--- old/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp	2015-05-12 11:55:04.849369503 +0200
+++ /dev/null	2015-03-18 17:10:38.111854831 +0100
@@ -1,1247 +0,0 @@
-/*
- * Copyright (c) 2001, 2015, 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.
- *
- */
-
-#include "precompiled.hpp"
-#include "gc_implementation/g1/concurrentG1Refine.hpp"
-#include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp"
-#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
-#include "gc_implementation/g1/heapRegionRemSet.hpp"
-#include "gc_implementation/g1/heapRegionManager.inline.hpp"
-#include "memory/allocation.hpp"
-#include "memory/padded.inline.hpp"
-#include "memory/space.inline.hpp"
-#include "oops/oop.inline.hpp"
-#include "runtime/atomic.inline.hpp"
-#include "utilities/bitMap.inline.hpp"
-#include "utilities/globalDefinitions.hpp"
-#include "utilities/growableArray.hpp"
-
-class PerRegionTable: public CHeapObj<mtGC> {
-  friend class OtherRegionsTable;
-  friend class HeapRegionRemSetIterator;
-
-  HeapRegion*     _hr;
-  BitMap          _bm;
-  jint            _occupied;
-
-  // next pointer for free/allocated 'all' list
-  PerRegionTable* _next;
-
-  // prev pointer for the allocated 'all' list
-  PerRegionTable* _prev;
-
-  // next pointer in collision list
-  PerRegionTable * _collision_list_next;
-
-  // Global free list of PRTs
-  static PerRegionTable* _free_list;
-
-protected:
-  // We need access in order to union things into the base table.
-  BitMap* bm() { return &_bm; }
-
-  void recount_occupied() {
-    _occupied = (jint) bm()->count_one_bits();
-  }
-
-  PerRegionTable(HeapRegion* hr) :
-    _hr(hr),
-    _occupied(0),
-    _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */),
-    _collision_list_next(NULL), _next(NULL), _prev(NULL)
-  {}
-
-  void add_card_work(CardIdx_t from_card, bool par) {
-    if (!_bm.at(from_card)) {
-      if (par) {
-        if (_bm.par_at_put(from_card, 1)) {
-          Atomic::inc(&_occupied);
-        }
-      } else {
-        _bm.at_put(from_card, 1);
-        _occupied++;
-      }
-    }
-  }
-
-  void add_reference_work(OopOrNarrowOopStar from, bool par) {
-    // Must make this robust in case "from" is not in "_hr", because of
-    // concurrency.
-
-    if (G1TraceHeapRegionRememberedSet) {
-      gclog_or_tty->print_cr("    PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").",
-                             p2i(from),
-                             UseCompressedOops
-                             ? p2i(oopDesc::load_decode_heap_oop((narrowOop*)from))
-                             : p2i(oopDesc::load_decode_heap_oop((oop*)from)));
-    }
-
-    HeapRegion* loc_hr = hr();
-    // If the test below fails, then this table was reused concurrently
-    // with this operation.  This is OK, since the old table was coarsened,
-    // and adding a bit to the new table is never incorrect.
-    // If the table used to belong to a continues humongous region and is
-    // now reused for the corresponding start humongous region, we need to
-    // make sure that we detect this. Thus, we call is_in_reserved_raw()
-    // instead of just is_in_reserved() here.
-    if (loc_hr->is_in_reserved_raw(from)) {
-      size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom());
-      CardIdx_t from_card = (CardIdx_t)
-          hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize);
-
-      assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion,
-             "Must be in range.");
-      add_card_work(from_card, par);
-    }
-  }
-
-public:
-
-  HeapRegion* hr() const { return _hr; }
-
-  jint occupied() const {
-    // Overkill, but if we ever need it...
-    // guarantee(_occupied == _bm.count_one_bits(), "Check");
-    return _occupied;
-  }
-
-  void init(HeapRegion* hr, bool clear_links_to_all_list) {
-    if (clear_links_to_all_list) {
-      set_next(NULL);
-      set_prev(NULL);
-    }
-    _hr = hr;
-    _collision_list_next = NULL;
-    _occupied = 0;
-    _bm.clear();
-  }
-
-  void add_reference(OopOrNarrowOopStar from) {
-    add_reference_work(from, /*parallel*/ true);
-  }
-
-  void seq_add_reference(OopOrNarrowOopStar from) {
-    add_reference_work(from, /*parallel*/ false);
-  }
-
-  void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) {
-    HeapWord* hr_bot = hr()->bottom();
-    size_t hr_first_card_index = ctbs->index_for(hr_bot);
-    bm()->set_intersection_at_offset(*card_bm, hr_first_card_index);
-    recount_occupied();
-  }
-
-  void add_card(CardIdx_t from_card_index) {
-    add_card_work(from_card_index, /*parallel*/ true);
-  }
-
-  void seq_add_card(CardIdx_t from_card_index) {
-    add_card_work(from_card_index, /*parallel*/ false);
-  }
-
-  // (Destructively) union the bitmap of the current table into the given
-  // bitmap (which is assumed to be of the same size.)
-  void union_bitmap_into(BitMap* bm) {
-    bm->set_union(_bm);
-  }
-
-  // Mem size in bytes.
-  size_t mem_size() const {
-    return sizeof(PerRegionTable) + _bm.size_in_words() * HeapWordSize;
-  }
-
-  // Requires "from" to be in "hr()".
-  bool contains_reference(OopOrNarrowOopStar from) const {
-    assert(hr()->is_in_reserved(from), "Precondition.");
-    size_t card_ind = pointer_delta(from, hr()->bottom(),
-                                    CardTableModRefBS::card_size);
-    return _bm.at(card_ind);
-  }
-
-  // Bulk-free the PRTs from prt to last, assumes that they are
-  // linked together using their _next field.
-  static void bulk_free(PerRegionTable* prt, PerRegionTable* last) {
-    while (true) {
-      PerRegionTable* fl = _free_list;
-      last->set_next(fl);
-      PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl);
-      if (res == fl) {
-        return;
-      }
-    }
-    ShouldNotReachHere();
-  }
-
-  static void free(PerRegionTable* prt) {
-    bulk_free(prt, prt);
-  }
-
-  // Returns an initialized PerRegionTable instance.
-  static PerRegionTable* alloc(HeapRegion* hr) {
-    PerRegionTable* fl = _free_list;
-    while (fl != NULL) {
-      PerRegionTable* nxt = fl->next();
-      PerRegionTable* res =
-        (PerRegionTable*)
-        Atomic::cmpxchg_ptr(nxt, &_free_list, fl);
-      if (res == fl) {
-        fl->init(hr, true);
-        return fl;
-      } else {
-        fl = _free_list;
-      }
-    }
-    assert(fl == NULL, "Loop condition.");
-    return new PerRegionTable(hr);
-  }
-
-  PerRegionTable* next() const { return _next; }
-  void set_next(PerRegionTable* next) { _next = next; }
-  PerRegionTable* prev() const { return _prev; }
-  void set_prev(PerRegionTable* prev) { _prev = prev; }
-
-  // Accessor and Modification routines for the pointer for the
-  // singly linked collision list that links the PRTs within the
-  // OtherRegionsTable::_fine_grain_regions hash table.
-  //
-  // It might be useful to also make the collision list doubly linked
-  // to avoid iteration over the collisions list during scrubbing/deletion.
-  // OTOH there might not be many collisions.
-
-  PerRegionTable* collision_list_next() const {
-    return _collision_list_next;
-  }
-
-  void set_collision_list_next(PerRegionTable* next) {
-    _collision_list_next = next;
-  }
-
-  PerRegionTable** collision_list_next_addr() {
-    return &_collision_list_next;
-  }
-
-  static size_t fl_mem_size() {
-    PerRegionTable* cur = _free_list;
-    size_t res = 0;
-    while (cur != NULL) {
-      res += cur->mem_size();
-      cur = cur->next();
-    }
-    return res;
-  }
-
-  static void test_fl_mem_size();
-};
-
-PerRegionTable* PerRegionTable::_free_list = NULL;
-
-size_t OtherRegionsTable::_max_fine_entries = 0;
-size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
-size_t OtherRegionsTable::_fine_eviction_stride = 0;
-size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
-
-OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) :
-  _g1h(G1CollectedHeap::heap()),
-  _hr(hr), _m(m),
-  _coarse_map(G1CollectedHeap::heap()->max_regions(),
-              false /* in-resource-area */),
-  _fine_grain_regions(NULL),
-  _first_all_fine_prts(NULL), _last_all_fine_prts(NULL),
-  _n_fine_entries(0), _n_coarse_entries(0),
-  _fine_eviction_start(0),
-  _sparse_table(hr)
-{
-  typedef PerRegionTable* PerRegionTablePtr;
-
-  if (_max_fine_entries == 0) {
-    assert(_mod_max_fine_entries_mask == 0, "Both or none.");
-    size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
-    _max_fine_entries = (size_t)1 << max_entries_log;
-    _mod_max_fine_entries_mask = _max_fine_entries - 1;
-
-    assert(_fine_eviction_sample_size == 0
-           && _fine_eviction_stride == 0, "All init at same time.");
-    _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
-    _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
-  }
-
-  _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries,
-                        mtGC, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
-
-  if (_fine_grain_regions == NULL) {
-    vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR,
-                          "Failed to allocate _fine_grain_entries.");
-  }
-
-  for (size_t i = 0; i < _max_fine_entries; i++) {
-    _fine_grain_regions[i] = NULL;
-  }
-}
-
-void OtherRegionsTable::link_to_all(PerRegionTable* prt) {
-  // We always append to the beginning of the list for convenience;
-  // the order of entries in this list does not matter.
-  if (_first_all_fine_prts != NULL) {
-    assert(_first_all_fine_prts->prev() == NULL, "invariant");
-    _first_all_fine_prts->set_prev(prt);
-    prt->set_next(_first_all_fine_prts);
-  } else {
-    // this is the first element we insert. Adjust the "last" pointer
-    _last_all_fine_prts = prt;
-    assert(prt->next() == NULL, "just checking");
-  }
-  // the new element is always the first element without a predecessor
-  prt->set_prev(NULL);
-  _first_all_fine_prts = prt;
-
-  assert(prt->prev() == NULL, "just checking");
-  assert(_first_all_fine_prts == prt, "just checking");
-  assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
-         (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
-         "just checking");
-  assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
-         "just checking");
-  assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
-         "just checking");
-}
-
-void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) {
-  if (prt->prev() != NULL) {
-    assert(_first_all_fine_prts != prt, "just checking");
-    prt->prev()->set_next(prt->next());
-    // removing the last element in the list?
-    if (_last_all_fine_prts == prt) {
-      _last_all_fine_prts = prt->prev();
-    }
-  } else {
-    assert(_first_all_fine_prts == prt, "just checking");
-    _first_all_fine_prts = prt->next();
-    // list is empty now?
-    if (_first_all_fine_prts == NULL) {
-      _last_all_fine_prts = NULL;
-    }
-  }
-
-  if (prt->next() != NULL) {
-    prt->next()->set_prev(prt->prev());
-  }
-
-  prt->set_next(NULL);
-  prt->set_prev(NULL);
-
-  assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
-         (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
-         "just checking");
-  assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
-         "just checking");
-  assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
-         "just checking");
-}
-
-int**  FromCardCache::_cache = NULL;
-uint   FromCardCache::_max_regions = 0;
-size_t FromCardCache::_static_mem_size = 0;
-
-void FromCardCache::initialize(uint n_par_rs, uint max_num_regions) {
-  guarantee(_cache == NULL, "Should not call this multiple times");
-
-  _max_regions = max_num_regions;
-  _cache = Padded2DArray<int, mtGC>::create_unfreeable(n_par_rs,
-                                                       _max_regions,
-                                                       &_static_mem_size);
-
-  invalidate(0, _max_regions);
-}
-
-void FromCardCache::invalidate(uint start_idx, size_t new_num_regions) {
-  guarantee((size_t)start_idx + new_num_regions <= max_uintx,
-            err_msg("Trying to invalidate beyond maximum region, from %u size "SIZE_FORMAT,
-                    start_idx, new_num_regions));
-  for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
-    uint end_idx = (start_idx + (uint)new_num_regions);
-    assert(end_idx <= _max_regions, "Must be within max.");
-    for (uint j = start_idx; j < end_idx; j++) {
-      set(i, j, InvalidCard);
-    }
-  }
-}
-
-#ifndef PRODUCT
-void FromCardCache::print(outputStream* out) {
-  for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
-    for (uint j = 0; j < _max_regions; j++) {
-      out->print_cr("_from_card_cache[%u][%u] = %d.",
-                    i, j, at(i, j));
-    }
-  }
-}
-#endif
-
-void FromCardCache::clear(uint region_idx) {
-  uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets();
-  for (uint i = 0; i < num_par_remsets; i++) {
-    set(i, region_idx, InvalidCard);
-  }
-}
-
-void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, uint tid) {
-  uint cur_hrm_ind = _hr->hrm_index();
-
-  if (G1TraceHeapRegionRememberedSet) {
-    gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").",
-                                                    p2i(from),
-                                                    UseCompressedOops
-                                                    ? p2i(oopDesc::load_decode_heap_oop((narrowOop*)from))
-                                                    : p2i(oopDesc::load_decode_heap_oop((oop*)from)));
-  }
-
-  int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift);
-
-  if (G1TraceHeapRegionRememberedSet) {
-    gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)",
-                  p2i(_hr->bottom()), from_card,
-                  FromCardCache::at(tid, cur_hrm_ind));
-  }
-
-  if (FromCardCache::contains_or_replace(tid, cur_hrm_ind, from_card)) {
-    if (G1TraceHeapRegionRememberedSet) {
-      gclog_or_tty->print_cr("  from-card cache hit.");
-    }
-    assert(contains_reference(from), "We just added it!");
-    return;
-  }
-
-  // Note that this may be a continued H region.
-  HeapRegion* from_hr = _g1h->heap_region_containing_raw(from);
-  RegionIdx_t from_hrm_ind = (RegionIdx_t) from_hr->hrm_index();
-
-  // If the region is already coarsened, return.
-  if (_coarse_map.at(from_hrm_ind)) {
-    if (G1TraceHeapRegionRememberedSet) {
-      gclog_or_tty->print_cr("  coarse map hit.");
-    }
-    assert(contains_reference(from), "We just added it!");
-    return;
-  }
-
-  // Otherwise find a per-region table to add it to.
-  size_t ind = from_hrm_ind & _mod_max_fine_entries_mask;
-  PerRegionTable* prt = find_region_table(ind, from_hr);
-  if (prt == NULL) {
-    MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
-    // Confirm that it's really not there...
-    prt = find_region_table(ind, from_hr);
-    if (prt == NULL) {
-
-      uintptr_t from_hr_bot_card_index =
-        uintptr_t(from_hr->bottom())
-          >> CardTableModRefBS::card_shift;
-      CardIdx_t card_index = from_card - from_hr_bot_card_index;
-      assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
-             "Must be in range.");
-      if (G1HRRSUseSparseTable &&
-          _sparse_table.add_card(from_hrm_ind, card_index)) {
-        if (G1RecordHRRSOops) {
-          HeapRegionRemSet::record(_hr, from);
-          if (G1TraceHeapRegionRememberedSet) {
-            gclog_or_tty->print("   Added card " PTR_FORMAT " to region "
-                                "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
-                                align_size_down(uintptr_t(from),
-                                                CardTableModRefBS::card_size),
-                                p2i(_hr->bottom()), p2i(from));
-          }
-        }
-        if (G1TraceHeapRegionRememberedSet) {
-          gclog_or_tty->print_cr("   added card to sparse table.");
-        }
-        assert(contains_reference_locked(from), "We just added it!");
-        return;
-      } else {
-        if (G1TraceHeapRegionRememberedSet) {
-          gclog_or_tty->print_cr("   [tid %u] sparse table entry "
-                        "overflow(f: %d, t: %u)",
-                        tid, from_hrm_ind, cur_hrm_ind);
-        }
-      }
-
-      if (_n_fine_entries == _max_fine_entries) {
-        prt = delete_region_table();
-        // There is no need to clear the links to the 'all' list here:
-        // prt will be reused immediately, i.e. remain in the 'all' list.
-        prt->init(from_hr, false /* clear_links_to_all_list */);
-      } else {
-        prt = PerRegionTable::alloc(from_hr);
-        link_to_all(prt);
-      }
-
-      PerRegionTable* first_prt = _fine_grain_regions[ind];
-      prt->set_collision_list_next(first_prt);
-      _fine_grain_regions[ind] = prt;
-      _n_fine_entries++;
-
-      if (G1HRRSUseSparseTable) {
-        // Transfer from sparse to fine-grain.
-        SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrm_ind);
-        assert(sprt_entry != NULL, "There should have been an entry");
-        for (int i = 0; i < SparsePRTEntry::cards_num(); i++) {
-          CardIdx_t c = sprt_entry->card(i);
-          if (c != SparsePRTEntry::NullEntry) {
-            prt->add_card(c);
-          }
-        }
-        // Now we can delete the sparse entry.
-        bool res = _sparse_table.delete_entry(from_hrm_ind);
-        assert(res, "It should have been there.");
-      }
-    }
-    assert(prt != NULL && prt->hr() == from_hr, "consequence");
-  }
-  // Note that we can't assert "prt->hr() == from_hr", because of the
-  // possibility of concurrent reuse.  But see head comment of
-  // OtherRegionsTable for why this is OK.
-  assert(prt != NULL, "Inv");
-
-  prt->add_reference(from);
-
-  if (G1RecordHRRSOops) {
-    HeapRegionRemSet::record(_hr, from);
-    if (G1TraceHeapRegionRememberedSet) {
-      gclog_or_tty->print("Added card " PTR_FORMAT " to region "
-                          "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
-                          align_size_down(uintptr_t(from),
-                                          CardTableModRefBS::card_size),
-                          p2i(_hr->bottom()), p2i(from));
-    }
-  }
-  assert(contains_reference(from), "We just added it!");
-}
-
-PerRegionTable*
-OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const {
-  assert(ind < _max_fine_entries, "Preconditions.");
-  PerRegionTable* prt = _fine_grain_regions[ind];
-  while (prt != NULL && prt->hr() != hr) {
-    prt = prt->collision_list_next();
-  }
-  // Loop postcondition is the method postcondition.
-  return prt;
-}
-
-jint OtherRegionsTable::_n_coarsenings = 0;
-
-PerRegionTable* OtherRegionsTable::delete_region_table() {
-  assert(_m->owned_by_self(), "Precondition");
-  assert(_n_fine_entries == _max_fine_entries, "Precondition");
-  PerRegionTable* max = NULL;
-  jint max_occ = 0;
-  PerRegionTable** max_prev;
-  size_t max_ind;
-
-  size_t i = _fine_eviction_start;
-  for (size_t k = 0; k < _fine_eviction_sample_size; k++) {
-    size_t ii = i;
-    // Make sure we get a non-NULL sample.
-    while (_fine_grain_regions[ii] == NULL) {
-      ii++;
-      if (ii == _max_fine_entries) ii = 0;
-      guarantee(ii != i, "We must find one.");
-    }
-    PerRegionTable** prev = &_fine_grain_regions[ii];
-    PerRegionTable* cur = *prev;
-    while (cur != NULL) {
-      jint cur_occ = cur->occupied();
-      if (max == NULL || cur_occ > max_occ) {
-        max = cur;
-        max_prev = prev;
-        max_ind = i;
-        max_occ = cur_occ;
-      }
-      prev = cur->collision_list_next_addr();
-      cur = cur->collision_list_next();
-    }
-    i = i + _fine_eviction_stride;
-    if (i >= _n_fine_entries) i = i - _n_fine_entries;
-  }
-
-  _fine_eviction_start++;
-
-  if (_fine_eviction_start >= _n_fine_entries) {
-    _fine_eviction_start -= _n_fine_entries;
-  }
-
-  guarantee(max != NULL, "Since _n_fine_entries > 0");
-
-  // Set the corresponding coarse bit.
-  size_t max_hrm_index = (size_t) max->hr()->hrm_index();
-  if (!_coarse_map.at(max_hrm_index)) {
-    _coarse_map.at_put(max_hrm_index, true);
-    _n_coarse_entries++;
-    if (G1TraceHeapRegionRememberedSet) {
-      gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] "
-                 "for region [" PTR_FORMAT "...] (" SIZE_FORMAT " coarse entries).\n",
-                 p2i(_hr->bottom()),
-                 p2i(max->hr()->bottom()),
-                 _n_coarse_entries);
-    }
-  }
-
-  // Unsplice.
-  *max_prev = max->collision_list_next();
-  Atomic::inc(&_n_coarsenings);
-  _n_fine_entries--;
-  return max;
-}
-
-void OtherRegionsTable::scrub(CardTableModRefBS* ctbs,
-                              BitMap* region_bm, BitMap* card_bm) {
-  // First eliminated garbage regions from the coarse map.
-  if (G1RSScrubVerbose) {
-    gclog_or_tty->print_cr("Scrubbing region %u:", _hr->hrm_index());
-  }
-
-  assert(_coarse_map.size() == region_bm->size(), "Precondition");
-  if (G1RSScrubVerbose) {
-    gclog_or_tty->print("   Coarse map: before = "SIZE_FORMAT"...",
-                        _n_coarse_entries);
-  }
-  _coarse_map.set_intersection(*region_bm);
-  _n_coarse_entries = _coarse_map.count_one_bits();
-  if (G1RSScrubVerbose) {
-    gclog_or_tty->print_cr("   after = "SIZE_FORMAT".", _n_coarse_entries);
-  }
-
-  // Now do the fine-grained maps.
-  for (size_t i = 0; i < _max_fine_entries; i++) {
-    PerRegionTable* cur = _fine_grain_regions[i];
-    PerRegionTable** prev = &_fine_grain_regions[i];
-    while (cur != NULL) {
-      PerRegionTable* nxt = cur->collision_list_next();
-      // If the entire region is dead, eliminate.
-      if (G1RSScrubVerbose) {
-        gclog_or_tty->print_cr("     For other region %u:",
-                               cur->hr()->hrm_index());
-      }
-      if (!region_bm->at((size_t) cur->hr()->hrm_index())) {
-        *prev = nxt;
-        cur->set_collision_list_next(NULL);
-        _n_fine_entries--;
-        if (G1RSScrubVerbose) {
-          gclog_or_tty->print_cr("          deleted via region map.");
-        }
-        unlink_from_all(cur);
-        PerRegionTable::free(cur);
-      } else {
-        // Do fine-grain elimination.
-        if (G1RSScrubVerbose) {
-          gclog_or_tty->print("          occ: before = %4d.", cur->occupied());
-        }
-        cur->scrub(ctbs, card_bm);
-        if (G1RSScrubVerbose) {
-          gclog_or_tty->print_cr("          after = %4d.", cur->occupied());
-        }
-        // Did that empty the table completely?
-        if (cur->occupied() == 0) {
-          *prev = nxt;
-          cur->set_collision_list_next(NULL);
-          _n_fine_entries--;
-          unlink_from_all(cur);
-          PerRegionTable::free(cur);
-        } else {
-          prev = cur->collision_list_next_addr();
-        }
-      }
-      cur = nxt;
-    }
-  }
-  // Since we may have deleted a from_card_cache entry from the RS, clear
-  // the FCC.
-  clear_fcc();
-}
-
-bool OtherRegionsTable::occupancy_less_or_equal_than(size_t limit) const {
-  if (limit <= (size_t)G1RSetSparseRegionEntries) {
-    return occ_coarse() == 0 && _first_all_fine_prts == NULL && occ_sparse() <= limit;
-  } else {
-    // Current uses of this method may only use values less than G1RSetSparseRegionEntries
-    // for the limit. The solution, comparing against occupied() would be too slow
-    // at this time.
-    Unimplemented();
-    return false;
-  }
-}
-
-bool OtherRegionsTable::is_empty() const {
-  return occ_sparse() == 0 && occ_coarse() == 0 && _first_all_fine_prts == NULL;
-}
-
-size_t OtherRegionsTable::occupied() const {
-  size_t sum = occ_fine();
-  sum += occ_sparse();
-  sum += occ_coarse();
-  return sum;
-}
-
-size_t OtherRegionsTable::occ_fine() const {
-  size_t sum = 0;
-
-  size_t num = 0;
-  PerRegionTable * cur = _first_all_fine_prts;
-  while (cur != NULL) {
-    sum += cur->occupied();
-    cur = cur->next();
-    num++;
-  }
-  guarantee(num == _n_fine_entries, "just checking");
-  return sum;
-}
-
-size_t OtherRegionsTable::occ_coarse() const {
-  return (_n_coarse_entries * HeapRegion::CardsPerRegion);
-}
-
-size_t OtherRegionsTable::occ_sparse() const {
-  return _sparse_table.occupied();
-}
-
-size_t OtherRegionsTable::mem_size() const {
-  size_t sum = 0;
-  // all PRTs are of the same size so it is sufficient to query only one of them.
-  if (_first_all_fine_prts != NULL) {
-    assert(_last_all_fine_prts != NULL &&
-      _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant");
-    sum += _first_all_fine_prts->mem_size() * _n_fine_entries;
-  }
-  sum += (sizeof(PerRegionTable*) * _max_fine_entries);
-  sum += (_coarse_map.size_in_words() * HeapWordSize);
-  sum += (_sparse_table.mem_size());
-  sum += sizeof(OtherRegionsTable) - sizeof(_sparse_table); // Avoid double counting above.
-  return sum;
-}
-
-size_t OtherRegionsTable::static_mem_size() {
-  return FromCardCache::static_mem_size();
-}
-
-size_t OtherRegionsTable::fl_mem_size() {
-  return PerRegionTable::fl_mem_size();
-}
-
-void OtherRegionsTable::clear_fcc() {
-  FromCardCache::clear(_hr->hrm_index());
-}
-
-void OtherRegionsTable::clear() {
-  // if there are no entries, skip this step
-  if (_first_all_fine_prts != NULL) {
-    guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
-    PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts);
-    memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0]));
-  } else {
-    guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking");
-  }
-
-  _first_all_fine_prts = _last_all_fine_prts = NULL;
-  _sparse_table.clear();
-  _coarse_map.clear();
-  _n_fine_entries = 0;
-  _n_coarse_entries = 0;
-
-  clear_fcc();
-}
-
-bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
-  // Cast away const in this case.
-  MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag);
-  return contains_reference_locked(from);
-}
-
-bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
-  HeapRegion* hr = _g1h->heap_region_containing_raw(from);
-  RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index();
-  // Is this region in the coarse map?
-  if (_coarse_map.at(hr_ind)) return true;
-
-  PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
-                                     hr);
-  if (prt != NULL) {
-    return prt->contains_reference(from);
-
-  } else {
-    uintptr_t from_card =
-      (uintptr_t(from) >> CardTableModRefBS::card_shift);
-    uintptr_t hr_bot_card_index =
-      uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift;
-    assert(from_card >= hr_bot_card_index, "Inv");
-    CardIdx_t card_index = from_card - hr_bot_card_index;
-    assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
-           "Must be in range.");
-    return _sparse_table.contains_card(hr_ind, card_index);
-  }
-}
-
-void
-OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
-  _sparse_table.do_cleanup_work(hrrs_cleanup_task);
-}
-
-// Determines how many threads can add records to an rset in parallel.
-// This can be done by either mutator threads together with the
-// concurrent refinement threads or GC threads.
-uint HeapRegionRemSet::num_par_rem_sets() {
-  return MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), (uint)ParallelGCThreads);
-}
-
-HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
-                                   HeapRegion* hr)
-  : _bosa(bosa),
-    _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true, Monitor::_safepoint_check_never),
-    _code_roots(), _other_regions(hr, &_m), _iter_state(Unclaimed), _iter_claimed(0) {
-  reset_for_par_iteration();
-}
-
-void HeapRegionRemSet::setup_remset_size() {
-  // Setup sparse and fine-grain tables sizes.
-  // table_size = base * (log(region_size / 1M) + 1)
-  const int LOG_M = 20;
-  int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0);
-  if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) {
-    G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1);
-  }
-  if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) {
-    G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1);
-  }
-  guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity");
-}
-
-bool HeapRegionRemSet::claim_iter() {
-  if (_iter_state != Unclaimed) return false;
-  jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed);
-  return (res == Unclaimed);
-}
-
-void HeapRegionRemSet::set_iter_complete() {
-  _iter_state = Complete;
-}
-
-bool HeapRegionRemSet::iter_is_complete() {
-  return _iter_state == Complete;
-}
-
-#ifndef PRODUCT
-void HeapRegionRemSet::print() {
-  HeapRegionRemSetIterator iter(this);
-  size_t card_index;
-  while (iter.has_next(card_index)) {
-    HeapWord* card_start =
-      G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
-    gclog_or_tty->print_cr("  Card " PTR_FORMAT, p2i(card_start));
-  }
-  if (iter.n_yielded() != occupied()) {
-    gclog_or_tty->print_cr("Yielded disagrees with occupied:");
-    gclog_or_tty->print_cr("  " SIZE_FORMAT_W(6) " yielded (" SIZE_FORMAT_W(6)
-                  " coarse, " SIZE_FORMAT_W(6) " fine).",
-                  iter.n_yielded(),
-                  iter.n_yielded_coarse(), iter.n_yielded_fine());
-    gclog_or_tty->print_cr("  " SIZE_FORMAT_W(6) " occ     (" SIZE_FORMAT_W(6)
-                           " coarse, " SIZE_FORMAT_W(6) " fine).",
-                  occupied(), occ_coarse(), occ_fine());
-  }
-  guarantee(iter.n_yielded() == occupied(),
-            "We should have yielded all the represented cards.");
-}
-#endif
-
-void HeapRegionRemSet::cleanup() {
-  SparsePRT::cleanup_all();
-}
-
-void HeapRegionRemSet::clear() {
-  MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
-  clear_locked();
-}
-
-void HeapRegionRemSet::clear_locked() {
-  _code_roots.clear();
-  _other_regions.clear();
-  assert(occupied_locked() == 0, "Should be clear.");
-  reset_for_par_iteration();
-}
-
-void HeapRegionRemSet::reset_for_par_iteration() {
-  _iter_state = Unclaimed;
-  _iter_claimed = 0;
-  // It's good to check this to make sure that the two methods are in sync.
-  assert(verify_ready_for_par_iteration(), "post-condition");
-}
-
-void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
-                             BitMap* region_bm, BitMap* card_bm) {
-  _other_regions.scrub(ctbs, region_bm, card_bm);
-}
-
-// Code roots support
-//
-// The code root set is protected by two separate locking schemes
-// When at safepoint the per-hrrs lock must be held during modifications
-// except when doing a full gc.
-// When not at safepoint the CodeCache_lock must be held during modifications.
-// When concurrent readers access the contains() function
-// (during the evacuation phase) no removals are allowed.
-
-void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
-  assert(nm != NULL, "sanity");
-  // Optimistic unlocked contains-check
-  if (!_code_roots.contains(nm)) {
-    MutexLockerEx ml(&_m, Mutex::_no_safepoint_check_flag);
-    add_strong_code_root_locked(nm);
-  }
-}
-
-void HeapRegionRemSet::add_strong_code_root_locked(nmethod* nm) {
-  assert(nm != NULL, "sanity");
-  _code_roots.add(nm);
-}
-
-void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
-  assert(nm != NULL, "sanity");
-  assert_locked_or_safepoint(CodeCache_lock);
-
-  MutexLockerEx ml(CodeCache_lock->owned_by_self() ? NULL : &_m, Mutex::_no_safepoint_check_flag);
-  _code_roots.remove(nm);
-
-  // Check that there were no duplicates
-  guarantee(!_code_roots.contains(nm), "duplicate entry found");
-}
-
-void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
-  _code_roots.nmethods_do(blk);
-}
-
-void HeapRegionRemSet::clean_strong_code_roots(HeapRegion* hr) {
-  _code_roots.clean(hr);
-}
-
-size_t HeapRegionRemSet::strong_code_roots_mem_size() {
-  return _code_roots.mem_size();
-}
-
-HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) :
-  _hrrs(hrrs),
-  _g1h(G1CollectedHeap::heap()),
-  _coarse_map(&hrrs->_other_regions._coarse_map),
-  _bosa(hrrs->_bosa),
-  _is(Sparse),
-  // Set these values so that we increment to the first region.
-  _coarse_cur_region_index(-1),
-  _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1),
-  _cur_card_in_prt(HeapRegion::CardsPerRegion),
-  _fine_cur_prt(NULL),
-  _n_yielded_coarse(0),
-  _n_yielded_fine(0),
-  _n_yielded_sparse(0),
-  _sparse_iter(&hrrs->_other_regions._sparse_table) {}
-
-bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) {
-  if (_hrrs->_other_regions._n_coarse_entries == 0) return false;
-  // Go to the next card.
-  _coarse_cur_region_cur_card++;
-  // Was the last the last card in the current region?
-  if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) {
-    // Yes: find the next region.  This may leave _coarse_cur_region_index
-    // Set to the last index, in which case there are no more coarse
-    // regions.
-    _coarse_cur_region_index =
-      (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1);
-    if ((size_t)_coarse_cur_region_index < _coarse_map->size()) {
-      _coarse_cur_region_cur_card = 0;
-      HeapWord* r_bot =
-        _g1h->region_at((uint) _coarse_cur_region_index)->bottom();
-      _cur_region_card_offset = _bosa->index_for(r_bot);
-    } else {
-      return false;
-    }
-  }
-  // If we didn't return false above, then we can yield a card.
-  card_index = _cur_region_card_offset + _coarse_cur_region_cur_card;
-  return true;
-}
-
-bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) {
-  if (fine_has_next()) {
-    _cur_card_in_prt =
-      _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
-  }
-  if (_cur_card_in_prt == HeapRegion::CardsPerRegion) {
-    // _fine_cur_prt may still be NULL in case if there are not PRTs at all for
-    // the remembered set.
-    if (_fine_cur_prt == NULL || _fine_cur_prt->next() == NULL) {
-      return false;
-    }
-    PerRegionTable* next_prt = _fine_cur_prt->next();
-    switch_to_prt(next_prt);
-    _cur_card_in_prt = _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
-  }
-
-  card_index = _cur_region_card_offset + _cur_card_in_prt;
-  guarantee(_cur_card_in_prt < HeapRegion::CardsPerRegion,
-            err_msg("Card index "SIZE_FORMAT" must be within the region", _cur_card_in_prt));
-  return true;
-}
-
-bool HeapRegionRemSetIterator::fine_has_next() {
-  return _cur_card_in_prt != HeapRegion::CardsPerRegion;
-}
-
-void HeapRegionRemSetIterator::switch_to_prt(PerRegionTable* prt) {
-  assert(prt != NULL, "Cannot switch to NULL prt");
-  _fine_cur_prt = prt;
-
-  HeapWord* r_bot = _fine_cur_prt->hr()->bottom();
-  _cur_region_card_offset = _bosa->index_for(r_bot);
-
-  // The bitmap scan for the PRT always scans from _cur_region_cur_card + 1.
-  // To avoid special-casing this start case, and not miss the first bitmap
-  // entry, initialize _cur_region_cur_card with -1 instead of 0.
-  _cur_card_in_prt = (size_t)-1;
-}
-
-bool HeapRegionRemSetIterator::has_next(size_t& card_index) {
-  switch (_is) {
-  case Sparse: {
-    if (_sparse_iter.has_next(card_index)) {
-      _n_yielded_sparse++;
-      return true;
-    }
-    // Otherwise, deliberate fall-through
-    _is = Fine;
-    PerRegionTable* initial_fine_prt = _hrrs->_other_regions._first_all_fine_prts;
-    if (initial_fine_prt != NULL) {
-      switch_to_prt(_hrrs->_other_regions._first_all_fine_prts);
-    }
-  }
-  case Fine:
-    if (fine_has_next(card_index)) {
-      _n_yielded_fine++;
-      return true;
-    }
-    // Otherwise, deliberate fall-through
-    _is = Coarse;
-  case Coarse:
-    if (coarse_has_next(card_index)) {
-      _n_yielded_coarse++;
-      return true;
-    }
-    // Otherwise...
-    break;
-  }
-  assert(ParallelGCThreads > 1 ||
-         n_yielded() == _hrrs->occupied(),
-         "Should have yielded all the cards in the rem set "
-         "(in the non-par case).");
-  return false;
-}
-
-
-
-OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL;
-HeapWord**          HeapRegionRemSet::_recorded_cards = NULL;
-HeapRegion**        HeapRegionRemSet::_recorded_regions = NULL;
-int                 HeapRegionRemSet::_n_recorded = 0;
-
-HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL;
-int*         HeapRegionRemSet::_recorded_event_index = NULL;
-int          HeapRegionRemSet::_n_recorded_events = 0;
-
-void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) {
-  if (_recorded_oops == NULL) {
-    assert(_n_recorded == 0
-           && _recorded_cards == NULL
-           && _recorded_regions == NULL,
-           "Inv");
-    _recorded_oops    = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded, mtGC);
-    _recorded_cards   = NEW_C_HEAP_ARRAY(HeapWord*,          MaxRecorded, mtGC);
-    _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*,        MaxRecorded, mtGC);
-  }
-  if (_n_recorded == MaxRecorded) {
-    gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded);
-  } else {
-    _recorded_cards[_n_recorded] =
-      (HeapWord*)align_size_down(uintptr_t(f),
-                                 CardTableModRefBS::card_size);
-    _recorded_oops[_n_recorded] = f;
-    _recorded_regions[_n_recorded] = hr;
-    _n_recorded++;
-  }
-}
-
-void HeapRegionRemSet::record_event(Event evnt) {
-  if (!G1RecordHRRSEvents) return;
-
-  if (_recorded_events == NULL) {
-    assert(_n_recorded_events == 0
-           && _recorded_event_index == NULL,
-           "Inv");
-    _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents, mtGC);
-    _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents, mtGC);
-  }
-  if (_n_recorded_events == MaxRecordedEvents) {
-    gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents);
-  } else {
-    _recorded_events[_n_recorded_events] = evnt;
-    _recorded_event_index[_n_recorded_events] = _n_recorded;
-    _n_recorded_events++;
-  }
-}
-
-void HeapRegionRemSet::print_event(outputStream* str, Event evnt) {
-  switch (evnt) {
-  case Event_EvacStart:
-    str->print("Evac Start");
-    break;
-  case Event_EvacEnd:
-    str->print("Evac End");
-    break;
-  case Event_RSUpdateEnd:
-    str->print("RS Update End");
-    break;
-  }
-}
-
-void HeapRegionRemSet::print_recorded() {
-  int cur_evnt = 0;
-  Event cur_evnt_kind;
-  int cur_evnt_ind = 0;
-  if (_n_recorded_events > 0) {
-    cur_evnt_kind = _recorded_events[cur_evnt];
-    cur_evnt_ind = _recorded_event_index[cur_evnt];
-  }
-
-  for (int i = 0; i < _n_recorded; i++) {
-    while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) {
-      gclog_or_tty->print("Event: ");
-      print_event(gclog_or_tty, cur_evnt_kind);
-      gclog_or_tty->cr();
-      cur_evnt++;
-      if (cur_evnt < MaxRecordedEvents) {
-        cur_evnt_kind = _recorded_events[cur_evnt];
-        cur_evnt_ind = _recorded_event_index[cur_evnt];
-      }
-    }
-    gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]"
-                        " for ref " PTR_FORMAT ".\n",
-                        p2i(_recorded_cards[i]), p2i(_recorded_regions[i]->bottom()),
-                        p2i(_recorded_oops[i]));
-  }
-}
-
-void HeapRegionRemSet::reset_for_cleanup_tasks() {
-  SparsePRT::reset_for_cleanup_tasks();
-}
-
-void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
-  _other_regions.do_cleanup_work(hrrs_cleanup_task);
-}
-
-void
-HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) {
-  SparsePRT::finish_cleanup_task(hrrs_cleanup_task);
-}
-
-#ifndef PRODUCT
-void PerRegionTable::test_fl_mem_size() {
-  PerRegionTable* dummy = alloc(NULL);
-
-  size_t min_prt_size = sizeof(void*) + dummy->bm()->size_in_words() * HeapWordSize;
-  assert(dummy->mem_size() > min_prt_size,
-         err_msg("PerRegionTable memory usage is suspiciously small, only has "SIZE_FORMAT" bytes. "
-                 "Should be at least "SIZE_FORMAT" bytes.", dummy->mem_size(), min_prt_size));
-  free(dummy);
-  guarantee(dummy->mem_size() == fl_mem_size(), "fl_mem_size() does not return the correct element size");
-  // try to reset the state
-  _free_list = NULL;
-  delete dummy;
-}
-
-void HeapRegionRemSet::test_prt() {
-  PerRegionTable::test_fl_mem_size();
-}
-
-void HeapRegionRemSet::test() {
-  os::sleep(Thread::current(), (jlong)5000, false);
-  G1CollectedHeap* g1h = G1CollectedHeap::heap();
-
-  // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same
-  // hash bucket.
-  HeapRegion* hr0 = g1h->region_at(0);
-  HeapRegion* hr1 = g1h->region_at(1);
-  HeapRegion* hr2 = g1h->region_at(5);
-  HeapRegion* hr3 = g1h->region_at(6);
-  HeapRegion* hr4 = g1h->region_at(7);
-  HeapRegion* hr5 = g1h->region_at(8);
-
-  HeapWord* hr1_start = hr1->bottom();
-  HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2;
-  HeapWord* hr1_last = hr1->end() - 1;
-
-  HeapWord* hr2_start = hr2->bottom();
-  HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2;
-  HeapWord* hr2_last = hr2->end() - 1;
-
-  HeapWord* hr3_start = hr3->bottom();
-  HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2;
-  HeapWord* hr3_last = hr3->end() - 1;
-
-  HeapRegionRemSet* hrrs = hr0->rem_set();
-
-  // Make three references from region 0x101...
-  hrrs->add_reference((OopOrNarrowOopStar)hr1_start);
-  hrrs->add_reference((OopOrNarrowOopStar)hr1_mid);
-  hrrs->add_reference((OopOrNarrowOopStar)hr1_last);
-
-  hrrs->add_reference((OopOrNarrowOopStar)hr2_start);
-  hrrs->add_reference((OopOrNarrowOopStar)hr2_mid);
-  hrrs->add_reference((OopOrNarrowOopStar)hr2_last);
-
-  hrrs->add_reference((OopOrNarrowOopStar)hr3_start);
-  hrrs->add_reference((OopOrNarrowOopStar)hr3_mid);
-  hrrs->add_reference((OopOrNarrowOopStar)hr3_last);
-
-  // Now cause a coarsening.
-  hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom());
-  hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom());
-
-  // Now, does iteration yield these three?
-  HeapRegionRemSetIterator iter(hrrs);
-  size_t sum = 0;
-  size_t card_index;
-  while (iter.has_next(card_index)) {
-    HeapWord* card_start =
-      G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
-    gclog_or_tty->print_cr("  Card " PTR_FORMAT ".", p2i(card_start));
-    sum++;
-  }
-  guarantee(sum == 11 - 3 + 2048, "Failure");
-  guarantee(sum == hrrs->occupied(), "Failure");
-}
-#endif
--- /dev/null	2015-03-18 17:10:38.111854831 +0100
+++ new/src/share/vm/gc/g1/heapRegionRemSet.cpp	2015-05-12 11:55:04.640360766 +0200
@@ -0,0 +1,1247 @@
+/*
+ * Copyright (c) 2001, 2015, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/g1/concurrentG1Refine.hpp"
+#include "gc/g1/g1BlockOffsetTable.inline.hpp"
+#include "gc/g1/g1CollectedHeap.inline.hpp"
+#include "gc/g1/heapRegionManager.inline.hpp"
+#include "gc/g1/heapRegionRemSet.hpp"
+#include "gc/shared/space.inline.hpp"
+#include "memory/allocation.hpp"
+#include "memory/padded.inline.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/atomic.inline.hpp"
+#include "utilities/bitMap.inline.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/growableArray.hpp"
+
+class PerRegionTable: public CHeapObj<mtGC> {
+  friend class OtherRegionsTable;
+  friend class HeapRegionRemSetIterator;
+
+  HeapRegion*     _hr;
+  BitMap          _bm;
+  jint            _occupied;
+
+  // next pointer for free/allocated 'all' list
+  PerRegionTable* _next;
+
+  // prev pointer for the allocated 'all' list
+  PerRegionTable* _prev;
+
+  // next pointer in collision list
+  PerRegionTable * _collision_list_next;
+
+  // Global free list of PRTs
+  static PerRegionTable* _free_list;
+
+protected:
+  // We need access in order to union things into the base table.
+  BitMap* bm() { return &_bm; }
+
+  void recount_occupied() {
+    _occupied = (jint) bm()->count_one_bits();
+  }
+
+  PerRegionTable(HeapRegion* hr) :
+    _hr(hr),
+    _occupied(0),
+    _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */),
+    _collision_list_next(NULL), _next(NULL), _prev(NULL)
+  {}
+
+  void add_card_work(CardIdx_t from_card, bool par) {
+    if (!_bm.at(from_card)) {
+      if (par) {
+        if (_bm.par_at_put(from_card, 1)) {
+          Atomic::inc(&_occupied);
+        }
+      } else {
+        _bm.at_put(from_card, 1);
+        _occupied++;
+      }
+    }
+  }
+
+  void add_reference_work(OopOrNarrowOopStar from, bool par) {
+    // Must make this robust in case "from" is not in "_hr", because of
+    // concurrency.
+
+    if (G1TraceHeapRegionRememberedSet) {
+      gclog_or_tty->print_cr("    PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").",
+                             p2i(from),
+                             UseCompressedOops
+                             ? p2i(oopDesc::load_decode_heap_oop((narrowOop*)from))
+                             : p2i(oopDesc::load_decode_heap_oop((oop*)from)));
+    }
+
+    HeapRegion* loc_hr = hr();
+    // If the test below fails, then this table was reused concurrently
+    // with this operation.  This is OK, since the old table was coarsened,
+    // and adding a bit to the new table is never incorrect.
+    // If the table used to belong to a continues humongous region and is
+    // now reused for the corresponding start humongous region, we need to
+    // make sure that we detect this. Thus, we call is_in_reserved_raw()
+    // instead of just is_in_reserved() here.
+    if (loc_hr->is_in_reserved_raw(from)) {
+      size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom());
+      CardIdx_t from_card = (CardIdx_t)
+          hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize);
+
+      assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion,
+             "Must be in range.");
+      add_card_work(from_card, par);
+    }
+  }
+
+public:
+
+  HeapRegion* hr() const { return _hr; }
+
+  jint occupied() const {
+    // Overkill, but if we ever need it...
+    // guarantee(_occupied == _bm.count_one_bits(), "Check");
+    return _occupied;
+  }
+
+  void init(HeapRegion* hr, bool clear_links_to_all_list) {
+    if (clear_links_to_all_list) {
+      set_next(NULL);
+      set_prev(NULL);
+    }
+    _hr = hr;
+    _collision_list_next = NULL;
+    _occupied = 0;
+    _bm.clear();
+  }
+
+  void add_reference(OopOrNarrowOopStar from) {
+    add_reference_work(from, /*parallel*/ true);
+  }
+
+  void seq_add_reference(OopOrNarrowOopStar from) {
+    add_reference_work(from, /*parallel*/ false);
+  }
+
+  void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) {
+    HeapWord* hr_bot = hr()->bottom();
+    size_t hr_first_card_index = ctbs->index_for(hr_bot);
+    bm()->set_intersection_at_offset(*card_bm, hr_first_card_index);
+    recount_occupied();
+  }
+
+  void add_card(CardIdx_t from_card_index) {
+    add_card_work(from_card_index, /*parallel*/ true);
+  }
+
+  void seq_add_card(CardIdx_t from_card_index) {
+    add_card_work(from_card_index, /*parallel*/ false);
+  }
+
+  // (Destructively) union the bitmap of the current table into the given
+  // bitmap (which is assumed to be of the same size.)
+  void union_bitmap_into(BitMap* bm) {
+    bm->set_union(_bm);
+  }
+
+  // Mem size in bytes.
+  size_t mem_size() const {
+    return sizeof(PerRegionTable) + _bm.size_in_words() * HeapWordSize;
+  }
+
+  // Requires "from" to be in "hr()".
+  bool contains_reference(OopOrNarrowOopStar from) const {
+    assert(hr()->is_in_reserved(from), "Precondition.");
+    size_t card_ind = pointer_delta(from, hr()->bottom(),
+                                    CardTableModRefBS::card_size);
+    return _bm.at(card_ind);
+  }
+
+  // Bulk-free the PRTs from prt to last, assumes that they are
+  // linked together using their _next field.
+  static void bulk_free(PerRegionTable* prt, PerRegionTable* last) {
+    while (true) {
+      PerRegionTable* fl = _free_list;
+      last->set_next(fl);
+      PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl);
+      if (res == fl) {
+        return;
+      }
+    }
+    ShouldNotReachHere();
+  }
+
+  static void free(PerRegionTable* prt) {
+    bulk_free(prt, prt);
+  }
+
+  // Returns an initialized PerRegionTable instance.
+  static PerRegionTable* alloc(HeapRegion* hr) {
+    PerRegionTable* fl = _free_list;
+    while (fl != NULL) {
+      PerRegionTable* nxt = fl->next();
+      PerRegionTable* res =
+        (PerRegionTable*)
+        Atomic::cmpxchg_ptr(nxt, &_free_list, fl);
+      if (res == fl) {
+        fl->init(hr, true);
+        return fl;
+      } else {
+        fl = _free_list;
+      }
+    }
+    assert(fl == NULL, "Loop condition.");
+    return new PerRegionTable(hr);
+  }
+
+  PerRegionTable* next() const { return _next; }
+  void set_next(PerRegionTable* next) { _next = next; }
+  PerRegionTable* prev() const { return _prev; }
+  void set_prev(PerRegionTable* prev) { _prev = prev; }
+
+  // Accessor and Modification routines for the pointer for the
+  // singly linked collision list that links the PRTs within the
+  // OtherRegionsTable::_fine_grain_regions hash table.
+  //
+  // It might be useful to also make the collision list doubly linked
+  // to avoid iteration over the collisions list during scrubbing/deletion.
+  // OTOH there might not be many collisions.
+
+  PerRegionTable* collision_list_next() const {
+    return _collision_list_next;
+  }
+
+  void set_collision_list_next(PerRegionTable* next) {
+    _collision_list_next = next;
+  }
+
+  PerRegionTable** collision_list_next_addr() {
+    return &_collision_list_next;
+  }
+
+  static size_t fl_mem_size() {
+    PerRegionTable* cur = _free_list;
+    size_t res = 0;
+    while (cur != NULL) {
+      res += cur->mem_size();
+      cur = cur->next();
+    }
+    return res;
+  }
+
+  static void test_fl_mem_size();
+};
+
+PerRegionTable* PerRegionTable::_free_list = NULL;
+
+size_t OtherRegionsTable::_max_fine_entries = 0;
+size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
+size_t OtherRegionsTable::_fine_eviction_stride = 0;
+size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
+
+OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) :
+  _g1h(G1CollectedHeap::heap()),
+  _hr(hr), _m(m),
+  _coarse_map(G1CollectedHeap::heap()->max_regions(),
+              false /* in-resource-area */),
+  _fine_grain_regions(NULL),
+  _first_all_fine_prts(NULL), _last_all_fine_prts(NULL),
+  _n_fine_entries(0), _n_coarse_entries(0),
+  _fine_eviction_start(0),
+  _sparse_table(hr)
+{
+  typedef PerRegionTable* PerRegionTablePtr;
+
+  if (_max_fine_entries == 0) {
+    assert(_mod_max_fine_entries_mask == 0, "Both or none.");
+    size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
+    _max_fine_entries = (size_t)1 << max_entries_log;
+    _mod_max_fine_entries_mask = _max_fine_entries - 1;
+
+    assert(_fine_eviction_sample_size == 0
+           && _fine_eviction_stride == 0, "All init at same time.");
+    _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
+    _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
+  }
+
+  _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries,
+                        mtGC, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
+
+  if (_fine_grain_regions == NULL) {
+    vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR,
+                          "Failed to allocate _fine_grain_entries.");
+  }
+
+  for (size_t i = 0; i < _max_fine_entries; i++) {
+    _fine_grain_regions[i] = NULL;
+  }
+}
+
+void OtherRegionsTable::link_to_all(PerRegionTable* prt) {
+  // We always append to the beginning of the list for convenience;
+  // the order of entries in this list does not matter.
+  if (_first_all_fine_prts != NULL) {
+    assert(_first_all_fine_prts->prev() == NULL, "invariant");
+    _first_all_fine_prts->set_prev(prt);
+    prt->set_next(_first_all_fine_prts);
+  } else {
+    // this is the first element we insert. Adjust the "last" pointer
+    _last_all_fine_prts = prt;
+    assert(prt->next() == NULL, "just checking");
+  }
+  // the new element is always the first element without a predecessor
+  prt->set_prev(NULL);
+  _first_all_fine_prts = prt;
+
+  assert(prt->prev() == NULL, "just checking");
+  assert(_first_all_fine_prts == prt, "just checking");
+  assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
+         (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
+         "just checking");
+  assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
+         "just checking");
+  assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
+         "just checking");
+}
+
+void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) {
+  if (prt->prev() != NULL) {
+    assert(_first_all_fine_prts != prt, "just checking");
+    prt->prev()->set_next(prt->next());
+    // removing the last element in the list?
+    if (_last_all_fine_prts == prt) {
+      _last_all_fine_prts = prt->prev();
+    }
+  } else {
+    assert(_first_all_fine_prts == prt, "just checking");
+    _first_all_fine_prts = prt->next();
+    // list is empty now?
+    if (_first_all_fine_prts == NULL) {
+      _last_all_fine_prts = NULL;
+    }
+  }
+
+  if (prt->next() != NULL) {
+    prt->next()->set_prev(prt->prev());
+  }
+
+  prt->set_next(NULL);
+  prt->set_prev(NULL);
+
+  assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
+         (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
+         "just checking");
+  assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
+         "just checking");
+  assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
+         "just checking");
+}
+
+int**  FromCardCache::_cache = NULL;
+uint   FromCardCache::_max_regions = 0;
+size_t FromCardCache::_static_mem_size = 0;
+
+void FromCardCache::initialize(uint n_par_rs, uint max_num_regions) {
+  guarantee(_cache == NULL, "Should not call this multiple times");
+
+  _max_regions = max_num_regions;
+  _cache = Padded2DArray<int, mtGC>::create_unfreeable(n_par_rs,
+                                                       _max_regions,
+                                                       &_static_mem_size);
+
+  invalidate(0, _max_regions);
+}
+
+void FromCardCache::invalidate(uint start_idx, size_t new_num_regions) {
+  guarantee((size_t)start_idx + new_num_regions <= max_uintx,
+            err_msg("Trying to invalidate beyond maximum region, from %u size "SIZE_FORMAT,
+                    start_idx, new_num_regions));
+  for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
+    uint end_idx = (start_idx + (uint)new_num_regions);
+    assert(end_idx <= _max_regions, "Must be within max.");
+    for (uint j = start_idx; j < end_idx; j++) {
+      set(i, j, InvalidCard);
+    }
+  }
+}
+
+#ifndef PRODUCT
+void FromCardCache::print(outputStream* out) {
+  for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
+    for (uint j = 0; j < _max_regions; j++) {
+      out->print_cr("_from_card_cache[%u][%u] = %d.",
+                    i, j, at(i, j));
+    }
+  }
+}
+#endif
+
+void FromCardCache::clear(uint region_idx) {
+  uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets();
+  for (uint i = 0; i < num_par_remsets; i++) {
+    set(i, region_idx, InvalidCard);
+  }
+}
+
+void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, uint tid) {
+  uint cur_hrm_ind = _hr->hrm_index();
+
+  if (G1TraceHeapRegionRememberedSet) {
+    gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").",
+                                                    p2i(from),
+                                                    UseCompressedOops
+                                                    ? p2i(oopDesc::load_decode_heap_oop((narrowOop*)from))
+                                                    : p2i(oopDesc::load_decode_heap_oop((oop*)from)));
+  }
+
+  int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift);
+
+  if (G1TraceHeapRegionRememberedSet) {
+    gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)",
+                  p2i(_hr->bottom()), from_card,
+                  FromCardCache::at(tid, cur_hrm_ind));
+  }
+
+  if (FromCardCache::contains_or_replace(tid, cur_hrm_ind, from_card)) {
+    if (G1TraceHeapRegionRememberedSet) {
+      gclog_or_tty->print_cr("  from-card cache hit.");
+    }
+    assert(contains_reference(from), "We just added it!");
+    return;
+  }
+
+  // Note that this may be a continued H region.
+  HeapRegion* from_hr = _g1h->heap_region_containing_raw(from);
+  RegionIdx_t from_hrm_ind = (RegionIdx_t) from_hr->hrm_index();
+
+  // If the region is already coarsened, return.
+  if (_coarse_map.at(from_hrm_ind)) {
+    if (G1TraceHeapRegionRememberedSet) {
+      gclog_or_tty->print_cr("  coarse map hit.");
+    }
+    assert(contains_reference(from), "We just added it!");
+    return;
+  }
+
+  // Otherwise find a per-region table to add it to.
+  size_t ind = from_hrm_ind & _mod_max_fine_entries_mask;
+  PerRegionTable* prt = find_region_table(ind, from_hr);
+  if (prt == NULL) {
+    MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
+    // Confirm that it's really not there...
+    prt = find_region_table(ind, from_hr);
+    if (prt == NULL) {
+
+      uintptr_t from_hr_bot_card_index =
+        uintptr_t(from_hr->bottom())
+          >> CardTableModRefBS::card_shift;
+      CardIdx_t card_index = from_card - from_hr_bot_card_index;
+      assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
+             "Must be in range.");
+      if (G1HRRSUseSparseTable &&
+          _sparse_table.add_card(from_hrm_ind, card_index)) {
+        if (G1RecordHRRSOops) {
+          HeapRegionRemSet::record(_hr, from);
+          if (G1TraceHeapRegionRememberedSet) {
+            gclog_or_tty->print("   Added card " PTR_FORMAT " to region "
+                                "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
+                                align_size_down(uintptr_t(from),
+                                                CardTableModRefBS::card_size),
+                                p2i(_hr->bottom()), p2i(from));
+          }
+        }
+        if (G1TraceHeapRegionRememberedSet) {
+          gclog_or_tty->print_cr("   added card to sparse table.");
+        }
+        assert(contains_reference_locked(from), "We just added it!");
+        return;
+      } else {
+        if (G1TraceHeapRegionRememberedSet) {
+          gclog_or_tty->print_cr("   [tid %u] sparse table entry "
+                        "overflow(f: %d, t: %u)",
+                        tid, from_hrm_ind, cur_hrm_ind);
+        }
+      }
+
+      if (_n_fine_entries == _max_fine_entries) {
+        prt = delete_region_table();
+        // There is no need to clear the links to the 'all' list here:
+        // prt will be reused immediately, i.e. remain in the 'all' list.
+        prt->init(from_hr, false /* clear_links_to_all_list */);
+      } else {
+        prt = PerRegionTable::alloc(from_hr);
+        link_to_all(prt);
+      }
+
+      PerRegionTable* first_prt = _fine_grain_regions[ind];
+      prt->set_collision_list_next(first_prt);
+      _fine_grain_regions[ind] = prt;
+      _n_fine_entries++;
+
+      if (G1HRRSUseSparseTable) {
+        // Transfer from sparse to fine-grain.
+        SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrm_ind);
+        assert(sprt_entry != NULL, "There should have been an entry");
+        for (int i = 0; i < SparsePRTEntry::cards_num(); i++) {
+          CardIdx_t c = sprt_entry->card(i);
+          if (c != SparsePRTEntry::NullEntry) {
+            prt->add_card(c);
+          }
+        }
+        // Now we can delete the sparse entry.
+        bool res = _sparse_table.delete_entry(from_hrm_ind);
+        assert(res, "It should have been there.");
+      }
+    }
+    assert(prt != NULL && prt->hr() == from_hr, "consequence");
+  }
+  // Note that we can't assert "prt->hr() == from_hr", because of the
+  // possibility of concurrent reuse.  But see head comment of
+  // OtherRegionsTable for why this is OK.
+  assert(prt != NULL, "Inv");
+
+  prt->add_reference(from);
+
+  if (G1RecordHRRSOops) {
+    HeapRegionRemSet::record(_hr, from);
+    if (G1TraceHeapRegionRememberedSet) {
+      gclog_or_tty->print("Added card " PTR_FORMAT " to region "
+                          "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
+                          align_size_down(uintptr_t(from),
+                                          CardTableModRefBS::card_size),
+                          p2i(_hr->bottom()), p2i(from));
+    }
+  }
+  assert(contains_reference(from), "We just added it!");
+}
+
+PerRegionTable*
+OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const {
+  assert(ind < _max_fine_entries, "Preconditions.");
+  PerRegionTable* prt = _fine_grain_regions[ind];
+  while (prt != NULL && prt->hr() != hr) {
+    prt = prt->collision_list_next();
+  }
+  // Loop postcondition is the method postcondition.
+  return prt;
+}
+
+jint OtherRegionsTable::_n_coarsenings = 0;
+
+PerRegionTable* OtherRegionsTable::delete_region_table() {
+  assert(_m->owned_by_self(), "Precondition");
+  assert(_n_fine_entries == _max_fine_entries, "Precondition");
+  PerRegionTable* max = NULL;
+  jint max_occ = 0;
+  PerRegionTable** max_prev;
+  size_t max_ind;
+
+  size_t i = _fine_eviction_start;
+  for (size_t k = 0; k < _fine_eviction_sample_size; k++) {
+    size_t ii = i;
+    // Make sure we get a non-NULL sample.
+    while (_fine_grain_regions[ii] == NULL) {
+      ii++;
+      if (ii == _max_fine_entries) ii = 0;
+      guarantee(ii != i, "We must find one.");
+    }
+    PerRegionTable** prev = &_fine_grain_regions[ii];
+    PerRegionTable* cur = *prev;
+    while (cur != NULL) {
+      jint cur_occ = cur->occupied();
+      if (max == NULL || cur_occ > max_occ) {
+        max = cur;
+        max_prev = prev;
+        max_ind = i;
+        max_occ = cur_occ;
+      }
+      prev = cur->collision_list_next_addr();
+      cur = cur->collision_list_next();
+    }
+    i = i + _fine_eviction_stride;
+    if (i >= _n_fine_entries) i = i - _n_fine_entries;
+  }
+
+  _fine_eviction_start++;
+
+  if (_fine_eviction_start >= _n_fine_entries) {
+    _fine_eviction_start -= _n_fine_entries;
+  }
+
+  guarantee(max != NULL, "Since _n_fine_entries > 0");
+
+  // Set the corresponding coarse bit.
+  size_t max_hrm_index = (size_t) max->hr()->hrm_index();
+  if (!_coarse_map.at(max_hrm_index)) {
+    _coarse_map.at_put(max_hrm_index, true);
+    _n_coarse_entries++;
+    if (G1TraceHeapRegionRememberedSet) {
+      gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] "
+                 "for region [" PTR_FORMAT "...] (" SIZE_FORMAT " coarse entries).\n",
+                 p2i(_hr->bottom()),
+                 p2i(max->hr()->bottom()),
+                 _n_coarse_entries);
+    }
+  }
+
+  // Unsplice.
+  *max_prev = max->collision_list_next();
+  Atomic::inc(&_n_coarsenings);
+  _n_fine_entries--;
+  return max;
+}
+
+void OtherRegionsTable::scrub(CardTableModRefBS* ctbs,
+                              BitMap* region_bm, BitMap* card_bm) {
+  // First eliminated garbage regions from the coarse map.
+  if (G1RSScrubVerbose) {
+    gclog_or_tty->print_cr("Scrubbing region %u:", _hr->hrm_index());
+  }
+
+  assert(_coarse_map.size() == region_bm->size(), "Precondition");
+  if (G1RSScrubVerbose) {
+    gclog_or_tty->print("   Coarse map: before = "SIZE_FORMAT"...",
+                        _n_coarse_entries);
+  }
+  _coarse_map.set_intersection(*region_bm);
+  _n_coarse_entries = _coarse_map.count_one_bits();
+  if (G1RSScrubVerbose) {
+    gclog_or_tty->print_cr("   after = "SIZE_FORMAT".", _n_coarse_entries);
+  }
+
+  // Now do the fine-grained maps.
+  for (size_t i = 0; i < _max_fine_entries; i++) {
+    PerRegionTable* cur = _fine_grain_regions[i];
+    PerRegionTable** prev = &_fine_grain_regions[i];
+    while (cur != NULL) {
+      PerRegionTable* nxt = cur->collision_list_next();
+      // If the entire region is dead, eliminate.
+      if (G1RSScrubVerbose) {
+        gclog_or_tty->print_cr("     For other region %u:",
+                               cur->hr()->hrm_index());
+      }
+      if (!region_bm->at((size_t) cur->hr()->hrm_index())) {
+        *prev = nxt;
+        cur->set_collision_list_next(NULL);
+        _n_fine_entries--;
+        if (G1RSScrubVerbose) {
+          gclog_or_tty->print_cr("          deleted via region map.");
+        }
+        unlink_from_all(cur);
+        PerRegionTable::free(cur);
+      } else {
+        // Do fine-grain elimination.
+        if (G1RSScrubVerbose) {
+          gclog_or_tty->print("          occ: before = %4d.", cur->occupied());
+        }
+        cur->scrub(ctbs, card_bm);
+        if (G1RSScrubVerbose) {
+          gclog_or_tty->print_cr("          after = %4d.", cur->occupied());
+        }
+        // Did that empty the table completely?
+        if (cur->occupied() == 0) {
+          *prev = nxt;
+          cur->set_collision_list_next(NULL);
+          _n_fine_entries--;
+          unlink_from_all(cur);
+          PerRegionTable::free(cur);
+        } else {
+          prev = cur->collision_list_next_addr();
+        }
+      }
+      cur = nxt;
+    }
+  }
+  // Since we may have deleted a from_card_cache entry from the RS, clear
+  // the FCC.
+  clear_fcc();
+}
+
+bool OtherRegionsTable::occupancy_less_or_equal_than(size_t limit) const {
+  if (limit <= (size_t)G1RSetSparseRegionEntries) {
+    return occ_coarse() == 0 && _first_all_fine_prts == NULL && occ_sparse() <= limit;
+  } else {
+    // Current uses of this method may only use values less than G1RSetSparseRegionEntries
+    // for the limit. The solution, comparing against occupied() would be too slow
+    // at this time.
+    Unimplemented();
+    return false;
+  }
+}
+
+bool OtherRegionsTable::is_empty() const {
+  return occ_sparse() == 0 && occ_coarse() == 0 && _first_all_fine_prts == NULL;
+}
+
+size_t OtherRegionsTable::occupied() const {
+  size_t sum = occ_fine();
+  sum += occ_sparse();
+  sum += occ_coarse();
+  return sum;
+}
+
+size_t OtherRegionsTable::occ_fine() const {
+  size_t sum = 0;
+
+  size_t num = 0;
+  PerRegionTable * cur = _first_all_fine_prts;
+  while (cur != NULL) {
+    sum += cur->occupied();
+    cur = cur->next();
+    num++;
+  }
+  guarantee(num == _n_fine_entries, "just checking");
+  return sum;
+}
+
+size_t OtherRegionsTable::occ_coarse() const {
+  return (_n_coarse_entries * HeapRegion::CardsPerRegion);
+}
+
+size_t OtherRegionsTable::occ_sparse() const {
+  return _sparse_table.occupied();
+}
+
+size_t OtherRegionsTable::mem_size() const {
+  size_t sum = 0;
+  // all PRTs are of the same size so it is sufficient to query only one of them.
+  if (_first_all_fine_prts != NULL) {
+    assert(_last_all_fine_prts != NULL &&
+      _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant");
+    sum += _first_all_fine_prts->mem_size() * _n_fine_entries;
+  }
+  sum += (sizeof(PerRegionTable*) * _max_fine_entries);
+  sum += (_coarse_map.size_in_words() * HeapWordSize);
+  sum += (_sparse_table.mem_size());
+  sum += sizeof(OtherRegionsTable) - sizeof(_sparse_table); // Avoid double counting above.
+  return sum;
+}
+
+size_t OtherRegionsTable::static_mem_size() {
+  return FromCardCache::static_mem_size();
+}
+
+size_t OtherRegionsTable::fl_mem_size() {
+  return PerRegionTable::fl_mem_size();
+}
+
+void OtherRegionsTable::clear_fcc() {
+  FromCardCache::clear(_hr->hrm_index());
+}
+
+void OtherRegionsTable::clear() {
+  // if there are no entries, skip this step
+  if (_first_all_fine_prts != NULL) {
+    guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
+    PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts);
+    memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0]));
+  } else {
+    guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking");
+  }
+
+  _first_all_fine_prts = _last_all_fine_prts = NULL;
+  _sparse_table.clear();
+  _coarse_map.clear();
+  _n_fine_entries = 0;
+  _n_coarse_entries = 0;
+
+  clear_fcc();
+}
+
+bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
+  // Cast away const in this case.
+  MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag);
+  return contains_reference_locked(from);
+}
+
+bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
+  HeapRegion* hr = _g1h->heap_region_containing_raw(from);
+  RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index();
+  // Is this region in the coarse map?
+  if (_coarse_map.at(hr_ind)) return true;
+
+  PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
+                                     hr);
+  if (prt != NULL) {
+    return prt->contains_reference(from);
+
+  } else {
+    uintptr_t from_card =
+      (uintptr_t(from) >> CardTableModRefBS::card_shift);
+    uintptr_t hr_bot_card_index =
+      uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift;
+    assert(from_card >= hr_bot_card_index, "Inv");
+    CardIdx_t card_index = from_card - hr_bot_card_index;
+    assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
+           "Must be in range.");
+    return _sparse_table.contains_card(hr_ind, card_index);
+  }
+}
+
+void
+OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
+  _sparse_table.do_cleanup_work(hrrs_cleanup_task);
+}
+
+// Determines how many threads can add records to an rset in parallel.
+// This can be done by either mutator threads together with the
+// concurrent refinement threads or GC threads.
+uint HeapRegionRemSet::num_par_rem_sets() {
+  return MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), (uint)ParallelGCThreads);
+}
+
+HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
+                                   HeapRegion* hr)
+  : _bosa(bosa),
+    _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true, Monitor::_safepoint_check_never),
+    _code_roots(), _other_regions(hr, &_m), _iter_state(Unclaimed), _iter_claimed(0) {
+  reset_for_par_iteration();
+}
+
+void HeapRegionRemSet::setup_remset_size() {
+  // Setup sparse and fine-grain tables sizes.
+  // table_size = base * (log(region_size / 1M) + 1)
+  const int LOG_M = 20;
+  int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0);
+  if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) {
+    G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1);
+  }
+  if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) {
+    G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1);
+  }
+  guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity");
+}
+
+bool HeapRegionRemSet::claim_iter() {
+  if (_iter_state != Unclaimed) return false;
+  jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed);
+  return (res == Unclaimed);
+}
+
+void HeapRegionRemSet::set_iter_complete() {
+  _iter_state = Complete;
+}
+
+bool HeapRegionRemSet::iter_is_complete() {
+  return _iter_state == Complete;
+}
+
+#ifndef PRODUCT
+void HeapRegionRemSet::print() {
+  HeapRegionRemSetIterator iter(this);
+  size_t card_index;
+  while (iter.has_next(card_index)) {
+    HeapWord* card_start =
+      G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
+    gclog_or_tty->print_cr("  Card " PTR_FORMAT, p2i(card_start));
+  }
+  if (iter.n_yielded() != occupied()) {
+    gclog_or_tty->print_cr("Yielded disagrees with occupied:");
+    gclog_or_tty->print_cr("  " SIZE_FORMAT_W(6) " yielded (" SIZE_FORMAT_W(6)
+                  " coarse, " SIZE_FORMAT_W(6) " fine).",
+                  iter.n_yielded(),
+                  iter.n_yielded_coarse(), iter.n_yielded_fine());
+    gclog_or_tty->print_cr("  " SIZE_FORMAT_W(6) " occ     (" SIZE_FORMAT_W(6)
+                           " coarse, " SIZE_FORMAT_W(6) " fine).",
+                  occupied(), occ_coarse(), occ_fine());
+  }
+  guarantee(iter.n_yielded() == occupied(),
+            "We should have yielded all the represented cards.");
+}
+#endif
+
+void HeapRegionRemSet::cleanup() {
+  SparsePRT::cleanup_all();
+}
+
+void HeapRegionRemSet::clear() {
+  MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
+  clear_locked();
+}
+
+void HeapRegionRemSet::clear_locked() {
+  _code_roots.clear();
+  _other_regions.clear();
+  assert(occupied_locked() == 0, "Should be clear.");
+  reset_for_par_iteration();
+}
+
+void HeapRegionRemSet::reset_for_par_iteration() {
+  _iter_state = Unclaimed;
+  _iter_claimed = 0;
+  // It's good to check this to make sure that the two methods are in sync.
+  assert(verify_ready_for_par_iteration(), "post-condition");
+}
+
+void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
+                             BitMap* region_bm, BitMap* card_bm) {
+  _other_regions.scrub(ctbs, region_bm, card_bm);
+}
+
+// Code roots support
+//
+// The code root set is protected by two separate locking schemes
+// When at safepoint the per-hrrs lock must be held during modifications
+// except when doing a full gc.
+// When not at safepoint the CodeCache_lock must be held during modifications.
+// When concurrent readers access the contains() function
+// (during the evacuation phase) no removals are allowed.
+
+void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
+  assert(nm != NULL, "sanity");
+  // Optimistic unlocked contains-check
+  if (!_code_roots.contains(nm)) {
+    MutexLockerEx ml(&_m, Mutex::_no_safepoint_check_flag);
+    add_strong_code_root_locked(nm);
+  }
+}
+
+void HeapRegionRemSet::add_strong_code_root_locked(nmethod* nm) {
+  assert(nm != NULL, "sanity");
+  _code_roots.add(nm);
+}
+
+void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
+  assert(nm != NULL, "sanity");
+  assert_locked_or_safepoint(CodeCache_lock);
+
+  MutexLockerEx ml(CodeCache_lock->owned_by_self() ? NULL : &_m, Mutex::_no_safepoint_check_flag);
+  _code_roots.remove(nm);
+
+  // Check that there were no duplicates
+  guarantee(!_code_roots.contains(nm), "duplicate entry found");
+}
+
+void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
+  _code_roots.nmethods_do(blk);
+}
+
+void HeapRegionRemSet::clean_strong_code_roots(HeapRegion* hr) {
+  _code_roots.clean(hr);
+}
+
+size_t HeapRegionRemSet::strong_code_roots_mem_size() {
+  return _code_roots.mem_size();
+}
+
+HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) :
+  _hrrs(hrrs),
+  _g1h(G1CollectedHeap::heap()),
+  _coarse_map(&hrrs->_other_regions._coarse_map),
+  _bosa(hrrs->_bosa),
+  _is(Sparse),
+  // Set these values so that we increment to the first region.
+  _coarse_cur_region_index(-1),
+  _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1),
+  _cur_card_in_prt(HeapRegion::CardsPerRegion),
+  _fine_cur_prt(NULL),
+  _n_yielded_coarse(0),
+  _n_yielded_fine(0),
+  _n_yielded_sparse(0),
+  _sparse_iter(&hrrs->_other_regions._sparse_table) {}
+
+bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) {
+  if (_hrrs->_other_regions._n_coarse_entries == 0) return false;
+  // Go to the next card.
+  _coarse_cur_region_cur_card++;
+  // Was the last the last card in the current region?
+  if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) {
+    // Yes: find the next region.  This may leave _coarse_cur_region_index
+    // Set to the last index, in which case there are no more coarse
+    // regions.
+    _coarse_cur_region_index =
+      (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1);
+    if ((size_t)_coarse_cur_region_index < _coarse_map->size()) {
+      _coarse_cur_region_cur_card = 0;
+      HeapWord* r_bot =
+        _g1h->region_at((uint) _coarse_cur_region_index)->bottom();
+      _cur_region_card_offset = _bosa->index_for(r_bot);
+    } else {
+      return false;
+    }
+  }
+  // If we didn't return false above, then we can yield a card.
+  card_index = _cur_region_card_offset + _coarse_cur_region_cur_card;
+  return true;
+}
+
+bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) {
+  if (fine_has_next()) {
+    _cur_card_in_prt =
+      _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
+  }
+  if (_cur_card_in_prt == HeapRegion::CardsPerRegion) {
+    // _fine_cur_prt may still be NULL in case if there are not PRTs at all for
+    // the remembered set.
+    if (_fine_cur_prt == NULL || _fine_cur_prt->next() == NULL) {
+      return false;
+    }
+    PerRegionTable* next_prt = _fine_cur_prt->next();
+    switch_to_prt(next_prt);
+    _cur_card_in_prt = _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
+  }
+
+  card_index = _cur_region_card_offset + _cur_card_in_prt;
+  guarantee(_cur_card_in_prt < HeapRegion::CardsPerRegion,
+            err_msg("Card index "SIZE_FORMAT" must be within the region", _cur_card_in_prt));
+  return true;
+}
+
+bool HeapRegionRemSetIterator::fine_has_next() {
+  return _cur_card_in_prt != HeapRegion::CardsPerRegion;
+}
+
+void HeapRegionRemSetIterator::switch_to_prt(PerRegionTable* prt) {
+  assert(prt != NULL, "Cannot switch to NULL prt");
+  _fine_cur_prt = prt;
+
+  HeapWord* r_bot = _fine_cur_prt->hr()->bottom();
+  _cur_region_card_offset = _bosa->index_for(r_bot);
+
+  // The bitmap scan for the PRT always scans from _cur_region_cur_card + 1.
+  // To avoid special-casing this start case, and not miss the first bitmap
+  // entry, initialize _cur_region_cur_card with -1 instead of 0.
+  _cur_card_in_prt = (size_t)-1;
+}
+
+bool HeapRegionRemSetIterator::has_next(size_t& card_index) {
+  switch (_is) {
+  case Sparse: {
+    if (_sparse_iter.has_next(card_index)) {
+      _n_yielded_sparse++;
+      return true;
+    }
+    // Otherwise, deliberate fall-through
+    _is = Fine;
+    PerRegionTable* initial_fine_prt = _hrrs->_other_regions._first_all_fine_prts;
+    if (initial_fine_prt != NULL) {
+      switch_to_prt(_hrrs->_other_regions._first_all_fine_prts);
+    }
+  }
+  case Fine:
+    if (fine_has_next(card_index)) {
+      _n_yielded_fine++;
+      return true;
+    }
+    // Otherwise, deliberate fall-through
+    _is = Coarse;
+  case Coarse:
+    if (coarse_has_next(card_index)) {
+      _n_yielded_coarse++;
+      return true;
+    }
+    // Otherwise...
+    break;
+  }
+  assert(ParallelGCThreads > 1 ||
+         n_yielded() == _hrrs->occupied(),
+         "Should have yielded all the cards in the rem set "
+         "(in the non-par case).");
+  return false;
+}
+
+
+
+OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL;
+HeapWord**          HeapRegionRemSet::_recorded_cards = NULL;
+HeapRegion**        HeapRegionRemSet::_recorded_regions = NULL;
+int                 HeapRegionRemSet::_n_recorded = 0;
+
+HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL;
+int*         HeapRegionRemSet::_recorded_event_index = NULL;
+int          HeapRegionRemSet::_n_recorded_events = 0;
+
+void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) {
+  if (_recorded_oops == NULL) {
+    assert(_n_recorded == 0
+           && _recorded_cards == NULL
+           && _recorded_regions == NULL,
+           "Inv");
+    _recorded_oops    = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded, mtGC);
+    _recorded_cards   = NEW_C_HEAP_ARRAY(HeapWord*,          MaxRecorded, mtGC);
+    _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*,        MaxRecorded, mtGC);
+  }
+  if (_n_recorded == MaxRecorded) {
+    gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded);
+  } else {
+    _recorded_cards[_n_recorded] =
+      (HeapWord*)align_size_down(uintptr_t(f),
+                                 CardTableModRefBS::card_size);
+    _recorded_oops[_n_recorded] = f;
+    _recorded_regions[_n_recorded] = hr;
+    _n_recorded++;
+  }
+}
+
+void HeapRegionRemSet::record_event(Event evnt) {
+  if (!G1RecordHRRSEvents) return;
+
+  if (_recorded_events == NULL) {
+    assert(_n_recorded_events == 0
+           && _recorded_event_index == NULL,
+           "Inv");
+    _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents, mtGC);
+    _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents, mtGC);
+  }
+  if (_n_recorded_events == MaxRecordedEvents) {
+    gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents);
+  } else {
+    _recorded_events[_n_recorded_events] = evnt;
+    _recorded_event_index[_n_recorded_events] = _n_recorded;
+    _n_recorded_events++;
+  }
+}
+
+void HeapRegionRemSet::print_event(outputStream* str, Event evnt) {
+  switch (evnt) {
+  case Event_EvacStart:
+    str->print("Evac Start");
+    break;
+  case Event_EvacEnd:
+    str->print("Evac End");
+    break;
+  case Event_RSUpdateEnd:
+    str->print("RS Update End");
+    break;
+  }
+}
+
+void HeapRegionRemSet::print_recorded() {
+  int cur_evnt = 0;
+  Event cur_evnt_kind;
+  int cur_evnt_ind = 0;
+  if (_n_recorded_events > 0) {
+    cur_evnt_kind = _recorded_events[cur_evnt];
+    cur_evnt_ind = _recorded_event_index[cur_evnt];
+  }
+
+  for (int i = 0; i < _n_recorded; i++) {
+    while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) {
+      gclog_or_tty->print("Event: ");
+      print_event(gclog_or_tty, cur_evnt_kind);
+      gclog_or_tty->cr();
+      cur_evnt++;
+      if (cur_evnt < MaxRecordedEvents) {
+        cur_evnt_kind = _recorded_events[cur_evnt];
+        cur_evnt_ind = _recorded_event_index[cur_evnt];
+      }
+    }
+    gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]"
+                        " for ref " PTR_FORMAT ".\n",
+                        p2i(_recorded_cards[i]), p2i(_recorded_regions[i]->bottom()),
+                        p2i(_recorded_oops[i]));
+  }
+}
+
+void HeapRegionRemSet::reset_for_cleanup_tasks() {
+  SparsePRT::reset_for_cleanup_tasks();
+}
+
+void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
+  _other_regions.do_cleanup_work(hrrs_cleanup_task);
+}
+
+void
+HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) {
+  SparsePRT::finish_cleanup_task(hrrs_cleanup_task);
+}
+
+#ifndef PRODUCT
+void PerRegionTable::test_fl_mem_size() {
+  PerRegionTable* dummy = alloc(NULL);
+
+  size_t min_prt_size = sizeof(void*) + dummy->bm()->size_in_words() * HeapWordSize;
+  assert(dummy->mem_size() > min_prt_size,
+         err_msg("PerRegionTable memory usage is suspiciously small, only has "SIZE_FORMAT" bytes. "
+                 "Should be at least "SIZE_FORMAT" bytes.", dummy->mem_size(), min_prt_size));
+  free(dummy);
+  guarantee(dummy->mem_size() == fl_mem_size(), "fl_mem_size() does not return the correct element size");
+  // try to reset the state
+  _free_list = NULL;
+  delete dummy;
+}
+
+void HeapRegionRemSet::test_prt() {
+  PerRegionTable::test_fl_mem_size();
+}
+
+void HeapRegionRemSet::test() {
+  os::sleep(Thread::current(), (jlong)5000, false);
+  G1CollectedHeap* g1h = G1CollectedHeap::heap();
+
+  // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same
+  // hash bucket.
+  HeapRegion* hr0 = g1h->region_at(0);
+  HeapRegion* hr1 = g1h->region_at(1);
+  HeapRegion* hr2 = g1h->region_at(5);
+  HeapRegion* hr3 = g1h->region_at(6);
+  HeapRegion* hr4 = g1h->region_at(7);
+  HeapRegion* hr5 = g1h->region_at(8);
+
+  HeapWord* hr1_start = hr1->bottom();
+  HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2;
+  HeapWord* hr1_last = hr1->end() - 1;
+
+  HeapWord* hr2_start = hr2->bottom();
+  HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2;
+  HeapWord* hr2_last = hr2->end() - 1;
+
+  HeapWord* hr3_start = hr3->bottom();
+  HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2;
+  HeapWord* hr3_last = hr3->end() - 1;
+
+  HeapRegionRemSet* hrrs = hr0->rem_set();
+
+  // Make three references from region 0x101...
+  hrrs->add_reference((OopOrNarrowOopStar)hr1_start);
+  hrrs->add_reference((OopOrNarrowOopStar)hr1_mid);
+  hrrs->add_reference((OopOrNarrowOopStar)hr1_last);
+
+  hrrs->add_reference((OopOrNarrowOopStar)hr2_start);
+  hrrs->add_reference((OopOrNarrowOopStar)hr2_mid);
+  hrrs->add_reference((OopOrNarrowOopStar)hr2_last);
+
+  hrrs->add_reference((OopOrNarrowOopStar)hr3_start);
+  hrrs->add_reference((OopOrNarrowOopStar)hr3_mid);
+  hrrs->add_reference((OopOrNarrowOopStar)hr3_last);
+
+  // Now cause a coarsening.
+  hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom());
+  hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom());
+
+  // Now, does iteration yield these three?
+  HeapRegionRemSetIterator iter(hrrs);
+  size_t sum = 0;
+  size_t card_index;
+  while (iter.has_next(card_index)) {
+    HeapWord* card_start =
+      G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
+    gclog_or_tty->print_cr("  Card " PTR_FORMAT ".", p2i(card_start));
+    sum++;
+  }
+  guarantee(sum == 11 - 3 + 2048, "Failure");
+  guarantee(sum == hrrs->occupied(), "Failure");
+}
+#endif