services/surfaceflinger/Scheduler/Scheduler.h - LeafOS-Project/android_frameworks_native - Gitiles

 /*
  * Copyright 2018 The Android Open Source Project
  *
  * 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.
  */

 #pragma once

 #include <atomic>
 #include <cstdint>
 #include <functional>
 #include <future>
 #include <memory>
 #include <mutex>
 #include <unordered_map>
 #include <utility>

 // TODO(b/129481165): remove the #pragma below and fix conversion issues
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wconversion"
 #pragma clang diagnostic ignored "-Wextra"
 #include <ui/GraphicTypes.h>
 #pragma clang diagnostic pop // ignored "-Wconversion -Wextra"

 #include <ftl/fake_guard.h>
 #include <ftl/optional.h>
 #include <scheduler/Features.h>
 #include <scheduler/Time.h>
 #include <scheduler/VsyncConfig.h>
 #include <ui/DisplayId.h>

 #include "Display/DisplayMap.h"
 #include "Display/DisplayModeRequest.h"
 #include "EventThread.h"
 #include "FrameRateOverrideMappings.h"
 #include "ISchedulerCallback.h"
 #include "LayerHistory.h"
 #include "MessageQueue.h"
 #include "OneShotTimer.h"
 #include "RefreshRateSelector.h"
 #include "Utils/Dumper.h"
 #include "VsyncModulator.h"

 namespace android::scheduler {

 // Opaque handle to scheduler connection.
 struct ConnectionHandle {
     using Id = std::uintptr_t;
     static constexpr Id INVALID_ID = static_cast<Id>(-1);

     Id id = INVALID_ID;

     explicit operator bool() const { return id != INVALID_ID; }
 };

 inline bool operator==(ConnectionHandle lhs, ConnectionHandle rhs) {
     return lhs.id == rhs.id;
 }

 } // namespace android::scheduler

 namespace std {

 template <>
 struct hash<android::scheduler::ConnectionHandle> {
     size_t operator()(android::scheduler::ConnectionHandle handle) const {
         return hash<android::scheduler::ConnectionHandle::Id>()(handle.id);
     }
 };

 } // namespace std

 namespace android {

 class FenceTime;

 namespace frametimeline {
 class TokenManager;
 } // namespace frametimeline

 namespace scheduler {

 using GlobalSignals = RefreshRateSelector::GlobalSignals;

 class VsyncSchedule;

 class Scheduler : android::impl::MessageQueue {
     using Impl = android::impl::MessageQueue;

 public:
     Scheduler(ICompositor&, ISchedulerCallback&, FeatureFlags, sp<VsyncModulator>);
     virtual ~Scheduler();

     void startTimers();

     // TODO(b/241285191): Remove this API by promoting pacesetter in onScreen{Acquired,Released}.
     void setPacesetterDisplay(std::optional<PhysicalDisplayId>) REQUIRES(kMainThreadContext)
             EXCLUDES(mDisplayLock);

     using RefreshRateSelectorPtr = std::shared_ptr<RefreshRateSelector>;

     using ConstVsyncSchedulePtr = std::shared_ptr<const VsyncSchedule>;
     using VsyncSchedulePtr = std::shared_ptr<VsyncSchedule>;

     void registerDisplay(PhysicalDisplayId, RefreshRateSelectorPtr) REQUIRES(kMainThreadContext)
             EXCLUDES(mDisplayLock);
     void unregisterDisplay(PhysicalDisplayId) REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);

     void run();

     using Impl::initVsync;

     using Impl::getScheduledFrameTime;
     using Impl::setDuration;

     using Impl::scheduleConfigure;
     using Impl::scheduleFrame;

     // Schedule an asynchronous or synchronous task on the main thread.
     template <typename F, typename T = std::invoke_result_t<F>>
     [[nodiscard]] std::future<T> schedule(F&& f) {
         auto [task, future] = makeTask(std::move(f));
         postMessage(std::move(task));
         return std::move(future);
     }

     template <typename F, typename T = std::invoke_result_t<F>>
     [[nodiscard]] std::future<T> scheduleDelayed(F&& f, nsecs_t uptimeDelay) {
         auto [task, future] = makeTask(std::move(f));
         postMessageDelayed(std::move(task), uptimeDelay);
         return std::move(future);
     }

     enum class Cycle {
         Render,       // Surface rendering.
         LastComposite // Ahead of display compositing by one refresh period.
     };

     ConnectionHandle createEventThread(Cycle, frametimeline::TokenManager*,
                                        std::chrono::nanoseconds workDuration,
                                        std::chrono::nanoseconds readyDuration);

     sp<IDisplayEventConnection> createDisplayEventConnection(
             ConnectionHandle, EventRegistrationFlags eventRegistration = {},
             const sp<IBinder>& layerHandle = nullptr);

     sp<EventThreadConnection> getEventConnection(ConnectionHandle);

     void onHotplugReceived(ConnectionHandle, PhysicalDisplayId, bool connected);
     void onPrimaryDisplayModeChanged(ConnectionHandle, const FrameRateMode&) EXCLUDES(mPolicyLock);
     void onNonPrimaryDisplayModeChanged(ConnectionHandle, const FrameRateMode&);

     void enableSyntheticVsync(bool = true) REQUIRES(kMainThreadContext);

     void onFrameRateOverridesChanged(ConnectionHandle, PhysicalDisplayId)
             EXCLUDES(mConnectionsLock);

     // Modifies work duration in the event thread.
     void setDuration(ConnectionHandle, std::chrono::nanoseconds workDuration,
                      std::chrono::nanoseconds readyDuration);

     VsyncModulator& vsyncModulator() { return *mVsyncModulator; }

     // In some cases, we should only modulate for the pacesetter display. In those
     // cases, the caller should pass in the relevant display, and the method
     // will no-op if it's not the pacesetter. Other cases are not specific to a
     // display.
     template <typename... Args,
               typename Handler = std::optional<VsyncConfig> (VsyncModulator::*)(Args...)>
     void modulateVsync(std::optional<PhysicalDisplayId> id, Handler handler, Args... args) {
         if (id) {
             std::scoped_lock lock(mDisplayLock);
             ftl::FakeGuard guard(kMainThreadContext);
             if (id != mPacesetterDisplayId) {
                 return;
             }
         }

         if (const auto config = (*mVsyncModulator.*handler)(args...)) {
             setVsyncConfig(*config, getPacesetterVsyncPeriod());
         }
     }

     void setVsyncConfigSet(const VsyncConfigSet&, Period vsyncPeriod);

     // Sets the render rate for the scheduler to run at.
     void setRenderRate(PhysicalDisplayId, Fps);

     void enableHardwareVsync(PhysicalDisplayId) REQUIRES(kMainThreadContext);
     void disableHardwareVsync(PhysicalDisplayId, bool disallow) REQUIRES(kMainThreadContext);

     // Resyncs the scheduler to hardware vsync.
     // If allowToEnable is true, then hardware vsync will be turned on.
     // Otherwise, if hardware vsync is not already enabled then this method will
     // no-op.
     // If refreshRate is nullopt, use the existing refresh rate of the display.
     void resyncToHardwareVsync(PhysicalDisplayId id, bool allowToEnable,
                                std::optional<Fps> refreshRate = std::nullopt)
             EXCLUDES(mDisplayLock) {
         std::scoped_lock lock(mDisplayLock);
         ftl::FakeGuard guard(kMainThreadContext);
         resyncToHardwareVsyncLocked(id, allowToEnable, refreshRate);
     }
     void resync() EXCLUDES(mDisplayLock);
     void forceNextResync() { mLastResyncTime = 0; }

     // Passes a vsync sample to VsyncController. Returns true if
     // VsyncController detected that the vsync period changed and false
     // otherwise.
     bool addResyncSample(PhysicalDisplayId, nsecs_t timestamp,
                          std::optional<nsecs_t> hwcVsyncPeriod);
     void addPresentFence(PhysicalDisplayId, std::shared_ptr<FenceTime>) EXCLUDES(mDisplayLock)
             REQUIRES(kMainThreadContext);

     // Layers are registered on creation, and unregistered when the weak reference expires.
     void registerLayer(Layer*);
     void recordLayerHistory(int32_t id, const LayerProps& layerProps, nsecs_t presentTime,
                             LayerHistory::LayerUpdateType) EXCLUDES(mDisplayLock);
     void setModeChangePending(bool pending);
     void setDefaultFrameRateCompatibility(Layer*);
     void deregisterLayer(Layer*);

     // Detects content using layer history, and selects a matching refresh rate.
     void chooseRefreshRateForContent() EXCLUDES(mDisplayLock);

     void resetIdleTimer();

     // Indicates that touch interaction is taking place.
     void onTouchHint();

     void setDisplayPowerMode(PhysicalDisplayId, hal::PowerMode powerMode)
             REQUIRES(kMainThreadContext);

     ConstVsyncSchedulePtr getVsyncSchedule(std::optional<PhysicalDisplayId> = std::nullopt) const
             EXCLUDES(mDisplayLock);

     VsyncSchedulePtr getVsyncSchedule(std::optional<PhysicalDisplayId> idOpt = std::nullopt)
             EXCLUDES(mDisplayLock) {
         return std::const_pointer_cast<VsyncSchedule>(std::as_const(*this).getVsyncSchedule(idOpt));
     }

     // Returns true if a given vsync timestamp is considered valid vsync
     // for a given uid
     bool isVsyncValid(TimePoint expectedVsyncTimestamp, uid_t uid) const;

     bool isVsyncInPhase(TimePoint expectedVsyncTime, Fps frameRate) const;

     void dump(utils::Dumper&) const;
     void dump(ConnectionHandle, std::string&) const;
     void dumpVsync(std::string&) const EXCLUDES(mDisplayLock);

     // Returns the preferred refresh rate and frame rate for the pacesetter display.
     FrameRateMode getPreferredDisplayMode();

     // Notifies the scheduler about a refresh rate timeline change.
     void onNewVsyncPeriodChangeTimeline(const hal::VsyncPeriodChangeTimeline& timeline);

     // Notifies the scheduler post composition. Returns if recomposite is needed.
     bool onPostComposition(nsecs_t presentTime);

     // Notifies the scheduler when the display size has changed. Called from SF's main thread
     void onActiveDisplayAreaChanged(uint32_t displayArea);

     size_t getEventThreadConnectionCount(ConnectionHandle handle);

     // Stores the preferred refresh rate that an app should run at.
     // FrameRateOverride.refreshRateHz == 0 means no preference.
     void setPreferredRefreshRateForUid(FrameRateOverride);

     void setGameModeRefreshRateForUid(FrameRateOverride);

     // Retrieves the overridden refresh rate for a given uid.
     std::optional<Fps> getFrameRateOverride(uid_t) const EXCLUDES(mDisplayLock);

     Period getPacesetterVsyncPeriod() const EXCLUDES(mDisplayLock) {
         return pacesetterSelectorPtr()->getActiveMode().fps.getPeriod();
     }

     Fps getPacesetterRefreshRate() const EXCLUDES(mDisplayLock) {
         return pacesetterSelectorPtr()->getActiveMode().fps;
     }

     // Returns the framerate of the layer with the given sequence ID
     float getLayerFramerate(nsecs_t now, int32_t id) const {
         return mLayerHistory.getLayerFramerate(now, id);
     }

 private:
     friend class TestableScheduler;

     enum class ContentDetectionState { Off, On };
     enum class TimerState { Reset, Expired };
     enum class TouchState { Inactive, Active };

     // impl::MessageQueue overrides:
     void onFrameSignal(ICompositor&, VsyncId, TimePoint expectedVsyncTime) override;

     // Create a connection on the given EventThread.
     ConnectionHandle createConnection(std::unique_ptr<EventThread>);
     sp<EventThreadConnection> createConnectionInternal(
             EventThread*, EventRegistrationFlags eventRegistration = {},
             const sp<IBinder>& layerHandle = nullptr);

     // Update feature state machine to given state when corresponding timer resets or expires.
     void kernelIdleTimerCallback(TimerState) EXCLUDES(mDisplayLock);
     void idleTimerCallback(TimerState);
     void touchTimerCallback(TimerState);
     void displayPowerTimerCallback(TimerState);

     void resyncToHardwareVsyncLocked(PhysicalDisplayId, bool allowToEnable,
                                      std::optional<Fps> refreshRate = std::nullopt)
             REQUIRES(kMainThreadContext, mDisplayLock);
     void resyncAllToHardwareVsync(bool allowToEnable) EXCLUDES(mDisplayLock);
     void setVsyncConfig(const VsyncConfig&, Period vsyncPeriod);

     // Chooses a pacesetter among the registered displays, unless `pacesetterIdOpt` is specified.
     // The new `mPacesetterDisplayId` is never `std::nullopt`.
     void promotePacesetterDisplay(std::optional<PhysicalDisplayId> pacesetterIdOpt = std::nullopt)
             REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);

     // Changes to the displays (e.g. registering and unregistering) must be made
     // while mDisplayLock is locked, and the new pacesetter then must be promoted while
     // mDisplayLock is still locked. However, a new pacesetter means that
     // MessageQueue and EventThread need to use the new pacesetter's
     // VsyncSchedule, and this must happen while mDisplayLock is *not* locked,
     // or else we may deadlock with EventThread.
     std::shared_ptr<VsyncSchedule> promotePacesetterDisplayLocked(
             std::optional<PhysicalDisplayId> pacesetterIdOpt = std::nullopt)
             REQUIRES(kMainThreadContext, mDisplayLock);
     void applyNewVsyncSchedule(std::shared_ptr<VsyncSchedule>) EXCLUDES(mDisplayLock);

     // Blocks until the pacesetter's idle timer thread exits. `mDisplayLock` must not be locked by
     // the caller on the main thread to avoid deadlock, since the timer thread locks it before exit.
     void demotePacesetterDisplay() REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock, mPolicyLock);

     void registerDisplayInternal(PhysicalDisplayId, RefreshRateSelectorPtr, VsyncSchedulePtr)
             REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);

     struct Policy;

     // Sets the S state of the policy to the T value under mPolicyLock, and chooses a display mode
     // that fulfills the new policy if the state changed. Returns the signals that were considered.
     template <typename S, typename T>
     GlobalSignals applyPolicy(S Policy::*, T&&) EXCLUDES(mPolicyLock);

     struct DisplayModeChoice {
         DisplayModeChoice(FrameRateMode mode, GlobalSignals consideredSignals)
               : mode(std::move(mode)), consideredSignals(consideredSignals) {}

         FrameRateMode mode;
         GlobalSignals consideredSignals;

         bool operator==(const DisplayModeChoice& other) const {
             return mode == other.mode && consideredSignals == other.consideredSignals;
         }

         // For tests.
         friend std::ostream& operator<<(std::ostream& stream, const DisplayModeChoice& choice) {
             return stream << '{' << to_string(*choice.mode.modePtr) << " considering "
                           << choice.consideredSignals.toString().c_str() << '}';
         }
     };

     using DisplayModeChoiceMap = display::PhysicalDisplayMap<PhysicalDisplayId, DisplayModeChoice>;

     // See mDisplayLock for thread safety.
     DisplayModeChoiceMap chooseDisplayModes() const
             REQUIRES(mPolicyLock, mDisplayLock, kMainThreadContext);

     GlobalSignals makeGlobalSignals() const REQUIRES(mPolicyLock);

     bool updateFrameRateOverrides(GlobalSignals, Fps displayRefreshRate) REQUIRES(mPolicyLock);

     void dispatchCachedReportedMode() REQUIRES(mPolicyLock) EXCLUDES(mDisplayLock);

     android::impl::EventThread::ThrottleVsyncCallback makeThrottleVsyncCallback() const;
     android::impl::EventThread::GetVsyncPeriodFunction makeGetVsyncPeriodFunction() const;

     // Stores EventThread associated with a given VSyncSource, and an initial EventThreadConnection.
     struct Connection {
         sp<EventThreadConnection> connection;
         std::unique_ptr<EventThread> thread;
     };

     ConnectionHandle::Id mNextConnectionHandleId = 0;
     mutable std::mutex mConnectionsLock;
     std::unordered_map<ConnectionHandle, Connection> mConnections GUARDED_BY(mConnectionsLock);

     ConnectionHandle mAppConnectionHandle;
     ConnectionHandle mSfConnectionHandle;

     std::atomic<nsecs_t> mLastResyncTime = 0;

     const FeatureFlags mFeatures;

     // Shifts the VSYNC phase during certain transactions and refresh rate changes.
     const sp<VsyncModulator> mVsyncModulator;

     // Used to choose refresh rate if content detection is enabled.
     LayerHistory mLayerHistory;

     // Timer used to monitor touch events.
     ftl::Optional<OneShotTimer> mTouchTimer;
     // Timer used to monitor display power mode.
     ftl::Optional<OneShotTimer> mDisplayPowerTimer;

     ISchedulerCallback& mSchedulerCallback;

     // mDisplayLock may be locked while under mPolicyLock.
     mutable std::mutex mPolicyLock;

     // Only required for reads outside kMainThreadContext. kMainThreadContext is the only writer, so
     // must lock for writes but not reads. See also mPolicyLock for locking order.
     mutable std::mutex mDisplayLock;

     struct Display {
         Display(RefreshRateSelectorPtr selectorPtr, VsyncSchedulePtr schedulePtr)
               : selectorPtr(std::move(selectorPtr)), schedulePtr(std::move(schedulePtr)) {}

         // Effectively const except in move constructor.
         RefreshRateSelectorPtr selectorPtr;
         VsyncSchedulePtr schedulePtr;
     };

     using DisplayRef = std::reference_wrapper<Display>;
     using ConstDisplayRef = std::reference_wrapper<const Display>;

     display::PhysicalDisplayMap<PhysicalDisplayId, Display> mDisplays GUARDED_BY(mDisplayLock)
             GUARDED_BY(kMainThreadContext);

     ftl::Optional<PhysicalDisplayId> mPacesetterDisplayId GUARDED_BY(mDisplayLock)
             GUARDED_BY(kMainThreadContext);

     ftl::Optional<DisplayRef> pacesetterDisplayLocked() REQUIRES(mDisplayLock) {
         return static_cast<const Scheduler*>(this)->pacesetterDisplayLocked().transform(
                 [](const Display& display) { return std::ref(const_cast<Display&>(display)); });
     }

     ftl::Optional<ConstDisplayRef> pacesetterDisplayLocked() const REQUIRES(mDisplayLock) {
         ftl::FakeGuard guard(kMainThreadContext);
         return mPacesetterDisplayId.and_then([this](PhysicalDisplayId pacesetterId)
                                                      REQUIRES(mDisplayLock, kMainThreadContext) {
                                                          return mDisplays.get(pacesetterId);
                                                      });
     }

     RefreshRateSelectorPtr pacesetterSelectorPtr() const EXCLUDES(mDisplayLock) {
         std::scoped_lock lock(mDisplayLock);
         return pacesetterSelectorPtrLocked();
     }

     RefreshRateSelectorPtr pacesetterSelectorPtrLocked() const REQUIRES(mDisplayLock) {
         ftl::FakeGuard guard(kMainThreadContext);
         return pacesetterDisplayLocked()
                 .transform([](const Display& display) { return display.selectorPtr; })
                 .or_else([] { return std::optional<RefreshRateSelectorPtr>(nullptr); })
                 .value();
     }

     ConstVsyncSchedulePtr getVsyncScheduleLocked(
             std::optional<PhysicalDisplayId> = std::nullopt) const REQUIRES(mDisplayLock);

     VsyncSchedulePtr getVsyncScheduleLocked(std::optional<PhysicalDisplayId> idOpt = std::nullopt)
             REQUIRES(mDisplayLock) {
         return std::const_pointer_cast<VsyncSchedule>(
                 static_cast<const Scheduler*>(this)->getVsyncScheduleLocked(idOpt));
     }

     struct Policy {
         // Policy for choosing the display mode.
         LayerHistory::Summary contentRequirements;
         TimerState idleTimer = TimerState::Reset;
         TouchState touch = TouchState::Inactive;
         TimerState displayPowerTimer = TimerState::Expired;
         hal::PowerMode displayPowerMode = hal::PowerMode::ON;

         // Chosen display mode.
         ftl::Optional<FrameRateMode> modeOpt;

         struct ModeChangedParams {
             ConnectionHandle handle;
             FrameRateMode mode;
         };

         // Parameters for latest dispatch of mode change event.
         std::optional<ModeChangedParams> cachedModeChangedParams;
     } mPolicy GUARDED_BY(mPolicyLock);

     std::mutex mVsyncTimelineLock;
     std::optional<hal::VsyncPeriodChangeTimeline> mLastVsyncPeriodChangeTimeline
             GUARDED_BY(mVsyncTimelineLock);
     static constexpr std::chrono::nanoseconds MAX_VSYNC_APPLIED_TIME = 200ms;

     FrameRateOverrideMappings mFrameRateOverrideMappings;
 };

 } // namespace scheduler
 } // namespace android
	/*
	* Copyright 2018 The Android Open Source Project
	*
	* 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.
	*/

	#pragma once

	#include <atomic>
	#include <cstdint>
	#include <functional>
	#include <future>
	#include <memory>
	#include <mutex>
	#include <unordered_map>
	#include <utility>

	// TODO(b/129481165): remove the #pragma below and fix conversion issues
	#pragma clang diagnostic push
	#pragma clang diagnostic ignored "-Wconversion"
	#pragma clang diagnostic ignored "-Wextra"
	#include <ui/GraphicTypes.h>
	#pragma clang diagnostic pop // ignored "-Wconversion -Wextra"

	#include <ftl/fake_guard.h>
	#include <ftl/optional.h>
	#include <scheduler/Features.h>
	#include <scheduler/Time.h>
	#include <scheduler/VsyncConfig.h>
	#include <ui/DisplayId.h>

	#include "Display/DisplayMap.h"
	#include "Display/DisplayModeRequest.h"
	#include "EventThread.h"
	#include "FrameRateOverrideMappings.h"
	#include "ISchedulerCallback.h"
	#include "LayerHistory.h"
	#include "MessageQueue.h"
	#include "OneShotTimer.h"
	#include "RefreshRateSelector.h"
	#include "Utils/Dumper.h"
	#include "VsyncModulator.h"

	namespace android::scheduler {

	// Opaque handle to scheduler connection.
	struct ConnectionHandle {
	using Id = std::uintptr_t;
	static constexpr Id INVALID_ID = static_cast<Id>(-1);

	Id id = INVALID_ID;

	explicit operator bool() const { return id != INVALID_ID; }
	};

	inline bool operator==(ConnectionHandle lhs, ConnectionHandle rhs) {
	return lhs.id == rhs.id;
	}

	} // namespace android::scheduler

	namespace std {

	template <>
	struct hash<android::scheduler::ConnectionHandle> {
	size_t operator()(android::scheduler::ConnectionHandle handle) const {
	return hash<android::scheduler::ConnectionHandle::Id>()(handle.id);
	}
	};

	} // namespace std

	namespace android {

	class FenceTime;

	namespace frametimeline {
	class TokenManager;
	} // namespace frametimeline

	namespace scheduler {

	using GlobalSignals = RefreshRateSelector::GlobalSignals;

	class VsyncSchedule;

	class Scheduler : android::impl::MessageQueue {
	using Impl = android::impl::MessageQueue;

	public:
	Scheduler(ICompositor&, ISchedulerCallback&, FeatureFlags, sp<VsyncModulator>);
	virtual ~Scheduler();

	void startTimers();

	// TODO(b/241285191): Remove this API by promoting pacesetter in onScreen{Acquired,Released}.
	void setPacesetterDisplay(std::optional<PhysicalDisplayId>) REQUIRES(kMainThreadContext)
	EXCLUDES(mDisplayLock);

	using RefreshRateSelectorPtr = std::shared_ptr<RefreshRateSelector>;

	using ConstVsyncSchedulePtr = std::shared_ptr<const VsyncSchedule>;
	using VsyncSchedulePtr = std::shared_ptr<VsyncSchedule>;

	void registerDisplay(PhysicalDisplayId, RefreshRateSelectorPtr) REQUIRES(kMainThreadContext)
	EXCLUDES(mDisplayLock);
	void unregisterDisplay(PhysicalDisplayId) REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);

	void run();

	using Impl::initVsync;

	using Impl::getScheduledFrameTime;
	using Impl::setDuration;

	using Impl::scheduleConfigure;
	using Impl::scheduleFrame;

	// Schedule an asynchronous or synchronous task on the main thread.
	template <typename F, typename T = std::invoke_result_t<F>>
	[[nodiscard]] std::future<T> schedule(F&& f) {
	auto [task, future] = makeTask(std::move(f));
	postMessage(std::move(task));
	return std::move(future);
	}

	template <typename F, typename T = std::invoke_result_t<F>>
	[[nodiscard]] std::future<T> scheduleDelayed(F&& f, nsecs_t uptimeDelay) {
	auto [task, future] = makeTask(std::move(f));
	postMessageDelayed(std::move(task), uptimeDelay);
	return std::move(future);
	}

	enum class Cycle {
	Render, // Surface rendering.
	LastComposite // Ahead of display compositing by one refresh period.
	};

	ConnectionHandle createEventThread(Cycle, frametimeline::TokenManager*,
	std::chrono::nanoseconds workDuration,
	std::chrono::nanoseconds readyDuration);

	sp<IDisplayEventConnection> createDisplayEventConnection(
	ConnectionHandle, EventRegistrationFlags eventRegistration = {},
	const sp<IBinder>& layerHandle = nullptr);

	sp<EventThreadConnection> getEventConnection(ConnectionHandle);

	void onHotplugReceived(ConnectionHandle, PhysicalDisplayId, bool connected);
	void onPrimaryDisplayModeChanged(ConnectionHandle, const FrameRateMode&) EXCLUDES(mPolicyLock);
	void onNonPrimaryDisplayModeChanged(ConnectionHandle, const FrameRateMode&);

	void enableSyntheticVsync(bool = true) REQUIRES(kMainThreadContext);

	void onFrameRateOverridesChanged(ConnectionHandle, PhysicalDisplayId)
	EXCLUDES(mConnectionsLock);

	// Modifies work duration in the event thread.
	void setDuration(ConnectionHandle, std::chrono::nanoseconds workDuration,
	std::chrono::nanoseconds readyDuration);

	VsyncModulator& vsyncModulator() { return *mVsyncModulator; }

	// In some cases, we should only modulate for the pacesetter display. In those
	// cases, the caller should pass in the relevant display, and the method
	// will no-op if it's not the pacesetter. Other cases are not specific to a
	// display.
	template <typename... Args,
	typename Handler = std::optional<VsyncConfig> (VsyncModulator::*)(Args...)>
	void modulateVsync(std::optional<PhysicalDisplayId> id, Handler handler, Args... args) {
	if (id) {
	std::scoped_lock lock(mDisplayLock);
	ftl::FakeGuard guard(kMainThreadContext);
	if (id != mPacesetterDisplayId) {
	return;
	}
	}

	if (const auto config = (mVsyncModulator.handler)(args...)) {
	setVsyncConfig(*config, getPacesetterVsyncPeriod());
	}
	}

	void setVsyncConfigSet(const VsyncConfigSet&, Period vsyncPeriod);

	// Sets the render rate for the scheduler to run at.
	void setRenderRate(PhysicalDisplayId, Fps);

	void enableHardwareVsync(PhysicalDisplayId) REQUIRES(kMainThreadContext);
	void disableHardwareVsync(PhysicalDisplayId, bool disallow) REQUIRES(kMainThreadContext);

	// Resyncs the scheduler to hardware vsync.
	// If allowToEnable is true, then hardware vsync will be turned on.
	// Otherwise, if hardware vsync is not already enabled then this method will
	// no-op.
	// If refreshRate is nullopt, use the existing refresh rate of the display.
	void resyncToHardwareVsync(PhysicalDisplayId id, bool allowToEnable,
	std::optional<Fps> refreshRate = std::nullopt)
	EXCLUDES(mDisplayLock) {
	std::scoped_lock lock(mDisplayLock);
	ftl::FakeGuard guard(kMainThreadContext);
	resyncToHardwareVsyncLocked(id, allowToEnable, refreshRate);
	}
	void resync() EXCLUDES(mDisplayLock);
	void forceNextResync() { mLastResyncTime = 0; }

	// Passes a vsync sample to VsyncController. Returns true if
	// VsyncController detected that the vsync period changed and false
	// otherwise.
	bool addResyncSample(PhysicalDisplayId, nsecs_t timestamp,
	std::optional<nsecs_t> hwcVsyncPeriod);
	void addPresentFence(PhysicalDisplayId, std::shared_ptr<FenceTime>) EXCLUDES(mDisplayLock)
	REQUIRES(kMainThreadContext);

	// Layers are registered on creation, and unregistered when the weak reference expires.
	void registerLayer(Layer*);
	void recordLayerHistory(int32_t id, const LayerProps& layerProps, nsecs_t presentTime,
	LayerHistory::LayerUpdateType) EXCLUDES(mDisplayLock);
	void setModeChangePending(bool pending);
	void setDefaultFrameRateCompatibility(Layer*);
	void deregisterLayer(Layer*);

	// Detects content using layer history, and selects a matching refresh rate.
	void chooseRefreshRateForContent() EXCLUDES(mDisplayLock);

	void resetIdleTimer();

	// Indicates that touch interaction is taking place.
	void onTouchHint();

	void setDisplayPowerMode(PhysicalDisplayId, hal::PowerMode powerMode)
	REQUIRES(kMainThreadContext);

	ConstVsyncSchedulePtr getVsyncSchedule(std::optional<PhysicalDisplayId> = std::nullopt) const
	EXCLUDES(mDisplayLock);

	VsyncSchedulePtr getVsyncSchedule(std::optional<PhysicalDisplayId> idOpt = std::nullopt)
	EXCLUDES(mDisplayLock) {
	return std::const_pointer_cast<VsyncSchedule>(std::as_const(*this).getVsyncSchedule(idOpt));
	}

	// Returns true if a given vsync timestamp is considered valid vsync
	// for a given uid
	bool isVsyncValid(TimePoint expectedVsyncTimestamp, uid_t uid) const;

	bool isVsyncInPhase(TimePoint expectedVsyncTime, Fps frameRate) const;

	void dump(utils::Dumper&) const;
	void dump(ConnectionHandle, std::string&) const;
	void dumpVsync(std::string&) const EXCLUDES(mDisplayLock);

	// Returns the preferred refresh rate and frame rate for the pacesetter display.
	FrameRateMode getPreferredDisplayMode();

	// Notifies the scheduler about a refresh rate timeline change.
	void onNewVsyncPeriodChangeTimeline(const hal::VsyncPeriodChangeTimeline& timeline);

	// Notifies the scheduler post composition. Returns if recomposite is needed.
	bool onPostComposition(nsecs_t presentTime);

	// Notifies the scheduler when the display size has changed. Called from SF's main thread
	void onActiveDisplayAreaChanged(uint32_t displayArea);

	size_t getEventThreadConnectionCount(ConnectionHandle handle);

	// Stores the preferred refresh rate that an app should run at.
	// FrameRateOverride.refreshRateHz == 0 means no preference.
	void setPreferredRefreshRateForUid(FrameRateOverride);

	void setGameModeRefreshRateForUid(FrameRateOverride);

	// Retrieves the overridden refresh rate for a given uid.
	std::optional<Fps> getFrameRateOverride(uid_t) const EXCLUDES(mDisplayLock);

	Period getPacesetterVsyncPeriod() const EXCLUDES(mDisplayLock) {
	return pacesetterSelectorPtr()->getActiveMode().fps.getPeriod();
	}

	Fps getPacesetterRefreshRate() const EXCLUDES(mDisplayLock) {
	return pacesetterSelectorPtr()->getActiveMode().fps;
	}

	// Returns the framerate of the layer with the given sequence ID
	float getLayerFramerate(nsecs_t now, int32_t id) const {
	return mLayerHistory.getLayerFramerate(now, id);
	}

	private:
	friend class TestableScheduler;

	enum class ContentDetectionState { Off, On };
	enum class TimerState { Reset, Expired };
	enum class TouchState { Inactive, Active };

	// impl::MessageQueue overrides:
	void onFrameSignal(ICompositor&, VsyncId, TimePoint expectedVsyncTime) override;

	// Create a connection on the given EventThread.
	ConnectionHandle createConnection(std::unique_ptr<EventThread>);
	sp<EventThreadConnection> createConnectionInternal(
	EventThread*, EventRegistrationFlags eventRegistration = {},
	const sp<IBinder>& layerHandle = nullptr);

	// Update feature state machine to given state when corresponding timer resets or expires.
	void kernelIdleTimerCallback(TimerState) EXCLUDES(mDisplayLock);
	void idleTimerCallback(TimerState);
	void touchTimerCallback(TimerState);
	void displayPowerTimerCallback(TimerState);

	void resyncToHardwareVsyncLocked(PhysicalDisplayId, bool allowToEnable,
	std::optional<Fps> refreshRate = std::nullopt)
	REQUIRES(kMainThreadContext, mDisplayLock);
	void resyncAllToHardwareVsync(bool allowToEnable) EXCLUDES(mDisplayLock);
	void setVsyncConfig(const VsyncConfig&, Period vsyncPeriod);

	// Chooses a pacesetter among the registered displays, unless `pacesetterIdOpt` is specified.
	// The new `mPacesetterDisplayId` is never `std::nullopt`.
	void promotePacesetterDisplay(std::optional<PhysicalDisplayId> pacesetterIdOpt = std::nullopt)
	REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);

	// Changes to the displays (e.g. registering and unregistering) must be made
	// while mDisplayLock is locked, and the new pacesetter then must be promoted while
	// mDisplayLock is still locked. However, a new pacesetter means that
	// MessageQueue and EventThread need to use the new pacesetter's
	// VsyncSchedule, and this must happen while mDisplayLock is not locked,
	// or else we may deadlock with EventThread.
	std::shared_ptr<VsyncSchedule> promotePacesetterDisplayLocked(
	std::optional<PhysicalDisplayId> pacesetterIdOpt = std::nullopt)
	REQUIRES(kMainThreadContext, mDisplayLock);
	void applyNewVsyncSchedule(std::shared_ptr<VsyncSchedule>) EXCLUDES(mDisplayLock);

	// Blocks until the pacesetter's idle timer thread exits. `mDisplayLock` must not be locked by
	// the caller on the main thread to avoid deadlock, since the timer thread locks it before exit.
	void demotePacesetterDisplay() REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock, mPolicyLock);

	void registerDisplayInternal(PhysicalDisplayId, RefreshRateSelectorPtr, VsyncSchedulePtr)
	REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);

	struct Policy;

	// Sets the S state of the policy to the T value under mPolicyLock, and chooses a display mode
	// that fulfills the new policy if the state changed. Returns the signals that were considered.
	template <typename S, typename T>
	GlobalSignals applyPolicy(S Policy::*, T&&) EXCLUDES(mPolicyLock);

	struct DisplayModeChoice {
	DisplayModeChoice(FrameRateMode mode, GlobalSignals consideredSignals)
	: mode(std::move(mode)), consideredSignals(consideredSignals) {}

	FrameRateMode mode;
	GlobalSignals consideredSignals;

	bool operator==(const DisplayModeChoice& other) const {
	return mode == other.mode && consideredSignals == other.consideredSignals;
	}

	// For tests.
	friend std::ostream& operator<<(std::ostream& stream, const DisplayModeChoice& choice) {
	return stream << '{' << to_string(*choice.mode.modePtr) << " considering "
	<< choice.consideredSignals.toString().c_str() << '}';
	}
	};

	using DisplayModeChoiceMap = display::PhysicalDisplayMap<PhysicalDisplayId, DisplayModeChoice>;

	// See mDisplayLock for thread safety.
	DisplayModeChoiceMap chooseDisplayModes() const
	REQUIRES(mPolicyLock, mDisplayLock, kMainThreadContext);

	GlobalSignals makeGlobalSignals() const REQUIRES(mPolicyLock);

	bool updateFrameRateOverrides(GlobalSignals, Fps displayRefreshRate) REQUIRES(mPolicyLock);

	void dispatchCachedReportedMode() REQUIRES(mPolicyLock) EXCLUDES(mDisplayLock);

	android::impl::EventThread::ThrottleVsyncCallback makeThrottleVsyncCallback() const;
	android::impl::EventThread::GetVsyncPeriodFunction makeGetVsyncPeriodFunction() const;

	// Stores EventThread associated with a given VSyncSource, and an initial EventThreadConnection.
	struct Connection {
	sp<EventThreadConnection> connection;
	std::unique_ptr<EventThread> thread;
	};

	ConnectionHandle::Id mNextConnectionHandleId = 0;
	mutable std::mutex mConnectionsLock;
	std::unordered_map<ConnectionHandle, Connection> mConnections GUARDED_BY(mConnectionsLock);

	ConnectionHandle mAppConnectionHandle;
	ConnectionHandle mSfConnectionHandle;

	std::atomic<nsecs_t> mLastResyncTime = 0;

	const FeatureFlags mFeatures;

	// Shifts the VSYNC phase during certain transactions and refresh rate changes.
	const sp<VsyncModulator> mVsyncModulator;

	// Used to choose refresh rate if content detection is enabled.
	LayerHistory mLayerHistory;

	// Timer used to monitor touch events.
	ftl::Optional<OneShotTimer> mTouchTimer;
	// Timer used to monitor display power mode.
	ftl::Optional<OneShotTimer> mDisplayPowerTimer;

	ISchedulerCallback& mSchedulerCallback;

	// mDisplayLock may be locked while under mPolicyLock.
	mutable std::mutex mPolicyLock;

	// Only required for reads outside kMainThreadContext. kMainThreadContext is the only writer, so
	// must lock for writes but not reads. See also mPolicyLock for locking order.
	mutable std::mutex mDisplayLock;

	struct Display {
	Display(RefreshRateSelectorPtr selectorPtr, VsyncSchedulePtr schedulePtr)
	: selectorPtr(std::move(selectorPtr)), schedulePtr(std::move(schedulePtr)) {}

	// Effectively const except in move constructor.
	RefreshRateSelectorPtr selectorPtr;
	VsyncSchedulePtr schedulePtr;
	};

	using DisplayRef = std::reference_wrapper<Display>;
	using ConstDisplayRef = std::reference_wrapper<const Display>;

	display::PhysicalDisplayMap<PhysicalDisplayId, Display> mDisplays GUARDED_BY(mDisplayLock)
	GUARDED_BY(kMainThreadContext);

	ftl::Optional<PhysicalDisplayId> mPacesetterDisplayId GUARDED_BY(mDisplayLock)
	GUARDED_BY(kMainThreadContext);

	ftl::Optional<DisplayRef> pacesetterDisplayLocked() REQUIRES(mDisplayLock) {
	return static_cast<const Scheduler*>(this)->pacesetterDisplayLocked().transform(
	[](const Display& display) { return std::ref(const_cast<Display&>(display)); });
	}

	ftl::Optional<ConstDisplayRef> pacesetterDisplayLocked() const REQUIRES(mDisplayLock) {
	ftl::FakeGuard guard(kMainThreadContext);
	return mPacesetterDisplayId.and_then([this](PhysicalDisplayId pacesetterId)
	REQUIRES(mDisplayLock, kMainThreadContext) {
	return mDisplays.get(pacesetterId);
	});
	}

	RefreshRateSelectorPtr pacesetterSelectorPtr() const EXCLUDES(mDisplayLock) {
	std::scoped_lock lock(mDisplayLock);
	return pacesetterSelectorPtrLocked();
	}

	RefreshRateSelectorPtr pacesetterSelectorPtrLocked() const REQUIRES(mDisplayLock) {
	ftl::FakeGuard guard(kMainThreadContext);
	return pacesetterDisplayLocked()
	.transform([](const Display& display) { return display.selectorPtr; })
	.or_else([] { return std::optional<RefreshRateSelectorPtr>(nullptr); })
	.value();
	}

	ConstVsyncSchedulePtr getVsyncScheduleLocked(
	std::optional<PhysicalDisplayId> = std::nullopt) const REQUIRES(mDisplayLock);

	VsyncSchedulePtr getVsyncScheduleLocked(std::optional<PhysicalDisplayId> idOpt = std::nullopt)
	REQUIRES(mDisplayLock) {
	return std::const_pointer_cast<VsyncSchedule>(
	static_cast<const Scheduler*>(this)->getVsyncScheduleLocked(idOpt));
	}

	struct Policy {
	// Policy for choosing the display mode.
	LayerHistory::Summary contentRequirements;
	TimerState idleTimer = TimerState::Reset;
	TouchState touch = TouchState::Inactive;
	TimerState displayPowerTimer = TimerState::Expired;
	hal::PowerMode displayPowerMode = hal::PowerMode::ON;

	// Chosen display mode.
	ftl::Optional<FrameRateMode> modeOpt;

	struct ModeChangedParams {
	ConnectionHandle handle;
	FrameRateMode mode;
	};

	// Parameters for latest dispatch of mode change event.
	std::optional<ModeChangedParams> cachedModeChangedParams;
	} mPolicy GUARDED_BY(mPolicyLock);

	std::mutex mVsyncTimelineLock;
	std::optional<hal::VsyncPeriodChangeTimeline> mLastVsyncPeriodChangeTimeline
	GUARDED_BY(mVsyncTimelineLock);
	static constexpr std::chrono::nanoseconds MAX_VSYNC_APPLIED_TIME = 200ms;

	FrameRateOverrideMappings mFrameRateOverrideMappings;
	};

	} // namespace scheduler
	} // namespace android