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authorZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>2014-09-25 17:27:33 -0400
committerZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>2014-09-25 18:19:03 -0400
commitedf2573743b25273bee020230a60f1a054b8ec60 (patch)
tree7af25ea5dada5c629011a4deec4172a89383a0c5 /man
parent3144ebcad37422dd85220915d37e7e9eea36564a (diff)
man: add sd_event_add_child(3)
Diffstat (limited to 'man')
-rw-r--r--man/sd_event_add_child.xml205
-rw-r--r--man/sd_event_add_signal.xml1
-rw-r--r--man/sd_event_add_time.xml1
3 files changed, 207 insertions, 0 deletions
diff --git a/man/sd_event_add_child.xml b/man/sd_event_add_child.xml
new file mode 100644
index 000000000..a3b4d85ac
--- /dev/null
+++ b/man/sd_event_add_child.xml
@@ -0,0 +1,205 @@
+<?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_child" conditional="ENABLE_KDBUS">
+
+ <refentryinfo>
+ <title>sd_event_add_child</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_child</refentrytitle>
+ <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>sd_event_add_child</refname>
+ <refname>sd_event_source_get_child_pid</refname>
+
+ <refpurpose>Add a child state change event source to an event loop</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
+
+ <funcprototype>
+ <funcdef>int <function>sd_event_add_child</function></funcdef>
+ <paramdef>sd_event *<parameter>event</parameter></paramdef>
+ <paramdef>sd_event_source **<parameter>source</parameter></paramdef>
+ <paramdef>pid_t <parameter>pid</parameter></paramdef>
+ <paramdef>int <parameter>options</parameter></paramdef>
+ <paramdef>sd_event_child_handler_t <parameter>handler</parameter></paramdef>
+ <paramdef>void *<parameter>userdata</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>typedef int (*<function>sd_event_child_handler_t</function>)</funcdef>
+ <paramdef>sd_event_source *<parameter>s</parameter></paramdef>
+ <paramdef>const siginfo_t *<parameter>si</parameter></paramdef>
+ <paramdef>void *<parameter>userdata</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_event_source_get_child_pid</function></funcdef>
+ <paramdef>sd_event_source *<parameter>source</parameter></paramdef>
+ <paramdef>pid_t *<parameter>pid</parameter></paramdef>
+ </funcprototype>
+
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><function>sd_event_add_child()</function> adds a new child
+ state change 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>pid</parameter> parameter specifies the process to
+ watch. The <parameter>handler</parameter> must reference a
+ function to call when the process changes state. 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
+ siginfo_t</structname> structure containing the information about
+ the event. The <parameter>options</parameter> parameter determines
+ which state changes will be watched for. It must contain an OR-ed
+ mask of <constant>WEXITED</constant> (watch for the child
+ terminating), <constant>WSTOPPED</constant> (watch for the child
+ being stopped by a signal), and <constant>WCONTINUED</constant>
+ (watch for the child being resumed by a signal). See
+ <citerefentry><refentrytitle>waitid</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for futher information.</para>
+
+ <para>Only a single handler may be installed for a specific
+ child. The handler is enabled
+ for a single event (<constant>SD_EVENT_ONESHOT</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_child_pid()</function>
+ retrieves the configured <parameter>pid</parameter> of a child
+ state change event source created previously with
+ <function>sd_event_add_child()</function>. It takes the event
+ source object as the <parameter>source</parameter> parameter and a
+ pointer to <type>pid_t</type> to return the result in.
+ </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. This includes
+ specyfing an empty mask in <parameter>options</parameter> or a mask
+ which constains values different than a combination of
+ <constant>WEXITED</constant>, <constant>WSTOPPED</constant>, and
+ <constant>WCONTINUED</constant>.
+ </para></listitem>
+
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>-EBUSY</varname></term>
+
+ <listitem><para>An handler is already installed for this
+ child.</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_child()</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_add_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>
diff --git a/man/sd_event_add_signal.xml b/man/sd_event_add_signal.xml
index 2344fb3c0..2b656b67a 100644
--- a/man/sd_event_add_signal.xml
+++ b/man/sd_event_add_signal.xml
@@ -189,6 +189,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
<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_add_child</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>
diff --git a/man/sd_event_add_time.xml b/man/sd_event_add_time.xml
index d3775e5d5..e64ed8e20 100644
--- a/man/sd_event_add_time.xml
+++ b/man/sd_event_add_time.xml
@@ -249,6 +249,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
<citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_new</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>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_source_set_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>