下面是代碼，希望大家提出更好的建議：
1.ThreadManager.cs
using System;
using System.Threading;
using System.Collections;
namespace CustomThreadPool
{
/// <summary>
/// 線程管理器，會開啓或喚醒一個線程去執行指定的回調方法
/// </summary>
public class ThreadManager
{
private static ArrayList threadList = new ArrayList(); //線程列表，靜態
//不允許創建實例
private ThreadManager()
{
}
/// <summary>
/// 靜態方法，開啓或喚醒一個線程去執行指定的回調方法
/// </summary>
/// <param name="waitCallback">委託實例</param>
/// <param name="obj">傳遞給回調方法的參數</param>
/// <param name="timeOut">當沒有可用的線程時的等待時間，以毫秒爲單位</param>
/// <returns></returns>
public static bool QueueUserWorkItem(WaitCallback waitCallback, Object obj, int timeOut)
{
//鎖住共享資源，實現線程安全
lock(threadList)
{
try
{
//如果線程列表爲空，填充線程列表
if (threadList.Count == 0)
{
InitThreadList();
}
long startTime = DateTime.Now.Ticks;
do
{
//遍歷線程列表，找出可用的線程
foreach(MyThread myThread in threadList)
{
//線程爲空，需要創建線程
if (myThread.T == null)
{
myThread.Start(waitCallback, obj, false);
return true;
}
else if (myThread.T.ThreadState == ThreadState.Suspended)
{//線程爲掛起狀態，喚醒線程
myThread.Start(waitCallback, obj, true);
return true;
}
}
//在線程 Sleep 前釋放鎖
Monitor.PulseAll(threadList);
Thread.Sleep(500);
}while (((DateTime.Now.Ticks - startTime) / 10000) < timeOut);
}
finally
{
Monitor.Exit(threadList);
}
}
return false;
}
//使用 MyThread 對象填充線程列表，注意，這個時候線程並沒有啓動
private static void InitThreadList()
{
threadList = new ArrayList();
for (int i = 0; i < 10; i++)
{
MyThread t = new MyThread();
threadList.Add(t);
}
}
}
}
2.MyThread.cs
using System;
using System.Threading;
namespace CustomThreadPool
{
/// <summary>
/// 封裝 .NET 框架提供的 Thread
/// </summary>
internal class MyThread
{
private Thread t; //線程
private WaitCallback w; //委託，這裏直接用 .NET 框架自帶的，也可以根據需要自己定義一個
private Object o; //傳遞給符合委託的回調方法的參數值，根據委託的定義而定
/// <summary>
/// 執行回調方法的線程
/// </summary>
public Thread T
{
get
{
return t;
}
}
public MyThread()
{
}
/// <summary>
/// 開啓新線程或喚醒線程，去執行回調方法
/// </summary>
/// <param name="w">用回調方法實例化了的委託實例</param>
/// <param name="o">傳遞給回調方法的參數值</param>
/// <param name="isSuspend">true 表示線程爲掛起狀態，false 則表示線程還沒創建</param>
public void Start(WaitCallback w, Object o, bool isSuspend)
{
//開啓新線程或喚醒線程前，先設置
this.w = w;
this.o = o;
//線程爲掛起狀態，喚醒線程繼續執行
if (isSuspend)
{
t.Resume();
}
else
{//線程還沒有創建，創建一個新線程，並執行
t = new Thread(new ThreadStart(this.ThreadProc));
t.Start();
}
}
/// <summary>
/// 線程執行的方法
/// </summary>
private void ThreadProc()
{
//死循環，使線程喚醒後不是退出，而是繼續通過委託執行回調方法
while (true)
{
//通過委託執行回調方法
w(o);
t.Suspend();
}
}
}
}
3.Test.cs
using System;
using System.Threading;
namespace CustomThreadPool
{
/// <summary>
/// 測試自定義線程池
/// </summary>
class Test
{
/// <summary>
/// 應用程序的主入口點。
/// </summary>
[STAThread]
static void Main(string[] args)
{
//
// TODO: 在此處添加代碼以啓動應用程序
//
for (int i = 0; i < 5; i++)
{
Console.WriteLine("Start thread {0}", i.ToString());
Thread t = new Thread(new ThreadStart(WorkThread));
t.Start();
}
Console.ReadLine();
Thread.CurrentThread.Abort();
}
public static void WorkThread()
{
for (int i = 0; i < 10; i++)
{
if (i % 2 == 0)
{
if (!ThreadManager.QueueUserWorkItem(new WaitCallback(ThreadProcOne), i, 2000))
{
Console.WriteLine("Failed" + i.ToString());
}
}
else
{
if (!ThreadManager.QueueUserWorkItem(new WaitCallback(ThreadProcTwo), i, 2000))
{
Console.WriteLine("Failed" + i.ToString());
}
}
}
Thread.CurrentThread.Abort();
}
public static void ThreadProcOne(Object stateInfo)
{
Console.WriteLine("Test custom threadpool:" + ((int)stateInfo).ToString());
}
public static void ThreadProcTwo(Object stateInfo)
{
Console.WriteLine("Change work:" + ((int)stateInfo).ToString());
}
}
}