Re: ACL / Listener -> Hang (Carbon port)

[YAMAMOTO Mitsuharu]

>>>>> On Sun, 25 Jun 2006 17:46:39 +0100, David Reitter <address@hidden> said:

> Emacs hangs (no C-g possible) when "create new listener" from the
> Allegro Common Lisp package is selected - I can't verify /
> investigate further as I don't have Allegro Common Lisp. The package
> seems non-standard, but I don't see how an elisp package can legally
> bring Emacs to a halt (with C-g not working).

It's not difficult to do so.

  ;; Can't quit with C-g.  Send SIGFPE instead.
  (let ((inhibit-quit t))
    (while t))

And the info entry for with-local-quit says there are several places
where inhibit-quit is bound to t.

     This macro is mainly useful in functions that can be called from
     timers, process filters, process sentinels, `pre-command-hook',
     `post-command-hook', and other places where `inhibit-quit' is
     normally bound to `t'.

I'm not sure this is the cause of the unresponsiveness, though.

> The version he is using is a patched GNU Emacs CVS derviate (CVS as
> of 2006-04-10), Carbon port, running on an Intel Mac with OS X.  I
> don't believe any of the extensions to GNU Emacs present in his
> build can account for the hang this user is seeing.

The next thing to do for debugging would be identifying
situations/platforms where the problem occurs.

  * Identifying situations:
    - Try sending SIGFPE.  Hopefully we get Lisp-level backtrace.
    - Try debugging with GDB using hints in etc/DEBUG.

  * Identifying platforms:
    - Try X11 version.
    - Try Carbon version without any modifications.

                                     YAMAMOTO Mitsuharu
                                address@hidden