Message 372760 - Python tracker

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In-reply-to
Author	barisione
Recipients	barisione
Date	2020年07月01日.16:05:44
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1593619544.94.0.691494373061.issue41185@roundup.psfhosted.org>

Content
The generation of pickle files in load_grammar in lib2to3/pgen2/driver.py is racy as other processes may end up reading a half-written pickle file. This is reproducible with the command line tool, but it's easier to reproduce by importing lib2to3. You just need different processes importing lib2to3 at the same time to make this happen, see the attached reproducer. I tried with Python 3.9 for completeness and, while it happens there as well, it seems to be less frequent ony my computer than when using Python 3.6 (2% failure rate instead of 50% failure rate).

Content

The generation of pickle files in load_grammar in lib2to3/pgen2/driver.py is racy as other processes may end up reading a half-written pickle file.
This is reproducible with the command line tool, but it's easier to reproduce by importing lib2to3. You just need different processes importing lib2to3 at the same time to make this happen, see the attached reproducer.
I tried with Python 3.9 for completeness and, while it happens there as well, it seems to be less frequent ony my computer than when using Python 3.6 (2% failure rate instead of 50% failure rate).

History
Date	User	Action	Args
2020年07月01日 16:05:44	barisione	set	recipients: + barisione
2020年07月01日 16:05:44	barisione	set	messageid: <1593619544.94.0.691494373061.issue41185@roundup.psfhosted.org>
2020年07月01日 16:05:44	barisione	link	issue41185 messages
2020年07月01日 16:05:44	barisione	create

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