important bugfix

I checked all 5 cases for overflows when checking
for missed deadlines (there is current time, timeToWake
and lastWakeTime, with various combinations of overflows)

This should be the correct implementation now
This commit is contained in:
Robin Müller 2020-07-29 20:02:04 +02:00
parent c16675f69a
commit 652c60c362
2 changed files with 18 additions and 20 deletions

View File

@ -125,19 +125,18 @@ void FixedTimeslotTask::checkMissedDeadline(const TickType_t xLastWakeTime,
* it. */
TickType_t currentTickCount = xTaskGetTickCount();
TickType_t timeToWake = xLastWakeTime + interval;
// Tick count has overflown
if(currentTickCount < xLastWakeTime) {
// Time to wake has overflown as well. If the tick count
// is larger than the time to wake, a deadline was missed.
if(timeToWake < xLastWakeTime and
currentTickCount > timeToWake) {
// Time to wake has not overflown.
if(timeToWake > xLastWakeTime) {
/* If the current time has overflown exclusively or the current
* tick count is simply larger than the time to wake, a deadline was
* missed */
if((currentTickCount < xLastWakeTime) or (currentTickCount > timeToWake)) {
handleMissedDeadline();
}
}
// No tick count overflow. If the timeToWake has not overflown
// and the current tick count is larger than the time to wake,
// a deadline was missed.
else if(timeToWake > xLastWakeTime and currentTickCount > timeToWake) {
/* Time to wake has overflown. A deadline was missed if the current time
* is larger than the time to wake */
else if((timeToWake < xLastWakeTime) and (currentTickCount > timeToWake)) {
handleMissedDeadline();
}
}

View File

@ -108,19 +108,18 @@ void PeriodicTask::checkMissedDeadline(const TickType_t xLastWakeTime,
* it. */
TickType_t currentTickCount = xTaskGetTickCount();
TickType_t timeToWake = xLastWakeTime + interval;
// Tick count has overflown
if(currentTickCount < xLastWakeTime) {
// Time to wake has overflown as well. If the tick count
// is larger than the time to wake, a deadline was missed.
if(timeToWake < xLastWakeTime and
currentTickCount > timeToWake) {
// Time to wake has not overflown.
if(timeToWake > xLastWakeTime) {
/* If the current time has overflown exclusively or the current
* tick count is simply larger than the time to wake, a deadline was
* missed */
if((currentTickCount < xLastWakeTime) or (currentTickCount > timeToWake)) {
handleMissedDeadline();
}
}
// No tick count overflow. If the timeToWake has not overflown
// and the current tick count is larger than the time to wake,
// a deadline was missed.
else if(timeToWake > xLastWakeTime and currentTickCount > timeToWake) {
/* Time to wake has overflown. A deadline was missed if the current time
* is larger than the time to wake */
else if((timeToWake < xLastWakeTime) and (currentTickCount > timeToWake)) {
handleMissedDeadline();
}
}