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Diffstat (limited to 'src/libsystemd/sd_event_now.xml')
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diff --git a/src/libsystemd/sd_event_now.xml b/src/libsystemd/sd_event_now.xml new file mode 100644 index 0000000000..2c83b0bcb5 --- /dev/null +++ b/src/libsystemd/sd_event_now.xml @@ -0,0 +1,146 @@ +<?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/>. +--> + +<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> + <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 <systemd/sd-event.h></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> + </refsect1> + + <refsect1> + <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> + </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> |