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From: Robert Dewar <robert_dewar@my-deja.com>
Subject: Re: Ada Protected Object Tutorial #1
Date: 1999/12/27
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In article <848ajb$o39$1@nntp2.atl.mindspring.net>,
  Richard D Riehle <laoXhai@ix.netcom.com> wrote:
>  Protected objects represent a significant
> improvement over semaphores for mutual exclusion but need to
> be used sparingly in a multi-tasking design.  As your note
> implies, a protected object is not a substitute for a task.

I find this a type error :-)

Protected objects and semaphores are not the same kind of thing.

A semaphore is a particular synchronization mechanism with
advantages and disadvantages.

A protected object is a language mechanism for CREATING
synchrnonization mechanisms.

Indeed a very standard example of the use of protected types
is to implement a standard semaphore.


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