OTS11 — exception processing during completion in subordinates

The ActivityCoordinator complete_activity operation may raise
ActivityPending
and ChildContextPending exceptions. The conditions under which these
exceptions
are raised should be independent of whether they occur in the root or a
subordinate node. For example, if the a subordinate node had earlier
spawned an
asynchronous thread that was not complete when the subordinate was signaled
for
preCompletion, then the application originator (on the root) should receive
an ActivityPending exception that does not cause the Activity to complete
or
mark is as failed only.
Yet, at the subordinate, the only response that the subordinate
Synchronization
Action can give during preCompletion is an Outcome of preCompletionSuccess
or
preCompletionFailed or an ActionError exception, none of which result in
the desired
behaviour.

Possible solutions are:
1. New exceptions on the Action::process_signal exception that
the root ActivityCoordinator converts to ActivityPending or
ChildContextPending.
CORBA::TRANSIENT could be used if the minor codes were architected.
This is ugly because its specific to the processing of the
Synchronization
SignalSet.
2. New predefined Outcomes for the Synchronization SignalSet that the root
ActivityCoordinator can recognize and convert accordingly. Still a
little
ugly in that the ActivityCoordinator needs to understand the meaning of
an Outcome.

In either case, the Synchronization SignalSet needs to be capable of being
redriven
after returning such an Outcome/Exception.

see above