/* kernel module */

static int device_state[100];

/*
  dummy function to add a controllable latency
*/
static void noop_loop(unsigned long num)
{
  int i, j;
  unsigned long num_c = num;
  
  for (j=0; j<num; j++) {
    for (i=0; i<(sizeof(device_state)/sizeof(device_state[0])); i++) {
      device_state[i] = num_c;
      num_c *= 3;
    }
  }
}

static long tw_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
  unsigned long long tw_enter, tw_leave;

  switch (cmd) {
    case TW_DEMO:
      local_irq_disable();
      tw_enter = rdtsc_ordered();
      
      noop_loop(arg);

      tw_leave = rdtsc_ordered();
      local_irq_enable();

      return tw_leave - tw_enter;
  }

  return -1;
}


/* user-space */
void demo_tw_ext(void)
{
  int ret, i;
  unsigned long counter = 0, cnt = 0;;

  pin_task_to(0);

  puts("[*] normal time window");
  for (i=1; i<=10; i++) {
    printf("[*] tw=>%d\n", ioctl(fd, TW_DEMO, 1));
  }

  while (1) {
    counter++;
    ret = ioctl(fd, TW_DEMO, 1);
    if (ret > 20000) {
      cnt++;
      printf("[+] [%u] tw=>%d, catch time window extension in %lu attempts\n", cnt, ret, counter);
      if (cnt >= 10)
        break;
    }
  }

  puts("[*] time window measure demo done\n");
}