- with (nPollProcInterfaces < 0) it does the following:
- loop, waiting for some requests to finish
- for each out-of-date interface, check if its associated
requests have now finished (ie, the ready() check).
- if ready() -> call updateInterfaceMatrix()
In contrast to (nPollProcInterfaces > 0) which loops a specified
number of times with several calls to MPI_Test each time, the
(nPollProcInterfaces < 0) variant relies on internal MPI looping
within MPI_Waitsome to progress communication.
The actual dispatch still remains non-deterministic (ie, waiting for
some requests to finish does not mean that any particular interface
is eligible for update, or in any particular order). However, using
Waitsome places the tight looping into the MPI layer, which results
in few calls and eliminates behaviour dependent on the value of
nPollProcInterfaces.
TUT: add polling to windAroundBuildings case (for testing purposes)
1f5cf3958b