Semantic theories of programs with nested interrupts

In the design of dependable software for embed- ded and real-time operating systems, time analysis is a cru- cial but extremely difficult issue, the challenge of which is exacerbated due to the randomness and nondeterminism of interrupt handling behaviors. Thus research into a theory that integrates interrupt behaviors and time analysis seems to be important and challenging. In this paper, we present a pro- gramming language to describe programs with interrupts that is comprised of two essential parts： main program and inter- rupt handling programs. We also explore a timed operational semantics and a denotational semantics to specify the mean- ings of our language. Furthermore, a strategy of deriving de- notational semantics from the timed operational semantics is provided to demonstrate the soundness of our operational se- mantics by showing the consistency between the derived de- notational semantics and the original denotational semantics.

A Multi-Agent Spatial Logic for Scenario-Based Decision Modeling and Verification in Platoon Systems

To cater for the scenario of coordinated transportation of multiple trucks on the highway,a platoon system for autonomous driving has been extensively explored in the industry.Before such a platoon is deployed,it is necessary to ensure the safety of its driving behavior,whereby each vehicle’s behavior is commanded by the decision-making function whose decision is based on the observed driving scenario.However,there is currently a lack of verification methods to ensure the reliability of the scenario-based decision-making process in the platoon system.In this paper,we focus on the platoon driving scenario,whereby the platoon is composed of intelligent heavy trucks driving on cross-sea highways.We propose a formal modeling and verification approach to provide safety assurance for platoon vehicles’cooperative driving behaviors.The existing Multi-Lane Spatial Logic(MLSL)with a dedicated abstract model can express driving scene spatial properties and prove the safety of multi-lane traffic maneuvers under the single-vehicle perspective.To cater for the platoon system’s multi-vehicle perspective,we modify the existing abstract model and propose a Multi-Agent Spatial Logic(MASL)that extends MLSL by relative orientation and multi-agent observation.We then utilize a timed automata type supporting MASL formulas to model vehicles’decision controllers for platoon driving.Taking the behavior of a human-driven vehicle(HDV)joining the platoon as a case study,we have implemented the model and verified safety properties on the UPPAAL tool to illustrate the viability of our framework.

Preface

As a continuation of previous years’special section on software systems,this special section encourages and promotes research to address challenges from the perspective of software systems.The goal of this special section is to present state-of-the-art and high-quality original research in the area of software systems.This special section is split in two parts,with the first part published earlier in the last issue in November 2021 and the second part published in this current issue.

Preface

As a continuation of previous years1 special section on software systems,this special section encourages and promotes research to address challenges from the perspective of software systems.The goal of this special section is to present state-of-the-art and high-quality original research in the area of software systems.

Algorithms for checking channel passing in web service choreography

Web service choreography describes global mod- els of service interactions among a set of participants. For an interaction to be executed, the participants must know the required channel（s） used in the interaction, otherwise the ex- ecution will get stuck. Since channels are composed dynami- cally, the initial channel set of each participant is often insuf- ficient to meet the requirements. It is the responsibility of the participants to pass required channels owned （known） by one to others. Since service choreography may involve many par- ticipants and complex channel constraints, it is hard for de- signers to specify channel passing in a choreography exactly as required. We address the problem of checking whether a service choreography lacks channels or has redundant chan- nels, and how to automatically generate channel passing based on interaction flows of the service choreography in the case of channel absence. Concretely, we propose a sim- ple language Chorc, a channel interaction sub-language for modeling the channel passing aspect of service choreography. Based on the formal operational semantics of Chore, the algo- rithms for static checking of service choreography and gen- erating channel passing are also studied, and the complexity results of algorithms are discussed. Moreover, some illus- trated service choreography examples are presented to show how to formalize and analyze service choreography with channel passing in Chorc.