Chameleon Files

In the 2.0 version, the Mobile Client, the Server, the Resource Model, the Analyzer , and the Registry have been completely revised and extended according to the novel approach that support the Hybrid (static and dynamic) Analysis.
The hybrid approach is based on a new Resource Model that characterizes the notion of resources.
It uses an Abstract Resource Analyzer (ARA) that statically scans the bytecode abstract syntax tree of Java applications and refines the associated resource sets using a transition system. The latter models the semantics of the bytecode in terms of resource consumption. ARA is parametric with respect to a Resource Consumption Profile that, dynamically sent by the CHAMELEON-enabled devices requesting an application, associates resource consumption to particular patterns of Java bytecode instructions. The profile permits to define the resource consumption associated to both basic instructions (e.g., ipush, iload) and to complex ones such as method calls. In particular, the dynamic phase of the analysis avoids to statically performs the expensive inter-procedural call-closure for library methods.
The preprocessor derives the Application Descriptor that, among other information, also lists the calls to external library methods for each alternative. Specifically, for each external method call in the list, the programmer (supported by the CHAMELEON IDE - see the user guide of the CHAMELEON IDE) specifies the worst-case call-context on the base of the application logic that has been coded. When a device requests an application, during the dynamic phase of the analysis, each library method is then executed by the CHAMELEON Client in the target execution environment, and its actual resource consumption is computed. This consumption is used to specify into the profile the resources consumed by each library