Make check_bridge back off if it cant get all the locks it wants

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@1321 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_local.c b/channels/chan_local.c
index 9b60a02..1cafbeb 100755 (executable)
--- a/channels/chan_local.c
+++ b/channels/chan_local.c
@@ -134,21 +134,27 @@ static void check_bridge(struct local_pvt *p, int isoutbound)
                return;
        if (isoutbound && p->chan && p->chan->bridge && p->owner) {
                /* Masquerade bridged channel into owner */
-               /* Lock other side first */
-               ast_mutex_lock(&p->chan->bridge->lock);
-               ast_mutex_lock(&p->owner->lock);
-               ast_channel_masquerade(p->owner, p->chan->bridge);
-               ast_mutex_unlock(&p->owner->lock);
-               ast_mutex_unlock(&p->chan->bridge->lock);
-               p->alreadymasqed = 1;
+               /* Lock everything we need, one by one, and give up if
+                  we can't get everything.  Remember, we'll get another
+                  chance in just a little bit */
+               if (!ast_mutex_trylock(&p->chan->bridge->lock)) {
+                       if (!ast_mutex_trylock(&p->owner->lock)) {
+                               ast_channel_masquerade(p->owner, p->chan->bridge);
+                               p->alreadymasqed = 1;
+                               ast_mutex_unlock(&p->owner->lock);
+                       }
+                       ast_mutex_unlock(&p->chan->bridge->lock);
+               }
        } else if (!isoutbound && p->owner && p->owner->bridge && p->chan) {
                /* Masquerade bridged channel into chan */
-               ast_mutex_lock(&p->owner->bridge->lock);
-               ast_mutex_lock(&p->chan->lock);
-               ast_channel_masquerade(p->chan, p->owner->bridge);
-               ast_mutex_unlock(&p->chan->lock);
-               ast_mutex_unlock(&p->owner->bridge->lock);
-               p->alreadymasqed = 1;
+               if (!ast_mutex_trylock(&p->owner->bridge->lock)) {
+                       if (!ast_mutex_trylock(&p->chan->lock)) {
+                               ast_channel_masquerade(p->chan, p->owner->bridge);
+                               p->alreadymasqed = 1;
+                               ast_mutex_unlock(&p->chan->lock);
+                       }
+                       ast_mutex_unlock(&p->owner->bridge->lock);
+               }
        }
 }