tree 060434ea4946d470b2f16fb5728dfa3dea78a0db
parent fe17effce3dc91e9d4e33c7aa705aed9e8bc138e
author Brad Bishop <bradleyb@fuzziesquirrel.com> 1510716783 -0500
committer Brad Bishop <bradleyb@fuzziesquirrel.com> 1510718444 -0500

Claim a stable well known busname

Prior to this patch readd instances claim a busname with a format of:

xyz.openbmc_project.Hwmon.Hwmon<N> where N is the hwmon sysfs class
instance.

This is problematic for client applications that cache sensor object
busname mappings for objects provided by readd.  When readd instances
restart (due to udev events) the hwmon sysfs class index may have changed,
resulting in clients connecting to the wrong service instance.

Address this by ensuring readd instances claim the same name every
time they are started:

xyz.openbmc_project.Hwmon-<ID>.Hwmon1

Where ID is a std::hash of the /sys/devices path backing the hwmon
instance.

Additionally, add a trailing API version as recommended best practice
by the D-Bus specification.

Change-Id: Idd0057ce883a49c1e828fb54fede27ea14022d6a
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>