Skip to content

gh-153881: Atomically load dk_nentries in _PyObject_IsInstanceDictEmpty #153882

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kumaraditya303 merged 3 commits into from
Jul 21, 2026
Merged

gh-153881: Atomically load dk_nentries in _PyObject_IsInstanceDictEmpty #153882

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
8976129
gh-153881: Atomically load `dk_nentries` in `_PyObject_IsInstanceDict…
brijkapadia Jul 18, 2026
89a09c3
Update NEWS
brijkapadia Jul 18, 2026
9c26ed2
small change
brijkapadia Jul 18, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
gh-153881: Atomically load dk_nentries in `_PyObject_IsInstanceDict… 
…Empty`
  • Loading branch information
@brijkapadia
brijkapadia committed Jul 18, 2026
commit 8976129dd2bf0d21493a4e22c067059916b066d2
20 changes: 20 additions & 0 deletions Lib/test/test_free_threading/test_dict.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -336,5 +336,25 @@ def reader():
with threading_helper.start_threads([t1, t2]):
pass

def test_getstate_race_with_shared_keys(self):
box = [None]
enter = Barrier(2)
leave = Barrier(2)

def reader():
for _ in range(1000):
enter.wait()
box[0].__getstate__()
leave.wait()

def writer():
for i in range(1000):
box[0] = type(f"C{i}", (), {})()
enter.wait()
setattr(box[0], str(i), 1)
leave.wait()

threading_helper.run_concurrently([reader, writer])

if __name__ == "__main__":
unittest.main()
1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Core_and_Builtins/2026-07-17-22-03-39.gh-issue-153881.oDa06s.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Fix potential data race when calling :meth:`object.__getstate__`.
Comment thread
brijkapadia marked this conversation as resolved.
Outdated
2 changes: 1 addition & 1 deletion Objects/dictobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7722,7 +7722,7 @@ _PyObject_IsInstanceDictEmpty(PyObject *obj)
PyDictValues *values = _PyObject_InlineValues(obj);
if (FT_ATOMIC_LOAD_UINT8(values->valid)) {
PyDictKeysObject *keys = CACHED_KEYS(tp);
for (Py_ssize_t i = 0; i < keys->dk_nentries; i++) {
for (Py_ssize_t i = 0; i < LOAD_KEYS_NENTRIES(keys); i++) {
if (FT_ATOMIC_LOAD_PTR_RELAXED(values->values[i]) != NULL) {
return 0;
}
Expand Down
Loading