Automating Software Evolution through Model-

Driven Engineering Troy University8th Annual Computer Science Colloquium on Information TechnologyApril 3, 2007 – Rosa Parks Auditorium

Previous support by DARPA/IXO PCES. Current funding from NSF-CSR and NSF CAREER.

Department of Computer and Information SciencesUniversity of Alabama at Birmingham

S o f t C o m Jeff GrayUAB – CIS Department

Overview of Presentation

Motivation

Background

Domain-SpecificModeling

Video Demos

Research Focus

Model-Driven Software Evolution

Overview of SoftCom

Example Case Studies

Model Transformation Toolsuite• Model Transformation Engine• Transformation Testing Framework• Model Transformation Debugger• Model Version Control• Model-Driven Program Transformation

•Evolution of large legacy apps from models

TransformedBold Stroke C++ codeCommon/Project

Library ofBold Stroke C++

Source Code

DMS Transform

ationRules

DMSvoid BM__PushPullComponentImpl::Update (const UUEventSet& events){ BM__ComponentInstrumentation::EventConsumer(GetId(), "Update", events);

unsigned int tempData1 = GetId().GetGroupId(); unsigned int tempData2 = GetId().GetItemId(); std::vector<BM__ClosedComponent*>::iterator devIter =

void BM__PushPullComponentImpl::Update (const UUEventSet& events){

UM__GUARD_EXTERNAL_REGION(GetExternalPushLock()); BM__ComponentInstrumentation::EventConsumer(GetId(), "Update", events); 

default base domain Cpp~VisualCpp6.pattern UM_GUARD_EXTERNAL_REGION_as_identifier_or_template_id(): identifier_or_template_id = "UM__GUARD_EXTERNAL_REGION".pattern GetExternalPushLock_as_identifier_or_template_id(): identifier_or_template_id = "GetExternalPushLock".pattern ExternalLockStmt(): expression_statement = "\

default base domain Cpp~VisualCpp6.pattern UM_GUARD_EXTERNAL_REGION_as_identifier_or_template_id(): identifier_or_template_id = "UM__GUARD_EXTERNAL_REGION".pattern GetExternalPushLock_as_identifier_or_template_id(): identifier_or_template_id = "GetExternalPushLock".pattern ExternalLockStmt(): expression_statement = "\

ESML Models

Jing Zhang and Jane Linwww.cis.uab.edu/gray/Research/C-SAW/

Software Composition and Modeling Laboratoryhttp://www.cis.uab.edu/softcom/

Hui Wuwww.cis.uab.edu/wuh/DDF

Eclipse DSL Debugging Framework

12

6

1 begin2 left3 down4 up5 right6 end

4

Lexer,Parser

public class Robot{ public static void main(String[] args) { …… //move left x=x-1; time=time+1;

//move down y=y-1; time=time+1; …… } }

3

import java.util.ArrayList;

public class Mapping { ArrayList mapping; public Mapping(){ mapping=new ArrayList(); mapping.add(new Map(1, "Robot.java",2,8)); mapping.add(new Map(2, "Robot.java",10,14)); …… } }

Mapping Component

5

Robot DSL Grammar In ANTLR Notation

Robot DSL

Generated Lexer, and Parser by ANTLR

Robot.java and Mapping.java

Java Command Line Debugger

Robot DSL Debugging Perspective in Eclipse

DebuggerView

DSLEditor

Variables View

Supported by:Eclipse Innovation Grant

• Framework for building debuggers and testing engines for different categories of domain-specific languages

• AspectG is an aspect weaver for grammars

Speech Enabled Software Development

• Assistive technology for disabled programmers• Integrates open source speech recognition with a popular open IDE• Videos and papers available at:

www.cis.uab.edu/info/Eclipse/SpeechClipse

SpeechClipse

Language Independent Refactoring and Aspect Weaving

Suman Roychoudhurry

www.cis.uab.edu/softcom/GenAWeave

Software Composition and Modeling Laboratoryhttp://www.cis.uab.edu/softcom/

Clone Detection and Visualization

Robert Tairas

www.cis.uab.edu/tairasr/clones

• Visualization and analysis of clone detection results from CloneDR as an Eclipse plug-in

High School Outreach at UAB CISMentoring for Science Fair Competitions Summer Robotics Internship

• Weekly mentoring at UAB throughout academic year; students treated like a PhD student with office space

www.cis.uab.edu/gray/Pubs/jerrod-sutton.pdf

Computer Graphics Camp

www.cis.uab.edu/heritage

www.cis.uab.edu/progams/hspcwww.cis.uab.edu/cscamp/

• Week-long summer camp in computer graphics• Students use C++ and OpenGL to create projects focused on geometric modeling, algorithm visualization, and motion design

High School Programming Contest

• Seven-week internship• Students taught Java through series of robotics projects

• May 12, 2007• 2006: 46 students

from 12 schools (Huntsville to Mobile)

• 6 problems in 3 hours• Prizes: Laptop, Xbox,

software, books, gift certificates

• Alice Film Festival!

High School Outreach at UAB CISField Trips to the CIS Department Lectures for Technology Clubs

•3-hour tour of the CIS department:• Several topical lectures• Over 150 students in Fall 2006• Free Pizza lunch!

http://www.cis.uab.edu/field-trips

Alabama K-12 Workshop

http://www.cis.uab.edu/programs/hsws/

• July 31, 2006; 16 state-wide participants

• Purpose: To discuss critical issues needed to raise awareness of computing in Alabama schools.

Dual/Concurrent Enrollment

CIS faculty are available to give topical lectures to classes; if interested, faculty can help bootstrap a club

• Opportunity to earn college credit in the summer by taking the CIS 201 course (Intro to Java)

• 3-4 students each summer• Potential tuition waiver in some cases• Greatly speed up mentoring experience• Prepare students for programming

contest next May• “Concurrent/Dual” enrollment http://www.cis.uab.edu/cs201

SpeechClipse video demo…

http://www.cis.uab.edu/info/Eclipse/SpeechClipse/demo.html

Domain-Specific Modeling

Categories of End-Users

AdminAssistants

Businessman

Auto Factory Worker

Scientist

Spreadsheet

BusinessQuery Systems

Modeling Language

DSL forPhysics

Question

But what is a model?

(Naïve introduction)

Next Few slides adapted from Jean Bezivin….

A very popular model: geographical maps (thanks to Jean Bezivin for this idea)

Models

repOfSystem

2000 Census Map

Aerial Map

Model Road Map

The System

1819 City Plan

Every map has a legend

legend = metamodel

Model

c2

Metamodel

Another Notation (DSL)

Model

Metamodel

c2

Music notation

Sheet music

Executable Model

Power Tab Editor

Two Views:

Traditional notes

Guitar tab

Assisted Drawing Tools (e.g. MS/Visio)

c2Metamodel Model

(thanks to Jean Bezivin for this slide)

Schema definitions: Going “Meta”

Domain-SpecificModeling

ProgrammingLanguage Definition

Database SchemaDefinition

Schema definitionMetamodel for aspecific domain(e.g., Petri Net)

Grammar for a specificlanguage (e.g., Java)

Table, constraint, and storedprocedure definitions for a

specific domain (e.g., payroll database)

Schema instance

Domain model (e.g., Petri Net model of a teller

machine)

A program written in aSpecific language

Intension of a database at aspecific instance in time

(e.g., the June 2006 payrollinstance)

Schema execution Model InterpreterLanguage

compiler/interpreter

Transactions and behavior ofstored procedures

in an executing application

Characteristics of Modeling Languages Each model conforms to its

metamodel A model is a representation

of a system satisfying substitutability For each question that can be

asked of the system, the model produces the same answer Not true for me and road maps!

(from Jean Bezivin)

Observation “One size fits all” approach is appearing to be

inadequate for many end-user needs Too complex and contains “kitchen sink” approach

providing things most users do not need (UML) Current trend is to provide “domain-specific”

modeling languages that are customized to a specific domain Notations and abstractions are exactly what the

users expects; focused on problem space, not technology solution space

But, how to create such modeling languages and environments? Expensive to create from scratch for each domain

ModelInterpretation

Model Interpreters

Models

Modeling Environment

ApplicationDomain

App1

App2

App3

Application Evolution

Environment Evolution

MetamodelingInterface

Metamodel Definition

Meta-LevelTranslation

Model Builder

Background: Domain-Specific Modeling (cont’d)M

etamodel

Model

Interpreter

void CComponent::InvokeEx(CBuilder &builder,CBuilderObject *focus, CBuilderObjectList &selected, long param) {CString DMSRoot = "";DMSRoot = SelectFolder("Please Select DMSRoot Folder:");if (DMSRoot != "") {DMSRulePath = DMSRoot + RULESPATH + "Rules\\";MSRuleApplierPath = DMSRoot + RULESPATH + "RuleApplier\\";AfxMessageBox("DMSRulePath = " + DMSRulePath , MB_OK);CString OEPRoot = "";OEPRoot = SelectFolder("Please Selec

DEFINE

INTERPRET

The Generic Modeling Environment (GME) adopts the DSM approach and provides a plug-in mechanism for extension.

Example DSMLs (not UML)

Model-Driven Software EvolutionModel-Driven Program Transformation with C-SAW

With Jane Lin and Jing Zhang

Supported previously by DARPA PCESand a current NSF CSR and NSF CAREER grant.

The “Twisted Plot” MetaphorThe Problem of Keeping Track of Things in Your Head

• The interactions among characters and overlapping events makes a good novel (“thickness” of plot as a complexity metric)

• The author must take care in preserving, throughout the entire novel, internal consistency within plot

• e.g., a change in the conclusion of the plot may necessitate global changes in all chapters

• Keeping track of all the twists can be difficult because the various concerns of the plot are distributed across multiple chapters

• but…Software development is MANY orders of magnitude more difficult!

Logically Consistent?

…

Chapter 2

Conclusion

Chapter 1

…

Core Focus: Ability to evolve models The size of system models will continue to grow

Models containing several hundreds or even thousands of modeling elements

Others have reported similarly (Johann/Egyed – ASE 2004) A key benefit of modeling

Ability to explore various design alternatives (i.e., “knobs”) E.g., understanding tradeoff between battery consumption

and memory size of an embedded device E.g., scaling a model to 800 nodes to examine performance

implications; reduce to 500 nodes with same analysis… Reducing complexities of the modeling activity

Limit the amount of mouse clicking and typing required within a modeling tool to describe a change Improves productivity and reduces potential manual errors

A general metric for determining the effectiveness of a modeling toolsuite comprises the degree of effort required to make a correct change to a set of models.

Key Challenges: Crosscutting Concerns in Domain-Specific Models

Challenge 1: Crosscutting Models Base models become constrained to capture a

particular design Concerns that are related to some global property are

dispersed across the model Solution: Model Weaving

C-SAW is an aspect-oriented weaver at the modeling level

Changeability???

Multiple Levels

of HierarchyReplicatedStructures

ContextSensitive

A

B

c d eB

c d e

F

B

c d e

Crosscutting Constraints

Challenge 2: Fidelity Between Models and Code Changes to models must have a causal connection to underlying source Parsing large legacy systems and performing required adaptations is too difficult for each

new system to be encountered Solution: Model-Driven Program Transformation

A model interpreter generates DMS transformation rules from properties described in models

Challenge 1: Solved with Aspect-Oriented ModelingCrosscutting Constraints in Real-Time/Embedded Models

Implemented as a GME plug-in to assist in the rapid adaptation and evolution of models by weaving crosscutting changes into models.

C-SAW: Model Transformation Engine

ECL Interpreter

ECL Parser

Defines

MetaModel

Source Model

Mo

de

ling

AP

Is

Defines

ECL Transformation Specifications

Defines CopyAtom strategy CopyAtom

Mo

de

ling

AP

IsAspect

Weaving

Target Model

Key Challenge 2: Evolution of legacy models and code

∆MM: The changes made to the meta-models∆M: The changes reflected in the domain models∆I: The changes reflected in the legacy source

Legacy Source1

Model1

Metamodel1

Define

Interpret

Legacy Sourcen

Modeln

Metamodeln

Define

Interpret

Legacy Source0

Model0

Metamodel0

Define

Interpret

∆M 1

∆MM 1

∆I 1

∆M 2

∆MM 2

∆I 2

∆M n

∆MM n

∆I n……

……

……

Based

on

What about other artifacts of the modeling process during metamodel evolution?Interpreters, constraints, model transformations…

1. Model weaving to explore design alternatives more rapidly

• Design decisions crosscut model hierarchy

• Difficult to change models to new configuration

• Design decisions captured as higher level policy strategies and weaved into models

2. Model driven program transformation• Ensures causal connection between

model changes and represented source code of legacy system

• Assists in legacy evolution from new properties specified in models

• Model interpreters generate transformation rules to modify source

3. Experimentation:Boeing’s Bold Stroke Application

• Apply original Bold Stroke C++ source code and generated transformation rules to DMS; result is a transformed version of Bold Stroke that is consistent with the model specification

void BM__PushPullComponentImpl::Update (const UUEventSet& events){ BM__ComponentInstrumentation::EventConsumer(GetId(), "Update", events); unsigned int tempData1 = GetId().GetGroupId(); unsigned int tempData2 = GetId().GetItemId(); std::vector<BM__ClosedComponent*>::iterator devIter = devices_.begin(); std::vector<BM__ClosedComponent*>::iterator endIter = devices_.end(); for (; devIter != endIter; ++devIter) { BM__ClosedComponent* component = *devIter; const UUIdentifier& id = component->GetId(); if (idInEventSet(id, events)) { const BM__ClosedFunctionalFacet& facet = component->ProvideClosedFunctionalFacet(); BM__ComponentInstrumentation::SendDirectCall(GetId(), "Update", component->GetId(), "GetData1"); tempData1 += facet.GetData1(); BM__ComponentInstrumentation::SendDirectCall(GetId(), "Update", component->GetId(), "GetData2"); tempData2 += facet.GetData2(); } } data1_ = tempData1; data2_ = tempData2;}

void BM__PushPullComponentImpl::Update (const UUEventSet& events){

UM__GUARD_EXTERNAL_REGION(GetExternalPushLock()); BM__ComponentInstrumentation::EventConsumer(GetId(), "Update", events);  unsigned int tempData1 = GetId().GetGroupId(); unsigned int tempData2 = GetId().GetItemId();  std::vector<BM__ClosedComponent*>::iterator devIter = devices_.begin(); std::vector<BM__ClosedComponent*>::iterator endIter = devices_.end();  for (; devIter != endIter; ++devIter) { BM__ClosedComponent* component = *devIter; const UUIdentifier& id = component->GetId();  if (idInEventSet(id, events)) { const BM__ClosedFunctionalFacet& facet = component->ProvideClosedFunctionalFacet(); BM__ComponentInstrumentation::SendDirectCall(GetId(), "Update", component->GetId(), "GetData1"); tempData1 += facet.GetData1(); BM__ComponentInstrumentation::SendDirectCall(GetId(), "Update", component->GetId(), "GetData2"); tempData2 += facet.GetData2(); } }

UM__GUARD_INTERNAL_REGION; log.add(“data1_=”+data1_); data1_ = tempData1; data2_ = tempData2;

log.add(“data2_=”+data2_);}

DMS Xform Rules

Base C++ Source CodeTransformed

C++ Code

GME ModelModeling Aspect

1

2

3

Solution: Two-Level Aspect Weaving

Weaved Model

//show("Data fields exist. Add two concurrency atoms.");//add the first concurrency atomconcurrencyAtom1 := addAtom("Concurrency", "InternalLock");concurrencyAtom1.setAttribute("Enable", "1");// "1" is true, "0" is falseconcurrencyAtom1.setAttribute("LockType", "Thread Mutex");concurrencyAtom1.setAttribute("LockStrategy", "Internal Locking");//add the second concurrency atomconcurrencyAtom2 := addAtom("Concurrency", "ExternalLock");concurrencyAtom2.setAttribute("Enable", "1");// "1" is true, "0" is falseconcurrencyAtom2.setAttribute("LockType", "Thread Mutex");concurrencyAtom2.setAttribute("LockStrategy", "External Locking");

Case Study:Bold Stroke Product Line

Background Context Mission-control software for Boeing military aircraft

under development since 1995 (F-15/F-18) CORBA event-based systems Thousands of components implemented in over 4 million

lines of C++ code Key Challenges

Difficult to evolve the underlying source representation to address new requirements; impossible to determine, a priori, all of the future adaptation requests

Difficult to migrate the source representation to newer component models

Example: C-SAW Assertion Strategy

default base domain Cpp~VisualCpp6. pattern assertStmt() : statement = "assert(data1_>200);". pattern aspect(s:statement_seq): statement_seq = " \assertStmt\(\){ \s }". pattern joinpoint(id:identifier): qualified_id = "\id :: Update". rule precondition(ret:decl_specifier_seq, id:identifier, p:parameter_declaration_clause, s:statement_seq): function_definition -> function_definition = "\ret \joinpoint \(\id\)(\p){\s}" -> "\ret \joinpoint \(\id\)(\p){\aspect\(\s\)}" if ~[modsList:statement_seq .s matches "\:statement_seq \apect\(\modsList\)"]. public ruleset applyrules = { precondition }.

void BM__ClosedEDComponent:: Update(const UUEventSet& events)

{

assert(data1_>200); // <- Precondition BM_CompInstrumentation:: EventConsumer(GetId(), "Update", events); unsigned int tempData1 = GetId().GetGroupId(); unsigned int tempData2 = GetId().GetItemId(); //* REMOVED code for Real-time Event Channel //* REMOVED actual variable names (proprietary) data1_ = tempData1; data2_ = tempData2;

assert(data1_<500); // <- Postcondition

}

strategy FindData1(){ atoms()->select(a | a.kindOf()=="Data" and a.name()=="data1_")->AddConds();}

strategy AddConds(){ declare p : model; declare data, pre, post : atom; data := self; p := parent();

pre:=p.addAtom("Condition","PrecondData1_"); pre.setAttribute("Kind", "PreCondition"); pre.setAttribute("Expression", "data1_>200"); p.addConnection("AddCondition", pre, data); post:=p.addAtom("Condition", "PostcondData1_"); post.setAttribute("Kind", "PostCondition"); post.setAttribute("Expression", "data1_<500"); p.addConnection("AddCondition", post, data); }

aspect Start(){ rootFolder().findFolder("ComponentTypes"). models()->select(m|m.name().endWith("Impl"))->FindData1(); }

Video Demonstration:C-SAW and Model-Driven Program Transformation

http://www.cis.uab.edu/gray/Research/C-SAW/video-demo.htm

Evolving a black-box data recorder…

New Challenge: Replicating a Base Model to Address Scalability Issues

Model Scalability Base models must be replicated to explore alternative designs Model elements need to be replicated, in addition to all

required connections

Single UAV Model Three UAV Model

Example applications Event QoS Aspect Language

Specify properties of event-based communication within a DRE (e.g., mission-computing avionics)

System Integration Modeling Language Specify properties of high-performance physics

experiments

UAV QoS Language (not described here) Specify properties of video QoS in an Unmanned

Aerial Vehicle

A language to address performance issues among distributed systems using network patterns

Scaling the Event QoS Aspect Languagestrategy expandSite(site, numGW : integer){ findModel("Site " + intToString(site)).addGateWay_r(1, numGW);}

strategy addGateWay_r(curr, numGW : integer){ if (curr <= numGW) then addGateWay(curr); addGateWay_r(curr+1, numGW); endif;}

strategy addGateWay(num : integer){ declare site_gw : atom; declare ec : model;

site_gw := addAtom("CORBA_Gateway", "CORBA_Gateway" + intToString(num)); ec := findModel("Event_Channel"); addConnection("LocalGateway_EC", site_gw, ec); }

Conclusion and Ongoing Work Benefits of Model-Driven Engineering

Captures domain abstractions that are appropriate for an end-user; enables analysis at higher levels of abstraction

Model transformations assist in evolution tasks that would be too tedious and error prone to do manually

Ongoing Work Framework for testing the correctness of model

transformations Model differentiation algorithms “Model Transformation by Example” Version control of models at proper abstraction level Evolution of other modeling artifacts in an automated manner

Related Web Pages

http://www.cis.uab.edu/Research/C-SAW/Contains papers, downloads, video demos

C-SAW

SoftCom Research Lab

http://www.cis.uab.edu/softcom

K-12 Outreach Activities

http://www.cis.uab.edu/gray/OutreachContains papers, posters, and video demos

Department of Computer and Information SciencesUniversity of Alabama at Birmingham

S o f t C o m

Development Forces100+ DevelopersLengthy product lifecyclesComponent orientedMillions of SLOC1,000s of component instances

Domain ForcesEmbeddedDistributedHRT + SRTMission CriticalStringent performance requirements

Avionics Mission Computing Context

Wendy Roll, Boeing

PCES-1 Focus: Simulating Joint OEP Scenario

Design

Initial Implementations Complete for:• 1 UAV Case• 3 UAV Case (@ Demonstration)• 30 UAV Case (With Weaver)

Synthesis

Execution

Modeling of Adaptive QoS Systems•Adaptive Behaviors•Environmental stimulus•Middleware interfaces

Generative technology•Matlab and Stateflow simulations•QuO CDL