1 <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 This file is part of elogind.
8 Copyright 2015 Lennart Poettering
10 elogind is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
12 the Free Software Foundation; either version 2.1 of the License, or
13 (at your option) any later version.
15 elogind is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public License
21 along with elogind; If not, see <http://www.gnu.org/licenses/>.
24 <refentry id="sd_event_source_unref" xmlns:xi="http://www.w3.org/2001/XInclude">
27 <title>sd_event_source_unref</title>
28 <productname>elogind</productname>
32 <contrib>Developer</contrib>
33 <firstname>Lennart</firstname>
34 <surname>Poettering</surname>
35 <email>lennart@poettering.net</email>
41 <refentrytitle>sd_event_source_unref</refentrytitle>
42 <manvolnum>3</manvolnum>
46 <refname>sd_event_source_unref</refname>
47 <refname>sd_event_source_ref</refname>
49 <refpurpose>Increase or decrease event source reference counters</refpurpose>
54 <funcsynopsisinfo>#include <elogind/sd-event.h></funcsynopsisinfo>
57 <funcdef>sd_event_source* <function>sd_event_source_unref</function></funcdef>
58 <paramdef>sd_event_source *<parameter>source</parameter></paramdef>
62 <funcdef>sd_event_source* <function>sd_event_source_ref</function></funcdef>
63 <paramdef>sd_event_source *<parameter>source</parameter></paramdef>
70 <title>Description</title>
72 <para><function>sd_event_source_unref()</function> may be used to
73 decrement by one the reference counter of the event source object
74 specified as <parameter>source</parameter>. The reference counter
75 is initially set to one, when the event source is created with calls
77 <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>
79 <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>. When
80 the reference counter reaches zero it is removed from its event loop
81 object and destroyed.</para>
83 <para><function>sd_event_source_ref()</function> may be used
84 to increase by one the reference counter of the event source object
85 specified as <parameter>source</parameter>.</para>
87 <para>Both functions execute no operation if the passed event
88 source object is <constant>NULL</constant>.</para>
90 <para>Note that event source objects stay alive and may be
91 dispatched as long as they have a reference counter greater than
92 zero. In order to drop a reference of an event source and make
93 sure the associated event source handler function is not called
94 anymore it is recommended to combine a call of
95 <function>sd_event_source_unref()</function> with a prior call to
96 <function>sd_event_source_set_enabled()</function> with
97 <constant>SD_EVENT_OFF</constant>.</para>
101 <title>Return Value</title>
103 <para><function>sd_event_source_unref()</function> always returns
104 <constant>NULL</constant>.
105 <function>sd_event_source_ref()</function> always returns the
106 event source object passed in.</para>
109 <xi:include href="libelogind-pkgconfig.xml" />
112 <title>See Also</title>
115 <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
116 <citerefentry><refentrytitle>sd_event_add_io</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
117 <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
118 <citerefentry><refentrytitle>sd_event_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
119 <citerefentry><refentrytitle>sd_event_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
120 <citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
121 <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>