ceph/src/boost/libs/pool/doc/html/boost_pool/pool/introduction.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>Introduction</title>
   5 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
   6 <meta name="generator" content="DocBook XSL Stylesheets V1.76.1">
   7 <link rel="home" href="../../index.html" title="Boost.Pool">
   8 <link rel="up" href="../pool.html" title="Introduction and Overview">
   9 <link rel="prev" href="conventions.html" title="Documentation Naming and Formatting Conventions">
  10 <link rel="next" href="usage.html" title="How do I use Pool?">
  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="conventions.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pool.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="usage.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="boost_pool.pool.introduction"></a><a class="link" href="introduction.html" title="Introduction">Introduction</a>
  28 </h3></div></div></div>
  29 <h6>
  30 <a name="boost_pool.pool.introduction.h0"></a>
  31         <span><a name="boost_pool.pool.introduction.what_is_pool_"></a></span><a class="link" href="introduction.html#boost_pool.pool.introduction.what_is_pool_">What
  32         is Pool?</a>
  33       </h6>
  34 <p>
  35         Pool allocation is a memory allocation scheme that is very fast, but limited
  36         in its usage. For more information on pool allocation (also called <span class="emphasis"><em>simple
  37         segregated storage</em></span>, see <a class="link" href="pooling.html#boost_pool.pool.pooling.concepts" title="Basic ideas behind pooling">concepts</a>
  38         concepts and <a class="link" href="pooling.html#boost_pool.pool.pooling.simple" title="Simple Segregated Storage">Simple Segregated
  39         Storage</a>).
  40       </p>
  41 <h6>
  42 <a name="boost_pool.pool.introduction.h1"></a>
  43         <span><a name="boost_pool.pool.introduction.why_should_i_use_pool_"></a></span><a class="link" href="introduction.html#boost_pool.pool.introduction.why_should_i_use_pool_">Why
  44         should I use Pool?</a>
  45       </h6>
  46 <p>
  47         Using Pools gives you more control over how memory is used in your program.
  48         For example, you could have a situation where you want to allocate a bunch
  49         of small objects at one point, and then reach a point in your program where
  50         none of them are needed any more. Using pool interfaces, you can choose to
  51         run their destructors or just drop them off into oblivion; the pool interface
  52         will guarantee that there are no system memory leaks.
  53       </p>
  54 <h6>
  55 <a name="boost_pool.pool.introduction.h2"></a>
  56         <span><a name="boost_pool.pool.introduction.when_should_i_use_pool_"></a></span><a class="link" href="introduction.html#boost_pool.pool.introduction.when_should_i_use_pool_">When should
  57         I use Pool?</a>
  58       </h6>
  59 <p>
  60         Pools are generally used when there is a lot of allocation and deallocation
  61         of small objects. Another common usage is the situation above, where many
  62         objects may be dropped out of memory.
  63       </p>
  64 <p>
  65         In general, use Pools when you need a more efficient way to do unusual memory
  66         control.
  67       </p>
  68 <h6>
  69 <a name="boost_pool.pool.introduction.h3"></a>
  70         <span><a name="boost_pool.pool.introduction.which_pool_allocator_should_i_use_"></a></span><a class="link" href="introduction.html#boost_pool.pool.introduction.which_pool_allocator_should_i_use_">Which
  71         pool allocator should I use?</a>
  72       </h6>
  73 <p>
  74         <code class="computeroutput"><span class="identifier">pool_allocator</span></code> is a more
  75         general-purpose solution, geared towards efficiently servicing requests for
  76         any number of contiguous chunks.
  77       </p>
  78 <p>
  79         <code class="computeroutput"><span class="identifier">fast_pool_allocator</span></code> is also
  80         a general-purpose solution but is geared towards efficiently servicing requests
  81         for one chunk at a time; it will work for contiguous chunks, but not as well
  82         as pool_allocator.
  83       </p>
  84 <p>
  85         If you are seriously concerned about performance, use <code class="computeroutput"><span class="identifier">fast_pool_allocator</span></code>
  86         when dealing with containers such as <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">list</span></code>,
  87         and use <code class="computeroutput"><span class="identifier">pool_allocator</span></code> when
  88         dealing with containers such as <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span></code>.
  89       </p>
  90 </div>
  91 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
  92 <td align="left"></td>
  93 <td align="right"><div class="copyright-footer">Copyright &#169; 2000-2006 Stephen Cleary<br>Copyright &#169; 2011 Paul A. Bristow<p>
  94         Distributed under the Boost Software License, Version 1.0. (See accompanying
  95         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>)
  96       </p>
  97 </div></td>
  98 </tr></table>
  99 <hr>
 100 <div class="spirit-nav">
 101 <a accesskey="p" href="conventions.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pool.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="usage.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
 102 </div>
 103 </body>
 104 </html>