Insane_DNS/libraries/asio-1.28.1/doc/asio/reference/spawn/overload6.html

123 lines
9.7 KiB
HTML

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>spawn (6 of 13 overloads)</title>
<link rel="stylesheet" href="../../../boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="../../../index.html" title="Asio">
<link rel="up" href="../spawn.html" title="spawn">
<link rel="prev" href="overload5.html" title="spawn (5 of 13 overloads)">
<link rel="next" href="overload7.html" title="spawn (7 of 13 overloads)">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../../asio.png"></td></tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="overload5.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../spawn.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="overload7.html"><img src="../../../next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="asio.reference.spawn.overload6"></a><a class="link" href="overload6.html" title="spawn (6 of 13 overloads)">spawn (6 of 13 overloads)</a>
</h4></div></div></div>
<p>
Start a new stackful coroutine, inheriting the executor of another.
</p>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
<span class="keyword">typename</span> <a class="link" href="../Executor1.html" title="Executor requirements">Executor</a><span class="special">,</span>
<span class="keyword">typename</span> <span class="identifier">StackAllocator</span><span class="special">,</span>
<span class="keyword">typename</span> <span class="identifier">F</span><span class="special">,</span>
<span class="keyword">typename</span> <span class="identifier">CompletionToken</span> <span class="special">=</span> <a class="link" href="../asynchronous_operations.html#asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a><span class="special">&gt;</span>
<a class="link" href="../asynchronous_operations.html#asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type"><span class="emphasis"><em>DEDUCED</em></span></a> <span class="identifier">spawn</span><span class="special">(</span>
<span class="keyword">const</span> <span class="identifier">basic_yield_context</span><span class="special">&lt;</span> <span class="identifier">Executor</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">ctx</span><span class="special">,</span>
<span class="identifier">allocator_arg_t</span> <span class="special">,</span>
<span class="identifier">StackAllocator</span> <span class="special">&amp;&amp;</span> <span class="identifier">stack_allocator</span><span class="special">,</span>
<span class="identifier">F</span> <span class="special">&amp;&amp;</span> <span class="identifier">function</span><span class="special">,</span>
<span class="identifier">CompletionToken</span> <span class="special">&amp;&amp;</span> <span class="identifier">token</span> <span class="special">=</span> <a class="link" href="../asynchronous_operations.html#asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a><span class="special">,</span>
<span class="keyword">typename</span> <span class="identifier">constraint</span><span class="special">&lt;</span> <span class="identifier">is_executor</span><span class="special">&lt;</span> <span class="identifier">Executor</span> <span class="special">&gt;::</span><span class="identifier">value</span><span class="special">||</span><span class="identifier">execution</span><span class="special">::</span><span class="identifier">is_executor</span><span class="special">&lt;</span> <span class="identifier">Executor</span> <span class="special">&gt;::</span><span class="identifier">value</span> <span class="special">&gt;::</span><span class="identifier">type</span> <span class="special">=</span> <span class="number">0</span><span class="special">);</span>
</pre>
<p>
This function is used to launch a new stackful coroutine using the specified
stack allocator.
</p>
<h6>
<a name="asio.reference.spawn.overload6.h0"></a>
<span><a name="asio.reference.spawn.overload6.parameters"></a></span><a class="link" href="overload6.html#asio.reference.spawn.overload6.parameters">Parameters</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl>
<dt><span class="term">ctx</span></dt>
<dd><p>
Identifies the current coroutine as a parent of the new coroutine.
This specifies that the new coroutine should inherit the executor
of the parent. For example, if the parent coroutine is executing
in a particular strand, then the new coroutine will execute in the
same strand.
</p></dd>
<dt><span class="term">stack_allocator</span></dt>
<dd><p>
Denotes the allocator to be used to allocate the underlying coroutine's
stack. The type must satisfy the stack-allocator concept defined
by the Boost.Context library.
</p></dd>
<dt><span class="term">function</span></dt>
<dd>
<p>
The coroutine function. The function must be callable the signature:
</p>
<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">function</span><span class="special">(</span><span class="identifier">basic_yield_context</span><span class="special">&lt;</span><span class="identifier">Executor</span><span class="special">&gt;</span> <span class="identifier">yield</span><span class="special">);</span>
</pre>
</dd>
<dt><span class="term">token</span></dt>
<dd><p>
The <a class="link" href="../../overview/model/completion_tokens.html" title="Completion Tokens">completion
token</a> that will handle the notification that the coroutine
has completed. If the return type <code class="computeroutput"><span class="identifier">R</span></code>
of <code class="computeroutput"><span class="identifier">function</span></code> is <code class="computeroutput"><span class="keyword">void</span></code>, the function signature of the
completion handler must be:
</p></dd>
</dl>
</div>
<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">exception_ptr</span><span class="special">);</span>
</pre>
<p>
Otherwise, the function signature of the completion handler must be:
</p>
<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">exception_ptr</span><span class="special">,</span> <span class="identifier">R</span><span class="special">);</span>
</pre>
<h6>
<a name="asio.reference.spawn.overload6.h1"></a>
<span><a name="asio.reference.spawn.overload6.completion_signature"></a></span><a class="link" href="overload6.html#asio.reference.spawn.overload6.completion_signature">Completion
Signature</a>
</h6>
<pre class="programlisting"><span class="keyword">void</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">exception_ptr</span><span class="special">,</span> <span class="identifier">R</span><span class="special">)</span>
</pre>
<p>
where <code class="computeroutput"><span class="identifier">R</span></code> is the return type
of the function object.
</p>
<h6>
<a name="asio.reference.spawn.overload6.h2"></a>
<span><a name="asio.reference.spawn.overload6.per_operation_cancellation"></a></span><a class="link" href="overload6.html#asio.reference.spawn.overload6.per_operation_cancellation">Per-Operation
Cancellation</a>
</h6>
<p>
The new thread of execution is created with a cancellation state that supports
<code class="computeroutput"><span class="identifier">cancellation_type</span><span class="special">::</span><span class="identifier">terminal</span></code> values only. To change the cancellation
state, call the <a class="link" href="../basic_yield_context.html" title="basic_yield_context"><code class="computeroutput"><span class="identifier">basic_yield_context</span></code></a> member function
<code class="computeroutput"><span class="identifier">reset_cancellation_state</span></code>.
</p>
</div>
<div class="copyright-footer">Copyright © 2003-2023 Christopher M. Kohlhoff<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
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>)
</p>
</div>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="overload5.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../spawn.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="overload7.html"><img src="../../../next.png" alt="Next"></a>
</div>
</body>
</html>