Re: [boost] boost.lockfree proposal

From: Tim Blechmann (tim_at_[hidden])
Date: 2008-04-29 18:31:30

>>  Compression is a good way to solve many ABA
>>  problems on architectures where CAS2 is not available. A compressing
>>  allocator/pointer pair would be required for any hope of portability.
>>  Of course, noncompressing version should be available for platofrm
>>  that could support it (such as Intel)
> 
> Yes, I actually combine the pointer and an ABA counter into one 64-bit
> value for legacy AMD systems that don't support CAS2.  I have only
> tested this on Windows - I have no idea how other OSes lay out their
> memory.  This also introduces the idea of "preparing" a pointer for CAS,
> though the algorithm code can still be generic enough for all archs.
> 
> http://svn.int64.org/svnroot/int64/snips/lockfree/tagged_ptr.x64.hpp

i have just implemented a compressed pointer for the x86_64 architecture, 
tested on one linux machine ...
http://tim.klingt.org/git?p=boost_lockfree.git;a=blob;f=boost/lockfree/
tagged_ptr_ptrcompression.hpp

cheers, tim

-- 
tim_at_[hidden]
http://tim.klingt.org
Silence is only frightening to people who are compulsively
verbalizing.
  William S. Burroughs