Program Summary
Modern-day software operates within a complex ecosystem of libraries, models, protocols and devices. Ecosystems change over time in response to new technologies or paradigms, as a consequence of repairing discovered vulnerabilities (security, logical, or performance-related), or because of varying resource availability and reconfiguration of the underlying execution platform. When these changes occur, applications may no longer work as expected because their assumptions on how the ecosystem should behave may have been inadvertently violated.
Ensuring applications can seamlessly continue to operate correctly and usefully in the face of such changes is a formidable challenge. Failure to effectively and timely adapt to ecosystem evolution can result in technically inferior and potentially vulnerable systems, but the lack of automated mechanisms to restructure and transform applications when changes do occur leads to high software maintenance costs and premature obsolescence of otherwise functionally sound systems. Neither of these outcomes is desirable and poses significant risk to economic productivity and cyber resilience.
Successfully adapting applications to an evolving ecosystem requires mechanisms to infer the impact of such evolution on application behavior and performance, automatically trigger transformations that beneficially exploit these changes and provide validation that these transformations are correct. To do so requires the ability to: (a) extract whole-system specifications over the entire software stack that can be used to define application-centric descriptions of the resources provided by the ecosystem; (b) leverage new programming abstractions, program analyses, and compilation methodologies to correlate application behavior with salient ecosystem changes; (c) develop semantics-preserving program transformations designed with adaptation in mind; and (d) exploit new runtime systems and virtual machine implementations structured to facilitate the efficient integration of these transformations.
The goal of the Building Resource Adaptive Software Systems program (BRASS) is to realize foundational advances in the design and implementation of long-lived, survivable and complex software systems that are robust to changes in the physical and logical resources provided by their ecosystem. These advances will necessitate integration of new resource-aware program abstractions and analyses, in addition to novel compiler and systems designs to trigger adaptive transformations and validate their effectiveness.