Adding upstream version 252.22.upstream/252.22upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 141 insertions, 0 deletions

diff --git a/man/sd_bus_message_get_monotonic_usec.xml b/man/sd_bus_message_get_monotonic_usec.xml
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+<?xml version='1.0'?> <!--*-nxml-*-->
+<!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_bus_message_get_monotonic_usec"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <refentryinfo>
+    <title>sd_bus_message_get_monotonic_usec</title>
+    <productname>systemd</productname>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>sd_bus_message_get_monotonic_usec</refentrytitle>
+    <manvolnum>3</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>sd_bus_message_get_monotonic_usec</refname>
+    <refname>sd_bus_message_get_realtime_usec</refname>
+    <refname>sd_bus_message_get_seqnum</refname>
+    <refpurpose>Retrieve the sender timestamps and sequence number of a message</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_message_get_monotonic_usec</function></funcdef>
+        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
+        <paramdef>uint64_t *<parameter>usec</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_message_get_realtime_usec</function></funcdef>
+        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
+        <paramdef>uint64_t *<parameter>usec</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_message_get_seqnum</function></funcdef>
+        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
+        <paramdef>uint64_t *<parameter>seqnum</parameter></paramdef>
+      </funcprototype>
+    </funcsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><function>sd_bus_message_get_monotonic_usec()</function>
+    returns the monotonic timestamp of the time the message was sent.
+    This value is in microseconds since the
+    <constant>CLOCK_MONOTONIC</constant> epoch, see
+    <citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+    for details.</para>
+
+    <para>Similarly,
+    <function>sd_bus_message_get_realtime_usec()</function> returns
+    the realtime (wallclock) timestamp of the time the message was
+    sent. This value is in microseconds since Jan 1st, 1970, i.e. in
+    the <constant>CLOCK_REALTIME</constant> clock.</para>
+
+    <para><function>sd_bus_message_get_seqnum()</function> returns the
+    kernel-assigned sequence number of the message. The kernel assigns
+    a global, monotonically increasing sequence number to all messages
+    transmitted on the local system, at the time the message was sent.
+    This sequence number is useful for determining message send order,
+    even across different buses of the local system. The sequence
+    number combined with the boot ID of the system (as returned by
+    <citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>)
+    is a suitable globally unique identifier for bus messages.</para>
+
+    <para>Note that the sending order and receiving order of messages
+    might differ, in particular for broadcast messages. This means
+    that the sequence number and the timestamps of messages a client
+    reads are not necessarily monotonically increasing.</para>
+
+    <para>These timestamps and the sequence number are attached to
+    each message by the kernel and cannot be manipulated by the
+    sender.</para>
+
+    <para>Note that these timestamps are only available on some bus
+    transports, and only after support for them has been negotiated
+    with the
+    <citerefentry><refentrytitle>sd_bus_negotiate_timestamp</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    call.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Return Value</title>
+
+    <para>On success, these calls return 0 or a positive integer. On
+    failure, these calls return a negative errno-style error
+    code.</para>
+
+    <para>On success, the timestamp or sequence number is returned in
+    the specified 64-bit unsigned integer variable.</para>
+
+    <refsect2>
+      <title>Errors</title>
+
+      <para>Returned errors may indicate the following problems:</para>
+
+      <variablelist>
+        <varlistentry>
+          <term><constant>-EINVAL</constant></term>
+
+          <listitem><para>A specified parameter is invalid.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ENODATA</constant></term>
+
+          <listitem><para>No timestamp or sequence number information is attached to the passed message. This
+          error is returned if the underlying transport does not support timestamping or assigning of
+          sequence numbers, or if this feature has not been negotiated with
+          <citerefentry><refentrytitle>sd_bus_negotiate_timestamp</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</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-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_negotiate_timestamp</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>