Please read thru the overall exercises overview.

Exercise 7

In this exercise you will explore the benefits and limitations of inheritance-flavoured OOP and concurrency in Java.

2. I've created a shared data structure, Points, in the src folder. Use Java's concurrency API to implement access to this shared data structure.
   • Change the code in Driver.java so that the 3 clients run in three threads incrementing the points total and displaying the total points. Confirm that the results are stochastic, i.e., they change each time the code is run.
   • Then change this code to fix this with the concurrency API as discussed in videos/lectures. The result should be that the correct total is printed independent of thread execution.
3. Examine the concurrency approach used in either Scala, Erlang, or Go, and write a 1 page markdown file describing the pros and cons of ONE concurrency primitive in that language vs the Java equivalent. Remember to properly cite your references used (e.g., the Scala website, blog posts, academic papers).
4. Run PMD, a static analyzer, and find 3 code smells in your Ex 5 source code. If your code is already super clean, make some smelly code to get the detector to work.
   • I have added PMD to Gradle, so it should run the task gradle pmdMain for you (isn't Gradle wonderful?!). You can either copy this into your Ex 5 repo, or copy the code into this one.
   • Document what smells you found.
   • Now fix them using refactoring (other than rename). A good list of possible refactorings is https://refactoring.guru/refactoring.
   • Create a document that shows before and after code snippets. Do this by using commits, in which commit X-1 shows the bad smell, and commit X shows the refactored code. Your submission needs to record at least 6 commit SHA-1 hashes (the first 8-10 characters are fine): 3 before and 3 after.
   • Link to the line of code in which the smell occurs, like this: https://github.com/SENG330/ex5_starter/commit/83d5a6e8866432bf9e7453b87e0e97996db778ca#diff-9c1be2884a04419ef1ad1b7f690b2b48d230027d27ca6b09efc23e0ecb04aa91R14

Learning Objectives

• types and inheritance
• concurrency and its mechanisms in Java and other languages
• static analysis tools and refactoring

Deliverables

• No ADR necessary unless specific design decisions should be explained to the TA.
• the 1 page (750 words max) compare and contrast file. I've created the skeleton for this file already as contrast.md.
• a markdown file with Github links to the 6 refactoring related commits (use refactoring.md).
• a markdown file (concurrency.md) with the 2 concurrency related commits.

Tips

• You can link to specific commits in Github files by adding the SHA1 hash id of the commit.

Due

• We will mark the last commit made before Nov 8 at 11:59pm. If that last commit was a mess, let us know. Make sure your code compiles!
• By midnight Nov 11, submit your team peer review form via the webapp (link omitted to prevent spam).