diff --git a/Lib/asyncio/unix_events.py b/Lib/asyncio/unix_events.py index 96e6d73a759794..f88628858c8622 100644 --- a/Lib/asyncio/unix_events.py +++ b/Lib/asyncio/unix_events.py @@ -1423,6 +1423,17 @@ def _do_waitpid(self, loop, expected_pid, callback, args): self._threads.pop(expected_pid) +def can_use_pidfd(): + if not hasattr(os, 'pidfd_open'): + return False + try: + pid = os.getpid() + os.close(os.pidfd_open(pid, 0)) + except OSError: + # blocked by security policy like SECCOMP + return False + return True + class _UnixDefaultEventLoopPolicy(events.BaseDefaultEventLoopPolicy): """UNIX event loop policy with a watcher for child processes.""" @@ -1435,7 +1446,10 @@ def __init__(self): def _init_watcher(self): with events._lock: if self._watcher is None: # pragma: no branch - self._watcher = ThreadedChildWatcher() + if can_use_pidfd(): + self._watcher = PidfdChildWatcher() + else: + self._watcher = ThreadedChildWatcher() if threading.current_thread() is threading.main_thread(): self._watcher.attach_loop(self._local._loop) diff --git a/Lib/test/test_asyncio/test_unix_events.py b/Lib/test/test_asyncio/test_unix_events.py index 5bad21ecbae4af..03fb5e649d8e97 100644 --- a/Lib/test/test_asyncio/test_unix_events.py +++ b/Lib/test/test_asyncio/test_unix_events.py @@ -1702,7 +1702,8 @@ def create_policy(self): def test_get_default_child_watcher(self): policy = self.create_policy() self.assertIsNone(policy._watcher) - + unix_events.can_use_pidfd = mock.Mock() + unix_events.can_use_pidfd.return_value = False watcher = policy.get_child_watcher() self.assertIsInstance(watcher, asyncio.ThreadedChildWatcher) @@ -1710,6 +1711,17 @@ def test_get_default_child_watcher(self): self.assertIs(watcher, policy.get_child_watcher()) + policy = self.create_policy() + self.assertIsNone(policy._watcher) + unix_events.can_use_pidfd = mock.Mock() + unix_events.can_use_pidfd.return_value = True + watcher = policy.get_child_watcher() + self.assertIsInstance(watcher, asyncio.PidfdChildWatcher) + + self.assertIs(policy._watcher, watcher) + + self.assertIs(watcher, policy.get_child_watcher()) + def test_get_child_watcher_after_set(self): policy = self.create_policy() watcher = asyncio.FastChildWatcher() diff --git a/Misc/NEWS.d/next/Library/2022-10-07-09-52-37.gh-issue-98023.aliEcl.rst b/Misc/NEWS.d/next/Library/2022-10-07-09-52-37.gh-issue-98023.aliEcl.rst new file mode 100644 index 00000000000000..1bfd68d4ac7ca0 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2022-10-07-09-52-37.gh-issue-98023.aliEcl.rst @@ -0,0 +1 @@ +Change default child watcher to :class:`~asyncio.PidfdChildWatcher` on Linux systems which supports it. Patch by Kumar Aditya.