------------------------------------------------------------------------------
--                                                                          --
--                           GPR PROJECT MANAGER                            --
--                                                                          --
--                       Copyright (C) 2022, AdaCore                        --
--                                                                          --
-- This library is free software;  you can redistribute it and/or modify it --
-- under terms of the  GNU General Public License  as published by the Free --
-- Software  Foundation;  either version 3,  or (at your  option) any later --
-- version. This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY;  without even the implied warranty of MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE.                            --
--                                                                          --
-- As a special exception 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/>.                                          --
--                                                                          --
------------------------------------------------------------------------------

pragma Warnings (Off, "is an internal GNAT unit");
with GNAT.Sockets.Thin_Common;
pragma Warnings (On, "is an internal GNAT unit");

separate (GPR.Util)
procedure Put_Resource_Usage (Filename : String) is
   package STC renames GNAT.Sockets.Thin_Common;

   type Rusage is record
      ru_utime    : STC.Timeval;  -- user time used
      ru_stime    : STC.Timeval;  -- system time used
      ru_maxrss   : Long_Integer; -- maximum resident set size
      ru_ixrss    : Long_Integer; -- integral shared memory size
      ru_idrss    : Long_Integer; -- integral unshared data size
      ru_isrss    : Long_Integer; -- integral unshared stack size
      ru_minflt   : Long_Integer; -- page reclaims
      ru_majflt   : Long_Integer; -- page faults
      ru_nswap    : Long_Integer; -- swaps
      ru_inblock  : Long_Integer; -- block input operations
      ru_oublock  : Long_Integer; -- block output operations
      ru_msgsnd   : Long_Integer; -- messages sent
      ru_msgrcv   : Long_Integer; -- messages received
      ru_nsignals : Long_Integer; -- signals received
      ru_nvcsw    : Long_Integer; -- voluntary context switches
      ru_nivcsw   : Long_Integer; -- involuntary context switches
   end record with Convention => C;

   Log : File_Type;

   RUSAGE_SELF     : constant := 0;
   RUSAGE_CHILDREN : constant := -1;
   RUSAGE_THREAD   : constant := 1;

   procedure Print (Who : Integer);

   -----------
   -- Print --
   -----------

   procedure Print (Who : Integer) is
      Usage : Rusage;
      Longs : array (1 .. 14) of Long_Integer
        with Import, Convention => C, Address => Usage.ru_maxrss'Address;

      procedure Print (This : STC.Timeval);

      function Getrusage (Who : Integer; usage : out Rusage) return Integer
        with Import, Convention => C;

      -----------
      -- Print --
      -----------

      procedure Print (This : STC.Timeval) is

         function No_1st_Space (S : String) return String is
           (if S /= "" and then S (S'First) = ' '
            then S (S'First + 1 .. S'Last) else S);

         Uimg : constant String := No_1st_Space (This.Tv_Usec'Img);
      begin
         Put (Log, This.Tv_Sec'Img);
         Put (Log, '.');
         if Uimg'Length < 6 then
            Put (Log, (1 .. 6 - Uimg'Length => '0'));
         end if;
         Put (Log, Uimg);
      end Print;

   begin
      if Getrusage (Who, Usage) /= 0 then
         Put_Line (Log, "error: " & GNAT.OS_Lib.Errno_Message);
         return;
      end if;

      Print (Usage.ru_utime);
      Print (Usage.ru_stime);

      for L of Longs loop
         Put (Log, L'Img);
      end loop;

      New_Line (Log);

      pragma Assert (Longs (Longs'Last)'Address = Usage.ru_nivcsw'Address);
   end Print;

begin
   Create (Log, Out_File, Filename);

   Print (RUSAGE_THREAD);
   Print (RUSAGE_SELF);
   Print (RUSAGE_CHILDREN);

   Close (Log);
end Put_Resource_Usage;
