.NET Fiddle

CSharp · Console

/Program.cs

using System.Collections.Concurrent;
using System.Threading;

namespace Samples.Console
{
    public class Program
    {
        public static void Main(string[] args)
        {
            Thread thread1 = new Thread(() => StaticField.StaticFieldTest());
            Thread thread2 = new Thread(() => StaticField.StaticFieldTest());

            thread1.Start();
            thread2.Start();

			Thread.Sleep(1000);
        }

        public class StaticField
        {
            public static readonly ConcurrentDictionary<string, string> _dic = InitDictionary();

            public static void StaticFieldTest()
            {
                System.Console.WriteLine("Start Running...");

                _dic.TryAdd(string.Empty, string.Empty);
                _dic.TryAdd(string.Empty, string.Empty);
                _dic.TryAdd(string.Empty, string.Empty);
            }

            public static ConcurrentDictionary<string, string> InitDictionary()
            {
                System.Console.WriteLine("The Dictionary has been initialized now");
                Thread.Sleep(500);
                return new ConcurrentDictionary<string, string>();
            }
        }
    }
}