Martin Stein 8750e373a0 timer session: add elapsed_us method
As timer sessions are not expected to be microseconds precise (because
of RPC latency and scheduling), the session interface provided only a
method 'elapsed_ms' although the back end of this method in the timer
driver works with microseconds.

However, in some cases it makes sense to have a method 'elapsed_us'. The
values it returns might be milliseconds away from the "real" time but it
allows you to work with delays smaller than a millisecond without
getting a zero delta value.

This commit is motivated by the need for fast bursts of calibration
steps for the time interpolation in the new timer connection.

Ref #2400
2017-08-23 14:08:36 +02:00
..
2017-08-23 14:08:36 +02:00