Theoretical and Practical Approaches for Teaching Parallel Code Correctness

The introductory-level courses on parallel programming, typically, do not cover the topic of code correctness. Often, students learn about the logical errors in parallel programs and troubleshoot them through trial and error, and spend a significant amount of time and effort in the process. A systematic pedagogical approach to teaching parallel code correctness is therefore needed to enhance the productivity of students and instructors. In this paper, we describe some theoretical and practical approaches that can be adopted for assessing and teaching parallel code correctness. The theoretical approaches include using formal methods (e.g., Petri nets and Hoare Logic). We apply these approaches on the test cases discussed in this paper. The practical approach involves teaching code correctness through demonstrations. For enabling this, we have not only curated a repository of parallel programs with commonly made logical errors but have also added a high-level interface on top of the repository for quickly comparing fixed and incorrect versions of the sample code in the repository, seeing the explanation text on the errors, and searching the repository on the basis of the causes and symptoms of logical errors. The work presented in this paper can potentially motivate the instructors in including the content on code correctness in their parallel programming courses and trainings.