This is done in Eclipse. Language is Java.

Use SwingWorker to implement the Account Balance scenerio with GUI.

Concurrency in Swing:

https://docs.oracle.com/javase/tutorial/uiswing/concurrency/index.html

javax.swing.SwingWorker class

Type Parameters:

T - the result type returned by this SwingWroker's doInBackground and get methods

V - the type used for carrying out intermediate results by this SwingWorker's publish and process methods

Below is the code done in class, referenced at the beginning Account balance.

import java.util.Random;

import java.util.concurrent.locks.Lock;

import java.util.concurrent.locks.ReentrantLock;

public class ThreadRun {

//1. create 2 accounts

private Account account1 = new Account();

private Account account2 = new Account();

//in order to fix the multithreading issue, use lock

private Lock lock1 = new ReentrantLock();

private Lock lock2 = new ReentrantLock();

//in order to solve the deadlock issue, can create a method

//put all in one method...

private void acquireLocks(Lock firstLock, Lock secondLock) throws InterruptedException {

//use tryLock() method - a method in ReentrantLock()

//it returns immediately and true if it has lock

while(true) {

//try to acquire lock

boolean gotFirstLock = false;

boolean gotSecondLock = false;

try {

gotFirstLock = firstLock.tryLock();

gotSecondLock = secondLock.tryLock();

} finally {

if(gotFirstLock && gotSecondLock) {

return;

}

if(gotFirstLock) {

firstLock.unlock();

}

if(gotSecondLock) {

secondLock.unlock();

}

}

//if fail to acquire lock, do this

Thread.sleep(1);

}

}

public void FirstThread() throws InterruptedException{

Random random = new Random();

//let's make a scenario of transferring some money from acc1 --> acc2

for(int i=0;i<10000;i++) {

//lock1.lock();

//lock2.lock();

acquireLocks(lock1,lock2);

try {

Account.transfer(account1, account2, random.nextInt(100));

} finally {

lock1.unlock();

lock2.unlock();

}

}

}

public void SecondThread() throws InterruptedException{

Random random = new Random();

//let's make a scenario of transferring some money from acc2 --> acc1

for(int i=0;i<10000;i++) {

//lock1.lock();

//lock2.lock();

acquireLocks(lock2, lock1);

try {

Account.transfer(account2, account1, random.nextInt(100));

} finally {

lock2.unlock();

lock1.unlock(); //unlock order doesn't really matter

}

}

}

public void finished() {

System.out.println("Account1 balance is " + account1.getBalance());

System.out.println("Account2 balance is " + account2.getBalance());

System.out.println("Total balance is " + (account1.getBalance() + account2.getBalance()));

}

}