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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_G1BLOCKOFFSETTABLE_INLINE_HPP

#define SHARE_VM_GC_G1_G1BLOCKOFFSETTABLE_INLINE_HPP

#include "gc/g1/g1BlockOffsetTable.hpp"

#include "gc/g1/heapRegion.hpp"

#include "gc/shared/memset_with_concurrent_readers.hpp"

#include "gc/shared/space.hpp"

inline HeapWord* G1BlockOffsetTablePart::block_start(const void* addr) {

  if (addr >= _space->bottom() && addr < _space->end()) {

    HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);

    return forward_to_block_containing_addr(q, addr);

  } else {

    return NULL;

  }

}

inline HeapWord* G1BlockOffsetTablePart::block_start_const(const void* addr) const {

  if (addr >= _space->bottom() && addr < _space->end()) {

    HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);

    HeapWord* n = q + block_size(q);

    return forward_to_block_containing_addr_const(q, n, addr);

  } else {

    return NULL;

  }

}

u_char G1BlockOffsetTable::offset_array(size_t index) const {

  check_index(index, "index out of range");

  return _offset_array[index];

}

void G1BlockOffsetTable::set_offset_array(size_t index, u_char offset) {

  check_index(index, "index out of range");

  set_offset_array_raw(index, offset);

}

void G1BlockOffsetTable::set_offset_array(size_t index, HeapWord* high, HeapWord* low) {

  check_index(index, "index out of range");

  assert(high >= low, "addresses out of order");

  size_t offset = pointer_delta(high, low);

  check_offset(offset, "offset too large");

  set_offset_array(index, (u_char)offset);

}

void G1BlockOffsetTable::set_offset_array(size_t left, size_t right, u_char offset) {

  check_index(right, "right index out of range");

  assert(left <= right, "indexes out of order");

  size_t num_cards = right - left + 1;

  memset_with_concurrent_readers(&_offset_array[left], offset, num_cards);

}

// Variant of index_for that does not check the index for validity.

inline size_t G1BlockOffsetTable::index_for_raw(const void* p) const {

  return pointer_delta((char*)p, _reserved.start(), sizeof(char)) >> BOTConstants::LogN;

}

inline size_t G1BlockOffsetTable::index_for(const void* p) const {

  char* pc = (char*)p;

  assert(pc >= (char*)_reserved.start() &&

         pc <  (char*)_reserved.end(),

         "p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")",

         p2i(p), p2i(_reserved.start()), p2i(_reserved.end()));

  size_t result = index_for_raw(p);

  check_index(result, "bad index from address");

  return result;

}

inline HeapWord* G1BlockOffsetTable::address_for_index(size_t index) const {

  check_index(index, "index out of range");

  HeapWord* result = address_for_index_raw(index);

  assert(result >= _reserved.start() && result < _reserved.end(),

         "bad address from index result " PTR_FORMAT

         " _reserved.start() " PTR_FORMAT " _reserved.end() " PTR_FORMAT,

         p2i(result), p2i(_reserved.start()), p2i(_reserved.end()));

  return result;

}

inline size_t G1BlockOffsetTablePart::block_size(const HeapWord* p) const {

  return _space->block_size(p);

}

inline HeapWord* G1BlockOffsetTablePart::block_at_or_preceding(const void* addr,

                                                               bool has_max_index,

                                                               size_t max_index) const {

  assert(_bot->offset_array(0) == 0, "objects can't cross covered areas");

  size_t index = _bot->index_for(addr);

  // We must make sure that the offset table entry we use is valid.  If

  // "addr" is past the end, start at the last known one and go forward.

  if (has_max_index) {

    index = MIN2(index, max_index);

  }

  HeapWord* q = _bot->address_for_index(index);

  uint offset = _bot->offset_array(index);  // Extend u_char to uint.

  while (offset >= BOTConstants::N_words) {

    // The excess of the offset from N_words indicates a power of Base

    // to go back by.

    size_t n_cards_back = BOTConstants::entry_to_cards_back(offset);

    q -= (BOTConstants::N_words * n_cards_back);

    index -= n_cards_back;

    offset = _bot->offset_array(index);

  }

  assert(offset < BOTConstants::N_words, "offset too large");

  q -= offset;

  return q;

}

inline HeapWord* G1BlockOffsetTablePart::forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,

                                                                                const void* addr) const {

  if (addr >= _space->top()) return _space->top();

  while (n <= addr) {

    q = n;

    oop obj = oop(q);

    if (obj->klass_or_null() == NULL) {

      return q;

    }

    n += block_size(q);

  }

  assert(q <= n, "wrong order for q and addr");

  assert(addr < n, "wrong order for addr and n");

  return q;

}

inline HeapWord* G1BlockOffsetTablePart::forward_to_block_containing_addr(HeapWord* q,

                                                                          const void* addr) {

  if (oop(q)->klass_or_null() == NULL) {

    return q;

  }

  HeapWord* n = q + block_size(q);

  // In the normal case, where the query "addr" is a card boundary, and the

  // offset table chunks are the same size as cards, the block starting at

  // "q" will contain addr, so the test below will fail, and we'll fall

  // through quickly.

  if (n <= addr) {

    q = forward_to_block_containing_addr_slow(q, n, addr);

  }

  assert(q <= addr, "wrong order for current and arg");

  return q;

}

#endif // SHARE_VM_GC_G1_G1BLOCKOFFSETTABLE_INLINE_HPP