Unsubscribe callback handlers when updating a module

[carllocos]

When updating a module, we should unsubscribe the callback handlers and this also means that for a MCU we should unsubscribe the service routine.

However, I believe that this may not even be necessary. The reason is that normally when we would update a module. The module should be persisted on the MCU so to survive potential reboots (I already opened an issue for this #121). If we persist a module and we decide to reboot the device, then the ISR get automatically unsubscribed. Meaning that this issue becomes irrelevant. However, I believe as long as we do not have the persisting feature yet, we should manually unsubscribe the ISRs.

What do you think @tolauwae?

[tolauwae]

I agree. The callback system should definitely be reset completely when a new module gets loaded. Except for the event queue imo.

For the persistant module. When that feature is implemented, I still wouldn't reboot the device on a module update because that is pretty slow. So I would still reset the callback system manually on module update.

[carllocos]

Actually, the decision of rebooting or not is dependent on the use case and should come from the developers. As of that, both options should be possible.

[tolauwae]

Actually, the decision of rebooting or not is dependent on the use case and should come from the developers. As of that, both options should be possible.

@carllocos With the new issue system I'm going through the old issue backlog. For the reboot after module update, there are already a two debug operations that can help with this: halt and reset. imo this give developers enough control over this decision.

I added the callback reset as a subissue (bug fix) and might have time to work on it soon.

[carllocos]

cool! I was not aware of halt and reset.

For now, unsubscribing the callbacks (without reboot) is not a priority and if needed could easily be solved imo.

Thanks for keeping it as a subissue.