public interface IDetector
  {
    double ActiveTime
    { get; set; }
    LinkedListNode<IDetector> DetectorNode
    {
      get;
      set;
    }
  }

 public interface ILRUDetector
  {
    void Update(IDetector item);
    void Detection(int timeout);
    double GetTime();
    Action<IList<IDetector>> Timeout { get; set; }
  }

 class LRUDetector : ILRUDetector, IDisposable
  {
    public LRUDetector()
    {
      mTimeWatch = new System.Diagnostics.Stopwatch();
      mTimeWatch.Restart();
    }
    private Buffers.XSpinLock xSpinLock = new Buffers.XSpinLock();
    private System.Diagnostics.Stopwatch mTimeWatch;
    private LinkedList<IDetector> mItems = new LinkedList<IDetector>();
    public Action<IList<IDetector>> Timeout
    {
      get; set;
    }
    public void Detection(int timeout)
    {
      double time = GetTime();
      List<IDetector> result = new List<IDetector>();
      using (xSpinLock.Enter())
      {
        LinkedListNode<IDetector> last = mItems.Last;
        while (last != null && (time - last.Value.ActiveTime) > timeout)
        {
          mItems.Remove(last);
          result.Add(last.Value);
          last.Value.DetectorNode = null;
          last = mItems.Last;
        }
      }
      if (Timeout != null && result.Count > 0)
        Timeout(result);
    }
    public void Update(IDetector item)
    {
      using (xSpinLock.Enter())
      {
        if (item.DetectorNode == null)
          item.DetectorNode = new LinkedListNode<IDetector>(item);
        item.ActiveTime = GetTime();
        if (item.DetectorNode.List == mItems)
          mItems.Remove(item.DetectorNode);
        mItems.AddFirst(item);
      }
    }
    public void Dispose()
    {
      mItems.Clear();
    }
    public double GetTime()
    {
      return mTimeWatch.Elapsed.TotalMilliseconds;
    }
  }

class Program
  {
    public class TestDetector : IDetector
    {
      public double ActiveTime { get; set; }
      public string Name { get; set; }
      public LinkedListNode<IDetector> DetectorNode { get; set; }
    }
    static void Main(string[] args)
    {
      LRUDetector lRUDetector = new LRUDetector();
      lRUDetector.Timeout = (items) =>
      {
        foreach (TestDetector item in items)
          Console.WriteLine($"{(item.Name)} timeout {lRUDetector.GetTime() - item.ActiveTime}ms");
      };
      System.Threading.Timer timer = null;
      timer = new System.Threading.Timer(o =>
      {
        timer.Change(-1, -1);
        lRUDetector.Detection(5000);
        timer.Change(5000, 5000);
      }, null, 5000, 5000);
      System.Threading.ThreadPool.QueueUserWorkItem(o =>
      {
        int i = 0;
        while (true)
        {
          System.Threading.Thread.Sleep(500);
          i++;
          TestDetector testDetector = new TestDetector();
          testDetector.Name = "my name is " + i;
          lRUDetector.Update(testDetector);
        }
      });
      Console.Read();
    }
  }