sclass MultiBencher {
  settable Runnable action;
  settable double seconds = 10;
  settable double interval = 0.001;
  double elapsedSeconds;
  
  new L<BenchForNSeconds> benchers;
  
  *() {}
  *(Runnable *action) {}
  
  run {
    ensureCapacity(benchers, iceilRatio(seconds, interval)+2);
    long start = nanoTime(), endTime = lround(start+secondsToNanos(seconds));
    while (nanoTime() < endTime) {
      var bencher = addAndReturn(benchers, new BenchForNSeconds(interval, action));
      bencher.run();
    }
  }
  
  long startTime() { ret empty(benchers) ? 0 : first(benchers).startTime; }
  
  S renderLegIndex(int i) {
    ret "Leg " + (i+1) + "/" + l(benchers)
      + " (T+" + n2(lround(nanosToMilliseconds(benchers.get(i).startTime-startTime()))) + " ms)";
  }
  
  toString {
    ret lines(mapWithIndex(benchers, (i, b)
      -> renderLegIndex(i) + ": " + b));
  }
  
  // "min records" are the times when a new minimum iteration time is reached
  S renderMinRecords(double threshold default 0.95) {
    new LS lines;
    long best = 0;
    for i, b over benchers: {
      long time = lround(b.min());
      if (i == 0) {
        best = time; 
        lines.add("First leg: " + n2(time) + " ns");
      } else if (time < best*threshold) {
        best = time;
        lines.add("New best time in " + firstToLower(renderLegIndex(i)) + ": " + n2(time) + " ns");
      }
    }
    ret lines(lines);
  }
}