man: explain that the timestamps on incoming kdbus messages are not necessarily monotonically increasing

This commit is contained in:
Lennart Poettering 2014-04-13 17:42:11 -07:00
parent 11fb37f16e
commit 6e0369b0ff
1 changed files with 10 additions and 3 deletions

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@ -92,9 +92,10 @@
<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 sent on the local
system. This sequence number is useful for determining
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
@ -102,6 +103,12 @@
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>