-<?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">
-
-<!--
- This file is part of systemd.
-
- Copyright 2014 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
--->
+<?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_new" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_event_new</title>
<productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Lennart</firstname>
- <surname>Poettering</surname>
- <email>lennart@poettering.net</email>
- </author>
- </authorgroup>
</refentryinfo>
<refmeta>
<refname>sd_event_default</refname>
<refname>sd_event_ref</refname>
<refname>sd_event_unref</refname>
+ <refname>sd_event_unrefp</refname>
<refname>sd_event_get_tid</refname>
<refname>sd_event</refname>
<paramdef>sd_event *<parameter>event</parameter></paramdef>
</funcprototype>
+ <funcprototype>
+ <funcdef>void <function>sd_event_unrefp</function></funcdef>
+ <paramdef>sd_event **<parameter>event</parameter></paramdef>
+ </funcprototype>
+
<funcprototype>
<funcdef>int <function>sd_event_get_tid</function></funcdef>
<paramdef>sd_event *<parameter>event</parameter></paramdef>
<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>
- or
+ <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_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry> or
+ <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
and then execute the event loop using
- <citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
+ <citerefentry><refentrytitle>sd_event_loop</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
<para><function>sd_event_ref()</function> increases the reference
count of the specified event loop object by one.</para>
all remaining event sources of the event loop also need to be
freed as each keeps a reference to it.</para>
- <para>Both <function>sd_event_ref()</function> and
- <function>sd_event_unref()</function> execute no operation if the
+ <para><function>sd_event_unrefp()</function> is similar to
+ <function>sd_event_unref()</function> but takes a pointer to a
+ pointer to an <type>sd_event</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. Use a declaration like the following,
+ in order to allocate an event loop object that is freed
+ automatically as the code block is left:</para>
+
+ <programlisting>{
+ __attribute__((cleanup(sd_event_unrefp))) sd_event *event = NULL;
+ int r;
+ …
+ r = sd_event_default(&event);
+ if (r < 0)
+ fprintf(stderr, "Failed to allocate event loop: %s\n", strerror(-r));
+ …
+}</programlisting>
+
+ <para><function>sd_event_ref()</function>,
+ <function>sd_event_unref()</function> and
+ <function>sd_event_unrefp()</function> execute no operation if the
passed in event loop object is <constant>NULL</constant>.</para>
<para><function>sd_event_get_tid()</function> retrieves the thread
<refsect1>
<title>Return Value</title>
- <para>On success, <function>sd_event_new()</function> and
- <function>sd_event_default()</function> return 0 or a positive
- integer. On failure, they return a negative errno-style error
- code. <function>sd_event_ref()</function> always returns a pointer
- to the event loop object passed
- in. <function>sd_event_unref()</function> always returns
+ <para>On success, <function>sd_event_new()</function>, <function>sd_event_default()</function> and
+ <function>sd_event_get_tid()</function> return 0 or a positive integer. On failure, they return a
+ negative errno-style error code. <function>sd_event_ref()</function> always returns a pointer to the
+ event loop object passed in. <function>sd_event_unref()</function> always returns
<constant>NULL</constant>.</para>
- </refsect1>
- <refsect1>
- <title>Errors</title>
+ <refsect2>
+ <title>Errors</title>
- <para>Returned errors may indicate the following problems:</para>
+
<para>Returned errors may indicate the following problems:</para>
- <variablelist>
- <varlistentry>
- <term><constant>-ENOMEM</constant></term>
+ <variablelist>
+ <varlistentry>
+ <term><constant>-ENOMEM</constant></term>
- <listitem><para>Not enough memory to allocate the object.</para></listitem>
- </varlistentry>
+
<listitem><para>Not enough memory to allocate the object.</para></listitem>
+ </varlistentry>
- <varlistentry>
- <term><constant>-EMFILE</constant></term>
+ <varlistentry>
+ <term><constant>-EMFILE</constant></term>
- <listitem><para>The maximum number of event loops has been allocated.</para></listitem>
+
<listitem><para>The maximum number of event loops has been allocated.</para></listitem>
- </varlistentry>
+ </varlistentry>
- <varlistentry>
- <term><constant>-ENXIO</constant></term>
+ <varlistentry>
+ <term><constant>-ENXIO</constant></term>
- <listitem><para><function>sd_event_get_tid()</function> was
- invoked on an event loop object that was not allocated with
- <function>sd_event_default()</function>.</para></listitem>
- </varlistentry>
+ <listitem><para><function>sd_event_get_tid()</function> was invoked on an event loop object that
+ was not allocated with <function>sd_event_default()</function>.</para></listitem>
+ </varlistentry>
- </variablelist>
+ </variablelist>
+ </refsect2>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
<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_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry project='man-pages'><refentrytitle>gettid</refentrytitle><manvolnum>2</manvolnum></citerefentry>
</para>
projects / thirdparty / systemd.git / blobdiff