diff --git a/packages/SystemUI/src/com/android/systemui/GuestResumeSessionReceiver.java b/packages/SystemUI/src/com/android/systemui/GuestResumeSessionReceiver.java
index 104b71f..6e1fb6d 100644
--- a/packages/SystemUI/src/com/android/systemui/GuestResumeSessionReceiver.java
+++ b/packages/SystemUI/src/com/android/systemui/GuestResumeSessionReceiver.java
@@ -20,6 +20,8 @@
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.pm.UserInfo;
+import android.os.HandlerExecutor;
+import android.os.HandlerThread;
 import android.os.UserHandle;
 
 import androidx.annotation.NonNull;
@@ -57,6 +59,7 @@
     private final SecureSettings mSecureSettings;
     private final ResetSessionDialog.Factory mResetSessionDialogFactory;
     private final GuestSessionNotification mGuestSessionNotification;
+    private final HandlerThread mHandlerThread;
 
     @VisibleForTesting
     public final UserTracker.Callback mUserChangedCallback =
@@ -107,13 +110,16 @@
         mSecureSettings = secureSettings;
         mGuestSessionNotification = guestSessionNotification;
         mResetSessionDialogFactory = resetSessionDialogFactory;
+        mHandlerThread = new HandlerThread("GuestResumeSessionReceiver");
+        mHandlerThread.start();
     }
 
     /**
      * Register this receiver with the {@link BroadcastDispatcher}
      */
     public void register() {
-        mUserTracker.addCallback(mUserChangedCallback, mMainExecutor);
+        mUserTracker.addCallback(mUserChangedCallback,
+                  new HandlerExecutor(mHandlerThread.getThreadHandler()));
     }
 
     private void cancelDialog() {
diff --git a/packages/SystemUI/src/com/android/systemui/media/controls/resume/MediaResumeListener.kt b/packages/SystemUI/src/com/android/systemui/media/controls/resume/MediaResumeListener.kt
index 23ee00d..a3029b2 100644
--- a/packages/SystemUI/src/com/android/systemui/media/controls/resume/MediaResumeListener.kt
+++ b/packages/SystemUI/src/com/android/systemui/media/controls/resume/MediaResumeListener.kt
@@ -146,7 +146,7 @@
                 null,
                 UserHandle.ALL
             )
-            userTracker.addCallback(userTrackerCallback, mainExecutor)
+            userTracker.addCallback(userTrackerCallback, backgroundExecutor)
             loadSavedComponents()
         }
     }
diff --git a/packages/SystemUI/src/com/android/systemui/power/PowerUI.java b/packages/SystemUI/src/com/android/systemui/power/PowerUI.java
index 5a1ad96..b3e0b3f 100644
--- a/packages/SystemUI/src/com/android/systemui/power/PowerUI.java
+++ b/packages/SystemUI/src/com/android/systemui/power/PowerUI.java
@@ -26,6 +26,8 @@
 import android.database.ContentObserver;
 import android.os.BatteryManager;
 import android.os.Handler;
+import android.os.HandlerExecutor;
+import android.os.HandlerThread;
 import android.os.IThermalEventListener;
 import android.os.IThermalService;
 import android.os.PowerManager;
@@ -92,6 +94,7 @@
     private Future mLastShowWarningTask;
     private boolean mEnableSkinTemperatureWarning;
     private boolean mEnableUsbTemperatureAlarm;
+    private final HandlerThread mHandlerThread;
 
     private int mLowBatteryAlertCloseLevel;
     private final int[] mLowBatteryReminderLevels = new int[2];
@@ -150,6 +153,8 @@
         mPowerManager = powerManager;
         mWakefulnessLifecycle = wakefulnessLifecycle;
         mUserTracker = userTracker;
+        mHandlerThread = new HandlerThread("PowerUI");
+        mHandlerThread.start();
     }
 
     public void start() {
@@ -168,7 +173,8 @@
                 false, obs, UserHandle.USER_ALL);
         updateBatteryWarningLevels();
         mReceiver.init();
-        mUserTracker.addCallback(mUserChangedCallback, mContext.getMainExecutor());
+        mUserTracker.addCallback(mUserChangedCallback,
+                    new HandlerExecutor(mHandlerThread.getThreadHandler()));
         mWakefulnessLifecycle.addObserver(mWakefulnessObserver);
 
         // Check to see if we need to let the user know that the phone previously shut down due
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/connectivity/NetworkControllerImpl.java b/packages/SystemUI/src/com/android/systemui/statusbar/connectivity/NetworkControllerImpl.java
index f381b37..04dbe10 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/connectivity/NetworkControllerImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/connectivity/NetworkControllerImpl.java
@@ -348,7 +348,7 @@
         // AIRPLANE_MODE_CHANGED is sent at boot; we've probably already missed it
         updateAirplaneMode(true /* force callback */);
         mUserTracker = userTracker;
-        mUserTracker.addCallback(mUserChangedCallback, new HandlerExecutor(mMainHandler));
+        mUserTracker.addCallback(mUserChangedCallback, mBgExecutor);
 
         deviceProvisionedController.addCallback(new DeviceProvisionedListener() {
             @Override
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/interruption/KeyguardNotificationVisibilityProvider.kt b/packages/SystemUI/src/com/android/systemui/statusbar/notification/interruption/KeyguardNotificationVisibilityProvider.kt
index b2c32cd..2d935bd 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/interruption/KeyguardNotificationVisibilityProvider.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/interruption/KeyguardNotificationVisibilityProvider.kt
@@ -7,6 +7,7 @@
 import android.net.Uri
 import android.os.Handler
 import android.os.HandlerExecutor
+import android.os.HandlerThread
 import android.os.UserHandle
 import android.provider.Settings
 import com.android.keyguard.KeyguardUpdateMonitor
@@ -84,6 +85,7 @@
             secureSettings.getUriFor(Settings.Secure.LOCK_SCREEN_SHOW_SILENT_NOTIFICATIONS)
     private val onStateChangedListeners = ListenerSet<Consumer<String>>()
     private var hideSilentNotificationsOnLockscreen: Boolean = false
+    private val handlerThread: HandlerThread = HandlerThread("KeyguardNotificationVis")
 
     private val userTrackerCallback = object : UserTracker.Callback {
         override fun onUserChanged(newUser: Int, userContext: Context) {
@@ -151,7 +153,9 @@
                 notifyStateChanged("onStatusBarUpcomingStateChanged")
             }
         })
-        userTracker.addCallback(userTrackerCallback, HandlerExecutor(handler))
+        handlerThread.start()
+        userTracker.addCallback(userTrackerCallback,
+                   HandlerExecutor(handlerThread.getThreadHandler()))
     }
 
     override fun addOnStateChangedListener(listener: Consumer<String>) {
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/policy/Clock.java b/packages/SystemUI/src/com/android/systemui/statusbar/policy/Clock.java
index ea7bcf2..fe58c64 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/policy/Clock.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/policy/Clock.java
@@ -28,6 +28,8 @@
 import android.icu.text.DateTimePatternGenerator;
 import android.os.Bundle;
 import android.os.Handler;
+import android.os.HandlerExecutor;
+import android.os.HandlerThread;
 import android.os.Parcelable;
 import android.os.SystemClock;
 import android.os.UserHandle;
@@ -106,6 +108,7 @@
     private final int mAmPmStyle;
     private boolean mShowSeconds;
     private Handler mSecondsHandler;
+    private HandlerThread mHandlerThread;
 
     // Fields to cache the width so the clock remains at an approximately constant width
     private int mCharsAtCurrentWidth = -1;
@@ -146,6 +149,8 @@
         }
         mBroadcastDispatcher = Dependency.get(BroadcastDispatcher.class);
         mUserTracker = Dependency.get(UserTracker.class);
+        mHandlerThread = new HandlerThread("Clock");
+        mHandlerThread.start();
 
         setIncludeFontPadding(false);
     }
@@ -205,7 +210,8 @@
             Dependency.get(TunerService.class).addTunable(this, CLOCK_SECONDS,
                     StatusBarIconController.ICON_HIDE_LIST);
             mCommandQueue.addCallback(this);
-            mUserTracker.addCallback(mUserChangedCallback, mContext.getMainExecutor());
+            mUserTracker.addCallback(mUserChangedCallback,
+                       new HandlerExecutor(mHandlerThread.getThreadHandler()));
             mCurrentUserId = mUserTracker.getUserId();
         }
 
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/policy/NextAlarmControllerImpl.java b/packages/SystemUI/src/com/android/systemui/statusbar/policy/NextAlarmControllerImpl.java
index 63b9ff9..740eed8 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/policy/NextAlarmControllerImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/policy/NextAlarmControllerImpl.java
@@ -21,6 +21,8 @@
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.os.HandlerExecutor;
+import android.os.HandlerThread;
 import android.os.UserHandle;
 
 import androidx.annotation.NonNull;
@@ -51,6 +53,7 @@
     private final UserTracker mUserTracker;
     private AlarmManager mAlarmManager;
     private AlarmManager.AlarmClockInfo mNextAlarm;
+    private HandlerThread mHandlerThread;
 
     private final UserTracker.Callback mUserChangedCallback =
             new UserTracker.Callback() {
@@ -75,7 +78,10 @@
         IntentFilter filter = new IntentFilter();
         filter.addAction(AlarmManager.ACTION_NEXT_ALARM_CLOCK_CHANGED);
         broadcastDispatcher.registerReceiver(this, filter, null, UserHandle.ALL);
-        mUserTracker.addCallback(mUserChangedCallback, mainExecutor);
+        mHandlerThread = new HandlerThread("NextAlarmControllerImpl");
+        mHandlerThread.start();
+        mUserTracker.addCallback(mUserChangedCallback,
+                    new HandlerExecutor(mHandlerThread.getThreadHandler()));
         updateNextAlarm();
     }
 
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/policy/SecurityControllerImpl.java b/packages/SystemUI/src/com/android/systemui/statusbar/policy/SecurityControllerImpl.java
index ada2196..46fe4f6 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/policy/SecurityControllerImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/policy/SecurityControllerImpl.java
@@ -157,7 +157,7 @@
         // TODO: re-register network callback on user change.
         mConnectivityManager.registerNetworkCallback(REQUEST, mNetworkCallback);
         onUserSwitched(mUserTracker.getUserId());
-        mUserTracker.addCallback(mUserChangedCallback, mMainExecutor);
+        mUserTracker.addCallback(mUserChangedCallback, mBgExecutor);
     }
 
     public void dump(PrintWriter pw, String[] args) {
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/policy/UserInfoControllerImpl.java b/packages/SystemUI/src/com/android/systemui/statusbar/policy/UserInfoControllerImpl.java
index a593d51..2453607 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/policy/UserInfoControllerImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/policy/UserInfoControllerImpl.java
@@ -38,7 +38,7 @@
 import com.android.settingslib.drawable.UserIconDrawable;
 import com.android.systemui.R;
 import com.android.systemui.dagger.SysUISingleton;
-import com.android.systemui.dagger.qualifiers.Main;
+import com.android.systemui.dagger.qualifiers.Background;
 import com.android.systemui.settings.UserTracker;
 
 import java.util.ArrayList;
@@ -66,11 +66,11 @@
     /**
      */
     @Inject
-    public UserInfoControllerImpl(Context context, @Main Executor mainExecutor,
+    public UserInfoControllerImpl(Context context, @Background Executor bgExecutor,
             UserTracker userTracker) {
         mContext = context;
         mUserTracker = userTracker;
-        mUserTracker.addCallback(mUserChangedCallback, mainExecutor);
+        mUserTracker.addCallback(mUserChangedCallback, bgExecutor);
 
         IntentFilter profileFilter = new IntentFilter();
         profileFilter.addAction(ContactsContract.Intents.ACTION_PROFILE_CHANGED);
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/policy/ZenModeControllerImpl.java b/packages/SystemUI/src/com/android/systemui/statusbar/policy/ZenModeControllerImpl.java
index dabdcc5..179b1b9 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/policy/ZenModeControllerImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/policy/ZenModeControllerImpl.java
@@ -28,6 +28,7 @@
 import android.net.Uri;
 import android.os.Handler;
 import android.os.HandlerExecutor;
+import android.os.HandlerThread;
 import android.os.Trace;
 import android.os.UserHandle;
 import android.os.UserManager;
@@ -80,6 +81,7 @@
     private volatile int mZenMode;
     private long mZenUpdateTime;
     private NotificationManager.Policy mConsolidatedNotificationPolicy;
+    private HandlerThread mHandlerThread;
 
     private final UserTracker.Callback mUserChangedCallback =
             new UserTracker.Callback() {
@@ -132,6 +134,8 @@
                 }
             }
         };
+        mHandlerThread = new HandlerThread("ZenModeControllerImpl");
+        mHandlerThread.start();
         mNoMan = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
         globalSettings.registerContentObserver(Global.ZEN_MODE, modeContentObserver);
         updateZenMode(getModeSettingValueFromProvider());
@@ -142,7 +146,8 @@
         mSetupObserver = new SetupObserver(handler);
         mSetupObserver.register();
         mUserManager = context.getSystemService(UserManager.class);
-        mUserTracker.addCallback(mUserChangedCallback, new HandlerExecutor(handler));
+        mUserTracker.addCallback(mUserChangedCallback,
+                    new HandlerExecutor(mHandlerThread.getThreadHandler()));
 
         dumpManager.registerDumpable(getClass().getSimpleName(), this);
     }
diff --git a/packages/SystemUI/src/com/android/systemui/theme/ThemeOverlayController.java b/packages/SystemUI/src/com/android/systemui/theme/ThemeOverlayController.java
index 5a9f5d5..b6e6269 100644
--- a/packages/SystemUI/src/com/android/systemui/theme/ThemeOverlayController.java
+++ b/packages/SystemUI/src/com/android/systemui/theme/ThemeOverlayController.java
@@ -460,7 +460,7 @@
             return;
         }
 
-        mUserTracker.addCallback(mUserTrackerCallback, mMainExecutor);
+        mUserTracker.addCallback(mUserTrackerCallback, mBgExecutor);
 
         mDeviceProvisionedController.addCallback(mDeviceProvisionedListener);
 
diff --git a/packages/SystemUI/src/com/android/systemui/tuner/TunerServiceImpl.java b/packages/SystemUI/src/com/android/systemui/tuner/TunerServiceImpl.java
index ccc0a79..453fbcb 100644
--- a/packages/SystemUI/src/com/android/systemui/tuner/TunerServiceImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/tuner/TunerServiceImpl.java
@@ -26,6 +26,7 @@
 import android.net.Uri;
 import android.os.Handler;
 import android.os.HandlerExecutor;
+import android.os.HandlerThread;
 import android.os.Looper;
 import android.os.UserManager;
 import android.provider.Settings;
@@ -95,6 +96,7 @@
     private UserTracker.Callback mCurrentUserTracker;
     private UserTracker mUserTracker;
     private final ComponentName mTunerComponent;
+    private HandlerThread mHandlerThread;
 
     /**
      */
@@ -112,7 +114,8 @@
         mDemoModeController = demoModeController;
         mUserTracker = userTracker;
         mTunerComponent = new ComponentName(mContext, TunerActivity.class);
-
+        mHandlerThread = new HandlerThread("TunerServiceImpl");
+        mHandlerThread.start();
         for (UserInfo user : UserManager.get(mContext).getUsers()) {
             mCurrentUser = user.getUserHandle().getIdentifier();
             if (getValue(TUNER_VERSION, 0) != CURRENT_TUNER_VERSION) {
@@ -130,7 +133,7 @@
             }
         };
         mUserTracker.addCallback(mCurrentUserTracker,
-                new HandlerExecutor(mainHandler));
+                new HandlerExecutor(mHandlerThread.getThreadHandler()));
     }
 
     @Override
diff --git a/packages/SystemUI/src/com/android/systemui/user/data/repository/UserRepository.kt b/packages/SystemUI/src/com/android/systemui/user/data/repository/UserRepository.kt
index 954765c..8d5cc88 100644
--- a/packages/SystemUI/src/com/android/systemui/user/data/repository/UserRepository.kt
+++ b/packages/SystemUI/src/com/android/systemui/user/data/repository/UserRepository.kt
@@ -208,7 +208,7 @@
                         }
                     }
 
-                tracker.addCallback(callback, mainDispatcher.asExecutor())
+                tracker.addCallback(callback, backgroundDispatcher.asExecutor())
                 send(currentSelectionStatus)
 
                 awaitClose { tracker.removeCallback(callback) }
diff --git a/packages/SystemUI/src/com/android/systemui/wmshell/WMShell.java b/packages/SystemUI/src/com/android/systemui/wmshell/WMShell.java
index 6fafcd5..931a98f 100644
--- a/packages/SystemUI/src/com/android/systemui/wmshell/WMShell.java
+++ b/packages/SystemUI/src/com/android/systemui/wmshell/WMShell.java
@@ -32,6 +32,8 @@
 import android.content.res.Configuration;
 import android.graphics.Rect;
 import android.inputmethodservice.InputMethodService;
+import android.os.HandlerExecutor;
+import android.os.HandlerThread;
 import android.os.IBinder;
 import android.view.Display;
 import android.view.KeyEvent;
@@ -121,6 +123,7 @@
     private final DisplayTracker mDisplayTracker;
     private final NoteTaskInitializer mNoteTaskInitializer;
     private final Executor mSysUiMainExecutor;
+    private HandlerThread mHandlerThread;
 
     // Listeners and callbacks. Note that we prefer member variable over anonymous class here to
     // avoid the situation that some implementations, like KeyguardUpdateMonitor, use WeakReference
@@ -200,6 +203,8 @@
         mDisplayTracker = displayTracker;
         mNoteTaskInitializer = noteTaskInitializer;
         mSysUiMainExecutor = sysUiMainExecutor;
+        mHandlerThread = new HandlerThread("WMShell");
+        mHandlerThread.start();
     }
 
     @Override
@@ -213,7 +218,8 @@
         mKeyguardUpdateMonitor.registerCallback(mKeyguardUpdateMonitorCallback);
 
         // Subscribe to user changes
-        mUserTracker.addCallback(mUserChangedCallback, mContext.getMainExecutor());
+        mUserTracker.addCallback(mUserChangedCallback,
+                     new HandlerExecutor(mHandlerThread.getThreadHandler()));
 
         mCommandQueue.addCallback(this);
         mPipOptional.ifPresent(this::initPip);
diff --git a/packages/SystemUI/tests/src/com/android/systemui/theme/ThemeOverlayControllerTest.java b/packages/SystemUI/tests/src/com/android/systemui/theme/ThemeOverlayControllerTest.java
index c454b45..487f582 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/theme/ThemeOverlayControllerTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/theme/ThemeOverlayControllerTest.java
@@ -172,7 +172,7 @@
 
         mWakefulnessLifecycle.dispatchFinishedWakingUp();
         mThemeOverlayController.start();
-        verify(mUserTracker).addCallback(mUserTrackerCallback.capture(), eq(mMainExecutor));
+        verify(mUserTracker).addCallback(mUserTrackerCallback.capture(), eq(mBgExecutor));
         verify(mWallpaperManager).addOnColorsChangedListener(mColorsListener.capture(), eq(null),
                 eq(UserHandle.USER_ALL));
         verify(mBroadcastDispatcher).registerReceiver(mBroadcastReceiver.capture(), any(),