使用C++写一个epoll实例
时间: 2023-03-28 10:03:54 浏览: 114
好的,我可以回答这个问题。以下是一个使用 C 语言编写的 epoll 实例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define MAX_EVENTS 10
#define PORT 808
int main() {
int server_fd, new_socket, epoll_fd, n;
struct sockaddr_in address;
char buffer[1024] = {};
struct epoll_event event, events[MAX_EVENTS];
// 创建 socket
if ((server_fd = socket(AF_INET, SOCK_STREAM, )) == ) {
perror("socket failed");
exit(EXIT_FAILURE);
}
// 设置 socket 地址
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
address.sin_port = htons(PORT);
// 绑定 socket
if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < ) {
perror("bind failed");
exit(EXIT_FAILURE);
}
// 监听 socket
if (listen(server_fd, 3) < ) {
perror("listen failed");
exit(EXIT_FAILURE);
}
// 创建 epoll 实例
if ((epoll_fd = epoll_create1()) < ) {
perror("epoll_create1 failed");
exit(EXIT_FAILURE);
}
// 添加监听事件
event.events = EPOLLIN;
event.data.fd = server_fd;
if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, server_fd, &event) < ) {
perror("epoll_ctl EPOLL_CTL_ADD failed");
exit(EXIT_FAILURE);
}
while (1) {
// 等待事件
n = epoll_wait(epoll_fd, events, MAX_EVENTS, -1);
if (n < ) {
perror("epoll_wait failed");
exit(EXIT_FAILURE);
}
// 处理事件
for (int i = ; i < n; i++) {
if (events[i].data.fd == server_fd) {
// 处理新连接
if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&address)) < ) {
perror("accept failed");
exit(EXIT_FAILURE);
}
// 添加新连接到 epoll 实例
event.events = EPOLLIN;
event.data.fd = new_socket;
if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, new_socket, &event) < ) {
perror("epoll_ctl EPOLL_CTL_ADD failed");
exit(EXIT_FAILURE);
}
printf("New connection, socket fd is %d, ip is : %s, port : %d\n", new_socket, inet_ntoa(address.sin_addr), ntohs(address.sin_port));
} else {
// 处理已连接的 socket
int socket_fd = events[i].data.fd;
int valread = read(socket_fd, buffer, 1024);
if (valread == ) {
// 连接关闭
epoll_ctl(epoll_fd, EPOLL_CTL_DEL, socket_fd, NULL);
close(socket_fd);
printf("Connection closed, socket fd is %d\n", socket_fd);
} else {
// 处理数据
printf("Received message from socket fd %d: %s\n", socket_fd, buffer);
write(socket_fd, buffer, strlen(buffer));
}
}
}
}
return ;
}
```
这个程序创建了一个 socket 并监听端口 808,使用 epoll 实现了异步事件处理。当有新连接时,将其添加到 epoll 实例中,并在有数据可读时处理数据。