using System;

using System.Threading;

using System.Threading.Tasks;

​

class AsyncAwaitDemo

{

    static void Main()

    {

        var timeBeforeExecutionSync = DateTime.Now;

        var waffleInASink = WeekendToDo();

        var timeAfterExecutionSync = DateTime.Now;

        Console.WriteLine("Sync Duration: {0}", timeAfterExecutionSync.Subtract(timeBeforeExecutionSync).TotalSeconds.ToString("#"));

​

        var timeBeforeExecutionAsync = DateTime.Now;

        var waffled = GetSync<Waffle>(WeekendToDoAsync());

        var timeAfterExecutionAsync = DateTime.Now;

        Console.WriteLine("Async Duration: {0}", timeAfterExecutionAsync.Subtract(timeBeforeExecutionAsync).TotalSeconds.ToString("#"));

    }

    public static T GetSync<T>(Task<T> task)

        {

            task.Wait();

            return task.Result;

        }

     /*static async Task Main()

    {

        var timeBeforeExecutionSync = DateTime.Now;

        WeekendToDo();

        var timeAfterExecutionSync = DateTime.Now;

        Console.WriteLine("Sync Duration: {0}", timeAfterExecutionSync.Subtract(timeBeforeExecutionSync).TotalSeconds.ToString("#"));

​

        var timeBeforeExecutionAsync = DateTime.Now;

        await WeekendToDoAsync();

        var timeAfterExecutionAsync = DateTime.Now;

        Console.WriteLine("Async Duration: {0}", timeAfterExecutionAsync.Subtract(timeBeforeExecutionAsync).TotalSeconds.ToString("#"));

    }*/

​

    // <-- synchronous code -->

​

    static Waffle WeekendToDo()

    {

        Waffle waffle = MakeWaffle();

        ReplyMum();

        return waffle;

    }

​

    static Waffle MakeWaffle()

    {

        var task = Task.Delay(2000);

        task.Wait();

        return new Waffle();

    }

​

    static void ReplyMum() => Thread.Sleep(3000);

​

    // <-- asynchronous code -->

​

    static async Task<Waffle> WeekendToDoAsync()

    {

        Task<Waffle> waffleTask = MakeWaffleAsync();

        ReplyMum();

        Console.WriteLine("replied to Mum");

        Waffle waffle = await waffleTask;

        Console.WriteLine("waffleTask completed");

        return waffle;

    }

​

    static async Task<Waffle> MakeWaffleAsync()

    {

        var task = Task.Delay(2000);

        await task;

        return new Waffle();

    }

}

​

class Waffle {}