[boost] Re: [shared_ptr] Interlocked* - possible bug?

John Torjo wrote:

Hi Peter,

I think there is a bug in your Interlocked* implementation of shared_ptr (http://www.pdimov.com/cpp/shared_count_x86_exp2.hpp).

In atomic_read you have: inline long atomic_read(long volatile const & value) { return value; }

I don't believe this is thread-safe.

(repost) On x86/IA32, I believe that it's as thread safe as you can get. Note that all count updates go through Interlocked* calls. On IA32, plain reads can only return a somewhat "surprising" value when interleaved with plain writes, and even then, the element of surprise is limited. ;-)