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<title>io_context::~io_context</title>
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<div class="titlepage"><div><div><h4 class="title">
<a name="asio.reference.io_context._io_context"></a><a class="link" href="_io_context.html" title="io_context::~io_context">io_context::~io_context</a>
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<p>
<a class="indexterm" name="asio.indexterm.io_context._io_context"></a>
Destructor.
</p>
<pre class="programlisting">~io_context();
</pre>
<p>
On destruction, the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a>
performs the following sequence of operations:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
For each service object <code class="computeroutput">svc</code> in the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a>
set, in reverse order of the beginning of service object lifetime,
performs <code class="computeroutput">svc->shutdown()</code>.
</li>
<li class="listitem">
Uninvoked handler objects that were scheduled for deferred invocation
on the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a>,
or any associated strand, are destroyed.
</li>
<li class="listitem">
For each service object <code class="computeroutput">svc</code> in the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a>
set, in reverse order of the beginning of service object lifetime,
performs <code class="computeroutput">delete static_cast<io_context::service*>(svc)</code>.
</li>
</ul></div>
<h6>
<a name="asio.reference.io_context._io_context.h0"></a>
<span><a name="asio.reference.io_context._io_context.remarks"></a></span><a class="link" href="_io_context.html#asio.reference.io_context._io_context.remarks">Remarks</a>
</h6>
<p>
The destruction sequence described above permits programs to simplify their
resource management by using <code class="computeroutput">shared_ptr<></code>. Where an
object's lifetime is tied to the lifetime of a connection (or some other
sequence of asynchronous operations), a <code class="computeroutput">shared_ptr</code> to the
object would be bound into the handlers for all asynchronous operations
associated with it. This works as follows:
</p>
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<li class="listitem">
When a single connection ends, all associated asynchronous operations
complete. The corresponding handler objects are destroyed, and all
<code class="computeroutput">shared_ptr</code> references to the objects are destroyed.
</li>
<li class="listitem">
To shut down the whole program, the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a>
function <code class="computeroutput">stop()</code> is called to terminate any <code class="computeroutput">run()</code>
calls as soon as possible. The <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a>
destructor defined above destroys all handlers, causing all <code class="computeroutput">shared_ptr</code>
references to all connection objects to be destroyed.
</li>
</ul></div>
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<td align="right"><div class="copyright-footer">Copyright © 2003-2020 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>)
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