1------------------------------------------------------------------------------
2--                                                                          --
3--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
4--                                                                          --
5--                 I N T E R F A C E S . V X W O R K S . I O                --
6--                                                                          --
7--                                  S p e c                                 --
8--                                                                          --
9--           Copyright (C) 2002-2009, 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 package provides a binding to the functions fileno and ioctl
33--  in VxWorks, providing a set of definitions of ioctl function codes
34--  and options for the use of these functions.
35
36--  A particular use of this interface is to enable use of Get_Immediate
37--  in Ada.Text_IO. There is no way in VxWorks to provide the desired
38--  functionality of Get_Immediate (no buffering and no waiting for a
39--  line return) without flushing the buffer, which violates the Ada
40--  semantic requirements for Ada.Text_IO.
41
42with Interfaces.C_Streams;
43
44package Interfaces.VxWorks.IO is
45
46   -------------------------
47   -- The ioctl Interface --
48   --------------------------
49
50   type FUNCODE is new int;
51   --  Type of the function codes in ioctl
52
53   type IOOPT is mod 2 ** int'Size;
54   --  Type of the option codes in ioctl
55
56   --  ioctl function codes (for more information see ioLib.h)
57   --  These values could be generated automatically in System.OS_Constants???
58
59   FIONREAD       : constant FUNCODE := 1;
60   FIOFLUSH       : constant FUNCODE := 2;
61   FIOOPTIONS     : constant FUNCODE := 3;
62   FIOBAUDRATE    : constant FUNCODE := 4;
63   FIODISKFORMAT  : constant FUNCODE := 5;
64   FIODISKINIT    : constant FUNCODE := 6;
65   FIOSEEK        : constant FUNCODE := 7;
66   FIOWHERE       : constant FUNCODE := 8;
67   FIODIRENTRY    : constant FUNCODE := 9;
68   FIORENAME      : constant FUNCODE := 10;
69   FIOREADYCHANGE : constant FUNCODE := 11;
70   FIONWRITE      : constant FUNCODE := 12;
71   FIODISKCHANGE  : constant FUNCODE := 13;
72   FIOCANCEL      : constant FUNCODE := 14;
73   FIOSQUEEZE     : constant FUNCODE := 15;
74   FIONBIO        : constant FUNCODE := 16;
75   FIONMSGS       : constant FUNCODE := 17;
76   FIOGETNAME     : constant FUNCODE := 18;
77   FIOGETOPTIONS  : constant FUNCODE := 19;
78   FIOSETOPTIONS  : constant FUNCODE := FIOOPTIONS;
79   FIOISATTY      : constant FUNCODE := 20;
80   FIOSYNC        : constant FUNCODE := 21;
81   FIOPROTOHOOK   : constant FUNCODE := 22;
82   FIOPROTOARG    : constant FUNCODE := 23;
83   FIORBUFSET     : constant FUNCODE := 24;
84   FIOWBUFSET     : constant FUNCODE := 25;
85   FIORFLUSH      : constant FUNCODE := 26;
86   FIOWFLUSH      : constant FUNCODE := 27;
87   FIOSELECT      : constant FUNCODE := 28;
88   FIOUNSELECT    : constant FUNCODE := 29;
89   FIONFREE       : constant FUNCODE := 30;
90   FIOMKDIR       : constant FUNCODE := 31;
91   FIORMDIR       : constant FUNCODE := 32;
92   FIOLABELGET    : constant FUNCODE := 33;
93   FIOLABELSET    : constant FUNCODE := 34;
94   FIOATTRIBSE    : constant FUNCODE := 35;
95   FIOCONTIG      : constant FUNCODE := 36;
96   FIOREADDIR     : constant FUNCODE := 37;
97   FIOFSTATGET    : constant FUNCODE := 38;
98   FIOUNMOUNT     : constant FUNCODE := 39;
99   FIOSCSICOMMAND : constant FUNCODE := 40;
100   FIONCONTIG     : constant FUNCODE := 41;
101   FIOTRUNC       : constant FUNCODE := 42;
102   FIOGETFL       : constant FUNCODE := 43;
103   FIOTIMESET     : constant FUNCODE := 44;
104   FIOINODETONAM  : constant FUNCODE := 45;
105   FIOFSTATFSGE   : constant FUNCODE := 46;
106
107   --  ioctl option values
108
109   OPT_ECHO     : constant IOOPT := 16#0001#;
110   OPT_CRMOD    : constant IOOPT := 16#0002#;
111   OPT_TANDEM   : constant IOOPT := 16#0004#;
112   OPT_7_BIT    : constant IOOPT := 16#0008#;
113   OPT_MON_TRAP : constant IOOPT := 16#0010#;
114   OPT_ABORT    : constant IOOPT := 16#0020#;
115   OPT_LINE     : constant IOOPT := 16#0040#;
116   OPT_RAW      : constant IOOPT := 16#0000#;
117   OPT_TERMINAL : constant IOOPT := OPT_ECHO     or
118                                    OPT_CRMOD    or
119                                    OPT_TANDEM   or
120                                    OPT_MON_TRAP or
121                                    OPT_7_BIT    or
122                                    OPT_ABORT    or
123                                    OPT_LINE;
124
125   function fileno (Fp : Interfaces.C_Streams.FILEs) return int;
126   pragma Import (C, fileno, "fileno");
127   --  Binding to the C routine fileno
128
129   function ioctl (Fd : int; Function_Code : FUNCODE; Arg : IOOPT) return int;
130   pragma Import (C, ioctl, "ioctl");
131   --  Binding to the C routine ioctl
132   --
133   --  Note: we are taking advantage of the fact that on currently supported
134   --  VxWorks targets, it is fine to directly bind to a variadic C function.
135
136   ------------------------------
137   -- Control of Get_Immediate --
138   ------------------------------
139
140   --  The procedures in this section make use of the interface to ioctl
141   --  and fileno to provide a mechanism for enabling unbuffered behavior
142   --  for Get_Immediate in VxWorks.
143
144   --  The situation is that the RM requires that the use of Get_Immediate
145   --  be identical to Get except that it is desirable (not required) that
146   --  there be no buffering or line editing.
147
148   --  Unfortunately, in VxWorks, the only way to enable this desired
149   --  unbuffered behavior involves changing into raw mode. But this
150   --  transition into raw mode flushes the input buffer, a behavior
151   --  not permitted by the RM semantics for Get_Immediate.
152
153   --  Given that Get_Immediate cannot be accurately implemented in
154   --  raw mode, it seems best not to enable it by default, and instead
155   --  to require specific programmer action, with the programmer being
156   --  aware that input may be lost.
157
158   --  The following is an example of the use of the two procedures
159   --  in this section (Enable_Get_Immediate and Disable_Get_Immediate)
160
161   --  with Ada.Text_IO; use Ada.Text_IO;
162   --  with Ada.Text_IO.C_Streams; use Ada.Text_IO.C_Streams;
163   --  with Interfaces.VxWorks.IO; use Interfaces.VxWorks.IO;
164
165   --  procedure Example_IO is
166   --     Input     : Character;
167   --     Available : Boolean;
168   --     Success   : Boolean;
169
170   --  begin
171   --     Enable_Get_Immediate (C_Stream (Current_Input), Success);
172
173   --     if Success = False then
174   --        raise Device_Error;
175   --     end if;
176
177   --     --  Example with the first type of Get_Immediate
178   --     --  Waits for an entry on the input. Immediately returns
179   --     --  after having received an character on the input
180
181   --     Put ("Input -> ");
182   --     Get_Immediate (Input);
183   --     New_Line;
184   --     Put_Line ("Character read: " & Input);
185
186   --     --  Example with the second type of Get_Immediate
187   --     --  This is equivalent to a non blocking read
188
189   --     for J in 1 .. 10 loop
190   --        Put ("Input -> ");
191   --        Get_Immediate (Input, Available);
192   --        New_Line;
193
194   --        if Available = True then
195   --           Put_Line ("Character read: " & Input);
196   --        end if;
197
198   --        delay 1.0;
199   --     end loop;
200
201   --     Disable_Get_Immediate (C_Stream (Current_Input), Success);
202
203   --     if Success = False then
204   --        raise Device_Error;
205   --     end if;
206
207   --  exception
208   --     when Device_Error =>
209   --        Put_Line ("Device Error. Check your configuration");
210   --  end Example_IO;
211
212   procedure Enable_Get_Immediate
213     (File    : Interfaces.C_Streams.FILEs;
214      Success : out Boolean);
215   --  On VxWorks, a call to this procedure is required before subsequent calls
216   --  to Get_Immediate have the desired effect of not waiting for a line
217   --  return. The reason that this call is not automatic on this target is
218   --  that the call flushes the input buffer, discarding any previous input.
219   --  Note: Following a call to Enable_Get_Immediate, the only permitted
220   --  operations on the relevant file are Get_Immediate operations. Any
221   --  other operations have undefined behavior.
222
223   procedure Disable_Get_Immediate
224     (File    : Interfaces.C_Streams.FILEs;
225      Success : out Boolean);
226   --  This procedure resets File to standard mode, and permits subsequent
227   --  use of the full range of Ada.Text_IO functions
228
229end Interfaces.VxWorks.IO;
230