Thread safety: exposing "this" via a "static" reference in constructor

Question

please consider:
public class Foo  {
  public static List<Foo> list = new ArrayList<Foo>();
  public int i = 1;
  Foo() {
    Foo.list.add(this);
    i++;
    // ...... other stuff that does not effect "i"
}Exiting, I want "i" to always be 2. But what if a thread got the reference to "this" from the static List before the constructor exited and did:
((Foo) Foo.list.get(0)).i++;Is the only solution a synchronized wrapper for "list"?
Thanks.

Answer 1

A synchronized wrapper is not sufficient:
public static List<Foo> list = Collections.synchronizedList(new ArrayList<Foo>());This is because the list is now thread-safe, but what about the items in it?
Look at your constructor:
Foo.list.add(this);
i++;Another thread could access the list in between the execution of these two lines and see the value of i before i is incremented.