diff --git a/desmume/src/GPU.cpp b/desmume/src/GPU.cpp
index 5be104c0a..65f24fa9d 100644
--- a/desmume/src/GPU.cpp
+++ b/desmume/src/GPU.cpp
@@ -723,7 +723,7 @@ void GPUEngineBase::_RenderLine_Clear(const u16 clearColor, const u16 l, u16 *ds
 }
 
 template<bool ISCUSTOMRENDERINGNEEDED>
-void GPUEngineBase::RenderLine(const u16 l, bool isFrameSkipRequested)
+void GPUEngineBase::RenderLine(const u16 l)
 {
 	
 }
@@ -2710,7 +2710,7 @@ void GPUEngineA::SetCustomFramebufferSize(size_t w, size_t h)
 }
 
 template<bool ISCUSTOMRENDERINGNEEDED>
-void GPUEngineA::RenderLine(const u16 l, bool isFrameSkipRequested)
+void GPUEngineA::RenderLine(const u16 l)
 {
 	const NDSDisplayInfo &dispInfo = GPU->GetDisplayInfo();
 	const size_t dstLineWidth = (ISCUSTOMRENDERINGNEEDED) ? dispInfo.customWidth : GPU_FRAMEBUFFER_NATIVE_WIDTH;
@@ -3808,6 +3808,9 @@ void GPUEngineB::_RenderLine_Layer(const u16 l, u16 *dstColorLine, const size_t
 
 GPUSubsystem::GPUSubsystem()
 {
+	_defaultEventHandler = new GPUEventHandlerDefault;
+	_event = _defaultEventHandler;
+	
 	gfx3d_init();
 	
 	_engineMain = GPUEngineA::Allocate();
@@ -3867,6 +3870,8 @@ GPUSubsystem::~GPUSubsystem()
 	_engineSub->FinalizeAndDeallocate();
 	
 	gfx3d_deinit();
+	
+	delete _defaultEventHandler;
 }
 
 GPUSubsystem* GPUSubsystem::Allocate()
@@ -3880,6 +3885,16 @@ void GPUSubsystem::FinalizeAndDeallocate()
 	free_aligned(this);
 }
 
+void GPUSubsystem::SetEventHandler(GPUEventHandler *eventHandler)
+{
+	this->_event = eventHandler;
+}
+
+GPUEventHandler* GPUSubsystem::GetEventHandler()
+{
+	return this->_event;
+}
+
 void GPUSubsystem::Reset()
 {
 	if (this->_customVRAM == NULL || this->_customVRAM == NULL || this->_customFramebuffer == NULL)
@@ -4184,6 +4199,7 @@ void GPUSubsystem::RenderLine(const u16 l, bool isFrameSkipRequested)
 	if (l == 0)
 	{
 		CurrentRenderer->RenderFinish();
+		this->_event->DidFrameBegin();
 		this->UpdateVRAM3DUsageProperties();
 		
 		// Clear displays to black if they are turned off by the user.
@@ -4215,11 +4231,11 @@ void GPUSubsystem::RenderLine(const u16 l, bool isFrameSkipRequested)
 		{
 			if (this->_engineMain->isCustomRenderingNeeded)
 			{
-				this->_engineMain->RenderLine<true>(l, isFrameSkipRequested);
+				this->_engineMain->RenderLine<true>(l);
 			}
 			else
 			{
-				this->_engineMain->RenderLine<false>(l, isFrameSkipRequested);
+				this->_engineMain->RenderLine<false>(l);
 			}
 		}
 		
@@ -4249,16 +4265,17 @@ void GPUSubsystem::RenderLine(const u16 l, bool isFrameSkipRequested)
 			{
 				this->_engineSub->ApplyMasterBrightness<false>();
 			}
-		}
-		
-		if (this->_willAutoResolveToCustomBuffer)
-		{
-			this->_engineMain->ResolveToCustomFramebuffer();
-			this->_engineSub->ResolveToCustomFramebuffer();
+			
+			if (this->_willAutoResolveToCustomBuffer)
+			{
+				this->_engineMain->ResolveToCustomFramebuffer();
+				this->_engineSub->ResolveToCustomFramebuffer();
+			}
 		}
 		
 		this->_engineMain->FramebufferPostprocess();
 		this->_engineSub->FramebufferPostprocess();
+		this->_event->DidFrameEnd(isFrameSkipRequested);
 	}
 }
 
diff --git a/desmume/src/GPU.h b/desmume/src/GPU.h
index 85558e8c8..70282d0fe 100644
--- a/desmume/src/GPU.h
+++ b/desmume/src/GPU.h
@@ -1229,7 +1229,7 @@ public:
 	
 	template<GPUEngineID ENGINEID> void ParseAllRegisters();
 	
-	template<bool ISCUSTOMRENDERINGNEEDED> void RenderLine(const u16 l, bool isFrameSkipRequested);
+	template<bool ISCUSTOMRENDERINGNEEDED> void RenderLine(const u16 l);
 	void FramebufferPostprocess();
 	
 	bool isCustomRenderingNeeded;
@@ -1337,7 +1337,7 @@ public:
 	
 	template<GPULayerID LAYERID, bool ISDEBUGRENDER, bool MOSAIC, bool ISCUSTOMRENDERINGNEEDED> void _LineLarge8bpp(u16 *dstColorLine, const u16 lineIndex);
 		
-	template<bool ISCUSTOMRENDERINGNEEDED> void RenderLine(const u16 l, bool isFrameSkipRequested);
+	template<bool ISCUSTOMRENDERINGNEEDED> void RenderLine(const u16 l);
 	void FramebufferPostprocess();
 };
 
@@ -1376,12 +1376,36 @@ public:
 	void SetEngineByID(const GPUEngineID theID);
 };
 
+class GPUEventHandler
+{
+public:
+	virtual void DidFrameBegin() = 0;
+	virtual void DidFrameEnd(bool isFrameSkipped) = 0;
+	virtual void DidRender3DBegin() = 0;
+	virtual void DidRender3DEnd() = 0;
+};
+
+// All of the default event handler methods should do nothing.
+// If a subclass doesn't need to override every method, then it might be easier
+// if you subclass GPUEventHandlerDefault instead of GPUEventHandler.
+class GPUEventHandlerDefault : public GPUEventHandler
+{
+public:
+	virtual void DidFrameBegin() {};
+	virtual void DidFrameEnd(bool isFrameSkipped) {};
+	virtual void DidRender3DBegin() {};
+	virtual void DidRender3DEnd() {};
+};
+
 class GPUSubsystem
 {
 private:
 	GPUSubsystem();
 	~GPUSubsystem();
 	
+	GPUEventHandlerDefault *_defaultEventHandler;
+	GPUEventHandler *_event;
+	
 	GPUEngineA *_engineMain;
 	GPUEngineB *_engineSub;
 	NDSDisplay *_displayMain;
@@ -1401,6 +1425,9 @@ public:
 	static GPUSubsystem* Allocate();
 	void FinalizeAndDeallocate();
 	
+	void SetEventHandler(GPUEventHandler *eventHandler);
+	GPUEventHandler* GetEventHandler();
+	
 	void Reset();
 	VRAM3DUsageProperties& GetVRAM3DUsageProperties();
 	const NDSDisplayInfo& GetDisplayInfo(); // Frontends need to call this whenever they need to read the video buffers from the emulator core
diff --git a/desmume/src/OGLRender.cpp b/desmume/src/OGLRender.cpp
index 75c4f1050..69017f0dc 100644
--- a/desmume/src/OGLRender.cpp
+++ b/desmume/src/OGLRender.cpp
@@ -2720,11 +2720,13 @@ Render3DError OpenGLRenderer_1_2::RenderFinish()
 {
 	if (!this->_pixelReadNeedsFinish)
 	{
+		GPU->GetEventHandler()->DidRender3DEnd();
 		return OGLERROR_NOERR;
 	}
 	
 	if(!BEGINGL())
 	{
+		GPU->GetEventHandler()->DidRender3DEnd();
 		return OGLERROR_BEGINGL_FAILED;
 	}
 	
@@ -2747,6 +2749,7 @@ Render3DError OpenGLRenderer_1_2::RenderFinish()
 	this->FlushFramebuffer(GPU->GetEngineMain()->Get3DFramebufferRGBA6665(), GPU->GetEngineMain()->Get3DFramebufferRGBA5551());
 	this->_pixelReadNeedsFinish = false;
 	
+	GPU->GetEventHandler()->DidRender3DEnd();
 	return OGLERROR_NOERR;
 }
 
@@ -3287,11 +3290,13 @@ Render3DError OpenGLRenderer_1_5::RenderFinish()
 {
 	if (!this->_pixelReadNeedsFinish)
 	{
+		GPU->GetEventHandler()->DidRender3DEnd();
 		return OGLERROR_NOERR;
 	}
 	
 	if(!BEGINGL())
 	{
+		GPU->GetEventHandler()->DidRender3DEnd();
 		return OGLERROR_BEGINGL_FAILED;
 	}
 	
@@ -3314,6 +3319,7 @@ Render3DError OpenGLRenderer_1_5::RenderFinish()
 	this->FlushFramebuffer(GPU->GetEngineMain()->Get3DFramebufferRGBA6665(), GPU->GetEngineMain()->Get3DFramebufferRGBA5551());
 	this->_pixelReadNeedsFinish = false;
 	
+	GPU->GetEventHandler()->DidRender3DEnd();
 	return OGLERROR_NOERR;
 }
 
@@ -4077,11 +4083,13 @@ Render3DError OpenGLRenderer_2_1::RenderFinish()
 {
 	if (!this->_pixelReadNeedsFinish)
 	{
+		GPU->GetEventHandler()->DidRender3DEnd();
 		return OGLERROR_NOERR;
 	}
 	
 	if(!BEGINGL())
 	{
+		GPU->GetEventHandler()->DidRender3DEnd();
 		return OGLERROR_BEGINGL_FAILED;
 	}
 	
@@ -4097,5 +4105,6 @@ Render3DError OpenGLRenderer_2_1::RenderFinish()
 	this->FlushFramebuffer(GPU->GetEngineMain()->Get3DFramebufferRGBA6665(), GPU->GetEngineMain()->Get3DFramebufferRGBA5551());
 	this->_pixelReadNeedsFinish = false;
 	
+	GPU->GetEventHandler()->DidRender3DEnd();
 	return OGLERROR_NOERR;
 }
diff --git a/desmume/src/cocoa/cocoa_GPU.h b/desmume/src/cocoa/cocoa_GPU.h
index 97f47990b..9c68b3ea4 100644
--- a/desmume/src/cocoa/cocoa_GPU.h
+++ b/desmume/src/cocoa/cocoa_GPU.h
@@ -19,6 +19,9 @@
 #include <pthread.h>
 #include <libkern/OSAtomic.h>
 
+
+class GPUEventHandlerOSX;
+
 @interface CocoaDSGPU : NSObject
 {
 	UInt32 gpuStateFlags;
@@ -26,13 +29,14 @@
 	BOOL isCPUCoreCountAuto;
 	
 	OSSpinLock spinlockGpuState;
-	pthread_rwlock_t *rwlockProducer;
+	GPUEventHandlerOSX *gpuEvent;
 }
 
 @property (assign) UInt32 gpuStateFlags;
 @property (assign) NSSize gpuDimensions;
 @property (assign) NSUInteger gpuScale;
-@property (assign) pthread_rwlock_t *rwlockProducer;
+@property (readonly) pthread_rwlock_t *gpuFrameRWLock;
+@property (assign) NSMutableArray *outputList;
 
 @property (assign) BOOL layerMainGPU;
 @property (assign) BOOL layerMainBG0;
diff --git a/desmume/src/cocoa/cocoa_GPU.mm b/desmume/src/cocoa/cocoa_GPU.mm
index e9b051bb7..65822df19 100644
--- a/desmume/src/cocoa/cocoa_GPU.mm
+++ b/desmume/src/cocoa/cocoa_GPU.mm
@@ -16,6 +16,7 @@
  */
 
 #import "cocoa_GPU.h"
+#import "cocoa_output.h"
 #import "cocoa_globals.h"
 #include "utilities.h"
 
@@ -40,12 +41,41 @@ GPU3DInterface *core3DList[] = {
 	NULL
 };
 
+class GPUEventHandlerOSX : public GPUEventHandlerDefault
+{
+private:
+	pthread_rwlock_t _rwlockFrame;
+	pthread_mutex_t _mutex3DRender;
+	NSMutableArray *_cdsOutputList;
+	bool _isRender3DLockHeld;
+	
+public:
+	GPUEventHandlerOSX();
+	~GPUEventHandlerOSX();
+	
+	void FramebufferLockWrite();
+	void FramebufferLockRead();
+	void FramebufferUnlock();
+	void Render3DLock();
+	void Render3DUnlock();
+	
+	pthread_rwlock_t* GetFrameRWLock();
+	NSMutableArray* GetOutputList();
+	void SetOutputList(NSMutableArray *outputList);
+	
+	virtual void DidFrameBegin();
+	virtual void DidFrameEnd(bool isFrameSkipped);
+	virtual void DidRender3DBegin();
+	virtual void DidRender3DEnd();
+};
+
 @implementation CocoaDSGPU
 
 @dynamic gpuStateFlags;
 @dynamic gpuDimensions;
 @dynamic gpuScale;
-@synthesize rwlockProducer;
+@dynamic gpuFrameRWLock;
+@dynamic outputList;
 
 @dynamic layerMainGPU;
 @dynamic layerMainBG0;
@@ -81,7 +111,6 @@ GPU3DInterface *core3DList[] = {
 	}
 	
 	spinlockGpuState = OS_SPINLOCK_INIT;
-	rwlockProducer = NULL;
 	
 	_gpuScale = 1;
 	gpuStateFlags	= GPUSTATE_MAIN_GPU_MASK |
@@ -104,6 +133,8 @@ GPU3DInterface *core3DList[] = {
 							   &OSXOpenGLRendererEnd,
 							   &OSXOpenGLRendererFramebufferDidResize);
 	
+	gpuEvent = new GPUEventHandlerOSX;
+	GPU->SetEventHandler(gpuEvent);
 	GPU->SetWillAutoResolveToCustomBuffer(false);
 	
 	return self;
@@ -114,6 +145,8 @@ GPU3DInterface *core3DList[] = {
 	NDS_3D_ChangeCore(CORE3DLIST_NULL);
 	DestroyOpenGLRenderer();
 	
+	delete gpuEvent;
+	
 	[super dealloc];
 }
 
@@ -149,16 +182,20 @@ GPU3DInterface *core3DList[] = {
 
 - (void) setGpuDimensions:(NSSize)theDimensions
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	gpuEvent->Render3DLock();
 	GPU->SetCustomFramebufferSize(theDimensions.width, theDimensions.height);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
+	gpuEvent->FramebufferUnlock();
 }
 
 - (NSSize) gpuDimensions
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	gpuEvent->Render3DLock();
 	const NSSize dimensions = NSMakeSize(GPU->GetCustomFramebufferWidth(), GPU->GetCustomFramebufferHeight());
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
+	gpuEvent->FramebufferUnlock();
 	
 	return dimensions;
 }
@@ -174,98 +211,113 @@ GPU3DInterface *core3DList[] = {
 	return (NSUInteger)_gpuScale;
 }
 
+- (pthread_rwlock_t *) gpuFrameRWLock
+{
+	return gpuEvent->GetFrameRWLock();
+}
+
+- (void) setOutputList:(NSMutableArray *)outputList
+{
+	gpuEvent->SetOutputList(outputList);
+}
+
+- (NSMutableArray *) outputList
+{
+	return gpuEvent->GetOutputList();
+}
+
 - (void) setRender3DRenderingEngine:(NSInteger)methodID
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	NDS_3D_ChangeCore(methodID);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (NSInteger) render3DRenderingEngine
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const NSInteger methodID = (NSInteger)cur3DCore;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return methodID;
 }
 
 - (void) setRender3DHighPrecisionColorInterpolation:(BOOL)state
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	CommonSettings.GFX3D_HighResolutionInterpolateColor = state ? true : false;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (BOOL) render3DHighPrecisionColorInterpolation
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const BOOL state = CommonSettings.GFX3D_HighResolutionInterpolateColor ? YES : NO;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return state;
 }
 
 - (void) setRender3DEdgeMarking:(BOOL)state
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	CommonSettings.GFX3D_EdgeMark = state ? true : false;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (BOOL) render3DEdgeMarking
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const BOOL state = CommonSettings.GFX3D_EdgeMark ? YES : NO;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return state;
 }
 
 - (void) setRender3DFog:(BOOL)state
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	CommonSettings.GFX3D_Fog = state ? true : false;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (BOOL) render3DFog
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const BOOL state = CommonSettings.GFX3D_Fog ? YES : NO;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return state;
 }
 
 - (void) setRender3DTextures:(BOOL)state
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	CommonSettings.GFX3D_Texture = state ? true : false;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (BOOL) render3DTextures
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const BOOL state = CommonSettings.GFX3D_Texture ? YES : NO;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return state;
 }
 
 - (void) setRender3DDepthComparisonThreshold:(NSUInteger)threshold
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	CommonSettings.GFX3D_Zelda_Shadow_Depth_Hack = threshold;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (NSUInteger) render3DDepthComparisonThreshold
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const NSUInteger threshold = (NSUInteger)CommonSettings.GFX3D_Zelda_Shadow_Depth_Hack;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return threshold;
 }
@@ -302,7 +354,7 @@ GPU3DInterface *core3DList[] = {
 	
 	const NSInteger renderingEngineID = [self render3DRenderingEngine];
 	
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	
 	CommonSettings.num_cores = numberCores;
 	
@@ -311,71 +363,71 @@ GPU3DInterface *core3DList[] = {
 		NDS_3D_ChangeCore(renderingEngineID);
 	}
 	
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (NSUInteger) render3DThreads
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const NSUInteger numberThreads = isCPUCoreCountAuto ? 0 : (NSUInteger)CommonSettings.num_cores;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return numberThreads;
 }
 
 - (void) setRender3DLineHack:(BOOL)state
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	CommonSettings.GFX3D_LineHack = state ? true : false;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (BOOL) render3DLineHack
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const BOOL state = CommonSettings.GFX3D_LineHack ? YES : NO;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return state;
 }
 
 - (void) setRender3DMultisample:(BOOL)state
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	CommonSettings.GFX3D_Renderer_Multisample = state ? true : false;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (BOOL) render3DMultisample
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const BOOL state = CommonSettings.GFX3D_Renderer_Multisample ? YES : NO;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return state;
 }
 
 - (void) setRender3DFragmentSamplingHack:(BOOL)state
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	CommonSettings.GFX3D_TXTHack = state ? true : false;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 }
 
 - (BOOL) render3DFragmentSamplingHack
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	const BOOL state = CommonSettings.GFX3D_TXTHack ? YES : NO;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return state;
 }
 
 - (void) setLayerMainGPU:(BOOL)gpuState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
 	GPU->GetEngineMain()->SetEnableState((gpuState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (gpuState) ? (gpuStateFlags | GPUSTATE_MAIN_GPU_MASK) : (gpuStateFlags & ~GPUSTATE_MAIN_GPU_MASK);
@@ -384,18 +436,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerMainGPU
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
 	const BOOL gpuState = GPU->GetEngineMain()->GetEnableState() ? YES : NO;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferUnlock();
 	
 	return gpuState;
 }
 
 - (void) setLayerMainBG0:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineMain()->SetLayerEnableState(0, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineMain()->SetLayerEnableState(GPULayerID_BG0, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_MAIN_BG0_MASK) : (gpuStateFlags & ~GPUSTATE_MAIN_BG0_MASK);
@@ -404,18 +456,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerMainBG0
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(0);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(GPULayerID_BG0);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
 
 - (void) setLayerMainBG1:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineMain()->SetLayerEnableState(1, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineMain()->SetLayerEnableState(GPULayerID_BG1, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_MAIN_BG1_MASK) : (gpuStateFlags & ~GPUSTATE_MAIN_BG1_MASK);
@@ -424,18 +476,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerMainBG1
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(1);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(GPULayerID_BG1);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
 
 - (void) setLayerMainBG2:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineMain()->SetLayerEnableState(2, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineMain()->SetLayerEnableState(GPULayerID_BG2, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_MAIN_BG2_MASK) : (gpuStateFlags & ~GPUSTATE_MAIN_BG2_MASK);
@@ -444,18 +496,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerMainBG2
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(2);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(GPULayerID_BG2);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
 
 - (void) setLayerMainBG3:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineMain()->SetLayerEnableState(3, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineMain()->SetLayerEnableState(GPULayerID_BG3, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_MAIN_BG3_MASK) : (gpuStateFlags & ~GPUSTATE_MAIN_BG3_MASK);
@@ -464,18 +516,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerMainBG3
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(3);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(GPULayerID_BG3);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
 
 - (void) setLayerMainOBJ:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineMain()->SetLayerEnableState(4, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineMain()->SetLayerEnableState(GPULayerID_OBJ, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_MAIN_OBJ_MASK) : (gpuStateFlags & ~GPUSTATE_MAIN_OBJ_MASK);
@@ -484,18 +536,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerMainOBJ
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(4);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineMain()->GetLayerEnableState(GPULayerID_OBJ);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
 
 - (void) setLayerSubGPU:(BOOL)gpuState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
 	GPU->GetEngineSub()->SetEnableState((gpuState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (gpuState) ? (gpuStateFlags | GPUSTATE_SUB_GPU_MASK) : (gpuStateFlags & ~GPUSTATE_SUB_GPU_MASK);
@@ -504,18 +556,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerSubGPU
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
 	const BOOL gpuState = GPU->GetEngineSub()->GetEnableState() ? YES : NO;
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferUnlock();
 	
 	return gpuState;
 }
 
 - (void) setLayerSubBG0:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineSub()->SetLayerEnableState(0, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineSub()->SetLayerEnableState(GPULayerID_BG0, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_SUB_BG0_MASK) : (gpuStateFlags & ~GPUSTATE_SUB_BG0_MASK);
@@ -524,18 +576,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerSubBG0
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(0);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(GPULayerID_BG0);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
 
 - (void) setLayerSubBG1:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineSub()->SetLayerEnableState(1, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineSub()->SetLayerEnableState(GPULayerID_BG1, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_SUB_BG1_MASK) : (gpuStateFlags & ~GPUSTATE_SUB_BG1_MASK);
@@ -544,18 +596,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerSubBG1
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(1);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(GPULayerID_BG1);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
 
 - (void) setLayerSubBG2:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineSub()->SetLayerEnableState(2, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineSub()->SetLayerEnableState(GPULayerID_BG2, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_SUB_BG2_MASK) : (gpuStateFlags & ~GPUSTATE_SUB_BG2_MASK);
@@ -564,18 +616,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerSubBG2
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(2);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(GPULayerID_BG2);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
 
 - (void) setLayerSubBG3:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineSub()->SetLayerEnableState(3, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineSub()->SetLayerEnableState(GPULayerID_BG3, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_SUB_BG3_MASK) : (gpuStateFlags & ~GPUSTATE_SUB_BG3_MASK);
@@ -584,18 +636,18 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerSubBG3
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(3);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(GPULayerID_BG3);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
 
 - (void) setLayerSubOBJ:(BOOL)layerState
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
-	GPU->GetEngineSub()->SetLayerEnableState(4, (layerState) ? true : false);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
+	GPU->GetEngineSub()->SetLayerEnableState(GPULayerID_OBJ, (layerState) ? true : false);
+	gpuEvent->FramebufferUnlock();
 	
 	OSSpinLockLock(&spinlockGpuState);
 	gpuStateFlags = (layerState) ? (gpuStateFlags | GPUSTATE_SUB_OBJ_MASK) : (gpuStateFlags & ~GPUSTATE_SUB_OBJ_MASK);
@@ -604,9 +656,9 @@ GPU3DInterface *core3DList[] = {
 
 - (BOOL) layerSubOBJ
 {
-	pthread_rwlock_rdlock(self.rwlockProducer);
-	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(4);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockRead();
+	const BOOL layerState = GPU->GetEngineSub()->GetLayerEnableState(GPULayerID_OBJ);
+	gpuEvent->FramebufferUnlock();
 	
 	return layerState;
 }
@@ -620,31 +672,120 @@ GPU3DInterface *core3DList[] = {
 {
 	NSString *theString = @"Uninitialized";
 	
-	pthread_rwlock_rdlock(self.rwlockProducer);
+	gpuEvent->Render3DLock();
 	
 	if(gpu3D == NULL)
 	{
-		pthread_rwlock_unlock(self.rwlockProducer);
+		gpuEvent->Render3DUnlock();
 		return theString;
 	}
 	
 	const char *theName = gpu3D->name;
 	theString = [NSString stringWithCString:theName encoding:NSUTF8StringEncoding];
 	
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->Render3DUnlock();
 	
 	return theString;
 }
 
 - (void) clearWithColor:(const uint16_t)colorBGRA5551
 {
-	pthread_rwlock_wrlock(self.rwlockProducer);
+	gpuEvent->FramebufferLockWrite();
 	GPU->ClearWithColor(colorBGRA5551);
-	pthread_rwlock_unlock(self.rwlockProducer);
+	gpuEvent->FramebufferUnlock();
 }
 
 @end
 
+GPUEventHandlerOSX::GPUEventHandlerOSX()
+{
+	_isRender3DLockHeld = false;
+	pthread_rwlock_init(&_rwlockFrame, NULL);
+	pthread_mutex_init(&_mutex3DRender, NULL);
+}
+
+GPUEventHandlerOSX::~GPUEventHandlerOSX()
+{
+	pthread_rwlock_destroy(&this->_rwlockFrame);
+	pthread_mutex_destroy(&this->_mutex3DRender);
+}
+
+void GPUEventHandlerOSX::DidFrameBegin()
+{
+	this->FramebufferLockWrite();
+}
+
+void GPUEventHandlerOSX::DidFrameEnd(bool isFrameSkipped)
+{
+	this->FramebufferUnlock();
+	
+	if (!isFrameSkipped)
+	{
+		for (CocoaDSOutput *cdsOutput in this->_cdsOutputList)
+		{
+			if ([cdsOutput isKindOfClass:[CocoaDSDisplay class]])
+			{
+				[cdsOutput doCoreEmuFrame];
+			}
+		}
+	}
+}
+
+void GPUEventHandlerOSX::DidRender3DBegin()
+{
+	this->_isRender3DLockHeld = true;
+	this->Render3DLock();
+}
+
+void GPUEventHandlerOSX::DidRender3DEnd()
+{
+	if (this->_isRender3DLockHeld)
+	{
+		this->Render3DUnlock();
+		this->_isRender3DLockHeld = false;
+	}
+}
+
+void GPUEventHandlerOSX::FramebufferLockWrite()
+{
+	pthread_rwlock_wrlock(&this->_rwlockFrame);
+}
+
+void GPUEventHandlerOSX::FramebufferLockRead()
+{
+	pthread_rwlock_rdlock(&this->_rwlockFrame);
+}
+
+void GPUEventHandlerOSX::FramebufferUnlock()
+{
+	pthread_rwlock_unlock(&this->_rwlockFrame);
+}
+
+void GPUEventHandlerOSX::Render3DLock()
+{
+	pthread_mutex_lock(&this->_mutex3DRender);
+}
+
+void GPUEventHandlerOSX::Render3DUnlock()
+{
+	pthread_mutex_unlock(&this->_mutex3DRender);
+}
+
+pthread_rwlock_t* GPUEventHandlerOSX::GetFrameRWLock()
+{
+	return &this->_rwlockFrame;
+}
+
+NSMutableArray* GPUEventHandlerOSX::GetOutputList()
+{
+	return this->_cdsOutputList;
+}
+
+void GPUEventHandlerOSX::SetOutputList(NSMutableArray *outputList)
+{
+	this->_cdsOutputList = outputList;
+}
+
 CGLContextObj OSXOpenGLRendererContext = NULL;
 CGLPBufferObj OSXOpenGLRendererPBuffer = NULL;
 
diff --git a/desmume/src/cocoa/cocoa_core.mm b/desmume/src/cocoa/cocoa_core.mm
index bf402eb88..a8848f093 100644
--- a/desmume/src/cocoa/cocoa_core.mm
+++ b/desmume/src/cocoa/cocoa_core.mm
@@ -213,7 +213,7 @@ volatile bool execute = true;
 	sp.sched_priority = sched_get_priority_max(thePolicy);
 	pthread_setschedparam(coreThread, thePolicy, &sp);
 	
-	[cdsGPU setRwlockProducer:self.rwlockCoreExecute];
+	[cdsGPU setOutputList:cdsOutputList];
 	
 	OSXDriver *newDriver = new OSXDriver;
 	newDriver->SetCoreThreadMutexLock(&threadParam.mutexThreadExecute);
@@ -950,7 +950,16 @@ volatile bool execute = true;
 - (void) addOutput:(CocoaDSOutput *)theOutput
 {
 	pthread_mutex_lock(&threadParam.mutexOutputList);
-	[theOutput setRwlockProducer:[self rwlockCoreExecute]];
+	
+	if ([theOutput isKindOfClass:[CocoaDSDisplay class]])
+	{
+		[theOutput setRwlockProducer:[[self cdsGPU] gpuFrameRWLock]];
+	}
+	else
+	{
+		[theOutput setRwlockProducer:[self rwlockCoreExecute]];
+	}
+	
 	[[self cdsOutputList] addObject:theOutput];
 	pthread_mutex_unlock(&threadParam.mutexOutputList);
 }
@@ -1145,12 +1154,10 @@ static void* RunCoreThread(void *arg)
 			{
 				for(CocoaDSOutput *cdsOutput in cdsOutputList)
 				{
-					if (param->framesToSkip > 0 && [cdsOutput isKindOfClass:[CocoaDSDisplay class]])
+					if (![cdsOutput isKindOfClass:[CocoaDSDisplay class]])
 					{
-						continue;
+						[cdsOutput doCoreEmuFrame];
 					}
-					
-					[cdsOutput doCoreEmuFrame];
 				}
 				break;
 			}
@@ -1159,7 +1166,10 @@ static void* RunCoreThread(void *arg)
 			{
 				for(CocoaDSOutput *cdsOutput in cdsOutputList)
 				{
-					[cdsOutput doCoreEmuFrame];
+					if (![cdsOutput isKindOfClass:[CocoaDSDisplay class]])
+					{
+						[cdsOutput doCoreEmuFrame];
+					}
 				}
 				break;
 			}
@@ -1168,7 +1178,7 @@ static void* RunCoreThread(void *arg)
 			{
 				for(CocoaDSOutput *cdsOutput in cdsOutputList)
 				{
-					if ([cdsOutput isKindOfClass:[CocoaDSDisplay class]] && (param->framesToSkip == 0 || frameNum >= param->frameJumpTarget))
+					if (![cdsOutput isKindOfClass:[CocoaDSDisplay class]])
 					{
 						[cdsOutput doCoreEmuFrame];
 					}
diff --git a/desmume/src/gfx3d.cpp b/desmume/src/gfx3d.cpp
index efcaa7469..749a68daa 100644
--- a/desmume/src/gfx3d.cpp
+++ b/desmume/src/gfx3d.cpp
@@ -559,7 +559,6 @@ void gfx3d_init()
 	
 	makeTables();
 	Render3D_Init();
-	gfx3d_reset();
 }
 
 void gfx3d_deinit()
diff --git a/desmume/src/rasterize.cpp b/desmume/src/rasterize.cpp
index 175b276b3..e721a93ea 100644
--- a/desmume/src/rasterize.cpp
+++ b/desmume/src/rasterize.cpp
@@ -1933,6 +1933,7 @@ Render3DError SoftRasterizerRenderer::Render(const GFX3D &engine)
 {
 	Render3DError error = RENDER3DERROR_NOERR;
 	
+	GPU->GetEventHandler()->DidRender3DBegin();
 	error = this->BeginRender(engine);
 	if (error != RENDER3DERROR_NOERR)
 	{
@@ -1970,6 +1971,7 @@ Render3DError SoftRasterizerRenderer::RenderFinish()
 {
 	if (!this->_renderGeometryNeedsFinish)
 	{
+		GPU->GetEventHandler()->DidRender3DEnd();
 		return RENDER3DERROR_NOERR;
 	}
 	
@@ -2005,6 +2007,7 @@ Render3DError SoftRasterizerRenderer::RenderFinish()
 	
 	this->FlushFramebuffer(GPU->GetEngineMain()->Get3DFramebufferRGBA6665(), GPU->GetEngineMain()->Get3DFramebufferRGBA5551());
 	
+	GPU->GetEventHandler()->DidRender3DEnd();
 	return RENDER3DERROR_NOERR;
 }
 
diff --git a/desmume/src/render3D.cpp b/desmume/src/render3D.cpp
index f184f6568..2805c97f4 100644
--- a/desmume/src/render3D.cpp
+++ b/desmume/src/render3D.cpp
@@ -437,6 +437,7 @@ Render3DError Render3D::Render(const GFX3D &engine)
 {
 	Render3DError error = RENDER3DERROR_NOERR;
 	
+	GPU->GetEventHandler()->DidRender3DBegin();
 	error = this->BeginRender(engine);
 	if (error != RENDER3DERROR_NOERR)
 	{
@@ -465,6 +466,7 @@ Render3DError Render3D::Render(const GFX3D &engine)
 
 Render3DError Render3D::RenderFinish()
 {
+	GPU->GetEventHandler()->DidRender3DEnd();
 	return RENDER3DERROR_NOERR;
 }