[systemd-devel] [PATCH 3/3] run: introduce timer support option

[WaLyong Cho]

On 10/28/2014 07:22 PM, Lennart Poettering wrote:
> On Tue, 28.10.14 12:09, WaLyong Cho (walyong.cho at samsung.com) wrote:
> 
>>> The AccuracySec= and WakeSystem= stuff I think we don't need to cover
>>> with a command line argument of its own, we can cover that with
>>> --property=.
>>>
>> Rework is almost done. Now I'm testing. But the AccuracySec= and
>> WakeSystem= options are hard to deal with --property= option. Currently
>> the --property= option of systemd-run is designed for service or scope
>> unit. If that option is specified then given string is parsed again by
>> bus_append_unit_property_assignment(). We can AccuracySec=/WakeSystem=
>> option to there. But we have to split given properties(by --property
>> option) according to which unit can have that properties.
> 
> Hmm, the implied rule here is that we do not intrdouce properties with
> the same name on different unit types that do not shrae the same
> signature. That way it really doesn't matter to specify which
> properties can be parsed for a specific unit type on the client side,
> since the server side will already know.
> 
> Or in other words: go ahead, add this to
> bus_append_unit_property_assignment(), and the server side will deny
> what it doesn't like.
> 
Honestly, I'd tried. But that was denied by server side. The properties
of received transient unit are set by bus_unit_set_properties.
Currently, bus_unit_set_properties return fail for unknown property. See
this example,

systemd-run --on-unit-active=30 --property="AccuracySec=100ms" touch
/tmp/hello

On the client side, systemd-run ship the "AccuracySec=100ms" option to
both timer and service(aux unit) property. Because
bus_append_unit_property_assignment don't know that is working on which
kind of unit. Anyway the message is successfully made and sent to
systemd(server side). There is no problem on parse timer unit
properties. But when parse aux unit(maybe run-xxx.service),
bus_unit_set_properties try to parse "AccuracySec=" but it can not. And
return fail with "Cannot set property AccuracySec, or unknown property."

I think we have to pass unit type to bus_append_unit_property_assignment
and only be assigned what be supported by its unit type.

> Hope that makes sense,
> 
> Lennart
>