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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
------------------------------------------------------------------------------
-- --
-- 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 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1991-1994, Florida State University --
-- Copyright (C) 1995-2008, 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. --
-- --
------------------------------------------------------------------------------
with Ada.Unchecked_Conversion;
with System.Task_Primitives.Operations;
with System.Tasking.Initialization;
package body System.Tasking.Task_Attributes is
use Task_Primitives.Operations;
use Tasking.Initialization;
function To_Access_Address is new Ada.Unchecked_Conversion
(Access_Node, Access_Address);
-- Store pointer to indirect attribute list
--------------
-- Finalize --
--------------
procedure Finalize (X : in out Instance) is
Q, To_Be_Freed : Access_Node;
Self_Id : constant Task_Id := Self;
begin
-- Defer abort. Note that we use the nestable versions of Defer_Abort
-- and Undefer_Abort, because abort can already deferred when this is
-- called during finalization, which would cause an assert failure
-- in Defer_Abort.
Defer_Abort_Nestable (Self_Id);
Lock_RTS;
-- Remove this instantiation from the list of all instantiations
declare
P : Access_Instance;
Q : Access_Instance := All_Attributes;
begin
while Q /= null and then Q /= X'Unchecked_Access loop
P := Q; Q := Q.Next;
end loop;
pragma Assert (Q /= null);
if P = null then
All_Attributes := Q.Next;
else
P.Next := Q.Next;
end if;
end;
if X.Index /= 0 then
-- Free location of this attribute, for reuse
In_Use := In_Use and not (2**Natural (X.Index));
-- There is no need for finalization in this case, since controlled
-- types are too big to fit in the TCB.
else
-- Remove nodes for this attribute from the lists of all tasks,
-- and deallocate the nodes. Deallocation does finalization, if
-- necessary.
declare
C : System.Tasking.Task_Id := All_Tasks_List;
P : Access_Node;
begin
while C /= null loop
Write_Lock (C);
Q := To_Access_Node (C.Indirect_Attributes);
while Q /= null
and then Q.Instance /= X'Unchecked_Access
loop
P := Q;
Q := Q.Next;
end loop;
if Q /= null then
if P = null then
C.Indirect_Attributes := To_Access_Address (Q.Next);
else
P.Next := Q.Next;
end if;
-- Can't Deallocate now since we are holding RTS_Lock
Q.Next := To_Be_Freed;
To_Be_Freed := Q;
end if;
Unlock (C);
C := C.Common.All_Tasks_Link;
end loop;
end;
end if;
Unlock_RTS;
while To_Be_Freed /= null loop
Q := To_Be_Freed;
To_Be_Freed := To_Be_Freed.Next;
X.Deallocate.all (Q);
end loop;
Undefer_Abort_Nestable (Self_Id);
exception
when others =>
null;
pragma Assert (False,
"Exception in task attribute instance finalization");
end Finalize;
-------------------------
-- Finalize Attributes --
-------------------------
-- This is to be called just before the ATCB is deallocated.
-- It relies on the caller holding T.L write-lock on entry.
procedure Finalize_Attributes (T : Task_Id) is
P : Access_Node;
Q : Access_Node := To_Access_Node (T.Indirect_Attributes);
begin
-- Deallocate all the indirect attributes of this task
while Q /= null loop
P := Q;
Q := Q.Next; P.Instance.Deallocate.all (P);
end loop;
T.Indirect_Attributes := null;
exception
when others =>
null;
pragma Assert (False,
"Exception in per-task attributes finalization");
end Finalize_Attributes;
---------------------------
-- Initialize Attributes --
---------------------------
-- This is to be called by System.Tasking.Stages.Create_Task
procedure Initialize_Attributes (T : Task_Id) is
P : Access_Instance;
Self_Id : constant Task_Id := Self;
begin
Defer_Abort (Self_Id);
Lock_RTS;
-- Initialize all the direct-access attributes of this task
P := All_Attributes;
while P /= null loop
if P.Index /= 0 then
T.Direct_Attributes (P.Index) :=
Direct_Attribute_Element
(System.Storage_Elements.To_Address (P.Initial_Value));
end if;
P := P.Next;
end loop;
Unlock_RTS;
Undefer_Abort (Self_Id);
exception
when others =>
null;
pragma Assert (False);
end Initialize_Attributes;
end System.Tasking.Task_Attributes;
|
