<?php
namespace React\EventLoop\Tick;
use SplQueue;
/**
* A tick queue implementation that can hold multiple callback functions
*
* This class should only be used internally, see LoopInterface instead.
*
* @see LoopInterface
* @internal
*/
final class FutureTickQueue
{
private $queue;
public function __construct()
{
$this->queue = new SplQueue();
}
/**
* Add a callback to be invoked on a future tick of the event loop.
*
* Callbacks are guaranteed to be executed in the order they are enqueued.
*
* @param callable $listener The callback to invoke.
*/
public function add($listener)
{
$this->queue->enqueue($listener);
}
/**
* Flush the callback queue.
*/
public function tick()
{
// Only invoke as many callbacks as were on the queue when tick() was called.
$count = $this->queue->count();
while ($count--) {
\call_user_func(
$this->queue->dequeue()
);
}
}
/**
* Check if the next tick queue is empty.
*
* @return boolean
*/
public function isEmpty()
{
return $this->queue->isEmpty();
}
}