Merge "Save brightness into persistent data store using a handler" into tm-dev

services/core/java/com/android/server/display/PersistentDataStore.java

@@ -20,6 +20,7 @@ import android.annotation.Nullable;
 import android.graphics.Point;
 import android.hardware.display.BrightnessConfiguration;
 import android.hardware.display.WifiDisplay;
+import android.os.Handler;
 import android.util.AtomicFile;
 import android.util.Slog;
 import android.util.SparseArray;
@@ -31,12 +32,14 @@ import android.util.Xml;
 import android.view.Display;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.os.BackgroundThread;
 import com.android.internal.util.XmlUtils;
 
 import libcore.io.IoUtils;
 
 import org.xmlpull.v1.XmlPullParserException;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
@@ -141,13 +144,22 @@ final class PersistentDataStore {
     // The interface for methods which should be replaced by the test harness.
     private Injector mInjector;
 
+    private final Handler mHandler;
+    private final Object mFileAccessLock = new Object();
+
     public PersistentDataStore() {
         this(new Injector());
     }
 
     @VisibleForTesting
     PersistentDataStore(Injector injector) {
+        this(injector, BackgroundThread.getHandler());
+    }
+
+    @VisibleForTesting
+    PersistentDataStore(Injector injector, Handler handler) {
         mInjector = injector;
+        mHandler = handler;
     }
 
     public void saveIfNeeded() {
@@ -418,6 +430,7 @@ final class PersistentDataStore {
     }
 
     private void load() {
+        synchronized (mFileAccessLock) {
             clearState();
 
             final InputStream is;
@@ -441,22 +454,36 @@ final class PersistentDataStore {
                 IoUtils.closeQuietly(is);
             }
         }
+    }
 
     private void save() {
-        final OutputStream os;
+        final ByteArrayOutputStream os;
-        try {
-            os = mInjector.startWrite();
-            boolean success = false;
         try {
+            os = new ByteArrayOutputStream();
+
             TypedXmlSerializer serializer = Xml.resolveSerializer(os);
             saveToXml(serializer);
             serializer.flush();
-                success = true;
+
-            } finally {
+            mHandler.removeCallbacksAndMessages(/* token */ null);
-                mInjector.finishWrite(os, success);
+            mHandler.post(() -> {
-            }
+                synchronized (mFileAccessLock) {
+                    OutputStream fileOutput = null;
+                    try {
+                        fileOutput = mInjector.startWrite();
+                        os.writeTo(fileOutput);
+                        fileOutput.flush();
                     } catch (IOException ex) {
                         Slog.w(TAG, "Failed to save display manager persistent store data.", ex);
+                    } finally {
+                        if (fileOutput != null) {
+                            mInjector.finishWrite(fileOutput, true);
+                        }
+                    }
+                }
+            });
+        } catch (IOException ex) {
+            Slog.w(TAG, "Failed to process the XML serializer.", ex);
         }
     }
 

services/tests/servicestests/src/com/android/server/display/PersistentDataStoreTest.java

@@ -24,6 +24,8 @@ import static org.junit.Assert.assertTrue;
 
 import android.content.Context;
 import android.hardware.display.BrightnessConfiguration;
+import android.os.Handler;
+import android.os.test.TestLooper;
 import android.util.Pair;
 
 import androidx.test.InstrumentationRegistry;
@@ -47,11 +49,14 @@ import java.nio.charset.StandardCharsets;
 public class PersistentDataStoreTest {
     private PersistentDataStore mDataStore;
     private TestInjector mInjector;
+    private TestLooper mTestLooper;
 
     @Before
     public void setUp() {
         mInjector = new TestInjector();
-        mDataStore = new PersistentDataStore(mInjector);
+        mTestLooper = new TestLooper();
+        Handler handler = new Handler(mTestLooper.getLooper());
+        mDataStore = new PersistentDataStore(mInjector, handler);
     }
 
     @Test
@@ -147,7 +152,7 @@ public class PersistentDataStoreTest {
     }
 
     @Test
-    public void testStoreAndReloadOfDisplayBrightnessConfigurations() {
+    public void testStoreAndReloadOfDisplayBrightnessConfigurations() throws InterruptedException {
         final String uniqueDisplayId = "test:123";
         int userSerial = 0;
         String packageName = "pdsTestPackage";
@@ -178,6 +183,7 @@ public class PersistentDataStoreTest {
         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
         mInjector.setWriteStream(baos);
         mDataStore.saveIfNeeded();
+        mTestLooper.dispatchAll();
         assertTrue(mInjector.wasWriteSuccessful());
         TestInjector newInjector = new TestInjector();
         PersistentDataStore newDataStore = new PersistentDataStore(newInjector);
@@ -222,7 +228,7 @@ public class PersistentDataStoreTest {
     }
 
     @Test
-    public void testStoreAndReloadOfBrightnessConfigurations() {
+    public void testStoreAndReloadOfBrightnessConfigurations() throws InterruptedException {
         final float[] lux = { 0f, 10f };
         final float[] nits = {1f, 100f };
         final BrightnessConfiguration config = new BrightnessConfiguration.Builder(lux, nits)
@@ -238,6 +244,7 @@ public class PersistentDataStoreTest {
         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
         mInjector.setWriteStream(baos);
         mDataStore.saveIfNeeded();
+        mTestLooper.dispatchAll();
         assertTrue(mInjector.wasWriteSuccessful());
 
         TestInjector newInjector = new TestInjector();