What is the order in which File Descriptors in epoll are returned?

Question

Let\'s say I have set a set of file descriptors, say 8, 9, 10, 11, 12 in the order specified and do an epoll_wait() for data to be read on them.

epoll_wait returns w

Answer 1

Just think about it logically. Presumably they're not all marked as readable as a single atomic operation, and epoll_wait might then just as well just return 1 fd available each time it's called. It makes no sense to depend on the order of it's output.