Release v4.0 (#6)

* Add php 8.2 support

* Fix bug #4, remove EventDispatcher and general touch-ups (#5)

README.md

@@ -30,34 +30,6 @@ the `wait()` method automatically at the end of the script. If you do not want t
 first argument to the constructor to disable the shutdown handler. If you disable this feature, the process manager will
 force a child termination even if they aren't finished yet and exits with status-code `125`.
 
-## Event Dispatcher Support
-
-This library supports the event dispatcher component of Symfony. You can inject the event-listener to
-the `ProcessManager` to dispatch events during program runtime.
-
-**Please note that events will only be dispatched for the parent/main process.**
-
-```php
-$eventManager = new EventDispatcher();
-$eventManager->addListener(ProcessManager::EVENT_CHILD_CREATED, function (ProcessManagerEvent $event) {
-    echo sprintf("Child created: %d\n", $event->getProcessId());
-});
-
-$pm = new ProcessManager();
-$pm->setEventDispatcher($eventManager);
-
-// ...
-```
-
-The following events are thrown:
-
-| Event                           | Description                                |
-|---------------------------------|--------------------------------------------|
-| process.manager.fork.failed     | Forking of the process failed.             |
-| process.manager.child.created   | Fork was created successfully.             |
-| process.manager.child.exit      | A child has exited.                        |
-| process.manager.child.send.kill | A kill signal was sent to a child process. |
-
 ## Inter Process Communication
 
 You can send data between the parent and child process using messages.
@@ -119,7 +91,7 @@ for($i = 0; $i < 100; $i++) {
 
 // wait and cleanup
 sleep(5);
-$pool->killAll();
+$pool->closePool();
 ```
 
 ## Example
@@ -184,4 +156,4 @@ D
 --> All Work done!
 ```
 
-More examples including the `EventDispatcher` can be found in the [example](./example) folder.
+More examples can be found in the [example](./example) folder.

composer.json

@@ -10,13 +10,13 @@
         }
     ],
     "require": {
-        "php": "^8.1 | ^8.2",
+        "php": ">=8.2",
         "ext-pcntl": "*",
         "ext-posix": "*",
         "ext-sockets": "*"
     },
-    "suggest": {
-        "symfony/event-dispatcher": "If you want to add events, you can use the symfony event dispatcher."
+    "conflict": {
+        "ext-grpc": "*"
     },
     "autoload": {
         "psr-4": {

example/000_simple.php

@@ -2,23 +2,11 @@
 
 use Sweikenb\Library\Pcntl\Api\ChildProcessInterface;
 use Sweikenb\Library\Pcntl\Api\ParentProcessInterface;
-use Sweikenb\Library\Pcntl\Event\ProcessManagerEvent;
 use Sweikenb\Library\Pcntl\ProcessManager;
-use Symfony\Component\EventDispatcher\EventDispatcher;
 
 require __DIR__ . '/../vendor/autoload.php';
 
 $pm = new ProcessManager();
-if (class_exists(EventDispatcher::class)) {
-    /*
-     * Register events in case the Symfony EventDispatcher is available
-     */
-    $eventManager = new EventDispatcher();
-    $eventManager->addListener(ProcessManager::EVENT_CHILD_CREATED, function (ProcessManagerEvent $event) {
-        echo sprintf("[EVENT CALLBACK] Child created: %d\n", $event->getProcessId());
-    });
-    $pm->setEventDispatcher($eventManager);
-}
 
 $childA = $pm->runProcess(
     function (ChildProcessInterface $childProcess, ParentProcessInterface $parentProcess) {

example/100_simple_ipc.php

@@ -70,6 +70,6 @@ function (ChildProcessInterface $process, ParentProcessInterface $parentProcess)
     }
 
     // stop the worker process
-    fwrite(STDOUT, sprintf('# Stopping worker (%d)', $worker->getId()));
+    fwrite(STDOUT, sprintf("# Stopping worker (%d)\n", $worker->getId()));
     $worker->kill();
 }

example/110_process_pool.php

@@ -21,6 +21,6 @@
 // Usually you would send messages in some kid of event/endless-loop and/or with some custom unblock logic.
 sleep(3);
 
-// Work done, kill all workers!
-// HINT: if you skipp this kill, the main process and its worker will run infinitely
-$pool->killAll();
+// Work done, kill all workers and disable the pool. No more messages can be processed.
+// This will be called automatically if the main process terminated.
+$pool->closePool();

src/Api/ProcessManagerInterface.php

@@ -24,5 +24,5 @@ public function runProcess(callable $callback): ChildProcessInterface;
      *
      * Only works in the parent-process.
      */
-    public function wait(?callable $callback = null): ProcessManagerInterface;
+    public function wait(?callable $callback = null): void;
 }

src/Api/ProcessPoolInterface.php

@@ -10,5 +10,5 @@ public function getInvocationBuilder(): callable;
 
     public function sendMessage(WorkerMessageInterface $workerMessage): bool;
 
-    public function killAll(): void;
+    public function closePool(): void;
 }

src/Model/ChildProcessModel.php

@@ -8,6 +8,6 @@ class ChildProcessModel extends AbstractProcessModel implements ChildProcessInte
 {
     public function kill(): void
     {
-        @posix_kill($this->getId(), SIGKILL);
+        posix_kill($this->getId(), SIGKILL);
     }
 }

src/ProcessManager.php

@@ -2,37 +2,34 @@
 
 namespace Sweikenb\Library\Pcntl;
 
+use Exception;
 use Sweikenb\Library\Pcntl\Api\ChildProcessInterface;
 use Sweikenb\Library\Pcntl\Api\ParentProcessInterface;
 use Sweikenb\Library\Pcntl\Api\ProcessFactoryInterface;
 use Sweikenb\Library\Pcntl\Api\ProcessManagerInterface;
-use Sweikenb\Library\Pcntl\Event\ProcessManagerEvent;
 use Sweikenb\Library\Pcntl\Exception\ProcessException;
 use Sweikenb\Library\Pcntl\Factory\ProcessFactory;
-use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Throwable;
 
 class ProcessManager implements ProcessManagerInterface
 {
-    const EVENT_FORK_FAILED = 'process.manager.fork.failed';
-    const EVENT_CHILD_CREATED = 'process.manager.child.created';
-    const EVENT_CHILD_EXIT = 'process.manager.child.exit';
-    const EVENT_CHILD_SEND_KILL = 'process.manager.child.send.kill';
-
     const PROPAGATE_SIGNALS = [
         SIGTERM,
         SIGHUP,
-        SIGUSR1,
         SIGALRM,
+        SIGUSR1,
+        SIGUSR2
     ];
-
-    private ?EventDispatcherInterface $eventDispatcher = null;
     private ProcessFactoryInterface $processFactory;
     private ParentProcessInterface $mainProcess;
-
     /**
      * @var array<int, ChildProcessInterface>
      */
     private array $childProcesses = [];
+    /**
+     * @var array<int, int>
+     */
+    private array $earlyExitChildQueue = [];
     private bool $isChildProcess = false;
 
     public function __construct(
@@ -51,8 +48,11 @@ public function __construct(
             ? self::PROPAGATE_SIGNALS
             : $propagateSignals;
 
+        // register a signale queue for early exit children
+        pcntl_async_signals(false);
+        pcntl_signal(SIGCHLD, [$this, "childEarlyExitQueue"]);
+
         // register the signal-handler for each signal that should be handled
-        pcntl_async_signals(true);
         foreach ($propagateSignals as $handleSignal) {
             pcntl_signal(
                 $handleSignal,
@@ -72,11 +72,13 @@ function () use ($autoWait) {
                 } else {
                     if (!empty($this->childProcesses)) {
                         foreach ($this->childProcesses as $childProcess) {
-                            echo sprintf(
-                                "[PCNTL ProcessManager] Forcing child process exit for pid %s\n",
-                                $childProcess->getId()
+                            fwrite(
+                                STDERR,
+                                sprintf(
+                                    "[PCNTL ProcessManager] Forcing child process exit for pid %s\n",
+                                    $childProcess->getId()
+                                )
                             );
-                            $this->dispatchEvent(self::EVENT_CHILD_SEND_KILL, $childProcess->getId());
                             @posix_kill($childProcess->getId(), SIGKILL);
                         }
                         $this->wait();
@@ -89,16 +91,12 @@ function () use ($autoWait) {
         );
     }
 
-    public function setEventDispatcher(EventDispatcherInterface $eventDispatcher): void
-    {
-        $this->eventDispatcher = $eventDispatcher;
-    }
-
-    private function dispatchEvent(string $name, ?int $pid = null): void
+    public function childEarlyExitQueue(): void
     {
-        if ($this->eventDispatcher) {
-            $event = new ProcessManagerEvent($name, $pid);
-            $this->eventDispatcher->dispatch($event, $name);
+        if (!$this->isChildProcess) {
+            while (($pid = pcntl_waitpid(-1, $status, WNOHANG)) > 0) {
+                $this->earlyExitChildQueue[$pid] = [$pid, pcntl_wexitstatus($status)];
+            }
         }
     }
 
@@ -125,7 +123,6 @@ public function runProcess(callable $callback): ChildProcessInterface
 
         // error
         if ($pid < 0) {
-            $this->dispatchEvent(self::EVENT_FORK_FAILED);
             throw new ProcessException('Forking failed.');
         }
 
@@ -134,8 +131,6 @@ public function runProcess(callable $callback): ChildProcessInterface
             @socket_close($ipc[0]);
             $childProcess = $this->processFactory->createChildProcess($pid, $ipc[1]);
             $this->childProcesses[$pid] = $childProcess;
-            $this->dispatchEvent(self::EVENT_CHILD_CREATED, $pid);
-
             return $childProcess;
         }
 
@@ -144,33 +139,47 @@ public function runProcess(callable $callback): ChildProcessInterface
             @socket_close($ipc[1]);
             $this->childProcesses = [];
             $this->isChildProcess = true;
-            call_user_func(
-                $callback,
-                $this->processFactory->createChildProcess(posix_getpid(), null),
-                $this->getMainProcess()->setIpcSocket($ipc[0])
+            $success = false !== call_user_func(
+                    $callback,
+                    $this->processFactory->createChildProcess(posix_getpid(), null),
+                    $this->getMainProcess()->setIpcSocket($ipc[0])
+                );
+        } catch (Exception | Throwable $e) {
+            $success = false;
+            fwrite(
+                STDERR,
+                sprintf("[PCNTL ProcessManager] Child process exception: %s\n", $e->getMessage())
             );
         } finally {
-            exit(0);
+            exit($success ? 0 : 1);
         }
     }
 
-    public function wait(?callable $callback = null): ProcessManagerInterface
+    public function wait(?callable $callback = null): void
     {
-        if (!$this->isChildProcess) {
-            while (!empty($this->childProcesses)) {
-                $pid = pcntl_wait($status);
+        if ($this->isChildProcess) {
+            return;
+        }
+        $handleChildExit = function (int $pid, int $status) use ($callback): void {
+            if ($pid > 0) {
                 if (isset($this->childProcesses[$pid])) {
                     unset($this->childProcesses[$pid]);
-
-                    // dispatch event and trigger callback if present
-                    $this->dispatchEvent(self::EVENT_CHILD_EXIT, $pid);
-                    if (null !== $callback) {
-                        call_user_func($callback, $status, $pid);
-                    }
+                }
+                if (isset($this->earlyExitChildQueue[$pid])) {
+                    unset($this->earlyExitChildQueue[$pid]);
+                }
+                if (null !== $callback) {
+                    call_user_func($callback, $status, $pid);
                 }
             }
+        };
+        while (!empty($this->earlyExitChildQueue)) {
+            [$pid, $status] = current($this->earlyExitChildQueue);
+            $handleChildExit($pid, $status);
+        }
+        while (!empty($this->childProcesses)) {
+            $pid = pcntl_wait($status);
+            $handleChildExit($pid, $status);
         }
-
-        return $this;
     }
 }