PHP async queue (Process (or not))

Queue.php

<?php

class Queue
{
    private $size;
    private $onJobStart;
    private $isJobRunning;
    private $onJobFinish;

    private $queued;
    private $running;

    public function __construct(callable $onJobStart, callable $isJobRunning, callable $onJobFinish, int $size = 5)
    {
        $this->onJobStart = $onJobStart;
        $this->isJobRunning = $isJobRunning;
        $this->onJobFinish = $onJobFinish;
        $this->size = $size;
        $this->queued = new \SplObjectStorage();
        $this->running = new \SplObjectStorage();
    }

    public function add($job, $data)
    {
        $this->queued->attach($job, $data);
    }

    public function run()
    {
        loop:

        if (!$this->queued->count() && !$this->running->count()) {
            return;
        }

        $this->sortQueue();

        foreach ($this->running as $job) {
            $data = $this->running[$job];
            if (!($this->isJobRunning)($job, $this, $data)) {
                $this->running->detach($job);
                ($this->onJobFinish)($job, $this, $data);
            }
        }

        usleep(10000);

        goto loop;
    }

    private function sortQueue()
    {
        while ($this->running->count() < $this->size && $this->queued->count()) {
            $this->queued->rewind();
            $job = $this->queued->current();
            $data = $this->queued[$job];
            $this->queued->detach($job);
            $this->running->attach($job, $data);
            ($this->onJobStart)($job, $this, $data);
        }
    }
}