[omniORB] ORBscanGranularity == shutdown time?

[Roloff, Craig A]

Why is there a relationship between ORBscanGranularity (SG) and the
shutdown time?  It appears when shutdown (1) is executed that it
takes somewhat less than SG seconds to complete.  Here is a table
of SG vs shutdown times (in seconds) for a particular applicaton:

SG   Shutdown
--   --------
60      49
30      18
10       9
 2       1

The traces all start and end alike.  Namely,

start
=====
omniORB: Preparing to shutdown ORB.
omniORB: Destroying POA(RootPOA).
omniORB: Deactivating all POA(RootPOA)'s objects.
omniORB: Waiting for requests to complete on POA(RootPOA).
omniORB: Requests on POA(RootPOA) completed.
omniORB: Etherealising POA(RootPOA)'s objects.
omniORB: Stopping serving incoming endpoints.
omniORB: giopServer waits for completion of rendezvousers and workers

end
===
omniORB: throw giopStream::CommFailure from giopStream.cc:828(0,NO,COMM_FAILURE_UnMarshalArguments)
omniORB: Server connection refcount = 1
omniORB: giopServer back from waiting.
omniORB: Destruction of POA(RootPOA) complete.
omniORB: Shutting-down all incoming endpoints.
omniORB: TCP endpoint shut down.
omniORB: Server connection refcount = 0
omniORB: Server close connection from giop:tcp:136.240.18.23:49994
... (lots of "Object table entry root<n> (dead) deleted." lines)
omniORB: 755 object references present at ORB shutdown.
omniORB: ORB shutdown is complete.
omniORB: ORB not destroyed; no final clean-up.

And sandwiched in between start and end are:

60 seconds
==========
omniORB: AsyncInvoker: thread id = 1 has exited. Total threads = 3
omniORB: Scan for idle connections (1071170465,764629000)
omniORB: Scavenger reduce idle count for strand 400cbcc0 to 1
omniORB: Scavenger reduce idle count for strand 40427000 to 2
omniORB: Scan for idle connections done (1071170465,764629000).

30 seconds
==========
omniORB: AsyncInvoker: thread id = 1 has exited. Total threads = 3

10 seconds
==========
omniORB: Scan for idle connections (1071170962,329684000)
omniORB: Scavenger reduce idle count for strand 400cbcc0 to 11
omniORB: Scavenger reduce idle count for strand 40427000 to 16
omniORB: Scan for idle connections done (1071170962,329684000).

2 seconds
=========
<nothing>