Fw: [patch] Make std::tr1::shared_ptr thread-safe.

[Paolo Carlini]

Alexander Terekhov wrote:

>On Apr 2, 2005 9:43 PM, Paolo Carlini <pcarlini@suse.de> wrote:
>[...]
>  
>
>>Therefore, I think we can safely say that Jonathan patch is OK, or at
>>least not worse, from the MT point of view than the rest of the library
>>    
>>
>Both are broken. Because your current __exchange_and_add() doesn't
>provide suffiecent msync semantics for basic thread-safety of refcounting 
>immutable objects.
>
Alexander... Which is the point of writing "broken" two or three times
per hour? Testcases are needed and concrete help too. Immanuel Kant
comes to my mind:

"Thoughts without content are empty, intuitions without concepts are
blind. It is therefore just as necessary to make our concepts sensible
that is to add the object to them in intuition as to make our intuitions
intelligible, that is to bring them under confunctions."

;)

Really, we *are* aware of the problem, we know that *on some* archs
exchange_and_add is worse than should be (still, as emphasized again by
Peter, nobody reported problems so far), we *are* going to improve it,
in due course, as soon as 4.0.0 is out and we can spend time on that
issue. Your help will be really welcome.

Paolo.