1. Real-time Analysis of Resource-Constrained Distributed Systems by Simulation-Guided Model Checking
Gabor Madl
Ph.D. Candidate, UC Irvine
Advisor: Nikil Dutt
Chancellor’s Professor, UC Irvine
RTSS 2007 Ph.D. Forum
November 11, 2018

2. Analysis of Embedded Systems
Challenges Model-based Analysis Simulation-guided Model Checking DREAM Framework
Analysis of Embedded Systems
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
November 11, 2018

3. Continuous-time Analysis
Challenges Model-based Analysis Simulation-guided Model Checking DREAM Framework
Continuous-time Analysis
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
November 11, 2018

4. Need to Combine Analysis Methods
Challenges Model-based Analysis Simulation-guided Model Checking DREAM Framework
Need to Combine Analysis Methods
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
November 11, 2018

5. Model-based Design & Analysis
Challenges Model-based Analysis Simulation-guided Model Checking DREAM Framework
Model-based Design & Analysis
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
November 11, 2018

6. Domain-Specific Modeling
Challenges Model-based Analysis Simulation-guided Model Checking DREAM Framework
Domain-Specific Modeling
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
November 11, 2018

7. Simulation-Guided Model Checking
Challenges Model-based Analysis Simulation-guided Model Checking DREAM Framework
Simulation-Guided Model Checking
Parameters for components obtained by simulations
Utilize model checking and discrete event simulations on symbolic models to increase coverage
November 11, 2018

8. Architectural Exploration
Challenges Model-based Analysis Simulation-guided Model Checking DREAM Framework
Architectural Exploration
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
November 11, 2018

9. DREAM Analysis Framework
Challenges Model-based Analysis Simulation-guided Model Checking DREAM Framework
DREAM Analysis Framework
ALDERIS model GME tool
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
Schedulability optimizations
Verimag IF model checker
ALDERIS model XML representation
UPPAAL model checker
November 11, 2018

10. Links to relevant work:
Questions?
Links to relevant work:
RTSS 2007 Ph.D. Forum
November 11, 2018