Fix MongoState.delete(Boolean)

[leonjoosse]

MongoState did not override AbstractState.destroy(Boolean). In AbstractState.destroy(Boolean) is the variable 'service' used, which is/can become null. The MongoState class uses primarily the 'provider' variable. This caused agents to be deleted from the InstantiationService, but not from the database.

Note: this should maybe be fixed in another way by calling getService() instead of using the 'provider' variable?

[ludost]

Hi Leon,
I don't really understand what this change fixes? Both provider and getService() lead to the same object and the same delete() method within that object. So, your change doesn't change anything?

[leonjoosse]

Because AbstractState#delete(Boolean) uses the AbstractState#service directly. It doesn't call getService().
https://github.com/almende/eve-java/blob/master/states/eve_state/src/main/java/com/almende/eve/state/AbstractState.java#L288

[ludost]

That's exactly my point: AbstractState#service is pointing to the same object as MongoState@provider. As long as the pointer is not set to null (which the current code never does), your code doesn't change anything. So, my question remains: what are your trying to fix? What are the symptomes?

[leonjoosse]

I also expected to happen what you day, but when stepping through the test with a debugger, AbstractState#service is null, while MongoState#provider is not null. I'll get back to you on how to reproduce it.

[ludost]

I noticed that MongoState also overrides setService(), setting the provider field, but not updating the parent object. This will lead to inconsistencies when the service is set later than during construction. Best to cleanup MongoState to directly use AbstractState#getService() instead of a local copy.