<?php require_once __DIR__ . '/../bootstrap.php'; $loop = \React\EventLoop\Factory::create(); $scheduler = new \Rx\Scheduler\EventLoopScheduler($loop); $source = Rx\Observable::race([Rx\Observable::timer(500)->map(function () { return 'foo'; }), Rx\Observable::timer(200)->map(function () { return 'bar'; })]); $source->subscribe($stdoutObserver, $scheduler); $loop->run();