sd_bus_message_get_monotonic_usec() returns the monotonic timestamp
of the time the message was sent. This value is in microseconds since
the CLOCK_MONOTONIC epoch, see clock_gettime(2) for details.
Similarly, sd_bus_message_get_realtime_usec() 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 CLOCK_REALTIME
sd_bus_message_get_seqnum() 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 sd_id128_get_boot(3)) is a suitable
globally unique identifier for bus messages.
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.
These timestamps and the sequence number are attached to each message
by the kernel and cannot be manipulated by the sender.
Note that these timestamps are only available on some bus transports,
and only after support for them has been negotiated with the
On success, these calls return 0 or a positive integer. On failure,
these calls return a negative errno-style error code.
On success, the timestamp or sequence number is returned in the
specified 64-bit unsigned integer variable.
Returned errors may indicate the following problems:
A specified parameter is invalid.
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
sd_bus_message_get_realtime_usec(), and sd_bus_message_get_seqnum()
interfaces are available as a shared library, which can be compiled
and linked to with the libsystemd pkg-config(1) file.
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2017-03-13. If you dis‐
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systemd 233 SD_BUS_MESSAGE_GET_MONOTONIC_USEC(3)