How can I use the volatile keyword in Java correctly?

Question

Say I have two threads and an object. One thread assigns the object:

public void assign(MyObject o) {
    myObject = o;
}

Another thread uses t

Answer 1

Declaring a volatile Java variable means:

• The value of this variable will never be cached thread-locally
• Access to the variable acts as though it is enclosed in a synchronized block

The typical and most common use of volatile is :

public class StoppableThread extends Thread {
  private volatile boolean stop = false;

  public void run() {
    while (!stop) {
      // do work 
    }
  }

  public void stopWork() {
    stop = true;
  }
}