[asterisk-commits] mnicholson: branch 1.4 r220907 - /branches/1.4/apps/app_chanspy.c

[SVN commits to the Asterisk project]

Author: mnicholson
Date: Tue Sep 29 15:14:29 2009
New Revision: 220907

URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=220907
Log:
Avoid a deadlock in chanspy, just in case the spyee is masqueraded and chanspy_ds_chan_fixup() is called with the channel locked.


(closes issue #15965)
Reported by: atis
Patches:
      chanspy-deadlock-fix1.diff uploaded by mnicholson (license 96)
Tested by: atis


Modified:
    branches/1.4/apps/app_chanspy.c

Modified: branches/1.4/apps/app_chanspy.c
URL: http://svnview.digium.com/svn/asterisk/branches/1.4/apps/app_chanspy.c?view=diff&rev=220907&r1=220906&r2=220907
==============================================================================
--- branches/1.4/apps/app_chanspy.c (original)
+++ branches/1.4/apps/app_chanspy.c Tue Sep 29 15:14:29 2009
@@ -250,9 +250,10 @@
 	ast_channel_unlock(chan);
 
 	ast_mutex_lock(&spyee_chanspy_ds->lock);
-	if (spyee_chanspy_ds->chan) {
-		spyee = spyee_chanspy_ds->chan;
-		ast_channel_lock(spyee);
+	while ((spyee = spyee_chanspy_ds->chan) && ast_channel_trylock(spyee)) {
+		/* avoid a deadlock here, just in case spyee is masqueraded and
+		 * chanspy_ds_chan_fixup() is called with the channel locked */
+		DEADLOCK_AVOIDANCE(&spyee_chanspy_ds->lock);
 	}
 	ast_mutex_unlock(&spyee_chanspy_ds->lock);