Re: Kevent POSIX timers support.

From: Ulrich Drepper
Date: Thu Nov 23 2006 - 15:27:29 EST


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)

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