Feng Chen

Bio: Feng Chen is an academic researcher from University of Science and Technology of China. The author has contributed to research in topics: Parametric statistics & Runtime verification. The author has an hindex of 31, co-authored 63 publications receiving 2976 citations. Previous affiliations of Feng Chen include Peking University & University of Illinois at Urbana–Champaign.

Mop: an efficient and generic runtime verification framework

Abstract: Monitoring-Oriented Programming (MOP1) [21, 18, 22, 19] is a formal framework for software development and analysis, in which the developer specifies desired properties using definable specification formalisms, along with code to execute when properties are violated or validated. The MOP framework automatically generates monitors from the specified properties and then integrates them together with the user-defined code into the original system. The previous design of MOP only allowed specifications without parameters, so it could not be used to state and monitor safety properties referring to two or more related objects. In this paper we propose a parametric specification formalism-independent extension of MOP, together with an implementation of JavaMOP that supports parameters. In our current implementation, parametric specifications are translated into AspectJ code and then weaved into the application using off-the-shelf AspectJ compilers; hence, MOP specifications can be seen as formal or logical aspects. Our JavaMOP implementation was extensively evaluated on two benchmarks, Dacapo [14] and Tracematches [8], showing that runtime verification in general and MOP in particular are feasible. In some of the examples, millions of monitor instances are generated, each observing a set of related objects. To keep the runtime overhead of monitoring and event observation low, we devised and implemented a decentralized indexing optimization. Less than 8% of the experiments showed more than 10% runtime overhead; in most cases our tool generates monitoring code as efficient as the hand-optimized code. Despite its genericity, JavaMOP is empirically shown to be more efficient than runtime verification systems specialized and optimized for particular specification formalisms. Many property violations were detected during our experiments; some of them are benign, others indicate defects in programs. Many of these are subtle and hard to find by ordinary testing.

An overview of the MOP runtime verification framework

Abstract: This article gives an overview of the, monitoring oriented programming framework (MOP). In MOP, runtime monitoring is supported and encouraged as a fundamental principle for building reliable systems. Monitors are automatically synthesized from specified properties and are used in conjunction with the original system to check its dynamic behaviors. When a specification is violated or validated at runtime, user-defined actions will be triggered, which can be any code, such as information logging or runtime recovery. Two instances of MOP are presented: JavaMOP (for Java programs) and BusMOP (for monitoring PCI bus traffic). The architecture of MOP is discussed, and an explanation of parametric trace monitoring and its implementation is given. A comprehensive evaluation of JavaMOP attests to its efficiency, especially in comparison with similar systems. The implementation of BusMOP is discussed in detail. In general, BusMOP imposes no runtime overhead on the system it is monitoring.

Java-MOP: a monitoring oriented programming environment for java

Abstract: A Java-based tool-supported software development and analysis framework is presented, where monitoring is a foundational principle. Expressive requirements specification formalisms can be included into the framework via logic plug-ins, allowing one to refer not only to the current state, but also to both past and future states.

Java-MOP: A monitoring oriented programming environment for java

Abstract: A Java-based tool-supported software development and analysis framework is presented, where monitoring is a foundational principle. Expressive requirements specification formalisms can be included into the framework via logic plug-ins, allowing one to refer not only to the current state, but also to both past and future states.

jPredictor: a predictive runtime analysis tool for java

Abstract: jPredictor is a tool for detecting concurrency errors in Java programs. The Java program is instrumented to emit property-relevant events at runtime and then executed. The resulting execution trace is collected and analyzed by Predictor, which extracts a causality relation sliced using static analysis and refined with lock-atomicity information. The resulting abstract model, a hybrid of a partial order and atomic blocks, is then exhaustively analyzed against the property and errors with counter-examples are reported to the user. Thus, jPredictor can "predict" errors that did not happen in the observed execution, but which could have happened under a different thread scheduling. The analysis technique employed in jPredictor is fully automatic, generic (works for any trace property), sound (produces no false alarms) but it is incomplete may miss errors). Two common types of errors are investigated in this paper: dataraces and atomicity violations. Experiments show that jPredictor is precise (in its predictions), effective and efficient. After the code producing them was executed only once, jPredictor found all the errors reported by other tools. It also found errors missed by other tools, including static race detectors, as well as unknown errors in popular systems like Tomcat and the Apache FTP server.

An overview of AspectJ

Abstract: Aspect] is a simple and practical aspect-oriented extension to Java With just a few new constructs, AspectJ provides support for modular implementation of a range of crosscutting concerns. In AspectJ's dynamic join point model, join points are well-defined points in the execution of the program; pointcuts are collections of join points; advice are special method-like constructs that can be attached to pointcuts; and aspects are modular units of crosscutting implementation, comprising pointcuts, advice, and ordinary Java member declarations. AspectJ code is compiled into standard Java bytecode. Simple extensions to existing Java development environments make it possible to browse the crosscutting structure of aspects in the same kind of way as one browses the inheritance structure of classes. Several examples show that AspectJ is powerful, and that programs written using it are easy to understand.

Tools and Algorithms for the Construction and Analysis of Systems. Proc. TACAS 2009

Abstract: ing WS1S Systems to Verify Parameterized Networks . . . . . . . . . . . . 188 Kai Baukus, Saddek Bensalem, Yassine Lakhnech and Karsten Stahl FMona: A Tool for Expressing Validation Techniques over Infinite State Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 J.-P. Bodeveix and M. Filali Transitive Closures of Regular Relations for Verifying Infinite-State Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Bengt Jonsson and Marcus Nilsson Diagnostic and Test Generation Using Static Analysis to Improve Automatic Test Generation . . . . . . . . . . . . . 235 Marius Bozga, Jean-Claude Fernandez and Lucian Ghirvu Efficient Diagnostic Generation for Boolean Equation Systems . . . . . . . . . . . . 251 Radu Mateescu Efficient Model-Checking Compositional State Space Generation with Partial Order Reductions for Asynchronous Communicating Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 Jean-Pierre Krimm and Laurent Mounier Checking for CFFD-Preorder with Tester Processes . . . . . . . . . . . . . . . . . . . . . . . 283 Juhana Helovuo and Antti Valmari Fair Bisimulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 Thomas A. Henzinger and Sriram K. Rajamani Integrating Low Level Symmetries into Reachability Analysis . . . . . . . . . . . . . 315 Karsten Schmidt Model-Checking Tools Model Checking Support for the ASM High-Level Language . . . . . . . . . . . . . . 331 Giuseppe Del Castillo and Kirsten Winter Table of

Runtime Verification for LTL and TLTL

Abstract: This article studies runtime verification of properties expressed either in lineartime temporal logic (LTL) or timed lineartime temporal logic (TLTL). It classifies runtime verification in identifying its distinguishing features to model checking and testing, respectively. It introduces a three-valued semantics (with truth values true, false, inconclusive) as an adequate interpretation as to whether a partial observation of a running system meets an LTL or TLTL property.For LTL, a conceptually simple monitor generation procedure is given, which is optimal in two respects: First, the size of the generated deterministic monitor is minimal, and, second, the monitor identifies a continuously monitored trace as either satisfying or falsifying a property as early as possible. The feasibility of the developed methodology is demontrated using a collection of real-world temporal logic specifications. Moreover, the presented approach is related to the properties monitorable in general and is compared to existing concepts in the literature. It is shown that the set of monitorable properties does not only encompass the safety and cosafety properties but is strictly larger.For TLTL, the same road map is followed by first defining a three-valued semantics. The corresponding construction of a timed monitor is more involved, yet, as shown, possible.