From 441da04c0ba70e7d77304c5394bd83d834aae432 Mon Sep 17 00:00:00 2001
From: Tilghman Lesher <tilghman@meg.abyt.es>
Date: Wed, 25 Jun 2008 01:13:38 +0000
Subject: [PATCH] Merged revisions 124966 via svnmerge from
 https://origsvn.digium.com/svn/asterisk/trunk

................
r124966 | tilghman | 2008-06-24 20:08:37 -0500 (Tue, 24 Jun 2008) | 15 lines

Merged revisions 124965 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
r124965 | tilghman | 2008-06-24 19:46:24 -0500 (Tue, 24 Jun 2008) | 7 lines

Pvt deadlock causes some channels to get stuck in Reserved status.
(closes issue #12621)
 Reported by: fabianoheringer
 Patches:
       20080612__bug12621.diff.txt uploaded by Corydon76 (license 14)
 Tested by: fabianoheringer

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git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.0@124967 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 channels/chan_dahdi.c   |  7 ++++---
 include/asterisk/lock.h | 19 +++++++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index 8192d752e4..86f13b5275 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -5208,10 +5208,11 @@ static struct ast_frame  *dahdi_read(struct ast_channel *ast)
 	int index;
 	void *readbuf;
 	struct ast_frame *f;
-	
 
-	ast_mutex_lock(&p->lock);
-	
+	while (ast_mutex_trylock(&p->lock)) {
+		CHANNEL_DEADLOCK_AVOIDANCE(ast);
+	}
+
 	index = dahdi_get_index(ast, p, 0);
 	
 	/* Hang up if we don't really exist */
diff --git a/include/asterisk/lock.h b/include/asterisk/lock.h
index e7dfb3075d..1a294d400c 100644
--- a/include/asterisk/lock.h
+++ b/include/asterisk/lock.h
@@ -204,6 +204,20 @@ int ast_find_lock_info(void *lock_addr, const char **filename, int *lineno, cons
  * used during deadlock avoidance, to preserve the original location where
  * a lock was originally acquired.
  */
+#define CHANNEL_DEADLOCK_AVOIDANCE(chan) \
+	do { \
+		const char *__filename, *__func, *__mutex_name; \
+		int __lineno; \
+		int __res = ast_find_lock_info(&chan->lock_dont_use, &__filename, &__lineno, &__func, &__mutex_name); \
+		ast_channel_unlock(chan); \
+		usleep(1); \
+		if (__res < 0) { /* Shouldn't ever happen, but just in case... */ \
+			ast_channel_lock(chan); \
+		} else { \
+			__ast_pthread_mutex_lock(__filename, __lineno, __func, __mutex_name, &chan->lock_dont_use); \
+		} \
+	} while (0)
+
 #define DEADLOCK_AVOIDANCE(lock) \
 	do { \
 		const char *__filename, *__func, *__mutex_name; \
@@ -1067,6 +1081,11 @@ static inline int _ast_rwlock_trywrlock(ast_rwlock_t *lock, const char *name,
 
 #else /* !DEBUG_THREADS */
 
+#define	CHANNEL_DEADLOCK_AVOIDANCE(chan) \
+	ast_channel_lock(chan); \
+	usleep(1); \
+	ast_channel_unlock(chan);
+
 #define	DEADLOCK_AVOIDANCE(lock) \
 	ast_mutex_lock(lock); \
 	usleep(1); \