多线程计数,怎么保持计数准确的方法

CommonSigleton MyCounter =CommonSigleton.Instance;
  /// <summary>
  /// 线程工作
  /// </summary>
public void DoSomeWork()
{
    ///构造显示字符串
    string results = "";

    ///创建一个Sigleton实例

    System.Threading.Thread.Sleep(100);

    int i = 0;
    while (MyCounter.GetCounter() < 200)
    {
        //保证计数与输出一致，即便计数与输出之间加上时间间隔也会为这块区域加锁，防止其他线程操作
        lock (this)
        {
            ///开始计数
            MyCounter.Add();
            System.Threading.Thread.Sleep(100);
            Thread thread = Thread.CurrentThread;
            results += "线程";
            results += i++.ToString() + "――〉" + thread.Name + " ";
            results += "当前的计数：";
            results += MyCounter.GetCounter().ToString();
            results += "\n";

            Console.WriteLine(results);

            // 清空显示字符串
            results = "";
        }
    }
}

  public void StartMain()
  {

   Thread thread0 = Thread.CurrentThread;

   thread0.Name = "Thread 0";

   Thread thread1 =new Thread(new ThreadStart(DoSomeWork));

   thread1.Name = "Thread 1";

   Thread thread2 =new Thread(new ThreadStart(DoSomeWork));

   thread2.Name = "Thread 2";

   Thread thread3 =new Thread(new ThreadStart(DoSomeWork));

   thread3.Name = "Thread 3";

            thread1.Start();

            thread2.Start();

            thread3.Start();

   ///线程0也只执行和其他线程相同的工作
   DoSomeWork();
  }
 }