重叠模型的基本设计原理便是让应用程序使用一个重叠的数据结构，一次投递一个或多个 Winsock I/O请求。针对那些提交的请求，在它们完成之后，应用程序可为它们提供服务。-The basic design principle of superposition model is to let applications use an overlapping of the data structure, a drop of one or more Winsock I/O requests. For those requests submitted in their complete, the application can provide them with services.