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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-or-later -->
+
+<refentry id="sd_event_now" xmlns:xi="http://www.w3.org/2001/XInclude">
+
+ <refentryinfo>
+ <title>sd_event_now</title>
+ <productname>systemd</productname>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>sd_event_now</refentrytitle>
+ <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>sd_event_now</refname>
+
+ <refpurpose>Retrieve current event loop iteration timestamp</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include &lt;systemd/sd-event.h&gt;</funcsynopsisinfo>
+
+ <funcprototype>
+ <funcdef>int <function>sd_event_now</function></funcdef>
+ <paramdef>sd_event *<parameter>event</parameter></paramdef>
+ <paramdef>clockid_t <parameter>clock</parameter></paramdef>
+ <paramdef>uint64_t *<parameter>usec</parameter></paramdef>
+ </funcprototype>
+
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <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 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 equivalently
+ <constant>CLOCK_REALTIME_ALARM</constant>),
+ <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
+ reported by <function>clock_gettime()</function>. To distinguish
+ this case from a regular invocation the return value will be
+ 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> 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>
+
+ <refsect2>
+ <title>Errors</title>
+
+ <para>Returned values may indicate the following problems:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><constant>-EINVAL</constant></term>
+
+ <listitem><para>An invalid parameter was passed.</para></listitem>
+
+ </varlistentry>
+
+ <varlistentry>
+ <term><constant>-EOPNOTSUPP</constant></term>
+
+ <listitem><para>Unsupported clock type.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><constant>-ECHILD</constant></term>
+
+ <listitem><para>The event loop object was created in a different process.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect2>
+ </refsect1>
+
+ <xi:include href="libsystemd-pkgconfig.xml" />
+
+ <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 project='man-pages'><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>