static void alarmCallback(uint32_t, void*)
{
std::unique_lock<priority_recursive_mutex> sync(notifierMutex);
int32_t status = 0;
uint64_t currentTime = 0;
// the hardware disables itself after each alarm
closestTrigger = UINT64_MAX;
// process all notifiers
Notifier *notifier = notifiers;
while (notifier) {
if (notifier->triggerTime != UINT64_MAX) {
if (currentTime == 0)
currentTime = getFPGATime(&status);
if (notifier->triggerTime < currentTime) {
notifier->triggerTime = UINT64_MAX;
auto process = notifier->process;
auto param = notifier->param;
sync.unlock();
process(currentTime, param);
sync.lock();
} else if (notifier->triggerTime < closestTrigger) {
updateNotifierAlarm(notifier, notifier->triggerTime, &status);
}
}
notifier = notifier->next;
}
}
/**
* Update the alarm hardware to reflect the current first element in the queue.
* Compute the time the next alarm should occur based on the current time and the
* period for the first element in the timer queue.
* WARNING: this method does not do synchronization! It must be called from somewhere
* that is taking care of synchronizing access to the queue.
*/
void Notifier::UpdateAlarm()
{
if (timerQueueHead != NULL)
{
int32_t status = 0;
updateNotifierAlarm(m_notifier, (uint32_t)(timerQueueHead->m_expirationTime * 1e6), &status);
wpi_setStaticErrorWithContext(timerQueueHead, status, getHALErrorMessage(status));
}
}
/**
* Update the alarm hardware to reflect the current first element in the queue.
* Compute the time the next alarm should occur based on the current time and
* the
* period for the first element in the timer queue.
* WARNING: this method does not do synchronization! It must be called from
* somewhere
* that is taking care of synchronizing access to the queue.
*/
void Notifier::UpdateAlarm() {
if (timerQueueHead != nullptr) {
int32_t status = 0;
// This locking is necessary in order to avoid two things:
// 1) Race condition issues with calling cleanNotifer() and
// updateNotifierAlarm() at the same time.
// 2) Avoid deadlock by making it so that this won't block waiting
// for the mutex to unlock.
// Checking refcount as well is unnecessary, but will not hurt.
if (halMutex.try_lock() && refcount != 0) {
if (m_notifier)
updateNotifierAlarm(m_notifier,
(uint32_t)(timerQueueHead->m_expirationTime * 1e6),
&status);
halMutex.unlock();
}
wpi_setStaticErrorWithContext(timerQueueHead, status,
getHALErrorMessage(status));
}
}
