第一课：TCP服务的创建

//创建Server对象，监听 127.0.0.1:9501端口
$serv = new swoole_server("127.0.0.1", 9501); 

$serv->set(array(
    'reactor_num' => 2, //reactor线程数
    'worker_num' => 4,    //worker 进程数
    'backlog' => 128,   //listen backlog
    'max_request' => 2,
    'dispatch_mode' => 1,
));
//监听连接进入事件
/**
 *$fd 客户端连接的唯一标示
 * $reactor_id 线程id
 */
$serv->on('connect', function ($serv, $fd,$reactor_id) {  
    echo "Client: {$reactor_id} - {$fd} Connect.\n";
});

//监听数据接收事件
$serv->on('receive', function ($serv, $fd, $reactor_id, $data) {
    $serv->send($fd, "Server: {$reactor_id} - {$fd} ".$data);
});

//监听连接关闭事件
$serv->on('close', function ($serv, $fd) {
    echo "Client: Close.\n";
});

//启动服务器
$serv->start(); 
// telnet 127.0.0.1 9501