atomic queue operations

[Iain Hibbert <plunky%rya-online.net@localhost>]

On Fri, 25 Dec 2009, David Young wrote:

> On Fri, Dec 25, 2009 at 09:25:49AM +0000, Iain Hibbert wrote:
> > (somebody was working on atomic queues IIRC but I don't know how far along
> > that work is..)
>
> It's committed, but there is no manual page.  See sys/kern/subr_pcq.c.

Oh yes, I did know about that though its not immediately useful for this
case because of the fixed queue lengths..

besides, even with atomic queue operations some kind of mutex would still
be required because of the gap between checking that the queue is empty
and the sleep starting..

iain