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
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<title>Xenomai API: File descriptors events multiplexing services.</title>
<link href="doxygen.css" rel="stylesheet" type="text/css">
<link href="tabs.css" rel="stylesheet" type="text/css">
</head><body>
<!-- Generated by Doxygen 1.5.6 -->
<div class="navigation" id="top">
<div class="tabs">
<ul>
<li><a href="main.html"><span>Main Page</span></a></li>
<li><a href="pages.html"><span>Related Pages</span></a></li>
<li><a href="modules.html"><span>Modules</span></a></li>
<li><a href="annotated.html"><span>Data Structures</span></a></li>
<li><a href="files.html"><span>Files</span></a></li>
<li><a href="examples.html"><span>Examples</span></a></li>
<li>
<form action="search.php" method="get">
<table cellspacing="0" cellpadding="0" border="0">
<tr>
<td><label> <u>S</u>earch for </label></td>
<td><input type="text" name="query" value="" size="20" accesskey="s"/></td>
</tr>
</table>
</form>
</li>
</ul>
</div>
</div>
<div class="contents">
<h1>File descriptors events multiplexing services.<br>
<small>
[<a class="el" href="group__nucleus.html">Xenomai nucleus.</a>]</small>
</h1>
<p>
<div class="dynheader">
Collaboration diagram for File descriptors events multiplexing services.:</div>
<div class="dynsection">
<center><table><tr><td><img src="group__select.png" border="0" alt="" usemap="#group____select_map">
<map name="group____select_map">
<area shape="rect" href="group__nucleus.html" title="Xenomai nucleus." alt="" coords="5,5,141,32"></map></td></tr></table></center>
</div>
<hr><a name="_details"></a><h2>Detailed Description</h2>
File descriptors events multiplexing services.<p>
This module implements the services needed for implementing the posix "select" service, or any other events multiplexing services.<p>
Following the implementation of the posix select service, this module defines three types of events:<ul>
<li><em>XNSELECT_READ</em> meaning that a file descriptor is ready for reading;</li><li><em>XNSELECT_WRITE</em> meaning that a file descriptor is ready for writing;</li><li><em>XNSELECT_EXCEPT</em> meaning that a file descriptor received an exceptional event.</li></ul>
<p>
It works by defining two structures:<ul>
<li>a <em>struct</em> <em>xnselect</em> structure, which should be added to every file descriptor for every event type (read, write, or except);</li><li>a <em>struct</em> <em>xnselector</em> structure, the selection structure, passed by the thread calling the xnselect service, where this service does all its housekeeping. </li></ul>
<p>
<table border="0" cellpadding="0" cellspacing="0">
<tr><td></td></tr>
<tr><td colspan="2"><br><h2>Files</h2></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">file </td><td class="memItemRight" valign="bottom"><a class="el" href="select_8h.html">select.h</a></td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">file descriptors events multiplexing header. <br></td></tr>
<p>
<tr><td class="memItemLeft" nowrap align="right" valign="top">file </td><td class="memItemRight" valign="bottom"><a class="el" href="select_8c.html">select.c</a></td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">file descriptors events multiplexing. <br></td></tr>
<p>
<tr><td colspan="2"><br><h2>Functions</h2></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__select.html#g80b33cc02e860dc6ffbd08e8da376e5b">xnselect_init</a> (struct xnselect *select_block)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Initialize a <em>struct</em> <em>xnselect</em> structure. <a href="#g80b33cc02e860dc6ffbd08e8da376e5b"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__select.html#g8546a4a6f997a8c29451673d5b7f0e86">xnselect_bind</a> (struct xnselect *select_block, struct xnselect_binding *binding, struct xnselector *selector, unsigned type, unsigned index, unsigned state)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Bind a file descriptor (represented by its <em>xnselect</em> structure) to a selector block. <a href="#g8546a4a6f997a8c29451673d5b7f0e86"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__select.html#g56e4b5bf3e35dd80c23e95cad8fa1614">xnselect_destroy</a> (struct xnselect *select_block)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Destroy the <em>xnselect</em> structure associated with a file descriptor. <a href="#g56e4b5bf3e35dd80c23e95cad8fa1614"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__select.html#gf5576af13d5ffd6056311c2746a706a0">xnselector_init</a> (struct xnselector *selector)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Initialize a selector structure. <a href="#gf5576af13d5ffd6056311c2746a706a0"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__select.html#g4af23e0a42dbc61a04be36d5739a165f">xnselect</a> (struct xnselector *selector, fd_set *out_fds[XNSELECT_MAX_TYPES], fd_set *in_fds[XNSELECT_MAX_TYPES], int nfds, xnticks_t timeout, xntmode_t timeout_mode)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Check the state of a number of file descriptors, wait for a state change if no descriptor is ready. <a href="#g4af23e0a42dbc61a04be36d5739a165f"></a><br></td></tr>
<tr><td class="memItemLeft" nowrap align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__select.html#g9f4741ca8d6794f1b45478a24b1104de">xnselector_destroy</a> (struct xnselector *selector)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Destroy a selector block. <a href="#g9f4741ca8d6794f1b45478a24b1104de"></a><br></td></tr>
</table>
<hr><h2>Function Documentation</h2>
<a class="anchor" name="g4af23e0a42dbc61a04be36d5739a165f"></a><!-- doxytag: member="select.c::xnselect" ref="g4af23e0a42dbc61a04be36d5739a165f" args="(struct xnselector *selector, fd_set *out_fds[XNSELECT_MAX_TYPES], fd_set *in_fds[XNSELECT_MAX_TYPES], int nfds, xnticks_t timeout, xntmode_t timeout_mode)" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">int xnselect </td>
<td>(</td>
<td class="paramtype">struct xnselector * </td>
<td class="paramname"> <em>selector</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">fd_set * </td>
<td class="paramname"> <em>out_fds</em>[XNSELECT_MAX_TYPES], </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">fd_set * </td>
<td class="paramname"> <em>in_fds</em>[XNSELECT_MAX_TYPES], </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"> <em>nfds</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">xnticks_t </td>
<td class="paramname"> <em>timeout</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">xntmode_t </td>
<td class="paramname"> <em>timeout_mode</em></td><td> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Check the state of a number of file descriptors, wait for a state change if no descriptor is ready.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>selector</em> </td><td>structure to check for pending events </td></tr>
<tr><td valign="top"></td><td valign="top"><em>out_fds</em> </td><td>The set of descriptors with pending events if a strictly positive number is returned, or the set of descriptors not yet bound if -ECHRNG is returned; </td></tr>
<tr><td valign="top"></td><td valign="top"><em>in_fds</em> </td><td>the set of descriptors which events should be checked </td></tr>
<tr><td valign="top"></td><td valign="top"><em>nfds</em> </td><td>the highest-numbered descriptor in any of the <em>in_fds</em> sets, plus 1; </td></tr>
<tr><td valign="top"></td><td valign="top"><em>timeout</em> </td><td>the timeout, whose meaning depends on <em>timeout_mode</em>, note that <a class="el" href="group__select.html#g4af23e0a42dbc61a04be36d5739a165f" title="Check the state of a number of file descriptors, wait for a state change if no descriptor...">xnselect()</a> pass <em>timeout</em> and <em>timeout_mode</em> unchanged to xnsynch_sleep_on, so passing a relative value different from XN_INFINITE as a timeout with <em>timeout_mode</em> set to XN_RELATIVE, will cause a longer sleep than expected if the sleep is interrupted. </td></tr>
<tr><td valign="top"></td><td valign="top"><em>timeout_mode</em> </td><td>the mode of <em>timeout</em>.</td></tr>
</table>
</dl>
<dl compact><dt><b>Return values:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>-EINVAL</em> </td><td>if <em>nfds</em> is negative; </td></tr>
<tr><td valign="top"></td><td valign="top"><em>-ECHRNG</em> </td><td>if some of the descriptors passed in <em>in_fds</em> have not yet been registered with <a class="el" href="group__select.html#g8546a4a6f997a8c29451673d5b7f0e86" title="Bind a file descriptor (represented by its xnselect structure) to a selector block...">xnselect_bind()</a>, <em>out_fds</em> contains the set of such descriptors; </td></tr>
<tr><td valign="top"></td><td valign="top"><em>-EINTR</em> </td><td>if <em>xnselect</em> was interrupted while waiting; </td></tr>
<tr><td valign="top"></td><td valign="top"><em>0</em> </td><td>in case of timeout. </td></tr>
<tr><td valign="top"></td><td valign="top"><em>the</em> </td><td>number of file descriptors having received an event. </td></tr>
</table>
</dl>
<p>References <a class="el" href="include_2nucleus_2thread_8h-source.html#l00110">XNBREAK</a>, <a class="el" href="synch_8c-source.html#l00171">xnsynch_sleep_on()</a>, and <a class="el" href="include_2nucleus_2thread_8h-source.html#l00108">XNTIMEO</a>.</p>
</div>
</div><p>
<a class="anchor" name="g8546a4a6f997a8c29451673d5b7f0e86"></a><!-- doxytag: member="select.c::xnselect_bind" ref="g8546a4a6f997a8c29451673d5b7f0e86" args="(struct xnselect *select_block, struct xnselect_binding *binding, struct xnselector *selector, unsigned type, unsigned index, unsigned state)" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">int xnselect_bind </td>
<td>(</td>
<td class="paramtype">struct xnselect * </td>
<td class="paramname"> <em>select_block</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">struct xnselect_binding * </td>
<td class="paramname"> <em>binding</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">struct xnselector * </td>
<td class="paramname"> <em>selector</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">unsigned </td>
<td class="paramname"> <em>type</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">unsigned </td>
<td class="paramname"> <em>index</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">unsigned </td>
<td class="paramname"> <em>state</em></td><td> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Bind a file descriptor (represented by its <em>xnselect</em> structure) to a selector block.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>select_block</em> </td><td>pointer to the <em>struct</em> <em>xnselect</em> to be bound;</td></tr>
<tr><td valign="top"></td><td valign="top"><em>binding</em> </td><td>pointer to a newly allocated (using xnmalloc) <em>struct</em> <em>xnselect_binding</em>;</td></tr>
<tr><td valign="top"></td><td valign="top"><em>selector</em> </td><td>pointer to the selector structure;</td></tr>
<tr><td valign="top"></td><td valign="top"><em>type</em> </td><td>type of events (<em>XNSELECT_READ</em>, <em>XNSELECT_WRITE</em>, or <em>XNSELECT_EXCEPT</em>);</td></tr>
<tr><td valign="top"></td><td valign="top"><em>index</em> </td><td>index of the file descriptor (represented by <em>select_block</em>) in the bit fields used by the <em>selector</em> structure;</td></tr>
<tr><td valign="top"></td><td valign="top"><em>state</em> </td><td>current state of the file descriptor>.</td></tr>
</table>
</dl>
<em>select_block</em> must have been initialized with <a class="el" href="group__select.html#g80b33cc02e860dc6ffbd08e8da376e5b" title="Initialize a struct xnselect structure.">xnselect_init()</a>, the <em>xnselector</em> structure must have been initialized with <a class="el" href="group__select.html#gf5576af13d5ffd6056311c2746a706a0" title="Initialize a selector structure.">xnselector_init()</a>, <em>binding</em> may be uninitialized.<p>
This service must be called with nklock locked, irqs off. For this reason, the <em>binding</em> parameter must have been allocated by the caller outside the locking section.<p>
<dl compact><dt><b>Return values:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>-EINVAL</em> </td><td>if <em>type</em> or <em>index</em> is invalid; </td></tr>
<tr><td valign="top"></td><td valign="top"><em>0</em> </td><td>otherwise. </td></tr>
</table>
</dl>
<p>References <a class="el" href="pod_8h-source.html#l00251">xnpod_schedule()</a>.</p>
<p>Referenced by <a class="el" href="drvlib_8c-source.html#l01071">rtdm_event_select_bind()</a>, and <a class="el" href="drvlib_8c-source.html#l01353">rtdm_sem_select_bind()</a>.</p>
</div>
</div><p>
<a class="anchor" name="g56e4b5bf3e35dd80c23e95cad8fa1614"></a><!-- doxytag: member="select.c::xnselect_destroy" ref="g56e4b5bf3e35dd80c23e95cad8fa1614" args="(struct xnselect *select_block)" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void xnselect_destroy </td>
<td>(</td>
<td class="paramtype">struct xnselect * </td>
<td class="paramname"> <em>select_block</em> </td>
<td> ) </td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Destroy the <em>xnselect</em> structure associated with a file descriptor.
<p>
Any binding with a <em>xnselector</em> block is destroyed.<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>select_block</em> </td><td>pointer to the <em>xnselect</em> structure associated with a file descriptor </td></tr>
</table>
</dl>
<p>References <a class="el" href="pod_8h-source.html#l00251">xnpod_schedule()</a>.</p>
</div>
</div><p>
<a class="anchor" name="g80b33cc02e860dc6ffbd08e8da376e5b"></a><!-- doxytag: member="select.c::xnselect_init" ref="g80b33cc02e860dc6ffbd08e8da376e5b" args="(struct xnselect *select_block)" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void xnselect_init </td>
<td>(</td>
<td class="paramtype">struct xnselect * </td>
<td class="paramname"> <em>select_block</em> </td>
<td> ) </td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Initialize a <em>struct</em> <em>xnselect</em> structure.
<p>
This service must be called to initialize a <em>struct</em> <em>xnselect</em> structure before it is bound to a selector by the means of <a class="el" href="group__select.html#g8546a4a6f997a8c29451673d5b7f0e86" title="Bind a file descriptor (represented by its xnselect structure) to a selector block...">xnselect_bind()</a>.<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>select_block</em> </td><td>pointer to the xnselect structure to be initialized </td></tr>
</table>
</dl>
<p>Referenced by <a class="el" href="drvlib_8c-source.html#l00769">rtdm_event_init()</a>, and <a class="el" href="drvlib_8c-source.html#l01120">rtdm_sem_init()</a>.</p>
</div>
</div><p>
<a class="anchor" name="g9f4741ca8d6794f1b45478a24b1104de"></a><!-- doxytag: member="select.c::xnselector_destroy" ref="g9f4741ca8d6794f1b45478a24b1104de" args="(struct xnselector *selector)" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void xnselector_destroy </td>
<td>(</td>
<td class="paramtype">struct xnselector * </td>
<td class="paramname"> <em>selector</em> </td>
<td> ) </td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Destroy a selector block.
<p>
All bindings with file descriptor are destroyed.<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>selector</em> </td><td>the selector block to be destroyed </td></tr>
</table>
</dl>
<p>References <a class="el" href="generic_2hal_8c-source.html#l00601">rthal_apc_schedule()</a>.</p>
<p>Referenced by <a class="el" href="pod_8c-source.html#l01078">xnpod_delete_thread()</a>.</p>
</div>
</div><p>
<a class="anchor" name="gf5576af13d5ffd6056311c2746a706a0"></a><!-- doxytag: member="select.c::xnselector_init" ref="gf5576af13d5ffd6056311c2746a706a0" args="(struct xnselector *selector)" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">int xnselector_init </td>
<td>(</td>
<td class="paramtype">struct xnselector * </td>
<td class="paramname"> <em>selector</em> </td>
<td> ) </td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>
Initialize a selector structure.
<p>
<dl compact><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>selector</em> </td><td>The selector structure to be initialized.</td></tr>
</table>
</dl>
<dl compact><dt><b>Return values:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>0</em> </td><td></td></tr>
</table>
</dl>
<p>References <a class="el" href="synch_8c-source.html#l00102">xnsynch_init()</a>.</p>
</div>
</div><p>
</div>
<hr size="1"><address style="text-align: right;"><small>Generated on Mon Aug 2 12:48:38 2010 for Xenomai API by
<a href="http://www.doxygen.org/index.html">
<img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.5.6 </small></address>
</body>
</html>
|
