ysr@777: /*
azakharov@7835:  * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
ysr@777:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777:  *
ysr@777:  * This code is free software; you can redistribute it and/or modify it
ysr@777:  * under the terms of the GNU General Public License version 2 only, as
ysr@777:  * published by the Free Software Foundation.
ysr@777:  *
ysr@777:  * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ysr@777:  * version 2 for more details (a copy is included in the LICENSE file that
ysr@777:  * accompanied this code).
ysr@777:  *
ysr@777:  * You should have received a copy of the GNU General Public License version
ysr@777:  * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
ysr@777:  *
ysr@777:  */
ysr@777: 
tschatzl@7091: #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONMANAGER_HPP
tschatzl@7091: #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONMANAGER_HPP
stefank@2314: 
tschatzl@5773: #include "gc_implementation/g1/g1BiasedArray.hpp"
tschatzl@7051: #include "gc_implementation/g1/g1RegionToSpaceMapper.hpp"
tschatzl@7050: #include "gc_implementation/g1/heapRegionSet.hpp"
azakharov@7835: #include "services/memoryUsage.hpp"
tschatzl@5773: 
ysr@777: class HeapRegion;
ysr@777: class HeapRegionClosure;
tonyp@2963: class FreeRegionList;
tonyp@2963: 
tschatzl@5773: class G1HeapRegionTable : public G1BiasedMappedArray<HeapRegion*> {
tschatzl@5773:  protected:
tschatzl@7050:   virtual HeapRegion* default_value() const { return NULL; }
tschatzl@5773: };
tschatzl@5773: 
tschatzl@7051: // This class keeps track of the actual heap memory, auxiliary data
tschatzl@7051: // and its metadata (i.e., HeapRegion instances) and the list of free regions.
tschatzl@7051: //
tschatzl@7051: // This allows maximum flexibility for deciding what to commit or uncommit given
tschatzl@7051: // a request from outside.
tschatzl@7051: //
tschatzl@7051: // HeapRegions are kept in the _regions array in address order. A region's
tschatzl@7051: // index in the array corresponds to its index in the heap (i.e., 0 is the
tschatzl@7051: // region at the bottom of the heap, 1 is the one after it, etc.). Two
tschatzl@7051: // regions that are consecutive in the array should also be adjacent in the
tschatzl@7051: // address space (i.e., region(i).end() == region(i+1).bottom().
tonyp@2963: //
tonyp@2963: // We create a HeapRegion when we commit the region's address space
tonyp@2963: // for the first time. When we uncommit the address space of a
tonyp@2963: // region we retain the HeapRegion to be able to re-use it in the
tonyp@2963: // future (in case we recommit it).
tonyp@2963: //
tonyp@2963: // We keep track of three lengths:
tonyp@2963: //
tschatzl@7051: // * _num_committed (returned by length()) is the number of currently
tschatzl@7051: //   committed regions. These may not be contiguous.
tschatzl@7051: // * _allocated_heapregions_length (not exposed outside this class) is the
tschatzl@7051: //   number of regions+1 for which we have HeapRegions.
tschatzl@5773: // * max_length() returns the maximum number of regions the heap can have.
tonyp@2963: //
ysr@777: 
tschatzl@7091: class HeapRegionManager: public CHeapObj<mtGC> {
tonyp@3168:   friend class VMStructs;
ysr@777: 
tschatzl@5773:   G1HeapRegionTable _regions;
ysr@777: 
tschatzl@7051:   G1RegionToSpaceMapper* _heap_mapper;
tschatzl@7051:   G1RegionToSpaceMapper* _prev_bitmap_mapper;
tschatzl@7051:   G1RegionToSpaceMapper* _next_bitmap_mapper;
tschatzl@7051:   G1RegionToSpaceMapper* _bot_mapper;
tschatzl@7051:   G1RegionToSpaceMapper* _cardtable_mapper;
tschatzl@7051:   G1RegionToSpaceMapper* _card_counts_mapper;
tonyp@2963: 
tschatzl@7050:   FreeRegionList _free_list;
tonyp@2963: 
tschatzl@7051:   // Each bit in this bitmap indicates that the corresponding region is available
tschatzl@7051:   // for allocation.
tschatzl@7051:   BitMap _available_map;
tschatzl@7051: 
tschatzl@7050:    // The number of regions committed in the heap.
tschatzl@7050:   uint _num_committed;
tonyp@2963: 
tschatzl@7050:   // Internal only. The highest heap region +1 we allocated a HeapRegion instance for.
tschatzl@7050:   uint _allocated_heapregions_length;
tonyp@2963: 
tschatzl@7050:    HeapWord* heap_bottom() const { return _regions.bottom_address_mapped(); }
tschatzl@7050:    HeapWord* heap_end() const {return _regions.end_address_mapped(); }
tonyp@2963: 
tschatzl@7050:   void make_regions_available(uint index, uint num_regions = 1);
brutisso@5074: 
tschatzl@7050:   // Pass down commit calls to the VirtualSpace.
tschatzl@7050:   void commit_regions(uint index, size_t num_regions = 1);
tschatzl@7050:   void uncommit_regions(uint index, size_t num_regions = 1);
ysr@777: 
tschatzl@7050:   // Notify other data structures about change in the heap layout.
tschatzl@7050:   void update_committed_space(HeapWord* old_end, HeapWord* new_end);
tschatzl@7050:   // Calculate the starting region for each worker during parallel iteration so
tschatzl@7050:   // that they do not all start from the same region.
tschatzl@7050:   uint start_region_for_worker(uint worker_i, uint num_workers, uint num_regions) const;
tschatzl@5773: 
tschatzl@7051:   // Find a contiguous set of empty or uncommitted regions of length num and return
tschatzl@7091:   // the index of the first region or G1_NO_HRM_INDEX if the search was unsuccessful.
tschatzl@7051:   // If only_empty is true, only empty regions are considered.
tschatzl@7051:   // Searches from bottom to top of the heap, doing a first-fit.
tschatzl@7051:   uint find_contiguous(size_t num, bool only_empty);
tschatzl@7050:   // Finds the next sequence of unavailable regions starting from start_idx. Returns the
tschatzl@7050:   // length of the sequence found. If this result is zero, no such sequence could be found,
tschatzl@7050:   // otherwise res_idx indicates the start index of these regions.
tschatzl@7050:   uint find_unavailable_from_idx(uint start_idx, uint* res_idx) const;
tschatzl@7050:   // Finds the next sequence of empty regions starting from start_idx, going backwards in
tschatzl@7050:   // the heap. Returns the length of the sequence found. If this value is zero, no
tschatzl@7050:   // sequence could be found, otherwise res_idx contains the start index of this range.
tschatzl@7050:   uint find_empty_from_idx_reverse(uint start_idx, uint* res_idx) const;
tschatzl@7051:   // Allocate a new HeapRegion for the given index.
tschatzl@7091:   HeapRegion* new_heap_region(uint hrm_index);
tschatzl@7050: #ifdef ASSERT
tschatzl@7050: public:
tschatzl@7050:   bool is_free(HeapRegion* hr) const;
tschatzl@7050: #endif
tschatzl@7050:   // Returns whether the given region is available for allocation.
tschatzl@7050:   bool is_available(uint region) const;
ysr@777: 
tschatzl@7091:  public:
tschatzl@7091:   // Empty constructor, we'll initialize it with the initialize() method.
tschatzl@7091:   HeapRegionManager() : _regions(), _heap_mapper(NULL), _num_committed(0),
tschatzl@7051:                     _next_bitmap_mapper(NULL), _prev_bitmap_mapper(NULL), _bot_mapper(NULL),
tschatzl@7051:                     _allocated_heapregions_length(0), _available_map(),
tschatzl@7051:                     _free_list("Free list", new MasterFreeRegionListMtSafeChecker())
tschatzl@7050:   { }
tschatzl@7050: 
tschatzl@7051:   void initialize(G1RegionToSpaceMapper* heap_storage,
tschatzl@7051:                   G1RegionToSpaceMapper* prev_bitmap,
tschatzl@7051:                   G1RegionToSpaceMapper* next_bitmap,
tschatzl@7051:                   G1RegionToSpaceMapper* bot,
tschatzl@7051:                   G1RegionToSpaceMapper* cardtable,
tschatzl@7051:                   G1RegionToSpaceMapper* card_counts);
tschatzl@7050: 
tschatzl@7050:   // Return the "dummy" region used for G1AllocRegion. This is currently a hardwired
tschatzl@7050:   // new HeapRegion that owns HeapRegion at index 0. Since at the moment we commit
tschatzl@7050:   // the heap from the lowest address, this region (and its associated data
tschatzl@7050:   // structures) are available and we do not need to check further.
tschatzl@7050:   HeapRegion* get_dummy_region() { return new_heap_region(0); }
ysr@777: 
tonyp@2963:   // Return the HeapRegion at the given index. Assume that the index
tonyp@2963:   // is valid.
tonyp@3713:   inline HeapRegion* at(uint index) const;
ysr@777: 
tonyp@2963:   // If addr is within the committed space return its corresponding
tonyp@2963:   // HeapRegion, otherwise return NULL.
tonyp@2963:   inline HeapRegion* addr_to_region(HeapWord* addr) const;
ysr@777: 
tschatzl@7050:   // Insert the given region into the free region list.
tschatzl@7050:   inline void insert_into_free_list(HeapRegion* hr);
tschatzl@7050: 
tschatzl@7050:   // Insert the given region list into the global free region list.
tschatzl@7050:   void insert_list_into_free_list(FreeRegionList* list) {
tschatzl@7050:     _free_list.add_ordered(list);
tschatzl@7050:   }
tschatzl@7050: 
tschatzl@7050:   HeapRegion* allocate_free_region(bool is_old) {
tschatzl@7050:     HeapRegion* hr = _free_list.remove_region(is_old);
tschatzl@7050: 
tschatzl@7050:     if (hr != NULL) {
tschatzl@7050:       assert(hr->next() == NULL, "Single region should not have next");
tschatzl@7091:       assert(is_available(hr->hrm_index()), "Must be committed");
tschatzl@7050:     }
tschatzl@7050:     return hr;
tschatzl@7050:   }
tschatzl@7050: 
tschatzl@7050:   inline void allocate_free_regions_starting_at(uint first, uint num_regions);
tschatzl@7050: 
tschatzl@7050:   // Remove all regions from the free list.
tschatzl@7050:   void remove_all_free_regions() {
tschatzl@7050:     _free_list.remove_all();
tschatzl@7050:   }
tschatzl@7050: 
tschatzl@7050:   // Return the number of committed free regions in the heap.
tschatzl@7050:   uint num_free_regions() const {
tschatzl@7050:     return _free_list.length();
tschatzl@7050:   }
tschatzl@7050: 
tschatzl@7050:   size_t total_capacity_bytes() const {
tschatzl@7050:     return num_free_regions() * HeapRegion::GrainBytes;
tschatzl@7050:   }
tschatzl@7050: 
tschatzl@7050:   // Return the number of available (uncommitted) regions.
tschatzl@7050:   uint available() const { return max_length() - length(); }
tschatzl@7050: 
tonyp@2963:   // Return the number of regions that have been committed in the heap.
tschatzl@7050:   uint length() const { return _num_committed; }
tonyp@2963: 
tonyp@2963:   // Return the maximum number of regions in the heap.
tschatzl@5773:   uint max_length() const { return (uint)_regions.length(); }
tonyp@2963: 
azakharov@7835:   MemoryUsage get_auxiliary_data_memory_usage() const;
azakharov@7835: 
tschatzl@7050:   MemRegion reserved() const { return MemRegion(heap_bottom(), heap_end()); }
ysr@777: 
tschatzl@7050:   // Expand the sequence to reflect that the heap has grown. Either create new
tschatzl@7050:   // HeapRegions, or re-use existing ones. Returns the number of regions the
tschatzl@7050:   // sequence was expanded by. If a HeapRegion allocation fails, the resulting
tschatzl@7050:   // number of regions might be smaller than what's desired.
tschatzl@7050:   uint expand_by(uint num_regions);
tschatzl@7050: 
tschatzl@7050:   // Makes sure that the regions from start to start+num_regions-1 are available
tschatzl@7050:   // for allocation. Returns the number of regions that were committed to achieve
tschatzl@7050:   // this.
tschatzl@7050:   uint expand_at(uint start, uint num_regions);
tschatzl@7050: 
tschatzl@7051:   // Find a contiguous set of empty regions of length num. Returns the start index of
tschatzl@7091:   // that set, or G1_NO_HRM_INDEX.
tschatzl@7051:   uint find_contiguous_only_empty(size_t num) { return find_contiguous(num, true); }
tschatzl@7051:   // Find a contiguous set of empty or unavailable regions of length num. Returns the
tschatzl@7091:   // start index of that set, or G1_NO_HRM_INDEX.
tschatzl@7051:   uint find_contiguous_empty_or_unavailable(size_t num) { return find_contiguous(num, false); }
tschatzl@7050: 
tschatzl@7050:   HeapRegion* next_region_in_heap(const HeapRegion* r) const;
ysr@777: 
tonyp@2963:   // Apply blk->doHeapRegion() on all committed regions in address order,
tonyp@2963:   // terminating the iteration early if doHeapRegion() returns true.
tonyp@2963:   void iterate(HeapRegionClosure* blk) const;
ysr@777: 
tschatzl@7050:   void par_iterate(HeapRegionClosure* blk, uint worker_id, uint no_of_par_workers, jint claim_value) const;
ysr@777: 
tschatzl@7050:   // Uncommit up to num_regions_to_remove regions that are completely free.
tschatzl@7050:   // Return the actual number of uncommitted regions.
brutisso@5074:   uint shrink_by(uint num_regions_to_remove);
ysr@777: 
tschatzl@7050:   void verify();
tschatzl@7050: 
tonyp@2963:   // Do some sanity checking.
tonyp@2963:   void verify_optional() PRODUCT_RETURN;
ysr@777: };
stefank@2314: 
tschatzl@7091: #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONMANAGER_HPP