Strange looping

Strange looping

[Lennart Borgman]

I have experience some strange looping in Emacs recently. I have
difficulties catching them, but with a recent build I was able to use
Emacs to see what happened.

I found no reason. I killed all visible buffers, but Emacs still
loops. There are no processes that I can see. I did not see anything
really suspect - except for an arg out or range during fontification.

I think I have seen the same problem with builds from 2010-03-21 and
2010-04-27. (This are my patched builds, though.)

Anyone has any good idea of how to catch this?

Re: Strange looping

[David Reitter]

On Apr 29, 2010, at 8:02 PM, Lennart Borgman wrote:

> I have experience some strange looping in Emacs recently. I have
> difficulties catching them, but with a recent build I was able to use
> Emacs to see what happened.

I have received reports of similar problems, where Emacs is stuck in a loop involving redisplays (breakable with C-g).  This is in relation to ispell, and it seems to be consistent, even though I haven't managed to reproduce it.  A (print 1) statement in a place before the looping command seems to prevent it, but not so direct triggering of redisplay, or inhibiting redisplay.

Could this be the same problem?

Re: Strange looping

[Ken Hori]

Perhaps GNU Emacs is in the process of gaining consciousness itself.

http://www.amazon.com/Am-Strange-Loop-Douglas-Hofstadter/dp/0465030793/


On Thu, Apr 29, 2010 at 5:02 PM, Lennart Borgman
<lennart.borgman@gmail.com> wrote:
> I have experience some strange looping in Emacs recently. I have
> difficulties catching them, but with a recent build I was able to use
> Emacs to see what happened.
>
> I found no reason. I killed all visible buffers, but Emacs still
> loops. There are no processes that I can see. I did not see anything
> really suspect - except for an arg out or range during fontification.
>
> I think I have seen the same problem with builds from 2010-03-21 and
> 2010-04-27. (This are my patched builds, though.)
>
> Anyone has any good idea of how to catch this?
>
>
>

Re: Strange looping

[Eli Zaretskii]

> From: Lennart Borgman <lennart.borgman@gmail.com>
> Date: Fri, 30 Apr 2010 02:02:37 +0200
> 
> I have experience some strange looping in Emacs recently. I have
> difficulties catching them, but with a recent build I was able to use
> Emacs to see what happened.
> 
> I found no reason. I killed all visible buffers, but Emacs still
> loops. There are no processes that I can see. I did not see anything
> really suspect - except for an arg out or range during fontification.
> 
> I think I have seen the same problem with builds from 2010-03-21 and
> 2010-04-27. (This are my patched builds, though.)
> 
> Anyone has any good idea of how to catch this?

When that happens, attach GDB to the runaway Emacs, and then use the
procedure described in etc/DEBUG under "If the symptom of the bug is
that Emacs fails to respond", to find out where it is looping.