trjhtr

Here is a class which I have written to create a simple Stack data structure which can be shared across multiple threads.

It's a simple LIFO which has 2 operations: one to push onto the top of the stack and the other one to pop from the top of the stack.

Please help me to find any issues with it.

package com.thread.test;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.locks.ReentrantReadWriteLock;

public class ThreadSafeStack<T> 

 private List<T> list;
 private ReentrantReadWriteLock lock;

 public ThreadSafeStack() 
 this.list = new ArrayList<T>();
 lock = new ReentrantReadWriteLock();
 

 public T pop() 
 try 
 lock.writeLock().lock();
 if(!list.isEmpty()) 
 return list.remove(list.size()-1);
 
 finally 
 System.out.println("In finally");
 lock.writeLock().unlock();
 
 return null;
 

 public boolean push(T t) 
 try 
 lock.writeLock().lock();
 return list.add(t);

 
 finally 
 lock.writeLock().unlock();
 
 

It is unclear what you are trying to achieve but one of the below implementations should suit your requirements:

• ConcurrentLinkedDeque since 1.7




• BlockingDeque since 1.6

(If you're just trying to reinvent the wheel for educational purposes, I will recommend reading the source code of above mentioned java classes.)