void* FD3D12DynamicRHI::LockBuffer(FRHICommandListImmediate* RHICmdList, BufferType* Buffer, uint32 Offset, uint32 Size, EResourceLockMode LockMode)
{

#if STATS
	LockBufferCalls++;
	SCOPE_CYCLE_COUNTER(STAT_D3D12LockBufferTime);
	INC_DWORD_STAT_BY(STAT_D3D12LockBufferCalls, LockBufferCalls);
#endif

	FD3D12LockedResource& LockedData = Buffer->LockedData;
	check(LockedData.bLocked == false);
	FD3D12Device* Device = GetRHIDevice();
	FD3D12Adapter& Adapter = GetAdapter();

	// Determine whether the buffer is dynamic or not.
	const bool bIsDynamic = (Buffer->GetUsage() & BUF_AnyDynamic) ? true : false;

	void* Data = nullptr;

	if (bIsDynamic)
	{
		check(LockMode == RLM_WriteOnly);

		BufferType* CurrentBuffer = Buffer;

		// Update all of the resources in the LDA chain
		while (CurrentBuffer)
		{
			// Allocate a new resource

			// If on the RenderThread, queue up a command on the RHIThread to rename this buffer at the correct time
			if (ShouldDeferBufferLockOperation(RHICmdList))
			{
				FRHICommandRenameUploadBuffer<BufferType>* Command = new (RHICmdList->AllocCommand<FRHICommandRenameUploadBuffer<BufferType>>()) FRHICommandRenameUploadBuffer<BufferType>(CurrentBuffer, Device);

				Data = Adapter.GetUploadHeapAllocator().AllocUploadResource(Buffer->GetSize(), Buffer->BufferAlignment, Command->NewResource);
			}
			else
			{
				FD3D12ResourceLocation Location(CurrentBuffer->GetParentDevice());
				Data = Adapter.GetUploadHeapAllocator().AllocUploadResource(Buffer->GetSize(), Buffer->BufferAlignment, Location);
				CurrentBuffer->Rename(Location);
			}

			CurrentBuffer = CurrentBuffer->GetNextObject();
		}
	}
	else
	{
		FD3D12Resource* pResource = Buffer->ResourceLocation.GetResource();

		// Locking for read must occur immediately so we can't queue up the operations later.
		if (LockMode == RLM_ReadOnly)
		{
			LockedData.bLockedForReadOnly = true;
			// If the static buffer is being locked for reading, create a staging buffer.
			FD3D12Resource* StagingBuffer = nullptr;

			const GPUNodeMask Node = Device->GetNodeMask();
			VERIFYD3D12RESULT(Adapter.CreateBuffer(D3D12_HEAP_TYPE_READBACK, Node, Node, Offset + Size, &StagingBuffer));

			// Copy the contents of the buffer to the staging buffer.
			{
				const auto& pfnCopyContents = [&]()
				{
					FD3D12CommandContext& DefaultContext = Device->GetDefaultCommandContext();

					FD3D12CommandListHandle& hCommandList = DefaultContext.CommandListHandle;
					FScopeResourceBarrier ScopeResourceBarrierSource(hCommandList, pResource, pResource->GetDefaultResourceState(), D3D12_RESOURCE_STATE_COPY_SOURCE, 0);
					// Don't need to transition upload heaps

					DefaultContext.numCopies++;
					hCommandList->CopyBufferRegion(
						StagingBuffer->GetResource(),
						0,
						pResource->GetResource(),
						Offset, Size);

					hCommandList.UpdateResidency(StagingBuffer);
					hCommandList.UpdateResidency(pResource);

					DefaultContext.FlushCommands(true);
				};

				if (ShouldDeferBufferLockOperation(RHICmdList))
				{
					// Sync when in the render thread implementation
					check(IsInRHIThread() == false);

					RHICmdList->ImmediateFlush(EImmediateFlushType::FlushRHIThread);
					pfnCopyContents();
				}
				else
				{
					check(IsInRHIThread());
					pfnCopyContents();
				}
			}

			LockedData.ResourceLocation.AsStandAlone(StagingBuffer, Size);
			Data = LockedData.ResourceLocation.GetMappedBaseAddress();
		}
		else
		{
			// If the static buffer is being locked for writing, allocate memory for the contents to be written to.
			Data = Device->GetDefaultFastAllocator().Allocate<FD3D12ScopeLock>(Size, D3D12_TEXTURE_DATA_PLACEMENT_ALIGNMENT, &LockedData.ResourceLocation);
		}
	}

	LockedData.LockedOffset = Offset;
	LockedData.LockedPitch = Size;
	LockedData.bLocked = true;

	// Return the offset pointer
	check(Data != nullptr);
	return Data;
}
void* FD3D12DynamicRHI::LockBuffer(FRHICommandListImmediate* RHICmdList, BufferType* Buffer, uint32 Offset, uint32 Size, EResourceLockMode LockMode)
{
	FD3D12LockedData LockedData;

	// Determine whether the buffer is dynamic or not.
	const bool bIsDynamic = (Buffer->GetUsage() & BUF_AnyDynamic) ? true : false;

	void* Data = nullptr;

	if (bIsDynamic)
	{
		check(LockMode == RLM_WriteOnly);

		TRefCountPtr<FD3D12ResourceLocation> newLocation = new FD3D12ResourceLocation(GetRHIDevice());

		// Allocate a new resource
		Data = GetRHIDevice()->GetDefaultUploadHeapAllocator().AllocUploadResource(Buffer->ResourceLocation->GetEffectiveBufferSize(), Buffer->BufferAlignment, newLocation);

		// If on the RenderThread, queue up a command on the RHIThread to rename this buffer at the correct time
		if (ShouldDeferBufferLockOperation(RHICmdList))
		{
			new (RHICmdList->AllocCommand<FRHICommandRenameUploadBuffer<BufferType>>()) FRHICommandRenameUploadBuffer<BufferType>(Buffer, newLocation);
		}
		else
		{
			Buffer->Rename(newLocation);
		}
	}
	else
	{
		FD3D12Resource* pResource = Buffer->ResourceLocation->GetResource();

		// Locking for read must occur immediately so we can't queue up the operations later.
		if (LockMode == RLM_ReadOnly)
		{
			// If the static buffer is being locked for reading, create a staging buffer.
			TRefCountPtr<FD3D12Resource> StagingBuffer;
			VERIFYD3D11RESULT(GetRHIDevice()->GetResourceHelper().CreateBuffer(D3D12_HEAP_TYPE_READBACK, Offset + Size, StagingBuffer.GetInitReference()));
			LockedData.StagingResource = StagingBuffer;

			// Copy the contents of the buffer to the staging buffer.
			{
				const auto& pfnCopyContents = [&]()
				{
					FD3D12CommandContext& DefaultContext = GetRHIDevice()->GetDefaultCommandContext();

					FD3D12CommandListHandle& hCommandList = DefaultContext.CommandListHandle;
					FScopeResourceBarrier ScopeResourceBarrierSource(hCommandList, pResource, pResource->GetDefaultResourceState(), D3D12_RESOURCE_STATE_COPY_SOURCE, 0);
					// Don't need to transition upload heaps

					DefaultContext.numCopies++;
					hCommandList->CopyBufferRegion(
						StagingBuffer->GetResource(),
						0,
						pResource->GetResource(),
						Offset, Size);

					DefaultContext.FlushCommands(true);
				};

				if (ShouldDeferBufferLockOperation(RHICmdList))
				{
					// Sync when in the render thread implementation
					check(IsInRHIThread() == false);

					RHICmdList->ImmediateFlush(EImmediateFlushType::FlushRHIThread);
					pfnCopyContents();
				}
				else
				{
					check(IsInRHIThread());
					pfnCopyContents();
				}
			}

			// Map the staging buffer's memory for reading.
			VERIFYD3D11RESULT(StagingBuffer->GetResource()->Map(0, nullptr, &Data));
		}
		else
		{
			// If the static buffer is being locked for writing, allocate memory for the contents to be written to.
			TRefCountPtr<FD3D12ResourceLocation> UploadBufferLocation = new FD3D12ResourceLocation(GetRHIDevice());
			Data = GetRHIDevice()->GetDefaultFastAllocator().Allocate(Offset + Size, D3D12_TEXTURE_DATA_PLACEMENT_ALIGNMENT, UploadBufferLocation);

			// Keep track of the underlying resource for the upload heap so it can be referenced during Unmap.
			LockedData.UploadHeapLocation = UploadBufferLocation;
		}
	}

	check(Data);
	// Add the lock to the lock map.
	LockedData.SetData(Data);
	LockedData.Pitch = Offset + Size;

	// Add the lock to the lock map.
	FD3D12LockedKey LockedKey(Buffer);
	AddToOutstandingLocks(LockedKey, LockedData);

	// Return the offset pointer
	return (void*)((uint8*)LockedData.GetData() + Offset);
}
BufferType* FD3D12Adapter::CreateRHIBuffer(FRHICommandListImmediate* RHICmdList,
	const D3D12_RESOURCE_DESC& InDesc,
	uint32 Alignment,
	uint32 Stride,
	uint32 Size,
	uint32 InUsage,
	FRHIResourceCreateInfo& CreateInfo,
	bool SkipCreate)
{
	const bool bIsDynamic = (InUsage & BUF_AnyDynamic) ? true : false;

	BufferType* BufferOut = CreateLinkedObject<BufferType>([&](FD3D12Device* Device)
	{
		BufferType* NewBuffer = new BufferType(Device, Stride, Size, InUsage);
		NewBuffer->BufferAlignment = Alignment;

		if (SkipCreate == false)
		{
			AllocateBuffer(Device, InDesc, Size, InUsage, CreateInfo, Alignment, NewBuffer->ResourceLocation);
		}

		return NewBuffer;
	});

	if (CreateInfo.ResourceArray)
	{
		if (bIsDynamic == false && BufferOut->ResourceLocation.IsValid())
		{
			check(Size == CreateInfo.ResourceArray->GetResourceDataSize());

			// Get an upload heap and initialize data
			FD3D12ResourceLocation SrcResourceLoc(BufferOut->GetParentDevice());
			void* pData = SrcResourceLoc.GetParentDevice()->GetDefaultFastAllocator().Allocate<FD3D12ScopeLock>(Size, 4UL, &SrcResourceLoc);
			check(pData);
			FMemory::Memcpy(pData, CreateInfo.ResourceArray->GetResourceData(), Size);

			const auto& pfnUpdateBuffer = [&]()
			{
				BufferType* CurrentBuffer = BufferOut;
				while (CurrentBuffer != nullptr)
				{
					FD3D12Resource* Destination = CurrentBuffer->ResourceLocation.GetResource();
					FD3D12Device* Device = Destination->GetParentDevice();

					FD3D12CommandListHandle& hCommandList = Device->GetDefaultCommandContext().CommandListHandle;
					// Copy from the temporary upload heap to the default resource
					{
						// Writable structured bufferes are sometimes initialized with inital data which means they sometimes need tracking.
						FConditionalScopeResourceBarrier ConditionalScopeResourceBarrier(hCommandList, Destination, D3D12_RESOURCE_STATE_COPY_DEST, 0);

						Device->GetDefaultCommandContext().numCopies++;
						hCommandList->CopyBufferRegion(
							Destination->GetResource(),
							CurrentBuffer->ResourceLocation.GetOffsetFromBaseOfResource(),
							SrcResourceLoc.GetResource()->GetResource(),
							SrcResourceLoc.GetOffsetFromBaseOfResource(), Size);

						hCommandList.UpdateResidency(Destination);
					}

					CurrentBuffer = CurrentBuffer->GetNextObject();
				}
			};

			//TODO: This should be a deferred op like the buffer lock/unlocks
			// We only need to synchronize when creating default resource buffers (because we need a command list to initialize them)
			if (RHICmdList)
			{
				FScopedRHIThreadStaller StallRHIThread(*RHICmdList);
				pfnUpdateBuffer();
			}
			else
			{
				pfnUpdateBuffer();
			}
		}

		// Discard the resource array's contents.
		CreateInfo.ResourceArray->Discard();
	}

	return BufferOut;
}