C# .NET/Mono -- Quick template for using a ThreadPool

ThreadPoolTemplate.cs

private struct Context
{
	public string val;
	public ManualResetEvent doneEvent;
}

private void FunctionOnContext(object context){
	Context c = (Context)context;

	lock (resultList) {
		resultList.Add (new Result(c.val));
	}

	c.doneEvent.Set ();
}

private void doThreadPool(List<T> things)
{
	ManualResetEvent[] doneEvents = new ManualResetEvent[things.Count];
	resultList = new List<Result> ();

	int i = 0;
	foreach (var thing in things)
	{
		doneEvents[i] = new ManualResetEvent(false);

		Context context = new Context {
			val = thing,
			doneEvent = doneEvents [i]
		};

		ThreadPool.QueueUserWorkItem (
			new WaitCallback (FunctionOnContext),
			context
		);

		i++;
	}

	WaitHandle.WaitAll (doneEvents);
}