src/share/vm/gc_implementation/g1/concurrentMark.inline.hpp - platform/external/jetbrains/jdk8u_hotspot - Git at Google

 /*
  * 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
  * questions.
  *
  */

 #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
	/*
	* 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
	* questions.
	*
	*/

	#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