using System;

using System.Threading;

using System.Threading.Tasks;

using System.Collections.Generic;

​

public class Program

{

    static List<string> guids = new List<string>();

    public async static void Main()

    {

        Task.Run(() => {

            while (true)

            {

                var guid = Guid.NewGuid().ToString();

                guids.Add(guid);

            }

        });

        Task.Run(() => {

            while (true)

            {

                guids.ToArray();

                Thread.Sleep(100);

            }

        }).ContinueWith(t => {

            Console.WriteLine("WE HAVE AN ERROR");

            Console.WriteLine((t.Exception));

        }, TaskContinuationOptions.OnlyOnFaulted).Wait();

    }

}