gcc/ada/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) 1992-2006 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 2,  or (at your option) any later ver- --
  14 -- sion. GNARL 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.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNARL; see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNARL was developed by the GNARL team at Florida State University.       --
  30 -- Extensive contributions were provided by Ada Core Technologies, Inc.     --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This is a Solaris version of this package.
  35
  36 --  Make a careful study of all signals available under the OS,
  37 --  to see which need to be reserved, kept always unmasked,
  38 --  or kept always unmasked.
  39
  40 --  Be on the lookout for special signals that
  41 --  may be used by the thread library.
  42
  43 package body System.Interrupt_Management is
  44
  45    use Interfaces.C;
  46    use System.OS_Interface;
  47
  48    type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID;
  49
  50    Exception_Interrupts : constant Interrupt_List :=
  51      (SIGFPE, SIGILL, SIGSEGV, SIGBUS);
  52
  53    Unreserve_All_Interrupts : Interfaces.C.int;
  54    pragma Import
  55      (C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts");
  56
  57    function State (Int : Interrupt_ID) return Character;
  58    pragma Import (C, State, "__gnat_get_interrupt_state");
  59    --  Get interrupt state.  Defined in init.c
  60    --  The input argument is the interrupt number,
  61    --  and the result is one of the following:
  62
  63    User    : constant Character := 'u';
  64    Runtime : constant Character := 'r';
  65    Default : constant Character := 's';
  66    --    'n'   this interrupt not set by any Interrupt_State pragma
  67    --    'u'   Interrupt_State pragma set state to User
  68    --    'r'   Interrupt_State pragma set state to Runtime
  69    --    's'   Interrupt_State pragma set state to System (use "default"
  70    --           system handler)
  71
  72    ----------------------
  73    -- Notify_Exception --
  74    ----------------------
  75
  76    --  This function identifies the Ada exception to be raised using
  77    --  the information when the system received a synchronous signal.
  78    --  Since this function is machine and OS dependent, different code
  79    --  has to be provided for different target.
  80
  81    procedure Notify_Exception
  82      (signo   : Signal;
  83       info    : access siginfo_t;
  84       context : access ucontext_t);
  85
  86    ----------------------
  87    -- Notify_Exception --
  88    ----------------------
  89
  90    procedure Notify_Exception
  91      (signo   : Signal;
  92       info    : access siginfo_t;
  93       context : access ucontext_t)
  94    is
  95       pragma Unreferenced (context);
  96    begin
  97       --  Check that treatment of exception propagation here
  98       --  is consistent with treatment of the abort signal in
  99       --  System.Task_Primitives.Operations.
 100
 101       case signo is
 102          when SIGFPE =>
 103             case info.si_code is
 104                when  FPE_INTDIV |
 105                      FPE_INTOVF |
 106                      FPE_FLTDIV |
 107                      FPE_FLTOVF |
 108                      FPE_FLTUND |
 109                      FPE_FLTRES |
 110                      FPE_FLTINV |
 111                      FPE_FLTSUB =>
 112
 113                   raise Constraint_Error;
 114
 115                when others =>
 116                   pragma Assert (False);
 117                   null;
 118             end case;
 119
 120          when SIGILL | SIGSEGV | SIGBUS  =>
 121             raise Storage_Error;
 122
 123          when others =>
 124             pragma Assert (False);
 125             null;
 126       end case;
 127    end Notify_Exception;
 128
 129    ----------------
 130    -- Initialize --
 131    ----------------
 132
 133    Initialized : Boolean := False;
 134
 135    procedure Initialize is
 136       act     : aliased struct_sigaction;
 137       old_act : aliased struct_sigaction;
 138       mask    : aliased sigset_t;
 139       Result  : Interfaces.C.int;
 140
 141    begin
 142       if Initialized then
 143          return;
 144       end if;
 145
 146       Initialized := True;
 147
 148       --  Need to call pthread_init very early because it is doing signal
 149       --  initializations.
 150
 151       pthread_init;
 152
 153       --  Change this if you want to use another signal for task abort.
 154       --  SIGTERM might be a good one.
 155
 156       Abort_Task_Interrupt := SIGABRT;
 157
 158       act.sa_handler := Notify_Exception'Address;
 159
 160       --  Set sa_flags to SA_NODEFER so that during the handler execution
 161       --  we do not change the Signal_Mask to be masked for the Signal.
 162       --  This is a temporary fix to the problem that the Signal_Mask is
 163       --  not restored after the exception (longjmp) from the handler.
 164       --  The right fix should be made in sigsetjmp so that we save
 165       --  the Signal_Set and restore it after a longjmp.
 166
 167       --  In that case, this field should be changed back to 0. ??? (Dong-Ik)
 168
 169       act.sa_flags := 16;
 170
 171       Result := sigemptyset (mask'Access);
 172       pragma Assert (Result = 0);
 173
 174       --  ??? For the same reason explained above, we can't mask these
 175       --  signals because otherwise we won't be able to catch more than
 176       --  one signal.
 177
 178       act.sa_mask := mask;
 179
 180       pragma Assert (Keep_Unmasked = (Interrupt_ID'Range => False));
 181       pragma Assert (Reserve = (Interrupt_ID'Range => False));
 182
 183       for J in Exception_Interrupts'Range loop
 184          if State (Exception_Interrupts (J)) /= User then
 185             Keep_Unmasked (Exception_Interrupts (J)) := True;
 186             Reserve (Exception_Interrupts (J)) := True;
 187
 188             if State (Exception_Interrupts (J)) /= Default then
 189                Result :=
 190                  sigaction
 191                  (Signal (Exception_Interrupts (J)), act'Unchecked_Access,
 192                   old_act'Unchecked_Access);
 193                pragma Assert (Result = 0);
 194             end if;
 195          end if;
 196       end loop;
 197
 198       if State (Abort_Task_Interrupt) /= User then
 199          Keep_Unmasked (Abort_Task_Interrupt) := True;
 200          Reserve (Abort_Task_Interrupt) := True;
 201       end if;
 202
 203       --  Set SIGINT to unmasked state as long as it's
 204       --  not in "User" state.  Check for Unreserve_All_Interrupts last
 205
 206       if State (SIGINT) /= User then
 207          Keep_Unmasked (SIGINT) := True;
 208          Reserve (SIGINT) := True;
 209       end if;
 210
 211       --  Check all signals for state that requires keeping them
 212       --  unmasked and reserved
 213
 214       for J in Interrupt_ID'Range loop
 215          if State (J) = Default or else State (J) = Runtime then
 216             Keep_Unmasked (J) := True;
 217             Reserve (J) := True;
 218          end if;
 219       end loop;
 220
 221       --  Add the set of signals that must always be unmasked for this target
 222
 223       for J in Unmasked'Range loop
 224          Keep_Unmasked (Interrupt_ID (Unmasked (J))) := True;
 225          Reserve (Interrupt_ID (Unmasked (J))) := True;
 226       end loop;
 227
 228       --  Add target-specific reserved signals
 229
 230       for J in Reserved'Range loop
 231          Reserve (Interrupt_ID (Reserved (J))) := True;
 232       end loop;
 233
 234       --  Process pragma Unreserve_All_Interrupts. This overrides any
 235       --  settings due to pragma Interrupt_State:
 236
 237       if Unreserve_All_Interrupts /= 0 then
 238          Keep_Unmasked (SIGINT) := False;
 239          Reserve (SIGINT) := False;
 240       end if;
 241
 242       --  We do not have Signal 0 in reality. We just use this value
 243       --  to identify not existing signals (see s-intnam.ads). Therefore,
 244       --  Signal 0 should not be used in all signal related operations hence
 245       --  mark it as reserved.
 246
 247       Reserve (0) := True;
 248    end Initialize;
 249
 250 end System.Interrupt_Management;