Cyclic dependencies in modular performance analysis

Abstract:In the military field, multi-agent simulation (MAS) plays an important role in studying wars statistically. For a military simulation system, which involves large-scale entities and generates a very large number of interactions during the runtime, the issue of how to improve the running efficiency is of great concern for researchers. Current solutions mainly use hybrid simulation to gain fewer updates and synchronizations, where some important continuous models are maintained implicitly to keep the system dynamics, and partial resynchronization (PR) is chosen as the preferable state update mechanism. However, problems, such as resynchronization interval selection and cyclic dependency, remain unsolved in PR, which easily lead to low update efficiency and infinite looping of the state update process. To address these problems, this paper proposes a lookahead behavior model (LBM) to implement a PR-based hybrid simulation. In LBM, a minimal safe time window is used to predict the interactions between implicit models, upon which the resynchronization interval can be efficiently determined. Moreover, the LBM gives an estimated state value in the lookahead process so as to break the state-dependent cycle. The simulation results show that, compared with traditional mechanisms, LBM requires fewer updates and synchronizations.

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“…Cyclic dependency [49] can be described as direct or indirect dependencies between two or more modules when they perform their own functions.…”

Section: Cyclic Dependencymentioning

confidence: 99%

A Lookahead Behavior Model for Multi-Agent Hybrid Simulation

Yang

Peng

et al. 2017

Applied Sciences

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“…(e) Long-term rates: In order to construct output curves α {u,l} that approximate the system behavior well also for large time intervals, we need to make sure that we follow the long-term event output rate. By long-term rate of an arrival curve α we mean the inverse of the limit lim Δ→∞ α(Δ) Δ , which always exists as detailed in [12]. The largest δ u i and the smallest δ l i of any valid upper and lower output staircase function, respectively, denote upper and lower bounds on the long-term rate of the output.…”

Section: Output Interfacementioning

confidence: 99%

Analytic real-time analysis and timed automata: a hybrid methodology for the performance analysis of embedded real-time systems

Lampka

Perathoner

Thiele

2010

Des Autom Embed Syst

Self Cite

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This paper presents a compositional and hybrid approach for the performance analysis of distributed real-time systems. The developed methodology abstracts system components by either flow-oriented and purely analytic descriptions or by state-based models in the form of timed automata. The interaction among the heterogeneous components is modeled by streams of discrete events. In total this yields a hybrid framework for the compositional analysis of embedded systems. It supplements contemporary techniques for the following reasons: (a) state space explosion as intrinsic to formal verification is limited to the level of isolated components; (b) computed performance metrics such as buffer sizes, delays and utilization rates are not overly pessimistic, because coarse-grained analytic models are used only for components that conform to the stateless model of computation. For demonstrating the usefulness of the presented ideas, a corresponding tool-chain has been implemented. It is used to investigate the performance of a two-staged computing system, where one stage exhibits state-dependent behavior that is only coarsely coverable by a purely analytic and stateless component abstraction. Finally, experiments are performed to ascertain the scalability and the accuracy of the proposed approach.

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“…An example of a fixed-priority scheduler, re-using the GPC component defined in Figure 3 page 3, with two tasks is written as: node fp_scheduler ( in_res : i n t ; in1 , in2 : i n t ) returns ( out1 , out2 : i n t ; out_res : i n t ) var remaining : i n t ; l e t out1 , remaining = gpc ( in1 , in_res ); out2 , out_res = gpc ( in2 , remaining ); t e l The connection from a component to another can be done in two ways. Either we compute the arrival curves for the output of the first component, and we apply the usual modular analysis for RTC (using a fixpoint computation for circular dependencies [17]), or we actually connect the Lustre nodes to do a global computation.…”

Section: B Composing Power-aware Componentsmentioning

confidence: 99%

ac2lus: Bringing SMT-Solving and Abstract Interpretation Techniques to Real-Time Calculus through the Synchronous Language Lustre

Altisen

Moy²

2010

2010 22nd Euromicro Conference on Real-Time Systems

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Abstract-We present an approach to connect the Real-Time Calculus (RTC) method to the synchronous data-flow language Lustre, and its associated tool-chain, allowing the use of techniques like SMT-solving and abstract interpretation which were not previously available for use with RTC. The approach is supported by a tool called ac2lus. It allows to model the system to be analyzed as general Lustre programs with inputs specified by arrival curves; the tool can compute output arrival curves or evaluate upper and lower bounds on any variable of the components, like buffer sizes. Compared to existing approaches to connect RTC to other formalisms, we believe that the use of Lustre, a real programming language, and the synchronous hypothesis make the task easier to write models, and we show that it allows a great flexibility of the tool itself, with many variants to fine-tune the performances.

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Cyclic dependencies in modular performance analysis

Cited by 44 publications

References 7 publications

A Lookahead Behavior Model for Multi-Agent Hybrid Simulation

A Lookahead Behavior Model for Multi-Agent Hybrid Simulation

Analytic real-time analysis and timed automata: a hybrid methodology for the performance analysis of embedded real-time systems

ac2lus: Bringing SMT-Solving and Abstract Interpretation Techniques to Real-Time Calculus through the Synchronous Language Lustre

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