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
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237 | ------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . S O F T _ L I N K S . T A S K I N G --
-- --
-- B o d y --
-- --
-- Copyright (C) 2004-2023, Free Software Foundation, Inc. --
-- --
-- GNAT 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 3, or (at your option) any later ver- --
-- sion. GNAT 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. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
pragma Style_Checks (All_Checks);
-- Turn off subprogram alpha ordering check, since we group soft link bodies
-- and dummy soft link bodies together separately in this unit.
with Ada.Exceptions;
with Ada.Exceptions.Is_Null_Occurrence;
with System.Task_Primitives.Operations;
with System.Tasking;
with System.Stack_Checking;
with System.Secondary_Stack;
package body System.Soft_Links.Tasking is
package STPO renames System.Task_Primitives.Operations;
package SSL renames System.Soft_Links;
use Ada.Exceptions;
use type System.Secondary_Stack.SS_Stack_Ptr;
use type System.Tasking.Task_Id;
use type System.Tasking.Termination_Handler;
----------------
-- Local Data --
----------------
Initialized : Boolean := False;
-- Boolean flag that indicates whether the tasking soft links have
-- already been set.
-----------------------------------------------------------------
-- Tasking Versions of Services Needed by Non-Tasking Programs --
-----------------------------------------------------------------
function Get_Jmpbuf_Address return Address;
procedure Set_Jmpbuf_Address (Addr : Address);
-- Get/Set Jmpbuf_Address for current task
function Get_Sec_Stack return SST.SS_Stack_Ptr;
procedure Set_Sec_Stack (Stack : SST.SS_Stack_Ptr);
-- Get/Set location of current task's secondary stack
procedure Timed_Delay_T (Time : Duration; Mode : Integer);
-- Task-safe version of SSL.Timed_Delay
procedure Task_Termination_Handler_T (Excep : SSL.EO);
-- Task-safe version of the task termination procedure
function Get_Stack_Info return Stack_Checking.Stack_Access;
-- Get access to the current task's Stack_Info
--------------------------
-- Soft-Link Get Bodies --
--------------------------
function Get_Jmpbuf_Address return Address is
begin
return STPO.Self.Common.Compiler_Data.Jmpbuf_Address;
end Get_Jmpbuf_Address;
function Get_Sec_Stack return SST.SS_Stack_Ptr is
begin
return Result : constant SST.SS_Stack_Ptr :=
STPO.Self.Common.Compiler_Data.Sec_Stack_Ptr
do
pragma Assert (Result /= null);
end return;
end Get_Sec_Stack;
function Get_Stack_Info return Stack_Checking.Stack_Access is
begin
return STPO.Self.Common.Compiler_Data.Pri_Stack_Info'Access;
end Get_Stack_Info;
--------------------------
-- Soft-Link Set Bodies --
--------------------------
procedure Set_Jmpbuf_Address (Addr : Address) is
begin
STPO.Self.Common.Compiler_Data.Jmpbuf_Address := Addr;
end Set_Jmpbuf_Address;
procedure Set_Sec_Stack (Stack : SST.SS_Stack_Ptr) is
begin
STPO.Self.Common.Compiler_Data.Sec_Stack_Ptr := Stack;
end Set_Sec_Stack;
-------------------
-- Timed_Delay_T --
-------------------
procedure Timed_Delay_T (Time : Duration; Mode : Integer) is
Self_Id : constant System.Tasking.Task_Id := STPO.Self;
begin
-- In case pragma Detect_Blocking is active then Program_Error
-- must be raised if this potentially blocking operation
-- is called from a protected operation.
if System.Tasking.Detect_Blocking
and then Self_Id.Common.Protected_Action_Nesting > 0
then
raise Program_Error with "potentially blocking operation";
else
Abort_Defer.all;
STPO.Timed_Delay (Self_Id, Time, Mode);
Abort_Undefer.all;
end if;
end Timed_Delay_T;
--------------------------------
-- Task_Termination_Handler_T --
--------------------------------
procedure Task_Termination_Handler_T (Excep : SSL.EO) is
Self_Id : constant System.Tasking.Task_Id := STPO.Self;
Cause : System.Tasking.Cause_Of_Termination;
EO : Ada.Exceptions.Exception_Occurrence;
begin
-- We can only be here because we are terminating the environment task.
-- Task termination for all other tasks is handled in the Task_Wrapper.
-- We do not want to enable this check and e.g. call System.OS_Lib.Abort
-- here because some restricted run-times may not have System.OS_Lib
-- and calling abort may do more harm than good to the main application.
pragma Assert (Self_Id = STPO.Environment_Task);
-- Normal task termination
if Is_Null_Occurrence (Excep) then
Cause := System.Tasking.Normal;
Ada.Exceptions.Save_Occurrence (EO, Ada.Exceptions.Null_Occurrence);
-- Abnormal task termination
elsif Exception_Identity (Excep) = Standard'Abort_Signal'Identity then
Cause := System.Tasking.Abnormal;
Ada.Exceptions.Save_Occurrence (EO, Ada.Exceptions.Null_Occurrence);
-- Termination because of an unhandled exception
else
Cause := System.Tasking.Unhandled_Exception;
Ada.Exceptions.Save_Occurrence (EO, Excep);
end if;
-- There is no need for explicit protection against race conditions for
-- this part because it can only be executed by the environment task
-- after all the other tasks have been finalized. Note that there is no
-- fall-back handler which could apply to this environment task because
-- it has no parents, and, as specified in ARM C.7.3 par. 9/2, "the
-- fall-back handler applies only to the dependent tasks of the task".
if Self_Id.Common.Specific_Handler /= null then
begin
Self_Id.Common.Specific_Handler.all (Cause, Self_Id, EO);
exception
-- RM-C.7.3(16) requires all exceptions raised here to be ignored
when others =>
null;
end;
end if;
end Task_Termination_Handler_T;
-----------------------------
-- Init_Tasking_Soft_Links --
-----------------------------
procedure Init_Tasking_Soft_Links is
begin
-- Set links only if not set already
if not Initialized then
-- Mark tasking soft links as initialized
Initialized := True;
-- The application being executed uses tasking so that the tasking
-- version of the following soft links need to be used.
SSL.Get_Jmpbuf_Address := Get_Jmpbuf_Address'Access;
SSL.Set_Jmpbuf_Address := Set_Jmpbuf_Address'Access;
SSL.Get_Sec_Stack := Get_Sec_Stack'Access;
SSL.Get_Stack_Info := Get_Stack_Info'Access;
SSL.Set_Sec_Stack := Set_Sec_Stack'Access;
SSL.Timed_Delay := Timed_Delay_T'Access;
SSL.Task_Termination_Handler := Task_Termination_Handler_T'Access;
-- No need to create a new secondary stack, since we will use the
-- default one created in s-secsta.adb.
SSL.Set_Sec_Stack (SSL.Get_Sec_Stack_NT);
SSL.Set_Jmpbuf_Address (SSL.Get_Jmpbuf_Address_NT);
end if;
pragma Assert (Get_Sec_Stack /= null);
end Init_Tasking_Soft_Links;
end System.Soft_Links.Tasking;
|