(* RTio.def provides low level routines for creating and destroying ChanIds.

Copyright (C) 2008-2023 Free Software Foundation, Inc.
Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.

This file is part of GNU Modula-2.

GNU Modula-2 is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.

GNU Modula-2 is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  *)

DEFINITION MODULE RTio ;

(*
    Title      : RTio
    Author     : Gaius Mulley
    System     : GNU Modula-2
    Date       : Sun Sep  7 16:32:48 2008
    Revision   : $Version$ 
    Description: provides low level routines for creating and destroying
                 ChanIds.  This is necessary to allow multiple modules
                 to create, ChanId values, where ChanId is an opaque
                 type.
*)

IMPORT FIO, IOLink ;

TYPE
   ChanId ;


(*
   InitChanId - return a new ChanId.
*)

PROCEDURE InitChanId () : ChanId ;


(*
   KillChanId - deallocate a ChanId.
*)

PROCEDURE KillChanId (c: ChanId) : ChanId ;


(*
   NilChanId - return a NIL pointer.
*)

PROCEDURE NilChanId () : ChanId ;


(*
   GetDeviceId - returns the device id, from, c.
*)

PROCEDURE GetDeviceId (c: ChanId) : IOLink.DeviceId ;


(*
   SetDeviceId - sets the device id in, c.
*)

PROCEDURE SetDeviceId (c: ChanId; d: IOLink.DeviceId) ;


(*
   GetDevicePtr - returns the device table ptr, from, c.
*)

PROCEDURE GetDevicePtr (c: ChanId) : IOLink.DeviceTablePtr ;


(*
   SetDevicePtr - sets the device table ptr in, c.
*)

PROCEDURE SetDevicePtr (c: ChanId; p: IOLink.DeviceTablePtr) ;


(*
   GetFile - returns the file field from, c.
*)

PROCEDURE GetFile (c: ChanId) : FIO.File ;


(*
   SetFile - sets the file field in, c.
*)

PROCEDURE SetFile (c: ChanId; f: FIO.File) ;


END RTio.