services/surfaceflinger/Scheduler/RefreshRateConfigs.h - platform/frameworks/native - Git at Google

 /*
  * Copyright 2019 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 <android-base/stringprintf.h>
 #include <gui/DisplayEventReceiver.h>

 #include <algorithm>
 #include <numeric>
 #include <optional>
 #include <type_traits>

 #include "DisplayHardware/DisplayMode.h"
 #include "DisplayHardware/HWComposer.h"
 #include "Fps.h"
 #include "Scheduler/SchedulerUtils.h"
 #include "Scheduler/Seamlessness.h"
 #include "Scheduler/StrongTyping.h"

 namespace android::scheduler {

 using namespace std::chrono_literals;

 enum class RefreshRateConfigEvent : unsigned { None = 0b0, Changed = 0b1 };

 inline RefreshRateConfigEvent operator|(RefreshRateConfigEvent lhs, RefreshRateConfigEvent rhs) {
     using T = std::underlying_type_t<RefreshRateConfigEvent>;
     return static_cast<RefreshRateConfigEvent>(static_cast<T>(lhs) | static_cast<T>(rhs));
 }

 using FrameRateOverride = DisplayEventReceiver::Event::FrameRateOverride;

 /**
  * This class is used to encapsulate configuration for refresh rates. It holds information
  * about available refresh rates on the device, and the mapping between the numbers and human
  * readable names.
  */
 class RefreshRateConfigs {
 public:
     // Margin used when matching refresh rates to the content desired ones.
     static constexpr nsecs_t MARGIN_FOR_PERIOD_CALCULATION =
         std::chrono::nanoseconds(800us).count();

     class RefreshRate {
     private:
         // Effectively making the constructor private while allowing
         // std::make_unique to create the object
         struct ConstructorTag {
             explicit ConstructorTag(int) {}
         };

     public:
         RefreshRate(DisplayModeId configId, DisplayModePtr config, Fps fps, ConstructorTag)
               : configId(configId), hwcConfig(config), fps(std::move(fps)) {}

         DisplayModeId getConfigId() const { return configId; }
         nsecs_t getVsyncPeriod() const { return hwcConfig->getVsyncPeriod(); }
         int32_t getConfigGroup() const { return hwcConfig->getConfigGroup(); }
         std::string getName() const { return to_string(fps); }
         Fps getFps() const { return fps; }

         // Checks whether the fps of this RefreshRate struct is within a given min and max refresh
         // rate passed in. Margin of error is applied to the boundaries for approximation.
         bool inPolicy(Fps minRefreshRate, Fps maxRefreshRate) const {
             return minRefreshRate.lessThanOrEqualWithMargin(fps) &&
                     fps.lessThanOrEqualWithMargin(maxRefreshRate);
         }

         bool operator!=(const RefreshRate& other) const {
             return configId != other.configId || hwcConfig != other.hwcConfig;
         }

         bool operator<(const RefreshRate& other) const {
             return getFps().getValue() < other.getFps().getValue();
         }

         bool operator==(const RefreshRate& other) const { return !(*this != other); }

         std::string toString() const;
         friend std::ostream& operator<<(std::ostream& os, const RefreshRate& refreshRate) {
             return os << refreshRate.toString();
         }

     private:
         friend RefreshRateConfigs;
         friend class RefreshRateConfigsTest;

         // This config ID corresponds to the position of the config in the vector that is stored
         // on the device.
         const DisplayModeId configId;
         // The config itself
         DisplayModePtr hwcConfig;
         // Refresh rate in frames per second
         const Fps fps{0.0f};
     };

     using AllRefreshRatesMapType =
             std::unordered_map<DisplayModeId, std::unique_ptr<const RefreshRate>>;

     struct FpsRange {
         Fps min{0.0f};
         Fps max{std::numeric_limits<float>::max()};

         bool operator==(const FpsRange& other) const {
             return min.equalsWithMargin(other.min) && max.equalsWithMargin(other.max);
         }

         bool operator!=(const FpsRange& other) const { return !(*this == other); }

         std::string toString() const {
             return base::StringPrintf("[%s %s]", to_string(min).c_str(), to_string(max).c_str());
         }
     };

     struct Policy {
     private:
         static constexpr int kAllowGroupSwitchingDefault = false;

     public:
         // The default config, used to ensure we only initiate display config switches within the
         // same config group as defaultConfigId's group.
         DisplayModeId defaultConfig;
         // Whether or not we switch config groups to get the best frame rate.
         bool allowGroupSwitching = kAllowGroupSwitchingDefault;
         // The primary refresh rate range represents display manager's general guidance on the
         // display configs we'll consider when switching refresh rates. Unless we get an explicit
         // signal from an app, we should stay within this range.
         FpsRange primaryRange;
         // The app request refresh rate range allows us to consider more display configs when
         // switching refresh rates. Although we should generally stay within the primary range,
         // specific considerations, such as layer frame rate settings specified via the
         // setFrameRate() api, may cause us to go outside the primary range. We never go outside the
         // app request range. The app request range will be greater than or equal to the primary
         // refresh rate range, never smaller.
         FpsRange appRequestRange;

         Policy() = default;

         Policy(DisplayModeId defaultConfig, const FpsRange& range)
               : Policy(defaultConfig, kAllowGroupSwitchingDefault, range, range) {}

         Policy(DisplayModeId defaultConfig, bool allowGroupSwitching, const FpsRange& range)
               : Policy(defaultConfig, allowGroupSwitching, range, range) {}

         Policy(DisplayModeId defaultConfig, const FpsRange& primaryRange,
                const FpsRange& appRequestRange)
               : Policy(defaultConfig, kAllowGroupSwitchingDefault, primaryRange, appRequestRange) {}

         Policy(DisplayModeId defaultConfig, bool allowGroupSwitching, const FpsRange& primaryRange,
                const FpsRange& appRequestRange)
               : defaultConfig(defaultConfig),
                 allowGroupSwitching(allowGroupSwitching),
                 primaryRange(primaryRange),
                 appRequestRange(appRequestRange) {}

         bool operator==(const Policy& other) const {
             return defaultConfig == other.defaultConfig && primaryRange == other.primaryRange &&
                     appRequestRange == other.appRequestRange &&
                     allowGroupSwitching == other.allowGroupSwitching;
         }

         bool operator!=(const Policy& other) const { return !(*this == other); }
         std::string toString() const;
     };

     // Return code set*Policy() to indicate the current policy is unchanged.
     static constexpr int CURRENT_POLICY_UNCHANGED = 1;

     // We maintain the display manager policy and the override policy separately. The override
     // policy is used by CTS tests to get a consistent device state for testing. While the override
     // policy is set, it takes precedence over the display manager policy. Once the override policy
     // is cleared, we revert to using the display manager policy.

     // Sets the display manager policy to choose refresh rates. The return value will be:
     //   - A negative value if the policy is invalid or another error occurred.
     //   - NO_ERROR if the policy was successfully updated, and the current policy is different from
     //     what it was before the call.
     //   - CURRENT_POLICY_UNCHANGED if the policy was successfully updated, but the current policy
     //     is the same as it was before the call.
     status_t setDisplayManagerPolicy(const Policy& policy) EXCLUDES(mLock);
     // Sets the override policy. See setDisplayManagerPolicy() for the meaning of the return value.
     status_t setOverridePolicy(const std::optional<Policy>& policy) EXCLUDES(mLock);
     // Gets the current policy, which will be the override policy if active, and the display manager
     // policy otherwise.
     Policy getCurrentPolicy() const EXCLUDES(mLock);
     // Gets the display manager policy, regardless of whether an override policy is active.
     Policy getDisplayManagerPolicy() const EXCLUDES(mLock);

     // Returns true if config is allowed by the current policy.
     bool isConfigAllowed(DisplayModeId config) const EXCLUDES(mLock);

     // Describes the different options the layer voted for refresh rate
     enum class LayerVoteType {
         NoVote,          // Doesn't care about the refresh rate
         Min,             // Minimal refresh rate available
         Max,             // Maximal refresh rate available
         Heuristic,       // Specific refresh rate that was calculated by platform using a heuristic
         ExplicitDefault, // Specific refresh rate that was provided by the app with Default
                          // compatibility
         ExplicitExactOrMultiple // Specific refresh rate that was provided by the app with
                                 // ExactOrMultiple compatibility
     };

     // Captures the layer requirements for a refresh rate. This will be used to determine the
     // display refresh rate.
     struct LayerRequirement {
         // Layer's name. Used for debugging purposes.
         std::string name;
         // Layer's owner uid
         uid_t ownerUid = static_cast<uid_t>(-1);
         // Layer vote type.
         LayerVoteType vote = LayerVoteType::NoVote;
         // Layer's desired refresh rate, if applicable.
         Fps desiredRefreshRate{0.0f};
         // If a seamless mode switch is required.
         Seamlessness seamlessness = Seamlessness::Default;
         // Layer's weight in the range of [0, 1]. The higher the weight the more impact this layer
         // would have on choosing the refresh rate.
         float weight = 0.0f;
         // Whether layer is in focus or not based on WindowManager's state
         bool focused = false;

         bool operator==(const LayerRequirement& other) const {
             return name == other.name && vote == other.vote &&
                     desiredRefreshRate.equalsWithMargin(other.desiredRefreshRate) &&
                     seamlessness == other.seamlessness && weight == other.weight &&
                     focused == other.focused;
         }

         bool operator!=(const LayerRequirement& other) const { return !(*this == other); }
     };

     // Global state describing signals that affect refresh rate choice.
     struct GlobalSignals {
         // Whether the user touched the screen recently. Used to apply touch boost.
         bool touch = false;
         // True if the system hasn't seen any buffers posted to layers recently.
         bool idle = false;
     };

     // Returns the refresh rate that fits best to the given layers.
     //   layers - The layer requirements to consider.
     //   globalSignals - global state of touch and idle
     //   outSignalsConsidered - An output param that tells the caller whether the refresh rate was
     //                          chosen based on touch boost and/or idle timer.
     RefreshRate getBestRefreshRate(const std::vector<LayerRequirement>& layers,
                                    const GlobalSignals& globalSignals,
                                    GlobalSignals* outSignalsConsidered = nullptr) const
             EXCLUDES(mLock);

     FpsRange getSupportedRefreshRateRange() const EXCLUDES(mLock) {
         std::lock_guard lock(mLock);
         return {mMinSupportedRefreshRate->getFps(), mMaxSupportedRefreshRate->getFps()};
     }

     std::optional<Fps> onKernelTimerChanged(std::optional<DisplayModeId> desiredActiveConfigId,
                                             bool timerExpired) const EXCLUDES(mLock);

     // Returns the highest refresh rate according to the current policy. May change at runtime. Only
     // uses the primary range, not the app request range.
     RefreshRate getMaxRefreshRateByPolicy() const EXCLUDES(mLock);

     // Returns the current refresh rate
     RefreshRate getCurrentRefreshRate() const EXCLUDES(mLock);

     // Returns the current refresh rate, if allowed. Otherwise the default that is allowed by
     // the policy.
     RefreshRate getCurrentRefreshRateByPolicy() const;

     // Returns the refresh rate that corresponds to a DisplayModeId. This may change at
     // runtime.
     // TODO(b/159590486) An invalid config id may be given here if the dipslay configs have changed.
     RefreshRate getRefreshRateFromConfigId(DisplayModeId configId) const EXCLUDES(mLock) {
         std::lock_guard lock(mLock);
         return *mRefreshRates.at(configId);
     };

     // Stores the current configId the device operates at
     void setCurrentConfigId(DisplayModeId configId) EXCLUDES(mLock);

     // Returns a string that represents the layer vote type
     static std::string layerVoteTypeString(LayerVoteType vote);

     // Returns a known frame rate that is the closest to frameRate
     Fps findClosestKnownFrameRate(Fps frameRate) const;

     RefreshRateConfigs(const DisplayModes& configs, DisplayModeId currentConfigId);

     void updateDisplayConfigs(const DisplayModes& configs, DisplayModeId currentConfig)
             EXCLUDES(mLock);

     // Returns whether switching configs (refresh rate or resolution) is possible.
     // TODO(b/158780872): Consider HAL support, and skip frame rate detection if the configs only
     // differ in resolution.
     bool canSwitch() const EXCLUDES(mLock) {
         std::lock_guard lock(mLock);
         return mRefreshRates.size() > 1;
     }

     // Class to enumerate options around toggling the kernel timer on and off. We have an option
     // for no change to avoid extra calls to kernel.
     enum class KernelIdleTimerAction {
         NoChange, // Do not change the idle timer.
         TurnOff,  // Turn off the idle timer.
         TurnOn    // Turn on the idle timer.
     };
     // Checks whether kernel idle timer should be active depending the policy decisions around
     // refresh rates.
     KernelIdleTimerAction getIdleTimerAction() const;

     bool supportsFrameRateOverride() const { return mSupportsFrameRateOverride; }

     // Returns a divider for the current refresh rate
     int getRefreshRateDivider(Fps frameRate) const EXCLUDES(mLock);

     // Returns the frame rate override for each uid
     using UidToFrameRateOverride = std::map<uid_t, Fps>;
     UidToFrameRateOverride getFrameRateOverrides(const std::vector<LayerRequirement>& layers,
                                                  Fps displayFrameRate) const EXCLUDES(mLock);

     void dump(std::string& result) const EXCLUDES(mLock);

 private:
     friend class RefreshRateConfigsTest;

     void constructAvailableRefreshRates() REQUIRES(mLock);

     void getSortedRefreshRateListLocked(
             const std::function<bool(const RefreshRate&)>& shouldAddRefreshRate,
             std::vector<const RefreshRate*>* outRefreshRates) REQUIRES(mLock);

     // Returns the refresh rate with the highest score in the collection specified from begin
     // to end. If there are more than one with the same highest refresh rate, the first one is
     // returned.
     template <typename Iter>
     const RefreshRate* getBestRefreshRate(Iter begin, Iter end) const;

     // Returns number of display frames and remainder when dividing the layer refresh period by
     // display refresh period.
     std::pair<nsecs_t, nsecs_t> getDisplayFrames(nsecs_t layerPeriod, nsecs_t displayPeriod) const;

     // Returns the lowest refresh rate according to the current policy. May change at runtime. Only
     // uses the primary range, not the app request range.
     const RefreshRate& getMinRefreshRateByPolicyLocked() const REQUIRES(mLock);

     // Returns the highest refresh rate according to the current policy. May change at runtime. Only
     // uses the primary range, not the app request range.
     const RefreshRate& getMaxRefreshRateByPolicyLocked() const REQUIRES(mLock);

     // Returns the current refresh rate, if allowed. Otherwise the default that is allowed by
     // the policy.
     const RefreshRate& getCurrentRefreshRateByPolicyLocked() const REQUIRES(mLock);

     const Policy* getCurrentPolicyLocked() const REQUIRES(mLock);
     bool isPolicyValidLocked(const Policy& policy) const REQUIRES(mLock);

     // Return the display refresh rate divider to match the layer
     // frame rate, or 0 if the display refresh rate is not a multiple of the
     // layer refresh rate.
     static int getFrameRateDivider(Fps displayFrameRate, Fps layerFrameRate);

     // calculates a score for a layer. Used to determine the display refresh rate
     // and the frame rate override for certains applications.
     float calculateLayerScoreLocked(const LayerRequirement&, const RefreshRate&,
                                     bool isSeamlessSwitch) const REQUIRES(mLock);

     // The list of refresh rates, indexed by display config ID. This may change after this
     // object is initialized.
     AllRefreshRatesMapType mRefreshRates GUARDED_BY(mLock);

     // The list of refresh rates in the primary range of the current policy, ordered by vsyncPeriod
     // (the first element is the lowest refresh rate).
     std::vector<const RefreshRate*> mPrimaryRefreshRates GUARDED_BY(mLock);

     // The list of refresh rates in the app request range of the current policy, ordered by
     // vsyncPeriod (the first element is the lowest refresh rate).
     std::vector<const RefreshRate*> mAppRequestRefreshRates GUARDED_BY(mLock);

     // The current config. This will change at runtime. This is set by SurfaceFlinger on
     // the main thread, and read by the Scheduler (and other objects) on other threads.
     const RefreshRate* mCurrentRefreshRate GUARDED_BY(mLock);

     // The policy values will change at runtime. They're set by SurfaceFlinger on the main thread,
     // and read by the Scheduler (and other objects) on other threads.
     Policy mDisplayManagerPolicy GUARDED_BY(mLock);
     std::optional<Policy> mOverridePolicy GUARDED_BY(mLock);

     // The min and max refresh rates supported by the device.
     // This may change at runtime.
     const RefreshRate* mMinSupportedRefreshRate GUARDED_BY(mLock);
     const RefreshRate* mMaxSupportedRefreshRate GUARDED_BY(mLock);

     mutable std::mutex mLock;

     // A sorted list of known frame rates that a Heuristic layer will choose
     // from based on the closest value.
     const std::vector<Fps> mKnownFrameRates;

     bool mSupportsFrameRateOverride;
 };

 } // namespace android::scheduler
	/*
	* Copyright 2019 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 <android-base/stringprintf.h>
	#include <gui/DisplayEventReceiver.h>

	#include <algorithm>
	#include <numeric>
	#include <optional>
	#include <type_traits>

	#include "DisplayHardware/DisplayMode.h"
	#include "DisplayHardware/HWComposer.h"
	#include "Fps.h"
	#include "Scheduler/SchedulerUtils.h"
	#include "Scheduler/Seamlessness.h"
	#include "Scheduler/StrongTyping.h"

	namespace android::scheduler {

	using namespace std::chrono_literals;

	enum class RefreshRateConfigEvent : unsigned { None = 0b0, Changed = 0b1 };

	inline RefreshRateConfigEvent operator\|(RefreshRateConfigEvent lhs, RefreshRateConfigEvent rhs) {
	using T = std::underlying_type_t<RefreshRateConfigEvent>;
	return static_cast<RefreshRateConfigEvent>(static_cast<T>(lhs) \| static_cast<T>(rhs));
	}

	using FrameRateOverride = DisplayEventReceiver::Event::FrameRateOverride;

	/**
	* This class is used to encapsulate configuration for refresh rates. It holds information
	* about available refresh rates on the device, and the mapping between the numbers and human
	* readable names.
	*/
	class RefreshRateConfigs {
	public:
	// Margin used when matching refresh rates to the content desired ones.
	static constexpr nsecs_t MARGIN_FOR_PERIOD_CALCULATION =
	std::chrono::nanoseconds(800us).count();

	class RefreshRate {
	private:
	// Effectively making the constructor private while allowing
	// std::make_unique to create the object
	struct ConstructorTag {
	explicit ConstructorTag(int) {}
	};

	public:
	RefreshRate(DisplayModeId configId, DisplayModePtr config, Fps fps, ConstructorTag)
	: configId(configId), hwcConfig(config), fps(std::move(fps)) {}

	DisplayModeId getConfigId() const { return configId; }
	nsecs_t getVsyncPeriod() const { return hwcConfig->getVsyncPeriod(); }
	int32_t getConfigGroup() const { return hwcConfig->getConfigGroup(); }
	std::string getName() const { return to_string(fps); }
	Fps getFps() const { return fps; }

	// Checks whether the fps of this RefreshRate struct is within a given min and max refresh
	// rate passed in. Margin of error is applied to the boundaries for approximation.
	bool inPolicy(Fps minRefreshRate, Fps maxRefreshRate) const {
	return minRefreshRate.lessThanOrEqualWithMargin(fps) &&
	fps.lessThanOrEqualWithMargin(maxRefreshRate);
	}

	bool operator!=(const RefreshRate& other) const {
	return configId != other.configId \|\| hwcConfig != other.hwcConfig;
	}

	bool operator<(const RefreshRate& other) const {
	return getFps().getValue() < other.getFps().getValue();
	}

	bool operator==(const RefreshRate& other) const { return !(*this != other); }

	std::string toString() const;
	friend std::ostream& operator<<(std::ostream& os, const RefreshRate& refreshRate) {
	return os << refreshRate.toString();
	}

	private:
	friend RefreshRateConfigs;
	friend class RefreshRateConfigsTest;

	// This config ID corresponds to the position of the config in the vector that is stored
	// on the device.
	const DisplayModeId configId;
	// The config itself
	DisplayModePtr hwcConfig;
	// Refresh rate in frames per second
	const Fps fps{0.0f};
	};

	using AllRefreshRatesMapType =
	std::unordered_map<DisplayModeId, std::unique_ptr<const RefreshRate>>;

	struct FpsRange {
	Fps min{0.0f};
	Fps max{std::numeric_limits<float>::max()};

	bool operator==(const FpsRange& other) const {
	return min.equalsWithMargin(other.min) && max.equalsWithMargin(other.max);
	}

	bool operator!=(const FpsRange& other) const { return !(*this == other); }

	std::string toString() const {
	return base::StringPrintf("[%s %s]", to_string(min).c_str(), to_string(max).c_str());
	}
	};

	struct Policy {
	private:
	static constexpr int kAllowGroupSwitchingDefault = false;

	public:
	// The default config, used to ensure we only initiate display config switches within the
	// same config group as defaultConfigId's group.
	DisplayModeId defaultConfig;
	// Whether or not we switch config groups to get the best frame rate.
	bool allowGroupSwitching = kAllowGroupSwitchingDefault;
	// The primary refresh rate range represents display manager's general guidance on the
	// display configs we'll consider when switching refresh rates. Unless we get an explicit
	// signal from an app, we should stay within this range.
	FpsRange primaryRange;
	// The app request refresh rate range allows us to consider more display configs when
	// switching refresh rates. Although we should generally stay within the primary range,
	// specific considerations, such as layer frame rate settings specified via the
	// setFrameRate() api, may cause us to go outside the primary range. We never go outside the
	// app request range. The app request range will be greater than or equal to the primary
	// refresh rate range, never smaller.
	FpsRange appRequestRange;

	Policy() = default;

	Policy(DisplayModeId defaultConfig, const FpsRange& range)
	: Policy(defaultConfig, kAllowGroupSwitchingDefault, range, range) {}

	Policy(DisplayModeId defaultConfig, bool allowGroupSwitching, const FpsRange& range)
	: Policy(defaultConfig, allowGroupSwitching, range, range) {}

	Policy(DisplayModeId defaultConfig, const FpsRange& primaryRange,
	const FpsRange& appRequestRange)
	: Policy(defaultConfig, kAllowGroupSwitchingDefault, primaryRange, appRequestRange) {}

	Policy(DisplayModeId defaultConfig, bool allowGroupSwitching, const FpsRange& primaryRange,
	const FpsRange& appRequestRange)
	: defaultConfig(defaultConfig),
	allowGroupSwitching(allowGroupSwitching),
	primaryRange(primaryRange),
	appRequestRange(appRequestRange) {}

	bool operator==(const Policy& other) const {
	return defaultConfig == other.defaultConfig && primaryRange == other.primaryRange &&
	appRequestRange == other.appRequestRange &&
	allowGroupSwitching == other.allowGroupSwitching;
	}

	bool operator!=(const Policy& other) const { return !(*this == other); }
	std::string toString() const;
	};

	// Return code set*Policy() to indicate the current policy is unchanged.
	static constexpr int CURRENT_POLICY_UNCHANGED = 1;

	// We maintain the display manager policy and the override policy separately. The override
	// policy is used by CTS tests to get a consistent device state for testing. While the override
	// policy is set, it takes precedence over the display manager policy. Once the override policy
	// is cleared, we revert to using the display manager policy.

	// Sets the display manager policy to choose refresh rates. The return value will be:
	// - A negative value if the policy is invalid or another error occurred.
	// - NO_ERROR if the policy was successfully updated, and the current policy is different from
	// what it was before the call.
	// - CURRENT_POLICY_UNCHANGED if the policy was successfully updated, but the current policy
	// is the same as it was before the call.
	status_t setDisplayManagerPolicy(const Policy& policy) EXCLUDES(mLock);
	// Sets the override policy. See setDisplayManagerPolicy() for the meaning of the return value.
	status_t setOverridePolicy(const std::optional<Policy>& policy) EXCLUDES(mLock);
	// Gets the current policy, which will be the override policy if active, and the display manager
	// policy otherwise.
	Policy getCurrentPolicy() const EXCLUDES(mLock);
	// Gets the display manager policy, regardless of whether an override policy is active.
	Policy getDisplayManagerPolicy() const EXCLUDES(mLock);

	// Returns true if config is allowed by the current policy.
	bool isConfigAllowed(DisplayModeId config) const EXCLUDES(mLock);

	// Describes the different options the layer voted for refresh rate
	enum class LayerVoteType {
	NoVote, // Doesn't care about the refresh rate
	Min, // Minimal refresh rate available
	Max, // Maximal refresh rate available
	Heuristic, // Specific refresh rate that was calculated by platform using a heuristic
	ExplicitDefault, // Specific refresh rate that was provided by the app with Default
	// compatibility
	ExplicitExactOrMultiple // Specific refresh rate that was provided by the app with
	// ExactOrMultiple compatibility
	};

	// Captures the layer requirements for a refresh rate. This will be used to determine the
	// display refresh rate.
	struct LayerRequirement {
	// Layer's name. Used for debugging purposes.
	std::string name;
	// Layer's owner uid
	uid_t ownerUid = static_cast<uid_t>(-1);
	// Layer vote type.
	LayerVoteType vote = LayerVoteType::NoVote;
	// Layer's desired refresh rate, if applicable.
	Fps desiredRefreshRate{0.0f};
	// If a seamless mode switch is required.
	Seamlessness seamlessness = Seamlessness::Default;
	// Layer's weight in the range of [0, 1]. The higher the weight the more impact this layer
	// would have on choosing the refresh rate.
	float weight = 0.0f;
	// Whether layer is in focus or not based on WindowManager's state
	bool focused = false;

	bool operator==(const LayerRequirement& other) const {
	return name == other.name && vote == other.vote &&
	desiredRefreshRate.equalsWithMargin(other.desiredRefreshRate) &&
	seamlessness == other.seamlessness && weight == other.weight &&
	focused == other.focused;
	}

	bool operator!=(const LayerRequirement& other) const { return !(*this == other); }
	};

	// Global state describing signals that affect refresh rate choice.
	struct GlobalSignals {
	// Whether the user touched the screen recently. Used to apply touch boost.
	bool touch = false;
	// True if the system hasn't seen any buffers posted to layers recently.
	bool idle = false;
	};

	// Returns the refresh rate that fits best to the given layers.
	// layers - The layer requirements to consider.
	// globalSignals - global state of touch and idle
	// outSignalsConsidered - An output param that tells the caller whether the refresh rate was
	// chosen based on touch boost and/or idle timer.
	RefreshRate getBestRefreshRate(const std::vector<LayerRequirement>& layers,
	const GlobalSignals& globalSignals,
	GlobalSignals* outSignalsConsidered = nullptr) const
	EXCLUDES(mLock);

	FpsRange getSupportedRefreshRateRange() const EXCLUDES(mLock) {
	std::lock_guard lock(mLock);
	return {mMinSupportedRefreshRate->getFps(), mMaxSupportedRefreshRate->getFps()};
	}

	std::optional<Fps> onKernelTimerChanged(std::optional<DisplayModeId> desiredActiveConfigId,
	bool timerExpired) const EXCLUDES(mLock);

	// Returns the highest refresh rate according to the current policy. May change at runtime. Only
	// uses the primary range, not the app request range.
	RefreshRate getMaxRefreshRateByPolicy() const EXCLUDES(mLock);

	// Returns the current refresh rate
	RefreshRate getCurrentRefreshRate() const EXCLUDES(mLock);

	// Returns the current refresh rate, if allowed. Otherwise the default that is allowed by
	// the policy.
	RefreshRate getCurrentRefreshRateByPolicy() const;

	// Returns the refresh rate that corresponds to a DisplayModeId. This may change at
	// runtime.
	// TODO(b/159590486) An invalid config id may be given here if the dipslay configs have changed.
	RefreshRate getRefreshRateFromConfigId(DisplayModeId configId) const EXCLUDES(mLock) {
	std::lock_guard lock(mLock);
	return *mRefreshRates.at(configId);
	};

	// Stores the current configId the device operates at
	void setCurrentConfigId(DisplayModeId configId) EXCLUDES(mLock);

	// Returns a string that represents the layer vote type
	static std::string layerVoteTypeString(LayerVoteType vote);

	// Returns a known frame rate that is the closest to frameRate
	Fps findClosestKnownFrameRate(Fps frameRate) const;

	RefreshRateConfigs(const DisplayModes& configs, DisplayModeId currentConfigId);

	void updateDisplayConfigs(const DisplayModes& configs, DisplayModeId currentConfig)
	EXCLUDES(mLock);

	// Returns whether switching configs (refresh rate or resolution) is possible.
	// TODO(b/158780872): Consider HAL support, and skip frame rate detection if the configs only
	// differ in resolution.
	bool canSwitch() const EXCLUDES(mLock) {
	std::lock_guard lock(mLock);
	return mRefreshRates.size() > 1;
	}

	// Class to enumerate options around toggling the kernel timer on and off. We have an option
	// for no change to avoid extra calls to kernel.
	enum class KernelIdleTimerAction {
	NoChange, // Do not change the idle timer.
	TurnOff, // Turn off the idle timer.
	TurnOn // Turn on the idle timer.
	};
	// Checks whether kernel idle timer should be active depending the policy decisions around
	// refresh rates.
	KernelIdleTimerAction getIdleTimerAction() const;

	bool supportsFrameRateOverride() const { return mSupportsFrameRateOverride; }

	// Returns a divider for the current refresh rate
	int getRefreshRateDivider(Fps frameRate) const EXCLUDES(mLock);

	// Returns the frame rate override for each uid
	using UidToFrameRateOverride = std::map<uid_t, Fps>;
	UidToFrameRateOverride getFrameRateOverrides(const std::vector<LayerRequirement>& layers,
	Fps displayFrameRate) const EXCLUDES(mLock);

	void dump(std::string& result) const EXCLUDES(mLock);

	private:
	friend class RefreshRateConfigsTest;

	void constructAvailableRefreshRates() REQUIRES(mLock);

	void getSortedRefreshRateListLocked(
	const std::function<bool(const RefreshRate&)>& shouldAddRefreshRate,
	std::vector<const RefreshRate> outRefreshRates) REQUIRES(mLock);

	// Returns the refresh rate with the highest score in the collection specified from begin
	// to end. If there are more than one with the same highest refresh rate, the first one is
	// returned.
	template <typename Iter>
	const RefreshRate* getBestRefreshRate(Iter begin, Iter end) const;

	// Returns number of display frames and remainder when dividing the layer refresh period by
	// display refresh period.
	std::pair<nsecs_t, nsecs_t> getDisplayFrames(nsecs_t layerPeriod, nsecs_t displayPeriod) const;

	// Returns the lowest refresh rate according to the current policy. May change at runtime. Only
	// uses the primary range, not the app request range.
	const RefreshRate& getMinRefreshRateByPolicyLocked() const REQUIRES(mLock);

	// Returns the highest refresh rate according to the current policy. May change at runtime. Only
	// uses the primary range, not the app request range.
	const RefreshRate& getMaxRefreshRateByPolicyLocked() const REQUIRES(mLock);

	// Returns the current refresh rate, if allowed. Otherwise the default that is allowed by
	// the policy.
	const RefreshRate& getCurrentRefreshRateByPolicyLocked() const REQUIRES(mLock);

	const Policy* getCurrentPolicyLocked() const REQUIRES(mLock);
	bool isPolicyValidLocked(const Policy& policy) const REQUIRES(mLock);

	// Return the display refresh rate divider to match the layer
	// frame rate, or 0 if the display refresh rate is not a multiple of the
	// layer refresh rate.
	static int getFrameRateDivider(Fps displayFrameRate, Fps layerFrameRate);

	// calculates a score for a layer. Used to determine the display refresh rate
	// and the frame rate override for certains applications.
	float calculateLayerScoreLocked(const LayerRequirement&, const RefreshRate&,
	bool isSeamlessSwitch) const REQUIRES(mLock);

	// The list of refresh rates, indexed by display config ID. This may change after this
	// object is initialized.
	AllRefreshRatesMapType mRefreshRates GUARDED_BY(mLock);

	// The list of refresh rates in the primary range of the current policy, ordered by vsyncPeriod
	// (the first element is the lowest refresh rate).
	std::vector<const RefreshRate*> mPrimaryRefreshRates GUARDED_BY(mLock);

	// The list of refresh rates in the app request range of the current policy, ordered by
	// vsyncPeriod (the first element is the lowest refresh rate).
	std::vector<const RefreshRate*> mAppRequestRefreshRates GUARDED_BY(mLock);

	// The current config. This will change at runtime. This is set by SurfaceFlinger on
	// the main thread, and read by the Scheduler (and other objects) on other threads.
	const RefreshRate* mCurrentRefreshRate GUARDED_BY(mLock);

	// The policy values will change at runtime. They're set by SurfaceFlinger on the main thread,
	// and read by the Scheduler (and other objects) on other threads.
	Policy mDisplayManagerPolicy GUARDED_BY(mLock);
	std::optional<Policy> mOverridePolicy GUARDED_BY(mLock);

	// The min and max refresh rates supported by the device.
	// This may change at runtime.
	const RefreshRate* mMinSupportedRefreshRate GUARDED_BY(mLock);
	const RefreshRate* mMaxSupportedRefreshRate GUARDED_BY(mLock);

	mutable std::mutex mLock;

	// A sorted list of known frame rates that a Heuristic layer will choose
	// from based on the closest value.
	const std::vector<Fps> mKnownFrameRates;

	bool mSupportsFrameRateOverride;
	};

	} // namespace android::scheduler