Description

smontanaro

opened on Nov 13, 2014

Issue body actions

BPO	22867
Nosy	@smontanaro, @vadmium

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2014-11-13.20:52:37.164>
labels = ['docs']
title = 'document behavior of calling atexit.register() while atexit._run_exitfuncs is running'
updated_at = <Date 2015-07-21.07:43:20.900>
user = 'https://github.com/smontanaro'

bugs.python.org fields:

activity = <Date 2015-07-21.07:43:20.900>
actor = 'ethan.furman'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2014-11-13.20:52:37.164>
creator = 'skip.montanaro'
dependencies = []
files = []
hgrepos = []
issue_num = 22867
keywords = []
message_count = 2.0
messages = ['231135', '231354']
nosy_count = 3.0
nosy_names = ['skip.montanaro', 'docs@python', 'martin.panter']
pr_nums = []
priority = 'low'
resolution = None
stage = None
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue22867'
versions = []

Linked PRs

• gh-67056: document that registering/unregistering an atexit func from within an atexit func is undefined #104473
• [3.11] gh-67056: document that registering/unregistering an atexit func from within an atexit func is undefined (GH-104473) #104500

Activity

1. smontanaro commented on Nov 13, 2014

   

   smontanaro

   on Nov 13, 2014

   ContributorAuthor

   More actions

   A discussion on comp.lang.python about prettying up the "if __name__ == 'main__'" idiom led to a suggestion that a decorator could simple register the main function using atexit.register. That looks like it will work, but leaves open the possibility that while main() is running via atexit._run_exitfuncs, other exit functions might be registered.

   As currently defined (at least in the Python version with 2.7), I think everything will work fine. Still, the behavior of adding new exit functions during exit is not defined. Would be kind of nice if this behavior was blessed, and then mentioned in the documentation.
2. smontanaro

   assigned

   docspython

   on Nov 13, 2014
3. smontanaro

   added

   docsDocumentation in the Doc dirDocumentation in the Doc dir

   on Nov 13, 2014
4. ethanfurman commented on Nov 19, 2014

   

   ethanfurman

   on Nov 19, 2014

   Member

   More actions

   From a post by Ian Kelly (https://mail.python.org/pipermail/python-list/2014-November/681073.html)
   --------------------------------------------------------------
   In fact it seems the behavior does differ between Python 2.7 and Python 3.4:

   $ cat testatexit.py
   import atexit
   
   @atexit.register
   def main():
     atexit.register(goodbye)
   
   @atexit.register
   def goodbye():
     print("Goodbye")
   $ python2 testatexit.py
   Goodbye
   Goodbye
   $ python3 testatexit.py
   Goodbye
5. ezio-melotti

   transferred this issue fromon Apr 10, 2022
6. iritkatriel commented on May 13, 2023

   

   iritkatriel

   on May 13, 2023

   Member

   More actions

   The atexit functions are invoked in LIFO order, so I think it's not a good idea to add more after the first one started running. We don't currently forbid, it and I wouldn't argue in favour of doing so, but we shouldn't encourage it.
7. smontanaro commented on May 13, 2023

   

   smontanaro

   on May 13, 2023

   ContributorAuthor

   More actions

   This has been idle for "awhile." Should we just put our heads together and decide how best to document this behavior?

   Reacted by Irit Katriel
8. iritkatriel commented on May 13, 2023

   

   iritkatriel

   on May 13, 2023

   Member

   More actions

   I'm not sure what the behaviour is. Or rather, what behaviour we want to commit to.
9. smontanaro commented on May 14, 2023

   

   smontanaro

   on May 14, 2023

   ContributorAuthor

   More actions

   I'm not sure that committing to any particular behavior is the right thing to do without some more discussion. Maybe just warn that calling atexit.register after _PyAtExit_Call has been invoked is undefined. There's no mention of that corner case in the 3.11 or 3.12 documentation as it stands.

   Reacted by Irit Katriel
10. iritkatriel

    added 2 commits that reference this issue on May 14, 2023

    pythongh-67056: document that registering/unregistering an atexit fun…

    d3127cd

    Revert "pythongh-67056: document that registering/unregistering an at…

    e23c17b
11. iritkatriel

    closed this as completedin #104473on May 15, 2023
12. iritkatriel

    added a commit that references this issue on May 15, 2023

    gh-67056: document that registering/unregistering an atexit func from…

    b15a1a6
13. miss-islington

    added a commit that references this issue on May 15, 2023

    pythongh-67056: document that registering/unregistering an atexit fun…

    6ade9ea
14. iritkatriel

    added a commit that references this issue on May 15, 2023

    [3.11] gh-67056: document that registering/unregistering an atexit fu…

    a712c5f
15. carljm

    added 2 commits that reference this issue on May 15, 2023

    Merge branch 'main' into supermon

    343867a

    Merge branch 'main' into cached_property_docs

    452d9f5

Issue actions