access channel locks through ast_channel_lock/unlock/trylock and not

through ast_mutex primitives.

To detect all occurrences, I have renamed the lock field in struct ast_channel
so it is clear that it shouldn't be used directly.

There are some uses in res/res_features.c (see details of the diff)
that are error prone as they try and lock two channels without
caring about the order (or without explaining why it is safe).



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89293 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_channelredirect.c

@@ -81,7 +81,7 @@ static int asyncgoto_exec(struct ast_channel *chan, void *data)
 
 	res = ast_parseable_goto(chan2, args.label);
 
-	ast_mutex_unlock(&chan2->lock);
+	ast_channel_unlock(chan2);
 quit:
 
 	return res;

apps/app_senddtmf.c

@@ -102,13 +102,13 @@ static int manager_play_dtmf(struct mansession *s, const struct message *m)
 	}
 	if (!digit) {
 		astman_send_error(s, m, "No digit specified");
-		ast_mutex_unlock(&chan->lock);
+		ast_channel_unlock(chan);
 		return 0;
 	}
 
 	ast_senddigit(chan, *digit, 0);
 
-	ast_mutex_unlock(&chan->lock);
+	ast_channel_unlock(chan);
 	astman_send_ack(s, m, "DTMF successfully queued");
 	
 	return 0;

apps/app_softhangup.c

@@ -104,11 +104,11 @@ static int softhangup_exec(struct ast_channel *chan, void *data)
 			ast_log(LOG_WARNING, "Soft hanging %s up.\n", c->name);
 			ast_softhangup(c, AST_SOFTHANGUP_EXPLICIT);
 			if (!ast_test_flag(&flags, OPTION_ALL)) {
-				ast_mutex_unlock(&c->lock);
+				ast_channel_unlock(c);
 				break;
 			}
 		}
-		ast_mutex_unlock(&c->lock);
+		ast_channel_unlock(c);
 	}
 
 	return 0;

include/asterisk/channel.h

@@ -421,7 +421,7 @@ struct ast_channel {
 	    							directly, use ast_softhangup() */
 	time_t	whentohangup;				/*!< Non-zero, set to actual time when channel is to be hung up */
 	pthread_t blocker;				/*!< If anyone is blocking, this is them */
-	ast_mutex_t lock;				/*!< Lock, can be used to lock a channel for some operations - see ast_channel_lock() */
+	ast_mutex_t lock_dont_use;				/*!< Lock, can be used to lock a channel for some operations - see ast_channel_lock() */
 	const char *blockproc;				/*!< Procedure causing blocking */
 
 	const char *appl;				/*!< Current application */

include/asterisk/lock.h

@@ -1167,13 +1167,13 @@ AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p),
 #ifndef DEBUG_CHANNEL_LOCKS
 /*! \brief Lock a channel. If DEBUG_CHANNEL_LOCKS is defined 
 	in the Makefile, print relevant output for debugging */
-#define ast_channel_lock(x)		ast_mutex_lock(&x->lock)
+#define ast_channel_lock(x)		ast_mutex_lock(&x->lock_dont_use)
 /*! \brief Unlock a channel. If DEBUG_CHANNEL_LOCKS is defined 
 	in the Makefile, print relevant output for debugging */
-#define ast_channel_unlock(x)		ast_mutex_unlock(&x->lock)
+#define ast_channel_unlock(x)		ast_mutex_unlock(&x->lock_dont_use)
 /*! \brief Try locking a channel. If DEBUG_CHANNEL_LOCKS is defined 
 	in the Makefile, print relevant output for debugging */
-#define ast_channel_trylock(x)		ast_mutex_trylock(&x->lock)
+#define ast_channel_trylock(x)		ast_mutex_trylock(&x->lock_dont_use)
 #else
 
 struct ast_channel;

main/channel.c

@@ -778,7 +778,7 @@ struct ast_channel *ast_channel_alloc(int needqueue, int state, const char *cid_
 	headp = &tmp->varshead;
 	AST_LIST_HEAD_INIT_NOLOCK(headp);
 	
-	ast_mutex_init(&tmp->lock);
+	ast_mutex_init(&tmp->lock_dont_use);
 	
 	AST_LIST_HEAD_INIT_NOLOCK(&tmp->datastores);
 	
@@ -1136,7 +1136,7 @@ void ast_channel_free(struct ast_channel *chan)
 	if (chan->pbx)
 		ast_log(LOG_WARNING, "PBX may not have been terminated properly on '%s'\n", chan->name);
 	free_cid(&chan->cid);
-	ast_mutex_destroy(&chan->lock);
+	ast_mutex_destroy(&chan->lock_dont_use);
 	/* Close pipes if appropriate */
 	if ((fd = chan->alertpipe[0]) > -1)
 		close(fd);
@@ -2883,13 +2883,13 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr)
 			if (!chan->tech->get_base_channel || chan == chan->tech->get_base_channel(chan))
 				res = chan->tech->write(chan, f);
 			else {
-				while (chan->tech->get_base_channel && (((base = chan->tech->get_base_channel(chan)) && ast_mutex_trylock(&base->lock)) || base == NULL)) {
-					ast_mutex_unlock(&chan->lock);
+				while (chan->tech->get_base_channel && (((base = chan->tech->get_base_channel(chan)) && ast_channel_trylock(base)) || base == NULL)) {
+					ast_channel_unlock(chan);
 					usleep(1);
-					ast_mutex_lock(&chan->lock);
+					ast_channel_lock(chan);
 				}
 				res = base->tech->write(base, f);
-				ast_mutex_unlock(&base->lock);
+				ast_channel_unlock(base);
 			}
 		} else
 			res = 0;
@@ -3541,7 +3541,7 @@ int ast_do_masquerade(struct ast_channel *original)
 	/* We need the clone's lock, too */
 	ast_channel_lock(clone);
 
-	ast_debug(2, "Got clone lock for masquerade on '%s' at %p\n", clone->name, &clone->lock);
+	ast_debug(2, "Got clone lock for masquerade on '%s' at %p\n", clone->name, &clone->lock_dont_use);
 
 	/* Having remembered the original read/write formats, we turn off any translation on either
 	   one */
@@ -4670,12 +4670,12 @@ int ast_channel_unlock(struct ast_channel *chan)
 		return 0;
 	}
 
-	res = ast_mutex_unlock(&chan->lock);
+	res = ast_mutex_unlock(&chan->lock_dont_use);
 
 	if (option_debug > 2) {
 #ifdef DEBUG_THREADS
 		int count = 0;
-		if ((count = chan->lock.reentrancy))
+		if ((count = chan->lock_dont_use.reentrancy))
 			ast_debug(3, ":::=== Still have %d locks (recursive)\n", count);
 #endif
 		if (!res)
@@ -4700,12 +4700,12 @@ int ast_channel_lock(struct ast_channel *chan)
 
 	ast_debug(4, "====:::: Locking AST channel %s\n", chan->name);
 
-	res = ast_mutex_lock(&chan->lock);
+	res = ast_mutex_lock(&chan->lock_dont_use);
 
 	if (option_debug > 3) {
 #ifdef DEBUG_THREADS
 		int count = 0;
-		if ((count = chan->lock.reentrancy))
+		if ((count = chan->lock_dont_use.reentrancy))
 			ast_debug(4, ":::=== Now have %d locks (recursive)\n", count);
 #endif
 		if (!res)
@@ -4729,12 +4729,12 @@ int ast_channel_trylock(struct ast_channel *chan)
 
 	ast_debug(3, "====:::: Trying to lock AST channel %s\n", chan->name);
 
-	res = ast_mutex_trylock(&chan->lock);
+	res = ast_mutex_trylock(&chan->lock_dont_use);
 
 	if (option_debug > 2) {
 #ifdef DEBUG_THREADS
 		int count = 0;
-		if ((count = chan->lock.reentrancy))
+		if ((count = chan->lock_dont_use.reentrancy))
 			ast_debug(3, ":::=== Now have %d locks (recursive)\n", count);
 #endif
 		if (!res)

main/manager.c

@@ -1759,7 +1759,7 @@ static int action_sendtext(struct mansession *s, const struct message *m)
 	}
 
 	res = ast_sendtext(c, textmsg);
-	ast_mutex_unlock(&c->lock);
+	ast_channel_unlock(c);
 	
 	if (res > 0)
 		astman_send_ack(s, m, "Success");

res/res_features.c

@@ -2449,17 +2449,17 @@ static char mandescr_bridge[] =
 static void do_bridge_masquerade(struct ast_channel *chan, struct ast_channel *tmpchan)
 {
 	ast_moh_stop(chan);
-	ast_mutex_lock(&chan->lock);
+	ast_channel_lock(chan);
 	ast_setstate(tmpchan, chan->_state);
 	tmpchan->readformat = chan->readformat;
 	tmpchan->writeformat = chan->writeformat;
 	ast_channel_masquerade(tmpchan, chan);
-	ast_mutex_lock(&tmpchan->lock);
+	ast_channel_lock(tmpchan);
 	ast_do_masquerade(tmpchan);
 	/* when returning from bridge, the channel will continue at the next priority */
 	ast_explicit_goto(tmpchan, chan->context, chan->exten, chan->priority + 1);
-	ast_mutex_unlock(&tmpchan->lock);
-	ast_mutex_unlock(&chan->lock);
+	ast_channel_unlock(tmpchan);
+	ast_channel_unlock(chan);
 }
 
 /*!
@@ -2490,9 +2490,9 @@ static int action_bridge(struct mansession *s, const struct message *m)
 		chana = ast_get_channel_by_name_prefix_locked(channela, strlen(channela));
 		chanb = ast_get_channel_by_name_prefix_locked(channelb, strlen(channelb));
 		if (chana)
-			ast_mutex_unlock(&chana->lock);
+			ast_channel_unlock(chana);
 		if (chanb)
-			ast_mutex_unlock(&chanb->lock);
+			ast_channel_unlock(chanb);
 
 		/* send errors if any of the channels could not be found/locked */
 		if (!chana) {
@@ -3186,7 +3186,7 @@ static int bridge_exec(struct ast_channel *chan, void *data)
 		ast_module_user_remove(u);
 		return 0;
 	}
-	ast_mutex_unlock(&current_dest_chan->lock);
+	ast_channel_unlock(current_dest_chan);
 
 	/* answer the channel if needed */
 	if (current_dest_chan->_state != AST_STATE_UP)