[Xenomai-help] Problem with Aperiodic xenomai tasks

[mani bhatti <imranbashirbhatti@domain.hid>]

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HI 
I want to have two tasks in xenomai the pariodic task and the non pariodic tasks which is signalled by the pariodic task.The problem is that  if i make one thread pariodic and the other one non pariodic then the pariodic thread never runs after specific time period and only non pariodic thread appears .The code for tasks  is given below.I would be very thankful if please some one  figure out what wrong i am doing.Thanks

void zaehler1_task(void *cookie){
        int ret;
    ret = rt_task_set_periodic(NULL, TM_NOW,                     rt_timer_ns2ticks(task_period_ns1));
        if (ret) {
                printf("error while set periodic, code %d\n",ret);
                 return;
        }
        while(!end){
                ret = rt_task_set_mode(0, T_RRB, NULL);
                if (ret) {
                        printf("error while rt_task_set_mode, code %d\n",ret);
                        return;
                }
                ret =  rt_task_wait_period();
                printf("T1:Start\n");

                if (ret) {
                 printf("error while rt_task_wait_period, code %d\n",ret);
                  return;
                }
           rt_mutex_lock(&threadmutex,TM_INFINITE);
           count1++;
           printf("T1:Ende:%d\n", count1);
     
           if(count1==15)     
          {  rt_cond_signal(&cond); }  
            rt_mutex_unlock(&threadmutex);
          }
}
void zaehler2_task(void *cookie){
    int ret;    
    long ii;
    long jj;
    double a;
    while(!end){
             rt_mutex_lock(&threadmutex,TM_INFINITE);
             rt_cond_wait(&cond,&threadmutex,TM_INFINITE);
             printf("\t\tT2:Start\n");
              count2++;
             printf("\t\tT2:Ende:%d\n", count2++);
            rt_mutex_unlock(&threadmutex);
         }
}
int main(int argc, char *argv[]) {
    int err, ret;
    printf("start\n");
    // install signal handler
    signal(SIGTERM, clean_exit);    
    signal(SIGINT, clean_exit);    
    // start timer
    ret = rt_timer_start(TM_ONESHOT);
    switch (ret) {
        case 0:       printf("Mit dem Fahrrad nich inn ersten Wagen\n\n");
                      break;
        case -EBUSY:  printf("timer is running\n");
                      break;
        case -ENOSYS: printf("can't start timer\n");
                      return ret;
    }

    rt_cond_create(&cond,NULL);
        /* create zaehler1_task */
    err = rt_task_create(&zaehler1_task_ptr,"Zaehler_1",STACK_SIZE,STD_PRIO1,0);
    /* create zaehler2_task */
    err = rt_task_create(&zaehler2_task_ptr,"Zaehler_2",STACK_SIZE,STD_PRIO2,0);

    /* start zaehler1_task */
    err = rt_task_start(&zaehler1_task_ptr,&zaehler1_task,NULL);

    /* start zaehler2_task */
    err = rt_task_start(&zaehler2_task_ptr,&zaehler2_task,NULL);

    // wait for signal & return of signal handler
    pause();
    fflush(NULL);
    return 0;
}




Jan Kiszka <jan.kiszka@domain.hid> wrote: mani bhatti wrote:
> Thanks Jan for your reply
> Actually the semaphore and mutexes stuff you have referred to i have
> already grounds for them.The only problem i have is please some body
> tell me that i dont want to make a thread periodic i,e i dont want to
> call a thread after periodic time interval i wanted it to  make it
> aperiodic like threads in C++ are scheduled by scheduler byitself

This has nothing to do with C++, rather with the class library you are
used to.

> and sleep on waiting condition with out any specific time interval
> and wake  only when  signalled from  pariodic thread. I hope you
> understand my point.Thanks a lot .

Let's try it differently:

thread_a()
{
 rt_task_set_periodic(...);
 while (1) {
  rt_task_wait_period(NULL);
  /* do some work */
  if (I_should_trigger_thread_b)
   rt_sem_v(&sem);
 }
}

thread_b()
{
 while (1) {
  rt_sem_p(&sem, TM_INFINITE);
  /* so some other work */
 }
}

Again, read up what the services are exactly doing or you will be lost
once you have to modify things only slightly.

Jan



 		
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