1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
<HTML
><HEAD
><TITLE
>rtf_put</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.64
"></HEAD
><BODY
CLASS="REFENTRY"
><H1
><A
NAME="AEN1"
>rtf_put</A
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN5"
></A
><H2
>Name</H2
>rtf_put -- write data to a realtime fifo</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN8"
></A
><H2
>Synopsis</H2
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="SYNOPSIS"
> #include <rtl_fifo.h>
int <TT
CLASS="FUNCTION"
>rtf_put</TT
>(unsigned int <TT
CLASS="PARAMETER"
><I
>fifo</I
></TT
>, char * <TT
CLASS="PARAMETER"
><I
>buf</I
></TT
>, int <TT
CLASS="PARAMETER"
><I
>count</I
></TT
>); </PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN14"
></A
><H2
>DESCRIPTION</H2
><P
><TT
CLASS="FUNCTION"
>rtf_put</TT
> writes a block of data to a realtime fifo (RT-FIFO) previously created with a call to <TT
CLASS="FUNCTION"
>rtf_create(3)</TT
>. <TT
CLASS="PARAMETER"
><I
>fifo</I
></TT
> is the ID with which the RT-FIFO was created. <TT
CLASS="PARAMETER"
><I
>buf</I
></TT
> is the block of data to be filled with the received bytes, while <TT
CLASS="PARAMETER"
><I
>count</I
></TT
> is the size of the block in bytes. This mechanism is available only to realtime tasks; Linux processes use a <TT
CLASS="FUNCTION"
>write(2)</TT
> to the corresponding fifo device to enqueue data to a fifo. Similarly, Linux processes use <TT
CLASS="FUNCTION"
>read(2)</TT
> or similar functions to read the data previously written via <TT
CLASS="FUNCTION"
>rtf_put</TT
> by a realtime task.</P
><P
>The RT-FIFO is a mechanism, implemented as a character device, to communicate between realtime tasks and ordinary Linux processes. The rtf_* functions are used by the realtime tasks; Linux processes use standard character device access functions such as <TT
CLASS="FUNCTION"
>read(2)</TT
>, <TT
CLASS="FUNCTION"
>write(2</TT
>) and <TT
CLASS="FUNCTION"
>select(2)</TT
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN29"
></A
><H2
>RETURN VALUE</H2
><P
>On success, <TT
CLASS="PARAMETER"
><I
>count</I
></TT
> is returned. On failure, a
negative value is returned as described below.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN33"
></A
><H2
>ERRORS</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
>-ENODEV</DT
><DD
><P
><TT
CLASS="PARAMETER"
><I
>fifo</I
></TT
> is greater than or equal to RTF_NO.</P
></DD
><DT
>-EINVAL</DT
><DD
><P
><TT
CLASS="PARAMETER"
><I
>fifo</I
></TT
> is not a valid RT-FIFO identifier.</P
></DD
><DT
>-ENOSPC</DT
><DD
><P
>insufficient space is available in the RT-FIFO for <TT
CLASS="PARAMETER"
><I
>count</I
></TT
> bytes.</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN51"
></A
><H2
>Notes</H2
><P
><TT
CLASS="FUNCTION"
>rtf_put</TT
> is available in PSC, the user-level
real-time signal library. It can be called from handlers installed via
<A
HREF="rtlinux_sigaction.3.html"
TARGET="_top"
>rtlinux_sigaction(3)</A
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN56"
></A
><H2
>SEE ALSO</H2
><A
HREF="../susv2/xns/read.html"
TARGET="_top"
>UNIX spec read(2)</A
>, <A
HREF="rtf_create.3.html"
TARGET="_top"
>rtf_create(3)</A
>, <A
HREF="rtf_create_handler.3.html"
TARGET="_top"
>rtf_create_handler(3)</A
>, <A
HREF="rtf_destroy.3.html"
TARGET="_top"
>rtf_destroy(3)</A
>, <A
HREF="rtf_get.3.html"
TARGET="_top"
>rtf_get(3)</A
>, <A
HREF="../susv2/xns/write.html"
TARGET="_top"
>UNIX spec write(2)</A
><P
>1997 Jerry Epplin.</P
><P
>Modifications for RTLinux 2.x and 3.x by Michael Barabanov. 2001 FSMLabs Inc.</P
><P
>All rights reserved.</P
></DIV
></BODY
></HTML
>
|
