man/sd_bus_new.xml

   1 <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4
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   6   This file is part of systemd.
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   8   Copyright 2014 Zbigniew Jędrzejewski-Szmek
   9
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  23
  24 <refentry id="sd_bus_new" conditional="ENABLE_KDBUS">
  25
  26   <refentryinfo>
  27     <title>sd_bus_new</title>
  28     <productname>systemd</productname>
  29
  30     <authorgroup>
  31       <author>
  32         <contrib>A monkey with a typewriter</contrib>
  33         <firstname>Zbigniew</firstname>
  34         <surname>Jędrzejewski-Szmek</surname>
  35         <email>zbyszek@in.waw.pl</email>
  36       </author>
  37     </authorgroup>
  38   </refentryinfo>
  39
  40   <refmeta>
  41     <refentrytitle>sd_bus_new</refentrytitle>
  42     <manvolnum>3</manvolnum>
  43   </refmeta>
  44
  45   <refnamediv>
  46     <refname>sd_bus_new</refname>
  47     <refname>sd_bus_ref</refname>
  48     <refname>sd_bus_unref</refname>
  49
  50     <refpurpose>Create a new bus object and create or destroy references to it</refpurpose>
  51   </refnamediv>
  52
  53   <refsynopsisdiv>
  54     <funcsynopsis>
  55       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  56
  57       <funcprototype>
  58         <funcdef>int <function>sd_bus_new</function></funcdef>
  59         <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
  60       </funcprototype>
  61
  62       <funcprototype>
  63         <funcdef>sd_bus *<function>sd_bus_ref</function></funcdef>
  64         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  65       </funcprototype>
  66
  67       <funcprototype>
  68         <funcdef>sd_bus *<function>sd_bus_unref</function></funcdef>
  69         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  70       </funcprototype>
  71     </funcsynopsis>
  72   </refsynopsisdiv>
  73
  74   <refsect1>
  75     <title>Description</title>
  76
  77     <para><function>sd_bus_new()</function> creates a new bus
  78     object. This object is reference-counted, and will be destroyed
  79     when all references are gone. Initially, the caller of this
  80     function owns the sole reference.</para>
  81
  82     <para><function>sd_bus_ref()</function> creates a new reference to
  83     <parameter>bus</parameter>. This bus object will not be destroyed
  84     until <function>sd_bus_unref()</function> has been called as many
  85     times plus once more. Once the reference count has dropped to
  86     zero, <parameter>bus</parameter> cannot be used anymore, so
  87     further calls to <function>sd_bus_ref()</function> or
  88     <function>sd_bus_unref()</function> are illegal.</para>
  89
  90     <para><function>sd_bus_unref()</function> destroys a reference to
  91     <parameter>bus</parameter>.</para>
  92   </refsect1>
  93
  94   <refsect1>
  95     <title>Return Value</title>
  96
  97     <para>On success, <function>sd_bus_new()</function> returns 0 or a
  98     positive integer. On failure, it returns a negative errno-style
  99     error code.</para>
 100
 101     <para><function>sd_bus_ref</function> always returns the argument.
 102     </para>
 103
 104     <para><function>sd_bus_unref</function> always returns
 105     <constant>NULL</constant>.</para>
 106   </refsect1>
 107
 108   <refsect1>
 109     <title>Errors</title>
 110
 111     <para>Returned errors may indicate the following problems:</para>
 112
 113     <variablelist>
 114       <varlistentry>
 115         <term><constant>-ENOMEM</constant></term>
 116
 117         <listitem><para>Memory allocation failed.</para></listitem>
 118       </varlistentry>
 119     </variablelist>
 120   </refsect1>
 121
 122   <refsect1>
 123     <title>Notes</title>
 124
 125     <para><function>sd_bus_new()</function> and other functions
 126     described here are available as a shared library, which can be
 127     compiled and linked to with the
 128     <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 129     file.</para>
 130   </refsect1>
 131
 132   <refsect1>
 133     <title>See Also</title>
 134
 135     <para>
 136       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 137       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 138       <citerefentry><refentrytitle>sd_bus_open_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 139       <citerefentry><refentrytitle>sd_bus_open_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 140       <citerefentry><refentrytitle>sd_bus_default_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 141       <citerefentry><refentrytitle>sd_bus_default_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 142     </para>
 143   </refsect1>
 144
 145 </refentry>