Merged revisions 273830 via svnmerge from

https://origsvn.digium.com/svn/asterisk/trunk

................
  r273830 | tilghman | 2010-07-02 21:36:31 -0500 (Fri, 02 Jul 2010) | 16 lines
  
  Merged revisions 273793 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.4
  
  ........
    r273793 | tilghman | 2010-07-02 16:36:39 -0500 (Fri, 02 Jul 2010) | 9 lines
    
    Have the DEADLOCK_AVOIDANCE macro warn when an unlock fails, to help catch potentially large software bugs.
    
    (closes issue #17407)
     Reported by: pdf
     Patches: 
           20100527__issue17407.diff.txt uploaded by tilghman (license 14)
     
    Review: https://reviewboard.asterisk.org/r/751/
  ........
................


git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.6.2@273831 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 43 insertions, 12 deletions

diff --git a/include/asterisk/lock.h b/include/asterisk/lock.h
index a000eca06..1dfcbf7c9 100644
--- a/include/asterisk/lock.h
+++ b/include/asterisk/lock.h
@@ -59,6 +59,7 @@
 #include "asterisk/time.h"
 #endif
 #include "asterisk/logger.h"
+#include "asterisk/compiler.h"
 
 /* internal macro to profile mutexes. Only computes the delay on
  * non-blocking calls.
@@ -273,12 +274,20 @@ int ast_find_lock_info(void *lock_addr, char *filename, size_t filename_size, in
 		char __filename[80], __func[80], __mutex_name[80]; \
 		int __lineno; \
 		int __res = ast_find_lock_info(&chan->lock_dont_use, __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \
-		ast_channel_unlock(chan); \
+		int __res2 = ast_channel_unlock(chan); \
 		usleep(1); \
 		if (__res < 0) { /* Shouldn't ever happen, but just in case... */ \
-			ast_channel_lock(chan); \
+			if (__res2) { \
+				ast_log(LOG_WARNING, "Could not unlock channel '%s': %s and no lock info found!  I will NOT try to relock.\n", #chan, strerror(__res2)); \
+			} else { \
+				ast_channel_lock(chan); \
+			} \
 		} else { \
-			__ast_pthread_mutex_lock(__filename, __lineno, __func, __mutex_name, &chan->lock_dont_use); \
+			if (__res2) { \
+				ast_log(LOG_WARNING, "Could not unlock channel '%s': %s.  {{{Originally locked at %s line %d: (%s) '%s'}}}  I will NOT try to relock.\n", #chan, strerror(__res2), __filename, __lineno, __func, __mutex_name); \
+			} else { \
+				__ast_pthread_mutex_lock(__filename, __lineno, __func, __mutex_name, &chan->lock_dont_use); \
+			} \
 		} \
 	} while (0)
 
@@ -287,12 +296,20 @@ int ast_find_lock_info(void *lock_addr, char *filename, size_t filename_size, in
 		char __filename[80], __func[80], __mutex_name[80]; \
 		int __lineno; \
 		int __res = ast_find_lock_info(lock, __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \
-		ast_mutex_unlock(lock); \
+		int __res2 = ast_mutex_unlock(lock); \
 		usleep(1); \
 		if (__res < 0) { /* Shouldn't ever happen, but just in case... */ \
-			ast_mutex_lock(lock); \
+			if (__res2 == 0) { \
+				ast_mutex_lock(lock); \
+			} else { \
+				ast_log(LOG_WARNING, "Could not unlock mutex '%s': %s and no lock info found!  I will NOT try to relock.\n", #lock, strerror(__res2)); \
+			} \
 		} else { \
-			__ast_pthread_mutex_lock(__filename, __lineno, __func, __mutex_name, lock); \
+			if (__res2 == 0) { \
+				__ast_pthread_mutex_lock(__filename, __lineno, __func, __mutex_name, lock); \
+			} else { \
+				ast_log(LOG_WARNING, "Could not unlock mutex '%s': %s.  {{{Originally locked at %s line %d: (%s) '%s'}}}  I will NOT try to relock.\n", #lock, strerror(__res2), __filename, __lineno, __func, __mutex_name); \
+			} \
 		} \
 	} while (0)
 
@@ -313,7 +330,7 @@ int ast_find_lock_info(void *lock_addr, char *filename, size_t filename_size, in
 		char __filename[80], __func[80], __mutex_name[80]; \
 		int __lineno; \
 		int __res = ast_find_lock_info(lock, __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \
-		ast_mutex_unlock(lock);
+		int __res2 = ast_mutex_unlock(lock);
 
 /*!
  * \brief Deadlock avoidance lock
@@ -329,9 +346,17 @@ int ast_find_lock_info(void *lock_addr, char *filename, size_t filename_size, in
  */
 #define DLA_LOCK(lock) \
 		if (__res < 0) { /* Shouldn't ever happen, but just in case... */ \
-			ast_mutex_lock(lock); \
+			if (__res2) { \
+				ast_log(LOG_WARNING, "Could not unlock mutex '%s': %s and no lock info found!  I will NOT try to relock.\n", #lock, strerror(__res2)); \
+			} else { \
+				ast_mutex_lock(lock); \
+			} \
 		} else { \
-			__ast_pthread_mutex_lock(__filename, __lineno, __func, __mutex_name, lock); \
+			if (__res2) { \
+				ast_log(LOG_WARNING, "Could not unlock mutex '%s': %s.  {{{Originally locked at %s line %d: (%s) '%s'}}}  I will NOT try to relock.\n", #lock, strerror(__res2), __filename, __lineno, __func, __mutex_name); \
+			} else { \
+				__ast_pthread_mutex_lock(__filename, __lineno, __func, __mutex_name, lock); \
+			} \
 		} \
 	} while (0)
 
@@ -1670,9 +1695,15 @@ static inline int _ast_rwlock_trywrlock(ast_rwlock_t *t, const char *name,
 	ast_channel_lock(chan);
 
 #define	DEADLOCK_AVOIDANCE(lock) \
-	ast_mutex_unlock(lock); \
-	usleep(1); \
-	ast_mutex_lock(lock);
+	do { \
+		int __res; \
+		if (!(__res = ast_mutex_unlock(lock))) { \
+			usleep(1); \
+			ast_mutex_lock(lock); \
+		} else { \
+			ast_log(LOG_WARNING, "Failed to unlock mutex '%s' (%s).  I will NOT try to relock. {{{ THIS IS A BUG. }}}\n", #lock, strerror(__res)); \
+		} \
+	} while (0)
 
 #define DLA_UNLOCK(lock)	ast_mutex_unlock(lock)