bpo-30048: asyncio: fix Task.cancel() was ignored. (GH-1546)
when there are no more `await` or `yield (from)` before return in coroutine,
cancel was ignored.
example:
async def coro():
asyncio.Task.current_task().cancel()
return 42
...
res = await coro() # should raise CancelledError
(cherry picked from commit 991adca012f5e106c2d4040ce619c696ba6f9c46)diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
index a77ff96..75327fa 100644
--- a/Modules/_asynciomodule.c
+++ b/Modules/_asynciomodule.c
@@ -1984,6 +1984,16 @@
if (_PyGen_FetchStopIterationValue(&o) == 0) {
/* The error is StopIteration and that means that
the underlying coroutine has resolved */
+ if (task->task_must_cancel) {
+ // Task is cancelled right before coro stops.
+ Py_DECREF(o);
+ task->task_must_cancel = 0;
+ et = asyncio_CancelledError;
+ Py_INCREF(et);
+ ev = NULL;
+ tb = NULL;
+ goto set_exception;
+ }
PyObject *res = future_set_result((FutureObj*)task, o);
Py_DECREF(o);
if (res == NULL) {
@@ -2001,6 +2011,8 @@
/* Some other exception; pop it and call Task.set_exception() */
PyErr_Fetch(&et, &ev, &tb);
+
+set_exception:
assert(et);
if (!ev || !PyObject_TypeCheck(ev, (PyTypeObject *) et)) {
PyErr_NormalizeException(&et, &ev, &tb);