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-or-later -->
5
6<refentry id="sd_bus_get_current_handler" xmlns:xi="http://www.w3.org/2001/XInclude">
7
8  <refentryinfo>
9    <title>sd_bus_get_current_handler</title>
10    <productname>systemd</productname>
11  </refentryinfo>
12
13  <refmeta>
14    <refentrytitle>sd_bus_get_current_handler</refentrytitle>
15    <manvolnum>3</manvolnum>
16  </refmeta>
17
18  <refnamediv>
19    <refname>sd_bus_get_current_handler</refname>
20    <refname>sd_bus_get_current_message</refname>
21    <refname>sd_bus_get_current_slot</refname>
22    <refname>sd_bus_get_current_userdata</refname>
23
24    <refpurpose>Query information of the callback a bus object is currently running</refpurpose>
25  </refnamediv>
26
27  <refsynopsisdiv>
28    <funcsynopsis>
29      <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
30
31      <xi:include href="sd_bus_add_match.xml" xpointer="sd_bus_message_handler_t"/>
32
33      <funcprototype>
34        <funcdef>sd_bus_message_handler_t <function>sd_bus_get_current_handler</function></funcdef>
35        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
36      </funcprototype>
37
38      <funcprototype>
39        <funcdef>sd_bus_message* <function>sd_bus_get_current_message</function></funcdef>
40        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
41      </funcprototype>
42
43      <funcprototype>
44        <funcdef>sd_bus_slot* <function>sd_bus_get_current_slot</function></funcdef>
45        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
46      </funcprototype>
47
48      <funcprototype>
49        <funcdef>void* <function>sd_bus_get_current_userdata</function></funcdef>
50        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
51      </funcprototype>
52    </funcsynopsis>
53  </refsynopsisdiv>
54
55  <refsect1>
56    <title>Description</title>
57
58    <para>Whenever sd-bus is about to invoke a user-supplied callback function, it stores the
59    current callback, D-Bus message, slot and userdata pointer and allows these to be queried via
60    <function>sd_bus_get_current_handler()</function>,
61    <function>sd_bus_get_current_message()</function>,
62    <function>sd_bus_get_current_slot()</function> and
63    <function>sd_bus_get_current_userdata()</function>, respectively. If <parameter>bus</parameter>
64    cannot be resolved or if execution does not reside in a user-supplied callback of
65    <parameter>bus</parameter>, these functions return <constant>NULL</constant>.</para>
66  </refsect1>
67
68  <refsect1>
69    <title>Return Value</title>
70
71    <para>On success, these functions return the requested object. On failure, they return
72    <constant>NULL</constant>.</para>
73  </refsect1>
74
75  <xi:include href="libsystemd-pkgconfig.xml" />
76
77  <refsect1>
78    <title>See Also</title>
79
80    <para>
81      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
82      <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>
83    </para>
84  </refsect1>
85
86</refentry>
87