23 files changed, 3017 insertions, 679 deletions

diff --git a/indra/llcommon/CMakeLists.txt b/indra/llcommon/CMakeLists.txt
index 16e2a0e5c8..60d4cfe6d3 100644
--- a/indra/llcommon/CMakeLists.txt
+++ b/indra/llcommon/CMakeLists.txt
@@ -31,6 +31,7 @@ set(llcommon_SOURCE_FILES
     llallocator_heap_profile.cpp
     llapp.cpp
     llapr.cpp
+    llaprpool.cpp
     llassettype.cpp
     llavatarname.cpp
     llbase32.cpp
@@ -80,6 +81,7 @@ set(llcommon_SOURCE_FILES
     llrand.cpp
     llrefcount.cpp
     llrun.cpp
+    llscopedvolatileaprpool.h
     llsd.cpp
     llsdserialize.cpp
     llsdserialize_xml.cpp
@@ -122,6 +124,7 @@ set(llcommon_HEADER_FILES
     llavatarname.h
     llapp.h
     llapr.h
+    llaprpool.h
     llassettype.h
     llassoclist.h
     llavatarconstants.h
diff --git a/indra/llcommon/llapp.cpp b/indra/llcommon/llapp.cpp
index ed192a9975..a8b7106078 100644
--- a/indra/llcommon/llapp.cpp
+++ b/indra/llcommon/llapp.cpp
@@ -137,10 +137,6 @@ void LLApp::commonCtor()
 		mOptions.append(sd);
 	}
 
-	// Make sure we clean up APR when we exit
-	// Don't need to do this if we're cleaning up APR in the destructor
-	//atexit(ll_cleanup_apr);
-
 	// Set the application to this instance.
 	sApplication = this;
 	
diff --git a/indra/llcommon/llapr.cpp b/indra/llcommon/llapr.cpp
index d1c44c9403..1e4a51102e 100644
--- a/indra/llcommon/llapr.cpp
+++ b/indra/llcommon/llapr.cpp
@@ -29,212 +29,8 @@
 #include "linden_common.h"
 #include "llapr.h"
 #include "apr_dso.h"
+#include "llscopedvolatileaprpool.h"
 
-apr_pool_t *gAPRPoolp = NULL; // Global APR memory pool
-LLVolatileAPRPool *LLAPRFile::sAPRFilePoolp = NULL ; //global volatile APR memory pool.
-apr_thread_mutex_t *gLogMutexp = NULL;
-apr_thread_mutex_t *gCallStacksLogMutexp = NULL;
-
-const S32 FULL_VOLATILE_APR_POOL = 1024 ; //number of references to LLVolatileAPRPool
-
-void ll_init_apr()
-{
-	if (!gAPRPoolp)
-	{
-		// Initialize APR and create the global pool
-		apr_initialize();
-		apr_pool_create(&gAPRPoolp, NULL);
-		
-		// Initialize the logging mutex
-		apr_thread_mutex_create(&gLogMutexp, APR_THREAD_MUTEX_UNNESTED, gAPRPoolp);
-		apr_thread_mutex_create(&gCallStacksLogMutexp, APR_THREAD_MUTEX_UNNESTED, gAPRPoolp);
-	}
-
-	if(!LLAPRFile::sAPRFilePoolp)
-	{
-		LLAPRFile::sAPRFilePoolp = new LLVolatileAPRPool(FALSE) ;
-	}
-}
-
-
-void ll_cleanup_apr()
-{
-	LL_INFOS("APR") << "Cleaning up APR" << LL_ENDL;
-
-	if (gLogMutexp)
-	{
-		// Clean up the logging mutex
-
-		// All other threads NEED to be done before we clean up APR, so this is okay.
-		apr_thread_mutex_destroy(gLogMutexp);
-		gLogMutexp = NULL;
-	}
-	if (gCallStacksLogMutexp)
-	{
-		// Clean up the logging mutex
-
-		// All other threads NEED to be done before we clean up APR, so this is okay.
-		apr_thread_mutex_destroy(gCallStacksLogMutexp);
-		gCallStacksLogMutexp = NULL;
-	}
-	if (gAPRPoolp)
-	{
-		apr_pool_destroy(gAPRPoolp);
-		gAPRPoolp = NULL;
-	}
-	if (LLAPRFile::sAPRFilePoolp)
-	{
-		delete LLAPRFile::sAPRFilePoolp ;
-		LLAPRFile::sAPRFilePoolp = NULL ;
-	}
-	apr_terminate();
-}
-
-//
-//
-//LLAPRPool
-//
-LLAPRPool::LLAPRPool(apr_pool_t *parent, apr_size_t size, BOOL releasePoolFlag) 	
-	: mParent(parent),
-	mReleasePoolFlag(releasePoolFlag),
-	mMaxSize(size),
-	mPool(NULL)
-{	
-	createAPRPool() ;
-}
-
-LLAPRPool::~LLAPRPool() 
-{
-	releaseAPRPool() ;
-}
-
-void LLAPRPool::createAPRPool()
-{
-	if(mPool)
-	{
-		return ;
-	}
-
-	mStatus = apr_pool_create(&mPool, mParent);
-	ll_apr_warn_status(mStatus) ;
-
-	if(mMaxSize > 0) //size is the number of blocks (which is usually 4K), NOT bytes.
-	{
-		apr_allocator_t *allocator = apr_pool_allocator_get(mPool); 
-		if (allocator) 
-		{ 
-			apr_allocator_max_free_set(allocator, mMaxSize) ;
-		}
-	}
-}
-
-void LLAPRPool::releaseAPRPool()
-{
-	if(!mPool)
-	{
-		return ;
-	}
-
-	if(!mParent || mReleasePoolFlag)
-	{
-		apr_pool_destroy(mPool) ;
-		mPool = NULL ;
-	}
-}
-
-//virtual
-apr_pool_t* LLAPRPool::getAPRPool() 
-{	
-	return mPool ; 
-}
-
-LLVolatileAPRPool::LLVolatileAPRPool(BOOL is_local, apr_pool_t *parent, apr_size_t size, BOOL releasePoolFlag) 
-				  : LLAPRPool(parent, size, releasePoolFlag),
-				  mNumActiveRef(0),
-				  mNumTotalRef(0),
-				  mMutexPool(NULL),
-				  mMutexp(NULL)
-{
-	//create mutex
-	if(!is_local) //not a local apr_pool, that is: shared by multiple threads.
-	{
-		apr_pool_create(&mMutexPool, NULL); // Create a pool for mutex
-		apr_thread_mutex_create(&mMutexp, APR_THREAD_MUTEX_UNNESTED, mMutexPool);
-	}
-}
-
-LLVolatileAPRPool::~LLVolatileAPRPool()
-{
-	//delete mutex
-	if(mMutexp)
-	{
-		apr_thread_mutex_destroy(mMutexp);
-		apr_pool_destroy(mMutexPool);
-	}
-}
-
-//
-//define this virtual function to avoid any mistakenly calling LLAPRPool::getAPRPool().
-//
-//virtual 
-apr_pool_t* LLVolatileAPRPool::getAPRPool() 
-{
-	return LLVolatileAPRPool::getVolatileAPRPool() ;
-}
-
-apr_pool_t* LLVolatileAPRPool::getVolatileAPRPool() 
-{	
-	LLScopedLock lock(mMutexp) ;
-
-	mNumTotalRef++ ;
-	mNumActiveRef++ ;
-
-	if(!mPool)
-	{
-		createAPRPool() ;
-	}
-	
-	return mPool ;
-}
-
-void LLVolatileAPRPool::clearVolatileAPRPool() 
-{
-	LLScopedLock lock(mMutexp) ;
-
-	if(mNumActiveRef > 0)
-	{
-		mNumActiveRef--;
-		if(mNumActiveRef < 1)
-		{
-			if(isFull()) 
-			{
-				mNumTotalRef = 0 ;
-
-				//destroy the apr_pool.
-				releaseAPRPool() ;
-			}
-			else 
-			{
-				//This does not actually free the memory, 
-				//it just allows the pool to re-use this memory for the next allocation. 
-				apr_pool_clear(mPool) ;
-			}
-		}
-	}
-	else
-	{
-		llassert_always(mNumActiveRef > 0) ;
-	}
-
-	//paranoia check if the pool is jammed.
-	//will remove the check before going to release.
-	llassert_always(mNumTotalRef < (FULL_VOLATILE_APR_POOL << 2)) ;
-}
-
-BOOL LLVolatileAPRPool::isFull()
-{
-	return mNumTotalRef > FULL_VOLATILE_APR_POOL ;
-}
 //---------------------------------------------------------------------
 //
 // LLScopedLock
@@ -313,15 +109,17 @@ void ll_apr_assert_status(apr_status_t status, apr_dso_handle_t *handle)
 //
 LLAPRFile::LLAPRFile()
 	: mFile(NULL),
-	  mCurrentFilePoolp(NULL)
+	  mVolatileFilePoolp(NULL),
+	  mRegularFilePoolp(NULL)
 {
 }
 
-LLAPRFile::LLAPRFile(const std::string& filename, apr_int32_t flags, LLVolatileAPRPool* pool)
+LLAPRFile::LLAPRFile(std::string const& filename, apr_int32_t flags, S32* sizep, access_t access_type)
 	: mFile(NULL),
-	  mCurrentFilePoolp(NULL)
+	  mVolatileFilePoolp(NULL),
+	  mRegularFilePoolp(NULL)
 {
-	open(filename, flags, pool);
+	open(filename, flags, access_type, sizep);
 }
 
 LLAPRFile::~LLAPRFile()
@@ -338,36 +136,58 @@ apr_status_t LLAPRFile::close()
 		mFile = NULL ;
 	}
 
-	if(mCurrentFilePoolp)
+	if (mVolatileFilePoolp)
 	{
-		mCurrentFilePoolp->clearVolatileAPRPool() ;
-		mCurrentFilePoolp = NULL ;
+		mVolatileFilePoolp->clearVolatileAPRPool() ;
+		mVolatileFilePoolp = NULL ;
+	}
+
+	if (mRegularFilePoolp)
+	{
+		delete mRegularFilePoolp;
+		mRegularFilePoolp = NULL;
 	}
 
 	return ret ;
 }
 
-apr_status_t LLAPRFile::open(const std::string& filename, apr_int32_t flags, LLVolatileAPRPool* pool, S32* sizep)
+apr_status_t LLAPRFile::open(std::string const& filename, apr_int32_t flags, access_t access_type, S32* sizep)
 {
-	apr_status_t s ;
-
-	//check if already open some file
-	llassert_always(!mFile) ;
-	llassert_always(!mCurrentFilePoolp) ;
-	
-	apr_pool_t* apr_pool = pool ? pool->getVolatileAPRPool() : NULL ;
-	s = apr_file_open(&mFile, filename.c_str(), flags, APR_OS_DEFAULT, getAPRFilePool(apr_pool));
+	llassert_always(!mFile);
+	llassert_always(!mVolatileFilePoolp && !mRegularFilePoolp);
 
-	if (s != APR_SUCCESS || !mFile)
+	apr_status_t status;
+	{
+		apr_pool_t* apr_file_open_pool;	// The use of apr_pool_t is OK here.
+										// This is a temporary variable for a pool that is passed directly to apr_file_open below.
+		if (access_type == short_lived)
+		{
+			// Use a "volatile" thread-local pool.
+			mVolatileFilePoolp = &LLThreadLocalData::tldata().mVolatileAPRPool;
+			// Access the pool and increment its reference count.
+			// The reference count of LLVolatileAPRPool objects will be decremented
+			// again in LLAPRFile::close by calling mVolatileFilePoolp->clearVolatileAPRPool().
+			apr_file_open_pool = mVolatileFilePoolp->getVolatileAPRPool();
+		}
+		else
+		{
+			mRegularFilePoolp = new LLAPRPool(LLThreadLocalData::tldata().mRootPool);
+			apr_file_open_pool = (*mRegularFilePoolp)();
+		}
+		status = apr_file_open(&mFile, filename.c_str(), flags, APR_OS_DEFAULT, apr_file_open_pool);
+	}
+	if (status != APR_SUCCESS || !mFile)
 	{
 		mFile = NULL ;
-		
+		close() ;
 		if (sizep)
 		{
 			*sizep = 0;
 		}
+		return status;
 	}
-	else if (sizep)
+
+	if (sizep)
 	{
 		S32 file_size = 0;
 		apr_off_t offset = 0;
@@ -381,49 +201,7 @@ apr_status_t LLAPRFile::open(const std::string& filename, apr_int32_t flags, LLV
 		*sizep = file_size;
 	}
 
-	if(!mCurrentFilePoolp)
-	{
-		mCurrentFilePoolp = pool ;
-
-		if(!mFile)
-		{
-			close() ;
-		}
-	}
-
-	return s ;
-}
-
-//use gAPRPoolp.
-apr_status_t LLAPRFile::open(const std::string& filename, apr_int32_t flags, BOOL use_global_pool)
-{
-	apr_status_t s;
-
-	//check if already open some file
-	llassert_always(!mFile) ;
-	llassert_always(!mCurrentFilePoolp) ;
-	llassert_always(use_global_pool) ; //be aware of using gAPRPoolp.
-	
-	s = apr_file_open(&mFile, filename.c_str(), flags, APR_OS_DEFAULT, gAPRPoolp);
-	if (s != APR_SUCCESS || !mFile)
-	{
-		mFile = NULL ;
-		close() ;
-		return s;
-	}
-
-	return s;
-}
-
-apr_pool_t* LLAPRFile::getAPRFilePool(apr_pool_t* pool)
-{	
-	if(!pool)
-	{
-		mCurrentFilePoolp = sAPRFilePoolp ;
-		return mCurrentFilePoolp->getVolatileAPRPool() ;
-	}
-
-	return pool ;
+	return status;
 }
 
 // File I/O
@@ -482,45 +260,6 @@ S32 LLAPRFile::seek(apr_seek_where_t where, S32 offset)
 //
 
 //static
-apr_status_t LLAPRFile::close(apr_file_t* file_handle, LLVolatileAPRPool* pool) 
-{
-	apr_status_t ret = APR_SUCCESS ;
-	if(file_handle)
-	{
-		ret = apr_file_close(file_handle);
-		file_handle = NULL ;
-	}
-
-	if(pool)
-	{
-		pool->clearVolatileAPRPool() ;
-	}
-
-	return ret ;
-}
-
-//static
-apr_file_t* LLAPRFile::open(const std::string& filename, LLVolatileAPRPool* pool, apr_int32_t flags)
-{
-	apr_status_t s;
-	apr_file_t* file_handle ;
-
-	pool = pool ? pool : LLAPRFile::sAPRFilePoolp ;
-
-	s = apr_file_open(&file_handle, filename.c_str(), flags, APR_OS_DEFAULT, pool->getVolatileAPRPool());
-	if (s != APR_SUCCESS || !file_handle)
-	{
-		ll_apr_warn_status(s);
-		LL_WARNS("APR") << " Attempting to open filename: " << filename << LL_ENDL;
-		file_handle = NULL ;
-		close(file_handle, pool) ;
-		return NULL;
-	}
-
-	return file_handle ;
-}
-
-//static
 S32 LLAPRFile::seek(apr_file_t* file_handle, apr_seek_where_t where, S32 offset)
 {
 	if(!file_handle)
@@ -553,13 +292,15 @@ S32 LLAPRFile::seek(apr_file_t* file_handle, apr_seek_where_t where, S32 offset)
 }
 
 //static
-S32 LLAPRFile::readEx(const std::string& filename, void *buf, S32 offset, S32 nbytes, LLVolatileAPRPool* pool)
+S32 LLAPRFile::readEx(const std::string& filename, void *buf, S32 offset, S32 nbytes)
 {
-	//*****************************************
-	apr_file_t* file_handle = open(filename, pool, APR_READ|APR_BINARY); 
-	//*****************************************	
-	if (!file_handle)
+	apr_file_t* file_handle;
+	LLScopedVolatileAPRPool pool;
+	apr_status_t s = apr_file_open(&file_handle, filename.c_str(), APR_READ|APR_BINARY, APR_OS_DEFAULT, pool);
+	if (s != APR_SUCCESS || !file_handle)
 	{
+		ll_apr_warn_status(s);
+		LL_WARNS("APR") << " while attempting to open file \"" << filename << '"' << LL_ENDL;
 		return 0;
 	}
 
@@ -589,14 +330,13 @@ S32 LLAPRFile::readEx(const std::string& filename, void *buf, S32 offset, S32 nb
 		}
 	}
 	
-	//*****************************************
-	close(file_handle, pool) ; 
-	//*****************************************
+	apr_file_close(file_handle);
+
 	return (S32)bytes_read;
 }
 
 //static
-S32 LLAPRFile::writeEx(const std::string& filename, void *buf, S32 offset, S32 nbytes, LLVolatileAPRPool* pool)
+S32 LLAPRFile::writeEx(const std::string& filename, void *buf, S32 offset, S32 nbytes)
 {
 	apr_int32_t flags = APR_CREATE|APR_WRITE|APR_BINARY;
 	if (offset < 0)
@@ -605,11 +345,13 @@ S32 LLAPRFile::writeEx(const std::string& filename, void *buf, S32 offset, S32 n
 		offset = 0;
 	}
 	
-	//*****************************************
-	apr_file_t* file_handle = open(filename, pool, flags);
-	//*****************************************
-	if (!file_handle)
+	apr_file_t* file_handle;
+	LLScopedVolatileAPRPool pool;
+	apr_status_t s = apr_file_open(&file_handle, filename.c_str(), flags, APR_OS_DEFAULT, pool);
+	if (s != APR_SUCCESS || !file_handle)
 	{
+		ll_apr_warn_status(s);
+		LL_WARNS("APR") << " while attempting to open file \"" << filename << '"' << LL_ENDL;
 		return 0;
 	}
 
@@ -639,21 +381,18 @@ S32 LLAPRFile::writeEx(const std::string& filename, void *buf, S32 offset, S32 n
 		}
 	}
 
-	//*****************************************
-	LLAPRFile::close(file_handle, pool);
-	//*****************************************
+	apr_file_close(file_handle);
 
 	return (S32)bytes_written;
 }
 
 //static
-bool LLAPRFile::remove(const std::string& filename, LLVolatileAPRPool* pool)
+bool LLAPRFile::remove(const std::string& filename)
 {
 	apr_status_t s;
 
-	pool = pool ? pool : LLAPRFile::sAPRFilePoolp ;
-	s = apr_file_remove(filename.c_str(), pool->getVolatileAPRPool());
-	pool->clearVolatileAPRPool() ;
+	LLScopedVolatileAPRPool pool;
+	s = apr_file_remove(filename.c_str(), pool);
 
 	if (s != APR_SUCCESS)
 	{
@@ -665,13 +404,12 @@ bool LLAPRFile::remove(const std::string& filename, LLVolatileAPRPool* pool)
 }
 
 //static
-bool LLAPRFile::rename(const std::string& filename, const std::string& newname, LLVolatileAPRPool* pool)
+bool LLAPRFile::rename(const std::string& filename, const std::string& newname)
 {
 	apr_status_t s;
 
-	pool = pool ? pool : LLAPRFile::sAPRFilePoolp ;
-	s = apr_file_rename(filename.c_str(), newname.c_str(), pool->getVolatileAPRPool());
-	pool->clearVolatileAPRPool() ;
+	LLScopedVolatileAPRPool pool;
+	s = apr_file_rename(filename.c_str(), newname.c_str(), pool);
 	
 	if (s != APR_SUCCESS)
 	{
@@ -683,49 +421,44 @@ bool LLAPRFile::rename(const std::string& filename, const std::string& newname,
 }
 
 //static
-bool LLAPRFile::isExist(const std::string& filename, LLVolatileAPRPool* pool, apr_int32_t flags)
+bool LLAPRFile::isExist(const std::string& filename, apr_int32_t flags)
 {
-	apr_file_t* apr_file;
+	apr_file_t* file_handle;
 	apr_status_t s;
 
-	pool = pool ? pool : LLAPRFile::sAPRFilePoolp ;
-	s = apr_file_open(&apr_file, filename.c_str(), flags, APR_OS_DEFAULT, pool->getVolatileAPRPool());	
+	LLScopedVolatileAPRPool pool;
+	s = apr_file_open(&file_handle, filename.c_str(), flags, APR_OS_DEFAULT, pool);
 
-	if (s != APR_SUCCESS || !apr_file)
+	if (s != APR_SUCCESS || !file_handle)
 	{
-		pool->clearVolatileAPRPool() ;
 		return false;
 	}
 	else
 	{
-		apr_file_close(apr_file) ;
-		pool->clearVolatileAPRPool() ;
+		apr_file_close(file_handle);
 		return true;
 	}
 }
 
 //static
-S32 LLAPRFile::size(const std::string& filename, LLVolatileAPRPool* pool)
+S32 LLAPRFile::size(const std::string& filename)
 {
-	apr_file_t* apr_file;
+	apr_file_t* file_handle;
 	apr_finfo_t info;
 	apr_status_t s;
 	
-	pool = pool ? pool : LLAPRFile::sAPRFilePoolp ;
-	s = apr_file_open(&apr_file, filename.c_str(), APR_READ, APR_OS_DEFAULT, pool->getVolatileAPRPool());
+	LLScopedVolatileAPRPool pool;
+	s = apr_file_open(&file_handle, filename.c_str(), APR_READ, APR_OS_DEFAULT, pool);
 	
-	if (s != APR_SUCCESS || !apr_file)
+	if (s != APR_SUCCESS || !file_handle)
 	{		
-		pool->clearVolatileAPRPool() ;
-		
 		return 0;
 	}
 	else
 	{
-		apr_status_t s = apr_file_info_get(&info, APR_FINFO_SIZE, apr_file);		
+		apr_status_t s = apr_file_info_get(&info, APR_FINFO_SIZE, file_handle);
 
-		apr_file_close(apr_file) ;
-		pool->clearVolatileAPRPool() ;
+		apr_file_close(file_handle) ;
 		
 		if (s == APR_SUCCESS)
 		{
@@ -739,31 +472,29 @@ S32 LLAPRFile::size(const std::string& filename, LLVolatileAPRPool* pool)
 }
 
 //static
-bool LLAPRFile::makeDir(const std::string& dirname, LLVolatileAPRPool* pool)
+bool LLAPRFile::makeDir(const std::string& dirname)
 {
 	apr_status_t s;
 
-	pool = pool ? pool : LLAPRFile::sAPRFilePoolp ;
-	s = apr_dir_make(dirname.c_str(), APR_FPROT_OS_DEFAULT, pool->getVolatileAPRPool());
-	pool->clearVolatileAPRPool() ;
+	LLScopedVolatileAPRPool pool;
+	s = apr_dir_make(dirname.c_str(), APR_FPROT_OS_DEFAULT, pool);
 		
 	if (s != APR_SUCCESS)
 	{
 		ll_apr_warn_status(s);
-		LL_WARNS("APR") << " Attempting to make directory: " << dirname << LL_ENDL;
+		LL_WARNS("APR") << " while attempting to make directory: " << dirname << LL_ENDL;
 		return false;
 	}
 	return true;
 }
 
 //static
-bool LLAPRFile::removeDir(const std::string& dirname, LLVolatileAPRPool* pool)
+bool LLAPRFile::removeDir(const std::string& dirname)
 {
 	apr_status_t s;
 
-	pool = pool ? pool : LLAPRFile::sAPRFilePoolp ;
-	s = apr_file_remove(dirname.c_str(), pool->getVolatileAPRPool());
-	pool->clearVolatileAPRPool() ;
+	LLScopedVolatileAPRPool pool;
+	s = apr_file_remove(dirname.c_str(), pool);
 	
 	if (s != APR_SUCCESS)
 	{
diff --git a/indra/llcommon/llapr.h b/indra/llcommon/llapr.h
index af33ce666f..3f846f1314 100644
--- a/indra/llcommon/llapr.h
+++ b/indra/llcommon/llapr.h
@@ -50,71 +50,9 @@
 #include "apr_atomic.h"
 #include "llstring.h"
 
-extern LL_COMMON_API apr_thread_mutex_t* gLogMutexp;
-extern apr_thread_mutex_t* gCallStacksLogMutexp;
-
 struct apr_dso_handle_t;
-
-/** 
- * @brief initialize the common apr constructs -- apr itself, the
- * global pool, and a mutex.
- */
-void LL_COMMON_API ll_init_apr();
-
-/** 
- * @brief Cleanup those common apr constructs.
- */
-void LL_COMMON_API ll_cleanup_apr();
-
-//
-//LL apr_pool
-//manage apr_pool_t, destroy allocated apr_pool in the destruction function.
-//
-class LL_COMMON_API LLAPRPool
-{
-public:
-	LLAPRPool(apr_pool_t *parent = NULL, apr_size_t size = 0, BOOL releasePoolFlag = TRUE) ;
-	virtual ~LLAPRPool() ;
-
-	virtual apr_pool_t* getAPRPool() ;
-	apr_status_t getStatus() {return mStatus ; }
-
-protected:
-	void releaseAPRPool() ;
-	void createAPRPool() ;
-
-protected:
-	apr_pool_t*  mPool ;              //pointing to an apr_pool
-	apr_pool_t*  mParent ;			  //parent pool
-	apr_size_t   mMaxSize ;           //max size of mPool, mPool should return memory to system if allocated memory beyond this limit. However it seems not to work.
-	apr_status_t mStatus ;            //status when creating the pool
-	BOOL         mReleasePoolFlag ;   //if set, mPool is destroyed when LLAPRPool is deleted. default value is true.
-};
-
-//
-//volatile LL apr_pool
-//which clears memory automatically.
-//so it can not hold static data or data after memory is cleared
-//
-class LL_COMMON_API LLVolatileAPRPool : public LLAPRPool
-{
-public:
-	LLVolatileAPRPool(BOOL is_local = TRUE, apr_pool_t *parent = NULL, apr_size_t size = 0, BOOL releasePoolFlag = TRUE);
-	virtual ~LLVolatileAPRPool();
-
-	/*virtual*/ apr_pool_t* getAPRPool() ; //define this virtual function to avoid any mistakenly calling LLAPRPool::getAPRPool().
-	apr_pool_t* getVolatileAPRPool() ;	
-	void        clearVolatileAPRPool() ;
-
-	BOOL        isFull() ;
-	
-private:
-	S32 mNumActiveRef ; //number of active pointers pointing to the apr_pool.
-	S32 mNumTotalRef ;  //number of total pointers pointing to the apr_pool since last creating.  
-
-	apr_thread_mutex_t *mMutexp;
-	apr_pool_t         *mMutexPool;
-} ;
+class LLAPRPool;
+class LLVolatileAPRPool;
 
 /** 
  * @class LLScopedLock
@@ -205,15 +143,20 @@ class LL_COMMON_API LLAPRFile : boost::noncopyable
 	// make this non copyable since a copy closes the file
 private:
 	apr_file_t* mFile ;
-	LLVolatileAPRPool *mCurrentFilePoolp ; //currently in use apr_pool, could be one of them: sAPRFilePoolp, or a temp pool. 
+	LLVolatileAPRPool* mVolatileFilePoolp;	// (Thread local) APR pool currently in use.
+	LLAPRPool* mRegularFilePoolp;		// ...or a regular pool.
 
 public:
+	enum access_t {
+		long_lived,		// Use a global pool for long-lived file accesses.
+		short_lived		// Use a volatile pool for short-lived file accesses.
+	};
+
 	LLAPRFile() ;
-	LLAPRFile(const std::string& filename, apr_int32_t flags, LLVolatileAPRPool* pool = NULL);
+	LLAPRFile(std::string const& filename, apr_int32_t flags, S32* sizep = NULL, access_t access_type = short_lived);
 	~LLAPRFile() ;
-	
-	apr_status_t open(const std::string& filename, apr_int32_t flags, LLVolatileAPRPool* pool = NULL, S32* sizep = NULL);
-	apr_status_t open(const std::string& filename, apr_int32_t flags, BOOL use_global_pool); //use gAPRPoolp.
+
+	apr_status_t open(const std::string& filename, apr_int32_t flags, access_t access_type, S32* sizep = NULL);
 	apr_status_t close() ;
 
 	// Returns actual offset, -1 if seek fails
@@ -226,32 +169,24 @@ public:
 	
 	apr_file_t* getFileHandle() {return mFile;}	
 
-private:
-	apr_pool_t* getAPRFilePool(apr_pool_t* pool) ;	
-	
 //
 //*******************************************************************************************************************************
 //static components
 //
-public:
-	static LLVolatileAPRPool *sAPRFilePoolp ; //a global apr_pool for APRFile, which is used only when local pool does not exist.
-
 private:
-	static apr_file_t* open(const std::string& filename, LLVolatileAPRPool* pool, apr_int32_t flags);
-	static apr_status_t close(apr_file_t* file, LLVolatileAPRPool* pool) ;
 	static S32 seek(apr_file_t* file, apr_seek_where_t where, S32 offset);
 public:
 	// returns false if failure:
-	static bool remove(const std::string& filename, LLVolatileAPRPool* pool = NULL);
-	static bool rename(const std::string& filename, const std::string& newname, LLVolatileAPRPool* pool = NULL);
-	static bool isExist(const std::string& filename, LLVolatileAPRPool* pool = NULL, apr_int32_t flags = APR_READ);
-	static S32 size(const std::string& filename, LLVolatileAPRPool* pool = NULL);
-	static bool makeDir(const std::string& dirname, LLVolatileAPRPool* pool = NULL);
-	static bool removeDir(const std::string& dirname, LLVolatileAPRPool* pool = NULL);
+	static bool remove(const std::string& filename);
+	static bool rename(const std::string& filename, const std::string& newname);
+	static bool isExist(const std::string& filename, apr_int32_t flags = APR_READ);
+	static S32 size(const std::string& filename);
+	static bool makeDir(const std::string& dirname);
+	static bool removeDir(const std::string& dirname);
 
 	// Returns bytes read/written, 0 if read/write fails:
-	static S32 readEx(const std::string& filename, void *buf, S32 offset, S32 nbytes, LLVolatileAPRPool* pool = NULL);	
-	static S32 writeEx(const std::string& filename, void *buf, S32 offset, S32 nbytes, LLVolatileAPRPool* pool = NULL); // offset<0 means append
+	static S32 readEx(const std::string& filename, void *buf, S32 offset, S32 nbytes);	
+	static S32 writeEx(const std::string& filename, void *buf, S32 offset, S32 nbytes); // offset<0 means append
 //*******************************************************************************************************************************
 };
 
@@ -267,6 +202,4 @@ bool LL_COMMON_API ll_apr_warn_status(apr_status_t status, apr_dso_handle_t* han
 void LL_COMMON_API ll_apr_assert_status(apr_status_t status);
 void LL_COMMON_API ll_apr_assert_status(apr_status_t status, apr_dso_handle_t* handle);
 
-extern "C" LL_COMMON_API apr_pool_t* gAPRPoolp; // Global APR memory pool
-
 #endif // LL_LLAPR_H
diff --git a/indra/llcommon/llaprpool.cpp b/indra/llcommon/llaprpool.cpp
new file mode 100644
index 0000000000..6f21b61b65
--- /dev/null
+++ b/indra/llcommon/llaprpool.cpp
@@ -0,0 +1,202 @@
+/**
+ * @file llaprpool.cpp
+ *
+ * $LicenseInfo:firstyear=2011&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2011, 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
+ * $/LicenseInfo$
+ *
+ * CHANGELOG
+ *   and additional copyright holders.
+ *
+ *   04/04/2010
+ *   - Initial version, written by Aleric Inglewood @ SL
+ *
+ *   10/11/2010
+ *   - Added APR_HAS_THREADS #if's to allow creation and destruction
+ *     of subpools by threads other than the parent pool owner.
+ */
+
+#include "linden_common.h"
+
+#include "llerror.h"
+#include "llaprpool.h"
+#include "llthread.h"
+
+// Create a subpool from parent.
+void LLAPRPool::create(LLAPRPool& parent)
+{
+	llassert(!mPool);			// Must be non-initialized.
+	mParent = &parent;
+	if (!mParent)				// Using the default parameter?
+	{
+		// By default use the root pool of the current thread.
+		mParent = &LLThreadLocalData::tldata().mRootPool;
+	}
+	llassert(mParent->mPool);	// Parent must be initialized.
+#if APR_HAS_THREADS
+	// As per the documentation of APR (ie http://apr.apache.org/docs/apr/1.4/apr__pools_8h.html):
+	//
+	// Note that most operations on pools are not thread-safe: a single pool should only be
+	// accessed by a single thread at any given time. The one exception to this rule is creating
+	// a subpool of a given pool: one or more threads can safely create subpools at the same
+	// time that another thread accesses the parent pool.
+	//
+	// In other words, it's safe for any thread to create a (sub)pool, independent of who
+	// owns the parent pool.
+	mOwner = apr_os_thread_current();
+#else
+	mOwner = mParent->mOwner;
+	llassert(apr_os_thread_equal(mOwner, apr_os_thread_current()));
+#endif
+	apr_status_t const apr_pool_create_status = apr_pool_create(&mPool, mParent->mPool);
+	llassert_always(apr_pool_create_status == APR_SUCCESS);
+	llassert(mPool);			// Initialized.
+	apr_pool_cleanup_register(mPool, this, &s_plain_cleanup, &apr_pool_cleanup_null);
+}
+
+// Destroy the (sub)pool, if any.
+void LLAPRPool::destroy(void)
+{
+	// Only do anything if we are not already (being) destroyed.
+	if (mPool)
+	{
+#if !APR_HAS_THREADS
+		// If we are a root pool, then every thread may destruct us: in that case
+		// we have to assume that no other thread will use this pool concurrently,
+		// of course. Otherwise, if we are a subpool, only the thread that owns
+		// the parent may destruct us, since that is the pool that is still alive,
+		// possibly being used by others and being altered here.
+		llassert(!mParent || apr_os_thread_equal(mParent->mOwner, apr_os_thread_current()));
+#endif
+		apr_pool_t* pool = mPool;	// The use of apr_pool_t is OK here.
+									// Temporary store before destroying the pool.
+		mPool = NULL;				// Mark that we are BEING destructed.
+		apr_pool_cleanup_kill(pool, this, &s_plain_cleanup);
+		apr_pool_destroy(pool);
+	}
+}
+
+bool LLAPRPool::parent_is_being_destructed(void)
+{
+	return mParent && (!mParent->mPool || mParent->parent_is_being_destructed());
+}
+
+LLAPRInitialization::LLAPRInitialization(void)
+{
+	static bool apr_initialized = false;
+
+	if (!apr_initialized)
+	{
+		apr_initialize();
+	}
+
+	apr_initialized = true;
+}
+
+bool LLAPRRootPool::sCountInitialized = false;
+apr_uint32_t volatile LLAPRRootPool::sCount;
+
+apr_thread_mutex_t* gLogMutexp;
+apr_thread_mutex_t* gCallStacksLogMutexp;
+
+LLAPRRootPool::LLAPRRootPool(void) : LLAPRInitialization(), LLAPRPool(0)
+{
+	// sCountInitialized don't need locking because when we get here there is still only a single thread.
+	if (!sCountInitialized)
+	{
+		// Initialize the logging mutex
+		apr_thread_mutex_create(&gLogMutexp, APR_THREAD_MUTEX_UNNESTED, mPool);
+		apr_thread_mutex_create(&gCallStacksLogMutexp, APR_THREAD_MUTEX_UNNESTED, mPool);
+
+		apr_status_t status = apr_atomic_init(mPool);
+		llassert_always(status == APR_SUCCESS);
+		apr_atomic_set32(&sCount, 1);	// Set to 1 to account for the global root pool.
+		sCountInitialized = true;
+
+		// Initialize thread-local APR pool support.
+		// Because this recursively calls LLAPRRootPool::LLAPRRootPool(void)
+		// it must be done last, so that sCount is already initialized.
+		LLThreadLocalData::init();
+	}
+	apr_atomic_inc32(&sCount);
+}
+
+LLAPRRootPool::~LLAPRRootPool()
+{
+	if (!apr_atomic_dec32(&sCount))
+	{
+		// The last pool was destructed. Cleanup remainder of APR.
+		LL_INFOS("APR") << "Cleaning up APR" << LL_ENDL;
+
+		if (gLogMutexp)
+		{
+			// Clean up the logging mutex
+
+			// All other threads NEED to be done before we clean up APR, so this is okay.
+			apr_thread_mutex_destroy(gLogMutexp);
+			gLogMutexp = NULL;
+		}
+		if (gCallStacksLogMutexp)
+		{
+			// Clean up the logging mutex
+
+			// All other threads NEED to be done before we clean up APR, so this is okay.
+			apr_thread_mutex_destroy(gCallStacksLogMutexp);
+			gCallStacksLogMutexp = NULL;
+		}
+
+		// Must destroy ALL, and therefore this last LLAPRRootPool, before terminating APR.
+		static_cast<LLAPRRootPool*>(this)->destroy();
+
+		apr_terminate();
+	}
+}
+
+//static
+// Return a global root pool that is independent of LLThreadLocalData.
+// Normally you should NOT use this. Only use for early initialization
+// (before main) and deinitialization (after main).
+LLAPRRootPool& LLAPRRootPool::get(void)
+{
+  static LLAPRRootPool global_APRpool(0);
+  return global_APRpool;
+}
+
+void LLVolatileAPRPool::clearVolatileAPRPool()
+{
+	llassert_always(mNumActiveRef > 0);
+	if (--mNumActiveRef == 0)
+	{
+		if (isOld())
+		{
+			destroy();
+			mNumTotalRef = 0 ;
+		}
+		else
+		{
+			// This does not actually free the memory,
+			// it just allows the pool to re-use this memory for the next allocation.
+			clear();
+		}
+	}
+
+	// Paranoia check if the pool is jammed.
+	llassert(mNumTotalRef < (FULL_VOLATILE_APR_POOL << 2)) ;
+}
diff --git a/indra/llcommon/llaprpool.h b/indra/llcommon/llaprpool.h
new file mode 100644
index 0000000000..bf4102c584
--- /dev/null
+++ b/indra/llcommon/llaprpool.h
@@ -0,0 +1,256 @@
+/**
+ * @file llaprpool.h
+ * @brief Implementation of LLAPRPool
+ *
+ * $LicenseInfo:firstyear=2011&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2011, 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
+ * $/LicenseInfo$
+ *
+ * CHANGELOG
+ *   and additional copyright holders.
+ *
+ *   04/04/2010
+ *   - Initial version, written by Aleric Inglewood @ SL
+ *
+ *   10/11/2010
+ *   - Added APR_HAS_THREADS #if's to allow creation and destruction
+ *     of subpools by threads other than the parent pool owner.
+ *
+ *   05/02/2011
+ *   - Fixed compilation on windows: Suppress compile warning 4996
+ *     and include <winsock2.h> before including <ws2tcpip.h>,
+ *     by Merov Linden @ SL.
+ */
+
+#ifndef LL_LLAPRPOOL_H
+#define LL_LLAPRPOOL_H
+
+#ifdef LL_WINDOWS
+#pragma warning(push)
+#pragma warning(disable:4996)
+#include <winsock2.h>
+#include <ws2tcpip.h>		// Needed before including apr_portable.h
+#pragma warning(pop)
+#endif
+
+#include "apr_portable.h"
+#include "apr_pools.h"
+#include "llerror.h"
+
+extern void ll_init_apr();
+
+/**
+ * @brief A wrapper around the APR memory pool API.
+ *
+ * Usage of this class should be restricted to passing it to libapr-1 function calls that need it.
+ *
+ */
+class LL_COMMON_API LLAPRPool
+{
+protected:
+	//! Pointer to the underlaying pool. NULL if not initialized.
+	apr_pool_t* mPool;		// The use of apr_pool_t is OK here.
+							// This is the wrapped pointer that it is all about!
+	//! Pointer to the parent pool, if any. Only valid when mPool is non-zero.
+	LLAPRPool* mParent;
+	//! The thread that owns this memory pool. Only valid when mPool is non-zero.
+	apr_os_thread_t mOwner;
+
+public:
+	/// Construct an uninitialized (destructed) pool.
+	LLAPRPool(void) : mPool(NULL) { }
+
+	/// Construct a subpool from an existing pool.
+	/// This is not a copy-constructor, this class doesn't have one!
+	LLAPRPool(LLAPRPool& parent) : mPool(NULL) { create(parent); }
+
+	/// Destruct the memory pool (free all of its subpools and allocated memory).
+	~LLAPRPool() { destroy(); }
+
+protected:
+	/// Create a pool that is allocated from the Operating System. Only used by LLAPRRootPool.
+	LLAPRPool(int) : mPool(NULL), mParent(NULL), mOwner(apr_os_thread_current())
+	{
+		apr_status_t const apr_pool_create_status = apr_pool_create(&mPool, NULL);
+		llassert_always(apr_pool_create_status == APR_SUCCESS);
+		llassert(mPool);
+		apr_pool_cleanup_register(mPool, this, &s_plain_cleanup, &apr_pool_cleanup_null);
+	}
+
+public:
+	/// Create a subpool from parent. May only be called for an uninitialized/destroyed pool.
+	/// The default parameter causes the root pool of the current thread to be used.
+	void create(LLAPRPool& parent = *static_cast<LLAPRPool*>(NULL));
+
+	/// Destroy the (sub)pool, if any.
+	void destroy(void);
+
+	// Use some safebool idiom (http://www.artima.com/cppsource/safebool.html) rather than operator bool.
+	typedef LLAPRPool* const LLAPRPool::* const bool_type;
+	/// Return true if the pool is initialized.
+	operator bool_type() const { return mPool ? &LLAPRPool::mParent : 0; }
+
+	/// Painful, but we have to either provide access to this, or wrap
+	/// every APR function call that needs an apr pool as argument.
+	/// NEVER destroy a pool that is returned by this function!
+	apr_pool_t* operator()(void) const		// The use of apr_pool_t is OK here.
+	  										// This is the accessor for passing the pool to libapr-1 functions.
+	{
+		llassert(mPool);
+		llassert(apr_os_thread_equal(mOwner, apr_os_thread_current()));
+		return mPool;
+	}
+
+	/// Free all memory without destructing the pool.
+	void clear(void)
+	{
+		llassert(mPool);
+		llassert(apr_os_thread_equal(mOwner, apr_os_thread_current()));
+		apr_pool_clear(mPool);
+	}
+
+// These methods would make this class 'complete' (as wrapper around the libapr
+// pool functions), but we don't use memory pools in the viewer (only when
+// we are forced to pass one to a libapr call), so don't define them in order
+// not to encourage people to use them.
+#if 0
+	void* palloc(size_t size)
+	{
+		llassert(mPool);
+		llassert(apr_os_thread_equal(mOwner, apr_os_thread_current()));
+		return apr_palloc(mPool, size);
+	}
+	void* pcalloc(size_t size)
+	{
+		llassert(mPool);
+		llassert(apr_os_thread_equal(mOwner, apr_os_thread_current()));
+		return apr_pcalloc(mPool, size);
+	}
+#endif
+
+private:
+	bool parent_is_being_destructed(void);
+	static apr_status_t s_plain_cleanup(void* userdata) { return static_cast<LLAPRPool*>(userdata)->plain_cleanup(); }
+
+	apr_status_t plain_cleanup(void)
+	{
+		if (mPool && 						// We are not being destructed,
+			parent_is_being_destructed())	// but our parent is.
+		  // This means the pool is being destructed recursively by libapr
+		  // because one of its parents is being destructed.
+		{
+			mPool = NULL;	// Stop destroy() from destructing the pool again.
+		}
+		return APR_SUCCESS;
+	}
+};
+
+class LLAPRInitialization
+{
+public:
+	LLAPRInitialization(void);
+};
+
+/**
+ * @brief Root memory pool (allocates memory from the operating system).
+ *
+ * This class should only be used by LLThreadLocalData
+ * (and LLMutexRootPool when APR_HAS_THREADS isn't defined).
+ */
+class LL_COMMON_API LLAPRRootPool : public LLAPRInitialization, public LLAPRPool
+{
+private:
+	/// Construct a root memory pool. Should only be used by LLThreadLocalData and LLMutexRootPool.
+	friend class LLThreadLocalData;
+#if !APR_HAS_THREADS
+	friend class LLMutexRootPool;
+#endif
+	/// Construct a root memory pool.
+	/// Should only be used by LLThreadLocalData.
+	LLAPRRootPool(void);
+	~LLAPRRootPool();
+
+private:
+	// Keep track of how many root pools exist and when the last one is destructed.
+	static bool sCountInitialized;
+	static apr_uint32_t volatile sCount;
+
+public:
+	// Return a global root pool that is independent of LLThreadLocalData.
+	// Normally you should not use this. Only use for early initialization
+	// (before main) and deinitialization (after main).
+	static LLAPRRootPool& get(void);
+
+#if APR_POOL_DEBUG
+	void grab_ownership(void)
+	{
+		// You need a patched libapr to use this.
+		// See http://web.archiveorange.com/archive/v/5XO9y2zoxUOMt6Gmi1OI
+		apr_pool_owner_set(mPool);
+	}
+#endif
+
+private:
+	// Used for constructing the Special Global Root Pool (returned by LLAPRRootPool::get).
+	// It is the same as the default constructor but omits to increment sCount. As a result,
+	// we must be sure that at least one other LLAPRRootPool is created before termination
+	// of the application (which is the case: we create one LLAPRRootPool per thread).
+	LLAPRRootPool(int) : LLAPRInitialization(), LLAPRPool(0) { }
+};
+
+/** Volatile memory pool
+ *
+ * 'Volatile' APR memory pool which normally only clears memory,
+ * and does not destroy the pool (the same pool is reused) for
+ * greater efficiency. However, as a safe guard the apr pool
+ * is destructed every FULL_VOLATILE_APR_POOL uses to allow
+ * the system memory to be allocated more efficiently and not
+ * get scattered through RAM.
+ */
+class LL_COMMON_API LLVolatileAPRPool : protected LLAPRPool
+{
+public:
+	LLVolatileAPRPool(void) : mNumActiveRef(0), mNumTotalRef(0) { }
+
+	void clearVolatileAPRPool(void);
+
+	bool isOld(void) const { return mNumTotalRef > FULL_VOLATILE_APR_POOL; }
+	bool isUnused() const { return mNumActiveRef == 0; }
+
+private:
+	friend class LLScopedVolatileAPRPool;
+	friend class LLAPRFile;
+	apr_pool_t* getVolatileAPRPool(void)	// The use of apr_pool_t is OK here.
+	{
+		if (!mPool) create();
+		++mNumActiveRef;
+		++mNumTotalRef;
+		return LLAPRPool::operator()();
+	}
+
+private:
+	S32 mNumActiveRef;	// Number of active uses of the pool.
+	S32 mNumTotalRef;	// Number of total uses of the pool since last creation.
+
+	// Maximum number of references to LLVolatileAPRPool until the pool is recreated.
+	static S32 const FULL_VOLATILE_APR_POOL = 1024;
+};
+
+#endif // LL_LLAPRPOOL_H
diff --git a/indra/llcommon/llcommon.cpp b/indra/llcommon/llcommon.cpp
index 8be9e4f4de..b8a7394852 100644
--- a/indra/llcommon/llcommon.cpp
+++ b/indra/llcommon/llcommon.cpp
@@ -31,17 +31,9 @@
 #include "llthread.h"
 
 //static
-BOOL LLCommon::sAprInitialized = FALSE;
-
-//static
 void LLCommon::initClass()
 {
 	LLMemory::initClass();
-	if (!sAprInitialized)
-	{
-		ll_init_apr();
-		sAprInitialized = TRUE;
-	}
 	LLTimer::initClass();
 	LLThreadSafeRefCount::initThreadSafeRefCount();
 // 	LLWorkerThread::initClass();
@@ -55,10 +47,5 @@ void LLCommon::cleanupClass()
 // 	LLWorkerThread::cleanupClass();
 	LLThreadSafeRefCount::cleanupThreadSafeRefCount();
 	LLTimer::cleanupClass();
-	if (sAprInitialized)
-	{
-		ll_cleanup_apr();
-		sAprInitialized = FALSE;
-	}
 	LLMemory::cleanupClass();
 }
diff --git a/indra/llcommon/llcommon.h b/indra/llcommon/llcommon.h
index ca9cad5d05..171590f3d8 100644
--- a/indra/llcommon/llcommon.h
+++ b/indra/llcommon/llcommon.h
@@ -35,8 +35,6 @@ class LL_COMMON_API LLCommon
 public:
 	static void initClass();
 	static void cleanupClass();
-private:
-	static BOOL sAprInitialized;
 };
 
 #endif
diff --git a/indra/llcommon/llerror.cpp b/indra/llcommon/llerror.cpp
index c35799bbb9..bda9d7c177 100644
--- a/indra/llcommon/llerror.cpp
+++ b/indra/llcommon/llerror.cpp
@@ -866,6 +866,9 @@ You get:
 	
 */
 
+extern apr_thread_mutex_t* gLogMutexp;
+extern apr_thread_mutex_t* gCallStacksLogMutexp;
+
 namespace {
 	bool checkLevelMap(const LevelMap& map, const std::string& key,
 						LLError::ELevel& level)
diff --git a/indra/llcommon/llerror.h b/indra/llcommon/llerror.h
index b3e604f8e8..369f2a7a97 100644
--- a/indra/llcommon/llerror.h
+++ b/indra/llcommon/llerror.h
@@ -296,5 +296,4 @@ typedef LLError::NoClassInfo _LL_CLASS_TO_LOG;
 		Such computation is done iff the message will be logged.
 	*/
 
-
 #endif // LL_LLERROR_H
diff --git a/indra/llcommon/llfixedbuffer.cpp b/indra/llcommon/llfixedbuffer.cpp
index d394f179fb..4b5cdbe288 100644
--- a/indra/llcommon/llfixedbuffer.cpp
+++ b/indra/llcommon/llfixedbuffer.cpp
@@ -30,8 +30,7 @@
 
 LLFixedBuffer::LLFixedBuffer(const U32 max_lines)
 	: LLLineBuffer(),
-	  mMaxLines(max_lines),
-	  mMutex(NULL)
+	  mMaxLines(max_lines)
 {
 	mTimer.reset();
 }
diff --git a/indra/llcommon/llmemory.cpp b/indra/llcommon/llmemory.cpp
index 21d1c84d69..8c02ad8290 100644
--- a/indra/llcommon/llmemory.cpp
+++ b/indra/llcommon/llmemory.cpp
@@ -26,14 +26,13 @@
 
 #include "linden_common.h"
 
-#include "llmemory.h"
 
-#if MEM_TRACK_MEM
+//#if MEM_TRACK_MEM
 #include "llthread.h"
-#endif
+//#endif
 
 #if defined(LL_WINDOWS)
-# include <windows.h>
+//# include <windows.h>
 # include <psapi.h>
 #elif defined(LL_DARWIN)
 # include <sys/types.h>
@@ -43,10 +42,24 @@
 # include <unistd.h>
 #endif
 
+#include "llmemory.h"
+
+#include "llsys.h"
+#include "llframetimer.h"
 //----------------------------------------------------------------------------
 
 //static
 char* LLMemory::reserveMem = 0;
+U32 LLMemory::sAvailPhysicalMemInKB = U32_MAX ;
+U32 LLMemory::sMaxPhysicalMemInKB = 0;
+U32 LLMemory::sAllocatedMemInKB = 0;
+U32 LLMemory::sAllocatedPageSizeInKB = 0 ;
+U32 LLMemory::sMaxHeapSizeInKB = U32_MAX ;
+BOOL LLMemory::sEnableMemoryFailurePrevention = FALSE;
+
+#if __DEBUG_PRIVATE_MEM__
+LLPrivateMemoryPoolManager::mem_allocation_info_t LLPrivateMemoryPoolManager::sMemAllocationTracker;
+#endif
 
 //static
 void LLMemory::initClass()
@@ -71,6 +84,148 @@ void LLMemory::freeReserve()
 	reserveMem = NULL;
 }
 
+//static 
+void LLMemory::initMaxHeapSizeGB(F32 max_heap_size_gb, BOOL prevent_heap_failure)
+{
+	sMaxHeapSizeInKB = (U32)(max_heap_size_gb * 1024 * 1024) ;
+	sEnableMemoryFailurePrevention = prevent_heap_failure ;
+}
+
+//static 
+void LLMemory::updateMemoryInfo() 
+{
+#if LL_WINDOWS	
+	HANDLE self = GetCurrentProcess();
+	PROCESS_MEMORY_COUNTERS counters;
+	
+	if (!GetProcessMemoryInfo(self, &counters, sizeof(counters)))
+	{
+		llwarns << "GetProcessMemoryInfo failed" << llendl;
+		return ;
+	}
+
+	sAllocatedMemInKB = (U32)(counters.WorkingSetSize / 1024) ;
+	sAllocatedPageSizeInKB = (U32)(counters.PagefileUsage / 1024) ;
+
+	U32 avail_phys, avail_virtual;
+	LLMemoryInfo::getAvailableMemoryKB(avail_phys, avail_virtual) ;
+	sMaxPhysicalMemInKB = llmin(avail_phys + sAllocatedMemInKB, sMaxHeapSizeInKB);
+
+	if(sMaxPhysicalMemInKB > sAllocatedMemInKB)
+	{
+		sAvailPhysicalMemInKB = sMaxPhysicalMemInKB - sAllocatedMemInKB ;
+	}
+	else
+	{
+		sAvailPhysicalMemInKB = 0 ;
+	}
+#else
+	//not valid for other systems for now.
+	sAllocatedMemInKB = (U32)(LLMemory::getCurrentRSS() / 1024) ;
+	sMaxPhysicalMemInKB = U32_MAX ;
+	sAvailPhysicalMemInKB = U32_MAX ;
+#endif
+
+	return ;
+}
+
+//
+//this function is to test if there is enough space with the size in the virtual address space.
+//it does not do any real allocation
+//if success, it returns the address where the memory chunk can fit in;
+//otherwise it returns NULL.
+//
+//static 
+void* LLMemory::tryToAlloc(void* address, U32 size)
+{
+#if LL_WINDOWS
+	address = VirtualAlloc(address, size, MEM_RESERVE | MEM_TOP_DOWN, PAGE_NOACCESS) ;
+	if(address)
+	{
+		if(!VirtualFree(address, 0, MEM_RELEASE))
+		{
+			llerrs << "error happens when free some memory reservation." << llendl ;
+		}
+	}
+	return address ;
+#else
+	return (void*)0x01 ; //skip checking
+#endif	
+}
+
+//static 
+void LLMemory::logMemoryInfo(BOOL update)
+{
+	if(update)
+	{
+		updateMemoryInfo() ;
+	}
+
+	llinfos << "Current allocated physical memory(KB): " << sAllocatedMemInKB << llendl ;
+	llinfos << "Current allocated page size (KB): " << sAllocatedPageSizeInKB << llendl ;
+	llinfos << "Current availabe physical memory(KB): " << sAvailPhysicalMemInKB << llendl ;
+	llinfos << "Current max usable memory(KB): " << sMaxPhysicalMemInKB << llendl ;
+}
+
+//return 0: everything is normal;
+//return 1: the memory pool is low, but not in danger;
+//return -1: the memory pool is in danger, is about to crash.
+//static 
+S32 LLMemory::isMemoryPoolLow()
+{
+	static const U32 LOW_MEMEOY_POOL_THRESHOLD_KB = 64 * 1024 ; //64 MB for emergency use
+
+	if(!sEnableMemoryFailurePrevention)
+	{
+		return 0 ; //no memory failure prevention.
+	}
+
+	if(sAvailPhysicalMemInKB < (LOW_MEMEOY_POOL_THRESHOLD_KB >> 2)) //out of physical memory
+	{
+		return -1 ;
+	}
+
+	if(sAllocatedPageSizeInKB + (LOW_MEMEOY_POOL_THRESHOLD_KB >> 2) > sMaxHeapSizeInKB) //out of virtual address space.
+	{
+		return -1 ;
+	}
+
+	return (S32)(sAvailPhysicalMemInKB < LOW_MEMEOY_POOL_THRESHOLD_KB || 
+		sAllocatedPageSizeInKB + LOW_MEMEOY_POOL_THRESHOLD_KB > sMaxHeapSizeInKB) ;
+}
+
+//static 
+U32 LLMemory::getAvailableMemKB() 
+{
+	return sAvailPhysicalMemInKB ;
+}
+
+//static 
+U32 LLMemory::getMaxMemKB() 
+{
+	return sMaxPhysicalMemInKB ;
+}
+
+//static 
+U32 LLMemory::getAllocatedMemKB() 
+{
+	return sAllocatedMemInKB ;
+}
+
+void* ll_allocate (size_t size)
+{
+	if (size == 0)
+	{
+		llwarns << "Null allocation" << llendl;
+	}
+	void *p = malloc(size);
+	if (p == NULL)
+	{
+		LLMemory::freeReserve();
+		llerrs << "Out of memory Error" << llendl;
+	}
+	return p;
+}
 
 //----------------------------------------------------------------------------
 
@@ -237,7 +392,7 @@ U64 LLMemory::getCurrentRSS()
 
 U32 LLMemory::getWorkingSetSize()
 {
-	return 0 ;
+	return 0;
 }
 
 #endif
@@ -258,7 +413,7 @@ LLMemTracker::LLMemTracker()
 	mDrawnIndex = 0 ;
 	mPaused = FALSE ;
 
-	mMutexp = new LLMutex(NULL) ;
+	mMutexp = new LLMutex() ;
 	mStringBuffer = new char*[128] ;
 	mStringBuffer[0] = new char[mCapacity * 128] ;
 	for(S32 i = 1 ; i < mCapacity ; i++)
@@ -376,3 +531,1661 @@ const char* LLMemTracker::getNextLine()
 #endif //MEM_TRACK_MEM
 //--------------------------------------------------------------------------------------------------
 
+
+//--------------------------------------------------------------------------------------------------
+//--------------------------------------------------------------------------------------------------
+//minimum slot size and minimal slot size interval
+const U32 ATOMIC_MEM_SLOT = 16 ; //bytes
+
+//minimum block sizes (page size) for small allocation, medium allocation, large allocation 
+const U32 MIN_BLOCK_SIZES[LLPrivateMemoryPool::SUPER_ALLOCATION] = {2 << 10, 4 << 10, 16 << 10} ; //
+
+//maximum block sizes for small allocation, medium allocation, large allocation 
+const U32 MAX_BLOCK_SIZES[LLPrivateMemoryPool::SUPER_ALLOCATION] = {64 << 10, 1 << 20, 4 << 20} ;
+
+//minimum slot sizes for small allocation, medium allocation, large allocation 
+const U32 MIN_SLOT_SIZES[LLPrivateMemoryPool::SUPER_ALLOCATION]  = {ATOMIC_MEM_SLOT, 2 << 10, 512 << 10};
+
+//maximum slot sizes for small allocation, medium allocation, large allocation 
+const U32 MAX_SLOT_SIZES[LLPrivateMemoryPool::SUPER_ALLOCATION]  = {(2 << 10) - ATOMIC_MEM_SLOT, (512 - 2) << 10, 4 << 20};
+
+//size of a block with multiple slots can not exceed CUT_OFF_SIZE
+const U32 CUT_OFF_SIZE = (64 << 10) ; //64 KB
+
+//max number of slots in a block
+const U32 MAX_NUM_SLOTS_IN_A_BLOCK = llmin(MIN_BLOCK_SIZES[0] / ATOMIC_MEM_SLOT, ATOMIC_MEM_SLOT * 8) ;
+
+//-------------------------------------------------------------
+//align val to be integer times of ATOMIC_MEM_SLOT
+U32 align(U32 val)
+{
+	U32 aligned = (val / ATOMIC_MEM_SLOT) * ATOMIC_MEM_SLOT ;
+	if(aligned < val)
+	{
+		aligned += ATOMIC_MEM_SLOT ;
+	}
+
+	return aligned ;
+}
+
+//-------------------------------------------------------------
+//class LLPrivateMemoryPool::LLMemoryBlock
+//-------------------------------------------------------------
+//
+//each memory block could fit for two page sizes: 0.75 * mSlotSize, which starts from the beginning of the memory chunk and grow towards the end of the
+//the block; another is mSlotSize, which starts from the end of the block and grows towards the beginning of the block.
+//
+LLPrivateMemoryPool::LLMemoryBlock::LLMemoryBlock()
+{
+	//empty
+}
+		
+LLPrivateMemoryPool::LLMemoryBlock::~LLMemoryBlock() 
+{
+	//empty
+}
+
+//create and initialize a memory block
+void LLPrivateMemoryPool::LLMemoryBlock::init(char* buffer, U32 buffer_size, U32 slot_size)
+{
+	mBuffer = buffer ;
+	mBufferSize = buffer_size ;
+	mSlotSize = slot_size ;
+	mTotalSlots = buffer_size / mSlotSize ;	
+	
+	llassert_always(buffer_size / mSlotSize <= MAX_NUM_SLOTS_IN_A_BLOCK) ; //max number is 128
+	
+	mAllocatedSlots = 0 ;
+	mDummySize = 0 ;
+
+	//init the bit map.
+	//mark free bits	
+	if(mTotalSlots > 32) //reserve extra space from mBuffer to store bitmap if needed.
+	{
+		mDummySize = ATOMIC_MEM_SLOT ;		
+		mTotalSlots -= (mDummySize + mSlotSize - 1) / mSlotSize ;
+		mUsageBits = 0 ;
+
+		S32 usage_bit_len = (mTotalSlots + 31) / 32 ;
+		
+		for(S32 i = 0 ; i < usage_bit_len - 1 ; i++)
+		{
+			*((U32*)mBuffer + i) = 0 ;
+		}
+		for(S32 i = usage_bit_len - 1 ; i < mDummySize / sizeof(U32) ; i++)
+		{
+			*((U32*)mBuffer + i) = 0xffffffff ;
+		}
+
+		if(mTotalSlots & 31)
+		{
+			*((U32*)mBuffer + usage_bit_len - 2) = (0xffffffff << (mTotalSlots & 31)) ;
+		}		
+	}	
+	else//no extra bitmap space reserved
+	{
+		mUsageBits = 0 ;
+		if(mTotalSlots & 31)
+		{
+			mUsageBits = (0xffffffff << (mTotalSlots & 31)) ;
+		}
+	}
+
+	mSelf = this ;
+	mNext = NULL ;
+	mPrev = NULL ;
+
+	llassert_always(mTotalSlots > 0) ;
+}
+
+//mark this block to be free with the memory [mBuffer, mBuffer + mBufferSize).
+void LLPrivateMemoryPool::LLMemoryBlock::setBuffer(char* buffer, U32 buffer_size)
+{
+	mBuffer = buffer ;
+	mBufferSize = buffer_size ;
+	mSelf = NULL ;
+	mTotalSlots = 0 ; //set the block is free.
+}
+
+//reserve a slot
+char* LLPrivateMemoryPool::LLMemoryBlock::allocate() 
+{
+	llassert_always(mAllocatedSlots < mTotalSlots) ;
+	
+	//find a free slot
+	U32* bits = NULL ;
+	U32  k = 0 ;
+	if(mUsageBits != 0xffffffff)
+	{
+		bits = &mUsageBits ;
+	}
+	else if(mDummySize > 0)//go to extra space
+	{		
+		for(S32 i = 0 ; i < mDummySize / sizeof(U32); i++)
+		{
+			if(*((U32*)mBuffer + i) != 0xffffffff)
+			{
+				bits = (U32*)mBuffer + i ;
+				k = i + 1 ;
+				break ;
+			}
+		}
+	}	
+	S32 idx = 0 ;
+	U32 tmp = *bits ;
+	for(; tmp & 1 ; tmp >>= 1, idx++) ;
+
+	//set the slot reserved
+	if(!idx)
+	{
+		*bits |= 1 ;
+	}
+	else
+	{
+		*bits |= (1 << idx) ;
+	}
+
+	mAllocatedSlots++ ;
+	
+	return mBuffer + mDummySize + (k * 32 + idx) * mSlotSize ;
+}
+
+//free a slot
+void  LLPrivateMemoryPool::LLMemoryBlock::freeMem(void* addr) 
+{
+	//bit index
+	U32 idx = ((U32)addr - (U32)mBuffer - mDummySize) / mSlotSize ;
+
+	U32* bits = &mUsageBits ;
+	if(idx >= 32)
+	{
+		bits = (U32*)mBuffer + (idx - 32) / 32 ;
+	}
+
+	//reset the bit
+	if(idx & 31)
+	{
+		*bits &= ~(1 << (idx & 31)) ;
+	}
+	else
+	{
+		*bits &= ~1 ;
+	}
+
+	mAllocatedSlots-- ;
+}
+
+//for debug use: reset the entire bitmap.
+void  LLPrivateMemoryPool::LLMemoryBlock::resetBitMap()
+{
+	for(S32 i = 0 ; i < mDummySize / sizeof(U32) ; i++)
+	{
+		*((U32*)mBuffer + i) = 0 ;
+	}
+	mUsageBits = 0 ;
+}
+//-------------------------------------------------------------------
+//class LLMemoryChunk
+//--------------------------------------------------------------------
+LLPrivateMemoryPool::LLMemoryChunk::LLMemoryChunk()
+{
+	//empty
+}
+
+LLPrivateMemoryPool::LLMemoryChunk::~LLMemoryChunk()
+{
+	//empty
+}
+
+//create and init a memory chunk
+void LLPrivateMemoryPool::LLMemoryChunk::init(char* buffer, U32 buffer_size, U32 min_slot_size, U32 max_slot_size, U32 min_block_size, U32 max_block_size) 
+{
+	mBuffer = buffer ;
+	mBufferSize = buffer_size ;
+	mAlloatedSize = 0 ;
+
+	mMetaBuffer = mBuffer + sizeof(LLMemoryChunk) ;
+
+	mMinBlockSize = min_block_size; //page size
+	mMinSlotSize = min_slot_size;
+	mMaxSlotSize = max_slot_size ;
+	mBlockLevels = mMaxSlotSize / mMinSlotSize ;
+	mPartitionLevels = max_block_size / mMinBlockSize + 1 ;
+
+	S32 max_num_blocks = (buffer_size - sizeof(LLMemoryChunk) - mBlockLevels * sizeof(LLMemoryBlock*) - mPartitionLevels * sizeof(LLMemoryBlock*)) / 
+		                 (mMinBlockSize + sizeof(LLMemoryBlock)) ;
+	//meta data space
+	mBlocks = (LLMemoryBlock*)mMetaBuffer ; //space reserved for all memory blocks.
+	mAvailBlockList = (LLMemoryBlock**)((char*)mBlocks + sizeof(LLMemoryBlock) * max_num_blocks) ; 
+	mFreeSpaceList = (LLMemoryBlock**)((char*)mAvailBlockList + sizeof(LLMemoryBlock*) * mBlockLevels) ; 
+	
+	//data buffer, which can be used for allocation
+	mDataBuffer = (char*)mFreeSpaceList + sizeof(LLMemoryBlock*) * mPartitionLevels ;
+	
+	//alignmnet
+	mDataBuffer = mBuffer + align(mDataBuffer - mBuffer) ;
+	
+	//init
+	for(U32 i = 0 ; i < mBlockLevels; i++)
+	{
+		mAvailBlockList[i] = NULL ;
+	}
+	for(U32 i = 0 ; i < mPartitionLevels ; i++)
+	{
+		mFreeSpaceList[i] = NULL ;
+	}
+
+	//assign the entire chunk to the first block
+	mBlocks[0].mPrev = NULL ;
+	mBlocks[0].mNext = NULL ;
+	mBlocks[0].setBuffer(mDataBuffer, buffer_size - (mDataBuffer - mBuffer)) ;
+	addToFreeSpace(&mBlocks[0]) ;
+
+	mNext = NULL ;
+	mPrev = NULL ;
+}
+
+//static 
+U32 LLPrivateMemoryPool::LLMemoryChunk::getMaxOverhead(U32 data_buffer_size, U32 min_slot_size, 
+													   U32 max_slot_size, U32 min_block_size, U32 max_block_size)
+{
+	//for large allocations, reserve some extra memory for meta data to avoid wasting much 
+	if(data_buffer_size / min_slot_size < 64) //large allocations
+	{
+		U32 overhead = sizeof(LLMemoryChunk) + (data_buffer_size / min_block_size) * sizeof(LLMemoryBlock) +
+			sizeof(LLMemoryBlock*) * (max_slot_size / min_slot_size) + sizeof(LLMemoryBlock*) * (max_block_size / min_block_size + 1) ;
+
+		//round to integer times of min_block_size
+		overhead = ((overhead + min_block_size - 1) / min_block_size) * min_block_size ;
+		return overhead ;
+	}
+	else
+	{
+		return 0 ; //do not reserve extra overhead if for small allocations
+	}
+}
+
+char* LLPrivateMemoryPool::LLMemoryChunk::allocate(U32 size)
+{
+	if(mMinSlotSize > size)
+	{
+		size = mMinSlotSize ;
+	}
+	if(mAlloatedSize + size  > mBufferSize - (mDataBuffer - mBuffer))
+	{
+		return NULL ; //no enough space in this chunk.
+	}
+
+	char* p = NULL ;
+	U32 blk_idx = getBlockLevel(size);
+
+	LLMemoryBlock* blk = NULL ;
+
+	//check if there is free block available
+	if(mAvailBlockList[blk_idx])
+	{
+		blk = mAvailBlockList[blk_idx] ;
+		p = blk->allocate() ;
+		
+		if(blk->isFull())
+		{
+			popAvailBlockList(blk_idx) ;
+		}
+	}
+
+	//ask for a new block
+	if(!p)
+	{
+		blk = addBlock(blk_idx) ;
+		if(blk)
+		{
+			p = blk->allocate() ;
+
+			if(blk->isFull())
+			{
+				popAvailBlockList(blk_idx) ;
+			}
+		}
+	}
+
+	//ask for space from larger blocks
+	if(!p)
+	{
+		for(S32 i = blk_idx + 1 ; i < mBlockLevels; i++)
+		{
+			if(mAvailBlockList[i])
+			{
+				blk = mAvailBlockList[i] ;
+				p = blk->allocate() ;
+
+				if(blk->isFull())
+				{
+					popAvailBlockList(i) ;
+				}
+				break ;
+			}
+		}
+	}
+
+	if(p && blk)
+	{		
+		mAlloatedSize += blk->getSlotSize() ;
+	}
+	return p ;
+}
+
+void LLPrivateMemoryPool::LLMemoryChunk::freeMem(void* addr)
+{	
+	U32 blk_idx = getPageIndex((U32)addr) ;
+	LLMemoryBlock* blk = (LLMemoryBlock*)(mMetaBuffer + blk_idx * sizeof(LLMemoryBlock)) ;
+	blk = blk->mSelf ;
+
+	bool was_full = blk->isFull() ;
+	blk->freeMem(addr) ;
+	mAlloatedSize -= blk->getSlotSize() ;
+
+	if(blk->empty())
+	{
+		removeBlock(blk) ;
+	}
+	else if(was_full)
+	{
+		addToAvailBlockList(blk) ;
+	}	
+}
+
+bool LLPrivateMemoryPool::LLMemoryChunk::empty()
+{
+	return !mAlloatedSize ;
+}
+
+bool LLPrivateMemoryPool::LLMemoryChunk::containsAddress(const char* addr) const
+{
+	return (U32)mBuffer <= (U32)addr && (U32)mBuffer + mBufferSize > (U32)addr ;
+}
+
+//debug use
+void LLPrivateMemoryPool::LLMemoryChunk::dump()
+{
+#if 0
+	//sanity check
+	//for(S32 i = 0 ; i < mBlockLevels ; i++)
+	//{
+	//	LLMemoryBlock* blk = mAvailBlockList[i] ;
+	//	while(blk)
+	//	{
+	//		blk_list.push_back(blk) ;
+	//		blk = blk->mNext ;
+	//	}
+	//}
+	for(S32 i = 0 ; i < mPartitionLevels ; i++)
+	{
+		LLMemoryBlock* blk = mFreeSpaceList[i] ;
+		while(blk)
+		{
+			blk_list.push_back(blk) ;
+			blk = blk->mNext ;
+		}
+	}
+
+	std::sort(blk_list.begin(), blk_list.end(), LLMemoryBlock::CompareAddress());
+
+	U32 total_size = blk_list[0]->getBufferSize() ;
+	for(U32 i = 1 ; i < blk_list.size(); i++)
+	{
+		total_size += blk_list[i]->getBufferSize() ;
+		if((U32)blk_list[i]->getBuffer() < (U32)blk_list[i-1]->getBuffer() + blk_list[i-1]->getBufferSize())
+		{
+			llerrs << "buffer corrupted." << llendl ;
+		}
+	}
+
+	llassert_always(total_size + mMinBlockSize >= mBufferSize - ((U32)mDataBuffer - (U32)mBuffer)) ;
+
+	U32 blk_num = (mBufferSize - (mDataBuffer - mBuffer)) / mMinBlockSize ;
+	for(U32 i = 0 ; i < blk_num ; )
+	{
+		LLMemoryBlock* blk = &mBlocks[i] ;
+		if(blk->mSelf)
+		{
+			U32 end = blk->getBufferSize() / mMinBlockSize ;
+			for(U32 j = 0 ; j < end ; j++)
+			{
+				llassert_always(blk->mSelf == blk || !blk->mSelf) ;
+			}
+			i += end ;
+		}
+		else
+		{
+			llerrs << "gap happens" << llendl ;
+		}
+	}
+#endif
+#if 0
+	llinfos << "---------------------------" << llendl ;
+	llinfos << "Chunk buffer: " << (U32)getBuffer() << " size: " << getBufferSize() << llendl ;
+
+	llinfos << "available blocks ... " << llendl ;
+	for(S32 i = 0 ; i < mBlockLevels ; i++)
+	{
+		LLMemoryBlock* blk = mAvailBlockList[i] ;
+		while(blk)
+		{
+			llinfos << "blk buffer " << (U32)blk->getBuffer() << " size: " << blk->getBufferSize() << llendl ;
+			blk = blk->mNext ;
+		}
+	}
+
+	llinfos << "free blocks ... " << llendl ;
+	for(S32 i = 0 ; i < mPartitionLevels ; i++)
+	{
+		LLMemoryBlock* blk = mFreeSpaceList[i] ;
+		while(blk)
+		{
+			llinfos << "blk buffer " << (U32)blk->getBuffer() << " size: " << blk->getBufferSize() << llendl ;
+			blk = blk->mNext ;
+		}
+	}
+#endif
+}
+
+//compute the size for a block, the size is round to integer times of mMinBlockSize.
+U32 LLPrivateMemoryPool::LLMemoryChunk::calcBlockSize(U32 slot_size)
+{
+	//
+	//Note: we try to make a block to have 32 slots if the size is not over 32 pages
+	//32 is the number of bits of an integer in a 32-bit system
+	//
+
+	U32 block_size;
+	U32 cut_off_size = llmin(CUT_OFF_SIZE, (U32)(mMinBlockSize << 5)) ;
+
+	if((slot_size << 5) <= mMinBlockSize)//for small allocations, return one page 
+	{
+		block_size = mMinBlockSize ;
+	}
+	else if(slot_size >= cut_off_size)//for large allocations, return one-slot block
+	{
+		block_size = (slot_size / mMinBlockSize) * mMinBlockSize ;
+		if(block_size < slot_size)
+		{
+			block_size += mMinBlockSize ;
+		}
+	}
+	else //medium allocations
+	{
+		if((slot_size << 5) >= cut_off_size)
+		{
+			block_size = cut_off_size ;
+		}
+		else
+		{
+			block_size = ((slot_size << 5) / mMinBlockSize) * mMinBlockSize ;
+		}
+	}
+
+	llassert_always(block_size >= slot_size) ;
+
+	return block_size ;
+}
+
+//create a new block in the chunk
+LLPrivateMemoryPool::LLMemoryBlock* LLPrivateMemoryPool::LLMemoryChunk::addBlock(U32 blk_idx)
+{	
+	U32 slot_size = mMinSlotSize * (blk_idx + 1) ;
+	U32 preferred_block_size = calcBlockSize(slot_size) ;	
+	U16 idx = getPageLevel(preferred_block_size); 
+	LLMemoryBlock* blk = NULL ;
+	
+	if(mFreeSpaceList[idx])//if there is free slot for blk_idx
+	{
+		blk = createNewBlock(mFreeSpaceList[idx], preferred_block_size, slot_size, blk_idx) ;
+	}
+	else if(mFreeSpaceList[mPartitionLevels - 1]) //search free pool
+	{		
+		blk = createNewBlock(mFreeSpaceList[mPartitionLevels - 1], preferred_block_size, slot_size, blk_idx) ;
+	}
+	else //search for other non-preferred but enough space slot.
+	{
+		S32 min_idx = 0 ;
+		if(slot_size > mMinBlockSize)
+		{
+			min_idx = getPageLevel(slot_size) ;
+		}
+		for(S32 i = (S32)idx - 1 ; i >= min_idx ; i--) //search the small slots first
+		{
+			if(mFreeSpaceList[i])
+			{
+				U32 new_preferred_block_size = mFreeSpaceList[i]->getBufferSize();
+				new_preferred_block_size = (new_preferred_block_size / mMinBlockSize) * mMinBlockSize ; //round to integer times of mMinBlockSize.
+
+				//create a NEW BLOCK THERE.
+				if(new_preferred_block_size >= slot_size) //at least there is space for one slot.
+				{
+					
+					blk = createNewBlock(mFreeSpaceList[i], new_preferred_block_size, slot_size, blk_idx) ;
+				}
+				break ;
+			} 
+		}
+
+		if(!blk)
+		{
+			for(U16 i = idx + 1 ; i < mPartitionLevels - 1; i++) //search the large slots 
+			{
+				if(mFreeSpaceList[i])
+				{
+					//create a NEW BLOCK THERE.
+					blk = createNewBlock(mFreeSpaceList[i], preferred_block_size, slot_size, blk_idx) ;
+					break ;
+				} 
+			}
+		}
+	}
+
+	return blk ;
+}
+
+//create a new block at the designed location
+LLPrivateMemoryPool::LLMemoryBlock* LLPrivateMemoryPool::LLMemoryChunk::createNewBlock(LLMemoryBlock* blk, U32 buffer_size, U32 slot_size, U32 blk_idx)
+{
+	//unlink from the free space
+	removeFromFreeSpace(blk) ;
+
+	//check the rest space
+	U32 new_free_blk_size = blk->getBufferSize() - buffer_size ;	
+	if(new_free_blk_size < mMinBlockSize) //can not partition the memory into size smaller than mMinBlockSize
+	{
+		new_free_blk_size = 0 ; //discard the last small extra space.
+	}			
+
+	//add the rest space back to the free list
+	if(new_free_blk_size > 0) //blk still has free space
+	{
+		LLMemoryBlock* next_blk = blk + (buffer_size / mMinBlockSize) ;
+		next_blk->mPrev = NULL ;
+		next_blk->mNext = NULL ;
+		next_blk->setBuffer(blk->getBuffer() + buffer_size, new_free_blk_size) ;
+		addToFreeSpace(next_blk) ;
+	}
+
+	blk->init(blk->getBuffer(), buffer_size, slot_size) ;
+	//insert to the available block list...
+	mAvailBlockList[blk_idx] = blk ;
+
+	//mark the address map: all blocks covered by this block space pointing back to this block.
+	U32 end = (buffer_size / mMinBlockSize) ;
+	for(U32 i = 1 ; i < end ; i++)
+	{
+		(blk + i)->mSelf = blk ;
+	}
+
+	return blk ;
+}
+
+//delete a block, release the block to the free pool.
+void LLPrivateMemoryPool::LLMemoryChunk::removeBlock(LLMemoryBlock* blk)
+{
+	//remove from the available block list
+	if(blk->mPrev)
+	{
+		blk->mPrev->mNext = blk->mNext ;
+	}
+	if(blk->mNext)
+	{
+		blk->mNext->mPrev = blk->mPrev ;
+	}
+	U32 blk_idx = getBlockLevel(blk->getSlotSize());
+	if(mAvailBlockList[blk_idx] == blk)
+	{
+		mAvailBlockList[blk_idx] = blk->mNext ;
+	}
+
+	blk->mNext = NULL ;
+	blk->mPrev = NULL ;
+	
+	//mark it free
+	blk->setBuffer(blk->getBuffer(), blk->getBufferSize()) ;
+
+#if 1
+	//merge blk with neighbors if possible
+	if(blk->getBuffer() > mDataBuffer) //has the left neighbor
+	{
+		if((blk - 1)->mSelf->isFree())
+		{
+			LLMemoryBlock* left_blk = (blk - 1)->mSelf ;
+			removeFromFreeSpace((blk - 1)->mSelf);
+			left_blk->setBuffer(left_blk->getBuffer(), left_blk->getBufferSize() + blk->getBufferSize()) ;
+			blk = left_blk ;
+		}
+	}
+	if(blk->getBuffer() + blk->getBufferSize() <= mBuffer + mBufferSize - mMinBlockSize) //has the right neighbor
+	{
+		U32 d = blk->getBufferSize() / mMinBlockSize ;
+		if((blk + d)->isFree())
+		{
+			LLMemoryBlock* right_blk = blk + d ;
+			removeFromFreeSpace(blk + d) ;
+			blk->setBuffer(blk->getBuffer(), blk->getBufferSize() + right_blk->getBufferSize()) ;
+		}
+	}
+#endif
+	
+	addToFreeSpace(blk) ;
+
+	return ;
+}
+
+//the top block in the list is full, pop it out of the list
+void LLPrivateMemoryPool::LLMemoryChunk::popAvailBlockList(U32 blk_idx) 
+{
+	if(mAvailBlockList[blk_idx])
+	{
+		LLMemoryBlock* next = mAvailBlockList[blk_idx]->mNext ;
+		if(next)
+		{
+			next->mPrev = NULL ;
+		}
+		mAvailBlockList[blk_idx]->mPrev = NULL ;
+		mAvailBlockList[blk_idx]->mNext = NULL ;
+		mAvailBlockList[blk_idx] = next ;
+	}
+}
+
+//add the block back to the free pool
+void LLPrivateMemoryPool::LLMemoryChunk::addToFreeSpace(LLMemoryBlock* blk) 
+{
+	llassert_always(!blk->mPrev) ;
+	llassert_always(!blk->mNext) ;
+
+	U16 free_idx = blk->getBufferSize() / mMinBlockSize - 1;
+
+	(blk + free_idx)->mSelf = blk ; //mark the end pointing back to the head.
+	free_idx = llmin(free_idx, (U16)(mPartitionLevels - 1)) ;
+
+	blk->mNext = mFreeSpaceList[free_idx] ;
+	if(mFreeSpaceList[free_idx])
+	{
+		mFreeSpaceList[free_idx]->mPrev = blk ;
+	}
+	mFreeSpaceList[free_idx] = blk ;
+	blk->mPrev = NULL ;
+	blk->mSelf = blk ;
+	
+	return ;
+}
+
+//remove the space from the free pool
+void LLPrivateMemoryPool::LLMemoryChunk::removeFromFreeSpace(LLMemoryBlock* blk) 
+{
+	U16 free_idx = blk->getBufferSize() / mMinBlockSize - 1;
+	free_idx = llmin(free_idx, (U16)(mPartitionLevels - 1)) ;
+
+	if(mFreeSpaceList[free_idx] == blk)
+	{
+		mFreeSpaceList[free_idx] = blk->mNext ;
+	}
+	if(blk->mPrev)
+	{
+		blk->mPrev->mNext = blk->mNext ;
+	}
+	if(blk->mNext)
+	{
+		blk->mNext->mPrev = blk->mPrev ;
+	}
+	blk->mNext = NULL ;
+	blk->mPrev = NULL ;
+	blk->mSelf = NULL ;
+
+	return ;
+}
+
+void LLPrivateMemoryPool::LLMemoryChunk::addToAvailBlockList(LLMemoryBlock* blk) 
+{
+	llassert_always(!blk->mPrev) ;
+	llassert_always(!blk->mNext) ;
+
+	U32 blk_idx = getBlockLevel(blk->getSlotSize());
+
+	blk->mNext = mAvailBlockList[blk_idx] ;
+	if(blk->mNext)
+	{
+		blk->mNext->mPrev = blk ;
+	}
+	blk->mPrev = NULL ;
+	mAvailBlockList[blk_idx] = blk ;
+
+	return ;
+}
+
+U32 LLPrivateMemoryPool::LLMemoryChunk::getPageIndex(U32 addr)
+{
+	return (addr - (U32)mDataBuffer) / mMinBlockSize ;
+}
+
+//for mAvailBlockList
+U32 LLPrivateMemoryPool::LLMemoryChunk::getBlockLevel(U32 size)
+{
+	llassert(size >= mMinSlotSize && size <= mMaxSlotSize) ;
+
+	//start from 0
+	return (size + mMinSlotSize - 1) / mMinSlotSize - 1 ;
+}
+
+//for mFreeSpaceList
+U16 LLPrivateMemoryPool::LLMemoryChunk::getPageLevel(U32 size)
+{
+	//start from 0
+	U16 level = size / mMinBlockSize - 1 ;
+	if(level >= mPartitionLevels)
+	{
+		level = mPartitionLevels - 1 ;
+	}
+	return level ;
+}
+
+//-------------------------------------------------------------------
+//class LLPrivateMemoryPool
+//--------------------------------------------------------------------
+const U32 CHUNK_SIZE = 4 << 20 ; //4 MB
+const U32 LARGE_CHUNK_SIZE = 4 * CHUNK_SIZE ; //16 MB
+LLPrivateMemoryPool::LLPrivateMemoryPool(S32 type) :
+	mMutexp(NULL),	
+	mReservedPoolSize(0),
+	mHashFactor(1),
+	mType(type)
+{
+	const U32 MAX_POOL_SIZE = 256 * 1024 * 1024 ; //256 MB
+
+	mMaxPoolSize = MAX_POOL_SIZE ;
+	if(type == STATIC_THREADED || type == VOLATILE_THREADED)
+	{
+		mMutexp = new LLMutex ;
+	}
+
+	for(S32 i = 0 ; i < SUPER_ALLOCATION ; i++)
+	{
+		mChunkList[i] = NULL ;
+	}	
+	
+	mNumOfChunks = 0 ;
+}
+
+LLPrivateMemoryPool::~LLPrivateMemoryPool()
+{
+	destroyPool();
+	delete mMutexp ;
+}
+
+char* LLPrivateMemoryPool::allocate(U32 size)
+{	
+	if(!size)
+	{
+		return NULL ;
+	}
+
+	//if the asked size larger than MAX_BLOCK_SIZE, fetch from heap directly, the pool does not manage it
+	if(size >= CHUNK_SIZE)
+	{
+		return (char*)malloc(size) ;
+	}
+
+	char* p = NULL ;
+
+	//find the appropriate chunk
+	S32 chunk_idx = getChunkIndex(size) ;
+	
+	lock() ;
+
+	LLMemoryChunk* chunk = mChunkList[chunk_idx];
+	while(chunk)
+	{
+		if((p = chunk->allocate(size)))
+		{
+			break ;
+		}
+		chunk = chunk->mNext ;
+	}
+	
+	//fetch new memory chunk
+	if(!p)
+	{
+		if(mReservedPoolSize + CHUNK_SIZE > mMaxPoolSize)
+		{
+			chunk = mChunkList[chunk_idx];
+			while(chunk)
+			{
+				if((p = chunk->allocate(size)))
+				{
+					break ;
+				}
+				chunk = chunk->mNext ;
+			}
+		}
+
+		chunk = addChunk(chunk_idx) ;
+		if(chunk)
+		{
+			p = chunk->allocate(size) ;
+		}
+	}
+
+	unlock() ;
+
+	return p ;
+}
+
+void LLPrivateMemoryPool::freeMem(void* addr)
+{
+	if(!addr)
+	{
+		return ;
+	}
+	
+	lock() ;
+	
+	LLMemoryChunk* chunk = findChunk((char*)addr) ;
+	
+	if(!chunk)
+	{
+		free(addr) ; //release from heap
+	}
+	else
+	{
+		chunk->freeMem(addr) ;
+
+		if(chunk->empty())
+		{
+			removeChunk(chunk) ;
+		}
+	}
+	
+	unlock() ;
+}
+
+void LLPrivateMemoryPool::dump()
+{
+}
+
+U32 LLPrivateMemoryPool::getTotalAllocatedSize()
+{
+	U32 total_allocated = 0 ;
+
+	LLMemoryChunk* chunk ;
+	for(S32 i = 0 ; i < SUPER_ALLOCATION ; i++)
+	{
+		chunk = mChunkList[i];
+		while(chunk)
+		{
+			total_allocated += chunk->getAllocatedSize() ;
+			chunk = chunk->mNext ;
+		}
+	}
+
+	return total_allocated ;
+}
+
+void LLPrivateMemoryPool::lock()
+{
+	if(mMutexp)
+	{
+		mMutexp->lock() ;
+	}
+}
+
+void LLPrivateMemoryPool::unlock()
+{
+	if(mMutexp)
+	{
+		mMutexp->unlock() ;
+	}
+}
+
+S32  LLPrivateMemoryPool::getChunkIndex(U32 size) 
+{
+	S32 i ;
+	for(i = 0 ; size > MAX_SLOT_SIZES[i]; i++);
+	
+	llassert_always(i < SUPER_ALLOCATION);
+
+	return i ;
+}
+
+//destroy the entire pool
+void  LLPrivateMemoryPool::destroyPool()
+{
+	lock() ;
+
+	if(mNumOfChunks > 0)
+	{
+		llwarns << "There is some memory not freed when destroy the memory pool!" << llendl ;
+	}
+
+	mNumOfChunks = 0 ;
+	mChunkHashList.clear() ;
+	mHashFactor = 1 ;
+	for(S32 i = 0 ; i < SUPER_ALLOCATION ; i++)
+	{
+		mChunkList[i] = NULL ;
+	}
+
+	unlock() ;
+}
+
+void  LLPrivateMemoryPool::checkSize(U32 asked_size)
+{
+	if(mReservedPoolSize + asked_size > mMaxPoolSize)
+	{
+		llinfos << "Max pool size: " << mMaxPoolSize << llendl ;
+		llinfos << "Total reserved size: " << mReservedPoolSize + asked_size << llendl ;
+		llinfos << "Total_allocated Size: " << getTotalAllocatedSize() << llendl ;
+
+		llerrs << "The pool is overflowing..." << llendl ;
+	}
+}
+
+LLPrivateMemoryPool::LLMemoryChunk* LLPrivateMemoryPool::addChunk(S32 chunk_index)
+{
+	U32 preferred_size ;
+	U32 overhead ;
+	if(chunk_index < LARGE_ALLOCATION)
+	{
+		preferred_size = CHUNK_SIZE ; //4MB
+		overhead = LLMemoryChunk::getMaxOverhead(preferred_size, MIN_SLOT_SIZES[chunk_index],
+			MAX_SLOT_SIZES[chunk_index], MIN_BLOCK_SIZES[chunk_index], MAX_BLOCK_SIZES[chunk_index]) ;
+	}
+	else
+	{
+		preferred_size = LARGE_CHUNK_SIZE ; //16MB
+		overhead = LLMemoryChunk::getMaxOverhead(preferred_size, MIN_SLOT_SIZES[chunk_index], 
+			MAX_SLOT_SIZES[chunk_index], MIN_BLOCK_SIZES[chunk_index], MAX_BLOCK_SIZES[chunk_index]) ;
+	}
+
+	checkSize(preferred_size + overhead) ;
+	mReservedPoolSize += preferred_size + overhead ;
+
+	char* buffer = (char*)malloc(preferred_size + overhead) ;
+	if(!buffer)
+	{
+		return NULL ;
+	}
+	
+	LLMemoryChunk* chunk = new (buffer) LLMemoryChunk() ;
+	chunk->init(buffer, preferred_size + overhead, MIN_SLOT_SIZES[chunk_index],
+		MAX_SLOT_SIZES[chunk_index], MIN_BLOCK_SIZES[chunk_index], MAX_BLOCK_SIZES[chunk_index]) ;
+
+	//add to the tail of the linked list
+	{
+		if(!mChunkList[chunk_index])
+		{
+			mChunkList[chunk_index] = chunk ;
+		}
+		else
+		{
+			LLMemoryChunk* cur = mChunkList[chunk_index] ;
+			while(cur->mNext)
+			{
+				cur = cur->mNext ;
+			}
+			cur->mNext = chunk ;
+			chunk->mPrev = cur ;
+		}
+	}
+
+	//insert into the hash table
+	addToHashTable(chunk) ;
+	
+	mNumOfChunks++;
+
+	return chunk ;
+}
+
+void LLPrivateMemoryPool::removeChunk(LLMemoryChunk* chunk) 
+{
+	if(!chunk)
+	{
+		return ;
+	}
+
+	//remove from the linked list
+	for(S32 i = 0 ; i < SUPER_ALLOCATION ; i++)
+	{
+		if(mChunkList[i] == chunk)
+		{
+			mChunkList[i] = chunk->mNext ;
+		}
+	}
+
+	if(chunk->mPrev)
+	{
+		chunk->mPrev->mNext = chunk->mNext ;
+	}
+	if(chunk->mNext)
+	{
+		chunk->mNext->mPrev = chunk->mPrev ;
+	}
+
+	//remove from the hash table
+	removeFromHashTable(chunk) ;
+	
+	mNumOfChunks--;
+	mReservedPoolSize -= chunk->getBufferSize() ;
+	
+	//release memory
+	free(chunk->getBuffer()) ;
+}
+
+U16 LLPrivateMemoryPool::findHashKey(const char* addr)
+{
+	return (((U32)addr) / CHUNK_SIZE) % mHashFactor ;
+}
+
+LLPrivateMemoryPool::LLMemoryChunk* LLPrivateMemoryPool::findChunk(const char* addr)
+{
+	U16 key = findHashKey(addr) ;	
+	if(mChunkHashList.size() <= key)
+	{
+		return NULL ;
+	}
+
+	return mChunkHashList[key].findChunk(addr) ;	
+}
+
+void LLPrivateMemoryPool::addToHashTable(LLMemoryChunk* chunk) 
+{
+	static const U16 HASH_FACTORS[] = {41, 83, 193, 317, 419, 523, 0xFFFF}; 
+	
+	U16 i ;
+	if(mChunkHashList.empty())
+	{
+		mHashFactor = HASH_FACTORS[0] ;
+		rehash() ;		
+	}
+
+	U16 start_key = findHashKey(chunk->getBuffer()) ;
+	U16 end_key = findHashKey(chunk->getBuffer() + chunk->getBufferSize() - 1) ;
+	bool need_rehash = false ;
+	
+	if(mChunkHashList[start_key].hasElement(chunk))
+	{
+		return; //already inserted.
+	}
+	need_rehash = mChunkHashList[start_key].add(chunk) ;
+	
+	if(start_key == end_key && !need_rehash)
+	{
+		return ; //done
+	}
+
+	if(!need_rehash)
+	{
+		need_rehash = mChunkHashList[end_key].add(chunk) ;
+	}
+
+	if(!need_rehash)
+	{
+		if(end_key < start_key)
+		{
+			need_rehash = fillHashTable(start_key + 1, mHashFactor, chunk) ;
+			if(!need_rehash)
+			{
+				need_rehash = fillHashTable(0, end_key, chunk) ;
+			}
+		}
+		else
+		{
+			need_rehash = fillHashTable(start_key + 1, end_key, chunk) ;
+		}
+	}
+	
+	if(need_rehash)
+	{
+		i = 0 ;
+		while(HASH_FACTORS[i] <= mHashFactor) i++;
+
+		mHashFactor = HASH_FACTORS[i] ;
+		llassert_always(mHashFactor != 0xFFFF) ;//stop point to prevent endlessly recursive calls
+
+		rehash() ;
+	}
+}
+
+void LLPrivateMemoryPool::removeFromHashTable(LLMemoryChunk* chunk) 
+{
+	U16 start_key = findHashKey(chunk->getBuffer()) ;
+	U16 end_key = findHashKey(chunk->getBuffer() + chunk->getBufferSize() - 1) ;
+	
+	mChunkHashList[start_key].remove(chunk) ;
+	if(start_key == end_key)
+	{
+		return ; //done
+	}
+
+	mChunkHashList[end_key].remove(chunk) ;
+	
+	if(end_key < start_key)
+	{
+		for(U16 i = start_key + 1 ; i < mHashFactor; i++)
+		{
+			mChunkHashList[i].remove(chunk) ;
+		}
+		for(U16 i = 0 ; i < end_key; i++)
+		{
+			mChunkHashList[i].remove(chunk) ;
+		}
+	}
+	else
+	{
+		for(U16 i = start_key + 1 ; i < end_key; i++)
+		{
+			mChunkHashList[i].remove(chunk) ;
+		}
+	}
+}
+
+void LLPrivateMemoryPool::rehash()
+{
+	llinfos << "new hash factor: " << mHashFactor << llendl ;
+
+	mChunkHashList.clear() ;
+	mChunkHashList.resize(mHashFactor) ;
+
+	LLMemoryChunk* chunk ;
+	for(U16 i = 0 ; i < SUPER_ALLOCATION ; i++)
+	{
+		chunk = mChunkList[i] ; 
+		while(chunk)
+		{
+			addToHashTable(chunk) ;
+			chunk = chunk->mNext ;
+		}
+	}
+}
+
+bool LLPrivateMemoryPool::fillHashTable(U16 start, U16 end, LLMemoryChunk* chunk)
+{
+	for(U16 i = start; i < end; i++)
+	{
+		if(mChunkHashList[i].add(chunk))
+		{			
+			return true ;
+		}		
+	}
+
+	return false ;
+}
+
+//--------------------------------------------------------------------
+// class LLChunkHashElement
+//--------------------------------------------------------------------
+LLPrivateMemoryPool::LLMemoryChunk* LLPrivateMemoryPool::LLChunkHashElement::findChunk(const char* addr)
+{
+	if(mFirst && mFirst->containsAddress(addr))
+	{
+		return mFirst ;
+	}
+	else if(mSecond && mSecond->containsAddress(addr))
+	{
+		return mSecond ;
+	}
+
+	return NULL ;
+}
+
+//return false if successfully inserted to the hash slot.
+bool LLPrivateMemoryPool::LLChunkHashElement::add(LLPrivateMemoryPool::LLMemoryChunk* chunk)
+{
+	llassert_always(!hasElement(chunk)) ;
+
+	if(!mFirst)
+	{
+		mFirst = chunk ;
+	}
+	else if(!mSecond)
+	{
+		mSecond = chunk ;
+	}
+	else
+	{
+		return true ; //failed
+	}
+
+	return false ;
+}
+
+void LLPrivateMemoryPool::LLChunkHashElement::remove(LLPrivateMemoryPool::LLMemoryChunk* chunk)
+{
+	if(mFirst == chunk)
+	{
+		mFirst = NULL ;
+	}
+	else if(mSecond ==chunk)
+	{
+		mSecond = NULL ;
+	}
+	else
+	{
+		llerrs << "This slot does not contain this chunk!" << llendl ;
+	}
+}
+
+//--------------------------------------------------------------------
+//class LLPrivateMemoryPoolManager
+//--------------------------------------------------------------------
+LLPrivateMemoryPoolManager* LLPrivateMemoryPoolManager::sInstance = NULL ;
+
+LLPrivateMemoryPoolManager::LLPrivateMemoryPoolManager(BOOL enabled) 
+{
+	mPoolList.resize(LLPrivateMemoryPool::MAX_TYPES) ;
+
+	for(S32 i = 0 ; i < LLPrivateMemoryPool::MAX_TYPES; i++)
+	{
+		mPoolList[i] = NULL ;
+	}
+
+	mPrivatePoolEnabled = enabled ;
+}
+
+LLPrivateMemoryPoolManager::~LLPrivateMemoryPoolManager() 
+{
+
+#if __DEBUG_PRIVATE_MEM__
+	if(!sMemAllocationTracker.empty())
+	{
+		llwarns << "there is potential memory leaking here. The list of not freed memory blocks are from: " <<llendl ;
+
+		S32 k = 0 ;
+		for(mem_allocation_info_t::iterator iter = sMemAllocationTracker.begin() ; iter != sMemAllocationTracker.end() ; ++iter)
+		{
+			llinfos << k++ << ", " << iter->second << llendl ;
+		}
+		sMemAllocationTracker.clear() ;
+	}
+#endif
+
+#if 0
+	//all private pools should be released by their owners before reaching here.
+	for(S32 i = 0 ; i < LLPrivateMemoryPool::MAX_TYPES; i++)
+	{
+		llassert_always(!mPoolList[i]) ;
+	}
+	mPoolList.clear() ;
+
+#else
+	//forcefully release all memory
+	for(S32 i = 0 ; i < LLPrivateMemoryPool::MAX_TYPES; i++)
+	{
+		if(mPoolList[i])
+		{
+			delete mPoolList[i] ;
+			mPoolList[i] = NULL ;
+		}
+	}
+	mPoolList.clear() ;
+#endif
+}
+
+//static 
+void LLPrivateMemoryPoolManager::initClass(BOOL enabled) 
+{
+	llassert_always(!sInstance) ;
+
+	sInstance = new LLPrivateMemoryPoolManager(enabled) ;
+}
+
+//static 
+LLPrivateMemoryPoolManager* LLPrivateMemoryPoolManager::getInstance() 
+{
+	//if(!sInstance)
+	//{
+	//	sInstance = new LLPrivateMemoryPoolManager(FALSE) ;
+	//}
+	return sInstance ;
+}
+	
+//static 
+void LLPrivateMemoryPoolManager::destroyClass() 
+{
+	if(sInstance)
+	{
+		delete sInstance ;
+		sInstance = NULL ;
+	}
+}
+
+LLPrivateMemoryPool* LLPrivateMemoryPoolManager::newPool(S32 type) 
+{
+	if(!mPrivatePoolEnabled)
+	{
+		return NULL ;
+	}
+
+	if(!mPoolList[type])
+	{
+		mPoolList[type] = new LLPrivateMemoryPool(type) ;
+	}
+
+	return mPoolList[type] ;
+}
+
+void LLPrivateMemoryPoolManager::deletePool(LLPrivateMemoryPool* pool) 
+{
+	if(pool && pool->isEmpty())
+	{
+		mPoolList[pool->getType()] = NULL ;
+		delete pool;
+	}
+}
+
+//debug
+void LLPrivateMemoryPoolManager::updateStatistics()
+{
+	mTotalReservedSize = 0 ;
+	mTotalAllocatedSize = 0 ;
+
+	for(U32 i = 0; i < mPoolList.size(); i++)
+	{
+		if(mPoolList[i])
+		{
+			mTotalReservedSize += mPoolList[i]->getTotalReservedSize() ;
+			mTotalAllocatedSize += mPoolList[i]->getTotalAllocatedSize() ;
+		}
+	}
+}
+
+#if __DEBUG_PRIVATE_MEM__
+//static 
+char* LLPrivateMemoryPoolManager::allocate(LLPrivateMemoryPool* poolp, U32 size, const char* function, const int line) 
+{
+	char* p ;
+
+	if(!poolp)
+	{
+		p = (char*)malloc(size) ;
+	}
+	else
+	{
+		p = poolp->allocate(size) ;
+	}
+	
+	if(p)
+	{
+		char num[16] ;
+		sprintf(num, " line: %d ", line) ;
+		std::string str(function) ;
+		str += num; 
+
+		sMemAllocationTracker[p] = str ;
+	}
+
+	return p ;
+}	
+#else
+//static 
+char* LLPrivateMemoryPoolManager::allocate(LLPrivateMemoryPool* poolp, U32 size) 
+{
+	if(poolp)
+	{
+		return poolp->allocate(size) ;		
+	}
+	else
+	{
+		return (char*)malloc(size) ;
+	}
+}
+#endif
+
+//static 
+void  LLPrivateMemoryPoolManager::freeMem(LLPrivateMemoryPool* poolp, void* addr) 
+{
+	if(!addr)
+	{
+		return ;
+	}
+
+#if __DEBUG_PRIVATE_MEM__
+	sMemAllocationTracker.erase((char*)addr) ;
+#endif
+
+	if(poolp)
+	{
+		poolp->freeMem(addr) ;
+	}
+	else
+	{
+		free(addr) ;
+	}	
+}
+
+//--------------------------------------------------------------------
+//class LLPrivateMemoryPoolTester
+//--------------------------------------------------------------------
+#if 0
+LLPrivateMemoryPoolTester* LLPrivateMemoryPoolTester::sInstance = NULL ;
+LLPrivateMemoryPool* LLPrivateMemoryPoolTester::sPool = NULL ;
+LLPrivateMemoryPoolTester::LLPrivateMemoryPoolTester()
+{	
+}
+	
+LLPrivateMemoryPoolTester::~LLPrivateMemoryPoolTester() 
+{	
+}
+
+//static 
+LLPrivateMemoryPoolTester* LLPrivateMemoryPoolTester::getInstance() 
+{
+	if(!sInstance)
+	{
+		sInstance = ::new LLPrivateMemoryPoolTester() ;
+	}
+	return sInstance ;
+}
+
+//static 
+void LLPrivateMemoryPoolTester::destroy()
+{
+	if(sInstance)
+	{
+		::delete sInstance ;
+		sInstance = NULL ;
+	}
+
+	if(sPool)
+	{
+		LLPrivateMemoryPoolManager::getInstance()->deletePool(sPool) ;
+		sPool = NULL ;
+	}
+}
+
+void LLPrivateMemoryPoolTester::run(S32 type) 
+{
+	if(sPool)
+	{
+		LLPrivateMemoryPoolManager::getInstance()->deletePool(sPool) ;
+	}
+	sPool = LLPrivateMemoryPoolManager::getInstance()->newPool(type) ;
+
+	//run the test
+	correctnessTest() ;
+	performanceTest() ;
+	//fragmentationtest() ;
+
+	//release pool.
+	LLPrivateMemoryPoolManager::getInstance()->deletePool(sPool) ;
+	sPool = NULL ;
+}
+
+void LLPrivateMemoryPoolTester::test(U32 min_size, U32 max_size, U32 stride, U32 times, 
+									 bool random_deletion, bool output_statistics)
+{
+	U32 levels = (max_size - min_size) / stride + 1 ;
+	char*** p ;
+	U32 i, j ;
+	U32 total_allocated_size = 0 ;
+
+	//allocate space for p ;
+	if(!(p = ::new char**[times]) || !(*p = ::new char*[times * levels]))
+	{
+		llerrs << "memory initialization for p failed" << llendl ;
+	}
+
+	//init
+	for(i = 0 ; i < times; i++)
+	{
+		p[i] = *p + i * levels ;
+		for(j = 0 ; j < levels; j++)
+		{
+			p[i][j] = NULL ;
+		}
+	}
+
+	//allocation
+	U32 size ;
+	for(i = 0 ; i < times ; i++)
+	{
+		for(j = 0 ; j < levels; j++) 
+		{
+			size = min_size + j * stride ;
+			p[i][j] = ALLOCATE_MEM(sPool, size) ;
+
+			total_allocated_size+= size ;
+
+			*(U32*)p[i][j] = i ;
+			*((U32*)p[i][j] + 1) = j ;
+			//p[i][j][size - 1] = '\0' ; //access the last element to verify the success of the allocation.
+
+			//randomly release memory
+			if(random_deletion)
+			{
+				S32 k = rand() % levels ;
+
+				if(p[i][k])
+				{
+					llassert_always(*(U32*)p[i][k] == i && *((U32*)p[i][k] + 1) == k) ;
+					FREE_MEM(sPool, p[i][k]) ;
+					total_allocated_size -= min_size + k * stride ;
+					p[i][k] = NULL ;
+				}
+			}
+		}
+	}
+
+	//output pool allocation statistics
+	if(output_statistics)
+	{
+	}
+
+	//release all memory allocations
+	for(i = 0 ; i < times; i++)
+	{
+		for(j = 0 ; j < levels; j++)
+		{
+			if(p[i][j])
+			{
+				llassert_always(*(U32*)p[i][j] == i && *((U32*)p[i][j] + 1) == j) ;
+				FREE_MEM(sPool, p[i][j]) ;
+				total_allocated_size -= min_size + j * stride ;
+				p[i][j] = NULL ;
+			}
+		}
+	}
+
+	::delete[] *p ;
+	::delete[] p ;
+}
+
+void LLPrivateMemoryPoolTester::testAndTime(U32 size, U32 times)
+{
+	LLTimer timer ;
+
+	llinfos << " -**********************- " << llendl ;
+	llinfos << "test size: " << size << " test times: " << times << llendl ;
+
+	timer.reset() ;
+	char** p = new char*[times] ;
+		
+	//using the customized memory pool
+	//allocation
+	for(U32 i = 0 ; i < times; i++)
+	{
+		p[i] = ALLOCATE_MEM(sPool, size) ;
+		if(!p[i])
+		{
+			llerrs << "allocation failed" << llendl ;
+		}
+	}
+	//de-allocation
+	for(U32 i = 0 ; i < times; i++)
+	{
+		FREE_MEM(sPool, p[i]) ;
+		p[i] = NULL ;
+	}
+	llinfos << "time spent using customized memory pool: " << timer.getElapsedTimeF32() << llendl ;
+
+	timer.reset() ;
+
+	//using the standard allocator/de-allocator:
+	//allocation
+	for(U32 i = 0 ; i < times; i++)
+	{
+		p[i] = ::new char[size] ;
+		if(!p[i])
+		{
+			llerrs << "allocation failed" << llendl ;
+		}
+	}
+	//de-allocation
+	for(U32 i = 0 ; i < times; i++)
+	{
+		::delete[] p[i] ;
+		p[i] = NULL ;
+	}
+	llinfos << "time spent using standard allocator/de-allocator: " << timer.getElapsedTimeF32() << llendl ;
+
+	delete[] p;
+}
+
+void LLPrivateMemoryPoolTester::correctnessTest() 
+{
+	//try many different sized allocation, and all kinds of edge cases, access the allocated memory 
+	//to see if allocation is right.
+	
+	//edge case
+	char* p = ALLOCATE_MEM(sPool, 0) ;
+	FREE_MEM(sPool, p) ;
+
+	//small sized
+	// [8 bytes, 2KB), each asks for 256 allocations and deallocations
+	test(8, 2040, 8, 256, true, true) ;
+	
+	//medium sized
+	//[2KB, 512KB), each asks for 16 allocations and deallocations
+	test(2048, 512 * 1024 - 2048, 2048, 16, true, true) ;
+
+	//large sized
+	//[512KB, 4MB], each asks for 8 allocations and deallocations
+	test(512 * 1024, 4 * 1024 * 1024, 64 * 1024, 6, true, true) ;
+}
+
+void LLPrivateMemoryPoolTester::performanceTest() 
+{
+	U32 test_size[3] = {768, 3* 1024, 3* 1024 * 1024};
+	
+	//small sized
+	testAndTime(test_size[0], 8) ;
+	
+	//medium sized
+	testAndTime(test_size[1], 8) ;
+
+	//large sized
+	testAndTime(test_size[2], 8) ;
+}
+
+void LLPrivateMemoryPoolTester::fragmentationtest() 
+{
+	//for internal fragmentation statistics:
+	//every time when asking for a new chunk during correctness test, and performance test,
+	//print out the chunk usage statistices.
+}
+#endif
+//--------------------------------------------------------------------
diff --git a/indra/llcommon/llmemory.h b/indra/llcommon/llmemory.h
index 3bd1403576..db753f0d8b 100644
--- a/indra/llcommon/llmemory.h
+++ b/indra/llcommon/llmemory.h
@@ -27,7 +27,6 @@
 #define LLMEMORY_H
 
 #include "llmemtype.h"
-
 #if LL_DEBUG
 inline void* ll_aligned_malloc( size_t size, int align )
 {
@@ -105,6 +104,10 @@ inline void ll_aligned_free_32(void *p)
 #define ll_aligned_free_32 free
 #endif // LL_DEBUG
 
+#ifndef __DEBUG_PRIVATE_MEM__
+#define __DEBUG_PRIVATE_MEM__  0
+#endif
+
 class LL_COMMON_API LLMemory
 {
 public:
@@ -115,8 +118,24 @@ public:
 	// Return value is zero if not known.
 	static U64 getCurrentRSS();
 	static U32 getWorkingSetSize();
+	static void* tryToAlloc(void* address, U32 size);
+	static void initMaxHeapSizeGB(F32 max_heap_size_gb, BOOL prevent_heap_failure);
+	static void updateMemoryInfo() ;
+	static void logMemoryInfo(BOOL update = FALSE);
+	static S32  isMemoryPoolLow();
+
+	static U32 getAvailableMemKB() ;
+	static U32 getMaxMemKB() ;
+	static U32 getAllocatedMemKB() ;
 private:
 	static char* reserveMem;
+	static U32 sAvailPhysicalMemInKB ;
+	static U32 sMaxPhysicalMemInKB ;
+	static U32 sAllocatedMemInKB;
+	static U32 sAllocatedPageSizeInKB ;
+
+	static U32 sMaxHeapSizeInKB;
+	static BOOL sEnableMemoryFailurePrevention;
 };
 
 //----------------------------------------------------------------------------
@@ -163,6 +182,326 @@ private:
 
 //----------------------------------------------------------------------------
 
+
+//
+//class LLPrivateMemoryPool defines a private memory pool for an application to use, so the application does not
+//need to access the heap directly fro each memory allocation. Throught this, the allocation speed is faster, 
+//and reduces virtaul address space gragmentation problem.
+//Note: this class is thread-safe by passing true to the constructor function. However, you do not need to do this unless
+//you are sure the memory allocation and de-allocation will happen in different threads. To make the pool thread safe
+//increases allocation and deallocation cost.
+//
+class LL_COMMON_API LLPrivateMemoryPool
+{
+	friend class LLPrivateMemoryPoolManager ;
+
+public:
+	class LL_COMMON_API LLMemoryBlock //each block is devided into slots uniformly
+	{
+	public: 
+		LLMemoryBlock() ;
+		~LLMemoryBlock() ;
+
+		void init(char* buffer, U32 buffer_size, U32 slot_size) ;
+		void setBuffer(char* buffer, U32 buffer_size) ;
+
+		char* allocate() ;
+		void  freeMem(void* addr) ;
+
+		bool empty() {return !mAllocatedSlots;}
+		bool isFull() {return mAllocatedSlots == mTotalSlots;}
+		bool isFree() {return !mTotalSlots;}
+
+		U32  getSlotSize()const {return mSlotSize;}
+		U32  getTotalSlots()const {return mTotalSlots;}
+		U32  getBufferSize()const {return mBufferSize;}
+		char* getBuffer() const {return mBuffer;}
+
+		//debug use
+		void resetBitMap() ;
+	private:
+		char* mBuffer;
+		U32   mSlotSize ; //when the block is not initialized, it is the buffer size.
+		U32   mBufferSize ;
+		U32   mUsageBits ;
+		U8    mTotalSlots ;
+		U8    mAllocatedSlots ;
+		U8    mDummySize ; //size of extra bytes reserved for mUsageBits.
+
+	public:
+		LLMemoryBlock* mPrev ;
+		LLMemoryBlock* mNext ;
+		LLMemoryBlock* mSelf ;
+
+		struct CompareAddress
+		{
+			bool operator()(const LLMemoryBlock* const& lhs, const LLMemoryBlock* const& rhs)
+			{
+				return (U32)lhs->getBuffer() < (U32)rhs->getBuffer();
+			}
+		};
+	};
+
+	class LL_COMMON_API LLMemoryChunk //is divided into memory blocks.
+	{
+	public:
+		LLMemoryChunk() ;
+		~LLMemoryChunk() ;
+
+		void init(char* buffer, U32 buffer_size, U32 min_slot_size, U32 max_slot_size, U32 min_block_size, U32 max_block_size) ;
+		void setBuffer(char* buffer, U32 buffer_size) ;
+
+		bool empty() ;
+		
+		char* allocate(U32 size) ;
+		void  freeMem(void* addr) ;
+
+		char* getBuffer() const {return mBuffer;}
+		U32 getBufferSize() const {return mBufferSize;}
+		U32 getAllocatedSize() const {return mAlloatedSize;}
+
+		bool containsAddress(const char* addr) const;
+
+		static U32 getMaxOverhead(U32 data_buffer_size, U32 min_slot_size, 
+													   U32 max_slot_size, U32 min_block_size, U32 max_block_size) ;
+	
+		void dump() ;
+
+	private:
+		U32 getPageIndex(U32 addr) ;
+		U32 getBlockLevel(U32 size) ;
+		U16 getPageLevel(U32 size) ;
+		LLMemoryBlock* addBlock(U32 blk_idx) ;
+		void popAvailBlockList(U32 blk_idx) ;
+		void addToFreeSpace(LLMemoryBlock* blk) ;
+		void removeFromFreeSpace(LLMemoryBlock* blk) ;
+		void removeBlock(LLMemoryBlock* blk) ;
+		void addToAvailBlockList(LLMemoryBlock* blk) ;
+		U32  calcBlockSize(U32 slot_size);
+		LLMemoryBlock* createNewBlock(LLMemoryBlock* blk, U32 buffer_size, U32 slot_size, U32 blk_idx) ;
+
+	private:
+		LLMemoryBlock** mAvailBlockList ;//256 by mMinSlotSize
+		LLMemoryBlock** mFreeSpaceList;
+		LLMemoryBlock*  mBlocks ; //index of blocks by address.
+		
+		char* mBuffer ;
+		U32   mBufferSize ;
+		char* mDataBuffer ;
+		char* mMetaBuffer ;
+		U32   mMinBlockSize ;
+		U32   mMinSlotSize ;
+		U32   mMaxSlotSize ;
+		U32   mAlloatedSize ;
+		U16   mBlockLevels;
+		U16   mPartitionLevels;
+
+	public:
+		//form a linked list
+		LLMemoryChunk* mNext ;
+		LLMemoryChunk* mPrev ;
+	} ;
+
+private:
+	LLPrivateMemoryPool(S32 type) ;
+	~LLPrivateMemoryPool() ;
+
+	char *allocate(U32 size) ;
+	void  freeMem(void* addr) ;
+	
+	void  dump() ;
+	U32   getTotalAllocatedSize() ;
+	U32   getTotalReservedSize() {return mReservedPoolSize;}
+	S32   getType() const {return mType; }
+	bool  isEmpty() const {return !mNumOfChunks; }
+
+private:
+	void lock() ;
+	void unlock() ;	
+	S32 getChunkIndex(U32 size) ;
+	LLMemoryChunk*  addChunk(S32 chunk_index) ;
+	void checkSize(U32 asked_size) ;
+	void removeChunk(LLMemoryChunk* chunk) ;
+	U16  findHashKey(const char* addr);
+	void addToHashTable(LLMemoryChunk* chunk) ;
+	void removeFromHashTable(LLMemoryChunk* chunk) ;
+	void rehash() ;
+	bool fillHashTable(U16 start, U16 end, LLMemoryChunk* chunk) ;
+	LLMemoryChunk* findChunk(const char* addr) ;
+
+	void destroyPool() ;
+
+public:
+	enum
+	{
+		SMALL_ALLOCATION = 0, //from 8 bytes to 2KB(exclusive), page size 2KB, max chunk size is 4MB.
+		MEDIUM_ALLOCATION,    //from 2KB to 512KB(exclusive), page size 32KB, max chunk size 4MB
+		LARGE_ALLOCATION,     //from 512KB to 4MB(inclusive), page size 64KB, max chunk size 16MB
+		SUPER_ALLOCATION      //allocation larger than 4MB.
+	};
+
+	enum
+	{
+		STATIC = 0 ,       //static pool(each alllocation stays for a long time) without threading support
+		VOLATILE,          //Volatile pool(each allocation stays for a very short time) without threading support
+		STATIC_THREADED,   //static pool with threading support
+		VOLATILE_THREADED, //volatile pool with threading support
+		MAX_TYPES
+	}; //pool types
+
+private:
+	LLMutex* mMutexp ;
+	U32  mMaxPoolSize;
+	U32  mReservedPoolSize ;	
+
+	LLMemoryChunk* mChunkList[SUPER_ALLOCATION] ; //all memory chunks reserved by this pool, sorted by address	
+	U16 mNumOfChunks ;
+	U16 mHashFactor ;
+
+	S32 mType ;
+
+	class LLChunkHashElement
+	{
+	public:
+		LLChunkHashElement() {mFirst = NULL ; mSecond = NULL ;}
+
+		bool add(LLMemoryChunk* chunk) ;
+		void remove(LLMemoryChunk* chunk) ;
+		LLMemoryChunk* findChunk(const char* addr) ;
+
+		bool empty() {return !mFirst && !mSecond; }
+		bool full()  {return mFirst && mSecond; }
+		bool hasElement(LLMemoryChunk* chunk) {return mFirst == chunk || mSecond == chunk;}
+
+	private:
+		LLMemoryChunk* mFirst ;
+		LLMemoryChunk* mSecond ;
+	};
+	std::vector<LLChunkHashElement> mChunkHashList ;
+};
+
+class LL_COMMON_API LLPrivateMemoryPoolManager
+{
+private:
+	LLPrivateMemoryPoolManager(BOOL enabled) ;
+	~LLPrivateMemoryPoolManager() ;
+
+public:	
+	static LLPrivateMemoryPoolManager* getInstance() ;
+	static void initClass(BOOL enabled) ;
+	static void destroyClass() ;
+
+	LLPrivateMemoryPool* newPool(S32 type) ;
+	void deletePool(LLPrivateMemoryPool* pool) ;
+
+private:
+	static LLPrivateMemoryPoolManager* sInstance ;
+	std::vector<LLPrivateMemoryPool*> mPoolList ;
+	BOOL mPrivatePoolEnabled;
+
+public:
+	//debug and statistics info.
+	void updateStatistics() ;
+
+	U32 mTotalReservedSize ;
+	U32 mTotalAllocatedSize ;
+
+public:
+#if __DEBUG_PRIVATE_MEM__
+	static char* allocate(LLPrivateMemoryPool* poolp, U32 size, const char* function, const int line) ;	
+	
+	typedef std::map<char*, std::string> mem_allocation_info_t ;
+	static mem_allocation_info_t sMemAllocationTracker;
+#else
+	static char* allocate(LLPrivateMemoryPool* poolp, U32 size) ;	
+#endif
+	static void  freeMem(LLPrivateMemoryPool* poolp, void* addr) ;
+};
+
+//-------------------------------------------------------------------------------------
+#if __DEBUG_PRIVATE_MEM__
+#define ALLOCATE_MEM(poolp, size) LLPrivateMemoryPoolManager::allocate((poolp), (size), __FUNCTION__, __LINE__)
+#else
+#define ALLOCATE_MEM(poolp, size) LLPrivateMemoryPoolManager::allocate((poolp), (size))
+#endif
+#define FREE_MEM(poolp, addr) LLPrivateMemoryPoolManager::freeMem((poolp), (addr))
+//-------------------------------------------------------------------------------------
+
+//
+//the below singleton is used to test the private memory pool.
+//
+#if 0
+class LL_COMMON_API LLPrivateMemoryPoolTester
+{
+private:
+	LLPrivateMemoryPoolTester() ;
+	~LLPrivateMemoryPoolTester() ;
+
+public:
+	static LLPrivateMemoryPoolTester* getInstance() ;
+	static void destroy() ;
+
+	void run(S32 type) ;	
+
+private:
+	void correctnessTest() ;
+	void performanceTest() ;
+	void fragmentationtest() ;
+
+	void test(U32 min_size, U32 max_size, U32 stride, U32 times, bool random_deletion, bool output_statistics) ;
+	void testAndTime(U32 size, U32 times) ;
+
+#if 0
+public:
+	void* operator new(size_t size)
+	{
+		return (void*)sPool->allocate(size) ;
+	}
+    void  operator delete(void* addr)
+	{
+		sPool->freeMem(addr) ;
+	}
+	void* operator new[](size_t size)
+	{
+		return (void*)sPool->allocate(size) ;
+	}
+    void  operator delete[](void* addr)
+	{
+		sPool->freeMem(addr) ;
+	}
+#endif
+
+private:
+	static LLPrivateMemoryPoolTester* sInstance;
+	static LLPrivateMemoryPool* sPool ;
+	static LLPrivateMemoryPool* sThreadedPool ;
+};
+#if 0
+//static
+void* LLPrivateMemoryPoolTester::operator new(size_t size)
+{
+	return (void*)sPool->allocate(size) ;
+}
+
+//static
+void  LLPrivateMemoryPoolTester::operator delete(void* addr)
+{
+	sPool->free(addr) ;
+}
+
+//static
+void* LLPrivateMemoryPoolTester::operator new[](size_t size)
+{
+	return (void*)sPool->allocate(size) ;
+}
+
+//static
+void  LLPrivateMemoryPoolTester::operator delete[](void* addr)
+{
+	sPool->free(addr) ;
+}
+#endif
+#endif
 // LLRefCount moved to llrefcount.h
 
 // LLPointer moved to llpointer.h
diff --git a/indra/llcommon/llscopedvolatileaprpool.h b/indra/llcommon/llscopedvolatileaprpool.h
new file mode 100644
index 0000000000..dbaf4edcad
--- /dev/null
+++ b/indra/llcommon/llscopedvolatileaprpool.h
@@ -0,0 +1,52 @@
+/**
+ * @file llscopedvolatileaprpool.h
+ * @brief Implementation of LLScopedVolatileAPRPool
+ *
+ * $LicenseInfo:firstyear=2010&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2011, 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 LL_LLSCOPEDVOLATILEAPRPOOL_H
+#define LL_LLSCOPEDVOLATILEAPRPOOL_H
+
+#include "llthread.h"
+
+/** Scoped volatile memory pool.
+ *
+ * As the LLVolatileAPRPool should never keep allocations very
+ * long, its most common use is for allocations with a lifetime
+ * equal to it's scope.
+ *
+ * This is a convenience class that makes just a little easier to type.
+ */
+class LL_COMMON_API LLScopedVolatileAPRPool
+{
+private:
+	LLVolatileAPRPool& mPool;
+	apr_pool_t* mScopedAPRpool;		// The use of apr_pool_t is OK here.
+public:
+	LLScopedVolatileAPRPool() : mPool(LLThreadLocalData::tldata().mVolatileAPRPool), mScopedAPRpool(mPool.getVolatileAPRPool()) { }
+	~LLScopedVolatileAPRPool() { mPool.clearVolatileAPRPool(); }
+	//! @attention Only use this to pass the underlaying pointer to a libapr-1 function that requires it.
+	operator apr_pool_t*() const { return mScopedAPRpool; }		// The use of apr_pool_t is OK here.
+};
+
+#endif
diff --git a/indra/llcommon/llstring.cpp b/indra/llcommon/llstring.cpp
index f3b48b0156..e7fe656808 100644
--- a/indra/llcommon/llstring.cpp
+++ b/indra/llcommon/llstring.cpp
@@ -936,13 +936,18 @@ LLStringUtil::size_type LLStringUtil::getSubstitution(const std::string& instr,
 {
 	const std::string delims (",");
 	
-	// Find the first ]
-	size_type pos2 = instr.find(']', start);
+	// Find the first [
+	size_type pos1 = instr.find('[', start);
+	if (pos1 == std::string::npos)
+		return std::string::npos;
+
+	//Find the first ] after the initial [
+	size_type pos2 = instr.find(']', pos1);
 	if (pos2 == std::string::npos)
 		return std::string::npos;
 
-	// Find the last [ before ]
-	size_type pos1 = instr.find_last_of('[', pos2-1);
+	// Find the last [ before ] in case of nested [[]]
+	pos1 = instr.find_last_of('[', pos2-1);
 	if (pos1 == std::string::npos || pos1 < start)
 		return std::string::npos;
 	
diff --git a/indra/llcommon/llthread.cpp b/indra/llcommon/llthread.cpp
index 4063cc730b..bdde1b5c48 100644
--- a/indra/llcommon/llthread.cpp
+++ b/indra/llcommon/llthread.cpp
@@ -36,6 +36,12 @@
 #include <sched.h>
 #endif
 
+#if !LL_DARWIN
+U32 ll_thread_local local_thread_ID = 0;
+#endif 
+
+U32 LLThread::sIDIter = 0;
+
 //----------------------------------------------------------------------------
 // Usage:
 // void run_func(LLThread* thread)
@@ -56,12 +62,6 @@
 // 
 //----------------------------------------------------------------------------
 
-#if !LL_DARWIN
-U32 ll_thread_local sThreadID = 0;
-#endif 
-
-U32 LLThread::sIDIter = 0;
-
 LL_COMMON_API void assert_main_thread()
 {
 	static U32 s_thread_id = LLThread::currentID();
@@ -79,9 +79,12 @@ void *APR_THREAD_FUNC LLThread::staticRun(apr_thread_t *apr_threadp, void *datap
 	LLThread *threadp = (LLThread *)datap;
 
 #if !LL_DARWIN
-	sThreadID = threadp->mID;
+	local_thread_ID = threadp->mID;
 #endif
 
+	// Create a thread local data.
+	LLThreadLocalData::create(threadp);
+
 	// Run the user supplied function
 	threadp->run();
 
@@ -94,40 +97,22 @@ void *APR_THREAD_FUNC LLThread::staticRun(apr_thread_t *apr_threadp, void *datap
 }
 
 
-LLThread::LLThread(const std::string& name, apr_pool_t *poolp) :
-	mPaused(FALSE),
+LLThread::LLThread(std::string const& name) :
+	mPaused(false),
 	mName(name),
 	mAPRThreadp(NULL),
-	mStatus(STOPPED)
+	mStatus(STOPPED),
+	mThreadLocalData(NULL)
 {
-	mID = ++sIDIter;
+	mID = ++sIDIter; //flaw: assume this is called only in the main thread!
 
-	// Thread creation probably CAN be paranoid about APR being initialized, if necessary
-	if (poolp)
-	{
-		mIsLocalPool = FALSE;
-		mAPRPoolp = poolp;
-	}
-	else
-	{
-		mIsLocalPool = TRUE;
-		apr_pool_create(&mAPRPoolp, NULL); // Create a subpool for this thread
-	}
-	mRunCondition = new LLCondition(mAPRPoolp);
-
-	mLocalAPRFilePoolp = NULL ;
+	mRunCondition = new LLCondition;
 }
 
 
 LLThread::~LLThread()
 {
 	shutdown();
-
-	if(mLocalAPRFilePoolp)
-	{
-		delete mLocalAPRFilePoolp ;
-		mLocalAPRFilePoolp = NULL ;
-	}
 }
 
 void LLThread::shutdown()
@@ -164,7 +149,7 @@ void LLThread::shutdown()
 		if (!isStopped())
 		{
 			// This thread just wouldn't stop, even though we gave it time
-			//llwarns << "LLThread::~LLThread() exiting thread before clean exit!" << llendl;
+			//llwarns << "LLThread::shutdown() exiting thread before clean exit!" << llendl;
 			// Put a stake in its heart.
 			apr_thread_exit(mAPRThreadp, -1);
 			return;
@@ -174,15 +159,8 @@ void LLThread::shutdown()
 
 	delete mRunCondition;
 	mRunCondition = 0;
-	
-	if (mIsLocalPool && mAPRPoolp)
-	{
-		apr_pool_destroy(mAPRPoolp);
-		mAPRPoolp = 0;
-	}
 }
 
-
 void LLThread::start()
 {
 	llassert(isStopped());
@@ -191,7 +169,7 @@ void LLThread::start()
 	mStatus = RUNNING;
 
 	apr_status_t status =
-		apr_thread_create(&mAPRThreadp, NULL, staticRun, (void *)this, mAPRPoolp);
+		apr_thread_create(&mAPRThreadp, NULL, staticRun, (void *)this, tldata().mRootPool());
 	
 	if(status == APR_SUCCESS)
 	{	
@@ -216,7 +194,7 @@ void LLThread::pause()
 	if (!mPaused)
 	{
 		// this will cause the thread to stop execution as soon as checkPause() is called
-		mPaused = 1;		// Does not need to be atomic since this is only set/unset from the main thread
+		mPaused = true;		// Does not need to be atomic since this is only set/unset from the main thread
 	}	
 }
 
@@ -224,7 +202,7 @@ void LLThread::unpause()
 {
 	if (mPaused)
 	{
-		mPaused = 0;
+		mPaused = false;
 	}
 
 	wake(); // wake up the thread if necessary
@@ -301,116 +279,76 @@ void LLThread::wakeLocked()
 	}
 }
 
-//============================================================================
-
-LLMutex::LLMutex(apr_pool_t *poolp) :
-	mAPRMutexp(NULL), mCount(0), mLockingThread(NO_THREAD)
-{
-	//if (poolp)
-	//{
-	//	mIsLocalPool = FALSE;
-	//	mAPRPoolp = poolp;
-	//}
-	//else
-	{
-		mIsLocalPool = TRUE;
-		apr_pool_create(&mAPRPoolp, NULL); // Create a subpool for this thread
-	}
-	apr_thread_mutex_create(&mAPRMutexp, APR_THREAD_MUTEX_UNNESTED, mAPRPoolp);
-}
+#ifdef SHOW_ASSERT
+// This allows the use of llassert(is_main_thread()) to assure the current thread is the main thread.
+static apr_os_thread_t main_thread_id;
+LL_COMMON_API bool is_main_thread(void) { return apr_os_thread_equal(main_thread_id, apr_os_thread_current()); }
+#endif
 
+// The thread private handle to access the LLThreadLocalData instance.
+apr_threadkey_t* LLThreadLocalData::sThreadLocalDataKey;
 
-LLMutex::~LLMutex()
+//static
+void LLThreadLocalData::init(void)
 {
-#if MUTEX_DEBUG
-	//bad assertion, the subclass LLSignal might be "locked", and that's OK
-	//llassert_always(!isLocked()); // better not be locked!
-#endif
-	apr_thread_mutex_destroy(mAPRMutexp);
-	mAPRMutexp = NULL;
-	if (mIsLocalPool)
+	// Only do this once.
+	if (sThreadLocalDataKey)
 	{
-		apr_pool_destroy(mAPRPoolp);
+		return;
 	}
-}
 
+	apr_status_t status = apr_threadkey_private_create(&sThreadLocalDataKey, &LLThreadLocalData::destroy, LLAPRRootPool::get()());
+	ll_apr_assert_status(status);   // Or out of memory, or system-imposed limit on the
+									// total number of keys per process {PTHREAD_KEYS_MAX}
+									// has been exceeded.
 
-void LLMutex::lock()
-{
-#if LL_DARWIN
-	if (mLockingThread == LLThread::currentID())
-#else
-	if (mLockingThread == sThreadID)
-#endif
-	{ //redundant lock
-		mCount++;
-		return;
-	}
-	
-	apr_thread_mutex_lock(mAPRMutexp);
-	
-#if MUTEX_DEBUG
-	// Have to have the lock before we can access the debug info
-	U32 id = LLThread::currentID();
-	if (mIsLocked[id] != FALSE)
-		llerrs << "Already locked in Thread: " << id << llendl;
-	mIsLocked[id] = TRUE;
-#endif
+	// Create the thread-local data for the main thread (this function is called by the main thread).
+	LLThreadLocalData::create(NULL);
 
-#if LL_DARWIN
-	mLockingThread = LLThread::currentID();
-#else
-	mLockingThread = sThreadID;
+#ifdef SHOW_ASSERT
+	// This function is called by the main thread.
+	main_thread_id = apr_os_thread_current();
 #endif
 }
 
-void LLMutex::unlock()
+// This is called once for every thread when the thread is destructed.
+//static
+void LLThreadLocalData::destroy(void* thread_local_data)
 {
-	if (mCount > 0)
-	{ //not the root unlock
-		mCount--;
-		return;
-	}
-	
-#if MUTEX_DEBUG
-	// Access the debug info while we have the lock
-	U32 id = LLThread::currentID();
-	if (mIsLocked[id] != TRUE)
-		llerrs << "Not locked in Thread: " << id << llendl;	
-	mIsLocked[id] = FALSE;
-#endif
-
-	mLockingThread = NO_THREAD;
-	apr_thread_mutex_unlock(mAPRMutexp);
+	delete static_cast<LLThreadLocalData*>(thread_local_data);
 }
 
-bool LLMutex::isLocked()
+//static
+void LLThreadLocalData::create(LLThread* threadp)
 {
-	apr_status_t status = apr_thread_mutex_trylock(mAPRMutexp);
-	if (APR_STATUS_IS_EBUSY(status))
+	LLThreadLocalData* new_tld = new LLThreadLocalData;
+	if (threadp)
 	{
-		return true;
-	}
-	else
-	{
-		apr_thread_mutex_unlock(mAPRMutexp);
-		return false;
+		threadp->mThreadLocalData = new_tld;
 	}
+	apr_status_t status = apr_threadkey_private_set(new_tld, sThreadLocalDataKey);
+	llassert_always(status == APR_SUCCESS);
 }
 
-U32 LLMutex::lockingThread() const
+//static
+LLThreadLocalData& LLThreadLocalData::tldata(void)
 {
-	return mLockingThread;
+	if (!sThreadLocalDataKey)
+	{
+		LLThreadLocalData::init();
+	}
+
+	void* data;
+	apr_status_t status = apr_threadkey_private_get(&data, sThreadLocalDataKey);
+	llassert_always(status == APR_SUCCESS);
+	return *static_cast<LLThreadLocalData*>(data);
 }
 
 //============================================================================
 
-LLCondition::LLCondition(apr_pool_t *poolp) :
-	LLMutex(poolp)
+LLCondition::LLCondition(LLAPRPool& parent) : LLMutex(parent)
 {
-	// base class (LLMutex) has already ensured that mAPRPoolp is set up.
-
-	apr_thread_cond_create(&mAPRCondp, mAPRPoolp);
+	apr_thread_cond_create(&mAPRCondp, mPool());
 }
 
 
@@ -423,15 +361,6 @@ LLCondition::~LLCondition()
 
 void LLCondition::wait()
 {
-	if (!isLocked())
-	{ //mAPRMutexp MUST be locked before calling apr_thread_cond_wait
-		apr_thread_mutex_lock(mAPRMutexp);
-#if MUTEX_DEBUG
-		// avoid asserts on destruction in non-release builds
-		U32 id = LLThread::currentID();
-		mIsLocked[id] = TRUE;
-#endif
-	}
 	apr_thread_cond_wait(mAPRCondp, mAPRMutexp);
 }
 
@@ -446,6 +375,44 @@ void LLCondition::broadcast()
 }
 
 //============================================================================
+LLMutexBase::LLMutexBase() :
+	mLockingThread(NO_THREAD),
+	mCount(0)
+{
+}
+
+void LLMutexBase::lock() 
+{ 
+#if LL_DARWIN
+	if (mLockingThread == LLThread::currentID())
+#else
+	if (mLockingThread == local_thread_ID)
+#endif
+	{ //redundant lock
+		mCount++;
+		return;
+	}
+
+	apr_thread_mutex_lock(mAPRMutexp); 
+
+#if LL_DARWIN
+	mLockingThread = LLThread::currentID();
+#else
+	mLockingThread = local_thread_ID;
+#endif
+}
+
+void LLMutexBase::unlock() 
+{ 
+	if (mCount > 0)
+	{ //not the root unlock
+		mCount--;
+		return;
+	}
+	mLockingThread = NO_THREAD;
+
+	apr_thread_mutex_unlock(mAPRMutexp); 
+}
 
 //----------------------------------------------------------------------------
 
@@ -457,7 +424,7 @@ void LLThreadSafeRefCount::initThreadSafeRefCount()
 {
 	if (!sMutex)
 	{
-		sMutex = new LLMutex(0);
+		sMutex = new LLMutex;
 	}
 }
 
diff --git a/indra/llcommon/llthread.h b/indra/llcommon/llthread.h
index 40291a2569..c732e3bc77 100644
--- a/indra/llcommon/llthread.h
+++ b/indra/llcommon/llthread.h
@@ -29,7 +29,13 @@
 
 #include "llapp.h"
 #include "llapr.h"
+#include "llmemory.h"
 #include "apr_thread_cond.h"
+#include "llaprpool.h"
+
+#ifdef SHOW_ASSERT
+extern LL_COMMON_API bool is_main_thread(void);
+#endif
 
 class LLThread;
 class LLMutex;
@@ -41,6 +47,22 @@ class LLCondition;
 #define ll_thread_local __thread
 #endif
 
+class LL_COMMON_API LLThreadLocalData
+{
+private:
+	static apr_threadkey_t* sThreadLocalDataKey;
+
+public:
+	// Thread-local memory pools.
+	LLAPRRootPool mRootPool;
+	LLVolatileAPRPool mVolatileAPRPool;
+
+	static void init(void);
+	static void destroy(void* thread_local_data);
+	static void create(LLThread* pthread);
+	static LLThreadLocalData& tldata(void);
+};
+
 class LL_COMMON_API LLThread
 {
 private:
@@ -54,7 +76,7 @@ public:
 		QUITTING= 2 	// Someone wants this thread to quit
 	} EThreadStatus;
 
-	LLThread(const std::string& name, apr_pool_t *poolp = NULL);
+	LLThread(std::string const& name);
 	virtual ~LLThread(); // Warning!  You almost NEVER want to destroy a thread unless it's in the STOPPED state.
 	virtual void shutdown(); // stops the thread
 	
@@ -69,7 +91,7 @@ public:
 	// Called from MAIN THREAD.
 	void pause();
 	void unpause();
-	bool isPaused() { return isStopped() || mPaused == TRUE; }
+	bool isPaused() { return isStopped() || mPaused; }
 	
 	// Cause the thread to wake up and check its condition
 	void wake();
@@ -83,13 +105,11 @@ public:
 	// this kicks off the apr thread
 	void start(void);
 
-	apr_pool_t *getAPRPool() { return mAPRPoolp; }
-	LLVolatileAPRPool* getLocalAPRFilePool() { return mLocalAPRFilePoolp ; }
-
-	U32 getID() const { return mID; }
+	// Return thread-local data for the current thread.
+	static LLThreadLocalData& tldata(void) { return LLThreadLocalData::tldata(); }
 
 private:
-	BOOL				mPaused;
+	bool				mPaused;
 	
 	// static function passed to APR thread creation routine
 	static void *APR_THREAD_FUNC staticRun(apr_thread_t *apr_threadp, void *datap);
@@ -99,15 +119,11 @@ protected:
 	LLCondition*		mRunCondition;
 
 	apr_thread_t		*mAPRThreadp;
-	apr_pool_t			*mAPRPoolp;
-	BOOL				mIsLocalPool;
 	EThreadStatus		mStatus;
 	U32					mID;
-
-	//a local apr_pool for APRFile operations in this thread. If it exists, LLAPRFile::sAPRFilePoolp should not be used.
-	//Note: this pool is used by APRFile ONLY, do NOT use it for any other purposes.
-	//      otherwise it will cause severe memory leaking!!! --bao
-	LLVolatileAPRPool  *mLocalAPRFilePoolp ; 
+	
+	friend void LLThreadLocalData::create(LLThread* threadp);
+	LLThreadLocalData*	mThreadLocalData;
 
 	void setQuitting();
 	
@@ -137,7 +153,15 @@ protected:
 
 #define MUTEX_DEBUG (LL_DEBUG || LL_RELEASE_WITH_DEBUG_INFO)
 
-class LL_COMMON_API LLMutex
+#ifdef MUTEX_DEBUG
+// We really shouldn't be using recursive locks. Make sure of that in debug mode.
+#define MUTEX_FLAG APR_THREAD_MUTEX_UNNESTED
+#else
+// Use the fastest platform-optimal lock behavior (can be recursive or non-recursive).
+#define MUTEX_FLAG APR_THREAD_MUTEX_DEFAULT
+#endif
+
+class LL_COMMON_API LLMutexBase
 {
 public:
 	typedef enum
@@ -145,32 +169,73 @@ public:
 		NO_THREAD = 0xFFFFFFFF
 	} e_locking_thread;
 
-	LLMutex(apr_pool_t *apr_poolp); // NULL pool constructs a new pool for the mutex
-	virtual ~LLMutex();
-	
-	void lock();		// blocks
-	void unlock();
-	bool isLocked(); 	// non-blocking, but does do a lock/unlock so not free
-	U32 lockingThread() const; //get ID of locking thread
-	
+	LLMutexBase() ;
+
+	void lock() ;
+	void unlock() ;
+	// Returns true if lock was obtained successfully.
+	bool trylock() { return !APR_STATUS_IS_EBUSY(apr_thread_mutex_trylock(mAPRMutexp)); }
+
+	// non-blocking, but does do a lock/unlock so not free
+	bool isLocked() { bool is_not_locked = trylock(); if (is_not_locked) unlock(); return !is_not_locked; }
+
 protected:
-	apr_thread_mutex_t *mAPRMutexp;
+	// mAPRMutexp is initialized and uninitialized in the derived class.
+	apr_thread_mutex_t* mAPRMutexp;
 	mutable U32			mCount;
 	mutable U32			mLockingThread;
-	
-	apr_pool_t			*mAPRPoolp;
-	BOOL				mIsLocalPool;
-	
-#if MUTEX_DEBUG
-	std::map<U32, BOOL> mIsLocked;
+};
+
+class LL_COMMON_API LLMutex : public LLMutexBase
+{
+public:
+	LLMutex(LLAPRPool& parent = LLThread::tldata().mRootPool) : mPool(parent)
+	{
+		apr_thread_mutex_create(&mAPRMutexp, MUTEX_FLAG, mPool());
+	}
+	~LLMutex()
+	{
+		llassert(!isLocked()); // better not be locked!
+		apr_thread_mutex_destroy(mAPRMutexp);
+		mAPRMutexp = NULL;
+	}
+
+protected:
+	LLAPRPool mPool;
+};
+
+#if APR_HAS_THREADS
+// No need to use a root pool in this case.
+typedef LLMutex LLMutexRootPool;
+#else // APR_HAS_THREADS
+class LL_COMMON_API LLMutexRootPool : public LLMutexBase
+{
+public:
+	LLMutexRootPool(void)
+	{
+		apr_thread_mutex_create(&mAPRMutexp, MUTEX_FLAG, mRootPool());
+	}
+	~LLMutexRootPool()
+	{
+#if APR_POOL_DEBUG
+		// It is allowed to destruct root pools from a different thread.
+		mRootPool.grab_ownership();
 #endif
+		llassert(!isLocked());
+		apr_thread_mutex_destroy(mAPRMutexp);
+		mAPRMutexp = NULL;
+	}
+
+protected:
+	LLAPRRootPool mRootPool;
 };
+#endif // APR_HAS_THREADS
 
 // Actually a condition/mutex pair (since each condition needs to be associated with a mutex).
 class LL_COMMON_API LLCondition : public LLMutex
 {
 public:
-	LLCondition(apr_pool_t *apr_poolp); // Defaults to global pool, could use the thread pool as well.
+	LLCondition(LLAPRPool& parent = LLThread::tldata().mRootPool);
 	~LLCondition();
 	
 	void wait();		// blocks
@@ -181,10 +246,10 @@ protected:
 	apr_thread_cond_t *mAPRCondp;
 };
 
-class LLMutexLock
+class LL_COMMON_API LLMutexLock
 {
 public:
-	LLMutexLock(LLMutex* mutex)
+	LLMutexLock(LLMutexBase* mutex)
 	{
 		mMutex = mutex;
 		mMutex->lock();
@@ -194,7 +259,7 @@ public:
 		mMutex->unlock();
 	}
 private:
-	LLMutex* mMutex;
+	LLMutexBase* mMutex;
 };
 
 //============================================================================
diff --git a/indra/llcommon/llthreadsafequeue.cpp b/indra/llcommon/llthreadsafequeue.cpp
index 8a73e632a9..05d24944f3 100644
--- a/indra/llcommon/llthreadsafequeue.cpp
+++ b/indra/llcommon/llthreadsafequeue.cpp
@@ -34,19 +34,11 @@
 //-----------------------------------------------------------------------------
 
 
-LLThreadSafeQueueImplementation::LLThreadSafeQueueImplementation(apr_pool_t * pool, unsigned int capacity):
-	mOwnsPool(pool == 0),
-	mPool(pool),
+LLThreadSafeQueueImplementation::LLThreadSafeQueueImplementation(unsigned int capacity):
 	mQueue(0)
 {
-	if(mOwnsPool) {
-		apr_status_t status = apr_pool_create(&mPool, 0);
-		if(status != APR_SUCCESS) throw LLThreadSafeQueueError("failed to allocate pool");
-	} else {
-		; // No op.
-	}
-	
-	apr_status_t status = apr_queue_create(&mQueue, capacity, mPool);
+	mPool.create();
+	apr_status_t status = apr_queue_create(&mQueue, capacity, mPool());
 	if(status != APR_SUCCESS) throw LLThreadSafeQueueError("failed to allocate queue");
 }
 
@@ -59,7 +51,6 @@ LLThreadSafeQueueImplementation::~LLThreadSafeQueueImplementation()
 			" elements;" << "memory will be leaked" << LL_ENDL;
 		apr_queue_term(mQueue);
 	}
-	if(mOwnsPool && (mPool != 0)) apr_pool_destroy(mPool);
 }
 
 
diff --git a/indra/llcommon/llthreadsafequeue.h b/indra/llcommon/llthreadsafequeue.h
index 58cac38769..43d0b396f2 100644
--- a/indra/llcommon/llthreadsafequeue.h
+++ b/indra/llcommon/llthreadsafequeue.h
@@ -30,9 +30,9 @@
 
 #include <string>
 #include <stdexcept>
+#include "llaprpool.h"
 
 
-struct apr_pool_t; // From apr_pools.h
 class LLThreadSafeQueueImplementation; // See below.
 
 
@@ -75,7 +75,7 @@ struct apr_queue_t; // From apr_queue.h
 class LL_COMMON_API LLThreadSafeQueueImplementation
 {
 public:
-	LLThreadSafeQueueImplementation(apr_pool_t * pool, unsigned int capacity);
+	LLThreadSafeQueueImplementation(unsigned int capacity);
 	~LLThreadSafeQueueImplementation();
 	void pushFront(void * element);
 	bool tryPushFront(void * element);
@@ -84,8 +84,7 @@ public:
 	size_t size();
 	
 private:
-	bool mOwnsPool;
-	apr_pool_t * mPool;
+	LLAPRPool mPool;			// The pool used for mQueue.
 	apr_queue_t * mQueue;
 };
 
@@ -99,9 +98,8 @@ class LLThreadSafeQueue
 public:
 	typedef ElementT value_type;
 	
-	// If the pool is set to NULL one will be allocated and managed by this
-	// queue.
-	LLThreadSafeQueue(apr_pool_t * pool = 0, unsigned int capacity = 1024);
+	// Constructor.
+	LLThreadSafeQueue(unsigned int capacity = 1024);
 	
 	// Add an element to the front of queue (will block if the queue has
 	// reached capacity).
@@ -139,8 +137,8 @@ private:
 
 
 template<typename ElementT>
-LLThreadSafeQueue<ElementT>::LLThreadSafeQueue(apr_pool_t * pool, unsigned int capacity):
-	mImplementation(pool, capacity)
+LLThreadSafeQueue<ElementT>::LLThreadSafeQueue(unsigned int capacity) :
+	mImplementation(capacity)
 {
 	; // No op.
 }
diff --git a/indra/llcommon/llversionviewer.h b/indra/llcommon/llversionviewer.h
index 324507fe7a..ef55cfec89 100755
--- a/indra/llcommon/llversionviewer.h
+++ b/indra/llcommon/llversionviewer.h
@@ -29,7 +29,7 @@
 
 const S32 LL_VERSION_MAJOR = 3;
 const S32 LL_VERSION_MINOR = 0;
-const S32 LL_VERSION_PATCH = 4;
+const S32 LL_VERSION_PATCH = 5;
 const S32 LL_VERSION_BUILD = 0;
 
 const char * const LL_CHANNEL = "Second Life Developer";
diff --git a/indra/llcommon/llworkerthread.cpp b/indra/llcommon/llworkerthread.cpp
index 3ac50832fd..6b308bb917 100644
--- a/indra/llcommon/llworkerthread.cpp
+++ b/indra/llcommon/llworkerthread.cpp
@@ -37,12 +37,7 @@
 LLWorkerThread::LLWorkerThread(const std::string& name, bool threaded) :
 	LLQueuedThread(name, threaded)
 {
-	mDeleteMutex = new LLMutex(NULL);
-
-	if(!mLocalAPRFilePoolp)
-	{
-		mLocalAPRFilePoolp = new LLVolatileAPRPool() ;
-	}
+	mDeleteMutex = new LLMutex;
 }
 
 LLWorkerThread::~LLWorkerThread()
@@ -204,7 +199,6 @@ LLWorkerClass::LLWorkerClass(LLWorkerThread* workerthread, const std::string& na
 	  mWorkerClassName(name),
 	  mRequestHandle(LLWorkerThread::nullHandle()),
 	  mRequestPriority(LLWorkerThread::PRIORITY_NORMAL),
-	  mMutex(NULL),
 	  mWorkFlags(0)
 {
 	if (!mWorkerThread)
diff --git a/indra/llcommon/llworkerthread.h b/indra/llcommon/llworkerthread.h
index 9bff18303e..bef5ef53fe 100644
--- a/indra/llcommon/llworkerthread.h
+++ b/indra/llcommon/llworkerthread.h
@@ -94,7 +94,6 @@ public:
 
 private:
 	void deleteWorker(LLWorkerClass* workerclass); // schedule for deletion
-	
 };
 
 //============================================================================
@@ -194,7 +193,7 @@ protected:
 	U32 mRequestPriority; // last priority set
 
 private:
-	LLMutex mMutex;
+	LLMutexRootPool mMutex;		// Use LLMutexRootPool since this object is created and destructed by multiple threads.
 	LLAtomicU32 mWorkFlags;
 };
 
diff --git a/indra/llcommon/tests/llstring_test.cpp b/indra/llcommon/tests/llstring_test.cpp
index 304e91ed92..6a1cbf652a 100644
--- a/indra/llcommon/tests/llstring_test.cpp
+++ b/indra/llcommon/tests/llstring_test.cpp
@@ -624,6 +624,14 @@ namespace tut
 		subcount = LLStringUtil::format(s, fmt_map);
 		ensure_equals("LLStringUtil::format: Assorted Test2 result", s, "?Am I not a long string?short[A]bbbaaaba[A]");
 		ensure_equals("LLStringUtil::format: Assorted Test2 result count", 9, subcount);
+		
+		// Test on nested brackets
+		std::string srcs6 = "[[TRICK1]][[A]][[B]][[AAA]][[BBB]][[TRICK2]][[KEYLONGER]][[KEYSHORTER]]?[[DELETE]]";
+		s = srcs6;
+		subcount = LLStringUtil::format(s, fmt_map);
+		ensure_equals("LLStringUtil::format: Assorted Test2 result", s, "[[A]][a][b][aaa][bbb][[A]][short][Am I not a long string?]?[]");
+		ensure_equals("LLStringUtil::format: Assorted Test2 result count", 9, subcount);
+
 
 		// Test an assorted substitution
 		std::string srcs8 = "foo[DELETE]bar?";