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------------------------------------------------------------------------------

--                                                                          --

--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --

--                                                                          --

--                 I N T E R F A C E S . V X W O R K S . I O                --

--                                                                          --

--                                  S p e c                                 --

--                                                                          --

--           Copyright (C) 2002-2009, Free Software Foundation, Inc.        --

--                                                                          --

-- GNARL is free software; you can  redistribute it  and/or modify it under --

-- terms of the  GNU General Public License as published  by the Free Soft- --

-- ware  Foundation;  either version 3,  or (at your option) any later ver- --

-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --

-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --

-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --

--                                                                          --

-- As a special exception under Section 7 of GPL version 3, you are granted --

-- additional permissions described in the GCC Runtime Library Exception,   --

-- version 3.1, as published by the Free Software Foundation.               --

--                                                                          --

-- You should have received a copy of the GNU General Public License and    --

-- a copy of the GCC Runtime Library Exception along with this program;     --

-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --

-- <http://www.gnu.org/licenses/>.                                          --

--                                                                          --

-- GNARL was developed by the GNARL team at Florida State University.       --

-- Extensive contributions were provided by Ada Core Technologies, Inc.     --

--                                                                          --

------------------------------------------------------------------------------

--  This package provides a binding to the functions fileno and ioctl

--  in VxWorks, providing a set of definitions of ioctl function codes

--  and options for the use of these functions.

--  A particular use of this interface is to enable use of Get_Immediate

--  in Ada.Text_IO. There is no way in VxWorks to provide the desired

--  functionality of Get_Immediate (no buffering and no waiting for a

--  line return) without flushing the buffer, which violates the Ada

--  semantic requirements for Ada.Text_IO.

with Interfaces.C_Streams;

package Interfaces.VxWorks.IO is

   -------------------------

   -- The ioctl Interface --

   --------------------------

   type FUNCODE is new int;

   --  Type of the function codes in ioctl

   type IOOPT is mod 2 ** int'Size;

   --  Type of the option codes in ioctl

   --  ioctl function codes (for more information see ioLib.h)

   --  These values could be generated automatically in System.OS_Constants???

   FIONREAD       : constant FUNCODE := 1;

   FIOFLUSH       : constant FUNCODE := 2;

   FIOOPTIONS     : constant FUNCODE := 3;

   FIOBAUDRATE    : constant FUNCODE := 4;

   FIODISKFORMAT  : constant FUNCODE := 5;

   FIODISKINIT    : constant FUNCODE := 6;

   FIOSEEK        : constant FUNCODE := 7;

   FIOWHERE       : constant FUNCODE := 8;

   FIODIRENTRY    : constant FUNCODE := 9;

   FIORENAME      : constant FUNCODE := 10;

   FIOREADYCHANGE : constant FUNCODE := 11;

   FIONWRITE      : constant FUNCODE := 12;

   FIODISKCHANGE  : constant FUNCODE := 13;

   FIOCANCEL      : constant FUNCODE := 14;

   FIOSQUEEZE     : constant FUNCODE := 15;

   FIONBIO        : constant FUNCODE := 16;

   FIONMSGS       : constant FUNCODE := 17;

   FIOGETNAME     : constant FUNCODE := 18;

   FIOGETOPTIONS  : constant FUNCODE := 19;

   FIOSETOPTIONS  : constant FUNCODE := FIOOPTIONS;

   FIOISATTY      : constant FUNCODE := 20;

   FIOSYNC        : constant FUNCODE := 21;

   FIOPROTOHOOK   : constant FUNCODE := 22;

   FIOPROTOARG    : constant FUNCODE := 23;

   FIORBUFSET     : constant FUNCODE := 24;

   FIOWBUFSET     : constant FUNCODE := 25;

   FIORFLUSH      : constant FUNCODE := 26;

   FIOWFLUSH      : constant FUNCODE := 27;

   FIOSELECT      : constant FUNCODE := 28;

   FIOUNSELECT    : constant FUNCODE := 29;

   FIONFREE       : constant FUNCODE := 30;

   FIOMKDIR       : constant FUNCODE := 31;

   FIORMDIR       : constant FUNCODE := 32;

   FIOLABELGET    : constant FUNCODE := 33;

   FIOLABELSET    : constant FUNCODE := 34;

   FIOATTRIBSE    : constant FUNCODE := 35;

   FIOCONTIG      : constant FUNCODE := 36;

   FIOREADDIR     : constant FUNCODE := 37;

   FIOFSTATGET    : constant FUNCODE := 38;

   FIOUNMOUNT     : constant FUNCODE := 39;

   FIOSCSICOMMAND : constant FUNCODE := 40;

   FIONCONTIG     : constant FUNCODE := 41;

   FIOTRUNC       : constant FUNCODE := 42;

   FIOGETFL       : constant FUNCODE := 43;

   FIOTIMESET     : constant FUNCODE := 44;

   FIOINODETONAM  : constant FUNCODE := 45;

   FIOFSTATFSGE   : constant FUNCODE := 46;

   --  ioctl option values

   OPT_ECHO     : constant IOOPT := 16#0001#;

   OPT_CRMOD    : constant IOOPT := 16#0002#;

   OPT_TANDEM   : constant IOOPT := 16#0004#;

   OPT_7_BIT    : constant IOOPT := 16#0008#;

   OPT_MON_TRAP : constant IOOPT := 16#0010#;

   OPT_ABORT    : constant IOOPT := 16#0020#;

   OPT_LINE     : constant IOOPT := 16#0040#;

   OPT_RAW      : constant IOOPT := 16#0000#;

   OPT_TERMINAL : constant IOOPT := OPT_ECHO     or

                                    OPT_CRMOD    or

                                    OPT_TANDEM   or

                                    OPT_MON_TRAP or

                                    OPT_7_BIT    or

                                    OPT_ABORT    or

                                    OPT_LINE;

   function fileno (Fp : Interfaces.C_Streams.FILEs) return int;

   pragma Import (C, fileno, "fileno");

   --  Binding to the C routine fileno

   function ioctl (Fd : int; Function_Code : FUNCODE; Arg : IOOPT) return int;

   pragma Import (C, ioctl, "ioctl");

   --  Binding to the C routine ioctl

   --

   --  Note: we are taking advantage of the fact that on currently supported

   --  VxWorks targets, it is fine to directly bind to a variadic C function.

   ------------------------------

   -- Control of Get_Immediate --

   ------------------------------

   --  The procedures in this section make use of the interface to ioctl

   --  and fileno to provide a mechanism for enabling unbuffered behavior

   --  for Get_Immediate in VxWorks.

   --  The situation is that the RM requires that the use of Get_Immediate

   --  be identical to Get except that it is desirable (not required) that

   --  there be no buffering or line editing.

   --  Unfortunately, in VxWorks, the only way to enable this desired

   --  unbuffered behavior involves changing into raw mode. But this

   --  transition into raw mode flushes the input buffer, a behavior

   --  not permitted by the RM semantics for Get_Immediate.

   --  Given that Get_Immediate cannot be accurately implemented in

   --  raw mode, it seems best not to enable it by default, and instead

   --  to require specific programmer action, with the programmer being

   --  aware that input may be lost.

   --  The following is an example of the use of the two procedures

   --  in this section (Enable_Get_Immediate and Disable_Get_Immediate)

   --  with Ada.Text_IO; use Ada.Text_IO;

   --  with Ada.Text_IO.C_Streams; use Ada.Text_IO.C_Streams;

   --  with Interfaces.VxWorks.IO; use Interfaces.VxWorks.IO;

   --  procedure Example_IO is

   --     Input     : Character;

   --     Available : Boolean;

   --     Success   : Boolean;

   --  begin

   --     Enable_Get_Immediate (C_Stream (Current_Input), Success);

   --     if Success = False then

   --        raise Device_Error;

   --     end if;

   --     --  Example with the first type of Get_Immediate

   --     --  Waits for an entry on the input. Immediately returns

   --     --  after having received an character on the input

   --     Put ("Input -> ");

   --     Get_Immediate (Input);

   --     New_Line;

   --     Put_Line ("Character read: " & Input);

   --     --  Example with the second type of Get_Immediate

   --     --  This is equivalent to a non blocking read

   --     for J in 1 .. 10 loop

   --        Put ("Input -> ");

   --        Get_Immediate (Input, Available);

   --        New_Line;

   --        if Available = True then

   --           Put_Line ("Character read: " & Input);

   --        end if;

   --        delay 1.0;

   --     end loop;

   --     Disable_Get_Immediate (C_Stream (Current_Input), Success);

   --     if Success = False then

   --        raise Device_Error;

   --     end if;

   --  exception

   --     when Device_Error =>

   --        Put_Line ("Device Error. Check your configuration");

   --  end Example_IO;

   procedure Enable_Get_Immediate

     (File    : Interfaces.C_Streams.FILEs;

      Success : out Boolean);

   --  On VxWorks, a call to this procedure is required before subsequent calls

   --  to Get_Immediate have the desired effect of not waiting for a line

   --  return. The reason that this call is not automatic on this target is

   --  that the call flushes the input buffer, discarding any previous input.

   --  Note: Following a call to Enable_Get_Immediate, the only permitted

   --  operations on the relevant file are Get_Immediate operations. Any

   --  other operations have undefined behavior.

   procedure Disable_Get_Immediate

     (File    : Interfaces.C_Streams.FILEs;

      Success : out Boolean);

   --  This procedure resets File to standard mode, and permits subsequent

   --  use of the full range of Ada.Text_IO functions

end Interfaces.VxWorks.IO;