非阻塞，et模型 epoll

曾经终败给现在 2021-11-09 10:04 231阅读 0赞

#include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/socket.h>
    #include <sys/epoll.h>
    #include <netinet/in.h>
    #include <unistd.h>
    #include <arpa/inet.h>
    #include <fcntl.h>
    #include <errno.h>
    
    
    #define MAX_EVENTS 100
    #define MAX_BUFFER_SIZE 10
    
    
    /*设置非阻塞*/
    int setNonBlock(int fd)
    {
    	int old_flag = fcntl(fd, F_GETFL);
    	fcntl(fd, F_SETFL, old_flag | O_NONBLOCK);
    	return old_flag;	
    }
    
    
    /*添加到epoll池中*/
    void addfd_to_epoll(int epfd, int fd)
    {
    	struct epoll_event event;
    	event.data.fd = fd;
    	event.events = EPOLLIN | EPOLLET;
    
    
    	setNonBlock(fd);
    
    
    	epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &event);
    }
    
    
    
    
    void err_exit(char *msg)
    {
    	perror(msg);
    	exit(1);
    }
    
    
    int create_socket(char *ip, int port)
    {
    	struct sockaddr_in addr;
    	int sockfd, reuse = 1;
    
    
    	memset(&addr, 0, sizeof(sockaddr_in));
    	addr.sin_family = AF_INET;
    	addr.sin_port = htons(port);
    	
    	if(inet_pton(PF_INET, ip, &addr.sin_addr) == -1)
    	{
    		err_exit("inet_pton() error");
    	}
    
    
    	if((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1)
    	{
    		err_exit("socket() error");
    	}
    
    
    	if(-1 == setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)))
    	{
    		err_exit("setsockopt() error");
    	}
    
    
    	if(-1 == bind(sockfd, (struct sockaddr*)&addr, sizeof(addr)))
    	{
    		err_exit("bind() error");
    	}
    
    
    	//待处理连接最大5
    	if(-1 == listen(sockfd, 5))
    	{
    		err_exit("listen() error");
    	}
    	return sockfd;
    }
    
    
    void epoll_process(int epfd, struct epoll_event *events, int num, int listenfd)
    {
    	struct sockaddr addr;
    	int newfd, confd;
    	socklen_t len;
    
    
    	for(int i = 0; i < num; ++i)
    	{
    		newfd = events[i].data.fd;
    		if(newfd == listenfd)
    		{
    			confd = accept(listenfd, &addr, &len);
    			addfd_to_epoll(epfd, confd);
    		}
    		else
    		{
    			printf("开始接受客户端%d数据 \n", newfd);
    			//et的循环接受数据 
    			char szBuf[MAX_BUFFER_SIZE + 1];
    			while(1)
    			{
    				memset(&szBuf, 0, sizeof(szBuf));
    				int ret = recv(newfd, szBuf, MAX_BUFFER_SIZE, 0);
    				if(ret == 0)
    				{
    					printf("客户端主动关闭请求\n");
    					close(newfd);
    					break;
    				}
    				else if(ret == -1)
    				{
    					if(errno == EAGAIN || errno == EWOULDBLOCK)
    					{
    						printf("循环读取完了所有的数据 \n");
    						break;
    					}
    					else if(104 == errno) //connetction reset by peer
    					{
    						printf("客户端主动关闭请求\n");
    					}
    					close(newfd);
    					break;
    				}
    				else
    				{
    					printf("接受到数据%d字节，数据: %s\n", ret, szBuf);
    				}
    			}
    		}
    	}
    }
    
    
    int main(int argc, char** argv)
    {
    	if(argc < 3)
    	{
    		fprintf(stderr, "usage:%s ip_address port_number\n", argv[0]);
    		exit(0);
    	}
    
    
    	int listenfd, epfd;
    	listenfd = create_socket(argv[1], atoi(argv[2]));
    
    
    	epfd = epoll_create(100000);
    	if(-1 == epfd) exit(-1);
    
    
    	addfd_to_epoll(epfd, listenfd);
    
    
    	struct epoll_event events[MAX_EVENTS + 1];
    	while(1)
    	{
    		int num = epoll_wait(epfd, events, MAX_EVENTS, 0);
    		if(num == -1)
    		{
    			err_exit("epoll_wait() error");
    		}
    		else
    		{
    			epoll_process(epfd, events, num, listenfd); 
    		}
    		usleep(10);
    	}
    	
    	close(listenfd);
    
    
    	return 0;
    }

转载于:https://www.cnblogs.com/JesonYang/p/6124114.html