src/hotspot/share/oops/refArrayOop.hpp - master - githubmirror/panama-vector

src/hotspot/share/oops/refArrayOop.hpp
93 строки3 KB
David Simms
8389219: Implement JEP 401: Value Objects (Preview)
31 июл 2026, 03:45
31 июл 2026, 03:45cc278db
/*
 * Copyright (c) 2025, 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
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 */

#ifndef SHARE_OOPS_REFARRAYOOP_HPP
#define SHARE_OOPS_REFARRAYOOP_HPP

#include "oops/objArrayOop.hpp"
#include "utilities/align.hpp"

class RefArrayKlass;

// A refArrayOop is an array containing references (oops).
// Evaluating "String arg[10]" will create a refArrayOop.

class refArrayOopDesc : public objArrayOopDesc {
  friend class ArchiveHeapWriter;
  friend class RefArrayKlass;
  friend class Runtime1;
  friend class psPromotionManager;
  friend class CSetMarkWordClosure;
  friend class Continuation;
  template <typename T>
  friend class RawOopWriter;
  friend class AOTMapLogger;

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

  template <class T>
  static ptrdiff_t obj_at_offset(int index) {
    return base_offset_in_bytes() + sizeof(T) * index;
  }

 public:
  inline RefArrayKlass* klass() const;

  // Returns the offset of the first element.
  static int base_offset_in_bytes() {
    return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
  }

  // base is the address following the header.
  inline HeapWord* base() const;

  // Accessing
  oop obj_at(int index) const;

  void obj_at_put(int index, oop value);
  void obj_at_put(int index, oop value, TRAPS);

  oop replace_if_null(int index, oop exchange_value);

  // Sizing
  size_t object_size() { return object_size(length()); }

  static size_t object_size(int length) {
    // This returns the object size in HeapWords.
    size_t asz = (size_t)length * heapOopSize;
    size_t size_words = heap_word_size(base_offset_in_bytes() + asz);
    size_t osz = align_object_size(size_words);
    assert(osz < max_jint, "no overflow");
    return osz;
  }

  // special iterators for index ranges, returns size of object
  template <typename OopClosureType>
  void oop_iterate_elements_range(OopClosureType* blk, int start, int end);
};

// See similar requirement for oopDesc.
static_assert(std::is_trivially_default_constructible<refArrayOopDesc>::value, "required");

#endif // SHARE_OOPS_REFARRAYOOP_HPP