llpointer.h
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- /**
- * @file llpointer.h
- * @brief A reference-counted pointer for objects derived from LLRefCount
- *
- * $LicenseInfo:firstyear=2002&license=viewergpl$
- *
- * Copyright (c) 2002-2010, Linden Research, Inc.
- *
- * Second Life Viewer Source Code
- * The source code in this file ("Source Code") is provided by Linden Lab
- * to you under the terms of the GNU General Public License, version 2.0
- * ("GPL"), unless you have obtained a separate licensing agreement
- * ("Other License"), formally executed by you and Linden Lab. Terms of
- * the GPL can be found in doc/GPL-license.txt in this distribution, or
- * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
- *
- * There are special exceptions to the terms and conditions of the GPL as
- * it is applied to this Source Code. View the full text of the exception
- * in the file doc/FLOSS-exception.txt in this software distribution, or
- * online at
- * http://secondlifegrid.net/programs/open_source/licensing/flossexception
- *
- * By copying, modifying or distributing this software, you acknowledge
- * that you have read and understood your obligations described above,
- * and agree to abide by those obligations.
- *
- * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
- * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
- * COMPLETENESS OR PERFORMANCE.
- * $/LicenseInfo$
- */
- #ifndef LLPOINTER_H
- #define LLPOINTER_H
- #include "llerror.h" // *TODO: consider eliminating this
- //----------------------------------------------------------------------------
- // RefCount objects should generally only be accessed by way of LLPointer<>'s
- // NOTE: LLPointer<LLFoo> x = new LLFoo(); MAY NOT BE THREAD SAFE
- // if LLFoo::LLFoo() does anything like put itself in an update queue.
- // The queue may get accessed before it gets assigned to x.
- // The correct implementation is:
- // LLPointer<LLFoo> x = new LLFoo; // constructor does not do anything interesting
- // x->instantiate(); // does stuff like place x into an update queue
- // see llthread.h for LLThreadSafeRefCount
- //----------------------------------------------------------------------------
- // Note: relies on Type having ref() and unref() methods
- template <class Type> class LLPointer
- {
- public:
- LLPointer() :
- mPointer(NULL)
- {
- }
- LLPointer(Type* ptr) :
- mPointer(ptr)
- {
- ref();
- }
- LLPointer(const LLPointer<Type>& ptr) :
- mPointer(ptr.mPointer)
- {
- ref();
- }
- // support conversion up the type hierarchy. See Item 45 in Effective C++, 3rd Ed.
- template<typename Subclass>
- LLPointer(const LLPointer<Subclass>& ptr) :
- mPointer(ptr.get())
- {
- ref();
- }
- ~LLPointer()
- {
- unref();
- }
- Type* get() const { return mPointer; }
- const Type* operator->() const { return mPointer; }
- Type* operator->() { return mPointer; }
- const Type& operator*() const { return *mPointer; }
- Type& operator*() { return *mPointer; }
- operator BOOL() const { return (mPointer != NULL); }
- operator bool() const { return (mPointer != NULL); }
- bool operator!() const { return (mPointer == NULL); }
- bool isNull() const { return (mPointer == NULL); }
- bool notNull() const { return (mPointer != NULL); }
- operator Type*() const { return mPointer; }
- bool operator !=(Type* ptr) const { return (mPointer != ptr); }
- bool operator ==(Type* ptr) const { return (mPointer == ptr); }
- bool operator ==(const LLPointer<Type>& ptr) const { return (mPointer == ptr.mPointer); }
- bool operator < (const LLPointer<Type>& ptr) const { return (mPointer < ptr.mPointer); }
- bool operator > (const LLPointer<Type>& ptr) const { return (mPointer > ptr.mPointer); }
- LLPointer<Type>& operator =(Type* ptr)
- {
- if( mPointer != ptr )
- {
- unref();
- mPointer = ptr;
- ref();
- }
- return *this;
- }
- LLPointer<Type>& operator =(const LLPointer<Type>& ptr)
- {
- if( mPointer != ptr.mPointer )
- {
- unref();
- mPointer = ptr.mPointer;
- ref();
- }
- return *this;
- }
- // support assignment up the type hierarchy. See Item 45 in Effective C++, 3rd Ed.
- template<typename Subclass>
- LLPointer<Type>& operator =(const LLPointer<Subclass>& ptr)
- {
- if( mPointer != ptr.get() )
- {
- unref();
- mPointer = ptr.get();
- ref();
- }
- return *this;
- }
-
- // Just exchange the pointers, which will not change the reference counts.
- static void swap(LLPointer<Type>& a, LLPointer<Type>& b)
- {
- Type* temp = a.mPointer;
- a.mPointer = b.mPointer;
- b.mPointer = temp;
- }
- protected:
- void ref()
- {
- if (mPointer)
- {
- mPointer->ref();
- }
- }
- void unref()
- {
- if (mPointer)
- {
- Type *tempp = mPointer;
- mPointer = NULL;
- tempp->unref();
- if (mPointer != NULL)
- {
- llwarns << "Unreference did assignment to non-NULL because of destructor" << llendl;
- unref();
- }
- }
- }
- protected:
- Type* mPointer;
- };
- #endif