帮我写一个IOCP程序

IOCP（Input/Output Completion Ports）是一种高效的异步I/O技术，可以用于处理大量的并发网络I/O请求。下面是一个简单的IOCP程序示例：

#include <WinSock2.h>
#include <Windows.h>
#include <iostream>

#define MAX_THREADS 10
#define BUFFER_SIZE 1024

DWORD WINAPI WorkerThread(LPVOID lpParameter);

int main()
{
    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        std::cout << "Failed to initialize Winsock.\n";
        return 1;
    }

    // Initialize completion port
    HANDLE completionPort = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
    if (completionPort == NULL) {
        std::cout << "Failed to create completion port.\n";
        return 1;
    }

    // Create worker threads
    for (int i = 0; i < MAX_THREADS; ++i) {
        HANDLE thread = CreateThread(NULL, 0, WorkerThread, completionPort, 0, NULL);
        if (thread == NULL) {
            std::cout << "Failed to create worker thread.\n";
            return 1;
        }
        CloseHandle(thread);
    }

    // Create listen socket
    SOCKET listenSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (listenSocket == INVALID_SOCKET) {
        std::cout << "Failed to create listen socket.\n";
        return 1;
    }

    // Bind listen socket
    sockaddr_in serverAddress;
    serverAddress.sin_family = AF_INET;
    serverAddress.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
    serverAddress.sin_port = htons(12345);
    if (bind(listenSocket, (sockaddr*)&serverAddress, sizeof(serverAddress)) == SOCKET_ERROR) {
        std::cout << "Failed to bind listen socket.\n";
        return 1;
    }

    // Listen on listen socket
    if (listen(listenSocket, SOMAXCONN) == SOCKET_ERROR) {
        std::cout << "Failed to listen on listen socket.\n";
        return 1;
    }

    // Accept incoming connections and associate them with completion port
    while (true) {
        SOCKET clientSocket = accept(listenSocket, NULL, NULL);
        if (clientSocket == INVALID_SOCKET) {
            std::cout << "Failed to accept new connection.\n";
            continue;
        }

        // Associate client socket with completion port
        if (CreateIoCompletionPort((HANDLE)clientSocket, completionPort, (ULONG_PTR)clientSocket, 0) == NULL) {
            std::cout << "Failed to associate client socket with completion port.\n";
            closesocket(clientSocket);
            continue;
        }
    }

    WSACleanup();
    return 0;
}

DWORD WINAPI WorkerThread(LPVOID lpParameter)
{
    HANDLE completionPort = (HANDLE)lpParameter;

    while (true) {
        DWORD numBytesTransferred = 0;
        ULONG_PTR completionKey = 0;
        LPOVERLAPPED overlapped = NULL;

        // Get the next completed I/O operation
        if (GetQueuedCompletionStatus(completionPort, &numBytesTransferred, &completionKey, &overlapped, INFINITE) == FALSE) {
            std::cout << "Failed to get queued completion status.\n";
            continue;
        }

        // Check if I/O operation was a socket accept
        if (completionKey == 0) {
            SOCKET clientSocket = WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, 0, WSA_FLAG_OVERLAPPED);
            if (clientSocket == INVALID_SOCKET) {
                std::cout << "Failed to create client socket.\n";
                continue;
            }

            // Associate client socket with completion port
            if (CreateIoCompletionPort((HANDLE)clientSocket, completionPort, (ULONG_PTR)clientSocket, 0) == NULL) {
                std::cout << "Failed to associate client socket with completion port.\n";
                closesocket(clientSocket);
                continue;
            }

            // Post a new accept operation on the client socket
            DWORD flags = 0;
            WSABUF dataBuf;
            dataBuf.len = 0;
            dataBuf.buf = NULL;
            OVERLAPPED* overlapped = new OVERLAPPED();
            memset(overlapped, 0, sizeof(OVERLAPPED));
            if (WSAAccept(clientSocket, NULL, NULL, NULL, 0, &dataBuf, overlapped) == SOCKET_ERROR) {
                int errorCode = WSAGetLastError();
                if (errorCode != WSA_IO_PENDING) {
                    std::cout << "Failed to post accept operation on client socket.\n";
                    delete overlapped;
                    closesocket(clientSocket);
                    continue;
                }
            }
        }
    }

    return 0;
}

这个程序创建了一个IOCP并创建了若干个工作线程，每个工作线程从IOCP获取完成的I/O请求并处理它们。主线程创建了一个监听套接字并在循环中接受新的连接请求，将每个新的客户端套接字与IOCP关联，以便在工作线程中处理它们。在工作线程中，如果获取到的完成I/O请求是一个socket accept请求，它会在客户端套接字上发起一个新的accept操作。