mirror of
https://github.com/systemd/systemd.git
synced 2024-11-23 18:23:32 +08:00
120 lines
5.2 KiB
XML
120 lines
5.2 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
|
|
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
|
|
|
|
<refentry id="sd_journal_get_realtime_usec"
|
|
xmlns:xi="http://www.w3.org/2001/XInclude">
|
|
|
|
<refentryinfo>
|
|
<title>sd_journal_get_realtime_usec</title>
|
|
<productname>systemd</productname>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>sd_journal_get_realtime_usec</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>sd_journal_get_realtime_usec</refname>
|
|
<refname>sd_journal_get_monotonic_usec</refname>
|
|
<refpurpose>Read timestamps from the current journal entry</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/sd-journal.h></funcsynopsisinfo>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_journal_get_realtime_usec</function></funcdef>
|
|
<paramdef>sd_journal *<parameter>j</parameter></paramdef>
|
|
<paramdef>uint64_t *<parameter>usec</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_journal_get_monotonic_usec</function></funcdef>
|
|
<paramdef>sd_journal *<parameter>j</parameter></paramdef>
|
|
<paramdef>uint64_t *<parameter>usec</parameter></paramdef>
|
|
<paramdef>sd_id128_t *<parameter>boot_id</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para><function>sd_journal_get_realtime_usec()</function> gets the
|
|
realtime (wallclock) timestamp of the current journal entry. It
|
|
takes two arguments: the journal context object and a pointer to a
|
|
64-bit unsigned integer to store the timestamp in. The timestamp
|
|
is in microseconds since the epoch, i.e.
|
|
<constant>CLOCK_REALTIME</constant>.</para>
|
|
|
|
<para><function>sd_journal_get_monotonic_usec()</function> gets
|
|
the monotonic timestamp of the current journal entry. It takes
|
|
three arguments: the journal context object, a pointer to a 64-bit
|
|
unsigned integer to store the timestamp in, as well as a 128-bit
|
|
ID buffer to store the boot ID of the monotonic timestamp. The
|
|
timestamp is in microseconds since boot-up of the specific boot,
|
|
i.e. <constant>CLOCK_MONOTONIC</constant>. Since the monotonic
|
|
clock begins new with every reboot, it only defines a well-defined
|
|
point in time when used together with an identifier identifying
|
|
the boot. See
|
|
<citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
for more information. If the boot ID parameter is passed
|
|
<constant>NULL</constant>, the function will fail if the monotonic
|
|
timestamp of the current entry is not of the current system
|
|
boot.</para>
|
|
|
|
<para>Note that these functions will not work before
|
|
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
(or related call) has been called at least
|
|
once, in order to position the read pointer at a valid entry.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Return Value</title>
|
|
|
|
<para><function>sd_journal_get_realtime_usec()</function> and
|
|
<function>sd_journal_get_monotonic_usec()</function> returns 0 on
|
|
success or a negative errno-style error code. If the boot ID
|
|
parameter was passed <constant>NULL</constant> and the monotonic
|
|
timestamp of the current journal entry is not of the current
|
|
system boot, <constant>-ESTALE</constant> is returned by
|
|
<function>sd_journal_get_monotonic_usec()</function>.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Notes</title>
|
|
|
|
<xi:include href="threads-aware.xml" xpointer="strict"/>
|
|
|
|
<xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>History</title>
|
|
<para><function>sd_journal_get_realtime_usec()</function> and
|
|
<function>sd_journal_get_monotonic_usec()</function> were added in version 187.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>See Also</title>
|
|
|
|
<para><simplelist type="inline">
|
|
<member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_journal_open</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_journal_get_data</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_journal_get_seqnum</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_journal_get_cutoff_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
</simplelist></para>
|
|
</refsect1>
|
|
|
|
</refentry>
|