Add a way to clear cached provider for tests in Settings class.

Bug: 38437704
Bug: 38433611
Test: manual
Change-Id: Id2803359644bd68a158294b6d801fc9cd316fc9f

core/java/android/provider/Settings.java

@@ -1779,6 +1779,12 @@ public final class Settings {
                 return mContentProvider;
             }
         }
+
+        public void clearProviderForTest() {
+            synchronized (mLock) {
+                mContentProvider = null;
+            }
+        }
     }
 
     // Thread-safe.
@@ -1994,6 +2000,16 @@ public final class Settings {
                 if (c != null) c.close();
             }
         }
+
+        public void clearGenerationTrackerForTest() {
+            synchronized (NameValueCache.this) {
+                if (mGenerationTracker != null) {
+                    mGenerationTracker.destroy();
+                }
+                mValues.clear();
+                mGenerationTracker = null;
+            }
+        }
     }
 
     /**
@@ -2182,6 +2198,12 @@ public final class Settings {
             outKeySet.addAll(MOVED_TO_GLOBAL);
         }
 
+        /** @hide */
+        public static void clearProviderForTest() {
+            sProviderHolder.clearProviderForTest();
+            sNameValueCache.clearGenerationTrackerForTest();
+        }
+
         /**
          * Look up a name in the database.
          * @param resolver to access the database with
@@ -4595,6 +4617,12 @@ public final class Settings {
             outKeySet.addAll(MOVED_TO_GLOBAL);
         }
 
+        /** @hide */
+        public static void clearProviderForTest() {
+            sProviderHolder.clearProviderForTest();
+            sNameValueCache.clearGenerationTrackerForTest();
+        }
+
         /**
          * Look up a name in the database.
          * @param resolver to access the database with
@@ -10027,6 +10055,12 @@ public final class Settings {
             outKeySet.addAll(MOVED_TO_SECURE);
         }
 
+        /** @hide */
+        public static void clearProviderForTest() {
+            sProviderHolder.clearProviderForTest();
+            sNameValueCache.clearGenerationTrackerForTest();
+        }
+
         /**
          * Look up a name in the database.
          * @param resolver to access the database with

services/tests/servicestests/src/com/android/server/am/CoreSettingsObserverTest.java

@@ -34,6 +34,7 @@ import android.test.mock.MockContentResolver;
 import com.android.internal.util.test.FakeSettingsProvider;
 import com.android.server.AppOpsService;
 
+import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Ignore;
@@ -59,7 +60,6 @@ import java.io.File;
  * Run: adb shell am instrument -e class com.android.server.am.CoreSettingsObserverTest -w \
  *     com.android.frameworks.servicestests/android.support.test.runner.AndroidJUnitRunner
  */
-@Ignore
 @SmallTest
 @RunWith(AndroidJUnit4.class)
 public class CoreSettingsObserverTest {
@@ -79,11 +79,17 @@ public class CoreSettingsObserverTest {
 
     @BeforeClass
     public static void setupOnce() {
+        FakeSettingsProvider.clearSettingsProvider();
         CoreSettingsObserver.sSecureSettingToTypeMap.put(TEST_SETTING_SECURE_INT, int.class);
         CoreSettingsObserver.sGlobalSettingToTypeMap.put(TEST_SETTING_GLOBAL_FLOAT, float.class);
         CoreSettingsObserver.sSystemSettingToTypeMap.put(TEST_SETTING_SYSTEM_STRING, String.class);
     }
 
+    @AfterClass
+    public static void tearDownOnce() {
+        FakeSettingsProvider.clearSettingsProvider();
+    }
+
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);

tests/utils/testutils/java/com/android/internal/util/test/FakeSettingsProvider.java

@@ -54,7 +54,8 @@ import java.util.HashMap;
  * Note that this class cannot be used in the same process as real settings. This is because it
  * works by passing an alternate ContentResolver to Settings operations. Unfortunately, the Settings
  * class only fetches the content provider from the passed-in ContentResolver the first time it's
- * used, and after that stores it in a per-process static.
+ * used, and after that stores it in a per-process static. If this needs to be used in this case,
+ * then call {@link #clearSettingsProvider()} before and after using this.
  *
  * TODO: evaluate implementing settings change notifications. This would require:
  *
@@ -90,6 +91,15 @@ public class FakeSettingsProvider extends MockContentProvider {
         }
     }
 
+    /**
+     * This needs to be called before and after using the FakeSettingsProvider class.
+     */
+    public static void clearSettingsProvider() {
+        Settings.Secure.clearProviderForTest();
+        Settings.Global.clearProviderForTest();
+        Settings.System.clearProviderForTest();
+    }
+
     public Bundle call(String method, String arg, Bundle extras) {
         // Methods are "GET_system", "GET_global", "PUT_secure", etc.
         String[] commands = method.split("_", 2);