gcc/ada/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) 2003-2005, 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 2,  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.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 package body GNAT.Semaphores is
  35
  36    ------------------------
  37    -- Counting_Semaphore --
  38    ------------------------
  39
  40    protected body Counting_Semaphore is
  41
  42       -----------
  43       -- Seize --
  44       -----------
  45
  46       entry Seize when Count > 0 is
  47       begin
  48          Count := Count - 1;
  49       end Seize;
  50
  51       -------------
  52       -- Release --
  53       -------------
  54
  55       procedure Release is
  56       begin
  57          Count := Count + 1;
  58       end Release;
  59    end Counting_Semaphore;
  60
  61    ----------------------
  62    -- Binary_Semaphore --
  63    ----------------------
  64
  65    protected body Binary_Semaphore is
  66
  67       -----------
  68       -- Seize --
  69       -----------
  70
  71       entry Seize when Available is
  72       begin
  73          Available := False;
  74       end Seize;
  75
  76       -------------
  77       -- Release --
  78       -------------
  79
  80       procedure Release is
  81       begin
  82          Available := True;
  83       end Release;
  84    end Binary_Semaphore;
  85
  86 end GNAT.Semaphores;