sd_bus_message_get_monotonic_usec, sd_bus_message_get_realtime_usec, sd_bus_message_get_seqnum — Retrieve the sender timestamps and sequence number of a message
returns the monotonic timestamp of the time the
message was sent. This value is in microseconds since
CLOCK_MONOTONIC" epoch, see
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
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
is a suitable globally unique identifier for bus
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 sd_bus_negotiate_timestamp(3) call.
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_negotiate_timestamp(3).
interfaces are available as a shared library, which
can be compiled and linked to with the