Make the RegisteredSErvices Cache not allow the registered service for a

type to change without first uninstalling the previous service for that
type, unless the newly installed service is in the system image.

Notify the listener when a service is added or removed.

Make the AccountManagerService remove the accounts for an authenticator
when the registered authenticator changes from one uid to another.

Make the AbstractSyncableContentProvider force a sync when the database is first created.

core/java/android/accounts/AccountAuthenticatorCache.java

@@ -18,10 +18,16 @@ package android.accounts;
 
 import android.content.pm.PackageManager;
 import android.content.pm.RegisteredServicesCache;
+import android.content.pm.XmlSerializerAndParser;
 import android.content.res.TypedArray;
 import android.content.Context;
 import android.util.AttributeSet;
 import android.text.TextUtils;
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlSerializer;
+import org.xmlpull.v1.XmlPullParserException;
+
+import java.io.IOException;
 
 /**
  * A cache of services that export the {@link IAccountAuthenticator} interface. This cache
@@ -33,10 +39,12 @@ import android.text.TextUtils;
 /* package private */ class AccountAuthenticatorCache
         extends RegisteredServicesCache<AuthenticatorDescription> {
     private static final String TAG = "Account";
+    private static final MySerializer sSerializer = new MySerializer();
 
     public AccountAuthenticatorCache(Context context) {
         super(context, AccountManager.ACTION_AUTHENTICATOR_INTENT,
-                AccountManager.AUTHENTICATOR_META_DATA_NAME, AccountManager.AUTHENTICATOR_ATTRIBUTES_NAME);
+                AccountManager.AUTHENTICATOR_META_DATA_NAME,
+                AccountManager.AUTHENTICATOR_ATTRIBUTES_NAME, sSerializer);
     }
 
     public AuthenticatorDescription parseServiceAttributes(String packageName, AttributeSet attrs) {
@@ -62,4 +70,16 @@ import android.text.TextUtils;
             sa.recycle();
         }
     }
+
+    private static class MySerializer implements XmlSerializerAndParser<AuthenticatorDescription> {
+        public void writeAsXml(AuthenticatorDescription item, XmlSerializer out)
+                throws IOException {
+            out.attribute(null, "type", item.type);
+        }
+
+        public AuthenticatorDescription createFromXml(XmlPullParser parser)
+                throws IOException, XmlPullParserException {
+            return AuthenticatorDescription.newKey(parser.getAttributeValue(null, "type"));
+        }
+    }
 }

core/java/android/accounts/AccountManagerService.java

@@ -72,7 +72,7 @@ import com.android.internal.R;
  */
 public class AccountManagerService
         extends IAccountManager.Stub
-        implements RegisteredServicesCacheListener {
+        implements RegisteredServicesCacheListener<AuthenticatorDescription> {
     private static final String GOOGLE_ACCOUNT_TYPE = "com.google";
 
     private static final String NO_BROADCAST_FLAG = "nobroadcast";
@@ -220,34 +220,29 @@ public class AccountManagerService
         mMessageHandler = new MessageHandler(mMessageThread.getLooper());
 
         mAuthenticatorCache = new AccountAuthenticatorCache(mContext);
-        mAuthenticatorCache.setListener(this);
+        mAuthenticatorCache.setListener(this, null /* Handler */);
         mBindHelper = new AuthenticatorBindHelper(mContext, mAuthenticatorCache, mMessageHandler,
                 MESSAGE_CONNECTED, MESSAGE_DISCONNECTED);
 
         mSimWatcher = new SimWatcher(mContext);
         sThis.set(this);
-
-        onRegisteredServicesCacheChanged();
     }
 
-    public void onRegisteredServicesCacheChanged() {
+    public void onServiceChanged(AuthenticatorDescription desc, boolean removed) {
         boolean accountDeleted = false;
         SQLiteDatabase db = mOpenHelper.getWritableDatabase();
         Cursor cursor = db.query(TABLE_ACCOUNTS,
                 new String[]{ACCOUNTS_ID, ACCOUNTS_TYPE, ACCOUNTS_NAME},
-                null, null, null, null, null);
+                ACCOUNTS_TYPE + "=?", new String[]{desc.type}, null, null, null);
         try {
             while (cursor.moveToNext()) {
                 final long accountId = cursor.getLong(0);
                 final String accountType = cursor.getString(1);
                 final String accountName = cursor.getString(2);
-                if (mAuthenticatorCache.getServiceInfo(AuthenticatorDescription.newKey(accountType))
-                        == null) {
-                    Log.d(TAG, "deleting account " + accountName + " because type "
-                            + accountType + " no longer has a registered authenticator");
-                    db.delete(TABLE_ACCOUNTS, ACCOUNTS_ID + "=" + accountId, null);
-                    accountDeleted= true;
-                }
+                Log.d(TAG, "deleting account " + accountName + " because type "
+                        + accountType + " no longer has a registered authenticator");
+                db.delete(TABLE_ACCOUNTS, ACCOUNTS_ID + "=" + accountId, null);
+                accountDeleted = true;
             }
         } finally {
             cursor.close();

core/java/android/accounts/AuthenticatorDescription.java

@@ -87,6 +87,10 @@ public class AuthenticatorDescription implements Parcelable {
         return type.equals(other.type);
     }
 
+    public String toString() {
+        return "AuthenticatorDescription {type=" + type + "}";
+    }
+
     /** @inhericDoc */
     public void writeToParcel(Parcel dest, int flags) {
         dest.writeString(type);

core/java/android/content/AbstractSyncableContentProvider.java

@@ -135,6 +135,8 @@ public abstract class AbstractSyncableContentProvider extends SyncableContentPro
         public void onCreate(SQLiteDatabase db) {
             bootstrapDatabase(db);
             mSyncState.createDatabase(db);
+            ContentResolver.requestSync(null /* all accounts */,
+                    mContentUri.getAuthority(), new Bundle());
         }
 
         @Override

core/java/android/content/SyncAdaptersCache.java

@@ -17,9 +17,14 @@
 package android.content;
 
 import android.content.pm.RegisteredServicesCache;
+import android.content.pm.XmlSerializerAndParser;
 import android.content.res.TypedArray;
-import android.content.Context;
 import android.util.AttributeSet;
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlSerializer;
+import org.xmlpull.v1.XmlPullParserException;
+
+import java.io.IOException;
 
 /**
  * A cache of services that export the {@link android.content.ISyncAdapter} interface.
@@ -31,9 +36,10 @@ import android.util.AttributeSet;
     private static final String SERVICE_INTERFACE = "android.content.SyncAdapter";
     private static final String SERVICE_META_DATA = "android.content.SyncAdapter";
     private static final String ATTRIBUTES_NAME = "sync-adapter";
+    private static final MySerializer sSerializer = new MySerializer();
 
     SyncAdaptersCache(Context context) {
-        super(context, SERVICE_INTERFACE, SERVICE_META_DATA, ATTRIBUTES_NAME);
+        super(context, SERVICE_INTERFACE, SERVICE_META_DATA, ATTRIBUTES_NAME, sSerializer);
     }
 
     public SyncAdapterType parseServiceAttributes(String packageName, AttributeSet attrs) {
@@ -57,4 +63,18 @@ import android.util.AttributeSet;
             sa.recycle();
         }
     }
+
+    static class MySerializer implements XmlSerializerAndParser<SyncAdapterType> {
+        public void writeAsXml(SyncAdapterType item, XmlSerializer out) throws IOException {
+            out.attribute(null, "authority", item.authority);
+            out.attribute(null, "accountType", item.accountType);
+        }
+    
+        public SyncAdapterType createFromXml(XmlPullParser parser)
+                throws IOException, XmlPullParserException {
+            final String authority = parser.getAttributeValue(null, "authority");
+            final String accountType = parser.getAttributeValue(null, "accountType");
+            return SyncAdapterType.newKey(authority, accountType);
+        }
+    }
 }

core/java/android/content/pm/RegisteredServicesCache.java

@@ -22,6 +22,8 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.ComponentName;
 import android.content.res.XmlResourceParser;
+import android.os.Environment;
+import android.os.Handler;
 import android.util.Log;
 import android.util.AttributeSet;
 import android.util.Xml;
@@ -29,14 +31,26 @@ import android.util.Xml;
 import java.util.Map;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.ArrayList;
+import java.util.concurrent.atomic.AtomicReference;
+import java.io.File;
+import java.io.FileOutputStream;
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.io.IOException;
+import java.io.FileInputStream;
+
+import com.android.internal.os.AtomicFile;
+import com.android.internal.util.FastXmlSerializer;
 
 import com.google.android.collect.Maps;
+import com.google.android.collect.Lists;
+
 import org.xmlpull.v1.XmlPullParserException;
 import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlSerializer;
 
 /**
  * A cache of registered services. This cache
@@ -52,75 +66,104 @@ public abstract class RegisteredServicesCache<V> {
     private final String mInterfaceName;
     private final String mMetaDataName;
     private final String mAttributesName;
+    private final XmlSerializerAndParser<V> mSerializerAndParser;
+    private final AtomicReference<BroadcastReceiver> mReceiver;
 
-    public RegisteredServicesCacheListener getListener() {
-        return mListener;
-    }
+    private final Object mServicesLock = new Object();
+    // synchronized on mServicesLock
+    private HashMap<V, Integer> mPersistentServices;
+    // synchronized on mServicesLock
+    private Map<V, ServiceInfo<V>> mServices;
+    // synchronized on mServicesLock
+    private boolean mPersistentServicesFileDidNotExist;
 
-    public void setListener(RegisteredServicesCacheListener listener) {
-        mListener = listener;
-    }
+    /**
+     * This file contains the list of known services. We would like to maintain this forever
+     * so we store it as an XML file.
+     */
+    private final AtomicFile mPersistentServicesFile;
 
-    private volatile RegisteredServicesCacheListener mListener;
-
-    // no need to be synchronized since the map is never changed once mService is written
-    volatile Map<V, ServiceInfo<V>> mServices;
-
-    // synchronized on "this"
-    private BroadcastReceiver mReceiver = null;
+    // the listener and handler are synchronized on "this" and must be updated together
+    private RegisteredServicesCacheListener<V> mListener;
+    private Handler mHandler;
 
     public RegisteredServicesCache(Context context, String interfaceName, String metaDataName,
-            String attributeName) {
+            String attributeName, XmlSerializerAndParser<V> serializerAndParser) {
         mContext = context;
         mInterfaceName = interfaceName;
         mMetaDataName = metaDataName;
         mAttributesName = attributeName;
+        mSerializerAndParser = serializerAndParser;
+
+        File dataDir = Environment.getDataDirectory();
+        File systemDir = new File(dataDir, "system");
+        File syncDir = new File(systemDir, "registered_services");
+        mPersistentServicesFile = new AtomicFile(new File(syncDir, interfaceName + ".xml"));
+
+        generateServicesMap();
+
+        final BroadcastReceiver receiver = new BroadcastReceiver() {
+            @Override
+            public void onReceive(Context context1, Intent intent) {
+                generateServicesMap();
+            }
+        };
+        mReceiver = new AtomicReference<BroadcastReceiver>(receiver);
+        IntentFilter intentFilter = new IntentFilter();
+        intentFilter.addAction(Intent.ACTION_PACKAGE_ADDED);
+        intentFilter.addAction(Intent.ACTION_PACKAGE_CHANGED);
+        intentFilter.addAction(Intent.ACTION_PACKAGE_REMOVED);
+        intentFilter.addDataScheme("package");
+        mContext.registerReceiver(receiver, intentFilter);
     }
 
     public void dump(FileDescriptor fd, PrintWriter fout, String[] args) {
-        getAllServices();
-        Map<V, ServiceInfo<V>> services = mServices;
+        Map<V, ServiceInfo<V>> services;
+        synchronized (mServicesLock) {
+            services = mServices;
+        }
         fout.println("RegisteredServicesCache: " + services.size() + " services");
         for (ServiceInfo info : services.values()) {
             fout.println("  " + info);
         }
     }
 
-    private boolean maybeRegisterForPackageChanges() {
+    public RegisteredServicesCacheListener<V> getListener() {
         synchronized (this) {
-            if (mReceiver == null) {
-                synchronized (this) {
-                    mReceiver = new BroadcastReceiver() {
-                        @Override
-                        public void onReceive(Context context, Intent intent) {
-                            mServices = generateServicesMap();
-                            RegisteredServicesCacheListener listener = mListener;
-                            if (listener != null) {
-                                listener.onRegisteredServicesCacheChanged();
-                            }
-                        }
-                    };
-                }
-
-                IntentFilter intentFilter = new IntentFilter();
-                intentFilter.addAction(Intent.ACTION_PACKAGE_ADDED);
-                intentFilter.addAction(Intent.ACTION_PACKAGE_CHANGED);
-                intentFilter.addAction(Intent.ACTION_PACKAGE_REMOVED);
-                intentFilter.addDataScheme("package");
-                mContext.registerReceiver(mReceiver, intentFilter);
-                return true;
-            }
-            return false;
+            return mListener;
         }
     }
 
-    private void maybeUnregisterForPackageChanges() {
-        synchronized (this) {
-            if (mReceiver != null) {
-                mContext.unregisterReceiver(mReceiver);
-                mReceiver = null;
-            }
+    public void setListener(RegisteredServicesCacheListener<V> listener, Handler handler) {
+        if (handler == null) {
+            handler = new Handler(mContext.getMainLooper());
         }
+        synchronized (this) {
+            mHandler = handler;
+            mListener = listener;
+        }
+    }
+
+    private void notifyListener(final V type, final boolean removed) {
+        if (Log.isLoggable(TAG, Log.VERBOSE)) {
+            Log.d(TAG, "notifyListener: " + type + " is " + (removed ? "removed" : "added"));
+        }
+        RegisteredServicesCacheListener<V> listener;
+        Handler handler; 
+        synchronized (this) {
+            listener = mListener;
+            handler = mHandler;
+        }
+        if (listener == null) {
+            return;
+        }
+        
+        final RegisteredServicesCacheListener<V> listener2 = listener;
+        handler.post(new Runnable() {
+            public void run() {
+                listener2.onServiceChanged(type, removed);
+            }
+        });
     }
 
     /**
@@ -140,7 +183,7 @@ public abstract class RegisteredServicesCache<V> {
 
         @Override
         public String toString() {
-            return "ServiceInfo: " + type + ", " + componentName;
+            return "ServiceInfo: " + type + ", " + componentName + ", uid " + uid;
         }
     }
 
@@ -150,11 +193,9 @@ public abstract class RegisteredServicesCache<V> {
      * @return the AuthenticatorInfo that matches the account type or null if none is present
      */
     public ServiceInfo<V> getServiceInfo(V type) {
-        if (mServices == null) {
-            maybeRegisterForPackageChanges();
-            mServices = generateServicesMap();
+        synchronized (mServicesLock) {
+            return mServices.get(type);
         }
-        return mServices.get(type);
     }
 
     /**
@@ -162,54 +203,171 @@ public abstract class RegisteredServicesCache<V> {
      * registered authenticators.
      */
     public Collection<ServiceInfo<V>> getAllServices() {
-        if (mServices == null) {
-            maybeRegisterForPackageChanges();
-            mServices = generateServicesMap();
+        synchronized (mServicesLock) {
+            return Collections.unmodifiableCollection(mServices.values());
         }
-        return Collections.unmodifiableCollection(mServices.values());
     }
 
     /**
      * Stops the monitoring of package additions, removals and changes.
      */
     public void close() {
-        maybeUnregisterForPackageChanges();
+        final BroadcastReceiver receiver = mReceiver.getAndSet(null);
+        if (receiver != null) {
+            mContext.unregisterReceiver(receiver);
+        }
     }
 
     @Override
     protected void finalize() throws Throwable {
-        synchronized (this) {
-            if (mReceiver != null) {
-                Log.e(TAG, "RegisteredServicesCache finalized without being closed");
-            }
+        if (mReceiver.get() != null) {
+            Log.e(TAG, "RegisteredServicesCache finalized without being closed");
         }
         close();
         super.finalize();
     }
 
-    Map<V, ServiceInfo<V>> generateServicesMap() {
-        Map<V, ServiceInfo<V>> services = Maps.newHashMap();
+    private boolean inSystemImage(int callerUid) {
+        String[] packages = mContext.getPackageManager().getPackagesForUid(callerUid);
+        for (String name : packages) {
+            try {
+                PackageInfo packageInfo =
+                        mContext.getPackageManager().getPackageInfo(name, 0 /* flags */);
+                if ((packageInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0) {
+                    return true;
+                }
+            } catch (PackageManager.NameNotFoundException e) {
+                return false;
+            }
+        }
+        return false;
+    }
+
+    void generateServicesMap() {
         PackageManager pm = mContext.getPackageManager();
-
-        List<ResolveInfo> resolveInfos =
-                pm.queryIntentServices(new Intent(mInterfaceName), PackageManager.GET_META_DATA);
-
+        ArrayList<ServiceInfo<V>> serviceInfos = new ArrayList<ServiceInfo<V>>();
+        List<ResolveInfo> resolveInfos = pm.queryIntentServices(new Intent(mInterfaceName),
+                PackageManager.GET_META_DATA);
         for (ResolveInfo resolveInfo : resolveInfos) {
             try {
                 ServiceInfo<V> info = parseServiceInfo(resolveInfo);
-                if (info != null) {
-                    services.put(info.type, info);
-                } else {
-                    Log.w(TAG, "Unable to load input method " + resolveInfo.toString());
+                if (info == null) {
+                    Log.w(TAG, "Unable to load service info " + resolveInfo.toString());
+                    continue;
                 }
+                serviceInfos.add(info);
             } catch (XmlPullParserException e) {
-                Log.w(TAG, "Unable to load input method " + resolveInfo.toString(), e);
+                Log.w(TAG, "Unable to load service info " + resolveInfo.toString(), e);
             } catch (IOException e) {
-                Log.w(TAG, "Unable to load input method " + resolveInfo.toString(), e);
+                Log.w(TAG, "Unable to load service info " + resolveInfo.toString(), e);
             }
         }
 
-        return services;
+        synchronized (mServicesLock) {
+            if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                Log.d(TAG, "generateServicesMap: " + mInterfaceName);
+            }
+            if (mPersistentServices == null) {
+                readPersistentServicesLocked();
+            }
+            mServices = Maps.newHashMap();
+            boolean changed = false;
+            if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                Log.d(TAG, "found " + serviceInfos.size() + " services");
+            }
+            for (ServiceInfo<V> info : serviceInfos) {
+                // four cases:
+                // - doesn't exist yet
+                //   - add, notify user that it was added
+                // - exists and the UID is the same
+                //   - replace, don't notify user
+                // - exists, the UID is different, and the new one is not a system package
+                //   - ignore
+                // - exists, the UID is different, and the new one is a system package
+                //   - add, notify user that it was added
+                Integer previousUid = mPersistentServices.get(info.type);
+                if (previousUid == null) {
+                    if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                        Log.d(TAG, "encountered new type: " + info);
+                    }
+                    changed = true;
+                    mServices.put(info.type, info);
+                    mPersistentServices.put(info.type, info.uid);
+                    if (!mPersistentServicesFileDidNotExist) {
+                        notifyListener(info.type, false /* removed */);
+                    }
+                } else if (previousUid == info.uid) {
+                    if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                        Log.d(TAG, "encountered existing type with the same uid: " + info);
+                    }
+                    mServices.put(info.type, info);
+                } else if (inSystemImage(info.uid)
+                        || !containsTypeAndUid(serviceInfos, info.type, previousUid)) {
+                    if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                        if (inSystemImage(info.uid)) {
+                            Log.d(TAG, "encountered existing type with a new uid but from"
+                                    + " the system: " + info);
+                        } else {
+                            Log.d(TAG, "encountered existing type with a new uid but existing was"
+                                    + " removed: " + info);
+                        }
+                    }
+                    changed = true;
+                    mServices.put(info.type, info);
+                    mPersistentServices.put(info.type, info.uid);
+                    notifyListener(info.type, false /* removed */);
+                } else {
+                    // ignore
+                    if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                        Log.d(TAG, "encountered existing type with a new uid, ignoring: " + info);
+                    }
+                }
+            }
+
+            ArrayList<V> toBeRemoved = Lists.newArrayList();
+            for (V v1 : mPersistentServices.keySet()) {
+                if (!containsType(serviceInfos, v1)) {
+                    toBeRemoved.add(v1);
+                }
+            }
+            for (V v1 : toBeRemoved) {
+                mPersistentServices.remove(v1);
+                changed = true;
+                notifyListener(v1, true /* removed */);
+            }
+            if (changed) {
+                if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                    Log.d(TAG, "writing updated list of persistent services");
+                }
+                writePersistentServicesLocked();
+            } else {
+                if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                    Log.d(TAG, "persistent services did not change, so not writing anything");
+                }
+            }
+            mPersistentServicesFileDidNotExist = false;
+        }
+    }
+
+    private boolean containsType(ArrayList<ServiceInfo<V>> serviceInfos, V type) {
+        for (int i = 0, N = serviceInfos.size(); i < N; i++) {
+            if (serviceInfos.get(i).type.equals(type)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private boolean containsTypeAndUid(ArrayList<ServiceInfo<V>> serviceInfos, V type, int uid) {
+        for (int i = 0, N = serviceInfos.size(); i < N; i++) {
+            final ServiceInfo<V> serviceInfo = serviceInfos.get(i);
+            if (serviceInfo.type.equals(type) && serviceInfo.uid == uid) {
+                return true;
+            }
+        }
+
+        return false;
     }
 
     private ServiceInfo<V> parseServiceInfo(ResolveInfo service)
@@ -252,5 +410,89 @@ public abstract class RegisteredServicesCache<V> {
         }
     }
 
+    /**
+     * Read all sync status back in to the initial engine state.
+     */
+    private void readPersistentServicesLocked() {
+        mPersistentServices = Maps.newHashMap();
+        if (mSerializerAndParser == null) {
+            return;
+        }
+        FileInputStream fis = null;
+        try {
+            mPersistentServicesFileDidNotExist = !mPersistentServicesFile.getBaseFile().exists();
+            if (mPersistentServicesFileDidNotExist) {
+                return;
+            }
+            fis = mPersistentServicesFile.openRead();
+            XmlPullParser parser = Xml.newPullParser();
+            parser.setInput(fis, null);
+            int eventType = parser.getEventType();
+            while (eventType != XmlPullParser.START_TAG) {
+                eventType = parser.next();
+            }
+            String tagName = parser.getName();
+            if ("services".equals(tagName)) {
+                eventType = parser.next();
+                do {
+                    if (eventType == XmlPullParser.START_TAG && parser.getDepth() == 2) {
+                        tagName = parser.getName();
+                        if ("service".equals(tagName)) {
+                            V service = mSerializerAndParser.createFromXml(parser);
+                            if (service == null) {
+                                break;
+                            }
+                            String uidString = parser.getAttributeValue(null, "uid");
+                            int uid = Integer.parseInt(uidString);
+                            mPersistentServices.put(service, uid);
+                        }
+                    }
+                    eventType = parser.next();
+                } while (eventType != XmlPullParser.END_DOCUMENT);
+            }
+        } catch (Exception e) {
+            Log.w(TAG, "Error reading persistent services, starting from scratch", e);
+        } finally {
+            if (fis != null) {
+                try {
+                    fis.close();
+                } catch (java.io.IOException e1) {
+                }
+            }
+        }
+    }
+
+    /**
+     * Write all sync status to the sync status file.
+     */
+    private void writePersistentServicesLocked() {
+        if (mSerializerAndParser == null) {
+            return;
+        }
+        FileOutputStream fos = null;
+        try {
+            fos = mPersistentServicesFile.startWrite();
+            XmlSerializer out = new FastXmlSerializer();
+            out.setOutput(fos, "utf-8");
+            out.startDocument(null, true);
+            out.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true);
+            out.startTag(null, "services");
+            for (Map.Entry<V, Integer> service : mPersistentServices.entrySet()) {
+                out.startTag(null, "service");
+                out.attribute(null, "uid", Integer.toString(service.getValue()));
+                mSerializerAndParser.writeAsXml(service.getKey(), out);
+                out.endTag(null, "service");
+            }
+            out.endTag(null, "services");
+            out.endDocument();
+            mPersistentServicesFile.finishWrite(fos);
+        } catch (java.io.IOException e1) {
+            Log.w(TAG, "Error writing accounts", e1);
+            if (fos != null) {
+                mPersistentServicesFile.failWrite(fos);
+            }
+        }
+    }
+
     public abstract V parseServiceAttributes(String packageName, AttributeSet attrs);
 }

core/java/android/content/pm/RegisteredServicesCacheListener.java

@@ -1,12 +1,16 @@
 package android.content.pm;
 
+import android.os.Parcelable;
+
 /**
  * Listener for changes to the set of registered services managed by a RegisteredServicesCache.
  * @hide
  */
-public interface RegisteredServicesCacheListener {
+public interface RegisteredServicesCacheListener<V> {
     /**
-     * Invoked when the registered services cache changes.
+     * Invoked when a service is registered or changed.
+     * @param type the type of registered service
+     * @param removed true if the service was removed
      */
-    void onRegisteredServicesCacheChanged();
+    void onServiceChanged(V type, boolean removed);
 }

core/java/android/content/pm/XmlSerializerAndParser.java

@@ -0,0 +1,14 @@
+package android.content.pm;
+
+import org.xmlpull.v1.XmlSerializer;
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
+import android.os.Parcel;
+
+import java.io.IOException;
+
+/** @hide */
+public interface XmlSerializerAndParser<T> {
+    void writeAsXml(T item, XmlSerializer out) throws IOException;
+    T createFromXml(XmlPullParser parser) throws IOException, XmlPullParserException;
+}