/**
  * 定时器,检查某些连接是否已超过最大时间
  * @param $serv
  * @param $interval
  */
 function onTimer($serv, $interval)
 {
     $now = time();
     //echo "timer $interval\n";
     foreach ($this->requests as $request) {
         if ($request->time < $now - $this->request_timeout) {
             $response = new Swoole\Response();
             $response->send_head('Access-Control-Allow-Origin', 'http://127.0.0.1');
             $response->body = json_encode(array('success' => 0, 'text' => 'timeout'));
             $this->response($request, $response);
         }
     }
 }