server.php

#!/usr/bin/env php
<?php

$jobs = new \SplQueue();
$workers = (int) `nproc`;
for ($i = 0; $i < 5 * $workers; ++$i) {
    $jobs->enqueue(rand(100, 500));
}


`rm -f /tmp/server.sock`;
$socket = stream_socket_server('unix:///tmp/server.sock', $errno, $errstr);
if (!$socket) {
    die (sprintf("Socket error: %d %s", $errno, $errstr));
}

while (!$jobs->isEmpty()) {
    if ($conn = stream_socket_accept($socket)) {
        fwrite($conn, $jobs->shift());
        fclose($conn);
    }
}
fclose($socket);

worker.php

#!/usr/bin/env php
<?php

$workersCount = (int) `nproc`;

for ($i = 0; $i < $workersCount - 1; ++$i) {
    $pid = pcntl_fork();
    if (-1 === $pid) {
        die('Fork error');
    }
    if (0 === $pid) {
        break;
    }
}

while ($socket = stream_socket_client('unix:///tmp/server.sock', $errno, $errstr)) {
    if (false === $socket) {
        die(sprintf("Can not create a socket: %d %s", $errno, $errstr));
    }

    $job = '';
    while (!feof($socket)) {
        $job .= fgets($socket, 1024);
    }
    fclose($socket);
    if ('' === $job) {
        continue;
    }

    $file = fopen('/tmp/results.txt', 'a');
    while (!flock($file, LOCK_EX)) {
        sleep(1);
    }

    fwrite($file, sprintf("Pid: %d, Job: %d, Result: %d\n", posix_getpid(), $job, 2 * $job));
    flock($file, LOCK_UN);
    fclose($file);
}