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
|
------------------------------------------------------------------------------
-- --
-- GNU ADA RUNTIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . I N T E R R U P T _ M A N A G E M E N T --
-- --
-- B o d y --
-- (Version for new GNARL) --
-- --
-- $Revision: 1.3 $ --
-- --
-- Copyright (C) 1991,1992,1993,1994,1995,1996 Florida State University --
-- --
-- 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. It is --
-- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
-- State University (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
-- This is the FreeBSD PTHREADS version of this package
-- This is only a first approximation.
-- It should be autogenerated by the m4 macro processor.
-- Contributed by Peter Burwood (gnat@arcangel.dircon.co.uk).
-- This file performs the system-dependent translation between machine
-- exceptions and the Ada exceptions, if any, that should be raised when
-- they occur. This version works for FreeBSD. Contributed by
-- Daniel M. Eischen (eischen@vigrid.com).
-- PLEASE DO NOT add any dependences on other packages.
-- This package is designed to work with or without tasking support.
-- See the other warnings in the package specification before making
-- any modifications to this file.
-- Make a careful study of all signals available under the OS,
-- to see which need to be reserved, kept always unmasked,
-- or kept always unmasked.
-- Be on the lookout for special signals that
-- may be used by the thread library.
with Interfaces.C;
-- used for int and other types
with System.OS_Interface;
-- used for various Constants, Signal and types
package body System.Interrupt_Management is
use Interfaces.C;
use System.OS_Interface;
type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID;
Exception_Interrupts : constant Interrupt_List :=
(SIGFPE, SIGILL, SIGSEGV, SIGBUS);
Unreserve_All_Interrupts : Interfaces.C.int;
pragma Import
(C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts");
----------------------
-- Notify_Exception --
----------------------
Signal_Mask : aliased sigset_t;
-- The set of signals handled by Notify_Exception
-- This function identifies the Ada exception to be raised using
-- the information when the system received a synchronous signal.
-- Since this function is machine and OS dependent, different code
-- has to be provided for different target.
-- Language specs say signal handlers take exactly one arg, even
-- though FreeBSD actually supplies three. Ugh!
procedure Notify_Exception
(signo : Signal;
code : Interfaces.C.int;
context : access struct_sigcontext);
procedure Notify_Exception
(signo : Signal;
code : Interfaces.C.int;
context : access struct_sigcontext) is
begin
-- As long as we are using a longjmp to return control to the
-- exception handler on the runtime stack, we are safe. The original
-- signal mask (the one we had before coming into this signal catching
-- function) will be restored by the longjmp. Therefore, raising
-- an exception in this handler should be a safe operation.
-- Check that treatment of exception propagation here
-- is consistent with treatment of the abort signal in
-- System.Task_Primitives.Operations.
case signo is
when SIGFPE =>
raise Constraint_Error;
when SIGILL =>
raise Constraint_Error;
when SIGSEGV =>
raise Storage_Error;
when SIGBUS =>
raise Storage_Error;
when others =>
pragma Assert (False);
null;
end case;
end Notify_Exception;
---------------------------
-- Initialize_Interrupts --
---------------------------
-- Nothing needs to be done on this platform.
procedure Initialize_Interrupts is
begin
null;
end Initialize_Interrupts;
begin
declare
act : aliased struct_sigaction;
old_act : aliased struct_sigaction;
Result : Interfaces.C.int;
begin
Abort_Task_Interrupt := SIGABRT;
-- Change this if you want to use another signal for task abort.
-- SIGTERM might be a good one.
act.sa_handler := Notify_Exception'Address;
act.sa_flags := 16#010#;
-- Set sa_flags to SA_NODEFER so that during the handler execution
-- we do not change the Signal_Mask to be masked for the Signal.
-- This is a temporary fix to the problem that the Signal_Mask is
-- not restored after the exception (longjmp) from the handler.
-- The right fix should be made in sigsetjmp so that we save
-- the Signal_Set and restore it after a longjmp.
-- In that case, this field should be changed back to 0. ???
Result := sigemptyset (Signal_Mask'Access);
pragma Assert (Result = 0);
for I in Exception_Interrupts'Range loop
Result :=
sigaddset
(Signal_Mask'Access, Signal (Exception_Interrupts (I)));
pragma Assert (Result = 0);
end loop;
act.sa_mask := Signal_Mask;
for I in Exception_Interrupts'Range loop
Keep_Unmasked (Exception_Interrupts (I)) := True;
Result :=
sigaction
(Signal (Exception_Interrupts (I)), act'Unchecked_Access,
old_act'Unchecked_Access);
pragma Assert (Result = 0);
end loop;
Keep_Unmasked (Abort_Task_Interrupt) := True;
Keep_Unmasked (SIGSTOP) := True;
Keep_Unmasked (SIGKILL) := True;
-- By keeping SIGINT unmasked, allow the user to do a Ctrl-C, but in the
-- same time, disable the ability of handling this signal
-- via Ada.Interrupts.
-- The pragma Unreserve_All_Interrupts let the user the ability to
-- change this behavior.
if Unreserve_All_Interrupts = 0 then
Keep_Unmasked (SIGINT) := True;
else
Keep_Unmasked (SIGINT) := False;
end if;
-- FreeBSD uses SIGINFO to dump thread status to stdout. If
-- the user really wants to attach his own handler, let him.
-- FreeBSD pthreads uses setitimer/getitimer for thread scheduling.
-- Specifically, it uses timer ITIMER_PROF which generates SIGPROF.
-- FreeBSD pthreads also needs SIGCHLD. The FreeBSD threads library
-- also uses SIGINFO for debugging, but it's not required so we'll
-- let an Ada application use it.
Keep_Unmasked (SIGCHLD) := True;
Keep_Unmasked (SIGPROF) := True;
Reserve := Reserve or Keep_Unmasked or Keep_Masked;
Reserve (0) := true;
-- We do not have Signal 0 in reality. We just use this value
-- to identify non-existent signals (see s-intnam.ads). Therefore,
-- Signal 0 should not be used in all signal related operations hence
-- mark it as reserved.
end;
end System.Interrupt_Management;
|
