2023.7.30(epoll实现并发服务器)

服务器

#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <sys/types.h> 
#include <unistd.h>
#define ERR(msg)                                       	   \
	do {                                                   \
		printf("%s %s %d:", __FILE__, __func__, __LINE__); \
		perror(msg);                                       \
		exit(-1);                                          \
	} while (0)
//端口号的网络字节序 1024~49151
#define PORT 6666 //设置端口号6666
#define IP "192.168.250.100"//设置本机IP
#define N 32
int main(int argc, char* argv[])
{
	// 1.创建红黑树
	int epfd = epoll_create(1);
	if (epfd < 0) {
		ERR("epfd err");
	}
	// 2.创建套接字
	int socketfd;
	if (-1 == (socketfd = socket(AF_INET, SOCK_STREAM, 0))) {
		ERR("socket error");
	}
	// 3.struct epoll_event event
	struct epoll_event event;
	event.events = EPOLLIN | EPOLLET;
	event.data.fd = socketfd;
	if (epoll_ctl(epfd, EPOLL_CTL_ADD, socketfd, &event) < 0) {
		ERR("epoll_ctl error");
	}
	// 填充服务器地址
	struct sockaddr_in serveraddr, clientaddr;
	serveraddr.sin_family = AF_INET;
	serveraddr.sin_port = htons(PORT);
	serveraddr.sin_addr.s_addr = inet_addr(IP);
	socklen_t serveraddr_len = sizeof(serveraddr);
	socklen_t clientaddr_len = sizeof(clientaddr_len);
	// 绑定
	if (bind(socketfd, (struct sockaddr*)&serveraddr, serveraddr_len) < 0) 
	{
		ERR("bind error");
	}
	// 监听
	if (listen(socketfd, 10) < 0) 
	{
		ERR("listen errorG");
	}
	int acceptfd, ret, i;
	int bytes;
	struct epoll_event events[20];
	char buf[N] = {0};
	while (1) 
	{
		//使用epoll_wait 检测文件描述符是否发生
		ret = epoll_wait(epfd, events, 20, -1);
		if (ret > 0) 
		{
			for (i = 0; i < ret; i++) 
			{
				// 判断文件描述符数量
				if (events[i].data.fd == socketfd) 
				{
					// 判断对应文件描述符的IO类型
					if (events[i].events & EPOLLIN) 
					{
						acceptfd = accept(events[i].data.fd, (struct sockaddr*)&clientaddr, &clientaddr_len);
						if (acceptfd < 0) 
						{
							ERR("accept error");
						}
						printf("IP:%s 连接成功\n", (char*)inet_ntoa(clientaddr.sin_addr));
						// 将新客户端通信套接字挂到树上
						struct epoll_event event;
						event.events = EPOLLIN | EPOLLET;
						event.data.fd = acceptfd;
						if (epoll_ctl(epfd, EPOLL_CTL_ADD, acceptfd, &event) < 0) 
						{
							ERR("epoll_ctl err");
						}
					}
				} 
				else 
				{
					// 处理客户端信息
					if (EPOLLIN & events[i].events == EPOLLIN) 
					{
						memset(buf, 0, sizeof(buf));
						if (-1 == (bytes = recv(events[i].data.fd, buf, sizeof(buf), 0))) 
						{
							ERR("recv error");
						} 
						else if (bytes == 0) 
						{
							// 客户端断开信息
							printf("acceptfd:%d 断开连接\n", events[i].data.fd);
							// 关闭对应文件描述符
							close(events[i].data.fd);
							// 实现对于epoll的控制
							epoll_ctl(epfd, EPOLL_CTL_DEL, events[i].data.fd, NULL);
						}
						else 
						{
							printf("buf:%s\n", buf);
						}
						if (-1 == send(events[i].data.fd, buf, N, 0)) 
						{
							ERR("send error");
						}
					}
				}
			}
		} 
		else 
		{
			ERR("epoll_wait error");
		}
	}
	close(socketfd);
	return 0;

客户端

#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
 
#define ERR(msg)                                        \
    do {                                                   \
        printf("%s %s %d:", __FILE__, __func__, __LINE__); \
        perror(msg);                                       \
        exit(-1);                                          \
    } while (0)
 
#define N 32
//端口号网络字节序
#define PORT 6666   
#define IP "192.168.250.100"
int main(int argc, const char* argv[])
{
 
    // 1.创建套接字
    int sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (-1 == sockfd) {
        ERR("socket error");
    }
 
    // 2.填充服务器网络信息结构体
    struct sockaddr_in serveraddr;
    memset(&serveraddr, 0, sizeof(serveraddr));
    serveraddr.sin_family = AF_INET;
    serveraddr.sin_port = htons(PORT);
    serveraddr.sin_addr.s_addr = inet_addr(IP);
 
    socklen_t serveraddr_len = sizeof(serveraddr);
 
    char buf[N] = {0};
    int res = 0;
 
    // 3.尝试与服务器建立连接
    if (-1 == connect(sockfd, (struct sockaddr*)&serveraddr, serveraddr_len)) 
	{
        ERR("connect error");
    }
    printf("与服务器建立连接成功..\n");
    while (1) 
	{
        memset(buf, 0, sizeof(buf));
        fgets(buf, N, stdin);
        buf[strlen(buf) - 1] = '\0'; //清理结尾的\n
 
        //发送数据
        if (-1 == send(sockfd, buf, sizeof(buf), 0)) 
		{
            ERR("send error");
        }
        //接收服务器的应答信息
        if (-1 == (res = recv(sockfd, buf, sizeof(buf), 0))) 
		{
            ERR("recv error");
        }
        if (0 == res) 
		{
            break;
        }
        //输出应答信息
        printf("应答为:[%s]\n", buf);
    }
    //关闭套接字
    close(sockfd);
 
    return 0;

}