AsyncPayground.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Punchclock;

namespace AsyncPlayground
{
    class Program
    {
        public static readonly OperationQueue queue = new OperationQueue();
        static void Main(string[] args)
        {
            var asyncCls = new ASyncClass();
            for (int i = 0; i < 4; i++)
            {
                asyncCls.DoTasks(i);

            }
            Console.ReadKey();
        }
    }

    public class ASyncClass
    {
        public void DoTasks(int i)
        {
            MainTask(i);
        }

        public async Task MainTask(int i)
        {
            string result = string.Empty;
            if (i % 2 == 0)
            {
                result = await Program.queue.Enqueue(1, "one", () => SubTaskOne());
            }
            else
            {
                result = await Program.queue.Enqueue(1, "two", () => SubTaskTwo());
            }
            Console.WriteLine(result);

        }

        public async Task<string> SubTaskOne()
        {
            Console.WriteLine("SubTask One");
            Thread.Sleep(1);
            return "SubTask One complete";
        }

        public async Task<string> SubTaskTwo()
        {
            Console.WriteLine("SubTask Two");
            Thread.Sleep(100);
            return "SubTask Two complete";
        }
        
        //if you change the Thread.Sleep calls to await Task.Delay() calls, the OperationQueue performs as expected
    }
}