[Python-checkins] GH-106485: Create object's dict-values instead of creating __dict__, when we can. (GH-107843)

[markshannon]

https://github.com/python/cpython/commit/666b68e8f252e3c6238d6eed1fc82937a774316f
commit: 666b68e8f252e3c6238d6eed1fc82937a774316f
branch: main
author: Mark Shannon <mark at hotpy.org>
committer: markshannon <mark at hotpy.org>
date: 2023-08-11T20:05:56+01:00
summary:

GH-106485: Create object's dict-values instead of creating __dict__, when we can. (GH-107843)

files:
M Objects/dictobject.c
M Objects/object.c

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 36375f50646fd..f9701f6b4b09a 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -5762,10 +5762,8 @@ _PyObjectDict_SetItem(PyTypeObject *tp, PyObject **dictptr,
         assert(dictptr != NULL);
         dict = *dictptr;
         if (dict == NULL) {
+            assert(!_PyType_HasFeature(tp, Py_TPFLAGS_MANAGED_DICT));
             dictkeys_incref(cached);
-            if (_PyType_HasFeature(tp, Py_TPFLAGS_MANAGED_DICT)) {
-                OBJECT_STAT_INC(dict_materialized_on_request);
-            }
             dict = new_dict_with_shared_keys(interp, cached);
             if (dict == NULL)
                 return -1;
diff --git a/Objects/object.c b/Objects/object.c
index d1154eb344fab..868623a9f7bff 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1577,6 +1577,14 @@ _PyObject_GenericSetAttrWithDict(PyObject *obj, PyObject *name,
                 goto error_check;
             }
             dictptr = &dorv_ptr->dict;
+            if (*dictptr == NULL) {
+                if (_PyObject_InitInlineValues(obj, tp) < 0) {
+                    goto done;
+                }
+                res = _PyObject_StoreInstanceAttribute(
+                    obj, _PyDictOrValues_GetValues(*dorv_ptr), name, value);
+                goto error_check;
+            }
         }
         else {
             dictptr = _PyObject_ComputedDictPointer(obj);