Codebase list cppad / upstream/2015.00.00.7 doc / ta_get_memory.xml
upstream/2015.00.00.7

Tree @upstream/2015.00.00.7 (Download .tar.gz)

ta_get_memory.xml @upstream/2015.00.00.7 — raw · history · blame 

  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
<?xml version='1.0'?>
<html xmlns='http://www.w3.org/1999/xhtml'
      xmlns:math='http://www.w3.org/1998/Math/MathML'
>
<head>
<title>Get At Least A Specified Amount of Memory</title>
<meta http-equiv='Content-Type' content='text/html' charset='utf-8'/>
<meta name="description" id="description" content="Get At Least A Specified Amount of Memory"/>
<meta name="keywords" id="keywords" content=" get at least a specified amount of memory thread_num thread_alloc allocate syntax purpose min_bytes cap_bytes v_ptr allocation speed alignment example "/>
<style type='text/css'>
body { color : black }
body { background-color : white }
A:link { color : blue }
A:visited { color : purple }
A:active { color : purple }
</style>
<script type='text/javascript' language='JavaScript' src='_ta_get_memory_xml.js'>
</script>
</head>
<body>
<table><tr>
<td>
<a href="http://www.coin-or.org/CppAD/" target="_top"><img border="0" src="_image.gif"/></a>
</td>
<td><a href="ta_thread_num.xml" target="_top">Prev</a>
</td><td><a href="ta_return_memory.xml" target="_top">Next</a>
</td><td>
<select onchange='choose_across0(this)'>
<option>Index-&gt;</option>
<option>contents</option>
<option>reference</option>
<option>index</option>
<option>search</option>
<option>external</option>
</select>
</td>
<td>
<select onchange='choose_up0(this)'>
<option>Up-&gt;</option>
<option>CppAD</option>
<option>library</option>
<option>thread_alloc</option>
<option>ta_get_memory</option>
</select>
</td>
<td>
<select onchange='choose_down3(this)'>
<option>CppAD-&gt;</option>
<option>Install</option>
<option>Introduction</option>
<option>AD</option>
<option>ADFun</option>
<option>preprocessor</option>
<option>multi_thread</option>
<option>library</option>
<option>ipopt_solve</option>
<option>Example</option>
<option>speed</option>
<option>Appendix</option>
</select>
</td>
<td>
<select onchange='choose_down2(this)'>
<option>library-&gt;</option>
<option>ErrorHandler</option>
<option>NearEqual</option>
<option>speed_test</option>
<option>SpeedTest</option>
<option>time_test</option>
<option>NumericType</option>
<option>CheckNumericType</option>
<option>SimpleVector</option>
<option>CheckSimpleVector</option>
<option>nan</option>
<option>pow_int</option>
<option>Poly</option>
<option>LuDetAndSolve</option>
<option>RombergOne</option>
<option>RombergMul</option>
<option>Runge45</option>
<option>Rosen34</option>
<option>OdeErrControl</option>
<option>OdeGear</option>
<option>OdeGearControl</option>
<option>CppAD_vector</option>
<option>thread_alloc</option>
<option>index_sort</option>
<option>BenderQuad</option>
<option>opt_val_hes</option>
<option>LuRatio</option>
</select>
</td>
<td>
<select onchange='choose_down1(this)'>
<option>thread_alloc-&gt;</option>
<option>thread_alloc.cpp</option>
<option>ta_parallel_setup</option>
<option>ta_num_threads</option>
<option>ta_in_parallel</option>
<option>ta_thread_num</option>
<option>ta_get_memory</option>
<option>ta_return_memory</option>
<option>ta_free_available</option>
<option>ta_hold_memory</option>
<option>ta_inuse</option>
<option>ta_available</option>
<option>ta_create_array</option>
<option>ta_delete_array</option>
<option>ta_free_all</option>
</select>
</td>
<td>ta_get_memory</td>
<td>
<select onchange='choose_current0(this)'>
<option>Headings-&gt;</option>
<option>Syntax</option>
<option>Purpose</option>
<option>min_bytes</option>
<option>cap_bytes</option>
<option>v_ptr</option>
<option>Allocation Speed</option>
<option>Alignment</option>
<option>Example</option>
</select>
</td>
</tr></table><br/>



<center><b><big><big>Get At Least A Specified Amount of Memory</big></big></b></center>
<br/>
<b><big><a name="Syntax" id="Syntax">Syntax</a></big></b>

<br/>

<code><i><font color="black"><span style='white-space: nowrap'>v_ptr</span></font></i><font color="blue"><span style='white-space: nowrap'>&#xA0;=&#xA0;thread_alloc::get_memory(</span></font><i><font color="black"><span style='white-space: nowrap'>min_bytes</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>cap_bytes</span></font></i><font color="blue"><span style='white-space: nowrap'>)</span></font></code>


<br/>
<br/>
<b><big><a name="Purpose" id="Purpose">Purpose</a></big></b>
<br/>
Use <a href="thread_alloc.xml" target="_top"><span style='white-space: nowrap'>thread_alloc</span></a>
 to obtain a minimum number of bytes of memory
(for use by the <a href="ta_thread_num.xml" target="_top"><span style='white-space: nowrap'>current&#xA0;thread</span></a>
).

<br/>
<br/>
<b><big><a name="min_bytes" id="min_bytes">min_bytes</a></big></b>
<br/>
This argument has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;size_t&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>min_bytes</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
It specifies the minimum number of bytes to allocate.
This value must be less than
<code><font color='blue'><pre style='display:inline'> 
	std::numeric_limits&lt;size_t&gt;::max() / 2
</pre></font></code>


<br/>
<br/>
<b><big><a name="cap_bytes" id="cap_bytes">cap_bytes</a></big></b>
<br/>
This argument has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;size_t&amp;&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>cap_bytes</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
It's input value does not matter.
Upon return, it is the actual number of bytes (capacity) 
that have been allocated for use,

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>min_bytes</span></font></i><font color="blue"><span style='white-space: nowrap'>&#xA0;&lt;=&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>cap_bytes</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
<br/>
<b><big><a name="v_ptr" id="v_ptr">v_ptr</a></big></b>
<br/>
The return value 
<code><i><font color="black"><span style='white-space: nowrap'>v_ptr</span></font></i></code>
 has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;void*&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>v_ptr</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
It is the location where the 
<code><i><font color="black"><span style='white-space: nowrap'>cap_bytes</span></font></i></code>
 of memory 
that have been allocated for use begins.

<br/>
<br/>
<b><big><a name="Allocation Speed" id="Allocation Speed">Allocation Speed</a></big></b>
<br/>
This allocation should be faster if the following conditions hold:
<ol type="1"><li>
The memory allocated by a previous call to <code><font color="blue">get_memory</font></code> 
is currently available for use.
</li><li>

The current 
<code><i><font color="black"><span style='white-space: nowrap'>min_bytes</span></font></i></code>
 is between 
the previous 
<code><i><font color="black"><span style='white-space: nowrap'>min_bytes</span></font></i></code>
 and previous 
<code><i><font color="black"><span style='white-space: nowrap'>cap_bytes</span></font></i></code>
.
</li></ol>


<br/>
<br/>
<b><big><a name="Alignment" id="Alignment">Alignment</a></big></b>
<br/>
We call a memory allocation aligned if the address is a multiple
of the number of bytes in a <code><font color="blue">size_t</font></code> value.
If the system <code><font color="blue">new</font></code> allocator is aligned, then 
<code><i><font color="black"><span style='white-space: nowrap'>v_ptr</span></font></i></code>

pointer is also aligned.

<br/>
<br/>
<b><big><a name="Example" id="Example">Example</a></big></b>

<br/>
<a href="thread_alloc.cpp.xml" target="_top"><span style='white-space: nowrap'>thread_alloc.cpp</span></a>



<hr/>Input File: cppad/thread_alloc.hpp

</body>
</html>