jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/heapRegionManager.hpp@a8ea2f110d87 (annotated)

src/share/vm/gc_implementation/g1/heapRegionManager.hpp@a8ea2f110d87 (annotated)

src/share/vm/gc_implementation/g1/heapRegionManager.hpp

Tue, 26 Aug 2014 09:36:53 +0200

author: tschatzl
date: Tue, 26 Aug 2014 09:36:53 +0200
changeset 7091: a8ea2f110d87
parent 7051: src/share/vm/gc_implementation/g1/heapRegionSeq.hpp@1f1d373cd044
child 7535: 7ae4e26cb1e0
child 7835: e5406a79ae90
permissions: -rw-r--r--

8054819: Rename HeapRegionSeq to HeapRegionManager
Reviewed-by: jwilhelm, jmasa

 /*
  * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONMANAGER_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONMANAGER_HPP
 #include "gc_implementation/g1/g1BiasedArray.hpp"
 #include "gc_implementation/g1/g1RegionToSpaceMapper.hpp"
 #include "gc_implementation/g1/heapRegionSet.hpp"
 class HeapRegion;
 class HeapRegionClosure;
 class FreeRegionList;
 class G1HeapRegionTable : public G1BiasedMappedArray<HeapRegion*> {
  protected:
   virtual HeapRegion* default_value() const { return NULL; }
 };
 // This class keeps track of the actual heap memory, auxiliary data
 // and its metadata (i.e., HeapRegion instances) and the list of free regions.
 //
 // This allows maximum flexibility for deciding what to commit or uncommit given
 // a request from outside.
 //
 // HeapRegions are kept in the _regions array in address order. A region's
 // index in the array corresponds to its index in the heap (i.e., 0 is the
 // region at the bottom of the heap, 1 is the one after it, etc.). Two
 // regions that are consecutive in the array should also be adjacent in the
 // address space (i.e., region(i).end() == region(i+1).bottom().
 //
 // We create a HeapRegion when we commit the region's address space
 // for the first time. When we uncommit the address space of a
 // region we retain the HeapRegion to be able to re-use it in the
 // future (in case we recommit it).
 //
 // We keep track of three lengths:
 //
 // * _num_committed (returned by length()) is the number of currently
 //   committed regions. These may not be contiguous.
 // * _allocated_heapregions_length (not exposed outside this class) is the
 //   number of regions+1 for which we have HeapRegions.
 // * max_length() returns the maximum number of regions the heap can have.
 //
 class HeapRegionManager: public CHeapObj<mtGC> {
   friend class VMStructs;
   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.
   BitMap _available_map;
    // The number of regions committed in the heap.
   uint _num_committed;
   // Internal only. The highest heap region +1 we allocated a HeapRegion instance for.
   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);
   // Pass down commit calls to the VirtualSpace.
   void commit_regions(uint index, size_t num_regions = 1);
   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);
   // Calculate the starting region for each worker during parallel iteration so
   // that they do not all start from the same region.
   uint start_region_for_worker(uint worker_i, uint num_workers, uint num_regions) const;
   // Find a contiguous set of empty or uncommitted regions of length num and return
   // the index of the first region or G1_NO_HRM_INDEX if the search was unsuccessful.
   // If only_empty is true, only empty regions are considered.
   // Searches from bottom to top of the heap, doing a first-fit.
   uint find_contiguous(size_t num, bool only_empty);
   // Finds the next sequence of unavailable regions starting from start_idx. Returns the
   // length of the sequence found. If this result is zero, no such sequence could be found,
   // otherwise res_idx indicates the start index of these regions.
   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() : _regions(), _heap_mapper(NULL), _num_committed(0),
                     _next_bitmap_mapper(NULL), _prev_bitmap_mapper(NULL), _bot_mapper(NULL),
                     _allocated_heapregions_length(0), _available_map(),
                     _free_list("Free list", new MasterFreeRegionListMtSafeChecker())
   { }
   void initialize(G1RegionToSpaceMapper* heap_storage,
                   G1RegionToSpaceMapper* prev_bitmap,
                   G1RegionToSpaceMapper* next_bitmap,
                   G1RegionToSpaceMapper* bot,
                   G1RegionToSpaceMapper* cardtable,
                   G1RegionToSpaceMapper* card_counts);
   // 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;
   // If addr is within the committed space return its corresponding
   // HeapRegion, otherwise return NULL.
   inline HeapRegion* addr_to_region(HeapWord* addr) const;
   // Insert the given region into the free region list.
   inline void insert_into_free_list(HeapRegion* hr);
   // 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");
     }
     return hr;
   }
   inline void allocate_free_regions_starting_at(uint first, uint num_regions);
   // Remove all regions from the free list.
   void remove_all_free_regions() {
     _free_list.remove_all();
   }
   // Return the number of committed free regions in the heap.
   uint num_free_regions() const {
     return _free_list.length();
   }
   size_t total_capacity_bytes() const {
     return num_free_regions() * HeapRegion::GrainBytes;
   }
   // Return the number of available (uncommitted) regions.
   uint available() const { return max_length() - length(); }
   // Return the number of regions that have been committed in the heap.
   uint length() const { return _num_committed; }
   // Return the maximum number of regions in the heap.
   uint max_length() const { return (uint)_regions.length(); }
   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);
   // 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);
   // 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;
   // Apply blk->doHeapRegion() on all committed regions in address order,
   // terminating the iteration early if doHeapRegion() returns true.
   void iterate(HeapRegionClosure* blk) const;
   void par_iterate(HeapRegionClosure* blk, uint worker_id, uint no_of_par_workers, jint claim_value) 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);
   void verify();
   // Do some sanity checking.
   void verify_optional() PRODUCT_RETURN;
 };
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONMANAGER_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/heapRegionManager.hpp@a8ea2f110d87 (annotated)

src/share/vm/gc_implementation/g1/heapRegionManager.hpp