------------------------------------------------------------------------------
--                                                                          --
--                GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS               --
--                                                                          --
--                   S Y S T E M . O S _ I N T E R F A C E                  --
--                                                                          --
--                                  B o d y                                 --
--                                                                          --
--            Copyright (C) 1991-2002 Florida State University              --
--                                                                          --
-- GNARL is free software; you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
-- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNARL; see file COPYING.  If not, write --
-- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
-- Boston, MA 02110-1301, USA.                                              --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  does not  by itself cause  the resulting  executable  to  be --
-- covered  by the  GNU  General  Public  License.  This exception does not --
-- however invalidate  any other reasons why  the executable file  might be --
-- covered by the  GNU Public License.                                      --
--                                                                          --
-- GNARL was developed by the GNARL team at Florida State University. It is --
-- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
-- State University (http://www.gnat.com).                                  --
--                                                                          --
-- The GNARL files that were developed for RTEMS are maintained by  On-Line --
-- Applications Research Corporation (http://www.oarcorp.com)  in  coopera- --
-- tion with Ada Core Technologies Inc. and Florida State University.       --
--                                                                          --
------------------------------------------------------------------------------

--  This is the RTEMS version of this package

--  This package encapsulates all direct interfaces to OS services
--  that are needed by children of System.

pragma Polling (Off);
--  Turn off polling, we do not want ATC polling to take place during
--  tasking operations. It causes infinite loops and other problems.

with Interfaces.C; use Interfaces.C;
package body System.OS_Interface is

   -----------------
   -- To_Duration --
   -----------------

   function To_Duration (TS : timespec) return Duration is
   begin
      return Duration (TS.tv_sec) + Duration (TS.tv_nsec) / 10#1#E9;
   end To_Duration;

   -----------------
   -- To_Timespec --
   -----------------

   function To_Timespec (D : Duration) return timespec is
      S : time_t;
      F : Duration;
   begin
      S := time_t (Long_Long_Integer (D));
      F := D - Duration (S);

      --  If F has negative value due to round-up, adjust for positive F value

      if F < 0.0 then S := S - 1; F := F + 1.0; end if;
      return timespec'(tv_sec => S,
                       tv_nsec => long (Long_Long_Integer (F * 10#1#E9)));
   end To_Timespec;

   function To_Duration (TV : struct_timeval) return Duration is
   begin
      return Duration (TV.tv_sec) + Duration (TV.tv_usec) / 10#1#E6;
   end To_Duration;

   function To_Timeval (D : Duration) return struct_timeval is
      S : int;
      F : Duration;
   begin
      S := int (Long_Long_Integer (D));
      F := D - Duration (S);

      --  If F has negative value due to a round-up, adjust for positive F
      --  value.
      if F < 0.0 then S := S - 1; F := F + 1.0; end if;
      return
        struct_timeval'
          (tv_sec  => S,
           tv_usec => int (Long_Long_Integer (F * 10#1#E6)));
   end To_Timeval;

   procedure pthread_init is
   begin
      null;
   end pthread_init;

   function Get_Stack_Base (thread : pthread_t) return Address is
      pragma Warnings (Off, thread);

   begin
      return Null_Address;
   end Get_Stack_Base;

   function Get_Page_Size return size_t is
   begin
      return 0;
   end Get_Page_Size;

   function Get_Page_Size return Address is
   begin
      return 0;
   end Get_Page_Size;

end System.OS_Interface;
