Title: Message
Looking at the substance of this proposed issue, it seems to be proposing
a rather different model from the existing one. Surely the existing model
is that, until a scope exits, anything that it has done but that will need
unwinding in the event of fault has to be coped with by the fault handler; after
the scope has exited, it is the responsibility of that scope's compensation
handler.
There
will be cases where some more sophisticated pattern might seem more convenient -
if scope B does operation b1, then b2, then b3, all directly in B, then the
fault handler may need to know if b2 has been done to work out if it must undo
it. The solution of course is to put the operations each in its own scope, in
which case B can leave it to the default fault handler to undo things backwards,
but only of the things that have finished.
The
issue does raise some questions of what happens if a compensation handler itself
contains a scope.
Peter
-----------------------------------
Chief
Scientist
Choreology Ltd
68 Lombard Street, London EC3V 9LJ, UK
web:
www.choreology.com
mobile: +44 7951 536168
