private ConcurrentQueue<string> inQueue = new ConcurrentQueue<string>();

private object lockObject = new object();
private Queue<string> queue = new Queue<string>();

        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);
        }