将服务端移植到Linux和MAC OS

1 将服务端移植到Linux和MAC OS

1.1 概述

这里我们将服务端移植到Linux和MAC OS，差异很小，直接上代码即可。

1.2 服务端代码实现

#ifdef _WIN32
	#define WIN32_LEAN_AND_MEAN
	#define _WINSOCK_DEPRECATED_NO_WARNINGS
	#include<windows.h>
	#include<WinSock2.h>
	#pragma comment(lib,"ws2_32.lib")
#else
	#include<unistd.h> //uni std
	#include<arpa/inet.h>
	#include<string.h>

	#define SOCKET int
	#define INVALID_SOCKET  (SOCKET)(~0)
	#define SOCKET_ERROR            (-1)
#endif

#include<stdio.h>
#include<thread>
#include<vector>



enum CMD
{
	CMD_LOGIN,
	CMD_LOGIN_RESULT,
	CMD_LOGOUT,
	CMD_LOGOUT_RESULT,
	CMD_NEW_USER_JOIN,
	CMD_ERROR
};

struct DataHeader
{
	short dataLength;
	short cmd;
};

//DataPackage
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_RESULT;
		result = 0;
	}
	int result;
};

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_RESULT;
		result = 0;
	}
	int result;
};

struct NewUserJoin : public DataHeader
{
	NewUserJoin()
	{
		dataLength = sizeof(NewUserJoin);
		cmd = CMD_NEW_USER_JOIN;
		scok = 0;
	}
	int scok;
};

std::vector<SOCKET> g_clients;

int processor(SOCKET _cSock)
{
	//缓冲区
	char szRecv[4096] = {};
	// 5 接收客户端数据
	int nLen = (int)recv(_cSock, szRecv, sizeof(DataHeader), 0);
	DataHeader* header = (DataHeader*)szRecv;
	if (nLen <= 0)
	{
		printf("客户端<Socket=%d>已退出，任务结束。\n", _cSock);
		return -1;
	}
	switch (header->cmd)
	{
	case CMD_LOGIN:
	{
		recv(_cSock, szRecv + sizeof(DataHeader), header->dataLength - sizeof(DataHeader), 0);
		Login* login = (Login*)szRecv;
		printf("收到客户端<Socket=%d>请求：CMD_LOGIN,数据长度：%d,userName=%s PassWord=%s\n", _cSock, login->dataLength, login->userName, login->PassWord);
		//忽略判断用户密码是否正确的过程
		LoginResult ret;
		send(_cSock, (char*)&ret, sizeof(LoginResult), 0);
	}
	break;
	case CMD_LOGOUT:
	{
		recv(_cSock, szRecv + sizeof(DataHeader), header->dataLength - sizeof(DataHeader), 0);
		Logout* logout = (Logout*)szRecv;
		printf("收到客户端<Socket=%d>请求：CMD_LOGOUT,数据长度：%d,userName=%s \n", _cSock, logout->dataLength, logout->userName);
		//忽略判断用户密码是否正确的过程
		LogoutResult ret;
		send(_cSock, (char*)&ret, sizeof(ret), 0);
	}
	break;
	default:
	{
		DataHeader header = { 0,CMD_ERROR };
		send(_cSock, (char*)&header, sizeof(header), 0);
	}
	break;
	}
	return 0;
}

int main()
{
#ifdef _WIN32
	//启动Windows socket 2.x环境
	WORD ver = MAKEWORD(2, 2);
	WSADATA dat;
	WSAStartup(ver, &dat);
	//------------
#endif
	//-- 用Socket API建立简易TCP服务端
	// 1 建立一个socket 套接字
	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 short
#ifdef _WIN32
	_sin.sin_addr.S_un.S_addr = INADDR_ANY;//inet_addr("127.0.0.1");
#else
	_sin.sin_addr.s_addr = INADDR_ANY;
#endif
	if (SOCKET_ERROR == bind(_sock, (sockaddr*)&_sin, sizeof(_sin)))
	{
		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)
	{
		//伯克利套接字 BSD socket
		fd_set fdRead;//描述符（socket） 集合
		fd_set fdWrite;
		fd_set fdExp;
		//清理集合
		FD_ZERO(&fdRead);
		FD_ZERO(&fdWrite);
		FD_ZERO(&fdExp);
		//将描述符（socket）加入集合
		FD_SET(_sock, &fdRead);
		FD_SET(_sock, &fdWrite);
		FD_SET(_sock, &fdExp);
		SOCKET maxSock = _sock;
		for (int n = (int)g_clients.size() - 1; n >= 0; n--)
		{
			FD_SET(g_clients[n], &fdRead);
			if (maxSock < g_clients[n])
			{
				maxSock = g_clients[n];
			}
		}
		///nfds 是一个整数值 是指fd_set集合中所有描述符(socket)的范围，而不是数量
		///既是所有文件描述符最大值+1 在Windows中这个参数可以写0
		timeval t = { 1,0 };
		int ret = select(maxSock + 1, &fdRead, &fdWrite, &fdExp, &t);
		if (ret < 0)
		{
			printf("select任务结束。\n");
			break;
		}
		//判断描述符（socket）是否在集合中
		if (FD_ISSET(_sock, &fdRead))
		{
			FD_CLR(_sock, &fdRead);
			// 4 accept 等待接受客户端连接
			sockaddr_in clientAddr = {};
			int nAddrLen = sizeof(sockaddr_in);
			SOCKET _cSock = INVALID_SOCKET;
#ifdef _WIN32
			_cSock = accept(_sock, (sockaddr*)&clientAddr, &nAddrLen);
#else
			_cSock = accept(_sock, (sockaddr*)&clientAddr, (socklen_t *)&nAddrLen);
#endif
			if (INVALID_SOCKET == _cSock)
			{
				printf("错误,接受到无效客户端SOCKET...\n");
			}
			else
			{
				for (int n = (int)g_clients.size() - 1; n >= 0; n--)
				{
					NewUserJoin userJoin;
					send(g_clients[n], (const char*)&userJoin, sizeof(NewUserJoin), 0);
				}
				g_clients.push_back(_cSock);
				printf("新客户端加入：socket = %d,IP = %s \n", (int)_cSock, inet_ntoa(clientAddr.sin_addr));
			}
		}
		for (int n = (int)g_clients.size() - 1; n >= 0; n--)
		{
			if (FD_ISSET(g_clients[n], &fdRead))
			{
				if (-1 == processor(g_clients[n]))
				{
					auto iter = g_clients.begin() + n;//std::vector<SOCKET>::iterator
					if (iter != g_clients.end())
					{
						g_clients.erase(iter);
					}
				}
			}
		}
		//printf("空闲时间处理其它业务..\n");
	}
#ifdef _WIN32
	for (int n = (int)g_clients.size() - 1; n >= 0; n--)
	{
		closesocket(g_clients[n]);
	}
	// 8 关闭套节字closesocket
	closesocket(_sock);
	//------------
	//清除Windows socket环境
	WSACleanup();
#else
	for (int n = (int)g_clients.size() - 1; n >= 0; n--)
	{
		close(g_clients[n]);
	}
	// 8 关闭套节字closesocket
	close(_sock);
#endif
	printf("已退出。\n");
	getchar();
	return 0;
}

---

参考资料：

1. C++ 百万并发网络通信引擎架构与实现 （服务端、客户端、跨平台） Version 1.0