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11a1589223
Files which are installed as-is (any .service and other unit files, .conf files, .policy files, etc), are left as is. My assumption is that SPDX identifiers are not yet that well known, so it's better to retain the extended header to avoid any doubt. I also kept any copyright lines. We can probably remove them, but it'd nice to obtain explicit acks from all involved authors before doing that.
136 lines
4.6 KiB
XML
136 lines
4.6 KiB
XML
<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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<!--
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SPDX-License-Identifier: LGPL-2.1+
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This file is part of systemd.
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Copyright 2015 Lennart Poettering
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-->
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<refentry id="sd_event_now" xmlns:xi="http://www.w3.org/2001/XInclude">
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<refentryinfo>
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<title>sd_event_now</title>
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<productname>systemd</productname>
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<authorgroup>
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<author>
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<contrib>Developer</contrib>
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<firstname>Lennart</firstname>
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<surname>Poettering</surname>
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<email>lennart@poettering.net</email>
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</author>
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</authorgroup>
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</refentryinfo>
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<refmeta>
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<refentrytitle>sd_event_now</refentrytitle>
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<manvolnum>3</manvolnum>
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</refmeta>
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<refnamediv>
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<refname>sd_event_now</refname>
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<refpurpose>Retrieve current event loop iteration timestamp</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<funcsynopsis>
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<funcsynopsisinfo>#include <systemd/sd-event.h></funcsynopsisinfo>
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<funcprototype>
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<funcdef>int <function>sd_event_now</function></funcdef>
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<paramdef>sd_event *<parameter>event</parameter></paramdef>
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<paramdef>clockid_t <parameter>clock</parameter></paramdef>
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<paramdef>uint64_t *<parameter>usec</parameter></paramdef>
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</funcprototype>
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</funcsynopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para><function>sd_event_now()</function> returns the time when
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the most recent event loop iteration began. A timestamp
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is taken right after returning from the event sleep, and before
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dispatching any event sources. The <parameter>event</parameter>
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parameter specifies the event loop object to retrieve the timestamp
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from. The <parameter>clock</parameter> parameter specifies the clock to
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retrieve the timestamp for, and is one of
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<constant>CLOCK_REALTIME</constant> (or equivalently
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<constant>CLOCK_REALTIME_ALARM</constant>),
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<constant>CLOCK_MONOTONIC</constant>, or
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<constant>CLOCK_BOOTTIME</constant> (or equivalently
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<constant>CLOCK_BOOTTIME_ALARM</constant>), see
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<citerefentry project='man-pages'><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
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for more information on the various clocks. The retrieved
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timestamp is stored in the <parameter>usec</parameter> parameter,
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in µs since the clock's epoch. If this function is invoked before
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the first event loop iteration, the current time is returned, as
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reported by <function>clock_gettime()</function>. To distinguish
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this case from a regular invocation the return value will be
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positive, and zero when the returned timestamp refers to an actual
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event loop iteration.</para>
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</refsect1>
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<refsect1>
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<title>Return Value</title>
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<para>If the first event loop iteration has not run yet
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<function>sd_event_now()</function> writes current time to
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<parameter>usec</parameter> and returns a positive return value.
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Otherwise, it will write the requested timestamp to <parameter>usec</parameter>
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and return 0. On failure, the call returns a negative errno-style
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error code.</para>
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</refsect1>
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<refsect1>
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<title>Errors</title>
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<para>Returned values may indicate the following problems:</para>
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<variablelist>
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<varlistentry>
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<term><constant>-EINVAL</constant></term>
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<listitem><para>An invalid parameter was
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passed.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>-EOPNOTSUPP</constant></term>
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<listitem><para>Unsupported clock type.
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</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>-ECHILD</constant></term>
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<listitem><para>The event loop object was created in a
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different process.</para></listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<xi:include href="libsystemd-pkgconfig.xml" />
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<refsect1>
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<title>See Also</title>
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<para>
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<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>sd_event_add_time</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
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<citerefentry project='man-pages'><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
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</para>
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</refsect1>
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</refentry>
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