20240118（IO多路复用）作业

1> 使用select实现TCP客户端的并发

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 


int main(int argc, const char *argv[])
{
	//create socket
	int csktfd=socket(AF_INET,SOCK_STREAM,0);
	if(csktfd==-1){
		perror("socket error");
		return -1;
	}
	//form address structure
	struct sockaddr_in csin;
	csin.sin_family=AF_INET;
	csin.sin_port=htons(12345);
	csin.sin_addr.s_addr=inet_addr("192.168.122.150");
	//bind
	if(bind(csktfd,(struct sockaddr *)&csin,sizeof(csin))==-1){
		perror("bind error");
		return -1;
	}
	//connect
	struct sockaddr_in ssin;
	ssin.sin_family=AF_INET;
	ssin.sin_port=htons(7890);
	ssin.sin_addr.s_addr=inet_addr("192.168.122.150");
	if(connect(csktfd,(struct sockaddr *)&ssin,sizeof(ssin))==-1){
		perror("connect error");
		return -1;
	}

	//select
	fd_set fds,tmpfds;
	FD_SET(0,&fds);
	FD_SET(csktfd,&fds);
	tmpfds=fds;
	char buf[128]="";
	while(1){
		int slct=select(csktfd+1,&tmpfds,NULL,NULL,NULL); 
		if(FD_ISSET(0,&tmpfds)){
			scanf("%s",buf);
			
			send(csktfd,buf,sizeof(buf),0);
			if(strcmp(buf,"quit")==0) break;
		}
		if(FD_ISSET(csktfd,&tmpfds)){
			bzero(buf,sizeof(buf));
			recv(csktfd,buf,sizeof(buf),0);
			printf("receive message from server:%s\n",buf);
		}

		tmpfds=fds;
	}
	//close socket
	close(csktfd);
	return 0;
}

2> 使用poll实现TCP服务器的并发

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 


int main(int argc, const char *argv[])
{
	//create socket
	int ssktfd=socket(AF_INET,SOCK_STREAM,0);
	if(ssktfd==-1){
		perror("socket error");
		return -1;
	}

	//set socket option to reuse imidiately
	int reuse = 1;
    if(setsockopt(ssktfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)) == -1)
    {
        perror("setsockopt error");
        return -1;
    }
    printf("set socket reusable successfully\n");
	//form address structure
	struct sockaddr_in ssin;
	ssin.sin_family=AF_INET;
	ssin.sin_port=htons(7890);
	ssin.sin_addr.s_addr=inet_addr("192.168.122.150");
	//bind
	if(bind(ssktfd,(struct sockaddr *)&ssin,sizeof(ssin))==-1){
		perror("bind error");
		return -1;
	}
	
	//listen
	if(listen(ssktfd,128)==-1){
		perror("listen error");
		return -1;
	}
	
	//poll
	struct pollfd pfd[1024];
	int pfdlen=sizeof(pfd)/sizeof(struct pollfd);
	pfd[0].fd=0;
	pfd[0].events=POLLIN;
	pfd[1].fd=ssktfd;
	pfd[1].events=POLLOUT;
	struct sockaddr_in sktbuf[1024];

	while(1){
		printf("wait event......\n");
		int res=poll(pfd,pfdlen,-1);
		if(res==-1){
			perror("poll error");
			return -1;
		}else if(res==0){
			printf("timeout\n");
			return -1;
		}

		for(int cli=0;cli3 send and recieve message
			if(pfd[cli].fd>3 && pfd[cli].events==POLLOUT){
				char buf[128]="";
				//recieve message
				//bzero(buf,sizeof(buf));
				int res=recv(cli,buf,sizeof(buf),0);
				//disconnection
				if(res=0){
					close(cli);
					//FD_CLR(cli,&fds);
					//update maxfd
					continue;
				}

				printf("message from[%s:%d]%d:%s\n",inet_ntoa(sktbuf[cli].sin_addr),sktbuf[cli].sin_port,cli,buf);
				//send message back
				strcat(buf,"--**--");
				send(cli,buf,sizeof(buf),0);
			}

		}
	}

	//close socket
	close(ssktfd);
	return 0;
}