rpc_server.php

<?php

require_once __DIR__ . '/vendor/autoload.php';
use PhpAmqpLib\Connection\AMQPConnection;
use PhpAmqpLib\Message\AMQPMessage;

$connection = new AMQPConnection('localhost', 5672, 'guest', 'guest');
$channel = $connection->channel();

$channel->queue_declare('rpc_queue', false, false, false, false);

function fib($n) {
	if ($n == 0)
		return 0;
	if ($n == 1)
		return 1;
	return fib($n-1) + fib($n-2);
}

echo " [x] Awaiting RPC requests\n";
$callback = function($req) {
	$n = intval($req->body);
	echo " [.] fib(", $n, ")\n";

	$msg = new AMQPMessage(
		(string) fib($n),
		array('correlation_id' => $req->get('correlation_id'))
		);

	$req->delivery_info['channel']->basic_publish(
		$msg, '', $req->get('reply_to'));
	$req->delivery_info['channel']->basic_ack(
		$req->delivery_info['delivery_tag']);
};

$channel->basic_qos(null, 1, null);
$channel->basic_consume('rpc_queue', '', false, false, false, false, $callback);

while(count($channel->callbacks)) {
    $channel->wait();
}

$channel->close();
$connection->close();

?>