https://github.com/python/cpython/commit/b205580c37b765f212b961c3f1119ba74f5a7099 commit: b205580c37b765f212b961c3f1119ba74f5a7099 branch: 3.13 author: Bhuvansh <[email protected]> committer: serhiy-storchaka <[email protected]> date: 2026-08-20T19:46:38+03:00 summary:
[3.13] gh-153005: Use a monotonic clock for concurrent.interpreters Queue timeouts (GH-154156) (GH-156019) Queue.get() and Queue.put() computed their timeout deadline from time.time(), the wall clock. If the system clock was stepped (NTP, a manual change) while a call was blocked, the timeout could over- or under-wait. queue.Queue uses time.monotonic() for the same reason. Compute the deadline and check it against time.monotonic() instead. (cherry picked from commit b94b9c8886a987a324a677b5fda5bef27f15cb14) Co-authored-by: Vyron Vasileiadis <[email protected]> files: A Misc/NEWS.d/next/Library/2026-07-19-17-45-00.gh-issue-153005.F6WH92.rst M Lib/test/support/interpreters/queues.py M Lib/test/test_interpreters/test_queues.py diff --git a/Lib/test/support/interpreters/queues.py b/Lib/test/support/interpreters/queues.py index deb8e8613af731..c5b1fc9dd31bbf 100644 --- a/Lib/test/support/interpreters/queues.py +++ b/Lib/test/support/interpreters/queues.py @@ -230,14 +230,14 @@ def put(self, obj, timeout=None, *, timeout = int(timeout) if timeout < 0: raise ValueError(f'timeout value must be non-negative') - end = time.time() + timeout + end = time.monotonic() + timeout if fmt is _PICKLED: obj = pickle.dumps(obj) while True: try: _queues.put(self._id, obj, fmt, unboundop) except QueueFull as exc: - if timeout is not None and time.time() >= end: + if timeout is not None and time.monotonic() >= end: raise # re-raise time.sleep(_delay) else: @@ -271,12 +271,12 @@ def get(self, timeout=None, *, timeout = int(timeout) if timeout < 0: raise ValueError(f'timeout value must be non-negative') - end = time.time() + timeout + end = time.monotonic() + timeout while True: try: obj, fmt, unboundop = _queues.get(self._id) except QueueEmpty as exc: - if timeout is not None and time.time() >= end: + if timeout is not None and time.monotonic() >= end: raise # re-raise time.sleep(_delay) else: diff --git a/Lib/test/test_interpreters/test_queues.py b/Lib/test/test_interpreters/test_queues.py index 7858c4e602ce2b..f05ef46f761b57 100644 --- a/Lib/test/test_interpreters/test_queues.py +++ b/Lib/test/test_interpreters/test_queues.py @@ -2,8 +2,9 @@ import pickle import threading from textwrap import dedent -import unittest import time +import unittest +from unittest import mock from test.support import import_helper, Py_DEBUG # Raise SkipTest if subinterpreters not supported. @@ -383,6 +384,19 @@ def test_get_timeout(self): with self.assertRaises(queues.QueueEmpty): queue.get(timeout=0.1) + def test_timeout_uses_monotonic_clock(self): + # gh-153005: the deadline must be computed from the monotonic clock, + # since the wall clock can be adjusted while the call is blocked. + queue = queues.create(1) + with mock.patch.object(queues, 'time', wraps=time) as fake_time: + with self.assertRaises(queues.QueueEmpty): + queue.get(timeout=0) + queue.put(None) + with self.assertRaises(queues.QueueFull): + queue.put(None, timeout=0) + fake_time.monotonic.assert_called() + fake_time.time.assert_not_called() + def test_get_nowait(self): queue = queues.create() with self.assertRaises(queues.QueueEmpty): diff --git a/Misc/NEWS.d/next/Library/2026-07-19-17-45-00.gh-issue-153005.F6WH92.rst b/Misc/NEWS.d/next/Library/2026-07-19-17-45-00.gh-issue-153005.F6WH92.rst new file mode 100644 index 00000000000000..7f3d10b3072ef9 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-07-19-17-45-00.gh-issue-153005.F6WH92.rst @@ -0,0 +1,4 @@ +:meth:`!concurrent.interpreters.Queue.get` and +:meth:`!concurrent.interpreters.Queue.put` now compute their ``timeout`` +deadline from :func:`time.monotonic` instead of the wall clock, so adjusting +the system clock during the call no longer makes them over- or under-wait. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
