Subj : Re: Challenge: Multithreading & Synchronization
To   : comp.programming.threads
From : Uenal Mutlu
Date : Sat May 21 2005 08:31 pm

"David Schwartz" wrote
>
> "Uenal Mutlu" wrote in message
>
> >>     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.

Show you your code first, so to see what exactly you mean.

.