https://github.com/python/cpython/commit/6112d70abee2455bfa44a76a49a5a80472e21134
commit: 6112d70abee2455bfa44a76a49a5a80472e21134
branch: main
author: Kumar Aditya <[email protected]>
committer: kumaraditya303 <[email protected]>
date: 2026-06-11T21:37:00+05:30
summary:
gh-151228: fix data race on clearing embedded dict values (#151330)
files:
M Lib/test/test_free_threading/test_dict.py
M Objects/dictobject.c
diff --git a/Lib/test/test_free_threading/test_dict.py
b/Lib/test/test_free_threading/test_dict.py
index dfe0634211d4b02..ad23290a92ab345 100644
--- a/Lib/test/test_free_threading/test_dict.py
+++ b/Lib/test/test_free_threading/test_dict.py
@@ -296,6 +296,24 @@ def reader():
threading_helper.run_concurrently([clearer, reader, reader])
+ def test_racing_embedded_values_clear_and_lookup(self):
+ class C:
+ pass
+
+ obj = C()
+ def writer():
+ for _ in range(1000):
+ obj.x = 1
+ obj.y = 2
+ obj.z = 3
+ obj.__dict__.clear()
+
+ def reader():
+ for _ in range(1000):
+ obj.__dict__.get('x')
+
+ threading_helper.run_concurrently([writer, reader, reader])
+
def test_racing_dict_update_and_method_lookup(self):
# gh-144295: test race between dict modifications and method lookups.
# Uses BytesIO because the race requires a type without
Py_TPFLAGS_INLINE_VALUES
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index e279c8765dd464a..25dc81f726f59cb 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -3039,7 +3039,7 @@ clear_embedded_values(PyDictValues *values, Py_ssize_t
nentries)
assert(nentries <= SHARED_KEYS_MAX_SIZE);
for (Py_ssize_t i = 0; i < nentries; i++) {
refs[i] = values->values[i];
- values->values[i] = NULL;
+ FT_ATOMIC_STORE_PTR_RELEASE(values->values[i], NULL);
}
values->size = 0;
for (Py_ssize_t i = 0; i < nentries; i++) {
_______________________________________________
Python-checkins mailing list -- [email protected]
To unsubscribe send an email to [email protected]
https://mail.python.org/mailman3//lists/python-checkins.python.org
Member address: [email protected]
