using System;

using System.Threading.Tasks;

using System.Diagnostics;

​

public class Program

{

    private static Task<int> NOP() {

        return Task<int>.FromResult(3);

    }

    private static async Task<int> CascadeAwait() {

        return await NOP();

    }

​

    private static Task<int> ReturnTask() {

        return NOP();

    }

    public async static void Main()

    {

        Stopwatch sw = new Stopwatch();

​

        int i;

        // JIT warmup

        sw.Restart();

        for (i = 10; i > 0; --i) {

            await ReturnTask();

            await CascadeAwait();

        }

        sw.Stop();

​

        sw.Restart();

        for (i = 1000; i > 0; --i) {

            await CascadeAwait();

        }

        sw.Stop();

        Console.WriteLine("CascadeAwait: " + sw.ElapsedTicks);

​

        sw.Restart();

        for (i = 1000; i > 0; --i) {

            await ReturnTask();

        }

        sw.Stop();

        Console.WriteLine("ReturnTask: " + sw.ElapsedTicks);

    }

}