From: Mark Spencer <markster@digium.com>
Date: Tue, 29 Jun 2004 12:38:04 +0000 (+0000)
Subject: Perform deadlock avoidance on initial entry, too
X-Git-Tag: 1.0.0-rc1~115
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6195ae7453514f69455c05c72b99954b2acb49ef;p=thirdparty%2Fasterisk.git

Perform deadlock avoidance on initial entry, too


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@3343 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/channel.c b/channel.c
index 510e0c0d12..4447c27559 100755
--- a/channel.c
+++ b/channel.c
@@ -451,14 +451,28 @@ void ast_channel_undefer_dtmf(struct ast_channel *chan)
 struct ast_channel *ast_channel_walk_locked(struct ast_channel *prev)
 {
 	/* Returns next channel (locked) */
-	struct ast_channel *l, *ret=NULL;
+	struct ast_channel *l, *ret;
 	int retries = 0;	
 retry:
+	ret=NULL;
 	ast_mutex_lock(&chlock);
 	l = channels;
 	if (!prev) {
-		if (l)
-			ast_mutex_lock(&l->lock);
+		if (l) {
+			if (ast_mutex_trylock(&l->lock)) {
+				if (retries < 10)
+					ast_log(LOG_DEBUG, "Avoiding initial deadlock for '%s'\n", ret->name);
+				else
+					ast_log(LOG_WARNING, "Avoided initial deadlock for '%s', %d retries!\n", ret->name, retries);
+				ast_mutex_unlock(&chlock);
+				if (retries < 10) {
+					usleep(1);
+					retries++;
+					goto retry;
+				} else
+					return NULL;
+			}
+		}
 		ast_mutex_unlock(&chlock);
 		return l;
 	}