/**
张亚霏修改

文件名:epoll_demo.c
编译: gcc epoll_demo.c -pthread


程序源码如下(请自行编辑宏定义SERVER_IP为自己的IP):
*/


/*Linux 2.6 x86_64 only*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <time.h>
#include <sys/epoll.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netdb.h>
#include <pthread.h>
#include <errno.h>

/*线程池的线程数量*/
#define THREAD_MAX 1

/*监听端口*/
#define LISTEN_PORT 8000

/*
监听端口的数量,从LISTEN_PORT到LISTEN_PORT+LISTEN_MAX-1
*/
#define LISTEN_MAX 1


#define SERVER_IP "127.0.0.1"


typedef struct
{
    char	ip4[128];
    int		port;
    int		fd;
} listen_info;



//服务器参数
static listen_info s_listens[LISTEN_MAX];

//线程池参数
static unsigned int s_thread_para[THREAD_MAX][8];//线程参数
static pthread_t s_tid[THREAD_MAX];//线程ID
pthread_mutex_t s_mutex[THREAD_MAX];//线程锁


//私有函数
static int init_thread_pool(void);
static int init_listen4(char *ip4, int port, int max_link);

//线程函数
void* test_server4(unsigned int thread_para[]);

int main(int argc, char *argv[])//客户端驱动
{
    //临时变量
    int            i, j, rc;

    int            sock_listen;    //监听套接字
    int            sock_cli;    //客户端连接
    int            listen_index;

    int            epfd;
    int			nfds;
    struct epoll_event    ev;
    struct epoll_event    events[LISTEN_MAX];

    socklen_t        addrlen;    //地址信息长度
    struct sockaddr_in    addr4;        //IPv4地址结构




    //线程池初始化
    rc = init_thread_pool();
    if (0 != rc)
	exit(-1);

    //初始化服务监听
    for (i = 0; i < LISTEN_MAX; i++)
    {
        sprintf(s_listens[i].ip4, "%s", SERVER_IP);
        s_listens[i].port = LISTEN_PORT + i;
        //创建监听
        rc = init_listen4(s_listens[i].ip4, s_listens[i].port, 64);
        if (0 > rc)
        {
            fprintf(stderr, "无法创建服务器监听于%s:%d\n", s_listens[i].ip4, s_listens[i].port);
            perror(NULL);
            exit(-1);
        }
        s_listens[i].fd = rc;
    }

    //设置集合
    epfd = epoll_create(8192);
    for (i = 0; i < LISTEN_MAX; i++)
    {
        //加入epoll事件集合
        ev.events = EPOLLIN;
        ev.data.u32 = i;//记录listen数组下标
        if (epoll_ctl(epfd, EPOLL_CTL_ADD, s_listens[i].fd, &ev) < 0)
        {
            fprintf(stderr, "向epoll集合添加套接字失败(fd =%d)\r\n", rc);
            exit(-1);
        }
    }


    //服务循环
    for ( ; ; )
    {
        //等待epoll事件
        nfds = epoll_wait(epfd, events, LISTEN_MAX, -1);
        //处理epoll事件
        for (i = 0; i < nfds; i++)
        {
            //接收客户端连接
            listen_index = events[i].data.u32;
            sock_listen = s_listens[listen_index].fd;
            addrlen = sizeof(struct sockaddr_in);
            bzero(&addr4, addrlen);
            sock_cli = accept(sock_listen, (struct sockaddr *)&addr4, &addrlen);
            if (0 > sock_cli)
            {
                fprintf(stderr, "接收客户端连接失败\n");
                continue;
            }
            //查询空闲线程对
            for (j = 0; j < THREAD_MAX; j++)
            {
                if (0 == s_thread_para[j][0]) break;
            }
            if (j >= THREAD_MAX)
            {
                fprintf(stderr, "线程池已满, 连接将被放弃\r\n");
                shutdown(sock_cli, SHUT_RDWR);
                close(sock_cli);
                continue;
            }
            //复制有关参数
            s_thread_para[j][0] = 1;//设置活动标志为"活动"
            s_thread_para[j][1] = sock_cli;//客户端连接
            s_thread_para[j][2] = listen_index;//服务索引
            //线程解锁
            pthread_mutex_unlock(s_mutex + j);
        }//end of for(i;;)
    }//end of for(;;)

    exit(0);
}

static int init_thread_pool(void)
{
    int    i, rc;

    //初始化线程池参数
    for (i = 0; i < THREAD_MAX; i++)
    {
        s_thread_para[i][0] = 0;//设置线程占用标志为"空闲"
        s_thread_para[i][7] = i;//线程池索引
        pthread_mutex_lock(s_mutex + i);//线程锁
    }

    //创建线程池
    for (i = 0; i < THREAD_MAX; i++)
    {
        rc = pthread_create(s_tid + i, 0, (void *)test_server4, (void *)(s_thread_para[i]));
        if (0 != rc)
        {
            fprintf(stderr, "线程创建失败\n");
            return(-1);
        }
    }

    //成功返回
    return(0);
}

static int init_listen4(char *ip4, int port, int max_link)
{
    //临时变量
    int            sock_listen4;
    struct sockaddr_in    addr4;
    unsigned int        optval;
    struct linger        optval1;

    //初始化数据结构
    bzero(&addr4, sizeof(addr4));
    inet_pton(AF_INET, ip4, &(addr4.sin_addr));
    addr4.sin_family = AF_INET;
    addr4.sin_port = htons(port);

    //创建SOCKET
    sock_listen4 = socket(AF_INET, SOCK_STREAM, 0);
    if (0 > sock_listen4) return(-1);

    //设置SO_REUSEADDR选项(服务器快速重起)
    optval = 0x1;
    setsockopt(sock_listen4, SOL_SOCKET, SO_REUSEADDR, &optval, 4);

    //设置SO_LINGER选项(防范CLOSE_WAIT挂住所有套接字)
    optval1.l_onoff = 1;
    optval1.l_linger = 60;
    setsockopt(sock_listen4, SOL_SOCKET, SO_LINGER, &optval1, sizeof(struct linger));

    if (0 > bind(sock_listen4, (struct sockaddr *)&addr4, sizeof(addr4)))
    {
        close(sock_listen4);
        return(-1);
    }

    if (0 > listen(sock_listen4, max_link))
    {
        close(sock_listen4);
        return(-1);
    }

    return(sock_listen4);
}


void * test_server4(unsigned int thread_para[])
{
    //临时变量
    int        pool_index;    //线程池索引
    int        sock_cli;    //客户端连接
    int        listen_index;    //监听索引

    char        buff[32768];    //传输缓冲区
    char        *p;
    int        i, j, len;

    //线程脱离创建者
    pthread_detach(pthread_self());
    pool_index = thread_para[7];

wait_unlock:

    pthread_mutex_lock(s_mutex + pool_index);//等待线程解锁

    //线程变量内容复制
    sock_cli = thread_para[1];//客户端连接
    listen_index = thread_para[2];//监听索引

    //接收请求
    len = recv(sock_cli, buff, 32768, MSG_NOSIGNAL);

    //构造响应
    p = buff;
    //HTTP头
    p += sprintf(p, "HTTP/1.1 200 OK\r\n");
    p += sprintf(p, "Content-Type: text/html\r\n");
    p += sprintf(p, "Connection: closed\r\n\r\n");
    //页面
    p += sprintf(p, "<html>\r\n<head>\r\n");
    p += sprintf(p, "<meta content=\"text/html; charset=GBK\" http-equiv=\"Content-Type\">\r\n");
    p += sprintf(p, "</head>\r\n");
    p += sprintf(p, "<body style=\"background-color: rgb(229, 229, 229);\">\r\n");

    p += sprintf(p, "<center>\r\n");
    p += sprintf(p, "<H3>连接状态</H3>\r\n");
    p += sprintf(p, "<p>服务器地址 %s:%d</p>\r\n", s_listens[listen_index].ip4, s_listens[listen_index].port);
    j = 0;
    for (i = 0; i < THREAD_MAX; i++)
    {
        if (0 != s_thread_para[i][0]) j++;
    }
    p += sprintf(p, "<H3>线程池状态</H3>\r\n");
    p += sprintf(p, "<p>线程池总数 %d 活动线程总数 %d</p>\r\n", THREAD_MAX, j);
    p += sprintf(p, "</center></body></html>\r\n");
    len = p - buff;

    //发送响应
    send(sock_cli, buff, len, MSG_NOSIGNAL);

    //释放连接
    shutdown(sock_cli, SHUT_RDWR);
    close(sock_cli);

    //线程任务结束
    thread_para[0] = 0;//设置线程占用标志为"空闲"
    goto wait_unlock;

    pthread_exit(NULL);
}