We investigate conservative parallel discrete event simulations for logical circuits on shared-memory multiprocessors. For a first estimation of the possible speedup, we extend the critical path analysis technique by ...
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ISBN:
(纸本)9780818675393
We investigate conservative parallel discrete event simulations for logical circuits on shared-memory multiprocessors. For a first estimation of the possible speedup, we extend the critical path analysis technique by partitioning strategies. To incorporate overhead due to the management of data structures, we use a simulation on an ideal parallel machine (PRAM). This simulation can be directly executed on the SB-PRAM prototype, yielding both an implementation and a basis for data structure optimizations. One of the major tools to achieve these is the SB-PRAM's hardware support for parallel prefix operations. Our reimplementation of the PTHOR program on the SB-PRAM yields substantially higher speedups than before.
When used to simulate manufacturing systems, most existing parallelsimulation languages cannot easily implement some features of those systems, such as the scheduling rules of a machine or the sharing of operators by...
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ISBN:
(纸本)9780769511047
When used to simulate manufacturing systems, most existing parallelsimulation languages cannot easily implement some features of those systems, such as the scheduling rules of a machine or the sharing of operators by multiple machines. This paper presents the design and implementation of a parallel Object-oriented Manufacturing simulation Language, called POMSim. A POMSim simulation is developed by using the concept of classes (entity-types) and inheritance to support iterative design of efficient simulation models. POMSim completely hides all the details of parallelsimulation, and provides simple and direct constructs to efficiently model the scheduling rules in manufacturing simulation. It also provides asynchronous method invocation and synchronous function call. Pomsim libraries predefine a set of basic classes for manufacturing simulation, each of which represents a particular component in the physical manufacturing system.
Performance of Time Warp simulation systems are often measured on exclusively available parallel computing resources. In distributed systems exclusive use is normally not feasible. Instead, due to the multi-tasking op...
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ISBN:
(纸本)9780818671203
Performance of Time Warp simulation systems are often measured on exclusively available parallel computing resources. In distributed systems exclusive use is normally not feasible. Instead, due to the multi-tasking operating systems, many users share the workstations and their availability for parallelsimulation purposes varies extensively. Time Warp has been found to be very sensitive to variations in available processing power. This paper presents two methods for a Time Warp VLSI simulation system to reduce the negative effect of a non-ideal environment on the execution of parallelsimulations. A dynamic load balancing algorithm which adapts to the change of available processing power is presented. This mechanism, together with a multi-cluster partitioning technique significantly improve the performance of Time Warp based simulation systems on heterogeneous computing resource.
The Hierarchical Tool HIT is a software tool for hierarchical modeling and performance evaluation of discrete event systems. Besides analytical and numerical solution techniques HIT provides the evaluation of models b...
ISBN:
(纸本)9780818679650
The Hierarchical Tool HIT is a software tool for hierarchical modeling and performance evaluation of discrete event systems. Besides analytical and numerical solution techniques HIT provides the evaluation of models by sequential simulation. Here we present concepts for optimistic distributedsimulation of HIT-models by partitioning them with respect to subhierarchies. The main goals of the concept being presented are the preservation of model structure even in lower levels of the realization (e.g. use of the process view of simulation throughout all levels of abstraction) and distribution transparency on the modeling level (homogeneous model specification for all solution techniques).
A network of workstations (NOW) has become an important distributed platform for large-scale scientific computations. A practical NOW system is heterogeneous and nondedicated, where computing power varies among the wo...
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ISBN:
(纸本)0818672358
A network of workstations (NOW) has become an important distributed platform for large-scale scientific computations. A practical NOW system is heterogeneous and nondedicated, where computing power varies among the workstations and multiple jobs may interact with each other during execution. I present the design and implementation of a simulation system for a nondedicated heterogeneous NOW. This simulator provides many options to users to specify and quantify system architectures, network heterogeneity and time-sharing factors, such as speeds of different processors, memory organizations, network topology, communication structures, and workload distributions. The simulator also supports execution of message-passing parallel programs written in C and the PVM library. The software structure of the simulator is well-modularized and highly extensible, which makes it easy to integrate other existing processor, memory and network simulators.
ECATNets are a kind of high-level net/data model, combining the strengths of Petri nets with those of abstract data types, used for modeling parallel and distributed systems. Their most distinctive feature is that the...
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ECATNets are a kind of high-level net/data model, combining the strengths of Petri nets with those of abstract data types, used for modeling parallel and distributed systems. Their most distinctive feature is that their semantics is defined in terms of rewriting logics, thus allowing us to analyse the built models by prototyping. However a major drawback of this approach is that the achieved prototypes suffer from a lack of efficiency during their execution. The objective of this paper is to palliate this lack by introducing the concept of hidden sorted ECATNets, a combination of net/object model allowing to "hide" (object) internal states, and then to get more rapid prototypes.< >
In this paper we study message flow processes in distributed simulators of open queueing networks. We develop and study queueing models for distributed simulators with maximum lookahead sequencing. We characterize the...
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ISBN:
(纸本)9780818675393
In this paper we study message flow processes in distributed simulators of open queueing networks. We develop and study queueing models for distributed simulators with maximum lookahead sequencing. We characterize the "external'' arrival process, and the message feedback process in the simulator of a simple queueing network with feedback. We show that a certain "natural'' modelling construct for the arrival process is exactly correct, whereas an ``obvious'' model for the feedback process is wrong; we then show how to develop the correct model. Our analysis throws light on the stability of distributed simulators of queueing networks with feedback. We show how the stability of such simulators depends on the parameters of the queueing network.
In this paper we address the problem of efficiently performing parallel discrete-event simulation in the case that events elaboration is dependent of other processes' local states. We propose a parallelsimulation...
ISBN:
(纸本)9780818679650
In this paper we address the problem of efficiently performing parallel discrete-event simulation in the case that events elaboration is dependent of other processes' local states. We propose a parallelsimulation policy, called State Query Time Warp (SQTW), based on the Time Warp mechanism. We present experiments performed by means of a SQTW-based parallel simulator on a T-800 transputer machine for solving performance models based on state-dependent routing queueing network models. The experiments are used for assessing overheads and efficiency involved by SQTW; results show that high efficiency is achievable, and surprisingly reveal SQTW is able to globally reduce rollback overheads with respect to corresponding Time Warp simulations.
A simulation-oriented language can significantly enhance the usability of parallel Discrete Event simulation (PDES) by hiding the complexities of the synchronization protocol used to ensure that events are processed i...
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ISBN:
(纸本)9780818675393
A simulation-oriented language can significantly enhance the usability of parallel Discrete Event simulation (PDES) by hiding the complexities of the synchronization protocol used to ensure that events are processed in the correct order. The higher-level interface presented to the user by such a language also allows optimizations to be performed that are difficult and cumbersome with current parallel simulators, such as granularity control. APOSTLE is a new high-level simulation-oriented language for PDES, and in this paper we report that the APOSTLE granularity control mechanism reduced simulation run-times by as much as 80%. We also report that APOSTLE achieved a parallel speed-up of around 9 on 16 processors relative to its optimized sequential implementation and a parallel speed-up of around 6 on 16 processors relative to MODSIM II. Overall, we believe that the widespread success of PDES can only be achieved using a simulation-oriented language, and that APOSTLE has made a significant contribution towards this goal.
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