gcc/ada/libgnarl/s-tasinf__linux.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                     S Y S T E M . T A S K _ I N F O                      --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --            Copyright (C) 2009-2018, Free Software Foundation, Inc.       --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 --  This is the GNU/Linux version of this module
  33
  34 package body System.Task_Info is
  35
  36    N_CPU : Natural := 0;
  37    pragma Atomic (N_CPU);
  38    --  Cache CPU number. Use pragma Atomic to avoid a race condition when
  39    --  setting N_CPU in Number_Of_Processors below.
  40
  41    --------------------------
  42    -- Number_Of_Processors --
  43    --------------------------
  44
  45    function Number_Of_Processors return Positive is
  46    begin
  47       if N_CPU = 0 then
  48          N_CPU := Natural
  49            (OS_Interface.sysconf (OS_Interface.SC_NPROCESSORS_ONLN));
  50       end if;
  51
  52       return N_CPU;
  53    end Number_Of_Processors;
  54
  55 end System.Task_Info;