"Island of isolation" of Garbage Collection

Question

Could anyone please explain the concept of Island of isolation of Garbage Collection?

Answer 1

Object A references object B. Object B references object A. Neither object A nor object B is referenced by any other object. That's an island of isolation.

Basically, an island of isolation is a group of objects that reference each other but they are not referenced by any active object in the application. Strictly speaking, even a single unreferenced object is an island of isolation too.

Edit from Comment:

class A {    B myB;  }  class B {     A myA;  }   /* later */   A a = new A();  B b = new B();   a.b = b;  b.a = a;