Ensure exit signal due to link precede port BIF return

5 files changed, 198 insertions, 48 deletions

diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index cbb25c2cf2..062caadad3 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -3032,7 +3032,10 @@ os_prompt% </pre>
           (see below), being synchronous, and that the port does
 	  <em>not</em> reply with <c>{Port, closed}</c>. Any process may
 	  close a port with <c>port_close/1</c>, not only the port owner
-	  (the connected process).</p>
+	  (the connected process). If the calling process is linked to
+	  port identified by <c><anno>Port</anno></c>, an exit signal due
+	  to that link will be received by the process prior to the return
+	  from <c>port_close/1</c>.</p>
         <p>For comparison: <c><anno>Port</anno> ! {self(), close}</c> fails with
           <c>badarg</c> if <c><anno>Port</anno></c> cannot be sent to (i.e.,
           <c><anno>Port</anno></c> refers neither to a port nor to a process). If
@@ -3041,6 +3044,7 @@ os_prompt% </pre>
           the port replies with <c>{Port, closed}</c> when all buffers
           have been flushed and the port really closes, but if
           the calling process is not the port owner the <em>port owner</em> fails with <c>badsig</c>.</p>
+
         <p>Note that any process can close a port using
           <c><anno>Port</anno> ! {PortOwner, close}</c> just as if it itself was
           the port owner, but the reply always goes to the port owner.</p>
@@ -3050,8 +3054,17 @@ os_prompt% </pre>
 	   implementation has been synchronous. <c>port_close/1</c> is
 	   however still fully synchronous. This due to its error
 	   behavior.</p>
-        <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not an open port or
-          the registered name of an open port.</p>
+        <p>Failure:</p>
+        <taglist>
+          <tag><c>badarg</c></tag>
+          <item>
+	     If <c><anno>Port</anno></c> is not an identifier of an open
+	     port, or the registered name of an open port. If the calling
+	     process was linked to the previously open port identified by
+	     <c><anno>Port</anno></c>, an exit signal due to this link
+	     was received by the process prior to this exception.
+	  </item>
+	</taglist>
       </desc>
     </func>
     <func>
@@ -3086,8 +3099,11 @@ os_prompt% </pre>
         <taglist>
           <tag><c>badarg</c></tag>
           <item>
-	     If <c><anno>Port</anno></c> is not an open port or the registered name
-	     of an open port.
+	     If <c><anno>Port</anno></c> is not an identifier of an open
+	     port, or the registered name of an open port. If the calling
+	     process was linked to the previously open port identified by
+	     <c><anno>Port</anno></c>, an exit signal due to this link
+	     was received by the process prior to this exception.
 	  </item>
           <tag><c>badarg</c></tag>
           <item>
@@ -3130,8 +3146,11 @@ os_prompt% </pre>
         <taglist>
           <tag><c>badarg</c></tag>
           <item>
-	     If <c><anno>Port</anno></c> is not an open port or the registered name
-	     of an open port.
+	     If <c><anno>Port</anno></c> is not an identifier of an open
+	     port, or the registered name of an open port. If the calling
+	     process was linked to the previously open port identified by
+	     <c><anno>Port</anno></c>, an exit signal due to this link
+	     was received by the process prior to this exception.
 	  </item>
           <tag><c>badarg</c></tag>
           <item>
@@ -3198,9 +3217,20 @@ os_prompt% </pre>
 	   implementation has been synchronous. <c>port_connect/2</c> is
 	   however still fully synchronous. This due to its error
 	   behavior.</p>
-        <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not an open port
-          or the registered name of an open port, or if <c>Pid</c> is
-          not an existing local pid.</p>
+        <p>Failures:</p>
+        <taglist>
+          <tag><c>badarg</c></tag>
+          <item>
+	     If <c><anno>Port</anno></c> is not an identifier of an open
+	     port, or the registered name of an open port. If the calling
+	     process was linked to the previously open port identified by
+	     <c><anno>Port</anno></c>, an exit signal due to this link
+	     was received by the process prior to this exception.
+	  </item>
+          <tag><c>badarg</c></tag>
+	  <item>If process identified by <c>Pid</c> is not an existing
+	  local process.</item>
+	</taglist>
       </desc>
     </func>
     <func>
@@ -3236,12 +3266,33 @@ os_prompt% </pre>
           binary term format and sent to the port.</p>
         <p>Returns: a term from the driver. The meaning of the returned
           data also depends on the port driver.</p>
-        <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not an open port or
-          the registered name of an open port, if <c><anno>Operation</anno></c>
-          cannot fit in a 32-bit integer, if the port driver does not
-          support synchronous control operations, or if the port driver
-          so decides for any reason (probably something wrong with
-          <c><anno>Operation</anno></c> or <c><anno>Data</anno></c>).</p>
+        <p>Failures:</p>
+        <taglist>
+          <tag><c>badarg</c></tag>
+          <item>
+	     If <c><anno>Port</anno></c> is not an identifier of an open
+	     port, or the registered name of an open port. If the calling
+	     process was linked to the previously open port identified by
+	     <c><anno>Port</anno></c>, an exit signal due to this link
+	     was received by the process prior to this exception.
+	  </item>
+          <tag><c>badarg</c></tag>
+	  <item>
+	     If <c><anno>Operation</anno></c> does not fit in a
+	     32-bit integer.
+	  </item>
+          <tag><c>badarg</c></tag>
+	  <item>
+	     If the port driver does not support synchronous control
+	     operations.
+	  </item>
+          <tag><c>badarg</c></tag>
+	  <item>
+	     If the port driver so decides for any reason (probably
+	     something wrong with <c><anno>Operation</anno></c>, or
+	     <c><anno>Data</anno></c>).
+	  </item>
+	</taglist>
       </desc>
     </func>
     <func>
@@ -3251,7 +3302,12 @@ os_prompt% </pre>
         <p>Returns a list containing tuples with information about
           the <c><anno>Port</anno></c>, or <c>undefined</c> if the port is not open.
           The order of the tuples is not defined, nor are all the
-          tuples mandatory.</p>
+          tuples mandatory.
+	  If <c>undefined</c> is returned and the calling process
+	  was linked to a previously open port identified by
+	  <c><anno>Port</anno></c>, an exit signal due to this link
+	  was received by the process prior to the return from
+	  <c>port_info/1</c>.</p>
 	<p>Currently the result will containt information about the
 	following <c>Item</c>s: <c>registered_name</c> (if the port has
 	a registered name), <c>id</c>, <c>connected</c>, <c>links</c>,
@@ -3269,7 +3325,11 @@ os_prompt% </pre>
 	<p><c><anno>Pid</anno></c> is the process identifier of the process
 	connected to the port.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3281,7 +3341,11 @@ os_prompt% </pre>
 	<p><c><anno>Index</anno></c> is the internal index of the port. This
 	index may be used to separate ports.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3293,7 +3357,11 @@ os_prompt% </pre>
 	<p><c><anno>Bytes</anno></c> is the total number of bytes
 	read from the port.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3305,7 +3373,11 @@ os_prompt% </pre>
 	<p><c><anno>Pids</anno></c> is a list of the process identifiers
 	of the processes that the port is linked to.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3320,7 +3392,11 @@ os_prompt% </pre>
 	that these results are highly implementation specific and might
 	change in the future.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3334,7 +3410,11 @@ os_prompt% </pre>
 	that the port itself might have allocated memory which is not
 	included in <c><anno>Bytes</anno></c>.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3346,7 +3426,11 @@ os_prompt% </pre>
 	<p><c><anno>Monitors</anno></c> represent processes that this port
 	is monitoring.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3358,7 +3442,11 @@ os_prompt% </pre>
 	<p><c><anno>Name</anno></c> is the command name set by
 	<seealso marker="#open_port/2">open_port/2</seealso>.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3373,7 +3461,11 @@ os_prompt% </pre>
 	Command}, Options)</seealso>. If the port is not the result of spawning
 	an OS process, the value is <c>undefined</c>.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3389,7 +3481,11 @@ os_prompt% </pre>
 	or <c><anno>Port</anno> ! {Owner, {command, Data}</c>.
 	</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3412,7 +3508,11 @@ os_prompt% </pre>
 	in bytes, queued by the port using the ERTS driver queue
 	implementation.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
@@ -3424,7 +3524,11 @@ os_prompt% </pre>
 	<p><c><anno>RegisteredName</anno></c> is the registered name of
 	the port. If the port has no registered name, <c>[]</c> is returned.</p>
 	<p>If the port identified by <c><anno>Port</anno></c> is not open,
-	<c>undefined</c> is returned.</p>
+	<c>undefined</c> is returned. If <c>undefined</c> is returned and
+	the calling process was linked to a previously open port identified
+	by <c><anno>Port</anno></c>, an exit signal due to this link
+	was received by the process prior to the return from
+	<c>port_info/2</c>.</p>
         <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local
 	port identifier, or an atom.</p>
       </desc>
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 755c5e6882..13d31285b2 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -160,7 +160,10 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
 
     if (is_internal_port(BIF_ARG_1)) {
 	int send_link_signal = 0;
-	Port *prt = erts_port_lookup(BIF_ARG_1, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+	Port *prt = erts_port_lookup(BIF_ARG_1,
+				     (erts_port_synchronous_ops
+				      ? ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
+				      : ERTS_PORT_SFLGS_INVALID_LOOKUP));
 	if (!prt) {
 	    goto res_no_proc;
 	}
@@ -1363,11 +1366,22 @@ BIF_RETTYPE exit_2(BIF_ALIST_2)
       */
 
      if (is_internal_port(BIF_ARG_1)) {
-	 Port *prt = erts_port_lookup(BIF_ARG_1, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+	 Eterm ref, *refp;
+	 Uint32 invalid_flags;
+	 Port *prt;
+
+	 if (erts_port_synchronous_ops) {
+	     refp = &ref;
+	     invalid_flags = ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP;
+	 }
+	 else {
+	     refp = NULL;
+	     invalid_flags = ERTS_PORT_SFLGS_INVALID_LOOKUP;
+	 }
+
+	 prt = erts_port_lookup(BIF_ARG_1, invalid_flags);
 
 	 if (prt) {
-	     Eterm ref;
-	     Eterm *refp = erts_port_synchronous_ops ? &ref : NULL;
 	     ErtsPortOpResult res;
 
 #ifdef DEBUG
@@ -1875,7 +1889,10 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend, Eterm *refp) {
 	if (rp)
 	    goto send_message;
 
-	pt = erts_port_lookup(id, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+	pt = erts_port_lookup(id,
+			      (erts_port_synchronous_ops
+			       ? ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
+			       : ERTS_PORT_SFLGS_INVALID_LOOKUP));
 	if (pt) {
 	    portid = id;
 	    goto port_common;
@@ -1905,7 +1922,10 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend, Eterm *refp) {
 	int ret_val;
 	portid = to;
 
-	pt = erts_port_lookup(portid, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+	pt = erts_port_lookup(portid,
+			      (erts_port_synchronous_ops
+			       ? ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
+			       : ERTS_PORT_SFLGS_INVALID_LOOKUP));
 
       port_common:
 	ret_val = 0;
@@ -1994,7 +2014,10 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend, Eterm *refp) {
 	    rp = erts_proc_lookup_raw(id);
 	    if (rp)
 		goto send_message;
-	    pt = erts_port_lookup(id, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+	    pt = erts_port_lookup(id,
+				  (erts_port_synchronous_ops
+				   ? ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
+				   : ERTS_PORT_SFLGS_INVALID_LOOKUP));
 	    if (pt) {
 		portid = id;
 		goto port_common;
diff --git a/erts/emulator/beam/erl_bif_port.c b/erts/emulator/beam/erl_bif_port.c
index 109c54fd7f..3cd53ef65d 100644
--- a/erts/emulator/beam/erl_bif_port.c
+++ b/erts/emulator/beam/erl_bif_port.c
@@ -84,7 +84,7 @@ BIF_RETTYPE open_port_2(BIF_ALIST_2)
 }
 
 static ERTS_INLINE Port *
-lookup_port(Process *c_p, Eterm id_or_name)
+lookup_port(Process *c_p, Eterm id_or_name, Uint32 invalid_flags)
 {
     /* TODO: Implement nicer lookup in register... */
     Eterm id;
@@ -92,7 +92,19 @@ lookup_port(Process *c_p, Eterm id_or_name)
 	id = erts_whereis_name_to_id(c_p, id_or_name);
     else
 	id = id_or_name;
-    return erts_port_lookup(id, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+    return erts_port_lookup(id, invalid_flags);
+}
+
+static ERTS_INLINE Port *
+sig_lookup_port(Process *c_p, Eterm id_or_name)
+{
+    return lookup_port(c_p, id_or_name, ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
+}
+
+static ERTS_INLINE Port *
+data_lookup_port(Process *c_p, Eterm id_or_name)
+{
+    return lookup_port(c_p, id_or_name, ERTS_PORT_SFLGS_INVALID_LOOKUP);
 }
 
 /*
@@ -125,7 +137,7 @@ BIF_RETTYPE erts_internal_port_command_3(BIF_ALIST_3)
 	    BIF_RET(am_badarg);
     }
 
-    prt = lookup_port(BIF_P, BIF_ARG_1);
+    prt = sig_lookup_port(BIF_P, BIF_ARG_1);
     if (!prt)
 	BIF_RET(am_badarg);
 
@@ -185,7 +197,7 @@ BIF_RETTYPE erts_internal_port_call_3(BIF_ALIST_3)
     unsigned int op;
     erts_aint32_t state;
 
-    prt = lookup_port(BIF_P, BIF_ARG_1);
+    prt = sig_lookup_port(BIF_P, BIF_ARG_1);
     if (!prt)
 	BIF_RET(am_badarg);
 
@@ -235,7 +247,7 @@ BIF_RETTYPE erts_internal_port_control_3(BIF_ALIST_3)
     unsigned int op;
     erts_aint32_t state;
 
-    prt = lookup_port(BIF_P, BIF_ARG_1);
+    prt = sig_lookup_port(BIF_P, BIF_ARG_1);
     if (!prt)
 	BIF_RET(am_badarg);
 
@@ -290,7 +302,7 @@ BIF_RETTYPE erts_internal_port_close_1(BIF_ALIST_1)
     ref = NIL;
 #endif
 
-    prt = lookup_port(BIF_P, BIF_ARG_1);
+    prt = sig_lookup_port(BIF_P, BIF_ARG_1);
     if (!prt)
 	BIF_RET(am_badarg);
 
@@ -320,7 +332,7 @@ BIF_RETTYPE erts_internal_port_connect_2(BIF_ALIST_2)
     Eterm ref;
     Port* prt;
 
-    prt = lookup_port(BIF_P, BIF_ARG_1);
+    prt = sig_lookup_port(BIF_P, BIF_ARG_1);
     if (!prt)
 	BIF_RET(am_badarg);
 
@@ -352,7 +364,7 @@ BIF_RETTYPE erts_internal_port_info_1(BIF_ALIST_1)
     Port* prt;
 
     if (is_internal_port(BIF_ARG_1) || is_atom(BIF_ARG_1)) {
-	prt = lookup_port(BIF_P, BIF_ARG_1);
+	prt = sig_lookup_port(BIF_P, BIF_ARG_1);
 	if (!prt)
 	    BIF_RET(am_undefined);
     }
@@ -391,7 +403,7 @@ BIF_RETTYPE erts_internal_port_info_2(BIF_ALIST_2)
     Port* prt;
 
     if (is_internal_port(BIF_ARG_1) || is_atom(BIF_ARG_1)) {
-	prt = lookup_port(BIF_P, BIF_ARG_1);
+	prt = sig_lookup_port(BIF_P, BIF_ARG_1);
 	if (!prt)
 	    BIF_RET(am_undefined);
     }
@@ -523,7 +535,7 @@ BIF_RETTYPE port_set_data_2(BIF_ALIST_2)
     erts_aint_t data;
     Port* prt;
 
-    prt = lookup_port(BIF_P, BIF_ARG_1);
+    prt = data_lookup_port(BIF_P, BIF_ARG_1);
     if (!prt)
         BIF_ERROR(BIF_P, BADARG);
 
@@ -564,7 +576,7 @@ BIF_RETTYPE port_get_data_1(BIF_ALIST_1)
     erts_aint_t data;
     Port* prt;
 
-    prt = lookup_port(BIF_P, BIF_ARG_1);
+    prt = data_lookup_port(BIF_P, BIF_ARG_1);
     if (!prt)
         BIF_ERROR(BIF_P, BADARG);
 
diff --git a/erts/emulator/beam/erl_port_task.h b/erts/emulator/beam/erl_port_task.h
index e4d964146e..123253a057 100644
--- a/erts/emulator/beam/erl_port_task.h
+++ b/erts/emulator/beam/erl_port_task.h
@@ -77,6 +77,7 @@ extern erts_smp_atomic_t erts_port_task_outstanding_io_tasks;
 #define ERTS_PTS_FLG_HAVE_NS_TASKS		(((erts_aint32_t) 1) <<  8)
 #define ERTS_PTS_FLG_PARALLELISM		(((erts_aint32_t) 1) <<  9)
 #define ERTS_PTS_FLG_FORCE_SCHED		(((erts_aint32_t) 1) << 10)
+#define ERTS_PTS_FLG_EXITING			(((erts_aint32_t) 1) << 11)
 
 #define ERTS_PTS_FLGS_BUSY \
     (ERTS_PTS_FLG_BUSY_PORT | ERTS_PTS_FLG_BUSY_PORT_Q)
@@ -86,7 +87,8 @@ extern erts_smp_atomic_t erts_port_task_outstanding_io_tasks;
      | ERTS_PTS_FLG_HAVE_BUSY_TASKS		\
      | ERTS_PTS_FLG_HAVE_TASKS			\
      | ERTS_PTS_FLG_EXEC			\
-     | ERTS_PTS_FLG_FORCE_SCHED)
+     | ERTS_PTS_FLG_FORCE_SCHED			\
+     | ERTS_PTS_FLG_EXITING)
 
 #define ERTS_PORT_TASK_DEFAULT_BUSY_PORT_Q_HIGH			8192
 #define ERTS_PORT_TASK_DEFAULT_BUSY_PORT_Q_LOW			4096
@@ -135,6 +137,7 @@ ERTS_GLB_INLINE void erts_port_task_fini_sched(ErtsPortTaskSched *ptsp);
 ERTS_GLB_INLINE void erts_port_task_sched_lock(ErtsPortTaskSched *ptsp);
 ERTS_GLB_INLINE void erts_port_task_sched_unlock(ErtsPortTaskSched *ptsp);
 ERTS_GLB_INLINE int erts_port_task_sched_lock_is_locked(ErtsPortTaskSched *ptsp);
+ERTS_GLB_INLINE void erts_port_task_sched_enter_exiting_state(ErtsPortTaskSched *ptsp);
 
 #ifdef ERTS_INCLUDE_SCHEDULER_INTERNALS
 ERTS_GLB_INLINE int erts_port_task_have_outstanding_io_tasks(void);
@@ -225,6 +228,12 @@ erts_port_task_fini_sched(ErtsPortTaskSched *ptsp)
 #endif
 }
 
+ERTS_GLB_INLINE void
+erts_port_task_sched_enter_exiting_state(ErtsPortTaskSched *ptsp)
+{
+    erts_smp_atomic32_read_bor_nob(&ptsp->flags, ERTS_PTS_FLG_EXITING);
+}
+
 #ifdef ERTS_INCLUDE_SCHEDULER_INTERNALS
 
 ERTS_GLB_INLINE int
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index 6911fd8241..9076bbe73c 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -3601,6 +3601,8 @@ erts_deliver_port_exit(Port *p, Eterm from, Eterm reason, int send_closed)
    if (send_closed)
        set_state_flags |= ERTS_PORT_SFLG_SEND_CLOSED;
 
+   erts_port_task_sched_enter_exiting_state(&p->sched);
+   
    state = erts_atomic32_read_bor_mb(&p->state, set_state_flags);
    state |= set_state_flags;