summaryrefslogtreecommitdiff
path: root/gcc/ada/a-caldel.adb
blob: ee9903a2558b91bb1b3dfaafd57195c7e7a5f1c4 (plain)
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
------------------------------------------------------------------------------
--                                                                          --
--                GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS               --
--                                                                          --
--                   A D A . C A L E N D A R . D E L A Y S                  --
--                                                                          --
--                                  B o d y                                 --
--                                                                          --
--             Copyright (C) 1991-2001 Florida State University             --
--                                                                          --
-- 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).                                  --
--                                                                          --
------------------------------------------------------------------------------

with System.OS_Primitives;
--  Used for Delay_Modes
--           Max_Sensible_Delay

with System.Soft_Links;
--  Used for Timed_Delay

with System.Traces;
--  Used for Send_Trace_Info

with System.Parameters;
--  used for Runtime_Traces

package body Ada.Calendar.Delays is

   package OSP renames System.OS_Primitives;
   package SSL renames System.Soft_Links;

   use type SSL.Timed_Delay_Call;

   use System.Traces;

   --  Earlier, the following operations were implemented using
   --  System.Time_Operations.  The idea was to avoid sucking in the tasking
   --  packages.  This did not work.  Logically, we can't have it both ways.
   --  There is no way to implement time delays that will have correct task
   --  semantics without reference to the tasking run-time system.
   --  To achieve this goal, we now use soft links.

   -----------------------
   -- Local Subprograms --
   -----------------------

   procedure Timed_Delay_NT (Time : Duration; Mode : Integer);
   --  Timed delay procedure used when no tasking is active

   ---------------
   -- Delay_For --
   ---------------

   procedure Delay_For (D : Duration) is
   begin
      if System.Parameters.Runtime_Traces then
         Send_Trace_Info (W_Delay, D);
      end if;

      SSL.Timed_Delay.all (Duration'Min (D, OSP.Max_Sensible_Delay),
                           OSP.Relative);

      if System.Parameters.Runtime_Traces then
         Send_Trace_Info (M_Delay, D);
      end if;
   end Delay_For;

   -----------------
   -- Delay_Until --
   -----------------

   procedure Delay_Until (T : Time) is
      D : constant Duration := To_Duration (T);

   begin
      if System.Parameters.Runtime_Traces then
         Send_Trace_Info (WU_Delay, D);
      end if;

      SSL.Timed_Delay.all (D, OSP.Absolute_Calendar);

      if System.Parameters.Runtime_Traces then
         Send_Trace_Info (M_Delay, D);
      end if;
   end Delay_Until;

   --------------------
   -- Timed_Delay_NT --
   --------------------

   procedure Timed_Delay_NT (Time : Duration; Mode : Integer) is
   begin
      OSP.Timed_Delay (Time, Mode);
   end Timed_Delay_NT;

   -----------------
   -- To_Duration --
   -----------------

   function To_Duration (T : Time) return Duration is
   begin
      return Duration (T);
   end To_Duration;

begin
   --  Set up the Timed_Delay soft link to the non tasking version
   --  if it has not been already set.

   --  If tasking is present, Timed_Delay has already set this soft
   --  link, or this will be overriden during the elaboration of
   --  System.Tasking.Initialization

   if SSL.Timed_Delay = null then
      SSL.Timed_Delay := Timed_Delay_NT'Access;
   end if;
end Ada.Calendar.Delays;