App Scheduler Max Event Size 4-byte Multiple

[juliantbrown]

We use the app scheduler in our app and I recently needed to increase the EVENT_SIZE passed into APP_SCHED_INIT. I changed it to a value that is not an event 4-byte multiple. This seemed to cause undefined behavior, including hard faults.

Is it required that this value is a 4-byte multiple or is this behavior unexpected? I couldn't find any documentation indicating that this is a requirement.

[Håkon Alseth]

Hi,

 

Is it required that this value is a 4-byte multiple or is this behavior unexpected?

Yes, I can confirm that it is a requirement that the input buffer is word-aligned. However; there's no mention of this in our documentation. I'll report this internally.

The only thing that can hint towards that requirement in our docs is the macro for initializing, as it rounds in word size: https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.3.0/group__app__scheduler.html#gaa9670ed0053a67304c3d2d0cb3eb1333

 

Thanks for reporting this back to us!

 

Kind regards,

Håkon