c#的旗语锁定的代码，看不懂啊

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Diagnostics;
namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int threadCount = 2;            int semaphoreCount = 1;            Semaphore semaphore = new Semaphore(semaphoreCount, semaphoreCount);
            　　　　　　　　　　            Thread[] threads = new Thread[threadCount];            for (int i = 0; i < threadCount; i++)
            {                threads[i] = new Thread(ThreadMain);
                                          threads[i].Start(semaphore);            }            for (int i = 0; i < threadCount; i++)
            {                threads[i].Join();            }            Console.WriteLine("All threads finished");
            Console.ReadLine();
        }
        static void ThreadMain(object o){        Semaphore semaphore = o as Semaphore;        Trace.Assert(semaphore != null, "o must be a Semaphore type");        bool isCompleted = false;        while (!isCompleted)        {        if (semaphore.WaitOne(600, false))
                    {         try        {        Console.WriteLine("Thread {0} locks the sempahore",        Thread.CurrentThread.ManagedThreadId);        Thread.Sleep(2000);        }        finally        {        semaphore.Release();            Console.WriteLine("Thread {0} releases the semaphore",            Thread.CurrentThread.ManagedThreadId);            isCompleted = true;            }}else{Console.WriteLine("Timeout for thread {0}; wait again",Thread.CurrentThread.ManagedThreadId);}}}}}谁能给细致的讲讲语句的运行原理