clock_abs_after
extern bool clock_abs_after(clockid_t, const struct timespec *);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_HIGHRES, &to);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_HIGHRES, &to);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_HIGHRES, &to);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_HIGHRES, &to);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_REALTIME, &to);
elapse = clock_abs_after(CLOCK_HIGHRES, &to);