| <?xml version='1.0'?> <!--*-nxml-*--> |
| <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
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| Copyright 2013 Lennart Poettering |
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| |
| <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 service 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 service 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><constant>-EALREADY</constant></term> |
| |
| <listitem><para>The caller already is the owner of the |
| specified name.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><constant>-EEXIST</constant></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><constant>-ESRCH</constant></term> |
| |
| <listitem><para>It was attempted to release a name that is |
| currently not registered on the bus.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><constant>-EADDRINUSE</constant></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><constant>-EINVAL</constant></term> |
| |
| <listitem><para>A specified parameter is invalid. This is also |
| generated when the requested name is a special service name |
| reserved by the D-Bus specification, or when the operation is |
| requested on a connection that does not refer to a |
| bus.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><constant>-ENOTCONN</constant></term> |
| |
| <listitem><para>The bus connection has been |
| disconnected.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><constant>-ECHILD</constant></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 project='die-net'><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> |