| /* |
| * Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "gc/g1/heapRegion.hpp" |
| #include "gc/g1/heapRegionBounds.inline.hpp" |
| #include "gc/g1/heapRegionRemSet.hpp" |
| #include "gc/g1/sparsePRT.hpp" |
| #include "gc/shared/cardTableModRefBS.hpp" |
| #include "gc/shared/space.inline.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/mutexLocker.hpp" |
| |
| // Check that the size of the SparsePRTEntry is evenly divisible by the maximum |
| // member type to avoid SIGBUS when accessing them. |
| STATIC_ASSERT(sizeof(SparsePRTEntry) % sizeof(int) == 0); |
| |
| void SparsePRTEntry::init(RegionIdx_t region_ind) { |
| // Check that the card array element type can represent all cards in the region. |
| // Choose a large SparsePRTEntry::card_elem_t (e.g. CardIdx_t) if required. |
| assert(((size_t)1 << (sizeof(SparsePRTEntry::card_elem_t) * BitsPerByte)) * |
| G1SATBCardTableModRefBS::card_size >= HeapRegionBounds::max_size(), "precondition"); |
| assert(G1RSetSparseRegionEntries > 0, "precondition"); |
| _region_ind = region_ind; |
| _next_index = RSHashTable::NullEntry; |
| _next_null = 0; |
| } |
| |
| bool SparsePRTEntry::contains_card(CardIdx_t card_index) const { |
| for (int i = 0; i < num_valid_cards(); i++) { |
| if (card(i) == card_index) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| SparsePRTEntry::AddCardResult SparsePRTEntry::add_card(CardIdx_t card_index) { |
| for (int i = 0; i < num_valid_cards(); i++) { |
| if (card(i) == card_index) { |
| return found; |
| } |
| } |
| if (num_valid_cards() < cards_num() - 1) { |
| _cards[_next_null] = (card_elem_t)card_index; |
| _next_null++; |
| return added; |
| } |
| // Otherwise, we're full. |
| return overflow; |
| } |
| |
| void SparsePRTEntry::copy_cards(card_elem_t* cards) const { |
| memcpy(cards, _cards, cards_num() * sizeof(card_elem_t)); |
| } |
| |
| void SparsePRTEntry::copy_cards(SparsePRTEntry* e) const { |
| copy_cards(e->_cards); |
| assert(_next_null >= 0, "invariant"); |
| assert(_next_null <= cards_num(), "invariant"); |
| e->_next_null = _next_null; |
| } |
| |
| // ---------------------------------------------------------------------- |
| |
| float RSHashTable::TableOccupancyFactor = 0.5f; |
| |
| RSHashTable::RSHashTable(size_t capacity) : |
| _capacity(capacity), _capacity_mask(capacity-1), |
| _occupied_entries(0), _occupied_cards(0), |
| _entries(NULL), |
| _buckets(NEW_C_HEAP_ARRAY(int, capacity, mtGC)), |
| _free_list(NullEntry), _free_region(0) |
| { |
| _num_entries = (capacity * TableOccupancyFactor) + 1; |
| _entries = (SparsePRTEntry*)NEW_C_HEAP_ARRAY(char, _num_entries * SparsePRTEntry::size(), mtGC); |
| 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((void*)_entries, NullEntry, _num_entries * SparsePRTEntry::size()); |
| memset((void*)_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++; |
| assert(e->num_valid_cards() > 0, "Postcondition"); |
| return res != SparsePRTEntry::overflow; |
| } |
| |
| SparsePRTEntry* RSHashTable::get_entry(RegionIdx_t region_ind) const { |
| 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_create(RegionIdx_t region_ind) { |
| SparsePRTEntry* res = get_entry(region_ind); |
| if (res == NULL) { |
| int new_ind = alloc_entry(); |
| 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 < _num_entries) { |
| 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() { |
| while (_bl_ind != RSHashTable::NullEntry) { |
| SparsePRTEntry* sparse_entry = _rsht->entry(_bl_ind); |
| if (sparse_entry->num_valid_cards() > 0) { |
| return sparse_entry->card(0); |
| } else { |
| _bl_ind = sparse_entry->next_index(); |
| } |
| } |
| // Otherwise, none found: |
| return NoCardFound; |
| } |
| |
| 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++; |
| if (_bl_ind >= 0) { |
| SparsePRTEntry* e = _rsht->entry(_bl_ind); |
| if (_card_ind < e->num_valid_cards()) { |
| CardIdx_t ci = e->card(_card_ind); |
| 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(); |
| CardIdx_t ci = find_first_card_in_list(); |
| if (ci != NoCardFound) { |
| 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]; |
| CardIdx_t ci = find_first_card_in_list(); |
| if (ci != NoCardFound) { |
| 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 = get_entry(region_index); |
| return (e != NULL && e->contains_card(card_index)); |
| } |
| |
| size_t RSHashTable::mem_size() const { |
| return sizeof(RSHashTable) + |
| _num_entries * (SparsePRTEntry::size() + sizeof(int)); |
| } |
| |
| // ---------------------------------------------------------------------- |
| |
| SparsePRT* volatile 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::reset_for_cleanup_tasks() { |
| _head_expanded_list = NULL; |
| } |
| |
| void SparsePRT::do_cleanup_work(SparsePRTCleanupTask* sprt_cleanup_task) { |
| if (should_be_on_expanded_list()) { |
| sprt_cleanup_task->add(this); |
| } |
| } |
| |
| void SparsePRT::finish_cleanup_task(SparsePRTCleanupTask* sprt_cleanup_task) { |
| assert(ParGCRareEvent_lock->owned_by_self(), "pre-condition"); |
| SparsePRT* head = sprt_cleanup_task->head(); |
| SparsePRT* tail = sprt_cleanup_task->tail(); |
| if (head != NULL) { |
| assert(tail != NULL, "if head is not NULL, so should tail"); |
| |
| tail->set_next_expanded(_head_expanded_list); |
| _head_expanded_list = head; |
| } else { |
| assert(tail == NULL, "if head is NULL, so should tail"); |
| } |
| } |
| |
| bool SparsePRT::should_be_on_expanded_list() { |
| if (_expanded) { |
| assert(_cur != _next, "if _expanded is true, cur should be != _next"); |
| } else { |
| assert(_cur == _next, "if _expanded is false, cur should be == _next"); |
| } |
| return expanded(); |
| } |
| |
| 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(SparsePRT) + _next->mem_size(); |
| } |
| |
| bool SparsePRT::add_card(RegionIdx_t region_id, CardIdx_t card_index) { |
| if (_next->should_expand()) { |
| expand(); |
| } |
| return _next->add_card(region_id, card_index); |
| } |
| |
| 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; |
| _expanded = false; |
| } |
| |
| 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); |
| for (size_t i = 0; i < last->num_entries(); i++) { |
| SparsePRTEntry* e = last->entry((int)i); |
| if (e->valid_entry()) { |
| _next->add_entry(e); |
| } |
| } |
| if (last != _cur) { |
| delete last; |
| } |
| add_to_expanded_list(this); |
| } |
| |
| void SparsePRTCleanupTask::add(SparsePRT* sprt) { |
| assert(sprt->should_be_on_expanded_list(), "pre-condition"); |
| |
| sprt->set_next_expanded(NULL); |
| if (_tail != NULL) { |
| _tail->set_next_expanded(sprt); |
| } else { |
| _head = sprt; |
| } |
| _tail = sprt; |
| } |