*/ final class Delayed implements Promise { private Internal\Placeholder $placeholder; /** @var string|null Event loop watcher identifier. */ private ?string $watcher; /** * @param int $time Milliseconds before succeeding the promise. * @param TReturn $value Succeed the promise with this value. */ public function __construct(int $time, mixed $value = null) { $this->placeholder = $placeholder = new Internal\Placeholder; $watcher = &$this->watcher; $this->watcher = Loop::delay($time, static function () use (&$watcher, $value, $placeholder): void { $watcher = null; $placeholder->resolve($value); }); } public function __destruct() { if ($this->watcher !== null) { Loop::cancel($this->watcher); } } /** * References the internal watcher in the event loop, keeping the loop running while this promise is pending. * * @return self */ public function reference(): self { if ($this->watcher !== null) { Loop::reference($this->watcher); } return $this; } /** * Unreferences the internal watcher in the event loop, allowing the loop to stop while this promise is pending if * no other events are pending in the loop. * * @return self */ public function unreference(): self { if ($this->watcher !== null) { Loop::unreference($this->watcher); } return $this; } /** @inheritDoc */ public function onResolve(callable $onResolved): void { $this->placeholder->onResolve($onResolved); } }