Subj : Re: A question about atomic_ptr
To   : comp.programming.threads
From : Peter Dimov
Date : Sun Apr 17 2005 02:36 pm

Chris Thomasson wrote:
> // *** shared_ptr ***
>
>
> 1. *Add this to public section:
> -----------------
>
> void tricky_copy( shared_ptr &r )
> {
>  pn.tricky_copy( r.pn );
>  px = r.px;
> }

But how do you avoid the usual problem of a thread being preempted after 
pn.tricky_copy and before px = r.px? r.px may have been changed and no 
longer in sync with the old r.pn.

.