https://github.com/python/cpython/commit/7b9d406729e7e7adc482b5b8c920de1874c... commit: 7b9d406729e7e7adc482b5b8c920de1874c234d0 branch: main author: Donghee Na <donghee.na@python.org> committer: corona10 <donghee.na92@gmail.com> date: 2024-02-01T08:58:08+09:00 summary: gh-112087: Make PyList_{Append,Size,GetSlice} to be thread-safe (gh-114651) files: M Include/internal/pycore_list.h M Include/object.h M Objects/listobject.c diff --git a/Include/internal/pycore_list.h b/Include/internal/pycore_list.h index 6c29d882335512..4536f90e414493 100644 --- a/Include/internal/pycore_list.h +++ b/Include/internal/pycore_list.h @@ -24,12 +24,13 @@ extern void _PyList_Fini(_PyFreeListState *); extern int _PyList_AppendTakeRefListResize(PyListObject *self, PyObject *newitem); +// In free-threaded build: self should be locked by the caller, if it should be thread-safe. static inline int _PyList_AppendTakeRef(PyListObject *self, PyObject *newitem) { assert(self != NULL && newitem != NULL); assert(PyList_Check(self)); - Py_ssize_t len = PyList_GET_SIZE(self); + Py_ssize_t len = Py_SIZE(self); Py_ssize_t allocated = self->allocated; assert((size_t)len + 1 < PY_SSIZE_T_MAX); if (allocated > len) { diff --git a/Include/object.h b/Include/object.h index ef3fb721c2b012..568d315d7606c4 100644 --- a/Include/object.h +++ b/Include/object.h @@ -428,7 +428,11 @@ static inline void Py_SET_TYPE(PyObject *ob, PyTypeObject *type) { static inline void Py_SET_SIZE(PyVarObject *ob, Py_ssize_t size) { assert(ob->ob_base.ob_type != &PyLong_Type); assert(ob->ob_base.ob_type != &PyBool_Type); +#ifdef Py_GIL_DISABLED + _Py_atomic_store_ssize_relaxed(&ob->ob_size, size); +#else ob->ob_size = size; +#endif } #if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 < 0x030b0000 # define Py_SET_SIZE(ob, size) Py_SET_SIZE(_PyVarObject_CAST(ob), (size)) diff --git a/Objects/listobject.c b/Objects/listobject.c index 56785e5f37a450..80a1f1da55b8bc 100644 --- a/Objects/listobject.c +++ b/Objects/listobject.c @@ -30,7 +30,6 @@ get_list_state(void) } #endif - /* Ensure ob_item has room for at least newsize elements, and set * ob_size to newsize. If newsize > ob_size on entry, the content * of the new slots at exit is undefined heap trash; it's the caller's @@ -221,8 +220,9 @@ PyList_Size(PyObject *op) PyErr_BadInternalCall(); return -1; } - else - return Py_SIZE(op); + else { + return PyList_GET_SIZE(op); + } } static inline int @@ -328,7 +328,7 @@ PyList_Insert(PyObject *op, Py_ssize_t where, PyObject *newitem) int _PyList_AppendTakeRefListResize(PyListObject *self, PyObject *newitem) { - Py_ssize_t len = PyList_GET_SIZE(self); + Py_ssize_t len = Py_SIZE(self); assert(self->allocated == -1 || self->allocated == len); if (list_resize(self, len + 1) < 0) { Py_DECREF(newitem); @@ -342,7 +342,11 @@ int PyList_Append(PyObject *op, PyObject *newitem) { if (PyList_Check(op) && (newitem != NULL)) { - return _PyList_AppendTakeRef((PyListObject *)op, Py_NewRef(newitem)); + int ret; + Py_BEGIN_CRITICAL_SECTION(op); + ret = _PyList_AppendTakeRef((PyListObject *)op, Py_NewRef(newitem)); + Py_END_CRITICAL_SECTION(); + return ret; } PyErr_BadInternalCall(); return -1; @@ -473,7 +477,7 @@ static PyObject * list_item(PyObject *aa, Py_ssize_t i) { PyListObject *a = (PyListObject *)aa; - if (!valid_index(i, Py_SIZE(a))) { + if (!valid_index(i, PyList_GET_SIZE(a))) { PyErr_SetObject(PyExc_IndexError, &_Py_STR(list_err)); return NULL; } @@ -511,6 +515,8 @@ PyList_GetSlice(PyObject *a, Py_ssize_t ilow, Py_ssize_t ihigh) PyErr_BadInternalCall(); return NULL; } + PyObject *ret; + Py_BEGIN_CRITICAL_SECTION(a); if (ilow < 0) { ilow = 0; } @@ -523,7 +529,9 @@ PyList_GetSlice(PyObject *a, Py_ssize_t ilow, Py_ssize_t ihigh) else if (ihigh > Py_SIZE(a)) { ihigh = Py_SIZE(a); } - return list_slice((PyListObject *)a, ilow, ihigh); + ret = list_slice((PyListObject *)a, ilow, ihigh); + Py_END_CRITICAL_SECTION(); + return ret; } static PyObject *