src/Vulkan/VkDeviceMemory.cpp - SwiftShader - Git at Google

 // Copyright 2018 The SwiftShader Authors. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //    http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 #include "VkDeviceMemory.hpp"
 #include "VkBuffer.hpp"
 #include "VkDevice.hpp"
 #include "VkDeviceMemoryExternalBase.hpp"
 #include "VkImage.hpp"
 #include "VkStringify.hpp"

 #include "VkConfig.hpp"

 namespace vk {

 // Small class describing a given DeviceMemory::ExternalBase derived class.
 // |typeFlagBit| corresponds to the external memory handle type.
 // |instanceSize| is the size of each class instance in bytes.
 // |instanceInit| is a function pointer used to initialize an instance inplace
 // according to a |pAllocateInfo| parameter.
 class ExternalMemoryTraits
 {
 public:
 	VkExternalMemoryHandleTypeFlagBits typeFlagBit;
 	size_t instanceSize;
 	void (*instanceInit)(void *external, const VkMemoryAllocateInfo *pAllocateInfo);
 };

 // Template function that parses a |pAllocateInfo.pNext| chain to verify that
 // it asks for the creation or import of a memory type managed by implementation
 // class T. On success, return true and sets |pTraits| accordingly. Otherwise
 // return false.
 template<typename T>
 static bool parseCreateInfo(const VkMemoryAllocateInfo *pAllocateInfo,
                             ExternalMemoryTraits *pTraits)
 {
 	if(T::SupportsAllocateInfo(pAllocateInfo))
 	{
 		pTraits->typeFlagBit = T::typeFlagBit;
 		pTraits->instanceSize = sizeof(T);
 		pTraits->instanceInit = [](void *external,
 		                           const VkMemoryAllocateInfo *pAllocateInfo) {
 			new(external) T(pAllocateInfo);
 		};
 		return true;
 	}
 	return false;
 }

 // DeviceMemory::ExternalBase implementation that uses host memory.
 // Not really external, but makes everything simpler.
 class DeviceMemoryHostExternalBase : public DeviceMemory::ExternalBase
 {
 public:
 	// Does not support any external memory type at all.
 	static const VkExternalMemoryHandleTypeFlagBits typeFlagBit = (VkExternalMemoryHandleTypeFlagBits)0;

 	// Always return true as is used as a fallback in findTraits() below.
 	static bool SupportsAllocateInfo(const VkMemoryAllocateInfo *pAllocateInfo)
 	{
 		return true;
 	}

 	DeviceMemoryHostExternalBase(const VkMemoryAllocateInfo *pAllocateInfo) {}

 	VkResult allocate(size_t size, void **pBuffer) override
 	{
 		buffer = vk::allocate(size, REQUIRED_MEMORY_ALIGNMENT, DEVICE_MEMORY);
 		if(!buffer)
 		{
 			return VK_ERROR_OUT_OF_DEVICE_MEMORY;
 		}

 		*pBuffer = buffer;
 		return VK_SUCCESS;
 	}

 	void deallocate(void * /* buffer */, size_t size) override
 	{
 		vk::deallocate(buffer, DEVICE_MEMORY);
 		buffer = nullptr;
 	}

 	VkExternalMemoryHandleTypeFlagBits getFlagBit() const override
 	{
 		return typeFlagBit;
 	}

 #ifdef SWIFTSHADER_DEVICE_MEMORY_REPORT
 	uint64_t getMemoryObjectId() const override
 	{
 		return (uint64_t)buffer;
 	}
 #endif  // SWIFTSHADER_DEVICE_MEMORY_REPORT

 private:
 	void *buffer = nullptr;
 };

 }  // namespace vk

 // Host-allocated memory and host-mapped foreign memory
 class ExternalMemoryHost : public vk::DeviceMemory::ExternalBase
 {
 public:
 	struct AllocateInfo
 	{
 		bool supported = false;
 		void *hostPointer = nullptr;

 		AllocateInfo() = default;

 		AllocateInfo(const VkMemoryAllocateInfo *pAllocateInfo)
 		{
 			const auto *createInfo = reinterpret_cast<const VkBaseInStructure *>(pAllocateInfo->pNext);
 			while(createInfo)
 			{
 				switch(createInfo->sType)
 				{
 					case VK_STRUCTURE_TYPE_IMPORT_MEMORY_HOST_POINTER_INFO_EXT:
 					{
 						const auto *importInfo = reinterpret_cast<const VkImportMemoryHostPointerInfoEXT *>(createInfo);

 						if(importInfo->handleType != VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT && importInfo->handleType != VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT)
 						{
 							UNSUPPORTED("importInfo->handleType");
 						}
 						hostPointer = importInfo->pHostPointer;
 						supported = true;
 						break;
 					}
 					default:
 						break;
 				}
 				createInfo = createInfo->pNext;
 			}
 		}
 	};

 	static const VkExternalMemoryHandleTypeFlagBits typeFlagBit = (VkExternalMemoryHandleTypeFlagBits)(VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT | VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT);

 	static bool SupportsAllocateInfo(const VkMemoryAllocateInfo *pAllocateInfo)
 	{
 		AllocateInfo info(pAllocateInfo);
 		return info.supported;
 	}

 	explicit ExternalMemoryHost(const VkMemoryAllocateInfo *pAllocateInfo)
 	    : allocateInfo(pAllocateInfo)
 	{
 	}

 	VkResult allocate(size_t size, void **pBuffer) override
 	{
 		if(allocateInfo.supported)
 		{
 			*pBuffer = allocateInfo.hostPointer;
 			return VK_SUCCESS;
 		}
 		return VK_ERROR_INVALID_EXTERNAL_HANDLE;
 	}

 	void deallocate(void *buffer, size_t size) override
 	{}

 	VkExternalMemoryHandleTypeFlagBits getFlagBit() const override
 	{
 		return typeFlagBit;
 	}

 private:
 	AllocateInfo allocateInfo;
 };

 #if SWIFTSHADER_EXTERNAL_MEMORY_OPAQUE_FD

 // Helper struct to parse the VkMemoryAllocateInfo.pNext chain and
 // extract relevant information related to the handle type supported
 // by this DeviceMemory;:ExternalBase subclass.
 struct OpaqueFdAllocateInfo
 {
 	bool importFd = false;
 	bool exportFd = false;
 	int fd = -1;

 	OpaqueFdAllocateInfo() = default;

 	// Parse the VkMemoryAllocateInfo.pNext chain to initialize an OpaqueFdAllocateInfo.
 	OpaqueFdAllocateInfo(const VkMemoryAllocateInfo *pAllocateInfo)
 	{
 		const auto *createInfo = reinterpret_cast<const VkBaseInStructure *>(pAllocateInfo->pNext);
 		while(createInfo)
 		{
 			switch(createInfo->sType)
 			{
 				case VK_STRUCTURE_TYPE_IMPORT_MEMORY_FD_INFO_KHR:
 				{
 					const auto *importInfo = reinterpret_cast<const VkImportMemoryFdInfoKHR *>(createInfo);

 					if(importInfo->handleType != VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT)
 					{
 						UNSUPPORTED("VkImportMemoryFdInfoKHR::handleType %d", int(importInfo->handleType));
 					}
 					importFd = true;
 					fd = importInfo->fd;
 				}
 				break;
 				case VK_STRUCTURE_TYPE_EXPORT_MEMORY_ALLOCATE_INFO:
 				{
 					const auto *exportInfo = reinterpret_cast<const VkExportMemoryAllocateInfo *>(createInfo);

 					if(exportInfo->handleTypes != VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT)
 					{
 						UNSUPPORTED("VkExportMemoryAllocateInfo::handleTypes %d", int(exportInfo->handleTypes));
 					}
 					exportFd = true;
 				}
 				break;
 				case VK_STRUCTURE_TYPE_MEMORY_DEDICATED_ALLOCATE_INFO:
 					// This can safely be ignored, as the Vulkan spec mentions:
 					// "If the pNext chain includes a VkMemoryDedicatedAllocateInfo structure, then that structure
 					//  includes a handle of the sole buffer or image resource that the memory *can* be bound to."
 					break;
 				default:
 					WARN("VkMemoryAllocateInfo->pNext sType = %s", vk::Stringify(createInfo->sType).c_str());
 			}
 			createInfo = createInfo->pNext;
 		}
 	}
 };

 #	if defined(__APPLE__)
 #		include "VkDeviceMemoryExternalMac.hpp"
 #	elif defined(__linux__) && !defined(__ANDROID__)
 #		include "VkDeviceMemoryExternalLinux.hpp"
 #	else
 #		error "Missing VK_KHR_external_memory_fd implementation for this platform!"
 #	endif
 #endif

 #if SWIFTSHADER_EXTERNAL_MEMORY_ANDROID_HARDWARE_BUFFER
 #	if defined(__ANDROID__)
 #		include "VkDeviceMemoryExternalAndroid.hpp"
 #	else
 #		error "Missing VK_ANDROID_external_memory_android_hardware_buffer implementation for this platform!"
 #	endif
 #endif

 #if VK_USE_PLATFORM_FUCHSIA
 #	include "VkDeviceMemoryExternalFuchsia.hpp"
 #endif

 namespace vk {

 static void findTraits(const VkMemoryAllocateInfo *pAllocateInfo,
                        ExternalMemoryTraits *pTraits)
 {
 #if SWIFTSHADER_EXTERNAL_MEMORY_ANDROID_HARDWARE_BUFFER
 	if(parseCreateInfo<AHardwareBufferExternalMemory>(pAllocateInfo, pTraits))
 	{
 		return;
 	}
 #endif
 #if SWIFTSHADER_EXTERNAL_MEMORY_OPAQUE_FD
 	if(parseCreateInfo<OpaqueFdExternalMemory>(pAllocateInfo, pTraits))
 	{
 		return;
 	}
 #endif
 #if VK_USE_PLATFORM_FUCHSIA
 	if(parseCreateInfo<zircon::VmoExternalMemory>(pAllocateInfo, pTraits))
 	{
 		return;
 	}
 #endif
 	if(parseCreateInfo<ExternalMemoryHost>(pAllocateInfo, pTraits))
 	{
 		return;
 	}
 	parseCreateInfo<DeviceMemoryHostExternalBase>(pAllocateInfo, pTraits);
 }

 DeviceMemory::DeviceMemory(const VkMemoryAllocateInfo *pAllocateInfo, void *mem, Device *pDevice)
     : size(pAllocateInfo->allocationSize)
     , memoryTypeIndex(pAllocateInfo->memoryTypeIndex)
     , device(pDevice)
 {
 	ASSERT(size);

 	ExternalMemoryTraits traits;
 	findTraits(pAllocateInfo, &traits);
 	traits.instanceInit(mem, pAllocateInfo);
 	external = reinterpret_cast<ExternalBase *>(mem);
 	external->setDevicePtr(device);
 }

 void DeviceMemory::destroy(const VkAllocationCallbacks *pAllocator)
 {
 #ifdef SWIFTSHADER_DEVICE_MEMORY_REPORT
 	device->emitDeviceMemoryReport(external->isImport() ? VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_UNIMPORT_EXT : VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_FREE_EXT, external->getMemoryObjectId(), 0 /* size */, VK_OBJECT_TYPE_DEVICE_MEMORY, (uint64_t)(void *)VkDeviceMemory(*this));
 #endif  // SWIFTSHADER_DEVICE_MEMORY_REPORT
 	if(buffer)
 	{
 		external->deallocate(buffer, size);
 		buffer = nullptr;
 	}
 	external->~ExternalBase();  // Call virtual destructor in place.
 	vk::deallocate(external, pAllocator);
 }

 size_t DeviceMemory::ComputeRequiredAllocationSize(const VkMemoryAllocateInfo *pAllocateInfo)
 {
 	ExternalMemoryTraits traits;
 	findTraits(pAllocateInfo, &traits);
 	return traits.instanceSize;
 }

 VkResult DeviceMemory::allocate()
 {
 	if(size > MAX_MEMORY_ALLOCATION_SIZE)
 	{
 #ifdef SWIFTSHADER_DEVICE_MEMORY_REPORT
 		device->emitDeviceMemoryReport(VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_ALLOCATION_FAILED_EXT, 0 /* memoryObjectId */, size, VK_OBJECT_TYPE_DEVICE_MEMORY, 0 /* objectHandle */);
 #endif  // SWIFTSHADER_DEVICE_MEMORY_REPORT
 		return VK_ERROR_OUT_OF_DEVICE_MEMORY;
 	}

 	VkResult result = VK_SUCCESS;
 	if(!buffer)
 	{
 		result = external->allocate(size, &buffer);
 	}
 #ifdef SWIFTSHADER_DEVICE_MEMORY_REPORT
 	if(result == VK_SUCCESS)
 	{
 		device->emitDeviceMemoryReport(external->isImport() ? VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_IMPORT_EXT : VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_ALLOCATE_EXT, external->getMemoryObjectId(), size, VK_OBJECT_TYPE_DEVICE_MEMORY, (uint64_t)(void *)VkDeviceMemory(*this));
 	}
 	else
 	{
 		device->emitDeviceMemoryReport(VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_ALLOCATION_FAILED_EXT, 0 /* memoryObjectId */, size, VK_OBJECT_TYPE_DEVICE_MEMORY, 0 /* objectHandle */);
 	}
 #endif  // SWIFTSHADER_DEVICE_MEMORY_REPORT
 	return result;
 }

 VkResult DeviceMemory::map(VkDeviceSize pOffset, VkDeviceSize pSize, void **ppData)
 {
 	*ppData = getOffsetPointer(pOffset);

 	return VK_SUCCESS;
 }

 VkDeviceSize DeviceMemory::getCommittedMemoryInBytes() const
 {
 	return size;
 }

 void *DeviceMemory::getOffsetPointer(VkDeviceSize pOffset) const
 {
 	ASSERT(buffer);
 	return reinterpret_cast<char *>(buffer) + pOffset;
 }

 bool DeviceMemory::checkExternalMemoryHandleType(
     VkExternalMemoryHandleTypeFlags supportedHandleTypes) const
 {
 	if(!supportedHandleTypes)
 	{
 		// This image or buffer does not need to be stored on external
 		// memory, so this check should always pass.
 		return true;
 	}
 	VkExternalMemoryHandleTypeFlagBits handle_type_bit = external->getFlagBit();
 	if(!handle_type_bit)
 	{
 		// This device memory is not external and can accomodate
 		// any image or buffer as well.
 		return true;
 	}
 	// Return true only if the external memory type is compatible with the
 	// one specified during VkCreate{Image,Buffer}(), through a
 	// VkExternalMemory{Image,Buffer}AllocateInfo struct.
 	return (supportedHandleTypes & handle_type_bit) != 0;
 }

 bool DeviceMemory::hasExternalImageProperties() const
 {
 	return external && external->hasExternalImageProperties();
 }

 int DeviceMemory::externalImageRowPitchBytes(VkImageAspectFlagBits aspect) const
 {
 	if(external)
 	{
 		return external->externalImageRowPitchBytes(aspect);
 	}

 	// This function should never be called on non-external memory.
 	ASSERT(false);
 	return -1;
 }

 VkDeviceSize DeviceMemory::externalImageMemoryOffset(VkImageAspectFlagBits aspect) const
 {
 	if(external)
 	{
 		return external->externalImageMemoryOffset(aspect);
 	}

 	// This function should never be called on non-external memory.
 	ASSERT(false);
 	return -1;
 }

 #if SWIFTSHADER_EXTERNAL_MEMORY_OPAQUE_FD
 VkResult DeviceMemory::exportFd(int *pFd) const
 {
 	return external->exportFd(pFd);
 }
 #endif

 #if SWIFTSHADER_EXTERNAL_MEMORY_ANDROID_HARDWARE_BUFFER
 VkResult DeviceMemory::exportAndroidHardwareBuffer(struct AHardwareBuffer **pAhb) const
 {
 	if(external->getFlagBit() != VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID)
 	{
 		return VK_ERROR_OUT_OF_HOST_MEMORY;
 	}
 	return static_cast<AHardwareBufferExternalMemory *>(external)->exportAndroidHardwareBuffer(pAhb);
 }

 VkResult DeviceMemory::GetAndroidHardwareBufferProperties(VkDevice &ahbDevice, const struct AHardwareBuffer *buffer, VkAndroidHardwareBufferPropertiesANDROID *pProperties)
 {
 	return AHardwareBufferExternalMemory::GetAndroidHardwareBufferProperties(ahbDevice, buffer, pProperties);
 }
 #endif

 #if VK_USE_PLATFORM_FUCHSIA
 VkResult DeviceMemory::exportHandle(zx_handle_t *pHandle) const
 {
 	return external->exportHandle(pHandle);
 }
 #endif

 }  // namespace vk
	// Copyright 2018 The SwiftShader Authors. All Rights Reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	#include "VkDeviceMemory.hpp"
	#include "VkBuffer.hpp"
	#include "VkDevice.hpp"
	#include "VkDeviceMemoryExternalBase.hpp"
	#include "VkImage.hpp"
	#include "VkStringify.hpp"

	#include "VkConfig.hpp"

	namespace vk {

	// Small class describing a given DeviceMemory::ExternalBase derived class.
	// \|typeFlagBit\| corresponds to the external memory handle type.
	// \|instanceSize\| is the size of each class instance in bytes.
	// \|instanceInit\| is a function pointer used to initialize an instance inplace
	// according to a \|pAllocateInfo\| parameter.
	class ExternalMemoryTraits
	{
	public:
	VkExternalMemoryHandleTypeFlagBits typeFlagBit;
	size_t instanceSize;
	void (instanceInit)(void external, const VkMemoryAllocateInfo *pAllocateInfo);
	};

	// Template function that parses a \|pAllocateInfo.pNext\| chain to verify that
	// it asks for the creation or import of a memory type managed by implementation
	// class T. On success, return true and sets \|pTraits\| accordingly. Otherwise
	// return false.
	template<typename T>
	static bool parseCreateInfo(const VkMemoryAllocateInfo *pAllocateInfo,
	ExternalMemoryTraits *pTraits)
	{
	if(T::SupportsAllocateInfo(pAllocateInfo))
	{
	pTraits->typeFlagBit = T::typeFlagBit;
	pTraits->instanceSize = sizeof(T);
	pTraits->instanceInit = [](void *external,
	const VkMemoryAllocateInfo *pAllocateInfo) {
	new(external) T(pAllocateInfo);
	};
	return true;
	}
	return false;
	}

	// DeviceMemory::ExternalBase implementation that uses host memory.
	// Not really external, but makes everything simpler.
	class DeviceMemoryHostExternalBase : public DeviceMemory::ExternalBase
	{
	public:
	// Does not support any external memory type at all.
	static const VkExternalMemoryHandleTypeFlagBits typeFlagBit = (VkExternalMemoryHandleTypeFlagBits)0;

	// Always return true as is used as a fallback in findTraits() below.
	static bool SupportsAllocateInfo(const VkMemoryAllocateInfo *pAllocateInfo)
	{
	return true;
	}

	DeviceMemoryHostExternalBase(const VkMemoryAllocateInfo *pAllocateInfo) {}

	VkResult allocate(size_t size, void **pBuffer) override
	{
	buffer = vk::allocate(size, REQUIRED_MEMORY_ALIGNMENT, DEVICE_MEMORY);
	if(!buffer)
	{
	return VK_ERROR_OUT_OF_DEVICE_MEMORY;
	}

	*pBuffer = buffer;
	return VK_SUCCESS;
	}

	void deallocate(void * /* buffer */, size_t size) override
	{
	vk::deallocate(buffer, DEVICE_MEMORY);
	buffer = nullptr;
	}

	VkExternalMemoryHandleTypeFlagBits getFlagBit() const override
	{
	return typeFlagBit;
	}

	#ifdef SWIFTSHADER_DEVICE_MEMORY_REPORT
	uint64_t getMemoryObjectId() const override
	{
	return (uint64_t)buffer;
	}
	#endif // SWIFTSHADER_DEVICE_MEMORY_REPORT

	private:
	void *buffer = nullptr;
	};

	} // namespace vk

	// Host-allocated memory and host-mapped foreign memory
	class ExternalMemoryHost : public vk::DeviceMemory::ExternalBase
	{
	public:
	struct AllocateInfo
	{
	bool supported = false;
	void *hostPointer = nullptr;

	AllocateInfo() = default;

	AllocateInfo(const VkMemoryAllocateInfo *pAllocateInfo)
	{
	const auto createInfo = reinterpret_cast<const VkBaseInStructure >(pAllocateInfo->pNext);
	while(createInfo)
	{
	switch(createInfo->sType)
	{
	case VK_STRUCTURE_TYPE_IMPORT_MEMORY_HOST_POINTER_INFO_EXT:
	{
	const auto importInfo = reinterpret_cast<const VkImportMemoryHostPointerInfoEXT >(createInfo);

	if(importInfo->handleType != VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT && importInfo->handleType != VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT)
	{
	UNSUPPORTED("importInfo->handleType");
	}
	hostPointer = importInfo->pHostPointer;
	supported = true;
	break;
	}
	default:
	break;
	}
	createInfo = createInfo->pNext;
	}
	}
	};

	static const VkExternalMemoryHandleTypeFlagBits typeFlagBit = (VkExternalMemoryHandleTypeFlagBits)(VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT \| VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT);

	static bool SupportsAllocateInfo(const VkMemoryAllocateInfo *pAllocateInfo)
	{
	AllocateInfo info(pAllocateInfo);
	return info.supported;
	}

	explicit ExternalMemoryHost(const VkMemoryAllocateInfo *pAllocateInfo)
	: allocateInfo(pAllocateInfo)
	{
	}

	VkResult allocate(size_t size, void **pBuffer) override
	{
	if(allocateInfo.supported)
	{
	*pBuffer = allocateInfo.hostPointer;
	return VK_SUCCESS;
	}
	return VK_ERROR_INVALID_EXTERNAL_HANDLE;
	}

	void deallocate(void *buffer, size_t size) override
	{}

	VkExternalMemoryHandleTypeFlagBits getFlagBit() const override
	{
	return typeFlagBit;
	}

	private:
	AllocateInfo allocateInfo;
	};

	#if SWIFTSHADER_EXTERNAL_MEMORY_OPAQUE_FD

	// Helper struct to parse the VkMemoryAllocateInfo.pNext chain and
	// extract relevant information related to the handle type supported
	// by this DeviceMemory;:ExternalBase subclass.
	struct OpaqueFdAllocateInfo
	{
	bool importFd = false;
	bool exportFd = false;
	int fd = -1;

	OpaqueFdAllocateInfo() = default;

	// Parse the VkMemoryAllocateInfo.pNext chain to initialize an OpaqueFdAllocateInfo.
	OpaqueFdAllocateInfo(const VkMemoryAllocateInfo *pAllocateInfo)
	{
	const auto createInfo = reinterpret_cast<const VkBaseInStructure >(pAllocateInfo->pNext);
	while(createInfo)
	{
	switch(createInfo->sType)
	{
	case VK_STRUCTURE_TYPE_IMPORT_MEMORY_FD_INFO_KHR:
	{
	const auto importInfo = reinterpret_cast<const VkImportMemoryFdInfoKHR >(createInfo);

	if(importInfo->handleType != VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT)
	{
	UNSUPPORTED("VkImportMemoryFdInfoKHR::handleType %d", int(importInfo->handleType));
	}
	importFd = true;
	fd = importInfo->fd;
	}
	break;
	case VK_STRUCTURE_TYPE_EXPORT_MEMORY_ALLOCATE_INFO:
	{
	const auto exportInfo = reinterpret_cast<const VkExportMemoryAllocateInfo >(createInfo);

	if(exportInfo->handleTypes != VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT)
	{
	UNSUPPORTED("VkExportMemoryAllocateInfo::handleTypes %d", int(exportInfo->handleTypes));
	}
	exportFd = true;
	}
	break;
	case VK_STRUCTURE_TYPE_MEMORY_DEDICATED_ALLOCATE_INFO:
	// This can safely be ignored, as the Vulkan spec mentions:
	// "If the pNext chain includes a VkMemoryDedicatedAllocateInfo structure, then that structure
	// includes a handle of the sole buffer or image resource that the memory can be bound to."
	break;
	default:
	WARN("VkMemoryAllocateInfo->pNext sType = %s", vk::Stringify(createInfo->sType).c_str());
	}
	createInfo = createInfo->pNext;
	}
	}
	};

	# if defined(__APPLE__)
	# include "VkDeviceMemoryExternalMac.hpp"
	# elif defined(__linux__) && !defined(__ANDROID__)
	# include "VkDeviceMemoryExternalLinux.hpp"
	# else
	# error "Missing VK_KHR_external_memory_fd implementation for this platform!"
	# endif
	#endif

	#if SWIFTSHADER_EXTERNAL_MEMORY_ANDROID_HARDWARE_BUFFER
	# if defined(__ANDROID__)
	# include "VkDeviceMemoryExternalAndroid.hpp"
	# else
	# error "Missing VK_ANDROID_external_memory_android_hardware_buffer implementation for this platform!"
	# endif
	#endif

	#if VK_USE_PLATFORM_FUCHSIA
	# include "VkDeviceMemoryExternalFuchsia.hpp"
	#endif

	namespace vk {

	static void findTraits(const VkMemoryAllocateInfo *pAllocateInfo,
	ExternalMemoryTraits *pTraits)
	{
	#if SWIFTSHADER_EXTERNAL_MEMORY_ANDROID_HARDWARE_BUFFER
	if(parseCreateInfo<AHardwareBufferExternalMemory>(pAllocateInfo, pTraits))
	{
	return;
	}
	#endif
	#if SWIFTSHADER_EXTERNAL_MEMORY_OPAQUE_FD
	if(parseCreateInfo<OpaqueFdExternalMemory>(pAllocateInfo, pTraits))
	{
	return;
	}
	#endif
	#if VK_USE_PLATFORM_FUCHSIA
	if(parseCreateInfo<zircon::VmoExternalMemory>(pAllocateInfo, pTraits))
	{
	return;
	}
	#endif
	if(parseCreateInfo<ExternalMemoryHost>(pAllocateInfo, pTraits))
	{
	return;
	}
	parseCreateInfo<DeviceMemoryHostExternalBase>(pAllocateInfo, pTraits);
	}

	DeviceMemory::DeviceMemory(const VkMemoryAllocateInfo pAllocateInfo, void mem, Device *pDevice)
	: size(pAllocateInfo->allocationSize)
	, memoryTypeIndex(pAllocateInfo->memoryTypeIndex)
	, device(pDevice)
	{
	ASSERT(size);

	ExternalMemoryTraits traits;
	findTraits(pAllocateInfo, &traits);
	traits.instanceInit(mem, pAllocateInfo);
	external = reinterpret_cast<ExternalBase *>(mem);
	external->setDevicePtr(device);
	}

	void DeviceMemory::destroy(const VkAllocationCallbacks *pAllocator)
	{
	#ifdef SWIFTSHADER_DEVICE_MEMORY_REPORT
	device->emitDeviceMemoryReport(external->isImport() ? VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_UNIMPORT_EXT : VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_FREE_EXT, external->getMemoryObjectId(), 0 /* size /, VK_OBJECT_TYPE_DEVICE_MEMORY, (uint64_t)(void )VkDeviceMemory(*this));
	#endif // SWIFTSHADER_DEVICE_MEMORY_REPORT
	if(buffer)
	{
	external->deallocate(buffer, size);
	buffer = nullptr;
	}
	external->~ExternalBase(); // Call virtual destructor in place.
	vk::deallocate(external, pAllocator);
	}

	size_t DeviceMemory::ComputeRequiredAllocationSize(const VkMemoryAllocateInfo *pAllocateInfo)
	{
	ExternalMemoryTraits traits;
	findTraits(pAllocateInfo, &traits);
	return traits.instanceSize;
	}

	VkResult DeviceMemory::allocate()
	{
	if(size > MAX_MEMORY_ALLOCATION_SIZE)
	{
	#ifdef SWIFTSHADER_DEVICE_MEMORY_REPORT
	device->emitDeviceMemoryReport(VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_ALLOCATION_FAILED_EXT, 0 /* memoryObjectId /, size, VK_OBJECT_TYPE_DEVICE_MEMORY, 0 / objectHandle */);
	#endif // SWIFTSHADER_DEVICE_MEMORY_REPORT
	return VK_ERROR_OUT_OF_DEVICE_MEMORY;
	}

	VkResult result = VK_SUCCESS;
	if(!buffer)
	{
	result = external->allocate(size, &buffer);
	}
	#ifdef SWIFTSHADER_DEVICE_MEMORY_REPORT
	if(result == VK_SUCCESS)
	{
	device->emitDeviceMemoryReport(external->isImport() ? VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_IMPORT_EXT : VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_ALLOCATE_EXT, external->getMemoryObjectId(), size, VK_OBJECT_TYPE_DEVICE_MEMORY, (uint64_t)(void )VkDeviceMemory(this));
	}
	else
	{
	device->emitDeviceMemoryReport(VK_DEVICE_MEMORY_REPORT_EVENT_TYPE_ALLOCATION_FAILED_EXT, 0 /* memoryObjectId /, size, VK_OBJECT_TYPE_DEVICE_MEMORY, 0 / objectHandle */);
	}
	#endif // SWIFTSHADER_DEVICE_MEMORY_REPORT
	return result;
	}

	VkResult DeviceMemory::map(VkDeviceSize pOffset, VkDeviceSize pSize, void **ppData)
	{
	*ppData = getOffsetPointer(pOffset);

	return VK_SUCCESS;
	}

	VkDeviceSize DeviceMemory::getCommittedMemoryInBytes() const
	{
	return size;
	}

	void *DeviceMemory::getOffsetPointer(VkDeviceSize pOffset) const
	{
	ASSERT(buffer);
	return reinterpret_cast<char *>(buffer) + pOffset;
	}

	bool DeviceMemory::checkExternalMemoryHandleType(
	VkExternalMemoryHandleTypeFlags supportedHandleTypes) const
	{
	if(!supportedHandleTypes)
	{
	// This image or buffer does not need to be stored on external
	// memory, so this check should always pass.
	return true;
	}
	VkExternalMemoryHandleTypeFlagBits handle_type_bit = external->getFlagBit();
	if(!handle_type_bit)
	{
	// This device memory is not external and can accomodate
	// any image or buffer as well.
	return true;
	}
	// Return true only if the external memory type is compatible with the
	// one specified during VkCreate{Image,Buffer}(), through a
	// VkExternalMemory{Image,Buffer}AllocateInfo struct.
	return (supportedHandleTypes & handle_type_bit) != 0;
	}

	bool DeviceMemory::hasExternalImageProperties() const
	{
	return external && external->hasExternalImageProperties();
	}

	int DeviceMemory::externalImageRowPitchBytes(VkImageAspectFlagBits aspect) const
	{
	if(external)
	{
	return external->externalImageRowPitchBytes(aspect);
	}

	// This function should never be called on non-external memory.
	ASSERT(false);
	return -1;
	}

	VkDeviceSize DeviceMemory::externalImageMemoryOffset(VkImageAspectFlagBits aspect) const
	{
	if(external)
	{
	return external->externalImageMemoryOffset(aspect);
	}

	// This function should never be called on non-external memory.
	ASSERT(false);
	return -1;
	}

	#if SWIFTSHADER_EXTERNAL_MEMORY_OPAQUE_FD
	VkResult DeviceMemory::exportFd(int *pFd) const
	{
	return external->exportFd(pFd);
	}
	#endif

	#if SWIFTSHADER_EXTERNAL_MEMORY_ANDROID_HARDWARE_BUFFER
	VkResult DeviceMemory::exportAndroidHardwareBuffer(struct AHardwareBuffer **pAhb) const
	{
	if(external->getFlagBit() != VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID)
	{
	return VK_ERROR_OUT_OF_HOST_MEMORY;
	}
	return static_cast<AHardwareBufferExternalMemory *>(external)->exportAndroidHardwareBuffer(pAhb);
	}

	VkResult DeviceMemory::GetAndroidHardwareBufferProperties(VkDevice &ahbDevice, const struct AHardwareBuffer buffer, VkAndroidHardwareBufferPropertiesANDROID pProperties)
	{
	return AHardwareBufferExternalMemory::GetAndroidHardwareBufferProperties(ahbDevice, buffer, pProperties);
	}
	#endif

	#if VK_USE_PLATFORM_FUCHSIA
	VkResult DeviceMemory::exportHandle(zx_handle_t *pHandle) const
	{
	return external->exportHandle(pHandle);
	}
	#endif

	} // namespace vk