nt">// You can also manage backend in a thread-safe manner</span>
    <span class="special">{</span>
        <span class="identifier">sink_t</span><span class="special">::</span><span class="identifier">locked_backend_ptr</span> <span class="identifier">p</span> <span class="special">=</span> <span class="identifier">sink</span><span class="special">-&gt;</span><span class="identifier">locked_backend</span><span class="special">();</span>
        <span class="identifier">p</span><span class="special">-&gt;<