using System.Collections.Generic;

namespace SanAndreasUnity.Utilities
{

	/// <summary>
	/// Alternative to System.Collections.Concurrent.ConcurrentQueue
	/// (It's only available in .NET 4.0 and greater)
	/// </summary>
	/// <remarks>
	/// It's a bit slow (as it uses locks), and only provides a small subset of the interface
	/// Overall, the implementation is intended to be simple & robust
	/// </remarks>
	public class ConcurrentQueue<T>
	{
		private readonly System.Object queueLock = new System.Object();
		private readonly Queue<T> queue = new Queue<T>();

		public void Enqueue(T item)
		{
			lock (queueLock)
			{
				queue.Enqueue(item);
			}
		}

		public bool TryDequeue(out T result)
		{
			lock (queueLock)
			{
				if (queue.Count == 0)
				{
					result = default(T);
					return false;
				}

				result = queue.Dequeue();
				return true;
			}
		}
	}

}