The SL synchronous language

We present SL, a new programming language of the synchronous reactive family in which hypotheses about signal presence/absence are disallowed. One can decide that a signal is absent during an instant only at the end of this instant, and so reaction to this absence is delayed to the next instant. Sources of causal circularities are avoided, while only weak preemption remains. A structural operational semantics is provided through rewrite rules, and an implementation is described. In addition to directly executing programs, this implementation can also be used to produce automata by symbolic evaluation     

Java threads and SugarCubes

SugarCubes is a set of Java classes which provides a simple and structured approach to concurrency. It offers a powerful and modular communication mechanism based on instantaneously broadcast events. The semantics of SugarCubes code is deterministic and does not depend on arbitrary choices made by the execution platform. SugarCubes gives programmers a sound and fine control over execution; for example, reactive instructions can be preempted in a completely clean way. The paper compares thread‐based programming with SugarCubes programming. It shows that SugarCubes is simpler and more structured than the standard Java threading mechanism. Copyright © 2000 John Wiley & Sons, Ltd.     

FairThreads: mixing cooperative and preemptive threads in C

FairThreads introduces fair threads which are executed in a cooperative way when linked to a scheduler, and in a preemptive way otherwise. Constructs exist for programming the dynamic linking/unlinking of threads during execution. Users can profit from the cooperative scheduling when threads are linked. For example, data only accessed by the threads linked to the same scheduler does not need to be protected by locks. Users can also profit from the preemptive scheduling provided by the operating system (OS) when threads are unlinked, for example to deal with blocking I/Os. In the cooperative context, for the threads linked to the same scheduler, FairThreads make it possible to use broadcast events. Broadcasting is a powerful, abstract, and modular means of communication. Basically, event broadcasting is made possible by the specific way threads are scheduled by the scheduler to which they are linked (the ‘fair’ strategy). FairThreads give a way to deal with some limitations of the OS. Automata are special threads, coded as state machines, which do not need the allocation of a native thread and which have efficient execution. Automata also give a means to deal with the limited number of native threads available when large numbers of concurrent tasks are needed, for example in simulations. Copyright © 2005 John Wiley & Sons, Ltd.     

Kinetics of isothermal phase transformations above and below the peritectic temperature: Phase-field simulations

We present phase-field simulations of isothermal phase transformations in the peritectic system below and above the peritectic temperature. The physical processes involved are of different natures, involving either a triple junction or a liquid-film-migration (LFM) mechanism. Below the peritectic temperature, one of the solid phases steadily grows along the other. Above the peritectic temperature the phase transformation proceeds via the LFM mechanism. To the best of our knowledge, this mechanism has not been discussed in the literature as a generic process of phase transitions in peritectic systems. In addition to the LFM process, we also simulate melting along the solid–solid interface. Finally, we make a simplified linear stability analysis of the liquid film, supporting our simulation results.     

The ESTEREL language

The authors present the basics of the ESTEREL reactive model of synchronous parallel systems. The ESTEREL programming style, based on instantaneous communications and decisions, is illustrated through the example of a mouse handler. The ESTEREL formal semantics is described, and it is shown how programs can be compiled into finite state sequential machines for efficient execution. The implementation is described with the ESTEREL environment, including simulation, and verification and validation tools. Some ESTEREL uses in various contexts are reported     

Phase-field simulations with inhomogeneous elasticity: Comparison with an atomic-scale method and application to superalloys

We present a 2D and 3D phase-field analysis of microstructure evolution in the presence of a lattice misfit and with inhomogeneous elastic constants. The method is first critically compared with a Monte Carlo modeling at the atomic scale. We then apply the phase-field model to the Ni–Al system under external load along a cubic axis. We find that the microstructure becomes anisotropic and that the situation qualitatively differs depending on the sign of the applied stress. The microstructure evolution operates mainly by shape changes and alignments of precipitates, but also by splitting of precipitates initially elongated along directions perpendicular to the stress-induced, elastically favorable directions. The final microstructure is finally qualitatively analyzed in terms of a mean field theory in which the elastic inhomogeneity is embedded into an effective eigenstrain. This analysis leads to a simple formulation which can be used to easily predict the coherent microstructural anisotropy induced by any external loading condition.     

Validation and analysis of the futurebus arbitration protocol: A case study

In this paper, we use perfectly synchronous languages such asEsterel, for modelling Futurebus arbitration protocol. We show that the perfect synchrony aids in the formalization, testing, validating and verifying the protocol. We discuss solutions to the above protocol and show that properties such as mutual exclusion and deadlock-freedom can be established formally. Further, we show how the simulators can be used for testing and validation and can verify an instantiation of the protocol through algebraic tools such as auto/autograph. The work was partially supported by IFCPAR, Indo-French Center for the Promotion of Advanced Research, New Delhi, India.     

The SugarCubes tool box: a reactive Java framework

SugarCubes is a set of Java classes used to implement dynamic, reactive, event-based, parallel systems. SugarCubes can be seen as a low-level basis upon which more complex reactive formalisms can be implemented. It also provides a convenient framework for prototyping experimental extensions to various reactive formalisms. SugarCubes is freely available on the Web. © 1998 John Wiley & Sons, Ltd.