race condition (fixed)

using System;
using System.Threading;
namespace RaceCondition
{
    class Program
    {
        static object locker = new object();
        private static int counter;

        static void Main(string[] args)
        {
            new Thread(PrintStar).Start();
            new Thread(PrintPlus).Start();

            Console.WriteLine();
        }

        static void PrintStar()
        {
            lock (locker) // Thread safe code
            {
                for (counter = 0; counter < 5; counter++)
                {
                    Console.Write(" *(" + counter + ")\t");
                }
            }
        }

        static void PrintPlus()
        {
            lock (locker) // Thread safe code
            {
                for (counter = 0; counter < 5; counter++)
                {
                    Console.Write(" +(" + counter + ")\t");
                }
            }
        }
    }
}