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/heapRegionManager.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 "runtime/atomic.inline.hpp"
  36 #include "utilities/bitMap.inline.hpp"
  37 #include "utilities/globalDefinitions.hpp"
  38 #include "utilities/growableArray.hpp"
  39 
  40 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  41 
  42 class PerRegionTable: public CHeapObj<mtGC> {
  43   friend class OtherRegionsTable;
  44   friend class HeapRegionRemSetIterator;
  45 
  46   HeapRegion*     _hr;
  47   BitMap          _bm;
  48   jint            _occupied;
  49 
  50   // next pointer for free/allocated 'all' list
  51   PerRegionTable* _next;
  52 
  53   // prev pointer for the allocated 'all' list
  54   PerRegionTable* _prev;
  55 
  56   // next pointer in collision list
  57   PerRegionTable * _collision_list_next;
  58 
  59   // Global free list of PRTs
  60   static PerRegionTable* _free_list;
  61 
  62 protected:
  63   // We need access in order to union things into the base table.
  64   BitMap* bm() { return &_bm; }
  65 
  66   void recount_occupied() {
  67     _occupied = (jint) bm()->count_one_bits();
  68   }
  69 
  70   PerRegionTable(HeapRegion* hr) :
  71     _hr(hr),
  72     _occupied(0),
  73     _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */),
  74     _collision_list_next(NULL), _next(NULL), _prev(NULL)
  75   {}
  76 
  77   void add_card_work(CardIdx_t from_card, bool par) {
  78     if (!_bm.at(from_card)) {
  79       if (par) {
  80         if (_bm.par_at_put(from_card, 1)) {
  81           Atomic::inc(&_occupied);
  82         }
  83       } else {
  84         _bm.at_put(from_card, 1);
  85         _occupied++;
  86       }
  87     }
  88   }
  89 
  90   void add_reference_work(OopOrNarrowOopStar from, bool par) {
  91     // Must make this robust in case "from" is not in "_hr", because of
  92     // concurrency.
  93 
  94     if (G1TraceHeapRegionRememberedSet) {
  95       gclog_or_tty->print_cr("    PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT").",
  96                              from,
  97                              UseCompressedOops
  98                              ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
  99                              : (void *)oopDesc::load_decode_heap_oop((oop*)from));
 100     }
 101 
 102     HeapRegion* loc_hr = hr();
 103     // If the test below fails, then this table was reused concurrently
 104     // with this operation.  This is OK, since the old table was coarsened,
 105     // and adding a bit to the new table is never incorrect.
 106     // If the table used to belong to a continues humongous region and is
 107     // now reused for the corresponding start humongous region, we need to
 108     // make sure that we detect this. Thus, we call is_in_reserved_raw()
 109     // instead of just is_in_reserved() here.
 110     if (loc_hr->is_in_reserved_raw(from)) {
 111       size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom());
 112       CardIdx_t from_card = (CardIdx_t)
 113           hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize);
 114 
 115       assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion,
 116              "Must be in range.");
 117       add_card_work(from_card, par);
 118     }
 119   }
 120 
 121 public:
 122 
 123   HeapRegion* hr() const { return _hr; }
 124 
 125   jint occupied() const {
 126     // Overkill, but if we ever need it...
 127     // guarantee(_occupied == _bm.count_one_bits(), "Check");
 128     return _occupied;
 129   }
 130 
 131   void init(HeapRegion* hr, bool clear_links_to_all_list) {
 132     if (clear_links_to_all_list) {
 133       set_next(NULL);
 134       set_prev(NULL);
 135     }
 136     _hr = hr;
 137     _collision_list_next = NULL;
 138     _occupied = 0;
 139     _bm.clear();
 140   }
 141 
 142   void add_reference(OopOrNarrowOopStar from) {
 143     add_reference_work(from, /*parallel*/ true);
 144   }
 145 
 146   void seq_add_reference(OopOrNarrowOopStar from) {
 147     add_reference_work(from, /*parallel*/ false);
 148   }
 149 
 150   void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) {
 151     HeapWord* hr_bot = hr()->bottom();
 152     size_t hr_first_card_index = ctbs->index_for(hr_bot);
 153     bm()->set_intersection_at_offset(*card_bm, hr_first_card_index);
 154     recount_occupied();
 155   }
 156 
 157   void add_card(CardIdx_t from_card_index) {
 158     add_card_work(from_card_index, /*parallel*/ true);
 159   }
 160 
 161   void seq_add_card(CardIdx_t from_card_index) {
 162     add_card_work(from_card_index, /*parallel*/ false);
 163   }
 164 
 165   // (Destructively) union the bitmap of the current table into the given
 166   // bitmap (which is assumed to be of the same size.)
 167   void union_bitmap_into(BitMap* bm) {
 168     bm->set_union(_bm);
 169   }
 170 
 171   // Mem size in bytes.
 172   size_t mem_size() const {
 173     return sizeof(PerRegionTable) + _bm.size_in_words() * HeapWordSize;
 174   }
 175 
 176   // Requires "from" to be in "hr()".
 177   bool contains_reference(OopOrNarrowOopStar from) const {
 178     assert(hr()->is_in_reserved(from), "Precondition.");
 179     size_t card_ind = pointer_delta(from, hr()->bottom(),
 180                                     CardTableModRefBS::card_size);
 181     return _bm.at(card_ind);
 182   }
 183 
 184   // Bulk-free the PRTs from prt to last, assumes that they are
 185   // linked together using their _next field.
 186   static void bulk_free(PerRegionTable* prt, PerRegionTable* last) {
 187     while (true) {
 188       PerRegionTable* fl = _free_list;
 189       last->set_next(fl);
 190       PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl);
 191       if (res == fl) {
 192         return;
 193       }
 194     }
 195     ShouldNotReachHere();
 196   }
 197 
 198   static void free(PerRegionTable* prt) {
 199     bulk_free(prt, prt);
 200   }
 201 
 202   // Returns an initialized PerRegionTable instance.
 203   static PerRegionTable* alloc(HeapRegion* hr) {
 204     PerRegionTable* fl = _free_list;
 205     while (fl != NULL) {
 206       PerRegionTable* nxt = fl->next();
 207       PerRegionTable* res =
 208         (PerRegionTable*)
 209         Atomic::cmpxchg_ptr(nxt, &_free_list, fl);
 210       if (res == fl) {
 211         fl->init(hr, true);
 212         return fl;
 213       } else {
 214         fl = _free_list;
 215       }
 216     }
 217     assert(fl == NULL, "Loop condition.");
 218     return new PerRegionTable(hr);
 219   }
 220 
 221   PerRegionTable* next() const { return _next; }
 222   void set_next(PerRegionTable* next) { _next = next; }
 223   PerRegionTable* prev() const { return _prev; }
 224   void set_prev(PerRegionTable* prev) { _prev = prev; }
 225 
 226   // Accessor and Modification routines for the pointer for the
 227   // singly linked collision list that links the PRTs within the
 228   // OtherRegionsTable::_fine_grain_regions hash table.
 229   //
 230   // It might be useful to also make the collision list doubly linked
 231   // to avoid iteration over the collisions list during scrubbing/deletion.
 232   // OTOH there might not be many collisions.
 233 
 234   PerRegionTable* collision_list_next() const {
 235     return _collision_list_next;
 236   }
 237 
 238   void set_collision_list_next(PerRegionTable* next) {
 239     _collision_list_next = next;
 240   }
 241 
 242   PerRegionTable** collision_list_next_addr() {
 243     return &_collision_list_next;
 244   }
 245 
 246   static size_t fl_mem_size() {
 247     PerRegionTable* cur = _free_list;
 248     size_t res = 0;
 249     while (cur != NULL) {
 250       res += cur->mem_size();
 251       cur = cur->next();
 252     }
 253     return res;
 254   }
 255 
 256   static void test_fl_mem_size();
 257 };
 258 
 259 PerRegionTable* PerRegionTable::_free_list = NULL;
 260 
 261 size_t OtherRegionsTable::_max_fine_entries = 0;
 262 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
 263 size_t OtherRegionsTable::_fine_eviction_stride = 0;
 264 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
 265 
 266 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) :
 267   _g1h(G1CollectedHeap::heap()),
 268   _hr(hr), _m(m),
 269   _coarse_map(G1CollectedHeap::heap()->max_regions(),
 270               false /* in-resource-area */),
 271   _fine_grain_regions(NULL),
 272   _first_all_fine_prts(NULL), _last_all_fine_prts(NULL),
 273   _n_fine_entries(0), _n_coarse_entries(0),
 274   _fine_eviction_start(0),
 275   _sparse_table(hr)
 276 {
 277   typedef PerRegionTable* PerRegionTablePtr;
 278 
 279   if (_max_fine_entries == 0) {
 280     assert(_mod_max_fine_entries_mask == 0, "Both or none.");
 281     size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
 282     _max_fine_entries = (size_t)1 << max_entries_log;
 283     _mod_max_fine_entries_mask = _max_fine_entries - 1;
 284 
 285     assert(_fine_eviction_sample_size == 0
 286            && _fine_eviction_stride == 0, "All init at same time.");
 287     _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
 288     _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
 289   }
 290 
 291   _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries,
 292                         mtGC, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
 293 
 294   if (_fine_grain_regions == NULL) {
 295     vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR,
 296                           "Failed to allocate _fine_grain_entries.");
 297   }
 298 
 299   for (size_t i = 0; i < _max_fine_entries; i++) {
 300     _fine_grain_regions[i] = NULL;
 301   }
 302 }
 303 
 304 void OtherRegionsTable::link_to_all(PerRegionTable* prt) {
 305   // We always append to the beginning of the list for convenience;
 306   // the order of entries in this list does not matter.
 307   if (_first_all_fine_prts != NULL) {
 308     assert(_first_all_fine_prts->prev() == NULL, "invariant");
 309     _first_all_fine_prts->set_prev(prt);
 310     prt->set_next(_first_all_fine_prts);
 311   } else {
 312     // this is the first element we insert. Adjust the "last" pointer
 313     _last_all_fine_prts = prt;
 314     assert(prt->next() == NULL, "just checking");
 315   }
 316   // the new element is always the first element without a predecessor
 317   prt->set_prev(NULL);
 318   _first_all_fine_prts = prt;
 319 
 320   assert(prt->prev() == NULL, "just checking");
 321   assert(_first_all_fine_prts == prt, "just checking");
 322   assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
 323          (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
 324          "just checking");
 325   assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
 326          "just checking");
 327   assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
 328          "just checking");
 329 }
 330 
 331 void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) {
 332   if (prt->prev() != NULL) {
 333     assert(_first_all_fine_prts != prt, "just checking");
 334     prt->prev()->set_next(prt->next());
 335     // removing the last element in the list?
 336     if (_last_all_fine_prts == prt) {
 337       _last_all_fine_prts = prt->prev();
 338     }
 339   } else {
 340     assert(_first_all_fine_prts == prt, "just checking");
 341     _first_all_fine_prts = prt->next();
 342     // list is empty now?
 343     if (_first_all_fine_prts == NULL) {
 344       _last_all_fine_prts = NULL;
 345     }
 346   }
 347 
 348   if (prt->next() != NULL) {
 349     prt->next()->set_prev(prt->prev());
 350   }
 351 
 352   prt->set_next(NULL);
 353   prt->set_prev(NULL);
 354 
 355   assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) ||
 356          (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL),
 357          "just checking");
 358   assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL,
 359          "just checking");
 360   assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL,
 361          "just checking");
 362 }
 363 
 364 int**  FromCardCache::_cache = NULL;
 365 uint   FromCardCache::_max_regions = 0;
 366 size_t FromCardCache::_static_mem_size = 0;
 367 
 368 void FromCardCache::initialize(uint n_par_rs, uint max_num_regions) {
 369   guarantee(_cache == NULL, "Should not call this multiple times");
 370 
 371   _max_regions = max_num_regions;
 372   _cache = Padded2DArray<int, mtGC>::create_unfreeable(n_par_rs,
 373                                                        _max_regions,
 374                                                        &_static_mem_size);
 375 
 376   invalidate(0, _max_regions);
 377 }
 378 
 379 void FromCardCache::invalidate(uint start_idx, size_t new_num_regions) {
 380   guarantee((size_t)start_idx + new_num_regions <= max_uintx,
 381             err_msg("Trying to invalidate beyond maximum region, from %u size "SIZE_FORMAT,
 382                     start_idx, new_num_regions));
 383   for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
 384     uint end_idx = (start_idx + (uint)new_num_regions);
 385     assert(end_idx <= _max_regions, "Must be within max.");
 386     for (uint j = start_idx; j < end_idx; j++) {
 387       set(i, j, InvalidCard);
 388     }
 389   }
 390 }
 391 
 392 #ifndef PRODUCT
 393 void FromCardCache::print(outputStream* out) {
 394   for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
 395     for (uint j = 0; j < _max_regions; j++) {
 396       out->print_cr("_from_card_cache[%u][%u] = %d.",
 397                     i, j, at(i, j));
 398     }
 399   }
 400 }
 401 #endif
 402 
 403 void FromCardCache::clear(uint region_idx) {
 404   uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets();
 405   for (uint i = 0; i < num_par_remsets; i++) {
 406     set(i, region_idx, InvalidCard);
 407   }
 408 }
 409 
 410 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, uint tid) {
 411   uint cur_hrm_ind = _hr->hrm_index();
 412 
 413   if (G1TraceHeapRegionRememberedSet) {
 414     gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").",
 415                                                     from,
 416                                                     UseCompressedOops
 417                                                     ? (void *)oopDesc::load_decode_heap_oop((narrowOop*)from)
 418                                                     : (void *)oopDesc::load_decode_heap_oop((oop*)from));
 419   }
 420 
 421   int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift);
 422 
 423   if (G1TraceHeapRegionRememberedSet) {
 424     gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)",
 425                   _hr->bottom(), from_card,
 426                   FromCardCache::at(tid, cur_hrm_ind));
 427   }
 428 
 429   if (FromCardCache::contains_or_replace(tid, cur_hrm_ind, from_card)) {
 430     if (G1TraceHeapRegionRememberedSet) {
 431       gclog_or_tty->print_cr("  from-card cache hit.");
 432     }
 433     assert(contains_reference(from), "We just added it!");
 434     return;
 435   }
 436 
 437   // Note that this may be a continued H region.
 438   HeapRegion* from_hr = _g1h->heap_region_containing_raw(from);
 439   RegionIdx_t from_hrm_ind = (RegionIdx_t) from_hr->hrm_index();
 440 
 441   // If the region is already coarsened, return.
 442   if (_coarse_map.at(from_hrm_ind)) {
 443     if (G1TraceHeapRegionRememberedSet) {
 444       gclog_or_tty->print_cr("  coarse map hit.");
 445     }
 446     assert(contains_reference(from), "We just added it!");
 447     return;
 448   }
 449 
 450   // Otherwise find a per-region table to add it to.
 451   size_t ind = from_hrm_ind & _mod_max_fine_entries_mask;
 452   PerRegionTable* prt = find_region_table(ind, from_hr);
 453   if (prt == NULL) {
 454     MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
 455     // Confirm that it's really not there...
 456     prt = find_region_table(ind, from_hr);
 457     if (prt == NULL) {
 458 
 459       uintptr_t from_hr_bot_card_index =
 460         uintptr_t(from_hr->bottom())
 461           >> CardTableModRefBS::card_shift;
 462       CardIdx_t card_index = from_card - from_hr_bot_card_index;
 463       assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
 464              "Must be in range.");
 465       if (G1HRRSUseSparseTable &&
 466           _sparse_table.add_card(from_hrm_ind, card_index)) {
 467         if (G1RecordHRRSOops) {
 468           HeapRegionRemSet::record(_hr, from);
 469           if (G1TraceHeapRegionRememberedSet) {
 470             gclog_or_tty->print("   Added card " PTR_FORMAT " to region "
 471                                 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
 472                                 align_size_down(uintptr_t(from),
 473                                                 CardTableModRefBS::card_size),
 474                                 _hr->bottom(), from);
 475           }
 476         }
 477         if (G1TraceHeapRegionRememberedSet) {
 478           gclog_or_tty->print_cr("   added card to sparse table.");
 479         }
 480         assert(contains_reference_locked(from), "We just added it!");
 481         return;
 482       } else {
 483         if (G1TraceHeapRegionRememberedSet) {
 484           gclog_or_tty->print_cr("   [tid %u] sparse table entry "
 485                         "overflow(f: %d, t: %u)",
 486                         tid, from_hrm_ind, cur_hrm_ind);
 487         }
 488       }
 489 
 490       if (_n_fine_entries == _max_fine_entries) {
 491         prt = delete_region_table();
 492         // There is no need to clear the links to the 'all' list here:
 493         // prt will be reused immediately, i.e. remain in the 'all' list.
 494         prt->init(from_hr, false /* clear_links_to_all_list */);
 495       } else {
 496         prt = PerRegionTable::alloc(from_hr);
 497         link_to_all(prt);
 498       }
 499 
 500       PerRegionTable* first_prt = _fine_grain_regions[ind];
 501       prt->set_collision_list_next(first_prt);
 502       _fine_grain_regions[ind] = prt;
 503       _n_fine_entries++;
 504 
 505       if (G1HRRSUseSparseTable) {
 506         // Transfer from sparse to fine-grain.
 507         SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrm_ind);
 508         assert(sprt_entry != NULL, "There should have been an entry");
 509         for (int i = 0; i < SparsePRTEntry::cards_num(); i++) {
 510           CardIdx_t c = sprt_entry->card(i);
 511           if (c != SparsePRTEntry::NullEntry) {
 512             prt->add_card(c);
 513           }
 514         }
 515         // Now we can delete the sparse entry.
 516         bool res = _sparse_table.delete_entry(from_hrm_ind);
 517         assert(res, "It should have been there.");
 518       }
 519     }
 520     assert(prt != NULL && prt->hr() == from_hr, "consequence");
 521   }
 522   // Note that we can't assert "prt->hr() == from_hr", because of the
 523   // possibility of concurrent reuse.  But see head comment of
 524   // OtherRegionsTable for why this is OK.
 525   assert(prt != NULL, "Inv");
 526 
 527   prt->add_reference(from);
 528 
 529   if (G1RecordHRRSOops) {
 530     HeapRegionRemSet::record(_hr, from);
 531     if (G1TraceHeapRegionRememberedSet) {
 532       gclog_or_tty->print("Added card " PTR_FORMAT " to region "
 533                           "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n",
 534                           align_size_down(uintptr_t(from),
 535                                           CardTableModRefBS::card_size),
 536                           _hr->bottom(), from);
 537     }
 538   }
 539   assert(contains_reference(from), "We just added it!");
 540 }
 541 
 542 PerRegionTable*
 543 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const {
 544   assert(0 <= ind && ind < _max_fine_entries, "Preconditions.");
 545   PerRegionTable* prt = _fine_grain_regions[ind];
 546   while (prt != NULL && prt->hr() != hr) {
 547     prt = prt->collision_list_next();
 548   }
 549   // Loop postcondition is the method postcondition.
 550   return prt;
 551 }
 552 
 553 jint OtherRegionsTable::_n_coarsenings = 0;
 554 
 555 PerRegionTable* OtherRegionsTable::delete_region_table() {
 556   assert(_m->owned_by_self(), "Precondition");
 557   assert(_n_fine_entries == _max_fine_entries, "Precondition");
 558   PerRegionTable* max = NULL;
 559   jint max_occ = 0;
 560   PerRegionTable** max_prev;
 561   size_t max_ind;
 562 
 563   size_t i = _fine_eviction_start;
 564   for (size_t k = 0; k < _fine_eviction_sample_size; k++) {
 565     size_t ii = i;
 566     // Make sure we get a non-NULL sample.
 567     while (_fine_grain_regions[ii] == NULL) {
 568       ii++;
 569       if (ii == _max_fine_entries) ii = 0;
 570       guarantee(ii != i, "We must find one.");
 571     }
 572     PerRegionTable** prev = &_fine_grain_regions[ii];
 573     PerRegionTable* cur = *prev;
 574     while (cur != NULL) {
 575       jint cur_occ = cur->occupied();
 576       if (max == NULL || cur_occ > max_occ) {
 577         max = cur;
 578         max_prev = prev;
 579         max_ind = i;
 580         max_occ = cur_occ;
 581       }
 582       prev = cur->collision_list_next_addr();
 583       cur = cur->collision_list_next();
 584     }
 585     i = i + _fine_eviction_stride;
 586     if (i >= _n_fine_entries) i = i - _n_fine_entries;
 587   }
 588 
 589   _fine_eviction_start++;
 590 
 591   if (_fine_eviction_start >= _n_fine_entries) {
 592     _fine_eviction_start -= _n_fine_entries;
 593   }
 594 
 595   guarantee(max != NULL, "Since _n_fine_entries > 0");
 596 
 597   // Set the corresponding coarse bit.
 598   size_t max_hrm_index = (size_t) max->hr()->hrm_index();
 599   if (!_coarse_map.at(max_hrm_index)) {
 600     _coarse_map.at_put(max_hrm_index, true);
 601     _n_coarse_entries++;
 602     if (G1TraceHeapRegionRememberedSet) {
 603       gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] "
 604                  "for region [" PTR_FORMAT "...] (" SIZE_FORMAT " coarse entries).\n",
 605                  _hr->bottom(),
 606                  max->hr()->bottom(),
 607                  _n_coarse_entries);
 608     }
 609   }
 610 
 611   // Unsplice.
 612   *max_prev = max->collision_list_next();
 613   Atomic::inc(&_n_coarsenings);
 614   _n_fine_entries--;
 615   return max;
 616 }
 617 
 618 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs,
 619                               BitMap* region_bm, BitMap* card_bm) {
 620   // First eliminated garbage regions from the coarse map.
 621   if (G1RSScrubVerbose) {
 622     gclog_or_tty->print_cr("Scrubbing region %u:", _hr->hrm_index());
 623   }
 624 
 625   assert(_coarse_map.size() == region_bm->size(), "Precondition");
 626   if (G1RSScrubVerbose) {
 627     gclog_or_tty->print("   Coarse map: before = "SIZE_FORMAT"...",
 628                         _n_coarse_entries);
 629   }
 630   _coarse_map.set_intersection(*region_bm);
 631   _n_coarse_entries = _coarse_map.count_one_bits();
 632   if (G1RSScrubVerbose) {
 633     gclog_or_tty->print_cr("   after = "SIZE_FORMAT".", _n_coarse_entries);
 634   }
 635 
 636   // Now do the fine-grained maps.
 637   for (size_t i = 0; i < _max_fine_entries; i++) {
 638     PerRegionTable* cur = _fine_grain_regions[i];
 639     PerRegionTable** prev = &_fine_grain_regions[i];
 640     while (cur != NULL) {
 641       PerRegionTable* nxt = cur->collision_list_next();
 642       // If the entire region is dead, eliminate.
 643       if (G1RSScrubVerbose) {
 644         gclog_or_tty->print_cr("     For other region %u:",
 645                                cur->hr()->hrm_index());
 646       }
 647       if (!region_bm->at((size_t) cur->hr()->hrm_index())) {
 648         *prev = nxt;
 649         cur->set_collision_list_next(NULL);
 650         _n_fine_entries--;
 651         if (G1RSScrubVerbose) {
 652           gclog_or_tty->print_cr("          deleted via region map.");
 653         }
 654         unlink_from_all(cur);
 655         PerRegionTable::free(cur);
 656       } else {
 657         // Do fine-grain elimination.
 658         if (G1RSScrubVerbose) {
 659           gclog_or_tty->print("          occ: before = %4d.", cur->occupied());
 660         }
 661         cur->scrub(ctbs, card_bm);
 662         if (G1RSScrubVerbose) {
 663           gclog_or_tty->print_cr("          after = %4d.", cur->occupied());
 664         }
 665         // Did that empty the table completely?
 666         if (cur->occupied() == 0) {
 667           *prev = nxt;
 668           cur->set_collision_list_next(NULL);
 669           _n_fine_entries--;
 670           unlink_from_all(cur);
 671           PerRegionTable::free(cur);
 672         } else {
 673           prev = cur->collision_list_next_addr();
 674         }
 675       }
 676       cur = nxt;
 677     }
 678   }
 679   // Since we may have deleted a from_card_cache entry from the RS, clear
 680   // the FCC.
 681   clear_fcc();
 682 }
 683 
 684 bool OtherRegionsTable::occupancy_less_or_equal_than(size_t limit) const {
 685   if (limit <= (size_t)G1RSetSparseRegionEntries) {
 686     return occ_coarse() == 0 && _first_all_fine_prts == NULL && occ_sparse() <= limit;
 687   } else {
 688     // Current uses of this method may only use values less than G1RSetSparseRegionEntries
 689     // for the limit. The solution, comparing against occupied() would be too slow
 690     // at this time.
 691     Unimplemented();
 692     return false;
 693   }
 694 }
 695 
 696 bool OtherRegionsTable::is_empty() const {
 697   return occ_sparse() == 0 && occ_coarse() == 0 && _first_all_fine_prts == NULL;
 698 }
 699 
 700 size_t OtherRegionsTable::occupied() const {
 701   size_t sum = occ_fine();
 702   sum += occ_sparse();
 703   sum += occ_coarse();
 704   return sum;
 705 }
 706 
 707 size_t OtherRegionsTable::occ_fine() const {
 708   size_t sum = 0;
 709 
 710   size_t num = 0;
 711   PerRegionTable * cur = _first_all_fine_prts;
 712   while (cur != NULL) {
 713     sum += cur->occupied();
 714     cur = cur->next();
 715     num++;
 716   }
 717   guarantee(num == _n_fine_entries, "just checking");
 718   return sum;
 719 }
 720 
 721 size_t OtherRegionsTable::occ_coarse() const {
 722   return (_n_coarse_entries * HeapRegion::CardsPerRegion);
 723 }
 724 
 725 size_t OtherRegionsTable::occ_sparse() const {
 726   return _sparse_table.occupied();
 727 }
 728 
 729 size_t OtherRegionsTable::mem_size() const {
 730   size_t sum = 0;
 731   // all PRTs are of the same size so it is sufficient to query only one of them.
 732   if (_first_all_fine_prts != NULL) {
 733     assert(_last_all_fine_prts != NULL &&
 734       _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant");
 735     sum += _first_all_fine_prts->mem_size() * _n_fine_entries;
 736   }
 737   sum += (sizeof(PerRegionTable*) * _max_fine_entries);
 738   sum += (_coarse_map.size_in_words() * HeapWordSize);
 739   sum += (_sparse_table.mem_size());
 740   sum += sizeof(OtherRegionsTable) - sizeof(_sparse_table); // Avoid double counting above.
 741   return sum;
 742 }
 743 
 744 size_t OtherRegionsTable::static_mem_size() {
 745   return FromCardCache::static_mem_size();
 746 }
 747 
 748 size_t OtherRegionsTable::fl_mem_size() {
 749   return PerRegionTable::fl_mem_size();
 750 }
 751 
 752 void OtherRegionsTable::clear_fcc() {
 753   FromCardCache::clear(_hr->hrm_index());
 754 }
 755 
 756 void OtherRegionsTable::clear() {
 757   // if there are no entries, skip this step
 758   if (_first_all_fine_prts != NULL) {
 759     guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
 760     PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts);
 761     memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0]));
 762   } else {
 763     guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking");
 764   }
 765 
 766   _first_all_fine_prts = _last_all_fine_prts = NULL;
 767   _sparse_table.clear();
 768   _coarse_map.clear();
 769   _n_fine_entries = 0;
 770   _n_coarse_entries = 0;
 771 
 772   clear_fcc();
 773 }
 774 
 775 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
 776   // Cast away const in this case.
 777   MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag);
 778   return contains_reference_locked(from);
 779 }
 780 
 781 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
 782   HeapRegion* hr = _g1h->heap_region_containing_raw(from);
 783   RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index();
 784   // Is this region in the coarse map?
 785   if (_coarse_map.at(hr_ind)) return true;
 786 
 787   PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
 788                                      hr);
 789   if (prt != NULL) {
 790     return prt->contains_reference(from);
 791 
 792   } else {
 793     uintptr_t from_card =
 794       (uintptr_t(from) >> CardTableModRefBS::card_shift);
 795     uintptr_t hr_bot_card_index =
 796       uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift;
 797     assert(from_card >= hr_bot_card_index, "Inv");
 798     CardIdx_t card_index = from_card - hr_bot_card_index;
 799     assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion,
 800            "Must be in range.");
 801     return _sparse_table.contains_card(hr_ind, card_index);
 802   }
 803 }
 804 
 805 void
 806 OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
 807   _sparse_table.do_cleanup_work(hrrs_cleanup_task);
 808 }
 809 
 810 // Determines how many threads can add records to an rset in parallel.
 811 // This can be done by either mutator threads together with the
 812 // concurrent refinement threads or GC threads.
 813 uint HeapRegionRemSet::num_par_rem_sets() {
 814   return MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), (uint)ParallelGCThreads);
 815 }
 816 
 817 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
 818                                    HeapRegion* hr)
 819   : _bosa(bosa),
 820     _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true, Monitor::_safepoint_check_never),
 821     _code_roots(), _other_regions(hr, &_m), _iter_state(Unclaimed), _iter_claimed(0) {
 822   reset_for_par_iteration();
 823 }
 824 
 825 void HeapRegionRemSet::setup_remset_size() {
 826   // Setup sparse and fine-grain tables sizes.
 827   // table_size = base * (log(region_size / 1M) + 1)
 828   const int LOG_M = 20;
 829   int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0);
 830   if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) {
 831     G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1);
 832   }
 833   if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) {
 834     G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1);
 835   }
 836   guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity");
 837 }
 838 
 839 bool HeapRegionRemSet::claim_iter() {
 840   if (_iter_state != Unclaimed) return false;
 841   jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed);
 842   return (res == Unclaimed);
 843 }
 844 
 845 void HeapRegionRemSet::set_iter_complete() {
 846   _iter_state = Complete;
 847 }
 848 
 849 bool HeapRegionRemSet::iter_is_complete() {
 850   return _iter_state == Complete;
 851 }
 852 
 853 #ifndef PRODUCT
 854 void HeapRegionRemSet::print() {
 855   HeapRegionRemSetIterator iter(this);
 856   size_t card_index;
 857   while (iter.has_next(card_index)) {
 858     HeapWord* card_start =
 859       G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
 860     gclog_or_tty->print_cr("  Card " PTR_FORMAT, card_start);
 861   }
 862   if (iter.n_yielded() != occupied()) {
 863     gclog_or_tty->print_cr("Yielded disagrees with occupied:");
 864     gclog_or_tty->print_cr("  " SIZE_FORMAT_W(6) " yielded (" SIZE_FORMAT_W(6)
 865                   " coarse, " SIZE_FORMAT_W(6) " fine).",
 866                   iter.n_yielded(),
 867                   iter.n_yielded_coarse(), iter.n_yielded_fine());
 868     gclog_or_tty->print_cr("  " SIZE_FORMAT_W(6) " occ     (" SIZE_FORMAT_W(6)
 869                            " coarse, " SIZE_FORMAT_W(6) " fine).",
 870                   occupied(), occ_coarse(), occ_fine());
 871   }
 872   guarantee(iter.n_yielded() == occupied(),
 873             "We should have yielded all the represented cards.");
 874 }
 875 #endif
 876 
 877 void HeapRegionRemSet::cleanup() {
 878   SparsePRT::cleanup_all();
 879 }
 880 
 881 void HeapRegionRemSet::clear() {
 882   MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
 883   clear_locked();
 884 }
 885 
 886 void HeapRegionRemSet::clear_locked() {
 887   _code_roots.clear();
 888   _other_regions.clear();
 889   assert(occupied_locked() == 0, "Should be clear.");
 890   reset_for_par_iteration();
 891 }
 892 
 893 void HeapRegionRemSet::reset_for_par_iteration() {
 894   _iter_state = Unclaimed;
 895   _iter_claimed = 0;
 896   // It's good to check this to make sure that the two methods are in sync.
 897   assert(verify_ready_for_par_iteration(), "post-condition");
 898 }
 899 
 900 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
 901                              BitMap* region_bm, BitMap* card_bm) {
 902   _other_regions.scrub(ctbs, region_bm, card_bm);
 903 }
 904 
 905 // Code roots support
 906 //
 907 // The code root set is protected by two separate locking schemes
 908 // When at safepoint the per-hrrs lock must be held during modifications
 909 // except when doing a full gc.
 910 // When not at safepoint the CodeCache_lock must be held during modifications.
 911 // When concurrent readers access the contains() function
 912 // (during the evacuation phase) no removals are allowed.
 913 
 914 void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
 915   assert(nm != NULL, "sanity");
 916   // Optimistic unlocked contains-check
 917   if (!_code_roots.contains(nm)) {
 918     MutexLockerEx ml(&_m, Mutex::_no_safepoint_check_flag);
 919     add_strong_code_root_locked(nm);
 920   }
 921 }
 922 
 923 void HeapRegionRemSet::add_strong_code_root_locked(nmethod* nm) {
 924   assert(nm != NULL, "sanity");
 925   _code_roots.add(nm);
 926 }
 927 
 928 void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
 929   assert(nm != NULL, "sanity");
 930   assert_locked_or_safepoint(CodeCache_lock);
 931 
 932   MutexLockerEx ml(CodeCache_lock->owned_by_self() ? NULL : &_m, Mutex::_no_safepoint_check_flag);
 933   _code_roots.remove(nm);
 934 
 935   // Check that there were no duplicates
 936   guarantee(!_code_roots.contains(nm), "duplicate entry found");
 937 }
 938 
 939 void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
 940   _code_roots.nmethods_do(blk);
 941 }
 942 
 943 void HeapRegionRemSet::clean_strong_code_roots(HeapRegion* hr) {
 944   _code_roots.clean(hr);
 945 }
 946 
 947 size_t HeapRegionRemSet::strong_code_roots_mem_size() {
 948   return _code_roots.mem_size();
 949 }
 950 
 951 HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) :
 952   _hrrs(hrrs),
 953   _g1h(G1CollectedHeap::heap()),
 954   _coarse_map(&hrrs->_other_regions._coarse_map),
 955   _bosa(hrrs->_bosa),
 956   _is(Sparse),
 957   // Set these values so that we increment to the first region.
 958   _coarse_cur_region_index(-1),
 959   _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1),
 960   _cur_card_in_prt(HeapRegion::CardsPerRegion),
 961   _fine_cur_prt(NULL),
 962   _n_yielded_coarse(0),
 963   _n_yielded_fine(0),
 964   _n_yielded_sparse(0),
 965   _sparse_iter(&hrrs->_other_regions._sparse_table) {}
 966 
 967 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) {
 968   if (_hrrs->_other_regions._n_coarse_entries == 0) return false;
 969   // Go to the next card.
 970   _coarse_cur_region_cur_card++;
 971   // Was the last the last card in the current region?
 972   if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) {
 973     // Yes: find the next region.  This may leave _coarse_cur_region_index
 974     // Set to the last index, in which case there are no more coarse
 975     // regions.
 976     _coarse_cur_region_index =
 977       (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1);
 978     if ((size_t)_coarse_cur_region_index < _coarse_map->size()) {
 979       _coarse_cur_region_cur_card = 0;
 980       HeapWord* r_bot =
 981         _g1h->region_at((uint) _coarse_cur_region_index)->bottom();
 982       _cur_region_card_offset = _bosa->index_for(r_bot);
 983     } else {
 984       return false;
 985     }
 986   }
 987   // If we didn't return false above, then we can yield a card.
 988   card_index = _cur_region_card_offset + _coarse_cur_region_cur_card;
 989   return true;
 990 }
 991 
 992 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) {
 993   if (fine_has_next()) {
 994     _cur_card_in_prt =
 995       _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
 996   }
 997   if (_cur_card_in_prt == HeapRegion::CardsPerRegion) {
 998     // _fine_cur_prt may still be NULL in case if there are not PRTs at all for
 999     // the remembered set.
1000     if (_fine_cur_prt == NULL || _fine_cur_prt->next() == NULL) {
1001       return false;
1002     }
1003     PerRegionTable* next_prt = _fine_cur_prt->next();
1004     switch_to_prt(next_prt);
1005     _cur_card_in_prt = _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1);
1006   }
1007 
1008   card_index = _cur_region_card_offset + _cur_card_in_prt;
1009   guarantee(_cur_card_in_prt < HeapRegion::CardsPerRegion,
1010             err_msg("Card index "SIZE_FORMAT" must be within the region", _cur_card_in_prt));
1011   return true;
1012 }
1013 
1014 bool HeapRegionRemSetIterator::fine_has_next() {
1015   return _cur_card_in_prt != HeapRegion::CardsPerRegion;
1016 }
1017 
1018 void HeapRegionRemSetIterator::switch_to_prt(PerRegionTable* prt) {
1019   assert(prt != NULL, "Cannot switch to NULL prt");
1020   _fine_cur_prt = prt;
1021 
1022   HeapWord* r_bot = _fine_cur_prt->hr()->bottom();
1023   _cur_region_card_offset = _bosa->index_for(r_bot);
1024 
1025   // The bitmap scan for the PRT always scans from _cur_region_cur_card + 1.
1026   // To avoid special-casing this start case, and not miss the first bitmap
1027   // entry, initialize _cur_region_cur_card with -1 instead of 0.
1028   _cur_card_in_prt = (size_t)-1;
1029 }
1030 
1031 bool HeapRegionRemSetIterator::has_next(size_t& card_index) {
1032   switch (_is) {
1033   case Sparse: {
1034     if (_sparse_iter.has_next(card_index)) {
1035       _n_yielded_sparse++;
1036       return true;
1037     }
1038     // Otherwise, deliberate fall-through
1039     _is = Fine;
1040     PerRegionTable* initial_fine_prt = _hrrs->_other_regions._first_all_fine_prts;
1041     if (initial_fine_prt != NULL) {
1042       switch_to_prt(_hrrs->_other_regions._first_all_fine_prts);
1043     }
1044   }
1045   case Fine:
1046     if (fine_has_next(card_index)) {
1047       _n_yielded_fine++;
1048       return true;
1049     }
1050     // Otherwise, deliberate fall-through
1051     _is = Coarse;
1052   case Coarse:
1053     if (coarse_has_next(card_index)) {
1054       _n_yielded_coarse++;
1055       return true;
1056     }
1057     // Otherwise...
1058     break;
1059   }
1060   assert(ParallelGCThreads > 1 ||
1061          n_yielded() == _hrrs->occupied(),
1062          "Should have yielded all the cards in the rem set "
1063          "(in the non-par case).");
1064   return false;
1065 }
1066 
1067 
1068 
1069 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL;
1070 HeapWord**          HeapRegionRemSet::_recorded_cards = NULL;
1071 HeapRegion**        HeapRegionRemSet::_recorded_regions = NULL;
1072 int                 HeapRegionRemSet::_n_recorded = 0;
1073 
1074 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL;
1075 int*         HeapRegionRemSet::_recorded_event_index = NULL;
1076 int          HeapRegionRemSet::_n_recorded_events = 0;
1077 
1078 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) {
1079   if (_recorded_oops == NULL) {
1080     assert(_n_recorded == 0
1081            && _recorded_cards == NULL
1082            && _recorded_regions == NULL,
1083            "Inv");
1084     _recorded_oops    = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded, mtGC);
1085     _recorded_cards   = NEW_C_HEAP_ARRAY(HeapWord*,          MaxRecorded, mtGC);
1086     _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*,        MaxRecorded, mtGC);
1087   }
1088   if (_n_recorded == MaxRecorded) {
1089     gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded);
1090   } else {
1091     _recorded_cards[_n_recorded] =
1092       (HeapWord*)align_size_down(uintptr_t(f),
1093                                  CardTableModRefBS::card_size);
1094     _recorded_oops[_n_recorded] = f;
1095     _recorded_regions[_n_recorded] = hr;
1096     _n_recorded++;
1097   }
1098 }
1099 
1100 void HeapRegionRemSet::record_event(Event evnt) {
1101   if (!G1RecordHRRSEvents) return;
1102 
1103   if (_recorded_events == NULL) {
1104     assert(_n_recorded_events == 0
1105            && _recorded_event_index == NULL,
1106            "Inv");
1107     _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents, mtGC);
1108     _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents, mtGC);
1109   }
1110   if (_n_recorded_events == MaxRecordedEvents) {
1111     gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents);
1112   } else {
1113     _recorded_events[_n_recorded_events] = evnt;
1114     _recorded_event_index[_n_recorded_events] = _n_recorded;
1115     _n_recorded_events++;
1116   }
1117 }
1118 
1119 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) {
1120   switch (evnt) {
1121   case Event_EvacStart:
1122     str->print("Evac Start");
1123     break;
1124   case Event_EvacEnd:
1125     str->print("Evac End");
1126     break;
1127   case Event_RSUpdateEnd:
1128     str->print("RS Update End");
1129     break;
1130   }
1131 }
1132 
1133 void HeapRegionRemSet::print_recorded() {
1134   int cur_evnt = 0;
1135   Event cur_evnt_kind;
1136   int cur_evnt_ind = 0;
1137   if (_n_recorded_events > 0) {
1138     cur_evnt_kind = _recorded_events[cur_evnt];
1139     cur_evnt_ind = _recorded_event_index[cur_evnt];
1140   }
1141 
1142   for (int i = 0; i < _n_recorded; i++) {
1143     while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) {
1144       gclog_or_tty->print("Event: ");
1145       print_event(gclog_or_tty, cur_evnt_kind);
1146       gclog_or_tty->cr();
1147       cur_evnt++;
1148       if (cur_evnt < MaxRecordedEvents) {
1149         cur_evnt_kind = _recorded_events[cur_evnt];
1150         cur_evnt_ind = _recorded_event_index[cur_evnt];
1151       }
1152     }
1153     gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]"
1154                         " for ref " PTR_FORMAT ".\n",
1155                         _recorded_cards[i], _recorded_regions[i]->bottom(),
1156                         _recorded_oops[i]);
1157   }
1158 }
1159 
1160 void HeapRegionRemSet::reset_for_cleanup_tasks() {
1161   SparsePRT::reset_for_cleanup_tasks();
1162 }
1163 
1164 void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
1165   _other_regions.do_cleanup_work(hrrs_cleanup_task);
1166 }
1167 
1168 void
1169 HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) {
1170   SparsePRT::finish_cleanup_task(hrrs_cleanup_task);
1171 }
1172 
1173 #ifndef PRODUCT
1174 void PerRegionTable::test_fl_mem_size() {
1175   PerRegionTable* dummy = alloc(NULL);
1176 
1177   size_t min_prt_size = sizeof(void*) + dummy->bm()->size_in_words() * HeapWordSize;
1178   assert(dummy->mem_size() > min_prt_size,
1179          err_msg("PerRegionTable memory usage is suspiciously small, only has "SIZE_FORMAT" bytes. "
1180                  "Should be at least "SIZE_FORMAT" bytes.", dummy->mem_size(), min_prt_size));
1181   free(dummy);
1182   guarantee(dummy->mem_size() == fl_mem_size(), "fl_mem_size() does not return the correct element size");
1183   // try to reset the state
1184   _free_list = NULL;
1185   delete dummy;
1186 }
1187 
1188 void HeapRegionRemSet::test_prt() {
1189   PerRegionTable::test_fl_mem_size();
1190 }
1191 
1192 void HeapRegionRemSet::test() {
1193   os::sleep(Thread::current(), (jlong)5000, false);
1194   G1CollectedHeap* g1h = G1CollectedHeap::heap();
1195 
1196   // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same
1197   // hash bucket.
1198   HeapRegion* hr0 = g1h->region_at(0);
1199   HeapRegion* hr1 = g1h->region_at(1);
1200   HeapRegion* hr2 = g1h->region_at(5);
1201   HeapRegion* hr3 = g1h->region_at(6);
1202   HeapRegion* hr4 = g1h->region_at(7);
1203   HeapRegion* hr5 = g1h->region_at(8);
1204 
1205   HeapWord* hr1_start = hr1->bottom();
1206   HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2;
1207   HeapWord* hr1_last = hr1->end() - 1;
1208 
1209   HeapWord* hr2_start = hr2->bottom();
1210   HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2;
1211   HeapWord* hr2_last = hr2->end() - 1;
1212 
1213   HeapWord* hr3_start = hr3->bottom();
1214   HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2;
1215   HeapWord* hr3_last = hr3->end() - 1;
1216 
1217   HeapRegionRemSet* hrrs = hr0->rem_set();
1218 
1219   // Make three references from region 0x101...
1220   hrrs->add_reference((OopOrNarrowOopStar)hr1_start);
1221   hrrs->add_reference((OopOrNarrowOopStar)hr1_mid);
1222   hrrs->add_reference((OopOrNarrowOopStar)hr1_last);
1223 
1224   hrrs->add_reference((OopOrNarrowOopStar)hr2_start);
1225   hrrs->add_reference((OopOrNarrowOopStar)hr2_mid);
1226   hrrs->add_reference((OopOrNarrowOopStar)hr2_last);
1227 
1228   hrrs->add_reference((OopOrNarrowOopStar)hr3_start);
1229   hrrs->add_reference((OopOrNarrowOopStar)hr3_mid);
1230   hrrs->add_reference((OopOrNarrowOopStar)hr3_last);
1231 
1232   // Now cause a coarsening.
1233   hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom());
1234   hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom());
1235 
1236   // Now, does iteration yield these three?
1237   HeapRegionRemSetIterator iter(hrrs);
1238   size_t sum = 0;
1239   size_t card_index;
1240   while (iter.has_next(card_index)) {
1241     HeapWord* card_start =
1242       G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index);
1243     gclog_or_tty->print_cr("  Card " PTR_FORMAT ".", card_start);
1244     sum++;
1245   }
1246   guarantee(sum == 11 - 3 + 2048, "Failure");
1247   guarantee(sum == hrrs->occupied(), "Failure");
1248 }
1249 #endif