[patch][commit] Prioritization of Scheduler Events

[Dave Brolley]

Hi,

While looking into some bugs with the recent dynamic configuration work, 
it became apparent that it would be necessary to have some control over 
when the dynamic configurator component's step! pin was drive in 
relation to the scheduling of other components. In particular, it is 
desirable that the dynamic configurator be stepped (if necessary) first, 
before other components scheduled at the same time are stepped. In this 
way, all components are stepped under the same configuration.

After some experimentation with sequence components, it occurred to me 
that this could be easily accomplished if the events scheduled at a 
given time could be prioritized, so that they are dispatched in a 
predictable order.

I've committed an implementation which adds a new attribute, N-priority, 
to each output of the generic_scheduler component which is analogous to 
the existing N-event and N-control pins and the N-time and N-regular 
attributes. N-priority is assigned an integral value with the default 
being zero. The higher the value, the higher the priority of that 
output. When multiple events are scheduled at the same time, they are 
dispatched in priority order.

There is no change for existing ports since all outputs will be assigned 
a priority of zero.

Also included in this patch is a change to assign the gprof component a 
priority of 1. In this way it will always take a sample before the cpu 
is driven.

The dynamic configurator component is assigned a priority of 2, so that 
the entire system is configured (if necessary) before any other 
components are stepped.

Note that there is no change to the number of events being dispatched. 
Simply a prioritization.

Let me know if there are any problems or concerns.

Dave

Dave

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