php Pthread 多线程 Worker

<?php
    //PHP 高级编程之多线程    http://www.netkiller.cn/journal/thread.php.html#idp57489856
    //worker 是一个具有持久化上下文的线程对象，通常用来在多个线程中使用。
    //worker 对象start后，会直接运行run()方法，执行完毕之后，线程也不会die掉
    //SQLQuery 是任务类
    class SQLQuery extends Thread
    {
        public $worker;
        public $sql;
        public function __construct($sql)
        {
            $this->sql = $sql;
        }

        public function run()
        {
             $dbh  = $this->worker->getConnection();
            $row = $dbh->prepare($this->sql,array(PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY));
             $row->execute();
            while($member = $row->fetch(PDO::FETCH_ASSOC))
            {
                // print_r($member);
             }
        }
    }
    //worker 执行任务
    class ExampleWorker extends Worker {
            public static $dbh;
            public function __construct($name) {
            }

            /*
            * The run method should just prepare the environment for the work that is coming ...
            */
            public function run(){
                    self::$dbh = new PDO('mysql:dbname=mix;host=192.168.33.11','root','');
            }
            public function getConnection(){
                    return self::$dbh;
            }
    }

    $worker = new ExampleWorker("My Worker Thread");

    for ($i = 0; $i < 5; ++$i) {
        $worker->stack(new SQLQuery('select * from stores limit '.$i));  // 将要执行的任务入栈
    }
    
    echo "{$worker->getStacked()} tasks
"; //获取栈中剩余的任务数量
    $worker->start();          //执行完Worker中的对象后
    $worker->shutdown();     //关闭Worker。  跟队列很像

    /* 多线程检测服务是否正常案例   https://www.cnblogs.com/zz-952/p/9762284.html
    这里会报错 
    Uncaught RuntimeException: the creator of ExampleWorker already started
    没有线程die掉
    while(true)
    {
        sleep(5);
        $worker->start();
        $worker->shutdown();
    }
    */