WindowManager & milti-proc UI

I'm seeking milti-proc UI wisdom.

I am working on a system that started life ~VW2.x, and is now running
in VW7.3.1.  The system was not built with a multi-proc UI in mind,
and we are seeing some odd behavior.

Reading the GUI Devlopers Guide (really, I did) I see in the "Windows
Processes" section of chapter 3 that since 7.1 there are multiple
event queues, one per WindowManager and, by default, one WindowManager
per window.

The manual goes on to say that one can specify whether a new window
will use an existing WindowManager or not using a specific subclass of
WindowManagerUsagePolicy, one of:

 o MakeNewWindowManagerUsagePolicy
 o UseParentWindowManagerUsagePolicy

This is where I start to get confused.

The manual goes on to say that the default policy is
UseParentWindow... , but earlier in the same section I read that the
norm is for each window to have it's own WindowManager unless it is
"closely related".

Looking at our running system with an inspector I see that the windows
each have their own WindowManager (i.e. the >>hash of the
WindowManagers is different).

But this system was not written with the multi-proc UI in mind, and so
does not specify one of the above policies, and so *should* default to
using the parent WindowManager, and so all windows should use the same
WindowManager.

... but they don't.  Confusing.

OK, I go to the top window in the application (the launcher) and
explicitly set the policy to the UseParentWindow...  using the
  

postOpenWith: technique from the manual, just in case that is not
      

really the default after all.  This has no effect.  Each window still
ends up with it's own WindowManager.
  

What you describe should work -- here is what we do


postOpenWith: aBuilder
	builder window windowManager activeControllerProcess
		environmentAt: #WindowManagerUsagePolicy
		put: UseParentWindowManagerUsagePolicy new.

This works for us -- no problem.

We have an additional requirement, we have one control window that runs
in its own process but every window it spawns should run in a single process.
We do that by finding such a window (if one exists), and using its process,
otherwise starting new one -- it was a simple subclass of UseParentWindowManagerUsagePolicy.

So, before I go on a seven year mission to understand all this from
the code in the system, I thought I would seek help from the wise. 
The questions I would very much apreciate answers to are:

o Is there really one event queue per WindowManager, and does that
event queue take *all* events for the respective window(s) (just
checking)?

o Which of the two policies corresponds to windows sharing a WindowManager?

o Which is the default, really?

o Is there some other magic here I should know about to get windows to
share a WindowManager?

Thanks,
     Bruce
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Dennis Smith                        [hidden email]
Cherniak Software Development Corporation       +1 905.771.7011
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