Add freelist for Decimal's

Author: skirpichev

Include/internal/pycore_freelist_state.h

@@ -17,6 +17,7 @@ extern "C" {
 #  define Py_dictkeys_MAXFREELIST 80
 #  define Py_floats_MAXFREELIST 100
 #  define Py_complexes_MAXFREELIST 100
+#  define Py_decimals_MAXFREELIST 100
 #  define Py_ints_MAXFREELIST 100
 #  define Py_slices_MAXFREELIST 1
 #  define Py_ranges_MAXFREELIST 6
@@ -47,6 +48,7 @@ struct _Py_freelists {
     struct _Py_freelist floats;
     struct _Py_freelist complexes;
     struct _Py_freelist ints;
+    struct _Py_freelist decimals;
     struct _Py_freelist tuples[PyTuple_MAXSAVESIZE];
     struct _Py_freelist lists;
     struct _Py_freelist list_iters;

Modules/_decimal/_decimal.c

@@ -30,6 +30,7 @@
 #endif
 
 #include <Python.h>
+#include "pycore_freelist.h"      // _Py_FREELIST_POP()
 #include "pycore_object.h"        // _PyObject_VisitType()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
 #include "pycore_typeobject.h"
@@ -2196,7 +2197,10 @@ PyDecType_New(decimal_state *state, PyTypeObject *type)
     PyDecObject *dec;
 
     if (type == state->PyDec_Type) {
-        dec = PyObject_GC_New(PyDecObject, state->PyDec_Type);
+        dec = _Py_FREELIST_POP(PyDecObject, decimals);
+        if (dec == NULL) {
+            dec = PyObject_GC_New(PyDecObject, state->PyDec_Type);
+        }
     }
     else {
         dec = (PyDecObject *)type->tp_alloc(type, 0);
@@ -2226,10 +2230,16 @@ static void
 dec_dealloc(PyObject *dec)
 {
     PyTypeObject *tp = Py_TYPE(dec);
+    decimal_state *state = get_module_state_by_def(tp);
+
     PyObject_GC_UnTrack(dec);
     mpd_del(MPD(dec));
-    tp->tp_free(dec);
-    Py_DECREF(tp);
+    if (!PyDec_CheckExact(state, dec)
+        || !_Py_FREELIST_PUSH(decimals, dec, Py_decimals_MAXFREELIST))
+    {
+        tp->tp_free(dec);
+        Py_DECREF(tp);
+    }
 }
 
 

Objects/object.c

@@ -951,6 +951,7 @@ _PyObject_ClearFreeLists(struct _Py_freelists *freelists, int is_finalization)
     clear_freelist(&freelists->pycfunctionobject, is_finalization, PyObject_GC_Del);
     clear_freelist(&freelists->pycmethodobject, is_finalization, PyObject_GC_Del);
     clear_freelist(&freelists->pymethodobjects, is_finalization, free_object);
+    clear_freelist(&freelists->decimals, is_finalization, free_object);
 }
 
 /*