多线程服务器

步骤

主线程创建子线程，用子线程和客户端通信。
步骤：
1.使用socket函数，获取一个socket文件描述符
2.使用setsockopt端口复用
3.使用bind函数允许客户端的哪些ip可以访问服务器
4.使用listen监听客户端连接
5.使用accept从已连接的客户端队列中取出一个文件描述符，与它通信
6.使用pthread_create函数创建一个子线程去与上面的文件描述符通信
7.使用pthread_detach函数将子线程设置为分离属性，让它自动回收资源

代码

#include <socketwrap.h>
#include <arpa/inet.h>
#include <pthread.h>
#include <strings.h>
#include <string.h>
#include <ctype.h>
#include <arpa/inet.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <unistd.h>

typedef struct info
{
   
    int cfd; // 若为-1表示可用, 大于0表示已被占用
    int idx;
    pthread_t thread;          // 由pthread_create 返回
    struct sockaddr_in client; // 由accept 返回
} INFO;

INFO thInfo[1024];

void initThreadArr()
{
   
    for (int i = 0; i < 1024; i++)
    {
   
        bzero(&thInfo[i],sizeof(thInfo[i]));
        thInfo[i].cfd = -1;
    }
}

int findIndex()
{
   
    int i;
    for (i = 0; i < 1024; i++)
    {
   
        if (thInfo[i].cfd == -1)
        {
   
            return i;
        }
    }
    if (i == 1024)
    {
   
        return -1;
    }
}

void *threadFunc(void *arg)
{
   
    INFO *curthread = (INFO *)arg;
    char sIP[16];
    printf("current thread id [%ld],arr index is [%d],cfd is [%d],client ip is [%s:%d]\n", pthread_self(), curthread->idx, curthread->cfd, inet_ntop(AF_INET, &curthread->client.sin_addr.s_addr, sIP, sizeof(sIP)), ntohs(curthread->client.sin_port));
    char buff[64];
    while (1)
    {
   
        memset(buff, 0x00, sizeof(buff));
        int n = Read(curthread->cfd, buff, sizeof(buff));
        if (n == 0)
        {
   
            bzero(&thInfo[curthread->idx],sizeof(thInfo[curthread->idx]));
            thInfo[thInfo->idx].cfd = -1;
            return 0;
        }
        else if (n < 0)
        {
   
            bzero(&thInfo[curthread->idx],sizeof(thInfo[curthread->idx]));
            thInfo[thInfo->idx].cfd = -1;
            perror("child read error");
            return 0;
        }

        printf("child thread [%ld] recv data from [%s:%d]:[%s]\n", pthread_self(), inet_ntop(AF_INET, &curthread->client.sin_addr.s_addr, sIP, sizeof(sIP)), ntohs(curthread->client.sin_port), buff);
        for (int i = 0; i < n; i++)
        {
   
            buff[i] = toupper(buff[i]);
        }
        n = Write(curthread->cfd, buff, n);
        if (n <= 0)
        {
   
            bzero(&thInfo[curthread->idx],sizeof(thInfo[curthread->idx]));
            thInfo[thInfo->idx].cfd = -1;
            perror("child write error");
            return 0;
        }
    }
}

int main()
{
   

    initThreadArr();

    int sfd = Socket(AF_INET, SOCK_STREAM, 0);

    // 设置端口复用
    int opt = 1;
    setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(int));

    struct sockaddr_in soaddr;
    bzero(&soaddr, sizeof(soaddr));

    soaddr.sin_family = AF_INET;
    soaddr.sin_port = htons(9999);
    soaddr.sin_addr.s_addr = htonl(INADDR_ANY);

    Bind(sfd, (struct sockaddr *)&soaddr, sizeof(soaddr));

    // 监听-listen
    Listen(sfd, 128);

    struct sockaddr_in clientsocket;
    socklen_t clilen;

    int cfd;
    int index;
    int ret;

    while (1)
    {
   
        index = -1;
        clilen = sizeof(clientsocket);
        bzero(&clientsocket, clilen);

        cfd = Accept(sfd, (struct sockaddr *)&clientsocket, &clilen);
        // 从线程数组中找一个可以用的
        index = findIndex();
        thInfo[index].idx = index;
        thInfo[index].client = clientsocket;
        thInfo[index].cfd = cfd;

        // 创建线程
        ret = pthread_create(&thInfo[index].thread, NULL, threadFunc, &thInfo[index]);

        if (ret != 0)
        {
   
            printf("create thread error:[%s]\n", strerror(ret));
            exit(-1);
        }

        // 设置子线程为分离属性
        pthread_detach(thInfo[index].thread);
    }

    Close(sfd);

    return 0;
}