Re: gdb-ui can't handle mutiple debugging sessions

[Nick Roberts <nickrob@gnu.org>]

> Do multiple sessions still work (at least as well as before) if you use
> `gdb --fullname'?

gdb -fullname *should* work as before in all respects but I won't be able to
check anything for another couple of weeks.

> What's the source of difficulty in supporting multiple sesions with
gdb-ui?
> My experience in removing the "only one per Emacs process" limitation of
> various special modes (such as pcl-cvs) is that it's usually not that
hard,
> only it requires care (basically: make all the relevant variables
> buffer-local in the main buffer and be careful to always select the main
> buffer before reading those vars).

The original code (gdba.el) did have buffer-local variables although I'm
not sure that multiple sessions worked. Since the mode has multiple
windows/frames for a single session I decided it was best to make
the variables global for cleaner code. Given the difficulty that I've had
controlling the display of  the appropriate windows/frames just for
a single session, I still don't think that was a bad decision.

> In Emacs-21.3, the multiple-session support in gud.el is pretty fragile:
> it only works if all the GUD sessions use the same backend (i.e. all gdb,
> or all dbx, or all perldb).  That should be added to the TODO (which
should
> have a KNOWN-BUGS section).

How often would people need that kind of support?

gdb-ui needs feedback from a wider audience to find out which features are
important. Eventually it has to be replaced by a mode that uses GDB's
Machine Interface (MI) so it is really interim code.. When I started I just
didn't realise that a release would take so long.

Nick