Allow creating Graceful/UnwindExit and use when destroying a fiber (#7174)

Direct creation of GracefulExit allows the the special exception object to be transfered and thrown into a destroyed fiber using the same path as any other exception thrown into a fiber instead of needing to check for a flag.

Author: trowski

Zend/zend_exceptions.c

@@ -1002,18 +1002,28 @@ ZEND_API ZEND_COLD void zend_throw_exception_object(zval *exception) /* {{{ */
 }
 /* }}} */
 
+ZEND_API ZEND_COLD zend_object *zend_create_unwind_exit(void)
+{
+	return zend_objects_new(&zend_ce_unwind_exit);
+}
+
+ZEND_API ZEND_COLD zend_object *zend_create_graceful_exit(void)
+{
+	return zend_objects_new(&zend_ce_graceful_exit);
+}
+
 ZEND_API ZEND_COLD void zend_throw_unwind_exit(void)
 {
 	ZEND_ASSERT(!EG(exception));
-	EG(exception) = zend_objects_new(&zend_ce_unwind_exit);
+	EG(exception) = zend_create_unwind_exit();
 	EG(opline_before_exception) = EG(current_execute_data)->opline;
 	EG(current_execute_data)->opline = EG(exception_op);
 }
 
 ZEND_API ZEND_COLD void zend_throw_graceful_exit(void)
 {
 	ZEND_ASSERT(!EG(exception));
-	EG(exception) = zend_objects_new(&zend_ce_graceful_exit);
+	EG(exception) = zend_create_graceful_exit();
 	EG(opline_before_exception) = EG(current_execute_data)->opline;
 	EG(current_execute_data)->opline = EG(exception_op);
 }

Zend/zend_exceptions.h

@@ -71,6 +71,8 @@ ZEND_API ZEND_COLD zend_result zend_exception_error(zend_object *exception, int
 ZEND_NORETURN void zend_exception_uncaught_error(const char *prefix, ...) ZEND_ATTRIBUTE_FORMAT(printf, 1, 2);
 ZEND_API zend_string *zend_trace_to_string(HashTable *trace, bool include_main);
 
+ZEND_API ZEND_COLD zend_object *zend_create_unwind_exit(void);
+ZEND_API ZEND_COLD zend_object *zend_create_graceful_exit(void);
 ZEND_API ZEND_COLD void zend_throw_unwind_exit(void);
 ZEND_API ZEND_COLD void zend_throw_graceful_exit(void);
 ZEND_API bool zend_is_unwind_exit(const zend_object *ex);

Zend/zend_fibers.c

@@ -539,9 +539,14 @@ static void zend_fiber_object_destroy(zend_object *object)
 	zend_object *exception = EG(exception);
 	EG(exception) = NULL;
 
+	zval graceful_exit;
+	ZVAL_OBJ(&graceful_exit, zend_create_graceful_exit());
+
 	fiber->flags |= ZEND_FIBER_FLAG_DESTROYED;
 
-	zend_fiber_transfer transfer = zend_fiber_resume(fiber, NULL, false);
+	zend_fiber_transfer transfer = zend_fiber_resume(fiber, &graceful_exit, true);
+
+	zval_ptr_dtor(&graceful_exit);
 
 	if (transfer.flags & ZEND_FIBER_TRANSFER_FLAG_ERROR) {
 		EG(exception) = Z_OBJ(transfer.value);
@@ -659,13 +664,6 @@ ZEND_METHOD(Fiber, suspend)
 
 	zend_fiber_transfer transfer = zend_fiber_suspend(fiber, value);
 
-	if (fiber->flags & ZEND_FIBER_FLAG_DESTROYED) {
-		// This occurs when the fiber is GC'ed while suspended.
-		zval_ptr_dtor(&transfer.value);
-		zend_throw_graceful_exit();
-		RETURN_THROWS();
-	}
-
 	zend_fiber_delegate_transfer_result(&transfer, INTERNAL_FUNCTION_PARAM_PASSTHRU);
 }