//Rextester.Program.Main is the entry point for your code. Don't change it.

//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

​

using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading;

using System.Threading.Tasks;

using System.Text.RegularExpressions;

​

namespace Rextester

{

    public class Program

    {   

        public static void Main(string[] args)

        {

            new Test().Do1();

        }

    }

    public class Test

    {

        private int a;

        public async Task Do1()

        {

            a = 0;

            Console.WriteLine("Test 1: " + a);

            _ = Do2();

            Console.WriteLine("Test 2: " + a);

            a = 0;

            Console.WriteLine("Test 3: " + a);

            _ = Do3();

            Console.WriteLine("Test 4: " + a);

            a = 0;

            Console.WriteLine("Test 5: " + a);

            await Do3();

            Console.WriteLine("Test 6: " + a);

        }

        public async Task Do2()

        {

            _ = Task.Run(() => {

                for(int i = 0; i < 99999999; i++)

                    a = i;

            });

        }

        public async Task Do3()

        {

            await Task.Run(() => {

                for(int i = 0; i < 99999999; i++)

                    a = i;

            });

        }

    }

}