File : a-caldel.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
4 -- --
5 -- A D A . C A L E N D A R . D E L A Y S --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1991-1994, Florida State University --
10 -- Copyright (C) 1995-2010, AdaCore --
11 -- --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 3, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- --
23 -- You should have received a copy of the GNU General Public License and --
24 -- a copy of the GCC Runtime Library Exception along with this program; --
25 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
26 -- <http://www.gnu.org/licenses/>. --
27 -- --
28 -- GNARL was developed by the GNARL team at Florida State University. --
29 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
30 -- --
31 ------------------------------------------------------------------------------
32
33 with System.OS_Primitives;
34 with System.Soft_Links;
35 with System.Traces;
36 with System.Parameters;
37
38 package body Ada.Calendar.Delays is
39
40 package OSP renames System.OS_Primitives;
41 package SSL renames System.Soft_Links;
42
43 use type SSL.Timed_Delay_Call;
44
45 use System.Traces;
46
47 -- Earlier, System.Time_Operations was used to implement the following
48 -- operations. The idea was to avoid sucking in the tasking packages. This
49 -- did not work. Logically, we can't have it both ways. There is no way to
50 -- implement time delays that will have correct task semantics without
51 -- reference to the tasking run-time system. To achieve this goal, we now
52 -- use soft links.
53
54 -----------------------
55 -- Local Subprograms --
56 -----------------------
57
58 procedure Timed_Delay_NT (Time : Duration; Mode : Integer);
59 -- Timed delay procedure used when no tasking is active
60
61 ---------------
62 -- Delay_For --
63 ---------------
64
65 procedure Delay_For (D : Duration) is
66 begin
67 if System.Parameters.Runtime_Traces then
68 Send_Trace_Info (W_Delay, D);
69 end if;
70
71 SSL.Timed_Delay.all (Duration'Min (D, OSP.Max_Sensible_Delay),
72 OSP.Relative);
73
74 if System.Parameters.Runtime_Traces then
75 Send_Trace_Info (M_Delay, D);
76 end if;
77 end Delay_For;
78
79 -----------------
80 -- Delay_Until --
81 -----------------
82
83 procedure Delay_Until (T : Time) is
84 D : constant Duration := To_Duration (T);
85
86 begin
87 if System.Parameters.Runtime_Traces then
88 Send_Trace_Info (WU_Delay, D);
89 end if;
90
91 SSL.Timed_Delay.all (D, OSP.Absolute_Calendar);
92
93 if System.Parameters.Runtime_Traces then
94 Send_Trace_Info (M_Delay, D);
95 end if;
96 end Delay_Until;
97
98 --------------------
99 -- Timed_Delay_NT --
100 --------------------
101
102 procedure Timed_Delay_NT (Time : Duration; Mode : Integer) is
103 begin
104 OSP.Timed_Delay (Time, Mode);
105 end Timed_Delay_NT;
106
107 -----------------
108 -- To_Duration --
109 -----------------
110
111 function To_Duration (T : Time) return Duration is
112 begin
113 -- Since time has multiple representations on different platforms, a
114 -- target independent operation in Ada.Calendar is used to perform
115 -- this conversion.
116
117 return Delay_Operations.To_Duration (T);
118 end To_Duration;
119
120 begin
121 -- Set up the Timed_Delay soft link to the non tasking version if it has
122 -- not been already set. If tasking is present, Timed_Delay has already set
123 -- this soft link, or this will be overridden during the elaboration of
124 -- System.Tasking.Initialization
125
126 if SSL.Timed_Delay = null then
127 SSL.Timed_Delay := Timed_Delay_NT'Access;
128 end if;
129
130 end Ada.Calendar.Delays;