自已实现线程池

.net内置的threadpool对于加入执行队列的任务，或是正在执行的任务无法取消，这对于我的项目来说有问题，因此要自定义一个线程池。

我的项目中具体的应用情节如下，某一个操作会非常耗时（将网址插入bdb中），如果将其加入线程池中，很可能将线程池中的资源耗尽，因此我希望我可以定义一个maxThreadNum用来控制执行此在操作最大允许同时执行的线程数，同时设定线程等级为最低ThreadPriority.Lowest，我只要这个操作慢慢执行就行了。

 

代码还需要重构，高手请指点下，对锁的机制还是不太清楚，

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using Rhino.Commons;

namespace ThreadPool
{
    public static class MyThreadPool
    {
        static object obj = new object();
        static AutoResetEvent wait = new AutoResetEvent(false);
        static MyThreadPool()
        {
            System.Threading.ThreadPool.RegisterWaitForSingleObject(wait, new WaitOrTimerCallback(aa), state, 2000,true);
            SetMaxThreadNum(1);
        }

        private static void aa(object state, bool timedOut)
        {
            lock (obj)
            {
                //判断任务队列中有无积压的任务且有无空闲的线程，如果符合上述条件则执行之
                List<string> removeKey = new List<string>();
                List<WorkerThread> newTask=new List<WorkerThread>();
                //Dictionary<string,WorkerThread> addDict=new Dictionary<string, WorkerThread>();
                foreach (var kvp in dict)
                {//kvp.Value.ThreadState == ThreadState.Unstarted || 
                    if (kvp.Value.Thread.ThreadState == ThreadState.Suspended)
                    {
                        //dict.Remove(kvp.Key);//cancle because of lock

                        WorkerThread a=queue.FirstOrDefault();
                        if (a != null)
                        {
                            removeKey.Add(kvp.Key);
                            //addDict.Add(a.Key, kvp.Value.Change(a));
                            newTask.Add(kvp.Value.Change(a));

                            queue.RemoveAt(0);
                            //dict.Add(a.Key, kvp.Value.Change(a));//cancle because of lock
                            //将参数加到线程中，并改变线程的状态
                            //dict[a.Key].Thread.Resume();
                        }
                        else
                            break;
                        //else
                        //{
                        //    System.Threading.ThreadPool.RegisterWaitForSingleObject(wait, new WaitOrTimerCallback(aa), state,
                        //                                                            2000, true);
                        //    return;
                        //}

                    }
                }
                removeKey.ForEach(t=>dict.Remove(t));
                newTask.ForEach(t =>
                {
                    dict.Add(t.Key, t);
                    t.Thread.Resume();
                });
                while (queue.Count > 0 && dict.Count < MaxThreadNum)
                {
                    //未到线程池最大池程数时，增加线程
                    WorkerThread b = queue.FirstOrDefault();
                    if (b!=null)
                    {
                        queue.RemoveAt(0);
                        //Thread thd = new Thread(new ThreadStart(b.Exec));
                        //thd.Priority = ThreadPriority.Lowest;
                        //dict.Add(b.Key, thd);
                        //thd.Start();
                        WorkerThread wt = new WorkerThread();
                        wt.Start(b);
                        dict.Add(wt.Key, wt);
                        wt.Thread.Start();

                        //将参数加到线程中，并改变线程的状态
                    }


                }
                System.Threading.ThreadPool.RegisterWaitForSingleObject(wait, new WaitOrTimerCallback(aa), state, 2000, true);
            }
        }


        //private static int _maxThreadNum = 1;
        public static int MaxThreadNum
        {
            //get { return _maxThreadNum; }
            //set { _maxThreadNum = value; }
            get; set;
        }
        public static void SetMaxThreadNum(int num)
        {
            if (num < 1)
                num = 1;
            MaxThreadNum = num;
        }

        /// <summary>
        /// 任务执行队列
        /// </summary>
        //static ThreadSafeQueue<WorkerThread> queue = new ThreadSafeQueue<WorkerThread>();
        
        static List<WorkerThread> queue=new List<WorkerThread>();
        /// <summary>
        /// 目前暂定为只使用一个线程，以免耗近资源
        /// </summary>
        static Dictionary<string, WorkerThread> dict = new Dictionary<string, WorkerThread>(1);

        private static object state;

        public static void Aborted(string key)
        {
            lock (obj)
            {
                WorkerThread v;
                if (dict.TryGetValue(key, out v))
                {
                    v.Thread.Abort();
                    dict.Remove(key);
                }
                int index = queue.FindIndex(t => t.Key == key);
                if (index>-1)
                    queue.RemoveAt(index);
                wait.Set();
            }
        }

        public static void QueueUserWorkItem(WaitCallback callback, object state, string key)
        {
            WorkerThread p = new WorkerThread()
                        {
                            Callback = callback,
                            State = state,
                            Key = key
                        };
            //queue.Enqueue(p);
            queue.Add(p);
            wait.Set();
        }


    }

}
public class WorkerThread
{
    public Thread Thread { get; set; }
    public string Key { get; set; }
    public WaitCallback Callback { get; set; }
    public Object State { get; set; }
    public void Exec()
    {
        while (true)
        {
            this.Callback(this.State);
            this.Thread.Suspend();
        }
    }
    public WorkerThread Change(WorkerThread wt)
    {
        this.Key = wt.Key;
        this.Callback = wt.Callback;
        this.State = wt.State;
        return this;
    }
    public void Start(WorkerThread wt)
    {
        this.Change(wt);
        this.Thread = new Thread(new ThreadStart(this.Exec));
        this.Thread.Priority = ThreadPriority.Lowest;
    }

    //public void Start(WaitCallback callback,Object state)
    //{
    //    this.Callback = callback;
    //    this.State = state;
    //    if(this.Thread==null){
    //        this.Thread = new Thread(new ThreadStart(this.Exec));
    //        this.Thread.Priority = ThreadPriority.Lowest;
    //        this.Thread.IsBackground = true;
    //        this.Thread.Start();
    //        return;
    //    }
    //    if(this.Thread.ThreadState==ThreadState.Suspended)
    //    {
    //        this.Thread.Resume();
    //    }
    //}
}

 

测试代码

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace ThreadPoolTest
{
    public class Class1
    {
        static ManualResetEvent wait=new ManualResetEvent(false);
        static void Main(string[] args)
        {
            object state=new object();
            ThreadPool.MyThreadPool.QueueUserWorkItem(new WaitCallback(test), state, "aa");
            ThreadPool.MyThreadPool.QueueUserWorkItem(new WaitCallback(test2), state, "bb");
            System.Threading.Thread.Sleep(10000);
            wait.Set();
            System.Threading.Thread.Sleep(10000);
            Console.WriteLine("aborted aa");
            ThreadPool.MyThreadPool.Aborted("aa");
            ThreadPool.MyThreadPool.QueueUserWorkItem(new WaitCallback(test3), state, "cc");
            System.Threading.Thread.Sleep(10000);
            Console.WriteLine("aborted bb");
            ThreadPool.MyThreadPool.Aborted("bb");
          
            ThreadPool.MyThreadPool.QueueUserWorkItem(new WaitCallback(test4), state, "dd");
            Console.ReadLine();
        }

        private static void test4(object state)
        {
            Console.WriteLine("test4");
        }

        private static void test3(object state)
        {
            Console.WriteLine("test3");
        }

        private static void test2(object state)
        {
            while(true)
            {
                Console.WriteLine("test2");
                Thread.Sleep(2000);
            }
        }

        private static void test(object state)
        {
            while (true)
            {
                Console.WriteLine("test");
                Thread.Sleep(2000);
                wait.WaitOne();//只执行一次
            }
        }
    }
}