man/sd_bus_add_object_manager.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="sd_bus_add_object_manager"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>sd_bus_add_object_manager</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>sd_bus_add_object_manager</refentrytitle>
  16     <manvolnum>3</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>sd_bus_add_object_manager</refname>
  21
  22     <refpurpose>Add a D-Bus object manager for a D-Bus object sub-tree</refpurpose>
  23   </refnamediv>
  24
  25   <refsynopsisdiv>
  26     <funcsynopsis>
  27       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  28
  29       <funcprototype>
  30         <funcdef>int <function>sd_bus_add_object_manager</function></funcdef>
  31         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  32         <paramdef>sd_bus_slot **<parameter>slot</parameter></paramdef>
  33         <paramdef>const char *<parameter>path</parameter></paramdef>
  34       </funcprototype>
  35     </funcsynopsis>
  36   </refsynopsisdiv>
  37
  38   <refsect1>
  39     <title>Description</title>
  40
  41     <para><function>sd_bus_add_object_manager()</function> installs a handler for the given path
  42     that implements the <function>GetManagedObjects()</function> method of the
  43     <constant>org.freedesktop.DBus.ObjectManager</constant> interface. See
  44     <ulink url="https://dbus.freedesktop.org/doc/dbus-specification.html#standard-interfaces-objectmanager">
  45     org.freedesktop.DBus.ObjectManager</ulink> for more information.</para>
  46
  47     <para>To implement the <function>InterfacesAdded</function> and
  48     <function>InterfacesRemoved</function> signals of the
  49     <constant>org.freedesktop.DBus.ObjectManager</constant> interface, call
  50     <citerefentry><refentrytitle>sd_bus_emit_interfaces_added</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
  51     <citerefentry><refentrytitle>sd_bus_emit_interfaces_removed</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  52     whenever interfaces are added or removed from the sub-tree, respectively.</para>
  53
  54     <para>When <function>sd_bus_add_object_manager()</function> succeeds, a slot is created
  55     internally. If the output parameter <replaceable>slot</replaceable> is <constant>NULL</constant>,
  56     a "floating" slot object is created, see
  57     <citerefentry><refentrytitle>sd_bus_slot_set_floating</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
  58     Otherwise, a pointer to the slot object is returned. In that case, the reference to the slot
  59     object should be dropped when the object manager is not needed anymore, see
  60     <citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
  61     </para>
  62   </refsect1>
  63
  64   <refsect1>
  65     <title>Return Value</title>
  66
  67     <para>On success, <function>sd_bus_add_object_manager()</function> returns a non-negative
  68     integer. On failure, it returns a negative errno-style error code.</para>
  69
  70     <refsect2>
  71       <title>Errors</title>
  72
  73       <para>Returned errors may indicate the following problems:</para>
  74
  75       <variablelist>
  76         <varlistentry>
  77           <term><constant>-EINVAL</constant></term>
  78
  79           <listitem><para>One of the required parameters is <constant>NULL</constant> or
  80           <parameter>path</parameter> is not a valid object path.
  81           </para></listitem>
  82         </varlistentry>
  83
  84         <varlistentry>
  85           <term><constant>-ENOPKG</constant></term>
  86
  87           <listitem><para>The bus cannot be resolved.</para></listitem>
  88         </varlistentry>
  89
  90         <varlistentry>
  91           <term><constant>-ECHILD</constant></term>
  92
  93           <listitem><para>The bus was created in a different process.</para></listitem>
  94         </varlistentry>
  95
  96         <varlistentry>
  97           <term><constant>-ENOMEM</constant></term>
  98
  99           <listitem><para>Memory allocation failed.</para></listitem>
 100         </varlistentry>
 101       </variablelist>
 102     </refsect2>
 103   </refsect1>
 104
 105   <xi:include href="libsystemd-pkgconfig.xml" />
 106
 107   <refsect1>
 108     <title>See Also</title>
 109
 110     <para>
 111       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 112       <citerefentry><refentrytitle>busctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 113       <citerefentry><refentrytitle>sd_bus_add_object_vtable</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 114       <citerefentry><refentrytitle>sd_bus_emit_interfaces_added</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 115       <citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 116     </para>
 117   </refsect1>
 118 </refentry>