mirror of
https://github.com/systemd/systemd.git
synced 2024-11-23 10:13:34 +08:00
127 lines
5.3 KiB
XML
127 lines
5.3 KiB
XML
<?xml version='1.0'?>
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
|
|
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
|
|
|
|
<refentry id="sd_bus_close"
|
|
xmlns:xi="http://www.w3.org/2001/XInclude">
|
|
|
|
<refentryinfo>
|
|
<title>sd_bus_close</title>
|
|
<productname>systemd</productname>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>sd_bus_close</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>sd_bus_close</refname>
|
|
<refname>sd_bus_flush</refname>
|
|
<refname>sd_bus_default_flush_close</refname>
|
|
|
|
<refpurpose>Close and flush a bus connection</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
|
|
|
|
<funcprototype>
|
|
<funcdef>void <function>sd_bus_close</function></funcdef>
|
|
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_bus_flush</function></funcdef>
|
|
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>void <function>sd_bus_default_flush_close</function></funcdef>
|
|
<paramdef>void</paramdef>
|
|
</funcprototype>
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para><function>sd_bus_close()</function> disconnects the specified bus connection. When this
|
|
call is invoked and the specified bus object refers to an active connection it is immediately
|
|
terminated. No further messages may be sent or received on it. Any messages queued in the bus
|
|
object (both incoming and outgoing) are released. If invoked on <constant>NULL</constant> bus
|
|
object or when the bus connection is already closed this function executes no operation. This
|
|
call does not free or unreference the bus object itself. Use
|
|
<citerefentry><refentrytitle>sd_bus_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
for that.</para>
|
|
|
|
<para><function>sd_bus_flush()</function> synchronously writes out all outgoing queued message
|
|
on a bus connection if there are any. This function call may block if the peer is not processing
|
|
bus messages quickly.</para>
|
|
|
|
<para>Before a program exits it is usually a good idea to flush any pending messages with
|
|
<function>sd_bus_flush()</function> and then close connections with
|
|
<function>sd_bus_close()</function> to ensure that no unwritten messages are lost, no further
|
|
messages may be queued and all incoming but unprocessed messages are released. After both
|
|
operations have been done, it is a good idea to also drop any remaining references to the bus
|
|
object so that it may be freed. Since these three operations are frequently done together a
|
|
helper call
|
|
<citerefentry><refentrytitle>sd_bus_flush_close_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
is provided that combines them into one.</para>
|
|
|
|
<para><function>sd_bus_default_flush_close()</function> is similar to
|
|
<function>sd_bus_flush_close_unref()</function>, but does not take a bus pointer argument and
|
|
instead iterates over any of the "default" buses opened by
|
|
<citerefentry><refentrytitle>sd_bus_default</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_bus_default_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_bus_default_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
and similar calls. <function>sd_bus_default_flush_close()</function> is particularly useful to
|
|
clean up any buses opened using those calls before the program exits.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Return Value</title>
|
|
|
|
<para>On success, <function>sd_bus_flush()</function> returns a non-negative integer. On
|
|
failure, it returns a negative errno-style error code.</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_close()</function> and
|
|
<function>sd_bus_flush()</function> were added in version 221.</para>
|
|
<para><function>sd_bus_default_flush_close()</function> was added in version 227.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>See Also</title>
|
|
|
|
<para><simplelist type="inline">
|
|
<member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_bus_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_bus_set_close_on_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
</simplelist></para>
|
|
</refsect1>
|
|
|
|
</refentry>
|