-(* The in descriptor is always open. Thanks to the broken semantics of
- * fifo outputs, the out descriptor must be opened a nouveau whenever we
- * want to send out data, and so we keep the associated filename as well.
- * Same with input fifos. Yipee.*)
-
-let add_fd (evpair:fd_and_fname) (fd_other:fd_and_fname) (callback:fd_and_fname->fd_and_fname->unit) =