Thanks for the feedback! As the talk and the post both mentioned, I was focusing on signals that work on all Unix platforms. Within the constraints of a 30 minute talk there must be material left on the cutting room floor. (If I started talking about the specifics of various Unix lineages I could fill up a whole day...)

For most users in the real world, self-pipes are sufficient. This includes mio (Tokio's underlying library)'s portable Unix implementation of wakers (how parts of the system tell other parts to wake up).