From 2cde8d7196e18efd7bce4eb688ee80a5c87814cd Mon Sep 17 00:00:00 2001
From: Jing Ji <jji@google.com>
Date: Mon, 14 Feb 2022 09:55:39 -0800
Subject: [PATCH] Move the init of trackers in the app restriction controller
 to bg.

Also postpone the initialization of the permission tracker as it
doesn't need to be done before system ready.

Bug: 219140433
Test: BootTimeTest
Change-Id: I2c13252ec6ded1f51f3a13832c8c0a55da359b95
---
 .../server/am/AppPermissionTracker.java       | 53 ++++++++++++-------
 .../server/am/AppRestrictionController.java   | 36 +++++++++++--
 .../server/am/BaseAppStateTracker.java        |  6 +++
 .../server/am/BackgroundRestrictionTest.java  |  5 ++
 4 files changed, 78 insertions(+), 22 deletions(-)

diff --git a/services/core/java/com/android/server/am/AppPermissionTracker.java b/services/core/java/com/android/server/am/AppPermissionTracker.java
index 7f48d527ac776..69f70ca0d0e08 100644
--- a/services/core/java/com/android/server/am/AppPermissionTracker.java
+++ b/services/core/java/com/android/server/am/AppPermissionTracker.java
@@ -64,6 +64,8 @@ final class AppPermissionTracker extends BaseAppStateTracker<AppPermissionPolicy
     @GuardedBy("mLock")
     private SparseArray<ArraySet<String>> mUidGrantedPermissionsInMonitor = new SparseArray<>();
 
+    private volatile boolean mLockedBootCompleted = false;
+
     AppPermissionTracker(Context context, AppRestrictionController controller) {
         this(context, controller, null, null);
     }
@@ -85,20 +87,20 @@ final class AppPermissionTracker extends BaseAppStateTracker<AppPermissionPolicy
         final PackageManagerInternal pmi = mInjector.getPackageManagerInternal();
         final PermissionManagerServiceInternal pm = mInjector.getPermissionManagerServiceInternal();
         final String[] permissions = mInjector.getPolicy().getBgPermissionsInMonitor();
+        final SparseArray<ArraySet<String>> uidPerms = mUidGrantedPermissionsInMonitor;
         for (int userId : allUsers) {
             final List<ApplicationInfo> apps = pmi.getInstalledApplications(0, userId, SYSTEM_UID);
             if (apps == null) {
                 continue;
             }
-            synchronized (mLock) {
-                final SparseArray<ArraySet<String>> uidPerms = mUidGrantedPermissionsInMonitor;
-                final long now = SystemClock.elapsedRealtime();
-                for (int i = 0, size = apps.size(); i < size; i++) {
-                    final ApplicationInfo ai = apps.get(i);
-                    for (String permission : permissions) {
-                        if (pm.checkUidPermission(ai.uid, permission) != PERMISSION_GRANTED) {
-                            continue;
-                        }
+            final long now = SystemClock.elapsedRealtime();
+            for (int i = 0, size = apps.size(); i < size; i++) {
+                final ApplicationInfo ai = apps.get(i);
+                for (String permission : permissions) {
+                    if (pm.checkUidPermission(ai.uid, permission) != PERMISSION_GRANTED) {
+                        continue;
+                    }
+                    synchronized (mLock) {
                         ArraySet<String> grantedPermissions = uidPerms.get(ai.uid);
                         if (grantedPermissions == null) {
                             grantedPermissions = new ArraySet<String>();
@@ -132,25 +134,30 @@ final class AppPermissionTracker extends BaseAppStateTracker<AppPermissionPolicy
     private void handlePermissionsChanged(int uid) {
         final String[] permissions = mInjector.getPolicy().getBgPermissionsInMonitor();
         if (permissions != null && permissions.length > 0) {
+            final PermissionManagerServiceInternal pm =
+                    mInjector.getPermissionManagerServiceInternal();
+            final boolean[] states = new boolean[permissions.length];
+            for (int i = 0; i < permissions.length; i++) {
+                states[i] = pm.checkUidPermission(uid, permissions[i]) == PERMISSION_GRANTED;
+                if (DEBUG_PERMISSION_TRACKER) {
+                    Slog.i(TAG, UserHandle.formatUid(uid) + " " + permissions[i] + "=" + states[i]);
+                }
+            }
             synchronized (mLock) {
-                handlePermissionsChangedLocked(uid);
+                handlePermissionsChangedLocked(uid, permissions, states);
             }
         }
     }
 
     @GuardedBy("mLock")
-    private void handlePermissionsChangedLocked(int uid) {
-        final PermissionManagerServiceInternal pm = mInjector.getPermissionManagerServiceInternal();
+    private void handlePermissionsChangedLocked(int uid, String[] permissions, boolean[] states) {
         final int index = mUidGrantedPermissionsInMonitor.indexOfKey(uid);
         ArraySet<String> grantedPermissions = index >= 0
                 ? mUidGrantedPermissionsInMonitor.valueAt(index) : null;
-        final String[] permissions = mInjector.getPolicy().getBgPermissionsInMonitor();
         final long now = SystemClock.elapsedRealtime();
-        for (String permission: permissions) {
-            boolean granted = pm.checkUidPermission(uid, permission) == PERMISSION_GRANTED;
-            if (DEBUG_PERMISSION_TRACKER) {
-                Slog.i(TAG, UserHandle.formatUid(uid) + " " + permission + "=" + granted);
-            }
+        for (int i = 0; i < permissions.length; i++) {
+            final String permission = permissions[i];
+            final boolean granted = states[i];
             boolean changed = false;
             if (granted) {
                 if (grantedPermissions == null) {
@@ -200,6 +207,10 @@ final class AppPermissionTracker extends BaseAppStateTracker<AppPermissionPolicy
     }
 
     private void onPermissionTrackerEnabled(boolean enabled) {
+        if (!mLockedBootCompleted) {
+            // Not ready, bail out.
+            return;
+        }
         final PermissionManager pm = mInjector.getPermissionManager();
         if (enabled) {
             pm.addOnPermissionsChangeListener(this);
@@ -210,6 +221,12 @@ final class AppPermissionTracker extends BaseAppStateTracker<AppPermissionPolicy
         }
     }
 
+    @Override
+    void onLockedBootCompleted() {
+        mLockedBootCompleted = true;
+        onPermissionTrackerEnabled(mInjector.getPolicy().isEnabled());
+    }
+
     @Override
     void dump(PrintWriter pw, String prefix) {
         pw.print(prefix);
diff --git a/services/core/java/com/android/server/am/AppRestrictionController.java b/services/core/java/com/android/server/am/AppRestrictionController.java
index 1129c19bce873..2ffd48739e47f 100644
--- a/services/core/java/com/android/server/am/AppRestrictionController.java
+++ b/services/core/java/com/android/server/am/AppRestrictionController.java
@@ -71,6 +71,7 @@ import static android.os.PowerExemptionManager.REASON_SYSTEM_MODULE;
 import static android.os.PowerExemptionManager.REASON_SYSTEM_UID;
 import static android.os.PowerExemptionManager.reasonCodeToString;
 import static android.os.Process.SYSTEM_UID;
+import static android.os.Process.THREAD_PRIORITY_BACKGROUND;
 
 import static com.android.internal.notification.SystemNotificationChannels.ABUSIVE_BACKGROUND_APPS;
 import static com.android.server.am.ActivityManagerDebugConfig.TAG_AM;
@@ -792,7 +793,7 @@ public final class AppRestrictionController {
         mInjector = injector;
         mContext = injector.getContext();
         mActivityManagerService = service;
-        mBgHandlerThread = new HandlerThread("bgres-controller");
+        mBgHandlerThread = new HandlerThread("bgres-controller", THREAD_PRIORITY_BACKGROUND);
         mBgHandlerThread.start();
         mBgHandler = new BgHandler(mBgHandlerThread.getLooper(), injector);
         mBgExecutor = new HandlerExecutor(mBgHandler);
@@ -816,9 +817,11 @@ public final class AppRestrictionController {
         mInjector.getAppStandbyInternal().addListener(mAppIdleStateChangeListener);
         mInjector.getRoleManager().addOnRoleHoldersChangedListenerAsUser(mBgExecutor,
                 mRoleHolderChangedListener, UserHandle.ALL);
-        for (int i = 0, size = mAppStateTrackers.size(); i < size; i++) {
-            mAppStateTrackers.get(i).onSystemReady();
-        }
+        mInjector.scheduleInitTrackers(mBgHandler, () -> {
+            for (int i = 0, size = mAppStateTrackers.size(); i < size; i++) {
+                mAppStateTrackers.get(i).onSystemReady();
+            }
+        });
     }
 
     @VisibleForTesting
@@ -2137,6 +2140,10 @@ public final class AppRestrictionController {
             }
             return null;
         }
+
+        void scheduleInitTrackers(Handler handler, Runnable initializers) {
+            handler.post(initializers);
+        }
     }
 
     private void registerForSystemBroadcasts() {
@@ -2221,6 +2228,21 @@ public final class AppRestrictionController {
         userFilter.addAction(Intent.ACTION_USER_REMOVED);
         userFilter.addAction(Intent.ACTION_UID_REMOVED);
         mContext.registerReceiverForAllUsers(broadcastReceiver, userFilter, null, mBgHandler);
+        final BroadcastReceiver bootReceiver = new BroadcastReceiver() {
+            @Override
+            public void onReceive(Context context, Intent intent) {
+                final String action = intent.getAction();
+                switch (intent.getAction()) {
+                    case Intent.ACTION_LOCKED_BOOT_COMPLETED: {
+                        onLockedBootCompleted();
+                    } break;
+                }
+            }
+        };
+        final IntentFilter bootFilter = new IntentFilter();
+        bootFilter.addAction(Intent.ACTION_LOCKED_BOOT_COMPLETED);
+        mContext.registerReceiverAsUser(bootReceiver, UserHandle.SYSTEM,
+                bootFilter, null, mBgHandler);
     }
 
     void forEachTracker(Consumer<BaseAppStateTracker> sink) {
@@ -2275,6 +2297,12 @@ public final class AppRestrictionController {
         mRestrictionSettings.removeUid(uid);
     }
 
+    private void onLockedBootCompleted() {
+        for (int i = 0, size = mAppStateTrackers.size(); i < size; i++) {
+            mAppStateTrackers.get(i).onLockedBootCompleted();
+        }
+    }
+
     boolean isBgAutoRestrictedBucketFeatureFlagEnabled() {
         return mConstantsObserver.mBgAutoRestrictedBucket;
     }
diff --git a/services/core/java/com/android/server/am/BaseAppStateTracker.java b/services/core/java/com/android/server/am/BaseAppStateTracker.java
index 482d69751d700..0fada53d622e4 100644
--- a/services/core/java/com/android/server/am/BaseAppStateTracker.java
+++ b/services/core/java/com/android/server/am/BaseAppStateTracker.java
@@ -203,6 +203,12 @@ public abstract class BaseAppStateTracker<T extends BaseAppStatePolicy> {
     void onUserRemoved(final @UserIdInt int userId) {
     }
 
+    /**
+     * Called when the system sends LOCKED_BOOT_COMPLETED.
+     */
+    void onLockedBootCompleted() {
+    }
+
     /**
      * Called when a device config property in the activity manager namespace
      * has changed.
diff --git a/services/tests/mockingservicestests/src/com/android/server/am/BackgroundRestrictionTest.java b/services/tests/mockingservicestests/src/com/android/server/am/BackgroundRestrictionTest.java
index 936940fcde6e8..e6bb0ce318fe1 100644
--- a/services/tests/mockingservicestests/src/com/android/server/am/BackgroundRestrictionTest.java
+++ b/services/tests/mockingservicestests/src/com/android/server/am/BackgroundRestrictionTest.java
@@ -2648,6 +2648,11 @@ public final class BackgroundRestrictionTest {
         AppPermissionTracker getAppPermissionTracker() {
             return mAppPermissionTracker;
         }
+
+        @Override
+        void scheduleInitTrackers(Handler handler, Runnable initializers) {
+            initializers.run();
+        }
     }
 
     private class TestBaseTrackerInjector<T extends BaseAppStatePolicy>