swoole的定时器怎么应用

$server->tick(1000, function() use ($server, $fd) {        
    $server->send($fd, "hello world");
    });

<?php

$serv = new Swoole\Server("0.0.0.0", 9501);

$serv->set(array(
    &#39;worker_num&#39; => 1,    //worker process num
));

$serv->on(&#39;connect&#39;, function ($serv, $fd){
    echo "客户端 ".$fd."连接成功 \n";
});
$serv->on(&#39;receive&#39;, function ($serv, $fd, $reactor_id, $data) {
    echo "客户端 ".$fd."发来消息：".$data."\n";
    $serv->send($fd, &#39;Swoole已经介绍到您发送的消息: &#39;.$data);
});
$serv->on(&#39;close&#39;, function ($serv, $fd) {
    echo "客户端 {$fd}关闭连接\n";
});

$serv->on(&#39;WorkerStart&#39;, function ($serv, $worker_id){
    $serv->tick(2000, function(){
        echo "执行定时器任务 ".time()." \n";
    });
});

$serv->start();