Fix Context cycle collection and GC ownership

context.c

@@ -365,18 +365,30 @@ static zend_object *context_object_create(zend_class_entry *class_entry)
 	return &context->std;
 }
 
-static void context_object_destroy(zend_object *object)
+static void context_free(zend_object *object)
 {
 	async_context_t *context = ZEND_OBJECT_TO_CONTEXT(object);
 
-	// Destroy hash tables
 	zend_hash_destroy(&context->values);
 	zend_hash_destroy(&context->keys);
+	zend_object_std_dtor(object);
 }
 
-static void context_free(zend_object *object)
+static HashTable *context_get_gc(zend_object *object, zval **table, int *num)
 {
-	zend_object_std_dtor(object);
+	async_context_t *context = ZEND_OBJECT_TO_CONTEXT(object);
+	zend_get_gc_buffer *buf = zend_get_gc_buffer_create();
+	zval *value;
+
+	ZEND_HASH_FOREACH_VAL(&context->values, value) {
+		zend_get_gc_buffer_add_zval(buf, value);
+	} ZEND_HASH_FOREACH_END();
+
+	ZEND_HASH_FOREACH_VAL(&context->keys, value) {
+		zend_get_gc_buffer_add_zval(buf, value);
+	} ZEND_HASH_FOREACH_END();
+	zend_get_gc_buffer_use(buf, table, num);
+	return NULL;
 }
 
 void async_register_context_ce(void)
@@ -391,8 +403,8 @@ void async_register_context_ce(void)
 	context_handlers = std_object_handlers;
 	context_handlers.offset = offsetof(async_context_t, std);
 	context_handlers.clone_obj = NULL;
-	context_handlers.dtor_obj = context_object_destroy;
 	context_handlers.free_obj = context_free;
+	context_handlers.get_gc = context_get_gc;
 
 	async_ce_context->default_object_handlers = &context_handlers;
-}
+}

coroutine.c

@@ -329,25 +329,10 @@ static HashTable *async_coroutine_object_gc(zend_object *object, zval **table, i
 		}
 	}
 
-	/* Add context ZVALs if present */
+	/* The coroutine owns the Context object, which exposes its values and keys to GC. */
 	if (coroutine->coroutine.context) {
-		/* Cast to actual context implementation to access HashTables */
 		async_context_t *context = (async_context_t *) coroutine->coroutine.context;
-
-		/* Add all values from context->values HashTable */
-		zval *val;
-		ZEND_HASH_FOREACH_VAL(&context->values, val)
-		{
-			zend_get_gc_buffer_add_zval(buf, val);
-		}
-		ZEND_HASH_FOREACH_END();
-
-		/* Add all object keys from context->keys HashTable */
-		ZEND_HASH_FOREACH_VAL(&context->keys, val)
-		{
-			zend_get_gc_buffer_add_zval(buf, val);
-		}
-		ZEND_HASH_FOREACH_END();
+		zend_get_gc_buffer_add_obj(buf, &context->std);
 	}
 
 	async_fiber_context_t *fiber_context = coroutine->fiber_context;

scope.c

@@ -1448,25 +1448,10 @@ static HashTable *scope_object_gc(zend_object *object, zval **table, int *num)
 		ZEND_HASH_FOREACH_END();
 	}
 
-	/* Add context ZVALs if present */
+	/* The scope owns the Context object, which exposes its values and keys to GC. */
 	if (scope->scope.context) {
-		/* Cast to actual context implementation to access HashTables */
 		async_context_t *context = (async_context_t *) scope->scope.context;
-
-		/* Add all values from context->values HashTable */
-		zval *val;
-		ZEND_HASH_FOREACH_VAL(&context->values, val)
-		{
-			zend_get_gc_buffer_add_zval(buf, val);
-		}
-		ZEND_HASH_FOREACH_END();
-
-		/* Add all object keys from context->keys HashTable */
-		ZEND_HASH_FOREACH_VAL(&context->keys, val)
-		{
-			zend_get_gc_buffer_add_zval(buf, val);
-		}
-		ZEND_HASH_FOREACH_END();
+		zend_get_gc_buffer_add_obj(buf, &context->std);
 	}
 
 	zend_get_gc_buffer_use(buf, table, num);
@@ -1751,4 +1736,4 @@ static bool async_scope_call_finally_handlers(async_scope_t *scope)
 	} else {
 		return true;
 	}
-}
+}

tests/context/014-context_cycles_gc.phpt

@@ -0,0 +1,61 @@
+--TEST--
+Context values and object keys are visible to normal cycle collection
+--FILE--
+<?php
+
+function abandonContext(bool $asKey): WeakReference
+{
+    $context = new Async\Context();
+
+    if ($asKey) {
+        $context->set($context, 'value');
+    } else {
+        $context->set('key', $context);
+    }
+
+    return WeakReference::create($context);
+}
+
+$valueCycle = abandonContext(false);
+$keyCycle = abandonContext(true);
+
+// Fill the GC root buffer and let the collector run on its normal schedule.
+$threshold = gc_status()['threshold'];
+for ($i = 0; $i < $threshold + 64; $i++) {
+    abandonContext(($i & 1) !== 0);
+}
+
+var_dump($valueCycle->get() === null);
+var_dump($keyCycle->get() === null);
+
+$coroutineContext = null;
+Async\await(Async\spawn(function () use (&$coroutineContext): void {
+    $context = Async\coroutine_context();
+    $coroutineContext = WeakReference::create($context);
+    $context->set('self', $context);
+}));
+
+gc_collect_cycles();
+Async\delay(1);
+var_dump($coroutineContext->get() === null);
+
+$scope = new Async\Scope();
+$scopeContext = null;
+Async\await($scope->spawn(function () use (&$scopeContext): void {
+    $context = Async\current_context();
+    $scopeContext = WeakReference::create($context);
+    $context->set($context, 'self');
+}));
+$scope->dispose();
+unset($scope);
+
+gc_collect_cycles();
+Async\delay(1);
+var_dump($scopeContext->get() === null);
+
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(true)
+bool(true)