rev 6583 : 8047328: Change typedef CardIdx_t from int to uint16_t
Summary: Changed the typedef and made the necessary changes to code interacting with the SparsePRTEntry class.
Reviewed-by:
Contributed-by: andreas.sjoberg@oracle.com

   1 /*
   2  * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "gc_implementation/g1/concurrentG1Refine.hpp"
  27 #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp"
  28 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  29 #include "gc_implementation/g1/heapRegionRemSet.hpp"
  30 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
  31 #include "memory/allocation.hpp"
  32 #include "memory/padded.inline.hpp"
  33 #include "memory/space.inline.hpp"
  34 #include "oops/oop.inline.hpp"
  35 #include "utilities/bitMap.inline.hpp"
  36 #include "utilities/globalDefinitions.hpp"
  37 #include "utilities/growableArray.hpp"
  38 
  39 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  40 
  41 class PerRegionTable: public CHeapObj<mtGC> {
  42   friend class OtherRegionsTable;
  43   friend class HeapRegionRemSetIterator;
  44 
  45   HeapRegion*     _hr;
  46   BitMap          _bm;
  47   jint            _occupied;
  48 
  49   // next pointer for free/allocated 'all' list
  50   PerRegionTable* _next;
  51 
  52   // prev pointer for the allocated 'all' list
  53   PerRegionTable* _prev;
  54 
  55   // next pointer in collision list
  56   PerRegionTable * _collision_list_next;
  57 
  58   // Global free list of PRTs
  59   static PerRegionTable* _free_list;
  60 
  61 protected:
  62   // We need access in order to union things into the base table.
  63   BitMap* bm() { return &_bm; }
  64 
  65   void recount_occupied() {
  66     _occupied = (jint) bm()->count_one_bits();
  67   }
  68 
  69   PerRegionTable(HeapRegion* hr) :
  70     _hr(hr),
  71     _occupied(0),
  72     _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */),
  73     _collision_list_next(NULL), _next(NULL), _prev(NULL)
  74   {}
  75 
  76   void add_card_work(CardIdx_t from_card, bool par) {
  77     if (!_bm.at(from_card)) {
  78       if (par) {
  79         if (_bm.par_at_put(from_card, 1)) {
  80           Atomic::inc(&_occupied);
  81         }
  82       } else {
  83         _bm.at_put(from_card, 1);
  84         _occupied++;
  85       }
  86     }
  87   }
  88 
  89   void add_reference_work(OopOrNarrowOopStar from, bool par) {
  90     // Must make this robust in case "from" is not in "_hr", because of
  91     // concurrency.
  92 
  93     if (G1TraceHeapRegionRememberedSet) {
  94       gclog_or_tty->print_cr("    PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").",
  95                              from,
  96                              UseCompressedOops
  97                              ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
  98                              : (void *)oopDesc::load_decode_heap_oop((oop*)from));
  99     }
 100 
 101     HeapRegion* loc_hr = hr();
 102     // If the test below fails, then this table was reused concurrently
 103     // with this operation.  This is OK, since the old table was coarsened,
 104     // and adding a bit to the new table is never incorrect.
 105     // If the table used to belong to a continues humongous region and is
 106     // now reused for the corresponding start humongous region, we need to
 107     // make sure that we detect this. Thus, we call is_in_reserved_raw()
 108     // instead of just is_in_reserved() here.
 109     if (loc_hr->is_in_reserved_raw(from)) {
 110       size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom());
 111       CardIdx_t from_card = (CardIdx_t)
 112           (hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize));
 113 
 114       assert((size_t)from_card < HeapRegion::CardsPerRegion,
 115              "Must be in range.");
 116       add_card_work(from_card, par);
 117     }
 118   }
 119 
 120 public:
 121 
 122   HeapRegion* hr() const { return _hr; }
 123 
 124   jint occupied() const {
 125     // Overkill, but if we ever need it...
 126     // guarantee(_occupied == _bm.count_one_bits(), "Check");
 127     return _occupied;
 128   }
 129 
 130   void init(HeapRegion* hr, bool clear_links_to_all_list) {
 131     if (clear_links_to_all_list) {
 132       set_next(NULL);
 133       set_prev(NULL);
 134     }
 135     _hr = hr;
 136     _collision_list_next = NULL;
 137     _occupied = 0;
 138     _bm.clear();
 139   }
 140 
 141   void add_reference(OopOrNarrowOopStar from) {
 142     add_reference_work(from, /*parallel*/ true);
 143   }
 144 
 145   void seq_add_reference(OopOrNarrowOopStar from) {
 146     add_reference_work(from, /*parallel*/ false);
 147   }
 148 
 149   void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) {
 150     HeapWord* hr_bot = hr()->bottom();
 151     size_t hr_first_card_index = ctbs->index_for(hr_bot);
 152     bm()->set_intersection_at_offset(*card_bm, hr_first_card_index);
 153     recount_occupied();
 154   }
 155 
 156   void add_card(CardIdx_t from_card_index) {
 157     add_card_work(from_card_index, /*parallel*/ true);
 158   }
 159 
 160   void seq_add_card(CardIdx_t from_card_index) {
 161     add_card_work(from_card_index, /*parallel*/ false);
 162   }
 163 
 164   // (Destructively) union the bitmap of the current table into the given
 165   // bitmap (which is assumed to be of the same size.)
 166   void union_bitmap_into(BitMap* bm) {
 167     bm->set_union(_bm);
 168   }
 169 
 170   // Mem size in bytes.
 171   size_t mem_size() const {
 172     return sizeof(PerRegionTable) + _bm.size_in_words() * HeapWordSize;
 173   }
 174 
 175   // Requires "from" to be in "hr()".
 176   bool contains_reference(OopOrNarrowOopStar from) const {
 177     assert(hr()->is_in_reserved(from), "Precondition.");
 178     size_t card_ind = pointer_delta(from, hr()->bottom(),
 179                                     CardTableModRefBS::card_size);
 180     return _bm.at(card_ind);
 181   }
 182 
 183   // Bulk-free the PRTs from prt to last, assumes that they are
 184   // linked together using their _next field.
 185   static void bulk_free(PerRegionTable* prt, PerRegionTable* last) {
 186     while (true) {
 187       PerRegionTable* fl = _free_list;
 188       last->set_next(fl);
 189       PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl);
 190       if (res == fl) {
 191         return;
 192       }
 193     }
 194     ShouldNotReachHere();
 195   }
 196 
 197   static void free(PerRegionTable* prt) {
 198     bulk_free(prt, prt);
 199   }
 200 
 201   // Returns an initialized PerRegionTable instance.
 202   static PerRegionTable* alloc(HeapRegion* hr) {
 203     PerRegionTable* fl = _free_list;
 204     while (fl != NULL) {
 205       PerRegionTable* nxt = fl->next();
 206       PerRegionTable* res =
 207         (PerRegionTable*)
 208         Atomic::cmpxchg_ptr(nxt, &_free_list, fl);
 209       if (res == fl) {
 210         fl->init(hr, true);
 211         return fl;
 212       } else {
 213         fl = _free_list;
 214       }
 215     }
 216     assert(fl == NULL, "Loop condition.");
 217     return new PerRegionTable(hr);
 218   }
 219 
 220   PerRegionTable* next() const { return _next; }
 221   void set_next(PerRegionTable* next) { _next = next; }
 222   PerRegionTable* prev() const { return _prev; }
 223   void set_prev(PerRegionTable* prev) { _prev = prev; }
 224 
 225   // Accessor and Modification routines for the pointer for the
 226   // singly linked collision list that links the PRTs within the
 227   // OtherRegionsTable::_fine_grain_regions hash table.
 228   //
 229   // It might be useful to also make the collision list doubly linked
 230   // to avoid iteration over the collisions list during scrubbing/deletion.
 231   // OTOH there might not be many collisions.
 232 
 233   PerRegionTable* collision_list_next() const {
 234     return _collision_list_next;
 235   }
 236 
 237   void set_collision_list_next(PerRegionTable* next) {
 238     _collision_list_next = next;
 239   }
 240 
 241   PerRegionTable** collision_list_next_addr() {
 242     return &_collision_list_next;
 243   }
 244 
 245   static size_t fl_mem_size() {
 246     PerRegionTable* cur = _free_list;
 247     size_t res = 0;
 248     while (cur != NULL) {
 249       res += cur->mem_size();
 250       cur = cur->next();
 251     }
 252     return res;
 253   }
 254 
 255   static void test_fl_mem_size();
 256 };
 257 
 258 PerRegionTable* PerRegionTable::_free_list = NULL;
 259 
 260 size_t OtherRegionsTable::_max_fine_entries = 0;
 261 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
 262 size_t OtherRegionsTable::_fine_eviction_stride = 0;
 263 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
 264 
 265 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) :
 266   _g1h(G1CollectedHeap::heap()),
 267   _hr(hr), _m(m),
 268   _coarse_map(G1CollectedHeap::heap()->max_regions(),
 269               false /* in-resource-area */),
 270   _fine_grain_regions(NULL),
 271   _first_all_fine_prts(NULL), _last_all_fine_prts(NULL),
 272   _n_fine_entries(0), _n_coarse_entries(0),
 273   _fine_eviction_start(0),
 274   _sparse_table(hr)
 275 {
 276   typedef PerRegionTable* PerRegionTablePtr;
 277 
 278   if (_max_fine_entries == 0) {
 279     assert(_mod_max_fine_entries_mask == 0, "Both or none.");
 280     size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
 281     _max_fine_entries = (size_t)1 << max_entries_log;
 282     _mod_max_fine_entries_mask = _max_fine_entries - 1;
 283 
 284     assert(_fine_eviction_sample_size == 0
 285            && _fine_eviction_stride == 0, "All init at same time.");
 286     _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
 287     _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
 288   }
 289 
 290   _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries,
 291                         mtGC, 0, AllocFailStrategy::RETURN_NULL);
 292 
 293   if (_fine_grain_regions == NULL) {
 294     vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR,
 295                           "Failed to allocate _fine_grain_entries.");
 296   }
 297 
 298   for (size_t i = 0; i < _max_fine_entries; i++) {
 299     _fine_grain_regions[i] = NULL;
 300   }
 301 }
 302 
 303 void OtherRegionsTable::link_to_all(PerRegionTable* prt) {
 304   // We always append to the beginning of the list for convenience;
 305   // the order of entries in this list does not matter.
 306   if (_first_all_fine_prts != NULL) {
 307     assert(_first_all_fine_prts->prev() == NULL, "invariant");
 308     _first_all_fine_prts->set_prev(prt);
 309     prt->set_next(_first_all_fine_prts);
 310   } else {
 311     // this is the first element we insert. Adjust the "last" pointer
 312     _last_all_fine_prts = prt;
 313     assert(prt->next() == NULL, "just checking");
 314   }
 315   // the new element is always the first element without a predecessor
 316   prt->set_prev(NULL);
 317   _first_all_fine_prts = prt;
 318 
 319   assert(prt->prev() == NULL, "just checking");
 320   assert(_first_all_fine_prts == prt, "just checking");
 321   assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
 322          (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
 323          "just checking");
 324   assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
 325          "just checking");
 326   assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
 327          "just checking");
 328 }
 329 
 330 void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) {
 331   if (prt->prev() != NULL) {
 332     assert(_first_all_fine_prts != prt, "just checking");
 333     prt->prev()->set_next(prt->next());
 334     // removing the last element in the list?
 335     if (_last_all_fine_prts == prt) {
 336       _last_all_fine_prts = prt->prev();
 337     }
 338   } else {
 339     assert(_first_all_fine_prts == prt, "just checking");
 340     _first_all_fine_prts = prt->next();
 341     // list is empty now?
 342     if (_first_all_fine_prts == NULL) {
 343       _last_all_fine_prts = NULL;
 344     }
 345   }
 346 
 347   if (prt->next() != NULL) {
 348     prt->next()->set_prev(prt->prev());
 349   }
 350 
 351   prt->set_next(NULL);
 352   prt->set_prev(NULL);
 353 
 354   assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
 355          (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
 356          "just checking");
 357   assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
 358          "just checking");
 359   assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
 360          "just checking");
 361 }
 362 
 363 int**  FromCardCache::_cache = NULL;
 364 uint   FromCardCache::_max_regions = 0;
 365 size_t FromCardCache::_static_mem_size = 0;
 366 
 367 void FromCardCache::initialize(uint n_par_rs, uint max_num_regions) {
 368   guarantee(_cache == NULL, "Should not call this multiple times");
 369 
 370   _max_regions = max_num_regions;
 371   _cache = Padded2DArray<int, mtGC>::create_unfreeable(n_par_rs,
 372                                                        _max_regions,
 373                                                        &_static_mem_size);
 374 
 375   for (uint i = 0; i < n_par_rs; i++) {
 376     for (uint j = 0; j < _max_regions; j++) {
 377       set(i, j, InvalidCard);
 378     }
 379   }
 380 }
 381 
 382 void FromCardCache::shrink(uint new_num_regions) {
 383   for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
 384     assert(new_num_regions <= _max_regions, "Must be within max.");
 385     for (uint j = new_num_regions; j < _max_regions; j++) {
 386       set(i, j, InvalidCard);
 387     }
 388   }
 389 }
 390 
 391 #ifndef PRODUCT
 392 void FromCardCache::print(outputStream* out) {
 393   for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
 394     for (uint j = 0; j < _max_regions; j++) {
 395       out->print_cr("_from_card_cache[%u][%u] = %d.",
 396                     i, j, at(i, j));
 397     }
 398   }
 399 }
 400 #endif
 401 
 402 void FromCardCache::clear(uint region_idx) {
 403   uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets();
 404   for (uint i = 0; i < num_par_remsets; i++) {
 405     set(i, region_idx, InvalidCard);
 406   }
 407 }
 408 
 409 void OtherRegionsTable::init_from_card_cache(uint max_regions) {
 410   FromCardCache::initialize(HeapRegionRemSet::num_par_rem_sets(), max_regions);
 411 }
 412 
 413 void OtherRegionsTable::shrink_from_card_cache(uint new_num_regions) {
 414   FromCardCache::shrink(new_num_regions);
 415 }
 416 
 417 void OtherRegionsTable::print_from_card_cache() {
 418   FromCardCache::print();
 419 }
 420 
 421 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, int tid) {
 422   uint cur_hrs_ind = hr()->hrs_index();
 423 
 424   if (G1TraceHeapRegionRememberedSet) {
 425     gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").",
 426                                                     from,
 427                                                     UseCompressedOops
 428                                                     ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
 429                                                     : (void *)oopDesc::load_decode_heap_oop((oop*)from));
 430   }
 431 
 432   int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift);
 433 
 434   if (G1TraceHeapRegionRememberedSet) {
 435     gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)",
 436                   hr()->bottom(), from_card,
 437                   FromCardCache::at((uint)tid, cur_hrs_ind));
 438   }
 439 
 440   if (FromCardCache::contains_or_replace((uint)tid, cur_hrs_ind, from_card)) {
 441     if (G1TraceHeapRegionRememberedSet) {
 442       gclog_or_tty->print_cr("  from-card cache hit.");
 443     }
 444     assert(contains_reference(from), "We just added it!");
 445     return;
 446   }
 447 
 448   // Note that this may be a continued H region.
 449   HeapRegion* from_hr = _g1h->heap_region_containing_raw(from);
 450   RegionIdx_t from_hrs_ind = (RegionIdx_t) from_hr->hrs_index();
 451 
 452   // If the region is already coarsened, return.
 453   if (_coarse_map.at(from_hrs_ind)) {
 454     if (G1TraceHeapRegionRememberedSet) {
 455       gclog_or_tty->print_cr("  coarse map hit.");
 456     }
 457     assert(contains_reference(from), "We just added it!");
 458     return;
 459   }
 460 
 461   // Otherwise find a per-region table to add it to.
 462   size_t ind = from_hrs_ind & _mod_max_fine_entries_mask;
 463   PerRegionTable* prt = find_region_table(ind, from_hr);
 464   if (prt == NULL) {
 465     MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
 466     // Confirm that it's really not there...
 467     prt = find_region_table(ind, from_hr);
 468     if (prt == NULL) {
 469 
 470       uintptr_t from_hr_bot_card_index =
 471         uintptr_t(from_hr->bottom())
 472           >> CardTableModRefBS::card_shift;
 473       CardIdx_t card_index = from_card - from_hr_bot_card_index;
 474       assert((size_t)card_index < HeapRegion::CardsPerRegion,
 475              "Must be in range.");
 476       if (G1HRRSUseSparseTable &&
 477           _sparse_table.add_card(from_hrs_ind, card_index)) {
 478         if (G1RecordHRRSOops) {
 479           HeapRegionRemSet::record(hr(), from);
 480           if (G1TraceHeapRegionRememberedSet) {
 481             gclog_or_tty->print("   Added card " PTR_FORMAT " to region "
 482                                 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
 483                                 align_size_down(uintptr_t(from),
 484                                                 CardTableModRefBS::card_size),
 485                                 hr()->bottom(), from);
 486           }
 487         }
 488         if (G1TraceHeapRegionRememberedSet) {
 489           gclog_or_tty->print_cr("   added card to sparse table.");
 490         }
 491         assert(contains_reference_locked(from), "We just added it!");
 492         return;
 493       } else {
 494         if (G1TraceHeapRegionRememberedSet) {
 495           gclog_or_tty->print_cr("   [tid %d] sparse table entry "
 496                         "overflow(f: %d, t: %u)",
 497                         tid, from_hrs_ind, cur_hrs_ind);
 498         }
 499       }
 500 
 501       if (_n_fine_entries == _max_fine_entries) {
 502         prt = delete_region_table();
 503         // There is no need to clear the links to the 'all' list here:
 504         // prt will be reused immediately, i.e. remain in the 'all' list.
 505         prt->init(from_hr, false /* clear_links_to_all_list */);
 506       } else {
 507         prt = PerRegionTable::alloc(from_hr);
 508         link_to_all(prt);
 509       }
 510 
 511       PerRegionTable* first_prt = _fine_grain_regions[ind];
 512       prt->set_collision_list_next(first_prt);
 513       _fine_grain_regions[ind] = prt;
 514       _n_fine_entries++;
 515 
 516       if (G1HRRSUseSparseTable) {
 517         // Transfer from sparse to fine-grain.
 518         SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrs_ind);
 519         assert(sprt_entry != NULL, "There should have been an entry");
 520         for (int i = 0; i < sprt_entry->num_valid_cards(); i++) {
 521           CardIdx_t c = sprt_entry->card(i);

 522           prt->add_card(c);
 523         }

 524         // Now we can delete the sparse entry.
 525         bool res = _sparse_table.delete_entry(from_hrs_ind);
 526         assert(res, "It should have been there.");
 527       }
 528     }
 529     assert(prt != NULL && prt->hr() == from_hr, "consequence");
 530   }
 531   // Note that we can't assert "prt->hr() == from_hr", because of the
 532   // possibility of concurrent reuse.  But see head comment of
 533   // OtherRegionsTable for why this is OK.
 534   assert(prt != NULL, "Inv");
 535 
 536   prt->add_reference(from);
 537 
 538   if (G1RecordHRRSOops) {
 539     HeapRegionRemSet::record(hr(), from);
 540     if (G1TraceHeapRegionRememberedSet) {
 541       gclog_or_tty->print("Added card " PTR_FORMAT " to region "
 542                           "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
 543                           align_size_down(uintptr_t(from),
 544                                           CardTableModRefBS::card_size),
 545                           hr()->bottom(), from);
 546     }
 547   }
 548   assert(contains_reference(from), "We just added it!");
 549 }
 550 
 551 PerRegionTable*
 552 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const {
 553   assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
 554   PerRegionTable* prt = _fine_grain_regions[ind];
 555   while (prt != NULL && prt->hr() != hr) {
 556     prt = prt->collision_list_next();
 557   }
 558   // Loop postcondition is the method postcondition.
 559   return prt;
 560 }
 561 
 562 jint OtherRegionsTable::_n_coarsenings = 0;
 563 
 564 PerRegionTable* OtherRegionsTable::delete_region_table() {
 565   assert(_m->owned_by_self(), "Precondition");
 566   assert(_n_fine_entries == _max_fine_entries, "Precondition");
 567   PerRegionTable* max = NULL;
 568   jint max_occ = 0;
 569   PerRegionTable** max_prev;
 570   size_t max_ind;
 571 
 572   size_t i = _fine_eviction_start;
 573   for (size_t k = 0; k < _fine_eviction_sample_size; k++) {
 574     size_t ii = i;
 575     // Make sure we get a non-NULL sample.
 576     while (_fine_grain_regions[ii] == NULL) {
 577       ii++;
 578       if (ii == _max_fine_entries) ii = 0;
 579       guarantee(ii != i, "We must find one.");
 580     }
 581     PerRegionTable** prev = &_fine_grain_regions[ii];
 582     PerRegionTable* cur = *prev;
 583     while (cur != NULL) {
 584       jint cur_occ = cur->occupied();
 585       if (max == NULL || cur_occ > max_occ) {
 586         max = cur;
 587         max_prev = prev;
 588         max_ind = i;
 589         max_occ = cur_occ;
 590       }
 591       prev = cur->collision_list_next_addr();
 592       cur = cur->collision_list_next();
 593     }
 594     i = i + _fine_eviction_stride;
 595     if (i >= _n_fine_entries) i = i - _n_fine_entries;
 596   }
 597 
 598   _fine_eviction_start++;
 599 
 600   if (_fine_eviction_start >= _n_fine_entries) {
 601     _fine_eviction_start -= _n_fine_entries;
 602   }
 603 
 604   guarantee(max != NULL, "Since _n_fine_entries > 0");
 605 
 606   // Set the corresponding coarse bit.
 607   size_t max_hrs_index = (size_t) max->hr()->hrs_index();
 608   if (!_coarse_map.at(max_hrs_index)) {
 609     _coarse_map.at_put(max_hrs_index, true);
 610     _n_coarse_entries++;
 611     if (G1TraceHeapRegionRememberedSet) {
 612       gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] "
 613                  "for region [" PTR_FORMAT "...] (" SIZE_FORMAT " coarse entries).\n",
 614                  hr()->bottom(),
 615                  max->hr()->bottom(),
 616                  _n_coarse_entries);
 617     }
 618   }
 619 
 620   // Unsplice.
 621   *max_prev = max->collision_list_next();
 622   Atomic::inc(&_n_coarsenings);
 623   _n_fine_entries--;
 624   return max;
 625 }
 626 
 627 
 628 // At present, this must be called stop-world single-threaded.
 629 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs,
 630                               BitMap* region_bm, BitMap* card_bm) {
 631   // First eliminated garbage regions from the coarse map.
 632   if (G1RSScrubVerbose) {
 633     gclog_or_tty->print_cr("Scrubbing region %u:", hr()->hrs_index());
 634   }
 635 
 636   assert(_coarse_map.size() == region_bm->size(), "Precondition");
 637   if (G1RSScrubVerbose) {
 638     gclog_or_tty->print("   Coarse map: before = "SIZE_FORMAT"...",
 639                         _n_coarse_entries);
 640   }
 641   _coarse_map.set_intersection(*region_bm);
 642   _n_coarse_entries = _coarse_map.count_one_bits();
 643   if (G1RSScrubVerbose) {
 644     gclog_or_tty->print_cr("   after = "SIZE_FORMAT".", _n_coarse_entries);
 645   }
 646 
 647   // Now do the fine-grained maps.
 648   for (size_t i = 0; i < _max_fine_entries; i++) {
 649     PerRegionTable* cur = _fine_grain_regions[i];
 650     PerRegionTable** prev = &_fine_grain_regions[i];
 651     while (cur != NULL) {
 652       PerRegionTable* nxt = cur->collision_list_next();
 653       // If the entire region is dead, eliminate.
 654       if (G1RSScrubVerbose) {
 655         gclog_or_tty->print_cr("     For other region %u:",
 656                                cur->hr()->hrs_index());
 657       }
 658       if (!region_bm->at((size_t) cur->hr()->hrs_index())) {
 659         *prev = nxt;
 660         cur->set_collision_list_next(NULL);
 661         _n_fine_entries--;
 662         if (G1RSScrubVerbose) {
 663           gclog_or_tty->print_cr("          deleted via region map.");
 664         }
 665         unlink_from_all(cur);
 666         PerRegionTable::free(cur);
 667       } else {
 668         // Do fine-grain elimination.
 669         if (G1RSScrubVerbose) {
 670           gclog_or_tty->print("          occ: before = %4d.", cur->occupied());
 671         }
 672         cur->scrub(ctbs, card_bm);
 673         if (G1RSScrubVerbose) {
 674           gclog_or_tty->print_cr("          after = %4d.", cur->occupied());
 675         }
 676         // Did that empty the table completely?
 677         if (cur->occupied() == 0) {
 678           *prev = nxt;
 679           cur->set_collision_list_next(NULL);
 680           _n_fine_entries--;
 681           unlink_from_all(cur);
 682           PerRegionTable::free(cur);
 683         } else {
 684           prev = cur->collision_list_next_addr();
 685         }
 686       }
 687       cur = nxt;
 688     }
 689   }
 690   // Since we may have deleted a from_card_cache entry from the RS, clear
 691   // the FCC.
 692   clear_fcc();
 693 }
 694 
 695 
 696 size_t OtherRegionsTable::occupied() const {
 697   size_t sum = occ_fine();
 698   sum += occ_sparse();
 699   sum += occ_coarse();
 700   return sum;
 701 }
 702 
 703 size_t OtherRegionsTable::occ_fine() const {
 704   size_t sum = 0;
 705 
 706   size_t num = 0;
 707   PerRegionTable * cur = _first_all_fine_prts;
 708   while (cur != NULL) {
 709     sum += cur->occupied();
 710     cur = cur->next();
 711     num++;
 712   }
 713   guarantee(num == _n_fine_entries, "just checking");
 714   return sum;
 715 }
 716 
 717 size_t OtherRegionsTable::occ_coarse() const {
 718   return (_n_coarse_entries * HeapRegion::CardsPerRegion);
 719 }
 720 
 721 size_t OtherRegionsTable::occ_sparse() const {
 722   return _sparse_table.occupied();
 723 }
 724 
 725 size_t OtherRegionsTable::mem_size() const {
 726   size_t sum = 0;
 727   // all PRTs are of the same size so it is sufficient to query only one of them.
 728   if (_first_all_fine_prts != NULL) {
 729     assert(_last_all_fine_prts != NULL &&
 730       _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant");
 731     sum += _first_all_fine_prts->mem_size() * _n_fine_entries;
 732   }
 733   sum += (sizeof(PerRegionTable*) * _max_fine_entries);
 734   sum += (_coarse_map.size_in_words() * HeapWordSize);
 735   sum += (_sparse_table.mem_size());
 736   sum += sizeof(OtherRegionsTable) - sizeof(_sparse_table); // Avoid double counting above.
 737   return sum;
 738 }
 739 
 740 size_t OtherRegionsTable::static_mem_size() {
 741   return FromCardCache::static_mem_size();
 742 }
 743 
 744 size_t OtherRegionsTable::fl_mem_size() {
 745   return PerRegionTable::fl_mem_size();
 746 }
 747 
 748 void OtherRegionsTable::clear_fcc() {
 749   FromCardCache::clear(hr()->hrs_index());
 750 }
 751 
 752 void OtherRegionsTable::clear() {
 753   // if there are no entries, skip this step
 754   if (_first_all_fine_prts != NULL) {
 755     guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
 756     PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts);
 757     memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0]));
 758   } else {
 759     guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking");
 760   }
 761 
 762   _first_all_fine_prts = _last_all_fine_prts = NULL;
 763   _sparse_table.clear();
 764   _coarse_map.clear();
 765   _n_fine_entries = 0;
 766   _n_coarse_entries = 0;
 767 
 768   clear_fcc();
 769 }
 770 
 771 bool OtherRegionsTable::del_single_region_table(size_t ind,
 772                                                 HeapRegion* hr) {
 773   assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
 774   PerRegionTable** prev_addr = &_fine_grain_regions[ind];
 775   PerRegionTable* prt = *prev_addr;
 776   while (prt != NULL && prt->hr() != hr) {
 777     prev_addr = prt->collision_list_next_addr();
 778     prt = prt->collision_list_next();
 779   }
 780   if (prt != NULL) {
 781     assert(prt->hr() == hr, "Loop postcondition.");
 782     *prev_addr = prt->collision_list_next();
 783     unlink_from_all(prt);
 784     PerRegionTable::free(prt);
 785     _n_fine_entries--;
 786     return true;
 787   } else {
 788     return false;
 789   }
 790 }
 791 
 792 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
 793   // Cast away const in this case.
 794   MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag);
 795   return contains_reference_locked(from);
 796 }
 797 
 798 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
 799   HeapRegion* hr = _g1h->heap_region_containing_raw(from);
 800   RegionIdx_t hr_ind = (RegionIdx_t) hr->hrs_index();
 801   // Is this region in the coarse map?
 802   if (_coarse_map.at(hr_ind)) return true;
 803 
 804   PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
 805                                      hr);
 806   if (prt != NULL) {
 807     return prt->contains_reference(from);
 808 
 809   } else {
 810     uintptr_t from_card =
 811       (uintptr_t(from) >> CardTableModRefBS::card_shift);
 812     uintptr_t hr_bot_card_index =
 813       uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift;
 814     assert(from_card >= hr_bot_card_index, "Inv");
 815     CardIdx_t card_index = from_card - hr_bot_card_index;
 816     assert((size_t)card_index < HeapRegion::CardsPerRegion,
 817            "Must be in range.");
 818     return _sparse_table.contains_card(hr_ind, card_index);
 819   }
 820 }
 821 
 822 void
 823 OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
 824   _sparse_table.do_cleanup_work(hrrs_cleanup_task);
 825 }
 826 
 827 // Determines how many threads can add records to an rset in parallel.
 828 // This can be done by either mutator threads together with the
 829 // concurrent refinement threads or GC threads.
 830 uint HeapRegionRemSet::num_par_rem_sets() {
 831   return MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), (uint)ParallelGCThreads);
 832 }
 833 
 834 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
 835                                    HeapRegion* hr)
 836   : _bosa(bosa),
 837     _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrs_index()), true),
 838     _code_roots(), _other_regions(hr, &_m) {
 839   reset_for_par_iteration();
 840 }
 841 
 842 void HeapRegionRemSet::setup_remset_size() {
 843   // Setup sparse and fine-grain tables sizes.
 844   // table_size = base * (log(region_size / 1M) + 1)
 845   const int LOG_M = 20;
 846   int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0);
 847   if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) {
 848     G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1);
 849   }
 850   if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) {
 851     G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1);
 852   }
 853   guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity");
 854 }
 855 
 856 bool HeapRegionRemSet::claim_iter() {
 857   if (_iter_state != Unclaimed) return false;
 858   jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed);
 859   return (res == Unclaimed);
 860 }
 861 
 862 void HeapRegionRemSet::set_iter_complete() {
 863   _iter_state = Complete;
 864 }
 865 
 866 bool HeapRegionRemSet::iter_is_complete() {
 867   return _iter_state == Complete;
 868 }
 869 
 870 #ifndef PRODUCT
 871 void HeapRegionRemSet::print() {
 872   HeapRegionRemSetIterator iter(this);
 873   size_t card_index;
 874   while (iter.has_next(card_index)) {
 875     HeapWord* card_start =
 876       G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
 877     gclog_or_tty->print_cr("  Card " PTR_FORMAT, card_start);
 878   }
 879   if (iter.n_yielded() != occupied()) {
 880     gclog_or_tty->print_cr("Yielded disagrees with occupied:");
 881     gclog_or_tty->print_cr("  " SIZE_FORMAT_W(6) " yielded (" SIZE_FORMAT_W(6)
 882                   " coarse, " SIZE_FORMAT_W(6) " fine).",
 883                   iter.n_yielded(),
 884                   iter.n_yielded_coarse(), iter.n_yielded_fine());
 885     gclog_or_tty->print_cr("  " SIZE_FORMAT_W(6) " occ     (" SIZE_FORMAT_W(6)
 886                            " coarse, " SIZE_FORMAT_W(6) " fine).",
 887                   occupied(), occ_coarse(), occ_fine());
 888   }
 889   guarantee(iter.n_yielded() == occupied(),
 890             "We should have yielded all the represented cards.");
 891 }
 892 #endif
 893 
 894 void HeapRegionRemSet::cleanup() {
 895   SparsePRT::cleanup_all();
 896 }
 897 
 898 void HeapRegionRemSet::clear() {
 899   MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
 900   clear_locked();
 901 }
 902 
 903 void HeapRegionRemSet::clear_locked() {
 904   _code_roots.clear();
 905   _other_regions.clear();
 906   assert(occupied_locked() == 0, "Should be clear.");
 907   reset_for_par_iteration();
 908 }
 909 
 910 void HeapRegionRemSet::reset_for_par_iteration() {
 911   _iter_state = Unclaimed;
 912   _iter_claimed = 0;
 913   // It's good to check this to make sure that the two methods are in sync.
 914   assert(verify_ready_for_par_iteration(), "post-condition");
 915 }
 916 
 917 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
 918                              BitMap* region_bm, BitMap* card_bm) {
 919   _other_regions.scrub(ctbs, region_bm, card_bm);
 920 }
 921 
 922 // Code roots support
 923 
 924 void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
 925   assert(nm != NULL, "sanity");
 926   _code_roots.add(nm);
 927 }
 928 
 929 void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
 930   assert(nm != NULL, "sanity");
 931   _code_roots.remove(nm);
 932   // Check that there were no duplicates
 933   guarantee(!_code_roots.contains(nm), "duplicate entry found");
 934 }
 935 
 936 class NMethodMigrationOopClosure : public OopClosure {
 937   G1CollectedHeap* _g1h;
 938   HeapRegion* _from;
 939   nmethod* _nm;
 940 
 941   uint _num_self_forwarded;
 942 
 943   template <class T> void do_oop_work(T* p) {
 944     T heap_oop = oopDesc::load_heap_oop(p);
 945     if (!oopDesc::is_null(heap_oop)) {
 946       oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 947       if (_from->is_in(obj)) {
 948         // Reference still points into the source region.
 949         // Since roots are immediately evacuated this means that
 950         // we must have self forwarded the object
 951         assert(obj->is_forwarded(),
 952                err_msg("code roots should be immediately evacuated. "
 953                        "Ref: "PTR_FORMAT", "
 954                        "Obj: "PTR_FORMAT", "
 955                        "Region: "HR_FORMAT,
 956                        p, (void*) obj, HR_FORMAT_PARAMS(_from)));
 957         assert(obj->forwardee() == obj,
 958                err_msg("not self forwarded? obj = "PTR_FORMAT, (void*)obj));
 959 
 960         // The object has been self forwarded.
 961         // Note, if we're during an initial mark pause, there is
 962         // no need to explicitly mark object. It will be marked
 963         // during the regular evacuation failure handling code.
 964         _num_self_forwarded++;
 965       } else {
 966         // The reference points into a promotion or to-space region
 967         HeapRegion* to = _g1h->heap_region_containing(obj);
 968         to->rem_set()->add_strong_code_root(_nm);
 969       }
 970     }
 971   }
 972 
 973 public:
 974   NMethodMigrationOopClosure(G1CollectedHeap* g1h, HeapRegion* from, nmethod* nm):
 975     _g1h(g1h), _from(from), _nm(nm), _num_self_forwarded(0) {}
 976 
 977   void do_oop(narrowOop* p) { do_oop_work(p); }
 978   void do_oop(oop* p)       { do_oop_work(p); }
 979 
 980   uint retain() { return _num_self_forwarded > 0; }
 981 };
 982 
 983 void HeapRegionRemSet::migrate_strong_code_roots() {
 984   assert(hr()->in_collection_set(), "only collection set regions");
 985   assert(!hr()->isHumongous(),
 986          err_msg("humongous region "HR_FORMAT" should not have been added to the collection set",
 987                  HR_FORMAT_PARAMS(hr())));
 988 
 989   ResourceMark rm;
 990 
 991   // List of code blobs to retain for this region
 992   GrowableArray<nmethod*> to_be_retained(10);
 993   G1CollectedHeap* g1h = G1CollectedHeap::heap();
 994 
 995   while (!_code_roots.is_empty()) {
 996     nmethod *nm = _code_roots.pop();
 997     if (nm != NULL) {
 998       NMethodMigrationOopClosure oop_cl(g1h, hr(), nm);
 999       nm->oops_do(&oop_cl);
1000       if (oop_cl.retain()) {
1001         to_be_retained.push(nm);
1002       }
1003     }
1004   }
1005 
1006   // Now push any code roots we need to retain
1007   assert(to_be_retained.is_empty() || hr()->evacuation_failed(),
1008          "Retained nmethod list must be empty or "
1009          "evacuation of this region failed");
1010 
1011   while (to_be_retained.is_nonempty()) {
1012     nmethod* nm = to_be_retained.pop();
1013     assert(nm != NULL, "sanity");
1014     add_strong_code_root(nm);
1015   }
1016 }
1017 
1018 void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
1019   _code_roots.nmethods_do(blk);
1020 }
1021 
1022 size_t HeapRegionRemSet::strong_code_roots_mem_size() {
1023   return _code_roots.mem_size();
1024 }
1025 
1026 HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) :
1027   _hrrs(hrrs),
1028   _g1h(G1CollectedHeap::heap()),
1029   _coarse_map(&hrrs->_other_regions._coarse_map),
1030   _bosa(hrrs->bosa()),
1031   _is(Sparse),
1032   // Set these values so that we increment to the first region.
1033   _coarse_cur_region_index(-1),
1034   _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1),
1035   _cur_card_in_prt(HeapRegion::CardsPerRegion),
1036   _fine_cur_prt(NULL),
1037   _n_yielded_coarse(0),
1038   _n_yielded_fine(0),
1039   _n_yielded_sparse(0),
1040   _sparse_iter(&hrrs->_other_regions._sparse_table) {}
1041 
1042 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) {
1043   if (_hrrs->_other_regions._n_coarse_entries == 0) return false;
1044   // Go to the next card.
1045   _coarse_cur_region_cur_card++;
1046   // Was the last the last card in the current region?
1047   if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) {
1048     // Yes: find the next region.  This may leave _coarse_cur_region_index
1049     // Set to the last index, in which case there are no more coarse
1050     // regions.
1051     _coarse_cur_region_index =
1052       (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1);
1053     if ((size_t)_coarse_cur_region_index < _coarse_map->size()) {
1054       _coarse_cur_region_cur_card = 0;
1055       HeapWord* r_bot =
1056         _g1h->region_at((uint) _coarse_cur_region_index)->bottom();
1057       _cur_region_card_offset = _bosa->index_for(r_bot);
1058     } else {
1059       return false;
1060     }
1061   }
1062   // If we didn't return false above, then we can yield a card.
1063   card_index = _cur_region_card_offset + _coarse_cur_region_cur_card;
1064   return true;
1065 }
1066 
1067 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) {
1068   if (fine_has_next()) {
1069     _cur_card_in_prt =
1070       _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
1071   }
1072   if (_cur_card_in_prt == HeapRegion::CardsPerRegion) {
1073     // _fine_cur_prt may still be NULL in case if there are not PRTs at all for
1074     // the remembered set.
1075     if (_fine_cur_prt == NULL || _fine_cur_prt->next() == NULL) {
1076       return false;
1077     }
1078     PerRegionTable* next_prt = _fine_cur_prt->next();
1079     switch_to_prt(next_prt);
1080     _cur_card_in_prt = _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
1081   }
1082 
1083   card_index = _cur_region_card_offset + _cur_card_in_prt;
1084   guarantee(_cur_card_in_prt < HeapRegion::CardsPerRegion,
1085             err_msg("Card index "SIZE_FORMAT" must be within the region", _cur_card_in_prt));
1086   return true;
1087 }
1088 
1089 bool HeapRegionRemSetIterator::fine_has_next() {
1090   return _cur_card_in_prt != HeapRegion::CardsPerRegion;
1091 }
1092 
1093 void HeapRegionRemSetIterator::switch_to_prt(PerRegionTable* prt) {
1094   assert(prt != NULL, "Cannot switch to NULL prt");
1095   _fine_cur_prt = prt;
1096 
1097   HeapWord* r_bot = _fine_cur_prt->hr()->bottom();
1098   _cur_region_card_offset = _bosa->index_for(r_bot);
1099 
1100   // The bitmap scan for the PRT always scans from _cur_region_cur_card + 1.
1101   // To avoid special-casing this start case, and not miss the first bitmap
1102   // entry, initialize _cur_region_cur_card with -1 instead of 0.
1103   _cur_card_in_prt = (size_t)-1;
1104 }
1105 
1106 bool HeapRegionRemSetIterator::has_next(size_t& card_index) {
1107   switch (_is) {
1108   case Sparse: {
1109     if (_sparse_iter.has_next(card_index)) {
1110       _n_yielded_sparse++;
1111       return true;
1112     }
1113     // Otherwise, deliberate fall-through
1114     _is = Fine;
1115     PerRegionTable* initial_fine_prt = _hrrs->_other_regions._first_all_fine_prts;
1116     if (initial_fine_prt != NULL) {
1117       switch_to_prt(_hrrs->_other_regions._first_all_fine_prts);
1118     }
1119   }
1120   case Fine:
1121     if (fine_has_next(card_index)) {
1122       _n_yielded_fine++;
1123       return true;
1124     }
1125     // Otherwise, deliberate fall-through
1126     _is = Coarse;
1127   case Coarse:
1128     if (coarse_has_next(card_index)) {
1129       _n_yielded_coarse++;
1130       return true;
1131     }
1132     // Otherwise...
1133     break;
1134   }
1135   assert(ParallelGCThreads > 1 ||
1136          n_yielded() == _hrrs->occupied(),
1137          "Should have yielded all the cards in the rem set "
1138          "(in the non-par case).");
1139   return false;
1140 }
1141 
1142 
1143 
1144 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL;
1145 HeapWord**          HeapRegionRemSet::_recorded_cards = NULL;
1146 HeapRegion**        HeapRegionRemSet::_recorded_regions = NULL;
1147 int                 HeapRegionRemSet::_n_recorded = 0;
1148 
1149 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL;
1150 int*         HeapRegionRemSet::_recorded_event_index = NULL;
1151 int          HeapRegionRemSet::_n_recorded_events = 0;
1152 
1153 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) {
1154   if (_recorded_oops == NULL) {
1155     assert(_n_recorded == 0
1156            && _recorded_cards == NULL
1157            && _recorded_regions == NULL,
1158            "Inv");
1159     _recorded_oops    = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded, mtGC);
1160     _recorded_cards   = NEW_C_HEAP_ARRAY(HeapWord*,          MaxRecorded, mtGC);
1161     _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*,        MaxRecorded, mtGC);
1162   }
1163   if (_n_recorded == MaxRecorded) {
1164     gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded);
1165   } else {
1166     _recorded_cards[_n_recorded] =
1167       (HeapWord*)align_size_down(uintptr_t(f),
1168                                  CardTableModRefBS::card_size);
1169     _recorded_oops[_n_recorded] = f;
1170     _recorded_regions[_n_recorded] = hr;
1171     _n_recorded++;
1172   }
1173 }
1174 
1175 void HeapRegionRemSet::record_event(Event evnt) {
1176   if (!G1RecordHRRSEvents) return;
1177 
1178   if (_recorded_events == NULL) {
1179     assert(_n_recorded_events == 0
1180            && _recorded_event_index == NULL,
1181            "Inv");
1182     _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents, mtGC);
1183     _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents, mtGC);
1184   }
1185   if (_n_recorded_events == MaxRecordedEvents) {
1186     gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents);
1187   } else {
1188     _recorded_events[_n_recorded_events] = evnt;
1189     _recorded_event_index[_n_recorded_events] = _n_recorded;
1190     _n_recorded_events++;
1191   }
1192 }
1193 
1194 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) {
1195   switch (evnt) {
1196   case Event_EvacStart:
1197     str->print("Evac Start");
1198     break;
1199   case Event_EvacEnd:
1200     str->print("Evac End");
1201     break;
1202   case Event_RSUpdateEnd:
1203     str->print("RS Update End");
1204     break;
1205   }
1206 }
1207 
1208 void HeapRegionRemSet::print_recorded() {
1209   int cur_evnt = 0;
1210   Event cur_evnt_kind;
1211   int cur_evnt_ind = 0;
1212   if (_n_recorded_events > 0) {
1213     cur_evnt_kind = _recorded_events[cur_evnt];
1214     cur_evnt_ind = _recorded_event_index[cur_evnt];
1215   }
1216 
1217   for (int i = 0; i < _n_recorded; i++) {
1218     while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) {
1219       gclog_or_tty->print("Event: ");
1220       print_event(gclog_or_tty, cur_evnt_kind);
1221       gclog_or_tty->cr();
1222       cur_evnt++;
1223       if (cur_evnt < MaxRecordedEvents) {
1224         cur_evnt_kind = _recorded_events[cur_evnt];
1225         cur_evnt_ind = _recorded_event_index[cur_evnt];
1226       }
1227     }
1228     gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]"
1229                         " for ref " PTR_FORMAT ".\n",
1230                         _recorded_cards[i], _recorded_regions[i]->bottom(),
1231                         _recorded_oops[i]);
1232   }
1233 }
1234 
1235 void HeapRegionRemSet::reset_for_cleanup_tasks() {
1236   SparsePRT::reset_for_cleanup_tasks();
1237 }
1238 
1239 void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
1240   _other_regions.do_cleanup_work(hrrs_cleanup_task);
1241 }
1242 
1243 void
1244 HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) {
1245   SparsePRT::finish_cleanup_task(hrrs_cleanup_task);
1246 }
1247 
1248 #ifndef PRODUCT
1249 void PerRegionTable::test_fl_mem_size() {
1250   PerRegionTable* dummy = alloc(NULL);
1251 
1252   size_t min_prt_size = sizeof(void*) + dummy->bm()->size_in_words() * HeapWordSize;
1253   assert(dummy->mem_size() > min_prt_size,
1254          err_msg("PerRegionTable memory usage is suspiciously small, only has "SIZE_FORMAT" bytes. "
1255                  "Should be at least "SIZE_FORMAT" bytes.", dummy->mem_size(), min_prt_size));
1256   free(dummy);
1257   guarantee(dummy->mem_size() == fl_mem_size(), "fl_mem_size() does not return the correct element size");
1258   // try to reset the state
1259   _free_list = NULL;
1260   delete dummy;
1261 }
1262 
1263 void HeapRegionRemSet::test_prt() {
1264   PerRegionTable::test_fl_mem_size();
1265 }
1266 
1267 void HeapRegionRemSet::test() {
1268   os::sleep(Thread::current(), (jlong)5000, false);
1269   G1CollectedHeap* g1h = G1CollectedHeap::heap();
1270 
1271   // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same
1272   // hash bucket.
1273   HeapRegion* hr0 = g1h->region_at(0);
1274   HeapRegion* hr1 = g1h->region_at(1);
1275   HeapRegion* hr2 = g1h->region_at(5);
1276   HeapRegion* hr3 = g1h->region_at(6);
1277   HeapRegion* hr4 = g1h->region_at(7);
1278   HeapRegion* hr5 = g1h->region_at(8);
1279 
1280   HeapWord* hr1_start = hr1->bottom();
1281   HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2;
1282   HeapWord* hr1_last = hr1->end() - 1;
1283 
1284   HeapWord* hr2_start = hr2->bottom();
1285   HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2;
1286   HeapWord* hr2_last = hr2->end() - 1;
1287 
1288   HeapWord* hr3_start = hr3->bottom();
1289   HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2;
1290   HeapWord* hr3_last = hr3->end() - 1;
1291 
1292   HeapRegionRemSet* hrrs = hr0->rem_set();
1293 
1294   // Make three references from region 0x101...
1295   hrrs->add_reference((OopOrNarrowOopStar)hr1_start);
1296   hrrs->add_reference((OopOrNarrowOopStar)hr1_mid);
1297   hrrs->add_reference((OopOrNarrowOopStar)hr1_last);
1298 
1299   hrrs->add_reference((OopOrNarrowOopStar)hr2_start);
1300   hrrs->add_reference((OopOrNarrowOopStar)hr2_mid);
1301   hrrs->add_reference((OopOrNarrowOopStar)hr2_last);
1302 
1303   hrrs->add_reference((OopOrNarrowOopStar)hr3_start);
1304   hrrs->add_reference((OopOrNarrowOopStar)hr3_mid);
1305   hrrs->add_reference((OopOrNarrowOopStar)hr3_last);
1306 
1307   // Now cause a coarsening.
1308   hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom());
1309   hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom());
1310 
1311   // Now, does iteration yield these three?
1312   HeapRegionRemSetIterator iter(hrrs);
1313   size_t sum = 0;
1314   size_t card_index;
1315   while (iter.has_next(card_index)) {
1316     HeapWord* card_start =
1317       G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
1318     gclog_or_tty->print_cr("  Card " PTR_FORMAT ".", card_start);
1319     sum++;
1320   }
1321   guarantee(sum == 11 - 3 + 2048, "Failure");
1322   guarantee(sum == hrrs->occupied(), "Failure");
1323 }
1324 #endif
--- EOF ---