Skip to content

gh-152235: Defer GC tracking in set.union and set.difference #152290

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
corona10 merged 2 commits into from
Jun 26, 2026
+35 −20
Merged

gh-152235: Defer GC tracking in set.union and set.difference #152290

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
18edd99
gh-152235: Defer GC tracking in set.union and set.difference
corona10 Jun 26, 2026
eae1642
Address code review
corona10 Jun 26, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core_and_Builtins/2026-06-26-23-09-34.gh-issue-152235.ArozdF.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Defer GC tracking in :meth:`set.union`, :meth:`set.difference` and
:meth:`set.__sub__`. Patch by Donghee Na.

@vstinner vstinner Jun 26, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

You may complete the Changelog entry of your previous PR.

@vstinner vstinner Jun 26, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Ah, the Docs/Docs CI doesn't like set.__sub__ reference:

/home/runner/work/cpython/cpython/Doc/build/NEWS:854: WARNING: py:meth reference target not found: set.__sub__ [ref.meth]

38 changes: 26 additions & 12 deletions Objects/setobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1577,6 +1577,21 @@ _PySet_Freeze(PyObject *set)
return Py_NewRef(set);
}

static PyObject *
set_copy_untracked_lock_held(PySetObject *so)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(so);
PyObject *copy = make_new_set_basetype_untracked(Py_TYPE(so), NULL);
if (copy == NULL) {
return NULL;
}
if (set_merge_lock_held((PySetObject *)copy, (PyObject *)so) < 0) {
Py_DECREF(copy);
return NULL;
}
return copy;
}

/*[clinic input]
@critical_section
set.copy
Expand All @@ -1589,14 +1604,9 @@ static PyObject *
set_copy_impl(PySetObject *so)
/*[clinic end generated code: output=c9223a1e1cc6b041 input=c169a4fbb8209257]*/
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(so);
PyObject *copy = make_new_set_basetype(Py_TYPE(so), NULL);
if (copy == NULL) {
return NULL;
}
if (set_merge_lock_held((PySetObject *)copy, (PyObject *)so) < 0) {
Py_DECREF(copy);
return NULL;
PyObject *copy = set_copy_untracked_lock_held(so);
if (copy != NULL) {
_PyObject_GC_TRACK(copy);
}
return copy;
}
Expand Down Expand Up @@ -1652,7 +1662,8 @@ set_union_impl(PySetObject *so, PyObject * const *others,
PyObject *other;
Py_ssize_t i;

result = (PySetObject *)set_copy((PyObject *)so, NULL);
result = (PySetObject *)make_new_set_basetype_untracked(Py_TYPE(so),
(PyObject *)so);
if (result == NULL)
return NULL;

Expand All @@ -1665,6 +1676,7 @@ set_union_impl(PySetObject *so, PyObject * const *others,
return NULL;
}
}
_PyObject_GC_TRACK(result);
return (PyObject *)result;
}

Expand Down Expand Up @@ -2059,7 +2071,7 @@ set_copy_and_difference(PySetObject *so, PyObject *other)
{
PyObject *result;

result = set_copy_impl(so);
result = set_copy_untracked_lock_held(so);

@vstinner vstinner Jun 26, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

You may rename set_copy_and_difference() to set_copy_and_difference_untracked(), and rename set_difference() to set_difference_untracked().

if (result == NULL)
return NULL;
if (set_difference_update_internal((PySetObject *) result, other) == 0)
Expand Down Expand Up @@ -2118,7 +2130,6 @@ set_difference(PySetObject *so, PyObject *other)
}
Py_DECREF(key);
}
_PyObject_GC_TRACK(result);
return result;
}

Expand All @@ -2142,7 +2153,6 @@ set_difference(PySetObject *so, PyObject *other)
}
Py_DECREF(key);
}
_PyObject_GC_TRACK(result);
return result;
}

Expand Down Expand Up @@ -2185,6 +2195,7 @@ set_difference_multi_impl(PySetObject *so, PyObject * const *others,
return NULL;
}
}
_PyObject_GC_TRACK(result);
return result;
}

Expand All @@ -2199,6 +2210,9 @@ set_sub(PyObject *self, PyObject *other)
Py_BEGIN_CRITICAL_SECTION2(so, other);
rv = set_difference(so, other);
Py_END_CRITICAL_SECTION2();
if (rv != NULL) {
_PyObject_GC_TRACK(rv);
}
return rv;
}

Expand Down
Loading