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gh-126703: Add freelists for list and tuple iterators (GH-128592)

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Pieter Eendebak 2025-01-29 10:15:24 +01:00 committed by GitHub
parent 41ad2bb248
commit 1a80214f11
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GPG Key ID: B5690EEEBB952194
5 changed files with 24 additions and 12 deletions
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4
Include/internal/pycore_freelist_state.h
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@ -11,6 +11,8 @@ extern "C" {
# define PyTuple_MAXSAVESIZE 20 // Largest tuple to save on freelist
# define Py_tuple_MAXFREELIST 2000 // Maximum number of tuples of each size to save
# define Py_lists_MAXFREELIST 80
# define Py_list_iters_MAXFREELIST 10
# define Py_tuple_iters_MAXFREELIST 10
# define Py_dicts_MAXFREELIST 80
# define Py_dictkeys_MAXFREELIST 80
# define Py_floats_MAXFREELIST 100
@ -40,6 +42,8 @@ struct _Py_freelists {
struct _Py_freelist ints;
struct _Py_freelist tuples[PyTuple_MAXSAVESIZE];
struct _Py_freelist lists;
struct _Py_freelist list_iters;
struct _Py_freelist tuple_iters;
struct _Py_freelist dicts;
struct _Py_freelist dictkeys;
struct _Py_freelist slices;

1
Misc/NEWS.d/next/Core_and_Builtins/2025-01-07-19-26-40.gh-issue-126703.9i-S5t.rst Normal file
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@ -0,0 +1 @@
Improve performance of iterating over lists and tuples by using a freelist for the iterator objects.

11
Objects/listobject.c
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@ -3903,15 +3903,17 @@ PyTypeObject PyListIter_Type = {
static PyObject *
list_iter(PyObject *seq)
{
_PyListIterObject *it;
if (!PyList_Check(seq)) {
PyErr_BadInternalCall();
return NULL;
}
_PyListIterObject *it = _Py_FREELIST_POP(_PyListIterObject, list_iters);
if (it == NULL) {
it = PyObject_GC_New(_PyListIterObject, &PyListIter_Type);
if (it == NULL)
if (it == NULL) {
return NULL;
}
}
it->it_index = 0;
it->it_seq = (PyListObject *)Py_NewRef(seq);
_PyObject_GC_TRACK(it);
@ -3924,7 +3926,8 @@ listiter_dealloc(PyObject *self)
_PyListIterObject *it = (_PyListIterObject *)self;
_PyObject_GC_UNTRACK(it);
Py_XDECREF(it->it_seq);
PyObject_GC_Del(it);
assert(Py_IS_TYPE(self, &PyListIter_Type));
_Py_FREELIST_FREE(list_iters, it, PyObject_GC_Del);
}
static int

2
Objects/object.c
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@ -923,6 +923,8 @@ _PyObject_ClearFreeLists(struct _Py_freelists *freelists, int is_finalization)
clear_freelist(&freelists->tuples[i], is_finalization, free_object);
}
clear_freelist(&freelists->lists, is_finalization, free_object);
clear_freelist(&freelists->list_iters, is_finalization, free_object);
clear_freelist(&freelists->tuple_iters, is_finalization, free_object);
clear_freelist(&freelists->dicts, is_finalization, free_object);
clear_freelist(&freelists->dictkeys, is_finalization, PyMem_Free);
clear_freelist(&freelists->slices, is_finalization, free_object);

8
Objects/tupleobject.c
View File

@ -993,7 +993,8 @@ tupleiter_dealloc(PyObject *self)
_PyTupleIterObject *it = _PyTupleIterObject_CAST(self);
_PyObject_GC_UNTRACK(it);
Py_XDECREF(it->it_seq);
PyObject_GC_Del(it);
assert(Py_IS_TYPE(self, &PyTupleIter_Type));
_Py_FREELIST_FREE(tuple_iters, it, PyObject_GC_Del);
}
static int
@ -1119,15 +1120,16 @@ PyTypeObject PyTupleIter_Type = {
static PyObject *
tuple_iter(PyObject *seq)
{
_PyTupleIterObject *it;
if (!PyTuple_Check(seq)) {
PyErr_BadInternalCall();
return NULL;
}
_PyTupleIterObject *it = _Py_FREELIST_POP(_PyTupleIterObject, tuple_iters);
if (it == NULL) {
it = PyObject_GC_New(_PyTupleIterObject, &PyTupleIter_Type);
if (it == NULL)
return NULL;
}
it->it_index = 0;
it->it_seq = (PyTupleObject *)Py_NewRef(seq);
_PyObject_GC_TRACK(it);