C# 同步/并发队列ConcurrentQueue （表示线程安全的先进先出 (FIFO) 集合）

static void Main(string[] args)
{
// Construct a ConcurrentQueue.
ConcurrentQueue<int> cq = new ConcurrentQueue<int>();

// Populate the queue.
for (int i = 0; i < 10000; i++) cq.Enqueue(i);

// Peek at the first element.
int result;
if (!cq.TryPeek(out result))
{
Console.WriteLine("CQ: TryPeek failed when it should have succeeded");
}
else if (result != 0)
{
Console.WriteLine("CQ: Expected TryPeek result of 0, got {0}", result);
}

int outerSum = 0;
// An action to consume the ConcurrentQueue.
Action action = () =>
{
int localSum = 0;
int localValue;
while (cq.TryDequeue(out localValue)) localSum += localValue;
Interlocked.Add(ref outerSum, localSum);
};

// Start 4 concurrent consuming actions.
Parallel.Invoke(action, action, action, action);

Console.WriteLine("outerSum = {0}, should be 49995000", outerSum);
}