[Twisted-Python] design pattern advice needed

[Jonathan Vanasco]

I can't wrap my head around this

	FactoryA needs an object from FactoryB
	FactoryB has a finite pool of objects, which can be checked in and  
checked out

I need FactoryA to not-progress until FactoryB is ready to dispense  
an object.

in all of my attempts, i end up with a deferred object in the Factory  
A code.

can anyone point me in the right  direction?