1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
------------------------------------------------------------------------------
-- --
-- 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, 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
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;
|
