It's also a fairly trivial thing to implement with flee system locks (just make sure your fs had sane semantics). In fact, with a bit of cleverness and fs locks you can implement more complex patterns trivially as well such as a pseudo daemon that is both cycled (without appreciable downtime) regularly as well as having a backup process to take over on failure.

Obviously, you don't run your webserver that way (right!?) but it's not nuts to manage (even near real-time) queue consumers in a backend that way.