简单的epoll模型

程序员文章站 2024-03-23 10:18:16

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水平触发模式

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <sys/epoll.h>

int main(int argc,const char* argv[]){
	if(argc < 2){
		printf("eg: ./a.out port\n");
		exit(1);
	}

	struct sockaddr_in serv_addr;
	socklen_t serv_len = sizeof(serv_addr);
	int port = atoi(argv[1]);

	//创建套接字
	int lfd = socket(AF_INET,SOCK_STREAM,0);
	//初始化socket_in
	memset(&serv_addr,0,serv_len);
	serv_addr.sin_family = AF_INET;					//地址族
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);	//监听本机所有的IP
	serv_addr.sin_port = htons(port); 				//设置端口

	//绑定端口和IP
	bind(lfd,(struct sockaddr*)&serv_addr,serv_len);

	//设置同时监听的最大个数
	listen(lfd,36);
	printf("start accept ...\n");

	struct sockaddr_in client_addr;
	socklen_t cli_len = sizeof(client_addr);

	//创建epoll树根节点
	int epfd = epoll_create(2000);
	//初始化epoll树
	struct epoll_event ev;
	ev.events = EPOLLIN;	//边沿模式;
	ev.data.fd = lfd;
	epoll_ctl(epfd,EPOLL_CTL_ADD,lfd,&ev);
	struct epoll_event all[2000];	
	while(1){
		//使用epoll通知内核fd文件IO检测
		int ret = epoll_wait(epfd,all,sizeof(all)/sizeof(all[0]),-1);
		int i;
		for(i=0;i<ret;++i){
			//遍历all数组中的前ret个元素
			int fd = all[i].data.fd;
			//判断是否有新连接
			if(fd == lfd){
				//有新连接
				int cfd = accept(lfd,(struct sockaddr*)&client_addr,&cli_len);
				if(cfd == -1){
					perror("accept error");
					exit(-1);
				}
				//将新得到的cfd上epoll树
				ev.events = EPOLLIN;
				ev.data.fd = cfd;
				epoll_ctl(epfd,EPOLL_CTL_ADD,cfd,&ev);
				//打印客户端信息
				char ip[64] = {0};
				printf("New Client IP: %s, Port: %d\n", 
					inet_ntop(AF_INET,&client_addr.sin_addr.s_addr,ip,sizeof(ip)),
					ntohs(client_addr.sin_port));
			}else{
				//处理已连接的客户端发过来的数据
				if(!all[i].events & EPOLLIN){
					//如果没有读的操作那么跳过
					continue;
				}
				//读数据
				char buf[1024] = {0};
				int len = recv(fd,buf,sizeof(buf),0);
				if(len == -1){
					perror("recv error");
					exit(1);
				}else if(len ==0){
					//客户端关闭
					printf("client disconnected...\n");
					//下树
					ret = epoll_ctl(epfd,EPOLL_CTL_DEL,fd,NULL);
					if(ret == -1){
						perror("epoll_ctl - del error");
						exit(1);
					}
					close(fd);
				}else{
					//正常情况
					printf("recv buf: %s\n",buf);
					//回给客户端数据
					write(fd,buf,len);
				}
			}
		}
	}

	close(lfd);
	return 0;
}

边沿模式

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <sys/epoll.h>

int main(int argc,const char* argv[]){
	if(argc < 2){
		printf("eg: ./a.out port\n");
		exit(1);
	}

	struct sockaddr_in serv_addr;
	socklen_t serv_len = sizeof(serv_addr);
	int port = atoi(argv[1]);

	//创建套接字
	int lfd = socket(AF_INET,SOCK_STREAM,0);
	//初始化socket_in
	memset(&serv_addr,0,serv_len);
	serv_addr.sin_family = AF_INET;					//地址族
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);	//监听本机所有的IP
	serv_addr.sin_port = htons(port); 				//设置端口

	//绑定端口和IP
	bind(lfd,(struct sockaddr*)&serv_addr,serv_len);

	//设置同时监听的最大个数
	listen(lfd,36);
	printf("start accept ...\n");

	struct sockaddr_in client_addr;
	socklen_t cli_len = sizeof(client_addr);

	//创建epoll树根节点
	int epfd = epoll_create(2000);
	//初始化epoll树
	struct epoll_event ev;
	ev.events = EPOLLIN | EPOLLET;	//边沿模式;
	ev.data.fd = lfd;
	epoll_ctl(epfd,EPOLL_CTL_ADD,lfd,&ev);
	struct epoll_event all[2000];	
	while(1){
		//使用epoll通知内核fd文件IO检测
		int ret = epoll_wait(epfd,all,sizeof(all)/sizeof(all[0]),-1);
		int i;
		for(i=0;i<ret;++i){
			//遍历all数组中的前ret个元素
			int fd = all[i].data.fd;
			//判断是否有新连接
			if(fd == lfd){
				//有新连接
				int cfd = accept(lfd,(struct sockaddr*)&client_addr,&cli_len);
				if(cfd == -1){
					perror("accept error");
					exit(1);
				}
				//将新得到的cfd上epoll树
				ev.events = EPOLLIN | EPOLLET;	//边沿模式;
				ev.data.fd = cfd;
				epoll_ctl(epfd,EPOLL_CTL_ADD,cfd,&ev);
				//打印客户端信息
				char ip[64] = {0};
				printf("New Client IP: %s, Port: %d\n", 
					inet_ntop(AF_INET,&client_addr.sin_addr.s_addr,ip,sizeof(ip)),
					ntohs(client_addr.sin_port));
			}else{
				//处理已连接的客户端发过来的数据
				if(!all[i].events & EPOLLIN){
					//如果没有读的操作那么跳过
					continue;
				}
				//读数据
				char buf[1024] = {0};
				int len = recv(fd,buf,sizeof(buf),0);
				if(len == -1){
					perror("recv error");
					exit(-1);
				}else if(len ==0){
					//客户端关闭
					printf("client disconnected...\n");
					//下树
					ret = epoll_ctl(epfd,EPOLL_CTL_DEL,fd,NULL);
					if(ret == -1){
						perror("epoll_ctl - del error");
						exit(1);
					}
					close(fd);
				}else{
					//正常情况
					printf("recv buf: %s\n",buf);
					//回给客户端数据
					write(fd,buf,len);
				}
			}
		}
	}

	close(lfd);
	return 0;
}

边沿非阻塞模式

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <sys/epoll.h>
#include <fcntl.h>
#include <errno.h>


int main(int argc,const char* argv[]){
	if(argc < 2){
		printf("eg: ./a.out port\n");
		exit(1);
	}

	struct sockaddr_in serv_addr;
	socklen_t serv_len = sizeof(serv_addr);
	int port = atoi(argv[1]);

	//创建套接字
	int lfd = socket(AF_INET,SOCK_STREAM,0);
	//初始化socket_in
	memset(&serv_addr,0,serv_len);
	serv_addr.sin_family = AF_INET;					//地址族
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);	//监听本机所有的IP
	serv_addr.sin_port = htons(port); 				//设置端口

	//绑定端口和IP
	bind(lfd,(struct sockaddr*)&serv_addr,serv_len);

	//设置同时监听的最大个数
	listen(lfd,36);
	printf("start accept ...\n");

	struct sockaddr_in client_addr;
	socklen_t cli_len = sizeof(client_addr);

	//创建epoll树根节点
	int epfd = epoll_create(2000);
	//初始化epoll树
	struct epoll_event ev;
	ev.events = EPOLLIN;	
	ev.data.fd = lfd;
	epoll_ctl(epfd,EPOLL_CTL_ADD,lfd,&ev);
	struct epoll_event all[2000];	
	while(1){
		//使用epoll通知内核fd文件IO检测
		int ret = epoll_wait(epfd,all,sizeof(all)/sizeof(all[0]),-1);
		int i;
		for(i=0;i<ret;++i){
			//遍历all数组中的前ret个元素
			int fd = all[i].data.fd;
			//判断是否有新连接
			if(fd == lfd){
				//有新连接
				int cfd = accept(lfd,(struct sockaddr*)&client_addr,&cli_len);
				if(cfd == -1){
					perror("accept error");
					exit(-1);
				}
				//设置cfd为非阻塞模式
				int flag = fcntl(cfd,F_GETFL);
				flag |= O_NONBLOCK;
				fcntl(cfd,F_SETFL,flag);
				//将新得到的cfd上epoll树
				ev.events = EPOLLIN | EPOLLET; //边沿模式
				ev.data.fd = cfd;
				epoll_ctl(epfd,EPOLL_CTL_ADD,cfd,&ev);
				//打印客户端信息
				char ip[64] = {0};
				printf("New Client IP: %s, Port: %d\n", 
					inet_ntop(AF_INET,&client_addr.sin_addr.s_addr,ip,sizeof(ip)),
					ntohs(client_addr.sin_port));
			}else{
				//处理已连接的客户端发过来的数据
				if(!all[i].events & EPOLLIN){
					//如果没有读的操作那么跳过
					continue;
				}
				//读数据
				char buf[1024] = {0};
				int len;
				while((len = recv(fd,buf,sizeof(buf),0))>0){
					write(STDOUT_FILENO,buf,len);
					//发送给客户端
					send(fd,buf,len,0);
				}

				if(len == -1){
					if(errno == EAGAIN){
						printf("\n缓冲区读完\n");
					}else{
						perror("recv error");
						exit(1);
					}
				}else if(len ==0){
					//客户端关闭
					printf("client disconnected...\n");
					//下树
					ret = epoll_ctl(epfd,EPOLL_CTL_DEL,fd,NULL);
					if(ret == -1){
						perror("epoll_ctl - del error");
						exit(1);
					}
					close(fd);
				}
			}
		}
	}

	close(lfd);
	return 0;
}

可以使用nc进行测试

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