MemoryBudgetInfo Class

Definition

[Android.Runtime.Register("android/content/pm/MemoryBudgetInfo", ApiSince=37, DoNotGenerateAcw=true)]
public sealed class MemoryBudgetInfo : Java.Lang.Object, Android.OS.IParcelable, IDisposable

[<Android.Runtime.Register("android/content/pm/MemoryBudgetInfo", ApiSince=37, DoNotGenerateAcw=true)>]
type MemoryBudgetInfo = class
    inherit Object
    interface IParcelable
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Inheritance

Object

JavaObject

Object

MemoryBudgetInfo

Attributes

RegisterAttribute

Implements

IParcelable IJavaObject IJavaPeerable IDisposable

Remarks

Memory budget information for an application. MemoryBudgetInfo entries are retrieved from <memory-budget> entries in an application's manifest, and can be obtained through PackageManager.getMemoryBudgets.

A MemoryBudgetInfo that is declared in the Android manifest sets a ceiling on the memory available to the package or to a process within the package. MemoryBudgetInfo declarations may appear at the application level and at the process level. The two are independent and neither overrides the other. In practice, however, the smaller budget dominates.

Every MemoryBudgetInfo has a state and a feature; these two attributes determine if and when the MemoryBudgetInfo is applicable.

The state is the operational state of the process or the application, and is one of Foreground, Perceptible, or Background.

The feature selects for device form-factor and is one of Unspecified, TV, Auto, and Watch.

A MemoryBudgetInfo is applicable to a process if its feature is Unspecified or if its feature matches the device's form-factor. A MemoryBudgetInfo applies to a process if it is applicable to the process and the MemoryBudgetInfo state is less than or equal to the operational state of the process. Applications also have state, which is roughly the lowest state of any process running in the application.

A MemoryBudgetInfo declares an upper bound on the amount of memory the process or application may use. The upper bound is computed from three factors:

maxMb is a baseline amount of memory, expressed in MiB. This must be positive.

additionalBytesPerPixel is a scaling factor: bytes per display pixel. This must be non-negative and defaults to zero.

additionalMbPerDensity is a scaling factor: MiB times display density. This must be non-negative and defaults to zero.

The actual limit is calculated as the maxMb value plus the scale factors applied to the default display of the device.

If a process RSS exceeds its declared budget then the kernel will force it to drop memory. This usually means dropping file cache pages but it may also mean that some memory will be moved to swap. In most cases this happens without any impact on the process, but if the process is actively using more memory than the budget limit, the process will slow down as pages are swapped out and then back in. In the limit, the process may ANR.

Android reference for android.content.pm.MemoryBudgetInfo.

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.