src/dawn/native/d3d11/QueueD3D11.cpp - dawn - Git at Google

 // Copyright 2023 The Dawn & Tint Authors
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are met:
 //
 // 1. Redistributions of source code must retain the above copyright notice, this
 //    list of conditions and the following disclaimer.
 //
 // 2. Redistributions in binary form must reproduce the above copyright notice,
 //    this list of conditions and the following disclaimer in the documentation
 //    and/or other materials provided with the distribution.
 //
 // 3. Neither the name of the copyright holder nor the names of its
 //    contributors may be used to endorse or promote products derived from
 //    this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 #include "dawn/native/d3d11/QueueD3D11.h"

 #include <algorithm>
 #include <deque>
 #include <limits>
 #include <utility>
 #include <vector>

 #include "dawn/native/WaitAnySystemEvent.h"
 #include "dawn/native/d3d/D3DError.h"
 #include "dawn/native/d3d11/BufferD3D11.h"
 #include "dawn/native/d3d11/CommandBufferD3D11.h"
 #include "dawn/native/d3d11/DeviceD3D11.h"
 #include "dawn/native/d3d11/SharedFenceD3D11.h"
 #include "dawn/native/d3d11/TextureD3D11.h"
 #include "dawn/platform/DawnPlatform.h"
 #include "dawn/platform/tracing/TraceEvent.h"

 namespace dawn::native::d3d11 {

 class MonitoredQueue final : public Queue {
   public:
     using Queue::Queue;
     MaybeError Initialize();
     MaybeError NextSerial() override;
     ResultOrError<ExecutionSerial> CheckAndUpdateCompletedSerials() override;
     void SetEventOnCompletion(ExecutionSerial serial, HANDLE event) override;

   private:
     ~MonitoredQueue() override = default;
 };

 class UnmonitoredQueue final : public Queue {
   public:
     using Queue::Queue;
     MaybeError Initialize();
     MaybeError NextSerial() override;
     ResultOrError<ExecutionSerial> CheckAndUpdateCompletedSerials() override;
     ResultOrError<bool> WaitForQueueSerial(ExecutionSerial serial, Nanoseconds timeout) override;
     void SetEventOnCompletion(ExecutionSerial serial, HANDLE event) override;

   private:
     ~UnmonitoredQueue() override = default;

     struct SerialEventReceiverPair {
         ExecutionSerial serial;
         SystemEventReceiver receiver;
     };
     // Events associated with submitted commands. They are in old to recent order.
     MutexProtected<std::deque<SerialEventReceiverPair>> mPendingEvents;
 };

 ResultOrError<Ref<Queue>> Queue::Create(Device* device, const QueueDescriptor* descriptor) {
     // TODO(crbug.com/335553337): Choose monitored or unmonitored queue by device capabilities
     if (device->IsToggleEnabled(Toggle::D3D11UseUnmonitoredFence)) {
         Ref<UnmonitoredQueue> unmonitoredQueue =
             AcquireRef(new UnmonitoredQueue(device, descriptor));
         DAWN_TRY(unmonitoredQueue->Initialize());
         return unmonitoredQueue;
     } else {
         Ref<MonitoredQueue> monitoredQueue = AcquireRef(new MonitoredQueue(device, descriptor));
         DAWN_TRY(monitoredQueue->Initialize());
         return monitoredQueue;
     }
 }

 MaybeError Queue::Initialize(bool isMonitored) {
     // Create the fence.
     D3D11_FENCE_FLAG flags = D3D11_FENCE_FLAG_SHARED;
     if (!isMonitored) {
         flags |= D3D11_FENCE_FLAG_NON_MONITORED;
     }
     DAWN_TRY(CheckHRESULT(
         ToBackend(GetDevice())->GetD3D11Device5()->CreateFence(0, flags, IID_PPV_ARGS(&mFence)),
         isMonitored ? "D3D11: creating monitored fence" : "D3D11: creating non-monitored fence"));

     DAWN_TRY_ASSIGN(mSharedFence, SharedFence::Create(ToBackend(GetDevice()),
                                                       "Internal shared DXGI fence", mFence));

     return {};
 }

 MaybeError Queue::InitializePendingContext() {
     // Initialize mPendingCommands. After this, calls to the use the command context
     // are thread safe.
     CommandRecordingContext commandContext;
     DAWN_TRY(commandContext.Initialize(ToBackend(GetDevice())));

     mPendingCommands.Use(
         [&](auto pendingCommandContext) { *pendingCommandContext = std::move(commandContext); });

     // Configure the command context's uniform buffer. This is used to emulate builtins.
     // Creating the buffer is done outside of Initialize because it requires mPendingCommands
     // to already be initialized.
     Ref<BufferBase> uniformBuffer;
     DAWN_TRY_ASSIGN(uniformBuffer,
                     CommandRecordingContext::CreateInternalUniformBuffer(GetDevice()));
     mPendingCommands->SetInternalUniformBuffer(std::move(uniformBuffer));

     return {};
 }

 void Queue::DestroyImpl() {
     // Release the shared fence here to prevent a ref-cycle with the device, but do not destroy the
     // underlying native fence so that we can return a SharedFence on EndAccess after destruction.
     mSharedFence = nullptr;

     mPendingCommands.Use([&](auto pendingCommands) {
         pendingCommands->Destroy();
         mPendingCommandsNeedSubmit.store(false, std::memory_order_release);
     });
 }

 ResultOrError<Ref<d3d::SharedFence>> Queue::GetOrCreateSharedFence() {
     if (mSharedFence == nullptr) {
         DAWN_ASSERT(!IsAlive());
         return SharedFence::Create(ToBackend(GetDevice()), "Internal shared DXGI fence", mFence);
     }
     return mSharedFence;
 }

 ScopedCommandRecordingContext Queue::GetScopedPendingCommandContext(SubmitMode submitMode) {
     return mPendingCommands.Use([&](auto commands) {
         if (submitMode == SubmitMode::Normal) {
             mPendingCommandsNeedSubmit.store(true, std::memory_order_release);
         }
         return ScopedCommandRecordingContext(std::move(commands));
     });
 }

 ScopedSwapStateCommandRecordingContext Queue::GetScopedSwapStatePendingCommandContext(
     SubmitMode submitMode) {
     return mPendingCommands.Use([&](auto commands) {
         if (submitMode == SubmitMode::Normal) {
             mPendingCommandsNeedSubmit.store(true, std::memory_order_release);
         }
         return ScopedSwapStateCommandRecordingContext(std::move(commands));
     });
 }

 MaybeError Queue::SubmitPendingCommands() {
     bool needsSubmit = mPendingCommands.Use([&](auto pendingCommands) {
         pendingCommands->ReleaseKeyedMutexes();
         return mPendingCommandsNeedSubmit.exchange(false, std::memory_order_acq_rel);
     });
     if (needsSubmit) {
         return NextSerial();
     }
     return {};
 }

 MaybeError Queue::SubmitImpl(uint32_t commandCount, CommandBufferBase* const* commands) {
     // CommandBuffer::Execute() will modify the state of the global immediate device context, it may
     // affect following usage of it.
     // TODO(dawn:1770): figure how if we need to track and restore the state of the immediate device
     // context.
     TRACE_EVENT_BEGIN0(GetDevice()->GetPlatform(), Recording, "CommandBufferD3D11::Execute");
     {
         auto commandContext =
             GetScopedSwapStatePendingCommandContext(QueueBase::SubmitMode::Normal);
         for (uint32_t i = 0; i < commandCount; ++i) {
             DAWN_TRY(ToBackend(commands[i])->Execute(&commandContext));
         }
     }
     DAWN_TRY(SubmitPendingCommands());
     TRACE_EVENT_END0(GetDevice()->GetPlatform(), Recording, "CommandBufferD3D11::Execute");

     return {};
 }

 MaybeError Queue::CheckAndMapReadyBuffers(ExecutionSerial completedSerial) {
     auto commandContext = GetScopedPendingCommandContext(QueueBase::SubmitMode::Passive);
     for (auto buffer : mPendingMapBuffers.IterateUpTo(completedSerial)) {
         DAWN_TRY(buffer->FinalizeMap(&commandContext, completedSerial));
     }
     mPendingMapBuffers.ClearUpTo(completedSerial);
     return {};
 }

 void Queue::TrackPendingMapBuffer(Ref<Buffer>&& buffer, ExecutionSerial readySerial) {
     mPendingMapBuffers.Enqueue(buffer, readySerial);
 }

 MaybeError Queue::WriteBufferImpl(BufferBase* buffer,
                                   uint64_t bufferOffset,
                                   const void* data,
                                   size_t size) {
     if (size == 0) {
         // skip the empty write
         return {};
     }

     auto commandContext = GetScopedPendingCommandContext(QueueBase::SubmitMode::Normal);
     return ToBackend(buffer)->Write(&commandContext, bufferOffset, data, size);
 }

 MaybeError Queue::WriteTextureImpl(const ImageCopyTexture& destination,
                                    const void* data,
                                    size_t dataSize,
                                    const TextureDataLayout& dataLayout,
                                    const Extent3D& writeSizePixel) {
     if (writeSizePixel.width == 0 || writeSizePixel.height == 0 ||
         writeSizePixel.depthOrArrayLayers == 0) {
         return {};
     }

     auto commandContext = GetScopedPendingCommandContext(QueueBase::SubmitMode::Normal);
     TextureCopy textureCopy;
     textureCopy.texture = destination.texture;
     textureCopy.mipLevel = destination.mipLevel;
     textureCopy.origin = destination.origin;
     textureCopy.aspect = SelectFormatAspects(destination.texture->GetFormat(), destination.aspect);

     SubresourceRange subresources = GetSubresourcesAffectedByCopy(textureCopy, writeSizePixel);

     Texture* texture = ToBackend(destination.texture);
     DAWN_TRY(texture->SynchronizeTextureBeforeUse(&commandContext));
     return texture->Write(&commandContext, subresources, destination.origin, writeSizePixel,
                           static_cast<const uint8_t*>(data) + dataLayout.offset,
                           dataLayout.bytesPerRow, dataLayout.rowsPerImage);
 }

 bool Queue::HasPendingCommands() const {
     return mPendingCommandsNeedSubmit.load(std::memory_order_acquire);
 }

 void Queue::ForceEventualFlushOfCommands() {}

 MaybeError Queue::WaitForIdleForDestruction() {
     DAWN_TRY(NextSerial());
     // Wait for all in-flight commands to finish executing
     DAWN_TRY_ASSIGN(std::ignore, WaitForQueueSerial(GetLastSubmittedCommandSerial(),
                                                     std::numeric_limits<Nanoseconds>::max()));
     return CheckPassedSerials();
 }

 // MonitoredQueuer:
 MaybeError MonitoredQueue::Initialize() {
     return Queue::Initialize(/*isMonitored=*/true);
 }

 MaybeError MonitoredQueue::NextSerial() {
     auto commandContext = GetScopedPendingCommandContext(SubmitMode::Passive);

     IncrementLastSubmittedCommandSerial();
     TRACE_EVENT1(GetDevice()->GetPlatform(), General, "D3D11Device::SignalFence", "serial",
                  uint64_t(GetLastSubmittedCommandSerial()));
     DAWN_TRY(
         CheckHRESULT(commandContext.Signal(mFence.Get(), uint64_t(GetLastSubmittedCommandSerial())),
                      "D3D11 command queue signal fence"));

     return {};
 }

 ResultOrError<ExecutionSerial> MonitoredQueue::CheckAndUpdateCompletedSerials() {
     ExecutionSerial completedSerial = ExecutionSerial(mFence->GetCompletedValue());
     if (DAWN_UNLIKELY(completedSerial == ExecutionSerial(UINT64_MAX))) {
         // GetCompletedValue returns UINT64_MAX if the device was removed.
         // Try to query the failure reason.
         ID3D11Device* d3d11Device = ToBackend(GetDevice())->GetD3D11Device();
         DAWN_TRY(CheckHRESULT(d3d11Device->GetDeviceRemovedReason(),
                               "ID3D11Device::GetDeviceRemovedReason"));
         // Otherwise, return a generic device lost error.
         return DAWN_DEVICE_LOST_ERROR("Device lost");
     }

     if (completedSerial <= GetCompletedCommandSerial()) {
         return ExecutionSerial(0);
     }

     DAWN_TRY(CheckAndMapReadyBuffers(completedSerial));

     DAWN_TRY(RecycleSystemEventReceivers(completedSerial));

     return completedSerial;
 }

 void MonitoredQueue::SetEventOnCompletion(ExecutionSerial serial, HANDLE event) {
     mFence->SetEventOnCompletion(static_cast<uint64_t>(serial), event);
 }

 // UnmonitoredQueuer:
 MaybeError UnmonitoredQueue::Initialize() {
     // TODO(crbug.com/335553337): Choose monitored or unmonitored queue by device capabilities
     return Queue::Initialize(/*isMonitored=*/true);
 }

 MaybeError UnmonitoredQueue::NextSerial() {
     auto commandContext = GetScopedPendingCommandContext(SubmitMode::Passive);

     IncrementLastSubmittedCommandSerial();
     ExecutionSerial lastSubmittedSerial = GetLastSubmittedCommandSerial();
     // TODO(crbug.com/335553337): only signal fence when it is needed.
     TRACE_EVENT1(GetDevice()->GetPlatform(), General, "D3D11Device::SignalFence", "serial",
                  uint64_t(lastSubmittedSerial));
     DAWN_TRY(CheckHRESULT(commandContext.Signal(mFence.Get(), uint64_t(lastSubmittedSerial)),
                           "D3D11 command queue signal fence"));

     SystemEventReceiver receiver;
     DAWN_TRY_ASSIGN(receiver, GetSystemEventReceiver());
     commandContext.Flush1(D3D11_CONTEXT_TYPE_ALL, receiver.GetPrimitive().Get());
     mPendingEvents->push_back({lastSubmittedSerial, std::move(receiver)});

     return {};
 }

 ResultOrError<ExecutionSerial> UnmonitoredQueue::CheckAndUpdateCompletedSerials() {
     ExecutionSerial completedSerial;
     std::vector<SystemEventReceiver> returnedReceivers;
     DAWN_TRY_ASSIGN(
         completedSerial,
         mPendingEvents.Use([&](auto pendingEvents) -> ResultOrError<ExecutionSerial> {
             if (pendingEvents->empty()) {
                 return GetLastSubmittedCommandSerial();
             }

             StackVector<HANDLE, 8> handles;
             const size_t numberOfHandles =
                 std::min(pendingEvents->size(), static_cast<size_t>(MAXIMUM_WAIT_OBJECTS));
             handles->reserve(numberOfHandles);
             // Gather events in reversed order (from the most recent to the oldest events).
             std::for_each_n(pendingEvents->rbegin(), numberOfHandles, [&handles](const auto& e) {
                 handles->push_back(e.receiver.GetPrimitive().Get());
             });
             DWORD result =
                 WaitForMultipleObjects(handles->size(), handles->data(), /*bWaitAll=*/false,
                                        /*dwMilliseconds=*/0);
             DAWN_INTERNAL_ERROR_IF(result == WAIT_FAILED, "WaitForMultipleObjects() failed");

             DAWN_INTERNAL_ERROR_IF(
                 result >= WAIT_ABANDONED_0 && result < WAIT_ABANDONED_0 + handles->size(),
                 "WaitForMultipleObjects() get abandoned event");

             if (result == WAIT_TIMEOUT) {
                 return GetCompletedCommandSerial();
             }

             DAWN_CHECK(result >= WAIT_OBJECT_0 && result < WAIT_OBJECT_0 + pendingEvents->size());
             const size_t completedEventIndex = result - WAIT_OBJECT_0;
             // |WaitForMultipleObjects()| returns the smallest index, if more than one
             // events are signalled. So the number of completed events are
             // |mPendingEvents.size() - index|.
             const size_t completedEvents = pendingEvents->size() - completedEventIndex;
             auto completedSerial = pendingEvents->at(completedEvents - 1).serial;
             returnedReceivers.reserve(completedEvents);
             std::for_each_n(pendingEvents->begin(), completedEvents, [&returnedReceivers](auto& e) {
                 returnedReceivers.emplace_back(std::move(e.receiver));
             });
             pendingEvents->erase(pendingEvents->begin(), pendingEvents->begin() + completedEvents);

             return completedSerial;
         }));

     DAWN_TRY(CheckAndMapReadyBuffers(completedSerial));

     if (!returnedReceivers.empty()) {
         DAWN_TRY(ReturnSystemEventReceivers(std::move(returnedReceivers)));
     }

     return completedSerial;
 }

 ResultOrError<bool> UnmonitoredQueue::WaitForQueueSerial(ExecutionSerial serial,
                                                          Nanoseconds timeout) {
     ExecutionSerial completedSerial = GetCompletedCommandSerial();
     if (serial <= completedSerial) {
         return true;
     }

     if (serial > GetLastSubmittedCommandSerial()) {
         return DAWN_FORMAT_INTERNAL_ERROR(
             "Wait a serial (%llu) which is greater than last submitted command serial (%llu).",
             uint64_t(serial), uint64_t(GetLastSubmittedCommandSerial()));
     }

     bool didComplete = false;
     std::vector<SystemEventReceiver> returnedReceivers;
     DAWN_TRY_ASSIGN(didComplete, mPendingEvents.Use([&](auto pendingEvents) -> ResultOrError<bool> {
         DAWN_ASSERT(!pendingEvents->empty());
         DAWN_ASSERT(serial >= pendingEvents->front().serial);
         DAWN_ASSERT(serial <= pendingEvents->back().serial);
         auto it = std::lower_bound(
             pendingEvents->begin(), pendingEvents->end(), serial,
             [](const SerialEventReceiverPair& a, ExecutionSerial b) { return a.serial < b; });
         DAWN_ASSERT(it != pendingEvents->end());
         DAWN_ASSERT(it->serial == serial);

         // TODO(crbug.com/335553337): call WaitForSingleObject() without holding the mutex.
         DWORD result =
             WaitForSingleObject(it->receiver.GetPrimitive().Get(), ToMilliseconds(timeout));
         DAWN_INTERNAL_ERROR_IF(result == WAIT_FAILED, "WaitForSingleObject() failed");

         if (result != WAIT_OBJECT_0) {
             return false;
         }

         // Events before |it| should be signalled as well.
         const size_t completedEvents = std::distance(pendingEvents->begin(), it) + 1;
         returnedReceivers.reserve(completedEvents);
         std::for_each_n(pendingEvents->begin(), completedEvents, [&returnedReceivers](auto& e) {
             returnedReceivers.emplace_back(std::move(e.receiver));
         });
         pendingEvents->erase(pendingEvents->begin(), pendingEvents->begin() + completedEvents);
         return true;
     }));

     if (!returnedReceivers.empty()) {
         DAWN_TRY(ReturnSystemEventReceivers(std::move(returnedReceivers)));
     }

     return didComplete;
 }

 void UnmonitoredQueue::SetEventOnCompletion(ExecutionSerial serial, HANDLE event) {
     DAWN_UNREACHABLE();
 }

 }  // namespace dawn::native::d3d11
	// Copyright 2023 The Dawn & Tint Authors
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are met:
	//
	// 1. Redistributions of source code must retain the above copyright notice, this
	// list of conditions and the following disclaimer.
	//
	// 2. Redistributions in binary form must reproduce the above copyright notice,
	// this list of conditions and the following disclaimer in the documentation
	// and/or other materials provided with the distribution.
	//
	// 3. Neither the name of the copyright holder nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
	// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	#include "dawn/native/d3d11/QueueD3D11.h"

	#include <algorithm>
	#include <deque>
	#include <limits>
	#include <utility>
	#include <vector>

	#include "dawn/native/WaitAnySystemEvent.h"
	#include "dawn/native/d3d/D3DError.h"
	#include "dawn/native/d3d11/BufferD3D11.h"
	#include "dawn/native/d3d11/CommandBufferD3D11.h"
	#include "dawn/native/d3d11/DeviceD3D11.h"
	#include "dawn/native/d3d11/SharedFenceD3D11.h"
	#include "dawn/native/d3d11/TextureD3D11.h"
	#include "dawn/platform/DawnPlatform.h"
	#include "dawn/platform/tracing/TraceEvent.h"

	namespace dawn::native::d3d11 {

	class MonitoredQueue final : public Queue {
	public:
	using Queue::Queue;
	MaybeError Initialize();
	MaybeError NextSerial() override;
	ResultOrError<ExecutionSerial> CheckAndUpdateCompletedSerials() override;
	void SetEventOnCompletion(ExecutionSerial serial, HANDLE event) override;

	private:
	~MonitoredQueue() override = default;
	};

	class UnmonitoredQueue final : public Queue {
	public:
	using Queue::Queue;
	MaybeError Initialize();
	MaybeError NextSerial() override;
	ResultOrError<ExecutionSerial> CheckAndUpdateCompletedSerials() override;
	ResultOrError<bool> WaitForQueueSerial(ExecutionSerial serial, Nanoseconds timeout) override;
	void SetEventOnCompletion(ExecutionSerial serial, HANDLE event) override;

	private:
	~UnmonitoredQueue() override = default;

	struct SerialEventReceiverPair {
	ExecutionSerial serial;
	SystemEventReceiver receiver;
	};
	// Events associated with submitted commands. They are in old to recent order.
	MutexProtected<std::deque<SerialEventReceiverPair>> mPendingEvents;
	};

	ResultOrError<Ref<Queue>> Queue::Create(Device* device, const QueueDescriptor* descriptor) {
	// TODO(crbug.com/335553337): Choose monitored or unmonitored queue by device capabilities
	if (device->IsToggleEnabled(Toggle::D3D11UseUnmonitoredFence)) {
	Ref<UnmonitoredQueue> unmonitoredQueue =
	AcquireRef(new UnmonitoredQueue(device, descriptor));
	DAWN_TRY(unmonitoredQueue->Initialize());
	return unmonitoredQueue;
	} else {
	Ref<MonitoredQueue> monitoredQueue = AcquireRef(new MonitoredQueue(device, descriptor));
	DAWN_TRY(monitoredQueue->Initialize());
	return monitoredQueue;
	}
	}

	MaybeError Queue::Initialize(bool isMonitored) {
	// Create the fence.
	D3D11_FENCE_FLAG flags = D3D11_FENCE_FLAG_SHARED;
	if (!isMonitored) {
	flags \|= D3D11_FENCE_FLAG_NON_MONITORED;
	}
	DAWN_TRY(CheckHRESULT(
	ToBackend(GetDevice())->GetD3D11Device5()->CreateFence(0, flags, IID_PPV_ARGS(&mFence)),
	isMonitored ? "D3D11: creating monitored fence" : "D3D11: creating non-monitored fence"));

	DAWN_TRY_ASSIGN(mSharedFence, SharedFence::Create(ToBackend(GetDevice()),
	"Internal shared DXGI fence", mFence));

	return {};
	}

	MaybeError Queue::InitializePendingContext() {
	// Initialize mPendingCommands. After this, calls to the use the command context
	// are thread safe.
	CommandRecordingContext commandContext;
	DAWN_TRY(commandContext.Initialize(ToBackend(GetDevice())));

	mPendingCommands.Use(
	[&](auto pendingCommandContext) { *pendingCommandContext = std::move(commandContext); });

	// Configure the command context's uniform buffer. This is used to emulate builtins.
	// Creating the buffer is done outside of Initialize because it requires mPendingCommands
	// to already be initialized.
	Ref<BufferBase> uniformBuffer;
	DAWN_TRY_ASSIGN(uniformBuffer,
	CommandRecordingContext::CreateInternalUniformBuffer(GetDevice()));
	mPendingCommands->SetInternalUniformBuffer(std::move(uniformBuffer));

	return {};
	}

	void Queue::DestroyImpl() {
	// Release the shared fence here to prevent a ref-cycle with the device, but do not destroy the
	// underlying native fence so that we can return a SharedFence on EndAccess after destruction.
	mSharedFence = nullptr;

	mPendingCommands.Use([&](auto pendingCommands) {
	pendingCommands->Destroy();
	mPendingCommandsNeedSubmit.store(false, std::memory_order_release);
	});
	}

	ResultOrError<Ref<d3d::SharedFence>> Queue::GetOrCreateSharedFence() {
	if (mSharedFence == nullptr) {
	DAWN_ASSERT(!IsAlive());
	return SharedFence::Create(ToBackend(GetDevice()), "Internal shared DXGI fence", mFence);
	}
	return mSharedFence;
	}

	ScopedCommandRecordingContext Queue::GetScopedPendingCommandContext(SubmitMode submitMode) {
	return mPendingCommands.Use([&](auto commands) {
	if (submitMode == SubmitMode::Normal) {
	mPendingCommandsNeedSubmit.store(true, std::memory_order_release);
	}
	return ScopedCommandRecordingContext(std::move(commands));
	});
	}

	ScopedSwapStateCommandRecordingContext Queue::GetScopedSwapStatePendingCommandContext(
	SubmitMode submitMode) {
	return mPendingCommands.Use([&](auto commands) {
	if (submitMode == SubmitMode::Normal) {
	mPendingCommandsNeedSubmit.store(true, std::memory_order_release);
	}
	return ScopedSwapStateCommandRecordingContext(std::move(commands));
	});
	}

	MaybeError Queue::SubmitPendingCommands() {
	bool needsSubmit = mPendingCommands.Use([&](auto pendingCommands) {
	pendingCommands->ReleaseKeyedMutexes();
	return mPendingCommandsNeedSubmit.exchange(false, std::memory_order_acq_rel);
	});
	if (needsSubmit) {
	return NextSerial();
	}
	return {};
	}

	MaybeError Queue::SubmitImpl(uint32_t commandCount, CommandBufferBase* const* commands) {
	// CommandBuffer::Execute() will modify the state of the global immediate device context, it may
	// affect following usage of it.
	// TODO(dawn:1770): figure how if we need to track and restore the state of the immediate device
	// context.
	TRACE_EVENT_BEGIN0(GetDevice()->GetPlatform(), Recording, "CommandBufferD3D11::Execute");
	{
	auto commandContext =
	GetScopedSwapStatePendingCommandContext(QueueBase::SubmitMode::Normal);
	for (uint32_t i = 0; i < commandCount; ++i) {
	DAWN_TRY(ToBackend(commands[i])->Execute(&commandContext));
	}
	}
	DAWN_TRY(SubmitPendingCommands());
	TRACE_EVENT_END0(GetDevice()->GetPlatform(), Recording, "CommandBufferD3D11::Execute");

	return {};
	}

	MaybeError Queue::CheckAndMapReadyBuffers(ExecutionSerial completedSerial) {
	auto commandContext = GetScopedPendingCommandContext(QueueBase::SubmitMode::Passive);
	for (auto buffer : mPendingMapBuffers.IterateUpTo(completedSerial)) {
	DAWN_TRY(buffer->FinalizeMap(&commandContext, completedSerial));
	}
	mPendingMapBuffers.ClearUpTo(completedSerial);
	return {};
	}

	void Queue::TrackPendingMapBuffer(Ref<Buffer>&& buffer, ExecutionSerial readySerial) {
	mPendingMapBuffers.Enqueue(buffer, readySerial);
	}

	MaybeError Queue::WriteBufferImpl(BufferBase* buffer,
	uint64_t bufferOffset,
	const void* data,
	size_t size) {
	if (size == 0) {
	// skip the empty write
	return {};
	}

	auto commandContext = GetScopedPendingCommandContext(QueueBase::SubmitMode::Normal);
	return ToBackend(buffer)->Write(&commandContext, bufferOffset, data, size);
	}

	MaybeError Queue::WriteTextureImpl(const ImageCopyTexture& destination,
	const void* data,
	size_t dataSize,
	const TextureDataLayout& dataLayout,
	const Extent3D& writeSizePixel) {
	if (writeSizePixel.width == 0 \|\| writeSizePixel.height == 0 \|\|
	writeSizePixel.depthOrArrayLayers == 0) {
	return {};
	}

	auto commandContext = GetScopedPendingCommandContext(QueueBase::SubmitMode::Normal);
	TextureCopy textureCopy;
	textureCopy.texture = destination.texture;
	textureCopy.mipLevel = destination.mipLevel;
	textureCopy.origin = destination.origin;
	textureCopy.aspect = SelectFormatAspects(destination.texture->GetFormat(), destination.aspect);

	SubresourceRange subresources = GetSubresourcesAffectedByCopy(textureCopy, writeSizePixel);

	Texture* texture = ToBackend(destination.texture);
	DAWN_TRY(texture->SynchronizeTextureBeforeUse(&commandContext));
	return texture->Write(&commandContext, subresources, destination.origin, writeSizePixel,
	static_cast<const uint8_t*>(data) + dataLayout.offset,
	dataLayout.bytesPerRow, dataLayout.rowsPerImage);
	}

	bool Queue::HasPendingCommands() const {
	return mPendingCommandsNeedSubmit.load(std::memory_order_acquire);
	}

	void Queue::ForceEventualFlushOfCommands() {}

	MaybeError Queue::WaitForIdleForDestruction() {
	DAWN_TRY(NextSerial());
	// Wait for all in-flight commands to finish executing
	DAWN_TRY_ASSIGN(std::ignore, WaitForQueueSerial(GetLastSubmittedCommandSerial(),
	std::numeric_limits<Nanoseconds>::max()));
	return CheckPassedSerials();
	}

	// MonitoredQueuer:
	MaybeError MonitoredQueue::Initialize() {
	return Queue::Initialize(/isMonitored=/true);
	}

	MaybeError MonitoredQueue::NextSerial() {
	auto commandContext = GetScopedPendingCommandContext(SubmitMode::Passive);

	IncrementLastSubmittedCommandSerial();
	TRACE_EVENT1(GetDevice()->GetPlatform(), General, "D3D11Device::SignalFence", "serial",
	uint64_t(GetLastSubmittedCommandSerial()));
	DAWN_TRY(
	CheckHRESULT(commandContext.Signal(mFence.Get(), uint64_t(GetLastSubmittedCommandSerial())),
	"D3D11 command queue signal fence"));

	return {};
	}

	ResultOrError<ExecutionSerial> MonitoredQueue::CheckAndUpdateCompletedSerials() {
	ExecutionSerial completedSerial = ExecutionSerial(mFence->GetCompletedValue());
	if (DAWN_UNLIKELY(completedSerial == ExecutionSerial(UINT64_MAX))) {
	// GetCompletedValue returns UINT64_MAX if the device was removed.
	// Try to query the failure reason.
	ID3D11Device* d3d11Device = ToBackend(GetDevice())->GetD3D11Device();
	DAWN_TRY(CheckHRESULT(d3d11Device->GetDeviceRemovedReason(),
	"ID3D11Device::GetDeviceRemovedReason"));
	// Otherwise, return a generic device lost error.
	return DAWN_DEVICE_LOST_ERROR("Device lost");
	}

	if (completedSerial <= GetCompletedCommandSerial()) {
	return ExecutionSerial(0);
	}

	DAWN_TRY(CheckAndMapReadyBuffers(completedSerial));

	DAWN_TRY(RecycleSystemEventReceivers(completedSerial));

	return completedSerial;
	}

	void MonitoredQueue::SetEventOnCompletion(ExecutionSerial serial, HANDLE event) {
	mFence->SetEventOnCompletion(static_cast<uint64_t>(serial), event);
	}

	// UnmonitoredQueuer:
	MaybeError UnmonitoredQueue::Initialize() {
	// TODO(crbug.com/335553337): Choose monitored or unmonitored queue by device capabilities
	return Queue::Initialize(/isMonitored=/true);
	}

	MaybeError UnmonitoredQueue::NextSerial() {
	auto commandContext = GetScopedPendingCommandContext(SubmitMode::Passive);

	IncrementLastSubmittedCommandSerial();
	ExecutionSerial lastSubmittedSerial = GetLastSubmittedCommandSerial();
	// TODO(crbug.com/335553337): only signal fence when it is needed.
	TRACE_EVENT1(GetDevice()->GetPlatform(), General, "D3D11Device::SignalFence", "serial",
	uint64_t(lastSubmittedSerial));
	DAWN_TRY(CheckHRESULT(commandContext.Signal(mFence.Get(), uint64_t(lastSubmittedSerial)),
	"D3D11 command queue signal fence"));

	SystemEventReceiver receiver;
	DAWN_TRY_ASSIGN(receiver, GetSystemEventReceiver());
	commandContext.Flush1(D3D11_CONTEXT_TYPE_ALL, receiver.GetPrimitive().Get());
	mPendingEvents->push_back({lastSubmittedSerial, std::move(receiver)});

	return {};
	}

	ResultOrError<ExecutionSerial> UnmonitoredQueue::CheckAndUpdateCompletedSerials() {
	ExecutionSerial completedSerial;
	std::vector<SystemEventReceiver> returnedReceivers;
	DAWN_TRY_ASSIGN(
	completedSerial,
	mPendingEvents.Use([&](auto pendingEvents) -> ResultOrError<ExecutionSerial> {
	if (pendingEvents->empty()) {
	return GetLastSubmittedCommandSerial();
	}

	StackVector<HANDLE, 8> handles;
	const size_t numberOfHandles =
	std::min(pendingEvents->size(), static_cast<size_t>(MAXIMUM_WAIT_OBJECTS));
	handles->reserve(numberOfHandles);
	// Gather events in reversed order (from the most recent to the oldest events).
	std::for_each_n(pendingEvents->rbegin(), numberOfHandles, [&handles](const auto& e) {
	handles->push_back(e.receiver.GetPrimitive().Get());
	});
	DWORD result =
	WaitForMultipleObjects(handles->size(), handles->data(), /bWaitAll=/false,
	/dwMilliseconds=/0);
	DAWN_INTERNAL_ERROR_IF(result == WAIT_FAILED, "WaitForMultipleObjects() failed");

	DAWN_INTERNAL_ERROR_IF(
	result >= WAIT_ABANDONED_0 && result < WAIT_ABANDONED_0 + handles->size(),
	"WaitForMultipleObjects() get abandoned event");

	if (result == WAIT_TIMEOUT) {
	return GetCompletedCommandSerial();
	}

	DAWN_CHECK(result >= WAIT_OBJECT_0 && result < WAIT_OBJECT_0 + pendingEvents->size());
	const size_t completedEventIndex = result - WAIT_OBJECT_0;
	// \|WaitForMultipleObjects()\| returns the smallest index, if more than one
	// events are signalled. So the number of completed events are
	// \|mPendingEvents.size() - index\|.
	const size_t completedEvents = pendingEvents->size() - completedEventIndex;
	auto completedSerial = pendingEvents->at(completedEvents - 1).serial;
	returnedReceivers.reserve(completedEvents);
	std::for_each_n(pendingEvents->begin(), completedEvents, [&returnedReceivers](auto& e) {
	returnedReceivers.emplace_back(std::move(e.receiver));
	});
	pendingEvents->erase(pendingEvents->begin(), pendingEvents->begin() + completedEvents);

	return completedSerial;
	}));

	DAWN_TRY(CheckAndMapReadyBuffers(completedSerial));

	if (!returnedReceivers.empty()) {
	DAWN_TRY(ReturnSystemEventReceivers(std::move(returnedReceivers)));
	}

	return completedSerial;
	}

	ResultOrError<bool> UnmonitoredQueue::WaitForQueueSerial(ExecutionSerial serial,
	Nanoseconds timeout) {
	ExecutionSerial completedSerial = GetCompletedCommandSerial();
	if (serial <= completedSerial) {
	return true;
	}

	if (serial > GetLastSubmittedCommandSerial()) {
	return DAWN_FORMAT_INTERNAL_ERROR(
	"Wait a serial (%llu) which is greater than last submitted command serial (%llu).",
	uint64_t(serial), uint64_t(GetLastSubmittedCommandSerial()));
	}

	bool didComplete = false;
	std::vector<SystemEventReceiver> returnedReceivers;
	DAWN_TRY_ASSIGN(didComplete, mPendingEvents.Use([&](auto pendingEvents) -> ResultOrError<bool> {
	DAWN_ASSERT(!pendingEvents->empty());
	DAWN_ASSERT(serial >= pendingEvents->front().serial);
	DAWN_ASSERT(serial <= pendingEvents->back().serial);
	auto it = std::lower_bound(
	pendingEvents->begin(), pendingEvents->end(), serial,
	[](const SerialEventReceiverPair& a, ExecutionSerial b) { return a.serial < b; });
	DAWN_ASSERT(it != pendingEvents->end());
	DAWN_ASSERT(it->serial == serial);

	// TODO(crbug.com/335553337): call WaitForSingleObject() without holding the mutex.
	DWORD result =
	WaitForSingleObject(it->receiver.GetPrimitive().Get(), ToMilliseconds(timeout));
	DAWN_INTERNAL_ERROR_IF(result == WAIT_FAILED, "WaitForSingleObject() failed");

	if (result != WAIT_OBJECT_0) {
	return false;
	}

	// Events before \|it\| should be signalled as well.
	const size_t completedEvents = std::distance(pendingEvents->begin(), it) + 1;
	returnedReceivers.reserve(completedEvents);
	std::for_each_n(pendingEvents->begin(), completedEvents, [&returnedReceivers](auto& e) {
	returnedReceivers.emplace_back(std::move(e.receiver));
	});
	pendingEvents->erase(pendingEvents->begin(), pendingEvents->begin() + completedEvents);
	return true;
	}));

	if (!returnedReceivers.empty()) {
	DAWN_TRY(ReturnSystemEventReceivers(std::move(returnedReceivers)));
	}

	return didComplete;
	}

	void UnmonitoredQueue::SetEventOnCompletion(ExecutionSerial serial, HANDLE event) {
	DAWN_UNREACHABLE();
	}

	} // namespace dawn::native::d3d11