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39 | #ifndef QV4HEAP_P_H |
40 | #define QV4HEAP_P_H |
41 | |
42 | // |
43 | // W A R N I N G |
44 | // ------------- |
45 | // |
46 | // This file is not part of the Qt API. It exists purely as an |
47 | // implementation detail. This header file may change from version to |
48 | // version without notice, or even be removed. |
49 | // |
50 | // We mean it. |
51 | // |
52 | |
53 | #include <QtCore/QString> |
54 | #include <private/qv4global_p.h> |
55 | #include <private/qv4mmdefs_p.h> |
56 | #include <private/qv4writebarrier_p.h> |
57 | #include <private/qv4vtable_p.h> |
58 | #include <QSharedPointer> |
59 | |
60 | // To check if Heap::Base::init is called (meaning, all subclasses did their init and called their |
61 | // parent's init all up the inheritance chain), define QML_CHECK_INIT_DESTROY_CALLS below. |
62 | #undef QML_CHECK_INIT_DESTROY_CALLS |
63 | |
64 | QT_BEGIN_NAMESPACE |
65 | |
66 | namespace QV4 { |
67 | |
68 | namespace Heap { |
69 | |
70 | template <typename T, size_t o> |
71 | struct Pointer { |
72 | static Q_CONSTEXPR size_t offset = o; |
73 | T operator->() const { return get(); } |
74 | operator T () const { return get(); } |
75 | |
76 | Base *base(); |
77 | |
78 | void set(EngineBase *e, T newVal) { |
79 | WriteBarrier::write(e, base(), &ptr, reinterpret_cast<Base *>(newVal)); |
80 | } |
81 | |
82 | T get() const { return reinterpret_cast<T>(ptr); } |
83 | |
84 | template <typename Type> |
85 | Type *cast() { return static_cast<Type *>(ptr); } |
86 | |
87 | Base *heapObject() const { return ptr; } |
88 | |
89 | private: |
90 | Base *ptr; |
91 | }; |
92 | typedef Pointer<char *, 0> V4PointerCheck; |
93 | Q_STATIC_ASSERT(std::is_trivial< V4PointerCheck >::value); |
94 | |
95 | struct Q_QML_EXPORT Base { |
96 | void *operator new(size_t) = delete; |
97 | |
98 | static void markObjects(Base *, MarkStack *); |
99 | |
100 | Pointer<InternalClass *, 0> internalClass; |
101 | |
102 | inline ReturnedValue asReturnedValue() const; |
103 | inline void mark(QV4::MarkStack *markStack); |
104 | |
105 | inline bool isMarked() const { |
106 | const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
107 | Chunk *c = h->chunk(); |
108 | Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase())); |
109 | return Chunk::testBit(bitmap: c->blackBitmap, index: h - c->realBase()); |
110 | } |
111 | inline void setMarkBit() { |
112 | const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
113 | Chunk *c = h->chunk(); |
114 | Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase())); |
115 | return Chunk::setBit(bitmap: c->blackBitmap, index: h - c->realBase()); |
116 | } |
117 | inline void setGrayBit() { |
118 | const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
119 | Chunk *c = h->chunk(); |
120 | Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase())); |
121 | return Chunk::setBit(bitmap: c->grayBitmap, index: h - c->realBase()); |
122 | } |
123 | |
124 | inline bool inUse() const { |
125 | const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
126 | Chunk *c = h->chunk(); |
127 | Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase())); |
128 | return Chunk::testBit(bitmap: c->objectBitmap, index: h - c->realBase()); |
129 | } |
130 | |
131 | void *operator new(size_t, Managed *m) { return m; } |
132 | void *operator new(size_t, Base *m) { return m; } |
133 | void operator delete(void *, Base *) {} |
134 | |
135 | void init() { _setInitialized(); } |
136 | void destroy() { _setDestroyed(); } |
137 | #ifdef QML_CHECK_INIT_DESTROY_CALLS |
138 | enum { Uninitialized = 0, Initialized, Destroyed } _livenessStatus; |
139 | void _checkIsInitialized() { |
140 | if (_livenessStatus == Uninitialized) |
141 | fprintf(stderr, "ERROR: use of object '%s' before call to init() !!\n" , |
142 | vtable()->className); |
143 | else if (_livenessStatus == Destroyed) |
144 | fprintf(stderr, "ERROR: use of object '%s' after call to destroy() !!\n" , |
145 | vtable()->className); |
146 | Q_ASSERT(_livenessStatus == Initialized); |
147 | } |
148 | void _checkIsDestroyed() { |
149 | if (_livenessStatus == Initialized) |
150 | fprintf(stderr, "ERROR: object '%s' was never destroyed completely !!\n" , |
151 | vtable()->className); |
152 | Q_ASSERT(_livenessStatus == Destroyed); |
153 | } |
154 | void _setInitialized() { Q_ASSERT(_livenessStatus == Uninitialized); _livenessStatus = Initialized; } |
155 | void _setDestroyed() { |
156 | if (_livenessStatus == Uninitialized) |
157 | fprintf(stderr, "ERROR: attempting to destroy an uninitialized object '%s' !!\n" , |
158 | vtable()->className); |
159 | else if (_livenessStatus == Destroyed) |
160 | fprintf(stderr, "ERROR: attempting to destroy repeatedly object '%s' !!\n" , |
161 | vtable()->className); |
162 | Q_ASSERT(_livenessStatus == Initialized); |
163 | _livenessStatus = Destroyed; |
164 | } |
165 | #else |
166 | Q_ALWAYS_INLINE void _checkIsInitialized() {} |
167 | Q_ALWAYS_INLINE void _checkIsDestroyed() {} |
168 | Q_ALWAYS_INLINE void _setInitialized() {} |
169 | Q_ALWAYS_INLINE void _setDestroyed() {} |
170 | #endif |
171 | }; |
172 | Q_STATIC_ASSERT(std::is_trivial< Base >::value); |
173 | // This class needs to consist only of pointer sized members to allow |
174 | // for a size/offset translation when cross-compiling between 32- and |
175 | // 64-bit. |
176 | Q_STATIC_ASSERT(std::is_standard_layout<Base>::value); |
177 | Q_STATIC_ASSERT(offsetof(Base, internalClass) == 0); |
178 | Q_STATIC_ASSERT(sizeof(Base) == QT_POINTER_SIZE); |
179 | |
180 | inline |
181 | void Base::mark(QV4::MarkStack *markStack) |
182 | { |
183 | Q_ASSERT(inUse()); |
184 | const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
185 | Chunk *c = h->chunk(); |
186 | size_t index = h - c->realBase(); |
187 | Q_ASSERT(!Chunk::testBit(c->extendsBitmap, index)); |
188 | quintptr *bitmap = c->blackBitmap + Chunk::bitmapIndex(index); |
189 | quintptr bit = Chunk::bitForIndex(index); |
190 | if (!(*bitmap & bit)) { |
191 | *bitmap |= bit; |
192 | markStack->push(m: this); |
193 | } |
194 | } |
195 | |
196 | template<typename T, size_t o> |
197 | Base *Pointer<T, o>::base() { |
198 | Base *base = reinterpret_cast<Base *>(this) - (offset/sizeof(Base *)); |
199 | Q_ASSERT(base->inUse()); |
200 | return base; |
201 | } |
202 | |
203 | } |
204 | |
205 | #ifdef QT_NO_QOBJECT |
206 | template <class T> |
207 | struct QQmlQPointer { |
208 | }; |
209 | #else |
210 | template <class T> |
211 | struct QQmlQPointer { |
212 | void init() |
213 | { |
214 | d = nullptr; |
215 | qObject = nullptr; |
216 | } |
217 | |
218 | void init(T *o) |
219 | { |
220 | Q_ASSERT(d == nullptr); |
221 | Q_ASSERT(qObject == nullptr); |
222 | if (o) { |
223 | d = QtSharedPointer::ExternalRefCountData::getAndRef(o); |
224 | qObject = o; |
225 | } |
226 | } |
227 | |
228 | void destroy() |
229 | { |
230 | if (d && !d->weakref.deref()) |
231 | delete d; |
232 | d = nullptr; |
233 | qObject = nullptr; |
234 | } |
235 | |
236 | T *data() const { |
237 | return d == nullptr || d->strongref.loadRelaxed() == 0 ? nullptr : qObject; |
238 | } |
239 | operator T*() const { return data(); } |
240 | inline T* operator->() const { return data(); } |
241 | QQmlQPointer &operator=(T *o) |
242 | { |
243 | if (d) |
244 | destroy(); |
245 | init(o); |
246 | return *this; |
247 | } |
248 | bool isNull() const Q_DECL_NOTHROW |
249 | { |
250 | return d == nullptr || qObject == nullptr || d->strongref.loadRelaxed() == 0; |
251 | } |
252 | |
253 | private: |
254 | QtSharedPointer::ExternalRefCountData *d; |
255 | QObject *qObject; |
256 | }; |
257 | Q_STATIC_ASSERT(std::is_trivial< QQmlQPointer<QObject> >::value); |
258 | #endif |
259 | |
260 | } |
261 | |
262 | QT_END_NAMESPACE |
263 | |
264 | #endif |
265 | |