1/*
2 * Copyright (C) 2018 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 "IsoSubspace.h"
29#include <wtf/Function.h>
30#include <wtf/HashMap.h>
31#include <wtf/Lock.h>
32
33namespace JSC {
34
35// This is an appropriate way to stash IsoSubspaces for rarely-used classes or classes that are mostly
36// sure to be main-thread-only. But if a class typically gets instantiated from multiple threads at
37// once, then this is not great, because concurrent allocations will probably contend on this thing's
38// lock.
39class IsoSubspacePerVM {
40public:
41 struct SubspaceParameters {
42 SubspaceParameters() { }
43
44 SubspaceParameters(CString name, HeapCellType* heapCellType, size_t size)
45 : name(WTFMove(name))
46 , heapCellType(heapCellType)
47 , size(size)
48 {
49 }
50
51 CString name;
52 HeapCellType* heapCellType { nullptr };
53 size_t size { 0 };
54 };
55
56 JS_EXPORT_PRIVATE IsoSubspacePerVM(Function<SubspaceParameters(VM&)>);
57 JS_EXPORT_PRIVATE ~IsoSubspacePerVM();
58
59 JS_EXPORT_PRIVATE IsoSubspace& forVM(VM&);
60
61private:
62 class AutoremovingIsoSubspace;
63 friend class AutoremovingIsoSubspace;
64
65 Lock m_lock;
66 HashMap<VM*, IsoSubspace*> m_subspacePerVM;
67 Function<SubspaceParameters(VM&)> m_subspaceParameters;
68};
69
70#define ISO_SUBSPACE_PARAMETERS(heapCellType, type) ::JSC::IsoSubspacePerVM::SubspaceParameters("Isolated " #type " Space", (heapCellType), sizeof(type))
71
72} // namespace JSC
73
74