十二、突破Windows下select64限制
作者：互联网
突破Windows下select64限制
前言
之前的文章，我们解决了在跨平台下收发1000k消息的粘包、少包问题
在测试的过程我们也发现了
windows下select的限制是64
Liunx下select的默认是1024
接下来我们来研究如何突破windows下select64的限制
一、跨平台select限制查看
1、windows下select限制
通过WinSock2.h查看到windows下FD_SETSIZE是64
/*
* Select uses arrays of SOCKETs. These macros manipulate such
* arrays. FD_SETSIZE may be defined by the user before including
* this file, but the default here should be >= 64.
*
* CAVEAT IMPLEMENTOR and USER: THESE MACROS AND TYPES MUST BE
* INCLUDED IN WINSOCK2.H EXACTLY AS SHOWN HERE.
*/
#ifndef FD_SETSIZE
#define FD_SETSIZE 64
#endif /* FD_SETSIZE */
2、Linux下select限制
因为MacOS和Linux一样都是使用的Unix系统
Linux下的select限制通过在MacOS系统中来查看源码
通过源码查看到Linux下的FD_SETSIZE是1024
#ifdef FD_SETSIZE
#define __DARWIN_FD_SETSIZE FD_SETSIZE
#else /* !FD_SETSIZE */
#define __DARWIN_FD_SETSIZE 1024
#endif /* FD_SETSIZE */
#define __DARWIN_NBBY 8 /* bits in a byte */
#define __DARWIN_NFDBITS (sizeof(__int32_t) * __DARWIN_NBBY) /* bits per mask */
#define __DARWIN_howmany(x, y) ((((x) % (y)) == 0) ? ((x) / (y)) : (((x) / (y)) + 1)) /* # y's == x bits? */
__BEGIN_DECLS
typedef struct fd_set {
__int32_t fds_bits[__DARWIN_howmany(__DARWIN_FD_SETSIZE, __DARWIN_NFDBITS)];
} fd_set;
__END_DECLS
二、超过1024连接的解决方案
Windows下使用IOCP网络模型
Linux下使用epoll网络模型
三、Windows下突破select64限制
在自己的头文件中重新定义这个宏（注意：必须在WindSock2.h头文件之前定义，因为其有ifndef的条件）
#ifdef _WIN32
#define FD_SETSIZE 1024
#define _CRT_SECURE_NO_WARNINGS
#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
四、测试
1、Windows下测试
server本机，client本机，client连接1000\
- 测试结论：
1、1000个client的连接效率还是比较慢的
2、收发消息带宽稳定在1Gbps
3、TCP延迟在4ms左右，丢包率0%
五、完整源码
1、MessageHeader.hpp
#ifndef _MessageHeader_hpp_
#define _MessageHeader_hpp_
enum CMD
{
CMD_LOGIN,
CMD_LOGIN_RESULT,
CMD_LOGOUT,
CMD_LOGOUT_RESULT,
CMD_NEW_USER_JOIN,
CMD_ERROR
};
struct DataHeader
{
DataHeader()
{
dataLength = sizeof(DataHeader);
cmd = CMD_ERROR;
}
short dataLength;
short cmd;
};
//DataPackage
struct Login : public DataHeader
{
Login()
{
dataLength = sizeof(Login);
cmd = CMD_LOGIN;
}
char userName[32];
char PassWord[32];
char data[932];
};
struct LoginResult : public DataHeader
{
LoginResult()
{
dataLength = sizeof(LoginResult);
cmd = CMD_LOGIN_RESULT;
result = 0;
}
int result;
char data[992];
};
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;
};
#endif // !_MessageHeader_hpp_
2、服务端源码
a）EasyTcpServer.hpp
#ifndef _EasyTcpServer_hpp_
#define _EasyTcpServer_hpp_
#ifdef _WIN32
#define FD_SETSIZE 1024
#define _CRT_SECURE_NO_WARNINGS
#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<vector>
#include"MessageHeader.hpp"
//缓冲区最小单元大小
#ifndef RECV_BUFF_SZIE
#define RECV_BUFF_SZIE 10240
#endif // !RECV_BUFF_SZIE
class ClientSocket
{
public:
ClientSocket(SOCKET sockfd = INVALID_SOCKET)
{
_sockfd = sockfd;
memset(_szMsgBuf, 0, sizeof(_szMsgBuf));
_lastPos = 0;
}
SOCKET sockfd()
{
return _sockfd;
}
char* msgBuf()
{
return _szMsgBuf;
}
int getLastPos()
{
return _lastPos;
}
void setLastPos(int pos)
{
_lastPos = pos;
}
private:
// socket fd_set file desc set
SOCKET _sockfd;
//第二缓冲区 消息缓冲区
char _szMsgBuf[RECV_BUFF_SZIE * 10];
//消息缓冲区的数据尾部位置
int _lastPos;
};
class EasyTcpServer
{
private:
SOCKET _sock;
std::vector<ClientSocket*> _clients;
public:
EasyTcpServer()
{
_sock = INVALID_SOCKET;
}
virtual ~EasyTcpServer()
{
Close();
}
//初始化Socket
SOCKET InitSocket()
{
#ifdef _WIN32
//启动Windows socket 2.x环境
WORD ver = MAKEWORD(2, 2);
WSADATA dat;
WSAStartup(ver, &dat);
#endif
if (INVALID_SOCKET != _sock)
{
printf("<socket=%d>关闭旧连接...\n", (int)_sock);
Close();
}
_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (INVALID_SOCKET == _sock)
{
printf("错误，建立socket失败...\n");
}
else {
printf("建立socket=<%d>成功...\n", (int)_sock);
}
return _sock;
}
//绑定IP和端口号
int Bind(const char* ip, unsigned short port)
{
//if (INVALID_SOCKET == _sock)
//{
// InitSocket();
//}
// 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(port);//host to net unsigned short
#ifdef _WIN32
if (ip) {
_sin.sin_addr.S_un.S_addr = inet_addr(ip);
}
else {
_sin.sin_addr.S_un.S_addr = INADDR_ANY;
}
#else
if (ip) {
_sin.sin_addr.s_addr = inet_addr(ip);
}
else {
_sin.sin_addr.s_addr = INADDR_ANY;
}
#endif
int ret = bind(_sock, (sockaddr*)&_sin, sizeof(_sin));
if (SOCKET_ERROR == ret)
{
printf("错误,绑定网络端口<%d>失败...\n", port);
}
else {
printf("绑定网络端口<%d>成功...\n", port);
}
return ret;
}
//监听端口号
int Listen(int n)
{
// 3 listen 监听网络端口
int ret = listen(_sock, n);
if (SOCKET_ERROR == ret)
{
printf("socket=<%d>错误,监听网络端口失败...\n", _sock);
}
else {
printf("socket=<%d>监听网络端口成功...\n", _sock);
}
return ret;
}
//接受客户端连接
SOCKET Accept()
{
// 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("socket=<%d>错误,接受到无效客户端SOCKET...\n", (int)_sock);
}
else
{
NewUserJoin userJoin;
SendDataToAll(&userJoin);
_clients.push_back(new ClientSocket(cSock));
printf("socket=<%d>新客户端加入：socket = %d,IP = %s \n", (int)_sock, (int)cSock, inet_ntoa(clientAddr.sin_addr));
}
return cSock;
}
//关闭Socket
void Close()
{
if (_sock != INVALID_SOCKET)
{
#ifdef _WIN32
for (int n = (int)_clients.size() - 1; n >= 0; n--)
{
closesocket(_clients[n]->sockfd());
delete _clients[n];
}
// 8 关闭套节字closesocket
closesocket(_sock);
//------------
//清除Windows socket环境
WSACleanup();
#else
for (int n = (int)_clients.size() - 1; n >= 0; n--)
{
close(_clients[n]->sockfd());
delete _clients[n];
}
// 8 关闭套节字closesocket
close(_sock);
#endif
_clients.clear();
}
}
//处理网络消息
int _nCount = 0;
bool OnRun()
{
if (isRun())
{
//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)_clients.size() - 1; n >= 0; n--)
{
FD_SET(_clients[n]->sockfd(), &fdRead);
if (maxSock < _clients[n]->sockfd())
{
maxSock = _clients[n]->sockfd();
}
}
///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); //
//printf("select ret=%d count=%d\n", ret, _nCount++);
if (ret < 0)
{
printf("select任务结束。\n");
Close();
return false;
}
//判断描述符（socket）是否在集合中
if (FD_ISSET(_sock, &fdRead))
{
FD_CLR(_sock, &fdRead);
Accept();
}
for (int n = (int)_clients.size() - 1; n >= 0; n--)
{
if (FD_ISSET(_clients[n]->sockfd(), &fdRead))
{
if (-1 == RecvData(_clients[n]))
{
auto iter = _clients.begin() + n;//std::vector<SOCKET>::iterator
if (iter != _clients.end())
{
delete _clients[n];
_clients.erase(iter);
}
}
}
}
return true;
}
return false;
}
//是否工作中
bool isRun()
{
return _sock != INVALID_SOCKET;
}
//缓冲区
char _szRecv[RECV_BUFF_SZIE] = {};
//接收数据 处理粘包 拆分包
int RecvData(ClientSocket* pClient)
{
// 5 接收客户端数据
int nLen = (int)recv(pClient->sockfd(), _szRecv, RECV_BUFF_SZIE, 0);
//printf("nLen=%d\n", nLen);
if (nLen <= 0)
{
printf("客户端<Socket=%d>已退出，任务结束。\n", pClient->sockfd());
return -1;
}
//将收取到的数据拷贝到消息缓冲区
memcpy(pClient->msgBuf() + pClient->getLastPos(), _szRecv, nLen);
//消息缓冲区的数据尾部位置后移
pClient->setLastPos(pClient->getLastPos() + nLen);
//判断消息缓冲区的数据长度大于消息头DataHeader长度
while (pClient->getLastPos() >= sizeof(DataHeader))
{
//这时就可以知道当前消息的长度
DataHeader* header = (DataHeader*)pClient->msgBuf();
//判断消息缓冲区的数据长度大于消息长度
if (pClient->getLastPos() >= header->dataLength)
{
//消息缓冲区剩余未处理数据的长度
int nSize = pClient->getLastPos() - header->dataLength;
//处理网络消息
OnNetMsg(pClient->sockfd(), header);
//将消息缓冲区剩余未处理数据前移
memcpy(pClient->msgBuf(), pClient->msgBuf() + header->dataLength, nSize);
//消息缓冲区的数据尾部位置前移
pClient->setLastPos(nSize);
}
else {
//消息缓冲区剩余数据不够一条完整消息
break;
}
}
return 0;
}
//响应网络消息
virtual void OnNetMsg(SOCKET cSock, DataHeader* header)
{
switch (header->cmd)
{
case CMD_LOGIN:
{
Login* login = (Login*)header;
//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;
SendData(cSock, &ret);
}
break;
case CMD_LOGOUT:
{
Logout* logout = (Logout*)header;
//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;
SendData(cSock, &ret);
}
break;
default:
{
printf("<socket=%d>收到未定义消息,数据长度：%d\n", cSock, header->dataLength);
//DataHeader ret;
//SendData(cSock, &ret);
}
break;
}
}
//发送指定Socket数据
int SendData(SOCKET cSock, DataHeader* header)
{
if (isRun() && header)
{
return send(cSock, (const char*)header, header->dataLength, 0);
}
return SOCKET_ERROR;
}
void SendDataToAll(DataHeader* header)
{
for (int n = (int)_clients.size() - 1; n >= 0; n--)
{
SendData(_clients[n]->sockfd(), header);
}
}
};
#endif // !_EasyTcpServer_hpp_
b）server.cpp
#include "EasyTcpServer.hpp"
#include<thread>
bool g_bRun = true;
void cmdThread()
{
while (true)
{
char cmdBuf[256] = {};
scanf("%s", cmdBuf);
if (0 == strcmp(cmdBuf, "exit"))
{
g_bRun = false;
printf("退出cmdThread线程\n");
break;
}
else {
printf("不支持的命令。\n");
}
}
}
int main()
{
EasyTcpServer server;
server.InitSocket();
server.Bind(nullptr, 4567);
server.Listen(5);
//启动UI线程
std::thread t1(cmdThread);
t1.detach();
while (g_bRun)
{
server.OnRun();
//printf("空闲时间处理其它业务..\n");
}
server.Close();
printf("已退出。\n");
getchar();
return 0;
}
3、客户端源码
a）EasyTcpClient.hpp
#ifndef _EasyTcpClient_hpp_
#define _EasyTcpClient_hpp_
#ifdef _WIN32
#define _CRT_SECURE_NO_WARNINGS
#define _WINSOCK_DEPRECATED_NO_WARNINGS
#define WIN32_LEAN_AND_MEAN
#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 "MessageHeader.hpp"
class EasyTcpClient
{
SOCKET _sock;
public:
EasyTcpClient()
{
_sock = INVALID_SOCKET;
}
virtual ~EasyTcpClient()
{
Close();
}
//初始化socket
void InitSocket()
{
#ifdef _WIN32
//启动Windows socket 2.x环境
WORD ver = MAKEWORD(2, 2);
WSADATA dat;
WSAStartup(ver, &dat);
#endif
if (INVALID_SOCKET != _sock)
{
printf("<socket=%d>关闭旧连接...\n", _sock);
Close();
}
_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (INVALID_SOCKET == _sock)
{
printf("错误，建立Socket失败...\n");
}
else {
printf("建立Socket=<%d>成功...\n", _sock);
}
}
//连接服务器
int Connect(const char* ip, unsigned short port)
{
if (INVALID_SOCKET == _sock)
{
InitSocket();
}
// 2 连接服务器 connect
sockaddr_in _sin = {};
_sin.sin_family = AF_INET;
_sin.sin_port = htons(port);
#ifdef _WIN32
_sin.sin_addr.S_un.S_addr = inet_addr(ip);
#else
_sin.sin_addr.s_addr = inet_addr(ip);
#endif
printf("<socket=%d>正在连接服务器<%s:%d>...\n", _sock, ip, port);
int ret = connect(_sock, (sockaddr*)&_sin, sizeof(sockaddr_in));
if (SOCKET_ERROR == ret)
{
printf("<socket=%d>错误，连接服务器<%s:%d>失败...\n", _sock, ip, port);
}
else {
printf("<socket=%d>连接服务器<%s:%d>成功...\n", _sock, ip, port);
}
return ret;
}
//关闭套节字closesocket
void Close()
{
if (_sock != INVALID_SOCKET)
{
#ifdef _WIN32
closesocket(_sock);
//清除Windows socket环境
WSACleanup();
#else
close(_sock);
#endif
_sock = INVALID_SOCKET;
}
}
//处理网络消息
int _nCount = 0;
bool OnRun()
{
if (isRun())
{
fd_set fdReads;
FD_ZERO(&fdReads);
FD_SET(_sock, &fdReads);
timeval t = { 0,0 };
int ret = select(_sock + 1, &fdReads, 0, 0, &t);
//printf("select ret=%d count=%d\n", ret, _nCount++);
if (ret < 0)
{
printf("<socket=%d>select任务结束1\n", _sock);
Close();
return false;
}
if (FD_ISSET(_sock, &fdReads))
{
FD_CLR(_sock, &fdReads);
if (-1 == RecvData(_sock))
{
printf("<socket=%d>select任务结束2\n", _sock);
Close();
return false;
}
}
return true;
}
return false;
}
//是否工作中
bool isRun()
{
return _sock != INVALID_SOCKET;
}
//缓冲区最小单元大小
#ifndef RECV_BUFF_SZIE
#define RECV_BUFF_SZIE 10240
#endif // !RECV_BUFF_SZIE
//第二缓冲区 消息缓冲区
char _szMsgBuf[RECV_BUFF_SZIE * 10] = {};
//消息缓冲区的数据尾部位置
int _lastPos = 0;
//接收缓冲区
char _szRecv[RECV_BUFF_SZIE] = {};
//接收数据 处理粘包 拆分包
int RecvData(SOCKET cSock)
{
// 5 接收数据
int nLen = (int)recv(cSock, _szRecv, RECV_BUFF_SZIE, 0);
//printf("nLen=%d\n", nLen);
if (nLen <= 0)
{
printf("<socket=%d>与服务器断开连接，任务结束。\n", cSock);
return -1;
}
//将收取到的数据拷贝到消息缓冲区
memcpy(_szMsgBuf + _lastPos, _szRecv, nLen);
//消息缓冲区的数据尾部位置后移
_lastPos += nLen;
//判断消息缓冲区的数据长度大于消息头DataHeader长度
while (_lastPos >= sizeof(DataHeader))
{
//这时就可以知道当前消息的长度
DataHeader* header = (DataHeader*)_szMsgBuf;
//判断消息缓冲区的数据长度大于消息长度
if (_lastPos >= header->dataLength)
{
//消息缓冲区剩余未处理数据的长度
int nSize = _lastPos - header->dataLength;
//处理网络消息
OnNetMsg(header);
//将消息缓冲区剩余未处理数据前移
memcpy(_szMsgBuf, _szMsgBuf + header->dataLength, nSize);
//消息缓冲区的数据尾部位置前移
_lastPos = nSize;
}
else {
//消息缓冲区剩余数据不够一条完整消息
break;
}
}
return 0;
}
//响应网络消息
virtual void OnNetMsg(DataHeader* header)
{
switch (header->cmd)
{
case CMD_LOGIN_RESULT:
{
LoginResult* login = (LoginResult*)header;
//printf("<socket=%d>收到服务端消息：CMD_LOGIN_RESULT,数据长度：%d\n", _sock, login->dataLength);
}
break;
case CMD_LOGOUT_RESULT:
{
LogoutResult* logout = (LogoutResult*)header;
//printf("<socket=%d>收到服务端消息：CMD_LOGOUT_RESULT,数据长度：%d\n", _sock, logout->dataLength);
}
break;
case CMD_NEW_USER_JOIN:
{
NewUserJoin* userJoin = (NewUserJoin*)header;
//printf("<socket=%d>收到服务端消息：CMD_NEW_USER_JOIN,数据长度：%d\n", _sock, userJoin->dataLength);
}
break;
case CMD_ERROR:
{
printf("<socket=%d>收到服务端消息：CMD_ERROR,数据长度：%d\n", _sock, header->dataLength);
}
break;
default:
{
printf("<socket=%d>收到未定义消息,数据长度：%d\n", _sock, header->dataLength);
}
}
}
//发送数据
int SendData(DataHeader* header)
{
if (isRun() && header)
{
return send(_sock, (const char*)header, header->dataLength, 0);
}
return SOCKET_ERROR;
}
private:
};
#endif
b）client.cpp
#include "EasyTcpClient.hpp"
#include<thread>
bool g_bRun = true;
void cmdThread()
{
while (true)
{
char cmdBuf[256] = {};
scanf("%s", cmdBuf);
if (0 == strcmp(cmdBuf, "exit"))
{
g_bRun = false;
printf("退出cmdThread线程\n");
break;
}
else {
printf("不支持的命令。\n");
}
}
}
int main()
{
//const int cCount = FD_SETSIZE - 1;
const int cCount = 1000;
EasyTcpClient* client[cCount];
for (int n = 0; n < cCount; n++)
{
client[n] = new EasyTcpClient();
}
for (int n = 0; n < cCount; n++)
{
client[n]->Connect("127.0.0.1", 4567);
//client[n]->Connect("192.168.58.129", 4567);
}
//启动UI线程
std::thread t1(cmdThread);
t1.detach();
Login login;
strcpy(login.userName, "lyd");
strcpy(login.PassWord, "lydmm");
while (g_bRun)
{
for (int n = 0; n < cCount; n++)
{
client[n]->SendData(&login);
client[n]->OnRun();
}
//printf("空闲时间处理其它业务..\n");
//Sleep(1000);
}
for (int n = 0; n < cCount; n++)
{
client[n]->Close();
}
printf("已退出。\n");
getchar();
return 0;
}
标签：SOCKET,select64,header,Windows,sock,十二,int,printf,define 来源： https://blog.csdn.net/qq23001186/article/details/122706101