I don't know why NON_POLLING isn't default (@bmagyar thoughts? My only guess is that when it was written in 2013, it required boost and was therefore "heavier"?), but from #43 it looks like it currently doesn't build anyways. Perhaps once it's fixed we should investigate enabling it by default, at least in Noetic.
_Originally posted by @matthew-reynolds in https://github.com/ros-controls/realtime_tools/issues/50#issuecomment-586715858_