Merged revisions 125740 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

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r125740 | tilghman | 2008-06-27 07:19:39 -0500 (Fri, 27 Jun 2008) | 7 lines

Add proper deadlock avoidance.
(closes issue #12914)
 Reported by: ozan
 Patches: 
       20080625__bug12914.diff.txt uploaded by Corydon76 (license 14)
 Tested by: ozan

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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@125741 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_local.c

@@ -219,13 +219,15 @@ static int local_queue_frame(struct local_pvt *p, int isoutbound, struct ast_fra
 
 	/* Ensure that we have both channels locked */
 	while (other && ast_channel_trylock(other)) {
-		DLA_UNLOCK(&p->lock);
+		ast_mutex_unlock(&p->lock);
 		if (us && us_locked) {
-			CHANNEL_DEADLOCK_AVOIDANCE(us);
+			do {
+				CHANNEL_DEADLOCK_AVOIDANCE(us);
+			} while (ast_mutex_trylock(&p->lock));
 		} else {
 			usleep(1);
+			ast_mutex_lock(&p->lock);
 		}
-		DLA_LOCK(&p->lock);
 		other = isoutbound ? p->owner : p->chan;
 	}
 
@@ -542,7 +544,12 @@ static int local_hangup(struct ast_channel *ast)
 	if (!p)
 		return -1;
 
-	ast_mutex_lock(&p->lock);
+	while (ast_mutex_trylock(&p->lock)) {
+		ast_channel_unlock(ast);
+		usleep(1);
+		ast_channel_lock(ast);
+	}
+
 	if (p->chan && ast_test_flag(ast, AST_FLAG_ANSWERED_ELSEWHERE)) 
 		ast_set_flag(p->chan, AST_FLAG_ANSWERED_ELSEWHERE);
 	isoutbound = IS_OUTBOUND(ast, p);