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Executor tasks

Java Multithreading
Level 8 , Lesson 10
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16
Task
Java Multithreading, level 8, lesson 10
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Mastering Callable
Implement the getTask method. It should return a Callable object. The Callable object must calculate the sum of the numbers from 1 to the passed number (i), inclusive, and return it as a String. The main method is not tested.
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32
Task
Java Multithreading, level 8, lesson 10
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Plants vs Zombies
1. Read about java.util.concurrent.Phaser. 2. Put the methods in the right places: - arriveAndDeregister(): starts calling the tasks' run methods, - arriveAndAwaitAdvance(): waits for all threads to be created.
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9
Task
Java Multithreading, level 8, lesson 10
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ReentrantReadWriteLock
The ReadWriteMap class must correctly provide access to a Map object across multiple threads, but mistakes were made during implementation. Find them and fix them.
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9
Task
Java Multithreading, level 8, lesson 10
Locked
FutureTask
The FactorialCalculator class is designed to calculate the factorial of a number passed to its constructor as an argument. Unfortunately, it is not implemented correctly and you need to fix it. Carefully analyze the Solution class's main method.
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Comments (6)
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java_study Level 32, Minden, Germany
17 August 2022
Very complex tasks that require a lot of time. I didn't expect this. I really regret taking this course.
Justin Smith Level 41, Greenfield, USA, United States
5 May 2022
Yeah, this stuff is getting pretty hard. But remember that when you started CodeGym, upon completion of a task you would find that thousands of other people had completed the task as well. But now we find that only 200-300 people have completed these tasks. If you're finishing these you're doing a lot better than almost everyone else who started.
catalin1989 Level 37, Romania
12 March 2024
It is pretty lonely here. When I started, there were thousands of people, now there are hundreds :).
Andrei Level 41
18 May 2021
Also, this is a very good resource showing the differences between CyclicBarrier, Phaser and CountDownLatch - https://www.youtube.com/watch?v=J3QZ5gfCtAg
MaGaby2280 Level 41, Guatemala City, Guatemala
11 February 2021
These are some great links for the Java Phaser: https://www.baeldung.com/java-phaser https://www.geeksforgeeks.org/java-util-concurrent-phaser-class-in-java-with-examples/ https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Phaser.html
Seb Level 41, Crefeld, Germany
7 February 2020
A hint for Plants vs Zombies: The methods arriveAndDeregister() and arriveAndAwaitAdvance() need to be used in the start method - and they each need to be called only once.