Lazy Man’s Blog

1)writers can put something in queue
2)reader can take something from queue
3) if queue is empty readers wait while writers put something in queue

public class SynchronyzedQueue<T>
    {
        readonly object _rootSync = new object();//sync internal queue 
        readonly Queue<T> _queue= new Queue<T>();//internal queue 
        readonly Semaphore _semaphore = new Semaphore(0,int.MaxValue);
       
        /// <summary>
        /// Enqueue element from queue and release semaphore
        /// </summary>
        /// <param name="item"></param>
        public void Enqueue(T item)
        {
            lock (_rootSync)
            {
                _queue.Enqueue(item);  
            }
            _semaphore.Release();
        }
        /// <summary>
        /// Dequeue element to queue and WaitOne semaphore
        /// </summary>
        /// <param name="item"></param>
        public T Dequeue()
        {
            _semaphore.WaitOne();
            lock (_rootSync)
            {
                return _queue.Dequeue();
            }
        }
        /// <summary>
        /// clean Queue and invoke all sleep threads. Produce Exception if has sleeping threads in Dequeue operation
        /// </summary>
        public void Clear()
        {
            lock (_rootSync)
            {
                int releaseCount = _queue.Count;
                _queue.Clear();
                _semaphore.Release(releaseCount);
            }
        }
    }