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Diffstat (limited to 'man/sd_bus_message_get_monotonic_usec.xml')
| -rw-r--r-- | man/sd_bus_message_get_monotonic_usec.xml | 319 |
1 files changed, 155 insertions, 164 deletions
diff --git a/man/sd_bus_message_get_monotonic_usec.xml b/man/sd_bus_message_get_monotonic_usec.xml index 290faf2a5b..42842116a0 100644 --- a/man/sd_bus_message_get_monotonic_usec.xml +++ b/man/sd_bus_message_get_monotonic_usec.xml @@ -1,6 +1,6 @@ <?xml version='1.0'?> <!--*-nxml-*--> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" - "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. @@ -23,168 +23,159 @@ <refentry id="sd_bus_message_get_monotonic_usec" conditional="ENABLE_KDBUS"> - <refentryinfo> - <title>sd_bus_message_get_monotonic_usec</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_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 <systemd/sd-bus.h></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 <literal>CLOCK_MONOTONIC</literal> epoch, see - <citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry> - for details.</para> - - <para>Similar, - <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 - <literal>CLOCK_REALTIME</literal> 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 busses 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> - </refsect1> - - <refsect1> - <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> - </refsect1> - - <refsect1> - <title>Notes</title> - - <para>The - <function>sd_bus_message_get_monotonic_usec()</function>, - <function>sd_bus_message_get_realtime_usec()</function>, - and <function>sd_bus_message_get_seqnum()</function> - interfaces are available as a shared library, which - can be compiled and linked to with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> - </refsect1> - - <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> + <refentryinfo> + <title>sd_bus_message_get_monotonic_usec</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_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 <systemd/sd-bus.h></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>Similar, + <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 busses 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> + </refsect1> + + <refsect1> + <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> + </refsect1> + + <refsect1> + <title>Notes</title> + + <para>The + <function>sd_bus_message_get_monotonic_usec()</function>, + <function>sd_bus_message_get_realtime_usec()</function>, and + <function>sd_bus_message_get_seqnum()</function> interfaces are + available as a shared library, which can be compiled and linked to + with the + <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> + file.</para> + </refsect1> + + <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> |