From e98fb1920ad053d2db4594c5d33cdfcfcdc6d771 Mon Sep 17 00:00:00 2001
From: Rickard Green <rickard@erlang.org>
Date: Mon, 6 Jul 2015 20:25:28 +0200
Subject: Teach non-smp VM how to deal with trace port crash

---
 erts/emulator/beam/beam_emu.c | 44 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

(limited to 'erts/emulator/beam/beam_emu.c')

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index 8bfb7d2ad2..a4e9fe1cba 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -2082,6 +2082,22 @@ void process_main(void)
 	 OpCase(wait_f):
 
 	 wait2: {
+#ifndef ERTS_SMP
+	     if (ERTS_PROC_IS_EXITING(c_p)) {
+		 /*
+		  * I non smp case:
+		  *
+		  * Currently executing process might be sent an exit
+		  * signal if it is traced by a port that it also is
+		  * linked to, and the port terminates during the
+		  * trace. In this case we do *not* want to clear
+		  * the active flag, which will make the process hang
+		  * in limbo forever.
+		  */
+		 SWAPOUT;
+		 goto do_schedule;
+	     }
+#endif
 	     c_p->i = (BeamInstr *) Arg(0); /* L1 */
 	     SWAPOUT;
 	     c_p->arity = 0;
@@ -6110,6 +6126,23 @@ erts_hibernate(Process* c_p, Eterm module, Eterm function, Eterm args, Eterm* re
     int arity;
     Eterm tmp;
 
+#ifndef ERTS_SMP
+    if (ERTS_PROC_IS_EXITING(c_p)) {
+	/*
+	 * I non smp case:
+	 *
+	 * Currently executing process might be sent an exit
+	 * signal if it is traced by a port that it also is
+	 * linked to, and the port terminates during the
+	 * trace. In this case we do *not* want to clear
+	 * the active flag, which will make the process hang
+	 * in limbo forever. Get out of here and terminate
+	 * the process...
+	 */
+	return -1;
+    }
+#endif
+
     if (is_not_atom(module) || is_not_atom(function)) {
 	/*
 	 * No need to test args here -- done below.
@@ -6186,7 +6219,16 @@ erts_hibernate(Process* c_p, Eterm module, Eterm function, Eterm args, Eterm* re
 	ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 	PROCESS_MAIN_CHK_LOCKS(c_p);
 	erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MSGQ|ERTS_PROC_LOCK_STATUS);
-#ifdef ERTS_SMP
+#ifndef ERTS_SMP
+	if (ERTS_PROC_IS_EXITING(c_p)) {
+	    /*
+	     * See comment in the begining of the function...
+	     *
+	     * This second test is needed since gc might be traced.
+	     */
+	    return -1;
+	}
+#else /* ERTS_SMP */
 	ERTS_SMP_MSGQ_MV_INQ2PRIVQ(c_p);
 	if (!c_p->msg.len)
 #endif
-- 
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