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We have developed and experimented with an approach to teach low-level Java concurrency abstractions in our first required course for CS majors, which assumes knowledge of procedural programming. The driving problems are visualized simulations of multiple physical objects in motion that may (a) be confined to a shared space and (b) coordinate with each other. Such simulations do not require any domain-specific knowledge such as sorting and image processing for driving problems and exercises, and their implementation demonstrates the benefits of object-based programming. They allow focus on both the performance and programmability benefits of concurrency, provide analogies for an abstraction-independent explanation of concurrency concepts, and can be used to incrementally motivate all low-level concurrency abstractions and visualize the effect of using and not using these abstractions. Layered simulation-based worked examples illustrating the abstractions were presented and easily understood in multiple offerings of a course that implemented this approach. Students implemented non-trivial assignments based on these abstractions, even when they were optional, did not face major obstacles because of visual error feedback, and were excited by concurrency as they felt it empowered them to implement arbitrary applications early.
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Lecture-Less Java-Threads Training in an Hour?
Introducing concurrent execution, forking, joining, synchronization, and load balancing of Java threads to trainees allows them to (a) create arbitrary concurrent algorithms, and (b) be exposed to the underpinnings of concurrency concepts. However, it requires the sacrifice of some existing concepts in the course in which such training is added. To keep this sacrifice low, we ambitiously explored if such concepts can be effectively introduced and tested in a single class period, which is approximately an hour, without a live lecture. Students were asked to learn the concurrency concepts by reading, running, fixing, and testing an existing concurrent program, and taking a quiz. They had varying knowledge of concurrency and Java threads but had not implemented concurrent Java programs. Both in-person and remote help were offered. They were allowed to finish their work after class, within a week. The vast majority of them who started on time finished the coding correctly and gave satisfactory quiz answers in ninety minutes. This experience suggests that such hands-on training can be usefully added to courses for training students and instructors that provide no other training in concurrency or training in declarative concepts. Our key ideas can be applied to languages other than Java.
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- Award ID(s):
- 1924059
- PAR ID:
- 10526698
- Publisher / Repository:
- IEEE
- Date Published:
- ISBN:
- 979-8-3503-8378-2
- Page Range / eLocation ID:
- 7 to 14
- Subject(s) / Keyword(s):
- fork, join, load balancing, synchronization, race conditions, automatic testing, hands-on training, Java threads
- Format(s):
- Medium: X
- Location:
- Goa, India
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/hipcw61695.2023.00010
