diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst index 04af53b980ff9eb..361e7bb9c8f2fa8 100644 --- a/Doc/library/asyncio-eventloop.rst +++ b/Doc/library/asyncio-eventloop.rst @@ -1686,13 +1686,13 @@ Event Loop Implementations asyncio ships with two different event loop implementations: :class:`SelectorEventLoop` and :class:`ProactorEventLoop`. -By default asyncio is configured to use :class:`SelectorEventLoop` -on Unix and :class:`ProactorEventLoop` on Windows. +By default asyncio is configured to use :class:`EventLoop`. .. class:: SelectorEventLoop - An event loop based on the :mod:`selectors` module. + A subclass of :class:`AbstractEventLoop` based on the + :mod:`selectors` module. Uses the most efficient *selector* available for the given platform. It is also possible to manually configure the @@ -1714,7 +1714,7 @@ on Unix and :class:`ProactorEventLoop` on Windows. .. class:: ProactorEventLoop - An event loop for Windows that uses "I/O Completion Ports" (IOCP). + A subclass of :class:`AbstractEventLoop` for Windows that uses "I/O Completion Ports" (IOCP). .. availability:: Windows. @@ -1723,6 +1723,14 @@ on Unix and :class:`ProactorEventLoop` on Windows. `MSDN documentation on I/O Completion Ports `_. +.. class:: EventLoop + + An alias to the most efficient available subclass of :class:`AbstractEventLoop` for the given + platform. + + It is an alias to :class:`SelectorEventLoop` on Unix and :class:`ProactorEventLoop` on Windows. + + .. versionadded:: 3.13 .. class:: AbstractEventLoop diff --git a/Doc/library/asyncio-runner.rst b/Doc/library/asyncio-runner.rst index b68b2570ef071e1..ec170dfde9e9aa2 100644 --- a/Doc/library/asyncio-runner.rst +++ b/Doc/library/asyncio-runner.rst @@ -42,6 +42,8 @@ Running an asyncio Program This function should be used as a main entry point for asyncio programs, and should ideally only be called once. It is recommended to use *loop_factory* to configure the event loop instead of policies. + Passing :class:`asyncio.EventLoop` allows running asyncio without the + policy system. The executor is given a timeout duration of 5 minutes to shutdown. If the executor hasn't finished within that duration, a warning is diff --git a/Lib/asyncio/unix_events.py b/Lib/asyncio/unix_events.py index 28cef964debd369..65f0923264d14ef 100644 --- a/Lib/asyncio/unix_events.py +++ b/Lib/asyncio/unix_events.py @@ -32,6 +32,7 @@ 'FastChildWatcher', 'PidfdChildWatcher', 'MultiLoopChildWatcher', 'ThreadedChildWatcher', 'DefaultEventLoopPolicy', + 'EventLoop', ) @@ -1510,3 +1511,4 @@ def set_child_watcher(self, watcher): SelectorEventLoop = _UnixSelectorEventLoop DefaultEventLoopPolicy = _UnixDefaultEventLoopPolicy +EventLoop = SelectorEventLoop diff --git a/Lib/asyncio/windows_events.py b/Lib/asyncio/windows_events.py index c9a5fb841cb134b..4a4c4bea8948a0e 100644 --- a/Lib/asyncio/windows_events.py +++ b/Lib/asyncio/windows_events.py @@ -29,7 +29,7 @@ __all__ = ( 'SelectorEventLoop', 'ProactorEventLoop', 'IocpProactor', 'DefaultEventLoopPolicy', 'WindowsSelectorEventLoopPolicy', - 'WindowsProactorEventLoopPolicy', + 'WindowsProactorEventLoopPolicy', 'EventLoop', ) @@ -894,3 +894,4 @@ class WindowsProactorEventLoopPolicy(events.BaseDefaultEventLoopPolicy): DefaultEventLoopPolicy = WindowsProactorEventLoopPolicy +EventLoop = ProactorEventLoop diff --git a/Lib/test/test_asyncio/test_runners.py b/Lib/test/test_asyncio/test_runners.py index 1eb5641914f2a4c..13493d3c806d6a1 100644 --- a/Lib/test/test_asyncio/test_runners.py +++ b/Lib/test/test_asyncio/test_runners.py @@ -3,6 +3,7 @@ import contextvars import re import signal +import sys import threading import unittest from test.test_asyncio import utils as test_utils @@ -272,6 +273,16 @@ async def main(): asyncio.run(main(), loop_factory=factory) factory.assert_called_once_with() + def test_loop_factory_default_event_loop(self): + async def main(): + if sys.platform == "win32": + self.assertIsInstance(asyncio.get_running_loop(), asyncio.ProactorEventLoop) + else: + self.assertIsInstance(asyncio.get_running_loop(), asyncio.SelectorEventLoop) + + + asyncio.run(main(), loop_factory=asyncio.EventLoop) + class RunnerTests(BaseTest): diff --git a/Misc/NEWS.d/next/Library/2023-10-11-15-07-21.gh-issue-94597.NbPC8t.rst b/Misc/NEWS.d/next/Library/2023-10-11-15-07-21.gh-issue-94597.NbPC8t.rst new file mode 100644 index 000000000000000..6874c6111c3f2cd --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-10-11-15-07-21.gh-issue-94597.NbPC8t.rst @@ -0,0 +1 @@ +Added :class:`asyncio.EventLoop` for use with the :func:`asyncio.run` *loop_factory* kwarg to avoid calling the asyncio policy system.