-<?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">
-
-<!--
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- Copyright 2015 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.
-
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- You should have received a copy of the GNU Lesser General Public License
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--->
+<?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+ -->
<refentry id="sd_event_wait" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_event_wait</title>
<productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Tom</firstname>
- <surname>Gundersen</surname>
- <email>teg@jklm.no</email>
- </author>
- </authorgroup>
</refentryinfo>
<refmeta>
<refname>sd_event_prepare</refname>
<refname>sd_event_dispatch</refname>
<refname>sd_event_get_state</refname>
+ <refname>sd_event_get_iteration</refname>
<refname>SD_EVENT_INITIAL</refname>
<refname>SD_EVENT_PREPARING</refname>
<refname>SD_EVENT_ARMED</refname>
<paramdef>sd_event *<parameter>event</parameter></paramdef>
</funcprototype>
+ <funcprototype>
+ <funcdef>int <function>sd_event_get_iteration</function></funcdef>
+ <paramdef>sd_event *<parameter>event</parameter></paramdef>
+ <paramdef>uint64_t *<parameter>ret</parameter></paramdef>
+ </funcprototype>
+
</funcsynopsis>
</refsynopsisdiv>
determine the state the event loop is currently in. It returns one
of the states described below.</para>
- <para>All four functions take, as the first argument, the event
- loop object <parameter>event</parameter> that has been created
- with <function>sd_event_new()</function>. The timeout for
- <function>sd_event_wait()</function> is specified in
- <parameter>usec</parameter> in milliseconds. <constant>(uint64_t)
- -1</constant> may be used to specify an infinite timeout.</para>
+ <para><function>sd_event_get_iteration()</function> may be used to determine the current iteration of the event
+ loop. It returns an unsigned 64bit integer containing a counter that increases monotonically with each iteration of
+ the event loop, starting with 0. The counter is increased at the time of the
+ <function>sd_event_prepare()</function> invocation.</para>
+
+ <para>All five functions take, as the first argument, the event loop object <parameter>event</parameter> that has
+ been created with <function>sd_event_new()</function>. The timeout for <function>sd_event_wait()</function> is
+ specified in <parameter>usec</parameter> in microseconds. <constant>(uint64_t) -1</constant> may be used to
+ specify an infinite timeout.</para>
</refsect1>
<refsect1>
<listitem><para>An event source is currently being prepared,
i.e. the preparation handler is currently being executed, as
set with
- <citerefentry><refentrytitle>sd_event_set_prepare</refentrytitle><manvolnum>3</manvolnum></citerefentry>. This
+ <citerefentry><refentrytitle>sd_event_source_set_prepare</refentrytitle><manvolnum>3</manvolnum></citerefentry>. This
state is only seen in the event source preparation handler
that is invoked from the
<function>sd_event_prepare()</function> call and is
<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. In case
- of <function>sd_event_prepare()</function> and
- <function>sd_event_wait()</function>, a positive, non-zero return
- code indicates that events are ready to be processed and zero
- indicates that no events are ready. In case of
- <function>sd_event_dispatch()</function>, a positive, non-zero
- return code indicates that the event loop returned to its initial
- state and zero indicates the event loop has
- exited. <function>sd_event_get_state()</function> returns a
- positive or zero state on success.</para>
- </refsect1>
+ <para>On success, these functions return 0 or a positive integer. On failure, they return a negative
+ errno-style error code. In case of <function>sd_event_prepare()</function> and
+ <function>sd_event_wait()</function>, a positive, non-zero return code indicates that events are ready to
+ be processed and zero indicates that no events are ready. In case of
+ <function>sd_event_dispatch()</function>, a positive, non-zero return code indicates that the event loop
+ returned to its initial state and zero indicates the event loop has
+ exited. <function>sd_event_get_state()</function> returns a positive or zero state on success.</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>The <parameter>event</parameter> parameter is
- invalid or <constant>NULL</constant>.</para></listitem>
- </varlistentry>
+ <listitem><para>The <parameter>event</parameter> parameter is invalid or <constant>NULL</constant>.
+ </para></listitem>
+ </varlistentry>
- <varlistentry>
- <term><constant>-EBUSY</constant></term>
+ <varlistentry>
+ <term><constant>-EBUSY</constant></term>
- <listitem><para>The event loop object is not in the right
- state.</para></listitem>
- </varlistentry>
+ <listitem><para>The event loop object is not in the right state.</para></listitem>
+ </varlistentry>
- <varlistentry>
- <term><constant>-ESTALE</constant></term>
+ <varlistentry>
+ <term><constant>-ESTALE</constant></term>
- <listitem><para>The event loop is already terminated.</para></listitem>
+
<listitem><para>The event loop is already terminated.</para></listitem>
- </varlistentry>
+ </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>
+ </varlistentry>
- </variablelist>
+ </variablelist>
- <para>Other errors are possible, too.</para>
+ <para>Other errors are possible, too.</para>
+ </refsect2>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
<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_inotify</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_add_defer</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_event_add_exit</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_event_add_post</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_run</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_source_set_prepare</refentrytitle><manvolnum>3</manvolnum></citerefentry>
projects / thirdparty / systemd.git / blobdiff