4d2
Subj : Re: Challenge: Multithreading & Synchronization
To   : comp.programming.threads
From : David Schwartz
Date : Sat May 21 2005 09:47 am


"Uenal Mutlu" <520001085531-0001@t-online.de> wrote in message 
news:d6mvo3$md$03$1@news.t-online.com...

>>     Show me in code how you wait for a condition variable without 
>> unsharing
>> it. By "unsharing it", I mean making it no longer shared in the CPU's 
>> cache.

> I've shown that already, see prev. posting.
> There is nothing special to do by the user about it. It is sufficient
> just to use the InterLockedXXX funcs to set and get the atomic variable.
> Requirements for a variable to be used by InterlockedXXX (on x86, MSVC 
> compiler),
> is that it must be volatile and right aligned, and of size of the natural 
> word size
> of the CPU: here 32 bit integer on 32 bit CPUs:
>
> // a right aligned 32 bit integer on x86 (MSVC code):
> #pragma pack(push, 4)
> volatile long lVar;
> #pragma pack(pop)
>
> Of course such things are best packed (hidden) inside a handy class in 
> C++.

    You still haven't answered my question. Show me the code that allows you 
to test the value of a shared atomic type without unsharing it.

    DS

.

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