Merge "API to select backup transport"
diff --git a/Android.mk b/Android.mk
index 2539c3d..71b77d5 100644
--- a/Android.mk
+++ b/Android.mk
@@ -107,6 +107,7 @@
 	core/java/android/app/backup/IFullBackupRestoreObserver.aidl \
 	core/java/android/app/backup/IRestoreObserver.aidl \
 	core/java/android/app/backup/IRestoreSession.aidl \
+	core/java/android/app/backup/ISelectBackupTransportCallback.aidl \
 	core/java/android/app/usage/IStorageStatsManager.aidl \
 	core/java/android/app/usage/IUsageStatsManager.aidl \
 	core/java/android/bluetooth/IBluetooth.aidl \
diff --git a/api/system-current.txt b/api/system-current.txt
index b6b25f5..5cd33ba 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -6787,15 +6787,18 @@
     method public int requestBackup(java.lang.String[], android.app.backup.BackupObserver);
     method public int requestBackup(java.lang.String[], android.app.backup.BackupObserver, int);
     method public int requestRestore(android.app.backup.RestoreObserver);
-    method public java.lang.String selectBackupTransport(java.lang.String);
+    method public deprecated java.lang.String selectBackupTransport(java.lang.String);
+    method public void selectBackupTransport(android.content.ComponentName, android.app.backup.SelectBackupTransportCallback);
     method public void setAutoRestore(boolean);
     method public void setBackupEnabled(boolean);
     field public static final int ERROR_AGENT_FAILURE = -1003; // 0xfffffc15
     field public static final int ERROR_BACKUP_NOT_ALLOWED = -2001; // 0xfffff82f
     field public static final int ERROR_PACKAGE_NOT_FOUND = -2002; // 0xfffff82e
     field public static final int ERROR_TRANSPORT_ABORTED = -1000; // 0xfffffc18
+    field public static final int ERROR_TRANSPORT_INVALID = -2; // 0xfffffffe
     field public static final int ERROR_TRANSPORT_PACKAGE_REJECTED = -1002; // 0xfffffc16
     field public static final int ERROR_TRANSPORT_QUOTA_EXCEEDED = -1005; // 0xfffffc13
+    field public static final int ERROR_TRANSPORT_UNAVAILABLE = -1; // 0xffffffff
     field public static final int FLAG_NON_INCREMENTAL_BACKUP = 1; // 0x1
     field public static final java.lang.String PACKAGE_MANAGER_SENTINEL = "@pm@";
     field public static final int SUCCESS = 0; // 0x0
@@ -6910,6 +6913,12 @@
     field public long token;
   }
 
+  public abstract class SelectBackupTransportCallback {
+    ctor public SelectBackupTransportCallback();
+    method public void onFailure(int);
+    method public void onSuccess(java.lang.String);
+  }
+
   public class SharedPreferencesBackupHelper extends android.app.backup.FileBackupHelperBase implements android.app.backup.BackupHelper {
     ctor public SharedPreferencesBackupHelper(android.content.Context, java.lang.String...);
     method public void performBackup(android.os.ParcelFileDescriptor, android.app.backup.BackupDataOutput, android.os.ParcelFileDescriptor);
diff --git a/cmds/bmgr/src/com/android/commands/bmgr/Bmgr.java b/cmds/bmgr/src/com/android/commands/bmgr/Bmgr.java
index 780db5e..7e91391 100644
--- a/cmds/bmgr/src/com/android/commands/bmgr/Bmgr.java
+++ b/cmds/bmgr/src/com/android/commands/bmgr/Bmgr.java
@@ -18,20 +18,24 @@
 
 import android.app.backup.BackupManager;
 import android.app.backup.BackupProgress;
-import android.app.backup.RestoreSet;
 import android.app.backup.IBackupManager;
 import android.app.backup.IBackupObserver;
 import android.app.backup.IRestoreObserver;
 import android.app.backup.IRestoreSession;
+import android.app.backup.RestoreSet;
+import android.app.backup.ISelectBackupTransportCallback;
+import android.content.ComponentName;
 import android.content.pm.IPackageManager;
 import android.content.pm.PackageInfo;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.UserHandle;
+import android.util.Log;
 
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
+import java.util.concurrent.CountDownLatch;
 
 public final class Bmgr {
     IBackupManager mBmgr;
@@ -363,6 +367,11 @@
                 return;
             }
 
+            if ("-c".equals(which)) {
+                doTransportByComponent();
+                return;
+            }
+
             String old = mBmgr.selectBackupTransport(which);
             if (old == null) {
                 System.out.println("Unknown transport '" + which
@@ -370,12 +379,50 @@
             } else {
                 System.out.println("Selected transport " + which + " (formerly " + old + ")");
             }
+
         } catch (RemoteException e) {
             System.err.println(e.toString());
             System.err.println(BMGR_NOT_RUNNING_ERR);
         }
     }
 
+    private void doTransportByComponent() {
+        String which = nextArg();
+        if (which == null) {
+            showUsage();
+            return;
+        }
+
+        final CountDownLatch latch = new CountDownLatch(1);
+
+        try {
+            mBmgr.selectBackupTransportAsync(ComponentName.unflattenFromString(which),
+                    new ISelectBackupTransportCallback.Stub() {
+                        @Override
+                        public void onSuccess(String transportName) {
+                            System.out.println("Success. Selected transport: " + transportName);
+                            latch.countDown();
+                        }
+
+                        @Override
+                        public void onFailure(int reason) {
+                            System.err.println("Failure. error=" + reason);
+                            latch.countDown();
+                        }
+                    });
+        } catch (RemoteException e) {
+            System.err.println(e.toString());
+            System.err.println(BMGR_NOT_RUNNING_ERR);
+            return;
+        }
+
+        try {
+            latch.await();
+        } catch (InterruptedException e) {
+            System.err.println("Operation interrupted.");
+        }
+    }
+
     private void doWipe() {
         String transport = nextArg();
         if (transport == null) {
@@ -427,7 +474,16 @@
     }
 
     private void doListTransports() {
+        String arg = nextArg();
+
         try {
+            if ("-c".equals(arg)) {
+                for (ComponentName transport : mBmgr.listAllTransportComponents()) {
+                    System.out.println(transport.flattenToShortString());
+                }
+                return;
+            }
+
             String current = mBmgr.getCurrentTransport();
             String[] transports = mBmgr.listAllTransports();
             if (transports == null || transports.length == 0) {
@@ -649,9 +705,9 @@
         System.err.println("       bmgr backup PACKAGE");
         System.err.println("       bmgr enable BOOL");
         System.err.println("       bmgr enabled");
-        System.err.println("       bmgr list transports");
+        System.err.println("       bmgr list transports [-c]");
         System.err.println("       bmgr list sets");
-        System.err.println("       bmgr transport WHICH");
+        System.err.println("       bmgr transport WHICH|-c WHICH_COMPONENT");
         System.err.println("       bmgr restore TOKEN");
         System.err.println("       bmgr restore TOKEN PACKAGE...");
         System.err.println("       bmgr restore PACKAGE");
@@ -673,15 +729,18 @@
         System.err.println("the backup mechanism.");
         System.err.println("");
         System.err.println("The 'list transports' command reports the names of the backup transports");
-        System.err.println("currently available on the device.  These names can be passed as arguments");
+        System.err.println("BackupManager is currently bound to. These names can be passed as arguments");
         System.err.println("to the 'transport' and 'wipe' commands.  The currently active transport");
-        System.err.println("is indicated with a '*' character.");
+        System.err.println("is indicated with a '*' character. If -c flag is used, all available");
+        System.err.println("transport components on the device are listed. These can be used with");
+        System.err.println("the component variant of 'transport' command.");
         System.err.println("");
         System.err.println("The 'list sets' command reports the token and name of each restore set");
         System.err.println("available to the device via the currently active transport.");
         System.err.println("");
         System.err.println("The 'transport' command designates the named transport as the currently");
-        System.err.println("active one.  This setting is persistent across reboots.");
+        System.err.println("active one.  This setting is persistent across reboots. If -c flag is");
+        System.err.println("specified, the following string is treated as a component name.");
         System.err.println("");
         System.err.println("The 'restore' command when given just a restore token initiates a full-system");
         System.err.println("restore operation from the currently active transport.  It will deliver");
diff --git a/core/java/android/app/backup/BackupManager.java b/core/java/android/app/backup/BackupManager.java
index 540683d..f0abe33 100644
--- a/core/java/android/app/backup/BackupManager.java
+++ b/core/java/android/app/backup/BackupManager.java
@@ -17,6 +17,7 @@
 package android.app.backup;
 
 import android.annotation.SystemApi;
+import android.content.ComponentName;
 import android.content.Context;
 import android.os.Handler;
 import android.os.Message;
@@ -157,6 +158,25 @@
     @SystemApi
     public static final String PACKAGE_MANAGER_SENTINEL = "@pm@";
 
+
+    /**
+     * This error code is passed to {@link SelectBackupTransportCallback#onFailure(int)}
+     * if the requested transport is unavailable.
+     *
+     * @hide
+     */
+    @SystemApi
+    public static final int ERROR_TRANSPORT_UNAVAILABLE = -1;
+
+    /**
+     * This error code is passed to {@link SelectBackupTransportCallback#onFailure(int)} if the
+     * requested transport is not a valid BackupTransport.
+     *
+     * @hide
+     */
+    @SystemApi
+    public static final int ERROR_TRANSPORT_INVALID = -2;
+
     private Context mContext;
     private static IBackupManager sService;
 
@@ -390,17 +410,20 @@
     }
 
     /**
-     * Specify the current backup transport.  Callers must hold the
-     * android.permission.BACKUP permission to use this method.
+     * Specify the current backup transport.
+     *
+     * <p> Callers must hold the android.permission.BACKUP permission to use this method.
      *
      * @param transport The name of the transport to select.  This should be one
-     *   of the names returned by {@link #listAllTransports()}.
+     *   of the names returned by {@link #listAllTransports()}. This is the String returned by
+     *   {@link BackupTransport#name()} for the particular transport.
      * @return The name of the previously selected transport.  If the given transport
      *   name is not one of the currently available transports, no change is made to
      *   the current transport setting and the method returns null.
      *
      * @hide
      */
+    @Deprecated
     @SystemApi
     public String selectBackupTransport(String transport) {
         checkServiceBinder();
@@ -415,6 +438,34 @@
     }
 
     /**
+     * Specify the current backup transport and get notified when the transport is ready to be used.
+     * This method is async because BackupManager might need to bind to the specified transport
+     * which is in a separate process.
+     *
+     * <p>Callers must hold the android.permission.BACKUP permission to use this method.
+     *
+     * @param transport ComponentName of the service hosting the transport. This is different from
+     *                  the transport's name that is returned by {@link BackupTransport#name()}.
+     * @param listener A listener object to get a callback on the transport being selected.
+     *
+     * @hide
+     */
+    @SystemApi
+    public void selectBackupTransport(ComponentName transport,
+            SelectBackupTransportCallback listener) {
+        checkServiceBinder();
+        if (sService != null) {
+            try {
+                SelectTransportListenerWrapper wrapper = listener == null ?
+                        null : new SelectTransportListenerWrapper(mContext, listener);
+                sService.selectBackupTransportAsync(transport, wrapper);
+            } catch (RemoteException e) {
+                Log.e(TAG, "selectBackupTransportAsync() couldn't connect");
+            }
+        }
+    }
+
+    /**
      * Schedule an immediate backup attempt for all pending key/value updates.  This
      * is primarily intended for transports to use when they detect a suitable
      * opportunity for doing a backup pass.  If there are no pending updates to
@@ -598,4 +649,35 @@
                 mHandler.obtainMessage(MSG_FINISHED, status, 0));
         }
     }
+
+    private class SelectTransportListenerWrapper extends ISelectBackupTransportCallback.Stub {
+
+        private final Handler mHandler;
+        private final SelectBackupTransportCallback mListener;
+
+        SelectTransportListenerWrapper(Context context, SelectBackupTransportCallback listener) {
+            mHandler = new Handler(context.getMainLooper());
+            mListener = listener;
+        }
+
+        @Override
+        public void onSuccess(final String transportName) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    mListener.onSuccess(transportName);
+                }
+            });
+        }
+
+        @Override
+        public void onFailure(final int reason) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    mListener.onFailure(reason);
+                }
+            });
+        }
+    }
 }
diff --git a/core/java/android/app/backup/IBackupManager.aidl b/core/java/android/app/backup/IBackupManager.aidl
index fe23c28..1657e2e 100644
--- a/core/java/android/app/backup/IBackupManager.aidl
+++ b/core/java/android/app/backup/IBackupManager.aidl
@@ -19,8 +19,10 @@
 import android.app.backup.IBackupObserver;
 import android.app.backup.IFullBackupRestoreObserver;
 import android.app.backup.IRestoreSession;
+import android.app.backup.ISelectBackupTransportCallback;
 import android.os.ParcelFileDescriptor;
 import android.content.Intent;
+import android.content.ComponentName;
 
 /**
  * Direct interface to the Backup Manager Service that applications invoke on.  The only
@@ -217,6 +219,8 @@
      */
     String[] listAllTransports();
 
+    ComponentName[] listAllTransportComponents();
+
     /**
      * Retrieve the list of whitelisted transport components.  Callers do </i>not</i> need
      * any special permission.
@@ -238,6 +242,21 @@
     String selectBackupTransport(String transport);
 
     /**
+     * Specify the current backup transport and get notified when the transport is ready to be used.
+     * This method is async because BackupManager might need to bind to the specified transport
+     * which is in a separate process.
+     *
+     * <p>Callers must hold the android.permission.BACKUP permission to use this method.
+     *
+     * @param transport ComponentName of the service hosting the transport. This is different from
+     *                  the transport's name that is returned by {@link BackupTransport#name()}.
+     * @param listener A listener object to get a callback on the transport being selected.
+     *
+     * @hide
+     */
+    void selectBackupTransportAsync(in ComponentName transport, ISelectBackupTransportCallback listener);
+
+    /**
      * Get the configuration Intent, if any, from the given transport.  Callers must
      * hold the android.permission.BACKUP permission in order to use this method.
      *
diff --git a/core/java/android/app/backup/ISelectBackupTransportCallback.aidl b/core/java/android/app/backup/ISelectBackupTransportCallback.aidl
new file mode 100644
index 0000000..5de7c5e
--- /dev/null
+++ b/core/java/android/app/backup/ISelectBackupTransportCallback.aidl
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.app.backup;
+
+/**
+ * Callback class for receiving success or failure callbacks on selecting a backup transport. These
+ * methods will all be called on your application's main thread.
+ *
+ * @hide
+ */
+oneway interface ISelectBackupTransportCallback {
+
+    /**
+     * Called when BackupManager has successfully bound to the requested transport.
+     *
+     * @param transportName Name of the selected transport. This is the String returned by
+     *        {@link BackupTransport#name()}.
+     */
+    void onSuccess(String transportName);
+
+    /**
+     * Called when BackupManager fails to bind to the requested transport.
+     *
+     * @param reason Error code denoting reason for failure.
+     */
+    void onFailure(int reason);
+}
diff --git a/core/java/android/app/backup/SelectBackupTransportCallback.java b/core/java/android/app/backup/SelectBackupTransportCallback.java
new file mode 100644
index 0000000..0c8a0dc
--- /dev/null
+++ b/core/java/android/app/backup/SelectBackupTransportCallback.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package android.app.backup;
+
+import android.annotation.SystemApi;
+
+/**
+ * Callback class for receiving success or failure callbacks on selecting a backup transport. These
+ * methods will all be called on your application's main thread.
+ *
+ * @hide
+ */
+@SystemApi
+public abstract class SelectBackupTransportCallback {
+
+    /**
+     * Called when BackupManager has successfully bound to the requested transport.
+     *
+     * @param transportName Name of the selected transport. This is the String returned by
+     *        {@link BackupTransport#name()}.
+     */
+    public void onSuccess(String transportName){}
+
+    /**
+     * Called when BackupManager fails to bind to the requested transport.
+     *
+     * @param reason Error code denoting reason for failure.
+     */
+    public void onFailure(int reason){}
+}
diff --git a/services/backup/java/com/android/server/backup/BackupManagerService.java b/services/backup/java/com/android/server/backup/BackupManagerService.java
index 7e82586..88c05b5 100644
--- a/services/backup/java/com/android/server/backup/BackupManagerService.java
+++ b/services/backup/java/com/android/server/backup/BackupManagerService.java
@@ -34,13 +34,15 @@
 import android.app.backup.BackupTransport;
 import android.app.backup.FullBackup;
 import android.app.backup.FullBackupDataOutput;
-import android.app.backup.IBackupObserver;
-import android.app.backup.RestoreDescription;
-import android.app.backup.RestoreSet;
 import android.app.backup.IBackupManager;
+import android.app.backup.IBackupObserver;
 import android.app.backup.IFullBackupRestoreObserver;
 import android.app.backup.IRestoreObserver;
 import android.app.backup.IRestoreSession;
+import android.app.backup.ISelectBackupTransportCallback;
+import android.app.backup.RestoreDescription;
+import android.app.backup.RestoreSet;
+import android.app.backup.SelectBackupTransportCallback;
 import android.content.ActivityNotFoundException;
 import android.content.BroadcastReceiver;
 import android.content.ComponentName;
@@ -55,16 +57,15 @@
 import android.content.pm.IPackageManager;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
-import android.content.pm.ResolveInfo;
-import android.content.pm.ServiceInfo;
-import android.content.pm.Signature;
 import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.pm.Signature;
 import android.database.ContentObserver;
 import android.net.Uri;
 import android.os.Binder;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Environment;
+import android.os.Environment.UserEnvironment;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.IBinder;
@@ -79,15 +80,12 @@
 import android.os.SystemClock;
 import android.os.UserHandle;
 import android.os.WorkSource;
-import android.os.Environment.UserEnvironment;
 import android.os.storage.IStorageManager;
 import android.os.storage.StorageManager;
 import android.provider.Settings;
 import android.system.ErrnoException;
 import android.system.Os;
 import android.text.TextUtils;
-import android.util.ArrayMap;
-import android.util.ArraySet;
 import android.util.AtomicFile;
 import android.util.EventLog;
 import android.util.Log;
@@ -105,6 +103,8 @@
 import com.android.server.SystemService;
 import com.android.server.backup.PackageManagerBackupAgent.Metadata;
 
+import libcore.io.IoUtils;
+
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.ByteArrayInputStream;
@@ -139,7 +139,6 @@
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
-import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Objects;
 import java.util.Random;
@@ -166,8 +165,6 @@
 import javax.crypto.spec.PBEKeySpec;
 import javax.crypto.spec.SecretKeySpec;
 
-import libcore.io.IoUtils;
-
 public class BackupManagerService {
 
     private static final String TAG = "BackupManagerService";
@@ -271,6 +268,8 @@
     private IStorageManager mStorageManager;
     IBackupManager mBackupManagerBinder;
 
+    private final TransportManager mTransportManager;
+
     boolean mEnabled;   // access to this is synchronized on 'this'
     boolean mProvisioned;
     boolean mAutoRestore;
@@ -322,16 +321,6 @@
     final Object mClearDataLock = new Object();
     volatile boolean mClearingData;
 
-    // Transport bookkeeping
-    final ArraySet<ComponentName> mTransportWhitelist;
-    final Intent mTransportServiceIntent = new Intent(SERVICE_ACTION_TRANSPORT_HOST);
-    final ArrayMap<String,String> mTransportNames
-            = new ArrayMap<String,String>();             // component name -> registration name
-    final ArrayMap<String,IBackupTransport> mTransports
-            = new ArrayMap<String,IBackupTransport>();   // registration name -> binder
-    final ArrayMap<String,TransportConnection> mTransportConnections
-            = new ArrayMap<String,TransportConnection>();
-    String mCurrentTransport;
     ActiveRestoreSession mActiveRestoreSession;
 
     // Watch the device provisioning operation during setup
@@ -756,7 +745,7 @@
             {
                 mLastBackupPass = System.currentTimeMillis();
 
-                IBackupTransport transport = getTransport(mCurrentTransport);
+                IBackupTransport transport = mTransportManager.getCurrentTransportBinder();
                 if (transport == null) {
                     Slog.v(TAG, "Backup requested but no transport available");
                     synchronized (mQueueLock) {
@@ -1202,32 +1191,19 @@
         // Set up our transport options and initialize the default transport
         // TODO: Don't create transports that we don't need to?
         SystemConfig systemConfig = SystemConfig.getInstance();
-        mTransportWhitelist = systemConfig.getBackupTransportWhitelist();
+        Set<ComponentName> transportWhitelist = systemConfig.getBackupTransportWhitelist();
 
         String transport = Settings.Secure.getString(context.getContentResolver(),
                 Settings.Secure.BACKUP_TRANSPORT);
         if (TextUtils.isEmpty(transport)) {
             transport = null;
         }
-        mCurrentTransport = transport;
-        if (DEBUG) Slog.v(TAG, "Starting with transport " + mCurrentTransport);
+        String currentTransport = transport;
+        if (DEBUG) Slog.v(TAG, "Starting with transport " + currentTransport);
 
-        // Find all transport hosts and bind to their services
-        // TODO: http://b/22388012
-        List<ResolveInfo> hosts = mPackageManager.queryIntentServicesAsUser(
-                mTransportServiceIntent, 0, UserHandle.USER_SYSTEM);
-        if (DEBUG) {
-            Slog.v(TAG, "Found transports: " + ((hosts == null) ? "null" : hosts.size()));
-        }
-        if (hosts != null) {
-            for (int i = 0; i < hosts.size(); i++) {
-                final ServiceInfo transportService = hosts.get(i).serviceInfo;
-                if (MORE_DEBUG) {
-                    Slog.v(TAG, "   " + transportService.packageName + "/" + transportService.name);
-                }
-                tryBindTransport(transportService);
-            }
-        }
+        mTransportManager = new TransportManager(context, transportWhitelist, currentTransport,
+                mTransportBoundListener);
+        mTransportManager.registerAllTransports();
 
         // Now that we know about valid backup participants, parse any
         // leftover journal files into the pending backup set
@@ -1751,7 +1727,7 @@
         mBackupHandler.removeMessages(MSG_RETRY_INIT);
 
         try {
-            IBackupTransport transport = getTransport(transportName);
+            IBackupTransport transport = mTransportManager.getTransportBinder(transportName);
             if (transport != null) {
                 String transportDirName = transport.transportDirName();
                 File stateDir = new File(mBaseStateDir, transportDirName);
@@ -1829,49 +1805,39 @@
         }
     }
 
-    // Add a transport to our set of available backends.  If 'transport' is null, this
-    // is an unregistration, and the transport's entry is removed from our bookkeeping.
-    private void registerTransport(String name, String component, IBackupTransport transport) {
-        synchronized (mTransports) {
-            if (DEBUG) Slog.v(TAG, "Registering transport "
-                    + component + "::" + name + " = " + transport);
-            if (transport != null) {
-                mTransports.put(name, transport);
-                mTransportNames.put(component, name);
-            } else {
-                mTransports.remove(mTransportNames.get(component));
-                mTransportNames.remove(component);
-                // Nothing further to do in the unregistration case
-                return;
-            }
-        }
+    private TransportManager.TransportBoundListener mTransportBoundListener =
+            new TransportManager.TransportBoundListener() {
+        @Override
+        public boolean onTransportBound(IBackupTransport transport) {
+            // If the init sentinel file exists, we need to be sure to perform the init
+            // as soon as practical.  We also create the state directory at registration
+            // time to ensure it's present from the outset.
+            String name = null;
+            try {
+                name = transport.name();
+                String transportDirName = transport.transportDirName();
+                File stateDir = new File(mBaseStateDir, transportDirName);
+                stateDir.mkdirs();
 
-        // If the init sentinel file exists, we need to be sure to perform the init
-        // as soon as practical.  We also create the state directory at registration
-        // time to ensure it's present from the outset.
-        try {
-            String transportName = transport.transportDirName();
-            File stateDir = new File(mBaseStateDir, transportName);
-            stateDir.mkdirs();
+                File initSentinel = new File(stateDir, INIT_SENTINEL_FILE_NAME);
+                if (initSentinel.exists()) {
+                    synchronized (mQueueLock) {
+                        mPendingInits.add(name);
 
-            File initSentinel = new File(stateDir, INIT_SENTINEL_FILE_NAME);
-            if (initSentinel.exists()) {
-                synchronized (mQueueLock) {
-                    mPendingInits.add(name);
-
-                    // TODO: pick a better starting time than now + 1 minute
-                    long delay = 1000 * 60; // one minute, in milliseconds
-                    mAlarmManager.set(AlarmManager.RTC_WAKEUP,
-                            System.currentTimeMillis() + delay, mRunInitIntent);
+                        // TODO: pick a better starting time than now + 1 minute
+                        long delay = 1000 * 60; // one minute, in milliseconds
+                        mAlarmManager.set(AlarmManager.RTC_WAKEUP,
+                                System.currentTimeMillis() + delay, mRunInitIntent);
+                    }
                 }
+                return true;
+            } catch (Exception e) {
+                // the transport threw when asked its file naming prefs; declare it invalid
+                Slog.w(TAG, "Failed to regiser transport: " + name);
+                return false;
             }
-        } catch (Exception e) {
-            // the transport threw when asked its file naming prefs; declare it invalid
-            Slog.e(TAG, "Unable to register transport as " + name);
-            mTransportNames.remove(component);
-            mTransports.remove(name);
         }
-    }
+    };
 
     // ----- Track installation/removal of packages -----
     BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
@@ -1899,75 +1865,17 @@
 
                 // At package-changed we only care about looking at new transport states
                 if (changed) {
-                    try {
-                        String[] components =
-                                intent.getStringArrayExtra(Intent.EXTRA_CHANGED_COMPONENT_NAME_LIST);
+                    String[] components =
+                            intent.getStringArrayExtra(Intent.EXTRA_CHANGED_COMPONENT_NAME_LIST);
 
-                        if (MORE_DEBUG) {
-                            Slog.i(TAG, "Package " + pkgName + " changed; rechecking");
-                            for (int i = 0; i < components.length; i++) {
-                                Slog.i(TAG, "   * " + components[i]);
-                            }
-                        }
-
-                        // In general we need to try to bind any time we see a component enable
-                        // state change, because that change may have made a transport available.
-                        // However, because we currently only support a single transport component
-                        // per package, we can skip the bind attempt if the change (a) affects a
-                        // package known to host a transport, but (b) does not affect the known
-                        // transport component itself.
-                        //
-                        // In addition, if the change *is* to a known transport component, we need
-                        // to unbind it before retrying the binding.
-                        boolean tryBind = true;
-                        synchronized (mTransports) {
-                            TransportConnection conn = mTransportConnections.get(pkgName);
-                            if (conn != null) {
-                                // We have a bound transport in this package; do we need to rebind it?
-                                final ServiceInfo svc = conn.mTransport;
-                                ComponentName svcName =
-                                        new ComponentName(svc.packageName, svc.name);
-                                if (svc.packageName.equals(pkgName)) {
-                                    final String className = svcName.getClassName();
-                                    if (MORE_DEBUG) {
-                                        Slog.i(TAG, "Checking need to rebind " + className);
-                                    }
-                                    // See whether it's the transport component within this package
-                                    boolean isTransport = false;
-                                    for (int i = 0; i < components.length; i++) {
-                                        if (className.equals(components[i])) {
-                                            // Okay, it's an existing transport component.
-                                            final String flatName = svcName.flattenToShortString();
-                                            mContext.unbindService(conn);
-                                            mTransportConnections.remove(pkgName);
-                                            mTransports.remove(mTransportNames.get(flatName));
-                                            mTransportNames.remove(flatName);
-                                            isTransport = true;
-                                            break;
-                                        }
-                                    }
-                                    if (!isTransport) {
-                                        // A non-transport component within a package that is hosting
-                                        // a bound transport
-                                        tryBind = false;
-                                    }
-                                }
-                            }
-                        }
-                        // and now (re)bind as appropriate
-                        if (tryBind) {
-                            if (MORE_DEBUG) {
-                                Slog.i(TAG, "Yes, need to recheck binding");
-                            }
-                            PackageInfo app = mPackageManager.getPackageInfo(pkgName, 0);
-                            checkForTransportAndBind(app);
-                        }
-                    } catch (NameNotFoundException e) {
-                        // Nope, can't find it - just ignore
-                        if (MORE_DEBUG) {
-                            Slog.w(TAG, "Can't find changed package " + pkgName);
+                    if (MORE_DEBUG) {
+                        Slog.i(TAG, "Package " + pkgName + " changed; rechecking");
+                        for (int i = 0; i < components.length; i++) {
+                            Slog.i(TAG, "   * " + components[i]);
                         }
                     }
+
+                    mTransportManager.onPackageChanged(pkgName, components);
                     return; // nothing more to do in the PACKAGE_CHANGED case
                 }
 
@@ -2015,19 +1923,7 @@
                             writeFullBackupScheduleAsync();
                         }
 
-                        // Transport maintenance: rebind to known existing transports that have
-                        // just been updated; and bind to any newly-installed transport services.
-                        synchronized (mTransports) {
-                            final TransportConnection conn = mTransportConnections.get(packageName);
-                            if (conn != null) {
-                                if (MORE_DEBUG) {
-                                    Slog.i(TAG, "Transport package changed; rebinding");
-                                }
-                                bindTransport(conn.mTransport);
-                            } else {
-                                checkForTransportAndBind(app);
-                            }
-                        }
+                        mTransportManager.onPackageAdded(packageName);
 
                     } catch (NameNotFoundException e) {
                         // doesn't really exist; ignore it
@@ -2051,107 +1947,13 @@
                         removePackageParticipantsLocked(pkgList, uid);
                     }
                 }
+                for (String pkgName : pkgList) {
+                    mTransportManager.onPackageRemoved(pkgName);
+                }
             }
         }
     };
 
-    // ----- Track connection to transports service -----
-    class TransportConnection implements ServiceConnection {
-        ServiceInfo mTransport;
-
-        public TransportConnection(ServiceInfo transport) {
-            mTransport = transport;
-        }
-
-        @Override
-        public void onServiceConnected(ComponentName component, IBinder service) {
-            if (DEBUG) Slog.v(TAG, "Connected to transport " + component);
-            final String name = component.flattenToShortString();
-            try {
-                IBackupTransport transport = IBackupTransport.Stub.asInterface(service);
-                registerTransport(transport.name(), name, transport);
-                EventLog.writeEvent(EventLogTags.BACKUP_TRANSPORT_LIFECYCLE, name, 1);
-            } catch (Exception e) {
-                Slog.e(TAG, "Unable to register transport " + component
-                        + ": " + e.getMessage());
-                EventLog.writeEvent(EventLogTags.BACKUP_TRANSPORT_LIFECYCLE, name, 0);
-            }
-        }
-
-        @Override
-        public void onServiceDisconnected(ComponentName component) {
-            if (DEBUG) Slog.v(TAG, "Disconnected from transport " + component);
-            final String name = component.flattenToShortString();
-            EventLog.writeEvent(EventLogTags.BACKUP_TRANSPORT_LIFECYCLE, name, 0);
-            registerTransport(null, name, null);
-        }
-    };
-
-    // Check whether the given package hosts a transport, and bind if so
-    void checkForTransportAndBind(PackageInfo pkgInfo) {
-        Intent intent = new Intent(mTransportServiceIntent)
-                .setPackage(pkgInfo.packageName);
-        // TODO: http://b/22388012
-        List<ResolveInfo> hosts = mPackageManager.queryIntentServicesAsUser(
-                intent, 0, UserHandle.USER_SYSTEM);
-        if (hosts != null) {
-            final int N = hosts.size();
-            for (int i = 0; i < N; i++) {
-                final ServiceInfo info = hosts.get(i).serviceInfo;
-                tryBindTransport(info);
-            }
-        }
-    }
-
-    // Verify that the service exists and is hosted by a privileged app, then proceed to bind
-    boolean tryBindTransport(ServiceInfo info) {
-        try {
-            PackageInfo packInfo = mPackageManager.getPackageInfo(info.packageName, 0);
-            if ((packInfo.applicationInfo.privateFlags & ApplicationInfo.PRIVATE_FLAG_PRIVILEGED)
-                    != 0) {
-                return bindTransport(info);
-            } else {
-                Slog.w(TAG, "Transport package " + info.packageName + " not privileged");
-            }
-        } catch (NameNotFoundException e) {
-            Slog.w(TAG, "Problem resolving transport package " + info.packageName);
-        }
-        return false;
-    }
-
-    // Actually bind; presumes that we have already validated the transport service
-    boolean bindTransport(ServiceInfo transport) {
-        ComponentName svcName = new ComponentName(transport.packageName, transport.name);
-        if (!mTransportWhitelist.contains(svcName)) {
-            Slog.w(TAG, "Proposed transport " + svcName + " not whitelisted; ignoring");
-            return false;
-        }
-
-        if (MORE_DEBUG) {
-            Slog.i(TAG, "Binding to transport host " + svcName);
-        }
-        Intent intent = new Intent(mTransportServiceIntent);
-        intent.setComponent(svcName);
-
-        TransportConnection connection;
-        synchronized (mTransports) {
-            connection = mTransportConnections.get(transport.packageName);
-            if (null == connection) {
-                connection = new TransportConnection(transport);
-                mTransportConnections.put(transport.packageName, connection);
-            } else {
-                // This is a rebind due to package upgrade.  The service won't be
-                // automatically relaunched for us until we explicitly rebind, but
-                // we need to unbind the now-orphaned original connection.
-                mContext.unbindService(connection);
-            }
-        }
-        // TODO: http://b/22388012
-        return mContext.bindServiceAsUser(intent,
-                connection, Context.BIND_AUTO_CREATE,
-                UserHandle.SYSTEM);
-    }
-
     // Add the backup agents in the given packages to our set of known backup participants.
     // If 'packageNames' is null, adds all backup agents in the whole system.
     void addPackageParticipantsLocked(String[] packageNames) {
@@ -2352,34 +2154,12 @@
         }
     }
 
-    // Return the given transport
-    private IBackupTransport getTransport(String transportName) {
-        synchronized (mTransports) {
-            IBackupTransport transport = mTransports.get(transportName);
-            if (transport == null) {
-                Slog.w(TAG, "Requested unavailable transport: " + transportName);
-            }
-            return transport;
-        }
-    }
-
     // What name is this transport registered under...?
     private String getTransportName(IBackupTransport transport) {
         if (MORE_DEBUG) {
             Slog.v(TAG, "Searching for transport name of " + transport);
         }
-        synchronized (mTransports) {
-            final int N = mTransports.size();
-            for (int i = 0; i < N; i++) {
-                if (mTransports.valueAt(i).equals(transport)) {
-                    if (MORE_DEBUG) {
-                        Slog.v(TAG, "  Name found: " + mTransports.keyAt(i));
-                    }
-                    return mTransports.keyAt(i);
-                }
-            }
-        }
-        return null;
+        return mTransportManager.getTransportName(transport);
     }
 
     // fire off a backup agent, blocking until it attaches or times out
@@ -2505,7 +2285,7 @@
             throw new IllegalArgumentException("No packages are provided for backup");
         }
 
-        IBackupTransport transport = getTransport(mCurrentTransport);
+        IBackupTransport transport = mTransportManager.getCurrentTransportBinder();
         if (transport == null) {
             sendBackupFinished(observer, BackupManager.ERROR_TRANSPORT_ABORTED);
             return BackupManager.ERROR_TRANSPORT_ABORTED;
@@ -3025,7 +2805,7 @@
                     if (MORE_DEBUG) Slog.d(TAG, "Server requires init; rerunning");
                     addBackupTrace("init required; rerunning");
                     try {
-                        final String name = getTransportName(mTransport);
+                        final String name = mTransportManager.getTransportName(mTransport);
                         if (name != null) {
                             mPendingInits.add(name);
                         } else {
@@ -4503,7 +4283,7 @@
                     return;
                 }
 
-                IBackupTransport transport = getTransport(mCurrentTransport);
+                IBackupTransport transport = mTransportManager.getCurrentTransportBinder();
                 if (transport == null) {
                     Slog.w(TAG, "Transport not present; full data backup not performed");
                     backupRunStatus = BackupManager.ERROR_TRANSPORT_ABORTED;
@@ -5119,7 +4899,7 @@
 
                 headBusy = false;
 
-                if (!fullBackupAllowable(getTransport(mCurrentTransport))) {
+                if (!fullBackupAllowable(mTransportManager.getCurrentTransportBinder())) {
                     if (MORE_DEBUG) {
                         Slog.i(TAG, "Preconditions not met; not running full backup");
                     }
@@ -9115,7 +8895,8 @@
         public void run() {
             try {
                 for (String transportName : mQueue) {
-                    IBackupTransport transport = getTransport(transportName);
+                    IBackupTransport transport =
+                            mTransportManager.getTransportBinder(transportName);
                     if (transport == null) {
                         Slog.e(TAG, "Requested init for " + transportName + " but not found");
                         continue;
@@ -9312,7 +9093,8 @@
             if (MORE_DEBUG) Slog.v(TAG, "Found the app - running clear process");
             mBackupHandler.removeMessages(MSG_RETRY_CLEAR);
             synchronized (mQueueLock) {
-                final IBackupTransport transport = getTransport(transportName);
+                final IBackupTransport transport =
+                        mTransportManager.getTransportBinder(transportName);
                 if (transport == null) {
                     // transport is currently unavailable -- make sure to retry
                     Message msg = mBackupHandler.obtainMessage(MSG_RETRY_CLEAR,
@@ -9450,7 +9232,7 @@
             throw new IllegalStateException("Restore supported only for the device owner");
         }
 
-        if (!fullBackupAllowable(getTransport(mCurrentTransport))) {
+        if (!fullBackupAllowable(mTransportManager.getCurrentTransportBinder())) {
             Slog.i(TAG, "Full backup not currently possible -- key/value backup not yet run?");
         } else {
             if (DEBUG) {
@@ -9718,10 +9500,7 @@
                     if (wasEnabled && mProvisioned) {
                         // NOTE: we currently flush every registered transport, not just
                         // the currently-active one.
-                        HashSet<String> allTransports;
-                        synchronized (mTransports) {
-                            allTransports = new HashSet<String>(mTransports.keySet());
-                        }
+                        String[] allTransports = mTransportManager.getBoundTransportNames();
                         // build the set of transports for which we are posting an init
                         for (String transport : allTransports) {
                             recordInitPendingLocked(true, transport);
@@ -9774,36 +9553,27 @@
     public String getCurrentTransport() {
         mContext.enforceCallingOrSelfPermission(android.Manifest.permission.BACKUP,
                 "getCurrentTransport");
-        if (MORE_DEBUG) Slog.v(TAG, "... getCurrentTransport() returning " + mCurrentTransport);
-        return mCurrentTransport;
+        String currentTransport = mTransportManager.getCurrentTransportName();
+        if (MORE_DEBUG) Slog.v(TAG, "... getCurrentTransport() returning " + currentTransport);
+        return currentTransport;
     }
 
     // Report all known, available backup transports
     public String[] listAllTransports() {
         mContext.enforceCallingOrSelfPermission(android.Manifest.permission.BACKUP, "listAllTransports");
 
-        String[] list = null;
-        ArrayList<String> known = new ArrayList<String>();
-        for (Map.Entry<String, IBackupTransport> entry : mTransports.entrySet()) {
-            if (entry.getValue() != null) {
-                known.add(entry.getKey());
-            }
-        }
+        return mTransportManager.getBoundTransportNames();
+    }
 
-        if (known.size() > 0) {
-            list = new String[known.size()];
-            known.toArray(list);
-        }
-        return list;
+    public ComponentName[] listAllTransportComponents() {
+        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.BACKUP,
+                "listAllTransportComponents");
+        return mTransportManager.getAllTransportCompenents();
     }
 
     public String[] getTransportWhitelist() {
         // No permission check, intentionally.
-        String[] whitelist = new String[mTransportWhitelist.size()];
-        for (int i = mTransportWhitelist.size() - 1; i >= 0; i--) {
-            whitelist[i] = mTransportWhitelist.valueAt(i).flattenToShortString();
-        }
-        return whitelist;
+        return mTransportManager.getTransportWhitelist().toArray(new String[0]);
     }
 
     // Select which transport to use for the next backup operation.
@@ -9811,22 +9581,58 @@
         mContext.enforceCallingOrSelfPermission(android.Manifest.permission.BACKUP,
                 "selectBackupTransport");
 
-        synchronized (mTransports) {
-            final long oldId = Binder.clearCallingIdentity();
-            try {
-                String prevTransport = mCurrentTransport;
-                mCurrentTransport = transport;
-                Settings.Secure.putString(mContext.getContentResolver(),
-                        Settings.Secure.BACKUP_TRANSPORT, transport);
-                Slog.v(TAG, "selectBackupTransport() set " + mCurrentTransport
-                        + " returning " + prevTransport);
-                return prevTransport;
-            } finally {
-                Binder.restoreCallingIdentity(oldId);
-            }
+        final long oldId = Binder.clearCallingIdentity();
+        try {
+            String prevTransport = mTransportManager.selectTransport(transport);
+            Settings.Secure.putString(mContext.getContentResolver(),
+                    Settings.Secure.BACKUP_TRANSPORT, transport);
+            Slog.v(TAG, "selectBackupTransport() set " + mTransportManager.getCurrentTransportName()
+                    + " returning " + prevTransport);
+            return prevTransport;
+        } finally {
+            Binder.restoreCallingIdentity(oldId);
         }
     }
 
+    public void selectBackupTransportAsync(final ComponentName transport,
+            final ISelectBackupTransportCallback listener) {
+        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.BACKUP,
+                "selectBackupTransportAsync");
+
+        final long oldId = Binder.clearCallingIdentity();
+
+        Slog.v(TAG, "selectBackupTransportAsync() called with transport " +
+                transport.flattenToShortString());
+
+        mTransportManager.ensureTransportReady(transport, new SelectBackupTransportCallback() {
+            @Override
+            public void onSuccess(String transportName) {
+                mTransportManager.selectTransport(transportName);
+                Settings.Secure.putString(mContext.getContentResolver(),
+                        Settings.Secure.BACKUP_TRANSPORT,
+                        mTransportManager.getCurrentTransportName());
+                Slog.v(TAG, "Transport successfully selected: " + transport.flattenToShortString());
+                try {
+                    listener.onSuccess(transportName);
+                } catch (RemoteException e) {
+                    // Nothing to do here.
+                }
+            }
+
+            @Override
+            public void onFailure(int reason) {
+                Slog.v(TAG, "Failed to select transport: " + transport.flattenToShortString());
+                try {
+                    listener.onFailure(reason);
+                } catch (RemoteException e) {
+                    // Nothing to do here.
+                }
+            }
+        });
+
+        Binder.restoreCallingIdentity(oldId);
+    }
+
     // Supply the configuration Intent for the given transport.  If the name is not one
     // of the available transports, or if the transport does not supply any configuration
     // UI, the method returns null.
@@ -9834,18 +9640,16 @@
         mContext.enforceCallingOrSelfPermission(android.Manifest.permission.BACKUP,
                 "getConfigurationIntent");
 
-        synchronized (mTransports) {
-            final IBackupTransport transport = mTransports.get(transportName);
-            if (transport != null) {
-                try {
-                    final Intent intent = transport.configurationIntent();
-                    if (MORE_DEBUG) Slog.d(TAG, "getConfigurationIntent() returning config intent "
-                            + intent);
-                    return intent;
-                } catch (Exception e) {
-                    /* fall through to return null */
-                    Slog.e(TAG, "Unable to get configuration intent from transport: " + e.getMessage());
-                }
+        final IBackupTransport transport = mTransportManager.getTransportBinder(transportName);
+        if (transport != null) {
+            try {
+                final Intent intent = transport.configurationIntent();
+                if (MORE_DEBUG) Slog.d(TAG, "getConfigurationIntent() returning config intent "
+                        + intent);
+                return intent;
+            } catch (Exception e) {
+                /* fall through to return null */
+                Slog.e(TAG, "Unable to get configuration intent from transport: " + e.getMessage());
             }
         }
 
@@ -9861,17 +9665,15 @@
         mContext.enforceCallingOrSelfPermission(android.Manifest.permission.BACKUP,
                 "getDestinationString");
 
-        synchronized (mTransports) {
-            final IBackupTransport transport = mTransports.get(transportName);
-            if (transport != null) {
-                try {
-                    final String text = transport.currentDestinationString();
-                    if (MORE_DEBUG) Slog.d(TAG, "getDestinationString() returning " + text);
-                    return text;
-                } catch (Exception e) {
-                    /* fall through to return null */
-                    Slog.e(TAG, "Unable to get string from transport: " + e.getMessage());
-                }
+        final IBackupTransport transport = mTransportManager.getTransportBinder(transportName);
+        if (transport != null) {
+            try {
+                final String text = transport.currentDestinationString();
+                if (MORE_DEBUG) Slog.d(TAG, "getDestinationString() returning " + text);
+                return text;
+            } catch (Exception e) {
+                /* fall through to return null */
+                Slog.e(TAG, "Unable to get string from transport: " + e.getMessage());
             }
         }
 
@@ -9883,18 +9685,16 @@
         mContext.enforceCallingOrSelfPermission(android.Manifest.permission.BACKUP,
                 "getDataManagementIntent");
 
-        synchronized (mTransports) {
-            final IBackupTransport transport = mTransports.get(transportName);
-            if (transport != null) {
-                try {
-                    final Intent intent = transport.dataManagementIntent();
-                    if (MORE_DEBUG) Slog.d(TAG, "getDataManagementIntent() returning intent "
-                            + intent);
-                    return intent;
-                } catch (Exception e) {
-                    /* fall through to return null */
-                    Slog.e(TAG, "Unable to get management intent from transport: " + e.getMessage());
-                }
+        final IBackupTransport transport = mTransportManager.getTransportBinder(transportName);
+        if (transport != null) {
+            try {
+                final Intent intent = transport.dataManagementIntent();
+                if (MORE_DEBUG) Slog.d(TAG, "getDataManagementIntent() returning intent "
+                        + intent);
+                return intent;
+            } catch (Exception e) {
+                /* fall through to return null */
+                Slog.e(TAG, "Unable to get management intent from transport: " + e.getMessage());
             }
         }
 
@@ -9907,17 +9707,15 @@
         mContext.enforceCallingOrSelfPermission(android.Manifest.permission.BACKUP,
                 "getDataManagementLabel");
 
-        synchronized (mTransports) {
-            final IBackupTransport transport = mTransports.get(transportName);
-            if (transport != null) {
-                try {
-                    final String text = transport.dataManagementLabel();
-                    if (MORE_DEBUG) Slog.d(TAG, "getDataManagementLabel() returning " + text);
-                    return text;
-                } catch (Exception e) {
-                    /* fall through to return null */
-                    Slog.e(TAG, "Unable to get management label from transport: " + e.getMessage());
-                }
+        final IBackupTransport transport = mTransportManager.getTransportBinder(transportName);
+        if (transport != null) {
+            try {
+                final String text = transport.dataManagementLabel();
+                if (MORE_DEBUG) Slog.d(TAG, "getDataManagementLabel() returning " + text);
+                return text;
+            } catch (Exception e) {
+                /* fall through to return null */
+                Slog.e(TAG, "Unable to get management label from transport: " + e.getMessage());
             }
         }
 
@@ -9979,7 +9777,7 @@
         }
 
         // Do we have a transport to fetch data for us?
-        IBackupTransport transport = getTransport(mCurrentTransport);
+        IBackupTransport transport = mTransportManager.getCurrentTransportBinder();
         if (transport == null) {
             if (DEBUG) Slog.w(TAG, "No transport");
             skip = true;
@@ -10033,7 +9831,7 @@
 
         boolean needPermission = true;
         if (transport == null) {
-            transport = mCurrentTransport;
+            transport = mTransportManager.getCurrentTransportName();
 
             if (packageName != null) {
                 PackageInfo app = null;
@@ -10127,7 +9925,7 @@
                     appIsStopped(packageInfo.applicationInfo)) {
                 return false;
             }
-            IBackupTransport transport = getTransport(mCurrentTransport);
+            IBackupTransport transport = mTransportManager.getCurrentTransportBinder();
             if (transport != null) {
                 try {
                     return transport.isAppEligibleForBackup(packageInfo,
@@ -10156,7 +9954,7 @@
 
         ActiveRestoreSession(String packageName, String transport) {
             mPackageName = packageName;
-            mRestoreTransport = getTransport(transport);
+            mRestoreTransport = mTransportManager.getTransportBinder(transport);
         }
 
         public void markTimedOut() {
@@ -10515,7 +10313,7 @@
             pw.println("  next scheduled: " + KeyValueBackupJob.nextScheduled());
 
             pw.println("Transport whitelist:");
-            for (ComponentName transport : mTransportWhitelist) {
+            for (ComponentName transport : mTransportManager.getTransportWhitelist()) {
                 pw.print("    ");
                 pw.println(transport.flattenToShortString());
             }
@@ -10524,9 +10322,9 @@
             final String[] transports = listAllTransports();
             if (transports != null) {
                 for (String t : listAllTransports()) {
-                    pw.println((t.equals(mCurrentTransport) ? "  * " : "    ") + t);
+                    pw.println((t.equals(mTransportManager.getCurrentTransportName()) ? "  * " : "    ") + t);
                     try {
-                        IBackupTransport transport = getTransport(t);
+                        IBackupTransport transport = mTransportManager.getTransportBinder(t);
                         File dir = new File(mBaseStateDir, transport.transportDirName());
                         pw.println("       destination: " + transport.currentDestinationString());
                         pw.println("       intent: " + transport.configurationIntent());
diff --git a/services/backup/java/com/android/server/backup/Trampoline.java b/services/backup/java/com/android/server/backup/Trampoline.java
index d677f5e..a1a2c95 100644
--- a/services/backup/java/com/android/server/backup/Trampoline.java
+++ b/services/backup/java/com/android/server/backup/Trampoline.java
@@ -20,6 +20,8 @@
 import android.app.backup.IBackupObserver;
 import android.app.backup.IFullBackupRestoreObserver;
 import android.app.backup.IRestoreSession;
+import android.app.backup.ISelectBackupTransportCallback;
+import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Binder;
@@ -275,6 +277,12 @@
     }
 
     @Override
+    public ComponentName[] listAllTransportComponents() throws RemoteException {
+        BackupManagerService svc = mService;
+        return (svc != null) ? svc.listAllTransportComponents() : null;
+    }
+
+    @Override
     public String[] getTransportWhitelist() {
         BackupManagerService svc = mService;
         return (svc != null) ? svc.getTransportWhitelist() : null;
@@ -287,6 +295,15 @@
     }
 
     @Override
+    public void selectBackupTransportAsync(ComponentName transport,
+            ISelectBackupTransportCallback listener) throws RemoteException {
+        BackupManagerService svc = mService;
+        if (svc != null) {
+            svc.selectBackupTransportAsync(transport, listener);
+        }
+    }
+
+    @Override
     public Intent getConfigurationIntent(String transport) throws RemoteException {
         BackupManagerService svc = mService;
         return (svc != null) ? svc.getConfigurationIntent(transport) : null;
diff --git a/services/backup/java/com/android/server/backup/TransportManager.java b/services/backup/java/com/android/server/backup/TransportManager.java
new file mode 100644
index 0000000..93d5a1e
--- /dev/null
+++ b/services/backup/java/com/android/server/backup/TransportManager.java
@@ -0,0 +1,410 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.backup;
+
+import android.app.backup.BackupManager;
+import android.app.backup.SelectBackupTransportCallback;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.ServiceConnection;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.ResolveInfo;
+import android.content.pm.ServiceInfo;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.os.UserHandle;
+import android.util.ArrayMap;
+import android.util.EventLog;
+import android.util.Log;
+import android.util.Slog;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.backup.IBackupTransport;
+import com.android.server.EventLogTags;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Handles in-memory bookkeeping of all BackupTransport objects.
+ */
+class TransportManager {
+
+    private static final String TAG = "BackupTransportManager";
+
+    private static final String SERVICE_ACTION_TRANSPORT_HOST = "android.backup.TRANSPORT_HOST";
+
+    private final Intent mTransportServiceIntent = new Intent(SERVICE_ACTION_TRANSPORT_HOST);
+    private final Context mContext;
+    private final PackageManager mPackageManager;
+    private final Set<ComponentName> mTransportWhitelist;
+
+    /**
+     * This listener is called after we bind to any transport. If it returns true, this is a valid
+     * transport.
+     */
+    private final TransportBoundListener mTransportBoundListener;
+
+    private String mCurrentTransportName;
+
+    /** Lock on this before accessing mValidTransports and mBoundTransports. */
+    private final Object mTransportLock = new Object();
+
+    /**
+     * We have detected these transports on the device. Unless in exceptional cases, we are also
+     * bound to all of these.
+     */
+    @GuardedBy("mTransportLock")
+    private final Map<ComponentName, TransportConnection> mValidTransports = new ArrayMap<>();
+
+    /** We are currently bound to these transports. */
+    @GuardedBy("mTransportLock")
+    private final Map<String, ComponentName> mBoundTransports = new ArrayMap<>();
+
+    TransportManager(Context context, Set<ComponentName> whitelist, String defaultTransport,
+            TransportBoundListener listener) {
+        mContext = context;
+        mPackageManager = context.getPackageManager();
+        mTransportWhitelist = whitelist;
+        mCurrentTransportName = defaultTransport;
+        mTransportBoundListener = listener;
+    }
+
+    void onPackageAdded(String packageName) {
+        // New package added. Bind to all transports it contains.
+        synchronized (mTransportLock) {
+            log_verbose("Package added. Binding to all transports. " + packageName);
+            bindToAllInternal(packageName, null /* all components */);
+        }
+    }
+
+    void onPackageRemoved(String packageName) {
+        // Package removed. Remove all its transports from our list. These transports have already
+        // been removed from mBoundTransports because onServiceDisconnected would already been
+        // called on TransportConnection objects.
+        synchronized (mTransportLock) {
+            for (ComponentName transport : mValidTransports.keySet()) {
+                if (transport.getPackageName().equals(packageName)) {
+                    TransportConnection removed = mValidTransports.remove(transport);
+                    if (removed != null) {
+                        mContext.unbindService(removed);
+                        log_verbose("Package removed, Removing transport: " +
+                                transport.flattenToShortString());
+                    }
+                }
+            }
+        }
+    }
+
+    void onPackageChanged(String packageName, String[] components) {
+        synchronized (mTransportLock) {
+            // Remove all changed components from mValidTransports. We'll bind to them again
+            // and re-add them if still valid.
+            for (String component : components) {
+                ComponentName componentName = new ComponentName(packageName, component);
+                TransportConnection removed = mValidTransports.remove(componentName);
+                if (removed != null) {
+                    mContext.unbindService(removed);
+                    log_verbose("Package changed. Removing transport: " +
+                            componentName.flattenToShortString());
+                }
+            }
+            bindToAllInternal(packageName, components);
+        }
+    }
+
+    IBackupTransport getTransportBinder(String transportName) {
+        synchronized (mTransportLock) {
+            ComponentName component = mBoundTransports.get(transportName);
+            if (component == null) {
+                Slog.w(TAG, "Transport " + transportName + " not bound.");
+                return null;
+            }
+            TransportConnection conn = mValidTransports.get(component);
+            if (conn == null) {
+                Slog.w(TAG, "Transport " + transportName + " not valid.");
+                return null;
+            }
+            return conn.getBinder();
+        }
+    }
+
+    IBackupTransport getCurrentTransportBinder() {
+        return getTransportBinder(mCurrentTransportName);
+    }
+
+    String getTransportName(IBackupTransport binder) {
+        synchronized (mTransportLock) {
+            for (TransportConnection conn : mValidTransports.values()) {
+                if (conn.getBinder() == binder) {
+                    return conn.getName();
+                }
+            }
+        }
+        return null;
+    }
+
+    String[] getBoundTransportNames() {
+        synchronized (mTransportLock) {
+            return mBoundTransports.keySet().toArray(new String[0]);
+        }
+    }
+
+    ComponentName[] getAllTransportCompenents() {
+        synchronized (mTransportLock) {
+            return mValidTransports.keySet().toArray(new ComponentName[0]);
+        }
+    }
+
+    String getCurrentTransportName() {
+        return mCurrentTransportName;
+    }
+
+    Set<ComponentName> getTransportWhitelist() {
+        return mTransportWhitelist;
+    }
+
+    String selectTransport(String transport) {
+        synchronized (mTransportLock) {
+            String prevTransport = mCurrentTransportName;
+            mCurrentTransportName = transport;
+            return prevTransport;
+        }
+    }
+
+    void ensureTransportReady(ComponentName transportComponent, SelectBackupTransportCallback listener) {
+        synchronized (mTransportLock) {
+            TransportConnection conn = mValidTransports.get(transportComponent);
+            if (conn == null) {
+                listener.onFailure(BackupManager.ERROR_TRANSPORT_UNAVAILABLE);
+                return;
+            }
+            // Transport can be unbound if the process hosting it crashed.
+            conn.bindIfUnbound();
+            conn.addListener(listener);
+        }
+    }
+
+    void registerAllTransports() {
+        bindToAllInternal(null /* all packages */, null /* all components */);
+    }
+
+    /**
+     * Bind to all transports belonging to the given package and the given component list.
+     * null acts a wildcard.
+     *
+     * If packageName is null, bind to all transports in all packages.
+     * If components is null, bind to all transports in the given package.
+     */
+    private void bindToAllInternal(String packageName, String[] components) {
+        PackageInfo pkgInfo = null;
+        if (packageName != null) {
+            try {
+                pkgInfo = mPackageManager.getPackageInfo(packageName, 0);
+            } catch (PackageManager.NameNotFoundException e) {
+                Slog.w(TAG, "Package not found: " + packageName);
+                return;
+            }
+        }
+
+        Intent intent = new Intent(mTransportServiceIntent);
+        if (packageName != null) {
+            intent.setPackage(packageName);
+        }
+
+        List<ResolveInfo> hosts = mPackageManager.queryIntentServicesAsUser(
+                intent, 0, UserHandle.USER_SYSTEM);
+        if (hosts != null) {
+            for (ResolveInfo host : hosts) {
+                final ServiceInfo info = host.serviceInfo;
+                boolean shouldBind = false;
+                if (components != null && packageName != null) {
+                    for (String component : components) {
+                        ComponentName cn = new ComponentName(pkgInfo.packageName, component);
+                        if (info.getComponentName().equals(cn)) {
+                            shouldBind = true;
+                            break;
+                        }
+                    }
+                } else {
+                    shouldBind = true;
+                }
+                if (shouldBind && isTransportTrusted(info.getComponentName())) {
+                    tryBindTransport(info);
+                }
+            }
+        }
+    }
+
+    /** Transport has to be whitelisted and privileged. */
+    private boolean isTransportTrusted(ComponentName transport) {
+        if (!mTransportWhitelist.contains(transport)) {
+            Slog.w(TAG, "BackupTransport " + transport.flattenToShortString() +
+                    " not whitelisted.");
+            return false;
+        }
+        try {
+            PackageInfo packInfo = mPackageManager.getPackageInfo(transport.getPackageName(), 0);
+            if ((packInfo.applicationInfo.privateFlags & ApplicationInfo.PRIVATE_FLAG_PRIVILEGED)
+                    == 0) {
+                Slog.w(TAG, "Transport package " + transport.getPackageName() + " not privileged");
+                return false;
+            }
+        } catch (PackageManager.NameNotFoundException e) {
+            Slog.w(TAG, "Package not found.", e);
+            return false;
+        }
+        return true;
+    }
+
+    private void tryBindTransport(ServiceInfo transport) {
+        Slog.d(TAG, "Binding to transport: " + transport.getComponentName().flattenToShortString());
+        // TODO: b/22388012 (Multi user backup and restore)
+        TransportConnection connection = new TransportConnection(transport.getComponentName());
+        if (bindToTransport(transport.getComponentName(), connection)) {
+            synchronized (mTransportLock) {
+                mValidTransports.put(transport.getComponentName(), connection);
+            }
+        } else {
+            Slog.w(TAG, "Couldn't bind to transport " + transport.getComponentName());
+        }
+    }
+
+    private boolean bindToTransport(ComponentName componentName, ServiceConnection connection) {
+        Intent intent = new Intent(mTransportServiceIntent)
+                .setComponent(componentName);
+        return mContext.bindServiceAsUser(intent, connection, Context.BIND_AUTO_CREATE,
+                UserHandle.SYSTEM);
+    }
+
+    private class TransportConnection implements ServiceConnection {
+
+        // Hold mTransportsLock to access these fields so as to provide a consistent view of them.
+        private IBackupTransport mBinder;
+        private final List<SelectBackupTransportCallback> mListeners = new ArrayList<>();
+        private String mTransportName;
+
+        private final ComponentName mTransportComponent;
+
+        private TransportConnection(ComponentName transportComponent) {
+            mTransportComponent = transportComponent;
+        }
+
+        @Override
+        public void onServiceConnected(ComponentName component, IBinder binder) {
+            synchronized (mTransportLock) {
+                mBinder = IBackupTransport.Stub.asInterface(binder);
+                boolean success = false;
+
+                EventLog.writeEvent(EventLogTags.BACKUP_TRANSPORT_LIFECYCLE,
+                    component.flattenToShortString(), 1);
+
+                try {
+                    mTransportName = mBinder.name();
+                    // BackupManager requests some fields from the transport. If they are
+                    // invalid, throw away this transport.
+                    success = mTransportBoundListener.onTransportBound(mBinder);
+                } catch (RemoteException e) {
+                    success = false;
+                    Slog.e(TAG, "Couldn't get transport name.", e);
+                } finally {
+                    if (success) {
+                        Slog.d(TAG, "Bound to transport: " + component.flattenToShortString());
+                        mBoundTransports.put(mTransportName, component);
+                        for (SelectBackupTransportCallback listener : mListeners) {
+                            listener.onSuccess(mTransportName);
+                        }
+                    } else {
+                        Slog.w(TAG, "Bound to transport " + component.flattenToShortString() +
+                                " but it is invalid");
+                        EventLog.writeEvent(EventLogTags.BACKUP_TRANSPORT_LIFECYCLE,
+                                component.flattenToShortString(), 0);
+                        mContext.unbindService(this);
+                        mValidTransports.remove(component);
+                        mBinder = null;
+                        for (SelectBackupTransportCallback listener : mListeners) {
+                            listener.onFailure(BackupManager.ERROR_TRANSPORT_INVALID);
+                        }
+                    }
+                    mListeners.clear();
+                }
+            }
+        }
+
+        @Override
+        public void onServiceDisconnected(ComponentName component) {
+            synchronized (mTransportLock) {
+                mBinder = null;
+                mBoundTransports.remove(mTransportName);
+            }
+            EventLog.writeEvent(EventLogTags.BACKUP_TRANSPORT_LIFECYCLE,
+                    component.flattenToShortString(), 0);
+            Slog.w(TAG, "Disconnected from transport " + component.flattenToShortString());
+        }
+
+        private IBackupTransport getBinder() {
+            synchronized (mTransportLock) {
+                return mBinder;
+            }
+        }
+
+        private String getName() {
+            synchronized (mTransportLock) {
+                return mTransportName;
+            }
+        }
+
+        private void bindIfUnbound() {
+            synchronized (mTransportLock) {
+                if (mBinder == null) {
+                    Slog.d(TAG,
+                            "Rebinding to transport " + mTransportComponent.flattenToShortString());
+                    bindToTransport(mTransportComponent, this);
+                }
+            }
+        }
+
+        private void addListener(SelectBackupTransportCallback listener) {
+            synchronized (mTransportLock) {
+                if (mBinder == null) {
+                    // We are waiting for bind to complete. If mBinder is set to null after the bind
+                    // is complete due to transport being invalid, we won't find 'this' connection
+                    // object in mValidTransports list and this function can't be called.
+                    mListeners.add(listener);
+                } else {
+                    listener.onSuccess(mTransportName);
+                }
+            }
+        }
+    }
+
+    interface TransportBoundListener {
+        /** Should return true if this is a valid transport. */
+        boolean onTransportBound(IBackupTransport binder);
+    }
+
+    private static void log_verbose(String message) {
+        if (Log.isLoggable(TAG, Log.VERBOSE)) {
+            Slog.v(TAG, message);
+        }
+    }
+}