workavia-mail-front/docs/adr/0043-fix-memory-leak-with-controller-dispose.md

43. Fix memory leak with Controller's dispose()

Date: 2024-04-05

Status

• Issues:
  • Memory footprint #2533

Context

• Majority, if not all, of TMail's Controller are created by extending BaseController. Everytime a new state arrives, viewState, of BaseController is assigned with new value. This value is never disposed so its reference lives on even if the Controller itself dies that causes memory leak.

Decision

• A new state with name UIClosedState was created for clarification. It extends BaseUIState which extends UIState.
• viewState will be assigned to UIClosedState() inside the dispose() method of the memory-leaking controller, so the reference to its previous value is destroyed.
• Ideally, this value reasignment of viewState should happen inside BaseController's dispose(). However, current state of project is not allowed for side effect that can be caused by app wide changes. This can change in the future.

Consequences

• SingleEmailController & ComposerController's memory leak problem are resolved.