111
|
1 ------------------------------------------------------------------------------
|
|
2 -- --
|
|
3 -- GNAT RUN-TIME COMPONENTS --
|
|
4 -- --
|
|
5 -- S Y S T E M . A T O M I C _ C O U N T E R S --
|
|
6 -- --
|
|
7 -- B o d y --
|
|
8 -- --
|
|
9 -- Copyright (C) 2011-2017, Free Software Foundation, Inc. --
|
|
10 -- --
|
|
11 -- GNAT 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 -- GNAT was originally developed by the GNAT team at New York University. --
|
|
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
|
|
29 -- --
|
|
30 ------------------------------------------------------------------------------
|
|
31
|
|
32 -- This is version of the package, for use on platforms where this capability
|
|
33 -- is not supported. All Atomic_Counter operations raises Program_Error,
|
|
34 -- Atomic_Unsigned operations processed in non-atomic manner.
|
|
35
|
|
36 package body System.Atomic_Counters is
|
|
37
|
|
38 ---------------
|
|
39 -- Decrement --
|
|
40 ---------------
|
|
41
|
|
42 function Decrement (Item : in out Atomic_Counter) return Boolean is
|
|
43 begin
|
|
44 raise Program_Error;
|
|
45 return False;
|
|
46 end Decrement;
|
|
47
|
|
48 function Decrement (Item : aliased in out Atomic_Unsigned) return Boolean is
|
|
49 begin
|
|
50 -- Could not use Item := Item - 1; because it is disabled in spec.
|
|
51 Item := Atomic_Unsigned'Pred (Item);
|
|
52 return Item = 0;
|
|
53 end Decrement;
|
|
54
|
|
55 procedure Decrement (Item : aliased in out Atomic_Unsigned) is
|
|
56 begin
|
|
57 Item := Atomic_Unsigned'Pred (Item);
|
|
58 end Decrement;
|
|
59
|
|
60 ---------------
|
|
61 -- Increment --
|
|
62 ---------------
|
|
63
|
|
64 procedure Increment (Item : in out Atomic_Counter) is
|
|
65 begin
|
|
66 raise Program_Error;
|
|
67 end Increment;
|
|
68
|
|
69 procedure Increment (Item : aliased in out Atomic_Unsigned) is
|
|
70 begin
|
|
71 Item := Atomic_Unsigned'Succ (Item);
|
|
72 end Increment;
|
|
73
|
|
74 ----------------
|
|
75 -- Initialize --
|
|
76 ----------------
|
|
77
|
|
78 procedure Initialize (Item : out Atomic_Counter) is
|
|
79 begin
|
|
80 raise Program_Error;
|
|
81 end Initialize;
|
|
82
|
|
83 ------------
|
|
84 -- Is_One --
|
|
85 ------------
|
|
86
|
|
87 function Is_One (Item : Atomic_Counter) return Boolean is
|
|
88 begin
|
|
89 raise Program_Error;
|
|
90 return False;
|
|
91 end Is_One;
|
|
92
|
|
93 end System.Atomic_Counters;
|