(* wrapclock.def provides access to clock primitives.

Copyright (C) 2023-2024 Free Software Foundation, Inc.
Contributed by Gaius Mulley <gaiusmod2@gmail.com>.

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 wrapclock ;

FROM SYSTEM IMPORT ADDRESS ;

TYPE
   timespec = ADDRESS ;


(*
   timezone - return the glibc timezone value.
              This contains the difference between UTC and the latest
              local standard time, in seconds west of UTC.
              If the underlying timezone is unavailable and
              clock_gettime, localtime_r, tm_gmtoff
              is unavailable then 0 is returned.
*)

PROCEDURE timezone () : LONGINT ;


(*
   istimezone returns 1 if timezone in wrapclock.cc can resolve the
              timezone value using the timezone C library call or by using
              clock_gettime, localtime_r and tm_gmtoff.
*)

PROCEDURE istimezone () : INTEGER ;


(*
   daylight - return the glibc daylight value.
              This variable has a nonzero value if Daylight Saving
              Time rules apply.
              A nonzero value does not necessarily mean that Daylight
              Saving Time is now in effect; it means only that Daylight
              Saving Time is sometimes in effect.
*)

PROCEDURE daylight () : INTEGER ;


(*
   isdst - returns 1 if daylight saving time is currently in effect and
           returns 0 if it is not.
*)

PROCEDURE isdst () : INTEGER ;


(*
   tzname - returns the string associated with the local timezone.
            The daylight value is 0 or 1.  The value 0 returns the non
            daylight saving timezone string and the value of 1 returns
            the daylight saving timezone string.
*)

PROCEDURE tzname (daylight: INTEGER) : ADDRESS ;


(*
   InitTimespec - returns a newly created opaque type.
*)

PROCEDURE InitTimespec () : timespec ;


(*
   KillTimespec - deallocates the memory associated with an
                  opaque type.
*)

PROCEDURE KillTimespec (tv: timespec) : timespec ;


(*
   GetTimespec - retrieves the number of seconds and nanoseconds
                 from the timespec.  A return value of 0 means timespec
                 is unavailable and a return value of 1 indicates success.
*)

PROCEDURE GetTimespec (ts: timespec; VAR sec, nano: LONGCARD) : INTEGER ;


(*
   SetTimespec - sets the number of seconds and nanoseconds
                 into timespec.  A return value of 0 means timespec
                 is unavailable and a return value of 1 indicates success.
*)

PROCEDURE SetTimespec (ts: timespec; sec, nano: LONGCARD) : INTEGER ;


(*
   GetTimeRealtime - performs return gettime (CLOCK_REALTIME, ts).
                     gettime returns 0 on success and -1 on failure.
                     If the underlying system does not have gettime
                     then GetTimeRealtime returns 1.
*)

PROCEDURE GetTimeRealtime (ts: timespec) : INTEGER ;


(*
   SetTimeRealtime - performs return settime (CLOCK_REALTIME, ts).
                     gettime returns 0 on success and -1 on failure.
                     If the underlying system does not have gettime
                     then SetTimeRealtime returns 1.
*)

PROCEDURE SetTimeRealtime (ts: timespec) : INTEGER ;


END wrapclock.