Swoole PHP Coroutine

Swoole Coroutine is similar to Coroutine in the other lanaguge or frameworks. Swoole create one coroutine for each reqeust and schedule based on IO status. It is not necessary to use callback in the server side logic.

PHP Coroutine is supported for Swoole version > 2.0 by default.

If you like to disable the coroutine feature, use --disable-coroutine when compiling the Swoole PHP extension.

Why Coroutine?

Please compare the difference between callback version and coroutine version in the example bellow.

How to use coroutine in Swoole

The following client are supported in Swoole Coroutine:

  • TCP/UDP Client:Swoole\Coroutine\Client
  • HTTP/WebSocket Client:Swoole\Coroutine\HTTP\Client
  • HTTP2 Client:Swoole\Coroutine\HTTP2\Client
  • Redis Client:Swoole\Coroutine\Redis
  • MySql Client:Swoole\Coroutine\MySQL
  • PostgreSql Client:Swoole\Coroutine\PostgreSQL

You can also wrap your own client with Swoole TCP or UDP coroutine client.

swoole_server and swoole_http_server create one coroutine for each request, then maintain and schedule the request based on client side IO status within swoole_server and swoole_http_server.

You can use coroutine client within the following callback functions:

  • onRequet
  • onReceive
  • onConnect

Example code of Swoole Coroutine:

$server = new Swoole\Http\Server("", 9502, SWOOLE_BASE);

    'worker_num' => 1,

$server->on('Request', function ($request, $response) {

    $tcpclient = new Swoole\Coroutine\Client(SWOOLE_SOCK_TCP);
    $tcpclient->connect('', 95010.5)
    $tcpclient->send("hello world\n");

    $redis = new Swoole\Coroutine\Redis();
    $redis->connect('', 6379);

    $mysql = new Swoole\Coroutine\MySQL();
        'host' => '',
        'user' => 'user',
        'password' => 'pass',
        'database' => 'test',
    $mysql->query('select sleep(1)');

    $httpclient = new Swoole\Coroutine\Http\Client('', 9599);
    $httpclient->setHeaders(['Host' => "api.mp.qq.com"]);
    $httpclient->set([ 'timeout' => 1]);

    $tcp_res  = $tcpclient->recv();
    $redis_res = $redis->recv();
    $mysql_res = $mysql->recv();
    $http_res  = $httpclient->recv();

    $response->end('Test End');


The following extensions have to be disabled to use Swoole Coroutine:

  • xdebug
  • phptrace
  • aop
  • molten
  • xhprof

Swoole Coroutine Documents: https://www.swoole.co.uk/docs/modules/swoole-coroutine

Swoole Coroutine methods list: https://www.swoole.co.uk/docs/modules/swoole-coroutine/methods