Move disk reads to background

Move disk reading to background to improve performance on user
unlocking.

Bug: 182098676
Test: atest AppHibernationServiceTest
Change-Id: I087bd9d29f4f90c818a03648ee75e3cbfb2ded41

3 files changed, 63 insertions, 27 deletions

diff --git a/services/core/java/com/android/server/apphibernation/AppHibernationService.java b/services/core/java/com/android/server/apphibernation/AppHibernationService.java
index b3373d0bb536..351231f34c4b 100644
--- a/services/core/java/com/android/server/apphibernation/AppHibernationService.java
+++ b/services/core/java/com/android/server/apphibernation/AppHibernationService.java
@@ -69,6 +69,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 
@@ -101,6 +102,7 @@ public final class AppHibernationService extends SystemService {
     private final Map<String, GlobalLevelState> mGlobalHibernationStates = new ArrayMap<>();
     private final HibernationStateDiskStore<GlobalLevelState> mGlobalLevelHibernationDiskStore;
     private final Injector mInjector;
+    private final Executor mBackgroundExecutor;
 
     @VisibleForTesting
     boolean mIsServiceEnabled;
@@ -126,6 +128,7 @@ public final class AppHibernationService extends SystemService {
         mIActivityManager = injector.getActivityManager();
         mUserManager = injector.getUserManager();
         mGlobalLevelHibernationDiskStore = injector.getGlobalLevelDiskStore();
+        mBackgroundExecutor = injector.getBackgroundExecutor();
         mInjector = injector;
 
         final Context userAllContext = mContext.createContextAsUser(UserHandle.ALL, 0 /* flags */);
@@ -147,11 +150,13 @@ public final class AppHibernationService extends SystemService {
     @Override
     public void onBootPhase(int phase) {
         if (phase == PHASE_BOOT_COMPLETED) {
-            List<GlobalLevelState> states =
-                    mGlobalLevelHibernationDiskStore.readHibernationStates();
-            synchronized (mLock) {
-                initializeGlobalHibernationStates(states);
-            }
+            mBackgroundExecutor.execute(() -> {
+                List<GlobalLevelState> states =
+                        mGlobalLevelHibernationDiskStore.readHibernationStates();
+                synchronized (mLock) {
+                    initializeGlobalHibernationStates(states);
+                }
+            });
         }
         if (phase == SystemService.PHASE_SYSTEM_SERVICES_READY) {
             mIsServiceEnabled = isAppHibernationEnabled();
@@ -170,16 +175,15 @@ public final class AppHibernationService extends SystemService {
      * @return true if package is hibernating for the user
      */
     boolean isHibernatingForUser(String packageName, int userId) {
-        if (!checkHibernationEnabled("isHibernatingForUser")) {
+        String methodName = "isHibernatingForUser";
+        if (!checkHibernationEnabled(methodName)) {
             return false;
         }
         getContext().enforceCallingOrSelfPermission(
                 android.Manifest.permission.MANAGE_APP_HIBERNATION,
                 "Caller does not have MANAGE_APP_HIBERNATION permission.");
-        userId = handleIncomingUser(userId, "isHibernating");
-        if (!mUserManager.isUserUnlockingOrUnlocked(userId)) {
-            Slog.e(TAG, "Attempt to get hibernation state of stopped or nonexistent user "
-                    + userId);
+        userId = handleIncomingUser(userId, methodName);
+        if (!checkUserStatesExist(userId, methodName)) {
             return false;
         }
         synchronized (mLock) {
@@ -225,16 +229,15 @@ public final class AppHibernationService extends SystemService {
      * @param isHibernating new hibernation state
      */
     void setHibernatingForUser(String packageName, int userId, boolean isHibernating) {
-        if (!checkHibernationEnabled("setHibernatingForUser")) {
+        String methodName = "setHibernatingForUser";
+        if (!checkHibernationEnabled(methodName)) {
             return;
         }
         getContext().enforceCallingOrSelfPermission(
                 android.Manifest.permission.MANAGE_APP_HIBERNATION,
                 "Caller does not have MANAGE_APP_HIBERNATION permission.");
-        userId = handleIncomingUser(userId, "setHibernating");
-        if (!mUserManager.isUserUnlockingOrUnlocked(userId)) {
-            Slog.w(TAG, "Attempt to set hibernation state for a stopped or nonexistent user "
-                    + userId);
+        userId = handleIncomingUser(userId, methodName);
+        if (!checkUserStatesExist(userId, methodName)) {
             return;
         }
         synchronized (mLock) {
@@ -298,16 +301,15 @@ public final class AppHibernationService extends SystemService {
      */
     @NonNull List<String> getHibernatingPackagesForUser(int userId) {
         ArrayList<String> hibernatingPackages = new ArrayList<>();
-        if (!checkHibernationEnabled("getHibernatingPackagesForUser")) {
+        String methodName = "getHibernatingPackagesForUser";
+        if (!checkHibernationEnabled(methodName)) {
             return hibernatingPackages;
         }
         getContext().enforceCallingOrSelfPermission(
                 android.Manifest.permission.MANAGE_APP_HIBERNATION,
                 "Caller does not have MANAGE_APP_HIBERNATION permission.");
-        userId = handleIncomingUser(userId, "getHibernatingPackagesForUser");
-        if (!mUserManager.isUserUnlockingOrUnlocked(userId)) {
-            Slog.w(TAG, "Attempt to get hibernating packages for a stopped or nonexistent user "
-                    + userId);
+        userId = handleIncomingUser(userId, methodName);
+        if (!checkUserStatesExist(userId, methodName)) {
             return hibernatingPackages;
         }
         synchronized (mLock) {
@@ -477,10 +479,15 @@ public final class AppHibernationService extends SystemService {
         HibernationStateDiskStore<UserLevelState> diskStore =
                 mInjector.getUserLevelDiskStore(userId);
         mUserDiskStores.put(userId, diskStore);
-        List<UserLevelState> storedStates = diskStore.readHibernationStates();
-        synchronized (mLock) {
-            initializeUserHibernationStates(userId, storedStates);
-        }
+        mBackgroundExecutor.execute(() -> {
+            List<UserLevelState> storedStates = diskStore.readHibernationStates();
+            synchronized (mLock) {
+                // Ensure user hasn't stopped in the time to execute.
+                if (mUserManager.isUserUnlockingOrUnlocked(userId)) {
+                    initializeUserHibernationStates(userId, storedStates);
+                }
+            }
+        });
     }
 
     @Override
@@ -550,6 +557,20 @@ public final class AppHibernationService extends SystemService {
         }
     }
 
+    private boolean checkUserStatesExist(int userId, String methodName) {
+        if (!mUserManager.isUserUnlockingOrUnlocked(userId)) {
+            Slog.e(TAG, String.format(
+                    "Attempt to call %s on stopped or nonexistent user %d", methodName, userId));
+            return false;
+        }
+        if (!mUserStates.contains(userId)) {
+            Slog.w(TAG, String.format(
+                    "Attempt to call %s before states have been read from disk", methodName));
+            return false;
+        }
+        return true;
+    }
+
     private boolean checkHibernationEnabled(String methodName) {
         if (!mIsServiceEnabled) {
             Slog.w(TAG, String.format("Attempted to call %s on unsupported device.", methodName));
@@ -720,6 +741,8 @@ public final class AppHibernationService extends SystemService {
 
         UserManager getUserManager();
 
+        Executor getBackgroundExecutor();
+
         HibernationStateDiskStore<GlobalLevelState> getGlobalLevelDiskStore();
 
         HibernationStateDiskStore<UserLevelState> getUserLevelDiskStore(int userId);
@@ -758,6 +781,11 @@ public final class AppHibernationService extends SystemService {
         }
 
         @Override
+        public Executor getBackgroundExecutor() {
+            return mScheduledExecutorService;
+        }
+
+        @Override
         public HibernationStateDiskStore<GlobalLevelState> getGlobalLevelDiskStore() {
             File dir = new File(Environment.getDataSystemDirectory(), HIBERNATION_DIR_NAME);
             return new HibernationStateDiskStore<>(
diff --git a/services/core/java/com/android/server/apphibernation/HibernationStateDiskStore.java b/services/core/java/com/android/server/apphibernation/HibernationStateDiskStore.java
index c83659d2ff56..24cf43339847 100644
--- a/services/core/java/com/android/server/apphibernation/HibernationStateDiskStore.java
+++ b/services/core/java/com/android/server/apphibernation/HibernationStateDiskStore.java
@@ -109,6 +109,7 @@ class HibernationStateDiskStore<T> {
      * @return the parsed list of hibernation states, null if file does not exist
      */
     @Nullable
+    @WorkerThread
     List<T> readHibernationStates() {
         synchronized (this) {
             if (!mHibernationFile.exists()) {
diff --git a/services/tests/servicestests/src/com/android/server/apphibernation/AppHibernationServiceTest.java b/services/tests/servicestests/src/com/android/server/apphibernation/AppHibernationServiceTest.java
index 1b8ab2175458..2f0d71a2a579 100644
--- a/services/tests/servicestests/src/com/android/server/apphibernation/AppHibernationServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/apphibernation/AppHibernationServiceTest.java
@@ -58,6 +58,7 @@ import org.mockito.MockitoAnnotations;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.Executor;
 
 /**
  * Tests for {@link com.android.server.apphibernation.AppHibernationService}
@@ -116,8 +117,8 @@ public final class AppHibernationServiceTest {
         mAppHibernationService.onBootPhase(SystemService.PHASE_BOOT_COMPLETED);
 
         UserInfo userInfo = addUser(USER_ID_1);
-        mAppHibernationService.onUserUnlocking(new SystemService.TargetUser(userInfo));
         doReturn(true).when(mUserManager).isUserUnlockingOrUnlocked(USER_ID_1);
+        mAppHibernationService.onUserUnlocking(new SystemService.TargetUser(userInfo));
 
         mAppHibernationService.mIsServiceEnabled = true;
     }
@@ -150,8 +151,8 @@ public final class AppHibernationServiceTest {
             throws RemoteException {
         // WHEN a new user is added and a package from the user is hibernated
         UserInfo user2 = addUser(USER_ID_2);
-        mAppHibernationService.onUserUnlocking(new SystemService.TargetUser(user2));
         doReturn(true).when(mUserManager).isUserUnlockingOrUnlocked(USER_ID_2);
+        mAppHibernationService.onUserUnlocking(new SystemService.TargetUser(user2));
         mAppHibernationService.setHibernatingForUser(PACKAGE_NAME_1, USER_ID_2, true);
 
         // THEN the new user's package is hibernated
@@ -188,8 +189,8 @@ public final class AppHibernationServiceTest {
         // GIVEN an unlocked user with all packages installed
         UserInfo userInfo =
                 addUser(USER_ID_2, new String[]{PACKAGE_NAME_1, PACKAGE_NAME_2, PACKAGE_NAME_3});
-        mAppHibernationService.onUserUnlocking(new SystemService.TargetUser(userInfo));
         doReturn(true).when(mUserManager).isUserUnlockingOrUnlocked(USER_ID_2);
+        mAppHibernationService.onUserUnlocking(new SystemService.TargetUser(userInfo));
 
         // WHEN packages are hibernated for the user
         mAppHibernationService.setHibernatingForUser(PACKAGE_NAME_1, USER_ID_2, true);
@@ -259,6 +260,12 @@ public final class AppHibernationServiceTest {
         }
 
         @Override
+        public Executor getBackgroundExecutor() {
+            // Just execute immediately in tests.
+            return r -> r.run();
+        }
+
+        @Override
         public HibernationStateDiskStore<GlobalLevelState> getGlobalLevelDiskStore() {
             return Mockito.mock(HibernationStateDiskStore.class);
         }