Debugging Backwards in Time

TL;DR

This paper introduces a novel debugging approach that records all program states to enable backward navigation through execution history, simplifying bug detection and fixing.

Contribution

It presents the concept of backward debugging, a GUI for global program state visualization, and integration with an event analysis engine, advancing debugging tools.

Findings

Successful implementation on large programs

Encouraging results from user studies

Discussion of performance and optimization strategies

Abstract

By recording every state change in the run of a program, it is possible to present the programmer every bit of information that might be desired. Essentially, it becomes possible to debug the program by going ``backwards in time,'' vastly simplifying the process of debugging. An implementation of this idea, the ``Omniscient Debugger,'' is used to demonstrate its viability and has been used successfully on a number of large programs. Integration with an event analysis engine for searching and control is presented. Several small-scale user studies provide encouraging results. Finally performance issues and implementation are discussed along with possible optimizations. This paper makes three contributions of interest: the concept and technique of ``going backwards in time,'' the GUI which presents a global view of the program state and has a formal notion of ``navigation through time,'' and the integration with an event analyzer.