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-life and not created or destroyed dynamically.

Each session is expected to have a periodic workload with a target duration for each cycle. The cycle duration is likely greater than the target work duration to allow other parts of the pipeline to run within the available budget. For example, a renderer thread may work at 60hz in order to produce frames at the display's frame but have a target work duration of only 6ms.

Any call in this class will change its internal data, so you must do your own thread safety to protect from racing.

Note that the target work duration can be updated if workloads change.

After each cycle of work, the client is expected to report the actual time taken to complete.

All timings should be in SystemClock#elapsedRealtimeNanos().

Summary

Public methods
`void`	`close()` Ends the current hint session.
`void`	`reportActualWorkDuration(long actualDurationNanos)` Reports the actual duration for the last cycle of work.
`void`	`setThreads(int[] tids)` Set a list of threads to the performance hint session.
`void`	`updateTargetWorkDuration(long targetDurationNanos)` Updates this session's target 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 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

setThreads

Added in Android UpsideDownCake

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 duration for each cycle of work.

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