libsigrok/session.c

911 lines
22 KiB
C

/*
* This file is part of the libsigrok project.
*
* Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <glib.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
/** @cond PRIVATE */
#define LOG_PREFIX "session"
/** @endcond */
/**
* @file
*
* Creating, using, or destroying libsigrok sessions.
*/
/**
* @defgroup grp_session Session handling
*
* Creating, using, or destroying libsigrok sessions.
*
* @{
*/
struct source {
int timeout;
sr_receive_data_callback cb;
void *cb_data;
/* This is used to keep track of the object (fd, pollfd or channel) which is
* being polled and will be used to match the source when removing it again.
*/
gintptr poll_object;
};
struct datafeed_callback {
sr_datafeed_callback cb;
void *cb_data;
};
/**
* Create a new session.
* Currently, there can be only one session at a time within the same process.
*
* @retval SR_OK Success.
* @retval SR_ERR_BUG A session exists already.
*
* @since 0.4.0
*/
SR_API int sr_session_new(struct sr_session **new_session)
{
struct sr_session *session;
session = g_malloc0(sizeof(struct sr_session));
session->source_timeout = -1;
session->running = FALSE;
session->abort_session = FALSE;
g_mutex_init(&session->stop_mutex);
*new_session = session;
return SR_OK;
}
/**
* Destroy a session.
* This frees up all memory used by the session.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid session passed.
*
* @since 0.4.0
*/
SR_API int sr_session_destroy(struct sr_session *session)
{
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_ARG;
}
sr_session_dev_remove_all(session);
g_mutex_clear(&session->stop_mutex);
if (session->trigger)
sr_trigger_free(session->trigger);
g_free(session);
return SR_OK;
}
/**
* Remove all the devices from a session.
*
* The session itself (i.e., the struct sr_session) is not free'd and still
* exists after this function returns.
*
* @retval SR_OK Success.
* @retval SR_ERR_BUG Invalid session passed.
*
* @since 0.4.0
*/
SR_API int sr_session_dev_remove_all(struct sr_session *session)
{
struct sr_dev_inst *sdi;
GSList *l;
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_ARG;
}
for (l = session->devs; l; l = l->next) {
sdi = (struct sr_dev_inst *) l->data;
sdi->session = NULL;
}
g_slist_free(session->devs);
session->devs = NULL;
return SR_OK;
}
/**
* Add a device instance to a session.
*
* @param sdi The device instance to add to a session. Must not
* be NULL. Also, sdi->driver and sdi->driver->dev_open must
* not be NULL.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid argument.
*
* @since 0.4.0
*/
SR_API int sr_session_dev_add(struct sr_session *session,
struct sr_dev_inst *sdi)
{
int ret;
if (!sdi) {
sr_err("%s: sdi was NULL", __func__);
return SR_ERR_ARG;
}
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_ARG;
}
/* If sdi->session is not NULL, the device is already in this or
* another session. */
if (sdi->session) {
sr_err("%s: already assigned to session", __func__);
return SR_ERR_ARG;
}
/* If sdi->driver is NULL, this is a virtual device. */
if (!sdi->driver) {
sr_dbg("%s: sdi->driver was NULL, this seems to be "
"a virtual device; continuing", __func__);
/* Just add the device, don't run dev_open(). */
session->devs = g_slist_append(session->devs, (gpointer)sdi);
sdi->session = session;
return SR_OK;
}
/* sdi->driver is non-NULL (i.e. we have a real device). */
if (!sdi->driver->dev_open) {
sr_err("%s: sdi->driver->dev_open was NULL", __func__);
return SR_ERR_BUG;
}
session->devs = g_slist_append(session->devs, (gpointer)sdi);
sdi->session = session;
if (session->running) {
/* Adding a device to a running session. Commit settings
* and start acquisition on that device now. */
if ((ret = sr_config_commit(sdi)) != SR_OK) {
sr_err("Failed to commit device settings before "
"starting acquisition in running session (%s)",
sr_strerror(ret));
return ret;
}
if ((ret = sdi->driver->dev_acquisition_start(sdi,
(void *)sdi)) != SR_OK) {
sr_err("Failed to start acquisition of device in "
"running session (%s)", sr_strerror(ret));
return ret;
}
}
return SR_OK;
}
/**
* List all device instances attached to a session.
*
* @param devlist A pointer where the device instance list will be
* stored on return. If no devices are in the session,
* this will be NULL. Each element in the list points
* to a struct sr_dev_inst *.
* The list must be freed by the caller, but not the
* elements pointed to.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid argument.
*
* @since 0.4.0
*/
SR_API int sr_session_dev_list(struct sr_session *session, GSList **devlist)
{
if (!session)
return SR_ERR_ARG;
if (!devlist)
return SR_ERR_ARG;
*devlist = g_slist_copy(session->devs);
return SR_OK;
}
/**
* Remove all datafeed callbacks in a session.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid session passed.
*
* @since 0.4.0
*/
SR_API int sr_session_datafeed_callback_remove_all(struct sr_session *session)
{
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_ARG;
}
g_slist_free_full(session->datafeed_callbacks, g_free);
session->datafeed_callbacks = NULL;
return SR_OK;
}
/**
* Add a datafeed callback to a session.
*
* @param cb Function to call when a chunk of data is received.
* Must not be NULL.
* @param cb_data Opaque pointer passed in by the caller.
*
* @retval SR_OK Success.
* @retval SR_ERR_BUG No session exists.
*
* @since 0.3.0
*/
SR_API int sr_session_datafeed_callback_add(struct sr_session *session,
sr_datafeed_callback cb, void *cb_data)
{
struct datafeed_callback *cb_struct;
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_BUG;
}
if (!cb) {
sr_err("%s: cb was NULL", __func__);
return SR_ERR_ARG;
}
if (!(cb_struct = g_try_malloc0(sizeof(struct datafeed_callback))))
return SR_ERR_MALLOC;
cb_struct->cb = cb;
cb_struct->cb_data = cb_data;
session->datafeed_callbacks =
g_slist_append(session->datafeed_callbacks, cb_struct);
return SR_OK;
}
SR_API struct sr_trigger *sr_session_trigger_get(struct sr_session *session)
{
return session->trigger;
}
SR_API int sr_session_trigger_set(struct sr_session *session, struct sr_trigger *trig)
{
session->trigger = trig;
return SR_OK;
}
/**
* Call every device in the current session's callback.
*
* For sessions not driven by select loops such as sr_session_run(),
* but driven by another scheduler, this can be used to poll the devices
* from within that scheduler.
*
* @param block If TRUE, this call will wait for any of the session's
* sources to fire an event on the file descriptors, or
* any of their timeouts to activate. In other words, this
* can be used as a select loop.
* If FALSE, all sources have their callback run, regardless
* of file descriptor or timeout status.
*
* @retval SR_OK Success.
* @retval SR_ERR Error occured.
*/
static int sr_session_iteration(struct sr_session *session, gboolean block)
{
unsigned int i;
int ret;
ret = g_poll(session->pollfds, session->num_sources,
block ? session->source_timeout : 0);
for (i = 0; i < session->num_sources; i++) {
if (session->pollfds[i].revents > 0 || (ret == 0
&& session->source_timeout == session->sources[i].timeout)) {
/*
* Invoke the source's callback on an event,
* or if the poll timed out and this source
* asked for that timeout.
*/
if (!session->sources[i].cb(session->pollfds[i].fd,
session->pollfds[i].revents,
session->sources[i].cb_data))
sr_session_source_remove(session,
session->sources[i].poll_object);
}
/*
* We want to take as little time as possible to stop
* the session if we have been told to do so. Therefore,
* we check the flag after processing every source, not
* just once per main event loop.
*/
g_mutex_lock(&session->stop_mutex);
if (session->abort_session) {
sr_session_stop_sync(session);
/* But once is enough. */
session->abort_session = FALSE;
}
g_mutex_unlock(&session->stop_mutex);
}
return SR_OK;
}
static int verify_trigger(struct sr_trigger *trigger)
{
struct sr_trigger_stage *stage;
struct sr_trigger_match *match;
GSList *l, *m;
if (!trigger->stages) {
sr_err("No trigger stages defined.");
return SR_ERR;
}
sr_spew("Checking trigger:");
for (l = trigger->stages; l; l = l->next) {
stage = l->data;
if (!stage->matches) {
sr_err("Stage %d has no matches defined.", stage->stage);
return SR_ERR;
}
for (m = stage->matches; m; m = m->next) {
match = m->data;
if (!match->channel) {
sr_err("Stage %d match has no channel.", stage->stage);
return SR_ERR;
}
if (!match->match) {
sr_err("Stage %d match is not defined.", stage->stage);
return SR_ERR;
}
sr_spew("Stage %d match on channel %s, match %d", stage->stage,
match->channel->name, match->match);
}
}
return SR_OK;
}
/**
* Start a session.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid session passed.
*
* @since 0.4.0
*/
SR_API int sr_session_start(struct sr_session *session)
{
struct sr_dev_inst *sdi;
GSList *l;
int ret;
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_ARG;
}
if (!session->devs) {
sr_err("%s: session->devs was NULL; a session "
"cannot be started without devices.", __func__);
return SR_ERR_ARG;
}
if (session->trigger && verify_trigger(session->trigger) != SR_OK)
return SR_ERR;
sr_info("Starting.");
ret = SR_OK;
for (l = session->devs; l; l = l->next) {
sdi = l->data;
if ((ret = sr_config_commit(sdi)) != SR_OK) {
sr_err("Failed to commit device settings before "
"starting acquisition (%s)", sr_strerror(ret));
break;
}
if ((ret = sdi->driver->dev_acquisition_start(sdi, sdi)) != SR_OK) {
sr_err("%s: could not start an acquisition "
"(%s)", __func__, sr_strerror(ret));
break;
}
}
/* TODO: What if there are multiple devices? Which return code? */
return ret;
}
/**
* Run a session.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid session passed.
*
* @since 0.4.0
*/
SR_API int sr_session_run(struct sr_session *session)
{
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_ARG;
}
if (!session->devs) {
/* TODO: Actually the case? */
sr_err("%s: session->devs was NULL; a session "
"cannot be run without devices.", __func__);
return SR_ERR_ARG;
}
session->running = TRUE;
sr_info("Running.");
/* Do we have real sources? */
if (session->num_sources == 1 && session->pollfds[0].fd == -1) {
/* Dummy source, freewheel over it. */
while (session->num_sources)
session->sources[0].cb(-1, 0, session->sources[0].cb_data);
} else {
/* Real sources, use g_poll() main loop. */
while (session->num_sources)
sr_session_iteration(session, TRUE);
}
return SR_OK;
}
/**
* Stop a session.
*
* The session is stopped immediately, with all acquisition sessions stopped
* and hardware drivers cleaned up.
*
* This must be called from within the session thread, to prevent freeing
* resources that the session thread will try to use.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid session passed.
*
* @private
*/
SR_PRIV int sr_session_stop_sync(struct sr_session *session)
{
struct sr_dev_inst *sdi;
GSList *l;
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_ARG;
}
sr_info("Stopping.");
for (l = session->devs; l; l = l->next) {
sdi = l->data;
if (sdi->driver) {
if (sdi->driver->dev_acquisition_stop)
sdi->driver->dev_acquisition_stop(sdi, sdi);
}
}
session->running = FALSE;
return SR_OK;
}
/**
* Stop a session.
*
* The session is stopped immediately, with all acquisition sessions being
* stopped and hardware drivers cleaned up.
*
* If the session is run in a separate thread, this function will not block
* until the session is finished executing. It is the caller's responsibility
* to wait for the session thread to return before assuming that the session is
* completely decommissioned.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid session passed.
*
* @since 0.4.0
*/
SR_API int sr_session_stop(struct sr_session *session)
{
if (!session) {
sr_err("%s: session was NULL", __func__);
return SR_ERR_BUG;
}
g_mutex_lock(&session->stop_mutex);
session->abort_session = TRUE;
g_mutex_unlock(&session->stop_mutex);
return SR_OK;
}
/**
* Debug helper.
*
* @param packet The packet to show debugging information for.
*/
static void datafeed_dump(const struct sr_datafeed_packet *packet)
{
const struct sr_datafeed_logic *logic;
const struct sr_datafeed_analog *analog;
switch (packet->type) {
case SR_DF_HEADER:
sr_dbg("bus: Received SR_DF_HEADER packet.");
break;
case SR_DF_TRIGGER:
sr_dbg("bus: Received SR_DF_TRIGGER packet.");
break;
case SR_DF_META:
sr_dbg("bus: Received SR_DF_META packet.");
break;
case SR_DF_LOGIC:
logic = packet->payload;
sr_dbg("bus: Received SR_DF_LOGIC packet (%" PRIu64 " bytes, "
"unitsize = %d).", logic->length, logic->unitsize);
break;
case SR_DF_ANALOG:
analog = packet->payload;
sr_dbg("bus: Received SR_DF_ANALOG packet (%d samples).",
analog->num_samples);
break;
case SR_DF_END:
sr_dbg("bus: Received SR_DF_END packet.");
break;
case SR_DF_FRAME_BEGIN:
sr_dbg("bus: Received SR_DF_FRAME_BEGIN packet.");
break;
case SR_DF_FRAME_END:
sr_dbg("bus: Received SR_DF_FRAME_END packet.");
break;
default:
sr_dbg("bus: Received unknown packet type: %d.", packet->type);
break;
}
}
/**
* Send a packet to whatever is listening on the datafeed bus.
*
* Hardware drivers use this to send a data packet to the frontend.
*
* @param sdi TODO.
* @param packet The datafeed packet to send to the session bus.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid argument.
*
* @private
*/
SR_PRIV int sr_session_send(const struct sr_dev_inst *sdi,
const struct sr_datafeed_packet *packet)
{
GSList *l;
struct datafeed_callback *cb_struct;
if (!sdi) {
sr_err("%s: sdi was NULL", __func__);
return SR_ERR_ARG;
}
if (!packet) {
sr_err("%s: packet was NULL", __func__);
return SR_ERR_ARG;
}
for (l = sdi->session->datafeed_callbacks; l; l = l->next) {
if (sr_log_loglevel_get() >= SR_LOG_DBG)
datafeed_dump(packet);
cb_struct = l->data;
cb_struct->cb(sdi, packet, cb_struct->cb_data);
}
return SR_OK;
}
/**
* Add an event source for a file descriptor.
*
* @param pollfd The GPollFD.
* @param[in] timeout Max time to wait before the callback is called,
* ignored if 0.
* @param cb Callback function to add. Must not be NULL.
* @param cb_data Data for the callback function. Can be NULL.
* @param poll_object TODO.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid argument.
* @retval SR_ERR_MALLOC Memory allocation error.
*/
static int _sr_session_source_add(struct sr_session *session, GPollFD *pollfd,
int timeout, sr_receive_data_callback cb, void *cb_data, gintptr poll_object)
{
struct source *new_sources, *s;
GPollFD *new_pollfds;
if (!cb) {
sr_err("%s: cb was NULL", __func__);
return SR_ERR_ARG;
}
/* Note: cb_data can be NULL, that's not a bug. */
new_pollfds = g_try_realloc(session->pollfds,
sizeof(GPollFD) * (session->num_sources + 1));
if (!new_pollfds) {
sr_err("%s: new_pollfds malloc failed", __func__);
return SR_ERR_MALLOC;
}
new_sources = g_try_realloc(session->sources, sizeof(struct source) *
(session->num_sources + 1));
if (!new_sources) {
sr_err("%s: new_sources malloc failed", __func__);
return SR_ERR_MALLOC;
}
new_pollfds[session->num_sources] = *pollfd;
s = &new_sources[session->num_sources++];
s->timeout = timeout;
s->cb = cb;
s->cb_data = cb_data;
s->poll_object = poll_object;
session->pollfds = new_pollfds;
session->sources = new_sources;
if (timeout != session->source_timeout && timeout > 0
&& (session->source_timeout == -1 || timeout < session->source_timeout))
session->source_timeout = timeout;
return SR_OK;
}
/**
* Add an event source for a file descriptor.
*
* @param fd The file descriptor.
* @param events Events to check for.
* @param timeout Max time to wait before the callback is called, ignored if 0.
* @param cb Callback function to add. Must not be NULL.
* @param cb_data Data for the callback function. Can be NULL.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid argument.
* @retval SR_ERR_MALLOC Memory allocation error.
*
* @since 0.3.0
*/
SR_API int sr_session_source_add(struct sr_session *session, int fd,
int events, int timeout, sr_receive_data_callback cb, void *cb_data)
{
GPollFD p;
(void) session;
p.fd = fd;
p.events = events;
return _sr_session_source_add(session, &p, timeout, cb, cb_data, (gintptr)fd);
}
/**
* Add an event source for a GPollFD.
*
* @param pollfd The GPollFD.
* @param timeout Max time to wait before the callback is called, ignored if 0.
* @param cb Callback function to add. Must not be NULL.
* @param cb_data Data for the callback function. Can be NULL.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid argument.
* @retval SR_ERR_MALLOC Memory allocation error.
*
* @since 0.3.0
*/
SR_API int sr_session_source_add_pollfd(struct sr_session *session,
GPollFD *pollfd, int timeout, sr_receive_data_callback cb,
void *cb_data)
{
(void) session;
return _sr_session_source_add(session, pollfd, timeout, cb,
cb_data, (gintptr)pollfd);
}
/**
* Add an event source for a GIOChannel.
*
* @param channel The GIOChannel.
* @param events Events to poll on.
* @param timeout Max time to wait before the callback is called, ignored if 0.
* @param cb Callback function to add. Must not be NULL.
* @param cb_data Data for the callback function. Can be NULL.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid argument.
* @retval SR_ERR_MALLOC Memory allocation error.
*
* @since 0.3.0
*/
SR_API int sr_session_source_add_channel(struct sr_session *session,
GIOChannel *channel, int events, int timeout,
sr_receive_data_callback cb, void *cb_data)
{
GPollFD p;
(void) session;
#ifdef _WIN32
g_io_channel_win32_make_pollfd(channel, events, &p);
#else
p.fd = g_io_channel_unix_get_fd(channel);
p.events = events;
#endif
return _sr_session_source_add(session, &p, timeout, cb, cb_data, (gintptr)channel);
}
/**
* Remove the source belonging to the specified channel.
*
* @todo Add more error checks and logging.
*
* @param poll_object The channel for which the source should be removed.
*
* @retval SR_OK Success
* @retval SR_ERR_ARG Invalid arguments
* @retval SR_ERR_MALLOC Memory allocation error
* @retval SR_ERR_BUG Internal error
*/
static int _sr_session_source_remove(struct sr_session *session, gintptr poll_object)
{
struct source *new_sources;
GPollFD *new_pollfds;
unsigned int old;
if (!session->sources || !session->num_sources) {
sr_err("%s: sources was NULL", __func__);
return SR_ERR_BUG;
}
for (old = 0; old < session->num_sources; old++) {
if (session->sources[old].poll_object == poll_object)
break;
}
/* fd not found, nothing to do */
if (old == session->num_sources)
return SR_OK;
session->num_sources -= 1;
if (old != session->num_sources) {
memmove(&session->pollfds[old], &session->pollfds[old+1],
(session->num_sources - old) * sizeof(GPollFD));
memmove(&session->sources[old], &session->sources[old+1],
(session->num_sources - old) * sizeof(struct source));
}
new_pollfds = g_try_realloc(session->pollfds, sizeof(GPollFD) * session->num_sources);
if (!new_pollfds && session->num_sources > 0) {
sr_err("%s: new_pollfds malloc failed", __func__);
return SR_ERR_MALLOC;
}
new_sources = g_try_realloc(session->sources, sizeof(struct source) * session->num_sources);
if (!new_sources && session->num_sources > 0) {
sr_err("%s: new_sources malloc failed", __func__);
return SR_ERR_MALLOC;
}
session->pollfds = new_pollfds;
session->sources = new_sources;
return SR_OK;
}
/**
* Remove the source belonging to the specified file descriptor.
*
* @param fd The file descriptor for which the source should be removed.
*
* @retval SR_OK Success
* @retval SR_ERR_ARG Invalid argument
* @retval SR_ERR_MALLOC Memory allocation error.
* @retval SR_ERR_BUG Internal error.
*
* @since 0.3.0
*/
SR_API int sr_session_source_remove(struct sr_session *session, int fd)
{
(void) session;
return _sr_session_source_remove(session, (gintptr)fd);
}
/**
* Remove the source belonging to the specified poll descriptor.
*
* @param pollfd The poll descriptor for which the source should be removed.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
* SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
* internal errors.
*
* @since 0.2.0
*/
SR_API int sr_session_source_remove_pollfd(struct sr_session *session,
GPollFD *pollfd)
{
(void) session;
return _sr_session_source_remove(session, (gintptr)pollfd);
}
/**
* Remove the source belonging to the specified channel.
*
* @param channel The channel for which the source should be removed.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid argument.
* @retval SR_ERR_MALLOC Memory allocation error.
* @return SR_ERR_BUG Internal error.
*
* @since 0.2.0
*/
SR_API int sr_session_source_remove_channel(struct sr_session *session,
GIOChannel *channel)
{
(void) session;
return _sr_session_source_remove(session, (gintptr)channel);
}
/** @} */