florian/mesytec-mnode
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
mesytec-mnode/external/taskflow-3.8.0/docs/classtf_1_1RandomPartitioner.html

242 lines
16 KiB
HTML
Raw Normal View History

add taskflow-3.8.0
2025-01-04 01:25:05 +01:00
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>tf::RandomPartitioner class | Taskflow QuickStart</title>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Source+Sans+Pro:400,400i,600,600i%7CSource+Code+Pro:400,400i,600" />
<link rel="stylesheet" href="m-dark+documentation.compiled.css" />
<link rel="icon" href="favicon.ico" type="image/vnd.microsoft.icon" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="theme-color" content="#22272e" />
</head>
<body>
<header><nav id="navigation">
<div class="m-container">
<div class="m-row">
<span id="m-navbar-brand" class="m-col-t-8 m-col-m-none m-left-m">
<a href="https://taskflow.github.io"><img src="taskflow_logo.png" alt="" />Taskflow</a> <span class="m-breadcrumb">|</span> <a href="index.html" class="m-thin">QuickStart</a>
</span>
<div class="m-col-t-4 m-hide-m m-text-right m-nopadr">
<a href="#search" class="m-doc-search-icon" title="Search" onclick="return showSearch()"><svg style="height: 0.9rem;" viewBox="0 0 16 16">
<path id="m-doc-search-icon-path" d="m6 0c-3.31 0-6 2.69-6 6 0 3.31 2.69 6 6 6 1.49 0 2.85-0.541 3.89-1.44-0.0164 0.338 0.147 0.759 0.5 1.15l3.22 3.79c0.552 0.614 1.45 0.665 2 0.115 0.55-0.55 0.499-1.45-0.115-2l-3.79-3.22c-0.392-0.353-0.812-0.515-1.15-0.5 0.895-1.05 1.44-2.41 1.44-3.89 0-3.31-2.69-6-6-6zm0 1.56a4.44 4.44 0 0 1 4.44 4.44 4.44 4.44 0 0 1-4.44 4.44 4.44 4.44 0 0 1-4.44-4.44 4.44 4.44 0 0 1 4.44-4.44z"/>
</svg></a>
<a id="m-navbar-show" href="#navigation" title="Show navigation"></a>
<a id="m-navbar-hide" href="#" title="Hide navigation"></a>
</div>
<div id="m-navbar-collapse" class="m-col-t-12 m-show-m m-col-m-none m-right-m">
<div class="m-row">
<ol class="m-col-t-6 m-col-m-none">
<li><a href="pages.html">Handbook</a></li>
<li><a href="namespaces.html">Namespaces</a></li>
</ol>
<ol class="m-col-t-6 m-col-m-none" start="3">
<li><a href="annotated.html">Classes</a></li>
<li><a href="files.html">Files</a></li>
<li class="m-show-m"><a href="#search" class="m-doc-search-icon" title="Search" onclick="return showSearch()"><svg style="height: 0.9rem;" viewBox="0 0 16 16">
<use href="#m-doc-search-icon-path" />
</svg></a></li>
</ol>
</div>
</div>
</div>
</div>
</nav></header>
<main><article>
<div class="m-container m-container-inflatable">
<div class="m-row">
<div class="m-col-l-10 m-push-l-1">
<h1>
<div class="m-doc-include m-code m-inverted m-right-m m-text-right"><span class="cp">#include</span> <a class="cpf" href="partitioner_8hpp.html">&lt;taskflow/algorithm/partitioner.hpp&gt;</a></div>
<div class="m-doc-template">template&lt;typename C = <a href="structtf_1_1DefaultClosureWrapper.html" class="m-doc">DefaultClosureWrapper</a>&gt;</div>
<span class="m-breadcrumb"><a href="namespacetf.html">tf</a>::<wbr/></span>RandomPartitioner <span class="m-thin">class</span>
</h1>
<p>class to construct a random partitioner for scheduling parallel algorithms</p>
<table class="m-table m-fullwidth m-flat">
<thead>
<tr><th colspan="2">Template parameters</th></tr>
</thead>
<tbody>
<tr>
<td style="width: 1%">C</td>
<td>closure wrapper type (default <a href="structtf_1_1DefaultClosureWrapper.html" class="m-doc">tf::<wbr />DefaultClosureWrapper</a>)</td>
</tr>
</tbody>
</table>
<nav class="m-block m-default">
<h3>Contents</h3>
<ul>
<li>
Reference
<ul>
<li><a href="#base-classes">Base classes</a></li>
<li><a href="#pub-static-methods">Public static functions</a></li>
<li><a href="#typeless-methods">Constructors, destructors, conversion operators</a></li>
<li><a href="#pub-methods">Public functions</a></li>
</ul>
</li>
</ul>
</nav>
<p>Similar to <a href="classtf_1_1DynamicPartitioner.html" class="m-doc">tf::<wbr />DynamicPartitioner</a>, the partitioner splits iterations into many partitions but each with a random chunk size in the range, <code>c = [alpha * N * W, beta * N * W]</code>. By default, <code>alpha</code> is <code>0.01</code> and <code>beta</code> is <code>0.5</code>, respectively.</p><p>In addition to partition size, the application can specify a closure wrapper for a random partitioner. A closure wrapper allows the application to wrapper a partitioned task (i.e., closure) with a custom function object that performs additional tasks. For example:</p><pre class="m-code"><span class="n">std</span><span class="o">::</span><span class="n">atomic</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">count</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="n">tf</span><span class="o">::</span><span class="n">Taskflow</span><span class="w"> </span><span class="n">taskflow</span><span class="p">;</span>
<span class="n">taskflow</span><span class="p">.</span><span class="n">for_each_index</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="mi">100</span><span class="p">,</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span>
<span class="w"> </span><span class="p">[](){</span><span class="w"> </span>
<span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;%d</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">,</span><span class="w"> </span><span class="n">i</span><span class="p">);</span><span class="w"> </span>
<span class="w"> </span><span class="p">},</span>
<span class="w"> </span><span class="n">tf</span><span class="o">::</span><span class="n">RandomPartitioner</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="p">[](</span><span class="k">auto</span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">closure</span><span class="p">){</span>
<span class="w"> </span><span class="c1">// do something before invoking the partitioned task</span>
<span class="w"> </span><span class="c1">// ...</span>
<span class="w"> </span>
<span class="w"> </span><span class="c1">// invoke the partitioned task</span>
<span class="w"> </span><span class="n">closure</span><span class="p">();</span>
<span class="w"> </span><span class="c1">// do something else after invoking the partitioned task</span>
<span class="w"> </span><span class="c1">// ...</span>
<span class="w"> </span><span class="p">}</span>
<span class="p">);</span>
<span class="n">executor</span><span class="p">.</span><span class="n">run</span><span class="p">(</span><span class="n">taskflow</span><span class="p">).</span><span class="n">wait</span><span class="p">();</span></pre>
<section id="base-classes">
<h2><a href="#base-classes">Base classes</a></h2>
<dl class="m-doc">
<dt>
<div class="m-doc-template">template&lt;typename C = <a href="structtf_1_1DefaultClosureWrapper.html" class="m-doc">DefaultClosureWrapper</a>&gt;</div>
class <a href="classtf_1_1PartitionerBase.html" class="m-doc">PartitionerBase&lt;DefaultClosureWrapper&gt;</a>
</dt>
<dd>class to derive a partitioner for scheduling parallel algorithms</dd>
</dl>
</section>
<section id="pub-static-methods">
<h2><a href="#pub-static-methods">Public static functions</a></h2>
<dl class="m-doc">
<dt id="a5c64a1d794cece6ed226fb1c14632cbb">
<span class="m-doc-wrap-bumper">static auto <a href="#a5c64a1d794cece6ed226fb1c14632cbb" class="m-doc-self">type</a>(</span><span class="m-doc-wrap">) -&gt; <a href="namespacetf.html#a32d51425fa23cd0dc3518c16cf3bb6c0" class="m-doc">PartitionerType</a> <span class="m-label m-flat m-primary">constexpr</span></span>
</dt>
<dd>queries the partition type (dynamic)</dd>
</dl>
</section>
<section id="typeless-methods">
<h2><a href="#typeless-methods">Constructors, destructors, conversion operators</a></h2>
<dl class="m-doc">
<dt id="a5ab28a71b47ce0ddef1764469d67153d">
<span class="m-doc-wrap-bumper"><a href="#a5ab28a71b47ce0ddef1764469d67153d" class="m-doc-self">RandomPartitioner</a>(</span><span class="m-doc-wrap">) <span class="m-label m-flat m-info">defaulted</span></span>
</dt>
<dd>default constructor</dd>
<dt id="a72fa7e849ffb0c9b6547edc719cbda50">
<span class="m-doc-wrap-bumper"><a href="#a72fa7e849ffb0c9b6547edc719cbda50" class="m-doc-self">RandomPartitioner</a>(</span><span class="m-doc-wrap">size_t sz) <span class="m-label m-flat m-info">explicit</span> </span>
</dt>
<dd>construct a dynamic partitioner with the given chunk size</dd>
<dt id="a3158af2f133856f3620fad20decd8d40">
<span class="m-doc-wrap-bumper"><a href="#a3158af2f133856f3620fad20decd8d40" class="m-doc-self">RandomPartitioner</a>(</span><span class="m-doc-wrap">size_t sz,
C&amp;&amp; closure) <span class="m-label m-flat m-info">explicit</span> </span>
</dt>
<dd>construct a random partitioner with the given chunk size and the closure</dd>
<dt id="a586f4233b5ace06598282b007b75ee7f">
<span class="m-doc-wrap-bumper"><a href="#a586f4233b5ace06598282b007b75ee7f" class="m-doc-self">RandomPartitioner</a>(</span><span class="m-doc-wrap">float alpha,
float beta)</span>
</dt>
<dd>constructs a random partitioner with the given parameters</dd>
<dt id="a36fcc5816916f621f0fb2eb9338b3376">
<span class="m-doc-wrap-bumper"><a href="#a36fcc5816916f621f0fb2eb9338b3376" class="m-doc-self">RandomPartitioner</a>(</span><span class="m-doc-wrap">float alpha,
float beta,
C&amp;&amp; closure)</span>
</dt>
<dd>constructs a random partitioner with the given parameters and the closure</dd>
</dl>
</section>
<section id="pub-methods">
<h2><a href="#pub-methods">Public functions</a></h2>
<dl class="m-doc">
<dt id="a67eea3b4ca4a2920a320d717ff3153aa">
<span class="m-doc-wrap-bumper">auto <a href="#a67eea3b4ca4a2920a320d717ff3153aa" class="m-doc-self">alpha</a>(</span><span class="m-doc-wrap">) const -&gt; float</span>
</dt>
<dd>queries the <code>alpha</code> value</dd>
<dt id="a8f378443b152a7f0b7476a82982d12cb">
<span class="m-doc-wrap-bumper">auto <a href="#a8f378443b152a7f0b7476a82982d12cb" class="m-doc-self">beta</a>(</span><span class="m-doc-wrap">) const -&gt; float</span>
</dt>
<dd>queries the <code>beta</code> value</dd>
<dt>
<span class="m-doc-wrap-bumper">auto <a href="#a7b283c21ca72666c7a12f0e82b28fde1" class="m-doc">chunk_size_range</a>(</span><span class="m-doc-wrap">size_t N,
size_t W) const -&gt; <a href="http://en.cppreference.com/w/cpp/utility/pair.html" class="m-doc-external">std::<wbr />pair</a>&lt;size_t, size_t&gt;</span>
</dt>
<dd>queries the range of chunk size</dd>
</dl>
</section>
<section>
<h2>Function documentation</h2>
<section class="m-doc-details" id="a7b283c21ca72666c7a12f0e82b28fde1"><div>
<h3>
<div class="m-doc-template">
template&lt;typename C&gt;
</div>
<span class="m-doc-wrap-bumper"><a href="http://en.cppreference.com/w/cpp/utility/pair.html" class="m-doc-external">std::<wbr />pair</a>&lt;size_t, size_t&gt; tf::<wbr />RandomPartitioner&lt;C&gt;::<wbr /></span><span class="m-doc-wrap"><span class="m-doc-wrap-bumper"><a href="#a7b283c21ca72666c7a12f0e82b28fde1" class="m-doc-self">chunk_size_range</a>(</span><span class="m-doc-wrap">size_t N,
size_t W) const</span></span>
</h3>
<p>queries the range of chunk size</p>
<table class="m-table m-fullwidth m-flat">
<thead>
<tr><th colspan="2">Parameters</th></tr>
</thead>
<tbody>
<tr>
<td style="width: 1%">N</td>
<td>number of iterations</td>
</tr>
<tr>
<td>W</td>
<td>number of workers</td>
</tr>
</tbody>
</table>
</div></section>
</section>
</div>
</div>
</div>
</article></main>
<div class="m-doc-search" id="search">
<a href="#!" onclick="return hideSearch()"></a>
<div class="m-container">
<div class="m-row">
<div class="m-col-m-8 m-push-m-2">
<div class="m-doc-search-header m-text m-small">
<div><span class="m-label m-default">Tab</span> / <span class="m-label m-default">T</span> to search, <span class="m-label m-default">Esc</span> to close</div>
<div id="search-symbolcount">&hellip;</div>
</div>
<div class="m-doc-search-content">
<form>
<input type="search" name="q" id="search-input" placeholder="Loading &hellip;" disabled="disabled" autofocus="autofocus" autocomplete="off" spellcheck="false" />
</form>
<noscript class="m-text m-danger m-text-center">Unlike everything else in the docs, the search functionality <em>requires</em> JavaScript.</noscript>
<div id="search-help" class="m-text m-dim m-text-center">
<p class="m-noindent">Search for symbols, directories, files, pages or
modules. You can omit any prefix from the symbol or file path; adding a
<code>:</code> or <code>/</code> suffix lists all members of given symbol or
directory.</p>
<p class="m-noindent">Use <span class="m-label m-dim">&darr;</span>
/ <span class="m-label m-dim">&uarr;</span> to navigate through the list,
<span class="m-label m-dim">Enter</span> to go.
<span class="m-label m-dim">Tab</span> autocompletes common prefix, you can
copy a link to the result using <span class="m-label m-dim">⌘</span>
<span class="m-label m-dim">L</span> while <span class="m-label m-dim">⌘</span>
<span class="m-label m-dim">M</span> produces a Markdown link.</p>
</div>
<div id="search-notfound" class="m-text m-warning m-text-center">Sorry, nothing was found.</div>
<ul id="search-results"></ul>
</div>
</div>
</div>
</div>
</div>
<script src="search-v2.js"></script>
<script src="searchdata-v2.js" async="async"></script>
<footer><nav>
<div class="m-container">
<div class="m-row">
<div class="m-col-l-10 m-push-l-1">
<p>Taskflow handbook is part of the <a href="https://taskflow.github.io">Taskflow project</a>, copyright © <a href="https://tsung-wei-huang.github.io/">Dr. Tsung-Wei Huang</a>, 2018&ndash;2024.<br />Generated by <a href="https://doxygen.org/">Doxygen</a> 1.9.1 and <a href="https://mcss.mosra.cz/">m.css</a>.</p>
</div>
</div>
</div>
</nav></footer>
</body>
</html>
Reference in a new issue Copy permalink