Linux下TCP并发服务器：Select + 多线程模式

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/wangqingchuan92/article/details/80690799

1.前言

1.1声明

文章中的文字可能存在语法错语以及标点错误，请谅解；

如果在文章中发现代码错误或其它问题请告知，感谢！

2.代码实现

man.c代码如下：

#include<stdio.h>
#include <string.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stdlib.h>
#include <pthread.h>
#include <signal.h>

#include "sharefun.h"

#define PORT 5000
#define MAX_SIZE FD_SETSIZE //最大可用已连接套接字的个数
#define LISTEN_MAX 5
#define BUF_SIZE 10240

fd_set fds;

static void PrintMesg(int i , char buf[])
{
    printf("fd : %d, msg: %s\n", i , buf);
}

void *TCP_Analyzer(void *pPara)
{
    char Buf[BUF_SIZE] = {0};
    ssize_t Size  = 0;
    int *pConnfd = 0;
    unsigned char *pReceiveData = NULL;
    int ReceiveLen = 0;

    if (NULL == pPara)
    {
        VOS_PRINTF_LOG("TCP_Analyzer: TCP_Analyzer Failed!\n");
        return NULL;
    }

    pConnfd = (int *)pPara;
    if(*pConnfd < 0)
    {
        VOS_PRINTF_LOG("TCP_Analyzer:Get pConnfd Failed \n" );
        return NULL;
    }

    while(1)
    {
        memset(Buf, '\0', sizeof(Buf));
        Size = read(*pConnfd, Buf,sizeof(Buf) );
        if (Size <= 0) //没有接收到数据，关闭描述符，释放在TCPServer申请的空间
        {
            VOS_PRINTF_LOG("TCP_Analyzer:remote client close\n" );
            close(*pConnfd);
            VOS_FREE(pConnfd);
            return NULL;
        }
        else
        {
            printf("TCP_Analyzer:%s,%d\n",Buf,(int)Size);
        }
    }
    close(*pConnfd);
    VOS_FREE(pConnfd);

    return NULL;
}

void *TCPServer()
{
    pthread_t threadID = 0;
    struct sockaddr_in Server;
    struct sockaddr_in Client;
    int Listenfd = 0;
    int *pConnectfd = NULL;
    int i = 0;
    int j = 0;
    int yes = 0;
    int index = 0;
    int Connfd = 0;
    int ret = 0;
    socklen_t len = 0;
    char logMessage[128] = {0};
    pthread_attr_t attr;
    pthread_attr_init(&attr);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

    Listenfd = socket(AF_INET, SOCK_STREAM, 0);
    if (Listenfd < 0)
    {
        perror("socket");
        exit(1);
    }
    VOS_PRINTF_LOG("TCPServer:create socket success\n");

    setsockopt(Listenfd, SOL_SOCKET, SO_REUSEADDR, &yes ,sizeof(int));// 允许IP地址复用

    bzero(&Server, sizeof(Server));
    Server.sin_family = AF_INET;
    Server.sin_port = htons(PORT );
    Server.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(Listenfd, (struct sockaddr*)&Server, sizeof(Server)) < 0)
    {
        perror("bind");
        exit(2);
    }
    VOS_PRINTF_LOG("TCPServer:bind socket success\n");

    if (listen(Listenfd, LISTEN_MAX) < 0)
    {
        perror("listen error");
        exit(3);
    }
    VOS_PRINTF_LOG("TCPServer:listen socket success\n");

    while (1)
    {
        FD_ZERO(&fds);//描述符集合初始化
        FD_SET(Listenfd,&fds);

        struct timeval timeout = {30, 0};

        switch(select(Listenfd + 1, &fds,NULL, NULL, &timeout ))
        {
            case -1:
                memset(logMessage, 0, 128);
                sprintf(logMessage,"main: create TCP server select fail(%d) %s.\n", errno, strerror(errno));
                VOS_PRINTF_LOG(logMessage);
                return NULL;

            case 0:
                VOS_PRINTF_LOG("TCPServer:TCP receiving nothing......\n");
                break;

            default:
            {
                if (FD_ISSET(Listenfd, &fds))
                {
                    len = sizeof(Client);
                    bzero(&Client, len);

                    Connfd = accept(Listenfd, (struct sockaddr*)&Client,&len );
                    //若有新的连接
                    if (Connfd != -1)
                    {
                        pConnectfd = (int *)malloc(sizeof(int));
                        if (NULL == pConnectfd)
                        {
                            VOS_PRINTF_LOG("TCPServer: pConnectfd malloc Failed.\n");
                            break;
                        }

                        memset(pConnectfd,0,sizeof(int));
                        *pConnectfd = Connfd;

                        VOS_PRINTF_LOG("TCPServer:get a new request!\n");
                        printf("TCPServer:the connect fd is %d\n",Connfd);

                        ret = pthread_create(&threadID, &attr, TCP_Analyzer, (void *)pConnectfd);
                        if(0 != ret)
                        {
                            VOS_PRINTF_LOG("TCPServer: TCP_Analyzer build Fail!\n");
                            FD_CLR(Listenfd, &fds);// 清除 fds中相应的文件描述符
                            VOS_FREE(pConnectfd);
                            return NULL;
                        }

                    }
                }
            }
        }
    }
    close(Listenfd);
    FD_CLR(Listenfd, &fds);// 清除 fds中相应的文件描述符
    pthread_attr_destroy(&attr);//线程属性销毁
    VOS_FREE(pConnectfd);
    return NULL;
}

int main()
{
    int ret = 0;
    pthread_t threadID = 0;

    VOS_PRINTF_ENABLE();

    VOS_PRINTF_LOG("Main Init OK!\n");

    ret = pthread_create(&threadID, NULL, TCPServer, NULL);
    if(0 != ret)
    {
        (void)VOS_PRINTF_LOG("TCPServer: TCPServer build Fail!\n");
        return VOS_ERR;
    }

    while(1)
    {
        sleep(10);
    }

    return 0;
}

编译指令：gcc -o test *.c -lpthread

运行指令：./test

在这里使用网络助手软件作为客户端，在软件中设置好服务器IP以及端口号以后，连接，发送报文验证服务器：

服务器端接收：

整个项目代码的GitHub下载地址：
https://github.com/fyw4/TCPServer
Linux下的网络调试助手下载地址：
https://download.csdn.net/download/wangqingchuan92/10478402
参考资料：
https://wenku.baidu.com/view/a356287af61fb7360a4c6525.html
https://blog.csdn.net/ciaos/article/details/7710674