man/sd_bus_process.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   4
   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   This file is part of systemd.
   9
  10   Copyright 2016 Julian Orth
  11 -->
  12
  13 <refentry id="sd_bus_process">
  14
  15   <refentryinfo>
  16     <title>sd_bus_process</title>
  17     <productname>systemd</productname>
  18
  19     <authorgroup>
  20       <author>
  21         <firstname>Julian</firstname>
  22         <surname>Orth</surname>
  23         <email>ju.orth@gmail.com</email>
  24       </author>
  25     </authorgroup>
  26   </refentryinfo>
  27
  28   <refmeta>
  29     <refentrytitle>sd_bus_process</refentrytitle>
  30     <manvolnum>3</manvolnum>
  31   </refmeta>
  32
  33   <refnamediv>
  34     <refname>sd_bus_process</refname>
  35
  36     <refpurpose>Drive the connection</refpurpose>
  37   </refnamediv>
  38
  39   <refsynopsisdiv>
  40     <funcsynopsis>
  41       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  42
  43       <funcprototype>
  44         <funcdef>int <function>sd_bus_process</function></funcdef>
  45         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  46         <paramdef>sd_bus_message **<parameter>r</parameter></paramdef>
  47       </funcprototype>
  48     </funcsynopsis>
  49   </refsynopsisdiv>
  50
  51   <refsect1>
  52     <title>Description</title>
  53
  54     <para>
  55       <function>sd_bus_process()</function> drives the connection between the
  56       message bus and the client. That is, it handles connecting,
  57       authentication, and message processing. It should be called in a loop
  58       until no further progress can be made or an error occurs.
  59     </para>
  60
  61     <para>
  62       Once no further progress can be made,
  63       <citerefentry><refentrytitle>sd_bus_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  64       should be called. Alternatively the user can wait for incoming data on
  65       the file descriptor returned by
  66       <citerefentry><refentrytitle>sd_bus_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
  67     </para>
  68
  69     <para>
  70       <function>sd_bus_process</function> processes at most one incoming
  71       message per call.  If the parameter <parameter>r</parameter> is not NULL
  72       and the call processed a message, <code>*r</code> is set to this message.
  73       The caller owns a reference to this message and should call
  74       <citerefentry><refentrytitle>sd_bus_message_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  75       when the message is no longer needed. If <parameter>r</parameter> is not
  76       NULL, progress was made, but no message was processed, <code>*r</code> is
  77       set to NULL.
  78     </para>
  79   </refsect1>
  80
  81   <refsect1>
  82     <title>Return Value</title>
  83
  84     <para>
  85       If progress was made, a positive integer is returned. If no progress was
  86       made, 0 is returned. If an error occurs, a negative errno-style error code
  87       is returned.
  88     </para>
  89   </refsect1>
  90
  91   <refsect1>
  92     <title>See Also</title>
  93
  94     <para>
  95       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
  96       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  97     </para>
  98   </refsect1>
  99
 100 </refentry>