1/*
2 * Copyright (c) 2015, 2019, 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
21 * questions.
22 */
23
24#ifndef SHARE_GC_Z_ZFORWARDING_HPP
25#define SHARE_GC_Z_ZFORWARDING_HPP
26
27#include "gc/z/zAttachedArray.hpp"
28#include "gc/z/zForwardingEntry.hpp"
29#include "gc/z/zVirtualMemory.hpp"
30
31class ZPage;
32
33typedef uint32_t ZForwardingCursor;
34
35class ZForwarding {
36 friend class VMStructs;
37 friend class ZForwardingTest;
38
39private:
40 typedef ZAttachedArray<ZForwarding, ZForwardingEntry> AttachedArray;
41
42 const ZVirtualMemory _virtual;
43 const size_t _object_alignment_shift;
44 const AttachedArray _entries;
45 ZPage* _page;
46 volatile uint32_t _refcount;
47 volatile bool _pinned;
48
49 bool inc_refcount();
50 bool dec_refcount();
51
52 ZForwardingEntry* entries() const;
53 ZForwardingEntry at(ZForwardingCursor* cursor) const;
54 ZForwardingEntry first(uintptr_t from_index, ZForwardingCursor* cursor) const;
55 ZForwardingEntry next(ZForwardingCursor* cursor) const;
56
57 ZForwarding(ZPage* page, uint32_t nentries);
58
59public:
60 static ZForwarding* create(ZPage* page);
61 static void destroy(ZForwarding* forwarding);
62
63 uintptr_t start() const;
64 size_t size() const;
65 size_t object_alignment_shift() const;
66 ZPage* page() const;
67
68 bool is_pinned() const;
69 void set_pinned();
70
71 bool retain_page();
72 void release_page();
73
74 ZForwardingEntry find(uintptr_t from_index) const;
75 ZForwardingEntry find(uintptr_t from_index, ZForwardingCursor* cursor) const;
76 uintptr_t insert(uintptr_t from_index, uintptr_t to_offset, ZForwardingCursor* cursor);
77
78 void verify() const;
79};
80
81#endif // SHARE_GC_Z_ZFORWARDING_HPP
82