Java is becoming a viable platform for hard real-time computing. There are production and research real-time Java VMs, as well as applications in both military and civil sector. Technological advances and increased adoption of Real-time Java contrast significantly with the lack of real-time benchmarks. The few benchmarks that exist are either low-level synthetic micro-benchmarks, or benchmarks used internally by companies, making it difficult to independently verify and repeat reported results. This paper presents the CDx (Collision Detector) benchmark suite, an open source application benchmark suite that targets different hard and soft real-time virtual machines. CDx is, at its core, a real-time benchmark with a single periodic task, which implements aircraft collision detection based on simulated radar frames. The benchmark can be configured to use different sets of real-time features and comes with a number of workloads. We describe the architecture of the benchmark and characterize the workload based on input parameters. 1.

Abstract. The Real-time Specification for Java (RTSJ) introduced a range of language features for explicit memory management. While the RTSJ gives programmers fine control over memory use and allows linear allocation and constant time deallocation, the RTSJ relies upon dynamic runtime checks for safety making it unsuitable for safety critical applications. We introduce ScopeJ, a statically typed, multi-threaded, object calculus in which scopes are first class constructs. Scopes reify allocation contexts and provide a safe alternative to automatic memory management. Safety is the result of our use of an ownership type system that enforces a topology on run-time patterns of references. ScopeJ’s type system is novel in that ownership annotations are implicit. This substantially reduces the burden for developers, thus increasing the likelihood of adoption. The notion of implicit ownership is particularly appealing when combined with pluggable type systems, as one can apply different type constraints to components depending on the requirements. In related work we have demonstrated the usefulness of our approach in different applications. 1

The Real-time Specification for Java extends the Java platform

Recently, a plethora of domain-specific component frameworks (DSCF) emerges. Although the current trend emphasizes generative programming methods as cornerstones of software development, they are commonly applied in a costly, ad-hoc fashion. However, we believe that DSCFs share the same subset of concepts and patterns. In this paper we propose two contributions to DSCF development. First, we propose DomainComponents — a high-level abstraction to capture semantics of domain concepts provided by containers, and we identify patterns facilitating their implementation. Second, we develop a generic framework that automatically generates implementation of DomainComponents semantics, thus addressing domain-specific services with one unified approach. To evaluate benefits of our approach we have conducted several case studies that span different domain-specific challenges. 1.

An active library is a software library that can optimise itself to its environment. This report describes semantic lifting, essentially the extraction of high-level semantic information from a low-level process description by means of program analysis, and discusses how we may use this idea to extend the concept of active libraries to include program analysis and verification capabilities. We give two case studies that show our preliminary research results in this field and discuss

Space- and time-predictability are hard to achieve for object-oriented languages with automated dynamic-memory management. Although there has been significant work to design APIs, such as the Real-Time Specification for Java (RTSJ), and to implement garbage collectors to enable real-time performance, quantitative space analysis is still in its infancy. This work presents the integration of a series of compile-time analysis techniques to help predicting quantitative memory usage. In particular, we focus on providing tool-assistance for identifying RTSJ scoped-memory regions, their sizes, and overall memory usage. First, the tool-suite synthesizes a memory organization where regions are associated with methods. Second, it infers their sizes in parametric closedform in terms of relevant program variables. Third, it exhibits a parametric upper-bound on the amount of available free memory required to execute a method. The experiments carried out with a RTSJ benchmark, a real-time aircraft collision detector, show that semi-automatic, tool-assisted generation of scoped-based code is both helpful and doable. key words: Java Real-Time; Scoped-Memory; Quantitative Memory Requirements; Static Analysis 1.

Abstract—For hard real-time systems, static code analysis is needed to derive a safe bound on the worst-case execution time (WCET). Virtually all prior work has focused on the accuracy of WCET analysis without regard to the speed of analysis. The resulting algorithms are often too slow to be integrated into the development cycle, requiring WCET analysis to be postponed until a final verification phase. In this paper we propose interactive WCET analysis as a new method to provide near-instantaneous WCET feedback to the developer during software programming. We show that interactive WCET analysis is feasible using tree-based WCET calculation. The feedback is realized with a plugin for the Java editor jEdit, where the WCET values are back-annotated to the Java source at the statement level. Comparison of this treebased approach with the implicit path enumeration technique (IPET) shows that tree-based analysis scales better with respect to program size and gives similar WCET values. Index Terms—Real time systems, performance analysis, software performance, software reliability, software algorithms, safety I.