MPS: Area scanners

["Gerd Möllmann" <gerd.moellmann@gmail.com>]

I remember now why I thought tht scan_bc would work they way I thought,
so that I could compute a suitable scan end and so on. I read in the MPS
docs this:

  type mps_area_scan_t

  Warning: Area scanning functions are subject to the same set of
  restrictions as format scanning functions, described under Cautions.

And Cautions links to a long list containing

  7.3. Cautions

  The MPS guarantees that format methods have exclusive access to the
  object for the duration of the call. This guarantee may entail
  suspending arbitrary threads. The methods that manipulate the object
  must not perform any sort of inter-thread locking or communication.

etc.

Question is of course now, what is with the exclusive access for area
scanning functions? Is that point a member of the "set of restrictions"?

I can't answer that ATM. Maybe someone else can?