-<?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">
-
-<!--
- This file is part of systemd.
-
- Copyright 2015 Lennart Poettering
-
- 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/>.
--->
+<?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_now" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_event_now</title>
<productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Lennart</firstname>
- <surname>Poettering</surname>
- <email>lennart@poettering.net</email>
- </author>
- </authorgroup>
</refentryinfo>
<refmeta>
<refsect1>
<title>Description</title>
- <para><function>sd_event_now()</function> returns the timestamp
- the most recent event loop iteration began. This timestamp is
- taken right after returning from the event sleep, and before
+ <para><function>sd_event_now()</function> returns the time when
+ the most recent event loop iteration began. A timestamp
+ is taken right after returning from the event sleep, and before
dispatching any event sources. The <parameter>event</parameter>
- parameter takes the even loop object to retrieve the timestamp
+ parameter specifies the event loop object to retrieve the timestamp
from. The <parameter>clock</parameter> parameter specifies the clock to
retrieve the timestamp for, and is one of
- <constant>CLOCK_REALTIME</constant> (or its equivalent
+ <constant>CLOCK_REALTIME</constant> (or equivalently
<constant>CLOCK_REALTIME_ALARM</constant>),
- <constant>CLOCK_MONOTONIC</constant> or
- <constant>CLOCK_BOOTTIME</constant> (or its equivalent
- <constant>CLOCK_BOOTTIME_ALARM</constant>), see <citerefentry
- project='man-pages'><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ <constant>CLOCK_MONOTONIC</constant>, or
+ <constant>CLOCK_BOOTTIME</constant> (or equivalently
+ <constant>CLOCK_BOOTTIME_ALARM</constant>), see
+ <citerefentry project='man-pages'><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
for more information on the various clocks. The retrieved
timestamp is stored in the <parameter>usec</parameter> parameter,
in µs since the clock's epoch. If this function is invoked before
- the first event loop iteration the current time is returned, as
+ the first event loop iteration, the current time is returned, as
reported by <function>clock_gettime()</function>. To distinguish
this case from a regular invocation the return value will be
- positive non-zero in this case, while it is zero when the returned
- timestamp refers to the actual event loop iteration.</para>
+ positive, and zero when the returned timestamp refers to an actual
+ event loop iteration.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
- <para>If the first event loop iteration has not run yet
- <function>sd_event_now()</function> returns the requested
- timestamp in <parameter>usec</parameter> and returns a positive,
- non-zero return value. Otherwise, on success it will return the
- iteration's timestamp in <parameter>usec</parameter> and 0 as
- return value. On failure, the call returns a negative errno-style
- error code.</para>
- </refsect1>
+ <para>If the first event loop iteration has not run yet <function>sd_event_now()</function> writes
+ current time to <parameter>usec</parameter> and returns a positive return value. Otherwise, it will
+ write the requested timestamp to <parameter>usec</parameter> and return 0. On failure, the call returns a
+ negative errno-style error code.</para>
- <refsect1>
- <title>Errors</title>
+ <refsect2>
+ <title>Errors</title>
+
+ <para>Returned values 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>An invalid parameter was passed.</para></listitem>
- <listitem><para>An invalid parameter was
- passed.</para></listitem>
+ </varlistentry>
- </varlistentry>
+ <varlistentry>
+ <term><constant>-EOPNOTSUPP</constant></term>
- <varlistentry>
- <term><constant>-ECHILD</constant></term>
+ <listitem><para>Unsupported clock type.</para></listitem>
+ </varlistentry>
- <listitem><para>The event loop object was created in a
- different process.</para></listitem>
- </varlistentry>
+ <varlistentry>
+ <term><constant>-ECHILD</constant></term>
- </variablelist>
+ <listitem><para>The event loop object was created in a different process.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect2>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
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