gcc/ada/libgnarl/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) 2007-2018, 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 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.Tasking;
  38 with System.OS_Interface; use System.OS_Interface;
  39 with System.Task_Primitives.Operations; use System.Task_Primitives.Operations;
  40
  41 with Interfaces.C; use Interfaces.C;
  42
  43 package body Ada.Execution_Time is
  44
  45    pragma Linker_Options ("-lrt");
  46    --  POSIX.1b Realtime Extensions library. Needed to have access to function
  47    --  clock_gettime.
  48
  49    ---------
  50    -- "+" --
  51    ---------
  52
  53    function "+"
  54      (Left  : CPU_Time;
  55       Right : Ada.Real_Time.Time_Span) return CPU_Time
  56    is
  57       use type Ada.Real_Time.Time;
  58    begin
  59       return CPU_Time (Ada.Real_Time.Time (Left) + Right);
  60    end "+";
  61
  62    function "+"
  63      (Left  : Ada.Real_Time.Time_Span;
  64       Right : CPU_Time) return CPU_Time
  65    is
  66       use type Ada.Real_Time.Time;
  67    begin
  68       return CPU_Time (Left + Ada.Real_Time.Time (Right));
  69    end "+";
  70
  71    ---------
  72    -- "-" --
  73    ---------
  74
  75    function "-"
  76      (Left  : CPU_Time;
  77       Right : Ada.Real_Time.Time_Span) return CPU_Time
  78    is
  79       use type Ada.Real_Time.Time;
  80    begin
  81       return CPU_Time (Ada.Real_Time.Time (Left) - Right);
  82    end "-";
  83
  84    function "-"
  85      (Left  : CPU_Time;
  86       Right : CPU_Time) return Ada.Real_Time.Time_Span
  87    is
  88       use type Ada.Real_Time.Time;
  89    begin
  90       return (Ada.Real_Time.Time (Left) - Ada.Real_Time.Time (Right));
  91    end "-";
  92
  93    -----------
  94    -- Clock --
  95    -----------
  96
  97    function Clock
  98      (T : Ada.Task_Identification.Task_Id :=
  99         Ada.Task_Identification.Current_Task) return CPU_Time
 100    is
 101       TS       : aliased timespec;
 102       Clock_Id : aliased Interfaces.C.int;
 103       Result   : Interfaces.C.int;
 104
 105       function To_CPU_Time is
 106         new Ada.Unchecked_Conversion (Duration, CPU_Time);
 107       --  Time is equal to Duration (although it is a private type) and
 108       --  CPU_Time is equal to Time.
 109
 110       function Convert_Ids is new
 111         Ada.Unchecked_Conversion (Task_Id, System.Tasking.Task_Id);
 112
 113       function clock_gettime
 114         (clock_id : Interfaces.C.int;
 115          tp       : access timespec)
 116          return int;
 117       pragma Import (C, clock_gettime, "clock_gettime");
 118       --  Function from the POSIX.1b Realtime Extensions library
 119
 120       function pthread_getcpuclockid
 121         (tid       : Thread_Id;
 122          clock_id  : access Interfaces.C.int)
 123          return int;
 124       pragma Import (C, pthread_getcpuclockid, "pthread_getcpuclockid");
 125       --  Function from the Thread CPU-Time Clocks option
 126
 127    begin
 128       if T = Ada.Task_Identification.Null_Task_Id then
 129          raise Program_Error;
 130       else
 131          --  Get the CPU clock for the task passed as parameter
 132
 133          Result := pthread_getcpuclockid
 134            (Get_Thread_Id (Convert_Ids (T)), Clock_Id'Access);
 135          pragma Assert (Result = 0);
 136       end if;
 137
 138       Result := clock_gettime
 139         (clock_id => Clock_Id, tp => TS'Unchecked_Access);
 140       pragma Assert (Result = 0);
 141
 142       return To_CPU_Time (To_Duration (TS));
 143    end Clock;
 144
 145    --------------------------
 146    -- Clock_For_Interrupts --
 147    --------------------------
 148
 149    function Clock_For_Interrupts return CPU_Time is
 150    begin
 151       --  According to AI 0170-1, D.14(18.1/3), if Interrupt_Clocks_Supported
 152       --  is set to False the function raises Program_Error.
 153
 154       raise Program_Error;
 155       return CPU_Time_First;
 156    end Clock_For_Interrupts;
 157
 158    -----------
 159    -- Split --
 160    -----------
 161
 162    procedure Split
 163      (T  : CPU_Time;
 164       SC : out Ada.Real_Time.Seconds_Count;
 165       TS : out Ada.Real_Time.Time_Span)
 166    is
 167
 168    begin
 169       Ada.Real_Time.Split (Ada.Real_Time.Time (T), SC, TS);
 170    end Split;
 171
 172    -------------
 173    -- Time_Of --
 174    -------------
 175
 176    function Time_Of
 177      (SC : Ada.Real_Time.Seconds_Count;
 178       TS : Ada.Real_Time.Time_Span := Ada.Real_Time.Time_Span_Zero)
 179       return CPU_Time
 180    is
 181    begin
 182       return CPU_Time (Ada.Real_Time.Time_Of (SC, TS));
 183    end Time_Of;
 184
 185 end Ada.Execution_Time;