OpenCores
URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [gcc/] [ada/] [s-osprim-vms.ads] - Blame information for rev 706

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 706 jeremybenn
------------------------------------------------------------------------------
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
--                                  S p e c                                 --
8
--                                                                          --
9
--          Copyright (C) 1998-2009, 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 package provides low level primitives used to implement clock and
33
--  delays in non tasking applications on Alpha/VMS.
34
 
35
--  The choice of the real clock/delay implementation (depending on whether
36
--  tasking is involved or not) is done via soft links (see s-soflin.ads)
37
 
38
--  NEVER add any dependency to tasking packages here
39
 
40
package System.OS_Primitives is
41
   pragma Preelaborate;
42
 
43
   subtype OS_Time is Long_Integer;
44
   --  System time on VMS is used for performance reasons.
45
   --  Note that OS_Time is *not* the same as Ada.Calendar.Time, the
46
   --  difference being that relative OS_Time is negative, but relative
47
   --  Calendar.Time is positive.
48
   --  See Ada.Calendar.Delays for more information on VMS Time.
49
 
50
   Max_Sensible_Delay : constant Duration :=
51
                          Duration'Min (183 * 24 * 60 * 60.0,
52
                                        Duration'Last);
53
   --  Max of half a year delay, needed to prevent exceptions for large delay
54
   --  values. It seems unlikely that any test will notice this restriction,
55
   --  except in the case of applications setting the clock at run time (see
56
   --  s-tastim.adb). Also note that a larger value might cause problems (e.g
57
   --  overflow, or more likely OS limitation in the primitives used). In the
58
   --  case where half a year is too long (which occurs in high integrity mode
59
   --  with 32-bit words, and possibly on some specific ports of GNAT),
60
   --  Duration'Last is used instead.
61
 
62
   procedure Initialize;
63
   --  Initialize global settings related to this package. This procedure
64
   --  should be called before any other subprograms in this package. Note
65
   --  that this procedure can be called several times.
66
 
67
   function OS_Clock return OS_Time;
68
   --  Returns "absolute" time, represented as an offset
69
   --  relative to "the Epoch", which is Nov 17, 1858 on VMS.
70
 
71
   function Clock return Duration;
72
   pragma Inline (Clock);
73
   --  Returns "absolute" time, represented as an offset relative to "the
74
   --  Epoch", which is Jan 1, 1970 00:00:00 UTC on UNIX systems. This
75
   --  implementation is affected by system's clock changes.
76
 
77
   function Monotonic_Clock return Duration;
78
   pragma Inline (Monotonic_Clock);
79
   --  Returns "absolute" time, represented as an offset relative to "the Unix
80
   --  Epoch", which is Jan 1, 1970 00:00:00 UTC. This clock implementation is
81
   --  immune to the system's clock changes.
82
 
83
   Relative          : constant := 0;
84
   Absolute_Calendar : constant := 1;
85
   Absolute_RT       : constant := 2;
86
   --  Values for Mode call below. Note that the compiler (exp_ch9.adb) relies
87
   --  on these values. So any change here must be reflected in corresponding
88
   --  changes in the compiler.
89
 
90
   procedure Timed_Delay (Time : Duration; Mode : Integer);
91
   --  Implements the semantics of the delay statement when no tasking is used
92
   --  in the application.
93
   --
94
   --    Mode is one of the three values above
95
   --
96
   --    Time is a relative or absolute duration value, depending on Mode.
97
   --
98
   --  Note that currently Ada.Real_Time always uses the tasking run time,
99
   --  so this procedure should never be called with Mode set to Absolute_RT.
100
   --  This may change in future or bare board implementations.
101
 
102
   function To_Duration (T : OS_Time; Mode : Integer) return Duration;
103
   --  Convert VMS system time to Duration
104
   --  Mode is one of the three values above
105
 
106
   function To_OS_Time (D : Duration; Mode : Integer) return OS_Time;
107
   --  Convert Duration to VMS system time
108
   --  Mode is one of the three values above
109
 
110
end System.OS_Primitives;

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.