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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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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"

// 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;
  HeapWord* start = mr.start();
  HeapWord* last = mr.last();
  size_t region_size = mr.byte_size();
  size_t index = hr->hrs_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;

  // 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 start_card_num = intptr_t(uintptr_t(start) >> CardTableModRefBS::card_shift);
  intptr_t last_card_num  = intptr_t(uintptr_t(last) >> CardTableModRefBS::card_shift);

  BitMap::idx_t start_idx = start_card_num - heap_bottom_card_num();
  BitMap::idx_t last_idx = last_card_num - heap_bottom_card_num();
  
  // The card bitmap is task/worker specific => no need to use 'par' routines.
  // Set bits in the inclusive bit range [start_idx, last_idx].
  for (BitMap::idx_t i = start_idx; i <= last_idx; i += 1) {
    task_card_bm->set_bit(i);
  }
}

// Counts the given memory region in the ask/worker counting
// data structures for the given worker id.
inline void ConcurrentMark::count_region(MemRegion mr, int worker_i) {
  size_t* marked_bytes_array = count_marked_bytes_array_for(worker_i);
  BitMap* task_card_bm = count_card_bitmap_for(worker_i);
  HeapWord* addr = mr.start();
  HeapRegion* hr = _g1h->heap_region_containing(addr);
  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);
}

// Counts the given object in the task/worker counting data
// structures for the given worker id.
inline void ConcurrentMark::count_object(oop obj, HeapRegion* hr, int worker_i) {
  size_t* marked_bytes_array = count_marked_bytes_array_for(worker_i);
  BitMap* task_card_bm = count_card_bitmap_for(worker_i);
  HeapWord* addr = (HeapWord*) obj;
  count_object(obj, 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,
                                               HeapRegion* hr,
                                               int worker_i) {
  HeapWord* addr = (HeapWord*)obj;
  if (_nextMarkBitMap->parMark(addr)) {
    // Update the task specific count data for the object.
    count_object(obj, hr, worker_i);
    return true;
  }
  return false;
}

// As above - but we don't know the heap region containing the
// object and so have to supply it.
inline bool ConcurrentMark::par_mark_and_count(oop obj, int worker_i) {
  HeapWord* addr = (HeapWord*)obj;
  HeapRegion* hr = _g1h->heap_region_containing(addr);
  return par_mark_and_count(obj, hr, worker_i);
}

// Unconditionally mark the given object, and unconditinally count
// the object in the counting structures for worker id 0.
// Should *not* be called from parallel code.
inline bool ConcurrentMark::mark_and_count(oop obj, HeapRegion* hr) {
  HeapWord* addr = (HeapWord*)obj;
  _nextMarkBitMap->mark(addr);
  // Update the task specific count data for the object.
  count_object(obj, hr, 0 /* worker_i */);
  return true;
}

// As above - but we don't have the heap region containing the
// object, so we have to supply it.
inline bool ConcurrentMark::mark_and_count(oop obj) {
  HeapWord* addr = (HeapWord*)obj;
  HeapRegion* hr = _g1h->heap_region_containing(addr);
  return mark_and_count(obj, hr);
}

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("[%d] pushing "PTR_FORMAT, _task_id, (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("[%d] task queue overflow, "
                             "moving entries to the global stack",
                             _task_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 );
}

// This determines whether the method below will check both the local
// and global fingers when determining whether to push on the stack a
// gray object (value 1) or whether it will only check the global one
// (value 0). The tradeoffs are that the former will be a bit more
// accurate and possibly push less on the stack, but it might also be
// a little bit slower.

#define _CHECK_BOTH_FINGERS_      1

inline void CMTask::deal_with_reference(oop obj) {
  if (_cm->verbose_high()) {
    gclog_or_tty->print_cr("[%d] we're dealing with reference = "PTR_FORMAT,
                           _task_id, (void*) obj);
  }

  ++_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)) {
        if (_cm->verbose_high()) {
          gclog_or_tty->print_cr("[%d] "PTR_FORMAT" is not considered marked",
                                 _task_id, (void*) obj);
        }

        // we need to mark it first
        if (_cm->par_mark_and_count(obj, hr, _marked_bytes_array, _card_bm)) {
          // 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();

#if _CHECK_BOTH_FINGERS_
          // we will check both the local and global fingers

          if (_finger != NULL && objAddr < _finger) {
            if (_cm->verbose_high()) {
              gclog_or_tty->print_cr("[%d] below the local finger ("PTR_FORMAT"), "
                                     "pushing it", _task_id, _finger);
            }
            push(obj);
          } else if (_curr_region != NULL && objAddr < _region_limit) {
            // do nothing
          } else if (objAddr < global_finger) {
            // 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
            // passed 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 (_cm->verbose_high()) {
              gclog_or_tty->print_cr("[%d] below the global finger "
                                     "("PTR_FORMAT"), pushing it",
                                     _task_id, global_finger);
            }
            push(obj);
          } else {
            // do nothing
          }
#else // _CHECK_BOTH_FINGERS_
          // we will only check the global finger

          if (objAddr < global_finger) {
            // see long comment above

            if (_cm->verbose_high()) {
              gclog_or_tty->print_cr("[%d] below the global finger "
                                     "("PTR_FORMAT"), pushing it",
                                     _task_id, global_finger);
            }
            push(obj);
          }
#endif // _CHECK_BOTH_FINGERS_
        }
      }
    }
  }
}

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_INLINE_HPP