Add fiber adapter based on suspensions (#2)

Author: kelunik

composer.json

@@ -13,6 +13,7 @@
     },
     "require": {
         "php": ">=8.1",
+        "react/async": "^4",
         "react/event-loop": "^0.5 || ^1",
         "revolt/event-loop": "^0.2.4"
     },
@@ -33,11 +34,13 @@
     "autoload-dev": {
         "psr-4": {
             "Revolt\\EventLoop\\React\\": "test",
+            "React\\Tests\\Async\\": "vendor/react/async/tests",
             "React\\Tests\\EventLoop\\": "vendor/react/event-loop/tests"
         }
     },
     "config": {
         "preferred-install": {
+            "react/async": "source",
             "react/event-loop": "source"
         }
     },

etc/Factory.php

@@ -2,8 +2,6 @@
 
 namespace React\EventLoop;
 
-use Revolt\EventLoop\Adapter\React\Internal\EventLoopAdapter;
-
 (static function () {
     $constName = 'REVOLT_ADAPTER_REACT_DISABLE_FACTORY_OVERRIDE';
 
@@ -14,16 +12,14 @@
     if (!$const && !$env) {
         /**
          * Class used to overwrite React's loop factory with an implementation throwing an error.
-         *
-         * @noinspection PhpUndefinedClassInspection
          */
         final class Factory
         {
             public static function create(): LoopInterface
             {
                 throw new \Error(
                     __METHOD__ . '() has been overridden by revolt/event-loop-adapter-react to prevent you from accidentally creating two event loop instances. ' .
-                    'Use ' . EventLoopAdapter::class . '::get() instead of React\EventLoop\Factory::create() to ensure everything is running on the same event loop. ' .
+                    'Use ' . Loop::class . '::get() instead of React\EventLoop\Factory::create() to ensure everything is running on the same event loop. ' .
                     'You may set a constant or environment variable named REVOLT_ADAPTER_REACT_DISABLE_FACTORY_OVERRIDE to disable this protection or open an issue at https://github.com/revoltphp/event-loop-adapter-react if you\'re unsure on the right way forward.'
                 );
             }

src/Internal/FiberAdapter.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Revolt\EventLoop\React\Internal;
+
+use React\Async\FiberInterface;
+use Revolt\EventLoop;
+
+/** @internal */
+final class FiberAdapter implements FiberInterface
+{
+    private ?EventLoop\Suspension $suspension = null;
+
+    public function resume(mixed $value): void
+    {
+        if ($this->suspension === null) {
+            throw new \Error('Must call suspend() before calling resume()');
+        }
+
+        $this->suspension->resume($value);
+
+        // Note: resume() above is async in revolt, but sync in react,
+        // so let's suspend here until the queued resumption above is executed.
+        $suspension = EventLoop::getSuspension();
+        EventLoop::queue($suspension->resume(...));
+        $suspension->suspend();
+    }
+
+    public function throw(\Throwable $throwable): void
+    {
+        if ($this->suspension === null) {
+            throw new \Error('Must call suspend() before calling throw()');
+        }
+
+        $this->suspension->throw($throwable);
+
+        // Note: throw() above is async in revolt, but sync in react,
+        // so let's suspend here until the queued throwing above is executed.
+        $suspension = EventLoop::getSuspension();
+        EventLoop::queue($suspension->resume(...));
+        $suspension->suspend();
+    }
+
+    public function suspend(): mixed
+    {
+        if ($this->suspension !== null) {
+            throw new \Error('Must call resume() or throw() before calling suspend() again');
+        }
+
+        $this->suspension = EventLoop::getSuspension();
+
+        return $this->suspension->suspend();
+    }
+}

src/bootstrap.php

@@ -1,9 +1,17 @@
 <?php
 
+use React\Async\FiberFactory;
+use React\Async\FiberInterface;
 use React\EventLoop\Loop;
 use Revolt\EventLoop\React\Internal\EventLoopAdapter;
+use Revolt\EventLoop\React\Internal\FiberAdapter;
 
 /**
  * @psalm-suppress InternalMethod
  */
 Loop::set(EventLoopAdapter::get());
+
+/**
+ * @psalm-suppress InternalMethod
+ */
+FiberFactory::factory(static fn (): FiberInterface => new FiberAdapter());

test/AwaitTest.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Revolt\EventLoop\React;
+
+use React;
+
+class AwaitTest extends React\Tests\Async\AwaitTest
+{
+    public function testExecutionOrder()
+    {
+        self::expectOutputString('acbd');
+
+        $deferred = new React\Promise\Deferred();
+
+        $promises[] = React\Async\async(function () use (&$deferred) {
+            print 'a';
+            React\Async\await($deferred->promise());
+            print 'b';
+        })();
+
+        $promises[] = React\Async\async(function () use ($deferred) {
+            print 'c';
+            $deferred->resolve();
+            print 'd';
+        })();
+
+        React\Async\await(React\Promise\all($promises));
+    }
+}

test/EvTest.php

@@ -14,6 +14,7 @@ public function createLoop(): LoopInterface
             $this->markTestSkipped("ext-ev required");
         }
 
+        self::clearGlobalLoop();
         EventLoop::setDriver(new EventLoop\Driver\EvDriver());
         return EventLoopAdapter::get();
     }

test/EvTimerTest.php

@@ -14,6 +14,7 @@ public function createLoop(): LoopInterface
             $this->markTestSkipped("ext-ev required");
         }
 
+        self::clearGlobalLoop();
         EventLoop::setDriver(new EventLoop\Driver\EvDriver());
         return EventLoopAdapter::get();
     }

test/EventTest.php

@@ -13,6 +13,7 @@ public function createLoop(): LoopInterface
             $this->markTestSkipped("ext-event required");
         }
 
+        self::clearGlobalLoop();
         EventLoop::setDriver(new EventLoop\Driver\EventDriver());
         return Internal\EventLoopAdapter::get();
     }

test/EventTimerTest.php

@@ -14,6 +14,7 @@ public function createLoop(): LoopInterface
             $this->markTestSkipped("ext-event required");
         }
 
+        self::clearGlobalLoop();
         EventLoop::setDriver(new EventLoop\Driver\EventDriver());
         return EventLoopAdapter::get();
     }

test/Test.php

@@ -13,8 +13,16 @@
 
 class Test extends AbstractLoopTest
 {
+    /** @noinspection PhpUndefinedFieldInspection */
+    protected static function clearGlobalLoop(): void
+    {
+        (static fn () => self::$driver = new EventLoop\Driver\StreamSelectDriver())
+            ->bindTo(null, EventLoop::class)();
+    }
+
     public function createLoop(): LoopInterface
     {
+        self::clearGlobalLoop();
         EventLoop::setDriver(new StreamSelectDriver());
         return EventLoopAdapter::get();
     }