class direct_acceptor :An implementation of?close_on_shutdown:bool -> ?preclose:unit -> unit -> Unix.file_descr -> Unixqueue.event_system ->server_endpoint_acceptor
server_endpoint_acceptor for sockets and Win32
named pipes. For sockets, the passed descriptor must be the master
socket. For Win32 named pipes, the passed descriptor must be the
proxy descriptor of the pipe server..