Automating Software Evolution
through Model-Driven Engineering
Troy University
8th Annual Computer Science Colloquium on Information Technology
April 3, 2007 – Rosa Parks Auditorium
SoftCom
Jeff Gray
UAB – CIS Department
Department of Computer and Information Sciences
University of Alabama at Birmingham
Previous support by DARPA/IXO PCES. Current funding from NSF-CSR and
NSF CAREER.
Overview of Presentation
Background
Domain-Specific
Modeling
Overview of SoftCom
Motivation
Research Focus
Video Demos
Example Case Studies
Model-Driven
Software Evolution
Software Composition and Modeling Laboratory
http://www.cis.uab.edu/softcom/
Model Transformation Toolsuite
• Model Transformation Engine
• Transformation Testing Framework
• Model Transformation Debugger
• Model Version Control
• Model-Driven Program Transformation
Eclipse DSL Debugging Framework
Robot.java and Mapping.java
Robot DSL
1
2
3
4
5
6
begin
left
down
up
right
end
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;
……
2
3
1
}
}
Lexer,
Parser
•Evolution of large legacy apps from models
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));
……
}
}
Generated Lexer, and Parser
by ANTLR
Robot DSL Grammar In ANTLR Notation
ESML
Models
DMS
Transform
ation
Rules
Variables
View
Debugger
View
4
6
5
Mapping
Component
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_identi fier_or _te
mplate_id(): identifier_or_template_id =
"GetExternalPushLock".
pattern ExternalLockStmt():
expression_statement = "\
DSL
Editor
Java Command Line Debugger
void BM__PushPullComponentImpl::Update (const
UUEventSet& events)
{
DMS
BM__ComponentInstrumentation::EventConsumer(GetI
d(), "Update", events);
void BM__PushPullComponentImpl::Update (const
UUEventSet& events)
{
BM__ComponentInstrumentation::EventConsumer(Ge
tId(), "Update", events);
unsigned int tempData1 = GetId().GetGroupId();
unsigned int tempData2 = GetId().GetItemId();
std::vector<BM__ClosedComponent*>::iterator
devIter =
Common/Project
Library of
Bold Stroke C++
Source Code
Robot DSL Debugging Perspective in Eclipse
UM__GUARD_EXTERNAL_REGIO
N(GetExternalPushLock());
Transformed
Bold Stroke
C++ code
Jing Zhang and Jane Lin
www.cis.uab.edu/gray/Research/C-SAW/
• Framework for building debuggers and
testing engines for different categories
of domain-specific languages
• AspectG is an aspect weaver for
grammars
Hui Wu
www.cis.uab.edu/wuh/DDF
Supported by:
Eclipse Innovation Grant
Software Composition and Modeling Laboratory
http://www.cis.uab.edu/softcom/
Speech Enabled Software Development
SpeechClipse
• Assistive technology for disabled
programmers
• Integrates open source speech
recognition with a popular open IDE
• Videos and papers available at:
Clone Detection and Visualization
www.cis.uab.edu/info/Eclipse/SpeechClipse
Language Independent
Refactoring and Aspect Weaving
• Visualization and analysis of clone
detection results from CloneDR as
an Eclipse plug-in
Suman Roychoudhurry
www.cis.uab.edu/softcom/GenAWeave
Robert Tairas
www.cis.uab.edu/tairasr/clones
High School Outreach at UAB CIS
Mentoring for Science Fair Competitions
• 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
• Week-long summer camp
in computer graphics
• Students use C++ and
OpenGL
to
create
projects
focused
on
geometric
modeling,
algorithm
visualization,
and motion design
www.cis.uab.edu/cscamp/
Summer Robotics Internship
• Seven-week internship
• Students taught Java through series of
robotics projects
www.cis.uab.edu/heritage
High School Programming Contest
• 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!
www.cis.uab.edu/progams/hspc
High School Outreach at UAB CIS
Field Trips to the CIS Department
•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
• July 31, 2006; 16 statewide participants
• Purpose:
To
discuss
critical issues needed to
raise
awareness
of
computing in Alabama
schools.
http://www.cis.uab.edu/programs/hsws/
Lectures for Technology Clubs
CIS faculty are available to give topical
lectures to classes; if interested, faculty
can help bootstrap a club
Dual/Concurrent Enrollment
• 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
Spreadsheet
Admin
Assistants
Business
Query Systems
Businessman
Auto Factory
Worker
Scientist
Modeling
Language
DSL for
Physics
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
1819 City Plan
2000 Census Map
The System
Aerial Map
System
repOf
Model
Road Map
Every map has a legend
legend = metamodel
Metamodel
c2
Model

Another Notation (DSL)
Executable Model
Music notation
Power Tab Editor
Metamodel
c2
Model
Sheet music
Two Views:
Traditional notes
Guitar tab
Assisted Drawing Tools (e.g. MS/Visio)


Metamodel
c2
Model
(thanks to Jean Bezivin for this slide)
Schema definitions: Going “Meta”
Domain-Specific
Modeling
Programming
Language Definition
Database Schema
Definition
Grammar for a specific
language (e.g., Java)
Table, constraint, and stored
procedure definitions for a
specific domain
(e.g., payroll database)
Schema definition
Metamodel for a
specific domain
(e.g., Petri Net)
Schema instance
Domain model
(e.g., Petri Net
model of a teller
machine)
A program written in a
Specific language
Intension of a database at a
specific instance in time
(e.g., the June 2006 payroll
instance)
Model Interpreter
Language
compiler/interpreter
Transactions and behavior of
stored procedures
in an executing application
Schema execution
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


Current trend is to provide “domain-specific”
modeling languages that are customized to a
specific domain


Too complex and contains “kitchen sink” approach
providing things most users do not need (UML)
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
Background: Domain-Specific Modeling (cont’d)
M
e
t
a
m
o
d
e
l
Metamodeling
Interface
Environment
Evolution
Application
Domain
Application
Evolution
App
1
Metamodel Definition
App
2
App
3
DEFINE
Modeling
Environment
M
o
d
e
l
I
n
t
e
r
p
r
e
t
e
r
Model Builder
Meta-Level
Translation
INTERPRET
void CComponent::InvokeEx(CBuilder &buil
der,CBuilderObject *focus, CBui
lderObjectList &selected, long param)
{
CString DMSRoot = "";
DMSRoot = SelectFolder("Please Select DMS
Root Folder:");
if (DMSRoot != "") {
DMSRulePath =
DMSRoot + RULESPATH + "Rules\\";
MSRuleApplierPath
= DMSRoot + RULESPATH + "RuleApplier\\";
AfxMessageBox("DMSRulePath =
" + DMSRulePath , MB_OK);
CString OEPRoot = "";
OEPRoot = SelectFolder("Please Selec
Model
Interpretation
Models
Model Interpreters
The Generic Modeling Environment (GME) adopts the DSM
approach and provides a plug-in mechanism for extension.
Example DSMLs (not UML)
Model-Driven Software Evolution
Model-Driven Program Transformation with C-SAW
With Jane Lin and Jing Zhang
Supported previously by DARPA PCES
and a current NSF CSR and NSF CAREER grant.
The “Twisted Plot” Metaphor
The Problem of Keeping Track of Things in Your Head
• The interactions among characters and
Chapte
r1
Chapte
r2
…
…
Conclusion
Logically
Consistent?
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!
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
Multiple
Levels
of Hierarchy
c
A
B
d
C-SAW is an aspect-oriented
weaver at the modeling level
d
B
e
c
d

Changeability???
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

e
Context
Sensitive
Challenge 2: Fidelity Between Models and Code


e
c
Crosscutting Constraints

F
B
Solution: Model Weaving

Replicated
Structures
A model interpreter generates DMS transformation rules from properties
described in models
Challenge 1: Solved with Aspect-Oriented Modeling
Crosscutting Constraints in Real-Time/Embedded Models
C-SAW: Model Transformation Engine
MetaModel
Defines
Defines
ECL Parser
Modeling APIs
Modeling APIs
ECL Interpreter
Aspect
Weaving
Source Model
Target Model
Defines CopyAtom
strategy CopyAtom
ECL Transformation
Specifications
Implemented as a GME plug-in to assist in the
rapid adaptation and evolution of models by
weaving crosscutting changes into models.
Key Challenge 2: Evolution of legacy models and code
∆MM 1
Metamodel0
∆MM 2
Metamodel1
Define
∆MM n
Metamodeln
Define
Based on
∆M 1
Model0
Define
∆M 2
Model1
Interpret
……
∆M n
Modeln
Interpret
∆I 1
Legacy
Source0
……
Interpret
∆I 2
Legacy
Source1
……
∆I n
Legacy
Sourcen
∆MM: The changes made to the meta-models
∆M: The changes reflected in the domain models
∆I: The changes reflected in the legacy source
What about other artifacts of the modeling process during metamodel evolution?
Interpreters, constraints, model transformations…
Solution: Two-Level Aspect Weaving
1. Model weaving to explore design
alternatives more rapidly
1
//show("Data fields exist. Add two concurrency atoms.");
//add the first concurrency atom
concurrencyAtom1 := addAtom("Concurrency", "InternalLock");
concurrencyAtom1.setAttribute("Enable", "1");// "1" is true, "0" is false
concurrencyAtom1.setAttribute("LockType", "Thread Mutex");
concurrencyAtom1.setAttribute("LockStrategy", "Internal Locking");
//add the second concurrency atom
concurrencyAtom2 := addAtom("Concurrency", "ExternalLock");
concurrencyAtom2.setAttribute("Enable", "1");// "1" is true, "0" is false
concurrencyAtom2.setAttribute("LockType", "Thread Mutex");
concurrencyAtom2.setAttribute("LockStrategy", "External Locking");
Modeling Aspect
GME Model
• 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
Weaved Model
• 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
2
DMS Xform
Rules
Base C++ Source Code
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;
}
3
Transformed
C++ Code
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_);
}
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
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
strategy FindData1()
{
atoms()->select(a | a.kindOf()=="Data" and a.name()=="data1_")->AddConds();
void BM__ClosedEDComponent::
}
Update(const
UUEventSet& events)
default base
domain Cpp~VisualCpp6.
{
strategy AddConds()
pattern
assertStmt() :
{
statement = "assert(data1_>200);".
declare p : model;
declareassert(data1_>200);
data, pre, post : atom; // <- Precondition
pattern aspect(s:statement_seq):
data := self;
p := parent();
statement_seq = " \assertStmt\(\){ \s }".
BM_CompInstrumentation::
patternEventConsumer(GetId(),
joinpoint(id:identifier): "Update", events);
pre:=p.addAtom("Condition","PrecondData1_");
unsigned
int tempData1
= GetId().GetGroupId();
qualified_id
= "\id :: Update".
pre.setAttribute("Kind", "PreCondition");
unsigned int tempData2 = GetId().GetItemId();
pre.setAttribute("Expression", "data1_>200");
p.addConnection("AddCondition",
data);
rulepre,
precondition(ret:decl_specifier_seq,
//* REMOVED
code for Real-time Event Channel
id:identifier,
}
post:=p.addAtom("Condition", "PostcondData1_");
//* REMOVED actual variable names (proprietary)
p:parameter_declaration_clause,
post.setAttribute("Kind", "PostCondition");
post.setAttribute("Expression", "data1_<500");
data1_ =s:statement_seq):
tempData1;
p.addConnection("AddCondition", function_definition
post, data);
-> function_definition
data2_ = tempData2;
= "\ret \joinpoint \(\id\)(\p){\s}"
// <- Postcondition
->assert(data1_<500);
"\ret \joinpoint \(\id\)(\p){\aspect\(\s\)}"
aspect Start()
{
if ~[modsList:statement_seq .s matches
rootFolder().findFolder("ComponentTypes").
} "\:statement_seq \apect\(\modsList\)"].
models()->select(m|m.name().endWith("Impl"))->FindData1();
public ruleset applyrules = { precondition }.
}
Video Demonstration:
C-SAW and Model-Driven Program Transformation
Evolving a black-box data recorder…
http://www.cis.uab.edu/gray/Research/C-SAW/video-demo.htm
New Challenge:
Replicating a Base Model to Address Scalability Issues
Single UAV Model
Three UAV Model
Model Scalability


Base models must be replicated to explore alternative designs
Model elements need to be replicated, in addition to all
required connections
Example applications

Event QoS Aspect Language


System Integration Modeling Language


Specify properties of high-performance physics
experiments
UAV QoS Language (not described here)


Specify properties of event-based communication
within a DRE (e.g., mission-computing avionics)
Specify properties of video QoS in an Unmanned Aerial
Vehicle
A language to address performance issues among
distributed systems using network patterns
strategy expandSite(site, numGW : integer)
{
Scaling the Event QoS Aspect Language
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 enduser; 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
C-SAW
http://www.cis.uab.edu/Research/C-SAW/
Contains papers, downloads, video demos
K-12 Outreach Activities
http://www.cis.uab.edu/gray/Outreach
Contains papers, posters, and video demos
SoftCom Research Lab
SoftCom
http://www.cis.uab.edu/softcom
Department of Computer and Information Sciences
University of Alabama at Birmingham
Avionics Mission Computing Context
Domain Forces
Development Forces
Embedded
100+
Distributed
HRT
+ SRT
Mission Critical
Stringent performance requirements
Developers
Lengthy product lifecycles
Component oriented
Millions of SLOC
1,000s of component instances
Wendy Roll, Boeing
PCES-1 Focus: Simulating Joint OEP Scenario
Modeling of Adaptive QoS Systems
Generative technology
•Adaptive Behaviors
•Environmental stimulus
•Middleware interfaces
•Matlab and Stateflow simulations
•QuO CDL
Execution
Synthesis
Design
Initial Implementations Complete for:
• 1 UAV Case
• 3 UAV Case (@ Demonstration)
• 30 UAV Case (With Weaver)