// Copyright 2017 The Dawn Authors
//
// 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 "dawn_native/vulkan/DeviceVk.h"

#include "common/Platform.h"
#include "dawn_native/BackendConnection.h"
#include "dawn_native/Commands.h"
#include "dawn_native/Error.h"
#include "dawn_native/ErrorData.h"
#include "dawn_native/VulkanBackend.h"
#include "dawn_native/vulkan/AdapterVk.h"
#include "dawn_native/vulkan/BackendVk.h"
#include "dawn_native/vulkan/BindGroupLayoutVk.h"
#include "dawn_native/vulkan/BindGroupVk.h"
#include "dawn_native/vulkan/BufferVk.h"
#include "dawn_native/vulkan/CommandBufferVk.h"
#include "dawn_native/vulkan/ComputePipelineVk.h"
#include "dawn_native/vulkan/FencedDeleter.h"
#include "dawn_native/vulkan/PipelineLayoutVk.h"
#include "dawn_native/vulkan/QueueVk.h"
#include "dawn_native/vulkan/RenderPassCache.h"
#include "dawn_native/vulkan/RenderPipelineVk.h"
#include "dawn_native/vulkan/ResourceMemoryAllocatorVk.h"
#include "dawn_native/vulkan/SamplerVk.h"
#include "dawn_native/vulkan/ShaderModuleVk.h"
#include "dawn_native/vulkan/StagingBufferVk.h"
#include "dawn_native/vulkan/SwapChainVk.h"
#include "dawn_native/vulkan/TextureVk.h"
#include "dawn_native/vulkan/VulkanError.h"

namespace dawn_native { namespace vulkan {

    // static
    ResultOrError<Device*> Device::Create(Adapter* adapter, const DeviceDescriptor* descriptor) {
        Ref<Device> device = AcquireRef(new Device(adapter, descriptor));
        DAWN_TRY(device->Initialize());
        return device.Detach();
    }

    Device::Device(Adapter* adapter, const DeviceDescriptor* descriptor)
        : DeviceBase(adapter, descriptor) {
        InitTogglesFromDriver();
    }

    MaybeError Device::Initialize() {
        // Copy the adapter's device info to the device so that we can change the "knobs"
        mDeviceInfo = ToBackend(GetAdapter())->GetDeviceInfo();

        // Initialize the "instance" procs of our local function table.
        VulkanFunctions* functions = GetMutableFunctions();
        *functions = ToBackend(GetAdapter())->GetBackend()->GetFunctions();

        // Two things are crucial if device initialization fails: the function pointers to destroy
        // objects, and the fence deleter that calls these functions. Do not do anything before
        // these two are set up, so that a failed initialization doesn't cause a crash in
        // ShutDownImpl()
        {
            VkPhysicalDevice physicalDevice = ToBackend(GetAdapter())->GetPhysicalDevice();

            VulkanDeviceKnobs usedDeviceKnobs = {};
            DAWN_TRY_ASSIGN(usedDeviceKnobs, CreateDevice(physicalDevice));
            *static_cast<VulkanDeviceKnobs*>(&mDeviceInfo) = usedDeviceKnobs;

            DAWN_TRY(functions->LoadDeviceProcs(mVkDevice, mDeviceInfo));

            // The queue can be loaded before the fenced deleter because their lifetime is tied to
            // the device.
            GatherQueueFromDevice();

            mDeleter = std::make_unique<FencedDeleter>(this);
        }

        mMapRequestTracker = std::make_unique<MapRequestTracker>(this);
        mRenderPassCache = std::make_unique<RenderPassCache>(this);
        mResourceMemoryAllocator = std::make_unique<ResourceMemoryAllocator>(this);

        mExternalMemoryService = std::make_unique<external_memory::Service>(this);
        mExternalSemaphoreService = std::make_unique<external_semaphore::Service>(this);

        DAWN_TRY(PrepareRecordingContext());

        // The environment can request to use D32S8 or D24S8 when it's not available. Override
        // the decision if it is not applicable.
        ApplyDepth24PlusS8Toggle();

        return DeviceBase::Initialize(new Queue(this));
    }

    Device::~Device() {
        ShutDownBase();
    }

    ResultOrError<BindGroupBase*> Device::CreateBindGroupImpl(
        const BindGroupDescriptor* descriptor) {
        return BindGroup::Create(this, descriptor);
    }
    ResultOrError<BindGroupLayoutBase*> Device::CreateBindGroupLayoutImpl(
        const BindGroupLayoutDescriptor* descriptor) {
        return BindGroupLayout::Create(this, descriptor);
    }
    ResultOrError<BufferBase*> Device::CreateBufferImpl(const BufferDescriptor* descriptor) {
        return Buffer::Create(this, descriptor);
    }
    CommandBufferBase* Device::CreateCommandBuffer(CommandEncoder* encoder,
                                                   const CommandBufferDescriptor* descriptor) {
        return CommandBuffer::Create(encoder, descriptor);
    }
    ResultOrError<ComputePipelineBase*> Device::CreateComputePipelineImpl(
        const ComputePipelineDescriptor* descriptor) {
        return ComputePipeline::Create(this, descriptor);
    }
    ResultOrError<PipelineLayoutBase*> Device::CreatePipelineLayoutImpl(
        const PipelineLayoutDescriptor* descriptor) {
        return PipelineLayout::Create(this, descriptor);
    }
    ResultOrError<RenderPipelineBase*> Device::CreateRenderPipelineImpl(
        const RenderPipelineDescriptor* descriptor) {
        return RenderPipeline::Create(this, descriptor);
    }
    ResultOrError<SamplerBase*> Device::CreateSamplerImpl(const SamplerDescriptor* descriptor) {
        return Sampler::Create(this, descriptor);
    }
    ResultOrError<ShaderModuleBase*> Device::CreateShaderModuleImpl(
        const ShaderModuleDescriptor* descriptor) {
        return ShaderModule::Create(this, descriptor);
    }
    ResultOrError<SwapChainBase*> Device::CreateSwapChainImpl(
        const SwapChainDescriptor* descriptor) {
        return SwapChain::Create(this, descriptor);
    }
    ResultOrError<NewSwapChainBase*> Device::CreateSwapChainImpl(
        Surface* surface,
        NewSwapChainBase* previousSwapChain,
        const SwapChainDescriptor* descriptor) {
        return DAWN_VALIDATION_ERROR("New swapchains not implemented.");
    }
    ResultOrError<Ref<TextureBase>> Device::CreateTextureImpl(const TextureDescriptor* descriptor) {
        return Texture::Create(this, descriptor);
    }
    ResultOrError<TextureViewBase*> Device::CreateTextureViewImpl(
        TextureBase* texture,
        const TextureViewDescriptor* descriptor) {
        return TextureView::Create(texture, descriptor);
    }

    MaybeError Device::TickImpl() {
        CheckPassedSerials();
        RecycleCompletedCommands();

        Serial completedSerial = GetCompletedCommandSerial();

        for (Ref<BindGroupLayout>& bgl :
             mBindGroupLayoutsPendingDeallocation.IterateUpTo(completedSerial)) {
            bgl->FinishDeallocation(completedSerial);
        }
        mBindGroupLayoutsPendingDeallocation.ClearUpTo(completedSerial);

        mMapRequestTracker->Tick(completedSerial);
        mResourceMemoryAllocator->Tick(completedSerial);
        mDeleter->Tick(completedSerial);

        if (mRecordingContext.used) {
            DAWN_TRY(SubmitPendingCommands());
        } else if (completedSerial == GetLastSubmittedCommandSerial()) {
            // If there's no GPU work in flight we still need to artificially increment the serial
            // so that CPU operations waiting on GPU completion can know they don't have to wait.
            ArtificiallyIncrementSerials();
        }

        return {};
    }

    VkInstance Device::GetVkInstance() const {
        return ToBackend(GetAdapter())->GetBackend()->GetVkInstance();
    }
    const VulkanDeviceInfo& Device::GetDeviceInfo() const {
        return mDeviceInfo;
    }

    VkDevice Device::GetVkDevice() const {
        return mVkDevice;
    }

    uint32_t Device::GetGraphicsQueueFamily() const {
        return mQueueFamily;
    }

    VkQueue Device::GetQueue() const {
        return mQueue;
    }

    MapRequestTracker* Device::GetMapRequestTracker() const {
        return mMapRequestTracker.get();
    }

    FencedDeleter* Device::GetFencedDeleter() const {
        return mDeleter.get();
    }

    RenderPassCache* Device::GetRenderPassCache() const {
        return mRenderPassCache.get();
    }

    void Device::EnqueueDeferredDeallocation(BindGroupLayout* bindGroupLayout) {
        mBindGroupLayoutsPendingDeallocation.Enqueue(bindGroupLayout, GetPendingCommandSerial());
    }

    CommandRecordingContext* Device::GetPendingRecordingContext() {
        ASSERT(mRecordingContext.commandBuffer != VK_NULL_HANDLE);
        mRecordingContext.used = true;
        return &mRecordingContext;
    }

    MaybeError Device::SubmitPendingCommands() {
        if (!mRecordingContext.used) {
            return {};
        }

        DAWN_TRY(CheckVkSuccess(fn.EndCommandBuffer(mRecordingContext.commandBuffer),
                                "vkEndCommandBuffer"));

        std::vector<VkPipelineStageFlags> dstStageMasks(mRecordingContext.waitSemaphores.size(),
                                                        VK_PIPELINE_STAGE_ALL_COMMANDS_BIT);

        VkSubmitInfo submitInfo;
        submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
        submitInfo.pNext = nullptr;
        submitInfo.waitSemaphoreCount =
            static_cast<uint32_t>(mRecordingContext.waitSemaphores.size());
        submitInfo.pWaitSemaphores = AsVkArray(mRecordingContext.waitSemaphores.data());
        submitInfo.pWaitDstStageMask = dstStageMasks.data();
        submitInfo.commandBufferCount = 1;
        submitInfo.pCommandBuffers = &mRecordingContext.commandBuffer;
        submitInfo.signalSemaphoreCount =
            static_cast<uint32_t>(mRecordingContext.signalSemaphores.size());
        submitInfo.pSignalSemaphores = AsVkArray(mRecordingContext.signalSemaphores.data());

        VkFence fence = VK_NULL_HANDLE;
        DAWN_TRY_ASSIGN(fence, GetUnusedFence());
        DAWN_TRY(CheckVkSuccess(fn.QueueSubmit(mQueue, 1, &submitInfo, fence), "vkQueueSubmit"));

        // Enqueue the semaphores before incrementing the serial, so that they can be deleted as
        // soon as the current submission is finished.
        for (VkSemaphore semaphore : mRecordingContext.waitSemaphores) {
            mDeleter->DeleteWhenUnused(semaphore);
        }
        for (VkSemaphore semaphore : mRecordingContext.signalSemaphores) {
            mDeleter->DeleteWhenUnused(semaphore);
        }

        IncrementLastSubmittedCommandSerial();
        Serial lastSubmittedSerial = GetLastSubmittedCommandSerial();
        mFencesInFlight.emplace(fence, lastSubmittedSerial);

        CommandPoolAndBuffer submittedCommands = {mRecordingContext.commandPool,
                                                  mRecordingContext.commandBuffer};
        mCommandsInFlight.Enqueue(submittedCommands, lastSubmittedSerial);
        mRecordingContext = CommandRecordingContext();
        DAWN_TRY(PrepareRecordingContext());

        return {};
    }

    ResultOrError<VulkanDeviceKnobs> Device::CreateDevice(VkPhysicalDevice physicalDevice) {
        VulkanDeviceKnobs usedKnobs = {};

        float zero = 0.0f;
        std::vector<const char*> layersToRequest;
        std::vector<const char*> extensionsToRequest;
        std::vector<VkDeviceQueueCreateInfo> queuesToRequest;

        if (mDeviceInfo.debugMarker) {
            extensionsToRequest.push_back(kExtensionNameExtDebugMarker);
            usedKnobs.debugMarker = true;
        }
        if (mDeviceInfo.externalMemory) {
            extensionsToRequest.push_back(kExtensionNameKhrExternalMemory);
            usedKnobs.externalMemory = true;
        }
        if (mDeviceInfo.externalMemoryFD) {
            extensionsToRequest.push_back(kExtensionNameKhrExternalMemoryFD);
            usedKnobs.externalMemoryFD = true;
        }
        if (mDeviceInfo.externalMemoryDmaBuf) {
            extensionsToRequest.push_back(kExtensionNameExtExternalMemoryDmaBuf);
            usedKnobs.externalMemoryDmaBuf = true;
        }
        if (mDeviceInfo.imageDrmFormatModifier) {
            extensionsToRequest.push_back(kExtensionNameExtImageDrmFormatModifier);
            usedKnobs.imageDrmFormatModifier = true;
        }
        if (mDeviceInfo.externalMemoryZirconHandle) {
            extensionsToRequest.push_back(kExtensionNameFuchsiaExternalMemory);
            usedKnobs.externalMemoryZirconHandle = true;
        }
        if (mDeviceInfo.externalSemaphore) {
            extensionsToRequest.push_back(kExtensionNameKhrExternalSemaphore);
            usedKnobs.externalSemaphore = true;
        }
        if (mDeviceInfo.externalSemaphoreFD) {
            extensionsToRequest.push_back(kExtensionNameKhrExternalSemaphoreFD);
            usedKnobs.externalSemaphoreFD = true;
        }
        if (mDeviceInfo.externalSemaphoreZirconHandle) {
            extensionsToRequest.push_back(kExtensionNameFuchsiaExternalSemaphore);
            usedKnobs.externalSemaphoreZirconHandle = true;
        }
        if (mDeviceInfo.swapchain) {
            extensionsToRequest.push_back(kExtensionNameKhrSwapchain);
            usedKnobs.swapchain = true;
        }
        if (mDeviceInfo.maintenance1) {
            extensionsToRequest.push_back(kExtensionNameKhrMaintenance1);
            usedKnobs.maintenance1 = true;
        }

        // Always require independentBlend because it is a core Dawn feature
        usedKnobs.features.independentBlend = VK_TRUE;
        // Always require imageCubeArray because it is a core Dawn feature
        usedKnobs.features.imageCubeArray = VK_TRUE;
        // Always require fragmentStoresAndAtomics because it is required by end2end tests.
        usedKnobs.features.fragmentStoresAndAtomics = VK_TRUE;

        if (IsExtensionEnabled(Extension::TextureCompressionBC)) {
            ASSERT(ToBackend(GetAdapter())->GetDeviceInfo().features.textureCompressionBC ==
                   VK_TRUE);
            usedKnobs.features.textureCompressionBC = VK_TRUE;
        }

        // Find a universal queue family
        {
            // Note that GRAPHICS and COMPUTE imply TRANSFER so we don't need to check for it.
            constexpr uint32_t kUniversalFlags = VK_QUEUE_GRAPHICS_BIT | VK_QUEUE_COMPUTE_BIT;
            int universalQueueFamily = -1;
            for (unsigned int i = 0; i < mDeviceInfo.queueFamilies.size(); ++i) {
                if ((mDeviceInfo.queueFamilies[i].queueFlags & kUniversalFlags) ==
                    kUniversalFlags) {
                    universalQueueFamily = i;
                    break;
                }
            }

            if (universalQueueFamily == -1) {
                return DAWN_INTERNAL_ERROR("No universal queue family");
            }
            mQueueFamily = static_cast<uint32_t>(universalQueueFamily);
        }

        // Choose to create a single universal queue
        {
            VkDeviceQueueCreateInfo queueCreateInfo;
            queueCreateInfo.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
            queueCreateInfo.pNext = nullptr;
            queueCreateInfo.flags = 0;
            queueCreateInfo.queueFamilyIndex = static_cast<uint32_t>(mQueueFamily);
            queueCreateInfo.queueCount = 1;
            queueCreateInfo.pQueuePriorities = &zero;

            queuesToRequest.push_back(queueCreateInfo);
        }

        VkDeviceCreateInfo createInfo;
        createInfo.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
        createInfo.pNext = nullptr;
        createInfo.flags = 0;
        createInfo.queueCreateInfoCount = static_cast<uint32_t>(queuesToRequest.size());
        createInfo.pQueueCreateInfos = queuesToRequest.data();
        createInfo.enabledLayerCount = static_cast<uint32_t>(layersToRequest.size());
        createInfo.ppEnabledLayerNames = layersToRequest.data();
        createInfo.enabledExtensionCount = static_cast<uint32_t>(extensionsToRequest.size());
        createInfo.ppEnabledExtensionNames = extensionsToRequest.data();
        createInfo.pEnabledFeatures = &usedKnobs.features;

        DAWN_TRY(CheckVkSuccess(fn.CreateDevice(physicalDevice, &createInfo, nullptr, &mVkDevice),
                                "vkCreateDevice"));

        return usedKnobs;
    }

    void Device::GatherQueueFromDevice() {
        fn.GetDeviceQueue(mVkDevice, mQueueFamily, 0, &mQueue);
    }

    void Device::InitTogglesFromDriver() {
        // TODO(jiawei.shao@intel.com): tighten this workaround when this issue is fixed in both
        // Vulkan SPEC and drivers.
        SetToggle(Toggle::UseTemporaryBufferInCompressedTextureToTextureCopy, true);

        // By default try to use D32S8 for Depth24PlusStencil8
        SetToggle(Toggle::VulkanUseD32S8, true);
    }

    void Device::ApplyDepth24PlusS8Toggle() {
        VkPhysicalDevice physicalDevice = ToBackend(GetAdapter())->GetPhysicalDevice();

        bool supportsD32s8 = false;
        {
            VkFormatProperties properties;
            fn.GetPhysicalDeviceFormatProperties(physicalDevice, VK_FORMAT_D32_SFLOAT_S8_UINT,
                                                 &properties);
            supportsD32s8 =
                properties.optimalTilingFeatures & VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT;
        }

        bool supportsD24s8 = false;
        {
            VkFormatProperties properties;
            fn.GetPhysicalDeviceFormatProperties(physicalDevice, VK_FORMAT_D24_UNORM_S8_UINT,
                                                 &properties);
            supportsD24s8 =
                properties.optimalTilingFeatures & VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT;
        }

        ASSERT(supportsD32s8 || supportsD24s8);

        if (!supportsD24s8) {
            ForceSetToggle(Toggle::VulkanUseD32S8, true);
        }
        if (!supportsD32s8) {
            ForceSetToggle(Toggle::VulkanUseD32S8, false);
        }
    }

    VulkanFunctions* Device::GetMutableFunctions() {
        return const_cast<VulkanFunctions*>(&fn);
    }

    ResultOrError<VkFence> Device::GetUnusedFence() {
        if (!mUnusedFences.empty()) {
            VkFence fence = mUnusedFences.back();
            DAWN_TRY(CheckVkSuccess(fn.ResetFences(mVkDevice, 1, &*fence), "vkResetFences"));

            mUnusedFences.pop_back();
            return fence;
        }

        VkFenceCreateInfo createInfo;
        createInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
        createInfo.pNext = nullptr;
        createInfo.flags = 0;

        VkFence fence = VK_NULL_HANDLE;
        DAWN_TRY(CheckVkSuccess(fn.CreateFence(mVkDevice, &createInfo, nullptr, &*fence),
                                "vkCreateFence"));

        return fence;
    }

    Serial Device::CheckAndUpdateCompletedSerials() {
        Serial fenceSerial = 0;
        while (!mFencesInFlight.empty()) {
            VkFence fence = mFencesInFlight.front().first;
            Serial tentativeSerial = mFencesInFlight.front().second;
            VkResult result = VkResult::WrapUnsafe(
                INJECT_ERROR_OR_RUN(fn.GetFenceStatus(mVkDevice, fence), VK_ERROR_DEVICE_LOST));
            // TODO: Handle DeviceLost error.
            ASSERT(result == VK_SUCCESS || result == VK_NOT_READY);

            // Fence are added in order, so we can stop searching as soon
            // as we see one that's not ready.
            if (result == VK_NOT_READY) {
                return fenceSerial;
            }
            // Update fenceSerial since fence is ready.
            fenceSerial = tentativeSerial;

            mUnusedFences.push_back(fence);

            ASSERT(fenceSerial > GetCompletedCommandSerial());
            mFencesInFlight.pop();
        }
        return fenceSerial;
    }

    MaybeError Device::PrepareRecordingContext() {
        ASSERT(!mRecordingContext.used);
        ASSERT(mRecordingContext.commandBuffer == VK_NULL_HANDLE);
        ASSERT(mRecordingContext.commandPool == VK_NULL_HANDLE);

        // First try to recycle unused command pools.
        if (!mUnusedCommands.empty()) {
            CommandPoolAndBuffer commands = mUnusedCommands.back();
            mUnusedCommands.pop_back();
            DAWN_TRY(CheckVkSuccess(fn.ResetCommandPool(mVkDevice, commands.pool, 0),
                                    "vkResetCommandPool"));

            mRecordingContext.commandBuffer = commands.commandBuffer;
            mRecordingContext.commandPool = commands.pool;
        } else {
            // Create a new command pool for our commands and allocate the command buffer.
            VkCommandPoolCreateInfo createInfo;
            createInfo.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
            createInfo.pNext = nullptr;
            createInfo.flags = VK_COMMAND_POOL_CREATE_TRANSIENT_BIT;
            createInfo.queueFamilyIndex = mQueueFamily;

            DAWN_TRY(CheckVkSuccess(fn.CreateCommandPool(mVkDevice, &createInfo, nullptr,
                                                         &*mRecordingContext.commandPool),
                                    "vkCreateCommandPool"));

            VkCommandBufferAllocateInfo allocateInfo;
            allocateInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
            allocateInfo.pNext = nullptr;
            allocateInfo.commandPool = mRecordingContext.commandPool;
            allocateInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
            allocateInfo.commandBufferCount = 1;

            DAWN_TRY(CheckVkSuccess(fn.AllocateCommandBuffers(mVkDevice, &allocateInfo,
                                                              &mRecordingContext.commandBuffer),
                                    "vkAllocateCommandBuffers"));
        }

        // Start the recording of commands in the command buffer.
        VkCommandBufferBeginInfo beginInfo;
        beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
        beginInfo.pNext = nullptr;
        beginInfo.flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
        beginInfo.pInheritanceInfo = nullptr;

        return CheckVkSuccess(fn.BeginCommandBuffer(mRecordingContext.commandBuffer, &beginInfo),
                              "vkBeginCommandBuffer");
    }

    void Device::RecycleCompletedCommands() {
        for (auto& commands : mCommandsInFlight.IterateUpTo(GetCompletedCommandSerial())) {
            mUnusedCommands.push_back(commands);
        }
        mCommandsInFlight.ClearUpTo(GetCompletedCommandSerial());
    }

    ResultOrError<std::unique_ptr<StagingBufferBase>> Device::CreateStagingBuffer(size_t size) {
        std::unique_ptr<StagingBufferBase> stagingBuffer =
            std::make_unique<StagingBuffer>(size, this);
        DAWN_TRY(stagingBuffer->Initialize());
        return std::move(stagingBuffer);
    }

    MaybeError Device::CopyFromStagingToBuffer(StagingBufferBase* source,
                                               uint64_t sourceOffset,
                                               BufferBase* destination,
                                               uint64_t destinationOffset,
                                               uint64_t size) {
        // It is a validation error to do a 0-sized copy in Vulkan skip it since it is a noop.
        if (size == 0) {
            return {};
        }

        CommandRecordingContext* recordingContext = GetPendingRecordingContext();

        // Insert memory barrier to ensure host write operations are made visible before
        // copying from the staging buffer. However, this barrier can be removed (see note below).
        //
        // Note: Depending on the spec understanding, an explicit barrier may not be required when
        // used with HOST_COHERENT as vkQueueSubmit does an implicit barrier between host and
        // device. See "Availability, Visibility, and Domain Operations" in Vulkan spec for details.

        // Insert pipeline barrier to ensure correct ordering with previous memory operations on the
        // buffer.
        ToBackend(destination)->TransitionUsageNow(recordingContext, wgpu::BufferUsage::CopyDst);

        VkBufferCopy copy;
        copy.srcOffset = sourceOffset;
        copy.dstOffset = destinationOffset;
        copy.size = size;

        this->fn.CmdCopyBuffer(recordingContext->commandBuffer,
                               ToBackend(source)->GetBufferHandle(),
                               ToBackend(destination)->GetHandle(), 1, &copy);

        return {};
    }

    MaybeError Device::ImportExternalImage(const ExternalImageDescriptor* descriptor,
                                           ExternalMemoryHandle memoryHandle,
                                           VkImage image,
                                           const std::vector<ExternalSemaphoreHandle>& waitHandles,
                                           VkSemaphore* outSignalSemaphore,
                                           VkDeviceMemory* outAllocation,
                                           std::vector<VkSemaphore>* outWaitSemaphores) {
        const TextureDescriptor* textureDescriptor =
            reinterpret_cast<const TextureDescriptor*>(descriptor->cTextureDescriptor);

        // Check services support this combination of handle type / image info
        if (!mExternalSemaphoreService->Supported()) {
            return DAWN_VALIDATION_ERROR("External semaphore usage not supported");
        }
        if (!mExternalMemoryService->SupportsImportMemory(
                VulkanImageFormat(this, textureDescriptor->format), VK_IMAGE_TYPE_2D,
                VK_IMAGE_TILING_OPTIMAL,
                VulkanImageUsage(textureDescriptor->usage,
                                 GetValidInternalFormat(textureDescriptor->format)),
                VK_IMAGE_CREATE_ALIAS_BIT_KHR)) {
            return DAWN_VALIDATION_ERROR("External memory usage not supported");
        }

        // Create an external semaphore to signal when the texture is done being used
        DAWN_TRY_ASSIGN(*outSignalSemaphore,
                        mExternalSemaphoreService->CreateExportableSemaphore());

        // Import the external image's memory
        external_memory::MemoryImportParams importParams;
        DAWN_TRY_ASSIGN(importParams,
                        mExternalMemoryService->GetMemoryImportParams(descriptor, image));
        DAWN_TRY_ASSIGN(*outAllocation,
                        mExternalMemoryService->ImportMemory(memoryHandle, importParams, image));

        // Import semaphores we have to wait on before using the texture
        for (const ExternalSemaphoreHandle& handle : waitHandles) {
            VkSemaphore semaphore = VK_NULL_HANDLE;
            DAWN_TRY_ASSIGN(semaphore, mExternalSemaphoreService->ImportSemaphore(handle));
            outWaitSemaphores->push_back(semaphore);
        }

        return {};
    }

    MaybeError Device::SignalAndExportExternalTexture(Texture* texture,
                                                      ExternalSemaphoreHandle* outHandle) {
        DAWN_TRY(ValidateObject(texture));

        VkSemaphore outSignalSemaphore;
        DAWN_TRY(texture->SignalAndDestroy(&outSignalSemaphore));

        // This has to happen right after SignalAndDestroy, since the semaphore will be
        // deleted when the fenced deleter runs after the queue submission
        DAWN_TRY_ASSIGN(*outHandle, mExternalSemaphoreService->ExportSemaphore(outSignalSemaphore));

        return {};
    }

    TextureBase* Device::CreateTextureWrappingVulkanImage(
        const ExternalImageDescriptor* descriptor,
        ExternalMemoryHandle memoryHandle,
        const std::vector<ExternalSemaphoreHandle>& waitHandles) {
        const TextureDescriptor* textureDescriptor =
            reinterpret_cast<const TextureDescriptor*>(descriptor->cTextureDescriptor);

        // Initial validation
        if (ConsumedError(ValidateTextureDescriptor(this, textureDescriptor))) {
            return nullptr;
        }
        if (ConsumedError(ValidateVulkanImageCanBeWrapped(this, textureDescriptor))) {
            return nullptr;
        }

        VkSemaphore signalSemaphore = VK_NULL_HANDLE;
        VkDeviceMemory allocation = VK_NULL_HANDLE;
        std::vector<VkSemaphore> waitSemaphores;
        waitSemaphores.reserve(waitHandles.size());

        // Cleanup in case of a failure, the image creation doesn't acquire the external objects
        // if a failure happems.
        Texture* result = nullptr;
        // TODO(crbug.com/1026480): Consolidate this into a single CreateFromExternal call.
        if (ConsumedError(Texture::CreateFromExternal(this, descriptor, textureDescriptor,
                                                      mExternalMemoryService.get()),
                          &result) ||
            ConsumedError(ImportExternalImage(descriptor, memoryHandle, result->GetHandle(),
                                              waitHandles, &signalSemaphore, &allocation,
                                              &waitSemaphores)) ||
            ConsumedError(result->BindExternalMemory(descriptor, signalSemaphore, allocation,
                                                     waitSemaphores))) {
            // Delete the Texture if it was created
            if (result != nullptr) {
                result->Release();
            }

            // Clear the signal semaphore
            fn.DestroySemaphore(GetVkDevice(), signalSemaphore, nullptr);

            // Clear image memory
            fn.FreeMemory(GetVkDevice(), allocation, nullptr);

            // Clear any wait semaphores we were able to import
            for (VkSemaphore semaphore : waitSemaphores) {
                fn.DestroySemaphore(GetVkDevice(), semaphore, nullptr);
            }
            return nullptr;
        }

        return result;
    }

    ResultOrError<ResourceMemoryAllocation> Device::AllocateMemory(
        VkMemoryRequirements requirements,
        bool mappable) {
        return mResourceMemoryAllocator->Allocate(requirements, mappable);
    }

    void Device::DeallocateMemory(ResourceMemoryAllocation* allocation) {
        mResourceMemoryAllocator->Deallocate(allocation);
    }

    int Device::FindBestMemoryTypeIndex(VkMemoryRequirements requirements, bool mappable) {
        return mResourceMemoryAllocator->FindBestTypeIndex(requirements, mappable);
    }

    ResourceMemoryAllocator* Device::GetResourceMemoryAllocatorForTesting() const {
        return mResourceMemoryAllocator.get();
    }

    MaybeError Device::WaitForIdleForDestruction() {
        VkResult waitIdleResult = VkResult::WrapUnsafe(fn.QueueWaitIdle(mQueue));
        // Ignore the result of QueueWaitIdle: it can return OOM which we can't really do anything
        // about, Device lost, which means workloads running on the GPU are no longer accessible
        // (so they are as good as waited on) or success.
        DAWN_UNUSED(waitIdleResult);

        // Make sure all fences are complete by explicitly waiting on them all
        while (!mFencesInFlight.empty()) {
            VkFence fence = mFencesInFlight.front().first;
            Serial fenceSerial = mFencesInFlight.front().second;
            ASSERT(fenceSerial > GetCompletedCommandSerial());

            VkResult result = VkResult::WrapUnsafe(VK_TIMEOUT);
            do {
                result = VkResult::WrapUnsafe(
                    INJECT_ERROR_OR_RUN(fn.WaitForFences(mVkDevice, 1, &*fence, true, UINT64_MAX),
                                        VK_ERROR_DEVICE_LOST));
            } while (result == VK_TIMEOUT);

            // TODO: Handle errors
            ASSERT(result == VK_SUCCESS);
            fn.DestroyFence(mVkDevice, fence, nullptr);

            mFencesInFlight.pop();
        }

        // Force all operations to look as if they were completed
        AssumeCommandsComplete();
        return {};
    }

    void Device::ShutDownImpl() {
        ASSERT(GetState() == State::Disconnected);

        // We failed during initialization so early that we don't even have a VkDevice. There is
        // nothing to do.
        if (mVkDevice == VK_NULL_HANDLE) {
            return;
        }

        // The deleter is the second thing we initialize. If it is not present, it means that
        // only the VkDevice was created and nothing else. Destroy the device and do nothing else
        // because the function pointers might not have been loaded (and there is nothing to
        // destroy anyway).
        if (mDeleter == nullptr) {
            fn.DestroyDevice(mVkDevice, nullptr);
            mVkDevice = VK_NULL_HANDLE;
            return;
        }

        // Enough of the Device's initialization happened that we can now do regular robust
        // deinitialization.

        // Immediately tag the recording context as unused so we don't try to submit it in Tick.
        mRecordingContext.used = false;
        fn.DestroyCommandPool(mVkDevice, mRecordingContext.commandPool, nullptr);

        for (VkSemaphore semaphore : mRecordingContext.waitSemaphores) {
            fn.DestroySemaphore(mVkDevice, semaphore, nullptr);
        }
        mRecordingContext.waitSemaphores.clear();

        for (VkSemaphore semaphore : mRecordingContext.signalSemaphores) {
            fn.DestroySemaphore(mVkDevice, semaphore, nullptr);
        }
        mRecordingContext.signalSemaphores.clear();

        // Some operations might have been started since the last submit and waiting
        // on a serial that doesn't have a corresponding fence enqueued. Force all
        // operations to look as if they were completed (because they were).
        AssumeCommandsComplete();

        // Assert that errors are device loss so that we can continue with destruction
        AssertAndIgnoreDeviceLossError(TickImpl());

        ASSERT(mCommandsInFlight.Empty());
        for (const CommandPoolAndBuffer& commands : mUnusedCommands) {
            fn.DestroyCommandPool(mVkDevice, commands.pool, nullptr);
        }
        mUnusedCommands.clear();

        for (VkFence fence : mUnusedFences) {
            fn.DestroyFence(mVkDevice, fence, nullptr);
        }
        mUnusedFences.clear();

        // Releasing the uploader enqueues buffers to be released.
        // Call Tick() again to clear them before releasing the deleter.
        mDeleter->Tick(GetCompletedCommandSerial());

        mMapRequestTracker = nullptr;

        // The VkRenderPasses in the cache can be destroyed immediately since all commands referring
        // to them are guaranteed to be finished executing.
        mRenderPassCache = nullptr;

        // We need handle deleting all child objects by calling Tick() again with a large serial to
        // force all operations to look as if they were completed, and delete all objects before
        // destroying the Deleter and vkDevice.
        ASSERT(mDeleter != nullptr);
        mDeleter->Tick(std::numeric_limits<Serial>::max());
        mDeleter = nullptr;

        // VkQueues are destroyed when the VkDevice is destroyed
        // The VkDevice is needed to destroy child objects, so it must be destroyed last after all
        // child objects have been deleted.
        ASSERT(mVkDevice != VK_NULL_HANDLE);
        fn.DestroyDevice(mVkDevice, nullptr);
        mVkDevice = VK_NULL_HANDLE;
    }

}}  // namespace dawn_native::vulkan