ev_io_start
ev_io_start (EV_A_ &pipe_w);
ev_io_start (EV_A_ &sigfd_w);
ev_io_start (EV_A_ &fs_w);
ev_io_start (EV_A_ &fs_w);
ev_io_start (EV_A_ &w->io);
ev_io_start (EV_A_ &once->io);
EV_API_DECL void ev_io_start (EV_P_ ev_io *w) EV_THROW;
ev_io_start(ctx, (ev_io*) evpriv);
ev_io_start(ctx, (ev_io*) evpriv);