多线程与聊天室程序的编写，多线程应用中容易出现的问题。互斥对象的讲解，如何采用互斥对象来实现多线程的同步。如何利用命名互斥对象保证应用程序只有一个实例运行。-Multithreaded program written with the chat room, multi-threaded applications prone to problems. Mutex object to explain how to use mutex objects to multi-thread synchroni