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<title>Owning bus names: GIO Reference Manual</title>
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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="id-1.5.5.4"></a>Owning bus names</h2></div></div></div>
<p>
Using dbus-glib, you typically call RequestName manually
to own a name, like in the following excerpt:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
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<td class="listing_code"><pre class="programlisting">error <span class="gtkdoc opt">=</span> NULL<span class="gtkdoc opt">;</span>
res <span class="gtkdoc opt">=</span> <span class="function">dbus_g_proxy_call</span> <span class="gtkdoc opt">(</span>system_bus_proxy<span class="gtkdoc opt">,</span>
<span class="string">"RequestName"</span><span class="gtkdoc opt">,</span>
<span class="gtkdoc opt">&</span>error<span class="gtkdoc opt">,</span>
G_TYPE_STRING<span class="gtkdoc opt">,</span> NAME_TO_CLAIM<span class="gtkdoc opt">,</span>
G_TYPE_UINT<span class="gtkdoc opt">,</span> DBUS_NAME_FLAG_ALLOW_REPLACEMENT<span class="gtkdoc opt">,</span>
G_TYPE_INVALID<span class="gtkdoc opt">,</span>
G_TYPE_UINT<span class="gtkdoc opt">, &</span>result<span class="gtkdoc opt">,</span>
G_TYPE_INVALID<span class="gtkdoc opt">);</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(!</span>res<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span>error <span class="gtkdoc opt">!=</span> NULL<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="function"><a href="../glib-Message-Logging.html#g-warning">g_warning</a></span> <span class="gtkdoc opt">(</span><span class="string">"Failed to acquire %s: %s"</span><span class=";gtkdoc opt">,</span>
NAME_TO_CLAIM<span class="gtkdoc opt">,</span> error<span class="gtkdoc opt">-></span>message<span class="gtkdoc opt">);</span>
<span class="function"><a href="../glib-Error-Reporting.html#g-error-free">g_error_free</a></span> <span class="gtkdoc opt">(</span>error<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="keyword">else</span>
<span class="gtkdoc opt">{</span>
<span class="function"><a href="../glib-Message-Logging.html#g-warning">g_warning</a></span> <span class="gtkdoc opt">(</span><span class="string">"Failed to acquire %s"</span><span class="gtkdoc opt">,</span> NAME_TO_CLAIM<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="keyword">goto</span> out<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span>result <span class="gtkdoc opt">!=</span> DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span>error <span class="gtkdoc opt">!=</span> NULL<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="function"><a href="../glib-Message-Logging.html#g-warning">g_warning</a></span> <span class="gtkdoc opt">(</span><span class="string">"Failed to acquire %s: %s"</span><span class=";gtkdoc opt">,</span>
NAME_TO_CLAIM<span class="gtkdoc opt">,</span> error<span class="gtkdoc opt">-></span>message<span class="gtkdoc opt">);</span>
<span class="function"><a href="../glib-Error-Reporting.html#g-error-free">g_error_free</a></span> <span class="gtkdoc opt">(</span>error<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="keyword">else</span>
<span class="gtkdoc opt">{</span>
<span class="function"><a href="../glib-Message-Logging.html#g-warning">g_warning</a></span> <span class="gtkdoc opt">(</span><span class="string">"Failed to acquire %s"</span><span class="gtkdoc opt">,</span> NAME_TO_CLAIM<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="function">exit</span> <span class="gtkdoc opt">(</span><span class="number">1</span><span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="function">dbus_g_proxy_add_signal</span> <span class="gtkdoc opt">(</span>system_bus_proxy<span class="gtkdoc opt">,</span> <span class="string">"NameLost"</span><span class="gtkdoc opt">,</span>
G_TYPE_STRING<span class="gtkdoc opt">,</span> G_TYPE_INVALID<span class="gtkdoc opt">);</span>
<span class="function">dbus_g_proxy_connect_signal</span> <span class="gtkdoc opt">(</span>system_bus_proxy<span class="gtkdoc opt">,</span> <span class="string">"NameLost"</span><span class="gtkdoc opt">,</span>
<span class="function"><a href="../gobject-Closures.html#G-CALLBACK:CAPS">G_CALLBACK</a></span> <span class="gtkdoc opt">(</span>on_name_lost<span class="gtkdoc opt">),</span> NULL<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
<span class="comment">/* further setup ... */</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
</p>
<p>
While you can do things this way with GDBus too, using
<a class="link" href="GDBusProxy.html#g-dbus-proxy-call-sync" title="g_dbus_proxy_call_sync ()"><code class="function">g_dbus_proxy_call_sync()</code></a>, it is much nicer to use the high-level API
for this:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
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<td class="listing_code"><pre class="programlisting"><span class="gtkdoc kwb">static void</span>
<span class="function">on_name_acquired</span> <span class="gtkdoc opt">(</span>GDBusConnection <span class="gtkdoc opt">*</span>connection<span class="gtkdoc opt">,</span>
<span class="gtkdoc kwb">const</span> gchar <span class="gtkdoc opt">*</span>name<span class="gtkdoc opt">,</span>
gpointer user_data<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="comment">/* further setup ... */</span>
<span class="gtkdoc opt">}</span>
<span class="comment">/* ... */</span>
owner_id <span class="gtkdoc opt">=</span> <span class="function"><a href="gio-Owning-Bus-Names.html#g-bus-own-name">g_bus_own_name</a></span> <span class="gtkdoc opt">(</span>G_BUS_TYPE_SYSTEM<span class="gtkdoc opt">,="#A020F0"></span>
NAME_TO_CLAIM<span class="gtkdoc opt">,</span>
G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT<span class="gtkdoc opt">,</span>
on_bus_acquired<span class="gtkdoc opt">,</span>
on_name_acquired<span class="gtkdoc opt">,</span>
on_name_lost<span class="gtkdoc opt">,</span>
NULL<span class="gtkdoc opt">,</span>
NULL<span class="gtkdoc opt">);</span>
<span class="function"><a href="../glib-The-Main-Event-Loop.html#g-main-loop-run">g_main_loop_run</a></span> <span class="gtkdoc opt">(</span>loop<span class="gtkdoc opt">);</span>
<span class="function"><a href="gio-Owning-Bus-Names.html#g-bus-unown-name">g_bus_unown_name</a></span> <span class="gtkdoc opt">(</span>owner_id<span class="gtkdoc opt">);</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
Note that <a class="link" href="gio-Owning-Bus-Names.html#g-bus-own-name" title="g_bus_own_name ()"><code class="function">g_bus_own_name()</code></a> works asynchronously and requires
you to enter your mainloop to await the <code class="function">on_name_aquired()</code>
callback. Also note that in order to avoid race conditions (e.g.
when your service is activated by a method call), you have to export
your manager object <span class="emphasis"><em>before</em></span> acquiring the
name. The <code class="function">on_bus_acquired()</code> callback is the right place to do
such preparations.
</p>
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