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From: Robert Dewar <robert_dewar@my-deja.com>
Subject: Re: Caching & Annex C.6
Date: 1999/09/05
Message-ID: <7qss9f$a19$1@nnrp1.deja.com>#1/1
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Date: 1999-09-05T00:00:00+00:00
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In article <x7vyaenahw3.fsf@pogner.moho>,
  Simon Wright <simon@pogner.demon.co.uk> wrote:
> Are there (multi-processor, presumably) systems where you
would have
> to force a write-through to get the proper effect?

yes

 Do Ada
> implementations on such systems have to do that?

yes

The point is that for non-volatile objects, which you know
cannot be shared variables in the Ada sense, it is safe
to put them in cache, even if the cache is non-coherent,
but the point is that Volatile prevents this "optimization".

Machines with non-coherent caches always have a way of
signalling selected data as being non-cachable, forcing
access to a shared memory (well let's say, that's true
of shared memory machines).



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