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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/PassRefPtr.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/PassRefPtr.h')
-rw-r--r-- | Source/JavaScriptCore/wtf/PassRefPtr.h | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/wtf/PassRefPtr.h b/Source/JavaScriptCore/wtf/PassRefPtr.h new file mode 100644 index 0000000..7b4af6b --- /dev/null +++ b/Source/JavaScriptCore/wtf/PassRefPtr.h @@ -0,0 +1,313 @@ +/* + * Copyright (C) 2005, 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 WTF_PassRefPtr_h +#define WTF_PassRefPtr_h + +#include "AlwaysInline.h" +#include "NullPtr.h" + +namespace WTF { + + template<typename T> class RefPtr; + template<typename T> class PassRefPtr; + template<typename T> PassRefPtr<T> adoptRef(T*); + + inline void adopted(const void*) { } + +#if !COMPILER(WINSCW) +#if !PLATFORM(QT) + #define REF_DEREF_INLINE ALWAYS_INLINE +#else + // Using ALWAYS_INLINE broke the Qt build. This may be a GCC bug. + // See https://bugs.webkit.org/show_bug.cgi?id=37253 for details. + #define REF_DEREF_INLINE inline +#endif +#else + // No inlining for WINSCW compiler to prevent the compiler agressively resolving + // T::ref() and T::deref(), which will fail compiling when PassRefPtr<T> is used as + // a class member or function arguments before T is defined. + #define REF_DEREF_INLINE +#endif + + template<typename T> REF_DEREF_INLINE void refIfNotNull(T* ptr) + { + if (LIKELY(ptr != 0)) + ptr->ref(); + } + + template<typename T> REF_DEREF_INLINE void derefIfNotNull(T* ptr) + { + if (LIKELY(ptr != 0)) + ptr->deref(); + } + + #undef REF_DEREF_INLINE + + template<typename T> class PassRefPtr { + public: + PassRefPtr() : m_ptr(0) { } + PassRefPtr(T* ptr) : m_ptr(ptr) { refIfNotNull(ptr); } + // It somewhat breaks the type system to allow transfer of ownership out of + // a const PassRefPtr. However, it makes it much easier to work with PassRefPtr + // temporaries, and we don't have a need to use real const PassRefPtrs anyway. + PassRefPtr(const PassRefPtr& o) : m_ptr(o.leakRef()) { } + template<typename U> PassRefPtr(const PassRefPtr<U>& o) : m_ptr(o.leakRef()) { } + + ALWAYS_INLINE ~PassRefPtr() { derefIfNotNull(m_ptr); } + + template<typename U> PassRefPtr(const RefPtr<U>&); + + T* get() const { return m_ptr; } + + void clear(); + T* leakRef() const WARN_UNUSED_RETURN; + + T& operator*() const { return *m_ptr; } + T* operator->() const { return m_ptr; } + + bool operator!() const { return !m_ptr; } + + // This conversion operator allows implicit conversion to bool but not to other integer types. + typedef T* (PassRefPtr::*UnspecifiedBoolType); + operator UnspecifiedBoolType() const { return m_ptr ? &PassRefPtr::m_ptr : 0; } + + PassRefPtr& operator=(T*); + PassRefPtr& operator=(const PassRefPtr&); +#if !HAVE(NULLPTR) + PassRefPtr& operator=(std::nullptr_t) { clear(); return *this; } +#endif + template<typename U> PassRefPtr& operator=(const PassRefPtr<U>&); + template<typename U> PassRefPtr& operator=(const RefPtr<U>&); + + friend PassRefPtr adoptRef<T>(T*); + + // FIXME: Remove releaseRef once we change all callers to call leakRef instead. + T* releaseRef() const WARN_UNUSED_RETURN { return leakRef(); } + + private: + // adopting constructor + PassRefPtr(T* ptr, bool) : m_ptr(ptr) { } + + mutable T* m_ptr; + }; + + // NonNullPassRefPtr: Optimized for passing non-null pointers. A NonNullPassRefPtr + // begins life non-null, and can only become null through a call to leakRef() + // or clear(). + + // FIXME: NonNullPassRefPtr could just inherit from PassRefPtr. However, + // if we use inheritance, GCC's optimizer fails to realize that destruction + // of a released NonNullPassRefPtr is a no-op. So, for now, just copy the + // most important code from PassRefPtr. + template<typename T> class NonNullPassRefPtr { + public: + NonNullPassRefPtr(T* ptr) + : m_ptr(ptr) + { + ASSERT(m_ptr); + m_ptr->ref(); + } + + template<typename U> NonNullPassRefPtr(const RefPtr<U>& o) + : m_ptr(o.get()) + { + ASSERT(m_ptr); + m_ptr->ref(); + } + + NonNullPassRefPtr(const NonNullPassRefPtr& o) + : m_ptr(o.leakRef()) + { + ASSERT(m_ptr); + } + + template<typename U> NonNullPassRefPtr(const NonNullPassRefPtr<U>& o) + : m_ptr(o.leakRef()) + { + ASSERT(m_ptr); + } + + template<typename U> NonNullPassRefPtr(const PassRefPtr<U>& o) + : m_ptr(o.leakRef()) + { + ASSERT(m_ptr); + } + + ALWAYS_INLINE ~NonNullPassRefPtr() { derefIfNotNull(m_ptr); } + + T* get() const { return m_ptr; } + + void clear(); + T* leakRef() const WARN_UNUSED_RETURN { T* tmp = m_ptr; m_ptr = 0; return tmp; } + + T& operator*() const { return *m_ptr; } + T* operator->() const { return m_ptr; } + + // FIXME: Remove releaseRef once we change all callers to call leakRef instead. + T* releaseRef() const WARN_UNUSED_RETURN { return leakRef(); } + + private: + mutable T* m_ptr; + }; + + template<typename T> template<typename U> inline PassRefPtr<T>::PassRefPtr(const RefPtr<U>& o) + : m_ptr(o.get()) + { + T* ptr = m_ptr; + refIfNotNull(ptr); + } + + template<typename T> inline void PassRefPtr<T>::clear() + { + T* ptr = m_ptr; + m_ptr = 0; + derefIfNotNull(ptr); + } + + template<typename T> inline T* PassRefPtr<T>::leakRef() const + { + T* ptr = m_ptr; + m_ptr = 0; + return ptr; + } + + template<typename T> template<typename U> inline PassRefPtr<T>& PassRefPtr<T>::operator=(const RefPtr<U>& o) + { + T* optr = o.get(); + refIfNotNull(optr); + T* ptr = m_ptr; + m_ptr = optr; + derefIfNotNull(ptr); + return *this; + } + + template<typename T> inline PassRefPtr<T>& PassRefPtr<T>::operator=(T* optr) + { + refIfNotNull(optr); + T* ptr = m_ptr; + m_ptr = optr; + derefIfNotNull(ptr); + return *this; + } + + template<typename T> inline PassRefPtr<T>& PassRefPtr<T>::operator=(const PassRefPtr<T>& ref) + { + T* ptr = m_ptr; + m_ptr = ref.leakRef(); + derefIfNotNull(ptr); + return *this; + } + + template<typename T> template<typename U> inline PassRefPtr<T>& PassRefPtr<T>::operator=(const PassRefPtr<U>& ref) + { + T* ptr = m_ptr; + m_ptr = ref.leakRef(); + derefIfNotNull(ptr); + return *this; + } + + template<typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, const PassRefPtr<U>& b) + { + return a.get() == b.get(); + } + + template<typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, const RefPtr<U>& b) + { + return a.get() == b.get(); + } + + template<typename T, typename U> inline bool operator==(const RefPtr<T>& a, const PassRefPtr<U>& b) + { + return a.get() == b.get(); + } + + template<typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, U* b) + { + return a.get() == b; + } + + template<typename T, typename U> inline bool operator==(T* a, const PassRefPtr<U>& b) + { + return a == b.get(); + } + + template<typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, const PassRefPtr<U>& b) + { + return a.get() != b.get(); + } + + template<typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, const RefPtr<U>& b) + { + return a.get() != b.get(); + } + + template<typename T, typename U> inline bool operator!=(const RefPtr<T>& a, const PassRefPtr<U>& b) + { + return a.get() != b.get(); + } + + template<typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, U* b) + { + return a.get() != b; + } + + template<typename T, typename U> inline bool operator!=(T* a, const PassRefPtr<U>& b) + { + return a != b.get(); + } + + template<typename T> inline PassRefPtr<T> adoptRef(T* p) + { + adopted(p); + return PassRefPtr<T>(p, true); + } + + template<typename T, typename U> inline PassRefPtr<T> static_pointer_cast(const PassRefPtr<U>& p) + { + return adoptRef(static_cast<T*>(p.leakRef())); + } + + template<typename T, typename U> inline PassRefPtr<T> const_pointer_cast(const PassRefPtr<U>& p) + { + return adoptRef(const_cast<T*>(p.leakRef())); + } + + template<typename T> inline T* getPtr(const PassRefPtr<T>& p) + { + return p.get(); + } + + template<typename T> inline void NonNullPassRefPtr<T>::clear() + { + T* ptr = m_ptr; + m_ptr = 0; + derefIfNotNull(ptr); + } + +} // namespace WTF + +using WTF::PassRefPtr; +using WTF::NonNullPassRefPtr; +using WTF::adoptRef; +using WTF::static_pointer_cast; +using WTF::const_pointer_cast; + +#endif // WTF_PassRefPtr_h |