4 files changed, 88 insertions, 10 deletions

diff --git a/indra/llcommon/CMakeLists.txt b/indra/llcommon/CMakeLists.txt
index 410cd0f6b2..7fe4491a8b 100644
--- a/indra/llcommon/CMakeLists.txt
+++ b/indra/llcommon/CMakeLists.txt
@@ -74,6 +74,7 @@ set(llcommon_SOURCE_FILES
     llsdserialize_xml.cpp
     llsdutil.cpp
     llsecondlifeurls.cpp
+    llsingleton.cpp
     llstat.cpp
     llstacktrace.cpp
     llstreamtools.cpp
diff --git a/indra/llcommon/llevents.cpp b/indra/llcommon/llevents.cpp
index c2fa79a524..aec9acc7ef 100644
--- a/indra/llcommon/llevents.cpp
+++ b/indra/llcommon/llevents.cpp
@@ -59,14 +59,12 @@ const char* queue_names[] =
 /*****************************************************************************
 *   If there's a "mainloop" pump, listen on that to flush all LLEventQueues
 *****************************************************************************/
-struct RegisterFlush
+struct RegisterFlush : public LLEventTrackable
 {
     RegisterFlush():
-        pumps(LLEventPumps::instance()),
-        mainloop(pumps.obtain("mainloop")),
-        name("flushLLEventQueues")
+        pumps(LLEventPumps::instance())
     {
-        mainloop.listen(name, boost::bind(&RegisterFlush::flush, this, _1));
+        pumps.obtain("mainloop").listen("flushLLEventQueues", boost::bind(&RegisterFlush::flush, this, _1));
     }
     bool flush(const LLSD&)
     {
@@ -75,11 +73,9 @@ struct RegisterFlush
     }
     ~RegisterFlush()
     {
-        mainloop.stopListening(name);
+        // LLEventTrackable handles stopListening for us.
     }
     LLEventPumps& pumps;
-    LLEventPump& mainloop;
-    const std::string name;
 };
 static RegisterFlush registerFlush;
 
diff --git a/indra/llcommon/llsingleton.cpp b/indra/llcommon/llsingleton.cpp
new file mode 100644
index 0000000000..6b5feaf1c4
--- /dev/null
+++ b/indra/llcommon/llsingleton.cpp
@@ -0,0 +1,38 @@
+/** 
+ * @file llsingleton.cpp
+ * @author Brad Kittenbrink
+ *
+ * $LicenseInfo:firstyear=2009&license=viewergpl$
+ * 
+ * Copyright (c) 2009-2009, 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.
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "llsingleton.h"
+
+std::map<std::string, void *> * LLSingletonRegistry::sSingletonMap = NULL;
+
diff --git a/indra/llcommon/llsingleton.h b/indra/llcommon/llsingleton.h
index 2e7d845bf7..f55fafadd8 100644
--- a/indra/llcommon/llsingleton.h
+++ b/indra/llcommon/llsingleton.h
@@ -33,7 +33,41 @@
 
 #include "llerror.h"	// *TODO: eliminate this
 
+#include <typeinfo>
 #include <boost/noncopyable.hpp>
+#include <boost/any.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
@@ -107,8 +141,17 @@ 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()