epoll

最新推荐文章于 2025-12-05 11:26:35 发布

最新推荐文章于 2025-12-05 11:26:35 发布 · 64 阅读

文章标签：

了解之后才发现epoll服务器的主线程其实最好和处理业务的代码分开,
也就是说:
epoll响应外界的io请求,当epoll得到一个请求的时候,扔到一个消息队列中,然后epoll直接返回,再去等待io请求.而消息队列会通知多个线程去处理这些业务逻辑.

epoll第一次用,消息队列更是第一次用,开始一直在想,怎么写个阻塞的队列,而且要有主动通知的功能,想了一会儿发现pthread_cond_wait和pthread_cond_signal可以实现,于是就简单的试试,下面的代码已经可以实现我刚才想要得到的那个模型,细节就不管了.

---------------------------------------------------------------------------------------------------*/

#include <sys/socket.h>
#include <sys/epoll.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <pthread.h>
#include <errno.h>

#define PORT 8888
#define MAXFDS 5000
#define EVENTSIZE 100

#define BUFFER "HTTP/1.1 200 OK/r/nContent-Length: 5/r/nConnection: close/r/nContent-Type: text/html/r/n/r/nHello"

int epfd;
void *serv_epoll(void *p);
void setnonblocking(int fd)
{
int opts;
opts=fcntl(fd, F_GETFL);
if (opts < 0)
{
fprintf(stderr, "fcntl failed/n");
return;
}
opts = opts | O_NONBLOCK;
if(fcntl(fd, F_SETFL, opts) < 0)
{
fprintf(stderr, "fcntl failed/n");
return;
}
return;
}

int main(int argc, char *argv[])
{
int fd, cfd,opt=1;
struct epoll_event ev;
struct sockaddr_in sin, cin;
socklen_t sin_len = sizeof(struct sockaddr_in);
pthread_t tid;
pthread_attr_t attr;

epfd = epoll_create(MAXFDS);
if ((fd = socket(AF_INET, SOCK_STREAM, 0)) <= 0)
{
fprintf(stderr, "socket failed/n");
return -1;
}
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (const void*)&opt, sizeof(opt));

memset(&sin, 0, sizeof(struct sockaddr_in));
sin.sin_family = AF_INET;
sin.sin_port = htons((short)(PORT));
sin.sin_addr.s_addr = INADDR_ANY;
if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)) != 0)
{
fprintf(stderr, "bind failed/n");
return -1;
}
if (listen(fd, 32) != 0)
{
fprintf(stderr, "listen failed/n");
return -1;
}

pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED);
if (pthread_create(&tid, &attr, serv_epoll, NULL) != 0)
{
fprintf(stderr, "pthread_create failed/n");
return -1;
}

while ((cfd = accept(fd, (struct sockaddr *)&cin, &sin_len)) > 0)
{
setnonblocking(cfd);
ev.data.fd = cfd;
ev.events = EPOLLIN | EPOLLET | EPOLLERR | EPOLLHUP | EPOLLPRI;
epoll_ctl(epfd, EPOLL_CTL_ADD, cfd, &ev);
//printf("connect from %s/n",inet_ntoa(cin.sin_addr));
//printf("cfd=%d/n",cfd);
}

if (fd > 0)
close(fd);
return 0;
}

void *serv_epoll(void *p)
{
int i, ret, cfd, nfds;;
struct epoll_event ev,events[EVENTSIZE];
char buffer[512];

while (1)
{
nfds = epoll_wait(epfd, events, EVENTSIZE , -1);
//printf("nfds ........... %d/n",nfds);
for (i=0; i<nfds; i++)
{
if(events[i].events & EPOLLIN)
{
cfd = events[i].data.fd;
ret = recv(cfd, buffer, sizeof(buffer),0);
//printf("read ret..........= %d/n",ret);

ev.data.fd = cfd;
ev.events = EPOLLOUT | EPOLLET;
epoll_ctl(epfd, EPOLL_CTL_MOD, cfd, &ev);
}
else if(events[i].events & EPOLLOUT)
{
cfd = events[i].data.fd;
ret = send(cfd, BUFFER, strlen(BUFFER), 0);
//printf("send ret...........= %d/n", ret);

ev.data.fd = cfd;
epoll_ctl(epfd, EPOLL_CTL_DEL, cfd, &ev);

close(cfd);

}

else
{

cfd = events[i].data.fd;
ev.data.fd = cfd;
epoll_ctl(epfd, EPOLL_CTL_DEL, cfd, &ev);
close(cfd);
}

}
}
return NULL;
}