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Created on 2020-03-04 13:20 by aclover, last changed 2022-04-11 14:59 by admin. This issue is now closed.
| Pull Requests | |||
|---|---|---|---|
| URL | Status | Linked | Edit |
| PR 18780 | merged | aclover, 2020-03-04 16:40 | |
| PR 18945 | merged | miss-islington, 2020-03-11 23:39 | |
| PR 18959 | merged | aclover, 2020-03-12 14:08 | |
| Messages (7) | |||
|---|---|---|---|
| msg363346 - (view) | Author: And Clover (aclover) * | Date: 2020-03-04 13:20 | |
Since bpo-15038, waiting to acquire locks/events/etc from _thread/threading on Windows can fail to return long past the requested timeout. Cause: https://github.com/python/cpython/blob/3.8/Python/thread_nt.h#L85 using 32-bit GetTickCount/DWORD, which will overflow at around 49.7 days of uptime. If the WaitForSingleObjectEx call in PyCOND_TIMEDWAIT returns later than the 'target' time, and the tick count overflows in that gap, 'milliseconds' will become very large (up to another 49.7 days) and the next PyCOND_TIMEDWAIT will be stuck for a long time. Where we've seen it is where it's most likely to happen: when the machine is hibernated during the WaitForSingleObjectEx call. I believe the TickCount continues to increase during hibernation so there is a much bigger gap between 'target' and 'now' for the overflow to happen in. Simplest fix is probably to switch to GetTickCount64/ULONGLONG. We should be able to get away with using this now we no longer support WinXP. |
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| msg363347 - (view) | Author: STINNER Victor (vstinner) *  |
Date: 2020-03-04 13:22 | |
time.monotonic() is now always implemented with GetTickCount64() on Windows. Previously, there was a fallback on GetTickCount() when GetTickCount64() was not available. GetTickCount() call has been removed when we dropped support for old Windows versions. Do you want to work on a fix? (PR) |
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| msg363351 - (view) | Author: And Clover (aclover) * | Date: 2020-03-04 14:23 | |
Yep, should be straightforward to fix (though not to test, as fifty-day test cases tend to be frowned upon...) |
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| msg363986 - (view) | Author: STINNER Victor (vstinner) * |
Date: 2020-03-11 23:39 | |
New changeset 64838ce7172c7a92183b39b22504b433a33a884d by bobince in branch 'master': bpo-39847: EnterNonRecursiveMutex() uses GetTickCount64() (GH-18780) https://github.com/python/cpython/commit/64838ce7172c7a92183b39b22504b433a33a884d |
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| msg363989 - (view) | Author: miss-islington (miss-islington) | Date: 2020-03-11 23:57 | |
New changeset 60b1b5ac56fe6099a3d358dc9d6cd6ec72fce2d8 by Miss Islington (bot) in branch '3.8': bpo-39847: EnterNonRecursiveMutex() uses GetTickCount64() (GH-18780) https://github.com/python/cpython/commit/60b1b5ac56fe6099a3d358dc9d6cd6ec72fce2d8 |
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| msg364022 - (view) | Author: miss-islington (miss-islington) | Date: 2020-03-12 14:28 | |
New changeset feaf0c37891dfe8f0f3e643c3711af3af23bf805 by bobince in branch '3.7': [3.7] bpo-39847: EnterNonRecursiveMutex() uses GetTickCount64() (GH-18780) (GH-18959) https://github.com/python/cpython/commit/feaf0c37891dfe8f0f3e643c3711af3af23bf805 |
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| msg364023 - (view) | Author: STINNER Victor (vstinner) * |
Date: 2020-03-12 14:29 | |
Thanks, it's now fixed in 3.7, 3.8 and master branches. Python 3.5 and 3.6 don't get bugfixes anymore: https://devguide.python.org/#status-of-python-branches |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2022-04-11 14:59:27 | admin | set | github: 84028 |
| 2020-03-12 14:29:14 | vstinner | set | status: open -> closed versions: + Python 3.9, - Python 3.5, Python 3.6 messages: + msg364023 resolution: fixed stage: patch review -> resolved |
| 2020-03-12 14:28:38 | miss-islington | set | messages: + msg364022 |
| 2020-03-12 14:08:14 | aclover | set | pull_requests: + pull_request18309 |
| 2020-03-11 23:57:21 | miss-islington | set | messages: + msg363989 |
| 2020-03-11 23:39:52 | miss-islington | set | nosy:
+ miss-islington pull_requests: + pull_request18299 |
| 2020-03-11 23:39:07 | vstinner | set | messages: + msg363986 |
| 2020-03-04 16:40:29 | aclover | set | keywords:
+ patch stage: patch review pull_requests: + pull_request18136 |
| 2020-03-04 14:23:57 | aclover | set | messages: + msg363351 |
| 2020-03-04 14:01:31 | sparrowt | set | nosy:
+ sparrowt |
| 2020-03-04 13:38:51 | Day Barr | set | nosy:
+ Day Barr |
| 2020-03-04 13:23:12 | vstinner | set | title: EnterNonRecursiveMutex on win32 can hang for 49.7 days -> EnterNonRecursiveMutex on win32 can hang for 49.7 days: use GetTickCount64() rather than GetTickCount() |
| 2020-03-04 13:22:57 | vstinner | set | nosy:
+ vstinner messages: + msg363347 |
| 2020-03-04 13:20:26 | aclover | create | |