https://github.com/python/cpython/commit/20438820ffa359d2e7b8fbd5cfd8f30329314bc1 commit: 20438820ffa359d2e7b8fbd5cfd8f30329314bc1 branch: 3.14 author: Sam Gross <[email protected]> committer: colesbury <[email protected]> date: 2026-03-06T14:35:00-05:00 summary:
[3.14] gh-145566: Skip stop-the-world when reassigning `__class__` on newly created objects (gh-145567) (#145605) Co-authored-by: Sam Gross <[email protected]> files: A Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-19-10-56.gh-issue-145566.H4RupyYN.rst M Objects/typeobject.c diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-19-10-56.gh-issue-145566.H4RupyYN.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-19-10-56.gh-issue-145566.H4RupyYN.rst new file mode 100644 index 00000000000000..723b81ddc5f897 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-19-10-56.gh-issue-145566.H4RupyYN.rst @@ -0,0 +1,2 @@ +In the free threading build, skip the stop-the-world pause when reassigning +``__class__`` on a newly created object. diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 03d5cfa4ca5249..76886a18036854 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -7120,7 +7120,11 @@ object_set_class_world_stopped(PyObject *self, PyTypeObject *newto) assert(_PyObject_GetManagedDict(self) == dict); - if (_PyDict_DetachFromObject(dict, self) < 0) { + int err; + Py_BEGIN_CRITICAL_SECTION(dict); + err = _PyDict_DetachFromObject(dict, self); + Py_END_CRITICAL_SECTION(); + if (err < 0) { return -1; } @@ -7162,12 +7166,17 @@ object_set_class(PyObject *self, PyObject *value, void *closure) #ifdef Py_GIL_DISABLED PyInterpreterState *interp = _PyInterpreterState_GET(); - _PyEval_StopTheWorld(interp); + int unique = _PyObject_IsUniquelyReferenced(self); + if (!unique) { + _PyEval_StopTheWorld(interp); + } #endif PyTypeObject *oldto = Py_TYPE(self); int res = object_set_class_world_stopped(self, newto); #ifdef Py_GIL_DISABLED - _PyEval_StartTheWorld(interp); + if (!unique) { + _PyEval_StartTheWorld(interp); + } #endif if (res == 0) { if (oldto->tp_flags & Py_TPFLAGS_HEAPTYPE) { _______________________________________________ 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]
