From a0d427bd1858b0b5518b39f8ab9b25487369f7c0 Mon Sep 17 00:00:00 2001 From: Mark Michelson Date: Mon, 7 Apr 2008 16:13:23 +0000 Subject: [PATCH] Merged revisions 113066 via svnmerge from https://origsvn.digium.com/svn/asterisk/trunk ................ r113066 | mmichelson | 2008-04-07 11:12:30 -0500 (Mon, 07 Apr 2008) | 21 lines Merged revisions 113065 via svnmerge from https://origsvn.digium.com/svn/asterisk/branches/1.4 ........ r113065 | mmichelson | 2008-04-07 11:08:45 -0500 (Mon, 07 Apr 2008) | 13 lines This fix prevents a deadlock that was experienced in chan_local. There was deadlock prevention in place in chan_local, but it would not work in a specific case because the channel was recursively locked. By unlocking the channel prior to calling the generator's generate callback in ast_read_generator_actions(), we prevent the recursive locking, and therefore the deadlock. (closes issue #12307) Reported by: callguy Patches: 12307.patch uploaded by putnopvut (license 60) Tested by: callguy ........ ................ git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.0@113067 65c4cc65-6c06-0410-ace0-fbb531ad65f3 --- main/channel.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/main/channel.c b/main/channel.c index 920ee37dda..478d9bdd87 100644 --- a/main/channel.c +++ b/main/channel.c @@ -2273,7 +2273,17 @@ static void ast_read_generator_actions(struct ast_channel *chan, struct ast_fram } else { samples = f->samples; } + /* This unlock is here based on two assumptions that hold true at this point in the + * code. 1) this function is only called from within __ast_read() and 2) all generators + * call ast_write() in their generate callback. + * + * The reason this is added is so that when ast_write is called, the lock that occurs + * there will not recursively lock the channel. Doing this will cause intended deadlock + * avoidance not to work in deeper functions + */ + ast_channel_unlock(chan); res = chan->generator->generate(chan, tmp, f->datalen, samples); + ast_channel_lock(chan); chan->generatordata = tmp; if (res) { if (option_debug > 1)