Real-time Analysis of Resource-Constrained Distributed Systems by Simulation-Guided Model Checking

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Real-time Analysis of Resource-Constrained
Distributed Systems by Simulation-Guided Model
Checking

• Gabor Madl (gabe_at_ics.uci.edu),
• Ph.D. Candidate, UC Irvine
• Advisor Nikil Dutt (dutt_at_ics.uci.edu)
• Chancellors Professor, UC Irvine

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Analysis of Embedded Systems
Challenges Model-based Analysis
Simulation-guided Model Checking DREAM
Framework

• Distributed real-time embedded (DRE) systems are
  often reactive and event-driven
• Better latency than in synchronous/time-triggered
  systems
• Easier to implement, no need for global
  synchronization
• Computations are driven by events complex model
• Asynchrony, concurrency, race conditions
• Hard to predict all behaviors
• Have to satisfy multiple constraints
• Real-time, energy consumption, reliability,
  fault-tolerance
• Functional verification, real-time analysis,
  performance estimation are key challenges
• Task execution times, delays, parallelism,
  throughput

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Continuous-time Analysis
Challenges Model-based Analysis
Simulation-guided Model Checking DREAM
Framework

• In DRE systems classic scheduling methods may
  result in scheduling anomalies
• Hard to analyze real-time properties
• In practical event-driven systems, exhaustive
  analysis is often infeasible due to the state
  space explosion problem
• We need methods that can capture continuous-time
  execution intervals, and event-based triggering

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Need to Combine Analysis Methods
Challenges Model-based Analysis
Simulation-guided Model Checking DREAM
Framework

• Static analysis methods
• Often too abstract, resulting in
  conservative/inaccurate results
• Cannot capture dynamic effects
• Simulations
• Can show the presence of an error, never its
  absence
• Ad-hoc, hard to measure coverage
• Limited design space exploration
• Model checking
• State space explosion problem
• No partial results
• Time consuming and costly
• Each method has its advantage and disadvantage

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Model-based Design Analysis
Challenges Model-based Analysis
Simulation-guided Model Checking DREAM
Framework

• We propose a model-based approach for the design
  analysis of embedded systems
• The design flow is driven by the DSM, a
  high-level specification that captures key
  properties
• The DSM is mapped to a formal executable model to
  allow verification and evaluation
• Formal models drive functional verification
• We propose the combination of simulations and
  formal methods for the evaluation of designs

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Domain-Specific Modeling
Challenges Model-based Analysis
Simulation-guided Model Checking DREAM
Framework

• We utilize meta-modeling to specify modeling
  languages
• The modeling language is used for the
  specification and early exploration of design
  alternatives
• Designers work on models that are based on their
  domains of expertise, they do not have to become
  experts in formal methods as well
• We focus on two domains
• DRE systems
• Multi-processor System-on-Chip (MPSoC) designs

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Simulation-Guided Model Checking
Challenges Model-based Analysis
Simulation-guided Model Checking DREAM
Framework

• Parameters for components obtained by simulations
• Utilize model checking and discrete event
  simulations on symbolic models to increase
  coverage

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Architectural Exploration
Challenges Model-based Analysis
Simulation-guided Model Checking DREAM
Framework

• Model checking for the functional verification of
  protocols
• Simulation-guided performance estimation of
  MPSoCs
• Use results as parameters for higher-level models
• Compose methods to improve accuracy, scalability
• Better understanding of interactions between
  components

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DREAM Analysis Framework
Challenges Model-based Analysis
Simulation-guided Model Checking DREAM
Framework
Open-source DREAM Tool Automatic timed automata
model generation for the UPPAAL and Verimag IF
tools Simulation-guided model checking Performance
Estimation using DES Random testing Schedulabilit
y optimizations
http//dre.sourceforge.net
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Questions?

• Links to relevant work
• http//dre.sourceforge.net
• http//alderis.ics.uci.edu
• http//www.ics.uci.edu/gabe