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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 *

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 * 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.

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#ifndef SHARE_VM_GC_G1_G1CONCURRENTMARK_INLINE_HPP

#define SHARE_VM_GC_G1_G1CONCURRENTMARK_INLINE_HPP

#include "gc/g1/g1CollectedHeap.inline.hpp"

#include "gc/g1/g1ConcurrentMark.hpp"

#include "gc/g1/suspendibleThreadSet.hpp"

#include "gc/shared/taskqueue.inline.hpp"

inline bool G1ConcurrentMark::par_mark(oop obj) {

  return _nextMarkBitMap->parMark((HeapWord*)obj);

}

inline bool G1CMBitMapRO::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;

}

// The argument addr should be the start address of a valid object

HeapWord* G1CMBitMapRO::nextObject(HeapWord* addr) {

  oop obj = (oop) addr;

  HeapWord* res =  addr + obj->size();

  assert(offsetToHeapWord(heapWordToOffset(res)) == res, "sanity");

  return res;

}

#define check_mark(addr)                                                       \

  assert(_bmStartWord <= (addr) && (addr) < (_bmStartWord + _bmWordSize),      \

         "outside underlying space?");                                         \

  assert(G1CollectedHeap::heap()->is_in_exact(addr),                           \

         "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 G1CMBitMap::mark(HeapWord* addr) {

  check_mark(addr);

  _bm.set_bit(heapWordToOffset(addr));

}

inline void G1CMBitMap::clear(HeapWord* addr) {

  check_mark(addr);

  _bm.clear_bit(heapWordToOffset(addr));

}

inline bool G1CMBitMap::parMark(HeapWord* addr) {

  check_mark(addr);

  return _bm.par_set_bit(heapWordToOffset(addr));

}

#undef check_mark

template<typename Fn>

  assert_at_safepoint(true);

  }

}

// It scans an object and visits its children.

inline void G1CMTask::scan_object(oop obj) { process_grey_object<true>(obj); }

inline void G1CMTask::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 (!_task_queue->push(obj)) {

    // The local task queue looks full. We need to push some entries

    // to the global stack.

    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");

  }

}

inline bool G1CMTask::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;

}

template<bool scan>

inline void G1CMTask::process_grey_object(oop obj) {

  assert(scan || obj->is_typeArray(), "Skipping scan of grey non-typeArray");

  assert(_nextMarkBitMap->isMarked((HeapWord*) obj), "invariant");

  size_t obj_size = obj->size();

  _words_scanned += obj_size;

  if (scan) {

    obj->oop_iterate(_cm_oop_closure);

  }

  check_limits();

}

inline void G1CMTask::make_reference_grey(oop obj) {

  if (_cm->par_mark(obj)) {

    // No OrderAccess:store_load() is needed. It is implicit in the

    // CAS done in G1CMBitMap::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 {

        push(obj);

      }

    }

  }

}

inline void G1CMTask::deal_with_reference(oop obj) {

  increment_refs_reached();

  HeapWord* objAddr = (HeapWord*) obj;

  assert(obj->is_oop_or_null(true /* ignore mark word */), "Expected an oop or NULL at " PTR_FORMAT, p2i(obj));

  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(obj);

      if (!hr->obj_allocated_since_next_marking(obj)) {

        make_reference_grey(obj);

      }

    }

  }

}

inline void G1ConcurrentMark::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.

  ((G1CMBitMap*)_prevMarkBitMap)->mark((HeapWord*) p);

}

bool G1ConcurrentMark::isPrevMarked(oop p) const {

  assert(p != NULL && p->is_oop(), "expected an oop");

  HeapWord* addr = (HeapWord*)p;

  assert(addr >= _prevMarkBitMap->startWord() ||

         addr < _prevMarkBitMap->endWord(), "in a region");

  return _prevMarkBitMap->isMarked(addr);

}

inline void G1ConcurrentMark::grayRoot(oop obj, HeapRegion* hr) {

  assert(obj != NULL, "pre-condition");

  HeapWord* addr = (HeapWord*) obj;

  if (hr == NULL) {

    hr = _g1h->heap_region_containing(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->is_continues_humongous(), "sanity");

  if (addr < hr->next_top_at_mark_start()) {

    if (!_nextMarkBitMap->isMarked(addr)) {

      par_mark(obj);

    }

  }

}

inline bool G1ConcurrentMark::do_yield_check() {

  if (SuspendibleThreadSet::should_yield()) {

    SuspendibleThreadSet::yield();

    return true;

  } else {

    return false;

  }

}

#endif // SHARE_VM_GC_G1_G1CONCURRENTMARK_INLINE_HPP