TT#14008 add explicit lws_cancel_service at shutdown

Newer libwebsockets versions seem to use a longer internal timeout, so
an explicit "interrupt" is needed during shutdown to prevent a long wait
time.

Change-Id: I8f28ef658169178e35b40dd44520fbd7c812b590
(cherry picked from commit 9eb7b640c2)

daemon/main.c

@@ -1343,12 +1343,14 @@ int main(int argc, char **argv) {
 	// reap threads as they shut down during run time
 	threads_join_all(false);
 
+	service_notify("STOPPING=1\n");
+
         // free libevent
 #if LIBEVENT_VERSION_NUMBER >= 0x02010100
         libevent_global_shutdown();
 #endif
 
-	service_notify("STOPPING=1\n");
+	websocket_stop();
 
 	if (!is_addr_unspecified(&rtpe_config.redis_ep.address) && initial_rtpe_config.redis_delete_async)
 		redis_async_event_base_action(rtpe_redis_write, EVENT_BASE_LOOPBREAK);

daemon/websocket.c

@@ -1077,3 +1077,8 @@ void websocket_start(void) {
 		return;
 	thread_create_detach_prio(websocket_loop, NULL, rtpe_config.scheduling, rtpe_config.priority, "websocket");
 }
+void websocket_stop(void) {
+	if (!websocket_context)
+		return;
+	lws_cancel_service(websocket_context);
+}

include/websocket.h

@@ -35,6 +35,7 @@ struct websocket_message {
 
 int websocket_init(void);
 void websocket_start(void);
+void websocket_stop(void);
 
 // appends to output buffer without triggering a response
 void websocket_queue_raw(struct websocket_conn *wc, const char *msg, size_t len);