2,603 research outputs found
Interacting via the Heap in the Presence of Recursion
Almost all modern imperative programming languages include operations for
dynamically manipulating the heap, for example by allocating and deallocating
objects, and by updating reference fields. In the presence of recursive
procedures and local variables the interactions of a program with the heap can
become rather complex, as an unbounded number of objects can be allocated
either on the call stack using local variables, or, anonymously, on the heap
using reference fields. As such a static analysis is, in general, undecidable.
In this paper we study the verification of recursive programs with unbounded
allocation of objects, in a simple imperative language for heap manipulation.
We present an improved semantics for this language, using an abstraction that
is precise. For any program with a bounded visible heap, meaning that the
number of objects reachable from variables at any point of execution is
bounded, this abstraction is a finitary representation of its behaviour, even
though an unbounded number of objects can appear in the state. As a
consequence, for such programs model checking is decidable.
Finally we introduce a specification language for temporal properties of the
heap, and discuss model checking these properties against heap-manipulating
programs.Comment: In Proceedings ICE 2012, arXiv:1212.345
Automatic Verification of Erlang-Style Concurrency
This paper presents an approach to verify safety properties of Erlang-style,
higher-order concurrent programs automatically. Inspired by Core Erlang, we
introduce Lambda-Actor, a prototypical functional language with
pattern-matching algebraic data types, augmented with process creation and
asynchronous message-passing primitives. We formalise an abstract model of
Lambda-Actor programs called Actor Communicating System (ACS) which has a
natural interpretation as a vector addition system, for which some verification
problems are decidable. We give a parametric abstract interpretation framework
for Lambda-Actor and use it to build a polytime computable, flow-based,
abstract semantics of Lambda-Actor programs, which we then use to bootstrap the
ACS construction, thus deriving a more accurate abstract model of the input
program. We have constructed Soter, a tool implementation of the verification
method, thereby obtaining the first fully-automatic, infinite-state model
checker for a core fragment of Erlang. We find that in practice our abstraction
technique is accurate enough to verify an interesting range of safety
properties. Though the ACS coverability problem is Expspace-complete, Soter can
analyse these verification problems surprisingly efficiently.Comment: 12 pages plus appendix, 4 figures, 1 table. The tool is available at
http://mjolnir.cs.ox.ac.uk/soter
Preface of the special issue on Model Checking of Software
Software Model Checking consists of a broad collection of techniques to tackle the complexity and the diversity in the use of software in safety-critical systems. The contributions in this special issue address some of the core problems in software model checking. The articles are based on papers selected from the 2013 SPIN Symposium on Model Checking of Software, an annual forum for practitioners and researchers interested in symbolic and state space-based techniques for the validation and analysis of software systems.The final publication is available at Springer via https://doi.org/10.1007/s10009-016-0414-5.(VLID)138711
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