gh-91401: Add a failsafe way to disable vfork. #91490
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Just in case there is ever an issue with _posixsubprocess's use of vfork() due to the complexity of using it properly and potential directions that Linux platforms where it defaults to on could take, this adds a failsafe so that users can disable its use entirely by setting a global flag. No known reason to disable it exists. But it'd be a shame to encounter one and not be able to use CPython without patching and rebuilding it. See the linked issue for some discussion on reasoning.
gpshead
added
type-bug
vstinner
reviewed
Apr 19, 2022
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I added |
Being consistent with that seems worthwhile, I'll rework this PR. I expect I'm overthinking it with the whole "make it a string" thing and pleading for people to include an explanation of why. |
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I chose to add a private attribute since the default value must be safe for all users. But for the corner cases, IMO a private attribute is enough. For vfork, well, it's up to you to add a private or public attribute. |
No double negatives. Also documents _USE_POSIX_SPAWN.
Rather than re-encoding our platform selection here (configure.ac and runtime logic in _posixsubprocess already does that).
vstinner
approved these changes
Apr 25, 2022
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| .. versionadded:: 3.8 ``_USE_POSIX_SPAWN`` | ||
| .. versionadded:: 3.11 ``_USE_VFORK`` |
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I never tried this syntax, I don't know if it's properly rendered. You will see :-)
JelleZijlstra
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Apr 26, 2022
Debatable whether to include these, but they are now documented: python/cpython#91490
AlexWaygood
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Apr 26, 2022
These are now documented: python/cpython#91490
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Just in case there is ever an issue with
_posixsubprocess's use ofvfork()due to the complexity of using it properly and potentialdirections that Linux platforms where it defaults to on could take, this
adds a failsafe so that users can disable its use entirely by setting
a global flag.
No known reason to disable it exists. But it'd be a shame to encounter
one and not be able to use CPython without patching and rebuilding it.
See the linked issue for some discussion on reasoning.