diff options
Diffstat (limited to 'indra/llcommon/llsingleton.h')
| -rw-r--r-- | indra/llcommon/llsingleton.h | 91 |
1 files changed, 67 insertions, 24 deletions
diff --git a/indra/llcommon/llsingleton.h b/indra/llcommon/llsingleton.h index dc1457e4f7..7aee1bb85f 100644 --- a/indra/llcommon/llsingleton.h +++ b/indra/llcommon/llsingleton.h @@ -1,31 +1,25 @@ /** * @file llsingleton.h * - * $LicenseInfo:firstyear=2002&license=viewergpl$ - * - * Copyright (c) 2002-2009, Linden Research, Inc. - * + * $LicenseInfo:firstyear=2002&license=viewerlgpl$ * 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 + * 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. * - * 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 + * 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. * - * 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. + * 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 * - * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO - * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY, - * COMPLETENESS OR PERFORMANCE. + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ #ifndef LLSINGLETON_H @@ -33,8 +27,41 @@ #include "llerror.h" // *TODO: eliminate this +#include <typeinfo> #include <boost/noncopyable.hpp> +/// @brief A global registry of all singletons to prevent duplicate allocations +/// across shared library boundaries +class LL_COMMON_API LLSingletonRegistry { + private: + typedef std::map<std::string, void *> TypeMap; + static TypeMap * sSingletonMap; + + static void checkInit() + { + if(sSingletonMap == NULL) + { + sSingletonMap = new TypeMap(); + } + } + + public: + template<typename T> static void * & get() + { + std::string name(typeid(T).name()); + + checkInit(); + + // the first entry of the pair returned by insert will be either the existing + // iterator matching our key, or the newly inserted NULL initialized entry + // see "Insert element" in http://www.sgi.com/tech/stl/UniqueAssociativeContainer.html + TypeMap::iterator result = + sSingletonMap->insert(std::make_pair(name, (void*)NULL)).first; + + return result->second; + } +}; + // LLSingleton implements the getInstance() method part of the Singleton // pattern. It can't make the derived class constructors protected, though, so // you have to do that yourself. @@ -107,8 +134,17 @@ public: static SingletonInstanceData& getData() { - static SingletonInstanceData data; - return data; + // this is static to cache the lookup results + static void * & registry = LLSingletonRegistry::get<DERIVED_TYPE>(); + + // *TODO - look into making this threadsafe + if(NULL == registry) + { + static SingletonInstanceData data; + registry = &data; + } + + return *static_cast<SingletonInstanceData *>(registry); } static DERIVED_TYPE* getInstance() @@ -143,7 +179,14 @@ public: { return *getInstance(); } - + + // Has this singleton been created uet? + // Use this to avoid accessing singletons before the can safely be constructed + static bool instanceExists() + { + return getData().mInitState == INITIALIZED; + } + // Has this singleton already been deleted? // Use this to avoid accessing singletons from a static object's destructor static bool destroyed() |