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) 2007-2012, 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
34with Ada.Task_Identification;  use Ada.Task_Identification;
35with Ada.Unchecked_Conversion;
36
37with System.OS_Constants; use System.OS_Constants;
38with System.OS_Interface; use System.OS_Interface;
39
40with Interfaces.C; use Interfaces.C;
41
42package body Ada.Execution_Time is
43
44   pragma Linker_Options ("-lrt");
45   --  POSIX.1b Realtime Extensions library. Needed to have access to function
46   --  clock_gettime.
47
48   ---------
49   -- "+" --
50   ---------
51
52   function "+"
53     (Left  : CPU_Time;
54      Right : Ada.Real_Time.Time_Span) return CPU_Time
55   is
56      use type Ada.Real_Time.Time;
57   begin
58      return CPU_Time (Ada.Real_Time.Time (Left) + Right);
59   end "+";
60
61   function "+"
62     (Left  : Ada.Real_Time.Time_Span;
63      Right : CPU_Time) return CPU_Time
64   is
65      use type Ada.Real_Time.Time;
66   begin
67      return CPU_Time (Left + Ada.Real_Time.Time (Right));
68   end "+";
69
70   ---------
71   -- "-" --
72   ---------
73
74   function "-"
75     (Left  : CPU_Time;
76      Right : Ada.Real_Time.Time_Span) return CPU_Time
77   is
78      use type Ada.Real_Time.Time;
79   begin
80      return CPU_Time (Ada.Real_Time.Time (Left) - Right);
81   end "-";
82
83   function "-"
84     (Left  : CPU_Time;
85      Right : CPU_Time) return Ada.Real_Time.Time_Span
86   is
87      use type Ada.Real_Time.Time;
88   begin
89      return (Ada.Real_Time.Time (Left) - Ada.Real_Time.Time (Right));
90   end "-";
91
92   -----------
93   -- Clock --
94   -----------
95
96   function Clock
97     (T : Ada.Task_Identification.Task_Id :=
98        Ada.Task_Identification.Current_Task) 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   begin
116      if T = Ada.Task_Identification.Null_Task_Id then
117         raise Program_Error;
118      end if;
119
120      Result := clock_gettime
121        (clock_id => CLOCK_THREAD_CPUTIME_ID, tp => TS'Unchecked_Access);
122      pragma Assert (Result = 0);
123
124      return To_CPU_Time (To_Duration (TS));
125   end Clock;
126
127   --------------------------
128   -- Clock_For_Interrupts --
129   --------------------------
130
131   function Clock_For_Interrupts return CPU_Time is
132   begin
133      --  According to AI 0170-1, D.14(18.1/3), if Interrupt_Clocks_Supported
134      --  is set to False the function raises Program_Error.
135
136      raise Program_Error;
137      return CPU_Time_First;
138   end Clock_For_Interrupts;
139
140   -----------
141   -- Split --
142   -----------
143
144   procedure Split
145     (T  : CPU_Time;
146      SC : out Ada.Real_Time.Seconds_Count;
147      TS : out Ada.Real_Time.Time_Span)
148   is
149      use type Ada.Real_Time.Time;
150   begin
151      Ada.Real_Time.Split (Ada.Real_Time.Time (T), SC, TS);
152   end Split;
153
154   -------------
155   -- Time_Of --
156   -------------
157
158   function Time_Of
159     (SC : Ada.Real_Time.Seconds_Count;
160      TS : Ada.Real_Time.Time_Span := Ada.Real_Time.Time_Span_Zero)
161      return CPU_Time
162   is
163   begin
164      return CPU_Time (Ada.Real_Time.Time_Of (SC, TS));
165   end Time_Of;
166
167end Ada.Execution_Time;
168