How to use AverageTimer32 and AverageBase performance counters with System.Diagnostics.Stopwatch?

Eric Schoonover picture Eric Schoonover · Oct 10, 2009 · Viewed 12k times · Source

When I execute the following program and look at the performance counter the results don't make sense to me. The average value is zero and the min/max values are ~0.4 when I would expect ~0.1 or ~100.

What is my problem?

Code

class Program
{
    const string CategoryName = "____Test Category";
    const string CounterName = "Average Operation Time";
    const string BaseCounterName = "Average Operation Time Base";

    static void Main(string[] args)
    {
        if (PerformanceCounterCategory.Exists(CategoryName))
            PerformanceCounterCategory.Delete(CategoryName);

        var counterDataCollection = new CounterCreationDataCollection();

        var avgOpTimeCounter = new CounterCreationData()
        {
            CounterName = CounterName,
            CounterHelp = "Average Operation Time Help",
            CounterType = PerformanceCounterType.AverageTimer32
        };
        counterDataCollection.Add(avgOpTimeCounter);

        var avgOpTimeBaseCounter = new CounterCreationData()
        {
            CounterName = BaseCounterName,
            CounterHelp = "Average Operation Time Base Help",
            CounterType = PerformanceCounterType.AverageBase
        };
        counterDataCollection.Add(avgOpTimeBaseCounter);

        PerformanceCounterCategory.Create(CategoryName, "Test Perf Counters", PerformanceCounterCategoryType.SingleInstance, counterDataCollection);

        var counter = new PerformanceCounter(CategoryName, CounterName, false);
        var baseCounter = new PerformanceCounter(CategoryName, BaseCounterName, false);

        for (int i = 0; i < 500; i++)
        {
            var sw = Stopwatch.StartNew();
            Thread.Sleep(100);
            sw.Stop();

            Console.WriteLine(string.Format("t({0}) ms({1})", sw.Elapsed.Ticks, sw.Elapsed.TotalMilliseconds));
            counter.IncrementBy(sw.Elapsed.Ticks);
            baseCounter.Increment();
        }

        Console.Read();
    }
}

Performance Counter Screenshot Performance Counter Screenshot http://friendfeed-media.com/50028bb6a0016931a3af5122774b56f93741bb5c

Answer

Mark Seemann picture Mark Seemann · Oct 10, 2009

The System.Diagnostics API contains a pretty subtle source of great confusion: System.Diagnostics 'ticks' are not the same as DateTime or TimeSpan 'ticks'!

If you use StopWatch.ElapsedTicks instead of StopWatch.Elapsed.Ticks, it should work.

The documentation contains more information about this.