Message 255719 - Python tracker

Message255719

Author	oconnor663
Recipients	gvanrossum, oconnor663, vstinner, yselivanov
Date	2015-12-02.15:37:25
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1449070645.76.0.674051861514.issue25779@psf.upfronthosting.co.za>
In-reply-to

Content
The following hangs at 100% CPU on Python 3.5, though not on Python 3.4: 1) Start an asyncio coroutine with run_until_complete(). 2) Inside the coroutine, enter an ExitStack using a with-statement. 3) Inside the with-statement, call ExitStack.enter_context() with a generator context manager. It doesn't matter what the generator yields. 4) After the enter_context() call, raise an exception. Here's an example script that does all of this and repros the hang: https://gist.github.com/oconnor663/483db2820bb5f877c9ed

Content

The following hangs at 100% CPU on Python 3.5, though not on Python 3.4:

1) Start an asyncio coroutine with run_until_complete().
2) Inside the coroutine, enter an ExitStack using a with-statement.
3) Inside the with-statement, call ExitStack.enter_context() with a generator context manager. It doesn't matter what the generator yields.
4) After the enter_context() call, raise an exception.

Here's an example script that does all of this and repros the hang: https://gist.github.com/oconnor663/483db2820bb5f877c9ed

History
Date	User	Action	Args
2015-12-02 15:37:25	oconnor663	set	recipients: + oconnor663, gvanrossum, vstinner, yselivanov
2015-12-02 15:37:25	oconnor663	set	messageid: <1449070645.76.0.674051861514.issue25779@psf.upfronthosting.co.za>
2015-12-02 15:37:25	oconnor663	link	issue25779 messages
2015-12-02 15:37:25	oconnor663	create