JIVE depicts both the runtime state and execution history of a program in a visual manner. The runtime state is visualized as an enhanced object diagram, showing object structure as well as method activations in their proper object contexts. The execution history is depicted as a sequence diagram, clarifying the object interactions that occur at runtime. The diagrams are scalable and can be filtered to show only information pertinent to the task at hand. JIVE’s visualizations also make it an ideal pedagogic tool for teaching object-oriented programming.
JIVE provides an extensible set of queries over a program's execution history. Queries are formulated visually using the source code or the diagrams, and the results are shown in a tabular format and also as diagram annotations. Declarative debugging complements procedural debugging just as web searching complements web browsing. JIVE’s visualizations and query capabilities give the programmer greater insight into the execution of Java programs.
JIVE supports both forward and reverse stepping of Java programs. Often, a programmer may discover that an error has occurred only after the errant statement has been executed. Providing the ability to step backwards saves a programmer the time and effort of re-executing the program until the point of error. JIVE also provides the ability to jump directly back to any previous point in the execution history in order to observe the object diagram at that point. Reverse stepping and jumping work closely with query-based debugging to narrow down the cause of program errors.
Jeffrey Czyz is a PhD candidate studying under the supervision of Dr. Bharat Jayaraman at the University at Buffalo. He is currently researching declarative and visual execution environments for object-oriented software development. Jeff is the lead developer of the JIVE platform for Eclipse. JIVE is an interactive execution environment that supports a declarative and visual approach to debugging object-oriented software.