diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-10-10-14-47-13.gh-issue-125221.nfSQzT.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-10-10-14-47-13.gh-issue-125221.nfSQzT.rst new file mode 100644 index 00000000000..c79650c3a64 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-10-10-14-47-13.gh-issue-125221.nfSQzT.rst @@ -0,0 +1,2 @@ +Fix possible race condition when calling :meth:`~object.__reduce_ex__` for the +first time in the free threading build. diff --git a/Objects/object.c b/Objects/object.c index 27d06cc0812..4a4c5bf7d7f 100644 --- a/Objects/object.c +++ b/Objects/object.c @@ -2372,6 +2372,14 @@ _PyTypes_InitTypes(PyInterpreterState *interp) } } + // Cache __reduce__ from PyBaseObject_Type object + PyObject *baseobj_dict = _PyType_GetDict(&PyBaseObject_Type); + PyObject *baseobj_reduce = PyDict_GetItemWithError(baseobj_dict, &_Py_ID(__reduce__)); + if (baseobj_reduce == NULL && PyErr_Occurred()) { + return _PyStatus_ERR("Can't get __reduce__ from base object"); + } + _Py_INTERP_CACHED_OBJECT(interp, objreduce) = baseobj_reduce; + // Must be after static types are initialized if (_Py_initialize_generic(interp) < 0) { return _PyStatus_ERR("Can't initialize generic types"); diff --git a/Objects/typeobject.c b/Objects/typeobject.c index d90bb5825fd..6ca4406ec0e 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -7359,18 +7359,7 @@ static PyObject * object___reduce_ex___impl(PyObject *self, int protocol) /*[clinic end generated code: output=2e157766f6b50094 input=f326b43fb8a4c5ff]*/ { -#define objreduce \ - (_Py_INTERP_CACHED_OBJECT(_PyInterpreterState_GET(), objreduce)) - PyObject *reduce, *res; - - if (objreduce == NULL) { - PyObject *dict = lookup_tp_dict(&PyBaseObject_Type); - objreduce = PyDict_GetItemWithError(dict, &_Py_ID(__reduce__)); - if (objreduce == NULL && PyErr_Occurred()) { - return NULL; - } - } - + PyObject *reduce; if (PyObject_GetOptionalAttr(self, &_Py_ID(__reduce__), &reduce) < 0) { return NULL; } @@ -7384,10 +7373,12 @@ object___reduce_ex___impl(PyObject *self, int protocol) Py_DECREF(reduce); return NULL; } - override = (clsreduce != objreduce); + + PyInterpreterState *interp = _PyInterpreterState_GET(); + override = (clsreduce != _Py_INTERP_CACHED_OBJECT(interp, objreduce)); Py_DECREF(clsreduce); if (override) { - res = _PyObject_CallNoArgs(reduce); + PyObject *res = _PyObject_CallNoArgs(reduce); Py_DECREF(reduce); return res; } @@ -7396,7 +7387,6 @@ object___reduce_ex___impl(PyObject *self, int protocol) } return _common_reduce(self, protocol); -#undef objreduce } static PyObject *