1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include "BMalloced.h"
29
30namespace bmalloc {
31
32class IsoTLS;
33class IsoTLSLayout;
34
35class BEXPORT IsoTLSEntry {
36 MAKE_BMALLOCED;
37public:
38 IsoTLSEntry(size_t alignment, size_t size);
39 virtual ~IsoTLSEntry();
40
41 size_t offset() const { return m_offset; }
42 size_t alignment() const { return m_alignment; }
43 size_t size() const { return m_size; }
44 size_t extent() const { return m_offset + m_size; }
45
46 virtual void construct(void* entry) = 0;
47 virtual void move(void* src, void* dst) = 0;
48 virtual void destruct(void* entry) = 0;
49 virtual void scavenge(void* entry) = 0;
50
51 template<typename Func>
52 void walkUpToInclusive(IsoTLSEntry*, const Func&);
53
54private:
55 friend class IsoTLS;
56 friend class IsoTLSLayout;
57
58 IsoTLSEntry* m_next { nullptr };
59
60 size_t m_offset; // Computed in constructor.
61 size_t m_alignment;
62 size_t m_size;
63};
64
65template<typename EntryType>
66class DefaultIsoTLSEntry : public IsoTLSEntry {
67public:
68 DefaultIsoTLSEntry();
69 ~DefaultIsoTLSEntry();
70
71protected:
72 // This clones src onto dst and then destructs src. Therefore, entry destructors cannot do
73 // scavenging.
74 void move(void* src, void* dst) override;
75
76 // Likewise, this is separate from scavenging. When the TLS is shutting down, we will be asked to
77 // scavenge and then we will be asked to destruct.
78 void destruct(void* entry) override;
79
80 void scavenge(void* entry) override;
81};
82
83} // namespace bmalloc
84
85