Re: [boost] Re: [shared_ptr] PPC implementations updated

From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-04-08 13:42:24

Alexander Terekhov wrote:
> Alexander Terekhov wrote:
>>
>> Peter Dimov wrote:
>> [...]
>>> I don't know, but all of Apple's code specifically clears the
>>> reservation. ;-)
>>
>> It doesn't make (some) Apple's code less broken (msync wise) though.
>> ;-)
>
> Note also that
>
> http://sourceware.org/cgi-bin/cvsweb.cgi/libc/sysdeps/powerpc/bits/atomic.h?cvsroot=glibc
>
> doesn't seem to exhibit that paranoia (and supposedly runs just fine
> on the same hardware). I suggest that you uncommit the "fix".

It's good enough for 1.33. A failed lock() is still expensive because I 
haven't fixed the upper layers to not throw bad_weak_ptr.

It might be good enough anyway... it's only two more instructions, after 
all. stwcx. is uncontended on zero. The paranoia is cheap in this specific 
case. :-)