Update ActionService and ThingActions classes in Xtext cache

[wborn]

Xtext uses a cache for looking up classes when rules are run.
It also adds a null class value to this cache when a class is not found.

Once a value has entered the cache it will not be updated.
This causes the cache to return the wrong class (or the null value) when
calling static methods on ActionService and ThingActions classes that
were added/updated.

With the changes in this PR Xtext will be configured to use a custom cache
that updates the ActionService and ThingActions class references.

The PR also has a fix for the AnnotatedThingActionModuleTypeProvider not
properly sending ModuleType removed events when all ThingActions
registrations have been removed.

Fixes #1265
Fixes #1694

[kaikreuzer]

Wow, looks like pure magic and I do not claim to understand all details what you did there and even less how you have figure out to do it - but the result is fantastic 🎉 .

[cweitkamp]

@wborn Thanks again for this implementation. But I am afraid is is not the final solution. I still see an exception when updating a binding manually in the addons/ folder:

2020-10-30 12:04:52.830 [ERROR] [internal.handler.ScriptActionHandler] - Script execution of rule with UID 'b5c106f5b5' failed: class org.openhab.binding.pushover.internal.actions.PushoverActions cannot be cast to class org.openhab.binding.pushover.internal.actions.PushoverActions (org.openhab.binding.pushover.internal.actions.PushoverActions is in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @1979a84; org.openhab.binding.pushover.internal.actions.PushoverActions is in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @610f03)

[wborn]

I think there is still one other issue unrelated to this cache. I've also sometimes seen that if you would install a binding the ThingActions service registration is sometimes not created. As a result it would then also not be available when creating a rule using the UI.

So when that occurs the cache entry is probably also not updated. You can enable debug logging on org.openhab.core.model.rule.scoping.RulesClassCache to see if the ServiceRegistration for the binding ThingActions is created and causes the cache entry to be updated.

[cweitkamp]

I removed the *.jar file and moved a new one into my addons/ folder. I got the updated message - but still the same error:

2020-10-30 14:20:58.280 [DEBUG] [e.model.rule.scoping.RulesClassCache] - Updated cache entry: org.openhab.binding.pushover.internal.actions.PushoverActions
...
2020-10-30 14:21:04.675 [ERROR] [internal.handler.ScriptActionHandler] - Script execution of rule with UID 'b5c106f5b5' failed: class org.openhab.binding.pushover.internal.actions.PushoverActions cannot be cast to class org.openhab.binding.pushover.internal.actions.PushoverActions (org.openhab.binding.pushover.internal.actions.PushoverActions is in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @b20289; org.openhab.binding.pushover.internal.actions.PushoverActions is in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @1666cf7)

[wborn]

Are you using DSL rules or some other scripting language?

[cweitkamp]

These test were done with DSL rules. Created via UI.

[openhab-bot]

This pull request has been mentioned on openHAB Community. There might be relevant details there:

https://community.openhab.org/t/tr-064-thing-action-phonebooklookup-not-working/113101/38