[Insight-users] State Management in the Finite Difference Solver Hierarchy

[Brady McCary]

Insight-Users,

A rough overview of the FDSH is as follows:

1. There are two objects: the filter and the function.
2. The filter evaluates the function as the filter deems necessary.
3. Since the filter controls the evaluation order/strategy, the filter
may thread the evaluation process.
4. For this reason the function object needs to be (mostly) state-free.

I need a way to pass information from the function object to the
filter object in a thread-safe way. Specifically, I want to collect
information about when the sign of the function changes at a
particular point. As the function evaluates, I am free to collect this
kind of information the globalDataStruct, but I do not see how to pass
this information on because everything is declared const (a GOOD thing
for thread safety).

So, in the FDSH, how does one pass information the function object
collects from iteration to iteration?

Brady