At this point I believe ppoll has been added to every mainstream Unix except macOS. It's also been accepted for the next POSIX revision. For many years pselect

At this point I believe ppoll has been added to every mainstream Unix except macOS. It's also been accepted for the next POSIX revision. For many years pselect on macOS didn't actually fix the race condition, notwithstanding its UNIX03 certification. pselect was just a naive wrapper around select that didn't atomically unmask signals. So I ended up having to create a kqueue-based implementation for use on macOS and stragglers like OpenBSD which at that time lacked pselect entirely. See https://github.com/wahern/cqueues/blob/87f14f9/src/cqueues.c#L2489 https://github.com/wahern/cqueues/blob/87f14f9/src/cqueues.c... I can't remember if pselect has been fixed on macOS. The same approach could be used to emulate ppoll on macOS. Though epoll, kqueue, and Solaris ports are so similar that you can easily wrap all of them behind a thin shim. See https://github.com/wahern/cqueues/blob/87f14f9/src/lib/kpoll.c https://github.com/wahern/cqueues/blob/87f14f9/src/lib/kpoll... (Caution: it's an incomplete refactor of a similar shim I used in some non-open source code. The original code is even simpler and has seen extensive use. The refactored shim should work but is untested.) AIX is really the only mainstream Unix lacking an API w/ equivalent semantics. AIX has a better-than-poll interface, but it doesn't work anything like the others. Notably, epoll, kqueue, and Solaris ports control descriptors are all pollable in their own right, permitting you to nest different [readiness polling-based] event loop frameworks.