Re: GUIs and Ada Tasking

[Simon Wright <simon@pogner.demon.co.uk>]

tmoran@bix.com (Tom Moran) writes:

> >believe Ada tasking cannot coexist with GUI thread
> You are aware of the way messages go to the thread of their Window and
> all that.  Ada tasking can run with the Windows GUI (see, eg, my
> Adtest example in the Claw demos at www.rrsoftware.com/clawdemo.htm)
> but it does take care.

(sorry, lost the original ..)

With X11R6 you can build the libraries (X, Xt) to be thread-aware, but
the only off-the-shelf versions I've seen haven't been built this way.

If the libraries aren't thread-aware, or you're using an earlier X11,
each task must use its own Display connection exclusively (there can
be more than one connection to the same physical screen, so the tasks
can contribute to the same picture, but it is not straightforward to
handle).

I don't know whether there are widget sets (Athena, Motif, Tk) in
thread-safe versions, though.

I put a Linux/GNAT/XFree86-3.2 summary, which might be some help, at
http://www.pogner.demon.co.uk/gnat-x-threads/

-- 
Simon Wright                        Work Email: simon.j.wright@gecm.com
GEC-Marconi Radar & Defence Systems            Voice: +44(0)1705-701778
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