1/*
2 * Copyright (C) 2013 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. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <wtf/FastMalloc.h>
29
30// MallocPtr is a smart pointer class that calls fastFree in its destructor.
31// It is intended to be used for pointers where the C++ lifetime semantics
32// (calling constructors and destructors) is not desired.
33
34namespace WTF {
35
36template<typename T, typename Malloc = FastMalloc> class MallocPtr {
37public:
38 MallocPtr()
39 : m_ptr(nullptr)
40 {
41 }
42
43 MallocPtr(std::nullptr_t)
44 : m_ptr(nullptr)
45 {
46 }
47
48 MallocPtr(MallocPtr&& other)
49 : m_ptr(other.leakPtr())
50 {
51 }
52
53 ~MallocPtr()
54 {
55 Malloc::free(m_ptr);
56 }
57
58 T* get() const
59 {
60 return m_ptr;
61 }
62
63 T *leakPtr() WARN_UNUSED_RETURN
64 {
65 return std::exchange(m_ptr, nullptr);
66 }
67
68 explicit operator bool() const
69 {
70 return m_ptr;
71 }
72
73 bool operator!() const
74 {
75 return !m_ptr;
76 }
77
78 T& operator*() const
79 {
80 ASSERT(m_ptr);
81 return *m_ptr;
82 }
83
84 T* operator->() const
85 {
86 return m_ptr;
87 }
88
89 MallocPtr& operator=(MallocPtr&& other)
90 {
91 MallocPtr ptr = WTFMove(other);
92 swap(ptr);
93
94 return *this;
95 }
96
97 void swap(MallocPtr& other)
98 {
99 std::swap(m_ptr, other.m_ptr);
100 }
101
102 template<typename U> friend MallocPtr<U> adoptMallocPtr(U*);
103
104 static MallocPtr malloc(size_t size)
105 {
106 return MallocPtr { static_cast<T*>(Malloc::malloc(size)) };
107 }
108
109 static MallocPtr tryMalloc(size_t size)
110 {
111 return MallocPtr { static_cast<T*>(Malloc::tryMalloc(size)) };
112 }
113
114 void realloc(size_t newSize)
115 {
116 m_ptr = static_cast<T*>(Malloc::realloc(m_ptr, newSize));
117 }
118
119private:
120 explicit MallocPtr(T* ptr)
121 : m_ptr(ptr)
122 {
123 }
124
125 T* m_ptr;
126};
127
128static_assert(sizeof(MallocPtr<int>) == sizeof(int*), "");
129
130template<typename U> MallocPtr<U> adoptMallocPtr(U* ptr)
131{
132 return MallocPtr<U>(ptr);
133}
134
135} // namespace WTF
136
137using WTF::MallocPtr;
138using WTF::adoptMallocPtr;
139