3be1d7e0c5bf60658d34eb6311d4e77c6803578cTom Gundersen<?xml version='1.0'?> <!--*-nxml-*-->

3be1d7e0c5bf60658d34eb6311d4e77c6803578cTom Gundersen<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"

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3be1d7e0c5bf60658d34eb6311d4e77c6803578cTom Gundersen

3be1d7e0c5bf60658d34eb6311d4e77c6803578cTom Gundersen

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen<refentry id="sd_event_new" conditional="ENABLE_KDBUS">

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen

3be1d7e0c5bf60658d34eb6311d4e77c6803578cTom Gundersen <refentryinfo>

3be1d7e0c5bf60658d34eb6311d4e77c6803578cTom Gundersen <title>sd_event_new</title>

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen <productname>systemd</productname>

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen <authorgroup>

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen <author>

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen <contrib>Developer</contrib>

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen <firstname>Lennart</firstname>

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen <surname>Poettering</surname>

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen <email>lennart@poettering.net</email>

f5f07dbf06f6df9d12e092c05ad8cfbe244d203fSusant Sahani </author>

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen </authorgroup>

aa9f11405829fd4755fef28602a7167dba3ddc89Tom Gundersen </refentryinfo>

3be1d7e0c5bf60658d34eb6311d4e77c6803578cTom Gundersen

3be1d7e0c5bf60658d34eb6311d4e77c6803578cTom Gundersen <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 &lt;systemd/sd-bus.h&gt;</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>