Initialisation seems fine to me, can't figure out why the compiler doesn't like that.

Question about the task

ReentrantReadWriteLock

Java Multithreading, Level 8, Lesson 10

Under discussion

I tried at the initialization and also tried in the constructor without success

public ReadWriteMap(LinkedHashMap<K, V> map) {
       this.map = map;
       readLock = lock.readLock();
       writeLock = lock.writeLock();
   }

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.

P.S. For Map to operate properly in a multithreaded environment, it's preferable to use a standard implementation, such as ConcurrentHashMap from the java.util.concurrent package. But sometimes you need to work with another type of Map, for example, a LinkedHashMap, and then the proposed solution would be perfect.

Requirements:

The readLock field must be initialized using the lock object's readLock method.
The writeLock field must be initialized using the lock object's writeLock method.
The writeLock object's lock method must be called in the put method.
The readLock object's lock method must be called in the get method.
The writeLock object's unlock method must be called in the finally block in the put method.
The readLock object's unlock method must be called in the finally block in the get method.

package com.codegym.task.task28.task2811; /* ReentrantReadWriteLock */ import java.util.LinkedHashMap; public class Solution { public static void main(String[] args) { ReadWriteMap<Integer, String> linkedSafeMap = new ReadWriteMap<Integer, String>(new LinkedHashMap<>()); } }

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Jonas

Level 41 , Vilnius, Lithuania

2 June 2020, 18:26

My initialization was same and it passed, however my methods were slightly different: 1. In constructor I passed Map<K, V> instead of LinkedHashMap<K, V> map 2. In methods put and get I put readLock.lock() and writeLock.lock() inside the try-catch block Reply if it worked

brus5

Level 41 , Dąbrowa Górnicza, Poland

31 July 2020, 07:42

Yes, I've changed on LinkedHashMap also, and it's generated the problem with validation.