(* Selective.def provides Modula-2 with access to the select(2) primitive.

Copyright (C) 2001-2025 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 Selective ;

FROM SYSTEM IMPORT ADDRESS ;

EXPORT QUALIFIED SetOfFd, Timeval,
                 InitSet, KillSet, InitTime, KillTime,
                 GetTime, SetTime,
                 FdZero, FdSet, FdClr, FdIsSet, Select,
                 MaxFdsPlusOne, WriteCharRaw, ReadCharRaw,
                 GetTimeOfDay ;

TYPE
   SetOfFd = ADDRESS ;    (* Hidden type in Selective.c *)
   Timeval = ADDRESS ;    (* Hidden type in Selective.c *)


PROCEDURE Select (nooffds: CARDINAL;
                  readfds, writefds, exceptfds: SetOfFd;
                  timeout: Timeval) : INTEGER ;

PROCEDURE InitTime (sec, usec: CARDINAL) : Timeval ;
PROCEDURE KillTime (t: Timeval) : Timeval ;
PROCEDURE GetTime (t: Timeval; VAR sec, usec: CARDINAL) ;
PROCEDURE SetTime (t: Timeval; sec, usec: CARDINAL) ;
PROCEDURE InitSet () : SetOfFd ;
PROCEDURE KillSet (s: SetOfFd) : SetOfFd ;
PROCEDURE FdZero (s: SetOfFd) ;
PROCEDURE FdSet (fd: INTEGER; s: SetOfFd) ;
PROCEDURE FdClr (fd: INTEGER; s: SetOfFd) ;
PROCEDURE FdIsSet (fd: INTEGER; s: SetOfFd) : BOOLEAN ;
PROCEDURE MaxFdsPlusOne (a, b: INTEGER) : INTEGER ;

(* you must use the raw routines with select - not the FIO buffered routines *)
PROCEDURE WriteCharRaw (fd: INTEGER; ch: CHAR) ;
PROCEDURE ReadCharRaw (fd: INTEGER) : CHAR ;

(*
   GetTimeOfDay - fills in a record, Timeval, filled in with the
                  current system time in seconds and microseconds.
                  It returns zero (see man 3p gettimeofday)
*)

PROCEDURE GetTimeOfDay (tv: Timeval) : INTEGER ;


END Selective.
