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------------------------------------------------------------------------------

--                                                                          --

--                  GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                --

--                                                                          --

--              S Y S T E M . T A S K I N G . U T I L I T I E S             --

--                                                                          --

--                                  S p e c                                 --

--                                                                          --

--         Copyright (C) 1992-2009, Free Software Foundation, Inc.          --

--                                                                          --

-- GNARL 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 3,  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.                                     --

--                                                                          --

-- As a special exception under Section 7 of GPL version 3, you are granted --

-- additional permissions described in the GCC Runtime Library Exception,   --

-- version 3.1, as published by the Free Software Foundation.               --

--                                                                          --

-- You should have received a copy of the GNU General Public License and    --

-- a copy of the GCC Runtime Library Exception along with this program;     --

-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --

-- <http://www.gnu.org/licenses/>.                                          --

--                                                                          --

-- GNARL was developed by the GNARL team at Florida State University.       --

-- Extensive contributions were provided by Ada Core Technologies, Inc.     --

--                                                                          --

------------------------------------------------------------------------------

--  This package provides RTS Internal Declarations.

--  These declarations are not part of the GNARLI

with Ada.Unchecked_Conversion;

with System.Task_Primitives;

package System.Tasking.Utilities is

   function ATCB_To_Address is new

     Ada.Unchecked_Conversion (Task_Id, System.Task_Primitives.Task_Address);

   ---------------------------------

   -- Task_Stage Related routines --

   ---------------------------------

   procedure Make_Independent;

   --  Move the current task to the outermost level (level 2) of the master

   --  hierarchy of the environment task. That is one level further out

   --  than normal tasks defined in library-level packages (level 3). The

   --  environment task will wait for level 3 tasks to terminate normally,

   --  then it will abort all the level 2 tasks. See Finalize_Global_Tasks

   --  procedure for more information.

   --

   --  This is a dangerous operation, and should never be used on nested tasks

   --  or tasks that depend on any objects that might be finalized earlier than

   --  the termination of the environment task. It is for internal use by the

   --  GNARL, to prevent such internal server tasks from preventing a partition

   --  from terminating.

   --

   --  Also note that the run time assumes that the parent of an independent

   --  task is the environment task. If this is not the case, Make_Independent

   --  will change the task's parent. This assumption is particularly

   --  important for master level completion and for the computation of

   --  Independent_Task_Count.

   Independent_Task_Count : Natural := 0;

   --  Number of independent task. This counter is incremented each time

   --  Make_Independent is called. Note that if a server task terminates,

   --  this counter will not be decremented. Since Make_Independent locks

   --  the environment task (because every independent task depends on it),

   --  this counter is protected by the environment task's lock.

   ---------------------------------

   -- Task Abort Related Routines --

   ---------------------------------

   procedure Cancel_Queued_Entry_Calls (T : Task_Id);

   --  Cancel any entry calls queued on target task.

   --  Call this while holding T's lock (or RTS_Lock in Single_Lock mode).

   procedure Exit_One_ATC_Level (Self_ID : Task_Id);

   pragma Inline (Exit_One_ATC_Level);

   --  Call only with abort deferred and holding lock of Self_ID.

   --  This is a bit of common code for all entry calls.

   --  The effect is to exit one level of ATC nesting.

   procedure Abort_One_Task (Self_ID : Task_Id; T : Task_Id);

   --  Similar to Locked_Abort_To_Level (Self_ID, T, 0), but:

   --    (1) caller should be holding no locks

   --    (2) may be called for tasks that have not yet been activated

   --    (3) always aborts whole task

   procedure Abort_Tasks (Tasks : Task_List);

   --  Abort_Tasks is called to initiate abort, however, the actual

   --  aborting is done by aborted task by means of Abort_Handler

   procedure Make_Passive (Self_ID : Task_Id; Task_Completed : Boolean);

   --  Update counts to indicate current task is either terminated or

   --  accepting on a terminate alternative. Call holding no locks except

   --  Global_Task_Lock when calling from Terminate_Task, and RTS_Lock when

   --  Single_Lock is True.

end System.Tasking.Utilities;