Re: [boost] Re: shared_ptr on ppc?

From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-04-07 13:56:21

Miro Jurisic wrote:
> In article <003c01c53b4c$1ec97680$6501a8c0_at_pdimov2>,
> "Peter Dimov" <pdimov_at_[hidden]> wrote:
>
>> 4. Apple has not documented the memory sychronization properties of
>> this API.
>
> If you give me a specific question to ask of Apple, I will work on
> getting the answer.

"What are the memory synchronization properties of the atomic primitives?" 
is one good question, but "Is there a specific reason for not encouraging 
the developers to use lwarx/stwcx. except memory visibility issues on a 
multiprocessor?" is a much better one.

FWIW,

http://www.opensource.apple.com/darwinsource/10.3/gccfast-1614/libjava/sysdep/powerpc/locks.h

uses lwarx/stwcx./sync/isync in a way that matches our understanding of how 
they are supposed to be used. There are other examples in Apple's own code, 
but opensource.apple.com wants me to register to see them. ;-)