Re: tasking in Ada and Annex D question

[mgk25@cl.cam.ac.uk (Markus Kuhn)]

In nabbasi@earthlink.net writes:
|> Since the native threads seem to give the behavior one would
|> expect, wouldn't make more sense that this become the
|> default when gnat is installed on Linux, and not the FSU one.

The Ada for Linux team people have recently discussed this and
decided to standardize on the native threads and to try and fix
the kernel to achieve Annex D compliance with the native linuxthreads.
Supporting both thread libraries would lead to a real maintenance
hazzle, because all precompiled shared libraries provided on top
of the GNAT RTS would have to be provided twice, once for linuxthreads
and once for FSU. The FSU threads are primarily there to achieve
formal Annex D compliance, which you can't currently do with
linuxthreads, and they are otherwise of very little practical
interest. They provide no concurrency when system calls block,
and they provide no parallelism on multiprocessor machines,
while the native linuxthreads do offer all this.

Markus

-- 
Markus G. Kuhn, Computer Laboratory, University of Cambridge, UK
Email: mkuhn at acm.org,  WWW: <http://www.cl.cam.ac.uk/~mgk25/>