[Click] Information sharing in Click

[Adam M]

Hi folks,

Sorry for the barrage of questions, but I'm trying to field questions
from colleagues/managers around here that I don't know the answer to.
There is concern about the ability for Elements to share information
with each other outside of the standard push/pull processing. Perhaps
it's more clear if I give an example.

In our case, we're considering using Click for simulating a wireless
network. In our simulation, we deal with things like radio transmission
radius, contention of the physical medium, signal quality, etc.

When packets first arrive in the simulation, we'd like to have them
analyzed and some results of that analysis stored somewhere. This
analyzer would likely be an Element, and could either be a pass-through
or we could hook it up using Tee.

Now, the issue is that the results of this early analysis are needed by
numerous downstream Elements. For example, some distant downstream
Element might need to know what our estimate is for signal quality
between two nodes. What I don't understand is how an Element can serve
as an information repository that other Elements can query and get a
response. All of the Click examples I've seen are unidirectional, where
Element A pushes to B, which pushes to C, etc.

I suspect that all this is possible in Click, but at the moment I don't
see how to do it. Could someone please explain?

Thanks again,
Adam