https://github.com/python/cpython/commit/b0c9fc37dd0ed60456313600e6a01478308f195e
commit: b0c9fc37dd0ed60456313600e6a01478308f195e
branch: main
author: Timofei Ivankov <[email protected]>
committer: kumaraditya303 <[email protected]>
date: 2026-08-29T14:09:07+05:30
summary:
gh-156523: Fix asyncio.as_completed() not recording the awaiting task (#156527)
files:
A Misc/NEWS.d/next/Library/2026-08-28-18-10-25.gh-issue-156523.llJqo9.rst
M Lib/asyncio/tasks.py
M Lib/test/test_asyncio/test_graph.py
diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index 498eec3f31b292b..f432cf0afa895a2 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -562,9 +562,11 @@ def __init__(self, aws, timeout):
self._timeout_handle = None
loop = events.get_event_loop()
+ self._cur_task = current_task()
todo = {ensure_future(aw, loop=loop) for aw in set(aws)}
for f in todo:
f.add_done_callback(self._handle_completion)
+ futures.future_add_to_awaited_by(f, self._cur_task)
if todo and timeout is not None:
self._timeout_handle = (
loop.call_later(timeout, self._handle_timeout)
@@ -595,6 +597,7 @@ def __next__(self):
def _handle_timeout(self):
for f in self._todo:
f.remove_done_callback(self._handle_completion)
+ futures.future_discard_from_awaited_by(f, self._cur_task)
self._done.put_nowait(None) # Sentinel for _wait_for_one().
self._todo.clear() # Can't do todo.remove(f) in the loop.
@@ -602,6 +605,7 @@ def _handle_completion(self, f):
if not self._todo:
return # _handle_timeout() was here first.
self._todo.remove(f)
+ futures.future_discard_from_awaited_by(f, self._cur_task)
self._done.put_nowait(f)
if not self._todo and self._timeout_handle is not None:
self._timeout_handle.cancel()
diff --git a/Lib/test/test_asyncio/test_graph.py
b/Lib/test/test_asyncio/test_graph.py
index 928b618fe5c55b7..220c0179f27bf3b 100644
--- a/Lib/test/test_asyncio/test_graph.py
+++ b/Lib/test/test_asyncio/test_graph.py
@@ -298,6 +298,68 @@ async def main(t1, t2):
]
])
+ async def test_stack_as_completed(self):
+ # gh-156523: as_completed() must record the awaiting task
+ stack_for_inner = None
+
+ async def inner():
+ await asyncio.sleep(0)
+ nonlocal stack_for_inner
+ stack_for_inner = capture_test_stack()
+
+ async def main(t):
+ for f in asyncio.as_completed([t]):
+ await f
+
+ t = asyncio.create_task(inner(), name='inner')
+ await main(t)
+ self.assertFalse(t._asyncio_awaited_by)
+
+ self.assertEqual(stack_for_inner[0], [
+ 'T<inner>',
+ ['s capture_test_stack', 'a inner'],
+ [
+ ['T<anon>',
+ ['a get', 'a _wait_for_one', 'a main',
+ 'a test_stack_as_completed'],
+ []
+ ]
+ ]
+ ])
+
+ async def test_stack_as_completed_timeout(self):
+ # gh-156523: the awaiting task must be dropped when as_completed()
times out
+ stack_for_inner = None
+
+ async def inner():
+ nonlocal stack_for_inner
+ stack_for_inner = capture_test_stack()
+ await asyncio.sleep(3600)
+
+ async def main(t):
+ with self.assertRaises(TimeoutError):
+ for f in asyncio.as_completed([t], timeout=0.01):
+ await f
+
+ t = asyncio.create_task(inner(), name='inner')
+ await main(t)
+ self.assertFalse(t._asyncio_awaited_by)
+ t.cancel()
+ with self.assertRaises(asyncio.CancelledError):
+ await t
+
+ self.assertEqual(stack_for_inner[0], [
+ 'T<inner>',
+ ['s capture_test_stack', 'a inner'],
+ [
+ ['T<anon>',
+ ['a get', 'a _wait_for_one', 'a main',
+ 'a test_stack_as_completed_timeout'],
+ []
+ ]
+ ]
+ ])
+
async def test_stack_task(self):
stack_for_inner = None
diff --git
a/Misc/NEWS.d/next/Library/2026-08-28-18-10-25.gh-issue-156523.llJqo9.rst
b/Misc/NEWS.d/next/Library/2026-08-28-18-10-25.gh-issue-156523.llJqo9.rst
new file mode 100644
index 000000000000000..c1c95d76c0d23bb
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-08-28-18-10-25.gh-issue-156523.llJqo9.rst
@@ -0,0 +1,2 @@
+Fix :func:`asyncio.as_completed` not recording the awaiting task in the call
+graph.
_______________________________________________
Python-checkins mailing list -- [email protected]
To unsubscribe send an email to [email protected]
https://mail.python.org/mailman3//lists/python-checkins.python.org
Member address: [email protected]
