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