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author | Steve Block <steveblock@google.com> | 2011-05-06 11:45:16 +0100 |
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committer | Steve Block <steveblock@google.com> | 2011-05-12 13:44:10 +0100 |
commit | cad810f21b803229eb11403f9209855525a25d57 (patch) | |
tree | 29a6fd0279be608e0fe9ffe9841f722f0f4e4269 /Source/JavaScriptCore/wtf/RefCounted.h | |
parent | 121b0cf4517156d0ac5111caf9830c51b69bae8f (diff) | |
download | external_webkit-cad810f21b803229eb11403f9209855525a25d57.zip external_webkit-cad810f21b803229eb11403f9209855525a25d57.tar.gz external_webkit-cad810f21b803229eb11403f9209855525a25d57.tar.bz2 |
Merge WebKit at r75315: Initial merge by git.
Change-Id: I570314b346ce101c935ed22a626b48c2af266b84
Diffstat (limited to 'Source/JavaScriptCore/wtf/RefCounted.h')
-rw-r--r-- | Source/JavaScriptCore/wtf/RefCounted.h | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/wtf/RefCounted.h b/Source/JavaScriptCore/wtf/RefCounted.h new file mode 100644 index 0000000..8d8b302 --- /dev/null +++ b/Source/JavaScriptCore/wtf/RefCounted.h @@ -0,0 +1,169 @@ +/* + * 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 "Assertions.h" +#include "Noncopyable.h" + +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 RefCountedBase { +public: + void ref() + { + ASSERT(!m_deletionHasBegun); + ASSERT(!m_adoptionIsRequired); + ++m_refCount; + } + + bool hasOneRef() const + { + ASSERT(!m_deletionHasBegun); + return m_refCount == 1; + } + + int refCount() const + { + return m_refCount; + } + + void relaxAdoptionRequirement() + { +#ifndef NDEBUG + ASSERT(!m_deletionHasBegun); + ASSERT(m_adoptionIsRequired); + m_adoptionIsRequired = false; +#endif + } + +protected: + RefCountedBase() + : m_refCount(1) +#ifndef NDEBUG + , m_deletionHasBegun(false) + , m_adoptionIsRequired(true) +#endif + { + } + + ~RefCountedBase() + { + ASSERT(m_deletionHasBegun); + ASSERT(!m_adoptionIsRequired); + } + + // Returns whether the pointer should be freed or not. + bool derefBase() + { + ASSERT(!m_deletionHasBegun); + ASSERT(!m_adoptionIsRequired); + + ASSERT(m_refCount > 0); + if (m_refCount == 1) { +#ifndef NDEBUG + m_deletionHasBegun = true; +#endif + return true; + } + + --m_refCount; + return false; + } + + // Helper for generating JIT code. Please do not use for non-JIT purposes. + int* addressOfCount() + { + return &m_refCount; + } + +#ifndef NDEBUG + bool deletionHasBegun() const + { + return m_deletionHasBegun; + } +#endif + +private: + template<typename T> friend class CrossThreadRefCounted; + +#ifndef NDEBUG + friend void adopted(RefCountedBase*); +#endif + + int m_refCount; +#ifndef NDEBUG + bool m_deletionHasBegun; + bool m_adoptionIsRequired; +#endif +}; + +#ifndef NDEBUG + +inline void adopted(RefCountedBase* object) +{ + if (!object) + return; + ASSERT(!object->m_deletionHasBegun); + object->m_adoptionIsRequired = false; +} + +#endif + +template<typename T> class RefCounted : public RefCountedBase, public Noncopyable { +public: + void deref() + { + if (derefBase()) + delete static_cast<T*>(this); + } + +protected: + ~RefCounted() + { + } +}; + +template<typename T> class RefCountedCustomAllocated : public RefCountedBase { + WTF_MAKE_NONCOPYABLE(RefCountedCustomAllocated); + +public: + void deref() + { + if (derefBase()) + delete static_cast<T*>(this); + } + +protected: + ~RefCountedCustomAllocated() + { + } +}; + +} // namespace WTF + +using WTF::RefCounted; +using WTF::RefCountedCustomAllocated; + +#endif // RefCounted_h |