-<?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" [
-<!ENTITY % entities SYSTEM "custom-entities.ent" >
-%entities;
-]>
+<?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+ -->
-<!--
- This file is part of systemd.
-
- Copyright 2014 Zbigniew Jędrzejewski-Szmek
-
- 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_get_fd" conditional="ENABLE_KDBUS"
- xmlns:xi="http://www.w3.org/2001/XInclude">
+<refentry id="sd_event_get_fd" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_event_get_fd</title>
<productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>More text</contrib>
- <firstname>Zbigniew</firstname>
- <surname>Jędrzejewski-Szmek</surname>
- <email>zbyszek@in.waw.pl</email>
- </author>
- </authorgroup>
</refentryinfo>
<refmeta>
<refsynopsisdiv>
<funcsynopsis>
- <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
+ <funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_event_get_fd</function></funcdef>
- <paramdef>sd_
bus *<parameter>event</parameter></paramdef>
+ <paramdef>sd_
event *<parameter>event</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<title>Description</title>
<para><function>sd_event_get_fd()</function> returns the file
- descriptor that the event loop object returned by the
+ descriptor that an event loop object returned by the
<citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- function uses to wait for events. This file descriptor can be
- polled for events. This makes it possible to embed the
+ function uses to wait for events. This file descriptor may itself
+ be polled for
+ <constant>POLLIN</constant>/<constant>EPOLLIN</constant>
+ events. This makes it possible to embed an
<citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- event loop inside of another event loop.</para>
+ event loop into another, possibly foreign, event loop.</para>
+
+ <para>The returned file descriptor refers to an <citerefentry
+ project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ object. It is recommended not to alter it by invoking
+ <citerefentry
+ project='man-pages'><refentrytitle>epoll_ctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ on it, in order to avoid interference with the event loop's inner
+ logic and assumptions.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
- <para>On success, <function>sd_event_get_fd()</function> returns a
- non-negative integer. On failure, it returns a negative
- errno-style error code.</para>
- </refsect1>
+ <para>On success, <function>sd_event_get_fd()</function> returns a non-negative file descriptor. On
+ failure, it returns a negative errno-style error code.</para>
- <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>-EINVAL</constant></term>
+ <variablelist>
+ <varlistentry>
+ <term><constant>-EINVAL</constant></term>
- <listitem><para><parameter>event</parameter> is not a valid
- pointer to an <structname>sd_event</structname> structure.
- </para></listitem>
- </varlistentry>
+ <listitem><para><parameter>event</parameter> is not a valid pointer to an
+ <structname>sd_event</structname> structure.</para></listitem>
+ </varlistentry>
- <varlistentry>
- <term><constant>-ECHILD</constant></term>
+ <varlistentry>
+ <term><constant>-ECHILD</constant></term>
- <listitem><para>The event loop has been created in a different process.</para></listitem>
+
<listitem><para>The event loop has been created in a different process.</para></listitem>
- </varlistentry>
- </variablelist>
+ </varlistentry>
+ </variablelist>
+ </refsect2>
</refsect1>
<refsect1>
<title>Examples</title>
<example>
- <title>Integration in glib event loop</title>
+ <title>Integration in the GLib event loop</title>
<programlisting><xi:include href="glib-event-glue.c" parse="text" /></programlisting>
</example>
</refsect1>
- <refsect1>
- <title>Notes</title>
-
- <para><function>sd_event_get_fd()</function> is 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>
+ <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_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_event_ref</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>sd_event_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>epoll_ctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>
projects / thirdparty / systemd.git / blobdiff