WinSock是Windows提供的包含了一系列网络编程接口的套接字程序库，介绍如何把它的非阻塞模式引入到应用程序中。所讨论的通信均为面向连接的通信（TCP）-WinSock contains a series of network programming interface provided by Windows Sockets library, and describes how its non-blocking mode is introduced into the application