OTS11 — Failure recovery in Additional Structuring Mechanisms for OTS

The current specification has the necessary hooks for recreating the
distributed activity tree in the event of failures, but the text does not
give an implementers view of what to do. For example, when using
interposition, it is somehow necessary for a SubordinateSignalSet to
remember who (ActivityCoordinator) it was enlisted with so that, upon
failure and recovery, it could enquire as to the status of the activity.
Now, since a SubordinateSignalSet is also a SignalSet, there is a
set_activity_coordinator method that the enroller of the
SubordinateSignalSet could use to pass the reference to it. The
SubordinateSignalSet can then persist this information when (and if) it is
necessary during the protocol. When it recovers, because all IORs are
required to be persistent, it will be able to contact the coordinator and
find out the status.

Some text like the above would be very useful in the spec.