BansheeEngine/Source/BansheeVulkanRenderAPI/Source/BsVulkanHardwareBuffer.cpp

//********************************** Banshee Engine (www.banshee3d.com) **************************************************//
//**************** Copyright (c) 2016 Marko Pintera ([email protected]). All rights reserved. **********************//
#include "BsVulkanHardwareBuffer.h"
#include "BsVulkanRenderAPI.h"
#include "BsVulkanDevice.h"
#include "BsVulkanUtility.h"
#include "BsVulkanCommandBufferManager.h"
#include "BsVulkanCommandBuffer.h"
#include "BsVulkanTexture.h"

namespace bs { namespace ct
{
	VulkanBuffer::VulkanBuffer(VulkanResourceManager* owner, VkBuffer buffer, VkBufferView view, VkDeviceMemory memory,
							   UINT32 rowPitch, UINT32 slicePitch)
		: VulkanResource(owner, false), mBuffer(buffer), mView(view), mMemory(memory), mRowPitch(rowPitch)
	{
		if (rowPitch != 0)
			mSliceHeight = slicePitch / rowPitch;
		else
			mSliceHeight = 0;
	}

	VulkanBuffer::~VulkanBuffer()
	{
		VulkanDevice& device = mOwner->getDevice();

		if (mView != VK_NULL_HANDLE)
			vkDestroyBufferView(device.getLogical(), mView, gVulkanAllocator);

		vkDestroyBuffer(device.getLogical(), mBuffer, gVulkanAllocator);
		device.freeMemory(mMemory);
	}

	UINT8* VulkanBuffer::map(VkDeviceSize offset, VkDeviceSize length) const
	{
		VulkanDevice& device = mOwner->getDevice();

		UINT8* data;
		VkResult result = vkMapMemory(device.getLogical(), mMemory, offset, length, 0, (void**)&data);
		assert(result == VK_SUCCESS);

		return data;
	}

	void VulkanBuffer::unmap()
	{
		VulkanDevice& device = mOwner->getDevice();

		vkUnmapMemory(device.getLogical(), mMemory);
	}

	void VulkanBuffer::copy(VulkanTransferBuffer* cb, VulkanBuffer* destination, VkDeviceSize srcOffset, 
		VkDeviceSize dstOffset, VkDeviceSize length)
	{
		VkBufferCopy region;
		region.size = length;
		region.srcOffset = srcOffset;
		region.dstOffset = dstOffset;

		vkCmdCopyBuffer(cb->getCB()->getHandle(), mBuffer, destination->getHandle(), 1, &region);
	}

	void VulkanBuffer::copy(VulkanTransferBuffer* cb, VulkanImage* destination, const VkExtent3D& extent, 
		const VkImageSubresourceLayers& range, VkImageLayout layout)
	{
		VkBufferImageCopy region;
		region.bufferRowLength = mRowPitch;
		region.bufferImageHeight = mSliceHeight;
		region.bufferOffset = 0;
		region.imageOffset.x = 0;
		region.imageOffset.y = 0;
		region.imageOffset.z = 0;
		region.imageExtent = extent;
		region.imageSubresource = range;

		vkCmdCopyBufferToImage(cb->getCB()->getHandle(), mBuffer, destination->getHandle(), layout, 1, &region);
	}

	void VulkanBuffer::update(VulkanTransferBuffer* cb, UINT8* data, VkDeviceSize offset, VkDeviceSize length)
	{
		vkCmdUpdateBuffer(cb->getCB()->getHandle(), mBuffer, offset, length, (uint32_t*)data);
	}

	VulkanHardwareBuffer::VulkanHardwareBuffer(BufferType type, GpuBufferFormat format, GpuBufferUsage usage, 
		UINT32 size, GpuDeviceFlags deviceMask)
		: HardwareBuffer(size), mBuffers(), mStagingBuffer(nullptr), mStagingMemory(nullptr), mMappedDeviceIdx(-1)
		, mMappedGlobalQueueIdx(-1), mMappedOffset(0), mMappedSize(0), mMappedLockOptions(GBL_WRITE_ONLY)
		, mDirectlyMappable((usage & GBU_DYNAMIC) != 0), mSupportsGPUWrites(type == BT_STORAGE), mRequiresView(false)
		, mIsMapped(false)
	{
		VkBufferUsageFlags usageFlags = 0;
		switch(type)
		{
		case BT_VERTEX:
			usageFlags = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
			break;
		case BT_INDEX:
			usageFlags = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_INDEX_BUFFER_BIT;
			break;
		case BT_UNIFORM:
			usageFlags = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT;
			break;
		case BT_GENERIC:
			usageFlags = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_UNIFORM_TEXEL_BUFFER_BIT;
			mRequiresView = true;
			break;
		case BT_STORAGE:
			usageFlags = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_STORAGE_TEXEL_BUFFER_BIT;
			mRequiresView = true;
			break;
		case BT_STRUCTURED:
			usageFlags = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_STORAGE_BUFFER_BIT;
			break;
		}

		mBufferCI.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
		mBufferCI.pNext = nullptr;
		mBufferCI.flags = 0;
		mBufferCI.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
		mBufferCI.usage = usageFlags;
		mBufferCI.queueFamilyIndexCount = 0;
		mBufferCI.pQueueFamilyIndices = nullptr;

		mViewCI.sType = VK_STRUCTURE_TYPE_BUFFER_VIEW_CREATE_INFO;
		mViewCI.pNext = nullptr;
		mViewCI.flags = 0;
		mViewCI.format = VulkanUtility::getBufferFormat(format);
		mViewCI.offset = 0;
		mViewCI.range = VK_WHOLE_SIZE;

		VulkanRenderAPI& rapi = static_cast<VulkanRenderAPI&>(RenderAPI::instance());
		VulkanDevice* devices[BS_MAX_DEVICES];
		VulkanUtility::getDevices(rapi, deviceMask, devices);

		// Allocate buffers per-device
		for (UINT32 i = 0; i < BS_MAX_DEVICES; i++)
		{
			if (devices[i] == nullptr)
				continue;

			mBuffers[i] = createBuffer(*devices[i], size, false, true);
		}
	}

	VulkanHardwareBuffer::~VulkanHardwareBuffer()
	{
		for (UINT32 i = 0; i < BS_MAX_DEVICES; i++)
		{
			if (mBuffers[i] == nullptr)
				continue;

			mBuffers[i]->destroy();
		}

		assert(mStagingBuffer == nullptr);
	}

	VulkanBuffer* VulkanHardwareBuffer::createBuffer(VulkanDevice& device, UINT32 size, bool staging, bool readable)
	{
		VkBufferUsageFlags usage = mBufferCI.usage;
		if (staging)
		{
			mBufferCI.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;

			// Staging buffers are used as a destination for reads
			if (readable)
				mBufferCI.usage |= VK_BUFFER_USAGE_TRANSFER_DST_BIT;
		}
		else if(readable) // Non-staging readable
			mBufferCI.usage |= VK_BUFFER_USAGE_TRANSFER_SRC_BIT;

		mBufferCI.size = size;

		VkMemoryPropertyFlags flags = (mDirectlyMappable || staging) ?
			(VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT) : // Note: Try using cached memory
			VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;

		VkDevice vkDevice = device.getLogical();

		VkBuffer buffer;
		VkResult result = vkCreateBuffer(vkDevice, &mBufferCI, gVulkanAllocator, &buffer);
		assert(result == VK_SUCCESS);

		VkMemoryRequirements memReqs;
		vkGetBufferMemoryRequirements(vkDevice, buffer, &memReqs);

		VkDeviceMemory memory = device.allocateMemory(memReqs, flags);
		result = vkBindBufferMemory(vkDevice, buffer, memory, 0);
		assert(result == VK_SUCCESS);

		VkBufferView view;
		if (mRequiresView && !staging)
		{
			mViewCI.buffer = buffer;

			result = vkCreateBufferView(vkDevice, &mViewCI, gVulkanAllocator, &view);
			assert(result == VK_SUCCESS);
		}
		else
			view = VK_NULL_HANDLE;

		mBufferCI.usage = usage; // Restore original usage
		return device.getResourceManager().create<VulkanBuffer>(buffer, view, memory);
	}

	void* VulkanHardwareBuffer::map(UINT32 offset, UINT32 length, GpuLockOptions options, UINT32 deviceIdx, UINT32 queueIdx)
	{
		if ((offset + length) > mSize)
		{
			LOGERR("Provided offset(" + toString(offset) + ") + length(" + toString(length) + ") "
				   "is larger than the buffer " + toString(mSize) + ".");

			return nullptr;
		}

		if (length == 0)
			return nullptr;

		VulkanBuffer* buffer = mBuffers[deviceIdx];

		if (buffer == nullptr)
			return nullptr;

		mIsMapped = true;
		mMappedDeviceIdx = deviceIdx;
		mMappedGlobalQueueIdx = queueIdx;
		mMappedOffset = offset;
		mMappedSize = length;
		mMappedLockOptions = options;

		VulkanRenderAPI& rapi = static_cast<VulkanRenderAPI&>(RenderAPI::instance());
		VulkanDevice& device = *rapi._getDevice(deviceIdx);

		VulkanCommandBufferManager& cbManager = gVulkanCBManager();
		GpuQueueType queueType;
		UINT32 localQueueIdx = CommandSyncMask::getQueueIdxAndType(queueIdx, queueType);

		VkAccessFlags accessFlags;
		if (options == GBL_READ_ONLY)
			accessFlags = VK_ACCESS_HOST_READ_BIT;
		else if (options == GBL_READ_WRITE)
			accessFlags = VK_ACCESS_HOST_READ_BIT | VK_ACCESS_HOST_WRITE_BIT;
		else
			accessFlags = VK_ACCESS_HOST_WRITE_BIT;

		// If memory is host visible try mapping it directly
		if(mDirectlyMappable)
		{
			// Check is the GPU currently reading or writing from the buffer
			UINT32 useMask = buffer->getUseInfo(VulkanUseFlag::Read | VulkanUseFlag::Write);

			// Note: Even if GPU isn't currently using the buffer, but the buffer supports GPU writes, we consider it as
			// being used because the write could have completed yet still not visible, so we need to issue a pipeline
			// barrier below.
			bool isUsedOnGPU = useMask != 0 || mSupportsGPUWrites;

			// We're safe to map directly since GPU isn't using the buffer
			if (!isUsedOnGPU)
			{
				// If some CB has an operation queued that will be using the current contents of the buffer, create a new 
				// buffer so we don't modify the previous use of the buffer
				if(buffer->isBound())
				{
					VulkanBuffer* newBuffer = createBuffer(device, mSize, false, true);

					// Copy contents of the current buffer to the new one, unless caller explicitly specifies he doesn't
					// care about the current contents
					if (options != GBL_WRITE_ONLY_DISCARD)
					{
						UINT8* src = buffer->map(offset, length);
						UINT8* dst = newBuffer->map(offset, length);

						memcpy(dst, src, length);

						buffer->unmap();
						newBuffer->unmap();
					}

					buffer->destroy();
					buffer = newBuffer;
					mBuffers[deviceIdx] = buffer;
				}

				return buffer->map(offset, length);
			}

			// Caller guarantees he won't touch the same data as the GPU, so just map even though the GPU is using the buffer
			if (options == GBL_WRITE_ONLY_NO_OVERWRITE)
				return buffer->map(offset, length);

			// Caller doesn't care about buffer contents, so just discard the existing buffer and create a new one
			if (options == GBL_WRITE_ONLY_DISCARD)
			{
				buffer->destroy();

				buffer = createBuffer(device, mSize, false, true);
				mBuffers[deviceIdx] = buffer;

				return buffer->map(offset, length);
			}

			// We need to read the buffer contents
			if(options == GBL_READ_ONLY || options == GBL_READ_WRITE)
			{
				// We need to wait until (potential) read/write operations complete
				VulkanTransferBuffer* transferCB = cbManager.getTransferBuffer(deviceIdx, queueType, localQueueIdx);

				// Ensure flush() will wait for all queues currently using to the buffer (if any) to finish
				// If only reading, wait for all writes to complete, otherwise wait on both writes and reads
				if (options == GBL_READ_ONLY)
					useMask = buffer->getUseInfo(VulkanUseFlag::Write);
				else
					useMask = buffer->getUseInfo(VulkanUseFlag::Read | VulkanUseFlag::Write);

				transferCB->appendMask(useMask);

				// Make any writes visible before mapping
				if (mSupportsGPUWrites)
				{
					// Issue a barrier so :
					//  - If reading: the device makes the written memory available for read (read-after-write hazard)
					//  - If writing: ensures our writes properly overlap with GPU writes (write-after-write hazard)
					transferCB->memoryBarrier(buffer->getHandle(),
											  VK_ACCESS_SHADER_WRITE_BIT,
											  accessFlags,
											  // Last stages that could have written to the buffer:
											  VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT | VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT,
											  VK_PIPELINE_STAGE_HOST_BIT
					);
				}

				// Submit the command buffer and wait until it finishes
				transferCB->flush(true);

				// If writing and some CB has an operation queued that will be using the current contents of the buffer, 
				// create a new  buffer so we don't modify the previous use of the buffer
				if (options == GBL_READ_WRITE && buffer->isBound())
				{
					VulkanBuffer* newBuffer = createBuffer(device, mSize, false, true);

					// Copy contents of the current buffer to the new one
					UINT8* src = buffer->map(offset, length);
					UINT8* dst = newBuffer->map(offset, length);

					memcpy(dst, src, length);

					buffer->unmap();
					newBuffer->unmap();

					buffer->destroy();
					buffer = newBuffer;
					mBuffers[deviceIdx] = buffer;
				}

				return buffer->map(offset, length);
			}

			// Otherwise, we're doing write only, in which case it's best to use the staging buffer to avoid waiting
			// and blocking, so fall through
		}

		// Can't use direct mapping, so use a staging buffer or memory

		// We might need to copy the current contents of the buffer to the staging buffer. Even if the user doesn't plan on
		// reading, it is still required as we will eventually copy all of the contents back to the original buffer,
		// and we can't write potentially uninitialized data. The only exception is when the caller specifies the buffer
		// contents should be discarded in which he guarantees he will overwrite the entire locked area with his own
		// contents.
		bool needRead = options != GBL_WRITE_ONLY_DISCARD_RANGE && options != GBL_WRITE_ONLY_DISCARD;
		
		// See if we can use the cheaper staging memory, rather than a staging buffer
		if(!needRead && offset % 4 == 0 && length % 4 == 0 && length <= 65536)
		{
			mStagingMemory = (UINT8*)bs_alloc(length);
			return mStagingMemory;
		}

		// Create a staging buffer
		mStagingBuffer = createBuffer(device, length, true, needRead);

		if (needRead)
		{
			VulkanTransferBuffer* transferCB = cbManager.getTransferBuffer(deviceIdx, queueType, localQueueIdx);
				
			// Similar to above, if buffer supports GPU writes or is currently being written to, we need to wait on any
			// potential writes to complete
			UINT32 writeUseMask = buffer->getUseInfo(VulkanUseFlag::Write);
			if(mSupportsGPUWrites || writeUseMask != 0)
			{
				// Ensure flush() will wait for all queues currently writing to the buffer (if any) to finish
				transferCB->appendMask(writeUseMask);
			}

			// Queue copy command
			buffer->copy(transferCB, mStagingBuffer, offset, 0, length);

			// Ensure data written to the staging buffer is visible
			transferCB->memoryBarrier(mStagingBuffer->getHandle(),
										VK_ACCESS_TRANSFER_WRITE_BIT,
										accessFlags,
										VK_PIPELINE_STAGE_TRANSFER_BIT,
										VK_PIPELINE_STAGE_HOST_BIT
			);

			// Submit the command buffer and wait until it finishes
			transferCB->flush(true);
			assert(!buffer->isUsed());
		}

		return mStagingBuffer->map(0, length);
	}

	void VulkanHardwareBuffer::unmap()
	{
		// Possibly map() failed with some error
		if (!mIsMapped)
			return;

		// Note: If we did any writes they need to be made visible to the GPU. However there is no need to execute 
		// a pipeline barrier because (as per spec) host writes are implicitly visible to the device.

		if(mStagingMemory == nullptr && mStagingBuffer == nullptr) // We directly mapped the buffer
		{
			mBuffers[mMappedDeviceIdx]->unmap();
		} 
		else
		{
			if(mStagingBuffer != nullptr)
				mStagingBuffer->unmap();

			bool isWrite = mMappedLockOptions != GBL_READ_ONLY;

			// We the caller wrote anything to the staging buffer, we need to upload it back to the main buffer
			if(isWrite)
			{
				VulkanRenderAPI& rapi = static_cast<VulkanRenderAPI&>(RenderAPI::instance());
				VulkanDevice& device = *rapi._getDevice(mMappedDeviceIdx);

				VulkanCommandBufferManager& cbManager = gVulkanCBManager();
				GpuQueueType queueType;
				UINT32 localQueueIdx = CommandSyncMask::getQueueIdxAndType(mMappedGlobalQueueIdx, queueType);

				VulkanBuffer* buffer = mBuffers[mMappedDeviceIdx];
				VulkanTransferBuffer* transferCB = cbManager.getTransferBuffer(mMappedDeviceIdx, queueType, localQueueIdx);

				// If the buffer is used in any way on the GPU, we need to wait for that use to finish before
				// we issue our copy
				UINT32 useMask = buffer->getUseInfo(VulkanUseFlag::Read | VulkanUseFlag::Write);
				bool isNormalWrite = false;
				if(useMask != 0) // Buffer is currently used on the GPU
				{
					// Try to avoid the wait by checking for special write conditions

					// Caller guarantees he won't touch the same data as the GPU, so just copy
					if (mMappedLockOptions == GBL_WRITE_ONLY_NO_OVERWRITE) 
					{
						// Fall through to copy()
					}
					// Caller doesn't care about buffer contents, so just discard the existing buffer and create a new one
					else if (mMappedLockOptions == GBL_WRITE_ONLY_DISCARD)
					{
						buffer->destroy();

						buffer = createBuffer(device, mSize, false, true);
						mBuffers[mMappedDeviceIdx] = buffer;
					} 
					else // Otherwise we have no choice but to issue a dependency between the queues
					{
						transferCB->appendMask(useMask);
						isNormalWrite = true;
					}
				}
				else
					isNormalWrite = true;

				// Check if the buffer will still be bound somewhere after the CBs using it finish
				if (isNormalWrite)
				{
					UINT32 useCount = buffer->getUseCount();
					UINT32 boundCount = buffer->getBoundCount();

					bool isBoundWithoutUse = boundCount > useCount;

					// If buffer is queued for some operation on a CB, then we need to make a copy of the buffer to
					// avoid modifying its use in the previous operation
					if (isBoundWithoutUse)
					{
						VulkanBuffer* newBuffer = createBuffer(device, mSize, false, true);

						// Avoid copying original contents if the staging buffer completely covers it
						if (mMappedOffset > 0 || mMappedSize != mSize)
						{
							buffer->copy(transferCB, newBuffer, 0, 0, mSize);

							transferCB->getCB()->registerResource(buffer, VK_ACCESS_TRANSFER_READ_BIT, VulkanUseFlag::Read);
						}

						buffer->destroy();
						buffer = newBuffer;
						mBuffers[mMappedDeviceIdx] = buffer;
					}
				}

				// Queue copy/update command
				if (mStagingBuffer != nullptr)
				{
					mStagingBuffer->copy(transferCB, buffer, 0, mMappedOffset, mMappedSize);
					transferCB->getCB()->registerResource(mStagingBuffer, VK_ACCESS_TRANSFER_READ_BIT, VulkanUseFlag::Read);
				}
				else // Staging memory
				{
					buffer->update(transferCB, mStagingMemory, mMappedOffset, mMappedSize);
				}

				transferCB->getCB()->registerResource(buffer, VK_ACCESS_TRANSFER_WRITE_BIT, VulkanUseFlag::Write);

				// We don't actually flush the transfer buffer here since it's an expensive operation, but it's instead
				// done automatically before next "normal" command buffer submission.
			}

			if (mStagingBuffer != nullptr)
			{
				mStagingBuffer->destroy();
				mStagingBuffer = nullptr;
			}

			if(mStagingMemory != nullptr)
			{
				bs_free(mStagingMemory);
				mStagingMemory = nullptr;
			}
		}

		mIsMapped = false;
	}

	void VulkanHardwareBuffer::copyData(HardwareBuffer& srcBuffer, UINT32 srcOffset,
		UINT32 dstOffset, UINT32 length, bool discardWholeBuffer, UINT32 queueIdx)
	{
		if ((dstOffset + length) > mSize)
		{
			LOGERR("Provided offset(" + toString(dstOffset) + ") + length(" + toString(length) + ") "
				   "is larger than the destination buffer " + toString(mSize) + ". Copy operation aborted.");

			return;
		}

		if ((srcOffset + length) > srcBuffer.getSize())
		{
			LOGERR("Provided offset(" + toString(srcOffset) + ") + length(" + toString(length) + ") "
				   "is larger than the source buffer " + toString(srcBuffer.getSize()) + ". Copy operation aborted.");

			return;
		}

		VulkanHardwareBuffer& vkSource = static_cast<VulkanHardwareBuffer&>(srcBuffer);

		VulkanRenderAPI& rapi = static_cast<VulkanRenderAPI&>(RenderAPI::instance());
		VulkanCommandBufferManager& cbManager = gVulkanCBManager();

		GpuQueueType queueType;
		UINT32 localQueueIdx = CommandSyncMask::getQueueIdxAndType(queueIdx, queueType);

		// Perform copy on every device that has both buffers
		for (UINT32 i = 0; i < BS_MAX_DEVICES; i++)
		{
			VulkanBuffer* src = vkSource.mBuffers[i];
			VulkanBuffer* dst = mBuffers[i];

			if (src == nullptr || dst == nullptr)
				continue;

			VulkanDevice& device = *rapi._getDevice(i);
			VulkanTransferBuffer* transferCB = cbManager.getTransferBuffer(i, queueType, localQueueIdx);

			// If either source or destination buffer is currently being written to do need to sync the copy operation so
			// it executes after both are done

			// If destination is being used on the GPU we need to wait until it finishes before writing to it
			UINT32 dstUseMask = dst->getUseInfo(VulkanUseFlag::Read | VulkanUseFlag::Write);

			// If discard is enabled and destination is used, instead of waiting just discard the existing buffer and make a new one
			bool isNormalWrite = true;
			if(dstUseMask != 0 && discardWholeBuffer)
			{
				dst->destroy();

				dst = createBuffer(device, mSize, false, true);
				mBuffers[i] = dst;

				dstUseMask = 0;
				isNormalWrite = false;
			}

			// If source buffer is being written to on the GPU we need to wait until it finishes, before executing copy
			UINT32 srcUseMask = src->getUseInfo(VulkanUseFlag::Write);

			// Wait if anything is using the buffers
			if(dstUseMask != 0 || srcUseMask != 0)
				transferCB->appendMask(dstUseMask | srcUseMask);

			// Check if the destination buffer will still be bound somewhere after the CBs using it finish
			if (isNormalWrite)
			{
				UINT32 useCount = dst->getUseCount();
				UINT32 boundCount = dst->getBoundCount();

				bool isBoundWithoutUse = boundCount > useCount;

				// If destination buffer is queued for some operation on a CB (ignoring the ones we're waiting for), then we
				// need to make a copy of the buffer to avoid modifying its use in the previous operation
				if (isBoundWithoutUse)
				{
					VulkanBuffer* newBuffer = createBuffer(device, mSize, false, true);

					// Avoid copying original contents if the copy completely covers it
					if (dstOffset > 0 || length != mSize)
					{
						dst->copy(transferCB, newBuffer, 0, 0, mSize);

						transferCB->getCB()->registerResource(dst, VK_ACCESS_TRANSFER_READ_BIT, VulkanUseFlag::Read);
					}

					dst->destroy();
					dst = newBuffer;
					mBuffers[i] = dst;
				}
			}

			src->copy(transferCB, dst, srcOffset, dstOffset, length);

			// Notify the command buffer that these resources are being used on it
			transferCB->getCB()->registerResource(src, VK_ACCESS_TRANSFER_READ_BIT, VulkanUseFlag::Read);
			transferCB->getCB()->registerResource(dst, VK_ACCESS_TRANSFER_WRITE_BIT, VulkanUseFlag::Write);

			// We don't actually flush the transfer buffer here since it's an expensive operation, but it's instead
			// done automatically before next "normal" command buffer submission.
		}
	}

	void VulkanHardwareBuffer::readData(UINT32 offset, UINT32 length, void* dest, UINT32 deviceIdx, UINT32 queueIdx)
	{
		void* lockedData = lock(offset, length, GBL_READ_ONLY, deviceIdx, queueIdx);
		memcpy(dest, lockedData, length);
		unlock();
	}

	void VulkanHardwareBuffer::writeData(UINT32 offset, UINT32 length, const void* source, BufferWriteType writeFlags, 
		UINT32 queueIdx)
	{
		GpuLockOptions lockOptions = GBL_WRITE_ONLY_DISCARD_RANGE;

		if (writeFlags == BTW_NO_OVERWRITE)
			lockOptions = GBL_WRITE_ONLY_NO_OVERWRITE;
		else if (writeFlags == BWT_DISCARD)
			lockOptions = GBL_WRITE_ONLY_DISCARD;

		// Write to every device
		for (UINT32 i = 0; i < BS_MAX_DEVICES; i++)
		{
			if (mBuffers[i] == nullptr)
				continue;

			void* lockedData = lock(offset, length, lockOptions, i, queueIdx);
			memcpy(lockedData, source, length);
			unlock();
		}
	}
}}