重叠I/O提供了更好的系统性能。

它允许应用程序使用重叠数据结构一次投递一个或者多个异步I/O请求。

提交的I/O请求完成之后，与之关联的重叠数据结构中的事件对象受信。然后，使用WSAGetOverlappedResult函数获取重叠操作结果。

-Overlapped I/O to provide better system performance. It allows the application to use the the overlap data structure once delivery of one or more asynchronous I/O requests. To submit an I/O request is completed, the overlap in the data structure of the associated event object fiduciary. Then, to use WSAGetOverlappedResult function to get the results of overlapping operations.