[Xenomai-help] difference between "alarm_wait" and "task_wait_period"

[Xenomai-help] difference between "alarm_wait" and "task_wait_period"

[Mouaiad Alras]

Hello,
is there any difference between "periodic task" and "periodic alarm 
triggered task" ??

are "task1" and "task2" the same in this example ? :



void task1_do(void *cookies){
       while(1){
            rt_alarm_wait(&alarm1);
            ......
        }
}

int main(void){
    ......
    rt_alarm_create(&alarm1,"alarm1");
    rt_task_create(&task1,"task1",_STK,_PRIO,_MOD);
    rt_task_start(&task1, &task1_do, NULL);
    rt_alarm_start(&alarm1,_OFFSET,_INTERVAL);
    ......
}

===================================

void task2_do(void *cookies){
       while(1){
             rt_task_wait_period(&task2);
             ......
       }
}

int main(void){
    ......
    rt_task_create(&task2,"task2",_STK,_PRIO,_MOD);
    rt_task_set_periodic(&task2,_OFFSET,_INTERVAL);
    rt_task_start(&task2, &task2_do, NULL);
    ......
}




thank you,

Re: [Xenomai-help] difference between "alarm_wait" and "task_wait_period"

[Gilles Chanteperdrix]

Mouaiad Alras wrote:
 > Hello,
 > is there any difference between "periodic task" and "periodic alarm 
 > triggered task" ??
 > 
 > are "task1" and "task2" the same in this example ? :

No, these are two ways to do the same thing. A periodic task uses a
timer that is built-in the task, whereas an alarm creates a different
timer. Of course, you can create as many alarms as you want whereas each
task has only one built-in timer.

-- 


					    Gilles.