INTERNAL! Atomically updates the int reference by calling updateIfTrue to get the new value. updateIfTrue returns a Tuple<should update, the new int value, the return value> If the first item in the tuple is true, the value is updated, and the third value of the tuple is returned. Note that updateIfTrue may be called many times so it should be idempotent.

INTERNAL! Atomically updates the object reference by calling updater to get the new value. Note that updater may be called many times so it should be idempotent.