Inheritance of Synchronization Constraints in Concurrent Object-Oriented Programming Languages

We analyse how inheritance of synchronization constraints should be supported. The conclusion of our analysis is that inheritance of synchronization constraints should take the form of incrementally more restrictive constraints for derived subclasses. Our conclusion is based on the view that combinations of behavior in object-oriented languages yield subclasses that extend superclass behavior. We give a notation for describing synchronization constraints. In our notation, synchronization constraints can be inherited and aggregated. We present a number of examples that illustrate the fundamental concepts captured by our notation. Synchronization constraints are described as restrictions that apply to invocation of methods. Application of restrictions is pattern-based, which allows the same restriction to apply to multiple methods and multiple restrictions to apply to the same method.