Institute for Software Integrated SystemsVanderbilt University

Constraint-Based Embedded Program

CompositionPI: Ted Bapty

Sandeep Neema, Andy Gokhale, Jeff GrayInstitute for Software Integrated Systems

Vanderbilt Universityhttp://www.isis.vanderbilt.edu/projects/pces

Contract #: F33615-00-C-1695

Problem Description• Composition of Embedded Systems

– Close Coupling of Environment, Architecture & Requirements– All Requirements (Functional, Temporal, Interface, Resources) MUST be

satisfied.– How do we represent & maintain these requirements?

• Requirements Map to Constraints on System Implementation– Many Constraints Crosscutting the Design– Complex mapping from high-level requirements to constraints– How do we perform the mapping, distributing requirements?

• Need for flexibility to rapidly deploy designs to families of applications– How can we use constraints to adapt a core design to specific

application instances?– How can we provide better scalability?– OMG MDA

Project Objectives

• Create domain-specific, graphical languages that capture the functional design of real-time embedded systems– BBN UAV– Boeing Bold Stroke/CCM

• A weaving process that maps high-level invariant properties and system requirements to design constraints affecting specific model regions,

• A generation process that:– design space nav. -> customized component

composition– generate CDL; simulate/verify effects of contracts

Design-Space

Exploration andPruning

• Customized Component Composition

• CDL Gen• Contract Simulation• Contract Validation

Domain-SpecificStrategies

SpecificationAspects

Models

ConstrainedModels

Strategies (C++)

XML

Parser

Aspect

Parser

B

c d e1

3

2

B

c d e

strategy ApplyConstraint(constraintName : string, expression : string)

{

addAtom("OCLConstraint", "Constraint", constraintName).addAttribute("Expression", expression);

}

 

strategy RemoveConstraint(constraintName : string)

{

findAtom(constraintName).removeChild();

}

 

strategy ReplaceConstraint(constraintName : string, expression : string)

{

RemoveConstraint(constraintName);

ApplyConstraint(constraintName, expression);

}

constraint FOOB2

{

// apply a specific constraint to “B2” only

in Structural models("ProcessingCompound")->

select(p | p.name() == "B2")->PowerStrategy(1, 100);

}

constraint FOOBStar

{

// apply a specific constraint to all nodes beginning with “B” - use wildcard

in Structural models("ProcessingCompound")->

select(p | p.name() == "B*")->PowerStrategy(1, 100);

}

Meta-weaver

A

B

Meta-Model

BBN UAV OEP

Adaptive Quality Modeling Environment(AQME)

SpecificationAspects

MatlabSimulink/StateflowSimulation

SMV/LPEModelChecking

BBNQuOCDL

Adaptive Quality Modeling Environment

• QoS Specification and Adaptation modeling– Hierarchical, parallel, finite

state machine representation– States capture system-wide

QoS configurations– Transitions represent cause

and effect of change in operating conditions

– Data/Event variables represent the interface to the operating environment

Adaptive Quality Modeling Environment

• Software modeling– Hierarchical dataflow

representation• Compounds, primitives

– Parameters for component instrumentation and customization

• Middleware modeling– Services and system

condition objects– Parameters for

middleware instrumentation and customization

Simulation of QoS adaptation

• Matlab® Simulink®/Stateflow® used as the simulation engine

• Model interpreters generate Matlab M-code to construct Simulink/Stateflow representation

• User provides a network simulation model, that can simulate various load conditions in the network

UAV ModelMatlab M-file

I

Network model Simulation results

Adaptation model

I Interpreter

QuO Contract Generation

• AQME models translated to QuO contracts represented in Contract Definition Language (CDL)

• Hierarchical concurrent state machine models translated to flat state machine representation

• Transition guards and actions expressions over data/event variables translated to calls over Middleware (syscond) objects

UAV Model

I

QuO Contract (CDL)

BBNQuoGen .CPP

.H

.CPP

.H

Target Appl./MW

Verification of QoS adaptation

• Cornell LPE/SMV planned to be used as the model checking engine

• AQME models translated to LPE/SMV input specifications

• Can verify properties like reachability, liveness, fairness, etc. of the QoS adaptation specifications

UAV Model

I

SMV/LPE specification

SMV/LPE

CTL specs

Valid?

Counterexample

no

yes

reiterate

AnalogVideo

Receiver FrameGrabber

PPM video BBNDistribution

Controller

CDLContract

AQMEMIC Tool

“VanderBlimp” Demonstration Scenario

WithoutMIC & CDL

Client

Client

Client

Putting the ‘air’ in the UAV

OSHA Note:We use Helium

Control

CDLContract

CDLContract

CDLContract

CDLContract

future

future

Boeing BoldStroke OEP

Embedded Systems Modeling Language (ESML)DARPA MoBIES project

Specification

WeaponRelease

Sensor

LocDisplay

ComputePosition

Processor#1

Eager Eager Eager

Lazy

Processor#2

Design-SpaceExploration and

Pruning

Customized ComponentsUpdateMap

Lazy

Embedded Systems Modeling Language

(MoBIES)• BoldStroke/CCM

Components interaction modeling– Publish-subscribe event

communication mechanism

– Facets-Receptacles for data-communication

• Component internal interaction modeling– Event/data dependency

within the components internal data variables and methods

– Used to synthesize eager vs. lazy computation

A generalized component

class ComputePosition { public: void call_back() = 0; int get_data() = 0; …protected: void notify(); void data_retrieve(); void compute_phase1(); void compute_phase2(); … int _data;}

Customization of ComputePosition as a Lazy

componentclass LazyComputePosition : public ComputePosition { public: void call_back() { notify(); } int get_data() { data_retreive(); compute_phase1(); computer_phase2(); return _data; }protected: …

};

Customization of ComputePosition as an Eager

componentclass EagerComputePosition : public ComputePosition { public: void call_back() { data_retreive(); compute_phase1(); computer_phase2(); notify(); } int get_data() { return _data; }protected: …

};

Contribution To PCES• “analysis and transformation tools that achieve and preserve

required properties”– The mapping of requirements to constraints will contribute to the

achievement of system properties in the implementation.– OBDD-based constraint management

• “composition techniques that can be used cooperatively to support real-time programming”– Modeling component composition from requirements

• “programming reusable and portable aspect code”– Reusable libraries of weavers/aspects composing advice based on

system and application requirements to customize product family design

• “engineering approaches that can greatly reduce effort to program embedded systems”– Strategies for creating contracts & CDL generation

Contribution to Relevant Military Applications

• BBN UAV– Generation and management of complex behaviors (e.g., contracts)

• Systems are more adaptive to changing conditions• Systems make better use of resources to accomplish mission

– Evaluation/simulation of system behavior• System behavior known before deployment• More reliable systems, less chance of failure in ‘odd’ circumstances

• Bold Stroke:– Domain-specific application composition

• Rapid customization of military systems– Tuning implementations to system requirements, constraints

• Re-use of components one component fits all via customization (through aspects)

• Others (original project plan)– Software Radio

• Single platform design multiple waveform support• Efficient generation of HW/SW

– AMCOM Missile ATR• Rapid design-space tradeoff for architecture studies, • Coupled with SW/HW generation

Project Tasks/Schedule

• Definition Implementation of Constraint & Strategy Language– Constraint/Strategy Language Jan 01, Jan 02 (v2)

• Meta Weaver Framework Aug 01, Apr 02

• Design Space Exploration & Synthesis– CDL Generation (rev 1) Oct 01, Apr 02– OBDD Representation Apr 02, Aug 02– Aspect Selection/Customization Aug 02

• Demonstrations– Bold Stroke Apr 02, Aug 02– BBN UAV Apr 02– SWR Aug 03

Technical Progress/Accomplishment

• Definition Implementation of Constraint & Strategy Language– Constraint/Strategy Language (v1) – Models-to-XML Translation – Constraint Weaver Synthesis 90%

• Definition of Domain Modeling Languages – Component Modeling 80%– State/Contract (New) 90%

• Synthesis– CDL 90%– QoS adaptation Simulation (New) 70%– QoS adaptation Verification (New) 10%– Bold Stroke Component Composition 20%

• Demonstrations– BBN 80%– Boeing 10%

Next Milestones

• Complete remaining portion of weaver framework

• BBN UAV– Complete CDL generator– Complete Contract Simulation– Complete Contract Verification (SMV/LPE)– New strategy polices for state adaptation– Demonstration

• Boeing Bold Stroke– Complete Bold Stroke Modeling– Adapt Design Space Exploration for Aspect Selection– Generate Bold Stroke Component Composition– Demonstration

Collaborations

• OEP Interaction:– BBN

• Contract Modeling and Simulation/CDL Generation• UAV Demo

– Boeing• Bold Stroke Applications Modeling/Implementation

• Other PCES participants:– UVA/Boeing

• Modeling Collaboration, Tool Integration (GME/ESML)– Cornell

• Mapping our AQME models to XML for verification/analysis– GA Tech

• Collaborating on demo platform (using PPM image transport protocol)– PARC/UBC (planned)

• Component Behavior Composition

• Other DARPA projects: MoBIES– Extending Bold Stroke Modeling to support component composition with aspects

Tech Transfer

• Boeing– Modeling Tools (GME/ESML)– Customized components

• BBN – Modeling Tools (GME/AQME)– Simulation/CDL

• AFRL/IFGC (Rome AFB), Wayne Bonser (IFGC), Rodger Dziegel (IFTD)– Tools for Waveform Definition Language-to-Software Radio

Implementation• USARMY/AMCOM; Richard Sims (AMSAM-RD-MG-IP)

– Missile Embedded Systems, HW/SW Codesign• Other ISIS Collaborators:

– GM/Saturn, USAF/AEDC, Ford, NASA/MSFC, IBM, DuPont, Sandia, BAE/Sanders, Boeing, USMC, USAF/JSF, JPL, SWRI, Infineon,

Tech Transfer(continued)

• Workshop organization:– OOPSLA 2002 Workshop on Domain-Specific Visual Languages– AOSD Workshop on “Early Aspects”

• Publications/Interactions– AOSD Demonstration– Dissertation (Jeff Gray)– GCSE/SAIG 02 (submitted)– OOPSLA 02 (submitted)– HICSS 03 (4 papers submitted)– Real-Time OMG Workshop

Go/No Go Metrics

• [Bool] – Can we generate ‘real-world’ CDL contracts for xxxx complexity systems

• [int] – How many states can we design, simulate, analyze, and synthesize vs. hand-designed

• [float] – Turnaround time for a system behavior update vs. by-hand.

• [long?] Errors found/eliminated.• [long?] Lines of code generated/avoided vs.

hand-coded.• [?] How high can the blimp fly ;)

Program Issues

• None