Post #4382166

fun Linux fact: Using epoll, you can see from userspace when the in-kernel garbage collector for unix domain sockets is cleaning up unreachable reference loops formed by SCM_RIGHTS. epoll essentially holds weak pointers on watched files (no refcounted reference, instead epoll gets a hook call when the refcount drops to 0); and /proc/self/fdinfo/{epoll fd} shows which files are currently watched by epoll, with files automatically disappearing when their refcount drops to 0.