C# 中线程的互锁（Interlock），那位大神能帮忙看看

最近在使用Interlock时，出现读值错误，所以写了一个demo，有大神帮忙看看有什么问题。

 namespace ThreadDemo
{
    class Tester
    {
        private int counter = 0;
        static void Main(string[] args)
        {
            //make an instance of this class
            Tester t = new Tester();
            //run outside static Main
            t.DoTest();
            Console.ReadKey();
        }

        private void DoTest()
        {
            Thread t1 = new Thread(new ThreadStart(Incrementer));
            t1.IsBackground = true;
            t1.Name = "ThreadOne";
            t1.Start();
            Console.WriteLine("Started thread {0}",t1.Name);


            Thread t2 = new Thread(new ThreadStart(Incrementer));
            t2.IsBackground = true;
            t2.Name = "ThreadTwo";
            t2.Start();
            Console.WriteLine("Started thread {0}", t2.Name);

            t1.Join();
            t2.Join();

            //等待所有的线程都结束
            Console.WriteLine("All my threads are done.");
        }
        //线程调用的函数
        private void Incrementer()
        {
            //Console.WriteLine("Incrementer:{0}",counter);
            try
            {
                while (counter < 10)
                {
                    //使用互锁
                    Interlocked.Increment(ref counter);
                    //线程挂起
                    Thread.Sleep(1);
                    //显示结果
                    Console.WriteLine("Thread {0}.Incrementer:{1}",Thread.CurrentThread.Name,counter);
                }
            }
            catch(ThreadInterruptedException)
            {
                Console.WriteLine("Thread {0} Interlocked!Cleaning up ...",Thread.CurrentThread.Name);
            }
            finally
            {
                Console.WriteLine("Thread {0} Exiting.",Thread.CurrentThread.Name);
            }
        }
    }
}

结果显示如下图：

我已经使用Interlocked进行了锁定，为什么线程2在线程1没有结束的时候会改变变量的值，求大神帮忙看看。

如果要让线程2等待线程1完毕后再执行线程2，用lock()不就得了，Interlocked本来就是对lock的引用计数使用的。
你要看你具体想干啥，才能知道你要用啥。

如果你要是想多线程执行counter++的话，直接用lock简单明了。

 private object _lockobj = new object();
            //线程调用的函数
            private void Incrementer()
            {
                //Console.WriteLine("Incrementer:{0}",counter);
                try
                {
                    while (true)
                    {
                        //使用互锁
                        lock(_lockobj)
                        {
                            counter++;
                            //线程挂起
                            Thread.Sleep(1);
                            //显示结果
                            Console.WriteLine("Thread {0}.Incrementer:{1}", Thread.CurrentThread.Name, counter);
                            if (counter < 10)
                            {
                                continue;
                            }
                            else
                            {
                                break;
                            }
                        }
                        //Interlocked.Increment(ref counter);
                    }
                }
                catch (ThreadInterruptedException)
                {
                    Console.WriteLine("Thread {0} Interlocked!Cleaning up ...", Thread.CurrentThread.Name);
                }
                finally
                {
                    Console.WriteLine("Thread {0} Exiting.", Thread.CurrentThread.Name);
                }
            }