man/sd_bus_set_close_on_exit.xml

   1 <?xml version='1.0'?>
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="sd_bus_set_close_on_exit"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>sd_bus_set_close_on_exit</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>sd_bus_set_close_on_exit</refentrytitle>
  16     <manvolnum>3</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>sd_bus_set_close_on_exit</refname>
  21     <refname>sd_bus_get_close_on_exit</refname>
  22
  23     <refpurpose>Control whether to close the bus connection during the event loop exit phase
  24     </refpurpose>
  25   </refnamediv>
  26
  27   <refsynopsisdiv>
  28     <funcsynopsis>
  29       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  30
  31       <funcprototype>
  32         <funcdef>int <function>sd_bus_set_close_on_exit</function></funcdef>
  33         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  34         <paramdef>int <parameter>b</parameter></paramdef>
  35       </funcprototype>
  36
  37       <funcprototype>
  38         <funcdef>int <function>sd_bus_get_close_on_exit</function></funcdef>
  39         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  40       </funcprototype>
  41
  42     </funcsynopsis>
  43   </refsynopsisdiv>
  44
  45   <refsect1>
  46     <title>Description</title>
  47
  48     <para><function>sd_bus_set_close_on_exit()</function> may be used to enable or disable whether
  49     the bus connection is automatically flushed (as in
  50     <citerefentry><refentrytitle>sd_bus_flush</refentrytitle><manvolnum>3</manvolnum></citerefentry>)
  51     and closed (as in
  52     <citerefentry><refentrytitle>sd_bus_close</refentrytitle><manvolnum>3</manvolnum></citerefentry>)
  53     during the exit phase of the event loop. This logic only applies to bus connections that are
  54     attached to an
  55     <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  56     event loop, see
  57     <citerefentry><refentrytitle>sd_bus_attach_event</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
  58     By default this mechanism is enabled and makes sure that any pending messages that have not been
  59     written to the bus connection are written out when the event loop is shutting down. In some
  60     cases this behaviour is not desirable, for example when the bus connection shall remain usable
  61     until after the event loop exited. If <parameter>b</parameter> is true, the feature is enabled
  62     (which is the default), otherwise disabled.</para>
  63
  64     <para><function>sd_bus_get_close_on_exit()</function> may be used to query the current setting
  65     of this feature. It returns zero when the feature is disabled, and positive if enabled.</para>
  66   </refsect1>
  67
  68   <refsect1>
  69     <title>Return Value</title>
  70
  71     <para>On success, <function>sd_bus_set_close_on_exit()</function> returns a non-negative
  72     integer. On failure, it returns a negative errno-style error code.</para>
  73
  74     <para><function>sd_bus_get_close_on_exit()</function> returns 0 if the feature is currently
  75     disabled or a positive integer if it is enabled. On failure, it returns a negative errno-style
  76     error code.</para>
  77
  78     <refsect2>
  79       <title>Errors</title>
  80
  81       <para>Returned errors may indicate the following problems:</para>
  82
  83       <variablelist>
  84         <varlistentry>
  85           <term><constant>-ECHILD</constant></term>
  86
  87           <listitem><para>The bus connection was created in a different process.</para>
  88           </listitem>
  89         </varlistentry>
  90       </variablelist>
  91     </refsect2>
  92   </refsect1>
  93
  94   <xi:include href="libsystemd-pkgconfig.xml" />
  95
  96   <refsect1>
  97     <title>See Also</title>
  98
  99     <para>
 100       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 101       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 102       <citerefentry><refentrytitle>sd_bus_flush</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 103       <citerefentry><refentrytitle>sd_bus_attach_event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 104       <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 105       <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 106     </para>
 107   </refsect1>
 108 </refentry>