> OK, then maybe socket objects should get a dup() method that just
increments the ref counter, and that would be the public API you're looking
for?

"dup()" returns a new socket object, but here we only want to protect the original one.

Maybe just 'sock.inc_io_ref()' and 'sock.dec_io_ref()'?  OTOH using the current private socket API in asyncio and uvloop doesn't really scare me as long as it works, so keeping the status quo is also OK.