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How to get AtomicReferenceFieldUpdater with scala companion object?

If I have a linked node in some kind of collection structure, I don't want its next link to be AtomicReference (I need atomic CAS update), so I declare it as:

@volatile var next: Node[A] = _n

and then in the companion declare:

val updater = AtomicReferenceFieldUpdater.newUpdater(classOf[Link[_]], classOf[Node[_]], "n")
def cas[A](target: Link[A], old: Node[A], newNode: Node[A]) = updater.compareAndSet(target, old, newNode);

At runtime, I get the following error:

java.lang.RuntimeException: java.lang.IllegalAccessException: 
  Class concurrent.Link$ can not access a member of class concurrent.Link
  with modifiers "private volatile"
    at java.util.concurrent.atomic.AtomicReferenceFieldUpdater$AtomicReferenceFieldUpdaterImpl.<init>(AtomicReferenceFieldUpdater.java:189)
    at java.util.concurrent.atomic.AtomicReferenceFieldUpdater.newUpdater(AtomicReferenceFieldUpdater.java:65)
    at concurrent.Link$.<init>(Link.scala:106)
    ...

So, at run time, the companion object is concurrent.Link$not concurrent.Link, and the other class cannot access the private member of the other.

BUT if I javap -p concurrent.Link

I get:

Compiled from "Link.scala"
public final class concurrent.Link implements concurrent.Node,scala.ScalaObject,scala.Product,java.io.Serializable{
private final java.lang.Object value;
private volatile com.atlassian.util.scala.concurrent.Node node;
public static final boolean cas(com.atlassian.util.scala.concurrent.Link, com.atlassian.util.scala.concurrent.Node, com.atlassian.util.scala.concurrent.Node);
public static final java.util.concurrent.atomic.AtomicReferenceFieldUpdater updater();

So, I have everything except the static instance AtomicReferenceFieldUpdaterdeclared in my class Link.

The question is how to get an instance AtomicReferenceFieldUpdaterin Scala that points to volatile var?

, , - Java ( AbstractLink node AtomicReferenceFieldUpdater) , .

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Hard. Scala , .

, Java .

Java:

public class Base {
   volatile Object field = null;
}

Scala :

class Cls extends Base {
  val updater = AtomicReferenceFieldUpdater.newUpdater(classOf[Base[_]], classOf[Object[_]], "field")
  def cas[A](old: Object, n: Object) = updater.compareAndSet(this, old, n);
}

.

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