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Diffstat (limited to 'indra/llui/llhandle.h')
| -rw-r--r-- | indra/llui/llhandle.h | 181 |
1 files changed, 0 insertions, 181 deletions
diff --git a/indra/llui/llhandle.h b/indra/llui/llhandle.h deleted file mode 100644 index 37c657dd92..0000000000 --- a/indra/llui/llhandle.h +++ /dev/null @@ -1,181 +0,0 @@ -/** -* @file llhandle.h -* @brief "Handle" to an object (usually a floater) whose lifetime you don't -* control. -* -* $LicenseInfo:firstyear=2001&license=viewerlgpl$ -* Second Life Viewer Source Code -* Copyright (C) 2010, Linden Research, Inc. -* -* This library is free software; you can redistribute it and/or -* modify it under the terms of the GNU Lesser General Public -* License as published by the Free Software Foundation; -* version 2.1 of the License only. -* -* 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 -* Lesser General Public License for more details. -* -* You should have received a copy of the GNU Lesser General Public -* License along with this library; if not, write to the Free Software -* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA -* -* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA -* $/LicenseInfo$ -*/ -#ifndef LLHANDLE_H -#define LLHANDLE_H - -#include "llpointer.h" -#include <boost/type_traits/is_convertible.hpp> -#include <boost/utility/enable_if.hpp> - -class LLTombStone : public LLRefCount -{ -public: - LLTombStone(void* target = NULL) : mTarget(target) {} - - void setTarget(void* target) { mTarget = target; } - void* getTarget() const { return mTarget; } -private: - mutable void* mTarget; -}; - -// LLHandles are used to refer to objects whose lifetime you do not control or influence. -// Calling get() on a handle will return a pointer to the referenced object or NULL, -// if the object no longer exists. Note that during the lifetime of the returned pointer, -// you are assuming that the object will not be deleted by any action you perform, -// or any other thread, as normal when using pointers, so avoid using that pointer outside of -// the local code block. -// -// https://wiki.lindenlab.com/mediawiki/index.php?title=LLHandle&oldid=79669 - -template <typename T> -class LLHandle -{ - template <typename U> friend class LLHandle; - template <typename U> friend class LLHandleProvider; -public: - LLHandle() : mTombStone(getDefaultTombStone()) {} - - template<typename U> - LLHandle(const LLHandle<U>& other, typename boost::enable_if< typename boost::is_convertible<U*, T*> >::type* dummy = 0) - : mTombStone(other.mTombStone) - {} - - bool isDead() const - { - return mTombStone->getTarget() == NULL; - } - - void markDead() - { - mTombStone = getDefaultTombStone(); - } - - T* get() const - { - return reinterpret_cast<T*>(mTombStone->getTarget()); - } - - friend bool operator== (const LLHandle<T>& lhs, const LLHandle<T>& rhs) - { - return lhs.mTombStone == rhs.mTombStone; - } - friend bool operator!= (const LLHandle<T>& lhs, const LLHandle<T>& rhs) - { - return !(lhs == rhs); - } - friend bool operator< (const LLHandle<T>& lhs, const LLHandle<T>& rhs) - { - return lhs.mTombStone < rhs.mTombStone; - } - friend bool operator> (const LLHandle<T>& lhs, const LLHandle<T>& rhs) - { - return lhs.mTombStone > rhs.mTombStone; - } - -protected: - LLPointer<LLTombStone> mTombStone; - -private: - typedef T* pointer_t; - static LLPointer<LLTombStone>& getDefaultTombStone() - { - static LLPointer<LLTombStone> sDefaultTombStone = new LLTombStone; - return sDefaultTombStone; - } -}; - -template <typename T> -class LLRootHandle : public LLHandle<T> -{ -public: - typedef LLRootHandle<T> self_t; - typedef LLHandle<T> base_t; - - LLRootHandle(T* object) { bind(object); } - LLRootHandle() {}; - ~LLRootHandle() { unbind(); } - - // this is redundant, since an LLRootHandle *is* an LLHandle - //LLHandle<T> getHandle() { return LLHandle<T>(*this); } - - void bind(T* object) - { - // unbind existing tombstone - if (LLHandle<T>::mTombStone.notNull()) - { - if (LLHandle<T>::mTombStone->getTarget() == (void*)object) return; - LLHandle<T>::mTombStone->setTarget(NULL); - } - // tombstone reference counted, so no paired delete - LLHandle<T>::mTombStone = new LLTombStone((void*)object); - } - - void unbind() - { - LLHandle<T>::mTombStone->setTarget(NULL); - } - - //don't allow copying of root handles, since there should only be one -private: - LLRootHandle(const LLRootHandle& other) {}; -}; - -// Use this as a mixin for simple classes that need handles and when you don't -// want handles at multiple points of the inheritance hierarchy -template <typename T> -class LLHandleProvider -{ -public: - LLHandle<T> getHandle() const - { - // perform lazy binding to avoid small tombstone allocations for handle - // providers whose handles are never referenced - mHandle.bind(static_cast<T*>(const_cast<LLHandleProvider<T>* >(this))); - return mHandle; - } - -protected: - typedef LLHandle<T> handle_type_t; - LLHandleProvider() - { - // provided here to enforce T deriving from LLHandleProvider<T> - } - - template <typename U> - LLHandle<U> getDerivedHandle(typename boost::enable_if< typename boost::is_convertible<U*, T*> >::type* dummy = 0) const - { - LLHandle<U> downcast_handle; - downcast_handle.mTombStone = getHandle().mTombStone; - return downcast_handle; - } - - -private: - mutable LLRootHandle<T> mHandle; -}; - -#endif |