请教一个swoolewebsocket的问题

$serv = new swoole_websocket_server("127.0.0.1", 9502);



$serv->on('Open', function($server, $req) {

    echo "connection open: ".$req->fd;

});



$serv->on('Message', function($server, $frame) {

    echo "message: ".$frame->data;

    $server->push($frame->fd, json_encode(["hello", "world"]));

});



$serv->on('Close', function($server, $fd) {

    echo "connection close: ".$fd;

});



$serv->start();