ESBMC is an SMT-based bounded model checker for real-world C programs. Such programs often represent real numbers using the floating-points, most commonly, the IEEE floating-point standard (IEEE 754-2008). Thus, ESBMC now includes a new floating-point arithmetic encoding layer in our SMT backend, that encodes floating-point operations into bit-vector operations. In particular, ESBMC can use off-the-shelf SMT solvers that offer support for bit-vectors only to encode floating-point arithmetic.

ESBMC v6.0 employs a k -induction algorithm to both falsify and prove safety properties in C programs. We have developed a new interval-invariant generator that pre-processes the program, inferring invariants based on intervals and introducing them in the program as assumptions. Our experiments show that ESBMC v6.0 using k -induction can prove up to 7% more programs when the invariant generation is enabled.

ESBMC is a mature, permissively licensed open-source context-bounded model checker for the verification of single- and multi-threaded C programs. It can verify both predefined safety properties (e.g., bounds check, pointer safety, overflow) and user-defined program assertions automatically. ESBMC provides C++ and Python APIs to access internal data structures, allowing inspection and extension at any stage of the verification process. We discuss improvements over previous versions of ESBMC, including the description of new front- and back-ends, IEEE floating-point support, and an improved k-induction algorithm. A demonstration is available at https://www.youtube.com/watch?v=YcJjXHlN1v8 .

Recently, the k-induction algorithm has proven to be a successful approach for both finding bugs and proving correctness. However, since the algorithm is an incremental approach, it might waste resources trying to prove incorrect programs. In this paper, we extend the k-induction algorithm to shorten the number of steps required to find a property violation. We convert the algorithm into a meet-in-the-middle bidirectional search algorithm, using the counterexample produced from over-approximating the program. The main advantage is in the reduction of the state explosion by reducing the maximum required steps from k to ⌊k/2 + 1⌋.

Abstract Grid application developers utilize Commodity Grid (CoG) toolkits to access Globus Grid services. Existing CoG toolkits are language‐specific and have, for example, been developed for Java, Python and the Matlab scripting environment. In this paper we describe MyCoG.NET, a CoG toolkit supporting multi‐language programmability under the Microsoft .NET framework. MyCoG.NET provides a set of classes and APIs to access Globus Grid services from languages supported by the .NET Common Language Runtime. We demonstrate its programmability using FORTRAN, C++, C# and Java, and discuss its performance over LAN and WAN infrastructures. We present a Grid application, in the field of experimental aerodynamics, as a case study to show how MyCoG.NET can be exploited. We demonstrate how scientists and engineers can create and use domain‐specific workflow activity sets for rapid application development using Windows Workflow Foundation. We also show how users can easily extend and customize these activities. Copyright © 2006 John Wiley & Sons, Ltd.

Modern distributed memory parallel computers provide hardware support for the efficient and reliable delivery of interprocessor messages. This facility needs to be accessed by lightweight protocols that do not waste the performance of the underlying hardware; the heavyweight layering techniques traditionally used in distributed systems are wholly inappropriate. A low-level communication interface is therefore presented which exploits modern architectures effectively, while maintaining a good match to existing parallel programming environments. The interface defines mechanisms to access an asynchronous reliable packet delivery service. It permits messaging protocols to be efficiently synthesized by considering the activity at their end-points alone. This arrangement effectively decouples the implementation of protocols from low-level architectural features, and hence aids the portability of parallel programming environments. Furthermore, the interface allows the communication network to be shared by multiple programming paradigms, giving additional flexibility over existing systems.>

Abstract Modern multicomputer components such as the inmos T800 and the Texas Instruments TMS320C40 provide hardware which supports efficient communication between directly connected processors. The paper describes techniques which have been developed to provide efficientglobalcommunications for machines based on these and similar processors. This service is implemented by a packet‐routing kernel adopting a standard, portable communications interface. The design of this kernel is discussed with particular emphasis on the manner in which it guarantees reliable, lightweight, deadlock‐free communication for arbitrary interconnection topologies. The kernel has been developed and tested on transputers. Extensive results on the performance of the router are presented to demonstrate that the substantial advantages associated with its well founded, structured design are not at odds with high efficiency. This router has been used to support several multi‐transputer environments, including a commercially available POSIX‐conformant operating system and a distributed occam environment freed from conventional configuration constraints.

The authors introduce a multiprocessor interconnection network, known as cube-connected Mobius ladders, which has an inherently deadlock-free routing strategy and hence has none of the buffering and computational overhead required by deadlock-avoidance message passing algorithms. The basic network has a diameter phi of 4n-1 for n2/sup n+2 /nodes and has a fixed node degree of 4. The network can be interval routed in two stages and can be represented as a Cayley graph. This is the only practical fixed degree topology of size O(2/sup phi /) which has an inherently deadlock-free routing strategy, making it ideally suited for medium and large sized transputer networks.>