Aspect] is a simple and practical aspect-oriented extension to Java With just a few new constructs, AspectJ provides support for modular implementation of a range of crosscutting concerns. In AspectJ's dynamic join point model, join points are well-defined points in the execution of the program; pointcuts are collections of join points; advice are special method-like constructs that can be attached to pointcuts; and aspects are modular units of crosscutting implementation, comprising pointcuts, advice, and ordinary Java member declarations. AspectJ code is compiled into standard Java bytecode. Simple extensions to existing Java development environments make it possible to browse the crosscutting structure of aspects in the same kind of way as one browses the inheritance structure of classes. Several examples show that AspectJ is powerful, and that programs written using it are easy to understand.

An overview of AspectJ

A number of library based parallel and sequential network simulators have been designed. The paper describes a library, called GloMoSim (Global Mobile system Simulator), for parallel simulation of wireless networks. GloMoSim has been designed to be extensible and composable: the communication protocol stack for wireless networks is divided into a set of layers, each with its own API. Models of protocols at one layer interact with those at a lower (or higher) layer only via these APIs. The modular implementation enables consistent comparison of multiple protocols at a given layer. The parallel implementation of GloMoSim can be executed using a variety of conservative synchronization protocols, which include the null message and conditional event algorithms. The paper describes the GloMoSim library, addresses a number of issues relevant to its parallelization, and presents a set of experimental results on the IBM 9076 SP, a distributed memory multicomputer. These experiments use models constructed from the library modules.

GloMoSim: a library for parallel simulation of large-scale wireless networks

[서평]「Component Software」 - Beyond Object-Oriented Programming -

http://www.eis.mdx.ac.uk/staffpages/juanaugusto/CookAJ2009.pdf

Review: Ambient intelligence: Technologies, applications, and opportunities

The Internet of Things (IoT) envisages a future in which digital and physical things or objects (e.g., smartphones, TVs, cars) can be connected by means of suitable information and communication technologies, to enable a range of applications and services. The IoT’s characteristics, including an ultra-large-scale network of things, device and network level heterogeneity, and large numbers of events generated spontaneously by these things, will make development of the diverse applications and services a very challenging task. In general, middleware can ease a development process by integrating heterogeneous computing and communications devices, and supporting interoperability within the diverse applications and services. Recently, there have been a number of proposals for IoT middleware. These proposals mostly addressed wireless sensor networks (WSNs), a key component of IoT, but do not consider RF identification (RFID), machine-to-machine (M2M) communications, and supervisory control and data acquisition (SCADA), other three core elements in the IoT vision. In this paper, we outline a set of requirements for IoT middleware, and present a comprehensive review of the existing middleware solutions against those requirements. In addition, open research issues, challenges, and future research directions are highlighted.

/pdf/middleware-for-internet-of-things-a-survey-5b3i33k9fm.pdf

Middleware for Internet of Things: A Survey

Testing system software (such as protocol stacks or file systems) often is a tedious and error-prone process. The reason for this is that such software is very complex and often not designed to be tested. This paper presents DiPS, a component framework, which forces to develop testable software, and DiPSUnit, a JUnit extension, to test DiPS units in a uniform way. Although non-trivial test support is provided, using DiPSUnit keeps testing simple and intuitive thanks to the DiPS approach.

DiPS: Filling the Gap between System Software and Testing

In this paper we present a mechanism for serializing the execution-state of a distributed Java application that is implemented on a conventional Object Request Broker (ORB) architecture such as Java Remote Method Invocation (RMI). To support capturing and reestablishment of distributed execution-state, we developed a byte code transformer that adds this functionality to a Java application by extracting execution-state from the application code. An important benefit of the serialization mechanism is its portability. It can transparently be integrated into any legacy Java application. Furthermore, it does require no modifications to the Java Virtual Machine (JVM) or to the underlying ORB. The serialization mechanism can serve many purposes such as migrating execution-state over the network or storing it on disk. In particular, we describe the implementation of a prototype for repartitioning distributed Java applications at runtime. Proper partitioning of distributed objects over the different machines is critical to the global performance of the distributed application. Methods for partitioning exist, and employ a graph-based model of the application being partitioned. Our serialization mechanism enables then applying these methods at any point in an ongoing distributed computation.

https://lirias.kuleuven.be/bitstream/123456789/124604/1/2003NetObjectDays.pdf

Serialization of distributed execution-state in Java

Transparent object migration in adaptive parallel applications

In this paper, we discuss a method of composing a system from components with anonymous dependencies. We make observations based on our experience with defining and implementing a composition mechanism for layered architectures. We propose a manner of specifying component descriptions by means of semantic-unaware properties, an application-domain independent formalism for describing the client-specific configuration requests in terms of desired properties, and a composition algorithm that works well in these conditions.

Automatic Composition of Systems from Components with Anonymous Dependencies

Networks of workstations become more and more appropriate for parallel applications. XENOOPS is an advanced environment for parallel software, running on such networks, as well as on multicomputers. The XENOOPS load balancing framework meets the requirements of the regular users of a time-sharing distributed system, and of the HPCN users who prefer to exploit multiple processors as if these processors have been reserved for one particular application. On the one hand, a parallel application can dynamically obtain and effectively exploit workstations as these turn idle. On the other hand, workstation owners transparently claim their device when accessing it on the console. In both cases, the parallel application transparently reorganises itself while maintaining a balanced work load distribution. Consequently, dynamic load balancing also becomes important for regular applications, which would not require dynamic reallocation in a space-sharing system.

Pierre Verbaeten

Papers

DiPS: Filling the Gap between System Software and Testing

Serialization of distributed execution-state in Java

Transparent object migration in adaptive parallel applications

Automatic Composition of Systems from Components with Anonymous Dependencies

Flexible load balancing software for parallel applications in a time-sharing environment