Adapting virtual machine techniques for seamless aspect support

Abstract

Current approaches to compiling aspect-oriented programs are inefficient. This inefficiency has negative effects on the productivity of the development process and is especially prohibitive for dynamic aspect deployment. In this work, we present how wellknown virtual machine techniques can be used with only slight modifications to support fast aspect deployment while retaining runtime performance. Our implementation accelerates dynamic aspect deployment by several orders of magnitude relative to mainstream aspect-oriented environments. We also provide a detailed comparison of alternative implementations of execution environments with support for dynamic aspect deployment.

Supporting dynamic aspect-oriented features

“…For example, these constructs might rely on the dynamic control flow of a program and can't easily be statically composed with the original code, without requiring additional logic. These dynamic constructs have received a lot of attention in the past 3-4 years of aspect-oriented programming literature [2,6,7,8,15,19,20,35,36,40,41].…”

On the design of software composition mechanisms and the analysis of composition conflicts

“…This coordinator object ensures that the synchronization "bookkeeping" itself is properly synchronized. While the advice holds a lock on this object (line [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], it can safely inspect the MethodState objects for this coordinator. For each method (involved in synchronization), such a Meth-odState object tracks which threads are currently running that method.…”

“…For each method (involved in synchronization), such a Meth-odState object tracks which threads are currently running that method. While other threads are active in any method in the exclusion set of the currently invoked method (line 21,22), the advice waits (releasing the lock on the coordinator while waiting) until this is no longer the case (line [24][25][26]. When the loop is left, it means the method is free to run -after the advice registers the current thread with the corresponding MethodState object (line 30) and releases the lock on the coordinator object.…”

“…This framework is structured similarly to JAMI, but contains more detailed information necessary to enable efficient implementations, such as discussed in [25]. Because of the structural resemblance, it should be possible to (manually) map JAMI models to ALIA models.…”

“…To implement this restriction, we create an additional constraint between each inheritance binding and the one "to the left" of it (except for the first parent), specifying that if the binding on the left matches, the one on the right should be skipped. Note that it is possible to create such additional constraints between existing inheritance bindings, since the definition of module Extends allows us to access the inheritance binding it defines; alert readers may have noticed the accessor implementation in listing 5.3 (lines [23][24][25][26].…”