diff --git a/services/core/java/com/android/server/notification/NotificationManagerService.java b/services/core/java/com/android/server/notification/NotificationManagerService.java
index a55b118..37f980d 100755
--- a/services/core/java/com/android/server/notification/NotificationManagerService.java
+++ b/services/core/java/com/android/server/notification/NotificationManagerService.java
@@ -1978,34 +1978,39 @@
             return (haystack & needle) != 0;
         }
 
-        public boolean isInLockDownMode() {
-            return mIsInLockDownMode;
+        // Return whether the user is in lockdown mode.
+        // If the flag is not set, we assume the user is not in lockdown.
+        public boolean isInLockDownMode(int userId) {
+            return mUserInLockDownMode.get(userId, false);
         }
 
         @Override
         public synchronized void onStrongAuthRequiredChanged(int userId) {
             boolean userInLockDownModeNext = containsFlag(getStrongAuthForUser(userId),
                     STRONG_AUTH_REQUIRED_AFTER_USER_LOCKDOWN);
-            mUserInLockDownMode.put(userId, userInLockDownModeNext);
-            boolean isInLockDownModeNext = mUserInLockDownMode.indexOfValue(true) != -1;
 
-            if (mIsInLockDownMode == isInLockDownModeNext) {
+            // Nothing happens if the lockdown mode of userId keeps the same.
+            if (userInLockDownModeNext == isInLockDownMode(userId)) {
                 return;
             }
 
-            if (isInLockDownModeNext) {
-                cancelNotificationsWhenEnterLockDownMode();
+            // When the lockdown mode is changed, we perform the following steps.
+            // If the userInLockDownModeNext is true, all the function calls to
+            // notifyPostedLocked and notifyRemovedLocked will not be executed.
+            // The cancelNotificationsWhenEnterLockDownMode calls notifyRemovedLocked
+            // and postNotificationsWhenExitLockDownMode calls notifyPostedLocked.
+            // So we shall call cancelNotificationsWhenEnterLockDownMode before
+            // we set mUserInLockDownMode as true.
+            // On the other hand, if the userInLockDownModeNext is false, we shall call
+            // postNotificationsWhenExitLockDownMode after we put false into mUserInLockDownMode
+            if (userInLockDownModeNext) {
+                cancelNotificationsWhenEnterLockDownMode(userId);
             }
 
-            // When the mIsInLockDownMode is true, both notifyPostedLocked and
-            // notifyRemovedLocked will be dismissed. So we shall call
-            // cancelNotificationsWhenEnterLockDownMode before we set mIsInLockDownMode
-            // as true and call postNotificationsWhenExitLockDownMode after we set
-            // mIsInLockDownMode as false.
-            mIsInLockDownMode = isInLockDownModeNext;
+            mUserInLockDownMode.put(userId, userInLockDownModeNext);
 
-            if (!isInLockDownModeNext) {
-                postNotificationsWhenExitLockDownMode();
+            if (!userInLockDownModeNext) {
+                postNotificationsWhenExitLockDownMode(userId);
             }
         }
     }
@@ -9679,11 +9684,14 @@
         }
     }
 
-    private void cancelNotificationsWhenEnterLockDownMode() {
+    private void cancelNotificationsWhenEnterLockDownMode(int userId) {
         synchronized (mNotificationLock) {
             int numNotifications = mNotificationList.size();
             for (int i = 0; i < numNotifications; i++) {
                 NotificationRecord rec = mNotificationList.get(i);
+                if (rec.getUser().getIdentifier() != userId) {
+                    continue;
+                }
                 mListeners.notifyRemovedLocked(rec, REASON_CANCEL_ALL,
                         rec.getStats());
             }
@@ -9691,14 +9699,23 @@
         }
     }
 
-    private void postNotificationsWhenExitLockDownMode() {
+    private void postNotificationsWhenExitLockDownMode(int userId) {
         synchronized (mNotificationLock) {
             int numNotifications = mNotificationList.size();
+            // Set the delay to spread out the burst of notifications.
+            long delay = 0;
             for (int i = 0; i < numNotifications; i++) {
                 NotificationRecord rec = mNotificationList.get(i);
-                mListeners.notifyPostedLocked(rec, rec);
+                if (rec.getUser().getIdentifier() != userId) {
+                    continue;
+                }
+                mHandler.postDelayed(() -> {
+                    synchronized (mNotificationLock) {
+                        mListeners.notifyPostedLocked(rec, rec);
+                    }
+                }, delay);
+                delay += 20;
             }
-
         }
     }
 
@@ -9877,6 +9894,9 @@
 
         for (int i = 0; i < N; i++) {
             NotificationRecord record = mNotificationList.get(i);
+            if (isInLockDownMode(record.getUser().getIdentifier())) {
+                continue;
+            }
             if (!isVisibleToListener(record.getSbn(), record.getNotificationType(), info)) {
                 continue;
             }
@@ -9918,8 +9938,8 @@
                 rankings.toArray(new NotificationListenerService.Ranking[0]));
     }
 
-    boolean isInLockDownMode() {
-        return mStrongAuthTracker.isInLockDownMode();
+    boolean isInLockDownMode(int userId) {
+        return mStrongAuthTracker.isInLockDownMode(userId);
     }
 
     boolean hasCompanionDevice(ManagedServiceInfo info) {
@@ -10989,7 +11009,7 @@
         @GuardedBy("mNotificationLock")
         void notifyPostedLocked(NotificationRecord r, NotificationRecord old,
                 boolean notifyAllListeners) {
-            if (isInLockDownMode()) {
+            if (isInLockDownMode(r.getUser().getIdentifier())) {
                 return;
             }
 
@@ -11095,7 +11115,7 @@
         @GuardedBy("mNotificationLock")
         public void notifyRemovedLocked(NotificationRecord r, int reason,
                 NotificationStats notificationStats) {
-            if (isInLockDownMode()) {
+            if (isInLockDownMode(r.getUser().getIdentifier())) {
                 return;
             }
 
@@ -11144,10 +11164,6 @@
          */
         @GuardedBy("mNotificationLock")
         public void notifyRankingUpdateLocked(List<NotificationRecord> changedHiddenNotifications) {
-            if (isInLockDownMode()) {
-                return;
-            }
-
             boolean isHiddenRankingUpdate = changedHiddenNotifications != null
                     && changedHiddenNotifications.size() > 0;
             // TODO (b/73052211): if the ranking update changed the notification type,
diff --git a/services/tests/uiservicestests/src/com/android/server/notification/NotificationListenersTest.java b/services/tests/uiservicestests/src/com/android/server/notification/NotificationListenersTest.java
index 101a5cb..bf66dee 100644
--- a/services/tests/uiservicestests/src/com/android/server/notification/NotificationListenersTest.java
+++ b/services/tests/uiservicestests/src/com/android/server/notification/NotificationListenersTest.java
@@ -488,63 +488,112 @@
 
     @Test
     public void testNotifyPostedLockedInLockdownMode() {
-        NotificationRecord r = mock(NotificationRecord.class);
-        NotificationRecord old = mock(NotificationRecord.class);
+        NotificationRecord r0 = mock(NotificationRecord.class);
+        NotificationRecord old0 = mock(NotificationRecord.class);
+        UserHandle uh0 = mock(UserHandle.class);
 
-        // before the lockdown mode
-        when(mNm.isInLockDownMode()).thenReturn(false);
-        mListeners.notifyPostedLocked(r, old, true);
-        mListeners.notifyPostedLocked(r, old, false);
-        verify(r, atLeast(2)).getSbn();
+        NotificationRecord r1 = mock(NotificationRecord.class);
+        NotificationRecord old1 = mock(NotificationRecord.class);
+        UserHandle uh1 = mock(UserHandle.class);
 
-        // in the lockdown mode
-        reset(r);
-        reset(old);
-        when(mNm.isInLockDownMode()).thenReturn(true);
-        mListeners.notifyPostedLocked(r, old, true);
-        mListeners.notifyPostedLocked(r, old, false);
-        verify(r, never()).getSbn();
-    }
+        // Neither user0 and user1 is in the lockdown mode
+        when(r0.getUser()).thenReturn(uh0);
+        when(uh0.getIdentifier()).thenReturn(0);
+        when(mNm.isInLockDownMode(0)).thenReturn(false);
 
-    @Test
-    public void testnotifyRankingUpdateLockedInLockdownMode() {
-        List chn = mock(List.class);
+        when(r1.getUser()).thenReturn(uh1);
+        when(uh1.getIdentifier()).thenReturn(1);
+        when(mNm.isInLockDownMode(1)).thenReturn(false);
 
-        // before the lockdown mode
-        when(mNm.isInLockDownMode()).thenReturn(false);
-        mListeners.notifyRankingUpdateLocked(chn);
-        verify(chn, atLeast(1)).size();
+        mListeners.notifyPostedLocked(r0, old0, true);
+        mListeners.notifyPostedLocked(r0, old0, false);
+        verify(r0, atLeast(2)).getSbn();
 
-        // in the lockdown mode
-        reset(chn);
-        when(mNm.isInLockDownMode()).thenReturn(true);
-        mListeners.notifyRankingUpdateLocked(chn);
-        verify(chn, never()).size();
+        mListeners.notifyPostedLocked(r1, old1, true);
+        mListeners.notifyPostedLocked(r1, old1, false);
+        verify(r1, atLeast(2)).getSbn();
+
+        // Reset
+        reset(r0);
+        reset(old0);
+        reset(r1);
+        reset(old1);
+
+        // Only user 0 is in the lockdown mode
+        when(r0.getUser()).thenReturn(uh0);
+        when(uh0.getIdentifier()).thenReturn(0);
+        when(mNm.isInLockDownMode(0)).thenReturn(true);
+
+        when(r1.getUser()).thenReturn(uh1);
+        when(uh1.getIdentifier()).thenReturn(1);
+        when(mNm.isInLockDownMode(1)).thenReturn(false);
+
+        mListeners.notifyPostedLocked(r0, old0, true);
+        mListeners.notifyPostedLocked(r0, old0, false);
+        verify(r0, never()).getSbn();
+
+        mListeners.notifyPostedLocked(r1, old1, true);
+        mListeners.notifyPostedLocked(r1, old1, false);
+        verify(r1, atLeast(2)).getSbn();
     }
 
     @Test
     public void testNotifyRemovedLockedInLockdownMode() throws NoSuchFieldException {
-        NotificationRecord r = mock(NotificationRecord.class);
-        NotificationStats rs = mock(NotificationStats.class);
+        NotificationRecord r0 = mock(NotificationRecord.class);
+        NotificationStats rs0 = mock(NotificationStats.class);
+        UserHandle uh0 = mock(UserHandle.class);
+
+        NotificationRecord r1 = mock(NotificationRecord.class);
+        NotificationStats rs1 = mock(NotificationStats.class);
+        UserHandle uh1 = mock(UserHandle.class);
+
         StatusBarNotification sbn = mock(StatusBarNotification.class);
         FieldSetter.setField(mNm,
                 NotificationManagerService.class.getDeclaredField("mHandler"),
                 mock(NotificationManagerService.WorkerHandler.class));
 
-        // before the lockdown mode
-        when(mNm.isInLockDownMode()).thenReturn(false);
-        when(r.getSbn()).thenReturn(sbn);
-        mListeners.notifyRemovedLocked(r, 0, rs);
-        mListeners.notifyRemovedLocked(r, 0, rs);
-        verify(r, atLeast(2)).getSbn();
+        // Neither user0 and user1 is in the lockdown mode
+        when(r0.getUser()).thenReturn(uh0);
+        when(uh0.getIdentifier()).thenReturn(0);
+        when(mNm.isInLockDownMode(0)).thenReturn(false);
+        when(r0.getSbn()).thenReturn(sbn);
 
-        // in the lockdown mode
-        reset(r);
-        reset(rs);
-        when(mNm.isInLockDownMode()).thenReturn(true);
-        when(r.getSbn()).thenReturn(sbn);
-        mListeners.notifyRemovedLocked(r, 0, rs);
-        mListeners.notifyRemovedLocked(r, 0, rs);
-        verify(r, never()).getSbn();
+        when(r1.getUser()).thenReturn(uh1);
+        when(uh1.getIdentifier()).thenReturn(1);
+        when(mNm.isInLockDownMode(1)).thenReturn(false);
+        when(r1.getSbn()).thenReturn(sbn);
+
+        mListeners.notifyRemovedLocked(r0, 0, rs0);
+        mListeners.notifyRemovedLocked(r0, 0, rs0);
+        verify(r0, atLeast(2)).getSbn();
+
+        mListeners.notifyRemovedLocked(r1, 0, rs1);
+        mListeners.notifyRemovedLocked(r1, 0, rs1);
+        verify(r1, atLeast(2)).getSbn();
+
+        // Reset
+        reset(r0);
+        reset(rs0);
+        reset(r1);
+        reset(rs1);
+
+        // Only user 0 is in the lockdown mode
+        when(r0.getUser()).thenReturn(uh0);
+        when(uh0.getIdentifier()).thenReturn(0);
+        when(mNm.isInLockDownMode(0)).thenReturn(true);
+        when(r0.getSbn()).thenReturn(sbn);
+
+        when(r1.getUser()).thenReturn(uh1);
+        when(uh1.getIdentifier()).thenReturn(1);
+        when(mNm.isInLockDownMode(1)).thenReturn(false);
+        when(r1.getSbn()).thenReturn(sbn);
+
+        mListeners.notifyRemovedLocked(r0, 0, rs0);
+        mListeners.notifyRemovedLocked(r0, 0, rs0);
+        verify(r0, never()).getSbn();
+
+        mListeners.notifyRemovedLocked(r1, 0, rs1);
+        mListeners.notifyRemovedLocked(r1, 0, rs1);
+        verify(r1, atLeast(2)).getSbn();
     }
 }
diff --git a/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java b/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java
index a545c83..beaa6e0 100755
--- a/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java
+++ b/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java
@@ -174,6 +174,7 @@
 import android.service.notification.ConversationChannelWrapper;
 import android.service.notification.NotificationListenerFilter;
 import android.service.notification.NotificationListenerService;
+import android.service.notification.NotificationRankingUpdate;
 import android.service.notification.NotificationStats;
 import android.service.notification.StatusBarNotification;
 import android.service.notification.ZenPolicy;
@@ -9781,10 +9782,10 @@
         mStrongAuthTracker.setGetStrongAuthForUserReturnValue(
                 STRONG_AUTH_REQUIRED_AFTER_USER_LOCKDOWN);
         mStrongAuthTracker.onStrongAuthRequiredChanged(mContext.getUserId());
-        assertTrue(mStrongAuthTracker.isInLockDownMode());
-        mStrongAuthTracker.setGetStrongAuthForUserReturnValue(0);
+        assertTrue(mStrongAuthTracker.isInLockDownMode(mContext.getUserId()));
+        mStrongAuthTracker.setGetStrongAuthForUserReturnValue(mContext.getUserId());
         mStrongAuthTracker.onStrongAuthRequiredChanged(mContext.getUserId());
-        assertFalse(mStrongAuthTracker.isInLockDownMode());
+        assertFalse(mStrongAuthTracker.isInLockDownMode(mContext.getUserId()));
     }
 
     @Test
@@ -9800,8 +9801,8 @@
         // when entering the lockdown mode, cancel the 2 notifications.
         mStrongAuthTracker.setGetStrongAuthForUserReturnValue(
                 STRONG_AUTH_REQUIRED_AFTER_USER_LOCKDOWN);
-        mStrongAuthTracker.onStrongAuthRequiredChanged(mContext.getUserId());
-        assertTrue(mStrongAuthTracker.isInLockDownMode());
+        mStrongAuthTracker.onStrongAuthRequiredChanged(0);
+        assertTrue(mStrongAuthTracker.isInLockDownMode(0));
 
         // the notifyRemovedLocked function is called twice due to REASON_CANCEL_ALL.
         ArgumentCaptor<Integer> captor = ArgumentCaptor.forClass(Integer.class);
@@ -9810,10 +9811,46 @@
 
         // exit lockdown mode.
         mStrongAuthTracker.setGetStrongAuthForUserReturnValue(0);
-        mStrongAuthTracker.onStrongAuthRequiredChanged(mContext.getUserId());
+        mStrongAuthTracker.onStrongAuthRequiredChanged(0);
+        assertFalse(mStrongAuthTracker.isInLockDownMode(0));
 
         // the notifyPostedLocked function is called twice.
-        verify(mListeners, times(2)).notifyPostedLocked(any(), any());
+        verify(mWorkerHandler, times(2)).postDelayed(any(Runnable.class), anyLong());
+        //verify(mListeners, times(2)).notifyPostedLocked(any(), any());
+    }
+
+    @Test
+    public void testMakeRankingUpdateLockedInLockDownMode() {
+        // post 2 notifications from a same package
+        NotificationRecord pkgA = new NotificationRecord(mContext,
+                generateSbn("a", 1000, 9, 0), mTestNotificationChannel);
+        mService.addNotification(pkgA);
+        NotificationRecord pkgB = new NotificationRecord(mContext,
+                generateSbn("a", 1000, 9, 1), mTestNotificationChannel);
+        mService.addNotification(pkgB);
+
+        mService.setIsVisibleToListenerReturnValue(true);
+        NotificationRankingUpdate nru = mService.makeRankingUpdateLocked(null);
+        assertEquals(2, nru.getRankingMap().getOrderedKeys().length);
+
+        // when only user 0 entering the lockdown mode, its notification will be suppressed.
+        mStrongAuthTracker.setGetStrongAuthForUserReturnValue(
+                STRONG_AUTH_REQUIRED_AFTER_USER_LOCKDOWN);
+        mStrongAuthTracker.onStrongAuthRequiredChanged(0);
+        assertTrue(mStrongAuthTracker.isInLockDownMode(0));
+        assertFalse(mStrongAuthTracker.isInLockDownMode(1));
+
+        nru = mService.makeRankingUpdateLocked(null);
+        assertEquals(1, nru.getRankingMap().getOrderedKeys().length);
+
+        // User 0 exits lockdown mode. Its notification will be resumed.
+        mStrongAuthTracker.setGetStrongAuthForUserReturnValue(0);
+        mStrongAuthTracker.onStrongAuthRequiredChanged(0);
+        assertFalse(mStrongAuthTracker.isInLockDownMode(0));
+        assertFalse(mStrongAuthTracker.isInLockDownMode(1));
+
+        nru = mService.makeRankingUpdateLocked(null);
+        assertEquals(2, nru.getRankingMap().getOrderedKeys().length);
     }
 
     @Test
diff --git a/services/tests/uiservicestests/src/com/android/server/notification/TestableNotificationManagerService.java b/services/tests/uiservicestests/src/com/android/server/notification/TestableNotificationManagerService.java
index b49e5cb..8cf74fb 100644
--- a/services/tests/uiservicestests/src/com/android/server/notification/TestableNotificationManagerService.java
+++ b/services/tests/uiservicestests/src/com/android/server/notification/TestableNotificationManagerService.java
@@ -19,10 +19,12 @@
 import android.companion.ICompanionDeviceManager;
 import android.content.ComponentName;
 import android.content.Context;
+import android.service.notification.StatusBarNotification;
 
 import androidx.annotation.Nullable;
 
 import com.android.internal.logging.InstanceIdSequence;
+import com.android.server.notification.ManagedServices.ManagedServiceInfo;
 
 import java.util.HashSet;
 import java.util.Set;
@@ -37,6 +39,9 @@
     @Nullable
     NotificationAssistantAccessGrantedCallback mNotificationAssistantAccessGrantedCallback;
 
+    @Nullable
+    Boolean mIsVisibleToListenerReturnValue = null;
+
     TestableNotificationManagerService(Context context, NotificationRecordLogger logger,
             InstanceIdSequence notificationInstanceIdSequence) {
         super(context, logger, notificationInstanceIdSequence);
@@ -119,6 +124,19 @@
         mShowReviewPermissionsNotification = setting;
     }
 
+    protected void setIsVisibleToListenerReturnValue(boolean value) {
+        mIsVisibleToListenerReturnValue = value;
+    }
+
+    @Override
+    boolean isVisibleToListener(StatusBarNotification sbn, int notificationType,
+            ManagedServiceInfo listener) {
+        if (mIsVisibleToListenerReturnValue != null) {
+            return mIsVisibleToListenerReturnValue;
+        }
+        return super.isVisibleToListener(sbn, notificationType, listener);
+    }
+
     public class StrongAuthTrackerFake extends NotificationManagerService.StrongAuthTracker {
         private int mGetStrongAuthForUserReturnValue = 0;
         StrongAuthTrackerFake(Context context) {