Yongjie Zheng

Enhancing architecture-implementation conformance with change management and support for behavioral mapping

It is essential for software architecture to be consistent with implementation during software development. Existing architecture-implementation mapping approaches are not sufficient due to a variety of reasons, including lack of support for change management and mapping of behavioral architecture specification. A new approach called 1.x-way architecture-implementation mapping is presented in this paper to address these issues. Its contribution includes deep separation of generated and non-generated code, an architecture change model, architecture-based code regeneration, and architecture change notification. The approach is implemented in ArchStudio 4, an Eclipse-based architecture development environment. To evaluate its utility, we refactored the code of ArchStudio, and replayed changes that had been made to ArchStudio in two research projects by redoing them with the developed tool.

MobiGATE: a mobile gateway proxy for the active deployment of transport entities

Using gateway proxies is one important approach to facilitating adaptation across wireless and mobile environments. Importantly, augmented service entities deployed within the gateway proxy residing on the wired network can be composed and deployed to shield mobile clients from the effects of poor network characteristics. The usual approach to the static composition of service entities on the gateway proxy is to have these service entities interact with each other by explicitly invoking procedures on the named interface. The tight coupling of interfaces inhibits the flexible composition and adaptation of the service entities to the dynamic operating characteristics of wireless networks. We present a Mobile GATEway for the active deployment of transport entities or MobiGATE (pronounced as MobiGate) for short. MobiGATE is a mobile middleware framework that supports the robust and flexible composition of transport entities, known as streamlets. The flow of data traffic is subjected to processing by a chain of streamlets. Each streamlet encapsulates a service entity that serves to adapt the flow of traffic across the wireless network. To facilitate the dynamic reconfiguration of the streamlets, we advocate applying the concept of coordination as the unifying approach to composing these transport service entities. Importantly, MobiGATE delineates a clear separation of interdependency parts from the service-specific computational codes of those service entities by using a separate coordination language to describe the coordination among streamlet service entities. To this end, we have defined a compositional language called MobiGATE coordination language (MCL) that provides rich constructs to support the definition of compositions, with constrained type validation and checking.

A classification and rationalization of model-based software development

The use of model-based software development is increasingly popular due to recent advancements in modeling technology. Numerous approaches exist; this paper seeks to organize and characterize them. In particular, important terminological confusion, challenges, and recurring techniques of model-based software development are identified and rationalized. New perspectives are provided on some fundamental issues, such as the distinctions between model-driven development and architecture-centric development, code generation, and metamodeling. On the basis of this discussion, we opine that architecture-centric development and domain-specific model-driven development are the two most promising branches of model-based software development. Achieving a positive future will require, however, specific advances in software modeling, code generation, and model-code consistency management.

MobiGATE: a mobile computing middleware for the active deployment of transport services

The use of gateway proxies is one important approach to facilitating adaptation across wireless and mobile environments. Importantly, augmented service entities deployed within the gateway proxy residing on the wired network can be composed and deployed to shield mobile clients from the effects of poor network characteristics. The usual approach to the static composition of service entities on the gateway proxy is to have these service entities interact with each other by explicitly invoking procedures on the named interface, but such a tight coupling of interfaces inhibits the flexible composition and adaptation of the service entities to the dynamic operating characteristics of wireless networks. In this paper, we present a mobile gateway for the active deployment of transport entities or, for short, MobiGATE (pronounced Mobi-Gate). MobiGATE is a mobile middleware framework that supports the robust and flexible composition of transport entities, known as streamlets. The flow of data traffic is subjected to processing by a chain of streamlets. Each streamlet encapsulates a service entity that adapts the flow of traffic across the wireless network. To facilitate the dynamic reconfiguration of the streamlets, we advocate applying the concept of coordination as the unifying approach to composing these transport service entities. Importantly, MobiGATE delineates a clear separation of interdependent parts from the service-specific computational codes of those service entities. It does this by using a separate coordination language, called MobiGATE coordination language (MCL), to describe the coordination among streamlet service entities. The complete design, implementation, and evaluation of the MobiGATE system are presented in this paper. Initial experimental results validate the flexibility of the coordination approach in promoting separation-of-concern in the reconfiguration of services, while achieving low computation and delay overheads.

1.x-Way architecture-implementation mapping

A new architecture-implementation mapping approach, 1.x-way mapping, is presented to address architecture-implementation conformance. It targets maintaining conformance of structure and behavior, providing a solution to architecture changes, and protecting architecture-prescribed code from being manually changed. Technologies developed in this work include deep separation of generated and non-generated code, an architecture change model, architecture-based code regeneration, and architecture change notification.

Architecture-centric derivation of products in a software product line

It is essential to architecture-centric product line development that product line architecture can be used to drive activities specific to product line development, such as product derivation. This requires a mechanism that can automatically derive the architecture and code of a product instance from the customization of product line architecture. In this paper, we analyze the insufficiency of two existing solutions in this area and present an architecture-centric approach that meets the requirement. The approach can support product line differences in platforms and functions, and generate both product line code and product code. It is based on a product line implementation mechanism that combines a code generation and separation pattern with an architecture-based code annotation technique. We have implemented the approach, and finished a preliminary evaluation with a chat application.

MCL: a MobiGATE coordination language for highly adaptive and reconfigurable mobile middleware

The use of middleware is one important approach in facilitating adaptation across wireless and mobile environments, where augmented service entities are composed and deployed to shield mobile clients from the effects of dynamic network characteristics. The MobiGate Coordination Language (MCL) system provides a language‐based approach to the building of mobile applications running in an adaptive middleware, MobiGATE. The concept of the separation of concerns forms the underlying and unifying principle in the provision of the adaptive composition of services. Specifically, a coordination language, MCL, is designed to provide rich constructs supporting the definition of compositions, with constrained type validation and checking. In particular, MCL is formalized by means of the design of a semantic model based on the Z language, which can be used to analyze architectural descriptions and detect possible composition errors such as feedback loops and open circuit problems. Copyright

Mapping Features to Source Code through Product Line Architecture: Traceability and Conformance

Existing software product line approaches often develop and evolve product line features, architecture, and source code independently, which makes it difficult to manage the relationship and conformance between these artifacts. This paper presents a novel approach using the architecture as a pivot to address this problem. It consists of a modeling mechanism that integrates features specification into an architectural model, and an architecture-implementation mapping mechanism that combines code generation with annotation processing. The approach can trace a product line feature to the architecture and source code, and automatically update the architecture and source code to maintain their conformance when feature changes occur. We implemented an Eclipse-based toolset to support the approach, and conducted a case study with the Apache Solr open-source system. The result shows that our approach is both applicable and capable to support the development and evolution of real-world variations of a software system.

Taming changes With 1.x-Way architecture-implementation mapping

A new approach is presented to maintain the conformance between software architecture and code in the presence of changes to both artifacts. Its novel features include suppression of mistaken changes of architecture-prescribed code, explicit recording of architecture changes, and automatic mapping of specific kinds of architecture changes to code in specific ways. In particular, a new code separation mechanism is presented to decouple architecture-prescribed code from user-defined details. It is supported by three important technologies developed in this study to manage architecture changes, including an architecture change model, architecture-based code regeneration, and architecture change notification. The approach is implemented and integrated in ArchStudio, an Eclipse-based architecture development environment.

Coordinated Composition of Services for Adaptive Mobile Middleware

The use of middleware is one important approach to facilitating adaptation across wireless and mobile environments, where augmented service entities are composed and deployed to shield mobile clients from the effects of dynamic network characteristics. The MCL system provides a language-based approach to the building of mobile applications running in an adaptive middleware, MobiGATE. In particular, MCL is formalized by means of the design and development of a semantic model based on Z language, which can be used to analyze architectural descriptions and detect possible composition errors like feedback loops. To verify the semantic model and its ability to provide runtime checking of composition, we have developed and implemented a Java tool to demonstrate how Z semantic models are mapped into computational structures to provide on-the-fly verifications.