对老赵写的简单性能计数器的修改

早上看到老赵写的这个性能计数器，感觉很实用，不过老赵用了很多.C# 3.0 的新语法，还用了 VISTA 和 Server 2008 下特有的Win32 API，对于还在用C#2.0 或者还工作在 XP 或者 Server 2003 下的兄弟们，只能望代码心叹了。应老赵的要求，我修改了他的代码，增加了对低版本C# 和低版本windows 操作系统的支持。

老赵的原文：一个简单的性能计数器：CodeTimer

修改说明

1. 采用接口取代了原代码中的 Lambda 表达式

2. 采用 GetThreadTimes 这个API 函数替代了原代码中的 QueryThreadCycleTime

这里需要说明的是 GetThreadTimes 给出了线程在内核态和用户态占用的时间，单位是 100 ns。两个时间的总和就是线程占用的CPU时间。这个API的时间精度我看了一些资料似乎没有达到 100ns. 所以GetThreadTimes 这个API函数的进度没有 QueryThreadCycleTime 高。

下面是我修改后的代码

注释1: 2009-03-11 增加委托的调用，修改 GC.Collect 参数，兼容.Net 2.0. 增加每次调用时间统计

增加了委托调用后，我发现同样是测试空函数，采用接口比采用委托效率要略高一些，这和我的预计基本吻合，因为委托不是单纯的函数调用，具体原理超出本文范围，我就不多说了。

using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.Threading;
using System.Runtime.InteropServices;
  
 
    public interface IAction
    {
        void Action();
    }

    public static class CodeTimer
    {
        [DllImport("kernel32.dll", SetLastError = true)]
        static extern bool GetThreadTimes(IntPtr hThread, out long lpCreationTime,
           out long lpExitTime, out long lpKernelTime, out long lpUserTime);

        [DllImport("kernel32.dll")]
        static extern IntPtr GetCurrentThread();

        public delegate void ActionDelegate();

        private static long GetCurrentThreadTimes()
        {
            long l;
            long kernelTime, userTimer;
            GetThreadTimes(GetCurrentThread(), out l, out l, out kernelTime, 
               out userTimer);
            return kernelTime + userTimer;
        }

        static CodeTimer()
        {
            Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;
            Thread.CurrentThread.Priority = ThreadPriority.Highest;

        }

        public static void Time(string name, int iteration, ActionDelegate action)
        {
            if (String.IsNullOrEmpty(name))
            {
                return;
            }

            if (action == null)
            {
                return;
            }

            //1. Print name
            ConsoleColor currentForeColor = Console.ForegroundColor;
            Console.ForegroundColor = ConsoleColor.Yellow;
            Console.WriteLine(name);


            // 2. Record the latest GC counts
            //GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced);
            GC.Collect(GC.MaxGeneration);
            int[] gcCounts = new int[GC.MaxGeneration + 1];
            for (int i = 0; i <= GC.MaxGeneration; i++)
            {
                gcCounts[i] = GC.CollectionCount(i);
            }

            // 3. Run action
            Stopwatch watch = new Stopwatch();
            watch.Start();
            long ticksFst = GetCurrentThreadTimes(); //100 nanosecond one tick

            for (int i = 0; i < iteration; i++) action();
            long ticks = GetCurrentThreadTimes() - ticksFst;
            watch.Stop();

            // 4. Print CPU
            Console.ForegroundColor = currentForeColor;
            Console.WriteLine("\tTime Elapsed:\t\t" + 
               watch.ElapsedMilliseconds.ToString("N0") + "ms");
            Console.WriteLine("\tTime Elapsed (one time):" + 
               (watch.ElapsedMilliseconds / iteration).ToString("N0") + "ms");

            Console.WriteLine("\tCPU time:\t\t" + (ticks * 100).ToString("N0") 
               + "ns");
            Console.WriteLine("\tCPU time (one time):\t" + (ticks * 100 / 
               iteration).ToString("N0") + "ns");

            // 5. Print GC
            for (int i = 0; i <= GC.MaxGeneration; i++)
            {
                int count = GC.CollectionCount(i) - gcCounts[i];
                Console.WriteLine("\tGen " + i + ": \t\t\t" + count);
            }

            Console.WriteLine();

        }

        public static void Time(string name, int iteration, IAction action)
        {
            if (String.IsNullOrEmpty(name))
            {
                return;
            }

            if (action == null)
            {
                return;
            }

            //1. Print name
            ConsoleColor currentForeColor = Console.ForegroundColor;
            Console.ForegroundColor = ConsoleColor.Yellow;
            Console.WriteLine(name);


            // 2. Record the latest GC counts
            //GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced);
            GC.Collect(GC.MaxGeneration);
            int[] gcCounts = new int[GC.MaxGeneration + 1];
            for (int i = 0; i <= GC.MaxGeneration; i++)
            {
                gcCounts[i] = GC.CollectionCount(i);
            }

            // 3. Run action
            Stopwatch watch = new Stopwatch();
            watch.Start();
            long ticksFst = GetCurrentThreadTimes(); //100 nanosecond one tick
            
            for (int i = 0; i < iteration; i++) action.Action();
            long ticks = GetCurrentThreadTimes() - ticksFst;
            watch.Stop();

            // 4. Print CPU
            Console.ForegroundColor = currentForeColor;
            Console.WriteLine("\tTime Elapsed:\t\t" + 
               watch.ElapsedMilliseconds.ToString("N0") + "ms");
            Console.WriteLine("\tTime Elapsed (one time):" + 
               (watch.ElapsedMilliseconds / iteration).ToString("N0") + "ms");

            Console.WriteLine("\tCPU time:\t\t" + (ticks * 100).ToString("N0") 
                + "ns");
            Console.WriteLine("\tCPU time (one time):\t" + (ticks * 100 / 
                iteration).ToString("N0") + "ns");

            // 5. Print GC
            for (int i = 0; i <= GC.MaxGeneration; i++)
            {
                int count = GC.CollectionCount(i) - gcCounts[i];
                Console.WriteLine("\tGen " + i + ": \t\t\t" + count);
            }

            Console.WriteLine();

        }
    }

测试类

public class TestSleep3000 : IAction
{
    #region IAction Members

    public void Action()
    {
        Thread.Sleep(3000);
    }

    #endregion
}

public class TestEmptyMethod : IAction
{
    #region IAction Members

    public void Action()
    {
    }

    #endregion
}

public class TestStringConcat : IAction
{
    string s = "";

    #region IAction Members

    public void Action()
    {
        s += "a";
    }

    #endregion
}

public class TestStringBuilderConcat : IAction
{
    StringBuilder s = new StringBuilder();

    #region IAction Members

    public void Action()
    {
        s.Append("a");
    }

    #endregion
}

测试代码

采用接口

CodeTimer.Time("Thread Sleep", 1, new TestSleep3000());
            CodeTimer.Time("Thread Sleep", 10000000, new TestEmptyMethod());
            CodeTimer.Time("String Concat", 100000, new TestStringConcat());
            CodeTimer.Time("StringBuilder Conca", 100000, 
                 new TestStringBuilderConcat());

测试结果

Thread Sleep
        Time Elapsed:           2,997ms
        Time Elapsed (one time):2,997ms
        CPU time:               0ns
        CPU time (one time):    0ns
        Gen 0:                  0
        Gen 1:                  0
        Gen 2:                  0

Empty Method
        Time Elapsed:           138ms
        Time Elapsed (one time):0ms
        CPU time:               125,000,000ns
        CPU time (one time):    12ns
        Gen 0:                  0
        Gen 1:                  0
        Gen 2:                  0

String Concat
        Time Elapsed:           10,547ms
        Time Elapsed (one time):0ms
        CPU time:               10,546,875,000ns
        CPU time (one time):    105,468ns
        Gen 0:                  4102
        Gen 1:                  2661
        Gen 2:                  2545

StringBuilder Conca
        Time Elapsed:           4ms
        Time Elapsed (one time):0ms
        CPU time:               0ns
        CPU time (one time):    0ns
        Gen 0:                  0
        Gen 1:                  0
        Gen 2:                  0

采用委托

CodeTimer.Time("Thread Sleep", 1, delegate() { Thread.Sleep(3000); });
CodeTimer.Time("Empty Method", 10000000, delegate() { });

string a = "";

CodeTimer.Time("String Concat", 100000, delegate() { a += "a"; });

StringBuilder s = new StringBuilder();
CodeTimer.Time("StringBuilder Conca", 100000, delegate() { s.Append("a"); });

测试结果

Thread Sleep
        Time Elapsed:           2,989ms
        Time Elapsed (one time):2,989ms
        CPU time:               0ns
        CPU time (one time):    0ns
        Gen 0:                  0
        Gen 1:                  0
        Gen 2:                  0

Empty Method
        Time Elapsed:           156ms
        Time Elapsed (one time):0ms
        CPU time:               156,250,000ns
        CPU time (one time):    15ns
        Gen 0:                  0
        Gen 1:                  0
        Gen 2:                  0

String Concat
        Time Elapsed:           10,425ms
        Time Elapsed (one time):0ms
        CPU time:               10,406,250,000ns
        CPU time (one time):    104,062ns
        Gen 0:                  4102
        Gen 1:                  2661
        Gen 2:                  2545