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From: Robb Nebbe <nebbe@iam.unibe.ch>
Subject: Re: Real OO
Date: 1996/05/06
Message-ID: <318DB1C9.2AA5@iam.unibe.ch>#1/1
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references: <Dqtz2D.AFH@world.std.com> <Dqyy07.529@assip.csasyd.oz>
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organization: Dept. of CS, University of Berne, Switzerland
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Date: 1996-05-06T00:00:00+00:00
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Don Harrison wrote:
> 
> Robert A Duff writes:
> 
> :Sorry I wasn't clear.  Yes, I understand the above.  My question was,
> :how does the person writing the Ziggy compiler/run-time system
> :*implement* this "simultaneous" locking of a and b?  At the machine-code
> :level, I mean?
> 
> There are others who could answer this better than I, but you would expect that
> locking would actually be sequential at the machine-code level. Could you use
> an OS call to exclude all other processes during locking and revoke that
> privilege when completed?
> 

If you read the information that Bertrand Meyer made available at
http://www.eiffel.com this particular question is glossed over (along with
a lot of other questions but it is only a draft). The problem is mentioned
as being hard and that it may not be implemented in the early versions.
Hopefully this will not turn out like system validity which was
sufficiently complicated that it was never implemented.

Robb Nebbe
nebbe@iam.unibe.ch