Allow any serializable callable

src/Internal/ParallelTask.php

@@ -25,6 +25,14 @@ class ParallelTask implements Task {
     public function run(Environment $environment) {
         $callable = \unserialize($this->function, ['allowed_classes' => true]);
 
+        if ($callable instanceof \__PHP_Incomplete_Class) {
+            throw new \Error('When using a class instance as a callable, the class must be autoloadable');
+        }
+
+        if (\is_array($callable) && $callable[0] instanceof \__PHP_Incomplete_Class) {
+            throw new \Error('When using a class instance method as a callable, the class must be autoloadable');
+        }
+
         return $callable(...$this->args);
     }
 }

src/functions.php

@@ -4,7 +4,6 @@ namespace Amp\ParallelFunctions;
 
 use Amp\MultiReasonException;
 use Amp\Parallel\Worker\Pool;
-use Amp\ParallelFunctions\Internal\ParallelTask;
 use Amp\Promise;
 use Opis\Closure\SerializableClosure;
 use function Amp\call;
@@ -22,19 +21,17 @@ use function Amp\Promise\any;
  */
 function parallel(callable $callable, Pool $pool = null): callable {
     try {
-        if (\is_string($callable)) {
+        if ($callable instanceof \Closure) {
-            $payload = \serialize($callable);
+            $callable = new SerializableClosure($callable);
-        } elseif ($callable instanceof \Closure) {
-            $payload = \serialize(new SerializableClosure($callable));
-        } else {
-            throw new \Error('Unsupported callable type: ' . \gettype($callable));
         }
+
+        $payload = \serialize($callable);
     } catch (\Exception $e) {
-        throw new \Error('Unsupported callable: ' . $e->getMessage());
+        throw new \Error('Unsupported callable: ' . $e->getMessage(), 0, $e);
     }
 
     return function (...$args) use ($pool, $payload): Promise {
-        $task = new ParallelTask($payload, $args);
+        $task = new Internal\ParallelTask($payload, $args);
         return $pool ? $pool->enqueue($task) : enqueue($task);
     };
 }

test/Fixture/TestCallables.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Amp\ParallelFunctions\Test\Fixture;
+
+class TestCallables {
+    public static function staticMethod(int $value): int {
+        return $value + 1;
+    }
+
+    public function instanceMethod(int $value): int {
+        return $value + 2;
+    }
+
+    public function __invoke(int $value) {
+        return $value + 3;
+    }
+}

test/ParallelTest.php

@@ -3,11 +3,23 @@
 namespace Amp\ParallelFunctions\Test;
 
 use Amp\Parallel\Worker\Pool;
+use Amp\ParallelFunctions\Test\Fixture\TestCallables;
 use Amp\PHPUnit\TestCase;
 use Amp\Promise;
 use Amp\Success;
 use function Amp\ParallelFunctions\parallel;
 
+class UnserializableClass {
+    public function __invoke() {
+    }
+
+    public function instanceMethod() {
+    }
+
+    public static function staticMethod() {
+    }
+}
+
 class ParallelTest extends TestCase {
     /**
      * @expectedException \Error
@@ -33,4 +45,75 @@ class ParallelTest extends TestCase {
 
         $this->assertSame(1, Promise\wait($callable()));
     }
+
+    public function testClassStaticMethod() {
+        $callable = [TestCallables::class, 'staticMethod'];
+        $result = $callable(1);
+        $callable = parallel($callable);
+
+        $this->assertSame($result, Promise\wait($callable(1)));
+    }
+
+    public function testClassInstanceMethod() {
+        $instance = new TestCallables;
+
+        $callable = [$instance, 'instanceMethod'];
+        $result = $callable(1);
+        $callable = parallel($callable);
+
+        $this->assertSame($result, Promise\wait($callable(1)));
+    }
+
+    public function testCallableClass() {
+        $callable = new TestCallables;
+        $result = $callable(1);
+        $callable = parallel($callable);
+
+        $this->assertSame($result, Promise\wait($callable(1)));
+    }
+
+    public function testUnserializableCallable() {
+        $this->expectException(\Error::class);
+        $this->expectExceptionMessage("Unsupported callable: Serialization of 'class@anonymous' is not allowed");
+
+        $callable = new class {
+            public function __invoke() {
+            }
+        };
+
+        $callable = parallel($callable);
+    }
+
+    public function testUnserializableClassInstance() {
+        $this->expectException(\Error::class);
+        $this->expectExceptionMessage('Uncaught Error in worker with message "When using a class instance as a callable, the class must be autoloadable"');
+
+        $callable = new UnserializableClass;
+
+        $callable = parallel($callable);
+
+        Promise\wait($callable());
+    }
+
+    public function testUnserializableClassInstanceMethod() {
+        $this->expectException(\Error::class);
+        $this->expectExceptionMessage('Uncaught Error in worker with message "When using a class instance method as a callable, the class must be autoloadable"');
+
+        $callable = [new UnserializableClass, 'instanceMethod'];
+
+        $callable = parallel($callable);
+
+        Promise\wait($callable());
+    }
+
+    public function testUnserializableClassStaticMethod() {
+        $this->expectException(\Error::class);
+        $this->expectExceptionMessage('Uncaught Error in worker with message "Class \'Amp\\ParallelFunctions\\Test\\UnserializableClass\' not found"');
+
+        $callable = [UnserializableClass::class, 'staticMethod'];
+
+        $callable = parallel($callable);
+
+        Promise\wait($callable());
+    }
 }