Enterprise distributed real-time and embedded (DRE) systems are increasingly being developed withthe use of component-based software techniques. Unfortunately, commonly used component middleware platforms provide lim...
详细信息
ISBN:
(纸本)9781450306898
Enterprise distributed real-time and embedded (DRE) systems are increasingly being developed withthe use of component-based software techniques. Unfortunately, commonly used component middleware platforms provide limited support for event-based publish/subscribe (pub/sub) mechanisms that meet both quality-of-service (QoS) and configurability requirements of DRE systems. On the other hand, although pub/sub technologies, such as OMG Data Distribution Service (DDS), support a wide range of QoS settings, the level of abstraction they provide make it hard to configure them due to the significant source-level configuration that must be hard-coded at compile time or tailored at run-time using proprietary, ad hoc configuration logic. Moreover, developers of applications using native pub/sub technologies must write large amounts of boilerplate "glue" code to support run-time configuration of QoS properties, which is tedious and error-prone. this paper describes a novel, generative approach that combines the strengths of QoS-enabled pub/sub middleware withcomponent-based middleware technologies. In particular, this paper describes the design and implementation of DDS4CIAO which addresses a number of inherent and accidental complexities in the DDS4CCM standard. DDS4CIAO simplifies the development, deployment, and configuration of component-based DRE systems that leverage DDS's powerful QoS capabilities by provisioning DDS QoS policy settings and simplifying the development of DDS applications.
We describe an experimental object-oriented programming language, ASL2, that supports program development by means of a series of abstraction steps. the language allows immediate object construction, and it is possibl...
详细信息
We describe an experimental object-oriented programming language, ASL2, that supports program development by means of a series of abstraction steps. the language allows immediate object construction, and it is possible to use the constructed objects for concrete problem solving tasks. Classes and class hierarchies can be derived from the objects - via gradual abstraction steps. We introduce two levels of object classification, called weak and strong object classification. Strong object classification relies on conventional classes, whereas weak object classification is looser, and less restrictive. As a central mechanism, weakly classified objects are allowed to borrow methods from each other. ASL2 supports class generalization, as a counterpart to class specialization and inheritance in mainstream object-oriented programming languages. the final abstraction step discussed in this paper is a syntactical abstraction step that derives a source file with a syntactical class form.
Programmers make many changes to the program to eventually find a good solution for a given task. In this course of change, every intermediate development state can of value, when, for example, a promising ideas sudde...
详细信息
Programmers make many changes to the program to eventually find a good solution for a given task. In this course of change, every intermediate development state can of value, when, for example, a promising ideas suddenly turn out inappropriate or the interplay of objects turns out more complex than initially expected before making changes. Programmers would benefit from tool support that provides immediate access to source code and run-time of previous development states of interest. We present IDE extensions, implemented for Squeak/Smalltalk, to preserve, retrieve, and work withthis information. With such tool support, programmers can work without worries because they can rely on tools that help them with whatever their explorations will reveal. they no longer have to follow certain best practices only to avoid undesired consequences of changing code.
Today's Internet is long past static web pages filled with HTML-formatted text sprinkled with an occasional image or animation. We have entered an era of Rich Internet Applications executed locally on Internet cli...
详细信息
Today's Internet is long past static web pages filled with HTML-formatted text sprinkled with an occasional image or animation. We have entered an era of Rich Internet Applications executed locally on Internet clients such as web browsers: games, physics engines, image rendering, photo editing, etc. Yet today's languages used to program Internet clients have limited ability to tap to the computational capabilities of the underlying, often heterogeneous, platforms. In this paper we present how a Domain Specific Language (DSL) can be integrated into ActionScript, one of the most popular scripting languages used to program Internet clients and a close cousin of JavaScript. We demonstrate how our DSL, called ASDP (ActionScript Data Parallel), can be used to enable data parallelism for existing sequential programs. We also present a prototype of a system where data parallel workloads can be executed on either CPU or a GPU, withthe runtime system transparently selecting the best processing unit, depending on the type of workload as well as the architecture and current load of the execution platform. We evaluate performance of our system on a variety of benchmarks, representing different types of workloads: physics, image processing, scientific computing and cryptography.
暂无评论