/*

 * Copyright 1997-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

// An objArrayOop is an array containing oops.

// Evaluating "String arg[10]" will create an objArrayOop.

class objArrayOopDesc : public arrayOopDesc {

  friend class objArrayKlass;

  friend class Runtime1;

  friend class psPromotionManager;

  friend class CSMarkOopClosure;

  friend class G1ParScanPartialArrayClosure;

  template <class T> T* obj_at_addr(int index) const {

    assert(is_within_bounds(index), "index out of bounds");

    return &((T*)base())[index];

  }

 public:

  // base is the address following the header.

  HeapWord* base() const      { return (HeapWord*) arrayOopDesc::base(T_OBJECT); }

  // Accessing

  oop obj_at(int index) const {

    // With UseCompressedOops decode the narrow oop in the objArray to an

    // uncompressed oop.  Otherwise this is simply a "*" operator.

    if (UseCompressedOops) {

      return load_decode_heap_oop(obj_at_addr<narrowOop>(index));

    } else {

      return load_decode_heap_oop(obj_at_addr<oop>(index));

    }

  }

  void obj_at_put(int index, oop value) {

    if (UseCompressedOops) {

      oop_store(obj_at_addr<narrowOop>(index), value);

    } else {

      oop_store(obj_at_addr<oop>(index), value);

    }

  }

  // Sizing

  static int header_size()    { return arrayOopDesc::header_size(T_OBJECT); }

  int object_size()           { return object_size(length()); }

  int array_size()            { return array_size(length()); }

  static int object_size(int length) {

    // This returns the object size in HeapWords.

    return align_object_size(header_size() + array_size(length));

  }

  // Give size of objArrayOop in HeapWords minus the header

  static int array_size(int length) {

    // Without UseCompressedOops, this is simply:

    // oop->length() * HeapWordsPerOop;

    // With narrowOops, HeapWordsPerOop is 1/2 or equal 0 as an integer.

    // The oop elements are aligned up to wordSize

    const int HeapWordsPerOop = heapOopSize/HeapWordSize;

    if (HeapWordsPerOop > 0) {

      return length * HeapWordsPerOop;

    } else {

      const int OopsPerHeapWord = HeapWordSize/heapOopSize;

      int word_len = align_size_up(length, OopsPerHeapWord)/OopsPerHeapWord;

      return word_len;

    }

  }

  // special iterators for index ranges, returns size of object

#define ObjArrayOop_OOP_ITERATE_DECL(OopClosureType, nv_suffix)     \

  int oop_iterate_range(OopClosureType* blk, int start, int end);

  ALL_OOP_OOP_ITERATE_CLOSURES_1(ObjArrayOop_OOP_ITERATE_DECL)

  ALL_OOP_OOP_ITERATE_CLOSURES_2(ObjArrayOop_OOP_ITERATE_DECL)

};