fix race condition in double loopback bowout

diff --git a/src/mod/endpoints/mod_loopback/mod_loopback.c b/src/mod/endpoints/mod_loopback/mod_loopback.c
index e711622d34424a17b2b2b5328152aab01b5192fc..7c72d7e136ff18cb785d0090ab8c066c4139bcaf 100644 (file)
--- a/src/mod/endpoints/mod_loopback/mod_loopback.c
+++ b/src/mod/endpoints/mod_loopback/mod_loopback.c
@@ -709,10 +709,26 @@ static switch_status_t channel_read_frame(switch_core_session_t *session, switch
        return status;
 }
 
+static void switch_channel_wait_for_state_or_greater(switch_channel_t *channel, switch_channel_t *other_channel, switch_channel_state_t want_state)
+{
+
+       switch_assert(channel);
+       
+       for (;;) {
+               if ((switch_channel_get_state(channel) < CS_HANGUP && 
+                        switch_channel_get_state(channel) == switch_channel_get_running_state(channel) && switch_channel_get_running_state(channel) == want_state) ||
+                       (other_channel && switch_channel_down_nosig(other_channel)) || switch_channel_down(channel)) {
+                       break;
+               }
+               switch_cond_next();
+       }
+}
+
+
 static switch_status_t find_non_loopback_bridge(switch_core_session_t *session, switch_core_session_t **br_session, const char **br_uuid)
 {
        switch_channel_t *channel = switch_core_session_get_channel(session);
-       const char *a_uuid;
+       const char *a_uuid = NULL;
        switch_core_session_t *sp;
 
        *br_session = NULL;
@@ -722,9 +738,17 @@ static switch_status_t find_non_loopback_bridge(switch_core_session_t *session,
 
        while (a_uuid && (sp = switch_core_session_locate(a_uuid))) {
                if (switch_core_session_check_interface(sp, loopback_endpoint_interface)) {
-                       private_t *tech_pvt = switch_core_session_get_private(sp);
+                       private_t *tech_pvt;
+                       switch_channel_t *spchan = switch_core_session_get_channel(sp);
+
+                       switch_channel_wait_for_state_or_greater(spchan, channel, CS_ROUTING);
+                       
+                       tech_pvt = switch_core_session_get_private(sp);
+
+                       if (tech_pvt->other_channel) {
+                               a_uuid = switch_channel_get_partner_uuid(tech_pvt->other_channel);
+                       }
 
-                       a_uuid = switch_channel_get_partner_uuid(tech_pvt->other_channel);
                        switch_core_session_rwunlock(sp);
                        sp = NULL;
                } else {