1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
<?xml version='1.0'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1+ -->
<refentry id="sd_event_source_set_userdata" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_event_source_set_userdata</title>
<productname>elogind</productname>
</refentryinfo>
<refmeta>
<refentrytitle>sd_event_source_set_userdata</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_event_source_set_userdata</refname>
<refname>sd_event_source_get_userdata</refname>
<refpurpose>Set or retrieve user data pointer of event sources</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include <elogind/sd-event.h></funcsynopsisinfo>
<funcprototype>
<funcdef>void* <function>sd_event_source_set_userdata</function></funcdef>
<paramdef>sd_event_source *<parameter>source</parameter></paramdef>
<paramdef>void *<parameter>userdata</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>void* <function>sd_event_source_get_userdata</function></funcdef>
<paramdef>sd_event_source *<parameter>source</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_event_source_set_userdata()</function> may be
used to set an arbitrary user data pointer for the event source
object specified as <parameter>source</parameter>. The user data
pointer is usually specified when creating an event source object
with calls such as
<citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>
or
<citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
and may be updated with this call. The user data pointer is also
passed to all handler callback functions associated with the event
source. The <parameter>userdata</parameter> parameter specifies
the new user data pointer to set, the function returns the
previous user data pointer. Note that <constant>NULL</constant> is
a valid user data pointer.</para>
<para><function>sd_event_source_get_userdata()</function> may be
used to query the current user data pointer assigned to the event
source object <parameter>source</parameter>.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success,
<function>sd_event_source_set_userdata()</function> and
<function>sd_event_source_get_userdata()</function> return the
previously set user data pointer. On failure, they return
NULL.</para>
</refsect1>
<xi:include href="libelogind-pkgconfig.xml" />
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_add_inotify</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_source_set_description</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
|
