Wolfgang Grandegger wrote:
> Gilles Chanteperdrix wrote:
> > Wolfgang Grandegger wrote:
> > > Gilles Chanteperdrix wrote:
> > > > Gilles Chanteperdrix wrote:
> > > > > Wolfgang Grandegger wrote:
> > > > > > Hi Gilles,
> > > > > >
> > > > > > Gilles Chanteperdrix wrote:
> > > > > > > On Dec 6, 2007 3:05 PM, Wolfgang Grandegger <[EMAIL
> > PROTECTED]> wrote:
> > > > > > >> Gilles Chanteperdrix wrote:
> > > > > > >>> On Dec 6, 2007 2:28 PM, Gilles Chanteperdrix
> > > > > > >>> <[EMAIL PROTECTED]> wrote:
> > > > > > >>>> On Dec 6, 2007 2:24 PM, Wolfgang Grandegger <[EMAIL
> > PROTECTED]> wrote:
> > > > > > >>>>> Gilles Chanteperdrix wrote:
> > > > > > >>>>>> On Dec 6, 2007 1:31 PM, Wolfgang Grandegger <[EMAIL
> > PROTECTED]> wrote:
> > > > > > >>>>>>> Hello,
> > > > > > >>>>>>>
> > > > > > >>>>>>> how do I cancel or delete a Xenomai POSIX thread
> > running in primary
> > > > > > >>>>>>> context from a higher priority thread? IIUC,
> > pthread_kill() can only be
> > > > > > >>>>>>> used in secondary context. I tried pthread_cancel(),
> > but it only works
> > > > > > >>>>>>> when hitting a cancelation point, e.g.
> > pthread_testcancel(). Setting
> > > > > > >>>>>>> pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS) did
> > not help. Is
> > > > > > >>>>>>> there a code snippet or even an example program showing
> > how to cancel a
> > > > > > >>>>>>> pthread in primary context?
> > > > > > >>>>>> pthread_kill or pthread_cancel should result in sending
> > a signal to
> > > > > > >>>>>> the target thread, so should cause this thread to switch
> > to secondary
> > > > > > >>>>>> mode to handle it. If you want to wait for the target
> > thread to be
> > > > > > >>>>>> canceled, you should use pthread_cancel and pthread_join.
> > > > > > >>>>> There is no way to cancel a pthread in primary mode from
> > another pthread?
> > > > > > >>>> No. You always need secondary mode to effectively delete a
> > thread. The
> > > > > > >>>> same goes for the native skin.
> > > > > > >>> Ok. I understand what you mean. You want pthread_cancel not
> > to leave
> > > > > > >>> primary mode. This can easily be done by causing
> > pthread_cancel to use
> > > > > > >>> the kernel-space real-time pthread_cancel service. This
> > should work
> > > > > > >>> with no further modification.
> > > > > > >> I want to cancel/delete a task running in primary mode, e.g.
> > > > > > >>
> > > > > > >> void* work_task(void* dummy)
> > > > > > >> {
> > > > > > >> int count = 0;
> > > > > > >> while (1)
> > > > > > >> count++;
> > > > > > >> }
> > > > > > >>
> > > > > > >> from the outside (= another higher priority task). How can I
> > use the
> > > > > > >> kernel-space real-time pthread_cancel service? My POSIX app
> > is runs in
> > > > > > >> user-land.
> > > > > > >
> > > > > > > I was thinking about adding a pthread_cancel syscall that
> > would have
> > > > > > > triggered the kernel-space pthread_cancel. But this will not
> > work:
> > > > > > > user-space cleanup handlers would no longer get executed.
> > However,
> > > > > > > this can work for pthread_kill. Here is a patch which adds the
> > > > > > > pthread_kill syscall.
> > > > > >
> > > > > > Great, thanks a lot. This seems to work but I'm now fiddling
> > with proper
> > > > > > cleanup and exit. I have attached my small test program. It
> > behaves
> > > > > > somehow strange, at least to me:
> > > > > >
> > > > > > - I see task period overruns when the low prio task is started.
> > I
> > > > > > suspect some switch to secondary mode in init_task().
> > > > > >
> > > > > > - The program/system hangs after the listed messages:
> > > > > >
> > > > > > # ./kill_pthread
> > > > > > Starting high_prio_task
> > > > > > Killed low_prio task: count=3813129, overruns=0
> > > > > >
> > > > > > Any idea what I'm doing wrong?
> > > > > >
> > > > > > This is with Linux 2.4.25 and Xenomai 2.3.x on a MPC5200 board.
> > > > >
> > > > > Your test runs fine with Xenomai trunk (on ARM). I will now try
> > with
> > > > > current state of the v2.3.x branch.
> > > >
> > > > Works with v2.3.x too.
> > >
> > > I re-activated my test PC running Linux 2.6.20.21. with Xenomai 2.3.x.
> > > There the program runs fine _without_ your pthread_kill patch. For some
> > > reason the low_prio_task() is running in secondary mode (do you know
> > > why? Is there a function to check the mode?). I added
> > >
> > > struct sched_param param = { .sched_priority = LOW_PRIO };
> > > pthread_setschedparam(pthread_self(), SCHED_FIFO, ¶m);
>
> After adding pthread_getschedparam() I realized, that policy was 1 and
> prio 10 and not as expected 5. The corresponding attribute settings
> before calling pthread_create have been ignored somehow. Am I doing
> something wrong in task_init()?
No, I think there is rather something wrong in Xenomai user-space
library. __pthread_trampoline should call __wrap_pthread_setschedparam
instead of __real_pthread_setschedparam.
--
Gilles Chanteperdrix.
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