https://github.com/python/cpython/commit/8a162b2e270bc371f0c229e8511e7c19b3742f52 commit: 8a162b2e270bc371f0c229e8511e7c19b3742f52 branch: 3.15 author: Miss Islington (bot) <[email protected]> committer: kumaraditya303 <[email protected]> date: 2026-05-23T08:53:12Z summary:
[3.15] gh-148450: `abc.register` needs to update `type_version` when `tp_flags` is changed (GH-148623) (#150300) gh-148450: `abc.register` needs to update `type_version` when `tp_flags` is changed (GH-148623) (cherry picked from commit e7eaed56149aa08f7fd5012784cc1deef8e483de) Co-authored-by: Hai Zhu <[email protected]> files: A Misc/NEWS.d/next/Core_and_Builtins/2026-04-15-15-48-04.gh-issue-148450.2MEVqH.rst M Lib/test/test_type_cache.py M Objects/typeobject.c diff --git a/Lib/test/test_type_cache.py b/Lib/test/test_type_cache.py index 22ad9f6243eda91..849a2afd8ed7986 100644 --- a/Lib/test/test_type_cache.py +++ b/Lib/test/test_type_cache.py @@ -1,4 +1,5 @@ """ Tests for the internal type cache in CPython. """ +import collections.abc import dis import unittest import warnings @@ -114,6 +115,25 @@ class HolderSub(Holder): Holder.set_value() HolderSub.value + def test_abc_register_invalidates_subclass_versions(self): + class Parent: + pass + + class Child(Parent): + pass + + type_assign_version(Parent) + type_assign_version(Child) + parent_version = type_get_version(Parent) + child_version = type_get_version(Child) + if parent_version == 0 or child_version == 0: + self.skipTest("Could not assign valid type versions") + + collections.abc.Mapping.register(Parent) + + self.assertEqual(type_get_version(Parent), 0) + self.assertEqual(type_get_version(Child), 0) + @support.cpython_only class TypeCacheWithSpecializationTests(unittest.TestCase): def tearDown(self): diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-04-15-15-48-04.gh-issue-148450.2MEVqH.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-04-15-15-48-04.gh-issue-148450.2MEVqH.rst new file mode 100644 index 000000000000000..2a7d0d9bb3a7f7e --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-04-15-15-48-04.gh-issue-148450.2MEVqH.rst @@ -0,0 +1 @@ +Fix ``abc.register()`` so it invalidates type version tags for registered classes. diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 7cca137f74be58f..fc679ef747e8567 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -6490,9 +6490,25 @@ set_flags_recursive(PyTypeObject *self, unsigned long mask, unsigned long flags) void _PyType_SetFlagsRecursive(PyTypeObject *self, unsigned long mask, unsigned long flags) { + BEGIN_TYPE_LOCK(); + /* Ideally, changing flags and invalidating the old version tag would + happen in one step. But type_modified_unlocked() is re-entrant and + cannot run with the world stopped, so we must invalidate first. + Immutable/static-builtin types are skipped because + set_flags_recursive() does not modify them. */ + if (!PyType_HasFeature(self, Py_TPFLAGS_IMMUTABLETYPE) && + (self->tp_flags & mask) != flags) + { + type_modified_unlocked(self); + } + /* Keep TYPE_LOCK held while waiting for stop-the-world so no thread + can reassign a version tag before the flag update. */ + type_lock_prevent_release(); types_stop_world(); set_flags_recursive(self, mask, flags); types_start_world(); + type_lock_allow_release(); + END_TYPE_LOCK(); } /* This is similar to PyObject_GenericGetAttr(), _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
