File : g-semaph.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT LIBRARY COMPONENTS --
4 -- --
5 -- G N A T . S E M A P H O R E S --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 2003-2010, AdaCore --
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 -- --
19 -- --
20 -- --
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 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
29 -- --
30 ------------------------------------------------------------------------------
31
32 package body GNAT.Semaphores is
33
34 ------------------------
35 -- Counting_Semaphore --
36 ------------------------
37
38 protected body Counting_Semaphore is
39
40 -----------
41 -- Seize --
42 -----------
43
44 entry Seize when Count > 0 is
45 begin
46 Count := Count - 1;
47 end Seize;
48
49 -------------
50 -- Release --
51 -------------
52
53 procedure Release is
54 begin
55 Count := Count + 1;
56 end Release;
57 end Counting_Semaphore;
58
59 ----------------------
60 -- Binary_Semaphore --
61 ----------------------
62
63 protected body Binary_Semaphore is
64
65 -----------
66 -- Seize --
67 -----------
68
69 entry Seize when Available is
70 begin
71 Available := False;
72 end Seize;
73
74 -------------
75 -- Release --
76 -------------
77
78 procedure Release is
79 begin
80 Available := True;
81 end Release;
82 end Binary_Semaphore;
83
84 end GNAT.Semaphores;