Nu: a Dynamic Aspect-Oriented Intermediate Language Model and Virtual Machine for Flexible Runtime Adaptation

By: Robert Dyer and Hridesh Rajan

Abstract

A variety of dynamic aspect-oriented language constructs are proposed in recent literature with corresponding, compelling use cases. Such constructs, as well as other existing constructs such as cflow, demonstrate the need to dynamically adapt the set of join points intercepted at a fine-grained level. The notion of morphing aspects and continuous weaving is motivated by this need. In this work, we propose an intermediate language model called Nu, that extends object-oriented intermediate language models with two finegrained deployment primitives: bind and remove. These primitives offer a higher level of abstraction as a compilation target for dynamic aspect-oriented language constructs, compared to object-oriented intermediate language models, thereby making it easier to support such constructs. We also present the design and implementation of a prototype virtual machine that supports the Nu model, which serves to show that it is feasible to support such a flexible and dynamic intermediate language model in a production level virtual machine. We demonstrate the potential utility of the intermediate language design by expressing a variety of aspect-oriented source language constructs of dynamic flavor such as CaeserJ’s deploy, history-based pointcuts, and control flow constructs such as cflow in terms of the Nu model.

Other Info

Previous version appeared as Technical Report 07-06, Computer Science, Iowa State University, June 03, 2007.

See also this preliminary poster paper on this topic: FSE-2006

ACM Reference

Dyer, R. and Rajan, H. 2008. Nu: a Dynamic Aspect-Oriented Intermediate Language Model and Virtual Machine for Flexible Runtime Adaptation. AOSD ’08: Proceedings of the 7th International Conference on Aspect-oriented Software Development (New York, NY, USA, 2008).

BibTeX Reference

@inproceedings{dyer2008nu,
  author = {Robert Dyer and Hridesh Rajan},
  title = {Nu: a Dynamic Aspect-Oriented Intermediate Language Model and Virtual Machine for Flexible Runtime Adaptation},
  booktitle = {AOSD '08: Proceedings of the 7th International Conference on Aspect-oriented Software Development},
  year = {2008},
  location = {Brussels, Belgium},
  publisher = {ACM},
  address = {New York, NY, USA},
  entrysubtype = {conference},
  abstract = {
    A variety of dynamic aspect-oriented language constructs are proposed in
    recent literature with corresponding, compelling use cases. Such constructs,
    as well as other existing constructs such as cflow, demonstrate the need to
    dynamically adapt the set of join points intercepted at a fine-grained level.
    The notion of morphing aspects and continuous weaving is motivated by this
    need. In this work, we propose an intermediate language model called Nu, that
    extends object-oriented intermediate language models with two finegrained
    deployment primitives: bind and remove. These primitives offer a higher level
    of abstraction as a compilation target for dynamic aspect-oriented language
    constructs, compared to object-oriented intermediate language models, thereby
    making it easier to support such constructs.

    We also present the design and implementation of a prototype virtual machine
    that supports the Nu model, which serves to show that it is feasible to
    support such a flexible and dynamic intermediate language model in
    a production level virtual machine. We demonstrate the potential utility of
    the intermediate language design by expressing a variety of aspect-oriented
    source language constructs of dynamic flavor such as CaeserJ's deploy,
    history-based pointcuts, and control flow constructs such as cflow in terms
    of the Nu model.
  }
}