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Commit 293b4b3a authored by Dmitri Plotnikov's avatar Dmitri Plotnikov
Browse files

Add random noise to power monitor readings 

Bug: 273310268
Test: atest FrameworksServicesTests:PowerStatsServiceTest
Change-Id: I12127999edcff0609fbccee4db91de86ff338838
parent 1ea5f812

services/core/java/com/android/server/powerstats/PowerStatsService.java

+48 −6
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ import android.hardware.power.stats.EnergyConsumerType; 
import android.hardware.power.stats.EnergyMeasurement;

import android.hardware.power.stats.PowerEntity;

import android.hardware.power.stats.StateResidencyResult;

import android.os.Binder;

import android.os.Bundle;

import android.os.Environment;

import android.os.Handler;
@@ -41,6 +42,7 @@ import android.os.UserHandle; 
import android.power.PowerStatsInternal;

import android.provider.DeviceConfig;

import android.provider.DeviceConfigInterface;

import android.util.Log;

import android.util.Slog;



import com.android.internal.annotations.GuardedBy;
@@ -58,6 +60,7 @@ import java.io.FileDescriptor; 
import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.List;

import java.util.Locale;

import java.util.concurrent.CompletableFuture;

import java.util.concurrent.Executor;
@@ -82,6 +85,11 @@ public class PowerStatsService extends SystemService { 


    static final String KEY_POWER_MONITOR_API_ENABLED = "power_monitor_api_enabled";



    // The alpha parameter of the Beta distribution used by the random noise generator.

    // The higher this value, the smaller the amount of added noise.

    private static final double INTERVAL_RANDOM_NOISE_GENERATION_ALPHA = 50;

    private static final long MAX_RANDOM_NOISE_UWS = 10_000_000;



    private final Injector mInjector;

    private final Clock mClock;

    private final DeviceConfigInterface mDeviceConfig;
@@ -189,6 +197,10 @@ public class PowerStatsService extends SystemService { 
        DeviceConfigInterface getDeviceConfig() {

            return DeviceConfigInterface.REAL;

        }



        IntervalRandomNoiseGenerator createIntervalRandomNoiseGenerator() {

            return new IntervalRandomNoiseGenerator(INTERVAL_RANDOM_NOISE_GENERATION_ALPHA);

        }

    }



    private final IBinder mService = new IPowerStatsService.Stub() {
@@ -200,7 +212,9 @@ public class PowerStatsService extends SystemService { 


        @Override

        public void getPowerMonitorReadings(int[] powerMonitorIds, ResultReceiver resultReceiver) {

            getHandler().post(() -> getPowerMonitorReadingsImpl(powerMonitorIds, resultReceiver));

            int callingUid = Binder.getCallingUid();

            getHandler().post(() ->

                    getPowerMonitorReadingsImpl(powerMonitorIds, resultReceiver, callingUid));

        }



        @Override
@@ -493,6 +507,7 @@ public class PowerStatsService extends SystemService { 
        public final int id;

        public long timestampMs;

        public long energyUws = PowerMonitorReadings.ENERGY_UNAVAILABLE;

        public long prevEnergyUws;



        private PowerMonitorState(PowerMonitor powerMonitor, int id) {

            this.powerMonitor = powerMonitor;
@@ -502,7 +517,8 @@ public class PowerStatsService extends SystemService { 


    private boolean mPowerMonitorApiEnabled = true;

    private volatile PowerMonitor[] mPowerMonitors;

    private volatile PowerMonitorState[] mPowerMonitorStates;

    private PowerMonitorState[] mPowerMonitorStates;

    private IntervalRandomNoiseGenerator mIntervalRandomNoiseGenerator;



    private void setPowerMonitorApiEnabled(boolean powerMonitorApiEnabled) {

        if (powerMonitorApiEnabled != mPowerMonitorApiEnabled) {
@@ -522,6 +538,10 @@ public class PowerStatsService extends SystemService { 
                return;

            }



            if (mIntervalRandomNoiseGenerator == null) {

                mIntervalRandomNoiseGenerator = mInjector.createIntervalRandomNoiseGenerator();

            }



            if (!mPowerMonitorApiEnabled) {

                mPowerMonitors = new PowerMonitor[0];

                mPowerMonitorStates = new PowerMonitorState[0];
@@ -621,7 +641,7 @@ public class PowerStatsService extends SystemService { 
     */

    @VisibleForTesting

    public void getPowerMonitorReadingsImpl(@NonNull int[] powerMonitorIndices,

            ResultReceiver resultReceiver) {

            ResultReceiver resultReceiver, int callingUid) {

        ensurePowerMonitors();



        long earliestTimestamp = Long.MAX_VALUE;
@@ -644,15 +664,35 @@ public class PowerStatsService extends SystemService { 
                || mClock.elapsedRealtime() - earliestTimestamp > MAX_POWER_MONITOR_AGE_MILLIS) {

            updateEnergyConsumers(powerMonitorStates);

            updateEnergyMeasurements(powerMonitorStates);

            mIntervalRandomNoiseGenerator.refresh();

        }



        long[] energy = new long[powerMonitorStates.length];

        long[] timestamps = new long[powerMonitorStates.length];

        for (int i = 0; i < powerMonitorStates.length; i++) {

            PowerMonitorState state = powerMonitorStates[i];



            // TODO(273310268): add random noise

            if (state.energyUws != PowerMonitorReadings.ENERGY_UNAVAILABLE

                    && state.prevEnergyUws != PowerMonitorReadings.ENERGY_UNAVAILABLE) {

                energy[i] = mIntervalRandomNoiseGenerator.addNoise(

                        Math.max(state.prevEnergyUws, state.energyUws - MAX_RANDOM_NOISE_UWS),

                        state.energyUws, callingUid);

                if (DEBUG) {

                    Log.d(TAG, String.format(Locale.ENGLISH,

                            "Monitor=%s timestamp=%d energy=%d"

                                    + " uid=%d noise=%.1f%% returned=%d",

                            state.powerMonitor.name,

                            state.timestampMs,

                            state.energyUws,

                            callingUid,

                            state.energyUws != state.prevEnergyUws

                                    ? (state.energyUws - energy[i]) * 100.0

                                            / (state.energyUws - state.prevEnergyUws)

                                    : 0,

                            energy[i]));

                }

            } else {

                energy[i] = state.energyUws;

            }

            timestamps[i] = state.timestampMs;

        }
@@ -678,6 +718,7 @@ public class PowerStatsService extends SystemService { 
                    == PowerMonitor.POWER_MONITOR_TYPE_CONSUMER) {

                for (EnergyConsumerResult energyConsumerResult : energyConsumerResults) {

                    if (energyConsumerResult.id == powerMonitorState.id) {

                        powerMonitorState.prevEnergyUws = powerMonitorState.energyUws;

                        powerMonitorState.energyUws = energyConsumerResult.energyUWs;

                        powerMonitorState.timestampMs = energyConsumerResult.timestampMs;

                        break;
@@ -703,6 +744,7 @@ public class PowerStatsService extends SystemService { 
                    == PowerMonitor.POWER_MONITOR_TYPE_MEASUREMENT) {

                for (EnergyMeasurement energyMeasurement : energyMeasurements) {

                    if (energyMeasurement.id == powerMonitorState.id) {

                        powerMonitorState.prevEnergyUws = powerMonitorState.energyUws;

                        powerMonitorState.energyUws = energyMeasurement.energyUWs;

                        powerMonitorState.timestampMs = energyMeasurement.timestampMs;

                        break;

services/tests/servicestests/src/com/android/server/powerstats/PowerStatsServiceTest.java

+14 −5
Original line number Diff line number Diff line
@@ -99,6 +99,7 @@ public class PowerStatsServiceTest { 
    private static final int POWER_ENTITY_COUNT = 3;

    private static final int STATE_INFO_COUNT = 5;

    private static final int STATE_RESIDENCY_COUNT = 4;

    private static final int APP_UID = 10042;



    private final Context mContext = InstrumentationRegistry.getInstrumentation().getContext();

    private PowerStatsService mService;
@@ -109,6 +110,7 @@ public class PowerStatsServiceTest { 
    private PowerStatsLogger mPowerStatsLogger;

    private MockClock mMockClock = new MockClock();

    private DeviceConfigInterface mMockDeviceConfig = new FakeDeviceConfigInterface();

    private IntervalRandomNoiseGenerator mMockNoiseGenerator = new IntervalRandomNoiseGenerator(42);



    private class MockClock extends Clock {

        public long realtime;
@@ -205,6 +207,11 @@ public class PowerStatsServiceTest { 
        DeviceConfigInterface getDeviceConfig() {

            return mMockDeviceConfig;

        }



        @Override

        IntervalRandomNoiseGenerator createIntervalRandomNoiseGenerator() {

            return mMockNoiseGenerator;

        }

    };



    public static final class TestPowerStatsHALWrapper implements IPowerStatsHALWrapper {
@@ -1102,6 +1109,7 @@ public class PowerStatsServiceTest { 
    @Test

    public void getPowerMonitors() {

        mMockClock.realtime = 10 * 60_000;

        mMockNoiseGenerator.reseed(314);



        mPowerStatsHALWrapper.buildEnergyConsumerResult();

        EnergyConsumerResult[] energyConsumerResults = mPowerStatsHALWrapper.energyConsumerResults;
@@ -1131,7 +1139,7 @@ public class PowerStatsServiceTest { 
        GetPowerMonitorsResult result = new GetPowerMonitorsResult();

        mService.getPowerMonitorReadingsImpl(

                new int[]{consumer1.index, consumer2.index, measurement1.index,

                        measurement2.index}, result);

                        measurement2.index}, result, APP_UID);



        assertThat(result.energyUws).isEqualTo(new long[]{42, 142, 314, 514});

        assertThat(result.timestamps).isEqualTo(new long[]{600_000, 600_100, 600_000, 600_200});
@@ -1150,7 +1158,7 @@ public class PowerStatsServiceTest { 
        }



        mService.getPowerMonitorReadingsImpl(new int[]{consumer1.index, measurement1.index},

                result);

                result, APP_UID);



        assertThat(result.energyUws).isEqualTo(new long[]{42, 314});

        assertThat(result.timestamps).isEqualTo(new long[]{600_000, 600_000});
@@ -1158,9 +1166,10 @@ public class PowerStatsServiceTest { 
        mMockClock.realtime += 10 * 60000;



        mService.getPowerMonitorReadingsImpl(new int[]{consumer1.index, measurement1.index},

                result);

                result, APP_UID);



        assertThat(result.energyUws).isEqualTo(new long[]{300, 400});

        // This time, random noise is added

        assertThat(result.energyUws).isEqualTo(new long[]{298, 399});

        assertThat(result.timestamps).isEqualTo(new long[]{600_301, 600_401});

    }
@@ -1178,7 +1187,7 @@ public class PowerStatsServiceTest { 
        assertThat(supportedPowerMonitorsResult.powerMonitors).isEmpty();



        GetPowerMonitorsResult getPowerMonitorsResult = new GetPowerMonitorsResult();

        mService.getPowerMonitorReadingsImpl(new int[]{0}, getPowerMonitorsResult);

        mService.getPowerMonitorReadingsImpl(new int[]{0}, getPowerMonitorsResult, APP_UID);

        assertThat(getPowerMonitorsResult.resultCode).isEqualTo(

                IPowerStatsService.RESULT_UNSUPPORTED_POWER_MONITOR);