gh-111968: Split _Py_dictkeys_freelist out of _Py_dict_freelist

Author: corona10

Include/internal/pycore_freelist.h

@@ -71,6 +71,14 @@ struct _Py_dict_freelist {
 #ifdef WITH_FREELISTS
     /* Dictionary reuse scheme to save calls to malloc and free */
     PyDictObject *free_list[PyDict_MAXFREELIST];
+    int numfree;
+    int keys_numfree;
+#endif
+};
+
+struct _Py_dictkeys_freelist {
+#ifdef WITH_FREELISTS
+    /* Dictionary keys reuse scheme to save calls to malloc and free */
     PyDictKeysObject *keys_free_list[PyDict_MAXFREELIST];
     int numfree;
     int keys_numfree;
@@ -119,6 +127,7 @@ struct _Py_object_freelists {
     struct _Py_tuple_freelist tuples;
     struct _Py_list_freelist lists;
     struct _Py_dict_freelist dicts;
+    struct _Py_dictkeys_freelist dictkeys;
     struct _Py_slice_freelist slices;
     struct _Py_context_freelist contexts;
     struct _Py_async_gen_freelist async_gens;

Objects/dictobject.c

@@ -276,25 +276,35 @@ get_dict_freelist(void)
     struct _Py_object_freelists *freelists = _Py_object_freelists_GET();
     return &freelists->dicts;
 }
+
+static struct _Py_dictkeys_freelist *
+get_dictkeys_freelist(void)
+{
+    struct _Py_object_freelists *freelists = _Py_object_freelists_GET();
+    return &freelists->dictkeys;
+}
 #endif
 
 
 void
 _PyDict_ClearFreeList(struct _Py_object_freelists *freelists, int is_finalization)
 {
 #ifdef WITH_FREELISTS
-    struct _Py_dict_freelist *state = &freelists->dicts;
-    while (state->numfree > 0) {
-        PyDictObject *op = state->free_list[--state->numfree];
+    struct _Py_dict_freelist *dict_freelist = &freelists->dicts;
+    while (dict_freelist->numfree > 0) {
+        PyDictObject *op = dict_freelist->free_list[--dict_freelist->numfree];
         assert(PyDict_CheckExact(op));
         PyObject_GC_Del(op);
     }
-    while (state->keys_numfree > 0) {
-        PyMem_Free(state->keys_free_list[--state->keys_numfree]);
+    struct _Py_dictkeys_freelist *dictkeys_freelist = &freelists->dictkeys;
+    while (dictkeys_freelist->keys_numfree > 0) {
+        PyMem_Free(dictkeys_freelist->keys_free_list[--dictkeys_freelist->keys_numfree]);
     }
     if (is_finalization) {
-        state->numfree = -1;
-        state->keys_numfree = -1;
+        dict_freelist->numfree = -1;
+        dict_freelist->keys_numfree = -1;
+        dictkeys_freelist->numfree = -1;
+        dictkeys_freelist->keys_numfree = -1;
     }
 #endif
 }
@@ -314,6 +324,9 @@ _PyDict_DebugMallocStats(FILE *out)
     struct _Py_dict_freelist *dict_freelist = get_dict_freelist();
     _PyDebugAllocatorStats(out, "free PyDictObject",
                            dict_freelist->numfree, sizeof(PyDictObject));
+    struct _Py_dictkeys_freelist *dictkeys_freelist = get_dictkeys_freelist();
+    _PyDebugAllocatorStats(out, "free PyDictKeysObject",
+                           dictkeys_freelist->numfree, sizeof(PyDictKeysObject));
 #endif
 }
 
@@ -663,9 +676,9 @@ new_keys_object(PyInterpreterState *interp, uint8_t log2_size, bool unicode)
     }
 
 #ifdef WITH_FREELISTS
-    struct _Py_dict_freelist *dict_freelist = get_dict_freelist();
-    if (log2_size == PyDict_LOG_MINSIZE && unicode && dict_freelist->keys_numfree > 0) {
-        dk = dict_freelist->keys_free_list[--dict_freelist->keys_numfree];
+    struct _Py_dictkeys_freelist *dictkey_freelist = get_dictkeys_freelist();
+    if (log2_size == PyDict_LOG_MINSIZE && unicode && dictkey_freelist->keys_numfree > 0) {
+        dk = dictkey_freelist->keys_free_list[--dictkey_freelist->keys_numfree];
         OBJECT_STAT_INC(from_freelist);
     }
     else
@@ -698,12 +711,12 @@ static void
 free_keys_object(PyDictKeysObject *keys)
 {
 #ifdef WITH_FREELISTS
-    struct _Py_dict_freelist *dict_freelist = get_dict_freelist();
+    struct _Py_dictkeys_freelist *dictkey_freelist = get_dictkeys_freelist();
     if (DK_LOG_SIZE(keys) == PyDict_LOG_MINSIZE
-            && dict_freelist->keys_numfree < PyDict_MAXFREELIST
-            && dict_freelist->keys_numfree >= 0
+            && dictkey_freelist->keys_numfree < PyDict_MAXFREELIST
+            && dictkey_freelist->keys_numfree >= 0
             && DK_IS_UNICODE(keys)) {
-        dict_freelist->keys_free_list[dict_freelist->keys_numfree++] = keys;
+        dictkey_freelist->keys_free_list[dictkey_freelist->keys_numfree++] = keys;
         OBJECT_STAT_INC(to_freelist);
         return;
     }