1/*
2 * Copyright (C) 2013 Google 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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef WTF_DefaultAllocator_h
32#define WTF_DefaultAllocator_h
33
34// This is the allocator that is used for allocations that are not on the
35// traced, garbage collected heap. It uses FastMalloc for collections,
36// but uses the partition allocator for the backing store of the collections.
37
38#include "wtf/Assertions.h"
39#include "wtf/FastAllocBase.h"
40#include "wtf/PartitionAlloc.h"
41#include "wtf/WTF.h"
42
43#include <string.h>
44
45namespace WTF {
46
47class DefaultAllocatorDummyVisitor;
48
49class DefaultAllocatorQuantizer {
50public:
51    template<typename T>
52    static size_t quantizedSize(size_t count)
53    {
54        RELEASE_ASSERT(count <= kMaxUnquantizedAllocation / sizeof(T));
55        return partitionAllocActualSize(Partitions::getBufferPartition(), count * sizeof(T));
56    }
57    static const size_t kMaxUnquantizedAllocation = kGenericMaxDirectMapped;
58};
59
60class DefaultAllocator {
61public:
62    typedef DefaultAllocatorQuantizer Quantizer;
63    typedef DefaultAllocatorDummyVisitor Visitor;
64    static const bool isGarbageCollected = false;
65    template<typename T, typename Traits>
66    struct VectorBackingHelper {
67        typedef void Type;
68    };
69    template<typename T>
70    struct HashTableBackingHelper {
71        typedef void Type;
72    };
73    template <typename Return, typename Metadata>
74    static Return backingMalloc(size_t size)
75    {
76        return reinterpret_cast<Return>(backingAllocate(size));
77    }
78    template <typename Return, typename Metadata>
79    static Return zeroedBackingMalloc(size_t size)
80    {
81        void* result = backingAllocate(size);
82        memset(result, 0, size);
83        return reinterpret_cast<Return>(result);
84    }
85    template <typename Return, typename Metadata>
86    static Return malloc(size_t size)
87    {
88        return reinterpret_cast<Return>(fastMalloc(size));
89    }
90    WTF_EXPORT static void backingFree(void* address);
91    static void free(void* address)
92    {
93        fastFree(address);
94    }
95    template<typename T>
96    static void* newArray(size_t bytes)
97    {
98        return malloc<void*, void>(bytes);
99    }
100    static void
101    deleteArray(void* ptr)
102    {
103        free(ptr); // Not the system free, the one from this class.
104    }
105
106    static bool isAllocationAllowed() { return true; }
107
108    static void markNoTracing(...)
109    {
110        ASSERT_NOT_REACHED();
111    }
112
113    static void registerDelayedMarkNoTracing(...)
114    {
115        ASSERT_NOT_REACHED();
116    }
117
118    static void registerWeakMembers(...)
119    {
120        ASSERT_NOT_REACHED();
121    }
122
123    static void registerWeakTable(...)
124    {
125        ASSERT_NOT_REACHED();
126    }
127
128#if ENABLE(ASSERT)
129    static bool weakTableRegistered(...)
130    {
131        ASSERT_NOT_REACHED();
132        return false;
133    }
134#endif
135
136    template<typename T, typename Traits>
137    static void trace(...)
138    {
139        ASSERT_NOT_REACHED();
140    }
141
142    template<typename T>
143    struct OtherType {
144        typedef T* Type;
145    };
146
147    template<typename T>
148    static T& getOther(T* other)
149    {
150        return *other;
151    }
152
153    static void enterNoAllocationScope() { }
154    static void leaveNoAllocationScope() { }
155
156private:
157    WTF_EXPORT static void* backingAllocate(size_t);
158};
159
160// The Windows compiler seems to be very eager to instantiate things it won't
161// need, so unless we have this class we get compile errors.
162class DefaultAllocatorDummyVisitor {
163public:
164    template<typename T> inline bool isAlive(T obj)
165    {
166        ASSERT_NOT_REACHED();
167        return false;
168    }
169};
170
171} // namespace WTF
172
173#define WTF_USE_ALLOCATOR(ClassName, Allocator) \
174public: \
175    void* operator new(size_t size) \
176    { \
177        return Allocator::template malloc<void*, ClassName>(size); \
178    } \
179    void operator delete(void* p) { Allocator::free(p); } \
180    void* operator new[](size_t size) { return Allocator::template newArray<ClassName>(size); } \
181    void operator delete[](void* p) { Allocator::deleteArray(p); } \
182    void* operator new(size_t, NotNullTag, void* location) \
183    { \
184        ASSERT(location); \
185        return location; \
186    } \
187private: \
188typedef int __thisIsHereToForceASemicolonAfterThisMacro
189
190using WTF::DefaultAllocator;
191
192#endif // WTF_DefaultAllocator_h
193