PerformanceHintManager.Session

Kotlin |Java

public static class PerformanceHintManager.Session
extends Object implements Closeable

java.lang.Object
↳	android.os.PerformanceHintManager.Session

A Session represents a group of threads with an inter-related workload such that hints for their performance should be considered as a unit. The threads in a given session should be long-lived and not created or destroyed dynamically. The work duration API can be used with periodic workloads to dynamically adjust thread performance and keep the work on schedule while optimizing the available power budget. When using the work duration API, the starting target duration should be specified while creating the session, but can later be adjusted with updateTargetWorkDuration(long). While using the work duration API, the client is be expected to call reportActualWorkDuration(long) each cycle to report the actual time taken to complete to the system. Any call in this class will change its internal data, so you must do your own thread safety to protect from racing. All timings should be in SystemClock.uptimeNanos().

Summary

Public methods
`void`	`close()` Ends the current hint session.
`void`	`reportActualWorkDuration(WorkDuration workDuration)` Reports the work duration for the last cycle of work.
`void`	`reportActualWorkDuration(long actualDurationNanos)` Reports the actual duration for the last cycle of work.
`void`	`setPreferPowerEfficiency(boolean enabled)` This tells the session that these threads can be safely scheduled to prefer power efficiency over performance.
`void`	`setThreads(int[] tids)` Set a list of threads to the performance hint session.
`void`	`updateTargetWorkDuration(long targetDurationNanos)` Updates this session's target total duration for each cycle of work.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          java.io.Closeable


      close()

Closes this stream and releases any system resources associated with it.

From interface


        
          java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Public methods

close

Added in API level 31

public void close ()

Ends the current hint session. Once called, you should not call anything else on this object.

reportActualWorkDuration

Added in API level 35

public void reportActualWorkDuration (WorkDuration workDuration)

Reports the work duration for the last cycle of work. The system will attempt to adjust the core placement of the threads within the thread group and/or the frequency of the core on which they are run to bring the actual duration close to the target duration.

Parameters
`workDuration`	`WorkDuration`: the work duration of each component. This value cannot be `null`.

Throws
`IllegalArgumentException`	if the work period start timestamp or the total duration are less than or equal to zero, if either the actual CPU duration or actual GPU duration is less than zero, or if both the CPU and GPU durations are zero.

reportActualWorkDuration

Added in API level 31

public void reportActualWorkDuration (long actualDurationNanos)

Reports the actual duration for the last cycle of work. The system will attempt to adjust the core placement of the threads within the thread group and/or the frequency of the core on which they are run to bring the actual duration close to the target duration.

Parameters
`actualDurationNanos`	`long`: how long the thread group took to complete its last task in nanoseconds

setPreferPowerEfficiency

Added in API level 35

public void setPreferPowerEfficiency (boolean enabled)

This tells the session that these threads can be safely scheduled to prefer power efficiency over performance.

Parameters
`enabled`	`boolean`: The flag that sets whether this session uses power-efficient scheduling.

setThreads

Added in API level 34

public void setThreads (int[] tids)

Set a list of threads to the performance hint session. This operation will replace the current list of threads with the given list of threads. Note that this is not an oneway method.

Parameters
`tids`	`int`: The list of threads to be associated with this session. They must be part of this app's thread group This value cannot be `null`.

Throws
`IllegalStateException`	if the hint session is not in the foreground
`IllegalArgumentException`	if the thread id list is empty
`SecurityException`	if any thread id doesn't belong to the application

updateTargetWorkDuration

Added in API level 31

public void updateTargetWorkDuration (long targetDurationNanos)

Updates this session's target total duration for each cycle of work.

Parameters
`targetDurationNanos`	`long`: the new desired duration in nanoseconds