PHP自定义函数设置超时间

/**
 * selfTunTimeout
 * @desc   监控函数超时
 * @author 陈修超
 * @time 2017年9月27日
 * @param $time
 * @param $fun
 * @param $param
 */
public static function selfTunTimeout($time,$fun,$param){
    $fun = __CLASS__."::$fun";
    try{
        pcntl_alarm($time);
        pcntl_signal(SIGALRM, "self::throwExp");
        $res = call_user_func($fun,$param);
        pcntl_alarm(0);
    }catch(Exception $e){
        echo "$fun TIMEOUT".PHP_EOL;
    }
    var_dump($res);exit;
    return $res;
}

/**
 * throwExp
 * @desc  抛出异常
 * @throws Exception
 */
public static function throwExp(){
    throw new Exception;
}