| /**************************************************************************** |
| ** |
| ** Copyright (C) 2016 The Qt Company Ltd. |
| ** Contact: https://www.qt.io/licensing/ |
| ** |
| ** This file is part of the QtQml module of the Qt Toolkit. |
| ** |
| ** $QT_BEGIN_LICENSE:LGPL$ |
| ** Commercial License Usage |
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| ** GNU Lesser General Public License Usage |
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| ** GNU General Public License Usage |
| ** Alternatively, this file may be used under the terms of the GNU |
| ** General Public License version 2.0 or (at your option) the GNU General |
| ** Public license version 3 or any later version approved by the KDE Free |
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| ** $QT_END_LICENSE$ |
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| ****************************************************************************/ |
| #ifndef QV4HEAP_P_H |
| #define QV4HEAP_P_H |
| |
| // |
| // W A R N I N G |
| // ------------- |
| // |
| // This file is not part of the Qt API. It exists purely as an |
| // implementation detail. This header file may change from version to |
| // version without notice, or even be removed. |
| // |
| // We mean it. |
| // |
| |
| #include <QtCore/QString> |
| #include <private/qv4global_p.h> |
| #include <private/qv4mmdefs_p.h> |
| #include <private/qv4writebarrier_p.h> |
| #include <private/qv4vtable_p.h> |
| #include <QSharedPointer> |
| |
| // To check if Heap::Base::init is called (meaning, all subclasses did their init and called their |
| // parent's init all up the inheritance chain), define QML_CHECK_INIT_DESTROY_CALLS below. |
| #undef QML_CHECK_INIT_DESTROY_CALLS |
| |
| QT_BEGIN_NAMESPACE |
| |
| namespace QV4 { |
| |
| namespace Heap { |
| |
| template <typename T, size_t o> |
| struct Pointer { |
| static Q_CONSTEXPR size_t offset = o; |
| T operator->() const { return get(); } |
| operator T () const { return get(); } |
| |
| Base *base(); |
| |
| void set(EngineBase *e, T newVal) { |
| WriteBarrier::write(e, base(), &ptr, reinterpret_cast<Base *>(newVal)); |
| } |
| |
| T get() const { return reinterpret_cast<T>(ptr); } |
| |
| template <typename Type> |
| Type *cast() { return static_cast<Type *>(ptr); } |
| |
| Base *heapObject() const { return ptr; } |
| |
| private: |
| Base *ptr; |
| }; |
| typedef Pointer<char *, 0> V4PointerCheck; |
| Q_STATIC_ASSERT(std::is_trivial< V4PointerCheck >::value); |
| |
| struct Q_QML_EXPORT Base { |
| void *operator new(size_t) = delete; |
| |
| static void markObjects(Base *, MarkStack *); |
| |
| Pointer<InternalClass *, 0> internalClass; |
| |
| inline ReturnedValue asReturnedValue() const; |
| inline void mark(QV4::MarkStack *markStack); |
| |
| inline bool isMarked() const { |
| const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
| Chunk *c = h->chunk(); |
| Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase())); |
| return Chunk::testBit(c->blackBitmap, h - c->realBase()); |
| } |
| inline void setMarkBit() { |
| const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
| Chunk *c = h->chunk(); |
| Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase())); |
| return Chunk::setBit(c->blackBitmap, h - c->realBase()); |
| } |
| inline void setGrayBit() { |
| const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
| Chunk *c = h->chunk(); |
| Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase())); |
| return Chunk::setBit(c->grayBitmap, h - c->realBase()); |
| } |
| |
| inline bool inUse() const { |
| const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
| Chunk *c = h->chunk(); |
| Q_ASSERT(!Chunk::testBit(c->extendsBitmap, h - c->realBase())); |
| return Chunk::testBit(c->objectBitmap, h - c->realBase()); |
| } |
| |
| void *operator new(size_t, Managed *m) { return m; } |
| void *operator new(size_t, Base *m) { return m; } |
| void operator delete(void *, Base *) {} |
| |
| void init() { _setInitialized(); } |
| void destroy() { _setDestroyed(); } |
| #ifdef QML_CHECK_INIT_DESTROY_CALLS |
| enum { Uninitialized = 0, Initialized, Destroyed } _livenessStatus; |
| void _checkIsInitialized() { |
| if (_livenessStatus == Uninitialized) |
| fprintf(stderr, "ERROR: use of object '%s' before call to init() !!\n", |
| vtable()->className); |
| else if (_livenessStatus == Destroyed) |
| fprintf(stderr, "ERROR: use of object '%s' after call to destroy() !!\n", |
| vtable()->className); |
| Q_ASSERT(_livenessStatus == Initialized); |
| } |
| void _checkIsDestroyed() { |
| if (_livenessStatus == Initialized) |
| fprintf(stderr, "ERROR: object '%s' was never destroyed completely !!\n", |
| vtable()->className); |
| Q_ASSERT(_livenessStatus == Destroyed); |
| } |
| void _setInitialized() { Q_ASSERT(_livenessStatus == Uninitialized); _livenessStatus = Initialized; } |
| void _setDestroyed() { |
| if (_livenessStatus == Uninitialized) |
| fprintf(stderr, "ERROR: attempting to destroy an uninitialized object '%s' !!\n", |
| vtable()->className); |
| else if (_livenessStatus == Destroyed) |
| fprintf(stderr, "ERROR: attempting to destroy repeatedly object '%s' !!\n", |
| vtable()->className); |
| Q_ASSERT(_livenessStatus == Initialized); |
| _livenessStatus = Destroyed; |
| } |
| #else |
| Q_ALWAYS_INLINE void _checkIsInitialized() {} |
| Q_ALWAYS_INLINE void _checkIsDestroyed() {} |
| Q_ALWAYS_INLINE void _setInitialized() {} |
| Q_ALWAYS_INLINE void _setDestroyed() {} |
| #endif |
| }; |
| Q_STATIC_ASSERT(std::is_trivial< Base >::value); |
| // This class needs to consist only of pointer sized members to allow |
| // for a size/offset translation when cross-compiling between 32- and |
| // 64-bit. |
| Q_STATIC_ASSERT(std::is_standard_layout<Base>::value); |
| Q_STATIC_ASSERT(offsetof(Base, internalClass) == 0); |
| Q_STATIC_ASSERT(sizeof(Base) == QT_POINTER_SIZE); |
| |
| inline |
| void Base::mark(QV4::MarkStack *markStack) |
| { |
| Q_ASSERT(inUse()); |
| const HeapItem *h = reinterpret_cast<const HeapItem *>(this); |
| Chunk *c = h->chunk(); |
| size_t index = h - c->realBase(); |
| Q_ASSERT(!Chunk::testBit(c->extendsBitmap, index)); |
| quintptr *bitmap = c->blackBitmap + Chunk::bitmapIndex(index); |
| quintptr bit = Chunk::bitForIndex(index); |
| if (!(*bitmap & bit)) { |
| *bitmap |= bit; |
| markStack->push(this); |
| } |
| } |
| |
| template<typename T, size_t o> |
| Base *Pointer<T, o>::base() { |
| Base *base = reinterpret_cast<Base *>(this) - (offset/sizeof(Base *)); |
| Q_ASSERT(base->inUse()); |
| return base; |
| } |
| |
| } |
| |
| #ifdef QT_NO_QOBJECT |
| template <class T> |
| struct QQmlQPointer { |
| }; |
| #else |
| template <class T> |
| struct QQmlQPointer { |
| void init() |
| { |
| d = nullptr; |
| qObject = nullptr; |
| } |
| |
| void init(T *o) |
| { |
| Q_ASSERT(d == nullptr); |
| Q_ASSERT(qObject == nullptr); |
| if (o) { |
| d = QtSharedPointer::ExternalRefCountData::getAndRef(o); |
| qObject = o; |
| } |
| } |
| |
| void destroy() |
| { |
| if (d && !d->weakref.deref()) |
| delete d; |
| d = nullptr; |
| qObject = nullptr; |
| } |
| |
| T *data() const { |
| return d == nullptr || d->strongref.loadRelaxed() == 0 ? nullptr : qObject; |
| } |
| operator T*() const { return data(); } |
| inline T* operator->() const { return data(); } |
| QQmlQPointer &operator=(T *o) |
| { |
| if (d) |
| destroy(); |
| init(o); |
| return *this; |
| } |
| bool isNull() const Q_DECL_NOTHROW |
| { |
| return d == nullptr || qObject == nullptr || d->strongref.loadRelaxed() == 0; |
| } |
| |
| private: |
| QtSharedPointer::ExternalRefCountData *d; |
| QObject *qObject; |
| }; |
| Q_STATIC_ASSERT(std::is_trivial< QQmlQPointer<QObject> >::value); |
| #endif |
| |
| } |
| |
| QT_END_NAMESPACE |
| |
| #endif |