jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/sparsePRT.cpp@72a161e62cc4 (annotated)

src/share/vm/gc_implementation/g1/sparsePRT.cpp@72a161e62cc4 (annotated)

src/share/vm/gc_implementation/g1/sparsePRT.cpp

Sat, 16 Oct 2010 17:12:19 -0400

author: tonyp
date: Sat, 16 Oct 2010 17:12:19 -0400
changeset 2241: 72a161e62cc4
parent 2239: 9f4848ebbabd
child 2314: f95d63e2154a
permissions: -rw-r--r--

6991377: G1: race between concurrent refinement and humongous object allocation
Summary: There is a race between the concurrent refinement threads and the humongous object allocation that can cause the concurrent refinement threads to corrupt the part of the BOT that it is being initialized by the humongous object allocation operation. The solution is to do the humongous object allocation in careful steps to ensure that the concurrent refinement threads always have a consistent view over the BOT, region contents, and top. The fix includes some very minor tidying up in sparsePRT.
Reviewed-by: jcoomes, johnc, ysr

 /*
  * Copyright (c) 2001, 2009, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "incls/_precompiled.incl"
 #include "incls/_sparsePRT.cpp.incl"
 #define SPARSE_PRT_VERBOSE 0
 #define UNROLL_CARD_LOOPS  1
 void SparsePRT::init_iterator(SparsePRTIter* sprt_iter) {
     sprt_iter->init(this);
 }
 void SparsePRTEntry::init(RegionIdx_t region_ind) {
   _region_ind = region_ind;
   _next_index = NullEntry;
 #if UNROLL_CARD_LOOPS
   assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry");
   for (int i = 0; i < cards_num(); i += UnrollFactor) {
     _cards[i] = NullEntry;
     _cards[i + 1] = NullEntry;
     _cards[i + 2] = NullEntry;
     _cards[i + 3] = NullEntry;
   }
 #else
   for (int i = 0; i < cards_num(); i++)
     _cards[i] = NullEntry;
 #endif
 }
 bool SparsePRTEntry::contains_card(CardIdx_t card_index) const {
 #if UNROLL_CARD_LOOPS
   assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry");
   for (int i = 0; i < cards_num(); i += UnrollFactor) {
     if (_cards[i] == card_index ||
         _cards[i + 1] == card_index ||
         _cards[i + 2] == card_index ||
         _cards[i + 3] == card_index) return true;
   }
 #else
   for (int i = 0; i < cards_num(); i++) {
     if (_cards[i] == card_index) return true;
   }
 #endif
   // Otherwise, we're full.
   return false;
 }
 int SparsePRTEntry::num_valid_cards() const {
   int sum = 0;
 #if UNROLL_CARD_LOOPS
   assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry");
   for (int i = 0; i < cards_num(); i += UnrollFactor) {
     sum += (_cards[i] != NullEntry);
     sum += (_cards[i + 1] != NullEntry);
     sum += (_cards[i + 2] != NullEntry);
     sum += (_cards[i + 3] != NullEntry);
   }
 #else
   for (int i = 0; i < cards_num(); i++) {
     sum += (_cards[i] != NullEntry);
   }
 #endif
   // Otherwise, we're full.
   return sum;
 }
 SparsePRTEntry::AddCardResult SparsePRTEntry::add_card(CardIdx_t card_index) {
 #if UNROLL_CARD_LOOPS
   assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry");
   CardIdx_t c;
   for (int i = 0; i < cards_num(); i += UnrollFactor) {
     c = _cards[i];
     if (c == card_index) return found;
     if (c == NullEntry) { _cards[i] = card_index; return added; }
     c = _cards[i + 1];
     if (c == card_index) return found;
     if (c == NullEntry) { _cards[i + 1] = card_index; return added; }
     c = _cards[i + 2];
     if (c == card_index) return found;
     if (c == NullEntry) { _cards[i + 2] = card_index; return added; }
     c = _cards[i + 3];
     if (c == card_index) return found;
     if (c == NullEntry) { _cards[i + 3] = card_index; return added; }
   }
 #else
   for (int i = 0; i < cards_num(); i++) {
     CardIdx_t c = _cards[i];
     if (c == card_index) return found;
     if (c == NullEntry) { _cards[i] = card_index; return added; }
   }
 #endif
   // Otherwise, we're full.
   return overflow;
 }
 void SparsePRTEntry::copy_cards(CardIdx_t* cards) const {
 #if UNROLL_CARD_LOOPS
   assert((cards_num() & (UnrollFactor - 1)) == 0, "Invalid number of cards in the entry");
   for (int i = 0; i < cards_num(); i += UnrollFactor) {
     cards[i] = _cards[i];
     cards[i + 1] = _cards[i + 1];
     cards[i + 2] = _cards[i + 2];
     cards[i + 3] = _cards[i + 3];
   }
 #else
   for (int i = 0; i < cards_num(); i++) {
     cards[i] = _cards[i];
   }
 #endif
 }
 void SparsePRTEntry::copy_cards(SparsePRTEntry* e) const {
   copy_cards(&e->_cards[0]);
 }
 // ----------------------------------------------------------------------
 RSHashTable::RSHashTable(size_t capacity) :
   _capacity(capacity), _capacity_mask(capacity-1),
   _occupied_entries(0), _occupied_cards(0),
   _entries((SparsePRTEntry*)NEW_C_HEAP_ARRAY(char, SparsePRTEntry::size() * capacity)),
   _buckets(NEW_C_HEAP_ARRAY(int, capacity)),
   _free_list(NullEntry), _free_region(0)
 {
   clear();
 }
 RSHashTable::~RSHashTable() {
   if (_entries != NULL) {
     FREE_C_HEAP_ARRAY(SparsePRTEntry, _entries);
     _entries = NULL;
   }
   if (_buckets != NULL) {
     FREE_C_HEAP_ARRAY(int, _buckets);
     _buckets = NULL;
   }
 }
 void RSHashTable::clear() {
   _occupied_entries = 0;
   _occupied_cards = 0;
   guarantee(_entries != NULL, "INV");
   guarantee(_buckets != NULL, "INV");
   guarantee(_capacity <= ((size_t)1 << (sizeof(int)*BitsPerByte-1)) - 1,
                 "_capacity too large");
   // This will put -1 == NullEntry in the key field of all entries.
   memset(_entries, NullEntry, _capacity * SparsePRTEntry::size());
   memset(_buckets, NullEntry, _capacity * sizeof(int));
   _free_list = NullEntry;
   _free_region = 0;
 }
 bool RSHashTable::add_card(RegionIdx_t region_ind, CardIdx_t card_index) {
   SparsePRTEntry* e = entry_for_region_ind_create(region_ind);
   assert(e != NULL && e->r_ind() == region_ind,
          "Postcondition of call above.");
   SparsePRTEntry::AddCardResult res = e->add_card(card_index);
   if (res == SparsePRTEntry::added) _occupied_cards++;
 #if SPARSE_PRT_VERBOSE
   gclog_or_tty->print_cr("       after add_card[%d]: valid-cards = %d.",
                          pointer_delta(e, _entries, SparsePRTEntry::size()),
                          e->num_valid_cards());
 #endif
   assert(e->num_valid_cards() > 0, "Postcondition");
   return res != SparsePRTEntry::overflow;
 }
 bool RSHashTable::get_cards(RegionIdx_t region_ind, CardIdx_t* cards) {
   int ind = (int) (region_ind & capacity_mask());
   int cur_ind = _buckets[ind];
   SparsePRTEntry* cur;
   while (cur_ind != NullEntry &&
          (cur = entry(cur_ind))->r_ind() != region_ind) {
     cur_ind = cur->next_index();
   }
   if (cur_ind == NullEntry) return false;
   // Otherwise...
   assert(cur->r_ind() == region_ind, "Postcondition of loop + test above.");
   assert(cur->num_valid_cards() > 0, "Inv");
   cur->copy_cards(cards);
   return true;
 }
 SparsePRTEntry* RSHashTable::get_entry(RegionIdx_t region_ind) {
   int ind = (int) (region_ind & capacity_mask());
   int cur_ind = _buckets[ind];
   SparsePRTEntry* cur;
   while (cur_ind != NullEntry &&
          (cur = entry(cur_ind))->r_ind() != region_ind) {
     cur_ind = cur->next_index();
   }
   if (cur_ind == NullEntry) return NULL;
   // Otherwise...
   assert(cur->r_ind() == region_ind, "Postcondition of loop + test above.");
   assert(cur->num_valid_cards() > 0, "Inv");
   return cur;
 }
 bool RSHashTable::delete_entry(RegionIdx_t region_ind) {
   int ind = (int) (region_ind & capacity_mask());
   int* prev_loc = &_buckets[ind];
   int cur_ind = *prev_loc;
   SparsePRTEntry* cur;
   while (cur_ind != NullEntry &&
          (cur = entry(cur_ind))->r_ind() != region_ind) {
     prev_loc = cur->next_index_addr();
     cur_ind = *prev_loc;
   }
   if (cur_ind == NullEntry) return false;
   // Otherwise, splice out "cur".
   *prev_loc = cur->next_index();
   _occupied_cards -= cur->num_valid_cards();
   free_entry(cur_ind);
   _occupied_entries--;
   return true;
 }
 SparsePRTEntry*
 RSHashTable::entry_for_region_ind(RegionIdx_t region_ind) const {
   assert(occupied_entries() < capacity(), "Precondition");
   int ind = (int) (region_ind & capacity_mask());
   int cur_ind = _buckets[ind];
   SparsePRTEntry* cur;
   while (cur_ind != NullEntry &&
          (cur = entry(cur_ind))->r_ind() != region_ind) {
     cur_ind = cur->next_index();
   }
   if (cur_ind != NullEntry) {
     assert(cur->r_ind() == region_ind, "Loop postcondition + test");
     return cur;
   } else {
     return NULL;
   }
 }
 SparsePRTEntry*
 RSHashTable::entry_for_region_ind_create(RegionIdx_t region_ind) {
   SparsePRTEntry* res = entry_for_region_ind(region_ind);
   if (res == NULL) {
     int new_ind = alloc_entry();
     assert(0 <= new_ind && (size_t)new_ind < capacity(), "There should be room.");
     res = entry(new_ind);
     res->init(region_ind);
     // Insert at front.
     int ind = (int) (region_ind & capacity_mask());
     res->set_next_index(_buckets[ind]);
     _buckets[ind] = new_ind;
     _occupied_entries++;
   }
   return res;
 }
 int RSHashTable::alloc_entry() {
   int res;
   if (_free_list != NullEntry) {
     res = _free_list;
     _free_list = entry(res)->next_index();
     return res;
   } else if ((size_t) _free_region+1 < capacity()) {
     res = _free_region;
     _free_region++;
     return res;
   } else {
     return NullEntry;
   }
 }
 void RSHashTable::free_entry(int fi) {
   entry(fi)->set_next_index(_free_list);
   _free_list = fi;
 }
 void RSHashTable::add_entry(SparsePRTEntry* e) {
   assert(e->num_valid_cards() > 0, "Precondition.");
   SparsePRTEntry* e2 = entry_for_region_ind_create(e->r_ind());
   e->copy_cards(e2);
   _occupied_cards += e2->num_valid_cards();
   assert(e2->num_valid_cards() > 0, "Postcondition.");
 }
 CardIdx_t RSHashTableIter::find_first_card_in_list() {
   CardIdx_t res;
   while (_bl_ind != RSHashTable::NullEntry) {
     res = _rsht->entry(_bl_ind)->card(0);
     if (res != SparsePRTEntry::NullEntry) {
       return res;
     } else {
       _bl_ind = _rsht->entry(_bl_ind)->next_index();
     }
   }
   // Otherwise, none found:
   return SparsePRTEntry::NullEntry;
 }
 size_t RSHashTableIter::compute_card_ind(CardIdx_t ci) {
   return (_rsht->entry(_bl_ind)->r_ind() * HeapRegion::CardsPerRegion) + ci;
 }
 bool RSHashTableIter::has_next(size_t& card_index) {
   _card_ind++;
   CardIdx_t ci;
   if (_card_ind < SparsePRTEntry::cards_num() &&
       ((ci = _rsht->entry(_bl_ind)->card(_card_ind)) !=
        SparsePRTEntry::NullEntry)) {
     card_index = compute_card_ind(ci);
     return true;
   }
   // Otherwise, must find the next valid entry.
   _card_ind = 0;
   if (_bl_ind != RSHashTable::NullEntry) {
       _bl_ind = _rsht->entry(_bl_ind)->next_index();
       ci = find_first_card_in_list();
       if (ci != SparsePRTEntry::NullEntry) {
         card_index = compute_card_ind(ci);
         return true;
       }
   }
   // If we didn't return above, must go to the next non-null table index.
   _tbl_ind++;
   while ((size_t)_tbl_ind < _rsht->capacity()) {
     _bl_ind = _rsht->_buckets[_tbl_ind];
     ci = find_first_card_in_list();
     if (ci != SparsePRTEntry::NullEntry) {
       card_index = compute_card_ind(ci);
       return true;
     }
     // Otherwise, try next entry.
     _tbl_ind++;
   }
   // Otherwise, there were no entry.
   return false;
 }
 bool RSHashTable::contains_card(RegionIdx_t region_index, CardIdx_t card_index) const {
   SparsePRTEntry* e = entry_for_region_ind(region_index);
   return (e != NULL && e->contains_card(card_index));
 }
 size_t RSHashTable::mem_size() const {
   return sizeof(this) +
     capacity() * (SparsePRTEntry::size() + sizeof(int));
 }
 // ----------------------------------------------------------------------
 SparsePRT* SparsePRT::_head_expanded_list = NULL;
 void SparsePRT::add_to_expanded_list(SparsePRT* sprt) {
   // We could expand multiple times in a pause -- only put on list once.
   if (sprt->expanded()) return;
   sprt->set_expanded(true);
   SparsePRT* hd = _head_expanded_list;
   while (true) {
     sprt->_next_expanded = hd;
     SparsePRT* res =
       (SparsePRT*)
       Atomic::cmpxchg_ptr(sprt, &_head_expanded_list, hd);
     if (res == hd) return;
     else hd = res;
   }
 }
 SparsePRT* SparsePRT::get_from_expanded_list() {
   SparsePRT* hd = _head_expanded_list;
   while (hd != NULL) {
     SparsePRT* next = hd->next_expanded();
     SparsePRT* res =
       (SparsePRT*)
       Atomic::cmpxchg_ptr(next, &_head_expanded_list, hd);
     if (res == hd) {
       hd->set_next_expanded(NULL);
       return hd;
     } else {
       hd = res;
     }
   }
   return NULL;
 }
 void SparsePRT::cleanup_all() {
   // First clean up all expanded tables so they agree on next and cur.
   SparsePRT* sprt = get_from_expanded_list();
   while (sprt != NULL) {
     sprt->cleanup();
     sprt = get_from_expanded_list();
   }
 }
 SparsePRT::SparsePRT(HeapRegion* hr) :
   _hr(hr), _expanded(false), _next_expanded(NULL)
 {
   _cur = new RSHashTable(InitialCapacity);
   _next = _cur;
 }
 SparsePRT::~SparsePRT() {
   assert(_next != NULL && _cur != NULL, "Inv");
   if (_cur != _next) { delete _cur; }
   delete _next;
 }
 size_t SparsePRT::mem_size() const {
   // We ignore "_cur" here, because it either = _next, or else it is
   // on the deleted list.
   return sizeof(this) + _next->mem_size();
 }
 bool SparsePRT::add_card(RegionIdx_t region_id, CardIdx_t card_index) {
 #if SPARSE_PRT_VERBOSE
   gclog_or_tty->print_cr("  Adding card %d from region %d to region %d sparse.",
                 card_index, region_id, _hr->hrs_index());
 #endif
   if (_next->occupied_entries() * 2 > _next->capacity()) {
     expand();
   }
   return _next->add_card(region_id, card_index);
 }
 bool SparsePRT::get_cards(RegionIdx_t region_id, CardIdx_t* cards) {
   return _next->get_cards(region_id, cards);
 }
 SparsePRTEntry* SparsePRT::get_entry(RegionIdx_t region_id) {
   return _next->get_entry(region_id);
 }
 bool SparsePRT::delete_entry(RegionIdx_t region_id) {
   return _next->delete_entry(region_id);
 }
 void SparsePRT::clear() {
   // If they differ, _next is bigger then cur, so next has no chance of
   // being the initial size.
   if (_next != _cur) {
     delete _next;
   }
   if (_cur->capacity() != InitialCapacity) {
     delete _cur;
     _cur = new RSHashTable(InitialCapacity);
   } else {
     _cur->clear();
   }
   _next = _cur;
 }
 void SparsePRT::cleanup() {
   // Make sure that the current and next tables agree.
   if (_cur != _next) {
     delete _cur;
   }
   _cur = _next;
   set_expanded(false);
 }
 void SparsePRT::expand() {
   RSHashTable* last = _next;
   _next = new RSHashTable(last->capacity() * 2);
 #if SPARSE_PRT_VERBOSE
   gclog_or_tty->print_cr("  Expanded sparse table for %d to %d.",
                 _hr->hrs_index(), _next->capacity());
 #endif
   for (size_t i = 0; i < last->capacity(); i++) {
     SparsePRTEntry* e = last->entry((int)i);
     if (e->valid_entry()) {
 #if SPARSE_PRT_VERBOSE
       gclog_or_tty->print_cr("    During expansion, transferred entry for %d.",
                     e->r_ind());
 #endif
       _next->add_entry(e);
     }
   }
   if (last != _cur) {
     delete last;
   }
   add_to_expanded_list(this);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/sparsePRT.cpp@72a161e62cc4 (annotated)

src/share/vm/gc_implementation/g1/sparsePRT.cpp