/*
 * Copyright (C) 2015 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.am;

import static android.Manifest.permission.INTERACT_ACROSS_PROFILES;
import static android.Manifest.permission.INTERACT_ACROSS_USERS;
import static android.Manifest.permission.INTERACT_ACROSS_USERS_FULL;
import static android.app.ActivityManager.USER_OP_ERROR_IS_SYSTEM;
import static android.app.ActivityManager.USER_OP_ERROR_RELATED_USERS_CANNOT_STOP;
import static android.app.ActivityManager.USER_OP_IS_CURRENT;
import static android.app.ActivityManager.USER_OP_SUCCESS;
import static android.app.ActivityManagerInternal.ALLOW_ALL_PROFILE_PERMISSIONS_IN_PROFILE;
import static android.app.ActivityManagerInternal.ALLOW_FULL_ONLY;
import static android.app.ActivityManagerInternal.ALLOW_NON_FULL;
import static android.app.ActivityManagerInternal.ALLOW_NON_FULL_IN_PROFILE;
import static android.os.Process.SHELL_UID;
import static android.os.Process.SYSTEM_UID;

import static com.android.internal.util.FrameworkStatsLog.BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__FRAMEWORK_LOCKED_BOOT_COMPLETED;
import static com.android.server.am.ActivityManagerDebugConfig.DEBUG_MU;
import static com.android.server.am.ActivityManagerDebugConfig.TAG_AM;
import static com.android.server.am.ActivityManagerDebugConfig.TAG_WITH_CLASS_NAME;
import static com.android.server.am.ActivityManagerService.MY_PID;
import static com.android.server.am.UserState.STATE_BOOTING;
import static com.android.server.am.UserState.STATE_RUNNING_LOCKED;
import static com.android.server.am.UserState.STATE_RUNNING_UNLOCKED;
import static com.android.server.am.UserState.STATE_RUNNING_UNLOCKING;

import android.annotation.IntDef;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.annotation.UserIdInt;
import android.app.ActivityManager;
import android.app.AppGlobals;
import android.app.AppOpsManager;
import android.app.Dialog;
import android.app.IStopUserCallback;
import android.app.IUserSwitchObserver;
import android.app.KeyguardManager;
import android.app.usage.UsageEvents;
import android.appwidget.AppWidgetManagerInternal;
import android.content.Context;
import android.content.IIntentReceiver;
import android.content.Intent;
import android.content.PermissionChecker;
import android.content.pm.IPackageManager;
import android.content.pm.PackageManager;
import android.content.pm.UserInfo;
import android.os.BatteryStats;
import android.os.Binder;
import android.os.Build;
import android.os.Bundle;
import android.os.Debug;
import android.os.Handler;
import android.os.IBinder;
import android.os.IProgressListener;
import android.os.IRemoteCallback;
import android.os.IUserManager;
import android.os.Looper;
import android.os.Message;
import android.os.Process;
import android.os.RemoteCallbackList;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.os.SystemClock;
import android.os.UserHandle;
import android.os.UserManager;
import android.os.UserManagerInternal;
import android.os.storage.IStorageManager;
import android.os.storage.StorageManager;
import android.text.format.DateUtils;
import android.util.ArraySet;
import android.util.EventLog;
import android.util.IntArray;
import android.util.Pair;
import android.util.Slog;
import android.util.SparseArray;
import android.util.SparseIntArray;
import android.util.proto.ProtoOutputStream;

import com.android.internal.R;
import com.android.internal.annotations.GuardedBy;
import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.util.ArrayUtils;
import com.android.internal.util.FrameworkStatsLog;
import com.android.internal.widget.LockPatternUtils;
import com.android.server.FgThread;
import com.android.server.LocalServices;
import com.android.server.SystemServiceManager;
import com.android.server.am.UserState.KeyEvictedCallback;
import com.android.server.pm.UserManagerService;
import com.android.server.utils.TimingsTraceAndSlog;
import com.android.server.wm.ActivityTaskManagerInternal;
import com.android.server.wm.WindowManagerService;

import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Helper class for {@link ActivityManagerService} responsible for multi-user functionality.
 *
 * <p>This class use {@link #mLock} to synchronize access to internal state. Methods that require
 * {@link #mLock} to be held should have "LU" suffix in the name.
 *
 * <p><strong>Important:</strong> Synchronized code, i.e. one executed inside a synchronized(mLock)
 * block or inside LU method, should only access internal state of this class or make calls to
 * other LU methods. Non-LU method calls or calls to external classes are discouraged as they
 * may cause lock inversion.
 */
class UserController implements Handler.Callback {
    private static final String TAG = TAG_WITH_CLASS_NAME ? "UserController" : TAG_AM;

    // Amount of time we wait for observers to handle a user switch before
    // giving up on them and unfreezing the screen.
    static final int USER_SWITCH_TIMEOUT_MS = 3 * 1000;

    // Amount of time we wait for observers to handle a user switch before we log a warning.
    // Must be smaller than USER_SWITCH_TIMEOUT_MS.
    private static final int USER_SWITCH_WARNING_TIMEOUT_MS = 500;

    // ActivityManager thread message constants
    static final int REPORT_USER_SWITCH_MSG = 10;
    static final int CONTINUE_USER_SWITCH_MSG = 20;
    static final int USER_SWITCH_TIMEOUT_MSG = 30;
    static final int START_PROFILES_MSG = 40;
    static final int USER_START_MSG = 50;
    static final int USER_CURRENT_MSG = 60;
    static final int FOREGROUND_PROFILE_CHANGED_MSG = 70;
    static final int REPORT_USER_SWITCH_COMPLETE_MSG = 80;
    static final int USER_SWITCH_CALLBACKS_TIMEOUT_MSG = 90;
    static final int USER_UNLOCK_MSG = 100;
    static final int USER_UNLOCKED_MSG = 105;
    static final int REPORT_LOCKED_BOOT_COMPLETE_MSG = 110;
    static final int START_USER_SWITCH_FG_MSG = 120;

    // Message constant to clear {@link UserJourneySession} from {@link mUserIdToUserJourneyMap} if
    // the user journey, defined in the UserLifecycleJourneyReported atom for statsd, is not
    // complete within {@link USER_JOURNEY_TIMEOUT}.
    private static final int CLEAR_USER_JOURNEY_SESSION_MSG = 200;
    // Wait time for completing the user journey. If a user journey is not complete within this
    // time, the remaining lifecycle events for the journey would not be logged in statsd.
    // Timeout set for 90 seconds.
    private static final int USER_JOURNEY_TIMEOUT_MS = 90_000;

    // UI thread message constants
    static final int START_USER_SWITCH_UI_MSG = 1000;

    // If a callback wasn't called within USER_SWITCH_CALLBACKS_TIMEOUT_MS after
    // USER_SWITCH_TIMEOUT_MS, an error is reported. Usually it indicates a problem in the observer
    // when it never calls back.
    private static final int USER_SWITCH_CALLBACKS_TIMEOUT_MS = 5 * 1000;

    // Used for statsd logging with UserLifecycleJourneyReported + UserLifecycleEventOccurred atoms
    private static final long INVALID_SESSION_ID = 0;

    // The various user journeys, defined in the UserLifecycleJourneyReported atom for statsd
    private static final int USER_JOURNEY_UNKNOWN =
            FrameworkStatsLog.USER_LIFECYCLE_JOURNEY_REPORTED__JOURNEY__UNKNOWN;
    private static final int USER_JOURNEY_USER_SWITCH_FG =
            FrameworkStatsLog.USER_LIFECYCLE_JOURNEY_REPORTED__JOURNEY__USER_SWITCH_FG;
    private static final int USER_JOURNEY_USER_SWITCH_UI =
            FrameworkStatsLog.USER_LIFECYCLE_JOURNEY_REPORTED__JOURNEY__USER_SWITCH_UI;
    private static final int USER_JOURNEY_USER_START =
            FrameworkStatsLog.USER_LIFECYCLE_JOURNEY_REPORTED__JOURNEY__USER_START;
    private static final int USER_JOURNEY_USER_CREATE =
            FrameworkStatsLog.USER_LIFECYCLE_JOURNEY_REPORTED__JOURNEY__USER_CREATE;
    @IntDef(prefix = { "USER_JOURNEY" }, value = {
            USER_JOURNEY_UNKNOWN,
            USER_JOURNEY_USER_SWITCH_FG,
            USER_JOURNEY_USER_SWITCH_UI,
            USER_JOURNEY_USER_START,
            USER_JOURNEY_USER_CREATE,
    })
    @interface UserJourney {}

    // The various user lifecycle events, defined in the UserLifecycleEventOccurred atom for statsd
    private static final int USER_LIFECYCLE_EVENT_UNKNOWN =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__EVENT__UNKNOWN;
    private static final int USER_LIFECYCLE_EVENT_SWITCH_USER =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__EVENT__SWITCH_USER;
    private static final int USER_LIFECYCLE_EVENT_START_USER =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__EVENT__START_USER;
    private static final int USER_LIFECYCLE_EVENT_CREATE_USER =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__EVENT__CREATE_USER;
    private static final int USER_LIFECYCLE_EVENT_USER_RUNNING_LOCKED =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__EVENT__USER_RUNNING_LOCKED;
    private static final int USER_LIFECYCLE_EVENT_UNLOCKING_USER =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__EVENT__UNLOCKING_USER;
    private static final int USER_LIFECYCLE_EVENT_UNLOCKED_USER =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__EVENT__UNLOCKED_USER;
    @IntDef(prefix = { "USER_LIFECYCLE_EVENT" }, value = {
            USER_LIFECYCLE_EVENT_UNKNOWN,
            USER_LIFECYCLE_EVENT_SWITCH_USER,
            USER_LIFECYCLE_EVENT_START_USER,
            USER_LIFECYCLE_EVENT_CREATE_USER,
            USER_LIFECYCLE_EVENT_USER_RUNNING_LOCKED,
            USER_LIFECYCLE_EVENT_UNLOCKING_USER,
            USER_LIFECYCLE_EVENT_UNLOCKED_USER,
    })
    @interface UserLifecycleEvent {}

    // User lifecyle event state, defined in the UserLifecycleEventOccurred atom for statsd
    private static final int USER_LIFECYCLE_EVENT_STATE_BEGIN =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__STATE__BEGIN;
    private static final int USER_LIFECYCLE_EVENT_STATE_FINISH =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__STATE__FINISH;
    private static final int USER_LIFECYCLE_EVENT_STATE_NONE =
            FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED__STATE__NONE;
    @IntDef(prefix = { "USER_LIFECYCLE_EVENT_STATE" }, value = {
            USER_LIFECYCLE_EVENT_STATE_BEGIN,
            USER_LIFECYCLE_EVENT_STATE_FINISH,
            USER_LIFECYCLE_EVENT_STATE_NONE,
    })
    @interface UserLifecycleEventState {}

    /**
     * Maximum number of users we allow to be running at a time, including system user.
     *
     * <p>This parameter only affects how many background users will be stopped when switching to a
     * new user. It has no impact on {@link #startUser(int, boolean)} behavior.
     *
     * <p>Note: Current and system user (and their related profiles) are never stopped when
     * switching users. Due to that, the actual number of running users can exceed mMaxRunningUsers
     */
    @GuardedBy("mLock")
    private int mMaxRunningUsers;

    // Lock for internal state.
    private final Object mLock = new Object();

    private final Injector mInjector;
    private final Handler mHandler;
    private final Handler mUiHandler;

    // Holds the current foreground user's id. Use mLock when updating
    @GuardedBy("mLock")
    private volatile int mCurrentUserId = UserHandle.USER_SYSTEM;
    // Holds the target user's id during a user switch. The value of mCurrentUserId will be updated
    // once target user goes into the foreground. Use mLock when updating
    @GuardedBy("mLock")
    private volatile int mTargetUserId = UserHandle.USER_NULL;

    /**
     * Which users have been started, so are allowed to run code.
     */
    @GuardedBy("mLock")
    private final SparseArray<UserState> mStartedUsers = new SparseArray<>();

    /**
     * LRU list of history of current users.  Most recently current is at the end.
     */
    @GuardedBy("mLock")
    private final ArrayList<Integer> mUserLru = new ArrayList<>();

    /**
     * Constant array of the users that are currently started.
     */
    @GuardedBy("mLock")
    private int[] mStartedUserArray = new int[] { 0 };

    // If there are multiple profiles for the current user, their ids are here
    // Currently only the primary user can have managed profiles
    @GuardedBy("mLock")
    private int[] mCurrentProfileIds = new int[] {};

    /**
     * Mapping from each known user ID to the profile group ID it is associated with.
     */
    @GuardedBy("mLock")
    private final SparseIntArray mUserProfileGroupIds = new SparseIntArray();

    /**
     * Registered observers of the user switching mechanics.
     */
    private final RemoteCallbackList<IUserSwitchObserver> mUserSwitchObservers
            = new RemoteCallbackList<>();

    @GuardedBy("mLock")
    private boolean mUserSwitchUiEnabled = true;

    /**
     * Currently active user switch callbacks.
     */
    @GuardedBy("mLock")
    private volatile ArraySet<String> mCurWaitingUserSwitchCallbacks;

    /**
     * Messages for for switching from {@link android.os.UserHandle#SYSTEM}.
     */
    @GuardedBy("mLock")
    private String mSwitchingFromSystemUserMessage;

    /**
     * Messages for for switching to {@link android.os.UserHandle#SYSTEM}.
     */
    @GuardedBy("mLock")
    private String mSwitchingToSystemUserMessage;

    /**
     * Callbacks that are still active after {@link #USER_SWITCH_TIMEOUT_MS}
     */
    @GuardedBy("mLock")
    private ArraySet<String> mTimeoutUserSwitchCallbacks;

    private final LockPatternUtils mLockPatternUtils;

    volatile boolean mBootCompleted;

    /**
     * In this mode, user is always stopped when switched out but locking of user data is
     * postponed until total number of unlocked users in the system reaches mMaxRunningUsers.
     * Once total number of unlocked users reach mMaxRunningUsers, least recently used user
     * will be locked.
     */
    @GuardedBy("mLock")
    private boolean mDelayUserDataLocking;
    /**
     * Keep track of last active users for mDelayUserDataLocking.
     * The latest stopped user is placed in front while the least recently stopped user in back.
     */
    @GuardedBy("mLock")
    private final ArrayList<Integer> mLastActiveUsers = new ArrayList<>();

    /**
     * {@link UserIdInt} to {@link UserJourneySession} mapping used for statsd logging for the
     * UserLifecycleJourneyReported and UserLifecycleEventOccurred atoms.
     */
    @GuardedBy("mUserIdToUserJourneyMap")
    private final SparseArray<UserJourneySession> mUserIdToUserJourneyMap = new SparseArray<>();

    /**
     * Sets on {@link #setInitialConfig(boolean, int, boolean)}, which is called by
     * {@code ActivityManager} when the system is started.
     *
     * <p>It's useful to ignore external operations (i.e., originated outside {@code system_server},
     * like from {@code adb shell am switch-user})) that could happen before such call is made and
     * the system is ready.
     */
    @GuardedBy("mLock")
    private boolean mInitialized;

    UserController(ActivityManagerService service) {
        this(new Injector(service));
    }

    @VisibleForTesting
    UserController(Injector injector) {
        mInjector = injector;
        mHandler = mInjector.getHandler(this);
        mUiHandler = mInjector.getUiHandler(this);
        // User 0 is the first and only user that runs at boot.
        final UserState uss = new UserState(UserHandle.SYSTEM);
        uss.mUnlockProgress.addListener(new UserProgressListener());
        mStartedUsers.put(UserHandle.USER_SYSTEM, uss);
        mUserLru.add(UserHandle.USER_SYSTEM);
        mLockPatternUtils = mInjector.getLockPatternUtils();
        updateStartedUserArrayLU();
    }

    void setInitialConfig(boolean userSwitchUiEnabled, int maxRunningUsers,
            boolean delayUserDataLocking) {
        synchronized (mLock) {
            mUserSwitchUiEnabled = userSwitchUiEnabled;
            mMaxRunningUsers = maxRunningUsers;
            mDelayUserDataLocking = delayUserDataLocking;
            mInitialized = true;
        }
    }

    private boolean isUserSwitchUiEnabled() {
        synchronized (mLock) {
            return mUserSwitchUiEnabled;
        }
    }

    int getMaxRunningUsers() {
        synchronized (mLock) {
            return mMaxRunningUsers;
        }
    }

    private boolean isDelayUserDataLockingEnabled() {
        synchronized (mLock) {
            return mDelayUserDataLocking;
        }
    }

    void finishUserSwitch(UserState uss) {
        // This call holds the AM lock so we post to the handler.
        mHandler.post(() -> {
            finishUserBoot(uss);
            startProfiles();
            synchronized (mLock) {
                stopRunningUsersLU(mMaxRunningUsers);
            }
        });
    }

    @GuardedBy("mLock")
    List<Integer> getRunningUsersLU() {
        ArrayList<Integer> runningUsers = new ArrayList<>();
        for (Integer userId : mUserLru) {
            UserState uss = mStartedUsers.get(userId);
            if (uss == null) {
                // Shouldn't happen, but be sane if it does.
                continue;
            }
            if (uss.state == UserState.STATE_STOPPING
                    || uss.state == UserState.STATE_SHUTDOWN) {
                // This user is already stopping, doesn't count.
                continue;
            }
            if (userId == UserHandle.USER_SYSTEM) {
                // We only count system user as running when it is not a pure system user.
                if (UserInfo.isSystemOnly(userId)) {
                    continue;
                }
            }
            runningUsers.add(userId);
        }
        return runningUsers;
    }

    @GuardedBy("mLock")
    void stopRunningUsersLU(int maxRunningUsers) {
        List<Integer> currentlyRunning = getRunningUsersLU();
        Iterator<Integer> iterator = currentlyRunning.iterator();
        while (currentlyRunning.size() > maxRunningUsers && iterator.hasNext()) {
            Integer userId = iterator.next();
            if (userId == UserHandle.USER_SYSTEM || userId == mCurrentUserId) {
                // Owner/System user and current user can't be stopped
                continue;
            }
            // allowDelayedLocking set here as stopping user is done without any explicit request
            // from outside.
            if (stopUsersLU(userId, /* force= */ false, /* allowDelayedLocking= */ true,
                    /* stopUserCallback= */ null, /* keyEvictedCallback= */ null)
                    == USER_OP_SUCCESS) {
                iterator.remove();
            }
        }
    }

    /**
     * Returns if more users can be started without stopping currently running users.
     */
    boolean canStartMoreUsers() {
        synchronized (mLock) {
            return getRunningUsersLU().size() < mMaxRunningUsers;
        }
    }

    private void finishUserBoot(UserState uss) {
        finishUserBoot(uss, null);
    }

    private void finishUserBoot(UserState uss, IIntentReceiver resultTo) {
        final int userId = uss.mHandle.getIdentifier();
        EventLog.writeEvent(EventLogTags.UC_FINISH_USER_BOOT, userId);

        synchronized (mLock) {
            // Bail if we ended up with a stale user
            if (mStartedUsers.get(userId) != uss) {
                return;
            }
        }

        // We always walk through all the user lifecycle states to send
        // consistent developer events. We step into RUNNING_LOCKED here,
        // but we might immediately step into RUNNING below if the user
        // storage is already unlocked.
        if (uss.setState(STATE_BOOTING, STATE_RUNNING_LOCKED)) {
            logUserLifecycleEvent(userId, USER_LIFECYCLE_EVENT_USER_RUNNING_LOCKED,
                    USER_LIFECYCLE_EVENT_STATE_NONE);
            mInjector.getUserManagerInternal().setUserState(userId, uss.state);
            // Do not report secondary users, runtime restarts or first boot/upgrade
            if (userId == UserHandle.USER_SYSTEM
                    && !mInjector.isRuntimeRestarted() && !mInjector.isFirstBootOrUpgrade()) {
                final long elapsedTimeMs = SystemClock.elapsedRealtime();
                FrameworkStatsLog.write(FrameworkStatsLog.BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
                        BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__FRAMEWORK_LOCKED_BOOT_COMPLETED,
                        elapsedTimeMs);
                final long maxElapsedTimeMs = 120_000;
                if (elapsedTimeMs > maxElapsedTimeMs) {
                    Slog.wtf("SystemServerTiming",
                            "finishUserBoot took too long. elapsedTimeMs=" + elapsedTimeMs);
                }
            }

            if (!mInjector.getUserManager().isPreCreated(userId)) {
                mHandler.sendMessage(mHandler.obtainMessage(REPORT_LOCKED_BOOT_COMPLETE_MSG,
                        userId, 0));
                Intent intent = new Intent(Intent.ACTION_LOCKED_BOOT_COMPLETED, null);
                intent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
                intent.addFlags(Intent.FLAG_RECEIVER_NO_ABORT
                        | Intent.FLAG_RECEIVER_OFFLOAD
                        | Intent.FLAG_RECEIVER_INCLUDE_BACKGROUND);
                mInjector.broadcastIntent(intent, null, resultTo, 0, null, null,
                        new String[]{android.Manifest.permission.RECEIVE_BOOT_COMPLETED},
                        AppOpsManager.OP_NONE, null, true, false, MY_PID, SYSTEM_UID,
                        Binder.getCallingUid(), Binder.getCallingPid(), userId);
            }
        }

        // We need to delay unlocking managed profiles until the parent user
        // is also unlocked.
        if (mInjector.getUserManager().isProfile(userId)) {
            final UserInfo parent = mInjector.getUserManager().getProfileParent(userId);
            if (parent != null
                    && isUserRunning(parent.id, ActivityManager.FLAG_AND_UNLOCKED)) {
                Slog.d(TAG, "User " + userId + " (parent " + parent.id
                        + "): attempting unlock because parent is unlocked");
                maybeUnlockUser(userId);
            } else {
                String parentId = (parent == null) ? "<null>" : String.valueOf(parent.id);
                Slog.d(TAG, "User " + userId + " (parent " + parentId
                        + "): delaying unlock because parent is locked");
            }
        } else {
            maybeUnlockUser(userId);
        }
    }

    /**
     * Step from {@link UserState#STATE_RUNNING_LOCKED} to
     * {@link UserState#STATE_RUNNING_UNLOCKING}.
     */
    private boolean finishUserUnlocking(final UserState uss) {
        final int userId = uss.mHandle.getIdentifier();
        EventLog.writeEvent(EventLogTags.UC_FINISH_USER_UNLOCKING, userId);
        logUserLifecycleEvent(userId, USER_LIFECYCLE_EVENT_UNLOCKING_USER,
                USER_LIFECYCLE_EVENT_STATE_BEGIN);
        // Only keep marching forward if user is actually unlocked
        if (!StorageManager.isUserKeyUnlocked(userId)) return false;
        synchronized (mLock) {
            // Do not proceed if unexpected state or a stale user
            if (mStartedUsers.get(userId) != uss || uss.state != STATE_RUNNING_LOCKED) {
                return false;
            }
        }
        uss.mUnlockProgress.start();

        // Prepare app storage before we go any further
        uss.mUnlockProgress.setProgress(5,
                    mInjector.getContext().getString(R.string.android_start_title));

        // Call onBeforeUnlockUser on a worker thread that allows disk I/O
        FgThread.getHandler().post(() -> {
            if (!StorageManager.isUserKeyUnlocked(userId)) {
                Slog.w(TAG, "User key got locked unexpectedly, leaving user locked.");
                return;
            }
            mInjector.getUserManager().onBeforeUnlockUser(userId);
            synchronized (mLock) {
                // Do not proceed if unexpected state
                if (!uss.setState(STATE_RUNNING_LOCKED, STATE_RUNNING_UNLOCKING)) {
                    return;
                }
            }
            mInjector.getUserManagerInternal().setUserState(userId, uss.state);

            uss.mUnlockProgress.setProgress(20);

            // Dispatch unlocked to system services; when fully dispatched,
            // that calls through to the next "unlocked" phase
            mHandler.obtainMessage(USER_UNLOCK_MSG, userId, 0, uss).sendToTarget();
        });
        return true;
    }

    /**
     * Step from {@link UserState#STATE_RUNNING_UNLOCKING} to
     * {@link UserState#STATE_RUNNING_UNLOCKED}.
     */
    void finishUserUnlocked(final UserState uss) {
        final int userId = uss.mHandle.getIdentifier();
        EventLog.writeEvent(EventLogTags.UC_FINISH_USER_UNLOCKED, userId);
        // Only keep marching forward if user is actually unlocked
        if (!StorageManager.isUserKeyUnlocked(userId)) return;
        synchronized (mLock) {
            // Bail if we ended up with a stale user
            if (mStartedUsers.get(uss.mHandle.getIdentifier()) != uss) return;

            // Do not proceed if unexpected state
            if (!uss.setState(STATE_RUNNING_UNLOCKING, STATE_RUNNING_UNLOCKED)) {
                return;
            }
        }
        mInjector.getUserManagerInternal().setUserState(userId, uss.state);
        uss.mUnlockProgress.finish();

        // Get unaware persistent apps running and start any unaware providers
        // in already-running apps that are partially aware
        if (userId == UserHandle.USER_SYSTEM) {
            mInjector.startPersistentApps(PackageManager.MATCH_DIRECT_BOOT_UNAWARE);
        }
        mInjector.installEncryptionUnawareProviders(userId);

        // Dispatch unlocked to external apps
        final Intent unlockedIntent = new Intent(Intent.ACTION_USER_UNLOCKED);
        unlockedIntent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
        unlockedIntent.addFlags(
                Intent.FLAG_RECEIVER_REGISTERED_ONLY | Intent.FLAG_RECEIVER_FOREGROUND);
        mInjector.broadcastIntent(unlockedIntent, null, null, 0, null,
                null, null, AppOpsManager.OP_NONE, null, false, false, MY_PID, SYSTEM_UID,
                Binder.getCallingUid(), Binder.getCallingPid(), userId);

        if (getUserInfo(userId).isManagedProfile()) {
            UserInfo parent = mInjector.getUserManager().getProfileParent(userId);
            if (parent != null) {
                final Intent profileUnlockedIntent = new Intent(
                        Intent.ACTION_MANAGED_PROFILE_UNLOCKED);
                profileUnlockedIntent.putExtra(Intent.EXTRA_USER, UserHandle.of(userId));
                profileUnlockedIntent.addFlags(
                        Intent.FLAG_RECEIVER_REGISTERED_ONLY
                                | Intent.FLAG_RECEIVER_FOREGROUND);
                mInjector.broadcastIntent(profileUnlockedIntent,
                        null, null, 0, null, null, null, AppOpsManager.OP_NONE,
                        null, false, false, MY_PID, SYSTEM_UID, Binder.getCallingUid(),
                        Binder.getCallingPid(), parent.id);
            }
        }

        // Send PRE_BOOT broadcasts if user fingerprint changed; we
        // purposefully block sending BOOT_COMPLETED until after all
        // PRE_BOOT receivers are finished to avoid ANR'ing apps
        final UserInfo info = getUserInfo(userId);
        if (!Objects.equals(info.lastLoggedInFingerprint, Build.FINGERPRINT)) {
            // Suppress double notifications for managed profiles that
            // were unlocked automatically as part of their parent user
            // being unlocked.
            final boolean quiet;
            if (info.isManagedProfile()) {
                quiet = !uss.tokenProvided
                        || !mLockPatternUtils.isSeparateProfileChallengeEnabled(userId);
            } else {
                quiet = false;
            }
            mInjector.sendPreBootBroadcast(userId, quiet,
                    () -> finishUserUnlockedCompleted(uss));
        } else {
            finishUserUnlockedCompleted(uss);
        }
    }

    private void finishUserUnlockedCompleted(UserState uss) {
        final int userId = uss.mHandle.getIdentifier();
        EventLog.writeEvent(EventLogTags.UC_FINISH_USER_UNLOCKED_COMPLETED, userId);
        synchronized (mLock) {
            // Bail if we ended up with a stale user
            if (mStartedUsers.get(uss.mHandle.getIdentifier()) != uss) return;
        }
        UserInfo userInfo = getUserInfo(userId);
        if (userInfo == null) {
            return;
        }
        // Only keep marching forward if user is actually unlocked
        if (!StorageManager.isUserKeyUnlocked(userId)) return;

        // Remember that we logged in
        mInjector.getUserManager().onUserLoggedIn(userId);

        if (!userInfo.isInitialized()) {
            if (userId != UserHandle.USER_SYSTEM) {
                Slog.d(TAG, "Initializing user #" + userId);
                Intent intent = new Intent(Intent.ACTION_USER_INITIALIZE);
                intent.addFlags(Intent.FLAG_RECEIVER_FOREGROUND
                        | Intent.FLAG_RECEIVER_INCLUDE_BACKGROUND);
                mInjector.broadcastIntent(intent, null,
                        new IIntentReceiver.Stub() {
                            @Override
                            public void performReceive(Intent intent, int resultCode,
                                    String data, Bundle extras, boolean ordered,
                                    boolean sticky, int sendingUser) {
                                // Note: performReceive is called with mService lock held
                                mInjector.getUserManager().makeInitialized(userInfo.id);
                            }
                        }, 0, null, null, null, AppOpsManager.OP_NONE,
                        null, true, false, MY_PID, SYSTEM_UID, Binder.getCallingUid(),
                        Binder.getCallingPid(), userId);
            }
        }

        if (userInfo.preCreated) {
            Slog.i(TAG, "Stopping pre-created user " + userInfo.toFullString());
            // Pre-created user was started right after creation so services could properly
            // intialize it; it should be stopped right away as it's not really a "real" user.
            // TODO(b/143092698): in the long-term, it might be better to add a onCreateUser()
            // callback on SystemService instead.
            stopUser(userInfo.id, /* force= */ true, /* allowDelayedLocking= */ false,
                    /* stopUserCallback= */ null, /* keyEvictedCallback= */ null);
            return;
        }

        // Spin up app widgets prior to boot-complete, so they can be ready promptly
        mInjector.startUserWidgets(userId);

        mHandler.obtainMessage(USER_UNLOCKED_MSG, userId, 0).sendToTarget();

        Slog.i(TAG, "Posting BOOT_COMPLETED user #" + userId);
        // Do not report secondary users, runtime restarts or first boot/upgrade
        if (userId == UserHandle.USER_SYSTEM
                && !mInjector.isRuntimeRestarted() && !mInjector.isFirstBootOrUpgrade()) {
            final long elapsedTimeMs = SystemClock.elapsedRealtime();
            FrameworkStatsLog.write(FrameworkStatsLog.BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
                    FrameworkStatsLog.BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__FRAMEWORK_BOOT_COMPLETED,
                    elapsedTimeMs);
        }
        final Intent bootIntent = new Intent(Intent.ACTION_BOOT_COMPLETED, null);
        bootIntent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
        bootIntent.addFlags(Intent.FLAG_RECEIVER_NO_ABORT
                | Intent.FLAG_RECEIVER_INCLUDE_BACKGROUND
                | Intent.FLAG_RECEIVER_OFFLOAD);
        // Widget broadcasts are outbound via FgThread, so to guarantee sequencing
        // we also send the boot_completed broadcast from that thread.
        final int callingUid = Binder.getCallingUid();
        final int callingPid = Binder.getCallingPid();
        FgThread.getHandler().post(() -> {
            mInjector.broadcastIntent(bootIntent, null,
                    new IIntentReceiver.Stub() {
                        @Override
                        public void performReceive(Intent intent, int resultCode, String data,
                                Bundle extras, boolean ordered, boolean sticky, int sendingUser)
                                        throws RemoteException {
                            Slog.i(UserController.TAG, "Finished processing BOOT_COMPLETED for u"
                                    + userId);
                            mBootCompleted = true;
                        }
                    }, 0, null, null,
                    new String[]{android.Manifest.permission.RECEIVE_BOOT_COMPLETED},
                    AppOpsManager.OP_NONE, null, true, false, MY_PID, SYSTEM_UID,
                    callingUid, callingPid, userId);
        });
    }

    int restartUser(final int userId, final boolean foreground) {
        return stopUser(userId, /* force= */ true, /* allowDelayedLocking= */ false,
                /* stopUserCallback= */ null, new KeyEvictedCallback() {
            @Override
            public void keyEvicted(@UserIdInt int userId) {
                // Post to the same handler that this callback is called from to ensure the user
                // cleanup is complete before restarting.
                mHandler.post(() -> UserController.this.startUser(userId, foreground));
            }
        });
    }

    int stopUser(final int userId, final boolean force, boolean allowDelayedLocking,
            final IStopUserCallback stopUserCallback, KeyEvictedCallback keyEvictedCallback) {
        checkCallingPermission(INTERACT_ACROSS_USERS_FULL, "stopUser");
        if (userId < 0 || userId == UserHandle.USER_SYSTEM) {
            throw new IllegalArgumentException("Can't stop system user " + userId);
        }
        enforceShellRestriction(UserManager.DISALLOW_DEBUGGING_FEATURES, userId);
        synchronized (mLock) {
            return stopUsersLU(userId, force, allowDelayedLocking, stopUserCallback,
                    keyEvictedCallback);
        }
    }

    /**
     * Stops the user along with its related users. The method calls
     * {@link #getUsersToStopLU(int)} to determine the list of users that should be stopped.
     */
    @GuardedBy("mLock")
    private int stopUsersLU(final int userId, boolean force, boolean allowDelayedLocking,
            final IStopUserCallback stopUserCallback, KeyEvictedCallback keyEvictedCallback) {
        if (userId == UserHandle.USER_SYSTEM) {
            return USER_OP_ERROR_IS_SYSTEM;
        }
        if (isCurrentUserLU(userId)) {
            return USER_OP_IS_CURRENT;
        }
        int[] usersToStop = getUsersToStopLU(userId);
        // If one of related users is system or current, no related users should be stopped
        for (int i = 0; i < usersToStop.length; i++) {
            int relatedUserId = usersToStop[i];
            if ((UserHandle.USER_SYSTEM == relatedUserId) || isCurrentUserLU(relatedUserId)) {
                if (DEBUG_MU) Slog.i(TAG, "stopUsersLocked cannot stop related user "
                        + relatedUserId);
                // We still need to stop the requested user if it's a force stop.
                if (force) {
                    Slog.i(TAG,
                            "Force stop user " + userId + ". Related users will not be stopped");
                    stopSingleUserLU(userId, allowDelayedLocking, stopUserCallback,
                            keyEvictedCallback);
                    return USER_OP_SUCCESS;
                }
                return USER_OP_ERROR_RELATED_USERS_CANNOT_STOP;
            }
        }
        if (DEBUG_MU) Slog.i(TAG, "stopUsersLocked usersToStop=" + Arrays.toString(usersToStop));
        for (int userIdToStop : usersToStop) {
            stopSingleUserLU(userIdToStop, allowDelayedLocking,
                    userIdToStop == userId ? stopUserCallback : null,
                    userIdToStop == userId ? keyEvictedCallback : null);
        }
        return USER_OP_SUCCESS;
    }

    /**
     * Stops a single User. This can also trigger locking user data out depending on device's
     * config ({@code mDelayUserDataLocking}) and arguments.
     * User will be unlocked when
     * - {@code mDelayUserDataLocking} is not set.
     * - {@code mDelayUserDataLocking} is set and {@code keyEvictedCallback} is non-null.
     * -
     *
     * @param userId User Id to stop and lock the data.
     * @param allowDelayedLocking When set, do not lock user after stopping. Locking can happen
     *                            later when number of unlocked users reaches
     *                            {@code mMaxRunnngUsers}. Note that this is respected only when
     *                            {@code mDelayUserDataLocking} is set and {@keyEvictedCallback} is
     *                            null. Otherwise the user will be locked.
     * @param stopUserCallback Callback to notify that user has stopped.
     * @param keyEvictedCallback Callback to notify that user has been unlocked.
     */
    @GuardedBy("mLock")
    private void stopSingleUserLU(final int userId, boolean allowDelayedLocking,
            final IStopUserCallback stopUserCallback,
            KeyEvictedCallback keyEvictedCallback) {
        if (DEBUG_MU) Slog.i(TAG, "stopSingleUserLocked userId=" + userId);
        final UserState uss = mStartedUsers.get(userId);
        if (uss == null) {  // User is not started
            // If mDelayUserDataLocking is set and allowDelayedLocking is not set, we need to lock
            // the requested user as the client wants to stop and lock the user. On the other hand,
            // having keyEvictedCallback set will lead into locking user if mDelayUserDataLocking
            // is set as that means client wants to lock the user immediately.
            // If mDelayUserDataLocking is not set, the user was already locked when it was stopped
            // and no further action is necessary.
            if (mDelayUserDataLocking) {
                if (allowDelayedLocking && keyEvictedCallback != null) {
                    Slog.wtf(TAG, "allowDelayedLocking set with KeyEvictedCallback, ignore it"
                            + " and lock user:" + userId, new RuntimeException());
                    allowDelayedLocking = false;
                }
                if (!allowDelayedLocking) {
                    if (mLastActiveUsers.remove(Integer.valueOf(userId))) {
                        // should lock the user, user is already gone
                        final ArrayList<KeyEvictedCallback> keyEvictedCallbacks;
                        if (keyEvictedCallback != null) {
                            keyEvictedCallbacks = new ArrayList<>(1);
                            keyEvictedCallbacks.add(keyEvictedCallback);
                        } else {
                            keyEvictedCallbacks = null;
                        }
                        dispatchUserLocking(userId, keyEvictedCallbacks);
                    }
                }
            }
            // We do need to post the stopped callback even though user is already stopped.
            if (stopUserCallback != null) {
                mHandler.post(() -> {
                    try {
                        stopUserCallback.userStopped(userId);
                    } catch (RemoteException e) {
                    }
                });
            }
            return;
        }

        if (stopUserCallback != null) {
            uss.mStopCallbacks.add(stopUserCallback);
        }
        if (keyEvictedCallback != null) {
            uss.mKeyEvictedCallbacks.add(keyEvictedCallback);
        }

        if (uss.state != UserState.STATE_STOPPING
                && uss.state != UserState.STATE_SHUTDOWN) {
            uss.setState(UserState.STATE_STOPPING);
            mInjector.getUserManagerInternal().setUserState(userId, uss.state);
            updateStartedUserArrayLU();

            final boolean allowDelayyLockingCopied = allowDelayedLocking;
            // Post to handler to obtain amLock
            mHandler.post(() -> {
                // We are going to broadcast ACTION_USER_STOPPING and then
                // once that is done send a final ACTION_SHUTDOWN and then
                // stop the user.
                final Intent stoppingIntent = new Intent(Intent.ACTION_USER_STOPPING);
                stoppingIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
                stoppingIntent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
                stoppingIntent.putExtra(Intent.EXTRA_SHUTDOWN_USERSPACE_ONLY, true);
                // This is the result receiver for the initial stopping broadcast.
                final IIntentReceiver stoppingReceiver = new IIntentReceiver.Stub() {
                    @Override
                    public void performReceive(Intent intent, int resultCode, String data,
                            Bundle extras, boolean ordered, boolean sticky, int sendingUser) {
                        mHandler.post(() -> finishUserStopping(userId, uss,
                                allowDelayyLockingCopied));
                    }
                };

                // Clear broadcast queue for the user to avoid delivering stale broadcasts
                mInjector.clearBroadcastQueueForUser(userId);
                // Kick things off.
                mInjector.broadcastIntent(stoppingIntent,
                        null, stoppingReceiver, 0, null, null,
                        new String[]{INTERACT_ACROSS_USERS}, AppOpsManager.OP_NONE,
                        null, true, false, MY_PID, SYSTEM_UID, Binder.getCallingUid(),
                        Binder.getCallingPid(), UserHandle.USER_ALL);
            });
        }
    }

    void finishUserStopping(final int userId, final UserState uss,
            final boolean allowDelayedLocking) {
        EventLog.writeEvent(EventLogTags.UC_FINISH_USER_STOPPING, userId);
        // On to the next.
        final Intent shutdownIntent = new Intent(Intent.ACTION_SHUTDOWN);
        // This is the result receiver for the final shutdown broadcast.
        final IIntentReceiver shutdownReceiver = new IIntentReceiver.Stub() {
            @Override
            public void performReceive(Intent intent, int resultCode, String data,
                    Bundle extras, boolean ordered, boolean sticky, int sendingUser) {
                mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        finishUserStopped(uss, allowDelayedLocking);
                    }
                });
            }
        };

        synchronized (mLock) {
            if (uss.state != UserState.STATE_STOPPING) {
                // Whoops, we are being started back up.  Abort, abort!
                return;
            }
            uss.setState(UserState.STATE_SHUTDOWN);
        }
        mInjector.getUserManagerInternal().setUserState(userId, uss.state);

        mInjector.batteryStatsServiceNoteEvent(
                BatteryStats.HistoryItem.EVENT_USER_RUNNING_FINISH,
                Integer.toString(userId), userId);
        mInjector.getSystemServiceManager().stopUser(userId);

        mInjector.broadcastIntent(shutdownIntent,
                null, shutdownReceiver, 0, null, null, null,
                AppOpsManager.OP_NONE,
                null, true, false, MY_PID, SYSTEM_UID, Binder.getCallingUid(),
                Binder.getCallingPid(), userId);
    }

    void finishUserStopped(UserState uss, boolean allowDelayedLocking) {
        final int userId = uss.mHandle.getIdentifier();
        EventLog.writeEvent(EventLogTags.UC_FINISH_USER_STOPPED, userId);
        final boolean stopped;
        boolean lockUser = true;
        final ArrayList<IStopUserCallback> stopCallbacks;
        final ArrayList<KeyEvictedCallback> keyEvictedCallbacks;
        int userIdToLock = userId;
        synchronized (mLock) {
            stopCallbacks = new ArrayList<>(uss.mStopCallbacks);
            keyEvictedCallbacks = new ArrayList<>(uss.mKeyEvictedCallbacks);
            if (mStartedUsers.get(userId) != uss || uss.state != UserState.STATE_SHUTDOWN) {
                stopped = false;
            } else {
                stopped = true;
                // User can no longer run.
                mStartedUsers.remove(userId);
                mUserLru.remove(Integer.valueOf(userId));
                updateStartedUserArrayLU();
                if (allowDelayedLocking && !keyEvictedCallbacks.isEmpty()) {
                    Slog.wtf(TAG,
                            "Delayed locking enabled while KeyEvictedCallbacks not empty, userId:"
                                    + userId + " callbacks:" + keyEvictedCallbacks);
                    allowDelayedLocking = false;
                }
                userIdToLock = updateUserToLockLU(userId, allowDelayedLocking);
                if (userIdToLock == UserHandle.USER_NULL) {
                    lockUser = false;
                }
            }
        }
        if (stopped) {
            mInjector.getUserManagerInternal().removeUserState(userId);
            mInjector.activityManagerOnUserStopped(userId);
            // Clean up all state and processes associated with the user.
            // Kill all the processes for the user.
            forceStopUser(userId, "finish user");
        }

        for (final IStopUserCallback callback : stopCallbacks) {
            try {
                if (stopped) callback.userStopped(userId);
                else callback.userStopAborted(userId);
            } catch (RemoteException ignored) {
            }
        }

        if (stopped) {
            mInjector.systemServiceManagerCleanupUser(userId);
            mInjector.stackSupervisorRemoveUser(userId);
            // Remove the user if it is ephemeral.
            UserInfo userInfo = getUserInfo(userId);
            if (userInfo.isEphemeral() && !userInfo.preCreated) {
                mInjector.getUserManager().removeUserEvenWhenDisallowed(userId);
            }

            if (!lockUser) {
                return;
            }
            dispatchUserLocking(userIdToLock, keyEvictedCallbacks);
        }
    }

    private void dispatchUserLocking(@UserIdInt int userId,
            @Nullable List<KeyEvictedCallback> keyEvictedCallbacks) {
        // Evict the user's credential encryption key. Performed on FgThread to make it
        // serialized with call to UserManagerService.onBeforeUnlockUser in finishUserUnlocking
        // to prevent data corruption.
        FgThread.getHandler().post(() -> {
            synchronized (mLock) {
                if (mStartedUsers.get(userId) != null) {
                    Slog.w(TAG, "User was restarted, skipping key eviction");
                    return;
                }
            }
            try {
                mInjector.getStorageManager().lockUserKey(userId);
            } catch (RemoteException re) {
                throw re.rethrowAsRuntimeException();
            }
            if (keyEvictedCallbacks == null) {
                return;
            }
            for (int i = 0; i < keyEvictedCallbacks.size(); i++) {
                keyEvictedCallbacks.get(i).keyEvicted(userId);
            }
        });
    }

    /**
     * For mDelayUserDataLocking mode, storage once unlocked is kept unlocked.
     * Total number of unlocked user storage is limited by mMaxRunningUsers.
     * If there are more unlocked users, evict and lock the least recently stopped user and
     * lock that user's data. Regardless of the mode, ephemeral user is always locked
     * immediately.
     *
     * @return user id to lock. UserHandler.USER_NULL will be returned if no user should be locked.
     */
    @GuardedBy("mLock")
    private int updateUserToLockLU(@UserIdInt int userId, boolean allowDelayedLocking) {
        int userIdToLock = userId;
        if (mDelayUserDataLocking && allowDelayedLocking && !getUserInfo(userId).isEphemeral()
                && !hasUserRestriction(UserManager.DISALLOW_RUN_IN_BACKGROUND, userId)) {
            mLastActiveUsers.remove((Integer) userId); // arg should be object, not index
            mLastActiveUsers.add(0, userId);
            int totalUnlockedUsers = mStartedUsers.size() + mLastActiveUsers.size();
            if (totalUnlockedUsers > mMaxRunningUsers) { // should lock a user
                userIdToLock = mLastActiveUsers.get(mLastActiveUsers.size() - 1);
                mLastActiveUsers.remove(mLastActiveUsers.size() - 1);
                Slog.i(TAG, "finishUserStopped, stopping user:" + userId
                        + " lock user:" + userIdToLock);
            } else {
                Slog.i(TAG, "finishUserStopped, user:" + userId
                        + ",skip locking");
                // do not lock
                userIdToLock = UserHandle.USER_NULL;

            }
        }
        return userIdToLock;
    }

    /**
     * Determines the list of users that should be stopped together with the specified
     * {@code userId}. The returned list includes {@code userId}.
     */
    @GuardedBy("mLock")
    private @NonNull int[] getUsersToStopLU(@UserIdInt int userId) {
        int startedUsersSize = mStartedUsers.size();
        IntArray userIds = new IntArray();
        userIds.add(userId);
        int userGroupId = mUserProfileGroupIds.get(userId, UserInfo.NO_PROFILE_GROUP_ID);
        for (int i = 0; i < startedUsersSize; i++) {
            UserState uss = mStartedUsers.valueAt(i);
            int startedUserId = uss.mHandle.getIdentifier();
            // Skip unrelated users (profileGroupId mismatch)
            int startedUserGroupId = mUserProfileGroupIds.get(startedUserId,
                    UserInfo.NO_PROFILE_GROUP_ID);
            boolean sameGroup = (userGroupId != UserInfo.NO_PROFILE_GROUP_ID)
                    && (userGroupId == startedUserGroupId);
            // userId has already been added
            boolean sameUserId = startedUserId == userId;
            if (!sameGroup || sameUserId) {
                continue;
            }
            userIds.add(startedUserId);
        }
        return userIds.toArray();
    }

    private void forceStopUser(@UserIdInt int userId, String reason) {
        mInjector.activityManagerForceStopPackage(userId, reason);
        Intent intent = new Intent(Intent.ACTION_USER_STOPPED);
        intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY
                | Intent.FLAG_RECEIVER_FOREGROUND);
        intent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
        mInjector.broadcastIntent(intent,
                null, null, 0, null, null, null, AppOpsManager.OP_NONE,
                null, false, false, MY_PID, SYSTEM_UID, Binder.getCallingUid(),
                Binder.getCallingPid(), UserHandle.USER_ALL);
    }

    /**
     * Stops the guest or ephemeral user if it has gone to the background.
     */
    private void stopGuestOrEphemeralUserIfBackground(int oldUserId) {
        if (DEBUG_MU) Slog.i(TAG, "Stop guest or ephemeral user if background: " + oldUserId);
        synchronized(mLock) {
            UserState oldUss = mStartedUsers.get(oldUserId);
            if (oldUserId == UserHandle.USER_SYSTEM || oldUserId == mCurrentUserId || oldUss == null
                    || oldUss.state == UserState.STATE_STOPPING
                    || oldUss.state == UserState.STATE_SHUTDOWN) {
                return;
            }
        }

        UserInfo userInfo = getUserInfo(oldUserId);
        if (userInfo.isEphemeral()) {
            LocalServices.getService(UserManagerInternal.class).onEphemeralUserStop(oldUserId);
        }
        if (userInfo.isGuest() || userInfo.isEphemeral()) {
            // This is a user to be stopped.
            synchronized (mLock) {
                stopUsersLU(oldUserId, /* force= */ true, /* allowDelayedLocking= */ false,
                        null, null);
            }
        }
    }

    void scheduleStartProfiles() {
        // Parent user transition to RUNNING_UNLOCKING happens on FgThread, so it is busy, there is
        // a chance the profile will reach RUNNING_LOCKED while parent is still locked, so no
        // attempt will be made to unlock the profile. If we go via FgThread, this will be executed
        // after the parent had chance to unlock fully.
        FgThread.getHandler().post(() -> {
            if (!mHandler.hasMessages(START_PROFILES_MSG)) {
                mHandler.sendMessageDelayed(mHandler.obtainMessage(START_PROFILES_MSG),
                        DateUtils.SECOND_IN_MILLIS);
            }
        });
    }

    void startProfiles() {
        int currentUserId = getCurrentUserId();
        if (DEBUG_MU) Slog.i(TAG, "startProfilesLocked");
        List<UserInfo> profiles = mInjector.getUserManager().getProfiles(
                currentUserId, false /* enabledOnly */);
        List<UserInfo> profilesToStart = new ArrayList<>(profiles.size());
        for (UserInfo user : profiles) {
            if ((user.flags & UserInfo.FLAG_INITIALIZED) == UserInfo.FLAG_INITIALIZED
                    && user.id != currentUserId && !user.isQuietModeEnabled()) {
                profilesToStart.add(user);
            }
        }
        final int profilesToStartSize = profilesToStart.size();
        int i = 0;
        for (; i < profilesToStartSize && i < (getMaxRunningUsers() - 1); ++i) {
            startUser(profilesToStart.get(i).id, /* foreground= */ false);
        }
        if (i < profilesToStartSize) {
            Slog.w(TAG, "More profiles than MAX_RUNNING_USERS");
        }
    }

    boolean startUser(final @UserIdInt int userId, final boolean foreground) {
        return startUser(userId, foreground, null);
    }

    /**
     * Start user, if its not already running.
     * <p>The user will be brought to the foreground, if {@code foreground} parameter is set.
     * When starting the user, multiple intents will be broadcast in the following order:</p>
     * <ul>
     *     <li>{@link Intent#ACTION_USER_STARTED} - sent to registered receivers of the new user
     *     <li>{@link Intent#ACTION_USER_BACKGROUND} - sent to registered receivers of the outgoing
     *     user and all profiles of this user. Sent only if {@code foreground} parameter is
     *     {@code false}
     *     <li>{@link Intent#ACTION_USER_FOREGROUND} - sent to registered receivers of the new
     *     user and all profiles of this user. Sent only if {@code foreground} parameter is
     *     {@code true}
     *     <li>{@link Intent#ACTION_USER_SWITCHED} - sent to registered receivers of the new user.
     *     Sent only if {@code foreground} parameter is {@code true}
     *     <li>{@link Intent#ACTION_USER_STARTING} - ordered broadcast sent to registered receivers
     *     of the new fg user
     *     <li>{@link Intent#ACTION_LOCKED_BOOT_COMPLETED} - ordered broadcast sent to receivers of
     *     the new user
     *     <li>{@link Intent#ACTION_USER_UNLOCKED} - sent to registered receivers of the new user
     *     <li>{@link Intent#ACTION_PRE_BOOT_COMPLETED} - ordered broadcast sent to receivers of the
     *     new user. Sent only when the user is booting after a system update.
     *     <li>{@link Intent#ACTION_USER_INITIALIZE} - ordered broadcast sent to receivers of the
     *     new user. Sent only the first time a user is starting.
     *     <li>{@link Intent#ACTION_BOOT_COMPLETED} - ordered broadcast sent to receivers of the new
     *     user. Indicates that the user has finished booting.
     * </ul>
     *
     * @param userId ID of the user to start
     * @param foreground true if user should be brought to the foreground
     * @param unlockListener Listener to be informed when the user has started and unlocked.
     * @return true if the user has been successfully started
     */
    boolean startUser(
            final @UserIdInt int userId,
            final boolean foreground,
            @Nullable IProgressListener unlockListener) {

        checkCallingPermission(INTERACT_ACROSS_USERS_FULL, "startUser");

        TimingsTraceAndSlog t = new TimingsTraceAndSlog();

        t.traceBegin("startUser-" + userId + "-" + (foreground ? "fg" : "bg"));
        try {
            return startUserInternal(userId, foreground, unlockListener, t);
        } finally {
            t.traceEnd();
        }
    }

    private boolean startUserInternal(@UserIdInt int userId, boolean foreground,
            @Nullable IProgressListener unlockListener, @NonNull TimingsTraceAndSlog t) {
        EventLog.writeEvent(EventLogTags.UC_START_USER_INTERNAL, userId);

        final int callingUid = Binder.getCallingUid();
        final int callingPid = Binder.getCallingPid();
        final long ident = Binder.clearCallingIdentity();
        try {
            t.traceBegin("getStartedUserState");
            final int oldUserId = getCurrentUserId();
            if (oldUserId == userId) {
                final UserState state = getStartedUserState(userId);
                if (state == null) {
                    Slog.wtf(TAG, "Current user has no UserState");
                    // continue starting.
                } else {
                    if (userId == UserHandle.USER_SYSTEM && state.state == STATE_BOOTING) {
                        // system user start explicitly requested. should continue starting as it
                        // is not in running state.
                    } else {
                        if (state.state == STATE_RUNNING_UNLOCKED) {
                            // We'll skip all later code, so we must tell listener it's already
                            // unlocked.
                            notifyFinished(userId, unlockListener);
                        }
                        t.traceEnd(); //getStartedUserState
                        return true;
                    }
                }
            }
            t.traceEnd(); //getStartedUserState

            if (foreground) {
                t.traceBegin("clearAllLockedTasks");
                mInjector.clearAllLockedTasks("startUser");
                t.traceEnd();
            }

            t.traceBegin("getUserInfo");
            final UserInfo userInfo = getUserInfo(userId);
            t.traceEnd();

            if (userInfo == null) {
                Slog.w(TAG, "No user info for user #" + userId);
                return false;
            }
            if (foreground && userInfo.isManagedProfile()) {
                Slog.w(TAG, "Cannot switch to User #" + userId + ": not a full user");
                return false;
            }

            if (foreground && userInfo.preCreated) {
                Slog.w(TAG, "Cannot start pre-created user #" + userId + " as foreground");
                return false;
            }

            if (foreground && isUserSwitchUiEnabled()) {
                t.traceBegin("startFreezingScreen");
                mInjector.getWindowManager().startFreezingScreen(
                        R.anim.screen_user_exit, R.anim.screen_user_enter);
                t.traceEnd();
            }

            boolean needStart = false;
            boolean updateUmState = false;
            UserState uss;

            // If the user we are switching to is not currently started, then
            // we need to start it now.
            t.traceBegin("updateStartedUserArrayStarting");
            synchronized (mLock) {
                uss = mStartedUsers.get(userId);
                if (uss == null) {
                    uss = new UserState(UserHandle.of(userId));
                    uss.mUnlockProgress.addListener(new UserProgressListener());
                    mStartedUsers.put(userId, uss);
                    updateStartedUserArrayLU();
                    needStart = true;
                    updateUmState = true;
                } else if (uss.state == UserState.STATE_SHUTDOWN && !isCallingOnHandlerThread()) {
                    Slog.i(TAG, "User #" + userId
                            + " is shutting down - will start after full stop");
                    mHandler.post(() -> startUser(userId, foreground, unlockListener));
                    t.traceEnd(); // updateStartedUserArrayStarting
                    return true;
                }
                final Integer userIdInt = userId;
                mUserLru.remove(userIdInt);
                mUserLru.add(userIdInt);
            }
            if (unlockListener != null) {
                uss.mUnlockProgress.addListener(unlockListener);
            }
            t.traceEnd(); // updateStartedUserArrayStarting

            if (updateUmState) {
                t.traceBegin("setUserState");
                mInjector.getUserManagerInternal().setUserState(userId, uss.state);
                t.traceEnd();
            }
            t.traceBegin("updateConfigurationAndProfileIds");
            if (foreground) {
                // Make sure the old user is no longer considering the display to be on.
                mInjector.reportGlobalUsageEventLocked(UsageEvents.Event.SCREEN_NON_INTERACTIVE);
                boolean userSwitchUiEnabled;
                synchronized (mLock) {
                    mCurrentUserId = userId;
                    mTargetUserId = UserHandle.USER_NULL; // reset, mCurrentUserId has caught up
                    userSwitchUiEnabled = mUserSwitchUiEnabled;
                }
                mInjector.updateUserConfiguration();
                updateCurrentProfileIds();
                mInjector.getWindowManager().setCurrentUser(userId, getCurrentProfileIds());
                mInjector.reportCurWakefulnessUsageEvent();
                // Once the internal notion of the active user has switched, we lock the device
                // with the option to show the user switcher on the keyguard.
                if (userSwitchUiEnabled) {
                    mInjector.getWindowManager().setSwitchingUser(true);
                    mInjector.getWindowManager().lockNow(null);
                }
            } else {
                final Integer currentUserIdInt = mCurrentUserId;
                updateCurrentProfileIds();
                mInjector.getWindowManager().setCurrentProfileIds(getCurrentProfileIds());
                synchronized (mLock) {
                    mUserLru.remove(currentUserIdInt);
                    mUserLru.add(currentUserIdInt);
                }
            }
            t.traceEnd();

            // Make sure user is in the started state.  If it is currently
            // stopping, we need to knock that off.
            if (uss.state == UserState.STATE_STOPPING) {
                t.traceBegin("updateStateStopping");
                // If we are stopping, we haven't sent ACTION_SHUTDOWN,
                // so we can just fairly silently bring the user back from
                // the almost-dead.
                uss.setState(uss.lastState);
                mInjector.getUserManagerInternal().setUserState(userId, uss.state);
                synchronized (mLock) {
                    updateStartedUserArrayLU();
                }
                needStart = true;
                t.traceEnd();
            } else if (uss.state == UserState.STATE_SHUTDOWN) {
                t.traceBegin("updateStateShutdown");
                // This means ACTION_SHUTDOWN has been sent, so we will
                // need to treat this as a new boot of the user.
                uss.setState(UserState.STATE_BOOTING);
                mInjector.getUserManagerInternal().setUserState(userId, uss.state);
                synchronized (mLock) {
                    updateStartedUserArrayLU();
                }
                needStart = true;
                t.traceEnd();
            }

            if (uss.state == UserState.STATE_BOOTING) {
                t.traceBegin("updateStateBooting");
                // Give user manager a chance to propagate user restrictions
                // to other services and prepare app storage
                mInjector.getUserManager().onBeforeStartUser(userId);

                // Booting up a new user, need to tell system services about it.
                // Note that this is on the same handler as scheduling of broadcasts,
                // which is important because it needs to go first.
                mHandler.sendMessage(mHandler.obtainMessage(USER_START_MSG, userId, 0));
                t.traceEnd();
            }

            t.traceBegin("sendMessages");
            if (foreground) {
                mHandler.sendMessage(mHandler.obtainMessage(USER_CURRENT_MSG, userId, oldUserId));
                mHandler.removeMessages(REPORT_USER_SWITCH_MSG);
                mHandler.removeMessages(USER_SWITCH_TIMEOUT_MSG);
                mHandler.sendMessage(mHandler.obtainMessage(REPORT_USER_SWITCH_MSG,
                        oldUserId, userId, uss));
                mHandler.sendMessageDelayed(mHandler.obtainMessage(USER_SWITCH_TIMEOUT_MSG,
                        oldUserId, userId, uss), USER_SWITCH_TIMEOUT_MS);
            }

            if (userInfo.preCreated) {
                needStart = false;
            }

            if (needStart) {
                // Send USER_STARTED broadcast
                Intent intent = new Intent(Intent.ACTION_USER_STARTED);
                intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY
                        | Intent.FLAG_RECEIVER_FOREGROUND);
                intent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
                mInjector.broadcastIntent(intent,
                        null, null, 0, null, null, null, AppOpsManager.OP_NONE,
                        null, false, false, MY_PID, SYSTEM_UID, callingUid, callingPid, userId);
            }
            t.traceEnd();

            if (foreground) {
                t.traceBegin("moveUserToForeground");
                moveUserToForeground(uss, oldUserId, userId);
                t.traceEnd();
            } else {
                t.traceBegin("finishUserBoot");
                finishUserBoot(uss);
                t.traceEnd();
            }

            if (needStart) {
                t.traceBegin("sendRestartBroadcast");
                Intent intent = new Intent(Intent.ACTION_USER_STARTING);
                intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
                intent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
                mInjector.broadcastIntent(intent,
                        null, new IIntentReceiver.Stub() {
                            @Override
                            public void performReceive(Intent intent, int resultCode,
                                    String data, Bundle extras, boolean ordered,
                                    boolean sticky,
                                    int sendingUser) throws RemoteException {
                            }
                        }, 0, null, null,
                        new String[]{INTERACT_ACROSS_USERS}, AppOpsManager.OP_NONE,
                        null, true, false, MY_PID, SYSTEM_UID, callingUid, callingPid,
                        UserHandle.USER_ALL);
                t.traceEnd();
            }
        } finally {
            Binder.restoreCallingIdentity(ident);
        }

        return true;
    }

    private boolean isCallingOnHandlerThread() {
        return Looper.myLooper() == mHandler.getLooper();
    }

    /**
     * Start user, if its not already running, and bring it to foreground.
     */
    void startUserInForeground(final int targetUserId) {
        boolean success = startUser(targetUserId, /* foreground */ true);
        if (!success) {
            mInjector.getWindowManager().setSwitchingUser(false);
        }
    }

    boolean unlockUser(final @UserIdInt int userId, byte[] token, byte[] secret,
            IProgressListener listener) {
        checkCallingPermission(INTERACT_ACROSS_USERS_FULL, "unlockUser");
        EventLog.writeEvent(EventLogTags.UC_UNLOCK_USER, userId);
        final long binderToken = Binder.clearCallingIdentity();
        try {
            return unlockUserCleared(userId, token, secret, listener);
        } finally {
            Binder.restoreCallingIdentity(binderToken);
        }
    }

    /**
     * Attempt to unlock user without a credential token. This typically
     * succeeds when the device doesn't have credential-encrypted storage, or
     * when the credential-encrypted storage isn't tied to a user-provided
     * PIN or pattern.
     */
    private boolean maybeUnlockUser(final @UserIdInt int userId) {
        // Try unlocking storage using empty token
        return unlockUserCleared(userId, null, null, null);
    }

    private static void notifyFinished(@UserIdInt int userId, IProgressListener listener) {
        if (listener == null) return;
        try {
            listener.onFinished(userId, null);
        } catch (RemoteException ignored) {
        }
    }

    private boolean unlockUserCleared(final @UserIdInt int userId, byte[] token, byte[] secret,
            IProgressListener listener) {
        UserState uss;
        if (!StorageManager.isUserKeyUnlocked(userId)) {
            final UserInfo userInfo = getUserInfo(userId);
            final IStorageManager storageManager = mInjector.getStorageManager();
            try {
                // We always want to unlock user storage, even user is not started yet
                storageManager.unlockUserKey(userId, userInfo.serialNumber, token, secret);
            } catch (RemoteException | RuntimeException e) {
                Slog.w(TAG, "Failed to unlock: " + e.getMessage());
            }
        }
        synchronized (mLock) {
            // Register the given listener to watch for unlock progress
            uss = mStartedUsers.get(userId);
            if (uss != null) {
                uss.mUnlockProgress.addListener(listener);
                uss.tokenProvided = (token != null);
            }
        }
        // Bail if user isn't actually running
        if (uss == null) {
            notifyFinished(userId, listener);
            return false;
        }

        if (!finishUserUnlocking(uss)) {
            notifyFinished(userId, listener);
            return false;
        }

        // We just unlocked a user, so let's now attempt to unlock any
        // managed profiles under that user.

        // First, get list of userIds. Requires mLock, so we cannot make external calls, e.g. to UMS
        int[] userIds;
        synchronized (mLock) {
            userIds = new int[mStartedUsers.size()];
            for (int i = 0; i < userIds.length; i++) {
                userIds[i] = mStartedUsers.keyAt(i);
            }
        }
        for (int testUserId : userIds) {
            final UserInfo parent = mInjector.getUserManager().getProfileParent(testUserId);
            if (parent != null && parent.id == userId && testUserId != userId) {
                Slog.d(TAG, "User " + testUserId + " (parent " + parent.id
                        + "): attempting unlock because parent was just unlocked");
                maybeUnlockUser(testUserId);
            }
        }

        return true;
    }

    boolean switchUser(final int targetUserId) {
        enforceShellRestriction(UserManager.DISALLOW_DEBUGGING_FEATURES, targetUserId);
        EventLog.writeEvent(EventLogTags.UC_SWITCH_USER, targetUserId);
        int currentUserId = getCurrentUserId();
        UserInfo targetUserInfo = getUserInfo(targetUserId);
        if (targetUserId == currentUserId) {
            Slog.i(TAG, "user #" + targetUserId + " is already the current user");
            return true;
        }
        if (targetUserInfo == null) {
            Slog.w(TAG, "No user info for user #" + targetUserId);
            return false;
        }
        if (!targetUserInfo.supportsSwitchTo()) {
            Slog.w(TAG, "Cannot switch to User #" + targetUserId + ": not supported");
            return false;
        }
        if (targetUserInfo.isManagedProfile()) {
            Slog.w(TAG, "Cannot switch to User #" + targetUserId + ": not a full user");
            return false;
        }
        boolean userSwitchUiEnabled;
        synchronized (mLock) {
            if (!mInitialized) {
                Slog.e(TAG, "Cannot switch to User #" + targetUserId
                        + ": UserController not ready yet");
                return false;
            }
            mTargetUserId = targetUserId;
            userSwitchUiEnabled = mUserSwitchUiEnabled;
        }
        if (userSwitchUiEnabled) {
            UserInfo currentUserInfo = getUserInfo(currentUserId);
            Pair<UserInfo, UserInfo> userNames = new Pair<>(currentUserInfo, targetUserInfo);
            mUiHandler.removeMessages(START_USER_SWITCH_UI_MSG);
            mUiHandler.sendMessage(mHandler.obtainMessage(
                    START_USER_SWITCH_UI_MSG, userNames));
        } else {
            mHandler.removeMessages(START_USER_SWITCH_FG_MSG);
            mHandler.sendMessage(mHandler.obtainMessage(
                    START_USER_SWITCH_FG_MSG, targetUserId, 0));
        }
        return true;
    }

    private void showUserSwitchDialog(Pair<UserInfo, UserInfo> fromToUserPair) {
        // The dialog will show and then initiate the user switch by calling startUserInForeground
        mInjector.showUserSwitchingDialog(fromToUserPair.first, fromToUserPair.second,
                getSwitchingFromSystemUserMessage(), getSwitchingToSystemUserMessage());
    }

    private void dispatchForegroundProfileChanged(@UserIdInt int userId) {
        final int observerCount = mUserSwitchObservers.beginBroadcast();
        for (int i = 0; i < observerCount; i++) {
            try {
                mUserSwitchObservers.getBroadcastItem(i).onForegroundProfileSwitch(userId);
            } catch (RemoteException e) {
                // Ignore
            }
        }
        mUserSwitchObservers.finishBroadcast();
    }

    /** Called on handler thread */
    void dispatchUserSwitchComplete(@UserIdInt int userId) {
        mInjector.getWindowManager().setSwitchingUser(false);
        final int observerCount = mUserSwitchObservers.beginBroadcast();
        for (int i = 0; i < observerCount; i++) {
            try {
                mUserSwitchObservers.getBroadcastItem(i).onUserSwitchComplete(userId);
            } catch (RemoteException e) {
            }
        }
        mUserSwitchObservers.finishBroadcast();
    }

    private void dispatchLockedBootComplete(@UserIdInt int userId) {
        final int observerCount = mUserSwitchObservers.beginBroadcast();
        for (int i = 0; i < observerCount; i++) {
            try {
                mUserSwitchObservers.getBroadcastItem(i).onLockedBootComplete(userId);
            } catch (RemoteException e) {
                // Ignore
            }
        }
        mUserSwitchObservers.finishBroadcast();
    }

    private void stopBackgroundUsersIfEnforced(int oldUserId) {
        // Never stop system user
        if (oldUserId == UserHandle.USER_SYSTEM) {
            return;
        }
        // If running in background is disabled or mDelayUserDataLocking mode, stop the user.
        boolean disallowRunInBg = hasUserRestriction(UserManager.DISALLOW_RUN_IN_BACKGROUND,
                oldUserId) || isDelayUserDataLockingEnabled();
        if (!disallowRunInBg) {
            return;
        }
        synchronized (mLock) {
            if (DEBUG_MU) Slog.i(TAG, "stopBackgroundUsersIfEnforced stopping " + oldUserId
                    + " and related users");
            stopUsersLU(oldUserId, /* force= */ false, /* allowDelayedLocking= */ true,
                    null, null);
        }
    }

    private void timeoutUserSwitch(UserState uss, int oldUserId, int newUserId) {
        synchronized (mLock) {
            Slog.e(TAG, "User switch timeout: from " + oldUserId + " to " + newUserId);
            mTimeoutUserSwitchCallbacks = mCurWaitingUserSwitchCallbacks;
            mHandler.removeMessages(USER_SWITCH_CALLBACKS_TIMEOUT_MSG);
            sendContinueUserSwitchLU(uss, oldUserId, newUserId);
            // Report observers that never called back (USER_SWITCH_CALLBACKS_TIMEOUT)
            mHandler.sendMessageDelayed(mHandler.obtainMessage(USER_SWITCH_CALLBACKS_TIMEOUT_MSG,
                    oldUserId, newUserId), USER_SWITCH_CALLBACKS_TIMEOUT_MS);
        }
    }

    private void timeoutUserSwitchCallbacks(int oldUserId, int newUserId) {
        synchronized (mLock) {
            if (mTimeoutUserSwitchCallbacks != null && !mTimeoutUserSwitchCallbacks.isEmpty()) {
                Slog.wtf(TAG, "User switch timeout: from " + oldUserId + " to " + newUserId
                        + ". Observers that didn't respond: " + mTimeoutUserSwitchCallbacks);
                mTimeoutUserSwitchCallbacks = null;
            }
        }
    }

    void dispatchUserSwitch(final UserState uss, final int oldUserId, final int newUserId) {
        EventLog.writeEvent(EventLogTags.UC_DISPATCH_USER_SWITCH, oldUserId, newUserId);

        final int observerCount = mUserSwitchObservers.beginBroadcast();
        if (observerCount > 0) {
            final ArraySet<String> curWaitingUserSwitchCallbacks = new ArraySet<>();
            synchronized (mLock) {
                uss.switching = true;
                mCurWaitingUserSwitchCallbacks = curWaitingUserSwitchCallbacks;
            }
            final AtomicInteger waitingCallbacksCount = new AtomicInteger(observerCount);
            final long dispatchStartedTime = SystemClock.elapsedRealtime();
            for (int i = 0; i < observerCount; i++) {
                try {
                    // Prepend with unique prefix to guarantee that keys are unique
                    final String name = "#" + i + " " + mUserSwitchObservers.getBroadcastCookie(i);
                    synchronized (mLock) {
                        curWaitingUserSwitchCallbacks.add(name);
                    }
                    final IRemoteCallback callback = new IRemoteCallback.Stub() {
                        @Override
                        public void sendResult(Bundle data) throws RemoteException {
                            synchronized (mLock) {
                                long delay = SystemClock.elapsedRealtime() - dispatchStartedTime;
                                if (delay > USER_SWITCH_TIMEOUT_MS) {
                                    Slog.e(TAG, "User switch timeout: observer " + name
                                            + " sent result after " + delay + " ms");
                                } else if (delay > USER_SWITCH_WARNING_TIMEOUT_MS) {
                                    Slog.w(TAG, "User switch slowed down by observer " + name
                                            + ": result sent after " + delay + " ms");
                                }

                                curWaitingUserSwitchCallbacks.remove(name);
                                // Continue switching if all callbacks have been notified and
                                // user switching session is still valid
                                if (waitingCallbacksCount.decrementAndGet() == 0
                                        && (curWaitingUserSwitchCallbacks
                                        == mCurWaitingUserSwitchCallbacks)) {
                                    sendContinueUserSwitchLU(uss, oldUserId, newUserId);
                                }
                            }
                        }
                    };
                    mUserSwitchObservers.getBroadcastItem(i).onUserSwitching(newUserId, callback);
                } catch (RemoteException e) {
                }
            }
        } else {
            synchronized (mLock) {
                sendContinueUserSwitchLU(uss, oldUserId, newUserId);
            }
        }
        mUserSwitchObservers.finishBroadcast();
    }

    @GuardedBy("mLock")
    void sendContinueUserSwitchLU(UserState uss, int oldUserId, int newUserId) {
        mCurWaitingUserSwitchCallbacks = null;
        mHandler.removeMessages(USER_SWITCH_TIMEOUT_MSG);
        mHandler.sendMessage(mHandler.obtainMessage(CONTINUE_USER_SWITCH_MSG,
                oldUserId, newUserId, uss));
    }

    void continueUserSwitch(UserState uss, int oldUserId, int newUserId) {
        EventLog.writeEvent(EventLogTags.UC_CONTINUE_USER_SWITCH, oldUserId, newUserId);

        if (isUserSwitchUiEnabled()) {
            mInjector.getWindowManager().stopFreezingScreen();
        }
        uss.switching = false;
        mHandler.removeMessages(REPORT_USER_SWITCH_COMPLETE_MSG);
        mHandler.sendMessage(mHandler.obtainMessage(REPORT_USER_SWITCH_COMPLETE_MSG, newUserId, 0));
        stopGuestOrEphemeralUserIfBackground(oldUserId);
        stopBackgroundUsersIfEnforced(oldUserId);
    }

    private void moveUserToForeground(UserState uss, int oldUserId, int newUserId) {
        boolean homeInFront = mInjector.stackSupervisorSwitchUser(newUserId, uss);
        if (homeInFront) {
            mInjector.startHomeActivity(newUserId, "moveUserToForeground");
        } else {
            mInjector.stackSupervisorResumeFocusedStackTopActivity();
        }
        EventLogTags.writeAmSwitchUser(newUserId);
        sendUserSwitchBroadcasts(oldUserId, newUserId);
    }

    void sendUserSwitchBroadcasts(int oldUserId, int newUserId) {
        final int callingUid = Binder.getCallingUid();
        final int callingPid = Binder.getCallingPid();
        long ident = Binder.clearCallingIdentity();
        try {
            Intent intent;
            if (oldUserId >= 0) {
                // Send USER_BACKGROUND broadcast to all profiles of the outgoing user
                List<UserInfo> profiles = mInjector.getUserManager().getProfiles(oldUserId, false);
                int count = profiles.size();
                for (int i = 0; i < count; i++) {
                    int profileUserId = profiles.get(i).id;
                    intent = new Intent(Intent.ACTION_USER_BACKGROUND);
                    intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY
                            | Intent.FLAG_RECEIVER_FOREGROUND);
                    intent.putExtra(Intent.EXTRA_USER_HANDLE, profileUserId);
                    // Also, add the UserHandle for mainline modules which can't use the @hide
                    // EXTRA_USER_HANDLE.
                    intent.putExtra(Intent.EXTRA_USER, UserHandle.of(profileUserId));
                    mInjector.broadcastIntent(intent,
                            null, null, 0, null, null, null, AppOpsManager.OP_NONE,
                            null, false, false, MY_PID, SYSTEM_UID, callingUid, callingPid,
                            profileUserId);
                }
            }
            if (newUserId >= 0) {
                // Send USER_FOREGROUND broadcast to all profiles of the incoming user
                List<UserInfo> profiles = mInjector.getUserManager().getProfiles(newUserId, false);
                int count = profiles.size();
                for (int i = 0; i < count; i++) {
                    int profileUserId = profiles.get(i).id;
                    intent = new Intent(Intent.ACTION_USER_FOREGROUND);
                    intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY
                            | Intent.FLAG_RECEIVER_FOREGROUND);
                    intent.putExtra(Intent.EXTRA_USER_HANDLE, profileUserId);
                    // Also, add the UserHandle for mainline modules which can't use the @hide
                    // EXTRA_USER_HANDLE.
                    intent.putExtra(Intent.EXTRA_USER, UserHandle.of(profileUserId));
                    mInjector.broadcastIntent(intent,
                            null, null, 0, null, null, null, AppOpsManager.OP_NONE,
                            null, false, false, MY_PID, SYSTEM_UID, callingUid, callingPid,
                            profileUserId);
                }
                intent = new Intent(Intent.ACTION_USER_SWITCHED);
                intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY
                        | Intent.FLAG_RECEIVER_FOREGROUND);
                intent.putExtra(Intent.EXTRA_USER_HANDLE, newUserId);
                // Also, add the UserHandle for mainline modules which can't use the @hide
                // EXTRA_USER_HANDLE.
                intent.putExtra(Intent.EXTRA_USER, UserHandle.of(newUserId));
                mInjector.broadcastIntent(intent,
                        null, null, 0, null, null,
                        new String[] {android.Manifest.permission.MANAGE_USERS},
                        AppOpsManager.OP_NONE, null, false, false, MY_PID, SYSTEM_UID, callingUid,
                        callingPid, UserHandle.USER_ALL);
            }
        } finally {
            Binder.restoreCallingIdentity(ident);
        }
    }


    int handleIncomingUser(int callingPid, int callingUid, @UserIdInt int userId, boolean allowAll,
            int allowMode, String name, String callerPackage) {
        final int callingUserId = UserHandle.getUserId(callingUid);
        if (callingUserId == userId) {
            return userId;
        }

        // Note that we may be accessing mCurrentUserId outside of a lock...
        // shouldn't be a big deal, if this is being called outside
        // of a locked context there is intrinsically a race with
        // the value the caller will receive and someone else changing it.
        // We assume that USER_CURRENT_OR_SELF will use the current user; later
        // we will switch to the calling user if access to the current user fails.
        int targetUserId = unsafeConvertIncomingUser(userId);

        if (callingUid != 0 && callingUid != SYSTEM_UID) {
            final boolean allow;
            final boolean isSameProfileGroup = isSameProfileGroup(callingUserId, targetUserId);
            if (mInjector.isCallerRecents(callingUid)
                    && isSameProfileGroup(callingUserId, targetUserId)) {
                // If the caller is Recents and the caller has ownership of the profile group,
                // we then allow it to access its profiles.
                allow = true;
            } else if (mInjector.checkComponentPermission(INTERACT_ACROSS_USERS_FULL, callingPid,
                    callingUid, -1, true) == PackageManager.PERMISSION_GRANTED) {
                // If the caller has this permission, they always pass go.  And collect $200.
                allow = true;
            } else if (allowMode == ALLOW_FULL_ONLY) {
                // We require full access, sucks to be you.
                allow = false;
            } else if (canInteractWithAcrossProfilesPermission(
                    allowMode, isSameProfileGroup, callingPid, callingUid, callerPackage)) {
                allow = true;
            } else if (mInjector.checkComponentPermission(INTERACT_ACROSS_USERS, callingPid,
                    callingUid, -1, true) != PackageManager.PERMISSION_GRANTED) {
                // If the caller does not have either permission, they are always doomed.
                allow = false;
            } else if (allowMode == ALLOW_NON_FULL) {
                // We are blanket allowing non-full access, you lucky caller!
                allow = true;
            } else if (allowMode == ALLOW_NON_FULL_IN_PROFILE
                        || allowMode == ALLOW_ALL_PROFILE_PERMISSIONS_IN_PROFILE) {
                // We may or may not allow this depending on whether the two users are
                // in the same profile.
                allow = isSameProfileGroup;
            } else {
                throw new IllegalArgumentException("Unknown mode: " + allowMode);
            }
            if (!allow) {
                if (userId == UserHandle.USER_CURRENT_OR_SELF) {
                    // In this case, they would like to just execute as their
                    // owner user instead of failing.
                    targetUserId = callingUserId;
                } else {
                    StringBuilder builder = new StringBuilder(128);
                    builder.append("Permission Denial: ");
                    builder.append(name);
                    if (callerPackage != null) {
                        builder.append(" from ");
                        builder.append(callerPackage);
                    }
                    builder.append(" asks to run as user ");
                    builder.append(userId);
                    builder.append(" but is calling from uid ");
                    UserHandle.formatUid(builder, callingUid);
                    builder.append("; this requires ");
                    builder.append(INTERACT_ACROSS_USERS_FULL);
                    if (allowMode != ALLOW_FULL_ONLY) {
                        if (allowMode == ALLOW_NON_FULL || isSameProfileGroup) {
                            builder.append(" or ");
                            builder.append(INTERACT_ACROSS_USERS);
                        }
                        if (isSameProfileGroup
                                && allowMode == ALLOW_ALL_PROFILE_PERMISSIONS_IN_PROFILE) {
                            builder.append(" or ");
                            builder.append(INTERACT_ACROSS_PROFILES);
                        }
                    }
                    String msg = builder.toString();
                    Slog.w(TAG, msg);
                    throw new SecurityException(msg);
                }
            }
        }
        if (!allowAll) {
            ensureNotSpecialUser(targetUserId);
        }
        // Check shell permission
        if (callingUid == Process.SHELL_UID && targetUserId >= UserHandle.USER_SYSTEM) {
            if (hasUserRestriction(UserManager.DISALLOW_DEBUGGING_FEATURES, targetUserId)) {
                throw new SecurityException("Shell does not have permission to access user "
                        + targetUserId + "\n " + Debug.getCallers(3));
            }
        }
        return targetUserId;
    }

    private boolean canInteractWithAcrossProfilesPermission(
            int allowMode, boolean isSameProfileGroup, int callingPid, int callingUid,
            String callingPackage) {
        if (allowMode != ALLOW_ALL_PROFILE_PERMISSIONS_IN_PROFILE) {
            return false;
        }
        if (!isSameProfileGroup) {
            return false;
        }
        return  PermissionChecker.PERMISSION_GRANTED
                == PermissionChecker.checkPermissionForPreflight(
                        mInjector.getContext(),
                        INTERACT_ACROSS_PROFILES,
                        callingPid,
                        callingUid,
                        callingPackage);
    }

    int unsafeConvertIncomingUser(@UserIdInt int userId) {
        return (userId == UserHandle.USER_CURRENT || userId == UserHandle.USER_CURRENT_OR_SELF)
                ? getCurrentUserId(): userId;
    }

    void ensureNotSpecialUser(@UserIdInt int userId) {
        if (userId >= 0) {
            return;
        }
        throw new IllegalArgumentException("Call does not support special user #" + userId);
    }

    void registerUserSwitchObserver(IUserSwitchObserver observer, String name) {
        Objects.requireNonNull(name, "Observer name cannot be null");
        checkCallingPermission(INTERACT_ACROSS_USERS_FULL, "registerUserSwitchObserver");
        mUserSwitchObservers.register(observer, name);
    }

    void sendForegroundProfileChanged(@UserIdInt int userId) {
        mHandler.removeMessages(FOREGROUND_PROFILE_CHANGED_MSG);
        mHandler.obtainMessage(FOREGROUND_PROFILE_CHANGED_MSG, userId, 0).sendToTarget();
    }

    void unregisterUserSwitchObserver(IUserSwitchObserver observer) {
        mUserSwitchObservers.unregister(observer);
    }

    UserState getStartedUserState(@UserIdInt int userId) {
        synchronized (mLock) {
            return mStartedUsers.get(userId);
        }
    }

    boolean hasStartedUserState(@UserIdInt int userId) {
        synchronized (mLock) {
            return mStartedUsers.get(userId) != null;
        }
    }

    @GuardedBy("mLock")
    private void updateStartedUserArrayLU() {
        int num = 0;
        for (int i = 0; i < mStartedUsers.size(); i++) {
            UserState uss = mStartedUsers.valueAt(i);
            // This list does not include stopping users.
            if (uss.state != UserState.STATE_STOPPING
                    && uss.state != UserState.STATE_SHUTDOWN) {
                num++;
            }
        }
        mStartedUserArray = new int[num];
        num = 0;
        for (int i = 0; i < mStartedUsers.size(); i++) {
            UserState uss = mStartedUsers.valueAt(i);
            if (uss.state != UserState.STATE_STOPPING
                    && uss.state != UserState.STATE_SHUTDOWN) {
                mStartedUserArray[num++] = mStartedUsers.keyAt(i);
            }
        }
    }

    void sendBootCompleted(IIntentReceiver resultTo) {
        final boolean systemUserFinishedBooting;

        // Get a copy of mStartedUsers to use outside of lock
        SparseArray<UserState> startedUsers;
        synchronized (mLock) {
            systemUserFinishedBooting = mCurrentUserId != UserHandle.USER_SYSTEM;
            startedUsers = mStartedUsers.clone();
        }
        for (int i = 0; i < startedUsers.size(); i++) {
            UserState uss = startedUsers.valueAt(i);
            if (systemUserFinishedBooting && uss.mHandle.isSystem()) {
                // On Automotive, at this point the system user has already been started and
                // unlocked, and some of the tasks we do here have already been done. So skip those
                // in that case.
                // TODO(b/132262830): this workdound shouldn't be necessary once we move the
                // headless-user start logic to UserManager-land
                Slog.d(TAG, "sendBootCompleted(): skipping on non-current system user");
                continue;
            }
            finishUserBoot(uss, resultTo);
        }
    }

    void onSystemReady() {
        updateCurrentProfileIds();
        mInjector.reportCurWakefulnessUsageEvent();
    }

    /**
     * Refreshes the list of users related to the current user when either a
     * user switch happens or when a new related user is started in the
     * background.
     */
    private void updateCurrentProfileIds() {
        final List<UserInfo> profiles = mInjector.getUserManager().getProfiles(getCurrentUserId(),
                false /* enabledOnly */);
        int[] currentProfileIds = new int[profiles.size()]; // profiles will not be null
        for (int i = 0; i < currentProfileIds.length; i++) {
            currentProfileIds[i] = profiles.get(i).id;
        }
        final List<UserInfo> users = mInjector.getUserManager().getUsers(false);
        synchronized (mLock) {
            mCurrentProfileIds = currentProfileIds;

            mUserProfileGroupIds.clear();
            for (int i = 0; i < users.size(); i++) {
                UserInfo user = users.get(i);
                if (user.profileGroupId != UserInfo.NO_PROFILE_GROUP_ID) {
                    mUserProfileGroupIds.put(user.id, user.profileGroupId);
                }
            }
        }
    }

    int[] getStartedUserArray() {
        synchronized (mLock) {
            return mStartedUserArray;
        }
    }

    boolean isUserRunning(@UserIdInt int userId, int flags) {
        UserState state = getStartedUserState(userId);
        if (state == null) {
            return false;
        }
        if ((flags & ActivityManager.FLAG_OR_STOPPED) != 0) {
            return true;
        }
        if ((flags & ActivityManager.FLAG_AND_LOCKED) != 0) {
            switch (state.state) {
                case UserState.STATE_BOOTING:
                case UserState.STATE_RUNNING_LOCKED:
                    return true;
                default:
                    return false;
            }
        }
        if ((flags & ActivityManager.FLAG_AND_UNLOCKING_OR_UNLOCKED) != 0) {
            switch (state.state) {
                case UserState.STATE_RUNNING_UNLOCKING:
                case UserState.STATE_RUNNING_UNLOCKED:
                    return true;
                // In the stopping/shutdown state return unlock state of the user key
                case UserState.STATE_STOPPING:
                case UserState.STATE_SHUTDOWN:
                    return StorageManager.isUserKeyUnlocked(userId);
                default:
                    return false;
            }
        }
        if ((flags & ActivityManager.FLAG_AND_UNLOCKED) != 0) {
            switch (state.state) {
                case UserState.STATE_RUNNING_UNLOCKED:
                    return true;
                // In the stopping/shutdown state return unlock state of the user key
                case UserState.STATE_STOPPING:
                case UserState.STATE_SHUTDOWN:
                    return StorageManager.isUserKeyUnlocked(userId);
                default:
                    return false;
            }
        }

        return state.state != UserState.STATE_STOPPING && state.state != UserState.STATE_SHUTDOWN;
    }

    /**
     * Check if system user is already started. Unlike other user, system user is in STATE_BOOTING
     * even if it is not explicitly started. So isUserRunning cannot give the right state
     * to check if system user is started or not.
     * @return true if system user is started.
     */
    boolean isSystemUserStarted() {
        synchronized (mLock) {
            UserState uss = mStartedUsers.get(UserHandle.USER_SYSTEM);
            if (uss == null) {
                return false;
            }
            return uss.state == UserState.STATE_RUNNING_LOCKED
                || uss.state == UserState.STATE_RUNNING_UNLOCKING
                || uss.state == UserState.STATE_RUNNING_UNLOCKED;
        }
    }

    UserInfo getCurrentUser() {
        if ((mInjector.checkCallingPermission(INTERACT_ACROSS_USERS)
                != PackageManager.PERMISSION_GRANTED) && (
                mInjector.checkCallingPermission(INTERACT_ACROSS_USERS_FULL)
                        != PackageManager.PERMISSION_GRANTED)) {
            String msg = "Permission Denial: getCurrentUser() from pid="
                    + Binder.getCallingPid()
                    + ", uid=" + Binder.getCallingUid()
                    + " requires " + INTERACT_ACROSS_USERS;
            Slog.w(TAG, msg);
            throw new SecurityException(msg);
        }

        // Optimization - if there is no pending user switch, return current id
        // (no need to acquire lock because mTargetUserId and mCurrentUserId are volatile)
        if (mTargetUserId == UserHandle.USER_NULL) {
            return getUserInfo(mCurrentUserId);
        }
        synchronized (mLock) {
            return getCurrentUserLU();
        }
    }

    @GuardedBy("mLock")
    UserInfo getCurrentUserLU() {
        int userId = mTargetUserId != UserHandle.USER_NULL ? mTargetUserId : mCurrentUserId;
        return getUserInfo(userId);
    }

    int getCurrentOrTargetUserId() {
        synchronized (mLock) {
            return getCurrentOrTargetUserIdLU();
        }
    }

    @GuardedBy("mLock")
    int getCurrentOrTargetUserIdLU() {
        return mTargetUserId != UserHandle.USER_NULL ? mTargetUserId : mCurrentUserId;
    }


    @GuardedBy("mLock")
    int getCurrentUserIdLU() {
        return mCurrentUserId;
    }

    int getCurrentUserId() {
        synchronized (mLock) {
            return mCurrentUserId;
        }
    }

    @GuardedBy("mLock")
    private boolean isCurrentUserLU(@UserIdInt int userId) {
        return userId == getCurrentOrTargetUserIdLU();
    }

    int[] getUsers() {
        UserManagerService ums = mInjector.getUserManager();
        return ums != null ? ums.getUserIds() : new int[] { 0 };
    }

    private UserInfo getUserInfo(@UserIdInt int userId) {
        return mInjector.getUserManager().getUserInfo(userId);
    }

    int[] getUserIds() {
        return mInjector.getUserManager().getUserIds();
    }

    /**
     * If {@code userId} is {@link UserHandle#USER_ALL}, then return an array with all running user
     * IDs. Otherwise return an array whose only element is the given user id.
     *
     * It doesn't handle other special user IDs such as {@link UserHandle#USER_CURRENT}.
     */
    int[] expandUserId(@UserIdInt int userId) {
        if (userId != UserHandle.USER_ALL) {
            return new int[] {userId};
        } else {
            return getUsers();
        }
    }

    boolean exists(@UserIdInt int userId) {
        return mInjector.getUserManager().exists(userId);
    }

    private void checkCallingPermission(String permission, String methodName) {
        if (mInjector.checkCallingPermission(permission)
                != PackageManager.PERMISSION_GRANTED) {
            String msg = "Permission denial: " + methodName
                    + "() from pid=" + Binder.getCallingPid()
                    + ", uid=" + Binder.getCallingUid()
                    + " requires " + permission;
            Slog.w(TAG, msg);
            throw new SecurityException(msg);
        }
    }

    private void enforceShellRestriction(String restriction, @UserIdInt int userId) {
        if (Binder.getCallingUid() == SHELL_UID) {
            if (userId < 0 || hasUserRestriction(restriction, userId)) {
                throw new SecurityException("Shell does not have permission to access user "
                        + userId);
            }
        }
    }

    boolean hasUserRestriction(String restriction, @UserIdInt int userId) {
        return mInjector.getUserManager().hasUserRestriction(restriction, userId);
    }

    boolean isSameProfileGroup(int callingUserId, int targetUserId) {
        if (callingUserId == targetUserId) {
            return true;
        }
        synchronized (mLock) {
            int callingProfile = mUserProfileGroupIds.get(callingUserId,
                    UserInfo.NO_PROFILE_GROUP_ID);
            int targetProfile = mUserProfileGroupIds.get(targetUserId,
                    UserInfo.NO_PROFILE_GROUP_ID);
            return callingProfile != UserInfo.NO_PROFILE_GROUP_ID
                    && callingProfile == targetProfile;
        }
    }

    boolean isUserOrItsParentRunning(@UserIdInt int userId) {
        synchronized (mLock) {
            if (isUserRunning(userId, 0)) {
                return true;
            }
            final int parentUserId = mUserProfileGroupIds.get(userId, UserInfo.NO_PROFILE_GROUP_ID);
            if (parentUserId == UserInfo.NO_PROFILE_GROUP_ID) {
                return false;
            }
            return isUserRunning(parentUserId, 0);
        }
    }

    boolean isCurrentProfile(@UserIdInt int userId) {
        synchronized (mLock) {
            return ArrayUtils.contains(mCurrentProfileIds, userId);
        }
    }

    int[] getCurrentProfileIds() {
        synchronized (mLock) {
            return mCurrentProfileIds;
        }
    }

    void onUserRemoved(@UserIdInt int userId) {
        synchronized (mLock) {
            int size = mUserProfileGroupIds.size();
            for (int i = size - 1; i >= 0; i--) {
                if (mUserProfileGroupIds.keyAt(i) == userId
                        || mUserProfileGroupIds.valueAt(i) == userId) {
                    mUserProfileGroupIds.removeAt(i);

                }
            }
            mCurrentProfileIds = ArrayUtils.removeInt(mCurrentProfileIds, userId);
        }
    }

    /**
     * Returns whether the given user requires credential entry at this time. This is used to
     * intercept activity launches for locked work apps due to work challenge being triggered
     * or when the profile user is yet to be unlocked.
     */
    protected boolean shouldConfirmCredentials(@UserIdInt int userId) {
        if (getStartedUserState(userId) == null) {
            return false;
        }
        if (!getUserInfo(userId).isManagedProfile()) {
            return false;
        }
        if (mLockPatternUtils.isSeparateProfileChallengeEnabled(userId)) {
            final KeyguardManager km = mInjector.getKeyguardManager();
            return km.isDeviceLocked(userId) && km.isDeviceSecure(userId);
        } else {
            // For unified challenge, need to confirm credential if user is RUNNING_LOCKED.
            return isUserRunning(userId, ActivityManager.FLAG_AND_LOCKED);
        }
    }

    boolean isLockScreenDisabled(@UserIdInt int userId) {
        return mLockPatternUtils.isLockScreenDisabled(userId);
    }

    void setSwitchingFromSystemUserMessage(String switchingFromSystemUserMessage) {
        synchronized (mLock) {
            mSwitchingFromSystemUserMessage = switchingFromSystemUserMessage;
        }
    }

    void setSwitchingToSystemUserMessage(String switchingToSystemUserMessage) {
        synchronized (mLock) {
            mSwitchingToSystemUserMessage = switchingToSystemUserMessage;
        }
    }

    private String getSwitchingFromSystemUserMessage() {
        synchronized (mLock) {
            return mSwitchingFromSystemUserMessage;
        }
    }

    private String getSwitchingToSystemUserMessage() {
        synchronized (mLock) {
            return mSwitchingToSystemUserMessage;
        }
    }

    void dumpDebug(ProtoOutputStream proto, long fieldId) {
        synchronized (mLock) {
            long token = proto.start(fieldId);
            for (int i = 0; i < mStartedUsers.size(); i++) {
                UserState uss = mStartedUsers.valueAt(i);
                final long uToken = proto.start(UserControllerProto.STARTED_USERS);
                proto.write(UserControllerProto.User.ID, uss.mHandle.getIdentifier());
                uss.dumpDebug(proto, UserControllerProto.User.STATE);
                proto.end(uToken);
            }
            for (int i = 0; i < mStartedUserArray.length; i++) {
                proto.write(UserControllerProto.STARTED_USER_ARRAY, mStartedUserArray[i]);
            }
            for (int i = 0; i < mUserLru.size(); i++) {
                proto.write(UserControllerProto.USER_LRU, mUserLru.get(i));
            }
            if (mUserProfileGroupIds.size() > 0) {
                for (int i = 0; i < mUserProfileGroupIds.size(); i++) {
                    final long uToken = proto.start(UserControllerProto.USER_PROFILE_GROUP_IDS);
                    proto.write(UserControllerProto.UserProfile.USER,
                            mUserProfileGroupIds.keyAt(i));
                    proto.write(UserControllerProto.UserProfile.PROFILE,
                            mUserProfileGroupIds.valueAt(i));
                    proto.end(uToken);
                }
            }
            proto.end(token);
        }
    }

    void dump(PrintWriter pw) {
        synchronized (mLock) {
            pw.println("  mStartedUsers:");
            for (int i = 0; i < mStartedUsers.size(); i++) {
                UserState uss = mStartedUsers.valueAt(i);
                pw.print("    User #");
                pw.print(uss.mHandle.getIdentifier());
                pw.print(": ");
                uss.dump("", pw);
            }
            pw.print("  mStartedUserArray: [");
            for (int i = 0; i < mStartedUserArray.length; i++) {
                if (i > 0)
                    pw.print(", ");
                pw.print(mStartedUserArray[i]);
            }
            pw.println("]");
            pw.print("  mUserLru: [");
            for (int i = 0; i < mUserLru.size(); i++) {
                if (i > 0)
                    pw.print(", ");
                pw.print(mUserLru.get(i));
            }
            pw.println("]");
            if (mUserProfileGroupIds.size() > 0) {
                pw.println("  mUserProfileGroupIds:");
                for (int i=0; i< mUserProfileGroupIds.size(); i++) {
                    pw.print("    User #");
                    pw.print(mUserProfileGroupIds.keyAt(i));
                    pw.print(" -> profile #");
                    pw.println(mUserProfileGroupIds.valueAt(i));
                }
            }
            pw.println("  mCurrentUserId:" + mCurrentUserId);
            pw.println("  mTargetUserId:" + mTargetUserId);
            pw.println("  mLastActiveUsers:" + mLastActiveUsers);
            pw.println("  mDelayUserDataLocking:" + mDelayUserDataLocking);
            pw.println("  mMaxRunningUsers:" + mMaxRunningUsers);
            pw.println("  mUserSwitchUiEnabled:" + mUserSwitchUiEnabled);
            pw.println("  mInitialized:" + mInitialized);
        }
    }

    @Override
    public boolean handleMessage(Message msg) {
        switch (msg.what) {
            case START_USER_SWITCH_FG_MSG:
                logUserJourneyInfo(getUserInfo(getCurrentUserId()), getUserInfo(msg.arg1),
                        USER_JOURNEY_USER_SWITCH_FG);
                logUserLifecycleEvent(msg.arg1, USER_LIFECYCLE_EVENT_SWITCH_USER,
                        USER_LIFECYCLE_EVENT_STATE_BEGIN);
                startUserInForeground(msg.arg1);
                break;
            case REPORT_USER_SWITCH_MSG:
                dispatchUserSwitch((UserState) msg.obj, msg.arg1, msg.arg2);
                break;
            case CONTINUE_USER_SWITCH_MSG:
                continueUserSwitch((UserState) msg.obj, msg.arg1, msg.arg2);
                break;
            case USER_SWITCH_TIMEOUT_MSG:
                timeoutUserSwitch((UserState) msg.obj, msg.arg1, msg.arg2);
                break;
            case USER_SWITCH_CALLBACKS_TIMEOUT_MSG:
                timeoutUserSwitchCallbacks(msg.arg1, msg.arg2);
                break;
            case START_PROFILES_MSG:
                startProfiles();
                break;
            case USER_START_MSG:
                mInjector.batteryStatsServiceNoteEvent(
                        BatteryStats.HistoryItem.EVENT_USER_RUNNING_START,
                        Integer.toString(msg.arg1), msg.arg1);
                logUserJourneyInfo(null, getUserInfo(msg.arg1), USER_JOURNEY_USER_START);
                logUserLifecycleEvent(msg.arg1, USER_LIFECYCLE_EVENT_START_USER,
                        USER_LIFECYCLE_EVENT_STATE_BEGIN);

                mInjector.getSystemServiceManager().startUser(TimingsTraceAndSlog.newAsyncLog(),
                        msg.arg1);

                logUserLifecycleEvent(msg.arg1, USER_LIFECYCLE_EVENT_START_USER,
                        USER_LIFECYCLE_EVENT_STATE_FINISH);
                clearSessionId(msg.arg1, USER_JOURNEY_USER_START);
                break;
            case USER_UNLOCK_MSG:
                final int userId = msg.arg1;
                mInjector.getSystemServiceManager().unlockUser(userId);
                // Loads recents on a worker thread that allows disk I/O
                FgThread.getHandler().post(() -> {
                    mInjector.loadUserRecents(userId);
                });
                logUserLifecycleEvent(msg.arg1, USER_LIFECYCLE_EVENT_UNLOCKING_USER,
                        USER_LIFECYCLE_EVENT_STATE_FINISH);
                logUserLifecycleEvent(msg.arg1, USER_LIFECYCLE_EVENT_UNLOCKED_USER,
                        USER_LIFECYCLE_EVENT_STATE_BEGIN);
                finishUserUnlocked((UserState) msg.obj);
                break;
            case USER_UNLOCKED_MSG:
                mInjector.getSystemServiceManager().onUserUnlocked(msg.arg1);
                logUserLifecycleEvent(msg.arg1, USER_LIFECYCLE_EVENT_UNLOCKED_USER,
                        USER_LIFECYCLE_EVENT_STATE_FINISH);
                clearSessionId(msg.arg1);
                break;
            case USER_CURRENT_MSG:
                mInjector.batteryStatsServiceNoteEvent(
                        BatteryStats.HistoryItem.EVENT_USER_FOREGROUND_FINISH,
                        Integer.toString(msg.arg2), msg.arg2);
                mInjector.batteryStatsServiceNoteEvent(
                        BatteryStats.HistoryItem.EVENT_USER_FOREGROUND_START,
                        Integer.toString(msg.arg1), msg.arg1);

                mInjector.getSystemServiceManager().switchUser(msg.arg2, msg.arg1);
                break;
            case FOREGROUND_PROFILE_CHANGED_MSG:
                dispatchForegroundProfileChanged(msg.arg1);
                break;
            case REPORT_USER_SWITCH_COMPLETE_MSG:
                dispatchUserSwitchComplete(msg.arg1);

                logUserLifecycleEvent(msg.arg1, USER_LIFECYCLE_EVENT_SWITCH_USER,
                        USER_LIFECYCLE_EVENT_STATE_FINISH);
                break;
            case REPORT_LOCKED_BOOT_COMPLETE_MSG:
                dispatchLockedBootComplete(msg.arg1);
                break;
            case START_USER_SWITCH_UI_MSG:
                final Pair<UserInfo, UserInfo> fromToUserPair = (Pair<UserInfo, UserInfo>) msg.obj;
                logUserJourneyInfo(fromToUserPair.first, fromToUserPair.second,
                        USER_JOURNEY_USER_SWITCH_UI);
                logUserLifecycleEvent(fromToUserPair.second.id, USER_LIFECYCLE_EVENT_SWITCH_USER,
                        USER_LIFECYCLE_EVENT_STATE_BEGIN);
                showUserSwitchDialog(fromToUserPair);
                break;
            case CLEAR_USER_JOURNEY_SESSION_MSG:
                logAndClearSessionId(msg.arg1);
                break;
        }
        return false;
    }

    /**
     * statsd helper method for logging the start of a user journey via a UserLifecycleEventOccurred
     * atom given the originating and targeting users for the journey.
     */
    private void logUserJourneyInfo(UserInfo origin, UserInfo target, @UserJourney int journey) {
        final long newSessionId = ThreadLocalRandom.current().nextLong(1, Long.MAX_VALUE);
        synchronized (mUserIdToUserJourneyMap) {
            UserJourneySession userJourneySession = mUserIdToUserJourneyMap.get(target.id);
            if (userJourneySession != null) {
                // TODO(b/157007231): Move this logic to a separate class/file.
                if ((userJourneySession.mJourney == USER_JOURNEY_USER_SWITCH_UI
                        && journey == USER_JOURNEY_USER_START)
                        || (userJourneySession.mJourney == USER_JOURNEY_USER_SWITCH_FG
                                && journey == USER_JOURNEY_USER_START)) {
                    /*
                     * There is already a user switch journey, and a user start journey for the same
                     * target user received. User start journey is most likely a part of user switch
                     * journey so no need to create a new journey for user start.
                     */
                    if (DEBUG_MU) {
                        Slog.d(TAG, journey + " not logged as it is expected to be part of "
                                + userJourneySession.mJourney);
                    }
                    return;
                }
                /*
                 * Possible reasons for this condition to be true:
                 * - A user switch journey is received while another user switch journey is in
                 *   process for the same user.
                 * - A user switch journey is received while user start journey is in process for
                 *   the same user.
                 * - A user start journey is received while another user start journey is in process
                 *   for the same user.
                 * In all cases potentially an incomplete, timed-out session or multiple
                 * simultaneous requests. It is not possible to keep track of multiple sessions for
                 * the same user, so previous session is abandoned.
                 */
                FrameworkStatsLog.write(FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED,
                        userJourneySession.mSessionId, target.id, USER_LIFECYCLE_EVENT_UNKNOWN,
                        USER_LIFECYCLE_EVENT_STATE_NONE);
            }

            if (DEBUG_MU) {
                Slog.d(TAG,
                        "Starting a new journey: " + journey + " with session id: " + newSessionId);
            }

            userJourneySession = new UserJourneySession(newSessionId, journey);
            mUserIdToUserJourneyMap.put(target.id, userJourneySession);
            /*
             * User lifecyle journey would be complete when {@code #clearSessionId} is called after
             * the last expected lifecycle event for the journey. It may be possible that the last
             * event is not called, e.g., user not unlocked after user switching. In such cases user
             * journey is cleared after {@link USER_JOURNEY_TIMEOUT}.
             */
            mHandler.removeMessages(CLEAR_USER_JOURNEY_SESSION_MSG);
            mHandler.sendMessageDelayed(mHandler.obtainMessage(CLEAR_USER_JOURNEY_SESSION_MSG,
                    target.id), USER_JOURNEY_TIMEOUT_MS);
        }

        FrameworkStatsLog.write(FrameworkStatsLog.USER_LIFECYCLE_JOURNEY_REPORTED, newSessionId,
                journey, origin != null ? origin.id : -1,
                target.id, UserManager.getUserTypeForStatsd(target.userType), target.flags);
    }

    /**
     * statsd helper method for logging the given event for the UserLifecycleEventOccurred statsd
     * atom.
     */
    private void logUserLifecycleEvent(@UserIdInt int userId, @UserLifecycleEvent int event,
            @UserLifecycleEventState int eventState) {
        final long sessionId;
        synchronized (mUserIdToUserJourneyMap) {
            final UserJourneySession userJourneySession = mUserIdToUserJourneyMap.get(userId);
            if (userJourneySession == null || userJourneySession.mSessionId == INVALID_SESSION_ID) {
                Slog.w(TAG, "UserLifecycleEvent " + event
                        + " received without an active userJourneySession.");
                return;
            }
            sessionId = userJourneySession.mSessionId;
        }

        FrameworkStatsLog.write(FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED, sessionId, userId,
                event, eventState);
    }

    /**
     * Clears the {@link UserJourneySession} for a given {@link UserIdInt} and {@link UserJourney}.
     */
    private void clearSessionId(@UserIdInt int userId, @UserJourney int journey) {
        synchronized (mUserIdToUserJourneyMap) {
            final UserJourneySession userJourneySession = mUserIdToUserJourneyMap.get(userId);
            if (userJourneySession != null && userJourneySession.mJourney == journey) {
                clearSessionId(userId);
            }
        }
    }

    /**
     * Clears the {@link UserJourneySession} for a given {@link UserIdInt}.
     */
    private void clearSessionId(@UserIdInt int userId) {
        synchronized (mUserIdToUserJourneyMap) {
            mHandler.removeMessages(CLEAR_USER_JOURNEY_SESSION_MSG);
            mUserIdToUserJourneyMap.delete(userId);
        }
    }

    /**
     * Log a final event of the {@link UserJourneySession} and clear it.
     */
    private void logAndClearSessionId(@UserIdInt int userId) {
        synchronized (mUserIdToUserJourneyMap) {
            final UserJourneySession userJourneySession = mUserIdToUserJourneyMap.get(userId);
            if (userJourneySession != null) {
                FrameworkStatsLog.write(FrameworkStatsLog.USER_LIFECYCLE_EVENT_OCCURRED,
                        userJourneySession.mSessionId, userId, USER_LIFECYCLE_EVENT_UNKNOWN,
                        USER_LIFECYCLE_EVENT_STATE_NONE);
            }
            clearSessionId(userId);
        }
    }

    /**
     * Helper class to store user journey and session id.
     *
     * <p> User journey tracks a chain of user lifecycle events occurring during different user
     * activities such as user start, user switch, and user creation.
     */
    // TODO(b/157007231): Move this class and user journey tracking logic to a separate file.
    private static class UserJourneySession {
        final long mSessionId;
        @UserJourney final int mJourney;

        UserJourneySession(long sessionId, @UserJourney int journey) {
            mJourney = journey;
            mSessionId = sessionId;
        }
    }

    private static class UserProgressListener extends IProgressListener.Stub {
        private volatile long mUnlockStarted;
        @Override
        public void onStarted(int id, Bundle extras) throws RemoteException {
            Slog.d(TAG, "Started unlocking user " + id);
            mUnlockStarted = SystemClock.uptimeMillis();
        }

        @Override
        public void onProgress(int id, int progress, Bundle extras) throws RemoteException {
            Slog.d(TAG, "Unlocking user " + id + " progress " + progress);
        }

        @Override
        public void onFinished(int id, Bundle extras) throws RemoteException {
            long unlockTime = SystemClock.uptimeMillis() - mUnlockStarted;

            // Report system user unlock time to perf dashboard
            if (id == UserHandle.USER_SYSTEM) {
                new TimingsTraceAndSlog().logDuration("SystemUserUnlock", unlockTime);
            } else {
                new TimingsTraceAndSlog().logDuration("User" + id + "Unlock", unlockTime);
            }
        }
    }

    @VisibleForTesting
    static class Injector {
        private final ActivityManagerService mService;
        private UserManagerService mUserManager;
        private UserManagerInternal mUserManagerInternal;

        Injector(ActivityManagerService service) {
            mService = service;
        }

        protected Handler getHandler(Handler.Callback callback) {
            return new Handler(mService.mHandlerThread.getLooper(), callback);
        }

        protected Handler getUiHandler(Handler.Callback callback) {
            return new Handler(mService.mUiHandler.getLooper(), callback);
        }

        protected Context getContext() {
            return mService.mContext;
        }

        protected LockPatternUtils getLockPatternUtils() {
            return new LockPatternUtils(getContext());
        }

        protected int broadcastIntent(Intent intent, String resolvedType,
                IIntentReceiver resultTo, int resultCode, String resultData,
                Bundle resultExtras, String[] requiredPermissions, int appOp, Bundle bOptions,
                boolean ordered, boolean sticky, int callingPid, int callingUid, int realCallingUid,
                int realCallingPid, @UserIdInt int userId) {

            int logUserId = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, UserHandle.USER_NULL);
            if (logUserId == UserHandle.USER_NULL) {
                logUserId = userId;
            }
            EventLog.writeEvent(EventLogTags.UC_SEND_USER_BROADCAST, logUserId, intent.getAction());

            // TODO b/64165549 Verify that mLock is not held before calling AMS methods
            synchronized (mService) {
                return mService.broadcastIntentLocked(null, null, null, intent, resolvedType,
                        resultTo, resultCode, resultData, resultExtras, requiredPermissions, appOp,
                        bOptions, ordered, sticky, callingPid, callingUid, realCallingUid,
                        realCallingPid, userId);
            }
        }

        int checkCallingPermission(String permission) {
            return mService.checkCallingPermission(permission);
        }

        WindowManagerService getWindowManager() {
            return mService.mWindowManager;
        }
        void activityManagerOnUserStopped(@UserIdInt int userId) {
            LocalServices.getService(ActivityTaskManagerInternal.class).onUserStopped(userId);
        }

        void systemServiceManagerCleanupUser(@UserIdInt int userId) {
            mService.mSystemServiceManager.cleanupUser(userId);
        }

        protected UserManagerService getUserManager() {
            if (mUserManager == null) {
                IBinder b = ServiceManager.getService(Context.USER_SERVICE);
                mUserManager = (UserManagerService) IUserManager.Stub.asInterface(b);
            }
            return mUserManager;
        }

        UserManagerInternal getUserManagerInternal() {
            if (mUserManagerInternal == null) {
                mUserManagerInternal = LocalServices.getService(UserManagerInternal.class);
            }
            return mUserManagerInternal;
        }

        KeyguardManager getKeyguardManager() {
            return mService.mContext.getSystemService(KeyguardManager.class);
        }

        void batteryStatsServiceNoteEvent(int code, String name, int uid) {
            mService.mBatteryStatsService.noteEvent(code, name, uid);
        }

        boolean isRuntimeRestarted() {
            return mService.mSystemServiceManager.isRuntimeRestarted();
        }

        SystemServiceManager getSystemServiceManager() {
            return mService.mSystemServiceManager;
        }

        boolean isFirstBootOrUpgrade() {
            IPackageManager pm = AppGlobals.getPackageManager();
            try {
                return pm.isFirstBoot() || pm.isDeviceUpgrading();
            } catch (RemoteException e) {
                throw e.rethrowFromSystemServer();
            }
        }

        void sendPreBootBroadcast(@UserIdInt int userId, boolean quiet, final Runnable onFinish) {
            EventLog.writeEvent(EventLogTags.UC_SEND_USER_BROADCAST,
                    userId, Intent.ACTION_PRE_BOOT_COMPLETED);
            new PreBootBroadcaster(mService, userId, null, quiet) {
                @Override
                public void onFinished() {
                    onFinish.run();
                }
            }.sendNext();
        }

        void activityManagerForceStopPackage(@UserIdInt int userId, String reason) {
            synchronized (mService) {
                mService.forceStopPackageLocked(null, -1, false, false, true, false, false,
                        userId, reason);
            }
        };

        int checkComponentPermission(String permission, int pid, int uid, int owningUid,
                boolean exported) {
            return mService.checkComponentPermission(permission, pid, uid, owningUid, exported);
        }

        protected void startHomeActivity(@UserIdInt int userId, String reason) {
            mService.mAtmInternal.startHomeActivity(userId, reason);
        }

        void startUserWidgets(@UserIdInt int userId) {
            AppWidgetManagerInternal awm = LocalServices.getService(AppWidgetManagerInternal.class);
            if (awm != null) {
                // Out of band, because this is called during a sequence with
                // sensitive cross-service lock management
                FgThread.getHandler().post(() -> {
                    awm.unlockUser(userId);
                });
            }
        }

        void updateUserConfiguration() {
            mService.mAtmInternal.updateUserConfiguration();
        }

        void clearBroadcastQueueForUser(@UserIdInt int userId) {
            synchronized (mService) {
                mService.clearBroadcastQueueForUserLocked(userId);
            }
        }

        void loadUserRecents(@UserIdInt int userId) {
            mService.mAtmInternal.loadRecentTasksForUser(userId);
        }

        void startPersistentApps(int matchFlags) {
            mService.startPersistentApps(matchFlags);
        }

        void installEncryptionUnawareProviders(@UserIdInt int userId) {
            mService.installEncryptionUnawareProviders(userId);
        }

        void showUserSwitchingDialog(UserInfo fromUser, UserInfo toUser,
                String switchingFromSystemUserMessage, String switchingToSystemUserMessage) {
            if (!mService.mContext.getPackageManager()
                    .hasSystemFeature(PackageManager.FEATURE_AUTOMOTIVE)) {
                final Dialog d = new UserSwitchingDialog(mService, mService.mContext, fromUser,
                        toUser, true /* above system */, switchingFromSystemUserMessage,
                        switchingToSystemUserMessage);
                d.show();
            }
        }

        void reportGlobalUsageEventLocked(int event) {
            synchronized (mService) {
                mService.reportGlobalUsageEventLocked(event);
            }
        }

        void reportCurWakefulnessUsageEvent() {
            synchronized (mService) {
                mService.reportCurWakefulnessUsageEventLocked();
            }
        }

        void stackSupervisorRemoveUser(@UserIdInt int userId) {
            mService.mAtmInternal.removeUser(userId);
        }

        protected boolean stackSupervisorSwitchUser(@UserIdInt int userId, UserState uss) {
            return mService.mAtmInternal.switchUser(userId, uss);
        }

        protected void stackSupervisorResumeFocusedStackTopActivity() {
            mService.mAtmInternal.resumeTopActivities(false /* scheduleIdle */);
        }

        protected void clearAllLockedTasks(String reason) {
            mService.mAtmInternal.clearLockedTasks(reason);
        }

        protected boolean isCallerRecents(int callingUid) {
            return mService.mAtmInternal.isCallerRecents(callingUid);
        }

        protected IStorageManager getStorageManager() {
            return IStorageManager.Stub.asInterface(ServiceManager.getService("mount"));
        }
    }
}