1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--                  A D A . T A S K _ A T T R I B U T E S                   --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--            Copyright (C) 2014-2018, Free Software Foundation, Inc.       --
10--                                                                          --
11-- This specification is derived from the Ada Reference Manual for use with --
12-- GNAT. The copyright notice above, and the license provisions that follow --
13-- apply solely to the  contents of the part following the private keyword. --
14--                                                                          --
15-- GNAT is free software;  you can  redistribute it  and/or modify it under --
16-- terms of the  GNU General Public License as published  by the Free Soft- --
17-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
18-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
19-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
20-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
21--                                                                          --
22-- As a special exception under Section 7 of GPL version 3, you are granted --
23-- additional permissions described in the GCC Runtime Library Exception,   --
24-- version 3.1, as published by the Free Software Foundation.               --
25--                                                                          --
26-- You should have received a copy of the GNU General Public License and    --
27-- a copy of the GCC Runtime Library Exception along with this program;     --
28-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
29-- <http://www.gnu.org/licenses/>.                                          --
30--                                                                          --
31-- GNAT was originally developed  by the GNAT team at  New York University. --
32-- Extensive contributions were provided by Ada Core Technologies Inc.      --
33--                                                                          --
34------------------------------------------------------------------------------
35
36with Ada.Task_Identification;
37
38generic
39   type Attribute is private;
40   Initial_Value : Attribute;
41
42package Ada.Task_Attributes is
43
44   --  Note that this package will use an efficient implementation with no
45   --  locks and no extra dynamic memory allocation if Attribute is the size
46   --  of either Integer or System.Address, and Initial_Value is 0 (null for
47   --  an access type).
48
49   --  Other types and initial values are supported, but will require
50   --  the use of locking and a level of indirection (meaning extra dynamic
51   --  memory allocation).
52
53   --  The maximum number of task attributes supported by this implementation
54   --  is determined by the constant System.Parameters.Max_Attribute_Count.
55   --  If you exceed this number, Storage_Error will be raised during the
56   --  elaboration of the instantiation of this package.
57
58   type Attribute_Handle is access all Attribute;
59
60   function Value
61     (T : Ada.Task_Identification.Task_Id :=
62            Ada.Task_Identification.Current_Task) return Attribute;
63   --  Return the value of the corresponding attribute of T. Tasking_Error
64   --  is raised if T is terminated and Program_Error will be raised if T
65   --  is Null_Task_Id.
66
67   function Reference
68     (T : Ada.Task_Identification.Task_Id :=
69            Ada.Task_Identification.Current_Task) return Attribute_Handle;
70   --  Return an access value that designates the corresponding attribute of
71   --  T. Tasking_Error is raised if T is terminated and Program_Error will be
72   --  raised if T is Null_Task_Id.
73
74   procedure Set_Value
75     (Val : Attribute;
76      T   : Ada.Task_Identification.Task_Id :=
77              Ada.Task_Identification.Current_Task);
78   --  Finalize the old value of the attribute of T and assign Val to that
79   --  attribute. Tasking_Error is raised if T is terminated and Program_Error
80   --  will be raised if T is Null_Task_Id.
81
82   procedure Reinitialize
83     (T : Ada.Task_Identification.Task_Id :=
84            Ada.Task_Identification.Current_Task);
85   --  Same as Set_Value (Initial_Value, T). Tasking_Error is raised if T is
86   --  terminated and Program_Error will be raised if T is Null_Task_Id.
87
88private
89   pragma Inline (Value);
90   pragma Inline (Reference);
91   pragma Inline (Set_Value);
92   pragma Inline (Reinitialize);
93end Ada.Task_Attributes;
94