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diff --git a/man/sd_event_add_child.xml b/man/sd_event_add_child.xml new file mode 100644 index 0000000000..a3b4d85ac8 --- /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 <systemd/sd-bus.h></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> |