Merge branch 'sverker/async-auto-connect/OTP-14370'

* sverker/async-auto-connect/OTP-14370: (37 commits)
  Move new|abort_connection_id to erts_internal
  Refactor erts_dsig_prepare argument dep(p)
  Cleanup net_kernel
  Improve connection aborting
  Abort all pending connections if net_kernel terminates
  erts: Put pending DistrEntry in separate list
  Refactor auto_connect into an outline function
  Remove unused ERTS_DSP_RWLOCK
  fix erlang specs and preloaded
  erts: Keep magic ref to DistEntry in net_kernel
  Allow DistEntries in ETS
  Remove faulty assert
  erts: Transcode tuple fallbacks
  erts: Ensure enc_term_int() always do progress
  erl_interface: Add tuple fallback tests
  erl_interface: Refactor ei_accept_SUITE
  Add optimistic DFLAG_DIST_HOPEFULLY for pending connections
  erts: Fix auto-connect toward erl_interface/jinterface
  erts: Let send(_,_,[noconnect]) enqueue msg on pending connection.
  Remove obsolete erlang:dgroup_leader
  ...

23 files changed, 1445 insertions, 926 deletions

diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index fc55b687d4..75a70c3716 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -108,6 +108,7 @@ atom asynchronous
 atom atom
 atom atom_used
 atom attributes
+atom auto_connect
 atom await_microstate_accounting_modifications
 atom await_port_send_result
 atom await_proc_exit
@@ -198,9 +199,7 @@ atom debug_flags
 atom decimals
 atom default
 atom delay_trap
-atom dexit
 atom depth
-atom dgroup_leader
 atom dictionary
 atom dirty_bif_exception
 atom dirty_bif_result
@@ -221,7 +220,6 @@ atom dist_ctrl_put_data
 atom dist_data
 atom Div='/'
 atom div
-atom dlink
 atom dmonitor_node
 atom dmonitor_p
 atom DollarDollar='$$'
@@ -230,9 +228,7 @@ atom dollar_endonly
 atom dotall
 atom driver
 atom driver_options
-atom dsend
 atom dsend_continue_trap
-atom dunlink
 atom duplicate_bag
 atom duplicated
 atom dupnames
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 4b11884f38..50699eac31 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -227,17 +227,40 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
 		goto res_no_proc;
 	    }
 
-	    code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_DSP_RLOCK, 0);
+	    code = erts_dsig_prepare(&dsd, dep, BIF_P,
+				     (ERTS_PROC_LOCK_MAIN | ERTS_PROC_LOCK_LINK),
+				     ERTS_DSP_RLOCK, 0, 1);
 	    switch (code) {
 	    case ERTS_DSIG_PREP_NOT_ALIVE:
-		/* Let the dlink trap handle it */
-	    case ERTS_DSIG_PREP_NOT_CONNECTED:
-		erts_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
-		BIF_TRAP1(dlink_trap, BIF_P, BIF_ARG_1);
-
+	    case ERTS_DSIG_PREP_NOT_CONNECTED: {
+		ErtsProcLocks locks = ERTS_PROC_LOCK_MAIN | ERTS_PROC_LOCK_LINK;
+		erts_aint32_t state;
+		erts_proc_lock(BIF_P, (ERTS_PROC_LOCKS_ALL & ~locks));
+		locks = ERTS_PROC_LOCKS_ALL;
+		erts_send_exit_signal(BIF_P, BIF_ARG_1, BIF_P, &locks,
+				      am_noconnection, NIL, NULL, 0);
+		erts_proc_unlock(BIF_P, locks & ERTS_PROC_LOCKS_ALL_MINOR);
+
+		/*
+		 * Copy-paste from old dist_exit_3, not sure if we really
+		 * need erts_handle_pending_exit when exit_2 does not.
+		 */
+		state = erts_atomic32_read_acqb(&BIF_P->state);
+		if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT)) {
+#ifdef ERTS_SMP
+		    if (state & ERTS_PSFLG_PENDING_EXIT)
+			erts_handle_pending_exit(BIF_P, ERTS_PROC_LOCK_MAIN);
+#endif
+		    ERTS_BIF_EXITED(BIF_P);
+		}
+		BIF_RET(am_true);
+	    }
+            case ERTS_DSIG_PREP_PENDING:
 	    case ERTS_DSIG_PREP_CONNECTED:
-		/* We are connected. Setup link and send link signal */
-
+                /*
+                 * We have (pending) connection.
+                 * Setup link and enqueue link signal.
+                 */
 		erts_de_links_lock(dep);
 
 		erts_add_link(&ERTS_P_LINKS(BIF_P), LINK_PID, BIF_ARG_1);
@@ -256,8 +279,7 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
 		    ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
 		BIF_RET(am_true);
 	    default:
-		ASSERT(! "Invalid dsig prepare result");
-		BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
+		ERTS_ASSERT(! "Invalid dsig prepare result");
 	    }
 	}
     }
@@ -292,7 +314,8 @@ remote_demonitor(Process *c_p, DistEntry *dep, Eterm ref, Eterm to)
     ERTS_LC_ASSERT((ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK)
 		       == erts_proc_lc_my_proc_locks(c_p));
 
-    code = erts_dsig_prepare(&dsd, dep, c_p, ERTS_DSP_RLOCK, 0);
+    code = erts_dsig_prepare(&dsd, dep, c_p, ERTS_PROC_LOCK_MAIN,
+			     ERTS_DSP_RLOCK, 0, 0);
     switch (code) {
     case ERTS_DSIG_PREP_NOT_ALIVE:
     case ERTS_DSIG_PREP_NOT_CONNECTED:
@@ -313,6 +336,7 @@ remote_demonitor(Process *c_p, DistEntry *dep, Eterm ref, Eterm to)
         res = am_true;
 	break;
 
+    case ERTS_DSIG_PREP_PENDING:
     case ERTS_DSIG_PREP_CONNECTED:
 
 	erts_de_links_lock(dep);
@@ -347,8 +371,7 @@ remote_demonitor(Process *c_p, DistEntry *dep, Eterm ref, Eterm to)
 	}
 	break;
     default:
-	ASSERT(! "Invalid dsig prepare result");
-        return am_internal_error;
+	ERTS_ASSERT(! "Invalid dsig prepare result");
     }
 
 
@@ -767,23 +790,20 @@ remote_monitor(Process *p, Eterm bifarg1, Eterm bifarg2,
     BIF_RETTYPE ret;
     int code;
 
+    ASSERT(dep);
     erts_proc_lock(p, ERTS_PROC_LOCK_LINK);
-    code = erts_dsig_prepare(&dsd, dep, p, ERTS_DSP_RLOCK, 0);
+    code = erts_dsig_prepare(&dsd, dep,
+			     p, (ERTS_PROC_LOCK_MAIN | ERTS_PROC_LOCK_LINK),
+			     ERTS_DSP_RLOCK, 0, 1);
     switch (code) {
     case ERTS_DSIG_PREP_NOT_ALIVE:
-	/* Let the dmonitor_p trap handle it */
     case ERTS_DSIG_PREP_NOT_CONNECTED:
 	erts_proc_unlock(p, ERTS_PROC_LOCK_LINK);
 	ERTS_BIF_PREP_TRAP2(ret, dmonitor_p_trap, p, bifarg1, bifarg2);
 	break;
+    case ERTS_DSIG_PREP_PENDING:
     case ERTS_DSIG_PREP_CONNECTED:
-	if (!(dep->flags & DFLAG_DIST_MONITOR)
-	    || (byname && !(dep->flags & DFLAG_DIST_MONITOR_NAME))) {
-	    erts_de_runlock(dep);
-	    erts_proc_unlock(p, ERTS_PROC_LOCK_LINK);
-	    ERTS_BIF_PREP_ERROR(ret, p, BADARG);
-	}
-	else {
+	{
 	    Eterm p_trgt, p_name, d_name, mon_ref;
 
 	    mon_ref = erts_make_ref(p);
@@ -818,9 +838,7 @@ remote_monitor(Process *p, Eterm bifarg1, Eterm bifarg2,
 	}
 	break;
     default:
-	ASSERT(! "Invalid dsig prepare result");
-	ERTS_BIF_PREP_ERROR(ret, p, EXC_INTERNAL_ERROR);
-	break;
+	ERTS_ASSERT(! "Invalid dsig prepare result");
     }
 
     BIF_RET(ret);
@@ -888,17 +906,17 @@ local_port:
 	if (!erts_is_alive && remote_node != am_Noname) {
             goto badarg; /* Remote monitor from (this) undistributed node */
 	}
-	dep = erts_sysname_to_connected_dist_entry(remote_node);
+	dep = erts_find_or_insert_dist_entry(remote_node);
 	if (dep == erts_this_dist_entry) {
             ret = local_name_monitor(BIF_P, BIF_ARG_1, name);
 	} else {
 	    ret = remote_monitor(BIF_P, BIF_ARG_1, BIF_ARG_2, dep, name, 1);
 	}
+	erts_deref_dist_entry(dep);
     } else {
 badarg:
 	ERTS_BIF_PREP_ERROR(ret, BIF_P, BADARG);
     }
-
     return ret;
 }
 
@@ -1158,21 +1176,14 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
 	    BIF_RET(am_true);
 	}
 
-	code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_DSP_NO_LOCK, 0);
+	code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_PROC_LOCK_MAIN,
+				 ERTS_DSP_NO_LOCK, 0, 0);
 	switch (code) {
 	case ERTS_DSIG_PREP_NOT_ALIVE:
 	case ERTS_DSIG_PREP_NOT_CONNECTED:
-#if 1
 	    BIF_RET(am_true);
-#else
-	    /*
-	     * This is how we used to do it, but the link is obviously not
-	     * active, so I see no point in setting up a connection.
-	     * /Rickard
-	     */
-	    BIF_TRAP1(dunlink_trap, BIF_P, BIF_ARG_1);
-#endif
 
+	case ERTS_DSIG_PREP_PENDING:
 	case ERTS_DSIG_PREP_CONNECTED:
 	    erts_remove_dist_link(&dld, BIF_P->common.id, BIF_ARG_1, dep);
 	    code = erts_dsig_send_unlink(&dsd, BIF_P->common.id, BIF_ARG_1);
@@ -1545,22 +1556,24 @@ BIF_RETTYPE exit_2(BIF_ALIST_2)
 	 DistEntry *dep;
 
 	 dep = external_pid_dist_entry(BIF_ARG_1);
+	 ERTS_ASSERT(dep);
 	 if(dep == erts_this_dist_entry)
 	     BIF_RET(am_true);
 
-	 code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_DSP_NO_LOCK, 0);
+	 code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_PROC_LOCK_MAIN,
+				  ERTS_DSP_NO_LOCK, 0, 1);
 	 switch (code) {
 	 case ERTS_DSIG_PREP_NOT_ALIVE:
 	 case ERTS_DSIG_PREP_NOT_CONNECTED:
-	     BIF_TRAP2(dexit_trap, BIF_P, BIF_ARG_1, BIF_ARG_2);
+	     BIF_RET(am_true);
+	 case ERTS_DSIG_PREP_PENDING:
 	 case ERTS_DSIG_PREP_CONNECTED:
 	     code = erts_dsig_send_exit2(&dsd, BIF_P->common.id, BIF_ARG_1, BIF_ARG_2);
 	     if (code == ERTS_DSIG_SEND_YIELD)
 		 ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
 	     BIF_RET(am_true);
 	 default:
-	     ASSERT(! "Invalid dsig prepare result");
-	     BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
+	     ERTS_ASSERT(! "Invalid dsig prepare result");
 	 }
      }
      else if (is_not_internal_pid(BIF_ARG_1)) {
@@ -1964,7 +1977,7 @@ ebif_bang_2(BIF_ALIST_2)
  * Send a message to Process, Port or Registered Process.
  * Returns non-negative reduction bump or negative result code.
  */
-#define SEND_TRAP		(-1)
+#define SEND_NOCONNECT		(-1)
 #define SEND_YIELD		(-2)
 #define SEND_YIELD_RETURN	(-3)
 #define SEND_BADARG		(-4)
@@ -1980,20 +1993,22 @@ static Sint remote_send(Process *p, DistEntry *dep,
 {
     Sint res;
     int code;
-
     ASSERT(is_atom(to) || is_external_pid(to));
 
     ctx->dep = dep;
-    code = erts_dsig_prepare(&ctx->dsd, dep, p, ERTS_DSP_NO_LOCK, !ctx->suspend);
+    code = erts_dsig_prepare(&ctx->dsd, dep, p, ERTS_PROC_LOCK_MAIN,
+			     ERTS_DSP_NO_LOCK,
+			     !ctx->suspend, ctx->connect);
     switch (code) {
     case ERTS_DSIG_PREP_NOT_ALIVE:
     case ERTS_DSIG_PREP_NOT_CONNECTED:
-	res = SEND_TRAP;
+	res = SEND_NOCONNECT;
 	break;
     case ERTS_DSIG_PREP_WOULD_SUSPEND:
 	ASSERT(!ctx->suspend);
 	res = SEND_YIELD;
 	break;
+    case ERTS_DSIG_PREP_PENDING:
     case ERTS_DSIG_PREP_CONNECTED: {
 
 	if (is_atom(to))
@@ -2170,6 +2185,7 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm *refp, ErtsSendContext *ctx)
 	}
 	return ret_val;
     } else if (is_tuple(to)) { /* Remote send */
+        int deref_dep = 0;
 	int ret;
 	tp = tuple_val(to);
 	if (*tp != make_arityval(2))
@@ -2177,11 +2193,10 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm *refp, ErtsSendContext *ctx)
 	if (is_not_atom(tp[1]) || is_not_atom(tp[2]))
 	    return SEND_BADARG;
 	
-	/* sysname_to_connected_dist_entry will return NULL if there
-	   is no dist_entry or the dist_entry has no port,
+	/* erts_find_dist_entry will return NULL if there is no dist_entry
 	   but remote_send() will handle that. */
 
-	dep = erts_sysname_to_connected_dist_entry(tp[2]);
+	dep = erts_find_dist_entry(tp[2]);
 
 	if (dep == erts_this_dist_entry) {
 	    Eterm id;
@@ -2205,13 +2220,20 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm *refp, ErtsSendContext *ctx)
 	    }
 	    return 0;
 	}
+        if (dep == NULL) {
+            dep = erts_find_or_insert_dist_entry(tp[2]);
+            ASSERT(dep != erts_this_dist_entry);
+            deref_dep = 1;
+        }
+	ctx->dsd.node = tp[2];
 
 	ret = remote_send(p, dep, tp[1], to, msg, ctx);
 	if (ret == SEND_YIELD_CONTINUE) {
-            if (dep)
-                erts_ref_dist_entry(dep);
-	    ctx->dep_to_deref = dep;
+            erts_ref_dist_entry(ctx->dep);
+            ctx->deref_dep = 1;
 	}
+        if (deref_dep)
+            erts_deref_dist_entry(dep);
 	return ret;
     } else {
 	if (IS_TRACED_FL(p, F_TRACE_SEND))
@@ -2251,7 +2273,6 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
     Eterm msg = BIF_ARG_2;
     Eterm opts = BIF_ARG_3;
 
-    int connect = !0;
     Eterm l = opts;
     Sint result;
 
@@ -2262,14 +2283,15 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
     UseTmpHeap(sizeof(ErtsSendContext)/sizeof(Eterm), BIF_P);
 
     ctx->suspend = !0;
-    ctx->dep_to_deref = NULL;
+    ctx->connect = !0;
+    ctx->deref_dep = 0;
     ctx->return_term = am_ok;
     ctx->dss.reds = (Sint) (ERTS_BIF_REDS_LEFT(p) * TERM_TO_BINARY_LOOP_FACTOR);
     ctx->dss.phase = ERTS_DSIG_SEND_PHASE_INIT;
 
     while (is_list(l)) {
 	if (CAR(list_val(l)) == am_noconnect) {
-	    connect = 0;
+	    ctx->connect = 0;
 	} else if (CAR(list_val(l)) == am_nosuspend) {
 	    ctx->suspend = 0;
 	} else {
@@ -2306,9 +2328,9 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
 	    goto yield_return;
 	ERTS_BIF_PREP_RET(retval, am_ok);
 	break;
-    case SEND_TRAP:
-	if (connect) {
-	    ERTS_BIF_PREP_TRAP3(retval, dsend3_trap, p, to, msg, opts);
+    case SEND_NOCONNECT:
+	if (ctx->connect) {
+	    ERTS_BIF_PREP_RET(retval, am_ok);
 	} else {
 	    ERTS_BIF_PREP_RET(retval, am_noconnect);
 	}
@@ -2412,7 +2434,8 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg)
     ref = NIL;
 #endif
     ctx->suspend = !0;
-    ctx->dep_to_deref = NULL;
+    ctx->connect = !0;
+    ctx->deref_dep = 0;
     ctx->return_term = msg;
     ctx->dss.reds = (Sint) (ERTS_BIF_REDS_LEFT(p) * TERM_TO_BINARY_LOOP_FACTOR);
     ctx->dss.phase = ERTS_DSIG_SEND_PHASE_INIT;
@@ -2436,8 +2459,8 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg)
 	    goto yield_return;
 	ERTS_BIF_PREP_RET(retval, msg);
 	break;
-    case SEND_TRAP:
-	ERTS_BIF_PREP_TRAP2(retval, dsend2_trap, p, to, msg);
+    case SEND_NOCONNECT:
+	ERTS_BIF_PREP_RET(retval, msg);
 	break;
     case SEND_YIELD:
 	ERTS_BIF_PREP_YIELD2(retval, bif_export[BIF_send_2], p, to, msg);
@@ -4384,23 +4407,24 @@ BIF_RETTYPE group_leader_2(BIF_ALIST_2)
 	int code;
 	ErtsDSigData dsd;
 	dep = external_pid_dist_entry(BIF_ARG_2);
+	ERTS_ASSERT(dep);
 	if(dep == erts_this_dist_entry)
 	    BIF_ERROR(BIF_P, BADARG);
 
-	code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_DSP_NO_LOCK, 0);
+	code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_PROC_LOCK_MAIN,
+				 ERTS_DSP_NO_LOCK, 0, 1);
 	switch (code) {
 	case ERTS_DSIG_PREP_NOT_ALIVE:
-	    BIF_RET(am_true);
 	case ERTS_DSIG_PREP_NOT_CONNECTED:
-	    BIF_TRAP2(dgroup_leader_trap, BIF_P, BIF_ARG_1, BIF_ARG_2);
+	    BIF_RET(am_true);
+	case ERTS_DSIG_PREP_PENDING:
 	case ERTS_DSIG_PREP_CONNECTED:
 	    code = erts_dsig_send_group_leader(&dsd, BIF_ARG_1, BIF_ARG_2);
 	    if (code == ERTS_DSIG_SEND_YIELD)
 		ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
 	    BIF_RET(am_true);
 	default:
-	    ASSERT(! "Invalid dsig prepare result");
-	    BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
+	    ERTS_ASSERT(! "Invalid dsig prepare result");
 	}
     }
     else if (is_internal_pid(BIF_ARG_2)) {
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index f7b4451890..f739f414de 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -153,14 +153,12 @@ bif erlang:whereis/1
 bif erlang:spawn_opt/1
 bif erlang:setnode/2
 bif erlang:setnode/3
-bif erlang:dist_exit/3
 bif erlang:dist_get_stat/1
 bif erlang:dist_ctrl_input_handler/2
 bif erlang:dist_ctrl_put_data/2
 bif erlang:dist_ctrl_get_data/1
 bif erlang:dist_ctrl_get_data_notification/1
 
-
 # Static native functions in erts_internal
 bif erts_internal:port_info/1
 bif erts_internal:port_info/2
@@ -691,3 +689,11 @@ bif erts_internal:maps_to_list/2
 #
 
 bif erlang:iolist_to_iovec/1
+
+#
+# New in 21.0
+#
+
+bif erts_internal:new_connection/1
+bif erts_internal:abort_connection/2
+
diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index e6e4221c08..8593ad867a 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -103,21 +103,12 @@ dist_msg_dbg(ErtsDistExternal *edep, char *what, byte *buf, int sz)
 
 
 
-#define PASS_THROUGH 'p'        /* This code should go */
-
 int erts_is_alive; /* System must be blocked on change */
 int erts_dist_buf_busy_limit;
 
 
 /* distribution trap functions */
-Export* dsend2_trap = NULL;
-Export* dsend3_trap = NULL;
-/*Export* dsend_nosuspend_trap = NULL;*/
-Export* dlink_trap = NULL;
-Export* dunlink_trap = NULL;
 Export* dmonitor_node_trap = NULL;
-Export* dgroup_leader_trap = NULL;
-Export* dexit_trap = NULL;
 Export* dmonitor_p_trap = NULL;
 
 /* local variables */
@@ -129,6 +120,7 @@ static void clear_dist_entry(DistEntry*);
 static int dsig_send_ctl(ErtsDSigData* dsdp, Eterm ctl, int force_busy);
 static void send_nodes_mon_msgs(Process *, Eterm, Eterm, Eterm, Eterm);
 static void init_nodes_monitors(void);
+static Sint abort_connection(DistEntry* dep, Uint32 conn_id);
 
 static erts_atomic_t no_caches;
 static erts_atomic_t no_nodes;
@@ -486,41 +478,55 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
 
     if (dep == erts_this_dist_entry) {  /* Net kernel has died (clean up!!) */
 	DistEntry *tdep;
-	int no_dist_ctrl = 0;
+	int no_dist_ctrl;
+        int no_pending;
 	Eterm nd_reason = (reason == am_no_network
 			   ? am_no_network
 			   : am_net_kernel_terminated);
+        int i = 0;
+        Eterm *dist_ctrl;
+        DistEntry** pending;
+
+        ERTS_UNDEF(dist_ctrl, NULL);
+        ERTS_UNDEF(pending, NULL);
+
 	erts_rwmtx_rlock(&erts_dist_table_rwmtx);
 
-	for (tdep = erts_hidden_dist_entries; tdep; tdep = tdep->next)
-	    no_dist_ctrl++;
-	for (tdep = erts_visible_dist_entries; tdep; tdep = tdep->next)
-	    no_dist_ctrl++;
+        no_dist_ctrl = (erts_no_of_hidden_dist_entries +
+                        erts_no_of_visible_dist_entries);
+        no_pending = erts_no_of_pending_dist_entries;
 
 	/* KILL all port controllers */
-	if (no_dist_ctrl == 0)
-	    erts_rwmtx_runlock(&erts_dist_table_rwmtx);
-	else {
-	    Eterm def_buf[128];
-	    int i = 0;
-	    Eterm *dist_ctrl;
-
-	    if (no_dist_ctrl <= sizeof(def_buf)/sizeof(def_buf[0]))
-		dist_ctrl = &def_buf[0];
-	    else
-		dist_ctrl = erts_alloc(ERTS_ALC_T_TMP,
-				       sizeof(Eterm)*no_dist_ctrl);
+	if (no_dist_ctrl) {
+            dist_ctrl = erts_alloc(ERTS_ALC_T_TMP,
+                                   sizeof(Eterm)*no_dist_ctrl);
 	    for (tdep = erts_hidden_dist_entries; tdep; tdep = tdep->next) {
 		ASSERT(is_internal_port(tdep->cid) || is_internal_pid(tdep->cid));
+                ASSERT(i < no_dist_ctrl);
 		dist_ctrl[i++] = tdep->cid;
 	    }
 	    for (tdep = erts_visible_dist_entries; tdep; tdep = tdep->next) {
 		ASSERT(is_internal_port(tdep->cid) || is_internal_pid(tdep->cid));
+                ASSERT(i < no_dist_ctrl);
 		dist_ctrl[i++] = tdep->cid;
 	    }
-	    erts_rwmtx_runlock(&erts_dist_table_rwmtx);
+            ASSERT(i == no_dist_ctrl);
+        }
+        if (no_pending) {
+            pending = erts_alloc(ERTS_ALC_T_TMP, sizeof(DistEntry*)*no_pending);
+            i = 0;
+            for (tdep = erts_pending_dist_entries; tdep; tdep = tdep->next) {
+                ASSERT(is_nil(tdep->cid));
+                ASSERT(i < no_pending);
+                pending[i++] = tdep;
+                erts_ref_dist_entry(tdep);
+            }
+            ASSERT(i == no_pending);
+        }
+        erts_rwmtx_runlock(&erts_dist_table_rwmtx);
 
-	    for (i = 0; i < no_dist_ctrl; i++) {
+        if (no_dist_ctrl) {
+            for (i = 0; i < no_dist_ctrl; i++) {
                 if (is_internal_pid(dist_ctrl[i]))
                     schedule_kill_dist_ctrl_proc(dist_ctrl[i]);
                 else {
@@ -534,11 +540,18 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
                                        prt, dist_ctrl[i], nd_reason, NULL);
                     }
                 }
-	    }
+            }
+            erts_free(ERTS_ALC_T_TMP, dist_ctrl);
+        }
+
+        if (no_pending) {
+            for (i = 0; i < no_pending; i++) {
+                abort_connection(pending[i], pending[i]->connection_id);
+                erts_deref_dist_entry(pending[i]);
+            }
+            erts_free(ERTS_ALC_T_TMP, pending);
+        }
 
-	    if (dist_ctrl != &def_buf[0])
-		erts_free(ERTS_ALC_T_TMP, dist_ctrl);
-	}
 
 	/*
 	 * When last dist ctrl exits, node will be taken
@@ -615,7 +628,6 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
 			    reason == am_normal ? am_connection_closed : reason);
 
 	clear_dist_entry(dep);
-
     }
 
     dec_no_nodes();
@@ -640,14 +652,7 @@ void init_dist(void)
     erts_atomic_init_nob(&no_caches, 0);
 
     /* Lookup/Install all references to trap functions */
-    dsend2_trap = trap_function(am_dsend,2);
-    dsend3_trap = trap_function(am_dsend,3);
-    /*    dsend_nosuspend_trap = trap_function(am_dsend_nosuspend,2);*/
-    dlink_trap = trap_function(am_dlink,1);
-    dunlink_trap = trap_function(am_dunlink,1);
     dmonitor_node_trap = trap_function(am_dmonitor_node,3);
-    dgroup_leader_trap = trap_function(am_dgroup_leader,2);
-    dexit_trap = trap_function(am_dexit, 2);
     dmonitor_p_trap = trap_function(am_dmonitor_p, 2);
     dist_ctrl_put_data_trap = erts_export_put(am_erts_internal,
                                               am_dist_ctrl_put_data,
@@ -666,6 +671,7 @@ alloc_dist_obuf(Uint size)
     obuf = (ErtsDistOutputBuf *) &bin->orig_bytes[0];
 #ifdef DEBUG
     obuf->dbg_pattern = ERTS_DIST_OUTPUT_BUF_DBG_PATTERN;
+    obuf->alloc_endp = obuf->data + size;
     ASSERT(bin == ErtsDistOutputBuf2Binary(obuf));
 #endif
     return obuf;
@@ -686,31 +692,11 @@ size_obuf(ErtsDistOutputBuf *obuf)
     return bin->orig_size;
 }
 
-static void clear_dist_entry(DistEntry *dep)
+static ErtsDistOutputBuf* clear_de_out_queues(DistEntry* dep)
 {
-    Sint obufsize = 0;
-    ErtsAtomCache *cache;
-    ErtsProcList *suspendees;
     ErtsDistOutputBuf *obuf;
 
-    erts_de_rwlock(dep);
-    erts_atomic_set_nob(&dep->input_handler,
-                        (erts_aint_t) NIL);
-    cache = dep->cache;
-    dep->cache = NULL;
-
-#ifdef DEBUG
-    erts_de_links_lock(dep);
-    ASSERT(!dep->nlinks);
-    ASSERT(!dep->node_links);
-    ASSERT(!dep->monitors);
-    erts_de_links_unlock(dep);
-#endif
-
-    erts_mtx_lock(&dep->qlock);
-
-    erts_atomic64_set_nob(&dep->in, 0);
-    erts_atomic64_set_nob(&dep->out, 0);
+    ERTS_LC_ASSERT(erts_lc_mtx_is_locked(&dep->qlock));
 
     if (!dep->out_queue.last)
 	obuf = dep->finalized_out_queue.first;
@@ -730,17 +716,13 @@ static void clear_dist_entry(DistEntry *dep)
     dep->tmp_out_queue.last = NULL;
     dep->finalized_out_queue.first = NULL;
     dep->finalized_out_queue.last = NULL;
-    dep->status = 0;
-    suspendees = get_suspended_on_de(dep, ERTS_DE_QFLGS_ALL);
 
-    erts_mtx_unlock(&dep->qlock);
-    erts_atomic_set_nob(&dep->dist_cmd_scheduled, 0);
-    dep->send = NULL;
-    erts_de_rwunlock(dep);
-
-    erts_resume_processes(suspendees);
+    return obuf;
+}
 
-    delete_cache(cache);
+static void free_de_out_queues(DistEntry* dep, ErtsDistOutputBuf *obuf)
+{
+    Sint obufsize = 0;
 
     while (obuf) {
 	ErtsDistOutputBuf *fobuf;
@@ -752,13 +734,56 @@ static void clear_dist_entry(DistEntry *dep)
 
     if (obufsize) {
 	erts_mtx_lock(&dep->qlock);
-	ASSERT(erts_atomic_read_nob(&dep->qsize) >= obufsize);
+        ASSERT(erts_atomic_read_nob(&dep->qsize) >= obufsize);
         erts_atomic_add_nob(&dep->qsize,
                             (erts_aint_t) -obufsize);
 	erts_mtx_unlock(&dep->qlock);
     }
 }
 
+static void clear_dist_entry(DistEntry *dep)
+{
+    ErtsAtomCache *cache;
+    ErtsProcList *suspendees;
+    ErtsDistOutputBuf *obuf;
+
+    erts_de_rwlock(dep);
+    erts_atomic_set_nob(&dep->input_handler,
+                        (erts_aint_t) NIL);
+    cache = dep->cache;
+    dep->cache = NULL;
+
+#ifdef DEBUG
+    erts_de_links_lock(dep);
+    ASSERT(!dep->nlinks);
+    ASSERT(!dep->node_links);
+    ASSERT(!dep->monitors);
+    erts_de_links_unlock(dep);
+#endif
+
+    erts_mtx_lock(&dep->qlock);
+
+    erts_atomic64_set_nob(&dep->in, 0);
+    erts_atomic64_set_nob(&dep->out, 0);
+
+    obuf = clear_de_out_queues(dep);
+    dep->status = 0;
+    suspendees = get_suspended_on_de(dep, ERTS_DE_QFLGS_ALL);
+
+    erts_mtx_unlock(&dep->qlock);
+    erts_atomic_set_nob(&dep->dist_cmd_scheduled, 0);
+    dep->send = NULL;
+    erts_de_rwunlock(dep);
+
+    erts_resume_processes(suspendees);
+
+    delete_cache(cache);
+
+    free_de_out_queues(dep, obuf);
+    if (dep->transcode_ctx)
+        transcode_free_ctx(dep);
+}
+
 int erts_dsend_context_dtor(Binary* ctx_bin)
 {
     ErtsSendContext* ctx = ERTS_MAGIC_BIN_DATA(ctx_bin);
@@ -774,8 +799,8 @@ int erts_dsend_context_dtor(Binary* ctx_bin)
     if (ctx->dss.phase >= ERTS_DSIG_SEND_PHASE_ALLOC && ctx->dss.obuf) {
 	free_dist_obuf(ctx->dss.obuf);
     }
-    if (ctx->dep_to_deref)
-	erts_deref_dist_entry(ctx->dep_to_deref);
+    if (ctx->deref_dep)
+	erts_deref_dist_entry(ctx->dep);
 
     return 1;
 }
@@ -1326,7 +1351,7 @@ int erts_net_message(Port *prt,
 	    /* This is tricky (we MUST force a distributed send) */
 	    ErtsDSigData dsd;
 	    int code;
-	    code = erts_dsig_prepare(&dsd, dep, NULL, ERTS_DSP_NO_LOCK, 0);
+	    code = erts_dsig_prepare(&dsd, dep, NULL, 0, ERTS_DSP_NO_LOCK, 0, 0);
 	    if (code == ERTS_DSIG_PREP_CONNECTED) {
 		code = erts_dsig_send_exit(&dsd, to, from, am_noproc);
 		ASSERT(code == ERTS_DSIG_SEND_OK);
@@ -1418,7 +1443,7 @@ int erts_net_message(Port *prt,
 	if (!rp) {
 	    ErtsDSigData dsd;
 	    int code;
-	    code = erts_dsig_prepare(&dsd, dep, NULL, ERTS_DSP_NO_LOCK, 0);
+	    code = erts_dsig_prepare(&dsd, dep, NULL, 0, ERTS_DSP_NO_LOCK, 0, 0);
 	    if (code == ERTS_DSIG_PREP_CONNECTED) {
 		code = erts_dsig_send_m_exit(&dsd, watcher, watched, ref,
 					     am_noproc);
@@ -1881,33 +1906,32 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
 
 	    if (ctx->flags & DFLAG_DIST_HDR_ATOM_CACHE) {
 		ctx->acmp = erts_get_atom_cache_map(ctx->c_p);
-		ctx->pass_through_size = 0;
+		ctx->max_finalize_prepend = 0;
 	    }
 	    else {
 		ctx->acmp = NULL;
-		ctx->pass_through_size = 1;
+		ctx->max_finalize_prepend = 3;
 	    }
 
     #ifdef ERTS_DIST_MSG_DBG
-	    erts_fprintf(stderr, ">>%s CTL: %T\n", ctx->pass_through_size ? "P" : " ", ctx->ctl);
-        if (is_value(ctx->msg))
-            erts_fprintf(stderr, "    MSG: %T\n", ctx->msg);
+            erts_fprintf(stderr, ">> CTL: %T\n", ctx->ctl);
+            if (is_value(ctx->msg))
+                erts_fprintf(stderr, "    MSG: %T\n", ctx->msg);
     #endif
 
-	    ctx->data_size = ctx->pass_through_size;
+	    ctx->data_size = ctx->max_finalize_prepend;
 	    erts_reset_atom_cache_map(ctx->acmp);
 	    erts_encode_dist_ext_size(ctx->ctl, ctx->flags, ctx->acmp, &ctx->data_size);
 
-	    if (is_value(ctx->msg)) {
-		ctx->u.sc.wstack.wstart = NULL;
-		ctx->u.sc.flags = ctx->flags;
-		ctx->u.sc.level = 0;
-		ctx->phase = ERTS_DSIG_SEND_PHASE_MSG_SIZE;
-	    } else {
-		ctx->phase = ERTS_DSIG_SEND_PHASE_ALLOC;
-	    }
-	    break;
+	    if (is_non_value(ctx->msg)) {
+                ctx->phase = ERTS_DSIG_SEND_PHASE_ALLOC;
+                break;
+            }
+            ctx->u.sc.wstack.wstart = NULL;
+            ctx->u.sc.flags = ctx->flags;
+            ctx->u.sc.level = 0;
 
+            ctx->phase = ERTS_DSIG_SEND_PHASE_MSG_SIZE;
 	case ERTS_DSIG_SEND_PHASE_MSG_SIZE:
 	    if (erts_encode_dist_ext_size_int(ctx->msg, ctx, &ctx->data_size)) {
 		retval = ERTS_DSIG_SEND_CONTINUE;
@@ -1922,23 +1946,24 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
 	    ctx->data_size += ctx->dhdr_ext_size;
 
 	    ctx->obuf = alloc_dist_obuf(ctx->data_size);
-	    ctx->obuf->ext_endp = &ctx->obuf->data[0] + ctx->pass_through_size + ctx->dhdr_ext_size;
+	    ctx->obuf->ext_endp = &ctx->obuf->data[0] + ctx->max_finalize_prepend + ctx->dhdr_ext_size;
 
 	    /* Encode internal version of dist header */
 	    ctx->obuf->extp = erts_encode_ext_dist_header_setup(ctx->obuf->ext_endp, ctx->acmp);
 	    /* Encode control message */
 	    erts_encode_dist_ext(ctx->ctl, &ctx->obuf->ext_endp, ctx->flags, ctx->acmp, NULL, NULL);
-	    if (is_value(ctx->msg)) {
-		ctx->u.ec.flags = ctx->flags;
-		ctx->u.ec.level = 0;
-		ctx->u.ec.wstack.wstart = NULL;
-		ctx->phase = ERTS_DSIG_SEND_PHASE_MSG_ENCODE;
-	    } else {
-		ctx->phase = ERTS_DSIG_SEND_PHASE_FIN;
-	    }
-	    break;
+	    if (is_non_value(ctx->msg)) {
+                ctx->obuf->msg_start = NULL;
+                ctx->phase = ERTS_DSIG_SEND_PHASE_FIN;
+                break;
+            }
+            ctx->u.ec.flags = ctx->flags;
+            ctx->u.ec.level = 0;
+            ctx->u.ec.wstack.wstart = NULL;
+            ctx->obuf->msg_start = ctx->obuf->ext_endp;
 
-	case ERTS_DSIG_SEND_PHASE_MSG_ENCODE:
+            ctx->phase = ERTS_DSIG_SEND_PHASE_MSG_ENCODE;
+        case ERTS_DSIG_SEND_PHASE_MSG_ENCODE:
 	    if (erts_encode_dist_ext(ctx->msg, &ctx->obuf->ext_endp, ctx->flags, ctx->acmp, &ctx->u.ec, &ctx->reds)) {
 		retval = ERTS_DSIG_SEND_CONTINUE;
 		goto done;
@@ -1951,7 +1976,7 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
 	    int resume = 0;
 
 	    ASSERT(ctx->obuf->extp < ctx->obuf->ext_endp);
-	    ASSERT(&ctx->obuf->data[0] <= ctx->obuf->extp - ctx->pass_through_size);
+	    ASSERT(&ctx->obuf->data[0] <= ctx->obuf->extp - ctx->max_finalize_prepend);
 	    ASSERT(ctx->obuf->ext_endp <= &ctx->obuf->data[0] + ctx->data_size);
 
 	    ctx->data_size = ctx->obuf->ext_endp - ctx->obuf->extp;
@@ -1963,9 +1988,9 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
 	    ctx->obuf->next = NULL;
 	    erts_de_rlock(dep);
 	    cid = dep->cid;
-	    if (cid != dsdp->cid
-		|| dep->connection_id != dsdp->connection_id
-		|| dep->status & ERTS_DE_SFLG_EXITING) {
+	    if (!(dep->status & (ERTS_DE_SFLG_PENDING | ERTS_DE_SFLG_CONNECTED))
+                || dep->status & ERTS_DE_SFLG_EXITING
+                || dep->connection_id != dsdp->connection_id) {
 		/* Not the same connection as when we started; drop message... */
 		erts_de_runlock(dep);
 		free_dist_obuf(ctx->obuf);
@@ -2039,8 +2064,13 @@ erts_dsig_send(ErtsDSigData *dsdp, struct erts_dsig_send_context* ctx)
 		}
 
 		erts_mtx_unlock(&dep->qlock);
-                if (is_internal_port(dep->cid))
-                    erts_schedule_dist_command(NULL, dep);
+		if (!(dep->status & ERTS_DE_SFLG_PENDING)) {
+                    if (is_internal_port(dep->cid))
+                        erts_schedule_dist_command(NULL, dep);
+                }
+                else {
+                    notify_proc = NIL;
+                }
 		erts_de_runlock(dep);
                 if (is_internal_pid(notify_proc))
                     notify_dist_data(ctx->c_p, notify_proc);
@@ -2205,7 +2235,6 @@ dist_port_commandv(Port *prt, ErtsDistOutputBuf *obuf)
 #endif
 
 #define ERTS_PORT_REDS_DIST_CMD_START 5
-#define ERTS_PORT_REDS_DIST_CMD_FINALIZE 3
 #define ERTS_PORT_REDS_DIST_CMD_EXIT 200
 #define ERTS_PORT_REDS_DIST_CMD_RESUMED 5
 #define ERTS_PORT_REDS_DIST_CMD_DATA(SZ) \
@@ -2214,9 +2243,9 @@ dist_port_commandv(Port *prt, ErtsDistOutputBuf *obuf)
    : ((((Sint) (SZ)) >> 10) & ((Sint) ERTS_PORT_REDS_MASK__)))
 
 int
-erts_dist_command(Port *prt, int reds_limit)
+erts_dist_command(Port *prt, int initial_reds)
 {
-    Sint reds = ERTS_PORT_REDS_DIST_CMD_START;
+    Sint reds = initial_reds - ERTS_PORT_REDS_DIST_CMD_START;
     Uint32 status;
     Uint32 flags;
     Sint qsize, obufsize = 0;
@@ -2238,9 +2267,12 @@ erts_dist_command(Port *prt, int reds_limit)
 
     if (status & ERTS_DE_SFLG_EXITING) {
 	erts_deliver_port_exit(prt, prt->common.id, am_killed, 0, 1);
-	return reds + ERTS_PORT_REDS_DIST_CMD_EXIT;
+        reds -= ERTS_PORT_REDS_DIST_CMD_EXIT;
+	return initial_reds - reds;
     }
 
+    ASSERT(!(status & ERTS_DE_SFLG_PENDING));
+
     ASSERT(send);
 
     /*
@@ -2265,7 +2297,7 @@ erts_dist_command(Port *prt, int reds_limit)
 
     sched_flags = erts_atomic32_read_nob(&prt->sched.flags);
 
-    if (reds > reds_limit)
+    if (reds < 0)
 	goto preempted;
 
     if (!(sched_flags & ERTS_PTS_FLG_BUSY_PORT) && foq.first) {
@@ -2280,13 +2312,13 @@ erts_dist_command(Port *prt, int reds_limit)
             erts_fprintf(stderr, ">> ");
             bw(foq.first->extp, size);
 #endif
-            reds += ERTS_PORT_REDS_DIST_CMD_DATA(size);
-            fob = foq.first;
-            obufsize += size_obuf(fob);
-            foq.first = foq.first->next;
-            free_dist_obuf(fob);
+	    reds -= ERTS_PORT_REDS_DIST_CMD_DATA(size);
+	    fob = foq.first;
+	    obufsize += size_obuf(fob);
+	    foq.first = foq.first->next;
+	    free_dist_obuf(fob);
 	    sched_flags = erts_atomic32_read_nob(&prt->sched.flags);
-	    preempt = reds > reds_limit || (sched_flags & ERTS_PTS_FLG_EXIT);
+	    preempt = reds < 0 || (sched_flags & ERTS_PTS_FLG_EXIT);
 	    if (sched_flags & ERTS_PTS_FLG_BUSY_PORT)
 		break;
 	} while (foq.first && !preempt);
@@ -2299,81 +2331,71 @@ erts_dist_command(Port *prt, int reds_limit)
     if (sched_flags & ERTS_PTS_FLG_BUSY_PORT) {
 	if (oq.first) {
 	    ErtsDistOutputBuf *ob;
-	    int preempt;
+            ErtsDistOutputBuf *last_finalized = NULL;
 	finalize_only:
-	    preempt = 0;
 	    ob = oq.first;
 	    ASSERT(ob);
 	    do {
-		ob->extp = erts_encode_ext_dist_header_finalize(ob->extp,
-								dep->cache,
-								flags);
-		if (!(flags & DFLAG_DIST_HDR_ATOM_CACHE))
-		    *--ob->extp = PASS_THROUGH; /* Old node; 'pass through'
-						   needed */
-		ASSERT(&ob->data[0] <= ob->extp && ob->extp < ob->ext_endp);
-		reds += ERTS_PORT_REDS_DIST_CMD_FINALIZE;
-		preempt = reds > reds_limit;
-		if (preempt)
-		    break;
-		ob = ob->next;
+		reds = erts_encode_ext_dist_header_finalize(ob, dep, flags, reds);
+                if (reds >= 0) {
+                    last_finalized  = ob;
+                    ob = ob->next;
+                }
 	    } while (ob);
-	    /*
-	     * At least one buffer was finalized; if we got preempted,
-	     * ob points to the last buffer that we finalized.
-	     */
-	    if (foq.last)
-		foq.last->next = oq.first;
-	    else
-		foq.first = oq.first;
-	    if (!preempt) {
-		/* All buffers finalized */
-		foq.last = oq.last;
-		oq.first = oq.last = NULL;
-	    }
-	    else {
-		/* Not all buffers finalized; split oq. */
-		foq.last = ob;
-		oq.first = ob->next;
-		if (oq.first)
-		    ob->next = NULL;
-		else
-		    oq.last = NULL;
-	    }
-	    if (preempt)
-		goto preempted;
+            if (last_finalized) {
+                /*
+                 * At least one buffer was finalized; if we got preempted,
+                 * ob points to the next buffer to continue finalize.
+                 */
+                if (foq.last)
+                    foq.last->next = oq.first;
+                else
+                    foq.first = oq.first;
+                foq.last = last_finalized;
+                if (!ob) {
+                    /* All buffers finalized */
+                    ASSERT(foq.last == oq.last);
+                    ASSERT(foq.last->next == NULL);
+                    oq.first = oq.last = NULL;
+                }
+                else {
+                    /* Not all buffers finalized; split oq. */
+                    ASSERT(foq.last->next == ob);
+                    foq.last->next = NULL;
+                    oq.first = ob;
+                }
+            }
+            if (reds <= 0)
+                goto preempted;
 	}
     }
     else {
         int de_busy;
 	int preempt = 0;
 	while (oq.first && !preempt) {
-            ErtsDistOutputBuf *fob;
-            Uint size;
-            oq.first->extp
-                = erts_encode_ext_dist_header_finalize(oq.first->extp,
-                                                       dep->cache,
-                                                       flags);
-            reds += ERTS_PORT_REDS_DIST_CMD_FINALIZE;
-            if (!(flags & DFLAG_DIST_HDR_ATOM_CACHE))
-                *--oq.first->extp = PASS_THROUGH; /* Old node; 'pass through'
-                                                     needed */
-            ASSERT(&oq.first->data[0] <= oq.first->extp
-                   && oq.first->extp < oq.first->ext_endp);
-            size = (*send)(prt, oq.first);
+	    ErtsDistOutputBuf *fob;
+	    Uint size;
+            reds = erts_encode_ext_dist_header_finalize(oq.first, dep, flags, reds);
+            if (reds < 0) {
+                preempt = 1;
+                break;
+            }
+	    ASSERT(&oq.first->data[0] <= oq.first->extp
+		   && oq.first->extp < oq.first->ext_endp);
+	    size = (*send)(prt, oq.first);
             erts_atomic64_inc_nob(&dep->out);
-            esdp->io.out += (Uint64) size;
+	    esdp->io.out += (Uint64) size;
 #ifdef ERTS_RAW_DIST_MSG_DBG
             erts_fprintf(stderr, ">> ");
             bw(oq.first->extp, size);
 #endif
-            reds += ERTS_PORT_REDS_DIST_CMD_DATA(size);
-            fob = oq.first;
-            obufsize += size_obuf(fob);
-            oq.first = oq.first->next;
-            free_dist_obuf(fob);
+	    reds -= ERTS_PORT_REDS_DIST_CMD_DATA(size);
+	    fob = oq.first;
+	    obufsize += size_obuf(fob);
+	    oq.first = oq.first->next;
+	    free_dist_obuf(fob);
 	    sched_flags = erts_atomic32_read_nob(&prt->sched.flags);
-	    preempt = reds > reds_limit || (sched_flags & ERTS_PTS_FLG_EXIT);
+	    preempt = reds <= 0 || (sched_flags & ERTS_PTS_FLG_EXIT);
 	    if ((sched_flags & ERTS_PTS_FLG_BUSY_PORT) && oq.first && !preempt)
 		goto finalize_only;
 	}
@@ -2413,7 +2435,7 @@ erts_dist_command(Port *prt, int reds_limit)
 	    erts_mtx_unlock(&dep->qlock);
 
 	    resumed = erts_resume_processes(suspendees);
-	    reds += resumed*ERTS_PORT_REDS_DIST_CMD_RESUMED;
+	    reds -= resumed*ERTS_PORT_REDS_DIST_CMD_RESUMED;
 	}
 	else
 	    erts_mtx_unlock(&dep->qlock);
@@ -2436,8 +2458,7 @@ erts_dist_command(Port *prt, int reds_limit)
 	erts_mtx_unlock(&dep->qlock);
     }
 
-    ASSERT(foq.first || !foq.last);
-    ASSERT(!foq.first || foq.last);
+    ASSERT(!!foq.first == !!foq.last);
     ASSERT(!dep->finalized_out_queue.first);
     ASSERT(!dep->finalized_out_queue.last);
 
@@ -2447,10 +2468,10 @@ erts_dist_command(Port *prt, int reds_limit)
     }
 
      /* Avoid wrapping reduction counter... */
-    if (reds > INT_MAX/2)
-	reds = INT_MAX/2;
+    if (reds < INT_MIN/2)
+	reds = INT_MIN/2;
 
-    return reds;
+    return initial_reds - reds;
 
  preempted:
     /*
@@ -2458,8 +2479,7 @@ erts_dist_command(Port *prt, int reds_limit)
      * since last call to driver.
      */
 
-    ASSERT(oq.first || !oq.last);
-    ASSERT(!oq.first || oq.last);
+    ASSERT(!!oq.first == !!oq.last);
 
     if (sched_flags & ERTS_PTS_FLG_EXIT) {
 	/*
@@ -2483,12 +2503,6 @@ erts_dist_command(Port *prt, int reds_limit)
 
 	foq.first = NULL;
 	foq.last = NULL;
-
-#ifdef DEBUG
-	erts_mtx_lock(&dep->qlock);
-	ASSERT(erts_atomic_read_nob(&dep->qsize) == obufsize);
-	erts_mtx_unlock(&dep->qlock);
-#endif
     }
     else {
 	if (oq.first) {
@@ -2778,7 +2792,8 @@ BIF_RETTYPE
 dist_ctrl_get_data_1(BIF_ALIST_1)
 {
     DistEntry *dep = ERTS_PROC_GET_DIST_ENTRY(BIF_P);
-    int reds = 1;
+    const Sint initial_reds = ERTS_BIF_REDS_LEFT(BIF_P);
+    Sint reds = initial_reds;
     ErtsDistOutputBuf *obuf;
     Eterm *hp;
     ProcBin *pb;
@@ -2809,6 +2824,7 @@ dist_ctrl_get_data_1(BIF_ALIST_1)
     {
         if (!dep->tmp_out_queue.first) {
             ASSERT(!dep->tmp_out_queue.last);
+            ASSERT(!dep->transcode_ctx);
             qsize = erts_atomic_read_acqb(&dep->qsize);
             if (qsize > 0) {
                 erts_mtx_lock(&dep->qlock);
@@ -2826,21 +2842,18 @@ dist_ctrl_get_data_1(BIF_ALIST_1)
             erts_de_runlock(dep);
             BIF_RET(am_none);
         }
-        else {
-            obuf = dep->tmp_out_queue.first;
-            dep->tmp_out_queue.first = obuf->next;
-            if (!obuf->next)
-                dep->tmp_out_queue.last = NULL;
+
+        obuf = dep->tmp_out_queue.first;
+        reds = erts_encode_ext_dist_header_finalize(obuf, dep, dep->flags, reds);
+        if (reds < 0) {
+            erts_de_runlock(dep);
+            ERTS_BIF_YIELD1(bif_export[BIF_dist_ctrl_get_data_1],
+                            BIF_P, BIF_ARG_1);
         }
 
-        obuf->extp = erts_encode_ext_dist_header_finalize(obuf->extp,
-                                                          dep->cache,
-                                                          dep->flags);
-        reds += ERTS_PORT_REDS_DIST_CMD_FINALIZE;
-        if (!(dep->flags & DFLAG_DIST_HDR_ATOM_CACHE))
-            *--obuf->extp = PASS_THROUGH; /* 'pass through' needed */
-        ASSERT(&obuf->data[0] <= obuf->extp
-               && obuf->extp < obuf->ext_endp);
+        dep->tmp_out_queue.first = obuf->next;
+        if (!obuf->next)
+            dep->tmp_out_queue.last = NULL;
     }
 
     erts_atomic64_inc_nob(&dep->out);
@@ -2868,11 +2881,11 @@ dist_ctrl_get_data_1(BIF_ALIST_1)
         erts_mtx_unlock(&dep->qlock);
         if (resume_procs) {
             int resumed = erts_resume_processes(resume_procs);
-            reds += resumed*ERTS_PORT_REDS_DIST_CMD_RESUMED;
+            reds -= resumed*ERTS_PORT_REDS_DIST_CMD_RESUMED;
         }
     }
 
-    BIF_RET2(make_binary(pb), reds);
+    BIF_RET2(make_binary(pb), (initial_reds - reds));
 }
 
 void
@@ -2894,24 +2907,31 @@ erts_dist_port_not_busy(Port *prt)
     erts_schedule_dist_command(prt, NULL);
 }
 
+static void kill_connection(DistEntry *dep)
+{
+    ERTS_LC_ASSERT(erts_lc_is_de_rwlocked(dep));
+    ASSERT(dep->status == ERTS_DE_SFLG_CONNECTED);
+
+    dep->status |= ERTS_DE_SFLG_EXITING;
+    erts_mtx_lock(&dep->qlock);
+    ASSERT(!(erts_atomic32_read_nob(&dep->qflgs) & ERTS_DE_QFLG_EXIT));
+    erts_atomic32_read_bor_nob(&dep->qflgs, ERTS_DE_QFLG_EXIT);
+    erts_mtx_unlock(&dep->qlock);
+
+    if (is_internal_port(dep->cid))
+        erts_schedule_dist_command(NULL, dep);
+    else if (is_internal_pid(dep->cid))
+        schedule_kill_dist_ctrl_proc(dep->cid);
+}
+
 void
 erts_kill_dist_connection(DistEntry *dep, Uint32 connection_id)
 {
     erts_de_rwlock(dep);
     if (connection_id == dep->connection_id
-	&& !(dep->status & ERTS_DE_SFLG_EXITING)) {
+        && dep->status == ERTS_DE_SFLG_CONNECTED) {
 
-	dep->status |= ERTS_DE_SFLG_EXITING;
-
-	erts_mtx_lock(&dep->qlock);
-	ASSERT(!(erts_atomic32_read_nob(&dep->qflgs) & ERTS_DE_QFLG_EXIT));
-	erts_atomic32_read_bor_nob(&dep->qflgs, ERTS_DE_QFLG_EXIT);
-	erts_mtx_unlock(&dep->qlock);
-
-        if (is_internal_port(dep->cid))
-            erts_schedule_dist_command(NULL, dep);
-        else if (is_internal_pid(dep->cid))
-            schedule_kill_dist_ctrl_proc(dep->cid);
+        kill_connection(dep);
     }
     erts_de_rwunlock(dep);
 }
@@ -3071,6 +3091,10 @@ int distribution_info(fmtfn_t to, void *arg)	/* Called by break handler */
       info_dist_entry(to, arg, dep, 0, 1);
     }
 
+    for (dep = erts_pending_dist_entries; dep; dep = dep->next) {
+        info_dist_entry(to, arg, dep, 0, 0);
+    }
+
     for (dep = erts_not_connected_dist_entries; dep; dep = dep->next) {
         if (dep != erts_this_dist_entry) {
             info_dist_entry(to, arg, dep, 0, 0);
@@ -3093,7 +3117,6 @@ int distribution_info(fmtfn_t to, void *arg)	/* Called by break handler */
 	    monitor_node  -- turn on/off node monitoring
 
             node controller only:
-            dist_exit/3       -- send exit signals from remote to local process
             dist_link/2       -- link a remote process to a local
             dist_unlink/2     -- unlink a remote from a local
 ****************************************************************************/
@@ -3103,15 +3126,6 @@ int distribution_info(fmtfn_t to, void *arg)	/* Called by break handler */
 /**********************************************************************
  ** Set the node name of current node fail if node already is set.
  ** setnode(name@host, Creation)
- ** loads functions pointer to trap_functions from module erlang.
- **    erlang:dsend/2
- **    erlang:dlink/1
- **    erlang:dunlink/1
- **    erlang:dmonitor_node/3
- **    erlang:dgroup_leader/2
- **    erlang:dexit/2
- **  -- are these needed ?
- **    dexit/1
  ***********************************************************************/
 
 BIF_RETTYPE setnode_2(BIF_ALIST_2)
@@ -3135,15 +3149,8 @@ BIF_RETTYPE setnode_2(BIF_ALIST_2)
 	goto error;
 
     /* Check that all trap functions are defined !! */
-    if (dsend2_trap->addressv[0] == NULL ||
-	dsend3_trap->addressv[0] == NULL ||
-	/*	dsend_nosuspend_trap->address == NULL ||*/
-	dlink_trap->addressv[0] == NULL ||
-	dunlink_trap->addressv[0] == NULL ||
-	dmonitor_node_trap->addressv[0] == NULL ||
-	dgroup_leader_trap->addressv[0] == NULL ||
-	dmonitor_p_trap->addressv[0] == NULL ||
-	dexit_trap->addressv[0] == NULL) {
+    if (dmonitor_node_trap->addressv[0] == NULL ||
+	dmonitor_p_trap->addressv[0] == NULL) {
 	goto error;
     }
 
@@ -3220,6 +3227,8 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     ErtsProcLocks proc_unlock = 0;
     Process *proc;
     Port *pp = NULL;
+    Eterm notify_proc;
+    erts_aint32_t qflgs;
 
     /*
      * Check and pick out arguments
@@ -3247,21 +3256,25 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     if (!is_atom(ic) || !is_atom(oc))
 	goto badarg;
 
-    /* DFLAG_EXTENDED_REFERENCES is compulsory from R9 and forward */
-    if (!(DFLAG_EXTENDED_REFERENCES & flags)) {
+    if (~flags & DFLAG_DIST_MANDATORY) {
 	erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
 	erts_dsprintf(dsbufp, "%T", BIF_P->common.id);
 	if (BIF_P->common.u.alive.reg)
 	    erts_dsprintf(dsbufp, " (%T)", BIF_P->common.u.alive.reg->name);
 	erts_dsprintf(dsbufp,
 		      " attempted to enable connection to node %T "
-		      "which is not able to handle extended references.\n",
+		      "which does not support all mandatory capabilities.\n",
 		      BIF_ARG_1);
 	erts_send_error_to_logger(BIF_P->group_leader, dsbufp);
 	goto badarg;
     }
 
     /*
+     * ToDo: Should we not pass connection_id as well
+     *       to make sure it's the right connection we commit.
+     */
+
+    /*
      * Arguments seem to be in order.
      */
 
@@ -3304,6 +3317,23 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
             goto badarg;
         }
 
+        if (dep->status & ERTS_DE_SFLG_EXITING) {
+            /* Suspend on dist entry waiting for the exit to finish */
+            ErtsProcList *plp = erts_proclist_create(BIF_P);
+            plp->next = NULL;
+            erts_suspend(BIF_P, ERTS_PROC_LOCK_MAIN, NULL);
+            erts_mtx_lock(&dep->qlock);
+            erts_proclist_store_last(&dep->suspended, plp);
+            erts_mtx_unlock(&dep->qlock);
+            goto yield;
+        }
+        if (dep->status != ERTS_DE_SFLG_PENDING) {
+            if (dep->status == 0)
+                erts_set_dist_entry_pending(dep);
+            else
+                goto badarg;
+        }
+
         if (is_not_nil(dep->cid))
             goto badarg;
 
@@ -3346,8 +3376,12 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
             erts_mtx_unlock(&dep->qlock);
             goto yield;
         }
-
-        ASSERT(!(dep->status & ERTS_DE_SFLG_EXITING));
+        if (dep->status != ERTS_DE_SFLG_PENDING) {
+            if (dep->status == 0)
+                erts_set_dist_entry_pending(dep);
+            else
+                goto badarg;
+        }
 
         if (pp->dist_entry || is_not_nil(dep->cid))
             goto badarg;
@@ -3378,7 +3412,8 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     dep->creation = 0;
 
 #ifdef DEBUG
-    ASSERT(erts_atomic_read_nob(&dep->qsize) == 0);
+    ASSERT(erts_atomic_read_nob(&dep->qsize) == 0 
+           || (dep->status & ERTS_DE_SFLG_PENDING));
 #endif
 
     if (flags & DFLAG_DIST_HDR_ATOM_CACHE)
@@ -3386,7 +3421,26 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
 
     erts_set_dist_entry_connected(dep, BIF_ARG_2, flags);
 
+    notify_proc = NIL;
+    if (erts_atomic_read_nob(&dep->qsize)) {
+        if (is_internal_port(dep->cid)) {
+            erts_schedule_dist_command(NULL, dep);
+        }
+        else {
+            qflgs = erts_atomic32_read_nob(&dep->qflgs);
+            if (qflgs & ERTS_DE_QFLG_REQ_INFO) {
+                qflgs = erts_atomic32_read_band_mb(&dep->qflgs,
+                                                   ~ERTS_DE_QFLG_REQ_INFO);
+                if (qflgs & ERTS_DE_QFLG_REQ_INFO) {
+                    notify_proc = dep->cid;
+                    ASSERT(is_internal_pid(notify_proc));
+                }
+            }
+        }
+    }
     erts_de_rwunlock(dep);
+    if (is_internal_pid(notify_proc))
+        notify_dist_data(BIF_P, notify_proc);
 
     ERTS_BIF_PREP_RET(ret, erts_make_dhandle(BIF_P, dep));
 
@@ -3428,79 +3482,168 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     goto done;
 }
 
+BIF_RETTYPE erts_internal_new_connection_1(BIF_ALIST_1)
+{
+    DistEntry* dep;
+    Uint32 conn_id;
+    Eterm* hp;
+    Eterm dhandle;
 
-/**********************************************************************/
-/* dist_exit(Local, Term, Remote) -> Bool */
+    if (is_not_atom(BIF_ARG_1)) {
+	BIF_ERROR(BIF_P, BADARG);
+    }
+    dep = erts_find_or_insert_dist_entry(BIF_ARG_1);
+
+    if (dep == erts_this_dist_entry) {
+        erts_deref_dist_entry(dep);
+        BIF_ERROR(BIF_P, BADARG);
+    }
+
+    erts_de_rwlock(dep);
+
+    if (ERTS_DE_IS_CONNECTED(dep) || dep->status & ERTS_DE_SFLG_PENDING)
+	conn_id = dep->connection_id;
+    else if (dep->status == 0) {
+        erts_set_dist_entry_pending(dep);
+	conn_id = dep->connection_id;
+    }
+    else {
+        ASSERT(dep->status & ERTS_DE_SFLG_EXITING);
+        conn_id = (dep->connection_id + 1) & ERTS_DIST_CON_ID_MASK;
+    }
+    erts_de_rwunlock(dep);
+    hp = HAlloc(BIF_P, 3 + ERTS_MAGIC_REF_THING_SIZE);
+    dhandle = erts_build_dhandle(&hp, &BIF_P->off_heap, dep);
+    erts_deref_dist_entry(dep);
+    BIF_RET(TUPLE2(hp, make_small(conn_id), dhandle));
+}
 
-BIF_RETTYPE dist_exit_3(BIF_ALIST_3)
+static Sint abort_connection(DistEntry* dep, Uint32 conn_id)
 {
-    Eterm local;
-    Eterm remote;
-    DistEntry *rdep;
+    erts_de_rwlock(dep);
 
-    local = BIF_ARG_1;
-    remote = BIF_ARG_3;
+    if (dep->connection_id != conn_id)
+        ;
+    else if (dep->status == ERTS_DE_SFLG_CONNECTED) {
+        kill_connection(dep);
+    }
+    else if (dep->status == ERTS_DE_SFLG_PENDING) {
+        NetExitsContext nec = {dep};
+        ErtsLink *nlinks;
+        ErtsLink *node_links;
+        ErtsMonitor *monitors;
+        ErtsAtomCache *cache;
+        ErtsDistOutputBuf *obuf;
+        ErtsProcList *resume_procs;
+        Sint reds = 0;
+
+	ASSERT(is_nil(dep->cid));
 
-    /* Check that remote is a remote process */
-    if (is_not_external_pid(remote))
-	goto error;
+	erts_de_links_lock(dep);
+	monitors	= dep->monitors;
+	nlinks		= dep->nlinks;
+	node_links	= dep->node_links;
+	dep->monitors	= NULL;
+	dep->nlinks	= NULL;
+	dep->node_links	= NULL;
+	erts_de_links_unlock(dep);
 
-    rdep = external_dist_entry(remote);
-    
-    if(rdep == erts_this_dist_entry)
-	goto error;
+	cache = dep->cache;
+	dep->cache = NULL;
+	erts_mtx_lock(&dep->qlock);
+        obuf = dep->out_queue.first;
+        dep->out_queue.first = NULL;
+        dep->out_queue.last = NULL;
+        ASSERT(!dep->tmp_out_queue.first);
+        ASSERT(!dep->finalized_out_queue.first);
+        resume_procs = get_suspended_on_de(dep, ERTS_DE_QFLGS_ALL);
+	erts_mtx_unlock(&dep->qlock);
+	erts_atomic_set_nob(&dep->dist_cmd_scheduled, 0);
+	dep->send = NULL;
 
-    /* Check that local is local */
-    if (is_internal_pid(local)) {
-	Process *lp;
-	ErtsProcLocks lp_locks;
-	if (BIF_P->common.id == local) {
-	    lp_locks = ERTS_PROC_LOCKS_ALL;
-	    lp = BIF_P;
-	    erts_proc_lock(BIF_P, ERTS_PROC_LOCKS_ALL_MINOR);
-	}
-	else {
-	    lp_locks = ERTS_PROC_LOCKS_XSIG_SEND;
-	    lp = erts_pid2proc(BIF_P, ERTS_PROC_LOCK_MAIN,
-			       local, lp_locks);
-	    if (!lp) {
-		BIF_RET(am_true); /* ignore */
-	    }
-	}
-	
-	(void) erts_send_exit_signal(BIF_P,
-				     remote,
-				     lp,
-				     &lp_locks,
-				     BIF_ARG_2,
-				     NIL,
-				     NULL,
-				     0);
-	if (lp == BIF_P)
-	    lp_locks &= ~ERTS_PROC_LOCK_MAIN;
-	erts_proc_unlock(lp, lp_locks);
-	if (lp == BIF_P) {
-	    erts_aint32_t state = erts_atomic32_read_acqb(&BIF_P->state);
-	    /*
-	     * We may have exited current process and may have to take action.
-	     */
-	    if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT)) {
-		if (state & ERTS_PSFLG_PENDING_EXIT)
-		    erts_handle_pending_exit(BIF_P, ERTS_PROC_LOCK_MAIN);
-		ERTS_BIF_EXITED(BIF_P);
-	    }
-	}
+        erts_set_dist_entry_not_connected(dep);
+
+	erts_de_rwunlock(dep);
+
+	erts_sweep_monitors(monitors, &doit_monitor_net_exits, &nec);
+	erts_sweep_links(nlinks, &doit_link_net_exits, &nec);
+	erts_sweep_links(node_links, &doit_node_link_net_exits, &nec);
+
+        if (resume_procs) {
+            int resumed = erts_resume_processes(resume_procs);
+            reds += resumed*ERTS_PORT_REDS_DIST_CMD_RESUMED;
+        }
+
+	delete_cache(cache);
+	free_de_out_queues(dep, obuf);
+        return reds;
     }
-    else if (is_external_pid(local)
-	     && external_dist_entry(local) == erts_this_dist_entry) {
-	BIF_RET(am_true); /* ignore */
+    erts_de_rwunlock(dep);
+    return 0;
+}
+
+BIF_RETTYPE erts_internal_abort_connection_2(BIF_ALIST_2)
+{
+    DistEntry* dep;
+    Eterm* tp;
+
+    if (is_not_atom(BIF_ARG_1) || is_not_tuple_arity(BIF_ARG_2, 2)) {
+	BIF_ERROR(BIF_P, BADARG);
+    }
+    tp = tuple_val(BIF_ARG_2);
+    dep = erts_dhandle_to_dist_entry(tp[2]);
+    if (is_not_small(tp[1]) || dep != erts_find_dist_entry(BIF_ARG_1)
+        || dep == erts_this_dist_entry) {
+        BIF_ERROR(BIF_P, BADARG);
+    }
+
+    if (dep) {
+        Sint reds = abort_connection(dep, unsigned_val(tp[1]));
+        BUMP_REDS(BIF_P, reds);
     }
-    else
-	goto error;
     BIF_RET(am_true);
+}
 
- error:
-    BIF_ERROR(BIF_P, BADARG);
+int erts_auto_connect(DistEntry* dep, Process *proc, ErtsProcLocks proc_locks)
+{
+    erts_de_rwlock(dep);
+    if (dep->status != 0) {
+        erts_de_rwunlock(dep);
+    }
+    else {
+        Process* net_kernel;
+        ErtsProcLocks nk_locks = ERTS_PROC_LOCK_MSGQ;
+        Eterm *hp;
+        ErlOffHeap *ohp;
+        ErtsMessage *mp;
+        Eterm msg, dhandle;
+        Uint32 conn_id;
+
+        erts_set_dist_entry_pending(dep);
+        conn_id = dep->connection_id;
+        erts_de_rwunlock(dep);
+
+        net_kernel = erts_whereis_process(proc, proc_locks,
+                                          am_net_kernel, nk_locks, 0);
+        if (!net_kernel) {
+            abort_connection(dep, conn_id);
+            return 0;
+        }
+
+        /*
+         * Send {auto_connect, Node, ConnId, DHandle} to net_kernel
+         */
+        mp = erts_alloc_message_heap(net_kernel, &nk_locks,
+                                     5 + ERTS_MAGIC_REF_THING_SIZE,
+                                     &hp, &ohp);
+        dhandle = erts_build_dhandle(&hp, ohp, dep);
+        msg = TUPLE4(hp, am_auto_connect, dep->sysname, make_small(conn_id),
+                     dhandle);
+        erts_queue_message(net_kernel, nk_locks, mp, msg, proc->common.id);
+        erts_proc_unlock(net_kernel, nk_locks);
+    }
+
+    return 1;
 }
 
 /**********************************************************************/
@@ -3576,9 +3719,11 @@ BIF_RETTYPE nodes_1(BIF_ALIST_1)
 
     ASSERT(erts_no_of_not_connected_dist_entries > 0);
     ASSERT(erts_no_of_hidden_dist_entries >= 0);
+    ASSERT(erts_no_of_pending_dist_entries >= 0);
     ASSERT(erts_no_of_visible_dist_entries >= 0);
     if(not_connected)
-      length += (erts_no_of_not_connected_dist_entries - 1);
+      length += ((erts_no_of_not_connected_dist_entries - 1)
+                 + erts_no_of_pending_dist_entries);
     if(hidden)
       length += erts_no_of_hidden_dist_entries;
     if(visible)
@@ -3598,13 +3743,18 @@ BIF_RETTYPE nodes_1(BIF_ALIST_1)
 #ifdef DEBUG
     endp = hp + length*2;
 #endif
-    if(not_connected)
+    if(not_connected) {
       for(dep = erts_not_connected_dist_entries; dep; dep = dep->next) {
           if (dep != erts_this_dist_entry) {
             result = CONS(hp, dep->sysname, result);
             hp += 2;
           }
+        }
+      for(dep = erts_pending_dist_entries; dep; dep = dep->next) {
+          result = CONS(hp, dep->sysname, result);
+          hp += 2;
       }
+    }
     if(hidden)
       for(dep = erts_hidden_dist_entries; dep; dep = dep->next) {
 	result = CONS(hp, dep->sysname, result);
@@ -3649,11 +3799,17 @@ monitor_node(Process* p, Eterm Node, Eterm Bool, Eterm Options)
     DistEntry *dep;
     ErtsLink *lnk;
     Eterm l;
+    int async_connect = 1;
 
     for (l = Options; l != NIL && is_list(l); l = CDR(list_val(l))) {
 	Eterm t = CAR(list_val(l));
-	/* allow_passive_connect the only available option right now */
-	if (t != am_allow_passive_connect) {
+	if (t == am_allow_passive_connect) {
+	    /*
+	     * Handle this horrible feature by falling back on old synchronous
+	     * auto-connect (if needed)
+	     */
+	    async_connect = 0;
+	} else {
 	    BIF_ERROR(p, BADARG);
 	}
     }
@@ -3667,50 +3823,90 @@ monitor_node(Process* p, Eterm Node, Eterm Bool, Eterm Options)
 	 && (Node != erts_this_node->sysname))) {
 	BIF_ERROR(p, BADARG);
     }
-    dep = erts_sysname_to_connected_dist_entry(Node);
-    if (!dep) {
-    do_trap:
-	BIF_TRAP3(dmonitor_node_trap, p, Node, Bool, Options);
-    }
-    if (dep == erts_this_dist_entry)
-	goto done;
-
-    erts_proc_lock(p, ERTS_PROC_LOCK_LINK);
-    erts_de_rlock(dep);
-    if (ERTS_DE_IS_NOT_CONNECTED(dep)) {
-	erts_proc_unlock(p, ERTS_PROC_LOCK_LINK);
-	erts_de_runlock(dep);
-	goto do_trap;
-    }
-    erts_de_links_lock(dep);
-    erts_de_runlock(dep);
 
     if (Bool == am_true) {
-	ASSERT(dep->cid != NIL);
-	lnk = erts_add_or_lookup_link(&(dep->node_links), LINK_NODE, 
-				      p->common.id);
-	++ERTS_LINK_REFC(lnk);
-	lnk = erts_add_or_lookup_link(&ERTS_P_LINKS(p), LINK_NODE, Node);
-	++ERTS_LINK_REFC(lnk);
-    }
-    else  {
-	lnk = erts_lookup_link(dep->node_links, p->common.id);
-	if (lnk != NULL) {
-	    if ((--ERTS_LINK_REFC(lnk)) == 0) {
-		erts_destroy_link(erts_remove_link(&(dep->node_links), 
-						   p->common.id));
-	    }
-	}
-	lnk = erts_lookup_link(ERTS_P_LINKS(p), Node);
-	if (lnk != NULL) {
-	    if ((--ERTS_LINK_REFC(lnk)) == 0) {
-		erts_destroy_link(erts_remove_link(&ERTS_P_LINKS(p),
-						   Node));
+        ErtsDSigData dsd;
+        dsd.node = Node;
+        dep = erts_find_or_insert_dist_entry(Node);
+        if (dep == erts_this_dist_entry)
+            goto done;
+
+        erts_proc_lock(p, ERTS_PROC_LOCK_LINK);
+
+        switch (erts_dsig_prepare(&dsd, dep, p,
+                                  (ERTS_PROC_LOCK_MAIN | ERTS_PROC_LOCK_LINK),
+                                  ERTS_DSP_RLOCK, 0, async_connect)) {
+        case ERTS_DSIG_PREP_NOT_ALIVE:
+	case ERTS_DSIG_PREP_NOT_CONNECTED:
+	    /* Trap to either send 'nodedown' or do passive connection attempt */
+	trap:
+            erts_proc_unlock(p, ERTS_PROC_LOCK_LINK);
+	    erts_deref_dist_entry(dep);
+            BIF_TRAP3(dmonitor_node_trap, p, Node, Bool, Options);
+	case ERTS_DSIG_PREP_PENDING:
+	    if (!async_connect) {
+		/*
+		 * Pending connection may fail, so we must trap
+		 * to ensure passive connection attempt
+		 */
+		erts_de_runlock(dep);
+		goto trap;
 	    }
-	}
+	    /*fall through*/
+        case ERTS_DSIG_PREP_CONNECTED:
+            erts_de_links_lock(dep);
+            erts_de_runlock(dep);
+            lnk = erts_add_or_lookup_link(&(dep->node_links), LINK_NODE,
+                                          p->common.id);
+            ++ERTS_LINK_REFC(lnk);
+            lnk = erts_add_or_lookup_link(&ERTS_P_LINKS(p), LINK_NODE, Node);
+            ++ERTS_LINK_REFC(lnk);
+            erts_de_links_unlock(dep);
+            break;
+        default:
+            ERTS_ASSERT(! "Invalid dsig prepare result");
+        }
+        erts_deref_dist_entry(dep);
+    }
+    else { /* Bool == false */
+        dep = erts_sysname_to_connected_dist_entry(Node);
+        if (!dep) {
+	    /*
+	     * Before OTP-21 this case triggered auto-connect
+	     * and a 'nodedown' message if that failed.
+	     * Now it's a simple no-op which feels more reasonable.
+	     */
+            BIF_RET(am_true);
+        }
+        if (dep == erts_this_dist_entry)
+            goto done;
+
+        erts_proc_lock(p, ERTS_PROC_LOCK_LINK);
+        erts_de_rlock(dep);
+        if (!(dep->status & (ERTS_DE_SFLG_PENDING | ERTS_DE_SFLG_CONNECTED))) {
+            erts_proc_unlock(p, ERTS_PROC_LOCK_LINK);
+            erts_de_runlock(dep);
+            goto done;
+        }
+        erts_de_links_lock(dep);
+        erts_de_runlock(dep);
+        lnk = erts_lookup_link(dep->node_links, p->common.id);
+        if (lnk != NULL) {
+            if ((--ERTS_LINK_REFC(lnk)) == 0) {
+                erts_destroy_link(erts_remove_link(&(dep->node_links),
+                                                   p->common.id));
+            }
+        }
+        lnk = erts_lookup_link(ERTS_P_LINKS(p), Node);
+        if (lnk != NULL) {
+            if ((--ERTS_LINK_REFC(lnk)) == 0) {
+                erts_destroy_link(erts_remove_link(&ERTS_P_LINKS(p),
+                                                   Node));
+            }
+        }
+        erts_de_links_unlock(dep);
     }
 
-    erts_de_links_unlock(dep);
     erts_proc_unlock(p, ERTS_PROC_LOCK_LINK);
 
  done:
diff --git a/erts/emulator/beam/dist.h b/erts/emulator/beam/dist.h
index d4765c50b8..a96e39be89 100644
--- a/erts/emulator/beam/dist.h
+++ b/erts/emulator/beam/dist.h
@@ -45,6 +45,18 @@
 #define DFLAG_MAP_TAG             0x20000
 #define DFLAG_BIG_CREATION        0x40000
 #define DFLAG_SEND_SENDER         0x80000
+#define DFLAG_NO_MAGIC            0x100000
+
+/* Mandatory flags for distribution (sync with dist_util.erl) */
+#define DFLAG_DIST_MANDATORY (DFLAG_EXTENDED_REFERENCES         \
+                              | DFLAG_EXTENDED_PIDS_PORTS       \
+			      | DFLAG_UTF8_ATOMS                \
+			      | DFLAG_NEW_FUN_TAGS)
+
+/* Additional optimistic flags when encoding toward pending connection */
+#define DFLAG_DIST_HOPEFULLY (DFLAG_NO_MAGIC                    \
+                              | DFLAG_EXPORT_PTR_TAG            \
+                              | DFLAG_BIT_BINARIES)
 
 /* All flags that should be enabled when term_to_binary/1 is used. */
 #define TERM_TO_BINARY_DFLAGS (DFLAG_EXTENDED_REFERENCES	\
@@ -79,25 +91,19 @@
 #define DOP_SEND_SENDER_TT      23
 
 /* distribution trap functions */
-extern Export* dsend2_trap;
-extern Export* dsend3_trap;
-extern Export* dlink_trap;
-extern Export* dunlink_trap;
 extern Export* dmonitor_node_trap;
-extern Export* dgroup_leader_trap;
-extern Export* dexit_trap;
 extern Export* dmonitor_p_trap;
 
 typedef enum {
     ERTS_DSP_NO_LOCK,
-    ERTS_DSP_RLOCK,
-    ERTS_DSP_RWLOCK
+    ERTS_DSP_RLOCK
 } ErtsDSigPrepLock;
 
 
 typedef struct {
     Process *proc;
     DistEntry *dep;
+    Eterm node;   /* used if dep == NULL */
     Eterm cid;
     Eterm connection_id;
     int no_suspend;
@@ -117,14 +123,10 @@ extern int erts_is_alive;
 
 /*
  * erts_dsig_prepare() prepares a send of a distributed signal.
- * One of the values defined below are returned. If the returned
- * value is another than ERTS_DSIG_PREP_CONNECTED, the
- * distributed signal cannot be sent before appropriate actions
- * have been taken. Appropriate actions would typically be setting
- * up the connection.
+ * One of the values defined below are returned.
  */
 
-/* Connected; signal can be sent. */
+/* Connected; signals can be enqueued and sent. */
 #define ERTS_DSIG_PREP_CONNECTED	0
 /* Not connected; connection needs to be set up. */
 #define ERTS_DSIG_PREP_NOT_CONNECTED	1
@@ -132,43 +134,80 @@ extern int erts_is_alive;
 #define ERTS_DSIG_PREP_WOULD_SUSPEND	2
 /* System not alive (distributed) */
 #define ERTS_DSIG_PREP_NOT_ALIVE	3
+/* Pending connection; signals can be enqueued */
+#define ERTS_DSIG_PREP_PENDING	        4
 
 ERTS_GLB_INLINE int erts_dsig_prepare(ErtsDSigData *,
-				      DistEntry *,
+				      DistEntry*,
 				      Process *,
+                                      ErtsProcLocks,
 				      ErtsDSigPrepLock,
+				      int,
 				      int);
 
 ERTS_GLB_INLINE
 void erts_schedule_dist_command(Port *, DistEntry *);
 
+int erts_auto_connect(DistEntry* dep, Process *proc, ErtsProcLocks proc_locks);
+
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
 ERTS_GLB_INLINE int 
 erts_dsig_prepare(ErtsDSigData *dsdp,
 		  DistEntry *dep,
 		  Process *proc,
+                  ErtsProcLocks proc_locks,
 		  ErtsDSigPrepLock dspl,
-		  int no_suspend)
+		  int no_suspend,
+		  int connect)
 {
-    int failure;
+    int res;
+
     if (!erts_is_alive)
 	return ERTS_DSIG_PREP_NOT_ALIVE;
-    if (!dep)
-	return ERTS_DSIG_PREP_NOT_CONNECTED;
-    if (dspl == ERTS_DSP_RWLOCK)
-	erts_de_rwlock(dep);
-    else
-	erts_de_rlock(dep);
-    if (ERTS_DE_IS_NOT_CONNECTED(dep)) {
-	failure = ERTS_DSIG_PREP_NOT_CONNECTED;
+    if (!dep) {
+        ASSERT(!connect);
+        return ERTS_DSIG_PREP_NOT_CONNECTED;
+    }
+
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    if (connect) {
+        erts_proc_lc_might_unlock(proc, proc_locks);
+    }
+#endif
+
+retry:
+    erts_de_rlock(dep);
+
+    if (ERTS_DE_IS_CONNECTED(dep)) {
+	res = ERTS_DSIG_PREP_CONNECTED;
+    }
+    else if (dep->status & ERTS_DE_SFLG_PENDING) {
+	res = ERTS_DSIG_PREP_PENDING;
+    }
+    else if (dep->status & ERTS_DE_SFLG_EXITING) {
+	res = ERTS_DSIG_PREP_NOT_CONNECTED;
+	goto fail;
+    }
+    else if (connect) {
+        ASSERT(dep->status == 0);
+        erts_de_runlock(dep);
+        if (!erts_auto_connect(dep, proc, proc_locks)) {
+            return ERTS_DSIG_PREP_NOT_ALIVE;
+        }
+	goto retry;
+    }
+    else {
+        ASSERT(dep->status == 0);
+	res = ERTS_DSIG_PREP_NOT_CONNECTED;
 	goto fail;
     }
+
     if (no_suspend) {
-        if (erts_atomic32_read_acqb(&dep->qflgs) & ERTS_DE_QFLG_BUSY) {
-	    failure = ERTS_DSIG_PREP_WOULD_SUSPEND;
+	if (erts_atomic32_read_acqb(&dep->qflgs) & ERTS_DE_QFLG_BUSY) {
+	    res = ERTS_DSIG_PREP_WOULD_SUSPEND;
 	    goto fail;
-        }
+	}
     }
     dsdp->proc = proc;
     dsdp->dep = dep;
@@ -177,15 +216,11 @@ erts_dsig_prepare(ErtsDSigData *dsdp,
     dsdp->no_suspend = no_suspend;
     if (dspl == ERTS_DSP_NO_LOCK)
 	erts_de_runlock(dep);
-    return ERTS_DSIG_PREP_CONNECTED;
+    return res;
 
  fail:
-    if (dspl == ERTS_DSP_RWLOCK)
-	erts_de_rwunlock(dep);
-    else
-	erts_de_runlock(dep);
-    return failure;
-
+    erts_de_runlock(dep);
+    return res;
 }
 
 ERTS_GLB_INLINE
@@ -332,7 +367,7 @@ struct erts_dsig_send_context {
     Eterm ctl;
     Eterm msg;
     int force_busy;
-    Uint32 pass_through_size;
+    Uint32 max_finalize_prepend;
     Uint data_size, dhdr_ext_size;
     ErtsAtomCacheMap *acmp;
     ErtsDistOutputBuf *obuf;
@@ -346,11 +381,12 @@ struct erts_dsig_send_context {
 
 typedef struct {
     int suspend;
+    int connect;
 
     Eterm ctl_heap[6];
     ErtsDSigData dsd;
-    DistEntry* dep_to_deref;
     DistEntry *dep;
+    int deref_dep;
     struct erts_dsig_send_context dss;
 
     Eterm return_term;
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
index 2960272eab..c6cc5c78b3 100644
--- a/erts/emulator/beam/erl_alloc.types
+++ b/erts/emulator/beam/erl_alloc.types
@@ -261,6 +261,7 @@ type	MINDIRECTION	FIXED_SIZE	SYSTEM		magic_indirection
 type	BINARY_FIND	SHORT_LIVED	PROCESSES	binary_find
 type  	OPEN_PORT_ENV 	TEMPORARY	SYSTEM		open_port_env
 type	CRASH_DUMP	STANDARD	SYSTEM		crash_dump
+type	DIST_TRANSCODE  SHORT_LIVED	SYSTEM		dist_transcode_context
 
 type	THR_Q_EL	STANDARD   	SYSTEM		thr_q_element
 type	THR_Q_EL_SL	FIXED_SIZE	SYSTEM		sl_thr_q_element
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 27bbf70c0b..9d05680723 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -3830,10 +3830,10 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 		    BIF_RET(res);
 		}
 	    }
-	    else if (ERTS_IS_ATOM_STR("term_to_binary_no_funs", tp[1])) {
-		Uint dflags = (DFLAG_EXTENDED_REFERENCES |
-			       DFLAG_EXTENDED_PIDS_PORTS |
-			       DFLAG_BIT_BINARIES);
+	    else if (ERTS_IS_ATOM_STR("term_to_binary_tuple_fallbacks", tp[1])) {
+		Uint dflags = (TERM_TO_BINARY_DFLAGS
+                               & ~DFLAG_EXPORT_PTR_TAG
+                               & ~DFLAG_BIT_BINARIES);
 		BIF_RET(erts_term_to_binary(BIF_P, tp[2], 0, dflags));
 	    }
 	    else if (ERTS_IS_ATOM_STR("dist_ctrl", tp[1])) {
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index c21b139cfa..d1018bab26 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -1201,11 +1201,12 @@ size_t enif_binary_to_term(ErlNifEnv *dst_env,
     Sint size;
     ErtsHeapFactory factory;
     byte *bp = (byte*) data;
+    Uint32 flags = 0;
 
-    ERTS_CT_ASSERT(ERL_NIF_BIN2TERM_SAFE == ERTS_DIST_EXT_BTT_SAFE);
-
-    if (opts & ~ERL_NIF_BIN2TERM_SAFE) {
-        return 0;
+    switch ((Uint32)opts) {
+    case 0: break;
+    case ERL_NIF_BIN2TERM_SAFE: flags = ERTS_DIST_EXT_BTT_SAFE; break;
+    default: return 0;
     }
     if ((size = erts_decode_ext_size(bp, data_sz)) < 0)
         return 0;
@@ -1217,7 +1218,7 @@ size_t enif_binary_to_term(ErlNifEnv *dst_env,
         erts_factory_dummy_init(&factory);
     }
 
-    *term = erts_decode_ext(&factory, &bp, (Uint32)opts);
+    *term = erts_decode_ext(&factory, &bp, flags);
 
     if (is_non_value(*term)) {
         return 0;
diff --git a/erts/emulator/beam/erl_node_tables.c b/erts/emulator/beam/erl_node_tables.c
index 0f3dfa797c..eaf133f5c0 100644
--- a/erts/emulator/beam/erl_node_tables.c
+++ b/erts/emulator/beam/erl_node_tables.c
@@ -39,9 +39,11 @@ erts_rwmtx_t erts_node_table_rwmtx;
 
 DistEntry *erts_hidden_dist_entries;
 DistEntry *erts_visible_dist_entries;
+DistEntry *erts_pending_dist_entries;
 DistEntry *erts_not_connected_dist_entries; /* including erts_this_dist_entry */
 Sint erts_no_of_hidden_dist_entries;
 Sint erts_no_of_visible_dist_entries;
+Sint erts_no_of_pending_dist_entries;
 Sint erts_no_of_not_connected_dist_entries; /* including erts_this_dist_entry */
 
 DistEntry *erts_this_dist_entry;
@@ -101,7 +103,9 @@ void
 erts_ref_dist_entry(DistEntry *dep)
 {
     ASSERT(dep);
-    de_refc_inc(dep, 1);
+    if (de_refc_inc_read(dep, 1) == 1) {
+        de_refc_inc(dep, 2);  /* Pending delete */
+    }
 }
 
 void
@@ -139,9 +143,7 @@ dist_table_cmp(void *dep1, void *dep2)
 static void*
 dist_table_alloc(void *dep_tmpl)
 {
-#ifdef DEBUG
     erts_aint_t refc;
-#endif
     Eterm sysname;
     Binary *bin;
     DistEntry *dep;
@@ -158,13 +160,8 @@ dist_table_alloc(void *dep_tmpl)
 
     dist_entries++;
 
-#ifdef DEBUG
-    refc =
-#else
-    (void)
-#endif
-        de_refc_dec_read(dep, -1);
-    ASSERT(refc == -1);
+    refc = de_refc_dec_read(dep, -1);
+    ASSERT(refc == -1); (void)refc;
 
     dep->prev				= NULL;
     erts_rwmtx_init_opt(&dep->rwmtx, &rwmtx_opt, "dist_entry", sysname,
@@ -202,6 +199,7 @@ dist_table_alloc(void *dep_tmpl)
     erts_port_task_handle_init(&dep->dist_cmd);
     dep->send				= NULL;
     dep->cache				= NULL;
+    dep->transcode_ctx                  = NULL;
 
     /* Link in */
 
@@ -224,6 +222,8 @@ dist_table_free(void *vdep)
 {
     DistEntry *dep = (DistEntry *) vdep;
 
+    ASSERT(de_refc_read(dep, -1) == -1);
+    ASSERT(dep->status == 0);
     ASSERT(is_nil(dep->cid));
     ASSERT(dep->nlinks == NULL);
     ASSERT(dep->node_links == NULL);
@@ -384,56 +384,92 @@ erts_dhandle_to_dist_entry(Eterm dhandle)
 }
 
 Eterm
-erts_make_dhandle(Process *c_p, DistEntry *dep)
+erts_build_dhandle(Eterm **hpp, ErlOffHeap* ohp, DistEntry *dep)
 {
-    Binary *bin;
-    Eterm *hp;
-
-    bin = ErtsDistEntry2Bin(dep);
+    Binary *bin = ErtsDistEntry2Bin(dep);
     ASSERT(bin);
     ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(bin) == erts_dist_entry_destructor);
-    hp = HAlloc(c_p, ERTS_MAGIC_REF_THING_SIZE);
-    return erts_mk_magic_ref(&hp, &c_p->off_heap, bin);
+    return erts_mk_magic_ref(hpp, ohp, bin);
+}
+
+Eterm
+erts_make_dhandle(Process *c_p, DistEntry *dep)
+{
+    Eterm *hp = HAlloc(c_p, ERTS_MAGIC_REF_THING_SIZE);
+    return erts_build_dhandle(&hp, &c_p->off_heap, dep);
 }
 
-static void try_delete_dist_entry(void *vbin);
+static void start_timer_delete_dist_entry(void *vdep);
+static void prepare_try_delete_dist_entry(void *vdep);
+static void try_delete_dist_entry(DistEntry*);
+
+static void schedule_delete_dist_entry(DistEntry* dep)
+{
+    /*
+     * Here we need thread progress to wait for other threads, that may have
+     * done lookup without refc++, to do either refc++ or drop their refs.
+     *
+     * Note that timeouts do not guarantee thread progress.
+     */
+    erts_schedule_thr_prgr_later_op(start_timer_delete_dist_entry,
+                                    dep, &dep->later_op);
+}
 
 static void
-prepare_try_delete_dist_entry(void *vbin)
+start_timer_delete_dist_entry(void *vdep)
 {
-    Binary *bin = (Binary *) vbin;
-    DistEntry *dep = ErtsBin2DistEntry(bin);
-    Uint size;
+    if (node_tab_delete_delay == 0) {
+        prepare_try_delete_dist_entry(vdep);
+    }
+    else {
+        ASSERT(node_tab_delete_delay > 0);
+        erts_start_timer_callback(node_tab_delete_delay,
+                                  prepare_try_delete_dist_entry,
+                                  vdep);
+    }
+}
+
+static void
+prepare_try_delete_dist_entry(void *vdep)
+{
+    DistEntry *dep = vdep;
     erts_aint_t refc;
 
+    /*
+     * Time has passed since we decremented refc to zero and DistEntry may
+     * have been revived. Do a fast check without table lock first.
+     */
     refc = de_refc_read(dep, 0);
-    if (refc > 0)
-        return;
-
-    size = ERTS_MAGIC_BIN_SIZE(sizeof(DistEntry));
-    erts_schedule_thr_prgr_later_cleanup_op(try_delete_dist_entry,
-                                            vbin, &dep->later_op, size);
+    if (refc == 0) {
+        try_delete_dist_entry(dep);
+    }
+    else {
+        /*
+         * Someone has done lookup and done refc++ for us.
+         */
+        refc = de_refc_dec_read(dep, 0);
+        if (refc == 0)
+            schedule_delete_dist_entry(dep);
+    }
 }
 
-static void try_delete_dist_entry(void *vbin)
+static void try_delete_dist_entry(DistEntry* dep)
 {
-    Binary *bin = (Binary *) vbin;
-    DistEntry *dep = ErtsBin2DistEntry(bin);
     erts_aint_t refc;
 
     erts_rwmtx_rwlock(&erts_dist_table_rwmtx);
     /*
      * Another thread might have looked up this dist entry after
      * we decided to delete it (refc became zero). If so, the other
-     * thread incremented refc twice. Once for the new reference
-     * and once for this thread.
+     * thread incremented refc one extra step for this thread.
      *
-     * If refc reach -1, no one has used the entry since we
-     * set up the timer. Delete the entry.
+     * If refc reach -1, no one has done lookup and no one can do lookup
+     * as we have table lock. Delete the entry.
      *
-     * If refc reach 0, the entry is currently not in use
-     * but has been used since we set up the timer. Set up a
-     * new timer.
+     * If refc reach 0, someone raced us and either
+     *  (1) did lookup with own refc++ and already released it again
+     *  (2) did lookup without own refc++
+     * Schedule new delete operation.
      *
      * If refc > 0, the entry is in use. Keep the entry.
      */
@@ -443,12 +479,7 @@ static void try_delete_dist_entry(void *vbin)
     erts_rwmtx_rwunlock(&erts_dist_table_rwmtx);
 
     if (refc == 0) {
-        if (node_tab_delete_delay == 0)
-            prepare_try_delete_dist_entry(vbin);
-        else if (node_tab_delete_delay > 0)
-            erts_start_timer_callback(node_tab_delete_delay,
-                                      prepare_try_delete_dist_entry,
-                                      vbin);
+        schedule_delete_dist_entry(dep);
     }
 }
 
@@ -462,12 +493,7 @@ int erts_dist_entry_destructor(Binary *bin)
     if (refc == -1)
         return 1; /* Allow deallocation of structure... */
 
-    if (node_tab_delete_delay == 0)
-        prepare_try_delete_dist_entry((void *) bin);
-    else if (node_tab_delete_delay > 0)
-        erts_start_timer_callback(node_tab_delete_delay,
-                                  prepare_try_delete_dist_entry,
-                                  (void *) bin);
+    schedule_delete_dist_entry(dep);
 
     return 0;
 }
@@ -498,12 +524,17 @@ erts_dist_table_size(void)
 	i++;
     ASSERT(i == erts_no_of_hidden_dist_entries);
     i = 0;
+    for(dep = erts_pending_dist_entries; dep; dep = dep->next)
+        i++;
+    ASSERT(i == erts_no_of_pending_dist_entries);
+    i = 0;
     for(dep = erts_not_connected_dist_entries; dep; dep = dep->next)
 	i++;
     ASSERT(i == erts_no_of_not_connected_dist_entries);
 
     ASSERT(dist_entries == (erts_no_of_visible_dist_entries
 			    + erts_no_of_hidden_dist_entries
+                            + erts_no_of_pending_dist_entries
 			    + erts_no_of_not_connected_dist_entries));
 #endif
 
@@ -518,43 +549,46 @@ erts_dist_table_size(void)
 void
 erts_set_dist_entry_not_connected(DistEntry *dep)
 {
+    DistEntry** head;
+
     ERTS_LC_ASSERT(erts_lc_is_de_rwlocked(dep));
     erts_rwmtx_rwlock(&erts_dist_table_rwmtx);
 
     ASSERT(dep != erts_this_dist_entry);
-    ASSERT(is_internal_port(dep->cid) || is_internal_pid(dep->cid));
-
-    if(dep->flags & DFLAG_PUBLISHED) {
-	if(dep->prev) {
-	    ASSERT(is_in_de_list(dep, erts_visible_dist_entries));
-	    dep->prev->next = dep->next;
-	}
-	else {
-	    ASSERT(erts_visible_dist_entries == dep);
-	    erts_visible_dist_entries = dep->next;
-	}
 
-	ASSERT(erts_no_of_visible_dist_entries > 0);
-	erts_no_of_visible_dist_entries--;
+    if (dep->status & ERTS_DE_SFLG_PENDING) {
+        ASSERT(is_nil(dep->cid));
+        ASSERT(erts_no_of_pending_dist_entries > 0);
+        erts_no_of_pending_dist_entries--;
+        head = &erts_pending_dist_entries;
     }
     else {
-	if(dep->prev) {
-	    ASSERT(is_in_de_list(dep, erts_hidden_dist_entries));
-	    dep->prev->next = dep->next;
-	}
-	else {
-	    ASSERT(erts_hidden_dist_entries == dep);
-	    erts_hidden_dist_entries = dep->next;
-	}
-
-	ASSERT(erts_no_of_hidden_dist_entries > 0);
-	erts_no_of_hidden_dist_entries--;
+        ASSERT(dep->status != 0);
+        ASSERT(is_internal_port(dep->cid) || is_internal_pid(dep->cid));
+        if (dep->flags & DFLAG_PUBLISHED) {
+            ASSERT(erts_no_of_visible_dist_entries > 0);
+            erts_no_of_visible_dist_entries--;
+            head = &erts_visible_dist_entries;
+        }
+        else {
+            ASSERT(erts_no_of_hidden_dist_entries > 0);
+            erts_no_of_hidden_dist_entries--;
+            head = &erts_hidden_dist_entries;
+        }
     }
 
+    if(dep->prev) {
+        ASSERT(is_in_de_list(dep, *head));
+        dep->prev->next = dep->next;
+    }
+    else {
+        ASSERT(*head == dep);
+        *head = dep->next;
+    }
     if(dep->next)
 	dep->next->prev = dep->prev;
 
-    dep->status &= ~ERTS_DE_SFLG_CONNECTED;
+    dep->status &= ~(ERTS_DE_SFLG_PENDING | ERTS_DE_SFLG_CONNECTED);
     dep->flags = 0;
     dep->prev = NULL;
     dep->cid = NIL;
@@ -570,46 +604,87 @@ erts_set_dist_entry_not_connected(DistEntry *dep)
 }
 
 void
+erts_set_dist_entry_pending(DistEntry *dep)
+{
+    ERTS_LC_ASSERT(erts_lc_is_de_rwlocked(dep));
+    erts_rwmtx_rwlock(&erts_dist_table_rwmtx);
+
+    ASSERT(dep != erts_this_dist_entry);
+    ASSERT(dep->status == 0);
+    ASSERT(is_nil(dep->cid));
+
+    if(dep->prev) {
+        ASSERT(is_in_de_list(dep, erts_not_connected_dist_entries));
+        dep->prev->next = dep->next;
+    }
+    else {
+        ASSERT(dep == erts_not_connected_dist_entries);
+        erts_not_connected_dist_entries = dep->next;
+    }
+
+    if(dep->next)
+	dep->next->prev = dep->prev;
+
+    erts_no_of_not_connected_dist_entries--;
+
+    dep->status = ERTS_DE_SFLG_PENDING;
+    dep->flags = (DFLAG_DIST_MANDATORY | DFLAG_DIST_HOPEFULLY);
+    dep->connection_id = (dep->connection_id + 1) & ERTS_DIST_CON_ID_MASK;
+
+    dep->prev = NULL;
+    dep->next = erts_pending_dist_entries;
+    if(erts_pending_dist_entries) {
+	ASSERT(erts_pending_dist_entries->prev == NULL);
+	erts_pending_dist_entries->prev = dep;
+    }
+    erts_pending_dist_entries = dep;
+    erts_no_of_pending_dist_entries++;
+    erts_rwmtx_rwunlock(&erts_dist_table_rwmtx);
+}
+
+void
 erts_set_dist_entry_connected(DistEntry *dep, Eterm cid, Uint flags)
 {
+    erts_aint32_t set_qflgs;
+
     ERTS_LC_ASSERT(erts_lc_is_de_rwlocked(dep));
     erts_rwmtx_rwlock(&erts_dist_table_rwmtx);
 
     ASSERT(dep != erts_this_dist_entry);
     ASSERT(is_nil(dep->cid));
+    ASSERT(dep->status & ERTS_DE_SFLG_PENDING);
     ASSERT(is_internal_port(cid) || is_internal_pid(cid));
 
     if(dep->prev) {
-	ASSERT(is_in_de_list(dep, erts_not_connected_dist_entries));
+	ASSERT(is_in_de_list(dep, erts_pending_dist_entries));
 	dep->prev->next = dep->next;
     }
     else {
-	ASSERT(erts_not_connected_dist_entries == dep);
-	erts_not_connected_dist_entries = dep->next;
+	ASSERT(erts_pending_dist_entries == dep);
+	erts_pending_dist_entries = dep->next;
     }
 
     if(dep->next)
 	dep->next->prev = dep->prev;
 
-    ASSERT(erts_no_of_not_connected_dist_entries > 0);
-    erts_no_of_not_connected_dist_entries--;
+    ASSERT(erts_no_of_pending_dist_entries > 0);
+    erts_no_of_pending_dist_entries--;
 
+    dep->status &= ~ERTS_DE_SFLG_PENDING;
     dep->status |= ERTS_DE_SFLG_CONNECTED;
-    dep->flags = flags;
+    dep->flags = flags & ~DFLAG_NO_MAGIC;
     dep->cid = cid;
     erts_atomic_set_nob(&dep->input_handler,
                             (erts_aint_t) cid);
 
-    dep->connection_id++;
-    dep->connection_id &= ERTS_DIST_EXT_CON_ID_MASK;
     dep->prev = NULL;
 
     erts_atomic64_set_nob(&dep->in, 0);
     erts_atomic64_set_nob(&dep->out, 0);
-    erts_atomic32_set_nob(&dep->qflgs,
-                          (is_internal_port(cid)
-                           ? ERTS_DE_QFLG_PORT_CTRL
-                           : ERTS_DE_QFLG_PROC_CTRL));
+    set_qflgs = (is_internal_port(cid) ?
+                 ERTS_DE_QFLG_PORT_CTRL : ERTS_DE_QFLG_PROC_CTRL);
+    erts_atomic32_read_bor_nob(&dep->qflgs, set_qflgs);
+
     if(flags & DFLAG_PUBLISHED) {
 	dep->next = erts_visible_dist_entries;
 	if(erts_visible_dist_entries) {
@@ -929,9 +1004,11 @@ void erts_init_node_tables(int dd_sec)
 
     erts_hidden_dist_entries				= NULL;
     erts_visible_dist_entries				= NULL;
+    erts_pending_dist_entries			        = NULL;
     erts_not_connected_dist_entries			= NULL;
     erts_no_of_hidden_dist_entries			= 0;
     erts_no_of_visible_dist_entries			= 0;
+    erts_no_of_pending_dist_entries			= 0;
     erts_no_of_not_connected_dist_entries		= 0;
 
     node_tmpl.sysname = am_Noname;
@@ -1057,6 +1134,7 @@ typedef struct {
 typedef struct dist_referrer_ {
     struct dist_referrer_ *next;
     int heap_ref;
+    int ets_ref;
     int node_ref;
     int ctrl_ref;
     int system_ref;
@@ -1175,10 +1253,11 @@ insert_dist_referrer(ReferredDist *referred_dist,
 	else {
 	    Uint *hp = &drp->id_heap[0];
 	    ASSERT(is_tuple(id));
-	    drp->id = copy_struct(id, size_object(id), &hp, NULL);
+            drp->id = copy_struct(id, size_object(id), &hp, NULL);
 	}
 	drp->creation = creation;
 	drp->heap_ref = 0;
+        drp->ets_ref = 0;
 	drp->node_ref = 0;
 	drp->ctrl_ref = 0;
 	drp->system_ref = 0;
@@ -1188,6 +1267,7 @@ insert_dist_referrer(ReferredDist *referred_dist,
     case NODE_REF:	drp->node_ref++;	break;
     case CTRL_REF:	drp->ctrl_ref++;	break;
     case HEAP_REF:	drp->heap_ref++;	break;
+    case ETS_REF:	drp->ets_ref++;	        break;
     case SYSTEM_REF:	drp->system_ref++;	break;
     default:		ASSERT(0);
     }
@@ -1300,6 +1380,11 @@ insert_offheap2(ErlOffHeap *oh, void *arg)
     (((Bin)->intern.flags & BIN_FLAG_MAGIC)                             \
      && ERTS_MAGIC_BIN_DESTRUCTOR((Bin)) == erts_dist_entry_destructor)
 
+#define IsSendCtxBinary(Bin)                                            \
+    (((Bin)->intern.flags & BIN_FLAG_MAGIC)                             \
+     && ERTS_MAGIC_BIN_DESTRUCTOR((Bin)) == erts_dsend_context_dtor)
+
+
 static void
 insert_offheap(ErlOffHeap *oh, int type, Eterm id)
 {
@@ -1336,7 +1421,12 @@ insert_offheap(ErlOffHeap *oh, int type, Eterm id)
 		    inserted_bins = nib;
 		    UnUseTmpHeapNoproc(BIG_UINT_HEAP_SIZE);
 		}
-	    }		
+	    }
+            else if (IsSendCtxBinary(u.mref->mb)) {
+                ErtsSendContext* ctx = ERTS_MAGIC_BIN_DATA(u.mref->mb);
+                if (ctx->deref_dep)
+                    insert_dist_entry(ctx->dep, type, id, 0);
+            }
 	    break;
 	case REFC_BINARY_SUBTAG:
 	case FUN_SUBTAG:
@@ -1463,9 +1553,9 @@ insert_delayed_delete_node(void *state,
 }
 
 static void
-insert_thr_prgr_delete_dist_entry(void *arg, ErtsThrPrgrVal thr_prgr, void *vbin)
+insert_thr_prgr_delete_dist_entry(void *arg, ErtsThrPrgrVal thr_prgr, void *vdep)
 {
-    DistEntry *dep = ErtsBin2DistEntry(vbin);
+    DistEntry *dep = vdep;
     Eterm heap[3];
     insert_dist_entry(dep,
 		      SYSTEM_REF,
@@ -1476,9 +1566,9 @@ insert_thr_prgr_delete_dist_entry(void *arg, ErtsThrPrgrVal thr_prgr, void *vbin
 static void
 insert_delayed_delete_dist_entry(void *state,
 				 ErtsMonotonicTime timeout_pos,
-				 void *vbin)
+				 void *vdep)
 {
-    DistEntry *dep = ErtsBin2DistEntry(vbin);
+    DistEntry *dep = vdep;
     Eterm heap[3];
     insert_dist_entry(dep,
 		      SYSTEM_REF,
@@ -1520,7 +1610,7 @@ setup_reference_table(void)
     erts_debug_callback_timer_foreach(prepare_try_delete_dist_entry,
 				      insert_delayed_delete_dist_entry,
 				      NULL);
-    erts_debug_later_op_foreach(try_delete_dist_entry,
+    erts_debug_later_op_foreach(start_timer_delete_dist_entry,
                                 insert_thr_prgr_delete_dist_entry,
                                 NULL);
 
@@ -1686,6 +1776,15 @@ setup_reference_table(void)
 	    insert_monitors(dep->monitors, dep->sysname);
     }
 
+    for(dep = erts_pending_dist_entries; dep; dep = dep->next) {
+        if(dep->nlinks)
+            insert_links2(dep->nlinks, dep->sysname);
+        if(dep->node_links)
+            insert_links(dep->node_links, dep->sysname);
+        if(dep->monitors)
+            insert_monitors(dep->monitors, dep->sysname);
+    }
+
     /* Not connected dist entries should not have any links,
        but inspect them anyway */
     for(dep = erts_not_connected_dist_entries; dep; dep = dep->next) {
@@ -1855,6 +1954,10 @@ reference_table_term(Uint **hpp, ErlOffHeap *ohp, Uint *szp)
 		tup = MK_2TUP(AM_heap, MK_UINT(drp->heap_ref));
 		drl = MK_CONS(tup, drl);
 	    }
+            if(drp->ets_ref) {
+                tup = MK_2TUP(AM_ets, MK_UINT(drp->ets_ref));
+                drl = MK_CONS(tup, drl);
+            }
 	    if(drp->system_ref) {
 		tup = MK_2TUP(AM_system, MK_UINT(drp->system_ref));
 		drl = MK_CONS(tup, drl);
@@ -1871,12 +1974,17 @@ reference_table_term(Uint **hpp, ErlOffHeap *ohp, Uint *szp)
 	    else if (is_tuple(drp->id)) {
 		Eterm *t;
 		ASSERT(drp->system_ref && !drp->node_ref
-		       && !drp->ctrl_ref && !drp->heap_ref);
+		       && !drp->ctrl_ref && !drp->heap_ref && !drp->ets_ref);
 		t = tuple_val(drp->id);
 		ASSERT(2 == arityval(t[0]));
 		tup = MK_2TUP(t[1], t[2]);
 	    }
-	    else {
+	    else if (drp->ets_ref) {
+                ASSERT(!drp->heap_ref && !drp->node_ref &&
+                       !drp->ctrl_ref && !drp->system_ref);
+                tup = MK_2TUP(AM_ets, drp->id);
+            }
+            else {
 		ASSERT(!drp->ctrl_ref && drp->node_ref);
 		ASSERT(is_atom(drp->id));
 		tup = MK_2TUP(drp->id, MK_UINT(drp->creation));
diff --git a/erts/emulator/beam/erl_node_tables.h b/erts/emulator/beam/erl_node_tables.h
index ee8277b5ea..8d29c83e15 100644
--- a/erts/emulator/beam/erl_node_tables.h
+++ b/erts/emulator/beam/erl_node_tables.h
@@ -57,11 +57,9 @@
  
 #define ERST_INTERNAL_CHANNEL_NO 0
 
-#define ERTS_DE_SFLG_CONNECTED			(((Uint32) 1) <<  0)
-#define ERTS_DE_SFLG_EXITING			(((Uint32) 1) <<  1)
-
-#define ERTS_DE_SFLGS_ALL			(ERTS_DE_SFLG_CONNECTED \
-						 | ERTS_DE_SFLG_EXITING)
+#define ERTS_DE_SFLG_PENDING			(((Uint32) 1) <<  0)
+#define ERTS_DE_SFLG_CONNECTED			(((Uint32) 1) <<  1)
+#define ERTS_DE_SFLG_EXITING			(((Uint32) 1) <<  2)
 
 #define ERTS_DE_QFLG_BUSY			(((erts_aint32_t) 1) <<  0)
 #define ERTS_DE_QFLG_EXIT			(((erts_aint32_t) 1) <<  1)
@@ -85,10 +83,12 @@ typedef struct ErtsDistOutputBuf_ ErtsDistOutputBuf;
 struct ErtsDistOutputBuf_ {
 #ifdef DEBUG
     Uint dbg_pattern;
+    byte *alloc_endp;
 #endif
     ErtsDistOutputBuf *next;
     byte *extp;
     byte *ext_endp;
+    byte *msg_start;
     byte data[1];
 };
 
@@ -109,8 +109,6 @@ struct ErtsProcList_;
  *   unlock mutexes with higher numbers before mutexes with higher numbers.
  */
 
-struct erl_link;
-
 typedef struct dist_entry_ {
     HashBucket hash_bucket;     /* Hash bucket */
     struct dist_entry_ *next;	/* Next entry in dist_table (not sorted) */
@@ -159,6 +157,8 @@ typedef struct dist_entry_ {
     struct cache* cache;	/* The atom cache */
 
     ErtsThrPrgrLaterOp later_op;
+
+    struct transcode_context* transcode_ctx;
 } DistEntry;
 
 typedef struct erl_node_ {
@@ -177,9 +177,11 @@ extern erts_rwmtx_t erts_node_table_rwmtx;
 
 extern DistEntry *erts_hidden_dist_entries;
 extern DistEntry *erts_visible_dist_entries;
+extern DistEntry *erts_pending_dist_entries;
 extern DistEntry *erts_not_connected_dist_entries;
 extern Sint erts_no_of_hidden_dist_entries;
 extern Sint erts_no_of_visible_dist_entries;
+extern Sint erts_no_of_pending_dist_entries;
 extern Sint erts_no_of_not_connected_dist_entries;
 
 extern DistEntry *erts_this_dist_entry;
@@ -195,6 +197,7 @@ void erts_schedule_delete_dist_entry(DistEntry *);
 Uint erts_dist_table_size(void);
 void erts_dist_table_info(fmtfn_t, void *);
 void erts_set_dist_entry_not_connected(DistEntry *);
+void erts_set_dist_entry_pending(DistEntry *);
 void erts_set_dist_entry_connected(DistEntry *, Eterm, Uint);
 ErlNode *erts_find_or_insert_node(Eterm, Uint32);
 void erts_schedule_delete_node(ErlNode *);
@@ -210,6 +213,7 @@ int erts_lc_is_de_rlocked(DistEntry *);
 #endif
 int erts_dist_entry_destructor(Binary *bin);
 DistEntry *erts_dhandle_to_dist_entry(Eterm dhandle);
+Eterm erts_build_dhandle(Eterm **hpp, ErlOffHeap*, DistEntry*);
 Eterm erts_make_dhandle(Process *c_p, DistEntry *dep);
 void erts_ref_dist_entry(DistEntry *dep);
 void erts_deref_dist_entry(DistEntry *dep);
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 3c0a126fe2..a807d60ec7 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -12659,9 +12659,11 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 		erts_de_links_unlock(dep);
 		if (rmon) {
 		    ErtsDSigData dsd;
-		    int code = erts_dsig_prepare(&dsd, dep, NULL,
-						 ERTS_DSP_NO_LOCK, 0);
-		    if (code == ERTS_DSIG_PREP_CONNECTED) {
+		    int code = erts_dsig_prepare(&dsd, dep, NULL, 0,
+						 ERTS_DSP_NO_LOCK, 0, 0);
+		    if (code == ERTS_DSIG_PREP_CONNECTED ||
+                        code == ERTS_DSIG_PREP_PENDING) {
+
 			code = erts_dsig_send_demonitor(&dsd,
 							rmon->u.pid,
 							mon->name,
@@ -12705,9 +12707,11 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 		    erts_de_links_unlock(dep);
 		    if (rmon) {
 			ErtsDSigData dsd;
-			int code = erts_dsig_prepare(&dsd, dep, NULL,
-						     ERTS_DSP_NO_LOCK, 0);
-			if (code == ERTS_DSIG_PREP_CONNECTED) {
+			int code = erts_dsig_prepare(&dsd, dep, NULL, 0,
+						     ERTS_DSP_NO_LOCK, 0, 0);
+			if (code == ERTS_DSIG_PREP_CONNECTED ||
+                            code == ERTS_DSIG_PREP_PENDING) {
+
 			    code = erts_dsig_send_demonitor(&dsd,
 							    rmon->u.pid,
 							    mon->u.pid,
@@ -12764,8 +12768,8 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 		erts_de_links_unlock(dep);
 		if (rmon) {
 		    ErtsDSigData dsd;
-		    int code = erts_dsig_prepare(&dsd, dep, NULL,
-						 ERTS_DSP_NO_LOCK, 0);
+		    int code = erts_dsig_prepare(&dsd, dep, NULL, 0,
+						 ERTS_DSP_NO_LOCK, 0, 0);
 		    if (code == ERTS_DSIG_PREP_CONNECTED) {
 			code = erts_dsig_send_m_exit(&dsd,
 						     mon->u.pid,
@@ -12887,14 +12891,18 @@ static void doit_exit_link(ErtsLink *lnk, void *vpcontext)
 		int code;
 		ErtsDistLinkData dld;
 		erts_remove_dist_link(&dld, p->common.id, item, dep);
-		erts_proc_lock(p, ERTS_PROC_LOCK_MAIN);
-		code = erts_dsig_prepare(&dsd, dep, p, ERTS_DSP_NO_LOCK, 0);
-		if (code == ERTS_DSIG_PREP_CONNECTED) {
-		    code = erts_dsig_send_exit_tt(&dsd, p->common.id, item,
-						  reason, SEQ_TRACE_TOKEN(p));
-		    ASSERT(code == ERTS_DSIG_SEND_OK);
-		}
-		erts_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
+                if (dld.d_lnk) {
+                    erts_proc_lock(p, ERTS_PROC_LOCK_MAIN);
+                    code = erts_dsig_prepare(&dsd, dep, p, 0, ERTS_DSP_NO_LOCK, 0, 0);
+                    if (code == ERTS_DSIG_PREP_CONNECTED ||
+                        code == ERTS_DSIG_PREP_PENDING) {
+
+                        code = erts_dsig_send_exit_tt(&dsd, p->common.id, item,
+                                                      reason, SEQ_TRACE_TOKEN(p));
+                        ASSERT(code == ERTS_DSIG_SEND_OK);
+                    }
+                    erts_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
+                }
 		erts_destroy_dist_link(&dld);
 	    }
 	}
diff --git a/erts/emulator/beam/erl_thr_progress.h b/erts/emulator/beam/erl_thr_progress.h
index fa936b5707..8c029bcf99 100644
--- a/erts/emulator/beam/erl_thr_progress.h
+++ b/erts/emulator/beam/erl_thr_progress.h
@@ -28,7 +28,7 @@
  * Author: 	Rickard Green
  */
 
-#if !defined(ERL_THR_PROGRESS_H__TSD_TYPE__)
+#ifndef ERL_THR_PROGRESS_H__TSD_TYPE__
 #define ERL_THR_PROGRESS_H__TSD_TYPE__
 
 #include "sys.h"
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index 6666c42778..f2e6399ad7 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -122,6 +122,9 @@ static int encode_size_struct_int(struct TTBSizeContext_*, ErtsAtomCacheMap *acm
 
 static Export binary_to_term_trap_export;
 static BIF_RETTYPE binary_to_term_trap_1(BIF_ALIST_1);
+static Sint transcode_dist_obuf(ErtsDistOutputBuf*, DistEntry*, Uint32 dflags, Sint reds);
+
+
 
 void erts_init_external(void) {
     erts_init_trap_export(&term_to_binary_trap_export,
@@ -220,23 +223,10 @@ erts_destroy_atom_cache_map(ErtsAtomCacheMap *acmp)
 static ERTS_INLINE void
 insert_acache_map(ErtsAtomCacheMap *acmp, Eterm atom, Uint32 dflags)
 {
-    /*
-     * If the receiver do not understand utf8 atoms
-     * and this atom cannot be represented in latin1,
-     * we are not allowed to cache it.
-     *
-     * In this case all atoms are assumed to have
-     * latin1 encoding in the cache. By refusing it
-     * in the cache we will instead encode it using
-     * ATOM_UTF8_EXT/SMALL_ATOM_UTF8_EXT which the
-     * receiver do not recognize and tear down the
-     * connection.
-     */
-    if (acmp && acmp->sz < ERTS_MAX_INTERNAL_ATOM_CACHE_ENTRIES
-	&& ((dflags & DFLAG_UTF8_ATOMS)
-	    || atom_tab(atom_val(atom))->latin1_chars >= 0)) {
+    if (acmp && acmp->sz < ERTS_MAX_INTERNAL_ATOM_CACHE_ENTRIES) {
 	int ix;
 	ASSERT(acmp->hdr_sz < 0);
+        ASSERT(dflags & DFLAG_UTF8_ATOMS);
 	ix = atom2cix(atom);
 	if (acmp->cache[ix].iix < 0) {
 	    acmp->cache[ix].iix = acmp->sz;
@@ -256,9 +246,7 @@ get_iix_acache_map(ErtsAtomCacheMap *acmp, Eterm atom, Uint32 dflags)
 	ASSERT(is_atom(atom));
 	ix = atom2cix(atom);
 	if (acmp->cache[ix].iix < 0) {
-	    ASSERT(acmp->sz == ERTS_MAX_INTERNAL_ATOM_CACHE_ENTRIES
-		   || (!(dflags & DFLAG_UTF8_ATOMS)
-		       && atom_tab(atom_val(atom))->latin1_chars < 0));
+	    ASSERT(acmp->sz == ERTS_MAX_INTERNAL_ATOM_CACHE_ENTRIES);
 	    return -1;
 	}
 	else {
@@ -272,7 +260,6 @@ void
 erts_finalize_atom_cache_map(ErtsAtomCacheMap *acmp, Uint32 dflags)
 {
     if (acmp) {
-	int utf8_atoms = (int) (dflags & DFLAG_UTF8_ATOMS);
 	int long_atoms = 0; /* !0 if one or more atoms are longer than 255. */
 	int i;
 	int sz;
@@ -283,6 +270,7 @@ erts_finalize_atom_cache_map(ErtsAtomCacheMap *acmp, Uint32 dflags)
 	    + 1 /* number of internal cache entries */
 	    ;
 	int min_sz;
+        ASSERT(dflags & DFLAG_UTF8_ATOMS);
 	ASSERT(acmp->hdr_sz < 0);
 	/* Make sure cache update instructions fit */
 	min_sz = fix_sz+(2+4)*acmp->sz;
@@ -294,7 +282,7 @@ erts_finalize_atom_cache_map(ErtsAtomCacheMap *acmp, Uint32 dflags)
 	    atom = acmp->cache[acmp->cix[i]].atom;
 	    ASSERT(is_atom(atom));
 	    a = atom_tab(atom_val(atom));
-	    len = (int) (utf8_atoms ? a->len : a->latin1_chars);
+	    len = (int) a->len;
 	    ASSERT(len >= 0);
 	    if (!long_atoms && len > 255)
 		long_atoms = 1;
@@ -364,18 +352,62 @@ byte *erts_encode_ext_dist_header_setup(byte *ctl_ext, ErtsAtomCacheMap *acmp)
     }
 }
 
-byte *erts_encode_ext_dist_header_finalize(byte *ext, ErtsAtomCache *cache, Uint32 dflags)
+
+#define PASS_THROUGH 'p'
+
+Sint erts_encode_ext_dist_header_finalize(ErtsDistOutputBuf* ob,
+                                          DistEntry* dep,
+                                          Uint32 dflags,
+                                          Sint reds)
 {
     byte *ip;
     byte instr_buf[(2+4)*ERTS_ATOM_CACHE_SIZE];
     int ci, sz;
     byte dist_hdr_flags;
     int long_atoms;
-    int utf8_atoms = (int) (dflags & DFLAG_UTF8_ATOMS);
-    register byte *ep = ext;
-    ASSERT(ep[0] == VERSION_MAGIC);
-    if (ep[1] != DIST_HEADER)
-	return ext;
+    register byte *ep = ob->extp;
+    ASSERT(dflags & DFLAG_UTF8_ATOMS);
+
+    /*
+     * The buffer can have different layouts at this point depending on
+     * what was known when encoded:
+     *
+     * Pending connection: CtrlTerm [, MsgTerm]
+     * With atom cache   : VERSION_MAGIC, DIST_HEADER, ..., CtrlTerm [, MsgTerm]
+     * No atom cache     : VERSION_MAGIC, CtrlTerm [, VERSION_MAGIC, MsgTerm]
+     */
+
+    if (ep[0] != VERSION_MAGIC || dep->transcode_ctx) {
+        /*
+         * Was encoded without atom cache toward pending connection.
+         */
+        ASSERT(ep[0] == SMALL_TUPLE_EXT || ep[0] == LARGE_TUPLE_EXT);
+
+        if (~dflags & (DFLAG_BIT_BINARIES | DFLAG_EXPORT_PTR_TAG
+                       | DFLAG_DIST_HDR_ATOM_CACHE)) {
+            reds = transcode_dist_obuf(ob, dep, dflags, reds);
+            if (reds < 0)
+                return reds;
+            ep = ob->extp;
+        }
+        if (dflags & DFLAG_DIST_HDR_ATOM_CACHE) {
+            /*
+             * Encoding was done without atom caching but receiver expects
+             * a dist header, so we prepend an empty one.
+             */
+            *--ep = 0; /* NumberOfAtomCacheRefs */
+            *--ep = DIST_HEADER;
+            *--ep = VERSION_MAGIC;
+        }
+        goto done;
+    }
+    else if (ep[1] != DIST_HEADER) {
+        ASSERT(ep[1] == SMALL_TUPLE_EXT || ep[1] == LARGE_TUPLE_EXT);
+        ASSERT(!(dflags & DFLAG_DIST_HDR_ATOM_CACHE));
+        /* Node without atom cache, 'pass through' needed */
+        *--ep = PASS_THROUGH;
+        goto done;
+    }
 
     dist_hdr_flags = ep[2];
     long_atoms = ERTS_DIST_HDR_LONG_ATOMS_FLG & ((int) dist_hdr_flags);
@@ -403,6 +435,7 @@ byte *erts_encode_ext_dist_header_finalize(byte *ext, ErtsAtomCache *cache, Uint
 			 / sizeof(Uint32))+1];
 	register Uint32 flgs;
 	int iix, flgs_bytes, flgs_buf_ix, used_half_bytes;
+        ErtsAtomCache* cache = dep->cache;
 #ifdef DEBUG
 	int tot_used_half_bytes;
 #endif
@@ -445,17 +478,9 @@ byte *erts_encode_ext_dist_header_finalize(byte *ext, ErtsAtomCache *cache, Uint
 		Atom *a;
 		cache->out_arr[cix] = atom;
 		a = atom_tab(atom_val(atom));
-		if (utf8_atoms) {
-		    sz = a->len;
-		    ep -= sz;
-		    sys_memcpy((void *) ep, (void *) a->name, sz);
-		}
-		else {
-		    ASSERT(0 <= a->latin1_chars && a->latin1_chars <= MAX_ATOM_CHARACTERS);
-		    ep -= a->latin1_chars;
-		    sz = erts_utf8_to_latin1(ep, a->name, a->len);
-		    ASSERT(a->latin1_chars == sz);
-		}
+                sz = a->len;
+                ep -= sz;
+                sys_memcpy((void *) ep, (void *) a->name, sz);
 		if (long_atoms) {
 		    ep -= 2;
 		    put_int16(sz, ep);
@@ -502,12 +527,16 @@ byte *erts_encode_ext_dist_header_finalize(byte *ext, ErtsAtomCache *cache, Uint
 		break;
 	    }
 	}
+        reds -= 3; /*was ERTS_PORT_REDS_DIST_CMD_FINALIZE*/
     }
     --ep;
     put_int8(ci, ep);
     *--ep = DIST_HEADER;
     *--ep = VERSION_MAGIC;
-    return ep;
+done:
+    ob->extp = ep;
+    ASSERT(&ob->data[0] <= ob->extp && ob->extp < ob->ext_endp);
+    return reds < 0 ? 0 : reds;
 }
 
 int erts_encode_dist_ext_size(Eterm term, Uint32 flags, ErtsAtomCacheMap *acmp,
@@ -518,7 +547,7 @@ int erts_encode_dist_ext_size(Eterm term, Uint32 flags, ErtsAtomCacheMap *acmp,
 	return -1;
     } else {
 #ifndef ERTS_DEBUG_USE_DIST_SEP
-	if (!(flags & DFLAG_DIST_HDR_ATOM_CACHE))
+	if (!(flags & (DFLAG_DIST_HDR_ATOM_CACHE | DFLAG_NO_MAGIC)))
 #endif
 	    sz++ /* VERSION_MAGIC */;
 
@@ -534,7 +563,7 @@ int erts_encode_dist_ext_size_int(Eterm term, struct erts_dsig_send_context* ctx
 	return -1;
     } else {
 #ifndef ERTS_DEBUG_USE_DIST_SEP
-	if (!(ctx->flags & DFLAG_DIST_HDR_ATOM_CACHE))
+	if (!(ctx->flags & (DFLAG_DIST_HDR_ATOM_CACHE | DFLAG_NO_MAGIC)))
 #endif
 	    sz++ /* VERSION_MAGIC */;
 
@@ -566,7 +595,7 @@ int erts_encode_dist_ext(Eterm term, byte **ext, Uint32 flags, ErtsAtomCacheMap
 {
     if (!ctx || !ctx->wstack.wstart) {
     #ifndef ERTS_DEBUG_USE_DIST_SEP
-	if (!(flags & DFLAG_DIST_HDR_ATOM_CACHE))
+	if (!(flags & (DFLAG_DIST_HDR_ATOM_CACHE | DFLAG_NO_MAGIC)))
     #endif
 	    *(*ext)++ = VERSION_MAGIC;
     }
@@ -641,7 +670,7 @@ erts_prepare_dist_ext(ErtsDistExternal *edep,
 #endif
 
     register byte *ep = ext;
-    int utf8_atoms = (int) (dep->flags & DFLAG_UTF8_ATOMS);
+    ASSERT(dep->flags & DFLAG_UTF8_ATOMS);
 
     edep->heap_size = -1;
     edep->ext_endp = ext+size;
@@ -667,17 +696,16 @@ erts_prepare_dist_ext(ErtsDistExternal *edep,
 
     erts_de_rlock(dep);
 
-    if ((dep->status & (ERTS_DE_SFLG_EXITING|ERTS_DE_SFLG_CONNECTED))
-        != ERTS_DE_SFLG_CONNECTED) {
+    if (dep->status != ERTS_DE_SFLG_CONNECTED &&
+	dep->status != ERTS_DE_SFLG_PENDING) {
         erts_de_runlock(dep);
         return ERTS_PREP_DIST_EXT_CLOSED;
     }
-
     if (dep->flags & DFLAG_DIST_HDR_ATOM_CACHE)
         edep->flags |= ERTS_DIST_EXT_DFLAG_HDR;
 
     *connection_id = dep->connection_id;
-    edep->flags |= (dep->connection_id & ERTS_DIST_EXT_CON_ID_MASK);
+    edep->connection_id = dep->connection_id;
 
     if (ep[1] != DIST_HEADER) {
 	if (edep->flags & ERTS_DIST_EXT_DFLAG_HDR)
@@ -804,9 +832,7 @@ erts_prepare_dist_ext(ErtsDistExternal *edep,
 		    CHKSIZE(len);
 		    atom = erts_atom_put((byte *) ep,
 					 len,
-					 (utf8_atoms
-					  ? ERTS_ATOM_ENC_UTF8
-					  : ERTS_ATOM_ENC_LATIN1),
+                                         ERTS_ATOM_ENC_UTF8,
 					 0);
 		    if (is_non_value(atom))
 			ERTS_EXT_HDR_FAIL;
@@ -893,7 +919,7 @@ bad_dist_ext(ErtsDistExternal *edep)
 		erts_dsprintf(dsbufp, ", %d=%T", i, edep->attab.atom[i]);
 	}
 	erts_send_warning_to_logger_nogl(dsbufp);
-	erts_kill_dist_connection(dep, ERTS_DIST_EXT_CON_ID(edep));
+	erts_kill_dist_connection(dep, edep->connection_id);
     }
 }
 
@@ -2135,7 +2161,7 @@ enc_atom(ErtsAtomCacheMap *acmp, Eterm atom, byte *ep, Uint32 dflags)
 {
     int iix;
     int len;
-    int utf8_atoms = (int) (dflags & DFLAG_UTF8_ATOMS);
+    const int utf8_atoms = (int) (dflags & DFLAG_UTF8_ATOMS);
 
     ASSERT(is_atom(atom));
 
@@ -2530,8 +2556,6 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 	    break;
 	}
 
-    L_jump_start:
-
 	if (ctx && --r <= 0) {
 	    *reds = 0;
 	    ctx->obj = obj;
@@ -2539,6 +2563,8 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 	    WSTACK_SAVE(s, &ctx->wstack);
 	    return -1;
 	}
+
+    L_jump_start:
 	switch(tag_val_def(obj)) {
 	case NIL_DEF:
 	    *ep++ = NIL_EXT;
@@ -2903,62 +2929,27 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 		ErlFunThing* funp = (ErlFunThing *) fun_val(obj);
 		int ei;
 
-		if ((dflags & DFLAG_NEW_FUN_TAGS) != 0) {
-		    *ep++ = NEW_FUN_EXT;
-		    WSTACK_PUSH2(s, ENC_PATCH_FUN_SIZE,
-				 (UWord) ep); /* Position for patching in size */
-		    ep += 4;
-		    *ep = funp->arity;
-		    ep += 1;
-		    sys_memcpy(ep, funp->fe->uniq, 16);
-		    ep += 16;
-		    put_int32(funp->fe->index, ep);
-		    ep += 4;
-		    put_int32(funp->num_free, ep);
-		    ep += 4;
-		    ep = enc_atom(acmp, funp->fe->module, ep, dflags);
-		    ep = enc_term(acmp, make_small(funp->fe->old_index), ep, dflags, off_heap);
-		    ep = enc_term(acmp, make_small(funp->fe->old_uniq), ep, dflags, off_heap);
-		    ep = enc_pid(acmp, funp->creator, ep, dflags);
-		} else {
-		    /*
-		     * Communicating with an obsolete erl_interface or
-		     * jinterface node. Convert the fun to a tuple to
-		     * avoid crasching.
-		     */
-		
-		    /* Tag, arity */
-		    *ep++ = SMALL_TUPLE_EXT;
-		    put_int8(5, ep);
-		    ep += 1;
-		
-		    /* 'fun' */
-		    ep = enc_atom(acmp, am_fun, ep, dflags);
-		
-		    /* Module name */
-		    ep = enc_atom(acmp, funp->fe->module, ep, dflags);
-		
-		    /* Index, Uniq */
-		    *ep++ = INTEGER_EXT;
-		    put_int32(funp->fe->old_index, ep);
-		    ep += 4;
-		    *ep++ = INTEGER_EXT;
-		    put_int32(funp->fe->old_uniq, ep);
-		    ep += 4;
-		
-		    /* Environment sub-tuple arity */
-		    ASSERT(funp->num_free < MAX_ARG);
-		    *ep++ = SMALL_TUPLE_EXT;
-		    put_int8(funp->num_free, ep);
-		    ep += 1;
-		}
-		for (ei = funp->num_free-1; ei > 0; ei--) {
+		ASSERT(dflags & DFLAG_NEW_FUN_TAGS);
+                *ep++ = NEW_FUN_EXT;
+                WSTACK_PUSH2(s, ENC_PATCH_FUN_SIZE,
+                             (UWord) ep); /* Position for patching in size */
+                ep += 4;
+                *ep = funp->arity;
+                ep += 1;
+                sys_memcpy(ep, funp->fe->uniq, 16);
+                ep += 16;
+                put_int32(funp->fe->index, ep);
+                ep += 4;
+                put_int32(funp->num_free, ep);
+                ep += 4;
+                ep = enc_atom(acmp, funp->fe->module, ep, dflags);
+                ep = enc_term(acmp, make_small(funp->fe->old_index), ep, dflags, off_heap);
+                ep = enc_term(acmp, make_small(funp->fe->old_uniq), ep, dflags, off_heap);
+                ep = enc_pid(acmp, funp->creator, ep, dflags);
+
+		for (ei = funp->num_free-1; ei >= 0; ei--) {
 		    WSTACK_PUSH2(s, ENC_TERM, (UWord) funp->env[ei]);
 		}
-		if (funp->num_free != 0) {
-		    obj = funp->env[0];
-		    goto L_jump_start;
-		}
 	    }
 	    break;
 	}
@@ -3296,6 +3287,7 @@ dec_term_atom_common:
             n--;
 	    if (ctx) {
                 if (reds < n) {
+                    ASSERT(reds > 0);
 		    ctx->state = B2TDecodeList;
 		    ctx->u.dc.remaining_n = n - reds;
 		    n = reds;
@@ -4306,24 +4298,12 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 	    {
 		ErlFunThing* funp = (ErlFunThing *) fun_val(obj);
 		
-		if ((dflags & DFLAG_NEW_FUN_TAGS) != 0) {
-		    result += 20+1+1+4;	/* New ID + Tag */
-		    result += 4; /* Length field (number of free variables */
-		    result += encode_size_struct2(acmp, funp->creator, dflags);
-		    result += encode_size_struct2(acmp, funp->fe->module, dflags);
-		    result += 2 * (1+4);	/* Index, Uniq */
-		} else {
-		    /*
-		     * Size when fun is mapped to a tuple.
-		     */
-		    result += 1 + 1; /* Tuple tag, arity */
-		    result += 1 + 1 + 2 +
-			atom_tab(atom_val(am_fun))->len; /* 'fun' */
-		    result += 1 + 1 + 2 +
-			atom_tab(atom_val(funp->fe->module))->len; /* Module name */
-		    result += 2 * (1 + 4); /* Index + Uniq */
-		    result += 1 + (funp->num_free < 0x100 ? 1 : 4);
-		}
+                ASSERT(dflags & DFLAG_NEW_FUN_TAGS);
+                result += 20+1+1+4;	/* New ID + Tag */
+                result += 4; /* Length field (number of free variables */
+                result += encode_size_struct2(acmp, funp->creator, dflags);
+                result += encode_size_struct2(acmp, funp->fe->module, dflags);
+                result += 2 * (1+4);	/* Index, Uniq */
 		if (funp->num_free > 1) {
 		    WSTACK_PUSH2(s, (UWord) (funp->env + 1),
 				    (UWord) TERM_ARRAY_OP(funp->num_free-1));
@@ -4411,7 +4391,7 @@ decoded_size(byte *ep, byte* endp, int internal_tags, B2TContext* ctx)
         }
     }
     else
-        reds = 0; /* not used but compiler warns anyway */
+        ERTS_UNDEF(reds, 0);
 
     heap_size = 0;
     terms = 1;
@@ -4721,3 +4701,177 @@ error:
 #undef SKIP2
 #undef CHKSIZE
 }
+
+
+struct transcode_context {
+    enum {
+        TRANSCODE_DEC_MSG_SIZE,
+        TRANSCODE_DEC_MSG,
+        TRANSCODE_ENC_CTL,
+        TRANSCODE_ENC_MSG
+    }state;
+    Eterm ctl_term;
+    Eterm* ctl_heap;
+    ErtsHeapFactory ctl_factory;
+    Eterm* msg_heap;
+    B2TContext b2t;
+    TTBEncodeContext ttb;
+#ifdef DEBUG
+    ErtsDistOutputBuf* dbg_ob;
+#endif
+};
+
+void transcode_free_ctx(DistEntry* dep)
+{
+    struct transcode_context* ctx = dep->transcode_ctx;
+
+    erts_factory_close(&ctx->ctl_factory);
+    erts_free(ERTS_ALC_T_DIST_TRANSCODE, ctx->ctl_heap);
+
+    if (ctx->msg_heap) {
+        erts_factory_close(&ctx->b2t.u.dc.factory);
+        erts_free(ERTS_ALC_T_DIST_TRANSCODE, ctx->msg_heap);
+    }
+    erts_free(ERTS_ALC_T_DIST_TRANSCODE, ctx);
+    dep->transcode_ctx = NULL;
+}
+
+Sint transcode_dist_obuf(ErtsDistOutputBuf* ob,
+                         DistEntry* dep,
+                         Uint32 dflags,
+                         Sint reds)
+{
+    Sint hsz;
+    byte* decp;
+    const int have_msg = !!ob->msg_start;
+    int i;
+    struct transcode_context* ctx = dep->transcode_ctx;
+
+    if (!ctx) { /* first call for 'ob' */
+
+        if (~dflags & (DFLAG_BIT_BINARIES | DFLAG_EXPORT_PTR_TAG)) {
+            /*
+             * Receiver does not support bitstrings and/or export funs.
+             * We need to transcode control and message terms to use tuple fallbacks.
+             */
+            ctx = erts_alloc(ERTS_ALC_T_DIST_TRANSCODE, sizeof(struct transcode_context));
+            dep->transcode_ctx = ctx;
+        #ifdef DEBUG
+            ctx->dbg_ob = ob;
+        #endif
+
+            hsz = decoded_size(ob->extp, ob->ext_endp, 0, NULL);
+            ctx->ctl_heap = erts_alloc(ERTS_ALC_T_DIST_TRANSCODE, hsz*sizeof(Eterm));
+            erts_factory_tmp_init(&ctx->ctl_factory, ctx->ctl_heap, hsz, ERTS_ALC_T_DIST_TRANSCODE);
+            ctx->msg_heap = NULL;
+
+            decp = dec_term(NULL, &ctx->ctl_factory, ob->extp, &ctx->ctl_term, NULL);
+            if (have_msg) {
+                ASSERT(decp == ob->msg_start); (void)decp;
+                ctx->b2t.u.sc.ep = NULL;
+                ctx->b2t.state = B2TSize;
+                ctx->b2t.aligned_alloc = NULL;
+                ctx->b2t.b2ts.exttmp = 0;
+                ctx->state = TRANSCODE_DEC_MSG_SIZE;
+            }
+            else {
+                ASSERT(decp == ob->ext_endp);
+                ctx->state = TRANSCODE_ENC_CTL;
+            }
+        }
+        else {
+            /*
+             * No need for full transcoding, but primitive receiver (erl_/jinterface)
+             * expects VERSION_MAGIC before both control and message terms.
+             */
+            if (ob->msg_start) {
+                Sint ctl_bytes = ob->msg_start - ob->extp;
+                ASSERT(ob->extp < ob->msg_start && ob->msg_start < ob->ext_endp);
+                /* Move control term back 1 byte to make room */
+                sys_memmove(ob->extp-1, ob->extp, ctl_bytes);
+                *--(ob->msg_start) = VERSION_MAGIC;
+                --(ob->extp);
+                reds -= ctl_bytes / (B2T_BYTES_PER_REDUCTION * B2T_MEMCPY_FACTOR);
+            }
+            *--(ob->extp) = VERSION_MAGIC;
+            goto done;
+        }
+    }
+    else {
+        ASSERT(ctx->dbg_ob == ob);
+    }
+    ctx->b2t.reds = reds * B2T_BYTES_PER_REDUCTION;
+
+    switch (ctx->state) {
+    case TRANSCODE_DEC_MSG_SIZE:
+        hsz = decoded_size(ob->msg_start, ob->ext_endp, 0, &ctx->b2t);
+        if (ctx->b2t.state == B2TSize) {
+            return -1;
+        }
+        ASSERT(ctx->b2t.state == B2TDecodeInit);
+        ctx->msg_heap = erts_alloc(ERTS_ALC_T_DIST_TRANSCODE, hsz*sizeof(Eterm));
+        ctx->b2t.u.dc.ep = ob->msg_start;
+        ctx->b2t.u.dc.res = (Eterm) NULL;
+        ctx->b2t.u.dc.next = &ctx->b2t.u.dc.res;
+        erts_factory_tmp_init(&ctx->b2t.u.dc.factory,
+                              ctx->msg_heap, hsz, ERTS_ALC_T_DIST_TRANSCODE);
+        ctx->b2t.u.dc.flat_maps.wstart = NULL;
+        ctx->b2t.u.dc.hamt_array.pstart = NULL;
+        ctx->b2t.state = B2TDecode;
+
+        ctx->state = TRANSCODE_DEC_MSG;
+    case TRANSCODE_DEC_MSG:
+        if (ctx->b2t.reds <= 0)
+            ctx->b2t.reds = 1;
+        decp = dec_term(NULL, NULL, NULL, NULL, &ctx->b2t);
+        if (ctx->b2t.state < B2TDone) {
+            return -1;
+        }
+        ASSERT(ctx->b2t.state == B2TDone);
+        ASSERT(decp && decp <= ob->ext_endp);
+        reds = ctx->b2t.reds / B2T_BYTES_PER_REDUCTION;
+        b2t_destroy_context(&ctx->b2t);
+
+        ctx->state = TRANSCODE_ENC_CTL;
+    case TRANSCODE_ENC_CTL:
+        if (!(dflags & DFLAG_DIST_HDR_ATOM_CACHE)) {
+            ASSERT(!(dflags & DFLAG_NO_MAGIC));
+            ob->extp -= 2; /* VERSION_MAGIC x 2 */
+        }
+        ob->ext_endp = ob->extp;
+        i = erts_encode_dist_ext(ctx->ctl_term, &ob->ext_endp, dflags,
+                                 NULL, NULL, NULL);
+        ASSERT(i == 0); (void)i;
+        ASSERT(ob->ext_endp <= ob->alloc_endp);
+
+        if (!have_msg) {
+            break;
+        }
+        ob->msg_start = ob->ext_endp;
+        ctx->ttb.wstack.wstart = NULL;
+        ctx->ttb.flags = dflags;
+        ctx->ttb.level = 0;
+
+        ctx->state = TRANSCODE_ENC_MSG;
+    case TRANSCODE_ENC_MSG:
+        reds *= TERM_TO_BINARY_LOOP_FACTOR;
+        if (erts_encode_dist_ext(ctx->b2t.u.dc.res, &ob->ext_endp, dflags, NULL,
+                                 &ctx->ttb, &reds)) {
+            return -1;
+        }
+        reds /= TERM_TO_BINARY_LOOP_FACTOR;
+
+        ASSERT(ob->ext_endp <= ob->alloc_endp);
+
+    }
+    transcode_free_ctx(dep);
+
+done:
+    if (!(dflags & DFLAG_DIST_HDR_ATOM_CACHE))
+        *--(ob->extp) = PASS_THROUGH;
+
+    if (reds < 0)
+        reds = 0;
+
+    return reds;
+}
diff --git a/erts/emulator/beam/external.h b/erts/emulator/beam/external.h
index 3c61d013da..f9f8abcc27 100644
--- a/erts/emulator/beam/external.h
+++ b/erts/emulator/beam/external.h
@@ -109,35 +109,26 @@ typedef struct {
 } ErtsAtomTranslationTable;
 
 /*
- * These flags are tagged onto the high bits of a connection ID and stored in
- * the ErtsDistExternal structure's flags field.  They are used to indicate
- * various bits of state necessary to decode binaries in a variety of
- * scenarios. The mask ERTS_DIST_EXT_CON_ID_MASK is used later to separate the
- * connection ID from the flags. Be careful to ensure that the mask does not
- * overlap any of the bits used for flags, or ERTS will leak flags bits into
- * connection IDs and leak connection ID bits into the flags.
+ * These flags are stored in the ErtsDistExternal structure's flags field.
+ * They are used to indicate various bits of state necessary to decode binaries
+ * in a variety of scenarios.
  */
-#define ERTS_DIST_EXT_DFLAG_HDR      ((Uint32) 0x80000000)
-#define ERTS_DIST_EXT_ATOM_TRANS_TAB ((Uint32) 0x40000000)
-#define ERTS_DIST_EXT_BTT_SAFE       ((Uint32) 0x20000000)
-#define ERTS_DIST_EXT_CON_ID_MASK    ((Uint32) 0x1fffffff)
+#define ERTS_DIST_EXT_DFLAG_HDR      ((Uint32) 0x1)
+#define ERTS_DIST_EXT_ATOM_TRANS_TAB ((Uint32) 0x2)
+#define ERTS_DIST_EXT_BTT_SAFE       ((Uint32) 0x4)
+
+#define ERTS_DIST_CON_ID_MASK ((Uint32) 0x00ffffff) /* also in net_kernel.erl */
 
-#define ERTS_DIST_EXT_CON_ID(DIST_EXTP) \
-  ((DIST_EXTP)->flags & ERTS_DIST_EXT_CON_ID_MASK)
 typedef struct {
     DistEntry *dep;
     byte *extp;
     byte *ext_endp;
     Sint heap_size;
+    Uint32 connection_id;
     Uint32 flags;
     ErtsAtomTranslationTable attab;
 } ErtsDistExternal;
 
-typedef struct {
-    int have_header;
-    int cache_entries;
-} ErtsDistHeaderPeek;
-
 #define ERTS_DIST_EXT_SIZE(EDEP) \
   (sizeof(ErtsDistExternal) \
    - (((EDEP)->flags & ERTS_DIST_EXT_ATOM_TRANS_TAB) \
@@ -163,7 +154,7 @@ void erts_finalize_atom_cache_map(ErtsAtomCacheMap *, Uint32);
 
 Uint erts_encode_ext_dist_header_size(ErtsAtomCacheMap *);
 byte *erts_encode_ext_dist_header_setup(byte *, ErtsAtomCacheMap *);
-byte *erts_encode_ext_dist_header_finalize(byte *, ErtsAtomCache *, Uint32);
+Sint erts_encode_ext_dist_header_finalize(ErtsDistOutputBuf*, DistEntry *, Uint32 dflags, Sint reds);
 struct erts_dsig_send_context;
 int erts_encode_dist_ext_size(Eterm, Uint32, ErtsAtomCacheMap*, Uint* szp);
 int erts_encode_dist_ext_size_int(Eterm term, struct erts_dsig_send_context* ctx, Uint* szp);
@@ -177,9 +168,6 @@ Uint erts_encode_ext_size_ets(Eterm);
 void erts_encode_ext(Eterm, byte **);
 byte* erts_encode_ext_ets(Eterm, byte *, struct erl_off_heap_header** ext_off_heap);
 
-#ifdef ERTS_WANT_EXTERNAL_TAGS
-ERTS_GLB_INLINE void erts_peek_dist_header(ErtsDistHeaderPeek *, byte *, Uint);
-#endif
 ERTS_GLB_INLINE void erts_free_dist_ext_copy(ErtsDistExternal *);
 ERTS_GLB_INLINE void *erts_dist_ext_trailer(ErtsDistExternal *);
 ErtsDistExternal *erts_make_dist_ext_copy(ErtsDistExternal *, Uint);
@@ -207,23 +195,9 @@ void erts_binary2term_abort(ErtsBinary2TermState *);
 Eterm erts_binary2term_create(ErtsBinary2TermState *, ErtsHeapFactory*);
 int erts_debug_max_atom_out_cache_index(void);
 int erts_debug_atom_to_out_cache_index(Eterm);
-
+void transcode_free_ctx(DistEntry* dep);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
-#ifdef ERTS_WANT_EXTERNAL_TAGS
-ERTS_GLB_INLINE void
-erts_peek_dist_header(ErtsDistHeaderPeek *dhpp, byte *ext, Uint sz)
-{
-    if (ext[0] == VERSION_MAGIC
-	|| ext[1] != DIST_HEADER
-	|| sz < (1+1+1))
-	dhpp->have_header = 0;
-    else {
-	dhpp->have_header = 1;
-	dhpp->cache_entries = (int) get_int8(&ext[2]);
-    }
-}
-#endif
 
 ERTS_GLB_INLINE void
 erts_free_dist_ext_copy(ErtsDistExternal *edep)
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index 85013af3ad..9933c8dda4 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -3829,11 +3829,12 @@ static void sweep_one_link(ErtsLink *lnk, void *vpsc)
 	    ErtsDistLinkData dld;
 	    ErtsDSigData dsd;
 	    int code;
-	    code = erts_dsig_prepare(&dsd, dep, NULL, ERTS_DSP_NO_LOCK, 0);
+	    code = erts_dsig_prepare(&dsd, dep, NULL, 0, ERTS_DSP_NO_LOCK, 0, 0);
 	    switch (code) {
 	    case ERTS_DSIG_PREP_NOT_ALIVE:
 	    case ERTS_DSIG_PREP_NOT_CONNECTED:
 		break;
+	    case ERTS_DSIG_PREP_PENDING:
 	    case ERTS_DSIG_PREP_CONNECTED:
 		erts_remove_dist_link(&dld, port_id, lnk->pid, dep);
 		erts_destroy_dist_link(&dld);
diff --git a/erts/emulator/test/binary_SUITE.erl b/erts/emulator/test/binary_SUITE.erl
index cbc2d8fae5..b59c22f125 100644
--- a/erts/emulator/test/binary_SUITE.erl
+++ b/erts/emulator/test/binary_SUITE.erl
@@ -58,7 +58,9 @@
 	 otp_5484/1,otp_5933/1,
 	 ordering/1,unaligned_order/1,gc_test/1,
 	 bit_sized_binary_sizes/1,
-	 otp_6817/1,deep/1,obsolete_funs/1,robustness/1,otp_8117/1,
+	 otp_6817/1,deep/1,
+         term2bin_tuple_fallbacks/1,
+         robustness/1,otp_8117/1,
 	 otp_8180/1, trapping/1, large/1,
 	 error_after_yield/1, cmp_old_impl/1]).
 
@@ -79,7 +81,8 @@ all() ->
      bad_term_to_binary, more_bad_terms, otp_5484, otp_5933,
      ordering, unaligned_order, gc_test,
      bit_sized_binary_sizes, otp_6817, otp_8117, deep,
-     obsolete_funs, robustness, otp_8180, trapping, large,
+     term2bin_tuple_fallbacks,
+     robustness, otp_8180, trapping, large,
      error_after_yield, cmp_old_impl].
 
 groups() -> 
@@ -1300,40 +1303,28 @@ deep_roundtrip(T) ->
     B = term_to_binary(T),
     T = binary_to_term(B).
 
-obsolete_funs(Config) when is_list(Config) ->
+term2bin_tuple_fallbacks(Config) when is_list(Config) ->
     erts_debug:set_internal_state(available_internal_state, true),
 
-    X = id({1,2,3}),
-    Y = id([a,b,c,d]),
-    Z = id({x,y,z}),
-    obsolete_fun(fun() -> ok end),
-    obsolete_fun(fun() -> X end),
-    obsolete_fun(fun(A) -> {A,X} end),
-    obsolete_fun(fun() -> {X,Y} end),
-    obsolete_fun(fun() -> {X,Y,Z} end),
-
-    obsolete_fun(fun ?MODULE:all/1),
+    term2bin_tf(fun ?MODULE:all/1),
+    term2bin_tf(<<1:1>>),
+    term2bin_tf(<<90,80:7>>),
 
     erts_debug:set_internal_state(available_internal_state, false),
     ok.
 
-obsolete_fun(Fun) ->
-    Tuple = case erlang:fun_info(Fun, type) of
-		{type,external} ->
-		    {module,M} = erlang:fun_info(Fun, module),
-		    {name,F} = erlang:fun_info(Fun, name),
-		    {M,F};
-		{type,local} ->
-		    {module,M} = erlang:fun_info(Fun, module),
-		    {index,I} = erlang:fun_info(Fun, index),
-		    {uniq,U} = erlang:fun_info(Fun, uniq),
-		    {env,E} = erlang:fun_info(Fun, env),
-		    {'fun',M,I,U,list_to_tuple(E)}
-	    end,
-    Tuple = no_fun_roundtrip(Fun).
-
-no_fun_roundtrip(Term) ->
-    binary_to_term_stress(erts_debug:get_internal_state({term_to_binary_no_funs,Term})).
+term2bin_tf(Term) ->
+    Tuple = case Term of
+                Fun when is_function(Fun) ->
+                    {type, external} = erlang:fun_info(Fun, type),
+                    {module,M} = erlang:fun_info(Fun, module),
+                    {name,F} = erlang:fun_info(Fun, name),
+                    {M,F};
+                BS when bit_size(BS) rem 8 =/= 0 ->
+                    Bits = bit_size(BS) rem 8,
+                    {<<BS/bitstring, 0:(8-Bits)>>, Bits}
+            end,
+    Tuple = binary_to_term_stress(erts_debug:get_internal_state({term_to_binary_tuple_fallbacks,Term})).
 
 %% Test non-standard encodings never generated by term_to_binary/1
 %% but recognized by binary_to_term/1.
diff --git a/erts/emulator/test/distribution_SUITE.erl b/erts/emulator/test/distribution_SUITE.erl
index e2914cbc92..f1831b7c45 100644
--- a/erts/emulator/test/distribution_SUITE.erl
+++ b/erts/emulator/test/distribution_SUITE.erl
@@ -35,13 +35,18 @@
 
 -include_lib("common_test/include/ct.hrl").
 
+%-define(Line, erlang:display({line,?LINE}),).
+-define(Line,).
+
 -export([all/0, suite/0, groups/0,
          ping/1, bulk_send_small/1,
+         group_leader/1,
+         optimistic_dflags/1,
          bulk_send_big/1, bulk_send_bigbig/1,
          local_send_small/1, local_send_big/1,
          local_send_legal/1, link_to_busy/1, exit_to_busy/1,
          lost_exit/1, link_to_dead/1, link_to_dead_new_node/1,
-         applied_monitor_node/1, ref_port_roundtrip/1, nil_roundtrip/1,
+         ref_port_roundtrip/1, nil_roundtrip/1,
          trap_bif_1/1, trap_bif_2/1, trap_bif_3/1,
          stop_dist/1,
          dist_auto_connect_never/1, dist_auto_connect_once/1,
@@ -61,6 +66,8 @@
 
 %% Internal exports.
 -export([sender/3, receiver2/2, dummy_waiter/0, dead_process/0,
+         group_leader_1/1,
+         optimistic_dflags_echo/0, optimistic_dflags_sender/1,
          roundtrip/1, bounce/1, do_dist_auto_connect/1, inet_rpc_server/1,
          dist_parallel_sender/3, dist_parallel_receiver/0,
          dist_evil_parallel_receiver/0]).
@@ -74,8 +81,10 @@ suite() ->
 
 all() ->
     [ping, {group, bulk_send}, {group, local_send},
+     group_leader,
+     optimistic_dflags,
      link_to_busy, exit_to_busy, lost_exit, link_to_dead,
-     link_to_dead_new_node, applied_monitor_node,
+     link_to_dead_new_node,
      ref_port_roundtrip, nil_roundtrip, stop_dist,
      {group, trap_bif}, {group, dist_auto_connect},
      dist_parallel_send, atom_roundtrip, unicode_atom_roundtrip,
@@ -124,6 +133,96 @@ ping(Config) when is_list(Config) ->
 
     ok.
 
+%% Test erlang:group_leader(_, ExternalPid), i.e. DOP_GROUP_LEADER
+group_leader(Config) when is_list(Config) ->
+    ?Line Sock = start_relay_node(group_leader_1, []),
+    ?Line Sock2 = start_relay_node(group_leader_2, []),
+    try
+        ?Line Node2 = inet_rpc_nodename(Sock2),
+        ?Line {ok, ok} = do_inet_rpc(Sock, ?MODULE, group_leader_1, [Node2])
+    after
+        ?Line stop_relay_node(Sock),
+        ?Line stop_relay_node(Sock2)
+    end,
+    ok.
+
+group_leader_1(Node2) ->
+    ?Line ExtPid = spawn(Node2, fun F() ->
+                                        receive {From, group_leader} ->
+                                                From ! {self(), group_leader, group_leader()}
+                                        end,
+                                        F()
+                                end),
+    ?Line GL1 = self(),
+    ?Line group_leader(GL1, ExtPid),
+    ?Line ExtPid ! {self(), group_leader},
+    ?Line {ExtPid, group_leader, GL1} = receive_one(),
+
+    %% Kill connection and repeat test when group_leader/2 triggers auto-connect
+    ?Line net_kernel:monitor_nodes(true),
+    ?Line net_kernel:disconnect(Node2),
+    ?Line {nodedown, Node2} = receive_one(),
+    ?Line GL2 = spawn(fun() -> dummy end),
+    ?Line group_leader(GL2, ExtPid),
+    ?Line {nodeup, Node2} = receive_one(),
+    ?Line ExtPid ! {self(), group_leader},
+    ?Line {ExtPid, group_leader, GL2} = receive_one(),
+    ok.
+
+%% Test optimistic distribution flags toward pending connections (DFLAG_DIST_HOPEFULLY)
+optimistic_dflags(Config) when is_list(Config) ->
+    ?Line Sender = start_relay_node(optimistic_dflags_sender, []),
+    ?Line Echo = start_relay_node(optimistic_dflags_echo, []),
+    try
+        ?Line {ok, ok} = do_inet_rpc(Echo, ?MODULE, optimistic_dflags_echo, []),
+
+        ?Line EchoNode = inet_rpc_nodename(Echo),
+        ?Line {ok, ok} = do_inet_rpc(Sender, ?MODULE, optimistic_dflags_sender, [EchoNode])
+    after
+        ?Line stop_relay_node(Sender),
+        ?Line stop_relay_node(Echo)
+    end,
+    ok.
+
+optimistic_dflags_echo() ->
+    P = spawn(fun F() ->
+                      receive {From, Term} ->
+                              From ! {self(), Term}
+                      end,
+                      F()
+              end),
+    register(optimistic_dflags_echo, P),
+    optimistic_dflags_echo ! {self(), hello},
+    {P, hello} = receive_one(),
+    ok.
+
+optimistic_dflags_sender(EchoNode) ->
+    ?Line net_kernel:monitor_nodes(true),
+
+    optimistic_dflags_do(EchoNode, <<1:1>>),
+    optimistic_dflags_do(EchoNode, fun lists:map/2),
+    ok.
+
+optimistic_dflags_do(EchoNode, Term) ->
+    ?Line {optimistic_dflags_echo, EchoNode} ! {self(), Term},
+    ?Line {nodeup, EchoNode} = receive_one(),
+    ?Line {EchoPid, Term} = receive_one(),
+    %% repeat with pid destination
+    ?Line net_kernel:disconnect(EchoNode),
+    ?Line {nodedown, EchoNode} = receive_one(),
+    ?Line EchoPid ! {self(), Term},
+    ?Line {nodeup, EchoNode} = receive_one(),
+    ?Line {EchoPid, Term} = receive_one(),
+
+    ?Line net_kernel:disconnect(EchoNode),
+    ?Line {nodedown, EchoNode} = receive_one(),
+    ok.
+
+
+receive_one() ->
+    receive M -> M after 1000 -> timeout end.
+
+
 bulk_send_small(Config) when is_list(Config) ->
     bulk_send(64, 32).
 
@@ -639,26 +738,6 @@ link_to_dead_new_node(Config) when is_list(Config) ->
     end,
     ok.
 
-%% Test that monitor_node/2 works when applied.
-applied_monitor_node(Config) when is_list(Config) ->
-    NonExisting = list_to_atom("__non_existing__@" ++ hostname()),
-
-    %% Tail-recursive call to apply (since the node is non-existing,
-    %% there will be a trap).
-
-    true = tail_apply(erlang, monitor_node, [NonExisting, true]),
-    [{nodedown, NonExisting}] = test_server:messages_get(),
-
-    %% Ordinary call (with trap).
-
-    true = apply(erlang, monitor_node, [NonExisting, true]),
-    [{nodedown, NonExisting}] = test_server:messages_get(),
-
-    ok.
-
-tail_apply(M, F, A) ->
-    apply(M, F, A).
-
 %% Test that sending a port or reference to another node and back again
 %% doesn't correct them in any way.
 ref_port_roundtrip(Config) when is_list(Config) ->
@@ -1158,8 +1237,6 @@ contended_atom_cache_entry_test(Config, Type) ->
     spawn_link(
       SNode,
       fun () ->
-              erts_debug:set_internal_state(available_internal_state,
-                                            true),
               Master = self(),
               CIX = get_cix(),
               TestAtoms = case Type of
@@ -1244,7 +1321,7 @@ get_cix(CIX) when is_integer(CIX), CIX < 0 ->
 get_cix(CIX) when is_integer(CIX) ->
     get_cix(CIX,
             unwanted_cixs(),
-            erts_debug:get_internal_state(max_atom_out_cache_index)).
+            get_internal_state(max_atom_out_cache_index)).
 
 get_cix(CIX, Unwanted, MaxCIX) when CIX > MaxCIX ->
     get_cix(0, Unwanted, MaxCIX);
@@ -1256,8 +1333,8 @@ get_cix(CIX, Unwanted, MaxCIX) ->
 
 unwanted_cixs() ->
     lists:map(fun (Node) ->
-                      erts_debug:get_internal_state({atom_out_cache_index,
-                                                     Node})
+                      get_internal_state({atom_out_cache_index,
+                                          Node})
               end,
               nodes()).
 
@@ -1266,7 +1343,7 @@ get_conflicting_atoms(_CIX, 0) ->
     [];
 get_conflicting_atoms(CIX, N) ->
     Atom = list_to_atom("atom" ++ integer_to_list(erlang:unique_integer([positive]))),
-    case erts_debug:get_internal_state({atom_out_cache_index, Atom}) of
+    case get_internal_state({atom_out_cache_index, Atom}) of
         CIX ->
             [Atom|get_conflicting_atoms(CIX, N-1)];
         _ ->
@@ -1277,7 +1354,7 @@ get_conflicting_unicode_atoms(_CIX, 0) ->
     [];
 get_conflicting_unicode_atoms(CIX, N) ->
     Atom = string_to_atom([16#1f608] ++ "atom" ++ integer_to_list(erlang:unique_integer([positive]))),
-    case erts_debug:get_internal_state({atom_out_cache_index, Atom}) of
+    case get_internal_state({atom_out_cache_index, Atom}) of
         CIX ->
             [Atom|get_conflicting_unicode_atoms(CIX, N-1)];
         _ ->
@@ -1885,11 +1962,26 @@ send_bad_dhdr(BadNode, ToNode) when is_atom(BadNode), is_atom(ToNode) ->
     receive Done -> ok end.
 
 dctrl(Node) when is_atom(Node) ->
-    case catch erts_debug:get_internal_state(available_internal_state) of
-        true -> true;
-        _ -> erts_debug:set_internal_state(available_internal_state, true)
-    end,
-    erts_debug:get_internal_state({dist_ctrl, Node}).
+    get_internal_state({dist_ctrl, Node}).
+
+get_internal_state(Op) ->
+    try erts_debug:get_internal_state(Op) of
+        R -> R
+    catch
+        error:undef ->
+            erts_debug:set_internal_state(available_internal_state, true),
+            erts_debug:get_internal_state(Op)
+    end.
+
+set_internal_state(Op, Val) ->
+    try erts_debug:set_internal_state(Op, Val) of
+        R -> R
+    catch
+        error:undef ->
+            erts_debug:set_internal_state(available_internal_state, true),
+            erts_debug:set_internal_state(Op, Val)
+    end.
+
 
 dmsg_hdr() ->
     [131, % Version Magic
@@ -2032,11 +2124,9 @@ freeze_node(Node, MS) ->
     Freezer = self(),
     spawn_link(Node,
                fun () ->
-                       erts_debug:set_internal_state(available_internal_state,
-                                                     true),
                        dctrl_dop_send(Freezer, DoingIt),
                        receive after Own -> ok end,
-                       erts_debug:set_internal_state(block, MS+Own)
+                       set_internal_state(block, MS+Own)
                end),
     receive DoingIt -> ok end,
     receive after Own -> ok end.
@@ -2240,8 +2330,7 @@ forever(Fun) ->
     forever(Fun).
 
 abort(Why) ->
-    erts_debug:set_internal_state(available_internal_state, true),
-    erts_debug:set_internal_state(abort, Why).
+    set_internal_state(abort, Why).
 
 
 start_busy_dist_port_tracer() ->
diff --git a/erts/emulator/test/erl_link_SUITE.erl b/erts/emulator/test/erl_link_SUITE.erl
index d8c5b663e3..a66ca7a57d 100644
--- a/erts/emulator/test/erl_link_SUITE.erl
+++ b/erts/emulator/test/erl_link_SUITE.erl
@@ -200,13 +200,16 @@ monitor_nodes(Config) when is_list(Config) ->
     monitor_node(A, true),
     check_monitor_node(self(), A, 1),
     check_monitor_node(self(), B, 3),
+    ok = receive {nodedown, C} -> ok after 1000 -> timeout end,
+    %%OTP-21: monitor_node(_,false) does not trigger auto-connect anymore
+    %%        and therefore no nodedown if it fails.
+    %%ok = receive {nodedown, C} -> ok after 1000 -> timeout end,
+    ok = receive {nodedown, C} -> ok after 1000 -> timeout end,
+    ok = receive {nodedown, D} -> ok after 1000 -> timeout end,
+    ok = receive {nodedown, D} -> ok after 1000 -> timeout end,
     check_monitor_node(self(), C, 0),
     check_monitor_node(self(), D, 0),
-    receive {nodedown, C} -> ok end,
-    receive {nodedown, C} -> ok end,
-    receive {nodedown, C} -> ok end,
-    receive {nodedown, D} -> ok end,
-    receive {nodedown, D} -> ok end,
+
     stop_node(A),
     receive {nodedown, A} -> ok end,
     check_monitor_node(self(), A, 0),
diff --git a/erts/emulator/test/node_container_SUITE.erl b/erts/emulator/test/node_container_SUITE.erl
index be90f929df..7df001fec5 100644
--- a/erts/emulator/test/node_container_SUITE.erl
+++ b/erts/emulator/test/node_container_SUITE.erl
@@ -966,6 +966,8 @@ check_refc(ThisNodeName,ThisCreation,Table,EntryList) when is_list(EntryList) ->
                         {case Referrer of
                              {system,delayed_delete_timer} ->
                                  true;
+                             {system,thread_progress_delete_timer} ->
+                                 true;
                              _ ->
                                  DDT
                          end,
diff --git a/erts/preloaded/ebin/erlang.beam b/erts/preloaded/ebin/erlang.beam
index 181a718287..01ed412562 100644
--- a/erts/preloaded/ebin/erlang.beam
+++ b/erts/preloaded/ebin/erlang.beam
diff --git a/erts/preloaded/ebin/erts_internal.beam b/erts/preloaded/ebin/erts_internal.beam
index 5416826f19..cb8e6b6d69 100644
--- a/erts/preloaded/ebin/erts_internal.beam
+++ b/erts/preloaded/ebin/erts_internal.beam
diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index 80bceae506..2be053575b 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -31,8 +31,7 @@
 -export([localtime_to_universaltime/1]).
 -export([suspend_process/1]).
 -export([min/2, max/2]).
--export([dlink/1, dunlink/1, dsend/2, dsend/3, dgroup_leader/2,
-	 dexit/2, dmonitor_node/3, dmonitor_p/2]).
+-export([dmonitor_node/3, dmonitor_p/2]).
 -export([delay_trap/2]).
 -export([set_cookie/2, get_cookie/0]).
 -export([nodes/0]).
@@ -124,7 +123,7 @@
 -export([crc32/2, crc32_combine/3, date/0, decode_packet/3]).
 -export([delete_element/2]).
 -export([delete_module/1, demonitor/1, demonitor/2, display/1]).
--export([display_nl/0, display_string/1, dist_exit/3, erase/0, erase/1]).
+-export([display_nl/0, display_string/1, erase/0, erase/1]).
 -export([error/1, error/2, exit/1, exit/2, external_size/1]).
 -export([external_size/2, finish_after_on_load/2, finish_loading/1, float/1]).
 -export([float_to_binary/1, float_to_binary/2,
@@ -704,14 +703,6 @@ display_nl() ->
 display_string(_P1) ->
     erlang:nif_error(undefined).
 
-%% dist_exit/3
--spec erlang:dist_exit(P1, P2, P3) -> true when
-      P1 :: pid(),
-      P2 :: kill | noconnection | normal,
-      P3 :: pid() | port().
-dist_exit(_P1, _P2, _P3) ->
-    erlang:nif_error(undefined).
-
 %% dt_append_vm_tag_data/1
 -spec erlang:dt_append_vm_tag_data(IoData) -> IoDataRet when
       IoData :: iodata(),
@@ -3267,34 +3258,11 @@ dist_ctrl_get_data_notification(_DHandle) ->
 dist_get_stat(_DHandle) ->
     erlang:nif_error(undefined).
 
-%%
-%% If the emulator wants to perform a distributed command and
-%% a connection is not established to the actual node the following 
-%% functions are called in order to set up the connection and then
-%% reactivate the command.
-%%
-
--spec erlang:dlink(pid() | port()) -> 'true'.
-dlink(Pid) ->
-    case net_kernel:connect(erlang:node(Pid)) of
-	true -> erlang:link(Pid);
-	false -> erlang:dist_exit(erlang:self(), noconnection, Pid), true
-    end.
-
-%% Can this ever happen?
--spec erlang:dunlink(identifier()) -> 'true'.
-dunlink(Pid) ->
-    case net_kernel:connect(erlang:node(Pid)) of
-	true -> erlang:unlink(Pid);
-	false -> true
-    end.
-
-dmonitor_node(Node, Flag, []) ->
-    case net_kernel:connect(Node) of
-	true -> erlang:monitor_node(Node, Flag, []);
-	false -> erlang:self() ! {nodedown, Node}, true
-    end;
 
+dmonitor_node(Node, _Flag, []) ->
+    %% Only called when auto-connect attempt failed early in VM
+    erlang:self() ! {nodedown, Node},
+    true;
 dmonitor_node(Node, Flag, Opts) ->
     case lists:member(allow_passive_connect, Opts) of
 	true ->
@@ -3306,71 +3274,12 @@ dmonitor_node(Node, Flag, Opts) ->
 	    dmonitor_node(Node,Flag,[])
     end.
 
-dgroup_leader(Leader, Pid) ->
-    case net_kernel:connect(erlang:node(Pid)) of
-	true -> erlang:group_leader(Leader, Pid);
-	false -> true  %% bad arg ?
-    end.
-
-dexit(Pid, Reason) -> 
-    case net_kernel:connect(erlang:node(Pid)) of
-	true -> erlang:exit(Pid, Reason);
-	false -> true
-    end.
-
-dsend(Pid, Msg) when erlang:is_pid(Pid) ->
-    case net_kernel:connect(erlang:node(Pid)) of
-	true -> erlang:send(Pid, Msg);
-	false -> Msg
-    end;
-dsend(Port, Msg) when erlang:is_port(Port) ->
-    case net_kernel:connect(erlang:node(Port)) of
-	true -> erlang:send(Port, Msg);
-	false -> Msg
-    end;
-dsend({Name, Node}, Msg) ->
-    case net_kernel:connect(Node) of
-	true -> erlang:send({Name,Node}, Msg);
-	false -> Msg;
-	ignored -> Msg				% Not distributed.
-    end.
-
-dsend(Pid, Msg, Opts) when erlang:is_pid(Pid) ->
-    case net_kernel:connect(erlang:node(Pid)) of
-	true -> erlang:send(Pid, Msg, Opts);
-	false -> ok
-    end;
-dsend(Port, Msg, Opts) when erlang:is_port(Port) ->
-    case net_kernel:connect(erlang:node(Port)) of
-	true -> erlang:send(Port, Msg, Opts);
-	false -> ok
-    end;
-dsend({Name, Node}, Msg, Opts) ->
-    case net_kernel:connect(Node) of
-	true -> erlang:send({Name,Node}, Msg, Opts);
-	false -> ok;
-	ignored -> ok				% Not distributed.
-    end.
-
 -spec erlang:dmonitor_p('process', pid() | {atom(),atom()}) -> reference().
 dmonitor_p(process, ProcSpec) ->
-    %% ProcSpec = pid() | {atom(),atom()}
-    %% ProcSpec CANNOT be an atom because a locally registered process
-    %% is never handled here.
-    Node = case ProcSpec of
-	       {S,N} when erlang:is_atom(S),
-                          erlang:is_atom(N),
-                          N =/= erlang:node() -> N;
-	       _ when erlang:is_pid(ProcSpec) -> erlang:node(ProcSpec)
-	   end,
-    case net_kernel:connect(Node) of
-	true ->
-	    erlang:monitor(process, ProcSpec);
-	false ->
-	    Ref = erlang:make_ref(),
-	    erlang:self() ! {'DOWN', Ref, process, ProcSpec, noconnection},
-	    Ref
-    end.
+    %% Only called when auto-connect attempt failed early in VM
+    Ref = erlang:make_ref(),
+    erlang:self() ! {'DOWN', Ref, process, ProcSpec, noconnection},
+    Ref.
 
 %%
 %% Trap function used when modified timing has been enabled.
diff --git a/erts/preloaded/src/erts_internal.erl b/erts/preloaded/src/erts_internal.erl
index bb1824ecd4..1f5c88c4b9 100644
--- a/erts/preloaded/src/erts_internal.erl
+++ b/erts/preloaded/src/erts_internal.erl
@@ -63,6 +63,9 @@
 
 -export([dist_ctrl_put_data/2]).
 
+-export([new_connection/1]).
+-export([abort_connection/2]).
+
 %% Auto import name clash
 -export([check_process_code/1]).
 
@@ -498,3 +501,16 @@ dist_ctrl_put_data(DHandle, IoList) ->
                           | RootST],
 	    erlang:raise(Class, Reason, StackTrace)
     end.
+
+
+-spec erts_internal:new_connection(Node) -> ConnId when
+      Node :: atom(),
+      ConnId :: {integer(), erlang:dist_handle()}.
+new_connection(_Node) ->
+    erlang:nif_error(undefined).
+
+-spec erts_internal:abort_connection(Node, ConnId) -> boolean() when
+      Node :: atom(),
+      ConnId :: {integer(), erlang:dist_handle()}.
+abort_connection(_Node, _ConnId) ->
+    erlang:nif_error(undefined).