mirror of
https://github.com/systemd/systemd.git
synced 2024-12-23 21:35:11 +03:00
113 lines
4.5 KiB
XML
113 lines
4.5 KiB
XML
<?xml version='1.0'?>
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
|
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
|
|
|
|
<refentry id="sd_bus_is_open"
|
|
xmlns:xi="http://www.w3.org/2001/XInclude">
|
|
|
|
<refentryinfo>
|
|
<title>sd_bus_is_open</title>
|
|
<productname>systemd</productname>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>sd_bus_is_open</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>sd_bus_is_open</refname>
|
|
<refname>sd_bus_is_ready</refname>
|
|
|
|
<refpurpose>Check whether the bus connection is open or ready</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_bus_is_open</function></funcdef>
|
|
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_bus_is_ready</function></funcdef>
|
|
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para><function>sd_bus_is_open()</function> checks whether the specified bus connection is open, i.e. in the
|
|
process of being established, already established or in the process of being torn down. It returns zero when the
|
|
connection has not been started yet
|
|
(i.e. <citerefentry><refentrytitle>sd_bus_start</refentrytitle><manvolnum>3</manvolnum></citerefentry> or some
|
|
equivalent call has not been invoked yet), or is fully terminated again (for example after
|
|
<citerefentry><refentrytitle>sd_bus_close</refentrytitle><manvolnum>3</manvolnum></citerefentry>), it returns
|
|
positive otherwise.</para>
|
|
|
|
<para><function>sd_bus_is_ready()</function> checks whether the specified connection is fully established,
|
|
i.e. completed the connection and authentication phases of the protocol and received the
|
|
<function>Hello()</function> method call response, and is not in the process of being torn down again. It returns
|
|
zero outside of this state, and positive otherwise. Effectively, this function returns positive while regular
|
|
messages can be sent or received on the connection.</para>
|
|
|
|
<para>The <parameter>bus</parameter> argument may be <constant>NULL</constant>, zero is also returned in
|
|
that case.</para>
|
|
|
|
<para>To be notified when the connection is fully established, use
|
|
<citerefentry><refentrytitle>sd_bus_set_connected_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
|
|
install a match for the <function>Connected()</function> signal on the
|
|
<literal>org.freedesktop.DBus.Local</literal> interface. To be notified when the connection is torn down again,
|
|
install a match for the <function>Disconnected()</function> signal on the
|
|
<literal>org.freedesktop.DBus.Local</literal> interface.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Return Value</title>
|
|
|
|
<para>Those functions return 0 if the bus is <emphasis>not</emphasis> in the given state, and a positive
|
|
integer when it is. On failure, a negative errno-style error code is returned.</para>
|
|
|
|
<refsect2>
|
|
<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, library or module instance.</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect2>
|
|
</refsect1>
|
|
|
|
<xi:include href="libsystemd-pkgconfig.xml" />
|
|
|
|
<refsect1>
|
|
<title>History</title>
|
|
<para><function>sd_bus_is_open()</function> and
|
|
<function>sd_bus_is_ready()</function> were added in version 237.</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_start</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_bus_close</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_bus_set_connected_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|