BenchmarkState

class BenchmarkState

Control object for benchmarking in the code in Java.

Query a state object with androidx.benchmark.junit4.BenchmarkRule.getState, and use it to measure a block of Java with BenchmarkState.keepRunning:

@Rule
public BenchmarkRule benchmarkRule = new BenchmarkRule();

@Test
public void sampleMethod() {
    BenchmarkState state = benchmarkRule.getState();

    int[] src = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
    while (state.keepRunning()) {
        int[] dest = new int[src.length];
        System.arraycopy(src, 0, dest, 0, src.length);
    }
}
See also
BenchmarkRule

#getState()

Summary

Nested types
@RequiresOptIn
@Retention(value = AnnotationRetention.BINARY)
@Target(allowedTargets = [AnnotationTarget.FUNCTION])
annotation BenchmarkState.Companion.ExperimentalExternalReport

Public companion functions
Unit
@BenchmarkState.Companion.ExperimentalExternalReport
reportData(
    className: String,
    testName: String,
    totalRunTimeNs: @IntRange(from = 0) Long,
    dataNs: List<Long>,
    warmupIterations: @IntRange(from = 0) Int,
    thermalThrottleSleepSeconds: @IntRange(from = 0) Long,
    repeatIterations: @IntRange(from = 1) Int
)

Hooks for benchmarks not using androidx.benchmark.junit4.BenchmarkRule to register results.

Public constructors
@ExperimentalBenchmarkStateApi
BenchmarkState(warmupCount: Int?, repeatCount: Int?)

Create a BenchmarkState for custom measurement behavior.

Public functions
List<Double>
Boolean

Returns true if the benchmark needs more samples - use this as the condition of a while loop.
Unit

Stops the benchmark timer.
Unit

Resumes the benchmark timer.

Public companion functions

reportData

Added in 1.0.0
@BenchmarkState.Companion.ExperimentalExternalReport
fun reportData(
    className: String,
    testName: String,
    totalRunTimeNs: @IntRange(from = 0) Long,
    dataNs: List<Long>,
    warmupIterations: @IntRange(from = 0) Int,
    thermalThrottleSleepSeconds: @IntRange(from = 0) Long,
    repeatIterations: @IntRange(from = 1) Int
): Unit

Hooks for benchmarks not using androidx.benchmark.junit4.BenchmarkRule to register results.

Results are printed to Studio console, and added to the output JSON file.

Parameters
className: String

Name of class the benchmark runs in
testName: String

Name of the benchmark
totalRunTimeNs: @IntRange(from = 0) Long

The total run time of the benchmark
dataNs: List<Long>

List of all measured timing results, in nanoseconds
warmupIterations: @IntRange(from = 0) Int

Number of iterations of warmup before measurements started. Should be no less than 0.
thermalThrottleSleepSeconds: @IntRange(from = 0) Long

Number of seconds benchmark was paused during thermal throttling.
repeatIterations: @IntRange(from = 1) Int

Number of iterations in between each measurement. Should be no less than 1.

Public constructors

BenchmarkState

Added in 1.2.0
@ExperimentalBenchmarkStateApi
BenchmarkState(warmupCount: Int? = null, repeatCount: Int? = null)

Create a BenchmarkState for custom measurement behavior.

Parameters
warmupCount: Int? = null

Number of non-measured warmup iterations to perform, leave null to determine automatically
repeatCount: Int? = null

Number of measurements to perform, leave null for default behavior

Public functions

getMeasurementTimeNs

Added in 1.2.0
@ExperimentalBenchmarkStateApi
fun getMeasurementTimeNs(): List<Double>

keepRunning

Added in 1.0.0
fun keepRunning(): Boolean

Returns true if the benchmark needs more samples - use this as the condition of a while loop.

while (state.keepRunning()) {
    int[] dest = new int[src.length];
    System.arraycopy(src, 0, dest, 0, src.length);
}

pauseTiming

Added in 1.0.0
fun pauseTiming(): Unit

Stops the benchmark timer.

This method can be called only when the timer is running.

@Test
public void bitmapProcessing() {
    final BenchmarkState state = mBenchmarkRule.getState();
    while (state.keepRunning()) {
        state.pauseTiming();
        // disable timing while constructing test input
        Bitmap input = constructTestBitmap();
        state.resumeTiming();

        processBitmap(input);
    }
}
Throws
kotlin.IllegalStateException

if the benchmark is already paused.
See also
resumeTiming

resumeTiming

Added in 1.0.0
fun resumeTiming(): Unit

Resumes the benchmark timer.

This method can be called only when the timer is stopped.

@Test
public void bitmapProcessing() {
    final BenchmarkState state = mBenchmarkRule.getState();
    while (state.keepRunning()) {
        state.pauseTiming();
        // disable timing while constructing test input
        Bitmap input = constructTestBitmap();
        state.resumeTiming();

        processBitmap(input);
    }
}
Throws
kotlin.IllegalStateException

if the benchmark is already running.
See also
pauseTiming