mirror of
https://github.com/systemd/systemd.git
synced 2024-11-27 12:13:33 +08:00
157 lines
6.3 KiB
XML
157 lines
6.3 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_event_exit" xmlns:xi="http://www.w3.org/2001/XInclude">
|
|
|
|
<refentryinfo>
|
|
<title>sd_event_exit</title>
|
|
<productname>systemd</productname>
|
|
</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 <systemd/sd-event.h></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>
|
|
|
|
<para>Note that for most event source types passing the callback pointer as <constant>NULL</constant> in
|
|
the respective constructor call (i.e. in
|
|
<citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
…) has the effect of <function>sd_event_exit()</function> being invoked once the event source triggers,
|
|
with the specified userdata pointer cast to an integer as the exit code parameter. This is useful to
|
|
automatically terminate an event loop after some condition, such as a time-out or reception of
|
|
<constant>SIGTERM</constant> or similar. See the documentation for the respective constructor call for
|
|
details.</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>
|
|
|
|
<refsect2>
|
|
<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, library or module instance.</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>
|
|
</refsect2>
|
|
</refsect1>
|
|
|
|
<xi:include href="libsystemd-pkgconfig.xml" />
|
|
|
|
<refsect1>
|
|
<title>History</title>
|
|
<para><function>sd_event_exit()</function> and
|
|
<function>sd_event_get_exit_code()</function> were added in version 229.</para>
|
|
</refsect1>
|
|
|
|
<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>,
|
|
<citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_event_add_inotify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|