自制线程池３

在自制线程池２中讲到了，实现了线程池中的一些不足之处，

今天我在前面的基础上改进了以下内容，

A。Thread.Suspend和Thread.Resume方法在2.0已经被Obslete，因此改用了其它方法来实现

B。原先新建的线程在空闲没有任务时是处于Suspend状态，如果起动了１００个线程，完成任务后还是有１００个线程存在，现在加入了策略，当线程空闲６０s没有被复用（重新获得任务）则该线程自动销毁。

C。更新了同步的方法，比前面的实现好多了，不过肯定还是存在些问题，同步，竞争读写，线程安全这些内容还是比较糊，在今后的实践中慢慢改进吧

D。使线程池可以实例化，这样可以创建多个专用的线程池，这样的好处是，一些任务对执行的时间没有要求，但是希望占用的资源低，我们可以给该线程池设定最大允许一个线程长时间执行这项工作，而另外的线程池是一些短时间的密集型请求，我们可以设定同时400个线程运行，同时将它的线程空闲注销时间设的短一些，以增强响应的能力。

该版本还存在的问题

A.代码不够清楚，多余的代码仅是注释掉了，并没有删除，这样以后看起来可以给自己一些思路，自己是怎么一步一步改过来的，不知道这个算不算是一个坏习惯，我也想把原先不用的代码删除了，但我怕以后自己都看不懂现在演化过来的代码是什么意思，大家有没有这样的情况

B.各个实例化的线程池之间无法共享复用空闲线程，这个是一个很大的问题，但是我还没想到实现的方法，为了这个问题想了一天多了。

C。再将SmartThreadPool中一些实用的功能补充进来。

另外发现

这个是实现的代码

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading;
using Amib.Threading.Internal;
using Rhino.Commons;

namespace ThreadPool2
{
    public delegate object WaitCallback2(object state);
    public delegate void SuccCallback(object state, object result);
    public delegate void ErrCallback(object state);
    /// <summary>
    /// 此线程池的作用是将某一类特殊的任务交给此线程池执行，
    /// 可以设定该线程池的最大线程数，
    /// 这类线程池的优点时，占用的资源少，优先级低，
    /// 适合于执行任务需要长期执行，不考虑时间因素的任务
    /// 同时根据在传入线程池时的标记key，可以Aborted指定任务，
    /// 若该任务正在执行或尚在执行队列中
    /// </summary>
    public class MyThreadPool2
    {
        /// <summary>
        /// 任务执行队列
        /// </summary>
        //static ThreadSafeQueue<WorkerThread> queue = new ThreadSafeQueue<WorkerThread>();
        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>
        SynchronizedDictionary<string, WorkerThread> dict = new SynchronizedDictionary<string, WorkerThread>();
        private object state;
        AutoResetEvent wait = new AutoResetEvent(false);
        AutoResetEvent wait2 = new AutoResetEvent(false);
        private int MaxLimitedTime { get; set; }
        private bool IsLimitedExecTime { get; set; }
        //private static int _maxThreadNum = 1;
        private int MaxThreadNum
        {
            //get { return _maxThreadNum; }
            //set { _maxThreadNum = value; }
            get;
            set;
        }
        private MyThreadPool2()
        {
            //System.Threading.ThreadPool.RegisterWaitForSingleObject(wait, new WaitOrTimerCallback(aa), state, 2000,true);
            //SetMaxThreadNum(2);
            //SetMaxExecTime(false, 10000);
        }
        /// <summary>
        /// 设置专用线程池的初始参数
        /// </summary>
        /// <param name="num">线程池的最大线程数，最小为１</param>
        /// <param name="b">是否起用限制最大单个任务执行时间设定</param>
        /// <param name="time">单个任务执行的最大时间</param>
        public MyThreadPool2(int num, bool b, int time)
        {
            System.Threading.ThreadPool.RegisterWaitForSingleObject(wait, new WaitOrTimerCallback(aa), state, 2000, true);
            if (num < 1)
                num = 1;
            MaxThreadNum = num;
            IsLimitedExecTime = b;
            MaxLimitedTime = time;
            if (IsLimitedExecTime)
                System.Threading.ThreadPool.RegisterWaitForSingleObject(wait2, new WaitOrTimerCallback(bb), state,
                                                                        MaxLimitedTime, true);
        }
        /// <summary>
        /// 定时将队列中的数据装载到线程中执行，如果还没有到达最大线程数还有任务则创建线程
        /// </summary>
        /// <param name="state"></param>
        /// <param name="timedOut"></param>
        private void aa(object state, bool timedOut)
        {
            lock(WorkerThread.Manual){
            WorkerThread.Manual.Reset();
            lock (queue)
            {
                //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>();
                List<string> tasks = new List<string>();
                //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)

                    //将不活动的线程记录下来并移除
                    if (!kvp.Value.Thread.IsAlive)
                        tasks.Add(kvp.Key);
                    //将活动且空闲的线程赋于新的任务
                    if (kvp.Value.Thread.IsAlive == true && kvp.Value.CurrentThreadState == WorkerThreadState.Idle)
                    {
                        //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));
                            //a.Thread = kvp.Value.Thread;
                            //newTask.Add(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;
                        //}

                    }
                }
                tasks.ForEach(t => 
                { 
                    dict.Remove(t);
                    Debug.WriteLine("移除销毁线程对应的dict中的键值项，key="+t);
                });
                removeKey.ForEach(t => dict.Remove(t));
                newTask.ForEach(t =>
                {
                    Debug.WriteLine("复用线程用于执行新任务"+t.Key);
                    dict.Add(t.Key, t);
                    t.StartExecTime = DateTime.Now;
                    t.Auto.Set();
                    //t.CurrentThreadState = WorkerThreadState.Busy;
                    //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();
                        Debug.WriteLine("新建线程用于执行新任务"+ wt.Key);


                        //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);
            }
            WorkerThread.Manual.Set();
            }
        }
        private void SetMaxThreadNum(int num)
        {
            if (num < 1)
                num = 1;
            MaxThreadNum = num;
        }
        private WorkerThread FindSpecificWorkerThreadByKey(string key)
        {
            WorkerThread wt;
            dict.TryGetValue(key, out wt);
            return wt;
        }
        /// <summary>
        /// 设定单线程允许执行任务的最长时间,该方法不能在运行时改变，须事前设定
        /// </summary>
        /// <param name="b"></param>
        /// <param name="time"></param>
        [Obsolete("abandon")]
        private void SetMaxExecTime(bool b, int time)
        {
            IsLimitedExecTime = b;
            MaxLimitedTime = time;
            if (IsLimitedExecTime)
                System.Threading.ThreadPool.RegisterWaitForSingleObject(wait2, new WaitOrTimerCallback(bb), state,
                                                                        MaxLimitedTime, true);
        }
        /// <summary>
        /// 当任务执行超时时，注销该线程
        /// </summary>
        /// <param name="state"></param>
        /// <param name="timedOut"></param>
        private void bb(object state, bool timedOut)
        {
            lock (WorkerThread.Manual)
            {
                WorkerThread.Manual.Reset();
                //lock (obj)
                lock (dict.SyncRoot)
                {
                    List<string> temp = new List<string>();
                    foreach (var kvp in dict)
                    {
                        if (kvp.Value.CurrentThreadState==WorkerThreadState.Busy &&DateTime.Now.Subtract(kvp.Value.StartExecTime).TotalMilliseconds > MaxLimitedTime)
                        {
                            temp.Add(kvp.Key);
                        }
                    }
                    foreach (var s in temp)
                    {
                        Debug.WriteLine("key="+s+"的任务超时，执行该任务的线程将被销毁");
                        _Aborted(s);
                    }
                    System.Threading.ThreadPool.RegisterWaitForSingleObject(wait2, new WaitOrTimerCallback(bb), state, MaxLimitedTime, true);
                }
                WorkerThread.Manual.Set();
            }

        }
        public void Aborted(string key)
        {
            lock (WorkerThread.Manual)
            {
                WorkerThread.Manual.Reset();
                _Aborted(key);
                WorkerThread.Manual.Set();
            }
        }

        private void _Aborted(string key)
        {
            lock (queue)
            {
                //任务如果还在队列中则删除该任务
                int index = queue.FindIndex(t => t.Key == key);
                if (index > -1)
                {
                    queue.RemoveAt(index);
                    Debug.WriteLine("从任务队列中移除指定key="+key+"的任务");
                }
            }
            //lock (dict.SyncRoot)
            //{
                #region old way now extract method FindSpecificWorkerThreadByKey to split this
                //WorkerThread v;
                //if (dict.TryGetValue(key, out v))
                //{
                //    v.Thread.Abort();
                //    //在调用Abort方法时，在指定线程上引发ThreadAbortException。以开始终止此线程的
                //    //过程。ThreadAbortException是—个可以由应用程序代码捕获的特殊异常，但除非调用
                //    //ResetAbort，否则会在catch块的结尾再次引发它。ResetAbod可以取消Abort的请求，并
                //    //阻止ThreadAbortException终止此线程。但是，线程不一定会立即中止，或者根本不中止。
                //    //如果线程在作为中止过程的一部分被调用的finally块中做非常大量的计算，从而无限期延
                //    //迟中止操作，则会发生这种情况。若要确保线程已经终止，请在调用Abort之后对线程调
                //    //用Join方法。
                //    v.Thread.Join();
                //    dict.Remove(key);
                //}
                #endregion
                WorkerThread v = FindSpecificWorkerThreadByKey(key);
                //没有发现指定key的线程表示，对应该key的任务已经执行完了，不需要再来取消该任务
                //或者指的key的线程虽然还在但它的状态已变为suspended，任务已完成，将等待下一个任务，实际不需要终止该线程
                //只有但指定的key的任务在执行时才删除
                //if (v != null && v.Thread.ThreadState != ThreadState.Suspended)
                if (v != null && v.CurrentThreadState == WorkerThreadState.Busy)
                {
                    dict.Remove(key);
                    /*
                在调用Abort方法时，在指定线程上引发ThreadAbortException。以开始终止此线程的
                过程。ThreadAbortException是—个可以由应用程序代码捕获的特殊异常，但除非调用
                ResetAbort，否则会在catch块的结尾再次引发它。ResetAbod可以取消Abort的请求，并
                阻止ThreadAbortException终止此线程。但是，线程不一定会立即中止，或者根本不中止。
                如果线程在作为中止过程的一部分被调用的finally块中做非常大量的计算，从而无限期延
                迟中止操作，则会发生这种情况。若要确保线程已经终止，请在调用Abort之后对线程调
                用Join方法。
                */
                    v.Thread.Abort();
                    v.Thread.Join();
                    Debug.WriteLine("销毁正在执行Key="+key+"的任务的线程");
                    if (v.ErrorCallback != null)
                    {
                        v.ErrorCallback(v.State);
                        //最后完成任务的时间
                        v.EndExecTime = DateTime.Now;
                    }

                }
            //}

            //wait.Set();
        }

        public void QueueUserWorkItem(WaitCallback2 callback, object state, string key, SuccCallback succ, ErrCallback err)
        {
            WorkerThread p = new WorkerThread()
            {
                WaitCallback = callback,
                State = state,
                Key = key,
                ErrorCallback = err,
                SuccessCallback = succ
            };
            //queue.Enqueue(p);
            lock (queue)
            {
                queue.Add(p);
                //Monitor.Pulse(queue);
            }
            wait.Set();
        }
        public void QueueUserWorkItem(WaitCallback2 callback, object state, SuccCallback succ, ErrCallback err)
        {
            QueueUserWorkItem(callback, state, System.Guid.NewGuid().ToString(), succ, err);
        }

        public void QueueUserWorkItem(WaitCallback2 callback, object state, string key)
        {
            //WorkerThread p = new WorkerThread()
            //            {
            //                WaitCallback = callback,
            //                State = state,
            //                Key = key
            //            };
            ////queue.Enqueue(p);
            //queue.Add(p);
            //wait.Set();
            QueueUserWorkItem(callback, state, key, null, null);
        }
        public void QueueUserWorkItem(WaitCallback2 callback, object state)
        {
            QueueUserWorkItem(callback, state, System.Guid.NewGuid().ToString());
        }

    }
    public enum WorkerThreadState : byte
    {
        None = 0,
        Busy = 1,
        Idle = 2
    }
    public class WorkerThread
    {
        public AutoResetEvent Auto = new AutoResetEvent(false);
        public static ManualResetEvent Manual = new ManualResetEvent(true);
        public WorkerThreadState CurrentThreadState { get; set; }
        public DateTime StartExecTime { get; set; }
        public DateTime EndExecTime { get; set; }
        public Thread Thread { get; set; }
        public string Key { get; set; }
        public WaitCallback2 WaitCallback { get; set; }
        public SuccCallback SuccessCallback { get; set; }
        public ErrCallback ErrorCallback { get; set; }
        public Object State { get; set; }
        public void Exec()
        {
            while (true)
            {
                this.CurrentThreadState = WorkerThreadState.Busy;
                if (this.SuccessCallback != null)
                    this.SuccessCallback(this.State, this.WaitCallback(this.State));
                else
                    this.WaitCallback(this.State);//如何将执行的结果返回，目前是通过SuccessCallback将结果作为参数返回，如果没有使用SuccessCallback将不能返回执行的结果
                this.EndExecTime = DateTime.Now;
                //如何将任务执行的起讫时间发给任务
                this.CurrentThreadState = WorkerThreadState.Idle;
                //this.Thread.Suspend();
                //等待60s如果在此期间未接收到新的任务该线程就退出
                if (!Auto.WaitOne(60 * 1000, false))
                    break;
                Manual.WaitOne();
            }
            Debug.WriteLine("线程销毁");
        }
        public WorkerThread Change(WorkerThread wt)
        {
            this.Key = wt.Key;
            this.WaitCallback = wt.WaitCallback;
            this.State = wt.State;
            this.StartExecTime = wt.StartExecTime;
            this.ErrorCallback = wt.ErrorCallback;
            this.SuccessCallback = wt.SuccessCallback;
            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.WaitCallback = 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();
        //    }
        //}
    }
}

线程安全的哈希表

using System.Collections;
using System.Collections.Generic;

namespace Amib.Threading.Internal
{
    public class SynchronizedDictionary<TKey, TValue>
    {
        private readonly Dictionary<TKey, TValue> _dictionary;
        private readonly object _lock;

        public SynchronizedDictionary()
        {
            _lock = new object();
            _dictionary = new Dictionary<TKey, TValue>();
        }
        public void Add(TKey key, TValue value)
        {
            lock (_lock)
            {
                _dictionary.Add(key, value);
            }
        }
        public bool TryGetValue(TKey key,out TValue value)
        {
            lock(_lock)
            {
                return this._dictionary.TryGetValue(key, out value);
            }
        }
        public int Count
        {
            get { lock (_lock) { return _dictionary.Count; } }
        }

        public bool Contains(TKey key)
        {
            lock (_lock)
            {
                return _dictionary.ContainsKey(key);
            }
        }

        public void Remove(TKey key)
        {
            lock (_lock)
            {
                _dictionary.Remove(key);
            }
        }

        public object SyncRoot
        {
            get { return _lock; }
        }

        public TValue this[TKey key]
        {
            get
            {
                lock (_lock)
                {
                    return _dictionary[key];
                }
            }
            set
            {
                lock (_lock)
                {
                    _dictionary[key] = value;
                }
            }
        }

        public Dictionary<TKey, TValue>.KeyCollection Keys
        {
            get
            {
                lock (_lock)
                {
                    return _dictionary.Keys;
                }
            }
        }

        public Dictionary<TKey, TValue>.ValueCollection Values
        {
            get
            {
                lock (_lock)
                {
                    return _dictionary.Values;
                }
            }
        }
        public void Clear()
        {
            lock (_lock)
            {
                _dictionary.Clear();
            }
        }

        public Dictionary<TKey, TValue>.Enumerator GetEnumerator()
        {
            lock (_lock)
            {
                return this._dictionary.GetEnumerator();
            }
        }

    }
}

测试用例１

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using ThreadPool2;

namespace ThreadPoolTest.MyThreadPool2Test
{
    class Class1
    {
        /// <summary>
        /// 
        /// </summary>
        /// <param name="args"></param>
        static void Main(string[] args)
        {
            MyThreadPool2 pool=new MyThreadPool2(1,true,10000);
            object state=new object();
            pool.QueueUserWorkItem(call1,state,"task1",succ,err);
            pool.QueueUserWorkItem(call2, state, "task2", succ, err);
            pool.QueueUserWorkItem(call2, state, "task3", succ, err);

            Console.ReadLine();
        }

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

        private static void succ(object state, object result)
        {
            Console.WriteLine("succ");
        }

        private static object call1(object state)
        {
            while(true)
            {
                Thread.Sleep(2000);
                Console.WriteLine("call1");
            }
            return null;
        }
        private static object call2(object state)
        {
            Console.WriteLine("call2");
            return null;
        }
    }
}

测试用例２

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using ThreadPool2;

namespace ThreadPoolTest.MyThreadPool2Test
{
    class Class2
    {
        static void Main(string[] args)
        {
            MyThreadPool2 pool=new MyThreadPool2(100,true,20000);
            //Stopwatch sw=new Stopwatch();
            for(var i=0;i<10000;i++)
                pool.QueueUserWorkItem(call,i,i.ToString(),succ,err);

        }

        private static void err(object state)
        {
            Console.WriteLine("process err when value={0}",state);
        }

        private static void succ(object state, object result)
        {
            Console.WriteLine("{0}'s sqrt is {1}",state,result);
        }

        private static object call(object state)
        {
            return Math.Sqrt(Convert.ToDouble(state));
        }
    }
}

在做测试二是，我截了两张图，并不能说说什么，供参考

我是在Debug模式下测的，内存占用可能会多些，