[3.15] gh-151644: Fix data race in sys.setdlopenflags/getdlopenflags under free-threading (gh-151768) - #153790
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…nder free-threading (pythongh-151768) In free-threading builds, concurrent calls to sys.getdlopenflags() and sys.setdlopenflags() race on interp->imports.dlopenflags. Fix by using FT_ATOMIC_LOAD_INT_RELAXED / FT_ATOMIC_STORE_INT_RELAXED in _PyImport_GetDLOpenFlags and _PyImport_SetDLOpenFlags, consistent with how analogous interpreter-state integer fields (lazy_imports_mode, pystats_enabled) are protected. Relaxed ordering is correct here: dlopenflags is a standalone config integer with no ordering relationship to other memory. (cherry picked from commit cde31ec) Co-authored-by: Jiucheng(Oliver) <git.jiucheng@gmail.com> Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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July 16, 2026 01:47
This was referenced Jul 16, 2026
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In free-threading builds, concurrent calls to sys.getdlopenflags() and
sys.setdlopenflags() race on interp->imports.dlopenflags. Fix by
using FT_ATOMIC_LOAD_INT_RELAXED / FT_ATOMIC_STORE_INT_RELAXED in
_PyImport_GetDLOpenFlags and _PyImport_SetDLOpenFlags, consistent with
how analogous interpreter-state integer fields (lazy_imports_mode,
pystats_enabled) are protected.
Relaxed ordering is correct here: dlopenflags is a standalone config
integer with no ordering relationship to other memory.
(cherry picked from commit cde31ec)
Co-authored-by: Jiucheng(Oliver) git.jiucheng@gmail.com
Co-Authored-By: Claude Sonnet 4.6 noreply@anthropic.com