多线程和epoll的结合运用示例

//epoll通过将服务socket if (epoll_ctl(kdpfd, EPOLL_CTL_ADD, listener, &ev) < 0) 添加到epoll中
//然后listener监听链接请求，每次监听到一个新的链接就添加到epoll中 epoll_ctl
//如果不是新的链接那么直接创建一个子线程进行业务的处理

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <fcntl.h>
#include <sys/epoll.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <pthread.h>

#define MAXBUF 1024
#define MAXEPOLLSIZE 10000

void pthread_handle_message(void para);
/
setnonblocking - 设置句柄为非阻塞方式
/
int setnonblocking(int sockfd)
{
if (fcntl(sockfd, F_SETFL, fcntl(sockfd, F_GETFD, 0)|O_NONBLOCK) == -1) {
return -1;
}
return 0;
}

static int count111 = 0;
static time_t oldtime = 0, nowtime = 0;

//------------------------------------------------------------
int main(int argc, char **argv)
{
int listener, new_fd, nfds, n, ret;
struct epoll_event ev;
int kdpfd, curfds;
socklen_t len;
struct sockaddr_in my_addr, their_addr;
unsigned int myport, lisnum;
struct epoll_event events[MAXEPOLLSIZE];
struct rlimit rt;

if (argc>1)
    myport = atoi(argv[1]);
else
    myport = 8006;

if (argc>2)
    lisnum = atoi(argv[2]);
else
    lisnum = 10;

/* 设置每个进程允许打开的最大文件数 */
rt.rlim_max = rt.rlim_cur = MAXEPOLLSIZE;
if (setrlimit(RLIMIT_NOFILE, &rt) == -1) {
    perror("setrlimit");
    exit(1);
}
else printf("设置系统资源参数成功！/n");

/* 开启 socket 监听 */
if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
    perror("socket");
    exit(1);
} else
    printf("socket 创建成功！/n");

/*设置socket属性，端口可以重用*/
int opt=SO_REUSEADDR;
setsockopt(listener,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(opt));

/*设置socket为非阻塞模式*/
setnonblocking(listener);

bzero(&my_addr, sizeof(my_addr));
my_addr.sin_family = PF_INET;
my_addr.sin_port = htons(myport);
if (argc>3)
    my_addr.sin_addr.s_addr = inet_addr(argv[3]);
else
    my_addr.sin_addr.s_addr = INADDR_ANY;

if (bind
    (listener, (struct sockaddr *) &my_addr, sizeof(struct sockaddr))
    == -1) {
        perror("bind");
        exit(1);
} else
    printf("IP 地址和端口绑定成功/n");

if (listen(listener, lisnum) == -1) {
    perror("listen");
    exit(1);
} else
    printf("开启服务成功！/n");

/* 创建 epoll 句柄，把监听 socket 加入到 epoll 集合里 */
kdpfd = epoll_create(MAXEPOLLSIZE);
len = sizeof(struct sockaddr_in);
ev.events = EPOLLIN | EPOLLET;
ev.data.fd = listener;
if (epoll_ctl(kdpfd, EPOLL_CTL_ADD, listener, &ev) < 0) {
    fprintf(stderr, "epoll set insertion error: fd=%d/n", listener);
    return -1;
} else
    printf("监听 socket 加入 epoll 成功！/n");
curfds = 1;
while (1)
{
    /* 等待有事件发生 */
    nfds = epoll_wait(kdpfd, events, curfds, -1);
    if (nfds == -1)
    {
        perror("epoll_wait");
        continue;
    }
    /* 处理所有事件 */
    for (n = 0; n < nfds; ++n)
    {
        if (events[n].data.fd == listener)
        {
            new_fd = accept(listener, (struct sockaddr *) &their_addr,
                &len);
            if (new_fd < 0) {
                perror("accept");
                continue;
            } else
            {
                //printf("有连接来自于： %s:%d， 分配的 socket 为:%d/n", inet_ntoa(their_addr.sin_addr), ntohs(their_addr.sin_port), new_fd);

            }
            setnonblocking(new_fd);
            ev.events = EPOLLIN | EPOLLET;
            ev.data.fd = new_fd;
            if (epoll_ctl(kdpfd, EPOLL_CTL_ADD, new_fd, &ev) < 0) {
                fprintf(stderr, "把 socket ‘%d‘ 加入 epoll 失败！%s/n",
                    new_fd, strerror(errno));
                return -1;
            }
            curfds++;
        }
        else
        {
            pthread_attr_t attr;
            pthread_t threadId;

            /*初始化属性值，均设为默认值*/
            pthread_attr_init(&attr);
            pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
            /* 设置线程为分离属性*/
            pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
            if(pthread_create(&threadId,&attr,pthread_handle_message,(void*)&(events[n].data.fd)))
            {
                perror("pthread_creat error!");
                exit(-1);
            }
        }
    }
}
close(listener);
return 0; 

}

void pthread_handle_message(void para)
{
char recvBuf[1024] = {0};
int ret = 999;
int rs = 1;
int socketfd = (int )para;

while(rs)
{
    ret = recv(socketfd,recvBuf,1024,0);// 接受客户端消息

    if(ret < 0)
    {
        //由于是非阻塞的模式,所以当errno为EAGAIN时,表示当前缓冲区已无数据可//读在这里就当作是该次事件已处理过。

        if(errno == EAGAIN)
        {
            printf("EAGAIN\n");
            break;
        }
        else{
            printf("recv error! errno:%d\n", errno);

            close(socketfd);
            break;
        }
    }
    else if(ret == 0)
    {
        // 这里表示对端的socket已正常关闭.
        rs = 0;
    }
    if(ret == sizeof(recvBuf))
        rs = 1; // 需要再次读取
    else
        rs = 0;
}

if(ret>0){
    count111 ++;
    struct tm *today;
    time_t ltime;
    time( &nowtime );

    if(nowtime != oldtime){
        printf("%d\n", count111);
        oldtime = nowtime;
        count111 = 0;
    }

    char buf[1000] = {0};
    sprintf(buf,"HTTP/1.0 200 OK\r\nContent-type: text/plain\r\n\r\n%s","Hello world!\n");
    send(socketfd,buf, strlen(buf),0);
}
close(socketfd);

}

原文地址：https://blog.51cto.com/wenxuehui/2433934