Implement yield state tracking for fiber coroutines and update cancellation logic

Author: EdmondDantes

Zend/zend_async_API.h

@@ -1062,6 +1062,7 @@ struct _zend_coroutine_s {
 #define ZEND_COROUTINE_F_PROTECTED (1u << 13) /* coroutine is protected */
 #define ZEND_COROUTINE_F_MAIN (1u << 14) /* coroutine is a main coroutine */
 #define ZEND_COROUTINE_F_FIBER (1u << 15) /* coroutine is a fiber. extended_data -> fiber structure */
+#define ZEND_COROUTINE_F_YIELD (1u << 16) /* coroutine is YIELD */
 
 #define ZEND_COROUTINE_IS_ZOMBIE(coroutine) \
 	(((coroutine)->event.flags & ZEND_COROUTINE_F_ZOMBIE) != 0)
@@ -1095,6 +1096,12 @@ struct _zend_coroutine_s {
 	(((coroutine)->event.flags & ZEND_COROUTINE_F_FIBER) != 0)
 #define ZEND_COROUTINE_SET_FIBER(coroutine) \
 	((coroutine)->event.flags |= ZEND_COROUTINE_F_FIBER)
+#define ZEND_COROUTINE_IS_YIELD(coroutine) \
+	(((coroutine)->event.flags & ZEND_COROUTINE_F_YIELD) != 0)
+#define ZEND_COROUTINE_SET_YIELD(coroutine) \
+	((coroutine)->event.flags |= ZEND_COROUTINE_F_YIELD)
+#define ZEND_COROUTINE_CLR_YIELD(coroutine) \
+	((coroutine)->event.flags &= ~ZEND_COROUTINE_F_YIELD)
 
 static zend_always_inline zend_string *zend_coroutine_callable_name(
 		const zend_coroutine_t *coroutine)

Zend/zend_fibers.c

@@ -921,6 +921,8 @@ static zend_result zend_fiber_yield(zend_fiber *fiber, zval *value, zval *return
 		return FAILURE;
 	}
 
+	ZEND_COROUTINE_SET_YIELD(fiber->coroutine);
+
 	ZEND_ASYNC_EVENT_CLR_EXCEPTION_HANDLED(&yield_event->base);
 	ZEND_ASYNC_EVENT_SET_ZVAL_RESULT(&yield_event->base);
 	ZEND_ASYNC_CALLBACKS_NOTIFY(&yield_event->base, value, NULL);
@@ -984,6 +986,8 @@ static void zend_fiber_resume_coroutine(zend_fiber *fiber, zval *value, zval *ex
 		return;
 	}
 
+	ZEND_COROUTINE_CLR_YIELD(fiber->coroutine);
+
 	// Wake up the fiber's coroutine
 	if (UNEXPECTED(exception)) {
 		ZEND_ASYNC_EVENT_CLR_ZVAL_RESULT(&fiber->resume_event->base);
@@ -1318,6 +1322,12 @@ static void zend_fiber_object_destroy(zend_object *object)
 
 		ZEND_ASYNC_CANCEL(coroutine, exception, true);
 
+		//
+		// A Fiber shares ownership of a coroutine with the Scheduler. This is important.
+		// When a coroutine is running, it belongs to the Scheduler, and its reference count must be greater than 1.
+		// The purpose of this code is to ensure that when a Fiber is destroyed,
+		// it correctly decrements the coroutine’s reference count without destroying the coroutine itself.
+		//
 		if (ZEND_COROUTINE_IS_STARTED(coroutine)) {
 			ZEND_ASYNC_EVENT_RELEASE(&coroutine->event);
 		}