A LAYERED MODEL FOR BUILDING DEBUGGING AND MONITORING TOOLS

In this article we describe a new layered model for building debugging and monitoring tools. The model separates the different functionaliti es of these tools into a number of well-defined layers and defines sta ndardized interfaces between these layers. Individual layers can be im plemented independently. Lower layers hide the operating system and ar chitecture dependencies from the higher layers, thus allowing the same higher layers to be used on different systems. On the other hand, the same lower layers can be shared by similar tools, each of which might have a different implementation of the high-level functions. We have built a working implementation of this model and working prototype deb uggers, profilers, and data tracers that use this model.