--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/wtf/PassRefPtr.h Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,309 @@
+/*
+ * 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"
+
+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 (UNLIKELY(ptr != 0))
+ ptr->ref();
+ }
+
+ template<typename T> REF_DEREF_INLINE void derefIfNotNull(T* ptr)
+ {
+ if (UNLIKELY(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.releaseRef()) { }
+ template<typename U> PassRefPtr(const PassRefPtr<U>& o) : m_ptr(o.releaseRef()) { }
+
+ 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&);
+ 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 releaseRef()
+ // 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.releaseRef())
+ {
+ ASSERT(m_ptr);
+ }
+
+ template<typename U> NonNullPassRefPtr(const NonNullPassRefPtr<U>& o)
+ : m_ptr(o.releaseRef())
+ {
+ ASSERT(m_ptr);
+ }
+
+ template<typename U> NonNullPassRefPtr(const PassRefPtr<U>& o)
+ : m_ptr(o.releaseRef())
+ {
+ 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.releaseRef();
+ 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.releaseRef();
+ 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.releaseRef()));
+ }
+
+ template<typename T, typename U> inline PassRefPtr<T> const_pointer_cast(const PassRefPtr<U>& p)
+ {
+ return adoptRef(const_cast<T*>(p.releaseRef()));
+ }
+
+ 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