mirror of
https://github.com/systemd/systemd.git
synced 2024-11-01 00:51:24 +03:00
120 lines
5.3 KiB
XML
120 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/4.2/docbookx.dtd">
|
|
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
|
|
|
|
<refentry id="sd_bus_attach_event"
|
|
xmlns:xi="http://www.w3.org/2001/XInclude">
|
|
|
|
<refentryinfo>
|
|
<title>sd_bus_attach_event</title>
|
|
<productname>systemd</productname>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>sd_bus_attach_event</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>sd_bus_attach_event</refname>
|
|
<refname>sd_bus_detach_event</refname>
|
|
<refname>sd_bus_get_event</refname>
|
|
|
|
<refpurpose>Attach a bus connection object to an event loop</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_bus_attach_event</function></funcdef>
|
|
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
|
<paramdef>sd_event *<parameter>e</parameter></paramdef>
|
|
<paramdef>int <parameter>priority</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_bus_detach_event</function></funcdef>
|
|
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>sd_event *<function>sd_bus_get_event</function></funcdef>
|
|
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
|
</funcprototype>
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para><function>sd_bus_attach_event()</function> attaches the specified bus connection object to an
|
|
<citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry> event loop object at
|
|
the specified priority (see
|
|
<citerefentry><refentrytitle>sd_event_source_set_priority</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
for details on event loop priorities). When a bus connection object is attached to an event loop incoming messages
|
|
will be automatically read and processed, and outgoing messages written, whenever the event loop is run. When the
|
|
event loop is about to terminate, the bus connection is automatically flushed and closed (see
|
|
<citerefentry><refentrytitle>sd_bus_set_close_on_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry> for
|
|
details on this). By default bus connection objects are not attached to any event loop. When a bus connection
|
|
object is attached to one it is not necessary to invoke
|
|
<citerefentry><refentrytitle>sd_bus_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry> or
|
|
<citerefentry><refentrytitle>sd_bus_process</refentrytitle><manvolnum>3</manvolnum></citerefentry> as this
|
|
functionality is handled automatically by the event loop.</para>
|
|
|
|
<para><function>sd_bus_detach_event()</function> detaches a bus object from its event loop.</para>
|
|
|
|
<para>The <function>sd_bus_get_event()</function> returns the event loop object the specified bus object is
|
|
currently attached to, or <constant>NULL</constant> if it is currently not attached to any.</para>
|
|
|
|
<para>Note that <function>sd_bus_attach_event()</function> is only one of three supported ways to implement I/O
|
|
event handling for bus connections. Alternatively use
|
|
<citerefentry><refentrytitle>sd_bus_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry> for hooking up a
|
|
bus connection object with external or manual event loops. Or use
|
|
<citerefentry><refentrytitle>sd_bus_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry> as a simple
|
|
synchronous, blocking I/O waiting call.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Return Value</title>
|
|
|
|
<para>On success, <function>sd_bus_attach_event()</function> and <function>sd_bus_detach_event()</function> return
|
|
0 or a positive integer. On failure, they return a negative errno-style error code.</para>
|
|
|
|
<para><function>sd_bus_get_event()</function> returns an event loop object or <constant>NULL</constant>.</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.</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect2>
|
|
</refsect1>
|
|
|
|
<xi:include href="libsystemd-pkgconfig.xml" />
|
|
|
|
<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-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_event_source_set_priority</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_bus_set_close_on_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_bus_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_bus_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|