Avoid locking in _LOAD_ATTR_WITH_HINT

Author: DinoV

Include/internal/pycore_dict.h

@@ -149,6 +149,8 @@ extern int _PyDict_Pop_KnownHash(
     Py_hash_t hash,
     PyObject **result);
 
+PyAPI_FUNC(void) _PyDict_EnsureSharedOnRead(PyDictObject *mp);
+
 #define DKIX_EMPTY (-1)
 #define DKIX_DUMMY (-2)  /* Used internally */
 #define DKIX_ERROR (-3)

Include/internal/pycore_opcode_metadata.h

@@ -1323,6 +1323,12 @@ ensure_shared_on_read(PyDictObject *mp)
         Py_END_CRITICAL_SECTION();
     }
 }
+
+void
+_PyDict_EnsureSharedOnRead(PyDictObject *mp)
+{
+    ensure_shared_on_read(mp);
+}
 #endif
 
 static inline void

Include/internal/pycore_uop_metadata.h

@@ -2286,38 +2286,38 @@ dummy_func(
         }
 
         op(_LOAD_ATTR_WITH_HINT, (hint/1, owner, dict: PyDictObject * -- attr)) {
+            _PyDict_EnsureSharedOnRead(dict);
+
+            PyDictKeysObject *dk = FT_ATOMIC_LOAD_PTR(dict->ma_keys);
             PyObject *attr_o;
-            if (!LOCK_OBJECT(dict)) {
+            if (hint >= (size_t)dk->dk_nentries) {
                 POP_INPUT(dict);
                 DEOPT_IF(true);
             }
-
-            if (hint >= (size_t)dict->ma_keys->dk_nentries) {
-                UNLOCK_OBJECT(dict);
+            PyObject *name = GETITEM(FRAME_CO_NAMES, oparg>>1);
+            if (dk->dk_kind != DICT_KEYS_UNICODE) {
                 POP_INPUT(dict);
                 DEOPT_IF(true);
             }
-            PyObject *name = GETITEM(FRAME_CO_NAMES, oparg>>1);
-            if (dict->ma_keys->dk_kind != DICT_KEYS_UNICODE) {
-                UNLOCK_OBJECT(dict);
+            PyDictUnicodeEntry *ep = DK_UNICODE_ENTRIES(dk) + hint;
+            if (FT_ATOMIC_LOAD_PTR_RELAXED(ep->me_key) != name) {
                 POP_INPUT(dict);
                 DEOPT_IF(true);
             }
-            PyDictUnicodeEntry *ep = DK_UNICODE_ENTRIES(dict->ma_keys) + hint;
-            if (ep->me_key != name) {
-                UNLOCK_OBJECT(dict);
+            attr_o = FT_ATOMIC_LOAD_PTR(ep->me_value);
+            if (attr_o == NULL) {
                 POP_INPUT(dict);
                 DEOPT_IF(true);
             }
-            attr_o = ep->me_value;
-            if (attr_o == NULL) {
-                UNLOCK_OBJECT(dict);
+#ifdef Py_GIL_DISABLED
+            if (!_Py_TryIncrefCompareStackRef(&ep->me_value, attr_o, &attr)) {
                 POP_INPUT(dict);
                 DEOPT_IF(true);
             }
-            STAT_INC(LOAD_ATTR, hit);
+#else
             attr = PyStackRef_FromPyObjectNew(attr_o);
-            UNLOCK_OBJECT(dict);
+#endif
+            STAT_INC(LOAD_ATTR, hit);
             DEAD(dict);
             DECREF_INPUTS();
         }