Hi Gilles, Gilles Chanteperdrix wrote: > On Dec 6, 2007 3:05 PM, Wolfgang Grandegger wrote: >> Gilles Chanteperdrix wrote: >>> On Dec 6, 2007 2:28 PM, Gilles Chanteperdrix >>> wrote: >>>> On Dec 6, 2007 2:24 PM, Wolfgang Grandegger wrote: >>>>> Gilles Chanteperdrix wrote: >>>>>> On Dec 6, 2007 1:31 PM, Wolfgang Grandegger 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. TIA. Wolfgang.