epoll多路复用_并发服务器

应用程序：

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

#define ERR_MSG(msg)                   \
    do                                 \
    {                                  \
        printf("line:%d\n", __LINE__); \
        perror(msg);                   \
    } while (0)

#define PORT 6666            //端口号
#define IP "192.168.250.100" // IP地址

int main(int argc, const char *argv[])
{
    //创建流式套接字
    int sfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sfd < 0)
    {
        ERR_MSG("socket");
        return -1;
    }
    printf("socket create success sfd=%d __%d__\n", sfd, __LINE__);

    //设置端口快速被复用
    int reuse = 1;
    if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)) < 0)
    {
        ERR_MSG("setsockopt");
        return -1;
    }

    //填充服务器自身的地址信息结构体
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(PORT);
    sin.sin_addr.s_addr = inet_addr(IP);

    //存储客户端信息结构体
    int s_res = 0;
    struct sockaddr_in cin;
    socklen_t len = sizeof(cin);
    struct sockaddr_in savecin[1024];

    //将IP地址和端口号绑定到指定的套接字文件描述符上
    if (bind(sfd, (struct sockaddr *)&sin, sizeof(sin)) < 0)
    {
        ERR_MSG("bind");
        return -1;
    }
    printf("bind success __%d__\n", __LINE__);

    //将套接字设置为被动监听状态
    if (listen(sfd, 128) < 0)
    {
        ERR_MSG("listen");
        return -1;
    }
    printf("listen success __%d__\n", __LINE__);

    char buf[128] = "";
    ssize_t res = 0;
    // epoll
    int fd, newfd, epfd;

    struct epoll_event event;
    struct epoll_event events[10]; //存放就绪事件描述符的数组

    //创建epoll句柄
    epfd = epoll_create(1);
    if (epfd < 0)
    {
        printf("epoll_create filed\n");
        exit(-1);
    }

    event.events = EPOLLIN;
    event.data.fd = sfd;
    if (epoll_ctl(epfd, EPOLL_CTL_ADD, sfd, &event) < 0)
    {
        printf("epoll_ctl add filed\n");
    }

    //监听事件是否发生
    while (1)
    {
        //等待事件发生
        int ret = epoll_wait(epfd, events, 10, -1);
        if (ret < 0)
        {
            printf("epoll_wait filed\n");
            exit(-1);
        }
        int i;

        //循环遍历数组，做事件的处理
        for (i = 0; i < ret; i++)
        {
            //监听到新连接
            if (events[i].data.fd == sfd)
            {
                newfd = accept(sfd, (struct sockaddr *)&cin, &len);
                if (newfd < 0)
                {
                    perror("accept");
                    return -1;
                }
                printf("[%s:%d] 客户端连接成功 newfd=%d __%d__\n",
                       inet_ntoa(cin.sin_addr), ntohs(cin.sin_port), newfd, __LINE__);

                savecin[newfd] = cin;

                //新客户端套接字加入epoll
                event.events = EPOLLIN;
                event.data.fd = newfd;
                if (epoll_ctl(epfd, EPOLL_CTL_ADD, newfd, &event) < 0)
                {
                    printf("epoll_ctl add filed\n");
                }
            }
            else if (events[i].data.fd == 0) //键盘输入事件
            {
                printf("触发键盘输入事件 __%d__\n", __LINE__);
                int sndfd = -1;
                res = scanf("%d %s", &sndfd, buf);
                while (getchar() != 10)
                    ;
                if (res != 2)
                {
                    printf("请输入正确数据格式:fd string\n");
                    continue;
                }
            }
            else
            {
                //客户端交互事件
                printf("触发客户端交互事件__%d__\n", __LINE__);
                bzero(buf, sizeof(buf));
                //接收数据
                res = recv(events[i].data.fd, buf, sizeof(buf), 0);
                if (res < 0)
                {
                    ERR_MSG("recv");
                    return -1;
                }
                else if (0 == res)
                {
                    printf("[%s:%d] 客户端下线 newfd=%d __%d__\n",
                           inet_ntoa(savecin[i].sin_addr), ntohs(savecin[i].sin_port), i, __LINE__);

                    close(i); //未接收到数据，关闭文件描述符
                    continue; //进入下一次循环
                }

                //发送数据
                strcat(buf, "*_*");
                if (send(events[i].data.fd, buf, sizeof(buf), 0) < 0)
                {
                    ERR_MSG("send");
                    return -1;
                }
                printf("发送成功\n");
            }
        }
    }
    if (close(sfd) < 0)
    {
        ERR_MSG("close");
        return -1;
    }

    return 0;
}

---

驱动程序：

#include 
#include 
#include
#include
#include
#include
#include
struct class *cls;
struct device *dev;
unsigned int major;//定义一个变量保存主设备号
char kbuf[128]={0};
//定义等待队列头
wait_queue_head_t wq_head;
int condition=0;//数据是否准备好的标志变量
//封装操作方法
int mycdev_open(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}
ssize_t mycdev_read(struct file *file, char  *ubuf, size_t size, loff_t *lof)
{
     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
      if(size>sizeof(kbuf))//用户的需求内核满足不了
     {
        size=sizeof(kbuf);
     }
      long ret;
     ret=copy_to_user(ubuf,kbuf,size);
     if(ret)
     {
        printk("copy_to_user filed\n");
        return -EIO;
     }
     condition=0;//表示下一次数据没有准备好
    return 0;
}
ssize_t mycdev_write(struct file *file, const char  *ubuf, size_t size, loff_t *lof)
{
     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
     if(size>sizeof(kbuf))//用户的需求内核满足不了
     {
        size=sizeof(kbuf);
     }
      long ret;
     ret=copy_from_user(kbuf,ubuf,size);//表示模拟硬件数据就绪
     if(ret)
     {
        printk("copy_from_user filed\n");
        return -EIO;
     }
     condition=1;
     wake_up_interruptible(&wq_head);//唤醒休眠的进程
     
    return 0;
}
//封装poll方法
__poll_t mycdev_poll(struct file *file, struct poll_table_struct *wait)
{
    __poll_t mask=0;
    //1.向上提交等待队列头
    poll_wait(file,&wq_head,wait);
    //2.根据事件是否发生给一个合适的返回值
    if(condition)
    {
        mask=POLLIN;
    }
    return mask;
}
int mycdev_close(struct inode *inode, struct file *file)
{
     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}
//定义一个操作方法结构体变量并且初始化
struct file_operations fops={
    .open=mycdev_open,
    .release=mycdev_close,
    .read=mycdev_read,
    .poll=mycdev_poll,
    .write=mycdev_write,
};
static int __init mycdev_init(void)
{
    //初始化等待队列头
    init_waitqueue_head(&wq_head);
    //注册字符设备驱动
    major=register_chrdev(0,"mychrdev",&fops);
    if(major<0)
    {
        printk("注册字符设备驱动失败\n");
        return major;
    }
    printk("注册字符设备驱动成功major=%d\n",major);
    // 向上提交目录
    cls = class_create(THIS_MODULE, "myled");
    if (IS_ERR(cls))
    {
        printk("向上提交目录失败\n");
        return -PTR_ERR(cls);
    }
    printk("向上提交目录信息成功\n");
    // 向上提交设备节点信息
   
        dev = device_create(cls, NULL, MKDEV(major, 0), NULL, "mycdev");
        if (IS_ERR(dev))
        {
            printk("向上提交设备节点信息失败\n");
            return -PTR_ERR(dev);
        }
    printk("向上提交设备节点成功\n");
    return 0;
}
static void __exit mycdev_exit(void)
{
    // 销毁节点信息
    
        device_destroy(cls, MKDEV(major, 0));
  
    // 销毁目录信息
    class_destroy(cls);
    //注销字符设备驱动
    unregister_chrdev(major,"mychrdev");

}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");