From 4145c8380699f7af14ae15179e01652e25f0d102 Mon Sep 17 00:00:00 2001 From: Yury Selivanov Date: Sun, 9 Oct 2016 12:19:12 -0400 Subject: Issue #27972: Prohibit Tasks to await on themselves. --- Lib/asyncio/tasks.py | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) (limited to 'Lib/asyncio/tasks.py') diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py index f735b44dc01..14949d13407 100644 --- a/Lib/asyncio/tasks.py +++ b/Lib/asyncio/tasks.py @@ -241,7 +241,7 @@ class Task(futures.Future): result = coro.throw(exc) except StopIteration as exc: self.set_result(exc.value) - except futures.CancelledError as exc: + except futures.CancelledError: super().cancel() # I.e., Future.cancel(self). except Exception as exc: self.set_exception(exc) @@ -259,12 +259,19 @@ class Task(futures.Future): 'Task {!r} got Future {!r} attached to a ' 'different loop'.format(self, result))) elif blocking: - result._asyncio_future_blocking = False - result.add_done_callback(self._wakeup) - self._fut_waiter = result - if self._must_cancel: - if self._fut_waiter.cancel(): - self._must_cancel = False + if result is self: + self._loop.call_soon( + self._step, + RuntimeError( + 'Task cannot await on itself: {!r}'.format( + self))) + else: + result._asyncio_future_blocking = False + result.add_done_callback(self._wakeup) + self._fut_waiter = result + if self._must_cancel: + if self._fut_waiter.cancel(): + self._must_cancel = False else: self._loop.call_soon( self._step, -- cgit v1.2.3