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Research Collection School Of Computing and Information Systems

Model Check

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Event Analytics, Jin Song Dong, Jun Sun, Yang Liu, Yuan-Fang Li Sep 2014

Event Analytics, Jin Song Dong, Jun Sun, Yang Liu, Yuan-Fang Li

Research Collection School Of Computing and Information Systems

The process analysis toolkit (PAT) integrates the expressiveness of state, event, time, and probability-based languages with the power of model checking. PAT is a self-contained reasoning system for system specification, simulation, and verification. PAT currently supports a wide range of 12 different expressive modeling languages with many application domains and has attracted thousands of registered users from hundreds of organizations. In this invited talk, we will present the PAT system and its vision on “Event Analytics” (EA) which is beyond “Data Analytics”. The EA research is based on applying model checking to event planning, scheduling, prediction, strategy analysis and decision …


Gpu Accelerated Counterexample Generation In Ltl Model Checking, Zhimin Wu, Yang Liu, Yun Liang, Jun Sun May 2014

Gpu Accelerated Counterexample Generation In Ltl Model Checking, Zhimin Wu, Yang Liu, Yun Liang, Jun Sun

Research Collection School Of Computing and Information Systems

Strongly Connected Component (SCC) based searching is one of the most popular LTL model checking algorithms. When the SCCs are huge, the counterexample generation process can be time-consuming, especially when dealing with fairness assumptions. In this work, we propose a GPU accelerated counterexample generation algorithm, which improves the performance by parallelizing the Breadth First Search (BFS) used in the counterexample generation. BFS work is irregular, which means it is hard to allocate resources and may suffer from imbalanced load. We make use of the features of latest CUDA Compute Architecture-NVIDIA Kepler GK110 to achieve the dynamic parallelism and memory hierarchy …


Scc-Based Improved Reachability Analysis For Markov Decision Processes, Lin Gui, Jun Sun, Songzheng Song, Yang Liu, Jin Song Dong May 2014

Scc-Based Improved Reachability Analysis For Markov Decision Processes, Lin Gui, Jun Sun, Songzheng Song, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

Markov decision processes (MDPs) are extensively used to model systems with both probabilistic and nondeterministic behavior. The problem of calculating the probability of reaching certain system states (hereafter reachability analysis) is central to the MDP-based system analysis. It is known that existing approaches on reachability analysis for MDPs are often inefficient when a given MDP contains a large number of states and loops, especially with the existence of multiple probability distributions. In this work, we propose a method to eliminate strongly connected components (SCCs) in an MDP using a divide-and-conquer algorithm, and actively remove redundant probability distributions in the MDP …


Towards Formal Modelling And Verification Of Pervasive Computing Systems, Yan Liu, Xian Zhang, Yang Liu, Jin Song Dong, Jun Sun, Jit Biswas, Mounir Mokhtari Jan 2014

Towards Formal Modelling And Verification Of Pervasive Computing Systems, Yan Liu, Xian Zhang, Yang Liu, Jin Song Dong, Jun Sun, Jit Biswas, Mounir Mokhtari

Research Collection School Of Computing and Information Systems

Smart systems equipped with emerging pervasive computing technologies enable people with limitations to live in their homes independently. However, lack of guarantees for correctness prevent such system to be widely used. Analysing the system with regard to correctness requirements is a challenging task due to the complexity of the system and its various unpredictable faults. In this work, we propose to use formal methods to analyse pervasive computing (PvC) systems. Firstly, a formal modelling framework is proposed to cover the main characteristics of such systems (e.g., context-awareness, concurrent communications, layered architectures). Secondly, we identify the safety requirements (e.g., free of …


Using Contracts To Guide The Search-Based Verification Of Concurrent Programs, Christopher M. Poskitt, Simon Poulding Aug 2013

Using Contracts To Guide The Search-Based Verification Of Concurrent Programs, Christopher M. Poskitt, Simon Poulding

Research Collection School Of Computing and Information Systems

Search-based techniques can be used to identify whether a concurrent program exhibits faults such as race conditions, deadlocks, and starvation: a fitness function is used to guide the search to a region of the program’s state space in which these concurrency faults are more likely occur. In this short paper, we propose that contracts specified by the developer as part of the program’s implementation could be used to provide additional guidance to the search. We sketch an example of how contracts might be used in this way, and outline our plans for investigating this verification approach.


Psyhcos: Parameter Synthesis For Hierarchical Concurrent Real-Time Systems, Étienne André, Yang Liu, Jun Sun, Jin Song Dong, Shang-Wei Lin Jul 2013

Psyhcos: Parameter Synthesis For Hierarchical Concurrent Real-Time Systems, Étienne André, Yang Liu, Jun Sun, Jin Song Dong, Shang-Wei Lin

Research Collection School Of Computing and Information Systems

Real-time systems are often hard to control, due to their complicated structures, quantitative time factors and even unknown delays. We present here PSyHCoS, a tool for analyzing parametric real-time systems specified using the hierarchical modeling language PSTCSP. PSyHCoS supports several algorithms for parameter synthesis and model checking, as well as state space reduction techniques. Its architecture favors reusability in terms of syntax, semantics, and algorithms. It comes with a friendly user interface that can be used to edit, simulate and verify PSTCSP models. Experiments show its efficiency and applicability


A Formal Semantics For Complete Uml State Machines With Communications, Shuang Liu, Yang Liu, Étienne André, Christine Choppy, Jun Sun, Bimlesh Wadhwa, Jin Song Dong Jun 2013

A Formal Semantics For Complete Uml State Machines With Communications, Shuang Liu, Yang Liu, Étienne André, Christine Choppy, Jun Sun, Bimlesh Wadhwa, Jin Song Dong

Research Collection School Of Computing and Information Systems

UML is a widely used notation, and formalizing its semantics is an important issue. Here, we concentrate on formalizing UML state machines, used to express the dynamic behaviour of software systems. We propose a formal operational semantics covering all features of the latest version (2.4.1) of UML state machines specification. We use labelled transition systems as the semantic model, so as to use automatic verification techniques like model checking. Furthermore, our proposed semantics includes synchronous and asynchronous communications between state machines. We implement our approach in USM2C, a model checker supporting editing, simulation and automatic verification of UML state machines. …


Improving Model Checking Stateful Timed Csp With Non-Zenoness Through Clock-Symmetry Reduction, Yuanjie Si, Jun Sun, Yang Liu, Ting Wang Jan 2013

Improving Model Checking Stateful Timed Csp With Non-Zenoness Through Clock-Symmetry Reduction, Yuanjie Si, Jun Sun, Yang Liu, Ting Wang

Research Collection School Of Computing and Information Systems

Real-time system verification must deal with a special notion of ‘fairness’, i.e., clocks must always be able to progress. A system run which prevents clocks from progressing unboundedly is known as Zeno. Zeno runs are infeasible in reality and thus must be pruned during system verification. Though zone abstraction is an effective technique for model checking real-time systems, it is known that zone graphs (e.g., those generated from Timed Automata models) are too abstract to directly infer time progress and hence non-Zenoness. As a result, model checking with non-Zenoness (i.e., existence of a non-Zeno counterexample) based on zone graphs only …


Verification Of Functional And Non-Functional Requirements Of Web Service Composition, Manman Chen, Tian Huat Tan, Jun Sun, Yang Liu, Jun Pang, Xiaohong Li Jan 2013

Verification Of Functional And Non-Functional Requirements Of Web Service Composition, Manman Chen, Tian Huat Tan, Jun Sun, Yang Liu, Jun Pang, Xiaohong Li

Research Collection School Of Computing and Information Systems

Web services have emerged as an important technology nowadays. There are two kinds of requirements that are crucial to web service composition, which are functional and non-functional requirements. Functional requirements focus on functionality of the composed service, e.g., given a booking service, an example of functional requirements is that a flight ticket with price higher than $2000 will never be purchased. Non-functional requirements are concerned with the quality of service (QoS), e.g., an example of the booking service’s non-functional requirements is that the service will respond to the user within 5 seconds. Non-functional requirements are important to web service composition, …


Symbolic Model-Checking Of Stateful Timed Csp Using Bdd And Digitization, Truong Khanh Nguyen, Jun Sun, Yang Liu, Jin Song Dong Dec 2012

Symbolic Model-Checking Of Stateful Timed Csp Using Bdd And Digitization, Truong Khanh Nguyen, Jun Sun, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

Stateful Timed CSP has been recently proposed to model (and verify) hierarchical real-time systems. It is an expressive modeling language which combines data structure/operations, complicated control flows (modeled using compositional process operators adopted from Timed CSP), and real-time requirements like deadline and within. It has been shown that Stateful Timed CSP is equivalent to closed timed automata with silent transitions, which implies that the timing constraints of Stateful Timed CSP can be captured using explicit tick events, through digitization. In order to tackle the state space explosion problem, we develop a BDD-based symbolic model checking approach to verify Stateful Timed …


Automatic Generation Of Provably Correct Embedded Systems, Shang-Wei Lin, Yang Liu, Pao-Ann Hsiung, Jun Sun, Jin Song Dong Nov 2012

Automatic Generation Of Provably Correct Embedded Systems, Shang-Wei Lin, Yang Liu, Pao-Ann Hsiung, Jun Sun, Jin Song Dong

Research Collection School Of Computing and Information Systems

With the demand for new and complicated features, embedded systems are becoming more and more difficult to design and verify. Even if the design of a system is verified, how to guarantee the consistency between the design and its implementation remains a big issue. As a solution, we propose a framework that can help a system designer to model his or her embedded system using a high-level modeling language, verify the design of the system, and automatically generate executable software codes whose behavior semantics are consistent with that of the high-level model. We use two case studies to demonstrate the …


More Anti-Chain Based Refinement Checking, Ting Wang, Songzheng Song, Jun Sun, Yang Liu, Jin Song Dong, Xinyu Wang, Shanping Li Nov 2012

More Anti-Chain Based Refinement Checking, Ting Wang, Songzheng Song, Jun Sun, Yang Liu, Jin Song Dong, Xinyu Wang, Shanping Li

Research Collection School Of Computing and Information Systems

Refinement checking plays an important role in system verification. It establishes properties of an implementation by showing a refinement relationship between the implementation and a specification. Recently, it has been shown that anti-chain based approaches increase the efficiency of trace refinement checking significantly. In this work, we study the problem of adopting anti-chain for stable failures refinement checking, failures-divergence refinement checking and probabilistic refine checking (i.e., a probabilistic implementation against a non-probabilistic specification). We show that the first two problems can be significantly improved, because the state space of the product model may be reduced dramatically. Though applying anti-chain for …


An Analytical And Experimental Comparison Of Csp Extensions And Tools, Ling Shi, Yang Liu, Jun Sun, Jin Song Dong, Gustavo Carvalho Nov 2012

An Analytical And Experimental Comparison Of Csp Extensions And Tools, Ling Shi, Yang Liu, Jun Sun, Jin Song Dong, Gustavo Carvalho

Research Collection School Of Computing and Information Systems

Communicating Sequential Processes (CSP) has been widely applied to modeling and analyzing concurrent systems. There have been considerable efforts on enhancing CSP by taking data and other system aspects into account. For instance, CSP M combines CSP with a functional programming language whereas CSP# integrates high-level CSP-like process operators with low-level procedure code. Little work has been done to systematically compare these CSP extensions, which may have subtle and substantial differences. In this paper, we compare CSP M and CSP# not only on their syntax, but also operational semantics as well as their supporting tools such as FDR, ProB, and …


Automatic Compositional Verification Of Timed Systems, Shang-Wei Lin, Yang Liu, Jun Sun, Jin Song Dong, Étienne André Aug 2012

Automatic Compositional Verification Of Timed Systems, Shang-Wei Lin, Yang Liu, Jun Sun, Jin Song Dong, Étienne André

Research Collection School Of Computing and Information Systems

Specification and verification of real-time systems are important research topics with crucial applications; however, the so-called state space explosion problem often prevents model checking to be used in practice for large systems. In this work, we present a self-contained toolkit to analyze real-time systems specified using event-recording automata (ERAs), which supports system modeling, animated simulation, and fully automatic compositional verification based on learning techniques. Experimental results show that our tool outperforms the state-of-the-art timed model checker.


Improved Bdd-Based Discrete Analysis Of Timed Systems, Truong Khanh Nguyen, Jun Sun, Yang Liu, Jin Song Dong, Yan Liu Aug 2012

Improved Bdd-Based Discrete Analysis Of Timed Systems, Truong Khanh Nguyen, Jun Sun, Yang Liu, Jin Song Dong, Yan Liu

Research Collection School Of Computing and Information Systems

Model checking timed systems through digitization is relatively easy, compared to zone-based approaches. The applicability of digitization, however, is limited mainly for two reasons, i.e., it is only sound for closed timed systems; and clock ticks cause state space explosion. The former is mild as many practical systems are subject to digitization. It has been shown that BDD-based techniques can be used to tackle the latter to some extent. In this work, we significantly improve the existing approaches by keeping the ticks simple in the BDD encoding. Taking advantage of the ‘simple’ nature of clock ticks, we fine-tune the encoding …


Probabilistic Model Checking Multi-Agent Behaviors In Dispersion Games Using Counter Abstraction, Jianye Hao, Songzheng Song, Yang Liu, Jun Sun, Lin Gui, Jin Song Dong, Ho-Fung Leung Jul 2012

Probabilistic Model Checking Multi-Agent Behaviors In Dispersion Games Using Counter Abstraction, Jianye Hao, Songzheng Song, Yang Liu, Jun Sun, Lin Gui, Jin Song Dong, Ho-Fung Leung

Research Collection School Of Computing and Information Systems

Accurate analysis of the stochastic dynamics of multi-agent system is important but challenging. Probabilistic model checking, a formal technique for analysing a system which exhibits stochastic behaviors, can be a natural solution to analyse multi-agent systems. In this paper, we investigate this problem in the context of dispersion games focusing on two strategies: basic simple strategy (BSS) and extended simple strategies (ESS). We model the system using discrete-time Markov chain (DTMC) and reduce the state space of the models by applying counter abstraction technique. Two important properties of the system are considered: convergence and convergence rate. We show that these …


Prts: An Approach For Model Checking Probabilistic Real-Time Hierarchical Systems, Jun Sun, Yang Liu, Songzheng Song, Jin Song Dong, Xiaohong Li Oct 2011

Prts: An Approach For Model Checking Probabilistic Real-Time Hierarchical Systems, Jun Sun, Yang Liu, Songzheng Song, Jin Song Dong, Xiaohong Li

Research Collection School Of Computing and Information Systems

Model Checking real-life systems is always difficult since such systems usually have quantitative timing factors and work in unreliable environment. The combination of real-time and probability in hierarchical systems presents a unique challenge to system modeling and analysis. In this work, we develop an automated approach for verifying probabilistic, real-time, hierarchical systems. Firstly, a modeling language called PRTS is defined, which combines data structures, real-time and probability. Next, a zone-based method is used to build a finite-state abstraction of PRTS models so that probabilistic model checking could be used to calculate the probability of a system satisfying certain property. We …


Verification Of Orchestration Systems Using Compositional Partial Order Reduction, Tian Huat Tan, Yang Liu, Jun Sun, Jin Song Dong Oct 2011

Verification Of Orchestration Systems Using Compositional Partial Order Reduction, Tian Huat Tan, Yang Liu, Jun Sun, Jin Song Dong

Research Collection School Of Computing and Information Systems

Orc is a computation orchestration language which is designed to specify computational services, such as distributed communication and data manipulation, in a concise and elegant way. Four concurrency primitives allow programmers to orchestrate site calls to achieve a goal, while managing timeouts, priorities, and failures. To guarantee the correctness of Orc model, effective verification support is desirable. Orc has a highly concurrent semantics which introduces the problem of state-explosion to search-based verification methods like model checking. In this paper, we present a new method, called Compositional Partial Order Reduction (CPOR), which aims to provide greater state-space reduction than classic partial …


On Combining State Space Reductions With Global Fairness Assumptions, Shao Jie Zhang, Jun Sun, Jun Pang, Yang Liu, Jin Song Dong Jun 2011

On Combining State Space Reductions With Global Fairness Assumptions, Shao Jie Zhang, Jun Sun, Jun Pang, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

Model checking has established itself as an effective system analysis method, as it is capable of proving/dis-proving properties automatically. Its application to practical systems is however limited by state space explosion. Among effective state reduction techniques are symmetry reduction and partial order reduction. Global fairness often plays a vital role in designing self-stabilizing population protocols. It is known that combining fairness and symmetry reduction is nontrivial. In this work, we first show that global fairness, unlike weak/strong fairness, can be combined with symmetry reduction. We extend the PAT model checker with the technique and demonstrate its usability by verifying recently …


Model Checking Hierarchical Probabilistic Systems, Jun Sun, Songzheng Song, Yang Liu Nov 2010

Model Checking Hierarchical Probabilistic Systems, Jun Sun, Songzheng Song, Yang Liu

Research Collection School Of Computing and Information Systems

Probabilistic modeling is important for random distributed algorithms, bio-systems or decision processes. Probabilistic model checking is a systematic way of analyzing finite-state probabilistic models. Existing probabilistic model checkers have been designed for simple systems without hierarchy. In this paper, we extend the PAT toolkit to support probabilistic model checking of hierarchical complex systems. We propose to use PCSP#, a combination of Hoare’s CSP with data and probability, to model such systems. In addition to temporal logic, we allow complex safety properties to be specified by non-probabilistic PCSP# model. Validity of the properties (with probability) is established by refinement checking. Furthermore, …


Model Checking A Model Checker: A Code Contract Combined Approach, Jun Sun, Yang Liu, Bin Cheng Nov 2010

Model Checking A Model Checker: A Code Contract Combined Approach, Jun Sun, Yang Liu, Bin Cheng

Research Collection School Of Computing and Information Systems

Model checkers, like any complex software, are subject to bugs. Unlike ordinary software, model checkers are often used to verify safety critical systems. Their correctness is thus vital. Verifying model checkers is extremely challenging because they are always complicated in logic and highly optimized. In this work, we propose a code contract combined approach for checking model checkers and apply it to a home-grown model checker PAT. In this approach, we firstly embed programming contracts (i.e., pre/post-conditions and invariants) into its source code, which can capture correctness of model checking algorithms, underlying data structures, consistency between different model checking parameters, …


Developing Model Checkers Using Pat, Yang Liu, Jun Sun, Jin Song Dong Sep 2010

Developing Model Checkers Using Pat, Yang Liu, Jun Sun, Jin Song Dong

Research Collection School Of Computing and Information Systems

During the last two decades, model checking has emerged as an effective system analysis technique complementary to simulation and testing. Many model checking algorithms and state space reduction techniques have been proposed. Although it is desirable to have dedicated model checkers for every language (or application domain), implementing one with effective reduction techniques is rather challenging. In this work, we present a generic and extensible framework PAT, which facilitates users to build customized model checkers. PAT provides a library of state-of-art model checking algorithms as well as support for customizing language syntax, semantics, state space reduction techniques, graphic user interfaces, …


Scalable Multi-Core Model Checking Fairness Enhanced Systems, Yang Liu, Jun Sun, Jin Song Dong Dec 2009

Scalable Multi-Core Model Checking Fairness Enhanced Systems, Yang Liu, Jun Sun, Jin Song Dong

Research Collection School Of Computing and Information Systems

Rapid development in hardware industry has brought the prevalence of multi-core systems with shared-memory, which enabled the speedup of various tasks by using parallel algorithms. The Linear Temporal Logic (LTL) model checking problem is one of the difficult problems to be parallelized or scaled up to multi-core. In this work, we propose an on-the-fly parallel model checking algorithm based on the Tarjan’s strongly connected components (SCC) detection algorithm. The approach can be applied to general LTL model checking or with different fairness assumptions. Further, it is orthogonal to state space reduction techniques like partial order reduction. We enhance our PAT …


Verifying Stateful Timed Csp Using Implicit Clocks And Zone Abstraction, Jun Sun, Yang Liu, Jin Song Dong, Xian Zhang Sep 2009

Verifying Stateful Timed Csp Using Implicit Clocks And Zone Abstraction, Jun Sun, Yang Liu, Jin Song Dong, Xian Zhang

Research Collection School Of Computing and Information Systems

In this work, we study model checking of compositional real-time systems. A system is modeled using mutable data variables as well as a compositional timed process. Instead of explicitly manipulating clock variables, a number of compositional timed behavioral patterns are used to capture quantitative timing requirements, e.g. delay, timeout, deadline, timed interrupt, etc. A fully automated abstraction technique is developed to build an abstract finite state machine from the model. The idea is to dynamically create/delete clocks, and maintain/solve a constraint on the clocks. The abstract machine weakly bi-simulates the model and, therefore, LTL model checking or trace-refinement checking are …


Fair Model Checking With Process Counter Abstraction, Jun Sun, Yang Liu, Abhik Roychoudhury, Shanshan Liu, Jin Song Dong Jun 2009

Fair Model Checking With Process Counter Abstraction, Jun Sun, Yang Liu, Abhik Roychoudhury, Shanshan Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

Parameterized systems are characterized by the presence of a large (or even unbounded) number of behaviorally similar processes, and they often appear in distributed/concurrent systems. A common state space abstraction for checking parameterized systems involves not keeping track of process identifiers by grouping behaviorally similar processes. Such an abstraction, while useful, conflicts with the notion of fairness. Because process identifiers are lost in the abstraction, it is difficult to ensure fairness (in terms of progress in executions) among the processes. In this work, we study the problem of fair model checking with process counter abstraction. Even without maintaining the process …


Model Checking Linearizability Via Refinement, Yang Liu, Wei Chen, Yanhong A. Liu, Jun Sun Jun 2009

Model Checking Linearizability Via Refinement, Yang Liu, Wei Chen, Yanhong A. Liu, Jun Sun

Research Collection School Of Computing and Information Systems

Linearizability is an important correctness criterion for implementations of concurrent objects. Automatic checking of linearizability is challenging because it requires checking that 1) all executions of concurrent operations be serializable, and 2) the serialized executions be correct with respect to the sequential semantics. This paper describes a new method to automatically check linearizability based on refinement relations from abstract specifications to concrete implementations. Our method avoids the often difficult task of determining linearization points in implementations, but can also take advantage of linearization points if they are given. The method exploits model checking of finite state systems specified as concurrent …


Pat: Towards Flexible Verification Under Fairness, Jun Sun, Yang Liu, Jin Song Dong, Jun Pang Feb 2009

Pat: Towards Flexible Verification Under Fairness, Jun Sun, Yang Liu, Jin Song Dong, Jun Pang

Research Collection School Of Computing and Information Systems

Recent development on distributed systems has shown that a variety of fairness constraints (some of which are only recently defined) play vital roles in designing self-stabilizing population protocols. Current practice of system analysis is, however, deficient under fairness. In this work, we present PAT, a toolkit for flexible and efficient system analysis under fairness. A unified algorithm is proposed to model check systems with a variety of fairness effectively in two different settings. Empirical evaluation shows that PAT complements existing model checkers in terms of fairness. We report that previously unknown bugs have been revealed using PAT against systems functioning …


Specifying And Verifying Sensor Networks: An Experiment Of Formal Methods, Jin Song Dong, Jing Sun, Jun Sun, Kenji Taguchi, Xian Zhang Oct 2008

Specifying And Verifying Sensor Networks: An Experiment Of Formal Methods, Jin Song Dong, Jing Sun, Jun Sun, Kenji Taguchi, Xian Zhang

Research Collection School Of Computing and Information Systems

With the development of sensor technology and electronic miniaturization, wireless sensor networks have shown a wide range of promising applications as well as challenges. Early stage sensor network analysis is critical, which allows us to reveal design errors before sensor deployment. Due to their distinguishable features, system specification and verification of sensor networks are highly non-trivial tasks. On the other hand, numerous formal theories and analysis tools have been developed in formal methods community, which may offer a systematic method for formal analysis of sensor networks. This paper presents our attempt on applying formal methods to sensor network specification/verification. An …


Specifying And Verifying Event-Based Fairness Enhanced Systems, Jun Sun, Yang Liu, Jin Song Dong, Hai H. Wang Oct 2008

Specifying And Verifying Event-Based Fairness Enhanced Systems, Jun Sun, Yang Liu, Jin Song Dong, Hai H. Wang

Research Collection School Of Computing and Information Systems

Liveness/Fairness plays an important role in software specification, verification and development. Existing event-based compositional models are safety-centric. In this paper, we describe a framework for systematically specifying and verifying event-based systems under fairness assumptions. We introduce different event annotations to associate fairness constraints with individual events. Fairness annotated events can be used to embed liveness/fairness assumptions in event-based models flexibly and naturally. We show that state-of-the-art verification algorithms can be extended to verify models under fairness assumptions, with little computational overhead. We further improve the algorithm by other model checking techniques like partial order reduction. A toolset named Pat has …


Model Checking Csp Revisited: Introducing A Process Analysis Toolkit, Jun Sun, Yang Liu, Jin Song Dong Oct 2008

Model Checking Csp Revisited: Introducing A Process Analysis Toolkit, Jun Sun, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

FDR, initially introduced decades ago, is the de facto analyzer for Communicating Sequential Processes (CSP). Model checking techniques have been evolved rapidly since then. This paper describes PAT, i.e., a process analysis toolkit which complements FDR in several aspects. PAT is designed to analyze event-based compositional system models specified using CSP as well as shared variables and asynchronous message passing. It supports automated refinement checking, model checking of LTL extended with events, etc. In this paper, we highlight how partial order reduction is applied to improve refinement checking in PAT. Experiment results show that PAT outperforms FDR in some cases.