Roberto Vitali

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In this article we address the reshuffle of the design of optimistic simulation kernels in order to fit multi-core/multi-processor machines. This is done by providing a reference optimistic simulation architecture based on the symmetric multi-threaded paradigm, where each simulation kernel instance is allowed to run a dynamically changing set of worker(More)
In this paper we address state recoverability in optimistic simulation systems by presenting an autonomic log/restore architecture. Our proposal is unique in that it jointly provides the following features: (i) log/restore operations are carried out in a completely transparent manner to the application programmer, (ii) the simulation-object state can be(More)
A recent work has presented the design and implementation of a software library, named DyMeLoR, supporting transparent log/restore facilities for optimistic simulation objects with generic memory layout. This library offers the possibility to allocate/deallocate memory chunks via standard API, and performs log/restore of the object state via pack/unpack(More)
In this article we overview the ROme OpTimistic Simu-lator (ROOT-Sim), an open source C/MPI-based simulation package targeted at POSIX systems, which implements general-purpose parallel/distributed simulation environment relying on the optimistic (i.e. rollback based) synchronization paradigm. It offers a very simple programming model based on the classical(More)
Parallel Discrete Event Simulation (PDES) is based on the partitioning of the simulation model into distinct Logical Processes (LPs), each one modeling a portion of the entire system, which are allowed to execute simulation events concurrently. This allows exploiting parallel computing architectures to speedup model execution, and to make very large models(More)
We present the design and implementation of an autonomic state manager (ASM) tailored for integration within optimistic parallel discrete event simulation (PDES) environments based on the C programming language and the executable and linkable format (ELF), and developed for execution on ×86_64 architectures. With ASM, the state of any logical process(More)
Traditionally, Logical Processes (LPs) forming a simulation model store their execution information into disjoint simulations states, forcing events exchange to communicate data between each other. In this work we propose the design and implementation of an extension to the traditional Time Warp (optimistic) synchronization protocol for parallel/distributed(More)
One reason for the success of in-memory (transactional) data grids lies on their ability to fit elasticity requirements imposed by the cloud oriented pay-as-you-go cost model. In fact, by relying on in-memory data maintenance, these platforms can be dynamically resized by simply setting up (or shutting down) instances of so called data cache servers.(More)
In this work we address state recoverability in advanced optimistic simulation systems by proposing an Evolutionary Algorithm to optimize at run-time the parameters associated with state log/restore activities. Optimization takes place by adaptively selecting for each simulation object both (i) the best suited log mode (incremental vs non-incremental) and(More)
In parallel discrete event simulation techniques, the simulation model is partitioned into objects, concurrently executing events on different CPUs and/or multiple CPUCores.In such a context, run-time supports for logical time synchronization across the different simulation objectsplay a central role in determining the effectiveness of the specific parallel(More)