1------------------------------------------------------------------------------
2--                                                                          --
3--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
4--                                                                          --
5--                   S Y S T E M . O S _ I N T E R F A C E                  --
6--                                                                          --
7--                                   B o d y                                --
8--                                                                          --
9--                     Copyright (C) 1995-2012, AdaCore                     --
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-- GNARL was developed by the GNARL team at Florida State University.       --
28-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  This is an Android version of this package.
33
34pragma Polling (Off);
35--  Turn off polling, we do not want ATC polling to take place during
36--  tasking operations. It causes infinite loops and other problems.
37
38--  This package encapsulates all direct interfaces to OS services
39--  that are needed by children of System.
40
41with Interfaces.C; use Interfaces.C;
42package body System.OS_Interface is
43
44   -----------------
45   -- To_Duration --
46   -----------------
47
48   function To_Duration (TS : timespec) return Duration is
49   begin
50      return Duration (TS.tv_sec) + Duration (TS.tv_nsec) / 10#1#E9;
51   end To_Duration;
52
53   -----------------
54   -- To_Timespec --
55   -----------------
56
57   function To_Timespec (D : Duration) return timespec is
58      S : time_t;
59      F : Duration;
60
61   begin
62      S := time_t (Long_Long_Integer (D));
63      F := D - Duration (S);
64
65      --  If F has negative value due to a round-up, adjust for positive F
66      --  value.
67
68      if F < 0.0 then
69         S := S - 1;
70         F := F + 1.0;
71      end if;
72
73      return timespec'(tv_sec => S,
74                       tv_nsec => long (Long_Long_Integer (F * 10#1#E9)));
75   end To_Timespec;
76
77   -------------------
78   -- clock_gettime --
79   -------------------
80
81   function clock_gettime
82     (clock_id : clockid_t;
83      tp       : access timespec) return int
84   is
85      pragma Unreferenced (clock_id);
86
87      --  Android/Linux don't have clock_gettime, so use gettimeofday
88
89      use Interfaces;
90
91      type timeval is array (1 .. 2) of C.long;
92
93      procedure timeval_to_duration
94        (T    : not null access timeval;
95         sec  : not null access C.long;
96         usec : not null access C.long);
97      pragma Import (C, timeval_to_duration, "__gnat_timeval_to_duration");
98
99      Micro  : constant := 10**6;
100      sec    : aliased C.long;
101      usec   : aliased C.long;
102      TV     : aliased timeval;
103      Result : int;
104
105      function gettimeofday
106        (Tv : access timeval;
107         Tz : System.Address := System.Null_Address) return int;
108      pragma Import (C, gettimeofday, "gettimeofday");
109
110   begin
111      Result := gettimeofday (TV'Access, System.Null_Address);
112      pragma Assert (Result = 0);
113      timeval_to_duration (TV'Access, sec'Access, usec'Access);
114      tp.all := To_Timespec (Duration (sec) + Duration (usec) / Micro);
115      return Result;
116   end clock_gettime;
117
118end System.OS_Interface;
119