使用epoll来做为两个client socket的中转站 - 知否问答 - 万象云+社区

static void handle_accept(int epollfd, int listenfd, cli_t * pclient) { int clifd; struct sockaddr_in cliaddr; pclient->cliaddr = &cliaddr; socklen_t cliaddrlen = sizeof(*(pclient->cliaddr)); clifd = accept(listenfd,(sockaddr*)(pclient->cliaddr),&cliaddrlen); if (clifd == -1) { if ( (errno == EAGAIN) || (errno == EWOULDBLOCK) ) { return; } else { perror("accpet error:"); } } else { report_peer_connected((pclient->cliaddr), cliaddrlen); set_socket_non_blocking(clifd); add_event(epollfd,clifd,EPOLLIN|EPOLLOUT); // add one client read event int nread, nwrite; #if 0 const char * req = "please input the key:\n"; printf("size: %d\n", sizeof(req)); while ((nwrite = write(clifd,req,strlen(req)))<0) { if(nwrite == -1){ if ((errno == EAGAIN) || (errno == EWOULDBLOCK)) { //sleep(1); continue; } else { perror("read error"); exit(1); } } } #endif int times=0; // sleep(3); memset(ibuf, 0, sizeof(buf_t)); //while (((nread = read(clifd,ibuf->buf,MAXSIZE))<0) && (times < 100)) while (((nread = read(clifd,ibuf->buf,MAXSIZE))<0)) { if(nread == -1){ if ((errno == EAGAIN) || (errno == EWOULDBLOCK)) { // usleep(100000); times++; continue; } else { perror("read error"); exit(1); } } } if (nread == 0) { fprintf(stderr, "nread: the client closed\n"); } else { printf("nread: %d, ibuf->buf: %s\n", nread, ibuf->buf); if((strncmp(ibuf->buf , "key123", 6) == 0)) { #ifdef DEBUG printf("get HW connection\n"); #endif pclient->hwfd = clifd; pclient->hwcon = 1; } else { #ifdef DEBUG printf("get SW connection\n"); #endif pclient->swfd.push_back(clifd); (pclient->swconnum)++; delete_event(epollfd,clifd,EPOLLIN); } } } } // HW side reads message from the client static void do_read(int epollfd, int fd, cli_t * pclient) { if((fd == pclient->hwfd)) //if it's hw side { memset(ibuf, 0, sizeof(buf_t)); int nread; nread = read(fd,ibuf->buf,MAXSIZE); if (nread == -1) { perror("read error:"); close(fd); delete_event(epollfd,fd,EPOLLIN); } else if (nread == 0) { fprintf(stderr,"client %s:%d close.\n", inet_ntoa(pclient->cliaddr->sin_addr), ntohs(pclient->cliaddr->sin_port)); close(fd); delete_event(epollfd,fd,EPOLLIN); } else { // get message from HW side { #ifdef DEBUG printf("read message from hw is : %s\n",ibuf->buf); #endif } int nwrite; for(int i=0; i<(pclient->swconnum);i++) { nwrite = write((pclient->swfd[i]),ibuf->buf,nread); } //modify_event(epollfd,fd,EPOLLIN|EPOLLOUT); } } } // HW side writes message to the client static void do_write(int epollfd,int fd, cli_t * pclient) { if((fd == pclient->hwfd)) //if it's hw side { int nwrite; int nread; char towrite[MAXSIZE]; for(int i=0;i<((pclient->swfd).size());i++) { set_socket_non_blocking((pclient->swfd[i])); nread=read((pclient->swfd[i]), obuf->buf, MAXSIZE); if((nread == -1) && ((errno == EAGAIN || errno == EWOULDBLOCK))) { } else { if(nread == -1) { perror("read error:"); pclient->swfd.erase((pclient->swfd).begin()+i); pclient->swconnum--; } else { if(nread == 0) { fprintf(stderr, "client closed.\n"); close(pclient->swfd[i]); pclient->swfd.erase((pclient->swfd).begin()+i); pclient->swconnum--; } else { #ifdef DEBUG printf("write message to hw is : %s\n", obuf->buf); #endif nwrite=write(fd, obuf->buf, nread); } } } } //modify_event(epollfd,fd,EPOLLIN); } } static void handle_events(int epollfd, int listenfd, struct epoll_event * events, int num, cli_t* pclient, TRANSTATE * ts ) { int i; int fd; struct sockaddr_in cliaddr; //*ts = INIT; // wark over the event ready for (i = 0;i < num;i++) { fd = events[i].data.fd; // deal as to different event if ((fd == listenfd) &&(events[i].events & EPOLLIN)) { handle_accept(epollfd, listenfd, pclient); } else { if (events[i].events & EPOLLIN) { do_read(epollfd, fd, pclient); } else { if (events[i].events & EPOLLOUT) { do_write(epollfd,fd,pclient); } } } } } static void do_epoll(int listenfd) { // int epollfd; struct epoll_event events[EPOLLEVENTS]; cli_t * pclient = (cli_t*)malloc(sizeof(cli_t)); set_socket_non_blocking(listenfd); int ret; // create one epoll fd int epollfd = epoll_create(FDSIZE); TRANSTATE ts=INIT; // add one listen fd into epoll pool add_event(epollfd,listenfd,EPOLLIN); for ( ; ; ) { // get the event ready ret = epoll_wait(epollfd,events,EPOLLEVENTS,EPOLL_TIMEOUT); if(ret <0) { perror("epoll_wait failed"); exit(1); } else if (ret == 0) { fprintf(stderr, "no socket ready for read within %d secs\n", EPOLL_TIMEOUT/1000); } else { handle_events(epollfd,listenfd,events,ret,pclient,&ts); } } close(epollfd); }

char message[BUF_SIZE]; int nread, nwrite; int times = 0; const char * key="key123\n"; printf("key len=%d\n", strlen(key)); #if 1 while ((nwrite = write(sock,key,strlen(key)+1))<0) { if(nwrite == -1){ if ((errno == EAGAIN) || (errno == EWOULDBLOCK)) { //sleep(1); printf("nwrite: try again!\n"); continue; } else { perror("read error"); exit(1); } } } #endif // nwrite = write(sock,key,strlen(key)+1); if (nwrite == 0) { fprintf(stderr, "nwrite: the client closed\n"); // exit(1); } else { printf("HW connected\n"); } //keep communicating with server int count = 0; while(1) { sprintf(message, "%d\n", count++); //Send count printf("[Send]: %s", message); if( (nwrite=write(sock, message, strlen(message)+1)) < 0) { perror("write failed"); exit(1); } else { if( nwrite == 0) { printf("nwwrite: no message written to svr\n"); } else { printf("writen done\n"); } } #if 1 //Receive a reply from the server while( (nread =read(sock, message, BUF_SIZE)) <= 0) { if(nread <0) { perror("read failed"); exit(1); } else { printf("nread: 0\n"); continue; } } printf("[Recv]: %s\n", message); #endif usleep(CLIENT_INTERVAL); } close(sock); exit(0); }

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