// Copyright 2019 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/d3d12/ResourceAllocatorManagerD3D12.h"

#include <limits>
#include <utility>

#include "dawn/native/d3d12/D3D12Error.h"
#include "dawn/native/d3d12/DeviceD3D12.h"
#include "dawn/native/d3d12/HeapAllocatorD3D12.h"
#include "dawn/native/d3d12/HeapD3D12.h"
#include "dawn/native/d3d12/ResidencyManagerD3D12.h"
#include "dawn/native/d3d12/UtilsD3D12.h"

namespace dawn::native::d3d12 {
namespace {
MemorySegment GetMemorySegment(Device* device, D3D12_HEAP_TYPE heapType) {
    if (device->GetDeviceInfo().isUMA) {
        return MemorySegment::Local;
    }

    D3D12_HEAP_PROPERTIES heapProperties =
        device->GetD3D12Device()->GetCustomHeapProperties(0, heapType);

    if (heapProperties.MemoryPoolPreference == D3D12_MEMORY_POOL_L1) {
        return MemorySegment::Local;
    }

    return MemorySegment::NonLocal;
}

D3D12_HEAP_TYPE GetD3D12HeapType(ResourceHeapKind resourceHeapKind) {
    switch (resourceHeapKind) {
        case Readback_OnlyBuffers:
        case Readback_AllBuffersAndTextures:
            return D3D12_HEAP_TYPE_READBACK;
        case Default_AllBuffersAndTextures:
        case Default_OnlyBuffers:
        case Default_OnlyNonRenderableOrDepthTextures:
        case Default_OnlyRenderableOrDepthTextures:
            return D3D12_HEAP_TYPE_DEFAULT;
        case Upload_OnlyBuffers:
        case Upload_AllBuffersAndTextures:
            return D3D12_HEAP_TYPE_UPLOAD;
        case EnumCount:
            UNREACHABLE();
    }
}

D3D12_HEAP_FLAGS GetD3D12HeapFlags(ResourceHeapKind resourceHeapKind) {
    switch (resourceHeapKind) {
        case Default_AllBuffersAndTextures:
        case Readback_AllBuffersAndTextures:
        case Upload_AllBuffersAndTextures:
            return D3D12_HEAP_FLAG_ALLOW_ALL_BUFFERS_AND_TEXTURES;
        case Default_OnlyBuffers:
        case Readback_OnlyBuffers:
        case Upload_OnlyBuffers:
            return D3D12_HEAP_FLAG_ALLOW_ONLY_BUFFERS;
        case Default_OnlyNonRenderableOrDepthTextures:
            return D3D12_HEAP_FLAG_ALLOW_ONLY_NON_RT_DS_TEXTURES;
        case Default_OnlyRenderableOrDepthTextures:
            return D3D12_HEAP_FLAG_ALLOW_ONLY_RT_DS_TEXTURES;
        case EnumCount:
            UNREACHABLE();
    }
}

ResourceHeapKind GetResourceHeapKind(D3D12_RESOURCE_DIMENSION dimension,
                                     D3D12_HEAP_TYPE heapType,
                                     D3D12_RESOURCE_FLAGS flags,
                                     uint32_t resourceHeapTier) {
    if (resourceHeapTier >= 2) {
        switch (heapType) {
            case D3D12_HEAP_TYPE_UPLOAD:
                return Upload_AllBuffersAndTextures;
            case D3D12_HEAP_TYPE_DEFAULT:
                return Default_AllBuffersAndTextures;
            case D3D12_HEAP_TYPE_READBACK:
                return Readback_AllBuffersAndTextures;
            default:
                UNREACHABLE();
        }
    }

    switch (dimension) {
        case D3D12_RESOURCE_DIMENSION_BUFFER: {
            switch (heapType) {
                case D3D12_HEAP_TYPE_UPLOAD:
                    return Upload_OnlyBuffers;
                case D3D12_HEAP_TYPE_DEFAULT:
                    return Default_OnlyBuffers;
                case D3D12_HEAP_TYPE_READBACK:
                    return Readback_OnlyBuffers;
                default:
                    UNREACHABLE();
            }
            break;
        }
        case D3D12_RESOURCE_DIMENSION_TEXTURE1D:
        case D3D12_RESOURCE_DIMENSION_TEXTURE2D:
        case D3D12_RESOURCE_DIMENSION_TEXTURE3D: {
            switch (heapType) {
                case D3D12_HEAP_TYPE_DEFAULT: {
                    if ((flags & D3D12_RESOURCE_FLAG_ALLOW_DEPTH_STENCIL) ||
                        (flags & D3D12_RESOURCE_FLAG_ALLOW_RENDER_TARGET)) {
                        return Default_OnlyRenderableOrDepthTextures;
                    }
                    return Default_OnlyNonRenderableOrDepthTextures;
                }

                default:
                    UNREACHABLE();
            }
            break;
        }
        default:
            UNREACHABLE();
    }
}

uint64_t GetResourcePlacementAlignment(ResourceHeapKind resourceHeapKind,
                                       uint32_t sampleCount,
                                       uint64_t requestedAlignment) {
    switch (resourceHeapKind) {
        // Small resources can take advantage of smaller alignments. For example,
        // if the most detailed mip can fit under 64KB, 4KB alignments can be used.
        // Must be non-depth or without render-target to use small resource alignment.
        // This also applies to MSAA textures (4MB => 64KB).
        //
        // Note: Only known to be used for small textures; however, MSDN suggests
        // it could be extended for more cases. If so, this could default to always
        // attempt small resource placement.
        // https://docs.microsoft.com/en-us/windows/win32/api/d3d12/ns-d3d12-d3d12_resource_desc
        case Default_OnlyNonRenderableOrDepthTextures:
            return (sampleCount > 1) ? D3D12_SMALL_MSAA_RESOURCE_PLACEMENT_ALIGNMENT
                                     : D3D12_SMALL_RESOURCE_PLACEMENT_ALIGNMENT;
        default:
            return requestedAlignment;
    }
}

bool IsClearValueOptimizable(const D3D12_RESOURCE_DESC& resourceDescriptor) {
    // Optimized clear color cannot be set on buffers, non-render-target/depth-stencil
    // textures, or typeless resources
    // https://docs.microsoft.com/en-us/windows/win32/api/d3d12/nf-d3d12-id3d12device-createcommittedresource
    // https://docs.microsoft.com/en-us/windows/win32/api/d3d12/nf-d3d12-id3d12device-createplacedresource
    return !IsTypeless(resourceDescriptor.Format) &&
           resourceDescriptor.Dimension != D3D12_RESOURCE_DIMENSION_BUFFER &&
           (resourceDescriptor.Flags & (D3D12_RESOURCE_FLAG_ALLOW_RENDER_TARGET |
                                        D3D12_RESOURCE_FLAG_ALLOW_DEPTH_STENCIL)) != 0;
}

}  // namespace

ResourceAllocatorManager::ResourceAllocatorManager(Device* device) : mDevice(device) {
    mResourceHeapTier = (mDevice->IsToggleEnabled(Toggle::UseD3D12ResourceHeapTier2))
                            ? mDevice->GetDeviceInfo().resourceHeapTier
                            : 1;

    for (uint32_t i = 0; i < ResourceHeapKind::EnumCount; i++) {
        const ResourceHeapKind resourceHeapKind = static_cast<ResourceHeapKind>(i);
        mHeapAllocators[i] = std::make_unique<HeapAllocator>(
            mDevice, GetD3D12HeapType(resourceHeapKind), GetD3D12HeapFlags(resourceHeapKind),
            GetMemorySegment(device, GetD3D12HeapType(resourceHeapKind)));
        mPooledHeapAllocators[i] =
            std::make_unique<PooledResourceMemoryAllocator>(mHeapAllocators[i].get());
        mSubAllocatedResourceAllocators[i] = std::make_unique<BuddyMemoryAllocator>(
            kMaxHeapSize, kMinHeapSize, mPooledHeapAllocators[i].get());
    }
}

ResultOrError<ResourceHeapAllocation> ResourceAllocatorManager::AllocateMemory(
    D3D12_HEAP_TYPE heapType,
    const D3D12_RESOURCE_DESC& resourceDescriptor,
    D3D12_RESOURCE_STATES initialUsage) {
    // In order to suppress a warning in the D3D12 debug layer, we need to specify an
    // optimized clear value. As there are no negative consequences when picking a mismatched
    // clear value, we use zero as the optimized clear value. This also enables fast clears on
    // some architectures.
    D3D12_CLEAR_VALUE zero{};
    D3D12_CLEAR_VALUE* optimizedClearValue = nullptr;
    if (IsClearValueOptimizable(resourceDescriptor)) {
        zero.Format = resourceDescriptor.Format;
        optimizedClearValue = &zero;
    }

    // TODO(crbug.com/dawn/849): Conditionally disable sub-allocation.
    // For very large resources, there is no benefit to suballocate.
    // For very small resources, it is inefficent to suballocate given the min. heap
    // size could be much larger then the resource allocation.
    // Attempt to satisfy the request using sub-allocation (placed resource in a heap).
    if (!mDevice->IsToggleEnabled(Toggle::DisableResourceSuballocation)) {
        ResourceHeapAllocation subAllocation;
        DAWN_TRY_ASSIGN(subAllocation, CreatePlacedResource(heapType, resourceDescriptor,
                                                            optimizedClearValue, initialUsage));
        if (subAllocation.GetInfo().mMethod != AllocationMethod::kInvalid) {
            return std::move(subAllocation);
        }
    }

    // If sub-allocation fails, fall-back to direct allocation (committed resource).
    ResourceHeapAllocation directAllocation;
    DAWN_TRY_ASSIGN(directAllocation, CreateCommittedResource(heapType, resourceDescriptor,
                                                              optimizedClearValue, initialUsage));
    if (directAllocation.GetInfo().mMethod != AllocationMethod::kInvalid) {
        return std::move(directAllocation);
    }

    // If direct allocation fails, the system is probably out of memory.
    return DAWN_OUT_OF_MEMORY_ERROR("Allocation failed");
}

void ResourceAllocatorManager::Tick(ExecutionSerial completedSerial) {
    for (ResourceHeapAllocation& allocation : mAllocationsToDelete.IterateUpTo(completedSerial)) {
        if (allocation.GetInfo().mMethod == AllocationMethod::kSubAllocated) {
            FreeMemory(allocation);
        }
    }
    mAllocationsToDelete.ClearUpTo(completedSerial);
    mHeapsToDelete.ClearUpTo(completedSerial);
}

void ResourceAllocatorManager::DeallocateMemory(ResourceHeapAllocation& allocation) {
    if (allocation.GetInfo().mMethod == AllocationMethod::kInvalid) {
        return;
    }

    mAllocationsToDelete.Enqueue(allocation, mDevice->GetPendingCommandSerial());

    // Directly allocated ResourceHeapAllocations are created with a heap object that must be
    // manually deleted upon deallocation. See ResourceAllocatorManager::CreateCommittedResource
    // for more information. Acquire this heap as a unique_ptr and add it to the queue of heaps
    // to delete. It cannot be deleted immediately because it may be in use by in-flight or
    // pending commands.
    if (allocation.GetInfo().mMethod == AllocationMethod::kDirect) {
        mHeapsToDelete.Enqueue(std::unique_ptr<ResourceHeapBase>(allocation.GetResourceHeap()),
                               mDevice->GetPendingCommandSerial());
    }

    // Invalidate the allocation immediately in case one accidentally
    // calls DeallocateMemory again using the same allocation.
    allocation.Invalidate();

    ASSERT(allocation.GetD3D12Resource() == nullptr);
}

void ResourceAllocatorManager::FreeMemory(ResourceHeapAllocation& allocation) {
    ASSERT(allocation.GetInfo().mMethod == AllocationMethod::kSubAllocated);

    D3D12_HEAP_PROPERTIES heapProp;
    allocation.GetD3D12Resource()->GetHeapProperties(&heapProp, nullptr);

    const D3D12_RESOURCE_DESC resourceDescriptor = allocation.GetD3D12Resource()->GetDesc();

    const size_t resourceHeapKindIndex = GetResourceHeapKind(
        resourceDescriptor.Dimension, heapProp.Type, resourceDescriptor.Flags, mResourceHeapTier);

    mSubAllocatedResourceAllocators[resourceHeapKindIndex]->Deallocate(allocation);
}

ResultOrError<ResourceHeapAllocation> ResourceAllocatorManager::CreatePlacedResource(
    D3D12_HEAP_TYPE heapType,
    const D3D12_RESOURCE_DESC& requestedResourceDescriptor,
    const D3D12_CLEAR_VALUE* optimizedClearValue,
    D3D12_RESOURCE_STATES initialUsage) {
    const ResourceHeapKind resourceHeapKind =
        GetResourceHeapKind(requestedResourceDescriptor.Dimension, heapType,
                            requestedResourceDescriptor.Flags, mResourceHeapTier);

    D3D12_RESOURCE_DESC resourceDescriptor = requestedResourceDescriptor;
    resourceDescriptor.Alignment = GetResourcePlacementAlignment(
        resourceHeapKind, requestedResourceDescriptor.SampleDesc.Count,
        requestedResourceDescriptor.Alignment);

    // TODO(bryan.bernhart): Figure out how to compute the alignment without calling this
    // twice.
    D3D12_RESOURCE_ALLOCATION_INFO resourceInfo =
        mDevice->GetD3D12Device()->GetResourceAllocationInfo(0, 1, &resourceDescriptor);

    // If the requested resource alignment was rejected, let D3D tell us what the
    // required alignment is for this resource.
    if (resourceDescriptor.Alignment != 0 &&
        resourceDescriptor.Alignment != resourceInfo.Alignment) {
        resourceDescriptor.Alignment = 0;
        resourceInfo =
            mDevice->GetD3D12Device()->GetResourceAllocationInfo(0, 1, &resourceDescriptor);
    }

    // If d3d tells us the resource size is invalid, treat the error as OOM.
    // Otherwise, creating the resource could cause a device loss (too large).
    // This is because NextPowerOfTwo(UINT64_MAX) overflows and proceeds to
    // incorrectly allocate a mismatched size.
    if (resourceInfo.SizeInBytes == 0 ||
        resourceInfo.SizeInBytes == std::numeric_limits<uint64_t>::max()) {
        return DAWN_OUT_OF_MEMORY_ERROR(absl::StrFormat(
            "Resource allocation size (%u) was invalid.", resourceInfo.SizeInBytes));
    }

    BuddyMemoryAllocator* allocator =
        mSubAllocatedResourceAllocators[static_cast<size_t>(resourceHeapKind)].get();

    ResourceMemoryAllocation allocation;
    DAWN_TRY_ASSIGN(allocation,
                    allocator->Allocate(resourceInfo.SizeInBytes, resourceInfo.Alignment));
    if (allocation.GetInfo().mMethod == AllocationMethod::kInvalid) {
        return ResourceHeapAllocation{};  // invalid
    }

    Heap* heap = ToBackend(allocation.GetResourceHeap());

    // Before calling CreatePlacedResource, we must ensure the target heap is resident.
    // CreatePlacedResource will fail if it is not.
    DAWN_TRY(mDevice->GetResidencyManager()->LockAllocation(heap));

    // With placed resources, a single heap can be reused.
    // The resource placed at an offset is only reclaimed
    // upon Tick or after the last command list using the resource has completed
    // on the GPU. This means the same physical memory is not reused
    // within the same command-list and does not require additional synchronization (aliasing
    // barrier).
    // https://docs.microsoft.com/en-us/windows/win32/api/d3d12/nf-d3d12-id3d12device-createplacedresource
    ComPtr<ID3D12Resource> placedResource;
    DAWN_TRY(CheckOutOfMemoryHRESULT(
        mDevice->GetD3D12Device()->CreatePlacedResource(
            heap->GetD3D12Heap(), allocation.GetOffset(), &resourceDescriptor, initialUsage,
            optimizedClearValue, IID_PPV_ARGS(&placedResource)),
        "ID3D12Device::CreatePlacedResource"));

    // After CreatePlacedResource has finished, the heap can be unlocked from residency. This
    // will insert it into the residency LRU.
    mDevice->GetResidencyManager()->UnlockAllocation(heap);

    return ResourceHeapAllocation{allocation.GetInfo(), allocation.GetOffset(),
                                  std::move(placedResource), heap};
}

ResultOrError<ResourceHeapAllocation> ResourceAllocatorManager::CreateCommittedResource(
    D3D12_HEAP_TYPE heapType,
    const D3D12_RESOURCE_DESC& resourceDescriptor,
    const D3D12_CLEAR_VALUE* optimizedClearValue,
    D3D12_RESOURCE_STATES initialUsage) {
    D3D12_HEAP_PROPERTIES heapProperties;
    heapProperties.Type = heapType;
    heapProperties.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
    heapProperties.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
    heapProperties.CreationNodeMask = 0;
    heapProperties.VisibleNodeMask = 0;

    // If d3d tells us the resource size is invalid, treat the error as OOM.
    // Otherwise, creating the resource could cause a device loss (too large).
    // This is because NextPowerOfTwo(UINT64_MAX) overflows and proceeds to
    // incorrectly allocate a mismatched size.
    D3D12_RESOURCE_ALLOCATION_INFO resourceInfo =
        mDevice->GetD3D12Device()->GetResourceAllocationInfo(0, 1, &resourceDescriptor);
    if (resourceInfo.SizeInBytes == 0 ||
        resourceInfo.SizeInBytes == std::numeric_limits<uint64_t>::max()) {
        return DAWN_OUT_OF_MEMORY_ERROR("Resource allocation size was invalid.");
    }

    if (resourceInfo.SizeInBytes > kMaxHeapSize) {
        return ResourceHeapAllocation{};  // Invalid
    }

    // CreateCommittedResource will implicitly make the created resource resident. We must
    // ensure enough free memory exists before allocating to avoid an out-of-memory error when
    // overcommitted.
    DAWN_TRY(mDevice->GetResidencyManager()->EnsureCanAllocate(
        resourceInfo.SizeInBytes, GetMemorySegment(mDevice, heapType)));

    // Note: Heap flags are inferred by the resource descriptor and do not need to be explicitly
    // provided to CreateCommittedResource.
    ComPtr<ID3D12Resource> committedResource;
    DAWN_TRY(CheckOutOfMemoryHRESULT(
        mDevice->GetD3D12Device()->CreateCommittedResource(
            &heapProperties, D3D12_HEAP_FLAG_NONE, &resourceDescriptor, initialUsage,
            optimizedClearValue, IID_PPV_ARGS(&committedResource)),
        "ID3D12Device::CreateCommittedResource"));

    // When using CreateCommittedResource, D3D12 creates an implicit heap that contains the
    // resource allocation. Because Dawn's memory residency management occurs at the resource
    // heap granularity, every directly allocated ResourceHeapAllocation also stores a Heap
    // object. This object is created manually, and must be deleted manually upon deallocation
    // of the committed resource.
    Heap* heap =
        new Heap(committedResource, GetMemorySegment(mDevice, heapType), resourceInfo.SizeInBytes);

    // Calling CreateCommittedResource implicitly calls MakeResident on the resource. We must
    // track this to avoid calling MakeResident a second time.
    mDevice->GetResidencyManager()->TrackResidentAllocation(heap);

    AllocationInfo info;
    info.mMethod = AllocationMethod::kDirect;

    return ResourceHeapAllocation{info,
                                  /*offset*/ 0, std::move(committedResource), heap};
}

void ResourceAllocatorManager::DestroyPool() {
    for (auto& alloc : mPooledHeapAllocators) {
        alloc->DestroyPool();
    }
}

}  // namespace dawn::native::d3d12