Changeset 5572 for pjproject

Timestamp:

Mar 29, 2017 12:43:52 AM (7 years ago)

Author:

ming

Message:

Fixed #2001: Deadlock between dialog lock and transaction group lock

File:

• pjproject/trunk/pjsip/src/pjsip/sip_transaction.c (modified) (1 diff)

pjproject/trunk/pjsip/src/pjsip/sip_transaction.c

@@ -1231 +1231 @@
         PJSIP_EVENT_INIT_TSX_STATE(e, tsx, event_src_type, event_src,
                                    prev_state);
+
+        /* For timer event, release lock to avoid deadlock.
+         * This should be safe because:
+         * 1. The tsx state just switches to TERMINATED or DESTROYED.
+         * 2. There should be no other processing taking place. All other
+         *    events, such as the ones handled by tsx_on_state_terminated()
+         *    should be ignored.
+         * 3. tsx_shutdown() hasn't been called.
+         * Refer to ticket #2001 (https://trac.pjsip.org/repos/ticket/2001).
+         */
+        if (event_src_type == PJSIP_EVENT_TIMER &&
+            (pj_timer_entry *)event_src == &tsx->timeout_timer)
+        {
+            pj_grp_lock_release(tsx->grp_lock);
+        }
+
         (*tsx->tsx_user->on_tsx_state)(tsx, &e);
+
+        if (event_src_type == PJSIP_EVENT_TIMER &&
+            (pj_timer_entry *)event_src == &tsx->timeout_timer)
+        {
+            pj_grp_lock_acquire(tsx->grp_lock);
+        }
     }