Simple multi-process ReactPHP server with workers control

server.php

<?php
/**
 * Copyright © EcomDev B.V. All rights reserved.
 * See LICENSE.txt for license details.
 */

declare(strict_types=1);

$port = $argv[1];
$serverName = $argv[2];

$data = (object)[
    'port' => $port,
    'server' => $serverName,
    'processed' => 0
];

require 'vendor/autoload.php';

$loop = React\EventLoop\Factory::create();

$server = new React\Http\Server(function (Psr\Http\Message\ServerRequestInterface $request) use ($data) {
    $data->processed++;
    return new React\Http\Response(
        200,
        ['Content-Type' => 'text/plain'],
        sprintf("Hello %s from server %s:%d!\n", $request->getServerParams()['REMOTE_ADDR'], $data->server, posix_getpid())
    );
});

$socket = new React\Socket\Server('tcp://0.0.0.0:' . $port, $loop);

$server->listen($socket);

$fork = function (callable $child) {
    $pid = pcntl_fork();
    if ($pid === -1) {
        throw new \RuntimeException('Cant fork a process');
    } elseif ($pid > 0) {
        return $pid;
    } else {
        posix_setsid();
        $child();
        exit(0);
    }
};

$processes = [];

for ($i = 1; $i < 10; $i ++) {
    $socket->pause();

    $processes[] = $fork(function () use ($socket, $loop, $data) {
        $socket->resume();
        $loop->addSignal(SIGINT, function () use ($data, $loop) {
            fwrite(STDERR, sprintf('%s finished running, Processed %d requests' . PHP_EOL, posix_getpid(), $data->processed));
            $loop->stop();
        });
        $loop->run();
    });
}

$loop->addSignal(SIGINT, function () use ($processes) {
    foreach ($processes as $pid) {
        posix_kill($pid, SIGINT);
        $status = 0;
        pcntl_waitpid($pid, $status);
    }

    $loop->stop();
});

$loop->run();