Force waiting for child on shutdown

Author: trowski

src/Internal/Posix/PosixHandle.php

@@ -53,7 +53,7 @@ static function (string $callbackId, $stream) use (&$status, $deferred, $stdin,
 
                 \fclose($stream);
 
-                self::waitPid($shellPid);
+                self::asyncWaitPid($shellPid);
             },
         ));
     }
@@ -72,13 +72,13 @@ public function unreference(): void
         }
     }
 
-    private static function waitPid(int $pid): void
+    private static function asyncWaitPid(int $pid): void
     {
         if (self::hasChildExited($pid)) {
             return;
         }
 
-        EventLoop::unreference(EventLoop::defer(static fn () => self::waitPid($pid)));
+        EventLoop::unreference(EventLoop::defer(static fn () => self::asyncWaitPid($pid)));
     }
 
     private static function hasChildExited(int $pid): bool
@@ -97,6 +97,13 @@ public function __destruct()
             return;
         }
 
-        self::waitPid($this->shellPid);
+        self::asyncWaitPid($this->shellPid);
+    }
+
+    public function wait(): void
+    {
+        if (\extension_loaded('pcntl')) {
+            \pcntl_waitpid($this->pid, $status);
+        }
     }
 }

src/Internal/ProcHolder.php

@@ -12,8 +12,8 @@ final class ProcHolder
     use ForbidSerialization;
 
     public function __construct(
-        private readonly ProcessRunner $runner,
-        private readonly ProcessHandle $handle
+        public readonly ProcessRunner $runner,
+        public readonly ProcessHandle $handle,
     ) {
     }
 

src/Internal/ProcessHandle.php

@@ -37,4 +37,6 @@ public function __construct($proc)
         $this->joinDeferred = new DeferredFuture;
         $this->originalParentPid = \getmypid();
     }
+
+    abstract public function wait(): void;
 }

src/Internal/Windows/WindowsHandle.php

@@ -35,4 +35,9 @@ public function __construct($proc)
 
         $this->startBarrier = new Barrier(4);
     }
+
+    public function wait(): void
+    {
+        // Nothing to do.
+    }
 }

src/Process.php

@@ -26,13 +26,16 @@ final class Process
 
     private static \WeakMap $procHolder;
 
+    private static \WeakMap $streamHolder;
+
     /**
      * Starts a new process.
      *
      * @param string|list<string> $command Command to run.
      * @param string|null $workingDirectory Working directory, or an empty string to use the working directory of the
      *     parent.
-     * @param array<string, string> $environment Environment variables, or use an empty array to inherit from the parent.
+     * @param array<string, string> $environment Environment variables, or use an empty array to inherit from the
+     *     parent.
      * @param array<string, bool> $options Options for {@see proc_open()}.
      *
      * @throws ProcessException If starting the process fails.
@@ -59,14 +62,6 @@ public static function start(
             ? \implode(" ", \array_map(escapeArgument(...), $command))
             : $command;
 
-        $driver = EventLoop::getDriver();
-
-        /** @psalm-suppress RedundantPropertyInitializationCheck */
-        self::$driverRunner ??= new \WeakMap();
-        self::$driverRunner[$driver] ??= \PHP_OS_FAMILY === 'Windows'
-            ? new WindowsProcessRunner()
-            : new PosixProcessRunner();
-
         if (!$workingDirectory) {
             $cwd = \getcwd();
             if ($cwd === false) {
@@ -76,7 +71,10 @@ public static function start(
             $workingDirectory = $cwd;
         }
 
-        $runner = self::$driverRunner[$driver];
+        $driver = EventLoop::getDriver();
+
+        $runner = self::$driverRunner[$driver] ??= self::initialize();
+
         $context = $runner->start(
             $command,
             $cancellation ?? new NullCancellation(),
@@ -90,13 +88,38 @@ public static function start(
 
         $procHolder = new ProcHolder($runner, $handle);
 
+        self::$streamHolder[$streams->stdin] = $procHolder;
+        self::$streamHolder[$streams->stdout] = $procHolder;
+        self::$streamHolder[$streams->stderr] = $procHolder;
+
+        self::$procHolder[$procHolder] = $handle->pid;
+
+        return new self($runner, $handle, $streams, $command, $workingDirectory, $envVars, $options);
+    }
+
+    private static function initialize(): ProcessRunner
+    {
+        /** @psalm-suppress RedundantPropertyInitializationCheck */
+        self::$driverRunner ??= new \WeakMap();
+
         /** @psalm-suppress RedundantPropertyInitializationCheck */
         self::$procHolder ??= new \WeakMap();
-        self::$procHolder[$streams->stdin] = $procHolder;
-        self::$procHolder[$streams->stdout] = $procHolder;
-        self::$procHolder[$streams->stderr] = $procHolder;
 
-        return new self($runner, $handle, $streams, $command, $workingDirectory, $envVars, $options);
+        /** @psalm-suppress RedundantPropertyInitializationCheck */
+        self::$streamHolder ??= new \WeakMap();
+
+        $runner = \PHP_OS_FAMILY === 'Windows'
+            ? new WindowsProcessRunner()
+            : new PosixProcessRunner();
+
+        \register_shutdown_function(static function (): void {
+            /** @var ProcHolder $procHolder */
+            foreach (self::$procHolder as $procHolder => $pid) {
+                $procHolder->handle->wait();
+            }
+        });
+
+        return $runner;
     }
 
     /**