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| 9 | |
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| 10 | <title>Object Pool Implementation</title> |
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| 11 | </head> |
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| 12 | |
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| 13 | <body> |
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| 14 | <img src="../../../../boost.png" width="276" height="86" alt="C++ Boost"> |
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| 15 | |
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| 16 | <h1 align="center">Object Pool Implementation</h1> |
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| 17 | |
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| 18 | <h2>Dependencies</h2> |
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| 19 | |
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| 20 | <p>Includes the Boost header <span class="code">"pool.hpp"</span> (see |
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| 21 | <a href="pool.html">pool.html</a>).</p> |
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| 22 | |
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| 23 | <h2>Extensions to Public Interface</h2> |
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| 24 | |
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| 25 | <p>Whenever an object of type <span class="code">ObjectPool</span> needs |
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| 26 | memory from the system, it will request it from its <span class= |
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| 27 | "code">UserAllocator</span> template parameter. The amount requested is |
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| 28 | determined using a doubling algorithm; that is, each time more system |
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| 29 | memory is allocated, the amount of system memory requested is doubled. |
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| 30 | Users may control the doubling algorithm by using the following |
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| 31 | extensions.</p> |
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| 32 | |
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| 33 | <h3>Additional constructor parameter</h3> |
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| 34 | |
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| 35 | <p>Users may pass an additional constructor parameter to <span class= |
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| 36 | "code">ObjectPool</span>. This parameter is of type <span class= |
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| 37 | "code">size_type</span>, and is the number of chunks to request from the |
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| 38 | system the first time that object needs to allocate system memory. The |
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| 39 | default is 32. This parameter may not be 0.</p> |
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| 40 | |
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| 41 | <h3><span class="code">next_size</span> accessor functions</h3> |
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| 42 | |
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| 43 | <p>The pair of functions <span class="code">size_type get_next_size() |
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| 44 | const;</span> and <span class="code">void set_next_size(size_type);</span> |
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| 45 | allow users to explicitly read and write the <span class= |
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| 46 | "code">next_size</span> value. This value is the number of chunks to |
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| 47 | request from the system the next time that object needs to allocate system |
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| 48 | memory. This value should never be set to 0.</p> |
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| 49 | |
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| 50 | <h2>Protected Interface</h2> |
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| 51 | |
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| 52 | <h3>Synopsis</h3> |
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| 53 | <pre class="code"> |
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| 54 | template <typename ElementType, typename UserAllocator = default_user_allocator_new_delete> |
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| 55 | class object_pool: protected pool<UserAllocator> |
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| 56 | { |
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| 57 | ... // public interface |
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| 58 | }; |
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| 59 | </pre> |
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| 60 | |
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| 61 | <h3>Protected Derivation</h3>ObjectPool derives from a simple segregated |
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| 62 | storage via protected derivation; this exposes all the <a href= |
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| 63 | "pool.html">Pool implementation details</a> to all classes derived from |
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| 64 | ObjectPool as well. |
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| 65 | |
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| 66 | <h2><a href="../interfaces/object_pool.html">Interface Description</a></h2> |
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| 67 | <hr> |
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| 68 | |
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| 69 | <p><a href="http://validator.w3.org/check?uri=referer"><img border="0" src= |
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| 71 | height="31" width="88"></a></p> |
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| 72 | |
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| 73 | <p>Revised |
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| 74 | <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %B, %Y" startspan -->05 |
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| 75 | December, 2006<!--webbot bot="Timestamp" endspan i-checksum="38516" --></p> |
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| 76 | |
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| 77 | <p><i>Copyright © 2000, 2001 Stephen Cleary (scleary AT jerviswebb DOT |
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| 78 | com)</i></p> |
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| 79 | |
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| 80 | <p><i>Distributed under the Boost Software License, Version 1.0. (See |
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| 81 | accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> |
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| 82 | or copy at <a href= |
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| 83 | "http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</a>)</i></p> |
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| 84 | </body> |
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| 85 | </html> |
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