Distribute work across subprocesses using 0MQ

multiprocess.php

<?php
$num_workers = 5;

$pid = 1;
for($i = 0; $i < $num_workers; $i++) {
	$pid = pcntl_fork();
	if($pid == 0) {
		break;
	}
}

if($pid == 0) {
	work($i);
} else {
	serve($num_workers);
}

function work($id) {
	$context = new ZMQContext();
	$workpipe = new ZMQSocket($context, ZMQ::SOCKET_PULL);
	$workpipe->connect("ipc://work.ipc");
	$poll = new ZMQPoll();
	$poll->add($workpipe, ZMQ::POLL_IN);
	
	$controlpipe = new ZMQSocket($context, ZMQ::SOCKET_SUB);
	$controlpipe->connect("ipc://control.ipc");
	$controlpipe->setSockOpt(ZMQ::SOCKOPT_SUBSCRIBE, "");
	$controlpipe->setSockOpt(ZMQ::SOCKOPT_IDENTITY, "worker" . $id);
	$controlpoll = new ZMQPoll();
	$controlpoll->add($controlpipe, ZMQ::POLL_IN);
	
	$syncpipe = new ZMQSOcket($context, ZMQ::SOCKET_PUSH);
	$syncpipe->connect("ipc://sync.ipc");
	$syncpipe->send($id);
	
	$readable = array();
	$worked = 0;
	while(true) {
		$events = $poll->poll($readable, null, 5000);
		if($events > 0) {
			foreach($readable as $r) {
				$message = $r->recv();
				//echo "Worker $id got message " . $message . "\n";
				usleep(250);
				$worked++;
			}
		} else {
			$events = $controlpoll->poll($readable, null, 100);
			if($events > 0) {
				$message = $readable[0]->recv();
				echo "$id Ending!\n";
				break;
			}
		}
	}
	echo "Worker $id worked $worked times \n";
}

function serve($workers) {
	$context = new ZMQContext();
	$controlpipe = new ZMQSocket($context, ZMQ::SOCKET_PUB);
	$controlpipe->bind("ipc://control.ipc");
	$workpipe = new ZMQSocket($context, ZMQ::SOCKET_PUSH);
	$workpipe->bind("ipc://work.ipc");
	
	// Sync up with workers
	$syncpipe = new ZMQSocket($context, ZMQ::SOCKET_PULL);
	$syncpipe->bind("ipc://sync.ipc");
	$found = 0;
	$poll = new ZMQPoll();
	$poll->add($syncpipe, ZMQ::POLL_IN);
	$readable = array();
	while(true) {
		$found += $poll->poll($readable, null);;
		foreach($readable as $r) {
			$message = $r->recv();
			echo "Hello $message!\n";
		}
		if($found == $workers) {
			echo "All workers checked in\n";
			break;
		}
	}
	
	foreach(range(1, 10000) as $message) {
		//echo "Sending $message\n";
		$workpipe->send($message);
	}
	echo "Sending END\n";
	$controlpipe->send("END");
}