using System;

using System.Collections.Generic;

using System.Threading.Tasks;

using System.Threading;

using System.Diagnostics;

public class Program

{

    public static void Main()

    {

        int x = 0;

        int y = 0;

        int z = 0;

        int b = 0;

        List<Action> actions = new List<Action>

        {

            () => x = LongCalculation(123),

            () => y = LongCalculation2(345),

            () => z = LongCalculation3(678),

            () => b = LongCalculation4(910)

        };

        Stopwatch sw = Stopwatch.StartNew();

        Parallel.ForEach(actions, x => x.Invoke());

        sw.Stop();

        Console.WriteLine("x="+x+", y="+y+", z="+z+", b="+b);

        Console.WriteLine("elapsed time="+sw.ElapsedMilliseconds+" ms");

    }

    private static int LongCalculation(int i)

    {

        Thread.Sleep(100);

        return i;

    }

    private static int LongCalculation2(int i)

    {

        Thread.Sleep(100);

        return i;

    }

    private static int LongCalculation3(int i)

    {

        Thread.Sleep(100);

        return i;

    }

    private static int LongCalculation4(int i)

    {

        Thread.Sleep(100);

        return i;

    }

}