PowerManager.GetThermalHeadroom(Int32) Method
Definition
Important
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Provides an estimate of how much thermal headroom the device currently has before hitting severe throttling.
[Android.Runtime.Register("getThermalHeadroom", "(I)F", "GetGetThermalHeadroom_IHandler", ApiSince=30)]
public virtual float GetThermalHeadroom (int forecastSeconds);[<Android.Runtime.Register("getThermalHeadroom", "(I)F", "GetGetThermalHeadroom_IHandler", ApiSince=30)>]
abstract member GetThermalHeadroom : int -> single
override this.GetThermalHeadroom : int -> singleParameters
- forecastSeconds
- Int32
how many seconds in 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.
Returns
a value greater than or 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.
- Attributes
Remarks
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 attempts to call significantly more frequently may result in the function returning 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 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 #THERMAL_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 status levels beyond that point. This means that values greater than 1.0 may correspond to #THERMAL_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.
Java documentation for android.os.PowerManager.getThermalHeadroom(int).
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.