[lttng-dev] urcu stack and queues updates and documentation

[paulmck@linux.vnet.ibm.com (Paul E. McKenney)]

On Sun, Oct 14, 2012 at 01:53:32PM -0400, Mathieu Desnoyers wrote:
> Hi Paul!
> 
> I know you are currently looking at documentation of urcu data
> structures. I did quite a bit of work in that area these past days. Here
> is my plan:

Actually, I diverted to the atomic operations, given that the stack/queue
API seems to be in flux.  ;-)

> 1) I would like to deprecate, at some point, rculfqueue, wfqueue, and
>    rculfstack.
> 
> 2) For wfqueue, we replace it by wfcqueue, currently in the urcu master
>    branch.
> 
> 3) For rculfstack, we replace it by lfstack available here (volatile
>    branch):
> 
> git://git.dorsal.polymtl.ca/~compudj/userspace-rcu
> branch: urcu/lfstack

I probably have to document them to have any chance of having an opinion,
other than my usual advice to avoid disrupting users of the old interfaces.

> 4) I did documentation improvements (and implemented pop_all as well as
>    empty, and iterators) for wfstack here (volatile branch too):
> 
> git://git.dorsal.polymtl.ca/~compudj/userspace-rcu
> branch: urcu/wfstack

I will be very happy to take advantage of this.  ;-)

> 5) The last one to look into would be rculfqueue. I'd really like to
>    create a lfcqueue derived from wfcqueue if possible. It's the next
>    item on my todo list this weekend.

The piece I am missing is ABA avoidance.  Or is this the approach
that assumes a single dequeuer?

							Thanx, Paul

> Thoughts ?
> 
> Thanks,
> 
> Mathieu
> 
> -- 
> Mathieu Desnoyers
> Operating System Efficiency R&D Consultant
> EfficiOS Inc.
> http://www.efficios.com
>