unix网络编程笔记---12.TCP的C/S之8serv用上poll

1. 流程描述
跟select很类似,注意这儿将client的第0项固定为listen的socket,
for循环要从1开始遍历

---

2. 代码

cong@msi:/work/test/tcpip/13poll/serv$ cat tcpserv.c
#include "utils.h"

int main ( int argc, char *argv[] )
{
    ssize_t n;
    int i, maxi;
    int listenfd, connfd, sockfd;
    int nready;
    struct pollfd client[OPEN_MAX];                 -->只需要分配一个pollfd即可
    struct sockaddr_in servaddr, cliaddr;
    char buf[MAXLINE];
    socklen_t clilen;
    listenfd = socket(AF_INET, SOCK_STREAM, 0);
    if(listenfd< 0)
        return -1;
    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_port = htons(13999);
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    //inet_pton(AF_INET, TIME_SERV_ADDR, &servaddr.sin_addr);

    bind(listenfd, (const struct sockaddr*)&servaddr, sizeof(servaddr));
    listen(listenfd, LISTENQ);
    //把第0项固定为listen的socket,其它的作为client的socket
    client[0].fd = listenfd;
    client[0].events = POLLRDNORM;
    maxi = 0;
    for(i=1; i<OPEN_MAX; i++)
        client[i].fd = -1;    -->其它的sockfd都设为-1
    while(1)
    {
        nready = poll(client, maxi+1, INFTIM);
        if(nready<0)
            continue;
        if(client[0].revents & POLLRDNORM)  -->当有变化时先检查固定的listen的socket是否有变化
        {                                   -->若有变化,说明client有连接
            clilen = sizeof(cliaddr);
            connfd = accept(listenfd, (struct sockaddr*)&cliaddr,&clilen);
            for(i=0; i<OPEN_MAX; i++)
            {
                if(client[i].fd < 0)
                {
                    client[i].fd = connfd;
                    break;
                }
            }
            if(i==OPEN_MAX)
                dbmsg("too many clients");
            client[i].events = POLLRDNORM;
            if(i>maxi)
                maxi = i;
            if(--nready <= 0)
                continue;
        }
        for(i=1; i<=maxi; i++)                  -->第0个socket固定为listen,所以从第1个socket开始遍历
        {                                       -->若有变化,说明client有数据
            if( (sockfd = client[i].fd) < 0)
                continue;
            //if(FD_ISSET(sockfd, &rset))
            if(client[i].revents & (POLLRDNORM|POLLERR))
            {
                if( (n=read(sockfd, buf, MAXLINE)) < 0)  -->当收到client的数据<0时
                {
                    if(errno == ECONNRESET)              -->如果是ECONNRESET,则说明client退出
                    {
                        close(sockfd);
                        client[i].fd = -1;
                    }
                }else {
                    write(sockfd, buf, n);
                }
                if(--nready <= 0)
                    break;
            }
        }
    }
    return EXIT_SUCCESS;
}

serv.rar (下载后改名为serv.tar.gz)
client.rar (下载后改名为client.tar.gz)