+++ /dev/null
-<?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/>.
--->
-
-<refentry id="sd_event_new" conditional="ENABLE_KDBUS">
-
- <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>
- <refentrytitle>sd_event_new</refentrytitle>
- <manvolnum>3</manvolnum>
- </refmeta>
-
- <refnamediv>
- <refname>sd_event_new</refname>
- <refname>sd_event_default</refname>
- <refname>sd_event_ref</refname>
- <refname>sd_event_unref</refname>
-
- <refpurpose>Acquire and release an event loop object</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <funcsynopsis>
- <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
-
- <funcprototype>
- <funcdef>int <function>sd_event_new</function></funcdef>
- <paramdef>sd_bus **<parameter>event</parameter></paramdef>
- </funcprototype>
-
- <funcprototype>
- <funcdef>int <function>sd_event_default</function></funcdef>
- <paramdef>sd_bus **<parameter>event</parameter></paramdef>
- </funcprototype>
-
- <funcprototype>
- <funcdef>sd_bus *<function>sd_event_ref</function></funcdef>
- <paramdef>sd_bus *<parameter>event</parameter></paramdef>
- </funcprototype>
-
- <funcprototype>
- <funcdef>sd_bus *<function>sd_event_unref</function></funcdef>
- <paramdef>sd_bus *<parameter>event</parameter></paramdef>
- </funcprototype>
-
- </funcsynopsis>
- </refsynopsisdiv>
-
- <refsect1>
- <title>Description</title>
-
- <para><function>sd_event_new()</function> allocates a new event
- loop object. The event loop object is returned in the
- <parameter>event</parameter> parameter. After use, drop
- the returned reference with
- <function>sd_event_unref()</function>. When the last reference is
- dropped, the object is freed.</para>
-
- <para><function>sd_event_default()</function> acquires a reference
- to the default event loop object of the calling thread, possibly
- allocating a new object if no default event loop object has been
- allocated yet for the thread. After use, drop the returned
- reference with <function>sd_event_unref()</function>. When the
- last reference is dropped, the event loop is freed. If this
- function is called while the object returned from a previous call
- from the same thread is still referenced, the same object is
- returned again, but the reference is increased by one. It is
- recommended to use this call instead of
- <function>sd_event_new()</function> in order to share event loop
- objects between various components that are dispatched in the same
- thread. All threads have exactly either zero or one default event loop
- objects associated, but never more.</para>
-
- <para><function>sd_event_ref()</function> increases the reference
- count of the specified event loop object by one.</para>
-
- <para><function>sd_event_unref()</function> decreases the
- reference count of the specified event loop object by one. If
- the count hits zero, the object is freed. Note that it
- is freed regardless of whether it is the default event loop object for a
- thread or not. This means that allocating an event loop with
- <function>sd_event_default()</function>, then releasing it, and
- then acquiring a new one with
- <function>sd_event_default()</function> will result in two
- distinct objects. Note that in order to free an event loop object,
- all remaining event sources of the event loop also need to be
- freed as each keeps a reference to it.</para>
- </refsect1>
-
- <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
- <constant>NULL</constant>.</para>
- </refsect1>
-
- <refsect1>
- <title>Errors</title>
-
- <para>Returned errors may indicate the following problems:</para>
-
- <variablelist>
- <varlistentry>
- <term><constant>-ENOMEM</constant></term>
-
- <listitem><para>Not enough memory to allocate the object.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><constant>-EMFILE</constant></term>
-
- <listitem><para>The maximum number of event loops has been allocated.</para></listitem>
-
- </varlistentry>
- </variablelist>
- </refsect1>
-
- <refsect1>
- <title>Notes</title>
-
- <para><function>sd_event_new()</function> and the other functions
- described here are available as a shared library, which can be
- compiled and linked to with the
- <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- file.</para>
- </refsect1>
-
- <refsect1>
- <title>See Also</title>
-
- <para>
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <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_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>
- </para>
- </refsect1>
-
-</refentry>
~ianmdlvl / elogind.git / blobdiff