FS-4867 try patch

src/switch_core_io.c

@@ -151,10 +151,7 @@ SWITCH_DECLARE(switch_status_t) switch_core_session_read_frame(switch_core_sessi
 	
 	for(i = 0; i < 2; i++) {
 		if (session->dmachine[i] && !switch_channel_test_flag(session->channel, CF_BROADCAST)) {
-			if (switch_channel_try_dtmf_lock(session->channel) == SWITCH_STATUS_SUCCESS) {
-				switch_ivr_dmachine_ping(session->dmachine[i], NULL);
-				switch_channel_dtmf_unlock(session->channel);
-			}
+			switch_ivr_dmachine_ping(session->dmachine[i], NULL);
 		}
 	}
 	

src/switch_ivr_async.c

@@ -426,7 +426,9 @@ SWITCH_DECLARE(switch_status_t) switch_ivr_dmachine_ping(switch_ivr_dmachine_t *
 		is_timeout++;
 	}
 	
-	switch_mutex_lock(dmachine->mutex);
+	if (switch_mutex_trylock(dmachine->mutex) != SWITCH_STATUS_SUCCESS) {
+		return SWITCH_STATUS_SUCCESS;
+	}
 
 	if (zstr(dmachine->digits) && !is_timeout) {
 		r = SWITCH_STATUS_SUCCESS;