AOP The Road from Proliferation to Consolidation

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AOPThe Road from Proliferation to Consolidation

• Roberto E. Lopez-Herrejon
• AOSD-Europe Workshop
• Glasgow, Scotland
• July 24, 2005

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My Perspective

• Software Engineering
• Product Lines
• Software Composition and Generation
• Language support of Sw Eng. Principles
• What does AOP need to consolidate?

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AOP is growing
Languages
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Great Diversity

• Many languages and tools

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Diversity Benefits

• Tremendous source of innovation
• Interesting and unique aspect models
• Main research thrusts
• Semantically richer pointcuts
• Better tool support to identify and modularize
  concerns across software life cycle
• Better support for different platforms and
  application domains

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Diversity Drawbacks

• Creates confusion
• Too many options, so little time
• Which one should I use?
• Hinders adoption by the general public
• May appear immature for real world problems
• Is this really going to help me?
• Viable alternative
• Follow the leader, a.k.a. AspectJ

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Harnessing Diversity

• Acknowledge it exists and its importance
• Effort to publish AOSD surveys
• Identify criteria for comparison
• Language and execution model
• Compare and contrast languages
• Descriptive attempts
• Promote mutual benefit and enrichment

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Problems Wanted

• To compare and contrast languages
• Currently using several dimensions
• Low level, code snippets
• Not using common problems
• Modularization or crosscutting benchmarks
• Problems that highlight modularization
  capabilities
• Must have low background overhead
• An Example
• Expressions Product Line (EPL)
• Implemented in 8 languages

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Going Beyond Implementation Details

• The key is in software composition

New Program
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Example
CaesarJ
AspectJ
class C int x void m()
aspect A int C.n( )
public cclass L public cclass C int x
void m()
public cclass M public cclass C int n()

Both add a new method to a class
class C int x void m() int n()
class C int x void m() int n()
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Raising Abstraction Level

• What is needed is a general composition model
• Independent of languages
• Mathematical foundation of software composition
• For example
• C n where means add a method to a class
• AOP languages
• Described using composition operations supported
• Abstract lower level implementation details

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The Big Picture
Composition Expression
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Achieving Consolidation

• Proposal
• Devise common study problems
• Develop common composition model
• Benefits
• Improves mutual understanding
• Gives more cohesive perspective of AOP