Putting time into proof outlines

A logic for reasoning about timing of concurrent programs is presented. The logic is based on proof outlines and can handle maximal parallelism as well as resource-constrained execution environments. The correctness proof for a mutual exclusion protocol that uses execution timings in a subtle way illustrates the logic in action

Comparison of Implicit Path Enumeration and Model Checking Based WCET Analysis

In this paper, we present our new worst-case execution time (WCET) analysis tool for Java processors, supporting both implicit path enumeration (IPET) and model checking based execution time estimation. Even though model checking is significantly more expensive than IPET, it simplifies accurate modeling of pipelines and caches. Experimental results using the UPPAAL model checker indicate that model checking is fast enough for typical tasks in embedded applications, though large loop bounds may lead to long analysis times. To obtain a tool which is able to cope with larger applications, we recommend to use model checking for more important code fragments, and combine it with the IPET approach

On the Use of Context Information for Precise Measurement-Based Execution Time Estimation

The present paper investigates the influence of the execution history on the precision of measurement-based execution time estimates for embedded software. A new approach to timing analysis is presented which was designed to overcome the problems of existing static and dynamic methods. By partitioning the analyzed programs into easily traceable segments and by precisely controlling run-time measurements with on-chip tracing facilities, the new method is able to preserve information about the execution context of measured execution times. After an adequate number of measurements have been taken, this information can be used to precisely estimate the Worst-Case Execution Time of a program without being overly pessimistic

The treatment of non-functional requirements in MIKE

... this paper it is shown how non-functional requirements are modelled in MIKE, an approach to the development of knowledge-based systems. A semi-formal hypermedia-based model is used to describe the results of the elicitation and interpretation of non-functional requirements and their relationships. Non-functional requirements are the driving force behind the decisions taken in the design phase of MIKE. The impact of non-functional requirements on design decisions and interdependencies between design decisions are explicitly recorded in an additional model in MIKE, thus resulting in a rich documentation of the rationale of design decisions and also providing an important contribution to the traceability of these requirement

Worst-case analysis of heap allocations

Abstract. In object oriented languages, dynamic memory allocation is a fundamental concept. When using such a language in hard real-time systems, it becomes important to bound both the worst-case execution time and the worst-case memory consumption. In this paper, we present an analysis to determine the worst-case heap allocations of tasks. The analysis builds upon techniques that are well established for worst-case execution time analysis. The difference is that the cost function is not the execution time of instructions in clock cycles, but the allocation in bytes. In contrast to worst-case execution time analysis, worst-case heap allocation analysis is not processor dependent. However, the cost function depends on the object layout of the runtime system. The analysis is evaluated with several real-time benchmarks to establish the usefulness of the analysis, and to compare the memory consumption of different object layouts.