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) 2013-2015, 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 Linux/x32
33
34package body System.OS_Primitives is
35
36   --  ??? These definitions are duplicated from System.OS_Interface
37   --  because we don't want to depend on any package. Consider removing
38   --  these declarations in System.OS_Interface and move these ones in
39   --  the spec.
40
41   type time_t is new Long_Long_Integer;
42
43   type timespec is record
44      tv_sec  : time_t;
45      tv_nsec : Long_Long_Integer;
46   end record;
47   pragma Convention (C, timespec);
48
49   function nanosleep (rqtp, rmtp : not null access timespec) return Integer;
50   pragma Import (C, nanosleep, "nanosleep");
51
52   -----------
53   -- Clock --
54   -----------
55
56   function Clock return Duration is
57      type timeval is array (1 .. 2) of Long_Long_Integer;
58
59      procedure timeval_to_duration
60        (T    : not null access timeval;
61         sec  : not null access Long_Integer;
62         usec : not null access Long_Integer);
63      pragma Import (C, timeval_to_duration, "__gnat_timeval_to_duration");
64
65      Micro  : constant := 10**6;
66      sec    : aliased Long_Integer;
67      usec   : aliased Long_Integer;
68      TV     : aliased timeval;
69      Result : Integer;
70      pragma Unreferenced (Result);
71
72      function gettimeofday
73        (Tv : access timeval;
74         Tz : System.Address := System.Null_Address) return Integer;
75      pragma Import (C, gettimeofday, "gettimeofday");
76
77   begin
78      --  The return codes for gettimeofday are as follows (from man pages):
79      --    EPERM  settimeofday is called by someone other than the superuser
80      --    EINVAL Timezone (or something else) is invalid
81      --    EFAULT One of tv or tz pointed outside accessible address space
82
83      --  None of these codes signal a potential clock skew, hence the return
84      --  value is never checked.
85
86      Result := gettimeofday (TV'Access, System.Null_Address);
87      timeval_to_duration (TV'Access, sec'Access, usec'Access);
88      return Duration (sec) + Duration (usec) / Micro;
89   end Clock;
90
91   -----------------
92   -- To_Timespec --
93   -----------------
94
95   function To_Timespec (D : Duration) return timespec;
96
97   function To_Timespec (D : Duration) return timespec is
98      S : time_t;
99      F : Duration;
100
101   begin
102      S := time_t (Long_Long_Integer (D));
103      F := D - Duration (S);
104
105      --  If F has negative value due to a round-up, adjust for positive F
106      --  value.
107
108      if F < 0.0 then
109         S := S - 1;
110         F := F + 1.0;
111      end if;
112
113      return
114        timespec'(tv_sec  => S,
115                  tv_nsec => Long_Long_Integer (F * 10#1#E9));
116   end To_Timespec;
117
118   -----------------
119   -- Timed_Delay --
120   -----------------
121
122   procedure Timed_Delay
123     (Time : Duration;
124      Mode : Integer)
125   is
126      Request    : aliased timespec;
127      Remaind    : aliased timespec;
128      Rel_Time   : Duration;
129      Abs_Time   : Duration;
130      Base_Time  : constant Duration := Clock;
131      Check_Time : Duration := Base_Time;
132
133      Result : Integer;
134      pragma Unreferenced (Result);
135
136   begin
137      if Mode = Relative then
138         Rel_Time := Time;
139         Abs_Time := Time + Check_Time;
140      else
141         Rel_Time := Time - Check_Time;
142         Abs_Time := Time;
143      end if;
144
145      if Rel_Time > 0.0 then
146         loop
147            Request := To_Timespec (Rel_Time);
148            Result := nanosleep (Request'Access, Remaind'Access);
149            Check_Time := Clock;
150
151            exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
152
153            Rel_Time := Abs_Time - Check_Time;
154         end loop;
155      end if;
156   end Timed_Delay;
157
158   ----------------
159   -- Initialize --
160   ----------------
161
162   procedure Initialize is
163   begin
164      null;
165   end Initialize;
166
167end System.OS_Primitives;
168