Subj : Re: A question about atomic_ptr
To   : comp.programming.threads
From : Alexander Terekhov
Date : Wed Apr 13 2005 05:40 pm


Peter Dimov wrote:

[... weighted reference counting ...]

> The reason I believe that this scheme is not a gain is that it eliminates
> count increments at the expense of an additional integer in every pointer.

It does bring contention down a bit (at expense of extra space), 
but you still need (naked) atomic operation. Consider: (basic 
thread-safety)

  weighted_reference_counting_ptr w;

Thread A:

  weighted_reference_counting_ptr a(w);

Thread B:

  weighted_reference_counting_ptr b(w);

Both threads need to update w's weight, oder?

regards,
alexander.

.