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) 1992-2009, 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 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT 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.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNARL was developed by the GNARL team at Florida State University.       --
  28 -- Extensive contributions were provided by Ada Core Technologies, Inc.     --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 --  This is the VxWorks version of this package
  33
  34 --  Make a careful study of all signals available under the OS, to see which
  35 --  need to be reserved, kept always unmasked, or kept always unmasked. Be on
  36 --  the lookout for special signals that may be used by the thread library.
  37
  38 package body System.Interrupt_Management is
  39
  40    use System.OS_Interface;
  41    use type Interfaces.C.int;
  42
  43    type Signal_List is array (Signal_ID range <>) of Signal_ID;
  44    Exception_Signals : constant Signal_List (1 .. 4) :=
  45                          (SIGFPE, SIGILL, SIGSEGV, SIGBUS);
  46
  47    Exception_Action : aliased struct_sigaction;
  48    --  Keep this variable global so that it is initialized only once
  49
  50    procedure Notify_Exception
  51      (signo      : Signal;
  52       siginfo    : System.Address;
  53       sigcontext : System.Address);
  54    pragma Import (C, Notify_Exception, "__gnat_error_handler");
  55    --  Map signal to Ada exception and raise it.  Different versions
  56    --  of VxWorks need different mappings.
  57
  58    -----------------------
  59    -- Local Subprograms --
  60    -----------------------
  61
  62    function State (Int : Interrupt_ID) return Character;
  63    pragma Import (C, State, "__gnat_get_interrupt_state");
  64    --  Get interrupt state. Defined in init.c The input argument is the
  65    --  interrupt number, and the result is one of the following:
  66
  67    Runtime : constant Character := 'r';
  68    Default : constant Character := 's';
  69    --    'n'   this interrupt not set by any Interrupt_State pragma
  70    --    'u'   Interrupt_State pragma set state to User
  71    --    'r'   Interrupt_State pragma set state to Runtime
  72    --    's'   Interrupt_State pragma set state to System (use "default"
  73    --           system handler)
  74
  75    ---------------------------
  76    -- Initialize_Interrupts --
  77    ---------------------------
  78
  79    --  Since there is no signal inheritance between VxWorks tasks, we need
  80    --  to initialize signal handling in each task.
  81
  82    procedure Initialize_Interrupts is
  83       Result  : int;
  84       old_act : aliased struct_sigaction;
  85    begin
  86       for J in Exception_Signals'Range loop
  87          Result :=
  88            sigaction
  89              (Signal (Exception_Signals (J)), Exception_Action'Access,
  90               old_act'Unchecked_Access);
  91          pragma Assert (Result = 0);
  92       end loop;
  93    end Initialize_Interrupts;
  94
  95    ----------------
  96    -- Initialize --
  97    ----------------
  98
  99    Initialized : Boolean := False;
 100    --  Set to True once Initialize is called, further calls have no effect
 101
 102    procedure Initialize is
 103       mask   : aliased sigset_t;
 104       Result : int;
 105
 106    begin
 107       if Initialized then
 108          return;
 109       end if;
 110
 111       Initialized := True;
 112
 113       --  Change this if you want to use another signal for task abort.
 114       --  SIGTERM might be a good one.
 115
 116       Abort_Task_Interrupt := SIGABRT;
 117
 118       Exception_Action.sa_handler := Notify_Exception'Address;
 119       Exception_Action.sa_flags := SA_ONSTACK + SA_SIGINFO;
 120       Result := sigemptyset (mask'Access);
 121       pragma Assert (Result = 0);
 122
 123       for J in Exception_Signals'Range loop
 124          Result := sigaddset (mask'Access, Signal (Exception_Signals (J)));
 125          pragma Assert (Result = 0);
 126       end loop;
 127
 128       Exception_Action.sa_mask := mask;
 129
 130       --  Initialize hardware interrupt handling
 131
 132       pragma Assert (Reserve = (Interrupt_ID'Range => False));
 133
 134       --  Check all interrupts for state that requires keeping them reserved
 135
 136       for J in Interrupt_ID'Range loop
 137          if State (J) = Default or else State (J) = Runtime then
 138             Reserve (J) := True;
 139          end if;
 140       end loop;
 141
 142       --  Add exception signals to the set of unmasked signals
 143
 144       for J in Exception_Signals'Range loop
 145          Keep_Unmasked (Exception_Signals (J)) := True;
 146       end loop;
 147
 148       --  The abort signal must also be unmasked
 149
 150       Keep_Unmasked (Abort_Task_Interrupt) := True;
 151    end Initialize;
 152
 153 end System.Interrupt_Management;