bool
uORB::DeviceNode::appears_updated(SubscriberData *sd)
{
/* block if in simulation mode */
while (px4_sim_delay_enabled()) {
usleep(100);
}
//warnx("uORB::DeviceNode::appears_updated sd = %p", sd);
/* assume it doesn't look updated */
bool ret = false;
/* check if this topic has been published yet, if not bail out */
if (_data == nullptr) {
return false;
}
/*
* If the subscriber's generation count matches the update generation
* count, there has been no update from their perspective; if they
* don't match then we might have a visible update.
*/
while (sd->generation != _generation) {
/*
* Handle non-rate-limited subscribers.
*/
if (sd->update_interval == 0) {
ret = true;
break;
}
/*
* If we have previously told the subscriber that there is data,
* and they have not yet collected it, continue to tell them
* that there has been an update. This mimics the non-rate-limited
* behaviour where checking / polling continues to report an update
* until the topic is read.
*/
if (sd->update_reported) {
ret = true;
break;
}
// If we have not yet reached the deadline, then assume that we can ignore any
// newly received data.
if (sd->last_update + sd->update_interval > hrt_absolute_time()) {
break;
}
/*
* Remember that we have told the subscriber that there is data.
*/
sd->update_reported = true;
sd->last_update = hrt_absolute_time();
ret = true;
break;
}
return ret;
}
bool
uORB::DeviceNode::appears_updated(SubscriberData *sd)
{
/* block if in simulation mode */
while (px4_sim_delay_enabled()) {
usleep(100);
}
//warnx("uORB::DeviceNode::appears_updated sd = %p", sd);
/* assume it doesn't look updated */
bool ret = false;
/* check if this topic has been published yet, if not bail out */
if (_data == nullptr) {
ret = false;
goto out;
}
/*
* If the subscriber's generation count matches the update generation
* count, there has been no update from their perspective; if they
* don't match then we might have a visible update.
*/
while (sd->generation != _generation) {
/*
* Handle non-rate-limited subscribers.
*/
if (sd->update_interval == 0) {
ret = true;
break;
}
/*
* If we have previously told the subscriber that there is data,
* and they have not yet collected it, continue to tell them
* that there has been an update. This mimics the non-rate-limited
* behaviour where checking / polling continues to report an update
* until the topic is read.
*/
if (sd->update_reported) {
ret = true;
break;
}
/*
* If the interval timer is still running, the topic should not
* appear updated, even though at this point we know that it has.
* We have previously been through here, so the subscriber
* must have collected the update we reported, otherwise
* update_reported would still be true.
*/
if (!hrt_called(&sd->update_call)) {
break;
}
/*
* Make sure that we don't consider the topic to be updated again
* until the interval has passed once more by restarting the interval
* timer and thereby re-scheduling a poll notification at that time.
*/
hrt_call_after(&sd->update_call,
sd->update_interval,
&uORB::DeviceNode::update_deferred_trampoline,
(void *)this);
/*
* Remember that we have told the subscriber that there is data.
*/
sd->update_reported = true;
ret = true;
break;
}
out:
/* consider it updated */
return ret;
}
