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"
29 #define LOG_PREFIX "session"
35 * Creating, using, or destroying libsigrok sessions.
39 * @defgroup grp_session Session handling
41 * Creating, using, or destroying libsigrok sessions.
48 sr_receive_data_callback cb;
51 /* This is used to keep track of the object (fd, pollfd or channel) which is
52 * being polled and will be used to match the source when removing it again.
57 struct datafeed_callback {
58 sr_datafeed_callback cb;
62 /* There can only be one session at a time. */
63 /* 'session' is not static, it's used elsewhere (via 'extern'). */
64 struct sr_session *session;
67 * Create a new session.
69 * @todo Should it use the file-global "session" variable or take an argument?
70 * The same question applies to all the other session functions.
73 * @retval other A pointer to the newly allocated session.
77 SR_API struct sr_session *sr_session_new(void)
79 if (!(session = g_try_malloc0(sizeof(struct sr_session)))) {
80 sr_err("Session malloc failed.");
84 session->source_timeout = -1;
85 session->running = FALSE;
86 session->abort_session = FALSE;
87 g_mutex_init(&session->stop_mutex);
93 * Destroy the current session.
94 * This frees up all memory used by the session.
96 * @retval SR_OK Success.
97 * @retval SR_ERR_BUG No session exists.
101 SR_API int sr_session_destroy(void)
104 sr_err("%s: session was NULL", __func__);
108 sr_session_dev_remove_all();
110 /* TODO: Error checks needed? */
112 g_mutex_clear(&session->stop_mutex);
121 * Remove all the devices from the current session.
123 * The session itself (i.e., the struct sr_session) is not free'd and still
124 * exists after this function returns.
126 * @retval SR_OK Success.
127 * @retval SR_ERR_BUG No session exists.
131 SR_API int sr_session_dev_remove_all(void)
134 sr_err("%s: session was NULL", __func__);
138 g_slist_free(session->devs);
139 session->devs = NULL;
145 * Add a device instance to the current session.
147 * @param sdi The device instance to add to the current session. Must not
148 * be NULL. Also, sdi->driver and sdi->driver->dev_open must
151 * @retval SR_OK Success.
152 * @retval SR_ERR_ARG Invalid argument.
153 * @retval SR_ERR_BUG No session exists.
157 SR_API int sr_session_dev_add(const struct sr_dev_inst *sdi)
162 sr_err("%s: sdi was NULL", __func__);
167 sr_err("%s: session was NULL", __func__);
171 /* If sdi->driver is NULL, this is a virtual device. */
173 sr_dbg("%s: sdi->driver was NULL, this seems to be "
174 "a virtual device; continuing", __func__);
175 /* Just add the device, don't run dev_open(). */
176 session->devs = g_slist_append(session->devs, (gpointer)sdi);
180 /* sdi->driver is non-NULL (i.e. we have a real device). */
181 if (!sdi->driver->dev_open) {
182 sr_err("%s: sdi->driver->dev_open was NULL", __func__);
186 session->devs = g_slist_append(session->devs, (gpointer)sdi);
188 if (session->running) {
189 /* Adding a device to a running session. Commit settings
190 * and start acquisition on that device now. */
191 if ((ret = sr_config_commit(sdi)) != SR_OK) {
192 sr_err("Failed to commit device settings before "
193 "starting acquisition in running session (%s)",
197 if ((ret = sdi->driver->dev_acquisition_start(sdi,
198 (void *)sdi)) != SR_OK) {
199 sr_err("Failed to start acquisition of device in "
200 "running session (%s)", sr_strerror(ret));
209 * List all device instances attached to the current session.
211 * @param devlist A pointer where the device instance list will be
212 * stored on return. If no devices are in the session,
213 * this will be NULL. Each element in the list points
214 * to a struct sr_dev_inst *.
215 * The list must be freed by the caller, but not the
216 * elements pointed to.
218 * @retval SR_OK Success.
219 * @retval SR_ERR Invalid argument.
223 SR_API int sr_session_dev_list(GSList **devlist)
231 *devlist = g_slist_copy(session->devs);
237 * Remove all datafeed callbacks in the current session.
239 * @retval SR_OK Success.
240 * @retval SR_ERR_BUG No session exists.
244 SR_API int sr_session_datafeed_callback_remove_all(void)
247 sr_err("%s: session was NULL", __func__);
251 g_slist_free_full(session->datafeed_callbacks, g_free);
252 session->datafeed_callbacks = NULL;
258 * Add a datafeed callback to the current session.
260 * @param cb Function to call when a chunk of data is received.
262 * @param cb_data Opaque pointer passed in by the caller.
264 * @retval SR_OK Success.
265 * @retval SR_ERR_BUG No session exists.
269 SR_API int sr_session_datafeed_callback_add(sr_datafeed_callback cb, void *cb_data)
271 struct datafeed_callback *cb_struct;
274 sr_err("%s: session was NULL", __func__);
279 sr_err("%s: cb was NULL", __func__);
283 if (!(cb_struct = g_try_malloc0(sizeof(struct datafeed_callback))))
284 return SR_ERR_MALLOC;
287 cb_struct->cb_data = cb_data;
289 session->datafeed_callbacks =
290 g_slist_append(session->datafeed_callbacks, cb_struct);
296 * Call every device in the session's callback.
298 * For sessions not driven by select loops such as sr_session_run(),
299 * but driven by another scheduler, this can be used to poll the devices
300 * from within that scheduler.
302 * @param block If TRUE, this call will wait for any of the session's
303 * sources to fire an event on the file descriptors, or
304 * any of their timeouts to activate. In other words, this
305 * can be used as a select loop.
306 * If FALSE, all sources have their callback run, regardless
307 * of file descriptor or timeout status.
309 * @retval SR_OK Success.
310 * @retval SR_ERR Error occured.
312 static int sr_session_iteration(gboolean block)
317 ret = g_poll(session->pollfds, session->num_sources,
318 block ? session->source_timeout : 0);
319 for (i = 0; i < session->num_sources; i++) {
320 if (session->pollfds[i].revents > 0 || (ret == 0
321 && session->source_timeout == session->sources[i].timeout)) {
323 * Invoke the source's callback on an event,
324 * or if the poll timed out and this source
325 * asked for that timeout.
327 if (!session->sources[i].cb(session->pollfds[i].fd,
328 session->pollfds[i].revents,
329 session->sources[i].cb_data))
330 sr_session_source_remove(session->sources[i].poll_object);
333 * We want to take as little time as possible to stop
334 * the session if we have been told to do so. Therefore,
335 * we check the flag after processing every source, not
336 * just once per main event loop.
338 g_mutex_lock(&session->stop_mutex);
339 if (session->abort_session) {
340 sr_session_stop_sync();
341 /* But once is enough. */
342 session->abort_session = FALSE;
344 g_mutex_unlock(&session->stop_mutex);
353 * There can only be one session at a time.
355 * @retval SR_OK Success.
356 * @retval SR_ERR Error occured.
360 SR_API int sr_session_start(void)
362 struct sr_dev_inst *sdi;
367 sr_err("%s: session was NULL; a session must be "
368 "created before starting it.", __func__);
372 if (!session->devs) {
373 sr_err("%s: session->devs was NULL; a session "
374 "cannot be started without devices.", __func__);
378 sr_info("Starting.");
381 for (l = session->devs; l; l = l->next) {
383 if ((ret = sr_config_commit(sdi)) != SR_OK) {
384 sr_err("Failed to commit device settings before "
385 "starting acquisition (%s)", sr_strerror(ret));
388 if ((ret = sdi->driver->dev_acquisition_start(sdi, sdi)) != SR_OK) {
389 sr_err("%s: could not start an acquisition "
390 "(%s)", __func__, sr_strerror(ret));
395 /* TODO: What if there are multiple devices? Which return code? */
403 * @retval SR_OK Success.
404 * @retval SR_ERR_BUG Error occured.
408 SR_API int sr_session_run(void)
411 sr_err("%s: session was NULL; a session must be "
412 "created first, before running it.", __func__);
416 if (!session->devs) {
417 /* TODO: Actually the case? */
418 sr_err("%s: session->devs was NULL; a session "
419 "cannot be run without devices.", __func__);
422 session->running = TRUE;
426 /* Do we have real sources? */
427 if (session->num_sources == 1 && session->pollfds[0].fd == -1) {
428 /* Dummy source, freewheel over it. */
429 while (session->num_sources)
430 session->sources[0].cb(-1, 0, session->sources[0].cb_data);
432 /* Real sources, use g_poll() main loop. */
433 while (session->num_sources)
434 sr_session_iteration(TRUE);
441 * Stop the current session.
443 * The current session is stopped immediately, with all acquisition sessions
444 * being stopped and hardware drivers cleaned up.
446 * This must be called from within the session thread, to prevent freeing
447 * resources that the session thread will try to use.
449 * @retval SR_OK Success.
450 * @retval SR_ERR_BUG No session exists.
454 SR_PRIV int sr_session_stop_sync(void)
456 struct sr_dev_inst *sdi;
460 sr_err("%s: session was NULL", __func__);
464 sr_info("Stopping.");
466 for (l = session->devs; l; l = l->next) {
469 if (sdi->driver->dev_acquisition_stop)
470 sdi->driver->dev_acquisition_stop(sdi, sdi);
473 session->running = FALSE;
479 * Stop the current session.
481 * The current session is stopped immediately, with all acquisition sessions
482 * being stopped and hardware drivers cleaned up.
484 * If the session is run in a separate thread, this function will not block
485 * until the session is finished executing. It is the caller's responsibility
486 * to wait for the session thread to return before assuming that the session is
487 * completely decommissioned.
489 * @retval SR_OK Success.
490 * @retval SR_ERR_BUG No session exists.
494 SR_API int sr_session_stop(void)
497 sr_err("%s: session was NULL", __func__);
501 g_mutex_lock(&session->stop_mutex);
502 session->abort_session = TRUE;
503 g_mutex_unlock(&session->stop_mutex);
511 * @param packet The packet to show debugging information for.
513 static void datafeed_dump(const struct sr_datafeed_packet *packet)
515 const struct sr_datafeed_logic *logic;
516 const struct sr_datafeed_analog *analog;
518 switch (packet->type) {
520 sr_dbg("bus: Received SR_DF_HEADER packet.");
523 sr_dbg("bus: Received SR_DF_TRIGGER packet.");
526 sr_dbg("bus: Received SR_DF_META packet.");
529 logic = packet->payload;
530 sr_dbg("bus: Received SR_DF_LOGIC packet (%" PRIu64 " bytes, "
531 "unitsize = %d).", logic->length, logic->unitsize);
534 analog = packet->payload;
535 sr_dbg("bus: Received SR_DF_ANALOG packet (%d samples).",
536 analog->num_samples);
539 sr_dbg("bus: Received SR_DF_END packet.");
541 case SR_DF_FRAME_BEGIN:
542 sr_dbg("bus: Received SR_DF_FRAME_BEGIN packet.");
544 case SR_DF_FRAME_END:
545 sr_dbg("bus: Received SR_DF_FRAME_END packet.");
548 sr_dbg("bus: Received unknown packet type: %d.", packet->type);
554 * Send a packet to whatever is listening on the datafeed bus.
556 * Hardware drivers use this to send a data packet to the frontend.
559 * @param packet The datafeed packet to send to the session bus.
561 * @retval SR_OK Success.
562 * @retval SR_ERR_ARG Invalid argument.
566 SR_PRIV int sr_session_send(const struct sr_dev_inst *sdi,
567 const struct sr_datafeed_packet *packet)
570 struct datafeed_callback *cb_struct;
573 sr_err("%s: sdi was NULL", __func__);
578 sr_err("%s: packet was NULL", __func__);
582 for (l = session->datafeed_callbacks; l; l = l->next) {
583 if (sr_log_loglevel_get() >= SR_LOG_DBG)
584 datafeed_dump(packet);
586 cb_struct->cb(sdi, packet, cb_struct->cb_data);
593 * Add an event source for a file descriptor.
595 * @param pollfd The GPollFD.
596 * @param[in] timeout Max time to wait before the callback is called,
598 * @param cb Callback function to add. Must not be NULL.
599 * @param cb_data Data for the callback function. Can be NULL.
600 * @param poll_object TODO.
602 * @retval SR_OK Success.
603 * @retval SR_ERR_ARG Invalid argument.
604 * @retval SR_ERR_MALLOC Memory allocation error.
606 static int _sr_session_source_add(GPollFD *pollfd, int timeout,
607 sr_receive_data_callback cb, void *cb_data, gintptr poll_object)
609 struct source *new_sources, *s;
610 GPollFD *new_pollfds;
613 sr_err("%s: cb was NULL", __func__);
617 /* Note: cb_data can be NULL, that's not a bug. */
619 new_pollfds = g_try_realloc(session->pollfds,
620 sizeof(GPollFD) * (session->num_sources + 1));
622 sr_err("%s: new_pollfds malloc failed", __func__);
623 return SR_ERR_MALLOC;
626 new_sources = g_try_realloc(session->sources, sizeof(struct source) *
627 (session->num_sources + 1));
629 sr_err("%s: new_sources malloc failed", __func__);
630 return SR_ERR_MALLOC;
633 new_pollfds[session->num_sources] = *pollfd;
634 s = &new_sources[session->num_sources++];
635 s->timeout = timeout;
637 s->cb_data = cb_data;
638 s->poll_object = poll_object;
639 session->pollfds = new_pollfds;
640 session->sources = new_sources;
642 if (timeout != session->source_timeout && timeout > 0
643 && (session->source_timeout == -1 || timeout < session->source_timeout))
644 session->source_timeout = timeout;
650 * Add an event source for a file descriptor.
652 * @param fd The file descriptor.
653 * @param events Events to check for.
654 * @param timeout Max time to wait before the callback is called, ignored if 0.
655 * @param cb Callback function to add. Must not be NULL.
656 * @param cb_data Data for the callback function. Can be NULL.
658 * @retval SR_OK Success.
659 * @retval SR_ERR_ARG Invalid argument.
660 * @retval SR_ERR_MALLOC Memory allocation error.
664 SR_API int sr_session_source_add(int fd, int events, int timeout,
665 sr_receive_data_callback cb, void *cb_data)
672 return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)fd);
676 * Add an event source for a GPollFD.
678 * @param pollfd The GPollFD.
679 * @param timeout Max time to wait before the callback is called, ignored if 0.
680 * @param cb Callback function to add. Must not be NULL.
681 * @param cb_data Data for the callback function. Can be NULL.
683 * @retval SR_OK Success.
684 * @retval SR_ERR_ARG Invalid argument.
685 * @retval SR_ERR_MALLOC Memory allocation error.
689 SR_API int sr_session_source_add_pollfd(GPollFD *pollfd, int timeout,
690 sr_receive_data_callback cb, void *cb_data)
692 return _sr_session_source_add(pollfd, timeout, cb,
693 cb_data, (gintptr)pollfd);
697 * Add an event source for a GIOChannel.
699 * @param channel The GIOChannel.
700 * @param events Events to poll on.
701 * @param timeout Max time to wait before the callback is called, ignored if 0.
702 * @param cb Callback function to add. Must not be NULL.
703 * @param cb_data Data for the callback function. Can be NULL.
705 * @retval SR_OK Success.
706 * @retval SR_ERR_ARG Invalid argument.
707 * @retval SR_ERR_MALLOC Memory allocation error.
711 SR_API int sr_session_source_add_channel(GIOChannel *channel, int events,
712 int timeout, sr_receive_data_callback cb, void *cb_data)
717 g_io_channel_win32_make_pollfd(channel, events, &p);
719 p.fd = g_io_channel_unix_get_fd(channel);
723 return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)channel);
727 * Remove the source belonging to the specified channel.
729 * @todo Add more error checks and logging.
731 * @param poll_object The channel for which the source should be removed.
733 * @retval SR_OK Success
734 * @retval SR_ERR_ARG Invalid arguments
735 * @retval SR_ERR_MALLOC Memory allocation error
736 * @retval SR_ERR_BUG Internal error
738 static int _sr_session_source_remove(gintptr poll_object)
740 struct source *new_sources;
741 GPollFD *new_pollfds;
744 if (!session->sources || !session->num_sources) {
745 sr_err("%s: sources was NULL", __func__);
749 for (old = 0; old < session->num_sources; old++) {
750 if (session->sources[old].poll_object == poll_object)
754 /* fd not found, nothing to do */
755 if (old == session->num_sources)
758 session->num_sources -= 1;
760 if (old != session->num_sources) {
761 memmove(&session->pollfds[old], &session->pollfds[old+1],
762 (session->num_sources - old) * sizeof(GPollFD));
763 memmove(&session->sources[old], &session->sources[old+1],
764 (session->num_sources - old) * sizeof(struct source));
767 new_pollfds = g_try_realloc(session->pollfds, sizeof(GPollFD) * session->num_sources);
768 if (!new_pollfds && session->num_sources > 0) {
769 sr_err("%s: new_pollfds malloc failed", __func__);
770 return SR_ERR_MALLOC;
773 new_sources = g_try_realloc(session->sources, sizeof(struct source) * session->num_sources);
774 if (!new_sources && session->num_sources > 0) {
775 sr_err("%s: new_sources malloc failed", __func__);
776 return SR_ERR_MALLOC;
779 session->pollfds = new_pollfds;
780 session->sources = new_sources;
786 * Remove the source belonging to the specified file descriptor.
788 * @param fd The file descriptor for which the source should be removed.
790 * @retval SR_OK Success
791 * @retval SR_ERR_ARG Invalid argument
792 * @retval SR_ERR_MALLOC Memory allocation error.
793 * @retval SR_ERR_BUG Internal error.
797 SR_API int sr_session_source_remove(int fd)
799 return _sr_session_source_remove((gintptr)fd);
803 * Remove the source belonging to the specified poll descriptor.
805 * @param pollfd The poll descriptor for which the source should be removed.
807 * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
808 * SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
813 SR_API int sr_session_source_remove_pollfd(GPollFD *pollfd)
815 return _sr_session_source_remove((gintptr)pollfd);
819 * Remove the source belonging to the specified channel.
821 * @param channel The channel for which the source should be removed.
823 * @retval SR_OK Success.
824 * @retval SR_ERR_ARG Invalid argument.
825 * @retval SR_ERR_MALLOC Memory allocation error.
826 * @return SR_ERR_BUG Internal error.
830 SR_API int sr_session_source_remove_channel(GIOChannel *channel)
832 return _sr_session_source_remove((gintptr)channel);