diff options
Diffstat (limited to 'src/qml/memory/qv4writebarrier_p.h')
| -rw-r--r-- | src/qml/memory/qv4writebarrier_p.h | 182 |
1 files changed, 102 insertions, 80 deletions
diff --git a/src/qml/memory/qv4writebarrier_p.h b/src/qml/memory/qv4writebarrier_p.h index d2dc4521f2..ddee183982 100644 --- a/src/qml/memory/qv4writebarrier_p.h +++ b/src/qml/memory/qv4writebarrier_p.h @@ -1,41 +1,5 @@ -/**************************************************************************** -** -** 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 -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** GNU Lesser General Public License Usage -** Alternatively, this file may be used under the terms of the GNU Lesser -** General Public License version 3 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL3 included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 3 requirements -** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. -** -** 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 -** Qt Foundation. The licenses are as published by the Free Software -** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 -** included in the packaging of this file. Please review the following -** information to ensure the GNU General Public License requirements will -** be met: https://www.gnu.org/licenses/gpl-2.0.html and -** https://www.gnu.org/licenses/gpl-3.0.html. -** -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2016 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only #ifndef QV4WRITEBARRIER_P_H #define QV4WRITEBARRIER_P_H @@ -51,57 +15,115 @@ // #include <private/qv4global_p.h> +#include <private/qv4enginebase_p.h> QT_BEGIN_NAMESPACE -#define WRITEBARRIER_none 1 - -#define WRITEBARRIER(x) (1/WRITEBARRIER_##x == 1) - namespace QV4 { struct EngineBase; - -namespace WriteBarrier { - -enum Type { - NoBarrier, - Barrier +typedef quint64 ReturnedValue; + +struct WriteBarrier { + + static constexpr bool isInsertionBarrier = true; + + Q_ALWAYS_INLINE static void write(EngineBase *engine, Heap::Base *base, ReturnedValue *slot, ReturnedValue value) + { + if (engine->isGCOngoing) + write_slowpath(engine, base, slot, value); + *slot = value; + } + Q_QML_EXPORT Q_NEVER_INLINE static void write_slowpath( + EngineBase *engine, Heap::Base *base, + ReturnedValue *slot, ReturnedValue value); + + Q_ALWAYS_INLINE static void write(EngineBase *engine, Heap::Base *base, Heap::Base **slot, Heap::Base *value) + { + if (engine->isGCOngoing) + write_slowpath(engine, base, slot, value); + *slot = value; + } + Q_QML_EXPORT Q_NEVER_INLINE static void write_slowpath( + EngineBase *engine, Heap::Base *base, + Heap::Base **slot, Heap::Base *value); + + // MemoryManager isn't a complete type here, so make Engine a template argument + // so that we can still call engine->memoryManager->markStack() + template<typename F, typename Engine = EngineBase> + static void markCustom(Engine *engine, F &&markFunction) { + if (engine->isGCOngoing) + (std::forward<F>(markFunction))(engine->memoryManager->markStack()); + } + + // HeapObjectWrapper(Base) are helper classes to ensure that + // we always use a WriteBarrier when setting heap-objects + // they are also trivial; if triviality is not required, use Pointer instead + struct HeapObjectWrapperBase + { + // enum class avoids accidental construction via brace-init + enum class PointerWrapper : quintptr {}; + PointerWrapper wrapped; + + void clear() { wrapped = PointerWrapper(quintptr(0)); } + }; + + template<typename HeapType> + struct HeapObjectWrapperCommon : HeapObjectWrapperBase + { + HeapType *get() const { return reinterpret_cast<HeapType *>(wrapped); } + operator HeapType *() const { return get(); } + HeapType * operator->() const { return get(); } + + template <typename ConvertibleToHeapType> + void set(QV4::EngineBase *engine, ConvertibleToHeapType *heapObject) + { + WriteBarrier::markCustom(engine, [heapObject](QV4::MarkStack *ms){ + if (heapObject) + heapObject->mark(ms); + }); + wrapped = static_cast<HeapObjectWrapperBase::PointerWrapper>(quintptr(heapObject)); + } + }; + + // all types are trivial; we however want to block copies bypassing the write barrier + // therefore, all members use a PhantomTag to reduce the likelihood + template<typename HeapType, int PhantomTag> + struct HeapObjectWrapper : HeapObjectWrapperCommon<HeapType> {}; + + /* similar Heap::Pointer, but without the Base conversion (and its inUse assert) + and for storing references in engine classes stored on the native heap + Stores a "non-owning" reference to a heap-item (in the C++ sense), but should + generally mark the heap-item; therefore set goes through a write-barrier + */ + template<typename T> + struct Pointer + { + Pointer() = default; + ~Pointer() = default; + Q_DISABLE_COPY_MOVE(Pointer) + T* operator->() const { return get(); } + operator T* () const { return get(); } + + void set(EngineBase *e, T *newVal) { + WriteBarrier::markCustom(e, [newVal](QV4::MarkStack *ms) { + if (newVal) + newVal->mark(ms); + }); + ptr = newVal; + } + + T* get() const { return ptr; } + + + + private: + T *ptr = nullptr; + }; }; -enum NewValueType { - Primitive, - Object, - Unknown -}; - -// ### this needs to be filled with a real memory fence once marking is concurrent + // ### this needs to be filled with a real memory fence once marking is concurrent Q_ALWAYS_INLINE void fence() {} -#if WRITEBARRIER(none) - -template <NewValueType type> -static constexpr inline bool isRequired() { - return false; -} - -inline void write(EngineBase *engine, Heap::Base *base, ReturnedValue *slot, ReturnedValue value) -{ - Q_UNUSED(engine); - Q_UNUSED(base); - *slot = value; -} - -inline void write(EngineBase *engine, Heap::Base *base, Heap::Base **slot, Heap::Base *value) -{ - Q_UNUSED(engine); - Q_UNUSED(base); - *slot = value; -} - -#endif - -} - } QT_END_NAMESPACE |