Question

For thread-safety reasons it is argumented:

Do not allow the this reference to escape during construction.

But is this always an issue and should be avoided by using newInstance() methods? Inside my model class I have a TableModel which should be instantiated, within the model class, but which also requires a reference to the model class:

public class MainModel {

   TableModel tableMode;

   public MainModel() {
      tableModel = new MyTableModel(this);
   }
}

If the constructor does not use this right away is it then safe or should it be avoided in any means?

Answer 1

If nothing in the MyTableModel is going to do anything in other threads etc – or copy the variable to some other shared data, such as a static variable – then it’s safe.

Of course, if MyTableModel starts calling methods on the MainModel reference within its constructor, then it’ll be calling them on a not-completely-initialized-yet object, which can cause issues – but that’s not really threading related.

I blogged a bit more on this a while ago.