From fa34b1e5ce8e98c7513e074183721fd229eeee02 Mon Sep 17 00:00:00 2001
From: russell <russell@f38db490-d61c-443f-a65b-d21fe96a405b>
Date: Wed, 13 Oct 2010 15:51:39 +0000
Subject: [PATCH] Merged revisions 291394 via svnmerge from
 https://origsvn.digium.com/svn/asterisk/branches/1.8

................
  r291394 | russell | 2010-10-13 10:46:39 -0500 (Wed, 13 Oct 2010) | 20 lines

  Merged revisions 291393 via svnmerge from
  https://origsvn.digium.com/svn/asterisk/branches/1.6.2

  ................
    r291393 | russell | 2010-10-13 10:29:21 -0500 (Wed, 13 Oct 2010) | 13 lines

    Merged revisions 291392 via svnmerge from
    https://origsvn.digium.com/svn/asterisk/branches/1.4

    ........
      r291392 | russell | 2010-10-13 10:23:19 -0500 (Wed, 13 Oct 2010) | 6 lines

      Lock pvt so pvt->owner can't disappear when queueing up a frame.

      This fixes a crash due to a hangup race condition.

      ABE-2601
    ........
  ................
................


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@291395 f38db490-d61c-443f-a65b-d21fe96a405b
---
 channels/chan_sip.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 26f0a3814..542487956 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -3637,9 +3637,21 @@ static int __sip_autodestruct(const void *data)
 	/* Reset schedule ID */
 	p->autokillid = -1;
 
+
+	/*
+	 * Lock both the pvt and the channel safely so that we can queue up a frame.
+	 */
+	sip_pvt_lock(p);
+	while (p->owner && ast_channel_trylock(p->owner)) {
+		sip_pvt_unlock(p);
+		sched_yield();
+		sip_pvt_lock(p);
+	}
+
 	if (p->owner) {
 		ast_log(LOG_WARNING, "Autodestruct on dialog '%s' with owner in place (Method: %s)\n", p->callid, sip_methods[p->method].text);
 		ast_queue_hangup_with_cause(p->owner, AST_CAUSE_PROTOCOL_ERROR);
+		ast_channel_unlock(p->owner);
 	} else if (p->refer && !p->alreadygone) {
 		ast_debug(3, "Finally hanging up channel after transfer: %s\n", p->callid);
 		transmit_request_with_auth(p, SIP_BYE, 0, XMIT_RELIABLE, 1);
@@ -3653,7 +3665,11 @@ static int __sip_autodestruct(const void *data)
 		/* sip_destroy(p); */		/* Go ahead and destroy dialog. All attempts to recover is done */
 		/* sip_destroy also absorbs the reference */
 	}
+
+	sip_pvt_unlock(p);
+
 	dialog_unref(p, "The ref to a dialog passed to this sched callback is going out of scope; unref it.");
+
 	return 0;
 }