man/sd_event_exit.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>