gcc/ada/s-intman-irix-athread.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) 1991-1994, Florida State University            --
  10 --                     Copyright (C) 1995-2005, AdaCore                     --
  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,  51  Franklin  Street,  Fifth  Floor, --
  21 -- Boston, MA 02110-1301, 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 an Irix (old pthread library) version of this package.
  36
  37 --  Make a careful study of all signals available under the OS,
  38 --  to see which need to be reserved, kept always unmasked,
  39 --  or kept always unmasked.
  40
  41 --  Be on the lookout for special signals that
  42 --  may be used by the thread library.
  43
  44 with System.OS_Interface;
  45 --  used for various Constants, Signal and types
  46
  47 with Interfaces.C;
  48 --  used for "int"
  49
  50 package body System.Interrupt_Management is
  51
  52    use System.OS_Interface;
  53
  54    type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID;
  55
  56    Exception_Interrupts : constant Interrupt_List :=
  57      (SIGILL,
  58       SIGABRT,
  59       SIGFPE,
  60       SIGSEGV,
  61       SIGBUS);
  62
  63    Reserved_Interrupts : constant Interrupt_List :=
  64      (0,
  65       SIGTRAP,
  66       SIGKILL,
  67       SIGSYS,
  68       SIGALRM,
  69       SIGSTOP,
  70       SIGPTINTR,
  71       SIGPTRESCHED);
  72
  73    Abort_Signal : constant := 48;
  74    --
  75    --  Serious MOJO:  The SGI pthreads library only supports the
  76    --                 unnamed signal number 48 for pthread_kill!
  77    --
  78
  79    Unreserve_All_Interrupts : Interfaces.C.int;
  80    pragma Import
  81      (C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts");
  82
  83    function State (Int : Interrupt_ID) return Character;
  84    pragma Import (C, State, "__gnat_get_interrupt_state");
  85    --  Get interrupt state.  Defined in a-init.c
  86    --  The input argument is the interrupt number,
  87    --  and the result is one of the following:
  88
  89    User    : constant Character := 'u';
  90    Runtime : constant Character := 'r';
  91    Default : constant Character := 's';
  92    --    'n'   this interrupt not set by any Interrupt_State pragma
  93    --    'u'   Interrupt_State pragma set state to User
  94    --    'r'   Interrupt_State pragma set state to Runtime
  95    --    's'   Interrupt_State pragma set state to System (use "default"
  96    --           system handler)
  97
  98    ----------------
  99    -- Initialize --
 100    ----------------
 101
 102    procedure Initialize is
 103       use Interfaces.C;
 104    begin
 105       Abort_Task_Interrupt := Abort_Signal;
 106
 107       pragma Assert (Keep_Unmasked = (Interrupt_ID'Range => False));
 108       pragma Assert (Reserve = (Interrupt_ID'Range => False));
 109
 110       --  Process state of exception signals
 111
 112       for J in Exception_Interrupts'Range loop
 113          if State (Exception_Interrupts (J)) /= User then
 114             Keep_Unmasked (Exception_Interrupts (J)) := True;
 115             Reserve (Exception_Interrupts (J)) := True;
 116          end if;
 117       end loop;
 118
 119       if State (Abort_Task_Interrupt) /= User then
 120          Keep_Unmasked (Abort_Task_Interrupt) := True;
 121          Reserve (Abort_Task_Interrupt) := True;
 122       end if;
 123
 124       --  Set SIGINT to unmasked state as long as it's
 125       --  not in "User" state.  Check for Unreserve_All_Interrupts last
 126
 127       if State (SIGINT) /= User then
 128          Keep_Unmasked (SIGINT) := True;
 129       end if;
 130
 131       --  Check all signals for state that requires keeping them
 132       --  unmasked and reserved
 133
 134       for J in Interrupt_ID'Range loop
 135          if State (J) = Default or else State (J) = Runtime then
 136             Keep_Unmasked (J) := True;
 137             Reserve (J) := True;
 138          end if;
 139       end loop;
 140
 141       --  Add target-specific reserved signals
 142
 143       for J in Reserved_Interrupts'Range loop
 144          Reserve (Interrupt_ID (Reserved_Interrupts (J))) := True;
 145       end loop;
 146
 147       --  Process pragma Unreserve_All_Interrupts. This overrides any
 148       --  settings due to pragma Interrupt_State:
 149
 150       if Unreserve_All_Interrupts /= 0 then
 151          Keep_Unmasked (SIGINT) := False;
 152          Reserve (SIGINT) := False;
 153       end if;
 154
 155       --  We do not have Signal 0 in reality. We just use this value
 156       --  to identify not existing signals (see s-intnam.ads). Therefore,
 157       --  Signal 0 should not be used in all signal related operations hence
 158       --  mark it as reserved.
 159
 160       Reserve (0) := True;
 161    end Initialize;
 162
 163 end System.Interrupt_Management;