systemd/man/sd_event_source_set_userdata.xml
Zbigniew Jędrzejewski-Szmek 11a1589223 tree-wide: drop license boilerplate
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.

I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
2018-04-06 18:58:55 +02:00

109 lines
4.0 KiB
XML

<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
SPDX-License-Identifier: LGPL-2.1+
This file is part of systemd.
Copyright 2015 Lennart Poettering
-->
<refentry id="sd_event_source_set_userdata" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_event_source_set_userdata</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Lennart</firstname>
<surname>Poettering</surname>
<email>lennart@poettering.net</email>
</author>
</authorgroup>
</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 &lt;systemd/sd-event.h&gt;</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="libsystemd-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_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_add_signal</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>