[Console] Add ability to schedule alarm signals and a console.alarm event

Author: HypeMC

Application.php

@@ -22,6 +22,7 @@
 use Symfony\Component\Console\Completion\CompletionInput;
 use Symfony\Component\Console\Completion\CompletionSuggestions;
 use Symfony\Component\Console\Completion\Suggestion;
+use Symfony\Component\Console\Event\ConsoleAlarmEvent;
 use Symfony\Component\Console\Event\ConsoleCommandEvent;
 use Symfony\Component\Console\Event\ConsoleErrorEvent;
 use Symfony\Component\Console\Event\ConsoleSignalEvent;
@@ -88,6 +89,7 @@ class Application implements ResetInterface
     private bool $initialized = false;
     private ?SignalRegistry $signalRegistry = null;
     private array $signalsToDispatchEvent = [];
+    private ?int $alarmInterval = null;
 
     public function __construct(
         private string $name = 'UNKNOWN',
@@ -97,7 +99,7 @@ public function __construct(
         $this->defaultCommand = 'list';
         if (\defined('SIGINT') && SignalRegistry::isSupported()) {
             $this->signalRegistry = new SignalRegistry();
-            $this->signalsToDispatchEvent = [\SIGINT, \SIGQUIT, \SIGTERM, \SIGUSR1, \SIGUSR2];
+            $this->signalsToDispatchEvent = [\SIGINT, \SIGQUIT, \SIGTERM, \SIGUSR1, \SIGUSR2, \SIGALRM];
         }
     }
 
@@ -128,6 +130,22 @@ public function setSignalsToDispatchEvent(int ...$signalsToDispatchEvent): void
         $this->signalsToDispatchEvent = $signalsToDispatchEvent;
     }
 
+    /**
+     * Sets the interval to schedule a SIGALRM signal in seconds.
+     */
+    public function setAlarmInterval(?int $seconds): void
+    {
+        $this->alarmInterval = $seconds;
+        $this->scheduleAlarm();
+    }
+
+    private function scheduleAlarm(): void
+    {
+        if (null !== $this->alarmInterval) {
+            $this->getSignalRegistry()->scheduleAlarm($this->alarmInterval);
+        }
+    }
+
     /**
      * Runs the current application.
      *
@@ -981,34 +999,47 @@ protected function doRunCommand(Command $command, InputInterface $input, OutputI
 
         $commandSignals = $command instanceof SignalableCommandInterface ? $command->getSubscribedSignals() : [];
         if ($commandSignals || $this->dispatcher && $this->signalsToDispatchEvent) {
-            if (!$this->signalRegistry) {
-                throw new RuntimeException('Unable to subscribe to signal events. Make sure that the "pcntl" extension is installed and that "pcntl_*" functions are not disabled by your php.ini\'s "disable_functions" directive.');
-            }
+            $signalRegistry = $this->getSignalRegistry();
 
             if (Terminal::hasSttyAvailable()) {
                 $sttyMode = shell_exec('stty -g');
 
                 foreach ([\SIGINT, \SIGQUIT, \SIGTERM] as $signal) {
-                    $this->signalRegistry->register($signal, static fn () => shell_exec('stty '.$sttyMode));
+                    $signalRegistry->register($signal, static fn () => shell_exec('stty '.$sttyMode));
                 }
             }
 
             if ($this->dispatcher) {
                 // We register application signals, so that we can dispatch the event
                 foreach ($this->signalsToDispatchEvent as $signal) {
-                    $event = new ConsoleSignalEvent($command, $input, $output, $signal);
-
-                    $this->signalRegistry->register($signal, function ($signal) use ($event, $command, $commandSignals) {
-                        $this->dispatcher->dispatch($event, ConsoleEvents::SIGNAL);
-                        $exitCode = $event->getExitCode();
+                    $signalEvent = new ConsoleSignalEvent($command, $input, $output, $signal);
+                    $alarmEvent = \SIGALRM === $signal ? new ConsoleAlarmEvent($command, $input, $output) : null;
+
+                    $signalRegistry->register($signal, function ($signal) use ($signalEvent, $alarmEvent, $command, $commandSignals, $input, $output) {
+                        $this->dispatcher->dispatch($signalEvent, ConsoleEvents::SIGNAL);
+                        $exitCode = $signalEvent->getExitCode();
+
+                        if (null !== $alarmEvent) {
+                            if (false !== $exitCode) {
+                                $alarmEvent->setExitCode($exitCode);
+                            } else {
+                                $alarmEvent->abortExit();
+                            }
+                            $this->dispatcher->dispatch($alarmEvent);
+                            $exitCode = $alarmEvent->getExitCode();
+                        }
 
                         // If the command is signalable, we call the handleSignal() method
                         if (\in_array($signal, $commandSignals, true)) {
                             $exitCode = $command->handleSignal($signal, $exitCode);
                         }
 
+                        if (\SIGALRM === $signal) {
+                            $this->scheduleAlarm();
+                        }
+
                         if (false !== $exitCode) {
-                            $event = new ConsoleTerminateEvent($command, $event->getInput(), $event->getOutput(), $exitCode, $signal);
+                            $event = new ConsoleTerminateEvent($command, $input, $output, $exitCode, $signal);
                             $this->dispatcher->dispatch($event, ConsoleEvents::TERMINATE);
 
                             exit($event->getExitCode());
@@ -1021,7 +1052,11 @@ protected function doRunCommand(Command $command, InputInterface $input, OutputI
             }
 
             foreach ($commandSignals as $signal) {
-                $this->signalRegistry->register($signal, function (int $signal) use ($command): void {
+                $signalRegistry->register($signal, function (int $signal) use ($command): void {
+                    if (\SIGALRM === $signal) {
+                        $this->scheduleAlarm();
+                    }
+
                     if (false !== $exitCode = $command->handleSignal($signal)) {
                         exit($exitCode);
                     }

CHANGELOG.md

@@ -9,6 +9,7 @@ CHANGELOG
  * [BC BREAK] Add silent verbosity (`--silent`/`SHELL_VERBOSITY=-2`) to suppress all output, including errors
  * Add `OutputInterface::isSilent()`, `Output::isSilent()`, `OutputStyle::isSilent()` methods
  * Add a configurable finished indicator to the progress indicator to show that the progress is finished
+ * Add ability to schedule alarm signals and a `ConsoleAlarmEvent`
 
 7.1
 ---

Event/ConsoleAlarmEvent.php

@@ -0,0 +1,47 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Console\Event;
+
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class ConsoleAlarmEvent extends ConsoleEvent
+{
+    public function __construct(
+        Command $command,
+        InputInterface $input,
+        OutputInterface $output,
+        private int|false $exitCode = 0,
+    ) {
+        parent::__construct($command, $input, $output);
+    }
+
+    public function setExitCode(int $exitCode): void
+    {
+        if ($exitCode < 0 || $exitCode > 255) {
+            throw new \InvalidArgumentException('Exit code must be between 0 and 255.');
+        }
+
+        $this->exitCode = $exitCode;
+    }
+
+    public function abortExit(): void
+    {
+        $this->exitCode = false;
+    }
+
+    public function getExitCode(): int|false
+    {
+        return $this->exitCode;
+    }
+}

SignalRegistry/SignalRegistry.php

@@ -54,4 +54,12 @@ public function handle(int $signal): void
             $signalHandler($signal, $hasNext);
         }
     }
+
+    /**
+     * @internal
+     */
+    public function scheduleAlarm(int $seconds): void
+    {
+        pcntl_alarm($seconds);
+    }
 }