systemd/man/sd_event_exit.xml
2015-12-26 20:37:17 +01:00

164 lines
5.6 KiB
XML

<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
This file is part of systemd.
Copyright 2015 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refentry id="sd_event_exit" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_event_exit</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_event_exit</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_event_exit</refname>
<refname>sd_event_get_exit_code</refname>
<refpurpose>Ask the event loop to exit</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;systemd/sd-event.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_event_exit</function></funcdef>
<paramdef>sd_event *<parameter>event</parameter></paramdef>
<paramdef>int <parameter>code</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_event_get_exit_code</function></funcdef>
<paramdef>sd_event *<parameter>event</parameter></paramdef>
<paramdef>int *<parameter>code</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_event_exit()</function> requests the event loop
specified in the <parameter>event</parameter> event loop object to
exit. The <parameter>code</parameter> parameter may be any integer
value and is returned as-is by
<citerefentry><refentrytitle>sd_event_loop</refentrytitle><manvolnum>3</manvolnum></citerefentry>
after the last event loop iteration. It may also be queried
using <function>sd_event_get_exit_code()</function>, see
below. </para>
<para>When exiting is requested the event loop will stop listening
for and dispatching regular event sources. Instead it will proceed
with executing only event sources registered with
<citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>
in the order defined by their priority. After all exit event
sources have been dispatched the event loop is terminated.</para>
<para>If <function>sd_event_exit()</function> is invoked a second
time while the event loop is still processing exit event sources,
the exit code stored in the event loop object is updated, but
otherwise no further operation is executed.</para>
<para><function>sd_event_get_exit_code()</function> may be used to
query the exit code passed into
<function>sd_event_exit()</function> earlier.</para>
<para>While the full positive and negative integer ranges may be used
for the exit code, care should be taken not pick exit codes that
conflict with regular exit codes returned by
<function>sd_event_loop()</function>, if these exit codes shall be
distinguishable.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success, <function>sd_event_exit()</function> and
<function>sd_event_get_exit_code()</function> 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>-EINVAL</constant></term>
<listitem><para>The event loop object or error code pointer are invalid.</para></listitem>
</varlistentry>
<varlistentry>
<term><constant>-ECHILD</constant></term>
<listitem><para>The event loop was created in a different process.</para></listitem>
</varlistentry>
<varlistentry>
<term><constant>-ESTALE</constant></term>
<listitem><para>The event loop has exited already and all exit handlers are already processed.</para></listitem>
</varlistentry>
<varlistentry>
<term><constant>-ENODATA</constant></term>
<listitem><para>The event loop has not been requested to exit yet.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>