gcc/ada/5fintman.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                GNU ADA 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) 1991-1994, Florida State University            --
  10 --             Copyright (C) 1995-2003, Ada Core Technologies               --
  11 --                                                                          --
  12 -- GNARL is free software; you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  15 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNARL; see file COPYING.  If not, write --
  20 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  21 -- MA 02111-1307, USA.                                                      --
  22 --                                                                          --
  23 -- As a special exception,  if other files  instantiate  generics from this --
  24 -- unit, or you link  this unit with other files  to produce an executable, --
  25 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  26 -- covered  by the  GNU  General  Public  License.  This exception does not --
  27 -- however invalidate  any other reasons why  the executable file  might be --
  28 -- covered by the  GNU Public License.                                      --
  29 --                                                                          --
  30 -- GNARL was developed by the GNARL team at Florida State University.       --
  31 -- Extensive contributions were provided by Ada Core Technologies, Inc.     --
  32 --                                                                          --
  33 ------------------------------------------------------------------------------
  34
  35 --  This is a SGI Pthread version of this package.
  36
  37 --  PLEASE DO NOT add any dependences on other packages.
  38 --  This package is designed to work with or without tasking support.
  39
  40 --  Make a careful study of all signals available under the OS,
  41 --  to see which need to be reserved, kept always unmasked,
  42 --  or kept always unmasked.
  43 --  Be on the lookout for special signals that
  44 --  may be used by the thread library.
  45
  46 with Interfaces.C;
  47 --  used for int
  48
  49 with System.OS_Interface;
  50 --  used for various Constants, Signal and types
  51
  52 package body System.Interrupt_Management is
  53
  54    use System.OS_Interface;
  55
  56    type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID;
  57    Exception_Interrupts : constant Interrupt_List :=
  58      (SIGTSTP, SIGILL, SIGTRAP, SIGEMT, SIGFPE, SIGBUS, SIGSTOP, SIGKILL,
  59       SIGSEGV, SIGSYS, SIGXCPU, SIGXFSZ, SIGPROF, SIGPTINTR, SIGPTRESCHED,
  60       SIGABRT, SIGPIPE);
  61
  62    ---------------------------
  63    -- Initialize_Interrupts --
  64    ---------------------------
  65
  66    --  Nothing needs to be done on this platform
  67
  68    procedure Initialize_Interrupts is
  69    begin
  70       null;
  71    end Initialize_Interrupts;
  72
  73    Unreserve_All_Interrupts : Interfaces.C.int;
  74    pragma Import
  75      (C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts");
  76
  77    use type Interfaces.C.int;
  78
  79 begin
  80    declare
  81       function State (Int : Interrupt_ID) return Character;
  82       pragma Import (C, State, "__gnat_get_interrupt_state");
  83
  84       --  Get interrupt state.  Defined in a-init.c
  85       --  The input argument is the interrupt number,
  86       --  and the result is one of the following:
  87
  88       User    : constant Character := 'u';
  89       Runtime : constant Character := 'r';
  90       Default : constant Character := 's';
  91       --    'n'   this interrupt not set by any Interrupt_State pragma
  92       --    'u'   Interrupt_State pragma set state to User
  93       --    'r'   Interrupt_State pragma set state to Runtime
  94       --    's'   Interrupt_State pragma set state to System (use "default"
  95       --           system handler)
  96
  97    begin
  98       Abort_Task_Interrupt := SIGABRT;
  99
 100       --  Change this if you want to use another signal for task abort.
 101       --  SIGTERM might be a good one.
 102
 103       pragma Assert (Keep_Unmasked = (Interrupt_ID'Range => False));
 104       pragma Assert (Reserve = (Interrupt_ID'Range => False));
 105
 106       --  Process state of exception signals
 107
 108       for J in Exception_Interrupts'Range loop
 109          if State (Exception_Interrupts (J)) /= User then
 110             Keep_Unmasked (Exception_Interrupts (J)) := True;
 111             Reserve (Exception_Interrupts (J)) := True;
 112          end if;
 113       end loop;
 114
 115       if State (Abort_Task_Interrupt) /= User then
 116          Keep_Unmasked (Abort_Task_Interrupt) := True;
 117          Reserve (Abort_Task_Interrupt) := True;
 118       end if;
 119
 120       --  Set SIGINT to unmasked state as long as it's
 121       --  not in "User" state.  Check for Unreserve_All_Interrupts last
 122
 123       if State (SIGINT) /= User then
 124          Keep_Unmasked (SIGINT) := True;
 125       end if;
 126
 127       --  Check all signals for state that requires keeping them
 128       --  unmasked and reserved
 129
 130       for J in Interrupt_ID'Range loop
 131          if State (J) = Default or else State (J) = Runtime then
 132             Keep_Unmasked (J) := True;
 133             Reserve (J) := True;
 134          end if;
 135       end loop;
 136
 137       --  Process pragma Unreserve_All_Interrupts. This overrides any
 138       --  settings due to pragma Interrupt_State:
 139
 140       if Unreserve_All_Interrupts /= 0 then
 141          Keep_Unmasked (SIGINT) := False;
 142          Reserve (SIGINT) := False;
 143       end if;
 144
 145       --  We do not have Signal 0 in reality. We just use this value
 146       --  to identify not existing signals (see s-intnam.ads). Therefore,
 147       --  Signal 0 should not be used in all signal related operations hence
 148       --  mark it as reserved.
 149
 150       Reserve (0) := True;
 151    end;
 152 end System.Interrupt_Management;