Constructing Weakly Terminating Interface Protocols
This work addresses concurrency issues in component compositions for system designers, but it is incremental as it builds on prior results.
The paper tackles the problem of avoiding deadlocks and livelocks in asynchronous communicating systems by generalizing existing methods to construct weakly terminating interface protocols, making the theory more broadly applicable in practice and embedding it in an open-source tool.
Interfaces play a central role in determining compatible component compositions by prescribing permissible interactions between a service provider (server) and its consumers (clients). The high degree of concurrency in asynchronous communicating systems increases the risk of unintentionally introducing deadlocks and livelocks. The weak termination property serves as a basic sanity check to avoid such problems. It assures that in each reachable state, the system has the option to eventually terminate. This paper generalizes existing results that, by construction, guarantee weakly terminating interface compositions. Our generalizations make the theory applicable more broadly in practice. Starting with an interface specification of a server satisfying certain properties, we show how a class of clients modeling different usage contexts can be derived using a partial mirroring relation. Furthermore, we discuss an embedding of our results in an open-source tool to guide modelers in designing weakly terminating interfaces.