I/OCompletionportsC++AndThreadpools

I/O Completion Ports（I/OCP）是Windows操作系统提供的一种高效的异步IO事件处理机制，它可以通过监控文件句柄、套接字等I/O操作，实现系统的可扩展性和高并发性。Threadpools则是一种线程池工具，是一组预先创建的线程，用于执行多个任务，从而提高系统的性能。

在C++中，可以通过I/OCP和Threadpools的结合来实现高效的IO事件处理。以下是示例代码：

#include <Windows.h>
#include <iostream>
#pragma comment(lib, "Ws2_32.lib")

#define DATA_BUFSIZE 8192

struct IO_DATA {
    OVERLAPPED ov;
    WSABUF wsaBuf;
    CHAR buff[DATA_BUFSIZE];
    int nBufLen;
};

class IOCP {
    private:
        HANDLE compPort;
        DWORD dwThreadId;
        CRITICAL_SECTION cs;
    public:
        IOCP() {
            compPort = NULL;
            dwThreadId = 0;
            InitializeCriticalSection(&cs);
        }
        ~IOCP() {
            DeleteCriticalSection(&cs);
            if(compPort) CloseHandle(compPort);
        }
        bool bind(HANDLE handle) {
            if(compPort == NULL) {
                compPort = CreateIoCompletionPort(handle, NULL, 0, 0);
            } else {
                CreateIoCompletionPort(handle, NULL, 0, 0);
            }
            if(compPort == NULL) return false;
            InitializeCriticalSection(&cs);
            return true;
        }
        bool addClient(HANDLE handle) {
            if(compPort) {
                EnterCriticalSection(&cs);
                CreateIoCompletionPort(handle, compPort, 0, 0);
                LeaveCriticalSection(&cs);
                return true;
            } else {
                return false;
            }
        }
        bool getCompletion(DWORD* pdwTransferred, ULONG_PTR* pCompKey, LPOVERLAPPED* ppOverlapped, DWORD dwMilliseconds = INFINITE) {
            if(compPort == NULL) return false;
            DWORD dwBytesTransfered = 0;
            return GetQueuedCompletionStatus(comp