/* Idle handler; invoked when the number of registered event sources
* for a running session drops to zero.
*/
static gboolean delayed_stop_check(void *data)
{
struct sr_session *session;
session = data;
session->stop_check_id = 0;
/* Session already ended? */
if (!session->running)
return G_SOURCE_REMOVE;
/* New event sources may have been installed in the meantime. */
if (g_hash_table_size(session->event_sources) != 0)
return G_SOURCE_REMOVE;
session->running = FALSE;
unset_main_context(session);
sr_info("Stopped.");
/* This indicates a bug in user code, since it is not valid to
* restart or destroy a session while it may still be running.
*/
if (!session->main_loop && !session->stopped_callback) {
sr_err("BUG: Session stop left unhandled.");
return G_SOURCE_REMOVE;
}
if (session->main_loop)
g_main_loop_quit(session->main_loop);
if (session->stopped_callback)
(*session->stopped_callback)(session->stopped_cb_data);
return G_SOURCE_REMOVE;
}
/**
* 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.
*
* @param session The session to use. Must not be NULL.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid session passed.
* @retval SR_ERR Other error.
*
* @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_ARG;
}
g_mutex_lock(&session->main_mutex);
if (session->main_context) {
g_main_context_invoke(session->main_context,
&session_stop_sync, session);
} else {
sr_err("No main context set; already stopped?");
}
g_mutex_unlock(&session->main_mutex);
return unset_main_context(session);
}
/**
* Start a session.
*
* When this function returns with a status code indicating success, the
* session is running. Use sr_session_stopped_callback_set() to receive
* notification upon completion, or call sr_session_run() to block until
* the session stops.
*
* Session events will be processed in the context of the current thread.
* If a thread-default GLib main context has been set, and is not owned by
* any other thread, it will be used. Otherwise, libsigrok will create its
* own main context for the current thread.
*
* @param session The session to use. Must not be NULL.
*
* @retval SR_OK Success.
* @retval SR_ERR_ARG Invalid session passed.
* @retval SR_ERR Other error.
*
* @since 0.4.0
*/
SR_API int sr_session_start(struct sr_session *session)
{
struct sr_dev_inst *sdi;
struct sr_channel *ch;
GSList *l, *c, *lend;
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->running) {
sr_err("Cannot (re-)start session while it is still running.");
return SR_ERR;
}
if (session->trigger) {
ret = verify_trigger(session->trigger);
if (ret != SR_OK)
return ret;
}
/* Check enabled channels and commit settings of all devices. */
for (l = session->devs; l; l = l->next) {
sdi = l->data;
for (c = sdi->channels; c; c = c->next) {
ch = c->data;
if (ch->enabled)
break;
}
if (!c) {
sr_err("%s device %s has no enabled channels.",
sdi->driver->name, sdi->connection_id);
return SR_ERR;
}
ret = sr_config_commit(sdi);
if (ret != SR_OK) {
sr_err("Failed to commit %s device %s settings "
"before starting acquisition.",
sdi->driver->name, sdi->connection_id);
return ret;
}
}
ret = set_main_context(session);
if (ret != SR_OK)
return ret;
sr_info("Starting.");
session->running = TRUE;
/* Have all devices start acquisition. */
for (l = session->devs; l; l = l->next) {
sdi = l->data;
ret = sdi->driver->dev_acquisition_start(sdi, sdi);
if (ret != SR_OK) {
sr_err("Could not start %s device %s acquisition.",
sdi->driver->name, sdi->connection_id);
break;
}
}
if (ret != SR_OK) {
/* If there are multiple devices, some of them may already have
* started successfully. Stop them now before returning. */
lend = l->next;
for (l = session->devs; l != lend; l = l->next) {
sdi = l->data;
if (sdi->driver->dev_acquisition_stop)
sdi->driver->dev_acquisition_stop(sdi, sdi);
}
/* TODO: Handle delayed stops. Need to iterate the event
* sources... */
session->running = FALSE;
unset_main_context(session);
return ret;
}
if (g_hash_table_size(session->event_sources) == 0)
stop_check_later(session);
return SR_OK;
}
/**
* Start a session.
*
* @param session The session to use. Must not be NULL.
*
* @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;
struct sr_channel *ch;
GSList *l, *c;
int enabled_channels, 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;
ret = set_main_context(session);
if (ret != SR_OK)
return ret;
session->running = TRUE;
sr_info("Starting.");
for (l = session->devs; l; l = l->next) {
sdi = l->data;
enabled_channels = 0;
for (c = sdi->channels; c; c = c->next) {
ch = c->data;
if (ch->enabled) {
enabled_channels++;
break;
}
}
if (enabled_channels == 0) {
ret = SR_ERR;
sr_err("%s using connection %s has no enabled channels!",
sdi->driver->name, sdi->connection_id);
break;
}
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;
}
}
if (ret != SR_OK) {
unset_main_context(session);
session->running = FALSE;
}
/* TODO: What if there are multiple devices? Which return code? */
return ret;
}
