code: function onBusinessStart(Worker $worker) {
          self::$name = $this->_name;
          self::$memcached = new \Memcached();
          if (is_callable($this->_on_business_start))
              call_user_func($this->_on_business_start, $worker);
          self::$_status = self::_STATUS_STARTED;
      }
docs: BusinessWorker启动回调
  
  @param Worker $worker