Dynamic aspects for runtime fault determination and recovery

One of the most promising applications of aspect oriented programming (AOP) is the area of fault tolerance and recovery. In traditional programming languages, error handling code must be closely interwoven with program logic. AOP allows the programmer to take a more modular approach - error handling code can be woven into the code by expressing it as an aspect. One major impediment to handling error code in this way is that while errors are a dynamic, runtime property, most research on AOP has focused on static properties. In this paper, we propose a method for handling a variety of run-time faults as dynamic aspects. First, we separate fault handling into two different notions: fault determination, or the discovery of faults within a program, and fault recovery, or the logic used to recover from a fault. Our position is that fault determination should be expressed as dynamic aspects. We propose a system, called Rescue, that exposes underlying features of the virtual machine in order to express faults as variety of run-time constraints. We show how our methodology can be used to address several of the flaws in state of the art fault handling techniques. This includes their limitations in handling parallel and distributed faults, their obfuscated nature and their overly simplistic notion of what a "fault" actually may comprise