| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT 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) 1995-2005, AdaCore -- |
| -- -- |
| -- 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, 51 Franklin Street, Fifth Floor, -- |
| -- Boston, MA 02110-1301, 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 |
| Dummy_Node : 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; |
| -- Set True for direct indices that are already used (True??? type???) |
| |
| 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, abort 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, abort must be deferred |
| -- and T.L must be write-locked. |
| |
| end System.Tasking.Task_Attributes; |
