src/hotspot/share/gc/g1/heapRegionManager.hpp

rev 51649 : version 1
rev 51650 : added comments
rev 52017 : All changes for G1 GC moved from 'combined' repo folder

*** 69,88 ****
  
  class HeapRegionManager: public CHeapObj<mtGC> {
    friend class VMStructs;
    friend class HeapRegionClaimer;
  
    G1HeapRegionTable _regions;
- 
    G1RegionToSpaceMapper* _heap_mapper;
    G1RegionToSpaceMapper* _prev_bitmap_mapper;
    G1RegionToSpaceMapper* _next_bitmap_mapper;
    G1RegionToSpaceMapper* _bot_mapper;
    G1RegionToSpaceMapper* _cardtable_mapper;
    G1RegionToSpaceMapper* _card_counts_mapper;
  
    FreeRegionList _free_list;
  
    // Each bit in this bitmap indicates that the corresponding region is available
    // for allocation.
    CHeapBitMap _available_map;
  
--- 69,91 ----
  
  class HeapRegionManager: public CHeapObj<mtGC> {
    friend class VMStructs;
    friend class HeapRegionClaimer;
  
+   protected:
    G1HeapRegionTable _regions;
    G1RegionToSpaceMapper* _heap_mapper;
+   private:
    G1RegionToSpaceMapper* _prev_bitmap_mapper;
    G1RegionToSpaceMapper* _next_bitmap_mapper;
    G1RegionToSpaceMapper* _bot_mapper;
    G1RegionToSpaceMapper* _cardtable_mapper;
    G1RegionToSpaceMapper* _card_counts_mapper;
  
+   protected:
    FreeRegionList _free_list;
+   private:
  
    // Each bit in this bitmap indicates that the corresponding region is available
    // for allocation.
    CHeapBitMap _available_map;
  
*** 93,107 ****
    uint _allocated_heapregions_length;
  
    HeapWord* heap_bottom() const { return _regions.bottom_address_mapped(); }
    HeapWord* heap_end() const {return _regions.end_address_mapped(); }
  
    void make_regions_available(uint index, uint num_regions = 1, WorkGang* pretouch_gang = NULL);
! 
    // Pass down commit calls to the VirtualSpace.
    void commit_regions(uint index, size_t num_regions = 1, WorkGang* pretouch_gang = NULL);
-   void uncommit_regions(uint index, size_t num_regions = 1);
  
    // Notify other data structures about change in the heap layout.
    void update_committed_space(HeapWord* old_end, HeapWord* new_end);
  
    // Find a contiguous set of empty or uncommitted regions of length num and return
--- 96,111 ----
    uint _allocated_heapregions_length;
  
    HeapWord* heap_bottom() const { return _regions.bottom_address_mapped(); }
    HeapWord* heap_end() const {return _regions.end_address_mapped(); }
  
+   protected:
    void make_regions_available(uint index, uint num_regions = 1, WorkGang* pretouch_gang = NULL);
!   void uncommit_regions(uint index, size_t num_regions = 1);
!   private:
    // Pass down commit calls to the VirtualSpace.
    void commit_regions(uint index, size_t num_regions = 1, WorkGang* pretouch_gang = NULL);
  
    // Notify other data structures about change in the heap layout.
    void update_committed_space(HeapWord* old_end, HeapWord* new_end);
  
    // Find a contiguous set of empty or uncommitted regions of length num and return
*** 115,132 ****
    uint find_unavailable_from_idx(uint start_idx, uint* res_idx) const;
    // Finds the next sequence of empty regions starting from start_idx, going backwards in
    // the heap. Returns the length of the sequence found. If this value is zero, no
    // sequence could be found, otherwise res_idx contains the start index of this range.
    uint find_empty_from_idx_reverse(uint start_idx, uint* res_idx) const;
-   // Allocate a new HeapRegion for the given index.
-   HeapRegion* new_heap_region(uint hrm_index);
  #ifdef ASSERT
  public:
    bool is_free(HeapRegion* hr) const;
! #endif
    // Returns whether the given region is available for allocation.
    bool is_available(uint region) const;
  
   public:
    // Empty constructor, we'll initialize it with the initialize() method.
    HeapRegionManager();
  
--- 119,139 ----
    uint find_unavailable_from_idx(uint start_idx, uint* res_idx) const;
    // Finds the next sequence of empty regions starting from start_idx, going backwards in
    // the heap. Returns the length of the sequence found. If this value is zero, no
    // sequence could be found, otherwise res_idx contains the start index of this range.
    uint find_empty_from_idx_reverse(uint start_idx, uint* res_idx) const;
  #ifdef ASSERT
  public:
    bool is_free(HeapRegion* hr) const;
!   bool is_available(uint region) const;
! #else
    // Returns whether the given region is available for allocation.
+ protected:
    bool is_available(uint region) const;
+ #endif
+   // Allocate a new HeapRegion for the given index.
+   HeapRegion* new_heap_region(uint hrm_index);
  
   public:
    // Empty constructor, we'll initialize it with the initialize() method.
    HeapRegionManager();
  
*** 139,149 ****
  
    // Return the "dummy" region used for G1AllocRegion. This is currently a hardwired
    // new HeapRegion that owns HeapRegion at index 0. Since at the moment we commit
    // the heap from the lowest address, this region (and its associated data
    // structures) are available and we do not need to check further.
!   HeapRegion* get_dummy_region() { return new_heap_region(0); }
  
    // Return the HeapRegion at the given index. Assume that the index
    // is valid.
    inline HeapRegion* at(uint index) const;
  
--- 146,156 ----
  
    // Return the "dummy" region used for G1AllocRegion. This is currently a hardwired
    // new HeapRegion that owns HeapRegion at index 0. Since at the moment we commit
    // the heap from the lowest address, this region (and its associated data
    // structures) are available and we do not need to check further.
!   virtual HeapRegion* get_dummy_region() { return new_heap_region(0); }
  
    // Return the HeapRegion at the given index. Assume that the index
    // is valid.
    inline HeapRegion* at(uint index) const;
  
*** 161,171 ****
    // Insert the given region list into the global free region list.
    void insert_list_into_free_list(FreeRegionList* list) {
      _free_list.add_ordered(list);
    }
  
!   HeapRegion* allocate_free_region(bool is_old) {
      HeapRegion* hr = _free_list.remove_region(is_old);
  
      if (hr != NULL) {
        assert(hr->next() == NULL, "Single region should not have next");
        assert(is_available(hr->hrm_index()), "Must be committed");
--- 168,178 ----
    // Insert the given region list into the global free region list.
    void insert_list_into_free_list(FreeRegionList* list) {
      _free_list.add_ordered(list);
    }
  
!   virtual HeapRegion* allocate_free_region(bool is_old) {
      HeapRegion* hr = _free_list.remove_region(is_old);
  
      if (hr != NULL) {
        assert(hr->next() == NULL, "Single region should not have next");
        assert(is_available(hr->hrm_index()), "Must be committed");
*** 196,233 ****
    uint length() const { return _num_committed; }
  
    // Return the maximum number of regions in the heap.
    uint max_length() const { return (uint)_regions.length(); }
  
    MemoryUsage get_auxiliary_data_memory_usage() const;
  
    MemRegion reserved() const { return MemRegion(heap_bottom(), heap_end()); }
  
    // Expand the sequence to reflect that the heap has grown. Either create new
    // HeapRegions, or re-use existing ones. Returns the number of regions the
    // sequence was expanded by. If a HeapRegion allocation fails, the resulting
    // number of regions might be smaller than what's desired.
!   uint expand_by(uint num_regions, WorkGang* pretouch_workers);
  
    // Makes sure that the regions from start to start+num_regions-1 are available
    // for allocation. Returns the number of regions that were committed to achieve
    // this.
!   uint expand_at(uint start, uint num_regions, WorkGang* pretouch_workers);
  
    // Find a contiguous set of empty regions of length num. Returns the start index of
    // that set, or G1_NO_HRM_INDEX.
!   uint find_contiguous_only_empty(size_t num) { return find_contiguous(num, true); }
    // Find a contiguous set of empty or unavailable regions of length num. Returns the
    // start index of that set, or G1_NO_HRM_INDEX.
!   uint find_contiguous_empty_or_unavailable(size_t num) { return find_contiguous(num, false); }
  
    HeapRegion* next_region_in_heap(const HeapRegion* r) const;
  
    // Find the highest free or uncommitted region in the reserved heap,
    // and if uncommitted, commit it. If none are available, return G1_NO_HRM_INDEX.
    // Set the 'expanded' boolean true if a new region was committed.
!   uint find_highest_free(bool* expanded);
  
    // Allocate the regions that contain the address range specified, committing the
    // regions if necessary. Return false if any of the regions is already committed
    // and not free, and return the number of regions newly committed in commit_count.
    bool allocate_containing_regions(MemRegion range, size_t* commit_count, WorkGang* pretouch_workers);
--- 203,243 ----
    uint length() const { return _num_committed; }
  
    // Return the maximum number of regions in the heap.
    uint max_length() const { return (uint)_regions.length(); }
    
+   // Return maximum number of regions that heap can expand to.
+   virtual uint max_expandable_length() const { return (uint)_regions.length(); }
+ 
    MemoryUsage get_auxiliary_data_memory_usage() const;
  
    MemRegion reserved() const { return MemRegion(heap_bottom(), heap_end()); }
  
    // Expand the sequence to reflect that the heap has grown. Either create new
    // HeapRegions, or re-use existing ones. Returns the number of regions the
    // sequence was expanded by. If a HeapRegion allocation fails, the resulting
    // number of regions might be smaller than what's desired.
!   virtual uint expand_by(uint num_regions, WorkGang* pretouch_workers);
  
    // Makes sure that the regions from start to start+num_regions-1 are available
    // for allocation. Returns the number of regions that were committed to achieve
    // this.
!   virtual uint expand_at(uint start, uint num_regions, WorkGang* pretouch_workers);
  
    // Find a contiguous set of empty regions of length num. Returns the start index of
    // that set, or G1_NO_HRM_INDEX.
!   virtual uint find_contiguous_only_empty(size_t num) { return find_contiguous(num, true); }
    // Find a contiguous set of empty or unavailable regions of length num. Returns the
    // start index of that set, or G1_NO_HRM_INDEX.
!   virtual uint find_contiguous_empty_or_unavailable(size_t num) { return find_contiguous(num, false); }
  
    HeapRegion* next_region_in_heap(const HeapRegion* r) const;
  
    // Find the highest free or uncommitted region in the reserved heap,
    // and if uncommitted, commit it. If none are available, return G1_NO_HRM_INDEX.
    // Set the 'expanded' boolean true if a new region was committed.
!   virtual uint find_highest_free(bool* expanded);
  
    // Allocate the regions that contain the address range specified, committing the
    // regions if necessary. Return false if any of the regions is already committed
    // and not free, and return the number of regions newly committed in commit_count.
    bool allocate_containing_regions(MemRegion range, size_t* commit_count, WorkGang* pretouch_workers);
*** 238,254 ****
  
    void par_iterate(HeapRegionClosure* blk, HeapRegionClaimer* hrclaimer, const uint start_index) const;
  
    // Uncommit up to num_regions_to_remove regions that are completely free.
    // Return the actual number of uncommitted regions.
!   uint shrink_by(uint num_regions_to_remove);
  
    // Uncommit a number of regions starting at the specified index, which must be available,
    // empty, and free.
    void shrink_at(uint index, size_t num_regions);
  
!   void verify();
  
    // Do some sanity checking.
    void verify_optional() PRODUCT_RETURN;
  };
  
--- 248,264 ----
  
    void par_iterate(HeapRegionClosure* blk, HeapRegionClaimer* hrclaimer, const uint start_index) const;
  
    // Uncommit up to num_regions_to_remove regions that are completely free.
    // Return the actual number of uncommitted regions.
!   virtual uint shrink_by(uint num_regions_to_remove);
  
    // Uncommit a number of regions starting at the specified index, which must be available,
    // empty, and free.
    void shrink_at(uint index, size_t num_regions);
  
!   virtual void verify();
  
    // Do some sanity checking.
    void verify_optional() PRODUCT_RETURN;
  };