1/*
2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25#ifndef SHARE_VM_OOPS_OOPHANDLE_HPP
26#define SHARE_VM_OOPS_OOPHANDLE_HPP
27
28#include "oops/oop.hpp"
29#include "runtime/atomic.hpp"
30#include "runtime/orderAccess.hpp"
31
32// Simple class for encapsulating oop pointers stored in metadata.
33// These are different from Handle.  The Handle class stores pointers
34// to oops on the stack, and manages the allocation from a thread local
35// area in the constructor.
36// This assumes that the caller will allocate the handle in the appropriate
37// area.  The reason for the encapsulation is to help with naming and to allow
38// future uses for read barriers.
39
40class OopHandle {
41private:
42  oop* _obj;
43
44public:
45  OopHandle() : _obj(NULL) {}
46  OopHandle(oop* w) : _obj(w) {}
47
48  oop resolve() const { return (_obj == NULL) ? (oop)NULL : *_obj; }
49
50  // Used only for removing handle.
51  oop* ptr_raw() { return _obj; }
52};
53
54#endif // SHARE_VM_OOPS_OOPHANDLE_HPP
55