Levels of Independence in Aspect-Oriented Modeling Workshop on Model-driven Approaches to Middleware Applications Development June 17, 2003 Jeff Gray, Yuehua Lin, Jing Zhang gray (at) cis.uab.edu This research is funded by DARPA/IXO, under the PCES program.

Shameless Plug for CFPs Workshop on Domain-Specific Visual Languages  September 22, 2003 (GPCE Conference - Erfurt, Germany)  Papers due: 30 June 3 rd OOPSLA Workshop on Domain-Specific Modeling (Domain-Driven Development Track)  October 26, 2003 (OOPSLA - Anaheim, CA)  Papers due: 15 August

Shameless Plug for CFPs Aspect-Oriented Modeling Workshop  October 20-24, 2003  UML Conference (San Francisco, CA)  Papers due: 25 August

Types of Transformation & Translation Horizontal transformation  Transformation within the same representation level of abstraction  e.g., MDA PIM->PSM, model weaving (VEST, C-SAW), code refactoring Vertical translation  Typically, translation, or synthesis, between layers of abstraction  e.g., MIC interpreters, CASE-tool scripting and reverse engineering, PSM->PSI ComputePosition C++ ComputePosition with Locking C++ NavDisplay C++ Current Focus: Vertical transformation – higher level models transform existing code base (rather than synthesize new code or configuration information) Current Focus: New model weaver (C-SAW) integrated within GME

Multiple Levels of Hierarchy Replicated Structures Context Sensitive Motivating Problem – Crossccuting Constraints in Real-Time/Embedded Models Base models become constrained to capture a particular design A B cde B cde F B cde Changeability ??? Crosscutting Constraints Constraints that are related to some global property are dispersed across the model

“Small changes in requirements entail large changes in the structure and configuration” [Sussman, 1999]Gerald Jay Sussman, “Robust Design through Diversity,” DARPA Amorphous Computing Workshop,

Motivation Problems:  Difficult to specify and manage cross- cutting concerns (e.g., constraints) in model-based systems;  Lack of tool support for automatically weaving constraints into models;  New: Lack of a core weaving engine that is independent of modeling environments.

Previous Work (Solution) Strategies (C++) Meta-weaver Framework Domain-Specific Strategies strategy ApplyConstraint(constraintName : string, expression : string) { addAtom("OCLConstraint", "Constraint", constraintName).addAttribute("Expression", expression); } strategy RemoveConstraint(constraintName : string) ApplyConstraint(constraintName, expression); } Domain-specific strategies (encoded in a DSL) are used to instantiate a new model weaver Specification Aspects Domain-specific Models B c d e constraint FOOB2 { // apply a specific constraint to “B2” only in Structural models("ProcessingCompound")-> // apply a specific constraint to all nodes beginning with “B” - use wildcard in Structural models("ProcessingCompound")-> select(p | p.name() == "B*")->PowerStrategy(1, 100); } Specification aspects and base model are sent through the weaver Constrained Models B c d e The weaver distributes constraints across the base model

Two levels of weaving Weapon Release Sensor LocDisplay Compute Position Processor #1 Eager UpdateMap Eager Lazy bit1 bit1 Structural ProcessingCompound GatesPerBit Aspect Code Generation Processor #2 Aspect Model Weaving Aspect Code Weaving/ Program Transformation

Levels of Independence in Model Weaving Domain independence:  GME meta-models and weaver strategies determine domain of discourse Platform independence:  GME interpreters and weaver strategies map to platform specific synthesis Tool independence (new):  Separation of core weaving engine with tool- specific adapters

Tool Independence Requires an exposed API for accessing internal model data structures Tool-specific adapters written for each new supported tool Cadena GME MetaEdit Rose

Adaptive Core Weaving Engine

Not unlike AspectJ AJDT JBuilder Eclipse emacs Netbeans/FORTE AJDT

More Info Representative Publications:  Comm. of the ACM, October 2001, “Handling Crosscutting Constraints in Domain-Specific Modeling”  GPCE 2003 (forthcoming), “An Approach for Supporting Aspect-Oriented Domain Modeling”  AOSD Book Chapter (forthcoming), “Two-Level Weaving to Support Evolution of Model-Based Software” Demo  Prepared to give a very brief demo of: GME Example weaving of processor assignment constraints into an avionics system model

Demo Very brief intro to GME  Entire course on this, so very superficial demo Weaving of constraints into GME models I’ll have to talk fast…

Model Integrated Computing (MIC) Grew out of over 14 years of research on computer- based systems in aerospace, instrumentation, manufacturing and robotics. Common challenges: “Software” and “environment” are inextricably combined Need for adaptability to changing environment and end-user needs Complex, heterogeneous applications Stringent reliability and dependability requirements

Domain-Specific Modeling at ISIS: Model Integrated Computing The Generic Modeling Environment (GME) is a domain-specific modeling tool (>20-person years) It can be utilized in many different domains by providing a meta-level paradigm description  Paradigm describes all of the entities of the domain, as well as valid relationships Freely available:  See November 2001 issue of IEEE Computer

DOMAIN-MODEL Meta-Modeling Framework META-MODEL Meta-Model of Stateflow using UML/OCL as meta-modeling language. Model instance of Stateflow

Model Integrated Computing Environment Evolution Meta-Level Translation Metaprogramming Interface Formal Specifications Model Interpreters Models DSME Model Builder Model Interpretation Application Domain App. 1 App. 2 App. 3 Application Evolution

GME

MIC Applications