Major re-factor of the common_time (formally aah_timesrv) service in
preparation for up-integration into Android master. This work
includes bug fixes, new features, and general code cleanup. High
points are listed below.
+ CommonClock interface has been enhanced to allow querying of many
more low level synchronization details; mostly for debugging, but in
theory useful to an application as well.
+ CommonTimeConfig interface has been implemented. This allows a
management process to configure a number of different parameters
(many of them new) to control the behavior of the common_time
service. Most importantly, the time service can be bound to a
specific network interface and should only operate on that interface
an no others.
+ Enhance log messages to be more useful in determining what the time
service state machine is doing and why.
+ Enhance information provided by dumpsys to provide many more details
about the quality of time sync and the network conditions which gave
rise to the current quality conditions.
Features, features, features....
+ Add a feature which lets the high level choose a different master
election endpoint so that multiple time synchronization domains can
co-exist on the same subnet (mostly to support a potential use case
of multiple home domains in a multiple dwelling environment like a
hotel, dormitory or apartment complex).
+ Add a feature which lets the high level assign a 64-bit group ID
which allows partitioning of time synchronization domains even when
the master election endpoint is shared (as it might be if broadcast
is being used instead of multicast)
+ Add an auto-disable feature which lets the time service drop into
network-less mode when there are no active clients of the
common_time service in the device. Mostly for phones, this allows
phones to not consume network/battery resources when they don't need
to maintain common time.
+ Add a feature which lets the high level choose the priority of the
common_time service in the master election protocol. This allows
high level decisions about things like mobile vs non-mobile, wired
ethernet vs WiFi to affect who ends up with the job of master on a
given network. Priority overrides at the low level also allow
clients coming in from network-less mode to lower their effective
priority as they join a new network so as to not disrupt any
stable long-running timeline which may already be active on the
network.
+ Add the ability to control some of the core parameters of the time
sync service which effect network load (like the sync polling
interval and the master announce interval)
Change-Id: I71af15a83cfa5ef0417b406928967fb9e02f55c6
354edbc80e