229 lines
9.9 KiB
XML
229 lines
9.9 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
|
||
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
||
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
||
|
||
<!--
|
||
This file is part of systemd.
|
||
|
||
Copyright 2013 Lennart Poettering
|
||
|
||
systemd is free software; you can redistribute it and/or modify it
|
||
under the terms of the GNU Lesser General Public License as published by
|
||
the Free Software Foundation; either version 2.1 of the License, or
|
||
(at your option) any later version.
|
||
|
||
systemd is distributed in the hope that it will be useful, but
|
||
WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
Lesser General Public License for more details.
|
||
|
||
You should have received a copy of the GNU Lesser General Public License
|
||
along with systemd; If not, see <http://www.gnu.org/licenses/>.
|
||
-->
|
||
|
||
<refentry id="sd_bus_request_name">
|
||
|
||
<refentryinfo>
|
||
<title>sd_bus_request_name</title>
|
||
<productname>systemd</productname>
|
||
|
||
<authorgroup>
|
||
<author>
|
||
<contrib>Developer</contrib>
|
||
<firstname>Lennart</firstname>
|
||
<surname>Poettering</surname>
|
||
<email>lennart@poettering.net</email>
|
||
</author>
|
||
</authorgroup>
|
||
</refentryinfo>
|
||
|
||
<refmeta>
|
||
<refentrytitle>sd_bus_request_name</refentrytitle>
|
||
<manvolnum>3</manvolnum>
|
||
</refmeta>
|
||
|
||
<refnamediv>
|
||
<refname>sd_bus_request_name</refname>
|
||
<refname>sd_bus_release_name</refname>
|
||
<refpurpose>Request or release a well-known name on a bus</refpurpose>
|
||
</refnamediv>
|
||
|
||
<refsynopsisdiv>
|
||
<funcsynopsis>
|
||
<funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
|
||
|
||
<funcprototype>
|
||
<funcdef>int <function>sd_bus_request_name</function></funcdef>
|
||
<paramdef>sd_bus* <parameter>bus</parameter></paramdef>
|
||
<paramdef>const char *<parameter>name</parameter></paramdef>
|
||
<paramdef>uint64_t <parameter>flags</parameter></paramdef>
|
||
</funcprototype>
|
||
|
||
<funcprototype>
|
||
<funcdef>int <function>sd_bus_release_name</function></funcdef>
|
||
<paramdef>sd_bus* <parameter>bus</parameter></paramdef>
|
||
<paramdef>const char *<parameter>name</parameter></paramdef>
|
||
</funcprototype>
|
||
</funcsynopsis>
|
||
</refsynopsisdiv>
|
||
|
||
<refsect1>
|
||
<title>Description</title>
|
||
|
||
<para><function>sd_bus_request_name()</function> requests
|
||
a well-known name on a bus. It takes a bus connection,
|
||
a valid bus name and a flags parameter. The flags
|
||
parameter is a combination of the following
|
||
flags:</para>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname></term>
|
||
|
||
<listitem><para>After acquiring the
|
||
name successfully, permit other peers
|
||
to take over the name when they try to
|
||
acquire it with the
|
||
<varname>SD_BUS_NAME_REPLACE_EXISTING</varname>
|
||
flag set. If
|
||
<varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname>
|
||
is not set on the original request,
|
||
such a request by other peers will be
|
||
denied.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>SD_BUS_NAME_REPLACE_EXISTING</varname></term>
|
||
|
||
<listitem><para>Take over the name
|
||
if it is already acquired by another
|
||
peer, and that other peer has permitted
|
||
takeover by setting
|
||
<varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname>
|
||
while acquiring it.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>SD_BUS_NAME_QUEUE</varname></term>
|
||
|
||
<listitem><para>Queue the acquisition
|
||
of the name when the name is already
|
||
taken.</para></listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
|
||
<para><function>sd_bus_release_name()</function> releases
|
||
an acquired well-known name. It takes a bus connection
|
||
and a valid bus name as parameters.</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Return Value</title>
|
||
|
||
<para>On success, these calls return 0 or a positive
|
||
integer. On failure, these calls return a negative
|
||
errno-style error code.</para>
|
||
|
||
<para>If <varname>SD_BUS_NAME_QUEUE</varname> is
|
||
specified, <function>sd_bus_request_name()</function>
|
||
will return 0 when the name is already taken by
|
||
another peer and the client has been added to the
|
||
queue for the name. In that case, the caller can
|
||
subscribe to <literal>NameOwnerChanged</literal>
|
||
signals to be notified when the name is successfully
|
||
acquired. <function>sd_bus_request_name()</function>
|
||
returns > 0 when the name has immediately been
|
||
acquired successfully.</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Errors</title>
|
||
|
||
<para>Returned errors may indicate the following problems:</para>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><varname>-EALREADY</varname></term>
|
||
|
||
<listitem><para>The caller already is
|
||
the owner of the specified
|
||
name.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>-EEXIST</varname></term>
|
||
|
||
<listitem><para>The name has already
|
||
been acquired by a different peer, and
|
||
SD_BUS_NAME_REPLACE_EXISTING was not
|
||
specified or the other peer did not
|
||
specify SD_BUS_NAME_ALLOW_REPLACEMENT
|
||
while acquiring the
|
||
name.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>-ESRCH</varname></term>
|
||
|
||
<listitem><para>It was attempted to
|
||
release a name that is currently not
|
||
registered on the
|
||
bus.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>-EADDRINUSE</varname></term>
|
||
|
||
<listitem><para>It was attempted to
|
||
release a name that is owned by a
|
||
different peer on the
|
||
bus.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>-EINVAL</varname></term>
|
||
|
||
<listitem><para>A specified parameter
|
||
is invalid.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>-ENOTCONN</varname></term>
|
||
|
||
<listitem><para>The bus connection has
|
||
been disconnected.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>-ECHILD</varname></term>
|
||
|
||
<listitem><para>The bus connection has
|
||
been created in a different process
|
||
than the current one.</para></listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Notes</title>
|
||
|
||
<para>The <function>sd_bus_acquire_name()</function>
|
||
and <function>sd_bus_release_name()</function>
|
||
interfaces are available as a shared library, which can
|
||
be compiled and linked to with the
|
||
<constant>libsystemd</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||
file.</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>See Also</title>
|
||
|
||
<para>
|
||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>sd_bus_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
||
</para>
|
||
</refsect1>
|
||
|
||
</refentry>
|