https://github.com/python/cpython/commit/41090b7ba06f4b68249b825caf4d06560ed16d9c commit: 41090b7ba06f4b68249b825caf4d06560ed16d9c branch: 3.12 author: Miss Islington (bot) <[email protected]> committer: serhiy-storchaka <[email protected]> date: 2024-08-15T15:34:53Z summary:
[3.12] gh-112182: Replace StopIteration with RuntimeError for future (GH-113220) (GH-123033) When an `StopIteration` raises into `asyncio.Future`, this will cause a thread to hang. This commit address this by not raising an exception and silently transforming the `StopIteration` with a `RuntimeError`, which the caller can reconstruct from `fut.exception().__cause__` (cherry picked from commit 4826d52338396758b2d6790a498c2a06eec19a86) Co-authored-by: Jamie Phan <[email protected]> files: A Misc/NEWS.d/next/Library/2023-12-17-10-22-55.gh-issue-112182.jLWGlr.rst M Lib/asyncio/futures.py M Lib/test/test_asyncio/test_futures.py M Modules/_asynciomodule.c diff --git a/Lib/asyncio/futures.py b/Lib/asyncio/futures.py index 97fc4e3fcb60ee..fd486f02c67c8e 100644 --- a/Lib/asyncio/futures.py +++ b/Lib/asyncio/futures.py @@ -272,9 +272,13 @@ def set_exception(self, exception): raise exceptions.InvalidStateError(f'{self._state}: {self!r}') if isinstance(exception, type): exception = exception() - if type(exception) is StopIteration: - raise TypeError("StopIteration interacts badly with generators " - "and cannot be raised into a Future") + if isinstance(exception, StopIteration): + new_exc = RuntimeError("StopIteration interacts badly with " + "generators and cannot be raised into a " + "Future") + new_exc.__cause__ = exception + new_exc.__context__ = exception + exception = new_exc self._exception = exception self._exception_tb = exception.__traceback__ self._state = _FINISHED diff --git a/Lib/test/test_asyncio/test_futures.py b/Lib/test/test_asyncio/test_futures.py index 6fd7436450adf7..47daa0e9f410a8 100644 --- a/Lib/test/test_asyncio/test_futures.py +++ b/Lib/test/test_asyncio/test_futures.py @@ -270,10 +270,6 @@ def test_exception(self): f = self._new_future(loop=self.loop) self.assertRaises(asyncio.InvalidStateError, f.exception) - # StopIteration cannot be raised into a Future - CPython issue26221 - self.assertRaisesRegex(TypeError, "StopIteration .* cannot be raised", - f.set_exception, StopIteration) - f.set_exception(exc) self.assertFalse(f.cancelled()) self.assertTrue(f.done()) @@ -283,6 +279,25 @@ def test_exception(self): self.assertRaises(asyncio.InvalidStateError, f.set_exception, None) self.assertFalse(f.cancel()) + def test_stop_iteration_exception(self, stop_iteration_class=StopIteration): + exc = stop_iteration_class() + f = self._new_future(loop=self.loop) + f.set_exception(exc) + self.assertFalse(f.cancelled()) + self.assertTrue(f.done()) + self.assertRaises(RuntimeError, f.result) + exc = f.exception() + cause = exc.__cause__ + self.assertIsInstance(exc, RuntimeError) + self.assertRegex(str(exc), 'StopIteration .* cannot be raised') + self.assertIsInstance(cause, stop_iteration_class) + + def test_stop_iteration_subclass_exception(self): + class MyStopIteration(StopIteration): + pass + + self.test_stop_iteration_exception(MyStopIteration) + def test_exception_class(self): f = self._new_future(loop=self.loop) f.set_exception(RuntimeError) diff --git a/Misc/NEWS.d/next/Library/2023-12-17-10-22-55.gh-issue-112182.jLWGlr.rst b/Misc/NEWS.d/next/Library/2023-12-17-10-22-55.gh-issue-112182.jLWGlr.rst new file mode 100644 index 00000000000000..3d0fa98ee19055 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-12-17-10-22-55.gh-issue-112182.jLWGlr.rst @@ -0,0 +1,3 @@ +:meth:`!asyncio.futures.Future.set_exception()` now transforms :exc:`StopIteration` +into :exc:`RuntimeError` instead of hanging or other misbehavior. Patch +contributed by Jamie Phan. diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c index 1bf6b6e31c42a8..da44bb6b714578 100644 --- a/Modules/_asynciomodule.c +++ b/Modules/_asynciomodule.c @@ -594,12 +594,27 @@ future_set_exception(asyncio_state *state, FutureObj *fut, PyObject *exc) PyErr_SetString(PyExc_TypeError, "invalid exception object"); return NULL; } - if (Py_IS_TYPE(exc_val, (PyTypeObject *)PyExc_StopIteration)) { + if (PyErr_GivenExceptionMatches(exc_val, PyExc_StopIteration)) { + const char *msg = "StopIteration interacts badly with " + "generators and cannot be raised into a " + "Future"; + PyObject *message = PyUnicode_FromString(msg); + if (message == NULL) { + Py_DECREF(exc_val); + return NULL; + } + PyObject *err = PyObject_CallOneArg(PyExc_RuntimeError, message); + Py_DECREF(message); + if (err == NULL) { + Py_DECREF(exc_val); + return NULL; + } + assert(PyExceptionInstance_Check(err)); + + PyException_SetCause(err, Py_NewRef(exc_val)); + PyException_SetContext(err, Py_NewRef(exc_val)); Py_DECREF(exc_val); - PyErr_SetString(PyExc_TypeError, - "StopIteration interacts badly with generators " - "and cannot be raised into a Future"); - return NULL; + exc_val = err; } assert(!fut->fut_exception); _______________________________________________ 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]
