Subj : Optimization to Jeffrey Richter's COptex (Windows)?
To   : comp.programming.threads
From : Luke Elliott
Date : Wed Jan 26 2005 05:41 am

Hi

I assume most people are familiar with Richter's COptex but if not 
here's some links:

http://www.microsoft.com/msj/0198/win320198.aspx
http://www.microsoft.com/msj/0198/win32textfigs.htm#fig2

I've been trying to work out why he's used InterlockedExchange() when 
setting the owning thread id. As far as I call tell it isn't required 
with a uni-processor. (I haven't fully convinced myself the interlocked 
is required on SMP but I think it probably is.)

I've tried removing the interlocked exchange of thread id (replaced with 
normal assignment) and unsurprisingly get a considerable performance 
boost. This was on a uni-processor machine running a stress testing app.

Anybody have any views? I'll happily explain a bit more why I think it 
isn't necessary on UP but I guess I'm hoping for similar convincing 
views so I don't have to try and put it into words...

Thanks

Luke Elliott.

.