How to implement multi threading without using Java's synchronization

Question

I have a shared Object called "tradeObj" whose attributes are "Price" and "Quantity".
Thread1 is going to change the price and Thread2 is going to change the quantity but not stepping on each other's update.
Because of the cost of synchronization, I dont want to use "Synchronize", but still want to make sure both threads make their update in a proper manner.
Any ideas?

Answer 1

Soph wrote:
I have a shared Object called "tradeObj" whose attributes are "Price" and "Quantity".
Thread1 is going to change the price and Thread2 is going to change the quantity but not stepping on each other's update.given above I would guess [your interviewer|http://forums.sun.com/thread.jspa?messageID=10976469#10976469|interview] had in mind reducing locks contention (google for "java concurrency locks granularity" or "java concurrency locks contention" if you're interested)
// disclaimer: I didn't test this code with compiler
class TradeObj {
  private int price, quantity;
  // locks
  private final Object priceLock = new Object();
  private final Object quantityLock = new Object();
  public int getPrice() {
    synchronized (priceLock) { return price; }
  public void setPrice(int price) {
    synchronized (priceLock) { this.price = price; }
  public int getQuantity() {
    synchronized (quantityLock) { return quantity; }
  public void setQuantity(int quantity) {
    synchronized (quantityLock) { this.quantity = quantity; }
Because of the cost of synchronization, I dont want to use "Synchronize", but still want to make sure both threads make their update in a proper manner.what you want above doesn't make much sense to me sorry
Any ideas?Edited by: gnat on Apr 23, 2010 9:44 AM