[C#]Thread Safe Dictionary in .NET 2.0

using System.Collections.Generic;using System.Threading;namespace CSharpUtilHelpV2{    /// <summary>    /// 基于.NET 2.0的對(duì)于Dictionary線程安全操作工具類    /// 說(shuō)明    /// 默認(rèn)讀鎖超時(shí)1000毫秒    /// 默認(rèn)寫鎖超時(shí)1000毫秒    /// .NET 4.0 可以使用ConcurrentDictionary來(lái)實(shí)現(xiàn)。    /// </summary>    /// <typeparam name="T">泛型</typeparam>    public class ThreadSafeDictionaryV2<T>    {        /*參考資料         * 1.         * 使用Monitor或Mutex進(jìn)行同步控制的問(wèn)題：由于獨(dú)占訪問(wèn)模型不允許任何形式的并發(fā)訪問(wèn)，這樣的效率總是不太高。         * 許多時(shí)候，應(yīng)用程序在訪問(wèn)資源時(shí)是進(jìn)行讀操作，寫操作相對(duì)較少。為解決這一問(wèn)題，         * C#提供了System.Threading.ReaderWriterLock類以適應(yīng)多用戶讀/單用戶寫的場(chǎng)景。該類可實(shí)現(xiàn)以下功能：         * 如果資源未被寫操作鎖定，那么任何線程都可對(duì)該資源進(jìn)行讀操作鎖定，并且對(duì)讀操作鎖數(shù)量沒(méi)有限制，即多個(gè)線程可同時(shí)對(duì)該資源進(jìn)行讀操作鎖定，以讀取數(shù)據(jù)。         * 如果資源未被添加任何讀或?qū)懖僮麈i，那么一個(gè)且僅有一個(gè)線程可對(duì)該資源添加寫操作鎖定，以寫入數(shù)據(jù)。簡(jiǎn)單的講就是：讀操作鎖是共享鎖，允許多個(gè)線程同時(shí)讀取數(shù)據(jù)；         * 寫操作鎖是獨(dú)占鎖，同一時(shí)刻，僅允許一個(gè)線程進(jìn)行寫操作。         * 引用鏈接：http://www.csharpwin.com/dotnetspace/12761r5814.shtml         *          * 2.         * ReaderWriterLock 用于同步對(duì)資源的訪問(wèn)。在任一特定時(shí)刻，它允許多個(gè)線程同時(shí)進(jìn)行讀訪問(wèn)，或者允許單個(gè)線程進(jìn)行寫訪問(wèn)。         * 在資源不經(jīng)常發(fā)生更改的情況下，ReaderWriterLock 所提供的吞吐量比簡(jiǎn)單的一次只允許一個(gè)線程的鎖（如 Monitor）更高。         * 在多數(shù)訪問(wèn)為讀訪問(wèn)，而寫訪問(wèn)頻率較低、持續(xù)時(shí)間也比較短的情況下，ReaderWriterLock 的性能最好。         * 多個(gè)讀線程與單個(gè)寫線程交替進(jìn)行操作，所以讀線程和寫線程都不會(huì)長(zhǎng)時(shí)間阻止。         * 大多數(shù)在 ReaderWriterLock 上獲取鎖的方法都采用超時(shí)值。使用超時(shí)可以避免應(yīng)用程序中出現(xiàn)死鎖。         * 如果不使用超時(shí)，這兩個(gè)線程將出現(xiàn)死鎖。         * 引用鏈接：http://msdn.microsoft.com/zh-cn/library/system.threading.readerwriterlock(v=vs.80).aspx         *          * 3.其他鏈接         * http://tinythreadsafecache.codeplex.com/SourceControl/latest#TinyThreadSafeCache.cs         * http://www.grumpydev.com/2010/02/25/thread-safe-dictionarytkeytvalue/         * http://stackoverflow.com/questions/157933/whats-the-best-way-of-implementing-a-thread-safe-dictionary         * http://stackoverflow.com/questions/15095817/adding-to-a-generic-dictionary-causes-indexoutofrangeexception         */        ReaderWriterLock rwlock = new ReaderWriterLock();//聲明讀寫鎖 .NET 3.5+ 推薦用ReaderWriterLockSlim        Dictionary<string, T> dic = new Dictionary<string, T>();//Dictionary        static int readerTimeout = 1000;//默認(rèn)讀鎖超時(shí)1000毫秒        static int writerTimeout = 1000;//默認(rèn)寫鎖超時(shí)1000毫秒        /// <summary>        /// 默認(rèn)構(gòu)造函數(shù)        /// </summary>        public ThreadSafeDictionaryV2()        {        }        /// <summary>        /// 帶參構(gòu)造函數(shù)        /// </summary>        /// <param name="_readerTimeout">讀鎖超時(shí)設(shè)置【單位毫秒】</param>        /// <param name="_writerTimeout">寫鎖超時(shí)設(shè)置【單位毫秒】</param>        public ThreadSafeDictionaryV2(int _readerTimeout, int _writerTimeout)        {            readerTimeout = _readerTimeout;            writerTimeout = _writerTimeout;        }        /// <summary>        /// This【線程安全】        /// </summary>        /// <param name="key">鍵</param>        /// <returns>值</returns>        public T this[string key]        {            get            {                rwlock.AcquireReaderLock(readerTimeout);                try                {                    return dic[key];                }                finally                {                    rwlock.ReleaseReaderLock();                }            }            set            {                rwlock.AcquireWriterLock(writerTimeout);                try                {                    dic[key] = value;                }                finally                {                    rwlock.ReleaseWriterLock();                }            }        }        /// <summary>        /// Add【線程安全】        /// 默認(rèn)超時(shí)1000毫秒        /// </summary>        /// <param name="key">鍵</param>        /// <param name="val">值</param>        public void Add(string key, T val)        {            Add(key, val, writerTimeout);        }        /// <summary>        /// Add【線程安全】        /// </summary>        /// <param name="key">鍵</param>        /// <param name="val">值</param>        /// <param name="timeout">超時(shí)設(shè)置【毫秒】</param>        public void Add(string key, T val, int timeout)        {            rwlock.AcquireWriterLock(timeout);            try            {                dic[key] = val;            }            finally            {                rwlock.ReleaseWriterLock();            }        }        /// <summary>        /// Get【線程安全】        /// 默認(rèn)超時(shí)1000毫秒        /// </summary>        /// <param name="key">鍵</param>        /// <returns>值</returns>        public T Get(string key)        {            return Get(key, readerTimeout);        }        /// <summary>        /// Get【線程安全】        /// </summary>        /// <param name="key">鍵</param>        /// <param name="timeout">超時(shí)設(shè)置【毫秒】</param>        /// <returns>值</returns>        public T Get(string key, int timeout)        {            rwlock.AcquireReaderLock(timeout);            try            {                T val;                dic.TryGetValue(key, out val);                return val;            }            finally            {                rwlock.ReleaseReaderLock();            }        }        /// <summary>        /// Remove【線程安全】        /// 默認(rèn)超時(shí)1000毫秒        /// </summary>        /// <param name="key">鍵</param>        public void Remove(string key)        {            Remove(key, writerTimeout);        }        /// <summary>        /// Remove【線程安全】        /// </summary>        /// <param name="key">鍵</param>        /// <param name="timeout">超時(shí)設(shè)置【毫秒】</param>        public void Remove(string key, int timeout)        {            rwlock.AcquireWriterLock(timeout);            try            {                dic.Remove(key);            }            finally            {                rwlock.ReleaseWriterLock();            }        }        /// <summary>        /// Clear【線程安全】        /// 默認(rèn)超時(shí)1000毫秒        /// </summary>        public void Clear()        {            Clear(writerTimeout);        }        /// <summary>        /// Clear【線程安全】        /// </summary>        /// <param name="timeout">超時(shí)設(shè)置【毫秒】</param>        public void Clear(int timeout)        {            rwlock.AcquireWriterLock(timeout);            try            {                dic.Clear();            }            finally            {                rwlock.ReleaseWriterLock();            }        }        /// <summary>        /// ContainsKey【線程安全】        /// 默認(rèn)超時(shí)1000毫秒        /// </summary>        /// <param name="key">鍵</param>        /// <returns>是否包含</returns>        public bool ContainsKey(string key)        {            return ContainsKey(key, readerTimeout);        }        /// <summary>        /// ContainsKey【線程安全】        /// </summary>        /// <param name="key">鍵</param>        /// <param name="timeout">超時(shí)設(shè)置【毫秒】</param>        /// <returns>是否包含</returns>        public bool ContainsKey(string key, int timeout)        {            rwlock.AcquireReaderLock(timeout);            try            {                return dic.ContainsKey(key);            }            finally            {                rwlock.ReleaseReaderLock();            }        }        /// <summary>        /// Count【線程安全】        /// 默認(rèn)超時(shí)1000毫秒        /// </summary>        /// <returns></returns>        public int Count()        {            return Count(readerTimeout);        }        /// <summary>        /// Count【線程安全】        /// </summary>        /// <param name="timeout">超時(shí)設(shè)置【毫秒】</param>        /// <returns>Count</returns>        public int Count(int timeout)        {            rwlock.AcquireReaderLock(timeout);            try            {                return dic.Count;            }            finally            {                rwlock.ReleaseR