gcc/ada/a-exetim-posix.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                   A D A . E X E C U T I O N _ T I M E                    --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --         Copyright (C) 2007-2011, 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 POSIX (Realtime Extension) version of this package
  33
  34 with Ada.Task_Identification;  use Ada.Task_Identification;
  35 with Ada.Unchecked_Conversion;
  36
  37 with System.OS_Interface; use System.OS_Interface;
  38
  39 with Interfaces.C; use Interfaces.C;
  40
  41 package body Ada.Execution_Time is
  42
  43    pragma Linker_Options ("-lrt");
  44    --  POSIX.1b Realtime Extensions library. Needed to have access to function
  45    --  clock_gettime.
  46
  47    ---------
  48    -- "+" --
  49    ---------
  50
  51    function "+"
  52      (Left  : CPU_Time;
  53       Right : Ada.Real_Time.Time_Span) return CPU_Time
  54    is
  55       use type Ada.Real_Time.Time;
  56    begin
  57       return CPU_Time (Ada.Real_Time.Time (Left) + Right);
  58    end "+";
  59
  60    function "+"
  61      (Left  : Ada.Real_Time.Time_Span;
  62       Right : CPU_Time) return CPU_Time
  63    is
  64       use type Ada.Real_Time.Time;
  65    begin
  66       return CPU_Time (Left + Ada.Real_Time.Time (Right));
  67    end "+";
  68
  69    ---------
  70    -- "-" --
  71    ---------
  72
  73    function "-"
  74      (Left  : CPU_Time;
  75       Right : Ada.Real_Time.Time_Span) return CPU_Time
  76    is
  77       use type Ada.Real_Time.Time;
  78    begin
  79       return CPU_Time (Ada.Real_Time.Time (Left) - Right);
  80    end "-";
  81
  82    function "-"
  83      (Left  : CPU_Time;
  84       Right : CPU_Time) return Ada.Real_Time.Time_Span
  85    is
  86       use type Ada.Real_Time.Time;
  87    begin
  88       return (Ada.Real_Time.Time (Left) - Ada.Real_Time.Time (Right));
  89    end "-";
  90
  91    -----------
  92    -- Clock --
  93    -----------
  94
  95    function Clock
  96      (T : Ada.Task_Identification.Task_Id :=
  97             Ada.Task_Identification.Current_Task)
  98       return CPU_Time
  99    is
 100       TS     : aliased timespec;
 101       Result : Interfaces.C.int;
 102
 103       function To_CPU_Time is
 104         new Ada.Unchecked_Conversion (Duration, CPU_Time);
 105       --  Time is equal to Duration (although it is a private type) and
 106       --  CPU_Time is equal to Time.
 107
 108       function clock_gettime
 109         (clock_id : Interfaces.C.int;
 110          tp       : access timespec)
 111          return int;
 112       pragma Import (C, clock_gettime, "clock_gettime");
 113       --  Function from the POSIX.1b Realtime Extensions library
 114
 115       CLOCK_THREAD_CPUTIME_ID : constant := 3;
 116       --  Identifier for the clock returning per-task CPU time
 117
 118    begin
 119       if T = Ada.Task_Identification.Null_Task_Id then
 120          raise Program_Error;
 121       end if;
 122
 123       Result := clock_gettime
 124         (clock_id => CLOCK_THREAD_CPUTIME_ID, tp => TS'Unchecked_Access);
 125       pragma Assert (Result = 0);
 126
 127       return To_CPU_Time (To_Duration (TS));
 128    end Clock;
 129
 130    --------------------------
 131    -- Clock_For_Interrupts --
 132    --------------------------
 133
 134    function Clock_For_Interrupts return CPU_Time is
 135    begin
 136       --  According to AI 0170-1, D.14(18.1/3), if Interrupt_Clocks_Supported
 137       --  is set to False the function raises Program_Error.
 138
 139       raise Program_Error;
 140       return CPU_Time_First;
 141    end Clock_For_Interrupts;
 142
 143    -----------
 144    -- Split --
 145    -----------
 146
 147    procedure Split
 148      (T  : CPU_Time;
 149       SC : out Ada.Real_Time.Seconds_Count;
 150       TS : out Ada.Real_Time.Time_Span)
 151    is
 152       use type Ada.Real_Time.Time;
 153    begin
 154       Ada.Real_Time.Split (Ada.Real_Time.Time (T), SC, TS);
 155    end Split;
 156
 157    -------------
 158    -- Time_Of --
 159    -------------
 160
 161    function Time_Of
 162      (SC : Ada.Real_Time.Seconds_Count;
 163       TS : Ada.Real_Time.Time_Span := Ada.Real_Time.Time_Span_Zero)
 164       return CPU_Time
 165    is
 166    begin
 167       return CPU_Time (Ada.Real_Time.Time_Of (SC, TS));
 168    end Time_Of;
 169
 170 end Ada.Execution_Time;