[Cbc] MaxNumNodes and active nodes

[Giacomo Nannicini]

Hi,
does someone know how the MaxNumNodes parameter affects the creation
of nodes in Cbc?

Let me explain better. I need to access a list of all nodes which are
still active after the optimization stops because of some limit (nodes
or time).
I thought that I could find such list scanning the tree (
CbcModel::tree_ ) but apparently this is not so.
When the optimization stops on maximum number of nodes, it often tells
me that there are no active nodes in the tree, even though I know that
the optimization has not finished so there has to be some node left to
explore - but I cannot find where this behaviour comes from. I would
expect Cbc to create the nodes after branching anyway, even though
they will not be solved because of the node limit.

Is there some limbo where nodes could exist without being added to the tree?

Thanks!

Giacomo