this draft fills in the structure how to get from an invocation
of the engine service to the starting of actual CalcStream instances.
Basically the EngineService implementation is repsonsile to
instruct the Segmentation to provide a suitable Dispatcher.
This is necessary since the implementation of the job functions
calls through the VTable of the interface JobClosure. Thus this
interface (and the VTable definition) needs to reside within
some compilation unit linked together with the basic job class.
TODO: move class Job entirely into the Backend
basically I've changed my mind to prefer an
infinite JobPlanningSequence, which is just
evaluated partially. This removes the need to
embody the logic of planning chunk generation,
which really is a different concern.
decision: the base for any deadline calculations
is the expected real time corresponding to the grid origin.
This value is contained in the Timings record.
this clarifies the relation of TimeAnchor and Timings,
the latter act as a general spec and abstracted grid,
while the latter actually performs the conversion and
deadline checking
the solution is to introduce a superinterface
and let Dispatcher augment that with the specific parts.
This way, the Job planning only has to rely on the
rather generic stuff (TimeAnchor, FrameCoord)
NOTE: this commit makes the whole JobPlanning machinery
compilable for the first time!
..the Idea is to rely on some kind of service,
to break the cyclic dependency with the Dispatcher.
But I seem unable to find a natural location or
concept to house that service.
basically we had two lines of doubly nested capsules, due to
using the IterAdaptor template. Actually, the evaluation stack
within JobTicket can be considered an implementation detail and
thus doesn't require an iterator interface; the intention is to
use this through JobPlanning solely.
Thus this reworking removes the special iterator within JobTicket,
but retains the idea of exposing the "current" JobTicket through
a smart pointer or operator->()
work done during the FrOSCon travel
especially the exploration stack is pushed down
first successful definition of all the JobPlanning classes
just the framework of classes necessary to pass the compiler;
all implementation is still stubbed
brainstorming how to implement the job planning stage
the idea is to built on top of the IterExplorer,
but have the "stack" of re-evaluation integrated
into a custom type, which exploits the static
node network structure to avoid heap allocations
solution idea: again use a builder function?
without any trickery, we'll always get two indirections.
Thus, the decision is to turn the 2nd indirection
into a VTable call; this way, basically the JobClosure
also acts as job functor itself.
this draft is based on
- Cehteh's draft for the scheduler
- my plannings about segmentation and JobTicket
it defines "Job" as a closure which can be invoked
from plain-C, using the information in the
job descriptor datastructure
also touches the question how to represent the job
descriptor datastructure. @Cehteh: I've just pasted
in your preliminary data struct definitinons
from the relevant mailing list discussions.
