Merge branch 'rickard/time_api/OTP-11997'

* rickard/time_api/OTP-11997: (22 commits) Update primary bootstrap inets: Suppress deprecated warning on erlang:now/0 inets: Cleanup of multiple copies of functions Add inets_lib with common functions used by multiple modules inets: Update comments Suppress deprecated warning on erlang:now/0 Use new time API and be back-compatible in inets Remove unused functions and removed redundant test asn1 test SUITE: Eliminate use of now/0 Disable deprecated warning on erlang:now/0 in diameter_lib Use new time API and be back-compatible in ssh Replace all calls to now/0 in CT with new time API functions test_server: Replace usage of erlang:now() with usage of new API Replace usage of erlang:now() with usage of new API Replace usage of erlang:now() with usage of new API Replace usage of erlang:now() with usage of new API Replace usage of erlang:now() with usage of new API otp_SUITE: Warn for calls to erlang:now/0 Replace usage of erlang:now() with usage of new API Multiple timer wheels Erlang based BIF timer implementation for scalability Implement ethread events with timeout ... Conflicts: bootstrap/bin/start.boot bootstrap/bin/start_clean.boot bootstrap/lib/compiler/ebin/beam_asm.beam bootstrap/lib/compiler/ebin/compile.beam bootstrap/lib/kernel/ebin/auth.beam bootstrap/lib/kernel/ebin/dist_util.beam bootstrap/lib/kernel/ebin/global.beam bootstrap/lib/kernel/ebin/hipe_unified_loader.beam bootstrap/lib/kernel/ebin/inet_db.beam bootstrap/lib/kernel/ebin/inet_dns.beam bootstrap/lib/kernel/ebin/inet_res.beam bootstrap/lib/kernel/ebin/os.beam bootstrap/lib/kernel/ebin/pg2.beam bootstrap/lib/stdlib/ebin/dets.beam bootstrap/lib/stdlib/ebin/dets_utils.beam bootstrap/lib/stdlib/ebin/erl_tar.beam bootstrap/lib/stdlib/ebin/escript.beam bootstrap/lib/stdlib/ebin/file_sorter.beam bootstrap/lib/stdlib/ebin/otp_internal.beam bootstrap/lib/stdlib/ebin/qlc.beam bootstrap/lib/stdlib/ebin/random.beam bootstrap/lib/stdlib/ebin/supervisor.beam bootstrap/lib/stdlib/ebin/timer.beam erts/aclocal.m4 erts/emulator/beam/bif.c erts/emulator/beam/erl_bif_info.c erts/emulator/beam/erl_db_hash.c erts/emulator/beam/erl_init.c erts/emulator/beam/erl_process.h erts/emulator/beam/erl_thr_progress.c erts/emulator/beam/utils.c erts/emulator/sys/unix/sys.c erts/preloaded/ebin/erlang.beam erts/preloaded/ebin/erts_internal.beam erts/preloaded/ebin/init.beam erts/preloaded/src/erts_internal.erl lib/common_test/test/ct_hooks_SUITE_data/cth/tests/empty_cth.erl lib/diameter/src/base/diameter_lib.erl lib/kernel/src/os.erl lib/ssh/test/ssh_basic_SUITE.erl system/doc/efficiency_guide/advanced.xml
author: Rickard Green <[email protected]> 2015-03-20 21:29:30 +0100
committer: Rickard Green <[email protected]> 2015-03-20 21:29:30 +0100
commit: f4e3cd1c970cfc5ad54f2ed64832d05749c305d4 (patch)
tree: a008c88d68c801ac290373920435d952b027905c /erts/emulator
parent: c0d3f4cbb5775a9214366e0d9cb76847d69c3459 (diff)
parent: e7a713167e3390bfa7d7ada2eafe5fe16f185405 (diff)
download: otp-f4e3cd1c970cfc5ad54f2ed64832d05749c305d4.tar.gz
otp-f4e3cd1c970cfc5ad54f2ed64832d05749c305d4.tar.bz2
otp-f4e3cd1c970cfc5ad54f2ed64832d05749c305d4.zip
56 files changed, 5814 insertions, 1372 deletions
diff --git a/erts/emulator/Makefile.in b/erts/emulator/Makefile.in
index a632faf57d..1429a6cf2c 100644
--- a/erts/emulator/Makefile.in
+++ b/erts/emulator/Makefile.in
@@ -754,7 +754,8 @@ RUN_OBJS = \
 	$(OBJDIR)/erl_bif_ddll.o  	$(OBJDIR)/erl_bif_guard.o \
 	$(OBJDIR)/erl_bif_info.o	$(OBJDIR)/erl_bif_op.o \
 	$(OBJDIR)/erl_bif_os.o		$(OBJDIR)/erl_bif_lists.o \
-	$(OBJDIR)/erl_bif_trace.o	$(OBJDIR)/erl_bif_wrap.o \
+	$(OBJDIR)/erl_bif_trace.o	$(OBJDIR)/erl_bif_unique.o \
+	$(OBJDIR)/erl_bif_wrap.o \
 	$(OBJDIR)/erl_trace.o		$(OBJDIR)/copy.o \
 	$(OBJDIR)/utils.o		$(OBJDIR)/bif.o \
 	$(OBJDIR)/io.o 			$(OBJDIR)/erl_printf_term.o\
diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index c097866c7e..ae3f30d82f 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -109,6 +109,7 @@ atom bag
 atom band
 atom big
 atom bif_return_trap
+atom bif_timer_server
 atom binary
 atom binary_bin_to_list_trap
 atom binary_copy_trap
@@ -144,9 +145,11 @@ atom catchlevel
 atom cd
 atom cdr
 atom cflags
+atom CHANGE='CHANGE'
 atom characters_to_binary_int
 atom characters_to_list_int
 atom clear
+atom clock_service
 atom close
 atom closed
 atom code
@@ -156,6 +159,7 @@ atom compat_rel
 atom compile
 atom compressed
 atom config_h
+atom convert_time_unit
 atom connect
 atom connected
 atom connection_closed
@@ -237,7 +241,7 @@ atom first
 atom firstline
 atom flags
 atom flush
-atom flush_monitor_message
+atom flush_monitor_messages
 atom force
 atom format_cpu_topology
 atom free
@@ -345,6 +349,8 @@ atom message_queue_len
 atom messages
 atom meta
 atom meta_match_spec
+atom micro_seconds
+atom milli_seconds
 atom min_heap_size
 atom min_bin_vheap_size
 atom minor_version
@@ -355,12 +361,15 @@ atom monitored_by
 atom monitor
 atom monitor_nodes
 atom monitors
+atom monotonic
 atom more
 atom multi_scheduling
 atom multiline
+atom nano_seconds
 atom name
 atom named_table
 atom namelist
+atom native
 atom native_addresses
 atom Neq='=/='
 atom Neqeq='/='
@@ -451,6 +460,7 @@ atom ports
 atom port_count
 atom port_limit
 atom port_op
+atom positive
 atom print
 atom priority
 atom private
@@ -510,6 +520,7 @@ atom schedulers_online
 atom scheme
 atom scientific
 atom scope
+atom seconds
 atom sensitive
 atom sequential_tracer
 atom sequential_trace_token
@@ -555,6 +566,7 @@ atom term_to_binary_trap
 atom this
 atom thread_pool_size
 atom threads
+atom time_offset
 atom timeout
 atom timeout_value
 atom Times='*'
diff --git a/erts/emulator/beam/benchmark.h b/erts/emulator/beam/benchmark.h
index 904564a96b..7fc3933f3d 100644
--- a/erts/emulator/beam/benchmark.h
+++ b/erts/emulator/beam/benchmark.h
@@ -141,10 +141,10 @@ extern unsigned long long major_gc;
 
 /* (Assuming Solaris) */
 
-#define BM_TIMER_T hrtime_t
-#define BM_START_TIMER(t) system_clock = sys_gethrtime()
+#define BM_TIMER_T ErtsMonotonicTime
+#define BM_START_TIMER(t) system_clock = ERTS_MONOTONIC_TO_NSEC(erts_os_monotonic_time())
 #define BM_STOP_TIMER(t) do {                                        \
-    BM_TIMER_T tmp = (sys_gethrtime() - system_clock) - timer_time;  \
+    BM_TIMER_T tmp = (ERTS_MONOTONIC_TO_NSEC(erts_os_monotonic_time()) - system_clock) - timer_time;  \
     t##_time += (tmp > 0 ? tmp : 0);                                 \
 } while(0)
 
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 49996e7f0b..af02a55b69 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -42,16 +42,22 @@
 #define ERTS_PTAB_WANT_BIF_IMPL__
 #include "erl_ptab.h"
 #include "erl_bits.h"
+#include "erl_bif_unique.h"
 
-static Export* flush_monitor_message_trap = NULL;
+static Export* flush_monitor_messages_trap = NULL;
 static Export* set_cpu_topology_trap = NULL;
 static Export* await_proc_exit_trap = NULL;
 static Export* await_port_send_result_trap = NULL;
 Export* erts_format_cpu_topology_trap = NULL;
 static Export dsend_continue_trap_export;
+Export *erts_convert_time_unit_trap = NULL;
+
 static Export *await_sched_wall_time_mod_trap;
 static erts_smp_atomic32_t sched_wall_time;
 
+static erts_smp_mtx_t ports_snapshot_mtx;
+erts_smp_atomic_t erts_dead_ports_ptr; /* To store dying ports during snapshot */
+
 #define DECL_AM(S) Eterm AM_ ## S = am_atom_put(#S, sizeof(#S) - 1)
 
 /*
@@ -393,7 +399,7 @@ remote_demonitor(Process *c_p, DistEntry *dep, Eterm ref, Eterm to)
     return res;
 }
 
-static int demonitor(Process *c_p, Eterm ref)
+static int demonitor(Process *c_p, Eterm ref, Eterm *multip)
 {
    ErtsMonitor *mon = NULL;  /* The monitor entry to delete */
    Process  *rp;    /* Local target process */
@@ -417,65 +423,73 @@ static int demonitor(Process *c_p, Eterm ref)
        goto done;
    }
 
-   if (mon->type != MON_ORIGIN) {
-       res = ERTS_DEMONITOR_BADARG;
-       goto done;
-   }
-   to = mon->pid;
-
-   if (is_atom(to)) {
-       /* Monitoring a name at node to */
-       ASSERT(is_node_name_atom(to));
-       dep = erts_sysname_to_connected_dist_entry(to);
-       ASSERT(dep != erts_this_dist_entry);
-       if (dep)
-	   deref_de = 1;
-   } else {
-       ASSERT(is_pid(to));
-       dep = pid_dist_entry(to);
-   }
-   if (dep != erts_this_dist_entry) {
-       res = remote_demonitor(c_p, dep, ref, to);
-       /* remote_demonitor() unlocks link lock on c_p */
-       unlock_link = 0;
-   }
-   else { /* Local monitor */
-       if (deref_de) {
-	   deref_de = 0;
-	   erts_deref_dist_entry(dep);
+   switch (mon->type) {
+   case MON_TIME_OFFSET:
+       *multip = am_true;
+       erts_demonitor_time_offset(ref);
+       res = ERTS_DEMONITOR_TRUE;
+       break;
+   case MON_ORIGIN:
+       to = mon->pid;
+       *multip = am_false;
+       if (is_atom(to)) {
+	   /* Monitoring a name at node to */
+	   ASSERT(is_node_name_atom(to));
+	   dep = erts_sysname_to_connected_dist_entry(to);
+	   ASSERT(dep != erts_this_dist_entry);
+	   if (dep)
+	       deref_de = 1;
+       } else {
+	   ASSERT(is_pid(to));
+	   dep = pid_dist_entry(to);
        }
-       dep = NULL;
-       rp = erts_pid2proc_opt(c_p,
-			      ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK,
-			      to,
-			      ERTS_PROC_LOCK_LINK,
-			      ERTS_P2P_FLG_ALLOW_OTHER_X);
-       mon = erts_remove_monitor(&ERTS_P_MONITORS(c_p), ref);
+       if (dep != erts_this_dist_entry) {
+	   res = remote_demonitor(c_p, dep, ref, to);
+	   /* remote_demonitor() unlocks link lock on c_p */
+	   unlock_link = 0;
+       }
+       else { /* Local monitor */
+	   if (deref_de) {
+	       deref_de = 0;
+	       erts_deref_dist_entry(dep);
+	   }
+	   dep = NULL;
+	   rp = erts_pid2proc_opt(c_p,
+				  ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK,
+				  to,
+				  ERTS_PROC_LOCK_LINK,
+				  ERTS_P2P_FLG_ALLOW_OTHER_X);
+	   mon = erts_remove_monitor(&ERTS_P_MONITORS(c_p), ref);
 #ifndef ERTS_SMP
-       ASSERT(mon);
+	   ASSERT(mon);
 #else
-       if (!mon)
-	   res = ERTS_DEMONITOR_FALSE;
-       else
+	   if (!mon)
+	       res = ERTS_DEMONITOR_FALSE;
+	   else
 #endif
-       {
-	   res = ERTS_DEMONITOR_TRUE;
-	   erts_destroy_monitor(mon);
-       }
-       if (rp) {
-	   ErtsMonitor *rmon;
-	   rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), ref);
-	   if (rp != c_p)
-	       erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
-	   if (rmon != NULL)
-	       erts_destroy_monitor(rmon);
-       }
-       else {
-	   ERTS_SMP_ASSERT_IS_NOT_EXITING(c_p);
-       }
+	   {
+	       res = ERTS_DEMONITOR_TRUE;
+	       erts_destroy_monitor(mon);
+	   }
+	   if (rp) {
+	       ErtsMonitor *rmon;
+	       rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), ref);
+	       if (rp != c_p)
+		   erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
+	       if (rmon != NULL)
+		   erts_destroy_monitor(rmon);
+	   }
+	   else {
+	       ERTS_SMP_ASSERT_IS_NOT_EXITING(c_p);
+	   }
 
+       }
+       break;
+   default:
+       res = ERTS_DEMONITOR_BADARG;
+       *multip = am_false;
+       break;
    }
-
  done:
 
    if (unlock_link)
@@ -492,7 +506,8 @@ static int demonitor(Process *c_p, Eterm ref)
 
 BIF_RETTYPE demonitor_1(BIF_ALIST_1)
 {
-    switch (demonitor(BIF_P, BIF_ARG_1)) {
+    Eterm multi;
+    switch (demonitor(BIF_P, BIF_ARG_1, &multi)) {
     case ERTS_DEMONITOR_FALSE:
     case ERTS_DEMONITOR_TRUE:
 	BIF_RET(am_true);
@@ -510,6 +525,7 @@ BIF_RETTYPE demonitor_1(BIF_ALIST_1)
 BIF_RETTYPE demonitor_2(BIF_ALIST_2)
 {
     Eterm res = am_true;
+    Eterm multi = am_false;
     int info = 0;
     int flush = 0;
     Eterm list = BIF_ARG_2;
@@ -532,13 +548,18 @@ BIF_RETTYPE demonitor_2(BIF_ALIST_2)
     if (is_not_nil(list))
 	goto badarg;
 
-    switch (demonitor(BIF_P, BIF_ARG_1)) {
+    switch (demonitor(BIF_P, BIF_ARG_1, &multi)) {
     case ERTS_DEMONITOR_FALSE:
 	if (info)
 	    res = am_false;
-	if (flush)
-	    BIF_TRAP2(flush_monitor_message_trap, BIF_P, BIF_ARG_1, res);
+	if (flush) {
+	flush_messages:
+	    BIF_TRAP3(flush_monitor_messages_trap, BIF_P,
+		      BIF_ARG_1, multi, res);
+	}
     case ERTS_DEMONITOR_TRUE:
+	if (multi == am_true && flush)
+	    goto flush_messages;
 	BIF_RET(res);
     case ERTS_DEMONITOR_YIELD_TRUE:
 	ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
@@ -597,14 +618,12 @@ erts_queue_monitor_message(Process *p,
 }
 
 static BIF_RETTYPE
-local_pid_monitor(Process *p, Eterm target)
+local_pid_monitor(Process *p, Eterm target, Eterm mon_ref, int bool)
 {
     BIF_RETTYPE ret;
-    Eterm mon_ref;
     Process *rp;
     ErtsProcLocks p_locks = ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK;
 
-    mon_ref = erts_make_ref(p);
     ERTS_BIF_PREP_RET(ret, mon_ref);
     if (target == p->common.id) {
 	return ret;
@@ -617,12 +636,18 @@ local_pid_monitor(Process *p, Eterm target)
     if (!rp) {
 	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
 	p_locks &= ~ERTS_PROC_LOCK_LINK;
-	erts_queue_monitor_message(p, &p_locks,
-				   mon_ref, am_process, target, am_noproc);
+	if (bool)
+	    ret = am_false;
+	else
+	    erts_queue_monitor_message(p, &p_locks,
+				       mon_ref, am_process, target, am_noproc);
     }
     else {
 	ASSERT(rp != p);
 
+	if (bool)
+	    ret = am_true;
+
 	erts_add_monitor(&ERTS_P_MONITORS(p), MON_ORIGIN, mon_ref, target, NIL);
 	erts_add_monitor(&ERTS_P_MONITORS(rp), MON_TARGET, mon_ref, p->common.id, NIL);
 
@@ -746,13 +771,28 @@ BIF_RETTYPE monitor_2(BIF_ALIST_2)
     int deref_de = 0;
 
     /* Only process monitors are implemented */
-    if (BIF_ARG_1 != am_process) {
+    switch (BIF_ARG_1) {
+    case am_time_offset: {
+	Eterm ref;
+	if (BIF_ARG_2 != am_clock_service)
+	    goto error;
+	ref = erts_make_ref(BIF_P);
+	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK);
+	erts_add_monitor(&ERTS_P_MONITORS(BIF_P), MON_TIME_OFFSET,
+			 ref, am_clock_service, NIL);
+	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
+	erts_monitor_time_offset(BIF_P->common.id, ref);
+	BIF_RET(ref);
+    }
+    case am_process:
+	break;
+    default:
 	goto error;
     }
 
     if (is_internal_pid(target)) {
     local_pid:
-	ret = local_pid_monitor(BIF_P, target);
+	ret = local_pid_monitor(BIF_P, target, erts_make_ref(BIF_P), 0);
     } else if (is_external_pid(target)) {
 	dep = external_pid_dist_entry(target);
 	if (dep == erts_this_dist_entry)
@@ -795,6 +835,25 @@ BIF_RETTYPE monitor_2(BIF_ALIST_2)
     return ret;
 }
 
+BIF_RETTYPE erts_internal_monitor_process_2(BIF_ALIST_2)
+{
+    if (is_not_internal_pid(BIF_ARG_1)) {
+	if (is_external_pid(BIF_ARG_1)
+	    && (external_pid_dist_entry(BIF_ARG_1)
+		== erts_this_dist_entry)) {
+	    BIF_RET(am_false);
+	}
+	goto badarg;
+    }
+
+    if (is_not_internal_ref(BIF_ARG_2))
+	goto badarg;
+
+    BIF_RET(local_pid_monitor(BIF_P, BIF_ARG_1, BIF_ARG_2, 1));
+
+badarg:
+    BIF_ERROR(BIF_P, BADARG);
+}
 
 /**********************************************************************/
 /* this is a combination of the spawn and link BIFs */
@@ -3542,91 +3601,6 @@ BIF_RETTYPE self_0(BIF_ALIST_0)
 
 /**********************************************************************/
 
-/*
-   New representation of refs in R9, see erl_term.h
-
-   In the first data word, only the usual 18 bits are used. Ordinarily,
-   in "long refs" all words are used (in other words, practically never
-   wrap around), but for compatibility with older nodes, "short refs"
-   exist. Short refs come into being by being converted from the old
-   external format for refs (tag REFERENCE_EXT). Short refs are
-   converted back to the old external format.
-
-   When converting a long ref to the external format in the case of
-   preparing for sending to an older node, the ref is truncated by only
-   using the first word (with 18 significant bits), and using the old tag
-   REFERENCE_EXT.
-
-   When comparing refs or different size, only the parts up to the length
-   of the shorter operand are used. This has the desirable effect that a
-   long ref sent to an old node and back will be treated as equal to
-   the original, although some of the bits have been lost.
-
-   The hash value for a ref always considers only the first word, since
-   in the above scenario, the original and the copy should have the same
-   hash value.
-*/
-
-static Uint32 reference0; /* Initialized in erts_init_bif */
-static Uint32 reference1;
-static Uint32 reference2;
-static erts_smp_spinlock_t make_ref_lock;
-static erts_smp_mtx_t ports_snapshot_mtx;
-erts_smp_atomic_t erts_dead_ports_ptr; /* To store dying ports during snapshot */
-
-void
-erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS])
-{
-    erts_smp_spin_lock(&make_ref_lock);
-
-    reference0++;
-    if (reference0 >= MAX_REFERENCE) {
-	reference0 = 0;
-	reference1++;
-	if (reference1 == 0) {
-	    reference2++;
-	}
-    }
-
-    ref[0] = reference0;
-    ref[1] = reference1;
-    ref[2] = reference2;
-
-    erts_smp_spin_unlock(&make_ref_lock);
-}
-
-Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE])
-{
-    Eterm* hp = buffer;
-    Uint32 ref[ERTS_MAX_REF_NUMBERS];
-
-    erts_make_ref_in_array(ref);
-    write_ref_thing(hp, ref[0], ref[1], ref[2]);
-    return make_internal_ref(hp);
-}
-
-Eterm erts_make_ref(Process *p)
-{
-    Eterm* hp;
-    Uint32 ref[ERTS_MAX_REF_NUMBERS];
-
-    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(p));
-
-    hp = HAlloc(p, REF_THING_SIZE);
-
-    erts_make_ref_in_array(ref);
-    write_ref_thing(hp, ref[0], ref[1], ref[2]);
-
-    return make_internal_ref(hp);
-}
-
-BIF_RETTYPE make_ref_0(BIF_ALIST_0)
-{
-    return erts_make_ref(BIF_P);
-}
-
-/**********************************************************************/
-
 /* return the time of day */
 
 BIF_RETTYPE time_0(BIF_ALIST_0)
@@ -4607,6 +4581,28 @@ BIF_RETTYPE system_flag_2(BIF_ALIST_2)
 	    break;
 	}
 #endif
+    } else if (BIF_ARG_1 == am_time_offset
+	       && ERTS_IS_ATOM_STR("finalize", BIF_ARG_2)) {
+	ErtsTimeOffsetState res;
+	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
+	res = erts_finalize_time_offset();
+        erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
+	switch (res) {
+	case ERTS_TIME_OFFSET_PRELIMINARY: {
+	    DECL_AM(preliminary);
+	    BIF_RET(AM_preliminary);
+	}
+	case ERTS_TIME_OFFSET_FINAL: {
+	    DECL_AM(final);
+	    BIF_RET(AM_final);
+	}
+	case ERTS_TIME_OFFSET_VOLATILE: {
+	    DECL_AM(volatile);
+	    BIF_RET(AM_volatile);
+	}
+	default:
+	    ERTS_INTERNAL_ERROR("Unknown state");
+	}
     } else if (ERTS_IS_ATOM_STR("scheduling_statistics", BIF_ARG_1)) {
 	int what;
 	if (ERTS_IS_ATOM_STR("disable", BIF_ARG_2))
@@ -4894,11 +4890,6 @@ void erts_init_trap_export(Export* ep, Eterm m, Eterm f, Uint a,
 
 void erts_init_bif(void)
 {
-    reference0 = 0;
-    reference1 = 0;
-    reference2 = 0;
-
-    erts_smp_spinlock_init(&make_ref_lock, "make_ref");
     erts_smp_mtx_init(&ports_snapshot_mtx, "ports_snapshot");
     erts_smp_atomic_init_nob(&erts_dead_ports_ptr, (erts_aint_t) NULL);
 
@@ -4919,9 +4910,13 @@ void erts_init_bif(void)
 			  am_erts_internal, am_dsend_continue_trap, 1,
 			  dsend_continue_trap_1);
 
-    flush_monitor_message_trap = erts_export_put(am_erlang,
-						 am_flush_monitor_message,
-						 2);
+    flush_monitor_messages_trap = erts_export_put(am_erts_internal,
+						  am_flush_monitor_messages,
+						  3);
+
+    erts_convert_time_unit_trap = erts_export_put(am_erlang,
+						  am_convert_time_unit,
+						  3);
 
     set_cpu_topology_trap = erts_export_put(am_erlang,
 					    am_set_cpu_topology,
diff --git a/erts/emulator/beam/bif.h b/erts/emulator/beam/bif.h
index 837cb017ac..d461c3f479 100644
--- a/erts/emulator/beam/bif.h
+++ b/erts/emulator/beam/bif.h
@@ -21,6 +21,7 @@
 #define __BIF_H__
 
 extern Export* erts_format_cpu_topology_trap;
+extern Export *erts_convert_time_unit_trap;
 
 #define BIF_RETTYPE Eterm
 
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index 5a0ee2ffc3..471f687101 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -92,6 +92,8 @@ bif erlang:loaded/0
 bif erlang:localtime/0
 bif erlang:localtime_to_universaltime/2
 bif erlang:make_ref/0
+bif erlang:unique_integer/0
+bif erlang:unique_integer/1
 bif erlang:md5/1
 bif erlang:md5_init/0
 bif erlang:md5_update/2
@@ -104,6 +106,13 @@ ubif erlang:node/1
 ubif erlang:node/0
 bif erlang:nodes/1
 bif erlang:now/0
+bif erlang:monotonic_time/0
+bif erlang:monotonic_time/1
+bif erlang:system_time/0
+bif erlang:system_time/1
+bif erlang:time_offset/0
+bif erlang:time_offset/1
+bif erlang:timestamp/0
 
 bif erlang:open_port/2
 
@@ -160,6 +169,15 @@ bif erts_internal:map_to_tuple_keys/1
 bif erts_internal:map_type/1
 bif erts_internal:map_hashmap_children/1
 
+bif erts_internal:time_unit/0
+
+bif erts_internal:get_bif_timer_servers/0
+bif erts_internal:create_bif_timer/0
+bif erts_internal:access_bif_timer/1
+
+bif erts_internal:monitor_process/2
+bif erts_internal:is_system_process/1
+
 # inet_db support
 bif erlang:port_set_data/2
 bif erlang:port_get_data/1
@@ -202,11 +220,6 @@ bif math:sqrt/1
 bif math:atan2/2
 bif math:pow/2
 
-bif erlang:start_timer/3
-bif erlang:send_after/3
-bif erlang:cancel_timer/1
-bif erlang:read_timer/1
-
 bif erlang:make_tuple/2
 bif erlang:append_element/2
 bif erlang:make_tuple/3
@@ -350,6 +363,8 @@ bif os:getenv/0
 bif os:getenv/1
 bif os:getpid/0
 bif os:timestamp/0
+bif os:system_time/0
+bif os:system_time/1
 
 #
 # Bifs in the erl_ddll module (the module actually does not exist)
diff --git a/erts/emulator/beam/big.c b/erts/emulator/beam/big.c
index d1e46e3063..a4ea9c59ca 100644
--- a/erts/emulator/beam/big.c
+++ b/erts/emulator/beam/big.c
@@ -1577,6 +1577,46 @@ Eterm erts_sint64_to_big(Sint64 x, Eterm **hpp)
     return make_big(hp);
 }
 
+Eterm
+erts_uint64_array_to_big(Uint **hpp, int neg, int len, Uint64 *array)
+{
+    Uint *headerp;
+    int i, pot_digits, digits;
+
+    headerp = *hpp;
+
+    pot_digits = digits = 0;
+    for (i = 0; i < len; i++) {
+#if defined(ARCH_32) || HALFWORD_HEAP
+	Uint low_val = array[i] & ((Uint) 0xffffffff);
+	Uint high_val = (array[i] >> 32) & ((Uint) 0xffffffff);
+	BIG_DIGIT(headerp, pot_digits) = low_val;
+	pot_digits++;
+	if (low_val)
+	    digits = pot_digits;
+	BIG_DIGIT(headerp, pot_digits) = high_val;
+	pot_digits++;
+	if (high_val)
+	    digits = pot_digits;
+#else
+	Uint val = array[i];
+	BIG_DIGIT(headerp, pot_digits) = val;
+	pot_digits++;
+	if (val)
+	    digits = pot_digits;
+#endif
+    }	
+
+    if (neg)
+	*headerp = make_neg_bignum_header(digits);
+    else
+	*headerp = make_pos_bignum_header(digits);
+
+    *hpp = headerp + 1 + digits;
+
+    return make_big(headerp);
+}
+
 /*
 ** Convert a bignum to a double float
 */
diff --git a/erts/emulator/beam/big.h b/erts/emulator/beam/big.h
index da31876d75..4e4611de16 100644
--- a/erts/emulator/beam/big.h
+++ b/erts/emulator/beam/big.h
@@ -104,6 +104,9 @@ typedef Uint  dsize_t;	 /* Vector size type */
    : ERTS_UINT64_BIG_HEAP_SIZE__((X) >= 0 ? (X) : -(Uint64)(X)))
 #define ERTS_UINT64_HEAP_SIZE(X)				\
   (IS_USMALL(0, (X)) ? 0 : ERTS_UINT64_BIG_HEAP_SIZE__((X)))
+#define ERTS_MAX_SINT64_HEAP_SIZE (1 + 2)
+#define ERTS_MAX_UINT64_HEAP_SIZE (1 + 2)
+#define ERTS_UINT64_ARRAY_TO_BIG_MAX_HEAP_SZ(LEN) (2*(LEN)+1)
 
 #else
 
@@ -111,6 +114,9 @@ typedef Uint  dsize_t;	 /* Vector size type */
   (IS_SSMALL((X)) ? 0 : (1 + 1))
 #define ERTS_UINT64_HEAP_SIZE(X)				\
   (IS_USMALL(0, (X)) ? 0 : (1 + 1))
+#define ERTS_MAX_SINT64_HEAP_SIZE (1 + 1)
+#define ERTS_MAX_UINT64_HEAP_SIZE (1 + 1)
+#define ERTS_UINT64_ARRAY_TO_BIG_MAX_HEAP_SZ(LEN) ((LEN)+1)
 
 #endif
 
@@ -156,6 +162,7 @@ int term_to_Uint(Eterm, Uint*);
 int term_to_UWord(Eterm, UWord*);
 int term_to_Sint(Eterm, Sint*);
 #if HAVE_INT64
+Eterm erts_uint64_array_to_big(Uint **, int, int, Uint64 *);
 int term_to_Uint64(Eterm, Uint64*);
 int term_to_Sint64(Eterm, Sint64*);
 #endif
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
index 61def65235..e2f8da38b9 100644
--- a/erts/emulator/beam/erl_alloc.types
+++ b/erts/emulator/beam/erl_alloc.types
@@ -269,6 +269,7 @@ type    BUSY_CALLER_TAB	SHORT_LIVED	SYSTEM		busy_caller_table
 type    BUSY_CALLER	SHORT_LIVED	SYSTEM		busy_caller
 type	PROC_SYS_TSK	SHORT_LIVED	PROCESSES	proc_sys_task
 type	PROC_SYS_TSK_QS	SHORT_LIVED	PROCESSES	proc_sys_task_queues
+type    NEW_TIME_OFFSET	SHORT_LIVED	SYSTEM		new_time_offset
 
 +if threads_no_smp
 # Need thread safe allocs, but std_alloc and fix_alloc are not;
@@ -364,6 +365,7 @@ type	AINFO_REQ	STANDARD_LOW	SYSTEM		alloc_info_request
 type	SCHED_WTIME_REQ	STANDARD_LOW	SYSTEM		sched_wall_time_request
 type	GC_INFO_REQ	STANDARD_LOW	SYSTEM		gc_info_request
 type	PORT_DATA_HEAP	STANDARD_LOW	SYSTEM		port_data_heap
+type	BIF_TIMER_DATA	LONG_LIVED_LOW	SYSTEM		bif_timer_data
 
 +else # "fullword"
 
@@ -384,6 +386,7 @@ type	AINFO_REQ	SHORT_LIVED	SYSTEM		alloc_info_request
 type	SCHED_WTIME_REQ	SHORT_LIVED	SYSTEM		sched_wall_time_request
 type	GC_INFO_REQ	SHORT_LIVED	SYSTEM		gc_info_request
 type	PORT_DATA_HEAP	STANDARD	SYSTEM		port_data_heap
+type	BIF_TIMER_DATA	LONG_LIVED	SYSTEM		bif_timer_data
 
 +endif
 
diff --git a/erts/emulator/beam/erl_bif_binary.c b/erts/emulator/beam/erl_bif_binary.c
index bd0d7c71cc..934904d58e 100644
--- a/erts/emulator/beam/erl_bif_binary.c
+++ b/erts/emulator/beam/erl_bif_binary.c
@@ -38,6 +38,7 @@
 #include "big.h"
 #include "erl_binary.h"
 #include "erl_bits.h"
+#include "erl_bif_unique.h"
 
 
 /*
diff --git a/erts/emulator/beam/erl_bif_ddll.c b/erts/emulator/beam/erl_bif_ddll.c
index 56cd2ba04f..fc4f819f56 100644
--- a/erts/emulator/beam/erl_bif_ddll.c
+++ b/erts/emulator/beam/erl_bif_ddll.c
@@ -45,6 +45,7 @@
 #include "big.h"
 #include "dist.h"
 #include "erl_version.h"
+#include "erl_bif_unique.h"
 #include "dtrace-wrapper.h"
 
 #ifdef ERTS_SMP
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index d750e34be3..a1e26328c8 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -42,6 +42,7 @@
 #include "erl_cpu_topology.h"
 #include "erl_async.h"
 #include "erl_thr_progress.h"
+#include "erl_bif_unique.h"
 #define ERTS_PTAB_WANT_DEBUG_FUNCS__
 #include "erl_ptab.h"
 #ifdef HIPE
@@ -540,6 +541,7 @@ pi_locks(Eterm info)
     switch (info) {
     case am_status:
     case am_priority:
+    case am_trap_exit:
 	return ERTS_PROC_LOCK_STATUS;
     case am_links:
     case am_monitors:
@@ -592,7 +594,7 @@ static Eterm pi_args[] = {
     am_min_bin_vheap_size,
     am_current_location,
     am_current_stacktrace,
-};    
+};
 
 #define ERTS_PI_ARGS ((int) (sizeof(pi_args)/sizeof(Eterm)))
 
@@ -2102,6 +2104,46 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	BIF_RET(am_opt);
 #endif
 	BIF_RET(res);
+    } else if (BIF_ARG_1 == am_time_offset) {
+	switch (erts_time_offset_state()) {
+	case ERTS_TIME_OFFSET_PRELIMINARY: {
+	    ERTS_DECL_AM(preliminary);
+	    BIF_RET(AM_preliminary);
+	}
+	case ERTS_TIME_OFFSET_FINAL: {
+	    ERTS_DECL_AM(final);
+	    BIF_RET(AM_final);
+	}
+	case ERTS_TIME_OFFSET_VOLATILE: {
+	    ERTS_DECL_AM(volatile);
+	    BIF_RET(AM_volatile);
+	}
+	default:
+	    ERTS_INTERNAL_ERROR("Invalid time offset state");
+	}
+    } else if (ERTS_IS_ATOM_STR("os_monotonic_time_source", BIF_ARG_1)) {
+	BIF_RET(erts_monotonic_time_source(BIF_P));
+    } else if (ERTS_IS_ATOM_STR("time_correction", BIF_ARG_1)) {
+	BIF_RET(erts_has_time_correction() ? am_true : am_false);
+    } else if (ERTS_IS_ATOM_STR("start_time", BIF_ARG_1)) {
+	BIF_RET(erts_get_monotonic_start_time(BIF_P));
+    } else if (ERTS_IS_ATOM_STR("time_warp_mode", BIF_ARG_1)) {
+	switch (erts_time_warp_mode()) {
+	case ERTS_NO_TIME_WARP_MODE: {
+	    ERTS_DECL_AM(no_time_warp);
+	    BIF_RET(AM_no_time_warp);
+	}
+	case ERTS_SINGLE_TIME_WARP_MODE: {
+	    ERTS_DECL_AM(single_time_warp);
+	    BIF_RET(AM_single_time_warp);
+	}
+	case ERTS_MULTI_TIME_WARP_MODE: {
+	    ERTS_DECL_AM(multi_time_warp);
+	    BIF_RET(AM_multi_time_warp);
+	}
+	default:
+	    ERTS_INTERNAL_ERROR("Invalid time warp mode");
+	}
     } else if (BIF_ARG_1 == am_allocated_areas) {
 	res = erts_allocated_areas(NULL, NULL, BIF_P);
 	BIF_RET(res);
@@ -2703,9 +2745,11 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
         BIF_RET(make_small(erts_db_get_max_tabs()));
     }
     else if (ERTS_IS_ATOM_STR("tolerant_timeofday",BIF_ARG_1)) {
-	BIF_RET(erts_disable_tolerant_timeofday
-		? am_disabled
-		: am_enabled);
+	if (erts_has_time_correction()
+	    && erts_time_offset_state() == ERTS_TIME_OFFSET_FINAL) {
+	    BIF_RET(am_enabled);
+	}
+	BIF_RET(am_disabled);
     }
     else if (ERTS_IS_ATOM_STR("eager_check_io",BIF_ARG_1)) {
 	BIF_RET(erts_eager_check_io ? am_true : am_false);
@@ -3403,6 +3447,29 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
         else if (ERTS_IS_ATOM_STR("mmap", BIF_ARG_1)) {
             BIF_RET(erts_mmap_debug_info(BIF_P));
         }
+	else if (ERTS_IS_ATOM_STR("unique_monotonic_integer_state", BIF_ARG_1)) {
+	    BIF_RET(erts_debug_get_unique_monotonic_integer_state(BIF_P));
+	}
+	else if (ERTS_IS_ATOM_STR("min_unique_monotonic_integer", BIF_ARG_1)) {
+	    Sint64 value = erts_get_min_unique_monotonic_integer();
+	    if (IS_SSMALL(value))
+		BIF_RET(make_small(value));
+	    else {
+		Uint hsz = ERTS_SINT64_HEAP_SIZE(value);
+		Eterm *hp = HAlloc(BIF_P, hsz);
+		BIF_RET(erts_sint64_to_big(value, &hp));
+	    }
+	}
+	else if (ERTS_IS_ATOM_STR("min_unique_integer", BIF_ARG_1)) {
+	    Sint64 value = erts_get_min_unique_integer();
+	    if (IS_SSMALL(value))
+		BIF_RET(make_small(value));
+	    else {
+		Uint hsz = ERTS_SINT64_HEAP_SIZE(value);
+		Eterm *hp = HAlloc(BIF_P, hsz);
+		BIF_RET(erts_sint64_to_big(value, &hp));
+	    }
+	}
     }
     else if (is_tuple(BIF_ARG_1)) {
 	Eterm* tp = tuple_val(BIF_ARG_1);
@@ -3599,6 +3666,38 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 	    }
 	    break;
 	}
+	case 3: {
+	    if (ERTS_IS_ATOM_STR("check_time_config", tp[1])) {
+		int res, time_correction;
+		ErtsTimeWarpMode time_warp_mode;
+		if (tp[2] == am_true)
+		    time_correction = !0;
+		else if (tp[2] == am_false)
+		    time_correction = 0;
+		else
+		    break;
+		if (ERTS_IS_ATOM_STR("no_time_warp", tp[3]))
+		    time_warp_mode = ERTS_NO_TIME_WARP_MODE;
+		else if (ERTS_IS_ATOM_STR("single_time_warp", tp[3]))
+		    time_warp_mode = ERTS_SINGLE_TIME_WARP_MODE;
+		else if (ERTS_IS_ATOM_STR("multi_time_warp", tp[3]))
+		    time_warp_mode = ERTS_MULTI_TIME_WARP_MODE;
+		else
+		    break;
+		res = erts_check_time_adj_support(time_correction,
+						  time_warp_mode);
+		BIF_RET(res ? am_true : am_false);
+	    }
+	    else if (ERTS_IS_ATOM_STR("make_unique_integer", tp[1])) {
+	      Eterm res = erts_debug_make_unique_integer(BIF_P,
+							 tp[2],
+							 tp[3]);
+	      if (is_non_value(res))
+		  break;
+	      BIF_RET(res);
+	    }
+	    break;
+	}
 	default:
 	    break;
 	}
@@ -3606,6 +3705,24 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
     BIF_ERROR(BIF_P, BADARG);
 }
 
+BIF_RETTYPE erts_internal_is_system_process_1(BIF_ALIST_1)
+{
+    if (is_internal_pid(BIF_ARG_1)) {
+	Process *rp = erts_proc_lookup(BIF_ARG_1);
+	if (rp && (rp->static_flags & ERTS_STC_FLG_SYSTEM_PROC))
+	    BIF_RET(am_true);
+	BIF_RET(am_false);
+    }
+
+    if (is_external_pid(BIF_ARG_1)
+	&& external_pid_dist_entry(BIF_ARG_1) == erts_this_dist_entry) {
+	BIF_RET(am_false);
+    }
+
+    BIF_ERROR(BIF_P, BADARG);
+}
+
+
 static erts_smp_atomic_t hipe_test_reschedule_flag;
 
 
@@ -3907,6 +4024,10 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
 #endif
             erl_exit(ERTS_DUMP_EXIT, "%T", BIF_ARG_2);
         }
+	else if (ERTS_IS_ATOM_STR("unique_monotonic_integer_state", BIF_ARG_1)) {
+	    int res = erts_debug_set_unique_monotonic_integer_state(BIF_ARG_2);
+	    BIF_RET(res ? am_true : am_false);
+	}
     }
 
     BIF_ERROR(BIF_P, BADARG);
diff --git a/erts/emulator/beam/erl_bif_timer.c b/erts/emulator/beam/erl_bif_timer.c
index 03ac97283c..0bd8d20c34 100644
--- a/erts/emulator/beam/erl_bif_timer.c
+++ b/erts/emulator/beam/erl_bif_timer.c
@@ -27,6 +27,7 @@
 #include "error.h"
 #include "big.h"
 #include "erl_thr_progress.h"
+#include "erl_bif_unique.h"
 
 /****************************************************************************
 ** BIF Timer support
@@ -480,7 +481,7 @@ setup_bif_timer(Uint32 xflags,
 
     tab_insert(btm);
     ASSERT(btm == tab_find(ref));
-    btm->tm.active = 0; /* MUST be initalized */
+    erts_init_timer(&btm->tm);
     erts_set_timer(&btm->tm,
 		  (ErlTimeoutProc) bif_timer_timeout,
 		  (ErlCancelProc) bif_timer_cleanup,
@@ -489,8 +490,9 @@ setup_bif_timer(Uint32 xflags,
     return ref;
 }
 
+BIF_RETTYPE old_send_after_3(BIF_ALIST_3);
 /* send_after(Time, Pid, Message) -> Ref */
-BIF_RETTYPE send_after_3(BIF_ALIST_3)
+BIF_RETTYPE old_send_after_3(BIF_ALIST_3)
 {
     Eterm res;
 
@@ -510,8 +512,9 @@ BIF_RETTYPE send_after_3(BIF_ALIST_3)
     }
 }
 
+BIF_RETTYPE old_start_timer_3(BIF_ALIST_3);
 /* start_timer(Time, Pid, Message) -> Ref */
-BIF_RETTYPE start_timer_3(BIF_ALIST_3)
+BIF_RETTYPE old_start_timer_3(BIF_ALIST_3)
 {
     Eterm res;
 
@@ -531,8 +534,9 @@ BIF_RETTYPE start_timer_3(BIF_ALIST_3)
     }
 }
 
+BIF_RETTYPE old_cancel_timer_1(BIF_ALIST_1);
 /* cancel_timer(Ref) -> false | RemainingTime */
-BIF_RETTYPE cancel_timer_1(BIF_ALIST_1)
+BIF_RETTYPE old_cancel_timer_1(BIF_ALIST_1)
 {
     Eterm res;
     ErtsBifTimer *btm;
@@ -569,8 +573,9 @@ BIF_RETTYPE cancel_timer_1(BIF_ALIST_1)
     BIF_RET(res);
 }
 
+BIF_RETTYPE old_read_timer_1(BIF_ALIST_1);
 /* read_timer(Ref) -> false | RemainingTime */
-BIF_RETTYPE read_timer_1(BIF_ALIST_1)
+BIF_RETTYPE old_read_timer_1(BIF_ALIST_1)
 {
     Eterm res;
     ErtsBifTimer *btm;
@@ -652,7 +657,7 @@ erts_cancel_bif_timers(Process *p, ErtsProcLocks plocks)
     erts_smp_btm_rwunlock();
 }
 
-void erts_bif_timer_init(void)
+static void erts_old_bif_timer_init(void)
 {
     int i;
     no_bif_timers = 0;
@@ -703,3 +708,146 @@ erts_bif_timer_foreach(void (*func)(Eterm, Eterm, ErlHeapFragment *, void *),
 	}
     }
 }
+
+typedef struct {
+    Uint ref_heap[REF_THING_SIZE];
+    Eterm pid[1];
+} ErtsBifTimerServers;
+
+static ErtsBifTimerServers *bif_timer_servers;
+
+void erts_bif_timer_init(void)
+{
+    erts_old_bif_timer_init();
+}
+
+void
+erts_bif_timer_start_servers(Eterm parent)
+{
+    Process *parent_proc;
+    Eterm *hp, btr_ref, arg_list_end;
+    ErlSpawnOpts so;
+    int i;
+
+    bif_timer_servers = erts_alloc(ERTS_ALC_T_BIF_TIMER_DATA,
+				   (sizeof(ErtsBifTimerServers)
+				    + (sizeof(Eterm)*(erts_no_schedulers-1))));
+
+    so.flags = SPO_USE_ARGS|SPO_SYSTEM_PROC|SPO_PREFER_SCHED|SPO_OFF_HEAP_MSGS;
+    so.min_heap_size  = H_MIN_SIZE;
+    so.min_vheap_size = BIN_VH_MIN_SIZE;
+    so.priority       = PRIORITY_MAX;
+    so.max_gen_gcs    = (Uint16) erts_smp_atomic32_read_nob(&erts_max_gen_gcs);
+
+    /*
+     * Parent is "init" and schedulers have not yet been started, so it
+     * *should* be alive and well...
+     */
+    ASSERT(is_internal_pid(parent));
+    parent_proc = (Process *) erts_ptab_pix2intptr_ddrb(&erts_proc,
+							internal_pid_index(parent));
+    ASSERT(parent_proc);
+    ASSERT(parent_proc->common.id == parent);
+    ASSERT(!ERTS_PROC_IS_EXITING(parent_proc));
+
+    erts_smp_proc_lock(parent_proc, ERTS_PROC_LOCK_MAIN);
+
+    hp = HAlloc(parent_proc, 2*erts_no_schedulers + 2 + REF_THING_SIZE);
+
+    btr_ref = erts_make_ref_in_buffer(hp);
+    hp += REF_THING_SIZE;
+
+    arg_list_end = CONS(hp, btr_ref, NIL);
+    hp += 2;
+
+    for (i = 0; i < erts_no_schedulers; i++) {
+	int sched = i+1;
+	Eterm arg_list = CONS(hp, make_small(i+1), arg_list_end);
+	hp += 2;
+
+	so.scheduler = sched; /* Preferred scheduler */
+
+	bif_timer_servers->pid[i] = erl_create_process(parent_proc,
+						       am_erts_internal,
+						       am_bif_timer_server,
+						       arg_list,
+						       &so);
+    }
+
+    erts_smp_proc_unlock(parent_proc, ERTS_PROC_LOCK_MAIN);
+
+    hp = internal_ref_val(btr_ref);
+    for (i = 0; i < REF_THING_SIZE; i++)
+	bif_timer_servers->ref_heap[i] = hp[i];
+}
+
+BIF_RETTYPE
+erts_internal_get_bif_timer_servers_0(BIF_ALIST_0)
+{
+    int i;
+    Eterm *hp, res = NIL;
+
+    hp = HAlloc(BIF_P, erts_no_schedulers*2);
+    for (i = erts_no_schedulers-1; i >= 0; i--) {
+	res = CONS(hp, bif_timer_servers->pid[i], res);
+	hp += 2;
+    }
+    BIF_RET(res);
+}
+
+BIF_RETTYPE
+erts_internal_access_bif_timer_1(BIF_ALIST_1)
+{
+    int ix;
+    Uint32 *rdp;
+    Eterm ref, pid, *hp, res;
+
+    if (is_not_internal_ref(BIF_ARG_1)) {
+	if (is_not_ref(BIF_ARG_1))
+	    BIF_ERROR(BIF_P, BADARG);
+	BIF_RET(am_undefined);
+    }
+
+    rdp = internal_ref_numbers(BIF_ARG_1);
+    ix = (int) erts_get_ref_numbers_thr_id(rdp);
+    if (ix < 1 || erts_no_schedulers < ix)
+	BIF_RET(am_undefined);
+
+    pid = bif_timer_servers->pid[ix-1];
+    ASSERT(is_internal_pid(pid));
+
+    hp = HAlloc(BIF_P, 3 /* 2-tuple */ + REF_THING_SIZE);
+    for (ix = 0; ix < REF_THING_SIZE; ix++)
+	hp[ix] = bif_timer_servers->ref_heap[ix];
+    ref = make_internal_ref(&hp[0]);
+    hp += REF_THING_SIZE;
+
+    res = TUPLE2(hp, ref, pid);
+    BIF_RET(res);
+}
+
+BIF_RETTYPE
+erts_internal_create_bif_timer_0(BIF_ALIST_0)
+{
+    ErtsSchedulerData *esdp = ERTS_PROC_GET_SCHDATA(BIF_P);
+    Eterm *hp, btr_ref, t_ref, pid, res;
+    int ix;
+
+    hp = HAlloc(BIF_P, 4 /* 3-tuple */ + 2*REF_THING_SIZE);
+    for (ix = 0; ix < REF_THING_SIZE; ix++)
+	hp[ix] = bif_timer_servers->ref_heap[ix];
+    btr_ref = make_internal_ref(&hp[0]);
+    hp += REF_THING_SIZE;
+
+    t_ref = erts_sched_make_ref_in_buffer(esdp, hp);
+    hp += REF_THING_SIZE;
+
+    ASSERT(erts_get_ref_numbers_thr_id(internal_ref_numbers(t_ref))
+	   == (Uint32) esdp->no);
+
+    pid = bif_timer_servers->pid[((int) esdp->no) - 1];
+    
+    res = TUPLE3(hp, btr_ref, pid, t_ref);
+
+    BIF_RET(res);
+}
diff --git a/erts/emulator/beam/erl_bif_timer.h b/erts/emulator/beam/erl_bif_timer.h
index 1197c176f5..c2f5dfd3c3 100644
--- a/erts/emulator/beam/erl_bif_timer.h
+++ b/erts/emulator/beam/erl_bif_timer.h
@@ -33,4 +33,5 @@ void erts_cancel_bif_timers(Process *p, ErtsProcLocks plocks);
 void erts_bif_timer_init(void);
 void erts_bif_timer_foreach(void (*func)(Eterm,Eterm,ErlHeapFragment *,void *),
 			    void *arg);
+void erts_bif_timer_start_servers(Eterm);
 #endif
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index f5e582b1c5..ac57205c47 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -38,6 +38,7 @@
 #include "beam_bp.h"
 #include "erl_binary.h"
 #include "erl_thr_progress.h"
+#include "erl_bif_unique.h"
 
 #define DECL_AM(S) Eterm AM_ ## S = am_atom_put(#S, sizeof(#S) - 1)
 
diff --git a/erts/emulator/beam/erl_bif_unique.c b/erts/emulator/beam/erl_bif_unique.c
new file mode 100644
index 0000000000..57b0bab72f
--- /dev/null
+++ b/erts/emulator/beam/erl_bif_unique.c
@@ -0,0 +1,556 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2014. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include "sys.h"
+#include "erl_vm.h"
+#include "erl_alloc.h"
+#include "export.h"
+#include "bif.h"
+#include "erl_bif_unique.h"
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * Reference                                                         *
+\*                                                                   */
+
+static union {
+    erts_atomic64_t count;
+    char align__[ERTS_CACHE_LINE_SIZE];
+} global_reference erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+
+/*
+ * ref[0] indicate thread creating reference as follows:
+ *
+ * - ref[0] == 0 => Non-scheduler thread;
+ * - else; ref[0] <= erts_no_schedulers =>
+ *      ordinary scheduler with id == ref[0];
+ * - else; ref[0] <= erts_no_schedulers
+ *                   + erts_no_dirty_cpu_schedulers =>
+ *      dirty cpu scheduler with id == 'ref[0] - erts_no_schedulers';
+ * - else =>
+ *      dirty io scheduler with id == 'ref[0]
+ *                                     - erts_no_schedulers
+ *                                     - erts_no_dirty_cpu_schedulers'
+ */
+
+#ifdef DEBUG
+static Uint32 max_thr_id;
+#endif
+
+static void
+init_reference(void)
+{
+#ifdef DEBUG
+    max_thr_id = (Uint32) erts_no_schedulers;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    max_thr_id += (Uint32) erts_no_dirty_cpu_schedulers;
+    max_thr_id += (Uint32) erts_no_dirty_io_schedulers;
+#endif
+#endif
+    erts_atomic64_init_nob(&global_reference.count, 0);
+}
+
+static ERTS_INLINE void
+global_make_ref_in_array(Uint32 thr_id, Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    Uint64 value;
+
+    value = (Uint64) erts_atomic64_inc_read_mb(&global_reference.count);
+    
+    erts_set_ref_numbers(ref, thr_id, value);
+}
+
+static ERTS_INLINE void
+make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    if (esdp)
+	erts_sched_make_ref_in_array(esdp, ref);
+    else
+	global_make_ref_in_array(0, ref);
+}
+
+void
+erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    make_ref_in_array(ref);
+}
+
+Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE])
+{
+    Eterm* hp = buffer;
+    Uint32 ref[ERTS_MAX_REF_NUMBERS];
+
+    make_ref_in_array(ref);
+    write_ref_thing(hp, ref[0], ref[1], ref[2]);
+    return make_internal_ref(hp);
+}
+
+Eterm erts_make_ref(Process *c_p)
+{
+    Eterm* hp;
+    Uint32 ref[ERTS_MAX_REF_NUMBERS];
+
+    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(c_p));
+
+    hp = HAlloc(c_p, REF_THING_SIZE);
+
+    make_ref_in_array(ref);
+    write_ref_thing(hp, ref[0], ref[1], ref[2]);
+
+    return make_internal_ref(hp);
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * Unique Integer                                                    *
+\*                                                                   */
+
+static struct {
+    union {
+	struct {
+	    int left_shift;
+	    int right_shift;
+	    Uint64 mask;
+	    Uint64 val0_max;
+	} o;
+	char align__[ERTS_CACHE_LINE_SIZE];
+    } r;
+    union {
+	erts_atomic64_t val1;
+	char align__[ERTS_CACHE_LINE_SIZE];
+    } w;
+} unique_data erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+static void
+init_unique_integer(void)
+{
+    int bits;
+    unique_data.r.o.val0_max = (Uint64) erts_no_schedulers;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    unique_data.r.o.val0_max += (Uint64) erts_no_dirty_cpu_schedulers;
+    unique_data.r.o.val0_max += (Uint64) erts_no_dirty_io_schedulers;
+#endif
+    bits = erts_fit_in_bits_int64(unique_data.r.o.val0_max);
+    unique_data.r.o.left_shift = bits;
+    unique_data.r.o.right_shift = 64 - bits;
+    unique_data.r.o.mask = (((Uint64) 1) << bits) - 1;
+    erts_atomic64_init_nob(&unique_data.w.val1, -1);
+}
+
+#define ERTS_MAX_UNIQUE_INT_HEAP_SIZE ERTS_UINT64_ARRAY_TO_BIG_MAX_HEAP_SZ(2)
+
+static ERTS_INLINE Eterm
+bld_unique_integer_term(Eterm **hpp, Uint *szp,
+			Uint64 val0, Uint64 val1,
+			int positive)
+{
+    Uint hsz;
+    Uint64 unique_val[2];
+
+    unique_val[0] = ((Uint64) val0);
+    unique_val[0] |= ((Uint64) val1) << unique_data.r.o.left_shift;
+    unique_val[1] = ((Uint64) val1) >> unique_data.r.o.right_shift;
+    unique_val[1] &= unique_data.r.o.mask;
+
+    if (positive) {
+	unique_val[0]++;
+	if (unique_val[0] == 0)
+	    unique_val[1]++;
+    }
+    else {
+	ASSERT(MIN_SMALL < 0);
+	if (unique_val[1] == 0
+	    && unique_val[0] < ((Uint64) -1*((Sint64) MIN_SMALL))) {
+	    Sint64 s_unique_val = (Sint64) unique_val[0];
+	    s_unique_val += MIN_SMALL;
+	    ASSERT(MIN_SMALL <= s_unique_val && s_unique_val < 0);
+	    if (szp)
+		*szp = 0;
+	    if (!hpp)
+		return THE_NON_VALUE;
+	    return make_small((Sint) s_unique_val);
+	}
+	if (unique_val[0] < ((Uint64) -1*((Sint64) MIN_SMALL))) {
+	    ASSERT(unique_val[1] != 0);
+	    unique_val[1] -= 1;
+	}
+	unique_val[0] += MIN_SMALL;
+    }
+
+    if (!unique_val[1]) {
+	if (unique_val[0] <= MAX_SMALL) {
+	    if (szp)
+		*szp = 0;
+	    if (!hpp)
+		return THE_NON_VALUE;
+	    return make_small((Uint) unique_val[0]);
+	}
+
+	if (szp)
+	    *szp = ERTS_UINT64_HEAP_SIZE(unique_val[0]);
+	if (!hpp)
+	    return THE_NON_VALUE;
+	return erts_uint64_to_big(unique_val[0], hpp);
+    }
+    else {
+	Eterm tmp, *tmp_hp, res;
+	DeclareTmpHeapNoproc(local_heap, 2*ERTS_MAX_UNIQUE_INT_HEAP_SIZE);
+
+	UseTmpHeapNoproc(2*ERTS_MAX_UNIQUE_INT_HEAP_SIZE);
+
+	tmp_hp = local_heap;
+
+	tmp = erts_uint64_array_to_big(&tmp_hp, 0, 2, unique_val);
+	ASSERT(is_big(tmp));
+
+	hsz = big_arity(tmp) + 1;
+
+	ASSERT(hsz <= ERTS_MAX_UNIQUE_INT_HEAP_SIZE);
+
+	if (szp)
+	    *szp = hsz;
+
+	if (!hpp)
+	    res = THE_NON_VALUE;
+	else {
+	    int hix;
+	    Eterm *hp = *hpp;
+	    tmp_hp = big_val(tmp);
+	    for (hix = 0; hix < hsz; hix++)
+		hp[hix] = tmp_hp[hix];
+
+	    *hpp = hp + hsz;
+	    res = make_big(hp);
+	}
+
+	UnUseTmpHeapNoproc(2*ERTS_MAX_UNIQUE_INT_HEAP_SIZE);
+
+	return res;
+    }
+}
+
+static ERTS_INLINE Eterm unique_integer_bif(Process *c_p, int positive)
+{
+    ErtsSchedulerData *esdp;
+    Uint64 thr_id, unique;
+    Uint hsz;
+    Eterm *hp;
+
+    esdp = ERTS_PROC_GET_SCHDATA(c_p);
+    thr_id = (Uint64) esdp->thr_id;
+    unique = esdp->unique++;
+    bld_unique_integer_term(NULL, &hsz, thr_id, unique, positive);
+    hp = hsz ? HAlloc(c_p, hsz) : NULL;
+    return bld_unique_integer_term(&hp, NULL, thr_id, unique, positive);
+}
+
+Uint
+erts_raw_unique_integer_heap_size(Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES])
+{
+    Uint sz;
+    bld_unique_integer_term(NULL, &sz, val[0], val[1], 0);
+    return sz;
+}
+
+Eterm
+erts_raw_make_unique_integer(Eterm **hpp, Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES])
+{
+    return bld_unique_integer_term(hpp, NULL, val[0], val[1], 0);
+}
+
+void
+erts_raw_get_unique_integer(Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES])
+{
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    if (esdp) {
+	val[0] = (Uint64) esdp->thr_id;
+	val[1] = esdp->unique++;
+    }
+    else {
+	val[0] = (Uint64) 0;
+	val[1] = (Uint64) erts_atomic64_inc_read_nob(&unique_data.w.val1);
+    }
+}
+
+
+Sint64
+erts_get_min_unique_integer(void)
+{
+    return (Sint64) MIN_SMALL;
+}
+
+/* --- Debug --- */
+
+Eterm
+erts_debug_make_unique_integer(Process *c_p, Eterm etval0, Eterm etval1)
+{
+    Uint64 val0, val1;
+    Uint hsz;
+    Eterm res, *hp, *end_hp;
+
+    if (!term_to_Uint64(etval0, &val0))
+	return THE_NON_VALUE;
+
+    if (!term_to_Uint64(etval1, &val1))
+	return THE_NON_VALUE;
+
+    bld_unique_integer_term(NULL, &hsz, val0, val1, 0);
+
+    hp = HAlloc(c_p, hsz);
+    end_hp = hp + hsz;
+
+    res = bld_unique_integer_term(&hp, NULL, val0, val1, 0);
+    if (hp != end_hp)
+	ERTS_INTERNAL_ERROR("Heap allocation error");
+
+    return res;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * Strict Monotonic Counter                                          *
+\*                                                                   */
+
+static struct {
+    union {
+	erts_atomic64_t value;
+	char align__[ERTS_CACHE_LINE_SIZE];
+    } w;
+} raw_unique_monotonic_integer erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+#if defined(ARCH_32) || HALFWORD_HEAP
+#  define ERTS_UNIQUE_MONOTONIC_OFFSET ERTS_SINT64_MIN
+#else
+#  define ERTS_UNIQUE_MONOTONIC_OFFSET MIN_SMALL
+#endif
+
+static void
+init_unique_monotonic_integer(void)
+{
+    erts_atomic64_init_nob(&raw_unique_monotonic_integer.w.value,
+			   (erts_aint64_t) -1);
+}
+
+static ERTS_INLINE Uint64
+get_raw_unique_monotonic_integer(void)
+{
+    return (Uint64) erts_atomic64_inc_read_mb(&raw_unique_monotonic_integer.w.value);
+}
+
+static ERTS_INLINE Uint
+get_unique_monotonic_integer_heap_size(Uint64 raw, int positive)
+{
+    if (positive) {
+	Uint64 value = raw+1;
+	return ERTS_UINT64_HEAP_SIZE(value);
+    }
+    else {
+	Sint64 value = ((Sint64) raw) + ERTS_UNIQUE_MONOTONIC_OFFSET;
+	if (IS_SSMALL(value))
+	    return 0;
+#if defined(ARCH_32) || HALFWORD_HEAP
+	return ERTS_SINT64_HEAP_SIZE(value);
+#else
+	return ERTS_UINT64_HEAP_SIZE((Uint64) value);
+#endif
+    }
+}
+
+static ERTS_INLINE Eterm
+make_unique_monotonic_integer_value(Eterm *hp, Uint hsz, Uint64 raw, int positive)
+{
+    Eterm res;
+#ifdef DEBUG
+    Eterm *end_hp = hp + hsz;
+#endif
+
+    if (positive) {
+	Uint64 value = raw+1;
+	res = hsz ? erts_uint64_to_big(value, &hp) : make_small(value);
+    }
+    else {
+	Sint64 value = ((Sint64) raw) + ERTS_UNIQUE_MONOTONIC_OFFSET;
+	if (hsz == 0)
+	    res = make_small(value);
+	else {
+#if defined(ARCH_32) || HALFWORD_HEAP
+	    res = erts_sint64_to_big(value, &hp);
+#else 
+	    res = erts_uint64_to_big((Uint64) value, &hp);
+#endif
+	}
+    }
+
+    ASSERT(end_hp == hp);
+
+    return res;
+}
+
+static ERTS_INLINE Eterm
+unique_monotonic_integer_bif(Process *c_p, int positive)
+{
+    Uint64 raw;
+    Uint hsz;
+    Eterm *hp;
+
+    raw = get_raw_unique_monotonic_integer();
+    hsz = get_unique_monotonic_integer_heap_size(raw, positive);
+    hp = hsz ? HAlloc(c_p, hsz) : NULL;
+    return make_unique_monotonic_integer_value(hp, hsz, raw, positive);
+}
+
+Sint64
+erts_raw_get_unique_monotonic_integer(void)
+{
+    return get_raw_unique_monotonic_integer();
+}
+
+Uint
+erts_raw_unique_monotonic_integer_heap_size(Sint64 raw)
+{
+    return get_unique_monotonic_integer_heap_size(raw, 0);
+}
+
+Eterm
+erts_raw_make_unique_monotonic_integer_value(Eterm **hpp, Sint64 raw)
+{
+    Uint hsz = get_unique_monotonic_integer_heap_size(raw, 0);
+    Eterm res = make_unique_monotonic_integer_value(*hpp, hsz, raw, 0);
+    *hpp += hsz;
+    return res;
+}
+
+Sint64
+erts_get_min_unique_monotonic_integer(void)
+{
+    return ERTS_UNIQUE_MONOTONIC_OFFSET;
+}
+
+/* --- Debug --- */
+
+int
+erts_debug_set_unique_monotonic_integer_state(Eterm et_value)
+{
+    Sint64 value;
+
+    if (!term_to_Sint64(et_value, &value)) {
+	Uint64 uvalue;
+	if (!term_to_Uint64(et_value, &uvalue))
+	    return 0;
+	value = (Sint64) uvalue;
+    }
+
+    erts_atomic64_set_mb(&raw_unique_monotonic_integer.w.value,
+			 (erts_aint64_t) value);
+    return 1;
+}
+
+Eterm
+erts_debug_get_unique_monotonic_integer_state(Process *c_p)
+{
+    Uint64 value;
+    Eterm hsz, *hp;
+
+    value = (Uint64) erts_atomic64_read_mb(&raw_unique_monotonic_integer.w.value);
+
+    if (IS_USMALL(0, value))
+	return make_small(value);
+    hsz = ERTS_UINT64_HEAP_SIZE(value);
+    hp = HAlloc(c_p, hsz);
+    return erts_uint64_to_big(value, &hp);
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * Initilazation                                                     *
+\*                                                                   */
+
+void
+erts_bif_unique_init(void)
+{
+    init_reference();
+    init_unique_monotonic_integer();
+    init_unique_integer();
+}
+
+void
+erts_sched_bif_unique_init(ErtsSchedulerData *esdp)
+{
+    esdp->unique = (Uint64) 0;
+    esdp->ref = (Uint64) 0;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * The BIFs                                                          *
+\*                                                                   */
+
+
+BIF_RETTYPE make_ref_0(BIF_ALIST_0)
+{
+    BIF_RETTYPE res;
+    Eterm* hp;
+
+    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(BIF_P));
+
+    hp = HAlloc(BIF_P, REF_THING_SIZE);
+
+    res = erts_sched_make_ref_in_buffer(ERTS_PROC_GET_SCHDATA(BIF_P), hp);
+
+    BIF_RET(res);
+}
+
+BIF_RETTYPE unique_integer_0(BIF_ALIST_0)
+{
+    BIF_RET(unique_integer_bif(BIF_P, 0));
+}
+
+BIF_RETTYPE unique_integer_1(BIF_ALIST_1)
+{
+    Eterm modlist = BIF_ARG_1;
+    int monotonic = 0;
+    int positive = 0;
+    BIF_RETTYPE res;
+
+    while (is_list(modlist)) {
+	Eterm *consp = list_val(modlist);
+	switch (CAR(consp)) {
+	case am_monotonic:
+	    monotonic = 1;
+	    break;
+	case am_positive:
+	    positive = 1;
+	    break;
+	default:
+	    BIF_ERROR(BIF_P, BADARG);
+	}
+	modlist = CDR(consp);
+    }
+
+    if (is_not_nil(modlist))
+	BIF_ERROR(BIF_P, BADARG);
+
+    if (monotonic)
+	res = unique_monotonic_integer_bif(BIF_P, positive);
+    else
+	res = unique_integer_bif(BIF_P, positive);
+
+    BIF_RET(res);
+}
diff --git a/erts/emulator/beam/erl_bif_unique.h b/erts/emulator/beam/erl_bif_unique.h
new file mode 100644
index 0000000000..cd001172a1
--- /dev/null
+++ b/erts/emulator/beam/erl_bif_unique.h
@@ -0,0 +1,131 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2014. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifndef ERTS_BIF_UNIQUE_H__
+#define ERTS_BIF_UNIQUE_H__
+
+#include "erl_process.h"
+#include "big.h"
+
+void erts_bif_unique_init(void);
+void erts_sched_bif_unique_init(ErtsSchedulerData *esdp);
+
+/* reference */
+Eterm erts_make_ref(Process *);
+Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE]);
+void erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+
+/* strict monotonic counter */
+
+#define ERTS_MAX_UNIQUE_MONOTONIC_INTEGER_HEAP_SIZE ERTS_MAX_UINT64_HEAP_SIZE
+
+/*
+ * Note that a raw value is an intermediate value that 
+ * not necessarily correspond to the end result.
+ */
+Sint64 erts_raw_get_unique_monotonic_integer(void);
+Uint erts_raw_unique_monotonic_integer_heap_size(Sint64 raw);
+Eterm erts_raw_make_unique_monotonic_integer_value(Eterm **hpp, Sint64 raw);
+
+Sint64 erts_get_min_unique_monotonic_integer(void);
+
+int erts_debug_set_unique_monotonic_integer_state(Eterm et_value);
+Eterm erts_debug_get_unique_monotonic_integer_state(Process *c_p);
+
+/* unique integer */
+#define ERTS_UNIQUE_INT_RAW_VALUES 2
+#define ERTS_MAX_UNIQUE_INT_HEAP_SIZE ERTS_UINT64_ARRAY_TO_BIG_MAX_HEAP_SZ(2)
+
+Uint erts_raw_unique_integer_heap_size(Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES]);
+Eterm erts_raw_make_unique_integer(Eterm **hpp, Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES]);
+void erts_raw_get_unique_integer(Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES]);
+Sint64 erts_get_min_unique_integer(void);
+
+Eterm erts_debug_make_unique_integer(Process *c_p,
+				     Eterm etval0,
+				     Eterm etval1);
+
+
+ERTS_GLB_INLINE void erts_set_ref_numbers(Uint32 ref[ERTS_MAX_REF_NUMBERS],
+					  Uint32 thr_id, Uint64 value);
+ERTS_GLB_INLINE Uint32 erts_get_ref_numbers_thr_id(Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+ERTS_GLB_INLINE Uint64 erts_get_ref_numbers_value(Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+ERTS_GLB_INLINE void erts_sched_make_ref_in_array(ErtsSchedulerData *esdp,
+						  Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+ERTS_GLB_INLINE Eterm erts_sched_make_ref_in_buffer(ErtsSchedulerData *esdp,
+						    Eterm buffer[REF_THING_SIZE]);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE void
+erts_set_ref_numbers(Uint32 ref[ERTS_MAX_REF_NUMBERS], Uint32 thr_id, Uint64 value)
+{
+    /*
+     * We cannot use thread id in the first 18-bit word since
+     * the hash/phash/phash2 BIFs only hash on this word. If
+     * we did, we would get really poor hash values. Instead
+     * we have to shuffle the bits a bit.
+     */
+    ASSERT(thr_id == (thr_id & ((Uint32) 0x3ffff)));
+    ref[0] = (Uint32) (value & ((Uint64) 0x3ffff));
+    ref[1] = (((Uint32) (value & ((Uint64) 0xfffc0000)))
+	      | (thr_id & ((Uint32) 0x3ffff)));
+    ref[2] = (Uint32) ((value >> 32) & ((Uint64) 0xffffffff));
+}
+
+ERTS_GLB_INLINE Uint32
+erts_get_ref_numbers_thr_id(Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    return ref[1] & ((Uint32) 0x3ffff);
+}
+
+ERTS_GLB_INLINE Uint64
+erts_get_ref_numbers_value(Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    return (((((Uint64) ref[2]) & ((Uint64) 0xffffffff)) << 32)
+	    | (((Uint64) ref[1]) & ((Uint64) 0xfffc0000))
+	    | (((Uint64) ref[0]) & ((Uint64) 0x3ffff)));
+}
+
+ERTS_GLB_INLINE void
+erts_sched_make_ref_in_array(ErtsSchedulerData *esdp,
+			     Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    Uint64 value;
+
+    ASSERT(esdp);
+    value = esdp->ref++;
+    erts_set_ref_numbers(ref, (Uint32) esdp->thr_id, value);
+}
+
+ERTS_GLB_INLINE Eterm
+erts_sched_make_ref_in_buffer(ErtsSchedulerData *esdp,
+			      Eterm buffer[REF_THING_SIZE])
+{
+    Eterm* hp = buffer;
+    Uint32 ref[ERTS_MAX_REF_NUMBERS];
+
+    erts_sched_make_ref_in_array(esdp, ref);
+    write_ref_thing(hp, ref[0], ref[1], ref[2]);
+    return make_internal_ref(hp);
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#endif /*  ERTS_BIF_UNIQUE_H__ */
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index d1a7ee113b..4a116c0740 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -39,6 +39,7 @@
 #include "hipe_mode_switch.h"
 #endif
 #include "dtrace-wrapper.h"
+#include "erl_bif_unique.h"
 
 #define ERTS_INACT_WR_PB_LEAVE_MUCH_LIMIT 1
 #define ERTS_INACT_WR_PB_LEAVE_MUCH_PERCENTAGE 20
@@ -96,10 +97,10 @@ typedef struct {
 
 static Uint setup_rootset(Process*, Eterm*, int, Rootset*);
 static void cleanup_rootset(Rootset *rootset);
-static Uint combined_message_size(Process* p);
+static Uint combined_message_size(Process* p, int off_heap_msgs);
 static void remove_message_buffers(Process* p);
-static int major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl);
-static int minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl);
+static int major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl, int off_heap_msgs);
+static int minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl, int off_heap_msgs);
 static void do_minor(Process *p, Uint new_sz, Eterm* objv, int nobj);
 static Eterm* sweep_rootset(Rootset *rootset, Eterm* htop, char* src, Uint src_size);
 static Eterm* sweep_one_area(Eterm* n_hp, Eterm* n_htop, char* src, Uint src_size);
@@ -402,7 +403,9 @@ erts_garbage_collect(Process* p, int need, Eterm* objv, int nobj)
 {
     Uint reclaimed_now = 0;
     int done = 0;
+    int off_heap_msgs;
     Uint ms1, s1, us1;
+    erts_aint32_t state;
     ErtsSchedulerData *esdp;
 #ifdef USE_VM_PROBES
     DTRACE_CHARBUF(pidbuf, DTRACE_TERM_BUF_SIZE);
@@ -419,7 +422,8 @@ erts_garbage_collect(Process* p, int need, Eterm* objv, int nobj)
         trace_gc(p, am_gc_start);
     }
 
-    erts_smp_atomic32_read_bor_nob(&p->state, ERTS_PSFLG_GC);
+    state = erts_smp_atomic32_read_bor_nob(&p->state, ERTS_PSFLG_GC);
+    off_heap_msgs = state & ERTS_PSFLG_OFF_HEAP_MSGS;
     if (erts_system_monitor_long_gc != 0) {
 	get_now(&ms1, &s1, &us1);
     }
@@ -445,11 +449,11 @@ erts_garbage_collect(Process* p, int need, Eterm* objv, int nobj)
     while (!done) {
 	if ((FLAGS(p) & F_NEED_FULLSWEEP) != 0) {
 	    DTRACE2(gc_major_start, pidbuf, need);
-	    done = major_collection(p, need, objv, nobj, &reclaimed_now);
+	    done = major_collection(p, need, objv, nobj, &reclaimed_now, off_heap_msgs);
 	    DTRACE2(gc_major_end, pidbuf, reclaimed_now);
 	} else {
 	    DTRACE2(gc_minor_start, pidbuf, need);
-	    done = minor_collection(p, need, objv, nobj, &reclaimed_now);
+	    done = minor_collection(p, need, objv, nobj, &reclaimed_now, off_heap_msgs);
 	    DTRACE2(gc_minor_end, pidbuf, reclaimed_now);
 	}
     }
@@ -832,7 +836,7 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
 }
 
 static int
-minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
+minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl, int off_heap_msgs)
 {
     Uint mature = HIGH_WATER(p) - HEAP_START(p);
 
@@ -871,20 +875,22 @@ minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
 	Uint size_after;
 	Uint need_after;
 	Uint stack_size = STACK_SZ_ON_HEAP(p);
-	Uint fragments = MBUF_SIZE(p) + combined_message_size(p);
+	Uint fragments = MBUF_SIZE(p) + combined_message_size(p, off_heap_msgs);
 	Uint size_before = fragments + (HEAP_TOP(p) - HEAP_START(p));
 	Uint new_sz = next_heap_size(p, HEAP_SIZE(p) + fragments, 0);
 
         do_minor(p, new_sz, objv, nobj);
 
-	/*
-	 * Copy newly received message onto the end of the new heap.
-	 */
-	ErtsGcQuickSanityCheck(p);
-	for (msgp = p->msg.first; msgp; msgp = msgp->next) {
-	    if (msgp->data.attached) {
-		erts_move_msg_attached_data_to_heap(&p->htop, &p->off_heap, msgp);
-		ErtsGcQuickSanityCheck(p);
+	if (!off_heap_msgs) {
+	    /*
+	     * Copy newly received message onto the end of the new heap.
+	     */
+	    ErtsGcQuickSanityCheck(p);
+	    for (msgp = p->msg.first; msgp; msgp = msgp->next) {
+		if (msgp->data.attached) {
+		    erts_move_msg_attached_data_to_heap(&p->htop, &p->off_heap, msgp);
+		    ErtsGcQuickSanityCheck(p);
+		}
 	    }
 	}
 	ErtsGcQuickSanityCheck(p);
@@ -1210,7 +1216,7 @@ do_minor(Process *p, Uint new_sz, Eterm* objv, int nobj)
  */
 
 static int
-major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
+major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl, int off_heap_msgs)
 {
     Rootset rootset;
     Roots* roots;
@@ -1223,8 +1229,7 @@ major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
     Uint oh_size = (char *) OLD_HTOP(p) - oh;
     Uint n;
     Uint new_sz;
-    Uint fragments = MBUF_SIZE(p) + combined_message_size(p);
-    ErlMessage *msgp;
+    Uint fragments = MBUF_SIZE(p) + combined_message_size(p, off_heap_msgs);
 
     size_before = fragments + (HEAP_TOP(p) - HEAP_START(p));
 
@@ -1434,13 +1439,16 @@ major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
 
     ErtsGcQuickSanityCheck(p);
 
-    /*
-     * Copy newly received message onto the end of the new heap.
-     */
-    for (msgp = p->msg.first; msgp; msgp = msgp->next) {
-	if (msgp->data.attached) {
-	    erts_move_msg_attached_data_to_heap(&p->htop, &p->off_heap, msgp);
-	    ErtsGcQuickSanityCheck(p);
+    if (!off_heap_msgs) {
+	ErlMessage *msgp;
+	/*
+	 * Copy newly received message onto the end of the new heap.
+	 */
+	for (msgp = p->msg.first; msgp; msgp = msgp->next) {
+	    if (msgp->data.attached) {
+		erts_move_msg_attached_data_to_heap(&p->htop, &p->off_heap, msgp);
+		ErtsGcQuickSanityCheck(p);
+	    }
 	}
     }
 
@@ -1501,15 +1509,17 @@ adjust_after_fullsweep(Process *p, Uint size_before, int need, Eterm *objv, int
  * mbuf list.
  */
 static Uint
-combined_message_size(Process* p)
+combined_message_size(Process* p, int off_heap_msgs)
 {
-    Uint sz = 0;
+    Uint sz;
     ErlMessage *msgp;
 
-    for (msgp = p->msg.first; msgp; msgp = msgp->next) {
-	if (msgp->data.attached) {
+    if (off_heap_msgs)
+	return 0;
+
+    for (sz = 0, msgp = p->msg.first; msgp; msgp = msgp->next) {
+	if (msgp->data.attached)
 	    sz += erts_msg_attached_data_size(msgp);
-	}
     }
     return sz;
 }
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index fe065e196d..5aeb5b2590 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -45,6 +45,7 @@
 #include "erl_thr_queue.h"
 #include "erl_async.h"
 #include "erl_ptab.h"
+#include "erl_bif_unique.h"
 
 #ifdef HIPE
 #include "hipe_mode_switch.h"	/* for hipe_mode_switch_init() */
@@ -134,7 +135,9 @@ static void erl_init(int ncpu,
 		     int legacy_proc_tab,
 		     int port_tab_sz,
 		     int port_tab_sz_ignore_files,
-		     int legacy_port_tab);
+		     int legacy_port_tab,
+		     int time_correction,
+		     ErtsTimeWarpMode time_warp_mode);
 
 static erts_atomic_t exiting;
 
@@ -185,10 +188,6 @@ static int no_dirty_io_schedulers;
 Uint32 verbose;             /* See erl_debug.h for information about verbose */
 #endif
 
-int erts_disable_tolerant_timeofday; /* Time correction can be disabled it is
-				      * not and/or it is too slow.
-				      */
-
 int erts_atom_table_size = ATOM_LIMIT;	/* Maximum number of atoms */
 
 int erts_pd_initial_size = 10;
@@ -268,6 +267,19 @@ this_rel_num(void)
     return this_rel;
 }
 
+static ERTS_INLINE void
+set_default_time_adj(int *time_correction_p, ErtsTimeWarpMode *time_warp_mode_p)
+{
+    *time_correction_p = 1;
+    *time_warp_mode_p = ERTS_NO_TIME_WARP_MODE;
+    if (!erts_check_time_adj_support(*time_correction_p,
+				     *time_warp_mode_p)) {
+	*time_correction_p = 0;
+	ASSERT(erts_check_time_adj_support(*time_correction_p,
+					   *time_warp_mode_p));
+    }
+}
+
 /*
  * Common error printout function, all error messages
  * that don't go to the error logger go through here.
@@ -283,13 +295,22 @@ static int early_init(int *argc, char **argv);
 void
 erts_short_init(void)
 {
-    int ncpu = early_init(NULL, NULL);
+    
+    int ncpu;
+    int time_correction;
+    ErtsTimeWarpMode time_warp_mode;
+
+    set_default_time_adj(&time_correction,
+			 &time_warp_mode);
+    ncpu = early_init(NULL, NULL);
     erl_init(ncpu,
 	     ERTS_DEFAULT_MAX_PROCESSES,
 	     0,
 	     ERTS_DEFAULT_MAX_PORTS,
 	     0,
-	     0);
+	     0,
+	     time_correction,
+	     time_warp_mode);
     erts_initialized = 1;
 }
 
@@ -299,12 +320,15 @@ erl_init(int ncpu,
 	 int legacy_proc_tab,
 	 int port_tab_sz,
 	 int port_tab_sz_ignore_files,
-	 int legacy_port_tab)
+	 int legacy_port_tab,
+	 int time_correction,
+	 ErtsTimeWarpMode time_warp_mode)
 {
     init_benchmarking();
 
+    erts_bif_unique_init();
     erts_init_monitors();
-    erts_init_time();
+    erts_init_time(time_correction, time_warp_mode);
     erts_init_sys_common_misc();
     erts_init_process(ncpu, proc_tab_sz, legacy_proc_tab);
     erts_init_scheduling(no_schedulers,
@@ -315,6 +339,7 @@ erl_init(int ncpu,
 			 no_dirty_io_schedulers
 #endif
 			 );
+    erts_late_init_time_sup();
     erts_init_cpu_topology(); /* Must be after init_scheduling */
     erts_init_gc(); /* Must be after init_scheduling */
     erts_alloc_late_init();
@@ -364,12 +389,13 @@ erl_init(int ncpu,
     erl_nif_init();
 }
 
-static void
+static Eterm
 erl_first_process_otp(char* modname, void* code, unsigned size, int argc, char** argv)
 {
     int i;
     Eterm start_mod;
     Eterm args;
+    Eterm res;
     Eterm* hp;
     Process parent;
     ErlSpawnOpts so;
@@ -399,10 +425,11 @@ erl_first_process_otp(char* modname, void* code, unsigned size, int argc, char**
     hp += 2;
     args = CONS(hp, env, args);
 
-    so.flags = 0;
-    (void) erl_create_process(&parent, start_mod, am_start, args, &so);
+    so.flags = SPO_SYSTEM_PROC;
+    res = erl_create_process(&parent, start_mod, am_start, args, &so);
     erts_smp_proc_unlock(&parent, ERTS_PROC_LOCK_MAIN);
     erts_cleanup_empty_process(&parent);
+    return res;
 }
 
 Eterm
@@ -508,9 +535,9 @@ void erts_usage(void)
 
     /*    erts_fprintf(stderr, "-b func    set the boot function (default boot)\n"); */
 
-    erts_fprintf(stderr, "-c             disable continuous date/time correction with\n");
-    erts_fprintf(stderr, "               respect to uptime\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, "-fn[u|a|l]     Control how filenames are interpreted\n");
@@ -682,7 +709,6 @@ early_init(int *argc, char **argv) /*
 
     erts_sched_compact_load = 1;
     erts_printf_eterm_func = erts_printf_term;
-    erts_disable_tolerant_timeofday = 0;
     display_items = 200;
     erts_backtrace_depth = DEFAULT_BACKTRACE_SIZE;
     erts_async_max_threads = ERTS_DEFAULT_NO_ASYNC_THREADS;
@@ -1145,6 +1171,7 @@ early_init(int *argc, char **argv) /*
 
     /* Creates threads on Windows that depend on the arguments, so has to be after erl_sys_args */
     erl_sys_init();
+    erts_early_init_time_sup();
 
     erts_ets_realloc_always_moves = 0;
     erts_ets_always_compress = 0;
@@ -1188,7 +1215,11 @@ erl_start(int argc, char **argv)
     int port_tab_sz_ignore_files = 0;
     int legacy_proc_tab = 0;
     int legacy_port_tab = 0;
+    int time_correction;
+    ErtsTimeWarpMode time_warp_mode;
 
+    set_default_time_adj(&time_correction,
+			 &time_warp_mode);
 
     envbufsz = sizeof(envbuf);
     if (erts_sys_getenv_raw(ERL_MAX_ETS_TABLES_ENV, envbuf, &envbufsz) == 0)
@@ -1906,9 +1937,55 @@ erl_start(int argc, char **argv)
 	    }
 	    break;
 	}
+	case 'C':
+	    arg = get_arg(argv[i]+2, argv[i+1], &i);
+	    if (sys_strcmp(arg, "no_time_warp") == 0)
+		time_warp_mode = ERTS_NO_TIME_WARP_MODE;
+	    else if (sys_strcmp(arg, "single_time_warp") == 0)
+		time_warp_mode = ERTS_SINGLE_TIME_WARP_MODE;
+	    else if (sys_strcmp(arg, "multi_time_warp") == 0)
+		time_warp_mode = ERTS_MULTI_TIME_WARP_MODE;
+	    else {
+		erts_fprintf(stderr,
+			     "Invalid time warp mode: %s\n", arg);
+		erts_usage();
+	    }
+	    break;
 	case 'c':
-	    if (argv[i][2] == 0) { /* -c: documented option */
-		erts_disable_tolerant_timeofday = 1;
+	    if (sys_strcmp(argv[i]+2, "false") == 0)
+		goto time_correction_false;
+	    else if (sys_strcmp(argv[i]+2, "true") == 0)
+		goto time_correction_true;
+#ifdef ERTS_OPCODE_COUNTER_SUPPORT
+	    else if (argv[i][2] == 'i') { /* -ci: undcoumented option*/
+		count_instructions = 1;
+	    }
+#endif
+	    else if (argv[i][2] == '\0') {
+		if (i + 1 >= argc)
+		    goto time_correction_false;
+		else {
+		    if (sys_strcmp(argv[i+1], "false") == 0) {
+			(void) get_arg(argv[i]+2, argv[i+1], &i);
+			goto time_correction_false;
+		    }
+		    else if (sys_strcmp(argv[i+1], "true") == 0) {
+			(void) get_arg(argv[i]+2, argv[i+1], &i);
+		    time_correction_true:
+			time_correction = 1;
+			break;
+		    }
+		    else {
+		    time_correction_false:
+			time_correction = 0;
+			break;
+		    }
+		}
+	    }
+	    else {
+		arg = get_arg(argv[i]+2, argv[i+1], &i);
+		erts_fprintf(stderr, "Invalid time correnction value: %s\n", arg);
+		erts_usage();
 	    }
 	    break;
 	case 'W':
@@ -1955,6 +2032,30 @@ erl_start(int argc, char **argv)
 	i++;
     }
 
+    if (!erts_check_time_adj_support(time_correction, time_warp_mode)) {
+	char *time_correction_str = time_correction ? "Enabled" : "Disabled";
+	char *time_warp_str = "undefined";
+	switch (time_warp_mode) {
+	case ERTS_NO_TIME_WARP_MODE:
+	    time_warp_str = "no";
+	    break;
+	case ERTS_SINGLE_TIME_WARP_MODE:
+	    time_warp_str = "single";
+	    break;
+	case ERTS_MULTI_TIME_WARP_MODE:
+	    time_warp_str = "multi";
+	    break;
+	default:
+	    time_warp_str = "undefined";
+	    break;
+	}
+	erts_fprintf(stderr, "%s time correction with %s time warp mode "
+		     "is not supported on this platform\n",
+		     time_correction_str,
+		     time_warp_str);
+	erts_usage();
+    }
+
 /* Output format on windows for sprintf defaults to three exponents.
  * We use two-exponent to mimic normal sprintf behaviour.
  */
@@ -1988,7 +2089,9 @@ erl_start(int argc, char **argv)
 	     legacy_proc_tab,
 	     port_tab_sz,
 	     port_tab_sz_ignore_files,
-	     legacy_port_tab);
+	     legacy_port_tab,
+	     time_correction,
+	     time_warp_mode);
 
     load_preloaded();
     erts_end_staging_code_ix();
@@ -1996,7 +2099,11 @@ erl_start(int argc, char **argv)
 
     erts_initialized = 1;
 
-    erl_first_process_otp("otp_ring0", NULL, 0, boot_argc, boot_argv);
+    {
+	Eterm init = erl_first_process_otp("otp_ring0", NULL, 0,
+					   boot_argc, boot_argv);
+	erts_bif_timer_start_servers(init);
+    }
 
 #ifdef ERTS_SMP
     erts_start_schedulers();
diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c
index b105ece6f1..261460d054 100644
--- a/erts/emulator/beam/erl_lock_check.c
+++ b/erts/emulator/beam/erl_lock_check.c
@@ -140,7 +140,6 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"async_enq_mtx",			NULL			},
 #ifdef ERTS_SMP
     {	"atom_tab",				NULL			},
-    {	"make_ref",				NULL			},
     {	"misc_op_list_pre_alloc_lock",		"address"		},
     {	"message_pre_alloc_lock",		"address"		},
     {	"ptimer_pre_alloc_lock",		"address",		},
@@ -168,6 +167,8 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"timer_wheel",				NULL			},
     {	"system_block",				NULL			},
     {	"timeofday",				NULL			},
+    {	"get_time",				NULL			},
+    {	"get_corrected_time",			NULL			},
     {	"breakpoints",				NULL			},
     {	"pollsets_lock",			NULL			},
     {	"pix_lock",				"address"		},
@@ -184,10 +185,8 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {   "efile_drv dtrace mutex",               NULL                    },
 #endif
     {	"mtrace_buf",				NULL			},
-#ifdef __WIN32__
 #ifdef ERTS_SMP
-    {   "sys_gethrtime",                        NULL                    },
-#endif
+    {	"os_monotonic_time",			NULL			},
 #endif
     {	"erts_alloc_hard_debug",		NULL			},
     {	"hard_dbg_mseg",		        NULL	                },
diff --git a/erts/emulator/beam/erl_lock_count.c b/erts/emulator/beam/erl_lock_count.c
index cf6996ea06..ddeb56a6be 100644
--- a/erts/emulator/beam/erl_lock_count.c
+++ b/erts/emulator/beam/erl_lock_count.c
@@ -104,11 +104,10 @@ static void lcnt_clear_stats(erts_lcnt_lock_stats_t *stats) {
 }
 
 static void lcnt_time(erts_lcnt_time_t *time) {
-#if 0 || defined(HAVE_GETHRTIME)
-    SysHrTime hr_time;
-    hr_time  = sys_gethrtime();
-    time->s  = (unsigned long)(hr_time / 1000000000LL);
-    time->ns = (unsigned long)(hr_time - 1000000000LL*time->s);
+#if 0 || defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT)
+    ErtsMonotonicTime mtime = ERTS_MONOTONIC_TO_NSEC(erts_os_monotonic_time());
+    time->s  = (unsigned long) (mtime / 1000000000LL);
+    time->ns = (unsigned long) (mtime - 1000000000LL*time->s);
 #else
   SysTimeval tv;
   sys_gettimeofday(&tv);
diff --git a/erts/emulator/beam/erl_lock_count.h b/erts/emulator/beam/erl_lock_count.h
index ffbb93da1b..09fadd7e9e 100644
--- a/erts/emulator/beam/erl_lock_count.h
+++ b/erts/emulator/beam/erl_lock_count.h
@@ -76,7 +76,7 @@
 
 /* histogram */
 #define ERTS_LCNT_HISTOGRAM_MAX_NS    (((unsigned long)1LL << 28) - 1)
-#if 0 || defined(HAVE_GETHRTIME)
+#if 0 || defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT)
 #define ERTS_LCNT_HISTOGRAM_SLOT_SIZE (30)
 #define ERTS_LCNT_HISTOGRAM_RSHIFT    (0)
 #else
diff --git a/erts/emulator/beam/erl_message.c b/erts/emulator/beam/erl_message.c
index 43a03c793e..22cbae10d1 100644
--- a/erts/emulator/beam/erl_message.c
+++ b/erts/emulator/beam/erl_message.c
@@ -994,7 +994,7 @@ erts_send_message(Process* sender,
 #endif
 	    );
         BM_SWAP_TIMER(send,system);
-    } else if (sender == receiver) {
+    } else if (sender == receiver && !(sender->flags & F_OFF_HEAP_MSGS)) {
 	/* Drop message if receiver has a pending exit ... */
 #ifdef ERTS_SMP
 	ErtsProcLocks need_locks = (~(*receiver_locks)
diff --git a/erts/emulator/beam/erl_message.h b/erts/emulator/beam/erl_message.h
index 6b8c3cebc7..8713941769 100644
--- a/erts/emulator/beam/erl_message.h
+++ b/erts/emulator/beam/erl_message.h
@@ -213,15 +213,25 @@ do {									\
     if ((M)->data.attached) {						\
 	Uint need__ = erts_msg_attached_data_size((M));			\
  	if ((ST) - (HT) >= need__) {					\
-	    Uint *htop__ = (HT);					\
+	    Uint *htop__;						\
+	move__attached__msg__data____:					\
+	    htop__ = (HT);						\
 	    erts_move_msg_attached_data_to_heap(&htop__, &MSO((P)), (M));\
 	    ASSERT(htop__ - (HT) <= need__);				\
 	    (HT) = htop__;						\
 	}								\
 	else {								\
+	    int off_heap_msgs__ = (int) (P)->flags & F_OFF_HEAP_MSGS;	\
+	    if (!off_heap_msgs__)					\
+		need__ = 0;						\
 	    { SWPO ; }							\
-	    (FC) -= erts_garbage_collect((P), 0, NULL, 0);		\
+	    (FC) -= erts_garbage_collect((P), need__, NULL, 0);		\
 	    { SWPI ; }							\
+	    if (off_heap_msgs__) {					\
+		ASSERT((M)->data.attached);				\
+		ASSERT((ST) - (HT) >= need__);				\
+		goto move__attached__msg__data____;			\
+	    }								\
 	}								\
 	ASSERT(!(M)->data.attached);					\
     }									\
diff --git a/erts/emulator/beam/erl_monitors.h b/erts/emulator/beam/erl_monitors.h
index fb11dbbd22..9972890db7 100644
--- a/erts/emulator/beam/erl_monitors.h
+++ b/erts/emulator/beam/erl_monitors.h
@@ -82,6 +82,7 @@
 /* Type tags for monitors */
 #define MON_ORIGIN 1
 #define MON_TARGET 3
+#define MON_TIME_OFFSET 7
 
 /* Type tags for links */
 #define LINK_PID 1   /* ...Or port */
@@ -103,7 +104,7 @@ typedef struct erts_monitor_or_link {
 typedef struct erts_monitor {
     struct erts_monitor *left, *right; 
     Sint16 balance;
-    Uint16 type;  /* MON_ORIGIN | MON_TARGET */
+    Uint16 type;  /* MON_ORIGIN | MON_TARGET | MON_TIME_OFFSET */
     Eterm ref;
     Eterm pid;    /* In case of distributed named monitor, this is the
 		     nodename atom in MON_ORIGIN process, otherwise a pid or
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index e28365cb1b..c7c8b3fee3 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -36,6 +36,7 @@
 #include "erl_thr_progress.h"
 #include "dtrace-wrapper.h"
 #include "erl_process.h"
+#include "erl_bif_unique.h"
 #if defined(USE_DYNAMIC_TRACE) && (defined(USE_DTRACE) || defined(USE_SYSTEMTAP))
 #define HAVE_USE_DTRACE 1
 #endif
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index ba09ee57c2..f74a2ee54c 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -43,6 +43,7 @@
 #include "erl_async.h"
 #include "dtrace-wrapper.h"
 #include "erl_ptab.h"
+#include "erl_bif_unique.h"
 
 
 #define ERTS_DELAYED_WAKEUP_INFINITY (~(Uint64) 0)
@@ -701,8 +702,8 @@ init_sched_wall_time(ErtsSchedWallTime *swtp)
 static ERTS_INLINE Uint64
 sched_wall_time_ts(void)
 {
-#ifdef HAVE_GETHRTIME
-    return (Uint64) sys_gethrtime();
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    return (Uint64) erts_os_monotonic_time();
 #else
     Uint64 res;
     SysTimeval tv;
@@ -2185,7 +2186,7 @@ aux_work_timeout_late_init(void)
 {
     aux_work_tmo->initialized = 1;
     if (erts_atomic32_read_nob(&aux_work_tmo->refc)) {
-	aux_work_tmo->timer.data.active = 0;
+	erts_init_timer(&aux_work_tmo->timer.data);
 	erts_set_timer(&aux_work_tmo->timer.data,
 		       aux_work_timeout,
 		       NULL,
@@ -2218,7 +2219,6 @@ aux_work_timeout(void *unused)
     if (refc != 1
 	|| 1 != erts_atomic32_cmpxchg_relb(&aux_work_tmo->refc, 0, 1)) {
 	/* Setup next timeout... */
-	aux_work_tmo->timer.data.active = 0;
 	erts_set_timer(&aux_work_tmo->timer.data,
 		       aux_work_timeout,
 		       NULL,
@@ -2237,7 +2237,7 @@ setup_aux_work_timer(void)
     else
 #endif
     {
-	aux_work_tmo->timer.data.active = 0;
+	erts_init_timer(&aux_work_tmo->timer.data);
 	erts_set_timer(&aux_work_tmo->timer.data,
 		       aux_work_timeout,
 		       NULL,
@@ -2638,6 +2638,13 @@ thr_prgr_fin_wait(void *vssi)
 
 static void init_aux_work_data(ErtsAuxWorkData *awdp, ErtsSchedulerData *esdp, char *dawwp);
 
+void
+erts_interupt_aux_thread_timed(ErtsMonotonicTime timeout_time)
+{
+    /* TODO only poke when needed (based on timeout_time) */
+    erts_sched_poke(ERTS_SCHED_SLEEP_INFO_IX(-1));
+}
+
 static void *
 aux_thread(void *unused)
 {
@@ -2646,6 +2653,11 @@ aux_thread(void *unused)
     erts_aint32_t aux_work;
     ErtsThrPrgrCallbacks callbacks;
     int thr_prgr_active = 1;
+    ErtsTimerWheel *timer_wheel = erts_default_timer_wheel;
+    ErtsNextTimeoutRef nxt_tmo_ref = erts_get_next_timeout_reference(timer_wheel);
+
+    if (!timer_wheel)
+	ERTS_INTERNAL_ERROR("Missing aux timer wheel");
 
 #ifdef ERTS_ENABLE_LOCK_CHECK
     {
@@ -2669,6 +2681,7 @@ aux_thread(void *unused)
     sched_prep_spin_wait(ssi);
 
     while (1) {
+	ErtsMonotonicTime current_time;
 	erts_aint32_t flgs;
 
 	aux_work = erts_atomic32_read_acqb(&ssi->aux_work);
@@ -2680,28 +2693,56 @@ aux_thread(void *unused)
 		erts_thr_progress_leader_update(NULL);
 	}
 
-	if (!aux_work) {
-	    if (thr_prgr_active)
-		erts_thr_progress_active(NULL, thr_prgr_active = 0);
-	    erts_thr_progress_prepare_wait(NULL);
+	if (aux_work) {
+	    current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(nxt_tmo_ref)) {
+		if (!thr_prgr_active)
+		    erts_thr_progress_active(NULL, thr_prgr_active = 1);
+		erts_bump_timers(timer_wheel, current_time);
+	    }
+	}
+	else {
+	    ErtsMonotonicTime timeout_time;
+	    timeout_time = erts_check_next_timeout_time(timer_wheel,
+							ERTS_SEC_TO_MONOTONIC(10*60));
+	    current_time = erts_get_monotonic_time();
+	    if (current_time >= timeout_time) {
+		if (!thr_prgr_active)
+		    erts_thr_progress_active(NULL, thr_prgr_active = 1);
+	    }
+	    else {
+		if (thr_prgr_active)
+		    erts_thr_progress_active(NULL, thr_prgr_active = 0);
+		erts_thr_progress_prepare_wait(NULL);
 
-	    ERTS_SCHED_FAIR_YIELD();
+		ERTS_SCHED_FAIR_YIELD();
 
-	    flgs = sched_spin_wait(ssi, 0);
+		flgs = sched_spin_wait(ssi, 0);
 
-	    if (flgs & ERTS_SSI_FLG_SLEEPING) {
-		ASSERT(flgs & ERTS_SSI_FLG_WAITING);
-		flgs = sched_set_sleeptype(ssi, ERTS_SSI_FLG_TSE_SLEEPING);
 		if (flgs & ERTS_SSI_FLG_SLEEPING) {
-		    int res;
-		    ASSERT(flgs & ERTS_SSI_FLG_TSE_SLEEPING);
 		    ASSERT(flgs & ERTS_SSI_FLG_WAITING);
-		    do {
-			res = erts_tse_wait(ssi->event);
-		    } while (res == EINTR);
+		    flgs = sched_set_sleeptype(ssi, ERTS_SSI_FLG_TSE_SLEEPING);
+		    if (flgs & ERTS_SSI_FLG_SLEEPING) {
+			int res;
+			ASSERT(flgs & ERTS_SSI_FLG_TSE_SLEEPING);
+			ASSERT(flgs & ERTS_SSI_FLG_WAITING);
+			current_time = erts_get_monotonic_time();
+			do {
+			    Sint64 timeout;
+			    if (current_time >= timeout_time)
+				break;
+			    timeout = ERTS_MONOTONIC_TO_NSEC(timeout_time
+							     - current_time
+							     - 1) + 1;
+			    res = erts_tse_twait(ssi->event, timeout);
+			    current_time = erts_get_monotonic_time();
+			} while (res == EINTR);
+		    }
 		}
+		erts_thr_progress_finalize_wait(NULL);
 	    }
-	    erts_thr_progress_finalize_wait(NULL);
+	    if (current_time >= timeout_time)
+		erts_bump_timers(timer_wheel, current_time);
 	}
 
 	flgs = sched_prep_spin_wait(ssi);
@@ -2768,6 +2809,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	    sched_wall_time_change(esdp, thr_prgr_active);
 
 	while (1) {
+	    ErtsMonotonicTime current_time;
 
 	    aux_work = erts_atomic32_read_acqb(&ssi->aux_work);
 	    if (aux_work) {
@@ -2781,34 +2823,65 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 		    erts_thr_progress_leader_update(esdp);
 	    }
 
-	    if (aux_work)
+	    if (aux_work) {
 		flgs = erts_smp_atomic32_read_acqb(&ssi->flags);
+		current_time = erts_get_monotonic_time();
+		if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref)) {
+		    if (!ERTS_SCHEDULER_IS_DIRTY(esdp) && !thr_prgr_active) {
+			erts_thr_progress_active(esdp, thr_prgr_active = 1);
+			sched_wall_time_change(esdp, 1);
+		    }
+		    erts_bump_timers(esdp->timer_wheel, current_time);
+		}
+	    }
 	    else {
-		if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
-		    if (thr_prgr_active) {
-			erts_thr_progress_active(esdp, thr_prgr_active = 0);
-			sched_wall_time_change(esdp, 0);
+		ErtsMonotonicTime timeout_time;
+		timeout_time = erts_check_next_timeout_time(esdp->timer_wheel,
+							    ERTS_SEC_TO_MONOTONIC(10*60));
+		current_time = erts_get_monotonic_time();
+		if (current_time >= timeout_time) {
+		    if (!ERTS_SCHEDULER_IS_DIRTY(esdp) && !thr_prgr_active) {
+			erts_thr_progress_active(esdp, thr_prgr_active = 1);
+			sched_wall_time_change(esdp, 1);
 		    }
-		    erts_thr_progress_prepare_wait(esdp);
 		}
+		else {
+		    if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
+			if (thr_prgr_active) {
+			    erts_thr_progress_active(esdp, thr_prgr_active = 0);
+			    sched_wall_time_change(esdp, 0);
+			}
+			erts_thr_progress_prepare_wait(esdp);
+		    }
 
-		ERTS_SCHED_FAIR_YIELD();
+		    ERTS_SCHED_FAIR_YIELD();
 
-		flgs = sched_spin_wait(ssi, spincount);
-		if (flgs & ERTS_SSI_FLG_SLEEPING) {
-		    ASSERT(flgs & ERTS_SSI_FLG_WAITING);
-		    flgs = sched_set_sleeptype(ssi, ERTS_SSI_FLG_TSE_SLEEPING);
+		    flgs = sched_spin_wait(ssi, spincount);
 		    if (flgs & ERTS_SSI_FLG_SLEEPING) {
-			int res;
-			ASSERT(flgs & ERTS_SSI_FLG_TSE_SLEEPING);
 			ASSERT(flgs & ERTS_SSI_FLG_WAITING);
-			do {
-			    res = erts_tse_wait(ssi->event);
-			} while (res == EINTR);
+			flgs = sched_set_sleeptype(ssi, ERTS_SSI_FLG_TSE_SLEEPING);
+			if (flgs & ERTS_SSI_FLG_SLEEPING) {
+			    int res;
+			    ASSERT(flgs & ERTS_SSI_FLG_TSE_SLEEPING);
+			    ASSERT(flgs & ERTS_SSI_FLG_WAITING);
+			    current_time = erts_get_monotonic_time();
+			    do {
+				Sint64 timeout;
+				if (current_time >= timeout_time)
+				    break;
+				timeout = ERTS_MONOTONIC_TO_NSEC(timeout_time
+								 - current_time
+								 - 1) + 1;
+				res = erts_tse_twait(ssi->event, timeout);
+				current_time = erts_get_monotonic_time();
+			    } while (res == EINTR);
+			}
 		    }
+		    if (!ERTS_SCHEDULER_IS_DIRTY(esdp))
+			erts_thr_progress_finalize_wait(esdp);
 		}
-		if (!ERTS_SCHEDULER_IS_DIRTY(esdp))
-		    erts_thr_progress_finalize_wait(esdp);
+		if (current_time >= timeout_time)
+		    erts_bump_timers(esdp->timer_wheel, current_time);
 	    }
 
 	    if (!(flgs & ERTS_SSI_FLG_WAITING)) {
@@ -2841,7 +2914,6 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
     else
 #endif
     {
-	erts_aint_t dt;
 
 	erts_smp_atomic32_set_relb(&function_calls, 0);
 	*fcalls = 0;
@@ -2866,6 +2938,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	    goto sys_aux_work;
 
 	while (spincount-- > 0) {
+	    ErtsMonotonicTime current_time;
 
 	sys_poll_aux_work:
 
@@ -2875,8 +2948,9 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	    ASSERT(!erts_port_task_have_outstanding_io_tasks());
 	    erl_sys_schedule(1); /* Might give us something to do */
 
-	    dt = erts_do_time_read_and_reset();
-	    if (dt) erts_bump_timer(dt);
+	    current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
+		erts_bump_timers(esdp->timer_wheel, current_time);
 
 	sys_aux_work:
 #ifndef ERTS_SMP
@@ -2991,8 +3065,11 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 
 	erl_sys_schedule(0);
 
-	dt = erts_do_time_read_and_reset();
-	if (dt) erts_bump_timer(dt);
+	{
+	    ErtsMonotonicTime current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
+		erts_bump_timers(esdp->timer_wheel, current_time);
+	}
 
 #ifndef ERTS_SMP
 	if (rq->len == 0 && !rq->misc.start)
@@ -5262,6 +5339,10 @@ init_scheduler_data(ErtsSchedulerData* esdp, int num,
 #else
     esdp->no = (Uint) num;
 #endif
+
+    esdp->timer_wheel = erts_default_timer_wheel;
+    esdp->next_tmo_ref = erts_get_next_timeout_reference(esdp->timer_wheel);
+
     esdp->ssi = ssi;
     esdp->current_process = NULL;
     esdp->current_port = NULL;
@@ -5274,6 +5355,9 @@ init_scheduler_data(ErtsSchedulerData* esdp, int num,
     esdp->run_queue = runq;
     esdp->run_queue->scheduler = esdp;
 
+    esdp->thr_id = (Uint32) num;
+    erts_sched_bif_unique_init(esdp);
+
     if (daww_ptr) {
 	init_aux_work_data(&esdp->aux_work_data, esdp, *daww_ptr);
 #ifdef ERTS_SMP
@@ -5834,6 +5918,13 @@ schedule_out_process(ErtsRunQueue *c_rq, erts_aint32_t state, Process *p, Proces
     int check_emigration_need;
 #endif
 
+#ifdef ERTS_SMP
+    if ((p->static_flags & ERTS_STC_FLG_PREFER_SCHED)
+	&& p->preferred_run_queue != RUNQ_READ_RQ(&p->run_queue)) {
+	RUNQ_SET_RQ(&p->run_queue, p->preferred_run_queue);
+    }
+#endif
+
     a = state;
 
     while (1) {
@@ -5872,6 +5963,7 @@ schedule_out_process(ErtsRunQueue *c_rq, erts_aint32_t state, Process *p, Proces
 	    free_proxy_proc(proxy);
 
 	erts_smp_runq_lock(c_rq);
+
 	return 0;
 
 #ifdef ERTS_DIRTY_SCHEDULERS
@@ -6584,7 +6676,7 @@ suspend_scheduler(ErtsSchedulerData *esdp)
 			    int res;
 
 			    do {
-				res = erts_tse_wait(ssi->event);
+				res = erts_tse_twait(ssi->event, -1);
 			    } while (res == EINTR);
 			}
 		    }
@@ -6747,6 +6839,7 @@ suspend_scheduler(ErtsSchedulerData *esdp)
 	    erts_smp_mtx_unlock(&schdlr_sspnd.mtx);
 
 	    while (1) {
+		ErtsMonotonicTime current_time;
 		erts_aint32_t qmask;
 		erts_aint32_t flgs;
 
@@ -6771,30 +6864,64 @@ suspend_scheduler(ErtsSchedulerData *esdp)
 		    }
 		}
 
-		if (!aux_work) {
-		    if (thr_prgr_active) {
-			erts_thr_progress_active(esdp, thr_prgr_active = 0);
-			sched_wall_time_change(esdp, 0);
+		if (aux_work) {
+		    current_time = erts_get_monotonic_time();
+		    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref)) {
+			if (!thr_prgr_active) {
+			    erts_thr_progress_active(esdp, thr_prgr_active = 1);
+			    sched_wall_time_change(esdp, 1);
+			}
+			erts_bump_timers(esdp->timer_wheel, current_time);
 		    }
-		    erts_thr_progress_prepare_wait(esdp);
-		    flgs = sched_spin_suspended(ssi,
-						ERTS_SCHED_SUSPEND_SLEEP_SPINCOUNT);
-		    if (flgs == (ERTS_SSI_FLG_SLEEPING
-				 | ERTS_SSI_FLG_WAITING
-				 | ERTS_SSI_FLG_SUSPENDED)) {
-			flgs = sched_set_suspended_sleeptype(ssi);
+		}
+		else {
+		    ErtsMonotonicTime timeout_time;
+		    timeout_time = erts_check_next_timeout_time(esdp->timer_wheel,
+								ERTS_SEC_TO_MONOTONIC(60*60));
+		    current_time = erts_get_monotonic_time();
+
+		    if (current_time >= timeout_time) {
+			if (!thr_prgr_active) {
+			    erts_thr_progress_active(esdp, thr_prgr_active = 1);
+			    sched_wall_time_change(esdp, 1);
+			}
+		    }
+		    else {		    
+			if (thr_prgr_active) {
+			    erts_thr_progress_active(esdp, thr_prgr_active = 0);
+			    sched_wall_time_change(esdp, 0);
+			}
+			erts_thr_progress_prepare_wait(esdp);
+			flgs = sched_spin_suspended(ssi,
+						    ERTS_SCHED_SUSPEND_SLEEP_SPINCOUNT);
 			if (flgs == (ERTS_SSI_FLG_SLEEPING
-				     | ERTS_SSI_FLG_TSE_SLEEPING
 				     | ERTS_SSI_FLG_WAITING
 				     | ERTS_SSI_FLG_SUSPENDED)) {
-			    int res;
-
-			    do {
-				res = erts_tse_wait(ssi->event);
-			    } while (res == EINTR);
+			    flgs = sched_set_suspended_sleeptype(ssi);
+			    if (flgs == (ERTS_SSI_FLG_SLEEPING
+					 | ERTS_SSI_FLG_TSE_SLEEPING
+					 | ERTS_SSI_FLG_WAITING
+					 | ERTS_SSI_FLG_SUSPENDED)) {
+				int res;
+
+				current_time = erts_get_monotonic_time();
+				do {
+				    Sint64 timeout;
+				    if (current_time >= timeout_time)
+					break;
+				    timeout = ERTS_MONOTONIC_TO_NSEC(timeout_time
+								     - current_time
+								     - 1) + 1;
+				    res = erts_tse_twait(ssi->event, timeout);
+				    current_time = erts_get_monotonic_time();
+				} while (res == EINTR);
+			    }
 			}
+			erts_thr_progress_finalize_wait(esdp);
 		    }
-		    erts_thr_progress_finalize_wait(esdp);
+
+		    if (current_time >= timeout_time)
+			erts_bump_timers(esdp->timer_wheel, current_time);
 		}
 
 		flgs = sched_prep_spin_suspended(ssi, (ERTS_SSI_FLG_WAITING
@@ -7613,6 +7740,9 @@ sched_thread_func(void *vesdp)
     ErtsThrPrgrCallbacks callbacks;
     ErtsSchedulerData *esdp = vesdp;
     Uint no = esdp->no;
+
+    esdp->timer_wheel = erts_create_timer_wheel((int) no);
+    esdp->next_tmo_ref = erts_get_next_timeout_reference(esdp->timer_wheel);
 #ifdef ERTS_SMP
     ERTS_SCHED_SLEEP_INFO_IX(no - 1)->event = erts_tse_fetch();
     callbacks.arg = (void *) esdp->ssi;
@@ -7715,6 +7845,8 @@ sched_dirty_cpu_thread_func(void *vesdp)
     callbacks.wait = NULL;
     callbacks.finalize_wait = NULL;
 
+    esdp->thr_id += erts_no_schedulers;
+
     erts_thr_progress_register_unmanaged_thread(&callbacks);
 #ifdef ERTS_ENABLE_LOCK_CHECK
     {
@@ -7776,6 +7908,8 @@ sched_dirty_io_thread_func(void *vesdp)
     callbacks.wait = NULL;
     callbacks.finalize_wait = NULL;
 
+    esdp->thr_id += erts_no_schedulers + erts_no_dirty_cpu_schedulers;
+
     erts_thr_progress_register_unmanaged_thread(&callbacks);
 #ifdef ERTS_ENABLE_LOCK_CHECK
     {
@@ -8878,7 +9012,6 @@ Process *schedule(Process *p, int calls)
 {
     Process *proxy_p = NULL;
     ErtsRunQueue *rq;
-    erts_aint_t dt;
     ErtsSchedulerData *esdp;
     int context_reds;
     int fcalls;
@@ -9008,11 +9141,13 @@ Process *schedule(Process *p, int calls)
 
 	ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-	dt = erts_do_time_read_and_reset();
-	if (dt) {
-	    erts_smp_runq_unlock(rq);
-	    erts_bump_timer(dt);
-	    erts_smp_runq_lock(rq);
+	{
+	    ErtsMonotonicTime current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref)) {
+		erts_smp_runq_unlock(rq);
+		erts_bump_timers(esdp->timer_wheel, current_time);
+		erts_smp_runq_lock(rq);
+	    }
 	}
 	BM_STOP_TIMER(system);
 
@@ -9158,6 +9293,7 @@ Process *schedule(Process *p, int calls)
 	else if (!ERTS_SCHEDULER_IS_DIRTY(esdp) &&
 		 (fcalls > input_reductions &&
 		  prepare_for_sys_schedule(esdp, !0))) {
+	    ErtsMonotonicTime current_time;
 	    /*
 	     * Schedule system-level activities.
 	     */
@@ -9170,8 +9306,10 @@ Process *schedule(Process *p, int calls)
 #endif
 	    erts_smp_runq_unlock(rq);
 	    erl_sys_schedule(1);
-	    dt = erts_do_time_read_and_reset();
-	    if (dt) erts_bump_timer(dt);
+
+	    current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
+		erts_bump_timers(esdp->timer_wheel, current_time);
 
 #ifdef ERTS_SMP
 	    erts_smp_runq_lock(rq);
@@ -10476,7 +10614,10 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 	    int ix = so->scheduler-1;
 	    ASSERT(0 <= ix && ix < erts_no_run_queues);
 	    rq = ERTS_RUNQ_IX(ix);
-	    state |= ERTS_PSFLG_BOUND;
+	    if (!(so->flags & SPO_PREFER_SCHED)) {
+		/* Unsupported feature... */
+		state |= ERTS_PSFLG_BOUND;
+	    }
 	}
 	prio = (erts_aint32_t) so->priority;
     }
@@ -10484,6 +10625,9 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     state |= (((prio & ERTS_PSFLGS_PRIO_MASK) << ERTS_PSFLGS_ACT_PRIO_OFFSET)
 	      | ((prio & ERTS_PSFLGS_PRIO_MASK) << ERTS_PSFLGS_USR_PRIO_OFFSET));
 
+    if (so->flags & SPO_OFF_HEAP_MSGS)
+	state |= ERTS_PSFLG_OFF_HEAP_MSGS;
+
     if (!rq)
 	rq = erts_get_runq_proc(parent);
 
@@ -10507,11 +10651,25 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     heap_need = arg_size;
 
     p->flags = erts_default_process_flags;
+    if (so->flags & SPO_OFF_HEAP_MSGS)
+	p->flags |= F_OFF_HEAP_MSGS;
 
+#ifdef ERTS_SMP
+    p->preferred_run_queue = NULL;
+#endif
+    p->static_flags = 0;
+    if (so->flags & SPO_SYSTEM_PROC)
+	p->static_flags |= ERTS_STC_FLG_SYSTEM_PROC;
     if (so->flags & SPO_USE_ARGS) {
 	p->min_heap_size  = so->min_heap_size;
 	p->min_vheap_size = so->min_vheap_size;
 	p->max_gen_gcs    = so->max_gen_gcs;
+	if (so->flags & SPO_PREFER_SCHED) {
+#ifdef ERTS_SMP
+	    p->preferred_run_queue = rq;
+#endif
+	    p->static_flags |= ERTS_STC_FLG_PREFER_SCHED;
+	}
     } else {
 	p->min_heap_size  = H_MIN_SIZE;
 	p->min_vheap_size = BIN_VH_MIN_SIZE;
@@ -10589,7 +10747,7 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 #ifdef ERTS_SMP
     p->common.u.alive.ptimer = NULL;
 #else
-    sys_memset(&p->common.u.alive.tm, 0, sizeof(ErlTimer));
+    erts_init_timer(&p->common.u.alive.tm);
 #endif
 
     p->common.u.alive.reg = NULL;
@@ -10782,7 +10940,7 @@ void erts_init_empty_process(Process *p)
 #ifdef ERTS_SMP
     p->common.u.alive.ptimer = NULL;
 #else
-    memset(&(p->common.u.alive.tm), 0, sizeof(ErlTimer));
+    erts_init_timer(&p->common.u.alive.tm);
 #endif
     p->next = NULL;
     p->off_heap.first = NULL;
@@ -10832,6 +10990,8 @@ void erts_init_empty_process(Process *p)
 
     p->parent = NIL;
     p->approx_started = 0;
+    p->static_flags = 0;
+
     p->common.u.alive.started_interval = 0;
 
 #ifdef HIPE
@@ -10857,6 +11017,7 @@ void erts_init_empty_process(Process *p)
     p->pending_suspenders = NULL;
     p->pending_exit.reason = THE_NON_VALUE;
     p->pending_exit.bp = NULL;
+    p->preferred_run_queue = NULL;
     erts_proc_lock_init(p);
     erts_smp_proc_unlock(p, ERTS_PROC_LOCKS_ALL);
     RUNQ_SET_RQ(&p->run_queue, ERTS_RUNQ_IX(0));
@@ -11482,7 +11643,8 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
     ErtsMonitor *rmon;
     Process *rp;
 
-    if (mon->type == MON_ORIGIN) {
+    switch (mon->type) {
+    case MON_ORIGIN:
 	/* We are monitoring someone else, we need to demonitor that one.. */
 	if (is_atom(mon->pid)) { /* remote by name */
 	    ASSERT(is_node_name_atom(mon->pid));
@@ -11545,7 +11707,8 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 		}
 	    }
 	}
-    } else { /* type == MON_TARGET */
+	break;
+    case MON_TARGET:
 	ASSERT(mon->type == MON_TARGET);
 	ASSERT(is_pid(mon->pid) || is_internal_port(mon->pid));
 	if (is_internal_port(mon->pid)) {
@@ -11604,6 +11767,12 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 		}
 	    }
 	}
+	break;
+    case MON_TIME_OFFSET:
+	erts_demonitor_time_offset(mon->ref);
+	break;
+    default:
+	ERTS_INTERNAL_ERROR("Invalid monitor type");
     }
  done:
     /* As the monitors are previously removed from the process, 
@@ -11762,6 +11931,9 @@ erts_do_exit_process(Process* p, Eterm reason)
     }
 #endif
 
+    if (p->static_flags & ERTS_STC_FLG_SYSTEM_PROC)
+	erl_exit(1, "System process %T terminated: %T\n", p->common.id, reason);
+
 #ifdef ERTS_SMP
     ERTS_SMP_CHK_HAVE_ONLY_MAIN_PROC_LOCK(p);
     /* By locking all locks (main lock is already locked) when going
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index d12ac792af..743711cc3b 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -348,7 +348,7 @@ typedef struct {
 } ErtsRunQueueInfo;
 
 
-#ifdef HAVE_GETHRTIME
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
 #  undef ERTS_HAVE_SCHED_UTIL_BALANCING_SUPPORT_OPT
 #  define ERTS_HAVE_SCHED_UTIL_BALANCING_SUPPORT_OPT 1
 #endif
@@ -564,6 +564,8 @@ struct ErtsSchedulerData_ {
     Eterm* x_reg_array;		/* X registers */
     FloatDef* f_reg_array;	/* Floating point registers. */
 
+    ErtsTimerWheel *timer_wheel;
+    ErtsNextTimeoutRef next_tmo_ref;
 #ifdef ERTS_SMP
     ethr_tid tid;		/* Thread id */
     struct erl_bits_state erl_bits_state; /* erl_bits.c state */
@@ -590,6 +592,10 @@ struct ErtsSchedulerData_ {
     ErtsAuxWorkData aux_work_data;
     ErtsAtomCacheMap atom_cache_map;
 
+    Uint32 thr_id;
+    Uint64 unique;
+    Uint64 ref;
+
     ErtsSchedAllocData alloc_data;
 
     Uint64 reductions;
@@ -936,6 +942,8 @@ struct process {
     Eterm parent;		/* Pid of process that created this process. */
     erts_approx_time_t approx_started; /* Time when started. */
 
+    Uint32 static_flags;        /* Flags that do *not* change */
+
     /* This is the place, where all fields that differs between memory
      * architectures, have gone to.
      */
@@ -967,6 +975,7 @@ struct process {
     ErtsSchedulerData *scheduler_data;
     Eterm suspendee;
     ErtsPendingSuspend *pending_suspenders;
+    ErtsRunQueue *preferred_run_queue;
     erts_smp_atomic_t run_queue;
 #ifdef HIPE
     struct hipe_process_state_smp hipe_smp;
@@ -1076,14 +1085,15 @@ void erts_check_for_holes(Process* p);
 #define ERTS_PSFLG_RUNNING_SYS		ERTS_PSFLG_BIT(15)
 #define ERTS_PSFLG_PROXY		ERTS_PSFLG_BIT(16)
 #define ERTS_PSFLG_DELAYED_SYS		ERTS_PSFLG_BIT(17)
+#define ERTS_PSFLG_OFF_HEAP_MSGS	ERTS_PSFLG_BIT(18)
 #ifdef ERTS_DIRTY_SCHEDULERS
-#define ERTS_PSFLG_DIRTY_CPU_PROC	ERTS_PSFLG_BIT(18)
-#define ERTS_PSFLG_DIRTY_IO_PROC	ERTS_PSFLG_BIT(19)
-#define ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q	ERTS_PSFLG_BIT(20)
-#define ERTS_PSFLG_DIRTY_IO_PROC_IN_Q	ERTS_PSFLG_BIT(21)
-#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 22)
+#define ERTS_PSFLG_DIRTY_CPU_PROC	ERTS_PSFLG_BIT(19)
+#define ERTS_PSFLG_DIRTY_IO_PROC	ERTS_PSFLG_BIT(20)
+#define ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q	ERTS_PSFLG_BIT(21)
+#define ERTS_PSFLG_DIRTY_IO_PROC_IN_Q	ERTS_PSFLG_BIT(22)
+#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 23)
 #else
-#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 18)
+#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 19)
 #endif
 
 #define ERTS_PSFLGS_IN_PRQ_MASK 	(ERTS_PSFLG_IN_PRQ_MAX		\
@@ -1098,6 +1108,12 @@ void erts_check_for_holes(Process* p);
 #define ERTS_PSFLGS_GET_PRQ_PRIO(PSFLGS) \
     (((PSFLGS) >> ERTS_PSFLGS_USR_PRIO_OFFSET) & ERTS_PSFLGS_PRIO_MASK)
 
+/*
+ * Static flags that do not change after process creation.
+ */
+#define ERTS_STC_FLG_SYSTEM_PROC	(((Uint32) 1) << 0)
+#define ERTS_STC_FLG_PREFER_SCHED	(((Uint32) 1) << 1)
+
 /* The sequential tracing token is a tuple of size 5:
  *
  *    {Flags, Label, Serial, Sender}
@@ -1125,6 +1141,9 @@ void erts_check_for_holes(Process* p);
 #define SPO_LINK 1
 #define SPO_USE_ARGS 2
 #define SPO_MONITOR 4
+#define SPO_OFF_HEAP_MSGS 8
+#define SPO_SYSTEM_PROC 16
+#define SPO_PREFER_SCHED 32
 
 /*
  * The following struct contains options for a process to be spawned.
@@ -1212,6 +1231,7 @@ extern struct erts_system_profile_flags_t erts_system_profile_flags;
 #define F_P2PNR_RESCHED      (1 <<  9) /* Process has been rescheduled via erts_pid2proc_not_running() */
 #define F_FORCE_GC           (1 << 10) /* Force gc at process in-scheduling */
 #define F_DISABLE_GC         (1 << 11) /* Disable GC */
+#define F_OFF_HEAP_MSGS      (1 << 12)
 
 /* process trace_flags */
 #define F_SENSITIVE          (1 << 0)
@@ -2228,6 +2248,8 @@ extern int erts_disable_proc_not_running_opt;
 
 void erts_smp_notify_inc_runq(ErtsRunQueue *runq);
 
+void erts_interupt_aux_thread_timed(ErtsMonotonicTime timeout_time);
+
 #ifdef ERTS_SMP
 void erts_sched_finish_poke(ErtsSchedulerSleepInfo *, erts_aint32_t);
 ERTS_GLB_INLINE void erts_sched_poke(ErtsSchedulerSleepInfo *ssi);
diff --git a/erts/emulator/beam/erl_thr_progress.c b/erts/emulator/beam/erl_thr_progress.c
index c2365c5cf7..4c9b00d2ee 100644
--- a/erts/emulator/beam/erl_thr_progress.c
+++ b/erts/emulator/beam/erl_thr_progress.c
@@ -1359,18 +1359,16 @@ void
 erts_thr_progress_fatal_error_wait(SWord timeout) {
     erts_aint32_t bc;
     SWord time_left = timeout;
-    SysTimeval to;
+    ErtsMonotonicTime timeout_time;
 
     /*
      * Counting poll intervals may give us a too long timeout
-     * if cpu is busy. If we got tolerant time of day we use it
-     * to prevent this.
+     * if cpu is busy. We use timeout time to try to prevent
+     * this. In case we havn't got time correction this may
+     * however fail too...
      */
-    if (!erts_disable_tolerant_timeofday) {
-        erts_get_timeval(&to);
-        to.tv_sec += timeout / 1000;
-        to.tv_sec += timeout % 1000;
-    }
+    timeout_time = erts_get_monotonic_time();
+    timeout_time += ERTS_MSEC_TO_MONOTONIC((ErtsMonotonicTime) timeout);
 
     while (1) {
 	if (erts_milli_sleep(ERTS_THR_PRGR_FTL_ERR_BLCK_POLL_INTERVAL) == 0)
@@ -1380,14 +1378,8 @@ erts_thr_progress_fatal_error_wait(SWord timeout) {
 	    break; /* Succefully blocked all managed threads */
 	if (time_left <= 0)
 	    break; /* Timeout */
-	if (!erts_disable_tolerant_timeofday) {
-	    SysTimeval now;
-	    erts_get_timeval(&now);
-	    if (now.tv_sec > to.tv_sec)
-		break; /* Timeout */
-	    if (now.tv_sec == to.tv_sec && now.tv_usec >= to.tv_usec)
-		break; /* Timeout */
-	}
+	if (timeout_time <= erts_get_monotonic_time())
+	    break; /* Timeout */
     }
 }
 
diff --git a/erts/emulator/beam/erl_threads.h b/erts/emulator/beam/erl_threads.h
index 1fd800d524..dc20ac207f 100644
--- a/erts/emulator/beam/erl_threads.h
+++ b/erts/emulator/beam/erl_threads.h
@@ -652,6 +652,8 @@ ERTS_GLB_INLINE void erts_tse_set(erts_tse_t *ep);
 ERTS_GLB_INLINE void erts_tse_reset(erts_tse_t *ep);
 ERTS_GLB_INLINE int erts_tse_wait(erts_tse_t *ep);
 ERTS_GLB_INLINE int erts_tse_swait(erts_tse_t *ep, int spincount);
+ERTS_GLB_INLINE int erts_tse_twait(erts_tse_t *ep, Sint64 tmo);
+ERTS_GLB_INLINE int erts_tse_stwait(erts_tse_t *ep, int spincount, Sint64 tmo);
 ERTS_GLB_INLINE int erts_tse_is_tmp(erts_tse_t *ep);
 ERTS_GLB_INLINE void erts_thr_set_main_status(int, int);
 ERTS_GLB_INLINE int erts_thr_get_main_status(void);
@@ -3490,6 +3492,27 @@ ERTS_GLB_INLINE int erts_tse_swait(erts_tse_t *ep, int spincount)
 #endif
 }
 
+ERTS_GLB_INLINE int erts_tse_twait(erts_tse_t *ep, Sint64 tmo)
+{
+#ifdef USE_THREADS
+    return ethr_event_twait(&((ethr_ts_event *) ep)->event,
+			    (ethr_sint64_t) tmo);
+#else
+    return ENOTSUP;
+#endif
+}
+
+ERTS_GLB_INLINE int erts_tse_stwait(erts_tse_t *ep, int spincount, Sint64 tmo)
+{
+#ifdef USE_THREADS
+    return ethr_event_stwait(&((ethr_ts_event *) ep)->event,
+			     spincount,
+			     (ethr_sint64_t) tmo);
+#else
+    return ENOTSUP;
+#endif
+}
+
 ERTS_GLB_INLINE int erts_tse_is_tmp(erts_tse_t *ep)
 {
 #ifdef USE_THREADS
diff --git a/erts/emulator/beam/erl_time.h b/erts/emulator/beam/erl_time.h
index 7ed1a395ad..f201a8b4e3 100644
--- a/erts/emulator/beam/erl_time.h
+++ b/erts/emulator/beam/erl_time.h
@@ -20,11 +20,16 @@
 #ifndef ERL_TIME_H__
 #define ERL_TIME_H__
 
-#define ERTS_SHORT_TIME_T_MAX ERTS_AINT32_T_MAX
-#define ERTS_SHORT_TIME_T_MIN ERTS_AINT32_T_MIN
-typedef erts_aint32_t erts_short_time_t;
+#if defined(DEBUG) || 0
+#define ERTS_TIME_ASSERT(B) ERTS_ASSERT(B)
+#else
+#define ERTS_TIME_ASSERT(B) ((void) 1)
+#endif
+
+typedef struct ErtsTimerWheel_ ErtsTimerWheel;
+typedef erts_atomic64_t * ErtsNextTimeoutRef;
+extern ErtsTimerWheel *erts_default_timer_wheel;
 
-extern erts_smp_atomic32_t do_time;	/* set at clock interrupt */
 extern SysTimeval erts_first_emu_time;
 
 /*
@@ -34,8 +39,8 @@ typedef struct erl_timer {
     struct erl_timer* next;	/* next entry tiw slot or chain */
     struct erl_timer* prev;	/* prev entry tiw slot or chain */
     Uint slot;			/* slot in timer wheel */
-    Uint count;			/* number of loops remaining */
-    int    active;		/* 1=activated, 0=deactivated */
+    erts_smp_atomic_t wheel;
+    ErtsMonotonicTime timeout_pos; /* Timeout in absolute clock ticks */
     /* called when timeout */
     void (*timeout)(void*);
     /* called when cancel (may be NULL) */
@@ -62,7 +67,6 @@ union ErtsSmpPTimer_ {
     ErtsSmpPTimer *next;
 };
 
-
 void erts_create_smp_ptimer(ErtsSmpPTimer **timer_ref,
 			    Eterm id,
 			    ErlTimeoutProc timeout_func,
@@ -70,36 +74,43 @@ void erts_create_smp_ptimer(ErtsSmpPTimer **timer_ref,
 void erts_cancel_smp_ptimer(ErtsSmpPTimer *ptimer);
 #endif
 
+void erts_monitor_time_offset(Eterm id, Eterm ref);
+int erts_demonitor_time_offset(Eterm ref);
+
+void erts_early_init_time_sup(void);
+void erts_late_init_time_sup(void);
+
 /* timer-wheel api */
 
-void erts_init_time(void);
+ErtsTimerWheel *erts_create_timer_wheel(int);
+ErtsNextTimeoutRef erts_get_next_timeout_reference(ErtsTimerWheel *);
+void erts_init_time(int time_correction, ErtsTimeWarpMode time_warp_mode);
 void erts_set_timer(ErlTimer*, ErlTimeoutProc, ErlCancelProc, void*, Uint);
 void erts_cancel_timer(ErlTimer*);
-void erts_bump_timer(erts_short_time_t);
-Uint erts_timer_wheel_memory_size(void);
 Uint erts_time_left(ErlTimer *);
-erts_short_time_t erts_next_time(void);
+void erts_bump_timers(ErtsTimerWheel *, ErtsMonotonicTime);
+Uint erts_timer_wheel_memory_size(void);
 
 #ifdef DEBUG
 void erts_p_slpq(void);
 #endif
 
-ERTS_GLB_INLINE erts_short_time_t erts_do_time_read_and_reset(void);
-ERTS_GLB_INLINE void erts_do_time_add(erts_short_time_t);
+ErtsMonotonicTime erts_check_next_timeout_time(ErtsTimerWheel *,
+					       ErtsMonotonicTime);
+
+ERTS_GLB_INLINE void erts_init_timer(ErlTimer *p);
+ERTS_GLB_INLINE ErtsMonotonicTime erts_next_timeout_time(ErtsNextTimeoutRef);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
-ERTS_GLB_INLINE erts_short_time_t erts_do_time_read_and_reset(void)
+ERTS_GLB_INLINE void erts_init_timer(ErlTimer *p)
 {
-    erts_short_time_t time = erts_smp_atomic32_xchg_acqb(&do_time, 0);
-    if (time < 0)
-	erl_exit(ERTS_ABORT_EXIT, "Internal time management error\n");
-    return time;
+    erts_smp_atomic_init_nob(&p->wheel, (erts_aint_t) NULL);
 }
 
-ERTS_GLB_INLINE void erts_do_time_add(erts_short_time_t elapsed)
+ERTS_GLB_INLINE ErtsMonotonicTime erts_next_timeout_time(ErtsNextTimeoutRef nxt_tmo_ref)
 {
-    erts_smp_atomic32_add_relb(&do_time, elapsed);
+    return (ErtsMonotonicTime) erts_atomic64_read_acqb((erts_atomic64_t *) nxt_tmo_ref);
 }
 
 #endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
@@ -121,25 +132,228 @@ void erts_get_now_cpu(Uint* megasec, Uint* sec, Uint* microsec);
 typedef UWord erts_approx_time_t;
 erts_approx_time_t erts_get_approx_time(void);
 
-void erts_get_timeval(SysTimeval *tv);
-erts_time_t erts_get_time(void);
+int erts_has_time_correction(void);
+int erts_check_time_adj_support(int time_correction,
+				ErtsTimeWarpMode time_warp_mode);
+
+ErtsTimeWarpMode erts_time_warp_mode(void);
+
+typedef enum {
+    ERTS_TIME_OFFSET_PRELIMINARY,
+    ERTS_TIME_OFFSET_FINAL,
+    ERTS_TIME_OFFSET_VOLATILE
+} ErtsTimeOffsetState;
+
+ErtsTimeOffsetState erts_time_offset_state(void); 
+ErtsTimeOffsetState erts_finalize_time_offset(void); 
+struct process;
+Eterm erts_get_monotonic_start_time(struct process *c_p);
+Eterm erts_monotonic_time_source(struct process*c_p);
+
+#ifdef SYS_CLOCK_RESOLUTION
+#define ERTS_CLKTCK_RESOLUTION ((ErtsMonotonicTime) (SYS_CLOCK_RESOLUTION*1000))
+#else
+#define ERTS_CLKTCK_RESOLUTION (erts_time_sup__.r.o.clktck_resolution)
+#endif
+
+struct erts_time_sup_read_only__ {
+    ErtsMonotonicTime monotonic_time_unit;
+#ifndef SYS_CLOCK_RESOLUTION
+    ErtsMonotonicTime clktck_resolution;
+#endif
+};
+
+typedef struct {
+    union {
+	struct erts_time_sup_read_only__ o;
+	char align__[(((sizeof(struct erts_time_sup_read_only__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } r;
+} ErtsTimeSupData;
+
+extern ErtsTimeSupData erts_time_sup__;
 
-ERTS_GLB_INLINE int erts_cmp_timeval(SysTimeval *t1p, SysTimeval *t2p);
+ERTS_GLB_INLINE Uint64
+erts_time_unit_conversion(Uint64 value,
+			  Uint32 from_time_unit,
+			  Uint32 to_time_unit);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
-ERTS_GLB_INLINE int
-erts_cmp_timeval(SysTimeval *t1p, SysTimeval *t2p)
+ERTS_GLB_INLINE Uint64
+erts_time_unit_conversion(Uint64 value,
+			  Uint32 from_time_unit,
+			  Uint32 to_time_unit)
 {
-    if (t1p->tv_sec == t2p->tv_sec) {
-	if (t1p->tv_usec < t2p->tv_usec)
-	    return -1;
-	else if (t1p->tv_usec > t2p->tv_usec)
-	    return 1;
-	return 0;
-    }
-    return t1p->tv_sec < t2p->tv_sec ? -1 : 1;
+    Uint64 high, low, result;
+    if (value <= ~((Uint64) 0)/to_time_unit)
+	return (value*to_time_unit)/from_time_unit;
+
+    low = value & ((Uint64) 0xffffffff);
+    high = (value >> 32) & ((Uint64) 0xffffffff);
+
+    low *= to_time_unit;
+    high *= to_time_unit;
+
+    high += (low >> 32) & ((Uint64) 0xffffffff);
+    low &= ((Uint64) 0xffffffff);
+
+    result = high % from_time_unit;
+    high /= from_time_unit;
+    high <<= 32;
+
+    result <<= 32;
+    result += low;
+    result /= from_time_unit;
+    result += high;
+
+    return result;
 }
 
-#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+
+/*
+ * If the monotonic time unit is a compile time constant,
+ * it is assumed (and need) to be a power of 10.
+ */
+
+#define ERTS_MONOTONIC_TIME_UNIT \
+    ((ErtsMonotonicTime) ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT)
+
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT == 1000*1000*1000
+/* Nano-second time unit */
+
+#define ERTS_MONOTONIC_TO_SEC__(NSEC) ((NSEC) / (1000*1000*1000))
+#define ERTS_MONOTONIC_TO_MSEC__(NSEC) ((NSEC) / (1000*1000))
+#define ERTS_MONOTONIC_TO_USEC__(NSEC) ((NSEC) / 1000)
+#define ERTS_MONOTONIC_TO_NSEC__(NSEC) (NSEC)
+
+#define ERTS_SEC_TO_MONOTONIC__(SEC) (((ErtsMonotonicTime) (SEC))*(1000*1000*1000))
+#define ERTS_MSEC_TO_MONOTONIC__(MSEC) (((ErtsMonotonicTime) (MSEC))*(1000*1000))
+#define ERTS_USEC_TO_MONOTONIC__(USEC) (((ErtsMonotonicTime) (USEC))*1000)
+#define ERTS_NSEC_TO_MONOTONIC__(NSEC) ((ErtsMonotonicTime) (NSEC))
+
+#elif ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT == 1000*1000
+/* Micro-second time unit */
+
+#define ERTS_MONOTONIC_TO_SEC__(USEC) ((USEC) / (1000*1000))
+#define ERTS_MONOTONIC_TO_MSEC__(USEC) ((USEC) / 1000)
+#define ERTS_MONOTONIC_TO_USEC__(USEC) (USEC)
+#define ERTS_MONOTONIC_TO_NSEC__(USEC) ((USEC)*1000)
+
+#define ERTS_SEC_TO_MONOTONIC__(SEC) (((ErtsMonotonicTime) (SEC))*(1000*1000))
+#define ERTS_MSEC_TO_MONOTONIC__(MSEC) (((ErtsMonotonicTime) (MSEC))*1000)
+#define ERTS_USEC_TO_MONOTONIC__(USEC) ((ErtsMonotonicTime) (USEC))
+#define ERTS_NSEC_TO_MONOTONIC__(NSEC) (((ErtsMonotonicTime) (NSEC))/1000)
+
+#elif ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT == 1000
+/* Milli-second time unit */
+
+#define ERTS_MONOTONIC_TO_SEC__(MSEC) ((USEC)/(1000))
+#define ERTS_MONOTONIC_TO_MSEC__(MSEC) (MSEC)
+#define ERTS_MONOTONIC_TO_USEC__(MSEC) ((MSEC)*1000)
+#define ERTS_MONOTONIC_TO_NSEC__(MSEC) ((MSEC)*(1000*1000))
+
+#define ERTS_SEC_TO_MONOTONIC__(SEC) (((ErtsMonotonicTime) (SEC))*1000)
+#define ERTS_MSEC_TO_MONOTONIC__(MSEC) ((ErtsMonotonicTime) (MSEC))
+#define ERTS_USEC_TO_MONOTONIC__(USEC) (((ErtsMonotonicTime) (USEC))/1000)
+#define ERTS_NSEC_TO_MONOTONIC__(NSEC) (((ErtsMonotonicTime) (NSEC))/(1000*1000))
+
+#else
+#error Missing implementation for monotonic time unit
+#endif
+
+#define ERTS_MONOTONIC_TO_CLKTCKS__(MON) \
+    ((MON) / (ERTS_MONOTONIC_TIME_UNIT/ERTS_CLKTCK_RESOLUTION))
+#define ERTS_CLKTCKS_TO_MONOTONIC__(TCKS) \
+    ((TCKS) * (ERTS_MONOTONIC_TIME_UNIT/ERTS_CLKTCK_RESOLUTION))
+
+#else /* !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT */
+
+#define ERTS_MONOTONIC_TIME_UNIT (erts_time_sup__.r.o.monotonic_time_unit)
+
+#define ERTS_CONV_FROM_MON_UNIT___(M, TO)				\
+    ((ErtsMonotonicTime)						\
+     erts_time_unit_conversion((Uint64) (M),				\
+			       (Uint32) ERTS_MONOTONIC_TIME_UNIT,	\
+			       (Uint32) (TO)))
+
+#define ERTS_CONV_TO_MON_UNIT___(M, FROM)				\
+    ((ErtsMonotonicTime)						\
+     erts_time_unit_conversion((Uint64) (M),				\
+			       (Uint32) (FROM),				\
+			       (Uint32) ERTS_MONOTONIC_TIME_UNIT))	\
+
+#define ERTS_MONOTONIC_TO_SEC__(M) \
+    ERTS_CONV_FROM_MON_UNIT___((M), 1)
+#define ERTS_MONOTONIC_TO_MSEC__(M) \
+    ERTS_CONV_FROM_MON_UNIT___((M), 1000)
+#define ERTS_MONOTONIC_TO_USEC__(M) \
+    ERTS_CONV_FROM_MON_UNIT___((M), 1000*1000)
+#define ERTS_MONOTONIC_TO_NSEC__(M) \
+    ERTS_CONV_FROM_MON_UNIT___((M), 1000*1000*1000)
+
+#define ERTS_SEC_TO_MONOTONIC__(SEC) \
+    ERTS_CONV_TO_MON_UNIT___((SEC), 1)
+#define ERTS_MSEC_TO_MONOTONIC__(MSEC) \
+    ERTS_CONV_TO_MON_UNIT___((MSEC), 1000)
+#define ERTS_USEC_TO_MONOTONIC__(USEC) \
+    ERTS_CONV_TO_MON_UNIT___((USEC), 1000*1000)
+#define ERTS_NSEC_TO_MONOTONIC__(NSEC) \
+    ERTS_CONV_TO_MON_UNIT___((NSEC), 1000*1000*1000)
+
+#define ERTS_MONOTONIC_TO_CLKTCKS__(MON) \
+    ERTS_CONV_FROM_MON_UNIT___((MON), ERTS_CLKTCK_RESOLUTION)
+#define ERTS_CLKTCKS_TO_MONOTONIC__(TCKS) \
+    ERTS_CONV_TO_MON_UNIT___((TCKS), ERTS_CLKTCK_RESOLUTION)
+
+#endif /* !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT */
+
+#define ERTS_MSEC_TO_CLKTCKS__(MON) \
+    ((MON) * (ERTS_CLKTCK_RESOLUTION/1000))
+#define ERTS_CLKTCKS_TO_MSEC__(TCKS) \
+    ((TCKS) / (ERTS_CLKTCK_RESOLUTION/1000))
+
+#define ERTS_MONOTONIC_TO_SEC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MONOTONIC_TO_SEC__((X)))
+#define ERTS_MONOTONIC_TO_MSEC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MONOTONIC_TO_MSEC__((X)))
+#define ERTS_MONOTONIC_TO_USEC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MONOTONIC_TO_USEC__((X)))
+#define ERTS_MONOTONIC_TO_NSEC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MONOTONIC_TO_NSEC__((X)))
+#define ERTS_SEC_TO_MONOTONIC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_SEC_TO_MONOTONIC__((X)))
+#define ERTS_MSEC_TO_MONOTONIC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MSEC_TO_MONOTONIC__((X)))
+#define ERTS_USEC_TO_MONOTONIC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_USEC_TO_MONOTONIC__((X)))
+#define ERTS_NSEC_TO_MONOTONIC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_NSEC_TO_MONOTONIC__((X)))
+
+#define ERTS_MONOTONIC_TO_CLKTCKS(X) \
+    (ERTS_TIME_ASSERT((X) >= 0),		\
+     ERTS_MONOTONIC_TO_CLKTCKS__((X)))
+#define ERTS_CLKTCKS_TO_MONOTONIC(X) \
+    (ERTS_TIME_ASSERT((X) >= 0),		\
+     ERTS_CLKTCKS_TO_MONOTONIC__((X)))
+
+#define ERTS_MSEC_TO_CLKTCKS(X) \
+    (ERTS_TIME_ASSERT((X) >= 0),		\
+     ERTS_MSEC_TO_CLKTCKS__((X)))
+#define ERTS_CLKTCKS_TO_MSEC(X) \
+    (ERTS_TIME_ASSERT((X) >= 0),		\
+     ERTS_CLKTCKS_TO_MSEC__((X)))
+
 #endif /* ERL_TIME_H__ */
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c
index 3272a5326d..d47d1682d7 100644
--- a/erts/emulator/beam/erl_time_sup.c
+++ b/erts/emulator/beam/erl_time_sup.c
@@ -18,60 +18,8 @@
  */
 
 /*
-** Support routines for the timer wheel
-**
-** This code contains two strategies for dealing with 
-** date/time changes in the system. 
-** If the system has some kind of high resolution timer (HAVE_GETHRTIME),
-** the high resolution timer is used to correct the time-of-day and the
-** timeouts, the base source is the hrtimer, but at certain intervals the 
-** OS time-of-day is checked and if it is not within certain bounds, the 
-** delivered time gets slowly adjusted for each call until
-** it corresponds to the system time (built-in adjtime...). 
-** The call gethrtime() is detected by autoconf on Unix, but other 
-** platforms may define it in erl_*_sys.h and implement 
-** their own high resolution timer. The high resolution timer
-** strategy is (probably) best on all systems where the timer have 
-** a resolution higher or equal to gettimeofday (or what's implemented
-** is sys_gettimeofday()). The actual resolution is the interesting thing,
-** not the unit's thats used (i.e. on VxWorks, nanoseconds can be
-** retrieved in terms of units, but the actual resolution is the same as 
-** for the clock ticks).
-** If the systems best timer routine is kernel ticks returned from 
-** sys_times(), and the actual resolution of sys_gettimeofday() is
-** better (like most unixes that does not have any realtime extensions), 
-** another strategy is used. The tolerant gettimeofday() corrects 
-** the value with respect to uptime (sys_times() return value) and checks 
-** for correction both when delivering timeticks and delivering nowtime.
-** this strategy is slower, but accurate on systems without better timer 
-** routines. The kernel tick resolution is not enough to implement
-** a gethrtime routine. On Linux and other non solaris unix-boxes the second 
-** strategy is used, on all other platforms we use the first.
-** 
-** The following is expected (from sys.[ch] and erl_*_sys.h):
-**
-** 64 bit integers. So it is, and so it will be.
-**
-** sys_init_time(), will return the clock resolution in MS and
-** that's about it. More could be added of course
-** If the clock-rate is constant (i.e. 1 ms) one can define 
-** SYS_CLOCK_RESOLUTION (to 1),
-** which makes erts_deliver_time/erts_time_remaining a bit faster.
-**
-** if HAVE_GETHRTIME is defined:
-**    sys_gethrtime() will return a SysHrTime (long long) representing 
-**    nanoseconds, sys_init_hrtime() will do any initialization.
-** else
-**    a long (64bit) integer type called Sint64 should be defined.
-**
-** sys_times() will return clock_ticks since start and 
-**    fill in a SysTimes structure (struct tms). Instead of CLK_TCK, 
-**    SYS_CLK_TCK is used to determine the resolution of kernel ticks.
-**
-** sys_gettimeofday() will take a SysTimeval (a struct timeval) as parameter
-**    and fill it in as gettimeofday(X,NULL).
-**
-*/
+ * Support routines for the time
+ */
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -80,384 +28,1029 @@
 #include "sys.h"
 #include "erl_vm.h"
 #include "global.h"
-
+ 
 static erts_smp_mtx_t erts_timeofday_mtx;
-
-static SysTimeval inittv; /* Used everywhere, the initial time-of-day */
+static erts_smp_mtx_t erts_get_time_mtx;
 
 static SysTimes t_start; /* Used in elapsed_time_both */
-static SysTimeval gtv; /* Used in wall_clock_elapsed_time_both */
-static SysTimeval then; /* Used in get_now */
-static SysTimeval last_emu_time; /* Used in erts_get_emu_time() */
-SysTimeval erts_first_emu_time; /* Used in erts_get_emu_time() */
+static ErtsMonotonicTime prev_wall_clock_elapsed; /* Used in wall_clock_elapsed_time_both */
+static ErtsMonotonicTime previous_now; /* Used in get_now */
+
+static ErtsMonitor *time_offset_monitors = NULL;
+static Uint no_time_offset_monitors = 0;
 
-union {
-    erts_smp_atomic_t time;
-    char align[ERTS_CACHE_LINE_SIZE];
-} approx erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+#ifdef DEBUG
+static int time_sup_initialized = 0;
+#endif
+
+#define ERTS_MONOTONIC_TIME_KILO \
+    ((ErtsMonotonicTime) 1000)
+#define ERTS_MONOTONIC_TIME_MEGA \
+    (ERTS_MONOTONIC_TIME_KILO*ERTS_MONOTONIC_TIME_KILO)
+#define ERTS_MONOTONIC_TIME_GIGA \
+    (ERTS_MONOTONIC_TIME_MEGA*ERTS_MONOTONIC_TIME_KILO)
+#define ERTS_MONOTONIC_TIME_TERA \
+    (ERTS_MONOTONIC_TIME_GIGA*ERTS_MONOTONIC_TIME_KILO)
 
 static void
-init_approx_time(void)
+schedule_send_time_offset_changed_notifications(ErtsMonotonicTime new_offset);
+
+/*
+ * NOTE! ERTS_MONOTONIC_TIME_START *need* to be a multiple
+ *       of ERTS_MONOTONIC_TIME_UNIT.
+ */
+
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+
+#ifdef ARCH_32
+/*
+ * Want to use a big-num of arity 2 as long as possible (584 years
+ * in the nano-second time unit case).
+ */
+#define ERTS_MONOTONIC_TIME_START		\
+    (((((((ErtsMonotonicTime) 1) << 32)-1)	\
+       / ERTS_MONOTONIC_TIME_UNIT)		\
+      * ERTS_MONOTONIC_TIME_UNIT)		\
+     + ERTS_MONOTONIC_TIME_UNIT)
+
+#else /* ARCH_64 */
+
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT <= 1000*1000
+
+/*
+ * Using micro second time unit or lower. Start at zero since
+ * time will remain an immediate for a very long time anyway
+ * (18279 years in the micro second case)...
+ */
+#define ERTS_MONOTONIC_TIME_START ((ErtsMonotonicTime) 0)
+
+#else /* ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT > 1000*1000 */
+
+/*
+ * Want to use an immediate as long as possible (36 years in the
+ * nano-second time unit case).
+*/
+#define ERTS_MONOTONIC_TIME_START 		\
+    ((((ErtsMonotonicTime) MIN_SMALL)		\
+      / ERTS_MONOTONIC_TIME_UNIT)		\
+     * ERTS_MONOTONIC_TIME_UNIT)
+
+#endif /* ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT > 1000*1000 */
+
+#endif /* ARCH_64 */
+
+#define ERTS_MONOTONIC_OFFSET_NATIVE ERTS_MONOTONIC_TIME_START
+#define ERTS_MONOTONIC_OFFSET_NSEC ERTS_MONOTONIC_TO_NSEC__(ERTS_MONOTONIC_TIME_START)
+#define ERTS_MONOTONIC_OFFSET_USEC ERTS_MONOTONIC_TO_USEC__(ERTS_MONOTONIC_TIME_START)
+#define ERTS_MONOTONIC_OFFSET_MSEC ERTS_MONOTONIC_TO_MSEC__(ERTS_MONOTONIC_TIME_START)
+#define ERTS_MONOTONIC_OFFSET_SEC ERTS_MONOTONIC_TO_SEC__(ERTS_MONOTONIC_TIME_START)
+
+#else /* ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT */
+
+/*
+ * Initialized in erts_init_time_sup()...
+ */
+
+#define ERTS_MONOTONIC_TIME_START (time_sup.r.o.start)
+#define ERTS_MONOTONIC_OFFSET_NATIVE (time_sup.r.o.start_offset.native)
+#define ERTS_MONOTONIC_OFFSET_NSEC (time_sup.r.o.start_offset.nsec)
+#define ERTS_MONOTONIC_OFFSET_USEC (time_sup.r.o.start_offset.usec)
+#define ERTS_MONOTONIC_OFFSET_MSEC (time_sup.r.o.start_offset.msec)
+#define ERTS_MONOTONIC_OFFSET_SEC (time_sup.r.o.start_offset.sec)
+
+#endif /* ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT */
+
+#define ERTS_MONOTONIC_TO_SYS_TIME_VAL(TVP, MT)				\
+    do {								\
+	ErtsMonotonicTime sec__, usec__;				\
+	sec__ = ERTS_MONOTONIC_TO_SEC((MT));				\
+	usec__ = ERTS_MONOTONIC_TO_USEC((MT)) - sec__*1000000;		\
+	ASSERT(usec__ < 1000000);					\
+	(TVP)->tv_sec = sec__;						\
+	(TVP)->tv_usec = usec__;					\
+    } while (0)
+
+#define ERTS_MAX_SYSTEM_TIME_DIFF ERTS_MSEC_TO_MONOTONIC(10)
+#define ERTS_SYSTEM_TIME_DIFF_EXCEED_LIMIT(ESYSTIME, OSSYSTIME)		\
+    (((Uint64) (ESYSTIME)) - (((Uint64) (OSSYSTIME))			\
+			      - ERTS_MAX_SYSTEM_TIME_DIFF)		\
+     > 2*ERTS_MAX_SYSTEM_TIME_DIFF)
+
+#define ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF (ERTS_MAX_SYSTEM_TIME_DIFF/2)
+#define ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF ERTS_USEC_TO_MONOTONIC(500)
+
+struct time_sup_read_only__ {
+    ErtsMonotonicTime (*get_time)(void);
+    int correction;
+    ErtsTimeWarpMode warp_mode;
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    ErtsMonotonicTime moffset;
+    int os_monotonic_disable;
+    char *os_monotonic_func;
+    char *os_monotonic_clock_id;
+    int os_monotonic_locked;
+    Uint64 os_monotonic_resolution;
+#endif
+#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+    ErtsMonotonicTime start;
+    struct {
+	ErtsMonotonicTime native;
+	ErtsMonotonicTime nsec;
+	ErtsMonotonicTime usec;
+	ErtsMonotonicTime msec;
+	ErtsMonotonicTime sec;
+    } start_offset;
+#endif
+};
+
+typedef struct {
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+    ErtsMonotonicTime drift; /* Correction for os monotonic drift */
+#endif
+    ErtsMonotonicTime error; /* Correction for error between system times */
+} ErtsMonotonicCorrection;
+
+typedef struct {
+    ErtsMonotonicTime erl_mtime;
+    ErtsMonotonicTime os_mtime;
+    ErtsMonotonicCorrection correction;
+} ErtsMonotonicCorrectionInstance;
+
+#define ERTS_DRIFT_INTERVALS 5
+typedef struct {
+    struct {
+	struct {
+	    ErtsMonotonicTime sys;
+	    ErtsMonotonicTime mon;
+	} diff;
+	struct {
+	    ErtsMonotonicTime sys;
+	    ErtsMonotonicTime mon;
+	} time;
+    } intervals[ERTS_DRIFT_INTERVALS];
+    struct {
+	ErtsMonotonicTime sys;
+	ErtsMonotonicTime mon;
+    } acc;
+    int ix;
+    int dirty_counter;
+} ErtsMonotonicDriftData;
+
+typedef struct {
+    ErtsMonotonicCorrectionInstance prev;
+    ErtsMonotonicCorrectionInstance curr;    
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+    ErtsMonotonicDriftData drift;
+#endif
+    ErtsMonotonicTime last_check;
+    int short_check_interval;
+} ErtsMonotonicCorrectionData;
+
+struct time_sup_infrequently_changed__ {
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    struct {
+	erts_smp_rwmtx_t rwmtx;
+	ErlTimer timer;
+	ErtsMonotonicCorrectionData cdata;
+    } parmon;
+    ErtsMonotonicTime minit;
+#endif
+    int finalized_offset;
+    SysTimeval inittv; /* Used everywhere, the initial time-of-day */
+    ErtsMonotonicTime not_corrected_moffset;
+    erts_atomic64_t offset;
+};
+
+struct time_sup_frequently_changed__ {
+    ErtsMonotonicTime last_not_corrected_time;
+};
+
+static struct {
+    union {
+	struct time_sup_read_only__ o;
+	char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(struct time_sup_read_only__))];
+    } r;
+    union {
+	struct time_sup_infrequently_changed__ c;
+	char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(struct time_sup_infrequently_changed__))];
+    } inf;
+    union {
+	struct time_sup_frequently_changed__ c;
+	char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(struct time_sup_frequently_changed__))];
+    } f;
+} time_sup erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+ErtsTimeSupData erts_time_sup__ erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+/*
+ * erts_get_approx_time() returns an *approximate* time
+ * in seconds. NOTE that this time may jump backwards!!!
+ */
+erts_approx_time_t
+erts_get_approx_time(void)
 {
-    erts_smp_atomic_init_nob(&approx.time, 0);
+    SysTimeval tv;
+    sys_gettimeofday(&tv);
+
+    return (erts_approx_time_t) tv.tv_sec;
 }
 
-static ERTS_INLINE erts_approx_time_t
-get_approx_time(void)
+static ERTS_INLINE void
+init_time_offset(ErtsMonotonicTime offset)
 {
-    return (erts_approx_time_t) erts_smp_atomic_read_nob(&approx.time);
+    erts_atomic64_init_nob(&time_sup.inf.c.offset, (erts_aint64_t) offset);
 }
 
 static ERTS_INLINE void
-update_approx_time(SysTimeval *tv)
+set_time_offset(ErtsMonotonicTime offset)
 {
-    erts_approx_time_t new_secs = (erts_approx_time_t) tv->tv_sec;
-    erts_approx_time_t old_secs = get_approx_time();
-    if (old_secs != new_secs)
-	erts_smp_atomic_set_nob(&approx.time, new_secs);
+    erts_atomic64_set_relb(&time_sup.inf.c.offset, (erts_aint64_t) offset);
 }
 
-/*
- * erts_get_approx_time() returns an *approximate* time
- * in seconds. NOTE that this time may jump backwards!!!
- */
-erts_approx_time_t
-erts_get_approx_time(void)
+static ERTS_INLINE ErtsMonotonicTime
+get_time_offset(void)
 {
-    return get_approx_time();
+    return (ErtsMonotonicTime) erts_atomic64_read_acqb(&time_sup.inf.c.offset);
 }
 
-#ifdef HAVE_GETHRTIME
 
-int erts_disable_tolerant_timeofday;
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+
+/*
+ * Time correction adjustments made due to
+ * error between Erlang system time and OS
+ * system time:
+ * - Large adjustment ~1%
+ * - Small adjustment ~0.05%
+ */
+#define ERTS_TCORR_ERR_UNIT 2048
+#define ERTS_TCORR_ERR_LARGE_ADJ 20
+#define ERTS_TCORR_ERR_SMALL_ADJ 1
 
-static SysHrTime hr_init_time, hr_last_correction_check, 
-    hr_correction, hr_last_time;
+#define ERTS_INIT_SHORT_INTERVAL_COUNTER 10
+#define ERTS_LONG_TIME_CORRECTION_CHECK ERTS_SEC_TO_MONOTONIC(60)
+#define ERTS_SHORT_TIME_CORRECTION_CHECK ERTS_SEC_TO_MONOTONIC(15)
 
-static void init_tolerant_timeofday(void)
+#define ERTS_TIME_DRIFT_MAX_ADJ_DIFF ERTS_USEC_TO_MONOTONIC(100)
+#define ERTS_TIME_DRIFT_MIN_ADJ_DIFF ERTS_USEC_TO_MONOTONIC(5)
+
+static ERTS_INLINE ErtsMonotonicTime
+calc_corrected_erl_mtime(ErtsMonotonicTime os_mtime,
+			 ErtsMonotonicCorrectionInstance *cip,
+			 ErtsMonotonicTime *os_mdiff_p)
 {
-    /* Should be in sys.c */
-#if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF)
-    if (sysconf(_SC_NPROCESSORS_CONF) > 1) {
-	char b[1024];
-	int maj,min,build;
-	os_flavor(b,1024);
-	os_version(&maj,&min,&build);
-	if (!strcmp(b,"sunos") && maj <= 5 && min <= 7) {
-	    erts_disable_tolerant_timeofday = 1;
-	}
-    }
+    ErtsMonotonicTime erl_mtime, diff = os_mtime - cip->os_mtime;
+    ERTS_TIME_ASSERT(diff >= 0);
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+    diff += (cip->correction.drift*diff)/ERTS_MONOTONIC_TIME_UNIT;
 #endif
-    hr_init_time = sys_gethrtime();
-    hr_last_correction_check = hr_last_time = hr_init_time;
-    hr_correction = 0;
+    erl_mtime = cip->erl_mtime;
+    erl_mtime += diff;
+    erl_mtime += cip->correction.error*(diff/ERTS_TCORR_ERR_UNIT);
+    if (os_mdiff_p)
+	*os_mdiff_p = diff;
+    return erl_mtime;
 }
 
-static void get_tolerant_timeofday(SysTimeval *tv)
+static ErtsMonotonicTime get_corrected_time(void)
 {
-    SysHrTime diff_time, curr;
+    ErtsMonotonicTime os_mtime;
+    ErtsMonotonicCorrectionData cdata;
+    ErtsMonotonicCorrectionInstance *cip;
+
+    erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
+
+    os_mtime = erts_os_monotonic_time();
+
+    cdata = time_sup.inf.c.parmon.cdata;
 
-    if (erts_disable_tolerant_timeofday) {
-	sys_gettimeofday(tv);
-	return;
+    erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
+
+    if (os_mtime >= cdata.curr.os_mtime)
+	cip = &cdata.curr;
+    else {
+	if (os_mtime < cdata.prev.os_mtime)
+	    erl_exit(ERTS_ABORT_EXIT,
+		     "OS monotonic time stepped backwards\n");
+	cip = &cdata.prev;
     }
-    *tv = inittv;
-    diff_time = ((curr = sys_gethrtime()) + hr_correction - hr_init_time) / 1000; 
 
-    if (curr < hr_init_time) {
-	erl_exit(1,"Unexpected behaviour from operating system high "
-		 "resolution timer");
+    return calc_corrected_erl_mtime(os_mtime, cip, NULL);
+}
+
+static void
+check_time_correction(void *unused)
+{
+    ErtsMonotonicCorrectionData cdata;
+    ErtsMonotonicCorrection new_correction;
+    ErtsMonotonicCorrectionInstance *cip;
+    ErtsMonotonicTime mdiff, sdiff, os_mtime, erl_mtime, os_stime, erl_stime, time_offset;
+    Uint timeout;
+    SysTimeval tod;
+    int set_new_correction, begin_short_intervals = 0;
+
+    erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
+
+    ASSERT(time_sup.inf.c.finalized_offset);
+
+    os_mtime = erts_os_monotonic_time();
+    sys_gettimeofday(&tod);
+
+    cdata = time_sup.inf.c.parmon.cdata;
+
+    erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
+
+    if (os_mtime < cdata.curr.os_mtime)
+	erl_exit(ERTS_ABORT_EXIT,
+		 "OS monotonic time stepped backwards\n");
+    cip = &cdata.curr;
+
+    erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, &mdiff);
+    time_offset = get_time_offset();
+    erl_stime = erl_mtime + time_offset;
+
+    os_stime = ERTS_SEC_TO_MONOTONIC(tod.tv_sec);
+    os_stime += ERTS_USEC_TO_MONOTONIC(tod.tv_usec);
+
+    sdiff = erl_stime - os_stime;
+
+    new_correction = cip->correction;
+    
+    if (time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE
+	&& (sdiff < -2*ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF
+	    || 2*ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF < sdiff)) {
+	/* System time diff exeeded limits; change time offset... */
+	time_offset -= sdiff;
+	sdiff = 0;
+	set_time_offset(time_offset);
+	schedule_send_time_offset_changed_notifications(time_offset);
+	begin_short_intervals = 1;
+	if (cdata.curr.correction.error == 0)
+	    set_new_correction = 0;
+	else {
+	    set_new_correction = 1;
+	    new_correction.error = 0;
+	}
+    }
+    else if (cdata.curr.correction.error == 0) {
+	if (sdiff < -ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	    set_new_correction = 1;
+	    if (sdiff < -ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ;
+	    else
+		new_correction.error = ERTS_TCORR_ERR_SMALL_ADJ;
+	}
+	else if (sdiff > ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	    set_new_correction = 1;
+	    if (sdiff > ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
+	    else
+		new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ;
+	}
+	else {
+	    set_new_correction = 0;
+	}
+    }
+    else if (cdata.curr.correction.error > 0) {
+	if (sdiff < 0) {
+	    if (cdata.curr.correction.error == ERTS_TCORR_ERR_LARGE_ADJ
+		|| -ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF <= sdiff)
+		set_new_correction = 0;
+	    else {
+		new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ;
+		set_new_correction = 1;
+	    }
+	}
+	else if (sdiff > ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	    set_new_correction = 1;
+	    if (sdiff > ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
+	    else
+		new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ;
+	}
+	else {
+	    set_new_correction = 1;
+	    new_correction.error = 0;
+	}
+    }
+    else /* if (cdata.curr.correction.error < 0) */ { 
+	if (0 < sdiff) {
+	    if (cdata.curr.correction.error == -ERTS_TCORR_ERR_LARGE_ADJ
+		|| sdiff <= ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		set_new_correction = 0;
+	    else {
+		new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
+		set_new_correction = 1;
+	    }
+	    set_new_correction = 0;
+	}
+	else if (sdiff < -ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	    set_new_correction = 1;
+	    if (sdiff < -ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ;
+	    else
+		new_correction.error = ERTS_TCORR_ERR_SMALL_ADJ;
+	}
+	else {
+	    set_new_correction = 1;
+	    new_correction.error = 0;
+	}
     }
 
-    if ((curr - hr_last_correction_check) / 1000 > 1000000) {
-	/* Check the correction need */
-	SysHrTime tv_diff, diffdiff;
-	SysTimeval tmp;
-	int done = 0;
-
-	sys_gettimeofday(&tmp);
-	tv_diff = ((SysHrTime) tmp.tv_sec) * 1000000 + tmp.tv_usec;
-	tv_diff -= ((SysHrTime) inittv.tv_sec) * 1000000 + inittv.tv_usec;
-	diffdiff = diff_time - tv_diff;
-	if (diffdiff > 10000) {
-	    SysHrTime corr = (curr - hr_last_time) / 100;
-	    if (corr / 1000 >= diffdiff) {
-		++done;
-		hr_correction -= ((SysHrTime)diffdiff) * 1000;
-	    } else {
-		hr_correction -= corr;
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+    {
+	ErtsMonotonicDriftData *ddp = &time_sup.inf.c.parmon.cdata.drift;
+	int ix = ddp->ix;
+	ErtsMonotonicTime mtime_diff, old_os_mtime;
+
+	old_os_mtime = ddp->intervals[ix].time.mon;
+	mtime_diff = os_mtime - old_os_mtime;
+
+	if (mtime_diff >= ERTS_SEC_TO_MONOTONIC(10)) {
+	    ErtsMonotonicTime drift_adj, drift_adj_diff, old_os_stime,
+		stime_diff, mtime_acc, stime_acc, avg_drift_adj;
+
+	    old_os_stime = ddp->intervals[ix].time.sys;
+
+	    mtime_acc = ddp->acc.mon;
+	    stime_acc = ddp->acc.sys;
+
+	    avg_drift_adj = ((stime_acc - mtime_acc)*ERTS_MONOTONIC_TIME_UNIT) / mtime_acc;
+
+	    mtime_diff = os_mtime - old_os_mtime;
+	    stime_diff = os_stime - old_os_stime;
+	    drift_adj = ((stime_diff - mtime_diff)*ERTS_MONOTONIC_TIME_UNIT) / mtime_diff;
+	    
+	    ix++;
+	    if (ix >= ERTS_DRIFT_INTERVALS)
+		ix = 0;
+	    mtime_acc -= ddp->intervals[ix].diff.mon;
+	    mtime_acc += mtime_diff;
+	    stime_acc -= ddp->intervals[ix].diff.sys;
+	    stime_acc += stime_diff;
+
+	    ddp->intervals[ix].diff.mon = mtime_diff;
+	    ddp->intervals[ix].diff.sys = stime_diff;
+	    ddp->intervals[ix].time.mon = os_mtime;
+	    ddp->intervals[ix].time.sys = os_stime;
+
+	    ddp->ix = ix;
+	    ddp->acc.mon = mtime_acc;
+	    ddp->acc.sys = stime_acc;
+
+	    /*
+	     * If calculated drift adjustment is if off by more than 20% from the
+	     * average drift we interpret this as a discontinous leap in system
+	     * time and ignore it. If it actually is a change in drift we will
+	     * later detect this when the average drift change.
+	     */
+	    drift_adj_diff = avg_drift_adj - drift_adj;
+	    if (drift_adj_diff < -ERTS_TIME_DRIFT_MAX_ADJ_DIFF
+		|| ERTS_TIME_DRIFT_MAX_ADJ_DIFF < drift_adj_diff) {
+		ddp->dirty_counter = ERTS_DRIFT_INTERVALS;
+		begin_short_intervals = 1;
 	    }
-	    diff_time = (curr + hr_correction - hr_init_time) / 1000; 
-	} else if (diffdiff < -10000) {
-	    SysHrTime corr = (curr - hr_last_time) / 100;
-	    if (corr / 1000 >= -diffdiff) {
-		++done;
-		hr_correction -= ((SysHrTime)diffdiff) * 1000;
-	    } else {
-		hr_correction += corr;
+	    else {
+		if (ddp->dirty_counter <= 0) {
+		    drift_adj = ((stime_acc - mtime_acc)*ERTS_MONOTONIC_TIME_UNIT) / mtime_acc;
+		}
+		if (ddp->dirty_counter >= 0) {
+		    if (ddp->dirty_counter == 0) {
+			/* Force set new drift correction... */
+			set_new_correction = 1;
+		    }
+		    ddp->dirty_counter--;
+		}
+		drift_adj_diff = drift_adj - new_correction.drift;
+		if (drift_adj_diff) {
+		    if (drift_adj_diff > ERTS_TIME_DRIFT_MAX_ADJ_DIFF)
+			drift_adj_diff = ERTS_TIME_DRIFT_MAX_ADJ_DIFF;
+		    else if (drift_adj_diff < -ERTS_TIME_DRIFT_MAX_ADJ_DIFF)
+			drift_adj_diff = -ERTS_TIME_DRIFT_MAX_ADJ_DIFF;
+		    new_correction.drift += drift_adj_diff;
+
+		    if (drift_adj_diff < -ERTS_TIME_DRIFT_MIN_ADJ_DIFF
+			|| ERTS_TIME_DRIFT_MIN_ADJ_DIFF < drift_adj_diff) {
+			set_new_correction = 1;
+		    }
+		}
 	    }
-	    diff_time = (curr + hr_correction - hr_init_time) / 1000; 
-	} else {
-	    ++done;
 	}
-	if (done) {
-	    hr_last_correction_check = curr;
+    }
+#endif
+
+    begin_short_intervals |= set_new_correction;
+    
+    if (begin_short_intervals) {
+	time_sup.inf.c.parmon.cdata.short_check_interval
+	    = ERTS_INIT_SHORT_INTERVAL_COUNTER;
+    }
+    else if ((os_mtime - time_sup.inf.c.parmon.cdata.last_check
+	      >= ERTS_SHORT_TIME_CORRECTION_CHECK - ERTS_MONOTONIC_TIME_UNIT)
+	     && time_sup.inf.c.parmon.cdata.short_check_interval > 0) {
+	time_sup.inf.c.parmon.cdata.short_check_interval--;
+    }
+    time_sup.inf.c.parmon.cdata.last_check = os_mtime;
+
+    if (new_correction.error == 0)
+	timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_LONG_TIME_CORRECTION_CHECK);
+    else {
+	ErtsMonotonicTime ecorr = new_correction.error;
+	if (sdiff < 0)
+	    sdiff = -1*sdiff;
+	if (ecorr < 0)
+	    ecorr = -1*ecorr;
+	if (sdiff > ecorr*(ERTS_LONG_TIME_CORRECTION_CHECK/ERTS_TCORR_ERR_UNIT))
+	    timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_LONG_TIME_CORRECTION_CHECK);
+	else {
+	    timeout = ERTS_MONOTONIC_TO_MSEC((ERTS_TCORR_ERR_UNIT*sdiff)/ecorr);
+	    if (timeout < 10)
+		timeout = 10;
 	}
     }
-    tv->tv_sec += (int) (diff_time / ((SysHrTime) 1000000));
-    tv->tv_usec += (int) (diff_time % ((SysHrTime) 1000000));
-    if (tv->tv_usec >= 1000000) {
-	tv->tv_usec -= 1000000;
-	tv->tv_sec += 1;
+
+    if (timeout > ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK)
+	&& time_sup.inf.c.parmon.cdata.short_check_interval) {
+	timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK);
     }
-    hr_last_time = curr;
-}
+    
+    if (set_new_correction) {
+	erts_smp_rwmtx_rwlock(&time_sup.inf.c.parmon.rwmtx);
 
-#define correction (hr_correction/1000000)
+	os_mtime = erts_os_monotonic_time();
 
-#else /* !HAVE_GETHRTIME */
-#if !defined(CORRECT_USING_TIMES) 
-#define init_tolerant_timeofday() 
-#define get_tolerant_timeofday(tvp) sys_gettimeofday(tvp)
-#else
+	/* Save previous correction instance */
+	time_sup.inf.c.parmon.cdata.prev = *cip;
 
-typedef Sint64 Milli;
-
-static clock_t init_ct;
-static Sint64 ct_wrap;
-static Milli init_tv_m;
-static Milli correction_supress; 
-static Milli last_ct_diff;
-static Milli last_cc; 
-static clock_t last_ct;
-
-/* sys_times() might need to be wrapped and the values shifted (right)
-   a bit to cope with newer linux (2.5.*) kernels, this has to be taken care 
-   of dynamically to start with, a special version that uses
-   the times() return value as a high resolution timer can be made
-   to fully utilize the faster ticks, like on windows, but for now, we'll
-   settle with this silly workaround */
-#ifdef ERTS_WRAP_SYS_TIMES 
-#define KERNEL_TICKS() (sys_times_wrap() &  \
-			((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) 
-#else
-SysTimes dummy_tms;
+	/*
+	 * Current correction instance begin when
+	 * OS monotonic time has increased one unit.
+	 */
+	os_mtime++;
 
-#define KERNEL_TICKS() (sys_times(&dummy_tms) &  \
-			((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) 
+	/*
+	 * Erlang monotonic time corresponding to
+	 * next OS monotonic time using previous
+	 * correction.
+	 */
+	erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, NULL);
 
-#endif
+	/*
+	 * Save new current correction instance.
+	 */
+	time_sup.inf.c.parmon.cdata.curr.erl_mtime = erl_mtime;
+	time_sup.inf.c.parmon.cdata.curr.os_mtime = os_mtime;
+	time_sup.inf.c.parmon.cdata.curr.correction = new_correction;
 
-static void init_tolerant_timeofday(void)
-{
-    last_ct = init_ct = KERNEL_TICKS();
-    last_cc = 0;
-    init_tv_m = (((Milli) inittv.tv_sec) * 1000) + 
-	(inittv.tv_usec / 1000);
-    ct_wrap = 0;
-    correction_supress = 0;
+	erts_smp_rwmtx_rwunlock(&time_sup.inf.c.parmon.rwmtx);
+    }
+
+    erts_set_timer(&time_sup.inf.c.parmon.timer,
+		   check_time_correction,
+		   NULL,
+		   NULL,
+		   timeout);
 }
 
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
 
-static void get_tolerant_timeofday(SysTimeval *tvp)
+static void
+init_check_time_correction(void *unused)
 {
-    clock_t current_ct;
-    SysTimeval current_tv;
-    Milli ct_diff;
-    Milli tv_diff;
-    Milli current_correction;
-    Milli act_correction;	/* long shown to be too small */
-    Milli max_adjust;
-
-    if (erts_disable_tolerant_timeofday) {
-	sys_gettimeofday(tvp);
-	return;
+    ErtsMonotonicDriftData *ddp;
+    ErtsMonotonicTime old_mtime, old_stime, mtime, stime, mtime_diff, stime_diff;
+    int ix;
+    SysTimeval tod;
+
+    ddp = &time_sup.inf.c.parmon.cdata.drift;
+    ix = ddp->ix;
+    old_mtime = ddp->intervals[0].time.mon;
+    old_stime = ddp->intervals[0].time.sys;
+
+    mtime = erts_os_monotonic_time();
+    sys_gettimeofday(&tod);
+
+    stime = ERTS_SEC_TO_MONOTONIC(tod.tv_sec);
+    stime += ERTS_USEC_TO_MONOTONIC(tod.tv_usec);
+
+    mtime_diff = mtime - old_mtime;
+    stime_diff = stime - old_stime;
+    if (100*stime_diff  < 80*mtime_diff || 120*mtime_diff < 100*stime_diff ) {
+	/* Had a system time leap... pretend no drift... */
+	stime_diff = mtime_diff;
+    }
+    
+    /*
+     * We use old time values in order to trigger
+     * a drift adjustment, and repeat this interval
+     * in all slots...
+     */
+    for (ix = 0; ix < ERTS_DRIFT_INTERVALS; ix++) {
+	ddp->intervals[ix].diff.mon = mtime_diff;
+	ddp->intervals[ix].diff.sys = stime_diff;
+	ddp->intervals[ix].time.mon = old_mtime;
+	ddp->intervals[ix].time.sys = old_stime;
     }
 
-#ifdef ERTS_WRAP_SYS_TIMES 
-#define TICK_MS (1000 / SYS_CLK_TCK_WRAP)
+    ddp->acc.sys = stime_diff*ERTS_DRIFT_INTERVALS;
+    ddp->acc.mon = mtime_diff*ERTS_DRIFT_INTERVALS;
+    ddp->ix = 0;
+    ddp->dirty_counter = ERTS_DRIFT_INTERVALS;
+
+    check_time_correction(NULL);
+}
+
+#endif
+
+static ErtsMonotonicTime
+finalize_corrected_time_offset(SysTimeval *todp)
+{
+    ErtsMonotonicTime os_mtime;
+    ErtsMonotonicCorrectionData cdata;
+    ErtsMonotonicCorrectionInstance *cip;
+
+    erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
+
+    os_mtime = erts_os_monotonic_time();
+    sys_gettimeofday(todp);
+
+    cdata = time_sup.inf.c.parmon.cdata;
+
+    erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
+
+    if (os_mtime < cdata.curr.os_mtime)
+	erl_exit(ERTS_ABORT_EXIT,
+		 "OS monotonic time stepped backwards\n");
+    cip = &cdata.curr;
+
+    return calc_corrected_erl_mtime(os_mtime, cip, NULL);
+}
+
+static void
+late_init_time_correction(void)
+{
+    if (time_sup.inf.c.finalized_offset) {
+	erts_init_timer(&time_sup.inf.c.parmon.timer);
+	erts_set_timer(&time_sup.inf.c.parmon.timer,
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+		       init_check_time_correction,
 #else
-#define TICK_MS (1000 / SYS_CLK_TCK)
+		       check_time_correction,
 #endif
-    current_ct = KERNEL_TICKS();
-    sys_gettimeofday(&current_tv);
-
-    /* I dont know if uptime can move some units backwards
-       on some systems, but I allow for small backward 
-       jumps to avoid such problems if they exist...*/
-    if (last_ct > 100 && current_ct < (last_ct - 100)) {
-	ct_wrap += ((Sint64) 1) << ((sizeof(clock_t) * 8) - 1);
+		       NULL,
+		       NULL,
+		       ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK));
     }
-    last_ct = current_ct;
-    ct_diff = ((ct_wrap + current_ct) - init_ct) * TICK_MS;
+}
 
-    /*
-     * We will adjust the time in milliseconds and we allow for 1% 
-     * adjustments, but if this function is called more often then every 100 
-     * millisecond (which is obviously possible), we will never adjust, so 
-     * we accumulate small times by setting last_ct_diff iff max_adjust > 0
-     */
-    if ((max_adjust = (ct_diff - last_ct_diff)/100) > 0)
-	last_ct_diff = ct_diff;
+#endif /* ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT */
 
-    tv_diff = ((((Milli) current_tv.tv_sec) * 1000) + 
-	       (current_tv.tv_usec / 1000)) - init_tv_m;
+static ErtsMonotonicTime get_not_corrected_time(void)
+{
+    SysTimeval tmp_tv;
+    ErtsMonotonicTime stime, mtime;
 
-    current_correction = ((ct_diff - tv_diff) / TICK_MS) * TICK_MS; /* trunc */
+    erts_smp_mtx_lock(&erts_get_time_mtx);
 
-    /* 
-     * We allow the current_correction value to wobble a little, as it
-     * suffers from the low resolution of the kernel ticks. 
-     * if it hasn't changed more than one tick in either direction, 
-     * we will keep the old value.
-     */
-    if ((last_cc > current_correction + TICK_MS) ||
-	(last_cc < current_correction - TICK_MS)) {
-	last_cc = current_correction;
-    } else {
-	current_correction = last_cc;
-    }
-    
-    /*
-     * As time goes, we try to get the actual correction to 0, 
-     * that is, make erlangs time correspond to the systems dito.
-     * The act correction is what we seem to need (current_correction)
-     * minus the correction suppression. The correction supression
-     * will change slowly (max 1% of elapsed time) but in millisecond steps.
-     */
-    act_correction = current_correction - correction_supress;
-    if (max_adjust > 0) {
-	/*
-	 * Here we slowly adjust erlangs time to correspond with the 
-	 * system time by changing the correction_supress variable.
-	 * It can change max_adjust milliseconds which is 1% of elapsed time
-	 */
-	if (act_correction > 0) {
-	    if (current_correction - correction_supress > max_adjust) {
-		correction_supress += max_adjust;
-	    } else {
-		correction_supress = current_correction;
-	    }
-	    act_correction = current_correction - correction_supress;
-	} else if (act_correction < 0) {
-	    if (correction_supress - current_correction > max_adjust) {
-		correction_supress -= max_adjust;
-	    } else {
-		correction_supress = current_correction;
+    sys_gettimeofday(&tmp_tv);
+
+    stime = ERTS_SEC_TO_MONOTONIC(tmp_tv.tv_sec);
+    stime += ERTS_USEC_TO_MONOTONIC(tmp_tv.tv_usec);
+
+    mtime = stime - time_sup.inf.c.not_corrected_moffset;
+
+    if (mtime >= time_sup.f.c.last_not_corrected_time)
+	time_sup.f.c.last_not_corrected_time = mtime;
+    else {
+	mtime = time_sup.f.c.last_not_corrected_time;
+
+	if (time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE) {
+	    ErtsMonotonicTime new_offset = stime - mtime;
+	    new_offset = ERTS_MONOTONIC_TO_USEC(new_offset);
+	    new_offset = ERTS_USEC_TO_MONOTONIC(new_offset);
+	    if (time_sup.inf.c.not_corrected_moffset != new_offset) {
+		time_sup.inf.c.not_corrected_moffset = new_offset;
+		set_time_offset(new_offset);
+		schedule_send_time_offset_changed_notifications(new_offset);
 	    }
-	    act_correction = current_correction - correction_supress;
 	}
+
     }
-    /*
-     * The actual correction will correct the timeval so that system 
-     * time warps gets smothed down.
-     */
-    current_tv.tv_sec += act_correction / 1000;
-    current_tv.tv_usec += (act_correction % 1000) * 1000;
-
-    if (current_tv.tv_usec >= 1000000) {
-	++current_tv.tv_sec ;
-	current_tv.tv_usec -= 1000000;
-    } else if (current_tv.tv_usec < 0) {
-	--current_tv.tv_sec;
-	current_tv.tv_usec += 1000000;
-    }
-    *tvp = current_tv;
-#undef TICK_MS
+
+    ASSERT(stime == mtime + time_sup.inf.c.not_corrected_moffset);
+
+    erts_smp_mtx_unlock(&erts_get_time_mtx);
+
+    return mtime;
 }
 
-#endif /* CORRECT_USING_TIMES */
-#endif /* !HAVE_GETHRTIME */
+int erts_check_time_adj_support(int time_correction,
+				ErtsTimeWarpMode time_warp_mode)
+{
+    if (!time_correction)
+	return 1;
 
-/*
-** Why this? Well, most platforms have a constant clock resolution of 1,
-** we dont want the deliver_time/time_remaining routines to waste 
-** time dividing and multiplying by/with a variable that's always one.
-** so the return value of sys_init_time is ignored on those platforms.
-*/
- 
-#ifndef SYS_CLOCK_RESOLUTION
-static int clock_resolution;
-#define CLOCK_RESOLUTION clock_resolution
+    /* User wants time correction */
+
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    return !time_sup.r.o.os_monotonic_disable;
 #else
-#define CLOCK_RESOLUTION SYS_CLOCK_RESOLUTION
+    return 0;
 #endif
+}
 
-/*
-** The clock resolution should really be the resolution of the 
-** time function in use, which on most platforms 
-** is 1. On VxWorks the resolution should be
-** the number of ticks per second (or 1, which would work nicely to).
-**
-** Setting lower resolutions is mostly interesting when timers are used
-** instead of something like select.
-*/
-
-static SysTimeval last_delivered; 
-
-static void init_erts_deliver_time(const SysTimeval *inittv)
+int
+erts_has_time_correction(void)
 {
-    /* We set the initial values for deliver_time here */
-    last_delivered = *inittv;
-    last_delivered.tv_usec = 1000 * (last_delivered.tv_usec / 1000); 
-                                                   /* ms resolution */
+    return time_sup.r.o.correction;
 }
 
-static void do_erts_deliver_time(const SysTimeval *current)
+void
+erts_early_init_time_sup(void)
 {
-    SysTimeval cur_time;
-    erts_time_t elapsed;
-    
-    /* calculate and deliver appropriate number of ticks */
-    cur_time = *current;
-    cur_time.tv_usec = 1000 * (cur_time.tv_usec / 1000); /* ms resolution */
-    elapsed = (1000 * (cur_time.tv_sec - last_delivered.tv_sec) +
-	       (cur_time.tv_usec - last_delivered.tv_usec) / 1000) / 
-	CLOCK_RESOLUTION;
+    ErtsSysInitTimeResult sys_init_time_res
+	= ERTS_SYS_INIT_TIME_RESULT_INITER;
 
-    /* Sometimes the time jump backwards,
-       resulting in a negative elapsed time. We compensate for
-       this by simply pretend as if the time stood still. :) */
+    sys_init_time(&sys_init_time_res);
 
-    if (elapsed > 0) {
+    erts_time_sup__.r.o.monotonic_time_unit
+	= sys_init_time_res.os_monotonic_time_unit;
 
-	ASSERT(elapsed < ((erts_time_t) ERTS_SHORT_TIME_T_MAX));
+#ifndef SYS_CLOCK_RESOLUTION
+    erts_time_sup__.r.o.clktck_resolution
+	= sys_init_time_res.sys_clock_resolution;
+    erts_time_sup__.r.o.clktck_resolution *= 1000;
+#endif
 
-	erts_do_time_add((erts_short_time_t) elapsed);
-	last_delivered = cur_time;
-    }
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    time_sup.r.o.os_monotonic_disable
+	= !sys_init_time_res.have_os_monotonic;
+    time_sup.r.o.os_monotonic_func
+	= sys_init_time_res.os_monotonic_info.func;
+    time_sup.r.o.os_monotonic_clock_id
+	= sys_init_time_res.os_monotonic_info.clock_id;
+    time_sup.r.o.os_monotonic_locked
+	= sys_init_time_res.os_monotonic_info.locked_use;
+    time_sup.r.o.os_monotonic_resolution
+	= sys_init_time_res.os_monotonic_info.resolution;
+#endif
 }
 
 int 
-erts_init_time_sup(void)
+erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
 {
+#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+    ErtsMonotonicTime abs_start;
+#endif
+
+    ASSERT(ERTS_MONOTONIC_TIME_MIN < ERTS_MONOTONIC_TIME_MAX);
+
     erts_smp_mtx_init(&erts_timeofday_mtx, "timeofday");
+    erts_smp_mtx_init(&erts_get_time_mtx, "get_time");
 
-    init_approx_time();
+    time_sup.r.o.correction = time_correction;
+    time_sup.r.o.warp_mode = time_warp_mode;
+ 
+    if (time_warp_mode == ERTS_SINGLE_TIME_WARP_MODE)
+	time_sup.inf.c.finalized_offset = 0;
+    else
+	time_sup.inf.c.finalized_offset = ~0;
+
+#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+
+#ifdef ARCH_32
+    time_sup.r.o.start = ((((ErtsMonotonicTime) 1) << 32)-1);
+    time_sup.r.o.start /= ERTS_MONOTONIC_TIME_UNIT;
+    time_sup.r.o.start *= ERTS_MONOTONIC_TIME_UNIT;
+    time_sup.r.o.start += ERTS_MONOTONIC_TIME_UNIT;
+    abs_start = time_sup.r.o.start;
+#else /* ARCH_64 */
+    if (ERTS_MONOTONIC_TIME_UNIT <= 1000*1000)
+	abs_start = time_sup.r.o.start = 0;
+    else {
+	time_sup.r.o.start = ((ErtsMonotonicTime) MIN_SMALL);
+	time_sup.r.o.start /= ERTS_MONOTONIC_TIME_UNIT;
+	time_sup.r.o.start *= ERTS_MONOTONIC_TIME_UNIT;
+	abs_start = -1*time_sup.r.o.start;
+    }
+#endif
 
-    last_emu_time.tv_sec = 0;
-    last_emu_time.tv_usec = 0;
+    time_sup.r.o.start_offset.native = time_sup.r.o.start;
+    time_sup.r.o.start_offset.nsec = (ErtsMonotonicTime)
+	erts_time_unit_conversion((Uint64) abs_start,
+				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
+				  (Uint32) 1000*1000*1000);
+    time_sup.r.o.start_offset.usec = (ErtsMonotonicTime)
+	erts_time_unit_conversion((Uint64) abs_start,
+				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
+				  (Uint32) 1000*1000);
+    time_sup.r.o.start_offset.msec = (ErtsMonotonicTime)
+	erts_time_unit_conversion((Uint64) abs_start,
+				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
+				  (Uint32) 1000);
+    time_sup.r.o.start_offset.sec = (ErtsMonotonicTime)
+	erts_time_unit_conversion((Uint64) abs_start,
+				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
+				  (Uint32) 1);
+    if (time_sup.r.o.start < 0) {
+	time_sup.r.o.start_offset.nsec *= -1;
+	time_sup.r.o.start_offset.usec *= -1;
+	time_sup.r.o.start_offset.msec *= -1;
+	time_sup.r.o.start_offset.sec *= -1;
+    }
 
-#ifndef SYS_CLOCK_RESOLUTION
-    clock_resolution = sys_init_time();
-#else
-    (void) sys_init_time();
 #endif
-    sys_gettimeofday(&inittv);
+
+    if (ERTS_MONOTONIC_TIME_UNIT < ERTS_CLKTCK_RESOLUTION)
+	ERTS_INTERNAL_ERROR("Too small monotonic time time unit");
+
+#ifndef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    time_sup.r.o.correction = 0;
+#else
+    if (time_sup.r.o.os_monotonic_disable)
+	time_sup.r.o.correction = 0;
+
+    if (time_sup.r.o.correction) {
+	ErtsMonotonicCorrectionData *cdatap;
+	erts_smp_rwmtx_opt_t rwmtx_opts = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
+	ErtsMonotonicTime offset;
+	time_sup.inf.c.minit = erts_os_monotonic_time();
+	sys_gettimeofday(&time_sup.inf.c.inittv);
+	time_sup.r.o.moffset = -1*time_sup.inf.c.minit;
+	offset = ERTS_SEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_sec);
+	offset += ERTS_USEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_usec);
+	init_time_offset(offset);
+
+	rwmtx_opts.type = ERTS_SMP_RWMTX_TYPE_EXTREMELY_FREQUENT_READ;
+	rwmtx_opts.lived = ERTS_SMP_RWMTX_LONG_LIVED;
+
+	erts_smp_rwmtx_init_opt(&time_sup.inf.c.parmon.rwmtx,
+				&rwmtx_opts, "get_corrected_time");
+
+	cdatap = &time_sup.inf.c.parmon.cdata;
     
-#ifdef HAVE_GETHRTIME
-    sys_init_hrtime();
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+	cdatap->drift.intervals[0].time.sys
+	    = ERTS_SEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_sec);
+	cdatap->drift.intervals[0].time.sys
+	    += ERTS_USEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_usec);
+	cdatap->drift.intervals[0].time.mon = time_sup.inf.c.minit;
+	cdatap->curr.correction.drift = 0;
+#endif
+	cdatap->curr.correction.error = 0;
+	cdatap->curr.erl_mtime = 0;
+	cdatap->curr.os_mtime = time_sup.inf.c.minit;
+	cdatap->last_check = time_sup.inf.c.minit;
+	cdatap->short_check_interval = ERTS_INIT_SHORT_INTERVAL_COUNTER;
+	cdatap->prev = cdatap->curr;
+
+	time_sup.r.o.get_time = get_corrected_time;
+    }
+    else
 #endif
-    init_tolerant_timeofday();
+    {
+	ErtsMonotonicTime stime, offset;
+	time_sup.r.o.get_time = get_not_corrected_time;
+	stime = ERTS_SEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_sec);
+	stime += ERTS_USEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_usec);
+	offset = stime;
+	time_sup.inf.c.not_corrected_moffset = offset;
+	init_time_offset(offset);
+	time_sup.f.c.last_not_corrected_time = 0;
+    }
+
+    prev_wall_clock_elapsed = 0;
 
-    init_erts_deliver_time(&inittv);
-    gtv = inittv;
-    then.tv_sec = then.tv_usec = 0;
+    previous_now = ERTS_MONOTONIC_TO_USEC(get_time_offset());
 
-    erts_deliver_time();
+#ifdef DEBUG
+    time_sup_initialized = 1;
+#endif
 
-    return CLOCK_RESOLUTION;
+    return ERTS_CLKTCK_RESOLUTION/1000;
 }    
+
+void
+erts_late_init_time_sup(void)
+{
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    /* Timer wheel must be initialized */
+    if (time_sup.r.o.get_time == get_corrected_time)
+	late_init_time_correction();
+#endif
+}
+
+ErtsTimeWarpMode erts_time_warp_mode(void)
+{
+    return time_sup.r.o.warp_mode;
+}
+
+ErtsTimeOffsetState erts_time_offset_state(void)
+{
+    switch (time_sup.r.o.warp_mode) {
+    case ERTS_NO_TIME_WARP_MODE:
+	return ERTS_TIME_OFFSET_FINAL;
+    case ERTS_SINGLE_TIME_WARP_MODE:
+	if (time_sup.inf.c.finalized_offset)
+	    return ERTS_TIME_OFFSET_FINAL;
+	return ERTS_TIME_OFFSET_PRELIMINARY;
+    case ERTS_MULTI_TIME_WARP_MODE:
+	return ERTS_TIME_OFFSET_VOLATILE;
+    default:
+	ERTS_INTERNAL_ERROR("Invalid time warp mode");
+	return ERTS_TIME_OFFSET_VOLATILE;
+    }
+}
+
+/*
+ * erts_finalize_time_offset() will only change time offset
+ * the first time it is called when the emulator has been
+ * started in "single time warp" mode. Returns previous
+ * state:
+ * * ERTS_TIME_OFFSET_PRELIMINARY - Finalization performed
+ * * ERTS_TIME_OFFSET_FINAL - Already finialized; nothing changed
+ * * ERTS_TIME_OFFSET_VOLATILE - Not supported, either in
+ * * no correction mode (or multi time warp mode; not yet implemented).
+ */
+
+ErtsTimeOffsetState
+erts_finalize_time_offset(void)
+{
+    switch (time_sup.r.o.warp_mode) {
+    case ERTS_NO_TIME_WARP_MODE:
+	return ERTS_TIME_OFFSET_FINAL;
+    case ERTS_MULTI_TIME_WARP_MODE:
+	return ERTS_TIME_OFFSET_VOLATILE;
+    case ERTS_SINGLE_TIME_WARP_MODE: {
+	ErtsTimeOffsetState res = ERTS_TIME_OFFSET_FINAL;
+
+	erts_smp_mtx_lock(&erts_get_time_mtx);
+
+	if (!time_sup.inf.c.finalized_offset) {
+	    ErtsMonotonicTime mtime, new_offset;
+	    SysTimeval tv;
+
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+	    if (!time_sup.r.o.correction)
+#endif
+	    {
+		ErtsMonotonicTime stime;
+		sys_gettimeofday(&tv);
+
+		stime = ERTS_SEC_TO_MONOTONIC(tv.tv_sec);
+		stime += ERTS_USEC_TO_MONOTONIC(tv.tv_usec);
+
+		mtime = stime - time_sup.inf.c.not_corrected_moffset;
+
+		if (mtime >= time_sup.f.c.last_not_corrected_time) {
+		    time_sup.f.c.last_not_corrected_time = mtime;
+		    new_offset = time_sup.inf.c.not_corrected_moffset;
+		}
+		else {
+		    mtime = time_sup.f.c.last_not_corrected_time;
+
+		    ASSERT(time_sup.inf.c.not_corrected_moffset != stime - mtime);
+		    new_offset = stime - mtime;
+		    time_sup.inf.c.not_corrected_moffset = new_offset;
+		}
+
+	    }
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+	    else {
+		mtime = finalize_corrected_time_offset(&tv);
+		new_offset = ERTS_SEC_TO_MONOTONIC(tv.tv_sec);
+		new_offset += ERTS_USEC_TO_MONOTONIC(tv.tv_usec);
+		new_offset -= mtime;
+
+	    }
+#endif
+	    new_offset = ERTS_MONOTONIC_TO_USEC(new_offset);
+	    new_offset = ERTS_USEC_TO_MONOTONIC(new_offset);
+
+	    set_time_offset(new_offset);
+	    schedule_send_time_offset_changed_notifications(new_offset);
+
+	    time_sup.inf.c.finalized_offset = ~0;
+	    res = ERTS_TIME_OFFSET_PRELIMINARY;
+	}
+
+	erts_smp_mtx_unlock(&erts_get_time_mtx);
+
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+	if (res == ERTS_TIME_OFFSET_PRELIMINARY
+	    && time_sup.r.o.get_time == get_corrected_time) {
+	    late_init_time_correction();
+	}
+#endif
+
+	return res;
+    }
+    default:
+	ERTS_INTERNAL_ERROR("Invalid time warp mode");
+	return ERTS_TIME_OFFSET_VOLATILE;
+    }
+}
+
 /* info functions */
 
 void 
@@ -498,23 +1091,16 @@ elapsed_time_both(UWord *ms_user, UWord *ms_sys,
 void 
 wall_clock_elapsed_time_both(UWord *ms_total, UWord *ms_diff)
 {
-    UWord prev_total;
-    SysTimeval tv;
+    ErtsMonotonicTime now, elapsed;
 
     erts_smp_mtx_lock(&erts_timeofday_mtx);
 
-    get_tolerant_timeofday(&tv);
-
-    *ms_total = 1000 * (tv.tv_sec - inittv.tv_sec) +
-	(tv.tv_usec - inittv.tv_usec) / 1000;
+    now = time_sup.r.o.get_time();
 
-    prev_total = 1000 * (gtv.tv_sec - inittv.tv_sec) +
-	(gtv.tv_usec - inittv.tv_usec) / 1000;
-    *ms_diff = *ms_total - prev_total;
-    gtv = tv;
-
-    /* must sync the machine's idea of time here */
-    do_erts_deliver_time(&tv);
+    elapsed = ERTS_MONOTONIC_TO_MSEC(now);
+    *ms_total = (UWord) elapsed;
+    *ms_diff = (UWord) (elapsed - prev_wall_clock_elapsed);
+    prev_wall_clock_elapsed = elapsed;
 
     erts_smp_mtx_unlock(&erts_timeofday_mtx);
 }
@@ -890,38 +1476,41 @@ univ_to_local(Sint *year, Sint *month, Sint *day,
     return 0;
 }
 
-
 /* get a timestamp */
 void
 get_now(Uint* megasec, Uint* sec, Uint* microsec)
 {
-    SysTimeval now;
+    ErtsMonotonicTime now_megasec, now_sec, now, mtime, time_offset;
     
+    mtime = time_sup.r.o.get_time();
+    time_offset = get_time_offset();
+    now = ERTS_MONOTONIC_TO_USEC(mtime + time_offset);
+
     erts_smp_mtx_lock(&erts_timeofday_mtx);
-    
-    get_tolerant_timeofday(&now);
-    do_erts_deliver_time(&now);
-
-    /* Make sure time is later than last */
-    if (then.tv_sec > now.tv_sec ||
-	(then.tv_sec == now.tv_sec && then.tv_usec >= now.tv_usec)) {
-	now = then;
-	now.tv_usec++;
-    }
-    /* Check for carry from above + general reasonability */
-    if (now.tv_usec >= 1000000) {
-	now.tv_usec = 0;
-	now.tv_sec++;
-    }
-    then = now;
+
+    /* Make sure now time is later than last time */
+    if (now <= previous_now)
+	now = previous_now + 1;
+
+    previous_now = now;
     
     erts_smp_mtx_unlock(&erts_timeofday_mtx);
-    
-    *megasec = (Uint) (now.tv_sec / 1000000);
-    *sec = (Uint) (now.tv_sec % 1000000);
-    *microsec = (Uint) (now.tv_usec);
 
-    update_approx_time(&now);
+    now_megasec = now / ERTS_MONOTONIC_TIME_TERA;
+    now_sec = now / ERTS_MONOTONIC_TIME_MEGA;
+    *megasec = (Uint) now_megasec;
+    *sec = (Uint) (now_sec - now_megasec*ERTS_MONOTONIC_TIME_MEGA);
+    *microsec = (Uint) (now - now_sec*ERTS_MONOTONIC_TIME_MEGA);
+
+    ASSERT(((ErtsMonotonicTime) *megasec)*ERTS_MONOTONIC_TIME_TERA
+	   + ((ErtsMonotonicTime) *sec)*ERTS_MONOTONIC_TIME_MEGA
+	   + ((ErtsMonotonicTime) *microsec) == now);
+}
+
+ErtsMonotonicTime
+erts_get_monotonic_time(void)
+{
+    return time_sup.r.o.get_time();
 }
 
 void
@@ -934,102 +1523,466 @@ get_sys_now(Uint* megasec, Uint* sec, Uint* microsec)
     *megasec = (Uint) (now.tv_sec / 1000000);
     *sec = (Uint) (now.tv_sec % 1000000);
     *microsec = (Uint) (now.tv_usec);
-
-    update_approx_time(&now);
 }
 
+#ifdef HAVE_ERTS_NOW_CPU
+void erts_get_now_cpu(Uint* megasec, Uint* sec, Uint* microsec) {
+  SysCpuTime t;
+  SysTimespec tp;
 
-/* deliver elapsed *ticks* to the machine - takes a pointer
-   to a struct timeval representing current time (to save
-   a gettimeofday() where possible) or NULL */
+  sys_get_proc_cputime(t, tp);
+  *microsec = (Uint)(tp.tv_nsec / 1000);
+  t = (tp.tv_sec / 1000000);
+  *megasec = (Uint)(t % 1000000);
+  *sec = (Uint)(tp.tv_sec % 1000000);
+}
+#endif
 
-void erts_deliver_time(void) {
-    SysTimeval now;
-    
-    erts_smp_mtx_lock(&erts_timeofday_mtx);
-    
-    get_tolerant_timeofday(&now);
-    do_erts_deliver_time(&now);
-    
-    erts_smp_mtx_unlock(&erts_timeofday_mtx);
+#include "big.h"
 
-    update_approx_time(&now);
+void
+erts_monitor_time_offset(Eterm id, Eterm ref)
+{
+    erts_smp_mtx_lock(&erts_get_time_mtx);
+    erts_add_monitor(&time_offset_monitors, MON_TIME_OFFSET, ref, id, NIL);
+    no_time_offset_monitors++;
+    erts_smp_mtx_unlock(&erts_get_time_mtx);
 }
 
-/* get *real* time (not ticks) remaining until next timeout - if there
-   isn't one, give a "long" time, that is guaranteed
-   to not cause overflow when we report elapsed time later on */
+int
+erts_demonitor_time_offset(Eterm ref)
+{
+    int res;
+    ErtsMonitor *mon;
+    ASSERT(is_internal_ref(ref));
+    erts_smp_mtx_lock(&erts_get_time_mtx);
+    mon = erts_remove_monitor(&time_offset_monitors, ref);
+    if (!mon)
+	res = 0;
+    else {
+	ASSERT(no_time_offset_monitors > 0);
+	no_time_offset_monitors--;
+	res = 1;
+    }
+    erts_smp_mtx_unlock(&erts_get_time_mtx);
+    if (res)
+	erts_destroy_monitor(mon);
+    return res;
+}
 
-void erts_time_remaining(SysTimeval *rem_time)
+typedef struct {
+    Eterm pid;
+    Eterm ref;
+    Eterm heap[REF_THING_SIZE];
+} ErtsTimeOffsetMonitorInfo;
+
+typedef struct {
+    Uint ix;
+    ErtsTimeOffsetMonitorInfo *to_mon_info;
+} ErtsTimeOffsetMonitorContext;
+
+static void
+save_time_offset_monitor(ErtsMonitor *mon, void *vcntxt)
 {
-    erts_time_t ticks;
-    SysTimeval cur_time;
-    erts_time_t elapsed;
-
-    /* erts_next_time() returns no of ticks to next timeout or -1 if none */
-
-    ticks = (erts_time_t) erts_next_time();
-    if (ticks == (erts_time_t) -1) {
-	/* timer queue empty */
-	/* this will cause at most 100000000 ticks */
-	rem_time->tv_sec = 100000;
-	rem_time->tv_usec = 0;
-    } else {
-	/* next timeout after ticks ticks */
-	ticks *= CLOCK_RESOLUTION;
-	
-	erts_smp_mtx_lock(&erts_timeofday_mtx);
-	
-	get_tolerant_timeofday(&cur_time);
-	cur_time.tv_usec = 1000 * 
-	    (cur_time.tv_usec / 1000);/* ms resolution*/
-	elapsed = 1000 * (cur_time.tv_sec - last_delivered.tv_sec) +
-	    (cur_time.tv_usec - last_delivered.tv_usec) / 1000;
-	
-	erts_smp_mtx_unlock(&erts_timeofday_mtx);
+    ErtsTimeOffsetMonitorContext *cntxt;
+    Eterm *from_hp, *to_hp;
+    Uint mix;
+    int hix;
+
+    cntxt = (ErtsTimeOffsetMonitorContext *) vcntxt;
+    mix = (cntxt->ix)++;
+    cntxt->to_mon_info[mix].pid = mon->pid;
+    to_hp = &cntxt->to_mon_info[mix].heap[0];
+
+    ASSERT(is_internal_ref(mon->ref));
+    from_hp = internal_ref_val(mon->ref);
+    ASSERT(thing_arityval(*from_hp) + 1 == REF_THING_SIZE);
+
+    for (hix = 0; hix < REF_THING_SIZE; hix++)
+	to_hp[hix] = from_hp[hix];
+
+    cntxt->to_mon_info[mix].ref
+	= make_internal_ref(&cntxt->to_mon_info[mix].heap[0]);
+
+}
+
+static void
+send_time_offset_changed_notifications(void *new_offsetp)
+{
+    ErtsMonotonicTime new_offset;
+    ErtsTimeOffsetMonitorInfo *to_mon_info;
+    Uint no_monitors;
+    char *tmp = NULL;
+
+#ifdef ARCH_64
+    new_offset = (ErtsMonotonicTime) new_offsetp;
+#else
+    new_offset = *((ErtsMonotonicTime *) new_offsetp);
+    erts_free(ERTS_ALC_T_NEW_TIME_OFFSET, new_offsetp);
+#endif
+    new_offset -= ERTS_MONOTONIC_OFFSET_NATIVE;
+
+    erts_smp_mtx_lock(&erts_get_time_mtx);
+
+    no_monitors = no_time_offset_monitors;
+    if (no_monitors) {
+	ErtsTimeOffsetMonitorContext cntxt;
+	Uint alloc_sz;
 	
-	if (ticks <= elapsed) { /* Ooops, better hurry */
-	    rem_time->tv_sec = rem_time->tv_usec = 0;
-	    return;
+	/* Monitor info array size */
+	alloc_sz = no_monitors*sizeof(ErtsTimeOffsetMonitorInfo);
+	/* + template max size */
+	alloc_sz += 6*sizeof(Eterm); /* 5-tuple */
+	alloc_sz += ERTS_MAX_SINT64_HEAP_SIZE*sizeof(Eterm); /* max offset size */
+	tmp = erts_alloc(ERTS_ALC_T_TMP, alloc_sz);
+
+	to_mon_info = (ErtsTimeOffsetMonitorInfo *) tmp;
+	cntxt.ix = 0;
+	cntxt.to_mon_info = to_mon_info;
+
+	erts_doforall_monitors(time_offset_monitors,
+			       save_time_offset_monitor,
+			       &cntxt);
+
+	ASSERT(cntxt.ix == no_monitors);
+    }
+
+    erts_smp_mtx_unlock(&erts_get_time_mtx);
+
+    if (no_monitors) {
+	Eterm *hp, *patch_refp, new_offset_term, message_template;
+	Uint mix, hsz;
+
+	/* Make message template */
+
+	hp = (Eterm *) (tmp + no_monitors*sizeof(ErtsTimeOffsetMonitorInfo));
+
+	hsz = 6; /* 5-tuple */
+	hsz += REF_THING_SIZE;
+	hsz += ERTS_SINT64_HEAP_SIZE(new_offset);
+
+	if (IS_SSMALL(new_offset))
+	    new_offset_term = make_small(new_offset);
+	else
+	    new_offset_term = erts_sint64_to_big(new_offset, &hp);
+	message_template = TUPLE5(hp,
+				  am_CHANGE,
+				  THE_NON_VALUE, /* Patch point for ref */
+				  am_time_offset,
+				  am_clock_service,
+				  new_offset_term);
+	patch_refp = &hp[2];
+
+	ASSERT(*patch_refp == THE_NON_VALUE);
+
+	for (mix = 0; mix < no_monitors; mix++) {
+	    Process *rp = erts_proc_lookup(to_mon_info[mix].pid);
+	    if (rp) {
+		Eterm ref = to_mon_info[mix].ref;
+		ErtsProcLocks rp_locks = ERTS_PROC_LOCK_LINK;
+		erts_smp_proc_lock(rp, ERTS_PROC_LOCK_LINK);
+		if (erts_lookup_monitor(ERTS_P_MONITORS(rp), ref)) {
+		    ErlHeapFragment *bp;
+		    ErlOffHeap *ohp;
+		    Eterm message;
+
+		    hp = erts_alloc_message_heap(hsz, &bp, &ohp, rp, &rp_locks);
+		    *patch_refp = ref;
+		    ASSERT(hsz == size_object(message_template));
+		    message = copy_struct(message_template, hsz, &hp, ohp);
+		    erts_queue_message(rp, &rp_locks, bp, message, NIL
+#ifdef USE_VM_PROBES
+				       , NIL
+#endif
+			);
+		}
+		erts_smp_proc_unlock(rp, rp_locks);
+	    }
 	}
-	rem_time->tv_sec = (ticks - elapsed) / 1000;
-	rem_time->tv_usec = 1000 * ((ticks - elapsed) % 1000);
+
+	erts_free(ERTS_ALC_T_TMP, tmp);
     }
 }
 
-void erts_get_timeval(SysTimeval *tv)
+static void
+schedule_send_time_offset_changed_notifications(ErtsMonotonicTime new_offset)
 {
-    erts_smp_mtx_lock(&erts_timeofday_mtx);
-    get_tolerant_timeofday(tv);
-    erts_smp_mtx_unlock(&erts_timeofday_mtx);
-    update_approx_time(tv);
+#ifdef ARCH_64
+    void *new_offsetp = (void *) new_offset;
+    ASSERT(sizeof(void *) == sizeof(ErtsMonotonicTime));
+#else
+    void *new_offsetp = erts_alloc(ERTS_ALC_T_NEW_TIME_OFFSET,
+				   sizeof(ErtsMonotonicTime));
+    *((ErtsMonotonicTime *) new_offsetp) = new_offset;
+#endif
+    erts_schedule_misc_aux_work(1,
+				send_time_offset_changed_notifications,
+				new_offsetp);
 }
 
-erts_time_t
-erts_get_time(void)
+static ERTS_INLINE Eterm
+make_time_val(Process *c_p, ErtsMonotonicTime time_val)
 {
-    SysTimeval sys_tv;
-    
-    erts_smp_mtx_lock(&erts_timeofday_mtx);
-    
-    get_tolerant_timeofday(&sys_tv);
-    
-    erts_smp_mtx_unlock(&erts_timeofday_mtx);
+    Sint64 val = (Sint64) time_val;
+    Eterm *hp;
+    Uint sz;
 
-    update_approx_time(&sys_tv);
+    if (IS_SSMALL(val))
+	return make_small(val);
 
-    return sys_tv.tv_sec;
+    sz = ERTS_SINT64_HEAP_SIZE(val);
+    hp = HAlloc(c_p, sz);
+    return erts_sint64_to_big(val, &hp);
 }
 
-#ifdef HAVE_ERTS_NOW_CPU
-void erts_get_now_cpu(Uint* megasec, Uint* sec, Uint* microsec) {
-  SysCpuTime t;
-  SysTimespec tp;
+Eterm
+erts_get_monotonic_start_time(struct process *c_p)
+{
+    return make_time_val(c_p, ERTS_MONOTONIC_OFFSET_NATIVE);
+}
 
-  sys_get_proc_cputime(t, tp);
-  *microsec = (Uint)(tp.tv_nsec / 1000);
-  t = (tp.tv_sec / 1000000);
-  *megasec = (Uint)(t % 1000000);
-  *sec = (Uint)(tp.tv_sec % 1000000);
+static Eterm
+bld_monotonic_time_source(Uint **hpp, Uint *szp, Sint64 os_mtime)
+{
+#ifndef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    return NIL;
+#else
+    int i = 0;
+    Eterm k[5];
+    Eterm v[5];
+
+    if (time_sup.r.o.os_monotonic_disable)
+	return NIL;
+
+    k[i] = erts_bld_atom(hpp, szp, "function");
+    v[i++] = erts_bld_atom(hpp, szp, time_sup.r.o.os_monotonic_func);
+
+    if (time_sup.r.o.os_monotonic_clock_id) {
+	k[i] = erts_bld_atom(hpp, szp, "clock_id");
+	v[i++] = erts_bld_atom(hpp, szp, time_sup.r.o.os_monotonic_clock_id);
+    }
+
+    if (time_sup.r.o.os_monotonic_resolution) {
+	k[i] = erts_bld_atom(hpp, szp, "resolution");
+	v[i++] = erts_bld_uint64(hpp, szp, time_sup.r.o.os_monotonic_resolution);
+    }
+
+    k[i] = erts_bld_atom(hpp, szp, "parallel");
+    v[i++] = time_sup.r.o.os_monotonic_locked ? am_no : am_yes;
+
+    k[i] = erts_bld_atom(hpp, szp, "time");
+    v[i++] = erts_bld_sint64(hpp, szp, os_mtime);
+
+    return erts_bld_2tup_list(hpp, szp, (Sint) i, k, v);
+#endif
 }
+
+Eterm
+erts_monotonic_time_source(struct process *c_p)
+{
+    Uint hsz = 0;
+    Eterm *hp = NULL;
+    Sint64 os_mtime = 0;
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    if (!time_sup.r.o.os_monotonic_disable)
+	os_mtime = (Sint64) erts_os_monotonic_time();
+#endif
+
+    bld_monotonic_time_source(NULL, &hsz, os_mtime);
+    if (hsz)
+	hp = HAlloc(c_p, hsz);
+    return bld_monotonic_time_source(&hp, NULL, os_mtime);
+}
+
+
+#include "bif.h"
+
+static ERTS_INLINE Eterm
+time_unit_conversion(Process *c_p, Eterm term, ErtsMonotonicTime val, ErtsMonotonicTime muloff)
+{
+    ErtsMonotonicTime result;
+    BIF_RETTYPE ret;
+
+    if (val < 0)
+	goto trap_to_erlang_code;
+
+    /* Convert to common user specified time units */
+    switch (term) {
+    case am_seconds:
+    case make_small(1):
+	result = ERTS_MONOTONIC_TO_SEC(val) + muloff*ERTS_MONOTONIC_OFFSET_SEC;
+	ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+	break;
+    case am_milli_seconds:
+    case make_small(1000):
+	result = ERTS_MONOTONIC_TO_MSEC(val) + muloff*ERTS_MONOTONIC_OFFSET_MSEC;
+	ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+	break;
+    case am_micro_seconds:
+    case make_small(1000*1000):
+	result = ERTS_MONOTONIC_TO_USEC(val) + muloff*ERTS_MONOTONIC_OFFSET_USEC;
+	ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+	break;
+#ifdef ARCH_64
+    case am_nano_seconds:
+    case make_small(1000*1000*1000):
+	result = ERTS_MONOTONIC_TO_NSEC(val) + muloff*ERTS_MONOTONIC_OFFSET_NSEC;
+	ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+	break;
 #endif
+    default: {
+	Eterm value, native_res;
+#ifndef ARCH_64
+	Sint user_res;
+	if (term == am_nano_seconds)
+	    goto to_nano_seconds;
+	if (term_to_Sint(term, &user_res)) {
+	    if (user_res == 1000*1000*1000) {
+	    to_nano_seconds:
+		result = (ERTS_MONOTONIC_TO_NSEC(val)
+			  + muloff*ERTS_MONOTONIC_OFFSET_NSEC);
+		ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+		break;
+	    }
+	    if (user_res <= 0)
+		goto badarg;
+	}
+#else
+	if (is_small(term)) {
+	    if (signed_val(term) <= 0)
+		goto badarg;
+	}
+#endif
+	else if (is_big(term)) {
+	    if (big_sign(term))
+		goto badarg;
+	}
+	else {
+	badarg:
+	    ERTS_BIF_PREP_ERROR(ret, c_p, BADARG);
+	    break;
+	}
+
+	trap_to_erlang_code:
+	/* Do it in erlang code instead; pass along values to use... */
+	value = make_time_val(c_p, val + muloff*ERTS_MONOTONIC_OFFSET_NATIVE);
+	native_res = make_time_val(c_p, ERTS_MONOTONIC_TIME_UNIT);
+
+	ERTS_BIF_PREP_TRAP3(ret, erts_convert_time_unit_trap, c_p,
+			    value, native_res, term);
+
+	break;
+    }
+    }
+
+    return ret;
+}
+
+/* Built in functions */
+
+BIF_RETTYPE monotonic_time_0(BIF_ALIST_0)
+{
+    ErtsMonotonicTime mtime = time_sup.r.o.get_time();
+    mtime += ERTS_MONOTONIC_OFFSET_NATIVE;
+    BIF_RET(make_time_val(BIF_P, mtime));
+}
+
+BIF_RETTYPE monotonic_time_1(BIF_ALIST_1)
+{
+    BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, time_sup.r.o.get_time(), 1));
+}
+
+BIF_RETTYPE system_time_0(BIF_ALIST_0)
+{
+    ErtsMonotonicTime mtime, offset;
+    mtime = time_sup.r.o.get_time();
+    offset = get_time_offset();
+    BIF_RET(make_time_val(BIF_P, mtime + offset));
+}
+
+BIF_RETTYPE system_time_1(BIF_ALIST_0)
+{
+    ErtsMonotonicTime mtime, offset;
+    mtime = time_sup.r.o.get_time();
+    offset = get_time_offset();
+    BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, mtime + offset, 0));
+}
+
+BIF_RETTYPE erts_internal_time_unit_0(BIF_ALIST_0)
+{
+    BIF_RET(make_time_val(BIF_P, ERTS_MONOTONIC_TIME_UNIT));
+}
+
+BIF_RETTYPE time_offset_0(BIF_ALIST_0)
+{
+    ErtsMonotonicTime time_offset = get_time_offset();
+    time_offset -= ERTS_MONOTONIC_OFFSET_NATIVE;
+    BIF_RET(make_time_val(BIF_P, time_offset));
+}
+
+BIF_RETTYPE time_offset_1(BIF_ALIST_1)
+{
+    BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, get_time_offset(), -1));
+}
+
+
+BIF_RETTYPE timestamp_0(BIF_ALIST_0)
+{
+    Eterm *hp, res;
+    ErtsMonotonicTime stime, mtime, all_sec, offset;
+    Uint mega_sec, sec, micro_sec;
+
+    mtime = time_sup.r.o.get_time();
+    offset = get_time_offset();
+    stime = ERTS_MONOTONIC_TO_USEC(mtime + offset);
+    all_sec = stime / ERTS_MONOTONIC_TIME_MEGA;
+    mega_sec = (Uint) (stime / ERTS_MONOTONIC_TIME_TERA);
+    sec = (Uint) (all_sec - (((ErtsMonotonicTime) mega_sec)
+			     * ERTS_MONOTONIC_TIME_MEGA));
+    micro_sec = (Uint) (stime - all_sec*ERTS_MONOTONIC_TIME_MEGA);
+
+    ASSERT(((ErtsMonotonicTime) mega_sec)*ERTS_MONOTONIC_TIME_TERA
+	   + ((ErtsMonotonicTime) sec)*ERTS_MONOTONIC_TIME_MEGA
+	   + micro_sec == stime);
+
+    /*
+     * Mega seconds is the only value that potentially
+     * ever could be a bignum. However, that wont happen
+     * during at least the next 4 million years...
+     *
+     * (System time will also have wrapped in the
+     * 64-bit integer before we get there...)
+     */
+
+    ASSERT(IS_USMALL(0, mega_sec));
+    ASSERT(IS_USMALL(0, sec));
+    ASSERT(IS_USMALL(0, micro_sec));
+
+    hp = HAlloc(BIF_P, 4);
+    res = TUPLE3(hp,
+		 make_small(mega_sec),
+		 make_small(sec),
+		 make_small(micro_sec));
+    BIF_RET(res);
+}
+
+BIF_RETTYPE os_system_time_0(BIF_ALIST_0)
+{
+    ErtsMonotonicTime stime;
+    SysTimeval tod;
+    sys_gettimeofday(&tod);
+    stime = ERTS_SEC_TO_MONOTONIC(tod.tv_sec);
+    stime += ERTS_USEC_TO_MONOTONIC(tod.tv_usec);
+    BIF_RET(make_time_val(BIF_P, stime));
+}
+
+BIF_RETTYPE os_system_time_1(BIF_ALIST_0)
+{
+    ErtsMonotonicTime stime;
+    SysTimeval tod;
+    sys_gettimeofday(&tod);
+    stime = ERTS_SEC_TO_MONOTONIC(tod.tv_sec);
+    stime += ERTS_USEC_TO_MONOTONIC(tod.tv_usec);
+    BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, stime, 0));
+}
+
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 42daa2c9ef..634fe533d0 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -348,8 +348,6 @@ extern Uint display_items;	/* no of items to display in traces etc */
 extern int erts_backtrace_depth;
 extern erts_smp_atomic32_t erts_max_gen_gcs;
 
-extern int erts_disable_tolerant_timeofday;
-
 extern int bif_reductions;      /* reductions + fcalls (when doing call_bif) */
 extern int stackdump_on_exit;
 
@@ -789,9 +787,6 @@ erts_bld_port_info(Eterm **hpp,
 void erts_bif_info_init(void);
 
 /* bif.c */
-Eterm erts_make_ref(Process *);
-Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE]);
-void erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS]);
 
 ERTS_GLB_INLINE Eterm
 erts_proc_store_ref(Process *c_p, Uint32 ref[ERTS_MAX_REF_NUMBERS]);
@@ -1310,7 +1305,9 @@ erts_alloc_message_heap_state(Uint size,
     state = erts_smp_atomic32_read_acqb(&receiver->state);
     if (statep)
 	*statep = state;
-    if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT))
+    if (state & (ERTS_PSFLG_OFF_HEAP_MSGS
+		 | ERTS_PSFLG_EXITING
+		 | ERTS_PSFLG_PENDING_EXIT))
 	goto allocate_in_mbuf;
 #endif
 
@@ -1330,7 +1327,9 @@ erts_alloc_message_heap_state(Uint size,
 	state = erts_smp_atomic32_read_nob(&receiver->state);
 	if (statep)
 	    *statep = state;
-	if ((state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT))
+	if ((state & (ERTS_PSFLG_OFF_HEAP_MSGS
+		      | ERTS_PSFLG_EXITING
+		      | ERTS_PSFLG_PENDING_EXIT))
 	    || (receiver->flags & F_DISABLE_GC)
 	    || HEAP_LIMIT(receiver) - HEAP_TOP(receiver) <= size) {
 	    /*
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index fb0edbcb1a..8ffe718334 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -47,6 +47,7 @@
 #include "external.h"
 #include "dtrace-wrapper.h"
 #include "erl_map.h"
+#include "erl_bif_unique.h"
 
 extern ErlDrvEntry fd_driver_entry;
 #ifndef __OSE__
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index d2a8b9e7f4..aeb28e72f3 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -21,6 +21,25 @@
 #define __SYS_H__
 
 
+#if defined(DEBUG) || defined(ERTS_ENABLE_LOCK_CHECK)
+#  undef ERTS_CAN_INLINE
+#  define ERTS_CAN_INLINE 0
+#  undef ERTS_INLINE
+#  define ERTS_INLINE
+#endif
+
+#if ERTS_CAN_INLINE
+#define ERTS_GLB_INLINE static ERTS_INLINE
+#else
+#define ERTS_GLB_INLINE
+#endif
+
+#if ERTS_CAN_INLINE || defined(ERTS_DO_INCL_GLB_INLINE_FUNC_DEF) 
+#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 1
+#else
+#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 0
+#endif
+
 #if defined(VALGRIND) && !defined(NO_FPE_SIGNALS)
 #  define NO_FPE_SIGNALS
 #endif
@@ -132,24 +151,8 @@ typedef ERTS_SYS_FD_TYPE ErtsSysFdType;
 #  endif
 #endif
 
-#if defined(DEBUG) || defined(ERTS_ENABLE_LOCK_CHECK)
-#  undef ERTS_CAN_INLINE
-#  define ERTS_CAN_INLINE 0
-#  undef ERTS_INLINE
-#  define ERTS_INLINE
-#endif
-
-#if ERTS_CAN_INLINE
-#define ERTS_GLB_INLINE static ERTS_INLINE
-#else
-#define ERTS_GLB_INLINE
-#endif
-
-#if ERTS_CAN_INLINE || defined(ERTS_DO_INCL_GLB_INLINE_FUNC_DEF) 
-#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 1
-#else
-#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 0
-#endif
+#define ERTS_MK_VSN_INT(Major, Minor, Build) \
+    ((((Major) & 0x3ff) << 20) | (((Minor) & 0x3ff) << 10) | ((Build) & 0x3ff))
 
 #ifndef ERTS_EXIT_AFTER_DUMP
 #  define ERTS_EXIT_AFTER_DUMP exit
@@ -385,17 +388,45 @@ typedef Sint SWord;
 typedef UWord BeamInstr;
 
 #ifndef HAVE_INT64
-#if SIZEOF_LONG == 8
-#define HAVE_INT64 1
+#  if SIZEOF_LONG == 8
+#    define HAVE_INT64 1
 typedef unsigned long Uint64;
 typedef long          Sint64;
-#elif SIZEOF_LONG_LONG == 8
-#define HAVE_INT64 1
+#    ifdef ULONG_MAX
+#      define ERTS_UINT64_MAX ULONG_MAX
+#    endif
+#    ifdef LONG_MAX
+#      define ERTS_SINT64_MAX LONG_MAX
+#    endif
+#    ifdef LONG_MIN
+#      define ERTS_SINT64_MIN LONG_MIN
+#    endif
+#  elif SIZEOF_LONG_LONG == 8
+#    define HAVE_INT64 1
 typedef unsigned long long Uint64;
 typedef long long          Sint64;
-#else
-#define HAVE_INT64 0
+#    ifdef ULLONG_MAX
+#      define ERTS_UINT64_MAX ULLONG_MAX
+#    endif
+#    ifdef LLONG_MAX
+#      define ERTS_SINT64_MAX LLONG_MAX
+#    endif
+#    ifdef LLONG_MIN
+#      define ERTS_SINT64_MIN LLONG_MIN
+#    endif
+#  else
+#    error "No 64-bit integer type found"
+#  endif
+#endif
+
+#ifndef ERTS_UINT64_MAX
+#  define ERTS_UINT64_MAX (~((Uint64) 0))
 #endif
+#ifndef ERTS_SINT64_MAX
+#  define ERTS_SINT64_MAX ((Sint64) ((((Uint64) 1) << 63)-1))
+#endif
+#ifndef ERTS_SINT64_MIN
+#  define ERTS_SINT64_MIN (-1*(((Sint64) 1) << 63))
 #endif
 
 #if SIZEOF_LONG == 4
@@ -672,10 +703,31 @@ extern char *erts_default_arg0;
 
 extern char os_type[];
 
-extern int sys_init_time(void);
+typedef enum {
+    ERTS_NO_TIME_WARP_MODE,
+    ERTS_SINGLE_TIME_WARP_MODE,
+    ERTS_MULTI_TIME_WARP_MODE
+} ErtsTimeWarpMode;
+
+typedef struct {
+    int have_os_monotonic;
+    ErtsMonotonicTime os_monotonic_time_unit;
+    ErtsMonotonicTime sys_clock_resolution;
+    struct {
+	Uint64 resolution;
+	char *func;
+	char *clock_id;
+	int locked_use;
+    } os_monotonic_info;
+} ErtsSysInitTimeResult;
+
+#define ERTS_SYS_INIT_TIME_RESULT_INITER \
+    {0, (ErtsMonotonicTime) -1, (ErtsMonotonicTime) 1}
+
+extern void sys_init_time(ErtsSysInitTimeResult *);
 extern void erts_deliver_time(void);
 extern void erts_time_remaining(SysTimeval *);
-extern int erts_init_time_sup(void);
+extern int erts_init_time_sup(int, ErtsTimeWarpMode);
 extern void erts_sys_init_float(void);
 extern void erts_thread_init_float(void);
 extern void erts_thread_disable_fpe(void);
@@ -726,7 +778,7 @@ extern char *erts_sys_ddll_error(int code);
 
 void erts_sys_schedule_interrupt(int set);
 #ifdef ERTS_SMP
-void erts_sys_schedule_interrupt_timed(int set, erts_short_time_t msec);
+void erts_sys_schedule_interrupt_timed(int, ErtsMonotonicTime);
 void erts_sys_main_thread(void);
 #endif
 
@@ -765,6 +817,7 @@ int univ_to_local(
 int local_to_univ(Sint *year, Sint *month, Sint *day, 
 		  Sint *hour, Sint *minute, Sint *second, int isdst);
 void get_now(Uint*, Uint*, Uint*);
+ErtsMonotonicTime erts_get_monotonic_time(void);
 void get_sys_now(Uint*, Uint*, Uint*);
 void set_break_quit(void (*)(void), void (*)(void));
 
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c
index 2fd8e0cf00..9f997e1d0b 100644
--- a/erts/emulator/beam/time.c
+++ b/erts/emulator/beam/time.c
@@ -83,7 +83,8 @@
 #define ASSERT_NO_LOCKED_LOCKS
 #endif
 
-static erts_smp_mtx_t tiw_lock;
+#define ERTS_MONOTONIC_DAY ERTS_SEC_TO_MONOTONIC(60*60*24)
+#define ERTS_CLKTCKS_DAY ERTS_MONOTONIC_TO_CLKTCKS(ERTS_MONOTONIC_DAY)
 
 
 /* BEGIN tiw_lock protected variables 
@@ -91,18 +92,12 @@ static erts_smp_mtx_t tiw_lock;
 ** The individual timer cells in tiw are also protected by the same mutex.
 */
 
+/* timing wheel size NEED to be a power of 2 */
 #ifdef SMALL_MEMORY
-#define TIW_SIZE 8192
+#define TIW_SIZE (1 << 13)
 #else
-#define TIW_SIZE 65536		/* timing wheel size (should be a power of 2) */
+#define TIW_SIZE (1 << 20)
 #endif
-static ErlTimer** tiw;		/* the timing wheel, allocated in init_time() */
-static Uint tiw_pos;		/* current position in wheel */
-static Uint tiw_nto;		/* number of timeouts in wheel */
-static Uint tiw_min;
-static ErlTimer *tiw_min_ptr;
-
-/* END tiw_lock protected variables */
 
 /* Actual interval time chosen by sys_init_time() */
 
@@ -114,83 +109,135 @@ static int tiw_itime; /* Constant after init */
 #  define TIW_ITIME tiw_itime
 #endif
 
-erts_smp_atomic32_t do_time;	/* set at clock interrupt */
-static ERTS_INLINE erts_short_time_t do_time_read(void)
+struct ErtsTimerWheel_ {
+    ErlTimer *w[TIW_SIZE];
+    ErtsMonotonicTime pos;
+    Uint nto;
+    struct {
+	ErlTimer *head;
+	ErlTimer **tail;
+	Uint nto;
+    } at_once;
+    int true_next_timeout_time;
+    ErtsMonotonicTime next_timeout_time;
+    erts_atomic64_t next_timeout;
+    erts_smp_atomic32_t is_bumping;
+    erts_smp_mtx_t lock;
+};
+
+ErtsTimerWheel *erts_default_timer_wheel; /* managed by aux thread */
+
+static ERTS_INLINE ErtsTimerWheel *
+get_timer_wheel(ErlTimer *p)
+{
+    return (ErtsTimerWheel *) erts_smp_atomic_read_acqb(&p->wheel);
+}
+
+static ERTS_INLINE void
+set_timer_wheel(ErlTimer *p, ErtsTimerWheel *tiw)
 {
-    return erts_smp_atomic32_read_acqb(&do_time);
+    erts_smp_atomic_set_relb(&p->wheel, (erts_aint_t) tiw);
 }
 
-static ERTS_INLINE erts_short_time_t do_time_update(void)
+static ERTS_INLINE void
+init_next_timeout(ErtsTimerWheel *tiw,
+		  ErtsMonotonicTime time)
 {
-    return do_time_read();
+    erts_atomic64_init_nob(&tiw->next_timeout,
+			   (erts_aint64_t) time);
 }
 
-static ERTS_INLINE void do_time_init(void)
+static ERTS_INLINE void
+set_next_timeout(ErtsTimerWheel *tiw,
+		 ErtsMonotonicTime time,
+		 int true_timeout)
 {
-    erts_smp_atomic32_init_nob(&do_time, 0);
+    tiw->true_next_timeout_time = true_timeout;
+    tiw->next_timeout_time = time;
+    erts_atomic64_set_relb(&tiw->next_timeout,
+			   (erts_aint64_t) time);
 }
 
 /* get the time (in units of TIW_ITIME) to the next timeout,
    or -1 if there are no timeouts                     */
 
-static erts_short_time_t next_time_internal(void) /* PRE: tiw_lock taken by caller */
+static ERTS_INLINE ErtsMonotonicTime
+find_next_timeout(ErtsTimerWheel *tiw,
+		  ErtsMonotonicTime curr_time,
+		  ErtsMonotonicTime max_search_time)
 {
-    int i, tm, nto;
-    Uint32 min;
-    ErlTimer* p;
-    erts_short_time_t dt;
-  
-    if (tiw_nto == 0)
-	return -1;	/* no timeouts in wheel */
+    int start_ix, tiw_pos_ix;
+    ErlTimer *p;
+    int true_min_timeout;
+    ErtsMonotonicTime min_timeout, min_timeout_pos, slot_timeout_pos, timeout_limit;
+
+    ERTS_SMP_LC_ASSERT(erts_smp_lc_mtx_is_locked(&tiw->lock));
+
+    if (tiw->true_next_timeout_time)
+	return tiw->next_timeout_time;
 
-    if (tiw_min_ptr) {
-	min = tiw_min;
-	dt  = do_time_read();
-	return ((min >= dt) ? (min - dt) : 0);
+    /* We never set next timeout beyond timeout_limit */
+    timeout_limit = curr_time + ERTS_MONOTONIC_DAY;
+
+    if (tiw->nto == 0) { /* no timeouts in wheel */
+	true_min_timeout = tiw->true_next_timeout_time = 0;
+	min_timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(timeout_limit);
+	goto found_next;
     }
-  
-    /* start going through wheel to find next timeout */
-    tm = nto = 0;
-    min = (Uint32) -1;	/* max Uint32 */
-    i = tiw_pos;
+
+    /*
+     * Don't want others entering trying to bump
+     * timers while we are checking...
+     */
+    set_next_timeout(tiw, timeout_limit, 0);
+
+    true_min_timeout = 1;
+    slot_timeout_pos = tiw->pos;
+    min_timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(curr_time + max_search_time);
+
+    start_ix = tiw_pos_ix = (int) (tiw->pos & (TIW_SIZE-1));
+
     do {
-	p = tiw[i];
-	while (p != NULL) {
-	    nto++;
-	    if (p->count == 0) {
-		/* found next timeout */
-		dt = do_time_read();
-		/* p->count is zero */
-		tiw_min_ptr = p;
-		tiw_min     = tm;
-		return ((tm >= dt) ? (tm - dt) : 0);
-	    } else {
-		/* keep shortest time in 'min' */
-		if (tm + p->count*TIW_SIZE < min) {
-		    min = tm + p->count*TIW_SIZE;
-		    tiw_min_ptr = p;
-		    tiw_min     = min;
-		}
+	slot_timeout_pos++;
+	if (slot_timeout_pos >= min_timeout_pos) {
+	    true_min_timeout = 0;
+	    break;
+	}
+
+	p = tiw->w[tiw_pos_ix];
+
+	while (p) {
+	    ErtsMonotonicTime timeout_pos;
+	    ASSERT(p != p->next);
+	    timeout_pos = p->timeout_pos;
+	    if (min_timeout_pos > timeout_pos) {
+		min_timeout_pos = timeout_pos;
+		if (min_timeout_pos <= slot_timeout_pos)
+		    goto found_next;
 	    }
 	    p = p->next;
 	}
-	/* when we have found all timeouts the shortest time will be in min */
-	if (nto == tiw_nto) break;
-	tm++;
-	i = (i + 1) % TIW_SIZE;
-    } while (i != tiw_pos);
-    dt = do_time_read();
-    if (min <= (Uint32) dt)
-	return 0;
-    if ((min - (Uint32) dt) > (Uint32) ERTS_SHORT_TIME_T_MAX)
-	return ERTS_SHORT_TIME_T_MAX;
-    return (erts_short_time_t) (min - (Uint32) dt);
+
+	tiw_pos_ix++;
+	if (tiw_pos_ix == TIW_SIZE)
+	    tiw_pos_ix = 0;
+    } while (start_ix != tiw_pos_ix);
+
+found_next:
+
+    min_timeout = ERTS_CLKTCKS_TO_MONOTONIC(min_timeout_pos);
+    if (min_timeout != tiw->next_timeout_time)
+	set_next_timeout(tiw, min_timeout, true_min_timeout);
+
+    return min_timeout;
 }
 
-static void remove_timer(ErlTimer *p) {
+static void
+remove_timer(ErtsTimerWheel *tiw, ErlTimer *p)
+{
     /* first */
     if (!p->prev) {
-	tiw[p->slot] = p->next;
+	tiw->w[p->slot] = p->next;
 	if(p->next)
 	    p->next->prev = NULL;
     } else {
@@ -207,79 +254,164 @@ static void remove_timer(ErlTimer *p) {
 
     p->next = NULL;
     p->prev = NULL;
-    /* Make sure cancel callback isn't called */
-    p->active = 0;
-    tiw_nto--;
+
+    set_timer_wheel(p, NULL);
+    tiw->nto--;
+}
+
+ErtsMonotonicTime
+erts_check_next_timeout_time(ErtsTimerWheel *tiw,
+			     ErtsMonotonicTime max_search_time)
+{
+    ErtsMonotonicTime next, curr;
+
+    curr = erts_get_monotonic_time();
+
+    erts_smp_mtx_lock(&tiw->lock);
+
+    next = find_next_timeout(tiw, curr, max_search_time);
+
+    erts_smp_mtx_unlock(&tiw->lock);
+
+    return next;
 }
 
-/* Private export to erl_time_sup.c */
-erts_short_time_t erts_next_time(void)
+#ifndef DEBUG
+#define ERTS_DBG_CHK_SAFE_TO_SKIP_TO(TIW, TO) ((void) 0)
+#else
+#define ERTS_DBG_CHK_SAFE_TO_SKIP_TO(TIW, TO) debug_check_safe_to_skip_to((TIW), (TO))
+static void
+debug_check_safe_to_skip_to(ErtsTimerWheel *tiw, ErtsMonotonicTime skip_to_pos)
 {
-    erts_short_time_t ret;
+    int slots, ix;
+    ErlTimer *tmr;
+    ErtsMonotonicTime tmp;
+
+    ix = (int) (tiw->pos & (TIW_SIZE-1));
+    tmp = skip_to_pos - tiw->pos;
+    ASSERT(tmp >= 0);
+    if (tmp < (ErtsMonotonicTime) TIW_SIZE)
+	slots = (int) tmp;
+    else
+	slots = TIW_SIZE;
 
-    erts_smp_mtx_lock(&tiw_lock);
-    (void)do_time_update();
-    ret = next_time_internal();
-    erts_smp_mtx_unlock(&tiw_lock);
-    return ret;
+     while (slots > 0) {
+	tmr = tiw->w[ix];
+	while (tmr) {
+	    ASSERT(tmr->timeout_pos > skip_to_pos);
+	    tmr = tmr->next;
+	}
+	ix++;
+	if (ix == TIW_SIZE)
+	    ix = 0;
+	slots--;
+    }
 }
+#endif
 
-static ERTS_INLINE void bump_timer_internal(erts_short_time_t dt) /* PRE: tiw_lock is write-locked */
+void
+erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time)
 {
-    Uint keep_pos;
-    Uint count;
-    ErlTimer *p, **prev, *timeout_head, **timeout_tail;
-    Uint dtime = (Uint) dt;  
-
-    /* no need to bump the position if there aren't any timeouts */
-    if (tiw_nto == 0) {
-	erts_smp_mtx_unlock(&tiw_lock);
-	return;
+    int tiw_pos_ix, slots;
+    ErlTimer *p, *timeout_head, **timeout_tail;
+    ErtsMonotonicTime bump_to, tmp_slots;
+
+    if (erts_smp_atomic32_cmpxchg_nob(&tiw->is_bumping, 1, 0) != 0)
+	return; /* Another thread is currently bumping... */
+
+    bump_to = ERTS_MONOTONIC_TO_CLKTCKS(curr_time);
+
+    erts_smp_mtx_lock(&tiw->lock);
+
+    if (tiw->pos >= bump_to) {
+	timeout_head = NULL;
+	goto done;
     }
 
-    /* if do_time > TIW_SIZE we want to go around just once */
-    count = (Uint)(dtime / TIW_SIZE) + 1;
-    keep_pos = (tiw_pos + dtime) % TIW_SIZE;
-    if (dtime > TIW_SIZE) dtime = TIW_SIZE;
-  
-    timeout_head = NULL;
-    timeout_tail = &timeout_head;
-    while (dtime > 0) {
-	/* this is to decrease the counters with the right amount */
-	/* when dtime >= TIW_SIZE */
-	if (tiw_pos == keep_pos) count--;
-	prev = &tiw[tiw_pos];
-	while ((p = *prev) != NULL) {
-	    ASSERT( p != p->next);
-	    if (p->count < count) {     /* we have a timeout */
-		/* remove min time */
-		if (tiw_min_ptr == p) {
-		    tiw_min_ptr = NULL;
-		    tiw_min = 0;
-		}
+    /* Don't want others here while we are bumping... */
+    set_next_timeout(tiw, curr_time + ERTS_MONOTONIC_DAY, 0);
 
+    if (!tiw->at_once.head) {
+	timeout_head = NULL;
+	timeout_tail = &timeout_head;
+    }
+    else {
+	ASSERT(tiw->nto >= tiw->at_once.nto);
+	timeout_head = tiw->at_once.head;
+	timeout_tail = tiw->at_once.tail;
+	tiw->nto -= tiw->at_once.nto;
+	tiw->at_once.head = NULL;
+	tiw->at_once.tail = &tiw->at_once.head;
+	tiw->at_once.nto = 0;
+    }
+
+    if (tiw->nto == 0) {
+	ERTS_DBG_CHK_SAFE_TO_SKIP_TO(tiw, bump_to);
+	tiw->pos = bump_to;
+	goto done;
+    }
+
+    if (tiw->true_next_timeout_time) {
+	ErtsMonotonicTime skip_until_pos;
+	/*
+	 * No need inspecting slots where we know no timeouts
+	 * to trigger should reside.
+	 */
+
+	skip_until_pos = ERTS_MONOTONIC_TO_CLKTCKS(tiw->next_timeout_time);
+	if (skip_until_pos > bump_to)
+	    skip_until_pos = bump_to;
+
+	ERTS_DBG_CHK_SAFE_TO_SKIP_TO(tiw, skip_until_pos);
+	ASSERT(skip_until_pos > tiw->pos);
+
+	tiw->pos = skip_until_pos - 1;
+    }
+
+    tiw_pos_ix = (int) ((tiw->pos+1) & (TIW_SIZE-1));
+    tmp_slots = (bump_to - tiw->pos);
+    if (tmp_slots < (ErtsMonotonicTime) TIW_SIZE)
+	slots = (int) tmp_slots;
+    else
+	slots = TIW_SIZE;
+ 
+    while (slots > 0) {
+	p = tiw->w[tiw_pos_ix];
+	while (p) {
+	    ErlTimer *next = p->next;
+	    ASSERT(p != next);
+	    if (p->timeout_pos <= bump_to) { /* we have a timeout */
 		/* Remove from list */
-		remove_timer(p);
+		remove_timer(tiw, p);
 		*timeout_tail = p;	/* Insert in timeout queue */
 		timeout_tail = &p->next;
 	    }
-	    else {
-		/* no timeout, just decrease counter */
-		p->count -= count;
-		prev = &p->next;
-	    }
+	    p = next;
 	}
-	tiw_pos = (tiw_pos + 1) % TIW_SIZE;
-	dtime--;
+	tiw_pos_ix++;
+	if (tiw_pos_ix == TIW_SIZE)
+	    tiw_pos_ix = 0;
+	slots--;
     }
-    tiw_pos = keep_pos;
-    if (tiw_min_ptr)
-	tiw_min -= dt;
-    
-    erts_smp_mtx_unlock(&tiw_lock);
+
+    ASSERT(tmp_slots >= (ErtsMonotonicTime) TIW_SIZE
+	   || tiw_pos_ix == (int) ((bump_to+1) & (TIW_SIZE-1)));
+
+    tiw->pos = bump_to;
+
+    /* Search at most two seconds ahead... */
+    (void) find_next_timeout(tiw, curr_time, ERTS_SEC_TO_MONOTONIC(2));
+
+done:
+
+    erts_smp_mtx_unlock(&tiw->lock);
     
+    erts_smp_atomic32_set_nob(&tiw->is_bumping, 0);
+
     /* Call timedout timers callbacks */
     while (timeout_head) {
+	ErlTimeoutProc timeout;
+	void *arg;
 	p = timeout_head;
 	timeout_head = p->next;
 	/* Here comes hairy use of the timer fields!
@@ -288,35 +420,69 @@ static ERTS_INLINE void bump_timer_internal(erts_short_time_t dt) /* PRE: tiw_lo
 	 * accesses any field until the ->timeout
 	 * callback is called.
 	 */
+	ASSERT(p->timeout_pos <= bump_to);
 	p->next = NULL;
 	p->prev = NULL;
 	p->slot = 0;
-	(*p->timeout)(p->arg);
+	timeout = p->timeout;
+	arg = p->arg;
+	(*timeout)(arg);
     }
 }
 
-void erts_bump_timer(erts_short_time_t dt) /* dt is value from do_time */
+Uint
+erts_timer_wheel_memory_size(void)
+{
+#ifdef ERTS_SMP
+    return sizeof(ErtsTimerWheel)*(1 + erts_no_schedulers);
+#else
+    return sizeof(ErtsTimerWheel);
+#endif
+}
+
+ErtsTimerWheel *
+erts_create_timer_wheel(int no)
 {
-    erts_smp_mtx_lock(&tiw_lock);
-    bump_timer_internal(dt);
+    ErtsMonotonicTime mtime;
+    int i;
+    ErtsTimerWheel *tiw;
+    tiw = (ErtsTimerWheel *) erts_alloc(ERTS_ALC_T_TIMER_WHEEL,
+					sizeof(ErtsTimerWheel));
+    for(i = 0; i < TIW_SIZE; i++)
+	tiw->w[i] = NULL;
+
+    erts_smp_atomic32_init_nob(&tiw->is_bumping, 0);
+    erts_smp_mtx_init_x(&tiw->lock, "timer_wheel", make_small(no));
+
+    mtime = erts_get_monotonic_time();
+    tiw->pos = ERTS_MONOTONIC_TO_CLKTCKS(mtime);
+    tiw->nto = 0;
+    tiw->at_once.head = NULL;
+    tiw->at_once.tail = &tiw->at_once.head;
+    tiw->at_once.nto = 0;
+    tiw->true_next_timeout_time = 0;
+    tiw->next_timeout_time = mtime + ERTS_MONOTONIC_DAY;
+    init_next_timeout(tiw, mtime + ERTS_MONOTONIC_DAY);
+    return tiw;
 }
 
-Uint
-erts_timer_wheel_memory_size(void)
+ErtsNextTimeoutRef
+erts_get_next_timeout_reference(ErtsTimerWheel *tiw)
 {
-    return (Uint) TIW_SIZE * sizeof(ErlTimer*);
+    return (ErtsNextTimeoutRef) &tiw->next_timeout;
 }
 
+
 /* this routine links the time cells into a free list at the start
    and sets the time queue as empty */
 void
-erts_init_time(void)
+erts_init_time(int time_correction, ErtsTimeWarpMode time_warp_mode)
 {
-    int i, itime;
+    int itime;
 
     /* system dependent init; must be done before do_time_init()
        if timer thread is enabled */
-    itime = erts_init_time_sup();
+    itime = erts_init_time_sup(time_correction, time_warp_mode);
 #ifdef TIW_ITIME_IS_CONSTANT 
     if (itime != TIW_ITIME) {
 	erl_exit(ERTS_ABORT_EXIT, "timer resolution mismatch %d != %d", itime, TIW_ITIME);
@@ -325,117 +491,110 @@ erts_init_time(void)
     tiw_itime = itime;
 #endif
 
-    erts_smp_mtx_init(&tiw_lock, "timer_wheel");
-
-    tiw = (ErlTimer**) erts_alloc(ERTS_ALC_T_TIMER_WHEEL,
-				  TIW_SIZE * sizeof(ErlTimer*));
-    for(i = 0; i < TIW_SIZE; i++)
-	tiw[i] = NULL;
-    do_time_init();
-    tiw_pos = tiw_nto = 0;
-    tiw_min_ptr = NULL;
-    tiw_min = 0;
+    erts_default_timer_wheel = erts_create_timer_wheel(0);
 }
 
+void
+erts_set_timer(ErlTimer *p, ErlTimeoutProc timeout,
+	       ErlCancelProc cancel, void *arg, Uint to)
+{
+    ErtsMonotonicTime timeout_time, timeout_pos;
+    ErtsMonotonicTime curr_time;
+    ErtsTimerWheel *tiw;
+    ErtsSchedulerData *esdp;
+
+    curr_time = erts_get_monotonic_time();
+    esdp = erts_get_scheduler_data();
+    if (esdp)
+	tiw = esdp->timer_wheel;
+    else
+	tiw = erts_default_timer_wheel;
 
+    erts_smp_mtx_lock(&tiw->lock);
 
+    if (get_timer_wheel(p))
+	ERTS_INTERNAL_ERROR("Double set timer");
 
-/*
-** Insert a process into the time queue, with a timeout 't'
-*/
-static void
-insert_timer(ErlTimer* p, Uint t)
-{
-    Uint tm;
-    Uint64 ticks;
+    p->timeout = timeout;
+    p->cancel = cancel;
+    p->arg = arg;
 
-    /* The current slot (tiw_pos) in timing wheel is the next slot to be
-     * be processed. Hence no extra time tick is needed.
-     *
-     * (x + y - 1)/y is precisely the "number of bins" formula.
-     */
-    ticks = (t + (TIW_ITIME - 1)) / TIW_ITIME;
+    if (to == 0) {
+	timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(curr_time);
+	tiw->nto++;
+	tiw->at_once.nto++;
+	*tiw->at_once.tail = p;
+	p->next = NULL;
+	p->timeout_pos = timeout_pos;
+	timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(timeout_pos);
+    }
+    else {
+	int tm;
+	ErtsMonotonicTime ticks;
 
-    /* 
-     * Ticks must be a Uint64, or the addition may overflow here,
-     * resulting in an incorrect value for p->count below.
-     */
-    ticks += do_time_update(); /* Add backlog of unprocessed time */
-    
-    /* calculate slot */
-    tm = (ticks + tiw_pos) % TIW_SIZE;
-    p->slot = (Uint) tm;
-    p->count = (Uint) (ticks / TIW_SIZE);
+	ticks = ERTS_MSEC_TO_CLKTCKS(to);
+	timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(curr_time - 1) + 1 + ticks;
+
+	/* calculate slot */
+	tm = (int) (timeout_pos & (TIW_SIZE-1));
+	p->slot = (Uint) tm;
   
-    /* insert at head of list at slot */
-    p->next = tiw[tm];
-    p->prev = NULL;
-    if (p->next != NULL)
-	p->next->prev = p;
-    tiw[tm] = p;
+	/* insert at head of list at slot */
+	p->next = tiw->w[tm];
+	p->prev = NULL;
+	if (p->next != NULL)
+	    p->next->prev = p;
+	tiw->w[tm] = p;
 
+	tiw->nto++;
 
-    /* insert min time */
-    if ((tiw_nto == 0) || ((tiw_min_ptr != NULL) && (ticks < tiw_min))) {
-	tiw_min = ticks;
-	tiw_min_ptr = p;
-    }
-    if ((tiw_min_ptr == p) && (ticks > tiw_min)) {
-	/* some other timer might be 'min' now */
-	tiw_min = 0;
-	tiw_min_ptr = NULL;
+	timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(timeout_pos);
+	p->timeout_pos = timeout_pos;
+
+	ASSERT(ERTS_MSEC_TO_MONOTONIC(to) <= timeout_time - curr_time);
+	ASSERT(timeout_time - curr_time
+	       < ERTS_MSEC_TO_MONOTONIC(to) + ERTS_CLKTCKS_TO_MONOTONIC(1));
     }
 
-    tiw_nto++;
-}
+    if (timeout_time < tiw->next_timeout_time)
+	set_next_timeout(tiw, timeout_time, 1);
 
-void
-erts_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel,
-	      void* arg, Uint t)
-{
+    set_timer_wheel(p, tiw);
+
+    erts_smp_mtx_unlock(&tiw->lock);
 
-    erts_deliver_time();
-    erts_smp_mtx_lock(&tiw_lock);
-    if (p->active) { /* XXX assert ? */
-	erts_smp_mtx_unlock(&tiw_lock);
-	return;
-    }
-    p->timeout = timeout;
-    p->cancel = cancel;
-    p->arg = arg;
-    p->active = 1;
-    insert_timer(p, t);
-    erts_smp_mtx_unlock(&tiw_lock);
 #if defined(ERTS_SMP)
-    if (t <= (Uint) ERTS_SHORT_TIME_T_MAX)
-	erts_sys_schedule_interrupt_timed(1, (erts_short_time_t) t);
+    if (tiw == erts_default_timer_wheel)
+	erts_interupt_aux_thread_timed(timeout_time);
 #endif
+
 }
 
 void
-erts_cancel_timer(ErlTimer* p)
+erts_cancel_timer(ErlTimer *p)
 {
-    erts_smp_mtx_lock(&tiw_lock);
-    if (!p->active) { /* allow repeated cancel (drivers) */
-	erts_smp_mtx_unlock(&tiw_lock);
+    ErtsTimerWheel *tiw;
+    ErlCancelProc cancel;
+    void *arg;
+
+    tiw = get_timer_wheel(p);
+    if (!tiw)
 	return;
-    }
+    
+    erts_smp_mtx_lock(&tiw->lock);
+    if (tiw != get_timer_wheel(p))
+	cancel = NULL;
+    else {
+	remove_timer(tiw, p);
+	p->slot = 0;
 
-    /* is it the 'min' timer, remove min */
-    if (p == tiw_min_ptr) {
-	tiw_min_ptr = NULL;
-	tiw_min     = 0;
+	cancel = p->cancel;
+	arg = p->arg;
     }
+    erts_smp_mtx_unlock(&tiw->lock);
 
-    remove_timer(p);
-    p->slot = p->count = 0;
-
-    if (p->cancel != NULL) {
-	erts_smp_mtx_unlock(&tiw_lock);
-	(*p->cancel)(p->arg);
-	return;
-    }
-    erts_smp_mtx_unlock(&tiw_lock);
+    if (cancel)
+	(*cancel)(arg);
 }
 
 /*
@@ -447,59 +606,58 @@ erts_cancel_timer(ErlTimer* p)
 Uint
 erts_time_left(ErlTimer *p)
 {
-    Uint left;
-    erts_short_time_t dt;
+    ErtsTimerWheel *tiw;
+    ErtsMonotonicTime current_time, timeout_time;
 
-    erts_smp_mtx_lock(&tiw_lock);
-
-    if (!p->active) {
-	erts_smp_mtx_unlock(&tiw_lock);
+    tiw = get_timer_wheel(p);
+    if (!tiw)
 	return 0;
-    }
 
-    if (p->slot < tiw_pos)
-	left = (p->count + 1) * TIW_SIZE + p->slot - tiw_pos;
+    erts_smp_mtx_lock(&tiw->lock);
+    if (tiw != get_timer_wheel(p))
+	timeout_time = ERTS_MONOTONIC_TIME_MIN;
     else
-	left = p->count * TIW_SIZE + p->slot - tiw_pos;
-    dt = do_time_read();
-    if (left < dt)
-	left = 0;
-    else
-	left -= dt;
-
-    erts_smp_mtx_unlock(&tiw_lock);
+	timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(p->timeout_pos);
+    erts_smp_mtx_unlock(&tiw->lock);
 
-    return (Uint) left * TIW_ITIME;
+    current_time = erts_get_monotonic_time();
+    if (timeout_time <= current_time)
+	return 0;
+    return (Uint) ERTS_MONOTONIC_TO_MSEC(timeout_time - current_time);
 }
 
 #ifdef DEBUG
 void erts_p_slpq(void)
 {
+    ErtsTimerWheel *tiw = erts_default_timer_wheel;
+    ErtsMonotonicTime current_time = erts_get_monotonic_time();
     int i;
     ErlTimer* p;
   
-    erts_smp_mtx_lock(&tiw_lock);
+    erts_smp_mtx_lock(&tiw->lock);
 
     /* print the whole wheel, starting at the current position */
-    erts_printf("\ntiw_pos = %d tiw_nto %d\n", tiw_pos, tiw_nto);
-    i = tiw_pos;
-    if (tiw[i] != NULL) {
+    erts_printf("\ncurrent time = %bps tiw_pos = %d tiw_nto %d\n",
+		current_time, tiw->pos, tiw->nto);
+    i = tiw->pos;
+    if (tiw->w[i] != NULL) {
 	erts_printf("%d:\n", i);
-	for(p = tiw[i]; p != NULL; p = p->next) {
-	    erts_printf(" (count %d, slot %d)\n",
-			p->count, p->slot);
+	for(p = tiw->w[i]; p != NULL; p = p->next) {
+	    erts_printf(" (timeout time %bps, slot %d)\n",
+			ERTS_CLKTCKS_TO_MONOTONIC(p->timeout_pos),
+			p->slot);
 	}
     }
-    for(i = (i+1)%TIW_SIZE; i != tiw_pos; i = (i+1)%TIW_SIZE) {
-	if (tiw[i] != NULL) {
+    for(i = ((i+1) & (TIW_SIZE-1)); i != (tiw->pos & (TIW_SIZE-1)); i = ((i+1) & (TIW_SIZE-1))) {
+	if (tiw->w[i] != NULL) {
 	    erts_printf("%d:\n", i);
-	    for(p = tiw[i]; p != NULL; p = p->next) {
-		erts_printf(" (count %d, slot %d)\n",
-			    p->count, p->slot);
+	    for(p = tiw->w[i]; p != NULL; p = p->next) {
+		erts_printf(" (timeout time %bps, slot %d)\n",
+			    ERTS_CLKTCKS_TO_MONOTONIC(p->timeout_pos), p->slot);
 	    }
 	}
     }
 
-    erts_smp_mtx_unlock(&tiw_lock);
+    erts_smp_mtx_unlock(&tiw->lock);
 }
 #endif /* DEBUG */
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index 3549e18538..127f1e4a6a 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -49,6 +49,7 @@
 #include "beam_bp.h"
 #include "erl_ptab.h"
 #include "erl_check_io.h"
+#include "erl_bif_unique.h"
 #ifdef HIPE
 #  include "hipe_mode_switch.h"
 #endif
@@ -4510,7 +4511,7 @@ erts_create_smp_ptimer(ErtsSmpPTimer **timer_ref,
     res->timer.timeout_func = timeout_func;
     res->timer.timer_ref = timer_ref;
     res->timer.id = id;
-    res->timer.tm.active = 0; /* MUST be initalized */
+    erts_init_timer(&res->timer.tm);
 
     ASSERT(!*timer_ref);
 
@@ -5087,8 +5088,8 @@ erts_smp_ensure_later_interval_acqb(erts_interval_t *icp, Uint64 ic)
  */
 Uint64 erts_timestamp_millis(void)
 {
-#ifdef HAVE_GETHRTIME
-    return (Uint64) (sys_gethrtime() / 1000000);
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    return ERTS_MONOTONIC_TO_MSEC(erts_os_monotonic_time());
 #else
     Uint64 res;
     SysTimeval tv;
diff --git a/erts/emulator/sys/common/erl_check_io.c b/erts/emulator/sys/common/erl_check_io.c
index 0051b45b31..7be17d20bb 100644
--- a/erts/emulator/sys/common/erl_check_io.c
+++ b/erts/emulator/sys/common/erl_check_io.c
@@ -1590,9 +1590,9 @@ ERTS_CIO_EXPORT(erts_check_io_interrupt)(int set)
 
 void
 ERTS_CIO_EXPORT(erts_check_io_interrupt_timed)(int set,
-					       erts_short_time_t msec)
+					       ErtsMonotonicTime timeout_time)
 {
-    ERTS_CIO_POLL_INTR_TMD(pollset.ps, set, msec);
+    ERTS_CIO_POLL_INTR_TMD(pollset.ps, set, timeout_time);
 }
 
 void
@@ -1600,9 +1600,12 @@ ERTS_CIO_EXPORT(erts_check_io)(int do_wait)
 {
     ErtsPollResFd *pollres;
     int pollres_len;
-    SysTimeval wait_time;
+    ErtsMonotonicTime timeout_time;
     int poll_ret, i;
     erts_aint_t current_cio_time;
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+
+    ASSERT(esdp);
 
  restart:
 
@@ -1612,12 +1615,10 @@ ERTS_CIO_EXPORT(erts_check_io)(int do_wait)
 #endif
 
     /* Figure out timeout value */
-    if (do_wait) {
-	erts_time_remaining(&wait_time);
-    } else {			/* poll only */
-	wait_time.tv_sec = 0;
-	wait_time.tv_usec = 0;
-    }
+    timeout_time = (do_wait
+		    ? erts_check_next_timeout_time(esdp->timer_wheel,
+						   ERTS_SEC_TO_MONOTONIC(10*60))
+		    : ERTS_POLL_NO_TIMEOUT /* poll only */);
 
     /*
      * No need for an atomic inc op when incrementing
@@ -1640,14 +1641,12 @@ ERTS_CIO_EXPORT(erts_check_io)(int do_wait)
 
     erts_smp_atomic_set_nob(&pollset.in_poll_wait, 1);
 
-    poll_ret = ERTS_CIO_POLL_WAIT(pollset.ps, pollres, &pollres_len, &wait_time);
+    poll_ret = ERTS_CIO_POLL_WAIT(pollset.ps, pollres, &pollres_len, timeout_time);
 
 #ifdef ERTS_ENABLE_LOCK_CHECK
     erts_lc_check_exact(NULL, 0); /* No locks should be locked */
 #endif
 
-    erts_deliver_time(); /* sync the machine's idea of time */
-
 #ifdef ERTS_BREAK_REQUESTED
     if (ERTS_BREAK_REQUESTED)
 	erts_do_break_handling();
diff --git a/erts/emulator/sys/common/erl_check_io.h b/erts/emulator/sys/common/erl_check_io.h
index d01297d55c..71355965aa 100644
--- a/erts/emulator/sys/common/erl_check_io.h
+++ b/erts/emulator/sys/common/erl_check_io.h
@@ -47,8 +47,8 @@ void erts_check_io_async_sig_interrupt_nkp(void);
 #endif
 void erts_check_io_interrupt_kp(int);
 void erts_check_io_interrupt_nkp(int);
-void erts_check_io_interrupt_timed_kp(int, erts_short_time_t);
-void erts_check_io_interrupt_timed_nkp(int, erts_short_time_t);
+void erts_check_io_interrupt_timed_kp(int, ErtsMonotonicTime);
+void erts_check_io_interrupt_timed_nkp(int, ErtsMonotonicTime);
 void erts_check_io_kp(int);
 void erts_check_io_nkp(int);
 void erts_init_check_io_kp(void);
@@ -65,7 +65,7 @@ int erts_check_io_max_files(void);
 void erts_check_io_async_sig_interrupt(void);
 #endif
 void erts_check_io_interrupt(int);
-void erts_check_io_interrupt_timed(int, erts_short_time_t);
+void erts_check_io_interrupt_timed(int, ErtsMonotonicTime);
 void erts_check_io(int);
 void erts_init_check_io(void);
 
diff --git a/erts/emulator/sys/common/erl_poll.c b/erts/emulator/sys/common/erl_poll.c
index aa412a20c8..f4d4a85ca4 100644
--- a/erts/emulator/sys/common/erl_poll.c
+++ b/erts/emulator/sys/common/erl_poll.c
@@ -320,7 +320,7 @@ struct ErtsPollSet_ {
 #if defined(USE_THREADS) || ERTS_POLL_ASYNC_INTERRUPT_SUPPORT
     erts_atomic32_t wakeup_state;
 #endif
-    erts_smp_atomic32_t timeout;
+    erts_atomic64_t timeout_time;
 #ifdef ERTS_POLL_COUNT_AVOIDED_WAKEUPS
     erts_smp_atomic_t no_avoided_wakeups;
     erts_smp_atomic_t no_avoided_interrupts;
@@ -384,6 +384,26 @@ static void check_poll_status(ErtsPollSet ps);
 static void print_misc_debug_info(void);
 #endif
 
+static ERTS_INLINE void
+init_timeout_time(ErtsPollSet ps)
+{
+    erts_atomic64_init_nob(&ps->timeout_time,
+			   (erts_aint64_t) ERTS_MONOTONIC_TIME_MAX);
+}
+
+static ERTS_INLINE void
+set_timeout_time(ErtsPollSet ps, ErtsMonotonicTime time)
+{
+    erts_atomic64_set_relb(&ps->timeout_time,
+			   (erts_aint64_t) time);
+}
+
+static ERTS_INLINE ErtsMonotonicTime
+get_timeout_time(ErtsPollSet ps)
+{
+    return (ErtsMonotonicTime) erts_atomic64_read_acqb(&ps->timeout_time);
+}
+
 #define ERTS_POLL_NOT_WOKEN	0
 #define ERTS_POLL_WOKEN		-1
 #define ERTS_POLL_WOKEN_INTR	1
@@ -1993,44 +2013,153 @@ save_poll_result(ErtsPollSet ps, ErtsPollResFd pr[], int max_res,
     }
 }
 
+static ERTS_INLINE ErtsMonotonicTime
+get_timeout(ErtsPollSet ps,
+	    int resolution,
+	    ErtsMonotonicTime timeout_time)
+{
+    ErtsMonotonicTime timeout, save_timeout_time;
+
+    if (timeout_time == ERTS_POLL_NO_TIMEOUT) {
+	save_timeout_time = ERTS_MONOTONIC_TIME_MIN;
+	timeout = 0;
+    }
+    else {
+	ErtsMonotonicTime diff_time, current_time;
+	current_time = erts_get_monotonic_time();
+	diff_time = timeout_time - current_time;
+	if (diff_time <= 0) {
+	    save_timeout_time = ERTS_MONOTONIC_TIME_MIN;
+	    timeout = 0;
+	}
+	else {
+	    save_timeout_time = current_time;
+	    switch (resolution) {
+	    case 1000:
+		/* Round up to nearest even milli second */
+		timeout = ERTS_MONOTONIC_TO_MSEC(diff_time - 1) + 1;
+		if (timeout > (ErtsMonotonicTime) INT_MAX)
+		    timeout = (ErtsMonotonicTime) INT_MAX;
+		save_timeout_time += ERTS_MSEC_TO_MONOTONIC(timeout);
+		break;
+	    case 1000000:
+		/* Round up to nearest even micro second */
+		timeout = ERTS_MONOTONIC_TO_USEC(diff_time - 1) + 1;
+		save_timeout_time += ERTS_USEC_TO_MONOTONIC(timeout);
+		break;
+	    case 1000000000:
+		/* Round up to nearest even nano second */
+		timeout = ERTS_MONOTONIC_TO_NSEC(diff_time - 1) + 1;
+		save_timeout_time += ERTS_NSEC_TO_MONOTONIC(timeout);
+		break;
+	    default:
+		ERTS_INTERNAL_ERROR("Invalid resolution");
+		timeout = 0;
+		save_timeout_time = 0;
+		break;
+	    }
+	}
+    }
+    set_timeout_time(ps, save_timeout_time);
+    return timeout;
+}
+
+#if ERTS_POLL_USE_SELECT
+
 static ERTS_INLINE int
-check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res)
+get_timeout_timeval(ErtsPollSet ps,
+		    SysTimeval *tvp,
+		    ErtsMonotonicTime timeout_time)
+{
+    ErtsMonotonicTime timeout = get_timeout(ps,
+					    1000*1000,
+					    timeout_time);
+
+    if (!timeout) {
+	tvp->tv_sec = 0;
+	tvp->tv_usec = 0;
+
+	return 0;
+    }
+    else {
+	ErtsMonotonicTime sec = timeout/(1000*1000);
+	tvp->tv_sec = sec;
+	tvp->tv_usec = timeout - sec*(1000*1000);
+
+	ASSERT(tvp->tv_sec >= 0);
+	ASSERT(tvp->tv_usec >= 0);
+	ASSERT(tvp->tv_usec < 1000*1000);
+
+	return !0;
+    }
+
+}
+
+#endif
+
+#if ERTS_POLL_USE_KQUEUE
+
+static ERTS_INLINE int
+get_timeout_timespec(ErtsPollSet ps,
+		     struct timespec *tsp,
+		     ErtsMonotonicTime timeout_time)
+{
+    ErtsMonotonicTime timeout = get_timeout(ps,
+					    1000*1000*1000,
+					    timeout_time);
+
+    if (!timeout) {
+	tsp->tv_sec = 0;
+	tsp->tv_nsec = 0;
+	return 0;
+    }
+    else {
+	ErtsMonotonicTime sec = timeout/(1000*1000*1000);
+	tsp->tv_sec = sec;
+	tsp->tv_nsec = timeout - sec*(1000*1000*1000);
+
+	ASSERT(tsp->tv_sec >= 0);
+	ASSERT(tsp->tv_nsec >= 0);
+	ASSERT(tsp->tv_nsec < 1000*1000);
+
+	return !0;
+    }
+}
+
+#endif
+
+static ERTS_INLINE int
+check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
 {
     int res;
     if (erts_smp_atomic_read_nob(&ps->no_of_user_fds) == 0
-	&& tv->tv_usec == 0 && tv->tv_sec == 0) {
+	&& timeout_time == ERTS_POLL_NO_TIMEOUT) {
 	/* Nothing to poll and zero timeout; done... */
 	return 0;
     }
     else {
-	long timeout = tv->tv_sec*1000 + tv->tv_usec/1000;
-	if (timeout > ERTS_AINT32_T_MAX)
-	    timeout = ERTS_AINT32_T_MAX;
-	ASSERT(timeout >= 0);
-	erts_smp_atomic32_set_relb(&ps->timeout, (erts_aint32_t) timeout);
+	int timeout;
 #if ERTS_POLL_USE_FALLBACK
 	if (!(ps->fallback_used = ERTS_POLL_NEED_FALLBACK(ps))) {
 
 #if ERTS_POLL_USE_EPOLL		/* --- epoll ------------------------------- */
-	    if (timeout > INT_MAX)
-		timeout = INT_MAX;
 	    if (max_res > ps->res_events_len)
 		grow_res_events(ps, max_res);
+	    timeout = (int) get_timeout(ps, 1000, timeout_time);
 #ifdef ERTS_SMP
 	    if (timeout)
 		erts_thr_progress_prepare_wait(NULL);
 #endif
-	    res = epoll_wait(ps->kp_fd, ps->res_events, max_res, (int)timeout);
+	    res = epoll_wait(ps->kp_fd, ps->res_events, max_res, timeout);
 #elif ERTS_POLL_USE_KQUEUE	/* --- kqueue ------------------------------ */
 	    struct timespec ts;
 	    if (max_res > ps->res_events_len)
 		grow_res_events(ps, max_res);
+	    timeout = get_timeout_timespec(ps, &ts, timeout_time);
 #ifdef ERTS_SMP
 	    if (timeout)
 		erts_thr_progress_prepare_wait(NULL);
 #endif
-	    ts.tv_sec = tv->tv_sec;
-	    ts.tv_nsec = tv->tv_usec*1000;
 	    res = kevent(ps->kp_fd, NULL, 0, ps->res_events, max_res, &ts);
 #endif				/* ----------------------------------------- */
 	}
@@ -2049,8 +2178,7 @@ check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res)
 #if ERTS_POLL_USE_WAKEUP_PIPE
 	    nfds++; /* Wakeup pipe */
 #endif
-	    if (timeout > INT_MAX)
-		timeout = INT_MAX;
+	    timeout = (int) get_timeout(ps, 1000, timeout_time);
 	    poll_res.dp_nfds = nfds < max_res ? nfds : max_res;
 	    if (poll_res.dp_nfds > ps->res_events_len)
 		grow_res_events(ps, poll_res.dp_nfds);
@@ -2059,33 +2187,33 @@ check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res)
 	    if (timeout)
 		erts_thr_progress_prepare_wait(NULL);
 #endif
-	    poll_res.dp_timeout = (int) timeout;
+	    poll_res.dp_timeout = timeout;
 	    res = ioctl(ps->kp_fd, DP_POLL, &poll_res);
 #elif ERTS_POLL_USE_POLL	/* --- poll -------------------------------- */
-	    if (timeout > INT_MAX)
-		timeout = INT_MAX;
+	    timeout = (int) get_timeout(ps, 1000, timeout_time);
 #ifdef ERTS_SMP
 	    if (timeout)
 		erts_thr_progress_prepare_wait(NULL);
 #endif
-	    res = poll(ps->poll_fds, ps->no_poll_fds, (int) timeout);
+	    res = poll(ps->poll_fds, ps->no_poll_fds, timeout);
 #elif ERTS_POLL_USE_SELECT	/* --- select ------------------------------ */
-	    SysTimeval to = *tv;
+	    SysTimeval to;
+	    timeout = get_timeout_timeval(ps, &to, timeout_time);
 
 	    ERTS_FD_COPY(&ps->input_fds, &ps->res_input_fds);
 	    ERTS_FD_COPY(&ps->output_fds, &ps->res_output_fds);
 	    
 #ifdef ERTS_SMP
-	    if (to.tv_sec || to.tv_usec)
+	    if (timeout)
 		erts_thr_progress_prepare_wait(NULL);
 #endif
 	    res = ERTS_SELECT(ps->max_fd + 1,
-			 &ps->res_input_fds,
-			 &ps->res_output_fds,
-			 NULL,
-			 &to);
+			      &ps->res_input_fds,
+			      &ps->res_output_fds,
+			      NULL,
+			      &to);
 #ifdef ERTS_SMP
-	    if (to.tv_sec || to.tv_usec)
+	    if (timeout)
 		erts_thr_progress_finalize_wait(NULL);
 	    if (res < 0
 		&& errno == EBADF
@@ -2108,10 +2236,10 @@ check_fd_events(ErtsPollSet ps, SysTimeval *tv, int max_res)
 		handle_update_requests(ps);
 		ERTS_POLLSET_UNLOCK(ps);
 		res = ERTS_SELECT(ps->max_fd + 1,
-			     &ps->res_input_fds,
-			     &ps->res_output_fds,
-			     NULL,
-			     &to);
+				  &ps->res_input_fds,
+				  &ps->res_output_fds,
+				  NULL,
+				  &to);
 		if (res == 0) {
 		    errno = EAGAIN;
 		    res = -1;
@@ -2133,15 +2261,14 @@ int
 ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet ps,
 				 ErtsPollResFd pr[],
 				 int *len,
-				 SysTimeval *utvp)
+				 ErtsMonotonicTime timeout_time)
 {
+    ErtsMonotonicTime to;
     int res, no_fds;
     int ebadf = 0;
 #ifdef ERTS_SMP
     int ps_locked = 0;
 #endif
-    SysTimeval *tvp;
-    SysTimeval itv;
 
     no_fds = *len;
 #ifdef ERTS_POLL_MAX_RES
@@ -2151,13 +2278,9 @@ ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet ps,
 
     *len = 0;
 
-    ASSERT(utvp);
-
-    tvp = utvp;
-
 #ifdef ERTS_POLL_DEBUG_PRINT
-    erts_printf("Entering erts_poll_wait(), timeout=%d\n",
-		 (int) tvp->tv_sec*1000 + tvp->tv_usec/1000);
+    erts_printf("Entering erts_poll_wait(), timeout_time=%bps\n",
+		timeout_time);
 #endif
 
     if (ERTS_POLLSET_SET_POLLED_CHK(ps)) {
@@ -2166,12 +2289,9 @@ ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet ps,
 	goto done;
     }
 
-    if (is_woken(ps)) {
-	/* Use zero timeout */
-	itv.tv_sec = 0;
-	itv.tv_usec = 0;
-	tvp = &itv;
-    }
+    to = (is_woken(ps)
+	  ? ERTS_POLL_NO_TIMEOUT /* Use zero timeout */
+	  : timeout_time);
 
 #if ERTS_POLL_USE_UPDATE_REQUESTS_QUEUE
     if (ERTS_POLLSET_HAVE_UPDATE_REQUESTS(ps)) {
@@ -2181,7 +2301,7 @@ ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet ps,
     }
 #endif
 
-    res = check_fd_events(ps, tvp, no_fds);
+    res = check_fd_events(ps, to, no_fds);
 
     woke_up(ps);
 
@@ -2224,7 +2344,7 @@ ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet ps,
 #endif
 
  done:
-    erts_smp_atomic32_set_relb(&ps->timeout, ERTS_AINT32_T_MAX);
+    set_timeout_time(ps, ERTS_MONOTONIC_TIME_MAX);
 #ifdef ERTS_POLL_DEBUG_PRINT
     erts_printf("Leaving %s = erts_poll_wait()\n",
 		 res == 0 ? "0" : erl_errno_id(res));
@@ -2268,13 +2388,14 @@ ERTS_POLL_EXPORT(erts_poll_async_sig_interrupt)(ErtsPollSet ps)
 void
 ERTS_POLL_EXPORT(erts_poll_interrupt_timed)(ErtsPollSet ps,
 					    int set,
-					    erts_short_time_t msec)
+					    ErtsMonotonicTime timeout_time)
 {
 #if ERTS_POLL_ASYNC_INTERRUPT_SUPPORT || defined(ERTS_SMP)
     if (!set)
 	reset_wakeup_state(ps);
     else {
-	if (erts_smp_atomic32_read_acqb(&ps->timeout) > (erts_aint32_t) msec)
+	ErtsMonotonicTime max_wait_time = get_timeout_time(ps);
+	if (max_wait_time > timeout_time)
 	    wake_poller(ps, 1, 0);
 #ifdef ERTS_POLL_COUNT_AVOIDED_WAKEUPS
 	else {
@@ -2431,7 +2552,7 @@ ERTS_POLL_EXPORT(erts_poll_create_pollset)(void)
 	ps->internal_fd_limit = kp_fd + 1;
     ps->kp_fd = kp_fd;
 #endif
-    erts_smp_atomic32_init_nob(&ps->timeout, ERTS_AINT32_T_MAX);
+    init_timeout_time(ps);
 #ifdef ERTS_POLL_COUNT_AVOIDED_WAKEUPS
     erts_smp_atomic_init_nob(&ps->no_avoided_wakeups, 0);
     erts_smp_atomic_init_nob(&ps->no_avoided_interrupts, 0);
diff --git a/erts/emulator/sys/common/erl_poll.h b/erts/emulator/sys/common/erl_poll.h
index 2f1c05f401..d02ed2396b 100644
--- a/erts/emulator/sys/common/erl_poll.h
+++ b/erts/emulator/sys/common/erl_poll.h
@@ -29,6 +29,8 @@
 
 #include "sys.h"
 
+#define ERTS_POLL_NO_TIMEOUT ERTS_MONOTONIC_TIME_MIN
+
 #if 0
 #define ERTS_POLL_COUNT_AVOIDED_WAKEUPS
 #endif
@@ -241,7 +243,7 @@ void		ERTS_POLL_EXPORT(erts_poll_interrupt)(ErtsPollSet,
 						      int);
 void		ERTS_POLL_EXPORT(erts_poll_interrupt_timed)(ErtsPollSet,
 							    int,
-							    erts_short_time_t);
+							    ErtsMonotonicTime);
 ErtsPollEvents	ERTS_POLL_EXPORT(erts_poll_control)(ErtsPollSet,
 						    ErtsSysFdType,
 						    ErtsPollEvents,
@@ -254,7 +256,7 @@ void		ERTS_POLL_EXPORT(erts_poll_controlv)(ErtsPollSet,
 int		ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet,
 						 ErtsPollResFd [],
 						 int *,
-						 SysTimeval *);
+						 ErtsMonotonicTime);
 int		ERTS_POLL_EXPORT(erts_poll_max_fds)(void);
 void		ERTS_POLL_EXPORT(erts_poll_info)(ErtsPollSet,
 						 ErtsPollInfo *);
diff --git a/erts/emulator/sys/ose/erl_poll.c b/erts/emulator/sys/ose/erl_poll.c
index 7d2a3d1e0b..36ee2557e8 100644
--- a/erts/emulator/sys/ose/erl_poll.c
+++ b/erts/emulator/sys/ose/erl_poll.c
@@ -114,7 +114,7 @@ struct ErtsPollSet_ {
     Uint item_count;
     PROCESS interrupt;
     erts_atomic32_t wakeup_state;
-    erts_smp_atomic32_t timeout;
+    erts_atomic64_t timeout_time;
 #ifdef ERTS_SMP
     erts_smp_mtx_t mtx;
 #endif
@@ -122,6 +122,26 @@ struct ErtsPollSet_ {
 
 static int max_fds = -1;
 
+static ERTS_INLINE void
+init_timeout_time(ErtsPollSet ps)
+{
+    erts_atomic64_init_nob(&ps->timeout_time,
+			   (erts_aint64_t) ERTS_MONOTONIC_TIME_MAX);
+}
+
+static ERTS_INLINE void
+set_timeout_time(ErtsPollSet ps, ErtsMonotonicTime time)
+{
+    erts_atomic64_set_relb(&ps->timeout_time,
+			   (erts_aint64_t) time);
+}
+
+static ERTS_INLINE ErtsMonotonicTime
+get_timeout_time(ErtsPollSet ps)
+{
+    return (ErtsMonotonicTime) erts_atomic64_read_acqb(&ps->timeout_time);
+}
+
 #define ERTS_POLL_NOT_WOKEN		((erts_aint32_t) (1 << 0))
 #define ERTS_POLL_WOKEN_INTR		((erts_aint32_t) (1 << 1))
 #define ERTS_POLL_WOKEN_TIMEDOUT	((erts_aint32_t) (1 << 2))
@@ -386,12 +406,14 @@ void erts_poll_interrupt(ErtsPollSet ps,int set) {
 
 }
 
-void erts_poll_interrupt_timed(ErtsPollSet ps,int set,erts_short_time_t msec) {
+void erts_poll_interrupt_timed(ErtsPollSet ps,
+			       int set,
+			       ErtsTimeoutTime timeout_time) {
     HARDTRACEF("erts_poll_interrupt_timed called!\n");
 
     if (!set)
 	reset_interrupt(ps);
-    else if (erts_smp_atomic32_read_acqb(&ps->timeout) > (erts_aint32_t) msec)
+    else if (get_timeout_time(ps) > timeout_time)
         set_interrupt(ps);
 }
 
@@ -453,12 +475,14 @@ done:
 }
 
 int erts_poll_wait(ErtsPollSet ps,
-	   ErtsPollResFd pr[],
-	   int *len,
-	   SysTimeval *utvp) {
+		   ErtsPollResFd pr[],
+		   int *len,
+		   ErtsMonotonicTime timeout_time)
+{
     int res = ETIMEDOUT, no_fds, currid = 0;
     OSTIME timeout;
     union SIGNAL *sig;
+    ErtsMonotonicTime current_time, diff_time, timeout;
     // HARDTRACEF("%ux: In erts_poll_wait",ps);
     if (ps->interrupt == (PROCESS)0)
       ps->interrupt = current_process();
@@ -472,16 +496,29 @@ int erts_poll_wait(ErtsPollSet ps,
 
     *len = 0;
 
-    ASSERT(utvp);
+    /* erts_printf("Entering erts_poll_wait(), timeout_time=%bps\n",
+		   timeout_time); */
 
-    /* erts_printf("Entering erts_poll_wait(), timeout=%d\n",
-		 (int) utvp->tv_sec*1000 + utvp->tv_usec/1000); */
-
-    timeout = utvp->tv_sec*1000 + utvp->tv_usec/1000;
+    if (timeout_time == ERTS_POLL_NO_TIMEOUT) {
+    no_timeout:
+	timeout = (OSTIME) 0;
+	save_timeout_time = ERTS_MONOTONIC_TIME_MIN;
+    }
+    else {
+	ErtsMonotonicTime current_time, diff_time;
+	current_time = erts_get_monotonic_time();
+	diff_time = timeout_time - current_time;
+	if (diff_time <= 0)
+	    goto no_timeout;
+	diff_time = (ERTS_MONOTONIC_TO_MSEC(diff_time - 1) + 1);
+	if (diff_time > INT_MAX)
+	    diff_time = INT_MAX;
+	timeout = (OSTIME) diff_time;
+	save_timeout_time = current_time;
+	save_timeout_time += ERTS_MSEC_TO_MONOTONIC(diff_time);
+    }
 
-    if (timeout > ((time_t) ERTS_AINT32_T_MAX))
-      timeout = ERTS_AINT32_T_MAX;
-    erts_smp_atomic32_set_relb(&ps->timeout, (erts_aint32_t) timeout);
+    set_timeout_time(ps, save_timeout_time);
 
     while (currid < no_fds) {
       if (timeout > 0) {
@@ -627,7 +664,7 @@ int erts_poll_wait(ErtsPollSet ps,
     }
 
     erts_atomic32_set_nob(&ps->wakeup_state, ERTS_POLL_NOT_WOKEN);
-    erts_smp_atomic32_set_nob(&ps->timeout, ERTS_AINT32_T_MAX);
+    set_timeout_time(ps, ERTS_MONOTONIC_TIME_MAX);
 
     *len = currid;
 
@@ -690,7 +727,7 @@ ErtsPollSet erts_poll_create_pollset(void)
     ps->info       = NULL;
     ps->interrupt  = (PROCESS)0;
     erts_atomic32_init_nob(&ps->wakeup_state, ERTS_POLL_NOT_WOKEN);
-    erts_smp_atomic32_init_nob(&ps->timeout, ERTS_AINT32_T_MAX);
+    init_timeout_time(ps);
 #ifdef ERTS_SMP
     erts_smp_mtx_init(&ps->mtx, "pollset");
 #endif
diff --git a/erts/emulator/sys/ose/sys.c b/erts/emulator/sys/ose/sys.c
index 5b950a7dae..13a5b71496 100644
--- a/erts/emulator/sys/ose/sys.c
+++ b/erts/emulator/sys/ose/sys.c
@@ -298,9 +298,9 @@ erts_sys_schedule_interrupt(int set)
 
 #ifdef ERTS_SMP
 void
-erts_sys_schedule_interrupt_timed(int set, erts_short_time_t msec)
+erts_sys_schedule_interrupt_timed(int set, ErtsMonotonicTime timeout_time)
 {
-    ERTS_CHK_IO_INTR_TMD(set, msec);
+    ERTS_CHK_IO_INTR_TMD(set, timeout_time);
 }
 #endif
 
diff --git a/erts/emulator/sys/unix/erl_unix_sys.h b/erts/emulator/sys/unix/erl_unix_sys.h
index f0050db114..46d0b8dc9b 100644
--- a/erts/emulator/sys/unix/erl_unix_sys.h
+++ b/erts/emulator/sys/unix/erl_unix_sys.h
@@ -114,11 +114,6 @@
 /*
  * Make sure that MAXPATHLEN is defined.
  */
-#ifdef GETHRTIME_WITH_CLOCK_GETTIME
-#undef HAVE_GETHRTIME
-#define HAVE_GETHRTIME 1
-#endif
-
 #ifndef MAXPATHLEN
 #   ifdef PATH_MAX
 #       define MAXPATHLEN PATH_MAX
@@ -160,33 +155,112 @@ typedef struct timeval SysTimeval;
 
 typedef struct tms SysTimes;
 
-extern int erts_ticks_per_sec;
-
-#define SYS_CLK_TCK (erts_ticks_per_sec)
+#define SYS_CLK_TCK (erts_sys_time_data__.r.o.ticks_per_sec)
 
 #define sys_times(Arg) times(Arg)
 
-#define ERTS_WRAP_SYS_TIMES 1
-extern int erts_ticks_per_sec_wrap;
-#define SYS_CLK_TCK_WRAP (erts_ticks_per_sec_wrap)
-extern clock_t sys_times_wrap(void);
+#if SIZEOF_LONG == 8
+typedef long ErtsMonotonicTime;
+#elif SIZEOF_LONG_LONG == 8
+typedef long long ErtsMonotonicTime;
+#else
+#error No signed 64-bit type found...
+#endif
+
+#define ERTS_MONOTONIC_TIME_MIN (((ErtsMonotonicTime) 1) << 63)
+#define ERTS_MONOTONIC_TIME_MAX (~ERTS_MONOTONIC_TIME_MIN)
+
+/*
+ * OS monotonic time
+ */
+
+/*
+ * Most common with os monotonic time using nano second
+ * time unit. These defines are modified below if this
+ * isn't the case...
+ */
+#define ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT 1
+#define ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT (1000*1000*1000)
+
+#undef ERTS_OS_MONOTONIC_INLINE_FUNC_PTR_CALL__
+#undef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+
+#if defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)
+
+#if defined(__linux__)
 
-#ifdef HAVE_GETHRTIME
-#ifdef GETHRTIME_WITH_CLOCK_GETTIME
-typedef long long SysHrTime;
+#define ERTS_HAVE_CORRECTED_OS_MONOTONIC 1
+#define ERTS_OS_MONOTONIC_INLINE_FUNC_PTR_CALL__ 1
 
-extern SysHrTime sys_gethrtime(void);
-#define sys_init_hrtime() /* Nothing */
+#else /* !defined(__linux__) */
 
-#else /* Real gethrtime (Solaris) */
+ErtsMonotonicTime erts_os_monotonic_time(void);
 
-typedef hrtime_t SysHrTime;
+#endif /* !defined(__linux__) */
+
+#elif defined(OS_MONOTONIC_TIME_USING_GETHRTIME)
+
+#define erts_os_monotonic() ((ErtsMonotonicTime) gethrtime())
+
+#elif defined(OS_MONOTONIC_TIME_USING_MACH_CLOCK_GET_TIME) \
+    || defined(OS_MONOTONIC_TIME_USING_TIMES)
+
+#if defined(OS_MONOTONIC_TIME_USING_TIMES)
+#  undef ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+#  define ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT (1000*1000)
+#  define ERTS_HAVE_ERTS_OS_TIME_OFFSET_FINALIZE 1
+void erts_os_time_offset_finalize(void);
+#  define ERTS_HAVE_ERTS_OS_MONOTONIC_TIME_INIT
+void erts_os_monotonic_time_init(void);
+#endif
 
-#define sys_gethrtime() gethrtime()
-#define sys_init_hrtime() /* Nothing */
+ErtsMonotonicTime erts_os_monotonic_time(void);
 
-#endif /* GETHRTIME_WITH_CLOCK_GETTIME */
-#endif /* HAVE_GETHRTIME */
+#else /* No OS monotonic available... */
+
+#undef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+#undef ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+#define ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT (1000*1000)
+
+#endif
+
+struct erts_sys_time_read_only_data__ {
+#ifdef ERTS_OS_MONOTONIC_INLINE_FUNC_PTR_CALL__
+    ErtsMonotonicTime (*os_monotonic_time)(void);
+#endif
+    int ticks_per_sec;
+};
+
+typedef struct {
+    union {
+	struct erts_sys_time_read_only_data__ o;
+	char align__[(((sizeof(struct erts_sys_time_read_only_data__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } r;
+} ErtsSysTimeData__;
+
+extern ErtsSysTimeData__ erts_sys_time_data__;
+
+#ifdef ERTS_OS_MONOTONIC_INLINE_FUNC_PTR_CALL__
+
+ERTS_GLB_INLINE ErtsMonotonicTime erts_os_monotonic_time(void);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE ErtsMonotonicTime
+erts_os_monotonic_time(void)
+{
+    return (*erts_sys_time_data__.r.o.os_monotonic_time)();
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#endif /* ERTS_OS_MONOTONIC_INLINE_FUNC_PTR_CALL__ */
+
+/*
+ *
+ */
 
 #if (defined(HAVE_GETHRVTIME) || defined(HAVE_CLOCK_GETTIME_CPU_TIME))
 typedef long long SysCpuTime;
diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c
index 0d9c743c0c..2eb0ffa905 100644
--- a/erts/emulator/sys/unix/sys.c
+++ b/erts/emulator/sys/unix/sys.c
@@ -308,7 +308,7 @@ struct {
     int (*event)(ErlDrvPort, ErlDrvEvent, ErlDrvEventData);
     void (*check_io_as_interrupt)(void);
     void (*check_io_interrupt)(int);
-    void (*check_io_interrupt_tmd)(int, erts_short_time_t);
+    void (*check_io_interrupt_tmd)(int, ErtsMonotonicTime);
     void (*check_io)(int);
     Uint (*size)(void);
     Eterm (*info)(void *);
@@ -414,9 +414,9 @@ erts_sys_schedule_interrupt(int set)
 
 #ifdef ERTS_SMP
 void
-erts_sys_schedule_interrupt_timed(int set, erts_short_time_t msec)
+erts_sys_schedule_interrupt_timed(int set, ErtsMonotonicTime timeout_time)
 {
-    ERTS_CHK_IO_INTR_TMD(set, msec);
+    ERTS_CHK_IO_INTR_TMD(set, timeout_time);
 }
 #endif
 
@@ -1003,25 +1003,6 @@ static void unblock_signals(void)
 
 }
 
-/************************** Time stuff **************************/
-#ifdef HAVE_GETHRTIME
-#ifdef GETHRTIME_WITH_CLOCK_GETTIME
-
-SysHrTime sys_gethrtime(void)
-{
-    struct timespec ts;
-    long long result;
-    if (clock_gettime(CLOCK_MONOTONIC,&ts) != 0) {
-	erl_exit(1,"Fatal, could not get clock_monotonic value!, "
-		 "errno = %d\n", errno);
-    }
-    result = ((long long) ts.tv_sec) * 1000000000LL + 
-	((long long) ts.tv_nsec);
-    return (SysHrTime) result;
-}
-#endif
-#endif
-
 /************************** OS info *******************************/
 
 /* Used by erlang:info/1. */
diff --git a/erts/emulator/sys/unix/sys_time.c b/erts/emulator/sys/unix/sys_time.c
index fcce54a2c4..9fdb1930b7 100644
--- a/erts/emulator/sys/unix/sys_time.c
+++ b/erts/emulator/sys/unix/sys_time.c
@@ -53,9 +53,40 @@
 
 /******************* Routines for time measurement *********************/
 
-int erts_ticks_per_sec = 0; /* Will be SYS_CLK_TCK in erl_unix_sys.h */
-int erts_ticks_per_sec_wrap = 0; /* Will be SYS_CLK_TCK_WRAP */
-static int ticks_bsr = 0; /* Shift wrapped tick value this much to the right */
+#undef ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__
+#undef ERTS_SYS_TIME_INTERNAL_STATE_READ_ONLY__
+
+#if defined(OS_MONOTONIC_TIME_USING_TIMES)
+
+#define ERTS_WRAP_SYS_TIMES 1
+#define ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__
+#define ERTS_SYS_TIME_INTERNAL_STATE_READ_ONLY__
+
+/*
+ * Not sure there is a need to use times() anymore, perhaps drop
+ * support for this soon...
+ *
+ * sys_times() might need to be wrapped and the values shifted (right)
+ * a bit to cope with faster ticks, this has to be taken care 
+ * of dynamically to start with, a special version that uses
+ * the times() return value as a high resolution timer can be made
+ * to fully utilize the faster ticks, like on windows, but for now, we'll
+ * settle with this silly workaround
+ */
+#ifdef ERTS_WRAP_SYS_TIMES
+static clock_t sys_times_wrap(void);
+#define KERNEL_TICKS() (sys_times_wrap() &  \
+			((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) 
+#define ERTS_KERNEL_TICK_TO_USEC(TCKS) (((TCKS)*(1000*1000)) \
+					/ internal_state.r.o.ticks_per_sec_wrap)
+#else
+
+#define KERNEL_TICKS() (sys_times(&internal_state.w.f.dummy_tms) &  \
+			((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) 
+#define ERTS_KERNEL_TICK_TO_USEC(TCKS) (((TCKS)*(1000*1000))/SYS_CLK_TCK)
+#endif
+
+#endif
 
 /* 
  * init timers, chose a tick length, and return it.
@@ -63,37 +94,374 @@ static int ticks_bsr = 0; /* Shift wrapped tick value this much to the right */
  * does almost everything. Other platforms have to
  * emulate Unix in this sense.
  */
-int sys_init_time(void)
+
+ErtsSysTimeData__ erts_sys_time_data__ erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+#if defined(__linux__) && defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)
+
+#define ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__
+
+ErtsMonotonicTime clock_gettime_monotonic_raw(void);
+ErtsMonotonicTime clock_gettime_monotonic_verified(void);
+
+#endif /* defined(__linux__) && defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME) */
+
+#ifdef ERTS_SYS_TIME_INTERNAL_STATE_READ_ONLY__
+struct sys_time_internal_state_read_only__ {
+#if defined(OS_MONOTONIC_TIME_USING_TIMES)
+    int ticks_bsr;
+    int ticks_per_sec_wrap;
+#endif
+};
+#endif
+
+#ifdef ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__
+struct sys_time_internal_state_write_freq__ {
+    erts_smp_mtx_t mtx;
+#if defined(__linux__) && defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)
+    ErtsMonotonicTime last_delivered;
+#endif
+#if defined(OS_MONOTONIC_TIME_USING_TIMES)
+    ErtsMonotonicTime last_tick_count;
+    ErtsMonotonicTime last_tick_wrap_count;
+    ErtsMonotonicTime last_tick_monotonic_time;
+    ErtsMonotonicTime last_timeofday_usec;
+#ifndef ERTS_WRAP_SYS_TIMES 
+    SysTimes dummy_tms;
+#endif
+#endif
+};
+#endif
+
+#if defined(ERTS_SYS_TIME_INTERNAL_STATE_READ_ONLY__)	\
+    || defined(ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__)
+static struct {
+#ifdef ERTS_SYS_TIME_INTERNAL_STATE_READ_ONLY__
+    union {
+	struct sys_time_internal_state_read_only__ o;
+	char align__[(((sizeof(struct sys_time_internal_state_read_only__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } r;
+#endif
+#ifdef ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__
+    union {
+	struct sys_time_internal_state_write_freq__ f;
+	char align__[(((sizeof(struct sys_time_internal_state_write_freq__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } w;
+#endif
+} internal_state erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+#endif
+
+void
+sys_init_time(ErtsSysInitTimeResult *init_resp)
 {
+#if !defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT)
+
+    init_resp->have_os_monotonic = 0;
+
+#else /* defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT) */
+
+    int major, minor, build, vsn;
+
+    init_resp->os_monotonic_info.resolution = (Uint64) 1000*1000*1000;
+#if defined(HAVE_CLOCK_GETRES) && defined(MONOTONIC_CLOCK_ID)
+    {
+	struct timespec ts;
+	if (clock_getres(MONOTONIC_CLOCK_ID, &ts) == 0
+	    && ts.tv_sec == 0 && ts.tv_nsec != 0) {
+	    init_resp->os_monotonic_info.resolution /= ts.tv_nsec;
+	}
+    }
+#endif
+
+#ifdef MONOTONIC_CLOCK_ID_STR
+    init_resp->os_monotonic_info.clock_id = MONOTONIC_CLOCK_ID_STR;
+#else
+    init_resp->os_monotonic_info.clock_id = NULL;
+#endif
+
+    init_resp->os_monotonic_info.locked_use = 0;
+
+#if defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)
+    init_resp->os_monotonic_info.func = "clock_gettime";
+#elif defined(OS_MONOTONIC_TIME_USING_MACH_CLOCK_GET_TIME)
+    init_resp->os_monotonic_info.func = "clock_get_time";
+#elif defined(OS_MONOTONIC_TIME_USING_GETHRTIME)
+    init_resp->os_monotonic_info.func = "gethrtime";
+#elif defined(OS_MONOTONIC_TIME_USING_TIMES)
+    init_resp->os_monotonic_info.func = "times";
+    init_resp->os_monotonic_info.locked_use = 1;
+    init_resp->os_monotonic_info.resolution = TICKS_PER_SEC();
+#else
+# error Unknown erts_os_monotonic_time() implementation
+#endif
+
+    init_resp->have_os_monotonic = 1;
+
+    os_version(&major, &minor, &build);
+
+    vsn = ERTS_MK_VSN_INT(major, minor, build);
+
+
+#if defined(__linux__) && defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)
+    if (vsn >= ERTS_MK_VSN_INT(2, 6, 33))
+	erts_sys_time_data__.r.o.os_monotonic_time =
+	    clock_gettime_monotonic_raw;
+    else {
+	/*
+	 * Linux versions prior to 2.6.33 have a
+	 * known bug that sometimes cause monotonic
+	 * time to take small steps backwards.
+	 */
+	erts_sys_time_data__.r.o.os_monotonic_time =
+	    clock_gettime_monotonic_verified;
+	erts_smp_mtx_init(&internal_state.w.f.mtx,
+			  "os_monotonic_time");
+	internal_state.w.f.last_delivered
+	    = clock_gettime_monotonic_raw();
+	init_resp->os_monotonic_info.locked_use = 1;
+    }
+#else /* !(defined(__linux__) && defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)) */
+    {
+	char flavor[1024];
+
+	os_flavor(flavor, sizeof(flavor));
+
+	if (sys_strcmp(flavor, "sunos") == 0) {
+	    /*
+	     * Don't trust hrtime on multi processors
+	     * on SunOS prior to SunOS 5.8
+	     */
+	    if (vsn < ERTS_MK_VSN_INT(5, 8, 0)) {
+#if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF)
+		if (sysconf(_SC_NPROCESSORS_CONF) > 1)
+#endif
+		    init_resp->have_os_monotonic = 0;
+	    }
+	}
+    }
+#endif /* !(defined(__linux__) && defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)) */
+
+#endif /* defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT) */
+
+    init_resp->os_monotonic_time_unit = ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT;
+    init_resp->sys_clock_resolution = SYS_CLOCK_RESOLUTION;
+
     /* 
-     * This (erts_ticks_per_sec) is only for times() (CLK_TCK), 
-     * the resolution is always one millisecond..
+     * This (erts_sys_time_data__.r.o.ticks_per_sec) is only for
+     * times() (CLK_TCK), the resolution is always one millisecond..
      */
-    if ((erts_ticks_per_sec = TICKS_PER_SEC()) < 0)
-	erl_exit(1, "Can't get clock ticks/sec\n");
-    if (erts_ticks_per_sec >= 1000) {
+    if ((erts_sys_time_data__.r.o.ticks_per_sec = TICKS_PER_SEC()) < 0)
+	erl_exit(ERTS_ABORT_EXIT, "Can't get clock ticks/sec\n");
+    
+#if defined(OS_MONOTONIC_TIME_USING_TIMES)
+
+    if (erts_sys_time_data__.r.o.ticks_per_sec >= 1000) {
 	/* Workaround for beta linux kernels, need to be done in runtime
 	   to make erlang run on both 2.4 and 2.5 kernels. In the future, 
 	   the kernel ticks might as 
 	   well be used as a high res timer instead, but that's for when the 
 	   majority uses kernels with HZ == 1024 */
-	ticks_bsr = 3;
+	internal_state.r.o.ticks_bsr = 3;
     } else {
-	ticks_bsr = 0;
+	internal_state.r.o.ticks_bsr = 0;
     }
-    erts_ticks_per_sec_wrap = (erts_ticks_per_sec >> ticks_bsr);
-    return SYS_CLOCK_RESOLUTION;
+
+    internal_state.r.o.ticks_per_sec_wrap
+	= (erts_sys_time_data__.r.o.ticks_per_sec
+	   >> internal_state.r.o.ticks_bsr);
+
+    erts_smp_mtx_init(&internal_state.w.f.mtx, "os_monotonic_time");
+    internal_state.w.f.last_tick_count = KERNEL_TICKS();
+    internal_state.w.f.last_tick_wrap_count = 0;    
+    internal_state.w.f.last_tick_monotonic_time
+	= ERTS_KERNEL_TICK_TO_USEC(internal_state.w.f.last_tick_count);
+    {
+	SysTimeval tv;
+	sys_gettimeofday(&tv);
+	internal_state.w.f.last_timeofday_usec = tv.tv_sec*(1000*1000);
+	internal_state.w.f.last_timeofday_usec += tv.tv_usec;
+    }
+
+#endif /* defined(OS_MONOTONIC_TIME_USING_TIMES) */
+
+}
+
+#if defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)
+
+static ERTS_INLINE ErtsMonotonicTime
+clock_gettime_monotonic(void)
+{
+    ErtsMonotonicTime mtime;
+    struct timespec ts;
+
+    if (clock_gettime(MONOTONIC_CLOCK_ID,&ts) != 0) {
+	int err = errno;
+	char *errstr = err ? strerror(err) : "unknown";
+	erl_exit(ERTS_ABORT_EXIT,
+		 "clock_gettime(%s, _) failed: %s (%d)\n",
+		 MONOTONIC_CLOCK_ID_STR, errstr, err);
+
+    }
+    mtime = (ErtsMonotonicTime) ts.tv_sec;
+    mtime *= (ErtsMonotonicTime) 1000*1000*1000;
+    mtime += (ErtsMonotonicTime) ts.tv_nsec;
+    return mtime;
+}
+
+#if defined(__linux__)
+
+ErtsMonotonicTime clock_gettime_monotonic_verified(void)
+{
+    ErtsMonotonicTime mtime;
+
+    mtime = clock_gettime_monotonic();
+
+    erts_smp_mtx_lock(&internal_state.w.f.mtx);
+    if (mtime < internal_state.w.f.last_delivered)
+	mtime = internal_state.w.f.last_delivered;
+    else
+	internal_state.w.f.last_delivered = mtime;
+    erts_smp_mtx_unlock(&internal_state.w.f.mtx);
+
+    return mtime;
+}
+
+ErtsMonotonicTime clock_gettime_monotonic_raw(void)
+{
+    return clock_gettime_monotonic();
 }
 
-clock_t sys_times_wrap(void)
+#else /* !defined(__linux__) */
+
+ErtsMonotonicTime erts_os_monotonic_time(void)
+{
+    return clock_gettime_monotonic();
+}
+
+#endif /* !defined(__linux__) */
+
+#elif defined(OS_MONOTONIC_TIME_USING_MACH_CLOCK_GET_TIME)
+
+#include <mach/clock.h>
+#include <mach/mach.h>
+
+ErtsMonotonicTime erts_os_monotonic_time(void)
+{
+    ErtsMonotonicTime mtime;
+    kern_return_t res;
+    clock_serv_t clk_srv;
+    mach_timespec_t time_spec;
+    int err;
+
+    host_get_clock_service(mach_host_self(),
+			   MONOTONIC_CLOCK_ID,
+			   &clk_srv);
+    errno = 0;
+    res = clock_get_time(clk_srv, &time_spec);
+    err = errno;
+    mach_port_deallocate(mach_task_self(), clk_srv);
+    if (res != KERN_SUCCESS) {
+	char *errstr = err ? strerror(err) : "unknown";
+	erl_exit(ERTS_ABORT_EXIT,
+		 "clock_get_time(%s, _) failed: %s (%d)\n",
+		 MONOTONIC_CLOCK_ID_STR, errstr, err);
+    }
+
+    mtime = (ErtsMonotonicTime) time_spec.tv_sec;
+    mtime *= (ErtsMonotonicTime) 1000*1000*1000;
+    mtime += (ErtsMonotonicTime) time_spec.tv_nsec;
+    return mtime;
+}
+
+#elif defined(OS_MONOTONIC_TIME_USING_TIMES)
+
+static clock_t sys_times_wrap(void)
 {
     SysTimes dummy;
-    clock_t result = (sys_times(&dummy) >> ticks_bsr);
+    clock_t result = (sys_times(&dummy) >> internal_state.r.o.ticks_bsr);
     return result;
 }
 
+void
+erts_os_time_offset_finalize(void)
+{
+    erts_smp_mtx_lock(&internal_state.w.f.mtx);
+    internal_state.w.f.last_tick_wrap_count = 0;
+    erts_smp_mtx_unlock(&internal_state.w.f.mtx);
+}
+
+#define ERTS_TIME_EXCEED_TICK_LIMIT(SYS_TIME, TCK_TIME)			\
+    (((Uint64) (SYS_TIME)) - (((Uint64) (TCK_TIME))			\
+			      - ERTS_KERNEL_TICK_TO_USEC(1))		\
+     > ERTS_KERNEL_TICK_TO_USEC(2))
+
+/* Returns monotonic time in micro seconds */
+ErtsMonotonicTime
+erts_os_monotonic_time(void)
+{
+    SysTimeval tv;
+    ErtsMonotonicTime res;
+    ErtsMonotonicTime tick_count;
+    ErtsMonotonicTime tick_count_usec;
+    ErtsMonotonicTime tick_monotonic_time;
+    ErtsMonotonicTime timeofday_usec;
+    ErtsMonotonicTime timeofday_diff_usec;
+
+    erts_smp_mtx_lock(&internal_state.w.f.mtx);
 
+    tick_count = (ErtsMonotonicTime) KERNEL_TICKS();
+    sys_gettimeofday(&tv);
+
+    if (internal_state.w.f.last_tick_count > tick_count) {
+	internal_state.w.f.last_tick_wrap_count
+	    += (((ErtsMonotonicTime) 1) << ((sizeof(clock_t) * 8) - 1));
+    }
+    internal_state.w.f.last_tick_count = tick_count;
+    tick_count += internal_state.w.f.last_tick_wrap_count;
+
+    tick_count_usec = ERTS_KERNEL_TICK_TO_USEC(tick_count);
+
+    timeofday_usec = (ErtsMonotonicTime) tv.tv_sec*(1000*1000);
+    timeofday_usec += (ErtsMonotonicTime) tv.tv_usec;
+    timeofday_diff_usec = timeofday_usec;
+    timeofday_diff_usec -= internal_state.w.f.last_timeofday_usec;
+    internal_state.w.f.last_timeofday_usec = timeofday_usec;
+
+    if (timeofday_diff_usec < 0) {
+	/* timeofday jumped backwards use tick count only... */
+	tick_monotonic_time = tick_count_usec;
+    }
+    else {
+	/* Use time diff from of timeofday if not off by too much... */
+	tick_monotonic_time = internal_state.w.f.last_tick_monotonic_time;
+	tick_monotonic_time += timeofday_diff_usec;
+
+	if (ERTS_TIME_EXCEED_TICK_LIMIT(tick_monotonic_time, tick_count_usec)) {
+	    /*
+	     * Value off by more than one tick from tick_count, i.e.
+	     * timofday leaped one way or the other. We use
+	     * tick_count_usec as is instead and unfortunately
+	     * get lousy precision.
+	     */
+	    tick_monotonic_time = tick_count_usec;
+	}
+    }
+
+    if (internal_state.w.f.last_tick_monotonic_time < tick_monotonic_time)
+	internal_state.w.f.last_tick_monotonic_time = tick_monotonic_time;
+
+    res = internal_state.w.f.last_tick_monotonic_time;
+
+    erts_smp_mtx_unlock(&internal_state.w.f.mtx);
+
+    return res;
+}
 
+#endif  /* !defined(OS_MONOTONIC_TIME_USING_TIMES) */
 
 #ifdef HAVE_GETHRVTIME_PROCFS_IOCTL
 
diff --git a/erts/emulator/sys/win32/erl_poll.c b/erts/emulator/sys/win32/erl_poll.c
index 972170d465..5a62b00a68 100644
--- a/erts/emulator/sys/win32/erl_poll.c
+++ b/erts/emulator/sys/win32/erl_poll.c
@@ -285,7 +285,7 @@ struct ErtsPollSet_ {
 #ifdef ERTS_SMP
     erts_smp_mtx_t mtx;
 #endif
-    erts_smp_atomic32_t timeout;
+    erts_atomic64_t timeout_time;
 };
 
 #ifdef ERTS_SMP
@@ -363,6 +363,26 @@ do { \
     wait_standby(PS); \
  } while(0)
 
+static ERTS_INLINE void
+init_timeout_time(ErtsPollSet ps)
+{
+    erts_atomic64_init_nob(&ps->timeout_time,
+			   (erts_aint64_t) ERTS_MONOTONIC_TIME_MAX);
+}
+
+static ERTS_INLINE void
+set_timeout_time(ErtsPollSet ps, ErtsMonotonicTime time)
+{
+    erts_atomic64_set_relb(&ps->timeout_time,
+			   (erts_aint64_t) time);
+}
+
+static ERTS_INLINE ErtsMonotonicTime
+get_timeout_time(ErtsPollSet ps)
+{
+    return (ErtsMonotonicTime) erts_atomic64_read_acqb(&ps->timeout_time);
+}
+
 #define ERTS_POLL_NOT_WOKEN		((erts_aint32_t) 0)
 #define ERTS_POLL_WOKEN_IO_READY	((erts_aint32_t) 1)
 #define ERTS_POLL_WOKEN_INTR		((erts_aint32_t) 2)
@@ -422,15 +442,29 @@ wakeup_cause(ErtsPollSet ps)
 }
 
 static ERTS_INLINE DWORD
-poll_wait_timeout(ErtsPollSet ps, SysTimeval *tvp)
+poll_wait_timeout(ErtsPollSet ps, ErtsMonotonicTime timeout_time)
 {
-    time_t timeout = tvp->tv_sec * 1000 + tvp->tv_usec / 1000;
+    ErtsMonotonicTime current_time, diff_time, timeout;
 
-    if (timeout <= 0) {
+    if (timeout_time == ERTS_POLL_NO_TIMEOUT) {
+    no_timeout:
+	set_timeout_time(ps, ERTS_MONOTONIC_TIME_MIN);
 	woke_up(ps);
 	return (DWORD) 0;
     }
 
+    current_time = erts_get_monotonic_time();
+    diff_time = timeout_time - current_time;
+    if (diff_time <= 0)
+	goto no_timeout;
+
+    /* Round up to nearest milli second */
+    timeout = (ERTS_MONOTONIC_TO_MSEC(diff_time - 1) + 1);
+    if (timeout > INT_MAX)
+	timeout = INT_MAX; /* Also prevents DWORD overflow */
+
+    set_timeout_time(ps, current_time + ERTS_MSEC_TO_MONOTONIC(timeout));
+
     ResetEvent(ps->event_io_ready);
     /*
      * Since we don't know the internals of ResetEvent() we issue
@@ -442,10 +476,6 @@ poll_wait_timeout(ErtsPollSet ps, SysTimeval *tvp)
     if (erts_atomic32_read_nob(&ps->wakeup_state) != ERTS_POLL_NOT_WOKEN)
 	return (DWORD) 0;
 
-    if (timeout > ((time_t) ERTS_AINT32_T_MAX))
-	timeout = ERTS_AINT32_T_MAX; /* Also prevents DWORD overflow */
-
-    erts_smp_atomic32_set_relb(&ps->timeout, (erts_aint32_t) timeout);
     return (DWORD) timeout;
 }
 
@@ -1012,12 +1042,12 @@ void  erts_poll_interrupt(ErtsPollSet ps, int set /* bool */)
 
 void erts_poll_interrupt_timed(ErtsPollSet ps,
 			       int set /* bool */,
-			       erts_short_time_t msec)
+			       ErtsMonotonicTime timeout_time)
 {
-    HARDTRACEF(("In erts_poll_interrupt_timed(%d,%ld)",set,msec));
+    HARDTRACEF(("In erts_poll_interrupt_timed(%d,%ld)",set,timeout_time));
     if (!set)
 	reset_interrupt(ps);
-    else if (erts_smp_atomic32_read_acqb(&ps->timeout) > (erts_aint32_t) msec)
+    else if (get_timeout_time(ps) > timeout_time)
 	set_interrupt(ps);
     HARDTRACEF(("Out erts_poll_interrupt_timed"));
 }
@@ -1092,7 +1122,7 @@ void erts_poll_controlv(ErtsPollSet ps,
 int erts_poll_wait(ErtsPollSet ps,
 		   ErtsPollResFd pr[],
 		   int *len,
-		   SysTimeval *tvp)
+		   ErtsMonotonicTime timeout_time)
 {
     int no_fds;
     DWORD timeout;
@@ -1149,7 +1179,7 @@ int erts_poll_wait(ErtsPollSet ps,
 	no_fds = ERTS_POLL_MAX_RES;
 #endif
 
-    timeout = poll_wait_timeout(ps, tvp);
+    timeout = poll_wait_timeout(ps, timeout_time);
 
     /*HARDDEBUGF(("timeout = %ld",(long) timeout));*/
 
@@ -1242,7 +1272,7 @@ int erts_poll_wait(ErtsPollSet ps,
 	erts_mtx_unlock(&w->mtx);
     }
  done:
-    erts_smp_atomic32_set_nob(&ps->timeout, ERTS_AINT32_T_MAX);
+    set_timeout_time(ps, ERTS_MONOTONIC_TIME_MAX);
     *len = num;
     ERTS_POLLSET_UNLOCK(ps);
     HARDTRACEF(("Out erts_poll_wait"));
@@ -1326,7 +1356,7 @@ ErtsPollSet erts_poll_create_pollset(void)
 #ifdef ERTS_SMP
     erts_smp_mtx_init(&ps->mtx, "pollset");
 #endif
-    erts_smp_atomic32_init_nob(&ps->timeout, ERTS_AINT32_T_MAX);
+    init_timeout_time(ps);
 
     HARDTRACEF(("Out erts_poll_create_pollset"));
     return ps;
diff --git a/erts/emulator/sys/win32/erl_win_sys.h b/erts/emulator/sys/win32/erl_win_sys.h
index fde32c8684..33aa88ab5f 100644
--- a/erts/emulator/sys/win32/erl_win_sys.h
+++ b/erts/emulator/sys/win32/erl_win_sys.h
@@ -120,9 +120,6 @@
 /*
  * For erl_time_sup
  */
-#define HAVE_GETHRTIME
-
-#define sys_init_hrtime() /* Nothing */
 
 #define SYS_CLK_TCK 1000
 #define SYS_CLOCK_RESOLUTION 1
@@ -164,18 +161,58 @@ typedef struct {
 #if defined (__GNUC__)
 typedef unsigned long long Uint64;
 typedef long long          Sint64;
-
-typedef long long SysHrTime;
+#  ifdef ULLONG_MAX
+#    define ERTS_UINT64_MAX ULLONG_MAX
+#  endif
+#  ifdef LLONG_MAX
+#    define ERTS_SINT64_MAX LLONG_MAX
+#  endif
+#  ifdef LLONG_MIN
+#    define ERTS_SINT64_MIN LLONG_MIN
+#  endif
+
+typedef long long ErtsMonotonicTime;
 #else
 typedef ULONGLONG Uint64;
 typedef LONGLONG  Sint64;
 
-typedef LONGLONG SysHrTime;
+typedef LONGLONG ErtsMonotonicTime;
 #endif
 
-extern int sys_init_time(void);
+#define ERTS_MONOTONIC_TIME_MIN (((ErtsMonotonicTime) 1) << 63)
+#define ERTS_MONOTONIC_TIME_MAX (~ERTS_MONOTONIC_TIME_MIN)
+
+#define ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT 1
+#define ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT 0
+
+struct erts_sys_time_read_only_data__ {
+    ErtsMonotonicTime (*os_monotonic_time)(void);
+};
+
+typedef struct {
+    union {
+	struct erts_sys_time_read_only_data__ o;
+	char align__[(((sizeof(struct erts_sys_time_read_only_data__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } r;
+} ErtsSysTimeData__;
+
+extern ErtsSysTimeData__ erts_sys_time_data__;
+
+ERTS_GLB_INLINE ErtsMonotonicTime erts_os_monotonic_time(void);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE ErtsMonotonicTime
+erts_os_monotonic_time(void)
+{
+    return (*erts_sys_time_data__.r.o.os_monotonic_time)();
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
 extern void sys_gettimeofday(SysTimeval *tv);
-extern SysHrTime sys_gethrtime(void);
 extern clock_t sys_times(SysTimes *buffer);
 
 extern char *win_build_environment(char *);
diff --git a/erts/emulator/sys/win32/sys.c b/erts/emulator/sys/win32/sys.c
index 5d51659b4e..1ba87b8b0b 100644
--- a/erts/emulator/sys/win32/sys.c
+++ b/erts/emulator/sys/win32/sys.c
@@ -3273,9 +3273,9 @@ erts_sys_schedule_interrupt(int set)
 
 #ifdef ERTS_SMP
 void
-erts_sys_schedule_interrupt_timed(int set, erts_short_time_t msec)
+erts_sys_schedule_interrupt_timed(int set, ErtsMonotonicTime timeout_time)
 {
-    erts_check_io_interrupt_timed(set, msec);
+    erts_check_io_interrupt_timed(set, timeout_time);
 }
 #endif
 
diff --git a/erts/emulator/sys/win32/sys_time.c b/erts/emulator/sys/win32/sys_time.c
index b84c8f85ce..3a10125c81 100644
--- a/erts/emulator/sys/win32/sys_time.c
+++ b/erts/emulator/sys/win32/sys_time.c
@@ -61,11 +61,6 @@
 	(epoch) = ((ull.QuadPart / TICKS_PER_SECOND) - EPOCH_JULIAN_DIFF); \
     } while(0)
  
-static SysHrTime wrap = 0;
-static DWORD last_tick_count = 0;
-static erts_smp_mtx_t wrap_lock;
-static ULONGLONG (WINAPI *pGetTickCount64)(void) = NULL;
-
 /* Getting timezone information is a heavy operation, so we want to do this 
    only once */
 
@@ -76,17 +71,161 @@ static int days_in_month[2][13] = {
     {0,31,28,31,30,31,30,31,31,30,31,30,31},
     {0,31,29,31,30,31,30,31,31,30,31,30,31}};
 
-int 
-sys_init_time(void)
+/*
+ * erts_os_monotonic_time()
+ */
+
+struct sys_time_internal_state_read_only__ {
+    ULONGLONG (WINAPI *pGetTickCount64)(void);
+    BOOL (WINAPI *pQueryPerformanceCounter)(LARGE_INTEGER *);
+};
+
+struct sys_time_internal_state_write_freq__ {
+    erts_smp_mtx_t mtime_mtx;
+    ULONGLONG wrap;
+    ULONGLONG last_tick_count;
+};
+
+__declspec(align(ASSUMED_CACHE_LINE_SIZE)) struct {
+    union {
+	struct sys_time_internal_state_read_only__ o;
+	char align__[(((sizeof(struct sys_time_internal_state_read_only__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } r;
+    union {
+	struct sys_time_internal_state_write_freq__ f;
+	char align__[(((sizeof(struct sys_time_internal_state_write_freq__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } w;
+} internal_state;
+
+__declspec(align(ASSUMED_CACHE_LINE_SIZE)) ErtsSysTimeData__ erts_sys_time_data__;
+
+static ErtsMonotonicTime
+os_monotonic_time_qpc(void)
 {
+    LARGE_INTEGER pc;
+
+    if (!(*internal_state.r.o.pQueryPerformanceCounter)(&pc))
+	erl_exit(ERTS_ABORT_EXIT, "QueryPerformanceCounter() failed\n");
+
+    return (ErtsMonotonicTime) pc.QuadPart;
+}
+
+static ErtsMonotonicTime
+os_monotonic_time_gtc32(void) 
+{
+    ULONGLONG res, ticks;
+
+    erts_smp_mtx_lock(&internal_state.w.f.mtime_mtx);
+
+    ticks = (ULONGLONG) (GetTickCount() & 0x7FFFFFFF);
+    if (ticks < internal_state.w.f.last_tick_count)
+	internal_state.w.f.wrap += (ULONGLONG) LL_LITERAL(1) << 31;
+    internal_state.w.f.last_tick_count = ticks;
+    res = ticks + internal_state.w.f.wrap;
+
+    erts_smp_mtx_unlock(&internal_state.w.f.mtime_mtx);
+
+    return (ErtsMonotonicTime) res*1000;
+}
+
+static ErtsMonotonicTime
+os_monotonic_time_gtc64(void) 
+{
+    ULONGLONG ticks = (*internal_state.r.o.pGetTickCount64)();
+    return (ErtsMonotonicTime) ticks*1000;
+}
+
+/*
+ * Init
+ */
+
+void
+sys_init_time(ErtsSysInitTimeResult *init_resp)
+{
+    ErtsMonotonicTime (*os_mtime_func)(void);
+    ErtsMonotonicTime time_unit;
     char kernel_dll_name[] = "kernel32";
     HMODULE module;
 
+    init_resp->os_monotonic_info.clock_id = NULL;
+
     module = GetModuleHandle(kernel_dll_name);
-    pGetTickCount64 = (module != NULL) ? 
-	(ULONGLONG (WINAPI *)(void)) 
-	GetProcAddress(module,"GetTickCount64") : 
-	NULL;
+    if (!module) {
+    get_tick_count:
+	erts_smp_mtx_init(&internal_state.w.f.mtime_mtx,
+			  "os_monotonic_time");
+	internal_state.w.f.wrap = 0;
+	internal_state.w.f.last_tick_count = 0;
+
+	init_resp->os_monotonic_info.func = "GetTickCount";
+	init_resp->os_monotonic_info.locked_use = 1;
+	init_resp->os_monotonic_info.resolution = 1000;
+	time_unit = (ErtsMonotonicTime) 1000*1000;
+	os_mtime_func = os_monotonic_time_gtc32;
+    }
+    else {
+	int major, minor, build;
+
+	os_version(&major, &minor, &build);
+
+	if (major < 6) {
+
+	get_tick_count64:
+
+	    internal_state.r.o.pGetTickCount64
+		= ((ULONGLONG (WINAPI *)(void))
+		   GetProcAddress(module, "GetTickCount64"));
+	    if (!internal_state.r.o.pGetTickCount64)
+		goto get_tick_count;
+
+	    init_resp->os_monotonic_info.func = "GetTickCount64";
+	    init_resp->os_monotonic_info.locked_use = 0;
+	    init_resp->os_monotonic_info.resolution = 1000;
+	    time_unit = (ErtsMonotonicTime) 1000*1000;
+	    os_mtime_func = os_monotonic_time_gtc64;
+	}
+	else { /* Vista or newer... */
+
+	    LARGE_INTEGER pf;
+	    BOOL (WINAPI *QPF)(LARGE_INTEGER *);
+
+	    QPF = ((BOOL (WINAPI *)(LARGE_INTEGER *))
+		   GetProcAddress(module, "QueryPerformanceFrequency"));
+	    if (!QPF)
+		goto get_tick_count64;
+	    if (!(*QPF)(&pf))
+		goto get_tick_count64;
+	    /*
+	     * We only use QueryPerformanceCounter() if
+	     * its frequency is equal to, or larger than
+	     * GHz in order to ensure that the user wont
+	     * be able to observe faulty order between
+	     * values retrieved on different threads.
+	     */
+	    if (pf.QuadPart < (LONGLONG) 1000*1000*1000)
+		goto get_tick_count64;
+	    internal_state.r.o.pQueryPerformanceCounter
+		= ((BOOL (WINAPI *)(LARGE_INTEGER *))
+		   GetProcAddress(module, "QueryPerformanceCounter"));
+	    if (!internal_state.r.o.pQueryPerformanceCounter)
+		goto get_tick_count64;
+
+	    init_resp->os_monotonic_info.func = "QueryPerformanceCounter";
+	    init_resp->os_monotonic_info.locked_use = 0;
+	    time_unit = (ErtsMonotonicTime) pf.QuadPart;
+	    init_resp->os_monotonic_info.resolution = time_unit;
+	    os_mtime_func = os_monotonic_time_qpc;
+	}
+    }
+
+    erts_sys_time_data__.r.o.os_monotonic_time = os_mtime_func;
+    init_resp->os_monotonic_time_unit = time_unit;
+    init_resp->have_os_monotonic = 1;
+    init_resp->sys_clock_resolution = 1;
 
     if(GetTimeZoneInformation(&static_tzi) && 
        static_tzi.StandardDate.wMonth != 0 &&
@@ -94,9 +233,6 @@ sys_init_time(void)
 	have_static_tzi = 1;
     }
 
-    erts_smp_mtx_init(&wrap_lock, "sys_gethrtime");
-
-    return 1;
 }
 
 /* Returns a switchtimes for DST as UTC filetimes given data from a 
@@ -377,41 +513,6 @@ sys_gettimeofday(SysTimeval *tv)
 			 EPOCH_JULIAN_DIFF);
 }
 
-extern int erts_initialized;
-SysHrTime 
-sys_gethrtime(void) 
-{
-    if (pGetTickCount64 != NULL) {
-	return ((SysHrTime) pGetTickCount64()) * LL_LITERAL(1000000);
-    } else {
-	DWORD ticks;
-	SysHrTime res;
-	erts_smp_mtx_lock(&wrap_lock);
-	ticks = (SysHrTime) (GetTickCount() & 0x7FFFFFFF);
-	if (ticks < (SysHrTime) last_tick_count) {
-	    /* Detect a race that should no longer be here... */
-	    if ((((SysHrTime) last_tick_count) - ((SysHrTime) ticks)) > 1000) {
-		wrap += LL_LITERAL(1) << 31;
-	    } else {
-		/* 
-		 * XXX Debug: Violates locking order, remove all this,
-		 * after testing!
-		 */
-		erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
-		erts_dsprintf(dsbufp, "Did not wrap when last_tick %d "
-			      "and tick %d", 
-			      last_tick_count, ticks);
-		erts_send_error_to_logger_nogl(dsbufp);
-		ticks = last_tick_count;
-	    }
-	}
-	last_tick_count = ticks;
-	res = ((((LONGLONG) ticks) + wrap) * LL_LITERAL(1000000));
-	erts_smp_mtx_unlock(&wrap_lock);
-	return res;
-    }
-}
-
 clock_t 
 sys_times(SysTimes *buffer) {
     clock_t kernel_ticks = (GetTickCount() / 
diff --git a/erts/emulator/test/Makefile b/erts/emulator/test/Makefile
index dfbe47786a..dd2e2cb504 100644
--- a/erts/emulator/test/Makefile
+++ b/erts/emulator/test/Makefile
@@ -108,6 +108,7 @@ MODULES= \
 	trace_call_time_SUITE \
 	scheduler_SUITE \
 	old_scheduler_SUITE \
+	unique_SUITE \
 	z_SUITE \
 	old_mod \
 	long_timers_test \
diff --git a/erts/emulator/test/long_timers_test.erl b/erts/emulator/test/long_timers_test.erl
index 28a4fba9f6..f381332b51 100644
--- a/erts/emulator/test/long_timers_test.erl
+++ b/erts/emulator/test/long_timers_test.erl
@@ -28,7 +28,7 @@
 
 
 -define(MAX_TIMEOUT, 60). % Minutes
--define(MAX_LATE, 10*1000). % Milliseconds
+-define(MAX_LATE_MS, 10*1000). % Milliseconds
 -define(REG_NAME, '___LONG___TIMERS___TEST___SERVER___').
 
 -define(DRV_NAME, timer_driver).
@@ -75,7 +75,7 @@ check_result() ->
 	    erlang:demonitor(Mon),
 	    receive {'DOWN', Mon, _, _, _} -> ok after 0 -> ok end,
 	    stop_node(Node),
-	    check(TORs, (timer:now_diff(End, Start) div 1000) - ?MAX_LATE, ok)
+	    check(TORs, ms((End - Start) - max_late()), ok)
     end.
 
 check([#timeout_rec{timeout = Timeout,
@@ -83,7 +83,7 @@ check([#timeout_rec{timeout = Timeout,
 		    timeout_diff = undefined} | TORs],
       NeedRes,
       _Ok) when Timeout < NeedRes ->
-    io:format("~p timeout = ~p failed! No timeout.~n",
+    io:format("~p timeout = ~p ms failed! No timeout.~n",
 	      [Type, Timeout]),
     check(TORs, NeedRes, failed);
 check([#timeout_rec{timeout_diff = undefined} | TORs],
@@ -95,7 +95,7 @@ check([#timeout_rec{timeout = Timeout,
 		    timeout_diff = {error, Reason}} | TORs],
       NeedRes,
       _Ok) ->
-    io:format("~p timeout = ~p failed! exit reason ~p~n",
+    io:format("~p timeout = ~p ms failed! exit reason ~p~n",
 	      [Type, Timeout, Reason]),
     check(TORs, NeedRes, failed);
 check([#timeout_rec{timeout = Timeout,
@@ -103,43 +103,77 @@ check([#timeout_rec{timeout = Timeout,
 		    timeout_diff = TimeoutDiff} | TORs],
       NeedRes,
       Ok) ->
-    case (0 =< TimeoutDiff) and (TimeoutDiff =< ?MAX_LATE) of
-	true ->
-	    io:format("~p timeout = ~p succeded! timeout diff = ~p.~n",
-		      [Type, Timeout, TimeoutDiff]),
-	    check(TORs, NeedRes, Ok);
-	false ->
-	    io:format("~p timeout = ~p failed! timeout diff = ~p.~n",
-		      [Type, Timeout, TimeoutDiff]),
-	    check(TORs, NeedRes, failed)
-    end;
+    {NewOk, SuccessStr} = case ((0 =< TimeoutDiff)
+				andalso (TimeoutDiff =< max_late())) of
+			      true -> {Ok, "succeeded"};
+			      false -> {failed, "FAILED"}
+			  end,
+    io:format("~s timeout = ~s ms ~s! timeout diff = ~s.~n",
+	      [type_str(Type),
+	       time_str(Timeout),
+	       SuccessStr,
+	       time_str(TimeoutDiff, erlang:convert_time_unit(1, seconds, native))]),
+    check(TORs, NeedRes, NewOk);
 check([], _NeedRes, Ok) ->
     Ok.
 
+type_str(receive_after) -> "receive ... after";
+type_str(bif_timer) -> "BIF timer";
+type_str(driver) -> "driver".
+
+time_str(Time, Unit) ->
+    lists:flatten([time_str(Time), " ", unit_str(Unit)]).
+
+time_str(Time) ->
+    lists:reverse(conv_time_str(lists:reverse(integer_to_list(Time)))).
+
+conv_time_str([X,Y,Z,C|Cs]) when C /= $- ->
+    [X,Y,Z,$`|conv_time_str([C|Cs])];
+conv_time_str(Cs) ->
+    Cs.
+
+unit_str(1) -> "s";
+unit_str(1000) -> "ms";
+unit_str(1000000) -> "us";
+unit_str(1000000000) -> "ns";
+unit_str(Res) when is_integer(Res) -> ["/ ", integer_to_list(Res), " s"];
+unit_str(Res) -> Res.
+
+to_diff(Timeout, Start, Stop) ->
+    %% 'Timeout' in milli seconds
+    %% 'Start', 'Stop', and result in native unit
+    (Stop - Start) - erlang:convert_time_unit(Timeout, milli_seconds, native).
+
+ms(Time) ->
+    erlang:convert_time_unit(Time, native, milli_seconds).
+
+max_late() ->
+    erlang:convert_time_unit(?MAX_LATE_MS, milli_seconds, native).
+
 receive_after(Timeout) ->
-    Start = now(),
+    Start = erlang:monotonic_time(),
     receive
 	{get_result, ?REG_NAME} ->
 	    ?REG_NAME ! #timeout_rec{pid = self(),
 				     type = receive_after,
 				     timeout = Timeout}
     after Timeout ->
-	    Stop = now(),
+	    Stop = erlang:monotonic_time(),
 	    receive
 		{get_result, ?REG_NAME} ->
-	    	    TimeoutDiff = ((timer:now_diff(Stop, Start) div 1000)
-				   - Timeout),
 		    ?REG_NAME ! #timeout_rec{pid = self(),
 					     type = receive_after,
 					     timeout = Timeout,
-					     timeout_diff = TimeoutDiff}
+					     timeout_diff = to_diff(Timeout,
+								    Start,
+								    Stop)}
 	    end
     end.
 
 driver(Timeout) ->
     Port = open_port({spawn, ?DRV_NAME},[]),
     link(Port),
-    Start = now(),
+    Start = erlang:monotonic_time(),
     erlang:port_command(Port, <<?START_TIMER, Timeout:32>>),
     receive
 	{get_result, ?REG_NAME} ->
@@ -147,38 +181,38 @@ driver(Timeout) ->
 				     type = driver,
 				     timeout = Timeout};
 	{Port,{data,[?TIMER]}} ->
-	    Stop = now(),
+	    Stop = erlang:monotonic_time(),
 	    unlink(Port),
 	    true = erlang:port_close(Port),
 	    receive
 		{get_result, ?REG_NAME} ->
-	    	    TimeoutDiff = ((timer:now_diff(Stop, Start) div 1000)
-				   - Timeout),
 		    ?REG_NAME ! #timeout_rec{pid = self(),
 					     type = driver,
 					     timeout = Timeout,
-					     timeout_diff = TimeoutDiff}
+					     timeout_diff = to_diff(Timeout,
+								    Start,
+								    Stop)}
 	    end
     end.
 
 bif_timer(Timeout) ->
     Tmr = erlang:start_timer(Timeout, self(), ok),
-    Start = now(),
+    Start = erlang:monotonic_time(),
     receive
 	{get_result, ?REG_NAME} ->
 	    ?REG_NAME ! #timeout_rec{pid = self(),
 				     type = bif_timer,
 				     timeout = Timeout};
 	{timeout, Tmr, ok} ->
-	    Stop = now(),
+	    Stop = erlang:monotonic_time(),
 	    receive
 		{get_result, ?REG_NAME} ->
-	    	    TimeoutDiff = ((timer:now_diff(Stop, Start) div 1000)
-				   - Timeout),
 		    ?REG_NAME ! #timeout_rec{pid = self(),
 					     type = bif_timer,
 					     timeout = Timeout,
-					     timeout_diff = TimeoutDiff}
+					     timeout_diff = to_diff(Timeout,
+								    Start,
+								    Stop)}
 	    end
     end.
 
@@ -189,7 +223,7 @@ test(Starter, DrvDir, StartDone) ->
     register(?REG_NAME, self()),
     {group_leader, GL} = process_info(whereis(net_kernel),group_leader),
     group_leader(GL, self()),
-    Start = now(),
+    Start = erlang:monotonic_time(),
     TORs = lists:map(fun (Min) ->
 			     TO = Min*60*1000,
 			     [#timeout_rec{pid = spawn_opt(
@@ -222,7 +256,7 @@ test(Starter, DrvDir, StartDone) ->
 test_loop(TORs, Start) ->
     receive
 	{get_result, ?REG_NAME, Pid} ->
-	    End = now(),
+	    End = erlang:monotonic_time(),
 	    Pid ! {result, ?REG_NAME, get_test_results(TORs), Start, End},
 	    erl_ddll:unload_driver(?DRV_NAME),
 	    erl_ddll:stop(),
diff --git a/erts/emulator/test/monitor_SUITE.erl b/erts/emulator/test/monitor_SUITE.erl
index aec59867d8..07e2862b2a 100644
--- a/erts/emulator/test/monitor_SUITE.erl
+++ b/erts/emulator/test/monitor_SUITE.erl
@@ -26,7 +26,8 @@
 	 case_1/1, case_1a/1, case_2/1, case_2a/1, mon_e_1/1, demon_e_1/1, demon_1/1,
 	 demon_2/1, demon_3/1, demonitor_flush/1,
 	 local_remove_monitor/1, remote_remove_monitor/1, mon_1/1, mon_2/1,
-	 large_exit/1, list_cleanup/1, mixer/1, named_down/1, otp_5827/1]).
+	 large_exit/1, list_cleanup/1, mixer/1, named_down/1, otp_5827/1,
+	 monitor_time_offset/1]).
 
 -export([init_per_testcase/2, end_per_testcase/2]).
 
@@ -38,7 +39,8 @@ all() ->
     [case_1, case_1a, case_2, case_2a, mon_e_1, demon_e_1,
      demon_1, mon_1, mon_2, demon_2, demon_3,
      demonitor_flush, {group, remove_monitor}, large_exit,
-     list_cleanup, mixer, named_down, otp_5827].
+     list_cleanup, mixer, named_down, otp_5827,
+     monitor_time_offset].
 
 groups() -> 
     [{remove_monitor, [],
@@ -59,7 +61,7 @@ end_per_group(_GroupName, Config) ->
 
 init_per_testcase(Func, Config) when is_atom(Func), is_list(Config) ->
     Dog=?t:timetrap(?t:minutes(15)),
-    [{watchdog, Dog}|Config].
+    [{watchdog, Dog},{testcase, Func}|Config].
 
 end_per_testcase(_Func, Config) ->
     Dog=?config(watchdog, Config),
@@ -837,6 +839,89 @@ otp_5827(Config) when is_list(Config) ->
 		  ?line ?t:fail("erlang:monitor/2 hangs")
 	  end.
 
+monitor_time_offset(Config) when is_list(Config) ->
+    {ok, Node} = start_node(Config, "+C single_time_warp"),
+    Me = self(),
+    PMs = lists:map(fun (_) ->
+			    Pid = spawn(Node,
+					fun () ->
+						check_monitor_time_offset(Me)
+					end),
+			    {Pid, erlang:monitor(process, Pid)}
+		    end,
+		    lists:seq(1, 100)),
+    lists:foreach(fun ({P, _M}) ->
+			  P ! check_no_change_message
+		  end, PMs),
+    lists:foreach(fun ({P, M}) ->
+			  receive
+			      {no_change_message_received, P} ->
+				  ok;
+			      {'DOWN', M, process, P, Reason} ->
+				  ?t:fail(Reason)
+			  end
+		  end, PMs),
+    preliminary = rpc:call(Node, erlang, system_flag, [time_offset, finalize]),
+    lists:foreach(fun ({P, M}) ->
+			  receive
+			      {change_messages_received, P} ->
+				  erlang:demonitor(M, [flush]);
+			      {'DOWN', M, process, P, Reason} ->
+				  ?t:fail(Reason)
+			  end
+		  end, PMs),
+    stop_node(Node),
+    ok.
+
+check_monitor_time_offset(Leader) ->
+    Mon1 = erlang:monitor(time_offset, clock_service),
+    Mon2 = erlang:monitor(time_offset, clock_service),
+    Mon3 = erlang:monitor(time_offset, clock_service),
+    Mon4 = erlang:monitor(time_offset, clock_service),
+
+    erlang:demonitor(Mon2, [flush]),
+    
+    Mon5 = erlang:monitor(time_offset, clock_service),
+    Mon6 = erlang:monitor(time_offset, clock_service),
+    Mon7 = erlang:monitor(time_offset, clock_service),
+
+    receive check_no_change_message -> ok end,
+    receive
+	{'CHANGE', _, time_offset, clock_service, _} ->
+	    exit(unexpected_change_message_received)
+    after 0 ->
+	    Leader ! {no_change_message_received, self()}
+    end,
+    receive after 100 -> ok end,
+    erlang:demonitor(Mon4, [flush]),
+    receive
+	{'CHANGE', Mon3, time_offset, clock_service, _} ->
+	    ok
+    end,
+    receive
+	{'CHANGE', Mon6, time_offset, clock_service, _} ->
+	    ok
+    end,
+    erlang:demonitor(Mon5, [flush]),
+    receive
+	{'CHANGE', Mon7, time_offset, clock_service, _} ->
+	    ok
+    end,
+    receive
+	{'CHANGE', Mon1, time_offset, clock_service, _} ->
+	    ok
+    end,
+    receive
+	{'CHANGE', _, time_offset, clock_service, _} ->
+	    exit(unexpected_change_message_received)
+    after 1000 ->
+	    ok
+    end,
+    Leader ! {change_messages_received, self()}.
+
+%%
+%% ...
+%%
 
 wait_for_m(_,_,0) ->
     exit(monitor_wait_timeout);
@@ -959,3 +1044,25 @@ generate(_Fun, 0) ->
     [];
 generate(Fun, N) ->
     [Fun() | generate(Fun, N-1)].
+
+start_node(Config) ->
+    start_node(Config, "").
+
+start_node(Config, Args) ->
+    TestCase = ?config(testcase, Config),
+    PA = filename:dirname(code:which(?MODULE)),
+    ESTime = erlang:monotonic_time(1) + erlang:time_offset(1),
+    Unique = erlang:unique_integer([positive]),
+    Name = list_to_atom(atom_to_list(?MODULE)
+			++ "-"
+			++ atom_to_list(TestCase)
+			++ "-"
+			++ integer_to_list(ESTime)
+			++ "-"
+			++ integer_to_list(Unique)),
+    test_server:start_node(Name,
+			   slave,
+			   [{args, "-pa " ++ PA ++ " " ++ Args}]).
+
+stop_node(Node) ->
+    test_server:stop_node(Node).
diff --git a/erts/emulator/test/time_SUITE.erl b/erts/emulator/test/time_SUITE.erl
index a0a8a9c42c..43f7ac7f7c 100644
--- a/erts/emulator/test/time_SUITE.erl
+++ b/erts/emulator/test/time_SUITE.erl
@@ -34,7 +34,14 @@
 	 bad_univ_to_local/1, bad_local_to_univ/1,
 	 univ_to_seconds/1, seconds_to_univ/1,
 	 consistency/1,
-	 now_unique/1, now_update/1, timestamp/1]).
+	 now_unique/1, now_update/1, timestamp/1,
+	 time_warp_modes/1,
+	 monotonic_time_monotonicity/1,
+	 time_unit_conversion/1,
+	 signed_time_unit_conversion/1,
+	 erlang_timestamp/1]).
+
+-export([init_per_testcase/2, end_per_testcase/2]).
 
 -export([local_to_univ_utc/1]).
 
@@ -56,6 +63,12 @@
 
 -define(dst_timezone, 2).
 
+init_per_testcase(Func, Config) when is_atom(Func), is_list(Config) ->
+    [{testcase, Func}|Config].
+
+end_per_testcase(_Func, Config) ->
+    ok.
+
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
@@ -63,7 +76,12 @@ all() ->
      bad_univ_to_local, bad_local_to_univ, 
      univ_to_seconds, seconds_to_univ,
      consistency,
-     {group, now}, timestamp].
+     {group, now}, timestamp,
+     time_warp_modes,
+     monotonic_time_monotonicity,
+     time_unit_conversion,
+     signed_time_unit_conversion,
+     erlang_timestamp].
 
 groups() -> 
     [{now, [], [now_unique, now_update]}].
@@ -420,6 +438,368 @@ now_update1(N) when N > 0 ->
 now_update1(0) ->
     ?line test_server:fail().
 
+time_warp_modes(Config) when is_list(Config) ->
+    %% All time warp modes always supported in
+    %% combination with no time correction...
+    check_time_warp_mode(Config, false, no_time_warp),
+    check_time_warp_mode(Config, false, single_time_warp),
+    check_time_warp_mode(Config, false, multi_time_warp),
+
+    erts_debug:set_internal_state(available_internal_state, true),
+    try
+	case erts_debug:get_internal_state({check_time_config,
+					    true, no_time_warp}) of
+	    false -> ok;
+	    true -> check_time_warp_mode(Config, true, no_time_warp)
+	end,
+	case erts_debug:get_internal_state({check_time_config,
+					    true, single_time_warp}) of
+	    false -> ok;
+	    true -> check_time_warp_mode(Config, true, single_time_warp)
+	end,
+	case erts_debug:get_internal_state({check_time_config,
+					    true, multi_time_warp}) of
+	    false -> ok;
+	    true -> check_time_warp_mode(Config, true, multi_time_warp)
+	end
+    after
+	erts_debug:set_internal_state(available_internal_state, false)
+    end.
+
+check_time_warp_mode(Config, TimeCorrection, TimeWarpMode) ->
+    io:format("~n~n~n***** Testing TimeCorrection=~p TimeWarpMode=~p *****~n",
+	      [TimeCorrection, TimeWarpMode]),
+    Mon = erlang:monitor(time_offset, clock_service),
+    _ = erlang:time_offset(),
+    Start = erlang:monotonic_time(1000),
+    MonotonicityTimeout = 2000,
+    {ok, Node} = start_node(Config,
+			    "+c " ++ atom_to_list(TimeCorrection)
+			    ++ " +C " ++ atom_to_list(TimeWarpMode)),
+    StartTime = rpc:call(Node, erlang, system_info, [start_time]),
+    Me = self(),
+    MonotincityTestStarted = make_ref(),
+    MonotincityTestDone = make_ref(),
+    spawn_link(Node,
+	       fun () ->
+		       Me ! MonotincityTestStarted,
+		       cmp_times(erlang:start_timer(MonotonicityTimeout,
+						    self(),
+						    timeout),
+				 erlang:monotonic_time()),
+		       Me ! MonotincityTestDone
+	       end),
+    receive MonotincityTestStarted -> ok end,
+    check_time_offset(Node, TimeWarpMode),
+    TimeWarpMode = rpc:call(Node, erlang, system_info, [time_warp_mode]),
+    TimeCorrection = rpc:call(Node, erlang, system_info, [time_correction]),
+    receive MonotincityTestDone -> ok end,
+    MonotonicTime = rpc:call(Node, erlang, monotonic_time, []),
+    MonotonicTimeUnit = rpc:call(Node,
+				       erlang,
+				       convert_time_unit,
+				       [1, seconds, native]),
+    UpMilliSeconds = erlang:convert_time_unit(MonotonicTime - StartTime,
+					      MonotonicTimeUnit,
+					      milli_seconds),
+    io:format("UpMilliSeconds=~p~n", [UpMilliSeconds]),
+    End = erlang:monotonic_time(milli_seconds),
+    stop_node(Node),
+    try
+	true = (UpMilliSeconds > (98*MonotonicityTimeout) div 100),
+	true = (UpMilliSeconds < (102*(End-Start)) div 100)
+    catch
+	error:_ ->
+	    io:format("Uptime inconsistency", []),
+	    case {TimeCorrection, erlang:system_info(time_correction)} of
+		{true, true} ->
+		    ?t:fail(uptime_inconsistency);
+		{true, false} ->
+		    _ = erlang:time_offset(),
+		    receive
+			{'CHANGE', Mon, time_offset, clock_service, _} ->
+			    ignore
+		    after 1000 ->
+			    ?t:fail(uptime_inconsistency)
+		    end;
+		_ ->
+		    ignore
+	    end
+    end,
+    erlang:demonitor(Mon, [flush]),
+    ok.
+
+check_time_offset(Node, no_time_warp) ->
+    final = rpc:call(Node, erlang, system_info, [time_offset]),
+    final = rpc:call(Node, erlang, system_flag, [time_offset, finalize]),
+    final = rpc:call(Node, erlang, system_info, [time_offset]);
+check_time_offset(Node, single_time_warp) ->
+    preliminary = rpc:call(Node, erlang, system_info, [time_offset]),
+    preliminary = rpc:call(Node, erlang, system_flag, [time_offset, finalize]),
+    final = rpc:call(Node, erlang, system_info, [time_offset]),
+    final = rpc:call(Node, erlang, system_flag, [time_offset, finalize]);
+check_time_offset(Node, multi_time_warp) ->
+    volatile = rpc:call(Node, erlang, system_info, [time_offset]),
+    volatile = rpc:call(Node, erlang, system_flag, [time_offset, finalize]),
+    volatile = rpc:call(Node, erlang, system_info, [time_offset]).
+
+monotonic_time_monotonicity(Config) when is_list(Config) ->
+    Done = erlang:start_timer(10000,self(),timeout),
+    cmp_times(Done, erlang:monotonic_time()).
+
+cmp_times(Done, X0) ->
+    X1 = erlang:monotonic_time(),
+    X2 = erlang:monotonic_time(),
+    X3 = erlang:monotonic_time(),
+    X4 = erlang:monotonic_time(),
+    X5 = erlang:monotonic_time(),
+    true = (X0 =< X1),
+    true = (X1 =< X2),
+    true = (X2 =< X3),
+    true = (X3 =< X4),
+    true = (X4 =< X5),
+    receive
+	{timeout, Done, timeout} ->
+	    ok
+    after 0 ->
+	    cmp_times(Done, X5)
+    end.
+
+-define(CHK_RES_CONVS_TIMEOUT, 400).
+
+time_unit_conversion(Config) when is_list(Config) ->
+    Mon = erlang:monitor(time_offset, clock_service),
+    start_check_res_convs(Mon, 1000000000000),
+    start_check_res_convs(Mon, 2333333333333),
+    start_check_res_convs(Mon, 5732678356789),
+    erlang:demonitor(Mon, [flush]).
+    
+start_check_res_convs(Mon, Res) ->
+    io:format("Checking ~p time_unit~n", [Res]),
+    check_res_convs(Mon,
+		    erlang:start_timer(?CHK_RES_CONVS_TIMEOUT,
+				       self(),
+				       timeout),
+		    Res).
+    
+
+check_res_convs(Mon, Done, Res) ->
+    receive
+	{timeout, Done, timeout} ->
+	    case Res div 10 of
+		0 ->
+		    ok;
+		NewRes ->
+		    start_check_res_convs(Mon, NewRes)
+	    end
+    after 0 ->
+	    do_check_res_convs(Mon, Done, Res)
+    end.
+
+do_check_res_convs(Mon, Done, Res) ->
+    TStart = erlang:monotonic_time(),
+    T = erlang:monotonic_time(Res),
+    TEnd = erlang:monotonic_time(),
+    TMin = erlang:convert_time_unit(TStart, native, Res),
+    TMax = erlang:convert_time_unit(TEnd, native, Res),
+    %io:format("~p =< ~p =< ~p~n", [TMin, T, TEnd]),
+    true = (TMin =< T),
+    true = (TMax >= T),
+    check_time_offset_res_conv(Mon, Res),
+    check_res_convs(Mon, Done, Res).
+
+
+check_time_offset_res_conv(Mon, Res) ->
+    TORes = erlang:time_offset(Res),
+    TO = erlang:time_offset(),
+    case erlang:convert_time_unit(TO, native, Res) of
+	TORes ->
+	    ok;
+	TORes2 ->
+	    case check_time_offset_change(Mon, TO, 1000) of
+		{TO, false} ->
+		    ?t:fail({time_unit_conversion_inconsistency,
+			     TO, TORes, TORes2});
+		{_NewTO, true} ->
+		    ?t:format("time_offset changed", []),
+		    check_time_offset_res_conv(Mon, Res)
+	    end
+    end.
+
+signed_time_unit_conversion(Config) when is_list(Config) ->
+    chk_strc(1000000000, 1000000),
+    chk_strc(1000000000, 1000),
+    chk_strc(1000000000, 1),
+    chk_strc(1000000, 1000),
+    chk_strc(1000000, 1),
+    chk_strc(1000, 1),
+    chk_strc(4711, 17),
+    chk_strc(1 bsl 10, 1),
+    chk_strc(1 bsl 16, 10),
+    chk_strc(1 bsl 17, 1 bsl 8),
+    chk_strc((1 bsl 17) + 1, (1 bsl 8) - 1),
+    chk_strc(1 bsl 17, 11),
+    ok.
+
+chk_strc(Res0, Res1) ->
+    case (Res0 /= Res1) andalso (Res0 =< 1000000) andalso (Res1 =< 1000000) of
+	true ->
+	    {FromRes, ToRes} = case Res0 > Res1 of
+				   true -> {Res0, Res1};
+				   false -> {Res1, Res0}
+			       end,
+	    MinFromValuesPerToValue = FromRes div ToRes,
+	    MaxFromValuesPerToValue = ((FromRes-1) div ToRes)+1,
+	    io:format("~p -> ~p [~p, ~p]~n",
+		      [FromRes, ToRes,
+		       MinFromValuesPerToValue, MaxFromValuesPerToValue]),
+	    chk_values_per_value(FromRes, ToRes,
+				 -10*FromRes, 10*FromRes,
+				 MinFromValuesPerToValue,
+				 MaxFromValuesPerToValue,
+				 undefined, MinFromValuesPerToValue);
+	_ ->
+	    ok
+    end,
+    chk_random_values(Res0, Res1),
+    chk_random_values(Res1, Res0),
+    ok.
+
+chk_random_values(FR, TR) ->
+%    case (FR rem TR == 0) orelse (TR rem FR == 0) of
+%	true ->
+	    io:format("rand values ~p -> ~p~n", [FR, TR]),
+	    random:seed(268438039, 268440479, 268439161),
+	    Values = lists:map(fun (_) -> random:uniform(1 bsl 65) - (1 bsl 64) end,
+			       lists:seq(1, 100000)),
+	    CheckFun = fun (V) ->
+			       CV = erlang:convert_time_unit(V, FR, TR),
+			       case {(FR*CV) div TR =< V,
+				     (FR*(CV+1)) div TR >= V} of
+				   {true, true} ->
+				       ok;
+				   Failure ->
+				       ?t:fail({Failure, CV, V, FR, TR})
+			       end
+		       end,
+	    lists:foreach(CheckFun, Values).%;
+%	false -> ok
+%    end.
+		       
+
+chk_values_per_value(_FromRes, _ToRes,
+	 EndValue, EndValue,
+	 MinFromValuesPerToValue, MaxFromValuesPerToValue,
+	 _ToValue, FromValueCount) ->
+%    io:format("~p [~p]~n", [EndValue, FromValueCount]),
+    case ((MinFromValuesPerToValue =< FromValueCount)
+	  andalso (FromValueCount =< MaxFromValuesPerToValue)) of
+	false ->
+	    ?t:fail({MinFromValuesPerToValue,
+		     FromValueCount,
+		     MaxFromValuesPerToValue});
+	true ->
+	    ok
+    end;
+chk_values_per_value(FromRes, ToRes, Value, EndValue,
+		     MinFromValuesPerToValue, MaxFromValuesPerToValue,
+		     ToValue, FromValueCount) ->
+    case erlang:convert_time_unit(Value, FromRes, ToRes) of
+	ToValue ->
+	    chk_values_per_value(FromRes, ToRes,
+				 Value+1, EndValue,
+				 MinFromValuesPerToValue,
+				 MaxFromValuesPerToValue,
+				 ToValue, FromValueCount+1);
+	NewToValue ->
+	    case ((MinFromValuesPerToValue =< FromValueCount)
+		  andalso (FromValueCount =< MaxFromValuesPerToValue)) of
+		false ->
+		    ?t:fail({MinFromValuesPerToValue,
+			     FromValueCount,
+			     MaxFromValuesPerToValue});
+		true ->
+%		    io:format("~p -> ~p [~p]~n",
+%			      [Value, NewToValue, FromValueCount]),
+		    chk_values_per_value(FromRes, ToRes,
+					 Value+1, EndValue,
+					 MinFromValuesPerToValue,
+					 MaxFromValuesPerToValue,
+					 NewToValue, 1)
+	    end
+    end.
+
+erlang_timestamp(Config) when is_list(Config) ->
+    Mon = erlang:monitor(time_offset, clock_service),
+    {TO, _} = check_time_offset_change(Mon,
+				       erlang:time_offset(),
+				       0),
+    Done = erlang:start_timer(10000,self(),timeout),
+    ok = check_erlang_timestamp(Done, Mon, TO).
+
+check_erlang_timestamp(Done, Mon, TO) ->
+    receive
+	{timeout, Done, timeout} ->
+	    erlang:demonitor(Mon, [flush]),
+	    ok
+    after 0 ->
+	    do_check_erlang_timestamp(Done, Mon, TO)
+    end.
+
+do_check_erlang_timestamp(Done, Mon, TO) ->
+    MinMon = erlang:monotonic_time(),
+    {MegaSec, Sec, MicroSec} = erlang:timestamp(),
+    MaxMon = erlang:monotonic_time(),
+    TsMin = erlang:convert_time_unit(MinMon+TO,
+				     native,
+				     micro_seconds),
+    TsMax = erlang:convert_time_unit(MaxMon+TO,
+				     native,
+				     micro_seconds),
+    TsTime = (MegaSec*1000000+Sec)*1000000+MicroSec,
+    case (TsMin =< TsTime) andalso (TsTime =< TsMax) of
+	true ->
+	    NewTO = case erlang:time_offset() of
+			TO ->
+			    TO;
+			_ ->
+			    check_time_offset_change(Mon, TO, 0)
+		    end,
+	    check_erlang_timestamp(Done, Mon, NewTO);
+	false ->
+	    io:format("TsMin=~p TsTime=~p TsMax=~p~n", [TsMin, TsTime, TsMax]),
+	    ?t:format("Detected inconsistency; "
+		      "checking for time_offset change...", []),
+	    case check_time_offset_change(Mon, TO, 1000) of
+		{TO, false} ->
+		    ?t:fail(timestamp_inconsistency);
+		{NewTO, true} ->
+		    ?t:format("time_offset changed", []),
+		    check_erlang_timestamp(Done, Mon, NewTO)
+	    end
+    end.
+
+check_time_offset_change(Mon, TO, Wait) ->
+    process_changed_time_offset(Mon, TO, false, Wait).
+
+process_changed_time_offset(Mon, TO, Changed, Wait) ->
+    receive
+	{'CHANGE', Mon, time_offset, clock_service, NewTO} ->
+	    process_changed_time_offset(Mon, NewTO, true, Wait)
+    after Wait ->
+	    case erlang:time_offset() of
+		TO ->
+		    {TO, Changed};
+		_OtherTO ->
+		    receive
+			{'CHANGE', Mon, time_offset, clock_service, NewTO} ->
+			    process_changed_time_offset(Mon, NewTO, true, Wait)
+		    end
+	    end
+    end.
+    
+
+
 %% Returns the test data: a list of {Utc, Local} tuples.
 
 test_data() ->
@@ -554,4 +934,25 @@ bad_dates() ->
 
      {{1996, 4, 30}, {12, 0, -1}},		% Sec
      {{1996, 4, 30}, {12, 0, 60}}].
-     
+
+start_node(Config) ->
+    start_node(Config, "").
+
+start_node(Config, Args) ->
+    TestCase = ?config(testcase, Config),
+    PA = filename:dirname(code:which(?MODULE)),
+    ESTime = erlang:monotonic_time(1) + erlang:time_offset(1),
+    Unique = erlang:unique_integer([positive]),
+    Name = list_to_atom(atom_to_list(?MODULE)
+			++ "-"
+			++ atom_to_list(TestCase)
+			++ "-"
+			++ integer_to_list(ESTime)
+			++ "-"
+			++ integer_to_list(Unique)),
+    test_server:start_node(Name,
+			   slave,
+			   [{args, "-pa " ++ PA ++ " " ++ Args}]).
+
+stop_node(Node) ->
+    test_server:stop_node(Node).
diff --git a/erts/emulator/test/timer_bif_SUITE.erl b/erts/emulator/test/timer_bif_SUITE.erl
index c28224729d..da19be3424 100644
--- a/erts/emulator/test/timer_bif_SUITE.erl
+++ b/erts/emulator/test/timer_bif_SUITE.erl
@@ -238,6 +238,7 @@ cleanup(Config) when is_list(Config) ->
     ?line wait_until(fun () -> process_is_cleaned_up(P1) end),
     ?line T1 = erlang:start_timer(10000, P1, "hej"),
     ?line T2 = erlang:send_after(10000, P1, "hej"),
+    receive after 1000 -> ok end,
     ?line Mem = mem(),
     ?line false = erlang:read_timer(T1),
     ?line false = erlang:read_timer(T2),
@@ -250,6 +251,7 @@ cleanup(Config) when is_list(Config) ->
     ?line true = is_integer(erlang:read_timer(T3)),
     ?line true = is_integer(erlang:read_timer(T4)),
     ?line wait_until(fun () -> process_is_cleaned_up(P2) end),
+    receive after 1000 -> ok end,
     ?line false = erlang:read_timer(T3),
     ?line false = erlang:read_timer(T4),
     ?line Mem = mem(),
@@ -455,10 +457,18 @@ registered_process(Config) when is_list(Config) ->
     ?line ok.
 
 mem() ->
-    AA = erlang:system_info(allocated_areas),
-    {value,{bif_timer,Mem}} = lists:keysearch(bif_timer, 1, AA),
-    Mem.
-
+    TSrvs = erts_internal:get_bif_timer_servers(),
+    lists:foldl(fun (Tab, Sz) ->
+			case lists:member(ets:info(Tab, owner), TSrvs) of
+			    true ->
+				ets:info(Tab, memory) + Sz;
+			    false ->
+				Sz
+			end
+		end,
+		0,
+		ets:all())*erlang:system_info({wordsize,external}).
+					    
 process_is_cleaned_up(P) when is_pid(P) ->
     undefined == erts_debug:get_internal_state({process_status, P}).
 
diff --git a/erts/emulator/test/unique_SUITE.erl b/erts/emulator/test/unique_SUITE.erl
new file mode 100644
index 0000000000..5ad6e59272
--- /dev/null
+++ b/erts/emulator/test/unique_SUITE.erl
@@ -0,0 +1,390 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2014. All Rights Reserved.
+%% 
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%% 
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(unique_SUITE).
+
+-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]).
+-export([unique_monotonic_integer_white_box/1,
+	 unique_integer_white_box/1]).
+
+-include_lib("test_server/include/test_server.hrl").
+
+%-define(P(V), V).
+-define(P(V), print_ret_val(?FILE, ?LINE, V)).
+
+-define(PRINT(V), print_ret_val(?FILE, ?LINE, V)).
+
+
+init_per_testcase(Case, Config) ->
+    ?line Dog=test_server:timetrap(test_server:minutes(2)),
+    [{watchdog, Dog}, {testcase, Case}|Config].
+
+end_per_testcase(_, Config) ->
+    Dog=?config(watchdog, Config),
+    test_server:timetrap_cancel(Dog),
+    ok.
+
+suite() -> [{ct_hooks,[ts_install_cth]}].
+
+all() -> 
+    [unique_monotonic_integer_white_box,
+     unique_integer_white_box].
+
+groups() -> 
+    [].
+
+init_per_suite(Config) ->
+    erts_debug:set_internal_state(available_internal_state, true),
+    Config.
+
+end_per_suite(_Config) ->
+    erts_debug:set_internal_state(available_internal_state, false),
+    ok.
+
+init_per_group(_GroupName, Config) ->
+    Config.
+
+end_per_group(_GroupName, Config) ->
+    Config.
+
+%%
+%%
+%% Unique counter white box test case
+%%
+%%
+
+unique_monotonic_integer_white_box(Config) when is_list(Config) ->
+    {ok, Node} = start_node(Config),
+    TestServer = self(),
+    Success = make_ref(),
+    %% Run this in a separate node, so we don't mess up
+    %% the system when moving the strict monotonic counter
+    %% around in a non-strict monotonic way...
+    Test = spawn(Node,
+		 fun () ->
+			 unique_monotonic_integer_white_box_test(TestServer, Success)
+		 end),
+    Mon = erlang:monitor(process, Test),
+    receive
+	{'DOWN', Mon, process, Test, Error} ->
+	    ?t:fail(Error);
+	Success ->
+	    ok
+    end,
+    erlang:demonitor(Mon, [flush]),
+    stop_node(Node),
+    ok.
+
+set_unique_monotonic_integer_state(MinCounter, NextValue) ->
+    true = erts_debug:set_internal_state(unique_monotonic_integer_state,
+					 NextValue-MinCounter-1).
+    
+    
+
+unique_monotonic_integer_white_box_test(TestServer, Success) ->
+    erts_debug:set_internal_state(available_internal_state, true),
+
+    WordSize = erlang:system_info({wordsize, internal}),
+    SmallBits = WordSize*8 - 4,
+
+    MinSmall = -1*(1 bsl (SmallBits-1)),
+    MaxSmall = (1 bsl (SmallBits-1))-1,
+    %% Make sure we got small sizes correct...
+    0 = erts_debug:size(MinSmall),
+    false = 0 =:= erts_debug:size(MinSmall-1),
+    0 = erts_debug:size(MaxSmall),
+    false = 0 =:= erts_debug:size(MaxSmall+1),
+
+    ?PRINT({min_small, MinSmall}),
+    ?PRINT({max_small, MaxSmall}),
+
+    MinSint64 = -1*(1 bsl 63),
+    MaxSint64 = (1 bsl 63)-1,
+
+    ?PRINT({min_Sint64, MinSint64}),
+    ?PRINT({max_Sint64, MaxSint64}),
+
+    MinCounter = erts_debug:get_internal_state(min_unique_monotonic_integer),
+    MaxCounter = MinCounter + (1 bsl 64) - 1,
+
+    ?PRINT({min_counter, MinCounter}),
+    ?PRINT({max_counter, MaxCounter}),
+
+    case WordSize of
+	4 ->
+	    MinCounter = MinSint64;
+	8 ->
+	    MinCounter = MinSmall
+    end,
+
+    StartState = erts_debug:get_internal_state(unique_monotonic_integer_state),
+
+    %% Verify that we get expected results over all internal limits...
+
+    case MinCounter < MinSmall of
+	false ->
+	    8 = WordSize,
+	    ok;
+	true ->
+	    4 = WordSize,
+	    ?PRINT(over_min_small),
+	    set_unique_monotonic_integer_state(MinCounter, MinSmall-2),
+	    true = (?P(erlang:unique_integer([monotonic])) == MinSmall - 2),
+	    true = (?P(erlang:unique_integer([monotonic])) == MinSmall - 1),
+	    true = (?P(erlang:unique_integer([monotonic])) == MinSmall),
+	    true = (?P(erlang:unique_integer([monotonic]))  == MinSmall + 1),
+	    true = (?P(erlang:unique_integer([monotonic]))  == MinSmall + 2),
+	    garbage_collect(),
+	    ok
+    end,
+
+    ?PRINT(over_zero), %% Not really an interesting limit, but...
+    set_unique_monotonic_integer_state(MinCounter, -2),
+    true = (?P(erlang:unique_integer([monotonic])) == -2),
+    true = (?P(erlang:unique_integer([monotonic])) == -1),
+    true = (?P(erlang:unique_integer([monotonic])) == 0),
+    true = (?P(erlang:unique_integer([monotonic]))  == 1),
+    true = (?P(erlang:unique_integer([monotonic]))  == 2),
+    garbage_collect(),
+
+    ?PRINT(over_max_small),
+    set_unique_monotonic_integer_state(MinCounter, MaxSmall-2),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxSmall - 2),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxSmall - 1),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxSmall),
+    true = (?P(erlang:unique_integer([monotonic]))  == MaxSmall + 1),
+    true = (?P(erlang:unique_integer([monotonic]))  == MaxSmall + 2),
+    garbage_collect(),
+
+    case MaxCounter > MaxSint64 of
+	false ->
+	    4 = WordSize,
+	    ok;
+	true ->
+	    8 = WordSize,
+	    ?PRINT(over_max_sint64),
+	    set_unique_monotonic_integer_state(MinCounter, MaxSint64-2),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64 - 2),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64 - 1),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64 + 1),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64 + 2),
+	    garbage_collect()
+    end,
+
+    ?PRINT(over_max_min_counter),
+    set_unique_monotonic_integer_state(MinCounter, if MaxCounter == MaxSint64 ->
+							   MaxCounter-2;
+						      true ->
+							   MinCounter-3
+						   end),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxCounter - 2),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxCounter - 1),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxCounter),
+    true = (?P(erlang:unique_integer([monotonic])) == MinCounter),
+    true = (?P(erlang:unique_integer([monotonic])) == MinCounter + 1),
+    true = (?P(erlang:unique_integer([monotonic])) == MinCounter + 2),
+    garbage_collect(),
+
+    %% Restore initial state and hope we didn't mess it up for the
+    %% system...
+    true = erts_debug:set_internal_state(unique_monotonic_integer_state,
+					 StartState),
+
+    TestServer ! Success.
+
+%%
+%%
+%% Unique integer white box test case
+%%
+%%
+
+-record(uniqint_info, {min_int,
+		       max_int,
+		       max_small,
+		       schedulers,
+		       sched_bits}).
+
+unique_integer_white_box(Config) when is_list(Config) ->
+    UinqintInfo = init_uniqint_info(),
+    #uniqint_info{min_int = MinInt,
+		  max_int = MaxInt,
+		  max_small = MaxSmall} = UinqintInfo,
+    io:format("****************************************************~n", []),
+    io:format("*** Around MIN_UNIQ_INT ~p ***~n", [MinInt]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around(MinInt, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around 0 ***~n", []),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around(0, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around MAX_SMALL ~p ***~n", [MaxSmall]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around(MaxSmall, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around 2^64+MIN_UNIQ_INT ~p ***~n", [(1 bsl 64)+MinInt]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around((1 bsl 64)+MinInt, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around 2^64 ~p~n", [(1 bsl 64)]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around((1 bsl 64), UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around 2^64-MIN_UNIQ_INT ~p ***~n", [(1 bsl 64)-MinInt]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around((1 bsl 64)-MinInt, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around MAX_UNIQ_INT ~p ***~n", [MaxInt]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around(MaxInt, UinqintInfo),
+    ok.
+	
+
+%%% Internal unique_integer_white_box/1 test case
+
+calc_sched_bits(NoScheds, Shift) when NoScheds < 1 bsl Shift ->
+    Shift;
+calc_sched_bits(NoScheds, Shift) ->
+    calc_sched_bits(NoScheds, Shift+1).
+
+init_uniqint_info() ->
+    SmallBits = erlang:system_info({wordsize, internal})*8-4,
+    io:format("SmallBits=~p~n", [SmallBits]),
+    Schedulers = erlang:system_info(schedulers),
+    io:format("Schedulers=~p~n", [Schedulers]),
+    MinSmall = -1*(1 bsl (SmallBits-1)),
+    io:format("MinSmall=~p~n", [MinSmall]),
+    MaxSmall = (1 bsl (SmallBits-1))-1,
+    io:format("MaxSmall=~p~n", [MaxSmall]),
+    SchedBits = calc_sched_bits(Schedulers, 0),
+    io:format("SchedBits=~p~n", [SchedBits]),
+    MaxInt = ((((1 bsl 64) - 1) bsl SchedBits) bor Schedulers) + MinSmall,
+    io:format("MaxInt=~p~n", [MaxInt]),
+    #uniqint_info{min_int = MinSmall,
+		  max_int = MaxInt,
+		  max_small = MaxSmall,
+		  schedulers = Schedulers,
+		  sched_bits = SchedBits}.
+
+valid_uniqint(Int, #uniqint_info{min_int = MinInt} = UinqintInfo) when Int < MinInt ->
+    valid_uniqint(MinInt, UinqintInfo);
+valid_uniqint(Int, #uniqint_info{min_int = MinInt,
+				 sched_bits = SchedBits,
+				 schedulers = Scheds}) ->
+    Int1 = Int - MinInt,
+    {Inc, ThreadNo} = case Int1 band ((1 bsl SchedBits) - 1) of
+			  TN when TN > Scheds ->
+			      {1, Scheds};
+			  TN ->
+			      {0, TN}
+		      end,
+    Counter = ((Int1 bsr SchedBits) + Inc) rem (1 bsl 64),
+    ((Counter bsl SchedBits) bor ThreadNo) + MinInt.
+
+smaller_valid_uniqint(Int, UinqintInfo) ->
+    Cand = Int-1,
+    case valid_uniqint(Cand, UinqintInfo) of
+	RI when RI < Int ->
+	    RI;
+	_ ->
+	    smaller_valid_uniqint(Cand, UinqintInfo)
+    end.
+
+int32_to_bigendian_list(Int) ->
+    0 = Int bsr 32,
+    [(Int bsr 24) band 16#ff,
+     (Int bsr 16) band 16#ff,
+     (Int bsr 8) band 16#ff,
+     Int band 16#ff].
+
+mk_uniqint(Int, #uniqint_info {min_int = MinInt,
+			       sched_bits = SchedBits} = _UinqintInfo) ->
+    Int1 = Int - MinInt,
+    ThrId = Int1 band ((1 bsl SchedBits) - 1),
+    Value = (Int1 bsr SchedBits) band ((1 bsl 64) - 1),
+    0 = Int1 bsr (SchedBits + 64),
+    NodeName = atom_to_list(node()),
+    Make = {make_unique_integer, ThrId, Value},
+    %% erlang:display(Make),
+    Res = erts_debug:get_internal_state(Make),
+    %% erlang:display({uniq_int, Res}),
+    Res.
+
+check_uniqint(Int, UinqintInfo) ->
+    UniqInt = mk_uniqint(Int, UinqintInfo),
+    io:format("UniqInt=~p ", [UniqInt]),
+    case UniqInt =:= Int of
+	true ->
+	    io:format("OK~n~n", []);
+	false ->
+	    io:format("result UniqInt=~p FAILED~n", [UniqInt]),
+	    exit(badres)
+    end.
+
+check_unique_integer_around(Int, #uniqint_info{min_int = MinInt,
+					       max_int = MaxInt} = UinqintInfo) ->
+    {Start, End} = case {Int =< MinInt+100, Int >= MaxInt-100} of
+		       {true, false} ->
+			   {MinInt, MinInt+100};
+		       {false, false} ->
+			   {smaller_valid_uniqint(Int-100, UinqintInfo),
+			    valid_uniqint(Int+100, UinqintInfo)};
+		       {false, true} ->
+			   {MaxInt-100, MaxInt}
+		   end,
+    lists:foldl(fun (I, OldRefInt) ->
+			RefInt = valid_uniqint(I, UinqintInfo),
+			case OldRefInt =:= RefInt of
+			    true ->
+				ok;
+			    false ->
+				check_uniqint(RefInt, UinqintInfo)
+			end,
+			RefInt
+		end,
+		none,
+		lists:seq(Start, End)).
+
+
+%% helpers
+
+print_ret_val(File, Line, Value) ->    
+    io:format("~s:~p: ~p~n", [File, Line, Value]),
+    Value.
+
+start_node(Config) ->
+    start_node(Config, []).
+start_node(Config, Opts) when is_list(Config), is_list(Opts) ->
+    ?line Pa = filename:dirname(code:which(?MODULE)),
+    ?line A = erlang:monotonic_time(1) + erlang:time_offset(1),
+    ?line B = erlang:unique_integer([positive]),
+    ?line Name = list_to_atom(atom_to_list(?MODULE)
+			      ++ "-"
+			      ++ atom_to_list(?config(testcase, Config))
+			      ++ "-"
+			      ++ integer_to_list(A)
+			      ++ "-"
+			      ++ integer_to_list(B)),
+    ?line ?t:start_node(Name, slave, [{args, Opts++" -pa "++Pa}]).
+
+stop_node(Node) ->
+    ?t:stop_node(Node).
author	Rickard Green <[email protected]>	2015-03-20 21:29:30 +0100
committer	Rickard Green <[email protected]>	2015-03-20 21:29:30 +0100
commit	f4e3cd1c970cfc5ad54f2ed64832d05749c305d4 (patch)
tree	a008c88d68c801ac290373920435d952b027905c /erts/emulator
parent	c0d3f4cbb5775a9214366e0d9cb76847d69c3459 (diff)
parent	e7a713167e3390bfa7d7ada2eafe5fe16f185405 (diff)
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