mirror of
https://github.com/systemd/systemd.git
synced 2024-11-24 02:33:36 +08:00
118 lines
4.7 KiB
XML
118 lines
4.7 KiB
XML
<?xml version='1.0'?>
|
||
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
||
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
||
|
||
<!--
|
||
SPDX-License-Identifier: LGPL-2.1+
|
||
-->
|
||
|
||
<refentry id="sd_bus_set_connected_signal">
|
||
|
||
<refentryinfo>
|
||
<title>sd_bus_set_connected_signal</title>
|
||
<productname>systemd</productname>
|
||
</refentryinfo>
|
||
|
||
<refmeta>
|
||
<refentrytitle>sd_bus_set_connected_signal</refentrytitle>
|
||
<manvolnum>3</manvolnum>
|
||
</refmeta>
|
||
|
||
<refnamediv>
|
||
<refname>sd_bus_set_connected_signal</refname>
|
||
<refname>sd_bus_get_connected_signal</refname>
|
||
|
||
<refpurpose>Control emmission of local connection establishment signal on bus connections</refpurpose>
|
||
</refnamediv>
|
||
|
||
<refsynopsisdiv>
|
||
<funcsynopsis>
|
||
<funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
|
||
|
||
<funcprototype>
|
||
<funcdef>int <function>sd_bus_set_connected_signal</function></funcdef>
|
||
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
||
<paramdef>int <parameter>b</parameter></paramdef>
|
||
</funcprototype>
|
||
|
||
<funcprototype>
|
||
<funcdef>int <function>sd_bus_get_connected_signal</function></funcdef>
|
||
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
||
</funcprototype>
|
||
|
||
</funcsynopsis>
|
||
</refsynopsisdiv>
|
||
|
||
<refsect1>
|
||
<title>Description</title>
|
||
|
||
<para><function>sd_bus_set_connected_signal()</function> may be used to control whether a local, synthetic
|
||
<function>Connected()</function> signal message shall be generated and enqueued for dispatching when the connection
|
||
is fully established. If the <parameter>b</parameter> parameter is zero the message is not generated (the default),
|
||
otherwise it is generated.</para>
|
||
|
||
<para><function>sd_bus_get_connected_signal()</function> may be used to query whether this feature is enabled. It
|
||
returns zero if not, positive otherwise.</para>
|
||
|
||
<para>The <function>Connected()</function> signal message is generated from the
|
||
<literal>org.freedesktop.DBus.Local</literal> service and interface, and
|
||
<literal>/org/freedesktop/DBus/Local</literal> object path. Use
|
||
<citerefentry><refentrytitle>sd_bus_match_signal_async</refentrytitle><manvolnum>3</manvolnum></citerefentry> to
|
||
match on this signal.</para>
|
||
|
||
<para>This message is particularly useful on slow transports where connections take a long time to be
|
||
established. This is especially the case when
|
||
<citerefentry><refentrytitle>sd_bus_set_watch_bind</refentrytitle><manvolnum>3</manvolnum></citerefentry> is
|
||
used. The signal is generated when the
|
||
<citerefentry><refentrytitle>sd_bus_is_ready</refentrytitle><manvolnum>3</manvolnum></citerefentry> returns
|
||
positive for the first time.</para>
|
||
|
||
<para>The <function>Connected()</function> signal corresponds with the <function>Disconnected()</function> signal
|
||
that is synthesized locally when the connection is terminated. The latter is generated unconditionally however,
|
||
unlike the former which needs to be enabled explicitly before it is generated, with
|
||
<function>sd_bus_set_connected_signal()</function>.</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Return Value</title>
|
||
|
||
<para>On success, these functions return 0 or a positive integer. On failure, they return a negative errno-style
|
||
error code.</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Errors</title>
|
||
|
||
<para>Returned errors may indicate the following problems:</para>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><constant>-ECHILD</constant></term>
|
||
|
||
<listitem><para>The bus connection has been created in a different process.</para></listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Notes</title>
|
||
|
||
<para><function>sd_bus_set_connected_signal()</function> and <function>sd_bus_get_connected_signal()</function> 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_match_signal_async</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>sd_bus_set_watch_bind</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>sd_bus_is_ready</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
||
</para>
|
||
</refsect1>
|
||
|
||
</refentry>
|