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
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>Class environment</title>
<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset">
<link rel="up" href="../../mpi/reference.html#header.boost.mpi.environment_hpp" title="Header <boost/mpi/environment.hpp>">
<link rel="prev" href="threading/operator_idm46563252358416.html" title="Function operator>>">
<link rel="next" href="exception.html" title="Class exception">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td>
<td align="center"><a href="../../../../index.html">Home</a></td>
<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="../../../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="threading/operator_idm46563252358416.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../mpi/reference.html#header.boost.mpi.environment_hpp"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="exception.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="refentry">
<a name="boost.mpi.environment"></a><div class="titlepage"></div>
<div class="refnamediv">
<h2><span class="refentrytitle">Class environment</span></h2>
<p>boost::mpi::environment — Initialize, finalize, and query the MPI environment. </p>
</div>
<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2>
<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../mpi/reference.html#header.boost.mpi.environment_hpp" title="Header <boost/mpi/environment.hpp>">boost/mpi/environment.hpp</a>>
</span>
<span class="keyword">class</span> <a class="link" href="environment.html" title="Class environment">environment</a> <span class="special">:</span> <span class="keyword">private</span> <span class="identifier">noncopyable</span> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
<span class="comment">// <a class="link" href="environment.html#boost.mpi.environmentconstruct-copy-destruct">construct/copy/destruct</a></span>
<span class="keyword">explicit</span> <a class="link" href="environment.html#idm46563252434912-bb"><span class="identifier">environment</span></a><span class="special">(</span><span class="keyword">bool</span> <span class="special">=</span> <span class="keyword">true</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">explicit</span> <a class="link" href="environment.html#idm46563252428960-bb"><span class="identifier">environment</span></a><span class="special">(</span><span class="identifier">threading</span><span class="special">::</span><span class="identifier">level</span><span class="special">,</span> <span class="keyword">bool</span> <span class="special">=</span> <span class="keyword">true</span><span class="special">)</span><span class="special">;</span>
<a class="link" href="environment.html#idm46563252421872-bb"><span class="identifier">environment</span></a><span class="special">(</span><span class="keyword">int</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">char</span> <span class="special">*</span><span class="special">*</span><span class="special">&</span><span class="special">,</span> <span class="keyword">bool</span> <span class="special">=</span> <span class="keyword">true</span><span class="special">)</span><span class="special">;</span>
<a class="link" href="environment.html#idm46563252414944-bb"><span class="identifier">environment</span></a><span class="special">(</span><span class="keyword">int</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">char</span> <span class="special">*</span><span class="special">*</span><span class="special">&</span><span class="special">,</span> <span class="identifier">threading</span><span class="special">::</span><span class="identifier">level</span><span class="special">,</span> <span class="keyword">bool</span> <span class="special">=</span> <span class="keyword">true</span><span class="special">)</span><span class="special">;</span>
<a class="link" href="environment.html#idm46563252406896-bb"><span class="special">~</span><span class="identifier">environment</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="comment">// <a class="link" href="environment.html#idm46563252402832-bb">public static functions</a></span>
<span class="keyword">static</span> <span class="keyword">void</span> <a class="link" href="environment.html#idm46563252402272-bb"><span class="identifier">abort</span></a><span class="special">(</span><span class="keyword">int</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">bool</span> <a class="link" href="environment.html#idm46563252397552-bb"><span class="identifier">initialized</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">bool</span> <a class="link" href="environment.html#idm46563252394176-bb"><span class="identifier">finalized</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">int</span> <a class="link" href="environment.html#idm46563252390816-bb"><span class="identifier">max_tag</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">int</span> <a class="link" href="environment.html#idm46563252387200-bb"><span class="identifier">collectives_tag</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">static</span> <span class="identifier">optional</span><span class="special"><</span> <span class="keyword">int</span> <span class="special">></span> <a class="link" href="environment.html#idm46563252384400-bb"><span class="identifier">host_rank</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">static</span> <span class="identifier">optional</span><span class="special"><</span> <span class="keyword">int</span> <span class="special">></span> <a class="link" href="environment.html#idm46563252380256-bb"><span class="identifier">io_rank</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <a class="link" href="environment.html#idm46563252375072-bb"><span class="identifier">processor_name</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">static</span> <span class="identifier">threading</span><span class="special">::</span><span class="identifier">level</span> <a class="link" href="environment.html#idm46563252371888-bb"><span class="identifier">thread_level</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">bool</span> <a class="link" href="environment.html#idm46563252370320-bb"><span class="identifier">is_main_thread</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="idm45927878424416"></a><h2>Description</h2>
<p>The <code class="computeroutput">environment</code> class is used to initialize, finalize, and query the MPI environment. It will typically be used in the <code class="computeroutput">main()</code> function of a program, which will create a single instance of <code class="computeroutput">environment</code> initialized with the arguments passed to the program:</p>
<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[</span><span class="special">]</span><span class="special">)</span>
<span class="special">{</span>
<span class="identifier">mpi</span><span class="special">::</span><span class="identifier">environment</span> <span class="identifier">env</span><span class="special">(</span><span class="identifier">argc</span><span class="special">,</span> <span class="identifier">argv</span><span class="special">)</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>The instance of <code class="computeroutput">environment</code> will initialize MPI (by calling <code class="computeroutput">MPI_Init</code>) in its constructor and finalize MPI (by calling <code class="computeroutput">MPI_Finalize</code> for normal termination or <code class="computeroutput">MPI_Abort</code> for an uncaught exception) in its destructor.</p>
<p>The use of <code class="computeroutput">environment</code> is not mandatory. Users may choose to invoke <code class="computeroutput">MPI_Init</code> and <code class="computeroutput">MPI_Finalize</code> manually. In this case, no <code class="computeroutput">environment</code> object is needed. If one is created, however, it will do nothing on either construction or destruction. </p>
<div class="refsect2">
<a name="idm45927878400096"></a><h3>
<a name="boost.mpi.environmentconstruct-copy-destruct"></a><code class="computeroutput">environment</code>
public
construct/copy/destruct</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
<pre class="literallayout"><span class="keyword">explicit</span> <a name="idm46563252434912-bb"></a><span class="identifier">environment</span><span class="special">(</span><span class="keyword">bool</span> abort_on_exception <span class="special">=</span> <span class="keyword">true</span><span class="special">)</span><span class="special">;</span></pre>
<p>Initialize the MPI environment.</p>
<p>If the MPI environment has not already been initialized, initializes MPI with a call to <code class="computeroutput">MPI_Init</code>. Since this constructor does not take command-line arguments (<code class="computeroutput">argc</code> and <code class="computeroutput">argv</code>), it is only available when the underlying MPI implementation supports calling <code class="computeroutput">MPI_Init</code> with <code class="computeroutput">NULL</code> arguments, indicated by the macro <code class="computeroutput">BOOST_MPI_HAS_NOARG_INITIALIZATION</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Parameters:</span></p></td>
<td><div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term"><code class="computeroutput">abort_on_exception</code></span></p></td>
<td><p>When true, this object will abort the program if it is destructed due to an uncaught exception. </p></td>
</tr></tbody>
</table></div></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">explicit</span> <a name="idm46563252428960-bb"></a><span class="identifier">environment</span><span class="special">(</span><span class="identifier">threading</span><span class="special">::</span><span class="identifier">level</span> mt_level<span class="special">,</span>
<span class="keyword">bool</span> abort_on_exception <span class="special">=</span> <span class="keyword">true</span><span class="special">)</span><span class="special">;</span></pre>
<p>Initialize the MPI environment.</p>
<p>If the MPI environment has not already been initialized, initializes MPI with a call to <code class="computeroutput">MPI_Init_thread</code>. Since this constructor does not take command-line arguments (<code class="computeroutput">argc</code> and <code class="computeroutput">argv</code>), it is only available when the underlying MPI implementation supports calling <code class="computeroutput">MPI_Init</code> with <code class="computeroutput">NULL</code> arguments, indicated by the macro <code class="computeroutput">BOOST_MPI_HAS_NOARG_INITIALIZATION</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Parameters:</span></p></td>
<td><div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term"><code class="computeroutput">abort_on_exception</code></span></p></td>
<td><p>When true, this object will abort the program if it is destructed due to an uncaught exception. </p></td>
</tr>
<tr>
<td><p><span class="term"><code class="computeroutput">mt_level</code></span></p></td>
<td><p>the required level of threading support.</p></td>
</tr>
</tbody>
</table></div></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><a name="idm46563252421872-bb"></a><span class="identifier">environment</span><span class="special">(</span><span class="keyword">int</span> <span class="special">&</span> argc<span class="special">,</span> <span class="keyword">char</span> <span class="special">*</span><span class="special">*</span><span class="special">&</span> argv<span class="special">,</span> <span class="keyword">bool</span> abort_on_exception <span class="special">=</span> <span class="keyword">true</span><span class="special">)</span><span class="special">;</span></pre>
<p>Initialize the MPI environment.</p>
<p>If the MPI environment has not already been initialized, initializes MPI with a call to <code class="computeroutput">MPI_Init</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Parameters:</span></p></td>
<td><div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term"><code class="computeroutput">abort_on_exception</code></span></p></td>
<td><p>When true, this object will abort the program if it is destructed due to an uncaught exception. </p></td>
</tr>
<tr>
<td><p><span class="term"><code class="computeroutput">argc</code></span></p></td>
<td><p>The number of arguments provided in <code class="computeroutput">argv</code>, as passed into the program's <code class="computeroutput">main</code> function.</p></td>
</tr>
<tr>
<td><p><span class="term"><code class="computeroutput">argv</code></span></p></td>
<td><p>The array of argument strings passed to the program via <code class="computeroutput">main</code>.</p></td>
</tr>
</tbody>
</table></div></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><a name="idm46563252414944-bb"></a><span class="identifier">environment</span><span class="special">(</span><span class="keyword">int</span> <span class="special">&</span> argc<span class="special">,</span> <span class="keyword">char</span> <span class="special">*</span><span class="special">*</span><span class="special">&</span> argv<span class="special">,</span> <span class="identifier">threading</span><span class="special">::</span><span class="identifier">level</span> mt_level<span class="special">,</span>
<span class="keyword">bool</span> abort_on_exception <span class="special">=</span> <span class="keyword">true</span><span class="special">)</span><span class="special">;</span></pre>
<p>Initialize the MPI environment.</p>
<p>If the MPI environment has not already been initialized, initializes MPI with a call to <code class="computeroutput">MPI_Init_thread</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Parameters:</span></p></td>
<td><div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term"><code class="computeroutput">abort_on_exception</code></span></p></td>
<td><p>When true, this object will abort the program if it is destructed due to an uncaught exception. </p></td>
</tr>
<tr>
<td><p><span class="term"><code class="computeroutput">argc</code></span></p></td>
<td><p>The number of arguments provided in <code class="computeroutput">argv</code>, as passed into the program's <code class="computeroutput">main</code> function.</p></td>
</tr>
<tr>
<td><p><span class="term"><code class="computeroutput">argv</code></span></p></td>
<td><p>The array of argument strings passed to the program via <code class="computeroutput">main</code>.</p></td>
</tr>
<tr>
<td><p><span class="term"><code class="computeroutput">mt_level</code></span></p></td>
<td><p>the required level of threading support</p></td>
</tr>
</tbody>
</table></div></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><a name="idm46563252406896-bb"></a><span class="special">~</span><span class="identifier">environment</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Shuts down the MPI environment.</p>
<p>If this <code class="computeroutput">environment</code> object was used to initialize the MPI environment, and the MPI environment has not already been shut down (finalized), this destructor will shut down the MPI environment. Under normal circumstances, this only involves invoking <code class="computeroutput">MPI_Finalize</code>. However, if destruction is the result of an uncaught exception and the <code class="computeroutput">abort_on_exception</code> parameter of the constructor had the value <code class="computeroutput">true</code>, this destructor will invoke <code class="computeroutput">MPI_Abort</code> with <code class="computeroutput">MPI_COMM_WORLD</code> to abort the entire MPI program with a result code of -1. </p>
</li>
</ol></div>
</div>
<div class="refsect2">
<a name="idm45927878311760"></a><h3>
<a name="idm46563252402832-bb"></a><code class="computeroutput">environment</code> public static functions</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="keyword">void</span> <a name="idm46563252402272-bb"></a><span class="identifier">abort</span><span class="special">(</span><span class="keyword">int</span> errcode<span class="special">)</span><span class="special">;</span></pre>
<p>Abort all MPI processes.</p>
<p>Aborts all MPI processes and returns to the environment. The precise behavior will be defined by the underlying MPI implementation. This is equivalent to a call to <code class="computeroutput">MPI_Abort</code> with <code class="computeroutput">MPI_COMM_WORLD</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term">Parameters:</span></p></td>
<td><div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term"><code class="computeroutput">errcode</code></span></p></td>
<td><p>The error code to return to the environment. </p></td>
</tr></tbody>
</table></div></td>
</tr>
<tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p>Will not return. </p></td>
</tr>
</tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="keyword">bool</span> <a name="idm46563252397552-bb"></a><span class="identifier">initialized</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Determine if the MPI environment has already been initialized.</p>
<p>This routine is equivalent to a call to <code class="computeroutput">MPI_Initialized</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p><code class="computeroutput">true</code> if the MPI environment has been initialized. </p></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="keyword">bool</span> <a name="idm46563252394176-bb"></a><span class="identifier">finalized</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Determine if the MPI environment has already been finalized.</p>
<p>The routine is equivalent to a call to <code class="computeroutput">MPI_Finalized</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p><code class="computeroutput">true</code> if the MPI environment has been finalized. </p></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="keyword">int</span> <a name="idm46563252390816-bb"></a><span class="identifier">max_tag</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Retrieves the maximum tag value.</p>
<p>Returns the maximum value that may be used for the <code class="computeroutput">tag</code> parameter of send/receive operations. This value will be somewhat smaller than the value of <code class="computeroutput">MPI_TAG_UB</code>, because the Boost.MPI implementation reserves some tags for collective operations.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p>the maximum tag value. </p></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="keyword">int</span> <a name="idm46563252387200-bb"></a><span class="identifier">collectives_tag</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>The tag value used for collective operations.</p>
<p>Returns the reserved tag value used by the Boost.MPI implementation for collective operations. Although users are not permitted to use this tag to send or receive messages, it may be useful when monitoring communication patterns.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p>the tag value used for collective operations. </p></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="identifier">optional</span><span class="special"><</span> <span class="keyword">int</span> <span class="special">></span> <a name="idm46563252384400-bb"></a><span class="identifier">host_rank</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Retrieves the rank of the host process, if one exists.</p>
<p>If there is a host process, this routine returns the rank of that process. Otherwise, it returns an empty <code class="computeroutput">optional<int></code>. MPI does not define the meaning of a "host" process: consult the documentation for the MPI implementation. This routine examines the <code class="computeroutput">MPI_HOST</code> attribute of <code class="computeroutput">MPI_COMM_WORLD</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p>The rank of the host process, if one exists. </p></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="identifier">optional</span><span class="special"><</span> <span class="keyword">int</span> <span class="special">></span> <a name="idm46563252380256-bb"></a><span class="identifier">io_rank</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Retrieves the rank of a process that can perform input/output.</p>
<p>This routine returns the rank of a process that can perform input/output via the standard C and C++ I/O facilities. If every process can perform I/O using the standard facilities, this routine will return <code class="computeroutput">any_source</code>; if no process can perform I/O, this routine will return no value (an empty <code class="computeroutput">optional</code>). This routine examines the <code class="computeroutput">MPI_IO</code> attribute of <code class="computeroutput">MPI_COMM_WORLD</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p>the rank of the process that can perform I/O, <code class="computeroutput">any_source</code> if every process can perform I/O, or no value if no process can perform I/O. </p></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <a name="idm46563252375072-bb"></a><span class="identifier">processor_name</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Retrieve the name of this processor.</p>
<p>This routine returns the name of this processor. The actual form of the name is unspecified, but may be documented by the underlying MPI implementation. This routine is implemented as a call to <code class="computeroutput">MPI_Get_processor_name</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p>the name of this processor. </p></td>
</tr></tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="identifier">threading</span><span class="special">::</span><span class="identifier">level</span> <a name="idm46563252371888-bb"></a><span class="identifier">thread_level</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Query the current level of thread support. </p>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">static</span> <span class="keyword">bool</span> <a name="idm46563252370320-bb"></a><span class="identifier">is_main_thread</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Are we in the main thread? </p>
</li>
</ol></div>
</div>
</div>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor,
Matthias Troyer, Trustees of Indiana University<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">
http://www.boost.org/LICENSE_1_0.txt </a>)
</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="threading/operator_idm46563252358416.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../mpi/reference.html#header.boost.mpi.environment_hpp"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="exception.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>
|
