diff options
| -rw-r--r-- | Lib/asyncio/runners.py | 8 | ||||
| -rw-r--r-- | Lib/test/test_asyncio/test_runners.py | 14 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2022-08-11-18-52-17.gh-issue-95899._Bi4uG.rst | 1 |
3 files changed, 20 insertions, 3 deletions
diff --git a/Lib/asyncio/runners.py b/Lib/asyncio/runners.py index a8b74d5..840b133 100644 --- a/Lib/asyncio/runners.py +++ b/Lib/asyncio/runners.py @@ -114,8 +114,6 @@ class Runner: self._interrupt_count = 0 try: - if self._set_event_loop: - events.set_event_loop(self._loop) return self._loop.run_until_complete(task) except exceptions.CancelledError: if self._interrupt_count > 0: @@ -136,7 +134,11 @@ class Runner: return if self._loop_factory is None: self._loop = events.new_event_loop() - self._set_event_loop = True + if not self._set_event_loop: + # Call set_event_loop only once to avoid calling + # attach_loop multiple times on child watchers + events.set_event_loop(self._loop) + self._set_event_loop = True else: self._loop = self._loop_factory() if self._debug is not None: diff --git a/Lib/test/test_asyncio/test_runners.py b/Lib/test/test_asyncio/test_runners.py index d61d073a..1308b7e 100644 --- a/Lib/test/test_asyncio/test_runners.py +++ b/Lib/test/test_asyncio/test_runners.py @@ -455,6 +455,20 @@ class RunnerTests(BaseTest): ): runner.run(coro()) + def test_set_event_loop_called_once(self): + # See https://github.com/python/cpython/issues/95736 + async def coro(): + pass + + policy = asyncio.get_event_loop_policy() + policy.set_event_loop = mock.Mock() + runner = asyncio.Runner() + runner.run(coro()) + runner.run(coro()) + + self.assertEqual(1, policy.set_event_loop.call_count) + runner.close() + if __name__ == '__main__': unittest.main() diff --git a/Misc/NEWS.d/next/Library/2022-08-11-18-52-17.gh-issue-95899._Bi4uG.rst b/Misc/NEWS.d/next/Library/2022-08-11-18-52-17.gh-issue-95899._Bi4uG.rst new file mode 100644 index 0000000..d2386cf --- /dev/null +++ b/Misc/NEWS.d/next/Library/2022-08-11-18-52-17.gh-issue-95899._Bi4uG.rst @@ -0,0 +1 @@ +Fix :class:`asyncio.Runner` to call :func:`asyncio.set_event_loop` only once to avoid calling :meth:`~asyncio.AbstractChildWatcher.attach_loop` multiple times on child watchers. Patch by Kumar Aditya. |