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Date: 16 Aug 93 20:06:26 GMT
From: emery@mitre-bedford.arpa  (David Emery)
Subject: Re: Language runtime requirements (was Re: DoD
Message-ID: <EMERY.93Aug16150626@goldfinger.mitre.org>
List-Id: <comp.lang.ada>

>But Unix/C has been using multi-tasking well for years.

Huh?  Unix systems run multiple processes, but these processes are
very heavyweight.  In particular, each Unix process has its own
address space.  This does NOT match the Ada model, where tasks can
share address space (e.g. two tasks using a common package.)  

The Unix community has been talking about true multitasking, e.g.
"threads" in Unix-speak, for several years now, and the POSIX 1003.4a
standard is still in ballot.  Part of the problem is getting a full
understanding of the effects of multitasking on C, and another part of
the problem is understanding the effects of multitasking on things
like the traditional POSIX.1 interface.

Some C programmers have been using threads packages for a while, but
not with anywhere near the semantic precision of Ada nor the
portability of Ada.

				dave