Patch for deadlock from ordering issue between channel/queue locks in app_queue

(set_queue_variables).

(closes issue #18031)
Reported by: rain

Review: https://reviewboard.asterisk.org/r/1018/

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@295670 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/apps/app_queue.c b/apps/app_queue.c
index e6ce9495b585320d8b64c2d53b9ee2b7760657eb..28efe67be759ce7b3987af341efece5f785fdc2e 100644 (file)
--- a/apps/app_queue.c
+++ b/apps/app_queue.c
@@ -1134,6 +1134,8 @@ static void set_queue_variables(struct call_queue *q, struct ast_channel *chan)
        char interfacevar[256]="";
        float sl = 0;
 
+       ao2_lock(q);
+
        if (q->setqueuevar) {
                sl = 0;
                if (q->callscompleted > 0) 
@@ -1142,8 +1144,12 @@ static void set_queue_variables(struct call_queue *q, struct ast_channel *chan)
                snprintf(interfacevar, sizeof(interfacevar),
                        "QUEUENAME=%s,QUEUEMAX=%d,QUEUESTRATEGY=%s,QUEUECALLS=%d,QUEUEHOLDTIME=%d,QUEUETALKTIME=%d,QUEUECOMPLETED=%d,QUEUEABANDONED=%d,QUEUESRVLEVEL=%d,QUEUESRVLEVELPERF=%2.1f",
                        q->name, q->maxlen, int2strat(q->strategy), q->count, q->holdtime, q->talktime, q->callscompleted, q->callsabandoned,  q->servicelevel, sl);
+
+               ao2_unlock(q);
        
                pbx_builtin_setvar_multiple(chan, interfacevar); 
+       } else {
+               ao2_unlock(q);
        }
 }
 
@@ -3173,8 +3179,8 @@ static int say_periodic_announcement(struct queue_ent *qe, int ringing)
 /*! \brief Record that a caller gave up on waiting in queue */
 static void record_abandoned(struct queue_ent *qe)
 {
-       ao2_lock(qe->parent);
        set_queue_variables(qe->parent, qe->chan);
+       ao2_lock(qe->parent);
        manager_event(EVENT_FLAG_AGENT, "QueueCallerAbandon",
                "Queue: %s\r\n"
                "Uniqueid: %s\r\n"
@@ -4096,9 +4102,7 @@ static void end_bridge_callback(void *data)
        struct ast_channel *chan = qeb->chan;
 
        if (ao2_ref(qeb, -1) == 1) {
-               ao2_lock(q);
                set_queue_variables(q, chan);
-               ao2_unlock(q);
                /* This unrefs the reference we made in try_calling when we allocated qeb */
                queue_t_unref(q, "Expire bridge_config reference");
        }
@@ -4568,10 +4572,11 @@ static int try_calling(struct queue_ent *qe, const char *options, char *announce
                        pbx_builtin_setvar_multiple(peer, interfacevar);
                }
        
+               ao2_unlock(qe->parent);
+
                /* try to set queue variables if configured to do so*/
                set_queue_variables(qe->parent, qe->chan);
                set_queue_variables(qe->parent, peer);
-               ao2_unlock(qe->parent);
                
                ast_channel_lock(qe->chan);
                if ((monitorfilename = pbx_builtin_getvar_helper(qe->chan, "MONITOR_FILENAME"))) {