------------------------------------------------------------------------------
--                                                                          --
--                 GNU ADA RUNTIME 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) 1991-2003 Free Software Foundation, Inc.          --
--                                                                          --
-- 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,  59 Temple Place - Suite 330,  Boston, --
-- MA 02111-1307, 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).                                  --
--                                                                          --
------------------------------------------------------------------------------

--  This is the FreeBSD THREADS version of this package

with Interfaces.C; use Interfaces.C;

package body System.OS_Interface is

   function Errno return int is
      type int_ptr is access all int;

      function internal_errno return int_ptr;
      pragma Import (C, internal_errno, "__error");
   begin
      return (internal_errno.all);
   end Errno;

   function Get_Stack_Base (thread : pthread_t) return Address is
      pragma Unreferenced (thread);
   begin
      return (0);
   end Get_Stack_Base;

   procedure pthread_init is
   begin
      null;
   end pthread_init;

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

   function To_Duration (TS : timespec) return Duration is
   begin
      return Duration (TS.ts_sec) + Duration (TS.ts_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 a round-up, adjust for positive F
      --  value.
      if F < 0.0 then S := S - 1; F := F + 1.0; end if;
      return timespec'(ts_sec => S,
        ts_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 : long;
      F : Duration;
   begin
      S := long (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 => long (Long_Long_Integer (F * 10#1#E6)));
   end To_Timeval;

end System.OS_Interface;