chat.h #ifndef _CHAT_H #define _CHAT_H #define LBUFFSIZE 128 #define CBUFFSIZE 331

Transcription

1 chat.h #ifndef _CHAT_H #define _CHAT_H #define LBUFFSIZE 128 #define CBUFFSIZE 331 #define INCRSLOT(V) { \ ++(V) ; \ if ((V) >= CBUFFSIZE) \ (V) = 0 ; \ enum Lstates {UNUSED, MESSAGE ; struct linebuff { enum Lstates status; / status of this linebuffer / int created ; / Time (seconds since 1970?) entry was made / int size ; / number of characters used in buffer / char buff[lbuffsize] ; / characters of the buffer / ; struct chatbuff { int nextslot ; / Index of nextslot to use / struct linebuff buff[cbuffsize] ; ; struct ptgenericarg { struct chatbuff G ; / Pointer to the global chatbuff / int sock ; / File Descriptor for socket / ; / prototypes for pthread_create / void InputFromUser(void ) ; void OutputToUser(void ) ; void InputRecept(void ) ; void OutputRecept(void ) ;

2 Main.c / Main routine... Starts the child threads / #include <errno.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <stdio.h> #include <pthread.h> #ifndef CHATINPORT #define CHATINPORT 7331 #ifndef CHATOUTPORT #define CHATOUTPORT 8331 int main(int argc, char argv[]) { int in_recept, out_recept ; struct sockaddr_in servaddr ; pthread_attr_t attribthread ; pthread_t inthread, outthread ; struct ptgenericarg inarg ; struct ptgenericarg outarg ; void newdata ; struct chatbuff G ; int i ; (void) pthread_attr_init(&attribthread) ; / Open the two sockets before creating the receptionist Pthreads This is the most likely thing to fail / if (((in_recept = socket(af_inet, SOCK_STREAM, 0)) < 0) ((out_recept = socket(af_inet, SOCK_STREAM, 0)) < 0)) { fputs("unable to create sockets\n", stderr) ; / Now this is unlikely to happen / servaddr.sin_family = AF_INET ; servaddr.sin_addr.s_addr = INADDR_ANY ; servaddr.sin_port = htons(chatinport) ; if (bind(in_recept, (struct sockaddr ) &servaddr, sizeof(struct sockaddr_in))) { fprintf(stderr, "Unable to bind to port %d\n", CHATINPORT) ; if (errno == EADDRINUSE) fputs("check if another server is still running\n\n" "If a server recently terminated, wait before restarting.\n", stderr) ; (void) listen(in_recept, SOMAXCONN) ; servaddr.sin_port = htons(chatoutport) ;

3 if (bind(out_recept, (struct sockaddr ) &servaddr, sizeof(struct sockaddr_in))) { fprintf(stderr, "Unable to bind to port %d\n", CHATOUTPORT) ; if (errno == EADDRINUSE) fputs("check if another server is still running\n\n" "If a server recently terminated, wait before restarting.\n", stderr) ; (void) listen(out_recept, SOMAXCONN) ; fprintf(stdout, "Reading connections -> %5d\n", CHATINPORT) ; fprintf(stdout, "Writing connections -> %5d\n", CHATOUTPORT) ; / Initialize chat buffer / if ((G = malloc(sizeof(struct chatbuff))) == NULL) { G->nextSlot = 0 ; for (i=0; i<cbuffsize; ++i) { G->buff[i].status = UNUSED ; G->buff[i].size = 0 ; inarg = (struct ptgenericarg )newdata ; inarg->sock = in_recept ; inarg->g = G ; if (pthread_create(&inthread, &attribthread, InputRecept, newdata)) { perror("pthread_create InputRecept") ; outarg = (struct ptgenericarg )newdata ; outarg->sock = out_recept ; outarg->g = G ; if (pthread_create(&outthread, &attribthread, OutputRecept, newdata)) { perror("pthread_create OutputRecept") ; pthread_join(inthread, (void )NULL) ; pthread_join(outthread, (void )NULL) ;

4 InputRecept.c / Input Receptionist This is the thread routine for starting new output threads / #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <pthread.h> void InputRecept(void ptargs) { struct chatbuff G ; pthread_attr_t attribthread ; (void) pthread_attr_init(&attribthread) ; (void) pthread_attr_setdetachstate(&attribthread, PTHREAD_CREATE_DETACHED) ; mysock = ((struct ptgenericarg )ptargs) -> sock ; G = ((struct ptgenericarg )ptargs) -> G ; while (1) { void newdata ; int clntsize ; int newclient ; struct sockaddr_in clntaddr; pthread_t newthread ; struct ptgenericarg newthreadargs ; char chattername ; clntsize = sizeof(struct sockaddr_in) ; newclient = accept(mysock, (struct sockaddr )&clntaddr, &clntsize) ; if (newclient<0) { perror("accept") ; / Shutting down the write side causes telnet to terminate / / (void) shutdown(newclient, SHUT_WR) ; / newthreadargs = (struct ptgenericarg )newdata ; newthreadargs->g = G ; newthreadargs->sock = newclient ; if (pthread_create(&newthread, &attribthread, InputFromUser, newdata)) { perror("pthread_create") ; return ((void )NULL) ;

5 OutputRecept.c / Output Receptionist This is the thread routine for starting new output threads / #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <pthread.h> void OutputRecept(void ptargs) { struct chatbuff G ; pthread_attr_t attribthread ; (void) pthread_attr_init(&attribthread) ; (void) pthread_attr_setdetachstate(&attribthread, PTHREAD_CREATE_DETACHED) ; mysock = ((struct ptgenericarg )ptargs) -> sock ; G = ((struct ptgenericarg )ptargs) -> G ; while (1) { void newdata ; int clntsize ; int newclient ; struct sockaddr_in clntaddr; pthread_t newthread ; struct ptgenericarg newthreadargs ; clntsize = sizeof(struct sockaddr_in) ; newclient = accept(mysock, (struct sockaddr )&clntaddr, &clntsize) ; if (newclient<0) { perror("accept") ; (void) shutdown(newclient, SHUT_RD) ; newthreadargs = (struct ptgenericarg )newdata ; newthreadargs->g = G ; newthreadargs->sock = newclient ; if (pthread_create(&newthread, &attribthread, OutputToUser, newdata)) { perror("pthread_create") ; return ((void )NULL) ;

6 InputFromUser.c / This is the thread routine for taking input from the user and placing it into the chat buffer. / #include <stdio.h> #include <strings.h> void AddToChatBuffer(struct chatbuff G, struct linebuff pmylinebuff){ int myslot ; myslot = G->nextSlot ; INCRSLOT(&G->nextSlot) ; bcopy((void )pmylinebuff,(void )&G->buff[mySlot],sizeof(struct linebuff)); void InputFromUser(void ptargs) { struct chatbuff volatile G ; struct linebuff mylinebuff ; struct timeval present ; int userinputsize ; int stillconnected ; FILE sockin ; mysock = ((struct ptgenericarg )ptargs) -> sock ; G = ((struct ptgenericarg )ptargs) -> G ; if ((sockin = fdopen(mysock, "r")) == (FILE )NULL) { perror("fdopen") ; pthread_exit((void )NULL) ; stillconnected = 1 ; mylinebuff.status = MESSAGE ; while (stillconnected) { int nextc = 0 ; mylinebuff.size = 0 ; while (stillconnected && mylinebuff.size<cbuffsize-1 && nextc!= '\n') { if ((nextc=fgetc(sockin))!= EOF) { mylinebuff.buff[mylinebuff.size] = nextc ; ++mylinebuff.size ; else stillconnected = 0 ; if (stillconnected) { gettimeofday(&present, (struct timezone )NULL) ; mylinebuff.created = present.tv_sec ; #ifdef DEBUG mylinebuff.buff[mylinebuff.size] = '\0'; printf("new line %s", mylinebuff.size, mylinebuff.buff) ; AddToChatBuffer(G, &mylinebuff) ; return ((void )NULL) ;

7 OutputToUser.c / This is the thread routine for removing items from the chat buffer and sending them to the user. / #include <strings.h> #include <stdio.h> void OutputToUser(void ptargs) { struct chatbuff volatile G ; struct linebuff mylinebuff ; int mynextslot ; int stillconnected ; FILE sockout ; mysock = ((struct ptgenericarg )ptargs) -> sock ; G = ((struct ptgenericarg )ptargs) -> G ; stillconnected = 1 ; mynextslot = G->nextSlot ; if ((sockout = fdopen(mysock, "w")) == (FILE )NULL) { perror("fdopen") ; pthread_exit((void )NULL) ; while (stillconnected) { int i ; while (mynextslot == G->nextSlot) { sleep(1) ; #ifdef DEBUG printf("nextslot = %d, G->nextSlot = %d\n", mynextslot, G->nextSlot) ; / spinning / bcopy((void )&G->buff[myNextSlot], (void )&mylinebuff, sizeof(struct linebuff)); for (i=0; i<mylinebuff.size && stillconnected; ++i) if (fputc((int) mylinebuff.buff[i], sockout) == EOF) stillconnected = 0 ; if (stillconnected && (fflush(sockout) == EOF)) stillconnected = 0 ; INCRSLOT(&myNextSlot) ; return ((void )NULL) ;