<?php

/*
* This file is part of the Monolog package.
*
* (c) Jordi Boggiano <j.boggiano@seld.be>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/

namespace Monolog;

use Psr\Log\LoggerInterface;
use Psr\Log\LogLevel;
use ReflectionExtension;

/**
* Monolog POSIX signal handler
*
* @author Robert Gust-Bardon <robert@gust-bardon.org>
*/
class SignalHandler
{
private $logger;

private $previousSignalHandler = array();
private $signalLevelMap = array();
private $signalRestartSyscalls = array();

public function __construct(LoggerInterface $logger)
{
$this->logger = $logger;
}

public function registerSignalHandler($signo, $level = LogLevel::CRITICAL, $callPrevious = true, $restartSyscalls = true, $async = true)
{
if (!extension_loaded('pcntl') || !function_exists('pcntl_signal')) {
return $this;
}

if ($callPrevious) {
if (function_exists('pcntl_signal_get_handler')) {
$handler = pcntl_signal_get_handler($signo);
if ($handler === false) {
return $this;
}
$this->previousSignalHandler[$signo] = $handler;
} else {
$this->previousSignalHandler[$signo] = true;
}
} else {
unset($this->previousSignalHandler[$signo]);
}
$this->signalLevelMap[$signo] = $level;
$this->signalRestartSyscalls[$signo] = $restartSyscalls;

if (function_exists('pcntl_async_signals') && $async !== null) {
pcntl_async_signals($async);
}

pcntl_signal($signo, array($this, 'handleSignal'), $restartSyscalls);

return $this;
}

public function handleSignal($signo, array $siginfo = null)
{
static $signals = array();

if (!$signals && extension_loaded('pcntl')) {
$pcntl = new ReflectionExtension('pcntl');
$constants = $pcntl->getConstants();
if (!$constants) {
// HHVM 3.24.2 returns an empty array.
$constants = get_defined_constants(true);
$constants = $constants['Core'];
}
foreach ($constants as $name => $value) {
if (substr($name, 0, 3) === 'SIG' && $name[3] !== '_' && is_int($value)) {
$signals[$value] = $name;
}
}
unset($constants);
}

$level = isset($this->signalLevelMap[$signo]) ? $this->signalLevelMap[$signo] : LogLevel::CRITICAL;
$signal = isset($signals[$signo]) ? $signals[$signo] : $signo;
$context = isset($siginfo) ? $siginfo : array();
$this->logger->log($level, sprintf('Program received signal %s', $signal), $context);

if (!isset($this->previousSignalHandler[$signo])) {
return;
}

if ($this->previousSignalHandler[$signo] === true || $this->previousSignalHandler[$signo] === SIG_DFL) {
if (extension_loaded('pcntl') && function_exists('pcntl_signal') && function_exists('pcntl_sigprocmask') && function_exists('pcntl_signal_dispatch')
&& extension_loaded('posix') && function_exists('posix_getpid') && function_exists('posix_kill')) {
$restartSyscalls = isset($this->signalRestartSyscalls[$signo]) ? $this->signalRestartSyscalls[$signo] : true;
pcntl_signal($signo, SIG_DFL, $restartSyscalls);
pcntl_sigprocmask(SIG_UNBLOCK, array($signo), $oldset);
posix_kill(posix_getpid(), $signo);
pcntl_signal_dispatch();
pcntl_sigprocmask(SIG_SETMASK, $oldset);
pcntl_signal($signo, array($this, 'handleSignal'), $restartSyscalls);
}
} elseif (is_callable($this->previousSignalHandler[$signo])) {
if (PHP_VERSION_ID >= 70100) {
$this->previousSignalHandler[$signo]($signo, $siginfo);
} else {
$this->previousSignalHandler[$signo]($signo);
}
}
}
}