Re: [Xenomai-help] Problems with rt_task_wait_period

[Philippe Gerum <rpm@xenomai.org>]

On Mon, 2006-08-07 at 16:17 +0200, Jan Kiszka wrote:
> Philippe Gerum wrote:
> > On Mon, 2006-08-07 at 15:45 +0200, Jan Kiszka wrote:
> >> Steve Kreyer wrote:
> >>> Hi,
> >>>
> >>> Iam new to xenomai. 
> >>> For warming up I try to run this little test program:
> >>>
> >>> -----------------------------------------------------------------------
> >>> #include <native/task.h>
> >>> #include <stdio.h>
> >>> #include <sys/mman.h>
> >>>
> >>> RT_TASK task1;
> >>>
> >>> void rt_task1(void* user_data){
> >>>     int err = 0;
> >>>     printf("%d\n", rt_task_set_periodic(NULL, TM_NOW, 100));
> >> You are running in one-shot mode, thus all time units are in
> >> *nanoseconds*. 100 ns cycles tend to pass quite quickly, thus the setup
> >> actually fails (but it doesn't report this - a corner case for
> >> considering this a bug).
> > 
> > The setup does not really fail, but the period is so short that the tick
> > occurs before the task has a chance to wait for the first release point
> > in the timeline, so rt_task_wait_period() notices that no timer is
> > outstanding, but incorrectly concludes that no timer was ever armed.
> 
> Mmh, wouldn't the box simply lock up if the setup succeeded? It's a
> periodic timer... :->

What I meant is that there is nothing in xnpod_set_thread_periodic()
that actually checks if the settings are valid in the idate ==
XN_INFINITE case, therefore the setup never formally fails.

> 
> Jan
> 
-- 
Philippe.