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/*
* Copyright (C) 2020 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.
*/
/**
* @addtogroup Thermal
* @{
*/
/**
* @file thermal.h
*/
#ifndef _ANDROID_THERMAL_H
#define _ANDROID_THERMAL_H
#include <sys/cdefs.h>
/******************************************************************
*
* IMPORTANT NOTICE:
*
* This file is part of Android's set of stable system headers
* exposed by the Android NDK (Native Development Kit).
*
* Third-party source AND binary code relies on the definitions
* here to be FROZEN ON ALL UPCOMING PLATFORM RELEASES.
*
* - DO NOT MODIFY ENUMS (EXCEPT IF YOU ADD NEW 32-BIT VALUES)
* - DO NOT MODIFY CONSTANTS OR FUNCTIONAL MACROS
* - DO NOT CHANGE THE SIGNATURE OF FUNCTIONS IN ANY WAY
* - DO NOT CHANGE THE LAYOUT OR SIZE OF STRUCTURES
*/
/*
* Structures and functions to access thermal status and register/unregister
* thermal status listener in native code.
*/
#include <stdint.h>
#include <sys/types.h>
#if !defined(__INTRODUCED_IN)
#define __INTRODUCED_IN(__api_level) /* nothing */
#endif
#ifdef __cplusplus
extern "C" {
#endif
/**
* Thermal status used in function {@link AThermal_getCurrentThermalStatus} and
* {@link AThermal_StatusCallback}.
*/
enum AThermalStatus {
/** Error in thermal status. */
ATHERMAL_STATUS_ERROR = -1,
/** Not under throttling. */
ATHERMAL_STATUS_NONE = 0,
/** Light throttling where UX is not impacted. */
ATHERMAL_STATUS_LIGHT = 1,
/** Moderate throttling where UX is not largely impacted. */
ATHERMAL_STATUS_MODERATE = 2,
/** Severe throttling where UX is largely impacted. */
ATHERMAL_STATUS_SEVERE = 3,
/** Platform has done everything to reduce power. */
ATHERMAL_STATUS_CRITICAL = 4,
/**
* Key components in platform are shutting down due to thermal condition.
* Device functionalities will be limited.
*/
ATHERMAL_STATUS_EMERGENCY = 5,
/** Need shutdown immediately. */
ATHERMAL_STATUS_SHUTDOWN = 6,
};
/**
* An opaque type representing a handle to a thermal manager.
* An instance of thermal manager must be acquired prior to
* using thermal status APIs and must be released after use.
*
* <p>To use:<ul>
* <li>Create a new thermal manager instance by calling the
* {@link AThermal_acquireManager} function.</li>
* <li>Get current thermal status with
* {@link AThermal_getCurrentThermalStatus}.</li>
* <li>Register a thermal status listener with
* {@link AThermal_registerThermalStatusListener}.</li>
* <li>Unregister a thermal status listener with
* {@link AThermal_unregisterThermalStatusListener}.</li>
* <li>Release the thermal manager instance with
* {@link AThermal_releaseManager}.</li></ul></p>
*
*/
typedef struct AThermalManager AThermalManager;
/**
* Prototype of the function that is called when thermal status changes.
* It's passed the updated thermal status as parameter, as well as the
* pointer provided by the client that registered a callback.
*/
typedef void (*AThermal_StatusCallback)(void *data, AThermalStatus status);
/**
* Acquire an instance of the thermal manager. This must be freed using
* {@link AThermal_releaseManager}.
*
* Available since API level 30.
*
* @return manager instance on success, nullptr on failure.
*/
AThermalManager* AThermal_acquireManager() __INTRODUCED_IN(30);
/**
* Release the thermal manager pointer acquired via
* {@link AThermal_acquireManager}.
*
* Available since API level 30.
*
* @param manager The manager to be released.
*/
void AThermal_releaseManager(AThermalManager *manager) __INTRODUCED_IN(30);
/**
* Gets the current thermal status.
*
* Available since API level 30.
*
* @param manager The manager instance to use to query the thermal status.
* Acquired via {@link AThermal_acquireManager}.
*
* @return current thermal status, ATHERMAL_STATUS_ERROR on failure.
*/
AThermalStatus AThermal_getCurrentThermalStatus(AThermalManager *manager) __INTRODUCED_IN(30);
/**
* Register the thermal status listener for thermal status change.
*
* Available since API level 30.
*
* @param manager The manager instance to use to register.
* Acquired via {@link AThermal_acquireManager}.
* @param callback The callback function to be called when thermal status updated.
* @param data The data pointer to be passed when callback is called.
*
* @return 0 on success
* EINVAL if the listener and data pointer were previously added and not removed.
* EPERM if the required permission is not held.
* EPIPE if communication with the system service has failed.
*/
int AThermal_registerThermalStatusListener(AThermalManager *manager,
AThermal_StatusCallback callback, void *data) __INTRODUCED_IN(30);
/**
* Unregister the thermal status listener previously resgistered.
*
* Available since API level 30.
*
* @param manager The manager instance to use to unregister.
* Acquired via {@link AThermal_acquireManager}.
* @param callback The callback function to be called when thermal status updated.
* @param data The data pointer to be passed when callback is called.
*
* @return 0 on success
* EINVAL if the listener and data pointer were not previously added.
* EPERM if the required permission is not held.
* EPIPE if communication with the system service has failed.
*/
int AThermal_unregisterThermalStatusListener(AThermalManager *manager,
AThermal_StatusCallback callback, void *data) __INTRODUCED_IN(30);
/**
* Provides an estimate of how much thermal headroom the device currently has before
* hitting severe throttling.
*
* Note that this only attempts to track the headroom of slow-moving sensors, such as
* the skin temperature sensor. This means that there is no benefit to calling this function
* more frequently than about once per second, and attempted to call significantly
* more frequently may result in the function returning {@code NaN}.
*
* In addition, in order to be able to provide an accurate forecast, the system does
* not attempt to forecast until it has multiple temperature samples from which to
* extrapolate. This should only take a few seconds from the time of the first call,
* but during this time, no forecasting will occur, and the current headroom will be
* returned regardless of the value of {@code forecastSeconds}.
*
* The value returned is a non-negative float that represents how much of the thermal envelope
* is in use (or is forecasted to be in use). A value of 1.0 indicates that the device is
* (or will be) throttled at {@link #ATHERMAL_STATUS_SEVERE}. Such throttling can affect the
* CPU, GPU, and other subsystems. Values may exceed 1.0, but there is no implied mapping
* to specific thermal levels beyond that point. This means that values greater than 1.0
* may correspond to {@link #ATHERMAL_STATUS_SEVERE}, but may also represent heavier throttling.
*
* A value of 0.0 corresponds to a fixed distance from 1.0, but does not correspond to any
* particular thermal status or temperature. Values on (0.0, 1.0] may be expected to scale
* linearly with temperature, though temperature changes over time are typically not linear.
* Negative values will be clamped to 0.0 before returning.
*
* Available since API level 31.
*
* @param manager The manager instance to use.
* Acquired via {@link AThermal_acquireManager}.
* @param forecastSeconds how many seconds into the future to forecast. Given that device
* conditions may change at any time, forecasts from further in the
* future will likely be less accurate than forecasts in the near future.
* @return a value greater than equal to 0.0, where 1.0 indicates the SEVERE throttling threshold,
* as described above. Returns NaN if the device does not support this functionality or
* if this function is called significantly faster than once per second.
*/
float AThermal_getThermalHeadroom(AThermalManager *manager,
int forecastSeconds) __INTRODUCED_IN(31);
#ifdef __cplusplus
}
#endif
#endif // _ANDROID_THERMAL_H
/** @} */