[Lumiera] Question about Scheduler capabilities

[Ichthyostega]

Hi Lumi hackers,

while proceeding with the player and engine interfaces, it turns out
that we'll likely need the following capabilities of the Scheduler.
Most of this was already discussed, thus I'm asking rather for confirmation.
Is the following doable and possible with the Lumiera Scheduler as planned?

ordering of jobs
    Jobs can depend on other jobs; the scheduler ensures all prerequisites of
    a given job are met. This includes resources (media data) to be loaded.

job time window
    a job may (optionally) be defined to start within a specific time window.
    When it's not possible to meet that deadline, the job function will never
    be entered and the job is marked as failure.

failure propagation
    when a job fails, either due to an job internal error, or by timing glitch,
    any dependent jobs need to receive that failure state. Usually this means
    that these jobs are marked as failure too, and the propagation continues....

guaranteed execution
    but some special jobs are marked as "run reliably". These need to run
    in any case, even when prerequisite jobs fail — moreover it could be
    necessary that these special jobs receive a flag indicating normal
    state or failure. (I don't think we ever need to propagate more
    specific error information)


	Hermann