For example:
class Parent{
  Mutex  lock;
  String mydata;
  virtual void DoSomething(){
     for(int i=0;i<10;++i){
       Cout() << mydata << "\n;"
     }
  };
};

class Child1{
  void DoSomething(){
    INTERLOCKED_(lock){
       mydata = "Foo";
       Parent::DoSomething();
    }
  }
};

class Child2{
 void DoSomething(){
    INTERLOCKED_(lock){
       mydata = "Bar";
       Parent::DoSomething();
    }
  }
};

CONSOLE_APP_MAIN{
  Parent * c1 = new Child1();
  Parent * c2 = new Child2();
  
  Thread().Run(callback(&c1, &Parent::DoSomething);
  Thread().Run(callback(&c2, &Parent::DoSomething);

  delete c1;
  delete c2;
}