ceph/src/boost/libs/fiber/doc/html/fiber/stack/pooled_fixedsize.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>Class pooled_fixedsize_stack</title>
   5 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
   6 <meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
   7 <link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Fiber">
   8 <link rel="up" href="../stack.html" title="Stack allocation">
   9 <link rel="prev" href="protected_fixedsize.html" title="Class protected_fixedsize_stack">
  10 <link rel="next" href="fixedsize.html" title="Class fixedsize_stack">
  11 </head>
  12 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
  13 <table cellpadding="2" width="100%"><tr>
  14 <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
  15 <td align="center"><a href="../../../../../../index.html">Home</a></td>
  16 <td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
  17 <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
  18 <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
  19 <td align="center"><a href="../../../../../../more/index.htm">More</a></td>
  20 </tr></table>
  21 <hr>
  22 <div class="spirit-nav">
  23 <a accesskey="p" href="protected_fixedsize.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><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="fixedsize.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
  24 </div>
  25 <div class="section">
  26 <div class="titlepage"><div><div><h3 class="title">
  27 <a name="fiber.stack.pooled_fixedsize"></a><a class="link" href="pooled_fixedsize.html" title="Class pooled_fixedsize_stack">Class <span class="emphasis"><em>pooled_fixedsize_stack</em></span></a>
  28 </h3></div></div></div>
  29 <p>
  30         <span class="bold"><strong>Boost.Fiber</strong></span> provides the class <a class="link" href="../../"> <code class="computeroutput">pooled_fixedsize_stack</code></a> which
  31         models the <a class="link" href="../stack.html#stack_allocator_concept"><span class="emphasis"><em>stack-allocator
  32         concept</em></span></a>. In contrast to <a class="link" href="../../"> <code class="computeroutput">protected_fixedsize_stack</code></a> it
  33         does not append a guard page at the end of each stack. The memory is managed
  34         internally by <a href="http://www.boost.org/doc/libs/release/libs/pool/doc/html/boost/pool.html" target="_top"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">pool</span><span class="special">&lt;&gt;</span></code></a>.
  35       </p>
  36 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fiber</span><span class="special">/</span><span class="identifier">pooled_fixedsize_stack</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
  37
  38 <span class="keyword">struct</span> <span class="identifier">pooled_fixedsize_stack</span> <span class="special">{</span>
  39     <span class="identifier">pooled_fixedsize_stack</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">stack_size</span> <span class="special">=</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">default_size</span><span class="special">(),</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">next_size</span> <span class="special">=</span> <span class="number">32</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size</span> <span class="special">=</span> <span class="number">0</span><span class="special">);</span>
  40
  41     <span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">();</span>
  42
  43     <span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span> <span class="special">&amp;);</span>
  44 <span class="special">}</span>
  45 </pre>
  46 <h5>
  47 <a name="fiber.stack.pooled_fixedsize.h0"></a>
  48         <span><a name="fiber.stack.pooled_fixedsize._code__phrase_role__identifier__pooled_fixedsize_stack__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__stack_size__phrase__phrase_role__special_____phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__next_size__phrase__phrase_role__special_____phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__max_size__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="pooled_fixedsize.html#fiber.stack.pooled_fixedsize._code__phrase_role__identifier__pooled_fixedsize_stack__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__stack_size__phrase__phrase_role__special_____phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__next_size__phrase__phrase_role__special_____phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__max_size__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="identifier">pooled_fixedsize_stack</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span>
  49         <span class="identifier">stack_size</span><span class="special">,</span>
  50         <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">next_size</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size</span><span class="special">)</span></code></a>
  51       </h5>
  52 <div class="variablelist">
  53 <p class="title"><b></b></p>
  54 <dl>
  55 <dt><span class="term">Preconditions:</span></dt>
  56 <dd><p>
  57               <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span>
  58               <span class="special">||</span> <span class="special">(</span>
  59               <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum_size</span><span class="special">()</span>
  60               <span class="special">&gt;=</span> <span class="identifier">stack_size</span><span class="special">)</span></code> and <code class="computeroutput"><span class="number">0</span>
  61               <span class="special">&lt;</span> <span class="identifier">next_size</span></code>.
  62             </p></dd>
  63 <dt><span class="term">Effects:</span></dt>
  64 <dd><p>
  65               Allocates memory of at least <code class="computeroutput"><span class="identifier">stack_size</span></code>
  66               bytes and stores a pointer to the stack and its actual size in <code class="computeroutput"><span class="identifier">sctx</span></code>. Depending on the architecture
  67               (the stack grows downwards/upwards) the stored address is the highest/lowest
  68               address of the stack. Argument <code class="computeroutput"><span class="identifier">next_size</span></code>
  69               determines the number of stacks to request from the system the first
  70               time that <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
  71               needs to allocate system memory. The third argument <code class="computeroutput"><span class="identifier">max_size</span></code>
  72               controls how much memory might be allocated for stacks &#8212; a value of zero
  73               means no upper limit.
  74             </p></dd>
  75 </dl>
  76 </div>
  77 <h5>
  78 <a name="fiber.stack.pooled_fixedsize.h1"></a>
  79         <span><a name="fiber.stack.pooled_fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="pooled_fixedsize.html#fiber.stack.pooled_fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">()</span></code></a>
  80       </h5>
  81 <div class="variablelist">
  82 <p class="title"><b></b></p>
  83 <dl>
  84 <dt><span class="term">Preconditions:</span></dt>
  85 <dd><p>
  86               <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span>
  87               <span class="special">||</span> <span class="special">(</span>
  88               <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum_size</span><span class="special">()</span>
  89               <span class="special">&gt;=</span> <span class="identifier">stack_size</span><span class="special">)</span></code>.
  90             </p></dd>
  91 <dt><span class="term">Effects:</span></dt>
  92 <dd><p>
  93               Allocates memory of at least <code class="computeroutput"><span class="identifier">stack_size</span></code>
  94               bytes and stores a pointer to the stack and its actual size in <code class="computeroutput"><span class="identifier">sctx</span></code>. Depending on the architecture
  95               (the stack grows downwards/upwards) the stored address is the highest/lowest
  96               address of the stack.
  97             </p></dd>
  98 </dl>
  99 </div>
 100 <h5>
 101 <a name="fiber.stack.pooled_fixedsize.h2"></a>
 102         <span><a name="fiber.stack.pooled_fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="pooled_fixedsize.html#fiber.stack.pooled_fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span>
 103         <span class="special">&amp;</span> <span class="identifier">sctx</span><span class="special">)</span></code></a>
 104       </h5>
 105 <div class="variablelist">
 106 <p class="title"><b></b></p>
 107 <dl>
 108 <dt><span class="term">Preconditions:</span></dt>
 109 <dd><p>
 110               <code class="computeroutput"><span class="identifier">sctx</span><span class="special">.</span><span class="identifier">sp</span></code> is valid, <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span> <span class="special">||</span> <span class="special">(</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum_size</span><span class="special">()</span> <span class="special">&gt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span><span class="special">)</span></code>.
 111             </p></dd>
 112 <dt><span class="term">Effects:</span></dt>
 113 <dd><p>
 114               Deallocates the stack space.
 115             </p></dd>
 116 </dl>
 117 </div>
 118 </div>
 119 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 120 <td align="left"></td>
 121 <td align="right"><div class="copyright-footer">Copyright &#169; 2013 Oliver Kowalke<p>
 122         Distributed under the Boost Software License, Version 1.0. (See accompanying
 123         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>)
 124       </p>
 125 </div></td>
 126 </tr></table>
 127 <hr>
 128 <div class="spirit-nav">
 129 <a accesskey="p" href="protected_fixedsize.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><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="fixedsize.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
 130 </div>
 131 </body>
 132 </html>