Address NDK API review feedback (decd21f0) · Commits · e / os / android_frameworks_native

include/android/system_health.h

+152 −52

Original line number	Diff line number	Diff line
		@@ -16,6 +16,31 @@

		/**
		* @defgroup SystemHealth
		*
		* SystemHealth provides access to data about how various system resources are used by applications.
		*
		* CPU/GPU headroom APIs are designed to be best used by applications with consistent and intense
		* workload such as games to query the remaining capacity headroom over a short period and perform
		* optimization accordingly. Due to the nature of the fast job scheduling and frequency scaling of
		* CPU and GPU, the headroom by nature will have "TOCTOU" problem which makes it less suitable for
		* apps with inconsistent or low workload to take any useful action but simply monitoring. And to
		* avoid oscillation it's not recommended to adjust workload too frequent (on each polling request)
		* or too aggressively. As the headroom calculation is more based on reflecting past history usage
		* than predicting future capacity. Take game as an example, if the API returns CPU headroom of 0 in
		* one scenario (especially if it's constant across multiple calls), or some value significantly
		* smaller than other scenarios, then it can reason that the recent performance result is more CPU
		* bottlenecked. Then reducing the CPU workload intensity can help reserve some headroom to handle
		* the load variance better, which can result in less frame drops or smooth FPS value. On the other
		* hand, if the API returns large CPU headroom constantly, the app can be more confident to increase
		* the workload and expect higher possibility of device meeting its performance expectation.
		* App can also use thermal APIs to read the current thermal status and headroom first, then poll
		* the CPU and GPU headroom if the device is (about to) getting thermal throttled. If the CPU/GPU
		* headrooms provide enough significance such as one valued at 0 while the other at 100, then it can
		* be used to infer that reducing CPU workload could be more efficient to cool down the device.
		* There is a caveat that the power controller may scale down the frequency of the CPU and GPU due
		* to thermal and other reasons, which can result in a higher than usual percentage usage of the
		* capacity.
		*
		* @{
		*/

		@@ -70,28 +95,14 @@ typedef struct ACpuHeadroomParams ACpuHeadroomParams;
		*/
		typedef struct AGpuHeadroomParams AGpuHeadroomParams;

		/**
		* Creates a new instance of ACpuHeadroomParams.
		*
		* When the client finishes using {@link ACpuHeadroomParams},
		* {@link ACpuHeadroomParams_destroy()} must be called to destroy
		* and free up the resources associated with {@link ACpuHeadroomParams}.
		*
		* Available since API level 36.
		*
		* @return A new instance of ACpuHeadroomParams.
		*/
		ACpuHeadroomParams* _Nonnull ACpuHeadroomParams_create(void)
		__INTRODUCED_IN(36);

		typedef enum ACpuHeadroomCalculationType : int32_t {
		/**
		* Use the minimum headroom value within the calculation window.
		* The headroom calculation type bases on minimum value over a specified window.
		* Introduced in API level 36.
		*/
		ACPU_HEADROOM_CALCULATION_TYPE_MIN = 0,
		/**
		* Use the average headroom value within the calculation window.
		* The headroom calculation type bases on average value over a specified window.
		* Introduced in API level 36.
		*/
		ACPU_HEADROOM_CALCULATION_TYPE_AVERAGE = 1,
		@@ -99,24 +110,25 @@ typedef enum ACpuHeadroomCalculationType : int32_t {

		typedef enum AGpuHeadroomCalculationType : int32_t {
		/**
		* Use the minimum headroom value within the calculation window.
		* The headroom calculation type bases on minimum value over a specified window.
		* Introduced in API level 36.
		*/
		AGPU_HEADROOM_CALCULATION_TYPE_MIN = 0,
		/**
		* Use the average headroom value within the calculation window.
		* The headroom calculation type bases on average value over a specified window.
		* Introduced in API level 36.
		*/
		AGPU_HEADROOM_CALCULATION_TYPE_AVERAGE = 1,
		} AGpuHeadroomCalculationType;

		/**
		* Sets the headroom calculation window size in ACpuHeadroomParams.
		* Sets the CPU headroom calculation window size in milliseconds.
		*
		* Available since API level 36.
		*
		* @param params The params to be set.
		* @param windowMillis The window size in milliseconds ranged from [50, 10000]. The smaller the
		* @param windowMillis The window size in milliseconds ranges from
		* {@link ASystemHealth_getCpuHeadroomCalculationWindowRange}. The smaller the
		* window size, the larger fluctuation in the headroom value should be expected.
		* The default value can be retrieved from the
		* {@link #ACpuHeadroomParams_getCalculationWindowMillis} if not set. The device
		@@ -127,23 +139,26 @@ void ACpuHeadroomParams_setCalculationWindowMillis(ACpuHeadroomParams* _Nonnull
		__INTRODUCED_IN(36);

		/**
		* Gets the headroom calculation window size in ACpuHeadroomParams.
		* Gets the CPU headroom calculation window size in milliseconds.
		*
		* This will return the default value chosen by the device if not set.
		*
		* Available since API level 36.
		*
		* @param params The params to be set.
		* @param params The params to read from.
		* @return This will return the default value chosen by the device if the params is not set.
		*/
		int ACpuHeadroomParams_getCalculationWindowMillis(ACpuHeadroomParams* _Nonnull params)
		__INTRODUCED_IN(36);

		/**
		* Sets the headroom calculation window size in AGpuHeadroomParams.
		* Sets the GPU headroom calculation window size in milliseconds.
		*
		* Available since API level 36.
		*
		* @param params The params to be set.
		* @param windowMillis The window size in milliseconds ranged from [50, 10000]. The smaller the
		* @param windowMillis The window size in milliseconds ranges from
		* {@link ASystemHealth_getGpuHeadroomCalculationWindowRange}. The smaller the
		* window size, the larger fluctuation in the headroom value should be expected.
		* The default value can be retrieved from the
		* {@link #AGpuHeadroomParams_getCalculationWindowMillis} if not set. The device
		@@ -154,18 +169,20 @@ void AGpuHeadroomParams_setCalculationWindowMillis(AGpuHeadroomParams* _Nonnull
		__INTRODUCED_IN(36);

		/**
		* Gets the headroom calculation window size in AGpuHeadroomParams.
		* Gets the GPU headroom calculation window size in milliseconds.
		*
		* This will return the default value chosen by the device if not set.
		*
		* Available since API level 36.
		*
		* @param params The params to be set.
		* @param params The params to read from.
		* @return This will return the default value chosen by the device if the params is not set.
		*/
		int AGpuHeadroomParams_getCalculationWindowMillis(AGpuHeadroomParams* _Nonnull params)
		__INTRODUCED_IN(36);

		/**
		* Sets the headroom calculation type in ACpuHeadroomParams.
		* Sets the CPU headroom calculation type in {@link ACpuHeadroomParams}.
		*
		* Available since API level 36.
		*
		@@ -177,11 +194,13 @@ void ACpuHeadroomParams_setCalculationType(ACpuHeadroomParams* _Nonnull params,
		__INTRODUCED_IN(36);

		/**
		* Gets the headroom calculation type in ACpuHeadroomParams.
		* Gets the CPU headroom calculation type in {@link ACpuHeadroomParams}.
		*
		* This will return the default value chosen by the device if not set.
		*
		* Available since API level 36.
		*
		* @param params The params to be set.
		* @param params The params to read from.
		* @return The headroom calculation type.
		*/
		ACpuHeadroomCalculationType
		@@ -189,7 +208,7 @@ ACpuHeadroomParams_getCalculationType(ACpuHeadroomParams* _Nonnull params)
		__INTRODUCED_IN(36);

		/**
		* Sets the headroom calculation type in AGpuHeadroomParams.
		* Sets the GPU headroom calculation type in {@link AGpuHeadroomParams}.
		*
		* Available since API level 36.
		*
		@@ -201,11 +220,13 @@ void AGpuHeadroomParams_setCalculationType(AGpuHeadroomParams* _Nonnull params,
		__INTRODUCED_IN(36);

		/**
		* Gets the headroom calculation type in AGpuHeadroomParams.
		* Gets the GPU headroom calculation type in {@link AGpuHeadroomParams}.
		*
		* This will return the default value chosen by the device if not set.
		*
		* Available since API level 36.
		*
		* @param params The params to be set.
		* @param params The params to read from.
		* @return The headroom calculation type.
		*/
		AGpuHeadroomCalculationType
		@@ -213,50 +234,115 @@ AGpuHeadroomParams_getCalculationType(AGpuHeadroomParams* _Nonnull params)
		__INTRODUCED_IN(36);

		/**
		* Sets the thread TIDs to track in ACpuHeadroomParams.
		* Sets the thread TIDs to track in {@link ACpuHeadroomParams}.
		*
		* The TIDs should belong to the same of the process that will make the headroom call. And they
		* should not have different core affinity.
		*
		* If not set or set to empty, the headroom will be based on the PID of the process making the call.
		*
		* Available since API level 36.
		*
		* @param params The params to be set.
		* @param tids Non-null array of TIDs, maximum 5.
		* @param tids Non-null array of TIDs, where maximum size can be read from
		* {@link ASystemHealth_getMaxCpuHeadroomTidsSize}.
		* @param tidsSize The size of the tids array.
		*/
		void ACpuHeadroomParams_setTids(ACpuHeadroomParams* _Nonnull params, const int* _Nonnull tids,
		int tidsSize)
		size_t tidsSize)
		__INTRODUCED_IN(36);

		/**
		* Creates a new instance of {@link ACpuHeadroomParams}.
		*
		* When the client finishes using {@link ACpuHeadroomParams},
		* {@link ACpuHeadroomParams_destroy} must be called to destroy
		* and free up the resources associated with {@link ACpuHeadroomParams}.
		*
		* Available since API level 36.
		*
		* @return A new instance of {@link ACpuHeadroomParams}.
		*/
		ACpuHeadroomParams* _Nonnull ACpuHeadroomParams_create(void)
		__INTRODUCED_IN(36);

		/**
		* Creates a new instance of AGpuHeadroomParams.
		* Creates a new instance of {@link AGpuHeadroomParams}.
		*
		* When the client finishes using {@link AGpuHeadroomParams},
		* {@link AGpuHeadroomParams_destroy()} must be called to destroy
		* {@link AGpuHeadroomParams_destroy} must be called to destroy
		* and free up the resources associated with {@link AGpuHeadroomParams}.
		*
		* Available since API level 36.
		*
		* @return A new instance of AGpuHeadroomParams.
		* @return A new instance of {@link AGpuHeadroomParams}.
		*/
		AGpuHeadroomParams* _Nonnull AGpuHeadroomParams_create(void)
		__INTRODUCED_IN(36);

		/**
		* Deletes the ACpuHeadroomParams instance.
		* Deletes the {@link ACpuHeadroomParams} instance.
		*
		* Available since API level 36.
		*
		* @param params The params to be deleted.
		*/
		void ACpuHeadroomParams_destroy(ACpuHeadroomParams* _Nonnull params)
		void ACpuHeadroomParams_destroy(ACpuHeadroomParams* _Nullable params)
		__INTRODUCED_IN(36);

		/**
		* Deletes the AGpuHeadroomParams instance.
		* Deletes the {@link AGpuHeadroomParams} instance.
		*
		* Available since API level 36.
		*
		* @param params The params to be deleted.
		*/
		void AGpuHeadroomParams_destroy(AGpuHeadroomParams* _Nonnull params)
		void AGpuHeadroomParams_destroy(AGpuHeadroomParams* _Nullable params)
		__INTRODUCED_IN(36);

		/**
		* Gets the maximum number of TIDs this device supports for getting CPU headroom.
		*
		* See {@link ACpuHeadroomParams_setTids}.
		*
		* Available since API level 36.
		*
		* @param outSize Non-null output pointer to the max size.
		* @return 0 on success.
		* ENOTSUP if the CPU headroom API is unsupported.
		*/
		int ASystemHealth_getMaxCpuHeadroomTidsSize(size_t* _Nonnull outSize);

		/**
		* Gets the range of the calculation window size for CPU headroom.
		*
		* In API version 36, the range will be a superset of [50, 10000].
		*
		* Available since API level 36.
		*
		* @param outMinMillis Non-null output pointer to be set to the minimum window size in milliseconds.
		* @param outMaxMillis Non-null output pointer to be set to the maximum window size in milliseconds.
		* @return 0 on success.
		* ENOTSUP if API is unsupported.
		*/
		int ASystemHealth_getCpuHeadroomCalculationWindowRange(int32_t* _Nonnull outMinMillis,
		int32_t* _Nonnull outMaxMillis)
		__INTRODUCED_IN(36);

		/**
		* Gets the range of the calculation window size for GPU headroom.
		*
		* In API version 36, the range will be a superset of [50, 10000].
		*
		* Available since API level 36.
		*
		* @param outMinMillis Non-null output pointer to be set to the minimum window size in milliseconds.
		* @param outMaxMillis Non-null output pointer to be set to the maximum window size in milliseconds.
		* @return 0 on success.
		* ENOTSUP if API is unsupported.
		*/
		int ASystemHealth_getGpuHeadroomCalculationWindowRange(int32_t* _Nonnull outMinMillis,
		int32_t* _Nonnull outMaxMillis)
		__INTRODUCED_IN(36);

		/**
		@@ -267,15 +353,21 @@ __INTRODUCED_IN(36);
		* be used with the thermal status and headroom to determine if reducing the CPU bound workload can
		* help reduce the device temperature to avoid thermal throttling.
		*
		* If the params are valid, each call will perform at least one synchronous binder transaction that
		* can take more than 1ms. So it's not recommended to call or wait for this on critical threads.
		* Some devices may implement this as an on-demand API with lazy initialization, so the caller
		* should expect higher latency when making the first call (especially with non-default params)
		* since app starts or after changing params, as the device may need to change its data collection.
		*
		* Available since API level 36.
		*
		* @param params The params to customize the CPU headroom calculation, or nullptr to use the default
		* @param params The params to customize the CPU headroom calculation, or nullptr to use default.
		* @param outHeadroom Non-null output pointer to a single float, which will be set to the CPU
		* headroom value. The value will be a single value or `Float.NaN` if it's
		* temporarily unavailable.
		* temporarily unavailable due to server error or not enough user CPU workload.
		* Each valid value ranges from [0, 100], where 0 indicates no more cpu resources
		* can be granted.
		* @return 0 on success
		* @return 0 on success.
		* EPIPE if failed to get the CPU headroom.
		* EPERM if the TIDs do not belong to the same process.
		* ENOTSUP if API or requested params is unsupported.
		@@ -292,15 +384,21 @@ __INTRODUCED_IN(36);
		* be used with the thermal status and headroom to determine if reducing the GPU bound workload can
		* help reduce the device temperature to avoid thermal throttling.
		*
		* If the params are valid, each call will perform at least one synchronous binder transaction that
		* can take more than 1ms. So it's not recommended to call or wait for this on critical threads.
		* Some devices may implement this as an on-demand API with lazy initialization, so the caller
		* should expect higher latency when making the first call (especially with non-default params)
		* since app starts or after changing params, as the device may need to change its data collection.
		*
		* Available since API level 36
		*
		* @param params The params to customize the GPU headroom calculation, or nullptr to use the default
		* @param params The params to customize the GPU headroom calculation, or nullptr to use default
		* @param outHeadroom Non-null output pointer to a single float, which will be set to the GPU
		* headroom value. The value will be a single value or `Float.NaN` if it's
		* temporarily unavailable.
		* Each valid value ranges from [0, 100], where 0 indicates no more gpu resources
		* can be granted.
		* @return 0 on success
		* @return 0 on success.
		* EPIPE if failed to get the GPU headroom.
		* ENOTSUP if API or requested params is unsupported.
		*/
		@@ -311,13 +409,14 @@ __INTRODUCED_IN(36);
		/**
		* Gets minimum polling interval for calling {@link ASystemHealth_getCpuHeadroom} in milliseconds.
		*
		* The getCpuHeadroom API may return cached result if called more frequently than the interval.
		* The {@link ASystemHealth_getCpuHeadroom} API may return cached result if called more frequently
		* than the interval.
		*
		* Available since API level 36.
		*
		* @param outMinIntervalMillis Non-null output pointer to a int64_t, which
		* will be set to the minimum polling interval in milliseconds.
		* @return 0 on success
		* @return 0 on success.
		* EPIPE if failed to get the minimum polling interval.
		* ENOTSUP if API is unsupported.
		*/
		@@ -327,13 +426,14 @@ __INTRODUCED_IN(36);
		/**
		* Gets minimum polling interval for calling {@link ASystemHealth_getGpuHeadroom} in milliseconds.
		*
		* The getGpuHeadroom API may return cached result if called more frequent than the interval.
		* The {@link ASystemHealth_getGpuHeadroom} API may return cached result if called more frequently
		* than the interval.
		*
		* Available since API level 36.
		*
		* @param outMinIntervalMillis Non-null output pointer to a int64_t, which
		* will be set to the minimum polling interval in milliseconds.
		* @return 0 on success
		* @return 0 on success.
		* EPIPE if failed to get the minimum polling interval.
		* ENOTSUP if API is unsupported.
		*/