- This commit adds a `Disposable` to `LLFirSession` which lives as long
as the session. For example, session components can now open a message
bus connection that is automatically disposed after the session has
been invalidated or reclaimed.
- Because `LLFirSession`s should still benefit from soft reference-based
automatic reclamation by the GC, we have to use a soft value map with
cleanup in `LLFirSessionCache`. It ensures that the child disposables
are properly disposed even when the session is collected as a soft
value.
- The session cannot be the `Disposable` itself because a valid
disposable reference is needed to call `Disposer.dispose`. When a soft
reference is added to a reference queue (such as the reference queue
employed by the soft value map), its referent is already cleared.
Hence, it's not possible to watch a softly referenced `Disposable`
with a reference queue and also pass it to `Disposer.dispose`. This is
why the `LLFirSessionCleaner` contains a strong reference to the
`disposable`, because that will not keep the `LLFirSession` from being
reclaimed, while keeping the `disposable` alive slightly longer than
the session.
^KT-61222
Marco Pennekamp
efb56ed30a