gh-120198: Stop the world when setting __class__ on free-threaded build (GH-120672)

This commit is contained in:
Ken Jin 2024-07-11 02:02:08 +08:00 committed by GitHub
parent a802277914
commit 3bfc9c831a
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GPG Key ID: B5690EEEBB952194
5 changed files with 65 additions and 58 deletions

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@ -322,6 +322,8 @@ _PyInlineValuesSize(PyTypeObject *tp)
int
_PyDict_DetachFromObject(PyDictObject *dict, PyObject *obj);
PyDictObject *_PyObject_MaterializeManagedDict_LockHeld(PyObject *);
#ifdef __cplusplus
}
#endif

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@ -249,11 +249,7 @@ PyAPI_FUNC(PyTypeObject*) Py_TYPE(PyObject *ob);
#else
static inline PyTypeObject* _Py_TYPE(PyObject *ob)
{
#if defined(Py_GIL_DISABLED)
return (PyTypeObject *)_Py_atomic_load_ptr_relaxed(&ob->ob_type);
#else
return ob->ob_type;
#endif
}
#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 < 0x030b0000
# define Py_TYPE(ob) _Py_TYPE(_PyObject_CAST(ob))
@ -284,11 +280,7 @@ static inline int Py_IS_TYPE(PyObject *ob, PyTypeObject *type) {
static inline void Py_SET_TYPE(PyObject *ob, PyTypeObject *type) {
#ifdef Py_GIL_DISABLED
_Py_atomic_store_ptr(&ob->ob_type, type);
#else
ob->ob_type = type;
#endif
}
#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 < 0x030b0000
# define Py_SET_TYPE(ob, type) Py_SET_TYPE(_PyObject_CAST(ob), type)

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@ -106,7 +106,7 @@ class TestType(TestCase):
thing = Foo()
def work():
foo = thing
for _ in range(10000):
for _ in range(5000):
foo.__class__ = Bar
type(foo)
foo.__class__ = Foo

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@ -158,6 +158,10 @@ ASSERT_DICT_LOCKED(PyObject *op)
if (!_PyInterpreterState_GET()->stoptheworld.world_stopped) { \
ASSERT_DICT_LOCKED(op); \
}
#define ASSERT_WORLD_STOPPED_OR_OBJ_LOCKED(op) \
if (!_PyInterpreterState_GET()->stoptheworld.world_stopped) { \
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(op); \
}
#define IS_DICT_SHARED(mp) _PyObject_GC_IS_SHARED(mp)
#define SET_DICT_SHARED(mp) _PyObject_GC_SET_SHARED(mp)
@ -227,6 +231,7 @@ static inline void split_keys_entry_added(PyDictKeysObject *keys)
#define ASSERT_DICT_LOCKED(op)
#define ASSERT_WORLD_STOPPED_OR_DICT_LOCKED(op)
#define ASSERT_WORLD_STOPPED_OR_OBJ_LOCKED(op)
#define LOCK_KEYS(keys)
#define UNLOCK_KEYS(keys)
#define ASSERT_KEYS_LOCKED(keys)
@ -6667,10 +6672,10 @@ make_dict_from_instance_attributes(PyInterpreterState *interp,
return res;
}
static PyDictObject *
materialize_managed_dict_lock_held(PyObject *obj)
PyDictObject *
_PyObject_MaterializeManagedDict_LockHeld(PyObject *obj)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(obj);
ASSERT_WORLD_STOPPED_OR_OBJ_LOCKED(obj);
PyDictValues *values = _PyObject_InlineValues(obj);
PyInterpreterState *interp = _PyInterpreterState_GET();
@ -6699,7 +6704,7 @@ _PyObject_MaterializeManagedDict(PyObject *obj)
goto exit;
}
#endif
dict = materialize_managed_dict_lock_held(obj);
dict = _PyObject_MaterializeManagedDict_LockHeld(obj);
#ifdef Py_GIL_DISABLED
exit:
@ -7132,7 +7137,7 @@ PyObject_ClearManagedDict(PyObject *obj)
int
_PyDict_DetachFromObject(PyDictObject *mp, PyObject *obj)
{
_Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(obj);
ASSERT_WORLD_STOPPED_OR_OBJ_LOCKED(obj);
assert(_PyObject_ManagedDictPointer(obj)->dict == mp);
assert(_PyObject_InlineValuesConsistencyCheck(obj));

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@ -6540,28 +6540,11 @@ differs:
return 0;
}
static int
object_set_class(PyObject *self, PyObject *value, void *closure)
object_set_class_world_stopped(PyObject *self, PyTypeObject *newto)
{
if (value == NULL) {
PyErr_SetString(PyExc_TypeError,
"can't delete __class__ attribute");
return -1;
}
if (!PyType_Check(value)) {
PyErr_Format(PyExc_TypeError,
"__class__ must be set to a class, not '%s' object",
Py_TYPE(value)->tp_name);
return -1;
}
PyTypeObject *newto = (PyTypeObject *)value;
if (PySys_Audit("object.__setattr__", "OsO",
self, "__class__", value) < 0) {
return -1;
}
PyTypeObject *oldto = Py_TYPE(self);
/* In versions of CPython prior to 3.5, the code in
@ -6627,39 +6610,66 @@ object_set_class(PyObject *self, PyObject *value, void *closure)
/* Changing the class will change the implicit dict keys,
* so we must materialize the dictionary first. */
if (oldto->tp_flags & Py_TPFLAGS_INLINE_VALUES) {
PyDictObject *dict = _PyObject_MaterializeManagedDict(self);
PyDictObject *dict = _PyObject_GetManagedDict(self);
if (dict == NULL) {
return -1;
dict = _PyObject_MaterializeManagedDict_LockHeld(self);
if (dict == NULL) {
return -1;
}
}
bool error = false;
Py_BEGIN_CRITICAL_SECTION2(self, dict);
// If we raced after materialization and replaced the dict
// then the materialized dict should no longer have the
// inline values in which case detach is a nop.
assert(_PyObject_GetManagedDict(self) == dict ||
dict->ma_values != _PyObject_InlineValues(self));
assert(_PyObject_GetManagedDict(self) == dict);
if (_PyDict_DetachFromObject(dict, self) < 0) {
error = true;
}
Py_END_CRITICAL_SECTION2();
if (error) {
return -1;
}
}
if (newto->tp_flags & Py_TPFLAGS_HEAPTYPE) {
Py_INCREF(newto);
}
Py_BEGIN_CRITICAL_SECTION(self);
// The real Py_TYPE(self) (`oldto`) may have changed from
// underneath us in another thread, so we re-fetch it here.
oldto = Py_TYPE(self);
Py_SET_TYPE(self, newto);
Py_END_CRITICAL_SECTION();
return 0;
}
else {
return -1;
}
}
static int
object_set_class(PyObject *self, PyObject *value, void *closure)
{
if (value == NULL) {
PyErr_SetString(PyExc_TypeError,
"can't delete __class__ attribute");
return -1;
}
if (!PyType_Check(value)) {
PyErr_Format(PyExc_TypeError,
"__class__ must be set to a class, not '%s' object",
Py_TYPE(value)->tp_name);
return -1;
}
PyTypeObject *newto = (PyTypeObject *)value;
if (PySys_Audit("object.__setattr__", "OsO",
self, "__class__", value) < 0) {
return -1;
}
#ifdef Py_GIL_DISABLED
PyInterpreterState *interp = _PyInterpreterState_GET();
_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);
#endif
if (res == 0) {
if (oldto->tp_flags & Py_TPFLAGS_HEAPTYPE) {
Py_DECREF(oldto);
}
@ -6667,9 +6677,7 @@ object_set_class(PyObject *self, PyObject *value, void *closure)
RARE_EVENT_INC(set_class);
return 0;
}
else {
return -1;
}
return res;
}
static PyGetSetDef object_getsets[] = {