gcc/ada/a-sytaco.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUNTIME COMPONENTS                          --
   4 --                                                                          --
   5 --         A D A . S Y N C H R O N O U S _ T A S K _ C O N T R O L          --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --                            $Revision: 1.9 $
  10 --                                                                          --
  11 --            Copyright (C) 1992-2001 Free Software Foundation, Inc.        --
  12 --                                                                          --
  13 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  14 -- terms of the  GNU General Public License as published  by the Free Soft- --
  15 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  16 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  17 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  18 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  19 -- for  more details.  You should have  received  a copy of the GNU General --
  20 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  21 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  22 -- MA 02111-1307, USA.                                                      --
  23 --                                                                          --
  24 -- As a special exception,  if other files  instantiate  generics from this --
  25 -- unit, or you link  this unit with other files  to produce an executable, --
  26 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  27 -- covered  by the  GNU  General  Public  License.  This exception does not --
  28 -- however invalidate  any other reasons why  the executable file  might be --
  29 -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
  31 -- GNAT was originally developed  by the GNAT team at  New York University. --
  32 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  33 --                                                                          --
  34 ------------------------------------------------------------------------------
  35
  36
  37 package body Ada.Synchronous_Task_Control is
  38
  39    -------------------
  40    -- Suspension_PO --
  41    -------------------
  42
  43    protected body Suspension_Object is
  44
  45       --------------
  46       -- Get_Open --
  47       --------------
  48
  49       function Get_Open return Boolean is
  50       begin
  51          return Open;
  52       end Get_Open;
  53
  54       ---------------
  55       -- Set_False --
  56       ---------------
  57
  58       procedure Set_False is
  59       begin
  60          Open := False;
  61       end Set_False;
  62
  63       --------------
  64       -- Set_True --
  65       --------------
  66
  67       procedure Set_True is
  68       begin
  69          Open := True;
  70       end Set_True;
  71
  72       ----------
  73       -- Wait --
  74       ----------
  75
  76       entry Wait when Open is
  77       begin
  78          Open := False;
  79       end Wait;
  80
  81       --------------------
  82       -- Wait_Exception --
  83       --------------------
  84
  85       entry Wait_Exception when True is
  86       begin
  87          if Wait'Count /= 0 then
  88             raise Program_Error;
  89          end if;
  90
  91          requeue Wait;
  92       end Wait_Exception;
  93
  94    end Suspension_Object;
  95
  96    -------------------
  97    -- Current_State --
  98    -------------------
  99
 100    function Current_State (S : Suspension_Object) return Boolean is
 101    begin
 102       return S.Get_Open;
 103    end Current_State;
 104
 105    ---------------
 106    -- Set_False --
 107    ---------------
 108
 109    procedure Set_False (S : in out Suspension_Object) is
 110    begin
 111       S.Set_False;
 112    end Set_False;
 113
 114    --------------
 115    -- Set_True --
 116    --------------
 117
 118    procedure Set_True (S : in out Suspension_Object) is
 119    begin
 120       S.Set_True;
 121    end Set_True;
 122
 123    ------------------------
 124    -- Suspend_Until_True --
 125    ------------------------
 126
 127    procedure Suspend_Until_True (S : in out Suspension_Object) is
 128    begin
 129       S.Wait_Exception;
 130    end Suspend_Until_True;
 131
 132 end Ada.Synchronous_Task_Control;