453   // younger), allowing them to resize themselves as appropriate.
 454   virtual void compute_new_size() = 0;
 455 
 456   // Printing
 457   virtual const char* name() const = 0;
 458   virtual const char* short_name() const = 0;
 459 
 460   // Reference Processing accessor
 461   ReferenceProcessor* const ref_processor() { return _ref_processor; }
 462 
 463   // Iteration.
 464 
 465   // Iterate over all the ref-containing fields of all objects in the
 466   // generation, calling "cl.do_oop" on each.
 467   virtual void oop_iterate(OopIterateClosure* cl);
 468 
 469   // Iterate over all objects in the generation, calling "cl.do_object" on
 470   // each.
 471   virtual void object_iterate(ObjectClosure* cl);
 472 
 473   // Iterate over all safe objects in the generation, calling "cl.do_object" on
 474   // each.  An object is safe if its references point to other objects in
 475   // the heap.  This defaults to object_iterate() unless overridden.
 476   virtual void safe_object_iterate(ObjectClosure* cl);
 477 
 478   // Apply "cl->do_oop" to (the address of) all and only all the ref fields
 479   // in the current generation that contain pointers to objects in younger
 480   // generations. Objects allocated since the last "save_marks" call are
 481   // excluded.
 482   virtual void younger_refs_iterate(OopsInGenClosure* cl, uint n_threads) = 0;
 483 
 484   // Inform a generation that it longer contains references to objects
 485   // in any younger generation.    [e.g. Because younger gens are empty,
 486   // clear the card table.]
 487   virtual void clear_remembered_set() { }
 488 
 489   // Inform a generation that some of its objects have moved.  [e.g. The
 490   // generation's spaces were compacted, invalidating the card table.]
 491   virtual void invalidate_remembered_set() { }
 492 
 493   // Block abstraction.
 494 
 495   // Returns the address of the start of the "block" that contains the
 496   // address "addr".  We say "blocks" instead of "object" since some heaps
 497   // may not pack objects densely; a chunk may either be an object or a

 453   // younger), allowing them to resize themselves as appropriate.
 454   virtual void compute_new_size() = 0;
 455 
 456   // Printing
 457   virtual const char* name() const = 0;
 458   virtual const char* short_name() const = 0;
 459 
 460   // Reference Processing accessor
 461   ReferenceProcessor* const ref_processor() { return _ref_processor; }
 462 
 463   // Iteration.
 464 
 465   // Iterate over all the ref-containing fields of all objects in the
 466   // generation, calling "cl.do_oop" on each.
 467   virtual void oop_iterate(OopIterateClosure* cl);
 468 
 469   // Iterate over all objects in the generation, calling "cl.do_object" on
 470   // each.
 471   virtual void object_iterate(ObjectClosure* cl);
 472 





 473   // Apply "cl->do_oop" to (the address of) all and only all the ref fields
 474   // in the current generation that contain pointers to objects in younger
 475   // generations. Objects allocated since the last "save_marks" call are
 476   // excluded.
 477   virtual void younger_refs_iterate(OopsInGenClosure* cl, uint n_threads) = 0;
 478 
 479   // Inform a generation that it longer contains references to objects
 480   // in any younger generation.    [e.g. Because younger gens are empty,
 481   // clear the card table.]
 482   virtual void clear_remembered_set() { }
 483 
 484   // Inform a generation that some of its objects have moved.  [e.g. The
 485   // generation's spaces were compacted, invalidating the card table.]
 486   virtual void invalidate_remembered_set() { }
 487 
 488   // Block abstraction.
 489 
 490   // Returns the address of the start of the "block" that contains the
 491   // address "addr".  We say "blocks" instead of "object" since some heaps
 492   // may not pack objects densely; a chunk may either be an object or a