am 18414c4d: Merge "Provide SharedPreferences coherence guarantees for BackupAgent" into jb-mr2-dev (353bd75b) · Commits · e / os / android_frameworks_base

core/java/android/app/backup/BackupAgent.java

+48 −0

Original line number	Original line	Diff line number	Diff line
	@@ -17,12 +17,15 @@
	package android.app.backup;		package android.app.backup;

	import android.app.IBackupAgent;		import android.app.IBackupAgent;
			import android.app.QueuedWork;
	import android.app.backup.IBackupManager;		import android.app.backup.IBackupManager;
	import android.content.Context;		import android.content.Context;
	import android.content.ContextWrapper;		import android.content.ContextWrapper;
	import android.content.pm.ApplicationInfo;		import android.content.pm.ApplicationInfo;
	import android.os.Binder;		import android.os.Binder;
			import android.os.Handler;
	import android.os.IBinder;		import android.os.IBinder;
			import android.os.Looper;
	import android.os.ParcelFileDescriptor;		import android.os.ParcelFileDescriptor;
	import android.os.Process;		import android.os.Process;
	import android.os.RemoteException;		import android.os.RemoteException;
	@@ -33,6 +36,7 @@ import java.io.FileOutputStream;
	import java.io.IOException;		import java.io.IOException;
	import java.util.HashSet;		import java.util.HashSet;
	import java.util.LinkedList;		import java.util.LinkedList;
			import java.util.concurrent.CountDownLatch;

	import libcore.io.ErrnoException;		import libcore.io.ErrnoException;
	import libcore.io.Libcore;		import libcore.io.Libcore;
	@@ -122,6 +126,32 @@ public abstract class BackupAgent extends ContextWrapper {
	/** @hide */		/** @hide */
	public static final int TYPE_SYMLINK = 3;		public static final int TYPE_SYMLINK = 3;

			Handler mHandler = null;

			class SharedPrefsSynchronizer implements Runnable {
			public final CountDownLatch mLatch = new CountDownLatch(1);

			@Override
			public void run() {
			QueuedWork.waitToFinish();
			mLatch.countDown();
			}
			};

			// Syncing shared preferences deferred writes needs to happen on the main looper thread
			private void waitForSharedPrefs() {
			if (mHandler == null) {
			mHandler = new Handler(Looper.getMainLooper());
			}

			final SharedPrefsSynchronizer s = new SharedPrefsSynchronizer();
			mHandler.postAtFrontOfQueue(s);
			try {
			s.mLatch.await();
			} catch (InterruptedException e) { /* ignored */ }
			}


	public BackupAgent() {		public BackupAgent() {
	super(null);		super(null);
	}		}
	@@ -542,6 +572,11 @@ public abstract class BackupAgent extends ContextWrapper {
	Log.d(TAG, "onBackup (" + BackupAgent.this.getClass().getName() + ") threw", ex);		Log.d(TAG, "onBackup (" + BackupAgent.this.getClass().getName() + ") threw", ex);
	throw ex;		throw ex;
	} finally {		} finally {
			// Ensure that any SharedPreferences writes have landed after the backup,
			// in case the app code has side effects (since apps cannot provide this
			// guarantee themselves).
			waitForSharedPrefs();

	Binder.restoreCallingIdentity(ident);		Binder.restoreCallingIdentity(ident);
	try {		try {
	callbackBinder.opComplete(token);		callbackBinder.opComplete(token);
	@@ -569,6 +604,9 @@ public abstract class BackupAgent extends ContextWrapper {
	Log.d(TAG, "onRestore (" + BackupAgent.this.getClass().getName() + ") threw", ex);		Log.d(TAG, "onRestore (" + BackupAgent.this.getClass().getName() + ") threw", ex);
	throw ex;		throw ex;
	} finally {		} finally {
			// Ensure that any side-effect SharedPreferences writes have landed
			waitForSharedPrefs();

	Binder.restoreCallingIdentity(ident);		Binder.restoreCallingIdentity(ident);
	try {		try {
	callbackBinder.opComplete(token);		callbackBinder.opComplete(token);
	@@ -586,6 +624,10 @@ public abstract class BackupAgent extends ContextWrapper {

	if (DEBUG) Log.v(TAG, "doFullBackup() invoked");		if (DEBUG) Log.v(TAG, "doFullBackup() invoked");

			// Ensure that any SharedPreferences writes have landed before
			// we potentially try to back up the underlying files directly.
			waitForSharedPrefs();

	try {		try {
	BackupAgent.this.onFullBackup(new FullBackupDataOutput(data));		BackupAgent.this.onFullBackup(new FullBackupDataOutput(data));
	} catch (IOException ex) {		} catch (IOException ex) {
	@@ -595,6 +637,9 @@ public abstract class BackupAgent extends ContextWrapper {
	Log.d(TAG, "onBackup (" + BackupAgent.this.getClass().getName() + ") threw", ex);		Log.d(TAG, "onBackup (" + BackupAgent.this.getClass().getName() + ") threw", ex);
	throw ex;		throw ex;
	} finally {		} finally {
			// ... and then again after, as in the doBackup() case
			waitForSharedPrefs();

	// Send the EOD marker indicating that there is no more data		// Send the EOD marker indicating that there is no more data
	// forthcoming from this agent.		// forthcoming from this agent.
	try {		try {
	@@ -624,6 +669,9 @@ public abstract class BackupAgent extends ContextWrapper {
	} catch (IOException e) {		} catch (IOException e) {
	throw new RuntimeException(e);		throw new RuntimeException(e);
	} finally {		} finally {
			// Ensure that any side-effect SharedPreferences writes have landed
			waitForSharedPrefs();

	Binder.restoreCallingIdentity(ident);		Binder.restoreCallingIdentity(ident);
	try {		try {
	callbackBinder.opComplete(token);		callbackBinder.opComplete(token);