man/sd_event_exit.xml

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   6   SPDX-License-Identifier: LGPL-2.1+
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   8
   9 <refentry id="sd_event_exit" xmlns:xi="http://www.w3.org/2001/XInclude">
  10
  11   <refentryinfo>
  12     <title>sd_event_exit</title>
  13     <productname>systemd</productname>
  14   </refentryinfo>
  15
  16   <refmeta>
  17     <refentrytitle>sd_event_exit</refentrytitle>
  18     <manvolnum>3</manvolnum>
  19   </refmeta>
  20
  21   <refnamediv>
  22     <refname>sd_event_exit</refname>
  23     <refname>sd_event_get_exit_code</refname>
  24
  25     <refpurpose>Ask the event loop to exit</refpurpose>
  26   </refnamediv>
  27
  28   <refsynopsisdiv>
  29     <funcsynopsis>
  30       <funcsynopsisinfo>#include &lt;systemd/sd-event.h&gt;</funcsynopsisinfo>
  31
  32       <funcprototype>
  33         <funcdef>int <function>sd_event_exit</function></funcdef>
  34         <paramdef>sd_event *<parameter>event</parameter></paramdef>
  35         <paramdef>int <parameter>code</parameter></paramdef>
  36       </funcprototype>
  37
  38       <funcprototype>
  39         <funcdef>int <function>sd_event_get_exit_code</function></funcdef>
  40         <paramdef>sd_event *<parameter>event</parameter></paramdef>
  41         <paramdef>int *<parameter>code</parameter></paramdef>
  42       </funcprototype>
  43
  44     </funcsynopsis>
  45   </refsynopsisdiv>
  46
  47   <refsect1>
  48     <title>Description</title>
  49
  50     <para><function>sd_event_exit()</function> requests the event loop
  51     specified in the <parameter>event</parameter> event loop object to
  52     exit. The <parameter>code</parameter> parameter may be any integer
  53     value and is returned as-is by
  54     <citerefentry><refentrytitle>sd_event_loop</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  55     after the last event loop iteration. It may also be queried
  56     using <function>sd_event_get_exit_code()</function>, see
  57     below. </para>
  58
  59     <para>When exiting is requested the event loop will stop listening
  60     for and dispatching regular event sources. Instead it will proceed
  61     with executing only event sources registered with
  62     <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  63     in the order defined by their priority. After all exit event
  64     sources have been dispatched the event loop is terminated.</para>
  65
  66     <para>If <function>sd_event_exit()</function> is invoked a second
  67     time while the event loop is still processing exit event sources,
  68     the exit code stored in the event loop object is updated, but
  69     otherwise no further operation is executed.</para>
  70
  71     <para><function>sd_event_get_exit_code()</function> may be used to
  72     query the exit code passed into
  73     <function>sd_event_exit()</function> earlier.</para>
  74
  75     <para>While the full positive and negative integer ranges may be used
  76     for the exit code, care should be taken not pick exit codes that
  77     conflict with regular exit codes returned by
  78     <function>sd_event_loop()</function>, if these exit codes shall be
  79     distinguishable.</para>
  80   </refsect1>
  81
  82   <refsect1>
  83     <title>Return Value</title>
  84
  85     <para>On success, <function>sd_event_exit()</function> and
  86     <function>sd_event_get_exit_code()</function> return 0 or a positive
  87     integer. On failure, they return a negative errno-style error
  88     code.</para>
  89   </refsect1>
  90
  91   <refsect1>
  92     <title>Errors</title>
  93
  94     <para>Returned errors may indicate the following problems:</para>
  95
  96     <variablelist>
  97
  98       <varlistentry>
  99         <term><constant>-EINVAL</constant></term>
 100
 101         <listitem><para>The event loop object or error code pointer are invalid.</para></listitem>
 102
 103       </varlistentry>
 104
 105       <varlistentry>
 106         <term><constant>-ECHILD</constant></term>
 107
 108         <listitem><para>The event loop was created in a different process.</para></listitem>
 109       </varlistentry>
 110
 111       <varlistentry>
 112         <term><constant>-ESTALE</constant></term>
 113
 114         <listitem><para>The event loop has exited already and all exit handlers are already processed.</para></listitem>
 115       </varlistentry>
 116
 117       <varlistentry>
 118         <term><constant>-ENODATA</constant></term>
 119
 120         <listitem><para>The event loop has not been requested to exit yet.</para></listitem>
 121       </varlistentry>
 122
 123     </variablelist>
 124   </refsect1>
 125
 126   <xi:include href="libsystemd-pkgconfig.xml" />
 127
 128   <refsect1>
 129     <title>See Also</title>
 130
 131     <para>
 132       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 133       <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 134       <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 135       <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 136     </para>
 137   </refsect1>
 138
 139 </refentry>