JCMP: Linking Architecture with Component Building

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JCMP Linking Architecture with Component Building
SACT-01, Pusan, Nov. 30th, 2004 A previous
version has been presented at poster session of
ACM SIGSOFT 04 FSE-12 conference.

• Guoqing Xu, Zongyuan Yang and Haitao Huang
• Software Engineering Lab,
• East China Normal University

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Outline
SEL, East China Normal University

• Introduction and Motivation
• Our Techniques
• --- Triple-C Model
• --- JCMPL language
• ---JCMP toolset
• Analysis

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Problems and Motivation
SEL, East China Normal University

• Two basic characteristic of components defined in
  the architecture
• --- Conform to the architecture
• Follow the three criteria identified in
  LV95
• --- Support a great deal of flexibility
• A protocol or style is needed to support
  the independent building for the composite
  adaptation.
• These two issues are far from orthogonal although
  their concern is different.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Enforce the architectural conformance (current
research)
SEL, East China Normal University

• Three criteria identified in LV95
• ---Decomposition easy
• ---Interface conformance easy
• ---Communication Integrity hard

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Enforce Communication Integrity (current research)
SEL, East China Normal University

• Ask implementers to follow style guidelines
  (Rapide with C2 style Luc96)
• --- not enforced automatically
• Unify implementation and architecture in one
  language. (ArchJava ACN02)
• --- doesnt support architecture design.
• Both dont consider composite adaptation issues.
• --- there exists the direct client-server
  relationship between components.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Composite Adaptation (Current Research)
SEL, East China Normal University

• Use Module Interconnection Languages (MILs) to
  describe use relationship.
• --- Jiazzi or Knit
• Use on-demand remodularization.
• --- pluggable composite adapterMSL01
• They dont describe data and control flow between
  components and therefore cannot enforce
  communication Integrity.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Problem conclusions
SEL, East China Normal University

• Current solutions to either of two issues dont
  deal with another.
• How to support composite adaptation in the
  context of architectural constraints?

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Outline
SEL, East China Normal University

• Introduction and Motivation
• Our Approach
• --- Triple-C Model
• --- JCMPL language
• --- JCMP toolset
• Case study and Analysis

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Triple-C Model
SEL, East China Normal University

• Component-Communicate-through-Connector.
• It extends the three criteria in LV95 in two
  aspects
• --- A concrete connector in the implementation
  for each abstract connector in the architecture.
• --- Concrete connectors are used as wrappers
  to transfer the service flow between the
  components.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Model Overview
SEL, East China Normal University

• Currently the connector
• Specify the communication permission in the arch.
• Used as wrapper or glue code to transfer the
  methods invocation.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Basic ideas of our approach
SEL, East China Normal University

• Linking architecture with component building
  (composite adaptation).
• The key technique is to automatically generate
  the connector impl. from connector spec in the
  arch.
• We made a JCMP system
• --- an ADL JCMPL
• --- a toolset JCMP
• JCMP/Compiler JCMP/Match
• JCMP/Checker JCMP/Kernel

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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JCMPL Language
SEL, East China Normal University

• It uses the Java like grammar at an abstract
  level.
• It is not only an ADL, but also an IDL.
• It describes only abstractions, without any
  detailed type operations.
• Translated by JCMP/Compiler to the implementation
  skeleton.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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JCMPL Language (Cond.)
SEL, East China Normal University
//Parser.jcmpl public PrimComponent Parser
public port in RequireInterface r Token
nextToken()throws ScanExceptions
Public PrimComponent Scanner public port
out ProvideInterface req Token
next()
A Compiler Model
public AdvancedComponent Compiler public port
in RequireInterface get ... InputStream
getInputStream() public port out
ProvideInterface err Integer
getErrCode()... Scanner scanner
new Scanner() Parser parser new Parser()
connect sanner.out, parser.in
Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Generated Style
SEL, East China Normal University

• A concrete connector is generated.
• The component only requests the services from the
  connector and publishes their provided services.
• The connector performs the dynamic matching and
  transfer the invocation.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Dynamic interface matching
SEL, East China Normal University

• Searching for a pair of require-provide methods
  which match each other in semantic from two
  connected ports.
• Based on JML Spec. of each method.
• The matching strategy
• match_jcmp/match (P , R) (Rpre gt Ppre)
  ( (Ppre Ppost) gtRpost )
• Run P and R with test cases to watch whether
  their behaviors are observably equal.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Checking conformance in impl.
SEL, East China Normal University

• JCMP/Checker instruments methods with arguments
  of primitive types.
• It uses both architecture and implementations as
  input to check whether they conform to each
  other.
• If the impl. does not conform to the arch.,
  JCMP/Checker reports errors otherwise, it
  compiles the impl. Into the bytecode files
  (.class).

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Why it worksenforce communication integrity in
impl.
SEL, East China Normal University

• All interface methods are generated as private.
  This enforces that all interface methods cannot
  be directly called.
• The only way to call an interface method is
  through connector, which uses reflection to
  suppress access checking.
• The connector is generated automatically from
  connector spec., and methods comm. In impl. is
  therefore enforced to conform to its spec.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Why it workssupport composite adaptation
SEL, East China Normal University

• Concrete connector serves as glue codes.
• When a component is being built, if it requires a
  service, only requesting this from the conn.
• Conn. uses JCMP/Match to find the suitable
  method, calls the method, and finally returns the
  value back when the system is integrated.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Outline
SEL, East China Normal University

• Introduction and Motivation
• Our Techniques
• --- Triple-C Model
• --- JCMPL language
• ---JCMP toolset
• Analysis

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Performance Issues
SEL, East China Normal University

• The cost in running JCMP system has two
  components
• --- the runtime cost of type reflection.
• --- the extra cost of invocation transfer
  through the connector.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Experiment
SEL, East China Normal University

• Construct a linked list with a given array of
  integers.
• construct (int nodes)
• Retrieve a node from the given node ID after the
  list is constructed.
• retrieve (Integer index)

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Comparisons
SEL, East China Normal University
Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Analysis Summary
SEL, East China Normal University

• We found out that encapsulating the parameters of
  primitive types into objects took tremendous
  amount of time.
• The cost of method invocation through connector
  was not obvious.
• Since JCMP uses reflection, we suggest objects be
  used as data to be transferred, rather than
  primitive values.

Guoqing Xu, SACT-01, Pusan, Nov.30th, 2004
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Future Work

• JCMPL is only used at the design level, without
  supporting the dynamic description of runtime
  architecture.
• Architectural styles should be considered.
• The performance should be optimized in the way of
  having some other techniques to replace the Java
  reflection.

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Conclusions

• To link architecture with component building, we
  made
• Triple-C model
• JCMP toolset
• --- an ADL JCMPL
• --- JCMP system

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Thank you