| /* |
| * Copyright (c) 2001, 2016, 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/concurrentG1Refine.hpp" |
| #include "gc/g1/g1BlockOffsetTable.inline.hpp" |
| #include "gc/g1/g1CollectedHeap.inline.hpp" |
| #include "gc/g1/heapRegionManager.inline.hpp" |
| #include "gc/g1/heapRegionRemSet.hpp" |
| #include "gc/shared/space.inline.hpp" |
| #include "memory/allocation.hpp" |
| #include "memory/padded.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/atomic.inline.hpp" |
| #include "utilities/bitMap.inline.hpp" |
| #include "utilities/globalDefinitions.hpp" |
| #include "utilities/growableArray.hpp" |
| |
| class PerRegionTable: public CHeapObj<mtGC> { |
| friend class OtherRegionsTable; |
| friend class HeapRegionRemSetIterator; |
| |
| HeapRegion* _hr; |
| BitMap _bm; |
| jint _occupied; |
| |
| // next pointer for free/allocated 'all' list |
| PerRegionTable* _next; |
| |
| // prev pointer for the allocated 'all' list |
| PerRegionTable* _prev; |
| |
| // next pointer in collision list |
| PerRegionTable * _collision_list_next; |
| |
| // Global free list of PRTs |
| static PerRegionTable* _free_list; |
| |
| protected: |
| // We need access in order to union things into the base table. |
| BitMap* bm() { return &_bm; } |
| |
| void recount_occupied() { |
| _occupied = (jint) bm()->count_one_bits(); |
| } |
| |
| PerRegionTable(HeapRegion* hr) : |
| _hr(hr), |
| _occupied(0), |
| _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */), |
| _collision_list_next(NULL), _next(NULL), _prev(NULL) |
| {} |
| |
| void add_card_work(CardIdx_t from_card, bool par) { |
| if (!_bm.at(from_card)) { |
| if (par) { |
| if (_bm.par_at_put(from_card, 1)) { |
| Atomic::inc(&_occupied); |
| } |
| } else { |
| _bm.at_put(from_card, 1); |
| _occupied++; |
| } |
| } |
| } |
| |
| void add_reference_work(OopOrNarrowOopStar from, bool par) { |
| // Must make this robust in case "from" is not in "_hr", because of |
| // concurrency. |
| |
| HeapRegion* loc_hr = hr(); |
| // If the test below fails, then this table was reused concurrently |
| // with this operation. This is OK, since the old table was coarsened, |
| // and adding a bit to the new table is never incorrect. |
| // If the table used to belong to a continues humongous region and is |
| // now reused for the corresponding start humongous region, we need to |
| // make sure that we detect this. Thus, we call is_in_reserved_raw() |
| // instead of just is_in_reserved() here. |
| if (loc_hr->is_in_reserved(from)) { |
| size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom()); |
| CardIdx_t from_card = (CardIdx_t) |
| hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize); |
| |
| assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion, |
| "Must be in range."); |
| add_card_work(from_card, par); |
| } |
| } |
| |
| public: |
| |
| HeapRegion* hr() const { |
| return (HeapRegion*) OrderAccess::load_ptr_acquire(&_hr); |
| } |
| |
| jint occupied() const { |
| // Overkill, but if we ever need it... |
| // guarantee(_occupied == _bm.count_one_bits(), "Check"); |
| return _occupied; |
| } |
| |
| void init(HeapRegion* hr, bool clear_links_to_all_list) { |
| if (clear_links_to_all_list) { |
| set_next(NULL); |
| set_prev(NULL); |
| } |
| _collision_list_next = NULL; |
| _occupied = 0; |
| _bm.clear(); |
| // Make sure that the bitmap clearing above has been finished before publishing |
| // this PRT to concurrent threads. |
| OrderAccess::release_store_ptr(&_hr, hr); |
| } |
| |
| void add_reference(OopOrNarrowOopStar from) { |
| add_reference_work(from, /*parallel*/ true); |
| } |
| |
| void seq_add_reference(OopOrNarrowOopStar from) { |
| add_reference_work(from, /*parallel*/ false); |
| } |
| |
| void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) { |
| HeapWord* hr_bot = hr()->bottom(); |
| size_t hr_first_card_index = ctbs->index_for(hr_bot); |
| bm()->set_intersection_at_offset(*card_bm, hr_first_card_index); |
| recount_occupied(); |
| } |
| |
| void add_card(CardIdx_t from_card_index) { |
| add_card_work(from_card_index, /*parallel*/ true); |
| } |
| |
| void seq_add_card(CardIdx_t from_card_index) { |
| add_card_work(from_card_index, /*parallel*/ false); |
| } |
| |
| // (Destructively) union the bitmap of the current table into the given |
| // bitmap (which is assumed to be of the same size.) |
| void union_bitmap_into(BitMap* bm) { |
| bm->set_union(_bm); |
| } |
| |
| // Mem size in bytes. |
| size_t mem_size() const { |
| return sizeof(PerRegionTable) + _bm.size_in_words() * HeapWordSize; |
| } |
| |
| // Requires "from" to be in "hr()". |
| bool contains_reference(OopOrNarrowOopStar from) const { |
| assert(hr()->is_in_reserved(from), "Precondition."); |
| size_t card_ind = pointer_delta(from, hr()->bottom(), |
| CardTableModRefBS::card_size); |
| return _bm.at(card_ind); |
| } |
| |
| // Bulk-free the PRTs from prt to last, assumes that they are |
| // linked together using their _next field. |
| static void bulk_free(PerRegionTable* prt, PerRegionTable* last) { |
| while (true) { |
| PerRegionTable* fl = _free_list; |
| last->set_next(fl); |
| PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl); |
| if (res == fl) { |
| return; |
| } |
| } |
| ShouldNotReachHere(); |
| } |
| |
| static void free(PerRegionTable* prt) { |
| bulk_free(prt, prt); |
| } |
| |
| // Returns an initialized PerRegionTable instance. |
| static PerRegionTable* alloc(HeapRegion* hr) { |
| PerRegionTable* fl = _free_list; |
| while (fl != NULL) { |
| PerRegionTable* nxt = fl->next(); |
| PerRegionTable* res = |
| (PerRegionTable*) |
| Atomic::cmpxchg_ptr(nxt, &_free_list, fl); |
| if (res == fl) { |
| fl->init(hr, true); |
| return fl; |
| } else { |
| fl = _free_list; |
| } |
| } |
| assert(fl == NULL, "Loop condition."); |
| return new PerRegionTable(hr); |
| } |
| |
| PerRegionTable* next() const { return _next; } |
| void set_next(PerRegionTable* next) { _next = next; } |
| PerRegionTable* prev() const { return _prev; } |
| void set_prev(PerRegionTable* prev) { _prev = prev; } |
| |
| // Accessor and Modification routines for the pointer for the |
| // singly linked collision list that links the PRTs within the |
| // OtherRegionsTable::_fine_grain_regions hash table. |
| // |
| // It might be useful to also make the collision list doubly linked |
| // to avoid iteration over the collisions list during scrubbing/deletion. |
| // OTOH there might not be many collisions. |
| |
| PerRegionTable* collision_list_next() const { |
| return _collision_list_next; |
| } |
| |
| void set_collision_list_next(PerRegionTable* next) { |
| _collision_list_next = next; |
| } |
| |
| PerRegionTable** collision_list_next_addr() { |
| return &_collision_list_next; |
| } |
| |
| static size_t fl_mem_size() { |
| PerRegionTable* cur = _free_list; |
| size_t res = 0; |
| while (cur != NULL) { |
| res += cur->mem_size(); |
| cur = cur->next(); |
| } |
| return res; |
| } |
| |
| static void test_fl_mem_size(); |
| }; |
| |
| PerRegionTable* PerRegionTable::_free_list = NULL; |
| |
| size_t OtherRegionsTable::_max_fine_entries = 0; |
| size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0; |
| size_t OtherRegionsTable::_fine_eviction_stride = 0; |
| size_t OtherRegionsTable::_fine_eviction_sample_size = 0; |
| |
| OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) : |
| _g1h(G1CollectedHeap::heap()), |
| _hr(hr), _m(m), |
| _coarse_map(G1CollectedHeap::heap()->max_regions(), |
| false /* in-resource-area */), |
| _fine_grain_regions(NULL), |
| _first_all_fine_prts(NULL), _last_all_fine_prts(NULL), |
| _n_fine_entries(0), _n_coarse_entries(0), |
| _fine_eviction_start(0), |
| _sparse_table(hr) |
| { |
| typedef PerRegionTable* PerRegionTablePtr; |
| |
| if (_max_fine_entries == 0) { |
| assert(_mod_max_fine_entries_mask == 0, "Both or none."); |
| size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries); |
| _max_fine_entries = (size_t)1 << max_entries_log; |
| _mod_max_fine_entries_mask = _max_fine_entries - 1; |
| |
| assert(_fine_eviction_sample_size == 0 |
| && _fine_eviction_stride == 0, "All init at same time."); |
| _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log); |
| _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size; |
| } |
| |
| _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries, |
| mtGC, CURRENT_PC, AllocFailStrategy::RETURN_NULL); |
| |
| if (_fine_grain_regions == NULL) { |
| vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR, |
| "Failed to allocate _fine_grain_entries."); |
| } |
| |
| for (size_t i = 0; i < _max_fine_entries; i++) { |
| _fine_grain_regions[i] = NULL; |
| } |
| } |
| |
| void OtherRegionsTable::link_to_all(PerRegionTable* prt) { |
| // We always append to the beginning of the list for convenience; |
| // the order of entries in this list does not matter. |
| if (_first_all_fine_prts != NULL) { |
| assert(_first_all_fine_prts->prev() == NULL, "invariant"); |
| _first_all_fine_prts->set_prev(prt); |
| prt->set_next(_first_all_fine_prts); |
| } else { |
| // this is the first element we insert. Adjust the "last" pointer |
| _last_all_fine_prts = prt; |
| assert(prt->next() == NULL, "just checking"); |
| } |
| // the new element is always the first element without a predecessor |
| prt->set_prev(NULL); |
| _first_all_fine_prts = prt; |
| |
| assert(prt->prev() == NULL, "just checking"); |
| assert(_first_all_fine_prts == prt, "just checking"); |
| assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) || |
| (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL), |
| "just checking"); |
| assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL, |
| "just checking"); |
| assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL, |
| "just checking"); |
| } |
| |
| void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) { |
| if (prt->prev() != NULL) { |
| assert(_first_all_fine_prts != prt, "just checking"); |
| prt->prev()->set_next(prt->next()); |
| // removing the last element in the list? |
| if (_last_all_fine_prts == prt) { |
| _last_all_fine_prts = prt->prev(); |
| } |
| } else { |
| assert(_first_all_fine_prts == prt, "just checking"); |
| _first_all_fine_prts = prt->next(); |
| // list is empty now? |
| if (_first_all_fine_prts == NULL) { |
| _last_all_fine_prts = NULL; |
| } |
| } |
| |
| if (prt->next() != NULL) { |
| prt->next()->set_prev(prt->prev()); |
| } |
| |
| prt->set_next(NULL); |
| prt->set_prev(NULL); |
| |
| assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) || |
| (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL), |
| "just checking"); |
| assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL, |
| "just checking"); |
| assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL, |
| "just checking"); |
| } |
| |
| void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, uint tid) { |
| uint cur_hrm_ind = _hr->hrm_index(); |
| |
| int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift); |
| |
| if (G1FromCardCache::contains_or_replace(tid, cur_hrm_ind, from_card)) { |
| assert(contains_reference(from), "We just found " PTR_FORMAT " in the FromCardCache", p2i(from)); |
| return; |
| } |
| |
| // Note that this may be a continued H region. |
| HeapRegion* from_hr = _g1h->heap_region_containing(from); |
| RegionIdx_t from_hrm_ind = (RegionIdx_t) from_hr->hrm_index(); |
| |
| // If the region is already coarsened, return. |
| if (_coarse_map.at(from_hrm_ind)) { |
| assert(contains_reference(from), "We just found " PTR_FORMAT " in the Coarse table", p2i(from)); |
| return; |
| } |
| |
| // Otherwise find a per-region table to add it to. |
| size_t ind = from_hrm_ind & _mod_max_fine_entries_mask; |
| PerRegionTable* prt = find_region_table(ind, from_hr); |
| if (prt == NULL) { |
| MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag); |
| // Confirm that it's really not there... |
| prt = find_region_table(ind, from_hr); |
| if (prt == NULL) { |
| |
| uintptr_t from_hr_bot_card_index = |
| uintptr_t(from_hr->bottom()) |
| >> CardTableModRefBS::card_shift; |
| CardIdx_t card_index = from_card - from_hr_bot_card_index; |
| assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion, |
| "Must be in range."); |
| if (G1HRRSUseSparseTable && |
| _sparse_table.add_card(from_hrm_ind, card_index)) { |
| assert(contains_reference_locked(from), "We just added " PTR_FORMAT " to the Sparse table", p2i(from)); |
| return; |
| } |
| |
| if (_n_fine_entries == _max_fine_entries) { |
| prt = delete_region_table(); |
| // There is no need to clear the links to the 'all' list here: |
| // prt will be reused immediately, i.e. remain in the 'all' list. |
| prt->init(from_hr, false /* clear_links_to_all_list */); |
| } else { |
| prt = PerRegionTable::alloc(from_hr); |
| link_to_all(prt); |
| } |
| |
| PerRegionTable* first_prt = _fine_grain_regions[ind]; |
| prt->set_collision_list_next(first_prt); |
| // The assignment into _fine_grain_regions allows the prt to |
| // start being used concurrently. In addition to |
| // collision_list_next which must be visible (else concurrent |
| // parsing of the list, if any, may fail to see other entries), |
| // the content of the prt must be visible (else for instance |
| // some mark bits may not yet seem cleared or a 'later' update |
| // performed by a concurrent thread could be undone when the |
| // zeroing becomes visible). This requires store ordering. |
| OrderAccess::release_store_ptr((volatile PerRegionTable*)&_fine_grain_regions[ind], prt); |
| _n_fine_entries++; |
| |
| if (G1HRRSUseSparseTable) { |
| // Transfer from sparse to fine-grain. |
| SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrm_ind); |
| assert(sprt_entry != NULL, "There should have been an entry"); |
| for (int i = 0; i < SparsePRTEntry::cards_num(); i++) { |
| CardIdx_t c = sprt_entry->card(i); |
| if (c != SparsePRTEntry::NullEntry) { |
| prt->add_card(c); |
| } |
| } |
| // Now we can delete the sparse entry. |
| bool res = _sparse_table.delete_entry(from_hrm_ind); |
| assert(res, "It should have been there."); |
| } |
| } |
| assert(prt != NULL && prt->hr() == from_hr, "consequence"); |
| } |
| // Note that we can't assert "prt->hr() == from_hr", because of the |
| // possibility of concurrent reuse. But see head comment of |
| // OtherRegionsTable for why this is OK. |
| assert(prt != NULL, "Inv"); |
| |
| prt->add_reference(from); |
| assert(contains_reference(from), "We just added " PTR_FORMAT " to the PRT", p2i(from)); |
| } |
| |
| PerRegionTable* |
| OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const { |
| assert(ind < _max_fine_entries, "Preconditions."); |
| PerRegionTable* prt = _fine_grain_regions[ind]; |
| while (prt != NULL && prt->hr() != hr) { |
| prt = prt->collision_list_next(); |
| } |
| // Loop postcondition is the method postcondition. |
| return prt; |
| } |
| |
| jint OtherRegionsTable::_n_coarsenings = 0; |
| |
| PerRegionTable* OtherRegionsTable::delete_region_table() { |
| assert(_m->owned_by_self(), "Precondition"); |
| assert(_n_fine_entries == _max_fine_entries, "Precondition"); |
| PerRegionTable* max = NULL; |
| jint max_occ = 0; |
| PerRegionTable** max_prev = NULL; |
| size_t max_ind; |
| |
| size_t i = _fine_eviction_start; |
| for (size_t k = 0; k < _fine_eviction_sample_size; k++) { |
| size_t ii = i; |
| // Make sure we get a non-NULL sample. |
| while (_fine_grain_regions[ii] == NULL) { |
| ii++; |
| if (ii == _max_fine_entries) ii = 0; |
| guarantee(ii != i, "We must find one."); |
| } |
| PerRegionTable** prev = &_fine_grain_regions[ii]; |
| PerRegionTable* cur = *prev; |
| while (cur != NULL) { |
| jint cur_occ = cur->occupied(); |
| if (max == NULL || cur_occ > max_occ) { |
| max = cur; |
| max_prev = prev; |
| max_ind = i; |
| max_occ = cur_occ; |
| } |
| prev = cur->collision_list_next_addr(); |
| cur = cur->collision_list_next(); |
| } |
| i = i + _fine_eviction_stride; |
| if (i >= _n_fine_entries) i = i - _n_fine_entries; |
| } |
| |
| _fine_eviction_start++; |
| |
| if (_fine_eviction_start >= _n_fine_entries) { |
| _fine_eviction_start -= _n_fine_entries; |
| } |
| |
| guarantee(max != NULL, "Since _n_fine_entries > 0"); |
| guarantee(max_prev != NULL, "Since max != NULL."); |
| |
| // Set the corresponding coarse bit. |
| size_t max_hrm_index = (size_t) max->hr()->hrm_index(); |
| if (!_coarse_map.at(max_hrm_index)) { |
| _coarse_map.at_put(max_hrm_index, true); |
| _n_coarse_entries++; |
| } |
| |
| // Unsplice. |
| *max_prev = max->collision_list_next(); |
| Atomic::inc(&_n_coarsenings); |
| _n_fine_entries--; |
| return max; |
| } |
| |
| void OtherRegionsTable::scrub(CardTableModRefBS* ctbs, |
| BitMap* region_bm, BitMap* card_bm) { |
| // First eliminated garbage regions from the coarse map. |
| log_develop_trace(gc, remset, scrub)("Scrubbing region %u:", _hr->hrm_index()); |
| |
| assert(_coarse_map.size() == region_bm->size(), "Precondition"); |
| log_develop_trace(gc, remset, scrub)(" Coarse map: before = " SIZE_FORMAT "...", _n_coarse_entries); |
| _coarse_map.set_intersection(*region_bm); |
| _n_coarse_entries = _coarse_map.count_one_bits(); |
| log_develop_trace(gc, remset, scrub)(" after = " SIZE_FORMAT ".", _n_coarse_entries); |
| |
| // Now do the fine-grained maps. |
| for (size_t i = 0; i < _max_fine_entries; i++) { |
| PerRegionTable* cur = _fine_grain_regions[i]; |
| PerRegionTable** prev = &_fine_grain_regions[i]; |
| while (cur != NULL) { |
| PerRegionTable* nxt = cur->collision_list_next(); |
| // If the entire region is dead, eliminate. |
| log_develop_trace(gc, remset, scrub)(" For other region %u:", cur->hr()->hrm_index()); |
| if (!region_bm->at((size_t) cur->hr()->hrm_index())) { |
| *prev = nxt; |
| cur->set_collision_list_next(NULL); |
| _n_fine_entries--; |
| log_develop_trace(gc, remset, scrub)(" deleted via region map."); |
| unlink_from_all(cur); |
| PerRegionTable::free(cur); |
| } else { |
| // Do fine-grain elimination. |
| log_develop_trace(gc, remset, scrub)(" occ: before = %4d.", cur->occupied()); |
| cur->scrub(ctbs, card_bm); |
| log_develop_trace(gc, remset, scrub)(" after = %4d.", cur->occupied()); |
| // Did that empty the table completely? |
| if (cur->occupied() == 0) { |
| *prev = nxt; |
| cur->set_collision_list_next(NULL); |
| _n_fine_entries--; |
| unlink_from_all(cur); |
| PerRegionTable::free(cur); |
| } else { |
| prev = cur->collision_list_next_addr(); |
| } |
| } |
| cur = nxt; |
| } |
| } |
| // Since we may have deleted a from_card_cache entry from the RS, clear |
| // the FCC. |
| clear_fcc(); |
| } |
| |
| bool OtherRegionsTable::occupancy_less_or_equal_than(size_t limit) const { |
| if (limit <= (size_t)G1RSetSparseRegionEntries) { |
| return occ_coarse() == 0 && _first_all_fine_prts == NULL && occ_sparse() <= limit; |
| } else { |
| // Current uses of this method may only use values less than G1RSetSparseRegionEntries |
| // for the limit. The solution, comparing against occupied() would be too slow |
| // at this time. |
| Unimplemented(); |
| return false; |
| } |
| } |
| |
| bool OtherRegionsTable::is_empty() const { |
| return occ_sparse() == 0 && occ_coarse() == 0 && _first_all_fine_prts == NULL; |
| } |
| |
| size_t OtherRegionsTable::occupied() const { |
| size_t sum = occ_fine(); |
| sum += occ_sparse(); |
| sum += occ_coarse(); |
| return sum; |
| } |
| |
| size_t OtherRegionsTable::occ_fine() const { |
| size_t sum = 0; |
| |
| size_t num = 0; |
| PerRegionTable * cur = _first_all_fine_prts; |
| while (cur != NULL) { |
| sum += cur->occupied(); |
| cur = cur->next(); |
| num++; |
| } |
| guarantee(num == _n_fine_entries, "just checking"); |
| return sum; |
| } |
| |
| size_t OtherRegionsTable::occ_coarse() const { |
| return (_n_coarse_entries * HeapRegion::CardsPerRegion); |
| } |
| |
| size_t OtherRegionsTable::occ_sparse() const { |
| return _sparse_table.occupied(); |
| } |
| |
| size_t OtherRegionsTable::mem_size() const { |
| size_t sum = 0; |
| // all PRTs are of the same size so it is sufficient to query only one of them. |
| if (_first_all_fine_prts != NULL) { |
| assert(_last_all_fine_prts != NULL && |
| _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant"); |
| sum += _first_all_fine_prts->mem_size() * _n_fine_entries; |
| } |
| sum += (sizeof(PerRegionTable*) * _max_fine_entries); |
| sum += (_coarse_map.size_in_words() * HeapWordSize); |
| sum += (_sparse_table.mem_size()); |
| sum += sizeof(OtherRegionsTable) - sizeof(_sparse_table); // Avoid double counting above. |
| return sum; |
| } |
| |
| size_t OtherRegionsTable::static_mem_size() { |
| return G1FromCardCache::static_mem_size(); |
| } |
| |
| size_t OtherRegionsTable::fl_mem_size() { |
| return PerRegionTable::fl_mem_size(); |
| } |
| |
| void OtherRegionsTable::clear_fcc() { |
| G1FromCardCache::clear(_hr->hrm_index()); |
| } |
| |
| void OtherRegionsTable::clear() { |
| // if there are no entries, skip this step |
| if (_first_all_fine_prts != NULL) { |
| guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking"); |
| PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts); |
| memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0])); |
| } else { |
| guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking"); |
| } |
| |
| _first_all_fine_prts = _last_all_fine_prts = NULL; |
| _sparse_table.clear(); |
| _coarse_map.clear(); |
| _n_fine_entries = 0; |
| _n_coarse_entries = 0; |
| |
| clear_fcc(); |
| } |
| |
| bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const { |
| // Cast away const in this case. |
| MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag); |
| return contains_reference_locked(from); |
| } |
| |
| bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const { |
| HeapRegion* hr = _g1h->heap_region_containing(from); |
| RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index(); |
| // Is this region in the coarse map? |
| if (_coarse_map.at(hr_ind)) return true; |
| |
| PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask, |
| hr); |
| if (prt != NULL) { |
| return prt->contains_reference(from); |
| |
| } else { |
| uintptr_t from_card = |
| (uintptr_t(from) >> CardTableModRefBS::card_shift); |
| uintptr_t hr_bot_card_index = |
| uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift; |
| assert(from_card >= hr_bot_card_index, "Inv"); |
| CardIdx_t card_index = from_card - hr_bot_card_index; |
| assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion, |
| "Must be in range."); |
| return _sparse_table.contains_card(hr_ind, card_index); |
| } |
| } |
| |
| void |
| OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) { |
| _sparse_table.do_cleanup_work(hrrs_cleanup_task); |
| } |
| |
| HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetTable* bot, |
| HeapRegion* hr) |
| : _bot(bot), |
| _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true, Monitor::_safepoint_check_never), |
| _code_roots(), _other_regions(hr, &_m), _iter_state(Unclaimed), _iter_claimed(0) { |
| reset_for_par_iteration(); |
| } |
| |
| void HeapRegionRemSet::setup_remset_size() { |
| // Setup sparse and fine-grain tables sizes. |
| // table_size = base * (log(region_size / 1M) + 1) |
| const int LOG_M = 20; |
| int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0); |
| if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) { |
| G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1); |
| } |
| if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) { |
| G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1); |
| } |
| guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity"); |
| } |
| |
| bool HeapRegionRemSet::claim_iter() { |
| if (_iter_state != Unclaimed) return false; |
| jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed); |
| return (res == Unclaimed); |
| } |
| |
| void HeapRegionRemSet::set_iter_complete() { |
| _iter_state = Complete; |
| } |
| |
| bool HeapRegionRemSet::iter_is_complete() { |
| return _iter_state == Complete; |
| } |
| |
| #ifndef PRODUCT |
| void HeapRegionRemSet::print() { |
| HeapRegionRemSetIterator iter(this); |
| size_t card_index; |
| while (iter.has_next(card_index)) { |
| HeapWord* card_start = _bot->address_for_index(card_index); |
| tty->print_cr(" Card " PTR_FORMAT, p2i(card_start)); |
| } |
| if (iter.n_yielded() != occupied()) { |
| tty->print_cr("Yielded disagrees with occupied:"); |
| tty->print_cr(" " SIZE_FORMAT_W(6) " yielded (" SIZE_FORMAT_W(6) |
| " coarse, " SIZE_FORMAT_W(6) " fine).", |
| iter.n_yielded(), |
| iter.n_yielded_coarse(), iter.n_yielded_fine()); |
| tty->print_cr(" " SIZE_FORMAT_W(6) " occ (" SIZE_FORMAT_W(6) |
| " coarse, " SIZE_FORMAT_W(6) " fine).", |
| occupied(), occ_coarse(), occ_fine()); |
| } |
| guarantee(iter.n_yielded() == occupied(), |
| "We should have yielded all the represented cards."); |
| } |
| #endif |
| |
| void HeapRegionRemSet::cleanup() { |
| SparsePRT::cleanup_all(); |
| } |
| |
| void HeapRegionRemSet::clear() { |
| MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); |
| clear_locked(); |
| } |
| |
| void HeapRegionRemSet::clear_locked() { |
| _code_roots.clear(); |
| _other_regions.clear(); |
| assert(occupied_locked() == 0, "Should be clear."); |
| reset_for_par_iteration(); |
| } |
| |
| void HeapRegionRemSet::reset_for_par_iteration() { |
| _iter_state = Unclaimed; |
| _iter_claimed = 0; |
| // It's good to check this to make sure that the two methods are in sync. |
| assert(verify_ready_for_par_iteration(), "post-condition"); |
| } |
| |
| void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs, |
| BitMap* region_bm, BitMap* card_bm) { |
| _other_regions.scrub(ctbs, region_bm, card_bm); |
| } |
| |
| // Code roots support |
| // |
| // The code root set is protected by two separate locking schemes |
| // When at safepoint the per-hrrs lock must be held during modifications |
| // except when doing a full gc. |
| // When not at safepoint the CodeCache_lock must be held during modifications. |
| // When concurrent readers access the contains() function |
| // (during the evacuation phase) no removals are allowed. |
| |
| void HeapRegionRemSet::add_strong_code_root(nmethod* nm) { |
| assert(nm != NULL, "sanity"); |
| assert((!CodeCache_lock->owned_by_self() || SafepointSynchronize::is_at_safepoint()), |
| "should call add_strong_code_root_locked instead. CodeCache_lock->owned_by_self(): %s, is_at_safepoint(): %s", |
| BOOL_TO_STR(CodeCache_lock->owned_by_self()), BOOL_TO_STR(SafepointSynchronize::is_at_safepoint())); |
| // Optimistic unlocked contains-check |
| if (!_code_roots.contains(nm)) { |
| MutexLockerEx ml(&_m, Mutex::_no_safepoint_check_flag); |
| add_strong_code_root_locked(nm); |
| } |
| } |
| |
| void HeapRegionRemSet::add_strong_code_root_locked(nmethod* nm) { |
| assert(nm != NULL, "sanity"); |
| assert((CodeCache_lock->owned_by_self() || |
| (SafepointSynchronize::is_at_safepoint() && |
| (_m.owned_by_self() || Thread::current()->is_VM_thread()))), |
| "not safely locked. CodeCache_lock->owned_by_self(): %s, is_at_safepoint(): %s, _m.owned_by_self(): %s, Thread::current()->is_VM_thread(): %s", |
| BOOL_TO_STR(CodeCache_lock->owned_by_self()), BOOL_TO_STR(SafepointSynchronize::is_at_safepoint()), |
| BOOL_TO_STR(_m.owned_by_self()), BOOL_TO_STR(Thread::current()->is_VM_thread())); |
| _code_roots.add(nm); |
| } |
| |
| void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) { |
| assert(nm != NULL, "sanity"); |
| assert_locked_or_safepoint(CodeCache_lock); |
| |
| MutexLockerEx ml(CodeCache_lock->owned_by_self() ? NULL : &_m, Mutex::_no_safepoint_check_flag); |
| _code_roots.remove(nm); |
| |
| // Check that there were no duplicates |
| guarantee(!_code_roots.contains(nm), "duplicate entry found"); |
| } |
| |
| void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const { |
| _code_roots.nmethods_do(blk); |
| } |
| |
| void HeapRegionRemSet::clean_strong_code_roots(HeapRegion* hr) { |
| _code_roots.clean(hr); |
| } |
| |
| size_t HeapRegionRemSet::strong_code_roots_mem_size() { |
| return _code_roots.mem_size(); |
| } |
| |
| HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) : |
| _hrrs(hrrs), |
| _g1h(G1CollectedHeap::heap()), |
| _coarse_map(&hrrs->_other_regions._coarse_map), |
| _bot(hrrs->_bot), |
| _is(Sparse), |
| // Set these values so that we increment to the first region. |
| _coarse_cur_region_index(-1), |
| _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1), |
| _cur_card_in_prt(HeapRegion::CardsPerRegion), |
| _fine_cur_prt(NULL), |
| _n_yielded_coarse(0), |
| _n_yielded_fine(0), |
| _n_yielded_sparse(0), |
| _sparse_iter(&hrrs->_other_regions._sparse_table) {} |
| |
| bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) { |
| if (_hrrs->_other_regions._n_coarse_entries == 0) return false; |
| // Go to the next card. |
| _coarse_cur_region_cur_card++; |
| // Was the last the last card in the current region? |
| if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) { |
| // Yes: find the next region. This may leave _coarse_cur_region_index |
| // Set to the last index, in which case there are no more coarse |
| // regions. |
| _coarse_cur_region_index = |
| (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1); |
| if ((size_t)_coarse_cur_region_index < _coarse_map->size()) { |
| _coarse_cur_region_cur_card = 0; |
| HeapWord* r_bot = |
| _g1h->region_at((uint) _coarse_cur_region_index)->bottom(); |
| _cur_region_card_offset = _bot->index_for(r_bot); |
| } else { |
| return false; |
| } |
| } |
| // If we didn't return false above, then we can yield a card. |
| card_index = _cur_region_card_offset + _coarse_cur_region_cur_card; |
| return true; |
| } |
| |
| bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) { |
| if (fine_has_next()) { |
| _cur_card_in_prt = |
| _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1); |
| } |
| if (_cur_card_in_prt == HeapRegion::CardsPerRegion) { |
| // _fine_cur_prt may still be NULL in case if there are not PRTs at all for |
| // the remembered set. |
| if (_fine_cur_prt == NULL || _fine_cur_prt->next() == NULL) { |
| return false; |
| } |
| PerRegionTable* next_prt = _fine_cur_prt->next(); |
| switch_to_prt(next_prt); |
| _cur_card_in_prt = _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1); |
| } |
| |
| card_index = _cur_region_card_offset + _cur_card_in_prt; |
| guarantee(_cur_card_in_prt < HeapRegion::CardsPerRegion, |
| "Card index " SIZE_FORMAT " must be within the region", _cur_card_in_prt); |
| return true; |
| } |
| |
| bool HeapRegionRemSetIterator::fine_has_next() { |
| return _cur_card_in_prt != HeapRegion::CardsPerRegion; |
| } |
| |
| void HeapRegionRemSetIterator::switch_to_prt(PerRegionTable* prt) { |
| assert(prt != NULL, "Cannot switch to NULL prt"); |
| _fine_cur_prt = prt; |
| |
| HeapWord* r_bot = _fine_cur_prt->hr()->bottom(); |
| _cur_region_card_offset = _bot->index_for(r_bot); |
| |
| // The bitmap scan for the PRT always scans from _cur_region_cur_card + 1. |
| // To avoid special-casing this start case, and not miss the first bitmap |
| // entry, initialize _cur_region_cur_card with -1 instead of 0. |
| _cur_card_in_prt = (size_t)-1; |
| } |
| |
| bool HeapRegionRemSetIterator::has_next(size_t& card_index) { |
| switch (_is) { |
| case Sparse: { |
| if (_sparse_iter.has_next(card_index)) { |
| _n_yielded_sparse++; |
| return true; |
| } |
| // Otherwise, deliberate fall-through |
| _is = Fine; |
| PerRegionTable* initial_fine_prt = _hrrs->_other_regions._first_all_fine_prts; |
| if (initial_fine_prt != NULL) { |
| switch_to_prt(_hrrs->_other_regions._first_all_fine_prts); |
| } |
| } |
| case Fine: |
| if (fine_has_next(card_index)) { |
| _n_yielded_fine++; |
| return true; |
| } |
| // Otherwise, deliberate fall-through |
| _is = Coarse; |
| case Coarse: |
| if (coarse_has_next(card_index)) { |
| _n_yielded_coarse++; |
| return true; |
| } |
| // Otherwise... |
| break; |
| } |
| assert(ParallelGCThreads > 1 || |
| n_yielded() == _hrrs->occupied(), |
| "Should have yielded all the cards in the rem set " |
| "(in the non-par case)."); |
| return false; |
| } |
| |
| void HeapRegionRemSet::reset_for_cleanup_tasks() { |
| SparsePRT::reset_for_cleanup_tasks(); |
| } |
| |
| void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) { |
| _other_regions.do_cleanup_work(hrrs_cleanup_task); |
| } |
| |
| void |
| HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) { |
| SparsePRT::finish_cleanup_task(hrrs_cleanup_task); |
| } |
| |
| #ifndef PRODUCT |
| void HeapRegionRemSet::test() { |
| os::sleep(Thread::current(), (jlong)5000, false); |
| G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
| |
| // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same |
| // hash bucket. |
| HeapRegion* hr0 = g1h->region_at(0); |
| HeapRegion* hr1 = g1h->region_at(1); |
| HeapRegion* hr2 = g1h->region_at(5); |
| HeapRegion* hr3 = g1h->region_at(6); |
| HeapRegion* hr4 = g1h->region_at(7); |
| HeapRegion* hr5 = g1h->region_at(8); |
| |
| HeapWord* hr1_start = hr1->bottom(); |
| HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2; |
| HeapWord* hr1_last = hr1->end() - 1; |
| |
| HeapWord* hr2_start = hr2->bottom(); |
| HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2; |
| HeapWord* hr2_last = hr2->end() - 1; |
| |
| HeapWord* hr3_start = hr3->bottom(); |
| HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2; |
| HeapWord* hr3_last = hr3->end() - 1; |
| |
| HeapRegionRemSet* hrrs = hr0->rem_set(); |
| |
| // Make three references from region 0x101... |
| hrrs->add_reference((OopOrNarrowOopStar)hr1_start); |
| hrrs->add_reference((OopOrNarrowOopStar)hr1_mid); |
| hrrs->add_reference((OopOrNarrowOopStar)hr1_last); |
| |
| hrrs->add_reference((OopOrNarrowOopStar)hr2_start); |
| hrrs->add_reference((OopOrNarrowOopStar)hr2_mid); |
| hrrs->add_reference((OopOrNarrowOopStar)hr2_last); |
| |
| hrrs->add_reference((OopOrNarrowOopStar)hr3_start); |
| hrrs->add_reference((OopOrNarrowOopStar)hr3_mid); |
| hrrs->add_reference((OopOrNarrowOopStar)hr3_last); |
| |
| // Now cause a coarsening. |
| hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom()); |
| hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom()); |
| |
| // Now, does iteration yield these three? |
| HeapRegionRemSetIterator iter(hrrs); |
| size_t sum = 0; |
| size_t card_index; |
| while (iter.has_next(card_index)) { |
| HeapWord* card_start = |
| G1CollectedHeap::heap()->bot()->address_for_index(card_index); |
| tty->print_cr(" Card " PTR_FORMAT ".", p2i(card_start)); |
| sum++; |
| } |
| guarantee(sum == 11 - 3 + 2048, "Failure"); |
| guarantee(sum == hrrs->occupied(), "Failure"); |
| } |
| #endif |