1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
/*
* Copyright (C) 2009, 2012 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef Weak_h
#define Weak_h
#include "PassWeak.h"
#include "WeakSetInlines.h"
#include <wtf/Assertions.h>
#include <wtf/HashMap.h>
namespace JSC {
template<typename T> class Weak : public WeakImplAccessor<Weak<T>, T> {
WTF_MAKE_NONCOPYABLE(Weak);
public:
friend class WeakImplAccessor<Weak<T>, T>;
typedef typename WeakImplAccessor<Weak<T>, T>::GetType GetType;
Weak();
Weak(std::nullptr_t);
Weak(GetType, WeakHandleOwner* = 0, void* context = 0);
enum HashTableDeletedValueTag { HashTableDeletedValue };
bool isHashTableDeletedValue() const;
Weak(HashTableDeletedValueTag);
template<typename U> Weak(const PassWeak<U>&);
~Weak();
void swap(Weak&);
Weak& operator=(const PassWeak<T>&);
bool operator!() const;
// This conversion operator allows implicit conversion to bool but not to other integer types.
typedef JSValue (HandleBase::*UnspecifiedBoolType);
operator UnspecifiedBoolType*() const;
PassWeak<T> release();
void clear();
private:
static WeakImpl* hashTableDeletedValue();
WeakImpl* m_impl;
};
template<typename T> inline Weak<T>::Weak()
: m_impl(0)
{
}
template<typename T> inline Weak<T>::Weak(std::nullptr_t)
: m_impl(0)
{
}
template<typename T> inline Weak<T>::Weak(typename Weak<T>::GetType getType, WeakHandleOwner* weakOwner, void* context)
: m_impl(getType ? WeakSet::allocate(getType, weakOwner, context) : 0)
{
}
template<typename T> inline bool Weak<T>::isHashTableDeletedValue() const
{
return m_impl == hashTableDeletedValue();
}
template<typename T> inline Weak<T>::Weak(typename Weak<T>::HashTableDeletedValueTag)
: m_impl(hashTableDeletedValue())
{
}
template<typename T> template<typename U> inline Weak<T>::Weak(const PassWeak<U>& other)
: m_impl(other.leakImpl())
{
}
template<typename T> inline Weak<T>::~Weak()
{
clear();
}
template<class T> inline void swap(Weak<T>& a, Weak<T>& b)
{
a.swap(b);
}
template<typename T> inline void Weak<T>::swap(Weak& other)
{
std::swap(m_impl, other.m_impl);
}
template<typename T> inline Weak<T>& Weak<T>::operator=(const PassWeak<T>& o)
{
clear();
m_impl = o.leakImpl();
return *this;
}
template<typename T> inline bool Weak<T>::operator!() const
{
return !m_impl || !m_impl->jsValue() || m_impl->state() != WeakImpl::Live;
}
template<typename T> inline Weak<T>::operator UnspecifiedBoolType*() const
{
return reinterpret_cast<UnspecifiedBoolType*>(!!*this);
}
template<typename T> inline PassWeak<T> Weak<T>::release()
{
PassWeak<T> tmp = adoptWeak<T>(m_impl);
m_impl = 0;
return tmp;
}
template<typename T> inline void Weak<T>::clear()
{
if (!m_impl)
return;
WeakSet::deallocate(m_impl);
m_impl = 0;
}
template<typename T> inline WeakImpl* Weak<T>::hashTableDeletedValue()
{
return reinterpret_cast<WeakImpl*>(-1);
}
template <typename T> inline bool operator==(const Weak<T>& lhs, const Weak<T>& rhs)
{
return lhs.get() == rhs.get();
}
// This function helps avoid modifying a weak table while holding an iterator into it. (Object allocation
// can run a finalizer that modifies the table. We avoid that by requiring a pre-constructed object as our value.)
template<typename Map, typename Key, typename Value> inline void weakAdd(Map& map, const Key& key, Value value)
{
ASSERT(!map.get(key));
map.set(key, value); // The table may still have a zombie for value.
}
template<typename Map, typename Key, typename Value> inline void weakRemove(Map& map, const Key& key, Value value)
{
typename Map::iterator it = map.find(key);
ASSERT_UNUSED(value, value);
ASSERT(it != map.end());
ASSERT(it->value.was(value));
ASSERT(!it->value);
map.remove(it);
}
template<typename T> inline void weakClear(Weak<T>& weak, typename Weak<T>::GetType value)
{
ASSERT_UNUSED(value, value);
ASSERT(weak.was(value));
ASSERT(!weak);
weak.clear();
}
} // namespace JSC
namespace WTF {
template<typename T> struct VectorTraits<JSC::Weak<T> > : SimpleClassVectorTraits {
static const bool canCompareWithMemcmp = false;
};
template<typename T> struct HashTraits<JSC::Weak<T> > : SimpleClassHashTraits<JSC::Weak<T> > {
typedef JSC::Weak<T> StorageType;
typedef std::nullptr_t EmptyValueType;
static EmptyValueType emptyValue() { return nullptr; }
typedef JSC::PassWeak<T> PassInType;
static void store(PassInType value, StorageType& storage) { storage = value; }
typedef JSC::PassWeak<T> PassOutType;
static PassOutType passOut(StorageType& value) { return value.release(); }
static PassOutType passOut(EmptyValueType) { return PassOutType(); }
typedef typename StorageType::GetType PeekType;
static PeekType peek(const StorageType& value) { return value.get(); }
static PeekType peek(EmptyValueType) { return PeekType(); }
};
}
#endif // Weak_h
|
