.NET中的高分辨率计时器

Question

我想对我的代码进行一些基本的分析,但发现C#中的DateTime.Now只有大约16毫秒的分辨率.必须有更好的时间保留我尚未找到的构造.

Answer 1

以下是为操作计时的示例代码:

Dim sw As New Stopwatch()
sw.Start()
//Insert Code To Time
sw.Stop()
Dim ms As Long = sw.ElapsedMilliseconds
Console.WriteLine("Total Seconds Elapsed: " & ms / 1000)

编辑:

而整洁的事情是它也可以恢复.

Stopwatch sw = new Stopwatch();
foreach(MyStuff stuff in _listOfMyStuff)
{
    sw.Start();
    stuff.DoCoolCalculation();
    sw.Stop();
}
Console.WriteLine("Total calculation time: {0}", sw.Elapsed);

如果您的系统上有一个高分辨率计数器,System.Diagnostics.Stopwatch类将使用它.

Answer 2

System.Diagnostics.StopWatch类非常适合分析.

如果您不想编写自己的测量功能,可以链接到Vance Morrison的代码计时器博客.

Answer 3

对于最高分辨率性能计数器,您可以使用基础win32性能计数器.

添加以下P/Invoke sigs:

[System.Runtime.InteropServices.DllImport("Kernel32.dll")]
public static extern bool QueryPerformanceCounter(out long perfcount);

[System.Runtime.InteropServices.DllImport("Kernel32.dll")]
public static extern bool QueryPerformanceFrequency(out long freq);

并使用以下方式调用它

#region Query Performance Counter
/// <summary>
/// Gets the current 'Ticks' on the performance counter
/// </summary>
/// <returns>Long indicating the number of ticks on the performance counter</returns>
public static long QueryPerformanceCounter()
{
    long perfcount;
    QueryPerformanceCounter(out perfcount);
    return perfcount;
}
#endregion

#region Query Performance Frequency
/// <summary>
/// Gets the number of performance counter ticks that occur every second
/// </summary>
/// <returns>The number of performance counter ticks that occur every second</returns>
public static long QueryPerformanceFrequency()
{
    long freq;
    QueryPerformanceFrequency(out freq);
    return freq;
}
#endregion

把它全部转移到一个简单的课堂上,你准备好了.示例(假设PerformanceCounters的类名称):

long startCount = PerformanceCounter.QueryPerformanceCounter();
// DoStuff();
long stopCount = PerformanceCounter.QueryPerformanceCounter();
long elapsedCount = stopCount - startCount;
double elapsedSeconds = (double)elapsedCount / PerformanceCounter.QueryPerformanceFrequency();
MessageBox.Show(String.Format("Took {0} Seconds", Math.Round(elapsedSeconds, 6).ToString()));