[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

miss-islington added the comment: New changeset ceba0648d70524ec4ebb7a46d5d1162d4938c7ba by Miss Islington (bot) in branch '3.8': bpo-38501: Add a warning section to multiprocessing.Pool docs about resource managing (GH-19466)

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

miss-islington added the comment: New changeset 2e49b5254aa0888dd21a7929be14b6cfe03d56ef by Miss Islington (bot) in branch '3.7': bpo-38501: Add a warning section to multiprocessing.Pool docs about resource managing (GH-19466)

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Pablo Galindo Salgado added the comment: New changeset 7ec43a73092d43c6c95e7dd2669f49d54b57966f by Pablo Galindo in branch 'master': bpo-38501: Add a warning section to multiprocessing.Pool docs about resource managing (GH-19466)

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Change by miss-islington : -- pull_requests: +18823 pull_request: https://github.com/python/cpython/pull/19468 ___ Python tracker ___

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Change by miss-islington : -- nosy: +miss-islington nosy_count: 7.0 -> 8.0 pull_requests: +18822 pull_request: https://github.com/python/cpython/pull/19467 ___ Python tracker

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Change by Pablo Galindo Salgado : -- pull_requests: +18821 pull_request: https://github.com/python/cpython/pull/19466 ___ Python tracker ___

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Pablo Galindo Salgado added the comment: > One potential reason would be that the consequences of bad resource > management in this case are different than in the open() case, i.e., here the > interpreter hangs -- or Travis runs for your repo (SciPy) get stuck with > over-50-minute errors,

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Eric Larson added the comment: > Why? This is a resource like any other and it requires proper resource > management. Would you also put a big warning on "open()" stating that opening > a file requires either using a context manager or ensure a manual close()? One potential reason would be

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Pablo Galindo Salgado added the comment: > If that's out of contract, perhaps there should probably a big, visible > warning at the top of the multiprocessning docs stating that creating one of > these objects requires either using a context manager or ensuring manual > `.close()`ing? Why?

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Eric Larson added the comment: If that's out of contract, perhaps there should probably a big, visible warning at the top of the multiprocessning docs stating that creating one of these objects requires either using a context manager or ensuring manual `.close()`ing? 1. It either used to

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Pablo Galindo Salgado added the comment: > Not sure if there are any special considerations for Windows here. It should not be anything windows specific here. Also notice that although "it works", the reproducer in https://bugs.python.org/issue38501#msg354813 is out of contract because is

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Stefano Rivera added the comment: On Linux, the reproducer in https://bugs.python.org/issue38501#msg354813 fails on ac10e0c93218627d1a639db0b7b41714c5f6a883^ and passes on ac10e0c93218627d1a639db0b7b41714c5f6a883, which is why I say PR 19009 fixes it. Not sure if there are any special

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Pablo Galindo Salgado added the comment: >Looks like it was fixed by PR 19009 (bpo-39360)). Can we close the issue then? If not, could yo provide a reproducer and also check if the big is fixed on master or 3.8 HEAD? Thanks! -- ___ Python tracker

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Stefano Rivera added the comment: Looks like it was fixed by PR 19009 (bpo-39360)). -- ___ Python tracker ___ ___ Python-bugs-list

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Change by Pablo Galindo Salgado : -- keywords: +patch nosy: +pablogsal nosy_count: 6.0 -> 7.0 pull_requests: +18808 stage: -> patch review pull_request: https://github.com/python/cpython/pull/11488 ___ Python tracker

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Change by Andrew Nelson : -- nosy: +Andrew Nelson ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Stefano Rivera added the comment: A bisect points at https://github.com/python/cpython/pull/11488 being the change that introduced this hang (bpo-35493) -- nosy: +stefanor ___ Python tracker

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Change by Ralf Gommers : -- nosy: +ralf.gommers ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Change by Caleb Hattingh : -- nosy: +cjrh ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

Paul Silisteanu added the comment: Same issue on Window 10 and macOS Catalina with Python 3.8.0. Here is the error I get on Windows 10: C:\Users\x>py -3.8 Python 3.8.0 (tags/v3.8.0:fa919fd, Oct 14 2019, 19:37:50) [MSC v.1916 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or

[issue38501] multiprocessing.Pool hangs atexit (and garbage collection sometimes)

New submission from Eric Larson : The following code hangs on Python 3.8.0.rc0 on Ubuntu 19.10 when exiting the interpreter: from multiprocessing import Pool class A(object): def __init__(self): self.pool = Pool(processes=2) solver = A() When you eventually do ctrl-C, the