Win32 网络编程模型

比眉伴天荒 2022-08-30 04:12 190阅读 0赞

# 概述 #

我们在进行网络编程时候往往会选择一种方式进行对多个socket进行操作。比如一个socket对应一个线程等

# Select模型 #

这个模式是将若干socket交付给内核去检测是否可读可写或者有异常。

如下代码`HandleClientThreadFunc`就是检测多个socket

#include <iostream>
    #include<WinSock2.h>
    #include<WS2tcpip.h>
    #pragma comment(lib,"Ws2_32.lib")
    #include<vector>
    
    using namespace std;
    
    vector<SOCKET> g_vctSock;//存放socket的数组
    
    //发送读写信息的函数
    void HandleData(SOCKET sockClient) {
        
    
    	//收发数据
    	char buf[MAXBYTE] = {
         0 };
    
    	int iResult = recv(sockClient, buf, MAXBYTE, 0);
    
    	if (iResult > 0)
    		printf("Bytes received: %d   content %s \n", iResult, buf);
    	else if (iResult == 0) {
        
    		printf("Connection closed\n");
    		return;
    	}
    	else {
        
    		printf("recv failed: %d\n", WSAGetLastError());
    		return ;
    	}
    
    
    	char aryBuffSend[] = {
         "server recv ok \r\n" };
    
    	int nRet = send(sockClient, aryBuffSend, sizeof(aryBuffSend), 0);
    
    	if (nRet == SOCKET_ERROR)
    	{
        
    		printf("发送错误\r\n");
    	}
    }
    
    DWORD WINAPI HandleClientThreadFunc(LPVOID lpParam) {
        
    	while (true)
    	{
        
    		//fd_set 这个用于存放要监听的socket
    		fd_set fdRead;
    		//重置fdRead
    		FD_ZERO(&fdRead);
    
    		//todo  此处应该加锁 
    		//此处将要监听的socket放入fdRead
    		for (auto sock : g_vctSock)
    		{
        
    			FD_SET(sock, &fdRead);
    		}
    		//todo  此处应该解锁
    
    		//调用select检测哪些socket可以读，timeval用于设置超时返回
    		timeval tv = {
         3,0 };
    		//交付内核轮训是否可读可写与异常等。返回后会更新传入的fd_set 
    		int nRet = select(fdRead.fd_count, &fdRead,
    		 NULL,//设置监听可写的集合
    		  NULL,//设置异常监听的fd_set 这里不需要
    		   &tv//设置超时
    		   );
    		   
    		//超时就continue
    		if (nRet == 0 || nRet == SOCKET_ERROR)
    		{
        
    			continue;
    		}
    		//运行到这fdRead只会剩下可读socket在里面
    		
    		//处理数据 这里的socket是可读的证明有信息 下面两种方式任选
    		/*for (auto itr = g_vctSock.begin(); itr!= g_vctSock.end(); itr++)
    		{
    			if (FD_ISSET(*itr,&fdRead))
    			{
    				HandleData(*itr);
    			}
    		}*/
    		for (size_t i = 0; i < fdRead.fd_count; i++)
    		{
        
    			SOCKET sock = fdRead.fd_array[i];
    			//处理信息
    			HandleData(sock);
    		}
    
    		
    	}
    }
    
    int main()
    {
        
    
    
    
       //start 常规初始化代码 start 
    	WORD wVersionRequested;
    	WSADATA wsaData;
    	int err;
    
    	/* Use the MAKEWORD(lowbyte, highbyte) macro declared in Windef.h */
    	wVersionRequested = MAKEWORD(2, 2);
    
    	err = WSAStartup(wVersionRequested, &wsaData);
    	if (err != 0) {
        
    		/* Tell the user that we could not find a usable */
    		/* Winsock DLL.                                  */
    		printf("WSAStartup failed with error: %d\n", err);
    		return 1;
    	}
    
    	/* Confirm that the WinSock DLL supports 2.2.*/
    	/* Note that if the DLL supports versions greater    */
    	/* than 2.2 in addition to 2.2, it will still return */
    	/* 2.2 in wVersion since that is the version we      */
    	/* requested.                                        */
    
    	if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2) {
        
    		/* Tell the user that we could not find a usable */
    		/* WinSock DLL.                                  */
    		printf("Could not find a usable version of Winsock.dll\n");
    		WSACleanup();
    		return 1;
    	}
    	else
    		printf("The Winsock 2.2 dll was found okay\n");
       //en d常规初始化代码 end
    
    	//创建socket
    	SOCKET sockServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    	if (sockServer == INVALID_SOCKET)
    	{
        
    		printf("socket创建失败 ，请重启\r\n");
    		return 0;
    	}
    	//绑定端口
    	sockaddr_in siServer;
    	siServer.sin_family = AF_INET;
    	siServer.sin_port = htons(0x5566);
    	int nRet = InetPton(AF_INET, "127.0.0.1", &siServer.sin_addr.s_addr);
    	//等于1表示成功
    	if (nRet != 1)
    	{
        
    		printf("错误");
    		return 0;
    	}
    
    	nRet = bind(sockServer, (sockaddr*)&siServer, sizeof(siServer));
    
    
    	if (nRet == SOCKET_ERROR)
    	{
        
    		printf("绑定端口失败，请重启 \r\n");
    		return 0;
    	}
    	//监听
    	nRet = listen(sockServer, SOMAXCONN);
    	if (nRet != 0)
    	{
        
    		printf("绑定端口失败，请重启 \r\n");
    		return 0;
    	}
    	//等候连接
    	int len;
    	sockaddr_in si;
    
    	int nLen = sizeof(si);
    
    	HANDLE handle = CreateThread(NULL, 0, HandleClientThreadFunc, NULL, 0, NULL);
    
    	while (true)
    	{
        
    		SOCKET  resultSocket = accept(sockServer, (sockaddr*)&si, &nLen);
    		if (resultSocket == INVALID_SOCKET)
    		{
        
    			printf("accept失败，请重启 \r\n");
    			continue;
    		}
    		g_vctSock.push_back(resultSocket);
    		
    	}
    
    	CloseHandle(handle);
    	//关闭自身
    	closesocket(sockServer);
    
    	/* The Winsock DLL is acceptable. Proceed to use it. */
    
    	/* Add network programming using Winsock here */
    
    	/* then call WSACleanup when done using the Winsock dll */
    
    	WSACleanup();
    }

不过上面你会发现select不能进行接收socket连接信息。

# 异步选择 #

[WSAAsyncSelect 文档][WSAAsyncSelect]

其核心代码：  
(1) 创建服务端的套接字，并声明要监听套接字哪些事件

//创建socket
    		SOCKET sockServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    		if (sockServer == INVALID_SOCKET)
    		{
        
    			printf("socket创建失败 ，请重启\r\n");
    			return 0;
    		}
    		//绑定端口
    		sockaddr_in siServer;
    		siServer.sin_family = AF_INET;
    		siServer.sin_port = htons(0x5567);
    		int nRet = InetPton(AF_INET, "127.0.0.1", &siServer.sin_addr.s_addr);
    		//等于1表示成功
    		if (nRet != 1)
    		{
        
    			printf("错误");
    			return 0;
    		}
    
    		nRet = bind(sockServer, (sockaddr*)&siServer, sizeof(siServer));
    		
    		nRet=listen(sockServer,SOMAXCONN);
    		if (nRet == SOCKET_ERROR)
    		{
        
    			printf("socket创建失败 ，请重启\r\n");
    			return 0;
    		}
    		//为这个WSAAsyncSelect注册对应的事件，有事件时进行回调过程函数，
    		nRet = WSAAsyncSelect(sockServer,//放入监听的sock
    			hWnd,//窗口
    			MY_WM_SOCKMSG,//定义回调的消息
    			FD_ACCEPT | //监听哪些事件
    			FD_CLOSE
    		);
    		
    		if (nRet != 0)
    		{
        
    			printf("WSAEventSelect失败 ，请重启\r\n");
    			return 0;
    		}

(2) 在窗口过程函数中处理消息

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
    {
        
    	switch (message)
    	{
        
    	
    	case MY_WM_SOCKMSG: //前面我们定义的消息
    	{
        
    		//事件的socket对象
    		SOCKET sock = (SOCKET)wParam;
    		//这里获得事件
    		WORD wEvent = WSAGETSELECTEVENT(lParam);
    		//如果当前是接收套接字请求
    		if (wEvent & FD_ACCEPT)
    		{
        
    			//接收连接
    			sockaddr_in si;
    			int nLen = sizeof(si);
    			SOCKET sockClient = accept(sock,(sockaddr*)&si,&nLen);
    			//接收之后再把客户端监听事件也放入
    			WSAAsyncSelect(sockClient,//注册的sockServer
    				hWnd,//窗口
    				MY_WM_SOCKMSG,//定义回调的消息
    				FD_READ |
    				FD_CLOSE
    			);
    		}
    		else if (wEvent & FD_READ)
    		{
        
    			//处理客户端发来的信息
    			HandleData(sock);
    		}
    		else if (wEvent & FD_CLOSE)
    		{
        
    			OutputDebugString("close socket port ");
    
    		}
    		printf("");
    	}
    	
    }

完整的代码如下：

// TestAsyncSelect.cpp : 定义应用程序的入口点。
    //
    
    #include "framework.h"
    #include "TestAsyncSelect.h"
    #include<WinSock2.h>
    #include<WS2tcpip.h>
    #pragma comment(lib,"Ws2_32.lib")
    #include<vector>
    #define MY_WM_SOCKMSG WM_USER+1
    
    #define MAX_LOADSTRING 100
    
    // 全局变量:
    HINSTANCE hInst;                                // 当前实例
    WCHAR szTitle[MAX_LOADSTRING];                  // 标题栏文本
    WCHAR szWindowClass[MAX_LOADSTRING];            // 主窗口类名
    
    // 此代码模块中包含的函数的前向声明:
    ATOM                MyRegisterClass(HINSTANCE hInstance);
    BOOL                InitInstance(HINSTANCE, int);
    LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
    INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);
    
    void HandleData(SOCKET sockClient) {
        
    
    	//收发数据
    	char buf[MAXBYTE] = {
         0 };
    
    	int iResult = recv(sockClient, buf, MAXBYTE, 0);
    
    	if (iResult > 0)
    		printf("Bytes received: %d   content %s \n", iResult, buf);
    	else if (iResult == 0) {
        
    		printf("Connection closed\n");
    		return;
    	}
    	else {
        
    		printf("recv failed: %d\n", WSAGetLastError());
    		return;
    	}
    
    
    	char aryBuffSend[] = {
         "server recv ok \r\n" };
    
    	int nRet = send(sockClient, aryBuffSend, sizeof(aryBuffSend), 0);
    
    	if (nRet == SOCKET_ERROR)
    	{
        
    		printf("发送错误\r\n");
    	}
    }
    
    int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
    	_In_opt_ HINSTANCE hPrevInstance,
    	_In_ LPWSTR    lpCmdLine,
    	_In_ int       nCmdShow)
    {
        
    	UNREFERENCED_PARAMETER(hPrevInstance);
    	UNREFERENCED_PARAMETER(lpCmdLine);
    
    
    
    	WORD wVersionRequested;
    	WSADATA wsaData;
    	int err;
    
    	/* Use the MAKEWORD(lowbyte, highbyte) macro declared in Windef.h */
    	wVersionRequested = MAKEWORD(2, 2);
    
    	err = WSAStartup(wVersionRequested, &wsaData);
    	if (err != 0) {
        
    		/* Tell the user that we could not find a usable */
    		/* Winsock DLL.                                  */
    		printf("WSAStartup failed with error: %d\n", err);
    		return 1;
    	}
    
    	/* Confirm that the WinSock DLL supports 2.2.*/
    	/* Note that if the DLL supports versions greater    */
    	/* than 2.2 in addition to 2.2, it will still return */
    	/* 2.2 in wVersion since that is the version we      */
    	/* requested.                                        */
    
    	if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2) {
        
    		/* Tell the user that we could not find a usable */
    		/* WinSock DLL.                                  */
    		printf("Could not find a usable version of Winsock.dll\n");
    		WSACleanup();
    		return 1;
    	}
    	else
    		printf("The Winsock 2.2 dll was found okay\n");
    
    
    
    	// TODO: 在此处放置代码。
    
    	// 初始化全局字符串
    	LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    	LoadStringW(hInstance, IDC_TESTASYNCSELECT, szWindowClass, MAX_LOADSTRING);
    	MyRegisterClass(hInstance);
    
    	// 执行应用程序初始化:
    	if (!InitInstance(hInstance, nCmdShow))
    	{
        
    		return FALSE;
    	}
    
    	HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_TESTASYNCSELECT));
    
    	MSG msg;
    
    	// 主消息循环:
    	while (GetMessage(&msg, nullptr, 0, 0))
    	{
        
    		if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
    		{
        
    			TranslateMessage(&msg);
    			DispatchMessage(&msg);
    		}
    	}
    
    	/* The Winsock DLL is acceptable. Proceed to use it. */
    
    	/* Add network programming using Winsock here */
    
    	/* then call WSACleanup when done using the Winsock dll */
    
    	WSACleanup();
    	return (int)msg.wParam;
    }
    
    
    
    //
    //  函数: MyRegisterClass()
    //
    //  目标: 注册窗口类。
    //
    ATOM MyRegisterClass(HINSTANCE hInstance)
    {
        
    	WNDCLASSEXW wcex;
    
    	wcex.cbSize = sizeof(WNDCLASSEX);
    
    	wcex.style = CS_HREDRAW | CS_VREDRAW;
    	wcex.lpfnWndProc = WndProc;
    	wcex.cbClsExtra = 0;
    	wcex.cbWndExtra = 0;
    	wcex.hInstance = hInstance;
    	wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_TESTASYNCSELECT));
    	wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);
    	wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    	wcex.lpszMenuName = MAKEINTRESOURCEW(IDC_TESTASYNCSELECT);
    	wcex.lpszClassName = szWindowClass;
    	wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));
    
    	return RegisterClassExW(&wcex);
    }
    
    //
    //   函数: InitInstance(HINSTANCE, int)
    //
    //   目标: 保存实例句柄并创建主窗口
    //
    //   注释:
    //
    //        在此函数中，我们在全局变量中保存实例句柄并
    //        创建和显示主程序窗口。
    //
    BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
    {
        
    	hInst = hInstance; // 将实例句柄存储在全局变量中
    
    	HWND hWnd = CreateWindowW(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
    		CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, nullptr, nullptr, hInstance, nullptr);
    
    	if (!hWnd)
    	{
        
    		return FALSE;
    	}
    
    	ShowWindow(hWnd, nCmdShow);
    	UpdateWindow(hWnd);
    
    	return TRUE;
    }
    
    //
    //  函数: WndProc(HWND, UINT, WPARAM, LPARAM)
    //
    //  目标: 处理主窗口的消息。
    //
    //  WM_COMMAND  - 处理应用程序菜单
    //  WM_PAINT    - 绘制主窗口
    //  WM_DESTROY  - 发送退出消息并返回
    //
    //
    LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
    {
        
    	switch (message)
    	{
        
    	case WM_CREATE:
    	{
        
    		//创建socket
    		SOCKET sockServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    		if (sockServer == INVALID_SOCKET)
    		{
        
    			printf("socket创建失败 ，请重启\r\n");
    			return 0;
    		}
    		//绑定端口
    		sockaddr_in siServer;
    		siServer.sin_family = AF_INET;
    		siServer.sin_port = htons(0x5567);
    		int nRet = InetPton(AF_INET, "127.0.0.1", &siServer.sin_addr.s_addr);
    		//等于1表示成功
    		if (nRet != 1)
    		{
        
    			printf("错误");
    			return 0;
    		}
    
    		nRet = bind(sockServer, (sockaddr*)&siServer, sizeof(siServer));
    		
    		nRet=listen(sockServer,SOMAXCONN);
    		if (nRet == SOCKET_ERROR)
    		{
        
    			printf("socket创建失败 ，请重启\r\n");
    			return 0;
    		}
    		//为这个sockeSever注册对应的事件
    		//WSAEventSelect()	
    		nRet = WSAAsyncSelect(sockServer,//注册的sockServer
    			hWnd,//窗口
    			MY_WM_SOCKMSG,//定义回调的消息
    			FD_ACCEPT |
    			FD_CLOSE
    		);
    		if (nRet != 0)
    		{
        
    			printf("WSAEventSelect失败 ，请重启\r\n");
    			return 0;
    		}
    		printf("");
    	}
    	case MY_WM_SOCKMSG:
    	{
        
    		SOCKET sock = (SOCKET)wParam;
    		WORD wEvent = WSAGETSELECTEVENT(lParam);
    		
    		if (wEvent & FD_ACCEPT)
    		{
        
    			//接收连接
    			sockaddr_in si;
    			int nLen = sizeof(si);
    			SOCKET sockClient = accept(sock,(sockaddr*)&si,&nLen);
    		
    			WSAAsyncSelect(sockClient,//注册的sockServer
    				hWnd,//窗口
    				MY_WM_SOCKMSG,//定义回调的消息
    				FD_READ |
    				FD_CLOSE
    			);
    		}
    		else if (wEvent & FD_READ)
    		{
        
    			HandleData(sock);
    		}
    		else if (wEvent & FD_CLOSE)
    		{
        
    			OutputDebugString("close socket port ");
    
    		}
    		printf("");
    	}
    	case WM_COMMAND:
    	{
        
    		int wmId = LOWORD(wParam);
    		// 分析菜单选择:
    		switch (wmId)
    		{
        
    		case IDM_ABOUT:
    			DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
    			break;
    		case IDM_EXIT:
    			DestroyWindow(hWnd);
    			break;
    		default:
    			return DefWindowProc(hWnd, message, wParam, lParam);
    		}
    	}
    	break;
    	case WM_PAINT:
    	{
        
    		PAINTSTRUCT ps;
    		HDC hdc = BeginPaint(hWnd, &ps);
    		// TODO: 在此处添加使用 hdc 的任何绘图代码...
    		EndPaint(hWnd, &ps);
    	}
    	break;
    	case WM_DESTROY:
    		PostQuitMessage(0);
    		break;
    	default:
    		return DefWindowProc(hWnd, message, wParam, lParam);
    	}
    	return 0;
    }
    
    // “关于”框的消息处理程序。
    INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
    {
        
    	UNREFERENCED_PARAMETER(lParam);
    	switch (message)
    	{
        
    	case WM_INITDIALOG:
    		return (INT_PTR)TRUE;
    
    	case WM_COMMAND:
    		if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
    		{
        
    			EndDialog(hDlg, LOWORD(wParam));
    			return (INT_PTR)TRUE;
    		}
    		break;
    	}
    	return (INT_PTR)FALSE;
    }

# 事件选择模型 #

#include<WinSock2.h>
    #include<WS2tcpip.h>
    #include<stdio.h>
    
    #pragma comment(lib,"Ws2_32.lib")
    #include<map>
    using namespace std;
    
    void asw();
    
    void HandleData(SOCKET sockClient) {
        
    
    	//收发数据
    	char buf[MAXBYTE] = {
         0 };
    
    	int iResult = recv(sockClient, buf, MAXBYTE, 0);
    
    	if (iResult > 0)
    		printf("Bytes received: %d   content %s \n", iResult, buf);
    	else if (iResult == 0) {
        
    		printf("Connection closed\n");
    		return;
    	}
    	else {
        
    		printf("recv failed: %d\n", WSAGetLastError());
    		return;
    	}
    
    
    	char aryBuffSend[] = {
         "server recv ok \r\n" };
    
    	int nRet = send(sockClient, aryBuffSend, sizeof(aryBuffSend), 0);
    
    	if (nRet == SOCKET_ERROR)
    	{
        
    		printf("发送错误\r\n");
    	}
    }
    
    
    
    int main() {
        
    	WORD wVersionRequested;
    	WSADATA wsaData;
    	int err;
    
    	/* Use the MAKEWORD(lowbyte, highbyte) macro declared in Windef.h */
    	wVersionRequested = MAKEWORD(2, 2);
    
    	err = WSAStartup(wVersionRequested, &wsaData);
    	if (err != 0) {
        
    		/* Tell the user that we could not find a usable */
    		/* Winsock DLL.                                  */
    		printf("WSAStartup failed with error: %d\n", err);
    		return 1;
    	}
    
    	/* Confirm that the WinSock DLL supports 2.2.*/
    	/* Note that if the DLL supports versions greater    */
    	/* than 2.2 in addition to 2.2, it will still return */
    	/* 2.2 in wVersion since that is the version we      */
    	/* requested.                                        */
    
    	if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2) {
        
    		/* Tell the user that we could not find a usable */
    		/* WinSock DLL.                                  */
    		printf("Could not find a usable version of Winsock.dll\n");
    		WSACleanup();
    		return 1;
    	}
    	else
    		printf("The Winsock 2.2 dll was found okay\n");
    
    
    
    
    	asw();
    
    	/* The Winsock DLL is acceptable. Proceed to use it. */
    
    	/* Add network programming using Winsock here */
    
    	/* then call WSACleanup when done using the Winsock dll */
    
    	WSACleanup();
    
    	return EXIT_SUCCESS;
    }
    
    
    void asw() {
        
    	//创建socket
    	SOCKET sockServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    	if (sockServer == INVALID_SOCKET)
    	{
        
    		printf("socket创建失败 ，请重启\r\n");
    		return ;
    	}
    	//绑定端口
    	sockaddr_in siServer;
    	siServer.sin_family = AF_INET;
    	siServer.sin_port = htons(0x5567);
    	int nRet = InetPton(AF_INET, "127.0.0.1", &siServer.sin_addr.s_addr);
    	//等于1表示成功
    	if (nRet != 1)
    	{
        
    		printf("错误");
    		return ;
    	}
    
    	nRet = bind(sockServer, (sockaddr*)&siServer, sizeof(siServer));
    
    	nRet = listen(sockServer, SOMAXCONN);
    	if (nRet == SOCKET_ERROR)
    	{
        
    		printf("socket创建失败 ，请重启\r\n");
    		return ;
    	}
    	WSAEVENT hEvent = WSACreateEvent();
    	WSAEventSelect(sockServer, hEvent, FD_ACCEPT | FD_CLOSE);
    
    	std::map<WSAEVENT, SOCKET> mpSockInfo;
    	mpSockInfo[hEvent] = sockServer;
    
    	while (true)
    	{
        
    		WSAEVENT aryEvents[WSA_MAXIMUM_WAIT_EVENTS] = {
         0 };
    		int nEventCount = 0;
    
    		for (auto sockinfo : mpSockInfo)
    		{
        
    			aryEvents[nEventCount++] = sockinfo.first;
    		}
    
    		//返回值是数组的下标
    		DWORD dwRet = WSAWaitForMultipleEvents(nEventCount, aryEvents, FALSE, 3000, FALSE);
    		//超时返回
    		if (dwRet == WAIT_TIMEOUT)
    		{
        
    			continue;
    		}
    		//获取对应的event的事件
    		WSANETWORKEVENTS ne;
    		WSAEnumNetworkEvents(mpSockInfo[aryEvents[dwRet]], aryEvents[dwRet], &ne);
    
    		//判断事件
    		if (ne.lNetworkEvents & FD_ACCEPT)
    		{
        
    			//接收连接
    			sockaddr_in si;
    			int nLen = sizeof(si);
    			SOCKET sockClient = accept(sockServer, (sockaddr*)&si, &nLen);
    			if (sockClient == INVALID_SOCKET)
    			{
        
    				printf("连接失败 \r\n");
    				continue;
    			}
    
    			WSAEVENT hEvent = WSACreateEvent();
    			WSAEventSelect(sockClient, hEvent, FD_READ | FD_CLOSE);
    			mpSockInfo[hEvent] = sockClient;
    		}
    		else if (ne.lNetworkEvents & FD_READ)
    		{
        
    			HandleData(mpSockInfo[aryEvents[dwRet]]);
    		}
    		else if (ne.lNetworkEvents & FD_ACCEPT)
    		{
        
    
    		}
    
    	}
    }

# IOCP #

> 全称 I/O completion ports

与其它的模型最大的不同点在于不仅可以监听多个io接口，同时还帮你直接处理。

例子：

（1）对于链接：

**其他模型**：有一个远程链接想让绑定到服务器，对于其他模式只是会提示有一个链接进入，此时你需要自行接受完成接收过程。

`IOCP`：不仅会告诉你一个链接进入还直接帮你链接上.

（2）数据读取：

**其他模型**：你有数据可以读取，然后你自行调用相关函数读取

`IOCP`：直接帮你读取好数据返回.

其他略

[IOCP官方文档][IOCP]

// IOCPServiceDemo.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
    //
    #include<WinSock2.h>
    #include<WS2tcpip.h>
    #include<stdio.h>
    #include<Mswsock.h>
    #pragma comment(lib,"Mswsock.lib")
    #pragma comment(lib,"Ws2_32.lib")
    #include<map>
    
    void PostSend(SOCKET sock);
    void PostRecv(SOCKET sock);
    enum IO_EVENT {
        
    	IO_ACCEPT,
    	IO_RECV,
    	IO_SEND
    };
    
    struct CROVERPLAPPED {
        
    	OVERLAPPED m_ov;
    	IO_EVENT m_ioevent;
    	WSABUF m_buf;
    	char aryBuf[MAXBYTE];
    	SOCKET m_socket;
    
    	CROVERPLAPPED(SOCKET sock, IO_EVENT ioEve) :m_socket(sock), m_ioevent(ioEve) {
        
    		memset(&m_ov, 0, sizeof(OVERLAPPED));
    		memset(aryBuf, 0, sizeof(aryBuf));
    		m_buf.buf = aryBuf;
    		m_buf.len = sizeof(aryBuf);
    	}
    
    };
    
    using namespace std;
    void asw();
    
    void PostAccept(const HANDLE hIocp, const SOCKET sockServer);
    
    void HandleData(SOCKET sockClient) {
        
    
    	//收发数据
    	char buf[MAXBYTE] = {
         0 };
    
    	int iResult = recv(sockClient, buf, MAXBYTE, 0);
    
    	if (iResult > 0)
    		printf("Bytes received: %d   content %s \n", iResult, buf);
    	else if (iResult == 0) {
        
    		printf("Connection closed\n");
    		return;
    	}
    	else {
        
    		printf("recv failed: %d\n", WSAGetLastError());
    		return;
    	}
    
    	char aryBuffSend[] = {
         "server recv ok \r\n" };
    
    	int nRet = send(sockClient, aryBuffSend, sizeof(aryBuffSend), 0);
    
    	if (nRet == SOCKET_ERROR)
    	{
        
    		printf("发送错误\r\n");
    	}
    }
    
    
    int main() {
        
    	WORD wVersionRequested;
    	WSADATA wsaData;
    	int err;
    
    	/* Use the MAKEWORD(lowbyte, highbyte) macro declared in Windef.h */
    	wVersionRequested = MAKEWORD(2, 2);
    
    	err = WSAStartup(wVersionRequested, &wsaData);
    	if (err != 0) {
        
    		/* Tell the user that we could not find a usable */
    		/* Winsock DLL.                                  */
    		printf("WSAStartup failed with error: %d\n", err);
    		return 1;
    	}
    
    	/* Confirm that the WinSock DLL supports 2.2.*/
    	/* Note that if the DLL supports versions greater    */
    	/* than 2.2 in addition to 2.2, it will still return */
    	/* 2.2 in wVersion since that is the version we      */
    	/* requested.                                        */
    
    	if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2) {
        
    		/* Tell the user that we could not find a usable */
    		/* WinSock DLL.                                  */
    		printf("Could not find a usable version of Winsock.dll\n");
    		WSACleanup();
    		return 1;
    	}
    	else
    		printf("The Winsock 2.2 dll was found okay\n");
    
    
    
    	asw();
    
    	/* The Winsock DLL is acceptable. Proceed to use it. */
    
    	/* Add network programming using Winsock here */
    
    	/* then call WSACleanup when done using the Winsock dll */
    
    	WSACleanup();
    
    	return EXIT_SUCCESS;
    }
    
    void asw() {
        
    	//创建socket
    	SOCKET sockServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    
    	if (sockServer == INVALID_SOCKET)
    	{
        
    		printf("socket创建失败 ，请重启\r\n");
    		return;
    	}
    	//绑定端口
    	sockaddr_in siServer;
    	siServer.sin_family = AF_INET;
    	siServer.sin_port = htons(0x5567);
    	int nRet = InetPton(AF_INET, "127.0.0.1", &siServer.sin_addr.s_addr);
    	//等于1表示成功
    	if (nRet != 1)
    	{
        
    		printf("错误");
    		return;
    	}
    
    	nRet = bind(sockServer, (sockaddr*)&siServer, sizeof(siServer));
    
    	nRet = listen(sockServer, SOMAXCONN);
    
    	if (nRet == SOCKET_ERROR)
    	{
        
    		printf("socket创建失败 ，请重启\r\n");
    		return;
    	}
    
    
    	//注册IOCP对象
    	HANDLE hIocp = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, NULL, 0);
    
    	//注册（关联）socket到iocp
    	HANDLE hRet = CreateIoCompletionPort((HANDLE)sockServer, hIocp, NULL, 0);
    	//创一个请求事件
    	PostAccept(hIocp, sockServer);
    	
    	//轮询状态
    	while (true)
    	{
        
    		DWORD dwBytesTransfer = 0;
    		ULONG_PTR uKey = 0;
    		LPOVERLAPPED pOV;
    		GetQueuedCompletionStatus(hIocp, &dwBytesTransfer, &uKey, &pOV, INFINITE);
    
    		//有请求完成了
    		CROVERPLAPPED *pCr38OV = (CROVERPLAPPED*)pOV;
    
    		switch (pCr38OV->m_ioevent)
    		{
        
    		case IO_ACCEPT:
    			//创建一个接受读取事件
    			PostRecv(pCr38OV->m_socket);
    			//因为事件被消耗了 所以你要重新注册一个事件到IOCP去监听新的链接
    			PostAccept(hIocp, sockServer);
    			break;
    		case IO_RECV:
    			printf("接收数据：%s\r\n",pCr38OV->m_buf.buf);
    			//放置一个发送事件
    			PostSend(pCr38OV->m_socket);
    			break;
    		case IO_SEND:
    			printf("成功发送：%s\r\n", pCr38OV->m_buf.buf);
    			//监听发送事件成功后，重新设置接收事件
    			PostRecv(pCr38OV->m_socket);
    			break;
    		default:
    			break;
    		}
    	}
    
    
    	closesocket(sockServer);
    	WSACleanup();
    
    }
    
    void PostAccept(HANDLE hIocp, SOCKET sockServer)
    {
        
    
    	SOCKET sockClient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    	HANDLE hRet = CreateIoCompletionPort((HANDLE)sockClient, hIocp, NULL, 0);
    
    	char szBuff[MAXBYTE] = {
         0 };
    	DWORD dwByteRecv = 0;
    
    	CROVERPLAPPED* pOV = new CROVERPLAPPED(sockClient, IO_ACCEPT);
    
    	BOOL bRet = AcceptEx(
    		sockServer,
    		sockClient,
    		szBuff,
    		0,
    		sizeof(sockaddr_in) + 16,
    		sizeof(sockaddr_in) + 16,
    		&dwByteRecv,
    		(OVERLAPPED*)pOV
    	);
    
    }
    
    void PostRecv(SOCKET sock)
    {
        
    
    	CROVERPLAPPED* pOV = new CROVERPLAPPED(sock, IO_RECV);
    	DWORD dwBytercv = 0;
    	DWORD dwFlag = 0;
    	WSARecv(
    		sock,
    		&pOV->m_buf,
    		1,
    		&dwBytercv,
    		&dwFlag,
    		(OVERLAPPED*)pOV,
    		NULL
    		);
    
    }
    
    //投递发数据的请求
    void PostSend(SOCKET sock)
    {
        
    
    	CROVERPLAPPED* pOV = new CROVERPLAPPED(sock, IO_SEND);
    	strcpy_s(pOV->aryBuf, "recv ok");
    	DWORD dwBytercv = 0;
    	DWORD dwFlag = 0;
    	WSASend(sock,&pOV->m_buf,1,&dwBytercv,dwFlag,(LPOVERLAPPED)pOV,NULL);
    
    	
    }

[WSAAsyncSelect]: https://docs.microsoft.com/en-us/windows/win32/api/winsock/nf-winsock-wsaasyncselect
[IOCP]: https://docs.microsoft.com/en-us/windows/win32/fileio/i-o-completion-ports