pythonGH-94597 add asyncio.EventLoop

graingert · Oct 11, 2023 · d2f7090 · d2f7090
1 parent eb50cd3
commit d2f7090
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diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst
@@ -1723,6 +1723,14 @@ on Unix and :class:`ProactorEventLoop` on Windows.
       `MSDN documentation on I/O Completion Ports
       <https://docs.microsoft.com/en-ca/windows/desktop/FileIO/i-o-completion-ports>`_.
 
+.. class:: EventLoop
+
+    Uses the most effiecient available event loop for the given
+    platform.
+
+   .. versionadded:: 3.13
+
+   .. availability:: Unix, Windows.
 
 .. class:: AbstractEventLoop
 

diff --git 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
@@ -1510,3 +1510,4 @@ 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
@@ -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
@@ -272,6 +272,16 @@ 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):
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1510,3 +1510,4 @@ def set_child_watcher(self, watcher):

		SelectorEventLoop = _UnixSelectorEventLoop
		DefaultEventLoopPolicy = _UnixDefaultEventLoopPolicy
		EventLoop = SelectorEventLoop
Original file line number	Diff line number	Diff line change
Expand Up		@@ -894,3 +894,4 @@ class WindowsProactorEventLoopPolicy(events.BaseDefaultEventLoopPolicy):


		DefaultEventLoopPolicy = WindowsProactorEventLoopPolicy
		EventLoop = ProactorEventLoop