C# Class RTools.Util.HighResClock

WARNING: I don't have any particularly good way of verifying the accuracy of this class. The best I've done is in the TestSelf() which is to compare the measured duration to Sleep(), which is loose. Also, I haven't tested this on any other PCs. I understand that the high performance counter may not be available on all systems.

The "ticks" in this class DO correspond to ticks in DateTime and TimeSpan, except in the Frequency property which is explicitly the high performance counter frequency.

It's relatively expensive to read this clock, compared to DateTime.Now. Although it's only about 10us on a P4 1.4GHz, it's faster to use DateTime.Now.

This does a calibration to determine function call overhead time, which is a static field. This has a static constructor which calls Calibrate(). Calibrate() temporarily boosts the calling process and thread priority to avoid being affected by other processes/threads.

The duration calculations are adjusted by the function call overhead time calculated during Calibrate(), but Now, NowTicks, etc are not.

You can use this just like DateTime for timing durations: DateTime startTime = HighResClock.Now; // do something you want to time here TimeSpan duration = HighResClock.Now - startTime; Console.WriteLine("Duration: {0}ms", duration.TotalMilliseconds);

To compensate for the overhead in the high resolution clock reads, you can use the following: DateTime startTime = HighResClock.Now; // do something you want to time here TimeSpan duration = HighResClock.CalcTimeSpan(startTime); Console.WriteLine("Duration: {0}ms", duration.TotalMilliseconds);