cvs commit: src/sys/kern kern_umtx.c src/sys/sys umtx.h

[Julian Elischer]

On Mon, 31 Mar 2003, Nate Lawson wrote:

> On Mon, 31 Mar 2003, Jeff Roberson wrote:
> >   Added files:
> >     sys/kern             kern_umtx.c 
> >     sys/sys              umtx.h 
> >   Log:
> >    - Add an api for doing smp safe locks in userland.
> >    - umtx_lock() is defined as an inline in umtx.h.  It tries to do an
> >      uncontested acquire of a lock which falls back to the _umtx_lock()
> >      system-call if that fails.
> >    - umtx_unlock() is also an inline which falls back to _umtx_unlock() if the
> >      uncontested unlock fails.
> >    - Locks are keyed off of the thr_id_t of the currently running thread which
> >      is currently just the pointer to the 'struct thread' in kernel.
> >    - _umtx_lock() uses the proc pointer to synchronize access to blocked thread
> >      queues which are stored in the first blocked thread.
> >   
> >   Revision  Changes    Path
> >   1.1       +303 -0    src/sys/kern/kern_umtx.c (new)
> >   1.1       +87 -0     src/sys/sys/umtx.h (new)
> 
> It's great to be getting this.  Can you point me to a document indicating
> how this will be used by KSE?  Are we going to have "native threads"
> (thr), KSE, and pthreads?

We will have 3 threads schemes..
userland threads
thr threads.. Useable by the majority of threaded apps
KSE threads.. Useable by threaded apps that have thousands of threads

(i.e. KSE is a hybrid if userland and thr threads..)



Julian