
+++ b/erts/emulator/test/socket_test_lib.erl
@@ -0,0 +1,299 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2018. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_lib).
+
+-export([
+         pi/1, pi/2, pi/3,
+
+         %% Time stuff
+         timestamp/0,
+         tdiff/2,
+         formated_timestamp/0,
+         format_timestamp/1,
+
+         %% String and format
+         f/2,
+
+         %% Generic 'has support' test function(s)
+         has_support_ipv6/0,
+
+         which_local_host_info/1,
+         which_local_addr/1,
+
+         %% Skipping
+         not_yet_implemented/0,
+         skip/1
+        ]).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+-define(FAIL(R), exit(R)).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+pi(Item) when is_atom(Item) ->
+    pi(self(), Item).
+
+pi(Pid, Item) when is_pid(Pid) andalso is_atom(Item) ->
+    {Item, Info} = process_info(Pid, Item),
+    Info;
+pi(Node, Pid) when is_pid(Pid) ->
+    rpc:call(Node, erlang, process_info, [Pid]).
+
+pi(Node, Pid, Item) when is_pid(Pid) andalso is_atom(Item) ->
+    rpc:call(Node, erlang, process_info, [Pid, Item]).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+timestamp() ->
+    os:timestamp().
+
+
+tdiff({A1, B1, C1} = _T1x, {A2, B2, C2} = _T2x) ->
+    T1 = A1*1000000000+B1*1000+(C1 div 1000), 
+    T2 = A2*1000000000+B2*1000+(C2 div 1000), 
+    T2 - T1.
+
+
+formated_timestamp() ->
+    format_timestamp(os:timestamp()).
+
+format_timestamp({_N1, _N2, _N3} = TS) ->
+    {_Date, Time}   = calendar:now_to_local_time(TS),
+    %% {YYYY,MM,DD}   = Date,
+    {Hour,Min,Sec} = Time,
+    %% FormatTS = 
+    %%     io_lib:format("~.4w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w.~w",
+    %%                   [YYYY, MM, DD, Hour, Min, Sec, N3]),  
+    FormatTS = io_lib:format("~.2.0w:~.2.0w:~.2.0w", [Hour, Min, Sec]),  
+    lists:flatten(FormatTS).
+
+   
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+f(F, A) ->
+    lists:flatten(io_lib:format(F, A)).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+has_support_ipv6() ->
+    case socket:supports(ipv6) of
+        true ->
+            ok;
+        false ->
+            skip("IPv6 Not Supported")
+    end,
+    Domain = inet6,
+    LocalAddr =
+        case which_local_addr(Domain) of
+            {ok, Addr} ->
+                Addr;
+            {error, R1} ->
+                skip(f("Local Address eval failed: ~p", [R1]))
+        end,
+    ServerSock =
+        case socket:open(Domain, dgram, udp) of
+            {ok, SS} ->
+                SS;
+            {error, R2} ->
+                skip(f("(server) socket open failed: ~p", [R2]))
+        end,
+    LocalSA = #{family => Domain, addr => LocalAddr},
+    ServerPort =
+        case socket:bind(ServerSock, LocalSA) of
+            {ok, P1} ->
+                P1;
+            {error, R3} ->
+                socket:close(ServerSock),
+                skip(f("(server) socket bind failed: ~p", [R3]))
+        end,
+    ServerSA = LocalSA#{port => ServerPort},
+    ClientSock =
+        case socket:open(Domain, dgram, udp) of
+            {ok, CS} ->
+                CS;
+            {error, R4} ->
+                skip(f("(client) socket open failed: ~p", [R4]))
+        end,
+    case socket:bind(ClientSock, LocalSA) of
+        {ok, _} ->
+            ok;
+        {error, R5} ->
+            socket:close(ServerSock),
+            socket:close(ClientSock),
+            skip(f("(client) socket bind failed: ~p", [R5]))
+    end,
+    case socket:sendto(ClientSock, <<"hejsan">>, ServerSA) of
+        ok ->
+            ok;
+        {error, R6} ->
+            socket:close(ServerSock),
+            socket:close(ClientSock),
+            skip(f("failed socket sendto test: ~p", [R6]))
+    end,
+    case socket:recvfrom(ServerSock) of
+        {ok, {_, <<"hejsan">>}} ->
+            socket:close(ServerSock),
+            socket:close(ClientSock),
+            ok;
+        {error, R7} ->
+            socket:close(ServerSock),
+            socket:close(ClientSock),
+            skip(f("failed socket recvfrom test: ~p", [R7]))
+   end.
+            
+            
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% This gets the local address (not {127, _} or {0, ...} or {16#fe80, ...})
+%% We should really implement this using the (new) net module,
+%% but until that gets the necessary functionality...
+which_local_addr(Domain) ->
+    case which_local_host_info(Domain) of
+        {ok, #{addr := Addr}} ->
+            {ok, Addr};
+        {error, _Reason} = ERROR ->
+            ERROR
+    end.
+    
+
+%% Returns the interface (name), flags and address (not 127...)
+%% of the local host.
+which_local_host_info(Domain) ->
+    case inet:getifaddrs() of
+        {ok, IFL} ->
+            which_local_host_info(Domain, IFL);
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+which_local_host_info(_Domain, []) ->
+    {error, no_address};
+which_local_host_info(Domain, [{"lo" ++ _, _}|IFL]) ->
+    which_local_host_info(Domain, IFL);
+which_local_host_info(Domain, [{"docker" ++ _, _}|IFL]) ->
+    which_local_host_info(Domain, IFL);
+which_local_host_info(Domain, [{"br-" ++ _, _}|IFL]) ->
+    which_local_host_info(Domain, IFL);
+which_local_host_info(Domain, [{Name, IFO}|IFL]) ->
+    try which_local_host_info2(Domain, IFO) of
+        Info ->
+            {ok, Info#{name => Name}}
+    catch
+        throw:_:_ ->
+            which_local_host_info(Domain, IFL)
+    end;
+which_local_host_info(Domain, [_|IFL]) ->
+    which_local_host_info(Domain, IFL).
+
+%% which_local_host_info2(Domain, IFO) ->
+%%     case lists:keysearch(flags, 1, IFO) of
+%%         {value, {flags, Flags}} ->
+%%             which_local_host_info2(Domain, IFO, Flags);
+%%         false ->
+%%             {error, no_flags}
+%%     end.
+
+
+%% which_local_host_info2(_Domain, [], _Flags) ->
+%%     {error, no_address};
+%% which_local_host_info2(inet = _Domain, [{addr, Addr}|_IFO], Flags)
+%%   when (size(Addr) =:= 4) andalso (element(1, Addr) =/= 127) ->
+%%     {ok, {Flags, Addr}};
+%% which_local_host_info2(inet6 = _Domain, [{addr, Addr}|_IFO], Flags)
+%%   when (size(Addr) =:= 8) andalso 
+%%        (element(1, Addr) =/= 0) andalso
+%%        (element(1, Addr) =/= 16#fe80) ->
+%%     {ok, {Flags, Addr}};
+%% which_local_host_info2(Domain, [_|IFO], Flags) ->
+%%     which_local_host_info2(Domain, IFO, Flags).
+
+%% foo(Info, inet = Domain, IFO) ->
+%%     foo(Info, Domain, IFO, [flags, addr, netmask, broadaddr, hwaddr]);
+%% foo(Info, inet6 = Domain, IFO) ->
+%%     foo(Info, Domain, IFO, [flags, addr, netmask, hwaddr]).
+
+which_local_host_info2(inet = _Domain, IFO) ->
+    Addr      = which_local_host_info3(addr,  IFO,
+                                       fun({A, _, _, _}) when (A =/= 127) -> true;
+                                          (_) -> false
+                                       end),
+    NetMask   = which_local_host_info3(netmask,  IFO,
+                                       fun({_, _, _, _}) -> true;
+                                          (_) -> false
+                                       end),
+    BroadAddr = which_local_host_info3(broadaddr,  IFO,
+                                       fun({_, _, _, _}) -> true;
+                                          (_) -> false
+                                       end),
+    Flags     = which_local_host_info3(flags, IFO, fun(_) -> true end),
+    #{flags     => Flags,
+      addr      => Addr,
+      broadaddr => BroadAddr,
+      netmask   => NetMask};
+which_local_host_info2(inet6 = _Domain, IFO) ->
+    Addr    = which_local_host_info3(addr,  IFO,
+                                     fun({A, _, _, _, _, _, _, _}) 
+                                           when (A =/= 0) andalso 
+                                                (A =/= 16#fe80) -> true;
+                                        (_) -> false
+                                     end),
+    NetMask = which_local_host_info3(netmask,  IFO,
+                                       fun({_, _, _, _, _, _, _, _}) -> true;
+                                          (_) -> false
+                                       end),
+    Flags   = which_local_host_info3(flags, IFO, fun(_) -> true end),
+    #{flags   => Flags,
+      addr    => Addr,
+      netmask => NetMask}.
+
+which_local_host_info3(_Key, [], _) ->
+    throw({error, no_address});
+which_local_host_info3(Key, [{Key, Val}|IFO], Check) ->
+    case Check(Val) of
+        true ->
+            Val;
+        false ->
+            which_local_host_info3(Key, IFO, Check)
+    end;
+which_local_host_info3(Key, [_|IFO], Check) ->
+    which_local_host_info3(Key, IFO, Check).
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+not_yet_implemented() ->
+    skip("not yet implemented").
+
+skip(Reason) ->
+    throw({skip, Reason}).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
diff --git a/erts/emulator/test/socket_test_logger.erl b/erts/emulator/test/socket_test_logger.erl
new file mode 100644
index 0000000000..f5d4c8c7b2
--- /dev/null
+++ b/erts/emulator/test/socket_test_logger.erl
@@ -0,0 +1,118 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_logger).
+
+-export([
+         start/0, start/1,
+         stop/0,
+         format/2
+        ]).
+
+
+-define(QUIET,  true).
+-define(LIB,    socket_test_lib).
+-define(LOGGER, ?MODULE).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+start() ->
+    start(?QUIET).
+
+start(Quiet) ->
+    case global:whereis_name(?LOGGER) of
+        Pid when is_pid(Pid) ->
+            ok;
+        undefined ->
+            Self = self(),
+            Pid = spawn(fun() -> init(Self, Quiet) end),
+            yes = global:register_name(?LOGGER, Pid),
+            ok
+    end.
+
+
+stop() ->
+    case global:whereis_name(?LOGGER) of
+        undefined ->
+            ok;
+        Pid when is_pid(Pid) ->
+            global:unregister_name(?LOGGER),
+            Pid ! {?LOGGER, '$logger', stop},
+            ok
+    end.
+
+
+format(F, []) ->
+    do_format(F);
+format(F, A) ->
+    do_format(?LIB:f(F, A)).
+
+do_format(Msg) ->
+    case global:whereis_name(?LOGGER) of
+        undefined ->
+            ok;
+        Pid when is_pid(Pid) ->
+            Pid ! {?MODULE, '$logger', {msg, Msg}},
+            ok
+    end.
+
+init(Parent, Quiet) ->
+    put(sname, "logger"),
+    print("[~s][logger] starting~n", [?LIB:formated_timestamp()]),
+    loop(#{parent => Parent, quiet => Quiet}).
+
+loop(#{parent := Parent,
+       quiet  := Quiet} = State) ->
+    receive
+        {'EXIT', Parent, _} ->
+            print("[~s][logger] parent exit~n", [?LIB:formated_timestamp()]),
+            exit(normal);
+
+        {?MODULE, '$logger', stop} ->
+            print("[~s][logger] stopping~n", [?LIB:formated_timestamp()]),
+            exit(normal);
+
+        {?MODULE, '$logger', {msg, Msg}} ->
+            print_str(Quiet, Msg),
+            loop(State)
+    end.
+
+
+print(F, A) ->
+    print_str(false, ?LIB:f(F, A)).
+
+print_str(Quiet, Str) ->
+    try
+        begin
+            if (Quiet =/= true) -> io:format(user, Str ++ "~n", []);
+               true             -> ok
+            end,
+            io:format(Str, [])
+        end
+    catch
+        _:_:_ ->
+            io:format(user,
+                      "~nFailed Format message:"
+                      "~n~p~n", [Str]),
+            io:format("~nFailed Format message:"
+                      "~n~p~n", [Str])
+    end.
+            
diff --git a/erts/preloaded/src/otp_ring0.erl b/erts/emulator/test/socket_test_ttest.hrl
index 62a60fffe2..1a004a9a7a 100644
--- a/erts/preloaded/src/otp_ring0.erl
+++ b/erts/emulator/test/socket_test_ttest.hrl
@@ -1,8 +1,8 @@
 %%
 %% %CopyrightBegin%
-%%
-%% Copyright Ericsson AB 2000-2016. All Rights Reserved.
-%%
+%% 
+%% Copyright Ericsson AB 2018-2018. All Rights Reserved.
+%% 
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
 %% You may obtain a copy of the License at
@@ -14,24 +14,19 @@
 %% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 %% See the License for the specific language governing permissions and
 %% limitations under the License.
-%%
+%% 
 %% %CopyrightEnd%
 %%
--module(otp_ring0).
 
-%% Purpose : Start up of erlang system.
+-ifndef(socket_test_ttest).
+-define(socket_test_ttest, true).
+
+-define(TTEST_TAG,          42).
+-define(TTEST_TYPE_REQUEST, 101).
+-define(TTEST_TYPE_REPLY,   102).
 
--export([start/2]).
+-define(SECS(I), timer:seconds(I)).
 
--spec start(_, term()) -> term().
-start(_Env, Argv) ->
-    run(init, boot, Argv).
+-define(SLEEP(T), receive after T -> ok end).
 
-run(M, F, A) ->
-    case erlang:function_exported(M, F, 1) of
-	false ->
-	    erlang:display({fatal,error,module,M,"does not export",F,"/1"}),
-	    halt(1);
-	true ->
-            M:F(A)
-    end.
+-endif. % -ifdef(socket_test_ttest).
diff --git a/erts/emulator/test/socket_test_ttest_client.hrl b/erts/emulator/test/socket_test_ttest_client.hrl
new file mode 100644
index 0000000000..84e736cc34
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_client.hrl
@@ -0,0 +1,141 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2018. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-ifndef(socket_test_ttest_client).
+-define(socket_test_ttest_client, true).
+
+-define(MSG_ID_DEFAULT,  2).
+-define(RUNTIME_DEFAULT, ?SECS(10)).
+-define(MAX_ID,          16#FFFFFFFF).
+
+-define(MSG_DATA1, <<"This is test data 0123456789 0123456789 0123456789">>).
+-define(MSG_DATA2, <<"This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789">>).
+-define(MSG_DATA3, <<"This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+		     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+		     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+		     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+		     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+		     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+		     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+		     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+		     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+		     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789"
+                     "This is test data 0123456789 0123456789 0123456789">>).
+
+
+-endif. % -ifdef(socket_test_ttest_client).
diff --git a/erts/emulator/test/socket_test_ttest_lib.erl b/erts/emulator/test/socket_test_ttest_lib.erl
new file mode 100644
index 0000000000..7fc13df46a
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_lib.erl
@@ -0,0 +1,127 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2018. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_ttest_lib).
+
+-compile({no_auto_import, [error/2]}).
+
+-export([
+         t/0, tdiff/2,
+         formated_timestamp/0, format_timestamp/1,
+         format_time/1,
+
+         formated_process_stats/1, formated_process_stats/2,
+
+         format/2,
+         error/1, error/2,
+         info/1, info/2
+        ]).
+
+%% ==========================================================================
+
+t() ->
+    os:timestamp().
+
+tdiff({A1, B1, C1} = _T1x, {A2, B2, C2} = _T2x) ->
+    T1 = A1*1000000000+B1*1000+(C1 div 1000), 
+    T2 = A2*1000000000+B2*1000+(C2 div 1000), 
+    T2 - T1.
+
+formated_timestamp() ->
+    format_timestamp(os:timestamp()).
+
+format_timestamp({_N1, _N2, N3} = TS) ->
+    {_Date, Time}  = calendar:now_to_local_time(TS),
+    {Hour,Min,Sec} = Time,
+    FormatTS = io_lib:format("~.2.0w:~.2.0w:~.2.0w.4~w",
+                             [Hour, Min, Sec, round(N3/1000)]),  
+    lists:flatten(FormatTS).
+
+%% Time is always in number os ms (milli seconds)
+%% At some point, we should convert this to a more readable format...
+format_time(T) when (T < 1000) ->
+    format("~w ms", [T]);
+format_time(T) ->
+    format("~w sec (~w ms)", [T div 1000, T]).
+
+
+formated_process_stats(Pid) ->
+    formated_process_stats("", Pid).
+
+formated_process_stats(Prefix, Pid) when is_list(Prefix) andalso is_pid(Pid) ->
+    try
+        begin
+            TotHeapSz = pi(Pid, total_heap_size),
+            HeapSz    = pi(Pid, heap_size),
+            StackSz   = pi(Pid, stack_size),
+            Reds      = pi(Pid, reductions),
+            GCInfo    = pi(Pid, garbage_collection),
+            MinBinVHeapSz = proplists:get_value(min_bin_vheap_size, GCInfo),
+            MinHeapSz     = proplists:get_value(min_heap_size,      GCInfo),
+            MinGCS        = proplists:get_value(minor_gcs,          GCInfo),
+            format("~n   ~sTotal Heap Size:         ~p"
+                   "~n   ~sHeap Size:               ~p"
+                   "~n   ~sStack Size:              ~p"
+                   "~n   ~sReductions:              ~p"
+                   "~n   ~s[GC] Min Bin VHeap Size: ~p"
+                   "~n   ~s[GC] Min Heap Size:      ~p"
+                   "~n   ~s[GC] Minor GCS:          ~p",
+                   [Prefix, TotHeapSz,
+                    Prefix, HeapSz,
+                    Prefix, StackSz,
+                    Prefix, Reds,
+                    Prefix, MinBinVHeapSz,
+                    Prefix, MinHeapSz,
+                    Prefix, MinGCS])
+        end
+    catch
+        _:_:_ ->
+            ""
+    end.
+
+
+pi(Pid, Item) ->
+    {Item, Info} = process_info(Pid, Item),
+    Info.
+
+
+
+%% ==========================================================================
+
+format(F, A) ->
+    lists:flatten(io_lib:format(F, A)).
+
+error(F) ->
+    error(F, []).
+
+error(F, A) ->
+    print(get(sname), "<ERROR> " ++ F, A).
+
+info(F) ->
+    info(F, []).
+
+info(F, A) ->
+    print(get(sname), "<INFO> " ++ F, A).
+
+print(undefined, F, A) ->
+    print("- ", F, A);
+print(Prefix, F, A) ->
+    io:format("[~s, ~s] " ++ F ++ "~n", [formated_timestamp(), Prefix |A]).
+
diff --git a/erts/emulator/test/socket_test_ttest_tcp_client.erl b/erts/emulator/test/socket_test_ttest_tcp_client.erl
new file mode 100644
index 0000000000..f28819ca69
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_tcp_client.erl
@@ -0,0 +1,687 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+%% ==========================================================================
+%%
+%% This is the "simple" client using gen_tcp. The client is supposed to be
+%% as simple as possible in order to incur as little overhead as possible.
+%%
+%% There are three ways to run the client: active, passive or active-once.
+%%
+%% The client is the entity that controls the test, timing and counting.
+%%
+%% ==========================================================================
+%%
+%% Before the actual test starts, the client performs a "warmup".
+%% The warmup has two functions. First, to ensure that everything is "loaded"
+%% and, second, to calculate an approximate roundtrip time, in order to
+%% "know" how many iterations we should make (to run for the expected time).
+%% This is not intended to be exact, but just to ensure that all tests take
+%% approx the same time to run.
+%%
+%% ==========================================================================
+
+-module(socket_test_ttest_tcp_client).
+
+-export([
+         %% These are for the test suite
+         start_monitor/5, start_monitor/6, start_monitor/8,
+
+         %% These are for starting in a shell when run "manually"
+         start/3, start/4, start/6, start/7,
+         stop/1
+        ]).
+
+%% Internal exports
+-export([
+         do_start/9
+        ]).
+
+-include_lib("kernel/include/inet.hrl").
+-include("socket_test_ttest.hrl").
+-include("socket_test_ttest_client.hrl").
+
+-define(RECV_TIMEOUT,              10000).
+-define(MAX_OUTSTANDING_DEFAULT_1, 100).
+-define(MAX_OUTSTANDING_DEFAULT_2, 10).
+-define(MAX_OUTSTANDING_DEFAULT_3, 3).
+
+-define(LIB,            socket_test_ttest_lib).
+-define(I(F),           ?LIB:info(F)).
+-define(I(F,A),         ?LIB:info(F, A)).
+-define(E(F,A),         ?LIB:error(F, A)).
+-define(F(F,A),         ?LIB:format(F, A)).
+-define(FORMAT_TIME(T), ?LIB:format_time(T)).
+-define(T(),            ?LIB:t()).
+-define(TDIFF(T1,T2),   ?LIB:tdiff(T1, T2)).
+
+-type active()          :: once | boolean().
+-type msg_id()          :: 1..3.
+-type max_outstanding() :: pos_integer().
+-type runtime()         :: pos_integer().
+
+
+%% ==========================================================================
+
+start_monitor(Node, Notify, Transport, ServerInfo, Active) ->
+    start_monitor(Node, Notify, Transport, ServerInfo, Active, ?MSG_ID_DEFAULT).
+
+start_monitor(Node, Notify, Transport, ServerInfo, Active, 1 = MsgID) ->
+    start_monitor(Node, Notify, Transport, ServerInfo, Active, MsgID,
+                  ?MAX_OUTSTANDING_DEFAULT_1, ?RUNTIME_DEFAULT);
+start_monitor(Node, Notify, Transport, ServerInfo, Active, 2 = MsgID) ->
+    start_monitor(Node, Notify, Transport, ServerInfo, Active, MsgID,
+                  ?MAX_OUTSTANDING_DEFAULT_2, ?RUNTIME_DEFAULT);
+start_monitor(Node, Notify, Transport, ServerInfo, Active, 3 = MsgID) ->
+    start_monitor(Node, Notify, Transport, ServerInfo, Active, MsgID,
+                  ?MAX_OUTSTANDING_DEFAULT_3, ?RUNTIME_DEFAULT).
+
+start_monitor(Node, Notify, Transport, ServerInfo, Active,
+              MsgID, MaxOutstanding, RunTime)
+  when (Node =/= node()) ->
+    Args = [false,
+	    self(), Notify,
+            Transport, ServerInfo, Active, MsgID, MaxOutstanding, RunTime],
+    case rpc:call(Node, ?MODULE, do_start, Args) of
+        {badrpc, _} = Reason ->
+            {error, Reason};
+        {ok, Pid} when is_pid(Pid) ->
+            MRef = erlang:monitor(process, Pid),
+            {ok, {Pid, MRef}};
+        {error, _} = ERROR ->
+            ERROR
+    end;
+start_monitor(_, Notify, Transport, ServerInfo, Active,
+              MsgID, MaxOutstanding, RunTime) ->
+    case do_start(false,
+		  self(), Notify,
+                  Transport, Active, ServerInfo,
+                  MsgID, MaxOutstanding, RunTime) of
+        {ok, Pid} ->
+            MRef = erlang:monitor(process, Pid),
+            {ok, {Pid, MRef}};
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+
+start(Transport, ServerInfo, Active) ->
+    start(Transport, ServerInfo, Active, ?MSG_ID_DEFAULT).
+
+start(Transport, ServerInfo, Active, 1 = MsgID) ->
+    start(false,
+	  Transport, ServerInfo, Active, MsgID,
+          ?MAX_OUTSTANDING_DEFAULT_1, ?RUNTIME_DEFAULT);
+start(Transport, ServerInfo, Active, 2 = MsgID) ->
+    start(false,
+	  Transport, ServerInfo, Active, MsgID,
+          ?MAX_OUTSTANDING_DEFAULT_2, ?RUNTIME_DEFAULT);
+start(Transport, ServerInfo, Active, 3 = MsgID) ->
+    start(false,
+	  Transport, ServerInfo, Active, MsgID,
+          ?MAX_OUTSTANDING_DEFAULT_3, ?RUNTIME_DEFAULT).
+
+start(Transport, ServerInfo, Active, MsgID, MaxOutstanding, RunTime) ->
+    start(false,
+	  Transport, ServerInfo, Active, MsgID, MaxOutstanding, RunTime).
+
+start(Quiet, Transport, ServerInfo, Active, MsgID, MaxOutstanding, RunTime) ->
+    Notify = fun(R) -> present_results(R) end,
+    do_start(Quiet,
+	     self(), Notify,
+             Transport, ServerInfo, Active, MsgID, MaxOutstanding, RunTime).
+                      
+
+-spec do_start(Quiet,
+	       Parent,
+               Notify,
+               Transport,
+               ServerInfo,
+               Active,
+               MsgID,
+               MaxOutstanding,
+               RunTime) -> {ok, Pid} | {error, Reason} when
+      Quiet          :: boolean(),
+      Parent         :: pid(),
+      Notify         :: function(),
+      Transport      :: atom() | tuple(),
+      ServerInfo     :: {inet:ip_address(), inet:port_number()} | string(),
+      Active         :: active(),
+      MsgID          :: msg_id(),
+      MaxOutstanding :: max_outstanding(),
+      RunTime        :: runtime(),
+      Pid            :: pid(),
+      Reason         :: term().
+
+do_start(Quiet,
+	 Parent, Notify,
+         Transport, ServerInfo, Active, MsgID, MaxOutstanding, RunTime)
+  when is_boolean(Quiet) andalso
+       is_pid(Parent) andalso
+       is_function(Notify) andalso
+       (is_atom(Transport) orelse is_tuple(Transport)) andalso
+       (is_boolean(Active) orelse (Active =:= once)) andalso
+       (is_tuple(ServerInfo) orelse is_list(ServerInfo)) andalso 
+       (is_integer(MsgID) andalso (MsgID >= 1) andalso (MsgID =< 3)) andalso
+       (is_integer(MaxOutstanding) andalso (MaxOutstanding > 0)) andalso
+       (is_integer(RunTime) andalso (RunTime > 0)) ->
+    Starter = self(),
+    Init = fun() -> put(sname, "client"),
+                    init(Quiet,
+			 Starter, 
+                         Parent,
+                         Notify,
+                         Transport, Active, ServerInfo,
+                         MsgID, MaxOutstanding, RunTime)
+           end,
+    {Pid, MRef} = spawn_monitor(Init),
+    receive
+        {'DOWN', MRef, process, Pid, Reason} ->
+            {error, Reason};
+        {?MODULE, Pid, ok} ->
+            erlang:demonitor(MRef),
+            {ok, Pid};
+        {?MODULE, Pid, {error, _} = ERROR} ->
+            erlang:demonitor(MRef, [flush]),
+            ERROR
+    end.
+
+
+%% We should not normally stop this (it terminates when its done).
+stop(Pid) when is_pid(Pid) ->
+    req(Pid, stop).
+
+
+%% ==========================================================================
+
+init(Quiet,
+     Starter,
+     Parent, Notify,
+     Transport, Active, ServerInfo,
+     MsgID, MaxOutstanding, RunTime) ->
+    if
+	not Quiet ->
+	    ?I("init with"
+	       "~n   Transport:            ~p"
+	       "~n   Active:               ~p"
+	       "~n   ServerInfo:           ~s"
+	       "~n   Msg ID:               ~p (=> 16 + ~w bytes)"
+	       "~n   Max Outstanding:      ~p"
+	       "~n   (Suggested) Run Time: ~p ms",
+	       [Transport, Active,
+                case ServerInfo of
+                    {Addr, Port} ->
+                        ?F("Addr: ~s, Port: ~w", [inet:ntoa(Addr), Port]);
+                    Path ->
+                        Path
+                end,
+		MsgID, size(which_msg_data(MsgID)), MaxOutstanding, RunTime]);
+	true ->
+	    ok
+    end,
+    {Mod, Connect} = process_transport(Transport),
+    case Connect(ServerInfo) of
+        {ok, Sock} ->
+            if not Quiet -> ?I("connected");
+	       true      -> ok
+	    end,
+            Starter ! {?MODULE, self(), ok},
+	    initial_activation(Mod, Sock, Active),
+            Results = loop(#{quiet           => Quiet,
+			     slogan          => run,
+			     runtime         => RunTime,
+			     start           => ?T(),
+			     parent          => Parent,
+			     mod             => Mod,
+			     sock            => Sock,
+			     active          => Active,
+			     msg_data        => which_msg_data(MsgID),
+			     outstanding     => 0,
+			     max_outstanding => MaxOutstanding,
+			     sid             => 1,
+			     rid             => 1,
+			     scnt            => 0,
+			     rcnt            => 0,
+			     bcnt            => 0,
+			     num             => undefined,
+			     acc             => <<>>}),
+            Notify(Results),
+            (catch Mod:close(Sock)),
+            exit(normal);
+        {error, Reason} ->
+            ?E("connect failed: ~p"
+	       "~n   ~p", [Reason, ServerInfo]),
+            exit({connect, Reason, ServerInfo})
+    end.
+
+process_transport(Mod) when is_atom(Mod) ->
+    %% In this case we assume it to be a plain tcp socket
+    {Mod, fun({A, P}) -> Mod:connect(A, P) end};
+process_transport({Mod, #{domain := Domain} = Opts}) ->
+    Connect =
+        case Domain of
+            local -> fun(Path)   -> Mod:connect(Path, Opts) end;
+            _     -> fun({A, P}) -> Mod:connect(A, P, Opts) end
+        end,
+    {Mod, Connect}.
+
+            
+which_msg_data(1) -> ?MSG_DATA1;
+which_msg_data(2) -> ?MSG_DATA2;
+which_msg_data(3) -> ?MSG_DATA3.
+
+
+present_results(#{status  := ok,
+		  runtime := RunTime,
+                  bcnt    := ByteCnt,
+                  cnt     := NumIterations}) ->
+    ?I("Results: "
+       "~n   Run Time:      ~s"
+       "~n   ByteCnt:       ~s"
+       "~n   NumIterations: ~s", 
+       [?FORMAT_TIME(RunTime), 
+        if ((ByteCnt =:= 0) orelse (RunTime =:= 0)) ->
+                ?F("~w, ~w", [ByteCnt, RunTime]);
+          true ->
+                ?F("~p => ~p byte / ms", [ByteCnt, ByteCnt div RunTime])
+       end,
+       if (RunTime =:= 0) ->
+               "-";
+          true ->
+               ?F("~p => ~p iterations / ms",
+                  [NumIterations, NumIterations div RunTime])
+       end]),
+    ok;
+present_results(#{status  := Failure,
+		  runtime := RunTime,
+		  sid     := SID,
+		  rid     := RID,
+                  scnt    := SCnt,
+                  rcnt    := RCnt,
+                  bcnt    := BCnt,
+		  num     := Num}) ->
+    ?I("Time Test failed: "
+       "~n   ~p"
+       "~n"
+       "~nwhen"
+       "~n"
+       "~n   Run Time:       ~s"
+       "~n   Send ID:        ~p"
+       "~n   Recv ID:        ~p"
+       "~n   Send Count:     ~p"
+       "~n   Recv Count:     ~p"
+       "~n   Byte Count:     ~p"
+       "~n   Num Iterations: ~p",
+       [Failure,
+        ?FORMAT_TIME(RunTime),
+        SID, RID, SCnt, RCnt, BCnt, Num]).
+
+
+
+loop(#{runtime := RunTime} = State) ->
+    erlang:start_timer(RunTime, self(), stop),
+    try do_loop(State)
+    catch
+        throw:Results ->
+            Results
+    end.
+
+do_loop(State) ->
+    do_loop( handle_message( msg_exchange(State) ) ).
+
+msg_exchange(#{rcnt := Num, num := Num} = State) ->
+    finish(ok, State);
+msg_exchange(#{scnt := Num, num := Num} = State) ->
+    %% We are done sending more requests - now we will just await 
+    %% the replies for the (still) outstanding replies.
+    msg_exchange( recv_reply(State) );
+msg_exchange(#{outstanding     := Outstanding,
+               max_outstanding := MaxOutstanding} = State)
+  when (Outstanding < MaxOutstanding) ->
+    msg_exchange( send_request(State) );
+msg_exchange(State) ->
+    send_request( recv_reply(State) ).
+
+
+finish(ok,
+       #{start := Start, bcnt  := BCnt, num := Num}) ->
+    Stop = ?T(),
+    throw(#{status  => ok,
+	    runtime => ?TDIFF(Start, Stop),
+            bcnt    => BCnt,
+            cnt     => Num});
+finish(Reason,
+       #{start := Start,
+	 sid  := SID, rid := RID,
+	 scnt := SCnt, rcnt := RCnt, bcnt := BCnt,
+	 num  := Num}) ->
+    Stop = ?T(),
+    throw(#{status  => Reason,
+	    runtime => ?TDIFF(Start, Stop),
+	    sid     => SID,
+	    rid     => RID,
+            scnt    => SCnt,
+            rcnt    => RCnt,
+            bcnt    => BCnt,
+            num     => Num}).
+    
+send_request(#{mod             := Mod,
+	       sock            := Sock, 
+	       sid             := ID,
+	       scnt            := Cnt,
+	       outstanding     := Outstanding,
+	       max_outstanding := MaxOutstanding,
+	       msg_data        := Data} = State)
+  when (MaxOutstanding > Outstanding) ->
+    SZ   = size(Data),
+    Req  = <<?TTEST_TAG:32,
+	     ?TTEST_TYPE_REQUEST:32,
+	     ID:32,
+	     SZ:32,
+	     Data/binary>>,
+    case Mod:send(Sock, Req) of
+        ok ->
+            State#{sid         => next_id(ID),
+		   scnt        => Cnt + 1,
+		   outstanding => Outstanding + 1};
+        {error, Reason} ->
+            ?E("Failed sending request: ~p", [Reason]),
+            exit({send, Reason})
+    end;
+send_request(State) ->
+    State.
+
+
+
+recv_reply(#{mod         := Mod,
+	     sock        := Sock, 
+             rid         := ID,
+             active      := false,
+             bcnt        := BCnt,
+             rcnt        := Cnt,
+	     outstanding := Outstanding} = State) ->
+    case recv_reply_message1(Mod, Sock, ID) of
+	{ok, MsgSz} ->
+	    State#{rid         => next_id(ID),
+		   bcnt        => BCnt + MsgSz,
+		   rcnt        => Cnt + 1,
+		   outstanding => Outstanding - 1};
+
+	{error, timeout} ->
+	    ?I("receive timeout"),
+	    State;
+
+	{error, Reason} ->
+	    finish(Reason, State)
+    end;
+recv_reply(#{mod         := Mod,
+	     sock        := Sock,
+             rid         := ID,
+             active      := Active,
+             bcnt        := BCnt,
+             scnt        := SCnt,
+             rcnt        := RCnt,
+	     outstanding := Outstanding,
+	     acc         := Acc} = State) ->
+    case recv_reply_message2(Mod, Sock, ID, Acc) of
+	{ok, {MsgSz, NewAcc}} when is_integer(MsgSz) andalso is_binary(NewAcc) ->
+	    maybe_activate(Mod, Sock, Active),
+	    State#{rid         => next_id(ID),
+		   bcnt        => BCnt + MsgSz,
+		   rcnt        => RCnt + 1,
+		   outstanding => Outstanding - 1,
+		   acc         => NewAcc};
+
+	ok ->
+	    State;
+
+	{error, stop} ->
+	    ?I("receive [~w] -> stop", [Active]),
+	    %% This will have the effect that no more requests are sent...
+	    State#{num => SCnt, stop_started => ?T()};
+
+	{error, timeout} ->
+	    ?I("receive[~w] -> timeout", [Active]),
+	    State;
+
+	{error, Reason} ->
+	    finish(Reason, State)
+    end.
+
+
+%% This function reads exactly one (reply) message. No more no less.	
+recv_reply_message1(Mod, Sock, ID) ->
+    case Mod:recv(Sock, 4*4, ?RECV_TIMEOUT) of
+        {ok, <<?TTEST_TAG:32,
+               ?TTEST_TYPE_REPLY:32,
+               ID:32,
+               SZ:32>> = Hdr} ->
+            %% Receive the ping-pong reply boby
+            case Mod:recv(Sock, SZ, ?RECV_TIMEOUT) of
+                {ok, Data} when (size(Data) =:= SZ) ->
+		    {ok, size(Hdr) + size(Data)};
+                {error, Reason2} ->
+		    ?E("Failed reading body: "
+                       "~n   ~p: ~p", [Reason2]),
+                    {error, {recv_body, Reason2}}
+            end;
+
+        {ok, <<BadTag:32,
+               BadType:32,
+               BadID:32,
+               BadSZ:32>>} ->
+            {error, {invalid_hdr, 
+		     {?TTEST_TAG,        BadTag},
+		     {?TTEST_TYPE_REPLY, BadType},
+		     {ID,                BadID},
+		     BadSZ}};
+        {ok, _InvHdr} ->
+            {error, invalid_hdr};
+
+        {error, Reason1} ->
+	    ?E("Feiled reading header: "
+	      "~n   ~p", [Reason1]),
+            {error, {recv_hdr, Reason1}}
+    end.
+
+
+%% This function first attempts to process the data we have already
+%% accumulated. If that is not enough for a (complete) reply, it
+%% will attempt to receive more.
+recv_reply_message2(Mod, Sock, ID, Acc) ->
+    case process_acc_data(ID, Acc) of
+	ok ->
+	    %% No or insufficient data, so get more
+	    recv_reply_message3(Mod, Sock, ID, Acc);
+
+	{ok, _} = OK -> % We already had a reply accumulated - no need to read more
+	    OK;
+
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+%% This function receives a "chunk" of data, then it tries to extract
+%% one (reply) message from the accumulated and new data (combined).
+recv_reply_message3(_Mod, Sock, ID, Acc) ->
+    receive
+	{timeout, _TRef, stop} ->
+	    {error, stop};
+
+        {TagClosed, Sock} when (TagClosed =:= tcp_closed) orelse
+			       (TagClosed =:= socket_closed) ->
+            {error, closed};
+
+        {TagErr, Sock, Reason} when (TagErr =:= tcp_error) orelse
+				    (TagErr =:= socket_error) ->
+            {error, Reason};
+
+        {Tag, Sock, Msg} when (Tag =:= tcp) orelse
+			      (Tag =:= socket) ->
+            process_acc_data(ID, <<Acc/binary, Msg/binary>>)
+        
+    after ?RECV_TIMEOUT ->
+            ?I("timeout when"
+               "~n   ID:        ~p"
+               "~n   size(Acc): ~p",
+               [ID, size(Acc)]),
+            %% {error, timeout}
+            recv_reply_message3(_Mod, Sock, ID, Acc)
+    end.
+
+
+process_acc_data(ID, <<?TTEST_TAG:32,
+		       ?TTEST_TYPE_REPLY:32,
+		       ID:32,
+		       SZ:32,
+		       Data/binary>>) when (SZ =< size(Data)) ->
+    <<_Body:SZ/binary, Rest/binary>> = Data,
+    {ok, {4*4+SZ, Rest}};
+process_acc_data(ID, <<BadTag:32,
+		       BadType:32,
+		       BadID:32,
+		       BadSZ:32,
+		       _Data/binary>>) 
+  when ((BadTag  =/= ?TTEST_TAG) orelse
+	(BadType =/= ?TTEST_TYPE_REPLY) orelse
+	(BadID   =/= ID)) ->
+    {error, {invalid_hdr, 
+	     {?TTEST_TAG,        BadTag},
+	     {?TTEST_TYPE_REPLY, BadType},
+	     {ID,                BadID},
+	     BadSZ}};
+%% Not enough for an entire (reply) message
+process_acc_data(_ID, _Data) ->
+    ok.
+
+    
+handle_message(#{quiet  := Quiet,
+		 parent := Parent, sock := Sock, scnt := SCnt} = State) ->
+    receive
+	{timeout, _TRef, stop} ->
+	    if not Quiet -> ?I("STOP");
+	       true      -> ok
+	    end,
+	    %% This will have the effect that no more requests are sent...
+	    State#{num => SCnt, stop_started => ?T()};
+
+        {?MODULE, Ref, Parent, stop} ->
+            %% This *aborts* the test
+            reply(Parent, Ref, ok),
+            exit(normal);
+	
+	%% Only when active
+        {TagClosed, Sock, Reason} when (TagClosed =:= tcp_closed) orelse
+				       (TagClosed =:= socket_closed) ->
+            %% We should never get this (unless the server crashed)
+            exit({closed, Reason});
+
+	%% Only when active
+        {TagErr, Sock, Reason} when (TagErr =:= tcp_error) orelse
+				    (TagErr =:= socket_error) ->
+            exit({error, Reason})
+            
+    after 0 ->
+            State
+    end.
+        
+
+initial_activation(_Mod, _Sock, false = _Active) ->
+    ok;
+initial_activation(Mod, Sock, Active) ->
+    Mod:active(Sock, Active).
+
+
+maybe_activate(Mod, Sock, once = Active) ->
+    Mod:active(Sock, Active);
+maybe_activate(_, _, _) ->
+    ok.
+                  
+
+%% ==========================================================================
+
+req(Pid, Req) ->
+    Ref = make_ref(),
+    Pid ! {?MODULE, Ref, Pid, Req},
+    receive
+        {'EXIT', Pid, Reason} ->
+            {error, {exit, Reason}};
+        {?MODULE, Ref, Reply} ->
+            Reply
+    end.
+
+reply(Pid, Ref, Reply) ->
+    Pid ! {?MODULE, Ref, Reply}.
+
+
+%% ==========================================================================
+
+next_id(ID) when (ID < ?MAX_ID) ->
+    ID + 1;
+next_id(_) ->
+    1.
+
+
+%% ==========================================================================
+
+%% t() ->
+%%     os:timestamp().
+
+%% tdiff({A1, B1, C1} = _T1x, {A2, B2, C2} = _T2x) ->
+%%     T1 = A1*1000000000+B1*1000+(C1 div 1000), 
+%%     T2 = A2*1000000000+B2*1000+(C2 div 1000), 
+%%     T2 - T1.
+
+%% formated_timestamp() ->
+%%     format_timestamp(os:timestamp()).
+
+%% format_timestamp({_N1, _N2, N3} = TS) ->
+%%     {_Date, Time}  = calendar:now_to_local_time(TS),
+%%     {Hour,Min,Sec} = Time,
+%%     FormatTS = io_lib:format("~.2.0w:~.2.0w:~.2.0w.4~w",
+%%                              [Hour, Min, Sec, round(N3/1000)]),  
+%%     lists:flatten(FormatTS).
+
+%% %% Time is always in number os ms (milli seconds)
+%% format_time(T) ->
+%%     f("~p", [T]).
+
+
+%% ==========================================================================
+
+%% f(F, A) ->
+%%     lists:flatten(io_lib:format(F, A)).
+
+%% %% e(F) ->
+%% %%     i("<ERROR> " ++ F).
+
+%% e(F, A) ->
+%%     p(get(sname), "<ERROR> " ++ F, A).
+
+%% i(F) ->
+%%     i(F, []).
+
+%% i(F, A) ->
+%%     p(get(sname), "<INFO> " ++ F, A).
+
+%% p(undefined, F, A) ->
+%%     p("- ", F, A);
+%% p(Prefix, F, A) ->
+%%     io:format("[~s, ~s] " ++ F ++ "~n", [formated_timestamp(), Prefix |A]).
diff --git a/erts/emulator/test/socket_test_ttest_tcp_client_gen.erl b/erts/emulator/test/socket_test_ttest_tcp_client_gen.erl
new file mode 100644
index 0000000000..65a3a94d38
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_tcp_client_gen.erl
@@ -0,0 +1,49 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_ttest_tcp_client_gen).
+
+-export([
+         start/2, start/3, start/5, start/6,
+         stop/1
+        ]).
+
+-define(TRANSPORT_MOD, socket_test_ttest_tcp_gen).
+
+start(ServerInfo, Active) ->
+    socket_test_ttest_tcp_client:start(?TRANSPORT_MOD, ServerInfo, Active).
+
+start(ServerInfo, Active, MsgID) ->
+    socket_test_ttest_tcp_client:start(?TRANSPORT_MOD, ServerInfo, Active, MsgID).
+
+start(ServerInfo, Active, MsgID, MaxOutstanding, RunTime) ->
+    socket_test_ttest_tcp_client:start(false,
+				       ?TRANSPORT_MOD,
+                                       ServerInfo, Active,
+                                       MsgID, MaxOutstanding, RunTime).
+
+start(Quiet, ServerInfo, Active, MsgID, MaxOutstanding, RunTime) ->
+    socket_test_ttest_tcp_client:start(Quiet,
+				       ?TRANSPORT_MOD,
+                                       ServerInfo, Active,
+                                       MsgID, MaxOutstanding, RunTime).
+
+stop(Pid) ->
+    socket_test_ttest_tcp_client:stop(Pid).
diff --git a/erts/emulator/test/socket_test_ttest_tcp_client_socket.erl b/erts/emulator/test/socket_test_ttest_tcp_client_socket.erl
new file mode 100644
index 0000000000..2fb1242028
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_tcp_client_socket.erl
@@ -0,0 +1,116 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_ttest_tcp_client_socket).
+
+-export([
+         start/4, start/5, start/7, start/8,
+         stop/1
+        ]).
+
+-define(TRANSPORT_MOD, socket_test_ttest_tcp_socket).
+-define(MOD(D, A, M),  {?TRANSPORT_MOD, #{domain => D,
+                                          async  => A,
+                                          method => M}}).
+
+start(Method, Async, Active, ServerInfo)
+  when is_list(ServerInfo) ->
+    Domain = local,
+    socket_test_ttest_tcp_client:start_monitor(?MOD(Domain, Async, Method),
+                                               ServerInfo, Active);
+start(Method, Async, Active, ServerInfo = {Addr, _})
+  when is_tuple(Addr) andalso (size(Addr) =:= 4) ->
+    Domain = inet,
+    socket_test_ttest_tcp_client:start_monitor(?MOD(Domain, Async, Method),
+                                               ServerInfo, Active);
+start(Method, Async, Active, ServerInfo = {Addr, _})
+  when is_tuple(Addr) andalso (size(Addr) =:= 8) ->
+    Domain = inet6,
+    socket_test_ttest_tcp_client:start_monitor(?MOD(Domain, Async, Method),
+                                               ServerInfo, Active).
+
+start(Method, Async, Active, ServerInfo, MsgID)
+  when is_list(ServerInfo) ->
+    %% This is just a simplification
+    Domain = local,
+    socket_test_ttest_tcp_client:start(?MOD(Domain, Async, Method),
+                                       ServerInfo, Active, MsgID);
+start(Method, Async, Active, ServerInfo = {Addr, _}, MsgID)
+  when is_tuple(Addr) andalso (size(Addr) =:= 4) ->
+    %% This is just a simplification
+    Domain = inet,
+    socket_test_ttest_tcp_client:start(?MOD(Domain, Async, Method),
+                                       Active, ServerInfo, MsgID);
+start(Method, Async, Active, ServerInfo = {Addr, _}, MsgID)
+  when is_tuple(Addr) andalso (size(Addr) =:= 8) ->
+    Domain = inet6,
+    socket_test_ttest_tcp_client:start(?MOD(Domain, Async, Method),
+                                       ServerInfo, Active, MsgID).
+
+start(Method, Async, Active, ServerInfo, MsgID, MaxOutstanding, RunTime)
+  when is_list(ServerInfo) ->
+    Domain = local,
+    socket_test_ttest_tcp_client:start(false,
+				       ?MOD(Domain, Async, Method),
+                                       ServerInfo, Active,
+                                       MsgID, MaxOutstanding, RunTime);
+start(Method, Async, Active, ServerInfo = {Addr, _},
+      MsgID, MaxOutstanding, RunTime)
+  when is_tuple(Addr) andalso (size(Addr) =:= 4) ->
+    Domain = inet,
+    socket_test_ttest_tcp_client:start(false,
+				       ?MOD(Domain, Async, Method),
+                                       ServerInfo, Active,
+                                       MsgID, MaxOutstanding, RunTime);
+start(Method, Async, Active, ServerInfo = {Addr, _},
+      MsgID, MaxOutstanding, RunTime)
+  when is_tuple(Addr) andalso (size(Addr) =:= 8) ->
+    Domain = inet6,
+    socket_test_ttest_tcp_client:start(false,
+				       ?MOD(Domain, Async, Method),
+                                       ServerInfo, Active,
+                                       MsgID, MaxOutstanding, RunTime).
+
+start(Quiet, Async, Active, Method, ServerInfo, MsgID, MaxOutstanding, RunTime)
+  when is_list(ServerInfo) ->
+    Domain = local,
+    socket_test_ttest_tcp_client:start(Quiet,
+				       ?MOD(Domain, Async, Method),
+                                       ServerInfo, Active,
+                                       MsgID, MaxOutstanding, RunTime);
+start(Quiet, Async, Active, Method, ServerInfo = {Addr, _},
+      MsgID, MaxOutstanding, RunTime)
+  when is_tuple(Addr) andalso (size(Addr) =:= 4) ->
+    Domain = inet,
+    socket_test_ttest_tcp_client:start(Quiet,
+				       ?MOD(Domain, Async, Method),
+                                       ServerInfo, Active,
+                                       MsgID, MaxOutstanding, RunTime);
+start(Quiet, Async, Active, Method, ServerInfo = {Addr, _}, 
+      MsgID, MaxOutstanding, RunTime)
+  when is_tuple(Addr) andalso (size(Addr) =:= 8) ->
+    Domain = inet6,
+    socket_test_ttest_tcp_client:start(Quiet,
+				       ?MOD(Domain, Async, Method),
+                                       ServerInfo, Active,
+                                       MsgID, MaxOutstanding, RunTime).
+
+stop(Pid) ->
+    socket_test_ttest_client:stop(Pid).
diff --git a/erts/emulator/test/socket_test_ttest_tcp_gen.erl b/erts/emulator/test/socket_test_ttest_tcp_gen.erl
new file mode 100644
index 0000000000..e59bd881e7
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_tcp_gen.erl
@@ -0,0 +1,137 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_ttest_tcp_gen).
+
+-export([
+	 accept/1, accept/2,
+	 active/2,
+	 close/1,
+	 connect/2, connect/3,
+	 controlling_process/2,
+	 listen/0, listen/1, listen/2,
+	 peername/1,
+	 port/1,
+	 recv/2, recv/3,
+	 send/2,
+	 shutdown/2,
+	 sockname/1
+	]).
+
+
+-define(LIB, socket_test_lib).
+
+%% ==========================================================================
+
+accept(Sock) ->
+    case gen_tcp:accept(Sock) of
+	{ok, NewSock} ->
+	    {ok, NewSock};
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+accept(Sock, Timeout) ->
+    case gen_tcp:accept(Sock, Timeout) of
+	{ok, NewSock} ->
+	    {ok, NewSock};
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+
+active(Sock, NewActive) 
+  when (is_boolean(NewActive) orelse (NewActive =:= once)) ->
+    inet:setopts(Sock, [{active, NewActive}]).
+
+
+close(Sock) ->
+    gen_tcp:close(Sock).
+
+
+connect(Addr, Port) ->
+    Opts = [binary, {packet, raw}, {active, false}, {buffer, 32*1024}], 
+    do_connect(Addr, Port, Opts).
+
+connect(Addr, Port, #{domain := Domain}) ->
+    Opts = [Domain, binary, {packet, raw}, {active, false}, {buffer, 32*1024}], 
+    do_connect(Addr, Port, Opts).
+
+do_connect(Addr, Port, Opts) ->
+    case gen_tcp:connect(Addr, Port, Opts) of
+	{ok, Sock} ->
+	    {ok, Sock};
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+controlling_process(Sock, NewPid) ->
+    gen_tcp:controlling_process(Sock, NewPid).
+
+
+%% Create a listen socket
+listen() ->
+    listen(0).
+
+listen(Port) ->
+    listen(Port, #{domain => inet}).
+
+listen(Port, #{domain := Domain}) when is_integer(Port) andalso (Port >= 0) ->
+    case ?LIB:which_local_host_info(Domain) of
+	{ok, {_, _, Addr}} ->
+	    Opts = [Domain,
+		    binary, {ip, Addr}, {packet, raw}, {active, false},
+		    {buffer, 32*1024}],
+	    gen_tcp:listen(Port, Opts);
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+
+peername(Sock) ->
+    inet:peername(Sock).
+
+
+port(Sock) ->
+    inet:port(Sock).
+
+
+recv(Sock, Length) ->
+    gen_tcp:recv(Sock, Length).
+recv(Sock, Length, Timeout) ->
+    gen_tcp:recv(Sock, Length, Timeout).
+
+
+send(Sock, Data) ->
+    gen_tcp:send(Sock, Data).
+
+
+shutdown(Sock, How) ->
+    gen_tcp:shutdown(Sock, How).
+
+
+sockname(Sock) ->
+    inet:sockname(Sock).
+
+
+%% ==========================================================================
+
+
+			   
diff --git a/erts/emulator/test/socket_test_ttest_tcp_server.erl b/erts/emulator/test/socket_test_ttest_tcp_server.erl
new file mode 100644
index 0000000000..2394dc7924
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_tcp_server.erl
@@ -0,0 +1,684 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+%% ==========================================================================
+%%
+%% This is the "simple" server using gen_tcp. The server is supposed to be
+%% as simple as possible in order to incur as little overhead as possible.
+%%
+%% There are three ways to run the server: active, passive or active-once.
+%%
+%% The server does only two things; accept connnections and then reply
+%% to requests (actually the handler(s) does that). No timing or counting.
+%% That is all done by the clients.
+%%
+%% ==========================================================================
+
+-module(socket_test_ttest_tcp_server).
+
+-export([
+         %% This are for the test suite
+         start_monitor/3,
+
+         %% This are for starting in a shell when run "manually"
+         start/2,
+
+         stop/1
+        ]).
+
+%% Internal exports
+-export([
+         do_start/3
+        ]).
+
+-include_lib("kernel/include/inet.hrl").
+-include("socket_test_ttest.hrl").
+
+-define(ACC_TIMEOUT,  5000).
+-define(RECV_TIMEOUT, 5000).
+
+-define(LIB,            socket_test_ttest_lib).
+-define(I(F),           ?LIB:info(F)).
+-define(I(F,A),         ?LIB:info(F, A)).
+-define(E(F,A),         ?LIB:error(F, A)).
+-define(F(F,A),         ?LIB:format(F, A)).
+-define(FORMAT_TIME(T), ?LIB:format_time(T)).
+-define(T(),            ?LIB:t()).
+-define(TDIFF(T1,T2),   ?LIB:tdiff(T1, T2)).
+
+
+%% ==========================================================================
+
+start_monitor(Node, Transport, Active) when (Node =/= node()) ->
+    case rpc:call(Node, ?MODULE, do_start, [self(), Transport, Active]) of
+        {badrpc, _} = Reason ->
+            {error, Reason};
+        {ok, {Pid, AddrPort}} ->
+            MRef = erlang:monitor(process, Pid),
+            {ok, {{Pid, MRef}, AddrPort}};
+        {error, _} = ERROR ->
+            ERROR
+    end;
+start_monitor(_, Transport, Active) ->
+    case do_start(self(), Transport, Active) of
+        {ok, {Pid, AddrPort}} ->
+            MRef = erlang:monitor(process, Pid),
+            {ok, {{Pid, MRef}, AddrPort}};
+        {error, _} = ERROR ->
+            ERROR
+    end.
+            
+
+
+start(Transport, Active) ->
+    do_start(self(), Transport, Active).
+
+%% Note that the Async option is actually only "used" for the
+%% socket transport module (it details how to implement the
+%% active feature).
+do_start(Parent, Transport, Active)
+  when is_pid(Parent) andalso
+       (is_atom(Transport) orelse is_tuple(Transport)) andalso
+       (is_boolean(Active) orelse (Active =:= once)) ->
+    Starter    = self(),
+    ServerInit = fun() -> 
+                         put(sname, "server"),
+                         server_init(Starter, Parent, Transport, Active)
+                 end,
+    {Pid, MRef} = spawn_monitor(ServerInit),
+    receive
+        {'DOWN', MRef, process, Pid, Reason} ->
+            {error, Reason};
+        {?MODULE, Pid, {ok, AddrPort}} ->
+            erlang:demonitor(MRef),
+            {ok, {Pid, AddrPort}};
+        {?MODULE, Pid, {error, _} = ERROR} ->
+            erlang:demonitor(MRef, [flush]),
+            ERROR
+    end.
+    
+
+stop(Pid) when is_pid(Pid) ->
+    req(Pid, stop).
+
+
+%% ==========================================================================
+
+server_init(Starter, Parent, Transport, Active) ->
+    ?I("init with"
+       "~n   Transport: ~p"
+       "~n   Active:    ~p", [Transport, Active]),
+    {Mod, Listen, StatsInterval} = process_transport(Transport, Active),
+    case Listen(0) of
+        {ok, LSock} ->
+            case Mod:port(LSock) of
+                {ok, PortOrPath} ->
+                    Result =
+                        if
+                            is_integer(PortOrPath) ->
+                                %% This is just for convenience
+                                case Mod:sockname(LSock) of
+				    {ok, {Addr, _}} ->
+					?I("listening on:"
+					   "~n   Addr: ~p (~s)"
+					   "~n   Port: ~w"
+					   "~n", [Addr,
+						  inet:ntoa(Addr),
+						  PortOrPath]),
+					{Addr, PortOrPath};
+				    {error, SNReason} ->
+					exit({sockname, SNReason})
+				end;
+                            is_list(PortOrPath) ->
+                                ?I("listening on:"
+                                   "~n   Path: ~s"
+                                   "~n", [PortOrPath]),
+                                PortOrPath
+                        end,
+                    Starter ! {?MODULE, self(), {ok, Result}},
+                    server_loop(#{parent         => Parent,
+				  mod            => Mod,
+                                  active         => Active,
+                                  lsock          => LSock,
+                                  port_or_path   => PortOrPath,
+                                  handlers       => [],
+                                  stats_interval => StatsInterval,
+				  %% Accumulation
+				  runtime  => 0,
+				  mcnt     => 0,
+				  bcnt     => 0,
+				  hcnt     => 0
+				 });
+                {error, PReason} ->
+                    (catch Mod:close(LSock)),
+                    exit({port, PReason})
+            end;
+        {error, LReason} ->
+            exit({listen, LReason})
+    end.
+
+process_transport(Mod, _) when is_atom(Mod) ->
+    {Mod, fun(Port) -> Mod:listen(Port) end, infinity};
+process_transport({Mod, #{stats_interval := T} = Opts}, Active)
+  when (Active =/= false) ->
+    {Mod, fun(Port) -> Mod:listen(Port, Opts#{stats_to => self()}) end, T};
+process_transport({Mod, #{stats_interval := T} = Opts}, _Active) ->
+    {Mod, fun(Port) -> Mod:listen(Port, Opts) end, T};
+process_transport({Mod, Opts}, _Active) ->
+    {Mod, fun(Port) -> Mod:listen(Port, Opts) end, infinity}.
+
+
+
+server_loop(State) ->
+    server_loop( server_handle_message( server_accept(State, ?ACC_TIMEOUT), 0) ).
+
+server_accept(#{mod := Mod, lsock := LSock} = State, Timeout) ->
+    case Mod:accept(LSock, Timeout) of
+        {ok, Sock} ->
+            server_handle_accepted(State, Sock);
+        {error, timeout} when (Timeout =/= nowait) ->
+            State;
+        {error, AReason} ->
+	    (catch Mod:close(LSock)),
+            exit({accept, AReason})
+    end.
+
+%% server_accept(#{mod   := Mod,
+%%                 lsock := LSock} = State) ->
+%%     case Mod:accept(LSock, ?ACC_TIMEOUT) of
+%%         {ok, Sock} ->
+%%             server_handle_accepted(State, Sock);
+%%         {error, timeout} ->
+%%             State;
+%%         {error, AReason} ->
+%% 	    (catch Mod:close(LSock)),
+%%             exit({accept, AReason})
+%%     end.
+
+server_handle_accepted(#{mod      := Mod,
+                         lsock    := LSock,
+                         active   := Active,
+                         handlers := Handlers} = State,
+                      Sock) ->
+    ?I("accepted connection from ~s", 
+       [case Mod:peername(Sock) of
+            {ok, Peer} ->
+                format_peername(Peer);
+            {error, _} ->
+                "-"
+        end]),
+    {Pid, _} = handler_start(),
+    ?I("handler ~p started -> try transfer socket control", [Pid]),
+    case Mod:controlling_process(Sock, Pid) of
+        ok ->
+            maybe_start_stats_timer(State, Pid),
+            ?I("server-accept: handler ~p started", [Pid]),
+            handler_continue(Pid, Mod, Sock, Active),
+            Handlers2 = [Pid | Handlers],
+            State#{handlers => Handlers2};
+        {error, CPReason} ->
+            (catch Mod:close(Sock)),
+            (catch Mod:close(LSock)),
+            exit({controlling_process, CPReason})
+    end.
+    
+
+format_peername({Addr, Port}) ->
+    case inet:gethostbyaddr(Addr) of
+        {ok, #hostent{h_name = N}} ->
+            ?F("~s (~s:~w)", [N, inet:ntoa(Addr), Port]);
+        {error, _} ->
+            ?F("~p, ~p", [Addr, Port])
+    end;
+format_peername(Path) when is_list(Path) ->
+    Path.
+
+maybe_start_stats_timer(#{active := Active, stats_interval := Time}, Handler)
+  when (Active =/= false) andalso (is_integer(Time) andalso (Time > 0)) ->
+    start_stats_timer(Time, "handler", Handler);
+maybe_start_stats_timer(_, _) ->
+    ok.
+
+start_stats_timer(Time, ProcStr, Pid) ->
+    erlang:start_timer(Time, self(), {stats, Time, ProcStr, Pid}).
+
+server_handle_message(#{mod      := Mod,
+                        lsock    := LSock,
+                        parent   := Parent,
+                        handlers := H} = State, Timeout) ->
+    receive
+        {timeout, _TRef, {stats, Interval, ProcStr, Pid}} ->
+            case server_handle_stats(ProcStr, Pid) of
+                ok ->
+                    start_stats_timer(Interval, ProcStr, Pid);
+                skip ->
+                    ok
+            end,
+            State;
+
+        {?MODULE, Ref, Parent, stop} ->
+            reply(Parent, Ref, ok),
+            lists:foreach(fun(P) -> handler_stop(P) end, H),
+            (catch Mod:close(LSock)),
+            exit(normal);
+
+        {'DOWN', _MRef, process, Pid, Reason} -> 
+	    server_handle_down(Pid, Reason, State)
+            
+    after Timeout ->
+            State
+    end.
+
+server_handle_stats(ProcStr, Pid) ->
+    case ?LIB:formated_process_stats(Pid) of
+        "" ->
+            skip;
+        FormatedStats ->
+            ?I("Statistics for ~s ~p:~s", [ProcStr, Pid, FormatedStats]),
+            ok
+    end.
+
+
+server_handle_down(Pid, Reason, #{handlers := Handlers} = State) ->
+    case lists:delete(Pid, Handlers) of
+        Handlers ->
+            ?I("unknown process ~p died", [Pid]),                    
+            State;
+        Handlers2 ->
+            server_handle_handler_down(Pid, Reason, State#{handlers => Handlers2})
+    end.
+
+
+server_handle_handler_down(Pid,
+			   {done, RunTime, MCnt, BCnt},
+			   #{runtime := AccRunTime,
+			     mcnt    := AccMCnt,
+			     bcnt    := AccBCnt,
+			     hcnt    := AccHCnt} = State) ->
+    AccRunTime2 = AccRunTime + RunTime,
+    AccMCnt2    = AccMCnt + MCnt,
+    AccBCnt2    = AccBCnt + BCnt,
+    AccHCnt2    = AccHCnt + 1,
+    MsgCount2Str =
+        fun(RT, ART, MC, AMC) when (RT > 0) ->
+                ?F("~w => ~w (~w) msgs / ms", [MC, MC div RT, AMC div ART]);
+           (_, _, MC, AMC) ->
+                ?F("~w (~w)", [MC, AMC])
+        end,
+    ByteCount2Str =
+        fun(RT, ART, BC, ABC) when (RT > 0) ->
+                ?F("~w => ~w (~w) bytes / ms", [BC, BC div RT, ABC div ART]);
+           (_, _, BC, ABC) ->
+                ?F("~w", [BC, ABC])
+        end,
+    ?I("handler ~p (~w) done: "
+       "~n   Run Time:      ~s"
+       "~n   Message Count: ~s"
+       "~n   Byte Count:    ~s",
+       [Pid, AccHCnt2,
+        ?FORMAT_TIME(RunTime),
+        MsgCount2Str(RunTime, AccRunTime2, MCnt, AccMCnt2),
+        ByteCount2Str(RunTime, AccRunTime2, BCnt, AccBCnt2)]),
+    State#{runtime => AccRunTime2,
+	   mcnt    => AccMCnt2,
+	   bcnt    => AccBCnt2,
+	   hcnt    => AccHCnt2};
+server_handle_handler_down(Pid, Reason, State) ->
+    ?I("handler ~p terminated: "
+       "~n   ~p", [Pid, Reason]),
+    State.
+
+
+
+%% ==========================================================================
+
+handler_start() ->
+    Self         = self(),
+    HandlerInit = fun() -> put(sname, "handler"), handler_init(Self) end,
+    spawn_monitor(HandlerInit).
+
+handler_continue(Pid, Mod, Sock, Active) ->
+    req(Pid, {continue, Mod, Sock, Active}).
+
+handler_stop(Pid) ->
+    req(Pid, stop).
+
+handler_init(Parent) ->
+    ?I("starting"),
+    receive
+	{?MODULE, Ref, Parent, {continue, Mod, Sock, Active}} ->
+	    ?I("received continue"),
+	    reply(Parent, Ref, ok),
+	    handler_initial_activation(Mod, Sock, Active),
+	    handler_loop(#{parent      => Parent,
+			   mod         => Mod,
+			   sock        => Sock,
+			   active      => Active,
+			   start       => ?T(),
+			   mcnt        => 0,
+			   bcnt        => 0,
+			   last_reply  => none,
+			   acc         => <<>>})
+
+    after 5000 ->
+	    ?I("timeout when message queue: "
+               "~n   ~p"
+               "~nwhen"
+               "~n   Parent: ~p", [process_info(self(), messages), Parent]),
+	    handler_init(Parent)
+    end.
+
+handler_loop(State) ->
+    handler_loop( handler_handle_message( handler_recv_message(State) ) ).
+
+%% When passive, we read *one* request and then attempt to reply to it.
+handler_recv_message(#{mod        := Mod,
+		       sock       := Sock,
+                       active     := false,
+                       mcnt       := MCnt,
+                       bcnt       := BCnt,
+                       last_reply := LID} = State) ->
+    case handler_recv_message2(Mod, Sock) of
+        {ok, {MsgSz, ID, Body}} ->
+            handler_send_reply(Mod, Sock, ID, Body),
+            State#{mcnt       => MCnt + 1,
+                   bcnt       => BCnt + MsgSz,
+		   last_reply => ID};
+        {error, closed} ->
+            handler_done(State);
+        {error, timeout} ->
+	    ?I("timeout when: "
+               "~n   MCnt: ~p"
+               "~n   BCnt: ~p"
+               "~n   LID:  ~p", [MCnt, BCnt, LID]),
+            State
+    end;
+
+
+%% When "active" (once or true), we receive one data "message", which may 
+%% contain any number of requests or only part of a request. Then we 
+%% process this data together with whatever we had "accumulated" from 
+%% prevous messages. Each request will be extracted and replied to. If
+%% there is some data left, not enough for a complete request, we store
+%% this in 'acc' (accumulate it).
+handler_recv_message(#{mod        := Mod,
+		       sock       := Sock,
+                       active     := Active,
+                       mcnt       := MCnt,
+                       bcnt       := BCnt,
+                       last_reply := LID,
+                       acc        := Acc} = State) ->
+    case handler_recv_message3(Mod, Sock, Acc, LID) of
+	{ok, {MCnt2, BCnt2, LID2}, NewAcc} ->
+	    handler_maybe_activate(Mod, Sock, Active),
+	    State#{mcnt       => MCnt + MCnt2,
+		   bcnt       => BCnt + BCnt2,
+		   last_reply => LID2,
+		   acc        => NewAcc};
+
+        {error, closed} ->
+            if
+                (size(Acc) =:= 0) ->
+                    handler_done(State);
+                true ->
+                    ?E("client done with partial message: "
+                       "~n   Last Reply Sent: ~w"
+                       "~n   Message Count:   ~w"
+                       "~n   Byte    Count:   ~w"
+                       "~n   Partial Message: ~w bytes",
+                       [LID, MCnt, BCnt, size(Acc)]),
+                    exit({closed_with_partial_message, LID})
+            end;
+
+        {error, timeout} ->
+	    ?I("timeout when: "
+               "~n   MCnt:      ~p"
+               "~n   BCnt:      ~p"
+               "~n   LID:       ~p"
+               "~n   size(Acc): ~p", [MCnt, BCnt, LID, size(Acc)]),
+            State
+    end.
+
+handler_process_data(Acc, Mod, Sock, LID) ->
+    handler_process_data(Acc, Mod, Sock, 0, 0, LID).
+
+%% Extract each complete request, one at a time.
+handler_process_data(<<?TTEST_TAG:32,
+		       ?TTEST_TYPE_REQUEST:32,
+ 		       ID:32,
+ 		       SZ:32,
+ 		       Rest/binary>>,
+ 		     Mod, Sock,
+ 		     MCnt, BCnt, _LID) when (size(Rest) >= SZ)  ->
+    <<Body:SZ/binary, Rest2/binary>> = Rest,
+    case handler_send_reply(Mod, Sock, ID, Body) of
+ 	ok ->
+ 	    handler_process_data(Rest2, Mod, Sock, MCnt+1, BCnt+16+SZ, ID);
+ 	{error, _} = ERROR ->
+ 	    ERROR
+    end;
+handler_process_data(Data, _Mod, _Sock, MCnt, BCnt, LID) ->
+    {ok, {MCnt, BCnt, LID}, Data}.
+	    
+	    
+handler_recv_message2(Mod, Sock) ->
+    case Mod:recv(Sock, 4*4, ?RECV_TIMEOUT) of
+        {ok, <<?TTEST_TAG:32,
+               ?TTEST_TYPE_REQUEST:32,
+               ID:32,
+               SZ:32>> = Hdr} ->
+            case Mod:recv(Sock, SZ, ?RECV_TIMEOUT) of
+                {ok, Body} when (SZ =:= size(Body)) ->
+                    {ok, {size(Hdr) + size(Body), ID, Body}};
+                {error, BReason} ->
+                    ?E("failed reading body (~w) of message ~w:"
+                       "~n   ~p", [SZ, ID, BReason]),
+                    exit({recv, body, ID, SZ, BReason})
+            end;
+        {error, timeout} = ERROR ->
+            ERROR;
+        {error, closed} = ERROR ->
+            ERROR;
+        {error, HReason} ->
+            ?E("Failed reading header of message:"
+               "~n   ~p", [HReason]),
+            exit({recv, header, HReason})
+    end.
+
+
+handler_recv_message3(Mod, Sock, Acc, LID) ->
+    receive
+        {TagClosed, Sock} when (TagClosed =:= tcp_closed) orelse
+			       (TagClosed =:= socket_closed) ->
+            {error, closed};
+
+        {TagErr, Sock, Reason} when (TagErr =:= tcp_error) orelse
+				    (TagErr =:= socket_error) ->
+            {error, Reason};
+
+        {Tag, Sock, Msg} when (Tag =:= tcp) orelse
+			      (Tag =:= socket) ->
+            handler_process_data(<<Acc/binary, Msg/binary>>, Mod, Sock, LID)
+        
+    after ?RECV_TIMEOUT ->
+            {error, timeout}
+    end.
+
+
+
+handler_send_reply(Mod, Sock, ID, Data) ->
+    SZ = size(Data),
+    Msg = <<?TTEST_TAG:32,
+	    ?TTEST_TYPE_REPLY:32,
+	    ID:32,
+	    SZ:32,
+	    Data/binary>>,
+    case Mod:send(Sock, Msg) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            (catch Mod:close(Sock)),
+            exit({send, Reason})
+    end.
+
+
+handler_done(State) ->
+    handler_done(State, ?T()).
+
+handler_done(#{start := Start,
+	       mod   := Mod,
+               sock  := Sock,
+               mcnt  := MCnt,
+               bcnt  := BCnt}, Stop) ->
+    (catch Mod:close(Sock)),
+    exit({done, ?TDIFF(Start, Stop), MCnt, BCnt}).
+
+
+handler_handle_message(#{parent := Parent} = State) ->
+    receive
+        {'EXIT', Parent, Reason} ->
+            exit({parent_exit, Reason})
+    after 0 ->
+            State
+    end.
+
+
+handler_initial_activation(_Mod, _Sock, false = _Active) ->
+    ok;
+handler_initial_activation(Mod, Sock, Active) ->
+    Mod:active(Sock, Active).
+
+
+handler_maybe_activate(Mod, Sock, once = Active) ->
+    Mod:active(Sock, Active);
+handler_maybe_activate(_, _, _) ->
+    ok.
+
+
+
+%% ==========================================================================
+
+%% which_addr() ->
+%%     case inet:getifaddrs() of
+%%         {ok, IfAddrs} ->
+%%             which_addrs(inet, IfAddrs);
+%%         {error, Reason} ->
+%%             exit({getifaddrs, Reason})
+%%     end.
+
+%% which_addrs(_Family, []) ->
+%%     exit({getifaddrs, not_found});
+%% which_addrs(Family, [{"lo", _} | IfAddrs]) ->
+%%     %% Skip
+%%     which_addrs(Family, IfAddrs);
+%% which_addrs(Family, [{"docker" ++ _, _} | IfAddrs]) ->
+%%     %% Skip docker
+%%     which_addrs(Family, IfAddrs);
+%% which_addrs(Family, [{"br-" ++ _, _} | IfAddrs]) ->
+%%     %% Skip docker
+%%     which_addrs(Family, IfAddrs);
+%% which_addrs(Family, [{"en" ++ _, IfOpts} | IfAddrs]) ->
+%%     %% Maybe take this one
+%%     case which_addr(Family, IfOpts) of
+%%         {ok, Addr} ->
+%%             Addr;
+%%         error ->
+%%             which_addrs(Family, IfAddrs)
+%%     end;
+%% which_addrs(Family, [{_IfName, IfOpts} | IfAddrs]) ->
+%%     case which_addr(Family, IfOpts) of
+%%         {ok, Addr} ->
+%%             Addr;
+%%         error ->
+%%             which_addrs(Family, IfAddrs)
+%%     end.
+
+%% which_addr(_, []) ->
+%%     error;
+%% which_addr(inet, [{addr, Addr}|_])
+%%   when is_tuple(Addr) andalso (size(Addr) =:= 4) ->
+%%     {ok, Addr};
+%% which_addr(inet6, [{addr, Addr}|_])
+%%   when is_tuple(Addr) andalso (size(Addr) =:= 8) ->
+%%     {ok, Addr};
+%% which_addr(Family, [_|IfOpts]) ->
+%%     which_addr(Family, IfOpts).
+
+
+%% ==========================================================================
+
+req(Pid, Req) ->
+    Ref = make_ref(),
+    Pid ! {?MODULE, Ref, self(), Req},
+    receive
+        {'EXIT', Pid, Reason} ->
+            {error, {exit, Reason}};
+        {?MODULE, Ref, Reply} ->
+            Reply
+    end.
+
+reply(Pid, Ref, Reply) ->
+    Pid ! {?MODULE, Ref, Reply}.
+
+
+%% ==========================================================================
+
+%% t() ->
+%%     os:timestamp().
+
+%% tdiff({A1, B1, C1} = _T1x, {A2, B2, C2} = _T2x) ->
+%%     T1 = A1*1000000000+B1*1000+(C1 div 1000), 
+%%     T2 = A2*1000000000+B2*1000+(C2 div 1000), 
+%%     T2 - T1.
+
+%% formated_timestamp() ->
+%%     format_timestamp(os:timestamp()).
+
+%% format_timestamp({_N1, _N2, N3} = TS) ->
+%%     {_Date, Time}  = calendar:now_to_local_time(TS),
+%%     {Hour,Min,Sec} = Time,
+%%     FormatTS = io_lib:format("~.2.0w:~.2.0w:~.2.0w.4~w",
+%%                              [Hour, Min, Sec, round(N3/1000)]),  
+%%     lists:flatten(FormatTS).
+
+%% %% Time is always in number os ms (milli seconds)
+%% format_time(T) ->
+%%     f("~p", [T]).
+
+
+%% ==========================================================================
+
+%% f(F, A) ->
+%%     lists:flatten(io_lib:format(F, A)).
+
+%% e(F, A) ->
+%%     p(get(sname), "<ERROR> " ++ F, A).
+
+%% i(F) ->
+%%     i(F, []).
+
+%% i(F, A) ->
+%%     p(get(sname), "<INFO> " ++ F, A).
+
+%% p(undefined, F, A) ->
+%%     p("- ", F, A);
+%% p(Prefix, F, A) ->
+%%     io:format("[~s, ~s] " ++ F ++ "~n", [formated_timestamp(), Prefix |A]).
+
diff --git a/erts/emulator/test/socket_test_ttest_tcp_server_gen.erl b/erts/emulator/test/socket_test_ttest_tcp_server_gen.erl
new file mode 100644
index 0000000000..fdf40f1369
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_tcp_server_gen.erl
@@ -0,0 +1,39 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_ttest_tcp_server_gen).
+
+-export([
+         start/1, start/2,
+         stop/1
+        ]).
+
+-define(TRANSPORT_MOD, socket_test_ttest_tcp_gen).
+-define(MOD(D),        {?TRANSPORT_MOD, #{domain => D}}).
+
+start(Active) ->
+    start(inet, Active).
+
+start(Domain, Active) ->
+    socket_test_ttest_tcp_server:start(?MOD(Domain), Active).
+            
+
+stop(Pid) ->
+    socket_test_ttest_tcp_server:stop(Pid).
diff --git a/erts/emulator/test/socket_test_ttest_tcp_server_socket.erl b/erts/emulator/test/socket_test_ttest_tcp_server_socket.erl
new file mode 100644
index 0000000000..4045bf4e4e
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_tcp_server_socket.erl
@@ -0,0 +1,46 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_ttest_tcp_server_socket).
+
+-export([
+         start/4,
+         stop/1
+        ]).
+
+-define(TRANSPORT_MOD, socket_test_ttest_tcp_socket).
+%% -define(MOD(M),        {?TRANSPORT_MOD, #{async          => false, 
+%%                                           method         => M,
+%%                                           stats_interval => 10000}}).
+-define(MOD(D,M,A),      {?TRANSPORT_MOD, #{domain => D,
+                                            async  => A,
+                                            method => M}}).
+
+start(Method, Domain, Async, Active) ->
+    socket_test_ttest_tcp_server:start(?MOD(Domain, Method, Async), Active).
+    %%     {ok, {Pid, AddrPort}} ->
+    %%         MRef = erlang:monitor(process, Pid),
+    %%         {ok, {Pid, MRef, AddrPort}};
+    %%     {error, _} = ERROR ->
+    %%         ERROR
+    %% end.
+
+stop(Pid) ->
+    socket_test_ttest_tcp_server:stop(Pid).
diff --git a/erts/emulator/test/socket_test_ttest_tcp_socket.erl b/erts/emulator/test/socket_test_ttest_tcp_socket.erl
new file mode 100644
index 0000000000..9112748b4c
--- /dev/null
+++ b/erts/emulator/test/socket_test_ttest_tcp_socket.erl
@@ -0,0 +1,724 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(socket_test_ttest_tcp_socket).
+
+-export([
+	 accept/1, accept/2,
+	 active/2,
+	 close/1,
+	 connect/1, connect/2, connect/3,
+	 controlling_process/2,
+	 listen/0, listen/1, listen/2,
+	 port/1,
+	 peername/1,
+	 recv/2, recv/3,
+	 send/2,
+	 shutdown/2,
+	 sockname/1
+	]).
+
+
+-define(LIB, socket_test_lib).
+
+-define(READER_RECV_TIMEOUT, 1000).
+
+-define(DATA_MSG(Sock, Method, Data),
+        {socket,
+         #{sock => Sock, reader => self(), method => Method},
+         Data}).
+
+-define(CLOSED_MSG(Sock, Method),
+        {socket_closed,
+         #{sock => Sock, reader => self(), method => Method}}).
+
+-define(ERROR_MSG(Sock, Method, Reason),
+        {socket_error,
+         #{sock => Sock, reader => self(), method => Method},
+         Reason}).
+
+
+%% ==========================================================================
+
+%% This does not really work. Its just a placeholder for the time being...
+
+%% getopt(Sock, Opt) when is_atom(Opt) ->
+%%     socket:getopt(Sock, socket, Opt).
+
+%% setopt(Sock, Opt, Value) when is_atom(Opt) ->
+%%     socket:setopts(Sock, socket, Opt, Value).
+
+
+%% ==========================================================================
+
+%% The way we use server async its no point in doing a async accept call
+%% (we do never actually run the test with more than one client).
+accept(#{sock := LSock, opts := #{async  := Async,
+                                  method := Method} = Opts}) ->
+    case socket:accept(LSock) of
+        {ok, Sock} ->
+	    Self = self(),
+	    Reader = spawn(fun() ->
+                                   reader_init(Self, Sock, Async, false, Method)
+                           end),
+            maybe_start_stats_timer(Opts, Reader),
+	    {ok, #{sock => Sock, reader => Reader, method => Method}};
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+%% If a timeout has been explictly specified, then we do not use
+%% async here. We will pass it on to the reader process.
+accept(#{sock := LSock, opts := #{async  := Async,
+                                  method := Method} = Opts}, Timeout) ->
+    case socket:accept(LSock, Timeout) of
+	{ok, Sock} ->
+	    Self = self(),
+	    Reader = spawn(fun() ->
+                                   reader_init(Self, Sock, Async, false, Method)
+                           end),
+            maybe_start_stats_timer(Opts, Reader),
+	    {ok, #{sock => Sock, reader => Reader, method => Method}};
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+
+active(#{reader := Pid}, NewActive) 
+  when (is_boolean(NewActive) orelse (NewActive =:= once)) ->
+    Pid ! {?MODULE, active, NewActive},
+    ok.
+
+
+close(#{sock := Sock, reader := Pid}) ->
+    Pid ! {?MODULE, stop},
+    Unlink = case socket:sockname(Sock) of
+                 {ok, #{family := local, path := Path}} ->
+                     fun() -> os:cmd("unlink " ++ Path), ok end;
+                 _ ->
+                     fun() -> ok end
+             end,
+    Res = socket:close(Sock),
+    Unlink(),
+    Res.
+
+%% Create a socket and connect it to a peer
+connect(ServerPath) when is_list(ServerPath) ->
+    Domain     = local,
+    ClientPath = mk_unique_path(),
+    LocalSA    = #{family => Domain,
+                   path   => ClientPath},
+    ServerSA   = #{family => Domain, path => ServerPath},
+    Opts       = #{domain => Domain,
+                   proto  => default,
+                   method => plain},
+    Cleanup = fun() -> os:cmd("unlink " ++ ClientPath), ok end,
+    do_connect(LocalSA, ServerSA, Cleanup, Opts).
+
+connect(Addr, Port) when is_tuple(Addr) andalso is_integer(Port) ->
+    Domain   = inet,
+    LocalSA  = any,
+    ServerSA = #{family => Domain,
+                 addr   => Addr,
+                 port   => Port},
+    Opts     = #{domain => Domain,
+                 proto  => tcp,
+                 method => plain},
+    Cleanup  = fun() -> ok end,
+    do_connect(LocalSA, ServerSA, Cleanup, Opts);
+connect(ServerPath,
+        #{domain := local = Domain} = Opts)
+  when is_list(ServerPath) ->
+    ClientPath = mk_unique_path(),
+    LocalSA    = #{family => Domain,
+                   path   => ClientPath},
+    ServerSA   = #{family => Domain,
+                   path   => ServerPath},
+    Cleanup    = fun() -> os:cmd("unlink " ++ ClientPath), ok end,
+    do_connect(LocalSA, ServerSA, Cleanup, Opts#{proto => default}).
+
+connect(Addr, Port, #{domain := Domain} = Opts) ->
+    LocalSA  = any,
+    ServerSA = #{family => Domain,
+                 addr   => Addr,
+                 port   => Port},
+    Cleanup  = fun() -> ok end,
+    do_connect(LocalSA, ServerSA, Cleanup, Opts#{proto => tcp}).
+
+do_connect(LocalSA, ServerSA, Cleanup, #{domain := Domain,
+                                         proto  := Proto,
+                                         async  := Async,
+                                         method := Method} = Opts) ->
+    try
+	begin
+	    Sock =
+		case socket:open(Domain, stream, Proto) of
+		    {ok, S} ->
+			S;
+		    {error, OReason} ->
+			throw({error, {open, OReason}})
+		end,
+	    case socket:bind(Sock, LocalSA) of
+		{ok, _} ->
+		    ok;
+		{error, BReason} ->
+		    (catch socket:close(Sock)),
+                    Cleanup(),
+		    throw({error, {bind, BReason}})
+	    end,
+	    case socket:connect(Sock, ServerSA) of
+		ok ->
+		    ok;
+		{error, CReason} ->
+		    (catch socket:close(Sock)),
+                    Cleanup(),
+		    throw({error, {connect, CReason}})
+	    end,
+	    Self   = self(),
+	    Reader = spawn(fun() ->
+                                   reader_init(Self, Sock, Async, false, Method)
+                           end),
+            maybe_start_stats_timer(Opts, Reader),
+	    {ok, #{sock => Sock, reader => Reader, method => Method}}
+	end
+    catch
+	throw:ERROR:_ ->
+	    ERROR
+    end.
+
+mk_unique_path() ->
+    [NodeName | _] = string:tokens(atom_to_list(node()), [$@]),
+    ?LIB:f("/tmp/esock_~s_~w", [NodeName, erlang:system_time(nanosecond)]).
+
+maybe_start_stats_timer(#{stats_to       := Pid,
+                          stats_interval := T},
+                        Reader) when is_pid(Pid) ->
+    erlang:start_timer(T, Pid, {stats, T, "reader", Reader});
+maybe_start_stats_timer(_O, _) ->
+    ok.
+
+controlling_process(#{sock := Sock, reader := Pid}, NewPid) ->
+    case socket:setopt(Sock, otp, controlling_process, NewPid) of
+	ok ->
+	    Pid ! {?MODULE, self(), controlling_process, NewPid},
+	    receive
+		{?MODULE, Pid, controlling_process} ->
+		    ok
+	    end;
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+
+%% Create a listen socket
+listen() ->
+    listen(0).
+
+listen(Port) when is_integer(Port) ->
+    listen(Port, #{domain => inet, async => false, method => plain});
+listen(Path) when is_list(Path) ->
+    listen(Path, #{domain => local, async => false, method => plain}).
+
+listen(0, #{domain := local} = Opts) ->
+    listen(mk_unique_path(), Opts);
+listen(Path, #{domain := local = Domain} = Opts)
+  when is_list(Path) andalso (Path =/= []) ->
+    SA = #{family => Domain,
+           path   => Path},
+    Cleanup = fun() -> os:cmd("unlink " ++ Path), ok end,
+    do_listen(SA, Cleanup, Opts#{proto => default});
+listen(Port, #{domain := Domain} = Opts)
+  when is_integer(Port) andalso (Port >= 0) ->
+    %% Bind fills in the rest
+    case ?LIB:which_local_host_info(Domain) of
+	{ok, {_, _, Addr}} ->
+	    SA = #{family => Domain,
+		   addr   => Addr,
+		   port   => Port},
+	    Cleanup = fun() -> ok end,
+	    do_listen(SA, Cleanup, Opts#{proto => tcp});
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+do_listen(SA,
+          Cleanup,
+          #{domain := Domain, proto  := Proto, 
+            async  := Async,  method := Method} = Opts)
+  when (Method =:= plain) orelse (Method =:= msg) andalso
+       is_boolean(Async) ->
+    try
+	begin
+	    Sock = case socket:open(Domain, stream, Proto) of
+		       {ok, S} ->
+			   S;
+		       {error, OReason} ->
+			   throw({error, {open, OReason}})
+		   end,
+	    case socket:bind(Sock, SA) of
+		{ok, _} ->
+		    ok;
+		{error, BReason} ->
+		    (catch socket:close(Sock)),
+                    Cleanup(),
+		    throw({error, {bind, BReason}})
+	    end,
+	    case socket:listen(Sock) of
+		ok ->
+                    ok;
+                {error, LReason} ->
+		    (catch socket:close(Sock)),
+                    Cleanup(),
+                    throw({error, {listen, LReason}})
+            end,
+	    {ok, #{sock => Sock, opts => Opts}}
+	end
+    catch
+	throw:{error, Reason}:_ ->
+	    {error, Reason}
+    end.
+
+
+port(#{sock := Sock}) ->
+    case socket:sockname(Sock) of
+	{ok, #{family := local, path := Path}} ->
+	    {ok, Path};
+	{ok, #{port := Port}} ->
+	    {ok, Port};
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+
+peername(#{sock := Sock}) ->
+    case socket:peername(Sock) of
+	{ok, #{family := local, path := Path}} ->
+	    {ok, Path};
+	{ok, #{addr := Addr, port := Port}} ->
+	    {ok, {Addr, Port}};
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+
+recv(#{sock := Sock, method := plain}, Length) ->
+    socket:recv(Sock, Length);
+recv(#{sock := Sock, method := msg}, Length) ->
+    case socket:recvmsg(Sock, Length, 0, [], infinity) of
+        {ok, #{iov := [Bin]}} ->
+            {ok, Bin};
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+recv(#{sock := Sock, method := plain}, Length, Timeout) ->
+    socket:recv(Sock, Length, Timeout);
+recv(#{sock := Sock, method := msg}, Length, Timeout) ->
+    case socket:recvmsg(Sock, Length, 0, [], Timeout) of
+        {ok, #{iov := [Bin]}} ->
+            {ok, Bin};
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+
+send(#{sock := Sock, method := plain}, Bin) ->
+    socket:send(Sock, Bin);
+send(#{sock := Sock, method := msg}, Bin) ->
+    socket:sendmsg(Sock, #{iov => [Bin]}).
+
+
+shutdown(#{sock := Sock}, How) ->
+    socket:shutdown(Sock, How).
+
+
+sockname(#{sock := Sock}) ->
+    case socket:sockname(Sock) of
+	{ok, #{addr := Addr, port := Port}} ->
+	    {ok, {Addr, Port}};
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+
+%% ==========================================================================
+
+reader_init(ControllingProcess, Sock, Async, Active, Method) 
+  when is_pid(ControllingProcess) andalso
+       is_boolean(Async) andalso
+       (is_boolean(Active) orelse (Active =:= once)) andalso 
+       ((Method =:= plain) orelse (Method =:= msg)) ->
+    put(verbose, false),
+    MRef = erlang:monitor(process, ControllingProcess),
+    reader_loop(#{ctrl_proc      => ControllingProcess,
+		  ctrl_proc_mref => MRef,
+                  async          => Async,
+                  select_info    => undefined,
+                  select_num     => 0, % Count the number of select messages
+		  active         => Active,
+		  sock           => Sock,
+                  method         => Method}).
+
+
+%% Never read
+reader_loop(#{active    := false,
+	      ctrl_proc := Pid} = State) ->
+    receive
+	{?MODULE, stop} ->
+            reader_exit(State, stop);
+
+	{?MODULE, Pid, controlling_process, NewPid} ->
+	    OldMRef = maps:get(ctrl_proc_mref, State),
+	    erlang:demonitor(OldMRef, [flush]),
+	    NewMRef = erlang:monitor(process, NewPid),
+	    Pid ! {?MODULE, self(), controlling_process},
+	    reader_loop(State#{ctrl_proc      => NewPid,
+			       ctrl_proc_mref => NewMRef});
+
+	{?MODULE, active, NewActive} ->
+	    reader_loop(State#{active => NewActive});
+
+	{'DOWN', MRef, process, Pid, Reason} ->
+	    case maps:get(ctrl_proc_mref, State) of
+		MRef ->
+                    reader_exit(State, {ctrl_exit, Reason});
+		_ ->
+		    reader_loop(State)
+	    end
+    end;
+
+%% Read *once* and then change to false
+reader_loop(#{active    := once,
+	      async     := false,
+              sock      := Sock,
+              method    := Method,
+	      ctrl_proc := Pid} = State) ->
+    case do_recv(Method, Sock) of
+	{ok, Data} ->
+	    Pid ! ?DATA_MSG(Sock, Method, Data),
+	    reader_loop(State#{active => false});
+	{error, timeout} ->
+	    receive
+		{?MODULE, stop} ->
+		    reader_exit(State, stop);
+
+		{?MODULE, Pid, controlling_process, NewPid} ->
+		    OldMRef = maps:get(ctrl_proc_mref, State),
+		    erlang:demonitor(OldMRef, [flush]),
+		    NewMRef = erlang:monitor(process, NewPid),
+		    Pid ! {?MODULE, self(), controlling_process},
+		    reader_loop(State#{ctrl_proc      => NewPid,
+				       ctrl_proc_mref => NewMRef});
+
+		{?MODULE, active, NewActive} ->
+		    reader_loop(State#{active => NewActive});
+
+		{'DOWN', MRef, process, Pid, Reason} ->
+		    case maps:get(ctrl_proc_mref, State) of
+                        MRef ->
+                            reader_exit(State, {ctrl_exit, Reason});
+			_ ->
+			    reader_loop(State)
+		    end
+	    after 0 ->
+		    reader_loop(State)
+	    end;
+
+	{error, closed} = E1 ->
+            Pid ! ?CLOSED_MSG(Sock, Method),
+            reader_exit(State, E1);
+
+	{error, Reason} = E2 ->
+	    Pid ! ?ERROR_MSG(Sock, Method, Reason),
+            reader_exit(State, E2)
+    end;
+reader_loop(#{active      := once,
+	      async       := true,
+              select_info := undefined,
+              sock        := Sock,
+              method      := Method,
+	      ctrl_proc   := Pid} = State) ->
+    case do_recv(Method, Sock, nowait) of
+        {select, SelectInfo} ->
+            reader_loop(State#{select_info => SelectInfo});
+	{ok, Data} ->
+	    Pid ! ?DATA_MSG(Sock, Method, Data),
+	    reader_loop(State#{active => false});
+
+	{error, closed} = E1 ->
+	    Pid ! ?CLOSED_MSG(Sock, Method),
+            reader_exit(State, E1);
+
+	{error, Reason} = E2 ->
+	    Pid ! ?ERROR_MSG(Sock, Method, Reason),
+            reader_exit(State, E2)
+    end;
+reader_loop(#{active      := once,
+	      async       := true,
+              select_info := {select_info, _, Ref},
+              select_num  := N,
+              sock        := Sock,
+              method      := Method,
+	      ctrl_proc   := Pid} = State) ->
+    receive
+        {?MODULE, stop} ->
+            reader_exit(State, stop);
+        
+        {?MODULE, Pid, controlling_process, NewPid} ->
+            OldMRef = maps:get(ctrl_proc_mref, State),
+            erlang:demonitor(OldMRef, [flush]),
+            NewMRef = erlang:monitor(process, NewPid),
+            Pid ! {?MODULE, self(), controlling_process},
+            reader_loop(State#{ctrl_proc      => NewPid,
+                               ctrl_proc_mref => NewMRef});
+        
+        {?MODULE, active, NewActive} ->
+            reader_loop(State#{active => NewActive});
+        
+        {'DOWN', MRef, process, Pid, Reason} ->
+            case maps:get(ctrl_proc_mref, State) of
+                MRef ->
+                    reader_exit(State, {ctrl_exit, Reason});
+                _ ->
+                    reader_loop(State)
+            end;
+
+        {'$socket', Sock, select, Ref} ->
+            case do_recv(Method, Sock, nowait) of
+                {ok, Data} when is_binary(Data) ->
+                    Pid ! ?DATA_MSG(Sock, Method, Data),
+                    reader_loop(State#{active      => false,
+                                       select_info => undefined,
+                                       select_num  => N+1});
+                
+                {error, closed} = E1 ->
+                    Pid ! ?CLOSED_MSG(Sock, Method),
+                    reader_exit(State, E1);
+                
+                {error, Reason} = E2 ->
+                    Pid ! ?ERROR_MSG(Sock, Method, Reason),
+                    reader_exit(State, E2)
+            end
+    end;
+
+%% Read and forward data continuously
+reader_loop(#{active    := true,
+	      async     := false,
+	      sock      := Sock,
+              method    := Method,
+	      ctrl_proc := Pid} = State) ->
+    case do_recv(Method, Sock) of
+	{ok, Data} ->
+	    Pid ! ?DATA_MSG(Sock, Method, Data),
+	    reader_loop(State);
+	{error, timeout} ->
+	    receive
+		{?MODULE, stop} ->
+                    reader_exit(State, stop);
+
+		{?MODULE, Pid, controlling_process, NewPid} ->
+		    OldMRef = maps:get(ctrl_proc_mref, State),
+		    erlang:demonitor(OldMRef, [flush]),
+		    NewMRef = erlang:monitor(process, NewPid),
+		    Pid ! {?MODULE, self(), controlling_process},
+		    reader_loop(State#{ctrl_proc      => NewPid,
+				       ctrl_proc_mref => NewMRef});
+
+		{?MODULE, active, NewActive} ->
+		    reader_loop(State#{active => NewActive});
+
+		{'DOWN', MRef, process, Pid, Reason} ->
+		    case maps:get(ctrl_proc_mref, State) of
+			MRef ->
+                            reader_exit(State, {ctrl_exit, Reason});
+			_ ->
+			    reader_loop(State)
+		    end
+	    after 0 ->
+		    reader_loop(State)
+	    end;
+
+	{error, closed} = E1 ->
+	    Pid ! ?CLOSED_MSG(Sock, Method),
+            reader_exit(State, E1);
+
+	{error, Reason} = E2 ->
+	    Pid ! ?ERROR_MSG(Sock, Method, Reason),
+            reader_exit(State, E2)
+    end;
+reader_loop(#{active      := true,
+	      async       := true,
+              select_info := undefined,
+	      sock        := Sock,
+              method      := Method,
+	      ctrl_proc   := Pid} = State) ->
+    case do_recv(Method, Sock) of
+        {select, SelectInfo} ->
+            reader_loop(State#{select_info => SelectInfo});
+	{ok, Data} ->
+	    Pid ! ?DATA_MSG(Sock, Method, Data),
+	    reader_loop(State);
+
+	{error, closed} = E1 ->
+	    Pid ! ?CLOSED_MSG(Sock, Method),
+            reader_exit(State, E1);
+
+	{error, Reason} = E2 ->
+	    Pid ! ?ERROR_MSG(Sock, Method, Reason),
+            reader_exit(State, E2)
+    end;
+reader_loop(#{active      := true,
+	      async       := true,
+              select_info := {select_info, _, Ref},
+              select_num  := N,
+	      sock        := Sock,
+              method      := Method,
+	      ctrl_proc   := Pid} = State) ->
+    receive
+        {?MODULE, stop} ->
+            reader_exit(State, stop);
+        
+        {?MODULE, Pid, controlling_process, NewPid} ->
+            OldMRef = maps:get(ctrl_proc_mref, State),
+            erlang:demonitor(OldMRef, [flush]),
+            NewMRef = erlang:monitor(process, NewPid),
+            Pid ! {?MODULE, self(), controlling_process},
+            reader_loop(State#{ctrl_proc      => NewPid,
+                               ctrl_proc_mref => NewMRef});
+        
+        {?MODULE, active, NewActive} ->
+            reader_loop(State#{active => NewActive});
+        
+        {'DOWN', MRef, process, Pid, Reason} ->
+            case maps:get(ctrl_proc_mref, State) of
+                MRef ->
+                    reader_exit(State, {ctrl_exit, Reason});
+                _ ->
+                    reader_loop(State)
+            end;
+
+        {'$socket', Sock, select, Ref} ->
+            case do_recv(Method, Sock, nowait) of
+                {ok, Data} when is_binary(Data) ->
+                    Pid ! ?DATA_MSG(Sock, Method, Data),
+                    reader_loop(State#{select_info => undefined,
+                                       select_num  => N+1});
+                
+                {error, closed} = E1 ->
+                    Pid ! ?CLOSED_MSG(Sock, Method),
+                    reader_exit(State, E1);
+                
+                {error, Reason} = E2 ->
+                    Pid ! ?ERROR_MSG(Sock, Method, Reason),
+                    reader_exit(State, E2)
+            end
+    end.
+
+
+do_recv(Method, Sock) ->
+    do_recv(Method, Sock, ?READER_RECV_TIMEOUT).
+
+do_recv(plain, Sock, Timeout) ->
+    socket:recv(Sock, 0, Timeout);
+do_recv(msg, Sock, Timeout) ->
+    case socket:recvmsg(Sock, 0, 0, [], Timeout) of
+        {ok, #{iov := [Bin]}} ->
+            {ok, Bin};
+        {select, _} = SELECT ->
+            SELECT;
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+
+reader_exit(#{async := false, active := Active}, stop) ->
+    vp("reader stopped when active: ~w", [Active]),
+    exit(normal);
+reader_exit(#{async       := true, 
+              active      := Active,
+              select_info := SelectInfo,
+              select_num  := N}, stop) ->
+    vp("reader stopped when active: ~w"
+       "~n   Current select info:       ~p"
+       "~n   Number of select messages: ~p", [Active, SelectInfo, N]),
+    exit(normal);
+reader_exit(#{async := false, active := Active}, {ctrl_exit, normal}) ->
+    vp("reader ctrl exit when active: ~w", [Active]),
+    exit(normal);
+reader_exit(#{async       := true, 
+              active      := Active,
+              select_info := SelectInfo,
+              select_num  := N}, {ctrl_exit, normal}) ->
+    vp("reader ctrl exit when active: ~w"
+       "~n   Current select info:       ~p"
+       "~n   Number of select messages: ~p", [Active, SelectInfo, N]),
+    exit(normal);
+reader_exit(#{async := false, active := Active}, {ctrl_exit, Reason}) ->
+    vp("reader exit when ctrl crash when active: ~w", [Active]),
+    exit({controlling_process, Reason});
+reader_exit(#{async       := true, 
+              active      := Active,
+              select_info := SelectInfo,
+              select_num  := N}, {ctrl_exit, Reason}) ->
+    vp("reader exit when ctrl crash when active: ~w"
+       "~n   Current select info:       ~p"
+       "~n   Number of select messages: ~p", [Active, SelectInfo, N]),
+    exit({controlling_process, Reason});
+reader_exit(#{async := false, active := Active}, {error, closed}) ->
+    vp("reader exit when socket closed when active: ~w", [Active]),
+    exit(normal);
+reader_exit(#{async       := true, 
+              active      := Active,
+              select_info := SelectInfo,
+              select_num  := N}, {error, closed}) ->
+    vp("reader exit when socket closed when active: ~w "
+       "~n   Current select info:       ~p"
+       "~n   Number of select messages: ~p", [Active, SelectInfo, N]),
+    exit(normal);
+reader_exit(#{async := false, active := Active}, {error, Reason}) ->
+    vp("reader exit when socket error when active: ~w", [Active]),
+    exit(Reason);
+reader_exit(#{async       := true, 
+              active      := Active,
+              select_info := SelectInfo,
+              select_num  := N}, {error, Reason}) ->
+    vp("reader exit when socket error when active: ~w: "
+       "~n   Current select info:       ~p"
+       "~n   Number of select messages: ~p", [Active, SelectInfo, N]),
+    exit(Reason).
+
+
+
+
+
+
+%% ==========================================================================
+
+vp(F, A) ->
+    vp(get(verbose), F, A).
+
+vp(true, F, A) ->
+    p(F, A);
+vp(_, _, _) ->
+    ok.
+
+p(F, A) ->
+    io:format(F ++ "~n", A).
+
diff --git a/erts/emulator/test/statistics_SUITE.erl b/erts/emulator/test/statistics_SUITE.erl
index ae3099633a..d278ac86c7 100644
--- a/erts/emulator/test/statistics_SUITE.erl
+++ b/erts/emulator/test/statistics_SUITE.erl
@@ -93,25 +93,34 @@ wall_clock_zero_diff1(0) ->
 %% statistics(wall_clock) are compatible, and are within a small number
 %% of ms of the amount of real time we waited for.
 wall_clock_update(Config) when is_list(Config) ->
-    wall_clock_update1(6).
+    N = 10,
+    Inc = 200,
+    TotalTime = wall_clock_update1(N, Inc, 0),
+    Overhead = TotalTime - N * Inc,
+    IsDebug = test_server:is_debug(),
 
-wall_clock_update1(N) when N > 0 ->
-    {T1_wc_time, _} = statistics(wall_clock),
-    receive after 1000 -> ok end,
-    {T2_wc_time, Wc_Diff} = statistics(wall_clock),
-
-    Wc_Diff = T2_wc_time - T1_wc_time,
-    io:format("Wall clock diff = ~p; should be  = 1000..1040~n", [Wc_Diff]),
-    case test_server:is_debug() of
-        false ->
-            true = Wc_Diff =< 1040;
+    %% Check that the average overhead is reasonable.
+    if
+        Overhead < N * 100 ->
+            ok;
+        IsDebug, Overhead < N * 1000 ->
+            ok;
         true ->
-            true = Wc_Diff =< 2000	%Be more tolerant in debug-compiled emulator.
-    end,
-    true = Wc_Diff >= 1000,
-    wall_clock_update1(N-1);
-wall_clock_update1(0) ->
-    ok.
+            io:format("There was an overhead of ~p ms during ~p rounds.",
+                      [Overhead,N]),
+            ct:fail(too_much_overhead)
+    end.
+
+wall_clock_update1(N, Inc, Total) when N > 0 ->
+    {Time1, _} = statistics(wall_clock),
+    receive after Inc -> ok end,
+    {Time2, WcDiff} = statistics(wall_clock),
+    WcDiff = Time2 - Time1,
+    io:format("Wall clock diff = ~p (expected at least ~p)\n", [WcDiff,Inc]),
+    true = WcDiff >= Inc,
+    wall_clock_update1(N-1, Inc, Total + WcDiff);
+wall_clock_update1(0, _, Total) ->
+    Total.
 
 
 %%% Test statistics(runtime).
diff --git a/erts/emulator/test/system_info_SUITE.erl b/erts/emulator/test/system_info_SUITE.erl
index 21ab6b378a..b48be3dd04 100644
--- a/erts/emulator/test/system_info_SUITE.erl
+++ b/erts/emulator/test/system_info_SUITE.erl
@@ -37,8 +37,12 @@
 
 -export([process_count/1, system_version/1, misc_smoke_tests/1,
          heap_size/1, wordsize/1, memory/1, ets_limit/1, atom_limit/1,
-         ets_count/1,
-         atom_count/1]).
+         procs_bug/1,
+         ets_count/1, atom_count/1, system_logger/1]).
+
+-export([init/1, handle_event/2, handle_call/2]).
+
+-export([init_per_testcase/2, end_per_testcase/2]).
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
@@ -46,8 +50,20 @@ suite() ->
 
 all() -> 
     [process_count, system_version, misc_smoke_tests,
-     ets_count,
-     heap_size, wordsize, memory, ets_limit, atom_limit, atom_count].
+     ets_count, heap_size, wordsize, memory, ets_limit, atom_limit, atom_count,
+     procs_bug,
+     system_logger].
+
+
+init_per_testcase(procs_bug, Config) ->
+    procs_bug(init_per_testcase, Config);
+init_per_testcase(_, Config) ->
+    Config.
+
+end_per_testcase(procs_bug, Config) ->
+    procs_bug(end_per_testcase, Config);
+end_per_testcase(_, _) ->
+    ok.
 
 %%%
 %%% The test cases -------------------------------------------------------------
@@ -457,11 +473,16 @@ cmp_memory(MWs, Str) ->
     %% Total, processes, processes_used, and system will seldom
     %% give us exactly the same result since the two readings
     %% aren't taken atomically.
+    %%
+    %% Torerance is scaled according to the number of schedulers
+    %% to match spawn_mem_workers.
+
+    Tolerance = 1.05 + 0.01 * erlang:system_info(schedulers_online),
 
-    cmp_memory(total, EM, EDM, 1.05),
-    cmp_memory(processes, EM, EDM, 1.05),
-    cmp_memory(processes_used, EM, EDM, 1.05),
-    cmp_memory(system, EM, EDM, 1.05),
+    cmp_memory(total, EM, EDM, Tolerance),
+    cmp_memory(processes, EM, EDM, Tolerance),
+    cmp_memory(processes_used, EM, EDM, Tolerance),
+    cmp_memory(system, EM, EDM, Tolerance),
 
     ok.
     
@@ -573,3 +594,116 @@ atom_count(Config) when is_list(Config) ->
     true = Limit >= Count2,
     true = Count2 > Count1,
     ok.
+
+
+system_logger(Config) when is_list(Config) ->
+
+    TC = self(),
+
+    ok = error_logger:add_report_handler(?MODULE, [TC]),
+
+    generate_log_event(),
+
+    flush(1, report_handler),
+
+    Initial = erlang:system_info(system_logger),
+
+    {Logger,_} = spawn_monitor(fun F() -> receive M -> TC ! {system_logger,M}, F() end end),
+
+    Initial = erlang:system_flag(system_logger, Logger),
+    Logger = erlang:system_info(system_logger),
+
+    generate_log_event(),
+    flush(1, system_logger),
+
+    Logger = erlang:system_flag(system_logger, Logger),
+
+    generate_log_event(),
+    flush(1, system_logger),
+
+    exit(Logger, die),
+    receive {'DOWN',_,_,_,_} -> ok end,
+
+    generate_log_event(),
+    flush(1, report_handler),
+
+    logger = erlang:system_info(system_logger),
+
+    logger = erlang:system_flag(system_logger, undefined),
+    generate_log_event(),
+    flush(),
+
+    undefined = erlang:system_flag(system_logger, Initial),
+
+    ok.
+
+flush() ->
+    receive
+        M ->
+            ct:fail({unexpected_message, M})
+    after 0 ->
+            ok
+    end.
+
+flush(0, _Pat) ->
+    flush();
+flush(Cnt, Pat) ->
+    receive
+        M when element(1,M) =:= Pat ->
+            ct:log("~p",[M]),
+            flush(Cnt-1, Pat)
+    after 500 ->
+            ct:fail({missing, Cnt, Pat})
+    end.
+
+generate_log_event() ->
+    {_Pid, Ref} = spawn_monitor(fun() -> ok = nok end),
+    receive {'DOWN', Ref, _, _, _} -> ok end.
+
+init([To]) ->
+    {ok, To}.
+
+handle_call(Msg, State) ->
+    {ok, Msg, State}.
+
+handle_event(Event, State) ->
+    State ! {report_handler, Event},
+    {ok, State}.
+
+
+%% OTP-15909: Provoke bug that would cause VM crash
+%% if doing system_info(procs) when process have queued exit/down signals.
+procs_bug(init_per_testcase, Config) ->
+    %% Use single scheduler and process prio to starve monitoring processes
+    %% from handling their received DOWN signals.
+    OldSchedOnline = erlang:system_flag(schedulers_online,1),
+    [{schedulers_online, OldSchedOnline} | Config];
+procs_bug(end_per_testcase, Config) ->
+    erlang:system_flag(schedulers_online,
+                       proplists:get_value(schedulers_online, Config)),
+    ok.
+
+procs_bug(Config) when is_list(Config) ->
+    {Monee,_} = spawn_opt(fun () -> receive die -> ok end end,
+                         [monitor,{priority,max}]),
+    Papa = self(),
+    Pids = [begin
+                P = spawn_opt(fun () ->
+                                      erlang:monitor(process, Monee),
+                                      Papa ! {self(),ready},
+                                      receive "nada" -> no end
+                              end,
+                              [link, {priority,normal}]),
+                {P, ready} = receive M -> M end,
+                P
+            end
+            || _ <- lists:seq(1,10)],
+    process_flag(priority,high),
+    Monee ! die,
+    {'DOWN',_,process,Monee,normal} = receive M -> M end,
+
+    %% This call did crash VM as Pids have pending DOWN signals.
+    erlang:system_info(procs),
+    process_flag(priority,normal),
+    [begin unlink(P), exit(P, kill) end || P <- Pids],
+    ok.
diff --git a/erts/emulator/test/timer_bif_SUITE.erl b/erts/emulator/test/timer_bif_SUITE.erl
index fc11a04a31..15fe13c8c0 100644
--- a/erts/emulator/test/timer_bif_SUITE.erl
+++ b/erts/emulator/test/timer_bif_SUITE.erl
@@ -361,7 +361,7 @@ evil_timers(Config) when is_list(Config) ->
     %%
     %% 1. A timer started with erlang:start_timer(Time, Receiver, Msg),
     %%    where Msg is a composite term, expires, and the receivers main
-    %%    lock *can not* be acquired immediately (typically when the
+    %%    lock *cannot* be acquired immediately (typically when the
     %%    receiver *is* running).
     %%
     %%    The wrap tuple ({timeout, TRef, Msg}) will in this case
@@ -372,7 +372,7 @@ evil_timers(Config) when is_list(Config) ->
     RecvTimeOutMsgs0 = evil_recv_timeouts(200),
     %% 2. A timer started with erlang:start_timer(Time, Receiver, Msg),
     %%    where Msg is an immediate term, expires, and the receivers main
-    %%    lock *can not* be acquired immediately (typically when the
+    %%    lock *cannot* be acquired immediately (typically when the
     %%    receiver *is* running).
     %%
     %%    The wrap tuple will in this case be allocated in a new
diff --git a/erts/emulator/test/trace_local_SUITE.erl b/erts/emulator/test/trace_local_SUITE.erl
index 253d5fed23..ad802352b9 100644
--- a/erts/emulator/test/trace_local_SUITE.erl
+++ b/erts/emulator/test/trace_local_SUITE.erl
@@ -1181,7 +1181,9 @@ undef(X) ->
     ?MODULE:undef(X, X). % undef
 
 lists_reverse(A, B) ->
-    lists:reverse(A, B).
+    Res = lists:reverse(A, B),
+    _ = (catch abs(A)),
+    Res.
 
 
 
diff --git a/erts/emulator/test/z_SUITE.erl b/erts/emulator/test/z_SUITE.erl
index 1c52e1a934..6549108126 100644
--- a/erts/emulator/test/z_SUITE.erl
+++ b/erts/emulator/test/z_SUITE.erl
@@ -251,7 +251,7 @@ pollset_size(Config) when is_list(Config) ->
 	  end.
 
 check_io_debug(Config) when is_list(Config) ->
-    case lists:keysearch(name, 1, erlang:system_info(check_io)) of
+    case lists:keysearch(name, 1, hd(erlang:system_info(check_io))) of
 	      {value, {name, erts_poll}} -> check_io_debug_test();
 	      _ -> {skipped, "Not implemented in this emulator"}
 	  end.
diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops
index da994fae3e..605a402f2a 100755
--- a/erts/emulator/utils/beam_makeops
+++ b/erts/emulator/utils/beam_makeops
@@ -1488,7 +1488,7 @@ sub code_gen {
                 $var_decls .= "Eterm $tmp;\n";
                 $tmp_arg_num++;
                 push(@f, $tmp);
-                $prefix .= "GetR($arg_offset, $tmp);\n";
+                $prefix .= "GetSource(" . arg_offset($arg_offset) . ", $tmp);\n";
                 $need_block = 1;
                 last SWITCH;
             };
@@ -1840,12 +1840,57 @@ sub do_pack_one {
     }
 
     #
-    # Return if there is nothing to pack.
-    #
-    if ($packable_args == 0) {
-        return (-1);
-    } elsif ($packable_args == 1 and $options == 0) {
-        return (-1);
+    # Check whether any packing can be done.
+    #
+    my $nothing_to_pack = $packable_args == 0 ||
+        $packable_args == 1 && $options == 0;
+    if ($nothing_to_pack) {
+        # The packing engine in the loader processes the operands from
+        # right to left. Rightmost operands that are not packed must
+        # be stacked and then unstacked.
+        #
+        # Because instructions may be broken up into micro
+        # instructions, we might not see all operands at once. So
+        # there could be a micro instructions that packs the operands
+        # to the left of the current micro instruction. If that is the
+        # case, it is essential that we generate stacking and
+        # unstacking instructions even when no packing is
+        # possible. (build_pack_spec() will remove any unecessary
+        # stacking and unstacking operations.)
+        #
+        # Here is an example. Say that we have this instruction:
+        #
+        #     i_plus x x j d
+        #
+        # that comprises two micro instructions:
+        #
+        #     i_plus.fetch x x
+        #     i_plus.execute j d
+        #
+        # This function (do_pack_one()) will be called twice, once to pack
+        # 'x' and 'x', and once to pack 'j' and 'd'.
+        #
+        # On a 32-bit machine, the 'j' and 'd' operands can't be
+        # packed because 'j' requires a full word. The two 'x'
+        # operands in the i_plus.fetch micro instruction will be
+        # packed, though, so we must generate instructions for packing
+        # and unpacking the 'j' and 'd' operands.
+        my $down = '';
+        my $up = '';
+        foreach my $arg (@args) {
+            my $push = 'g';
+            if ($type_bit{$arg} & $type_bit{'q'}) {
+                # The operand may be a literal.
+                $push = 'q';
+            } elsif ($type_bit{$arg} & $type_bit{'f'}) {
+                # The operand may be a failure label.
+                $push = 'f';
+            }
+            $down = "$push${down}";
+            $up = "${up}p";
+        }
+        my $pack_spec = "$down:$up";
+        return (1, ['',$pack_spec,@args]);
     }
 
     #
@@ -2692,7 +2737,7 @@ sub tr_maybe_keep {
 		return;
 	    }
 	} elsif ($op eq 'store_var_next_arg') {
-	    return unless shift(@last_instr) eq $args[0];
+	    return unless @last_instr and shift(@last_instr) eq $args[0];
 	} elsif (defined $pos) {
 	    return;
 	}
diff --git a/erts/emulator/zlib/adler32.c b/erts/emulator/zlib/adler32.c
index c693a42b7c..d0be4380a3 100644
--- a/erts/emulator/zlib/adler32.c
+++ b/erts/emulator/zlib/adler32.c
@@ -1,20 +1,15 @@
 /* adler32.c -- compute the Adler-32 checksum of a data stream
- * Copyright (C) 1995-2011 Mark Adler
+ * Copyright (C) 1995-2011, 2016 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 /* @(#) $Id$ */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
 #include "zutil.h"
 
-#define local static
-
 local uLong adler32_combine_ OF((uLong adler1, uLong adler2, z_off64_t len2));
 
-#define BASE 65521      /* largest prime smaller than 65536 */
+#define BASE 65521U     /* largest prime smaller than 65536 */
 #define NMAX 5552
 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
 
@@ -65,10 +60,10 @@ local uLong adler32_combine_ OF((uLong adler1, uLong adler2, z_off64_t len2));
 #endif
 
 /* ========================================================================= */
-uLong ZEXPORT adler32(adler, buf, len)
+uLong ZEXPORT adler32_z(adler, buf, len)
     uLong adler;
     const Bytef *buf;
-    uInt len;
+    z_size_t len;
 {
     unsigned long sum2;
     unsigned n;
@@ -136,6 +131,15 @@ uLong ZEXPORT adler32(adler, buf, len)
 }
 
 /* ========================================================================= */
+uLong ZEXPORT adler32(adler, buf, len)
+    uLong adler;
+    const Bytef *buf;
+    uInt len;
+{
+    return adler32_z(adler, buf, len);
+}
+
+/* ========================================================================= */
 local uLong adler32_combine_(adler1, adler2, len2)
     uLong adler1;
     uLong adler2;
@@ -159,7 +163,7 @@ local uLong adler32_combine_(adler1, adler2, len2)
     sum2 += ((adler1 >> 16) & 0xffff) + ((adler2 >> 16) & 0xffff) + BASE - rem;
     if (sum1 >= BASE) sum1 -= BASE;
     if (sum1 >= BASE) sum1 -= BASE;
-    if (sum2 >= (BASE << 1)) sum2 -= (BASE << 1);
+    if (sum2 >= ((unsigned long)BASE << 1)) sum2 -= ((unsigned long)BASE << 1);
     if (sum2 >= BASE) sum2 -= BASE;
     return sum1 | (sum2 << 16);
 }
diff --git a/erts/emulator/zlib/compress.c b/erts/emulator/zlib/compress.c
index 8ecef0f790..e2db404abf 100644
--- a/erts/emulator/zlib/compress.c
+++ b/erts/emulator/zlib/compress.c
@@ -1,13 +1,10 @@
 /* compress.c -- compress a memory buffer
- * Copyright (C) 1995-2005 Jean-loup Gailly.
+ * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 /* @(#) $Id$ */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
 #define ZLIB_INTERNAL
 #include "zlib.h"
 
@@ -31,16 +28,11 @@ int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
 {
     z_stream stream;
     int err;
+    const uInt max = (uInt)-1;
+    uLong left;
 
-    stream.next_in = (z_const Bytef *)source;
-    stream.avail_in = (uInt)sourceLen;
-#ifdef MAXSEG_64K
-    /* Check for source > 64K on 16-bit machine: */
-    if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
-#endif
-    stream.next_out = dest;
-    stream.avail_out = (uInt)*destLen;
-    if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
+    left = *destLen;
+    *destLen = 0;
 
     stream.zalloc = (alloc_func)0;
     stream.zfree = (free_func)0;
@@ -49,15 +41,26 @@ int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
     err = deflateInit(&stream, level);
     if (err != Z_OK) return err;
 
-    err = deflate(&stream, Z_FINISH);
-    if (err != Z_STREAM_END) {
-        deflateEnd(&stream);
-        return err == Z_OK ? Z_BUF_ERROR : err;
-    }
-    *destLen = stream.total_out;
+    stream.next_out = dest;
+    stream.avail_out = 0;
+    stream.next_in = (z_const Bytef *)source;
+    stream.avail_in = 0;
+
+    do {
+        if (stream.avail_out == 0) {
+            stream.avail_out = left > (uLong)max ? max : (uInt)left;
+            left -= stream.avail_out;
+        }
+        if (stream.avail_in == 0) {
+            stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen;
+            sourceLen -= stream.avail_in;
+        }
+        err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);
+    } while (err == Z_OK);
 
-    err = deflateEnd(&stream);
-    return err;
+    *destLen = stream.total_out;
+    deflateEnd(&stream);
+    return err == Z_STREAM_END ? Z_OK : err;
 }
 
 /* ===========================================================================
diff --git a/erts/emulator/zlib/crc32.c b/erts/emulator/zlib/crc32.c
index ba506d8dd3..9580440c0e 100644
--- a/erts/emulator/zlib/crc32.c
+++ b/erts/emulator/zlib/crc32.c
@@ -1,5 +1,5 @@
 /* crc32.c -- compute the CRC-32 of a data stream
- * Copyright (C) 1995-2006, 2010, 2011, 2012 Mark Adler
+ * Copyright (C) 1995-2006, 2010, 2011, 2012, 2016 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  *
  * Thanks to Rodney Brown <[email protected]> for his contribution of faster
@@ -28,23 +28,17 @@
 #  endif /* !DYNAMIC_CRC_TABLE */
 #endif /* MAKECRCH */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
-
 #include "zutil.h"      /* for STDC and FAR definitions */
 
-#define local static
-
 /* Definitions for doing the crc four data bytes at a time. */
 #if !defined(NOBYFOUR) && defined(Z_U4)
 #  define BYFOUR
 #endif
 #ifdef BYFOUR
    local unsigned long crc32_little OF((unsigned long,
-                        const unsigned char FAR *, unsigned));
+                        const unsigned char FAR *, z_size_t));
    local unsigned long crc32_big OF((unsigned long,
-                        const unsigned char FAR *, unsigned));
+                        const unsigned char FAR *, z_size_t));
 #  define TBLS 8
 #else
 #  define TBLS 1
@@ -205,10 +199,10 @@ const z_crc_t FAR * ZEXPORT get_crc_table()
 #define DO8 DO1; DO1; DO1; DO1; DO1; DO1; DO1; DO1
 
 /* ========================================================================= */
-unsigned long ZEXPORT crc32(crc, buf, len)
+unsigned long ZEXPORT crc32_z(crc, buf, len)
     unsigned long crc;
     const unsigned char FAR *buf;
-    uInt len;
+    z_size_t len;
 {
     if (buf == Z_NULL) return 0UL;
 
@@ -239,8 +233,29 @@ unsigned long ZEXPORT crc32(crc, buf, len)
     return crc ^ 0xffffffffUL;
 }
 
+/* ========================================================================= */
+unsigned long ZEXPORT crc32(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    uInt len;
+{
+    return crc32_z(crc, buf, len);
+}
+
 #ifdef BYFOUR
 
+/*
+   This BYFOUR code accesses the passed unsigned char * buffer with a 32-bit
+   integer pointer type. This violates the strict aliasing rule, where a
+   compiler can assume, for optimization purposes, that two pointers to
+   fundamentally different types won't ever point to the same memory. This can
+   manifest as a problem only if one of the pointers is written to. This code
+   only reads from those pointers. So long as this code remains isolated in
+   this compilation unit, there won't be a problem. For this reason, this code
+   should not be copied and pasted into a compilation unit in which other code
+   writes to the buffer that is passed to these routines.
+ */
+
 /* ========================================================================= */
 #define DOLIT4 c ^= *buf4++; \
         c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \
@@ -251,7 +266,7 @@ unsigned long ZEXPORT crc32(crc, buf, len)
 local unsigned long crc32_little(crc, buf, len)
     unsigned long crc;
     const unsigned char FAR *buf;
-    unsigned len;
+    z_size_t len;
 {
     register z_crc_t c;
     register const z_crc_t FAR *buf4;
@@ -282,7 +297,7 @@ local unsigned long crc32_little(crc, buf, len)
 }
 
 /* ========================================================================= */
-#define DOBIG4 c ^= *++buf4; \
+#define DOBIG4 c ^= *buf4++; \
         c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \
             crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24]
 #define DOBIG32 DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4
@@ -291,7 +306,7 @@ local unsigned long crc32_little(crc, buf, len)
 local unsigned long crc32_big(crc, buf, len)
     unsigned long crc;
     const unsigned char FAR *buf;
-    unsigned len;
+    z_size_t len;
 {
     register z_crc_t c;
     register const z_crc_t FAR *buf4;
@@ -304,7 +319,6 @@ local unsigned long crc32_big(crc, buf, len)
     }
 
     buf4 = (const z_crc_t FAR *)(const void FAR *)buf;
-    buf4--;
     while (len >= 32) {
         DOBIG32;
         len -= 32;
@@ -313,7 +327,6 @@ local unsigned long crc32_big(crc, buf, len)
         DOBIG4;
         len -= 4;
     }
-    buf4++;
     buf = (const unsigned char FAR *)buf4;
 
     if (len) do {
diff --git a/erts/emulator/zlib/deflate.c b/erts/emulator/zlib/deflate.c
index 943c26dfb2..1ec761448d 100644
--- a/erts/emulator/zlib/deflate.c
+++ b/erts/emulator/zlib/deflate.c
@@ -1,5 +1,5 @@
 /* deflate.c -- compress data using the deflation algorithm
- * Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
+ * Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -49,13 +49,10 @@
 
 /* @(#) $Id$ */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
 #include "deflate.h"
 
 const char deflate_copyright[] =
-   " deflate 1.2.8 Copyright 1995-2013 Jean-loup Gailly and Mark Adler ";
+   " deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";
 /*
   If you use the zlib library in a product, an acknowledgment is welcome
   in the documentation of your product. If for some reason you cannot
@@ -76,6 +73,8 @@ typedef enum {
 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
 /* Compression function. Returns the block state after the call. */
 
+local int deflateStateCheck      OF((z_streamp strm));
+local void slide_hash     OF((deflate_state *s));
 local void fill_window    OF((deflate_state *s));
 local block_state deflate_stored OF((deflate_state *s, int flush));
 local block_state deflate_fast   OF((deflate_state *s, int flush));
@@ -87,15 +86,16 @@ local block_state deflate_huff   OF((deflate_state *s, int flush));
 local void lm_init        OF((deflate_state *s));
 local void putShortMSB    OF((deflate_state *s, uInt b));
 local void flush_pending  OF((z_streamp strm));
-local int read_buf        OF((z_streamp strm, Bytef *buf, unsigned size));
+local unsigned read_buf   OF((z_streamp strm, Bytef *buf, unsigned size));
 #ifdef ASMV
+#  pragma message("Assembler code may have bugs -- use at your own risk")
       void match_init OF((void)); /* asm code initialization */
       uInt longest_match  OF((deflate_state *s, IPos cur_match));
 #else
 local uInt longest_match  OF((deflate_state *s, IPos cur_match));
 #endif
 
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
 local  void check_match OF((deflate_state *s, IPos start, IPos match,
                             int length));
 #endif
@@ -151,21 +151,14 @@ local const config configuration_table[10] = {
  * meaning.
  */
 
-#define EQUAL 0
-/* result of memcmp for equal strings */
-
-#ifndef NO_DUMMY_DECL
-struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
-#endif
-
 /* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
-#define RANK(f) (((f) << 1) - ((f) > 4 ? 9 : 0))
+#define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0))
 
 /* ===========================================================================
  * Update a hash value with the given input byte
- * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
- *    input characters, so that a running hash key can be computed from the
- *    previous key instead of complete recalculation each time.
+ * IN  assertion: all calls to UPDATE_HASH are made with consecutive input
+ *    characters, so that a running hash key can be computed from the previous
+ *    key instead of complete recalculation each time.
  */
 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
 
@@ -176,9 +169,9 @@ struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
  * the previous length of the hash chain.
  * If this file is compiled with -DFASTEST, the compression level is forced
  * to 1, and no hash chains are maintained.
- * IN  assertion: all calls to to INSERT_STRING are made with consecutive
- *    input characters and the first MIN_MATCH bytes of str are valid
- *    (except for the last MIN_MATCH-1 bytes of the input file).
+ * IN  assertion: all calls to INSERT_STRING are made with consecutive input
+ *    characters and the first MIN_MATCH bytes of str are valid (except for
+ *    the last MIN_MATCH-1 bytes of the input file).
  */
 #ifdef FASTEST
 #define INSERT_STRING(s, str, match_head) \
@@ -200,6 +193,37 @@ struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
     s->head[s->hash_size-1] = NIL; \
     zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
 
+/* ===========================================================================
+ * Slide the hash table when sliding the window down (could be avoided with 32
+ * bit values at the expense of memory usage). We slide even when level == 0 to
+ * keep the hash table consistent if we switch back to level > 0 later.
+ */
+local void slide_hash(s)
+    deflate_state *s;
+{
+    unsigned n, m;
+    Posf *p;
+    uInt wsize = s->w_size;
+
+    n = s->hash_size;
+    p = &s->head[n];
+    do {
+        m = *--p;
+        *p = (Pos)(m >= wsize ? m - wsize : NIL);
+    } while (--n);
+    n = wsize;
+#ifndef FASTEST
+    p = &s->prev[n];
+    do {
+        m = *--p;
+        *p = (Pos)(m >= wsize ? m - wsize : NIL);
+        /* If n is not on any hash chain, prev[n] is garbage but
+         * its value will never be used.
+         */
+    } while (--n);
+#endif
+}
+
 /* ========================================================================= */
 int ZEXPORT deflateInit_(strm, level, version, stream_size)
     z_streamp strm;
@@ -273,7 +297,7 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
 #endif
     if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
         windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
-        strategy < 0 || strategy > Z_FIXED) {
+        strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) {
         return Z_STREAM_ERROR;
     }
     if (windowBits == 8) windowBits = 9;  /* until 256-byte window bug fixed */
@@ -281,14 +305,15 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
     if (s == Z_NULL) return Z_MEM_ERROR;
     strm->state = (struct internal_state FAR *)s;
     s->strm = strm;
+    s->status = INIT_STATE;     /* to pass state test in deflateReset() */
 
     s->wrap = wrap;
     s->gzhead = Z_NULL;
-    s->w_bits = windowBits;
+    s->w_bits = (uInt)windowBits;
     s->w_size = 1 << s->w_bits;
     s->w_mask = s->w_size - 1;
 
-    s->hash_bits = memLevel + 7;
+    s->hash_bits = (uInt)memLevel + 7;
     s->hash_size = 1 << s->hash_bits;
     s->hash_mask = s->hash_size - 1;
     s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
@@ -322,6 +347,31 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
     return deflateReset(strm);
 }
 
+/* =========================================================================
+ * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
+ */
+local int deflateStateCheck (strm)
+    z_streamp strm;
+{
+    deflate_state *s;
+    if (strm == Z_NULL ||
+        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
+        return 1;
+    s = strm->state;
+    if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
+#ifdef GZIP
+                                           s->status != GZIP_STATE &&
+#endif
+                                           s->status != EXTRA_STATE &&
+                                           s->status != NAME_STATE &&
+                                           s->status != COMMENT_STATE &&
+                                           s->status != HCRC_STATE &&
+                                           s->status != BUSY_STATE &&
+                                           s->status != FINISH_STATE))
+        return 1;
+    return 0;
+}
+
 /* ========================================================================= */
 int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
     z_streamp strm;
@@ -334,7 +384,7 @@ int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
     unsigned avail;
     z_const unsigned char *next;
 
-    if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
+    if (deflateStateCheck(strm) || dictionary == Z_NULL)
         return Z_STREAM_ERROR;
     s = strm->state;
     wrap = s->wrap;
@@ -392,13 +442,34 @@ int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
 }
 
 /* ========================================================================= */
+int ZEXPORT deflateGetDictionary (strm, dictionary, dictLength)
+    z_streamp strm;
+    Bytef *dictionary;
+    uInt  *dictLength;
+{
+    deflate_state *s;
+    uInt len;
+
+    if (deflateStateCheck(strm))
+        return Z_STREAM_ERROR;
+    s = strm->state;
+    len = s->strstart + s->lookahead;
+    if (len > s->w_size)
+        len = s->w_size;
+    if (dictionary != Z_NULL && len)
+        zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len);
+    if (dictLength != Z_NULL)
+        *dictLength = len;
+    return Z_OK;
+}
+
+/* ========================================================================= */
 int ZEXPORT deflateResetKeep (strm)
     z_streamp strm;
 {
     deflate_state *s;
 
-    if (strm == Z_NULL || strm->state == Z_NULL ||
-        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) {
+    if (deflateStateCheck(strm)) {
         return Z_STREAM_ERROR;
     }
 
@@ -413,7 +484,11 @@ int ZEXPORT deflateResetKeep (strm)
     if (s->wrap < 0) {
         s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
     }
-    s->status = s->wrap ? INIT_STATE : BUSY_STATE;
+    s->status =
+#ifdef GZIP
+        s->wrap == 2 ? GZIP_STATE :
+#endif
+        s->wrap ? INIT_STATE : BUSY_STATE;
     strm->adler =
 #ifdef GZIP
         s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
@@ -443,8 +518,8 @@ int ZEXPORT deflateSetHeader (strm, head)
     z_streamp strm;
     gz_headerp head;
 {
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
-    if (strm->state->wrap != 2) return Z_STREAM_ERROR;
+    if (deflateStateCheck(strm) || strm->state->wrap != 2)
+        return Z_STREAM_ERROR;
     strm->state->gzhead = head;
     return Z_OK;
 }
@@ -455,7 +530,7 @@ int ZEXPORT deflatePending (strm, pending, bits)
     int *bits;
     z_streamp strm;
 {
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
     if (pending != Z_NULL)
         *pending = strm->state->pending;
     if (bits != Z_NULL)
@@ -472,7 +547,7 @@ int ZEXPORT deflatePrime (strm, bits, value)
     deflate_state *s;
     int put;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
     s = strm->state;
     if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
         return Z_BUF_ERROR;
@@ -497,9 +572,8 @@ int ZEXPORT deflateParams(strm, level, strategy)
 {
     deflate_state *s;
     compress_func func;
-    int err = Z_OK;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
     s = strm->state;
 
 #ifdef FASTEST
@@ -513,13 +587,22 @@ int ZEXPORT deflateParams(strm, level, strategy)
     func = configuration_table[s->level].func;
 
     if ((strategy != s->strategy || func != configuration_table[level].func) &&
-        strm->total_in != 0) {
+        s->high_water) {
         /* Flush the last buffer: */
-        err = deflate(strm, Z_BLOCK);
-        if (err == Z_BUF_ERROR && s->pending == 0)
-            err = Z_OK;
+        int err = deflate(strm, Z_BLOCK);
+        if (err == Z_STREAM_ERROR)
+            return err;
+        if (strm->avail_out == 0)
+            return Z_BUF_ERROR;
     }
     if (s->level != level) {
+        if (s->level == 0 && s->matches != 0) {
+            if (s->matches == 1)
+                slide_hash(s);
+            else
+                CLEAR_HASH(s);
+            s->matches = 0;
+        }
         s->level = level;
         s->max_lazy_match   = configuration_table[level].max_lazy;
         s->good_match       = configuration_table[level].good_length;
@@ -527,7 +610,7 @@ int ZEXPORT deflateParams(strm, level, strategy)
         s->max_chain_length = configuration_table[level].max_chain;
     }
     s->strategy = strategy;
-    return err;
+    return Z_OK;
 }
 
 /* ========================================================================= */
@@ -540,12 +623,12 @@ int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
 {
     deflate_state *s;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
     s = strm->state;
-    s->good_match = good_length;
-    s->max_lazy_match = max_lazy;
+    s->good_match = (uInt)good_length;
+    s->max_lazy_match = (uInt)max_lazy;
     s->nice_match = nice_length;
-    s->max_chain_length = max_chain;
+    s->max_chain_length = (uInt)max_chain;
     return Z_OK;
 }
 
@@ -572,14 +655,13 @@ uLong ZEXPORT deflateBound(strm, sourceLen)
 {
     deflate_state *s;
     uLong complen, wraplen;
-    Bytef *str;
 
     /* conservative upper bound for compressed data */
     complen = sourceLen +
               ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
 
     /* if can't get parameters, return conservative bound plus zlib wrapper */
-    if (strm == Z_NULL || strm->state == Z_NULL)
+    if (deflateStateCheck(strm))
         return complen + 6;
 
     /* compute wrapper length */
@@ -591,9 +673,11 @@ uLong ZEXPORT deflateBound(strm, sourceLen)
     case 1:                                 /* zlib wrapper */
         wraplen = 6 + (s->strstart ? 4 : 0);
         break;
+#ifdef GZIP
     case 2:                                 /* gzip wrapper */
         wraplen = 18;
         if (s->gzhead != Z_NULL) {          /* user-supplied gzip header */
+            Bytef *str;
             if (s->gzhead->extra != Z_NULL)
                 wraplen += 2 + s->gzhead->extra_len;
             str = s->gzhead->name;
@@ -610,6 +694,7 @@ uLong ZEXPORT deflateBound(strm, sourceLen)
                 wraplen += 2;
         }
         break;
+#endif
     default:                                /* for compiler happiness */
         wraplen = 6;
     }
@@ -637,10 +722,10 @@ local void putShortMSB (s, b)
 }
 
 /* =========================================================================
- * Flush as much pending output as possible. All deflate() output goes
- * through this function so some applications may wish to modify it
- * to avoid allocating a large strm->next_out buffer and copying into it.
- * (See also read_buf()).
+ * Flush as much pending output as possible. All deflate() output, except for
+ * some deflate_stored() output, goes through this function so some
+ * applications may wish to modify it to avoid allocating a large
+ * strm->next_out buffer and copying into it. (See also read_buf()).
  */
 local void flush_pending(strm)
     z_streamp strm;
@@ -657,13 +742,23 @@ local void flush_pending(strm)
     strm->next_out  += len;
     s->pending_out  += len;
     strm->total_out += len;
-    strm->avail_out  -= len;
-    s->pending -= len;
+    strm->avail_out -= len;
+    s->pending      -= len;
     if (s->pending == 0) {
         s->pending_out = s->pending_buf;
     }
 }
 
+/* ===========================================================================
+ * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1].
+ */
+#define HCRC_UPDATE(beg) \
+    do { \
+        if (s->gzhead->hcrc && s->pending > (beg)) \
+            strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
+                                s->pending - (beg)); \
+    } while (0)
+
 /* ========================================================================= */
 int ZEXPORT deflate (strm, flush)
     z_streamp strm;
@@ -672,230 +767,229 @@ int ZEXPORT deflate (strm, flush)
     int old_flush; /* value of flush param for previous deflate call */
     deflate_state *s;
 
-    if (strm == Z_NULL || strm->state == Z_NULL ||
-        flush > Z_BLOCK || flush < 0) {
+    if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) {
         return Z_STREAM_ERROR;
     }
     s = strm->state;
 
     if (strm->next_out == Z_NULL ||
-        (strm->next_in == Z_NULL && strm->avail_in != 0) ||
+        (strm->avail_in != 0 && strm->next_in == Z_NULL) ||
         (s->status == FINISH_STATE && flush != Z_FINISH)) {
         ERR_RETURN(strm, Z_STREAM_ERROR);
     }
     if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
 
-    s->strm = strm; /* just in case */
     old_flush = s->last_flush;
     s->last_flush = flush;
 
+    /* Flush as much pending output as possible */
+    if (s->pending != 0) {
+        flush_pending(strm);
+        if (strm->avail_out == 0) {
+            /* Since avail_out is 0, deflate will be called again with
+             * more output space, but possibly with both pending and
+             * avail_in equal to zero. There won't be anything to do,
+             * but this is not an error situation so make sure we
+             * return OK instead of BUF_ERROR at next call of deflate:
+             */
+            s->last_flush = -1;
+            return Z_OK;
+        }
+
+    /* Make sure there is something to do and avoid duplicate consecutive
+     * flushes. For repeated and useless calls with Z_FINISH, we keep
+     * returning Z_STREAM_END instead of Z_BUF_ERROR.
+     */
+    } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
+               flush != Z_FINISH) {
+        ERR_RETURN(strm, Z_BUF_ERROR);
+    }
+
+    /* User must not provide more input after the first FINISH: */
+    if (s->status == FINISH_STATE && strm->avail_in != 0) {
+        ERR_RETURN(strm, Z_BUF_ERROR);
+    }
+
     /* Write the header */
     if (s->status == INIT_STATE) {
-#ifdef GZIP
-        if (s->wrap == 2) {
-            strm->adler = crc32(0L, Z_NULL, 0);
-            put_byte(s, 31);
-            put_byte(s, 139);
-            put_byte(s, 8);
-            if (s->gzhead == Z_NULL) {
-                put_byte(s, 0);
-                put_byte(s, 0);
-                put_byte(s, 0);
-                put_byte(s, 0);
-                put_byte(s, 0);
-                put_byte(s, s->level == 9 ? 2 :
-                            (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
-                             4 : 0));
-                put_byte(s, OS_CODE);
-                s->status = BUSY_STATE;
-            }
-            else {
-                put_byte(s, (s->gzhead->text ? 1 : 0) +
-                            (s->gzhead->hcrc ? 2 : 0) +
-                            (s->gzhead->extra == Z_NULL ? 0 : 4) +
-                            (s->gzhead->name == Z_NULL ? 0 : 8) +
-                            (s->gzhead->comment == Z_NULL ? 0 : 16)
-                        );
-                put_byte(s, (Byte)(s->gzhead->time & 0xff));
-                put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
-                put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
-                put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
-                put_byte(s, s->level == 9 ? 2 :
-                            (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
-                             4 : 0));
-                put_byte(s, s->gzhead->os & 0xff);
-                if (s->gzhead->extra != Z_NULL) {
-                    put_byte(s, s->gzhead->extra_len & 0xff);
-                    put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
-                }
-                if (s->gzhead->hcrc)
-                    strm->adler = crc32(strm->adler, s->pending_buf,
-                                        s->pending);
-                s->gzindex = 0;
-                s->status = EXTRA_STATE;
-            }
-        }
+        /* zlib header */
+        uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
+        uInt level_flags;
+
+        if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
+            level_flags = 0;
+        else if (s->level < 6)
+            level_flags = 1;
+        else if (s->level == 6)
+            level_flags = 2;
         else
-#endif
-        {
-            uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
-            uInt level_flags;
-
-            if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
-                level_flags = 0;
-            else if (s->level < 6)
-                level_flags = 1;
-            else if (s->level == 6)
-                level_flags = 2;
-            else
-                level_flags = 3;
-            header |= (level_flags << 6);
-            if (s->strstart != 0) header |= PRESET_DICT;
-            header += 31 - (header % 31);
+            level_flags = 3;
+        header |= (level_flags << 6);
+        if (s->strstart != 0) header |= PRESET_DICT;
+        header += 31 - (header % 31);
+
+        putShortMSB(s, header);
+
+        /* Save the adler32 of the preset dictionary: */
+        if (s->strstart != 0) {
+            putShortMSB(s, (uInt)(strm->adler >> 16));
+            putShortMSB(s, (uInt)(strm->adler & 0xffff));
+        }
+        strm->adler = adler32(0L, Z_NULL, 0);
+        s->status = BUSY_STATE;
 
+        /* Compression must start with an empty pending buffer */
+        flush_pending(strm);
+        if (s->pending != 0) {
+            s->last_flush = -1;
+            return Z_OK;
+        }
+    }
+#ifdef GZIP
+    if (s->status == GZIP_STATE) {
+        /* gzip header */
+        strm->adler = crc32(0L, Z_NULL, 0);
+        put_byte(s, 31);
+        put_byte(s, 139);
+        put_byte(s, 8);
+        if (s->gzhead == Z_NULL) {
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, s->level == 9 ? 2 :
+                     (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
+                      4 : 0));
+            put_byte(s, OS_CODE);
             s->status = BUSY_STATE;
-            putShortMSB(s, header);
 
-            /* Save the adler32 of the preset dictionary: */
-            if (s->strstart != 0) {
-                putShortMSB(s, (uInt)(strm->adler >> 16));
-                putShortMSB(s, (uInt)(strm->adler & 0xffff));
+            /* Compression must start with an empty pending buffer */
+            flush_pending(strm);
+            if (s->pending != 0) {
+                s->last_flush = -1;
+                return Z_OK;
+            }
+        }
+        else {
+            put_byte(s, (s->gzhead->text ? 1 : 0) +
+                     (s->gzhead->hcrc ? 2 : 0) +
+                     (s->gzhead->extra == Z_NULL ? 0 : 4) +
+                     (s->gzhead->name == Z_NULL ? 0 : 8) +
+                     (s->gzhead->comment == Z_NULL ? 0 : 16)
+                     );
+            put_byte(s, (Byte)(s->gzhead->time & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
+            put_byte(s, s->level == 9 ? 2 :
+                     (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
+                      4 : 0));
+            put_byte(s, s->gzhead->os & 0xff);
+            if (s->gzhead->extra != Z_NULL) {
+                put_byte(s, s->gzhead->extra_len & 0xff);
+                put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
             }
-            strm->adler = adler32(0L, Z_NULL, 0);
+            if (s->gzhead->hcrc)
+                strm->adler = crc32(strm->adler, s->pending_buf,
+                                    s->pending);
+            s->gzindex = 0;
+            s->status = EXTRA_STATE;
         }
     }
-#ifdef GZIP
     if (s->status == EXTRA_STATE) {
         if (s->gzhead->extra != Z_NULL) {
-            uInt beg = s->pending;  /* start of bytes to update crc */
-
-            while (s->gzindex < (s->gzhead->extra_len & 0xffff)) {
-                if (s->pending == s->pending_buf_size) {
-                    if (s->gzhead->hcrc && s->pending > beg)
-                        strm->adler = crc32(strm->adler, s->pending_buf + beg,
-                                            s->pending - beg);
-                    flush_pending(strm);
-                    beg = s->pending;
-                    if (s->pending == s->pending_buf_size)
-                        break;
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex;
+            while (s->pending + left > s->pending_buf_size) {
+                uInt copy = s->pending_buf_size - s->pending;
+                zmemcpy(s->pending_buf + s->pending,
+                        s->gzhead->extra + s->gzindex, copy);
+                s->pending = s->pending_buf_size;
+                HCRC_UPDATE(beg);
+                s->gzindex += copy;
+                flush_pending(strm);
+                if (s->pending != 0) {
+                    s->last_flush = -1;
+                    return Z_OK;
                 }
-                put_byte(s, s->gzhead->extra[s->gzindex]);
-                s->gzindex++;
-            }
-            if (s->gzhead->hcrc && s->pending > beg)
-                strm->adler = crc32(strm->adler, s->pending_buf + beg,
-                                    s->pending - beg);
-            if (s->gzindex == s->gzhead->extra_len) {
-                s->gzindex = 0;
-                s->status = NAME_STATE;
+                beg = 0;
+                left -= copy;
             }
+            zmemcpy(s->pending_buf + s->pending,
+                    s->gzhead->extra + s->gzindex, left);
+            s->pending += left;
+            HCRC_UPDATE(beg);
+            s->gzindex = 0;
         }
-        else
-            s->status = NAME_STATE;
+        s->status = NAME_STATE;
     }
     if (s->status == NAME_STATE) {
         if (s->gzhead->name != Z_NULL) {
-            uInt beg = s->pending;  /* start of bytes to update crc */
+            ulg beg = s->pending;   /* start of bytes to update crc */
             int val;
-
             do {
                 if (s->pending == s->pending_buf_size) {
-                    if (s->gzhead->hcrc && s->pending > beg)
-                        strm->adler = crc32(strm->adler, s->pending_buf + beg,
-                                            s->pending - beg);
+                    HCRC_UPDATE(beg);
                     flush_pending(strm);
-                    beg = s->pending;
-                    if (s->pending == s->pending_buf_size) {
-                        val = 1;
-                        break;
+                    if (s->pending != 0) {
+                        s->last_flush = -1;
+                        return Z_OK;
                     }
+                    beg = 0;
                 }
                 val = s->gzhead->name[s->gzindex++];
                 put_byte(s, val);
             } while (val != 0);
-            if (s->gzhead->hcrc && s->pending > beg)
-                strm->adler = crc32(strm->adler, s->pending_buf + beg,
-                                    s->pending - beg);
-            if (val == 0) {
-                s->gzindex = 0;
-                s->status = COMMENT_STATE;
-            }
+            HCRC_UPDATE(beg);
+            s->gzindex = 0;
         }
-        else
-            s->status = COMMENT_STATE;
+        s->status = COMMENT_STATE;
     }
     if (s->status == COMMENT_STATE) {
         if (s->gzhead->comment != Z_NULL) {
-            uInt beg = s->pending;  /* start of bytes to update crc */
+            ulg beg = s->pending;   /* start of bytes to update crc */
             int val;
-
             do {
                 if (s->pending == s->pending_buf_size) {
-                    if (s->gzhead->hcrc && s->pending > beg)
-                        strm->adler = crc32(strm->adler, s->pending_buf + beg,
-                                            s->pending - beg);
+                    HCRC_UPDATE(beg);
                     flush_pending(strm);
-                    beg = s->pending;
-                    if (s->pending == s->pending_buf_size) {
-                        val = 1;
-                        break;
+                    if (s->pending != 0) {
+                        s->last_flush = -1;
+                        return Z_OK;
                     }
+                    beg = 0;
                 }
                 val = s->gzhead->comment[s->gzindex++];
                 put_byte(s, val);
             } while (val != 0);
-            if (s->gzhead->hcrc && s->pending > beg)
-                strm->adler = crc32(strm->adler, s->pending_buf + beg,
-                                    s->pending - beg);
-            if (val == 0)
-                s->status = HCRC_STATE;
+            HCRC_UPDATE(beg);
         }
-        else
-            s->status = HCRC_STATE;
+        s->status = HCRC_STATE;
     }
     if (s->status == HCRC_STATE) {
         if (s->gzhead->hcrc) {
-            if (s->pending + 2 > s->pending_buf_size)
+            if (s->pending + 2 > s->pending_buf_size) {
                 flush_pending(strm);
-            if (s->pending + 2 <= s->pending_buf_size) {
-                put_byte(s, (Byte)(strm->adler & 0xff));
-                put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
-                strm->adler = crc32(0L, Z_NULL, 0);
-                s->status = BUSY_STATE;
+                if (s->pending != 0) {
+                    s->last_flush = -1;
+                    return Z_OK;
+                }
             }
+            put_byte(s, (Byte)(strm->adler & 0xff));
+            put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
+            strm->adler = crc32(0L, Z_NULL, 0);
         }
-        else
-            s->status = BUSY_STATE;
-    }
-#endif
+        s->status = BUSY_STATE;
 
-    /* Flush as much pending output as possible */
-    if (s->pending != 0) {
+        /* Compression must start with an empty pending buffer */
         flush_pending(strm);
-        if (strm->avail_out == 0) {
-            /* Since avail_out is 0, deflate will be called again with
-             * more output space, but possibly with both pending and
-             * avail_in equal to zero. There won't be anything to do,
-             * but this is not an error situation so make sure we
-             * return OK instead of BUF_ERROR at next call of deflate:
-             */
+        if (s->pending != 0) {
             s->last_flush = -1;
             return Z_OK;
         }
-
-    /* Make sure there is something to do and avoid duplicate consecutive
-     * flushes. For repeated and useless calls with Z_FINISH, we keep
-     * returning Z_STREAM_END instead of Z_BUF_ERROR.
-     */
-    } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
-               flush != Z_FINISH) {
-        ERR_RETURN(strm, Z_BUF_ERROR);
-    }
-
-    /* User must not provide more input after the first FINISH: */
-    if (s->status == FINISH_STATE && strm->avail_in != 0) {
-        ERR_RETURN(strm, Z_BUF_ERROR);
     }
+#endif
 
     /* Start a new block or continue the current one.
      */
@@ -903,9 +997,10 @@ int ZEXPORT deflate (strm, flush)
         (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
         block_state bstate;
 
-        bstate = s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
-                    (s->strategy == Z_RLE ? deflate_rle(s, flush) :
-                        (*(configuration_table[s->level].func))(s, flush));
+        bstate = s->level == 0 ? deflate_stored(s, flush) :
+                 s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
+                 s->strategy == Z_RLE ? deflate_rle(s, flush) :
+                 (*(configuration_table[s->level].func))(s, flush);
 
         if (bstate == finish_started || bstate == finish_done) {
             s->status = FINISH_STATE;
@@ -947,7 +1042,6 @@ int ZEXPORT deflate (strm, flush)
             }
         }
     }
-    Assert(strm->avail_out > 0, "bug2");
 
     if (flush != Z_FINISH) return Z_OK;
     if (s->wrap <= 0) return Z_STREAM_END;
@@ -984,18 +1078,9 @@ int ZEXPORT deflateEnd (strm)
 {
     int status;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
 
     status = strm->state->status;
-    if (status != INIT_STATE &&
-        status != EXTRA_STATE &&
-        status != NAME_STATE &&
-        status != COMMENT_STATE &&
-        status != HCRC_STATE &&
-        status != BUSY_STATE &&
-        status != FINISH_STATE) {
-      return Z_STREAM_ERROR;
-    }
 
     /* Deallocate in reverse order of allocations: */
     TRY_FREE(strm, strm->state->pending_buf);
@@ -1026,7 +1111,7 @@ int ZEXPORT deflateCopy (dest, source)
     ushf *overlay;
 
 
-    if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
+    if (deflateStateCheck(source) || dest == Z_NULL) {
         return Z_STREAM_ERROR;
     }
 
@@ -1076,7 +1161,7 @@ int ZEXPORT deflateCopy (dest, source)
  * allocating a large strm->next_in buffer and copying from it.
  * (See also flush_pending()).
  */
-local int read_buf(strm, buf, size)
+local unsigned read_buf(strm, buf, size)
     z_streamp strm;
     Bytef *buf;
     unsigned size;
@@ -1100,7 +1185,7 @@ local int read_buf(strm, buf, size)
     strm->next_in  += len;
     strm->total_in += len;
 
-    return (int)len;
+    return len;
 }
 
 /* ===========================================================================
@@ -1154,9 +1239,9 @@ local uInt longest_match(s, cur_match)
 {
     unsigned chain_length = s->max_chain_length;/* max hash chain length */
     register Bytef *scan = s->window + s->strstart; /* current string */
-    register Bytef *match;                       /* matched string */
+    register Bytef *match;                      /* matched string */
     register int len;                           /* length of current match */
-    int best_len = s->prev_length;              /* best match length so far */
+    int best_len = (int)s->prev_length;         /* best match length so far */
     int nice_match = s->nice_match;             /* stop if match long enough */
     IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
         s->strstart - (IPos)MAX_DIST(s) : NIL;
@@ -1191,7 +1276,7 @@ local uInt longest_match(s, cur_match)
     /* Do not look for matches beyond the end of the input. This is necessary
      * to make deflate deterministic.
      */
-    if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
+    if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
 
     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
 
@@ -1352,7 +1437,11 @@ local uInt longest_match(s, cur_match)
 
 #endif /* FASTEST */
 
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
+
+#define EQUAL 0
+/* result of memcmp for equal strings */
+
 /* ===========================================================================
  * Check that the match at match_start is indeed a match.
  */
@@ -1378,7 +1467,7 @@ local void check_match(s, start, match, length)
 }
 #else
 #  define check_match(s, start, match, length)
-#endif /* DEBUG */
+#endif /* ZLIB_DEBUG */
 
 /* ===========================================================================
  * Fill the window when the lookahead becomes insufficient.
@@ -1393,8 +1482,7 @@ local void check_match(s, start, match, length)
 local void fill_window(s)
     deflate_state *s;
 {
-    register unsigned n, m;
-    register Posf *p;
+    unsigned n;
     unsigned more;    /* Amount of free space at the end of the window. */
     uInt wsize = s->w_size;
 
@@ -1421,35 +1509,11 @@ local void fill_window(s)
          */
         if (s->strstart >= wsize+MAX_DIST(s)) {
 
-            zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
+            zmemcpy(s->window, s->window+wsize, (unsigned)wsize - more);
             s->match_start -= wsize;
             s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
             s->block_start -= (long) wsize;
-
-            /* Slide the hash table (could be avoided with 32 bit values
-               at the expense of memory usage). We slide even when level == 0
-               to keep the hash table consistent if we switch back to level > 0
-               later. (Using level 0 permanently is not an optimal usage of
-               zlib, so we don't care about this pathological case.)
-             */
-            n = s->hash_size;
-            p = &s->head[n];
-            do {
-                m = *--p;
-                *p = (Pos)(m >= wsize ? m-wsize : NIL);
-            } while (--n);
-
-            n = wsize;
-#ifndef FASTEST
-            p = &s->prev[n];
-            do {
-                m = *--p;
-                *p = (Pos)(m >= wsize ? m-wsize : NIL);
-                /* If n is not on any hash chain, prev[n] is garbage but
-                 * its value will never be used.
-                 */
-            } while (--n);
-#endif
+            slide_hash(s);
             more += wsize;
         }
         if (s->strm->avail_in == 0) break;
@@ -1555,70 +1619,199 @@ local void fill_window(s)
    if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
 }
 
+/* Maximum stored block length in deflate format (not including header). */
+#define MAX_STORED 65535
+
+/* Minimum of a and b. */
+#define MIN(a, b) ((a) > (b) ? (b) : (a))
+
 /* ===========================================================================
  * Copy without compression as much as possible from the input stream, return
  * the current block state.
- * This function does not insert new strings in the dictionary since
- * uncompressible data is probably not useful. This function is used
- * only for the level=0 compression option.
- * NOTE: this function should be optimized to avoid extra copying from
- * window to pending_buf.
+ *
+ * In case deflateParams() is used to later switch to a non-zero compression
+ * level, s->matches (otherwise unused when storing) keeps track of the number
+ * of hash table slides to perform. If s->matches is 1, then one hash table
+ * slide will be done when switching. If s->matches is 2, the maximum value
+ * allowed here, then the hash table will be cleared, since two or more slides
+ * is the same as a clear.
+ *
+ * deflate_stored() is written to minimize the number of times an input byte is
+ * copied. It is most efficient with large input and output buffers, which
+ * maximizes the opportunites to have a single copy from next_in to next_out.
  */
 local block_state deflate_stored(s, flush)
     deflate_state *s;
     int flush;
 {
-    /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
-     * to pending_buf_size, and each stored block has a 5 byte header:
+    /* Smallest worthy block size when not flushing or finishing. By default
+     * this is 32K. This can be as small as 507 bytes for memLevel == 1. For
+     * large input and output buffers, the stored block size will be larger.
      */
-    ulg max_block_size = 0xffff;
-    ulg max_start;
-
-    if (max_block_size > s->pending_buf_size - 5) {
-        max_block_size = s->pending_buf_size - 5;
-    }
-
-    /* Copy as much as possible from input to output: */
-    for (;;) {
-        /* Fill the window as much as possible: */
-        if (s->lookahead <= 1) {
+    unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);
 
-            Assert(s->strstart < s->w_size+MAX_DIST(s) ||
-                   s->block_start >= (long)s->w_size, "slide too late");
+    /* Copy as many min_block or larger stored blocks directly to next_out as
+     * possible. If flushing, copy the remaining available input to next_out as
+     * stored blocks, if there is enough space.
+     */
+    unsigned len, left, have, last = 0;
+    unsigned used = s->strm->avail_in;
+    do {
+        /* Set len to the maximum size block that we can copy directly with the
+         * available input data and output space. Set left to how much of that
+         * would be copied from what's left in the window.
+         */
+        len = MAX_STORED;       /* maximum deflate stored block length */
+        have = (s->bi_valid + 42) >> 3;         /* number of header bytes */
+        if (s->strm->avail_out < have)          /* need room for header */
+            break;
+            /* maximum stored block length that will fit in avail_out: */
+        have = s->strm->avail_out - have;
+        left = s->strstart - s->block_start;    /* bytes left in window */
+        if (len > (ulg)left + s->strm->avail_in)
+            len = left + s->strm->avail_in;     /* limit len to the input */
+        if (len > have)
+            len = have;                         /* limit len to the output */
+
+        /* If the stored block would be less than min_block in length, or if
+         * unable to copy all of the available input when flushing, then try
+         * copying to the window and the pending buffer instead. Also don't
+         * write an empty block when flushing -- deflate() does that.
+         */
+        if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
+                                flush == Z_NO_FLUSH ||
+                                len != left + s->strm->avail_in))
+            break;
 
-            fill_window(s);
-            if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
+        /* Make a dummy stored block in pending to get the header bytes,
+         * including any pending bits. This also updates the debugging counts.
+         */
+        last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0;
+        _tr_stored_block(s, (char *)0, 0L, last);
+
+        /* Replace the lengths in the dummy stored block with len. */
+        s->pending_buf[s->pending - 4] = len;
+        s->pending_buf[s->pending - 3] = len >> 8;
+        s->pending_buf[s->pending - 2] = ~len;
+        s->pending_buf[s->pending - 1] = ~len >> 8;
+
+        /* Write the stored block header bytes. */
+        flush_pending(s->strm);
+
+#ifdef ZLIB_DEBUG
+        /* Update debugging counts for the data about to be copied. */
+        s->compressed_len += len << 3;
+        s->bits_sent += len << 3;
+#endif
 
-            if (s->lookahead == 0) break; /* flush the current block */
+        /* Copy uncompressed bytes from the window to next_out. */
+        if (left) {
+            if (left > len)
+                left = len;
+            zmemcpy(s->strm->next_out, s->window + s->block_start, left);
+            s->strm->next_out += left;
+            s->strm->avail_out -= left;
+            s->strm->total_out += left;
+            s->block_start += left;
+            len -= left;
         }
-        Assert(s->block_start >= 0L, "block gone");
-
-        s->strstart += s->lookahead;
-        s->lookahead = 0;
-
-        /* Emit a stored block if pending_buf will be full: */
-        max_start = s->block_start + max_block_size;
-        if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
-            /* strstart == 0 is possible when wraparound on 16-bit machine */
-            s->lookahead = (uInt)(s->strstart - max_start);
-            s->strstart = (uInt)max_start;
-            FLUSH_BLOCK(s, 0);
+
+        /* Copy uncompressed bytes directly from next_in to next_out, updating
+         * the check value.
+         */
+        if (len) {
+            read_buf(s->strm, s->strm->next_out, len);
+            s->strm->next_out += len;
+            s->strm->avail_out -= len;
+            s->strm->total_out += len;
         }
-        /* Flush if we may have to slide, otherwise block_start may become
-         * negative and the data will be gone:
+    } while (last == 0);
+
+    /* Update the sliding window with the last s->w_size bytes of the copied
+     * data, or append all of the copied data to the existing window if less
+     * than s->w_size bytes were copied. Also update the number of bytes to
+     * insert in the hash tables, in the event that deflateParams() switches to
+     * a non-zero compression level.
+     */
+    used -= s->strm->avail_in;      /* number of input bytes directly copied */
+    if (used) {
+        /* If any input was used, then no unused input remains in the window,
+         * therefore s->block_start == s->strstart.
          */
-        if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
-            FLUSH_BLOCK(s, 0);
+        if (used >= s->w_size) {    /* supplant the previous history */
+            s->matches = 2;         /* clear hash */
+            zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
+            s->strstart = s->w_size;
         }
+        else {
+            if (s->window_size - s->strstart <= used) {
+                /* Slide the window down. */
+                s->strstart -= s->w_size;
+                zmemcpy(s->window, s->window + s->w_size, s->strstart);
+                if (s->matches < 2)
+                    s->matches++;   /* add a pending slide_hash() */
+            }
+            zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
+            s->strstart += used;
+        }
+        s->block_start = s->strstart;
+        s->insert += MIN(used, s->w_size - s->insert);
     }
-    s->insert = 0;
-    if (flush == Z_FINISH) {
-        FLUSH_BLOCK(s, 1);
+    if (s->high_water < s->strstart)
+        s->high_water = s->strstart;
+
+    /* If the last block was written to next_out, then done. */
+    if (last)
         return finish_done;
+
+    /* If flushing and all input has been consumed, then done. */
+    if (flush != Z_NO_FLUSH && flush != Z_FINISH &&
+        s->strm->avail_in == 0 && (long)s->strstart == s->block_start)
+        return block_done;
+
+    /* Fill the window with any remaining input. */
+    have = s->window_size - s->strstart - 1;
+    if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) {
+        /* Slide the window down. */
+        s->block_start -= s->w_size;
+        s->strstart -= s->w_size;
+        zmemcpy(s->window, s->window + s->w_size, s->strstart);
+        if (s->matches < 2)
+            s->matches++;           /* add a pending slide_hash() */
+        have += s->w_size;          /* more space now */
     }
-    if ((long)s->strstart > s->block_start)
-        FLUSH_BLOCK(s, 0);
-    return block_done;
+    if (have > s->strm->avail_in)
+        have = s->strm->avail_in;
+    if (have) {
+        read_buf(s->strm, s->window + s->strstart, have);
+        s->strstart += have;
+    }
+    if (s->high_water < s->strstart)
+        s->high_water = s->strstart;
+
+    /* There was not enough avail_out to write a complete worthy or flushed
+     * stored block to next_out. Write a stored block to pending instead, if we
+     * have enough input for a worthy block, or if flushing and there is enough
+     * room for the remaining input as a stored block in the pending buffer.
+     */
+    have = (s->bi_valid + 42) >> 3;         /* number of header bytes */
+        /* maximum stored block length that will fit in pending: */
+    have = MIN(s->pending_buf_size - have, MAX_STORED);
+    min_block = MIN(have, s->w_size);
+    left = s->strstart - s->block_start;
+    if (left >= min_block ||
+        ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH &&
+         s->strm->avail_in == 0 && left <= have)) {
+        len = MIN(left, have);
+        last = flush == Z_FINISH && s->strm->avail_in == 0 &&
+               len == left ? 1 : 0;
+        _tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
+        s->block_start += len;
+        flush_pending(s->strm);
+    }
+
+    /* We've done all we can with the available input and output. */
+    return last ? finish_started : need_more;
 }
 
 /* ===========================================================================
@@ -1895,7 +2088,7 @@ local block_state deflate_rle(s, flush)
                          prev == *++scan && prev == *++scan &&
                          prev == *++scan && prev == *++scan &&
                          scan < strend);
-                s->match_length = MAX_MATCH - (int)(strend - scan);
+                s->match_length = MAX_MATCH - (uInt)(strend - scan);
                 if (s->match_length > s->lookahead)
                     s->match_length = s->lookahead;
             }
diff --git a/erts/emulator/zlib/deflate.h b/erts/emulator/zlib/deflate.h
index ce0299edd1..23ecdd312b 100644
--- a/erts/emulator/zlib/deflate.h
+++ b/erts/emulator/zlib/deflate.h
@@ -1,5 +1,5 @@
 /* deflate.h -- internal compression state
- * Copyright (C) 1995-2012 Jean-loup Gailly
+ * Copyright (C) 1995-2016 Jean-loup Gailly
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -51,13 +51,16 @@
 #define Buf_size 16
 /* size of bit buffer in bi_buf */
 
-#define INIT_STATE    42
-#define EXTRA_STATE   69
-#define NAME_STATE    73
-#define COMMENT_STATE 91
-#define HCRC_STATE   103
-#define BUSY_STATE   113
-#define FINISH_STATE 666
+#define INIT_STATE    42    /* zlib header -> BUSY_STATE */
+#ifdef GZIP
+#  define GZIP_STATE  57    /* gzip header -> BUSY_STATE | EXTRA_STATE */
+#endif
+#define EXTRA_STATE   69    /* gzip extra block -> NAME_STATE */
+#define NAME_STATE    73    /* gzip file name -> COMMENT_STATE */
+#define COMMENT_STATE 91    /* gzip comment -> HCRC_STATE */
+#define HCRC_STATE   103    /* gzip header CRC -> BUSY_STATE */
+#define BUSY_STATE   113    /* deflate -> FINISH_STATE */
+#define FINISH_STATE 666    /* stream complete */
 /* Stream status */
 
 
@@ -83,7 +86,7 @@ typedef struct static_tree_desc_s  static_tree_desc;
 typedef struct tree_desc_s {
     ct_data *dyn_tree;           /* the dynamic tree */
     int     max_code;            /* largest code with non zero frequency */
-    static_tree_desc *stat_desc; /* the corresponding static tree */
+    const static_tree_desc *stat_desc;  /* the corresponding static tree */
 } FAR tree_desc;
 
 typedef ush Pos;
@@ -100,10 +103,10 @@ typedef struct internal_state {
     Bytef *pending_buf;  /* output still pending */
     ulg   pending_buf_size; /* size of pending_buf */
     Bytef *pending_out;  /* next pending byte to output to the stream */
-    uInt   pending;      /* nb of bytes in the pending buffer */
+    ulg   pending;       /* nb of bytes in the pending buffer */
     int   wrap;          /* bit 0 true for zlib, bit 1 true for gzip */
     gz_headerp  gzhead;  /* gzip header information to write */
-    uInt   gzindex;      /* where in extra, name, or comment */
+    ulg   gzindex;       /* where in extra, name, or comment */
     Byte  method;        /* can only be DEFLATED */
     int   last_flush;    /* value of flush param for previous deflate call */
 
@@ -249,7 +252,7 @@ typedef struct internal_state {
     uInt matches;       /* number of string matches in current block */
     uInt insert;        /* bytes at end of window left to insert */
 
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
     ulg compressed_len; /* total bit length of compressed file mod 2^32 */
     ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
 #endif
@@ -275,7 +278,7 @@ typedef struct internal_state {
 /* Output a byte on the stream.
  * IN assertion: there is enough room in pending_buf.
  */
-#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
+#define put_byte(s, c) {s->pending_buf[s->pending++] = (Bytef)(c);}
 
 
 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
@@ -309,7 +312,7 @@ void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf,
  * used.
  */
 
-#ifndef DEBUG
+#ifndef ZLIB_DEBUG
 /* Inline versions of _tr_tally for speed: */
 
 #if defined(GEN_TREES_H) || !defined(STDC)
@@ -328,8 +331,8 @@ void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf,
     flush = (s->last_lit == s->lit_bufsize-1); \
    }
 # define _tr_tally_dist(s, distance, length, flush) \
-  { uch len = (length); \
-    ush dist = (distance); \
+  { uch len = (uch)(length); \
+    ush dist = (ush)(distance); \
     s->d_buf[s->last_lit] = dist; \
     s->l_buf[s->last_lit++] = len; \
     dist--; \
diff --git a/erts/emulator/zlib/gzguts.h b/erts/emulator/zlib/gzguts.h
index d87659d031..990a4d2514 100644
--- a/erts/emulator/zlib/gzguts.h
+++ b/erts/emulator/zlib/gzguts.h
@@ -1,5 +1,5 @@
 /* gzguts.h -- zlib internal header definitions for gz* operations
- * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013 Mark Adler
+ * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -25,6 +25,10 @@
 #  include <stdlib.h>
 #  include <limits.h>
 #endif
+
+#ifndef _POSIX_SOURCE
+#  define _POSIX_SOURCE
+#endif
 #include <fcntl.h>
 
 #ifdef _WIN32
@@ -35,6 +39,10 @@
 #  include <io.h>
 #endif
 
+#if defined(_WIN32) || defined(__CYGWIN__)
+#  define WIDECHAR
+#endif
+
 #ifdef WINAPI_FAMILY
 #  define open _open
 #  define read _read
@@ -95,18 +103,19 @@
 #  endif
 #endif
 
-/* unlike snprintf (which is required in C99, yet still not supported by
-   Microsoft more than a decade later!), _snprintf does not guarantee null
-   termination of the result -- however this is only used in gzlib.c where
+/* unlike snprintf (which is required in C99), _snprintf does not guarantee
+   null termination of the result -- however this is only used in gzlib.c where
    the result is assured to fit in the space provided */
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && _MSC_VER < 1900
 #  define snprintf _snprintf
 #endif
 
 #ifndef local
 #  define local static
 #endif
-/* compile with -Dlocal if your debugger can't find static symbols */
+/* since "static" is used to mean two completely different things in C, we
+   define "local" for the non-static meaning of "static", for readability
+   (compile with -Dlocal if your debugger can't find static symbols) */
 
 /* gz* functions always use library allocation functions */
 #ifndef STDC
@@ -170,7 +179,7 @@ typedef struct {
     char *path;             /* path or fd for error messages */
     unsigned size;          /* buffer size, zero if not allocated yet */
     unsigned want;          /* requested buffer size, default is GZBUFSIZE */
-    unsigned char *in;      /* input buffer */
+    unsigned char *in;      /* input buffer (double-sized when writing) */
     unsigned char *out;     /* output buffer (double-sized when reading) */
     int direct;             /* 0 if processing gzip, 1 if transparent */
         /* just for reading */
diff --git a/erts/emulator/zlib/inffast.c b/erts/emulator/zlib/inffast.c
index 5187743fde..0dbd1dbc09 100644
--- a/erts/emulator/zlib/inffast.c
+++ b/erts/emulator/zlib/inffast.c
@@ -1,36 +1,16 @@
 /* inffast.c -- fast decoding
- * Copyright (C) 1995-2008, 2010, 2013 Mark Adler
+ * Copyright (C) 1995-2017 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
 #include "zutil.h"
 #include "inftrees.h"
 #include "inflate.h"
 #include "inffast.h"
 
-#ifndef ASMINF
-
-/* Allow machine dependent optimization for post-increment or pre-increment.
-   Based on testing to date,
-   Pre-increment preferred for:
-   - PowerPC G3 (Adler)
-   - MIPS R5000 (Randers-Pehrson)
-   Post-increment preferred for:
-   - none
-   No measurable difference:
-   - Pentium III (Anderson)
-   - M68060 (Nikl)
- */
-#ifdef POSTINC
-#  define OFF 0
-#  define PUP(a) *(a)++
+#ifdef ASMINF
+#  pragma message("Assembler code may have bugs -- use at your own risk")
 #else
-#  define OFF 1
-#  define PUP(a) *++(a)
-#endif
 
 /*
    Decode literal, length, and distance codes and write out the resulting
@@ -99,9 +79,9 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
 
     /* copy state to local variables */
     state = (struct inflate_state FAR *)strm->state;
-    in = strm->next_in - OFF;
+    in = strm->next_in;
     last = in + (strm->avail_in - 5);
-    out = strm->next_out - OFF;
+    out = strm->next_out;
     beg = out - (start - strm->avail_out);
     end = out + (strm->avail_out - 257);
 #ifdef INFLATE_STRICT
@@ -122,9 +102,9 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
        input data or output space */
     do {
         if (bits < 15) {
-            hold += (unsigned long)(PUP(in)) << bits;
+            hold += (unsigned long)(*in++) << bits;
             bits += 8;
-            hold += (unsigned long)(PUP(in)) << bits;
+            hold += (unsigned long)(*in++) << bits;
             bits += 8;
         }
         here = lcode[hold & lmask];
@@ -137,14 +117,14 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
             Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
                     "inflate:         literal '%c'\n" :
                     "inflate:         literal 0x%02x\n", here.val));
-            PUP(out) = (unsigned char)(here.val);
+            *out++ = (unsigned char)(here.val);
         }
         else if (op & 16) {                     /* length base */
             len = (unsigned)(here.val);
             op &= 15;                           /* number of extra bits */
             if (op) {
                 if (bits < op) {
-                    hold += (unsigned long)(PUP(in)) << bits;
+                    hold += (unsigned long)(*in++) << bits;
                     bits += 8;
                 }
                 len += (unsigned)hold & ((1U << op) - 1);
@@ -153,9 +133,9 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
             }
             Tracevv((stderr, "inflate:         length %u\n", len));
             if (bits < 15) {
-                hold += (unsigned long)(PUP(in)) << bits;
+                hold += (unsigned long)(*in++) << bits;
                 bits += 8;
-                hold += (unsigned long)(PUP(in)) << bits;
+                hold += (unsigned long)(*in++) << bits;
                 bits += 8;
             }
             here = dcode[hold & dmask];
@@ -168,10 +148,10 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
                 dist = (unsigned)(here.val);
                 op &= 15;                       /* number of extra bits */
                 if (bits < op) {
-                    hold += (unsigned long)(PUP(in)) << bits;
+                    hold += (unsigned long)(*in++) << bits;
                     bits += 8;
                     if (bits < op) {
-                        hold += (unsigned long)(PUP(in)) << bits;
+                        hold += (unsigned long)(*in++) << bits;
                         bits += 8;
                     }
                 }
@@ -199,30 +179,30 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
 #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
                         if (len <= op - whave) {
                             do {
-                                PUP(out) = 0;
+                                *out++ = 0;
                             } while (--len);
                             continue;
                         }
                         len -= op - whave;
                         do {
-                            PUP(out) = 0;
+                            *out++ = 0;
                         } while (--op > whave);
                         if (op == 0) {
                             from = out - dist;
                             do {
-                                PUP(out) = PUP(from);
+                                *out++ = *from++;
                             } while (--len);
                             continue;
                         }
 #endif
                     }
-                    from = window - OFF;
+                    from = window;
                     if (wnext == 0) {           /* very common case */
                         from += wsize - op;
                         if (op < len) {         /* some from window */
                             len -= op;
                             do {
-                                PUP(out) = PUP(from);
+                                *out++ = *from++;
                             } while (--op);
                             from = out - dist;  /* rest from output */
                         }
@@ -233,14 +213,14 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
                         if (op < len) {         /* some from end of window */
                             len -= op;
                             do {
-                                PUP(out) = PUP(from);
+                                *out++ = *from++;
                             } while (--op);
-                            from = window - OFF;
+                            from = window;
                             if (wnext < len) {  /* some from start of window */
                                 op = wnext;
                                 len -= op;
                                 do {
-                                    PUP(out) = PUP(from);
+                                    *out++ = *from++;
                                 } while (--op);
                                 from = out - dist;      /* rest from output */
                             }
@@ -251,35 +231,35 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
                         if (op < len) {         /* some from window */
                             len -= op;
                             do {
-                                PUP(out) = PUP(from);
+                                *out++ = *from++;
                             } while (--op);
                             from = out - dist;  /* rest from output */
                         }
                     }
                     while (len > 2) {
-                        PUP(out) = PUP(from);
-                        PUP(out) = PUP(from);
-                        PUP(out) = PUP(from);
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        *out++ = *from++;
                         len -= 3;
                     }
                     if (len) {
-                        PUP(out) = PUP(from);
+                        *out++ = *from++;
                         if (len > 1)
-                            PUP(out) = PUP(from);
+                            *out++ = *from++;
                     }
                 }
                 else {
                     from = out - dist;          /* copy direct from output */
                     do {                        /* minimum length is three */
-                        PUP(out) = PUP(from);
-                        PUP(out) = PUP(from);
-                        PUP(out) = PUP(from);
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        *out++ = *from++;
                         len -= 3;
                     } while (len > 2);
                     if (len) {
-                        PUP(out) = PUP(from);
+                        *out++ = *from++;
                         if (len > 1)
-                            PUP(out) = PUP(from);
+                            *out++ = *from++;
                     }
                 }
             }
@@ -316,8 +296,8 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
     hold &= (1U << bits) - 1;
 
     /* update state and return */
-    strm->next_in = in + OFF;
-    strm->next_out = out + OFF;
+    strm->next_in = in;
+    strm->next_out = out;
     strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
     strm->avail_out = (unsigned)(out < end ?
                                  257 + (end - out) : 257 - (out - end));
diff --git a/erts/emulator/zlib/inflate.c b/erts/emulator/zlib/inflate.c
index 532330b06b..ac333e8c2e 100644
--- a/erts/emulator/zlib/inflate.c
+++ b/erts/emulator/zlib/inflate.c
@@ -1,5 +1,5 @@
 /* inflate.c -- zlib decompression
- * Copyright (C) 1995-2012 Mark Adler
+ * Copyright (C) 1995-2016 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -80,9 +80,6 @@
  * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
  */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
 #include "zutil.h"
 #include "inftrees.h"
 #include "inflate.h"
@@ -95,6 +92,7 @@
 #endif
 
 /* function prototypes */
+local int inflateStateCheck OF((z_streamp strm));
 local void fixedtables OF((struct inflate_state FAR *state));
 local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
                            unsigned copy));
@@ -104,12 +102,26 @@ local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
 local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
                               unsigned len));
 
+local int inflateStateCheck(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (strm == Z_NULL ||
+        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
+        return 1;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state == Z_NULL || state->strm != strm ||
+        state->mode < HEAD || state->mode > SYNC)
+        return 1;
+    return 0;
+}
+
 int ZEXPORT inflateResetKeep(strm)
 z_streamp strm;
 {
     struct inflate_state FAR *state;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
     strm->total_in = strm->total_out = state->total = 0;
     strm->msg = Z_NULL;
@@ -134,7 +146,7 @@ z_streamp strm;
 {
     struct inflate_state FAR *state;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
     state->wsize = 0;
     state->whave = 0;
@@ -150,7 +162,7 @@ int windowBits;
     struct inflate_state FAR *state;
 
     /* get the state */
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
 
     /* extract wrap request from windowBits parameter */
@@ -159,7 +171,7 @@ int windowBits;
         windowBits = -windowBits;
     }
     else {
-        wrap = (windowBits >> 4) + 1;
+        wrap = (windowBits >> 4) + 5;
 #ifdef GUNZIP
         if (windowBits < 48)
             windowBits &= 15;
@@ -213,7 +225,9 @@ int stream_size;
     if (state == Z_NULL) return Z_MEM_ERROR;
     Tracev((stderr, "inflate: allocated\n"));
     strm->state = (struct internal_state FAR *)state;
+    state->strm = strm;
     state->window = Z_NULL;
+    state->mode = HEAD;     /* to pass state test in inflateReset2() */
     ret = inflateReset2(strm, windowBits);
     if (ret != Z_OK) {
         ZFREE(strm, state);
@@ -237,17 +251,17 @@ int value;
 {
     struct inflate_state FAR *state;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
     if (bits < 0) {
         state->hold = 0;
         state->bits = 0;
         return Z_OK;
     }
-    if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
+    if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
     value &= (1L << bits) - 1;
-    state->hold += value << state->bits;
-    state->bits += bits;
+    state->hold += (unsigned)value << state->bits;
+    state->bits += (uInt)bits;
     return Z_OK;
 }
 
@@ -628,7 +642,7 @@ int flush;
     static const unsigned short order[19] = /* permutation of code lengths */
         {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
 
-    if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
+    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
         (strm->next_in == Z_NULL && strm->avail_in != 0))
         return Z_STREAM_ERROR;
 
@@ -648,6 +662,8 @@ int flush;
             NEEDBITS(16);
 #ifdef GUNZIP
             if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
+                if (state->wbits == 0)
+                    state->wbits = 15;
                 state->check = crc32(0L, Z_NULL, 0);
                 CRC2(state->check, hold);
                 INITBITS();
@@ -675,7 +691,7 @@ int flush;
             len = BITS(4) + 8;
             if (state->wbits == 0)
                 state->wbits = len;
-            else if (len > state->wbits) {
+            if (len > 15 || len > state->wbits) {
                 strm->msg = (char *)"invalid window size";
                 state->mode = BAD;
                 break;
@@ -702,14 +718,16 @@ int flush;
             }
             if (state->head != Z_NULL)
                 state->head->text = (int)((hold >> 8) & 1);
-            if (state->flags & 0x0200) CRC2(state->check, hold);
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC2(state->check, hold);
             INITBITS();
             state->mode = TIME;
         case TIME:
             NEEDBITS(32);
             if (state->head != Z_NULL)
                 state->head->time = hold;
-            if (state->flags & 0x0200) CRC4(state->check, hold);
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC4(state->check, hold);
             INITBITS();
             state->mode = OS;
         case OS:
@@ -718,7 +736,8 @@ int flush;
                 state->head->xflags = (int)(hold & 0xff);
                 state->head->os = (int)(hold >> 8);
             }
-            if (state->flags & 0x0200) CRC2(state->check, hold);
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC2(state->check, hold);
             INITBITS();
             state->mode = EXLEN;
         case EXLEN:
@@ -727,7 +746,8 @@ int flush;
                 state->length = (unsigned)(hold);
                 if (state->head != Z_NULL)
                     state->head->extra_len = (unsigned)hold;
-                if (state->flags & 0x0200) CRC2(state->check, hold);
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    CRC2(state->check, hold);
                 INITBITS();
             }
             else if (state->head != Z_NULL)
@@ -745,7 +765,7 @@ int flush;
                                 len + copy > state->head->extra_max ?
                                 state->head->extra_max - len : copy);
                     }
-                    if (state->flags & 0x0200)
+                    if ((state->flags & 0x0200) && (state->wrap & 4))
                         state->check = crc32(state->check, next, copy);
                     have -= copy;
                     next += copy;
@@ -764,9 +784,9 @@ int flush;
                     if (state->head != Z_NULL &&
                             state->head->name != Z_NULL &&
                             state->length < state->head->name_max)
-                        state->head->name[state->length++] = len;
+                        state->head->name[state->length++] = (Bytef)len;
                 } while (len && copy < have);
-                if (state->flags & 0x0200)
+                if ((state->flags & 0x0200) && (state->wrap & 4))
                     state->check = crc32(state->check, next, copy);
                 have -= copy;
                 next += copy;
@@ -785,9 +805,9 @@ int flush;
                     if (state->head != Z_NULL &&
                             state->head->comment != Z_NULL &&
                             state->length < state->head->comm_max)
-                        state->head->comment[state->length++] = len;
+                        state->head->comment[state->length++] = (Bytef)len;
                 } while (len && copy < have);
-                if (state->flags & 0x0200)
+                if ((state->flags & 0x0200) && (state->wrap & 4))
                     state->check = crc32(state->check, next, copy);
                 have -= copy;
                 next += copy;
@@ -799,7 +819,7 @@ int flush;
         case HCRC:
             if (state->flags & 0x0200) {
                 NEEDBITS(16);
-                if (hold != (state->check & 0xffff)) {
+                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
                     strm->msg = (char *)"header crc mismatch";
                     state->mode = BAD;
                     break;
@@ -1180,11 +1200,11 @@ int flush;
                 out -= left;
                 strm->total_out += out;
                 state->total += out;
-                if (out)
+                if ((state->wrap & 4) && out)
                     strm->adler = state->check =
                         UPDATE(state->check, put - out, out);
                 out = left;
-                if ((
+                if ((state->wrap & 4) && (
 #ifdef GUNZIP
                      state->flags ? hold :
 #endif
@@ -1243,10 +1263,10 @@ int flush;
     strm->total_in += in;
     strm->total_out += out;
     state->total += out;
-    if (state->wrap && out)
+    if ((state->wrap & 4) && out)
         strm->adler = state->check =
             UPDATE(state->check, strm->next_out - out, out);
-    strm->data_type = state->bits + (state->last ? 64 : 0) +
+    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
                       (state->mode == TYPE ? 128 : 0) +
                       (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
     if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
@@ -1258,7 +1278,7 @@ int ZEXPORT inflateEnd(strm)
 z_streamp strm;
 {
     struct inflate_state FAR *state;
-    if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
+    if (inflateStateCheck(strm))
         return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
     if (state->window != Z_NULL) ZFREE(strm, state->window);
@@ -1276,7 +1296,7 @@ uInt *dictLength;
     struct inflate_state FAR *state;
 
     /* check state */
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
 
     /* copy dictionary */
@@ -1301,7 +1321,7 @@ uInt dictLength;
     int ret;
 
     /* check state */
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
     if (state->wrap != 0 && state->mode != DICT)
         return Z_STREAM_ERROR;
@@ -1333,7 +1353,7 @@ gz_headerp head;
     struct inflate_state FAR *state;
 
     /* check state */
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
     if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
 
@@ -1386,7 +1406,7 @@ z_streamp strm;
     struct inflate_state FAR *state;
 
     /* check parameters */
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
     if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
 
@@ -1433,7 +1453,7 @@ z_streamp strm;
 {
     struct inflate_state FAR *state;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
     return state->mode == STORED && state->bits == 0;
 }
@@ -1448,8 +1468,7 @@ z_streamp source;
     unsigned wsize;
 
     /* check input */
-    if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
-        source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
+    if (inflateStateCheck(source) || dest == Z_NULL)
         return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)source->state;
 
@@ -1470,6 +1489,7 @@ z_streamp source;
     /* copy state */
     zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
     zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
+    copy->strm = dest;
     if (state->lencode >= state->codes &&
         state->lencode <= state->codes + ENOUGH - 1) {
         copy->lencode = copy->codes + (state->lencode - state->codes);
@@ -1491,25 +1511,51 @@ int subvert;
 {
     struct inflate_state FAR *state;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
     state = (struct inflate_state FAR *)strm->state;
-    state->sane = !subvert;
 #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+    state->sane = !subvert;
     return Z_OK;
 #else
+    (void)subvert;
     state->sane = 1;
     return Z_DATA_ERROR;
 #endif
 }
 
+int ZEXPORT inflateValidate(strm, check)
+z_streamp strm;
+int check;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (check)
+        state->wrap |= 4;
+    else
+        state->wrap &= ~4;
+    return Z_OK;
+}
+
 long ZEXPORT inflateMark(strm)
 z_streamp strm;
 {
     struct inflate_state FAR *state;
 
-    if (strm == Z_NULL || strm->state == Z_NULL) return -1L << 16;
+    if (inflateStateCheck(strm))
+        return -(1L << 16);
     state = (struct inflate_state FAR *)strm->state;
-    return ((long)(state->back) << 16) +
+    return (long)(((unsigned long)((long)state->back)) << 16) +
         (state->mode == COPY ? state->length :
             (state->mode == MATCH ? state->was - state->length : 0));
 }
+
+unsigned long ZEXPORT inflateCodesUsed(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (inflateStateCheck(strm)) return (unsigned long)-1;
+    state = (struct inflate_state FAR *)strm->state;
+    return (unsigned long)(state->next - state->codes);
+}
diff --git a/erts/emulator/zlib/inflate.h b/erts/emulator/zlib/inflate.h
index 95f4986d40..a46cce6b6d 100644
--- a/erts/emulator/zlib/inflate.h
+++ b/erts/emulator/zlib/inflate.h
@@ -1,5 +1,5 @@
 /* inflate.h -- internal inflate state definition
- * Copyright (C) 1995-2009 Mark Adler
+ * Copyright (C) 1995-2016 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -18,7 +18,7 @@
 
 /* Possible inflate modes between inflate() calls */
 typedef enum {
-    HEAD,       /* i: waiting for magic header */
+    HEAD = 16180,   /* i: waiting for magic header */
     FLAGS,      /* i: waiting for method and flags (gzip) */
     TIME,       /* i: waiting for modification time (gzip) */
     OS,         /* i: waiting for extra flags and operating system (gzip) */
@@ -77,11 +77,14 @@ typedef enum {
         CHECK -> LENGTH -> DONE
  */
 
-/* state maintained between inflate() calls.  Approximately 10K bytes. */
+/* State maintained between inflate() calls -- approximately 7K bytes, not
+   including the allocated sliding window, which is up to 32K bytes. */
 struct inflate_state {
+    z_streamp strm;             /* pointer back to this zlib stream */
     inflate_mode mode;          /* current inflate mode */
     int last;                   /* true if processing last block */
-    int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip */
+    int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip,
+                                   bit 2 true to validate check value */
     int havedict;               /* true if dictionary provided */
     int flags;                  /* gzip header method and flags (0 if zlib) */
     unsigned dmax;              /* zlib header max distance (INFLATE_STRICT) */
diff --git a/erts/emulator/zlib/inftrees.c b/erts/emulator/zlib/inftrees.c
index 3766fa2646..2ea08fc13e 100644
--- a/erts/emulator/zlib/inftrees.c
+++ b/erts/emulator/zlib/inftrees.c
@@ -1,18 +1,15 @@
 /* inftrees.c -- generate Huffman trees for efficient decoding
- * Copyright (C) 1995-2013 Mark Adler
+ * Copyright (C) 1995-2017 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
 #include "zutil.h"
 #include "inftrees.h"
 
 #define MAXBITS 15
 
 const char inflate_copyright[] =
-   " inflate 1.2.8 Copyright 1995-2013 Mark Adler ";
+   " inflate 1.2.11 Copyright 1995-2017 Mark Adler ";
 /*
   If you use the zlib library in a product, an acknowledgment is welcome
   in the documentation of your product. If for some reason you cannot
@@ -57,7 +54,7 @@ unsigned short FAR *work;
     code FAR *next;             /* next available space in table */
     const unsigned short FAR *base;     /* base value table to use */
     const unsigned short FAR *extra;    /* extra bits table to use */
-    int end;                    /* use base and extra for symbol > end */
+    unsigned match;             /* use base and extra for symbol >= match */
     unsigned short count[MAXBITS+1];    /* number of codes of each length */
     unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
     static const unsigned short lbase[31] = { /* Length codes 257..285 base */
@@ -65,7 +62,7 @@ unsigned short FAR *work;
         35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
     static const unsigned short lext[31] = { /* Length codes 257..285 extra */
         16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
-        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 72, 78};
+        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 77, 202};
     static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
         1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
         257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
@@ -184,19 +181,17 @@ unsigned short FAR *work;
     switch (type) {
     case CODES:
         base = extra = work;    /* dummy value--not used */
-        end = 19;
+        match = 20;
         break;
     case LENS:
         base = lbase;
-        base -= 257;
         extra = lext;
-        extra -= 257;
-        end = 256;
+        match = 257;
         break;
-    default:            /* DISTS */
+    default:    /* DISTS */
         base = dbase;
         extra = dext;
-        end = -1;
+        match = 0;
     }
 
     /* initialize state for loop */
@@ -219,13 +214,13 @@ unsigned short FAR *work;
     for (;;) {
         /* create table entry */
         here.bits = (unsigned char)(len - drop);
-        if ((int)(work[sym]) < end) {
+        if (work[sym] + 1U < match) {
             here.op = (unsigned char)0;
             here.val = work[sym];
         }
-        else if ((int)(work[sym]) > end) {
-            here.op = (unsigned char)(extra[work[sym]]);
-            here.val = base[work[sym]];
+        else if (work[sym] >= match) {
+            here.op = (unsigned char)(extra[work[sym] - match]);
+            here.val = base[work[sym] - match];
         }
         else {
             here.op = (unsigned char)(32 + 64);         /* end of block */
diff --git a/erts/emulator/zlib/trees.c b/erts/emulator/zlib/trees.c
index 465e944e5b..50cf4b4571 100644
--- a/erts/emulator/zlib/trees.c
+++ b/erts/emulator/zlib/trees.c
@@ -1,5 +1,5 @@
 /* trees.c -- output deflated data using Huffman coding
- * Copyright (C) 1995-2012 Jean-loup Gailly
+ * Copyright (C) 1995-2017 Jean-loup Gailly
  * detect_data_type() function provided freely by Cosmin Truta, 2006
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
@@ -34,12 +34,9 @@
 
 /* #define GEN_TREES_H */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
 #include "deflate.h"
 
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
 #  include <ctype.h>
 #endif
 
@@ -125,13 +122,13 @@ struct static_tree_desc_s {
     int     max_length;          /* max bit length for the codes */
 };
 
-local static_tree_desc  static_l_desc =
+local const static_tree_desc  static_l_desc =
 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
 
-local static_tree_desc  static_d_desc =
+local const static_tree_desc  static_d_desc =
 {static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};
 
-local static_tree_desc  static_bl_desc =
+local const static_tree_desc  static_bl_desc =
 {(const ct_data *)0, extra_blbits, 0,   BL_CODES, MAX_BL_BITS};
 
 /* ===========================================================================
@@ -155,18 +152,16 @@ local int  detect_data_type OF((deflate_state *s));
 local unsigned bi_reverse OF((unsigned value, int length));
 local void bi_windup      OF((deflate_state *s));
 local void bi_flush       OF((deflate_state *s));
-local void copy_block     OF((deflate_state *s, charf *buf, unsigned len,
-                              int header));
 
 #ifdef GEN_TREES_H
 local void gen_trees_header OF((void));
 #endif
 
-#ifndef DEBUG
+#ifndef ZLIB_DEBUG
 #  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
    /* Send a code of the given tree. c and tree must not have side effects */
 
-#else /* DEBUG */
+#else /* !ZLIB_DEBUG */
 #  define send_code(s, c, tree) \
      { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
        send_bits(s, tree[c].Code, tree[c].Len); }
@@ -185,7 +180,7 @@ local void gen_trees_header OF((void));
  * Send a value on a given number of bits.
  * IN assertion: length <= 16 and value fits in length bits.
  */
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
 local void send_bits      OF((deflate_state *s, int value, int length));
 
 local void send_bits(s, value, length)
@@ -211,12 +206,12 @@ local void send_bits(s, value, length)
         s->bi_valid += length;
     }
 }
-#else /* !DEBUG */
+#else /* !ZLIB_DEBUG */
 
 #define send_bits(s, value, length) \
 { int len = length;\
   if (s->bi_valid > (int)Buf_size - len) {\
-    int val = value;\
+    int val = (int)value;\
     s->bi_buf |= (ush)val << s->bi_valid;\
     put_short(s, s->bi_buf);\
     s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
@@ -226,7 +221,7 @@ local void send_bits(s, value, length)
     s->bi_valid += len;\
   }\
 }
-#endif /* DEBUG */
+#endif /* ZLIB_DEBUG */
 
 
 /* the arguments must not have side effects */
@@ -320,7 +315,7 @@ local void tr_static_init()
  * Genererate the file trees.h describing the static trees.
  */
 #ifdef GEN_TREES_H
-#  ifndef DEBUG
+#  ifndef ZLIB_DEBUG
 #    include <stdio.h>
 #  endif
 
@@ -397,7 +392,7 @@ void ZLIB_INTERNAL _tr_init(s)
 
     s->bi_buf = 0;
     s->bi_valid = 0;
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
     s->compressed_len = 0L;
     s->bits_sent = 0L;
 #endif
@@ -525,12 +520,12 @@ local void gen_bitlen(s, desc)
         xbits = 0;
         if (n >= base) xbits = extra[n-base];
         f = tree[n].Freq;
-        s->opt_len += (ulg)f * (bits + xbits);
-        if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
+        s->opt_len += (ulg)f * (unsigned)(bits + xbits);
+        if (stree) s->static_len += (ulg)f * (unsigned)(stree[n].Len + xbits);
     }
     if (overflow == 0) return;
 
-    Trace((stderr,"\nbit length overflow\n"));
+    Tracev((stderr,"\nbit length overflow\n"));
     /* This happens for example on obj2 and pic of the Calgary corpus */
 
     /* Find the first bit length which could increase: */
@@ -557,9 +552,8 @@ local void gen_bitlen(s, desc)
             m = s->heap[--h];
             if (m > max_code) continue;
             if ((unsigned) tree[m].Len != (unsigned) bits) {
-                Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
-                s->opt_len += ((long)bits - (long)tree[m].Len)
-                              *(long)tree[m].Freq;
+                Tracev((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
+                s->opt_len += ((ulg)bits - tree[m].Len) * tree[m].Freq;
                 tree[m].Len = (ush)bits;
             }
             n--;
@@ -581,7 +575,7 @@ local void gen_codes (tree, max_code, bl_count)
     ushf *bl_count;            /* number of codes at each bit length */
 {
     ush next_code[MAX_BITS+1]; /* next code value for each bit length */
-    ush code = 0;              /* running code value */
+    unsigned code = 0;         /* running code value */
     int bits;                  /* bit index */
     int n;                     /* code index */
 
@@ -589,7 +583,8 @@ local void gen_codes (tree, max_code, bl_count)
      * without bit reversal.
      */
     for (bits = 1; bits <= MAX_BITS; bits++) {
-        next_code[bits] = code = (code + bl_count[bits-1]) << 1;
+        code = (code + bl_count[bits-1]) << 1;
+        next_code[bits] = (ush)code;
     }
     /* Check that the bit counts in bl_count are consistent. The last code
      * must be all ones.
@@ -602,7 +597,7 @@ local void gen_codes (tree, max_code, bl_count)
         int len = tree[n].Len;
         if (len == 0) continue;
         /* Now reverse the bits */
-        tree[n].Code = bi_reverse(next_code[len]++, len);
+        tree[n].Code = (ush)bi_reverse(next_code[len]++, len);
 
         Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
              n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
@@ -824,7 +819,7 @@ local int build_bl_tree(s)
         if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
     }
     /* Update opt_len to include the bit length tree and counts */
-    s->opt_len += 3*(max_blindex+1) + 5+5+4;
+    s->opt_len += 3*((ulg)max_blindex+1) + 5+5+4;
     Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
             s->opt_len, s->static_len));
 
@@ -872,11 +867,17 @@ void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
     int last;         /* one if this is the last block for a file */
 {
     send_bits(s, (STORED_BLOCK<<1)+last, 3);    /* send block type */
-#ifdef DEBUG
+    bi_windup(s);        /* align on byte boundary */
+    put_short(s, (ush)stored_len);
+    put_short(s, (ush)~stored_len);
+    zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
+    s->pending += stored_len;
+#ifdef ZLIB_DEBUG
     s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
     s->compressed_len += (stored_len + 4) << 3;
+    s->bits_sent += 2*16;
+    s->bits_sent += stored_len<<3;
 #endif
-    copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
 }
 
 /* ===========================================================================
@@ -897,7 +898,7 @@ void ZLIB_INTERNAL _tr_align(s)
 {
     send_bits(s, STATIC_TREES<<1, 3);
     send_code(s, END_BLOCK, static_ltree);
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
     s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
 #endif
     bi_flush(s);
@@ -905,7 +906,7 @@ void ZLIB_INTERNAL _tr_align(s)
 
 /* ===========================================================================
  * Determine the best encoding for the current block: dynamic trees, static
- * trees or store, and output the encoded block to the zip file.
+ * trees or store, and write out the encoded block.
  */
 void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
     deflate_state *s;
@@ -977,7 +978,7 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
         send_bits(s, (STATIC_TREES<<1)+last, 3);
         compress_block(s, (const ct_data *)static_ltree,
                        (const ct_data *)static_dtree);
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
         s->compressed_len += 3 + s->static_len;
 #endif
     } else {
@@ -986,7 +987,7 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
                        max_blindex+1);
         compress_block(s, (const ct_data *)s->dyn_ltree,
                        (const ct_data *)s->dyn_dtree);
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
         s->compressed_len += 3 + s->opt_len;
 #endif
     }
@@ -998,7 +999,7 @@ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
 
     if (last) {
         bi_windup(s);
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
         s->compressed_len += 7;  /* align on byte boundary */
 #endif
     }
@@ -1093,7 +1094,7 @@ local void compress_block(s, ltree, dtree)
             send_code(s, code, dtree);       /* send the distance code */
             extra = extra_dbits[code];
             if (extra != 0) {
-                dist -= base_dist[code];
+                dist -= (unsigned)base_dist[code];
                 send_bits(s, dist, extra);   /* send the extra distance bits */
             }
         } /* literal or match pair ? */
@@ -1196,34 +1197,7 @@ local void bi_windup(s)
     }
     s->bi_buf = 0;
     s->bi_valid = 0;
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
     s->bits_sent = (s->bits_sent+7) & ~7;
 #endif
 }
-
-/* ===========================================================================
- * Copy a stored block, storing first the length and its
- * one's complement if requested.
- */
-local void copy_block(s, buf, len, header)
-    deflate_state *s;
-    charf    *buf;    /* the input data */
-    unsigned len;     /* its length */
-    int      header;  /* true if block header must be written */
-{
-    bi_windup(s);        /* align on byte boundary */
-
-    if (header) {
-        put_short(s, (ush)len);
-        put_short(s, (ush)~len);
-#ifdef DEBUG
-        s->bits_sent += 2*16;
-#endif
-    }
-#ifdef DEBUG
-    s->bits_sent += (ulg)len<<3;
-#endif
-    while (len--) {
-        put_byte(s, *buf++);
-    }
-}
diff --git a/erts/emulator/zlib/uncompr.c b/erts/emulator/zlib/uncompr.c
index 864d571719..f03a1a865e 100644
--- a/erts/emulator/zlib/uncompr.c
+++ b/erts/emulator/zlib/uncompr.c
@@ -1,62 +1,93 @@
 /* uncompr.c -- decompress a memory buffer
- * Copyright (C) 1995-2003, 2010 Jean-loup Gailly.
+ * Copyright (C) 1995-2003, 2010, 2014, 2016 Jean-loup Gailly, Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 /* @(#) $Id$ */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
 #define ZLIB_INTERNAL
 #include "zlib.h"
 
 /* ===========================================================================
-     Decompresses the source buffer into the destination buffer.  sourceLen is
-   the byte length of the source buffer. Upon entry, destLen is the total
-   size of the destination buffer, which must be large enough to hold the
-   entire uncompressed data. (The size of the uncompressed data must have
-   been saved previously by the compressor and transmitted to the decompressor
-   by some mechanism outside the scope of this compression library.)
-   Upon exit, destLen is the actual size of the compressed buffer.
-
-     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
-   enough memory, Z_BUF_ERROR if there was not enough room in the output
-   buffer, or Z_DATA_ERROR if the input data was corrupted.
+     Decompresses the source buffer into the destination buffer.  *sourceLen is
+   the byte length of the source buffer. Upon entry, *destLen is the total size
+   of the destination buffer, which must be large enough to hold the entire
+   uncompressed data. (The size of the uncompressed data must have been saved
+   previously by the compressor and transmitted to the decompressor by some
+   mechanism outside the scope of this compression library.) Upon exit,
+   *destLen is the size of the decompressed data and *sourceLen is the number
+   of source bytes consumed. Upon return, source + *sourceLen points to the
+   first unused input byte.
+
+     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer, or
+   Z_DATA_ERROR if the input data was corrupted, including if the input data is
+   an incomplete zlib stream.
 */
-int ZEXPORT uncompress (dest, destLen, source, sourceLen)
+int ZEXPORT uncompress2 (dest, destLen, source, sourceLen)
     Bytef *dest;
     uLongf *destLen;
     const Bytef *source;
-    uLong sourceLen;
+    uLong *sourceLen;
 {
     z_stream stream;
     int err;
+    const uInt max = (uInt)-1;
+    uLong len, left;
+    Byte buf[1];    /* for detection of incomplete stream when *destLen == 0 */
 
-    stream.next_in = (z_const Bytef *)source;
-    stream.avail_in = (uInt)sourceLen;
-    /* Check for source > 64K on 16-bit machine: */
-    if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
-
-    stream.next_out = dest;
-    stream.avail_out = (uInt)*destLen;
-    if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
+    len = *sourceLen;
+    if (*destLen) {
+        left = *destLen;
+        *destLen = 0;
+    }
+    else {
+        left = 1;
+        dest = buf;
+    }
 
+    stream.next_in = (z_const Bytef *)source;
+    stream.avail_in = 0;
     stream.zalloc = (alloc_func)0;
     stream.zfree = (free_func)0;
+    stream.opaque = (voidpf)0;
 
     err = inflateInit(&stream);
     if (err != Z_OK) return err;
 
-    err = inflate(&stream, Z_FINISH);
-    if (err != Z_STREAM_END) {
-        inflateEnd(&stream);
-        if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0))
-            return Z_DATA_ERROR;
-        return err;
-    }
-    *destLen = stream.total_out;
+    stream.next_out = dest;
+    stream.avail_out = 0;
 
-    err = inflateEnd(&stream);
-    return err;
+    do {
+        if (stream.avail_out == 0) {
+            stream.avail_out = left > (uLong)max ? max : (uInt)left;
+            left -= stream.avail_out;
+        }
+        if (stream.avail_in == 0) {
+            stream.avail_in = len > (uLong)max ? max : (uInt)len;
+            len -= stream.avail_in;
+        }
+        err = inflate(&stream, Z_NO_FLUSH);
+    } while (err == Z_OK);
+
+    *sourceLen -= len + stream.avail_in;
+    if (dest != buf)
+        *destLen = stream.total_out;
+    else if (stream.total_out && err == Z_BUF_ERROR)
+        left = 1;
+
+    inflateEnd(&stream);
+    return err == Z_STREAM_END ? Z_OK :
+           err == Z_NEED_DICT ? Z_DATA_ERROR  :
+           err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
+           err;
+}
+
+int ZEXPORT uncompress (dest, destLen, source, sourceLen)
+    Bytef *dest;
+    uLongf *destLen;
+    const Bytef *source;
+    uLong sourceLen;
+{
+    return uncompress2(dest, destLen, source, &sourceLen);
 }
diff --git a/erts/emulator/zlib/zconf.h b/erts/emulator/zlib/zconf.h
index 9987a77553..5e1d68a004 100644
--- a/erts/emulator/zlib/zconf.h
+++ b/erts/emulator/zlib/zconf.h
@@ -1,5 +1,5 @@
 /* zconf.h -- configuration of the zlib compression library
- * Copyright (C) 1995-2013 Jean-loup Gailly.
+ * Copyright (C) 1995-2016 Jean-loup Gailly, Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -17,7 +17,7 @@
 #ifdef Z_PREFIX     /* may be set to #if 1 by ./configure */
 #  define Z_PREFIX_SET
 
-/* all linked symbols */
+/* all linked symbols and init macros */
 #  define _dist_code            z__dist_code
 #  define _length_code          z__length_code
 #  define _tr_align             z__tr_align
@@ -29,6 +29,7 @@
 #  define adler32               z_adler32
 #  define adler32_combine       z_adler32_combine
 #  define adler32_combine64     z_adler32_combine64
+#  define adler32_z             z_adler32_z
 #  ifndef Z_SOLO
 #    define compress              z_compress
 #    define compress2             z_compress2
@@ -37,10 +38,14 @@
 #  define crc32                 z_crc32
 #  define crc32_combine         z_crc32_combine
 #  define crc32_combine64       z_crc32_combine64
+#  define crc32_z               z_crc32_z
 #  define deflate               z_deflate
 #  define deflateBound          z_deflateBound
 #  define deflateCopy           z_deflateCopy
 #  define deflateEnd            z_deflateEnd
+#  define deflateGetDictionary  z_deflateGetDictionary
+#  define deflateInit           z_deflateInit
+#  define deflateInit2          z_deflateInit2
 #  define deflateInit2_         z_deflateInit2_
 #  define deflateInit_          z_deflateInit_
 #  define deflateParams         z_deflateParams
@@ -67,6 +72,8 @@
 #    define gzeof                 z_gzeof
 #    define gzerror               z_gzerror
 #    define gzflush               z_gzflush
+#    define gzfread               z_gzfread
+#    define gzfwrite              z_gzfwrite
 #    define gzgetc                z_gzgetc
 #    define gzgetc_               z_gzgetc_
 #    define gzgets                z_gzgets
@@ -78,7 +85,6 @@
 #      define gzopen_w              z_gzopen_w
 #    endif
 #    define gzprintf              z_gzprintf
-#    define gzvprintf             z_gzvprintf
 #    define gzputc                z_gzputc
 #    define gzputs                z_gzputs
 #    define gzread                z_gzread
@@ -89,32 +95,39 @@
 #    define gztell                z_gztell
 #    define gztell64              z_gztell64
 #    define gzungetc              z_gzungetc
+#    define gzvprintf             z_gzvprintf
 #    define gzwrite               z_gzwrite
 #  endif
 #  define inflate               z_inflate
 #  define inflateBack           z_inflateBack
 #  define inflateBackEnd        z_inflateBackEnd
+#  define inflateBackInit       z_inflateBackInit
 #  define inflateBackInit_      z_inflateBackInit_
+#  define inflateCodesUsed      z_inflateCodesUsed
 #  define inflateCopy           z_inflateCopy
 #  define inflateEnd            z_inflateEnd
+#  define inflateGetDictionary  z_inflateGetDictionary
 #  define inflateGetHeader      z_inflateGetHeader
+#  define inflateInit           z_inflateInit
+#  define inflateInit2          z_inflateInit2
 #  define inflateInit2_         z_inflateInit2_
 #  define inflateInit_          z_inflateInit_
 #  define inflateMark           z_inflateMark
 #  define inflatePrime          z_inflatePrime
 #  define inflateReset          z_inflateReset
 #  define inflateReset2         z_inflateReset2
+#  define inflateResetKeep      z_inflateResetKeep
 #  define inflateSetDictionary  z_inflateSetDictionary
-#  define inflateGetDictionary  z_inflateGetDictionary
 #  define inflateSync           z_inflateSync
 #  define inflateSyncPoint      z_inflateSyncPoint
 #  define inflateUndermine      z_inflateUndermine
-#  define inflateResetKeep      z_inflateResetKeep
+#  define inflateValidate       z_inflateValidate
 #  define inflate_copyright     z_inflate_copyright
 #  define inflate_fast          z_inflate_fast
 #  define inflate_table         z_inflate_table
 #  ifndef Z_SOLO
 #    define uncompress            z_uncompress
+#    define uncompress2           z_uncompress2
 #  endif
 #  define zError                z_zError
 #  ifndef Z_SOLO
@@ -224,9 +237,19 @@
 #  define z_const
 #endif
 
-/* Some Mac compilers merge all .h files incorrectly: */
-#if defined(__MWERKS__)||defined(applec)||defined(THINK_C)||defined(__SC__)
-#  define NO_DUMMY_DECL
+#ifdef Z_SOLO
+   typedef unsigned long z_size_t;
+#else
+#  define z_longlong long long
+#  if defined(NO_SIZE_T)
+     typedef unsigned NO_SIZE_T z_size_t;
+#  elif defined(STDC)
+#    include <stddef.h>
+     typedef size_t z_size_t;
+#  else
+     typedef unsigned long z_size_t;
+#  endif
+#  undef z_longlong
 #endif
 
 /* Maximum value for memLevel in deflateInit2 */
@@ -256,7 +279,7 @@
  Of course this will generally degrade compression (there's no free lunch).
 
    The memory requirements for inflate are (in bytes) 1 << windowBits
- that is, 32K for windowBits=15 (default value) plus a few kilobytes
+ that is, 32K for windowBits=15 (default value) plus about 7 kilobytes
  for small objects.
 */
 
diff --git a/erts/emulator/zlib/zlib.h b/erts/emulator/zlib/zlib.h
index 3e0c7672ac..f09cdaf1e0 100644
--- a/erts/emulator/zlib/zlib.h
+++ b/erts/emulator/zlib/zlib.h
@@ -1,7 +1,7 @@
 /* zlib.h -- interface of the 'zlib' general purpose compression library
-  version 1.2.8, April 28th, 2013
+  version 1.2.11, January 15th, 2017
 
-  Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
+  Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
 
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
@@ -37,11 +37,11 @@
 extern "C" {
 #endif
 
-#define ZLIB_VERSION "1.2.8"
-#define ZLIB_VERNUM 0x1280
+#define ZLIB_VERSION "1.2.11"
+#define ZLIB_VERNUM 0x12b0
 #define ZLIB_VER_MAJOR 1
 #define ZLIB_VER_MINOR 2
-#define ZLIB_VER_REVISION 8
+#define ZLIB_VER_REVISION 11
 #define ZLIB_VER_SUBREVISION 0
 
 /*
@@ -65,7 +65,8 @@ extern "C" {
   with "gz".  The gzip format is different from the zlib format.  gzip is a
   gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
 
-    This library can optionally read and write gzip streams in memory as well.
+    This library can optionally read and write gzip and raw deflate streams in
+  memory as well.
 
     The zlib format was designed to be compact and fast for use in memory
   and on communications channels.  The gzip format was designed for single-
@@ -74,7 +75,7 @@ extern "C" {
 
     The library does not install any signal handler.  The decoder checks
   the consistency of the compressed data, so the library should never crash
-  even in case of corrupted input.
+  even in the case of corrupted input.
 */
 
 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
@@ -87,7 +88,7 @@ typedef struct z_stream_s {
     uInt     avail_in;  /* number of bytes available at next_in */
     uLong    total_in;  /* total number of input bytes read so far */
 
-    Bytef    *next_out; /* next output byte should be put there */
+    Bytef    *next_out; /* next output byte will go here */
     uInt     avail_out; /* remaining free space at next_out */
     uLong    total_out; /* total number of bytes output so far */
 
@@ -98,8 +99,9 @@ typedef struct z_stream_s {
     free_func  zfree;   /* used to free the internal state */
     voidpf     opaque;  /* private data object passed to zalloc and zfree */
 
-    int     data_type;  /* best guess about the data type: binary or text */
-    uLong   adler;      /* adler32 value of the uncompressed data */
+    int     data_type;  /* best guess about the data type: binary or text
+                           for deflate, or the decoding state for inflate */
+    uLong   adler;      /* Adler-32 or CRC-32 value of the uncompressed data */
     uLong   reserved;   /* reserved for future use */
 } z_stream;
 
@@ -142,7 +144,9 @@ typedef gz_header FAR *gz_headerp;
 
      zalloc must return Z_NULL if there is not enough memory for the object.
    If zlib is used in a multi-threaded application, zalloc and zfree must be
-   thread safe.
+   thread safe.  In that case, zlib is thread-safe.  When zalloc and zfree are
+   Z_NULL on entry to the initialization function, they are set to internal
+   routines that use the standard library functions malloc() and free().
 
      On 16-bit systems, the functions zalloc and zfree must be able to allocate
    exactly 65536 bytes, but will not be required to allocate more than this if
@@ -155,7 +159,7 @@ typedef gz_header FAR *gz_headerp;
 
      The fields total_in and total_out can be used for statistics or progress
    reports.  After compression, total_in holds the total size of the
-   uncompressed data and may be saved for use in the decompressor (particularly
+   uncompressed data and may be saved for use by the decompressor (particularly
    if the decompressor wants to decompress everything in a single step).
 */
 
@@ -200,7 +204,7 @@ typedef gz_header FAR *gz_headerp;
 #define Z_TEXT     1
 #define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */
 #define Z_UNKNOWN  2
-/* Possible values of the data_type field (though see inflate()) */
+/* Possible values of the data_type field for deflate() */
 
 #define Z_DEFLATED   8
 /* The deflate compression method (the only one supported in this version) */
@@ -258,11 +262,11 @@ ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
     enough room in the output buffer), next_in and avail_in are updated and
     processing will resume at this point for the next call of deflate().
 
-  - Provide more output starting at next_out and update next_out and avail_out
+  - Generate more output starting at next_out and update next_out and avail_out
     accordingly.  This action is forced if the parameter flush is non zero.
     Forcing flush frequently degrades the compression ratio, so this parameter
-    should be set only when necessary (in interactive applications).  Some
-    output may be provided even if flush is not set.
+    should be set only when necessary.  Some output may be provided even if
+    flush is zero.
 
     Before the call of deflate(), the application should ensure that at least
   one of the actions is possible, by providing more input and/or consuming more
@@ -271,7 +275,9 @@ ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
   output when it wants, for example when the output buffer is full (avail_out
   == 0), or after each call of deflate().  If deflate returns Z_OK and with
   zero avail_out, it must be called again after making room in the output
-  buffer because there might be more output pending.
+  buffer because there might be more output pending. See deflatePending(),
+  which can be used if desired to determine whether or not there is more ouput
+  in that case.
 
     Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
   decide how much data to accumulate before producing output, in order to
@@ -292,8 +298,8 @@ ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
   input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
   This completes the current deflate block and follows it with an empty fixed
   codes block that is 10 bits long.  This assures that enough bytes are output
-  in order for the decompressor to finish the block before the empty fixed code
-  block.
+  in order for the decompressor to finish the block before the empty fixed
+  codes block.
 
     If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
   for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
@@ -319,34 +325,38 @@ ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
 
     If the parameter flush is set to Z_FINISH, pending input is processed,
   pending output is flushed and deflate returns with Z_STREAM_END if there was
-  enough output space; if deflate returns with Z_OK, this function must be
-  called again with Z_FINISH and more output space (updated avail_out) but no
-  more input data, until it returns with Z_STREAM_END or an error.  After
-  deflate has returned Z_STREAM_END, the only possible operations on the stream
-  are deflateReset or deflateEnd.
-
-    Z_FINISH can be used immediately after deflateInit if all the compression
-  is to be done in a single step.  In this case, avail_out must be at least the
-  value returned by deflateBound (see below).  Then deflate is guaranteed to
-  return Z_STREAM_END.  If not enough output space is provided, deflate will
-  not return Z_STREAM_END, and it must be called again as described above.
-
-    deflate() sets strm->adler to the adler32 checksum of all input read
-  so far (that is, total_in bytes).
+  enough output space.  If deflate returns with Z_OK or Z_BUF_ERROR, this
+  function must be called again with Z_FINISH and more output space (updated
+  avail_out) but no more input data, until it returns with Z_STREAM_END or an
+  error.  After deflate has returned Z_STREAM_END, the only possible operations
+  on the stream are deflateReset or deflateEnd.
+
+    Z_FINISH can be used in the first deflate call after deflateInit if all the
+  compression is to be done in a single step.  In order to complete in one
+  call, avail_out must be at least the value returned by deflateBound (see
+  below).  Then deflate is guaranteed to return Z_STREAM_END.  If not enough
+  output space is provided, deflate will not return Z_STREAM_END, and it must
+  be called again as described above.
+
+    deflate() sets strm->adler to the Adler-32 checksum of all input read
+  so far (that is, total_in bytes).  If a gzip stream is being generated, then
+  strm->adler will be the CRC-32 checksum of the input read so far.  (See
+  deflateInit2 below.)
 
     deflate() may update strm->data_type if it can make a good guess about
-  the input data type (Z_BINARY or Z_TEXT).  In doubt, the data is considered
-  binary.  This field is only for information purposes and does not affect the
-  compression algorithm in any manner.
+  the input data type (Z_BINARY or Z_TEXT).  If in doubt, the data is
+  considered binary.  This field is only for information purposes and does not
+  affect the compression algorithm in any manner.
 
     deflate() returns Z_OK if some progress has been made (more input
   processed or more output produced), Z_STREAM_END if all input has been
   consumed and all output has been produced (only when flush is set to
   Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
-  if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
-  (for example avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not
-  fatal, and deflate() can be called again with more input and more output
-  space to continue compressing.
+  if next_in or next_out was Z_NULL or the state was inadvertently written over
+  by the application), or Z_BUF_ERROR if no progress is possible (for example
+  avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not fatal, and
+  deflate() can be called again with more input and more output space to
+  continue compressing.
 */
 
 
@@ -369,23 +379,21 @@ ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
 
      Initializes the internal stream state for decompression.  The fields
    next_in, avail_in, zalloc, zfree and opaque must be initialized before by
-   the caller.  If next_in is not Z_NULL and avail_in is large enough (the
-   exact value depends on the compression method), inflateInit determines the
-   compression method from the zlib header and allocates all data structures
-   accordingly; otherwise the allocation will be deferred to the first call of
-   inflate.  If zalloc and zfree are set to Z_NULL, inflateInit updates them to
-   use default allocation functions.
+   the caller.  In the current version of inflate, the provided input is not
+   read or consumed.  The allocation of a sliding window will be deferred to
+   the first call of inflate (if the decompression does not complete on the
+   first call).  If zalloc and zfree are set to Z_NULL, inflateInit updates
+   them to use default allocation functions.
 
      inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
    memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
    version assumed by the caller, or Z_STREAM_ERROR if the parameters are
    invalid, such as a null pointer to the structure.  msg is set to null if
-   there is no error message.  inflateInit does not perform any decompression
-   apart from possibly reading the zlib header if present: actual decompression
-   will be done by inflate().  (So next_in and avail_in may be modified, but
-   next_out and avail_out are unused and unchanged.) The current implementation
-   of inflateInit() does not process any header information -- that is deferred
-   until inflate() is called.
+   there is no error message.  inflateInit does not perform any decompression.
+   Actual decompression will be done by inflate().  So next_in, and avail_in,
+   next_out, and avail_out are unused and unchanged.  The current
+   implementation of inflateInit() does not process any header information --
+   that is deferred until inflate() is called.
 */
 
 
@@ -401,17 +409,20 @@ ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
 
   - Decompress more input starting at next_in and update next_in and avail_in
     accordingly.  If not all input can be processed (because there is not
-    enough room in the output buffer), next_in is updated and processing will
-    resume at this point for the next call of inflate().
+    enough room in the output buffer), then next_in and avail_in are updated
+    accordingly, and processing will resume at this point for the next call of
+    inflate().
 
-  - Provide more output starting at next_out and update next_out and avail_out
+  - Generate more output starting at next_out and update next_out and avail_out
     accordingly.  inflate() provides as much output as possible, until there is
     no more input data or no more space in the output buffer (see below about
     the flush parameter).
 
     Before the call of inflate(), the application should ensure that at least
   one of the actions is possible, by providing more input and/or consuming more
-  output, and updating the next_* and avail_* values accordingly.  The
+  output, and updating the next_* and avail_* values accordingly.  If the
+  caller of inflate() does not provide both available input and available
+  output space, it is possible that there will be no progress made.  The
   application can consume the uncompressed output when it wants, for example
   when the output buffer is full (avail_out == 0), or after each call of
   inflate().  If inflate returns Z_OK and with zero avail_out, it must be
@@ -428,7 +439,7 @@ ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
   gets to the end of that block, or when it runs out of data.
 
     The Z_BLOCK option assists in appending to or combining deflate streams.
-  Also to assist in this, on return inflate() will set strm->data_type to the
+  To assist in this, on return inflate() always sets strm->data_type to the
   number of unused bits in the last byte taken from strm->next_in, plus 64 if
   inflate() is currently decoding the last block in the deflate stream, plus
   128 if inflate() returned immediately after decoding an end-of-block code or
@@ -454,7 +465,7 @@ ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
   this case all pending input is processed and all pending output is flushed;
   avail_out must be large enough to hold all of the uncompressed data for the
   operation to complete.  (The size of the uncompressed data may have been
-  saved by the compressor for this purpose.) The use of Z_FINISH is not
+  saved by the compressor for this purpose.)  The use of Z_FINISH is not
   required to perform an inflation in one step.  However it may be used to
   inform inflate that a faster approach can be used for the single inflate()
   call.  Z_FINISH also informs inflate to not maintain a sliding window if the
@@ -476,32 +487,33 @@ ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
   chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
   strm->adler to the Adler-32 checksum of all output produced so far (that is,
   total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
-  below.  At the end of the stream, inflate() checks that its computed adler32
+  below.  At the end of the stream, inflate() checks that its computed Adler-32
   checksum is equal to that saved by the compressor and returns Z_STREAM_END
   only if the checksum is correct.
 
     inflate() can decompress and check either zlib-wrapped or gzip-wrapped
   deflate data.  The header type is detected automatically, if requested when
   initializing with inflateInit2().  Any information contained in the gzip
-  header is not retained, so applications that need that information should
-  instead use raw inflate, see inflateInit2() below, or inflateBack() and
-  perform their own processing of the gzip header and trailer.  When processing
+  header is not retained unless inflateGetHeader() is used.  When processing
   gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
-  producted so far.  The CRC-32 is checked against the gzip trailer.
+  produced so far.  The CRC-32 is checked against the gzip trailer, as is the
+  uncompressed length, modulo 2^32.
 
     inflate() returns Z_OK if some progress has been made (more input processed
   or more output produced), Z_STREAM_END if the end of the compressed data has
   been reached and all uncompressed output has been produced, Z_NEED_DICT if a
   preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
   corrupted (input stream not conforming to the zlib format or incorrect check
-  value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
-  next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
-  Z_BUF_ERROR if no progress is possible or if there was not enough room in the
-  output buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and
+  value, in which case strm->msg points to a string with a more specific
+  error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
+  next_in or next_out was Z_NULL, or the state was inadvertently written over
+  by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
+  if no progress was possible or if there was not enough room in the output
+  buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and
   inflate() can be called again with more input and more output space to
   continue decompressing.  If Z_DATA_ERROR is returned, the application may
   then call inflateSync() to look for a good compression block if a partial
-  recovery of the data is desired.
+  recovery of the data is to be attempted.
 */
 
 
@@ -511,9 +523,8 @@ ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
    This function discards any unprocessed input and does not flush any pending
    output.
 
-     inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
-   was inconsistent.  In the error case, msg may be set but then points to a
-   static string (which must not be deallocated).
+     inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state
+   was inconsistent.
 */
 
 
@@ -544,16 +555,29 @@ ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
    compression at the expense of memory usage.  The default value is 15 if
    deflateInit is used instead.
 
+     For the current implementation of deflate(), a windowBits value of 8 (a
+   window size of 256 bytes) is not supported.  As a result, a request for 8
+   will result in 9 (a 512-byte window).  In that case, providing 8 to
+   inflateInit2() will result in an error when the zlib header with 9 is
+   checked against the initialization of inflate().  The remedy is to not use 8
+   with deflateInit2() with this initialization, or at least in that case use 9
+   with inflateInit2().
+
      windowBits can also be -8..-15 for raw deflate.  In this case, -windowBits
    determines the window size.  deflate() will then generate raw deflate data
-   with no zlib header or trailer, and will not compute an adler32 check value.
+   with no zlib header or trailer, and will not compute a check value.
 
      windowBits can also be greater than 15 for optional gzip encoding.  Add
    16 to windowBits to write a simple gzip header and trailer around the
    compressed data instead of a zlib wrapper.  The gzip header will have no
    file name, no extra data, no comment, no modification time (set to zero), no
-   header crc, and the operating system will be set to 255 (unknown).  If a
-   gzip stream is being written, strm->adler is a crc32 instead of an adler32.
+   header crc, and the operating system will be set to the appropriate value,
+   if the operating system was determined at compile time.  If a gzip stream is
+   being written, strm->adler is a CRC-32 instead of an Adler-32.
+
+     For raw deflate or gzip encoding, a request for a 256-byte window is
+   rejected as invalid, since only the zlib header provides a means of
+   transmitting the window size to the decompressor.
 
      The memLevel parameter specifies how much memory should be allocated
    for the internal compression state.  memLevel=1 uses minimum memory but is
@@ -614,12 +638,12 @@ ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
    addition, the current implementation of deflate will use at most the window
    size minus 262 bytes of the provided dictionary.
 
-     Upon return of this function, strm->adler is set to the adler32 value
+     Upon return of this function, strm->adler is set to the Adler-32 value
    of the dictionary; the decompressor may later use this value to determine
-   which dictionary has been used by the compressor.  (The adler32 value
+   which dictionary has been used by the compressor.  (The Adler-32 value
    applies to the whole dictionary even if only a subset of the dictionary is
    actually used by the compressor.) If a raw deflate was requested, then the
-   adler32 value is not computed and strm->adler is not set.
+   Adler-32 value is not computed and strm->adler is not set.
 
      deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
    parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
@@ -628,6 +652,28 @@ ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
    not perform any compression: this will be done by deflate().
 */
 
+ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
+                                             Bytef *dictionary,
+                                             uInt  *dictLength));
+/*
+     Returns the sliding dictionary being maintained by deflate.  dictLength is
+   set to the number of bytes in the dictionary, and that many bytes are copied
+   to dictionary.  dictionary must have enough space, where 32768 bytes is
+   always enough.  If deflateGetDictionary() is called with dictionary equal to
+   Z_NULL, then only the dictionary length is returned, and nothing is copied.
+   Similary, if dictLength is Z_NULL, then it is not set.
+
+     deflateGetDictionary() may return a length less than the window size, even
+   when more than the window size in input has been provided. It may return up
+   to 258 bytes less in that case, due to how zlib's implementation of deflate
+   manages the sliding window and lookahead for matches, where matches can be
+   up to 258 bytes long. If the application needs the last window-size bytes of
+   input, then that would need to be saved by the application outside of zlib.
+
+     deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+   stream state is inconsistent.
+*/
+
 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
                                     z_streamp source));
 /*
@@ -648,10 +694,10 @@ ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
 
 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
 /*
-     This function is equivalent to deflateEnd followed by deflateInit,
-   but does not free and reallocate all the internal compression state.  The
-   stream will keep the same compression level and any other attributes that
-   may have been set by deflateInit2.
+     This function is equivalent to deflateEnd followed by deflateInit, but
+   does not free and reallocate the internal compression state.  The stream
+   will leave the compression level and any other attributes that may have been
+   set unchanged.
 
      deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
    stream state was inconsistent (such as zalloc or state being Z_NULL).
@@ -662,20 +708,36 @@ ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
                                       int strategy));
 /*
      Dynamically update the compression level and compression strategy.  The
-   interpretation of level and strategy is as in deflateInit2.  This can be
+   interpretation of level and strategy is as in deflateInit2().  This can be
    used to switch between compression and straight copy of the input data, or
    to switch to a different kind of input data requiring a different strategy.
-   If the compression level is changed, the input available so far is
-   compressed with the old level (and may be flushed); the new level will take
-   effect only at the next call of deflate().
-
-     Before the call of deflateParams, the stream state must be set as for
-   a call of deflate(), since the currently available input may have to be
-   compressed and flushed.  In particular, strm->avail_out must be non-zero.
-
-     deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
-   stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
-   strm->avail_out was zero.
+   If the compression approach (which is a function of the level) or the
+   strategy is changed, and if any input has been consumed in a previous
+   deflate() call, then the input available so far is compressed with the old
+   level and strategy using deflate(strm, Z_BLOCK).  There are three approaches
+   for the compression levels 0, 1..3, and 4..9 respectively.  The new level
+   and strategy will take effect at the next call of deflate().
+
+     If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
+   not have enough output space to complete, then the parameter change will not
+   take effect.  In this case, deflateParams() can be called again with the
+   same parameters and more output space to try again.
+
+     In order to assure a change in the parameters on the first try, the
+   deflate stream should be flushed using deflate() with Z_BLOCK or other flush
+   request until strm.avail_out is not zero, before calling deflateParams().
+   Then no more input data should be provided before the deflateParams() call.
+   If this is done, the old level and strategy will be applied to the data
+   compressed before deflateParams(), and the new level and strategy will be
+   applied to the the data compressed after deflateParams().
+
+     deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
+   state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
+   there was not enough output space to complete the compression of the
+   available input data before a change in the strategy or approach.  Note that
+   in the case of a Z_BUF_ERROR, the parameters are not changed.  A return
+   value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
+   retried with more output space.
 */
 
 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
@@ -793,7 +855,7 @@ ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
    is for use with other formats that use the deflate compressed data format
    such as zip.  Those formats provide their own check values.  If a custom
    format is developed using the raw deflate format for compressed data, it is
-   recommended that a check value such as an adler32 or a crc32 be applied to
+   recommended that a check value such as an Adler-32 or a CRC-32 be applied to
    the uncompressed data as is done in the zlib, gzip, and zip formats.  For
    most applications, the zlib format should be used as is.  Note that comments
    above on the use in deflateInit2() applies to the magnitude of windowBits.
@@ -802,7 +864,10 @@ ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
    32 to windowBits to enable zlib and gzip decoding with automatic header
    detection, or add 16 to decode only the gzip format (the zlib format will
    return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is a
-   crc32 instead of an adler32.
+   CRC-32 instead of an Adler-32.  Unlike the gunzip utility and gzread() (see
+   below), inflate() will not automatically decode concatenated gzip streams.
+   inflate() will return Z_STREAM_END at the end of the gzip stream.  The state
+   would need to be reset to continue decoding a subsequent gzip stream.
 
      inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
    memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
@@ -823,7 +888,7 @@ ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
      Initializes the decompression dictionary from the given uncompressed byte
    sequence.  This function must be called immediately after a call of inflate,
    if that call returned Z_NEED_DICT.  The dictionary chosen by the compressor
-   can be determined from the adler32 value returned by that call of inflate.
+   can be determined from the Adler-32 value returned by that call of inflate.
    The compressor and decompressor must use exactly the same dictionary (see
    deflateSetDictionary).  For raw inflate, this function can be called at any
    time to set the dictionary.  If the provided dictionary is smaller than the
@@ -834,7 +899,7 @@ ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
      inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
    parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
    inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
-   expected one (incorrect adler32 value).  inflateSetDictionary does not
+   expected one (incorrect Adler-32 value).  inflateSetDictionary does not
    perform any decompression: this will be done by subsequent calls of
    inflate().
 */
@@ -892,7 +957,7 @@ ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
 /*
      This function is equivalent to inflateEnd followed by inflateInit,
-   but does not free and reallocate all the internal decompression state.  The
+   but does not free and reallocate the internal decompression state.  The
    stream will keep attributes that may have been set by inflateInit2.
 
      inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
@@ -904,7 +969,9 @@ ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
 /*
      This function is the same as inflateReset, but it also permits changing
    the wrap and window size requests.  The windowBits parameter is interpreted
-   the same as it is for inflateInit2.
+   the same as it is for inflateInit2.  If the window size is changed, then the
+   memory allocated for the window is freed, and the window will be reallocated
+   by inflate() if needed.
 
      inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
    stream state was inconsistent (such as zalloc or state being Z_NULL), or if
@@ -956,7 +1023,7 @@ ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
    location in the input stream can be determined from avail_in and data_type
    as noted in the description for the Z_BLOCK flush parameter for inflate.
 
-     inflateMark returns the value noted above or -1 << 16 if the provided
+     inflateMark returns the value noted above, or -65536 if the provided
    source stream state was inconsistent.
 */
 
@@ -1048,9 +1115,9 @@ ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
    This routine would normally be used in a utility that reads zip or gzip
    files and writes out uncompressed files.  The utility would decode the
    header and process the trailer on its own, hence this routine expects only
-   the raw deflate stream to decompress.  This is different from the normal
-   behavior of inflate(), which expects either a zlib or gzip header and
-   trailer around the deflate stream.
+   the raw deflate stream to decompress.  This is different from the default
+   behavior of inflate(), which expects a zlib header and trailer around the
+   deflate stream.
 
      inflateBack() uses two subroutines supplied by the caller that are then
    called by inflateBack() for input and output.  inflateBack() calls those
@@ -1059,12 +1126,12 @@ ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
    parameters and return types are defined above in the in_func and out_func
    typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
    number of bytes of provided input, and a pointer to that input in buf.  If
-   there is no input available, in() must return zero--buf is ignored in that
-   case--and inflateBack() will return a buffer error.  inflateBack() will call
-   out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].  out()
-   should return zero on success, or non-zero on failure.  If out() returns
-   non-zero, inflateBack() will return with an error.  Neither in() nor out()
-   are permitted to change the contents of the window provided to
+   there is no input available, in() must return zero -- buf is ignored in that
+   case -- and inflateBack() will return a buffer error.  inflateBack() will
+   call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
+   out() should return zero on success, or non-zero on failure.  If out()
+   returns non-zero, inflateBack() will return with an error.  Neither in() nor
+   out() are permitted to change the contents of the window provided to
    inflateBackInit(), which is also the buffer that out() uses to write from.
    The length written by out() will be at most the window size.  Any non-zero
    amount of input may be provided by in().
@@ -1092,7 +1159,7 @@ ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
    using strm->next_in which will be Z_NULL only if in() returned an error.  If
    strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
    non-zero.  (in() will always be called before out(), so strm->next_in is
-   assured to be defined if out() returns non-zero.) Note that inflateBack()
+   assured to be defined if out() returns non-zero.)  Note that inflateBack()
    cannot return Z_OK.
 */
 
@@ -1114,7 +1181,7 @@ ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
      7.6: size of z_off_t
 
     Compiler, assembler, and debug options:
-     8: DEBUG
+     8: ZLIB_DEBUG
      9: ASMV or ASMINF -- use ASM code
      10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
      11: 0 (reserved)
@@ -1164,7 +1231,8 @@ ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
    the byte length of the source buffer.  Upon entry, destLen is the total size
    of the destination buffer, which must be at least the value returned by
    compressBound(sourceLen).  Upon exit, destLen is the actual size of the
-   compressed buffer.
+   compressed data.  compress() is equivalent to compress2() with a level
+   parameter of Z_DEFAULT_COMPRESSION.
 
      compress returns Z_OK if success, Z_MEM_ERROR if there was not
    enough memory, Z_BUF_ERROR if there was not enough room in the output
@@ -1180,7 +1248,7 @@ ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
    length of the source buffer.  Upon entry, destLen is the total size of the
    destination buffer, which must be at least the value returned by
    compressBound(sourceLen).  Upon exit, destLen is the actual size of the
-   compressed buffer.
+   compressed data.
 
      compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
    memory, Z_BUF_ERROR if there was not enough room in the output buffer,
@@ -1203,7 +1271,7 @@ ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
    uncompressed data.  (The size of the uncompressed data must have been saved
    previously by the compressor and transmitted to the decompressor by some
    mechanism outside the scope of this compression library.) Upon exit, destLen
-   is the actual size of the uncompressed buffer.
+   is the actual size of the uncompressed data.
 
      uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
    enough memory, Z_BUF_ERROR if there was not enough room in the output
@@ -1212,6 +1280,14 @@ ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
    buffer with the uncompressed data up to that point.
 */
 
+ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest,   uLongf *destLen,
+                                    const Bytef *source, uLong *sourceLen));
+/*
+     Same as uncompress, except that sourceLen is a pointer, where the
+   length of the source is *sourceLen.  On return, *sourceLen is the number of
+   source bytes consumed.
+*/
+
                         /* gzip file access functions */
 
 /*
@@ -1290,10 +1366,9 @@ ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
    default buffer size is 8192 bytes.  This function must be called after
    gzopen() or gzdopen(), and before any other calls that read or write the
    file.  The buffer memory allocation is always deferred to the first read or
-   write.  Two buffers are allocated, either both of the specified size when
-   writing, or one of the specified size and the other twice that size when
-   reading.  A larger buffer size of, for example, 64K or 128K bytes will
-   noticeably increase the speed of decompression (reading).
+   write.  Three times that size in buffer space is allocated.  A larger buffer
+   size of, for example, 64K or 128K bytes will noticeably increase the speed
+   of decompression (reading).
 
      The new buffer size also affects the maximum length for gzprintf().
 
@@ -1304,10 +1379,12 @@ ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
 /*
      Dynamically update the compression level or strategy.  See the description
-   of deflateInit2 for the meaning of these parameters.
+   of deflateInit2 for the meaning of these parameters.  Previously provided
+   data is flushed before the parameter change.
 
-     gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
-   opened for writing.
+     gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
+   opened for writing, Z_ERRNO if there is an error writing the flushed data,
+   or Z_MEM_ERROR if there is a memory allocation error.
 */
 
 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
@@ -1335,7 +1412,35 @@ ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
    case.
 
      gzread returns the number of uncompressed bytes actually read, less than
-   len for end of file, or -1 for error.
+   len for end of file, or -1 for error.  If len is too large to fit in an int,
+   then nothing is read, -1 is returned, and the error state is set to
+   Z_STREAM_ERROR.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
+                                     gzFile file));
+/*
+     Read up to nitems items of size size from file to buf, otherwise operating
+   as gzread() does.  This duplicates the interface of stdio's fread(), with
+   size_t request and return types.  If the library defines size_t, then
+   z_size_t is identical to size_t.  If not, then z_size_t is an unsigned
+   integer type that can contain a pointer.
+
+     gzfread() returns the number of full items read of size size, or zero if
+   the end of the file was reached and a full item could not be read, or if
+   there was an error.  gzerror() must be consulted if zero is returned in
+   order to determine if there was an error.  If the multiplication of size and
+   nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
+   is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
+
+     In the event that the end of file is reached and only a partial item is
+   available at the end, i.e. the remaining uncompressed data length is not a
+   multiple of size, then the final partial item is nevetheless read into buf
+   and the end-of-file flag is set.  The length of the partial item read is not
+   provided, but could be inferred from the result of gztell().  This behavior
+   is the same as the behavior of fread() implementations in common libraries,
+   but it prevents the direct use of gzfread() to read a concurrently written
+   file, reseting and retrying on end-of-file, when size is not 1.
 */
 
 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
@@ -1346,19 +1451,33 @@ ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
    error.
 */
 
+ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size,
+                                      z_size_t nitems, gzFile file));
+/*
+     gzfwrite() writes nitems items of size size from buf to file, duplicating
+   the interface of stdio's fwrite(), with size_t request and return types.  If
+   the library defines size_t, then z_size_t is identical to size_t.  If not,
+   then z_size_t is an unsigned integer type that can contain a pointer.
+
+     gzfwrite() returns the number of full items written of size size, or zero
+   if there was an error.  If the multiplication of size and nitems overflows,
+   i.e. the product does not fit in a z_size_t, then nothing is written, zero
+   is returned, and the error state is set to Z_STREAM_ERROR.
+*/
+
 ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
 /*
      Converts, formats, and writes the arguments to the compressed file under
    control of the format string, as in fprintf.  gzprintf returns the number of
-   uncompressed bytes actually written, or 0 in case of error.  The number of
-   uncompressed bytes written is limited to 8191, or one less than the buffer
-   size given to gzbuffer().  The caller should assure that this limit is not
-   exceeded.  If it is exceeded, then gzprintf() will return an error (0) with
-   nothing written.  In this case, there may also be a buffer overflow with
-   unpredictable consequences, which is possible only if zlib was compiled with
-   the insecure functions sprintf() or vsprintf() because the secure snprintf()
-   or vsnprintf() functions were not available.  This can be determined using
-   zlibCompileFlags().
+   uncompressed bytes actually written, or a negative zlib error code in case
+   of error.  The number of uncompressed bytes written is limited to 8191, or
+   one less than the buffer size given to gzbuffer().  The caller should assure
+   that this limit is not exceeded.  If it is exceeded, then gzprintf() will
+   return an error (0) with nothing written.  In this case, there may also be a
+   buffer overflow with unpredictable consequences, which is possible only if
+   zlib was compiled with the insecure functions sprintf() or vsprintf()
+   because the secure snprintf() or vsnprintf() functions were not available.
+   This can be determined using zlibCompileFlags().
 */
 
 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
@@ -1418,7 +1537,7 @@ ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
      If the flush parameter is Z_FINISH, the remaining data is written and the
    gzip stream is completed in the output.  If gzwrite() is called again, a new
    gzip stream will be started in the output.  gzread() is able to read such
-   concatented gzip streams.
+   concatenated gzip streams.
 
      gzflush should be called only when strictly necessary because it will
    degrade compression if called too often.
@@ -1572,7 +1691,7 @@ ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
    return the updated checksum.  If buf is Z_NULL, this function returns the
    required initial value for the checksum.
 
-     An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
+     An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
    much faster.
 
    Usage example:
@@ -1585,6 +1704,12 @@ ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
      if (adler != original_adler) error();
 */
 
+ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf,
+                                    z_size_t len));
+/*
+     Same as adler32(), but with a size_t length.
+*/
+
 /*
 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
                                           z_off_t len2));
@@ -1614,6 +1739,12 @@ ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
      if (crc != original_crc) error();
 */
 
+ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf,
+                                  z_size_t len));
+/*
+     Same as crc32(), but with a size_t length.
+*/
+
 /*
 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
 
@@ -1644,19 +1775,35 @@ ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
                                          unsigned char FAR *window,
                                          const char *version,
                                          int stream_size));
-#define deflateInit(strm, level) \
-        deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
-#define inflateInit(strm) \
-        inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
-#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
-        deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
-                      (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
-#define inflateInit2(strm, windowBits) \
-        inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
-                      (int)sizeof(z_stream))
-#define inflateBackInit(strm, windowBits, window) \
-        inflateBackInit_((strm), (windowBits), (window), \
-                      ZLIB_VERSION, (int)sizeof(z_stream))
+#ifdef Z_PREFIX_SET
+#  define z_deflateInit(strm, level) \
+          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_inflateInit(strm) \
+          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_inflateInit2(strm, windowBits) \
+          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+                        (int)sizeof(z_stream))
+#  define z_inflateBackInit(strm, windowBits, window) \
+          inflateBackInit_((strm), (windowBits), (window), \
+                           ZLIB_VERSION, (int)sizeof(z_stream))
+#else
+#  define deflateInit(strm, level) \
+          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define inflateInit(strm) \
+          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define inflateInit2(strm, windowBits) \
+          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+                        (int)sizeof(z_stream))
+#  define inflateBackInit(strm, windowBits, window) \
+          inflateBackInit_((strm), (windowBits), (window), \
+                           ZLIB_VERSION, (int)sizeof(z_stream))
+#endif
 
 #ifndef Z_SOLO
 
@@ -1676,10 +1823,10 @@ ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));  /* backward compatibility */
 #ifdef Z_PREFIX_SET
 #  undef z_gzgetc
 #  define z_gzgetc(g) \
-          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
+          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
 #else
 #  define gzgetc(g) \
-          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
+          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
 #endif
 
 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
@@ -1737,19 +1884,16 @@ ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));  /* backward compatibility */
 
 #endif /* !Z_SOLO */
 
-/* hack for buggy compilers */
-#if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
-    struct internal_state {int dummy;};
-#endif
-
 /* undocumented functions */
 ZEXTERN const char   * ZEXPORT zError           OF((int));
 ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp));
 ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table    OF((void));
 ZEXTERN int            ZEXPORT inflateUndermine OF((z_streamp, int));
+ZEXTERN int            ZEXPORT inflateValidate OF((z_streamp, int));
+ZEXTERN unsigned long  ZEXPORT inflateCodesUsed OF ((z_streamp));
 ZEXTERN int            ZEXPORT inflateResetKeep OF((z_streamp));
 ZEXTERN int            ZEXPORT deflateResetKeep OF((z_streamp));
-#if defined(_WIN32) && !defined(Z_SOLO)
+#if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(Z_SOLO)
 ZEXTERN gzFile         ZEXPORT gzopen_w OF((const wchar_t *path,
                                             const char *mode));
 #endif
diff --git a/erts/emulator/zlib/zlib.mk b/erts/emulator/zlib/zlib.mk
index 3f0d64d250..b51b4ec8d6 100644
--- a/erts/emulator/zlib/zlib.mk
+++ b/erts/emulator/zlib/zlib.mk
@@ -52,7 +52,7 @@ ifeq ($(TYPE),gcov)
 ZLIB_CFLAGS = -O0 -fprofile-arcs -ftest-coverage $(DEBUG_CFLAGS) $(DEFS) $(THR_DEFS)
 else  # gcov
 ifeq ($(TYPE),debug)
-ZLIB_CFLAGS = $(DEBUG_CFLAGS) $(DEFS) $(THR_DEFS)
+ZLIB_CFLAGS = -DZLIB_DEBUG=1 $(DEBUG_CFLAGS) $(DEFS) $(THR_DEFS)
 else # debug
 ZLIB_CFLAGS = $(subst -O2, -O3, $(CONFIGURE_CFLAGS) $(DEFS) $(THR_DEFS))
 #ZLIB_CFLAGS=-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7
@@ -62,6 +62,9 @@ ZLIB_CFLAGS = $(subst -O2, -O3, $(CONFIGURE_CFLAGS) $(DEFS) $(THR_DEFS))
 endif # debug
 endif # gcov
 
+# Don't fail if _LFS64_LARGEFILE is undefined
+ZLIB_CFLAGS := $(filter-out -Werror=undef,$(ZLIB_CFLAGS))
+
 ifeq ($(TARGET), win32)
 $(ZLIB_LIBRARY): $(ZLIB_OBJS)
 	$(V_AR) -out:$@ $(ZLIB_OBJS)
diff --git a/erts/emulator/zlib/zutil.c b/erts/emulator/zlib/zutil.c
index 27a8af4a2b..a76c6b0c7e 100644
--- a/erts/emulator/zlib/zutil.c
+++ b/erts/emulator/zlib/zutil.c
@@ -1,33 +1,27 @@
 /* zutil.c -- target dependent utility functions for the compression library
- * Copyright (C) 1995-2005, 2010, 2011, 2012 Jean-loup Gailly.
+ * Copyright (C) 1995-2017 Jean-loup Gailly
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 /* @(#) $Id$ */
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
 #include "zutil.h"
 #ifndef Z_SOLO
 #  include "gzguts.h"
 #endif
 
-#ifndef NO_DUMMY_DECL
-struct internal_state      {int dummy;}; /* for buggy compilers */
-#endif
-
 z_const char * const z_errmsg[10] = {
-"need dictionary",     /* Z_NEED_DICT       2  */
-"stream end",          /* Z_STREAM_END      1  */
-"",                    /* Z_OK              0  */
-"file error",          /* Z_ERRNO         (-1) */
-"stream error",        /* Z_STREAM_ERROR  (-2) */
-"data error",          /* Z_DATA_ERROR    (-3) */
-"insufficient memory", /* Z_MEM_ERROR     (-4) */
-"buffer error",        /* Z_BUF_ERROR     (-5) */
-"incompatible version",/* Z_VERSION_ERROR (-6) */
-""};
+    (z_const char *)"need dictionary",     /* Z_NEED_DICT       2  */
+    (z_const char *)"stream end",          /* Z_STREAM_END      1  */
+    (z_const char *)"",                    /* Z_OK              0  */
+    (z_const char *)"file error",          /* Z_ERRNO         (-1) */
+    (z_const char *)"stream error",        /* Z_STREAM_ERROR  (-2) */
+    (z_const char *)"data error",          /* Z_DATA_ERROR    (-3) */
+    (z_const char *)"insufficient memory", /* Z_MEM_ERROR     (-4) */
+    (z_const char *)"buffer error",        /* Z_BUF_ERROR     (-5) */
+    (z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
+    (z_const char *)""
+};
 
 
 const char * ZEXPORT zlibVersion()
@@ -64,7 +58,7 @@ uLong ZEXPORT zlibCompileFlags()
     case 8:     flags += 2 << 6;        break;
     default:    flags += 3 << 6;
     }
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
     flags += 1 << 8;
 #endif
 #if defined(ASMV) || defined(ASMINF)
@@ -118,8 +112,8 @@ uLong ZEXPORT zlibCompileFlags()
     return flags;
 }
 
-#ifdef DEBUG
-
+#ifdef ZLIB_DEBUG
+#include <stdlib.h>
 #  ifndef verbose
 #    define verbose 0
 #  endif
@@ -222,9 +216,11 @@ local ptr_table table[MAX_PTR];
 
 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
 {
-    voidpf buf = opaque; /* just to make some compilers happy */
+    voidpf buf;
     ulg bsize = (ulg)items*size;
 
+    (void)opaque;
+
     /* If we allocate less than 65520 bytes, we assume that farmalloc
      * will return a usable pointer which doesn't have to be normalized.
      */
@@ -247,6 +243,9 @@ voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
 {
     int n;
+
+    (void)opaque;
+
     if (*(ush*)&ptr != 0) { /* object < 64K */
         farfree(ptr);
         return;
@@ -262,7 +261,6 @@ void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
         next_ptr--;
         return;
     }
-    ptr = opaque; /* just to make some compilers happy */
     Assert(0, "zcfree: ptr not found");
 }
 
@@ -281,13 +279,13 @@ void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
 
 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, uInt items, uInt size)
 {
-    if (opaque) opaque = 0; /* to make compiler happy */
+    (void)opaque;
     return _halloc((long)items, size);
 }
 
 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
 {
-    if (opaque) opaque = 0; /* to make compiler happy */
+    (void)opaque;
     _hfree(ptr);
 }
 
@@ -309,7 +307,7 @@ voidpf ZLIB_INTERNAL zcalloc (opaque, items, size)
     unsigned items;
     unsigned size;
 {
-    if (opaque) items += size - size; /* make compiler happy */
+    (void)opaque;
     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
                               (voidpf)calloc(items, size);
 }
@@ -318,8 +316,8 @@ void ZLIB_INTERNAL zcfree (opaque, ptr)
     voidpf opaque;
     voidpf ptr;
 {
+    (void)opaque;
     free(ptr);
-    if (opaque) return; /* make compiler happy */
 }
 
 #endif /* MY_ZCALLOC */
diff --git a/erts/emulator/zlib/zutil.h b/erts/emulator/zlib/zutil.h
index 24ab06b1cf..b079ea6a80 100644
--- a/erts/emulator/zlib/zutil.h
+++ b/erts/emulator/zlib/zutil.h
@@ -1,5 +1,5 @@
 /* zutil.h -- internal interface and configuration of the compression library
- * Copyright (C) 1995-2013 Jean-loup Gailly.
+ * Copyright (C) 1995-2016 Jean-loup Gailly, Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -36,7 +36,9 @@
 #ifndef local
 #  define local static
 #endif
-/* compile with -Dlocal if your debugger can't find static symbols */
+/* since "static" is used to mean two completely different things in C, we
+   define "local" for the non-static meaning of "static", for readability
+   (compile with -Dlocal if your debugger can't find static symbols) */
 
 typedef unsigned char  uch;
 typedef uch FAR uchf;
@@ -98,28 +100,38 @@ extern z_const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
 #endif
 
 #ifdef AMIGA
-#  define OS_CODE  0x01
+#  define OS_CODE  1
 #endif
 
 #if defined(VAXC) || defined(VMS)
-#  define OS_CODE  0x02
+#  define OS_CODE  2
 #  define F_OPEN(name, mode) \
      fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
 #endif
 
+#ifdef __370__
+#  if __TARGET_LIB__ < 0x20000000
+#    define OS_CODE 4
+#  elif __TARGET_LIB__ < 0x40000000
+#    define OS_CODE 11
+#  else
+#    define OS_CODE 8
+#  endif
+#endif
+
 #if defined(ATARI) || defined(atarist)
-#  define OS_CODE  0x05
+#  define OS_CODE  5
 #endif
 
 #ifdef OS2
-#  define OS_CODE  0x06
+#  define OS_CODE  6
 #  if defined(M_I86) && !defined(Z_SOLO)
 #    include <malloc.h>
 #  endif
 #endif
 
 #if defined(MACOS) || defined(TARGET_OS_MAC)
-#  define OS_CODE  0x07
+#  define OS_CODE  7
 #  ifndef Z_SOLO
 #    if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
 #      include <unix.h> /* for fdopen */
@@ -131,18 +143,24 @@ extern z_const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
 #  endif
 #endif
 
-#ifdef TOPS20
-#  define OS_CODE  0x0a
+#ifdef __acorn
+#  define OS_CODE 13
 #endif
 
-#ifdef WIN32
-#  ifndef __CYGWIN__  /* Cygwin is Unix, not Win32 */
-#    define OS_CODE  0x0b
-#  endif
+#if defined(WIN32) && !defined(__CYGWIN__)
+#  define OS_CODE  10
+#endif
+
+#ifdef _BEOS_
+#  define OS_CODE  16
+#endif
+
+#ifdef __TOS_OS400__
+#  define OS_CODE 18
 #endif
 
-#ifdef __50SERIES /* Prime/PRIMOS */
-#  define OS_CODE  0x0f
+#ifdef __APPLE__
+#  define OS_CODE 19
 #endif
 
 #if defined(_BEOS_) || defined(RISCOS)
@@ -177,7 +195,7 @@ extern z_const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
         /* common defaults */
 
 #ifndef OS_CODE
-#  define OS_CODE  0x03  /* assume Unix */
+#  define OS_CODE  3     /* assume Unix */
 #endif
 
 #ifndef F_OPEN
@@ -216,7 +234,7 @@ extern z_const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
 #endif
 
 /* Diagnostic functions */
-#ifdef DEBUG
+#ifdef ZLIB_DEBUG
 #  include <stdio.h>
    extern int ZLIB_INTERNAL z_verbose;
    extern void ZLIB_INTERNAL z_error OF((char *m));
diff --git a/erts/epmd/src/epmd.c b/erts/epmd/src/epmd.c
index 44e997e609..8313678b5d 100644
--- a/erts/epmd/src/epmd.c
+++ b/erts/epmd/src/epmd.c
@@ -437,6 +437,11 @@ static void usage(EpmdVars *g)
     fprintf(stderr, "        epmd -kill even if there "
 	    "are registered nodes.\n");
     fprintf(stderr, "        Also allows forced unregister (epmd -stop).\n");
+#ifdef HAVE_SYSTEMD_DAEMON
+    fprintf(stderr, "    -systemd\n");
+    fprintf(stderr, "        Wait for socket from systemd. The option makes sense\n");
+    fprintf(stderr, "        when started from .socket unit.\n");
+#endif /* HAVE_SYSTEMD_DAEMON */
     fprintf(stderr, "\nDbgExtra options\n");
     fprintf(stderr, "    -packet_timeout Seconds\n");
     fprintf(stderr, "        Set the number of seconds a connection can be\n");
@@ -462,11 +467,6 @@ static void usage(EpmdVars *g)
     fprintf(stderr, "        Forcibly unregisters a name with epmd\n");
     fprintf(stderr, "        (only allowed if -relaxed_command_check was given when \n");
     fprintf(stderr, "        epmd was started).\n");
-#ifdef HAVE_SYSTEMD_DAEMON
-    fprintf(stderr, "    -systemd\n");
-    fprintf(stderr, "        Wait for socket from systemd. The option makes sense\n");
-    fprintf(stderr, "        when started from .socket unit.\n");
-#endif /* HAVE_SYSTEMD_DAEMON */
     epmd_cleanup_exit(g,1);
 }
 
diff --git a/erts/epmd/src/epmd_srv.c b/erts/epmd/src/epmd_srv.c
index 66c10a65bc..3c6f1fbdf4 100644
--- a/erts/epmd/src/epmd_srv.c
+++ b/erts/epmd/src/epmd_srv.c
@@ -747,7 +747,7 @@ static void do_request(g, fd, s, buf, bsize)
 	    put_int16(node->creation, wbuf+2);
 	}
   
-	if (reply(g, fd, wbuf, 4) != 4)
+	if (!reply(g, fd, wbuf, 4))
 	  {
             node_unreg(g, name);
 	    dbg_tty_printf(g,1,"** failed to send ALIVE2_RESP for \"%s\"",
@@ -807,7 +807,7 @@ static void do_request(g, fd, s, buf, bsize)
 		offset += 2;
 		memcpy(wbuf + offset,node->extra,node->extralen);
 		offset += node->extralen;
-		if (reply(g, fd, wbuf, offset) != offset)
+		if (!reply(g, fd, wbuf, offset))
 		  {
 		    dbg_tty_printf(g,1,"** failed to send PORT2_RESP (ok) for \"%s\"",name);
 		    return;
@@ -817,7 +817,7 @@ static void do_request(g, fd, s, buf, bsize)
 	    }
 	}
 	wbuf[1] = 1; /* error */
-	if (reply(g, fd, wbuf, 2) != 2)
+	if (!reply(g, fd, wbuf, 2))
 	  {
 	    dbg_tty_printf(g,1,"** failed to send PORT2_RESP (error) for \"%s\"",name);
 	    return;
@@ -835,7 +835,7 @@ static void do_request(g, fd, s, buf, bsize)
 	i = htonl(g->port);
 	memcpy(wbuf,&i,4);
 
-	if (reply(g, fd,wbuf,4) != 4)
+	if (!reply(g, fd,wbuf,4))
 	  {
 	    dbg_tty_printf(g,1,"failed to send NAMES_RESP");
 	    return;
@@ -856,7 +856,7 @@ static void do_request(g, fd, s, buf, bsize)
 	    if (r < 0)
 		goto failed_names_resp;
 	    len += r;
-	    if (reply(g, fd, wbuf, len) != len)
+	    if (!reply(g, fd, wbuf, len))
 	      {
 	      failed_names_resp:
 		dbg_tty_printf(g,1,"failed to send NAMES_RESP");
@@ -878,7 +878,7 @@ static void do_request(g, fd, s, buf, bsize)
 
 	i = htonl(g->port);
 	memcpy(wbuf,&i,4);
-	if (reply(g, fd,wbuf,4) != 4)
+	if (!reply(g, fd,wbuf,4))
 	  {
 	    dbg_tty_printf(g,1,"failed to send DUMP_RESP");
 	    return;
@@ -899,7 +899,7 @@ static void do_request(g, fd, s, buf, bsize)
 	      if (r < 0)
 		  goto failed_dump_resp;
 	      len += r + 1;
-	      if (reply(g, fd,wbuf,len) != len)
+	      if (!reply(g, fd,wbuf,len))
 	      {
 	      failed_dump_resp:
 		dbg_tty_printf(g,1,"failed to send DUMP_RESP");
@@ -922,7 +922,7 @@ static void do_request(g, fd, s, buf, bsize)
 	      if (r < 0)
 		  goto failed_dump_resp2;
 	      len += r + 1;
-	      if (reply(g, fd,wbuf,len) != len)
+	      if (!reply(g, fd,wbuf,len))
 	      {
 	      failed_dump_resp2:
 		dbg_tty_printf(g,1,"failed to send DUMP_RESP");
@@ -942,12 +942,12 @@ static void do_request(g, fd, s, buf, bsize)
 
       if (!g->brutal_kill && (g->nodes.reg != NULL)) {
 	  dbg_printf(g,0,"Disallowed KILL_REQ, live nodes");
-	  if (reply(g, fd,"NO",2) != 2)
+	  if (!reply(g, fd,"NO",2))
 	      dbg_printf(g,0,"failed to send reply to KILL_REQ");
 	  return;
       }
 
-      if (reply(g, fd,"OK",2) != 2)
+      if (!reply(g, fd,"OK",2))
 	dbg_printf(g,0,"failed to send reply to KILL_REQ");
       dbg_tty_printf(g,1,"epmd killed");
       conn_close_fd(g,fd);	/* We never return to caller so close here */
@@ -977,7 +977,7 @@ static void do_request(g, fd, s, buf, bsize)
 
 	if ((node_fd = node_unreg(g,name)) < 0)
 	  {
-	    if (reply(g, fd,"NOEXIST",7) != 7)
+	    if (!reply(g, fd,"NOEXIST",7))
 	      {
 		dbg_tty_printf(g,1,"failed to send STOP_RESP NOEXIST");
 		return;
@@ -988,7 +988,7 @@ static void do_request(g, fd, s, buf, bsize)
 	conn_close_fd(g,node_fd);
 	dbg_tty_printf(g,1,"epmd connection stopped");
 
-	if (reply(g, fd,"STOPPED",7) != 7)
+	if (!reply(g, fd,"STOPPED",7))
 	  {
 	    dbg_tty_printf(g,1,"failed to send STOP_RESP STOPPED");
 	    return;
@@ -1448,7 +1448,9 @@ static time_t current_time(EpmdVars *g)
 
 static int reply(EpmdVars *g,int fd,char *buf,int len)
 {
-  int val;
+  char* p = buf;
+  int nbytes = len;
+  int val, ret;
 
   if (len < 0)
     {
@@ -1459,15 +1461,27 @@ static int reply(EpmdVars *g,int fd,char *buf,int len)
   if (g->delay_write)		/* Test of busy server */
     sleep(g->delay_write);
 
-  val = write(fd,buf,len);
-  if (val < 0)
-    dbg_perror(g,"error in write");
-  else if (val != len)
-    dbg_printf(g,0,"could only send %d bytes out of %d to fd %d",val,len,fd);
+  for (;;) {
+      val = write(fd, p, nbytes);
+      if (val == nbytes) {
+          ret = 1;
+          break;
+      }
+      if (val < 0) {
+          if (errno == EINTR)
+              continue;
+          dbg_perror(g,"error in write, errno=%d", errno);
+          ret = 0;
+          break;
+      }
+      dbg_printf(g,0,"could only send %d bytes out of %d to fd %d",val,nbytes,fd);
+      p += val;
+      nbytes -= val;
+  }
 
   dbg_print_buf(g,buf,len);
 
-  return val;
+  return ret;
 }
       
 
diff --git a/erts/etc/common/erlexec.c b/erts/etc/common/erlexec.c
index 0cb01fd4ef..477a501876 100644
--- a/erts/etc/common/erlexec.c
+++ b/erts/etc/common/erlexec.c
@@ -255,7 +255,9 @@ static char* key_val_name = ERLANG_VERSION; /* Used by the registry
 					   * access functions.
 					   */
 static char* boot_script = NULL; /* used by option -start_erl and -boot */
-static char* config_script = NULL; /* used by option -start_erl and -config */
+static char** config_scripts = NULL; /* used by option -start_erl and -config */
+static int config_script_cnt = 0;
+static int got_start_erl = 0;
 
 static HANDLE this_module_handle;
 static int run_werl;
@@ -392,6 +394,22 @@ add_extra_suffixes(char *prog)
 }
 
 #ifdef __WIN32__
+static void add_boot_config(void)
+{
+    int i;
+    if (boot_script)
+	add_args("-boot", boot_script, NULL);
+    for (i = 0; i < config_script_cnt; i++) {
+        add_args("-config", config_scripts[i], NULL);
+    }
+}
+# define ADD_BOOT_CONFIG add_boot_config()
+#else
+# define ADD_BOOT_CONFIG
+#endif
+
+
+#ifdef __WIN32__
 __declspec(dllexport) int win_erlexec(int argc, char **argv, HANDLE module, int windowed)
 #else
 int main(int argc, char **argv)
@@ -408,7 +426,6 @@ int main(int argc, char **argv)
     int process_args = 1;
     int print_args_exit = 0;
     int print_qouted_cmd_exit = 0;
-    erts_cpu_info_t *cpuinfo = NULL;
     char* emu_name;
 
 #ifdef __WIN32__
@@ -467,8 +484,6 @@ int main(int argc, char **argv)
     /*
      * Construct the path of the executable.
      */
-    cpuinfo = erts_cpu_info_create();
-
 #if defined(__WIN32__) && defined(WIN32_ALWAYS_DEBUG)
     emu_type = "debug";
 #endif
@@ -526,9 +541,6 @@ int main(int argc, char **argv)
 	i++;
     }
 
-    erts_cpu_info_destroy(cpuinfo);
-    cpuinfo = NULL;
-
     if (malloc_lib) {
 	if (strcmp(malloc_lib, "libc") != 0)
 	    usage("+MYm");
@@ -587,16 +599,6 @@ int main(int argc, char **argv)
     
     i = 1;
 
-#ifdef __WIN32__
-#define ADD_BOOT_CONFIG					\
-    if (boot_script)					\
-	add_args("-boot", boot_script, NULL);		\
-    if (config_script)					\
-	add_args("-config", config_script, NULL);
-#else
-#define ADD_BOOT_CONFIG
-#endif
-
     get_home();
     add_args("-home", home, NULL);
 
@@ -616,7 +618,9 @@ int main(int argc, char **argv)
 		case 'b':
 		    if (strcmp(argv[i], "-boot") == 0) {
 			if (boot_script)
-			    error("Conflicting -start_erl and -boot options");
+			    error("Conflicting -boot options");
+                        if (got_start_erl)
+                            error("Conflicting -start_erl and -boot options");
 			if (i+1 >= argc)
 			    usage("-boot");
 			boot_script = strsave(argv[i+1]);
@@ -640,11 +644,14 @@ int main(int argc, char **argv)
 		    }
 #ifdef __WIN32__
 		    else if (strcmp(argv[i], "-config") == 0){
-			if (config_script)
+			if (got_start_erl)
 			    error("Conflicting -start_erl and -config options");
 			if (i+1 >= argc)
 			    usage("-config");
-			config_script = strsave(argv[i+1]);
+                        config_script_cnt++;
+                        config_scripts = erealloc(config_scripts,
+                                                  config_script_cnt * sizeof(char*));
+			config_scripts[config_script_cnt-1] = strsave(argv[i+1]);
 			i++;
 		    }
 #endif
@@ -662,15 +669,6 @@ int main(int argc, char **argv)
 		    }
 		    break;
 
-		  case 'i':
-		    if (strcmp(argv[i], "-instr") == 0) {
-			add_Eargs("-Mim");
-			add_Eargs("true");
-		    }
-		    else
-			add_arg(argv[i]);
-		    break;
-
 		  case 'e':
 		    if (strcmp(argv[i], "-extra") == 0) {
 			process_args = 0;
@@ -819,10 +817,8 @@ int main(int argc, char **argv)
 
 	      case '+':
 		switch (argv[i][1]) {
-		  case '#':
 		  case 'a':
 		  case 'A':
-		  case 'b':
 		  case 'C':
 		  case 'e':
 		  case 'i':
@@ -1388,6 +1384,7 @@ strsave(char* string)
 
 static void get_start_erl_data(char *file)
 {
+    static char* a_config_script;
     int fp;
     char tmpbuffer[512];
     char start_erl_data[512];
@@ -1398,7 +1395,7 @@ static void get_start_erl_data(char *file)
     char* tprogname;
     if (boot_script) 
 	error("Conflicting -start_erl and -boot options");
-    if (config_script)
+    if (config_scripts)
 	error("Conflicting -start_erl and -config options");
     env = get_env("RELDIR");
     if (env)
@@ -1448,10 +1445,13 @@ static void get_start_erl_data(char *file)
     erts_snprintf(progname,strlen(tprogname) + 20,"%s -start_erl",tprogname);
 
     boot_script = emalloc(512);
-    config_script = emalloc(512);
+    a_config_script = emalloc(512);
     erts_snprintf(boot_script, 512, "%s/%s/start", reldir, otpstring);
-    erts_snprintf(config_script, 512, "%s/%s/sys", reldir, otpstring);
+    erts_snprintf(a_config_script, 512, "%s/%s/sys", reldir, otpstring);
+    config_scripts = &a_config_script;
+    config_script_cnt = 1;
        
+    got_start_erl = 1;
 }
 
 
@@ -1690,9 +1690,9 @@ static char **build_args_from_string(char *string)
     for(;;) {
 	switch (state) {
 	case Start:
-	    if (!*p) 
+	    if (!*p)
 		goto done;
-	    if (argc >= alloced - 1) { /* Make room for extra NULL */
+	    if (argc >= alloced - 2) { /* Make room for extra NULL and "--" */
 		argv = erealloc(argv, (alloced += 10) * sizeof(char *));
 	    }
 	    cur_s = argc + argv;
@@ -1781,11 +1781,14 @@ static char **build_args_from_string(char *string)
 	}
     }
 done:
-    argv[argc] = NULL; /* Sure to be large enough */
     if (!argc) {
 	efree(argv);
 	return NULL;
     }
+    argv[argc++] = "--"; /* Add a -- separator in order
+                            for different from different environments
+                            to effect each other */
+    argv[argc++] = NULL; /* Sure to be large enough */
     return argv;
 #undef ENSURE
 }
@@ -2036,11 +2039,13 @@ initial_argv_massage(int *argc, char ***argv)
     argv_buf ab = {0}, xab = {0};
     int ix, vix, ac;
     char **av;
+    char *sep = "--";
     struct {
 	int argc;
 	char **argv;
     } avv[] = {{INT_MAX, NULL}, {INT_MAX, NULL}, {INT_MAX, NULL},
-	       {INT_MAX, NULL}, {INT_MAX, NULL}, {INT_MAX, NULL}};
+	       {INT_MAX, NULL}, {INT_MAX, NULL},
+               {INT_MAX, NULL}, {INT_MAX, NULL}};
     /*
      * The environment flag containing OTP release is intentionally
      * undocumented and intended for OTP internal use only.
@@ -2060,6 +2065,8 @@ initial_argv_massage(int *argc, char ***argv)
     if (*argc > 1) {
 	avv[vix].argc = *argc - 1;
 	avv[vix++].argv = &(*argv)[1];
+        avv[vix].argc = 1;
+        avv[vix++].argv = &sep;
     }
 
     av = build_args_from_env("ERL_FLAGS");
diff --git a/erts/etc/common/heart.c b/erts/etc/common/heart.c
index bd218ff725..bb843a616b 100644
--- a/erts/etc/common/heart.c
+++ b/erts/etc/common/heart.c
@@ -500,7 +500,7 @@ message_loop(erlin_fd, erlout_fd)
 
 #if defined(__WIN32__)
 static void 
-kill_old_erlang(void){
+kill_old_erlang(int reason){
     HANDLE erlh;
     DWORD exit_code;
     char* envvar = NULL;
@@ -536,7 +536,8 @@ kill_old_erlang(void){
 }
 #else
 static void 
-kill_old_erlang(void){
+kill_old_erlang(int reason)
+{
     pid_t pid;
     int i, res;
     int sig = SIGKILL;
@@ -546,14 +547,25 @@ kill_old_erlang(void){
     if (envvar && strcmp(envvar, "TRUE") == 0)
       return;
 
-    envvar = get_env(HEART_KILL_SIGNAL);
-    if (envvar && strcmp(envvar, "SIGABRT") == 0) {
-        print_error("kill signal SIGABRT requested");
-        sig = SIGABRT;
-    }
-
     if(heart_beat_kill_pid != 0){
-	pid = (pid_t) heart_beat_kill_pid;
+        pid = (pid_t) heart_beat_kill_pid;
+        if (reason == R_CLOSED) {
+            print_error("Wait 5 seconds for Erlang to terminate nicely");
+            for (i=0; i < 5; ++i) {
+                res = kill(pid, 0); /* check if alive */
+                if (res < 0 && errno == ESRCH)
+                    return;
+                sleep(1);
+            }
+            print_error("Erlang still alive, kill it");
+        }
+
+        envvar = get_env(HEART_KILL_SIGNAL);
+        if (envvar && strcmp(envvar, "SIGABRT") == 0) {
+            print_error("kill signal SIGABRT requested");
+            sig = SIGABRT;
+        }
+
 	res = kill(pid,sig);
 	for(i=0; i < 5 && res == 0; ++i){
 	    sleep(1);
@@ -677,7 +689,7 @@ do_terminate(int erlin_fd, int reason) {
 	    if(!command)
 		print_error("Would reboot. Terminating.");
 	    else {
-		kill_old_erlang();
+		kill_old_erlang(reason);
 		/* High prio combined with system() works badly indeed... */
 		SetPriorityClass(GetCurrentProcess(), NORMAL_PRIORITY_CLASS);
 		win_system(command);
@@ -685,7 +697,7 @@ do_terminate(int erlin_fd, int reason) {
 	    }
 	    free_env_val(command);
 	} else {
-	    kill_old_erlang();
+	    kill_old_erlang(reason);
 	    /* High prio combined with system() works badly indeed... */
 	    SetPriorityClass(GetCurrentProcess(), NORMAL_PRIORITY_CLASS);
 	    win_system(&cmd[0]);
@@ -697,13 +709,13 @@ do_terminate(int erlin_fd, int reason) {
 	    if(!command)
 		print_error("Would reboot. Terminating.");
 	    else {
-		kill_old_erlang();
+		kill_old_erlang(reason);
 		ret = system(command);
 		print_error("Executed \"%s\" -> %d. Terminating.",command, ret);
 	    }
 	    free_env_val(command);
 	} else {
-	    kill_old_erlang();
+	    kill_old_erlang(reason);
 	    ret = system((char*)&cmd[0]);
 	    print_error("Executed \"%s\" -> %d. Terminating.",cmd, ret);
 	}
diff --git a/erts/etc/unix/Makefile b/erts/etc/unix/Makefile
index 83c64d35fd..21a725cb88 100644
--- a/erts/etc/unix/Makefile
+++ b/erts/etc/unix/Makefile
@@ -30,7 +30,8 @@ opt debug lcnt: etc
 etc: etp-commands
 
 etp-commands: etp-commands.in
-	$(gen_verbose)sed 's:@ERL_TOP@:${ERL_TOP}:g' etp-commands.in > etp-commands
+	$(gen_verbose)sed -e 's:@ERL_TOP@:${ERL_TOP}:g' \
+	etp-commands.in > etp-commands
 
 .PHONY: docs
 docs:
diff --git a/erts/etc/unix/cerl.src b/erts/etc/unix/cerl.src
index 2e034513b0..59de9bdec8 100644
--- a/erts/etc/unix/cerl.src
+++ b/erts/etc/unix/cerl.src
@@ -224,7 +224,13 @@ while [ $# -gt 0 ]; do
 	    shift
 	    cargs="$cargs -rr"
 	    run_rr=yes
-	    skip_erlexec=yes
+            case "$1" in
+                "replay"|"ps")
+                    ;;
+                *)
+	            skip_erlexec=yes
+                    ;;
+            esac
 	    ;;
 	*)
 	    break
@@ -286,28 +292,60 @@ if [ "x$GDB" = "x" ]; then
 		valgrind_log="$log_file_prefix$VALGRIND_LOG_DIR/$VALGRIND_LOGFILE_PREFIX$VALGRIND_LOGFILE_INFIX$EMU_NAME.log"
 	    fi
 	fi
-	if [ "x$VALGRIND_MISC_FLAGS" = "x" ]; then
-	    valgrind_misc_flags=
-	else
-	    valgrind_misc_flags="$VALGRIND_MISC_FLAGS"
+	# Add default flags
+	vgflags=$VALGRIND_MISC_FLAGS
+	if [ "x${vgflags#*--show-possibly-lost}" = "x$vgflags" ]; then
+	    vgflags="$vgflags --show-possibly-lost=no"
+	fi
+	if [ "x${vgflags#*--child-silent-after-fork}" = "x$vgflags" ]; then
+	    vgflags="$vgflags --child-silent-after-fork=yes"
+	fi
+	if [ "x${vgflags#*--suppressions}" = "x$vgflags" ]; then
+	    if [ "x$ERL_TOP" != "x" ]; then
+		vgflags="$vgflags --suppressions=$ERL_TOP/erts/emulator/valgrind/suppress.standard"
+	    else
+		echo "No valgrind suppression file found in \$VALGRIND_MISC_FLAGS and \$ERL_TOP not set."
+	    fi
 	fi
 	if which taskset > /dev/null && test -e /proc/cpuinfo; then
 	    # We only let valgrind utilize one core with "taskset 1" as it can be very slow
 	    # on multiple cores (especially with async threads). Valgrind only run one pthread
 	    # at a time anyway so there is no point letting it utilize more than one core.
 	    # Use $sched_arg to force all schedulers online to emulate multicore.
-	    taskset1="taskset 1"
 	    ncpu=`cat /proc/cpuinfo | grep -w processor | wc -l`
+            # Choose a random core in order to not collide with any other valgrind
+            # run on the same machine.
+            taskset1=$((1 << (`shuf -i 1-$ncpu -n 1` - 1) ))
+	    taskset1="taskset $taskset1"
 	    sched_arg="-S$ncpu:$ncpu"
 	else
 	    taskset1=
 	    sched_arg=
 	fi
 
-	exec $taskset1 valgrind $valgrind_xml $valgrind_log $valgrind_misc_flags $BINDIR/$EMU_NAME $sched_arg $emu_xargs "$@"
+	exec $taskset1 valgrind $valgrind_xml $valgrind_log $vgflags $BINDIR/$EMU_NAME $sched_arg $emu_xargs "$@"
 
     elif [ $run_rr = yes ]; then
-	exec rr record --ignore-nested $BINDIR/$EMU_NAME $emu_xargs "$@"
+        if [ $1 = replay ]; then
+            shift
+            cmdfile="/tmp/.cerlgdb.$$"
+            echo "set \$etp_beam_executable = \"$BINDIR/$EMU_NAME\"" > $cmdfile
+            if [ "$1" = "-p" ]; then
+                echo 'set $etp_rr_run_until_beam = 1' >> $cmdfile
+            fi
+            cat $ROOTDIR/erts/etc/unix/etp-commands >> $cmdfile
+            exec rr replay -x $cmdfile $*
+        elif [ $1 = ps ]; then
+            shift
+            rr ps $* | head -1
+            ChildSetup=`rr ps $* | grep 'erl_child_setup' | awk '{ print $2 }'`
+            for CS in $ChildSetup; do
+                rr ps $* | grep -E "^$CS"
+            done
+            exit 0
+        else
+	    exec rr record --ignore-nested $BINDIR/$EMU_NAME $emu_xargs "$@"
+        fi
     else
 	exec $EXEC $xargs ${1+"$@"}
     fi
diff --git a/erts/etc/unix/etp-commands.in b/erts/etc/unix/etp-commands.in
index b12a205ba7..20809d61e8 100644
--- a/erts/etc/unix/etp-commands.in
+++ b/erts/etc/unix/etp-commands.in
@@ -37,7 +37,7 @@ document etp-help
 % - GDB command toolbox for analyzing core dumps from the
 % Erlang emulator (BEAM).
 % 
-% Should work for 32-bit erts-5.2/R9B, ...
+% Should work for 32-bit and 64-bit unix gdb
 % 
 % The commands are prefixed with:
 %   etp:  Acronym for erts-term-print
@@ -55,7 +55,8 @@ document etp-help
 % Special commands for not really terms:
 %   etp-mfa, etp-cp, etp-disasm,
 %   etp-msgq, etpf-msgq, 
-%   etp-stacktrace, etp-stackdump, etpf-stackdump, etp-dictdump
+%   etp-stacktrace, etp-stacktrace-emu, etp-stackdump, etp-stackdump-emu,
+%   etpf-stackdump, etp-dictdump
 %   etp-process-info, etp-process-memory-info
 %   etp-port-info, etp-port-state, etp-port-sched-flags
 %   etp-heapdump, etp-offheapdump, etpf-offheapdump,
@@ -132,14 +133,14 @@ define etp-1
   if (($arg0) & 0x3) == 1
     # Cons pointer
     if $etp_flat
-      printf "<etpf-cons %#x>", ($arg0)
+      printf "<etpf-cons %p>", (($arg0)-1)
     else
       etp-list-1 ($arg0) ($arg1)
     end
   else
     if (($arg0) & 0x3) == 2
       if $etp_flat
-        printf "<etpf-boxed %#x>", ($arg0)
+        printf "<etpf-boxed %p>", (($arg0)-2)
       else
         etp-boxed-1 ($arg0) ($arg1)
       end
@@ -149,7 +150,7 @@ define etp-1
       else
         # (($arg0) & 0x3) == 0
         if (($arg0) == etp_the_non_value)
-          printf "<the non-value>"
+          printf "<the-non-value>"
         else
           etp-cp-1 ($arg0)
         end
@@ -187,7 +188,7 @@ define etp-list-1
 # Reentrant
 #
   if (($arg0) & 0x3) != 0x1
-    printf "#NotCons<%#x>", ($arg0)
+    printf "#NotCons<%p>", ($arg0)
   else
     # Cons pointer
     if $etp_chart
@@ -210,7 +211,7 @@ define etp-list-printable-1
 # Returns: $etp_list_printable
 #
   if (($arg0) & 0x3) != 0x1
-    printf "#NotCons<%#x>", ($arg0)
+    printf "#NotCons<%p>", ($arg0)
   else
     # Loop to check if it is a printable string
     set $etp_list_p = ($arg0)
@@ -272,7 +273,7 @@ define etp-list-2
 # Reentrant
 #
   if (($arg0) & 0x3) != 0x1
-    printf "#NotCons<%#x>", ($arg0)
+    printf "#NotCons<%p>", ($arg0)
   else
     # Cons pointer
     if ($arg1) >= $etp_max_depth
@@ -307,7 +308,7 @@ define etpf-cons
 # Reentrant capable
 #
   if ((Eterm)($arg0) & 0x3) != 0x1
-    printf "#NotCons<%#x>", ($arg0)
+    printf "#NotCons<%p>", ($arg0)
   else
     # Cons pointer
     set $etp_flat = 1
@@ -336,13 +337,13 @@ define etp-boxed-1
 # Reentrant
 #
   if (($arg0) & 0x3) != 0x2
-    printf "#NotBoxed<%#x>", ($arg0)
+    printf "#NotBoxed<%p>", ($arg0)
   else
     if (((Eterm*)(($arg0) & ~0x3))[0] & 0x3) != 0x0
       if $etp_chart
         etp-chart-entry-1 (($arg0)&~0x3) ($arg1) 1
       end
-      printf "#BoxedError<%#x>", ($arg0)
+      printf "#BoxedError<%p>", ($arg0)
     else
       if $etp_chart
         etp-chart-entry-1 (($arg0)&~0x3) ($arg1) \
@@ -390,10 +391,10 @@ define etp-boxed-immediate-1
 # Non-reentrant
 #
   if (($arg0) & 0x3) != 0x2
-    printf "#NotBoxed<%#x>", ($arg0)
+    printf "#NotBoxed<%p>", ($arg0)
   else
     if (((Eterm*)(($arg0) & ~0x3))[0] & 0x3) != 0x0
-      printf "#BoxedError<%#x>", ($arg0)
+      printf "#BoxedError<%p>", ($arg0)
     else
       set $etp_boxed_immediate_p = (Eterm*)(($arg0) & ~0x3)
       set $etp_boxed_immediate_h = ($etp_boxed_immediate_p[0] >> 2) & 0xF
@@ -438,12 +439,12 @@ define etp-boxed-immediate-1
                   while $etp_boxed_immediate_arity > 0
                     set $etp_boxed_immediate_p++
                     if $etp_boxed_immediate_arity > 1
-                      printf "%#x,", *$etp_boxed_immediate_p
+                      printf "%p,", *$etp_boxed_immediate_p
                     else
-                      printf "%#x", *$etp_boxed_immediate_p
+                      printf "%p", *$etp_boxed_immediate_p
         	      if ($etp_boxed_immediate_h == 0xA)
                         set $etp_boxed_immediate_p++
-		    	printf ":%#x", *$etp_boxed_immediate_p
+			printf ":%p", *$etp_boxed_immediate_p
 		      end
 		      printf ">"
                     end
@@ -558,7 +559,7 @@ define etp-immediate-1
 # Reentrant capable
 #
   if (($arg0) & 0x3) != 0x3
-    printf "#NotImmediate<%#x>", ($arg0)
+    printf "#NotImmediate<%p>", ($arg0)
   else
     if (($arg0) & 0xF) == 0x3 
       etp-pid-1 ($arg0)
@@ -580,7 +581,7 @@ define etp-immediate-1
               if (($arg0) == $etp_nil)
                 printf "[]"
               else
-                printf "#UnknownImmediate<%#x>", ($arg0)
+                printf "#UnknownImmediate<%p>", ($arg0)
               end
             end
           end
@@ -598,7 +599,7 @@ define etp-atom-1
 # Non-reentrant
 #
   if ((Eterm)($arg0) & 0x3f) != 0xb
-    printf "#NotAtom<%#x>", ($arg0)
+    printf "#NotAtom<%p>", ($arg0)
   else
     set $etp_atom_1_ap = (Atom*)erts_atom_table.seg_table[(Eterm)($arg0)>>16][((Eterm)($arg0)>>6)&0x3FF]
     set $etp_atom_1_i = ($etp_atom_1_ap)->len
@@ -652,7 +653,7 @@ define etp-char-1
 # Non-reentrant
 #
   if (($arg0) < 0) || (0377 < ($arg0))
-    printf "#NotChar<%#x>", ($arg0)
+    printf "#NotChar<%p>", ($arg0)
   else
     if ($arg0) == ($arg1)
       printf "\\%c", ($arg0)
@@ -787,7 +788,7 @@ define etp-pid-1
     # Internal pid
     printf "<0.%u.%u>", $etp_pid_data & 0x7fff, ($etp_pid_data >> 15) & 0x1fff
   else
-    printf "#NotPid<%#x>", ($arg0)
+    printf "#NotPid<%p>", ($arg0)
   end
 end
 
@@ -797,11 +798,11 @@ define etp-extpid-1
 # Non-reentrant
 #
   if ((Eterm)($arg0) & 0x3) != 0x2
-    printf "#NotBoxed<%#x>", (Eterm)($arg0)
+    printf "#NotBoxed<%p>", (Eterm)($arg0)
   else
     set $etp_extpid_1_p = (ExternalThing*)((Eterm)($arg0) & ~0x3)
     if ($etp_extpid_1_p->header & 0x3f) != 0x30
-      printf "#NotExternalPid<%#x>", $etp_extpid_1_p->header
+      printf "#NotExternalPid<%p>", $etp_extpid_1_p->header
     else
       ## External pid
       set $etp_extpid_1_number = $etp_extpid_1_p->data.ui[0]&0x7fff
@@ -812,7 +813,7 @@ define etp-extpid-1
       set $etp_extpid_1_node = $etp_extpid_1_np->sysname
       if ($etp_extpid_1_node & 0x3f) != 0xb
         # Should be an atom
-        printf "#ExternalPidError<%#x>", ($arg0)
+        printf "#ExternalPidError<%p>", ($arg0)
       else
         if $etp_extpid_1_dep == erts_this_dist_entry
           printf "<0:"
@@ -847,7 +848,7 @@ define etp-port-1
     # Internal port
     printf "#Port<0.%u>", $etp_port_data
   else
-    printf "#NotPort<%#x>", ($arg0)
+    printf "#NotPort<%p>", ($arg0)
   end
 end
 
@@ -857,11 +858,11 @@ define etp-extport-1
 # Non-reentrant
 #
   if ((Eterm)($arg0) & 0x3) != 0x2
-    printf "#NotBoxed<%#x>", (Eterm)($arg0)
+    printf "#NotBoxed<%p>", (Eterm)($arg0)
   else
     set $etp_extport_1_p = (ExternalThing*)((Eterm)($arg0) & ~0x3)
     if ($etp_extport_1_p->header & 0x3F) != 0x34
-      printf "#NotExternalPort<%#x>", $etp_extport_1->header
+      printf "#NotExternalPort<%p>", $etp_extport_1->header
     else
       ## External port
       set $etp_extport_1_number = $etp_extport_1_p->data.ui[0]&0x3ffff
@@ -871,7 +872,7 @@ define etp-extport-1
       set $etp_extport_1_node = $etp_extport_1_np->sysname
       if ($etp_extport_1_node & 0x3f) != 0xb
         # Should be an atom
-        printf "#ExternalPortError<%#x>", ($arg0)
+        printf "#ExternalPortError<%p>", ($arg0)
       else
         if $etp_extport_1_dep == erts_this_dist_entry
           printf "#Port<0:"
@@ -893,15 +894,15 @@ define etp-bignum-1
 # Non-reentrant
 #
   if ((Eterm)($arg0) & 0x3) != 0x2
-    printf "#NotBoxed<%#x>", (Eterm)($arg0)
+    printf "#NotBoxed<%p>", (Eterm)($arg0)
   else
     set $etp_bignum_1_p = (Eterm*)((Eterm)($arg0) & ~0x3)
     if ($etp_bignum_1_p[0] & 0x3b) != 0x08
-      printf "#NotBignum<%#x>", $etp_bignum_1_p[0]
+      printf "#NotBignum<%p>", $etp_bignum_1_p[0]
     else
       set $etp_bignum_1_i = ($etp_bignum_1_p[0] >> 6)
       if $etp_bignum_1_i < 1
-        printf "#BignumError<%#x>", (Eterm)($arg0)
+        printf "#BignumError<%p>", (Eterm)($arg0)
       else
         if $etp_bignum_1_p[0] & 0x04
           printf "-"
@@ -932,11 +933,11 @@ define etp-float-1
 # Non-reentrant
 #
   if ((Eterm)($arg0) & 0x3) != 0x2
-    printf "#NotBoxed<%#x>", (Eterm)($arg0)
+    printf "#NotBoxed<%p>", (Eterm)($arg0)
   else
     set $etp_float_1_p = (Eterm*)((Eterm)($arg0) & ~0x3)
     if ($etp_float_1_p[0] & 0x3f) != 0x18
-      printf "#NotFloat<%#x>", $etp_float_1_p[0]
+      printf "#NotFloat<%p>", $etp_float_1_p[0]
     else
       printf "%f", *(double*)($etp_float_1_p+1)
     end
@@ -951,14 +952,14 @@ define etp-ref-1
 # Non-reentrant
 #
   if ((Eterm)($arg0) & 0x3) != 0x2
-    printf "#NotBoxed<%#x>", (Eterm)($arg0)
+    printf "#NotBoxed<%p>", (Eterm)($arg0)
   else
     set $etp_ref_1_p = (ErtsORefThing *)((Eterm)($arg0) & ~0x3)
     if ($etp_ref_1_p->header & 0x3b) != 0x10
-      printf "#NotRef<%#x>", $etp_ref_1_p->header
+      printf "#NotRef<%p>", $etp_ref_1_p->header
     else
       if $etp_ref_1_p->header != etp_ref_header && $etp_ref_1_p->header != etp_magic_ref_header
-        printf "#InternalRefError<%#x>", ($arg0)
+        printf "#InternalRefError<%p>", ($arg0)
       else
 	set $etp_magic_ref = 0
 	set $etp_ref_1_i = 3
@@ -998,11 +999,11 @@ define etp-extref-1
 # Non-reentrant
 #
   if ((Eterm)($arg0) & 0x3) != 0x2
-    printf "#NotBoxed<%#x>", (Eterm)($arg0)
+    printf "#NotBoxed<%p>", (Eterm)($arg0)
   else
     set $etp_extref_1_p = (ExternalThing*)((Eterm)($arg0) & ~0x3)
     if ($etp_extref_1_p->header & 0x3F) != 0x38
-      printf "#NotExternalRef<%#x>", $etp_extref_1->header
+      printf "#NotExternalRef<%p>", $etp_extref_1->header
     else
       ## External ref
       set $etp_extref_1_nump = (Uint32 *) 0
@@ -1041,7 +1042,7 @@ define etp-extref-1
         end
       end
       if $etp_extref_1_error
-        printf "#ExternalRefError<%#x>", ($arg0)
+        printf "#ExternalRefError<%p>", ($arg0)
       else
         set $etp_extref_1_i--
         while $etp_extref_1_i >= 0
@@ -1166,7 +1167,7 @@ define etp-cp-1
         if *(Eterm*)($etp_cp) == beam_return_to_trace[0]
 	  printf "#Cp<return to trace>"
 	else
-          printf "#Cp<%#x>", $etp_cp
+          printf "#Cp<%p>", $etp_cp
 	end
       end
     end
@@ -1241,7 +1242,7 @@ define etp-sig-int
     if $etp_sig_tag != etp_the_non_value
       etp-1 $etp_sig_tag 0
     else
-      print "!ENCODED-DIST-MSG"
+      printf "!ENCODED-DIST-MSG"
     end
     if ($arg0)->m[1] != $etp_nil
       printf " @token= "
@@ -1251,7 +1252,7 @@ define etp-sig-int
     etp-1 ($arg0)->m[2] 0
   else
     if ($etp_sig_tag & 0x3f) != 0x30
-      print "!INVALID-SIGNAL"
+      printf "!INVALID-SIGNAL"
     else
       set $etp_sig_op = (($etp_sig_tag >> 6) & 0xff)
       set $etp_sig_type = (($etp_sig_tag >> 14) & 0xff)
@@ -1452,28 +1453,74 @@ end
 define etp-stack-preamble
   set $etp_stack_p = ($arg0)->stop
   set $etp_stack_end = ($arg0)->hend
+  if ($arg0)->state.counter & 0x8000
+    printf "%%%%%% WARNING: The process is currently running, so c_p->stop will not be correct\r\n"
+    printf "%%%%%%          Consider using %s-emu instead\r\n", $arg1
+  end
   printf "%% Stacktrace (%u)\n", $etp_stack_end-$etp_stack_p
-  etp-1 ((Eterm)($arg0)->i) 0
-  printf "  (I)\n"
+  if ($arg0)->i != 0
+    printf "I: "
+    etp ((Eterm)($arg0)->i)
+  end
   if ($arg0)->cp != 0
-    etp-1 ((Eterm)($arg0)->cp) 0
-    printf "  (cp)\n"
+    printf "cp:"
+    etp ((Eterm)($arg0)->cp)
+  end
+end
+
+define etp-stack-preamble-emu
+  set $etp_stack_p = E
+  set $etp_stack_end = ($arg0)->hend
+  printf "%% Stacktrace (%u)\n", $etp_stack_end-$etp_stack_p
+  printf "I: "
+  etp ((BeamInstr)I)
+  if ($arg0)->cp != 0
+    printf "cp: "
+    etp ((Eterm)($arg0)->cp)
+  end
+end
+
+define etp-stacktrace-1
+  set $etp_stack_stop = (Eterm*)($arg0)
+  set $etp_stack_send = (Eterm*)($arg1)
+  set $etp_stack_cnt = 0
+  while $etp_stack_stop < $etp_stack_send
+    if ($etp_stack_stop[0] & 0x3) == 0x0
+      # Continuation pointer
+      printf "%d: ", $etp_stack_cnt
+      etp $etp_stack_stop[0]
+    end
+    set $etp_stack_stop++
+    set $etp_stack_cnt++
   end
 end
 
+define etp-stacktrace-emu
+# Args: Process*
+#
+# Non-reentrant
+#
+  etp-stack-preamble-emu ($arg0)
+  etp-stacktrace-1 $etp_stack_p $etp_stack_end
+end
+
+document etp-stacktrace-emu
+%---------------------------------------------------------------------------
+% etp-stacktrace-emu Process*
+% 
+% Take an Process* and print a stactrace for the process.
+% This macro assumes that the current frame is the process_main frame
+% and that E is not optimized out.
+%---------------------------------------------------------------------------
+end
+
 define etp-stacktrace
 # Args: Process*
 #
 # Non-reentrant
 #
-  etp-stack-preamble ($arg0)
-  while $etp_stack_p < $etp_stack_end
-    if ($etp_stack_p[0] & 0x3) == 0x0
-      # Continuation pointer
-      etp $etp_stack_p[0]
-    end
-    set $etp_stack_p++
-  end
+  etp-stack-preamble ($arg0) "etp-stacktrace"
+  etp-stacktrace-1 $etp_stack_p $etp_stack_end
 end
 
 document etp-stacktrace
@@ -1486,16 +1533,48 @@ document etp-stacktrace
 %---------------------------------------------------------------------------
 end
 
+define etp-stackdump-1
+  # Args: Eterm *stop, Eterm *hend
+  #
+  # Non-reentrant
+  #
+  set $etp_stackdump_stop = (Eterm*)($arg0)
+  set $etp_stackdump_send = (Eterm*)($arg1)
+  set $etp_stackdump_cnt = 0
+  while $etp_stackdump_stop < $etp_stackdump_send
+    printf "%d: ", $etp_stackdump_cnt
+    etp $etp_stackdump_stop[0]
+    set $etp_stackdump_stop++
+    set $etp_stackdump_cnt++
+  end
+end
+
+define etp-stackdump-emu
+# Args: Process*
+#
+# Non-reentrant
+#
+  etp-stack-preamble-emu ($arg0)
+  etp-stackdump-1 $etp_stack_p $etp_stack_end
+end
+
+document etp-stacktrace-emu
+%---------------------------------------------------------------------------
+% etp-stacktrace-emu Process*
+% 
+% Take an Process* and print a stactdump for the process.
+% This macro assumes that the current frame is the process_main frame
+% and that E is not optimized out.
+%---------------------------------------------------------------------------
+end
+
 define etp-stackdump
 # Args: Process*
 #
 # Non-reentrant
 #
-  etp-stack-preamble ($arg0)
-  while $etp_stack_p < $etp_stack_end
-    etp $etp_stack_p[0]
-    set $etp_stack_p++
-  end
+  etp-stack-preamble ($arg0) "etp-stackdump"
+  etp-stackdump-1 $etp_stack_p $etp_stack_end
 end
 
 document etp-stackdump
@@ -1741,7 +1820,7 @@ define etp-term-dump-pid
     # Internal pid
     printf "| <0.%04u.%03u> ", $etp_pid_data & 0x7fff, ($etp_pid_data >> 15) & 0x1fff
   else
-    printf "| #NotPid<%#x> ", ($arg0)
+    printf "| #NotPid<%p> ", ($arg0)
   end
 end
 
@@ -1789,7 +1868,7 @@ define etp-pix2proc
 # Args: Eterm
 #
    set $proc = (Process *) *((UWord *) &erts_proc.r.o.tab[((int) $arg0)])
-   printf "(Process *) %p\n", $proc
+   printf "(Process*)%p\n", $proc
 end
 
 define etp-pid2proc-1
@@ -1803,7 +1882,7 @@ define etp-pid2proc
 # Args: Eterm
 #
    etp-pid2proc-1 $arg0
-   printf "(Process *) %p\n", $proc
+   printf "(Process*)%p\n", $proc
 end
 
 define etp-proc-state-int
@@ -2083,12 +2162,12 @@ define etp-process-info-int
   printf "\n  Flags: "
   etp-proc-flags $etp_proc
   if $proxy_process != 0
-    printf "  Pointer: (Process *) %p\n", $etp_proc
+    printf "  Pointer: (Process*)%p\n", $etp_proc
     printf "  *** PROXY process struct *** refer to: \n"
     etp-pid2proc-1 $etp_proc->common.id
     etp-process-info $proc
   else
-  if (*(((Uint32 *) &($etp_proc->state))) & 0x4) == 0
+  if (*(((Uint32 *) &($etp_proc->state))) & 0x800) == 0
     if ($etp_proc->common.u.alive.reg)
       printf "  Registered name: "
       etp-1 $etp_proc->common.u.alive.reg->name
@@ -2096,7 +2175,7 @@ define etp-process-info-int
     end
   end
   printf "  Current function: "
-  if ($etp_proc->current)
+  if ($etp_proc->current && !($etp_proc->state.counter & 0x800))
     etp-1 $etp_proc->current->module
     printf ":"
     etp-1 $etp_proc->current->function
@@ -2133,7 +2212,7 @@ define etp-process-info-int
   end
   printf "  Parent: "
   etp-1 ((Eterm)($etp_proc->parent))
-  printf "\n  Pointer: (Process *) %p\n", $etp_proc
+  printf "\n  Pointer: (Process*)%p\n", $etp_proc
   end
   if ($arg1)
     etp-sigqs $etp_proc
@@ -2156,6 +2235,43 @@ document etp-process-info
 %---------------------------------------------------------------------------
 end
 
+define etp-processes-free-runq-int
+  set $runq_prio = 0
+  while $runq_prio < 3
+    set $runq_proc = ($arg0)->procs.prio[$runq_prio].first
+    while $runq_proc != 0
+      if $runq_proc->state.counter & 0x400
+        printf "---\n"
+        printf "  Pix: FREE -> run_queue %p\n", ($arg0)
+        etp-process-info-int $runq_proc ($arg1)
+      end
+      set $runq_proc = $runq_proc->next
+    end
+    set $runq_prio++
+  end
+end
+
+define etp-processes-free-de-int
+  set $de_ix = 0
+  set $de = ($arg0)
+  while $de
+    set $susp = $de->suspended
+    set $susp_curr = $susp
+    set $first_loop = 1
+    while $susp_curr != 0 && (($susp_curr != $susp) || $first_loop)
+      if ($susp_curr->u.pid & 0x3) == 0
+        printf "---\n"
+        printf "  Pix: FREE "
+        etp $de->sysname
+        etp-process-info-int $susp_curr->u.pid ($arg2)
+      end
+      set $first_loop = 0
+      set $susp_curr = $susp_curr->next
+    end
+    set $de = $de->next
+  end
+end
+
 define etp-processes-int
   if (!erts_initialized)
     printf "No processes, since system isn't initialized!\n"
@@ -2176,11 +2292,36 @@ define etp-processes-int
         set $proc_cnt--
       end
       if $proc_ix == $proc_printile
-        printf "--- %d%% (%d / %d) searched\n", $proc_printile / $proc_decentile * 10, $proc_ix, $proc_max_ix
+        printf "--- %d%% (%d / %d) searched, looking for %d more\n", $proc_printile / $proc_decentile * 10, $proc_ix, $proc_max_ix, $proc_cnt
         set $proc_printile += $proc_decentile
       end
       set $proc_ix++
     end
+
+    ## We should also check for any FREE processes that are running
+    ## They can be found in esdp->current_process, dep->suspendees and
+    ## runq. Running FREE processes are processes that either are yielding
+    ## when exiting or running on a dirty scheduler while having exited.
+    set $sched_ix = 0
+    while $sched_ix < erts_no_schedulers
+      set $sched_data = &erts_aligned_scheduler_data[$sched_ix].esd
+      if $sched_data->current_process != 0
+        if $sched_data->current_process.state.counter & 0x400
+          printf "---\n"
+          printf "  Pix: FREE -> scheduler %d\n", $sched_ix+1
+          etp-process-info-int $sched_data->current_process ($arg0)
+        end
+      end
+      etp-processes-free-runq-int $sched_data->run_queue ($arg0)
+      set $sched_ix++
+    end
+    etp-processes-free-runq-int &erts_aligned_run_queues[erts_no_run_queues].runq ($arg0)
+    etp-processes-free-runq-int &erts_aligned_run_queues[erts_no_run_queues+1].runq ($arg0)
+    etp-processes-free-de-int erts_hidden_dist_entries erts_no_of_hidden_dist_entries ($arg0)
+    etp-processes-free-de-int erts_visible_dist_entries erts_no_of_visible_dist_entries ($arg0)
+    etp-processes-free-de-int erts_pending_dist_entries erts_no_of_pending_dist_entries ($arg0)
+    etp-processes-free-de-int erts_not_connected_dist_entries erts_no_of_not_connected_dist_entries ($arg0)
+    etp-processes-free-de-int erts_this_dist_entry 1 ($arg0)
     printf "---\n",
   end
 end
@@ -2237,9 +2378,9 @@ define etp-process-memory-info
   end
   printf "  "
   etp-1 $etp_pmem_proc->common.id
-  printf ": (Process *) %p ", $etp_pmem_proc
+  printf ": (Process*)%p ", $etp_pmem_proc
   if $proxy_process != 0
-    printf "(Process *) %p ", $etp_pmem_proc
+    printf "(Process*)%p ", $etp_pmem_proc
     printf "  *** PROXY process struct *** refer to next: \n"
     etp-pid2proc-1 $etp_pmem_proc->common.id
     printf " -"
@@ -2313,7 +2454,7 @@ define etp-pix2port
 # Args: Eterm
 #
    set $port = (Port *) *((UWord *) &erts_port.r.o.tab[((int) $arg0)])
-   printf "(Port *) %p\n", $port
+   printf "(Port*)%p\n", $port
 end
 
 define etp-id2port-1
@@ -2327,7 +2468,7 @@ define etp-id2port
 # Args: Eterm
 #
    etp-id2port-1 $arg0
-   printf "(Port *) %p\n", $port
+   printf "(Port*)%p\n", $port
 end
 
 define etp-port-sched-flags-int
@@ -2501,7 +2642,7 @@ define etp-port-info
   printf "  Connected: "
   set $connected = *(((Eterm *) &(((Port *) $etp_pinfo_port)->connected)))
   etp-1 $connected
-  printf "\n  Pointer: (Port *) %p\n", $etp_pinfo_port
+  printf "\n  Pointer: (Port*)%p\n", $etp_pinfo_port
 end
 
 document etp-port-info
@@ -2851,7 +2992,7 @@ define etp-scheduler-info-internal
   printf " Sleep Info Flags:"
   set $ssi_flags = *((Uint32 *) &$sched_data->ssi->flags)
   etp-ssi-flags $ssi_flags
-  printf " Pointer: (ErtsSchedulerData *) %p\n", $sched_data
+  printf " Pointer: (ErtsSchedulerData*)%p\n", $sched_data
 end
 
 define etp-run-queue-info-internal
@@ -2884,7 +3025,7 @@ define etp-run-queue-info-internal
   end
   set $rq_flags = *((Uint32 *) &($runq->flags))
   etp-rq-flags-int $rq_flags
-  printf "  Pointer: (ErtsRunQueue *) %p\n", $runq
+  printf "  Pointer: (ErtsRunQueue*)%p\n", $runq
 end
 
 define etp-fds
@@ -2895,12 +3036,21 @@ define etp-fds
   end
 end
 
+document etp-fds
+%---------------------------------------------------------------------------
+% etp-fds
+% 
+% Print the state of the fds currently in check_io. Only works in running systems.
+%---------------------------------------------------------------------------
+end
+
 define etp-disasm-1
-  set $code_ptr = ((BeamInstr*)$arg0)
-  set $addr = *$code_ptr
+  set $code_ptr = ((BeamInstr*)($arg0))
+  set $addr32 = (BeamInstr)(Uint32)*$code_ptr
+  set $addr64 = (BeamInstr)(Uint64)*$code_ptr
   set $i = 0
-  while $i < (sizeof(opc) / sizeof(OpEntry))
-    if $addr == beam_ops[$i]
+  while $i < num_instructions
+    if $addr32 == beam_ops[$i] || $addr64 == beam_ops[$i]
       printf "%s %d", opc[$i].name, opc[$i].sz
       set $next_i = $code_ptr + opc[$i].sz
       set $i += 4999
@@ -2910,6 +3060,11 @@ define etp-disasm-1
 end
 
 define etp-disasm
+  if $argc == 1
+    set $code_end = $arg0
+  else
+    set $code_end = $arg1
+  end
   etp-cp-func-info-1 $arg0
   if $etp_cp_p == 0
     printf "invalid argument"
@@ -2918,7 +3073,7 @@ define etp-disasm
     printf ": "
     etp-disasm-1 $arg0
     printf "\r\n"
-    while $next_i < ((BeamInstr*)$arg1)
+    while $next_i < ((BeamInstr*)$code_end)
       set $prev_i = $next_i
       etp-cp-func-info-1 $next_i
       etp-mfa-1 $etp_cp_p $cp_cp_p_offset
@@ -2934,6 +3089,16 @@ define etp-disasm
   end
 end
 
+document etp-disasm
+%---------------------------------------------------------------------------
+% etp-fds BeamInstr* (BeamInstr*)
+% 
+% Disassemble the instructions inbetween arg0 and arg1,
+% if no second argument is given only the current
+% instruction is printed.
+%---------------------------------------------------------------------------
+end
+
 ############################################################################
 #
 # Timer Wheel
@@ -2961,7 +3126,7 @@ define etp-timer-wheel
         printf "\n"
         while 1
            printf "- Timeout pos: %ld\n", $tmr->timeout_pos
-	   printf "  Pointer: (ErtsTWheelTimer *) %p\n", $tmr
+	   printf "  Pointer: (ErtsTWheelTimer*)%p\n", $tmr
            set $tmr = $tmr->next
            if ($tmr == $tiw->w[$ix])
              loop_break
@@ -2991,7 +3156,7 @@ define etp-timer-wheel
         printf "\n"
         while 1
            printf "- Timeout pos: %ld\n", $tmr->timeout_pos
-	   printf "  Pointer: (ErtsTWheelTimer *) %p\n", $tmr
+	   printf "  Pointer: (ErtsTWheelTimer*)%p\n", $tmr
            set $tmr = $tmr->next
            if ($tmr == $tiw->w[$ix])
              loop_break
@@ -3260,7 +3425,7 @@ define etp-offheapdump
       set $etp_offheapdump_p = $etp_offheapdump_p->next
       set $etp_offheapdump_i++
     else
-      printf "#TaggedPtr<%#x>", $etp_offheapdump_p
+      printf "#TaggedPtr<%p>", $etp_offheapdump_p
       set $etp_offheapdump_p = 0
     end
   end
@@ -3299,12 +3464,12 @@ define etp-search-heaps
 #
 # Non-reentrant
 #
-  printf "%% Search all (<%u) process heaps for ", erts_max_processes
+  printf "%% Search all (<%u) process heaps for ", erts_proc.r.o.max
   set $etp_flat = 1
   etp-1 ($arg0) 0
   set $etp_flat = 0
   printf ":...\n"
-  etp-search-heaps-1 ((Eterm*)((Eterm)($arg0)&~3))
+  etp-search-heaps-1 ((Eterm*)((Eterm)($arg0)&~(Eterm)3))
 end
 
 define etp-search-heaps-1
@@ -3312,8 +3477,8 @@ define etp-search-heaps-1
 #
 # Non-reentrant
 #
-  set $etp_search_heaps_q = erts_max_processes / 10
-  set $etp_search_heaps_r = erts_max_processes % 10
+  set $etp_search_heaps_q = erts_proc.r.o.max / 10
+  set $etp_search_heaps_r = erts_proc.r.o.max % 10
   set $etp_search_heaps_t = 10
   set $etp_search_heaps_m = $etp_search_heaps_q
   if $etp_search_heaps_r > 0
@@ -3323,7 +3488,7 @@ define etp-search-heaps-1
   set $etp_search_heaps_i = 0
   set $etp_search_heaps_found = 0
   while $etp_search_heaps_i < erts_proc.r.o.max
-    set $proc = (Process *) *((UWord *) &erts_proc.r.o.tab[$proc_ix])
+    set $proc = (Process *) *((UWord *) &erts_proc.r.o.tab[$etp_search_heaps_i])
     if $proc
       if ($proc->heap <= ($arg0)) && \
          (($arg0) < $proc->hend)
@@ -3340,7 +3505,7 @@ define etp-search-heaps-1
       while $etp_search_heaps_p && ($etp_search_heaps_cnt < $etp_max_depth)
         set $etp_search_heaps_cnt++
         if (&($etp_search_heaps_p->mem) <= ($arg0)) && \
-           (($arg0) < &($etp_search_heaps_p->mem)+$etp_search_heaps_p->size)
+           (($arg0) < &($etp_search_heaps_p->mem)+$etp_search_heaps_p->used_size)
           printf "process_tab[%d]->mbuf(%d)+%d\n", \
                  $etp_search_heaps_i, $etp_search_heaps_cnt, \
                  ($arg0)-&($etp_search_heaps_p->mem)
@@ -3636,8 +3801,8 @@ define etp-overlapped-heaps
 # Non-reentrant
 #
   printf "%% Dumping heap addresses to \"etp-commands.bin\"\n"
-  set $etp_overlapped_heaps_q = erts_max_processes / 10
-  set $etp_overlapped_heaps_r = erts_max_processes % 10
+  set $etp_overlapped_heaps_q = erts_proc.r.o.max / 10
+  set $etp_overlapped_heaps_r = erts_proc.r.o.max % 10
   set $etp_overlapped_heaps_t = 10
   set $etp_overlapped_heaps_m = $etp_overlapped_heaps_q
   if $etp_overlapped_heaps_r > 0
@@ -3663,7 +3828,7 @@ define etp-overlapped-heaps
   append binary value etp-commands.bin 'p'
   append binary value etp-commands.bin 's'
   append binary value etp-commands.bin '\0'
-  while $etp_overlapped_heaps_i < erts_max_processes
+  while $etp_overlapped_heaps_i < erts_proc.r.o.max
     if process_tab[$etp_overlapped_heaps_i]
       append binary value etp-commands.bin \
         (Eterm)$etp_overlapped_heaps_i
@@ -3804,7 +3969,7 @@ define etp-chart-entry-1
   append binary value etp-commands.bin (Eterm)(($arg2)*sizeof(Eterm))
   append binary value etp-commands.bin (Eterm)$etp_chart_id
   append binary value etp-commands.bin (Eterm)($arg1)
-#   printf "<dumped %#x %lu %lu %lu>", ($arg0)&~0x3, \
+#   printf "<dumped %p %lu %lu %lu>", ($arg0)&~0x3, \
 #     (Eterm)(($arg2)*sizeof(Eterm)), (Eterm)$etp_chart_id, (Eterm)($arg1)
 end
 
@@ -3828,22 +3993,79 @@ end
 # ETS table debug
 #
 
+define etp-ets-tab-status-int
+# Args:
+#
+# Non-reentrant
+  if ($arg0 & 0x1)
+    printf "priv"
+  end
+  if ($arg0 & 0x2)
+    printf "prot"
+  end
+  if ($arg0 & 0x4)
+    printf "pub"
+  end
+  if ($arg0 & 0x8)
+    printf "|del"
+  end
+  if ($arg0 & 0x10)
+    printf "|set"
+  end
+  if ($arg0 & 0x20)
+    printf "|bag"
+  end
+  if ($arg0 & 0x40)
+    printf "|dbag"
+  end
+  if ($arg0 & 0x80)
+    printf "|oset"
+  end
+  if ($arg0 & 0x100)
+    printf "|caoset"
+  end
+  if ($arg0 & 0x200)
+    printf "|flocked"
+  end
+  if ($arg0 & 0x400)
+    printf "|fread"
+  end
+  if ($arg0 & 0x800)
+    printf "|named"
+  end
+  if ($arg0 & 0x1000)
+    printf "|busy"
+  end
+end
+
 define etp-ets-tables
 # Args:
 #
 # Non-reentrant
-  printf "%% Dumping < %lu ETS tables\n", (unsigned long)db_max_tabs
-  while $etp_ets_tables_i < db_max_tabs
-    if (meta_main_tab[$etp_ets_tables_i].u.next_free & 3) == 0
-      printf "%% %d:", $etp_ets_tables_i
-      etp-1 ((Eterm)(meta_main_tab[$etp_ets_tables_i].u.tb->common.id)) 0
+  set $sched_ix = 0
+  while $sched_ix < erts_no_schedulers
+    set $ets_tabs = &erts_aligned_scheduler_data[$sched_ix].esd.ets_tables
+    set $no_ets_tabs = *(unsigned long *)&($ets_tabs->count)
+    printf "\n%% %lu ETS tables created on scheduler %lu...\n\n", $no_ets_tabs, (unsigned long)$sched_ix+1
+    set $ets_tab = $ets_tabs->clist
+    set $first_ets_tab = $ets_tab
+    while $ets_tab
+      set $refn = &((ErtsMagicBinary *)$ets_tab->common->btid)->refn
+      printf "%% "
+      etp-1 $ets_tab->common.the_name 0
+      printf " #Ref<0.%u.%u.%u> ", (unsigned)$refn[2], (unsigned)$refn[1], (unsigned)$refn[0]
+      etp-1 $ets_tab->common.owner 0
       printf " "
-      etp-1 ((Eterm)(meta_main_tab[$etp_ets_tables_i].u.tb->common.owner)) 0
-      printf "\n"
+      etp-ets-tab-status-int $ets_tab->common.status
+      printf " (DbTable*)%p\n", $ets_tab
+      if $ets_tab->common.all.next == $first_ets_tab
+	set $ets_tab = (DbTable *) 0
+      else
+	set $ets_tab = $ets_tab->common.all.next
+      end
     end
-    set $etp_ets_tables_i++
+    set $sched_ix++
   end
-  set $etp_ets_tables_i = 0
 end
 
 document etp-ets-tables
@@ -4060,14 +4282,6 @@ define etp-block-size-1
       set $etp_blk_sz = ($arg0)->bhdr & ~7
   else
       # Allocated block
-      if !$etp_MBC_ABLK_SZ_MASK
-        if etp_arch_bits == 64
-          set $etp_MBC_ABLK_OFFSET_SHIFT = (64 - 24)
-        else
-          set $etp_MBC_ABLK_OFFSET_SHIFT = (32 - 9)
-        end
-        set $etp_MBC_ABLK_SZ_MASK = ((UWord)1 << $etp_MBC_ABLK_OFFSET_SHIFT) - 1 - 7
-      end
       set $etp_blk_sz = ($arg0)->bhdr & $etp_MBC_ABLK_SZ_MASK
   end
 end
@@ -4082,14 +4296,7 @@ define etp-block2mbc-1
       set $etp_mbc = ($arg0)->u.carrier
   else
       # Allocated block
-      if !$etp_MBC_ABLK_OFFSET_SHIFT
-        if etp_arch_bits == 64
-          set $etp_MBC_ABLK_OFFSET_SHIFT = (64 - 24)
-        else
-          set $etp_MBC_ABLK_OFFSET_SHIFT = (32 - 9)
-        end
-      end
-      set $etp_mbc = (Carrier_t*) ((((UWord)($arg0) >> 18) - (($arg0)->bhdr >> $etp_MBC_ABLK_OFFSET_SHIFT)) << 18)
+      set $etp_mbc = (Carrier_t*) ((((UWord)($arg0) >> 18) - ((($arg0)->bhdr & $etp_MBC_ABLK_OFFSET_MASK) >> $etp_MBC_ABLK_OFFSET_SHIFT)) << 18)
   end
 end
 
@@ -4133,7 +4340,7 @@ document etp-smp-atomic
 %---------------------------------------------------------------------------
 end
 
-define etp-carrier-blocks
+define etp-carrier-blocks-1
   set $etp_crr = (Carrier_t*) $arg0
   etp-smp-atomic $etp_crr->allctr $etp_alc
   set $etp_alc = (Allctr_t*)($etp_alc & ~7)
@@ -4145,12 +4352,6 @@ define etp-carrier-blocks
   set $etp_fblk_cnt = 0
   set $etp_aborted = 0
 
-  if $argc == 2
-    set $etp_be_silent = $arg1
-  else
-    set $etp_be_silent = 0
-  end
-
   while 1
     if !$etp_be_silent
       etp-block $etp_blk
@@ -4173,6 +4374,12 @@ define etp-carrier-blocks
           printf "ERROR: Missing PREV_FREE_BLK_HDR_FLG (2) in block at %#lx\n", $etp_blk
 	  set $etp_error_cnt = $etp_error_cnt + 1
         end
+      else
+	# Prev is ALLOCATED
+        if ($etp_blk->bhdr & 2)
+          printf "ERROR: Invalid PREV_FREE_BLK_HDR_FLG (2) set in block at %#lx\n", $etp_blk
+	  set $etp_error_cnt = $etp_error_cnt + 1
+        end
       end
     end
     if $etp_blk->bhdr & 1
@@ -4210,13 +4417,31 @@ define etp-carrier-blocks
   end
 end
 
-document etp-carrier-blocks
+define etp-carrier-print
+  set $etp_be_silent = 0
+  etp-carrier-blocks-1 $arg0
+end
+
+document etp-carrier-print
 %---------------------------------------------------------------------------
-% Check and (maybe) print all memory blocks in carrier
-% Args: (Carrier_t*) [1=be_silent]
+% Print all memory blocks in carrier
+% Args: (Carrier_t*)
 %---------------------------------------------------------------------------
 end
 
+define etp-carrier-check
+  set $etp_be_silent = 1
+  etp-carrier-blocks-1 $arg0
+end
+
+document etp-carrier-check
+%---------------------------------------------------------------------------
+% Check all memory blocks in carrier
+% Args: (Carrier_t*)
+%---------------------------------------------------------------------------
+end
+
+
 define etp-address-to-beam-opcode
   set $etp_i = 0
   set $etp_min_diff = ((UWord)1 << (sizeof(UWord)*8 - 1))
@@ -4326,6 +4551,20 @@ document etp-show
 %---------------------------------------------------------------------------
 end
 
+define etp-rr-run-until-beam
+  source @ERL_TOP@/erts/etc/unix/etp-rr-run-until-beam.py
+end
+
+document etp-rr-run-until-beam
+%---------------------------------------------------------------------------
+% etp-rr-run-until-beam
+%
+% Use this gdb macro to make cerl -rr replay -p PID walk until
+% the correct execute has been made. You may have to change the
+% file that is used to debug with.
+%---------------------------------------------------------------------------
+end
+
 ############################################################################
 # Init
 #
@@ -4334,9 +4573,14 @@ define etp-init
   set $etp_arch64 = (sizeof(void *) == 8)
   if $etp_arch64
     set $etp_nil = 0xfffffffffffffffb
+    set $etp_MBC_ABLK_OFFSET_BITS = 23
   else
     set $etp_nil = 0xfffffffb
+    set $etp_MBC_ABLK_OFFSET_BITS = 8
   end
+  set $etp_MBC_ABLK_OFFSET_SHIFT = (sizeof(UWord)*8 - 1 - $etp_MBC_ABLK_OFFSET_BITS)
+  set $etp_MBC_ABLK_OFFSET_MASK = ((((UWord)1 << $etp_MBC_ABLK_OFFSET_BITS) - 1) << $etp_MBC_ABLK_OFFSET_SHIFT)
+  set $etp_MBC_ABLK_SZ_MASK = ((UWord)1 << $etp_MBC_ABLK_OFFSET_SHIFT) - 1 - 7
   set $etp_flat = 0
   set $etp_chart_id = 0
   set $etp_chart = 0
@@ -4363,7 +4607,13 @@ define hook-run
   set $_exitsignal = -1
 end
 
+handle SIGPIPE nostop
+
 etp-init
 help etp-init
-etp-show
-etp-system-info
+if $etp_rr_run_until_beam
+  help etp-rr-run-until-beam
+else
+  etp-show
+  etp-system-info
+end
diff --git a/erts/etc/unix/etp-rr-run-until-beam.py b/erts/etc/unix/etp-rr-run-until-beam.py
new file mode 100644
index 0000000000..078998b910
--- /dev/null
+++ b/erts/etc/unix/etp-rr-run-until-beam.py
@@ -0,0 +1,45 @@
+#
+# %CopyrightBegin%
+#
+# Copyright Ericsson AB 2013-2016. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# %CopyrightEnd%
+#
+
+has_exited = False
+
+def stop_handler (event):
+  global has_exited
+  if isinstance(event, gdb.SignalEvent):
+    print("exit code: %s" % (event.stop_signal))
+    has_exited = True
+
+gdb.events.stop.connect (stop_handler)
+
+gdb.execute('continue')
+
+while not has_exited:
+  r = gdb.execute('when', to_string=True)
+  m = re.match("[^0-9]*([0-9]+)", r)
+  if m:
+    event = int(m.group(1));
+    gdb.execute('start ' + str(event + 1));
+    gdb.execute('continue')
+
+gdb.events.stop.disconnect (stop_handler)
+
+gdb.execute('file ' + str(gdb.parse_and_eval("$etp_beam_executable")))
+gdb.execute('break main')
+gdb.execute('reverse-continue')
diff --git a/erts/etc/unix/gcov-gen-html b/erts/etc/unix/gcov-gen-html
new file mode 100755
index 0000000000..3fd9f1ca49
--- /dev/null
+++ b/erts/etc/unix/gcov-gen-html
@@ -0,0 +1,62 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+@ARGV == 2 or die "Usage: gcov-gen-html \$ERL_TOP <output directory>\n";
+
+my $srcdir = shift @ARGV;
+my $outdir = shift @ARGV;
+
+my $verbose = 1;
+my $flavor = "smp";
+
+# setup filenames and paths, observe geninfos --base-directory
+# it needs a correct path just after the $geninfo
+
+my $lcov_path = ""; #/usr/local/bin/";
+
+my $geninfo      = $lcov_path . "geninfo --no-checksum --base-directory";
+my $genhtml      = $lcov_path . "genhtml";
+
+# src paths
+
+my $emu_src_path  = "$srcdir/erts/emulator";
+my $elib_src_path = "$srcdir/erts/lib_src";
+my $pcre_src_path = "$emu_src_path";
+my $zlib_src_path = "$emu_src_path";
+
+# obj paths
+
+my $emu_obj_path  = <$emu_src_path/obj/*-linux-*/gcov/$flavor>;
+my $elib_obj_path = <$elib_src_path/obj/*-linux-*/gcov>;
+my $pcre_obj_path = <$emu_src_path/pcre/obj/*-linux-*/gcov>;
+my $zlib_obj_path = <$emu_src_path/zlib/obj/*-linux-*/gcov>;
+
+# info files
+
+my $emu_info  = "$srcdir/emulator-cover.info";
+my $elib_info = "$srcdir/elib-cover.info";
+my $pcre_info = "$srcdir/pcre-cover.info";
+
+my $infofiles = "$emu_info $elib_info $pcre_info";
+
+run("$geninfo $emu_src_path  -o $emu_info  $emu_obj_path");
+run("$geninfo $elib_src_path -o $elib_info $elib_obj_path");
+run("$geninfo $pcre_src_path -o $pcre_info $pcre_obj_path");
+
+if (<$zlib_obj_path/*.o>) {
+    my $zlib_info = "$srcdir/zlib-cover.info";
+    $infofiles .= " $zlib_info";
+    run("$geninfo $zlib_src_path -o $zlib_info $zlib_obj_path");
+}
+
+run("$genhtml -o $outdir $infofiles");
+
+
+
+sub run {
+    my $cmd = shift;
+    print STDERR "\nrun($cmd)\n" if $verbose > 0;
+    system("$cmd 2>&1") == 0 or die "\nCan't run \"$cmd\": $?";
+}
diff --git a/erts/etc/unix/to_erl.c b/erts/etc/unix/to_erl.c
index afff8f7e54..1448980f77 100644
--- a/erts/etc/unix/to_erl.c
+++ b/erts/etc/unix/to_erl.c
@@ -245,7 +245,6 @@ int main(int argc, char **argv)
     tty_smode.c_iflag =
 	1*BRKINT |/*Signal interrupt on break.*/
 	    1*IGNPAR |/*Ignore characters with parity errors.*/
-		1*ISTRIP |/*Strip character.*/
 		    0;
     
 #if 0
@@ -416,7 +415,7 @@ int main(int argc, char **argv)
 
 	if (len) {
 #ifdef DEBUG
-	    (void)write(1, buf, len);
+	    write_all(1, buf, len);
 #endif
 	    if (write_all(wfd, buf, len) != len) {
 		fprintf(stderr, "Error in writing to FIFO.\n");
diff --git a/erts/etc/win32/msys_tools/vc/cc.sh b/erts/etc/win32/msys_tools/vc/cc.sh
index 2b0482e876..71af14b9b2 100644
--- a/erts/etc/win32/msys_tools/vc/cc.sh
+++ b/erts/etc/win32/msys_tools/vc/cc.sh
@@ -195,7 +195,6 @@ mkdir $TMPOBJDIR
 
 # Compile
 for x in $SOURCES; do
-    start_time=`date '+%s'` 
     # Compile each source
     if [ $LINKING = false ]; then
 	# We should have an output defined, which is a directory 
@@ -260,16 +259,28 @@ for x in $SOURCES; do
     else
 	tail -n +2 $ERR_FILE >&2
 	if test $DEPENDENCIES = true; then
-	    if test `grep -v $x $MSG_FILE | grep -c '#line'` != "0"; then
-		o=`echo $x | sed 's,.*/,,' | sed 's,\.cp*$,.o,'`
-		echo -n $o':'
-#		cat $MSG_FILE | grep '#line' | grep -v $x | awk -F\" '{printf("%s\n",$2)}' | sort -u | grep -v " " | xargs -n 1 win2msys_path.sh | awk '{printf("\\\n %s ",$0)}' 
-		cat $MSG_FILE | grep '#line' | grep -v $x | awk -F\" '{printf("%s\n",$2)}' | sort -u | grep -v " " | sed 's,^\([A-Za-z]\):[\\/]*,/\1/,;s,\\\\*,/,g'| awk '{printf("\\\n %s ",$0)}' 
-		echo
-		echo 
-		after_sed=`date '+%s'`
-		echo Made dependencies for $x':' `expr $after_sed '-' $start_time` 's' >&2
-	    fi 
+	    perl -e '
+my $file = "'$x'";
+while (<>) {
+      next unless /^#line/;
+      next if /$file/o;
+      (undef,$_) = split(/\"/);
+      next if / /;
+      $all{$_} = 1;
+}
+foreach (sort keys %all) {
+      s@^([A-Za-z]):@/$1@;
+      s@\\\\@/@g;
+      push @f, "\\\n $_ ";
+}
+if (@f) {
+     my $oname = $file;
+     $oname =~ s@.*/@@;
+     $oname =~ s@[.]cp*@.o@;
+     print $oname, ":", @f;
+     print "\n\n";
+     print STDERR "Made dependencies for $file\n";
+}' $MSG_FILE
 	else
 	    cat $MSG_FILE
 	fi
diff --git a/erts/etc/win32/msys_tools/vc/ld.sh b/erts/etc/win32/msys_tools/vc/ld.sh
index 8917251f51..22184faf76 100644
--- a/erts/etc/win32/msys_tools/vc/ld.sh
+++ b/erts/etc/win32/msys_tools/vc/ld.sh
@@ -178,7 +178,10 @@ if [ "$RES" = "0" -a -f "$CMANIFEST" ]; then
     RES=$?
     if [ "$RES" != "0" ]; then
 	REMOVE=`echo "$OUTPUTRES" | sed 's,\\\;[12]$,,g'`
-	CREMOVE=`cygpath $REMOVE`
+	CREMOVE=`win2msys_path.sh $REMOVE`
+        ## If Defender or Search are enabled, they will lock just created files
+        ## and then mt will fail :/
+        echo "If you get this error, make sure Windows Defender AND Windows Search is disabled">>/tmp/link.exe.${p}.1
 	rm -f "$CREMOVE"
     fi
     rm -f "$CMANIFEST"
diff --git a/erts/include/internal/ethr_internal.h b/erts/include/internal/ethr_internal.h
index ac27ff2ed0..17ec84c52b 100644
--- a/erts/include/internal/ethr_internal.h
+++ b/erts/include/internal/ethr_internal.h
@@ -90,7 +90,7 @@ int ethr_init_common__(ethr_init_data *id);
 int ethr_late_init_common__(ethr_late_init_data *lid);
 void ethr_run_exit_handlers__(void);
 void ethr_ts_event_destructor__(void *vtsep);
-void ethr_set_stacklimit__(char *prev_c, size_t stacksize);
+void ethr_set_stacklimit__(char *prev_c, size_t stacksize) ETHR_NOINLINE;
 
 #if defined(ETHR_X86_RUNTIME_CONF__)
 void ethr_x86_cpuid__(int *eax, int *ebx, int *ecx, int *edx);
diff --git a/erts/include/internal/ethread_inline.h b/erts/include/internal/ethread_inline.h
index 8e6bcfc4a8..791d7fa0ff 100644
--- a/erts/include/internal/ethread_inline.h
+++ b/erts/include/internal/ethread_inline.h
@@ -62,12 +62,15 @@
 #  define ETHR_INLINE __inline__
 #  if ETHR_AT_LEAST_GCC_VSN__(3, 1, 1)
 #    define ETHR_FORCE_INLINE __inline__ __attribute__((__always_inline__))
+#    define ETHR_NOINLINE __attribute__((__noinline__))
 #  else
 #    define ETHR_FORCE_INLINE __inline__
+#    define ETHR_NOINLINE
 #  endif
 #elif defined(__WIN32__)
 #  define ETHR_INLINE __forceinline
 #  define ETHR_FORCE_INLINE __forceinline
+#  define ETHR_NOINLINE
 #endif
 
 #endif /* #ifndef ETHREAD_INLINE_H__ */
diff --git a/erts/include/internal/gcc/ethr_dw_atomic.h b/erts/include/internal/gcc/ethr_dw_atomic.h
index 47158b7295..dd116c81ce 100644
--- a/erts/include/internal/gcc/ethr_dw_atomic.h
+++ b/erts/include/internal/gcc/ethr_dw_atomic.h
@@ -78,7 +78,7 @@ typedef volatile ETHR_NATIVE_SU_DW_SINT_T * ethr_native_dw_ptr_t;
  * runtime. We, therefore, need an extra word allocated.
  */
 #define ETHR_DW_NATMC_MEM__(VAR) \
-   (&var->c[(int) ((ethr_uint_t) &(VAR)->c[0]) & ETHR_DW_NATMC_ALIGN_MASK__])
+   (&(VAR)->c[(int) ((ethr_uint_t) &(VAR)->c[0]) & ETHR_DW_NATMC_ALIGN_MASK__])
 typedef union {
     volatile ETHR_NATIVE_SU_DW_SINT_T dw_sint;
     volatile ethr_sint_t sint[3];
diff --git a/erts/include/internal/gcc/ethr_membar.h b/erts/include/internal/gcc/ethr_membar.h
index 07960ce040..5cbda5582d 100644
--- a/erts/include/internal/gcc/ethr_membar.h
+++ b/erts/include/internal/gcc/ethr_membar.h
@@ -96,7 +96,7 @@
  *          issue an aquire memory barrier and an __atomic
  *          builtin memory acess with the __ATOMIC_RELEASE
  *          memory model must at least issue a release memory
- *          barrier. Otherwise the two can not be paired.
+ *          barrier. Otherwise the two cannot be paired.
  *       4. All __atomic builtins accessing memory using the
  *          __ATOMIC_CONSUME builtin can be used for the same
  *          reason __ATOMIC_ACQUIRE can be used. The ethread
diff --git a/erts/include/internal/i386/ethr_dw_atomic.h b/erts/include/internal/i386/ethr_dw_atomic.h
index 91acdb0483..3c47da9758 100644
--- a/erts/include/internal/i386/ethr_dw_atomic.h
+++ b/erts/include/internal/i386/ethr_dw_atomic.h
@@ -73,7 +73,7 @@ typedef volatile ethr_native_sint128_t__ * ethr_native_dw_ptr_t;
  * runtime. We, therefore, need an extra word allocated.
  */
 #define ETHR_DW_NATMC_MEM__(VAR) \
-   (&var->c[(int) ((ethr_uint_t) &(VAR)->c[0]) & ETHR_DW_NATMC_ALIGN_MASK__])
+   (&(VAR)->c[(int) ((ethr_uint_t) &(VAR)->c[0]) & ETHR_DW_NATMC_ALIGN_MASK__])
 typedef union {
 #ifdef ETHR_NATIVE_SU_DW_SINT_T
     volatile ETHR_NATIVE_SU_DW_SINT_T dw_sint;
diff --git a/erts/include/internal/win/ethr_dw_atomic.h b/erts/include/internal/win/ethr_dw_atomic.h
index a6b26ab7bb..f7a1900a82 100644
--- a/erts/include/internal/win/ethr_dw_atomic.h
+++ b/erts/include/internal/win/ethr_dw_atomic.h
@@ -80,7 +80,7 @@ typedef volatile __int64 * ethr_native_dw_ptr_t;
  * runtime. We, therefore, need an extra word allocated.
  */
 #define ETHR_DW_NATMC_MEM__(VAR) \
-   (&var->c[(int) ((ethr_uint_t) &(VAR)->c[0]) & ETHR_DW_NATMC_ALIGN_MASK__])
+   (&(VAR)->c[(int) ((ethr_uint_t) &(VAR)->c[0]) & ETHR_DW_NATMC_ALIGN_MASK__])
 typedef union {
 #ifdef ETHR_NATIVE_SU_DW_SINT_T
     volatile ETHR_NATIVE_SU_DW_SINT_T dw_sint;
diff --git a/erts/lib_src/Makefile.in b/erts/lib_src/Makefile.in
index 8e1f5b58c4..1da11c2d0a 100644
--- a/erts/lib_src/Makefile.in
+++ b/erts/lib_src/Makefile.in
@@ -29,7 +29,6 @@ CC=@CC@
 LD=@LD@
 AR=@AR@
 RANLIB=@RANLIB@
-RM=@RM@
 MKDIR=@MKDIR@
 INSTALL=@INSTALL@
 INSTALL_DIR=@INSTALL_DIR@
@@ -536,9 +535,9 @@ release_docs_spec:
 #
 .PHONY: clean
 clean:
-	$(RM) -rf ../lib/internal/$(TARGET)/*
-	$(RM) -rf ../lib/$(TARGET)/*
-	$(RM) -rf obj/$(TARGET)/*
+	$(RM) -r ../lib/internal/$(TARGET)/*
+	$(RM) -r ../lib/$(TARGET)/*
+	$(RM) -r obj/$(TARGET)/*
 
 #
 # Make dependencies
diff --git a/erts/lib_src/common/erl_printf.c b/erts/lib_src/common/erl_printf.c
index 259ba8c81d..86f5da1c40 100644
--- a/erts/lib_src/common/erl_printf.c
+++ b/erts/lib_src/common/erl_printf.c
@@ -27,6 +27,11 @@
 #include "config.h"
 #endif
 
+#if defined(__sun) || defined(__sun__)
+    /* For flockfile(3c), putc_unlocked(3c), etc */
+    #define __EXTENSIONS__
+#endif
+
 #include <string.h>
 #include "erl_errno.h"
 #ifdef __WIN32__
diff --git a/erts/lib_src/pthread/ethread.c b/erts/lib_src/pthread/ethread.c
index b4b12fcd86..b567ed81b0 100644
--- a/erts/lib_src/pthread/ethread.c
+++ b/erts/lib_src/pthread/ethread.c
@@ -208,9 +208,9 @@ ethr_x86_cpuid__(int *eax, int *ebx, int *ecx, int *edx)
              "popl %%eax\n\t"
              "movl $0x0, %0\n\t"
              "xorl %%ecx, %%eax\n\t"
-             "jz no_cpuid\n\t"
+             "jz 1f\n\t"
 	     "movl $0x1, %0\n\t"
-             "no_cpuid:\n\t"
+             "1:\n\t"
              : "=r"(have_cpuid)
              :
              : "%eax", "%ecx", "cc");
diff --git a/erts/preloaded/ebin/atomics.beam b/erts/preloaded/ebin/atomics.beam
index a5ac24f0b8..c74ce3ce2d 100644
--- a/erts/preloaded/ebin/atomics.beam
+++ b/erts/preloaded/ebin/atomics.beam
diff --git a/erts/preloaded/ebin/counters.beam b/erts/preloaded/ebin/counters.beam
index a1aa34a415..2aec433bcb 100644
--- a/erts/preloaded/ebin/counters.beam
+++ b/erts/preloaded/ebin/counters.beam
diff --git a/erts/preloaded/ebin/erl_init.beam b/erts/preloaded/ebin/erl_init.beam
new file mode 100644
index 0000000000..bc7639781c
--- /dev/null
+++ b/erts/preloaded/ebin/erl_init.beam
diff --git a/erts/preloaded/ebin/erl_prim_loader.beam b/erts/preloaded/ebin/erl_prim_loader.beam
index 37903d24b6..13fdd7908b 100644
--- a/erts/preloaded/ebin/erl_prim_loader.beam
+++ b/erts/preloaded/ebin/erl_prim_loader.beam
diff --git a/erts/preloaded/ebin/erl_tracer.beam b/erts/preloaded/ebin/erl_tracer.beam
index 2509f238bf..16e17b870b 100644
--- a/erts/preloaded/ebin/erl_tracer.beam
+++ b/erts/preloaded/ebin/erl_tracer.beam
diff --git a/erts/preloaded/ebin/erlang.beam b/erts/preloaded/ebin/erlang.beam
index 7563663807..866f9df79f 100644
--- a/erts/preloaded/ebin/erlang.beam
+++ b/erts/preloaded/ebin/erlang.beam
diff --git a/erts/preloaded/ebin/erts_code_purger.beam b/erts/preloaded/ebin/erts_code_purger.beam
index bc697d11d7..d81bc08282 100644
--- a/erts/preloaded/ebin/erts_code_purger.beam
+++ b/erts/preloaded/ebin/erts_code_purger.beam
diff --git a/erts/preloaded/ebin/erts_dirty_process_signal_handler.beam b/erts/preloaded/ebin/erts_dirty_process_signal_handler.beam
index 5b788368af..a8d492dfa5 100644
--- a/erts/preloaded/ebin/erts_dirty_process_signal_handler.beam
+++ b/erts/preloaded/ebin/erts_dirty_process_signal_handler.beam
diff --git a/erts/preloaded/ebin/erts_internal.beam b/erts/preloaded/ebin/erts_internal.beam
index b8415a9833..dd08111aad 100644
--- a/erts/preloaded/ebin/erts_internal.beam
+++ b/erts/preloaded/ebin/erts_internal.beam
diff --git a/erts/preloaded/ebin/erts_literal_area_collector.beam b/erts/preloaded/ebin/erts_literal_area_collector.beam
index e2a8c65f38..0f7dd6efbe 100644
--- a/erts/preloaded/ebin/erts_literal_area_collector.beam
+++ b/erts/preloaded/ebin/erts_literal_area_collector.beam
diff --git a/erts/preloaded/ebin/init.beam b/erts/preloaded/ebin/init.beam
index fee2da33a6..942f29a11c 100644
--- a/erts/preloaded/ebin/init.beam
+++ b/erts/preloaded/ebin/init.beam
diff --git a/erts/preloaded/ebin/otp_ring0.beam b/erts/preloaded/ebin/otp_ring0.beam
index 324e111ad1..0d194896c7 100644
--- a/erts/preloaded/ebin/otp_ring0.beam
+++ b/erts/preloaded/ebin/otp_ring0.beam
diff --git a/erts/preloaded/ebin/persistent_term.beam b/erts/preloaded/ebin/persistent_term.beam
index c73da80a98..7871b64991 100644
--- a/erts/preloaded/ebin/persistent_term.beam
+++ b/erts/preloaded/ebin/persistent_term.beam
diff --git a/erts/preloaded/ebin/prim_buffer.beam b/erts/preloaded/ebin/prim_buffer.beam
index 75e5b7c9cb..90d9596fe6 100644
--- a/erts/preloaded/ebin/prim_buffer.beam
+++ b/erts/preloaded/ebin/prim_buffer.beam
diff --git a/erts/preloaded/ebin/prim_eval.beam b/erts/preloaded/ebin/prim_eval.beam
index ddda4764e1..19935eeee3 100644
--- a/erts/preloaded/ebin/prim_eval.beam
+++ b/erts/preloaded/ebin/prim_eval.beam
diff --git a/erts/preloaded/ebin/prim_file.beam b/erts/preloaded/ebin/prim_file.beam
index 2d1ce7d631..a2c5f2f336 100644
--- a/erts/preloaded/ebin/prim_file.beam
+++ b/erts/preloaded/ebin/prim_file.beam
diff --git a/erts/preloaded/ebin/prim_inet.beam b/erts/preloaded/ebin/prim_inet.beam
index 558968b58a..f77e9e863d 100644
--- a/erts/preloaded/ebin/prim_inet.beam
+++ b/erts/preloaded/ebin/prim_inet.beam
diff --git a/erts/preloaded/ebin/prim_net.beam b/erts/preloaded/ebin/prim_net.beam
new file mode 100644
index 0000000000..9d50b3210f
--- /dev/null
+++ b/erts/preloaded/ebin/prim_net.beam
diff --git a/erts/preloaded/ebin/prim_zip.beam b/erts/preloaded/ebin/prim_zip.beam
index 51721a27a8..bd51c3b271 100644
--- a/erts/preloaded/ebin/prim_zip.beam
+++ b/erts/preloaded/ebin/prim_zip.beam
diff --git a/erts/preloaded/ebin/socket.beam b/erts/preloaded/ebin/socket.beam
new file mode 100644
index 0000000000..73a0bd4f72
--- /dev/null
+++ b/erts/preloaded/ebin/socket.beam
diff --git a/erts/preloaded/ebin/zlib.beam b/erts/preloaded/ebin/zlib.beam
index 4519b540c4..8b7c5fe2ef 100644
--- a/erts/preloaded/ebin/zlib.beam
+++ b/erts/preloaded/ebin/zlib.beam
diff --git a/erts/preloaded/src/Makefile b/erts/preloaded/src/Makefile
index e1bd5bc295..38b85915cc 100644
--- a/erts/preloaded/src/Makefile
+++ b/erts/preloaded/src/Makefile
@@ -1,7 +1,7 @@
 # 
 # %CopyrightBegin%
 # 
-# Copyright Ericsson AB 2008-2018. All Rights Reserved.
+# Copyright Ericsson AB 2008-2019. All Rights Reserved.
 # 
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -33,15 +33,24 @@ STATIC_EBIN=../ebin
 include $(ERL_TOP)/erts/vsn.mk
 include $(ERL_TOP)/lib/kernel/vsn.mk
 
+ifeq ($(USE_ESOCK), yes)
+PRE_LOADED_ERL_ESOCK_MODULES = \
+	socket \
+	prim_net
+else
+PRE_LOADED_ERL_ESOCK_MODULES =
+endif
+
 PRE_LOADED_ERL_MODULES = \
 	erl_prim_loader \
 	init \
 	prim_buffer \
 	prim_file \
 	prim_inet \
+	$(PRE_LOADED_ERL_ESOCK_MODULES) \
 	zlib \
 	prim_zip \
-	otp_ring0 \
+	erl_init \
 	erts_code_purger \
 	erlang \
 	erts_internal \
@@ -71,6 +80,11 @@ STATIC_TARGET_FILES = $(PRE_LOADED_MODULES:%=$(STATIC_EBIN)/%.$(EMULATOR))
 APP_FILE= erts.app
 APP_SRC= $(APP_FILE).src
 APP_TARGET= $(STATIC_EBIN)/$(APP_FILE)
+ifeq ($(USE_ESOCK), yes)
+APP_ESOCK_MODS= prim_net, socket
+else
+APP_ESOCK_MODS=
+endif
 
 
 KERNEL_SRC=$(ERL_TOP)/lib/kernel/src
@@ -79,6 +93,19 @@ STDLIB_INCLUDE=$(ERL_TOP)/lib/stdlib/include
 
 ERL_COMPILE_FLAGS += +debug_info -I$(KERNEL_SRC) -I$(KERNEL_INCLUDE)
 
+DIA_PLT      = erts-preloaded.plt
+DIA_ANALYSIS = $(basename $(DIA_PLT)).dialyzer_analysis
+ifeq ($(DIAW_EH),true)
+DIA_WARNINGS += -Werror_handling
+endif
+ifeq ($(DIAW_US),true)
+DIA_WARNINGS += -Wunderspecs
+endif
+ifeq ($(DIAW_UR),true)
+DIA_WARNINGS += -Wunmatched_returns
+endif
+
+
 debug opt: $(TARGET_FILES) 
 
 clean:
@@ -88,8 +115,7 @@ copy:
 	cp *.beam $(STATIC_EBIN)
 
 $(APP_TARGET): $(APP_SRC) $(ERL_TOP)/erts/vsn.mk
-	$(vsn_verbose)sed -e 's;%VSN%;$(VSN);' $< > $@
-
+	$(vsn_verbose)sed -e 's;%VSN%;$(VSN);' -e 's;%ESOCK_MODS%;$(APP_ESOCK_MODS);' $< > $@
 
 include $(ERL_TOP)/make/otp_release_targets.mk
 
@@ -105,6 +131,31 @@ release_docs_spec:
 list_preloaded:
 	@echo $(PRE_LOADED_MODULES)
 
+dclean:
+	rm -f $(DIA_PLT)
+	rm -f $(DIA_ANALYSIS)
+
+dialyzer_plt: $(DIA_PLT)
+
+$(DIA_PLT): $(ERL_FILES)
+	@echo "Building ($(basename $(DIA_PLT))) plt file"
+	@dialyzer --build_plt \
+                  --output_plt $@ \
+                  -r ../ebin \
+                     ../../../lib/kernel/ebin \
+                     ../../../lib/stdlib/ebin \
+                     ../../../lib/crypto/ebin \
+                     ../../../lib/compiler/ebin \
+                  --output $(DIA_ANALYSIS) \
+                  --verbose
+
+dialyzer: $(DIA_PLT)
+	@echo "Running dialyzer on $(basename $(DIA_PLT))"
+	@dialyzer --plt $< \
+                  ../ebin \
+                  $(DIA_WARNINGS) \
+                  --verbose
+
 #
 # Combine a BEAM assembly script file a stub Erlang file into a BEAM file.
 # See add_abstract_chunk script.
diff --git a/erts/preloaded/src/erl_init.erl b/erts/preloaded/src/erl_init.erl
new file mode 100644
index 0000000000..dadf7dda6f
--- /dev/null
+++ b/erts/preloaded/src/erl_init.erl
@@ -0,0 +1,73 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2000-2019. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(erl_init).
+
+%% Initial process of an Erlang system.
+
+-export([start/2]).
+
+%% This gets the module name given by the +i option (default 'init')
+%% and the list of command line arguments
+
+-spec start(Mod, BootArgs) -> no_return() when
+      Mod :: module(),
+      BootArgs :: [binary()].
+start(Mod, BootArgs) ->
+    %% Load the static nifs
+    zlib:on_load(),
+    erl_tracer:on_load(),
+    prim_buffer:on_load(),
+    prim_file:on_load(),
+    %% socket:on_load(), prim_net:on_load(),
+    conditional_load(socket, [socket, prim_net]),
+    %% Proceed to the specified boot module
+    run(Mod, boot, BootArgs).
+
+run(M, F, A) ->
+    case erlang:function_exported(M, F, 1) of
+	false ->
+	    erlang:display({fatal,error,module,M,"does not export",F,"/1"}),
+	    halt(1);
+	true ->
+            M:F(A)
+    end.
+
+conditional_load(CondMod, Mods2Load) ->
+    Loaded = erlang:loaded(),
+    %% erlang:display({?MODULE, conditional_load, Loaded}),
+    conditional_load(CondMod, Loaded, Mods2Load).
+
+conditional_load(_CondMod, [], _Mods2LOad) ->
+    ok;
+conditional_load(CondMod, [CondMod|_], Mods2Load) ->
+    on_load(Mods2Load);
+conditional_load(CondMod, [_|T], Mods2Load) ->
+    conditional_load(CondMod, T, Mods2Load).
+
+on_load([]) ->
+    ok;
+on_load([Mod|Mods]) ->
+    Mod:on_load(),
+    on_load(Mods).
+
+
+    
+
+
diff --git a/erts/preloaded/src/erl_prim_loader.erl b/erts/preloaded/src/erl_prim_loader.erl
index ae5f86e017..1605c20f2c 100644
--- a/erts/preloaded/src/erl_prim_loader.erl
+++ b/erts/preloaded/src/erl_prim_loader.erl
@@ -297,12 +297,13 @@ check_file_result(Func, Target, {error,Reason}) ->
                         "Target: " ++ TargetStr ++ ". " ++
                         "Function: " ++ atom_to_list(Func) ++ ". " ++ Process
                 end,
-            %% this is equal to calling error_logger:error_report/1 which
-            %% we don't want to do from code_server during system boot
+            %% This is equal to calling logger:error/2 which
+            %% we don't want to do from code_server during system boot.
+            %% We don't want to call logger:timestamp() either.
             logger ! {log,error,#{label=>{?MODULE,file_error},report=>Report},
                       #{pid=>self(),
                         gl=>group_leader(),
-                        time=>erlang:monotonic_time(microsecond),
+                        time=>os:system_time(microsecond),
                         error_logger=>#{tag=>error_report,
                                         type=>std_error}}},
             error
diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index 1ed6b6b284..06f0ee1dc6 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -48,6 +48,8 @@
          dist_ctrl_put_data/2,
          dist_ctrl_get_data/1,
          dist_ctrl_get_data_notification/1,
+         dist_ctrl_get_opt/2,
+         dist_ctrl_set_opt/3,
          dist_get_stat/1]).
 
 -deprecated([get_stacktrace/0,now/0]).
@@ -2295,7 +2297,7 @@ process_flag(_Flag, _Value) ->
                             non_neg_integer()}]} |
       {catchlevel, CatchLevel :: non_neg_integer()} |
       {current_function,
-       {Module :: module(), Function :: atom(), Arity :: arity()}} |
+       {Module :: module(), Function :: atom(), Arity :: arity()} | undefined} |
       {current_location,
        {Module :: module(), Function :: atom(), Arity :: arity(),
         Location :: [{file, Filename :: string()} | % not a stack_item()!
@@ -2526,6 +2528,9 @@ subtract(_,_) ->
                                 OldSchedulersOnline when
       SchedulersOnline :: pos_integer(),
       OldSchedulersOnline :: pos_integer();
+                        (system_logger, Logger) -> PrevLogger when
+      Logger :: logger | undefined | pid(),
+      PrevLogger :: logger | undefined | pid();
                         (trace_control_word, TCW) -> OldTCW when
       TCW :: non_neg_integer(),
       OldTCW :: non_neg_integer();
@@ -2534,7 +2539,7 @@ subtract(_,_) ->
                         %% These are deliberately not documented
 			(internal_cpu_topology, term()) -> term();
                         (sequential_tracer, pid() | port() | {module(), term()} | false) -> pid() | port() | false;
-                        (1,0) -> true.
+                        (reset_seq_trace,true) -> true.
 
 system_flag(_Flag, _Value) ->
     erlang:nif_error(undefined).
@@ -2731,8 +2736,9 @@ tuple_to_list(_Tuple) ->
          (schedulers | schedulers_online) -> pos_integer();
          (smp_support) -> boolean();
          (start_time) -> integer();
-         (system_version) -> string();
          (system_architecture) -> string();
+         (system_logger) -> logger | undefined | pid();
+         (system_version) -> string();
          (threads) -> boolean();
          (thread_pool_size) -> non_neg_integer();
          (time_correction) -> true | false;
@@ -3322,7 +3328,8 @@ dist_ctrl_input_handler(_DHandle, _InputHandler) ->
 dist_ctrl_put_data(_DHandle, _Data) ->
     erlang:nif_error(undefined).
 
--spec erlang:dist_ctrl_get_data(DHandle) -> Data | 'none' when
+-spec erlang:dist_ctrl_get_data(DHandle) -> {Size, Data} | Data | 'none' when
+      Size :: non_neg_integer(),
       DHandle :: dist_handle(),
       Data :: iodata().
 
@@ -3335,11 +3342,26 @@ dist_ctrl_get_data(_DHandle) ->
 dist_ctrl_get_data_notification(_DHandle) ->
     erlang:nif_error(undefined).
 
+-spec erlang:dist_ctrl_set_opt(DHandle, 'get_size', Value) -> OldValue when
+      DHandle :: dist_handle(),
+      Value :: boolean(),
+      OldValue :: boolean().
+
+dist_ctrl_set_opt(_DHandle, _Opt, _Val) ->
+    erlang:nif_error(undefined).
+
+-spec erlang:dist_ctrl_get_opt(DHandle, 'get_size') -> Value when
+      DHandle :: dist_handle(),
+      Value :: boolean().
+
+dist_ctrl_get_opt(_DHandle, _Opt) ->
+    erlang:nif_error(undefined).
+
 -spec erlang:dist_get_stat(DHandle) -> Res when
       DHandle :: dist_handle(),
       InputPackets :: non_neg_integer(),
       OutputPackets :: non_neg_integer(),
-      PendingOutputPackets :: boolean(),
+      PendingOutputPackets :: non_neg_integer(),
       Res :: {'ok', InputPackets, OutputPackets, PendingOutputPackets}.
 
 dist_get_stat(_DHandle) ->
@@ -3395,60 +3417,15 @@ get_cookie() ->
 -spec integer_to_list(Integer, Base) -> string() when
       Integer :: integer(),
       Base :: 2..36.
-integer_to_list(I, 10) ->
-    erlang:integer_to_list(I);
-integer_to_list(I, Base) 
-  when erlang:is_integer(I), erlang:is_integer(Base),
-       Base >= 2, Base =< 1+$Z-$A+10 ->
-    if I < 0 ->
-	    [$-|integer_to_list(-I, Base, [])];
-       true ->
-	    integer_to_list(I, Base, [])
-    end;
-integer_to_list(I, Base) ->
-    erlang:error(badarg, [I, Base]).
-
-integer_to_list(I0, Base, R0) ->
-    D = I0 rem Base,
-    I1 = I0 div Base,
-    R1 = if D >= 10 ->
-		 [D-10+$A|R0];
-	    true ->
-		 [D+$0|R0]
-	 end,
-    if I1 =:= 0 ->
-	    R1;
-       true ->
-	    integer_to_list(I1, Base, R1)
-    end.
+integer_to_list(_I, _Base) ->
+    erlang:nif_error(undefined).
 
 -spec integer_to_binary(Integer, Base) -> binary() when
       Integer :: integer(),
       Base :: 2..36.
-integer_to_binary(I, 10) ->
-    erlang:integer_to_binary(I);
-integer_to_binary(I, Base) 
-  when erlang:is_integer(I), erlang:is_integer(Base),
-       Base >= 2, Base =< 1+$Z-$A+10 ->
-    if I < 0 ->
-	    <<$-,(integer_to_binary(-I, Base, <<>>))/binary>>;
-       true ->
-	    integer_to_binary(I, Base, <<>>)
-    end;
-integer_to_binary(I, Base) ->
-    erlang:error(badarg, [I, Base]).
-
-integer_to_binary(I0, Base, R0) ->
-    D = I0 rem Base,
-    I1 = I0 div Base,
-    R1 = if
-             D >= 10 -> <<(D-10+$A),R0/binary>>;
-             true -> <<(D+$0),R0/binary>>
-         end,
-    if
-        I1 =:= 0 -> R1;
-        true -> integer_to_binary(I1, Base, R1)
-    end.
+integer_to_binary(_I, _Base) ->
+    erlang:nif_error(undefined).
+
 
 -record(cpu, {node = -1,
 	      processor = -1,
@@ -3654,90 +3631,28 @@ memory() ->
 -spec erlang:memory(Type :: memory_type()) -> non_neg_integer();
                    (TypeList :: [memory_type()]) -> [{memory_type(), non_neg_integer()}].
 memory(Type) when erlang:is_atom(Type) ->
-    {AA, ALCU, ChkSup, BadArgZero} = need_mem_info(Type),
-    case get_mem_data(ChkSup, ALCU, AA) of
-	notsup ->
-	    erlang:error(notsup, [Type]);
-	Mem ->
-	    Value = get_memval(Type, Mem),
-	    case {BadArgZero, Value} of
-		{true, 0} -> erlang:error(badarg, [Type]);
-		_ -> Value
-	    end
+    try
+        case aa_mem_data(au_mem_data(?ALL_NEEDED_ALLOCS)) of
+            notsup -> erlang:error(notsup);
+            Mem -> get_memval(Type, Mem)
+        end
+    catch
+        error:badarg -> erlang:error(badarg)
     end;
 memory(Types) when erlang:is_list(Types) ->
-    {AA, ALCU, ChkSup, BadArgZeroList} = need_mem_info_list(Types),
-    case get_mem_data(ChkSup, ALCU, AA) of
-	notsup ->
-	    erlang:error(notsup, [Types]);
-	Mem ->
-	    case memory_result_list(Types, BadArgZeroList, Mem) of
-		badarg -> erlang:error(badarg, [Types]);
-		Result -> Result
-	    end
-    end.
-
-memory_result_list([], [], _Mem) ->
-    [];
-memory_result_list([T|Ts], [BAZ|BAZs], Mem) ->
-    case memory_result_list(Ts, BAZs, Mem) of
-	badarg -> badarg;
-	TVs ->
-	    V = get_memval(T, Mem),
-	    case {BAZ, V} of
-		{true, 0} -> badarg;
-		_ -> [{T, V}| TVs]
-	    end
-    end.
-
-get_mem_data(true, AlcUAllocs, NeedAllocatedAreas) ->
-    case memory_is_supported() of
-	false -> notsup;
-	true -> get_mem_data(false, AlcUAllocs, NeedAllocatedAreas)
-    end;
-get_mem_data(false, AlcUAllocs, NeedAllocatedAreas) ->
-    AlcUMem = case AlcUAllocs of
-		  [] -> #memory{};
-		  _ ->
-		      au_mem_data(AlcUAllocs)
-	      end,
-    case NeedAllocatedAreas of
-	true -> aa_mem_data(AlcUMem);
-	false -> AlcUMem
+    try
+        case aa_mem_data(au_mem_data(?ALL_NEEDED_ALLOCS)) of
+            notsup -> erlang:error(notsup);
+            Mem -> memory_1(Types, Mem)
+        end
+    catch
+        error:badarg -> erlang:error(badarg)
     end.
 
-need_mem_info_list([]) ->
-    {false, [], false, []};
-need_mem_info_list([T|Ts]) ->
-    {MAA, MALCU, MChkSup, MBadArgZero} = need_mem_info_list(Ts),
-    {AA, ALCU, ChkSup, BadArgZero} = need_mem_info(T),
-    {case AA of
-	 true -> true;
-	 _ -> MAA
-     end,
-     ALCU ++ (MALCU -- ALCU),
-     case ChkSup of
-	 true -> true;
-	 _ -> MChkSup
-     end,
-     [BadArgZero|MBadArgZero]}.
-
-need_mem_info(Type) when Type == total;
-			 Type == system ->
-    {true, ?ALL_NEEDED_ALLOCS, false, false};
-need_mem_info(Type) when Type == processes;
-			 Type == processes_used ->
-    {true, [eheap_alloc, fix_alloc], true, false};
-need_mem_info(Type) when Type == atom;
-			 Type == atom_used;
-			 Type == code ->
-    {true, [], true, false};
-need_mem_info(binary) ->
-    {false, [binary_alloc], true, false};
-need_mem_info(ets) ->
-    {true, [ets_alloc], true, false};
-need_mem_info(_) ->
-    {false, [], false, true}.
+memory_1([Type | Types], Mem) ->
+    [{Type, get_memval(Type, Mem)} | memory_1(Types, Mem)];
+memory_1([], _Mem) ->
+    [].
 
 get_memval(total, #memory{total = V}) -> V;
 get_memval(processes, #memory{processes = V}) -> V;
@@ -3748,16 +3663,7 @@ get_memval(atom_used, #memory{atom_used = V}) -> V;
 get_memval(binary, #memory{binary = V}) -> V;
 get_memval(code, #memory{code = V}) -> V;
 get_memval(ets, #memory{ets = V}) -> V;
-get_memval(_, #memory{}) -> 0.
-
-memory_is_supported() ->
-    {_, _, FeatureList, _} = erlang:system_info(allocator),
-    case ((erlang:system_info(alloc_util_allocators) 
-	   -- ?CARRIER_ALLOCS)
-	  -- FeatureList) of
-	[] -> true;
-	_ -> false
-    end.
+get_memval(_, #memory{}) -> erlang:error(badarg).
 
 get_blocks_size([{blocks_size, Sz, _, _} | Rest], Acc) ->
     get_blocks_size(Rest, Acc+Sz);
@@ -3768,16 +3674,6 @@ get_blocks_size([_ | Rest], Acc) ->
 get_blocks_size([], Acc) ->
     Acc.
 
-
-blocks_size([{Carriers, SizeList} | Rest], Acc) when Carriers == mbcs;
-						     Carriers == mbcs_pool;
-						     Carriers == sbcs ->
-    blocks_size(Rest, get_blocks_size(SizeList, Acc));
-blocks_size([_ | Rest], Acc) ->
-    blocks_size(Rest, Acc);
-blocks_size([], Acc) ->
-    Acc.
-
 get_fix_proc([{ProcType, A1, U1}| Rest], {A0, U0}) when ProcType == proc;
 							ProcType == monitor;
 							ProcType == link;
@@ -3802,64 +3698,78 @@ fix_proc([_ | Rest], Acc) ->
 fix_proc([], Acc) ->
     Acc.
 
+au_mem_fix(#memory{ processes = Proc,
+                    processes_used = ProcU,
+                    system = Sys } = Mem, Data) ->
+    case fix_proc(Data, {0, 0}) of
+        {A, U} ->
+            Mem#memory{ processes = Proc+A,
+                        processes_used = ProcU+U,
+                        system = Sys-A };
+        {Mask, A, U} ->
+            Mem#memory{ processes = Mask band (Proc+A),
+                        processes_used = Mask band (ProcU+U),
+                        system = Mask band (Sys-A) }
+    end.
+
+au_mem_acc(#memory{ total = Tot,
+                    processes = Proc,
+                    processes_used = ProcU } = Mem,
+           eheap_alloc, Data) ->
+    Sz = get_blocks_size(Data, 0),
+    Mem#memory{ total = Tot+Sz,
+                processes = Proc+Sz,
+                processes_used = ProcU+Sz};
+au_mem_acc(#memory{ total = Tot,
+                    system = Sys,
+                    ets = Ets } = Mem, ets_alloc, Data) ->
+    Sz = get_blocks_size(Data, 0),
+    Mem#memory{ total = Tot+Sz,
+                system = Sys+Sz,
+                ets = Ets+Sz };
+au_mem_acc(#memory{total = Tot,
+		    system = Sys,
+		    binary = Bin } = Mem,
+	    binary_alloc, Data) ->
+    Sz = get_blocks_size(Data, 0),
+    Mem#memory{ total = Tot+Sz,
+                system = Sys+Sz,
+                binary = Bin+Sz};
+au_mem_acc(#memory{ total = Tot,
+                    system = Sys } = Mem,
+           _Type, Data) ->
+    Sz = get_blocks_size(Data, 0),
+    Mem#memory{ total = Tot+Sz,
+                system = Sys+Sz }.
+
+au_mem_foreign(Mem, [{Type, SizeList} | Rest]) ->
+    au_mem_foreign(au_mem_acc(Mem, Type, SizeList), Rest);
+au_mem_foreign(Mem, []) ->
+    Mem.
+
+au_mem_current(Mem0, Type, [{mbcs_pool, MBCS} | Rest]) ->
+    [Foreign] = [Foreign || {foreign_blocks, Foreign} <- MBCS],
+    SizeList = MBCS -- [Foreign],
+    Mem = au_mem_foreign(Mem0, Foreign),
+    au_mem_current(au_mem_acc(Mem, Type, SizeList), Type, Rest);
+au_mem_current(Mem, Type, [{mbcs, SizeList} | Rest]) ->
+    au_mem_current(au_mem_acc(Mem, Type, SizeList), Type, Rest);
+au_mem_current(Mem, Type, [{sbcs, SizeList} | Rest]) ->
+    au_mem_current(au_mem_acc(Mem, Type, SizeList), Type, Rest);
+au_mem_current(Mem, Type, [_ | Rest]) ->
+    au_mem_current(Mem, Type, Rest);
+au_mem_current(Mem, _Type, []) ->
+    Mem.
+
 au_mem_data(notsup, _) ->
     notsup;
 au_mem_data(_, [{_, false} | _]) ->
     notsup;
-au_mem_data(#memory{total = Tot,
-		    processes = Proc,
-		    processes_used = ProcU} = Mem,
-	    [{eheap_alloc, _, Data} | Rest]) ->
-    Sz = blocks_size(Data, 0),
-    au_mem_data(Mem#memory{total = Tot+Sz,
-			   processes = Proc+Sz,
-			   processes_used = ProcU+Sz},
-		Rest);
-au_mem_data(#memory{total = Tot,
-		    system = Sys,
-		    ets = Ets} = Mem,
-	    [{ets_alloc, _, Data} | Rest]) ->
-    Sz = blocks_size(Data, 0),
-    au_mem_data(Mem#memory{total = Tot+Sz,
-			   system = Sys+Sz,
-			   ets = Ets+Sz},
-		Rest);
-au_mem_data(#memory{total = Tot,
-		    system = Sys,
-		    binary = Bin} = Mem,
-	    [{binary_alloc, _, Data} | Rest]) ->
-    Sz = blocks_size(Data, 0),
-    au_mem_data(Mem#memory{total = Tot+Sz,
-			   system = Sys+Sz,
-			   binary = Bin+Sz},
-		Rest);
-au_mem_data(#memory{total = Tot,
-		    processes = Proc,
-		    processes_used = ProcU,
-		    system = Sys} = Mem,
-	    [{fix_alloc, _, Data} | Rest]) ->
-    Sz = blocks_size(Data, 0),
-    case fix_proc(Data, {0, 0}) of
-	{A, U} ->
-	    au_mem_data(Mem#memory{total = Tot+Sz,
-				   processes = Proc+A,
-				   processes_used = ProcU+U,
-				   system = Sys+Sz-A},
-			Rest);
-	{Mask, A, U} ->
-	    au_mem_data(Mem#memory{total = Tot+Sz,
-				   processes = Mask band (Proc+A),
-				   processes_used = Mask band (ProcU+U),
-				   system = Mask band (Sys+Sz-A)},
-			Rest)
-    end;
-au_mem_data(#memory{total = Tot,
-		    system = Sys} = Mem,
-	    [{_, _, Data} | Rest]) ->
-    Sz = blocks_size(Data, 0),
-    au_mem_data(Mem#memory{total = Tot+Sz,
-			   system = Sys+Sz},
-		Rest);
+au_mem_data(#memory{} = Mem0, [{fix_alloc, _, Data} | Rest]) ->
+    Mem = au_mem_fix(Mem0, Data),
+    au_mem_data(au_mem_current(Mem, fix_alloc, Data), Rest);
+au_mem_data(#memory{} = Mem, [{Type, _, Data} | Rest]) ->
+    au_mem_data(au_mem_current(Mem, Type, Data), Rest);
 au_mem_data(EMD, []) ->
     EMD.
 
diff --git a/erts/preloaded/src/erts.app.src b/erts/preloaded/src/erts.app.src
index ab0b9494b0..132397b478 100644
--- a/erts/preloaded/src/erts.app.src
+++ b/erts/preloaded/src/erts.app.src
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2013-2018. All Rights Reserved.
+%% Copyright Ericsson AB 2013-2019. All Rights Reserved.
 %% 
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -26,7 +26,7 @@
 		erl_prim_loader,
 		erts_internal,
 		init,
-		otp_ring0,
+		erl_init,
 		erts_code_purger,
 		prim_buffer,
 		prim_eval,
@@ -35,7 +35,8 @@
 		prim_zip,
                 atomics,
                 counters,
-		zlib
+		zlib,
+		%ESOCK_MODS%
 	    ]},
 	{registered, []},
 	{applications, []},
diff --git a/erts/preloaded/src/erts_internal.erl b/erts/preloaded/src/erts_internal.erl
index 8f29a569f2..305b524438 100644
--- a/erts/preloaded/src/erts_internal.erl
+++ b/erts/preloaded/src/erts_internal.erl
@@ -97,6 +97,8 @@
 -export([counters_new/1, counters_get/2, counters_add/3,
          counters_put/3, counters_info/1]).
 
+-export([spawn_system_process/3]).
+
 %%
 %% Await result of send to port
 %%
@@ -726,3 +728,10 @@ counters_put(_Ref, _Ix, _Value) ->
 -spec counters_info(reference()) -> #{}.
 counters_info(_Ref) ->
     erlang:nif_error(undef).
+
+-spec spawn_system_process(Mod, Func, Args) -> pid() when
+    Mod :: atom(),
+    Func :: atom(),
+    Args :: list().
+spawn_system_process(_Mod, _Func, _Args) ->
+    erlang:nif_error(undefined).
diff --git a/erts/preloaded/src/init.erl b/erts/preloaded/src/init.erl
index b4b8b3bf9b..5ea67347ec 100644
--- a/erts/preloaded/src/init.erl
+++ b/erts/preloaded/src/init.erl
@@ -200,12 +200,6 @@ boot(BootArgs) ->
     register(init, self()),
     process_flag(trap_exit, true),
 
-    %% Load the static nifs
-    zlib:on_load(),
-    erl_tracer:on_load(),
-    prim_buffer:on_load(),
-    prim_file:on_load(),
-
     {Start0,Flags,Args} = parse_boot_args(BootArgs),
     %% We don't get to profile parsing of BootArgs
     case b2a(get_flag(profile_boot, Flags, false)) of
@@ -483,13 +477,16 @@ do_handle_msg(Msg,State) ->
 	{From, {ensure_loaded, _}} ->
 	    From ! {init, not_allowed};
 	X ->
+            %% This is equal to calling logger:info/3 which we don't
+            %% want to do from the init process, at least not during
+            %% system boot. We don't want to call logger:timestamp()
+            %% either.
 	    case whereis(user) of
 		undefined ->
-		    Time = erlang:monotonic_time(microsecond),
                     catch logger ! {log, info, "init got unexpected: ~p", [X],
                                     #{pid=>self(),
                                       gl=>self(),
-                                      time=>Time,
+                                      time=>os:system_time(microsecond),
                                       error_logger=>#{tag=>info_msg}}};
 		User ->
 		    User ! X,
diff --git a/erts/preloaded/src/persistent_term.erl b/erts/preloaded/src/persistent_term.erl
index 5d0c266127..ee7e49b6cb 100644
--- a/erts/preloaded/src/persistent_term.erl
+++ b/erts/preloaded/src/persistent_term.erl
@@ -19,7 +19,7 @@
 %%
 -module(persistent_term).
 
--export([erase/1,get/0,get/1,info/0,put/2]).
+-export([erase/1,get/0,get/1,get/2,info/0,put/2]).
 
 -type key() :: term().
 -type value() :: term().
@@ -41,6 +41,13 @@ get() ->
 get(_Key) ->
     erlang:nif_error(undef).
 
+-spec get(Key, Default) -> Value when
+      Key :: key(),
+      Default :: value(),
+      Value :: value().
+get(_Key, _Default) ->
+    erlang:nif_error(undef).
+
 -spec info() -> Info when
       Info :: #{'count':=Count,'memory':=Memory},
       Count :: non_neg_integer(),
diff --git a/erts/preloaded/src/prim_eval.S b/erts/preloaded/src/prim_eval.S
index e4b1560517..900fda5d89 100644
--- a/erts/preloaded/src/prim_eval.S
+++ b/erts/preloaded/src/prim_eval.S
@@ -42,6 +42,10 @@
   {label,3}.
     {loop_rec,{f,5},{x,0}}.
     {move,{y,1},{x,1}}.
+    %% Tell the validator that it's safe to pass the message as an argument,
+    %% as the match fun is "known" not to build a term with it, and the
+    %% loop_rec instruction has disabled the GC.
+    {'%', {remove_fragility, {x,0}}}.
     {call_fun,1}.
     {test,is_ne_exact,{f,4},[{x,0},{atom,nomatch}]}.
     remove_message.
diff --git a/erts/preloaded/src/prim_file.erl b/erts/preloaded/src/prim_file.erl
index 5fc22bc582..1aa5d85c64 100644
--- a/erts/preloaded/src/prim_file.erl
+++ b/erts/preloaded/src/prim_file.erl
@@ -46,7 +46,7 @@
 -define(MIN_READLINE_SIZE, 256).
 -define(LARGEFILESIZE, (1 bsl 63)).
 
--export([copy/3]).
+-export([copy/3, start/0]).
 
 -include("file_int.hrl").
 
@@ -85,14 +85,21 @@ is_translatable(_) ->
 
 %% This is a janitor process used to close files whose controlling process has
 %% died. The emulator will be torn down if this is killed.
-delayed_close_loop() ->
+start() ->
+    helper_loop().
+
+helper_loop() ->
     receive
         {close, FRef} when is_reference(FRef) -> delayed_close_nif(FRef);
         _ -> ok
     end,
-    delayed_close_loop().
+    helper_loop().
 
-%%
+on_load() ->
+    %% This is spawned as a system process to prevent init:restart/0 from
+    %% killing it.
+    Pid = erts_internal:spawn_system_process(?MODULE, start, []),
+    ok = erlang:load_nif(atom_to_list(?MODULE), Pid).
 
 %% Returns {error, Reason} | {ok, BytesCopied}
 copy(#file_descriptor{module = ?MODULE} = Source,
@@ -103,14 +110,6 @@ copy(#file_descriptor{module = ?MODULE} = Source,
     %% XXX Should be moved down to the driver for optimization.
     file:copy_opened(Source, Dest, Length).
 
-on_load() ->
-    Pid = spawn(fun() ->
-                    process_flag(trap_exit, true),
-                    delayed_close_loop()
-                end),
-    true = register(erts_prim_file, Pid),
-    ok = erlang:load_nif(atom_to_list(?MODULE), Pid).
-
 open(Name, Modes) ->
     %% The try/catch pattern seen here is used throughout the file to adhere to
     %% the public file interface, which has leaked through for ages because of
@@ -573,12 +572,13 @@ list_dir_convert([RawName | Rest], SkipInvalid, Result) ->
         {error, ignore} ->
             list_dir_convert(Rest, SkipInvalid, Result);
         {error, warning} ->
-            %% this is equal to calling error_logger:warning_msg/2 which
-            %% we don't want to do from code_server during system boot
+            %% This is equal to calling logger:warning/3 which
+            %% we don't want to do from code_server during system boot.
+            %% We don't want to call logger:timestamp() either.
             logger ! {log,warning,"Non-unicode filename ~p ignored\n", [RawName],
                       #{pid=>self(),
                         gl=>group_leader(),
-                        time=>erlang:system_time(microsecond),
+                        time=>os:system_time(microsecond),
                         error_logger=>#{tag=>warning_msg}}},
             list_dir_convert(Rest, SkipInvalid, Result);
         {error, _} ->
diff --git a/erts/preloaded/src/prim_inet.erl b/erts/preloaded/src/prim_inet.erl
index f1d938c9a4..4dab3de006 100644
--- a/erts/preloaded/src/prim_inet.erl
+++ b/erts/preloaded/src/prim_inet.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2000-2018. All Rights Reserved.
+%% Copyright Ericsson AB 2000-2019. All Rights Reserved.
 %% 
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -172,8 +172,18 @@ close(S) when is_port(S) ->
             %% and is a contradiction in itself.
             %% We have hereby done our best...
             %%
-            Tref = erlang:start_timer(T * 1000, self(), close_port),
-            close_pend_loop(S, Tref, undefined);
+            case subscribe(S, [subs_empty_out_q]) of
+                {ok, [{subs_empty_out_q,0}]} ->
+                    close_port(S);
+                {ok, [{subs_empty_out_q,N}]} when N > 0 ->
+                    %% Wait for pending output to be sent
+                    Tref = erlang:start_timer(T * 1000, self(), close_port),
+                    close_pend_loop(S, Tref, N);
+                _ ->
+                    %% Subscribe failed - wait full time
+                    Tref = erlang:start_timer(T * 1000, self(), close_port),
+                    close_pend_loop(S, Tref, undefined)
+            end;
 	_ -> % Regard this as {ok,{false,_}}
             case subscribe(S, [subs_empty_out_q]) of
                 {ok, [{subs_empty_out_q,N}]} when N > 0 ->
@@ -417,7 +427,7 @@ accept_opts(L, S, FamilyOpts) ->
     case
         getopts(
           L,
-          [active, nodelay, keepalive, delay_send, priority]
+          [active, nodelay, keepalive, delay_send, priority, linger]
           ++ FamilyOpts)
     of
 	{ok, Opts} ->
@@ -543,34 +553,49 @@ send(S, Data) ->
 %% "sendto" is for UDP. IP and Port are set by the caller to 0 if the socket
 %% is known to be connected.
 
-sendto(S, Addr, _, Data) when is_port(S), tuple_size(Addr) =:= 2 ->
-    case type_value(set, addr, Addr) of
-	true ->
-	    ?DBG_FORMAT("prim_inet:sendto(~p, ~p, ~p)~n", [S,Addr,Data]),
-	    try
-		erlang:port_command(S, [enc_value(set, addr, Addr),Data])
-	    of
-		true ->
-		    receive
-			{inet_reply,S,Reply} ->
-			    ?DBG_FORMAT(
-			       "prim_inet:sendto() -> ~p~n", [Reply]),
-			    Reply
-		    end
-	    catch
-		error:_ ->
-		    ?DBG_FORMAT(
-		       "prim_inet:sendto() -> {error,einval}~n", []),
-		    {error,einval}
-	    end;
-	false ->
-	    ?DBG_FORMAT(
-	       "prim_inet:sendto() -> {error,einval}~n", []),
-	    {error,einval}
-    end;
-sendto(S, IP, Port, Data) ->
-    sendto(S, {IP, Port}, 0, Data).
-
+sendto(S, {_, _} = Address, AncOpts, Data)
+  when is_port(S), is_list(AncOpts) ->
+    case encode_opt_val(AncOpts) of
+        {ok, AncData} ->
+            AncDataLen = iolist_size(AncData),
+            case
+                type_value(set, addr, Address) andalso
+                type_value(set, uint32, AncDataLen)
+            of
+                true ->
+                    ?DBG_FORMAT("prim_inet:sendto(~p, ~p, ~p, ~p)~n",
+                                [S,Address,AncOpts,Data]),
+                    PortCommandData =
+                        [enc_value(set, addr, Address),
+                         enc_value(set, uint32, AncDataLen), AncData,
+                         Data],
+                    try erlang:port_command(S, PortCommandData) of
+                        true ->
+                            receive
+                                {inet_reply,S,Reply} ->
+                                    ?DBG_FORMAT(
+                                       "prim_inet:sendto() -> ~p~n", [Reply]),
+                                    Reply
+                            end
+                    catch
+                        _:_ ->
+                            ?DBG_FORMAT(
+                               "prim_inet:sendto() -> {error,einval}~n", []),
+                            {error,einval}
+                    end;
+                false ->
+                    ?DBG_FORMAT(
+                       "prim_inet:sendto() -> {error,einval}~n", []),
+                    {error,einval}
+            end;
+        {error,_} ->
+            ?DBG_FORMAT(
+               "prim_inet:sendto() -> {error,einval}~n", []),
+            {error,einval}
+    end;                        
+sendto(S, IP, Port, Data)
+  when is_port(S), is_integer(Port) ->
+    sendto(S, {IP, Port}, [], Data).
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%
@@ -1742,7 +1767,7 @@ type_opt_1(O) when is_atom(O) -> undefined.
 
 %% Get. No supplied value.
 type_value(get, undefined)        -> false; % Undefined type
-%% These two clauses can not happen since they are only used
+%% These two clauses cannot happen since they are only used
 %% in record fields - from record fields they must have a
 %% value though it might be 'undefined', so record fields
 %% calls type_value/3, not type_value/2.
@@ -1908,7 +1933,7 @@ type_value_2(_, _)         -> false.
 
 %% Get. No supplied value.
 %%
-%% These two clauses can not happen since they are only used
+%% These two clauses cannot happen since they are only used
 %% in record fields - from record fields they must have a
 %% value though it might be 'undefined', so record fields
 %% calls enc_value/3, not enc_value/2.
@@ -1983,15 +2008,15 @@ enc_value_2(addr, {File,_}) when is_list(File); is_binary(File) ->
     [?INET_AF_LOCAL,iolist_size(File)|File];
 %%
 enc_value_2(addr, {inet,{any,Port}}) ->
-    [?INET_AF_INET,?int16(Port),0,0,0,0];
+    [?INET_AF_INET,?int16(Port)|ip4_to_bytes({0,0,0,0})];
 enc_value_2(addr, {inet,{loopback,Port}}) ->
-    [?INET_AF_INET,?int16(Port),127,0,0,1];
+    [?INET_AF_INET,?int16(Port)|ip4_to_bytes({127,0,0,1})];
 enc_value_2(addr, {inet,{IP,Port}}) ->
     [?INET_AF_INET,?int16(Port)|ip4_to_bytes(IP)];
 enc_value_2(addr, {inet6,{any,Port}}) ->
-    [?INET_AF_INET6,?int16(Port),0,0,0,0,0,0,0,0];
+    [?INET_AF_INET6,?int16(Port)|ip6_to_bytes({0,0,0,0,0,0,0,0})];
 enc_value_2(addr, {inet6,{loopback,Port}}) ->
-    [?INET_AF_INET6,?int16(Port),0,0,0,0,0,0,0,1];
+    [?INET_AF_INET6,?int16(Port)|ip6_to_bytes({0,0,0,0,0,0,0,1})];
 enc_value_2(addr, {inet6,{IP,Port}}) ->
     [?INET_AF_INET6,?int16(Port)|ip6_to_bytes(IP)];
 enc_value_2(addr, {local,Addr}) ->
@@ -2139,10 +2164,10 @@ enum_name(_, []) -> false.
 %% encode opt/val REVERSED since options are stored in reverse order
 %% i.e. the recent options first (we must process old -> new)
 encode_opt_val(Opts) -> 
-    try 
-	enc_opt_val(Opts, [])
+    try
+	{ok, enc_opt_val(Opts, [])}
     catch
-	Reason -> {error,Reason}
+	throw:Reason -> {error,Reason}
     end.
 
 %% {active, once} and {active, N} are specially optimized because they will
@@ -2161,17 +2186,21 @@ enc_opt_val([binary|Opts], Acc) ->
     enc_opt_val(Opts, Acc, mode, binary);
 enc_opt_val([list|Opts], Acc) ->
     enc_opt_val(Opts, Acc, mode, list);
-enc_opt_val([_|_], _) -> {error,einval};
-enc_opt_val([], Acc)  -> {ok,Acc}.
+enc_opt_val([_|_], _) ->
+    throw(einval);
+enc_opt_val([], Acc) ->
+    Acc.
 
 enc_opt_val(Opts, Acc, Opt, Val) when is_atom(Opt) ->
     Type = type_opt(set, Opt),
     case type_value(set, Type, Val) of
 	true -> 
 	    enc_opt_val(Opts, [enc_opt(Opt),enc_value(set, Type, Val)|Acc]);
-	false -> {error,einval}
+	false ->
+            throw(einval)
     end;
-enc_opt_val(_, _, _, _) -> {error,einval}.
+enc_opt_val(_, _, _, _) ->
+    throw(einval).
 
 
 
@@ -2679,12 +2708,13 @@ get_ip6([X1,X2,X3,X4,X5,X6,X7,X8,X9,X10,X11,X12,X13,X14,X15,X16 | T]) ->
 	?u16(X9,X10),?u16(X11,X12),?u16(X13,X14),?u16(X15,X16)},
       T }.
 
+-define(ERTS_INET_DRV_CONTROL_MAGIC_NUMBER, 16#03f1a300).
 
 %% Control command
 ctl_cmd(Port, Cmd, Args) ->
     ?DBG_FORMAT("prim_inet:ctl_cmd(~p, ~p, ~p)~n", [Port,Cmd,Args]),
     Result =
-	try erlang:port_control(Port, Cmd, Args) of
+	try erlang:port_control(Port, Cmd+?ERTS_INET_DRV_CONTROL_MAGIC_NUMBER, Args) of
 	    [?INET_REP_OK|Reply]  -> {ok,Reply};
 	    [?INET_REP]  -> inet_reply;
 	    [?INET_REP_ERROR|Err] -> {error,list_to_atom(Err)}
diff --git a/erts/preloaded/src/prim_net.erl b/erts/preloaded/src/prim_net.erl
new file mode 100644
index 0000000000..107043d1aa
--- /dev/null
+++ b/erts/preloaded/src/prim_net.erl
@@ -0,0 +1,289 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(prim_net).
+
+-compile(no_native).
+
+%% Administrative and "global" utility functions
+-export([
+	 on_load/0, on_load/1,
+	 info/0,
+         command/1
+        ]).
+
+-export([
+         gethostname/0,
+         getnameinfo/2,
+         getaddrinfo/2,
+
+         if_name2index/1,
+         if_index2name/1,
+         if_names/0
+        ]).
+
+-export_type([
+              address_info/0,
+              name_info/0,
+
+              name_info_flags/0,
+              name_info_flag/0,
+              name_info_flag_ext/0,
+
+              network_interface_name/0,
+              network_interface_index/0
+             ]).
+
+
+-type name_info_flags()         :: [name_info_flag()|name_info_flag_ext()].
+-type name_info_flag()          :: namereqd |
+                                   dgram |
+                                   nofqdn |
+                                   numerichost |
+                                   nomericserv.
+-type name_info_flag_ext()      :: idn |
+                                   idna_allow_unassigned |
+                                   idna_use_std3_ascii_rules.
+-type name_info()               :: #{host    := string(),
+                                     service := string()}.
+-type address_info()            :: #{family   := socket:domain(),
+                                     socktype := socket:type(),
+                                     protocol := socket:protocol(),
+                                     address  := socket:sockaddr()}.
+-type network_interface_name()  :: string().
+-type network_interface_index() :: non_neg_integer().
+
+
+%% ===========================================================================
+%%
+%% Administrative and utility API
+%%
+%% ===========================================================================
+
+-spec on_load() -> ok.
+
+%% Should we require that the Extra arg is a map?
+on_load() ->
+    on_load(#{}).
+
+-spec on_load(Extra) -> ok when
+      Extra :: map().
+
+on_load(Extra) ->
+    ok = erlang:load_nif(atom_to_list(net), Extra).
+
+
+-spec info() -> list().
+
+info() ->
+    nif_info().
+
+
+-spec command(Cmd :: term()) -> term().
+
+command(Cmd) ->
+    nif_command(Cmd).
+
+
+
+%% ===========================================================================
+%%
+%% The proper net API
+%%
+%% ===========================================================================
+
+%% ===========================================================================
+%%
+%% gethostname - Get the name of the current host.
+%%
+%%
+
+-spec gethostname() -> {ok, HostName} | {error, Reason} when
+      HostName :: string(),
+      Reason   :: term().
+
+gethostname() ->
+    nif_gethostname().
+
+
+%% ===========================================================================
+%%
+%% getnameinfo - Address-to-name translation in protocol-independent manner.
+%%
+%%
+
+-spec getnameinfo(SockAddr, Flags) -> {ok, Info} | {error, Reason} when
+      SockAddr :: socket:sockaddr(),
+      Flags    :: name_info_flags() | undefined,
+      Info     :: name_info(),
+      Reason   :: term().
+
+getnameinfo(SockAddr, [] = _Flags) ->
+    getnameinfo(SockAddr, undefined);
+getnameinfo(#{family := Fam, addr := _Addr} = SockAddr, Flags)
+  when ((Fam =:= inet) orelse (Fam =:= inet6)) andalso 
+       (is_list(Flags) orelse (Flags =:= undefined)) ->
+    nif_getnameinfo(socket:ensure_sockaddr(SockAddr), Flags);
+getnameinfo(#{family := Fam, path := _Path} = SockAddr, Flags)
+  when (Fam =:= local) andalso (is_list(Flags) orelse (Flags =:= undefined)) ->
+    nif_getnameinfo(SockAddr, Flags).
+
+
+%% ===========================================================================
+%%
+%% getaddrinfo - Network address and service translation
+%%
+%% There is also a "hint" argument that we "at some point" should implement.
+
+-spec getaddrinfo(Host, undefined) -> {ok, Info} | {error, Reason} when
+      Host    :: string(),
+      Info    :: [address_info()],
+      Reason  :: term()
+                 ; (undefined, Service) -> {ok, Info} | {error, Reason} when
+      Service :: string(),
+      Info    :: [address_info()],
+      Reason  :: term()
+                 ; (Host, Service) -> {ok, Info} | {error, Reason} when
+      Host    :: string(),
+      Service :: string(),
+      Info    :: [address_info()],
+      Reason  :: term().
+
+getaddrinfo(Host, Service)
+  when (is_list(Host) orelse (Host =:= undefined)) andalso
+       (is_list(Service) orelse (Service =:= undefined)) andalso
+       (not ((Service =:= undefined) andalso (Host =:= undefined))) ->
+    nif_getaddrinfo(Host, Service, undefined).
+
+
+
+%% ===========================================================================
+%%
+%% if_name2index - Mappings between network interface names and indexes:
+%%                 name -> idx
+%%
+%%
+
+-spec if_name2index(Name) -> {ok, Idx} | {error, Reason} when
+      Name   :: network_interface_name(),
+      Idx    :: network_interface_index(),
+      Reason :: term().
+
+if_name2index(If) when is_list(If) ->
+    nif_if_name2index(If).
+
+
+
+%% ===========================================================================
+%%
+%% if_index2name - Mappings between network interface index and names:
+%%                 idx -> name
+%%
+%%
+
+-spec if_index2name(Idx) -> {ok, Name} | {error, Reason} when
+      Idx    :: network_interface_index(),
+      Name   :: network_interface_name(),
+      Reason :: term().
+
+if_index2name(Idx) when is_integer(Idx) ->
+    nif_if_index2name(Idx).
+
+
+
+%% ===========================================================================
+%%
+%% if_names - Get network interface names and indexes
+%%
+%%
+
+-spec if_names() -> Names | {error, Reason} when
+      Names  :: [{Idx, If}],
+      Idx    :: network_interface_index(),
+      If     :: network_interface_name(),
+      Reason :: term().
+
+if_names() ->
+    nif_if_names().
+
+
+
+%% ===========================================================================
+%%
+%% Misc utility functions
+%%
+%% ===========================================================================
+
+%% formated_timestamp() ->
+%%     format_timestamp(os:timestamp()).
+
+%% format_timestamp(Now) ->
+%%     N2T = fun(N) -> calendar:now_to_local_time(N) end,
+%%     format_timestamp(Now, N2T, true).
+
+%% format_timestamp({_N1, _N2, N3} = N, N2T, true) ->
+%%     FormatExtra = ".~.2.0w",
+%%     ArgsExtra   = [N3 div 10000],
+%%     format_timestamp(N, N2T, FormatExtra, ArgsExtra);
+%% format_timestamp({_N1, _N2, _N3} = N, N2T, false) ->
+%%     FormatExtra = "",
+%%     ArgsExtra   = [],
+%%     format_timestamp(N, N2T, FormatExtra, ArgsExtra).
+
+%% format_timestamp(N, N2T, FormatExtra, ArgsExtra) ->
+%%     {Date, Time}   = N2T(N),
+%%     {YYYY,MM,DD}   = Date,
+%%     {Hour,Min,Sec} = Time,
+%%     FormatDate =
+%%         io_lib:format("~.4w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w" ++ FormatExtra,
+%%                       [YYYY, MM, DD, Hour, Min, Sec] ++ ArgsExtra),
+%%     lists:flatten(FormatDate).
+
+
+%% ===========================================================================
+%%
+%% The actual NIF-functions.
+%%
+%% ===========================================================================
+
+nif_info() ->
+    erlang:nif_error(undef).
+
+nif_command(_Cmd) ->
+    erlang:nif_error(undef).
+
+nif_gethostname() ->
+    erlang:nif_error(undef).
+
+nif_getnameinfo(_Addr, _Flags) ->
+    erlang:nif_error(undef).
+
+nif_getaddrinfo(_Host, _Service, _Hints) ->
+    erlang:nif_error(undef).
+
+nif_if_name2index(_Name) ->
+    erlang:nif_error(undef).
+
+nif_if_index2name(_Id) ->
+    erlang:nif_error(undef).
+
+nif_if_names() ->
+    erlang:nif_error(undef).
+
diff --git a/erts/preloaded/src/socket.erl b/erts/preloaded/src/socket.erl
new file mode 100644
index 0000000000..07e720c44d
--- /dev/null
+++ b/erts/preloaded/src/socket.erl
@@ -0,0 +1,3989 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2018-2019. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(socket).
+
+-compile(no_native).
+-compile({no_auto_import,[error/1]}).
+
+%% Administrative and "global" utility functions
+-export([
+	 on_load/0, on_load/1,
+
+         ensure_sockaddr/1,
+
+         debug/1,
+         %% command/1,
+	 info/0, info/1,
+         supports/0, supports/1, supports/2, supports/3
+        ]).
+
+-export([
+         open/2, open/3, open/4,
+         bind/2, bind/3,
+         connect/2, connect/3,
+         listen/1, listen/2,
+         accept/1, accept/2,
+
+         send/2, send/3, send/4,
+         sendto/3, sendto/4, sendto/5,
+         sendmsg/2, sendmsg/3, sendmsg/4,
+
+         recv/1, recv/2, recv/3, recv/4,
+         recvfrom/1, recvfrom/2, recvfrom/3, recvfrom/4,
+         recvmsg/1, recvmsg/2, recvmsg/3, recvmsg/5,
+
+         close/1,
+         shutdown/2,
+
+         setopt/4,
+         getopt/3,
+
+         sockname/1,
+         peername/1,
+
+         cancel/2
+        ]).
+
+-export_type([
+              select_tag/0,
+              select_ref/0,
+              select_info/0,
+
+              socket_counters/0,
+              socket_counter/0,
+              socket_info/0,
+
+              %% command/0,
+
+              domain/0,
+              type/0,
+              protocol/0,
+              socket/0,
+
+              port_number/0,
+              ip_address/0,
+              ip4_address/0,
+              ip6_address/0,
+              sockaddr/0,
+              sockaddr_in4/0,
+              sockaddr_in6/0,
+              sockaddr_un/0,
+
+              accept_flags/0,
+              accept_flag/0,
+
+              send_flags/0,
+              send_flag/0,
+
+              recv_flags/0,
+              recv_flag/0,
+
+              shutdown_how/0,
+
+              sockopt_level/0,
+              otp_socket_option/0,
+              socket_option/0,
+              ip_socket_option/0,
+              ipv6_socket_option/0,
+              tcp_socket_option/0,
+              udp_socket_option/0,
+              sctp_socket_option/0,
+              raw_socket_option/0,
+
+              timeval/0,
+              ip_tos/0,
+              ip_mreq/0,
+              ip_mreq_source/0,
+              ip_pmtudisc/0,
+              ip_msfilter_mode/0,
+              ip_msfilter/0,
+              ip_pktinfo/0,
+              ipv6_mreq/0,
+              ipv6_pmtudisc/0,
+              ipv6_pktinfo/0,
+              in6_flow_info/0,
+              in6_scope_id/0,
+              sctp_assoc_id/0,
+              sctp_sndrcvinfo/0,
+              sctp_event_subscribe/0,
+              sctp_assocparams/0,
+              sctp_initmsg/0,
+              sctp_rtoinfo/0,
+
+
+              msghdr_flag/0,
+              msghdr_flags/0,
+              msghdr/0,
+              cmsghdr_level/0,
+              cmsghdr_type/0,
+              %% cmsghdr_data/0,
+              cmsghdr_recv/0, cmsghdr_send/0,
+
+              uint8/0,
+              uint16/0,
+              uint20/0,
+              uint32/0,
+              int32/0
+             ]).
+
+
+%% The command type has the general form: 
+%% #{
+%%   command := atom(),
+%%   data    := term()
+%%  }
+%% But only certain values are actually valid, so the type gets the form:
+-type debug_command() :: #{
+                           command := debug,
+                           data    := boolean()
+                          }.
+%% -type command() :: debug_command().
+
+-type socket_counters() :: [{socket_counter(), non_neg_integer()}].
+-type socket_counter()  :: read_byte | read_fails | read_pkg | read_tries |
+                           read_waits | write_byte | write_fails | write_pkg |
+                           write_tries | write_waits.
+-type socket_info() :: #{counters      := socket_counters(),
+                         num_readers   := non_neg_integer(),
+                         num_writers   := non_neg_integer(),
+                         num_acceptors := non_neg_integer()}.
+
+-type uint8()  :: 0..16#FF.
+-type uint16() :: 0..16#FFFF.
+-type uint20() :: 0..16#FFFFF.
+-type uint32() :: 0..16#FFFFFFFF.
+-type int32()  :: -2147483648..2147483647.
+
+
+%% We support only a subset of all domains.
+-type domain() :: local | inet | inet6.
+
+%% We support only a subset of all types.
+%% RDM - Reliably Delivered Messages
+-type type()   :: stream | dgram | raw | rdm | seqpacket.
+
+%% We support only a subset of all protocols:
+%% Note that the '{raw, integer()}' construct is intended
+%% to be used with type = raw.
+%% Note also that only the "superuser" can create a raw socket.
+-type protocol() :: ip | tcp | udp | sctp | icmp | igmp | {raw, integer()}.
+
+-type port_number() :: 0..65535.
+
+-type ip_address() :: ip4_address() | ip6_address().
+
+-type ip4_address() :: {0..255, 0..255, 0..255, 0..255}.
+
+-type in6_flow_info() :: uint20().
+-type in6_scope_id()  :: uint32().
+
+-type ip6_address() ::
+           {0..65535,
+            0..65535,
+            0..65535,
+            0..65535,
+            0..65535,
+            0..65535,
+            0..65535,
+            0..65535}.
+
+-type timeval() :: #{sec  := integer(),
+                     usec := integer()}.
+
+-type ip_pktinfo() :: #{
+                        ifindex  := non_neg_integer(), % Interface Index
+                        spec_dst := ip4_address(),     % Local Address
+                        addr     := ip4_address()      % Header Destination address
+                       }.
+
+%% If the integer value is used, its up to the caller to ensure its valid!
+-type ip_tos() :: lowdeley |
+                  throughput |
+                  reliability |
+                  mincost |
+                  integer().
+
+%% This type is used when requesting to become member of a multicast
+%% group with a call to setopt. Example: 
+%%
+%%     socket:setopt(Socket, ip, add_membership, #{multiaddr => Addr,
+%%                                                 interface => any}).
+%%
+%% Its also used when removing from a multicast group. Example:
+%%
+%%     socket:setopt(Socket, ip, drop_membership, #{multiaddr => Addr,
+%%                                                  interface => any}).
+%%
+
+-type ip_mreq() :: #{multiaddr := ip4_address(),
+                     interface := any | ip4_address()}.
+%% -type ip_mreqn() :: #{multiaddr := ip4_address(),
+%%                       address   := any | ip4_address(),
+%%                       ifindex   := integer()}.
+
+-type ip_mreq_source() :: #{multiaddr  := ip4_address(),
+                            interface  := ip4_address(),
+                            sourceaddr := ip4_address()}.
+
+-type ip_pmtudisc() :: want | dont | do | probe.
+
+%% multiaddr: Multicast group address
+%% interface: Address of local interface
+%% mode:      Filter mode
+%% slist:     List of source addresses
+-type ip_msfilter_mode() :: include | exclude.
+
+-type ip_msfilter() :: #{multiaddr := ip4_address(),
+                         interface := ip4_address(),
+                         mode      := ip_msfilter_mode(),
+                         slist     := [ip4_address()]}.
+
+-type ipv6_mreq() :: #{multiaddr := ip6_address(),
+                       interface := non_neg_integer()}.
+
+-type ipv6_pmtudisc() :: ip_pmtudisc().
+
+-type ipv6_pktinfo() :: #{
+                          addr    := ip6_address(),
+                          ifindex := integer()
+                         }.
+
+
+-type sctp_assoc_id() :: int32().
+-type sctp_sndrcvinfo() :: #{
+                             stream     := uint16(),
+                             ssn        := uint16(),
+                             flags      := uint16(),
+                             ppid       := uint16(),
+                             context    := uint16(),
+                             timetolive := uint16(),
+                             tsn        := uint16(),
+                             cumtsn     := uint16(),
+                             assoc_id   := sctp_assoc_id()
+                            }.
+
+-type sctp_event_subscribe() :: #{data_in          := boolean(),
+                                  association      := boolean(),
+                                  address          := boolean(),
+                                  send_failure     := boolean(),
+                                  peer_error       := boolean(),
+                                  shutdown         := boolean(),
+                                  partial_delivery := boolean(),
+                                  adaptation_layer := boolean(),
+                                  authentication   := boolean(),
+                                  sender_dry       := boolean()}.
+
+-type sctp_assocparams() :: #{assoc_id       := sctp_assoc_id(),
+                              max_rxt        := uint16(),
+                              num_peer_dests := uint16(),
+                              peer_rwnd      := uint32(),
+                              local_rwnd     := uint32(),
+                              cookie_life    := uint32()}.
+
+-type sctp_initmsg() :: #{num_outstreams := uint16(),
+                          max_instreams  := uint16(),
+                          max_attempts   := uint16(),
+                          max_init_timeo := uint16()
+                         }.
+
+-type sctp_rtoinfo() :: #{assoc_id := sctp_assoc_id(),
+                          initial  := uint32(),
+                          max      := uint32(),
+                          min      := uint32()}.
+
+-type sockaddr_un()  :: #{family := local,
+                          path   := binary() | string()}.
+-type sockaddr_in4() :: #{family := inet,
+                          port   := port_number(),
+			  %% The 'broadcast' here is the "limited broadcast"
+                          addr   := any | broadcast | loopback | ip4_address()}.
+-type sockaddr_in6() :: #{family   := inet6,
+                          port     := port_number(),
+                          addr     := any | loopback | ip6_address(),
+                          flowinfo := in6_flow_info(),
+                          scope_id := in6_scope_id()}.
+-type sockaddr() :: sockaddr_in4() |
+                    sockaddr_in6() |
+                    sockaddr_un().
+
+-define(SOCKADDR_IN4_DEFAULTS(A), #{port => 0,
+                                    addr => A}).
+-define(SOCKADDR_IN4_DEFAULTS,    ?SOCKADDR_IN4_DEFAULTS(any)).
+-define(SOCKADDR_IN4_DEFAULT(A),  (?SOCKADDR_IN4_DEFAULTS(A))#{family => inet}).
+-define(SOCKADDR_IN6_DEFAULTS(A), #{port     => 0,
+                                    addr     => A,
+                                    flowinfo => 0, 
+                                    scope_id => 0}).
+-define(SOCKADDR_IN6_DEFAULTS,    ?SOCKADDR_IN6_DEFAULTS(any)).
+-define(SOCKADDR_IN6_DEFAULT(A),  (?SOCKADDR_IN6_DEFAULTS(A))#{family => inet6}).
+
+%% otp    - This option is internal to our (OTP) implementation.
+%% socket - The socket layer (SOL_SOCKET).
+%% ip     - The IP layer (SOL_IP or is it IPPROTO_IP?).
+%% ipv6   - The IPv6 layer (SOL_IPV6).
+%% tcp    - The TCP (Transport Control Protocol) layer (IPPROTO_TCP).
+%% udp    - The UDP (User Datagram Protocol) layer (IPPROTO_UDP).
+%% sctp   - The SCTP (Stream Control Transmission Protocol) layer (IPPROTO_SCTP).
+%% Int    - Raw level, sent down and used "as is".
+%%          Its up to the caller to make sure this is correct!
+-type sockopt_level() :: otp |
+                         socket |
+                         ip | ipv6 | tcp | udp | sctp |
+                         non_neg_integer().
+
+%% There are some options that are 'read-only'.
+%% Should those be included here or in a special list?
+%% Should we just document it and leave it to the user?
+%% Or catch it in the encode functions?
+%% A setopt for a readonly option leads to einval?
+%% Do we really need a sndbuf?
+
+-type otp_socket_option() :: debug |
+                             iow |
+                             controlling_process |
+                             rcvbuf | % sndbuf |
+                             rcvctrlbuf |
+                             sndctrlbuf |
+                             fd.
+%% Shall we have special treatment of linger??
+%% read-only options:
+%% domain | protocol | type.
+%% FreeBSD (only?): acceptfilter
+-type socket_option() :: acceptconn |
+                         acceptfilter |
+                         bindtodevice |
+                         broadcast |
+                         busy_poll |
+                         debug |
+                         domain |
+                         dontroute |
+                         error |
+                         keepalive |
+                         linger |
+                         mark |
+                         oobinline |
+                         passcred |
+                         peek_off |
+                         peekcred |
+                         priority |
+                         protocol |
+                         rcvbuf |
+                         rcvbufforce |
+                         rcvlowat |
+                         rcvtimeo |
+                         reuseaddr |
+                         reuseport |
+                         rxq_ovfl |
+                         setfib |
+                         sndbuf |
+                         sndbufforce |
+                         sndlowat |
+                         sndtimeo |
+                         timestamp |
+                         type.
+
+%% Read-only options:
+%% mtu
+%%
+%% Options only valid on FreeBSD?:
+%% dontfrag
+%% Options only valid for RAW sockets:
+%% nodefrag (linux only?)
+-type ip_socket_option() :: add_membership |
+                            add_source_membership |
+                            block_source |
+                            dontfrag |
+                            drop_membership |
+                            drop_source_membership |
+                            freebind |
+                            hdrincl |
+                            minttl |
+                            msfilter |
+                            mtu |
+                            mtu_discover |
+                            multicast_all |
+                            multicast_if |
+                            multicast_loop |
+                            multicast_ttl |
+                            nodefrag |
+                            options |
+                            pktinfo |
+                            recverr |
+                            recvif |
+                            recvdstaddr |
+                            recvopts |
+                            recvorigdstaddr |
+                            recvtos |
+                            recvttl |
+                            retopts |
+                            router_alert |
+                            sndsrcaddr |
+                            tos |
+                            transparent |
+                            ttl |
+                            unblock_source.
+-type ipv6_socket_option() ::
+        addrform |
+        add_membership |
+        authhdr |
+        auth_level |
+        checksum |
+        drop_membership |
+        dstopts |
+        esp_trans_level |
+        esp_network_level |
+        faith |
+        flowinfo |
+        hoplimit |
+        hopopts |
+        ipcomp_level |
+        join_group |
+        leave_group |
+        mtu |
+        mtu_discover |
+        multicast_hops |
+        multicast_if |
+        multicast_loop |
+        portrange |
+        pktoptions |
+        recverr |
+        recvpktinfo | pktinfo |
+        recvtclass |
+        router_alert |
+        rthdr |
+        tclass |
+        unicast_hops |
+        use_min_mtu |
+        v6only.
+
+-type tcp_socket_option()  :: congestion |
+                              cork |
+                              info |
+                              keepcnt |
+                              keepidle |
+                              keepintvl |
+                              maxseg |
+                              md5sig |
+                              nodelay |
+                              noopt |
+                              nopush |
+                              syncnt |
+                              user_timeout.
+
+-type udp_socket_option() :: cork.
+
+-type sctp_socket_option() ::
+        adaption_layer |
+        associnfo |
+        auth_active_key |
+        auth_asconf |
+        auth_chunk |
+        auth_key |
+        auth_delete_key |
+        autoclose |
+        context |
+        default_send_params |
+        delayed_ack_time |
+        disable_fragments |
+        hmac_ident |
+        events |
+        explicit_eor |
+        fragment_interleave |
+        get_peer_addr_info |
+        initmsg |
+        i_want_mapped_v4_addr |
+        local_auth_chunks |
+        maxseg |
+        maxburst |
+        nodelay |
+        partial_delivery_point |
+        peer_addr_params |
+        peer_auth_chunks |
+        primary_addr |
+        reset_streams |
+        rtoinfo |
+        set_peer_primary_addr |
+        status |
+        use_ext_recvinfo.
+
+-type raw_socket_option() :: filter.
+
+%% -type plain_socket_option()  :: integer().
+%% -type sockopt() :: otp_socket_option() |
+%%                    socket_option() |
+%%                    ip_socket_option() |
+%%                    ipv6_socket_option() |
+%%                    tcp_socket_option() |
+%%                    udp_socket_option() |
+%%                    sctp_socket_option() |
+%%                    raw_socket_option() |
+%%                    plain_socket_option().
+
+-record(socket, {ref :: reference()}).
+
+-opaque socket() :: #socket{}.
+
+-type accept_flags() :: [accept_flag()].
+-type accept_flag()  :: nonblock | cloexec.
+
+-type send_flags() :: [send_flag()].
+-type send_flag()  :: confirm |
+                      dontroute |
+                      eor |
+                      more |
+                      nosignal |
+                      oob.
+
+%% Extend with OWN flags for other usage:
+%%   - adapt-buffer-sz:
+%%     This will have the effect that the nif recvfrom will use
+%%     MSG_PEEK to ensure no part of the message is lost, but if
+%%     necessary adapt (increase) the buffer size until all of
+%%     it fits.
+%%
+%% Note that not all of these flags are useful for every recv function!
+%%
+-type recv_flags() :: [recv_flag()].
+-type recv_flag()  :: cmsg_cloexec |
+                      errqueue |
+                      oob |
+                      peek |
+                      trunc.
+
+-type shutdown_how() :: read | write | read_write.
+
+-type msghdr_flag()  :: ctrunc | eor | errqueue | oob | trunc.
+-type msghdr_flags() :: [msghdr_flag()].
+-type msghdr() :: #{
+                    %% *Optional* target address
+                    %% Used on an unconnected socket to specify the 
+                    %% target address for a datagram.
+                    addr  := sockaddr(),
+                    
+                    iov   := [binary()],
+
+                    %% The maximum size of the control buffer is platform
+                    %% specific. It is the users responsibility to ensure 
+                    %% that its not exceeded.
+                    ctrl  := [cmsghdr_recv()] | [cmsghdr_send()],
+
+                    %% Only valid with recvmsg
+                    flags := msghdr_flags()
+                   }.
+%% We are able to (completely) decode *some* control message headers.
+%% Even if we are able to decode both level and type, we may not be
+%% able to decode the data, in which case it will be a binary.
+
+-type cmsghdr_level() :: socket | ip | ipv6 | integer().
+-type cmsghdr_type()  :: timestamp |
+                         pktinfo |
+                         tos |
+                         ttl |
+                         rights |
+                         credentials |
+                         origdstaddr |
+                         integer().
+-type cmsghdr_recv() :: 
+        #{level := socket,    type := timestamp,   data := timeval()}      |
+        #{level := socket,    type := rights,      data := binary()}       |
+        #{level := socket,    type := credentials, data := binary()}       |
+        #{level := socket,    type := integer(),   data := binary()}       |
+        #{level := ip,        type := tos,         data := ip_tos()}       |
+        #{level := ip,        type := ttl,         data := integer()}      |
+        #{level := ip,        type := pktinfo,     data := ip_pktinfo()}   |
+        #{level := ip,        type := origdstaddr, data := sockaddr_in4()} |
+        #{level := ip,        type := integer(),   data := binary()}       |
+        #{level := ipv6,      type := pktinfo,     data := ipv6_pktinfo()} |
+        #{level := ipv6,      type := integer(),   data := binary()}       |
+        #{level := integer(), type := integer(),   data := binary()}.
+-type cmsghdr_send() :: 
+        #{level := socket,    type := integer(), data := binary()} |
+        #{level := ip,        type := tos,       data := ip_tos()  | binary()} |
+        #{level := ip,        type := ttl,       data := integer() | binary()} |
+        #{level := ip,        type := integer(), data := binary()} |
+        #{level := ipv6,      type := integer(), data := binary()} |
+        #{level := udp,       type := integer(), data := binary()} |
+        #{level := integer(), type := integer(), data := binary()}.
+
+
+-opaque select_tag() :: atom().
+-opaque select_ref() :: reference().
+
+%% -record(select_info, {tag :: select_tag(), ref :: select_ref()}).
+
+-type select_info() :: {select_info, select_tag(), select_ref()}.
+
+-define(SELECT_INFO(T, R), {select_info, T, R}).
+-define(SELECT(T, R),      {select, ?SELECT_INFO(T, R)}).
+
+
+%% This is used in messages sent from the nif-code to erlang processes:
+%%
+%%         {?SOCKET_TAG, Socket :: socket(), Tag :: atom(), Info :: term()}
+%%
+-define(SOCKET_TAG, '$socket').
+
+-define(SOCKET_DOMAIN_LOCAL, 1).
+-define(SOCKET_DOMAIN_UNIX,  ?SOCKET_DOMAIN_LOCAL).
+-define(SOCKET_DOMAIN_INET,  2).
+-define(SOCKET_DOMAIN_INET6, 3).
+
+-define(SOCKET_TYPE_STREAM,    1).
+-define(SOCKET_TYPE_DGRAM,     2).
+-define(SOCKET_TYPE_RAW,       3).
+%% -define(SOCKET_TYPE_RDM,       4).
+-define(SOCKET_TYPE_SEQPACKET, 5).
+
+-define(SOCKET_PROTOCOL_DEFAULT, 0).
+-define(SOCKET_PROTOCOL_IP,      1).
+-define(SOCKET_PROTOCOL_TCP,     2).
+-define(SOCKET_PROTOCOL_UDP,     3).
+-define(SOCKET_PROTOCOL_SCTP,    4).
+-define(SOCKET_PROTOCOL_ICMP,    5).
+-define(SOCKET_PROTOCOL_IGMP,    6).
+
+-define(SOCKET_LISTEN_BACKLOG_DEFAULT, 5).
+
+-define(SOCKET_ACCEPT_TIMEOUT_DEFAULT, infinity).
+
+-define(SOCKET_SEND_FLAG_CONFIRM,    0).
+-define(SOCKET_SEND_FLAG_DONTROUTE,  1).
+-define(SOCKET_SEND_FLAG_EOR,        2).
+-define(SOCKET_SEND_FLAG_MORE,       3).
+-define(SOCKET_SEND_FLAG_NOSIGNAL,   4).
+-define(SOCKET_SEND_FLAG_OOB,        5).
+
+-define(SOCKET_SEND_FLAGS_DEFAULT,      []).
+-define(SOCKET_SEND_TIMEOUT_DEFAULT,    infinity).
+-define(SOCKET_SENDTO_FLAGS_DEFAULT,    []).
+-define(SOCKET_SENDTO_TIMEOUT_DEFAULT,  ?SOCKET_SEND_TIMEOUT_DEFAULT).
+-define(SOCKET_SENDMSG_FLAGS_DEFAULT,   []).
+-define(SOCKET_SENDMSG_TIMEOUT_DEFAULT, ?SOCKET_SEND_TIMEOUT_DEFAULT).
+
+-define(SOCKET_RECV_FLAG_CMSG_CLOEXEC, 0).
+-define(SOCKET_RECV_FLAG_ERRQUEUE,     1).
+-define(SOCKET_RECV_FLAG_OOB,          2).
+-define(SOCKET_RECV_FLAG_PEEK,         3).
+-define(SOCKET_RECV_FLAG_TRUNC,        4).
+
+-define(SOCKET_RECV_FLAGS_DEFAULT,   []).
+-define(SOCKET_RECV_TIMEOUT_DEFAULT, infinity).
+
+-define(SOCKET_OPT_LEVEL_OTP,            0).
+-define(SOCKET_OPT_LEVEL_SOCKET,         1).
+-define(SOCKET_OPT_LEVEL_IP,             2).
+-define(SOCKET_OPT_LEVEL_IPV6,           3).
+-define(SOCKET_OPT_LEVEL_TCP,            4).
+-define(SOCKET_OPT_LEVEL_UDP,            5).
+-define(SOCKET_OPT_LEVEL_SCTP,           6).
+
+%% *** OTP (socket) options
+-define(SOCKET_OPT_OTP_DEBUG,            1).
+-define(SOCKET_OPT_OTP_IOW,              2).
+-define(SOCKET_OPT_OTP_CTRL_PROC,        3).
+-define(SOCKET_OPT_OTP_RCVBUF,           4).
+%%-define(SOCKET_OPT_OTP_SNDBUF,           5).
+-define(SOCKET_OPT_OTP_RCVCTRLBUF,       6).
+-define(SOCKET_OPT_OTP_SNDCTRLBUF,       7).
+-define(SOCKET_OPT_OTP_FD,               8).
+-define(SOCKET_OPT_OTP_DOMAIN,           16#FF01). % INTERNAL
+-define(SOCKET_OPT_OTP_TYPE,             16#FF02). % INTERNAL
+-define(SOCKET_OPT_OTP_PROTOCOL,         16#FF03). % INTERNAL
+
+%% *** SOCKET (socket) options
+-define(SOCKET_OPT_SOCK_ACCEPTCONN,      1).
+%% -define(SOCKET_OPT_SOCK_ACCEPTFILTER,    2). % FreeBSD
+-define(SOCKET_OPT_SOCK_BINDTODEVICE,    3).
+-define(SOCKET_OPT_SOCK_BROADCAST,       4).
+%% -define(SOCKET_OPT_SOCK_BUSY_POLL,       5).
+-define(SOCKET_OPT_SOCK_DEBUG,           6).
+-define(SOCKET_OPT_SOCK_DOMAIN,          7).
+-define(SOCKET_OPT_SOCK_DONTROUTE,       8).
+%% -define(SOCKET_OPT_SOCK_ERROR,           9).
+-define(SOCKET_OPT_SOCK_KEEPALIVE,      10).
+-define(SOCKET_OPT_SOCK_LINGER,         11).
+%% -define(SOCKET_OPT_SOCK_MARK,           12).
+-define(SOCKET_OPT_SOCK_OOBINLINE,      13).
+%% -define(SOCKET_OPT_SOCK_PASSCRED,       14).
+-define(SOCKET_OPT_SOCK_PEEK_OFF,       15).
+%% -define(SOCKET_OPT_SOCK_PEEKCRED,       16).
+-define(SOCKET_OPT_SOCK_PRIORITY,       17).
+-define(SOCKET_OPT_SOCK_PROTOCOL,       18).
+-define(SOCKET_OPT_SOCK_RCVBUF,         19).
+%% -define(SOCKET_OPT_SOCK_RCVBUFFORCE,    20).
+-define(SOCKET_OPT_SOCK_RCVLOWAT,       21).
+-define(SOCKET_OPT_SOCK_RCVTIMEO,       22).
+-define(SOCKET_OPT_SOCK_REUSEADDR,      23).
+-define(SOCKET_OPT_SOCK_REUSEPORT,      24).
+%% -define(SOCKET_OPT_SOCK_RXQ_OVFL,       25).
+%% -define(SOCKET_OPT_SOCK_SETFIB,         26). % FreeBSD
+-define(SOCKET_OPT_SOCK_SNDBUF,         27).
+%% -define(SOCKET_OPT_SOCK_SNDBUFFORCE,    28).
+-define(SOCKET_OPT_SOCK_SNDLOWAT,       29).
+-define(SOCKET_OPT_SOCK_SNDTIMEO,       30).
+-define(SOCKET_OPT_SOCK_TIMESTAMP,      31).
+-define(SOCKET_OPT_SOCK_TYPE,           32).
+
+%% *** IP (socket) options
+-define(SOCKET_OPT_IP_ADD_MEMBERSHIP,         1).
+-define(SOCKET_OPT_IP_ADD_SOURCE_MEMBERSHIP,  2).
+-define(SOCKET_OPT_IP_BLOCK_SOURCE,           3).
+%% -define(SOCKET_OPT_IP_DONTFRAG,               4). % FreeBSD
+-define(SOCKET_OPT_IP_DROP_MEMBERSHIP,        5).
+-define(SOCKET_OPT_IP_DROP_SOURCE_MEMBERSHIP, 6).
+-define(SOCKET_OPT_IP_FREEBIND,               7).
+-define(SOCKET_OPT_IP_HDRINCL,                8).
+-define(SOCKET_OPT_IP_MINTTL,                 9).
+-define(SOCKET_OPT_IP_MSFILTER,              10).
+-define(SOCKET_OPT_IP_MTU,                   11).
+-define(SOCKET_OPT_IP_MTU_DISCOVER,          12).
+-define(SOCKET_OPT_IP_MULTICAST_ALL,         13).
+-define(SOCKET_OPT_IP_MULTICAST_IF,          14).
+-define(SOCKET_OPT_IP_MULTICAST_LOOP,        15).
+-define(SOCKET_OPT_IP_MULTICAST_TTL,         16).
+-define(SOCKET_OPT_IP_NODEFRAG,              17).
+%% -define(SOCKET_OPT_IP_OPTIONS,               18). % FreeBSD
+-define(SOCKET_OPT_IP_PKTINFO,               19).
+-define(SOCKET_OPT_IP_RECVDSTADDR,           20). % FreeBSD
+-define(SOCKET_OPT_IP_RECVERR,               21).
+-define(SOCKET_OPT_IP_RECVIF,                22).
+-define(SOCKET_OPT_IP_RECVOPTS,              23).
+-define(SOCKET_OPT_IP_RECVORIGDSTADDR,       24).
+-define(SOCKET_OPT_IP_RECVTOS,               25).
+-define(SOCKET_OPT_IP_RECVTTL,               26).
+-define(SOCKET_OPT_IP_RETOPTS,               27).
+-define(SOCKET_OPT_IP_ROUTER_ALERT,          28).
+-define(SOCKET_OPT_IP_SENDSRCADDR,           29). % FreeBSD
+-define(SOCKET_OPT_IP_TOS,                   30).
+-define(SOCKET_OPT_IP_TRANSPARENT,           31).
+-define(SOCKET_OPT_IP_TTL,                   32).
+-define(SOCKET_OPT_IP_UNBLOCK_SOURCE,        33).
+
+%% *** IPv6 (socket) options
+-define(SOCKET_OPT_IPV6_ADDRFORM,           1).
+-define(SOCKET_OPT_IPV6_ADD_MEMBERSHIP,     2).
+-define(SOCKET_OPT_IPV6_AUTHHDR,            3). % Obsolete?
+%% -define(SOCKET_OPT_IPV6_AUTH_LEVEL,         4). % FreeBSD
+%% -define(SOCKET_OPT_IPV6_CHECKSUM,           5). % FreeBSD
+-define(SOCKET_OPT_IPV6_DROP_MEMBERSHIP,    6).
+-define(SOCKET_OPT_IPV6_DSTOPTS,            7).
+%% -define(SOCKET_OPT_IPV6_ESP_NETWORK_LEVEL,  8). % FreeBSD
+%% -define(SOCKET_OPT_IPV6_ESP_TRANS_LEVEL,    9). % FreeBSD
+%% -define(SOCKET_OPT_IPV6_FAITH,             10). % FreeBSD
+-define(SOCKET_OPT_IPV6_FLOWINFO,          11).
+-define(SOCKET_OPT_IPV6_HOPLIMIT,          12).
+-define(SOCKET_OPT_IPV6_HOPOPTS,           13).
+%% -define(SOCKET_OPT_IPV6_IPCOMP_LEVEL,      14). % FreeBSD
+%% -define(SOCKET_OPT_IPV6_JOIN_GROUP,        15). % FreeBSD
+%% -define(SOCKET_OPT_IPV6_LEAVE_GROUP,       16). % FreeBSD
+-define(SOCKET_OPT_IPV6_MTU,               17).
+-define(SOCKET_OPT_IPV6_MTU_DISCOVER,      18).
+-define(SOCKET_OPT_IPV6_MULTICAST_HOPS,    19).
+-define(SOCKET_OPT_IPV6_MULTICAST_IF,      20).
+-define(SOCKET_OPT_IPV6_MULTICAST_LOOP,    21).
+%% -define(SOCKET_OPT_IPV6_PORTRANGE,         22). % FreeBSD
+%% -define(SOCKET_OPT_IPV6_PKTOPTIONS,        23). % FreeBSD
+-define(SOCKET_OPT_IPV6_RECVERR,           24).
+-define(SOCKET_OPT_IPV6_RECVPKTINFO,       25). % On FreeBSD: PKTINFO
+%% -define(SOCKET_OPT_IPV6_RECVTCLASS,        26).
+-define(SOCKET_OPT_IPV6_ROUTER_ALERT,      27).
+-define(SOCKET_OPT_IPV6_RTHDR,             28).
+%% -define(SOCKET_OPT_IPV6_TCLASS,            29). % FreeBSD
+-define(SOCKET_OPT_IPV6_UNICAST_HOPS,      30).
+%% -define(SOCKET_OPT_IPV6_USE_MIN_MTU,       31). % FreeBSD
+-define(SOCKET_OPT_IPV6_V6ONLY,            32).
+
+%% *** TCP (socket) options
+-define(SOCKET_OPT_TCP_CONGESTION,      1).
+-define(SOCKET_OPT_TCP_CORK,            2).
+%% -define(SOCKET_OPT_TCP_INFO,            3).
+%% -define(SOCKET_OPT_TCP_KEEPCNT,         4).
+%% -define(SOCKET_OPT_TCP_KEEPIDLE,        5).
+%% -define(SOCKET_OPT_TCP_KEEPINTVL,       6).
+-define(SOCKET_OPT_TCP_MAXSEG,          7).
+%% -define(SOCKET_OPT_TCP_MD5SIG,          8).
+-define(SOCKET_OPT_TCP_NODELAY,         9).
+%% -define(SOCKET_OPT_TCP_NOOPT,          10).
+%% -define(SOCKET_OPT_TCP_NOPUSH,         11).
+%% -define(SOCKET_OPT_TCP_SYNCNT,         12).
+%% -define(SOCKET_OPT_TCP_USER_TIMEOUT,   13).
+
+%% *** UDP (socket) options
+-define(SOCKET_OPT_UDP_CORK,            1).
+
+%% *** SCTP (socket) options
+%% -define(SOCKET_OPT_SCTP_ADAPTION_LAYER,          1).
+-define(SOCKET_OPT_SCTP_ASSOCINFO,               2).
+%% -define(SOCKET_OPT_SCTP_AUTH_ACTIVE_KEY,         3).
+%% -define(SOCKET_OPT_SCTP_AUTH_ASCONF,             4).
+%% -define(SOCKET_OPT_SCTP_AUTH_CHUNK,              5).
+%% -define(SOCKET_OPT_SCTP_AUTH_KEY,                6).
+%% -define(SOCKET_OPT_SCTP_AUTH_DELETE_KEY,         7).
+-define(SOCKET_OPT_SCTP_AUTOCLOSE,               8).
+%% -define(SOCKET_OPT_SCTP_CONTEXT,                 9).
+%% -define(SOCKET_OPT_SCTP_DEFAULT_SEND_PARAMS,    10).
+%% -define(SOCKET_OPT_SCTP_DELAYED_ACK_TIME,       11).
+-define(SOCKET_OPT_SCTP_DISABLE_FRAGMENTS,      12).
+%% -define(SOCKET_OPT_SCTP_HMAC_IDENT,             13).
+-define(SOCKET_OPT_SCTP_EVENTS,                 14).
+%% -define(SOCKET_OPT_SCTP_EXPLICIT_EOR,           15).
+%% -define(SOCKET_OPT_SCTP_FRAGMENT_INTERLEAVE,    16).
+%% -define(SOCKET_OPT_SCTP_GET_PEER_ADDR_INFO,     17).
+-define(SOCKET_OPT_SCTP_INITMSG,                18).
+%% -define(SOCKET_OPT_SCTP_I_WANT_MAPPED_V4_ADDR,  19).
+%% -define(SOCKET_OPT_SCTP_LOCAL_AUTH_CHUNKS,      20).
+-define(SOCKET_OPT_SCTP_MAXSEG,                 21).
+%% -define(SOCKET_OPT_SCTP_MAXBURST,               22).
+-define(SOCKET_OPT_SCTP_NODELAY,                23).
+%% -define(SOCKET_OPT_SCTP_PARTIAL_DELIVERY_POINT, 24).
+%% -define(SOCKET_OPT_SCTP_PEER_ADDR_PARAMS,       25).
+%% -define(SOCKET_OPT_SCTP_PEER_AUTH_CHUNKS,       26).
+%% -define(SOCKET_OPT_SCTP_PRIMARY_ADDR,           27).
+%% -define(SOCKET_OPT_SCTP_RESET_STREAMS,          28).
+-define(SOCKET_OPT_SCTP_RTOINFO,                29).
+%% -define(SOCKET_OPT_SCTP_SET_PEER_PRIMARY_ADDR,  30).
+%% -define(SOCKET_OPT_SCTP_STATUS,                 31).
+%% -define(SOCKET_OPT_SCTP_USE_EXT_RECVINFO,       32).
+
+-define(SOCKET_SHUTDOWN_HOW_READ,       0).
+-define(SOCKET_SHUTDOWN_HOW_WRITE,      1).
+-define(SOCKET_SHUTDOWN_HOW_READ_WRITE, 2).
+
+
+-define(SOCKET_SUPPORTS_OPTIONS, 16#0001).
+-define(SOCKET_SUPPORTS_SCTP,    16#0002).
+-define(SOCKET_SUPPORTS_IPV6,    16#0003).
+-define(SOCKET_SUPPORTS_LOCAL,   16#0004).
+
+
+%% ===========================================================================
+%%
+%% Administrative and utility API
+%%
+%% ===========================================================================
+
+-spec on_load() -> ok.
+
+%% Should we require that the Extra arg is a map?
+on_load() ->
+    on_load(#{}).
+
+-spec on_load(Extra) -> ok when
+      Extra :: map().
+
+on_load(Extra) ->
+    ok = erlang:load_nif(atom_to_list(?MODULE), Extra).
+
+
+
+-spec info() -> map().
+
+info() ->
+    nif_info().
+
+
+-spec debug(D) -> ok when
+      D :: boolean().
+
+debug(D) when is_boolean(D) ->
+    command(#{command => debug,
+              data    => D}).
+
+
+-spec command(Command) -> ok when
+      Command :: debug_command().
+
+command(#{command := debug,
+          data    := Dbg} = Command) when is_boolean(Dbg) ->
+    nif_command(Command).
+
+
+
+%% ===========================================================================
+%%
+%% info - Get miscellaneous information about a socket.
+%%
+%% Generates a list of various info about the socket, such as counter values.
+%%
+%% Do *not* call this function often.
+%% 
+%% ===========================================================================
+
+-spec info(Socket) -> socket_info() when
+      Socket :: socket().
+
+info(#socket{ref = SockRef}) ->
+    nif_info(SockRef).
+
+
+
+%% ===========================================================================
+%%
+%% supports - get information about what the platform "supports".
+%%
+%% Generates a list of various info about what the plaform can support. 
+%% The most obvious case is 'options'. 
+%%
+%% Each item in a 'supports'-list will appear only *one* time.
+%% 
+%% ===========================================================================
+
+-type supports_options_socket() :: [{socket_option(),      boolean()}].
+-type supports_options_ip()     :: [{ip_socket_option(),   boolean()}].
+-type supports_options_ipv6()   :: [{ipv6_socket_option(), boolean()}].
+-type supports_options_tcp()    :: [{tcp_socket_option(),  boolean()}].
+-type supports_options_udp()    :: [{udp_socket_option(),  boolean()}].
+-type supports_options_sctp()   :: [{sctp_socket_option(), boolean()}].
+-type supports_options() :: [{socket, supports_options_socket()} |
+                             {ip,     supports_options_ip()}     |
+                             {ipv6,   supports_options_ipv6()}   |
+                             {tcp,    supports_options_tcp()}    |
+                             {udp,    supports_options_udp()}    |
+                             {sctp,   supports_options_sctp()}].
+
+-spec supports() -> [{options, supports_options()} | 
+                     {sctp,    boolean()} |
+                     {ipv6,    boolean()} |
+                     {local,   boolean()}].
+
+supports() ->
+    [{options, supports(options)},
+     {sctp,    supports(sctp)},
+     {ipv6,    supports(ipv6)},
+     {local,   supports(local)}].
+
+
+-dialyzer({nowarn_function, supports/1}).
+-spec supports(options) -> supports_options();
+              (sctp)    -> boolean();
+              (ipv6)    -> boolean();
+              (local)   -> boolean();
+              (Key1)    -> false when
+      Key1 :: term().
+                        
+supports(options) ->
+    nif_supports(?SOCKET_SUPPORTS_OPTIONS);
+supports(sctp) ->
+    nif_supports(?SOCKET_SUPPORTS_SCTP);
+supports(ipv6) ->
+    nif_supports(?SOCKET_SUPPORTS_IPV6);
+supports(local) ->
+    nif_supports(?SOCKET_SUPPORTS_LOCAL);
+supports(_Key1) ->
+    false.
+
+-dialyzer({nowarn_function, supports/2}).
+-spec supports(options, socket) -> supports_options_socket();
+              (options, ip) -> supports_options_ip();
+              (options, ipv6) -> supports_options_ipv6();
+              (options, tcp) -> supports_options_tcp();
+              (options, udp) -> supports_options_udp();
+              (options, sctp) -> supports_options_sctp();
+              (Key1, Key2) -> false when
+      Key1 :: term(),
+      Key2 :: term().
+
+supports(options, Level) ->
+    proplists:get_value(Level, supports(options), false);
+supports(_Key1, _Level) ->
+    false.
+
+
+-dialyzer({nowarn_function, supports/3}).
+-spec supports(options, socket, Opt) -> boolean() when
+      Opt :: socket_option();
+              (options, ip, Opt) -> boolean() when
+      Opt :: ip_socket_option();
+              (options, ipv6, Opt) -> boolean() when
+      Opt :: ipv6_socket_option();
+              (options, tcp, Opt) -> boolean() when
+      Opt :: tcp_socket_option();
+              (options, udp, Opt) -> boolean() when
+      Opt :: udp_socket_option();
+              (options, sctp, Opt) -> boolean() when
+      Opt :: sctp_socket_option();
+              (Key1, Key2, Key3) -> false when
+      Key1 :: term(),
+      Key2 :: term(),
+      Key3 :: term().
+
+supports(options, Level, Opt) ->
+    case supports(options, Level) of
+        S when is_list(S) ->
+            proplists:get_value(Opt, S, false);
+        _ ->
+            false
+    end;
+supports(_Key1, _Key2, _Key3) ->
+    false.
+
+
+
+%% ===========================================================================
+%%
+%% The proper socket API
+%%
+%% ===========================================================================
+
+%% ===========================================================================
+%%
+%% <KOLLA>
+%%
+%% How do we handle the case when an fd has been created (somehow)
+%% and we shall create a socket "from it".
+%% Can we figure out Domain, Type and Protocol from fd?
+%% No we can't: For instance, its not possible to 'get' domain on FreeBSD.
+%% 
+%% Instead, require: open(Domain, Stream, Proto, #{fd => FD}).
+%% The last argument, Extra, is used to provide the fd.
+%% 
+%% </KOLLA>
+%%
+%%
+%% <KOLLA>
+%%
+%% Possibly add a "registry" in the nif, allowing the user processes to 
+%% "register" themselves.
+%% The point of this would be to ensure that these processes are
+%% informed if the socket "terminates". Could possibly be used for
+%% other things? If gen_tcp implements the active feature using
+%% a reader process, the nif may need to know about this process,
+%% since its probably "hidden" from the socket "owner" (someone
+%% needs to handle it if it dies).
+%% Register under a name?
+%%
+%% The nif sets up a monitor to this process, and if it dies the socket
+%% is closed. It is also used if someone wants to monitor the socket.
+%%
+%% We may therefor need monitor function(s): 
+%%
+%%               socket:monitor(Socket)
+%%               socket:demonitor(Socket)
+%%
+%% </KOLLA>
+%%
+
+
+
+%% ===========================================================================
+%%
+%% open - create an endpoint for communication
+%%
+%% Extra: Currently only used for netns
+%%
+
+-spec open(Domain, Type) -> {ok, Socket} | {error, Reason} when
+      Domain   :: domain(),
+      Type     :: type(),
+      Socket   :: socket(),
+      Reason   :: term().
+
+open(Domain, Type) ->
+    open(Domain, Type, default).
+
+-spec open(Domain, Type, Protocol) -> {ok, Socket} | {error, Reason} when
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: default | protocol(),
+      Socket   :: socket(),
+      Reason   :: term().
+
+open(Domain, Type, Protocol) ->
+    open(Domain, Type, Protocol, #{}).
+
+-spec open(Domain, Type, Protocol, Extra) -> {ok, Socket} | {error, Reason} when
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: default | protocol(),
+      Extra    :: map(),
+      Socket   :: socket(),
+      Reason   :: term().
+
+open(Domain, Type, Protocol, Extra) when is_map(Extra) ->
+    try
+        begin
+            EDomain   = enc_domain(Domain),
+            EType     = enc_type(Domain, Type),
+            EProtocol = enc_protocol(Type, Protocol),
+            case nif_open(EDomain, EType, EProtocol, Extra) of
+                {ok, SockRef} ->
+                    Socket = #socket{ref = SockRef},
+                    {ok, Socket};
+                {error, _} = ERROR ->
+                    ERROR
+            end
+        end
+    catch
+        throw:T ->
+            T;
+        %% <WIN32-TEMPORARY>
+        error:notsup:S ->
+            erlang:raise(error, notsup, S);
+        %% </WIN32-TEMPORARY>
+        error:Reason ->
+            {error, Reason}
+    end.
+
+
+
+%% ===========================================================================
+%%
+%% bind - bind a name to a socket
+%%
+%% Note that Addr can only have the value of broadcast *if* Domain =:= inet!
+%%
+
+-spec bind(Socket, Addr) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Addr   :: any | broadcast | loopback | sockaddr(),
+      Reason :: term().
+
+bind(#socket{ref = SockRef}, Addr)
+  when ((Addr =:= any) orelse
+	(Addr =:= broadcast) orelse
+	(Addr =:= loopback)) ->
+    try which_domain(SockRef) of
+        inet ->
+            nif_bind(SockRef, ?SOCKADDR_IN4_DEFAULT(Addr));
+        inet6 when (Addr =:= any) orelse (Addr =:= loopback) ->
+            nif_bind(SockRef, ?SOCKADDR_IN6_DEFAULT(Addr));
+	_ ->
+	    einval()
+    catch
+        %% <WIN32-TEMPORARY>
+        error:notsup:S ->
+            erlang:raise(error, notsup, S);
+        %% </WIN32-TEMPORARY>
+        throw:ERROR ->
+            ERROR
+    end;
+bind(#socket{ref = SockRef} = _Socket, Addr) when is_map(Addr) ->
+    try
+        begin
+            nif_bind(SockRef, ensure_sockaddr(Addr))
+        end
+    catch
+        %% <WIN32-TEMPORARY>
+        error:notsup:S ->
+            erlang:raise(error, notsup, S);
+        %% </WIN32-TEMPORARY>
+        throw:ERROR ->
+            ERROR
+    end.
+
+
+
+%% ===========================================================================
+%%
+%% bind - Add or remove a bind addresses on a socket
+%%
+%% Calling this function is only valid if the socket is: 
+%%   type     = seqpacket
+%%   protocol = sctp
+%%
+%% If the domain is inet, then all addresses *must* be IPv4.
+%% If the domain is inet6, the addresses can be aither IPv4 or IPv6.
+%%
+
+-spec bind(Socket, Addrs, Action) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Addrs  :: [sockaddr()],
+      Action :: add | remove,
+      Reason :: term().
+
+bind(#socket{ref = SockRef}, Addrs, Action) 
+  when is_list(Addrs) andalso ((Action =:= add) orelse (Action =:= remove)) ->
+    try
+        begin
+            ensure_type(SockRef, seqpacket),
+            ensure_proto(SockRef, sctp),
+            validate_addrs(which_domain(SockRef), Addrs),
+            nif_bind(SockRef, Addrs, Action)
+        end
+    catch
+        %% <WIN32-TEMPORARY>
+        error:notsup:S ->
+            erlang:raise(error, notsup, S);
+        %% </WIN32-TEMPORARY>
+        throw:ERROR ->
+            ERROR
+    end.
+
+ensure_type(SockRef, Type) ->
+    case which_type(SockRef) of
+        Type ->
+            ok;
+        _InvalidType ->
+            einval()
+    end.
+
+ensure_proto(SockRef, Proto) ->
+    case which_protocol(SockRef) of
+        Proto ->
+            ok;
+        _InvalidProto ->
+            einval()
+    end.
+
+validate_addrs(inet = _Domain, Addrs) ->
+    validate_inet_addrs(Addrs);
+validate_addrs(inet6 = _Domain, Addrs) ->
+    validate_inet6_addrs(Addrs).
+
+validate_inet_addrs(Addrs) ->
+    Validator = fun(#{family := inet,
+                      addrs  := Addr}) when is_tuple(Addr) andalso 
+                                            (size(Addr) =:= 4) ->
+                        ok;
+                   (X) ->
+                        throw({error, {invalid_address, X}})
+                end,
+    lists:foreach(Validator, Addrs).
+
+validate_inet6_addrs(Addrs) ->
+    Validator = fun(#{family := inet,
+                      addrs  := Addr}) when is_tuple(Addr) andalso 
+                                            (size(Addr) =:= 4) ->
+                        ok;
+                   (#{family := inet6,
+                      addrs  := Addr}) when is_tuple(Addr) andalso 
+                                            (size(Addr) =:= 8) ->
+                        ok;
+                   (X) ->
+                        throw({error, {invalid_address, X}})
+                end,
+    lists:foreach(Validator, Addrs).
+
+
+%% ===========================================================================
+%%
+%% connect - initiate a connection on a socket
+%%
+
+-spec connect(Socket, SockAddr) -> ok | {error, Reason} when
+    Socket   :: socket(),
+    SockAddr :: sockaddr(),
+    Reason   :: term().
+
+connect(Socket, SockAddr) ->
+    connect(Socket, SockAddr, infinity).
+
+-spec connect(Socket, SockAddr, nowait) ->
+           ok | {select, SelectInfo} | {error, Reason} when
+    Socket     :: socket(),
+    SockAddr   :: sockaddr(),
+    SelectInfo :: select_info(),
+    Reason     :: term()
+        ; (Socket, SockAddr, Timeout) -> ok | {error, Reason} when
+    Socket   :: socket(),
+    SockAddr :: sockaddr(),
+    Timeout  :: timeout(),
+    Reason   :: term().
+
+%% <KOLLA>
+%% Is it possible to connect with family = local for the (dest) sockaddr?
+%% </KOLLA>
+connect(_Socket, _SockAddr, Timeout)
+  when (is_integer(Timeout) andalso (Timeout =< 0)) ->
+    {error, timeout};
+connect(#socket{ref = SockRef}, #{family := Fam} = SockAddr, Timeout)
+  when ((Fam =:= inet) orelse (Fam =:= inet6) orelse (Fam =:= local)) andalso
+       ((Timeout =:= nowait) orelse 
+        (Timeout =:= infinity) orelse is_integer(Timeout)) ->
+    TS = timestamp(Timeout),
+    case nif_connect(SockRef, ensure_sockaddr(SockAddr)) of
+        ok ->
+            %% Connected!
+            ok;
+
+        {ok, Ref} when (Timeout =:= nowait) ->
+            %% Connecting, but the caller does not want to wait...
+            ?SELECT(connect, Ref);
+
+        {ok, Ref} ->
+            %% Connecting...
+	    NewTimeout = next_timeout(TS, Timeout),
+	    receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, Ref} -> 
+		    nif_finalize_connection(SockRef)
+	    after NewTimeout ->
+                    cancel(SockRef, connect, Ref),
+		    {error, timeout}
+	    end;
+	{error, _} = ERROR ->
+	    ERROR
+    end.
+
+
+%% ===========================================================================
+%%
+%% listen - listen for connections on a socket
+%%
+
+-spec listen(Socket) -> ok | {error, Reason} when
+      Socket  :: socket(),
+      Reason  :: term().
+
+listen(Socket) ->
+    listen(Socket, ?SOCKET_LISTEN_BACKLOG_DEFAULT).
+
+-spec listen(Socket, Backlog) -> ok | {error, Reason} when
+      Socket  :: socket(),
+      Backlog :: pos_integer(),
+      Reason  :: term().
+
+listen(#socket{ref = SockRef}, Backlog)
+  when (is_integer(Backlog) andalso (Backlog >= 0)) ->
+    nif_listen(SockRef, Backlog).
+
+
+
+
+%% ===========================================================================
+%%
+%% accept, accept4 - accept a connection on a socket
+%%
+
+-spec accept(LSocket) -> {ok, Socket} | {error, Reason} when
+      LSocket :: socket(),
+      Socket  :: socket(),
+      Reason  :: term().
+
+accept(Socket) ->
+    accept(Socket, ?SOCKET_ACCEPT_TIMEOUT_DEFAULT).
+
+-spec accept(LSocket, nowait) -> 
+                    {ok, Socket} |
+                    {select, SelectInfo} |
+                    {error, Reason} when
+      LSocket    :: socket(),
+      Socket     :: socket(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (LSocket, Timeout) -> {ok, Socket} | {error, Reason} when
+      LSocket    :: socket(),
+      Timeout    :: timeout(),
+      Socket     :: socket(),
+      Reason     :: term().
+
+%% Do we really need this optimization?
+accept(_, Timeout) when is_integer(Timeout) andalso (Timeout =< 0) ->
+    {error, timeout};
+accept(#socket{ref = LSockRef}, Timeout)
+  when is_integer(Timeout) orelse
+       (Timeout =:= infinity)  orelse
+       (Timeout =:= nowait) ->
+    do_accept(LSockRef, Timeout).
+
+do_accept(LSockRef, Timeout) ->
+    TS     = timestamp(Timeout),
+    AccRef = make_ref(),
+    case nif_accept(LSockRef, AccRef) of
+        {ok, SockRef} ->
+            Socket = #socket{ref = SockRef},
+            {ok, Socket};
+
+
+        {error, eagain} when (Timeout =:= nowait) ->
+            ?SELECT(accept, AccRef);
+
+
+        {error, eagain} ->
+            %% Each call is non-blocking, but even then it takes
+            %% *some* time, so just to be sure, recalculate before 
+            %% the receive.
+	    NewTimeout = next_timeout(TS, Timeout),
+            receive
+                {?SOCKET_TAG, #socket{ref = LSockRef}, select, AccRef} -> 
+                    do_accept(LSockRef, next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {AccRef, Reason}} ->
+                    {error, Reason}
+
+            after NewTimeout ->
+                    cancel(LSockRef, accept, AccRef),
+                    {error, timeout}
+            end;
+
+        {error, _} = ERROR ->
+            cancel(LSockRef, accept, AccRef), % Just to be on the safe side...
+            ERROR
+    end.
+
+
+
+%% ===========================================================================
+%%
+%% send, sendto, sendmsg - send a message on a socket
+%%
+
+-spec send(Socket, Data) -> ok | {error, Reason} when
+      Socket  :: socket(),
+      Data    :: iodata(),
+      Reason  :: term().
+
+send(Socket, Data) ->
+    send(Socket, Data, ?SOCKET_SEND_FLAGS_DEFAULT, ?SOCKET_SEND_TIMEOUT_DEFAULT).
+
+-spec send(Socket, Data, Flags) -> ok | {error, Reason} when
+      Socket     :: socket(),
+      Data       :: iodata(),
+      Flags      :: send_flags(),
+      Reason     :: term()
+                 ; (Socket, Data, Timeout :: nowait) -> ok |
+                                             {select, SelectInfo} |
+                                             {ok, {RestData, SelectInfo}} |
+                                             {error, Reason} when
+      Socket     :: socket(),
+      Data       :: iodata(),
+      RestData   :: binary(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, Data, Timeout) -> ok | {error, Reason} when
+      Socket     :: socket(),
+      Data       :: iodata(),
+      Timeout    :: timeout(),
+      Reason     :: term().
+
+send(Socket, Data, Flags) when is_list(Flags) ->
+    send(Socket, Data, Flags, ?SOCKET_SEND_TIMEOUT_DEFAULT);
+send(Socket, Data, Timeout) ->
+    send(Socket, Data, ?SOCKET_SEND_FLAGS_DEFAULT, Timeout).
+
+-spec send(Socket, Data, Flags, nowait) -> ok |
+                                           {select, SelectInfo} |
+                                           {ok, {RestData, SelectInfo}} |
+                                           {error, Reason} when
+      Socket     :: socket(),
+      Data       :: iodata(),
+      Flags      :: send_flags(),
+      RestData   :: binary(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, Data, Flags, Timeout) -> ok | {error, Reason} when
+      Socket     :: socket(),
+      Data       :: iodata(),
+      Flags      :: send_flags(),
+      Timeout    :: timeout(),
+      Reason     :: term().
+
+send(Socket, Data, Flags, Timeout) when is_list(Data) ->
+    Bin = erlang:list_to_binary(Data),
+    send(Socket, Bin, Flags, Timeout);
+send(#socket{ref = SockRef}, Data, Flags, Timeout)
+  when is_binary(Data) andalso 
+       is_list(Flags) andalso
+       ((Timeout =:= nowait) orelse
+        (Timeout =:= infinity) orelse
+        (is_integer(Timeout) andalso (Timeout > 0)))  ->
+    EFlags = enc_send_flags(Flags),
+    do_send(SockRef, Data, EFlags, Timeout).
+
+do_send(SockRef, Data, EFlags, Timeout) ->
+    TS      = timestamp(Timeout),
+    SendRef = make_ref(),
+    case nif_send(SockRef, SendRef, Data, EFlags) of
+        ok ->
+            ok;
+
+
+        {ok, Written} when (Timeout =:= nowait) ->
+            <<_:Written/binary, Rest/binary>> = Data,
+	    %% We are partially done, but the user don't want to wait (here) 
+            %% for completion
+            {ok, {Rest, ?SELECT_INFO(send, SendRef)}};
+
+
+        {ok, Written} ->
+	    NewTimeout = next_timeout(TS, Timeout),
+	    %% We are partially done, wait for continuation
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, SendRef} 
+                  when (Written > 0) -> 
+                    <<_:Written/binary, Rest/binary>> = Data,
+                    do_send(SockRef, Rest, EFlags,
+                            next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, SendRef} ->
+                    do_send(SockRef, Data, EFlags,
+                            next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {SendRef, Reason}} ->
+                    {error, Reason}
+
+            after NewTimeout ->
+                    cancel(SockRef, send, SendRef),
+                    {error, {timeout, size(Data)}}
+            end;
+
+
+        {error, eagain} when (Timeout =:= nowait) ->
+            ?SELECT(send, SendRef);
+
+
+        {error, eagain} ->
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, SendRef} ->
+                    do_send(SockRef, Data, EFlags,
+                            next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {SendRef, Reason}} ->
+                    {error, Reason}
+
+            after Timeout ->
+                    cancel(SockRef, send, SendRef),
+                    {error, {timeout, size(Data)}}
+            end;
+
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+
+
+
+%% ---------------------------------------------------------------------------
+%%
+
+-spec sendto(Socket, Data, Dest) ->
+                    ok | {error, Reason} when
+      Socket :: socket(),
+      Data   :: binary(),
+      Dest   :: sockaddr(),
+      Reason :: term().
+
+sendto(Socket, Data, Dest) ->
+    sendto(Socket, Data, Dest, ?SOCKET_SENDTO_FLAGS_DEFAULT).
+
+-spec sendto(Socket, Data, Dest, Flags) -> ok | {error, Reason} when
+      Socket    :: socket(),
+      Data      :: binary(),
+      Dest      :: sockaddr(),
+      Flags     :: send_flags(),
+      Reason    :: term()
+                   ; (Socket, Data, Dest, Timeout :: nowait) -> ok |
+                                                  {select, SelectInfo} |
+                                                  {error, Reason} when
+      Socket     :: socket(),
+      Data       :: iodata(),
+      Dest       :: sockaddr(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, Data, Dest, Timeout) -> ok | {error, Reason} when
+      Socket     :: socket(),
+      Data       :: iodata(),
+      Dest       :: sockaddr(),
+      Timeout    :: timeout(),
+      Reason     :: term().
+
+sendto(Socket, Data, Dest, Flags) when is_list(Flags) ->
+    sendto(Socket, Data, Dest, Flags, ?SOCKET_SENDTO_TIMEOUT_DEFAULT);
+sendto(Socket, Data, Dest, Timeout) ->
+    sendto(Socket, Data, Dest, ?SOCKET_SENDTO_FLAGS_DEFAULT, Timeout).
+
+
+-spec sendto(Socket, Data, Dest, Flags, nowait) -> ok |
+                                                   {select, SelectInfo} |
+                                                   {error, Reason} when
+      Socket     :: socket(),
+      Data       :: binary(),
+      Dest       :: sockaddr(),
+      Flags      :: send_flags(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, Data, Dest, Flags, Timeout) -> ok | {error, Reason} when
+      Socket     :: socket(),
+      Data       :: binary(),
+      Dest       :: sockaddr(),
+      Flags      :: send_flags(),
+      Timeout    :: timeout(),
+      Reason     :: term().
+
+sendto(Socket, Data, Dest, Flags, Timeout) when is_list(Data) ->
+    Bin = erlang:list_to_binary(Data),
+    sendto(Socket, Bin, Dest, Flags, Timeout);
+sendto(#socket{ref = SockRef}, Data, #{family := Fam} = Dest, Flags, Timeout)
+  when is_binary(Data) andalso
+       ((Fam =:= inet) orelse (Fam =:= inet6) orelse (Fam =:= local)) andalso 
+       is_list(Flags) andalso
+       ((Timeout =:= nowait) orelse
+        (Timeout =:= infinity) orelse
+        (is_integer(Timeout) andalso (Timeout > 0))) ->
+    EFlags = enc_send_flags(Flags),
+    do_sendto(SockRef, Data, ensure_sockaddr(Dest), EFlags, Timeout).
+
+do_sendto(SockRef, Data, Dest, EFlags, Timeout) ->
+    TS      = timestamp(Timeout),
+    SendRef = make_ref(),
+    case nif_sendto(SockRef, SendRef, Data, Dest, EFlags) of
+        ok ->
+            %% We are done
+            ok;
+
+        {ok, Written} when (Timeout =:= nowait) ->
+            <<_:Written/binary, Rest/binary>> = Data,
+            {ok, {Rest, ?SELECT_INFO(sendto, SendRef)}};
+
+
+        {ok, Written} ->
+	    %% We are partially done, wait for continuation
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, SendRef} 
+                  when (Written > 0) ->
+                    <<_:Written/binary, Rest/binary>> = Data,
+                    do_sendto(SockRef, Rest, Dest, EFlags,
+                              next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, SendRef} ->
+                    do_sendto(SockRef, Data, Dest, EFlags,
+                              next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {SendRef, Reason}} ->
+                    {error, Reason}
+
+            after Timeout ->
+                    cancel(SockRef, sendto, SendRef),
+                    {error, timeout}
+            end;
+
+
+        {error, eagain} when (Timeout =:= nowait) ->
+            ?SELECT(sendto, SendRef);
+
+
+        {error, eagain} ->
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, SendRef} ->
+                    do_sendto(SockRef, Data, Dest, EFlags, 
+                              next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {SendRef, Reason}} ->
+                    {error, Reason}
+
+            after Timeout ->
+                    cancel(SockRef, sendto, SendRef),
+                    {error, timeout}
+            end;
+
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+
+
+%% ---------------------------------------------------------------------------
+%%
+%% The only part of the msghdr() that *must* exist (a connected
+%% socket need not specify the addr field) is the iov.
+%% The ctrl field is optional, and the addr and flags are not
+%% used when sending.
+%%
+
+-spec sendmsg(Socket, MsgHdr) -> ok | {error, Reason} when
+      Socket  :: socket(),
+      MsgHdr  :: msghdr(),
+      Reason  :: term().
+
+sendmsg(Socket, MsgHdr) ->
+    sendmsg(Socket, MsgHdr,
+            ?SOCKET_SENDMSG_FLAGS_DEFAULT, ?SOCKET_SENDMSG_TIMEOUT_DEFAULT).
+
+
+-spec sendmsg(Socket, MsgHdr, Flags) -> ok | {error, Reason} when
+      Socket  :: socket(),
+      MsgHdr  :: msghdr(),
+      Flags   :: send_flags(),
+      Reason  :: term()
+                 ; (Socket, MsgHdr, Timeout :: nowait) -> ok |
+                                               {select, SelectInfo} |
+                                               {error, Reason} when
+      Socket     :: socket(),
+      MsgHdr     :: msghdr(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, MsgHdr, Timeout) -> ok | {error, Reason} when
+      Socket     :: socket(),
+      MsgHdr     :: msghdr(),
+      Timeout    :: timeout(),
+      Reason     :: term().
+
+sendmsg(Socket, MsgHdr, Flags) when is_list(Flags) ->
+    sendmsg(Socket, MsgHdr, Flags, ?SOCKET_SENDMSG_TIMEOUT_DEFAULT);
+sendmsg(Socket, MsgHdr, Timeout) 
+  when is_integer(Timeout) orelse (Timeout =:= infinity) ->
+    sendmsg(Socket, MsgHdr, ?SOCKET_SENDMSG_FLAGS_DEFAULT, Timeout).
+
+
+-spec sendmsg(Socket, MsgHdr, Flags, nowait) -> 
+                     ok |
+                     {ok, Remaining} |
+                     {select, SelectInfo} |
+                     {error, Reason} when
+      Socket     :: socket(),
+      MsgHdr     :: msghdr(),
+      Flags      :: send_flags(),
+      Remaining  :: erlang:iovec(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                   ; (Socket, MsgHdr, Flags, Timeout) -> 
+                     ok |
+                     {ok, Remaining} |
+                     {error, Reason} when
+      Socket     :: socket(),
+      MsgHdr     :: msghdr(),
+      Flags      :: send_flags(),
+      Timeout    :: timeout(),
+      Remaining  :: erlang:iovec(),
+      Reason     :: term().
+
+sendmsg(#socket{ref = SockRef}, #{iov := IOV} = MsgHdr, Flags, Timeout)
+  when is_list(IOV) andalso 
+       is_list(Flags) andalso
+       ((Timeout =:= nowait) orelse
+        (Timeout =:= infinity) orelse
+        (is_integer(Timeout) andalso (Timeout > 0))) ->
+    try ensure_msghdr(MsgHdr) of
+        M ->
+            EFlags = enc_send_flags(Flags),
+            do_sendmsg(SockRef, M, EFlags, Timeout)
+    catch
+        throw:T ->
+            T;
+        error:Reason ->
+            {error, Reason}
+    end.
+
+do_sendmsg(SockRef, MsgHdr, EFlags, Timeout) ->
+    TS      = timestamp(Timeout),
+    SendRef = make_ref(),
+    case nif_sendmsg(SockRef, SendRef, MsgHdr, EFlags) of
+        ok ->
+            %% We are done
+            ok;
+
+
+        {ok, Written} when is_integer(Written) andalso (Written > 0) ->
+            %% We should not retry here since the protocol may not
+            %% be able to handle a message being split. Leave it to
+            %% the caller to figure out (call again with the rest).
+            %%
+            %% We should really not need to cancel, since this is
+            %% accepted for sendmsg!
+            %%
+            cancel(SockRef, sendmsg, SendRef),
+            {ok, do_sendmsg_rest(maps:get(iov, MsgHdr), Written)};
+
+
+        {error, eagain} when (Timeout =:= nowait) ->
+            ?SELECT(sendmsg, SendRef);
+            
+
+        {error, eagain} ->
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, SendRef} ->
+                    do_sendmsg(SockRef, MsgHdr, EFlags, 
+                              next_timeout(TS, Timeout))
+
+            after Timeout ->
+                    cancel(SockRef, sendmsg, SendRef),
+                    {error, timeout}
+            end;
+
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+do_sendmsg_rest([B|IOVec], Written) when (Written >= size(B)) ->
+    do_sendmsg_rest(IOVec, Written - size(B));
+do_sendmsg_rest([B|IOVec], Written) ->
+    <<_:Written/binary, Rest/binary>> = B,
+    [Rest|IOVec].
+
+ensure_msghdr(#{ctrl := []} = M) ->
+    ensure_msghdr(maps:remove(ctrl, M));
+ensure_msghdr(#{iov := IOV, addr := Addr} = M) 
+  when is_list(IOV) andalso (IOV =/= []) ->
+    M#{iov => erlang:iolist_to_iovec(IOV), addr => ensure_sockaddr(Addr)};
+ensure_msghdr(#{iov := IOV} = M) 
+  when is_list(IOV) andalso (IOV =/= []) ->
+    M#{iov => erlang:iolist_to_iovec(IOV)};
+ensure_msghdr(_) ->
+    einval().
+
+
+
+
+%% ===========================================================================
+%%
+%% recv, recvfrom, recvmsg - receive a message from a socket
+%%
+%% Description:
+%% There is a special case for the argument Length. If its set to zero (0),
+%% it means "give me everything you have".
+%%
+%% Returns: {ok, Binary} | {error, Reason}
+%% Binary  - The received data as a binary
+%% Reason  - The error reason:
+%%              timeout | {timeout, AccData} |
+%%              posix() | {posix(), AccData} |
+%%              atom()  | {atom(), AccData}
+%% AccData - The data (as a binary) that we did manage to receive
+%%           before the timeout.
+%%
+%% Arguments:
+%% Socket  - The socket to read from.
+%% Length  - The number of bytes to read.
+%% Flags   - A list of "options" for the read.
+%% Timeout - Time-out in milliseconds.
+
+-spec recv(Socket) -> {ok, Data} | {error, Reason} when
+      Socket :: socket(),
+      Data   :: binary(),
+      Reason :: term().
+                          
+recv(Socket) ->
+    recv(Socket, 0).
+
+-spec recv(Socket, Length) -> {ok, Data} | {error, Reason} when
+      Socket :: socket(),
+      Length :: non_neg_integer(),
+      Data   :: binary(),
+      Reason :: term().
+
+recv(Socket, Length) ->
+    recv(Socket, Length,
+         ?SOCKET_RECV_FLAGS_DEFAULT,
+         ?SOCKET_RECV_TIMEOUT_DEFAULT).
+
+-spec recv(Socket, Length, Flags) -> {ok, Data} |
+                                     {error, Reason} when
+      Socket :: socket(),
+      Length :: non_neg_integer(),
+      Flags  :: recv_flags(),
+      Data   :: binary(),
+      Reason :: term()
+                ; (Socket, Length, Timeout :: nowait) -> {ok, Data} |
+                                              {select, SelectInfo} |
+                                              {ok, {Data, SelectInfo}} |
+                                              {error, Reason} when
+      Socket     :: socket(),
+      Length     :: non_neg_integer(),
+      Data       :: binary(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, Length, Timeout) -> {ok, Data} |
+                                                {error, Reason} when
+      Socket  :: socket(),
+      Length  :: non_neg_integer(),
+      Timeout :: timeout(),
+      Data    :: binary(),
+      Reason  :: term().
+
+recv(Socket, Length, Flags) when is_list(Flags) ->
+    recv(Socket, Length, Flags, ?SOCKET_RECV_TIMEOUT_DEFAULT);
+recv(Socket, Length, Timeout) ->
+    recv(Socket, Length, ?SOCKET_RECV_FLAGS_DEFAULT, Timeout).
+
+-spec recv(Socket, Length, Flags, nowait) -> {ok, Data} |
+                                             {select, SelectInfo} |
+                                             {ok, {Data, SelectInfo}} |
+                                             {error, Reason} when
+      Socket     :: socket(),
+      Length     :: non_neg_integer(),
+      Flags      :: recv_flags(),
+      Data       :: binary(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, Length, Flags, Timeout) -> {ok, Data} |
+                                                       {error, Reason} when
+      Socket     :: socket(),
+      Length     :: non_neg_integer(),
+      Flags      :: recv_flags(),
+      Timeout    :: timeout(),
+      Data       :: binary(),
+      Reason     :: term().
+
+recv(#socket{ref = SockRef}, Length, Flags, Timeout)
+  when (is_integer(Length) andalso (Length >= 0)) andalso
+       is_list(Flags) andalso
+       (is_integer(Timeout) orelse 
+        (Timeout =:= infinity) orelse 
+        (Timeout =:= nowait))  ->
+    EFlags = enc_recv_flags(Flags),
+    do_recv(SockRef, undefined, Length, EFlags, <<>>, Timeout).
+
+%% We need to pass the "old recv ref" around because of the special case
+%% with Length = 0. This case makes it neccessary to have a timeout function
+%% clause since we may never wait for anything (no receive select), and so the
+%% the only timeout check will be the function clause.
+%% Note that the Timeout value of 'nowait' has a special meaning. It means
+%% that we will either return with data or with the with {error, NNNN}. In
+%% wich case the caller will receive a select message at some later time.
+do_recv(SockRef, _OldRef, Length, EFlags, Acc, Timeout)
+  when (Timeout =:= nowait) orelse
+       (Timeout =:= infinity) orelse
+       (is_integer(Timeout) andalso (Timeout > 0)) ->
+    TS      = timestamp(Timeout),
+    RecvRef = make_ref(),
+    case nif_recv(SockRef, RecvRef, Length, EFlags) of
+        {ok, true = _Complete, Bin} when (size(Acc) =:= 0) ->
+            {ok, Bin};
+        {ok, true = _Complete, Bin} ->
+            {ok, <<Acc/binary, Bin/binary>>};
+
+        %% It depends on the amount of bytes we tried to read:
+        %%    0   - Read everything available
+        %%          We got something, but there may be more - keep reading.
+        %%    > 0 - We got a part of the message and we will be notified
+        %%          when there is more to read (a select message)
+        {ok, false = _Complete, Bin} when (Length =:= 0) ->
+            do_recv(SockRef, RecvRef,
+                    Length, EFlags,
+                    <<Acc/binary, Bin/binary>>,
+                    next_timeout(TS, Timeout));
+
+
+        %% Did not get all the user asked for, but the user also
+        %% specified 'nowait', so deliver what we got and the 
+        %% select info.
+        {ok, false = _Completed, Bin} when (Timeout =:= nowait) andalso 
+                                           (size(Acc) =:= 0) ->
+            {ok, {Bin, ?SELECT_INFO(recv, RecvRef)}};
+
+
+        {ok, false = _Completed, Bin} when (size(Acc) =:= 0) ->
+            %% We got the first chunk of it.
+            %% We will be notified (select message) when there
+            %% is more to read.
+	    NewTimeout = next_timeout(TS, Timeout),
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, RecvRef} ->
+                    do_recv(SockRef, RecvRef,
+                            Length-size(Bin), EFlags,
+                            Bin,
+                            next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {RecvRef, Reason}} ->
+                    {error, Reason}
+
+            after NewTimeout ->
+                    cancel(SockRef, recv, RecvRef),
+                    {error, {timeout, Acc}}
+            end;
+
+        {ok, false = _Completed, Bin} ->
+            %% We got a chunk of it!
+	    NewTimeout = next_timeout(TS, Timeout),
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, RecvRef} ->
+                    do_recv(SockRef, RecvRef,
+                            Length-size(Bin), EFlags,
+                            <<Acc/binary, Bin/binary>>,
+                            next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {RecvRef, Reason}} ->
+                    {error, Reason}
+
+            after NewTimeout ->
+                    cancel(SockRef, recv, RecvRef),
+                    {error, {timeout, Acc}}
+            end;
+
+
+        %% The user does not want to wait!
+        %% The user will be informed that there is something to read
+        %% via the select socket message (see below).
+
+        {error, eagain} when (Timeout =:= nowait) andalso (size(Acc) =:= 0) ->
+            ?SELECT(recv, RecvRef);
+        {error, eagain} when (Timeout =:= nowait) ->
+            {ok, {Acc, ?SELECT_INFO(recv, RecvRef)}};
+
+
+        %% We return with the accumulated binary (if its non-empty)
+        {error, eagain} when (Length =:= 0) andalso (size(Acc) > 0) ->
+            %% CAN WE REALLY DO THIS? THE NIF HAS SELECTED!! OR?
+            {ok, Acc};
+
+        {error, eagain} ->
+            %% There is nothing just now, but we will be notified when there
+            %% is something to read (a select message).
+            NewTimeout = next_timeout(TS, Timeout),
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, RecvRef} ->
+                    do_recv(SockRef, RecvRef,
+                            Length, EFlags,
+                            Acc,
+                            next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {RecvRef, Reason}} ->
+                    {error, Reason}
+
+            after NewTimeout ->
+                    cancel(SockRef, recv, RecvRef),
+                    {error, timeout}
+            end;
+
+        {error, closed = Reason} ->
+            do_close(SockRef),
+            if
+                (size(Acc) =:= 0) ->
+                    {error, Reason};
+                true ->
+                    {error, {Reason, Acc}}
+            end;
+
+        {error, _} = ERROR when (size(Acc) =:= 0) ->
+            ERROR;
+
+        {error, Reason} ->
+            {error, {Reason, Acc}}
+
+    end;
+
+do_recv(SockRef, RecvRef, 0 = _Length, _Eflags, Acc, _Timeout) ->
+    %% The current recv operation is to be cancelled, so no need for a ref...
+    %% The cancel will end our 'read everything you have' and "activate"
+    %% any waiting reader.
+    cancel(SockRef, recv, RecvRef),
+    {ok, Acc};
+do_recv(_SockRef, _RecvRef, _Length, _EFlags, Acc, _Timeout)
+  when (size(Acc) > 0) ->
+    {error, {timeout, Acc}};
+do_recv(_SockRef, _RecvRef, _Length, _EFlags, _Acc, _Timeout) ->
+    {error, timeout}.
+
+
+
+%% ---------------------------------------------------------------------------
+%%
+%% With recvfrom we get messages, which means that regardless of how
+%% much we want to read, we return when we get a message.
+%% The MaxSize argument basically defines the size of our receive
+%% buffer. By setting the size to zero (0), we use the configured
+%% size (see setopt).
+%% It may be impossible to know what (buffer) size is appropriate
+%% "in advance", and in those cases it may be convenient to use the
+%% (recv) 'peek' flag. When this flag is provided the message is *not*
+%% "consumed" from the underlying (OS) buffers, so another recvfrom call
+%% is needed, possibly with a then adjusted buffer size.
+%%
+
+-spec recvfrom(Socket) -> {ok, {Source, Data}} | {error, Reason} when
+      Socket    :: socket(),
+      Source    :: sockaddr() | undefined,
+      Data      :: binary(),
+      Reason    :: term().
+
+recvfrom(Socket) ->
+    recvfrom(Socket, 0).
+
+-spec recvfrom(Socket, BufSz) -> {ok, {Source, Data}} | {error, Reason} when
+      Socket    :: socket(),
+      BufSz     :: non_neg_integer(),
+      Source    :: sockaddr() | undefined,
+      Data      :: binary(),
+      Reason    :: term().
+
+recvfrom(Socket, BufSz) ->
+    recvfrom(Socket, BufSz,
+             ?SOCKET_RECV_FLAGS_DEFAULT,
+             ?SOCKET_RECV_TIMEOUT_DEFAULT).
+
+-spec recvfrom(Socket, Flags, nowait) -> 
+                      {ok, {Source, Data}} |
+                      {select, SelectInfo} |
+                      {error, Reason} when
+      Socket     :: socket(),
+      Flags      :: recv_flags(),
+      Source     :: sockaddr() | undefined,
+      Data       :: binary(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, Flags, Timeout) -> 
+                      {ok, {Source, Data}} |
+                      {error, Reason} when
+      Socket     :: socket(),
+      Flags      :: recv_flags(),
+      Timeout    :: timeout(),
+      Source     :: sockaddr() | undefined,
+      Data       :: binary(),
+      Reason     :: term()
+                 ; (Socket, BufSz, Flags) -> 
+                      {ok, {Source, Data}} | {error, Reason} when
+      Socket    :: socket(),
+      BufSz     :: non_neg_integer(),
+      Flags     :: recv_flags(),
+      Source    :: sockaddr() | undefined,
+      Data      :: binary(),
+      Reason    :: term()
+                ; (Socket, BufSz, nowait) -> 
+                      {ok, {Source, Data}} |
+                      {select, SelectInfo} |
+                      {error, Reason} when
+      Socket     :: socket(),
+      BufSz      :: non_neg_integer(),
+      Source     :: sockaddr() | undefined,
+      Data       :: binary(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, BufSz, Timeout) -> 
+                      {ok, {Source, Data}} | {error, Reason} when
+      Socket     :: socket(),
+      BufSz      :: non_neg_integer(),
+      Timeout    :: timeout(),
+      Source     :: sockaddr() | undefined,
+      Data       :: binary(),
+      Reason     :: term().
+
+recvfrom(Socket, Flags, Timeout) when is_list(Flags) ->
+    recvfrom(Socket, 0, Flags, Timeout);
+recvfrom(Socket, BufSz, Flags) when is_list(Flags) ->
+    recvfrom(Socket, BufSz, Flags, ?SOCKET_RECV_TIMEOUT_DEFAULT);
+recvfrom(Socket, BufSz, Timeout) ->
+    recvfrom(Socket, BufSz, ?SOCKET_RECV_FLAGS_DEFAULT, Timeout).
+
+-spec recvfrom(Socket, BufSz, Flags, nowait) -> 
+                      {ok, {Source, Data}} |
+                      {select, SelectInfo} |
+                      {error, Reason} when
+      Socket     :: socket(),
+      BufSz      :: non_neg_integer(),
+      Flags      :: recv_flags(),
+      Source     :: sockaddr() | undefined,
+      Data       :: binary(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, BufSz, Flags, Timeout) -> 
+                      {ok, {Source, Data}} |
+                      {error, Reason} when
+      Socket  :: socket(),
+      BufSz   :: non_neg_integer(),
+      Flags   :: recv_flags(),
+      Timeout :: timeout(),
+      Source  :: sockaddr() | undefined,
+      Data    :: binary(),
+      Reason  :: term().
+
+recvfrom(#socket{ref = SockRef}, BufSz, Flags, Timeout)
+  when (is_integer(BufSz) andalso (BufSz >= 0)) andalso
+       is_list(Flags) andalso
+       (is_integer(Timeout) orelse
+        (Timeout =:= infinity) orelse
+        (Timeout =:= nowait)) ->
+    EFlags = enc_recv_flags(Flags),
+    do_recvfrom(SockRef, BufSz, EFlags, Timeout).
+
+do_recvfrom(SockRef, BufSz, EFlags, Timeout)  ->
+    TS      = timestamp(Timeout),
+    RecvRef = make_ref(),
+    case nif_recvfrom(SockRef, RecvRef, BufSz, EFlags) of
+        {ok, {_Source, _NewData}} = OK ->
+            OK;
+
+
+        {error, eagain} when (Timeout =:= nowait) ->
+            ?SELECT(recvfrom, RecvRef);
+
+
+        {error, eagain} ->
+            %% There is nothing just now, but we will be notified when there
+            %% is something to read (a select message).
+            NewTimeout = next_timeout(TS, Timeout),
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, RecvRef} ->
+                    do_recvfrom(SockRef, BufSz, EFlags,
+                                next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {RecvRef, Reason}} ->
+                    {error, Reason}
+
+            after NewTimeout ->
+                    cancel(SockRef, recvfrom, RecvRef),
+                    {error, timeout}
+            end;
+
+        {error, _Reason} = ERROR ->
+            ERROR
+
+    end.
+
+
+%% ---------------------------------------------------------------------------
+%%
+
+-spec recvmsg(Socket) -> {ok, MsgHdr} | {error, Reason} when
+      Socket  :: socket(),
+      MsgHdr  :: msghdr(),
+      Reason  :: term().
+
+recvmsg(Socket) ->
+    recvmsg(Socket, 0, 0,
+            ?SOCKET_RECV_FLAGS_DEFAULT, ?SOCKET_RECV_TIMEOUT_DEFAULT).
+
+-spec recvmsg(Socket, Flags) -> {ok, MsgHdr} | {error, Reason} when
+      Socket  :: socket(),
+      Flags   :: recv_flags(),
+      MsgHdr  :: msghdr(),
+      Reason  :: term()
+                 ; (Socket, Timeout :: nowait) -> {ok, MsgHdr} |
+                                                  {select, SelectInfo} |
+                                                  {error, Reason} when
+      Socket     :: socket(),
+      MsgHdr     :: msghdr(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, Timeout) -> {ok, MsgHdr} | {error, Reason} when
+      Socket     :: socket(),
+      Timeout    :: timeout(),
+      MsgHdr     :: msghdr(),
+      Reason     :: term().
+
+recvmsg(Socket, Flags) when is_list(Flags) ->
+    recvmsg(Socket, 0, 0, Flags, ?SOCKET_RECV_TIMEOUT_DEFAULT);
+recvmsg(Socket, Timeout) ->
+    recvmsg(Socket, 0, 0, ?SOCKET_RECV_FLAGS_DEFAULT, Timeout).
+
+-spec recvmsg(Socket, Flags, nowait) -> {ok, MsgHdr} |
+                                        {select, SelectInfo} |
+                                        {error, Reason} when
+      Socket     :: socket(),
+      Flags      :: recv_flags(),
+      MsgHdr     :: msghdr(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, Flags, Timeout) -> {ok, MsgHdr} | {error, Reason} when
+      Socket     :: socket(),
+      Flags      :: recv_flags(),
+      Timeout    :: timeout(),
+      MsgHdr     :: msghdr(),
+      Reason     :: term()
+                 ; (Socket, BufSz, CtrlSz) -> {ok, MsgHdr} | {error, Reason} when
+      Socket     :: socket(),
+      BufSz      :: non_neg_integer(),
+      CtrlSz     :: non_neg_integer(),
+      MsgHdr     :: msghdr(),
+      Reason     :: term().
+
+recvmsg(Socket, Flags, Timeout) when is_list(Flags) ->
+    recvmsg(Socket, 0, 0, Flags, Timeout);
+recvmsg(Socket, BufSz, CtrlSz) when is_integer(BufSz) andalso is_integer(CtrlSz) ->
+    recvmsg(Socket, BufSz, CtrlSz,
+            ?SOCKET_RECV_FLAGS_DEFAULT, ?SOCKET_RECV_TIMEOUT_DEFAULT).
+
+
+-spec recvmsg(Socket, 
+              BufSz, CtrlSz,
+              Flags, nowait) -> {ok, MsgHdr} |
+                                {select, SelectInfo} |
+                                {error, Reason} when
+      Socket     :: socket(),
+      BufSz      :: non_neg_integer(),
+      CtrlSz     :: non_neg_integer(),
+      Flags      :: recv_flags(),
+      MsgHdr     :: msghdr(),
+      SelectInfo :: select_info(),
+      Reason     :: term()
+                 ; (Socket, 
+                    BufSz, CtrlSz,
+                    Flags, Timeout) -> {ok, MsgHdr} | {error, Reason} when
+      Socket     :: socket(),
+      BufSz      :: non_neg_integer(),
+      CtrlSz     :: non_neg_integer(),
+      Flags      :: recv_flags(),
+      Timeout    :: timeout(),
+      MsgHdr     :: msghdr(),
+      Reason     :: term().
+
+recvmsg(#socket{ref = SockRef}, BufSz, CtrlSz, Flags, Timeout)
+  when (is_integer(BufSz) andalso (BufSz >= 0)) andalso
+       (is_integer(CtrlSz) andalso (CtrlSz >= 0)) andalso
+       is_list(Flags) andalso
+       (is_integer(Timeout) orelse
+        (Timeout =:= infinity) orelse
+        (Timeout =:= nowait)) ->
+    EFlags = enc_recv_flags(Flags),
+    do_recvmsg(SockRef, BufSz, CtrlSz, EFlags, Timeout).
+
+do_recvmsg(SockRef, BufSz, CtrlSz, EFlags, Timeout)  ->
+    TS      = timestamp(Timeout),
+    RecvRef = make_ref(),
+    case nif_recvmsg(SockRef, RecvRef, BufSz, CtrlSz, EFlags) of
+        {ok, _MsgHdr} = OK ->
+            OK;
+
+
+        {error, eagain} when (Timeout =:= nowait) ->
+            ?SELECT(recvmsg, RecvRef);
+
+
+        {error, eagain} ->
+            %% There is nothing just now, but we will be notified when there
+            %% is something to read (a select message).
+            NewTimeout = next_timeout(TS, Timeout),
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, select, RecvRef} ->
+                    do_recvmsg(SockRef, BufSz, CtrlSz, EFlags,
+                               next_timeout(TS, Timeout));
+
+                {?SOCKET_TAG, _Socket, abort, {RecvRef, Reason}} ->
+                    {error, Reason}
+
+            after NewTimeout ->
+                    cancel(SockRef, recvmsg, RecvRef),
+                    {error, timeout}
+            end;
+
+        {error, closed} = ERROR ->
+            do_close(SockRef),
+            ERROR;
+
+        {error, _Reason} = ERROR ->
+            ERROR
+
+    end.
+
+
+
+
+%% ===========================================================================
+%%
+%% close - close a file descriptor
+%%
+%% Closing a socket is a two stage rocket (because of linger).
+%% We need to perform the actual socket close while in BLOCKING mode.
+%% But that would hang the entire VM, so what we do is divide the 
+%% close in two steps: 
+%% 1) nif_close + the socket_stop (nif) callback function
+%%    This is for everything that can be done safely NON-BLOCKING.
+%% 2) nif_finalize_close which is executed by a *dirty* scheduler
+%%    Before we call the socket close function, we set the socket 
+%%    BLOCKING. Thereby linger is handled properly.
+
+-spec close(Socket) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Reason :: term().
+
+close(#socket{ref = SockRef}) ->
+    do_close(SockRef).
+
+do_close(SockRef) ->
+    case nif_close(SockRef) of
+        ok ->
+            nif_finalize_close(SockRef);
+        {ok, CloseRef} ->
+            %% We must wait for the socket_stop callback function to 
+            %% complete its work
+            receive
+                {?SOCKET_TAG, #socket{ref = SockRef}, close, CloseRef} ->
+                    nif_finalize_close(SockRef)
+            end;
+        {error, _} = ERROR ->
+            ERROR
+    end.
+
+
+
+
+%% ===========================================================================
+%%
+%% shutdown - shut down part of a full-duplex connection
+%%
+
+-spec shutdown(Socket, How) -> ok | {error, Reason} when
+      Socket :: socket(),
+      How    :: shutdown_how(),
+      Reason :: term().
+
+shutdown(#socket{ref = SockRef}, How) ->
+    try
+        begin
+            EHow = enc_shutdown_how(How),
+            nif_shutdown(SockRef, EHow)
+        end
+    catch
+        throw:T ->
+            T;
+        %% <WIN32-TEMPORARY>
+        error:notsup:S ->
+            erlang:raise(error, notsup, S);
+        %% </WIN32-TEMPORARY>
+        error:Reason ->
+            {error, Reason}
+    end.
+
+
+
+
+%% ===========================================================================
+%%
+%% setopt - manipulate individual properties of a socket
+%%
+%% What properties are valid depend on what kind of socket it is
+%% (domain, type and protocol)
+%% If its an "invalid" option (or value), we should not crash but return some
+%% useful error...
+%%
+%% <KOLLA>
+%%
+%% WE NEED TO MAKE SURE THAT THE USER DOES NOT MAKE US BLOCKING
+%% AS MUCH OF THE CODE EXPECTS TO BE NON-BLOCKING!!
+%%
+%% </KOLLA>
+
+-spec setopt(Socket, otp, otp_socket_option(), Value) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, socket, socket_option(), Value) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, ip, ip_socket_option(), Value) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, ipv6, ipv6_socket_option(), Value) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, tcp, tcp_socket_option(), Value) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, udp, udp_socket_option(), Value) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, sctp, sctp_socket_option(), Value) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, Level, Key, Value) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Level  :: non_neg_integer(),
+      Key    :: non_neg_integer(),
+      Value  :: binary(),
+      Reason :: term().
+
+setopt(#socket{ref = SockRef}, Level, Key, Value) ->
+    try
+        begin
+            Domain               = which_domain(SockRef),
+            Type                 = which_type(SockRef),
+            Protocol             = which_protocol(SockRef),
+            {EIsEncoded, ELevel} = enc_setopt_level(Level),
+            EKey = enc_setopt_key(Level, Key, Domain, Type, Protocol),
+            EVal = enc_setopt_value(Level, Key, Value, Domain, Type, Protocol),
+            nif_setopt(SockRef, EIsEncoded, ELevel, EKey, EVal)
+        end
+    catch
+        throw:T ->
+            T;
+        %% <WIN32-TEMPORARY>
+        error:notsup:S ->
+            erlang:raise(error, notsup, S);
+        %% </WIN32-TEMPORARY>
+        error:Reason ->
+            {error, Reason} % Process more?
+    end.
+
+
+
+
+%% ===========================================================================
+%%
+%% getopt - retrieve individual properties of a socket
+%%
+%% What properties are valid depend on what kind of socket it is
+%% (domain, type and protocol).
+%% If its an "invalid" option, we should not crash but return some
+%% useful error...
+%%
+%% When specifying level as an integer, and therefor using "native mode",
+%% we should make it possible to specify common types instead of the
+%% value size. Example: int | bool | {string, pos_integer()} | non_neg_integer()
+%%
+
+-spec getopt(Socket, otp, otp_socket_option()) -> {ok, Value} | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, socket, socket_option()) -> {ok, Value} | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, ip, ip_socket_option()) -> {ok, Value} | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, ipv6, ipv6_socket_option()) -> {ok, Value} | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, tcp, tcp_socket_option()) -> {ok, Value} | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, udp, udp_socket_option()) -> {ok, Value} | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, sctp, sctp_socket_option()) -> {ok, Value} | {error, Reason} when
+      Socket :: socket(),
+      Value  :: term(),
+      Reason :: term()
+                ; (Socket, Level, Key) -> ok | {ok, Value} | {error, Reason} when
+      Socket    :: socket(),
+      Level     :: integer(),
+      Key       :: {NativeOpt, ValueSize},
+      NativeOpt :: integer(),
+      ValueSize :: int | bool | non_neg_integer(),
+      Value     :: term(),
+      Reason    :: term().
+
+getopt(#socket{ref = SockRef}, Level, Key) ->
+    try
+        begin
+            Domain   = which_domain(SockRef),
+            Type     = which_type(SockRef),
+            Protocol = which_protocol(SockRef),
+            {EIsEncoded, ELevel} = enc_getopt_level(Level),
+            EKey     = enc_getopt_key(Level, Key, Domain, Type, Protocol),
+            %% We may need to decode the value (for the same reason
+            %% we (may have) needed to encode the value for setopt).
+            case nif_getopt(SockRef, EIsEncoded, ELevel, EKey) of
+                ok ->
+                    ok;
+                {ok, EVal} ->
+                    Val = dec_getopt_value(Level, Key, EVal,
+                                           Domain, Type, Protocol),
+                    {ok, Val};
+                {error, _} = ERROR ->
+                    ERROR
+            end
+        end
+    catch
+        throw:E:_S ->
+            E;
+        %% <WIN32-TEMPORARY>
+        error:notsup:S ->
+            erlang:raise(error, notsup, S);
+        %% </WIN32-TEMPORARY>
+        error:Reason:_Stack ->
+            {error, Reason} % Process more?
+    end.
+
+
+%% These are internal "shortcut" functions for the options
+%% domain, type and protocol.
+
+-spec which_domain(SockRef) -> Domain when
+      SockRef :: reference(),
+      Domain  :: domain().
+
+which_domain(SockRef) ->
+    case nif_getopt(SockRef, true,
+                    ?SOCKET_OPT_LEVEL_OTP, ?SOCKET_OPT_OTP_DOMAIN) of
+        {ok, Domain} ->
+            Domain;
+        {error, _} = ERROR ->
+            throw(ERROR)
+    end.
+        
+
+-spec which_type(SockRef) -> Type when
+      SockRef :: reference(),
+      Type    :: type().
+
+which_type(SockRef) ->
+    case nif_getopt(SockRef, true,
+                    ?SOCKET_OPT_LEVEL_OTP, ?SOCKET_OPT_OTP_TYPE) of
+        {ok, Type} ->
+            Type;
+        {error, _} = ERROR ->
+            throw(ERROR)
+    end.
+
+-spec which_protocol(SockRef) -> Protocol when
+      SockRef  :: reference(),
+      Protocol :: protocol().
+
+which_protocol(SockRef) ->
+    case nif_getopt(SockRef, true,
+                    ?SOCKET_OPT_LEVEL_OTP, ?SOCKET_OPT_OTP_PROTOCOL) of
+        {ok, Proto} ->
+            Proto;
+        {error, _} = ERROR ->
+            throw(ERROR)
+    end.
+
+
+
+
+%% ===========================================================================
+%%
+%% sockname - return the current address of the socket.
+%%
+%%
+
+-spec sockname(Socket) -> {ok, SockAddr} | {error, Reason} when
+      Socket   :: socket(),
+      SockAddr :: sockaddr(),
+      Reason   :: term().
+
+sockname(#socket{ref = SockRef}) ->
+    nif_sockname(SockRef).
+
+
+
+%% ===========================================================================
+%%
+%% peername - return the address of the peer *connected* to the socket.
+%%
+%%
+
+-spec peername(Socket) -> {ok, SockAddr} | {error, Reason} when
+      Socket   :: socket(),
+      SockAddr :: sockaddr(),
+      Reason   :: term().
+
+peername(#socket{ref = SockRef}) ->
+    nif_peername(SockRef).
+
+
+%% ===========================================================================
+%%
+%% cancel - cancel an operation resulting in a select
+%%
+%% A call to accept, recv/recvfrom/recvmsg and send/sendto/sendmsg
+%% can result in a select if they are called with the Timeout argument
+%% set to nowait. This is indicated by the return of the select-info.
+%% Such a operation can be cancelled by calling this function.
+%%
+
+-spec cancel(Socket, SelectInfo) -> ok | {error, Reason} when
+      Socket     :: socket(),
+      SelectInfo :: select_info(),
+      Reason     :: term().
+
+cancel(#socket{ref = SockRef}, ?SELECT_INFO(Tag, Ref)) ->
+    cancel(SockRef, Tag, Ref).
+
+
+
+%% ===========================================================================
+%%
+%% Encode / decode
+%%
+%% ===========================================================================
+
+%% -spec enc_domain(Domain) -> non_neg_integer() when
+%%       Domain :: domain().
+
+enc_domain(local)  -> ?SOCKET_DOMAIN_LOCAL;
+enc_domain(inet)   -> ?SOCKET_DOMAIN_INET;
+enc_domain(inet6)  -> ?SOCKET_DOMAIN_INET6;
+enc_domain(Domain) -> invalid_domain(Domain).
+
+%% -spec enc_type(Domain, Type) -> non_neg_integer() when
+%%       Domain :: domain(),
+%%       Type   :: type().
+
+%% What combos are valid?
+enc_type(_, stream)    -> ?SOCKET_TYPE_STREAM;
+enc_type(_, dgram)     -> ?SOCKET_TYPE_DGRAM;
+enc_type(_, raw)       -> ?SOCKET_TYPE_RAW;
+enc_type(_, seqpacket) -> ?SOCKET_TYPE_SEQPACKET;
+enc_type(_, Type)      -> invalid_type(Type).
+
+-spec enc_protocol(Type, Protocol) -> non_neg_integer() | 
+                                      {raw, non_neg_integer()} when
+      Type     :: type(),
+      Protocol :: protocol().
+
+enc_protocol(_,         default) -> ?SOCKET_PROTOCOL_DEFAULT;
+enc_protocol(dgram,     ip)      -> ?SOCKET_PROTOCOL_IP;
+enc_protocol(stream,    tcp)     -> ?SOCKET_PROTOCOL_TCP;
+enc_protocol(dgram,     udp)     -> ?SOCKET_PROTOCOL_UDP;
+enc_protocol(seqpacket, sctp)    -> ?SOCKET_PROTOCOL_SCTP;
+enc_protocol(raw,       icmp)    -> ?SOCKET_PROTOCOL_ICMP;
+enc_protocol(raw,       igmp)    -> ?SOCKET_PROTOCOL_IGMP;
+enc_protocol(raw,       {raw, P} = RAW) when is_integer(P) -> RAW;
+enc_protocol(Type, Proto) -> 
+    invalid_protocol(Type, Proto).
+
+
+-spec enc_send_flags(Flags) -> non_neg_integer() when
+      Flags :: send_flags().
+
+enc_send_flags(Flags) ->
+    EFlags = [{confirm,   ?SOCKET_SEND_FLAG_CONFIRM},
+              {dontroute, ?SOCKET_SEND_FLAG_DONTROUTE},
+              {eor,       ?SOCKET_SEND_FLAG_EOR},
+              {more,      ?SOCKET_SEND_FLAG_MORE},
+              {nosignal,  ?SOCKET_SEND_FLAG_NOSIGNAL},
+              {oob,       ?SOCKET_SEND_FLAG_OOB}],
+    enc_flags(Flags, EFlags).
+
+-spec enc_recv_flags(Flags) -> non_neg_integer() when
+      Flags :: recv_flags().
+
+enc_recv_flags(Flags) ->
+    EFlags = [{cmsg_cloexec, ?SOCKET_RECV_FLAG_CMSG_CLOEXEC},
+              {errqueue,     ?SOCKET_RECV_FLAG_ERRQUEUE},
+              {oob,          ?SOCKET_RECV_FLAG_OOB},
+              {peek,         ?SOCKET_RECV_FLAG_PEEK},
+              {trunc,        ?SOCKET_RECV_FLAG_TRUNC}],
+    enc_flags(Flags, EFlags).
+
+
+enc_flags([], _) ->
+    0;
+enc_flags(Flags, EFlags) ->
+    F = fun(Flag, Acc) ->
+                case lists:keysearch(Flag, 1, EFlags) of
+                    {value, {Flag, EFlag}} ->
+                        Acc bor (1 bsl EFlag);
+                    false ->
+                        throw({error, {unknown_flag, Flag}})
+                end
+        end,
+    lists:foldl(F, 0, Flags).
+
+
+%% +++ Encode setopt level +++
+
+-spec enc_setopt_level(Level) -> {IsEncoded, EncodedLevel} when
+      Level        :: sockopt_level(),
+      IsEncoded    :: boolean(),
+      EncodedLevel :: integer().
+
+enc_setopt_level(otp) ->
+    {true, ?SOCKET_OPT_LEVEL_OTP};
+enc_setopt_level(socket) ->
+    {true, ?SOCKET_OPT_LEVEL_SOCKET};
+enc_setopt_level(ip) ->
+    {true, ?SOCKET_OPT_LEVEL_IP};
+enc_setopt_level(ipv6) ->
+    {true, ?SOCKET_OPT_LEVEL_IPV6};
+enc_setopt_level(tcp) ->
+    {true, ?SOCKET_OPT_LEVEL_TCP};
+enc_setopt_level(udp) ->
+    {true, ?SOCKET_OPT_LEVEL_UDP};
+enc_setopt_level(sctp) ->
+    {true, ?SOCKET_OPT_LEVEL_SCTP};
+%% Any option that is of an plain level must be provided as a binary
+%% already fully encoded!
+enc_setopt_level(L) when is_integer(L) ->
+    {false, L}.
+
+
+%% +++ Encode setopt key +++
+
+%% We should ...really... do something with the domain, type and protocol args...
+%% Also, any option (key) which has an integer level (plain) must also be provided
+%% in a plain mode, that is, as an integer.
+%% Also, not all options are available on all platforms. That is something we
+%% don't check here, but in the nif-code.
+
+enc_setopt_key(Level, Opt, Domain, Type, Protocol) ->
+    enc_sockopt_key(Level, Opt, set, Domain, Type, Protocol).
+
+
+%% +++ Encode setopt value +++
+%%
+%% For the most part this function does *not* do an actual encode,
+%% it simply validates the value type. But in some cases it will
+%% encode the value into an more "manageable" type.
+%% It also handles "aliases" (see linger).
+
+-dialyzer({nowarn_function, enc_setopt_value/6}).
+-spec enc_setopt_value(otp, otp_socket_option(),
+                       Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+                  ; (socket, socket_option(),
+                     Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (ip, ip_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (ipv6, ipv6_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (tcp, tcp_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (udp, udp_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (sctp, sctp_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (Level, Opt,
+              Value, Domain, Type, Protocol) -> term() when
+      Level    :: integer(),
+      Opt      :: integer(),
+      Value    :: binary(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol().
+      
+enc_setopt_value(otp, debug, V, _, _, _) when is_boolean(V) ->
+    V;
+enc_setopt_value(otp, iow, V, _, _, _) when is_boolean(V) ->
+    V;
+enc_setopt_value(otp, controlling_process, V, _, _, _) when is_pid(V) ->
+    V;
+enc_setopt_value(otp, rcvbuf, V, _, _, _) when (V =:= default) ->
+    0; % This will cause the nif-code to choose the default value
+enc_setopt_value(otp, rcvbuf, V, _, _, _) when is_integer(V) andalso (V > 0) ->
+    V;
+%% N: Number of reads (when specifying length = 0)
+%% V: Size of the "read" buffer
+enc_setopt_value(otp, rcvbuf, {N, BufSz} = V, _, stream = _T, _P) 
+  when (is_integer(N) andalso (N > 0)) andalso 
+       (is_integer(BufSz) andalso (BufSz > 0)) ->
+    V;
+enc_setopt_value(otp, rcvctrlbuf, V, _, _, _) when (V =:= default) ->
+    0;
+enc_setopt_value(otp, rcvctrlbuf, V, _, _, _) when is_integer(V) andalso (V > 0) ->
+    V;
+enc_setopt_value(otp, sndctrlbuf, V, _, _, _) when (V =:= default) ->
+    0;
+enc_setopt_value(otp, sndctrlbuf, V, _, _, _) when is_integer(V) andalso (V > 0) ->
+    V;
+enc_setopt_value(otp = L, Opt, V, _D, _T, _P) ->
+    not_supported({L, Opt, V});
+
+enc_setopt_value(socket, bindtodevice, V, _D, _T, _P) when is_list(V) ->
+    V;
+enc_setopt_value(socket, broadcast, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(socket, debug, V, _D, _T, _P) when is_integer(V) ->
+    V;
+enc_setopt_value(socket, dontroute, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(socket, keepalive, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(socket, linger, abort, D, T, P) ->
+    enc_setopt_value(socket, linger, {true, 0}, D, T, P);
+enc_setopt_value(socket, linger, {OnOff, Secs} = V, _D, _T, _P)
+  when is_boolean(OnOff) andalso is_integer(Secs) andalso (Secs >= 0) ->
+    V;
+enc_setopt_value(socket, oobinline, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(socket, peek_off, V, _D, _T, _P) when is_integer(V) ->
+    V;
+enc_setopt_value(socket, priority, V, _D, _T, _P) when is_integer(V) ->
+    V;
+enc_setopt_value(socket, rcvbuf, V, _D, _T, _P) when is_integer(V) ->
+    V;
+enc_setopt_value(socket, rcvlowat, V, _D, _T, _P) when is_integer(V) ->
+    V;
+enc_setopt_value(socket, rcvtimeo, #{sec := Sec, usec := USec} = V, _D, _T, _P) 
+  when is_integer(Sec) andalso is_integer(USec) ->
+    V;
+enc_setopt_value(socket, reuseaddr, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(socket, reuseport, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(socket, sndbuf, V, _D, _T, _P) when is_integer(V) ->
+    V;
+enc_setopt_value(socket, sndlowat, V, _D, _T, _P) when is_integer(V) ->
+    V;
+enc_setopt_value(socket, sndtimeo, #{sec := Sec, usec := USec} = V, _D, _T, _P) 
+  when is_integer(Sec) andalso is_integer(USec) ->
+    V;
+enc_setopt_value(socket, timestamp, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(socket = L, Opt, V, _D, _T, _P) ->
+    not_supported({L, Opt, V});
+
+enc_setopt_value(ip, add_membership, #{multiaddr := MA,
+                                       interface := IF} = V, _D, _T, _P)
+  when (is_tuple(MA) andalso (size(MA) =:= 4)) andalso
+       ((IF =:= any) orelse (is_tuple(IF) andalso (size(IF) =:= 4))) ->
+    V;
+enc_setopt_value(ip, add_source_membership, #{multiaddr  := MA,
+                                              interface  := IF,
+                                              sourceaddr := SA} = V, _D, _T, _P)
+  when (is_tuple(MA) andalso (size(MA) =:= 4)) andalso
+       (is_tuple(IF) andalso (size(IF) =:= 4)) andalso
+       (is_tuple(SA) andalso (size(SA) =:= 4)) ->
+    V;
+enc_setopt_value(ip, block_source, #{multiaddr  := MA,
+                                     interface  := IF,
+                                     sourceaddr := SA} = V, _D, _T, _P)
+  when (is_tuple(MA) andalso (size(MA) =:= 4)) andalso
+       (is_tuple(IF) andalso (size(IF) =:= 4)) andalso
+       (is_tuple(SA) andalso (size(SA) =:= 4)) ->
+    V;
+enc_setopt_value(ip, drop_membership, #{multiaddr := MA,
+                                        interface := IF} = V, _D, _T, _P)
+  when (is_tuple(MA) andalso (size(MA) =:= 4)) andalso
+       ((IF =:= any) orelse (is_tuple(IF) andalso (size(IF) =:= 4))) ->
+    V;
+enc_setopt_value(ip, drop_source_membership, #{multiaddr  := MA,
+                                               interface  := IF,
+                                               sourceaddr := SA} = V, _D, _T, _P)
+  when (is_tuple(MA) andalso (size(MA) =:= 4)) andalso
+       (is_tuple(IF) andalso (size(IF) =:= 4)) andalso
+       (is_tuple(SA) andalso (size(SA) =:= 4)) ->
+    V;
+enc_setopt_value(ip, freebind, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, hdrincl, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, minttl, V, _D, _T, _P) when is_integer(V) ->
+    V;
+enc_setopt_value(ip, msfilter, null = V, _D, _T, _P) ->
+    V;
+enc_setopt_value(ip, msfilter, #{multiaddr := MA,
+                                 interface := IF,
+                                 fmode     := FMode,
+                                 slist     := SL} = V, _D, _T, _P) 
+  when (is_tuple(MA) andalso (size(MA) =:= 4)) andalso
+       (is_tuple(IF) andalso (size(IF) =:= 4)) andalso
+       ((FMode =:= include) orelse (FMode =:= exclude)) andalso 
+       is_list(SL) ->
+    ensure_ip_msfilter_slist(SL),
+    V;
+enc_setopt_value(ip, mtu_discover, V, _D, _T, _P)
+  when (V =:= want)  orelse
+       (V =:= dont)  orelse
+       (V =:= do)    orelse
+       (V =:= probe) orelse
+       is_integer(V) ->
+    V;
+enc_setopt_value(ip, multicast_all, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, multicast_if, V, _D, _T, _P)
+  when (V =:= any) orelse (is_tuple(V) andalso (size(V) =:= 4)) ->
+    V;
+enc_setopt_value(ip, multicast_loop, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, multicast_ttl, V, _D, _T, _P)
+  when is_integer(V) andalso (0 =< V) andalso (V =< 255) ->
+    V;
+enc_setopt_value(ip, nodefrag, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, pktinfo, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, recvdstaddr, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, recverr, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, recvif, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, recvopts, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, recvorigdstaddr, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, recvtos, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, recvttl, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, retopts, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, router_alert, V, _D, _T, _P)
+  when is_integer(V) ->
+    V;
+enc_setopt_value(ip, sendsrcaddr, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, tos, V, _D, _T, _P)
+  when (V =:= lowdelay)    orelse
+       (V =:= throughput)  orelse
+       (V =:= reliability) orelse
+       (V =:= mincost)     orelse
+       is_integer(V) ->
+    V;
+enc_setopt_value(ip, transparent, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ip, ttl, V, _D, _T, _P)
+  when is_integer(V) ->
+    V;
+enc_setopt_value(ip, unblock_source, #{multiaddr  := MA,
+                                       interface  := IF,
+                                       sourceaddr := SA} = V, _D, _T, _P)
+  when (is_tuple(MA) andalso (size(MA) =:= 4)) andalso
+       (is_tuple(IF) andalso (size(IF) =:= 4)) andalso
+       (is_tuple(SA) andalso (size(SA) =:= 4)) ->
+    V;
+enc_setopt_value(ip = L, Opt, V, _D, _T, _P) ->
+    not_supported({L, Opt, V});
+
+enc_setopt_value(ipv6, addrform, inet = V, _D, _T, _P) ->
+    enc_domain(V);
+enc_setopt_value(ipv6, add_membership, #{multiaddr := MA,
+                                         interface := IF} = V, _D, _T, _P)
+  when ((is_tuple(MA) andalso (size(MA) =:= 8)) andalso
+        (is_integer(IF) andalso (IF >= 0))) ->
+    V;
+%% Is this obsolete? When get, the result is enoprotoopt and in the 
+%% header file it says 'obsolete'...
+%% But there might be (old?) versions of linux where it still works...
+enc_setopt_value(ipv6, authhdr, V, _D, T, _P)
+  when is_boolean(V) andalso ((T =:= dgram) orelse (T =:= raw)) ->
+    V;
+enc_setopt_value(ipv6, dstopts, V, _D, T, _P)
+  when is_boolean(V) andalso ((T =:= dgram) orelse (T =:= raw)) ->
+    V;
+enc_setopt_value(ipv6, drop_membership, #{multiaddr := MA,
+                                          interface := IF} = V, _D, _T, _P)
+  when ((is_tuple(MA) andalso (size(MA) =:= 8)) andalso
+        (is_integer(IF) andalso (IF >= 0))) ->
+    V;
+enc_setopt_value(ipv6, flowinfo, V, _D, T, _P)
+  when is_boolean(V) andalso ((T =:= dgram) orelse (T =:= raw)) ->
+    V;
+enc_setopt_value(ipv6, hoplimit, V, _D, T, _P)
+  when is_boolean(V) andalso ((T =:= dgram) orelse (T =:= raw)) ->
+    V;
+enc_setopt_value(ipv6, hopopts, V, _D, T, _P)
+  when is_boolean(V) andalso ((T =:= dgram) orelse (T =:= raw)) ->
+    V;
+enc_setopt_value(ipv6, mtu, V, _D, _T, _P) when is_integer(V) ->
+    V;
+enc_setopt_value(ipv6, mtu_discover, V, _D, _T, _P)
+  when (V =:= want)  orelse
+       (V =:= dont)  orelse
+       (V =:= do)    orelse
+       (V =:= probe) orelse
+       is_integer(V) ->
+    V;
+enc_setopt_value(ipv6, multicast_hops, V, _D, _T, _P)
+  when (V =:= default) ->
+    -1;
+enc_setopt_value(ipv6, multicast_hops, V, _D, _T, _P)
+  when is_integer(V) andalso (V >= 0) andalso (V =< 255) ->
+    V;
+enc_setopt_value(ipv6, multicast_if, V, _D, _T, _P)
+  when is_integer(V) ->
+    V;
+enc_setopt_value(ipv6, multicast_loop, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ipv6, recverr, V, _D, _T, _P)
+  when is_boolean(V) ->
+    V;
+enc_setopt_value(ipv6, Opt, V, _D, _T, _P)
+  when ((Opt =:= recvpktinfo) orelse (Opt =:= pktinfo)) andalso 
+       is_boolean(V) ->
+    V;
+enc_setopt_value(ipv6, router_alert, V, _D, T, _P)
+  when is_integer(V) andalso (T =:= raw) ->
+    V;
+enc_setopt_value(ipv6, rthdr, V, _D, T, _P)
+  when is_boolean(V) andalso ((T =:= dgram) orelse (T =:= raw)) ->
+    V;
+enc_setopt_value(ipv6, unicast_hops, V, _D, _T, _P)
+  when (V =:= default) ->
+    -1;
+enc_setopt_value(ipv6, unicast_hops, V, _D, _T, _P)
+  when is_integer(V) andalso (V >= 0) andalso (V =< 255) ->
+    V;
+enc_setopt_value(ipv6, v6only, V, _D, _T, _P) when is_boolean(V) ->
+    V;
+enc_setopt_value(ipv6 = L, Opt, V, _D, _T, _P) ->
+    not_supported({L, Opt, V});
+
+enc_setopt_value(tcp, congestion, V, _D, T, P)
+  when is_list(V) andalso
+       (T =:= stream) andalso
+       (P =:= tcp) ->
+    V;
+enc_setopt_value(tcp, maxseg, V, _D, T, P)
+  when is_integer(V) andalso
+       (T =:= stream) andalso
+       (P =:= tcp) ->
+    V;
+enc_setopt_value(tcp, nodelay, V, _D, T, P)
+  when is_boolean(V) andalso
+       (T =:= stream) andalso
+       (P =:= tcp) ->
+    V;
+enc_setopt_value(tcp = L, Opt, V, _D, _T, _P) ->
+    not_supported({L, Opt, V});
+
+enc_setopt_value(udp, cork, V, _D, T, P)
+  when is_boolean(V) andalso (T =:= dgram) andalso (P =:= udp) ->
+    V;
+enc_setopt_value(udp = L, Opt, _V, _D, _T, _P) ->
+    not_supported({L, Opt});
+
+enc_setopt_value(sctp, associnfo, #{assoc_id       := AssocId,
+                                    asocmaxrxt     := MaxRxt,
+                                    num_peer_dests := NumPeerDests,
+                                    peer_rwnd      := PeerRWND,
+                                    local_rwnd     := LocalRWND,
+                                    cookie_life    := CLife} = V,
+                 _D, _T, P)
+  when is_integer(AssocId) andalso
+       is_integer(MaxRxt)       andalso (MaxRxt >= 0)       andalso
+       is_integer(NumPeerDests) andalso (NumPeerDests >= 0) andalso
+       is_integer(PeerRWND)     andalso (PeerRWND >= 0)     andalso
+       is_integer(LocalRWND)    andalso (LocalRWND >= 0)    andalso
+       is_integer(CLife)        andalso (CLife >= 0)        andalso
+       (P =:= sctp) ->
+    V;
+enc_setopt_value(sctp, autoclose, V, _D, _T, P)
+  when is_integer(V) andalso (V >= 0) andalso (P =:= sctp) ->
+    V;
+enc_setopt_value(sctp, disable_fragments, V, _D, _T, P)
+  when is_boolean(V) andalso (P =:= sctp) ->
+    V;
+enc_setopt_value(sctp, events, #{data_in          := DataIn,
+                                 association      := Assoc,
+                                 address          := Addr,
+                                 send_failure     := SndFailure,
+                                 peer_error       := PeerError,
+                                 shutdown         := Shutdown,
+                                 partial_delivery := PartialDelivery,
+                                 adaptation_layer := AdaptLayer,
+                                 authentication   := Auth,
+                                 sender_dry       := SndDry} = V, _D, _T, P)
+  when is_boolean(DataIn)          andalso
+       is_boolean(Assoc)           andalso
+       is_boolean(Addr)            andalso
+       is_boolean(SndFailure)      andalso
+       is_boolean(PeerError)       andalso
+       is_boolean(Shutdown)        andalso
+       is_boolean(PartialDelivery) andalso
+       is_boolean(AdaptLayer)      andalso
+       is_boolean(Auth)            andalso
+       is_boolean(SndDry)          andalso
+       (P =:= sctp) ->
+    V;
+enc_setopt_value(sctp, initmsg, #{num_outstreams := NumOut,
+                                  max_instreams  := MaxIn,
+                                  max_attempts   := MaxAttempts,
+                                  max_init_timeo := MaxInitTO} = V,
+                 _D, _T, P)
+  when is_integer(NumOut)      andalso (NumOut >= 0)      andalso
+       is_integer(MaxIn)       andalso (MaxIn >= 0)       andalso
+       is_integer(MaxAttempts) andalso (MaxAttempts >= 0) andalso
+       is_integer(MaxInitTO)   andalso (MaxInitTO >= 0)   andalso
+       (P =:= sctp) ->
+    V;
+enc_setopt_value(sctp, maxseg, V, _D, _T, P)
+  when is_integer(V) andalso (V >= 0) andalso (P =:= sctp) ->
+    V;
+enc_setopt_value(sctp, nodelay, V, _D, _T, P)
+  when is_boolean(V) andalso (P =:= sctp) ->
+    V;
+enc_setopt_value(sctp, rtoinfo, #{assoc_id := AssocId,
+                                  initial  := Init,
+                                  max      := Max,
+                                  min      := Min} = V,
+                 _D, _T, P)
+  when is_integer(AssocId) andalso
+       is_integer(Init) andalso (Init >= 0) andalso
+       is_integer(Max)  andalso (Max >= 0)  andalso
+       is_integer(Min)  andalso (Min >= 0)  andalso
+       (P =:= sctp) ->
+    V;
+enc_setopt_value(sctp = L, Opt, V, _D, _T, _P) ->
+    not_supported({L, Opt, V});
+
+%% enc_setopt_value(raw = L, Opt, _V, _D, _T, _P) ->
+%%     not_supported({L, Opt});
+
+%% Is this correct? What about getopt?
+enc_setopt_value(L, Opt, V, _, _, _)
+  when is_integer(L) andalso is_integer(Opt) andalso is_binary(V) ->
+    V.
+
+
+
+
+%% +++ Encode getopt value +++
+
+enc_getopt_level(Level) ->
+    enc_setopt_level(Level).
+
+
+%% +++ Encode getopt key +++
+
+enc_getopt_key(Level, Opt, Domain, Type, Protocol) ->
+    enc_sockopt_key(Level, Opt, get, Domain, Type, Protocol).
+
+
+%% +++ Decode getopt value +++
+%%
+%% For the most part, we simply let the value pass through, but for some
+%% values we may need to do an actual decode.
+%%
+
+%% Let the user deal with this for now...
+dec_getopt_value(_L, _Opt, V, _D, _T, _P) ->
+    V.
+
+
+
+%% +++ Encode socket option key +++
+
+%% Most options are usable both for set and get, but some are
+%% are only available for e.g. get.
+-spec enc_sockopt_key(Level, Opt,
+                      Direction,
+                      Domain, Type, Protocol) -> non_neg_integer() when
+      Level     :: otp,
+      Direction :: set | get,
+      Opt       :: otp_socket_option(),
+      Domain    :: domain(),
+      Type      :: type(),
+      Protocol  :: protocol()
+                   ; (Level, Direction, Opt,
+                      Domain, Type, Protocol) -> non_neg_integer() when
+      Level     :: socket,
+      Direction :: set | get,
+      Opt       :: socket_option(),
+      Domain    :: domain(),
+      Type      :: type(),
+      Protocol  :: protocol()
+                   ; (Level, Direction, Opt,
+                      Domain, Type, Protocol) -> non_neg_integer() when
+      Level     :: ip,
+      Direction :: set | get,
+      Opt       :: ip_socket_option(),
+      Domain    :: domain(),
+      Type      :: type(),
+      Protocol  :: protocol()
+                   ; (Level, Direction, Opt,
+                      Domain, Type, Protocol) -> non_neg_integer() when
+      Level     :: ipv6,
+      Direction :: set | get,
+      Opt       :: ipv6_socket_option(),
+      Domain    :: domain(),
+      Type      :: type(),
+      Protocol  :: protocol()
+                   ; (Level, Direction, Opt,
+                      Domain, Type, Protocol) -> non_neg_integer() when
+      Level     :: tcp,
+      Direction :: set | get,
+      Opt       :: tcp_socket_option(),
+      Domain    :: domain(),
+      Type      :: type(),
+      Protocol  :: protocol()
+                   ; (Level, Direction, Opt,
+                      Domain, Type, Protocol) -> non_neg_integer() when
+      Level     :: udp,
+      Direction :: set | get,
+      Opt       :: udp_socket_option(),
+      Domain    :: domain(),
+      Type      :: type(),
+      Protocol  :: protocol()
+                   ; (Level, Direction, Opt,
+                      Domain, Type, Protocol) -> non_neg_integer() when
+      Level     :: sctp,
+      Direction :: set | get,
+      Opt       :: sctp_socket_option(),
+      Domain    :: domain(),
+      Type      :: type(),
+      Protocol  :: protocol()
+                   ; (Level, Direction, Opt,
+                      Domain, Type, Protocol) -> non_neg_integer() when
+      Level     :: integer(),
+      Direction :: set,
+      Opt       :: integer(),
+      Domain    :: domain(),
+      Type      :: type(),
+      Protocol  :: protocol()
+                   ; (Level, Direction, Opt,
+                      Domain, Type, Protocol) -> non_neg_integer() when
+      Level     :: integer(),
+      Direction :: get,
+      Opt       :: {NativeOpt, ValueSize},
+      NativeOpt :: integer(),
+      ValueSize :: non_neg_integer(),
+      Domain    :: domain(),
+      Type      :: type(),
+      Protocol  :: protocol().
+
+
+%% +++ OTP socket options +++
+enc_sockopt_key(otp, debug, _, _, _, _) ->
+    ?SOCKET_OPT_OTP_DEBUG;
+enc_sockopt_key(otp, iow, _, _, _, _) ->
+    ?SOCKET_OPT_OTP_IOW;
+enc_sockopt_key(otp, controlling_process, _, _, _, _) ->
+    ?SOCKET_OPT_OTP_CTRL_PROC;
+enc_sockopt_key(otp, rcvbuf, _, _, _, _) ->
+    ?SOCKET_OPT_OTP_RCVBUF;
+enc_sockopt_key(otp, rcvctrlbuf, _, _, _, _) ->
+    ?SOCKET_OPT_OTP_RCVCTRLBUF;
+enc_sockopt_key(otp, sndctrlbuf, _, _, _, _) ->
+    ?SOCKET_OPT_OTP_SNDCTRLBUF;
+enc_sockopt_key(otp, fd, get = _Dir, _, _, _) ->
+    ?SOCKET_OPT_OTP_FD;
+enc_sockopt_key(otp = L, Opt, _, _, _, _) ->
+    not_supported({L, Opt});
+
+%% +++ SOCKET socket options +++
+enc_sockopt_key(socket = _L, acceptconn = _Opt, get = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_ACCEPTCONN;
+enc_sockopt_key(socket = L, acceptconn = Opt, Dir, _D, _T, _P) ->
+    not_supported({L, Opt, Dir});
+enc_sockopt_key(socket = L, acceptfilter = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+%% Before linux 3.8, this socket option could be set but not get.
+%% Maximum size of buffer for name: IFNAMSIZ
+%% So, we let the implementation decide.
+enc_sockopt_key(socket = _L, bindtodevice = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_BINDTODEVICE;
+enc_sockopt_key(socket, broadcast = _Opt, _Dir, _D, dgram = _T, _P) ->
+    ?SOCKET_OPT_SOCK_BROADCAST;
+enc_sockopt_key(socket = L, busy_poll = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(socket = _L, debug = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_DEBUG;
+enc_sockopt_key(socket, domain = _Opt, get = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_DOMAIN;
+enc_sockopt_key(socket, dontroute = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_DONTROUTE;
+enc_sockopt_key(socket = L, error = Opt, get = _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+%% This is only for connection-oriented sockets, but who are those?
+%% Type = stream or Protocol = tcp?
+%% For now, we just let is pass and it will fail later if not ok...
+enc_sockopt_key(socket, keepalive = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_KEEPALIVE;
+enc_sockopt_key(socket, linger = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_LINGER;
+enc_sockopt_key(socket = L, mark = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(socket = _L, oobinline = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_OOBINLINE;
+enc_sockopt_key(socket = L, passcred = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(socket = _L, peek_off = _Opt, _Dir, local = _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_PEEK_OFF;
+enc_sockopt_key(socket = L, peekcred = Opt, get = _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(socket, priority = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_PRIORITY;
+enc_sockopt_key(socket, protocol = _Opt, get = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_PROTOCOL;
+enc_sockopt_key(socket, rcvbuf = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_RCVBUF;
+enc_sockopt_key(socket = L, rcvbufforce = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+%% May not work on linux.
+enc_sockopt_key(socket = _L, rcvlowat = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_RCVLOWAT;
+enc_sockopt_key(socket = _L, rcvtimeo = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_RCVTIMEO;
+enc_sockopt_key(socket = _L, reuseaddr = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_REUSEADDR;
+enc_sockopt_key(socket = _L, reuseport = _Opt, _Dir, D, _T, _P)
+  when ((D =:= inet) orelse (D =:= inet6)) ->
+    ?SOCKET_OPT_SOCK_REUSEPORT;
+enc_sockopt_key(socket = L, rxq_ovfl = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(socket = L, setfib = Opt, set = _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(socket = _L, sndbuf = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_SNDBUF;
+enc_sockopt_key(socket = L, sndbufforce = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+%% Not changeable on linux.
+enc_sockopt_key(socket = _L, sndlowat = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_SNDLOWAT;
+enc_sockopt_key(socket = _L, sndtimeo = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_SNDTIMEO;
+enc_sockopt_key(socket = _L, timestamp = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_TIMESTAMP;
+enc_sockopt_key(socket = _L, type = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SOCK_TYPE;
+enc_sockopt_key(socket = L, UnknownOpt, _Dir, _D, _T, _P) ->
+    unknown({L, UnknownOpt});
+
+%% +++ IP socket options +++
+enc_sockopt_key(ip = _L, add_membership = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_ADD_MEMBERSHIP;
+enc_sockopt_key(ip = _L, add_source_membership = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_ADD_SOURCE_MEMBERSHIP;
+enc_sockopt_key(ip = _L, block_source = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_BLOCK_SOURCE;
+%% FreeBSD only?
+%% Only respected on udp and raw ip (unless the hdrincl option has been set).
+enc_sockopt_key(ip = L, dontfrag = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ip = _L, drop_membership = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_DROP_MEMBERSHIP;
+enc_sockopt_key(ip = _L, drop_source_membership = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_DROP_SOURCE_MEMBERSHIP;
+%% Linux only?
+enc_sockopt_key(ip = _L, freebind = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_FREEBIND;
+enc_sockopt_key(ip = _L, hdrincl = _Opt, _Dir, _D, raw = _T, _P) ->
+    ?SOCKET_OPT_IP_HDRINCL;
+enc_sockopt_key(ip = _L, minttl = _Opt, _Dir, _D, raw = _T, _P) ->
+    ?SOCKET_OPT_IP_MINTTL;
+enc_sockopt_key(ip = _L, msfilter = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_MSFILTER;
+enc_sockopt_key(ip = _L, mtu = _Opt, get = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_MTU;
+enc_sockopt_key(ip = _L, mtu_discover = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_MTU_DISCOVER;
+enc_sockopt_key(ip = _L, multicast_all = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_MULTICAST_ALL;
+enc_sockopt_key(ip = _L, multicast_if = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_MULTICAST_IF;
+enc_sockopt_key(ip = _L, multicast_loop = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_MULTICAST_LOOP;
+enc_sockopt_key(ip = _L, multicast_ttl = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_MULTICAST_TTL;
+enc_sockopt_key(ip = _L, nodefrag = _Opt, _Dir, _D, raw = _T, _P) ->
+    ?SOCKET_OPT_IP_NODEFRAG;
+enc_sockopt_key(ip = L, options = Opt, _Dir, _D, _T, _P) ->
+    not_supported({Opt, L});
+enc_sockopt_key(ip = _L, pktinfo = _Opt, _Dir, _D, dgram = _T, _P) ->
+    ?SOCKET_OPT_IP_PKTINFO;
+enc_sockopt_key(ip = _L, recvdstaddr = _Opt, _Dir, _D, T, _P) when (T =:= dgram) ->
+    ?SOCKET_OPT_IP_RECVDSTADDR;
+enc_sockopt_key(ip = _L, recverr = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_RECVERR;
+enc_sockopt_key(ip = _L, recvif = _Opt, _Dir, _D, T, _P)
+  when (T =:= dgram) orelse (T =:= raw) ->
+    ?SOCKET_OPT_IP_RECVIF;
+enc_sockopt_key(ip = _L, recvopts = _Opt, _Dir, _D, T, _P) when (T =/= stream) ->
+    ?SOCKET_OPT_IP_RECVOPTS;
+enc_sockopt_key(ip = _L, recvorigdstaddr = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_RECVORIGDSTADDR;
+enc_sockopt_key(ip, recvtos = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_RECVTOS;
+enc_sockopt_key(ip = _L, recvttl = _Opt, _Dir, _D, T, _P) when (T =/= stream) ->
+    ?SOCKET_OPT_IP_RECVTTL;
+enc_sockopt_key(ip = _L, retopts = _Opt, _Dir, _D, T, _P) when (T =/= stream) ->
+    ?SOCKET_OPT_IP_RETOPTS;
+enc_sockopt_key(ip, router_alert = _Opt, _Dir, _D, raw = _T, _P) ->
+    ?SOCKET_OPT_IP_ROUTER_ALERT;
+enc_sockopt_key(ip, sendsrcaddr = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_SENDSRCADDR;
+%% On FreeBSD it specifies that this option is only valid
+%% for stream, dgram and "some" raw sockets...
+%% No such condition on linux (in the man page)...
+enc_sockopt_key(ip, tos = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_TOS;
+enc_sockopt_key(ip = _L, transparent = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_TRANSPARENT;
+enc_sockopt_key(ip, ttl = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_TTL;
+enc_sockopt_key(ip = _L, unblock_source = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IP_UNBLOCK_SOURCE;
+enc_sockopt_key(ip = L, UnknownOpt, _Dir, _D, _T, _P) ->
+    unknown({L, UnknownOpt});
+
+%% IPv6 socket options
+enc_sockopt_key(ipv6 = _L, addrform = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_ADDRFORM;
+enc_sockopt_key(ipv6, add_membership = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_ADD_MEMBERSHIP;
+enc_sockopt_key(ipv6 = _L, authhdr = _Opt, _Dir, _D, T, _P) 
+  when ((T =:= dgram) orelse (T =:= raw)) ->
+    ?SOCKET_OPT_IPV6_AUTHHDR;
+enc_sockopt_key(ipv6 = L, auth_level = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = L, checksum = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6, drop_membership = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_DROP_MEMBERSHIP;
+enc_sockopt_key(ipv6 = _L, dstopts = _Opt, _Dir, _D, T, _P)
+  when (T =:= dgram) orelse (T =:= raw) ->
+    ?SOCKET_OPT_IPV6_DSTOPTS;
+enc_sockopt_key(ipv6 = L, esp_trans_level = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = L, esp_network_level = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = _L, flowinfo = _Opt, _Dir, _D, T, _P)
+  when (T =:= dgram) orelse (T =:= raw) ->
+    ?SOCKET_OPT_IPV6_DSTOPTS;
+enc_sockopt_key(ipv6, hoplimit = _Opt, _Dir, _D, T, _P)
+  when (T =:= dgram) orelse (T =:= raw) ->
+    ?SOCKET_OPT_IPV6_HOPLIMIT;
+enc_sockopt_key(ipv6 = _L, hopopts = _Opt, _Dir, _D, T, _P) 
+  when ((T =:= dgram) orelse (T =:= raw)) ->
+    ?SOCKET_OPT_IPV6_HOPOPTS;
+enc_sockopt_key(ipv6 = L, ipcomp_level = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = L, join_group = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = L, leave_group = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = _L, mtu = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_MTU;
+enc_sockopt_key(ipv6 = _L, mtu_discover = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_MTU_DISCOVER;
+enc_sockopt_key(ipv6 = _L, multicast_hops = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_MULTICAST_HOPS;
+enc_sockopt_key(ipv6 = _L, multicast_if = _Opt, _Dir, _D, T, _P) 
+  when (T =:= dgram) orelse (T =:= raw) ->
+    ?SOCKET_OPT_IPV6_MULTICAST_IF;
+enc_sockopt_key(ipv6 = _L, multicast_loop = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_MULTICAST_LOOP;
+enc_sockopt_key(ipv6 = L, portrange = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = L, pktoptions = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = _L, recverr = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_RECVERR;
+enc_sockopt_key(ipv6 = _L, Opt, _Dir, _D, T, _P) 
+  when ((Opt =:= recvpktinfo) orelse (Opt =:= pktinfo)) andalso 
+       ((T =:= dgram) orelse (T =:= raw)) ->
+    ?SOCKET_OPT_IPV6_RECVPKTINFO;
+enc_sockopt_key(ipv6 = L, recvtclass = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = _L, router_alert = _Opt, _Dir, _D, T, _P) when (T =:= raw) ->
+    ?SOCKET_OPT_IPV6_ROUTER_ALERT;
+enc_sockopt_key(ipv6 = _L, rthdr = _Opt, _Dir, _D, T, _P) 
+  when ((T =:= dgram) orelse (T =:= raw)) ->
+    ?SOCKET_OPT_IPV6_RTHDR;
+enc_sockopt_key(ipv6 = L, tclass = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = _L, unicast_hops = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_UNICAST_HOPS;
+enc_sockopt_key(ipv6 = L, use_min_mtu = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(ipv6 = _L, v6only = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_IPV6_V6ONLY;
+enc_sockopt_key(ipv6 = L, UnknownOpt, _Dir, _D, _T, _P) ->
+    unknown({L, UnknownOpt});
+
+%% TCP socket options
+%% There are other options that would be useful; info,
+%% but they are difficult to get portable...
+enc_sockopt_key(tcp, congestion = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_TCP_CONGESTION;
+enc_sockopt_key(tcp = L, cork = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(tcp = L, keepidle = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(tcp = L, keepintvl = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(tcp = L, keepcnt = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(tcp, maxseg = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_TCP_MAXSEG;
+enc_sockopt_key(tcp = L, md5sig = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(tcp, nodelay = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_TCP_NODELAY;
+enc_sockopt_key(tcp = L, noopt = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(tcp = L, nopush = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(tcp = L, syncnt = Opt, _Dir, _D, _T, _P) -> % Only set? 1..255
+    not_supported({L, Opt});
+enc_sockopt_key(tcp = L, user_timeout = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(tcp = L, UnknownOpt, _Dir, _D, _T, _P) ->
+    unknown({L, UnknownOpt});
+
+%% UDP socket options
+enc_sockopt_key(udp, cork = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_UDP_CORK;
+enc_sockopt_key(udp = L, UnknownOpt, _Dir, _D, _T, _P) ->
+    unknown({L, UnknownOpt});
+
+%% SCTP socket options
+enc_sockopt_key(sctp = L, adaption_layer = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = _L, associnfo = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SCTP_ASSOCINFO;
+enc_sockopt_key(sctp = L, auth_active_key = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, auth_asconf = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, auth_chunk = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, auth_key = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, auth_delete_key = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp, autoclose = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SCTP_AUTOCLOSE;
+enc_sockopt_key(sctp = L, context = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, default_send_params = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, delayed_ack_time = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = _L, disable_fragments = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SCTP_DISABLE_FRAGMENTS;
+enc_sockopt_key(sctp = L, hmac_ident = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = _L, events = _Opt, set = _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SCTP_EVENTS;
+enc_sockopt_key(sctp = L, explicit_eor = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, fragment_interleave = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, get_peer_addr_info = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = _L, initmsg = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SCTP_INITMSG;
+enc_sockopt_key(sctp = L, i_want_mapped_v4_addr = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, local_auth_chunks = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = _L, maxseg = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SCTP_MAXSEG;
+enc_sockopt_key(sctp = L, maxburst = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp, nodelay = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SCTP_NODELAY;
+enc_sockopt_key(sctp = L, partial_delivery_point = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, peer_addr_params = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, peer_auth_chunks = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, primary_addr = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, reset_streams = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = _L, rtoinfo = _Opt, _Dir, _D, _T, _P) ->
+    ?SOCKET_OPT_SCTP_RTOINFO;
+enc_sockopt_key(sctp = L, set_peer_primary_addr = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, status = Opt, get = _Dir, _D, _T, _P) ->
+    not_supported({L, Opt}); % ?SOCKET_OPT_SCTP_RTOINFO;
+enc_sockopt_key(sctp = L, use_exp_recvinfo = Opt, _Dir, _D, _T, _P) ->
+    not_supported({L, Opt});
+enc_sockopt_key(sctp = L, UnknownOpt, _Dir, _D, _T, _P) ->
+    unknown({L, UnknownOpt});
+
+%% +++ "Native" socket options +++
+enc_sockopt_key(Level, Opt, set = _Dir, _D, _T, _P)
+  when is_integer(Level) andalso is_integer(Opt) ->
+    Opt;
+enc_sockopt_key(Level, {NativeOpt, ValueSize} = Opt, get = _Dir, _D, _T, _P)
+  when is_integer(Level) andalso
+       is_integer(NativeOpt) andalso
+       ((is_integer(ValueSize) andalso (ValueSize >= 0)) orelse
+        ((ValueSize =:= int) orelse (ValueSize =:= bool))) ->
+    Opt;
+
+enc_sockopt_key(Level, Opt, _Dir, _Domain, _Type, _Protocol) ->
+    unknown({Level, Opt}).
+
+
+
+enc_shutdown_how(read) ->
+    ?SOCKET_SHUTDOWN_HOW_READ;
+enc_shutdown_how(write) ->
+    ?SOCKET_SHUTDOWN_HOW_WRITE;
+enc_shutdown_how(read_write) ->
+    ?SOCKET_SHUTDOWN_HOW_READ_WRITE.
+
+
+
+
+%% ===========================================================================
+%%
+%% Misc utility functions
+%%
+%% ===========================================================================
+
+-dialyzer({nowarn_function, ensure_ip_msfilter_slist/1}).
+ensure_ip_msfilter_slist(SL) ->
+    EnsureSA = fun(SA) when is_tuple(SA) andalso (size(SA) =:= 4) -> ok;
+                  (_) -> einval()
+               end,
+    lists:foreach(EnsureSA, SL).
+
+
+ensure_sockaddr(#{family := inet} = SockAddr) ->
+    maps:merge(?SOCKADDR_IN4_DEFAULTS, SockAddr);
+ensure_sockaddr(#{family := inet6} = SockAddr) ->
+    maps:merge(?SOCKADDR_IN6_DEFAULTS, SockAddr);
+ensure_sockaddr(#{family := local, path := Path} = SockAddr) 
+  when is_list(Path) andalso 
+       (length(Path) > 0) andalso 
+       (length(Path) =< 255) ->
+    BinPath = unicode:characters_to_binary(Path, file:native_name_encoding()),
+    ensure_sockaddr(SockAddr#{path => BinPath});
+ensure_sockaddr(#{family := local, path := Path} = SockAddr) 
+  when is_binary(Path) andalso 
+       (byte_size(Path) > 0) andalso 
+       (byte_size(Path) =< 255) ->
+    SockAddr;
+ensure_sockaddr(_SockAddr) ->
+    einval().
+
+
+
+cancel(SockRef, Op, OpRef) ->
+    case nif_cancel(SockRef, Op, OpRef) of
+        %% The select has already completed
+        {error, select_sent} ->
+            flush_select_msgs(SockRef, OpRef);
+        Other ->
+            Other
+    end.
+
+flush_select_msgs(SockRef, Ref) ->
+    receive
+        {?SOCKET_TAG, #socket{ref = SockRef}, select, Ref} ->
+            flush_select_msgs(SockRef, Ref)
+    after 0 ->
+            ok
+    end.
+
+
+%% formated_timestamp() ->
+%%     format_timestamp(os:timestamp()).
+
+%% format_timestamp(Now) ->
+%%     N2T = fun(N) -> calendar:now_to_local_time(N) end,
+%%     format_timestamp(Now, N2T, true).
+
+%% format_timestamp({_N1, _N2, N3} = N, N2T, true) ->
+%%     FormatExtra = ".~.2.0w",
+%%     ArgsExtra   = [N3 div 10000],
+%%     format_timestamp(N, N2T, FormatExtra, ArgsExtra);
+%% format_timestamp({_N1, _N2, _N3} = N, N2T, false) ->
+%%     FormatExtra = "",
+%%     ArgsExtra   = [],
+%%     format_timestamp(N, N2T, FormatExtra, ArgsExtra).
+
+%% format_timestamp(N, N2T, FormatExtra, ArgsExtra) ->
+%%     {Date, Time}   = N2T(N),
+%%     {YYYY,MM,DD}   = Date,
+%%     {Hour,Min,Sec} = Time,
+%%     FormatDate =
+%%         io_lib:format("~.4w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w" ++ FormatExtra,
+%%                       [YYYY, MM, DD, Hour, Min, Sec] ++ ArgsExtra),
+%%     lists:flatten(FormatDate).
+
+
+%% A timestamp in ms
+
+timestamp(nowait = T) ->
+    T;
+timestamp(infinity) ->
+    undefined;
+timestamp(_) ->
+    timestamp().
+
+timestamp() ->
+    erlang:monotonic_time(milli_seconds).
+
+next_timeout(_, nowait = Timeout) ->
+    Timeout;
+next_timeout(_, infinity = Timeout) ->
+    Timeout;
+next_timeout(TS, Timeout) ->
+    NewTimeout = Timeout - tdiff(TS, timestamp()),
+    if
+        (NewTimeout > 0) ->
+            NewTimeout;
+        true ->
+            0
+    end.
+
+tdiff(T1, T2) ->
+    T2 - T1.
+
+
+
+%% p(F) ->
+%%     p(F, []).
+
+%% p(F, A) ->
+%%     p(get(sname), F, A).
+
+%% p(undefined, F, A) ->
+%%     p("***", F, A);
+%% p(SName, F, A) ->
+%%     TS = formated_timestamp(),
+%%     io:format(user,"[~s][~s,~p] " ++ F ++ "~n", [TS, SName, self()|A]),
+%%     io:format("[~s][~s,~p] " ++ F ++ "~n", [TS, SName, self()|A]).
+
+
+
+%% ===========================================================================
+%%
+%% Error functions
+%%
+%% ===========================================================================
+
+-spec invalid_domain(Domain) -> no_return() when
+      Domain :: term().
+
+invalid_domain(Domain) ->
+    error({invalid_domain, Domain}).
+
+-spec invalid_type(Type) -> no_return() when
+      Type :: term().
+
+invalid_type(Type) ->
+    error({invalid_type, Type}).
+
+-spec invalid_protocol(Type, Proto) -> no_return() when
+      Type  :: term(),
+      Proto :: term().
+
+invalid_protocol(Type, Proto) ->
+    error({invalid_protocol, {Type, Proto}}).
+
+-spec not_supported(What) -> no_return() when
+      What :: term().
+
+not_supported(What) ->
+    error({not_supported, What}).
+
+-spec unknown(What) -> no_return() when
+      What :: term().
+
+unknown(What) ->
+    error({unknown, What}).
+
+-spec einval() -> no_return().
+
+einval() ->
+    error(einval).
+
+-spec error(Reason) -> no_return() when
+      Reason :: term().
+
+error(Reason) ->
+    throw({error, Reason}).
+
+
+%% ===========================================================================
+%%
+%% Below follows the actual NIF-functions.
+%%
+%% ===========================================================================
+
+nif_info() ->
+    erlang:nif_error(undef).
+
+nif_info(_SRef) ->
+    erlang:nif_error(undef).
+
+nif_command(_Command) ->
+    erlang:nif_error(undef).
+
+nif_supports(_Key) ->
+    erlang:nif_error(undef).
+
+nif_open(_Domain, _Type, _Protocol, _Extra) ->
+    erlang:nif_error(undef).
+
+nif_bind(_SRef, _SockAddr) ->
+    erlang:nif_error(undef).
+
+nif_bind(_SRef, _SockAddrs, _Action) ->
+    erlang:nif_error(undef).
+
+nif_connect(_SRef, _SockAddr) ->
+    erlang:nif_error(undef).
+
+nif_finalize_connection(_SRef) ->
+    erlang:nif_error(undef).
+
+nif_listen(_SRef, _Backlog) ->
+    erlang:nif_error(undef).
+
+nif_accept(_SRef, _Ref) ->
+    erlang:nif_error(undef).
+
+nif_send(_SockRef, _SendRef, _Data, _Flags) ->
+    erlang:nif_error(undef).
+
+nif_sendto(_SRef, _SendRef, _Data, _Dest, _Flags) ->
+    erlang:nif_error(undef).
+
+nif_sendmsg(_SRef, _SendRef, _MsgHdr, _Flags) ->
+    erlang:nif_error(undef).
+
+nif_recv(_SRef, _RecvRef, _Length, _Flags) ->
+    erlang:nif_error(undef).
+
+nif_recvfrom(_SRef, _RecvRef, _Length, _Flags) ->
+    erlang:nif_error(undef).
+
+nif_recvmsg(_SRef, _RecvRef, _BufSz, _CtrlSz, _Flags) ->
+    erlang:nif_error(undef).
+
+nif_cancel(_SRef, _Op, _Ref) ->
+    erlang:nif_error(undef).
+
+nif_close(_SRef) ->
+    erlang:nif_error(undef).
+
+nif_shutdown(_SRef, _How) ->
+    erlang:nif_error(undef).
+
+nif_finalize_close(_SRef) ->
+    erlang:nif_error(undef).
+
+nif_setopt(_Ref, _IsEnc, _Lev, _Key, _Val) ->
+    erlang:nif_error(undef).
+
+nif_getopt(_Ref, _IsEnc, _Lev, _Key) ->
+    erlang:nif_error(undef).
+
+nif_sockname(_Ref) ->
+    erlang:nif_error(undef).
+
+nif_peername(_Ref) ->
+    erlang:nif_error(undef).
+
diff --git a/erts/test/erlexec_SUITE.erl b/erts/test/erlexec_SUITE.erl
index 602dc5ce2e..952e6da4dc 100644
--- a/erts/test/erlexec_SUITE.erl
+++ b/erts/test/erlexec_SUITE.erl
@@ -30,7 +30,7 @@
 -export([all/0, suite/0, init_per_testcase/2, end_per_testcase/2]).
 
 -export([args_file/1, evil_args_file/1, env/1, args_file_env/1,
-         otp_7461/1, otp_7461_remote/1, otp_8209/1,
+         otp_7461/1, otp_7461_remote/1, argument_separation/1,
          zdbbl_dist_buf_busy_limit/1]).
 
 -include_lib("common_test/include/ct.hrl").
@@ -51,21 +51,28 @@ suite() ->
 
 all() -> 
     [args_file, evil_args_file, env, args_file_env,
-     otp_7461, otp_8209, zdbbl_dist_buf_busy_limit].
+     otp_7461, argument_separation, zdbbl_dist_buf_busy_limit].
 
 %% Test that plain first argument does not
-%% destroy -home switch [OTP-8209]
-otp_8209(Config) when is_list(Config) ->
+%% destroy -home switch [OTP-8209] or interact with environments
+argument_separation(Config) when is_list(Config) ->
     {ok,[[PName]]} = init:get_argument(progname),
     SNameS = "erlexec_test_01",
     SName = list_to_atom(SNameS++"@"++
 			 hd(tl(string:lexemes(atom_to_list(node()),"@")))),
-    Cmd = PName ++ " dummy_param -sname "++SNameS++" -setcookie "++
-	atom_to_list(erlang:get_cookie()),
-    open_port({spawn,Cmd},[]),
+    Cmd = PName ++ " cmd_param -sname "++SNameS++" -setcookie "++
+	atom_to_list(erlang:get_cookie()) ++ " -cmd_test",
+    open_port({spawn,Cmd},[{env,[{"ERL_AFLAGS","-atest"},
+                                 {"ERL_FLAGS","env_param -test"},
+                                 {"ERL_ZFLAGS","zenv_param"}]}]),
     pong = loop_ping(SName,40),
+    ct:log("emu_args: ~p",[rpc:call(SName,erlang,system_info,[emu_args])]),
     {ok,[[_]]} = rpc:call(SName,init,get_argument,[home]),
-    ["dummy_param"] = rpc:call(SName,init,get_plain_arguments,[]),
+    {ok,[[]]} = rpc:call(SName,init,get_argument,[atest]),
+    {ok,[[]]} = rpc:call(SName,init,get_argument,[cmd_test]),
+    {ok,[[]]} = rpc:call(SName,init,get_argument,[test]),
+    error = rpc:call(SName,init,get_argument,[unkown]),
+    ["cmd_param","env_param","zenv_param"] = rpc:call(SName,init,get_plain_arguments,[]),
     ok = cleanup_nodes(),
     ok.
 
@@ -85,6 +92,7 @@ cleanup_node(SNameS,N) ->
     end.
 
 loop_ping(_,0) ->
+    flush(),
     pang;
 loop_ping(Node,N) ->
     case net_adm:ping(Node) of
@@ -98,6 +106,14 @@ loop_ping(Node,N) ->
 	    pong
     end.
 
+flush() ->
+    receive M ->
+            ct:pal("~p",[M]),
+            flush()
+    after 10 ->
+            ok
+    end.
+
 args_file(Config) when is_list(Config) ->
     AFN1 = privfile("1", Config),
     AFN2 = privfile("2", Config),
diff --git a/erts/test/upgrade_SUITE.erl b/erts/test/upgrade_SUITE.erl
index c32dbabe8d..f92c25bdb4 100644
--- a/erts/test/upgrade_SUITE.erl
+++ b/erts/test/upgrade_SUITE.erl
@@ -25,7 +25,7 @@
 
 -define(upgr_sname,otp_upgrade).
 
-%% Applications that are excluded from this test because they can not
+%% Applications that are excluded from this test because they cannot
 %% just be started in a new node with out specific configuration.
 -define(start_exclude,
 	[cosEvent,cosEventDomain,cosFileTransfer,cosNotification,
diff --git a/erts/test/z_SUITE.erl b/erts/test/z_SUITE.erl
index 6a34299dd2..536212af2e 100644
--- a/erts/test/z_SUITE.erl
+++ b/erts/test/z_SUITE.erl
@@ -88,10 +88,10 @@ find_cerl(DBTop) ->
 	[Cerl | _ ] ->
 	    case filelib:is_regular(Cerl) of
 		true -> Cerl;
-		_ -> false
+		_ -> find_cerl(false)
 	    end;
 	_ ->
-	    false
+	    find_cerl(false)
     end.
 
 is_dir(false) ->
diff --git a/erts/vsn.mk b/erts/vsn.mk
index 0adee946cc..f06fd08540 100644
--- a/erts/vsn.mk
+++ b/erts/vsn.mk
@@ -18,7 +18,7 @@
 # %CopyrightEnd%
 # 
 
-VSN = 10.2
+VSN = 10.4.4
 
 # Port number 4365 in 4.2
 # Port number 4366 in 4.3