Comment by kcexn

poll is the POSIX specified I/O multiplexer so it has the advantage of being portable. Windows even supports a version of poll called WSAPoll.

If you must implement your own event loop and you want your application to be portable, poll is still a good place to begin.

O(N) demultiplexing time in the pollfd array is also not as brutal as it seems on modern hardware. The pollfd structure itself is only 8 bytes wide, so you can comfortably pack thousands of them into the L1 cache. Copying all of the elements that have an active event into a new smaller array before processing them is going to be fast enough for most cases.