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ModuleAlgorithm.html

ModuleAlgorithm.html 24.63 KB

<!DOCTYPE html>
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 <a href="Algorithms.html">Taskflow Algorithms</a> &raquo;
 Module Algorithm
 </h1>
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 <h3>Contents</h3>
 <ul>
 <li><a href="#ModuleAlgorithmInclude">Include the Header</a></li>
 <li><a href="#WhatIsAModuleTask">What is a Module Task</a></li>
 <li><a href="#CreateAModuleTaskOverACustomGraph">Create a Module Task over a Custom Graph</a></li>
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Taskflow provides template methods that let users create reusable building blocks called modules. Users can connect modules together to build more complex parallel algorithms.<section id="ModuleAlgorithmInclude"><h2><a href="#ModuleAlgorithmInclude">Include the Header</a></h2>You need to include the header file, <code><a href="module_8hpp_source.html" class="m-doc">taskflow/algorithm/module.hpp</a></code>, for creating a module task over a schedulable graph target.<pre class="m-code">#include &lt;taskflow/algorithm/module.hpp&gt;</pre></section><section id="WhatIsAModuleTask"><h2><a href="#WhatIsAModuleTask">What is a Module Task</a></h2>Similar to <a href="ComposableTasking.html" class="m-doc">Composable Tasking</a>, but in a more general setting, the template function <a href="namespacetf.html#ad13f8d0b6628d895792570515497139c" class="m-doc">tf::make_module_task</a> allows you to create a task over a <a href="classtf_1_1Taskflow.html" class="m-doc">Taskflow</a> graph that can be executed by an executor. This provides a flexible mechanism to encapsulate and reuse complex task logic within your Taskflow applications. The following example demonstrates how to create and launch multiple <a href="classtf_1_1Taskflow.html" class="m-doc">Taskflow</a> graphs in parallel using asynchronous tasking:<pre class="m-code">#include &lt;taskflow/taskflow.hpp&gt;
#include &lt;taskflow/algorithm/module.hpp&gt;

int main() {

tf::Executor executor;
 
 tf::Taskflow A;
 tf::Taskflow B;
 tf::Taskflow C;
 tf::Taskflow D;
 
 A.emplace([](){ printf(&quot;Taskflow A\n&quot;); }); 
 B.emplace([](){ printf(&quot;Taskflow B\n&quot;); }); 
 C.emplace([](){ printf(&quot;Taskflow C\n&quot;); }); 
 D.emplace([](){ printf(&quot;Taskflow D\n&quot;); }); 
 
 // launch the four taskflows using asynchronous tasking
 executor.async(tf::make_module_task(A));
 executor.async(tf::make_module_task(B));
 executor.async(tf::make_module_task(C));
 executor.async(tf::make_module_task(D));
 executor.wait_for_all();

return 0;
}</pre><div class="m-graph"><svg style="width: 27.800rem; height: 4.400rem;" viewBox="0.00 0.00 278.00 44.00">
<g transform="scale(1 1) rotate(0) translate(4 40)">
<title>Taskflow</title>
<g class="m-node m-flat">
<title>A</title>
<ellipse cx="27" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="27" y="-14.12" font-family="Helvetica,sans-Serif" font-size="10.00">A</text>
</g>
<g class="m-node m-flat">
<title>B</title>
<ellipse cx="99" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="99" y="-14.12" font-family="Helvetica,sans-Serif" font-size="10.00">B</text>
</g>
<g class="m-node m-flat">
<title>C</title>
<ellipse cx="171" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="171" y="-14.12" font-family="Helvetica,sans-Serif" font-size="10.00">C</text>
</g>
<g class="m-node m-flat">
<title>D</title>
<ellipse cx="243" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="243" y="-14.12" font-family="Helvetica,sans-Serif" font-size="10.00">D</text>
</g>
</g>
</svg>
</div>Since the four taskflows are launched asynchronously without any dependencies between them, we can observe any order of the output message:<pre class="m-code"># one possible output
Taskflow B
Taskflow C
Taskflow A
Taskflow D

# another possible output
Taskflow D
Taskflow A
Taskflow B
Taskflow C</pre>If you need to enforce dependencies among these four taskflows, you can use dependent-async tasks. The example below launches the four taskflows one by one in sequential:<pre class="m-code">tf::Executor executor;

tf::Taskflow A;
tf::Taskflow B;
tf::Taskflow C;
tf::Taskflow D;

A.emplace([](){ printf(&quot;Taskflow A\n&quot;); }); 
B.emplace([](){ printf(&quot;Taskflow B\n&quot;); }); 
C.emplace([](){ printf(&quot;Taskflow C\n&quot;); }); 
D.emplace([](){ printf(&quot;Taskflow D\n&quot;); });

auto TA = executor.silent_dependent_async(tf::make_module_task(A));
auto TB = executor.silent_dependent_async(tf::make_module_task(B), TA);
auto TC = executor.silent_dependent_async(tf::make_module_task(C), TB);
auto [TD, FD] = executor.dependent_async(tf::make_module_task(D), TC);
FD.get();</pre><div class="m-graph"><svg style="width: 33.200rem; height: 4.400rem;" viewBox="0.00 0.00 332.00 44.00">
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<title>Taskflow</title>
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<ellipse cx="117" cy="-18" rx="27" ry="18"/>
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<ellipse cx="297" cy="-18" rx="27" ry="18"/>
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</g>
</g>
</svg>
</div><pre class="m-code"># dependent-async tasks enforce a sequential execution of the four taskflows
Taskflow A
Taskflow B
Taskflow C
Taskflow D</pre>The module task maker, <a href="namespacetf.html#ad13f8d0b6628d895792570515497139c" class="m-doc">tf::make_module_task</a>, operates similarly to <a href="classtf_1_1FlowBuilder.html#ac6f22228d4c2ea2e643c4b0d42c0e92a" class="m-doc">tf::Taskflow::composed_of</a>, but provides a more general interface that can be used beyond Taskflow. Specifically, the following two approaches achieve equivalent functionality:<pre class="m-code">// approach 1: composition using composed_of
tf::Task m1 = taskflow1.composed_of(taskflow2);

// approach 2: composition using make_module_task
tf::Task m1 = taskflow1.emplace(tf::make_module_task(taskflow2));</pre><aside class="m-note m-warning"><h4>Attention</h4>Similar to <a href="classtf_1_1FlowBuilder.html#ac6f22228d4c2ea2e643c4b0d42c0e92a" class="m-doc">tf::Taskflow::composed_of</a>, <a href="namespacetf.html#ad13f8d0b6628d895792570515497139c" class="m-doc">tf::make_module_task</a> does not assume ownership of the provided taskflow but a soft reference. You are responsible for ensuring that the encapsulated taskflow remains valid throughout its execution.</aside></section><section id="CreateAModuleTaskOverACustomGraph"><h2><a href="#CreateAModuleTaskOverACustomGraph">Create a Module Task over a Custom Graph</a></h2>In addition to encapsulate taskflow graphs, you can create a module task to schedule a custom graph target. A schedulable target (of type <code>T</code>) must define the method <code>T::graph()</code> that returns a reference to the <a href="classtf_1_1Graph.html" class="m-doc">tf::Graph</a> object managed by <code>T</code>. The following example defines a custom graph that can be scheduled through making module tasks:<pre class="m-code">struct CustomGraph {
 tf::Graph graph;
 CustomGraph() {
 // use flow builder to inherit all task creation methods in tf::Taskflow
 tf::FlowBuilder builder(graph);
 tf::Task task = builder.emplace([](){
 std::cout &lt;&lt; &quot;a task\n&quot;; // static task
 });
 }
 // returns a reference to the graph for taskflow composition
 Graph&amp; graph() { return graph; }
};

CustomGraph target;
executor.async(tf::make_module_task(target));</pre><aside class="m-note m-warning"><h4>Attention</h4>Users are responsible for ensuring the given custom graph remains valid throughout its execution. The executor does not assume ownership of the custom graph.</aside></section>
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Tsung-Wei Huang 提交于 2025年07月28日 17:42 +08:00 . updated docs

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 Module Algorithm
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 <h3>Contents</h3>
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 <li><a href="#ModuleAlgorithmInclude">Include the Header</a></li>
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<p>Taskflow provides template methods that let users create reusable building blocks called <em>modules</em>. Users can connect modules together to build more complex parallel algorithms.</p><section id="ModuleAlgorithmInclude"><h2><a href="#ModuleAlgorithmInclude">Include the Header</a></h2><p>You need to include the header file, <code><a href="module_8hpp_source.html" class="m-doc">taskflow/<wbr />algorithm/<wbr />module.hpp</a></code>, for creating a module task over a schedulable graph target.</p><pre class="m-code"><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;taskflow/algorithm/module.hpp&gt;</span></pre></section><section id="WhatIsAModuleTask"><h2><a href="#WhatIsAModuleTask">What is a Module Task</a></h2><p>Similar to <a href="ComposableTasking.html" class="m-doc">Composable Tasking</a>, but in a more general setting, the template function <a href="namespacetf.html#ad13f8d0b6628d895792570515497139c" class="m-doc">tf::<wbr />make_module_task</a> allows you to create a task over a <a href="classtf_1_1Taskflow.html" class="m-doc">Taskflow</a> graph that can be executed by an executor. This provides a flexible mechanism to encapsulate and reuse complex task logic within your Taskflow applications. The following example demonstrates how to create and launch multiple <a href="classtf_1_1Taskflow.html" class="m-doc">Taskflow</a> graphs in parallel using asynchronous tasking:</p><pre class="m-code"><span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;taskflow/taskflow.hpp&gt;</span>
<span class="cp">#include</span><span class="w"> </span><span class="cpf">&lt;taskflow/algorithm/module.hpp&gt;</span>

<span class="kt">int</span><span class="w"> </span><span class="nf">main</span><span class="p">()</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">Executor</span><span class="w"> </span><span class="n">executor</span><span class="p">;</span>
<span class="w"> </span>
<span class="w"> </span><span class="n">tf</span><span class="o">::</span><span class="n">Taskflow</span><span class="w"> </span><span class="n">A</span><span class="p">;</span>
<span class="w"> </span><span class="n">tf</span><span class="o">::</span><span class="n">Taskflow</span><span class="w"> </span><span class="n">B</span><span class="p">;</span>
<span class="w"> </span><span class="n">tf</span><span class="o">::</span><span class="n">Taskflow</span><span class="w"> </span><span class="n">C</span><span class="p">;</span>
<span class="w"> </span><span class="n">tf</span><span class="o">::</span><span class="n">Taskflow</span><span class="w"> </span><span class="n">D</span><span class="p">;</span>
<span class="w"> </span>
<span class="w"> </span><span class="n">A</span><span class="p">.</span><span class="n">emplace</span><span class="p">([](){</span><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Taskflow A</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">);</span><span class="w"> </span><span class="p">});</span><span class="w"> </span>
<span class="w"> </span><span class="n">B</span><span class="p">.</span><span class="n">emplace</span><span class="p">([](){</span><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Taskflow B</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">);</span><span class="w"> </span><span class="p">});</span><span class="w"> </span>
<span class="w"> </span><span class="n">C</span><span class="p">.</span><span class="n">emplace</span><span class="p">([](){</span><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Taskflow C</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">);</span><span class="w"> </span><span class="p">});</span><span class="w"> </span>
<span class="w"> </span><span class="n">D</span><span class="p">.</span><span class="n">emplace</span><span class="p">([](){</span><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Taskflow D</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">);</span><span class="w"> </span><span class="p">});</span><span class="w"> </span>
<span class="w"> </span>
<span class="w"> </span><span class="c1">// launch the four taskflows using asynchronous tasking</span>
<span class="w"> </span><span class="n">executor</span><span class="p">.</span><span class="n">async</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">A</span><span class="p">));</span>
<span class="w"> </span><span class="n">executor</span><span class="p">.</span><span class="n">async</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">B</span><span class="p">));</span>
<span class="w"> </span><span class="n">executor</span><span class="p">.</span><span class="n">async</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">C</span><span class="p">));</span>
<span class="w"> </span><span class="n">executor</span><span class="p">.</span><span class="n">async</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">D</span><span class="p">));</span>
<span class="w"> </span><span class="n">executor</span><span class="p">.</span><span class="n">wait_for_all</span><span class="p">();</span><span class="w"> </span>

<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="p">}</span></pre><div class="m-graph"><svg style="width: 27.800rem; height: 4.400rem;" viewBox="0.00 0.00 278.00 44.00">
<g transform="scale(1 1) rotate(0) translate(4 40)">
<title>Taskflow</title>
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<title>A</title>
<ellipse cx="27" cy="-18" rx="27" ry="18"/>
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<ellipse cx="171" cy="-18" rx="27" ry="18"/>
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</div><p>Since the four taskflows are launched asynchronously without any dependencies between them, we can observe any order of the output message:</p><pre class="m-code"><span class="c1"># one possible output</span>
Taskflow<span class="w"> </span>B
Taskflow<span class="w"> </span>C
Taskflow<span class="w"> </span>A
Taskflow<span class="w"> </span>D

<span class="c1"># another possible output</span>
Taskflow<span class="w"> </span>D
Taskflow<span class="w"> </span>A
Taskflow<span class="w"> </span>B
Taskflow<span class="w"> </span>C</pre><p>If you need to enforce dependencies among these four taskflows, you can use dependent-async tasks. The example below launches the four taskflows one by one in sequential:</p><pre class="m-code"><span class="n">tf</span><span class="o">::</span><span class="n">Executor</span><span class="w"> </span><span class="n">executor</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">A</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">B</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">C</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">D</span><span class="p">;</span>

<span class="n">A</span><span class="p">.</span><span class="n">emplace</span><span class="p">([](){</span><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Taskflow A</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">);</span><span class="w"> </span><span class="p">});</span><span class="w"> </span>
<span class="n">B</span><span class="p">.</span><span class="n">emplace</span><span class="p">([](){</span><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Taskflow B</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">);</span><span class="w"> </span><span class="p">});</span><span class="w"> </span>
<span class="n">C</span><span class="p">.</span><span class="n">emplace</span><span class="p">([](){</span><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Taskflow C</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">);</span><span class="w"> </span><span class="p">});</span><span class="w"> </span>
<span class="n">D</span><span class="p">.</span><span class="n">emplace</span><span class="p">([](){</span><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;Taskflow D</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">);</span><span class="w"> </span><span class="p">});</span><span class="w"> </span>

<span class="k">auto</span><span class="w"> </span><span class="n">TA</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">executor</span><span class="p">.</span><span class="n">silent_dependent_async</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">A</span><span class="p">));</span>
<span class="k">auto</span><span class="w"> </span><span class="n">TB</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">executor</span><span class="p">.</span><span class="n">silent_dependent_async</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">B</span><span class="p">),</span><span class="w"> </span><span class="n">TA</span><span class="p">);</span>
<span class="k">auto</span><span class="w"> </span><span class="n">TC</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">executor</span><span class="p">.</span><span class="n">silent_dependent_async</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">C</span><span class="p">),</span><span class="w"> </span><span class="n">TB</span><span class="p">);</span>
<span class="k">auto</span><span class="w"> </span><span class="p">[</span><span class="n">TD</span><span class="p">,</span><span class="w"> </span><span class="n">FD</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">executor</span><span class="p">.</span><span class="n">dependent_async</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">D</span><span class="p">),</span><span class="w"> </span><span class="n">TC</span><span class="p">);</span>
<span class="n">FD</span><span class="p">.</span><span class="n">get</span><span class="p">();</span></pre><div class="m-graph"><svg style="width: 33.200rem; height: 4.400rem;" viewBox="0.00 0.00 332.00 44.00">
<g transform="scale(1 1) rotate(0) translate(4 40)">
<title>Taskflow</title>
<g class="m-node m-flat">
<title>A</title>
<ellipse cx="27" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="27" y="-14.12" font-family="Helvetica,sans-Serif" font-size="10.00">A</text>
</g>
<g class="m-node m-flat">
<title>B</title>
<ellipse cx="117" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="117" y="-14.12" font-family="Helvetica,sans-Serif" font-size="10.00">B</text>
</g>
<g class="m-edge">
<title>A&#45;&gt;B</title>
<path d="M54.4,-18C61.89,-18 70.18,-18 78.2,-18"/>
<polygon points="78.1,-21.5 88.1,-18 78.1,-14.5 78.1,-21.5"/>
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<g class="m-node m-flat">
<title>C</title>
<ellipse cx="207" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="207" y="-14.12" font-family="Helvetica,sans-Serif" font-size="10.00">C</text>
</g>
<g class="m-edge">
<title>B&#45;&gt;C</title>
<path d="M144.4,-18C151.89,-18 160.18,-18 168.2,-18"/>
<polygon points="168.1,-21.5 178.1,-18 168.1,-14.5 168.1,-21.5"/>
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<title>D</title>
<ellipse cx="297" cy="-18" rx="27" ry="18"/>
<text text-anchor="middle" x="297" y="-14.12" font-family="Helvetica,sans-Serif" font-size="10.00">D</text>
</g>
<g class="m-edge">
<title>C&#45;&gt;D</title>
<path d="M234.4,-18C241.89,-18 250.18,-18 258.2,-18"/>
<polygon points="258.1,-21.5 268.1,-18 258.1,-14.5 258.1,-21.5"/>
</g>
</g>
</svg>
</div><pre class="m-code"><span class="c1"># dependent-async tasks enforce a sequential execution of the four taskflows</span>
Taskflow<span class="w"> </span>A
Taskflow<span class="w"> </span>B
Taskflow<span class="w"> </span>C
Taskflow<span class="w"> </span>D</pre><p>The module task maker, <a href="namespacetf.html#ad13f8d0b6628d895792570515497139c" class="m-doc">tf::<wbr />make_module_task</a>, operates similarly to <a href="classtf_1_1FlowBuilder.html#ac6f22228d4c2ea2e643c4b0d42c0e92a" class="m-doc">tf::<wbr />Taskflow::<wbr />composed_of</a>, but provides a more general interface that can be used beyond Taskflow. Specifically, the following two approaches achieve equivalent functionality:</p><pre class="m-code"><span class="c1">// approach 1: composition using composed_of</span>
<span class="n">tf</span><span class="o">::</span><span class="n">Task</span><span class="w"> </span><span class="n">m1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">taskflow1</span><span class="p">.</span><span class="n">composed_of</span><span class="p">(</span><span class="n">taskflow2</span><span class="p">);</span>

<span class="c1">// approach 2: composition using make_module_task</span>
<span class="n">tf</span><span class="o">::</span><span class="n">Task</span><span class="w"> </span><span class="n">m1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">taskflow1</span><span class="p">.</span><span class="n">emplace</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">taskflow2</span><span class="p">));</span></pre><aside class="m-note m-warning"><h4>Attention</h4><p>Similar to <a href="classtf_1_1FlowBuilder.html#ac6f22228d4c2ea2e643c4b0d42c0e92a" class="m-doc">tf::<wbr />Taskflow::<wbr />composed_of</a>, <a href="namespacetf.html#ad13f8d0b6628d895792570515497139c" class="m-doc">tf::<wbr />make_module_task</a> does not assume ownership of the provided taskflow but a soft reference. You are responsible for ensuring that the encapsulated taskflow remains valid throughout its execution.</p></aside></section><section id="CreateAModuleTaskOverACustomGraph"><h2><a href="#CreateAModuleTaskOverACustomGraph">Create a Module Task over a Custom Graph</a></h2><p>In addition to encapsulate taskflow graphs, you can create a module task to schedule a custom graph target. A schedulable target (of type <code>T</code>) must define the method <code>T::graph()</code> that returns a reference to the <a href="classtf_1_1Graph.html" class="m-doc">tf::<wbr />Graph</a> object managed by <code>T</code>. The following example defines a custom graph that can be scheduled through making module tasks:</p><pre class="m-code"><span class="k">struct</span><span class="w"> </span><span class="nc">CustomGraph</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">Graph</span><span class="w"> </span><span class="n">graph</span><span class="p">;</span>
<span class="w"> </span><span class="n">CustomGraph</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="c1">// use flow builder to inherit all task creation methods in tf::Taskflow</span>
<span class="w"> </span><span class="n">tf</span><span class="o">::</span><span class="n">FlowBuilder</span><span class="w"> </span><span class="nf">builder</span><span class="p">(</span><span class="n">graph</span><span class="p">);</span>
<span class="w"> </span><span class="n">tf</span><span class="o">::</span><span class="n">Task</span><span class="w"> </span><span class="n">task</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">builder</span><span class="p">.</span><span class="n">emplace</span><span class="p">([](){</span>
<span class="w"> </span><span class="n">std</span><span class="o">::</span><span class="n">cout</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="s">&quot;a task</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">;</span><span class="w"> </span><span class="c1">// static task</span>
<span class="w"> </span><span class="p">});</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="c1">// returns a reference to the graph for taskflow composition</span>
<span class="w"> </span><span class="n">Graph</span><span class="o">&amp;</span><span class="w"> </span><span class="n">graph</span><span class="p">()</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">graph</span><span class="p">;</span><span class="w"> </span><span class="p">}</span>
<span class="p">};</span>

<span class="n">CustomGraph</span><span class="w"> </span><span class="n">target</span><span class="p">;</span>
<span class="n">executor</span><span class="p">.</span><span class="n">async</span><span class="p">(</span><span class="n">tf</span><span class="o">::</span><span class="n">make_module_task</span><span class="p">(</span><span class="n">target</span><span class="p">));</span></pre><aside class="m-note m-warning"><h4>Attention</h4><p>Users are responsible for ensuring the given custom graph remains valid throughout its execution. The executor does not assume ownership of the custom graph.</p></aside></section>
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