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| author | Itamar Ostricher <itamarost@gmail.com> | 2023-05-05 16:44:03 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-05-05 16:44:03 -0700 |
| commit | 52d8f36e8c9f6048367d7bdfede3698e3f5f70d0 (patch) | |
| tree | 69e07fa1186a2886ba38e9c75e765511490386e5 | |
| parent | f3e7eb48f86057919c347f56dabf417acfd55845 (diff) | |
| download | cpython-git-52d8f36e8c9f6048367d7bdfede3698e3f5f70d0.tar.gz | |
gh-104144: Skip scheduling a done callback if a TaskGroup task completes eagerly (#104140)
Co-authored-by: Carl Meyer <carl@oddbird.net>
| -rw-r--r-- | Lib/asyncio/taskgroups.py | 10 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2023-05-03-16-51-53.gh-issue-104144.653Q0P.rst | 1 |
2 files changed, 9 insertions, 2 deletions
diff --git a/Lib/asyncio/taskgroups.py b/Lib/asyncio/taskgroups.py index 0fdea3697e..06b2e0db86 100644 --- a/Lib/asyncio/taskgroups.py +++ b/Lib/asyncio/taskgroups.py @@ -164,8 +164,14 @@ class TaskGroup: 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 0000000000..59870de3e0 --- /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. |