l4/pkg/libstdc++-v3/contrib/libstdc++-v3-4.3.3/doc/html/ext/pb_ds/priority_queue_text_pop_mem_usage_test.html

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   7 <title>Priority Queue Text Pop Memory Use Test</title>
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  11 <div id="page">
  12 <h1>Priority Queue Text <tt>pop</tt> Memory Use Test</h1>
  13 <h2><a name="description" id="description">Description</a></h2>
  14 <p>This test inserts a number of values with keys from an
  15     arbitrary text ([ <a href="references.html#wickland96thirty">wickland96thirty</a> ]) into
  16     a container, then pops them until only one is left in the
  17     container. It measures the memory use as a function of the
  18     number of values pushed to the container.</p>
  19 <p>(The test was executed with <a href="../../../../testsuite/performance/ext/pb_ds/priority_queue_text_pop_mem_usage.cc"><tt>priority_queue_text_pop_mem_usage_test</tt></a>
  20     thirty_years_among_the_dead_preproc.txt 200 200 2100)</p>
  21 <h2><a name="purpose" id="purpose">Purpose</a></h2>
  22 <p>The test checks the effect of different underlying
  23     data structures (see <a href="pq_design.html#pq_imp">Design::Priority
  24     Queues::Implementations</a>).</p>
  25 <h2><a name="results" id="results">Results</a></h2>
  26 <p>Figures <a href="#NPG">NPG</a>, <a href="#NPM">NPM</a>, and
  27     <a href="#NPL">NPL</a> show the results for the native priority
  28     queues and <tt>pb_ds</tt> 's priority queues in <a href="pq_performance_tests.html#gcc"><u>g++</u></a>, <a href="pq_performance_tests.html#msvc"><u>msvc++</u></a>, and
  29     <a href="pq_performance_tests.html#local"><u>local</u></a>,
  30     respectively.</p>
  31 <div id="NPG_res_div">
  32 <div id="NPG_gcc">
  33 <div id="NPG_priority_queue_text_pop_mem_usage_test">
  34 <div id="NPG_pq">
  35 <div id="NPG_Native_and__tt_pb_ds_455tt__priority_queue__tt_pop_455tt__memory-use_test"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NPG" id="NPG"><img src="priority_queue_text_pop_mem_usage_test_gcc.png" alt="no image" /></a></h6>NPG: Native and <tt>pb ds</tt> priority queue <tt>pop</tt> memory-use test - <a href="pq_performance_tests.html#gcc">g++</a><p>In the above figure, the names in the legends have the following meaning:</p>
  36 <ol>
  37 <li>
  38 n_pq_vector-
  39 <tt>std::priority_queue</tt> adapting <tt>std::vector</tt></li>
  40 <li>
  41 n_pq_deque-
  42 <tt>std::priority_queue</tt> adapting <tt>std::deque</tt></li>
  43 <li>
  44 binary_heap-
  45 <a href="priority_queue.html"><tt>priority_queue</tt></a>
  46  with <tt>Tag</tt> = <a href="binary_heap_tag.html"><tt>binary_heap_tag</tt></a>
  47 </li>
  48 <li>
  49 thin_heap-
  50 <a href="priority_queue.html"><tt>priority_queue</tt></a>
  51  with <tt>Tag</tt> = <a href="thin_heap_tag.html"><tt>thin_heap_tag</tt></a>
  52 </li>
  53 <li>
  54 binomial_heap-
  55 <a href="priority_queue.html"><tt>priority_queue</tt></a>
  56  with <tt>Tag</tt> = <a href="binomial_heap_tag.html"><tt>binomial_heap_tag</tt></a>
  57 </li>
  58 <li>
  59 rc_binomial_heap-
  60 <a href="priority_queue.html"><tt>priority_queue</tt></a>
  61  with <tt>Tag</tt> = <a href="rc_binomial_heap_tag.html"><tt>rc_binomial_heap_tag</tt></a>
  62 </li>
  63 <li>
  64 pairing_heap-
  65 <a href="priority_queue.html"><tt>priority_queue</tt></a>
  66  with <tt>Tag</tt> = <a href="pairing_heap_tag.html"><tt>pairing_heap_tag</tt></a>
  67 </li>
  68 </ol>
  69 </div><div style="width: 100%; height: 20px"></div></div>
  70 </div>
  71 </div>
  72 </div>
  73 </div>
  74 <div id="NPM_res_div">
  75 <div id="NPM_msvc">
  76 <div id="NPM_priority_queue_text_pop_mem_usage_test">
  77 <div id="NPM_pq">
  78 <div id="NPM_Native_and__tt_pb_ds_455tt__priority_queue__tt_pop_455tt__memory-use_test"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NPM" id="NPM"><img src="priority_queue_text_pop_mem_usage_test_msvc.png" alt="no image" /></a></h6>NPM: Native and <tt>pb ds</tt> priority queue <tt>pop</tt> memory-use test - <a href="pq_performance_tests.html#msvc">msvc++</a><p>In the above figure, the names in the legends have the following meaning:</p>
  79 <ol>
  80 <li>
  81 n_pq_vector-
  82 <tt>std::priority_queue</tt> adapting <tt>std::vector</tt></li>
  83 <li>
  84 n_pq_deque-
  85 <tt>std::priority_queue</tt> adapting <tt>std::deque</tt></li>
  86 <li>
  87 binary_heap-
  88 <a href="priority_queue.html"><tt>priority_queue</tt></a>
  89  with <tt>Tag</tt> = <a href="binary_heap_tag.html"><tt>binary_heap_tag</tt></a>
  90 </li>
  91 <li>
  92 thin_heap-
  93 <a href="priority_queue.html"><tt>priority_queue</tt></a>
  94  with <tt>Tag</tt> = <a href="thin_heap_tag.html"><tt>thin_heap_tag</tt></a>
  95 </li>
  96 <li>
  97 binomial_heap-
  98 <a href="priority_queue.html"><tt>priority_queue</tt></a>
  99  with <tt>Tag</tt> = <a href="binomial_heap_tag.html"><tt>binomial_heap_tag</tt></a>
 100 </li>
 101 <li>
 102 rc_binomial_heap-
 103 <a href="priority_queue.html"><tt>priority_queue</tt></a>
 104  with <tt>Tag</tt> = <a href="rc_binomial_heap_tag.html"><tt>rc_binomial_heap_tag</tt></a>
 105 </li>
 106 <li>
 107 pairing_heap-
 108 <a href="priority_queue.html"><tt>priority_queue</tt></a>
 109  with <tt>Tag</tt> = <a href="pairing_heap_tag.html"><tt>pairing_heap_tag</tt></a>
 110 </li>
 111 </ol>
 112 </div><div style="width: 100%; height: 20px"></div></div>
 113 </div>
 114 </div>
 115 </div>
 116 </div>
 117 <div id="NPL_res_div">
 118 <div id="NPL_local">
 119 <div id="NPL_priority_queue_text_pop_mem_usage_test">
 120 <div id="NPL_pq">
 121 <div id="NPL_Native_and__tt_pb_ds_455tt__priority_queue__tt_pop_455tt__memory-use_test"><div style = "border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NPL" id= "NPL"><img src="priority_queue_text_pop_mem_usage_test_local.png" alt="no image" /></a></h6>NPL: Native and <tt>pb ds</tt> priority queue <tt>pop</tt> memory-use test - <a href = "pq_performance_tests.html#local">local</a></div><div style = "width: 100%; height: 20px"></div></div>
 122 </div>
 123 </div>
 124 </div>
 125 </div>
 126 <h2><a name="observations" id="observations">Observations</a></h2>
 127 <p>The priority queue implementations (excluding the STL's) use
 128     memory proportionally to the number of values they hold:
 129     node-based implementations (<i>e.g.</i>, a pairing heap) do so
 130     naturally; <tt>pb_ds</tt>'s binary heap de-allocates memory when
 131     a certain lower threshold is exceeded.</p>
 132 <p>Note from <a href="priority_queue_text_push_pop_timing_test.html">Priority Queue
 133     Text <tt>push</tt> and <tt>pop</tt> Timing Test</a> and
 134     <a href="priority_queue_random_int_push_pop_timing_test.html">Priority
 135     Queue Random Integer <tt>push</tt> and <tt>pop</tt> Timing
 136     Test</a> that this does not impede performance compared to the
 137     STL's priority queues.</p>
 138 <p>(See <a href="hash_random_int_erase_mem_usage_test.html">Hash-Based Erase
 139     Memory Use Test</a> for a similar phenomenon regarding priority
 140     queues.)</p>
 141 </div>
 142 </body>
 143 </html>