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线程安全集合 ConcurrentDictionary<TKey, TValue> 类

2014-06-04 15:34  音乐让我说  阅读(812)  评论(0编辑  收藏  举报

ConcurrentDictionary<TKey, TValue> 类

【表示可由多个线程同时访问的键/值对的线程安全集合。】

支持 .NET Framework 4.0 及以上。

示例代码:

class CD_Ctor
{
        // Demonstrates:
        //      ConcurrentDictionary<TKey, TValue> ctor(concurrencyLevel, initialCapacity)
        //      ConcurrentDictionary<TKey, TValue>[TKey]
        static void Main()
        {
            // We know how many items we want to insert into the ConcurrentDictionary.
            // So set the initial capacity to some prime number above that, to ensure that
            // the ConcurrentDictionary does not need to be resized while initializing it.
            int NUMITEMS = 64;
            int initialCapacity = 101;

            // The higher the concurrencyLevel, the higher the theoretical number of operations
            // that could be performed concurrently on the ConcurrentDictionary.  However, global
            // operations like resizing the dictionary take longer as the concurrencyLevel rises. 
            // For the purposes of this example, we'll compromise at numCores * 2.
            int numProcs = Environment.ProcessorCount;
            int concurrencyLevel = numProcs * 2;

            // Construct the dictionary with the desired concurrencyLevel and initialCapacity
            ConcurrentDictionary<int, int> cd = new ConcurrentDictionary<int, int>(concurrencyLevel, initialCapacity);

            // Initialize the dictionary
            for (int i = 0; i < NUMITEMS; i++) cd[i] = i * i;

            Console.WriteLine("The square of 23 is {0} (should be {1})", cd[23], 23 * 23);
        }
}

 

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