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) 1992-2006 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- --
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  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,
  37 --  to see which need to be reserved, kept always unmasked,
  38 --  or kept always unmasked.
  39 --  Be on the lookout for special signals that
  40 --  may be used by the thread library.
  41
  42 package body System.Interrupt_Management is
  43
  44    use System.OS_Interface;
  45    use type Interfaces.C.int;
  46
  47    type Signal_List is array (Signal_ID range <>) of Signal_ID;
  48    Exception_Signals : constant Signal_List (1 .. 4) :=
  49                          (SIGFPE, SIGILL, SIGSEGV, SIGBUS);
  50
  51    Exception_Action : aliased struct_sigaction;
  52    --  Keep this variable global so that it is initialized only once
  53
  54    procedure Map_And_Raise_Exception (signo : Signal);
  55    pragma Import (C, Map_And_Raise_Exception, "__gnat_map_signal");
  56    --  Map signal to Ada exception and raise it.  Different versions
  57    --  of VxWorks need different mappings.
  58
  59    -----------------------
  60    -- Local Subprograms --
  61    -----------------------
  62
  63    function State (Int : Interrupt_ID) return Character;
  64    pragma Import (C, State, "__gnat_get_interrupt_state");
  65    --  Get interrupt state.  Defined in init.c
  66    --  The input argument is the interrupt number,
  67    --  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    procedure Notify_Exception (signo : Signal);
  78    --  Identify the Ada exception to be raised using
  79    --  the information when the system received a synchronous signal.
  80
  81    ----------------------
  82    -- Notify_Exception --
  83    ----------------------
  84
  85    procedure Notify_Exception (signo : Signal) is
  86       Mask   : aliased sigset_t;
  87
  88       Result : int;
  89       pragma Unreferenced (Result);
  90
  91    begin
  92       Result := pthread_sigmask (SIG_SETMASK, null, Mask'Unchecked_Access);
  93       Result := sigdelset (Mask'Access, signo);
  94       Result := pthread_sigmask (SIG_SETMASK, Mask'Unchecked_Access, null);
  95
  96       Map_And_Raise_Exception (signo);
  97    end Notify_Exception;
  98
  99    ---------------------------
 100    -- Initialize_Interrupts --
 101    ---------------------------
 102
 103    --  Since there is no signal inheritance between VxWorks tasks, we need
 104    --  to initialize signal handling in each task.
 105
 106    procedure Initialize_Interrupts is
 107       Result  : int;
 108       old_act : aliased struct_sigaction;
 109    begin
 110       for J in Exception_Signals'Range loop
 111          Result :=
 112            sigaction
 113              (Signal (Exception_Signals (J)), Exception_Action'Access,
 114               old_act'Unchecked_Access);
 115          pragma Assert (Result = 0);
 116       end loop;
 117    end Initialize_Interrupts;
 118
 119    ----------------
 120    -- Initialize --
 121    ----------------
 122
 123    Initialized : Boolean := False;
 124
 125    procedure Initialize is
 126       mask   : aliased sigset_t;
 127       Result : int;
 128    begin
 129       if Initialized then
 130          return;
 131       end if;
 132
 133       Initialized := True;
 134
 135       --  Change this if you want to use another signal for task abort.
 136       --  SIGTERM might be a good one.
 137
 138       Abort_Task_Signal := SIGABRT;
 139
 140       Exception_Action.sa_handler := Notify_Exception'Address;
 141       Exception_Action.sa_flags := SA_ONSTACK;
 142       Result := sigemptyset (mask'Access);
 143       pragma Assert (Result = 0);
 144
 145       for J in Exception_Signals'Range loop
 146          Result := sigaddset (mask'Access, Signal (Exception_Signals (J)));
 147          pragma Assert (Result = 0);
 148       end loop;
 149
 150       Exception_Action.sa_mask := mask;
 151
 152       --  Initialize hardware interrupt handling
 153
 154       pragma Assert (Reserve = (Interrupt_ID'Range => False));
 155
 156       --  Check all interrupts for state that requires keeping them reserved
 157
 158       for J in Interrupt_ID'Range loop
 159          if State (J) = Default or else State (J) = Runtime then
 160             Reserve (J) := True;
 161          end if;
 162       end loop;
 163
 164       --  Add exception signals to the set of unmasked signals
 165
 166       for J in Exception_Signals'Range loop
 167          Keep_Unmasked (Exception_Signals (J)) := True;
 168       end loop;
 169
 170       --  The abort signal must also be unmasked
 171
 172       Keep_Unmasked (Abort_Task_Signal) := True;
 173    end Initialize;
 174
 175 end System.Interrupt_Management;