Empirically Evaluating the Impact of Object-Centric Breakpoints on the Debugging of Object-Oriented Programs

Debugging consists in understanding the behavior of a program to identify and correct its defects. Breakpoints are the most commonly used debugging tool and aim to facilitate the debugging process by allowing developers to interrupt a program’s execution at a source code location of their choice and inspect the state of the program. Researchers suggest that in systems developed using object-oriented programming (OOP), traditional breakpoints may be a not effective method for debugging. In OOP, developers create code in classes, which at runtime are instantiated as object—entities with their own state and behavior that can interact with one another. Traditional breakpoints are set within the class code, halting execution for every object that shares that class’s code. This leads to unnecessary interruptions for developers who are focused on monitoring the behavior of a specific object. As an answer to this challenge, researchers proposed object-centric debugging , an approach based on debugging tools that focus on objects rather than classes. In particular, using object-centric breakpoints , developers can select specific objects (rather than classes) for which the execution must be interrupted. Even though it seems reasonable that this approach may ease the debugging process by reducing the time and actions needed for debugging objects, no research has yet verified its actual impact. To investigate the impact of object-centric breakpoints on the debugging process, we devised and conducted a controlled experiment with 81 developers who spent an average of 1 hour and 30 minutes each on the study. The experiment required participants to complete two debugging tasks using debugging tools with vs. without object-centric breakpoints. We found no significant effect from the use of object-centric breakpoints on the number of actions required to debug or the effectiveness in understanding or fixing the bug. However, for one of the two tasks, we measured a statistically significant reduction in debugging time for participants who used object-centric breakpoints, while for the other task, there was a statistically significant increase. Our analysis suggests that the impact of object-centric breakpoints varies depending on the context and the specific nature of the bug being addressed. In particular, our analysis indicates that object-centric breakpoints can speed up the process of locating the root cause of a bug when the bug can be replicated without needing to restart the program. We discuss the implications of these findings for debugging practices and future research.