DPL to express a concurrency control using transaction and object semantics

Abstract

There is a currently considerable interest in advanced transaction processing. Most proposals weaken serializability. The concurrency of transactions executing on shared objects can be enhanced with the use of semantic information about operations type or through user defined semantics called transaction semantic. This paper attempts to unify the two approaches; we present an extended model which exploits both transaction and object semantics to increase concurrency. The approach we adopt is similar to the one used in [Lynch83,Molina83,FO89]. However, our mechanism for specifying allowable interleavings is based on predicate over step types and synchronization operators. It supports concurrent execution of steps and synchronization amongst them. We will integrate this distributed concurrency control policy into a high level language to hide low-level details such as locks, timestamps management and concurrent activities synchronization inside the implementation of the language constructs. We use ANSA computational language DPL (Distributed Programming Language) as a basic language construct. We propose a few DPL extensions to support our model. This model is suitable to express a wide range of synchronization constraints between concurrent activities.

This research was sponsored by «Ministère de la Recherche et de la Technologie Française» under MRE contract.