OpenSwoole WebSocket with WaitGroup example

client.html

<script>
  let ws = new WebSocket('ws://127.0.0.1:9502');
  ws.send("test 1");
  setTimeout(() => ws.send("test 2"), 2000);
</script>

server.php

<?php

use Swoole\WebSocket\Server;
use Swoole\Http\Request;
use Swoole\WebSocket\Frame;
use Swoole\Coroutine\WaitGroup;

$server = new Server("0.0.0.0", 9502);

$server->set([
    'worker_num' => 1,
]);

$state = 0;
$wg = new WaitGroup();

$server->on("Start", function(Server $server) {
    echo "Swoole WebSocket Server is started at http://127.0.0.1:9502\n";
});

$server->on('Open', function(Server $server, Swoole\Http\Request $request) {
    echo "connection open: {$request->fd}\n";
});

$server->on('Message', function(Server $server, Frame $frame) use (&$state, &$wg) {
    $currentState = '';
    $data = '';
    
    if ($state === 0) {
        $wg->add();
        echo "waiting..." . PHP_EOL;
        $currentState = $state;
        $data = $frame->data;
        $state = 1;
    } else {
        echo "released..." . PHP_EOL;
        $wg->done();
        $currentState = $state;
        $data = $frame->data;
        $state = 0;
    }

    $wg->wait(10);
    echo "Message for state " . $currentState . ": " . $data . PHP_EOL;
});

$server->on('Close', function(Server $server, int $fd) {
    echo "connection close: {$fd}\n";
});

$server->on('Disconnect', function(Server $server, int $fd) {
    echo "connection disconnect: {$fd}\n";
});

$server->start();

Output:

woole WebSocket Server is started at http://127.0.0.1:9502
connection open: 1
waiting...
released...
Message for state 0: test 1
Message for state 1: test 2

Does it work also to wait/resume between $server->on('Message') and $server->on('Request') ? i.e. an HTTP request starts a wait, and a WebSocket message ends the wait.. possible?

Yeah, based on our discoveries it works, but only works properly when the server has only 1 worker.