服务端升级为select模型处理多客户端2

对fd_set的理解，可以参考下：
https://www.cnblogs.com/wuyepeng/p/9745573.html

int select(int nfds, fd_set* readset, fd_set* writeset, fe_set* exceptset, struct timeval* timeout);

参数：

nfds 需要检查的文件描述字个数(集合中最大描述符+1)
readset 用来检查可读性的一组文件描述字。
writeset 用来检查可写性的一组文件描述字。
exceptset 用来检查是否有异常条件出现的文件描述字。(注：错误不包括在异常条件之内)
timeout 超时，填NULL为阻塞，填0为非阻塞，其他为一段超时时间

返回值：

返回fd的总数，错误时返回SOCKET_ERROR

select对集合进行筛选，返回时，只保留符合状态的描述符
----------------------------------------------------------------------------------------
fd_set fdset;
FD_ZERO(&fdset);
FD_SET(1, &fdset); //将套接字1加入 fdset集合
FD_SET(2, &fdset); //将套接字2加入 fdset集合
FD_SET(3, &fdset); //将套接字3加入 fdset集合
FD_SET(7, &fdset); //将套接字7加入 fdset集合

FD_CLR(3, &fdset); //将套接字3从 fdset 集合移除，fdset.fdReadd_array[2]就被清除了，
数组后面的数据依次往前提，即7被放到了fd_array[2]

服务端：

//vc的第一套socket，第二套socket，可能存在冲突

#define WIN32_LEAN_AND_MEAN
#define  _WINSOCK_DEPRECATED_NO_WARNINGS //也可以放到工程属性，预处理中

#include <windows.h>
#include <WinSock2.h>
#include <stdio.h>
#include <vector>

#pragma comment(lib, "ws2_32.lib")

enum CMD
{
    CMD_LOGIN,
    CMD_LOGIN_RET,
    CMD_LOGOUT,
    CMD_LOGOUT_RET,
    CMD_ERROR
};


struct DataHeader
{
    int dataLength;
    CMD    cmd;
};

struct Login :public DataHeader
{
    Login()
    {
        dataLength = sizeof(Login);
        cmd = CMD_LOGIN;
    }
    char userName[32];
    char passWord[32];
};

struct LoginResult :public DataHeader
{
    LoginResult()
    {
        dataLength = sizeof(LoginResult);
        cmd = CMD_LOGIN_RET;
        ret = 0;
    }
    int ret;
};

struct LogOut :public DataHeader
{
    LogOut()
    {
        dataLength = sizeof(LogOut);
        cmd = CMD_LOGOUT;
    }
    char userName[32];
};

struct LogOutResult :public DataHeader
{
    LogOutResult()
    {
        dataLength = sizeof(LogOutResult);
        cmd = CMD_LOGOUT_RET;
        ret = 0;
    }
    int ret;
};

int processor(SOCKET _cSock)
{

    //5 接收客户端数据
    char szRecv[1024] = {};

    int nLen = recv(_cSock, szRecv, sizeof(DataHeader), 0);
    if (nLen <= 0)
    {
        printf("客户端%d已退出。\n", _cSock);
        return -1;
    }

    DataHeader* pHeader = (DataHeader*)szRecv;

    switch (pHeader->cmd)
    {
    case CMD_LOGIN:
    {
        recv(_cSock, szRecv + sizeof(DataHeader), pHeader->dataLength - sizeof(DataHeader), 0);
        Login *pLogin = (Login*)szRecv;
        printf("客户端%d,cmd logint,user:%s,password:%s\n", _cSock, pLogin->userName, pLogin->passWord);
        //----------------------------
        //----------------------------
        LoginResult longinRet = {};
        send(_cSock, (const char*)&longinRet, sizeof(LoginResult), 0);
    }
    break;
    case CMD_LOGOUT:
    {

        recv(_cSock, szRecv + sizeof(DataHeader), pHeader->dataLength - sizeof(DataHeader), 0);
        LogOut *pLogOut = (LogOut*)szRecv;
        printf("客户端%d,cmd logout,user:%s\n", _cSock, pLogOut->userName);
        //----------------------------
        LogOutResult logOutRet = {};
        send(_cSock, (const char*)&logOutRet, sizeof(LogOutResult), 0);
    }
    break;
    default:
    {
        //剩余的垃圾数据是否要读取出来？
        if (pHeader->dataLength >0)
        {
            recv(_cSock, szRecv + sizeof(DataHeader), pHeader->dataLength - sizeof(DataHeader), 0);
        }

        DataHeader header = {};
        header.cmd = CMD_ERROR;
        header.dataLength = 0;
        send(_cSock, (const char*)&header, sizeof(DataHeader), 0);
    }
    break;
    }

    return 0;
}

std::vector<SOCKET> g_clients;

int main()
{
    //启动Windows socket 2.x环境
    WORD ver = MAKEWORD(2, 2);
    WSADATA dat;
    WSAStartup(ver, &dat);

    //--用Socket API建立简易TCP服务端
    //1.建立一个socket
    SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    //2 bind绑定用于接受客户端连接的网络端口
    sockaddr_in _sin = {};
    _sin.sin_family = AF_INET;
    _sin.sin_port = htons(4567);//host to net unsigned
    _sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    //使用127.0.0.1可以防止外网访问
    //启用本机全部的ip地址可以使用，INADDR_ANY
    if (SOCKET_ERROR == bind(_sock, (sockaddr*)&_sin, sizeof(sockaddr_in)))
    {
        printf("错误，绑定网络端口失败...\n");
    }
    else
    {
        printf("绑定网络端口成功...\n");
    }
    //3 listen 监听网络端口
    if (SOCKET_ERROR == listen(_sock, 5))
    {
        printf("错误，监听网络端口失败...\n");
    }
    else
    {
        printf("监听网络端口成功...\n");
    }



    while (true)
    {
        fd_set fdRead;
        fd_set fdWrite;
        fd_set fdExp;

        FD_ZERO(&fdRead);
        FD_ZERO(&fdWrite);
        FD_ZERO(&fdExp);

        FD_SET(_sock, &fdRead);
        FD_SET(_sock, &fdWrite);
        FD_SET(_sock, &fdExp);
        //接入的客户端socket放入到 可读集合中，通过select来筛选出具有可读状态的socket
        for (size_t n = 0; n<g_clients.size(); n++)
        {
            FD_SET(g_clients[n], &fdRead);
        }

        timeval t = {0,0};
        int ret = select(_sock + 1, &fdRead, &fdWrite, &fdExp, &t);
        if (ret < 0)
        {
            printf("select任务结束。\n");
            break;
        }

        if (FD_ISSET(_sock, &fdRead))
        {
            FD_CLR(_sock, &fdRead);//从集合移除了_sock
            sockaddr_in clientAddr = {};
            int nAddrLen = sizeof(clientAddr);
            SOCKET _cSock = INVALID_SOCKET;

            _cSock = accept(_sock, (sockaddr*)&clientAddr, &nAddrLen);
            if (INVALID_SOCKET == _cSock)
            {
                printf("错误，接受到无效客户端socket...\n");
            }
            else
            {
                g_clients.push_back(_cSock);
                printf("新客户端加入:socket=%d,IP=%s\n", _cSock, inet_ntoa(clientAddr.sin_addr));
            }

        }

        for (size_t n = 0; n<fdRead.fd_count; n++)
        {
            if (-1 == processor(fdRead.fd_array[n]))
            {
                auto iter = find(g_clients.begin(), g_clients.end(), fdRead.fd_array[n]);
                if (iter != g_clients.end())
                {
                    closesocket(*iter);
                    g_clients.erase(iter);
                }
            }
        }


    }

    //6 关闭套接字closesocket
    for (size_t n = 0; n<g_clients.size(); n++)
    {
        closesocket(g_clients[n]);
    }
    closesocket(_sock);


    //清除Windows socket环境
    WSACleanup();
    printf("已退出。\n");
    getchar();
    return 0;
}

 

 

客户端：

#define WIN32_LEAN_AND_MEAN
#define _WINSOCK_DEPRECATED_NO_WARNINGS //也可以放到工程属性，预处理中
//#define _CRT_SECURE_NO_WARNINGS

#include <windows.h>
#include <WinSock2.h>
#include <stdio.h>


#pragma comment(lib, "ws2_32.lib")

enum CMD
{
    CMD_LOGIN,
    CMD_LOGIN_RET,
    CMD_LOGOUT,
    CMD_LOGOUT_RET,
    CMD_ERROR
};

struct DataHeader
{
    int dataLength;
    CMD    cmd;
};

struct Login:public DataHeader
{
    Login()
    {
        dataLength = sizeof(Login);
        cmd = CMD_LOGIN;
    }
    char userName[32];
    char passWord[32];
};

struct LoginResult :public DataHeader
{
    LoginResult()
    {
        dataLength = sizeof(LoginResult);
        cmd = CMD_LOGIN_RET;
        ret = 1;
    }
    int ret;
};

struct LogOut :public DataHeader
{
    LogOut()
    {
        dataLength = sizeof(LogOut);
        cmd = CMD_LOGOUT;
    }
    char userName[32];
};

struct LogOutResult :public DataHeader
{
    LogOutResult()
    {
        dataLength = sizeof(LogOutResult);
        cmd = CMD_LOGOUT_RET;
        ret = 1;
    }
    int ret;
};

int main()
{

    //启动Windows socket 2.x环境
    WORD ver = MAKEWORD(2, 2);
    WSADATA dat;
    WSAStartup(ver, &dat);
    //---------------------------
    //--用Socket API建立简易TCP客户端
    //1 建立一个socket
    SOCKET _sock = INVALID_SOCKET;
    _sock = socket(AF_INET, SOCK_STREAM, 0);
    if (INVALID_SOCKET == _sock)
    {
        printf("错误，建立Socket失败...\n");
    }
    else
    {
        printf("建立Socket成功...\n");
    }
    //2 连接服务器connect
    sockaddr_in _sin = {};
    _sin.sin_family = AF_INET;
    _sin.sin_port = htons(4567);//host to net unsigned
    _sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    int ret = connect(_sock, (sockaddr*)&_sin, sizeof(sockaddr_in));
    if (SOCKET_ERROR == ret)
    {
        printf("错误，连接服务端失败...\n");


        closesocket(_sock);

        //清除Windows socket环境
        WSACleanup();
        printf("已退出。");
        getchar();
        return 0;
    }
    else
    {
        printf("连接服务端成功...\n");
    }

    
    while (true)
    {
        //3输入请求命令
        char cmdBuf[128] = {};
        scanf_s("%s", cmdBuf, 128);
        getchar();
        //4处理请求
        if (0 == strcmp(cmdBuf, "exit"))
        {
            printf("收到exit命令，任务结束。\n");
            break;
        }
        else if(0 == strcmp(cmdBuf, "login"))
        {

            Login login = {};
            strcpy_s(login.userName, "jj");
            strcpy_s(login.passWord, "ww");
            int nSend = send(_sock, (const char*)&login, sizeof(Login), 0);
            printf("send length %d\n", nSend);

            LoginResult cmd_ret = {};
            recv(_sock, (char*)&cmd_ret, sizeof(LoginResult), 0);
            printf("Login result:%d\n", cmd_ret.ret);
        }
        else if (0 == strcmp(cmdBuf, "logout"))
        {
            LogOut log_out = {};
            strcpy_s(log_out.userName, "jj");
            send(_sock, (const char*)&log_out, sizeof(LogOut), 0);

            LogOutResult cmd_ret = {};
            recv(_sock, (char*)&cmd_ret, sizeof(LogOutResult), 0);
            printf("LogOut result:%d\n", cmd_ret.ret);
        }
        else
        {
            printf("wrong cmd, please input cmd again.\n");
        }

    }



    //7 关闭套接字closesocket
    closesocket(_sock);

    //清除Windows socket环境
    WSACleanup();
    printf("已退出");
    getchar();
    return 0;
}

 

//vc的第一套socket，第二套socket，可能存在冲突
#define WIN32_LEAN_AND_MEAN#define  _WINSOCK_DEPRECATED_NO_WARNINGS //也可以放到工程属性，预处理中
#include <windows.h>#include <WinSock2.h>#include <stdio.h>#include <vector>
#pragma comment(lib, "ws2_32.lib")
enum CMD{CMD_LOGIN,CMD_LOGIN_RET,CMD_LOGOUT,CMD_LOGOUT_RET,CMD_ERROR};

struct DataHeader{int dataLength;CMD    cmd;};
struct Login :public DataHeader{Login(){dataLength = sizeof(Login);cmd = CMD_LOGIN;}char userName[32];char passWord[32];};
struct LoginResult :public DataHeader{LoginResult(){dataLength = sizeof(LoginResult);cmd = CMD_LOGIN_RET;ret = 0;}int ret;};
struct LogOut :public DataHeader{LogOut(){dataLength = sizeof(LogOut);cmd = CMD_LOGOUT;}char userName[32];};
struct LogOutResult :public DataHeader{LogOutResult(){dataLength = sizeof(LogOutResult);cmd = CMD_LOGOUT_RET;ret = 0;}int ret;};
int processor(SOCKET _cSock){
//5 接收客户端数据char szRecv[1024] = {};
int nLen = recv(_cSock, szRecv, sizeof(DataHeader), 0);if (nLen <= 0){printf("客户端%d已退出。\n", _cSock);return -1;}
DataHeader* pHeader = (DataHeader*)szRecv;
switch (pHeader->cmd){case CMD_LOGIN:{recv(_cSock, szRecv + sizeof(DataHeader), pHeader->dataLength - sizeof(DataHeader), 0);Login *pLogin = (Login*)szRecv;printf("客户端%d,cmd logint,user:%s,password:%s\n", _cSock, pLogin->userName, pLogin->passWord);//----------------------------//----------------------------LoginResult longinRet = {};send(_cSock, (const char*)&longinRet, sizeof(LoginResult), 0);}break;case CMD_LOGOUT:{
recv(_cSock, szRecv + sizeof(DataHeader), pHeader->dataLength - sizeof(DataHeader), 0);LogOut *pLogOut = (LogOut*)szRecv;printf("客户端%d,cmd logout,user:%s\n", _cSock, pLogOut->userName);//----------------------------LogOutResult logOutRet = {};send(_cSock, (const char*)&logOutRet, sizeof(LogOutResult), 0);}break;default:{//剩余的垃圾数据是否要读取出来？if (pHeader->dataLength >0){recv(_cSock, szRecv + sizeof(DataHeader), pHeader->dataLength - sizeof(DataHeader), 0);}
DataHeader header = {};header.cmd = CMD_ERROR;header.dataLength = 0;send(_cSock, (const char*)&header, sizeof(DataHeader), 0);}break;}
return 0;}
std::vector<SOCKET> g_clients;
int main(){//启动Windows socket 2.x环境WORD ver = MAKEWORD(2, 2);WSADATA dat;WSAStartup(ver, &dat);
//--用Socket API建立简易TCP服务端//1.建立一个socketSOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);//2 bind绑定用于接受客户端连接的网络端口sockaddr_in _sin = {};_sin.sin_family = AF_INET;_sin.sin_port = htons(4567);//host to net unsigned_sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");//使用127.0.0.1可以防止外网访问//启用本机全部的ip地址可以使用，INADDR_ANYif (SOCKET_ERROR == bind(_sock, (sockaddr*)&_sin, sizeof(sockaddr_in))){printf("错误，绑定网络端口失败...\n");}else{printf("绑定网络端口成功...\n");}//3 listen 监听网络端口if (SOCKET_ERROR == listen(_sock, 5)){printf("错误，监听网络端口失败...\n");}else{printf("监听网络端口成功...\n");}


while (true){fd_set fdRead;fd_set fdWrite;fd_set fdExp;
FD_ZERO(&fdRead);FD_ZERO(&fdWrite);FD_ZERO(&fdExp);
FD_SET(_sock, &fdRead);FD_SET(_sock, &fdWrite);FD_SET(_sock, &fdExp);//接入的客户端socket放入到 可读集合中，通过select来筛选出具有可读状态的socketfor (size_t n = 0; n<g_clients.size(); n++){FD_SET(g_clients[n], &fdRead);}
timeval t = {0,0};int ret = select(_sock + 1, &fdRead, &fdWrite, &fdExp, &t);if (ret < 0){printf("select任务结束。\n");break;}
if (FD_ISSET(_sock, &fdRead)){FD_CLR(_sock, &fdRead);//从集合移除了_socksockaddr_in clientAddr = {};int nAddrLen = sizeof(clientAddr);SOCKET _cSock = INVALID_SOCKET;
_cSock = accept(_sock, (sockaddr*)&clientAddr, &nAddrLen);if (INVALID_SOCKET == _cSock){printf("错误，接受到无效客户端socket...\n");}else{g_clients.push_back(_cSock);printf("新客户端加入:socket=%d,IP=%s\n", _cSock, inet_ntoa(clientAddr.sin_addr));}
}
for (size_t n = 0; n<fdRead.fd_count; n++){if (-1 == processor(fdRead.fd_array[n])){auto iter = find(g_clients.begin(), g_clients.end(), fdRead.fd_array[n]);if (iter != g_clients.end()){closesocket(*iter);g_clients.erase(iter);}}}

}
//6 关闭套接字closesocketfor (size_t n = 0; n<g_clients.size(); n++){closesocket(g_clients[n]);}closesocket(_sock);

//清除Windows socket环境WSACleanup();printf("已退出。\n");getchar();return 0;}