File : i-vxwoio.ads
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 -- --
19 -- --
20 -- --
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
42 with Interfaces.C_Streams;
43
44 package 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
229 end Interfaces.VxWorks.IO;