Automated merge with ssh://bitbucket.org/lindenlab/viewer-release

52 files changed, 900 insertions, 446 deletions

diff --git a/indra/linux_crash_logger/linux_crash_logger.cpp b/indra/linux_crash_logger/linux_crash_logger.cpp
index 9d5ec33fed..63e5409876 100644
--- a/indra/linux_crash_logger/linux_crash_logger.cpp
+++ b/indra/linux_crash_logger/linux_crash_logger.cpp
@@ -51,7 +51,7 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	app.mainLoop();
+	app.frame();
 	app.cleanup();
 	LL_INFOS() << "Crash reporter finished normally." << LL_ENDL;
 	return 0;
diff --git a/indra/linux_crash_logger/llcrashloggerlinux.cpp b/indra/linux_crash_logger/llcrashloggerlinux.cpp
index e2d2e7ff26..4092d43fc5 100644
--- a/indra/linux_crash_logger/llcrashloggerlinux.cpp
+++ b/indra/linux_crash_logger/llcrashloggerlinux.cpp
@@ -114,7 +114,7 @@ void LLCrashLoggerLinux::gatherPlatformSpecificFiles()
 {
 }
 
-bool LLCrashLoggerLinux::mainLoop()
+bool LLCrashLoggerLinux::frame()
 {
 	bool send_logs = true;
 	if(CRASH_BEHAVIOR_ASK == getCrashBehavior())
diff --git a/indra/linux_crash_logger/llcrashloggerlinux.h b/indra/linux_crash_logger/llcrashloggerlinux.h
index dae6c46651..789f6f03f5 100644
--- a/indra/linux_crash_logger/llcrashloggerlinux.h
+++ b/indra/linux_crash_logger/llcrashloggerlinux.h
@@ -36,7 +36,7 @@ class LLCrashLoggerLinux : public LLCrashLogger
 public:
 	LLCrashLoggerLinux(void);
 	~LLCrashLoggerLinux(void);
-	virtual bool mainLoop();
+	virtual bool frame();
 	virtual void updateApplication(const std::string& = LLStringUtil::null);
 	virtual void gatherPlatformSpecificFiles();
 	virtual bool cleanup();
diff --git a/indra/llcommon/CMakeLists.txt b/indra/llcommon/CMakeLists.txt
index 907dbab8f8..410a5819b3 100644
--- a/indra/llcommon/CMakeLists.txt
+++ b/indra/llcommon/CMakeLists.txt
@@ -58,6 +58,7 @@ set(llcommon_SOURCE_FILES
     lleventfilter.cpp
     llevents.cpp
     lleventtimer.cpp
+    llexception.cpp
     llfasttimer.cpp
     llfile.cpp
     llfindlocale.cpp
@@ -157,6 +158,7 @@ set(llcommon_HEADER_FILES
     lleventfilter.h
     llevents.h
     lleventemitter.h
+    llexception.h
     llfasttimer.h
     llfile.h
     llfindlocale.h
@@ -315,7 +317,7 @@ if (LL_TESTS)
   LL_ADD_INTEGRATION_TEST(llprocinfo "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(llrand "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(llsdserialize "" "${test_libs}")
-  LL_ADD_INTEGRATION_TEST(llsingleton "" "${test_libs}")                          
+  LL_ADD_INTEGRATION_TEST(llsingleton "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(llstring "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(lltrace "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(lltreeiterators "" "${test_libs}")
@@ -328,6 +330,11 @@ if (LL_TESTS)
   LL_ADD_INTEGRATION_TEST(llleap "" "${test_libs}")
   LL_ADD_INTEGRATION_TEST(llstreamqueue "" "${test_libs}")
 
+## llexception_test.cpp isn't a regression test, and doesn't need to be run
+## every build. It's to help a developer make implementation choices about
+## throwing and catching exceptions.
+##LL_ADD_INTEGRATION_TEST(llexception "" "${test_libs}")
+
   # *TODO - reenable these once tcmalloc libs no longer break the build.
   #ADD_BUILD_TEST(llallocator llcommon)
   #ADD_BUILD_TEST(llallocator_heap_profile llcommon)
diff --git a/indra/llcommon/llapp.h b/indra/llcommon/llapp.h
index d9933b3d36..ff9a92b45f 100644
--- a/indra/llcommon/llapp.h
+++ b/indra/llcommon/llapp.h
@@ -172,12 +172,12 @@ public:
 	virtual bool cleanup() = 0;			// Override to do application cleanup
 
 	//
-	// mainLoop()
+	// frame()
 	//
-	// Runs the application main loop.  It's assumed that when you exit
-	// this method, the application is in one of the cleanup states, either QUITTING or ERROR
+	// Pass control to the application for a single frame. Returns 'done'
+	// flag: if frame() returns false, it expects to be called again.
 	//
-	virtual bool mainLoop() = 0; // Override for the application main loop.  Needs to at least gracefully notice the QUITTING state and exit.
+	virtual bool frame() = 0; // Override for application body logic
 
 	//
 	// Crash logging
diff --git a/indra/llcommon/lldependencies.cpp b/indra/llcommon/lldependencies.cpp
index 0e72c175cb..0d5757effd 100644
--- a/indra/llcommon/lldependencies.cpp
+++ b/indra/llcommon/lldependencies.cpp
@@ -40,6 +40,7 @@
 #include <boost/graph/topological_sort.hpp>
 #include <boost/graph/exception.hpp>
 // other Linden headers
+#include "llexception.h"
 
 LLDependenciesBase::VertexList LLDependenciesBase::topo_sort(int vertices, const EdgeList& edges) const
 {
@@ -76,7 +77,7 @@ LLDependenciesBase::VertexList LLDependenciesBase::topo_sort(int vertices, const
         // Omit independent nodes: display only those that might contribute to
         // the cycle.
         describe(out, false);
-        throw Cycle(out.str());
+        LLTHROW(Cycle(out.str()));
     }
     // A peculiarity of boost::topological_sort() is that it emits results in
     // REVERSE topological order: to get the result you want, you must
diff --git a/indra/llcommon/lldependencies.h b/indra/llcommon/lldependencies.h
index e0294e271b..125bd6a835 100644
--- a/indra/llcommon/lldependencies.h
+++ b/indra/llcommon/lldependencies.h
@@ -34,13 +34,13 @@
 #include <vector>
 #include <set>
 #include <map>
-#include <stdexcept>
 #include <iosfwd>
 #include <boost/iterator/transform_iterator.hpp>
 #include <boost/iterator/indirect_iterator.hpp>
 #include <boost/range/iterator_range.hpp>
 #include <boost/function.hpp>
 #include <boost/bind.hpp>
+#include "llexception.h"
 
 /*****************************************************************************
 *   Utilities
@@ -106,9 +106,9 @@ public:
     /**
      * Exception thrown by sort() if there's a cycle
      */
-    struct Cycle: public std::runtime_error
+    struct Cycle: public LLException
     {
-        Cycle(const std::string& what): std::runtime_error(what) {}
+        Cycle(const std::string& what): LLException(what) {}
     };
 
     /**
diff --git a/indra/llcommon/lleventcoro.cpp b/indra/llcommon/lleventcoro.cpp
index 2d5f964deb..56367b8f54 100644
--- a/indra/llcommon/lleventcoro.cpp
+++ b/indra/llcommon/lleventcoro.cpp
@@ -39,6 +39,7 @@
 #include "llerror.h"
 #include "llcoros.h"
 #include "llmake.h"
+#include "llexception.h"
 
 #include "lleventfilter.h"
 
@@ -351,7 +352,7 @@ LLSD errorException(const LLEventWithID& result, const std::string& desc)
     // returning it, deliver it via exception.
     if (result.second)
     {
-        throw LLErrorEvent(desc, result.first);
+        LLTHROW(LLErrorEvent(desc, result.first));
     }
     // That way, our caller knows a simple return must be from the reply
     // pump (pump 0).
diff --git a/indra/llcommon/lleventcoro.h b/indra/llcommon/lleventcoro.h
index 87926c692d..84827aab4a 100644
--- a/indra/llcommon/lleventcoro.h
+++ b/indra/llcommon/lleventcoro.h
@@ -31,10 +31,10 @@
 
 #include <boost/optional.hpp>
 #include <string>
-#include <stdexcept>
 #include <utility>                  // std::pair
 #include "llevents.h"
 #include "llerror.h"
+#include "llexception.h"
 
 /**
  * Like LLListenerOrPumpName, this is a class intended for parameter lists:
@@ -234,11 +234,11 @@ LLSD errorException(const LLEventWithID& result, const std::string& desc);
  * because it's not an error in event processing: rather, this exception
  * announces an event that bears error information (for some other API).
  */
-class LL_COMMON_API LLErrorEvent: public std::runtime_error
+class LL_COMMON_API LLErrorEvent: public LLException
 {
 public:
     LLErrorEvent(const std::string& what, const LLSD& data):
-        std::runtime_error(what),
+        LLException(what),
         mData(data)
     {}
     virtual ~LLErrorEvent() throw() {}
diff --git a/indra/llcommon/llevents.cpp b/indra/llcommon/llevents.cpp
index 645c29d770..19d700a3b0 100644
--- a/indra/llcommon/llevents.cpp
+++ b/indra/llcommon/llevents.cpp
@@ -57,6 +57,7 @@
 #include "stringize.h"
 #include "llerror.h"
 #include "llsdutil.h"
+#include "llexception.h"
 #if LL_MSVC
 #pragma warning (disable : 4702)
 #endif
@@ -174,7 +175,7 @@ std::string LLEventPumps::registerNew(const LLEventPump& pump, const std::string
     // Unless we're permitted to tweak it, that's Bad.
     if (! tweak)
     {
-        throw LLEventPump::DupPumpName(std::string("Duplicate LLEventPump name '") + name + "'");
+        LLTHROW(LLEventPump::DupPumpName("Duplicate LLEventPump name '" + name + "'"));
     }
     // The passed name isn't unique, but we're permitted to tweak it. Find the
     // first decimal-integer suffix not already taken. The insert() attempt
@@ -326,8 +327,8 @@ LLBoundListener LLEventPump::listen_impl(const std::string& name, const LLEventL
     // is only when the existing connection object is still connected.
     if (found != mConnections.end() && found->second.connected())
     {
-        throw DupListenerName(std::string("Attempt to register duplicate listener name '") + name +
-                              "' on " + typeid(*this).name() + " '" + getName() + "'");
+        LLTHROW(DupListenerName("Attempt to register duplicate listener name '" + name +
+                                "' on " + typeid(*this).name() + " '" + getName() + "'"));
     }
     // Okay, name is unique, try to reconcile its dependencies. Specify a new
     // "node" value that we never use for an mSignal placement; we'll fix it
@@ -353,8 +354,8 @@ LLBoundListener LLEventPump::listen_impl(const std::string& name, const LLEventL
         // unsortable. If we leave the new node in mDeps, it will continue
         // to screw up all future attempts to sort()! Pull it out.
         mDeps.remove(name);
-        throw Cycle(std::string("New listener '") + name + "' on " + typeid(*this).name() +
-                    " '" + getName() + "' would cause cycle: " + e.what());
+        LLTHROW(Cycle("New listener '" + name + "' on " + typeid(*this).name() +
+                      " '" + getName() + "' would cause cycle: " + e.what()));
     }
     // Walk the list to verify that we haven't changed the order.
     float previous = 0.0, myprev = 0.0;
@@ -418,7 +419,7 @@ LLBoundListener LLEventPump::listen_impl(const std::string& name, const LLEventL
             // NOW remove the offending listener node.
             mDeps.remove(name);
             // Having constructed a description of the order change, inform caller.
-            throw OrderChange(out.str());
+            LLTHROW(OrderChange(out.str()));
         }
         // This node becomes the previous one.
         previous = dmi->second;
@@ -608,7 +609,7 @@ bool LLListenerOrPumpName::operator()(const LLSD& event) const
 {
     if (! mListener)
     {
-        throw Empty("attempting to call uninitialized");
+        LLTHROW(Empty("attempting to call uninitialized"));
     }
     return (*mListener)(event);
 }
diff --git a/indra/llcommon/llevents.h b/indra/llcommon/llevents.h
index ba4fcd766e..8ff337911d 100644
--- a/indra/llcommon/llevents.h
+++ b/indra/llcommon/llevents.h
@@ -37,7 +37,6 @@
 #include <set>
 #include <vector>
 #include <deque>
-#include <stdexcept>
 #if LL_WINDOWS
 	#pragma warning (push)
 	#pragma warning (disable : 4263) // boost::signals2::expired_slot::what() has const mismatch
@@ -62,6 +61,7 @@
 #include "llsingleton.h"
 #include "lldependencies.h"
 #include "llstl.h"
+#include "llexception.h"
 
 /*==========================================================================*|
 // override this to allow binding free functions with more parameters
@@ -188,10 +188,10 @@ public:
     bool operator()(const LLSD& event) const;
 
     /// exception if you try to call when empty
-    struct Empty: public std::runtime_error
+    struct Empty: public LLException
     {
         Empty(const std::string& what):
-            std::runtime_error(std::string("LLListenerOrPumpName::Empty: ") + what) {}
+            LLException(std::string("LLListenerOrPumpName::Empty: ") + what) {}
     };
 
 private:
@@ -371,10 +371,10 @@ public:
      * you didn't pass <tt>tweak=true</tt> to permit it to generate a unique
      * variant.
      */
-    struct DupPumpName: public std::runtime_error
+    struct DupPumpName: public LLException
     {
         DupPumpName(const std::string& what):
-            std::runtime_error(std::string("DupPumpName: ") + what) {}
+            LLException(std::string("DupPumpName: ") + what) {}
     };
 
     /**
@@ -399,9 +399,9 @@ public:
     /// group exceptions thrown by listen(). We use exceptions because these
     /// particular errors are likely to be coding errors, found and fixed by
     /// the developer even before preliminary checkin.
-    struct ListenError: public std::runtime_error
+    struct ListenError: public LLException
     {
-        ListenError(const std::string& what): std::runtime_error(what) {}
+        ListenError(const std::string& what): LLException(what) {}
     };
     /**
      * exception thrown by listen(). You are attempting to register a
diff --git a/indra/llcommon/llexception.cpp b/indra/llcommon/llexception.cpp
new file mode 100644
index 0000000000..f48509b2aa
--- /dev/null
+++ b/indra/llcommon/llexception.cpp
@@ -0,0 +1,41 @@
+/**
+ * @file   llexception.cpp
+ * @author Nat Goodspeed
+ * @date   2016-08-12
+ * @brief  Implementation for llexception.
+ * 
+ * $LicenseInfo:firstyear=2016&license=viewerlgpl$
+ * Copyright (c) 2016, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "linden_common.h"
+// associated header
+#include "llexception.h"
+// STL headers
+// std headers
+#include <typeinfo>
+// external library headers
+#include <boost/exception/diagnostic_information.hpp>
+// other Linden headers
+#include "llerror.h"
+
+void crash_on_unhandled_exception_(const char* file, int line, const char* pretty_function)
+{
+    // LL_ERRS() terminates, but also propagates message into crash dump.
+    LL_ERRS() << file << "(" << line << "): Unhandled exception caught in " << pretty_function
+              << ":\n" << boost::current_exception_diagnostic_information() << LL_ENDL;
+}
+
+void log_unhandled_exception_(const char* file, int line, const char* pretty_function,
+                             const LLContinueError& e)
+{
+    // Use LL_WARNS() because we seriously do not expect this to happen
+    // routinely, but we DO expect to return from this function. Deriving your
+    // exception from LLContinueError implies that such an exception should
+    // NOT be fatal to the viewer, only to its current task.
+    LL_WARNS() << file << "(" << line << "): Unhandled " << typeid(e).name()
+               << " exception caught in " << pretty_function
+               << ":\n" << boost::current_exception_diagnostic_information() << LL_ENDL;
+}
diff --git a/indra/llcommon/llexception.h b/indra/llcommon/llexception.h
new file mode 100644
index 0000000000..e9e25ae689
--- /dev/null
+++ b/indra/llcommon/llexception.h
@@ -0,0 +1,82 @@
+/**
+ * @file   llexception.h
+ * @author Nat Goodspeed
+ * @date   2016-06-29
+ * @brief  Types needed for generic exception handling
+ * 
+ * $LicenseInfo:firstyear=2016&license=viewerlgpl$
+ * Copyright (c) 2016, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+#if ! defined(LL_LLEXCEPTION_H)
+#define LL_LLEXCEPTION_H
+
+#include <stdexcept>
+#include <boost/exception/exception.hpp>
+#include <boost/throw_exception.hpp>
+
+// "Found someone who can comfort me
+//  But there are always exceptions..."
+//  - Empty Pages, Traffic, from John Barleycorn (1970)
+//    https://www.youtube.com/watch?v=dRH0CGVK7ic
+
+/**
+ * LLException is intended as the common base class from which all
+ * viewer-specific exceptions are derived. Rationale for why it's derived from
+ * both std::exception and boost::exception is explained in
+ * tests/llexception_test.cpp.
+ *
+ * boost::current_exception_diagnostic_information() is quite wonderful: if
+ * all we need to do with an exception is log it, in most places we should
+ * catch (...) and log boost::current_exception_diagnostic_information().
+ *
+ * There may be circumstances in which it would be valuable to distinguish an
+ * exception explicitly thrown by viewer code from an exception thrown by
+ * (say) a third-party library. Catching (const LLException&) supports such
+ * usage. However, most of the value of this base class is in the
+ * diagnostic_information() available via Boost.Exception.
+ */
+struct LLException:
+    public std::runtime_error,
+    public boost::exception
+{
+    LLException(const std::string& what):
+        std::runtime_error(what)
+    {}
+};
+
+/**
+ * The point of LLContinueError is to distinguish exceptions that need not
+ * terminate the whole viewer session. In general, an uncaught exception will
+ * be logged and will crash the viewer. However, though an uncaught exception
+ * derived from LLContinueError will still be logged, the viewer will attempt
+ * to continue processing.
+ */
+struct LLContinueError: public LLException
+{
+    LLContinueError(const std::string& what):
+        LLException(what)
+    {}
+};
+
+/**
+ * Please use LLTHROW() to throw viewer exceptions whenever possible. This
+ * enriches the exception's diagnostic_information() with the source file,
+ * line and containing function of the LLTHROW() macro.
+ */
+// Currently we implement that using BOOST_THROW_EXCEPTION(). Wrap it in
+// LLTHROW() in case we ever want to revisit that implementation decision.
+#define LLTHROW(x) BOOST_THROW_EXCEPTION(x)
+
+/// Call this macro from a catch (...) clause
+#define CRASH_ON_UNHANDLED_EXCEPTION() \
+     crash_on_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__)
+void crash_on_unhandled_exception_(const char*, int, const char*);
+
+/// Call this from a catch (const LLContinueError&) clause
+#define LOG_UNHANDLED_EXCEPTION(EXC) \
+     log_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__, EXC)
+void log_unhandled_exception_(const char*, int, const char*, const LLContinueError&);
+
+#endif /* ! defined(LL_LLEXCEPTION_H) */
diff --git a/indra/llcommon/llleap.cpp b/indra/llcommon/llleap.cpp
index 84d2a12f65..c87d2a3e58 100644
--- a/indra/llcommon/llleap.cpp
+++ b/indra/llcommon/llleap.cpp
@@ -33,6 +33,7 @@
 #include "lltimer.h"
 #include "lluuid.h"
 #include "llleaplistener.h"
+#include "llexception.h"
 
 #if LL_MSVC
 #pragma warning (disable : 4355) // 'this' used in initializer list: yes, intentionally
@@ -69,7 +70,7 @@ public:
         // Rule out empty vector
         if (plugin.empty())
         {
-            throw Error("no plugin command");
+            LLTHROW(Error("no plugin command"));
         }
 
         // Don't leave desc empty either, but in this case, if we weren't
@@ -112,7 +113,7 @@ public:
         // If that didn't work, no point in keeping this LLLeap object.
         if (! mChild)
         {
-            throw Error(STRINGIZE("failed to run " << mDesc));
+            LLTHROW(Error(STRINGIZE("failed to run " << mDesc)));
         }
 
         // Okay, launch apparently worked. Change our mDonePump listener.
diff --git a/indra/llcommon/llleap.h b/indra/llcommon/llleap.h
index e33f25e530..8aac8a64c5 100644
--- a/indra/llcommon/llleap.h
+++ b/indra/llcommon/llleap.h
@@ -13,9 +13,9 @@
 #define LL_LLLEAP_H
 
 #include "llinstancetracker.h"
+#include "llexception.h"
 #include <string>
 #include <vector>
-#include <stdexcept>
 
 /**
  * LLSD Event API Plugin class. Because instances are managed by
@@ -67,9 +67,9 @@ public:
      * string(s) passed to create() might come from an external source. This
      * way the caller can catch LLLeap::Error and try to recover.
      */
-    struct Error: public std::runtime_error
+    struct Error: public LLException
     {
-        Error(const std::string& what): std::runtime_error(what) {}
+        Error(const std::string& what): LLException(what) {}
     };
 
     virtual ~LLLeap();
diff --git a/indra/llcommon/llprocess.cpp b/indra/llcommon/llprocess.cpp
index 44f56daf2d..8c321d06b9 100644
--- a/indra/llcommon/llprocess.cpp
+++ b/indra/llcommon/llprocess.cpp
@@ -34,6 +34,7 @@
 #include "llapr.h"
 #include "apr_signal.h"
 #include "llevents.h"
+#include "llexception.h"
 
 #include <boost/foreach.hpp>
 #include <boost/bind.hpp>
@@ -472,9 +473,9 @@ private:
 *****************************************************************************/
 /// Need an exception to avoid constructing an invalid LLProcess object, but
 /// internal use only
-struct LLProcessError: public std::runtime_error
+struct LLProcessError: public LLException
 {
-	LLProcessError(const std::string& msg): std::runtime_error(msg) {}
+	LLProcessError(const std::string& msg): LLException(msg) {}
 };
 
 LLProcessPtr LLProcess::create(const LLSDOrParams& params)
@@ -530,8 +531,8 @@ LLProcess::LLProcess(const LLSDOrParams& params):
 
 	if (! params.validateBlock(true))
 	{
-		throw LLProcessError(STRINGIZE("not launched: failed parameter validation\n"
-									   << LLSDNotationStreamer(params)));
+		LLTHROW(LLProcessError(STRINGIZE("not launched: failed parameter validation\n"
+										 << LLSDNotationStreamer(params))));
 	}
 
 	mPostend = params.postend;
@@ -596,10 +597,10 @@ LLProcess::LLProcess(const LLSDOrParams& params):
 		}
 		else
 		{
-			throw LLProcessError(STRINGIZE("For " << params.executable()
-										   << ": unsupported FileParam for " << which
-										   << ": type='" << fparam.type()
-										   << "', name='" << fparam.name() << "'"));
+			LLTHROW(LLProcessError(STRINGIZE("For " << params.executable()
+											 << ": unsupported FileParam for " << which
+											 << ": type='" << fparam.type()
+											 << "', name='" << fparam.name() << "'")));
 		}
 	}
 	// By default, pass APR_NO_PIPE for unspecified slots.
@@ -678,7 +679,7 @@ LLProcess::LLProcess(const LLSDOrParams& params):
 	if (ll_apr_warn_status(apr_proc_create(&mProcess, argv[0], &argv[0], NULL, procattr,
 										   gAPRPoolp)))
 	{
-		throw LLProcessError(STRINGIZE(params << " failed"));
+		LLTHROW(LLProcessError(STRINGIZE(params << " failed")));
 	}
 
 	// arrange to call status_callback()
@@ -1063,7 +1064,7 @@ PIPETYPE& LLProcess::getPipe(FILESLOT slot)
 	PIPETYPE* wp = getPipePtr<PIPETYPE>(error, slot);
 	if (! wp)
 	{
-		throw NoPipe(error);
+		LLTHROW(NoPipe(error));
 	}
 	return *wp;
 }
diff --git a/indra/llcommon/llprocess.h b/indra/llcommon/llprocess.h
index 43ccadc412..bfac4567a5 100644
--- a/indra/llcommon/llprocess.h
+++ b/indra/llcommon/llprocess.h
@@ -30,13 +30,13 @@
 #include "llinitparam.h"
 #include "llsdparam.h"
 #include "llwin32headerslean.h"
+#include "llexception.h"
 #include "apr_thread_proc.h"
 #include <boost/shared_ptr.hpp>
 #include <boost/ptr_container/ptr_vector.hpp>
 #include <boost/optional.hpp>
 #include <boost/noncopyable.hpp>
 #include <iosfwd>                   // std::ostream
-#include <stdexcept>
 
 #if LL_WINDOWS
 #include "llwin32headerslean.h"	// for HANDLE
@@ -479,9 +479,9 @@ public:
 
 	/// Exception thrown by getWritePipe(), getReadPipe() if you didn't ask to
 	/// create a pipe at the corresponding FILESLOT.
-	struct NoPipe: public std::runtime_error
+	struct NoPipe: public LLException
 	{
-		NoPipe(const std::string& what): std::runtime_error(what) {}
+		NoPipe(const std::string& what): LLException(what) {}
 	};
 
 	/**
diff --git a/indra/llcommon/llthreadsafequeue.cpp b/indra/llcommon/llthreadsafequeue.cpp
index 185f0d63fb..491f920c0f 100644
--- a/indra/llcommon/llthreadsafequeue.cpp
+++ b/indra/llcommon/llthreadsafequeue.cpp
@@ -27,6 +27,7 @@
 #include <apr_pools.h>
 #include <apr_queue.h>
 #include "llthreadsafequeue.h"
+#include "llexception.h"
 
 
 
@@ -41,13 +42,13 @@ LLThreadSafeQueueImplementation::LLThreadSafeQueueImplementation(apr_pool_t * po
 {
 	if(mOwnsPool) {
 		apr_status_t status = apr_pool_create(&mPool, 0);
-		if(status != APR_SUCCESS) throw LLThreadSafeQueueError("failed to allocate pool");
+		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) throw LLThreadSafeQueueError("failed to allocate queue");
+	if(status != APR_SUCCESS) LLTHROW(LLThreadSafeQueueError("failed to allocate queue"));
 }
 
 
@@ -68,9 +69,9 @@ void LLThreadSafeQueueImplementation::pushFront(void * element)
 	apr_status_t status = apr_queue_push(mQueue, element);
 	
 	if(status == APR_EINTR) {
-		throw LLThreadSafeQueueInterrupt();
+		LLTHROW(LLThreadSafeQueueInterrupt());
 	} else if(status != APR_SUCCESS) {
-		throw LLThreadSafeQueueError("push failed");
+		LLTHROW(LLThreadSafeQueueError("push failed"));
 	} else {
 		; // Success.
 	}
@@ -88,9 +89,9 @@ void * LLThreadSafeQueueImplementation::popBack(void)
 	apr_status_t status = apr_queue_pop(mQueue, &element);
 
 	if(status == APR_EINTR) {
-		throw LLThreadSafeQueueInterrupt();
+		LLTHROW(LLThreadSafeQueueInterrupt());
 	} else if(status != APR_SUCCESS) {
-		throw LLThreadSafeQueueError("pop failed");
+		LLTHROW(LLThreadSafeQueueError("pop failed"));
 	} else {
 		return element;
 	}
diff --git a/indra/llcommon/llthreadsafequeue.h b/indra/llcommon/llthreadsafequeue.h
index 58cac38769..45289ef0b4 100644
--- a/indra/llcommon/llthreadsafequeue.h
+++ b/indra/llcommon/llthreadsafequeue.h
@@ -27,9 +27,8 @@
 #ifndef LL_LLTHREADSAFEQUEUE_H
 #define LL_LLTHREADSAFEQUEUE_H
 
-
+#include "llexception.h"
 #include <string>
-#include <stdexcept>
 
 
 struct apr_pool_t; // From apr_pools.h
@@ -40,11 +39,11 @@ class LLThreadSafeQueueImplementation; // See below.
 // A general queue exception.
 //
 class LL_COMMON_API LLThreadSafeQueueError:
-public std::runtime_error
+	public LLException
 {
 public:
 	LLThreadSafeQueueError(std::string const & message):
-	std::runtime_error(message)
+		LLException(message)
 	{
 		; // No op.
 	}
diff --git a/indra/llcommon/lluuid.cpp b/indra/llcommon/lluuid.cpp
index e3671047b4..d4af2c6b01 100644
--- a/indra/llcommon/lluuid.cpp
+++ b/indra/llcommon/lluuid.cpp
@@ -83,7 +83,7 @@ unsigned int decode( char const * fiveChars ) throw( bad_input_data )
 unsigned int ret = 0;
 for( int ix = 0; ix < 5; ++ix ) {
 char * s = strchr( encodeTable, fiveChars[ ix ] );
-if( s == 0 ) throw bad_input_data();
+if( s == 0 ) LLTHROW(bad_input_data());
 ret = ret * 85 + (s-encodeTable);
 }
 return ret;
diff --git a/indra/llcommon/tests/llexception_test.cpp b/indra/llcommon/tests/llexception_test.cpp
new file mode 100644
index 0000000000..6bee1943c2
--- /dev/null
+++ b/indra/llcommon/tests/llexception_test.cpp
@@ -0,0 +1,308 @@
+/**
+ * @file   llexception_test.cpp
+ * @author Nat Goodspeed
+ * @date   2016-08-12
+ * @brief  Tests for throwing exceptions.
+ *
+ * This isn't a regression test: it doesn't need to be run every build, which
+ * is why the corresponding line in llcommon/CMakeLists.txt is commented out.
+ * Rather it's a head-to-head test of what kind of exception information we
+ * can collect from various combinations of exception base classes, type of
+ * throw verb and sequences of catch clauses.
+ *
+ * This "test" makes no ensure() calls: its output goes to stdout for human
+ * examination.
+ *
+ * As of 2016-08-12 with Boost 1.57, we come to the following conclusions.
+ * These should probably be re-examined from time to time as we update Boost.
+ *
+ * - It is indisputably beneficial to use BOOST_THROW_EXCEPTION() rather than
+ *   plain throw. The macro annotates the exception object with the filename,
+ *   line number and function name from which the exception was thrown.
+ *
+ * - That being the case, deriving only from boost::exception isn't an option.
+ *   Every exception object passed to BOOST_THROW_EXCEPTION() must be derived
+ *   directly or indirectly from std::exception. The only question is whether
+ *   to also derive from boost::exception. We decided to derive LLException
+ *   from both, as it makes message output slightly cleaner, but this is a
+ *   trivial reason: if a strong reason emerges to prefer single inheritance,
+ *   dropping the boost::exception base class shouldn't be a problem.
+ *
+ * - (As you will have guessed, ridiculous things like a char* or int or a
+ *   class derived from neither boost::exception nor std::exception can only
+ *   be caught by that specific type or (...), and
+ *   boost::current_exception_diagnostic_information() simply throws up its
+ *   hands and confesses utter ignorance. Stay away from such nonsense.)
+ *
+ * - But if you derive from std::exception, to nat's surprise,
+ *   boost::current_exception_diagnostic_information() gives as much
+ *   information about exceptions in a catch (...) clause as you can get from
+ *   a specific catch (const std::exception&) clause, notably the concrete
+ *   exception class and the what() string. So instead of a sequence like
+ *
+ *   try { ... }
+ *   catch (const boost::exception& e) { ... boost-flavored logging ... }
+ *   catch (const std::exception& e)   { ... std::exception logging ... }
+ *   catch (...)                       { ... generic logging ... }
+ *
+ *   we should be able to get away with only a catch (...) clause that logs
+ *   boost::current_exception_diagnostic_information().
+ *
+ * - Going further: boost::current_exception_diagnostic_information() provides
+ *   just as much information even within a std::set_terminate() handler. So
+ *   it might not even be strictly necessary to include a catch (...) clause
+ *   since the viewer does use std::set_terminate().
+ *
+ * - (We might consider adding a catch (int) clause because Kakadu internally
+ *   throws ints, and who knows if one of those might leak out. If it does,
+ *   boost::current_exception_diagnostic_information() can do nothing with it.
+ *   A catch (int) clause could at least log the value and rethrow.)
+ *
+ * $LicenseInfo:firstyear=2016&license=viewerlgpl$
+ * Copyright (c) 2016, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "linden_common.h"
+// associated header
+#include "llexception.h"
+// STL headers
+// std headers
+#include <typeinfo>
+// external library headers
+#include <boost/throw_exception.hpp>
+// other Linden headers
+#include "../test/lltut.h"
+
+// helper for display output
+// usage: std::cout << center(some string value, fill char, width) << std::endl;
+// (assumes it's the only thing on that particular line)
+struct center
+{
+    center(const std::string& label, char fill, std::size_t width):
+        mLabel(label),
+        mFill(fill),
+        mWidth(width)
+    {}
+
+    // Use friend declaration not because we need to grant access, but because
+    // it lets us declare a free operator like a member function.
+    friend std::ostream& operator<<(std::ostream& out, const center& ctr)
+    {
+        std::size_t padded = ctr.mLabel.length() + 2;
+        std::size_t left  = (ctr.mWidth - padded) / 2;
+        std::size_t right = ctr.mWidth - left - padded;
+        return out << std::string(left, ctr.mFill) << ' ' << ctr.mLabel << ' '
+                   << std::string(right, ctr.mFill);
+    }
+
+    std::string mLabel;
+    char mFill;
+    std::size_t mWidth;
+};
+
+/*****************************************************************************
+*   Four kinds of exceptions: derived from boost::exception, from
+*   std::exception, from both, from neither
+*****************************************************************************/
+// Interestingly, we can't use this variant with BOOST_THROW_EXCEPTION()
+// (which we want) -- we reach a failure topped by this comment:
+//  //All boost exceptions are required to derive from std::exception,
+//  //to ensure compatibility with BOOST_NO_EXCEPTIONS.
+struct FromBoost: public boost::exception
+{
+    FromBoost(const std::string& what): mWhat(what) {}
+    ~FromBoost() throw() {}
+    std::string what() const { return mWhat; }
+    std::string mWhat;
+};
+
+struct FromStd: public std::runtime_error
+{
+    FromStd(const std::string& what): std::runtime_error(what) {}
+};
+
+struct FromBoth: public boost::exception, public std::runtime_error
+{
+    FromBoth(const std::string& what): std::runtime_error(what) {}
+};
+
+// Same deal with FromNeither: can't use with BOOST_THROW_EXCEPTION().
+struct FromNeither
+{
+    FromNeither(const std::string& what): mWhat(what) {}
+    std::string what() const { return mWhat; }
+    std::string mWhat;
+};
+
+/*****************************************************************************
+*   Two kinds of throws: plain throw and BOOST_THROW_EXCEPTION()
+*****************************************************************************/
+template <typename EXC>
+void plain_throw(const std::string& what)
+{
+    throw EXC(what);
+}
+
+template <typename EXC>
+void boost_throw(const std::string& what)
+{
+    BOOST_THROW_EXCEPTION(EXC(what));
+}
+
+// Okay, for completeness, functions that throw non-class values. We wouldn't
+// even deign to consider these if we hadn't found examples in our own source
+// code! (Note that Kakadu's internal exception support is still based on
+// throwing ints.)
+void throw_char_ptr(const std::string& what)
+{
+    throw what.c_str(); // umm...
+}
+
+void throw_int(const std::string& what)
+{
+    throw int(what.length());
+}
+
+/*****************************************************************************
+*   Three sequences of catch clauses:
+*   boost::exception then ...,
+*   std::exception then ...,
+*   or just ...
+*****************************************************************************/
+void catch_boost_dotdotdot(void (*thrower)(const std::string&), const std::string& what)
+{
+    try
+    {
+        thrower(what);
+    }
+    catch (const boost::exception& e)
+    {
+        std::cout << "catch (const boost::exception& e)" << std::endl;
+        std::cout << "e is " << typeid(e).name() << std::endl;
+        std::cout << "boost::diagnostic_information(e):\n'"
+                  << boost::diagnostic_information(e) << "'" << std::endl;
+        // no way to report e.what()
+    }
+    catch (...)
+    {
+        std::cout << "catch (...)" << std::endl;
+        std::cout << "boost::current_exception_diagnostic_information():\n'"
+                  << boost::current_exception_diagnostic_information() << "'"
+                  << std::endl;
+    }
+}
+
+void catch_std_dotdotdot(void (*thrower)(const std::string&), const std::string& what)
+{
+    try
+    {
+        thrower(what);
+    }
+    catch (const std::exception& e)
+    {
+        std::cout << "catch (const std::exception& e)" << std::endl;
+        std::cout << "e is " << typeid(e).name() << std::endl;
+        std::cout << "boost::diagnostic_information(e):\n'"
+                  << boost::diagnostic_information(e) << "'" << std::endl;
+        std::cout << "e.what: '"
+                  << e.what() << "'" << std::endl;
+    }
+    catch (...)
+    {
+        std::cout << "catch (...)" << std::endl;
+        std::cout << "boost::current_exception_diagnostic_information():\n'"
+                  << boost::current_exception_diagnostic_information() << "'"
+                  << std::endl;
+    }
+}
+
+void catch_dotdotdot(void (*thrower)(const std::string&), const std::string& what)
+{
+    try
+    {
+        thrower(what);
+    }
+    catch (...)
+    {
+        std::cout << "catch (...)" << std::endl;
+        std::cout << "boost::current_exception_diagnostic_information():\n'"
+                  << boost::current_exception_diagnostic_information() << "'"
+                  << std::endl;
+    }
+}
+
+/*****************************************************************************
+*   Try a particular kind of throw against each of three catch sequences
+*****************************************************************************/
+void catch_several(void (*thrower)(const std::string&), const std::string& what)
+{
+    std::cout << std::string(20, '-') << "catch_boost_dotdotdot(" << what << ")" << std::endl;
+    catch_boost_dotdotdot(thrower, "catch_boost_dotdotdot(" + what + ")");
+
+    std::cout << std::string(20, '-') << "catch_std_dotdotdot(" << what << ")" << std::endl;
+    catch_std_dotdotdot(thrower, "catch_std_dotdotdot(" + what + ")");
+
+    std::cout << std::string(20, '-') << "catch_dotdotdot(" << what << ")" << std::endl;
+    catch_dotdotdot(thrower, "catch_dotdotdot(" + what + ")");
+}
+
+/*****************************************************************************
+*   For a particular kind of exception, try both kinds of throw against all
+*   three catch sequences
+*****************************************************************************/
+template <typename EXC>
+void catch_both_several(const std::string& what)
+{
+    std::cout << std::string(20, '*') << "plain_throw<" << what << ">" << std::endl;
+    catch_several(plain_throw<EXC>, "plain_throw<" + what + ">");
+
+    std::cout << std::string(20, '*') << "boost_throw<" << what << ">" << std::endl;
+    catch_several(boost_throw<EXC>, "boost_throw<" + what + ">");
+}
+
+/*****************************************************************************
+*   TUT
+*****************************************************************************/
+namespace tut
+{
+    struct llexception_data
+    {
+    };
+    typedef test_group<llexception_data> llexception_group;
+    typedef llexception_group::object object;
+    llexception_group llexceptiongrp("llexception");
+
+    template<> template<>
+    void object::test<1>()
+    {
+        set_test_name("throwing exceptions");
+
+        // For each kind of exception, try both kinds of throw against all
+        // three catch sequences
+        std::size_t margin = 72;
+        std::cout << center("FromStd", '=', margin) << std::endl;
+        catch_both_several<FromStd>("FromStd");
+
+        std::cout << center("FromBoth", '=', margin) << std::endl;
+        catch_both_several<FromBoth>("FromBoth");
+
+        std::cout << center("FromBoost", '=', margin) << std::endl;
+        // can't throw with BOOST_THROW_EXCEPTION(), just use catch_several()
+        catch_several(plain_throw<FromBoost>, "plain_throw<FromBoost>");
+
+        std::cout << center("FromNeither", '=', margin) << std::endl;
+        // can't throw this with BOOST_THROW_EXCEPTION() either
+        catch_several(plain_throw<FromNeither>, "plain_throw<FromNeither>");
+
+        std::cout << center("const char*", '=', margin) << std::endl;
+        // We don't expect BOOST_THROW_EXCEPTION() to throw anything so daft
+        // as a const char* or an int, so don't bother with
+        // catch_both_several() -- just catch_several().
+        catch_several(throw_char_ptr, "throw_char_ptr");
+
+        std::cout << center("int", '=', margin) << std::endl;
+        catch_several(throw_int, "throw_int");
+    }
+} // namespace tut
diff --git a/indra/llcommon/tests/wrapllerrs.h b/indra/llcommon/tests/wrapllerrs.h
index 785197ba11..9a4bbbd630 100644
--- a/indra/llcommon/tests/wrapllerrs.h
+++ b/indra/llcommon/tests/wrapllerrs.h
@@ -35,13 +35,13 @@
 
 #include <tut/tut.hpp>
 #include "llerrorcontrol.h"
+#include "llexception.h"
 #include "stringize.h"
 #include <boost/bind.hpp>
 #include <boost/noncopyable.hpp>
 #include <boost/shared_ptr.hpp>
 #include <list>
 #include <string>
-#include <stdexcept>
 
 // statically reference the function in test.cpp... it's short, we could
 // replicate, but better to reuse
@@ -67,9 +67,9 @@ struct WrapLLErrs
         LLError::restoreSettings(mPriorErrorSettings);
     }
 
-    struct FatalException: public std::runtime_error
+    struct FatalException: public LLException
     {
-        FatalException(const std::string& what): std::runtime_error(what) {}
+        FatalException(const std::string& what): LLException(what) {}
     };
 
     void operator()(const std::string& message)
@@ -78,7 +78,7 @@ struct WrapLLErrs
         error = message;
         // Also throw an appropriate exception since calling code is likely to
         // assume that control won't continue beyond LL_ERRS.
-        throw FatalException(message);
+        LLTHROW(FatalException(message));
     }
 
     std::string error;
diff --git a/indra/llcrashlogger/llcrashlogger.h b/indra/llcrashlogger/llcrashlogger.h
index 8b4afae24a..56e26c23ba 100644
--- a/indra/llcrashlogger/llcrashlogger.h
+++ b/indra/llcrashlogger/llcrashlogger.h
@@ -57,7 +57,7 @@ public:
 	LLSD constructPostData();
 	virtual void updateApplication(const std::string& message = LLStringUtil::null);
 	virtual bool init();
-	virtual bool mainLoop() = 0;
+	virtual bool frame() = 0;
 	virtual bool cleanup() = 0;
 	void commonCleanup();
 	void setUserText(const std::string& text) { mCrashInfo["UserNotes"] = text; }
diff --git a/indra/llimage/llpngwrapper.cpp b/indra/llimage/llpngwrapper.cpp
index aad139f570..640eda7b01 100644
--- a/indra/llimage/llpngwrapper.cpp
+++ b/indra/llimage/llpngwrapper.cpp
@@ -31,6 +31,15 @@
 #include "llimage.h"
 #include "llpngwrapper.h"
 
+#include "llexception.h"
+
+namespace {
+struct PngError: public LLException
+{
+    PngError(png_const_charp msg): LLException(msg) {}
+};
+} // anonymous namespace
+
 // ---------------------------------------------------------------------------
 // LLPngWrapper
 // ---------------------------------------------------------------------------
@@ -75,11 +84,10 @@ BOOL LLPngWrapper::isValidPng(U8* src)
 }
 
 // Called by the libpng library when a fatal encoding or decoding error
-// occurs.  We simply throw the error message and let our try/catch
-// block clean up.
+// occurs. We throw PngError and let our try/catch block clean up.
 void LLPngWrapper::errorHandler(png_structp png_ptr, png_const_charp msg)
 {
-	throw msg;
+	LLTHROW(PngError(msg));
 }
 
 // Called by the libpng library when reading (decoding) the PNG file. We
@@ -129,7 +137,7 @@ BOOL LLPngWrapper::readPng(U8* src, S32 dataSize, LLImageRaw* rawImage, ImageInf
 			this, &errorHandler, NULL);
 		if (mReadPngPtr == NULL)
 		{
-			throw "Problem creating png read structure";
+			LLTHROW(PngError("Problem creating png read structure"));
 		}
 
 		// Allocate/initialize the memory for image information.
@@ -187,9 +195,9 @@ BOOL LLPngWrapper::readPng(U8* src, S32 dataSize, LLImageRaw* rawImage, ImageInf
 
 		mFinalSize = dataPtr.mOffset;
 	}
-	catch (png_const_charp msg)
+	catch (const PngError& msg)
 	{
-		mErrorMessage = msg;
+		mErrorMessage = msg.what();
 		releaseResources();
 		return (FALSE);
 	}
@@ -288,14 +296,14 @@ BOOL LLPngWrapper::writePng(const LLImageRaw* rawImage, U8* dest)
 
 		if (mColorType == -1)
 		{
-			throw "Unsupported image: unexpected number of channels";
+			LLTHROW(PngError("Unsupported image: unexpected number of channels"));
 		}
 
 		mWritePngPtr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
 			NULL, &errorHandler, NULL);
 		if (!mWritePngPtr)
 		{
-			throw "Problem creating png write structure";
+			LLTHROW(PngError("Problem creating png write structure"));
 		}
 
 		mWriteInfoPtr = png_create_info_struct(mWritePngPtr);
@@ -339,9 +347,9 @@ BOOL LLPngWrapper::writePng(const LLImageRaw* rawImage, U8* dest)
 		png_write_end(mWritePngPtr, mWriteInfoPtr);
 		mFinalSize = dataPtr.mOffset;
 	}
-	catch (png_const_charp msg)
+	catch (const PngError& msg)
 	{
-		mErrorMessage = msg;
+		mErrorMessage = msg.what();
 		releaseResources();
 		return (FALSE);
 	}
diff --git a/indra/llkdu/llimagej2ckdu.cpp b/indra/llkdu/llimagej2ckdu.cpp
index 9347e51b85..fe79079db3 100644
--- a/indra/llkdu/llimagej2ckdu.cpp
+++ b/indra/llkdu/llimagej2ckdu.cpp
@@ -34,6 +34,15 @@
 
 #include "kdu_block_coding.h"
 
+#include "llexception.h"
+
+namespace {
+struct KDUError: public LLException
+{
+    KDUError(const std::string& msg): LLException(msg) {}
+};
+} // anonymous namespace
+
 class kdc_flow_control {
 	
 public:
@@ -167,7 +176,7 @@ struct LLKDUMessageError : public LLKDUMessage
 		// exception if we want to recover from a KDU error.
 		if (end_of_message) 
 		{
-			throw "KDU throwing an exception";
+		LLTHROW(KDUError("LLKDUMessageError::flush()"));
 		}
 	}
 };
@@ -384,9 +393,9 @@ bool LLImageJ2CKDU::initDecode(LLImageJ2C &base, LLImageRaw &raw_image, F32 deco
 			mTPosp->x = 0;
 		}
 	}
-	catch (const char* msg)
+	catch (const KDUError& msg)
 	{
-		base.setLastError(ll_safe_string(msg));
+		base.setLastError(msg.what());
 		return false;
 	}
 	catch (...)
@@ -480,9 +489,9 @@ bool LLImageJ2CKDU::decodeImpl(LLImageJ2C &base, LLImageRaw &raw_image, F32 deco
 					return false;
 				}
 			}
-			catch (const char* msg)
+			catch (const KDUError& msg)
 			{
-				base.setLastError(ll_safe_string(msg));
+				base.setLastError(msg.what());
 				base.decodeFailed();
 				cleanupCodeStream();
 				return true; // done
@@ -673,9 +682,9 @@ bool LLImageJ2CKDU::encodeImpl(LLImageJ2C &base, const LLImageRaw &raw_image, co
 		base.updateData(); // set width, height
 		delete[] output_buffer;
 	}
-	catch(const char* msg)
+	catch(const KDUError& msg)
 	{
-		base.setLastError(ll_safe_string(msg));
+		base.setLastError(msg.what());
 		return false;
 	}
 	catch( ... )
@@ -697,9 +706,9 @@ bool LLImageJ2CKDU::getMetadata(LLImageJ2C &base)
 		setupCodeStream(base, false, MODE_FAST);
 		return true;
 	}
-	catch (const char* msg)
+	catch (const KDUError& msg)
 	{
-		base.setLastError(ll_safe_string(msg));
+		base.setLastError(msg.what());
 		return false;
 	}
 	catch (...)
diff --git a/indra/llmessage/llhttpnode.cpp b/indra/llmessage/llhttpnode.cpp
index f235965879..04b34a296c 100644
--- a/indra/llmessage/llhttpnode.cpp
+++ b/indra/llmessage/llhttpnode.cpp
@@ -31,6 +31,7 @@
 
 #include "llstl.h"
 #include "llhttpconstants.h"
+#include "llexception.h"
 
 const std::string CONTEXT_HEADERS("headers");
 const std::string CONTEXT_PATH("path");
@@ -92,27 +93,28 @@ LLHTTPNode::~LLHTTPNode()
 
 
 namespace {
-	class NotImplemented
+	struct NotImplemented: public LLException
 	{
+		NotImplemented(): LLException("LLHTTPNode::NotImplemented") {}
 	};
 }
 
 // virtual
 LLSD LLHTTPNode::simpleGet() const
 {
-	throw NotImplemented();
+	LLTHROW(NotImplemented());
 }
 
 // virtual
 LLSD LLHTTPNode::simplePut(const LLSD& input) const
 {
-	throw NotImplemented();
+	LLTHROW(NotImplemented());
 }
 
 // virtual
 LLSD LLHTTPNode::simplePost(const LLSD& input) const
 {
-	throw NotImplemented();
+	LLTHROW(NotImplemented());
 }
 
 
@@ -172,7 +174,7 @@ void LLHTTPNode::del(LLHTTPNode::ResponsePtr response, const LLSD& context) cons
 // virtual
 LLSD LLHTTPNode::simpleDel(const LLSD&) const
 {
-	throw NotImplemented();
+	LLTHROW(NotImplemented());
 }
 
 // virtual
diff --git a/indra/llmessage/tests/commtest.h b/indra/llmessage/tests/commtest.h
index 0d149b5258..7c8f27bbd2 100644
--- a/indra/llmessage/tests/commtest.h
+++ b/indra/llmessage/tests/commtest.h
@@ -33,15 +33,15 @@
 #include "llevents.h"
 #include "llsd.h"
 #include "llhost.h"
+#include "llexception.h"
 #include "stringize.h"
 #include <map>
 #include <string>
-#include <stdexcept>
 #include <boost/lexical_cast.hpp>
 
-struct CommtestError: public std::runtime_error
+struct CommtestError: public LLException
 {
-    CommtestError(const std::string& what): std::runtime_error(what) {}
+    CommtestError(const std::string& what): LLException(what) {}
 };
 
 static bool query_verbose()
@@ -68,7 +68,7 @@ static int query_port(const std::string& var)
     const char* cport = getenv(var.c_str());
     if (! cport)
     {
-        throw CommtestError(STRINGIZE("missing environment variable" << var));
+        LLTHROW(CommtestError(STRINGIZE("missing environment variable" << var)));
     }
     // This will throw, too, if the value of PORT isn't numeric.
     int port(boost::lexical_cast<int>(cport));
diff --git a/indra/llmessage/tests/networkio.h b/indra/llmessage/tests/networkio.h
index 2aff90ca1e..5eb739393f 100644
--- a/indra/llmessage/tests/networkio.h
+++ b/indra/llmessage/tests/networkio.h
@@ -34,6 +34,7 @@
 #include "llares.h"
 #include "llpumpio.h"
 #include "llhttpclient.h"
+#include "llexception.h"
 
 /*****************************************************************************
 *   NetworkIO
@@ -51,7 +52,7 @@ public:
         ll_init_apr();
         if (! gAPRPoolp)
         {
-            throw std::runtime_error("Can't initialize APR");
+            LLTHROW(LLException("Can't initialize APR"));
         }
 
         // Create IO Pump to use for HTTP Requests.
@@ -59,7 +60,7 @@ public:
         LLHTTPClient::setPump(*mServicePump);
         if (ll_init_ares() == NULL || !gAres->isInitialized())
         {
-            throw std::runtime_error("Can't start DNS resolver");
+            LLTHROW(LLException("Can't start DNS resolver"));
         }
 
         // You can interrupt pump() without waiting the full timeout duration
diff --git a/indra/llwindow/llappdelegate-objc.h b/indra/llwindow/llappdelegate-objc.h
index faa5d3abb7..6daf1ac55b 100644
--- a/indra/llwindow/llappdelegate-objc.h
+++ b/indra/llwindow/llappdelegate-objc.h
@@ -41,7 +41,7 @@
 
 @property (retain) NSString *currentInputLanguage;
 
-- (void) mainLoop;
+- (void) oneFrame;
 - (void) showInputWindow:(bool)show withEvent:(NSEvent*)textEvent;
 - (void) languageUpdated;
 - (bool) romanScript;
diff --git a/indra/llwindow/llwindowmacosx-objc.h b/indra/llwindow/llwindowmacosx-objc.h
index c22f3382fb..b06cd2c184 100644
--- a/indra/llwindow/llwindowmacosx-objc.h
+++ b/indra/llwindow/llwindowmacosx-objc.h
@@ -69,7 +69,7 @@ typedef const NativeKeyEventData * NSKeyEventRef;
 // These are defined in llappviewermacosx.cpp.
 bool initViewer();
 void handleQuit();
-bool runMainLoop();
+bool pumpMainLoop();
 void initMainLoop();
 void cleanupViewer();
 void handleUrl(const char* url);
diff --git a/indra/mac_crash_logger/llcrashloggermac.cpp b/indra/mac_crash_logger/llcrashloggermac.cpp
index 3149fad6e8..ec3616e26a 100644
--- a/indra/mac_crash_logger/llcrashloggermac.cpp
+++ b/indra/mac_crash_logger/llcrashloggermac.cpp
@@ -64,7 +64,7 @@ void LLCrashLoggerMac::gatherPlatformSpecificFiles()
 {
 }
 
-bool LLCrashLoggerMac::mainLoop()
+bool LLCrashLoggerMac::frame()
 {
 
     if (mCrashBehavior == CRASH_BEHAVIOR_ALWAYS_SEND)
diff --git a/indra/mac_crash_logger/llcrashloggermac.h b/indra/mac_crash_logger/llcrashloggermac.h
index 6d8f63ecac..05ef8c9f53 100644
--- a/indra/mac_crash_logger/llcrashloggermac.h
+++ b/indra/mac_crash_logger/llcrashloggermac.h
@@ -37,7 +37,7 @@ public:
 	LLCrashLoggerMac(void);
 	~LLCrashLoggerMac(void);
 	virtual bool init();
-	virtual bool mainLoop();
+	virtual bool frame();
 	virtual bool cleanup();
 	virtual void gatherPlatformSpecificFiles();
 };
diff --git a/indra/mac_crash_logger/mac_crash_logger.cpp b/indra/mac_crash_logger/mac_crash_logger.cpp
index 95d4e65207..54e41a1954 100644
--- a/indra/mac_crash_logger/mac_crash_logger.cpp
+++ b/indra/mac_crash_logger/mac_crash_logger.cpp
@@ -49,7 +49,7 @@ int main(int argc, char **argv)
     {
 //        return NSApplicationMain(argc, (const char **)argv);
     }
-	app.mainLoop();
+	app.frame();
 	app.cleanup();
 
 	LL_INFOS() << "Crash reporter finished normally." << LL_ENDL;
diff --git a/indra/newview/llappcorehttp.cpp b/indra/newview/llappcorehttp.cpp
index 49291ea564..dbcae57de7 100644
--- a/indra/newview/llappcorehttp.cpp
+++ b/indra/newview/llappcorehttp.cpp
@@ -534,7 +534,7 @@ LLCore::HttpStatus LLAppCoreHttp::sslVerify(const std::string &url,
 		// somewhat clumsy, as we may run into errors that do not map directly to curl
 		// error codes.  Should be refactored with login refactoring, perhaps.
 		result = LLCore::HttpStatus(LLCore::HttpStatus::EXT_CURL_EASY, CURLE_SSL_CACERT);
-		result.setMessage(cert_exception.getMessage());
+		result.setMessage(cert_exception.what());
 		LLPointer<LLCertificate> cert = cert_exception.getCert();
 		cert->ref(); // adding an extra ref here
 		result.setErrorData(cert.get());
@@ -544,7 +544,7 @@ LLCore::HttpStatus LLAppCoreHttp::sslVerify(const std::string &url,
 	catch (LLCertException &cert_exception)
 	{
 		result = LLCore::HttpStatus(LLCore::HttpStatus::EXT_CURL_EASY, CURLE_SSL_PEER_CERTIFICATE);
-		result.setMessage(cert_exception.getMessage());
+		result.setMessage(cert_exception.what());
 		LLPointer<LLCertificate> cert = cert_exception.getCert();
 		cert->ref(); // adding an extra ref here
 		result.setErrorData(cert.get());
diff --git a/indra/newview/llappdelegate-objc.mm b/indra/newview/llappdelegate-objc.mm
index 549df80fa1..be8877328d 100644
--- a/indra/newview/llappdelegate-objc.mm
+++ b/indra/newview/llappdelegate-objc.mm
@@ -48,16 +48,19 @@
 - (void) applicationDidFinishLaunching:(NSNotification *)notification
 {
 	frameTimer = nil;
-	
+
 	[self languageUpdated];
-	
+
 	if (initViewer())
 	{
-		frameTimer = [NSTimer scheduledTimerWithTimeInterval:0.0 target:self selector:@selector(mainLoop) userInfo:nil repeats:YES];
+		// Set up recurring calls to oneFrame (repeating timer with timeout 0)
+		// until applicationShouldTerminate.
+		frameTimer = [NSTimer scheduledTimerWithTimeInterval:0.0 target:self
+							  selector:@selector(oneFrame) userInfo:nil repeats:YES];
 	} else {
 		handleQuit();
 	}
-	
+
 	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(languageUpdated) name:@"NSTextInputContextKeyboardSelectionDidChangeNotification" object:nil];
 
  //   [[NSAppleEventManager sharedAppleEventManager] setEventHandler:self andSelector:@selector(handleGetURLEvent:withReplyEvent:) forEventClass:kInternetEventClass andEventID:kAEGetURL];
@@ -96,22 +99,29 @@
 
 - (NSApplicationDelegateReply) applicationShouldTerminate:(NSApplication *)sender
 {
-	if (!runMainLoop())
+	// run one frame to assess state
+	if (!pumpMainLoop())
 	{
+		// pumpMainLoop() returns true when done, false if it wants to be
+		// called again. Since it returned false, do not yet cancel
+		// frameTimer.
 		handleQuit();
 		return NSTerminateCancel;
 	} else {
+		// pumpMainLoop() returned true: it's done. Okay, done with frameTimer.
 		[frameTimer release];
 		cleanupViewer();
 		return NSTerminateNow;
 	}
 }
 
-- (void) mainLoop
+- (void) oneFrame
 {
-	bool appExiting = runMainLoop();
+	bool appExiting = pumpMainLoop();
 	if (appExiting)
 	{
+		// Once pumpMainLoop() reports that we're done, cancel frameTimer:
+		// stop the repetitive calls.
 		[frameTimer release];
 		[[NSApplication sharedApplication] terminate:self];
 	}
diff --git a/indra/newview/llappviewer.cpp b/indra/newview/llappviewer.cpp
index 6bc1f67e32..766c807169 100644
--- a/indra/newview/llappviewer.cpp
+++ b/indra/newview/llappviewer.cpp
@@ -122,6 +122,7 @@
 #include "llleap.h"
 #include "stringize.h"
 #include "llcoros.h"
+#include "llexception.h"
 #if !LL_LINUX
 #include "cef/llceflib.h"
 #endif
@@ -231,7 +232,6 @@
 #include "llcoproceduremanager.h"
 #include "llviewereventrecorder.h"
 
-
 // *FIX: These extern globals should be cleaned up.
 // The globals either represent state/config/resource-storage of either 
 // this app, or another 'component' of the viewer. App globals should be 
@@ -769,9 +769,6 @@ bool LLAppViewer::init()
 	//
 	// Start of the application
 	//
-#ifdef LL_DARWIN
-	mMainLoopInitialized = false;
-#endif
 
 	// initialize LLWearableType translation bridge.
 	// Memory will be cleaned up in ::cleanupClass()
@@ -1220,6 +1217,23 @@ bool LLAppViewer::init()
         boost::bind(&LLControlGroup::getU32, boost::ref(gSavedSettings), _1),
         boost::bind(&LLControlGroup::declareU32, boost::ref(gSavedSettings), _1, _2, _3, LLControlVariable::PERSIST_ALWAYS));
 
+	/*----------------------------------------------------------------------*/
+	// nat 2016-06-29 moved the following here from the former mainLoop().
+	mMainloopTimeout = new LLWatchdogTimeout();
+
+	// Create IO Pump to use for HTTP Requests.
+	gServicePump = new LLPumpIO(gAPRPoolp);
+
+	// Note: this is where gLocalSpeakerMgr and gActiveSpeakerMgr used to be instantiated.
+
+	LLVoiceChannel::initClass();
+	LLVoiceClient::getInstance()->init(gServicePump);
+	LLVoiceChannel::setCurrentVoiceChannelChangedCallback(boost::bind(&LLFloaterIMContainer::onCurrentChannelChanged, _1), true);
+
+	joystick = LLViewerJoystick::getInstance();
+	joystick->setNeedsReset(true);
+	/*----------------------------------------------------------------------*/
+
 	return true;
 }
 
@@ -1294,297 +1308,255 @@ static LLTrace::BlockTimerStatHandle FTM_AGENT_UPDATE("Update");
 // externally visible timers
 LLTrace::BlockTimerStatHandle FTM_FRAME("Frame");
 
-bool LLAppViewer::mainLoop()
+bool LLAppViewer::frame()
 {
-#ifdef LL_DARWIN
-	if (!mMainLoopInitialized)
-#endif
-	{
-        LL_INFOS() << "Entering main_loop" << LL_ENDL;
-		mMainloopTimeout = new LLWatchdogTimeout();
-		
-		//-------------------------------------------
-		// Run main loop until time to quit
-		//-------------------------------------------
-		
-		// Create IO Pump to use for HTTP Requests.
-		gServicePump = new LLPumpIO(gAPRPoolp);
-		
-		// Note: this is where gLocalSpeakerMgr and gActiveSpeakerMgr used to be instantiated.
-		
-		LLVoiceChannel::initClass();
-		LLVoiceClient::getInstance()->init(gServicePump);
-		LLVoiceChannel::setCurrentVoiceChannelChangedCallback(boost::bind(&LLFloaterIMContainer::onCurrentChannelChanged, _1), true);
-		
-		joystick = LLViewerJoystick::getInstance();
-		joystick->setNeedsReset(true);
-		
-#ifdef LL_DARWIN
-		// Ensure that this section of code never gets called again on OS X.
-		mMainLoopInitialized = true;
-#endif
-	}
-	// As we do not (yet) send data on the mainloop LLEventPump that varies
-	// with each frame, no need to instantiate a new LLSD event object each
-	// time. Obviously, if that changes, just instantiate the LLSD at the
-	// point of posting.
-	
 	LLEventPump& mainloop(LLEventPumps::instance().obtain("mainloop"));
-	
-    LLSD newFrame;
-	
+	LLSD newFrame;
+
 	LLTimer frameTimer,idleTimer;
 	LLTimer debugTime;
-	
+
 	//LLPrivateMemoryPoolTester::getInstance()->run(false) ;
 	//LLPrivateMemoryPoolTester::getInstance()->run(true) ;
 	//LLPrivateMemoryPoolTester::destroy() ;
 
-	// Handle messages
-#ifdef LL_DARWIN
-	if (!LLApp::isExiting())
-#else
-	while (!LLApp::isExiting())
-#endif
+	LL_RECORD_BLOCK_TIME(FTM_FRAME);
+	LLTrace::BlockTimer::processTimes();
+	LLTrace::get_frame_recording().nextPeriod();
+	LLTrace::BlockTimer::logStats();
+
+	LLTrace::get_thread_recorder()->pullFromChildren();
+
+	//clear call stack records
+	LL_CLEAR_CALLSTACKS();
+
+	//check memory availability information
+	checkMemory() ;
+
+	try
 	{
-		LL_RECORD_BLOCK_TIME(FTM_FRAME);
-		LLTrace::BlockTimer::processTimes();
-		LLTrace::get_frame_recording().nextPeriod();
-		LLTrace::BlockTimer::logStats();
+		pingMainloopTimeout("Main:MiscNativeWindowEvents");
+
+		if (gViewerWindow)
+		{
+			LL_RECORD_BLOCK_TIME(FTM_MESSAGES);
+			gViewerWindow->getWindow()->processMiscNativeEvents();
+		}
 
-		LLTrace::get_thread_recorder()->pullFromChildren();
+		pingMainloopTimeout("Main:GatherInput");
 
-		//clear call stack records
-		LL_CLEAR_CALLSTACKS();
+		if (gViewerWindow)
+		{
+			LL_RECORD_BLOCK_TIME(FTM_MESSAGES);
+			if (!restoreErrorTrap())
+			{
+				LL_WARNS() << " Someone took over my signal/exception handler (post messagehandling)!" << LL_ENDL;
+			}
 
-		//check memory availability information
-		checkMemory() ;
+			gViewerWindow->getWindow()->gatherInput();
+		}
+
+#if 1 && !LL_RELEASE_FOR_DOWNLOAD
+		// once per second debug info
+		if (debugTime.getElapsedTimeF32() > 1.f)
+		{
+			debugTime.reset();
+		}
 		
-		try
+#endif
+		//memory leaking simulation
+		LLFloaterMemLeak* mem_leak_instance =
+			LLFloaterReg::findTypedInstance<LLFloaterMemLeak>("mem_leaking");
+		if(mem_leak_instance)
 		{
-			pingMainloopTimeout("Main:MiscNativeWindowEvents");
+			mem_leak_instance->idle() ;				
+		}							
+
+		// canonical per-frame event
+		mainloop.post(newFrame);
 
-			if (gViewerWindow)
+		if (!LLApp::isExiting())
+		{
+			pingMainloopTimeout("Main:JoystickKeyboard");
+
+			// Scan keyboard for movement keys.  Command keys and typing
+			// are handled by windows callbacks.  Don't do this until we're
+			// done initializing.  JC
+			if ((gHeadlessClient || gViewerWindow->getWindow()->getVisible())
+				&& gViewerWindow->getActive()
+				&& !gViewerWindow->getWindow()->getMinimized()
+				&& LLStartUp::getStartupState() == STATE_STARTED
+				&& (gHeadlessClient || !gViewerWindow->getShowProgress())
+				&& !gFocusMgr.focusLocked())
 			{
-				LL_RECORD_BLOCK_TIME(FTM_MESSAGES);
-				gViewerWindow->getWindow()->processMiscNativeEvents();
+				joystick->scanJoystick();
+				gKeyboard->scanKeyboard();
 			}
-		
-			pingMainloopTimeout("Main:GatherInput");
-			
-			if (gViewerWindow)
+
+			// Update state based on messages, user input, object idle.
 			{
-				LL_RECORD_BLOCK_TIME(FTM_MESSAGES);
-				if (!restoreErrorTrap())
-				{
-					LL_WARNS() << " Someone took over my signal/exception handler (post messagehandling)!" << LL_ENDL;
-				}
+				pauseMainloopTimeout(); // *TODO: Remove. Messages shouldn't be stalling for 20+ seconds!
+				
+				LL_RECORD_BLOCK_TIME(FTM_IDLE);
+				idle();
 
-				gViewerWindow->getWindow()->gatherInput();
+				resumeMainloopTimeout();
 			}
 
-#if 1 && !LL_RELEASE_FOR_DOWNLOAD
-			// once per second debug info
-			if (debugTime.getElapsedTimeF32() > 1.f)
+			if (gDoDisconnect && (LLStartUp::getStartupState() == STATE_STARTED))
 			{
-				debugTime.reset();
+				pauseMainloopTimeout();
+				saveFinalSnapshot();
+				disconnectViewer();
+				resumeMainloopTimeout();
 			}
-			
-#endif
-			//memory leaking simulation
-			LLFloaterMemLeak* mem_leak_instance =
-				LLFloaterReg::findTypedInstance<LLFloaterMemLeak>("mem_leaking");
-			if(mem_leak_instance)
-			{
-				mem_leak_instance->idle() ;				
-			}							
 
-            // canonical per-frame event
-            mainloop.post(newFrame);
-
-			if (!LLApp::isExiting())
+			// Render scene.
+			// *TODO: Should we run display() even during gHeadlessClient?  DK 2011-02-18
+			if (!LLApp::isExiting() && !gHeadlessClient)
 			{
-				pingMainloopTimeout("Main:JoystickKeyboard");
-				
-				// Scan keyboard for movement keys.  Command keys and typing
-				// are handled by windows callbacks.  Don't do this until we're
-				// done initializing.  JC
-				if ((gHeadlessClient || gViewerWindow->getWindow()->getVisible())
-					&& gViewerWindow->getActive()
-					&& !gViewerWindow->getWindow()->getMinimized()
-					&& LLStartUp::getStartupState() == STATE_STARTED
-					&& (gHeadlessClient || !gViewerWindow->getShowProgress())
-					&& !gFocusMgr.focusLocked())
-				{
-					joystick->scanJoystick();
-					gKeyboard->scanKeyboard();
-				}
+				pingMainloopTimeout("Main:Display");
+				gGLActive = TRUE;
+				display();
+				pingMainloopTimeout("Main:Snapshot");
+				LLFloaterSnapshot::update(); // take snapshots
+				gGLActive = FALSE;
+			}
+		}
 
-				// Update state based on messages, user input, object idle.
-				{
-					pauseMainloopTimeout(); // *TODO: Remove. Messages shouldn't be stalling for 20+ seconds!
-					
-					LL_RECORD_BLOCK_TIME(FTM_IDLE);
-					idle();
+		pingMainloopTimeout("Main:Sleep");
 
-					resumeMainloopTimeout();
-				}
- 
-				if (gDoDisconnect && (LLStartUp::getStartupState() == STATE_STARTED))
-				{
-					pauseMainloopTimeout();
-					saveFinalSnapshot();
-					disconnectViewer();
-					resumeMainloopTimeout();
-				}
+		pauseMainloopTimeout();
 
-				// Render scene.
-				// *TODO: Should we run display() even during gHeadlessClient?  DK 2011-02-18
-				if (!LLApp::isExiting() && !gHeadlessClient)
+		// Sleep and run background threads
+		{
+			LL_RECORD_BLOCK_TIME(FTM_SLEEP);
+			
+			// yield some time to the os based on command line option
+			if(mYieldTime >= 0)
+			{
+				LL_RECORD_BLOCK_TIME(FTM_YIELD);
+				ms_sleep(mYieldTime);
+			}
+
+			// yield cooperatively when not running as foreground window
+			if (   (gViewerWindow && !gViewerWindow->getWindow()->getVisible())
+					|| !gFocusMgr.getAppHasFocus())
+			{
+				// Sleep if we're not rendering, or the window is minimized.
+				S32 milliseconds_to_sleep = llclamp(gSavedSettings.getS32("BackgroundYieldTime"), 0, 1000);
+				// don't sleep when BackgroundYieldTime set to 0, since this will still yield to other threads
+				// of equal priority on Windows
+				if (milliseconds_to_sleep > 0)
 				{
-					pingMainloopTimeout("Main:Display");
-					gGLActive = TRUE;
-					display();
-					pingMainloopTimeout("Main:Snapshot");
-					LLFloaterSnapshot::update(); // take snapshots
-					gGLActive = FALSE;
+					ms_sleep(milliseconds_to_sleep);
+					// also pause worker threads during this wait period
+					LLAppViewer::getTextureCache()->pause();
+					LLAppViewer::getImageDecodeThread()->pause();
 				}
 			}
-
-			pingMainloopTimeout("Main:Sleep");
 			
-			pauseMainloopTimeout();
+			if (mRandomizeFramerate)
+			{
+				ms_sleep(rand() % 200);
+			}
 
-			// Sleep and run background threads
+			if (mPeriodicSlowFrame
+				&& (gFrameCount % 10 == 0))
 			{
-				LL_RECORD_BLOCK_TIME(FTM_SLEEP);
-				
-				// yield some time to the os based on command line option
-				if(mYieldTime >= 0)
-				{
-					LL_RECORD_BLOCK_TIME(FTM_YIELD);
-					ms_sleep(mYieldTime);
-				}
+				LL_INFOS() << "Periodic slow frame - sleeping 500 ms" << LL_ENDL;
+				ms_sleep(500);
+			}
+
+			const F64Milliseconds max_idle_time = llmin(.005f*10.f*(F32Milliseconds)gFrameTimeSeconds, F32Milliseconds(5)); // 5 ms a second
+			idleTimer.reset();
+			S32 total_work_pending = 0;
+			S32 total_io_pending = 0;	
+			while(1)
+			{
+				S32 work_pending = 0;
+				S32 io_pending = 0;
+				F32 max_time = llmin(gFrameIntervalSeconds.value() *10.f, 1.f);
+
+				work_pending += updateTextureThreads(max_time);
 
-				// yield cooperatively when not running as foreground window
-				if (   (gViewerWindow && !gViewerWindow->getWindow()->getVisible())
-						|| !gFocusMgr.getAppHasFocus())
 				{
-					// Sleep if we're not rendering, or the window is minimized.
-					S32 milliseconds_to_sleep = llclamp(gSavedSettings.getS32("BackgroundYieldTime"), 0, 1000);
-					// don't sleep when BackgroundYieldTime set to 0, since this will still yield to other threads
-					// of equal priority on Windows
-					if (milliseconds_to_sleep > 0)
-					{
-						ms_sleep(milliseconds_to_sleep);
-						// also pause worker threads during this wait period
-						LLAppViewer::getTextureCache()->pause();
-						LLAppViewer::getImageDecodeThread()->pause();
-					}
+					LL_RECORD_BLOCK_TIME(FTM_VFS);
+ 					io_pending += LLVFSThread::updateClass(1);
 				}
-				
-				if (mRandomizeFramerate)
 				{
-					ms_sleep(rand() % 200);
+					LL_RECORD_BLOCK_TIME(FTM_LFS);
+ 					io_pending += LLLFSThread::updateClass(1);
 				}
 
-				if (mPeriodicSlowFrame
-					&& (gFrameCount % 10 == 0))
+				if (io_pending > 1000)
 				{
-					LL_INFOS() << "Periodic slow frame - sleeping 500 ms" << LL_ENDL;
-					ms_sleep(500);
+					ms_sleep(llmin(io_pending/100,100)); // give the vfs some time to catch up
 				}
 
-				const F64Milliseconds max_idle_time = llmin(.005f*10.f*(F32Milliseconds)gFrameTimeSeconds, F32Milliseconds(5)); // 5 ms a second
-				idleTimer.reset();
-				S32 total_work_pending = 0;
-				S32 total_io_pending = 0;	
-				while(1)
-				{
-					S32 work_pending = 0;
-					S32 io_pending = 0;
-					F32 max_time = llmin(gFrameIntervalSeconds.value() *10.f, 1.f);
-
-					work_pending += updateTextureThreads(max_time);
-
-					{
-						LL_RECORD_BLOCK_TIME(FTM_VFS);
-	 					io_pending += LLVFSThread::updateClass(1);
-					}
-					{
-						LL_RECORD_BLOCK_TIME(FTM_LFS);
-	 					io_pending += LLLFSThread::updateClass(1);
-					}
-
-					if (io_pending > 1000)
-					{
-						ms_sleep(llmin(io_pending/100,100)); // give the vfs some time to catch up
-					}
-
-					total_work_pending += work_pending ;
-					total_io_pending += io_pending ;
-					
-					if (!work_pending || idleTimer.getElapsedTimeF64() >= max_idle_time)
-					{
-						break;
-					}
-				}
-				gMeshRepo.update() ;
+				total_work_pending += work_pending ;
+				total_io_pending += io_pending ;
 				
-				if(!total_work_pending) //pause texture fetching threads if nothing to process.
-				{
-					LLAppViewer::getTextureCache()->pause();
-					LLAppViewer::getImageDecodeThread()->pause();
-					LLAppViewer::getTextureFetch()->pause(); 
-				}
-				if(!total_io_pending) //pause file threads if nothing to process.
-				{
-					LLVFSThread::sLocal->pause(); 
-					LLLFSThread::sLocal->pause(); 
-				}									
-
-				//texture fetching debugger
-				if(LLTextureFetchDebugger::isEnabled())
+				if (!work_pending || idleTimer.getElapsedTimeF64() >= max_idle_time)
 				{
-					LLFloaterTextureFetchDebugger* tex_fetch_debugger_instance =
-						LLFloaterReg::findTypedInstance<LLFloaterTextureFetchDebugger>("tex_fetch_debugger");
-					if(tex_fetch_debugger_instance)
-					{
-						tex_fetch_debugger_instance->idle() ;				
-					}
+					break;
 				}
+			}
+			gMeshRepo.update() ;
+			
+			if(!total_work_pending) //pause texture fetching threads if nothing to process.
+			{
+				LLAppViewer::getTextureCache()->pause();
+				LLAppViewer::getImageDecodeThread()->pause();
+				LLAppViewer::getTextureFetch()->pause(); 
+			}
+			if(!total_io_pending) //pause file threads if nothing to process.
+			{
+				LLVFSThread::sLocal->pause(); 
+				LLLFSThread::sLocal->pause(); 
+			}									
 
-				if ((LLStartUp::getStartupState() >= STATE_CLEANUP) &&
-					(frameTimer.getElapsedTimeF64() > FRAME_STALL_THRESHOLD))
+			//texture fetching debugger
+			if(LLTextureFetchDebugger::isEnabled())
+			{
+				LLFloaterTextureFetchDebugger* tex_fetch_debugger_instance =
+					LLFloaterReg::findTypedInstance<LLFloaterTextureFetchDebugger>("tex_fetch_debugger");
+				if(tex_fetch_debugger_instance)
 				{
-					gFrameStalls++;
+					tex_fetch_debugger_instance->idle() ;				
 				}
-				frameTimer.reset();
-
-				resumeMainloopTimeout();
-	
-				pingMainloopTimeout("Main:End");
-			}	
-		}
-		catch(std::bad_alloc)
-		{			
-			LLMemory::logMemoryInfo(TRUE) ;
+			}
 
-			//stop memory leaking simulation
-			LLFloaterMemLeak* mem_leak_instance =
-				LLFloaterReg::findTypedInstance<LLFloaterMemLeak>("mem_leaking");
-			if(mem_leak_instance)
+			if ((LLStartUp::getStartupState() >= STATE_CLEANUP) &&
+				(frameTimer.getElapsedTimeF64() > FRAME_STALL_THRESHOLD))
 			{
-				mem_leak_instance->stop() ;				
-				LL_WARNS() << "Bad memory allocation in LLAppViewer::mainLoop()!" << LL_ENDL ;
+				gFrameStalls++;
 			}
-			else
-			{
-				//output possible call stacks to log file.
-				LLError::LLCallStacks::print() ;
+			frameTimer.reset();
 
-				LL_ERRS() << "Bad memory allocation in LLAppViewer::mainLoop()!" << LL_ENDL ;
-			}
+			resumeMainloopTimeout();
+
+			pingMainloopTimeout("Main:End");
+		}	
+	}
+	catch(std::bad_alloc)
+	{			
+		LLMemory::logMemoryInfo(TRUE) ;
+
+		//stop memory leaking simulation
+		LLFloaterMemLeak* mem_leak_instance =
+			LLFloaterReg::findTypedInstance<LLFloaterMemLeak>("mem_leaking");
+		if(mem_leak_instance)
+		{
+			mem_leak_instance->stop() ;				
+			LL_WARNS() << "Bad memory allocation in LLAppViewer::frame()!" << LL_ENDL ;
+		}
+		else
+		{
+			//output possible call stacks to log file.
+			LLError::LLCallStacks::print() ;
+
+			LL_ERRS() << "Bad memory allocation in LLAppViewer::frame()!" << LL_ENDL ;
 		}
 	}
 
@@ -1618,7 +1590,7 @@ bool LLAppViewer::mainLoop()
 		LL_INFOS() << "Exiting main_loop" << LL_ENDL;
 	}
 
-	return LLApp::isExiting();
+	return ! LLApp::isRunning();
 }
 
 S32 LLAppViewer::updateTextureThreads(F32 max_time)
@@ -5546,8 +5518,7 @@ void LLAppViewer::forceErrorInfiniteLoop()
 void LLAppViewer::forceErrorSoftwareException()
 {
    	LL_WARNS() << "Forcing a deliberate exception" << LL_ENDL;
-    // *FIX: Any way to insure it won't be handled?
-    throw; 
+    LLTHROW(LLException("User selected Force Software Exception"));
 }
 
 void LLAppViewer::forceErrorDriverCrash()
diff --git a/indra/newview/llappviewer.h b/indra/newview/llappviewer.h
index b5e674bd7b..f7c1bb58b4 100644
--- a/indra/newview/llappviewer.h
+++ b/indra/newview/llappviewer.h
@@ -79,7 +79,7 @@ public:
 	//
 	virtual bool init();			// Override to do application initialization
 	virtual bool cleanup();			// Override to do application cleanup
-	virtual bool mainLoop(); // Override for the application main loop.  Needs to at least gracefully notice the QUITTING state and exit.
+	virtual bool frame(); // Override for application body logic
 
 	// Application control
 	void flushVFSIO(); // waits for vfs transfers to complete
@@ -283,7 +283,6 @@ private:
 	std::string mSerialNumber;
 	bool mPurgeCache;
     bool mPurgeOnExit;
-	bool mMainLoopInitialized;
 	LLViewerJoystick* joystick;
 
 	bool mSavedFinalSnapshot;
diff --git a/indra/newview/llappviewerlinux.cpp b/indra/newview/llappviewerlinux.cpp
index f5742b29cf..6f32aab851 100644
--- a/indra/newview/llappviewerlinux.cpp
+++ b/indra/newview/llappviewerlinux.cpp
@@ -95,10 +95,8 @@ int main( int argc, char **argv )
 	}
 
 		// Run the application main loop
-	if(!LLApp::isQuitting()) 
-	{
-		viewer_app_ptr->mainLoop();
-	}
+	while (! viewer_app_ptr->frame()) 
+	{}
 
 	if (!LLApp::isError())
 	{
diff --git a/indra/newview/llappviewermacosx.cpp b/indra/newview/llappviewermacosx.cpp
index ca219fda59..4fe1e31668 100644
--- a/indra/newview/llappviewermacosx.cpp
+++ b/indra/newview/llappviewermacosx.cpp
@@ -117,12 +117,17 @@ void handleQuit()
 	LLAppViewer::instance()->userQuit();
 }
 
-bool runMainLoop()
+// This function is called pumpMainLoop() rather than runMainLoop() because
+// it passes control to the viewer's main-loop logic for a single frame. Like
+// LLAppViewer::frame(), it returns 'true' when it's done. Until then, it
+// expects to be called again by the timer in LLAppDelegate
+// (llappdelegate-objc.mm).
+bool pumpMainLoop()
 {
 	bool ret = LLApp::isQuitting();
 	if (!ret && gViewerAppPtr != NULL)
 	{
-		ret = gViewerAppPtr->mainLoop();
+		ret = gViewerAppPtr->frame();
 	} else {
 		ret = true;
 	}
diff --git a/indra/newview/llappviewerwin32.cpp b/indra/newview/llappviewerwin32.cpp
index 4786f83bfd..a7f248ab5a 100644
--- a/indra/newview/llappviewerwin32.cpp
+++ b/indra/newview/llappviewerwin32.cpp
@@ -317,10 +317,8 @@ int APIENTRY WINMAIN(HINSTANCE hInstance,
 	}
 	
 	// Run the application main loop
-	if(!LLApp::isQuitting()) 
-	{
-		viewer_app_ptr->mainLoop();
-	}
+	while (! viewer_app_ptr->frame()) 
+	{}
 
 	if (!LLApp::isError())
 	{
diff --git a/indra/newview/llcommandlineparser.cpp b/indra/newview/llcommandlineparser.cpp
index 1819fc74ee..90a5483dc9 100644
--- a/indra/newview/llcommandlineparser.cpp
+++ b/indra/newview/llcommandlineparser.cpp
@@ -26,6 +26,7 @@
 
 #include "llviewerprecompiledheaders.h"
 #include "llcommandlineparser.h"
+#include "llexception.h"
 
 // *NOTE: The boost::lexical_cast generates 
 // the warning C4701(local used with out assignment) in VC7.1.
@@ -50,6 +51,7 @@
 #include "llsdserialize.h"
 #include "llerror.h"
 #include "stringize.h"
+#include "llexception.h"
 #include <string>
 #include <set>
 #include <iostream>
@@ -98,14 +100,14 @@ namespace
     bool gPastLastOption = false;
 }
 
-class LLCLPError : public std::logic_error {
+class LLCLPError : public LLException {
 public:
-    LLCLPError(const std::string& what) : std::logic_error(what) {}
+    LLCLPError(const std::string& what) : LLException(what) {}
 };
 
-class LLCLPLastOption : public std::logic_error {
+class LLCLPLastOption : public LLException {
 public:
-    LLCLPLastOption(const std::string& what) : std::logic_error(what) {}
+    LLCLPLastOption(const std::string& what) : LLException(what) {}
 };
 
 class LLCLPValue : public po::value_semantic_codecvt_helper<char> 
@@ -202,17 +204,17 @@ protected:
     {
         if(gPastLastOption)
         {
-            throw(LLCLPLastOption("Don't parse no more!"));
+            LLTHROW(LLCLPLastOption("Don't parse no more!"));
         }
 
         // Error checks. Needed?
         if (!value_store.empty() && !is_composing()) 
         {
-            throw(LLCLPError("Non composing value with multiple occurences."));
+            LLTHROW(LLCLPError("Non composing value with multiple occurences."));
         }
         if (new_tokens.size() < min_tokens() || new_tokens.size() > max_tokens())
         {
-            throw(LLCLPError("Illegal number of tokens specified."));
+            LLTHROW(LLCLPError("Illegal number of tokens specified."));
         }
         
         if(value_store.empty())
@@ -466,7 +468,7 @@ onevalue(const std::string& option,
     {
         // What does it mean when the user specifies a command-line switch
         // that requires a value, but omits the value? Complain.
-        throw LLCLPError(STRINGIZE("No value specified for --" << option << "!"));
+        LLTHROW(LLCLPError(STRINGIZE("No value specified for --" << option << "!")));
     }
     else if (value.size() > 1)
     {
@@ -484,9 +486,9 @@ void badvalue(const std::string& option,
     // If the user passes an unusable value for a command-line switch, it
     // seems like a really bad idea to just ignore it, even with a log
     // warning.
-    throw LLCLPError(STRINGIZE("Invalid value specified by command-line switch '" << option
-                               << "' for variable '" << varname << "' of type " << type
-                               << ": '" << value << "'"));
+    LLTHROW(LLCLPError(STRINGIZE("Invalid value specified by command-line switch '" << option
+                                 << "' for variable '" << varname << "' of type " << type
+                                 << ": '" << value << "'")));
 }
 
 template <typename T>
diff --git a/indra/newview/llsecapi.cpp b/indra/newview/llsecapi.cpp
index 4f9f83b6f2..933f7bb16e 100644
--- a/indra/newview/llsecapi.cpp
+++ b/indra/newview/llsecapi.cpp
@@ -29,6 +29,7 @@
 #include "llviewerprecompiledheaders.h"
 #include "llsecapi.h"
 #include "llsechandler_basic.h"
+#include "llexception.h"
 #include <openssl/evp.h>
 #include <openssl/err.h>
 #include <map>
@@ -64,12 +65,12 @@ void initializeSecHandler()
 		}
 		catch (LLProtectedDataException e)
 		{
-			exception_msg = e.getMessage();
+			exception_msg = e.what();
 		}
 	}
 	if (!exception_msg.empty())  // an exception was thrown.
 	{
-		throw LLProtectedDataException(exception_msg.c_str());
+		LLTHROW(LLProtectedDataException(exception_msg));
 	}
 
 }
diff --git a/indra/newview/llsecapi.h b/indra/newview/llsecapi.h
index 6fe3ee31cf..6af5a28fa5 100644
--- a/indra/newview/llsecapi.h
+++ b/indra/newview/llsecapi.h
@@ -32,6 +32,7 @@
 #include <openssl/x509.h>
 #include <ostream>
 #include "llpointer.h"
+#include "llexception.h"
 
 #ifdef LL_WINDOWS
 #pragma warning(disable:4250)
@@ -116,17 +117,13 @@
 
 
 
-class LLProtectedDataException
+struct LLProtectedDataException: public LLException
 {
-public:
-	LLProtectedDataException(const char *msg) 
+	LLProtectedDataException(const std::string& msg):
+		LLException(msg)
 	{
-		LL_WARNS("SECAPI") << "Protected Data Error: " << (std::string)msg << LL_ENDL;
-		mMsg = (std::string)msg;
+		LL_WARNS("SECAPI") << "Protected Data Error: " << msg << LL_ENDL;
 	}
-	std::string getMessage() { return mMsg; }
-protected:
-	std::string mMsg;
 };
 
 // class LLCertificate
@@ -334,22 +331,21 @@ std::ostream& operator <<(std::ostream& s, const LLCredential& cred);
 
 // All error handling is via exceptions.
 
-class LLCertException
+class LLCertException: public LLException
 {
 public:
-	LLCertException(LLPointer<LLCertificate> cert, const char* msg)
+	LLCertException(LLPointer<LLCertificate> cert, const std::string& msg):
+		LLException(msg)
 	{
 
 		mCert = cert;
 
-		LL_WARNS("SECAPI") << "Certificate Error: " << (std::string)msg << LL_ENDL;
-		mMsg = (std::string)msg;
+		LL_WARNS("SECAPI") << "Certificate Error: " << msg << LL_ENDL;
 	}
-	LLPointer<LLCertificate> getCert() { return mCert; }
-	std::string getMessage() { return mMsg; }
+	virtual ~LLCertException() throw() {}
+	LLPointer<LLCertificate> getCert() const { return mCert; }
 protected:
 	LLPointer<LLCertificate> mCert;
-	std::string mMsg;
 };
 
 class LLInvalidCertificate : public LLCertException
@@ -358,6 +354,7 @@ public:
 	LLInvalidCertificate(LLPointer<LLCertificate> cert) : LLCertException(cert, "CertInvalid")
 	{
 	}
+	virtual ~LLInvalidCertificate() throw() {}
 protected:
 };
 
@@ -367,6 +364,7 @@ public:
 	LLCertValidationTrustException(LLPointer<LLCertificate> cert) : LLCertException(cert, "CertUntrusted")
 	{
 	}
+	virtual ~LLCertValidationTrustException() throw() {}
 protected:
 };
 
@@ -378,7 +376,7 @@ public:
 	{
 		mHostname = hostname;
 	}
-	
+	virtual ~LLCertValidationHostnameException() throw() {}
 	std::string getHostname() { return mHostname; }
 protected:
 	std::string mHostname;
@@ -392,6 +390,7 @@ public:
 	{
 		mTime = current_time;
 	}
+	virtual ~LLCertValidationExpirationException() throw() {}
 	LLDate GetTime() { return mTime; }
 protected:
 	LLDate mTime;
@@ -403,6 +402,7 @@ public:
 	LLCertKeyUsageValidationException(LLPointer<LLCertificate> cert) : LLCertException(cert, "CertKeyUsage")
 	{
 	}
+	virtual ~LLCertKeyUsageValidationException() throw() {}
 protected:
 };
 
@@ -412,6 +412,7 @@ public:
 	LLCertBasicConstraintsValidationException(LLPointer<LLCertificate> cert) : LLCertException(cert, "CertBasicConstraints")
 	{
 	}
+	virtual ~LLCertBasicConstraintsValidationException() throw() {}
 protected:
 };
 
@@ -421,6 +422,7 @@ public:
 	LLCertValidationInvalidSignatureException(LLPointer<LLCertificate> cert) : LLCertException(cert, "CertInvalidSignature")
 	{
 	}
+	virtual ~LLCertValidationInvalidSignatureException() throw() {}
 protected:
 };
 
diff --git a/indra/newview/llsechandler_basic.cpp b/indra/newview/llsechandler_basic.cpp
index 40516f9bbb..183a625382 100644
--- a/indra/newview/llsechandler_basic.cpp
+++ b/indra/newview/llsechandler_basic.cpp
@@ -35,6 +35,7 @@
 #include "llfile.h"
 #include "lldir.h"
 #include "llviewercontrol.h"
+#include "llexception.h"
 #include <vector>
 #include <ios>
 #include <openssl/ossl_typ.h>
@@ -72,14 +73,14 @@ LLBasicCertificate::LLBasicCertificate(const std::string& pem_cert)
 	if(pem_bio == NULL)
 	{
 		LL_WARNS("SECAPI") << "Could not allocate an openssl memory BIO." << LL_ENDL;
-		throw LLInvalidCertificate(this);
+		LLTHROW(LLInvalidCertificate(this));
 	}
 	mCert = NULL;
 	PEM_read_bio_X509(pem_bio, &mCert, 0, NULL);
 	BIO_free(pem_bio);
 	if (!mCert)
 	{
-		throw LLInvalidCertificate(this);
+		LLTHROW(LLInvalidCertificate(this));
 	}
 }
 
@@ -88,7 +89,7 @@ LLBasicCertificate::LLBasicCertificate(X509* pCert)
 {
 	if (!pCert || !pCert->cert_info)
 	{
-		throw LLInvalidCertificate(this);
+		LLTHROW(LLInvalidCertificate(this));
 	}	
 	mCert = X509_dup(pCert);
 }
@@ -873,22 +874,22 @@ void _validateCert(int validation_policy,
 	// check basic properties exist in the cert
 	if(!current_cert_info.has(CERT_SUBJECT_NAME) || !current_cert_info.has(CERT_SUBJECT_NAME_STRING))
 	{
-		throw LLCertException(cert, "Cert doesn't have a Subject Name");				
+		LLTHROW(LLCertException(cert, "Cert doesn't have a Subject Name"));
 	}
 	
 	if(!current_cert_info.has(CERT_ISSUER_NAME_STRING))
 	{
-		throw LLCertException(cert, "Cert doesn't have an Issuer Name");				
+		LLTHROW(LLCertException(cert, "Cert doesn't have an Issuer Name"));
 	}
 	
 	// check basic properties exist in the cert
 	if(!current_cert_info.has(CERT_VALID_FROM) || !current_cert_info.has(CERT_VALID_TO))
 	{
-		throw LLCertException(cert, "Cert doesn't have an expiration period");				
+		LLTHROW(LLCertException(cert, "Cert doesn't have an expiration period"));
 	}
 	if (!current_cert_info.has(CERT_SHA1_DIGEST))
 	{
-		throw LLCertException(cert, "No SHA1 digest");
+		LLTHROW(LLCertException(cert, "No SHA1 digest"));
 	}
 
 	if (validation_policy & VALIDATION_POLICY_TIME)
@@ -903,7 +904,7 @@ void _validateCert(int validation_policy,
 		if((validation_date < current_cert_info[CERT_VALID_FROM].asDate()) ||
 		   (validation_date > current_cert_info[CERT_VALID_TO].asDate()))
 		{
-			throw LLCertValidationExpirationException(cert, validation_date);
+			LLTHROW(LLCertValidationExpirationException(cert, validation_date));
 		}
 	}
 	if (validation_policy & VALIDATION_POLICY_SSL_KU)
@@ -914,14 +915,14 @@ void _validateCert(int validation_policy,
 			!(_LLSDArrayIncludesValue(current_cert_info[CERT_KEY_USAGE], 
 									  LLSD((std::string)CERT_KU_KEY_ENCIPHERMENT)))))
 		{
-			throw LLCertKeyUsageValidationException(cert);
+			LLTHROW(LLCertKeyUsageValidationException(cert));
 		}
 		// only validate EKU if the cert has it
 		if(current_cert_info.has(CERT_EXTENDED_KEY_USAGE) && current_cert_info[CERT_EXTENDED_KEY_USAGE].isArray() &&	   
 		   (!_LLSDArrayIncludesValue(current_cert_info[CERT_EXTENDED_KEY_USAGE], 
 									LLSD((std::string)CERT_EKU_SERVER_AUTH))))
 		{
-			throw LLCertKeyUsageValidationException(cert);			
+			LLTHROW(LLCertKeyUsageValidationException(cert));
 		}
 	}
 	if (validation_policy & VALIDATION_POLICY_CA_KU)
@@ -930,7 +931,7 @@ void _validateCert(int validation_policy,
 			(!_LLSDArrayIncludesValue(current_cert_info[CERT_KEY_USAGE], 
 									   (std::string)CERT_KU_CERT_SIGN)))
 			{
-				throw LLCertKeyUsageValidationException(cert);						
+				LLTHROW(LLCertKeyUsageValidationException(cert));
 			}
 	}
 	
@@ -942,13 +943,13 @@ void _validateCert(int validation_policy,
 		if(!current_cert_info[CERT_BASIC_CONSTRAINTS].has(CERT_BASIC_CONSTRAINTS_CA) ||
 		   !current_cert_info[CERT_BASIC_CONSTRAINTS][CERT_BASIC_CONSTRAINTS_CA])
 		{
-				throw LLCertBasicConstraintsValidationException(cert);
+				LLTHROW(LLCertBasicConstraintsValidationException(cert));
 		}
 		if (current_cert_info[CERT_BASIC_CONSTRAINTS].has(CERT_BASIC_CONSTRAINTS_PATHLEN) &&
 			((current_cert_info[CERT_BASIC_CONSTRAINTS][CERT_BASIC_CONSTRAINTS_PATHLEN].asInteger() != 0) &&
 			 (depth > current_cert_info[CERT_BASIC_CONSTRAINTS][CERT_BASIC_CONSTRAINTS_PATHLEN].asInteger())))
 		{
-			throw LLCertBasicConstraintsValidationException(cert);					
+			LLTHROW(LLCertBasicConstraintsValidationException(cert));
 		}
 	}
 }
@@ -1018,7 +1019,7 @@ void LLBasicCertificateStore::validate(int validation_policy,
 
 	if(cert_chain->size() < 1)
 	{
-		throw LLCertException(NULL, "No certs in chain");
+		LLTHROW(LLCertException(NULL, "No certs in chain"));
 	}
 	iterator current_cert = cert_chain->begin();
 	LLSD 	current_cert_info;
@@ -1033,11 +1034,11 @@ void LLBasicCertificateStore::validate(int validation_policy,
 		(*current_cert)->getLLSD(current_cert_info);
 		if(!validation_params.has(CERT_HOSTNAME))
 		{
-			throw LLCertException((*current_cert), "No hostname passed in for validation");			
+			LLTHROW(LLCertException((*current_cert), "No hostname passed in for validation"));
 		}
 		if(!current_cert_info.has(CERT_SUBJECT_NAME) || !current_cert_info[CERT_SUBJECT_NAME].has(CERT_NAME_CN))
 		{
-			throw LLInvalidCertificate((*current_cert));				
+			LLTHROW(LLInvalidCertificate((*current_cert)));
 		}
 		
 		LL_DEBUGS("SECAPI") << "Validating the hostname " << validation_params[CERT_HOSTNAME].asString() << 
@@ -1054,7 +1055,7 @@ void LLBasicCertificateStore::validate(int validation_policy,
 	X509* cert_x509 = (*current_cert)->getOpenSSLX509();
 	if(!cert_x509)
 	{
-		throw LLInvalidCertificate((*current_cert));			
+		LLTHROW(LLInvalidCertificate((*current_cert)));
 	}
 	std::string sha1_hash((const char *)cert_x509->sha1_hash, SHA_DIGEST_LENGTH);
 	X509_free( cert_x509 );
@@ -1075,7 +1076,7 @@ void LLBasicCertificateStore::validate(int validation_policy,
 			if((validation_date < cache_entry->second.first) ||
 			   (validation_date > cache_entry->second.second))
 			{
-				throw LLCertValidationExpirationException((*current_cert), validation_date);
+				LLTHROW(LLCertValidationExpirationException((*current_cert), validation_date));
 			}
 		}
 		// successfully found in cache
@@ -1107,7 +1108,7 @@ void LLBasicCertificateStore::validate(int validation_policy,
 			if(!_verify_signature((*current_cert),
 								  previous_cert))
 			{
-			   throw LLCertValidationInvalidSignatureException(previous_cert);
+			   LLTHROW(LLCertValidationInvalidSignatureException(previous_cert));
 			}
 		}
 		_validateCert(local_validation_policy,
@@ -1156,7 +1157,7 @@ void LLBasicCertificateStore::validate(int validation_policy,
 			if(!_verify_signature((*found_store_cert),
 								  (*current_cert)))
 			{
-				throw LLCertValidationInvalidSignatureException(*current_cert);
+				LLTHROW(LLCertValidationInvalidSignatureException(*current_cert));
 			}			
 			// successfully validated.
 			mTrustedCertCache[sha1_hash] = std::pair<LLDate, LLDate>(from_time, to_time);		
@@ -1173,7 +1174,7 @@ void LLBasicCertificateStore::validate(int validation_policy,
 	if (validation_policy & VALIDATION_POLICY_TRUSTED)
 	{
 		// we reached the end without finding a trusted cert.
-		throw LLCertValidationTrustException((*cert_chain)[cert_chain->size()-1]);
+		LLTHROW(LLCertValidationTrustException((*cert_chain)[cert_chain->size()-1]));
 
 	}
 	mTrustedCertCache[sha1_hash] = std::pair<LLDate, LLDate>(from_time, to_time);	
@@ -1261,7 +1262,7 @@ void LLSecAPIBasicHandler::_readProtectedData()
 		protected_data_stream.read((char *)salt, STORE_SALT_SIZE);
 		if (protected_data_stream.gcount() < STORE_SALT_SIZE)
 		{
-			throw LLProtectedDataException("Config file too short.");
+			LLTHROW(LLProtectedDataException("Config file too short."));
 		}
 
 		cipher.decrypt(salt, STORE_SALT_SIZE);		
@@ -1301,7 +1302,7 @@ void LLSecAPIBasicHandler::_readProtectedData()
 		if (parser->parse(parse_stream, mProtectedDataMap, 
 						  LLSDSerialize::SIZE_UNLIMITED) == LLSDParser::PARSE_FAILURE)
 		{
-			throw LLProtectedDataException("Config file cannot be decrypted.");
+			LLTHROW(LLProtectedDataException("Config file cannot be decrypted."));
 		}
 	}
 }
@@ -1372,7 +1373,7 @@ void LLSecAPIBasicHandler::_writeProtectedData()
 
 		// EXP-1825 crash in LLSecAPIBasicHandler::_writeProtectedData()
 		// Decided throwing an exception here was overkill until we figure out why this happens
-		//throw LLProtectedDataException("Error writing Protected Data Store");
+		//LLTHROW(LLProtectedDataException("Error writing Protected Data Store"));
 	}
 
     try
@@ -1387,7 +1388,7 @@ void LLSecAPIBasicHandler::_writeProtectedData()
 
             // EXP-1825 crash in LLSecAPIBasicHandler::_writeProtectedData()
             // Decided throwing an exception here was overkill until we figure out why this happens
-            //throw LLProtectedDataException("Could not overwrite protected data store");
+            //LLTHROW(LLProtectedDataException("Could not overwrite protected data store"));
         }
 	}
 	catch (...)
@@ -1401,7 +1402,7 @@ void LLSecAPIBasicHandler::_writeProtectedData()
 
 		//crash in LLSecAPIBasicHandler::_writeProtectedData()
 		// Decided throwing an exception here was overkill until we figure out why this happens
-		//throw LLProtectedDataException("Error writing Protected Data Store");
+		//LLTHROW(LLProtectedDataException("Error writing Protected Data Store"));
 	}
 }
 		
diff --git a/indra/test/llapp_tut.cpp b/indra/test/llapp_tut.cpp
index aa5c0672e6..98e714a497 100644
--- a/indra/test/llapp_tut.cpp
+++ b/indra/test/llapp_tut.cpp
@@ -41,7 +41,7 @@ namespace tut
 		public:
 			virtual bool init() { return true; }
 			virtual bool cleanup() { return true; }
-			virtual bool mainLoop() { return true; }
+			virtual bool frame() { return true; }
 		};
 		LLTestApp* mApp;
 		application()
diff --git a/indra/viewer_components/updater/llupdatedownloader.cpp b/indra/viewer_components/updater/llupdatedownloader.cpp
index 382689afa0..04e0395c50 100644
--- a/indra/viewer_components/updater/llupdatedownloader.cpp
+++ b/indra/viewer_components/updater/llupdatedownloader.cpp
@@ -27,7 +27,7 @@
 
 #include "llupdatedownloader.h"
 #include "httpcommon.h"
-#include <stdexcept>
+#include "llexception.h"
 #include <boost/format.hpp>
 #include <boost/lexical_cast.hpp>
 #include <curl/curl.h>
@@ -85,11 +85,11 @@ private:
 
 namespace {
 	class DownloadError:
-		public std::runtime_error
+		public LLException
 	{
 	public:
 		DownloadError(const char * message):
-			std::runtime_error(message)
+			LLException(message)
 		{
 			; // No op.
 		}
@@ -467,7 +467,7 @@ void LLUpdateDownloader::Implementation::initializeCurlGet(std::string const & u
 
 	if(!mCurl)
 	{
-		throw DownloadError("failed to initialize curl");
+		LLTHROW(DownloadError("failed to initialize curl"));
 	}
     throwOnCurlError(curl_easy_setopt(mCurl.get(), CURLOPT_NOSIGNAL, true));
 	throwOnCurlError(curl_easy_setopt(mCurl.get(), CURLOPT_FOLLOWLOCATION, true));
@@ -508,7 +508,7 @@ void LLUpdateDownloader::Implementation::resumeDownloading(size_t startByte)
 	mHeaderList = curl_slist_append(mHeaderList, rangeHeaderFormat.str().c_str());
 	if(mHeaderList == 0)
 	{
-		throw DownloadError("cannot add Range header");
+		LLTHROW(DownloadError("cannot add Range header"));
 	}
 	throwOnCurlError(curl_easy_setopt(mCurl.get(), CURLOPT_HTTPHEADER, mHeaderList));
 
@@ -524,7 +524,7 @@ void LLUpdateDownloader::Implementation::startDownloading(LLURI const & uri, std
 	mDownloadData["hash"] = hash;
 	mDownloadData["current_version"] = ll_get_version();
 	LLSD path = uri.pathArray();
-	if(path.size() == 0) throw DownloadError("no file path");
+	if(path.size() == 0) LLTHROW(DownloadError("no file path"));
 	std::string fileName = path[path.size() - 1].asString();
 	std::string filePath = gDirUtilp->getExpandedFilename(LL_PATH_TEMP, fileName);
 	mDownloadData["path"] = filePath;
@@ -547,9 +547,9 @@ void LLUpdateDownloader::Implementation::throwOnCurlError(CURLcode code)
 	if(code != CURLE_OK) {
 		const char * errorString = curl_easy_strerror(code);
 		if(errorString != 0) {
-			throw DownloadError(curl_easy_strerror(code));
+			LLTHROW(DownloadError(curl_easy_strerror(code)));
 		} else {
-			throw DownloadError("unknown curl error");
+			LLTHROW(DownloadError("unknown curl error"));
 		}
 	} else {
 		; // No op.
diff --git a/indra/viewer_components/updater/llupdateinstaller.cpp b/indra/viewer_components/updater/llupdateinstaller.cpp
index a0e2c0b362..1c7629da23 100644
--- a/indra/viewer_components/updater/llupdateinstaller.cpp
+++ b/indra/viewer_components/updater/llupdateinstaller.cpp
@@ -30,23 +30,25 @@
 #include "llupdateinstaller.h"
 #include "lldir.h" 
 #include "llsd.h"
+#include "llexception.h"
 
 #if defined(LL_WINDOWS)
 #pragma warning(disable: 4702)      // disable 'unreachable code' so we can use lexical_cast (really!).
 #endif
 #include <boost/lexical_cast.hpp>
 
-
 namespace {
-	class RelocateError {};
-	
-	
+	struct RelocateError: public LLException
+	{
+		RelocateError(): LLException("llupdateinstaller: RelocateError") {}
+	};
+
 	std::string copy_to_temp(std::string const & path)
 	{
 		std::string scriptFile = gDirUtilp->getBaseFileName(path);
 		std::string newPath = gDirUtilp->getExpandedFilename(LL_PATH_TEMP, scriptFile);
 		apr_status_t status = apr_file_copy(path.c_str(), newPath.c_str(), APR_FILE_SOURCE_PERMS, gAPRPoolp);
-		if(status != APR_SUCCESS) throw RelocateError();
+		if(status != APR_SUCCESS) LLTHROW(RelocateError());
 		
 		return newPath;
 	}
diff --git a/indra/viewer_components/updater/llupdaterservice.cpp b/indra/viewer_components/updater/llupdaterservice.cpp
index 788955a1b2..1665e41e70 100644
--- a/indra/viewer_components/updater/llupdaterservice.cpp
+++ b/indra/viewer_components/updater/llupdaterservice.cpp
@@ -32,6 +32,7 @@
 #include "lltimer.h"
 #include "llupdatechecker.h"
 #include "llupdateinstaller.h"
+#include "llexception.h"
 
 #include <boost/scoped_ptr.hpp>
 #include <boost/weak_ptr.hpp>
@@ -190,8 +191,8 @@ void LLUpdaterServiceImpl::initialize(const std::string&  channel,
 {
 	if(mIsChecking || mIsDownloading)
 	{
-		throw LLUpdaterService::UsageError("LLUpdaterService::initialize call "
-										   "while updater is running.");
+		LLTHROW(LLUpdaterService::UsageError("LLUpdaterService::initialize call "
+											  "while updater is running."));
 	}
 		
 	mChannel = channel;
@@ -222,8 +223,8 @@ void LLUpdaterServiceImpl::startChecking(bool install_if_ready)
 {
 	if(mChannel.empty() || mVersion.empty())
 	{
-		throw LLUpdaterService::UsageError("Set params before call to "
-			"LLUpdaterService::startCheck().");
+		LLTHROW(LLUpdaterService::UsageError("Set params before call to "
+											 "LLUpdaterService::startCheck()."));
 	}
 
 	mIsChecking = true;
diff --git a/indra/viewer_components/updater/llupdaterservice.h b/indra/viewer_components/updater/llupdaterservice.h
index 95bbe1695c..78e8c6b290 100644
--- a/indra/viewer_components/updater/llupdaterservice.h
+++ b/indra/viewer_components/updater/llupdaterservice.h
@@ -29,16 +29,17 @@
 #include <boost/shared_ptr.hpp>
 #include <boost/function.hpp>
 #include "llhasheduniqueid.h"
+#include "llexception.h"
 
 class LLUpdaterServiceImpl;
 
 class LLUpdaterService
 {
 public:
-	class UsageError: public std::runtime_error
+	class UsageError: public LLException
 	{
 	public:
-		UsageError(const std::string& msg) : std::runtime_error(msg) {}
+		UsageError(const std::string& msg) : LLException(msg) {}
 	};
 	
 	// Name of the event pump through which update events will be delivered.
diff --git a/indra/win_crash_logger/llcrashloggerwindows.cpp b/indra/win_crash_logger/llcrashloggerwindows.cpp
index 23c29e6b18..167acf6ac7 100644
--- a/indra/win_crash_logger/llcrashloggerwindows.cpp
+++ b/indra/win_crash_logger/llcrashloggerwindows.cpp
@@ -454,7 +454,7 @@ void LLCrashLoggerWindows::gatherPlatformSpecificFiles()
 	//mDebugLog["DisplayDeviceInfo"] = gDXHardware.getDisplayInfo();  //Not initialized.
 }
 
-bool LLCrashLoggerWindows::mainLoop()
+bool LLCrashLoggerWindows::frame()
 {	
 	LL_INFOS() << "CrashSubmitBehavior is " << mCrashBehavior << LL_ENDL;
 
@@ -503,14 +503,14 @@ bool LLCrashLoggerWindows::mainLoop()
 			TranslateMessage(&msg);
 			DispatchMessage(&msg);
 		}
-		return msg.wParam;
+		return true; // msg.wParam;
 	}
 	else
 	{
 		LL_WARNS() << "Unknown crash behavior " << mCrashBehavior << LL_ENDL;
-		return 1;
+		return true; // 1;
 	}
-	return 0;
+	return true; // 0;
 }
 
 void LLCrashLoggerWindows::updateApplication(const std::string& message)
diff --git a/indra/win_crash_logger/llcrashloggerwindows.h b/indra/win_crash_logger/llcrashloggerwindows.h
index 1812e2737e..f89b8708dc 100644
--- a/indra/win_crash_logger/llcrashloggerwindows.h
+++ b/indra/win_crash_logger/llcrashloggerwindows.h
@@ -46,7 +46,7 @@ public:
 	static LLCrashLoggerWindows* sInstance; 
 
 	virtual bool init();
-	virtual bool mainLoop();
+	virtual bool frame();
 	virtual void updateApplication(const std::string& message = LLStringUtil::null);
 	virtual bool cleanup();
 	virtual void gatherPlatformSpecificFiles();
diff --git a/indra/win_crash_logger/win_crash_logger.cpp b/indra/win_crash_logger/win_crash_logger.cpp
index 366edd894b..7466dbb766 100644
--- a/indra/win_crash_logger/win_crash_logger.cpp
+++ b/indra/win_crash_logger/win_crash_logger.cpp
@@ -52,7 +52,7 @@ int APIENTRY WinMain(HINSTANCE hInstance,
 	}
 
 	app.processingLoop();
-	app.mainLoop();
+	app.frame();
 	app.cleanup();
 	LL_INFOS() << "Crash reporter finished normally." << LL_ENDL;
 	return 0;