RFC: new design of phosphor-time-manager on sdbusplus

[Mine]

Hi Patrick,

On Tue, Jan 17, 2017 at 3:44 AM, Patrick Williams <patrick at stwcx.xyz> wrote:
>
> On Fri, Jan 13, 2017 at 03:42:50PM +0800, Mine wrote:
> > New Design
> >
> > Create two objects:
>
> You mean 'classes' or 'objects'?  I think you mean two classes, which
> initially we will only have 1 instance of each.  Please make sure the
> HostEpoch implementation can relatively-easily be enhanced to have
> multiple instances.

I should be meant to create two "instances" on the bus, eventually it looks
something like:
```
xyz.openbmc_project.Time.Manager
    /xyz/openbmc_project/time/host_epoch
        org.freedesktop.DBus.Peer
        org.freedesktop.DBus.Introspectable
        org.freedesktop.DBus.Properties
        xyz.openbmc_project.Time.EpochTime
    /xyz/openbmc_project/time/bmc_epoch
        org.freedesktop.DBus.Peer
        org.freedesktop.DBus.Introspectable
        org.freedesktop.DBus.Properties
        xyz.openbmc_project.Time.EpochTime

```
The service's BUSNAME is still `xyz.openbmc_project.Time.Manager`, and
it creates two objects, one for BmcEpoch and the other for HostEpoch, who
both implement xyz.openbmc_project.Time.EpochTime interface.

>
> >    - BmcEpoch
> >    - HostEpoch
> >
> > They both implements EpochTime interface.
> >
> > For BmcEpoch:
> >
> >    - When elapsed() is called, return BMC time;
> >    - When elapsed(us) is called, use above SetTime(“bmc”) logic
> >
> > For HostEpoch:
> >
> >    - When elapsed() is called, return HOST time;
> >    - When elapsed(us) is called, use above SetTime(“host”) logic.
>
> Seems ok.
>
> The errors also need to be converted to dbus-defined errors, right?
>
> > And there will be no “curr_time_mode/owner” or “requested_time_mode/owner”
> > properties on DBUS.
>
> So these are only stored in phosphor-settingsd now or are they also used
> internally for decisions?  I believe the previous implementation had
> them exposed more for debug purposes.  Are you going to add them to the
> journal at least?

Yes, the time_mode and time_owner are still stored in
phosphor-settingsd, and they
are used internally by phosphor-time-manager, which will register
callback for the
settings' change and handled accordingly.
The difference from the previous implementation is that we do not expose these
settings in time-manager's DBus now.

What do you mean by "add them to the journal"?

>
> --
> Patrick Williams