xyzshop/helper/room/factory_server.php

<?php
/**
 * Created by PhpStorm.
 * User: stanley-king
 * Date: 2017/12/14
 * Time: 上午11:58
 */

namespace room;
use search\srv_base;

class factory_server extends srv_base
{
    private static $stInstance;

    public static function instance()
    {
        if(self::$stInstance == null) {
            self::$stInstance = new factory_server();
        }
        return self::$stInstance;
    }

    protected function __construct()
    {
        parent::__construct();
    }
}