using System;

using System.Collections.Generic;

using System.Reflection;

using System.Threading.Tasks;

​

public class Program

{

    static Random rnd = new Random();

    public static async Task Main()

    {

        Console.WriteLine("[GLOBAL] start");

        var names = new List<string>{"item1", "item2", "item3"};

        await Task.Run(() => Parallel.ForEach(names, item => 

                         {

                             var delay = rnd.Next(500,2000);

                             Console.WriteLine($"start {item} - {delay}");

                             Task.Delay(delay).GetAwaiter().GetResult();

                             Console.WriteLine($"end {item}");

                         }));

        Console.WriteLine("[GLOBAL] end");

    }

}