Page History

class BankAccount implements Comparable {
  private int balanceAmount;  // Total amount in bank account	 
  private final Object lock;

  //private otherfinal fields,long whichid; can// helpunique makefor this class Comparable
each BankAccount
  publicprivate intstatic compareTo(BankAccount ba) {
    long NextID = 0; // comparenext bank accounts
  }
unused id

  private BankAccount(int balance) {
    this.balanceAmount = balance;
    this.lock = new Object();
    this.id = this.NextID++;
  }


  public int compareTo(BankAccount ba) {
    if (this.id < ba.id) {
      return -1;
    }
    if (this.id > ba.id) {
      return 1;
    }
    return 0;
  }


  // Deposits the amount from this object instance to BankAccount instance argument ba 
  private void depositAllAmount(BankAccount ba) {
    BankAccount former, latter;
    if (compareTo(ba) < 0) {
      former = this;
      latter = ba;
    } else {
      former = ba;
      latter = this;
    }
    synchronized (former) {
      synchronized (latter) {
        ba.balanceAmount += this.balanceAmount;
        this.balanceAmount = 0; // withdraw all amount from this instance
        ba.displayAllAmount(); // Display the new balanceAmount in ba (may cause deadlock)
      } 
    }
  }
 
  private synchronized void displayAllAmount() {
    System.out.println(balanceAmount);
  }

  public static void initiateTransfer(final BankAccount first, final BankAccount second) {
    Thread t = new Thread(new Runnable() {
      public void run() {
        first.depositAllAmount(second);
      }
    });
    t.start();
  }
}