1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . O S _ P R I M I T I V E S --
9 -- Copyright (C) 1998-2007, Free Software Foundation, Inc. --
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 2, or (at your option) any later ver- --
14 -- sion. GNARL 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. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNARL; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNARL was developed by the GNARL team at Florida State University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 -- This version uses gettimeofday and select
35 -- This file is suitable for OpenNT, Dec Unix and SCO UnixWare.
37 package body System.OS_Primitives is
39 -- ??? These definitions are duplicated from System.OS_Interface
40 -- because we don't want to depend on any package. Consider removing
41 -- these declarations in System.OS_Interface and move these ones in
44 type struct_timeval is record
48 pragma Convention (C, struct_timeval);
50 procedure gettimeofday
51 (tv : not null access struct_timeval;
52 tz : Address := Null_Address);
53 pragma Import (C, gettimeofday, "gettimeofday");
59 exceptfds : Address := Null_Address;
60 timeout : not null access struct_timeval);
61 pragma Import (C, C_select, "select");
67 function Clock return Duration is
68 TV : aliased struct_timeval;
71 gettimeofday (TV'Access);
72 return Duration (TV.tv_sec) + Duration (TV.tv_usec) / 10#1#E6;
79 function Monotonic_Clock return Duration renames Clock;
91 Base_Time : constant Duration := Clock;
92 Check_Time : Duration := Base_Time;
93 timeval : aliased struct_timeval;
96 if Mode = Relative then
98 Abs_Time := Time + Check_Time;
100 Rel_Time := Time - Check_Time;
104 if Rel_Time > 0.0 then
106 timeval.tv_sec := Integer (Rel_Time);
108 if Duration (timeval.tv_sec) > Rel_Time then
109 timeval.tv_sec := timeval.tv_sec - 1;
113 Integer ((Rel_Time - Duration (timeval.tv_sec)) * 10#1#E6);
115 C_select (timeout => timeval'Unchecked_Access);
118 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
120 Rel_Time := Abs_Time - Check_Time;
129 procedure Initialize is
134 end System.OS_Primitives;