WORDS 2002: 7th International Workshop on Object-Oriented Real-Time Dependable Systems

Conference Information
Name: WORDS 2002: 7th International Workshop on Object-Oriented Real-Time Dependable Systems
Location: San Diego, United States

Latest articles from this conference

Scheduling algorithms play a significant role in the design of real-time Computing systems. Rate-monotonic, deadline-monotonic, relative urgency and least laxity algorithms are the most commonly used algorithms. It is already proved that rate-monotonic (RM) is an optimal fixed priority algorithm and many practical safety verification algorithms are developed [1, 2, 3, 4]. Here, an improvement to lower bound processor load factor for some special cases is presented. We then established a modified version of the rate-monotonic algorithm named delayed rate-monotonic (DRM) algorithm that uses two ready states, instead of one. For two special cases we showed full processor utilization is possible. Two algorithms, namely DRM and RM, are then compared and it is shown that there are many systems that are safe with DRM algorithm but are unsafe with RM algorithm. Also, for a set of randomly generated systems number of task preemptions for the two algorithms is compared. It is concluded that DRM is very promising and it has the potential to be considered for future research.
S. Ohara, F. Tsunoda, H. Maezawa, M. Hui, T. Wang, , Raymond Paul
To assure the quality of software by running test cases and evaluating the results is one of the difficult parts of the entire software development project. The difficulty usually comes from the lack of appropriate supporting tools and the complexity of the software. In the past ad hoc supporting tools were made for each project and test results were usually not used across projects. This conventional way of test and evaluation (T & E) is time consuming, and the most important decision "When is this software ready to ship?" is left to the engineers depending on his/her experience. Our objective is to build a knowledge-based T & E environment such that tests cases, test results, object snapshots and other information are accumulated in a database. These longitudinal data can be automatically tracked and analyzed to provide decision support information. As a result, test results can be reviewed repeatedly and software quality can be assured by analyzing these data from various perspectives. This paper describes the details of object testing in our testing environment.
P. Puschner, A. Burns
The Worst-Case Execution-Time Analysis (WCET Analysis) of program code for modern processors is a highly complex task. First, it involves path analysis, to identify and describe the possible execution paths through the code. Second, it models the worst-case timing of possible paths on the target hardware, where the characterization of the timing of sophisticated hardware features (e.g., instruction pipelines, caches, parallel execution units) and their interferences are non-trivial.This paper presents a programming paradigm that takes the complexity from WCET analysis. Program code written according to this paradigm only has a single execution path. Writing single-path code makes path analysis and thus WCET analysis trivial. The WCET of the single path is obtained by executing the code (necessarily on that single path) and logging the duration of this execution. To demonstrate that the single-path approach provides a universal solution to the WCET-analysis problem, the paper shows how every WCET-analyzable piece of code can be translated into single-path code.
R. Friedman, E. Hadad
This paper presents a lightweight CORBA fault-tolerance service called FTS. The service is based on standard portable features of CORBA, and in that respect is fully CORBA compliant, but does not follow the FT-CORBA specifications in areas where the authors felt the latter interfered with their other design goals. The service features a unique architecture, based on a new type of an object adaptor, called Group Object Adaptor (GOA). The service is portable, interoperable, and aims for simplicity and high-performance request processing. Moreover, the service supports network partitions, some aspects of non-deterministic processing, and mixing ORBs of different vendors in the same fault-tolerance infrastructure. The paper also presents an analysis of the differences between the service design and FT-CORBA, with the hope of stimulating a discussion about future improvements to the FT-CORBA standard.
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