24 files changed, 457 insertions, 726 deletions

diff --git a/indra/llcommon/CMakeLists.txt b/indra/llcommon/CMakeLists.txt
index 42ad56f1b0..af41b9e460 100644
--- a/indra/llcommon/CMakeLists.txt
+++ b/indra/llcommon/CMakeLists.txt
@@ -35,6 +35,7 @@ set(llcommon_SOURCE_FILES
     llapp.cpp
     llapr.cpp
     llassettype.cpp
+    llatomic.cpp
     llbase32.cpp
     llbase64.cpp
     llbitpack.cpp
@@ -135,6 +136,7 @@ set(llcommon_HEADER_FILES
     llapp.h
     llapr.h
     llassettype.h
+    llatomic.h
     llbase32.h
     llbase64.h
     llbitpack.h
diff --git a/indra/llcommon/indra_constants.h b/indra/llcommon/indra_constants.h
index 56b373469a..0fbf4b966b 100644
--- a/indra/llcommon/indra_constants.h
+++ b/indra/llcommon/indra_constants.h
@@ -153,7 +153,6 @@ const U8 SIM_ACCESS_DOWN	= 254;
 const U8 SIM_ACCESS_MAX 	= SIM_ACCESS_ADULT;
 
 // attachment constants
-const S32 MAX_AGENT_ATTACHMENTS = 38;
 const U8  ATTACHMENT_ADD = 0x80;
 
 // god levels
diff --git a/indra/llcommon/llapp.h b/indra/llcommon/llapp.h
index acd829d864..245c73e3a2 100644
--- a/indra/llcommon/llapp.h
+++ b/indra/llcommon/llapp.h
@@ -30,9 +30,8 @@
 #include <map>
 #include "llrun.h"
 #include "llsd.h"
+#include <atomic>
 // Forward declarations
-template <typename Type> class LLAtomic32;
-typedef LLAtomic32<U32> LLAtomicU32;
 class LLErrorThread;
 class LLLiveFile;
 #if LL_LINUX
diff --git a/indra/llcommon/llapr.cpp b/indra/llcommon/llapr.cpp
index d353d06de2..29f0c7da9a 100644
--- a/indra/llcommon/llapr.cpp
+++ b/indra/llcommon/llapr.cpp
@@ -28,13 +28,12 @@
 
 #include "linden_common.h"
 #include "llapr.h"
+#include "llmutex.h"
 #include "apr_dso.h"
 #include "llthreadlocalstorage.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
 
@@ -48,10 +47,6 @@ void ll_init_apr()
 	if (!gAPRPoolp)
 	{
 		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)
@@ -75,23 +70,6 @@ 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;
-	}
-
 	LLThreadLocalPointerBase::destroyAllThreadLocalStorage();
 
 	if (gAPRPoolp)
@@ -168,26 +146,19 @@ apr_pool_t* LLAPRPool::getAPRPool()
 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)
+				  mNumTotalRef(0)
 {
 	//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);
+		mMutexp.reset(new std::mutex());
 	}
 }
 
 LLVolatileAPRPool::~LLVolatileAPRPool()
 {
 	//delete mutex
-	if(mMutexp)
-	{
-		apr_thread_mutex_destroy(mMutexp);
-		apr_pool_destroy(mMutexPool);
-	}
+    mMutexp.reset();
 }
 
 //
@@ -201,7 +172,7 @@ apr_pool_t* LLVolatileAPRPool::getAPRPool()
 
 apr_pool_t* LLVolatileAPRPool::getVolatileAPRPool() 
 {	
-	LLScopedLock lock(mMutexp) ;
+	LLScopedLock lock(mMutexp.get()) ;
 
 	mNumTotalRef++ ;
 	mNumActiveRef++ ;
@@ -216,7 +187,7 @@ apr_pool_t* LLVolatileAPRPool::getVolatileAPRPool()
 
 void LLVolatileAPRPool::clearVolatileAPRPool() 
 {
-	LLScopedLock lock(mMutexp) ;
+    LLScopedLock lock(mMutexp.get());
 
 	if(mNumActiveRef > 0)
 	{
@@ -250,44 +221,6 @@ BOOL LLVolatileAPRPool::isFull()
 {
 	return mNumTotalRef > FULL_VOLATILE_APR_POOL ;
 }
-//---------------------------------------------------------------------
-//
-// LLScopedLock
-//
-LLScopedLock::LLScopedLock(apr_thread_mutex_t* mutex) : mMutex(mutex)
-{
-	if(mutex)
-	{
-		if(ll_apr_warn_status(apr_thread_mutex_lock(mMutex)))
-		{
-			mLocked = false;
-		}
-		else
-		{
-			mLocked = true;
-		}
-	}
-	else
-	{
-		mLocked = false;
-	}
-}
-
-LLScopedLock::~LLScopedLock()
-{
-	unlock();
-}
-
-void LLScopedLock::unlock()
-{
-	if(mLocked)
-	{
-		if(!ll_apr_warn_status(apr_thread_mutex_unlock(mMutex)))
-		{
-			mLocked = false;
-		}
-	}
-}
 
 //---------------------------------------------------------------------
 
diff --git a/indra/llcommon/llapr.h b/indra/llcommon/llapr.h
index 1ac5c4e9b2..da50dda103 100644
--- a/indra/llcommon/llapr.h
+++ b/indra/llcommon/llapr.h
@@ -36,15 +36,22 @@
 #include <boost/noncopyable.hpp>
 #include "llwin32headerslean.h"
 #include "apr_thread_proc.h"
-#include "apr_thread_mutex.h"
 #include "apr_getopt.h"
 #include "apr_signal.h"
-#include "apr_atomic.h"
 
 #include "llstring.h"
 
-extern LL_COMMON_API apr_thread_mutex_t* gLogMutexp;
-extern apr_thread_mutex_t* gCallStacksLogMutexp;
+#if LL_WINDOWS
+#pragma warning (push)
+#pragma warning (disable:4265)
+#endif
+// warning C4265: 'std::_Pad' : class has virtual functions, but destructor is not virtual
+
+#include <mutex>
+
+#if LL_WINDOWS
+#pragma warning (pop)
+#endif
 
 struct apr_dso_handle_t;
 /**
@@ -120,77 +127,9 @@ 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;
+	std::unique_ptr<std::mutex> mMutexp;
 } ;
 
-/** 
- * @class LLScopedLock
- * @brief Small class to help lock and unlock mutexes.
- *
- * This class is used to have a stack level lock once you already have
- * an apr mutex handy. The constructor handles the lock, and the
- * destructor handles the unlock. Instances of this class are
- * <b>not</b> thread safe.
- */
-class LL_COMMON_API LLScopedLock : private boost::noncopyable
-{
-public:
-	/**
-	 * @brief Constructor which accepts a mutex, and locks it.
-	 *
-	 * @param mutex An allocated APR mutex. If you pass in NULL,
-	 * this wrapper will not lock.
-	 */
-	LLScopedLock(apr_thread_mutex_t* mutex);
-
-	/**
-	 * @brief Destructor which unlocks the mutex if still locked.
-	 */
-	~LLScopedLock();
-
-	/** 
-	 * @brief Check lock.
-	 */
-	bool isLocked() const { return mLocked; }
-
-	/** 
-	 * @brief This method unlocks the mutex.
-	 */
-	void unlock();
-
-protected:
-	bool mLocked;
-	apr_thread_mutex_t* mMutex;
-};
-
-template <typename Type> class LLAtomic32
-{
-public:
-	LLAtomic32<Type>() {};
-	LLAtomic32<Type>(Type x) {apr_atomic_set32(&mData, apr_uint32_t(x)); };
-	~LLAtomic32<Type>() {};
-
-	operator const Type() { apr_uint32_t data = apr_atomic_read32(&mData); return Type(data); }
-	
-	Type	CurrentValue() const { apr_uint32_t data = apr_atomic_read32(const_cast< volatile apr_uint32_t* >(&mData)); return Type(data); }
-
-	Type operator =(const Type& x) { apr_atomic_set32(&mData, apr_uint32_t(x)); return Type(mData); }
-	void operator -=(Type x) { apr_atomic_sub32(&mData, apr_uint32_t(x)); }
-	void operator +=(Type x) { apr_atomic_add32(&mData, apr_uint32_t(x)); }
-	Type operator ++(int) { return apr_atomic_inc32(&mData); } // Type++
-	Type operator --(int) { return apr_atomic_dec32(&mData); } // approximately --Type (0 if final is 0, non-zero otherwise)
-
-	Type operator ++() { return apr_atomic_inc32(&mData); } // Type++
-	Type operator --() { return apr_atomic_dec32(&mData); } // approximately --Type (0 if final is 0, non-zero otherwise)
-	
-private:
-	volatile apr_uint32_t mData;
-};
-
-typedef LLAtomic32<U32> LLAtomicU32;
-typedef LLAtomic32<S32> LLAtomicS32;
-
 // File IO convenience functions.
 // Returns NULL if the file fails to open, sets *sizep to file size if not NULL
 // abbreviated flags
diff --git a/indra/llcommon/llatomic.cpp b/indra/llcommon/llatomic.cpp
new file mode 100644
index 0000000000..93aba1f460
--- /dev/null
+++ b/indra/llcommon/llatomic.cpp
@@ -0,0 +1,28 @@
+/** 
+ * @file llatomic.cpp
+ *
+ * $LicenseInfo:firstyear=2018&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2018, 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
+ * $/LicenseInfo$
+ */
+
+#include "llatomic.h"
+
+//============================================================================
diff --git a/indra/llcommon/llatomic.h b/indra/llcommon/llatomic.h
new file mode 100644
index 0000000000..8de773846c
--- /dev/null
+++ b/indra/llcommon/llatomic.h
@@ -0,0 +1,69 @@
+/** 
+ * @file llatomic.h
+ * @brief Base classes for atomic.
+ *
+ * $LicenseInfo:firstyear=2018&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2018, 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_LLATOMIC_H
+#define LL_LLATOMIC_H
+
+#include "stdtypes.h"
+
+#include <atomic>
+
+template <typename Type, typename AtomicType = std::atomic< Type > > class LLAtomicBase
+{
+public:
+    LLAtomicBase() {};
+    LLAtomicBase(Type x) { mData.store(x); }
+    ~LLAtomicBase() {};
+
+    operator const Type() { return mData; }
+
+    Type	CurrentValue() const { return mData; }
+
+    Type operator =(const Type& x) { mData.store(x); return mData; }
+    void operator -=(Type x) { mData -= x; }
+    void operator +=(Type x) { mData += x; }
+    Type operator ++(int) { return mData++; }
+    Type operator --(int) { return mData--; }
+
+    Type operator ++() { return ++mData; }
+    Type operator --() { return --mData; }
+
+private:
+    AtomicType mData;
+};
+
+// Typedefs for specialized versions. Using std::atomic_(u)int32_t to get the optimzed implementation.
+#ifdef LL_WINDOWS
+typedef LLAtomicBase<U32, std::atomic_uint32_t> LLAtomicU32;
+typedef LLAtomicBase<S32, std::atomic_int32_t> LLAtomicS32;
+#else
+typedef LLAtomicBase<U32, std::atomic_uint> LLAtomicU32;
+typedef LLAtomicBase<S32, std::atomic_int> LLAtomicS32;
+#endif
+
+typedef LLAtomicBase<bool, std::atomic_bool> LLAtomicBool;
+
+#endif // LL_LLATOMIC_H
diff --git a/indra/llcommon/llerror.cpp b/indra/llcommon/llerror.cpp
index 7cfd1409b1..335a0995fe 100644
--- a/indra/llcommon/llerror.cpp
+++ b/indra/llcommon/llerror.cpp
@@ -390,15 +390,22 @@ namespace
 
 		{
 			llifstream file(filename().c_str());
-			if (file.is_open())
+			if (!file.is_open())
 			{
-				LLSDSerialize::fromXML(configuration, file);
+				LL_WARNS() << filename() << " failed to open file; not changing configuration" << LL_ENDL;
+				return false;
+			}
+
+			if (LLSDSerialize::fromXML(configuration, file) == LLSDParser::PARSE_FAILURE)
+			{
+				LL_WARNS() << filename() << " parcing error; not changing configuration" << LL_ENDL;
+				return false;
 			}
 
-			if (configuration.isUndefined())
+			if (configuration.isUndefined() || !configuration.isMap() || configuration.emptyMap())
 			{
-				LL_WARNS() << filename() << " missing, ill-formed,"
-							" or simply undefined; not changing configuration"
+				LL_WARNS() << filename() << " missing, ill-formed, or simply undefined"
+							" content; not changing configuration"
 						<< LL_ENDL;
 				return false;
 			}
@@ -860,19 +867,24 @@ namespace LLError
             setEnabledLogTypesMask(config["enabled-log-types-mask"].asInteger());
         }
         
-		LLSD sets = config["settings"];
-		LLSD::array_const_iterator a, end;
-		for (a = sets.beginArray(), end = sets.endArray(); a != end; ++a)
-		{
-			const LLSD& entry = *a;
-			
-			ELevel level = decodeLevel(entry["level"]);
-			
-			setLevels(s->mFunctionLevelMap,	entry["functions"],	level);
-			setLevels(s->mClassLevelMap,	entry["classes"],	level);
-			setLevels(s->mFileLevelMap,		entry["files"],		level);
-			setLevels(s->mTagLevelMap,		entry["tags"],		level);
-		}
+        if (config.has("settings") && config["settings"].isArray())
+        {
+            LLSD sets = config["settings"];
+            LLSD::array_const_iterator a, end;
+            for (a = sets.beginArray(), end = sets.endArray(); a != end; ++a)
+            {
+                const LLSD& entry = *a;
+                if (entry.isMap() && !entry.emptyMap())
+                {
+                    ELevel level = decodeLevel(entry["level"]);
+
+                    setLevels(s->mFunctionLevelMap, entry["functions"], level);
+                    setLevels(s->mClassLevelMap, entry["classes"], level);
+                    setLevels(s->mFileLevelMap, entry["files"], level);
+                    setLevels(s->mTagLevelMap, entry["tags"], level);
+                }
+            }
+        }
 	}
 }
 
@@ -1136,6 +1148,9 @@ namespace
 }
 
 namespace {
+	LLMutex gLogMutex;
+	LLMutex gCallStacksLogMutex;
+
 	bool checkLevelMap(const LevelMap& map, const std::string& key,
 						LLError::ELevel& level)
 	{
@@ -1175,56 +1190,6 @@ namespace {
 		}
 		return found_level;
 	}
-	
-	class LogLock
-	{
-	public:
-		LogLock();
-		~LogLock();
-		bool ok() const { return mOK; }
-	private:
-		bool mLocked;
-		bool mOK;
-	};
-	
-	LogLock::LogLock()
-		: mLocked(false), mOK(false)
-	{
-		if (!gLogMutexp)
-		{
-			mOK = true;
-			return;
-		}
-		
-		const int MAX_RETRIES = 5;
-		for (int attempts = 0; attempts < MAX_RETRIES; ++attempts)
-		{
-			apr_status_t s = apr_thread_mutex_trylock(gLogMutexp);
-			if (!APR_STATUS_IS_EBUSY(s))
-			{
-				mLocked = true;
-				mOK = true;
-				return;
-			}
-
-			ms_sleep(1);
-			//apr_thread_yield();
-				// Just yielding won't necessarily work, I had problems with
-				// this on Linux - doug 12/02/04
-		}
-
-		// We're hosed, we can't get the mutex.  Blah.
-		std::cerr << "LogLock::LogLock: failed to get mutex for log"
-					<< std::endl;
-	}
-	
-	LogLock::~LogLock()
-	{
-		if (mLocked)
-		{
-			apr_thread_mutex_unlock(gLogMutexp);
-		}
-	}
 }
 
 namespace LLError
@@ -1232,8 +1197,8 @@ namespace LLError
 
 	bool Log::shouldLog(CallSite& site)
 	{
-		LogLock lock;
-		if (!lock.ok())
+		LLMutexTrylock lock(&gLogMutex, 5);
+		if (!lock.isLocked())
 		{
 			return false;
 		}
@@ -1283,11 +1248,11 @@ namespace LLError
 
 	std::ostringstream* Log::out()
 	{
-		LogLock lock;
+		LLMutexTrylock lock(&gLogMutex,5);
 		// If we hit a logging request very late during shutdown processing,
 		// when either of the relevant LLSingletons has already been deleted,
 		// DO NOT resurrect them.
-		if (lock.ok() && ! (Settings::wasDeleted() || Globals::wasDeleted()))
+		if (lock.isLocked() && ! (Settings::wasDeleted() || Globals::wasDeleted()))
 		{
 			Globals* g = Globals::getInstance();
 
@@ -1303,8 +1268,8 @@ namespace LLError
 
 	void Log::flush(std::ostringstream* out, char* message)
 	{
-		LogLock lock;
-		if (!lock.ok())
+		LLMutexTrylock lock(&gLogMutex,5);
+		if (!lock.isLocked())
 		{
 			return;
 		}
@@ -1343,8 +1308,8 @@ namespace LLError
 
 	void Log::flush(std::ostringstream* out, const CallSite& site)
 	{
-		LogLock lock;
-		if (!lock.ok())
+		LLMutexTrylock lock(&gLogMutex,5);
+		if (!lock.isLocked())
 		{
 			return;
 		}
@@ -1514,69 +1479,6 @@ namespace LLError
 	char** LLCallStacks::sBuffer = NULL ;
 	S32    LLCallStacks::sIndex  = 0 ;
 
-#define SINGLE_THREADED 1
-
-	class CallStacksLogLock
-	{
-	public:
-		CallStacksLogLock();
-		~CallStacksLogLock();
-
-#if SINGLE_THREADED
-		bool ok() const { return true; }
-#else
-		bool ok() const { return mOK; }
-	private:
-		bool mLocked;
-		bool mOK;
-#endif
-	};
-	
-#if SINGLE_THREADED
-	CallStacksLogLock::CallStacksLogLock()
-	{
-	}
-	CallStacksLogLock::~CallStacksLogLock()
-	{
-	}
-#else
-	CallStacksLogLock::CallStacksLogLock()
-		: mLocked(false), mOK(false)
-	{
-		if (!gCallStacksLogMutexp)
-		{
-			mOK = true;
-			return;
-		}
-		
-		const int MAX_RETRIES = 5;
-		for (int attempts = 0; attempts < MAX_RETRIES; ++attempts)
-		{
-			apr_status_t s = apr_thread_mutex_trylock(gCallStacksLogMutexp);
-			if (!APR_STATUS_IS_EBUSY(s))
-			{
-				mLocked = true;
-				mOK = true;
-				return;
-			}
-
-			ms_sleep(1);
-		}
-
-		// We're hosed, we can't get the mutex.  Blah.
-		std::cerr << "CallStacksLogLock::CallStacksLogLock: failed to get mutex for log"
-					<< std::endl;
-	}
-	
-	CallStacksLogLock::~CallStacksLogLock()
-	{
-		if (mLocked)
-		{
-			apr_thread_mutex_unlock(gCallStacksLogMutexp);
-		}
-	}
-#endif
-
 	//static
    void LLCallStacks::allocateStackBuffer()
    {
@@ -1605,8 +1507,8 @@ namespace LLError
    //static
    void LLCallStacks::push(const char* function, const int line)
    {
-	   CallStacksLogLock lock;
-       if (!lock.ok())
+       LLMutexTrylock lock(&gCallStacksLogMutex, 5);
+       if (!lock.isLocked())
        {
            return;
        }
@@ -1640,8 +1542,8 @@ namespace LLError
    //static
    void LLCallStacks::end(std::ostringstream* _out)
    {
-	   CallStacksLogLock lock;
-       if (!lock.ok())
+       LLMutexTrylock lock(&gCallStacksLogMutex, 5);
+       if (!lock.isLocked())
        {
            return;
        }
@@ -1662,8 +1564,8 @@ namespace LLError
    //static
    void LLCallStacks::print()
    {
-	   CallStacksLogLock lock;
-       if (!lock.ok())
+       LLMutexTrylock lock(&gCallStacksLogMutex, 5);
+       if (!lock.isLocked())
        {
            return;
        }
@@ -1700,8 +1602,8 @@ namespace LLError
 
 bool debugLoggingEnabled(const std::string& tag)
 {
-    LogLock lock;
-    if (!lock.ok())
+    LLMutexTrylock lock(&gLogMutex, 5);
+    if (!lock.isLocked())
     {
         return false;
     }
diff --git a/indra/llcommon/llfixedbuffer.cpp b/indra/llcommon/llfixedbuffer.cpp
index d394f179fb..bd4db8be84 100644
--- a/indra/llcommon/llfixedbuffer.cpp
+++ b/indra/llcommon/llfixedbuffer.cpp
@@ -31,7 +31,7 @@
 LLFixedBuffer::LLFixedBuffer(const U32 max_lines)
 	: LLLineBuffer(),
 	  mMaxLines(max_lines),
-	  mMutex(NULL)
+	  mMutex()
 {
 	mTimer.reset();
 }
diff --git a/indra/llcommon/llinstancetracker.cpp b/indra/llcommon/llinstancetracker.cpp
index 11fc53f8c8..3f990f4869 100644
--- a/indra/llcommon/llinstancetracker.cpp
+++ b/indra/llcommon/llinstancetracker.cpp
@@ -36,17 +36,16 @@
 
 void LLInstanceTrackerBase::StaticBase::incrementDepth()
 {
-	apr_atomic_inc32(&sIterationNestDepth);
+	++sIterationNestDepth;
 }
 
 void LLInstanceTrackerBase::StaticBase::decrementDepth()
 {
 	llassert(sIterationNestDepth);
-	apr_atomic_dec32(&sIterationNestDepth);
+	--sIterationNestDepth;
 }
 
 U32 LLInstanceTrackerBase::StaticBase::getDepth()
 {
-	apr_uint32_t data = apr_atomic_read32(&sIterationNestDepth);
-	return data;
+	return sIterationNestDepth;
 }
diff --git a/indra/llcommon/llinstancetracker.h b/indra/llcommon/llinstancetracker.h
index 910c8dbd99..363d0bcbd5 100644
--- a/indra/llcommon/llinstancetracker.h
+++ b/indra/llcommon/llinstancetracker.h
@@ -28,6 +28,7 @@
 #ifndef LL_LLINSTANCETRACKER_H
 #define LL_LLINSTANCETRACKER_H
 
+#include <atomic>
 #include <map>
 #include <typeinfo>
 
@@ -81,8 +82,12 @@ protected:
 		void decrementDepth();
 		U32 getDepth();
 	private:
-		U32 sIterationNestDepth;
-    };
+#ifdef LL_WINDOWS
+		std::atomic_uint32_t sIterationNestDepth;
+#else
+		std::atomic_uint sIterationNestDepth;
+#endif
+	};
 };
 
 LL_COMMON_API void assert_main_thread();
diff --git a/indra/llcommon/llmutex.cpp b/indra/llcommon/llmutex.cpp
index 9c13ef9e30..75f43a4704 100644
--- a/indra/llcommon/llmutex.cpp
+++ b/indra/llcommon/llmutex.cpp
@@ -24,47 +24,22 @@
  */
 
 #include "linden_common.h"
-#include "llapr.h"
-
-#include "apr_portable.h"
 
 #include "llmutex.h"
 #include "llthread.h"
+#include "lltimer.h"
 
 //============================================================================
 
-LLMutex::LLMutex(apr_pool_t *poolp) :
-	mAPRMutexp(NULL), mCount(0), mLockingThread(NO_THREAD)
+LLMutex::LLMutex() :
+ 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);
 }
 
 
 LLMutex::~LLMutex()
 {
-#if MUTEX_DEBUG
-	//bad assertion, the subclass LLSignal might be "locked", and that's OK
-	//llassert_always(!isLocked()); // better not be locked!
-#endif
-	if (ll_apr_is_initialized())
-	{
-		apr_thread_mutex_destroy(mAPRMutexp);
-		if (mIsLocalPool)
-		{
-			apr_pool_destroy(mAPRPoolp);
-		}
-	}
-	mAPRMutexp = NULL;
 }
 
 
@@ -76,7 +51,7 @@ void LLMutex::lock()
 		return;
 	}
 	
-	apr_thread_mutex_lock(mAPRMutexp);
+	mMutex.lock();
 	
 #if MUTEX_DEBUG
 	// Have to have the lock before we can access the debug info
@@ -106,19 +81,18 @@ void LLMutex::unlock()
 #endif
 
 	mLockingThread = NO_THREAD;
-	apr_thread_mutex_unlock(mAPRMutexp);
+	mMutex.unlock();
 }
 
 bool LLMutex::isLocked()
 {
-	apr_status_t status = apr_thread_mutex_trylock(mAPRMutexp);
-	if (APR_STATUS_IS_EBUSY(status))
+	if (!mMutex.try_lock())
 	{
 		return true;
 	}
 	else
 	{
-		apr_thread_mutex_unlock(mAPRMutexp);
+		mMutex.unlock();
 		return false;
 	}
 }
@@ -141,8 +115,7 @@ bool LLMutex::trylock()
 		return true;
 	}
 	
-	apr_status_t status(apr_thread_mutex_trylock(mAPRMutexp));
-	if (APR_STATUS_IS_EBUSY(status))
+	if (!mMutex.try_lock())
 	{
 		return false;
 	}
@@ -161,45 +134,95 @@ bool LLMutex::trylock()
 
 //============================================================================
 
-LLCondition::LLCondition(apr_pool_t *poolp) :
-	LLMutex(poolp)
+LLCondition::LLCondition() :
+	LLMutex()
 {
-	// base class (LLMutex) has already ensured that mAPRPoolp is set up.
-
-	apr_thread_cond_create(&mAPRCondp, mAPRPoolp);
 }
 
 
 LLCondition::~LLCondition()
 {
-	apr_thread_cond_destroy(mAPRCondp);
-	mAPRCondp = NULL;
 }
 
 
 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);
+	std::unique_lock< std::mutex > lock(mMutex);
+	mCond.wait(lock);
 }
 
 void LLCondition::signal()
 {
-	apr_thread_cond_signal(mAPRCondp);
+	mCond.notify_one();
 }
 
 void LLCondition::broadcast()
 {
-	apr_thread_cond_broadcast(mAPRCondp);
+	mCond.notify_all();
+}
+
+
+
+LLMutexTrylock::LLMutexTrylock(LLMutex* mutex)
+    : mMutex(mutex),
+    mLocked(false)
+{
+    if (mMutex)
+        mLocked = mMutex->trylock();
+}
+
+LLMutexTrylock::LLMutexTrylock(LLMutex* mutex, U32 aTries, U32 delay_ms)
+    : mMutex(mutex),
+    mLocked(false)
+{
+    if (!mMutex)
+        return;
+
+    for (U32 i = 0; i < aTries; ++i)
+    {
+        mLocked = mMutex->trylock();
+        if (mLocked)
+            break;
+        ms_sleep(delay_ms);
+    }
 }
 
+LLMutexTrylock::~LLMutexTrylock()
+{
+    if (mMutex && mLocked)
+        mMutex->unlock();
+}
+
+
+//---------------------------------------------------------------------
+//
+// LLScopedLock
+//
+LLScopedLock::LLScopedLock(std::mutex* mutex) : mMutex(mutex)
+{
+	if(mutex)
+	{
+		mutex->lock();
+		mLocked = true;
+	}
+	else
+	{
+		mLocked = false;
+	}
+}
+
+LLScopedLock::~LLScopedLock()
+{
+	unlock();
+}
+
+void LLScopedLock::unlock()
+{
+	if(mLocked)
+	{
+		mMutex->unlock();
+		mLocked = false;
+	}
+}
 
 //============================================================================
diff --git a/indra/llcommon/llmutex.h b/indra/llcommon/llmutex.h
index ea535cee86..f841d7f950 100644
--- a/indra/llcommon/llmutex.h
+++ b/indra/llcommon/llmutex.h
@@ -28,6 +28,19 @@
 #define LL_LLMUTEX_H
 
 #include "stdtypes.h"
+#include <boost/noncopyable.hpp>
+
+#if LL_WINDOWS
+#pragma warning (push)
+#pragma warning (disable:4265)
+#endif
+// 'std::_Pad' : class has virtual functions, but destructor is not virtual
+#include <mutex>
+#include <condition_variable>
+
+#if LL_WINDOWS
+#pragma warning (pop)
+#endif
 
 //============================================================================
 
@@ -37,10 +50,6 @@
 #include <map>
 #endif
 
-struct apr_thread_mutex_t;
-struct apr_pool_t;
-struct apr_thread_cond_t;
-
 class LL_COMMON_API LLMutex
 {
 public:
@@ -49,7 +58,7 @@ public:
 		NO_THREAD = 0xFFFFFFFF
 	} e_locking_thread;
 
-	LLMutex(apr_pool_t *apr_poolp = NULL); // NULL pool constructs a new pool for the mutex
+	LLMutex();
 	virtual ~LLMutex();
 	
 	void lock();		// blocks
@@ -60,13 +69,10 @@ public:
 	U32 lockingThread() const; //get ID of locking thread
 	
 protected:
-	apr_thread_mutex_t *mAPRMutexp;
+	std::mutex			mMutex;
 	mutable U32			mCount;
 	mutable U32			mLockingThread;
 	
-	apr_pool_t			*mAPRPoolp;
-	BOOL				mIsLocalPool;
-	
 #if MUTEX_DEBUG
 	std::map<U32, BOOL> mIsLocked;
 #endif
@@ -76,7 +82,7 @@ protected:
 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();
 	~LLCondition();
 	
 	void wait();		// blocks
@@ -84,7 +90,7 @@ public:
 	void broadcast();
 	
 protected:
-	apr_thread_cond_t* mAPRCondp;
+	std::condition_variable mCond;
 };
 
 class LLMutexLock
@@ -119,19 +125,9 @@ private:
 class LLMutexTrylock
 {
 public:
-	LLMutexTrylock(LLMutex* mutex)
-		: mMutex(mutex),
-		  mLocked(false)
-	{
-		if (mMutex)
-			mLocked = mMutex->trylock();
-	}
-
-	~LLMutexTrylock()
-	{
-		if (mMutex && mLocked)
-			mMutex->unlock();
-	}
+	LLMutexTrylock(LLMutex* mutex);
+	LLMutexTrylock(LLMutex* mutex, U32 aTries, U32 delay_ms = 10);
+	~LLMutexTrylock();
 
 	bool isLocked() const
 	{
@@ -142,4 +138,43 @@ private:
 	LLMutex*	mMutex;
 	bool		mLocked;
 };
-#endif // LL_LLTHREAD_H
+
+/**
+* @class LLScopedLock
+* @brief Small class to help lock and unlock mutexes.
+*
+* The constructor handles the lock, and the destructor handles
+* the unlock. Instances of this class are <b>not</b> thread safe.
+*/
+class LL_COMMON_API LLScopedLock : private boost::noncopyable
+{
+public:
+    /**
+    * @brief Constructor which accepts a mutex, and locks it.
+    *
+    * @param mutex An allocated mutex. If you pass in NULL,
+    * this wrapper will not lock.
+    */
+    LLScopedLock(std::mutex* mutex);
+
+    /**
+    * @brief Destructor which unlocks the mutex if still locked.
+    */
+    ~LLScopedLock();
+
+    /**
+    * @brief Check lock.
+    */
+    bool isLocked() const { return mLocked; }
+
+    /**
+    * @brief This method unlocks the mutex.
+    */
+    void unlock();
+
+protected:
+    bool mLocked;
+    std::mutex* mMutex;
+};
+
+#endif // LL_LLMUTEX_H
diff --git a/indra/llcommon/llqueuedthread.h b/indra/llcommon/llqueuedthread.h
index d3704b0fe2..5d3f873646 100644
--- a/indra/llcommon/llqueuedthread.h
+++ b/indra/llcommon/llqueuedthread.h
@@ -32,7 +32,7 @@
 #include <map>
 #include <set>
 
-#include "llapr.h"
+#include "llatomic.h"
 
 #include "llthread.h"
 #include "llsimplehash.h"
@@ -128,7 +128,7 @@ public:
 		};
 		
 	protected:
-		LLAtomic32<status_t> mStatus;
+		LLAtomicBase<status_t> mStatus;
 		U32 mPriority;
 		U32 mFlags;
 	};
@@ -198,7 +198,7 @@ public:
 protected:
 	BOOL mThreaded;  // if false, run on main thread and do updates during update()
 	BOOL mStarted;  // required when mThreaded is false to call startThread() from update()
-	LLAtomic32<BOOL> mIdleThread; // request queue is empty (or we are quitting) and the thread is idle
+	LLAtomicBool mIdleThread; // request queue is empty (or we are quitting) and the thread is idle
 	
 	typedef std::set<QueuedRequest*, queued_request_less> request_queue_t;
 	request_queue_t mRequestQueue;
diff --git a/indra/llcommon/llrefcount.cpp b/indra/llcommon/llrefcount.cpp
index a638df2c7c..29a5ca6f24 100644
--- a/indra/llcommon/llrefcount.cpp
+++ b/indra/llcommon/llrefcount.cpp
@@ -29,25 +29,9 @@
 
 #include "llerror.h"
 
-#if LL_REF_COUNT_DEBUG
-#include "llthread.h"
-#include "llapr.h"
-#endif
-
 LLRefCount::LLRefCount(const LLRefCount& other)
 :	mRef(0)
 {
-#if LL_REF_COUNT_DEBUG
-	if(gAPRPoolp)
-	{
-		mMutexp = new LLMutex(gAPRPoolp) ;
-	}
-	else
-	{
-		mMutexp = NULL ;
-	}
-	mCrashAtUnlock = FALSE ;
-#endif
 }
 
 LLRefCount& LLRefCount::operator=(const LLRefCount&)
@@ -59,17 +43,6 @@ LLRefCount& LLRefCount::operator=(const LLRefCount&)
 LLRefCount::LLRefCount() :
 	mRef(0)
 {
-#if LL_REF_COUNT_DEBUG
-	if(gAPRPoolp)
-	{
-		mMutexp = new LLMutex(gAPRPoolp) ;
-	}
-	else
-	{
-		mMutexp = NULL ;
-	}
-	mCrashAtUnlock = FALSE ;
-#endif
 }
 
 LLRefCount::~LLRefCount()
@@ -78,87 +51,5 @@ LLRefCount::~LLRefCount()
 	{
 		LL_ERRS() << "deleting non-zero reference" << LL_ENDL;
 	}
-
-#if LL_REF_COUNT_DEBUG
-	if(gAPRPoolp)
-	{
-		delete mMutexp ;
-	}
-#endif
 }
 
-#if LL_REF_COUNT_DEBUG
-void LLRefCount::ref() const
-{ 
-	if(mMutexp)
-	{
-		if(mMutexp->isLocked()) 
-		{
-			mCrashAtUnlock = TRUE ;
-			LL_ERRS() << "the mutex is locked by the thread: " << mLockedThreadID 
-				<< " Current thread: " << LLThread::currentID() << LL_ENDL ;
-		}
-
-		mMutexp->lock() ;
-		mLockedThreadID = LLThread::currentID() ;
-
-		mRef++; 
-
-		if(mCrashAtUnlock)
-		{
-			while(1); //crash here.
-		}
-		mMutexp->unlock() ;
-	}
-	else
-	{
-		mRef++; 
-	}
-} 
-
-S32 LLRefCount::unref() const
-{
-	if(mMutexp)
-	{
-		if(mMutexp->isLocked()) 
-		{
-			mCrashAtUnlock = TRUE ;
-			LL_ERRS() << "the mutex is locked by the thread: " << mLockedThreadID 
-				<< " Current thread: " << LLThread::currentID() << LL_ENDL ;
-		}
-
-		mMutexp->lock() ;
-		mLockedThreadID = LLThread::currentID() ;
-		
-		llassert(mRef >= 1);
-		if (0 == --mRef) 
-		{
-			if(mCrashAtUnlock)
-			{
-				while(1); //crash here.
-			}
-			mMutexp->unlock() ;
-
-			delete this; 
-			return 0;
-		}
-
-		if(mCrashAtUnlock)
-		{
-			while(1); //crash here.
-		}
-		mMutexp->unlock() ;
-		return mRef;
-	}
-	else
-	{
-		llassert(mRef >= 1);
-		if (0 == --mRef) 
-		{
-			delete this; 
-			return 0;
-		}
-		return mRef;
-	}
-}	
-#endif
diff --git a/indra/llcommon/llrefcount.h b/indra/llcommon/llrefcount.h
index 1107973569..fb0411d27b 100644
--- a/indra/llcommon/llrefcount.h
+++ b/indra/llcommon/llrefcount.h
@@ -29,12 +29,7 @@
 #include <boost/noncopyable.hpp>
 #include <boost/intrusive_ptr.hpp>
 #include "llmutex.h"
-#include "llapr.h"
-
-#define LL_REF_COUNT_DEBUG 0
-#if LL_REF_COUNT_DEBUG
-class LLMutex ;
-#endif
+#include "llatomic.h"
 
 //----------------------------------------------------------------------------
 // RefCount objects should generally only be accessed by way of LLPointer<>'s
@@ -51,10 +46,6 @@ protected:
 public:
 	LLRefCount();
 
-#if LL_REF_COUNT_DEBUG
-	void ref() const ;
-	S32 unref() const ;
-#else
 	inline void ref() const
 	{ 
 		mRef++; 
@@ -69,8 +60,7 @@ public:
 			return 0;
 		}
 		return mRef;
-	}	
-#endif
+	}
 
 	//NOTE: when passing around a const LLRefCount object, this can return different results
 	// at different types, since mRef is mutable
@@ -81,12 +71,6 @@ public:
 
 private: 
 	mutable S32	mRef; 
-
-#if LL_REF_COUNT_DEBUG
-	LLMutex*  mMutexp ;
-	mutable U32  mLockedThreadID ;
-	mutable BOOL mCrashAtUnlock ; 
-#endif
 };
 
 
@@ -123,8 +107,8 @@ public:
 	void unref()
 	{
 		llassert(mRef >= 1);
-		if ((--mRef) == 0)		// See note in llapr.h on atomic decrement operator return value.  
-		{	
+		if ((--mRef) == 0)
+		{
 			// If we hit zero, the caller should be the only smart pointer owning the object and we can delete it.
 			// It is technically possible for a vanilla pointer to mess this up, or another thread to
 			// jump in, find this object, create another smart pointer and end up dangling, but if
@@ -140,7 +124,7 @@ public:
 	}
 
 private: 
-	LLAtomic32< S32	> mRef; 
+	LLAtomicS32 mRef; 
 };
 
 /**
diff --git a/indra/llcommon/llsys.cpp b/indra/llcommon/llsys.cpp
index 1ef6c538ba..1f8d558fbe 100644
--- a/indra/llcommon/llsys.cpp
+++ b/indra/llcommon/llsys.cpp
@@ -268,10 +268,32 @@ LLOSInfo::LLOSInfo() :
 		}
 	}
 
+	S32 ubr = 0; // Windows 10 Update Build Revision, can be retrieved from a registry
+	if (mMajorVer == 10)
+	{
+		DWORD cbData(sizeof(DWORD));
+		DWORD data(0);
+		HKEY key;
+		BOOL ret_code = RegOpenKeyExW(HKEY_LOCAL_MACHINE, TEXT("SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion"), 0, KEY_READ, &key);
+		if (ERROR_SUCCESS == ret_code)
+		{
+			ret_code = RegQueryValueExW(key, L"UBR", 0, NULL, reinterpret_cast<LPBYTE>(&data), &cbData);
+			if (ERROR_SUCCESS == ret_code)
+			{
+				ubr = data;
+			}
+		}
+	}
+
 	mOSString = mOSStringSimple;
 	if (mBuild > 0)
 	{
-		mOSString += llformat("(Build %d)", mBuild);
+		mOSString += llformat("(Build %d", mBuild);
+		if (ubr > 0)
+		{
+			mOSString += llformat(".%d", ubr);
+		}
+		mOSString += ")";
 	}
 
 	LLStringUtil::trim(mOSStringSimple);
diff --git a/indra/llcommon/llthread.cpp b/indra/llcommon/llthread.cpp
index f066e9a4cd..a4171729db 100644
--- a/indra/llcommon/llthread.cpp
+++ b/indra/llcommon/llthread.cpp
@@ -116,29 +116,27 @@ void LLThread::registerThreadID()
 //
 // Handed to the APR thread creation function
 //
-void *APR_THREAD_FUNC LLThread::staticRun(apr_thread_t *apr_threadp, void *datap)
+void LLThread::threadRun()
 {
-    LLThread *threadp = (LLThread *)datap;
-
 #ifdef LL_WINDOWS
-    set_thread_name(-1, threadp->mName.c_str());
+    set_thread_name(-1, mName.c_str());
 #endif
 
     // for now, hard code all LLThreads to report to single master thread recorder, which is known to be running on main thread
-    threadp->mRecorder = new LLTrace::ThreadRecorder(*LLTrace::get_master_thread_recorder());
+    mRecorder = new LLTrace::ThreadRecorder(*LLTrace::get_master_thread_recorder());
 
-    sThreadID = threadp->mID;
+    sThreadID = mID;
 
     // Run the user supplied function
     do 
     {
         try
         {
-            threadp->run();
+            run();
         }
         catch (const LLContinueError &e)
         {
-            LL_WARNS("THREAD") << "ContinueException on thread '" << threadp->mName <<
+            LL_WARNS("THREAD") << "ContinueException on thread '" << mName <<
                 "' reentering run(). Error what is: '" << e.what() << "'" << LL_ENDL;
             //output possible call stacks to log file.
             LLError::LLCallStacks::print();
@@ -153,41 +151,27 @@ void *APR_THREAD_FUNC LLThread::staticRun(apr_thread_t *apr_threadp, void *datap
     //LL_INFOS() << "LLThread::staticRun() Exiting: " << threadp->mName << LL_ENDL;
 
 
-    delete threadp->mRecorder;
-    threadp->mRecorder = NULL;
+    delete mRecorder;
+    mRecorder = NULL;
 
     // We're done with the run function, this thread is done executing now.
     //NB: we are using this flag to sync across threads...we really need memory barriers here
     // Todo: add LLMutex per thread instead of flag?
     // We are using "while (mStatus != STOPPED) {ms_sleep();}" everywhere.
-    threadp->mStatus = STOPPED;
-
-    return NULL;
+    mStatus = STOPPED;
 }
 
 LLThread::LLThread(const std::string& name, apr_pool_t *poolp) :
     mPaused(FALSE),
     mName(name),
-    mAPRThreadp(NULL),
+    mThreadp(NULL),
     mStatus(STOPPED),
     mRecorder(NULL)
 {
 
     mID = ++sIDIter;
-
-    // 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);
-    mDataLock = new LLMutex(mAPRPoolp);
+    mRunCondition = new LLCondition();
+    mDataLock = new LLMutex();
     mLocalAPRFilePoolp = NULL ;
 }
 
@@ -217,7 +201,7 @@ void LLThread::shutdown()
 
     // Warning!  If you somehow call the thread destructor from itself,
     // the thread will die in an unclean fashion!
-    if (mAPRThreadp)
+    if (mThreadp)
     {
         if (!isStopped())
         {
@@ -248,14 +232,19 @@ void LLThread::shutdown()
         {
             // This thread just wouldn't stop, even though we gave it time
             //LL_WARNS() << "LLThread::~LLThread() exiting thread before clean exit!" << LL_ENDL;
-            // Put a stake in its heart.
-            apr_thread_exit(mAPRThreadp, -1);
+            // Put a stake in its heart. (A very hostile method to force a thread to quit)
+#if		LL_WINDOWS
+            TerminateThread(mNativeHandle, 0);
+#else
+            pthread_cancel(mNativeHandle);
+#endif
+
             delete mRecorder;
             mRecorder = NULL;
             mStatus = STOPPED;
             return;
         }
-        mAPRThreadp = NULL;
+        mThreadp = NULL;
     }
 
     delete mRunCondition;
@@ -263,12 +252,6 @@ void LLThread::shutdown()
 
     delete mDataLock;
     mDataLock = NULL;
-    
-    if (mIsLocalPool && mAPRPoolp)
-    {
-        apr_pool_destroy(mAPRPoolp);
-        mAPRPoolp = 0;
-    }
 
     if (mRecorder)
     {
@@ -287,19 +270,15 @@ void LLThread::start()
     // Set thread state to running
     mStatus = RUNNING;
 
-    apr_status_t status =
-        apr_thread_create(&mAPRThreadp, NULL, staticRun, (void *)this, mAPRPoolp);
-    
-    if(status == APR_SUCCESS)
-    {   
-        // We won't bother joining
-        apr_thread_detach(mAPRThreadp);
+    try
+    {
+        mThreadp = new std::thread(std::bind(&LLThread::threadRun, this));
+        mNativeHandle = mThreadp->native_handle();
     }
-    else
+    catch (std::system_error& ex)
     {
         mStatus = STOPPED;
-        LL_WARNS() << "failed to start thread " << mName << LL_ENDL;
-        ll_apr_warn_status(status);
+        LL_WARNS() << "failed to start thread " << mName << " " << ex.what() << LL_ENDL;
     }
 
 }
@@ -376,11 +355,7 @@ U32 LLThread::currentID()
 // static
 void LLThread::yield()
 {
-#if LL_LINUX || LL_SOLARIS
-    sched_yield(); // annoyingly, apr_thread_yield  is a noop on linux...
-#else
-    apr_thread_yield();
-#endif
+    std::this_thread::yield();
 }
 
 void LLThread::wake()
@@ -413,7 +388,7 @@ 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 dda7fa8ffb..863c9051f3 100644
--- a/indra/llcommon/llthread.h
+++ b/indra/llcommon/llthread.h
@@ -29,10 +29,10 @@
 
 #include "llapp.h"
 #include "llapr.h"
-#include "apr_thread_cond.h"
 #include "boost/intrusive_ptr.hpp"
 #include "llmutex.h"
 #include "llrefcount.h"
+#include <thread>
 
 LL_COMMON_API void assert_main_thread();
 
@@ -86,7 +86,6 @@ 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; }
@@ -97,19 +96,18 @@ public:
     static void registerThreadID();
     
 private:
-    BOOL                mPaused;
+    bool                mPaused;
+    std::thread::native_handle_type mNativeHandle; // for termination in case of issues
     
     // static function passed to APR thread creation routine
-    static void *APR_THREAD_FUNC staticRun(struct apr_thread_t *apr_threadp, void *datap);
+    void threadRun();
 
 protected:
     std::string         mName;
     class LLCondition*  mRunCondition;
     LLMutex*            mDataLock;
 
-    apr_thread_t        *mAPRThreadp;
-    apr_pool_t          *mAPRPoolp;
-    BOOL                mIsLocalPool;
+    std::thread        *mThreadp;
     EThreadStatus       mStatus;
     U32                 mID;
     LLTrace::ThreadRecorder* mRecorder;
diff --git a/indra/llcommon/llthreadsafequeue.cpp b/indra/llcommon/llthreadsafequeue.cpp
index 491f920c0f..bde36999ba 100644
--- a/indra/llcommon/llthreadsafequeue.cpp
+++ b/indra/llcommon/llthreadsafequeue.cpp
@@ -24,87 +24,6 @@
  */
 
 #include "linden_common.h"
-#include <apr_pools.h>
-#include <apr_queue.h>
 #include "llthreadsafequeue.h"
-#include "llexception.h"
 
 
-
-// LLThreadSafeQueueImplementation
-//-----------------------------------------------------------------------------
-
-
-LLThreadSafeQueueImplementation::LLThreadSafeQueueImplementation(apr_pool_t * pool, unsigned int capacity):
-	mOwnsPool(pool == 0),
-	mPool(pool),
-	mQueue(0)
-{
-	if(mOwnsPool) {
-		apr_status_t status = apr_pool_create(&mPool, 0);
-		if(status != APR_SUCCESS) LLTHROW(LLThreadSafeQueueError("failed to allocate pool"));
-	} else {
-		; // No op.
-	}
-	
-	apr_status_t status = apr_queue_create(&mQueue, capacity, mPool);
-	if(status != APR_SUCCESS) LLTHROW(LLThreadSafeQueueError("failed to allocate queue"));
-}
-
-
-LLThreadSafeQueueImplementation::~LLThreadSafeQueueImplementation()
-{
-	if(mQueue != 0) {
-		if(apr_queue_size(mQueue) != 0) LL_WARNS() << 
-			"terminating queue which still contains " << apr_queue_size(mQueue) <<
-			" elements;" << "memory will be leaked" << LL_ENDL;
-		apr_queue_term(mQueue);
-	}
-	if(mOwnsPool && (mPool != 0)) apr_pool_destroy(mPool);
-}
-
-
-void LLThreadSafeQueueImplementation::pushFront(void * element)
-{
-	apr_status_t status = apr_queue_push(mQueue, element);
-	
-	if(status == APR_EINTR) {
-		LLTHROW(LLThreadSafeQueueInterrupt());
-	} else if(status != APR_SUCCESS) {
-		LLTHROW(LLThreadSafeQueueError("push failed"));
-	} else {
-		; // Success.
-	}
-}
-
-
-bool LLThreadSafeQueueImplementation::tryPushFront(void * element){
-	return apr_queue_trypush(mQueue, element) == APR_SUCCESS;
-}
-
-
-void * LLThreadSafeQueueImplementation::popBack(void)
-{
-	void * element;
-	apr_status_t status = apr_queue_pop(mQueue, &element);
-
-	if(status == APR_EINTR) {
-		LLTHROW(LLThreadSafeQueueInterrupt());
-	} else if(status != APR_SUCCESS) {
-		LLTHROW(LLThreadSafeQueueError("pop failed"));
-	} else {
-		return element;
-	}
-}
-
-
-bool LLThreadSafeQueueImplementation::tryPopBack(void *& element)
-{
-	return apr_queue_trypop(mQueue, &element) == APR_SUCCESS;
-}
-
-
-size_t LLThreadSafeQueueImplementation::size()
-{
-	return apr_queue_size(mQueue);
-}
diff --git a/indra/llcommon/llthreadsafequeue.h b/indra/llcommon/llthreadsafequeue.h
index 45289ef0b4..b0bddac8e5 100644
--- a/indra/llcommon/llthreadsafequeue.h
+++ b/indra/llcommon/llthreadsafequeue.h
@@ -28,12 +28,20 @@
 #define LL_LLTHREADSAFEQUEUE_H
 
 #include "llexception.h"
+#include <deque>
 #include <string>
 
+#if LL_WINDOWS
+#pragma warning (push)
+#pragma warning (disable:4265)
+#endif
+// 'std::_Pad' : class has virtual functions, but destructor is not virtual
+#include <mutex>
+#include <condition_variable>
 
-struct apr_pool_t; // From apr_pools.h
-class LLThreadSafeQueueImplementation; // See below.
-
+#if LL_WINDOWS
+#pragma warning (pop)
+#endif
 
 //
 // A general queue exception.
@@ -64,31 +72,6 @@ public:
 	}
 };
 
-
-struct apr_queue_t; // From apr_queue.h
-
-
-//
-// Implementation details. 
-//
-class LL_COMMON_API LLThreadSafeQueueImplementation
-{
-public:
-	LLThreadSafeQueueImplementation(apr_pool_t * pool, unsigned int capacity);
-	~LLThreadSafeQueueImplementation();
-	void pushFront(void * element);
-	bool tryPushFront(void * element);
-	void * popBack(void);
-	bool tryPopBack(void *& element);
-	size_t size();
-	
-private:
-	bool mOwnsPool;
-	apr_pool_t * mPool;
-	apr_queue_t * mQueue;
-};
-
-
 //
 // Implements a thread safe FIFO.
 //
@@ -100,7 +83,7 @@ public:
 	
 	// 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);
+	LLThreadSafeQueue(U32 capacity = 1024);
 	
 	// Add an element to the front of queue (will block if the queue has
 	// reached capacity).
@@ -128,77 +111,103 @@ public:
 	size_t size();
 
 private:
-	LLThreadSafeQueueImplementation mImplementation;
-};
-
+	std::deque< ElementT > mStorage;
+	U32 mCapacity;
 
+	std::mutex mLock;
+	std::condition_variable mCapacityCond;
+	std::condition_variable mEmptyCond;
+};
 
 // LLThreadSafeQueue
 //-----------------------------------------------------------------------------
 
-
 template<typename ElementT>
-LLThreadSafeQueue<ElementT>::LLThreadSafeQueue(apr_pool_t * pool, unsigned int capacity):
-	mImplementation(pool, capacity)
+LLThreadSafeQueue<ElementT>::LLThreadSafeQueue(U32 capacity) :
+mCapacity(capacity)
 {
-	; // No op.
 }
 
 
 template<typename ElementT>
 void LLThreadSafeQueue<ElementT>::pushFront(ElementT const & element)
 {
-	ElementT * elementCopy = new ElementT(element);
-	try {
-		mImplementation.pushFront(elementCopy);
-	} catch (LLThreadSafeQueueInterrupt) {
-		delete elementCopy;
-		throw;
-	}
+    while (true)
+    {
+        std::unique_lock<std::mutex> lock1(mLock);
+
+        if (mStorage.size() < mCapacity)
+        {
+            mStorage.push_front(element);
+            mEmptyCond.notify_one();
+            return;
+        }
+
+        // Storage Full. Wait for signal.
+        mCapacityCond.wait(lock1);
+    }
 }
 
 
 template<typename ElementT>
 bool LLThreadSafeQueue<ElementT>::tryPushFront(ElementT const & element)
 {
-	ElementT * elementCopy = new ElementT(element);
-	bool result = mImplementation.tryPushFront(elementCopy);
-	if(!result) delete elementCopy;
-	return result;
+    std::unique_lock<std::mutex> lock1(mLock, std::defer_lock);
+    if (!lock1.try_lock())
+        return false;
+
+    if (mStorage.size() >= mCapacity)
+        return false;
+
+    mStorage.push_front(element);
+    mEmptyCond.notify_one();
+    return true;
 }
 
 
 template<typename ElementT>
 ElementT LLThreadSafeQueue<ElementT>::popBack(void)
 {
-	ElementT * element = reinterpret_cast<ElementT *> (mImplementation.popBack());
-	ElementT result(*element);
-	delete element;
-	return result;
+    while (true)
+    {
+        std::unique_lock<std::mutex> lock1(mLock);
+
+        if (!mStorage.empty())
+        {
+            ElementT value = mStorage.back();
+            mStorage.pop_back();
+            mCapacityCond.notify_one();
+            return value;
+        }
+
+        // Storage empty. Wait for signal.
+        mEmptyCond.wait(lock1);
+    }
 }
 
 
 template<typename ElementT>
 bool LLThreadSafeQueue<ElementT>::tryPopBack(ElementT & element)
 {
-	void * storedElement;
-	bool result = mImplementation.tryPopBack(storedElement);
-	if(result) {
-		ElementT * elementPtr = reinterpret_cast<ElementT *>(storedElement); 
-		element = *elementPtr;
-		delete elementPtr;
-	} else {
-		; // No op.
-	}
-	return result;
+    std::unique_lock<std::mutex> lock1(mLock, std::defer_lock);
+    if (!lock1.try_lock())
+        return false;
+
+    if (mStorage.empty())
+        return false;
+
+    element = mStorage.back();
+    mStorage.pop_back();
+    mCapacityCond.notify_one();
+    return true;
 }
 
 
 template<typename ElementT>
 size_t LLThreadSafeQueue<ElementT>::size(void)
 {
-	return mImplementation.size();
+    std::lock_guard<std::mutex> lock(mLock);
+    return mStorage.size();
 }
 
-
 #endif
diff --git a/indra/llcommon/lluuid.cpp b/indra/llcommon/lluuid.cpp
index d4af2c6b01..8f33d789eb 100644
--- a/indra/llcommon/lluuid.cpp
+++ b/indra/llcommon/lluuid.cpp
@@ -738,7 +738,7 @@ void LLUUID::getCurrentTime(uuid_time_t *timestamp)
       getSystemTime(&time_last);
       uuids_this_tick = uuids_per_tick;
       init = TRUE;
-	  mMutex = new LLMutex(NULL);
+	  mMutex = new LLMutex();
    }
 
    uuid_time_t time_now = {0,0};
diff --git a/indra/llcommon/llworkerthread.cpp b/indra/llcommon/llworkerthread.cpp
index 4c197dc1d6..4b91b2caca 100644
--- a/indra/llcommon/llworkerthread.cpp
+++ b/indra/llcommon/llworkerthread.cpp
@@ -37,7 +37,7 @@
 LLWorkerThread::LLWorkerThread(const std::string& name, bool threaded, bool should_pause) :
 	LLQueuedThread(name, threaded, should_pause)
 {
-	mDeleteMutex = new LLMutex(NULL);
+	mDeleteMutex = new LLMutex();
 
 	if(!mLocalAPRFilePoolp)
 	{
@@ -204,7 +204,7 @@ LLWorkerClass::LLWorkerClass(LLWorkerThread* workerthread, const std::string& na
 	  mWorkerClassName(name),
 	  mRequestHandle(LLWorkerThread::nullHandle()),
 	  mRequestPriority(LLWorkerThread::PRIORITY_NORMAL),
-	  mMutex(NULL),
+	  mMutex(),
 	  mWorkFlags(0)
 {
 	if (!mWorkerThread)
diff --git a/indra/llcommon/llworkerthread.h b/indra/llcommon/llworkerthread.h
index 09776816a8..b1a6f61360 100644
--- a/indra/llcommon/llworkerthread.h
+++ b/indra/llcommon/llworkerthread.h
@@ -33,7 +33,7 @@
 #include <string>
 
 #include "llqueuedthread.h"
-#include "llapr.h"
+#include "llatomic.h"
 
 #define USE_FRAME_CALLBACK_MANAGER 0