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Deprecate thread debugging PYTHONTHREADDEBUG=1 #88750
Description
| BPO | 44584 |
|---|---|
| Nosy | @vstinner, @miss-islington |
| PRs |
Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.
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GitHub fields:
assignee = None
closed_at = <Date 2021-08-06.12:14:30.875>
created_at = <Date 2021-07-08.09:23:08.980>
labels = ['interpreter-core', '3.10', '3.11']
title = 'Deprecate thread debugging PYTHONTHREADDEBUG=1'
updated_at = <Date 2021-08-06.12:14:30.874>
user = 'https://github.com/vstinner'bugs.python.org fields:
activity = <Date 2021-08-06.12:14:30.874>
actor = 'vstinner'
assignee = 'none'
closed = True
closed_date = <Date 2021-08-06.12:14:30.875>
closer = 'vstinner'
components = ['Interpreter Core']
creation = <Date 2021-07-08.09:23:08.980>
creator = 'vstinner'
dependencies = []
files = []
hgrepos = []
issue_num = 44584
keywords = ['patch']
message_count = 5.0
messages = ['397130', '397131', '399071', '399074', '399077']
nosy_count = 2.0
nosy_names = ['vstinner', 'miss-islington']
pr_nums = ['27065', '27624']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue44584'
versions = ['Python 3.10', 'Python 3.11']
Activity
vstinner commentedon Jul 8, 2021
Copy of my email to python-dev:
https://mail.python.org/archives/list/python-dev@python.org/thread/NMLGCDRUKLZSTK4UICJTKR54WRXU2ZGJ/
Hi,
Does anyone use threading debug PYTHONTHREADDEBUG=1 env var on a
Python debug build? If not, can I just remove it?
--
To fix a race condition at thread exit on Linux using the glibc, I
removed calls to pthread_exit() (PyThread_exit_thread()) in the
_thread module:
https://bugs.python.org/issue44434
A side effect of this change is the removal of the
"PyThread_exit_thread called" threading debug log when using
PYTHONTHREADDEBUG=1 environment variable.
I never used PYTHONTHREADDEBUG. I just tried it and it produces tons
of output in stdout about locks. It looks basically useless because it
produces way too many logs, and it pollutes stdout (ex: most Python
tests fail when it's enabled).
This debug mode requires to build Python in debug mode (./configure
--with-pydebug):
https://docs.python.org/dev/using/configure.html#python-debug-build
IMO there are enough external debugging tools to debug threading
issues. Python no longer has to come with its built-in logs.
I propose to deprecate the feature in Python 3.11 and remove it in 2
releases (Python 3.13).
Victor
vstinner commentedon Jul 8, 2021
I never ever used PYTHONTHREADDEBUG=1. I just tried:
---
======================================================================
FAIL: test_changing_sys_stderr_and_removing_reference (test.test_sys.SizeofTest)
----------------------------------------------------------------------
This debug mode produces so many logs that it looks basically useless :-(
See also discussion at: #24241
vstinner commentedon Aug 6, 2021
New changeset 4d77691 by Victor Stinner in branch 'main':
bpo-44584: Deprecate PYTHONTHREADDEBUG env var (GH-27065)
4d77691
miss-islington commentedon Aug 6, 2021
New changeset a11158e by Miss Islington (bot) in branch '3.10':
bpo-44584: Deprecate PYTHONTHREADDEBUG env var (GH-27065)
a11158e
vstinner commentedon Aug 6, 2021
PYTHONTHREADDEBUG is now deprecated in Python 3.10, and planned for removal in 3.12.
If someone finds it useful, we can reconsider to keep the feature, but maybe redirect the output to stderr rather than stdout.
pythongh-88750: Remove the PYTHONTHREADDEBUG env var support.
gh-88750: Remove the PYTHONTHREADDEBUG env var support. (#92509)
gh-88750: On Windows, PyThread_acquire_lock() no longer checks for NU…