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 <wtf/MallocPtr.h>
33#include <wtf/Optional.h>
34#include <wtf/Ref.h>
35#include <wtf/ThreadSafeRefCounted.h>
36
37namespace JSC { namespace Wasm {
38
39class Instance;
40
41class Table : public ThreadSafeRefCounted<Table> {
42public:
43 static RefPtr<Table> tryCreate(uint32_t initial, Optional<uint32_t> maximum);
44
45 JS_EXPORT_PRIVATE ~Table();
46
47 Optional<uint32_t> maximum() const { return m_maximum; }
48 uint32_t length() const { return m_length; }
49 Optional<uint32_t> grow(uint32_t delta) WARN_UNUSED_RETURN;
50 void clearFunction(uint32_t);
51 void setFunction(uint32_t, WasmToWasmImportableFunction, Instance*);
52
53 static ptrdiff_t offsetOfFunctions() { return OBJECT_OFFSETOF(Table, m_importableFunctions); }
54 static ptrdiff_t offsetOfInstances() { return OBJECT_OFFSETOF(Table, m_instances); }
55 static ptrdiff_t offsetOfLength() { return OBJECT_OFFSETOF(Table, m_length); }
56 static ptrdiff_t offsetOfMask() { return OBJECT_OFFSETOF(Table, m_mask); }
57
58 static uint32_t allocatedLength(uint32_t length);
59 uint32_t mask() const { return m_mask; }
60 static bool isValidLength(uint32_t length) { return length < maxTableEntries; }
61
62private:
63 Table(uint32_t initial, Optional<uint32_t> maximum);
64
65 void setLength(uint32_t);
66
67 MallocPtr<WasmToWasmImportableFunction> m_importableFunctions;
68 // 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.
69 MallocPtr<Instance*> m_instances;
70 uint32_t m_length;
71 uint32_t m_mask;
72 Optional<uint32_t> m_maximum;
73};
74
75} } // namespace JSC::Wasm
76
77#endif // ENABLE(WEBASSEMBLY)
78