The way I'm implementing events using LiveData feels rather
unorthodox, but I'm not aware of anything in the Android framework
that would let me do it in a better way... One option I did
consider was wrapping the cheat lists in LiveData and observing
those, but then CheatsAdapter wouldn't know which cheat had
changed, only that there was some kind of change to the list,
necessitating the use of the not recommended notifyDataSetChanged.
This path isn't really any faster in the normal case,
but it does let us skip waiting for the lock to be available,
which makes a huge difference if the lock is already taken.
It seems like we spend a lot of the game list scanning time in
updateAdditionalMetadata, which I suppose makes sense considering
how many different files that function attempts to open.
With the addition of just one little atomic operation, we can make
it safe to call updateAdditionalMetadata without holding a lock.
FindAllGamePaths may take a little while, and holding the
gameFileCache lock isn't actually necessary until it's time to
put the results returned by FindAllGamePaths into gameFileCache.
The downside of this change is that we have to do an extra
round of JNI in between FindAllGamePaths and Update,
but I don't think that's much of a problem.