10,800 research outputs found
Synthesis of Interface Specifications for Java Classes
While a typical software component has a clearly specified (static) interface in terms of the methods and the input/output types they support, information about the correct sequencing of method calls the client must invoke is usually undocumented. In this paper, we propose a novel solution for automatically extracting such temporal specifications for Java classes. Given a Java class, and a safety property such as the exception E should not be raised , the corresponding (dynamic) interface is the most general way of invoking the methods in the class so that the safety property is not violated. Our synthesis method first constructs a symbolic representation of the finite state-transition system obtained from the class using predicate abstraction. Constructing the interface then corresponds to solving a partial-information two-player game on this symbolic graph. We present a sound approach to solve this computationally-hard problem approximately using algorithms for learning finite automata and symbolic model checking for branching-time logics. We describe an implementation of the proposed techniques in the tool JIST- Java Interface Synthesis Tool- and demonstrate that the tool can construct interfaces accurately and efficiently for sample Java2SDK library classes
Active Learning of Points-To Specifications
When analyzing programs, large libraries pose significant challenges to
static points-to analysis. A popular solution is to have a human analyst
provide points-to specifications that summarize relevant behaviors of library
code, which can substantially improve precision and handle missing code such as
native code. We propose ATLAS, a tool that automatically infers points-to
specifications. ATLAS synthesizes unit tests that exercise the library code,
and then infers points-to specifications based on observations from these
executions. ATLAS automatically infers specifications for the Java standard
library, and produces better results for a client static information flow
analysis on a benchmark of 46 Android apps compared to using existing
handwritten specifications
Efficient Monitoring of Parametric Context Free Patterns
Recent developments in runtime verification and monitoring show that parametric regular and temporal logic specifications can be efficiently monitored against large programs. However, these logics reduce to ordinary finite automata, limiting their expressivity. For example, neither can specify structured properties that refer to the call stack of the program. While context-free grammars (CFGs) are expressive and well-understood, existing techniques of monitoring CFGs generate massive runtime overhead in real-life applications. This paper shows for the first time that monitoring parametric CFGs is practical (on the order of 10% or lower for average cases, several times faster than the state-of-the-art). We present a monitor synthesis algorithm for CFGs based on an LR(1) parsing algorithm, modified with stack cloning to account for good prefix matching. In addition, a logic-independent mechanism is introduced to support partial matching, allowing patterns to be checked against fragments of execution traces
Higher-Order Process Modeling: Product-Lining, Variability Modeling and Beyond
We present a graphical and dynamic framework for binding and execution of
business) process models. It is tailored to integrate 1) ad hoc processes
modeled graphically, 2) third party services discovered in the (Inter)net, and
3) (dynamically) synthesized process chains that solve situation-specific
tasks, with the synthesis taking place not only at design time, but also at
runtime. Key to our approach is the introduction of type-safe stacked
second-order execution contexts that allow for higher-order process modeling.
Tamed by our underlying strict service-oriented notion of abstraction, this
approach is tailored also to be used by application experts with little
technical knowledge: users can select, modify, construct and then pass
(component) processes during process execution as if they were data. We
illustrate the impact and essence of our framework along a concrete, realistic
(business) process modeling scenario: the development of Springer's
browser-based Online Conference Service (OCS). The most advanced feature of our
new framework allows one to combine online synthesis with the integration of
the synthesized process into the running application. This ability leads to a
particularly flexible way of implementing self-adaption, and to a particularly
concise and powerful way of achieving variability not only at design time, but
also at runtime.Comment: In Proceedings Festschrift for Dave Schmidt, arXiv:1309.455
A distributed program synthesizer
This paper describes an architecture of a distributed synthesizer for automated program construction. The objective of the synthesizer is to realize the ideas of Structural Synthesis of Programs in a computer network. The synthesizer handles structural specifications stored into Java classes as
meta-interfaces and works on a network using CORBA technology
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