//
// Created by jxq on 19-8-7.
//
// socket编程 13 epoll 模型
#include <iostream>
#include <stdio.h>
#include <cstring>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/epoll.h>
#include <poll.h>
#include <vector>
#include <sys/stat.h>
#include <fcntl.h>
#include <algorithm>
using namespace std;
typedef vector<struct epoll_event> EventList;//vector:动态数组
struct packet
{
int len;
char buf[1024];
};
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0);
ssize_t readn(int fd, void *buf, size_t count)
{
size_t nleft = count; // 剩余字节数
ssize_t nread;
char *bufp = (char*) buf;
while (nleft > 0)
{
nread = read(fd, bufp, nleft);
if (nread < 0)
{
if (errno == EINTR)
{
continue;
}
return -1;
} else if (nread == 0)
{
return count - nleft;
}
bufp += nread;
nleft -= nread;
}
return count;
}
ssize_t writen(int fd, const void *buf, size_t count)
{
size_t nleft = count;
ssize_t nwritten;
char* bufp = (char*)buf;
while (nleft > 0)
{
if ((nwritten = write(fd, bufp, nleft)) < 0)
{
if (errno == EINTR)
{
continue;
}
return -1;
}
else if (nwritten == 0)
{
continue;
}
bufp += nwritten;
nleft -= nwritten;
}
return count;
}
ssize_t recv_peek(int sockfd, void *buf, size_t len)
{
while (1)
{
int ret = recv(sockfd, buf, len, MSG_PEEK); // 查看传入消息
if (ret == -1 && errno == EINTR)
{
continue;
}
return ret;
}
}
ssize_t readline(int sockfd, void *buf, size_t maxline)
{
int ret;
int nread;
char *bufp = (char*)buf; // 当前指针位置
int nleft = maxline;
while (1)
{
ret = recv_peek(sockfd, buf, nleft);
if (ret < 0)
{
return ret;
}
else if (ret == 0)
{
return ret;
}
nread = ret;
int i;
for (i = 0; i < nread; i++)
{
if (bufp[i] == '\n')
{
ret = readn(sockfd, bufp, i+1);
if (ret != i+1)
{
exit(EXIT_FAILURE);
}
return ret;
}
}
if (nread > nleft)
{
exit(EXIT_FAILURE);
}
nleft -= nread;
ret = readn(sockfd, bufp, nread);
if (ret != nread)
{
exit(EXIT_FAILURE);
}
bufp += nread;
}
return -1;
}
void echo_srv(int connfd)
{
char recvbuf[1024];
// struct packet recvbuf;
int n;
while (1)
{
memset(recvbuf, 0, sizeof recvbuf);
int ret = readline(connfd, recvbuf, 1024);
if (ret == -1)
{
ERR_EXIT("readline");
}
if (ret == 0)
{
printf("client close\n");
break;
}
fputs(recvbuf, stdout);
writen(connfd, recvbuf, strlen(recvbuf));
}
}
void activate_nonblock(int fd)
{
int ret;
int flags = fcntl(fd, F_GETFL);
if(flags == -1)
ERR_EXIT("fcntl");
flags |= O_NONBLOCK;
ret = fcntl(fd, F_SETFL, flags);
if(ret == -1)
ERR_EXIT("fcntl");
}
int main(int argc, char** argv) {
// 1. 创建套接字
int listenfd;
if ((listenfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
ERR_EXIT("socket");
}
// 2. 分配套接字地址
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof servaddr);
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(6666);
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
// servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
// inet_aton("127.0.0.1", &servaddr.sin_addr);
int on = 1;
// 确保time_wait状态下同一端口仍可使用
if (setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on) < 0) {
ERR_EXIT("setsockopt");
}
// 3. 绑定套接字地址
if (bind(listenfd, (struct sockaddr *) &servaddr, sizeof servaddr) < 0) {
ERR_EXIT("bind");
}
// 4. 等待连接请求状态
if (listen(listenfd, SOMAXCONN) < 0) {
ERR_EXIT("listen");
}
// 5. 允许连接
struct sockaddr_in peeraddr;
socklen_t peerlen;
// 6. 数据交换
int nready;
int connfd;
int i;
vector<int> clients;//保存客户端的已连接套接字
int epollfd;
//EPOLL_CLOEXEC含义:该进程被替换的时候,文件描述会被关闭
epollfd = epoll_create1(EPOLL_CLOEXEC); // 创建一个epoll的实例
struct epoll_event event;
//typedef union epoll_data{...};
//struct epoll_enent{_uint32_t enents; epoll_data data};
//感兴趣的fd是监听listenfd
event.data.fd = listenfd;//data是一个联合体,共用体,共用体的大小是8个字节
event.events = EPOLLIN | EPOLLET;//listenfd感兴趣的事件:EPOLLIN,是否事件到来,EPOLLET表示边沿方式触发
epoll_ctl(epollfd, EPOLL_CTL_ADD, listenfd, &event);//(epoll实例句柄,操作方式,将fd添加至epoll来管理,该fd感兴趣的事件)
EventList events(16);//events数组的初始值为16
while (1)
{
//epoll_wait检测哪一些IO产生了事件,(epoll实例句柄,哪些事件产生了感兴趣的事件,能够返回的最大事件个数,超时时间)
// 等侍注册在epfd上的socket fd的事件的发生,如果发生则将发生的sokct fd和事件类型放入到events数组中
//events.begin()是一个迭代器,可以看成一个指针,*events.begin():取数组第一个元素,类型就是struct epoll_event
//&*events.begin():动态数组的首地址
//不直接使用vents.begin(),是因为他类型是一个迭代器,类型不匹配,编译不通过,取&*就等价于struct epoll_event*
nready = epoll_wait(epollfd, &*events.begin(), static_cast<int>(events.size()), -1); // -1:一直等待,直到有事件产生
if (nready == -1)
{
if (errno == EINTR)
{
continue;
}
ERR_EXIT("epoll_wait");
}
if (nready == 0)
{
continue;
}
//nready:等待到的事件个数
if ((size_t)nready == events.size())//说明容器容量不够大,需要调整容器容量的大小
{
events.resize(events.size()*2);
}
//返回的事件,保存在&*events.begin()中
for (i = 0; i < nready; ++i)//返回了nready个事件
{
//epoll效率比select和poll高的核心:返回的事件保存在events中,通过events可以找到fd,也就是说这些fd产生了事件
//就不需要遍历哪些socket在某个集合中产生了可读事件,因为events指示的fd已经产生了事件
if (events[i].data.fd == listenfd)//listenfd产生了可读事件
{
peerlen = sizeof(peeraddr);
connfd = accept(listenfd, (struct sockaddr*)&peeraddr, &peerlen);
if (connfd == -1)
{
ERR_EXIT("accept");
}
printf("id = %s, ", inet_ntoa(peeraddr.sin_addr));
printf("port = %d\n", ntohs(peeraddr.sin_port));
clients.push_back(connfd);
activate_nonblock(connfd);
event.data.fd = connfd;
event.events = EPOLLIN | EPOLLET;
epoll_ctl(epollfd, EPOLL_CTL_ADD, connfd, &event);
//下一次epoll_wait就有可能产生监听fd和连接fd产生可读事件
}//只需要判断events产生了哪些事件 ,可读,可写?
//不需要遍历哪个fd产生了事件,因为events[i].data.fd中的fd就是产生事件的套接字
else if (events[i].events & EPOLLIN)//已连接fd产生了可读事件
{
connfd = events[i].data.fd;//取出已连接fd
if (connfd < 0)
{
continue;
}
char recvbuf[1024];
int ret = readline(connfd, recvbuf, sizeof(recvbuf));
if (ret == -1)
{
ERR_EXIT("readline");
}
if (ret == 0)//表示对方关闭
{
printf("client close\n");
close(connfd);
event = events[i];//对方关闭,要将该events[i]从epollfd中删除
epoll_ctl(epollfd, EPOLL_CTL_DEL, connfd, &event);
//删除已连接fd
clients.erase(std:remove(clients.begin(), clients.end(), connfd),clients.end());
// clients.erase(
// remove_if(clients.begin(), clients.end(), [connfd](int n){return n == connfd;}),
// clients.end());
}
fputs(recvbuf, stdout);
writen(connfd, recvbuf, strlen(recvbuf));
}
}
}
// 7. 断开连接
close(listenfd);
return 0;
}