The object is initially passive, and is stored in the object store as an instance of the class OutputObjectState
.
When required by an application, the object is automatically activated by reading it from the store using a read_committed
operation and is then converted from an InputObjectState
instance into a fully-fledged object by the restore_state
operation of the object.
When the application has finished with the object, it is deactivated by converting it back into an OutputObjectState
instance using the save_state
operation, and is then stored back into the object store as a shadow copy using write_uncommitted
. This shadow copy can be committed, overwriting the previous version, using the commit_state
operation. The existence of shadow copies is normally hidden from the programmer by the transaction system. Object deactivation normally only occurs when the top-level transaction within which the object was activated commits