1/*
2 * Copyright (C) 2017-2018 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#if ENABLE(WEBASSEMBLY)
29
30#include "WasmFormat.h"
31#include "WasmLimits.h"
32#include "WriteBarrier.h"
33#include <wtf/MallocPtr.h>
34#include <wtf/Optional.h>
35#include <wtf/Ref.h>
36#include <wtf/ThreadSafeRefCounted.h>
37
38namespace JSC { namespace Wasm {
39
40class Instance;
41class FuncRefTable;
42
43class Table : public ThreadSafeRefCounted<Table> {
44 WTF_MAKE_NONCOPYABLE(Table);
45 WTF_MAKE_FAST_ALLOCATED(Table);
46public:
47 static RefPtr<Table> tryCreate(uint32_t initial, Optional<uint32_t> maximum, TableElementType);
48
49 JS_EXPORT_PRIVATE ~Table() = default;
50
51 Optional<uint32_t> maximum() const { return m_maximum; }
52 uint32_t length() const { return m_length; }
53
54 static ptrdiff_t offsetOfLength() { return OBJECT_OFFSETOF(Table, m_length); }
55 static ptrdiff_t offsetOfMask() { return OBJECT_OFFSETOF(Table, m_mask); }
56
57 static uint32_t allocatedLength(uint32_t length);
58 uint32_t mask() const { return m_mask; }
59
60 void setOwner(JSObject* owner)
61 {
62 ASSERT(!m_owner);
63 ASSERT(owner);
64 m_owner = owner;
65 }
66
67 TableElementType type() const { return m_type; }
68 bool isAnyrefTable() const { return m_type == TableElementType::Anyref; }
69 FuncRefTable* asFuncrefTable();
70
71 static bool isValidLength(uint32_t length) { return length < maxTableEntries; }
72
73 void clear(uint32_t);
74 void set(uint32_t, JSValue);
75 JSValue get(uint32_t) const;
76
77 Optional<uint32_t> grow(uint32_t delta);
78
79 void visitAggregate(SlotVisitor&);
80
81protected:
82 Table(uint32_t initial, Optional<uint32_t> maximum, TableElementType = TableElementType::Anyref);
83
84 void setLength(uint32_t);
85
86 uint32_t m_length;
87 uint32_t m_mask;
88 const TableElementType m_type;
89 const Optional<uint32_t> m_maximum;
90
91 MallocPtr<WriteBarrier<Unknown>> m_jsValues;
92 JSObject* m_owner;
93};
94
95class FuncRefTable : public Table {
96public:
97 JS_EXPORT_PRIVATE ~FuncRefTable() = default;
98
99 void setFunction(uint32_t, JSObject*, WasmToWasmImportableFunction, Instance*);
100
101 static ptrdiff_t offsetOfFunctions() { return OBJECT_OFFSETOF(FuncRefTable, m_importableFunctions); }
102 static ptrdiff_t offsetOfInstances() { return OBJECT_OFFSETOF(FuncRefTable, m_instances); }
103
104private:
105 FuncRefTable(uint32_t initial, Optional<uint32_t> maximum);
106
107 MallocPtr<WasmToWasmImportableFunction> m_importableFunctions;
108 // call_indirect needs to do an Instance check to potentially context switch when calling a function to another instance. We can hold raw pointers to Instance here because the embedder ensures that Table keeps all the instances alive. We couldn't hold a Ref here because it would cause cycles.
109 MallocPtr<Instance*> m_instances;
110
111 friend class Table;
112};
113
114} } // namespace JSC::Wasm
115
116#endif // ENABLE(WEBASSEMBLY)
117