1------------------------------------------------------------------------------
2--                                                                          --
3--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
4--                                                                          --
5--                  S Y S T E M . O S _ P R I M I T I V E S                 --
6--                                                                          --
7--                                  B o d y                                 --
8--                                                                          --
9--          Copyright (C) 1998-2021, Free Software Foundation, Inc.         --
10--                                                                          --
11-- GNARL 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 version is for POSIX-like operating systems
33with System.Parameters;
34
35package body System.OS_Primitives is
36
37   --  ??? These definitions are duplicated from System.OS_Interface
38   --  because we don't want to depend on any package. Consider removing
39   --  these declarations in System.OS_Interface and move these ones in
40   --  the spec.
41
42   type time_t is range -2 ** (System.Parameters.time_t_bits - 1)
43     .. 2 ** (System.Parameters.time_t_bits - 1) - 1;
44
45   type timespec is record
46      tv_sec  : time_t;
47      tv_nsec : Long_Integer;
48   end record;
49   pragma Convention (C, timespec);
50
51   function nanosleep (rqtp, rmtp : not null access timespec) return Integer;
52   pragma Import (C, nanosleep, "nanosleep");
53
54   -----------
55   -- Clock --
56   -----------
57
58   function Clock return Duration is
59
60      type timeval is array (1 .. 3) of Long_Integer;
61      --  The timeval array is sized to contain Long_Long_Integer sec and
62      --  Long_Integer usec. If Long_Long_Integer'Size = Long_Integer'Size then
63      --  it will be overly large but that will not effect the implementation
64      --  since it is not accessed directly.
65
66      procedure timeval_to_duration
67        (T    : not null access timeval;
68         sec  : not null access Long_Long_Integer;
69         usec : not null access Long_Integer);
70      pragma Import (C, timeval_to_duration, "__gnat_timeval_to_duration");
71
72      Micro  : constant := 10**6;
73      sec    : aliased Long_Long_Integer;
74      usec   : aliased Long_Integer;
75      TV     : aliased timeval;
76      Result : Integer;
77      pragma Unreferenced (Result);
78
79      function gettimeofday
80        (Tv : access timeval;
81         Tz : System.Address := System.Null_Address) return Integer;
82      pragma Import (C, gettimeofday, "gettimeofday");
83
84   begin
85      --  The return codes for gettimeofday are as follows (from man pages):
86      --    EPERM  settimeofday is called by someone other than the superuser
87      --    EINVAL Timezone (or something else) is invalid
88      --    EFAULT One of tv or tz pointed outside accessible address space
89
90      --  None of these codes signal a potential clock skew, hence the return
91      --  value is never checked.
92
93      Result := gettimeofday (TV'Access, System.Null_Address);
94      timeval_to_duration (TV'Access, sec'Access, usec'Access);
95      return Duration (sec) + Duration (usec) / Micro;
96   end Clock;
97
98   -----------------
99   -- To_Timespec --
100   -----------------
101
102   function To_Timespec (D : Duration) return timespec;
103
104   function To_Timespec (D : Duration) return timespec is
105      S : time_t;
106      F : Duration;
107
108   begin
109      S := time_t (Long_Long_Integer (D));
110      F := D - Duration (S);
111
112      --  If F has negative value due to a round-up, adjust for positive F
113      --  value.
114
115      if F < 0.0 then
116         S := S - 1;
117         F := F + 1.0;
118      end if;
119
120      return
121        timespec'(tv_sec  => S,
122                  tv_nsec => Long_Integer (Long_Long_Integer (F * 10#1#E9)));
123   end To_Timespec;
124
125   -----------------
126   -- Timed_Delay --
127   -----------------
128
129   procedure Timed_Delay
130     (Time : Duration;
131      Mode : Integer)
132   is separate;
133
134   ----------------
135   -- Initialize --
136   ----------------
137
138   procedure Initialize is
139   begin
140      null;
141   end Initialize;
142
143end System.OS_Primitives;
144