File : s-intman-solaris.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
4 -- --
5 -- 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 --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
10 -- --
11 -- GNARL is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
26 -- --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 -- This is a Solaris version of this package
33
34 -- Make a careful study of all signals available under the OS, to see which
35 -- need to be reserved, kept always unmasked, or kept always unmasked.
36
37 -- Be on the lookout for special signals that may be used by the thread
38 -- library.
39
40 package body System.Interrupt_Management is
41
42 use Interfaces.C;
43 use System.OS_Interface;
44
45 type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID;
46
47 Exception_Interrupts : constant Interrupt_List :=
48 (SIGFPE, SIGILL, SIGSEGV, SIGBUS);
49
50 Unreserve_All_Interrupts : Interfaces.C.int;
51 pragma Import
52 (C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts");
53
54 function State (Int : Interrupt_ID) return Character;
55 pragma Import (C, State, "__gnat_get_interrupt_state");
56 -- Get interrupt state. Defined in init.c
57 -- The input argument is the interrupt number,
58 -- and the result is one of the following:
59
60 User : constant Character := 'u';
61 Runtime : constant Character := 'r';
62 Default : constant Character := 's';
63 -- 'n' this interrupt not set by any Interrupt_State pragma
64 -- 'u' Interrupt_State pragma set state to User
65 -- 'r' Interrupt_State pragma set state to Runtime
66 -- 's' Interrupt_State pragma set state to System (use "default"
67 -- system handler)
68
69 ----------------------
70 -- Notify_Exception --
71 ----------------------
72
73 -- This function identifies the Ada exception to be raised using the
74 -- information when the system received a synchronous signal. Since this
75 -- function is machine and OS dependent, different code has to be provided
76 -- for different target.
77
78 procedure Notify_Exception
79 (signo : Signal;
80 info : access siginfo_t;
81 context : access ucontext_t);
82
83 ----------------------
84 -- Notify_Exception --
85 ----------------------
86
87 procedure Notify_Exception
88 (signo : Signal;
89 info : access siginfo_t;
90 context : access ucontext_t)
91 is
92 pragma Unreferenced (info);
93
94 begin
95 -- Perform the necessary context adjustments prior to a raise
96 -- from a signal handler.
97
98 Adjust_Context_For_Raise (signo, context.all'Address);
99
100 -- Check that treatment of exception propagation here is consistent with
101 -- treatment of the abort signal in System.Task_Primitives.Operations.
102
103 case signo is
104 when SIGFPE =>
105 raise Constraint_Error;
106 when SIGILL =>
107 raise Program_Error;
108 when SIGSEGV =>
109 raise Storage_Error;
110 when SIGBUS =>
111 raise Storage_Error;
112 when others =>
113 null;
114 end case;
115 end Notify_Exception;
116
117 ----------------
118 -- Initialize --
119 ----------------
120
121 Initialized : Boolean := False;
122
123 procedure Initialize is
124 act : aliased struct_sigaction;
125 old_act : aliased struct_sigaction;
126 mask : aliased sigset_t;
127 Result : Interfaces.C.int;
128
129 begin
130 if Initialized then
131 return;
132 end if;
133
134 Initialized := True;
135
136 -- Need to call pthread_init very early because it is doing signal
137 -- initializations.
138
139 pthread_init;
140
141 -- Change this if you want to use another signal for task abort.
142 -- SIGTERM might be a good one.
143
144 Abort_Task_Interrupt := SIGABRT;
145
146 act.sa_handler := Notify_Exception'Address;
147
148 -- Set sa_flags to SA_NODEFER so that during the handler execution
149 -- we do not change the Signal_Mask to be masked for the Signal.
150 -- This is a temporary fix to the problem that the Signal_Mask is
151 -- not restored after the exception (longjmp) from the handler.
152 -- The right fix should be made in sigsetjmp so that we save
153 -- the Signal_Set and restore it after a longjmp.
154
155 -- In that case, this field should be changed back to 0. ??? (Dong-Ik)
156
157 act.sa_flags := 16;
158
159 Result := sigemptyset (mask'Access);
160 pragma Assert (Result = 0);
161
162 -- ??? For the same reason explained above, we can't mask these signals
163 -- because otherwise we won't be able to catch more than one signal.
164
165 act.sa_mask := mask;
166
167 pragma Assert (Keep_Unmasked = (Interrupt_ID'Range => False));
168 pragma Assert (Reserve = (Interrupt_ID'Range => False));
169
170 for J in Exception_Interrupts'Range loop
171 if State (Exception_Interrupts (J)) /= User then
172 Keep_Unmasked (Exception_Interrupts (J)) := True;
173 Reserve (Exception_Interrupts (J)) := True;
174
175 if State (Exception_Interrupts (J)) /= Default then
176 Result :=
177 sigaction
178 (Signal (Exception_Interrupts (J)), act'Unchecked_Access,
179 old_act'Unchecked_Access);
180 pragma Assert (Result = 0);
181 end if;
182 end if;
183 end loop;
184
185 if State (Abort_Task_Interrupt) /= User then
186 Keep_Unmasked (Abort_Task_Interrupt) := True;
187 Reserve (Abort_Task_Interrupt) := True;
188 end if;
189
190 -- Set SIGINT to unmasked state as long as it's
191 -- not in "User" state. Check for Unreserve_All_Interrupts last
192
193 if State (SIGINT) /= User then
194 Keep_Unmasked (SIGINT) := True;
195 Reserve (SIGINT) := True;
196 end if;
197
198 -- Check all signals for state that requires keeping them
199 -- unmasked and reserved
200
201 for J in Interrupt_ID'Range loop
202 if State (J) = Default or else State (J) = Runtime then
203 Keep_Unmasked (J) := True;
204 Reserve (J) := True;
205 end if;
206 end loop;
207
208 -- Add the set of signals that must always be unmasked for this target
209
210 for J in Unmasked'Range loop
211 Keep_Unmasked (Interrupt_ID (Unmasked (J))) := True;
212 Reserve (Interrupt_ID (Unmasked (J))) := True;
213 end loop;
214
215 -- Add target-specific reserved signals
216
217 for J in Reserved'Range loop
218 Reserve (Interrupt_ID (Reserved (J))) := True;
219 end loop;
220
221 -- Process pragma Unreserve_All_Interrupts. This overrides any
222 -- settings due to pragma Interrupt_State:
223
224 if Unreserve_All_Interrupts /= 0 then
225 Keep_Unmasked (SIGINT) := False;
226 Reserve (SIGINT) := False;
227 end if;
228
229 -- We do not have Signal 0 in reality. We just use this value to
230 -- identify not existing signals (see s-intnam.ads). Therefore, Signal 0
231 -- should not be used in all signal related operations hence mark it as
232 -- reserved.
233
234 Reserve (0) := True;
235 end Initialize;
236
237 end System.Interrupt_Management;