aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.9/gcc/ada/s-intman-susv3.adb
blob: 864d7e1d2dd5cca56c619a44d6073a6c7fda2e1c (plain)
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
------------------------------------------------------------------------------
--                                                                          --
--                 GNAT RUN-TIME 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                                 --
--                                                                          --
--          Copyright (C) 1992-2009, Free Software Foundation, Inc.         --
--                                                                          --
-- 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 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/>.                                          --
--                                                                          --
-- GNARL was developed by the GNARL team at Florida State University.       --
-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
--                                                                          --
------------------------------------------------------------------------------

--  This is the SuSV3 threads version of this package

--  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.

--  Since this is a multi target file, the signal <-> exception mapping
--  is simple minded. If you need a more precise and target specific
--  signal handling, create a new s-intman.adb that will fit your needs.

--  This file assumes that:

--    SIGINT exists and will be kept unmasked unless the pragma
--     Unreserve_All_Interrupts is specified anywhere in the application.

--    System.OS_Interface contains the following:
--      SIGADAABORT: the signal that will be used to abort tasks.
--      Unmasked: the OS specific set of signals that should be unmasked in
--                all the threads. SIGADAABORT is unmasked by
--                default
--      Reserved: the OS specific set of signals that are reserved.

package body System.Interrupt_Management is

   use Interfaces.C;
   use System.OS_Interface;

   Unreserve_All_Interrupts : Interfaces.C.int;
   pragma Import
     (C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts");

   -----------------------
   -- Local Subprograms --
   -----------------------

   function State (Int : Interrupt_ID) return Character;
   pragma Import (C, State, "__gnat_get_interrupt_state");
   --  Get interrupt state. Defined in init.c The input argument is the
   --  interrupt number, and the result is one of the following:

   User    : constant Character := 'u';
   Runtime : constant Character := 'r';
   Default : constant Character := 's';
   --    'n'   this interrupt not set by any Interrupt_State pragma
   --    'u'   Interrupt_State pragma set state to User
   --    'r'   Interrupt_State pragma set state to Runtime
   --    's'   Interrupt_State pragma set state to System (use "default"
   --           system handler)

   ----------------
   -- Initialize --
   ----------------

   Initialized : Boolean := False;

   procedure Initialize is
   begin
      if Initialized then
         return;
      end if;

      Initialized := True;

      --  Need to call pthread_init very early because it is doing signal
      --  initializations.

      pthread_init;

      Abort_Task_Interrupt := SIGADAABORT;

      pragma Assert (Keep_Unmasked = (Interrupt_ID'Range => False));
      pragma Assert (Reserve = (Interrupt_ID'Range => False));

      --  Process state of exception signals

      for J in Exception_Signals'Range loop
         declare
            Sig : constant Signal := Exception_Signals (J);
            Id : constant Interrupt_ID := Interrupt_ID (Sig);
         begin
            if State (Id) /= User then
               Keep_Unmasked (Id) := True;
               Reserve (Id) := True;
            end if;
         end;
      end loop;

      if State (Abort_Task_Interrupt) /= User then
         Keep_Unmasked (Abort_Task_Interrupt) := True;
         Reserve (Abort_Task_Interrupt) := True;
      end if;

      --  Set SIGINT to unmasked state as long as it is not in "User" state.
      --  Check for Unreserve_All_Interrupts last.

      if State (SIGINT) /= User then
         Keep_Unmasked (SIGINT) := True;
         Reserve (SIGINT) := True;
      end if;

      --  Check all signals for state that requires keeping them unmasked and
      --  reserved.

      for J in Interrupt_ID'Range loop
         if State (J) = Default or else State (J) = Runtime then
            Keep_Unmasked (J) := True;
            Reserve (J) := True;
         end if;
      end loop;

      --  Add the set of signals that must always be unmasked for this target

      for J in Unmasked'Range loop
         Keep_Unmasked (Interrupt_ID (Unmasked (J))) := True;
         Reserve (Interrupt_ID (Unmasked (J))) := True;
      end loop;

      --  Add target-specific reserved signals

      for J in Reserved'Range loop
         Reserve (Interrupt_ID (Reserved (J))) := True;
      end loop;

      --  Process pragma Unreserve_All_Interrupts. This overrides any settings
      --  due to pragma Interrupt_State:

      if Unreserve_All_Interrupts /= 0 then
         Keep_Unmasked (SIGINT) := False;
         Reserve (SIGINT) := False;
      end if;

      --  We do not really have Signal 0. We just use this value to identify
      --  non-existent signals (see s-intnam.ads). Therefore, Signal should not
      --  be used in all signal related operations hence mark it as reserved.

      Reserve (0) := True;
   end Initialize;

end System.Interrupt_Management;