1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
------------------------------------------------------------------------------
-- --
-- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . O S _ P R I M I T I V E S --
-- --
-- B o d y --
-- --
-- $Revision: 1.8 $
-- --
-- Copyright (C) 1998-2001 Free Software Foundation, Inc. --
-- --
-- GNARL is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNARL; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. It is --
-- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
-- State University (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
-- This version uses gettimeofday and select
-- Currently OpenNT, Dec Unix, Solaris and SCO UnixWare use this file.
package body System.OS_Primitives is
-- ??? These definitions are duplicated from System.OS_Interface
-- because we don't want to depend on any package. Consider removing
-- these declarations in System.OS_Interface and move these ones in
-- the spec.
type struct_timezone is record
tz_minuteswest : Integer;
tz_dsttime : Integer;
end record;
pragma Convention (C, struct_timezone);
type struct_timezone_ptr is access all struct_timezone;
type struct_timeval is record
tv_sec : Integer;
tv_usec : Integer;
end record;
pragma Convention (C, struct_timeval);
function gettimeofday
(tv : access struct_timeval;
tz : struct_timezone_ptr) return Integer;
pragma Import (C, gettimeofday, "gettimeofday");
type fd_set is null record;
type fd_set_ptr is access all fd_set;
function C_select
(n : Integer := 0;
readfds,
writefds,
exceptfds : fd_set_ptr := null;
timeout : access struct_timeval) return Integer;
pragma Import (C, C_select, "select");
-----------
-- Clock --
-----------
function Clock return Duration is
TV : aliased struct_timeval;
Result : Integer;
begin
Result := gettimeofday (TV'Access, null);
return Duration (TV.tv_sec) + Duration (TV.tv_usec) / 10#1#E6;
end Clock;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration renames Clock;
-----------------
-- Timed_Delay --
-----------------
procedure Timed_Delay
(Time : Duration;
Mode : Integer)
is
Result : Integer;
Rel_Time : Duration;
Abs_Time : Duration;
Check_Time : Duration := Clock;
timeval : aliased struct_timeval;
begin
if Mode = Relative then
Rel_Time := Time;
Abs_Time := Time + Check_Time;
else
Rel_Time := Time - Check_Time;
Abs_Time := Time;
end if;
if Rel_Time > 0.0 then
loop
timeval.tv_sec := Integer (Rel_Time);
if Duration (timeval.tv_sec) > Rel_Time then
timeval.tv_sec := timeval.tv_sec - 1;
end if;
timeval.tv_usec :=
Integer ((Rel_Time - Duration (timeval.tv_sec)) * 10#1#E6);
Result := C_select (timeout => timeval'Unchecked_Access);
Check_Time := Clock;
exit when Abs_Time <= Check_Time;
Rel_Time := Abs_Time - Check_Time;
end loop;
end if;
end Timed_Delay;
end System.OS_Primitives;
|
