Improving integrity of embedded computers in control

Enhancing Integrity of Embedded Control Systems

Experiences with Dedicated Real-Time Operating Systems

Service-Oriented software has attracted the attention of academia and it is widely applied in Internet of Things because of its advantages of reusability and expansibility. However, regarding service-oriented software, the burden of the development of the exception handling increases and the complexity of the exception handling logic strengthens, owing to the dynamic and uncertain running circumstances and the autonomy and loose-coupling service resources. The focus of this article is a relevant study on the exception handling of service-oriented software. And the analysis of these studies is divided into three parts: the classification of exception in service-oriented software, policy-based exception handling description language and its implementation framework, exception propagation analysis. Through the analysis, the author points out the main problems of the recent studies and the orientation of further researches.

Exception handling in a complex concurrent and distributed system (e.g. one involving cooperating rather than just competing activities) is often a necessary, but a very difficult, task. No widely accepted models or approaches exist in this area. The object-oriented paradigm, for all its structuring benefits, and real-time requirements each add further difficulties to the design and implementation of exception handling in such systems. In this paper, we develop a general structuring framework based on the coordinated atomic (CA) action concept for handling exceptions in an object-oriented distributed system, in which exceptions in both the value and the time domain are taken into account. In particular, we attempt to attack several difficult problems related to real-time system design and error recovery, including action-level timing constraints, time-triggered CA actions, and time-dependent exception handling. The proposed framework is then demonstrated and assessed using an industrial real-time application-the Production Cell III case study.

Although the top-down development paradigm has successfully been applied to master the complexity of large systems, it has not yet been accepted as a useful paradigm for fault tolerant system design. This is mainly due to a problem that is sometimes referred to as the “lazy programmers” paradox. The “lazy programmer” paradox was already present and solved in top-down development methods for non-critical systems. However, the problem has re-appeared in an even more serious variant for critical systems. A few “toy” examples concerning exception handling in an Ada-like language are used to explain and illustrate the paradox. One possible solution to the problem is to use a specification language in which one can express that certain behaviours of a system are preferred over others. This paper proposes deontic logic as such a specification language. Therefore, a short and rather informal introduction to deontic logic is included. A non-trivial example is included to illustrate how deontic logic can be used to solve the “lazy programmer” paradox.

This paper presents a novel implementation of an embedded Java microarchitecture for secure, real-time, and multi-threaded applications. A general-purpose platform is established through the support of modern features of object-oriented languages, such as exception handling, automatic garbage collection and interface types. New techniques have been implemented for specific real-time issues, such as an integrated stack and thread management for fast context switching, concurrent garbage collection for real-time threads and autonomous control flows through preemptive round-robin scheduling.

With the wide-spread using of LinuxOS, the Real-time requirement in certain applications is heighly demanded. So the Xenomai comes up, it has a higher priority than Linux kernel, so it can deal with the tasks which need real-time requirement.In order to set up the real-time Linux based on the ARM platform, the mini2440 development board contained s3c2440 as its MCU is used to set up the real-time operation system. Design and test the performs of the system. The results show that the embeded real-time Linux system based on the Xenomai has the good quality of real-time and can be used in the soft real-time system or the hard real-time system.

Decompilation is a reconstruction of a program in a high-level language from a program in a low-level language. Typical applications of decompilation are software security assessment, malware analysis, error correction and reverse engineering for interoperability. Native code decompilation is traditionally considered in the context of the C programming language. C++ presents new challenges for decompilation, since the rules of translation from C++ to assembly language are far more complex than those of C. In addition, when decompiling a program that was originally written in C++, reconstruction of C++ specific constructs is desired. In this paper we discuss new methods that allow partial recovery of C++ specific language constructs from a low-level code provided that this code was obtained from a C++ compiler. The challenges that arise when decompiling such code are described. These challenges include reconstruction of polymorphic classes, class hierarchies, member functions and exception handling constructs. An approach to decompilation that is used to overcome these challenges is presented. Smart Dec, a native code to C++ decompiler that is being developed by the authors at Select LTD is presented. It reconstructs expressions, function arguments, local and global variables, integral and composite types, loops and compound conditional statements, C++ class hierarchies and exception handling constructs. An empirical study of the decompiler is provided.

Organizations that are geared for success within today's business environments must be capable of rapid and continuous change. Dynamic change is a large and pervasive problem which surfaces within organizational workflows as well as within soft ware engineering, manufacturing, and numerous other domains. Procedural changes, performed in an ad hoc manner, can cause inefficiencies, inconsistencies, and catastrophic breakdowns within organizations. This document is concerned with change, especially dynamic change, to organizational procedures. We explain a taxonomy of change modalities, and present a modeling language for the unambiguous specification of procedural change. This language, call i>ML-DEWS, complements the formal model of dynamic change previously presented by the authors. Issues of exception handling, temporal specification, and participatory change are conveniently handled within the framework presented in this document.

The programming of the interrupt handling mechanisms, process switching primitives, scheduling mechanisms, and synchronization primitives of an operating system for a multiprocessor require both efficient code in order to support the needs of high-performance or real-time applications and careful organization to facilitate maintenance. Although many advantages have been claimed for object-oriented class hierarchical languages and their corresponding design methodologies, the application of these techniques to the design of the primitives within an operating system has not been widely demonstrated.To investigate the role of class hierarchical design in systems programming, the authors have constructed the Choices multiprocessor operating system architecture using the C++ programming language. During the implementation, it was found that many operating system design concerns can be represented advantageously using a class hierarchical approach, including: the separation of mechanism and policy; the organization of an operating system into layers, each of which represents an abstract machine; and the notions of process and exception management. In this paper, we discuss an implementation of the low-level primitives of this system and outline the strategy by which we developed our solution.

For many real-time applications (e.g. command, control, and communications), parallel computers offer a natural computing platform. However, very little attention has been paid to the specification requirements of real-time systems implemented on parallel machines. Towards this end, we propose a specification language PRETSEL (Parallel Real-Time Specification Language). The PRETSEL specification language is based on a traditional two-level view of parallel computing whereby a parallel computation is viewed as a collection of interacting (data) parallel algorithms. This view is naturally reflected in PRETSEL syntax where at the lower level various constructs are provided for the specification of a data-parallel real-time algorithm (data-parallelism). At the upper level another set of constructs is provided to combine such tasks in a variety of way (task-parallelism). Furthermore, the PRETSEL language allows for the specification of performance requirements. PRETSEL is currently being evaluated for real-time avionics applications. We describe the syntax and operational semantics of PRETSEL and establish results relating the functional and the temporal behaviors.

A real-time operating system (RTOS) provides a platform for the design and implementation of a wide range of applications in real-time systems, embedded systems, and mission-critical systems. This paper presents a formal design model for a general RTOS known as RTOS+ that enables a specific target RTOS to be rigorously and efficiently derived in real-world applications. The methodology of a denotational mathematics, Real-Time Process Algebra (RTPA), is described for formally modeling and refining architectures, static behaviors, and dynamic behaviors of RTOS+. The conceptual model of the RTOS+ system is introduced as the initial requirements for the system. The architectural model of RTOS+ is created using RTPA architectural modeling methodologies and refined by a set of Unified Data Models (UDMs). The static behaviors of RTOS+ are specified and refined by a set of Unified Process Models (UPMs). The dynamic behaviors of the RTOS+ system are specified and refined by the real-time process scheduler and system dispatcher. This work is presented in two papers; the conceptual and architectural models of RTOS+ is described in this paper, while the static and dynamic behavioral models of RTOS+ will be elaborated in a forthcoming paper.

Automatic synthesis of SDL from MSC and its applications in forward and reverse engineering

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The tight coupling between system and market operations implies that there are strong interrelationships between system security management and market performance. Therefore, the assurance by the regional transmission organization (<emphasis emphasistype="boldital">RTO</emphasis>) of secure system operations strongly depends on, and directly impacts, electricity markets. Typically, electricity is traded in a sequence of markets that are cleared at different frequencies and with different lead times. In this paper, we focus on the hourly day-ahead markets (<emphasis emphasistype="boldital">DAM</emphasis>s) and their associated real-time markets (<emphasis emphasistype="boldital">RTM</emphasis>s) that clear, typically, every 5 to 10 min. The <emphasis emphasistype="boldital">DAM</emphasis>s' clearing impacts the nature and the extent of the participants' responses to real-time conditions and, therefore, the real-time system operations, which, in turn, impact system security. The basic thrusts of this work are to quantitatively characterize the linkages between the real-time system security and the day-ahead markets as well as to investigate the role of the financial entities in a multi-settlement system. We develop a systematic approach that allows us to quantify the auction surplus attained through the multi-settlement system and evaluate the impacts of the <emphasis emphasistype="boldital">DAM</emphasis>s on market participants' bid/offer surpluses as well as on improving the ability to facilitate real-time secure power system operations. We illustrate the application of the approach on the large-scale ISO-NE multi-settlement system using the historical 2005–2006 data—the system model and the bids/offers submitted—and the actual market clearing methodology. The studies bear out the well known fact that the participation of financial entities leads to the convergence of the <emphasis emphasistype="boldital">DAM</emphasis> and the associated <emphasis emphasistype="boldital">RTM</emphasis> prices. Moreover, these studies also illustrate that such participation leads to improved forecasts of the real-time system operations, and consequently results in improving the assurance of system security. </para>

Towards a temporal coherence management in real-time knowledge-based systems