Re: binary compatibility ABI

[Bryce McKinlay <bryce at mckinlay dot net dot nz>]

On Thursday, Sep 11, 2003, at 14:42 Pacific/Auckland, Bryce McKinlay 
wrote:

> > If you use a separate static field to check for initialization then 
> > you usually
> > have a memory read ordering issue between the flag read and the field 
> > read.
> > However if the value you test for initialization is used to compute 
> > the address
> > of the field itself, you still have a problem on Alpha, but on all 
> > other
> > architectures that we considered, the two reads appear to be ordered.
>
> ... class initialization can have other side effects besides setting 
> the static fields of a class?

Actually, does the new Java memory model make any guarantees here? ie 
consider the following code:

class X
{
  static int a;

  void m()
  {
    System.out.println(Y.s);
    System.out.println(X.a);
  }
}

class Y
{
  static int s;
  static
  {
    Y.s = 55;
    X.a = 25;
  }
}

Presumably, the first println is guaranteed to print '55'? But is the 
second println guaranteed to print '25'?

Regards

Bryce.