PollingWorker.cs

using System.Collections.Generic;

namespace System.Threading
{
    public class PollingWorker : IPollingWorker,IDisposable
    {
		private class TickAction
		{
			public string Name { get; set; }
			public Action Work { get; set; }
			public int Every { get; set; }
		}

		private class IntervalAction
		{

			public IntervalAction()
			{
				Last = DateTime.Now;
			}

			public string Name { get; set; }
			public Action Work { get; set; }
			public TimeSpan Every { get; set; }
			public DateTime Last { get; set; }
		}

		private const int DefaultIntervalInMillis = 1000; // 1 second 
		private const int WaitIntervalInMillis = 20; // MS
		private Thread _labourer = null;
		private int _pollingIntervalInMillis = DefaultIntervalInMillis;
		private Action<object> _work = null;
		private bool _isWorking = false;
		private object _state = new object();
		private AutoResetEvent _resetTimer = new AutoResetEvent(false);
		private bool _itsTimeToQuite = false;
		private bool _poked = false;
		private bool _isCurrentlyWorking = false;
		private Dictionary<string, TickAction> _tickActions = new Dictionary<string, TickAction>();
		private Dictionary<string, IntervalAction> _intervalActions = new Dictionary<string, IntervalAction>();

		private long _tickCount = 0;

		public string Name
		{
			get { return _labourer.Name; }
			set { _labourer.Name = value; }
		}      
       
        public PollingWorker(int intervalInMillis, Action work) :
			this(intervalInMillis, (object o) => { work(); }, null, Guid.NewGuid().ToString())
		{

		}

		public PollingWorker(int intervalInMillis, Action<object> work, object state) :
			this(intervalInMillis, work, state, Guid.NewGuid().ToString())
		{

		}

		public PollingWorker(int intervalInMillis, Action<object> work, object state, string name)
		{
			_pollingIntervalInMillis = intervalInMillis;
			_labourer = new Thread(new ThreadStart(TryDoingSomeWork));
			_labourer.Name = name;
			_work = work;
		}

		public int PollingIntervalInMillis
		{
			get { return _pollingIntervalInMillis; }
			set
			{
				_pollingIntervalInMillis = value;
			}
		}

		public void StartWork()
		{
			StartWork(true);
		}

		public void StartWork(bool initialWait)
		{
			_isWorking = true;
			_poked = !initialWait;
			_labourer.Start();
		}


		public void PauseWork()
		{
			_isWorking = false;
		}

        public void ContinueWork()
        {
            _isWorking = true;
        }

		public void Quit()
		{
			Quit(int.MaxValue);
		}

		public int ConvertSecondToTick(int every)
		{
			return (every * 1000 / PollingIntervalInMillis);
		}


		public void Quit(int maximumWaitToFinishCurrentWorkMS)
		{
			int totalWait = 0;
			_itsTimeToQuite = true;
			_isWorking = false;
			_resetTimer.Set();
			while (_isCurrentlyWorking && Thread.CurrentThread.Name != _labourer.Name) // in case Quit is called from Work 
			{
				Thread.Sleep(WaitIntervalInMillis);
				totalWait += WaitIntervalInMillis;
				if (totalWait > maximumWaitToFinishCurrentWorkMS)
					break;
			}
			Dispose();
		}

		// poke to wake up !
		public void Poke()
		{
			try
			{
				// if you call set on the same thread while it is not on waitOne
				// it does not work 
				if (Thread.CurrentThread.Name == this.Name)
					//_resetTimer.Set();
					_poked = true;
				else
					_resetTimer.Set();
			}
			catch
			{
				// ignore any error with poking 
			}

		}

		private void TryDoingSomeWork()
		{
			while (!_itsTimeToQuite)
			{
				//Debug.WriteLine(string.Format("{0:ss fff}\t{1}\t{2}\t{3}", DateTime.Now, this.Name, string.Empty, string.Empty));
				if (!_poked)
					_resetTimer.WaitOne(_pollingIntervalInMillis, false);

				_poked = false;

				// timed-out which means timer's pulse, so do some work 
				if (_isWorking)
				{
					_isCurrentlyWorking = true;
					_work(_state);
					_tickCount++;
					ProcessActions();
					_isCurrentlyWorking = false;
				}
			}

		}

		public void RegisterIntervalAction(TimeSpan every, Action action)
		{
			RegisterIntervalAction(Guid.NewGuid().ToString(), every, action);	
		}

		public void RegisterIntervalAction(string name, TimeSpan every, Action action)
		{
			_intervalActions.Add(name, new IntervalAction()
			                           	{
			                           		Every = every,
											Name = name,
											Work = action
			                           	});
		}

		public void RegisterTickAction(int every, Action action)
		{
			RegisterTickAction(Guid.NewGuid().ToString(), every, action);
		}

		public void RegisterTickAction(string name, int every, Action action)
		{
			lock (_tickActions)
			{
				_tickActions.Add(name, new TickAction() { Every = every, Work = action, Name = name });				
			}
		}

		public void UpdateTick(string name, int every)
		{
			lock (_tickActions)
			{
				_tickActions[name].Every = every;
			}
		}

		public void ClearActions()
		{
			lock (_tickActions)
			{
				_tickActions.Clear();
			}
			lock (_intervalActions)
			{
				_intervalActions.Clear();
			}
		}
 

		private void ProcessActions()	
		{

			// ticks 
			TickAction[] copy;
			lock (_tickActions)
			{
				copy = new TickAction[_tickActions.Count];
				_tickActions.Values.CopyTo(copy, 0);
			}

			foreach (var tickAction in copy)
			{
				if (_tickCount % tickAction.Every == 0)
					tickAction.Work();
			}

			// intervals 
			lock (_intervalActions)
			{
				foreach (var intervalAction in _intervalActions.Values)
				{
					if(DateTime.Now.Subtract(intervalAction.Last)>intervalAction.Every)
					{
						intervalAction.Work();
						intervalAction.Last = DateTime.Now;
					}
				}
			}
			


		}

		public object State
		{
			get { return _state; }
			set
			{
				lock (_state)
				{
					_state = value;
				}
			}
		}


		public bool IsWorking
		{
			get { return _isWorking; }
		}


		#region IDisposable Members

		public void Dispose()
		{
			try
			{
				_resetTimer.Close();
				_labourer.Abort();
			}
			catch
			{
				// dont want to raise errors now 
				// so ignore especially threadabortexception!!
			}
		}

		#endregion
	}
}