1 /*
   2  * Copyright (c) 2001, 2013, 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/space.inline.hpp"
  33 #include "oops/oop.inline.hpp"
  34 #include "utilities/bitMap.inline.hpp"
  35 #include "utilities/globalDefinitions.hpp"
  36 #include "utilities/growableArray.hpp"
  37 
  38 class PerRegionTable: public CHeapObj<mtGC> {
  39   friend class OtherRegionsTable;
  40   friend class HeapRegionRemSetIterator;
  41 
  42   HeapRegion*     _hr;
  43   BitMap          _bm;
  44   jint            _occupied;
  45 
  46   // next pointer for free/allocated 'all' list
  47   PerRegionTable* _next;
  48 
  49   // prev pointer for the allocated 'all' list
  50   PerRegionTable* _prev;
  51 
  52   // next pointer in collision list
  53   PerRegionTable * _collision_list_next;
  54 
  55   // Global free list of PRTs
  56   static PerRegionTable* _free_list;
  57 
  58 protected:
  59   // We need access in order to union things into the base table.
  60   BitMap* bm() { return &_bm; }
  61 
  62   void recount_occupied() {
  63     _occupied = (jint) bm()->count_one_bits();
  64   }
  65 
  66   PerRegionTable(HeapRegion* hr) :
  67     _hr(hr),
  68     _occupied(0),
  69     _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */),
  70     _collision_list_next(NULL), _next(NULL), _prev(NULL)
  71   {}
  72 
  73   void add_card_work(CardIdx_t from_card, bool par) {
  74     if (!_bm.at(from_card)) {
  75       if (par) {
  76         if (_bm.par_at_put(from_card, 1)) {
  77           Atomic::inc(&_occupied);
  78         }
  79       } else {
  80         _bm.at_put(from_card, 1);
  81         _occupied++;
  82       }
  83     }
  84   }
  85 
  86   void add_reference_work(OopOrNarrowOopStar from, bool par) {
  87     // Must make this robust in case "from" is not in "_hr", because of
  88     // concurrency.
  89 
  90     if (G1TraceHeapRegionRememberedSet) {
  91       gclog_or_tty->print_cr("    PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").",
  92                              from,
  93                              UseCompressedOops
  94                              ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
  95                              : (void *)oopDesc::load_decode_heap_oop((oop*)from));
  96     }
  97 
  98     HeapRegion* loc_hr = hr();
  99     // If the test below fails, then this table was reused concurrently
 100     // with this operation.  This is OK, since the old table was coarsened,
 101     // and adding a bit to the new table is never incorrect.
 102     // If the table used to belong to a continues humongous region and is
 103     // now reused for the corresponding start humongous region, we need to
 104     // make sure that we detect this. Thus, we call is_in_reserved_raw()
 105     // instead of just is_in_reserved() here.
 106     if (loc_hr->is_in_reserved_raw(from)) {
 107       size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom());
 108       CardIdx_t from_card = (CardIdx_t)
 109           hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize);
 110 
 111       assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion,
 112              "Must be in range.");
 113       add_card_work(from_card, par);
 114     }
 115   }
 116 
 117 public:
 118 
 119   HeapRegion* hr() const { return _hr; }
 120 
 121   jint occupied() const {
 122     // Overkill, but if we ever need it...
 123     // guarantee(_occupied == _bm.count_one_bits(), "Check");
 124     return _occupied;
 125   }
 126 
 127   void init(HeapRegion* hr, bool clear_links_to_all_list) {
 128     if (clear_links_to_all_list) {
 129       set_next(NULL);
 130       set_prev(NULL);
 131     }
 132     _hr = hr;
 133     _collision_list_next = NULL;
 134     _occupied = 0;
 135     _bm.clear();
 136   }
 137 
 138   void add_reference(OopOrNarrowOopStar from) {
 139     add_reference_work(from, /*parallel*/ true);
 140   }
 141 
 142   void seq_add_reference(OopOrNarrowOopStar from) {
 143     add_reference_work(from, /*parallel*/ false);
 144   }
 145 
 146   void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) {
 147     HeapWord* hr_bot = hr()->bottom();
 148     size_t hr_first_card_index = ctbs->index_for(hr_bot);
 149     bm()->set_intersection_at_offset(*card_bm, hr_first_card_index);
 150     recount_occupied();
 151   }
 152 
 153   void add_card(CardIdx_t from_card_index) {
 154     add_card_work(from_card_index, /*parallel*/ true);
 155   }
 156 
 157   void seq_add_card(CardIdx_t from_card_index) {
 158     add_card_work(from_card_index, /*parallel*/ false);
 159   }
 160 
 161   // (Destructively) union the bitmap of the current table into the given
 162   // bitmap (which is assumed to be of the same size.)
 163   void union_bitmap_into(BitMap* bm) {
 164     bm->set_union(_bm);
 165   }
 166 
 167   // Mem size in bytes.
 168   size_t mem_size() const {
 169     return sizeof(this) + _bm.size_in_words() * HeapWordSize;
 170   }
 171 
 172   // Requires "from" to be in "hr()".
 173   bool contains_reference(OopOrNarrowOopStar from) const {
 174     assert(hr()->is_in_reserved(from), "Precondition.");
 175     size_t card_ind = pointer_delta(from, hr()->bottom(),
 176                                     CardTableModRefBS::card_size);
 177     return _bm.at(card_ind);
 178   }
 179 
 180   // Bulk-free the PRTs from prt to last, assumes that they are
 181   // linked together using their _next field.
 182   static void bulk_free(PerRegionTable* prt, PerRegionTable* last) {
 183     while (true) {
 184       PerRegionTable* fl = _free_list;
 185       last->set_next(fl);
 186       PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl);
 187       if (res == fl) {
 188         return;
 189       }
 190     }
 191     ShouldNotReachHere();
 192   }
 193 
 194   static void free(PerRegionTable* prt) {
 195     bulk_free(prt, prt);
 196   }
 197 
 198   // Returns an initialized PerRegionTable instance.
 199   static PerRegionTable* alloc(HeapRegion* hr) {
 200     PerRegionTable* fl = _free_list;
 201     while (fl != NULL) {
 202       PerRegionTable* nxt = fl->next();
 203       PerRegionTable* res =
 204         (PerRegionTable*)
 205         Atomic::cmpxchg_ptr(nxt, &_free_list, fl);
 206       if (res == fl) {
 207         fl->init(hr, true);
 208         return fl;
 209       } else {
 210         fl = _free_list;
 211       }
 212     }
 213     assert(fl == NULL, "Loop condition.");
 214     return new PerRegionTable(hr);
 215   }
 216 
 217   PerRegionTable* next() const { return _next; }
 218   void set_next(PerRegionTable* next) { _next = next; }
 219   PerRegionTable* prev() const { return _prev; }
 220   void set_prev(PerRegionTable* prev) { _prev = prev; }
 221 
 222   // Accessor and Modification routines for the pointer for the
 223   // singly linked collision list that links the PRTs within the
 224   // OtherRegionsTable::_fine_grain_regions hash table.
 225   //
 226   // It might be useful to also make the collision list doubly linked
 227   // to avoid iteration over the collisions list during scrubbing/deletion.
 228   // OTOH there might not be many collisions.
 229 
 230   PerRegionTable* collision_list_next() const {
 231     return _collision_list_next;
 232   }
 233 
 234   void set_collision_list_next(PerRegionTable* next) {
 235     _collision_list_next = next;
 236   }
 237 
 238   PerRegionTable** collision_list_next_addr() {
 239     return &_collision_list_next;
 240   }
 241 
 242   static size_t fl_mem_size() {
 243     PerRegionTable* cur = _free_list;
 244     size_t res = 0;
 245     while (cur != NULL) {
 246       res += cur->mem_size();
 247       cur = cur->next();
 248     }
 249     return res;
 250   }
 251 
 252   static void test_fl_mem_size();
 253 };
 254 
 255 PerRegionTable* PerRegionTable::_free_list = NULL;
 256 
 257 size_t OtherRegionsTable::_max_fine_entries = 0;
 258 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
 259 size_t OtherRegionsTable::_fine_eviction_stride = 0;
 260 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
 261 
 262 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr) :
 263   _g1h(G1CollectedHeap::heap()),
 264   _m(Mutex::leaf, "An OtherRegionsTable lock", true),
 265   _hr(hr),
 266   _coarse_map(G1CollectedHeap::heap()->max_regions(),
 267               false /* in-resource-area */),
 268   _fine_grain_regions(NULL),
 269   _first_all_fine_prts(NULL), _last_all_fine_prts(NULL),
 270   _n_fine_entries(0), _n_coarse_entries(0),
 271   _fine_eviction_start(0),
 272   _sparse_table(hr)
 273 {
 274   typedef PerRegionTable* PerRegionTablePtr;
 275 
 276   if (_max_fine_entries == 0) {
 277     assert(_mod_max_fine_entries_mask == 0, "Both or none.");
 278     size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
 279     _max_fine_entries = (size_t)1 << max_entries_log;
 280     _mod_max_fine_entries_mask = _max_fine_entries - 1;
 281 
 282     assert(_fine_eviction_sample_size == 0
 283            && _fine_eviction_stride == 0, "All init at same time.");
 284     _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
 285     _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
 286   }
 287 
 288   _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries,
 289                         mtGC, 0, AllocFailStrategy::RETURN_NULL);
 290 
 291   if (_fine_grain_regions == NULL) {
 292     vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR,
 293                           "Failed to allocate _fine_grain_entries.");
 294   }
 295 
 296   for (size_t i = 0; i < _max_fine_entries; i++) {
 297     _fine_grain_regions[i] = NULL;
 298   }
 299 }
 300 
 301 void OtherRegionsTable::link_to_all(PerRegionTable* prt) {
 302   // We always append to the beginning of the list for convenience;
 303   // the order of entries in this list does not matter.
 304   if (_first_all_fine_prts != NULL) {
 305     assert(_first_all_fine_prts->prev() == NULL, "invariant");
 306     _first_all_fine_prts->set_prev(prt);
 307     prt->set_next(_first_all_fine_prts);
 308   } else {
 309     // this is the first element we insert. Adjust the "last" pointer
 310     _last_all_fine_prts = prt;
 311     assert(prt->next() == NULL, "just checking");
 312   }
 313   // the new element is always the first element without a predecessor
 314   prt->set_prev(NULL);
 315   _first_all_fine_prts = prt;
 316 
 317   assert(prt->prev() == NULL, "just checking");
 318   assert(_first_all_fine_prts == prt, "just checking");
 319   assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
 320          (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
 321          "just checking");
 322   assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
 323          "just checking");
 324   assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
 325          "just checking");
 326 }
 327 
 328 void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) {
 329   if (prt->prev() != NULL) {
 330     assert(_first_all_fine_prts != prt, "just checking");
 331     prt->prev()->set_next(prt->next());
 332     // removing the last element in the list?
 333     if (_last_all_fine_prts == prt) {
 334       _last_all_fine_prts = prt->prev();
 335     }
 336   } else {
 337     assert(_first_all_fine_prts == prt, "just checking");
 338     _first_all_fine_prts = prt->next();
 339     // list is empty now?
 340     if (_first_all_fine_prts == NULL) {
 341       _last_all_fine_prts = NULL;
 342     }
 343   }
 344 
 345   if (prt->next() != NULL) {
 346     prt->next()->set_prev(prt->prev());
 347   }
 348 
 349   prt->set_next(NULL);
 350   prt->set_prev(NULL);
 351 
 352   assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
 353          (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
 354          "just checking");
 355   assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
 356          "just checking");
 357   assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
 358          "just checking");
 359 }
 360 
 361 int**  OtherRegionsTable::_from_card_cache = NULL;
 362 size_t OtherRegionsTable::_from_card_cache_max_regions = 0;
 363 size_t OtherRegionsTable::_from_card_cache_mem_size = 0;
 364 
 365 void OtherRegionsTable::init_from_card_cache(size_t max_regions) {
 366   _from_card_cache_max_regions = max_regions;
 367 
 368   int n_par_rs = HeapRegionRemSet::num_par_rem_sets();
 369   _from_card_cache = NEW_C_HEAP_ARRAY(int*, n_par_rs, mtGC);
 370   for (int i = 0; i < n_par_rs; i++) {
 371     _from_card_cache[i] = NEW_C_HEAP_ARRAY(int, max_regions, mtGC);
 372     for (size_t j = 0; j < max_regions; j++) {
 373       _from_card_cache[i][j] = -1;  // An invalid value.
 374     }
 375   }
 376   _from_card_cache_mem_size = n_par_rs * max_regions * sizeof(int);
 377 }
 378 
 379 void OtherRegionsTable::shrink_from_card_cache(size_t new_n_regs) {
 380   for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
 381     assert(new_n_regs <= _from_card_cache_max_regions, "Must be within max.");
 382     for (size_t j = new_n_regs; j < _from_card_cache_max_regions; j++) {
 383       _from_card_cache[i][j] = -1;  // An invalid value.
 384     }
 385   }
 386 }
 387 
 388 #ifndef PRODUCT
 389 void OtherRegionsTable::print_from_card_cache() {
 390   for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
 391     for (size_t j = 0; j < _from_card_cache_max_regions; j++) {
 392       gclog_or_tty->print_cr("_from_card_cache[%d][%d] = %d.",
 393                     i, j, _from_card_cache[i][j]);
 394     }
 395   }
 396 }
 397 #endif
 398 
 399 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, int tid) {
 400   size_t cur_hrs_ind = (size_t) hr()->hrs_index();
 401 
 402   if (G1TraceHeapRegionRememberedSet) {
 403     gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").",
 404                                                     from,
 405                                                     UseCompressedOops
 406                                                     ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
 407                                                     : (void *)oopDesc::load_decode_heap_oop((oop*)from));
 408   }
 409 
 410   int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift);
 411 
 412   if (G1TraceHeapRegionRememberedSet) {
 413     gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)",
 414                   hr()->bottom(), from_card,
 415                   _from_card_cache[tid][cur_hrs_ind]);
 416   }
 417 
 418   if (from_card == _from_card_cache[tid][cur_hrs_ind]) {
 419     if (G1TraceHeapRegionRememberedSet) {
 420       gclog_or_tty->print_cr("  from-card cache hit.");
 421     }
 422     assert(contains_reference(from), "We just added it!");
 423     return;
 424   } else {
 425     _from_card_cache[tid][cur_hrs_ind] = from_card;
 426   }
 427 
 428   // Note that this may be a continued H region.
 429   HeapRegion* from_hr = _g1h->heap_region_containing_raw(from);
 430   RegionIdx_t from_hrs_ind = (RegionIdx_t) from_hr->hrs_index();
 431 
 432   // If the region is already coarsened, return.
 433   if (_coarse_map.at(from_hrs_ind)) {
 434     if (G1TraceHeapRegionRememberedSet) {
 435       gclog_or_tty->print_cr("  coarse map hit.");
 436     }
 437     assert(contains_reference(from), "We just added it!");
 438     return;
 439   }
 440 
 441   // Otherwise find a per-region table to add it to.
 442   size_t ind = from_hrs_ind & _mod_max_fine_entries_mask;
 443   PerRegionTable* prt = find_region_table(ind, from_hr);
 444   if (prt == NULL) {
 445     MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
 446     // Confirm that it's really not there...
 447     prt = find_region_table(ind, from_hr);
 448     if (prt == NULL) {
 449 
 450       uintptr_t from_hr_bot_card_index =
 451         uintptr_t(from_hr->bottom())
 452           >> CardTableModRefBS::card_shift;
 453       CardIdx_t card_index = from_card - from_hr_bot_card_index;
 454       assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
 455              "Must be in range.");
 456       if (G1HRRSUseSparseTable &&
 457           _sparse_table.add_card(from_hrs_ind, card_index)) {
 458         if (G1RecordHRRSOops) {
 459           HeapRegionRemSet::record(hr(), from);
 460           if (G1TraceHeapRegionRememberedSet) {
 461             gclog_or_tty->print("   Added card " PTR_FORMAT " to region "
 462                                 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
 463                                 align_size_down(uintptr_t(from),
 464                                                 CardTableModRefBS::card_size),
 465                                 hr()->bottom(), from);
 466           }
 467         }
 468         if (G1TraceHeapRegionRememberedSet) {
 469           gclog_or_tty->print_cr("   added card to sparse table.");
 470         }
 471         assert(contains_reference_locked(from), "We just added it!");
 472         return;
 473       } else {
 474         if (G1TraceHeapRegionRememberedSet) {
 475           gclog_or_tty->print_cr("   [tid %d] sparse table entry "
 476                         "overflow(f: %d, t: %d)",
 477                         tid, from_hrs_ind, cur_hrs_ind);
 478         }
 479       }
 480 
 481       if (_n_fine_entries == _max_fine_entries) {
 482         prt = delete_region_table();
 483         // There is no need to clear the links to the 'all' list here:
 484         // prt will be reused immediately, i.e. remain in the 'all' list.
 485         prt->init(from_hr, false /* clear_links_to_all_list */);
 486       } else {
 487         prt = PerRegionTable::alloc(from_hr);
 488         link_to_all(prt);
 489       }
 490 
 491       PerRegionTable* first_prt = _fine_grain_regions[ind];
 492       prt->set_collision_list_next(first_prt);
 493       _fine_grain_regions[ind] = prt;
 494       _n_fine_entries++;
 495 
 496       if (G1HRRSUseSparseTable) {
 497         // Transfer from sparse to fine-grain.
 498         SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrs_ind);
 499         assert(sprt_entry != NULL, "There should have been an entry");
 500         for (int i = 0; i < SparsePRTEntry::cards_num(); i++) {
 501           CardIdx_t c = sprt_entry->card(i);
 502           if (c != SparsePRTEntry::NullEntry) {
 503             prt->add_card(c);
 504           }
 505         }
 506         // Now we can delete the sparse entry.
 507         bool res = _sparse_table.delete_entry(from_hrs_ind);
 508         assert(res, "It should have been there.");
 509       }
 510     }
 511     assert(prt != NULL && prt->hr() == from_hr, "consequence");
 512   }
 513   // Note that we can't assert "prt->hr() == from_hr", because of the
 514   // possibility of concurrent reuse.  But see head comment of
 515   // OtherRegionsTable for why this is OK.
 516   assert(prt != NULL, "Inv");
 517 
 518   prt->add_reference(from);
 519 
 520   if (G1RecordHRRSOops) {
 521     HeapRegionRemSet::record(hr(), from);
 522     if (G1TraceHeapRegionRememberedSet) {
 523       gclog_or_tty->print("Added card " PTR_FORMAT " to region "
 524                           "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
 525                           align_size_down(uintptr_t(from),
 526                                           CardTableModRefBS::card_size),
 527                           hr()->bottom(), from);
 528     }
 529   }
 530   assert(contains_reference(from), "We just added it!");
 531 }
 532 
 533 PerRegionTable*
 534 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const {
 535   assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
 536   PerRegionTable* prt = _fine_grain_regions[ind];
 537   while (prt != NULL && prt->hr() != hr) {
 538     prt = prt->collision_list_next();
 539   }
 540   // Loop postcondition is the method postcondition.
 541   return prt;
 542 }
 543 
 544 jint OtherRegionsTable::_n_coarsenings = 0;
 545 
 546 PerRegionTable* OtherRegionsTable::delete_region_table() {
 547   assert(_m.owned_by_self(), "Precondition");
 548   assert(_n_fine_entries == _max_fine_entries, "Precondition");
 549   PerRegionTable* max = NULL;
 550   jint max_occ = 0;
 551   PerRegionTable** max_prev;
 552   size_t max_ind;
 553 
 554   size_t i = _fine_eviction_start;
 555   for (size_t k = 0; k < _fine_eviction_sample_size; k++) {
 556     size_t ii = i;
 557     // Make sure we get a non-NULL sample.
 558     while (_fine_grain_regions[ii] == NULL) {
 559       ii++;
 560       if (ii == _max_fine_entries) ii = 0;
 561       guarantee(ii != i, "We must find one.");
 562     }
 563     PerRegionTable** prev = &_fine_grain_regions[ii];
 564     PerRegionTable* cur = *prev;
 565     while (cur != NULL) {
 566       jint cur_occ = cur->occupied();
 567       if (max == NULL || cur_occ > max_occ) {
 568         max = cur;
 569         max_prev = prev;
 570         max_ind = i;
 571         max_occ = cur_occ;
 572       }
 573       prev = cur->collision_list_next_addr();
 574       cur = cur->collision_list_next();
 575     }
 576     i = i + _fine_eviction_stride;
 577     if (i >= _n_fine_entries) i = i - _n_fine_entries;
 578   }
 579 
 580   _fine_eviction_start++;
 581 
 582   if (_fine_eviction_start >= _n_fine_entries) {
 583     _fine_eviction_start -= _n_fine_entries;
 584   }
 585 
 586   guarantee(max != NULL, "Since _n_fine_entries > 0");
 587 
 588   // Set the corresponding coarse bit.
 589   size_t max_hrs_index = (size_t) max->hr()->hrs_index();
 590   if (!_coarse_map.at(max_hrs_index)) {
 591     _coarse_map.at_put(max_hrs_index, true);
 592     _n_coarse_entries++;
 593     if (G1TraceHeapRegionRememberedSet) {
 594       gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] "
 595                  "for region [" PTR_FORMAT "...] (%d coarse entries).\n",
 596                  hr()->bottom(),
 597                  max->hr()->bottom(),
 598                  _n_coarse_entries);
 599     }
 600   }
 601 
 602   // Unsplice.
 603   *max_prev = max->collision_list_next();
 604   Atomic::inc(&_n_coarsenings);
 605   _n_fine_entries--;
 606   return max;
 607 }
 608 
 609 
 610 // At present, this must be called stop-world single-threaded.
 611 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs,
 612                               BitMap* region_bm, BitMap* card_bm) {
 613   // First eliminated garbage regions from the coarse map.
 614   if (G1RSScrubVerbose) {
 615     gclog_or_tty->print_cr("Scrubbing region %u:", hr()->hrs_index());
 616   }
 617 
 618   assert(_coarse_map.size() == region_bm->size(), "Precondition");
 619   if (G1RSScrubVerbose) {
 620     gclog_or_tty->print("   Coarse map: before = "SIZE_FORMAT"...",
 621                         _n_coarse_entries);
 622   }
 623   _coarse_map.set_intersection(*region_bm);
 624   _n_coarse_entries = _coarse_map.count_one_bits();
 625   if (G1RSScrubVerbose) {
 626     gclog_or_tty->print_cr("   after = "SIZE_FORMAT".", _n_coarse_entries);
 627   }
 628 
 629   // Now do the fine-grained maps.
 630   for (size_t i = 0; i < _max_fine_entries; i++) {
 631     PerRegionTable* cur = _fine_grain_regions[i];
 632     PerRegionTable** prev = &_fine_grain_regions[i];
 633     while (cur != NULL) {
 634       PerRegionTable* nxt = cur->collision_list_next();
 635       // If the entire region is dead, eliminate.
 636       if (G1RSScrubVerbose) {
 637         gclog_or_tty->print_cr("     For other region %u:",
 638                                cur->hr()->hrs_index());
 639       }
 640       if (!region_bm->at((size_t) cur->hr()->hrs_index())) {
 641         *prev = nxt;
 642         cur->set_collision_list_next(NULL);
 643         _n_fine_entries--;
 644         if (G1RSScrubVerbose) {
 645           gclog_or_tty->print_cr("          deleted via region map.");
 646         }
 647         unlink_from_all(cur);
 648         PerRegionTable::free(cur);
 649       } else {
 650         // Do fine-grain elimination.
 651         if (G1RSScrubVerbose) {
 652           gclog_or_tty->print("          occ: before = %4d.", cur->occupied());
 653         }
 654         cur->scrub(ctbs, card_bm);
 655         if (G1RSScrubVerbose) {
 656           gclog_or_tty->print_cr("          after = %4d.", cur->occupied());
 657         }
 658         // Did that empty the table completely?
 659         if (cur->occupied() == 0) {
 660           *prev = nxt;
 661           cur->set_collision_list_next(NULL);
 662           _n_fine_entries--;
 663           unlink_from_all(cur);
 664           PerRegionTable::free(cur);
 665         } else {
 666           prev = cur->collision_list_next_addr();
 667         }
 668       }
 669       cur = nxt;
 670     }
 671   }
 672   // Since we may have deleted a from_card_cache entry from the RS, clear
 673   // the FCC.
 674   clear_fcc();
 675 }
 676 
 677 
 678 size_t OtherRegionsTable::occupied() const {
 679   // Cast away const in this case.
 680   MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
 681   size_t sum = occ_fine();
 682   sum += occ_sparse();
 683   sum += occ_coarse();
 684   return sum;
 685 }
 686 
 687 size_t OtherRegionsTable::occ_fine() const {
 688   size_t sum = 0;
 689 
 690   size_t num = 0;
 691   PerRegionTable * cur = _first_all_fine_prts;
 692   while (cur != NULL) {
 693     sum += cur->occupied();
 694     cur = cur->next();
 695     num++;
 696   }
 697   guarantee(num == _n_fine_entries, "just checking");
 698   return sum;
 699 }
 700 
 701 size_t OtherRegionsTable::occ_coarse() const {
 702   return (_n_coarse_entries * HeapRegion::CardsPerRegion);
 703 }
 704 
 705 size_t OtherRegionsTable::occ_sparse() const {
 706   return _sparse_table.occupied();
 707 }
 708 
 709 size_t OtherRegionsTable::mem_size() const {
 710   // Cast away const in this case.
 711   MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
 712   size_t sum = 0;
 713   // all PRTs are of the same size so it is sufficient to query only one of them.
 714   if (_first_all_fine_prts != NULL) {
 715     assert(_last_all_fine_prts != NULL &&
 716       _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant");
 717     sum += _first_all_fine_prts->mem_size() * _n_fine_entries;
 718   }
 719   sum += (sizeof(PerRegionTable*) * _max_fine_entries);
 720   sum += (_coarse_map.size_in_words() * HeapWordSize);
 721   sum += (_sparse_table.mem_size());
 722   sum += sizeof(*this) - sizeof(_sparse_table); // Avoid double counting above.
 723   return sum;
 724 }
 725 
 726 size_t OtherRegionsTable::static_mem_size() {
 727   return _from_card_cache_mem_size;
 728 }
 729 
 730 size_t OtherRegionsTable::fl_mem_size() {
 731   return PerRegionTable::fl_mem_size();
 732 }
 733 
 734 void OtherRegionsTable::clear_fcc() {
 735   size_t hrs_idx = hr()->hrs_index();
 736   for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
 737     _from_card_cache[i][hrs_idx] = -1;
 738   }
 739 }
 740 
 741 void OtherRegionsTable::clear() {
 742   MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
 743   // if there are no entries, skip this step
 744   if (_first_all_fine_prts != NULL) {
 745     guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
 746     PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts);
 747     memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0]));
 748   } else {
 749     guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking");
 750   }
 751 
 752   _first_all_fine_prts = _last_all_fine_prts = NULL;
 753   _sparse_table.clear();
 754   _coarse_map.clear();
 755   _n_fine_entries = 0;
 756   _n_coarse_entries = 0;
 757 
 758   clear_fcc();
 759 }
 760 
 761 void OtherRegionsTable::clear_incoming_entry(HeapRegion* from_hr) {
 762   MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
 763   size_t hrs_ind = (size_t) from_hr->hrs_index();
 764   size_t ind = hrs_ind & _mod_max_fine_entries_mask;
 765   if (del_single_region_table(ind, from_hr)) {
 766     assert(!_coarse_map.at(hrs_ind), "Inv");
 767   } else {
 768     _coarse_map.par_at_put(hrs_ind, 0);
 769   }
 770   // Check to see if any of the fcc entries come from here.
 771   size_t hr_ind = (size_t) hr()->hrs_index();
 772   for (int tid = 0; tid < HeapRegionRemSet::num_par_rem_sets(); tid++) {
 773     int fcc_ent = _from_card_cache[tid][hr_ind];
 774     if (fcc_ent != -1) {
 775       HeapWord* card_addr = (HeapWord*)
 776         (uintptr_t(fcc_ent) << CardTableModRefBS::card_shift);
 777       if (hr()->is_in_reserved(card_addr)) {
 778         // Clear the from card cache.
 779         _from_card_cache[tid][hr_ind] = -1;
 780       }
 781     }
 782   }
 783 }
 784 
 785 bool OtherRegionsTable::del_single_region_table(size_t ind,
 786                                                 HeapRegion* hr) {
 787   assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
 788   PerRegionTable** prev_addr = &_fine_grain_regions[ind];
 789   PerRegionTable* prt = *prev_addr;
 790   while (prt != NULL && prt->hr() != hr) {
 791     prev_addr = prt->collision_list_next_addr();
 792     prt = prt->collision_list_next();
 793   }
 794   if (prt != NULL) {
 795     assert(prt->hr() == hr, "Loop postcondition.");
 796     *prev_addr = prt->collision_list_next();
 797     unlink_from_all(prt);
 798     PerRegionTable::free(prt);
 799     _n_fine_entries--;
 800     return true;
 801   } else {
 802     return false;
 803   }
 804 }
 805 
 806 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
 807   // Cast away const in this case.
 808   MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
 809   return contains_reference_locked(from);
 810 }
 811 
 812 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
 813   HeapRegion* hr = _g1h->heap_region_containing_raw(from);
 814   if (hr == NULL) return false;
 815   RegionIdx_t hr_ind = (RegionIdx_t) hr->hrs_index();
 816   // Is this region in the coarse map?
 817   if (_coarse_map.at(hr_ind)) return true;
 818 
 819   PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
 820                                      hr);
 821   if (prt != NULL) {
 822     return prt->contains_reference(from);
 823 
 824   } else {
 825     uintptr_t from_card =
 826       (uintptr_t(from) >> CardTableModRefBS::card_shift);
 827     uintptr_t hr_bot_card_index =
 828       uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift;
 829     assert(from_card >= hr_bot_card_index, "Inv");
 830     CardIdx_t card_index = from_card - hr_bot_card_index;
 831     assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
 832            "Must be in range.");
 833     return _sparse_table.contains_card(hr_ind, card_index);
 834   }
 835 
 836 
 837 }
 838 
 839 void
 840 OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
 841   _sparse_table.do_cleanup_work(hrrs_cleanup_task);
 842 }
 843 
 844 // Determines how many threads can add records to an rset in parallel.
 845 // This can be done by either mutator threads together with the
 846 // concurrent refinement threads or GC threads.
 847 int HeapRegionRemSet::num_par_rem_sets() {
 848   return (int)MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), ParallelGCThreads);
 849 }
 850 
 851 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
 852                                    HeapRegion* hr)
 853   : _bosa(bosa), _strong_code_roots_list(NULL), _other_regions(hr) {
 854   reset_for_par_iteration();
 855 }
 856 
 857 void HeapRegionRemSet::setup_remset_size() {
 858   // Setup sparse and fine-grain tables sizes.
 859   // table_size = base * (log(region_size / 1M) + 1)
 860   const int LOG_M = 20;
 861   int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0);
 862   if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) {
 863     G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1);
 864   }
 865   if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) {
 866     G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1);
 867   }
 868   guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity");
 869 }
 870 
 871 bool HeapRegionRemSet::claim_iter() {
 872   if (_iter_state != Unclaimed) return false;
 873   jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed);
 874   return (res == Unclaimed);
 875 }
 876 
 877 void HeapRegionRemSet::set_iter_complete() {
 878   _iter_state = Complete;
 879 }
 880 
 881 bool HeapRegionRemSet::iter_is_complete() {
 882   return _iter_state == Complete;
 883 }
 884 
 885 #ifndef PRODUCT
 886 void HeapRegionRemSet::print() const {
 887   HeapRegionRemSetIterator iter(this);
 888   size_t card_index;
 889   while (iter.has_next(card_index)) {
 890     HeapWord* card_start =
 891       G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
 892     gclog_or_tty->print_cr("  Card " PTR_FORMAT, card_start);
 893   }
 894   if (iter.n_yielded() != occupied()) {
 895     gclog_or_tty->print_cr("Yielded disagrees with occupied:");
 896     gclog_or_tty->print_cr("  %6d yielded (%6d coarse, %6d fine).",
 897                   iter.n_yielded(),
 898                   iter.n_yielded_coarse(), iter.n_yielded_fine());
 899     gclog_or_tty->print_cr("  %6d occ     (%6d coarse, %6d fine).",
 900                   occupied(), occ_coarse(), occ_fine());
 901   }
 902   guarantee(iter.n_yielded() == occupied(),
 903             "We should have yielded all the represented cards.");
 904 }
 905 #endif
 906 
 907 void HeapRegionRemSet::cleanup() {
 908   SparsePRT::cleanup_all();
 909 }
 910 
 911 void HeapRegionRemSet::clear() {
 912   if (_strong_code_roots_list != NULL) {
 913     delete _strong_code_roots_list;
 914   }
 915   _strong_code_roots_list = new (ResourceObj::C_HEAP, mtGC)
 916                                 GrowableArray<nmethod*>(10, 0, NULL, true);
 917 
 918   _other_regions.clear();
 919   assert(occupied() == 0, "Should be clear.");
 920   reset_for_par_iteration();
 921 }
 922 
 923 void HeapRegionRemSet::reset_for_par_iteration() {
 924   _iter_state = Unclaimed;
 925   _iter_claimed = 0;
 926   // It's good to check this to make sure that the two methods are in sync.
 927   assert(verify_ready_for_par_iteration(), "post-condition");
 928 }
 929 
 930 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
 931                              BitMap* region_bm, BitMap* card_bm) {
 932   _other_regions.scrub(ctbs, region_bm, card_bm);
 933 }
 934 
 935 
 936 // Code roots support
 937 
 938 void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
 939   assert(nm != NULL, "sanity");
 940   // Search for the code blob from the RHS to avoid
 941   // duplicate entries as much as possible
 942   if (_strong_code_roots_list->find_from_end(nm) < 0) {
 943     // Code blob isn't already in the list
 944     _strong_code_roots_list->push(nm);
 945   }
 946 }
 947 
 948 void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
 949   assert(nm != NULL, "sanity");
 950   int idx = _strong_code_roots_list->find(nm);
 951   if (idx >= 0) {
 952     _strong_code_roots_list->remove_at(idx);
 953   }
 954   // Check that there were no duplicates
 955   guarantee(_strong_code_roots_list->find(nm) < 0, "duplicate entry found");
 956 }
 957 
 958 class NMethodMigrationOopClosure : public OopClosure {
 959   G1CollectedHeap* _g1h;
 960   HeapRegion* _from;
 961   nmethod* _nm;
 962 
 963   uint _num_self_forwarded;
 964 
 965   template <class T> void do_oop_work(T* p) {
 966     T heap_oop = oopDesc::load_heap_oop(p);
 967     if (!oopDesc::is_null(heap_oop)) {
 968       oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 969       if (_from->is_in(obj)) {
 970         // Reference still points into the source region.
 971         // Since roots are immediately evacuated this means that
 972         // we must have self forwarded the object
 973         assert(obj->is_forwarded(),
 974                err_msg("code roots should be immediately evacuated. "
 975                        "Ref: "PTR_FORMAT", "
 976                        "Obj: "PTR_FORMAT", "
 977                        "Region: "HR_FORMAT,
 978                        p, (void*) obj, HR_FORMAT_PARAMS(_from)));
 979         assert(obj->forwardee() == obj,
 980                err_msg("not self forwarded? obj = "PTR_FORMAT, (void*)obj));
 981 
 982         // The object has been self forwarded.
 983         // Note, if we're during an initial mark pause, there is
 984         // no need to explicitly mark object. It will be marked
 985         // during the regular evacuation failure handling code.
 986         _num_self_forwarded++;
 987       } else {
 988         // The reference points into a promotion or to-space region
 989         HeapRegion* to = _g1h->heap_region_containing(obj);
 990         to->rem_set()->add_strong_code_root(_nm);
 991       }
 992     }
 993   }
 994 
 995 public:
 996   NMethodMigrationOopClosure(G1CollectedHeap* g1h, HeapRegion* from, nmethod* nm):
 997     _g1h(g1h), _from(from), _nm(nm), _num_self_forwarded(0) {}
 998 
 999   void do_oop(narrowOop* p) { do_oop_work(p); }
1000   void do_oop(oop* p)       { do_oop_work(p); }
1001 
1002   uint retain() { return _num_self_forwarded > 0; }
1003 };
1004 
1005 void HeapRegionRemSet::migrate_strong_code_roots() {
1006   assert(hr()->in_collection_set(), "only collection set regions");
1007   assert(!hr()->isHumongous(), "humongous region moved?");
1008 
1009   ResourceMark rm;
1010 
1011   // List of code blobs to retain for this region
1012   GrowableArray<nmethod*> to_be_retained(10);
1013   G1CollectedHeap* g1h = G1CollectedHeap::heap();
1014 
1015   while (_strong_code_roots_list->is_nonempty()) {
1016     nmethod *nm = _strong_code_roots_list->pop();
1017     if (nm != NULL) {
1018       NMethodMigrationOopClosure oop_cl(g1h, hr(), nm);
1019       nm->oops_do(&oop_cl);
1020       if (oop_cl.retain()) {
1021         to_be_retained.push(nm);
1022       }
1023     }
1024   }
1025 
1026   // Now push any code roots we need to retain
1027   assert(to_be_retained.is_empty() || hr()->evacuation_failed(),
1028          "Retained nmethod list must be empty or "
1029          "evacuation of this region failed");
1030 
1031   while (to_be_retained.is_nonempty()) {
1032     nmethod* nm = to_be_retained.pop();
1033     assert(nm != NULL, "sanity");
1034     add_strong_code_root(nm);
1035   }
1036 }
1037 
1038 void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
1039   for (int i = 0; i < _strong_code_roots_list->length(); i += 1) {
1040     nmethod* nm = _strong_code_roots_list->at(i);
1041     blk->do_code_blob(nm);
1042   }
1043 }
1044 
1045 size_t HeapRegionRemSet::strong_code_roots_mem_size() {
1046   return sizeof(GrowableArray<nmethod*>) +
1047          _strong_code_roots_list->max_length() * sizeof(nmethod*);
1048 }
1049 
1050 //-------------------- Iteration --------------------
1051 
1052 HeapRegionRemSetIterator:: HeapRegionRemSetIterator(const HeapRegionRemSet* hrrs) :
1053   _hrrs(hrrs),
1054   _g1h(G1CollectedHeap::heap()),
1055   _coarse_map(&hrrs->_other_regions._coarse_map),
1056   _fine_grain_regions(hrrs->_other_regions._fine_grain_regions),
1057   _bosa(hrrs->bosa()),
1058   _is(Sparse),
1059   // Set these values so that we increment to the first region.
1060   _coarse_cur_region_index(-1),
1061   _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1),
1062   _cur_region_cur_card(0),
1063   _fine_array_index(-1),
1064   _fine_cur_prt(NULL),
1065   _n_yielded_coarse(0),
1066   _n_yielded_fine(0),
1067   _n_yielded_sparse(0),
1068   _sparse_iter(&hrrs->_other_regions._sparse_table) {}
1069 
1070 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) {
1071   if (_hrrs->_other_regions._n_coarse_entries == 0) return false;
1072   // Go to the next card.
1073   _coarse_cur_region_cur_card++;
1074   // Was the last the last card in the current region?
1075   if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) {
1076     // Yes: find the next region.  This may leave _coarse_cur_region_index
1077     // Set to the last index, in which case there are no more coarse
1078     // regions.
1079     _coarse_cur_region_index =
1080       (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1);
1081     if ((size_t)_coarse_cur_region_index < _coarse_map->size()) {
1082       _coarse_cur_region_cur_card = 0;
1083       HeapWord* r_bot =
1084         _g1h->region_at((uint) _coarse_cur_region_index)->bottom();
1085       _cur_region_card_offset = _bosa->index_for(r_bot);
1086     } else {
1087       return false;
1088     }
1089   }
1090   // If we didn't return false above, then we can yield a card.
1091   card_index = _cur_region_card_offset + _coarse_cur_region_cur_card;
1092   return true;
1093 }
1094 
1095 void HeapRegionRemSetIterator::fine_find_next_non_null_prt() {
1096   // Otherwise, find the next bucket list in the array.
1097   _fine_array_index++;
1098   while (_fine_array_index < (int) OtherRegionsTable::_max_fine_entries) {
1099     _fine_cur_prt = _fine_grain_regions[_fine_array_index];
1100     if (_fine_cur_prt != NULL) return;
1101     else _fine_array_index++;
1102   }
1103   assert(_fine_cur_prt == NULL, "Loop post");
1104 }
1105 
1106 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) {
1107   if (fine_has_next()) {
1108     _cur_region_cur_card =
1109       _fine_cur_prt->_bm.get_next_one_offset(_cur_region_cur_card + 1);
1110   }
1111   while (!fine_has_next()) {
1112     if (_cur_region_cur_card == (size_t) HeapRegion::CardsPerRegion) {
1113       _cur_region_cur_card = 0;
1114       _fine_cur_prt = _fine_cur_prt->collision_list_next();
1115     }
1116     if (_fine_cur_prt == NULL) {
1117       fine_find_next_non_null_prt();
1118       if (_fine_cur_prt == NULL) return false;
1119     }
1120     assert(_fine_cur_prt != NULL && _cur_region_cur_card == 0,
1121            "inv.");
1122     HeapWord* r_bot =
1123       _fine_cur_prt->hr()->bottom();
1124     _cur_region_card_offset = _bosa->index_for(r_bot);
1125     _cur_region_cur_card = _fine_cur_prt->_bm.get_next_one_offset(0);
1126   }
1127   assert(fine_has_next(), "Or else we exited the loop via the return.");
1128   card_index = _cur_region_card_offset + _cur_region_cur_card;
1129   return true;
1130 }
1131 
1132 bool HeapRegionRemSetIterator::fine_has_next() {
1133   return
1134     _fine_cur_prt != NULL &&
1135     _cur_region_cur_card < HeapRegion::CardsPerRegion;
1136 }
1137 
1138 bool HeapRegionRemSetIterator::has_next(size_t& card_index) {
1139   switch (_is) {
1140   case Sparse:
1141     if (_sparse_iter.has_next(card_index)) {
1142       _n_yielded_sparse++;
1143       return true;
1144     }
1145     // Otherwise, deliberate fall-through
1146     _is = Fine;
1147   case Fine:
1148     if (fine_has_next(card_index)) {
1149       _n_yielded_fine++;
1150       return true;
1151     }
1152     // Otherwise, deliberate fall-through
1153     _is = Coarse;
1154   case Coarse:
1155     if (coarse_has_next(card_index)) {
1156       _n_yielded_coarse++;
1157       return true;
1158     }
1159     // Otherwise...
1160     break;
1161   }
1162   assert(ParallelGCThreads > 1 ||
1163          n_yielded() == _hrrs->occupied(),
1164          "Should have yielded all the cards in the rem set "
1165          "(in the non-par case).");
1166   return false;
1167 }
1168 
1169 
1170 
1171 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL;
1172 HeapWord**          HeapRegionRemSet::_recorded_cards = NULL;
1173 HeapRegion**        HeapRegionRemSet::_recorded_regions = NULL;
1174 int                 HeapRegionRemSet::_n_recorded = 0;
1175 
1176 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL;
1177 int*         HeapRegionRemSet::_recorded_event_index = NULL;
1178 int          HeapRegionRemSet::_n_recorded_events = 0;
1179 
1180 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) {
1181   if (_recorded_oops == NULL) {
1182     assert(_n_recorded == 0
1183            && _recorded_cards == NULL
1184            && _recorded_regions == NULL,
1185            "Inv");
1186     _recorded_oops    = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded, mtGC);
1187     _recorded_cards   = NEW_C_HEAP_ARRAY(HeapWord*,          MaxRecorded, mtGC);
1188     _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*,        MaxRecorded, mtGC);
1189   }
1190   if (_n_recorded == MaxRecorded) {
1191     gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded);
1192   } else {
1193     _recorded_cards[_n_recorded] =
1194       (HeapWord*)align_size_down(uintptr_t(f),
1195                                  CardTableModRefBS::card_size);
1196     _recorded_oops[_n_recorded] = f;
1197     _recorded_regions[_n_recorded] = hr;
1198     _n_recorded++;
1199   }
1200 }
1201 
1202 void HeapRegionRemSet::record_event(Event evnt) {
1203   if (!G1RecordHRRSEvents) return;
1204 
1205   if (_recorded_events == NULL) {
1206     assert(_n_recorded_events == 0
1207            && _recorded_event_index == NULL,
1208            "Inv");
1209     _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents, mtGC);
1210     _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents, mtGC);
1211   }
1212   if (_n_recorded_events == MaxRecordedEvents) {
1213     gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents);
1214   } else {
1215     _recorded_events[_n_recorded_events] = evnt;
1216     _recorded_event_index[_n_recorded_events] = _n_recorded;
1217     _n_recorded_events++;
1218   }
1219 }
1220 
1221 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) {
1222   switch (evnt) {
1223   case Event_EvacStart:
1224     str->print("Evac Start");
1225     break;
1226   case Event_EvacEnd:
1227     str->print("Evac End");
1228     break;
1229   case Event_RSUpdateEnd:
1230     str->print("RS Update End");
1231     break;
1232   }
1233 }
1234 
1235 void HeapRegionRemSet::print_recorded() {
1236   int cur_evnt = 0;
1237   Event cur_evnt_kind;
1238   int cur_evnt_ind = 0;
1239   if (_n_recorded_events > 0) {
1240     cur_evnt_kind = _recorded_events[cur_evnt];
1241     cur_evnt_ind = _recorded_event_index[cur_evnt];
1242   }
1243 
1244   for (int i = 0; i < _n_recorded; i++) {
1245     while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) {
1246       gclog_or_tty->print("Event: ");
1247       print_event(gclog_or_tty, cur_evnt_kind);
1248       gclog_or_tty->print_cr("");
1249       cur_evnt++;
1250       if (cur_evnt < MaxRecordedEvents) {
1251         cur_evnt_kind = _recorded_events[cur_evnt];
1252         cur_evnt_ind = _recorded_event_index[cur_evnt];
1253       }
1254     }
1255     gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]"
1256                         " for ref " PTR_FORMAT ".\n",
1257                         _recorded_cards[i], _recorded_regions[i]->bottom(),
1258                         _recorded_oops[i]);
1259   }
1260 }
1261 
1262 void HeapRegionRemSet::reset_for_cleanup_tasks() {
1263   SparsePRT::reset_for_cleanup_tasks();
1264 }
1265 
1266 void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
1267   _other_regions.do_cleanup_work(hrrs_cleanup_task);
1268 }
1269 
1270 void
1271 HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) {
1272   SparsePRT::finish_cleanup_task(hrrs_cleanup_task);
1273 }
1274 
1275 #ifndef PRODUCT
1276 void PerRegionTable::test_fl_mem_size() {
1277   PerRegionTable* dummy = alloc(NULL);
1278   free(dummy);
1279   guarantee(dummy->mem_size() == fl_mem_size(), "fl_mem_size() does not return the correct element size");
1280   // try to reset the state
1281   _free_list = NULL;
1282   delete dummy;
1283 }
1284 
1285 void HeapRegionRemSet::test_prt() {
1286   PerRegionTable::test_fl_mem_size();
1287 }
1288 
1289 void HeapRegionRemSet::test() {
1290   os::sleep(Thread::current(), (jlong)5000, false);
1291   G1CollectedHeap* g1h = G1CollectedHeap::heap();
1292 
1293   // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same
1294   // hash bucket.
1295   HeapRegion* hr0 = g1h->region_at(0);
1296   HeapRegion* hr1 = g1h->region_at(1);
1297   HeapRegion* hr2 = g1h->region_at(5);
1298   HeapRegion* hr3 = g1h->region_at(6);
1299   HeapRegion* hr4 = g1h->region_at(7);
1300   HeapRegion* hr5 = g1h->region_at(8);
1301 
1302   HeapWord* hr1_start = hr1->bottom();
1303   HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2;
1304   HeapWord* hr1_last = hr1->end() - 1;
1305 
1306   HeapWord* hr2_start = hr2->bottom();
1307   HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2;
1308   HeapWord* hr2_last = hr2->end() - 1;
1309 
1310   HeapWord* hr3_start = hr3->bottom();
1311   HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2;
1312   HeapWord* hr3_last = hr3->end() - 1;
1313 
1314   HeapRegionRemSet* hrrs = hr0->rem_set();
1315 
1316   // Make three references from region 0x101...
1317   hrrs->add_reference((OopOrNarrowOopStar)hr1_start);
1318   hrrs->add_reference((OopOrNarrowOopStar)hr1_mid);
1319   hrrs->add_reference((OopOrNarrowOopStar)hr1_last);
1320 
1321   hrrs->add_reference((OopOrNarrowOopStar)hr2_start);
1322   hrrs->add_reference((OopOrNarrowOopStar)hr2_mid);
1323   hrrs->add_reference((OopOrNarrowOopStar)hr2_last);
1324 
1325   hrrs->add_reference((OopOrNarrowOopStar)hr3_start);
1326   hrrs->add_reference((OopOrNarrowOopStar)hr3_mid);
1327   hrrs->add_reference((OopOrNarrowOopStar)hr3_last);
1328 
1329   // Now cause a coarsening.
1330   hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom());
1331   hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom());
1332 
1333   // Now, does iteration yield these three?
1334   HeapRegionRemSetIterator iter(hrrs);
1335   size_t sum = 0;
1336   size_t card_index;
1337   while (iter.has_next(card_index)) {
1338     HeapWord* card_start =
1339       G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
1340     gclog_or_tty->print_cr("  Card " PTR_FORMAT ".", card_start);
1341     sum++;
1342   }
1343   guarantee(sum == 11 - 3 + 2048, "Failure");
1344   guarantee(sum == hrrs->occupied(), "Failure");
1345 }
1346 #endif
--- EOF ---