mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-31 05:58:33 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 7

gh-117657: Fix data races when writing / reading ob_gc_bits (#118292)

Browse source 
Use relaxed atomics when reading / writing to the field. There are still a
few places in the GC where we do not use atomics. Those should be safe as
the world is stopped.
This commit is contained in:
mpage 2024-05-08 13:03:39 -07:00 • committed by GitHub
parent 8d84120b41
commit cb6f75a32c
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
4 changed files with 45 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

6
Include/internal/pycore_object.h
View file

@ -168,7 +168,7 @@ static inline int
_PyObject_HasDeferredRefcount(PyObject *op)
{
#ifdef Py_GIL_DISABLED
return (op->ob_gc_bits & _PyGC_BITS_DEFERRED) != 0;
return _PyObject_HAS_GC_BITS(op, _PyGC_BITS_DEFERRED);
#else
return 0;
#endif
@ -320,7 +320,7 @@ static inline void _PyObject_GC_TRACK(
"object already tracked by the garbage collector",
filename, lineno, __func__);
#ifdef Py_GIL_DISABLED
op->ob_gc_bits |= _PyGC_BITS_TRACKED;
_PyObject_SET_GC_BITS(op, _PyGC_BITS_TRACKED);
#else
PyGC_Head *gc = _Py_AS_GC(op);
_PyObject_ASSERT_FROM(op,
@ -361,7 +361,7 @@ static inline void _PyObject_GC_UNTRACK(
filename, lineno, __func__);
#ifdef Py_GIL_DISABLED
op->ob_gc_bits &= ~_PyGC_BITS_TRACKED;
_PyObject_CLEAR_GC_BITS(op, _PyGC_BITS_TRACKED);
#else
PyGC_Head *gc = _Py_AS_GC(op);
PyGC_Head *prev = _PyGCHead_PREV(gc);