man/sd_event_exit.xml

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  23
  24 <refentry id="sd_event_exit" xmlns:xi="http://www.w3.org/2001/XInclude">
  25
  26   <refentryinfo>
  27     <title>sd_event_exit</title>
  28     <productname>systemd</productname>
  29
  30     <authorgroup>
  31       <author>
  32         <contrib>Developer</contrib>
  33         <firstname>Lennart</firstname>
  34         <surname>Poettering</surname>
  35         <email>lennart@poettering.net</email>
  36       </author>
  37     </authorgroup>
  38   </refentryinfo>
  39
  40   <refmeta>
  41     <refentrytitle>sd_event_exit</refentrytitle>
  42     <manvolnum>3</manvolnum>
  43   </refmeta>
  44
  45   <refnamediv>
  46     <refname>sd_event_exit</refname>
  47     <refname>sd_event_get_exit_code</refname>
  48
  49     <refpurpose>Ask the event loop to exit</refpurpose>
  50   </refnamediv>
  51
  52   <refsynopsisdiv>
  53     <funcsynopsis>
  54       <funcsynopsisinfo>#include &lt;systemd/sd-event.h&gt;</funcsynopsisinfo>
  55
  56       <funcprototype>
  57         <funcdef>int <function>sd_event_exit</function></funcdef>
  58         <paramdef>sd_event *<parameter>event</parameter></paramdef>
  59         <paramdef>int <parameter>code</parameter></paramdef>
  60       </funcprototype>
  61
  62       <funcprototype>
  63         <funcdef>int <function>sd_event_get_exit_code</function></funcdef>
  64         <paramdef>sd_event *<parameter>event</parameter></paramdef>
  65         <paramdef>int *<parameter>code</parameter></paramdef>
  66       </funcprototype>
  67
  68     </funcsynopsis>
  69   </refsynopsisdiv>
  70
  71   <refsect1>
  72     <title>Description</title>
  73
  74     <para><function>sd_event_exit()</function> requests the event loop
  75     specified in the <parameter>event</parameter> event loop object to
  76     exit. The <parameter>code</parameter> parameter may be any integer
  77     value and is returned as-is by
  78     <citerefentry><refentrytitle>sd_event_loop</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  79     after the last event loop iteration. It may also be queried
  80     using <function>sd_event_get_exit_code()</function>, see
  81     below. </para>
  82
  83     <para>When exiting is requested the event loop will stop listening
  84     for and dispatching regular event sources. Instead it will proceed
  85     with executing only event sources registered with
  86     <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  87     in the order defined by their priority. After all exit event
  88     sources have been dispatched the event loop is terminated.</para>
  89
  90     <para>If <function>sd_event_exit()</function> is invoked a second
  91     time while the event loop is still processing exit event sources,
  92     the exit code stored in the event loop object is updated, but
  93     otherwise no further operation is executed.</para>
  94
  95     <para><function>sd_event_get_exit_code()</function> may be used to
  96     query the exit code passed into
  97     <function>sd_event_exit()</function> earlier.</para>
  98
  99     <para>While the full positive and negative integer ranges may be used
 100     for the exit code, care should be taken not pick exit codes that
 101     conflict with regular exit codes returned by
 102     <function>sd_event_loop()</function>, if these exit codes shall be
 103     distinguishable.</para>
 104   </refsect1>
 105
 106   <refsect1>
 107     <title>Return Value</title>
 108
 109     <para>On success, <function>sd_event_exit()</function> and
 110     <function>sd_event_get_exit_code()</function> return 0 or a positive
 111     integer. On failure, they return a negative errno-style error
 112     code.</para>
 113   </refsect1>
 114
 115   <refsect1>
 116     <title>Errors</title>
 117
 118     <para>Returned errors may indicate the following problems:</para>
 119
 120     <variablelist>
 121
 122       <varlistentry>
 123         <term><constant>-EINVAL</constant></term>
 124
 125         <listitem><para>The event loop object or error code pointer are invalid.</para></listitem>
 126
 127       </varlistentry>
 128
 129       <varlistentry>
 130         <term><constant>-ECHILD</constant></term>
 131
 132         <listitem><para>The event loop was created in a different process.</para></listitem>
 133       </varlistentry>
 134
 135       <varlistentry>
 136         <term><constant>-ESTALE</constant></term>
 137
 138         <listitem><para>The event loop has exited already and all exit handlers are already processed.</para></listitem>
 139       </varlistentry>
 140
 141       <varlistentry>
 142         <term><constant>-ENODATA</constant></term>
 143
 144         <listitem><para>The event loop has not been requested to exit yet.</para></listitem>
 145       </varlistentry>
 146
 147     </variablelist>
 148   </refsect1>
 149
 150   <xi:include href="libsystemd-pkgconfig.xml" />
 151
 152   <refsect1>
 153     <title>See Also</title>
 154
 155     <para>
 156       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 157       <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 158       <citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 159       <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 160     </para>
 161   </refsect1>
 162
 163 </refentry>