Time-Traveling Debugging Queries: Faster Program Exploration

Abstract

Efficiently debugging a program requires program comprehension. To acquire it, developers explore the program execution, a task often performed using interactive debuggers. Unfortunately, exploring a program execution through standard interactive debuggers is a tedious and costly task. In this paper, we propose Time-Traveling Queries (TTQs) to ease program exploration. TTQs is a mechanism that automatically explores program executions to collect execution data. This data is used to time-travel through execution states, facilitating the exploration of program executions. We built a set of key TTQs based on typical questions developers ask when trying to understand programs. We conducted a user study with 34 participants to evaluate the impact of our queries on program comprehension activities. Results show that, compared to traditional debugging tools, TTQs significantly improve developers' precision, while reducing required time and efforts when performing program comprehension tasks.

Scopeo: an Object-Centric Debugging Approach for Exploring Object-Oriented Programs

“…Back-in-time approaches [8]- [10] perform a full record of a program execution and provide ways to explore it afterward. Time-traveling approaches [11]- [13] perform a partial recording of an execution and replay that execution to allow live exploration of the program. With such a record, omniscient debugging approaches capture nondeterministic values and avoid the need for restarting the entire debugging process to inspect any part of the execution.…”

“…While replaying a given slice, the developers can step through it such as with standard tools. Seeker [13] supports the execution of Time-traveling queries (TTQs). TTQs allow developers to formulate questions about the execution of a program and to time-travel between the results provided by the debugger.…”

“…With Unstuck, developers are limited to a search in method trace view which is also manual and tedious. Finally, with time-traveling debuggers, the developer must rely on the back-and-forth navigation feature which remains manual and tedious [13].…”

“…Implementation: We implemented Scopeo with Pharo [16] because its standard debugger has had an object-centric breakpoint implementation in its production version for several years now. Seeker [17] is a time-traveling debugger prototype with object-centric features that integrates with the standard Pharo debugger. These make strong baselines to compare with Scopeo in future empirical evaluations.…”

“…The 134 test cases of Roassal ran under an acceptable time. Solutions like Seeker[17] can slow down test cases by a factor of 500 and are still applicable to the debugging of Pharo unit tests.…”