New submission from Sam Gross <colesb...@gmail.com>:
The test_queue suite has a race condition that can lead to test failures in test_many_threads, test_many_threads_nonblock, and test_many_threads_timeout. Consumers are signaled to exit by a sentinel value (None). The sentinel values are at the end of the input list, but that doesn't mean they are necessarily enqueued at the end of the inter-thread queue when there are multiple "feeder" threads. In particular, a feeder thread may be delayed in enqueueing a non-sentinel value. The other feeder threads may finish popping and enqueueing the remaining values including all the sentinels, leading to the delayed non-sentinel value arriving AFTER all the sentinels. The "consumer" threads exit before processing all the values leading to the assertion error in run_threads() in test_queue.py: self.assertTrue(q.empty()) I will attach a patch that adds a delay in feed() to make the race condition occur more frequently so that the issue is easier to reproduce. ---------- components: Tests messages: 406498 nosy: colesbury priority: normal severity: normal status: open title: Race condition in test_queue can lead to test failures type: behavior versions: Python 3.10, Python 3.11, Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue45835> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
