--- /dev/null
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!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 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_add_signal" conditional="ENABLE_KDBUS">
+
+ <refentryinfo>
+ <title>sd_event_add_signal</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>
+ <refentrytitle>sd_event_add_signal</refentrytitle>
+ <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>sd_event_add_signal</refname>
+ <refname>sd_event_source_get_signal</refname>
+
+ <refpurpose>Add a signal event source to an event loop</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
+
+ <funcprototype>
+ <funcdef>int <function>sd_event_add_signal</function></funcdef>
+ <paramdef>sd_event *<parameter>event</parameter></paramdef>
+ <paramdef>sd_event_source **<parameter>source</parameter></paramdef>
+ <paramdef>int <parameter>signal</parameter></paramdef>
+ <paramdef>sd_event_signal_handler_t <parameter>handler</parameter></paramdef>
+ <paramdef>void *<parameter>userdata</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>typedef int (*<function>sd_event_signal_handler_t</function>)</funcdef>
+ <paramdef>sd_event_source *<parameter>s</parameter></paramdef>
+ <paramdef>const struct signalfd_siginfo *<parameter>si</parameter></paramdef>
+ <paramdef>void *<parameter>userdata</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_event_source_get_signal</function></funcdef>
+ <paramdef>sd_event_source *<parameter>source</parameter></paramdef>
+ </funcprototype>
+
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><function>sd_event_add_signal()</function> adds a new signal
+ event source to an event loop object. The event loop is specified
+ in <parameter>event</parameter>, the event source is returned in
+ the <parameter>source</parameter> parameter. The
+ <parameter>signal</parameter> parameter specifies the signal to be handled
+ (see
+ <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>).
+ The <parameter>handler</parameter> must reference a function to
+ call when the signal is delivered or be <constant>NULL</constant>.
+ The handler function will be passed the
+ <parameter>userdata</parameter> pointer, which may be chosen
+ freely by the caller. The handler also receives a pointer to a
+ <structname>const struct signalfd_siginfo</structname> containing
+ the information about the received signal. See
+ <citerefentry><refentrytitle>signalfd</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for futher information.</para>
+
+ <para>Only a single handler may be installed for a specific
+ signal. The signal will be unblocked, and must be
+ blocked when the function is called. If the handler is not
+ specified (<parameter>handler</parameter> is
+ <constant>NULL</constant>), a default handler which causes the
+ program to exit will be used. By default, the handler is enabled
+ permanently (<constant>SD_EVENT_ON</constant>), but this may be
+ changed with
+ <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+ If the handler function returns a negative error code, it will be
+ disabled after the invocation, even if
+ <constant>SD_EVENT_ON</constant> mode is set.
+ </para>
+
+ <para><function>sd_event_source_get_signal()</function> retrieves
+ the configured signal number of a signal event source created
+ previously with <function>sd_event_add_signal()</function>. It
+ takes the event source object as the <parameter>source</parameter>
+ parameter.</para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Return Value</title>
+
+ <para>On success, these functions return 0 or a positive
+ integer. On failure, they return a negative errno-style error
+ code. </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Errors</title>
+
+ <para>Returned errors may indicate the following problems:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><varname>-ENOMEM</varname></term>
+
+ <listitem><para>Not enough memory to allocate an object.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>-EINVAL</varname></term>
+
+ <listitem><para>An invalid argument has been passed.</para></listitem>
+
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>-EBUSY</varname></term>
+
+ <listitem><para>An handler is already installed for this
+ signal or the signal was not blocked previously.</para></listitem>
+
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>-ESTALE</varname></term>
+
+ <listitem><para>The event loop is already terminated.</para></listitem>
+
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>-ECHILD</varname></term>
+
+ <listitem><para>The event loop has been created in a different process.</para></listitem>
+
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para><function>sd_event_add_signal()</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_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>
~ianmdlvl / elogind.git / blobdiff