519   // generation's spaces were compacted, invalidating the card table.]
 520   virtual void invalidate_remembered_set() { }
 521 
 522   // Block abstraction.
 523 
 524   // Returns the address of the start of the "block" that contains the
 525   // address "addr".  We say "blocks" instead of "object" since some heaps
 526   // may not pack objects densely; a chunk may either be an object or a
 527   // non-object.
 528   virtual HeapWord* block_start(const void* addr) const;
 529 
 530   // Requires "addr" to be the start of a chunk, and returns its size.
 531   // "addr + size" is required to be the start of a new chunk, or the end
 532   // of the active area of the heap.
 533   virtual size_t block_size(const HeapWord* addr) const ;
 534 
 535   // Requires "addr" to be the start of a block, and returns "TRUE" iff
 536   // the block is an object.
 537   virtual bool block_is_obj(const HeapWord* addr) const;
 538 
 539 
 540   // PrintGC, PrintGCDetails support
 541   void print_heap_change(size_t prev_used) const;
 542 
 543   // PrintHeapAtGC support
 544   virtual void print() const;
 545   virtual void print_on(outputStream* st) const;
 546 
 547   virtual void verify() = 0;
 548 
 549   struct StatRecord {
 550     int invocations;
 551     elapsedTimer accumulated_time;
 552     StatRecord() :
 553       invocations(0),
 554       accumulated_time(elapsedTimer()) {}
 555   };
 556 private:
 557   StatRecord _stat_record;
 558 public:
 559   StatRecord* stat_record() { return &_stat_record; }
 560 
 561   virtual void print_summary_info();
 562   virtual void print_summary_info_on(outputStream* st);
 563 

 519   // generation's spaces were compacted, invalidating the card table.]
 520   virtual void invalidate_remembered_set() { }
 521 
 522   // Block abstraction.
 523 
 524   // Returns the address of the start of the "block" that contains the
 525   // address "addr".  We say "blocks" instead of "object" since some heaps
 526   // may not pack objects densely; a chunk may either be an object or a
 527   // non-object.
 528   virtual HeapWord* block_start(const void* addr) const;
 529 
 530   // Requires "addr" to be the start of a chunk, and returns its size.
 531   // "addr + size" is required to be the start of a new chunk, or the end
 532   // of the active area of the heap.
 533   virtual size_t block_size(const HeapWord* addr) const ;
 534 
 535   // Requires "addr" to be the start of a block, and returns "TRUE" iff
 536   // the block is an object.
 537   virtual bool block_is_obj(const HeapWord* addr) const;
 538 


 539   void print_heap_change(size_t prev_used) const;
 540 

 541   virtual void print() const;
 542   virtual void print_on(outputStream* st) const;
 543 
 544   virtual void verify() = 0;
 545 
 546   struct StatRecord {
 547     int invocations;
 548     elapsedTimer accumulated_time;
 549     StatRecord() :
 550       invocations(0),
 551       accumulated_time(elapsedTimer()) {}
 552   };
 553 private:
 554   StatRecord _stat_record;
 555 public:
 556   StatRecord* stat_record() { return &_stat_record; }
 557 
 558   virtual void print_summary_info();
 559   virtual void print_summary_info_on(outputStream* st);
 560