// returns result of function

static <A> A benchForNSeconds2(double n, S desc default str(f), IF0<A> f) {

  benchForNSeconds2(n, r { f! });

  ret f!;

}

// returns minimal time needed

// TODO: sub-second duration

static long benchForNSeconds2(S desc, Runnable r, double n, int innerRepetitions) {

  long start = sysNow(), min = -1, print = sysNow();

  int seconds = 1;

  while (seconds <= n) {

    long time = sysNow();

    for (int i = 0; i < innerRepetitions; i++)

      r.run();

    long now = sysNow();

    time = now-time;

    min = min < 0 ? time : min(min, time);

    if (now >= start+seconds*1000) {

      printAndSetConsoleTitle(min + " ms: " + desc + " (" + seconds + "/" + (n*(long) innerRepetitions) + " s, last=" + time + " ms)");

      ++seconds;

    }

  }

  ret min;

}