Object-Oriented Transaction Processing by Priority Ceiling

The object-oriented transaction processing characterized by recursive invocation of method for object is realized by concurrency control which satisfies object-oriented serializability. As the conventional semantic concurrency control is executed by switching subtransactions, the transaction which has arrived subsequently can be partly executed by suspending the precedent transaction which has not been completed, as far as the object-oriented serializability is guaranteed. Despite of allowance of partial execution for the subsequent transaction, the semantic concurrency control faces the left off problem about precedent transactions, which means that the precedent transactions cannot be executed for a long time. This paper presents an object-oriented transaction processing by introducing priority ceiling to resolve the left off problem. Furthermore, to evaluate performance of our proposed method detailed experiments were carried out from various viewpoints. Especially, from experimental results about execution time of transaction, left-off transactions, execution time of transaction, suspended time and waiting time of subtransactions, we obtain detailed consideration of the performance evaluation and show effectiveness of our proposed object-oriented transaction processing by the priority-ceiling.