2 * This file is part of the libsigrok project.
4 * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
25 #include "libsigrok.h"
26 #include "libsigrok-internal.h"
28 #define LOG_PREFIX "session"
33 * Creating, using, or destroying libsigrok sessions.
37 * @defgroup grp_session Session handling
39 * Creating, using, or destroying libsigrok sessions.
46 sr_receive_data_callback_t cb;
49 /* This is used to keep track of the object (fd, pollfd or channel) which is
50 * being polled and will be used to match the source when removing it again.
55 struct datafeed_callback {
56 sr_datafeed_callback_t cb;
60 /* There can only be one session at a time. */
61 /* 'session' is not static, it's used elsewhere (via 'extern'). */
62 struct sr_session *session;
65 * Create a new session.
67 * @todo Should it use the file-global "session" variable or take an argument?
68 * The same question applies to all the other session functions.
71 * @retval other A pointer to the newly allocated session.
73 SR_API struct sr_session *sr_session_new(void)
75 if (!(session = g_try_malloc0(sizeof(struct sr_session)))) {
76 sr_err("Session malloc failed.");
80 session->source_timeout = -1;
81 session->running = FALSE;
82 session->abort_session = FALSE;
83 g_mutex_init(&session->stop_mutex);
89 * Destroy the current session.
90 * This frees up all memory used by the session.
92 * @retval SR_OK Success.
93 * @retval SR_ERR_BUG No session exists.
95 SR_API int sr_session_destroy(void)
98 sr_err("%s: session was NULL", __func__);
102 sr_session_dev_remove_all();
104 /* TODO: Error checks needed? */
106 g_mutex_clear(&session->stop_mutex);
115 * Remove all the devices from the current session.
117 * The session itself (i.e., the struct sr_session) is not free'd and still
118 * exists after this function returns.
120 * @retval SR_OK Success.
121 * @retval SR_ERR_BUG No session exists.
123 SR_API int sr_session_dev_remove_all(void)
126 sr_err("%s: session was NULL", __func__);
130 g_slist_free(session->devs);
131 session->devs = NULL;
137 * Add a device instance to the current session.
139 * @param sdi The device instance to add to the current session. Must not
140 * be NULL. Also, sdi->driver and sdi->driver->dev_open must
143 * @retval SR_OK Success.
144 * @retval SR_ERR_ARG Invalid argument.
145 * @retval SR_ERR_BUG No session exists.
147 SR_API int sr_session_dev_add(const struct sr_dev_inst *sdi)
152 sr_err("%s: sdi was NULL", __func__);
157 sr_err("%s: session was NULL", __func__);
161 /* If sdi->driver is NULL, this is a virtual device. */
163 sr_dbg("%s: sdi->driver was NULL, this seems to be "
164 "a virtual device; continuing", __func__);
165 /* Just add the device, don't run dev_open(). */
166 session->devs = g_slist_append(session->devs, (gpointer)sdi);
170 /* sdi->driver is non-NULL (i.e. we have a real device). */
171 if (!sdi->driver->dev_open) {
172 sr_err("%s: sdi->driver->dev_open was NULL", __func__);
176 session->devs = g_slist_append(session->devs, (gpointer)sdi);
178 if (session->running) {
179 /* Adding a device to a running session. Commit settings
180 * and start acquisition on that device now. */
181 if ((ret = sr_config_commit(sdi)) != SR_OK) {
182 sr_err("Failed to commit device settings before "
183 "starting acquisition in running session (%s)",
187 if ((ret = sdi->driver->dev_acquisition_start(sdi,
188 (void *)sdi)) != SR_OK) {
189 sr_err("Failed to start acquisition of device in "
190 "running session (%s)", sr_strerror(ret));
199 * List all device instances attached to the current session.
201 * @param devlist A pointer where the device instance list will be
202 * stored on return. If no devices are in the session,
203 * this will be NULL. Each element in the list points
204 * to a struct sr_dev_inst *.
205 * The list must be freed by the caller, but not the
206 * elements pointed to.
208 * @retval SR_OK Success.
209 * @retval SR_ERR Invalid argument.
211 SR_API int sr_session_dev_list(GSList **devlist)
219 *devlist = g_slist_copy(session->devs);
225 * Remove all datafeed callbacks in the current session.
227 * @retval SR_OK Success.
228 * @retval SR_ERR_BUG No session exists.
230 SR_API int sr_session_datafeed_callback_remove_all(void)
233 sr_err("%s: session was NULL", __func__);
237 g_slist_free_full(session->datafeed_callbacks, g_free);
238 session->datafeed_callbacks = NULL;
244 * Add a datafeed callback to the current session.
246 * @param cb Function to call when a chunk of data is received.
248 * @param cb_data Opaque pointer passed in by the caller.
250 * @retval SR_OK Success.
251 * @retval SR_ERR_BUG No session exists.
253 SR_API int sr_session_datafeed_callback_add(sr_datafeed_callback_t cb, void *cb_data)
255 struct datafeed_callback *cb_struct;
258 sr_err("%s: session was NULL", __func__);
263 sr_err("%s: cb was NULL", __func__);
267 if (!(cb_struct = g_try_malloc0(sizeof(struct datafeed_callback))))
268 return SR_ERR_MALLOC;
271 cb_struct->cb_data = cb_data;
273 session->datafeed_callbacks =
274 g_slist_append(session->datafeed_callbacks, cb_struct);
280 * Call every device in the session's callback.
282 * For sessions not driven by select loops such as sr_session_run(),
283 * but driven by another scheduler, this can be used to poll the devices
284 * from within that scheduler.
286 * @param block If TRUE, this call will wait for any of the session's
287 * sources to fire an event on the file descriptors, or
288 * any of their timeouts to activate. In other words, this
289 * can be used as a select loop.
290 * If FALSE, all sources have their callback run, regardless
291 * of file descriptor or timeout status.
293 * @retval SR_OK Success.
294 * @retval SR_ERR Error occured.
296 static int sr_session_iteration(gboolean block)
301 ret = g_poll(session->pollfds, session->num_sources,
302 block ? session->source_timeout : 0);
303 for (i = 0; i < session->num_sources; i++) {
304 if (session->pollfds[i].revents > 0 || (ret == 0
305 && session->source_timeout == session->sources[i].timeout)) {
307 * Invoke the source's callback on an event,
308 * or if the poll timed out and this source
309 * asked for that timeout.
311 if (!session->sources[i].cb(session->pollfds[i].fd,
312 session->pollfds[i].revents,
313 session->sources[i].cb_data))
314 sr_session_source_remove(session->sources[i].poll_object);
317 * We want to take as little time as possible to stop
318 * the session if we have been told to do so. Therefore,
319 * we check the flag after processing every source, not
320 * just once per main event loop.
322 g_mutex_lock(&session->stop_mutex);
323 if (session->abort_session) {
324 sr_session_stop_sync();
325 /* But once is enough. */
326 session->abort_session = FALSE;
328 g_mutex_unlock(&session->stop_mutex);
337 * There can only be one session at a time.
339 * @retval SR_OK Success.
340 * @retval SR_ERR Error occured.
342 SR_API int sr_session_start(void)
344 struct sr_dev_inst *sdi;
349 sr_err("%s: session was NULL; a session must be "
350 "created before starting it.", __func__);
354 if (!session->devs) {
355 sr_err("%s: session->devs was NULL; a session "
356 "cannot be started without devices.", __func__);
360 sr_info("Starting.");
363 for (l = session->devs; l; l = l->next) {
365 if ((ret = sr_config_commit(sdi)) != SR_OK) {
366 sr_err("Failed to commit device settings before "
367 "starting acquisition (%s)", sr_strerror(ret));
370 if ((ret = sdi->driver->dev_acquisition_start(sdi, sdi)) != SR_OK) {
371 sr_err("%s: could not start an acquisition "
372 "(%s)", __func__, sr_strerror(ret));
377 /* TODO: What if there are multiple devices? Which return code? */
385 * @retval SR_OK Success.
386 * @retval SR_ERR_BUG Error occured.
388 SR_API int sr_session_run(void)
391 sr_err("%s: session was NULL; a session must be "
392 "created first, before running it.", __func__);
396 if (!session->devs) {
397 /* TODO: Actually the case? */
398 sr_err("%s: session->devs was NULL; a session "
399 "cannot be run without devices.", __func__);
402 session->running = TRUE;
406 /* Do we have real sources? */
407 if (session->num_sources == 1 && session->pollfds[0].fd == -1) {
408 /* Dummy source, freewheel over it. */
409 while (session->num_sources)
410 session->sources[0].cb(-1, 0, session->sources[0].cb_data);
412 /* Real sources, use g_poll() main loop. */
413 while (session->num_sources)
414 sr_session_iteration(TRUE);
421 * Stop the current session.
423 * The current session is stopped immediately, with all acquisition sessions
424 * being stopped and hardware drivers cleaned up.
426 * This must be called from within the session thread, to prevent freeing
427 * resources that the session thread will try to use.
429 * @retval SR_OK Success.
430 * @retval SR_ERR_BUG No session exists.
434 SR_PRIV int sr_session_stop_sync(void)
436 struct sr_dev_inst *sdi;
440 sr_err("%s: session was NULL", __func__);
444 sr_info("Stopping.");
446 for (l = session->devs; l; l = l->next) {
449 if (sdi->driver->dev_acquisition_stop)
450 sdi->driver->dev_acquisition_stop(sdi, sdi);
453 session->running = FALSE;
459 * Stop the current session.
461 * The current session is stopped immediately, with all acquisition sessions
462 * being stopped and hardware drivers cleaned up.
464 * If the session is run in a separate thread, this function will not block
465 * until the session is finished executing. It is the caller's responsibility
466 * to wait for the session thread to return before assuming that the session is
467 * completely decommissioned.
469 * @retval SR_OK Success.
470 * @retval SR_ERR_BUG No session exists.
472 SR_API int sr_session_stop(void)
475 sr_err("%s: session was NULL", __func__);
479 g_mutex_lock(&session->stop_mutex);
480 session->abort_session = TRUE;
481 g_mutex_unlock(&session->stop_mutex);
489 * @param packet The packet to show debugging information for.
491 static void datafeed_dump(const struct sr_datafeed_packet *packet)
493 const struct sr_datafeed_logic *logic;
494 const struct sr_datafeed_analog *analog;
496 switch (packet->type) {
498 sr_dbg("bus: Received SR_DF_HEADER packet.");
501 sr_dbg("bus: Received SR_DF_TRIGGER packet.");
504 sr_dbg("bus: Received SR_DF_META packet.");
507 logic = packet->payload;
508 sr_dbg("bus: Received SR_DF_LOGIC packet (%" PRIu64 " bytes).",
512 analog = packet->payload;
513 sr_dbg("bus: Received SR_DF_ANALOG packet (%d samples).",
514 analog->num_samples);
517 sr_dbg("bus: Received SR_DF_END packet.");
519 case SR_DF_FRAME_BEGIN:
520 sr_dbg("bus: Received SR_DF_FRAME_BEGIN packet.");
522 case SR_DF_FRAME_END:
523 sr_dbg("bus: Received SR_DF_FRAME_END packet.");
526 sr_dbg("bus: Received unknown packet type: %d.", packet->type);
532 * Send a packet to whatever is listening on the datafeed bus.
534 * Hardware drivers use this to send a data packet to the frontend.
537 * @param packet The datafeed packet to send to the session bus.
539 * @retval SR_OK Success.
540 * @retval SR_ERR_ARG Invalid argument.
544 SR_PRIV int sr_session_send(const struct sr_dev_inst *sdi,
545 const struct sr_datafeed_packet *packet)
548 struct datafeed_callback *cb_struct;
551 sr_err("%s: sdi was NULL", __func__);
556 sr_err("%s: packet was NULL", __func__);
560 for (l = session->datafeed_callbacks; l; l = l->next) {
561 if (sr_log_loglevel_get() >= SR_LOG_DBG)
562 datafeed_dump(packet);
564 cb_struct->cb(sdi, packet, cb_struct->cb_data);
571 * Add an event source for a file descriptor.
573 * @param pollfd The GPollFD.
574 * @param[in] timeout Max time to wait before the callback is called,
576 * @param cb Callback function to add. Must not be NULL.
577 * @param cb_data Data for the callback function. Can be NULL.
578 * @param poll_object TODO.
580 * @retval SR_OK Success.
581 * @retval SR_ERR_ARG Invalid argument.
582 * @retval SR_ERR_MALLOC Memory allocation error.
584 static int _sr_session_source_add(GPollFD *pollfd, int timeout,
585 sr_receive_data_callback_t cb, void *cb_data, gintptr poll_object)
587 struct source *new_sources, *s;
588 GPollFD *new_pollfds;
591 sr_err("%s: cb was NULL", __func__);
595 /* Note: cb_data can be NULL, that's not a bug. */
597 new_pollfds = g_try_realloc(session->pollfds,
598 sizeof(GPollFD) * (session->num_sources + 1));
600 sr_err("%s: new_pollfds malloc failed", __func__);
601 return SR_ERR_MALLOC;
604 new_sources = g_try_realloc(session->sources, sizeof(struct source) *
605 (session->num_sources + 1));
607 sr_err("%s: new_sources malloc failed", __func__);
608 return SR_ERR_MALLOC;
611 new_pollfds[session->num_sources] = *pollfd;
612 s = &new_sources[session->num_sources++];
613 s->timeout = timeout;
615 s->cb_data = cb_data;
616 s->poll_object = poll_object;
617 session->pollfds = new_pollfds;
618 session->sources = new_sources;
620 if (timeout != session->source_timeout && timeout > 0
621 && (session->source_timeout == -1 || timeout < session->source_timeout))
622 session->source_timeout = timeout;
628 * Add an event source for a file descriptor.
630 * @param fd The file descriptor.
631 * @param events Events to check for.
632 * @param timeout Max time to wait before the callback is called, ignored if 0.
633 * @param cb Callback function to add. Must not be NULL.
634 * @param cb_data Data for the callback function. Can be NULL.
636 * @retval SR_OK Success.
637 * @retval SR_ERR_ARG Invalid argument.
638 * @retval SR_ERR_MALLOC Memory allocation error.
640 SR_API int sr_session_source_add(int fd, int events, int timeout,
641 sr_receive_data_callback_t cb, void *cb_data)
648 return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)fd);
652 * Add an event source for a GPollFD.
654 * @param pollfd The GPollFD.
655 * @param timeout Max time to wait before the callback is called, ignored if 0.
656 * @param cb Callback function to add. Must not be NULL.
657 * @param cb_data Data for the callback function. Can be NULL.
659 * @retval SR_OK Success.
660 * @retval SR_ERR_ARG Invalid argument.
661 * @retval SR_ERR_MALLOC Memory allocation error.
663 SR_API int sr_session_source_add_pollfd(GPollFD *pollfd, int timeout,
664 sr_receive_data_callback_t cb, void *cb_data)
666 return _sr_session_source_add(pollfd, timeout, cb,
667 cb_data, (gintptr)pollfd);
671 * Add an event source for a GIOChannel.
673 * @param channel The GIOChannel.
674 * @param events Events to poll on.
675 * @param timeout Max time to wait before the callback is called, ignored if 0.
676 * @param cb Callback function to add. Must not be NULL.
677 * @param cb_data Data for the callback function. Can be NULL.
679 * @retval SR_OK Success.
680 * @retval SR_ERR_ARG Invalid argument.
681 * @retval SR_ERR_MALLOC Memory allocation error.
683 SR_API int sr_session_source_add_channel(GIOChannel *channel, int events,
684 int timeout, sr_receive_data_callback_t cb, void *cb_data)
689 g_io_channel_win32_make_pollfd(channel, events, &p);
691 p.fd = g_io_channel_unix_get_fd(channel);
695 return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)channel);
699 * Remove the source belonging to the specified channel.
701 * @todo Add more error checks and logging.
703 * @param poll_object The channel for which the source should be removed.
705 * @retval SR_OK Success
706 * @retval SR_ERR_ARG Invalid arguments
707 * @retval SR_ERR_MALLOC Memory allocation error
708 * @retval SR_ERR_BUG Internal error
710 static int _sr_session_source_remove(gintptr poll_object)
712 struct source *new_sources;
713 GPollFD *new_pollfds;
716 if (!session->sources || !session->num_sources) {
717 sr_err("%s: sources was NULL", __func__);
721 for (old = 0; old < session->num_sources; old++) {
722 if (session->sources[old].poll_object == poll_object)
726 /* fd not found, nothing to do */
727 if (old == session->num_sources)
730 session->num_sources -= 1;
732 if (old != session->num_sources) {
733 memmove(&session->pollfds[old], &session->pollfds[old+1],
734 (session->num_sources - old) * sizeof(GPollFD));
735 memmove(&session->sources[old], &session->sources[old+1],
736 (session->num_sources - old) * sizeof(struct source));
739 new_pollfds = g_try_realloc(session->pollfds, sizeof(GPollFD) * session->num_sources);
740 if (!new_pollfds && session->num_sources > 0) {
741 sr_err("%s: new_pollfds malloc failed", __func__);
742 return SR_ERR_MALLOC;
745 new_sources = g_try_realloc(session->sources, sizeof(struct source) * session->num_sources);
746 if (!new_sources && session->num_sources > 0) {
747 sr_err("%s: new_sources malloc failed", __func__);
748 return SR_ERR_MALLOC;
751 session->pollfds = new_pollfds;
752 session->sources = new_sources;
758 * Remove the source belonging to the specified file descriptor.
760 * @param fd The file descriptor for which the source should be removed.
762 * @retval SR_OK Success
763 * @retval SR_ERR_ARG Invalid argument
764 * @retval SR_ERR_MALLOC Memory allocation error.
765 * @retval SR_ERR_BUG Internal error.
767 SR_API int sr_session_source_remove(int fd)
769 return _sr_session_source_remove((gintptr)fd);
773 * Remove the source belonging to the specified poll descriptor.
775 * @param pollfd The poll descriptor for which the source should be removed.
777 * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
778 * SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
781 SR_API int sr_session_source_remove_pollfd(GPollFD *pollfd)
783 return _sr_session_source_remove((gintptr)pollfd);
787 * Remove the source belonging to the specified channel.
789 * @param channel The channel for which the source should be removed.
791 * @retval SR_OK Success.
792 * @retval SR_ERR_ARG Invalid argument.
793 * @retval SR_ERR_MALLOC Memory allocation error.
794 * @return SR_ERR_BUG Internal error.
796 SR_API int sr_session_source_remove_channel(GIOChannel *channel)
798 return _sr_session_source_remove((gintptr)channel);