I found the "Unix signals" section of the 2010 LWN article "Ghosts of Unix past, part 3: Unfixable designs" by Neil Brown https://lwn.net/Articles/414618/ very interesting, though I don't know enough to recommend it firmly. (Previous HN discussions: https://news.ycombinator.com/item?id=27183784 on part 3, https://news.ycombinator.com/item?id=1941189 and https://news.ycombinator.com/item?id=1971106 on the whole series.)