Fix crash in chanspy (bug #5332)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6768 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_chanspy.c

@@ -255,8 +255,9 @@ static int spy_generate(struct ast_channel *chan, void *data, int len, int sampl
 	short buf0[1280], buf1[1280], buf[1280];
 		
 	if (csth->spy.status == CHANSPY_DONE) {
+		/* Channel is already gone more than likely */
 		return -1;
-        }
+	}
 
 	ast_mutex_lock(&csth->spy.lock);
 	while((f = csth->spy.queue[0])) {
@@ -326,7 +327,6 @@ static int spy_generate(struct ast_channel *chan, void *data, int len, int sampl
 	frame.datalen = x * 2;
 
 	if (ast_write(chan, &frame)) {
-		csth->spy.status = CHANSPY_DONE;
 		return -1;
 	}
 
@@ -373,24 +373,12 @@ static void stop_spying(struct ast_channel *chan, struct ast_channel_spy *spy)
 	struct ast_channel_spy *cptr=NULL, *prev=NULL;
 	int count = 0;
 
-	while(ast_mutex_trylock(&chan->lock)) {
-		/* if its locked already it's almost surely hanging up and we are too late 
-		   we can safely remove the head pointer if it points at us without needing a lock.
-		   since everybody spying will be in the same boat whomever is pointing at the head
-		   will surely erase it which is all we really need since it's a linked list of
-		   staticly declared structs that belong to each spy.
-		*/
-		if (chan->spiers == spy) {
-			chan->spiers = NULL;
-			return;
-		}
-		count++;
-		if (count > 10) {
-			return;
-		}
-		sched_yield();
-	}
+	/* If our status has changed, then the channel we're spying on is gone....
+	   DON'T TOUCH IT!!!  RUN AWAY!!! */
+	if (spy->status != CHANSPY_RUNNING)
+		return;
 
+	ast_mutex_lock(&chan->lock);
 	for(cptr=chan->spiers; cptr; cptr=cptr->next) {
 		if (cptr == spy) {
 			if (prev) {

channel.c

@@ -939,22 +939,14 @@ void ast_channel_free(struct ast_channel *chan)
 static void ast_spy_detach(struct ast_channel *chan) 
 {
 	struct ast_channel_spy *chanspy;
-	int to=3000;
-	int sleepms = 100;
 
+	/* Marking the spies as done is sufficient.  Chanspy or spy users will get the picture. */
 	for (chanspy = chan->spiers; chanspy; chanspy = chanspy->next) {
 		if (chanspy->status == CHANSPY_RUNNING) {
 			chanspy->status = CHANSPY_DONE;
 		}
 	}
 
-	/* signal all the spys to get lost and allow them time to unhook themselves 
-	   god help us if they don't......
-	*/
-	while (chan->spiers && to >= 0) {
-		ast_safe_sleep(chan, sleepms);
-		to -= sleepms;
-	}
 	chan->spiers = NULL;
 	return;
 }