Question

当我执行以下程序并查看性能计数器时，结果对我来说没有意义。当我期望~0.1或~100时，平均值为零，最小/最大值为~0.4。

我的问题是什么？

代码

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();
    }
}

效果计数器屏幕截图 Performance Counter Screenshot http://friendfeed-media.com/50028bb6a0016931a3af5122774b56f93741bb5c

Answer 1

System.Diagnostics API包含一个非常微妙的混乱源：System.Diagnostics'ticks'与DateTime或TimeSpan'ticks'不同！

如果您使用StopWatch.ElapsedTicks而不是StopWatch.Elapsed.Ticks，它应该有效。

documentation包含有关此内容的更多信息。

Answer 2

Mark Seemann解释了问题的混乱来源，但我想提供一些额外的信息。

如果您要设置AverageTimer32性能计数器而不是TimeSpan，则可以执行以下转换：

Stopwatch

Answer 3

这是一个旧帖子，但我想我会插话。微软的某个人告诉我，我不应该使用TimeSpan，StopWatch或DateTime时与Performance Counters合作。相反，他建议在我的项目中添加以下本机方法：

internal static class NativeMethods
{
    [DllImport("Kernel32.dll")]
    public static extern void QueryPerformanceCounter(ref long ticks); 
}

当递增计数器时，他建议这样做：

public void Foo()
{
    var beginTicks = 0L;

    var endTicks = 0L;

    NativeMethods.QueryPerformanceCounter(ref beginTicks);

    // Do stuff

    NativeMethods.QueryPerformanceCounter(ref endTicks);

    this.Counter.IncrementBy(endTicks - beginTicks);
    this.BaseCounter.Increment();
}

如何在System.Diagnostics.Stopwatch中使用AverageTimer32和AverageBase性能计数器？

3 个答案: