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gh-117657: use relaxed loads for checking dict keys immortality #118067

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Merged
merged 1 commit into from
Apr 19, 2024
Merged

gh-117657: use relaxed loads for checking dict keys immortality #118067

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4 changes: 2 additions & 2 deletions Objects/dictobject.c
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Original file line number Diff line number Diff line change
Expand Up @@ -441,7 +441,7 @@ static void free_keys_object(PyDictKeysObject *keys, bool use_qsbr);
static inline void
dictkeys_incref(PyDictKeysObject *dk)
{
if (dk->dk_refcnt == _Py_IMMORTAL_REFCNT) {
if (FT_ATOMIC_LOAD_SSIZE_RELAXED(dk->dk_refcnt) == _Py_IMMORTAL_REFCNT) {
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We could also do dk == Py_EMPTY_KEYS and avoid the atomics, but this seems fine too.

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I kind of like that, but am a little worried that it'll be overlooked if any other keys become immortal, so I'll just keep it as-is for now.

return;
}
#ifdef Py_REF_DEBUG
Expand All @@ -453,7 +453,7 @@ dictkeys_incref(PyDictKeysObject *dk)
static inline void
dictkeys_decref(PyInterpreterState *interp, PyDictKeysObject *dk, bool use_qsbr)
{
if (dk->dk_refcnt == _Py_IMMORTAL_REFCNT) {
if (FT_ATOMIC_LOAD_SSIZE_RELAXED(dk->dk_refcnt) == _Py_IMMORTAL_REFCNT) {
return;
}
assert(dk->dk_refcnt > 0);
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2 changes: 0 additions & 2 deletions Tools/tsan/suppressions_free_threading.txt
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Expand Up @@ -29,8 +29,6 @@ race:_PyType_HasFeature
race:assign_version_tag
race:compare_unicode_unicode
race:delitem_common
race:dictkeys_decref
race:dictkeys_incref
race:dictresize
race:gc_collect_main
race:gc_restore_tid
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