We present an Incremental State Saving technique for which the state saving calls are inserted automatically by directly editing the application executable. This method has the advantage of being easy to use since it ...
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We present an Incremental State Saving technique for which the state saving calls are inserted automatically by directly editing the application executable. This method has the advantage of being easy to use since it is fully automatic, and has good performance since it adds overhead only where state is being modified. Since the editing happens on executable code, the method is independent of the compiler, and allows third party libraries to be used. None of the previous incremental state saving methods have both of these features. We find that it is beneficial to use Automatic Incremental State Saving if less than 15% of the state is modified in each event as compared to copy state saving. This technique allows us to efficiently parallelize existing simulations, and makes Time Warp more accessible to non-Time Warp experts.
The proceedings contain 45 papers. The topics discussed include: use case maps for attributing behavior to system architecture;modeling real-time distributed software systems;the integration of real-time applications ...
ISBN:
(纸本)0818675152
The proceedings contain 45 papers. The topics discussed include: use case maps for attributing behavior to system architecture;modeling real-time distributed software systems;the integration of real-time applications into the global command and control system;implementing distributed real-time control systems in a functional programming language;modeling and simulation in reactive systems;entity-life modeling in a distributed environment;an environment for incremental development of distributed extensible asynchronous real-time systems;development and validation of network clock measurement techniques;inter- and intra-processor synchronizations in multiprocessor real-time kernel;and behavior analysis of parallel, real-time and embedded sytems for monitoring and optimizing industrial processes.
The event horizon is a very important concept that applies to both parallel and sequential discrete-event simulations. By exploiting the event horizon, parallelsimulations can processes events optimistically in a ris...
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The event horizon is a very important concept that applies to both parallel and sequential discrete-event simulations. By exploiting the event horizon, parallelsimulations can processes events optimistically in a risk-free manner (i.e., without requiring antimessages) using adaptable 'breathing' time cycles with variable time widths. Additionally, by exploiting the event horizon, one can significantly reduce the overhead of event list management that is common to virtually every discrete-event simulation. This paper is a continuation of work previously reported at PADS94. In that report, a complete mathematical formulation of the event horizon was derived under equilibrium conditions using the hold model. Various forms of the beta density function were consequently used to verify the predicted results of the analytic model. This second report describes how the concept of the event horizon can also be applied to event list management. By exploiting the event horizon, the performance of several priority queue data structures are improved including: linked lists, various binary trees, and heaps. A somewhat detailed description of these modified data structures along with other relevant background information is provided for completeness. Performance results for each priority queue data structure is presented.
For the performability evaluation of complex soft realtime systems simulation often remains the only feasible method. simulation experiments tend to be very time consuming if rare events have to be considered. This pa...
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The paper presents a modeling and simulation method to evaluate the performance of distributed computer control systems (DCCSs). Task response time, resource utilization, and network delay are considered as performanc...
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The single-disk, D-head model of parallel I/O was introduced by Agarwal and Vitter to analyze algorithms for problem instances that are too large to fit in primary memory. Subsequently Vitter and Shriver proposed a mo...
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ISBN:
(纸本)9780897918138
The single-disk, D-head model of parallel I/O was introduced by Agarwal and Vitter to analyze algorithms for problem instances that are too large to fit in primary memory. Subsequently Vitter and Shriver proposed a more realistic model in which the disk space is partitioned into D disks, with a single head per disk. To date, each problem for which there is a known optimal algorithm for both models has the same asymptotic bounds on both models. Therefore, it has been unknown whether the models are equivalent or whether the single-disk model is strictly more powerful. In this paper we provide evidence that the single-disk model is strictly more powerful. We prove a lower bound on any general simulation of the single-disk model on the multi-disk model and establish randomized and deterministic upper bounds. Let N be the problem size and let T be the number of parallel I/Os required by a program on the single-disk model. Then any simulation of this program on the multi-disk model will require Ω (Tlog(N/D)/log log(N/D)) parallel I/Os. This lower bound holds even if replication is allowed in the multi-disk model. We also show an O (log D/log log D) randomized upper bound and an O (log D(log log D)2) deterministic upper bound. These results exploit an interesting analogy between the disk models and the PRAM and DCM models of parallel computation.
ITL and Tempura are used for respectively the formal specification and simulation of a large scale system, namely the general purpose multi threaded dataflow processor EP/3. The paper shows that this processor can be ...
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Mathematical simulation of self organizing chaotic processes in networks with speed independent processes by means of the asynchronous method of chaotic relaxations with delay using the Monte-Carlo method is considere...
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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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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. In this paper, we 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 support 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.
Incremental, parallel development of distributed real-time systems is difficult. Architectural techniques and software tools developed at the Jet Propulsion Laboratory's (JPL's) Flight System Testbed (FST) mak...
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