[Xenomai-help] help on alarms..

[Prashanti Bedapudi]

Attached is a piece of code using alarms, but I am seeing some unexpected
behavior.  Any help will be appreciated.

in function main() the program behaves two different ways depending on where
I have the last printf()

1. It works fine and terminates as expected if I have it like this
        while(!quit_now)
           printf("quit_now = %d\n", quit_now);

2. It does not terminate if I have it this way. I know quit_now is set to 1,
since the last statement printed is 'quit_now is set to 1'.

        while(!quit_now);
        printf("quit_now = %d\n", quit_now);

thanks,
Shanti


#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <native/types.h>
#include <native/alarm.h>
#include <native/task.h>


#define ALARM_NAME  "dl_alarm2"
#define ALARM_TASK_NAME "dl_alarm_task"
#define ALARM_TIME 500000
#define ALARM_INTERVAL 250000
#define ALARM_TASK_PRIO  20

RT_ALARM dl_alarm;
RT_TASK alarm_task;
bool quit_now = 0;


void catch_signal(int sig)
{
        rt_alarm_stop(&dl_alarm);
        rt_alarm_delete(&dl_alarm);
        rt_task_delete(&alarm_task);
        exit(0);
}



static void alarm_handler(void *cookie)
{
        int i =0;

        printf("Inside alarm handler\n ");
        for(i = 0; i<100; i++){
                rt_alarm_wait(&dl_alarm);
                printf("i = %d\n",i);
        }

        quit_now = 1;
        printf("quit_now is set to %d\n",quit_now);
        return;
        
}

int main()
{
        int ret = 0;

        signal(SIGTERM, catch_signal);
    signal(SIGINT, catch_signal);

        ret = rt_alarm_create(&dl_alarm, ALARM_NAME) ;
        if (ret)
                printf("\ncannot create alarm %d\n", ret);
        
        ret =  rt_task_spawn(&alarm_task, ALARM_TASK_NAME, 0, ALARM_TASK_PRIO, 
0, &alarm_handler, NULL);
        if(ret)
                exit(0);

        rt_alarm_start(&dl_alarm, ALARM_TIME, ALARM_INTERVAL);
        

        while(!quit_now);
                printf("quit_now = %d\n",quit_now);


        rt_alarm_stop(&dl_alarm);
        rt_alarm_delete(&dl_alarm);
        rt_task_delete(&alarm_task);

        return 0;
}

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