[issue42097] Python 3.7.9 logging/threading/fork hang

[Andrew de Quincey]

New submission from Andrew de Quincey <Adq at tvsquared.com>:

We've been having some mysterious hangs in our threaded code. Debugging with GDB shows it ends up deadlocking during logging inside logging._acquireLock()

I googled and found someone else with the same issue: https://stackoverflow.com/questions/62059975/python-multiprocessing-logging-hangs

I'm able to replicate this on python 3.7.9 on two entirely separate machines (one ubuntu, one arch linux), though I had to bump up the number of iterations to 1000.

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components: Library (Lib)
files: test.py
messages: 379132
nosy: Adq
priority: normal
severity: normal
status: open
title: Python 3.7.9 logging/threading/fork hang
type: behavior
versions: Python 3.7
Added file: https://bugs.python.org/file49531/test.py

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<https://bugs.python.org/issue42097>
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