Support dynamic feature flag config

For CTS testing purposes, have the DeviceConfig feature flag control
whether app hibernation behavior is stubbed rather than whether the
service itself is started. This allows us to change the feature flag in
tests without restarting system_server

Bug: 175830282
Test: atest AppHibernationServiceTest
Change-Id: Id9ea16345cac84a069ff53939cef1564a585c466

3 files changed, 50 insertions, 7 deletions

diff --git a/services/core/java/com/android/server/apphibernation/AppHibernationService.java b/services/core/java/com/android/server/apphibernation/AppHibernationService.java
index e97f0b47380a..ab745164bbdb 100644
--- a/services/core/java/com/android/server/apphibernation/AppHibernationService.java
+++ b/services/core/java/com/android/server/apphibernation/AppHibernationService.java
@@ -23,9 +23,12 @@ import static android.content.Intent.EXTRA_REPLACING;
 import static android.content.pm.PackageManager.MATCH_ANY_USER;
 import static android.provider.DeviceConfig.NAMESPACE_APP_HIBERNATION;
 
+import static com.android.server.apphibernation.AppHibernationConstants.KEY_APP_HIBERNATION_ENABLED;
+
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.app.ActivityManager;
+import android.app.ActivityThread;
 import android.app.IActivityManager;
 import android.apphibernation.IAppHibernationService;
 import android.content.BroadcastReceiver;
@@ -45,6 +48,8 @@ import android.os.Trace;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.DeviceConfig;
+import android.provider.DeviceConfig.Properties;
+import android.text.TextUtils;
 import android.util.ArrayMap;
 import android.util.ArraySet;
 import android.util.Slog;
@@ -93,6 +98,9 @@ public final class AppHibernationService extends SystemService {
     private final HibernationStateDiskStore<GlobalLevelState> mGlobalLevelHibernationDiskStore;
     private final Injector mInjector;
 
+    @VisibleForTesting
+    boolean mIsServiceEnabled;
+
     /**
      * Initializes the system service.
      * <p>
@@ -139,6 +147,13 @@ public final class AppHibernationService extends SystemService {
                 initializeGlobalHibernationStates(states);
             }
         }
+        if (phase == SystemService.PHASE_SYSTEM_SERVICES_READY) {
+            mIsServiceEnabled = isAppHibernationEnabled();
+            DeviceConfig.addOnPropertiesChangedListener(
+                    NAMESPACE_APP_HIBERNATION,
+                    ActivityThread.currentApplication().getMainExecutor(),
+                    this::onDeviceConfigChanged);
+        }
     }
 
     /**
@@ -149,6 +164,10 @@ public final class AppHibernationService extends SystemService {
      * @return true if package is hibernating for the user
      */
     boolean isHibernatingForUser(String packageName, int userId) {
+        if (!checkHibernationEnabled("isHibernatingForUser")) {
+            return false;
+        }
+
         userId = handleIncomingUser(userId, "isHibernating");
         if (!mUserManager.isUserUnlockingOrUnlocked(userId)) {
             Slog.e(TAG, "Attempt to get hibernation state of stopped or nonexistent user "
@@ -174,6 +193,9 @@ public final class AppHibernationService extends SystemService {
      * @param packageName package to check
      */
     boolean isHibernatingGlobally(String packageName) {
+        if (!checkHibernationEnabled("isHibernatingGlobally")) {
+            return false;
+        }
         synchronized (mLock) {
             GlobalLevelState state = mGlobalHibernationStates.get(packageName);
             if (state == null) {
@@ -192,6 +214,9 @@ public final class AppHibernationService extends SystemService {
      * @param isHibernating new hibernation state
      */
     void setHibernatingForUser(String packageName, int userId, boolean isHibernating) {
+        if (!checkHibernationEnabled("setHibernatingForUser")) {
+            return;
+        }
         userId = handleIncomingUser(userId, "setHibernating");
         if (!mUserManager.isUserUnlockingOrUnlocked(userId)) {
             Slog.w(TAG, "Attempt to set hibernation state for a stopped or nonexistent user "
@@ -229,6 +254,9 @@ public final class AppHibernationService extends SystemService {
      * @param isHibernating new hibernation state
      */
     void setHibernatingGlobally(String packageName, boolean isHibernating) {
+        if (!checkHibernationEnabled("setHibernatingGlobally")) {
+            return;
+        }
         synchronized (mLock) {
             GlobalLevelState state = mGlobalHibernationStates.get(packageName);
             if (state == null) {
@@ -444,6 +472,15 @@ public final class AppHibernationService extends SystemService {
         }
     }
 
+    private void onDeviceConfigChanged(Properties properties) {
+        for (String key : properties.getKeyset()) {
+            if (TextUtils.equals(KEY_APP_HIBERNATION_ENABLED, key)) {
+                mIsServiceEnabled = isAppHibernationEnabled();
+                break;
+            }
+        }
+    }
+
     /**
      * Private helper method to get the real user id and enforce permission checks.
      *
@@ -461,6 +498,13 @@ public final class AppHibernationService extends SystemService {
         }
     }
 
+    private boolean checkHibernationEnabled(String methodName) {
+        if (!mIsServiceEnabled) {
+            Slog.w(TAG, String.format("Attempted to call %s on unsupported device.", methodName));
+        }
+        return mIsServiceEnabled;
+    }
+
     private final AppHibernationServiceStub mServiceStub = new AppHibernationServiceStub(this);
 
     static final class AppHibernationServiceStub extends IAppHibernationService.Stub {
@@ -536,7 +580,7 @@ public final class AppHibernationService extends SystemService {
     public static boolean isAppHibernationEnabled() {
         return DeviceConfig.getBoolean(
                 NAMESPACE_APP_HIBERNATION,
-                AppHibernationConstants.KEY_APP_HIBERNATION_ENABLED,
+                KEY_APP_HIBERNATION_ENABLED,
                 false /* defaultValue */);
     }
 
diff --git a/services/java/com/android/server/SystemServer.java b/services/java/com/android/server/SystemServer.java
index 62c3f43d2676..d6ddbb1f0685 100644
--- a/services/java/com/android/server/SystemServer.java
+++ b/services/java/com/android/server/SystemServer.java
@@ -97,7 +97,6 @@ import com.android.internal.util.FrameworkStatsLog;
 import com.android.internal.widget.ILockSettings;
 import com.android.server.am.ActivityManagerService;
 import com.android.server.appbinding.AppBindingService;
-import com.android.server.apphibernation.AppHibernationService;
 import com.android.server.attention.AttentionManagerService;
 import com.android.server.audio.AudioService;
 import com.android.server.biometrics.AuthService;
@@ -1873,11 +1872,9 @@ public final class SystemServer {
             mSystemServiceManager.startService(VOICE_RECOGNITION_MANAGER_SERVICE_CLASS);
             t.traceEnd();
 
-            if (AppHibernationService.isAppHibernationEnabled()) {
-                t.traceBegin("StartAppHibernationService");
-                mSystemServiceManager.startService(APP_HIBERNATION_SERVICE_CLASS);
-                t.traceEnd();
-            }
+            t.traceBegin("StartAppHibernationService");
+            mSystemServiceManager.startService(APP_HIBERNATION_SERVICE_CLASS);
+            t.traceEnd();
 
             if (GestureLauncherService.isGestureLauncherEnabled(context.getResources())) {
                 t.traceBegin("StartGestureLauncher");
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 1328b91d03f9..07f67327b2bf 100644
--- a/services/tests/servicestests/src/com/android/server/apphibernation/AppHibernationServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/apphibernation/AppHibernationServiceTest.java
@@ -110,6 +110,8 @@ public final class AppHibernationServiceTest {
         UserInfo userInfo = addUser(USER_ID_1);
         mAppHibernationService.onUserUnlocking(new SystemService.TargetUser(userInfo));
         doReturn(true).when(mUserManager).isUserUnlockingOrUnlocked(USER_ID_1);
+
+        mAppHibernationService.mIsServiceEnabled = true;
     }
 
     @Test