llmemory.h cleanup. pulled llpointer, refcounter, smartpointer, singleton and safe handle out into their own headers. llmemory.h drags all those headers in for legacy support until everything else is cleaned up. getCurrentRSS() moved into LLMemory. getWorkingSetSize() added to LLMemory.

indra/llcommon/llsingleton.h

@@ -0,0 +1,201 @@
+/** 
+ * @file llsingleton.h
+ *
+ * $LicenseInfo:firstyear=2002&license=viewerlgpl$
+ * 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 LLSINGLETON_H
+#define LLSINGLETON_H
+
+#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.
+//
+// There are two ways to use LLSingleton. The first way is to inherit from it
+// while using the typename that you'd like to be static as the template
+// parameter, like so:
+//
+//   class Foo: public LLSingleton<Foo>{};
+//
+//   Foo& instance = Foo::instance();
+//
+// The second way is to use the singleton class directly, without inheritance:
+//
+//   typedef LLSingleton<Foo> FooSingleton;
+//
+//   Foo& instance = FooSingleton::instance();
+//
+// In this case, the class being managed as a singleton needs to provide an
+// initSingleton() method since the LLSingleton virtual method won't be
+// available
+//
+// As currently written, it is not thread-safe.
+
+template <typename DERIVED_TYPE>
+class LLSingleton : private boost::noncopyable
+{
+	
+private:
+	typedef enum e_init_state
+	{
+		UNINITIALIZED,
+		CONSTRUCTING,
+		INITIALIZING,
+		INITIALIZED,
+		DELETED
+	} EInitState;
+	
+	static void deleteSingleton()
+	{
+		delete getData().mSingletonInstance;
+		getData().mSingletonInstance = NULL;
+	}
+	
+	// stores pointer to singleton instance
+	// and tracks initialization state of singleton
+	struct SingletonInstanceData
+	{
+		EInitState		mInitState;
+		DERIVED_TYPE*	mSingletonInstance;
+		
+		SingletonInstanceData()
+		:	mSingletonInstance(NULL),
+			mInitState(UNINITIALIZED)
+		{}
+
+		~SingletonInstanceData()
+		{
+			deleteSingleton();
+		}
+	};
+	
+public:
+	virtual ~LLSingleton()
+	{
+		SingletonInstanceData& data = getData();
+		data.mSingletonInstance = NULL;
+		data.mInitState = DELETED;
+	}
+
+	static SingletonInstanceData& getData()
+	{
+		// 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()
+	{
+		SingletonInstanceData& data = getData();
+
+		if (data.mInitState == CONSTRUCTING)
+		{
+			llerrs << "Tried to access singleton " << typeid(DERIVED_TYPE).name() << " from singleton constructor!" << llendl;
+		}
+
+		if (data.mInitState == DELETED)
+		{
+			llwarns << "Trying to access deleted singleton " << typeid(DERIVED_TYPE).name() << " creating new instance" << llendl;
+		}
+		
+		if (!data.mSingletonInstance) 
+		{
+			data.mInitState = CONSTRUCTING;
+			data.mSingletonInstance = new DERIVED_TYPE(); 
+			data.mInitState = INITIALIZING;
+			data.mSingletonInstance->initSingleton(); 
+			data.mInitState = INITIALIZED;	
+		}
+		
+		return data.mSingletonInstance;
+	}
+
+	// Reference version of getInstance()
+	// Preferred over getInstance() as it disallows checking for NULL
+	static DERIVED_TYPE& instance()
+	{
+		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()
+	{
+		return getData().mInitState == DELETED;
+	}
+
+private:
+	virtual void initSingleton() {}
+};
+
+#endif