Subj : Hazard pointer w/ extra memory barrier
To   : comp.programming.threads
From : Joe Seigh
Date : Tue May 10 2005 10:21 am

I think if you store into a hazard pointer that is not null
then you need release semantics on that store to prevent any
prior accesses from occurring after that store.

         load  global
         membar  load/store, store/store
         store hazard
         membar store/load
         load  global
         compare
         branch conditional

Ditto if you're just storing NULL into a non-NULL hazard pointer.

         membar  load/store, store/store
         store hazard

So that's an extra memory barrier to get rid off.  More fun.

-- 
Joe Seigh

When you get lemons, you make lemonade.
When you get hardware, you make software.

.