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. Start acquisition
180 * on that device now. */
181 if ((ret = sdi->driver->dev_acquisition_start(sdi,
182 (void *)sdi)) != SR_OK)
183 sr_err("Failed to start acquisition of device in "
184 "running session: %d", ret);
191 * List all device instances attached to the current session.
193 * @param devlist A pointer where the device instance list will be
194 * stored on return. If no devices are in the session,
195 * this will be NULL. Each element in the list points
196 * to a struct sr_dev_inst *.
197 * The list must be freed by the caller, but not the
198 * elements pointed to.
200 * @retval SR_OK Success.
201 * @retval SR_ERR Invalid argument.
203 SR_API int sr_session_dev_list(GSList **devlist)
211 *devlist = g_slist_copy(session->devs);
217 * Remove all datafeed callbacks in the current session.
219 * @retval SR_OK Success.
220 * @retval SR_ERR_BUG No session exists.
222 SR_API int sr_session_datafeed_callback_remove_all(void)
225 sr_err("%s: session was NULL", __func__);
229 g_slist_free_full(session->datafeed_callbacks, g_free);
230 session->datafeed_callbacks = NULL;
236 * Add a datafeed callback to the current session.
238 * @param cb Function to call when a chunk of data is received.
240 * @param cb_data Opaque pointer passed in by the caller.
242 * @retval SR_OK Success.
243 * @retval SR_ERR_BUG No session exists.
245 SR_API int sr_session_datafeed_callback_add(sr_datafeed_callback_t cb, void *cb_data)
247 struct datafeed_callback *cb_struct;
250 sr_err("%s: session was NULL", __func__);
255 sr_err("%s: cb was NULL", __func__);
259 if (!(cb_struct = g_try_malloc0(sizeof(struct datafeed_callback))))
260 return SR_ERR_MALLOC;
263 cb_struct->cb_data = cb_data;
265 session->datafeed_callbacks =
266 g_slist_append(session->datafeed_callbacks, cb_struct);
272 * Call every device in the session's callback.
274 * For sessions not driven by select loops such as sr_session_run(),
275 * but driven by another scheduler, this can be used to poll the devices
276 * from within that scheduler.
278 * @param block If TRUE, this call will wait for any of the session's
279 * sources to fire an event on the file descriptors, or
280 * any of their timeouts to activate. In other words, this
281 * can be used as a select loop.
282 * If FALSE, all sources have their callback run, regardless
283 * of file descriptor or timeout status.
285 * @retval SR_OK Success.
286 * @retval SR_ERR Error occured.
288 static int sr_session_iteration(gboolean block)
293 ret = g_poll(session->pollfds, session->num_sources,
294 block ? session->source_timeout : 0);
295 for (i = 0; i < session->num_sources; i++) {
296 if (session->pollfds[i].revents > 0 || (ret == 0
297 && session->source_timeout == session->sources[i].timeout)) {
299 * Invoke the source's callback on an event,
300 * or if the poll timed out and this source
301 * asked for that timeout.
303 if (!session->sources[i].cb(session->pollfds[i].fd,
304 session->pollfds[i].revents,
305 session->sources[i].cb_data))
306 sr_session_source_remove(session->sources[i].poll_object);
309 * We want to take as little time as possible to stop
310 * the session if we have been told to do so. Therefore,
311 * we check the flag after processing every source, not
312 * just once per main event loop.
314 g_mutex_lock(&session->stop_mutex);
315 if (session->abort_session) {
316 sr_session_stop_sync();
317 /* But once is enough. */
318 session->abort_session = FALSE;
320 g_mutex_unlock(&session->stop_mutex);
329 * There can only be one session at a time.
331 * @retval SR_OK Success.
332 * @retval SR_ERR Error occured.
334 SR_API int sr_session_start(void)
336 struct sr_dev_inst *sdi;
341 sr_err("%s: session was NULL; a session must be "
342 "created before starting it.", __func__);
346 if (!session->devs) {
347 sr_err("%s: session->devs was NULL; a session "
348 "cannot be started without devices.", __func__);
352 sr_info("Starting.");
355 for (l = session->devs; l; l = l->next) {
357 if ((ret = sdi->driver->dev_acquisition_start(sdi, sdi)) != SR_OK) {
358 sr_err("%s: could not start an acquisition "
359 "(%s)", __func__, sr_strerror(ret));
364 /* TODO: What if there are multiple devices? Which return code? */
372 * @retval SR_OK Success.
373 * @retval SR_ERR_BUG Error occured.
375 SR_API int sr_session_run(void)
378 sr_err("%s: session was NULL; a session must be "
379 "created first, before running it.", __func__);
383 if (!session->devs) {
384 /* TODO: Actually the case? */
385 sr_err("%s: session->devs was NULL; a session "
386 "cannot be run without devices.", __func__);
389 session->running = TRUE;
393 /* Do we have real sources? */
394 if (session->num_sources == 1 && session->pollfds[0].fd == -1) {
395 /* Dummy source, freewheel over it. */
396 while (session->num_sources)
397 session->sources[0].cb(-1, 0, session->sources[0].cb_data);
399 /* Real sources, use g_poll() main loop. */
400 while (session->num_sources)
401 sr_session_iteration(TRUE);
408 * Stop the current session.
410 * The current session is stopped immediately, with all acquisition sessions
411 * being stopped and hardware drivers cleaned up.
413 * This must be called from within the session thread, to prevent freeing
414 * resources that the session thread will try to use.
416 * @retval SR_OK Success.
417 * @retval SR_ERR_BUG No session exists.
421 SR_PRIV int sr_session_stop_sync(void)
423 struct sr_dev_inst *sdi;
427 sr_err("%s: session was NULL", __func__);
431 sr_info("Stopping.");
433 for (l = session->devs; l; l = l->next) {
436 if (sdi->driver->dev_acquisition_stop)
437 sdi->driver->dev_acquisition_stop(sdi, sdi);
440 session->running = FALSE;
446 * Stop the current session.
448 * The current session is stopped immediately, with all acquisition sessions
449 * being stopped and hardware drivers cleaned up.
451 * If the session is run in a separate thread, this function will not block
452 * until the session is finished executing. It is the caller's responsibility
453 * to wait for the session thread to return before assuming that the session is
454 * completely decommissioned.
456 * @retval SR_OK Success.
457 * @retval SR_ERR_BUG No session exists.
459 SR_API int sr_session_stop(void)
462 sr_err("%s: session was NULL", __func__);
466 g_mutex_lock(&session->stop_mutex);
467 session->abort_session = TRUE;
468 g_mutex_unlock(&session->stop_mutex);
476 * @param packet The packet to show debugging information for.
478 static void datafeed_dump(const struct sr_datafeed_packet *packet)
480 const struct sr_datafeed_logic *logic;
481 const struct sr_datafeed_analog *analog;
483 switch (packet->type) {
485 sr_dbg("bus: Received SR_DF_HEADER packet.");
488 sr_dbg("bus: Received SR_DF_TRIGGER packet.");
491 sr_dbg("bus: Received SR_DF_META packet.");
494 logic = packet->payload;
495 sr_dbg("bus: Received SR_DF_LOGIC packet (%" PRIu64 " bytes).",
499 analog = packet->payload;
500 sr_dbg("bus: Received SR_DF_ANALOG packet (%d samples).",
501 analog->num_samples);
504 sr_dbg("bus: Received SR_DF_END packet.");
506 case SR_DF_FRAME_BEGIN:
507 sr_dbg("bus: Received SR_DF_FRAME_BEGIN packet.");
509 case SR_DF_FRAME_END:
510 sr_dbg("bus: Received SR_DF_FRAME_END packet.");
513 sr_dbg("bus: Received unknown packet type: %d.", packet->type);
519 * Send a packet to whatever is listening on the datafeed bus.
521 * Hardware drivers use this to send a data packet to the frontend.
524 * @param packet The datafeed packet to send to the session bus.
526 * @retval SR_OK Success.
527 * @retval SR_ERR_ARG Invalid argument.
531 SR_PRIV int sr_session_send(const struct sr_dev_inst *sdi,
532 const struct sr_datafeed_packet *packet)
535 struct datafeed_callback *cb_struct;
538 sr_err("%s: sdi was NULL", __func__);
543 sr_err("%s: packet was NULL", __func__);
547 for (l = session->datafeed_callbacks; l; l = l->next) {
548 if (sr_log_loglevel_get() >= SR_LOG_DBG)
549 datafeed_dump(packet);
551 cb_struct->cb(sdi, packet, cb_struct->cb_data);
558 * Add an event source for a file descriptor.
560 * @param pollfd The GPollFD.
561 * @param[in] timeout Max time to wait before the callback is called,
563 * @param cb Callback function to add. Must not be NULL.
564 * @param cb_data Data for the callback function. Can be NULL.
565 * @param poll_object TODO.
567 * @retval SR_OK Success.
568 * @retval SR_ERR_ARG Invalid argument.
569 * @retval SR_ERR_MALLOC Memory allocation error.
571 static int _sr_session_source_add(GPollFD *pollfd, int timeout,
572 sr_receive_data_callback_t cb, void *cb_data, gintptr poll_object)
574 struct source *new_sources, *s;
575 GPollFD *new_pollfds;
578 sr_err("%s: cb was NULL", __func__);
582 /* Note: cb_data can be NULL, that's not a bug. */
584 new_pollfds = g_try_realloc(session->pollfds,
585 sizeof(GPollFD) * (session->num_sources + 1));
587 sr_err("%s: new_pollfds malloc failed", __func__);
588 return SR_ERR_MALLOC;
591 new_sources = g_try_realloc(session->sources, sizeof(struct source) *
592 (session->num_sources + 1));
594 sr_err("%s: new_sources malloc failed", __func__);
595 return SR_ERR_MALLOC;
598 new_pollfds[session->num_sources] = *pollfd;
599 s = &new_sources[session->num_sources++];
600 s->timeout = timeout;
602 s->cb_data = cb_data;
603 s->poll_object = poll_object;
604 session->pollfds = new_pollfds;
605 session->sources = new_sources;
607 if (timeout != session->source_timeout && timeout > 0
608 && (session->source_timeout == -1 || timeout < session->source_timeout))
609 session->source_timeout = timeout;
615 * Add an event source for a file descriptor.
617 * @param fd The file descriptor.
618 * @param events Events to check for.
619 * @param timeout Max time to wait before the callback is called, ignored if 0.
620 * @param cb Callback function to add. Must not be NULL.
621 * @param cb_data Data for the callback function. Can be NULL.
623 * @retval SR_OK Success.
624 * @retval SR_ERR_ARG Invalid argument.
625 * @retval SR_ERR_MALLOC Memory allocation error.
627 SR_API int sr_session_source_add(int fd, int events, int timeout,
628 sr_receive_data_callback_t cb, void *cb_data)
635 return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)fd);
639 * Add an event source for a GPollFD.
641 * @param pollfd The GPollFD.
642 * @param timeout Max time to wait before the callback is called, ignored if 0.
643 * @param cb Callback function to add. Must not be NULL.
644 * @param cb_data Data for the callback function. Can be NULL.
646 * @retval SR_OK Success.
647 * @retval SR_ERR_ARG Invalid argument.
648 * @retval SR_ERR_MALLOC Memory allocation error.
650 SR_API int sr_session_source_add_pollfd(GPollFD *pollfd, int timeout,
651 sr_receive_data_callback_t cb, void *cb_data)
653 return _sr_session_source_add(pollfd, timeout, cb,
654 cb_data, (gintptr)pollfd);
658 * Add an event source for a GIOChannel.
660 * @param channel The GIOChannel.
661 * @param events Events to poll on.
662 * @param timeout Max time to wait before the callback is called, ignored if 0.
663 * @param cb Callback function to add. Must not be NULL.
664 * @param cb_data Data for the callback function. Can be NULL.
666 * @retval SR_OK Success.
667 * @retval SR_ERR_ARG Invalid argument.
668 * @retval SR_ERR_MALLOC Memory allocation error.
670 SR_API int sr_session_source_add_channel(GIOChannel *channel, int events,
671 int timeout, sr_receive_data_callback_t cb, void *cb_data)
676 g_io_channel_win32_make_pollfd(channel, events, &p);
678 p.fd = g_io_channel_unix_get_fd(channel);
682 return _sr_session_source_add(&p, timeout, cb, cb_data, (gintptr)channel);
686 * Remove the source belonging to the specified channel.
688 * @todo Add more error checks and logging.
690 * @param poll_object The channel for which the source should be removed.
692 * @retval SR_OK Success
693 * @retval SR_ERR_ARG Invalid arguments
694 * @retval SR_ERR_MALLOC Memory allocation error
695 * @retval SR_ERR_BUG Internal error
697 static int _sr_session_source_remove(gintptr poll_object)
699 struct source *new_sources;
700 GPollFD *new_pollfds;
703 if (!session->sources || !session->num_sources) {
704 sr_err("%s: sources was NULL", __func__);
708 for (old = 0; old < session->num_sources; old++) {
709 if (session->sources[old].poll_object == poll_object)
713 /* fd not found, nothing to do */
714 if (old == session->num_sources)
717 session->num_sources -= 1;
719 if (old != session->num_sources) {
720 memmove(&session->pollfds[old], &session->pollfds[old+1],
721 (session->num_sources - old) * sizeof(GPollFD));
722 memmove(&session->sources[old], &session->sources[old+1],
723 (session->num_sources - old) * sizeof(struct source));
726 new_pollfds = g_try_realloc(session->pollfds, sizeof(GPollFD) * session->num_sources);
727 if (!new_pollfds && session->num_sources > 0) {
728 sr_err("%s: new_pollfds malloc failed", __func__);
729 return SR_ERR_MALLOC;
732 new_sources = g_try_realloc(session->sources, sizeof(struct source) * session->num_sources);
733 if (!new_sources && session->num_sources > 0) {
734 sr_err("%s: new_sources malloc failed", __func__);
735 return SR_ERR_MALLOC;
738 session->pollfds = new_pollfds;
739 session->sources = new_sources;
745 * Remove the source belonging to the specified file descriptor.
747 * @param fd The file descriptor for which the source should be removed.
749 * @retval SR_OK Success
750 * @retval SR_ERR_ARG Invalid argument
751 * @retval SR_ERR_MALLOC Memory allocation error.
752 * @retval SR_ERR_BUG Internal error.
754 SR_API int sr_session_source_remove(int fd)
756 return _sr_session_source_remove((gintptr)fd);
760 * Remove the source belonging to the specified poll descriptor.
762 * @param pollfd The poll descriptor for which the source should be removed.
764 * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
765 * SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
768 SR_API int sr_session_source_remove_pollfd(GPollFD *pollfd)
770 return _sr_session_source_remove((gintptr)pollfd);
774 * Remove the source belonging to the specified channel.
776 * @param channel The channel for which the source should be removed.
778 * @retval SR_OK Success.
779 * @retval SR_ERR_ARG Invalid argument.
780 * @retval SR_ERR_MALLOC Memory allocation error.
781 * @return SR_ERR_BUG Internal error.
783 SR_API int sr_session_source_remove_channel(GIOChannel *channel)
785 return _sr_session_source_remove((gintptr)channel);