------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUN-TIME COMPONENTS                         --
--                                                                          --
--         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          --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2005 Free Software Foundation, Inc.          --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT;  see file COPYING.  If not, write --
-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
-- MA 02111-1307, USA.                                                      --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  does not  by itself cause  the resulting  executable  to  be --
-- covered  by the  GNU  General  Public  License.  This exception does not --
-- however invalidate  any other reasons why  the executable file  might be --
-- covered by the  GNU Public License.                                      --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

pragma Warnings (Off);
--  Allow withing of non-Preelaborated units in Ada 2005 mode where this
--  package will be categorized as Preelaborate. See AI-362 for details.
--  It is safe in the context of the run-time to violate the rules!

with System.Tasking;
--  Used for Detect_Blocking
--           Self

with Ada.Exceptions;
--  Used for Raise_Exception

with System.Task_Primitives.Operations;
--  Used for Initialize
--           Finalize
--           Current_State
--           Set_False
--           Set_True
--           Suspend_Until_True

pragma Warnings (On);

package body Ada.Synchronous_Task_Control is

   ----------------
   -- Initialize --
   ----------------

   procedure Initialize (S : in out Suspension_Object) is
   begin
      System.Task_Primitives.Operations.Initialize (S.SO);
   end Initialize;

   --------------
   -- Finalize --
   --------------

   procedure Finalize (S : in out Suspension_Object) is
   begin
      System.Task_Primitives.Operations.Finalize (S.SO);
   end Finalize;

   -------------------
   -- Current_State --
   -------------------

   function Current_State (S : Suspension_Object) return Boolean is
   begin
      return System.Task_Primitives.Operations.Current_State (S.SO);
   end Current_State;

   ---------------
   -- Set_False --
   ---------------

   procedure Set_False (S : in out Suspension_Object) is
   begin
      System.Task_Primitives.Operations.Set_False (S.SO);
   end Set_False;

   --------------
   -- Set_True --
   --------------

   procedure Set_True (S : in out Suspension_Object) is
   begin
      System.Task_Primitives.Operations.Set_True (S.SO);
   end Set_True;

   ------------------------
   -- Suspend_Until_True --
   ------------------------

   procedure Suspend_Until_True (S : in out Suspension_Object) is
   begin
      --  This is a potentially blocking (see ARM D.10, par. 10), so that
      --  if pragma Detect_Blocking is active then Program_Error must be
      --  raised if this operation is called from a protected action.

      if System.Tasking.Detect_Blocking
        and then System.Tasking.Self.Common.Protected_Action_Nesting > 0
      then
         Ada.Exceptions.Raise_Exception
           (Program_Error'Identity, "potentially blocking operation");
      end if;

      System.Task_Primitives.Operations.Suspend_Until_True (S.SO);
   end Suspend_Until_True;

end Ada.Synchronous_Task_Control;