Re: [boost] Nonlocking data structures.

From: Patrick Twohig (p-twohig_at_[hidden])
Date: 2008-04-17 18:45:46

Are you running it on a multicore machine or single core?  That radically
changes things.  I was having the same problem.  To test I ran 500 threads
or so a third of them were producers.  My suspicion was that I wasn't
enforcing the proper memory barriers because for x86 I had to write my own
CAS in assembly.

On Thu, Apr 17, 2008 at 3:23 PM, Michael Dickey <mike_at_[hidden]> wrote:

> I wrote a C++ lock free queue implementation recently based on the
> Michael & Scott algorithm, that uses APR's atomics.  It's available at:
>
>
> http://svn.atomiclabs.com/pion-common/trunk/common/include/pion/PionLockFreeQueue.hpp
>
> You're welcome to use it but you should be aware that it's not quite
> debugged yet.  It has issues when I tried using more than 1 producer
> and 1 consumer thread.  I wasn't sure if this was a mistake I made in
> the code, or a limitation of the algorithm, but I assume it's the
> former.  Anyway, in the end I decided not to use the code for what I
> was working on...  But if you can find and fix the bug, it's all
> yours!  =)
>
> Of course, it depends on APR's atomics..  Boost does not have any
> compare-and-swap abstraction as I far as I know, which seems to be a
> basic requirement for any lock-free programming.  Or maybe it does and
> I just don't know?
>
> Take care,
> -Mike
>
>
> On Apr 17, 2008, at 12:57 PM, Cory Nelson wrote:
> > On Wed, Apr 16, 2008 at 9:58 PM, Patrick Twohig <p-twohig_at_[hidden]>
> > wrote:
> >> I've been looking through the docs and I was wondering if boost has
> >> any
> >> lock-free threadsafe containers.  I know it's been brought up on
> >> the list
> >> before, but I was curious if anybody had a working implementation.
> >> If
> >> somebody is working on them, I'd like to lend a hand if possible.
> >
> > I have some lock-free stack/queue code for x86/x64/ia64 in c++.  It
> > only works with vc++ 2008 intrinsics right now, and the x64 version is
> > dependant on the windows memory manager if used on older CPUs.  If
> > people are interested in boostifying and porting it, I suppose we
> > could do that.
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