aoqi@0: /*
aoqi@0:  * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_INLINE_HPP
aoqi@0: #define SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_INLINE_HPP
aoqi@0: 
aoqi@0: #include "gc_implementation/g1/concurrentMark.hpp"
aoqi@0: #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
aoqi@0: 
aoqi@0: // Utility routine to set an exclusive range of cards on the given
aoqi@0: // card liveness bitmap
aoqi@0: inline void ConcurrentMark::set_card_bitmap_range(BitMap* card_bm,
aoqi@0:                                                   BitMap::idx_t start_idx,
aoqi@0:                                                   BitMap::idx_t end_idx,
aoqi@0:                                                   bool is_par) {
aoqi@0: 
aoqi@0:   // Set the exclusive bit range [start_idx, end_idx).
aoqi@0:   assert((end_idx - start_idx) > 0, "at least one card");
aoqi@0:   assert(end_idx <= card_bm->size(), "sanity");
aoqi@0: 
aoqi@0:   // Silently clip the end index
aoqi@0:   end_idx = MIN2(end_idx, card_bm->size());
aoqi@0: 
aoqi@0:   // For small ranges use a simple loop; otherwise use set_range or
aoqi@0:   // use par_at_put_range (if parallel). The range is made up of the
aoqi@0:   // cards that are spanned by an object/mem region so 8 cards will
aoqi@0:   // allow up to object sizes up to 4K to be handled using the loop.
aoqi@0:   if ((end_idx - start_idx) <= 8) {
aoqi@0:     for (BitMap::idx_t i = start_idx; i < end_idx; i += 1) {
aoqi@0:       if (is_par) {
aoqi@0:         card_bm->par_set_bit(i);
aoqi@0:       } else {
aoqi@0:         card_bm->set_bit(i);
aoqi@0:       }
aoqi@0:     }
aoqi@0:   } else {
aoqi@0:     // Note BitMap::par_at_put_range() and BitMap::set_range() are exclusive.
aoqi@0:     if (is_par) {
aoqi@0:       card_bm->par_at_put_range(start_idx, end_idx, true);
aoqi@0:     } else {
aoqi@0:       card_bm->set_range(start_idx, end_idx);
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // Returns the index in the liveness accounting card bitmap
aoqi@0: // for the given address
aoqi@0: inline BitMap::idx_t ConcurrentMark::card_bitmap_index_for(HeapWord* addr) {
aoqi@0:   // Below, the term "card num" means the result of shifting an address
aoqi@0:   // by the card shift -- address 0 corresponds to card number 0.  One
aoqi@0:   // must subtract the card num of the bottom of the heap to obtain a
aoqi@0:   // card table index.
aoqi@0:   intptr_t card_num = intptr_t(uintptr_t(addr) >> CardTableModRefBS::card_shift);
aoqi@0:   return card_num - heap_bottom_card_num();
aoqi@0: }
aoqi@0: 
aoqi@0: // Counts the given memory region in the given task/worker
aoqi@0: // counting data structures.
aoqi@0: inline void ConcurrentMark::count_region(MemRegion mr, HeapRegion* hr,
aoqi@0:                                          size_t* marked_bytes_array,
aoqi@0:                                          BitMap* task_card_bm) {
aoqi@0:   G1CollectedHeap* g1h = _g1h;
aoqi@0:   CardTableModRefBS* ct_bs = g1h->g1_barrier_set();
aoqi@0: 
aoqi@0:   HeapWord* start = mr.start();
aoqi@0:   HeapWord* end = mr.end();
aoqi@0:   size_t region_size_bytes = mr.byte_size();
aoqi@0:   uint index = hr->hrs_index();
aoqi@0: 
aoqi@0:   assert(!hr->continuesHumongous(), "should not be HC region");
aoqi@0:   assert(hr == g1h->heap_region_containing(start), "sanity");
aoqi@0:   assert(hr == g1h->heap_region_containing(mr.last()), "sanity");
aoqi@0:   assert(marked_bytes_array != NULL, "pre-condition");
aoqi@0:   assert(task_card_bm != NULL, "pre-condition");
aoqi@0: 
aoqi@0:   // Add to the task local marked bytes for this region.
aoqi@0:   marked_bytes_array[index] += region_size_bytes;
aoqi@0: 
aoqi@0:   BitMap::idx_t start_idx = card_bitmap_index_for(start);
aoqi@0:   BitMap::idx_t end_idx = card_bitmap_index_for(end);
aoqi@0: 
aoqi@0:   // Note: if we're looking at the last region in heap - end
aoqi@0:   // could be actually just beyond the end of the heap; end_idx
aoqi@0:   // will then correspond to a (non-existent) card that is also
aoqi@0:   // just beyond the heap.
aoqi@0:   if (g1h->is_in_g1_reserved(end) && !ct_bs->is_card_aligned(end)) {
aoqi@0:     // end of region is not card aligned - incremement to cover
aoqi@0:     // all the cards spanned by the region.
aoqi@0:     end_idx += 1;
aoqi@0:   }
aoqi@0:   // The card bitmap is task/worker specific => no need to use
aoqi@0:   // the 'par' BitMap routines.
aoqi@0:   // Set bits in the exclusive bit range [start_idx, end_idx).
aoqi@0:   set_card_bitmap_range(task_card_bm, start_idx, end_idx, false /* is_par */);
aoqi@0: }
aoqi@0: 
aoqi@0: // Counts the given memory region in the task/worker counting
aoqi@0: // data structures for the given worker id.
aoqi@0: inline void ConcurrentMark::count_region(MemRegion mr,
aoqi@0:                                          HeapRegion* hr,
aoqi@0:                                          uint worker_id) {
aoqi@0:   size_t* marked_bytes_array = count_marked_bytes_array_for(worker_id);
aoqi@0:   BitMap* task_card_bm = count_card_bitmap_for(worker_id);
aoqi@0:   count_region(mr, hr, marked_bytes_array, task_card_bm);
aoqi@0: }
aoqi@0: 
aoqi@0: // Counts the given memory region, which may be a single object, in the
aoqi@0: // task/worker counting data structures for the given worker id.
aoqi@0: inline void ConcurrentMark::count_region(MemRegion mr, uint worker_id) {
aoqi@0:   HeapWord* addr = mr.start();
aoqi@0:   HeapRegion* hr = _g1h->heap_region_containing_raw(addr);
aoqi@0:   count_region(mr, hr, worker_id);
aoqi@0: }
aoqi@0: 
aoqi@0: // Counts the given object in the given task/worker counting data structures.
aoqi@0: inline void ConcurrentMark::count_object(oop obj,
aoqi@0:                                          HeapRegion* hr,
aoqi@0:                                          size_t* marked_bytes_array,
aoqi@0:                                          BitMap* task_card_bm) {
aoqi@0:   MemRegion mr((HeapWord*)obj, obj->size());
aoqi@0:   count_region(mr, hr, marked_bytes_array, task_card_bm);
aoqi@0: }
aoqi@0: 
aoqi@0: // Counts the given object in the task/worker counting data
aoqi@0: // structures for the given worker id.
aoqi@0: inline void ConcurrentMark::count_object(oop obj,
aoqi@0:                                          HeapRegion* hr,
aoqi@0:                                          uint worker_id) {
aoqi@0:   size_t* marked_bytes_array = count_marked_bytes_array_for(worker_id);
aoqi@0:   BitMap* task_card_bm = count_card_bitmap_for(worker_id);
aoqi@0:   HeapWord* addr = (HeapWord*) obj;
aoqi@0:   count_object(obj, hr, marked_bytes_array, task_card_bm);
aoqi@0: }
aoqi@0: 
aoqi@0: // Attempts to mark the given object and, if successful, counts
aoqi@0: // the object in the given task/worker counting structures.
aoqi@0: inline bool ConcurrentMark::par_mark_and_count(oop obj,
aoqi@0:                                                HeapRegion* hr,
aoqi@0:                                                size_t* marked_bytes_array,
aoqi@0:                                                BitMap* task_card_bm) {
aoqi@0:   HeapWord* addr = (HeapWord*)obj;
aoqi@0:   if (_nextMarkBitMap->parMark(addr)) {
aoqi@0:     // Update the task specific count data for the object.
aoqi@0:     count_object(obj, hr, marked_bytes_array, task_card_bm);
aoqi@0:     return true;
aoqi@0:   }
aoqi@0:   return false;
aoqi@0: }
aoqi@0: 
aoqi@0: // Attempts to mark the given object and, if successful, counts
aoqi@0: // the object in the task/worker counting structures for the
aoqi@0: // given worker id.
aoqi@0: inline bool ConcurrentMark::par_mark_and_count(oop obj,
aoqi@0:                                                size_t word_size,
aoqi@0:                                                HeapRegion* hr,
aoqi@0:                                                uint worker_id) {
aoqi@0:   HeapWord* addr = (HeapWord*)obj;
aoqi@0:   if (_nextMarkBitMap->parMark(addr)) {
aoqi@0:     MemRegion mr(addr, word_size);
aoqi@0:     count_region(mr, hr, worker_id);
aoqi@0:     return true;
aoqi@0:   }
aoqi@0:   return false;
aoqi@0: }
aoqi@0: 
aoqi@0: // Attempts to mark the given object and, if successful, counts
aoqi@0: // the object in the task/worker counting structures for the
aoqi@0: // given worker id.
aoqi@0: inline bool ConcurrentMark::par_mark_and_count(oop obj,
aoqi@0:                                                HeapRegion* hr,
aoqi@0:                                                uint worker_id) {
aoqi@0:   HeapWord* addr = (HeapWord*)obj;
aoqi@0:   if (_nextMarkBitMap->parMark(addr)) {
aoqi@0:     // Update the task specific count data for the object.
aoqi@0:     count_object(obj, hr, worker_id);
aoqi@0:     return true;
aoqi@0:   }
aoqi@0:   return false;
aoqi@0: }
aoqi@0: 
aoqi@0: // As above - but we don't know the heap region containing the
aoqi@0: // object and so have to supply it.
aoqi@0: inline bool ConcurrentMark::par_mark_and_count(oop obj, uint worker_id) {
aoqi@0:   HeapWord* addr = (HeapWord*)obj;
aoqi@0:   HeapRegion* hr = _g1h->heap_region_containing_raw(addr);
aoqi@0:   return par_mark_and_count(obj, hr, worker_id);
aoqi@0: }
aoqi@0: 
aoqi@0: // Similar to the above routine but we already know the size, in words, of
aoqi@0: // the object that we wish to mark/count
aoqi@0: inline bool ConcurrentMark::par_mark_and_count(oop obj,
aoqi@0:                                                size_t word_size,
aoqi@0:                                                uint worker_id) {
aoqi@0:   HeapWord* addr = (HeapWord*)obj;
aoqi@0:   if (_nextMarkBitMap->parMark(addr)) {
aoqi@0:     // Update the task specific count data for the object.
aoqi@0:     MemRegion mr(addr, word_size);
aoqi@0:     count_region(mr, worker_id);
aoqi@0:     return true;
aoqi@0:   }
aoqi@0:   return false;
aoqi@0: }
aoqi@0: 
aoqi@0: // Unconditionally mark the given object, and unconditinally count
aoqi@0: // the object in the counting structures for worker id 0.
aoqi@0: // Should *not* be called from parallel code.
aoqi@0: inline bool ConcurrentMark::mark_and_count(oop obj, HeapRegion* hr) {
aoqi@0:   HeapWord* addr = (HeapWord*)obj;
aoqi@0:   _nextMarkBitMap->mark(addr);
aoqi@0:   // Update the task specific count data for the object.
aoqi@0:   count_object(obj, hr, 0 /* worker_id */);
aoqi@0:   return true;
aoqi@0: }
aoqi@0: 
aoqi@0: // As above - but we don't have the heap region containing the
aoqi@0: // object, so we have to supply it.
aoqi@0: inline bool ConcurrentMark::mark_and_count(oop obj) {
aoqi@0:   HeapWord* addr = (HeapWord*)obj;
aoqi@0:   HeapRegion* hr = _g1h->heap_region_containing_raw(addr);
aoqi@0:   return mark_and_count(obj, hr);
aoqi@0: }
aoqi@0: 
aoqi@0: inline bool CMBitMapRO::iterate(BitMapClosure* cl, MemRegion mr) {
aoqi@0:   HeapWord* start_addr = MAX2(startWord(), mr.start());
aoqi@0:   HeapWord* end_addr = MIN2(endWord(), mr.end());
aoqi@0: 
aoqi@0:   if (end_addr > start_addr) {
aoqi@0:     // Right-open interval [start-offset, end-offset).
aoqi@0:     BitMap::idx_t start_offset = heapWordToOffset(start_addr);
aoqi@0:     BitMap::idx_t end_offset = heapWordToOffset(end_addr);
aoqi@0: 
aoqi@0:     start_offset = _bm.get_next_one_offset(start_offset, end_offset);
aoqi@0:     while (start_offset < end_offset) {
aoqi@0:       if (!cl->do_bit(start_offset)) {
aoqi@0:         return false;
aoqi@0:       }
aoqi@0:       HeapWord* next_addr = MIN2(nextObject(offsetToHeapWord(start_offset)), end_addr);
aoqi@0:       BitMap::idx_t next_offset = heapWordToOffset(next_addr);
aoqi@0:       start_offset = _bm.get_next_one_offset(next_offset, end_offset);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return true;
aoqi@0: }
aoqi@0: 
aoqi@0: inline bool CMBitMapRO::iterate(BitMapClosure* cl) {
aoqi@0:   MemRegion mr(startWord(), sizeInWords());
aoqi@0:   return iterate(cl, mr);
aoqi@0: }
aoqi@0: 
aoqi@0: inline void CMTask::push(oop obj) {
aoqi@0:   HeapWord* objAddr = (HeapWord*) obj;
aoqi@0:   assert(_g1h->is_in_g1_reserved(objAddr), "invariant");
aoqi@0:   assert(!_g1h->is_on_master_free_list(
aoqi@0:               _g1h->heap_region_containing((HeapWord*) objAddr)), "invariant");
aoqi@0:   assert(!_g1h->is_obj_ill(obj), "invariant");
aoqi@0:   assert(_nextMarkBitMap->isMarked(objAddr), "invariant");
aoqi@0: 
aoqi@0:   if (_cm->verbose_high()) {
aoqi@0:     gclog_or_tty->print_cr("[%u] pushing " PTR_FORMAT, _worker_id, p2i((void*) obj));
aoqi@0:   }
aoqi@0: 
aoqi@0:   if (!_task_queue->push(obj)) {
aoqi@0:     // The local task queue looks full. We need to push some entries
aoqi@0:     // to the global stack.
aoqi@0: 
aoqi@0:     if (_cm->verbose_medium()) {
aoqi@0:       gclog_or_tty->print_cr("[%u] task queue overflow, "
aoqi@0:                              "moving entries to the global stack",
aoqi@0:                              _worker_id);
aoqi@0:     }
aoqi@0:     move_entries_to_global_stack();
aoqi@0: 
aoqi@0:     // this should succeed since, even if we overflow the global
aoqi@0:     // stack, we should have definitely removed some entries from the
aoqi@0:     // local queue. So, there must be space on it.
aoqi@0:     bool success = _task_queue->push(obj);
aoqi@0:     assert(success, "invariant");
aoqi@0:   }
aoqi@0: 
aoqi@0:   statsOnly( int tmp_size = _task_queue->size();
aoqi@0:              if (tmp_size > _local_max_size) {
aoqi@0:                _local_max_size = tmp_size;
aoqi@0:              }
aoqi@0:              ++_local_pushes );
aoqi@0: }
aoqi@0: 
aoqi@0: // This determines whether the method below will check both the local
aoqi@0: // and global fingers when determining whether to push on the stack a
aoqi@0: // gray object (value 1) or whether it will only check the global one
aoqi@0: // (value 0). The tradeoffs are that the former will be a bit more
aoqi@0: // accurate and possibly push less on the stack, but it might also be
aoqi@0: // a little bit slower.
aoqi@0: 
aoqi@0: #define _CHECK_BOTH_FINGERS_      1
aoqi@0: 
aoqi@0: inline void CMTask::deal_with_reference(oop obj) {
aoqi@0:   if (_cm->verbose_high()) {
aoqi@0:     gclog_or_tty->print_cr("[%u] we're dealing with reference = "PTR_FORMAT,
aoqi@0:                            _worker_id, p2i((void*) obj));
aoqi@0:   }
aoqi@0: 
aoqi@0:   ++_refs_reached;
aoqi@0: 
aoqi@0:   HeapWord* objAddr = (HeapWord*) obj;
aoqi@0:   assert(obj->is_oop_or_null(true /* ignore mark word */), "Error");
aoqi@0:   if (_g1h->is_in_g1_reserved(objAddr)) {
aoqi@0:     assert(obj != NULL, "null check is implicit");
aoqi@0:     if (!_nextMarkBitMap->isMarked(objAddr)) {
aoqi@0:       // Only get the containing region if the object is not marked on the
aoqi@0:       // bitmap (otherwise, it's a waste of time since we won't do
aoqi@0:       // anything with it).
aoqi@0:       HeapRegion* hr = _g1h->heap_region_containing_raw(obj);
aoqi@0:       if (!hr->obj_allocated_since_next_marking(obj)) {
aoqi@0:         if (_cm->verbose_high()) {
aoqi@0:           gclog_or_tty->print_cr("[%u] "PTR_FORMAT" is not considered marked",
aoqi@0:                                  _worker_id, p2i((void*) obj));
aoqi@0:         }
aoqi@0: 
aoqi@0:         // we need to mark it first
aoqi@0:         if (_cm->par_mark_and_count(obj, hr, _marked_bytes_array, _card_bm)) {
aoqi@0:           // No OrderAccess:store_load() is needed. It is implicit in the
aoqi@0:           // CAS done in CMBitMap::parMark() call in the routine above.
aoqi@0:           HeapWord* global_finger = _cm->finger();
aoqi@0: 
aoqi@0: #if _CHECK_BOTH_FINGERS_
aoqi@0:           // we will check both the local and global fingers
aoqi@0: 
aoqi@0:           if (_finger != NULL && objAddr < _finger) {
aoqi@0:             if (_cm->verbose_high()) {
aoqi@0:               gclog_or_tty->print_cr("[%u] below the local finger ("PTR_FORMAT"), "
aoqi@0:                                      "pushing it", _worker_id, p2i(_finger));
aoqi@0:             }
aoqi@0:             push(obj);
aoqi@0:           } else if (_curr_region != NULL && objAddr < _region_limit) {
aoqi@0:             // do nothing
aoqi@0:           } else if (objAddr < global_finger) {
aoqi@0:             // Notice that the global finger might be moving forward
aoqi@0:             // concurrently. This is not a problem. In the worst case, we
aoqi@0:             // mark the object while it is above the global finger and, by
aoqi@0:             // the time we read the global finger, it has moved forward
aoqi@0:             // passed this object. In this case, the object will probably
aoqi@0:             // be visited when a task is scanning the region and will also
aoqi@0:             // be pushed on the stack. So, some duplicate work, but no
aoqi@0:             // correctness problems.
aoqi@0: 
aoqi@0:             if (_cm->verbose_high()) {
aoqi@0:               gclog_or_tty->print_cr("[%u] below the global finger "
aoqi@0:                                      "("PTR_FORMAT"), pushing it",
aoqi@0:                                      _worker_id, p2i(global_finger));
aoqi@0:             }
aoqi@0:             push(obj);
aoqi@0:           } else {
aoqi@0:             // do nothing
aoqi@0:           }
aoqi@0: #else // _CHECK_BOTH_FINGERS_
aoqi@0:           // we will only check the global finger
aoqi@0: 
aoqi@0:           if (objAddr < global_finger) {
aoqi@0:             // see long comment above
aoqi@0: 
aoqi@0:             if (_cm->verbose_high()) {
aoqi@0:               gclog_or_tty->print_cr("[%u] below the global finger "
aoqi@0:                                      "("PTR_FORMAT"), pushing it",
aoqi@0:                                      _worker_id, p2i(global_finger));
aoqi@0:             }
aoqi@0:             push(obj);
aoqi@0:           }
aoqi@0: #endif // _CHECK_BOTH_FINGERS_
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: inline void ConcurrentMark::markPrev(oop p) {
aoqi@0:   assert(!_prevMarkBitMap->isMarked((HeapWord*) p), "sanity");
aoqi@0:   // Note we are overriding the read-only view of the prev map here, via
aoqi@0:   // the cast.
aoqi@0:   ((CMBitMap*)_prevMarkBitMap)->mark((HeapWord*) p);
aoqi@0: }
aoqi@0: 
aoqi@0: inline void ConcurrentMark::grayRoot(oop obj, size_t word_size,
aoqi@0:                                      uint worker_id, HeapRegion* hr) {
aoqi@0:   assert(obj != NULL, "pre-condition");
aoqi@0:   HeapWord* addr = (HeapWord*) obj;
aoqi@0:   if (hr == NULL) {
aoqi@0:     hr = _g1h->heap_region_containing_raw(addr);
aoqi@0:   } else {
aoqi@0:     assert(hr->is_in(addr), "pre-condition");
aoqi@0:   }
aoqi@0:   assert(hr != NULL, "sanity");
aoqi@0:   // Given that we're looking for a region that contains an object
aoqi@0:   // header it's impossible to get back a HC region.
aoqi@0:   assert(!hr->continuesHumongous(), "sanity");
aoqi@0: 
aoqi@0:   // We cannot assert that word_size == obj->size() given that obj
aoqi@0:   // might not be in a consistent state (another thread might be in
aoqi@0:   // the process of copying it). So the best thing we can do is to
aoqi@0:   // assert that word_size is under an upper bound which is its
aoqi@0:   // containing region's capacity.
aoqi@0:   assert(word_size * HeapWordSize <= hr->capacity(),
aoqi@0:          err_msg("size: "SIZE_FORMAT" capacity: "SIZE_FORMAT" "HR_FORMAT,
aoqi@0:                  word_size * HeapWordSize, hr->capacity(),
aoqi@0:                  HR_FORMAT_PARAMS(hr)));
aoqi@0: 
aoqi@0:   if (addr < hr->next_top_at_mark_start()) {
aoqi@0:     if (!_nextMarkBitMap->isMarked(addr)) {
aoqi@0:       par_mark_and_count(obj, word_size, hr, worker_id);
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: #endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_INLINE_HPP