From b07eba0c150c2ff04054a6a2f581cad9170347cc Mon Sep 17 00:00:00 2001
From: Mark Michelson <mmichelson@digium.com>
Date: Mon, 10 Nov 2008 21:14:44 +0000
Subject: [PATCH] Merged revisions 155861 via svnmerge from
 https://origsvn.digium.com/svn/asterisk/branches/1.4

........
r155861 | mmichelson | 2008-11-10 15:07:39 -0600 (Mon, 10 Nov 2008) | 14 lines

Channel drivers assume that when their indicate callback
is invoked, that the channel on which the callback was called
is locked. This patch corrects an instance in chan_agent where
a channel's indicate callback is called directly without first
locking the channel.

This was leading to some observed locking issues in chan_local,
but considering that all channel drivers operate under the
same expectations, the generic fix in chan_agent is the right
way to go.

AST-126


........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@155863 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 channels/chan_agent.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/channels/chan_agent.c b/channels/chan_agent.c
index c8f3381c55..6f34e39b7e 100644
--- a/channels/chan_agent.c
+++ b/channels/chan_agent.c
@@ -728,9 +728,15 @@ static int agent_indicate(struct ast_channel *ast, int condition, const void *da
 	struct agent_pvt *p = ast->tech_pvt;
 	int res = -1;
 	ast_mutex_lock(&p->lock);
-	if (p->chan && !ast_check_hangup(p->chan))
-		res = p->chan->tech->indicate ? p->chan->tech->indicate(p->chan, condition, data, datalen) : -1;
-	else
+	if (p->chan && !ast_check_hangup(p->chan)) {
+		while (ast_channel_trylock(p->chan)) {
+			ast_channel_unlock(ast);
+			usleep(1);
+			ast_channel_lock(ast);
+		}
+  		res = p->chan->tech->indicate ? p->chan->tech->indicate(p->chan, condition, data, datalen) : -1;
+		ast_channel_unlock(p->chan);
+	} else
 		res = 0;
 	ast_mutex_unlock(&p->lock);
 	return res;
-- 
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