Mailing List Archive

https://github.com/python/cpython/commit/5da0280648b5f1c5142dad39dcd1e7fd99fdf37a
commit: 5da0280648b5f1c5142dad39dcd1e7fd99fdf37a
branch: main
author: Dino Viehland <dinoviehland@meta.com>
committer: DinoV <dinoviehland@gmail.com>
date: 2024-04-25T08:53:29-07:00
summary:

gh-117657: Fixes a few small TSAN issues in dictobject (#118200)

Fixup TSAN errors for dict

files:
M Include/cpython/dictobject.h
M Include/internal/pycore_object.h
M Objects/dictobject.c
M Tools/tsan/suppressions_free_threading.txt

diff --git a/Include/cpython/dictobject.h b/Include/cpython/dictobject.h
index 35b6a822a0dfff..3fd23b9313c453 100644
--- a/Include/cpython/dictobject.h
+++ b/Include/cpython/dictobject.h
@@ -56,7 +56,11 @@ static inline Py_ssize_t PyDict_GET_SIZE(PyObject *op) {
PyDictObject *mp;
assert(PyDict_Check(op));
mp = _Py_CAST(PyDictObject*, op);
+#ifdef Py_GIL_DISABLED
+ return _Py_atomic_load_ssize_relaxed(&mp->ma_used);
+#else
return mp->ma_used;
+#endif
}
#define PyDict_GET_SIZE(op) PyDict_GET_SIZE(_PyObject_CAST(op))

diff --git a/Include/internal/pycore_object.h b/Include/internal/pycore_object.h
index 88b052f4544b15..7df8003196d8cc 100644
--- a/Include/internal/pycore_object.h
+++ b/Include/internal/pycore_object.h
@@ -688,7 +688,7 @@ static inline PyDictObject *
_PyObject_GetManagedDict(PyObject *obj)
{
PyManagedDictPointer *dorv = _PyObject_ManagedDictPointer(obj);
- return (PyDictObject *)FT_ATOMIC_LOAD_PTR_RELAXED(dorv->dict);
+ return (PyDictObject *)FT_ATOMIC_LOAD_PTR_ACQUIRE(dorv->dict);
}

static inline PyDictValues *
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 2644516bc30770..afcf535f8c0a78 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1097,10 +1097,11 @@ compare_unicode_unicode(PyDictObject *mp, PyDictKeysObject *dk,
void *ep0, Py_ssize_t ix, PyObject *key, Py_hash_t hash)
{
PyDictUnicodeEntry *ep = &((PyDictUnicodeEntry *)ep0)[ix];
- assert(ep->me_key != NULL);
- assert(PyUnicode_CheckExact(ep->me_key));
- if (ep->me_key == key ||
- (unicode_get_hash(ep->me_key) == hash && unicode_eq(ep->me_key, key))) {
+ PyObject *ep_key = FT_ATOMIC_LOAD_PTR_RELAXED(ep->me_key);
+ assert(ep_key != NULL);
+ assert(PyUnicode_CheckExact(ep_key));
+ if (ep_key == key ||
+ (unicode_get_hash(ep_key) == hash && unicode_eq(ep_key, key))) {
return 1;
}
return 0;
@@ -1761,10 +1762,12 @@ insertdict(PyInterpreterState *interp, PyDictObject *mp,
else {
assert(old_value != NULL);
if (DK_IS_UNICODE(mp->ma_keys)) {
- DK_UNICODE_ENTRIES(mp->ma_keys)[ix].me_value = value;
+ PyDictUnicodeEntry *ep = &DK_UNICODE_ENTRIES(mp->ma_keys)[ix];
+ STORE_VALUE(ep, value);
}
else {
- DK_ENTRIES(mp->ma_keys)[ix].me_value = value;
+ PyDictKeyEntry *ep = &DK_ENTRIES(mp->ma_keys)[ix];
+ STORE_VALUE(ep, value);
}
}
mp->ma_version_tag = new_version;
@@ -1810,15 +1813,15 @@ insert_to_emptydict(PyInterpreterState *interp, PyDictObject *mp,
if (unicode) {
PyDictUnicodeEntry *ep = DK_UNICODE_ENTRIES(newkeys);
ep->me_key = key;
- ep->me_value = value;
+ STORE_VALUE(ep, value);
}
else {
PyDictKeyEntry *ep = DK_ENTRIES(newkeys);
ep->me_key = key;
ep->me_hash = hash;
- ep->me_value = value;
+ STORE_VALUE(ep, value);
}
- mp->ma_used++;
+ FT_ATOMIC_STORE_SSIZE_RELAXED(mp->ma_used, FT_ATOMIC_LOAD_SSIZE_RELAXED(mp->ma_used) + 1);
mp->ma_version_tag = new_version;
newkeys->dk_usable--;
newkeys->dk_nentries++;
@@ -2510,7 +2513,7 @@ delitem_common(PyDictObject *mp, Py_hash_t hash, Py_ssize_t ix,
Py_ssize_t hashpos = lookdict_index(mp->ma_keys, hash, ix);
assert(hashpos >= 0);

- mp->ma_used--;
+ FT_ATOMIC_STORE_SSIZE_RELAXED(mp->ma_used, FT_ATOMIC_LOAD_SSIZE(mp->ma_used) - 1);
mp->ma_version_tag = new_version;
if (_PyDict_HasSplitTable(mp)) {
assert(old_value == mp->ma_values->values[ix]);
@@ -6895,7 +6898,7 @@ _PyObject_TryGetInstanceAttribute(PyObject *obj, PyObject *name, PyObject **attr
}

#ifdef Py_GIL_DISABLED
- PyObject *value = _Py_atomic_load_ptr_relaxed(&values->values[ix]);
+ PyObject *value = _Py_atomic_load_ptr_acquire(&values->values[ix]);
if (value == NULL || _Py_TryIncrefCompare(&values->values[ix], value)) {
*attr = value;
return true;
diff --git a/Tools/tsan/suppressions_free_threading.txt b/Tools/tsan/suppressions_free_threading.txt
index aa954ca9b6c09c..e4ca32bebc5a22 100644
--- a/Tools/tsan/suppressions_free_threading.txt
+++ b/Tools/tsan/suppressions_free_threading.txt
@@ -28,9 +28,6 @@ race:_PyObject_GC_TRACK
race:_PyParkingLot_Park
race:_PyType_HasFeature
race:assign_version_tag
-race:compare_unicode_unicode
-race:delitem_common
-race:dictresize
race:gc_collect_main
race:gc_restore_tid
race:initialize_new_array

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