Re: [PATCH] vt: add an event interface

[Lennart Poettering <mzxreary@0pointer.de>]

On Thu, 02.07.09 12:36, Alan Cox (alan@lxorguk.ukuu.org.uk) wrote:

(Sorry for the long delay in responding, I have been travelling)

> Lennart how does this fit your needs - this replaces the existing wait
> active hack with a race free one and adds other events with a proper
> infrastructure for them.

Sounds good to me. Though tbh, in my eyes the "proper" fix for this
whole problem would be something which would enable userspace to
poll() for VT changes. Having blocking ioctl()s still requires most
userspace applications to spawn a thread for doing that since usually
they are not exclusively waiting for VT events, but also for dbus
requests or some other events.

But OTOH I guess 2 threads are still better than the old situation
requiring processes to run 64 threads for listening for VT changes.

Oh, and one more note: instead of padding the struct it would probably
be more future-proof to simply pass the struct size in addition to the
struct to the ioctl().

Lennart

> From: Alan Cox <alan@linux.intel.com>
> 
> This is needed and requested in various forms for ConsoleKit, screenblank
> handling and the like so do the job with a single interface. Also build the
> interface so that unlike VT_WAITACTIVE and friends it won't miss events.
> 
> Signed-off-by: Alan Cox <alan@linux.intel.com>

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/           GnuPG 0x1A015CC4