From 080acbfd165f7d8e99f9c52aa7405094dce717b6 Mon Sep 17 00:00:00 2001 From: Joshua Colp Date: Mon, 11 Jun 2007 14:33:12 +0000 Subject: [PATCH] Merged revisions 68682 via svnmerge from https://origsvn.digium.com/svn/asterisk/branches/1.2 ........ r68682 | file | 2007-06-11 10:29:58 -0400 (Mon, 11 Jun 2007) | 2 lines Improve deadlock handling of the channel list. (issue #8376 reported by one47) ........ git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@68683 65c4cc65-6c06-0410-ace0-fbb531ad65f3 --- main/channel.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/main/channel.c b/main/channel.c index c1d3681d31..defc4b6876 100644 --- a/main/channel.c +++ b/main/channel.c @@ -1070,21 +1070,31 @@ static struct ast_channel *channel_find_locked(const struct ast_channel *prev, /* exit if chan not found or mutex acquired successfully */ /* this is slightly unsafe, as we _should_ hold the lock to access c->name */ done = c == NULL || ast_channel_trylock(c) == 0; - if (!done) + if (!done) { if (option_debug) ast_log(LOG_DEBUG, "Avoiding %s for channel '%p'\n", msg, c); + if (retries == 9) { + /* We are about to fail due to a deadlock, so report this + * while we still have the list lock. + */ + if (option_debug) + ast_log(LOG_DEBUG, "Failure, could not lock '%p' after %d retries!\n", c, retries); + /* As we have deadlocked, we will skip this channel and + * see if there is another match. + * NOTE: No point doing this for a full-name match, + * as there can be no more matches. + */ + if (!(name && !namelen)) { + prev = c; + retries = -1; + } + } + } AST_LIST_UNLOCK(&channels); if (done) return c; usleep(1); /* give other threads a chance before retrying */ } - /* - * c is surely not null, but we don't have the lock so cannot - * access c->name - */ - if (option_debug) - ast_log(LOG_DEBUG, "Failure, could not lock '%p' after %d retries!\n", - c, retries); return NULL; }