Contract-based synchronization of IP telecommunication services: a case study

Communication middleware, like J2EE and OCCAS, facilitates development and deployment of IP telecommunication services by automating various cross-cutting concerns, such as those related to messaging and security. This middleware is highly concurrent, with threads executing methods that an application programmer writes to carry out the service logic. While the middleware manages life-cycle concerns of threads, the problem of synchronizing them is left to the application programmer. Unfortunately, this synchronization code can be complex and prone to error. Moreover, it can easily obscure the service logic. Our prior work proposed solving these problems using a middleware framework to automatically synchronize concurrent service executions based on declarative synchronization contracts. This paper describes an implementation of our synchronization framework and a case study using it. The case study demonstrates the extent to which contract-based synchronization facilitates refinement of a finite-state design to code and improves design transparency. It also examines the impact on performance of the subject application. A conclusion of the case study is that contract-based synchronization could provide a foundation for automatic generation of IPT services from finite-state designs.