Palantír: Early Detection of Development Conflicts Arising from Parallel Code Changes

The earlier a conflict is detected, the easier it is to resolve-this is the main precept of workspace awareness. Workspace awareness seeks to provide users with information of relevant ongoing parallel changes occurring in private workspaces, thereby enabling the early detection and resolution of potential conflicts. The key approach is to unobtrusively inform developers of potential conflicts arising because of concurrent changes to the same file and dependency violations in ongoing parallel work. This paper describes our research goals, approach, and implementation of workspace awareness through Palantír and includes a comprehensive evaluation involving two laboratory experiments. We present both quantitative and qualitative results from the experiments, which demonstrate that the use of Palantír, as compared to not using Palantír 1) leads to both earlier detection and earlier resolution of a larger number of conflicts, 2) leaves fewer conflicts unresolved in the code base that was ultimately checked in, and 3) involves reasonable overhead. Furthermore, we report on interesting changes in users' behavior, especially how conflict resolution strategies changed among Palantír users.