<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\Console\SignalRegistry;
final class SignalRegistry
{
/**
* @var array<int, array<callable>>
*/
private array $signalHandlers = [];
/**
* @var array<array<int, array<callable>>>
*/
private array $stack = [];
/**
* @var array<int, callable|int|string>
*/
private array $originalHandlers = [];
public function __construct()
{
if (\function_exists('pcntl_async_signals')) {
pcntl_async_signals(true);
}
}
public function register(int $signal, callable $signalHandler): void
{
$previous = pcntl_signal_get_handler($signal);
if (!isset($this->originalHandlers[$signal])) {
$this->originalHandlers[$signal] = $previous;
}
if (!isset($this->signalHandlers[$signal])) {
if (\is_callable($previous) && [$this, 'handle'] !== $previous) {
$this->signalHandlers[$signal][] = $previous;
}
}
$this->signalHandlers[$signal][] = $signalHandler;
pcntl_signal($signal, [$this, 'handle']);
}
public static function isSupported(): bool
{
return \function_exists('pcntl_signal');
}
/**
* @internal
*/
public function handle(int $signal): void
{
$count = \count($this->signalHandlers[$signal]);
foreach ($this->signalHandlers[$signal] as $i => $signalHandler) {
$hasNext = $i !== $count - 1;
$signalHandler($signal, $hasNext);
}
}
/**
* Pushes the current active handlers onto the stack and clears the active list.
*
* This prepares the registry for a new set of handlers within a specific scope.
*
* @internal
*/
public function pushCurrentHandlers(): void
{
$this->stack[] = $this->signalHandlers;
$this->signalHandlers = [];
}
/**
* Restores the previous handlers from the stack, making them active.
*
* This also restores the original OS-level signal handler if no
* more handlers are registered for a signal that was just popped.
*
* @internal
*/
public function popPreviousHandlers(): void
{
$popped = $this->signalHandlers;
$this->signalHandlers = array_pop($this->stack) ?? [];
// Restore OS handler if no more Symfony handlers for this signal
foreach ($popped as $signal => $handlers) {
if (!($this->signalHandlers[$signal] ?? false) && isset($this->originalHandlers[$signal])) {
pcntl_signal($signal, $this->originalHandlers[$signal]);
}
}
}
/**
* @internal
*/
public function scheduleAlarm(int $seconds): void
{
pcntl_alarm($seconds);
}
}