Subj : Re: A question about atomic_ptr
To   : comp.programming.threads
From : Alexander Terekhov
Date : Thu Apr 14 2005 07:54 pm


Alexander Terekhov wrote:
> 
> Chris Thomasson wrote:
> >
> > > Does it try to access (via stwcx) reclaimed memory or not?
> >
> > http://groups.google.ca/groups?hl=en&lr=&selm=7I0Ea.854894%24OV.808546%40rwcrnsc54
> 
> Grr. CAS64 aside for a moment, Joe says (in that "refcount in object"

It can go boom on LL/LR step too.

> thread) "... decrement refcount to zero, and then destroy object. If
> it's after the load locked, the reservation is lost." Reservation is
> lost, that for sure. However, store-conditional can raise all sorts
> of "bad" exceptions (if the EA is "not good" by that time) even if
> reservation is lost. It's implementation-defined on Power, IIRC.

Ok, Joe said that "It needs the virtual storage to always be valid so 
the load locked won't segfault."

Not sexy.

regards,
alexander.

.