| /* |
| * Copyright (c) 2001, 2014, 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 |
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| * |
| */ |
| |
| #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_INLINE_HPP |
| #define SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_INLINE_HPP |
| |
| #include "gc_implementation/g1/concurrentMark.hpp" |
| #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" |
| |
| // Utility routine to set an exclusive range of cards on the given |
| // card liveness bitmap |
| inline void ConcurrentMark::set_card_bitmap_range(BitMap* card_bm, |
| BitMap::idx_t start_idx, |
| BitMap::idx_t end_idx, |
| bool is_par) { |
| |
| // Set the exclusive bit range [start_idx, end_idx). |
| assert((end_idx - start_idx) > 0, "at least one card"); |
| assert(end_idx <= card_bm->size(), "sanity"); |
| |
| // Silently clip the end index |
| end_idx = MIN2(end_idx, card_bm->size()); |
| |
| // For small ranges use a simple loop; otherwise use set_range or |
| // use par_at_put_range (if parallel). The range is made up of the |
| // cards that are spanned by an object/mem region so 8 cards will |
| // allow up to object sizes up to 4K to be handled using the loop. |
| if ((end_idx - start_idx) <= 8) { |
| for (BitMap::idx_t i = start_idx; i < end_idx; i += 1) { |
| if (is_par) { |
| card_bm->par_set_bit(i); |
| } else { |
| card_bm->set_bit(i); |
| } |
| } |
| } else { |
| // Note BitMap::par_at_put_range() and BitMap::set_range() are exclusive. |
| if (is_par) { |
| card_bm->par_at_put_range(start_idx, end_idx, true); |
| } else { |
| card_bm->set_range(start_idx, end_idx); |
| } |
| } |
| } |
| |
| // Returns the index in the liveness accounting card bitmap |
| // for the given address |
| inline BitMap::idx_t ConcurrentMark::card_bitmap_index_for(HeapWord* addr) { |
| // Below, the term "card num" means the result of shifting an address |
| // by the card shift -- address 0 corresponds to card number 0. One |
| // must subtract the card num of the bottom of the heap to obtain a |
| // card table index. |
| intptr_t card_num = intptr_t(uintptr_t(addr) >> CardTableModRefBS::card_shift); |
| return card_num - heap_bottom_card_num(); |
| } |
| |
| // Counts the given memory region in the given task/worker |
| // counting data structures. |
| inline void ConcurrentMark::count_region(MemRegion mr, HeapRegion* hr, |
| size_t* marked_bytes_array, |
| BitMap* task_card_bm) { |
| G1CollectedHeap* g1h = _g1h; |
| CardTableModRefBS* ct_bs = g1h->g1_barrier_set(); |
| |
| HeapWord* start = mr.start(); |
| HeapWord* end = mr.end(); |
| size_t region_size_bytes = mr.byte_size(); |
| uint index = hr->hrm_index(); |
| |
| assert(!hr->continuesHumongous(), "should not be HC region"); |
| assert(hr == g1h->heap_region_containing(start), "sanity"); |
| assert(hr == g1h->heap_region_containing(mr.last()), "sanity"); |
| assert(marked_bytes_array != NULL, "pre-condition"); |
| assert(task_card_bm != NULL, "pre-condition"); |
| |
| // Add to the task local marked bytes for this region. |
| marked_bytes_array[index] += region_size_bytes; |
| |
| BitMap::idx_t start_idx = card_bitmap_index_for(start); |
| BitMap::idx_t end_idx = card_bitmap_index_for(end); |
| |
| // Note: if we're looking at the last region in heap - end |
| // could be actually just beyond the end of the heap; end_idx |
| // will then correspond to a (non-existent) card that is also |
| // just beyond the heap. |
| if (g1h->is_in_g1_reserved(end) && !ct_bs->is_card_aligned(end)) { |
| // end of region is not card aligned - incremement to cover |
| // all the cards spanned by the region. |
| end_idx += 1; |
| } |
| // The card bitmap is task/worker specific => no need to use |
| // the 'par' BitMap routines. |
| // Set bits in the exclusive bit range [start_idx, end_idx). |
| set_card_bitmap_range(task_card_bm, start_idx, end_idx, false /* is_par */); |
| } |
| |
| // Counts the given memory region in the task/worker counting |
| // data structures for the given worker id. |
| inline void ConcurrentMark::count_region(MemRegion mr, |
| HeapRegion* hr, |
| uint worker_id) { |
| size_t* marked_bytes_array = count_marked_bytes_array_for(worker_id); |
| BitMap* task_card_bm = count_card_bitmap_for(worker_id); |
| count_region(mr, hr, marked_bytes_array, task_card_bm); |
| } |
| |
| // Counts the given object in the given task/worker counting data structures. |
| inline void ConcurrentMark::count_object(oop obj, |
| HeapRegion* hr, |
| size_t* marked_bytes_array, |
| BitMap* task_card_bm) { |
| MemRegion mr((HeapWord*)obj, obj->size()); |
| count_region(mr, hr, marked_bytes_array, task_card_bm); |
| } |
| |
| // Attempts to mark the given object and, if successful, counts |
| // the object in the given task/worker counting structures. |
| inline bool ConcurrentMark::par_mark_and_count(oop obj, |
| HeapRegion* hr, |
| size_t* marked_bytes_array, |
| BitMap* task_card_bm) { |
| HeapWord* addr = (HeapWord*)obj; |
| if (_nextMarkBitMap->parMark(addr)) { |
| // Update the task specific count data for the object. |
| count_object(obj, hr, marked_bytes_array, task_card_bm); |
| return true; |
| } |
| return false; |
| } |
| |
| // Attempts to mark the given object and, if successful, counts |
| // the object in the task/worker counting structures for the |
| // given worker id. |
| inline bool ConcurrentMark::par_mark_and_count(oop obj, |
| size_t word_size, |
| HeapRegion* hr, |
| uint worker_id) { |
| HeapWord* addr = (HeapWord*)obj; |
| if (_nextMarkBitMap->parMark(addr)) { |
| MemRegion mr(addr, word_size); |
| count_region(mr, hr, worker_id); |
| return true; |
| } |
| return false; |
| } |
| |
| inline bool CMBitMapRO::iterate(BitMapClosure* cl, MemRegion mr) { |
| HeapWord* start_addr = MAX2(startWord(), mr.start()); |
| HeapWord* end_addr = MIN2(endWord(), mr.end()); |
| |
| if (end_addr > start_addr) { |
| // Right-open interval [start-offset, end-offset). |
| BitMap::idx_t start_offset = heapWordToOffset(start_addr); |
| BitMap::idx_t end_offset = heapWordToOffset(end_addr); |
| |
| start_offset = _bm.get_next_one_offset(start_offset, end_offset); |
| while (start_offset < end_offset) { |
| if (!cl->do_bit(start_offset)) { |
| return false; |
| } |
| HeapWord* next_addr = MIN2(nextObject(offsetToHeapWord(start_offset)), end_addr); |
| BitMap::idx_t next_offset = heapWordToOffset(next_addr); |
| start_offset = _bm.get_next_one_offset(next_offset, end_offset); |
| } |
| } |
| return true; |
| } |
| |
| inline bool CMBitMapRO::iterate(BitMapClosure* cl) { |
| MemRegion mr(startWord(), sizeInWords()); |
| return iterate(cl, mr); |
| } |
| |
| #define check_mark(addr) \ |
| assert(_bmStartWord <= (addr) && (addr) < (_bmStartWord + _bmWordSize), \ |
| "outside underlying space?"); \ |
| assert(G1CollectedHeap::heap()->is_in_exact(addr), \ |
| err_msg("Trying to access not available bitmap "PTR_FORMAT \ |
| " corresponding to "PTR_FORMAT" (%u)", \ |
| p2i(this), p2i(addr), G1CollectedHeap::heap()->addr_to_region(addr))); |
| |
| inline void CMBitMap::mark(HeapWord* addr) { |
| check_mark(addr); |
| _bm.set_bit(heapWordToOffset(addr)); |
| } |
| |
| inline void CMBitMap::clear(HeapWord* addr) { |
| check_mark(addr); |
| _bm.clear_bit(heapWordToOffset(addr)); |
| } |
| |
| inline bool CMBitMap::parMark(HeapWord* addr) { |
| check_mark(addr); |
| return _bm.par_set_bit(heapWordToOffset(addr)); |
| } |
| |
| inline bool CMBitMap::parClear(HeapWord* addr) { |
| check_mark(addr); |
| return _bm.par_clear_bit(heapWordToOffset(addr)); |
| } |
| |
| #undef check_mark |
| |
| inline void CMTask::push(oop obj) { |
| HeapWord* objAddr = (HeapWord*) obj; |
| assert(_g1h->is_in_g1_reserved(objAddr), "invariant"); |
| assert(!_g1h->is_on_master_free_list( |
| _g1h->heap_region_containing((HeapWord*) objAddr)), "invariant"); |
| assert(!_g1h->is_obj_ill(obj), "invariant"); |
| assert(_nextMarkBitMap->isMarked(objAddr), "invariant"); |
| |
| if (_cm->verbose_high()) { |
| gclog_or_tty->print_cr("[%u] pushing " PTR_FORMAT, _worker_id, p2i((void*) obj)); |
| } |
| |
| if (!_task_queue->push(obj)) { |
| // The local task queue looks full. We need to push some entries |
| // to the global stack. |
| |
| if (_cm->verbose_medium()) { |
| gclog_or_tty->print_cr("[%u] task queue overflow, " |
| "moving entries to the global stack", |
| _worker_id); |
| } |
| move_entries_to_global_stack(); |
| |
| // this should succeed since, even if we overflow the global |
| // stack, we should have definitely removed some entries from the |
| // local queue. So, there must be space on it. |
| bool success = _task_queue->push(obj); |
| assert(success, "invariant"); |
| } |
| |
| statsOnly( int tmp_size = _task_queue->size(); |
| if (tmp_size > _local_max_size) { |
| _local_max_size = tmp_size; |
| } |
| ++_local_pushes ); |
| } |
| |
| inline bool CMTask::is_below_finger(oop obj, HeapWord* global_finger) const { |
| // If obj is above the global finger, then the mark bitmap scan |
| // will find it later, and no push is needed. Similarly, if we have |
| // a current region and obj is between the local finger and the |
| // end of the current region, then no push is needed. The tradeoff |
| // of checking both vs only checking the global finger is that the |
| // local check will be more accurate and so result in fewer pushes, |
| // but may also be a little slower. |
| HeapWord* objAddr = (HeapWord*)obj; |
| if (_finger != NULL) { |
| // We have a current region. |
| |
| // Finger and region values are all NULL or all non-NULL. We |
| // use _finger to check since we immediately use its value. |
| assert(_curr_region != NULL, "invariant"); |
| assert(_region_limit != NULL, "invariant"); |
| assert(_region_limit <= global_finger, "invariant"); |
| |
| // True if obj is less than the local finger, or is between |
| // the region limit and the global finger. |
| if (objAddr < _finger) { |
| return true; |
| } else if (objAddr < _region_limit) { |
| return false; |
| } // Else check global finger. |
| } |
| // Check global finger. |
| return objAddr < global_finger; |
| } |
| |
| inline void CMTask::make_reference_grey(oop obj, HeapRegion* hr) { |
| if (_cm->par_mark_and_count(obj, hr, _marked_bytes_array, _card_bm)) { |
| |
| if (_cm->verbose_high()) { |
| gclog_or_tty->print_cr("[%u] marked object " PTR_FORMAT, |
| _worker_id, p2i(obj)); |
| } |
| |
| // No OrderAccess:store_load() is needed. It is implicit in the |
| // CAS done in CMBitMap::parMark() call in the routine above. |
| HeapWord* global_finger = _cm->finger(); |
| |
| // We only need to push a newly grey object on the mark |
| // stack if it is in a section of memory the mark bitmap |
| // scan has already examined. Mark bitmap scanning |
| // maintains progress "fingers" for determining that. |
| // |
| // Notice that the global finger might be moving forward |
| // concurrently. This is not a problem. In the worst case, we |
| // mark the object while it is above the global finger and, by |
| // the time we read the global finger, it has moved forward |
| // past this object. In this case, the object will probably |
| // be visited when a task is scanning the region and will also |
| // be pushed on the stack. So, some duplicate work, but no |
| // correctness problems. |
| if (is_below_finger(obj, global_finger)) { |
| if (obj->is_typeArray()) { |
| // Immediately process arrays of primitive types, rather |
| // than pushing on the mark stack. This keeps us from |
| // adding humongous objects to the mark stack that might |
| // be reclaimed before the entry is processed - see |
| // selection of candidates for eager reclaim of humongous |
| // objects. The cost of the additional type test is |
| // mitigated by avoiding a trip through the mark stack, |
| // by only doing a bookkeeping update and avoiding the |
| // actual scan of the object - a typeArray contains no |
| // references, and the metadata is built-in. |
| process_grey_object<false>(obj); |
| } else { |
| if (_cm->verbose_high()) { |
| gclog_or_tty->print_cr("[%u] below a finger (local: " PTR_FORMAT |
| ", global: " PTR_FORMAT ") pushing " |
| PTR_FORMAT " on mark stack", |
| _worker_id, p2i(_finger), |
| p2i(global_finger), p2i(obj)); |
| } |
| push(obj); |
| } |
| } |
| } |
| } |
| |
| inline void CMTask::deal_with_reference(oop obj) { |
| if (_cm->verbose_high()) { |
| gclog_or_tty->print_cr("[%u] we're dealing with reference = "PTR_FORMAT, |
| _worker_id, p2i((void*) obj)); |
| } |
| |
| increment_refs_reached(); |
| |
| HeapWord* objAddr = (HeapWord*) obj; |
| assert(obj->is_oop_or_null(true /* ignore mark word */), "Error"); |
| if (_g1h->is_in_g1_reserved(objAddr)) { |
| assert(obj != NULL, "null check is implicit"); |
| if (!_nextMarkBitMap->isMarked(objAddr)) { |
| // Only get the containing region if the object is not marked on the |
| // bitmap (otherwise, it's a waste of time since we won't do |
| // anything with it). |
| HeapRegion* hr = _g1h->heap_region_containing_raw(obj); |
| if (!hr->obj_allocated_since_next_marking(obj)) { |
| make_reference_grey(obj, hr); |
| } |
| } |
| } |
| } |
| |
| inline void ConcurrentMark::markPrev(oop p) { |
| assert(!_prevMarkBitMap->isMarked((HeapWord*) p), "sanity"); |
| // Note we are overriding the read-only view of the prev map here, via |
| // the cast. |
| ((CMBitMap*)_prevMarkBitMap)->mark((HeapWord*) p); |
| } |
| |
| inline void ConcurrentMark::grayRoot(oop obj, size_t word_size, |
| uint worker_id, HeapRegion* hr) { |
| assert(obj != NULL, "pre-condition"); |
| HeapWord* addr = (HeapWord*) obj; |
| if (hr == NULL) { |
| hr = _g1h->heap_region_containing_raw(addr); |
| } else { |
| assert(hr->is_in(addr), "pre-condition"); |
| } |
| assert(hr != NULL, "sanity"); |
| // Given that we're looking for a region that contains an object |
| // header it's impossible to get back a HC region. |
| assert(!hr->continuesHumongous(), "sanity"); |
| |
| // We cannot assert that word_size == obj->size() given that obj |
| // might not be in a consistent state (another thread might be in |
| // the process of copying it). So the best thing we can do is to |
| // assert that word_size is under an upper bound which is its |
| // containing region's capacity. |
| assert(word_size * HeapWordSize <= hr->capacity(), |
| err_msg("size: "SIZE_FORMAT" capacity: "SIZE_FORMAT" "HR_FORMAT, |
| word_size * HeapWordSize, hr->capacity(), |
| HR_FORMAT_PARAMS(hr))); |
| |
| if (addr < hr->next_top_at_mark_start()) { |
| if (!_nextMarkBitMap->isMarked(addr)) { |
| par_mark_and_count(obj, word_size, hr, worker_id); |
| } |
| } |
| } |
| |
| #endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_INLINE_HPP |