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------------------------------------------------------------------------------
-- --
-- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . T A S K I N G . T A S K _ A T T R I B U T E S --
-- --
-- S p e c --
-- --
-- Copyright (C) 1991-1994, Florida State University --
-- Copyright (C) 1995-2004, Ada Core Technologies --
-- --
-- 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 2, or (at your option) any later ver- --
-- sion. GNARL 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 GNARL; 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. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. --
-- Extensive contributions were provided by Ada Core Technologies, Inc. --
-- --
------------------------------------------------------------------------------
-- This package provides support for the body of Ada.Task_Attributes.
with Ada.Finalization;
-- used for Limited_Controlled
with System.Storage_Elements;
-- used for Integer_Address
package System.Tasking.Task_Attributes is
type Attribute is new Integer;
-- A stand-in for the generic formal type of Ada.Task_Attributes
-- in the following declarations.
type Node;
type Access_Node is access all Node;
-- This needs comments ???
function To_Access_Node is new Unchecked_Conversion
(Access_Address, Access_Node);
-- Used to fetch pointer to indirect attribute list. Declaration is
-- in spec to avoid any problems with aliasing assumptions.
type Dummy_Wrapper;
type Access_Dummy_Wrapper is access all Dummy_Wrapper;
pragma No_Strict_Aliasing (Access_Dummy_Wrapper);
-- Needed to avoid possible incorrect aliasing situations from
-- instantiation of Unchecked_Conversion in body of Ada.Task_Attributes.
for Access_Dummy_Wrapper'Storage_Size use 0;
-- Access_Dummy_Wrapper is a stand-in for the generic type Wrapper defined
-- in Ada.Task_Attributes. The real objects allocated are always
-- of type Wrapper, no Dummy_Wrapper objects are ever created.
type Deallocator is access procedure (P : in out Access_Node);
-- Called to deallocate an Wrapper. P is a pointer to a Node within.
type Instance;
type Access_Instance is access all Instance;
type Instance is new Ada.Finalization.Limited_Controlled with record
Deallocate : Deallocator;
Initial_Value : aliased System.Storage_Elements.Integer_Address;
Index : Direct_Index;
-- The index of the TCB location used by this instantiation,
-- if it is stored in the TCB, otherwise zero.
Next : Access_Instance;
-- Next instance in All_Attributes list.
end record;
procedure Finalize (X : in out Instance);
type Node is record
Wrapper : Access_Dummy_Wrapper;
Instance : Access_Instance;
Next : Access_Node;
end record;
-- The following type is a stand-in for the actual
-- wrapper type, which is different for each instantiation
-- of Ada.Task_Attributes.
type Dummy_Wrapper is record
Noed : aliased Node;
Value : aliased Attribute;
-- The generic formal type, may be controlled
end record;
for Dummy_Wrapper'Alignment use Standard'Maximum_Alignment;
-- A number of unchecked conversions involving Dummy_Wrapper_Access
-- sources are performed in other units (e.g. Ada.Task_Attributes).
-- Ensure that the designated object is always strictly enough aligned.
In_Use : Direct_Index_Vector := 0;
-- is True for direct indices that are already used.
All_Attributes : Access_Instance;
-- A linked list of all indirectly access attributes,
-- which includes all those that require finalization.
procedure Initialize_Attributes (T : Task_Id);
-- Initialize all attributes created via Ada.Task_Attributes for T.
-- This must be called by the creator of the task, inside Create_Task,
-- via soft-link Initialize_Attributes_Link. On entry, abortion must
-- be deferred and the caller must hold no locks
procedure Finalize_Attributes (T : Task_Id);
-- Finalize all attributes created via Ada.Task_Attributes for T.
-- This is to be called by the task after it is marked as terminated
-- (and before it actually dies), inside Vulnerable_Free_Task, via the
-- soft-link Finalize_Attributes_Link. On entry, abortion must be deferred
-- and T.L must be write-locked.
end System.Tasking.Task_Attributes;
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