using System;

using System.Collections.Generic;

using System.Threading;

​

public class Program

{

    static object valueLocker = new Object();

    static List<int> uidList;

    static int takeuid = -1;

    static int countThreads = 0;

    public static void Main()

    {

        for (;;) { 

        Console.WriteLine("Hello World");

        uidList = new List<int>();

        uidList.Add(0);

        uidList.Add(1);

        uidList.Add(2);

        uidList.Add(3);

        uidList.Add(4);

        //... N

        for (int i = 0; i < 10; i++)

        {

            Thread thread = new Thread(TakeUidThread);

            thread.Start();

        }

        //main thread check every 0.5 sec when threads finished

        while (countThreads < 10)

        {

            Thread.Sleep(500);

        }

        Console.WriteLine("All threads finished");

        }

    }

    public static void TakeUidThread() 

    {

        var localuid = -1;

​

            while (localuid < uidList.Count)

            {

                // thread takes free uid

                lock (valueLocker)

                {

                    takeuid++;

                    localuid = takeuid;

                }

​

                if (localuid < uidList.Count && localuid != -1)

                {

                    DoSomeJob(uidList[localuid]);

                }

​

            }

            //thread inc countThreads at end

            lock (valueLocker)

            {

                countThreads++;

            }

    }

    private static void DoSomeJob(int uid)

    {

    }

}