[hbm] Separate HBM times for multi-display devices.

This change separates High brightness mode information
for different physical displays, which was currently being shared
causing both displays to show similar HBM time remaining.
Each display's OLED lifetime risk due to HBM is independent,
so each display's HBM for SV timer should be independent.

Bug: 254588984

Test: atest com.android.server.display.HbmEventTest
      atest com.android.server.display.HighBrightnessModeControllerTest
      atest com.android.server.display.HighBrightnessModeMetadataTest
      atest com.android.server.display.DisplayPowerControllerTest
      atest com.android.server.display.DisplayPowerControllerTest2

      Manual testing:
      Manually tested this fix on multiple display devices, with high lux and
      forcing displays into HBM mode, and changing the
      displays to see if the time events are being updated correctly.

      $ adb shell dumpsys display | grep -i remainingtime
      remainingTime=274576
      remainingTime=249182

Change-Id: I0ed4ad99108a1a850dae68e1f6cf92adfab8bc1d

services/core/java/com/android/server/display/DisplayManagerService.java

@@ -108,6 +108,7 @@ import android.os.UserManager;
 import android.provider.DeviceConfig;
 import android.provider.Settings;
 import android.text.TextUtils;
+import android.util.ArrayMap;
 import android.util.ArraySet;
 import android.util.EventLog;
 import android.util.IntArray;
@@ -259,6 +260,13 @@ public final class DisplayManagerService extends SystemService {
     final SparseArray<Pair<IVirtualDevice, DisplayWindowPolicyController>>
             mDisplayWindowPolicyControllers = new SparseArray<>();
 
+    /**
+     *  Map of every internal primary display device {@link HighBrightnessModeMetadata}s indexed by
+     *  {@link DisplayDevice#mUniqueId}.
+     */
+    public final ArrayMap<String, HighBrightnessModeMetadata> mHighBrightnessModeMetadataMap =
+            new ArrayMap<>();
+
     // List of all currently registered display adapters.
     private final ArrayList<DisplayAdapter> mDisplayAdapters = new ArrayList<DisplayAdapter>();
 
@@ -1634,7 +1642,16 @@ public final class DisplayManagerService extends SystemService {
 
         DisplayPowerControllerInterface dpc = mDisplayPowerControllers.get(displayId);
         if (dpc != null) {
-            dpc.onDisplayChanged();
+            final DisplayDevice device = display.getPrimaryDisplayDeviceLocked();
+            if (device == null) {
+                Slog.wtf(TAG, "Display Device is null in DisplayManagerService for display: "
+                        + display.getDisplayIdLocked());
+                return;
+            }
+
+            final String uniqueId = device.getUniqueId();
+            HighBrightnessModeMetadata hbmMetadata = mHighBrightnessModeMetadataMap.get(uniqueId);
+            dpc.onDisplayChanged(hbmMetadata);
         }
     }
 
@@ -1692,7 +1709,15 @@ public final class DisplayManagerService extends SystemService {
         final int displayId = display.getDisplayIdLocked();
         final DisplayPowerControllerInterface dpc = mDisplayPowerControllers.get(displayId);
         if (dpc != null) {
-            dpc.onDisplayChanged();
+            final DisplayDevice device = display.getPrimaryDisplayDeviceLocked();
+            if (device == null) {
+                Slog.wtf(TAG, "Display Device is null in DisplayManagerService for display: "
+                        + display.getDisplayIdLocked());
+                return;
+            }
+            final String uniqueId = device.getUniqueId();
+            HighBrightnessModeMetadata hbmMetadata = mHighBrightnessModeMetadataMap.get(uniqueId);
+            dpc.onDisplayChanged(hbmMetadata);
         }
     }
 
@@ -2645,6 +2670,31 @@ public final class DisplayManagerService extends SystemService {
         mLogicalDisplayMapper.forEachLocked(this::addDisplayPowerControllerLocked);
     }
 
+    private HighBrightnessModeMetadata getHighBrightnessModeMetadata(LogicalDisplay display) {
+        final DisplayDevice device = display.getPrimaryDisplayDeviceLocked();
+        if (device == null) {
+            Slog.wtf(TAG, "Display Device is null in DisplayPowerController for display: "
+                    + display.getDisplayIdLocked());
+            return null;
+        }
+
+        // HBM brightness mode is only applicable to internal physical displays.
+        if (display.getDisplayInfoLocked().type != Display.TYPE_INTERNAL) {
+            return null;
+        }
+
+        final String uniqueId = device.getUniqueId();
+
+        if (mHighBrightnessModeMetadataMap.containsKey(uniqueId)) {
+            return mHighBrightnessModeMetadataMap.get(uniqueId);
+        }
+
+        // HBM Time info not present. Create a new one for this physical display.
+        HighBrightnessModeMetadata hbmInfo = new HighBrightnessModeMetadata();
+        mHighBrightnessModeMetadataMap.put(uniqueId, hbmInfo);
+        return hbmInfo;
+    }
+
     @RequiresPermission(Manifest.permission.READ_DEVICE_CONFIG)
     private void addDisplayPowerControllerLocked(LogicalDisplay display) {
         if (mPowerHandler == null) {
@@ -2660,17 +2710,23 @@ public final class DisplayManagerService extends SystemService {
                 display, mSyncRoot);
         final DisplayPowerControllerInterface displayPowerController;
 
+        // If display is internal and has a HighBrightnessModeMetadata mapping, use that.
+        // Or create a new one and use that.
+        // We also need to pass a mapping of the HighBrightnessModeTimeInfoMap to
+        // displayPowerController, so the hbm info can be correctly associated
+        // with the corresponding displaydevice.
+        HighBrightnessModeMetadata hbmMetadata = getHighBrightnessModeMetadata(display);
         if (DeviceConfig.getBoolean("display_manager",
                 "use_newly_structured_display_power_controller", true)) {
             displayPowerController = new DisplayPowerController2(
                     mContext, /* injector= */ null, mDisplayPowerCallbacks, mPowerHandler,
                     mSensorManager, mDisplayBlanker, display, mBrightnessTracker, brightnessSetting,
-                    () -> handleBrightnessChange(display));
+                    () -> handleBrightnessChange(display), hbmMetadata);
         } else {
             displayPowerController = new DisplayPowerController(
                     mContext, /* injector= */ null, mDisplayPowerCallbacks, mPowerHandler,
                     mSensorManager, mDisplayBlanker, display, mBrightnessTracker, brightnessSetting,
-                    () -> handleBrightnessChange(display));
+                    () -> handleBrightnessChange(display), hbmMetadata);
         }
         mDisplayPowerControllers.append(display.getDisplayIdLocked(), displayPowerController);
     }

services/core/java/com/android/server/display/DisplayPowerController.java

@@ -388,6 +388,7 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
     private float[] mNitsRange;
 
     private final HighBrightnessModeController mHbmController;
+    private final HighBrightnessModeMetadata mHighBrightnessModeMetadata;
 
     private final BrightnessThrottler mBrightnessThrottler;
 
@@ -505,13 +506,14 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
             DisplayPowerCallbacks callbacks, Handler handler,
             SensorManager sensorManager, DisplayBlanker blanker, LogicalDisplay logicalDisplay,
             BrightnessTracker brightnessTracker, BrightnessSetting brightnessSetting,
-            Runnable onBrightnessChangeRunnable) {
+            Runnable onBrightnessChangeRunnable, HighBrightnessModeMetadata hbmMetadata) {
 
         mInjector = injector != null ? injector : new Injector();
         mClock = mInjector.getClock();
         mLogicalDisplay = logicalDisplay;
         mDisplayId = mLogicalDisplay.getDisplayIdLocked();
         mTag = "DisplayPowerController[" + mDisplayId + "]";
+        mHighBrightnessModeMetadata = hbmMetadata;
         mSuspendBlockerIdUnfinishedBusiness = getSuspendBlockerUnfinishedBusinessId(mDisplayId);
         mSuspendBlockerIdOnStateChanged = getSuspendBlockerOnStateChangedId(mDisplayId);
         mSuspendBlockerIdProxPositive = getSuspendBlockerProxPositiveId(mDisplayId);
@@ -790,7 +792,7 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
      * Make sure DisplayManagerService.mSyncRoot is held when this is called
      */
     @Override
-    public void onDisplayChanged() {
+    public void onDisplayChanged(HighBrightnessModeMetadata hbmMetadata) {
         final DisplayDevice device = mLogicalDisplay.getPrimaryDisplayDeviceLocked();
         if (device == null) {
             Slog.wtf(mTag, "Display Device is null in DisplayPowerController for display: "
@@ -812,7 +814,7 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
                 mUniqueDisplayId = uniqueId;
                 mDisplayStatsId = mUniqueDisplayId.hashCode();
                 mDisplayDeviceConfig = config;
-                loadFromDisplayDeviceConfig(token, info);
+                loadFromDisplayDeviceConfig(token, info, hbmMetadata);
 
                 // Since the underlying display-device changed, we really don't know the
                 // last command that was sent to change it's state. Lets assume it is off and we
@@ -864,7 +866,8 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
         }
     }
 
-    private void loadFromDisplayDeviceConfig(IBinder token, DisplayDeviceInfo info) {
+    private void loadFromDisplayDeviceConfig(IBinder token, DisplayDeviceInfo info,
+                                             HighBrightnessModeMetadata hbmMetadata) {
         // All properties that depend on the associated DisplayDevice and the DDC must be
         // updated here.
         loadBrightnessRampRates();
@@ -877,6 +880,7 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
                     mBrightnessRampIncreaseMaxTimeMillis,
                     mBrightnessRampDecreaseMaxTimeMillis);
         }
+        mHbmController.setHighBrightnessModeMetadata(hbmMetadata);
         mHbmController.resetHbmData(info.width, info.height, token, info.uniqueId,
                 mDisplayDeviceConfig.getHighBrightnessModeData(),
                 new HighBrightnessModeController.HdrBrightnessDeviceConfig() {
@@ -1961,7 +1965,7 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
                     if (mAutomaticBrightnessController != null) {
                         mAutomaticBrightnessController.update();
                     }
-                }, mContext);
+                }, mHighBrightnessModeMetadata, mContext);
     }
 
     private BrightnessThrottler createBrightnessThrottlerLocked() {

services/core/java/com/android/server/display/DisplayPowerController2.java

@@ -328,6 +328,7 @@ final class DisplayPowerController2 implements AutomaticBrightnessController.Cal
     private float[] mNitsRange;
 
     private final HighBrightnessModeController mHbmController;
+    private final HighBrightnessModeMetadata mHighBrightnessModeMetadata;
 
     private final BrightnessThrottler mBrightnessThrottler;
 
@@ -432,7 +433,7 @@ final class DisplayPowerController2 implements AutomaticBrightnessController.Cal
             DisplayPowerCallbacks callbacks, Handler handler,
             SensorManager sensorManager, DisplayBlanker blanker, LogicalDisplay logicalDisplay,
             BrightnessTracker brightnessTracker, BrightnessSetting brightnessSetting,
-            Runnable onBrightnessChangeRunnable) {
+            Runnable onBrightnessChangeRunnable, HighBrightnessModeMetadata hbmMetadata) {
 
         mInjector = injector != null ? injector : new Injector();
         mClock = mInjector.getClock();
@@ -448,6 +449,7 @@ final class DisplayPowerController2 implements AutomaticBrightnessController.Cal
         mDisplayPowerProximityStateController = mInjector.getDisplayPowerProximityStateController(
                 mWakelockController, mDisplayDeviceConfig, mHandler.getLooper(),
                 () -> updatePowerState(), mDisplayId, mSensorManager);
+        mHighBrightnessModeMetadata = hbmMetadata;
         mDisplayStateController = new DisplayStateController(mDisplayPowerProximityStateController);
         mTag = "DisplayPowerController2[" + mDisplayId + "]";
 
@@ -707,7 +709,7 @@ final class DisplayPowerController2 implements AutomaticBrightnessController.Cal
      * Make sure DisplayManagerService.mSyncRoot lock is held when this is called
      */
     @Override
-    public void onDisplayChanged() {
+    public void onDisplayChanged(HighBrightnessModeMetadata hbmMetadata) {
         final DisplayDevice device = mLogicalDisplay.getPrimaryDisplayDeviceLocked();
         if (device == null) {
             Slog.wtf(mTag, "Display Device is null in DisplayPowerController2 for display: "
@@ -721,6 +723,7 @@ final class DisplayPowerController2 implements AutomaticBrightnessController.Cal
         final DisplayDeviceInfo info = device.getDisplayDeviceInfoLocked();
         final boolean isEnabled = mLogicalDisplay.isEnabledLocked();
         final boolean isInTransition = mLogicalDisplay.isInTransitionLocked();
+
         mHandler.post(() -> {
             boolean changed = false;
             if (mDisplayDevice != device) {
@@ -729,7 +732,7 @@ final class DisplayPowerController2 implements AutomaticBrightnessController.Cal
                 mUniqueDisplayId = uniqueId;
                 mDisplayStatsId = mUniqueDisplayId.hashCode();
                 mDisplayDeviceConfig = config;
-                loadFromDisplayDeviceConfig(token, info);
+                loadFromDisplayDeviceConfig(token, info, hbmMetadata);
                 mDisplayPowerProximityStateController.notifyDisplayDeviceChanged(config);
 
                 // Since the underlying display-device changed, we really don't know the
@@ -778,7 +781,8 @@ final class DisplayPowerController2 implements AutomaticBrightnessController.Cal
         }
     }
 
-    private void loadFromDisplayDeviceConfig(IBinder token, DisplayDeviceInfo info) {
+    private void loadFromDisplayDeviceConfig(IBinder token, DisplayDeviceInfo info,
+                                             HighBrightnessModeMetadata hbmMetadata) {
         // All properties that depend on the associated DisplayDevice and the DDC must be
         // updated here.
         loadBrightnessRampRates();
@@ -790,6 +794,7 @@ final class DisplayPowerController2 implements AutomaticBrightnessController.Cal
                     mBrightnessRampIncreaseMaxTimeMillis,
                     mBrightnessRampDecreaseMaxTimeMillis);
         }
+        mHbmController.setHighBrightnessModeMetadata(hbmMetadata);
         mHbmController.resetHbmData(info.width, info.height, token, info.uniqueId,
                 mDisplayDeviceConfig.getHighBrightnessModeData(),
                 new HighBrightnessModeController.HdrBrightnessDeviceConfig() {
@@ -1740,7 +1745,7 @@ final class DisplayPowerController2 implements AutomaticBrightnessController.Cal
                     if (mAutomaticBrightnessController != null) {
                         mAutomaticBrightnessController.update();
                     }
-                }, mContext);
+                }, mHighBrightnessModeMetadata, mContext);
     }
 
     private BrightnessThrottler createBrightnessThrottlerLocked() {

services/core/java/com/android/server/display/DisplayPowerControllerInterface.java

@@ -31,10 +31,14 @@ import java.io.PrintWriter;
 public interface DisplayPowerControllerInterface {
 
     /**
-     * Notified when the display is changed. We use this to apply any changes that might be needed
+     * Notified when the display is changed.
+     * We use this to apply any changes that might be needed
      * when displays get swapped on foldable devices.
+     * We also pass the High brightness mode metadata like
+     * remaining time and hbm events for the corresponding
+     * physical display, to update the values correctly.
      */
-    void onDisplayChanged();
+    void onDisplayChanged(HighBrightnessModeMetadata hbmInfo);
 
     /**
      * Unregisters all listeners and interrupts all running threads; halting future work.

services/core/java/com/android/server/display/HbmEvent.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.display;
+
+
+/**
+ * Represents an event in which High Brightness Mode was enabled.
+ */
+class HbmEvent {
+    private long mStartTimeMillis;
+    private long mEndTimeMillis;
+
+    HbmEvent(long startTimeMillis, long endTimeMillis) {
+        this.mStartTimeMillis = startTimeMillis;
+        this.mEndTimeMillis = endTimeMillis;
+    }
+
+    public long getStartTimeMillis() {
+        return mStartTimeMillis;
+    }
+
+    public long getEndTimeMillis() {
+        return mEndTimeMillis;
+    }
+
+    @Override
+    public String toString() {
+        return "HbmEvent: {startTimeMillis:" + mStartTimeMillis + ", endTimeMillis: "
+                + mEndTimeMillis + "}, total: "
+                + ((mEndTimeMillis - mStartTimeMillis) / 1000) + "]";
+    }
+}

services/core/java/com/android/server/display/HighBrightnessModeController.java

@@ -105,30 +105,23 @@ class HighBrightnessModeController {
     private int mHbmStatsState = FrameworkStatsLog.DISPLAY_HBM_STATE_CHANGED__STATE__HBM_OFF;
 
     /**
-     * If HBM is currently running, this is the start time for the current HBM session.
+     * If HBM is currently running, this is the start time and set of all events,
+     * for the current HBM session.
      */
-    private long mRunningStartTimeMillis = -1;
+    private HighBrightnessModeMetadata mHighBrightnessModeMetadata = null;
-
-    /**
-     * Queue of previous HBM-events ordered from most recent to least recent.
-     * Meant to store only the events that fall into the most recent
-     * {@link HighBrightnessModeData#timeWindowMillis mHbmData.timeWindowMillis}.
-     */
-    private final ArrayDeque<HbmEvent> mEvents = new ArrayDeque<>();
-
     HighBrightnessModeController(Handler handler, int width, int height, IBinder displayToken,
             String displayUniqueId, float brightnessMin, float brightnessMax,
             HighBrightnessModeData hbmData, HdrBrightnessDeviceConfig hdrBrightnessCfg,
-            Runnable hbmChangeCallback, Context context) {
+            Runnable hbmChangeCallback, HighBrightnessModeMetadata hbmMetadata, Context context) {
         this(new Injector(), handler, width, height, displayToken, displayUniqueId, brightnessMin,
-            brightnessMax, hbmData, hdrBrightnessCfg, hbmChangeCallback, context);
+            brightnessMax, hbmData, hdrBrightnessCfg, hbmChangeCallback, hbmMetadata, context);
     }
 
     @VisibleForTesting
     HighBrightnessModeController(Injector injector, Handler handler, int width, int height,
             IBinder displayToken, String displayUniqueId, float brightnessMin, float brightnessMax,
             HighBrightnessModeData hbmData, HdrBrightnessDeviceConfig hdrBrightnessCfg,
-            Runnable hbmChangeCallback, Context context) {
+            Runnable hbmChangeCallback, HighBrightnessModeMetadata hbmMetadata, Context context) {
         mInjector = injector;
         mContext = context;
         mClock = injector.getClock();
@@ -137,6 +130,7 @@ class HighBrightnessModeController {
         mBrightnessMin = brightnessMin;
         mBrightnessMax = brightnessMax;
         mHbmChangeCallback = hbmChangeCallback;
+        mHighBrightnessModeMetadata = hbmMetadata;
         mSkinThermalStatusObserver = new SkinThermalStatusObserver(mInjector, mHandler);
         mSettingsObserver = new SettingsObserver(mHandler);
         mRecalcRunnable = this::recalculateTimeAllowance;
@@ -222,19 +216,22 @@ class HighBrightnessModeController {
 
         // If we are starting or ending a high brightness mode session, store the current
         // session in mRunningStartTimeMillis, or the old one in mEvents.
-        final boolean wasHbmDrainingAvailableTime = mRunningStartTimeMillis != -1;
+        final long runningStartTime = mHighBrightnessModeMetadata.getRunningStartTimeMillis();
+        final boolean wasHbmDrainingAvailableTime = runningStartTime != -1;
         final boolean shouldHbmDrainAvailableTime = mBrightness > mHbmData.transitionPoint
                 && !mIsHdrLayerPresent;
         if (wasHbmDrainingAvailableTime != shouldHbmDrainAvailableTime) {
             final long currentTime = mClock.uptimeMillis();
             if (shouldHbmDrainAvailableTime) {
-                mRunningStartTimeMillis = currentTime;
+                mHighBrightnessModeMetadata.setRunningStartTimeMillis(currentTime);
             } else {
-                mEvents.addFirst(new HbmEvent(mRunningStartTimeMillis, currentTime));
+                final HbmEvent hbmEvent = new HbmEvent(runningStartTime, currentTime);
-                mRunningStartTimeMillis = -1;
+                mHighBrightnessModeMetadata.addHbmEvent(hbmEvent);
+                mHighBrightnessModeMetadata.setRunningStartTimeMillis(-1);
 
                 if (DEBUG) {
-                    Slog.d(TAG, "New HBM event: " + mEvents.peekFirst());
+                    Slog.d(TAG, "New HBM event: "
+                            + mHighBrightnessModeMetadata.getHbmEventQueue().peekFirst());
                 }
             }
         }
@@ -260,6 +257,10 @@ class HighBrightnessModeController {
         mSettingsObserver.stopObserving();
     }
 
+    void setHighBrightnessModeMetadata(HighBrightnessModeMetadata hbmInfo) {
+        mHighBrightnessModeMetadata = hbmInfo;
+    }
+
     void resetHbmData(int width, int height, IBinder displayToken, String displayUniqueId,
             HighBrightnessModeData hbmData, HdrBrightnessDeviceConfig hdrBrightnessCfg) {
         mWidth = width;
@@ -316,20 +317,22 @@ class HighBrightnessModeController {
         pw.println("  mBrightnessMax=" + mBrightnessMax);
         pw.println("  remainingTime=" + calculateRemainingTime(mClock.uptimeMillis()));
         pw.println("  mIsTimeAvailable= " + mIsTimeAvailable);
-        pw.println("  mRunningStartTimeMillis=" + TimeUtils.formatUptime(mRunningStartTimeMillis));
+        pw.println("  mRunningStartTimeMillis="
+                + TimeUtils.formatUptime(mHighBrightnessModeMetadata.getRunningStartTimeMillis()));
         pw.println("  mIsThermalStatusWithinLimit=" + mIsThermalStatusWithinLimit);
         pw.println("  mIsBlockedByLowPowerMode=" + mIsBlockedByLowPowerMode);
         pw.println("  width*height=" + mWidth + "*" + mHeight);
         pw.println("  mEvents=");
         final long currentTime = mClock.uptimeMillis();
         long lastStartTime = currentTime;
-        if (mRunningStartTimeMillis != -1) {
+        long runningStartTimeMillis = mHighBrightnessModeMetadata.getRunningStartTimeMillis();
-            lastStartTime = dumpHbmEvent(pw, new HbmEvent(mRunningStartTimeMillis, currentTime));
+        if (runningStartTimeMillis != -1) {
+            lastStartTime = dumpHbmEvent(pw, new HbmEvent(runningStartTimeMillis, currentTime));
         }
-        for (HbmEvent event : mEvents) {
+        for (HbmEvent event : mHighBrightnessModeMetadata.getHbmEventQueue()) {
-            if (lastStartTime > event.endTimeMillis) {
+            if (lastStartTime > event.getEndTimeMillis()) {
                 pw.println("    event: [normal brightness]: "
-                        + TimeUtils.formatDuration(lastStartTime - event.endTimeMillis));
+                        + TimeUtils.formatDuration(lastStartTime - event.getEndTimeMillis()));
             }
             lastStartTime = dumpHbmEvent(pw, event);
         }
@@ -338,12 +341,12 @@ class HighBrightnessModeController {
     }
 
     private long dumpHbmEvent(PrintWriter pw, HbmEvent event) {
-        final long duration = event.endTimeMillis - event.startTimeMillis;
+        final long duration = event.getEndTimeMillis() - event.getStartTimeMillis();
         pw.println("    event: ["
-                + TimeUtils.formatUptime(event.startTimeMillis) + ", "
+                + TimeUtils.formatUptime(event.getStartTimeMillis()) + ", "
-                + TimeUtils.formatUptime(event.endTimeMillis) + "] ("
+                + TimeUtils.formatUptime(event.getEndTimeMillis()) + "] ("
                 + TimeUtils.formatDuration(duration) + ")");
-        return event.startTimeMillis;
+        return event.getStartTimeMillis();
     }
 
     private boolean isCurrentlyAllowed() {
@@ -372,13 +375,15 @@ class HighBrightnessModeController {
 
         // First, lets see how much time we've taken for any currently running
         // session of HBM.
-        if (mRunningStartTimeMillis > 0) {
+        long runningStartTimeMillis = mHighBrightnessModeMetadata.getRunningStartTimeMillis();
-            if (mRunningStartTimeMillis > currentTime) {
+        if (runningStartTimeMillis > 0) {
+            if (runningStartTimeMillis > currentTime) {
                 Slog.e(TAG, "Start time set to the future. curr: " + currentTime
-                        + ", start: " + mRunningStartTimeMillis);
+                        + ", start: " + runningStartTimeMillis);
-                mRunningStartTimeMillis = currentTime;
+                mHighBrightnessModeMetadata.setRunningStartTimeMillis(currentTime);
+                runningStartTimeMillis = currentTime;
             }
-            timeAlreadyUsed = currentTime - mRunningStartTimeMillis;
+            timeAlreadyUsed = currentTime - runningStartTimeMillis;
         }
 
         if (DEBUG) {
@@ -387,18 +392,19 @@ class HighBrightnessModeController {
 
         // Next, lets iterate through the history of previous sessions and add those times.
         final long windowstartTimeMillis = currentTime - mHbmData.timeWindowMillis;
-        Iterator<HbmEvent> it = mEvents.iterator();
+        Iterator<HbmEvent> it = mHighBrightnessModeMetadata.getHbmEventQueue().iterator();
         while (it.hasNext()) {
             final HbmEvent event = it.next();
 
             // If this event ended before the current Timing window, discard forever and ever.
-            if (event.endTimeMillis < windowstartTimeMillis) {
+            if (event.getEndTimeMillis() < windowstartTimeMillis) {
                 it.remove();
                 continue;
             }
 
-            final long startTimeMillis = Math.max(event.startTimeMillis, windowstartTimeMillis);
+            final long startTimeMillis = Math.max(event.getStartTimeMillis(),
-            timeAlreadyUsed += event.endTimeMillis - startTimeMillis;
+                            windowstartTimeMillis);
+            timeAlreadyUsed += event.getEndTimeMillis() - startTimeMillis;
         }
 
         if (DEBUG) {
@@ -425,17 +431,18 @@ class HighBrightnessModeController {
         // Calculate the time at which we want to recalculate mIsTimeAvailable in case a lux or
         // brightness change doesn't happen before then.
         long nextTimeout = -1;
+        final ArrayDeque<HbmEvent> hbmEvents = mHighBrightnessModeMetadata.getHbmEventQueue();
         if (mBrightness > mHbmData.transitionPoint) {
             // if we're in high-lux now, timeout when we run out of allowed time.
             nextTimeout = currentTime + remainingTime;
-        } else if (!mIsTimeAvailable && mEvents.size() > 0) {
+        } else if (!mIsTimeAvailable && hbmEvents.size() > 0) {
             // If we are not allowed...timeout when the oldest event moved outside of the timing
             // window by at least minTime. Basically, we're calculating the soonest time we can
             // get {@code timeMinMillis} back to us.
             final long windowstartTimeMillis = currentTime - mHbmData.timeWindowMillis;
-            final HbmEvent lastEvent = mEvents.peekLast();
+            final HbmEvent lastEvent = hbmEvents.peekLast();
             final long startTimePlusMinMillis =
-                    Math.max(windowstartTimeMillis, lastEvent.startTimeMillis)
+                    Math.max(windowstartTimeMillis, lastEvent.getStartTimeMillis())
                     + mHbmData.timeMinMillis;
             final long timeWhenMinIsGainedBack =
                     currentTime + (startTimePlusMinMillis - windowstartTimeMillis) - remainingTime;
@@ -459,9 +466,10 @@ class HighBrightnessModeController {
                     + ", mUnthrottledBrightness: " + mUnthrottledBrightness
                     + ", mThrottlingReason: "
                         + BrightnessInfo.briMaxReasonToString(mThrottlingReason)
-                    + ", RunningStartTimeMillis: " + mRunningStartTimeMillis
+                    + ", RunningStartTimeMillis: "
+                        + mHighBrightnessModeMetadata.getRunningStartTimeMillis()
                     + ", nextTimeout: " + (nextTimeout != -1 ? (nextTimeout - currentTime) : -1)
-                    + ", events: " + mEvents);
+                    + ", events: " + hbmEvents);
         }
 
         if (nextTimeout != -1) {
@@ -588,25 +596,6 @@ class HighBrightnessModeController {
         }
     }
 
-    /**
-     * Represents an event in which High Brightness Mode was enabled.
-     */
-    private static class HbmEvent {
-        public long startTimeMillis;
-        public long endTimeMillis;
-
-        HbmEvent(long startTimeMillis, long endTimeMillis) {
-            this.startTimeMillis = startTimeMillis;
-            this.endTimeMillis = endTimeMillis;
-        }
-
-        @Override
-        public String toString() {
-            return "[Event: {" + startTimeMillis + ", " + endTimeMillis + "}, total: "
-                    + ((endTimeMillis - startTimeMillis) / 1000) + "]";
-        }
-    }
-
     @VisibleForTesting
     class HdrListener extends SurfaceControlHdrLayerInfoListener {
         @Override

services/core/java/com/android/server/display/HighBrightnessModeMetadata.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.display;
+
+import java.util.ArrayDeque;
+
+
+/**
+ * Represents High Brightness Mode metadata associated
+ * with a specific internal physical display.
+ * Required for separately storing data like time information,
+ * and related events when display was in HBM mode per
+ * physical internal display.
+ */
+class HighBrightnessModeMetadata {
+    /**
+     * Queue of previous HBM-events ordered from most recent to least recent.
+     * Meant to store only the events that fall into the most recent
+     * {@link HighBrightnessModeData#timeWindowMillis mHbmData.timeWindowMillis}.
+     */
+    private final ArrayDeque<HbmEvent> mEvents = new ArrayDeque<>();
+
+    /**
+     * If HBM is currently running, this is the start time for the current HBM session.
+     */
+    private long mRunningStartTimeMillis = -1;
+
+    public long getRunningStartTimeMillis() {
+        return mRunningStartTimeMillis;
+    }
+
+    public void setRunningStartTimeMillis(long setTime) {
+        mRunningStartTimeMillis = setTime;
+    }
+
+    public ArrayDeque<HbmEvent> getHbmEventQueue() {
+        return mEvents;
+    }
+
+    public void addHbmEvent(HbmEvent hbmEvent) {
+        mEvents.addFirst(hbmEvent);
+    }
+}
+

services/tests/mockingservicestests/src/com/android/server/display/DisplayPowerController2Test.java

@@ -80,6 +80,8 @@ public final class DisplayPowerController2Test {
     @Mock
     private DisplayBlanker mDisplayBlankerMock;
     @Mock
+    private HighBrightnessModeMetadata mHighBrightnessModeMetadataMock;
+    @Mock
     private LogicalDisplay mLogicalDisplayMock;
     @Mock
     private DisplayDevice mDisplayDeviceMock;
@@ -169,7 +171,7 @@ public final class DisplayPowerController2Test {
                 mContextSpy, mInjector, mDisplayPowerCallbacksMock, mHandler,
                 mSensorManagerMock, mDisplayBlankerMock, mLogicalDisplayMock,
                 mBrightnessTrackerMock, mBrightnessSettingMock, () -> {
-        });
+        }, mHighBrightnessModeMetadataMock);
 
         when(mDisplayPowerStateMock.getScreenState()).thenReturn(Display.STATE_ON);
         // send a display power request

services/tests/mockingservicestests/src/com/android/server/display/DisplayPowerControllerTest.java

@@ -84,6 +84,8 @@ public final class DisplayPowerControllerTest {
     @Mock
     private DisplayDevice mDisplayDeviceMock;
     @Mock
+    private HighBrightnessModeMetadata mHighBrightnessModeMetadataMock;
+    @Mock
     private BrightnessTracker mBrightnessTrackerMock;
     @Mock
     private BrightnessSetting mBrightnessSettingMock;
@@ -151,7 +153,7 @@ public final class DisplayPowerControllerTest {
                 mContextSpy, mInjector, mDisplayPowerCallbacksMock, mHandler,
                 mSensorManagerMock, mDisplayBlankerMock, mLogicalDisplayMock,
                 mBrightnessTrackerMock, mBrightnessSettingMock, () -> {
-        });
+        }, mHighBrightnessModeMetadataMock);
 
         when(mDisplayPowerStateMock.getScreenState()).thenReturn(Display.STATE_ON);
         // send a display power request

services/tests/servicestests/src/com/android/server/display/HbmEventTest.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.display;
+
+import static org.junit.Assert.assertEquals;
+
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class HbmEventTest {
+    private long mStartTimeMillis;
+    private long mEndTimeMillis;
+    private HbmEvent mHbmEvent;
+
+    @Before
+    public void setUp() {
+        mStartTimeMillis = 10;
+        mEndTimeMillis = 20;
+        mHbmEvent = new HbmEvent(mStartTimeMillis, mEndTimeMillis);
+    }
+
+    @Test
+    public void getCorrectValues() {
+        assertEquals(mHbmEvent.getStartTimeMillis(), mStartTimeMillis);
+        assertEquals(mHbmEvent.getEndTimeMillis(), mEndTimeMillis);
+    }
+
+    @Test
+    public void toStringGeneratesExpectedString() {
+        String actualString = mHbmEvent.toString();
+        String expectedString = "HbmEvent: {startTimeMillis:" + mStartTimeMillis
+                + ", endTimeMillis: " + mEndTimeMillis + "}, total: "
+                + ((mEndTimeMillis - mStartTimeMillis) / 1000) + "]";
+        assertEquals(actualString, expectedString);
+    }
+}

services/tests/servicestests/src/com/android/server/display/HighBrightnessModeControllerTest.java

@@ -96,6 +96,7 @@ public class HighBrightnessModeControllerTest {
     private Binder mDisplayToken;
     private String mDisplayUniqueId;
     private Context mContextSpy;
+    private HighBrightnessModeMetadata mHighBrightnessModeMetadata;
 
     @Rule
     public FakeSettingsProviderRule mSettingsProviderRule = FakeSettingsProvider.rule();
@@ -118,6 +119,7 @@ public class HighBrightnessModeControllerTest {
         mTestLooper = new TestLooper(mClock::now);
         mDisplayToken = null;
         mDisplayUniqueId = "unique_id";
+
         mContextSpy = spy(new ContextWrapper(ApplicationProvider.getApplicationContext()));
         final MockContentResolver resolver = mSettingsProviderRule.mockContentResolver(mContextSpy);
         when(mContextSpy.getContentResolver()).thenReturn(resolver);
@@ -134,7 +136,8 @@ public class HighBrightnessModeControllerTest {
         initHandler(null);
         final HighBrightnessModeController hbmc = new HighBrightnessModeController(
                 mInjectorMock, mHandler, DISPLAY_WIDTH, DISPLAY_HEIGHT, mDisplayToken,
-                mDisplayUniqueId, DEFAULT_MIN, DEFAULT_MAX, null, null, () -> {}, mContextSpy);
+                mDisplayUniqueId, DEFAULT_MIN, DEFAULT_MAX, null, null, () -> {},
+                null, mContextSpy);
         assertState(hbmc, DEFAULT_MIN, DEFAULT_MAX, HIGH_BRIGHTNESS_MODE_OFF);
         assertEquals(hbmc.getTransitionPoint(), HBM_TRANSITION_POINT_INVALID, 0.0f);
     }
@@ -144,7 +147,8 @@ public class HighBrightnessModeControllerTest {
         initHandler(null);
         final HighBrightnessModeController hbmc = new HighBrightnessModeController(
                 mInjectorMock, mHandler, DISPLAY_WIDTH, DISPLAY_HEIGHT, mDisplayToken,
-                mDisplayUniqueId, DEFAULT_MIN, DEFAULT_MAX, null, null, () -> {}, mContextSpy);
+                mDisplayUniqueId, DEFAULT_MIN, DEFAULT_MAX, null, null, () -> {},
+                null, mContextSpy);
         hbmc.setAutoBrightnessEnabled(AUTO_BRIGHTNESS_ENABLED);
         hbmc.onAmbientLuxChange(MINIMUM_LUX - 1); // below allowed range
         assertState(hbmc, DEFAULT_MIN, DEFAULT_MAX, HIGH_BRIGHTNESS_MODE_OFF);
@@ -699,9 +703,12 @@ public class HighBrightnessModeControllerTest {
     // Creates instance with standard initialization values.
     private HighBrightnessModeController createDefaultHbm(OffsettableClock clock) {
         initHandler(clock);
+        if (mHighBrightnessModeMetadata == null) {
+            mHighBrightnessModeMetadata = new HighBrightnessModeMetadata();
+        }
         return new HighBrightnessModeController(mInjectorMock, mHandler, DISPLAY_WIDTH,
                 DISPLAY_HEIGHT, mDisplayToken, mDisplayUniqueId, DEFAULT_MIN, DEFAULT_MAX,
-                DEFAULT_HBM_DATA, null, () -> {}, mContextSpy);
+                DEFAULT_HBM_DATA, null, () -> {}, mHighBrightnessModeMetadata, mContextSpy);
     }
 
     private void initHandler(OffsettableClock clock) {

services/tests/servicestests/src/com/android/server/display/HighBrightnessModeMetadataTest.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.display;
+
+import static org.junit.Assert.assertEquals;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public final class HighBrightnessModeMetadataTest {
+    private HighBrightnessModeMetadata mHighBrightnessModeMetadata;
+
+    private long mRunningStartTimeMillis = -1;
+
+    @Before
+    public void setUp() {
+        mHighBrightnessModeMetadata = new HighBrightnessModeMetadata();
+    }
+
+    @Test
+    public void checkDefaultValues() {
+        assertEquals(mHighBrightnessModeMetadata.getRunningStartTimeMillis(),
+                mRunningStartTimeMillis);
+        assertEquals(mHighBrightnessModeMetadata.getHbmEventQueue().size(), 0);
+    }
+
+    @Test
+    public void checkSetValues() {
+        mRunningStartTimeMillis = 10;
+        mHighBrightnessModeMetadata.setRunningStartTimeMillis(mRunningStartTimeMillis);
+        assertEquals(mHighBrightnessModeMetadata.getRunningStartTimeMillis(),
+                mRunningStartTimeMillis);
+        HbmEvent expectedHbmEvent = new HbmEvent(10, 20);
+        mHighBrightnessModeMetadata.addHbmEvent(expectedHbmEvent);
+        HbmEvent actualHbmEvent  = mHighBrightnessModeMetadata.getHbmEventQueue().peekFirst();
+        assertEquals(expectedHbmEvent.toString(), actualHbmEvent.toString());
+    }
+}