Merge "[hbm] Separate HBM times for multi-display devices." into tm-qpr-dev
diff --git a/services/core/java/com/android/server/display/DisplayManagerService.java b/services/core/java/com/android/server/display/DisplayManagerService.java
index 8f35924..5cfe65b 100644
--- a/services/core/java/com/android/server/display/DisplayManagerService.java
+++ b/services/core/java/com/android/server/display/DisplayManagerService.java
@@ -104,6 +104,7 @@
 import android.provider.Settings;
 import android.sysprop.DisplayProperties;
 import android.text.TextUtils;
+import android.util.ArrayMap;
 import android.util.ArraySet;
 import android.util.EventLog;
 import android.util.IntArray;
@@ -256,6 +257,13 @@
     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>();
 
@@ -1570,7 +1578,16 @@
 
         DisplayPowerController 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);
         }
     }
 
@@ -1627,7 +1644,15 @@
         final int displayId = display.getDisplayIdLocked();
         final DisplayPowerController 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);
         }
     }
 
@@ -2611,6 +2636,31 @@
         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;
+    }
+
     private void addDisplayPowerControllerLocked(LogicalDisplay display) {
         if (mPowerHandler == null) {
             // initPowerManagement has not yet been called.
@@ -2622,10 +2672,18 @@
 
         final BrightnessSetting brightnessSetting = new BrightnessSetting(mPersistentDataStore,
                 display, mSyncRoot);
+
+        // 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);
+
         final DisplayPowerController displayPowerController = new DisplayPowerController(
                 mContext, mDisplayPowerCallbacks, mPowerHandler, mSensorManager,
                 mDisplayBlanker, display, mBrightnessTracker, brightnessSetting,
-                () -> handleBrightnessChange(display));
+                () -> handleBrightnessChange(display), hbmMetadata);
         mDisplayPowerControllers.append(display.getDisplayIdLocked(), displayPowerController);
     }
 
diff --git a/services/core/java/com/android/server/display/DisplayPowerController.java b/services/core/java/com/android/server/display/DisplayPowerController.java
index f88a337..b431306 100644
--- a/services/core/java/com/android/server/display/DisplayPowerController.java
+++ b/services/core/java/com/android/server/display/DisplayPowerController.java
@@ -391,6 +391,7 @@
     private float[] mNitsRange;
 
     private final HighBrightnessModeController mHbmController;
+    private final HighBrightnessModeMetadata mHighBrightnessModeMetadata;
 
     private final BrightnessThrottler mBrightnessThrottler;
 
@@ -511,7 +512,7 @@
             DisplayPowerCallbacks callbacks, Handler handler,
             SensorManager sensorManager, DisplayBlanker blanker, LogicalDisplay logicalDisplay,
             BrightnessTracker brightnessTracker, BrightnessSetting brightnessSetting,
-            Runnable onBrightnessChangeRunnable) {
+            Runnable onBrightnessChangeRunnable, HighBrightnessModeMetadata hbmMetadata) {
         mLogicalDisplay = logicalDisplay;
         mDisplayId = mLogicalDisplay.getDisplayIdLocked();
         final String displayIdStr = "[" + mDisplayId + "]";
@@ -521,6 +522,7 @@
         mSuspendBlockerIdProxPositive = displayIdStr + "prox positive";
         mSuspendBlockerIdProxNegative = displayIdStr + "prox negative";
         mSuspendBlockerIdProxDebounce = displayIdStr + "prox debounce";
+        mHighBrightnessModeMetadata = hbmMetadata;
 
         mDisplayDevice = mLogicalDisplay.getPrimaryDisplayDeviceLocked();
         mUniqueDisplayId = logicalDisplay.getPrimaryDisplayDeviceLocked().getUniqueId();
@@ -793,7 +795,7 @@
      * of each display need to be properly reflected in AutomaticBrightnessController.
      */
     @GuardedBy("DisplayManagerService.mSyncRoot")
-    public void onDisplayChanged() {
+    public void onDisplayChanged(HighBrightnessModeMetadata hbmMetadata) {
         final DisplayDevice device = mLogicalDisplay.getPrimaryDisplayDeviceLocked();
         if (device == null) {
             Slog.wtf(TAG, "Display Device is null in DisplayPowerController for display: "
@@ -815,7 +817,7 @@
                 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 unknown so
@@ -872,7 +874,8 @@
         }
     }
 
-    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();
@@ -885,6 +888,7 @@
                     mBrightnessRampIncreaseMaxTimeMillis,
                     mBrightnessRampDecreaseMaxTimeMillis);
         }
+        mHbmController.setHighBrightnessModeMetadata(hbmMetadata);
         mHbmController.resetHbmData(info.width, info.height, token, info.uniqueId,
                 mDisplayDeviceConfig.getHighBrightnessModeData(),
                 new HighBrightnessModeController.HdrBrightnessDeviceConfig() {
@@ -1965,7 +1969,7 @@
                     if (mAutomaticBrightnessController != null) {
                         mAutomaticBrightnessController.update();
                     }
-                }, mContext);
+                }, mHighBrightnessModeMetadata, mContext);
     }
 
     private BrightnessThrottler createBrightnessThrottlerLocked() {
diff --git a/services/core/java/com/android/server/display/HbmEvent.java b/services/core/java/com/android/server/display/HbmEvent.java
new file mode 100644
index 0000000..5675e2f
--- /dev/null
+++ b/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) + "]";
+    }
+}
diff --git a/services/core/java/com/android/server/display/HighBrightnessModeController.java b/services/core/java/com/android/server/display/HighBrightnessModeController.java
index 0b9d4de..ac32d53 100644
--- a/services/core/java/com/android/server/display/HighBrightnessModeController.java
+++ b/services/core/java/com/android/server/display/HighBrightnessModeController.java
@@ -42,8 +42,8 @@
 import com.android.server.display.DisplayManagerService.Clock;
 
 import java.io.PrintWriter;
+import java.util.ArrayDeque;
 import java.util.Iterator;
-import java.util.LinkedList;
 
 /**
  * Controls the status of high-brightness mode for devices that support it. This class assumes that
@@ -105,30 +105,24 @@
     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;
-
-    /**
-     * List of previous HBM-events ordered from most recent to least recent.
-     * Meant to store only the events that fall into the most recent
-     * {@link mHbmData.timeWindowMillis}.
-     */
-    private LinkedList<HbmEvent> mEvents = new LinkedList<>();
+    private HighBrightnessModeMetadata mHighBrightnessModeMetadata = null;
 
     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 +131,7 @@
         mBrightnessMin = brightnessMin;
         mBrightnessMax = brightnessMax;
         mHbmChangeCallback = hbmChangeCallback;
+        mHighBrightnessModeMetadata = hbmMetadata;
         mSkinThermalStatusObserver = new SkinThermalStatusObserver(mInjector, mHandler);
         mSettingsObserver = new SettingsObserver(mHandler);
         mRecalcRunnable = this::recalculateTimeAllowance;
@@ -222,19 +217,22 @@
 
         // 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));
-                mRunningStartTimeMillis = -1;
+                final HbmEvent hbmEvent = new HbmEvent(runningStartTime, currentTime);
+                mHighBrightnessModeMetadata.addHbmEvent(hbmEvent);
+                mHighBrightnessModeMetadata.setRunningStartTimeMillis(-1);
 
                 if (DEBUG) {
-                    Slog.d(TAG, "New HBM event: " + mEvents.getFirst());
+                    Slog.d(TAG, "New HBM event: "
+                            + mHighBrightnessModeMetadata.getHbmEventQueue().peekFirst());
                 }
             }
         }
@@ -260,6 +258,10 @@
         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 +318,22 @@
         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) {
-            lastStartTime = dumpHbmEvent(pw, new HbmEvent(mRunningStartTimeMillis, currentTime));
+        long runningStartTimeMillis = mHighBrightnessModeMetadata.getRunningStartTimeMillis();
+        if (runningStartTimeMillis != -1) {
+            lastStartTime = dumpHbmEvent(pw, new HbmEvent(runningStartTimeMillis, currentTime));
         }
-        for (HbmEvent event : mEvents) {
-            if (lastStartTime > event.endTimeMillis) {
+        for (HbmEvent event : mHighBrightnessModeMetadata.getHbmEventQueue()) {
+            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 +342,12 @@
     }
 
     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.endTimeMillis) + "] ("
+                + TimeUtils.formatUptime(event.getStartTimeMillis()) + ", "
+                + TimeUtils.formatUptime(event.getEndTimeMillis()) + "] ("
                 + TimeUtils.formatDuration(duration) + ")");
-        return event.startTimeMillis;
+        return event.getStartTimeMillis();
     }
 
     private boolean isCurrentlyAllowed() {
@@ -372,13 +376,15 @@
 
         // First, lets see how much time we've taken for any currently running
         // session of HBM.
-        if (mRunningStartTimeMillis > 0) {
-            if (mRunningStartTimeMillis > currentTime) {
+        long runningStartTimeMillis = mHighBrightnessModeMetadata.getRunningStartTimeMillis();
+        if (runningStartTimeMillis > 0) {
+            if (runningStartTimeMillis > currentTime) {
                 Slog.e(TAG, "Start time set to the future. curr: " + currentTime
-                        + ", start: " + mRunningStartTimeMillis);
-                mRunningStartTimeMillis = currentTime;
+                        + ", start: " + runningStartTimeMillis);
+                mHighBrightnessModeMetadata.setRunningStartTimeMillis(currentTime);
+                runningStartTimeMillis = currentTime;
             }
-            timeAlreadyUsed = currentTime - mRunningStartTimeMillis;
+            timeAlreadyUsed = currentTime - runningStartTimeMillis;
         }
 
         if (DEBUG) {
@@ -387,18 +393,19 @@
 
         // 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);
-            timeAlreadyUsed += event.endTimeMillis - startTimeMillis;
+            final long startTimeMillis = Math.max(event.getStartTimeMillis(),
+                            windowstartTimeMillis);
+            timeAlreadyUsed += event.getEndTimeMillis() - startTimeMillis;
         }
 
         if (DEBUG) {
@@ -425,17 +432,18 @@
         // 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.getLast();
+            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 +467,10 @@
                     + ", 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 +597,6 @@
         }
     }
 
-    /**
-     * 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
diff --git a/services/core/java/com/android/server/display/HighBrightnessModeMetadata.java b/services/core/java/com/android/server/display/HighBrightnessModeMetadata.java
new file mode 100644
index 0000000..37234ff
--- /dev/null
+++ b/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);
+    }
+}
+
diff --git a/services/tests/servicestests/src/com/android/server/display/HbmEventTest.java b/services/tests/servicestests/src/com/android/server/display/HbmEventTest.java
new file mode 100644
index 0000000..24fc348
--- /dev/null
+++ b/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);
+    }
+}
diff --git a/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeControllerTest.java b/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeControllerTest.java
index 53fa3e2..da2e1be 100644
--- a/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeControllerTest.java
+++ b/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeControllerTest.java
@@ -27,9 +27,7 @@
 import static com.android.server.display.AutomaticBrightnessController.AUTO_BRIGHTNESS_ENABLED;
 import static com.android.server.display.AutomaticBrightnessController
                                                       .AUTO_BRIGHTNESS_OFF_DUE_TO_DISPLAY_STATE;
-
 import static com.android.server.display.DisplayDeviceConfig.HDR_PERCENT_OF_SCREEN_REQUIRED_DEFAULT;
-
 import static com.android.server.display.HighBrightnessModeController.HBM_TRANSITION_POINT_INVALID;
 
 import static org.junit.Assert.assertEquals;
@@ -102,6 +100,7 @@
     private Binder mDisplayToken;
     private String mDisplayUniqueId;
     private Context mContextSpy;
+    private HighBrightnessModeMetadata mHighBrightnessModeMetadata;
 
     @Rule
     public FakeSettingsProviderRule mSettingsProviderRule = FakeSettingsProvider.rule();
@@ -124,6 +123,7 @@
         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);
@@ -140,7 +140,8 @@
         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);
     }
@@ -150,7 +151,8 @@
         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);
@@ -705,9 +707,12 @@
     // 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) {
diff --git a/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeMetadataTest.java b/services/tests/servicestests/src/com/android/server/display/HighBrightnessModeMetadataTest.java
new file mode 100644
index 0000000..ede54e0
--- /dev/null
+++ b/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());
+    }
+}