Introduction - If you have any usage issues, please Google them yourself
IOCP (I/O Completion Port, I/O completion ports) is the best kind of performance I/O model. It is the application uses the thread pool handle asynchronous I/O requests of a mechanism. In dealing with multiple concurrent asynchronous I/O request, the previous models are receiving requests to create a thread to answer the request. So there is a lot of threads running in parallel on the system. These threads are runnable, Windows takes a lot of time during kernel thread context switches, and not much time is spent on running the thread. Plus the cost of creating a new thread is relatively large, so resulting in low efficiency.