#include <signal.h>
#include <sys/time.h>
#include <stdio.h>

void handler( int sig)
{
  static struct timeval tp1, tp2;
  static count = 0;
  struct itimerval it = {};

  count++;
  gettimeofday(&tp2, NULL);
  printf("%d s, %d us\n", tp2.tv_sec, tp2.tv_usec);
  if (count == 100) {
    setitimer(ITIMER_REAL, & it, NULL);
  }
}

main()
{
  struct itimerval it = {};
  int i, j;

  signal(SIGALRM, handler);

  it.it_interval.tv_usec = 1000; 
  it.it_value.tv_usec = 1000; 

  i = setitimer(ITIMER_REAL, & it, NULL);
  printf("setitimer %d\n", i);

  do {
    j = sleep(2);
//    printf("Remaining %d\n", j);
  } while (j);

  it.it_value.tv_usec = 0; 
  i = setitimer(ITIMER_REAL, & it,NULL);
  printf("setitimer %d\n", i);
}