Re: Kevent POSIX timers support.

Ulrich Drepper
2006-11-23T20:27:11Z

Evgeniy Polyakov wrote:
> +static int posix_kevent_init(void)
> +{
> + struct kevent_callbacks tc = {
> + .callback = &posix_kevent_callback,
> + .enqueue = &posix_kevent_enqueue,
> + .dequeue = &posix_kevent_dequeue};

How do we prevent that somebody tries to register a POSIX timer event
source with kevent_ctl(KEVENT_CTL_ADD)? This should only be possible
from sys_timer_create and nowhere else.

Can you add a parameter to kevent_enqueue indicating this is a call from
inside the kernel and then ignore certain enqueue callbacks?

> @@ -343,23 +439,27 @@ static int posix_timer_fn(struct hrtimer
>
> timr = container_of(timer, struct k_itimer, it.real.timer);
> spin_lock_irqsave(&timr->it_lock, flags);
> +
> + if (timr->it_sigev_notify & SIGEV_KEVENT) {
> + kevent_storage_ready(&timr->st, NULL, KEVENT_MASK_ALL);
> + } else {

We need to pass the data in the sigev_value meember of the struct
sigevent structure passed to timer_create to the caller. I don't see it
being done here nor when the timer is created. Do I miss something?
The sigev_value value should be stored in the user/ptr member of struct
ukevent.

> + if (event.sigev_notify & SIGEV_KEVENT) {

Don't use a bit. It makes no sense to combine SIGEV_SIGNAL with
SIGEV_KEVENT etc. Only SIGEV_THREAD_ID is a special case.

Just define SIGEV_KEVENT to 3 and replace the tests like the one cited
above with

if (timr->it_sigev_notify == SIGEV_KEVENT)

--
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖