systemd/man/sd_event_source_unref.xml
Lennart Poettering 0c69794138 tree-wide: remove Lennart's copyright lines
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
2018-06-14 10:20:20 +02:00

128 lines
5.0 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+
-->
<refentry id="sd_event_source_unref" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_event_source_unref</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_unref</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_event_source_unref</refname>
<refname>sd_event_source_unrefp</refname>
<refname>sd_event_source_ref</refname>
<refpurpose>Increase or decrease event source reference counters</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;systemd/sd-event.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>sd_event_source* <function>sd_event_source_unref</function></funcdef>
<paramdef>sd_event_source *<parameter>source</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>void <function>sd_event_source_unrefp</function></funcdef>
<paramdef>sd_event_source **<parameter>source</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>sd_event_source* <function>sd_event_source_ref</function></funcdef>
<paramdef>sd_event_source *<parameter>source</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_event_source_unref()</function> may be used to
decrement by one the reference counter of the event source object
specified as <parameter>source</parameter>. The reference counter
is initially set to one, when the event source is created 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>. When
the reference counter reaches zero it is removed from its event loop
object and destroyed.</para>
<para><function>sd_event_source_unrefp()</function> is similar to
<function>sd_event_source_unref()</function> but takes a pointer to a
pointer to an <type>sd_event_source</type> object. This call is useful in
conjunction with GCC's and LLVM's <ulink
url="https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html">Clean-up
Variable Attribute</ulink>. Note that this function is defined as
inline function.</para>
<para><function>sd_event_source_ref()</function> may be used
to increase by one the reference counter of the event source object
specified as <parameter>source</parameter>.</para>
<para><function>sd_event_source_unref()</function>,
<function>sd_bus_creds_unrefp()</function> and
<function>sd_bus_creds_ref()</function> execute no operation if
the passed event source object is
<constant>NULL</constant>.</para>
<para>Note that event source objects stay alive and may be
dispatched as long as they have a reference counter greater than
zero. In order to drop a reference of an event source and make
sure the associated event source handler function is not called
anymore it is recommended to combine a call of
<function>sd_event_source_unref()</function> with a prior call to
<function>sd_event_source_set_enabled()</function> with
<constant>SD_EVENT_OFF</constant>.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para><function>sd_event_source_unref()</function> always returns
<constant>NULL</constant>.
<function>sd_event_source_ref()</function> always returns the
event source object passed in.</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_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>