src/hotspot/share/oops/instanceOop.hpp - master - githubmirror/jdk22

src/hotspot/share/oops/instanceOop.hpp

51 строка2 KB

Kim Barrett

8274322: Problems with oopDesc construction

01 окт 2021, 03:25

01 окт 2021, 03:252e690ba

/*
 * Copyright (c) 1997, 2021, 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
 * questions.
 *
 */

#ifndef SHARE_OOPS_INSTANCEOOP_HPP
#define SHARE_OOPS_INSTANCEOOP_HPP

#include "oops/oop.hpp"
#include <type_traits>

// An instanceOop is an instance of a Java Class
// Evaluating "new HashTable()" will create an instanceOop.

class instanceOopDesc : public oopDesc {
 public:
  // aligned header size.
  static int header_size() { return sizeof(instanceOopDesc)/HeapWordSize; }

  // If compressed, the offset of the fields of the instance may not be aligned.
  static int base_offset_in_bytes() {
    return (UseCompressedClassPointers) ?
            klass_gap_offset_in_bytes() :
            sizeof(instanceOopDesc);

  }
};

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

#endif // SHARE_OOPS_INSTANCEOOP_HPP