X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=afs.c;h=bc42026e460ac7ba5f38f992ae17e1f18a3c5ce9;hp=d41a518d791f9908b0230beda99849f0a8f4c3e9;hb=63b57e3e60923cea4e3e1808e3133789db2dc83a;hpb=19c44d502e169d4801449861e7ef0252e3b1dc5b diff --git a/afs.c b/afs.c index d41a518d..bc42026e 100644 --- a/afs.c +++ b/afs.c @@ -145,11 +145,20 @@ struct callback_result { * * \param f The function to be called. * \param query Pointer to arbitrary data for the callback. - * \param result Callback result will be stored here. + * \param result_handler Called for each shm area sent by the callback. + * \param private_result_data Passed verbatim to \a result_handler. * - * This function creates a shared memory area, copies the buffer pointed to by - * \a query to that area and notifies the afs process that \a f should be - * called ASAP. + * This function creates a socket for communication with the afs process and a + * shared memory area (sma) to which the buffer pointed to by \a query is + * copied. It then notifies the afs process that the callback function \a f + * should be executed by sending the shared memory identifier (shmid) to the + * socket. + + * If the callback produces a result, it sends any number of shared memory + * identifiers back via the socket. For each such identifier received, \a + * result_handler is called. The contents of the sma identified by the received + * shmid are passed to that function as an osl object. The private_result_data + * pointer is passed as the second argument to \a result_handler. * * \return Negative, on errors, the return value of the callback function * otherwise. @@ -245,7 +254,8 @@ out: * \param argc Argument count. * \param argv Standard argument vector. * \param f The callback function. - * \param result The result of the query is stored here. + * \param result_handler See \ref send_callback_request. + * \param private_result_data See \ref send_callback_request. * * Some commands have a couple of options that are parsed in child context for * syntactic correctness and are stored in a special options structure for that @@ -287,7 +297,8 @@ int send_option_arg_callback_request(struct osl_object *options, * \param argc The same meaning as in send_option_arg_callback_request(). * \param argv The same meaning as in send_option_arg_callback_request(). * \param f The same meaning as in send_option_arg_callback_request(). - * \param result The same meaning as in send_option_arg_callback_request(). + * \param result_handler See \ref send_callback_request. + * \param private_result_data See \ref send_callback_request. * * This is similar to send_option_arg_callback_request(), but no options buffer * is passed to the parent process. @@ -407,13 +418,15 @@ static int fd2buf(int fd, unsigned max_size, struct osl_object *obj) * \param arg_obj Pointer to the arguments to \a f. * \param f The callback function. * \param max_len Don't read more than that many bytes from stdin. - * \param result The result of the query is stored here. + * \param result_handler See \ref send_callback_request. + * \param private_result_data See \ref send_callback_request. * * This function is used by commands that wish to let para_server store * arbitrary data specified by the user (for instance the add_blob family of * commands). First, at most \a max_len bytes are read from \a fd, the result * is concatenated with the buffer given by \a arg_obj, and the combined buffer - * is made available to the parent process via shared memory. + * is made available to the afs process via the callback method. See \ref + * send_callback_request for details. * * \return Negative on errors, the return value of the underlying call to * send_callback_request() otherwise. @@ -486,7 +499,7 @@ static int pass_afd(int fd, char *buf, size_t size) * * \sa open_and_update_audio_file(). */ -int open_next_audio_file(void) +static int open_next_audio_file(void) { struct osl_row *aft_row; struct audio_file_data afd; @@ -573,41 +586,58 @@ static int activate_mood_or_playlist(char *arg, int *num_admissible) return 1; } -static int com_select_callback(const struct osl_object *query, - struct osl_object *result) +static void com_select_callback(int fd, const struct osl_object *query) { - struct para_buffer pb = {.buf = NULL}; + struct para_buffer pb = { + .max_size = SHMMAX, + .private_data = &fd, + .max_size_handler = pass_buffer_as_shm + }; char *arg = query->data; - int num_admissible, ret; + int num_admissible, ret, ret2; ret = clear_score_table(); - if (ret < 0) - return ret; + if (ret < 0) { + ret2 = para_printf(&pb, "%s\n", para_strerror(-ret)); + goto out; + } if (current_play_mode == PLAY_MODE_MOOD) close_current_mood(); else playlist_close(); ret = activate_mood_or_playlist(arg, &num_admissible); if (ret < 0) { - para_printf(&pb, "%s\n", para_strerror(-ret)); - para_printf(&pb, "switching back to %s\n", current_mop? + ret2 = para_printf(&pb, "%s\nswitching back to %s\n", + para_strerror(-ret), current_mop? current_mop : "dummy"); ret = activate_mood_or_playlist(current_mop, &num_admissible); if (ret < 0) { - para_printf(&pb, "failed, switching to dummy\n"); + if (ret2 >= 0) + ret2 = para_printf(&pb, "failed, switching to dummy\n"); activate_mood_or_playlist(NULL, &num_admissible); } - } - para_printf(&pb, "activated %s (%d admissible files)\n", current_mop? - current_mop : "dummy mood", num_admissible); - result->data = pb.buf; - result->size = pb.offset; - return 1; + } else + ret2 = para_printf(&pb, "activated %s (%d admissible files)\n", current_mop? + current_mop : "dummy mood", num_admissible); +out: + if (ret2 >= 0 && pb.offset) + pass_buffer_as_shm(pb.buf, pb.offset, &fd); + free(pb.buf); } -int send_result(struct osl_object *result, void *private_result_data) +/** + * Result handler for sending data to the para_client process. + * + * \param result The data to be sent. + * \param fd_ptr Pointer to the file descriptor. + * + * \return The return value of the underlying call to send_bin_buffer(). + * + * \sa \ref callback_result_handler. + */ +int send_result(struct osl_object *result, void *fd_ptr) { - int fd = *(int *)private_result_data; + int fd = *(int *)fd_ptr; if (!result->size) return 1; return send_bin_buffer(fd, result->data, result->size); @@ -717,59 +747,56 @@ static int open_afs_tables(void) return ret; } -static void unregister_tasks(void) -{ - unregister_task(&command_task_struct.task); - unregister_task(&signal_task_struct.task); -} - static void signal_pre_select(struct sched *s, struct task *t) { - struct signal_task *st = t->private_data; - t->ret = 1; + struct signal_task *st = container_of(t, struct signal_task, task); para_fd_set(st->fd, &s->rfds, &s->max_fileno); } static void signal_post_select(struct sched *s, struct task *t) { - struct signal_task *st = t->private_data; - t->ret = -E_AFS_PARENT_DIED; - if (getppid() == 1) - goto err; - t->ret = 1; + struct signal_task *st = container_of(t, struct signal_task, task); + if (getppid() == 1) { + PARA_EMERG_LOG("para_server died\n"); + goto shutdown; + } if (!FD_ISSET(st->fd, &s->rfds)) return; st->signum = para_next_signal(); - t->ret = 1; - if (st->signum == SIGUSR1) - return; /* ignore SIGUSR1 */ if (st->signum == SIGHUP) { close_afs_tables(); - t->ret = open_afs_tables(); - if (t->ret < 0) - goto err; + t->error = open_afs_tables(); + if (t->error < 0) + return; init_admissible_files(current_mop); return; } - t->ret = -E_AFS_SIGNAL; -err: - PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret)); - unregister_tasks(); + PARA_EMERG_LOG("terminating on signal %d\n", st->signum); +shutdown: + sched_shutdown(); + t->error = -E_AFS_SIGNAL; } static void register_signal_task(void) { struct signal_task *st = &signal_task_struct; + + if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) { + PARA_EMERG_LOG("failed to ignore SIGPIPE\n"); + exit(EXIT_FAILURE); + } + if (signal(SIGUSR1, SIG_IGN) == SIG_ERR) { + PARA_EMERG_LOG("failed to ignore SIGUSR1\n"); + exit(EXIT_FAILURE); + } st->fd = para_signal_init(); PARA_INFO_LOG("signal pipe: fd %d\n", st->fd); para_install_sighandler(SIGINT); para_install_sighandler(SIGTERM); - para_install_sighandler(SIGPIPE); para_install_sighandler(SIGHUP); st->task.pre_select = signal_pre_select; st->task.post_select = signal_post_select; - st->task.private_data = st; sprintf(st->task.status, "signal task"); register_task(&st->task); } @@ -788,25 +815,42 @@ struct afs_client { static void command_pre_select(struct sched *s, struct task *t) { - struct command_task *ct = t->private_data; + struct command_task *ct = container_of(t, struct command_task, task); struct afs_client *client; para_fd_set(server_socket, &s->rfds, &s->max_fileno); para_fd_set(ct->fd, &s->rfds, &s->max_fileno); list_for_each_entry(client, &afs_client_list, node) para_fd_set(client->fd, &s->rfds, &s->max_fileno); - t->ret = 1; } -int pass_object_as_shm(int fd, struct osl_object *obj) +/** + * Send data as shared memory to a file descriptor. + * + * \param buf The buffer holding the data to be sent. + * \param size The size of \a buf. + * \param fd_ptr A pointer to the file descriptor. + * + * This function is used as the \a max_size handler in a \ref para_buffer + * structure. If used this way, it is called by \ref para_printf() whenever + * the buffer passed to para_printf() is about to exceed its maximal size. + * + * This function creates a shared memory area large enough to hold + * the content given by \a buf and \a size and sends the identifier + * of this area to the file descriptor given by \a fd_ptr. + * + * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors, + * and positive on success. + */ +int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr) { - int ret, shmid; + int ret, shmid, fd = *(int *)fd_ptr; void *shm; struct callback_result *cr; - if (!obj->data || !obj->size) + if (!buf || !size) return 0; - ret = shm_new(obj->size + sizeof(struct callback_result)); + ret = shm_new(size + sizeof(struct callback_result)); if (ret < 0) return ret; shmid = ret; @@ -814,8 +858,8 @@ int pass_object_as_shm(int fd, struct osl_object *obj) if (ret < 0) goto err; cr = shm; - cr->result_size = obj->size; - memcpy(shm + sizeof(*cr), obj->data, obj->size); + cr->result_size = size; + memcpy(shm + sizeof(*cr), buf, size); ret = shm_detach(shm); if (ret < 0) goto err; @@ -833,51 +877,41 @@ err: * On success: If query produced a result, the result_shmid is written to fd. * Otherwise, zero is written. */ -static void call_callback(int fd, int query_shmid) +static int call_callback(int fd, int query_shmid) { void *query_shm; struct callback_query *cq; - struct osl_object query, result = {.data = NULL}; + struct osl_object query; int ret; ret = shm_attach(query_shmid, ATTACH_RW, &query_shm); if (ret < 0) - goto out; + return ret; cq = query_shm; query.data = (char *)query_shm + sizeof(*cq); query.size = cq->query_size; - ret = cq->handler(&query, &result); - if (ret < 0) - goto out; - ret = pass_object_as_shm(fd, &result); -out: - free(result.data); - if (ret < 0) - PARA_ERROR_LOG("%s\n", para_strerror(-ret)); + cq->handler(fd, &query); + return 1; } -static void execute_server_command(void) +static int execute_server_command(void) { char buf[8]; int ret = recv_bin_buffer(server_socket, buf, sizeof(buf) - 1); if (ret <= 0) { - if (ret < 0) - PARA_ERROR_LOG("%s\n", para_strerror(-ret)); - return; + if (!ret) + ret = -ERRNO_TO_PARA_ERROR(ECONNRESET); + goto err; } buf[ret] = '\0'; PARA_DEBUG_LOG("received: %s\n", buf); - if (!strcmp(buf, "new")) { - ret = open_next_audio_file(); - if (ret < 0) { - PARA_EMERG_LOG("%s\n", para_strerror(-ret)); - unregister_tasks(); - } - return; - } - PARA_ERROR_LOG("unknown command\n"); - + ret = -E_BAD_CMD; + if (strcmp(buf, "new")) + goto err; + ret = open_next_audio_file(); +err: + return ret; } static void execute_afs_command(int fd, uint32_t expected_cookie) @@ -887,10 +921,8 @@ static void execute_afs_command(int fd, uint32_t expected_cookie) char buf[sizeof(cookie) + sizeof(query_shmid)]; int ret = recv_bin_buffer(fd, buf, sizeof(buf)); - if (ret < 0) { - PARA_NOTICE_LOG("%s\n", para_strerror(-ret)); - return; - } + if (ret < 0) + goto err; if (ret != sizeof(buf)) { PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n", ret, (long unsigned) sizeof(buf)); @@ -908,7 +940,11 @@ static void execute_afs_command(int fd, uint32_t expected_cookie) query_shmid); return; } - call_callback(fd, query_shmid); + ret = call_callback(fd, query_shmid); + if (ret >= 0) + return; +err: + PARA_NOTICE_LOG("%s\n", para_strerror(-ret)); } /** Shutdown connection if query has not arrived until this many seconds. */ @@ -916,12 +952,19 @@ static void execute_afs_command(int fd, uint32_t expected_cookie) static void command_post_select(struct sched *s, struct task *t) { - struct command_task *ct = t->private_data; + struct command_task *ct = container_of(t, struct command_task, task); struct sockaddr_un unix_addr; struct afs_client *client, *tmp; - int fd; - if (FD_ISSET(server_socket, &s->rfds)) - execute_server_command(); + int fd, ret; + + if (FD_ISSET(server_socket, &s->rfds)) { + ret = execute_server_command(); + if (ret < 0) { + PARA_EMERG_LOG("%s\n", para_strerror(-ret)); + sched_shutdown(); + return; + } + } /* Check the list of connected clients. */ list_for_each_entry_safe(client, tmp, &afs_client_list, node) { @@ -940,25 +983,23 @@ static void command_post_select(struct sched *s, struct task *t) } /* Accept connections on the local socket. */ if (!FD_ISSET(ct->fd, &s->rfds)) - goto out; - t->ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr)); - if (t->ret < 0) { - PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret)); - goto out; + return; + ret = para_accept(ct->fd, &unix_addr, sizeof(unix_addr)); + if (ret < 0) { + PARA_NOTICE_LOG("%s\n", para_strerror(-ret)); + return; } - fd = t->ret; - t->ret = mark_fd_nonblocking(fd); - if (t->ret < 0) { - PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret)); + fd = ret; + ret = mark_fd_nonblocking(fd); + if (ret < 0) { + PARA_NOTICE_LOG("%s\n", para_strerror(-ret)); close(fd); - goto out; + return; } client = para_malloc(sizeof(*client)); client->fd = fd; client->connect_time = *now; para_list_add(&client->node, &afs_client_list); -out: - t->ret = 1; } static void register_command_task(uint32_t cookie) @@ -969,17 +1010,10 @@ static void register_command_task(uint32_t cookie) ct->task.pre_select = command_pre_select; ct->task.post_select = command_post_select; - ct->task.private_data = ct; sprintf(ct->task.status, "command task"); register_task(&ct->task); } -static void register_tasks(uint32_t cookie) -{ - register_signal_task(); - register_command_task(cookie); -} - /** * Initialize the audio file selector process. * @@ -991,37 +1025,37 @@ __noreturn void afs_init(uint32_t cookie, int socket_fd) struct sched s; int i, ret; + register_signal_task(); INIT_LIST_HEAD(&afs_client_list); for (i = 0; i < NUM_AFS_TABLES; i++) afs_tables[i].init(&afs_tables[i]); ret = open_afs_tables(); - - if (ret < 0) { - PARA_EMERG_LOG("%s\n", para_strerror(-ret)); - exit(EXIT_FAILURE); - } + if (ret < 0) + goto out; server_socket = socket_fd; ret = mark_fd_nonblocking(server_socket); if (ret < 0) - exit(EXIT_FAILURE); + goto out_close; PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n", server_socket, (unsigned) cookie); init_admissible_files(conf.afs_initial_mode_arg); - register_tasks(cookie); + register_command_task(cookie); s.default_timeout.tv_sec = 0; s.default_timeout.tv_usec = 999 * 1000; ret = schedule(&s); +out_close: + close_afs_tables(); +out: if (ret < 0) PARA_EMERG_LOG("%s\n", para_strerror(-ret)); - close_afs_tables(); exit(EXIT_FAILURE); } -static int create_tables_callback(const struct osl_object *query, - __a_unused struct osl_object *result) +static void create_tables_callback(int fd, const struct osl_object *query) { uint32_t table_mask = *(uint32_t *)query->data; int i, ret; + char *buf; close_afs_tables(); for (i = 0; i < NUM_AFS_TABLES; i++) { @@ -1033,10 +1067,16 @@ static int create_tables_callback(const struct osl_object *query, continue; ret = t->create(database_dir); if (ret < 0) - return ret; + goto out; } ret = open_afs_tables(); - return ret < 0? ret: 0; +out: + if (ret >= 0) + buf = make_message("successfully created afs table(s)\n"); + else + buf = make_message("%s\n", para_strerror(-ret)); + pass_buffer_as_shm(buf, strlen(buf), &fd); + free(buf); } int com_init(int fd, int argc, char * const * const argv) @@ -1066,8 +1106,8 @@ int com_init(int fd, int argc, char * const * const argv) } ret = send_callback_request(create_tables_callback, &query, NULL, NULL); if (ret < 0) - return ret; - return send_va_buffer(fd, "successfully created afs table(s)\n"); + return send_va_buffer(fd, "%s\n", para_strerror(-ret)); + return ret; } /**