DynaComm: The Extension of CommUnity to Support Dynamic Reconfiguration

Abstract

<p> Architecture Description Languages were developed to support the abstract level of software structuring that is the subject matter of software architecture. CommUnity is an ADL built on co-ordination principles and a categorical framework to support the composition of specifications of components to form the system's specification. However, an important problem of CommUnity is the lack of support for specifying the system's architectural changes in both the set of components and the connections between them.</p> <p> This thesis presents DynaComm, an extension of CommUnity to support hierarchical design and dynamic reconfiguration of component based systems. Several new language constructs are introduced into DynaComm: subsystems are coarse grained components which are considered as the basic unit for the construction of systems, connectors encapsulate a component interaction pattern that can organize the possibly complicated interactions between the components of a subsystem. We also propose the idea of interface manager to solve the problem of incorrectly synchronized actions in CommUnity, and the concept of population manager to manage the live instances of components in a subsystem, through which we can model potentially complicated dynamic reconfigurations in a system.</p> <p> To use the semantics of CommUnity in defining the semantics of DynaComm, a "normalization" technique is introduced to transform the parameterized (indexed) actions into "normal" actions of CommUnity and reduce the specification of connectors and subsystems to flat CommUnity designs, so that we can derive the system's semantics in a certain state.</p> <p> Two illustrative examples, fault-tolerant dynamic client-server and vending machine systems, are also given to show the usage of DynaComm in modeling complicated and dynamic systems.</p>