diff --git a/Lib/asyncio/taskgroups.py b/Lib/asyncio/taskgroups.py index 0fdea3697ece3d..06b2e0db86a1fe 100644 --- a/Lib/asyncio/taskgroups.py +++ b/Lib/asyncio/taskgroups.py @@ -164,8 +164,14 @@ def create_task(self, coro, *, name=None, context=None): else: task = self._loop.create_task(coro, context=context) tasks._set_task_name(task, name) - task.add_done_callback(self._on_task_done) - self._tasks.add(task) + # optimization: Immediately call the done callback if the task is + # already done (e.g. if the coro was able to complete eagerly), + # and skip scheduling a done callback + if task.done(): + self._on_task_done(task) + else: + self._tasks.add(task) + task.add_done_callback(self._on_task_done) return task # Since Python 3.8 Tasks propagate all exceptions correctly, diff --git a/Misc/NEWS.d/next/Library/2023-05-03-16-51-53.gh-issue-104144.653Q0P.rst b/Misc/NEWS.d/next/Library/2023-05-03-16-51-53.gh-issue-104144.653Q0P.rst new file mode 100644 index 00000000000000..59870de3e02edd --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-05-03-16-51-53.gh-issue-104144.653Q0P.rst @@ -0,0 +1 @@ +Optimize :class:`asyncio.TaskGroup` when using :func:`asyncio.eager_task_factory`. Skip scheduling done callbacks when all tasks finish without blocking.