Remove unneeded atomics for tp_flags.

Author: nascheme

Include/internal/pycore_object.h

@@ -311,7 +311,7 @@ extern int _PyDict_CheckConsistency(PyObject *mp, int check_content);
 // Fast inlined version of PyType_HasFeature()
 static inline int
 _PyType_HasFeature(PyTypeObject *type, unsigned long feature) {
-    return ((FT_ATOMIC_LOAD_ULONG_RELAXED(type->tp_flags) & feature) != 0);
+    return ((type->tp_flags) & feature) != 0;
 }
 
 extern void _PyType_InitCache(PyInterpreterState *interp);

Include/object.h

@@ -776,11 +776,7 @@ PyType_HasFeature(PyTypeObject *type, unsigned long feature)
     // PyTypeObject is opaque in the limited C API
     flags = PyType_GetFlags(type);
 #else
-#   ifdef Py_GIL_DISABLED
-        flags = _Py_atomic_load_ulong_relaxed(&type->tp_flags);
-#   else
-        flags = type->tp_flags;
-#   endif
+    flags = type->tp_flags;
 #endif
     return ((flags & feature) != 0);
 }

Objects/typeobject.c

@@ -353,9 +353,7 @@ type_set_flags(PyTypeObject *tp, unsigned long flags)
         // held when flags are modified.
         ASSERT_TYPE_LOCK_HELD();
     }
-    // Since PyType_HasFeature() reads the flags without holding the type
-    // lock, we need an atomic store here.
-    FT_ATOMIC_STORE_ULONG_RELAXED(tp->tp_flags, flags);
+    tp->tp_flags = flags;
 }
 
 static void
@@ -3690,7 +3688,7 @@ type_init(PyObject *cls, PyObject *args, PyObject *kwds)
 unsigned long
 PyType_GetFlags(PyTypeObject *type)
 {
-    return FT_ATOMIC_LOAD_ULONG_RELAXED(type->tp_flags);
+    return type->tp_flags;
 }