gcc/ada/s-intman-vxworks.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) 1992-2008, 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 the VxWorks version of this package
  35
  36 --  Make a careful study of all signals available under the OS, to see which
  37 --  need to be reserved, kept always unmasked, or kept always unmasked. Be on
  38 --  the lookout for special signals that may be used by the thread library.
  39
  40 package body System.Interrupt_Management is
  41
  42    use System.OS_Interface;
  43    use type Interfaces.C.int;
  44
  45    type Signal_List is array (Signal_ID range <>) of Signal_ID;
  46    Exception_Signals : constant Signal_List (1 .. 4) :=
  47                          (SIGFPE, SIGILL, SIGSEGV, SIGBUS);
  48
  49    Exception_Action : aliased struct_sigaction;
  50    --  Keep this variable global so that it is initialized only once
  51
  52    procedure Notify_Exception
  53      (signo      : Signal;
  54       siginfo    : System.Address;
  55       sigcontext : System.Address);
  56    pragma Import (C, Notify_Exception, "__gnat_error_handler");
  57    --  Map signal to Ada exception and raise it.  Different versions
  58    --  of VxWorks need different mappings.
  59
  60    -----------------------
  61    -- Local Subprograms --
  62    -----------------------
  63
  64    function State (Int : Interrupt_ID) return Character;
  65    pragma Import (C, State, "__gnat_get_interrupt_state");
  66    --  Get interrupt state. Defined in init.c The input argument is the
  67    --  interrupt number, and the result is one of the following:
  68
  69    Runtime : constant Character := 'r';
  70    Default : constant Character := 's';
  71    --    'n'   this interrupt not set by any Interrupt_State pragma
  72    --    'u'   Interrupt_State pragma set state to User
  73    --    'r'   Interrupt_State pragma set state to Runtime
  74    --    's'   Interrupt_State pragma set state to System (use "default"
  75    --           system handler)
  76
  77    ---------------------------
  78    -- Initialize_Interrupts --
  79    ---------------------------
  80
  81    --  Since there is no signal inheritance between VxWorks tasks, we need
  82    --  to initialize signal handling in each task.
  83
  84    procedure Initialize_Interrupts is
  85       Result  : int;
  86       old_act : aliased struct_sigaction;
  87    begin
  88       for J in Exception_Signals'Range loop
  89          Result :=
  90            sigaction
  91              (Signal (Exception_Signals (J)), Exception_Action'Access,
  92               old_act'Unchecked_Access);
  93          pragma Assert (Result = 0);
  94       end loop;
  95    end Initialize_Interrupts;
  96
  97    ----------------
  98    -- Initialize --
  99    ----------------
 100
 101    Initialized : Boolean := False;
 102    --  Set to True once Initialize is called, further calls have no effect
 103
 104    procedure Initialize is
 105       mask   : aliased sigset_t;
 106       Result : int;
 107
 108    begin
 109       if Initialized then
 110          return;
 111       end if;
 112
 113       Initialized := True;
 114
 115       --  Change this if you want to use another signal for task abort.
 116       --  SIGTERM might be a good one.
 117
 118       Abort_Task_Interrupt := SIGABRT;
 119
 120       Exception_Action.sa_handler := Notify_Exception'Address;
 121       Exception_Action.sa_flags := SA_ONSTACK + SA_SIGINFO;
 122       Result := sigemptyset (mask'Access);
 123       pragma Assert (Result = 0);
 124
 125       for J in Exception_Signals'Range loop
 126          Result := sigaddset (mask'Access, Signal (Exception_Signals (J)));
 127          pragma Assert (Result = 0);
 128       end loop;
 129
 130       Exception_Action.sa_mask := mask;
 131
 132       --  Initialize hardware interrupt handling
 133
 134       pragma Assert (Reserve = (Interrupt_ID'Range => False));
 135
 136       --  Check all interrupts for state that requires keeping them reserved
 137
 138       for J in Interrupt_ID'Range loop
 139          if State (J) = Default or else State (J) = Runtime then
 140             Reserve (J) := True;
 141          end if;
 142       end loop;
 143
 144       --  Add exception signals to the set of unmasked signals
 145
 146       for J in Exception_Signals'Range loop
 147          Keep_Unmasked (Exception_Signals (J)) := True;
 148       end loop;
 149
 150       --  The abort signal must also be unmasked
 151
 152       Keep_Unmasked (Abort_Task_Interrupt) := True;
 153    end Initialize;
 154
 155 end System.Interrupt_Management;