code: public final void sample()
    {
      long count = _count.get();
      long lastCount = _lastAvgCount.getAndSet(count);
      long time = _time.get();
      long lastTime = _lastAvgTime.getAndSet(time);
  
      if (count == lastCount)
        _value = 0;
      else
        _value = _scale * (time - lastTime) / (double) (count - lastCount);
    }
docs: Return the probe's next sample.