diff options
| -rw-r--r-- | Lib/test/test_exceptions.py | 62 | ||||
| -rw-r--r-- | Misc/NEWS | 3 | ||||
| -rw-r--r-- | Objects/genobject.c | 11 |
3 files changed, 76 insertions, 0 deletions
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py index f05d3c0..718d05c 100644 --- a/Lib/test/test_exceptions.py +++ b/Lib/test/test_exceptions.py @@ -608,6 +608,68 @@ class ExceptionTests(unittest.TestCase): gc_collect() self.assertEqual(sys.exc_info(), (None, None, None)) + def _check_generator_cleanup_exc_state(self, testfunc): + # Issue #12791: exception state is cleaned up as soon as a generator + # is closed (reference cycles are broken). + class MyException(Exception): + def __init__(self, obj): + self.obj = obj + class MyObj: + pass + + def raising_gen(): + try: + raise MyException(obj) + except MyException: + yield + + obj = MyObj() + wr = weakref.ref(obj) + g = raising_gen() + next(g) + testfunc(g) + g = obj = None + obj = wr() + self.assertIs(obj, None) + + def test_generator_throw_cleanup_exc_state(self): + def do_throw(g): + try: + g.throw(RuntimeError()) + except RuntimeError: + pass + self._check_generator_cleanup_exc_state(do_throw) + + def test_generator_close_cleanup_exc_state(self): + def do_close(g): + g.close() + self._check_generator_cleanup_exc_state(do_close) + + def test_generator_del_cleanup_exc_state(self): + def do_del(g): + g = None + self._check_generator_cleanup_exc_state(do_del) + + def test_generator_next_cleanup_exc_state(self): + def do_next(g): + try: + next(g) + except StopIteration: + pass + else: + self.fail("should have raised StopIteration") + self._check_generator_cleanup_exc_state(do_next) + + def test_generator_send_cleanup_exc_state(self): + def do_send(g): + try: + g.send(None) + except StopIteration: + pass + else: + self.fail("should have raised StopIteration") + self._check_generator_cleanup_exc_state(do_send) + def test_3114(self): # Bug #3114: in its destructor, MyObject retrieves a pointer to # obsolete and/or deallocated objects. @@ -10,6 +10,9 @@ What's New in Python 3.3 Alpha 1? Core and Builtins ----------------- +- Issue #12791: Break reference cycles early when a generator exits with + an exception. + - Issue #12773: Make __doc__ mutable on user-defined classes. - Issue #12766: Raise an ValueError when creating a class with a class variable diff --git a/Objects/genobject.c b/Objects/genobject.c index cb2980c..43d0335 100644 --- a/Objects/genobject.c +++ b/Objects/genobject.c @@ -100,6 +100,17 @@ gen_send_ex(PyGenObject *gen, PyObject *arg, int exc) if (!result || f->f_stacktop == NULL) { /* generator can't be rerun, so release the frame */ + /* first clean reference cycle through stored exception traceback */ + PyObject *t, *v, *tb; + t = f->f_exc_type; + v = f->f_exc_value; + tb = f->f_exc_traceback; + f->f_exc_type = NULL; + f->f_exc_value = NULL; + f->f_exc_traceback = NULL; + Py_XDECREF(t); + Py_XDECREF(v); + Py_XDECREF(tb); Py_DECREF(f); gen->gi_frame = NULL; } |