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 --            Copyright (C) 1992-2001 Free Software Foundation, Inc.        --
  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,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, 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 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34
  35 package body Ada.Synchronous_Task_Control is
  36
  37    -------------------
  38    -- Suspension_PO --
  39    -------------------
  40
  41    protected body Suspension_Object is
  42
  43       --------------
  44       -- Get_Open --
  45       --------------
  46
  47       function Get_Open return Boolean is
  48       begin
  49          return Open;
  50       end Get_Open;
  51
  52       ---------------
  53       -- Set_False --
  54       ---------------
  55
  56       procedure Set_False is
  57       begin
  58          Open := False;
  59       end Set_False;
  60
  61       --------------
  62       -- Set_True --
  63       --------------
  64
  65       procedure Set_True is
  66       begin
  67          Open := True;
  68       end Set_True;
  69
  70       ----------
  71       -- Wait --
  72       ----------
  73
  74       entry Wait when Open is
  75       begin
  76          Open := False;
  77       end Wait;
  78
  79       --------------------
  80       -- Wait_Exception --
  81       --------------------
  82
  83       entry Wait_Exception when True is
  84       begin
  85          if Wait'Count /= 0 then
  86             raise Program_Error;
  87          end if;
  88
  89          requeue Wait;
  90       end Wait_Exception;
  91
  92    end Suspension_Object;
  93
  94    -------------------
  95    -- Current_State --
  96    -------------------
  97
  98    function Current_State (S : Suspension_Object) return Boolean is
  99    begin
 100       return S.Get_Open;
 101    end Current_State;
 102
 103    ---------------
 104    -- Set_False --
 105    ---------------
 106
 107    procedure Set_False (S : in out Suspension_Object) is
 108    begin
 109       S.Set_False;
 110    end Set_False;
 111
 112    --------------
 113    -- Set_True --
 114    --------------
 115
 116    procedure Set_True (S : in out Suspension_Object) is
 117    begin
 118       S.Set_True;
 119    end Set_True;
 120
 121    ------------------------
 122    -- Suspend_Until_True --
 123    ------------------------
 124
 125    procedure Suspend_Until_True (S : in out Suspension_Object) is
 126    begin
 127       S.Wait_Exception;
 128    end Suspend_Until_True;
 129
 130 end Ada.Synchronous_Task_Control;