| /* |
| * Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved. |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this library; see the file COPYING.LIB. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| * |
| */ |
| |
| #ifndef RefCounted_h |
| #define RefCounted_h |
| |
| #include "platform/wtf/Allocator.h" |
| #include "platform/wtf/Assertions.h" |
| #include "platform/wtf/Noncopyable.h" |
| #include "platform/wtf/WTFExport.h" |
| |
| #if ENABLE(INSTANCE_COUNTER) |
| #include "platform/wtf/InstanceCounter.h" |
| #endif |
| |
| #if DCHECK_IS_ON() |
| #define CHECK_REF_COUNTED_LIFECYCLE 1 |
| #include "platform/wtf/ThreadRestrictionVerifier.h" |
| #else |
| #define CHECK_REF_COUNTED_LIFECYCLE 0 |
| #endif |
| |
| namespace WTF { |
| |
| // This base class holds the non-template methods and attributes. |
| // The RefCounted class inherits from it reducing the template bloat |
| // generated by the compiler (technique called template hoisting). |
| class WTF_EXPORT RefCountedBase { |
| public: |
| void ref() const { |
| #if CHECK_REF_COUNTED_LIFECYCLE |
| SECURITY_DCHECK(m_verifier.onRef(m_refCount)); |
| DCHECK(!m_adoptionIsRequired); |
| #endif |
| SECURITY_DCHECK(!m_deletionHasBegun); |
| ++m_refCount; |
| } |
| |
| bool hasOneRef() const { |
| SECURITY_DCHECK(!m_deletionHasBegun); |
| #if CHECK_REF_COUNTED_LIFECYCLE |
| SECURITY_DCHECK(m_verifier.isSafeToUse()); |
| #endif |
| return m_refCount == 1; |
| } |
| |
| int refCount() const { |
| #if CHECK_REF_COUNTED_LIFECYCLE |
| SECURITY_DCHECK(m_verifier.isSafeToUse()); |
| #endif |
| return m_refCount; |
| } |
| |
| protected: |
| RefCountedBase() |
| : m_refCount(1) |
| #if ENABLE(SECURITY_ASSERT) |
| , |
| m_deletionHasBegun(false) |
| #endif |
| #if CHECK_REF_COUNTED_LIFECYCLE |
| , |
| m_adoptionIsRequired(true) |
| #endif |
| { |
| } |
| |
| ~RefCountedBase() { |
| SECURITY_DCHECK(m_deletionHasBegun); |
| #if CHECK_REF_COUNTED_LIFECYCLE |
| DCHECK(!m_adoptionIsRequired); |
| #endif |
| } |
| |
| // Returns whether the pointer should be freed or not. |
| bool derefBase() const { |
| SECURITY_DCHECK(!m_deletionHasBegun); |
| #if CHECK_REF_COUNTED_LIFECYCLE |
| SECURITY_DCHECK(m_verifier.onDeref(m_refCount)); |
| DCHECK(!m_adoptionIsRequired); |
| #endif |
| |
| DCHECK_GT(m_refCount, 0); |
| --m_refCount; |
| if (!m_refCount) { |
| #if ENABLE(SECURITY_ASSERT) |
| m_deletionHasBegun = true; |
| #endif |
| return true; |
| } |
| |
| return false; |
| } |
| |
| #if CHECK_REF_COUNTED_LIFECYCLE |
| bool deletionHasBegun() const { return m_deletionHasBegun; } |
| #endif |
| |
| private: |
| #if CHECK_REF_COUNTED_LIFECYCLE || ENABLE(SECURITY_ASSERT) |
| friend void adopted(RefCountedBase*); |
| #endif |
| |
| mutable int m_refCount; |
| #if ENABLE(SECURITY_ASSERT) |
| mutable bool m_deletionHasBegun; |
| #endif |
| #if CHECK_REF_COUNTED_LIFECYCLE |
| mutable bool m_adoptionIsRequired; |
| mutable ThreadRestrictionVerifier m_verifier; |
| #endif |
| }; |
| |
| #if CHECK_REF_COUNTED_LIFECYCLE || ENABLE(SECURITY_ASSERT) |
| inline void adopted(RefCountedBase* object) { |
| if (!object) |
| return; |
| SECURITY_DCHECK(!object->m_deletionHasBegun); |
| #if CHECK_REF_COUNTED_LIFECYCLE |
| object->m_adoptionIsRequired = false; |
| #endif |
| } |
| #endif |
| |
| template <typename T> |
| class RefCounted : public RefCountedBase { |
| WTF_MAKE_NONCOPYABLE(RefCounted); |
| |
| // Put |T| in here instead of |RefCounted| so the heap profiler reports |T| |
| // instead of |RefCounted<T>|. This does not affect overloading of operator |
| // new. |
| USING_FAST_MALLOC(T); |
| |
| public: |
| void deref() const { |
| if (derefBase()) |
| delete static_cast<const T*>(this); |
| } |
| |
| protected: |
| #if ENABLE(INSTANCE_COUNTER) |
| RefCounted() { incrementInstanceCount<T>(static_cast<T*>(this)); } |
| |
| ~RefCounted() { decrementInstanceCount<T>(static_cast<T*>(this)); } |
| #else |
| RefCounted() {} |
| #endif |
| }; |
| |
| // Allows subclasses to use the default copy constructor. |
| template <typename T> |
| class RefCountedCopyable : public RefCounted<T> { |
| protected: |
| RefCountedCopyable() = default; |
| RefCountedCopyable(const RefCountedCopyable&) : RefCounted<T>() {} |
| }; |
| |
| } // namespace WTF |
| |
| using WTF::RefCounted; |
| using WTF::RefCountedCopyable; |
| |
| #endif // RefCounted_h |