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-- 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-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
29--                                                                          --
30------------------------------------------------------------------------------
31
32package 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
84end GNAT.Semaphores;
85