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[mypyc] Make tagged int attributes memory safe under free threading - #22203
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…ding It can still leak memory if there is a race condition involving big integers (e.g. 2**62 or larger on a 64-bit platform). This is a compromise to avoid slowing down very common (and fast) operations. Work on mypyc/mypyc#1203.
p-sawicki
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Oct 16, 2026
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This broke master again. I know move fast and break things is cool, but it is actually not. |
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This conflicted with #22073, I think. I'm working on a forward fix. |
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I guess we should merge master and let CI run before merging a PR when there is a lot of commit activity and the PR has been open for a few days. |
JukkaL
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Previously native tagged
intattributes used completely unsynchronizedaccess, which could result in use after free or double frees. Fix the
memory safety issues, but only synchronize if an int has a long value
(tag bit set and not undefined).
It can still leak memory if there is a race condition involving long
integers (e.g. 2**62 or larger on a 64-bit platform). This is a compromise
to avoid slowing down very common (and fast) operations with short
tagged integers.
The implementation is otherwise similar to attributes with regular
reference types.
This doesn't have a measurable impact on self check performance
on Python 3.14t.
Work on mypyc/mypyc#1203.