Towards a Generic Aspect Oriented Design Process

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Towards a Generic Aspect Oriented Design Process

• Andrew Jackson, Siobhán Clarke
• Distributed Systems Group
• Trinity College Dublin

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Problems?
We surveyed 22 AOD approaches (aosd-europe.net -
9000 downloads)
Many different levels of design
abstraction High-middle-low
Different levels of concern separation are
supported
AOD Approach
AOD Languages
AOD Processes
Heuristics for AOD not are not typically across
all approaches AOSDUC, AVA and Theme are
examples of exceptions
There is scope for language integration The
better language features can be composed into a
new AOD language
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Survey uncovered
UML is a basis for many AOD languages and
processes
UML
Extension needed to support crosscutting
Approaches place emphasis on particular views
Behavioral structural views
Meta model
Crosscutting must be described in all views
Crosscutting and non-crosscutting concern design
Composition specification
Concern model design
Many approaches are prog-language dependant
needs to be more generic Also needs to be visual
Typically not well defined
Composition semantics
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Problem

• AOD is useful on its own it can be complemented
  by full methodology support!
• AORE/AOA gtgtgt AOD
• Concerns may be identified and classified before
  the designer needs to translate requirements into
  architecture conformant design
• AOD gtgtgt OOP/AOP
• Allows expression of concerns that are not
  directly resizable i.e. performance

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AOD within the Development Methodology
Core Requirements
Domain Analysis
Requirements Gathering
Modularisation of concerns
Requirements Analysis
Composition of concerns
XP
System specification
Conflicts or cooperation
Architecture Design
RUP
Traceability to earlier later stages
System Design
Mapping of earlier later constructs
Methodology Survey
Requirements Gathering Session
Development
General Requirements
Testing
Deployment
Open, customizable independent
Training
Artefact and process metrics
Maintenance
Extend successful methodologies
System Quality Assurance
Support staged adoption
Provide product line/family support
Process Quality Assurance
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Initial Process Meta-Model
Open traceability allows mappings to many
pre-design activities AO / non-AO
Extend methods testing is more and more
becoming central to existing methods
Concern identification classification
Design test(s)
Product lines, allows commonalities to be
captured and applied in different scenarios
Core requirements
Design concern Module(s)
Design composition Specification(s)
Reuse design(s)
Verify
Refine
PIM/PSM traceability through incremental
specialisation
Formal methods integration metrics can be
applied
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Refinement
Concern and/or composition analysis
High level design
Design process (CAM)
Refine
Platform independent and/or composition design
detail defined
Middle level design
Design process (DAOP)
Refine
Platform specific concern design and/or
composition
Refine
Low level design
Design process (CORBA)
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A case study

• Auction System Evaluate fondue
• http//lgl.epfl.ch/research/fondue/case-studies/au
  ction/problem-description.html
• Like ebay.com ubid.com - web
• Buy items at auction
• Highest bid wins join bid message
  notification
• Sell items by auction
• Closes after a certain time period
• And all the regular stuff
• Login-out
• Manage account

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Refinement Iteration 1
Inputs to the process were tangled use
cases User-goal level Bid-Offer-Increases
credit Sub Functional Search-Close-Identify user
Concern identification classification
Concern identification classification
Concern identification classification
Design concern Module(s)
Design composition Specification(s)
Concern identification allows reject input /
accept AO input / build non AO model
Concern identification allows reject input /
accept AO input / build non AO model
Design concern Module(s)
Design by reuse
No crosscutting - so just build a declaratively
complete concern
Design composition Specification(s)
Specify integration resolving conflicts and
cooperation issues
Design composition Specification(s)
Design concern Module(s)
Refine
Refine
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Process result first pass
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Refinement Iteration 2
Through designing the input concerns the
crosscutting concerns became clear
Concern identification classification
Concern identification classification
Concern identification classification
New crosscutting found other concerns altered
View, Registration, Transfer Credit, Join,
Message, Observe
Design Crosscutting concern by beginning at the
crosscutting interface and work toward defining
the particular views
Design concern Module(s)
Design concern Module(s)
Design concern Module(s)
Design by reuse
Design composition Specification(s)
Design composition Specification(s)
Observer was predefined in previous work and
instead of re-defining I decided to reuse it!!!
Design composition Specification(s)
Crosscutting composition was then specified
Refine
Test Refine
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Process result second pass
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Refinement Iteration 3
Concern identification classification
Concern identification classification
Through Testing the design by composition a new
concern emerged the setup concern
Concern identification classification
Design concern Module(s)
Design composition Specification(s)
Design concern Module(s)
Design the composition specification in relation
to all the other concern as setup affects the
entire system
Design by reuse
Design composition Specification(s)
Design composition Specification(s)
Design concern Module(s)
Design the crosscutting setup concern
Refine
Refine
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End result
Next phase would be to implement AO or OO?
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Design Composition
Concern
Concern
Used when input provides clear descriptions of
concerns and concern relationships may be used
in waterfall methodologies or where
requirements/architecture are stable
Used when input is imperfect or changeable also
in methodologies that require products after each
release i.e. XP
Concern
Composition
Concern
Composites
Composite
Concern
Concern
Composition
Concern
Concern
Composition
Composition
(a) Continual cumulative composition
More useful when a component based approach is
being taken. Is applicable where systems
decomposed into separate sub systems
(c) Hierarchical composition
(b) Once off composition
Composition
Concern
Concern
Concern
Concern
Composite
Composite
Concern
Concern
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Future and ongoing work

• Process
• Case study Auction and other systems will be
  used to test different configurations of the
  design process
• Look at process simulation???
• Language
• Integration of three models of AO
• AspectJ
• Component
• Subject oriented

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The End Thank you. Questions\Comments Lunch?
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Initial Language
UML 2.0 meta-model extension
Modelling crosscutting and non-crosscutting
concerns
Platform independent
AO meta-model (e.g. Theme)
Platform specific
AspectJ profile
HyperJ profile

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Auction System Design
Result of following the AOD process using an
integration AOSUC, Theme/UML and SUP processes
Now - walk through the process describing one
instantiation of this process
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Extras

• Here are the extra slides I am amending it is
  my intuition that these may help me answering
  questions on the process

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Concern id classification
ignore
Analyse inputs
Reanalyse
Separated concerns identified classified
Inputs are scattered and tangled
Identify concerns relevant during design
Create poorly modularised design
Identify all concerns
Refine
Classify concerns
Verify
Non-crosscutting concerns
Crosscutting concerns
Other classifications
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Design Tests
Design test(s)
Reuse design test(s)
Design tests for composition Specification(s)
Design test(s) for concern modules
Compose design test(s) for Composite concern
modules
Reuse composition specifications test(s)
Verify
Refine
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Design by reuse
Search design repository
Test design
No Match
gt 1 Match
Assess design relevance
Do or do not select for reuse
Design new concern compositions
Do Not
Do
Contextualize reused Designs
Verify
Assess potential for reusability
Yes - reusable
Reengineer Decontextualize
Add to design repository
Design prepared for reuse
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Concern Module Design
Design concern module
Identify design sub-concern modules
Non-crosscutting
Crosscutting
Other classifications
Define concern Interface
Define concern crosscutting Interface
Create structural design views
Create structural design views of crosscutting
Create behavioral Design views
Create behavioural design views of crosscutting
Test design
Verify
Refine
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Composition Specification Design
Design composition specification
Determine order for composition
Determine structural composition
Determine behavioral composition
Define where structure is to be composed
Define where behavior is to be composed
Define how structure is to be composed
Define how behavior is to be composed
Identify resolve conflict issues
Test composition
Verify
Refine