Add tests

Author: wrongnull

Lib/test/test_free_threading/test_races.py

@@ -270,6 +270,25 @@ def mutate():
 
         do_race(set_value, mutate)
 
+    def test_generic_getattr(self):
+        """Test generic attribute load"""
+        import concurrent.futures
+
+        num_threads = 100
+
+
+        def closure(b, o):
+            b.wait()
+            getattr(o, "foo", None)
+            o.foo = 42
+
+        with concurrent.futures.ThreadPoolExecutor(max_workers=num_threads) as executor:
+            for _ in range(100):
+                b = threading.Barrier(num_threads)
+                o = functools.partial(lambda x: x, 42)
+                for _ in range(num_threads):
+                    executor.submit(functools.partial(closure, b, o))
+
 
 if __name__ == "__main__":
     unittest.main()

Objects/object.c

@@ -1716,13 +1716,13 @@ _PyObject_GenericGetAttrWithDict(PyObject *obj, PyObject *name,
         }
         else {
             Py_BEGIN_CRITICAL_SECTION(obj);
-            PyObject **dictptr = _PyObject_ComputedDictPointer(obj);
-            if (dictptr) {
 #ifdef DISABLE_GIL
-                dict = (PyObject *)_Py_atomic_load_ptr(dictptr);
+            PyObject **dictptr = _Py_atomic_load_ptr(_PyObject_ComputedDictPointer(obj));
 #else
-                dict = *dictptr;
+            PyObject **dictptr = _PyObject_ComputedDictPointer(obj);
 #endif
+            if (dictptr) {
+                dict = *dictptr;
             }
             Py_END_CRITICAL_SECTION();
         }