diff --git a/Android.mk b/Android.mk
index cb1b90b..be98487 100644
--- a/Android.mk
+++ b/Android.mk
@@ -79,6 +79,7 @@
 	core/java/android/app/IThumbnailRetriever.aidl \
 	core/java/android/app/ITransientNotification.aidl \
 	core/java/android/app/IUiModeManager.aidl \
+    core/java/android/app/IUserSwitchObserver.aidl \
 	core/java/android/app/IWallpaperManager.aidl \
 	core/java/android/app/IWallpaperManagerCallback.aidl \
 	core/java/android/app/admin/IDevicePolicyManager.aidl \
diff --git a/api/current.txt b/api/current.txt
index cda6be1..9734532 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -4169,6 +4169,7 @@
     method public android.graphics.drawable.Drawable getFastDrawable();
     method public static android.app.WallpaperManager getInstance(android.content.Context);
     method public android.app.WallpaperInfo getWallpaperInfo();
+    method public boolean hasResourceWallpaper(int);
     method public android.graphics.drawable.Drawable peekDrawable();
     method public android.graphics.drawable.Drawable peekFastDrawable();
     method public void sendWallpaperCommand(android.os.IBinder, java.lang.String, int, int, int, android.os.Bundle);
@@ -5843,6 +5844,9 @@
     field public static final deprecated java.lang.String ACTION_UMS_CONNECTED = "android.intent.action.UMS_CONNECTED";
     field public static final deprecated java.lang.String ACTION_UMS_DISCONNECTED = "android.intent.action.UMS_DISCONNECTED";
     field public static final java.lang.String ACTION_UNINSTALL_PACKAGE = "android.intent.action.UNINSTALL_PACKAGE";
+    field public static final java.lang.String ACTION_USER_BACKGROUND = "android.intent.action.USER_BACKGROUND";
+    field public static final java.lang.String ACTION_USER_FOREGROUND = "android.intent.action.USER_FOREGROUND";
+    field public static final java.lang.String ACTION_USER_INITIALIZE = "android.intent.action.USER_INITIALIZE";
     field public static final java.lang.String ACTION_USER_PRESENT = "android.intent.action.USER_PRESENT";
     field public static final java.lang.String ACTION_VIEW = "android.intent.action.VIEW";
     field public static final java.lang.String ACTION_VOICE_COMMAND = "android.intent.action.VOICE_COMMAND";
diff --git a/core/java/android/app/ActivityManagerNative.java b/core/java/android/app/ActivityManagerNative.java
index bf77f6e..eae3b1f 100644
--- a/core/java/android/app/ActivityManagerNative.java
+++ b/core/java/android/app/ActivityManagerNative.java
@@ -1734,6 +1734,22 @@
             return true;
         }
 
+        case REGISTER_USER_SWITCH_OBSERVER_TRANSACTION: {
+            data.enforceInterface(IActivityManager.descriptor);
+            IUserSwitchObserver observer = IUserSwitchObserver.Stub.asInterface(
+                    data.readStrongBinder());
+            registerUserSwitchObserver(observer);
+            return true;
+        }
+
+        case UNREGISTER_USER_SWITCH_OBSERVER_TRANSACTION: {
+            data.enforceInterface(IActivityManager.descriptor);
+            IUserSwitchObserver observer = IUserSwitchObserver.Stub.asInterface(
+                    data.readStrongBinder());
+            unregisterUserSwitchObserver(observer);
+            return true;
+        }
+
         }
 
         return super.onTransact(code, data, reply, flags);
@@ -3955,5 +3971,27 @@
         return result;
     }
 
+    public void registerUserSwitchObserver(IUserSwitchObserver observer) throws RemoteException {
+        Parcel data = Parcel.obtain();
+        Parcel reply = Parcel.obtain();
+        data.writeInterfaceToken(IActivityManager.descriptor);
+        data.writeStrongBinder(observer != null ? observer.asBinder() : null);
+        mRemote.transact(REGISTER_USER_SWITCH_OBSERVER_TRANSACTION, data, reply, 0);
+        reply.readException();
+        data.recycle();
+        reply.recycle();
+    }
+
+    public void unregisterUserSwitchObserver(IUserSwitchObserver observer) throws RemoteException {
+        Parcel data = Parcel.obtain();
+        Parcel reply = Parcel.obtain();
+        data.writeInterfaceToken(IActivityManager.descriptor);
+        data.writeStrongBinder(observer != null ? observer.asBinder() : null);
+        mRemote.transact(UNREGISTER_USER_SWITCH_OBSERVER_TRANSACTION, data, reply, 0);
+        reply.readException();
+        data.recycle();
+        reply.recycle();
+    }
+
     private IBinder mRemote;
 }
diff --git a/core/java/android/app/IActivityManager.java b/core/java/android/app/IActivityManager.java
index 4c0e2a7..9ef375a 100644
--- a/core/java/android/app/IActivityManager.java
+++ b/core/java/android/app/IActivityManager.java
@@ -360,6 +360,9 @@
     // manage your activity to make sure it is always the uid you expect.
     public int getLaunchedFromUid(IBinder activityToken) throws RemoteException;
 
+    public void registerUserSwitchObserver(IUserSwitchObserver observer) throws RemoteException;
+    public void unregisterUserSwitchObserver(IUserSwitchObserver observer) throws RemoteException;
+
     /*
      * Private non-Binder interfaces
      */
@@ -609,4 +612,6 @@
     int IS_INTENT_SENDER_AN_ACTIVITY_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+151;
     int START_ACTIVITY_AS_USER_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+152;
     int STOP_USER_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+153;
+    int REGISTER_USER_SWITCH_OBSERVER_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+154;
+    int UNREGISTER_USER_SWITCH_OBSERVER_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+155;
 }
diff --git a/core/java/android/app/IUserSwitchObserver.aidl b/core/java/android/app/IUserSwitchObserver.aidl
new file mode 100644
index 0000000..845897b
--- /dev/null
+++ b/core/java/android/app/IUserSwitchObserver.aidl
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2012 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;
+
+import android.os.IRemoteCallback;
+
+/** {@hide} */
+oneway interface IUserSwitchObserver {
+    void onUserSwitching(int newUserId, IRemoteCallback reply);
+    void onUserSwitchComplete(int newUserId);
+}
diff --git a/core/java/android/app/IWallpaperManager.aidl b/core/java/android/app/IWallpaperManager.aidl
index 69f64a1..3efd3c0 100644
--- a/core/java/android/app/IWallpaperManager.aidl
+++ b/core/java/android/app/IWallpaperManager.aidl
@@ -52,6 +52,11 @@
     void clearWallpaper();
 
     /**
+     * Return whether there is a wallpaper set with the given name.
+     */
+    boolean hasNamedWallpaper(String name);
+
+    /**
      * Sets the dimension hint for the wallpaper. These hints indicate the desired
      * minimum width and height for the wallpaper.
      */
diff --git a/core/java/android/app/WallpaperManager.java b/core/java/android/app/WallpaperManager.java
index 1ad2e6d..9c0064e 100644
--- a/core/java/android/app/WallpaperManager.java
+++ b/core/java/android/app/WallpaperManager.java
@@ -590,6 +590,25 @@
     }
 
     /**
+     * Return whether any users are currently set to use the wallpaper
+     * with the given resource ID.  That is, their wallpaper has been
+     * set through {@link #setResource(int)} with the same resource id.
+     */
+    public boolean hasResourceWallpaper(int resid) {
+        if (sGlobals.mService == null) {
+            Log.w(TAG, "WallpaperService not running");
+            return false;
+        }
+        try {
+            Resources resources = mContext.getResources();
+            String name = "res:" + resources.getResourceName(resid);
+            return sGlobals.mService.hasNamedWallpaper(name);
+        } catch (RemoteException e) {
+            return false;
+        }
+    }
+
+    /**
      * Returns the desired minimum width for the wallpaper. Callers of
      * {@link #setBitmap(android.graphics.Bitmap)} or
      * {@link #setStream(java.io.InputStream)} should check this value
diff --git a/core/java/android/content/Intent.java b/core/java/android/content/Intent.java
index bca5ade..15dec3e 100644
--- a/core/java/android/content/Intent.java
+++ b/core/java/android/content/Intent.java
@@ -2287,17 +2287,62 @@
             "android.intent.action.PRE_BOOT_COMPLETED";
 
     /**
+     * Sent the first time a user is starting, to allow system apps to
+     * perform one time initialization.  (This will not be seen by third
+     * party applications because a newly initialized user does not have any
+     * third party applications installed for it.)  This is sent early in
+     * starting the user, around the time the home app is started, before
+     * {@link #ACTION_BOOT_COMPLETED} is sent.
+     */
+    public static final String ACTION_USER_INITIALIZE =
+            "android.intent.action.USER_INITIALIZE";
+
+    /**
+     * Sent when a user switch is happening, causing the process's user to be
+     * brought to the foreground.  This is only sent to receivers registered
+     * through {@link Context#registerReceiver(BroadcastReceiver, IntentFilter)
+     * Context.registerReceiver}.  It is sent to the user that is going to the
+     * foreground.
+     */
+    public static final String ACTION_USER_FOREGROUND =
+            "android.intent.action.USER_FOREGROUND";
+
+    /**
+     * Sent when a user switch is happening, causing the process's user to be
+     * sent to the background.  This is only sent to receivers registered
+     * through {@link Context#registerReceiver(BroadcastReceiver, IntentFilter)
+     * Context.registerReceiver}.  It is sent to the user that is going to the
+     * background.
+     */
+    public static final String ACTION_USER_BACKGROUND =
+            "android.intent.action.USER_BACKGROUND";
+
+    /**
      * Broadcast sent to the system when a user is added. Carries an extra EXTRA_USER_HANDLE that has the
-     * userHandle of the new user.
+     * userHandle of the new user.  It is sent to all running users.  You must hold
+     * {@link android.Manifest.permission#MANAGE_USERS} to receive this broadcast.
      * @hide
      */
     public static final String ACTION_USER_ADDED =
             "android.intent.action.USER_ADDED";
 
     /**
+     * Broadcast sent to the system when a user is started. Carries an extra EXTRA_USER_HANDLE that has
+     * the userHandle of the user.  This is only sent to
+     * registered receivers, not manifest receivers.  It is sent to the user
+     * that has been started.
+     * @hide
+     */
+    public static final String ACTION_USER_STARTED =
+            "android.intent.action.USER_STARTED";
+
+    /**
      * Broadcast sent to the system when a user is stopped. Carries an extra EXTRA_USER_HANDLE that has
      * the userHandle of the user.  This is similar to {@link #ACTION_PACKAGE_RESTARTED},
-     * but for an entire user instead of a specific package.
+     * but for an entire user instead of a specific package.  This is only sent to
+     * registered receivers, not manifest receivers.  It is sent to all running
+     * users <em>except</em> the one that has just been stopped (which is no
+     * longer running).
      * @hide
      */
     public static final String ACTION_USER_STOPPED =
@@ -2305,7 +2350,9 @@
 
     /**
      * Broadcast sent to the system when a user is removed. Carries an extra EXTRA_USER_HANDLE that has
-     * the userHandle of the user.
+     * the userHandle of the user.  It is sent to all running users except the
+     * one that has been removed.  You must hold
+     * {@link android.Manifest.permission#MANAGE_USERS} to receive this broadcast.
      * @hide
      */
     public static final String ACTION_USER_REMOVED =
@@ -2313,7 +2360,10 @@
 
     /**
      * Broadcast sent to the system when the user switches. Carries an extra EXTRA_USER_HANDLE that has
-     * the userHandle of the user to become the current one.
+     * the userHandle of the user to become the current one. This is only sent to
+     * registered receivers, not manifest receivers.  It is sent to all running users.
+     * You must hold
+     * {@link android.Manifest.permission#MANAGE_USERS} to receive this broadcast.
      * @hide
      */
     public static final String ACTION_USER_SWITCHED =
diff --git a/core/java/android/content/pm/UserInfo.java b/core/java/android/content/pm/UserInfo.java
index 6bc9a1f..a06aba9 100644
--- a/core/java/android/content/pm/UserInfo.java
+++ b/core/java/android/content/pm/UserInfo.java
@@ -30,6 +30,12 @@
     public static final int FLAG_MASK_USER_TYPE = 0x0000003F;
 
     /**
+     * *************************** NOTE ***************************
+     * These flag values CAN NOT CHANGE because they are written
+     * directly to storage.
+     */
+
+    /**
      * Primary user. Only one user can have this flag set. Meaning of this
      * flag TBD.
      */
@@ -52,6 +58,11 @@
      */
     public static final int FLAG_RESTRICTED = 0x00000008;
 
+    /**
+     * Indicates that this user has gone through its first-time initialization.
+     */
+    public static final int FLAG_INITIALIZED = 0x00000010;
+
     public int id;
     public int serialNumber;
     public String name;
diff --git a/core/java/android/service/wallpaper/IWallpaperConnection.aidl b/core/java/android/service/wallpaper/IWallpaperConnection.aidl
index b09ccab..f9c5aaa 100644
--- a/core/java/android/service/wallpaper/IWallpaperConnection.aidl
+++ b/core/java/android/service/wallpaper/IWallpaperConnection.aidl
@@ -24,5 +24,6 @@
  */
 interface IWallpaperConnection {
 	void attachEngine(IWallpaperEngine engine);
+	void engineShown(IWallpaperEngine engine);
     ParcelFileDescriptor setWallpaper(String name);
 }
diff --git a/core/java/android/service/wallpaper/WallpaperService.java b/core/java/android/service/wallpaper/WallpaperService.java
index efa8911..86bbc55 100644
--- a/core/java/android/service/wallpaper/WallpaperService.java
+++ b/core/java/android/service/wallpaper/WallpaperService.java
@@ -1020,6 +1020,12 @@
                     mEngine = engine;
                     mActiveEngines.add(engine);
                     engine.attach(this);
+                    try {
+                        mConnection.engineShown(this);
+                    } catch (RemoteException e) {
+                        Log.w(TAG, "Wallpaper host disappeared", e);
+                        return;
+                    }
                     return;
                 }
                 case DO_DETACH: {
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 7305d8b..0a409ad 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -64,6 +64,8 @@
     <protected-broadcast android:name="android.intent.action.USER_ADDED" />
     <protected-broadcast android:name="android.intent.action.USER_REMOVED" />
     <protected-broadcast android:name="android.intent.action.USER_STOPPED" />
+    <protected-broadcast android:name="android.intent.action.USER_BACKGROUND" />
+    <protected-broadcast android:name="android.intent.action.USER_FOREGROUND" />
     <protected-broadcast android:name="android.intent.action.USER_SWITCHED" />
 
     <protected-broadcast android:name="android.app.action.ENTER_CAR_MODE" />
diff --git a/policy/src/com/android/internal/policy/impl/GlobalActions.java b/policy/src/com/android/internal/policy/impl/GlobalActions.java
index 753b864..d8e361f 100644
--- a/policy/src/com/android/internal/policy/impl/GlobalActions.java
+++ b/policy/src/com/android/internal/policy/impl/GlobalActions.java
@@ -300,7 +300,6 @@
                     public void onPress() {
                         try {
                             ActivityManagerNative.getDefault().switchUser(user.id);
-                            WindowManagerGlobal.getWindowManagerService().lockNow();
                         } catch (RemoteException re) {
                             Log.e(TAG, "Couldn't switch user " + re);
                         }
diff --git a/policy/src/com/android/internal/policy/impl/keyguard/KeyguardUpdateMonitor.java b/policy/src/com/android/internal/policy/impl/keyguard/KeyguardUpdateMonitor.java
index c48e2d7..4524c94 100644
--- a/policy/src/com/android/internal/policy/impl/keyguard/KeyguardUpdateMonitor.java
+++ b/policy/src/com/android/internal/policy/impl/keyguard/KeyguardUpdateMonitor.java
@@ -16,6 +16,8 @@
 
 package com.android.internal.policy.impl.keyguard;
 
+import android.app.ActivityManagerNative;
+import android.app.IUserSwitchObserver;
 import android.app.admin.DevicePolicyManager;
 import android.content.BroadcastReceiver;
 import android.content.Context;
@@ -32,7 +34,9 @@
 import android.media.AudioManager;
 import android.os.BatteryManager;
 import android.os.Handler;
+import android.os.IRemoteCallback;
 import android.os.Message;
+import android.os.RemoteException;
 import android.provider.Settings;
 
 import com.android.internal.telephony.IccCardConstants;
@@ -136,7 +140,7 @@
                     handleDevicePolicyManagerStateChanged();
                     break;
                 case MSG_USER_SWITCHED:
-                    handleUserSwitched(msg.arg1);
+                    handleUserSwitched(msg.arg1, (IRemoteCallback)msg.obj);
                     break;
                 case MSG_USER_REMOVED:
                     handleUserRemoved(msg.arg1);
@@ -183,9 +187,6 @@
             } else if (DevicePolicyManager.ACTION_DEVICE_POLICY_MANAGER_STATE_CHANGED
                     .equals(action)) {
                 mHandler.sendMessage(mHandler.obtainMessage(MSG_DPM_STATE_CHANGED));
-            } else if (Intent.ACTION_USER_SWITCHED.equals(action)) {
-                mHandler.sendMessage(mHandler.obtainMessage(MSG_USER_SWITCHED,
-                       intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0), 0));
             } else if (Intent.ACTION_USER_REMOVED.equals(action)) {
                 mHandler.sendMessage(mHandler.obtainMessage(MSG_USER_REMOVED,
                        intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0), 0));
@@ -325,9 +326,25 @@
         filter.addAction(TelephonyIntents.SPN_STRINGS_UPDATED_ACTION);
         filter.addAction(AudioManager.RINGER_MODE_CHANGED_ACTION);
         filter.addAction(DevicePolicyManager.ACTION_DEVICE_POLICY_MANAGER_STATE_CHANGED);
-        filter.addAction(Intent.ACTION_USER_SWITCHED);
         filter.addAction(Intent.ACTION_USER_REMOVED);
         context.registerReceiver(mBroadcastReceiver, filter);
+
+        try {
+            ActivityManagerNative.getDefault().registerUserSwitchObserver(
+                    new IUserSwitchObserver.Stub() {
+                        @Override
+                        public void onUserSwitching(int newUserId, IRemoteCallback reply) {
+                            mHandler.sendMessage(mHandler.obtainMessage(MSG_USER_SWITCHED,
+                                    newUserId, 0, reply));
+                        }
+                        @Override
+                        public void onUserSwitchComplete(int newUserId) throws RemoteException {
+                        }
+                    });
+        } catch (RemoteException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
     }
 
     private void watchForDeviceProvisioning() {
@@ -375,13 +392,17 @@
     /**
      * Handle {@link #MSG_USER_SWITCHED}
      */
-    protected void handleUserSwitched(int userId) {
+    protected void handleUserSwitched(int userId, IRemoteCallback reply) {
         for (int i = 0; i < mCallbacks.size(); i++) {
             KeyguardUpdateMonitorCallback cb = mCallbacks.get(i).get();
             if (cb != null) {
                 cb.onUserSwitched(userId);
             }
         }
+        try {
+            reply.sendResult(null);
+        } catch (RemoteException e) {
+        }
     }
 
     /**
diff --git a/policy/src/com/android/internal/policy/impl/keyguard/KeyguardViewMediator.java b/policy/src/com/android/internal/policy/impl/keyguard/KeyguardViewMediator.java
index 1f0f5ef..372b0fc 100644
--- a/policy/src/com/android/internal/policy/impl/keyguard/KeyguardViewMediator.java
+++ b/policy/src/com/android/internal/policy/impl/keyguard/KeyguardViewMediator.java
@@ -48,6 +48,7 @@
 import android.util.Log;
 import android.view.KeyEvent;
 import android.view.WindowManager;
+import android.view.WindowManagerGlobal;
 import android.view.WindowManagerPolicy;
 
 
@@ -300,6 +301,12 @@
             synchronized (KeyguardViewMediator.this) {
                 resetStateLocked();
             }
+            // We should always go back to the locked state when a user
+            // switch happens.  Is there a more direct way to do this?
+            try {
+                WindowManagerGlobal.getWindowManagerService().lockNow();
+            } catch (RemoteException e) {
+            }
         }
 
         @Override
diff --git a/services/java/com/android/server/WallpaperManagerService.java b/services/java/com/android/server/WallpaperManagerService.java
index a807f4c..b027c1f 100644
--- a/services/java/com/android/server/WallpaperManagerService.java
+++ b/services/java/com/android/server/WallpaperManagerService.java
@@ -16,10 +16,11 @@
 
 package com.android.server;
 
-import static android.os.FileObserver.*;
 import static android.os.ParcelFileDescriptor.*;
 
+import android.app.ActivityManagerNative;
 import android.app.AppGlobals;
+import android.app.IUserSwitchObserver;
 import android.app.IWallpaperManager;
 import android.app.IWallpaperManagerCallback;
 import android.app.PendingIntent;
@@ -43,6 +44,7 @@
 import android.os.Environment;
 import android.os.FileUtils;
 import android.os.IBinder;
+import android.os.IRemoteCallback;
 import android.os.RemoteException;
 import android.os.FileObserver;
 import android.os.ParcelFileDescriptor;
@@ -79,7 +81,6 @@
 import com.android.internal.content.PackageMonitor;
 import com.android.internal.util.FastXmlSerializer;
 import com.android.internal.util.JournaledFile;
-import com.android.server.am.ActivityManagerService;
 
 class WallpaperManagerService extends IWallpaperManager.Stub {
     static final String TAG = "WallpaperService";
@@ -136,7 +137,7 @@
                             mWallpaper.imageWallpaperPending = false;
                         }
                         bindWallpaperComponentLocked(mWallpaper.imageWallpaperComponent, true,
-                                false, mWallpaper);
+                                false, mWallpaper, null);
                         saveSettingsLocked(mWallpaper);
                     }
                 }
@@ -214,12 +215,14 @@
         IWallpaperService mService;
         IWallpaperEngine mEngine;
         WallpaperData mWallpaper;
+        IRemoteCallback mReply;
 
         public WallpaperConnection(WallpaperInfo info, WallpaperData wallpaper) {
             mInfo = info;
             mWallpaper = wallpaper;
         }
-        
+
+        @Override
         public void onServiceConnected(ComponentName name, IBinder service) {
             synchronized (mLock) {
                 if (mWallpaper.connection == this) {
@@ -235,6 +238,7 @@
             }
         }
 
+        @Override
         public void onServiceDisconnected(ComponentName name) {
             synchronized (mLock) {
                 mService = null;
@@ -246,16 +250,35 @@
                                 > SystemClock.uptimeMillis()
                             && mWallpaper.userId == mCurrentUserId) {
                         Slog.w(TAG, "Reverting to built-in wallpaper!");
-                        clearWallpaperLocked(true, mWallpaper.userId);
+                        clearWallpaperLocked(true, mWallpaper.userId, null);
                     }
                 }
             }
         }
 
+        @Override
         public void attachEngine(IWallpaperEngine engine) {
-            mEngine = engine;
+            synchronized (mLock) {
+                mEngine = engine;
+            }
         }
 
+        @Override
+        public void engineShown(IWallpaperEngine engine) {
+            synchronized (mLock) {
+                if (mReply != null) {
+                    long ident = Binder.clearCallingIdentity();
+                    try {
+                        mReply.sendResult(null);
+                    } catch (RemoteException e) {
+                        Binder.restoreCallingIdentity(ident);
+                    }
+                    mReply = null;
+                }
+            }
+        }
+
+        @Override
         public ParcelFileDescriptor setWallpaper(String name) {
             synchronized (mLock) {
                 if (mWallpaper.connection == this) {
@@ -279,9 +302,10 @@
                         clearWallpaperComponentLocked(wallpaper);
                         // Do this only for the current user's wallpaper
                         if (wallpaper.userId == mCurrentUserId
-                                && !bindWallpaperComponentLocked(comp, false, false, wallpaper)) {
+                                && !bindWallpaperComponentLocked(comp, false, false,
+                                        wallpaper, null)) {
                             Slog.w(TAG, "Wallpaper no longer available; reverting to default");
-                            clearWallpaperLocked(false, wallpaper.userId);
+                            clearWallpaperLocked(false, wallpaper.userId, null);
                         }
                     }
                 }
@@ -349,7 +373,7 @@
                     if (doit) {
                         Slog.w(TAG, "Wallpaper uninstalled, removing: "
                                 + wallpaper.wallpaperComponent);
-                        clearWallpaperLocked(false, wallpaper.userId);
+                        clearWallpaperLocked(false, wallpaper.userId, null);
                     }
                 }
             }
@@ -369,7 +393,7 @@
                 } catch (NameNotFoundException e) {
                     Slog.w(TAG, "Wallpaper component gone, removing: "
                             + wallpaper.wallpaperComponent);
-                    clearWallpaperLocked(false, wallpaper.userId);
+                    clearWallpaperLocked(false, wallpaper.userId, null);
                 }
             }
             if (wallpaper.nextWallpaperComponent != null
@@ -413,28 +437,43 @@
     public void systemReady() {
         if (DEBUG) Slog.v(TAG, "systemReady");
         WallpaperData wallpaper = mWallpaperMap.get(UserHandle.USER_OWNER);
-        switchWallpaper(wallpaper);
+        switchWallpaper(wallpaper, null);
         wallpaper.wallpaperObserver = new WallpaperObserver(wallpaper);
         wallpaper.wallpaperObserver.startWatching();
 
         IntentFilter userFilter = new IntentFilter();
-        userFilter.addAction(Intent.ACTION_USER_SWITCHED);
         userFilter.addAction(Intent.ACTION_USER_REMOVED);
         mContext.registerReceiver(new BroadcastReceiver() {
             @Override
             public void onReceive(Context context, Intent intent) {
                 String action = intent.getAction();
-                if (Intent.ACTION_USER_SWITCHED.equals(action)) {
-                    switchUser(intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0));
-                } else if (Intent.ACTION_USER_REMOVED.equals(action)) {
+                if (Intent.ACTION_USER_REMOVED.equals(action)) {
                     removeUser(intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0));
                 }
             }
         }, userFilter);
+        try {
+            ActivityManagerNative.getDefault().registerUserSwitchObserver(
+                    new IUserSwitchObserver.Stub() {
+                        @Override
+                        public void onUserSwitching(int newUserId, IRemoteCallback reply) {
+                            switchUser(newUserId, reply);
+                        }
+
+                        @Override
+                        public void onUserSwitchComplete(int newUserId) throws RemoteException {
+                        }
+                    });
+        } catch (RemoteException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
     }
 
     String getName() {
-        return mWallpaperMap.get(0).name;
+        synchronized (mLock) {
+            return mWallpaperMap.get(0).name;
+        }
     }
 
     void removeUser(int userId) {
@@ -451,7 +490,7 @@
         }
     }
 
-    void switchUser(int userId) {
+    void switchUser(int userId, IRemoteCallback reply) {
         synchronized (mLock) {
             mCurrentUserId = userId;
             WallpaperData wallpaper = mWallpaperMap.get(userId);
@@ -462,35 +501,35 @@
                 wallpaper.wallpaperObserver = new WallpaperObserver(wallpaper);
                 wallpaper.wallpaperObserver.startWatching();
             }
-            switchWallpaper(wallpaper);
+            switchWallpaper(wallpaper, reply);
         }
     }
 
-    void switchWallpaper(WallpaperData wallpaper) {
+    void switchWallpaper(WallpaperData wallpaper, IRemoteCallback reply) {
         synchronized (mLock) {
             RuntimeException e = null;
             try {
                 ComponentName cname = wallpaper.wallpaperComponent != null ?
                         wallpaper.wallpaperComponent : wallpaper.nextWallpaperComponent;
-                if (bindWallpaperComponentLocked(cname, true, false, wallpaper)) {
+                if (bindWallpaperComponentLocked(cname, true, false, wallpaper, reply)) {
                     return;
                 }
             } catch (RuntimeException e1) {
                 e = e1;
             }
             Slog.w(TAG, "Failure starting previous wallpaper", e);
-            clearWallpaperLocked(false, wallpaper.userId);
+            clearWallpaperLocked(false, wallpaper.userId, reply);
         }
     }
 
     public void clearWallpaper() {
         if (DEBUG) Slog.v(TAG, "clearWallpaper");
         synchronized (mLock) {
-            clearWallpaperLocked(false, UserHandle.getCallingUserId());
+            clearWallpaperLocked(false, UserHandle.getCallingUserId(), null);
         }
     }
 
-    void clearWallpaperLocked(boolean defaultFailed, int userId) {
+    void clearWallpaperLocked(boolean defaultFailed, int userId, IRemoteCallback reply) {
         WallpaperData wallpaper = mWallpaperMap.get(userId);
         File f = new File(getWallpaperDir(userId), WALLPAPER);
         if (f.exists()) {
@@ -503,7 +542,7 @@
             if (userId != mCurrentUserId) return;
             if (bindWallpaperComponentLocked(defaultFailed
                     ? wallpaper.imageWallpaperComponent
-                    : null, true, false, wallpaper)) {
+                    : null, true, false, wallpaper, reply)) {
                 return;
             }
         } catch (IllegalArgumentException e1) {
@@ -518,21 +557,38 @@
         // wallpaper.
         Slog.e(TAG, "Default wallpaper component not found!", e);
         clearWallpaperComponentLocked(wallpaper);
+        if (reply != null) {
+            try {
+                reply.sendResult(null);
+            } catch (RemoteException e1) {
+            }
+        }
+    }
+
+    public boolean hasNamedWallpaper(String name) {
+        synchronized (mLock) {
+            for (int i=0; i<mWallpaperMap.size(); i++) {
+                WallpaperData wd = mWallpaperMap.valueAt(i);
+                if (name.equals(wd.name)) {
+                    return true;
+                }
+            }
+        }
+        return false;
     }
 
     public void setDimensionHints(int width, int height) throws RemoteException {
         checkPermission(android.Manifest.permission.SET_WALLPAPER_HINTS);
-
-        int userId = UserHandle.getCallingUserId();
-        WallpaperData wallpaper = mWallpaperMap.get(userId);
-        if (wallpaper == null) {
-            throw new IllegalStateException("Wallpaper not yet initialized for user " + userId);
-        }
-        if (width <= 0 || height <= 0) {
-            throw new IllegalArgumentException("width and height must be > 0");
-        }
-
         synchronized (mLock) {
+            int userId = UserHandle.getCallingUserId();
+            WallpaperData wallpaper = mWallpaperMap.get(userId);
+            if (wallpaper == null) {
+                throw new IllegalStateException("Wallpaper not yet initialized for user " + userId);
+            }
+            if (width <= 0 || height <= 0) {
+                throw new IllegalArgumentException("width and height must be > 0");
+            }
+
             if (width != wallpaper.width || height != wallpaper.height) {
                 wallpaper.width = width;
                 wallpaper.height = height;
@@ -610,14 +666,14 @@
     }
 
     public ParcelFileDescriptor setWallpaper(String name) {
-        if (DEBUG) Slog.v(TAG, "setWallpaper");
-        int userId = UserHandle.getCallingUserId();
-        WallpaperData wallpaper = mWallpaperMap.get(userId);
-        if (wallpaper == null) {
-            throw new IllegalStateException("Wallpaper not yet initialized for user " + userId);
-        }
         checkPermission(android.Manifest.permission.SET_WALLPAPER);
         synchronized (mLock) {
+            if (DEBUG) Slog.v(TAG, "setWallpaper");
+            int userId = UserHandle.getCallingUserId();
+            WallpaperData wallpaper = mWallpaperMap.get(userId);
+            if (wallpaper == null) {
+                throw new IllegalStateException("Wallpaper not yet initialized for user " + userId);
+            }
             final long ident = Binder.clearCallingIdentity();
             try {
                 ParcelFileDescriptor pfd = updateWallpaperBitmapLocked(name, wallpaper);
@@ -657,18 +713,18 @@
     }
 
     public void setWallpaperComponent(ComponentName name) {
-        if (DEBUG) Slog.v(TAG, "setWallpaperComponent name=" + name);
-        int userId = UserHandle.getCallingUserId();
-        WallpaperData wallpaper = mWallpaperMap.get(userId);
-        if (wallpaper == null) {
-            throw new IllegalStateException("Wallpaper not yet initialized for user " + userId);
-        }
         checkPermission(android.Manifest.permission.SET_WALLPAPER_COMPONENT);
         synchronized (mLock) {
+            if (DEBUG) Slog.v(TAG, "setWallpaperComponent name=" + name);
+            int userId = UserHandle.getCallingUserId();
+            WallpaperData wallpaper = mWallpaperMap.get(userId);
+            if (wallpaper == null) {
+                throw new IllegalStateException("Wallpaper not yet initialized for user " + userId);
+            }
             final long ident = Binder.clearCallingIdentity();
             try {
                 wallpaper.imageWallpaperPending = false;
-                bindWallpaperComponentLocked(name, false, true, wallpaper);
+                bindWallpaperComponentLocked(name, false, true, wallpaper, null);
             } finally {
                 Binder.restoreCallingIdentity(ident);
             }
@@ -676,7 +732,7 @@
     }
     
     boolean bindWallpaperComponentLocked(ComponentName componentName, boolean force,
-            boolean fromUser, WallpaperData wallpaper) {
+            boolean fromUser, WallpaperData wallpaper, IRemoteCallback reply) {
         if (DEBUG) Slog.v(TAG, "bindWallpaperComponentLocked: componentName=" + componentName);
         // Has the component changed?
         if (!force) {
@@ -794,6 +850,7 @@
             wallpaper.wallpaperComponent = componentName;
             wallpaper.connection = newConn;
             wallpaper.lastDiedTime = SystemClock.uptimeMillis();
+            newConn.mReply = reply;
             try {
                 if (wallpaper.userId == mCurrentUserId) {
                     if (DEBUG)
@@ -817,6 +874,13 @@
 
     void detachWallpaperLocked(WallpaperData wallpaper) {
         if (wallpaper.connection != null) {
+            if (wallpaper.connection.mReply != null) {
+                try {
+                    wallpaper.connection.mReply.sendResult(null);
+                } catch (RemoteException e) {
+                }
+                wallpaper.connection.mReply = null;
+            }
             if (wallpaper.connection.mEngine != null) {
                 try {
                     wallpaper.connection.mEngine.destroy();
@@ -849,7 +913,7 @@
         } catch (RemoteException e) {
             Slog.w(TAG, "Failed attaching wallpaper; clearing", e);
             if (!wallpaper.wallpaperUpdating) {
-                bindWallpaperComponentLocked(null, false, false, wallpaper);
+                bindWallpaperComponentLocked(null, false, false, wallpaper, null);
             }
         }
     }
@@ -1032,11 +1096,11 @@
             if (wallpaper.nextWallpaperComponent != null
                     && !wallpaper.nextWallpaperComponent.equals(wallpaper.imageWallpaperComponent)) {
                 if (!bindWallpaperComponentLocked(wallpaper.nextWallpaperComponent, false, false,
-                        wallpaper)) {
+                        wallpaper, null)) {
                     // No such live wallpaper or other failure; fall back to the default
                     // live wallpaper (since the profile being restored indicated that the
                     // user had selected a live rather than static one).
-                    bindWallpaperComponentLocked(null, false, false, wallpaper);
+                    bindWallpaperComponentLocked(null, false, false, wallpaper, null);
                 }
                 success = true;
             } else {
@@ -1052,7 +1116,7 @@
                 if (DEBUG) Slog.v(TAG, "settingsRestored: success=" + success);
                 if (success) {
                     bindWallpaperComponentLocked(wallpaper.nextWallpaperComponent, false, false,
-                            wallpaper);
+                            wallpaper, null);
                 }
             }
         }
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 1c5a8a5..b8072b3 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -49,6 +49,7 @@
 import android.app.IServiceConnection;
 import android.app.IStopUserCallback;
 import android.app.IThumbnailReceiver;
+import android.app.IUserSwitchObserver;
 import android.app.Instrumentation;
 import android.app.Notification;
 import android.app.NotificationManager;
@@ -100,6 +101,7 @@
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.IPermissionController;
+import android.os.IRemoteCallback;
 import android.os.IUserManager;
 import android.os.Looper;
 import android.os.Message;
@@ -247,6 +249,10 @@
     // How long we wait until we timeout on key dispatching during instrumentation.
     static final int INSTRUMENTATION_KEY_DISPATCHING_TIMEOUT = 60*1000;
 
+    // Amount of time we wait for observers to handle a user switch before
+    // giving up on them and unfreezing the screen.
+    static final int USER_SWITCH_TIMEOUT = 2*1000;
+
     static final int MY_PID = Process.myPid();
     
     static final String[] EMPTY_STRING_ARRAY = new String[0];
@@ -438,6 +444,17 @@
     final ArrayList<Integer> mUserLru = new ArrayList<Integer>();
 
     /**
+     * Registered observers of the user switching mechanics.
+     */
+    final RemoteCallbackList<IUserSwitchObserver> mUserSwitchObservers
+            = new RemoteCallbackList<IUserSwitchObserver>();
+
+    /**
+     * Currently active user switch.
+     */
+    Object mCurUserSwitchCallback;
+
+    /**
      * Packages that the user has asked to have run in screen size
      * compatibility mode instead of filling the screen.
      */
@@ -863,6 +880,9 @@
     static final int DISPATCH_PROCESSES_CHANGED = 31;
     static final int DISPATCH_PROCESS_DIED = 32;
     static final int REPORT_MEM_USAGE = 33;
+    static final int REPORT_USER_SWITCH_MSG = 34;
+    static final int CONTINUE_USER_SWITCH_MSG = 35;
+    static final int USER_SWITCH_TIMEOUT_MSG = 36;
 
     static final int FIRST_ACTIVITY_STACK_MSG = 100;
     static final int FIRST_BROADCAST_QUEUE_MSG = 200;
@@ -1293,6 +1313,18 @@
                 thread.start();
                 break;
             }
+            case REPORT_USER_SWITCH_MSG: {
+                dispatchUserSwitch((UserStartedState)msg.obj, msg.arg1, msg.arg2);
+                break;
+            }
+            case CONTINUE_USER_SWITCH_MSG: {
+                continueUserSwitch((UserStartedState)msg.obj, msg.arg1, msg.arg2);
+                break;
+            }
+            case USER_SWITCH_TIMEOUT_MSG: {
+                timeoutUserSwitch((UserStartedState)msg.obj, msg.arg1, msg.arg2);
+                break;
+            }
             }
         }
     };
@@ -2142,7 +2174,7 @@
         }
     }
 
-    boolean startHomeActivityLocked(int userId, UserStartedState startingUser) {
+    boolean startHomeActivityLocked(int userId) {
         if (mHeadless) {
             // Added because none of the other calls to ensureBootCompleted seem to fire
             // when running headless.
@@ -2181,9 +2213,6 @@
                         null, null, 0, 0, 0, 0, null, false, null);
             }
         }
-        if (startingUser != null) {
-            mMainStack.addStartingUserLocked(startingUser);
-        }
 
         return true;
     }
@@ -3731,7 +3760,7 @@
         broadcastIntentLocked(null, null, intent,
                 null, null, 0, null, null, null,
                 false, false,
-                MY_PID, Process.SYSTEM_UID, userId);
+                MY_PID, Process.SYSTEM_UID, UserHandle.USER_ALL);
     }
 
     private final boolean killPackageProcessesLocked(String packageName, int appId,
@@ -7660,42 +7689,45 @@
                         }
                     }
 
+                    final int[] users = getUsersLocked();
                     for (int i=0; i<ris.size(); i++) {
                         ActivityInfo ai = ris.get(i).activityInfo;
                         ComponentName comp = new ComponentName(ai.packageName, ai.name);
                         doneReceivers.add(comp);
                         intent.setComponent(comp);
-                        IIntentReceiver finisher = null;
-                        if (i == ris.size()-1) {
-                            finisher = new IIntentReceiver.Stub() {
-                                public void performReceive(Intent intent, int resultCode,
-                                        String data, Bundle extras, boolean ordered,
-                                        boolean sticky, int sendingUser) {
-                                    // The raw IIntentReceiver interface is called
-                                    // with the AM lock held, so redispatch to
-                                    // execute our code without the lock.
-                                    mHandler.post(new Runnable() {
-                                        public void run() {
-                                            synchronized (ActivityManagerService.this) {
-                                                mDidUpdate = true;
+                        for (int j=0; j<users.length; j++) {
+                            IIntentReceiver finisher = null;
+                            if (i == ris.size()-1 && j == users.length-1) {
+                                finisher = new IIntentReceiver.Stub() {
+                                    public void performReceive(Intent intent, int resultCode,
+                                            String data, Bundle extras, boolean ordered,
+                                            boolean sticky, int sendingUser) {
+                                        // The raw IIntentReceiver interface is called
+                                        // with the AM lock held, so redispatch to
+                                        // execute our code without the lock.
+                                        mHandler.post(new Runnable() {
+                                            public void run() {
+                                                synchronized (ActivityManagerService.this) {
+                                                    mDidUpdate = true;
+                                                }
+                                                writeLastDonePreBootReceivers(doneReceivers);
+                                                showBootMessage(mContext.getText(
+                                                        R.string.android_upgrading_complete),
+                                                        false);
+                                                systemReady(goingCallback);
                                             }
-                                            writeLastDonePreBootReceivers(doneReceivers);
-                                            showBootMessage(mContext.getText(
-                                                    R.string.android_upgrading_complete),
-                                                    false);
-                                            systemReady(goingCallback);
-                                        }
-                                    });
-                                }
-                            };
-                        }
-                        Slog.i(TAG, "Sending system update to: " + intent.getComponent());
-                        // XXX also need to send this to stopped users(!!!)
-                        broadcastIntentLocked(null, null, intent, null, finisher,
-                                0, null, null, null, true, false, MY_PID, Process.SYSTEM_UID,
-                                UserHandle.USER_ALL);
-                        if (finisher != null) {
-                            mWaitingUpdate = true;
+                                        });
+                                    }
+                                };
+                            }
+                            Slog.i(TAG, "Sending system update to " + intent.getComponent()
+                                    + " for user " + users[j]);
+                            broadcastIntentLocked(null, null, intent, null, finisher,
+                                    0, null, null, null, true, false, MY_PID, Process.SYSTEM_UID,
+                                    users[j]);
+                            if (finisher != null) {
+                                mWaitingUpdate = true;
+                            }
                         }
                     }
                 }
@@ -7817,7 +7849,19 @@
             } catch (RemoteException e) {
             }
 
+            long ident = Binder.clearCallingIdentity();
+            try {
+                Intent intent = new Intent(Intent.ACTION_USER_STARTED);
+                intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
+                intent.putExtra(Intent.EXTRA_USER_HANDLE, mCurrentUserId);
+                broadcastIntentLocked(null, null, intent,
+                        null, null, 0, null, null, null,
+                        false, false, MY_PID, Process.SYSTEM_UID, mCurrentUserId);
+            } finally {
+                Binder.restoreCallingIdentity(ident);
+            }
             mMainStack.resumeTopActivityLocked(null);
+            sendUserSwitchBroadcastsLocked(-1, mCurrentUserId);
         }
     }
 
@@ -11435,9 +11479,12 @@
         // Make sure that the user who is receiving this broadcast is started
         // If not, we will just skip it.
         if (userId != UserHandle.USER_ALL && mStartedUsers.get(userId) == null) {
-            Slog.w(TAG, "Skipping broadcast of " + intent
-                    + ": user " + userId + " is stopped");
-            return ActivityManager.BROADCAST_SUCCESS;
+            if (callingUid != Process.SYSTEM_UID || (intent.getFlags()
+                    & Intent.FLAG_RECEIVER_BOOT_UPGRADE) == 0) {
+                Slog.w(TAG, "Skipping broadcast of " + intent
+                        + ": user " + userId + " is stopped");
+                return ActivityManager.BROADCAST_SUCCESS;
+            }
         }
 
         /*
@@ -13884,39 +13931,76 @@
             Slog.w(TAG, msg);
             throw new SecurityException(msg);
         }
-        synchronized (this) {
-            if (mCurrentUserId == userId) {
-                return true;
-            }
 
-            mWindowManager.startFreezingScreen(R.anim.screen_user_exit,
-                    R.anim.screen_user_enter);
-
-            // If the user we are switching to is not currently started, then
-            // we need to start it now.
-            if (mStartedUsers.get(userId) == null) {
-                mStartedUsers.put(userId, new UserStartedState(new UserHandle(userId), false));
-            }
-
-            mCurrentUserId = userId;
-            Integer userIdInt = Integer.valueOf(userId);
-            mUserLru.remove(userIdInt);
-            mUserLru.add(userIdInt);
-            boolean haveActivities = mMainStack.switchUser(userId);
-            if (!haveActivities) {
-                startHomeActivityLocked(userId, mStartedUsers.get(userId));
-            } else {
-                mMainStack.addStartingUserLocked(mStartedUsers.get(userId));
-            }
-        }
-
-        long ident = Binder.clearCallingIdentity();
+        final long ident = Binder.clearCallingIdentity();
         try {
-            // Inform of user switch
-            Intent addedIntent = new Intent(Intent.ACTION_USER_SWITCHED);
-            addedIntent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
-            mContext.sendBroadcastAsUser(addedIntent, UserHandle.ALL,
-                    android.Manifest.permission.MANAGE_USERS);
+            synchronized (this) {
+                final int oldUserId = mCurrentUserId;
+                if (oldUserId == userId) {
+                    return true;
+                }
+
+                final UserInfo userInfo = getUserManagerLocked().getUserInfo(userId);
+                if (userInfo == null) {
+                    Slog.w(TAG, "No user info for user #" + userId);
+                    return false;
+                }
+
+                mWindowManager.startFreezingScreen(R.anim.screen_user_exit,
+                        R.anim.screen_user_enter);
+
+                // If the user we are switching to is not currently started, then
+                // we need to start it now.
+                if (mStartedUsers.get(userId) == null) {
+                    mStartedUsers.put(userId, new UserStartedState(new UserHandle(userId), false));
+                }
+
+                mCurrentUserId = userId;
+                final Integer userIdInt = Integer.valueOf(userId);
+                mUserLru.remove(userIdInt);
+                mUserLru.add(userIdInt);
+
+                final UserStartedState uss = mStartedUsers.get(userId);
+
+                mHandler.removeMessages(REPORT_USER_SWITCH_MSG);
+                mHandler.removeMessages(USER_SWITCH_TIMEOUT_MSG);
+                mHandler.sendMessage(mHandler.obtainMessage(REPORT_USER_SWITCH_MSG,
+                        oldUserId, userId, uss));
+                mHandler.sendMessageDelayed(mHandler.obtainMessage(USER_SWITCH_TIMEOUT_MSG,
+                        oldUserId, userId, uss), USER_SWITCH_TIMEOUT);
+                Intent intent = new Intent(Intent.ACTION_USER_STARTED);
+                intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
+                intent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
+                broadcastIntentLocked(null, null, intent,
+                        null, null, 0, null, null, null,
+                        false, false, MY_PID, Process.SYSTEM_UID, userId);
+
+                if ((userInfo.flags&UserInfo.FLAG_INITIALIZED) == 0) {
+                    if (userId != 0) {
+                        intent = new Intent(Intent.ACTION_USER_INITIALIZE);
+                        broadcastIntentLocked(null, null, intent, null,
+                                new IIntentReceiver.Stub() {
+                                    public void performReceive(Intent intent, int resultCode,
+                                            String data, Bundle extras, boolean ordered,
+                                            boolean sticky, int sendingUser) {
+                                        synchronized (ActivityManagerService.this) {
+                                            getUserManagerLocked().makeInitialized(userInfo.id);
+                                        }
+                                    }
+                                }, 0, null, null, null, true, false, MY_PID, Process.SYSTEM_UID,
+                                userId);
+                    } else {
+                        getUserManagerLocked().makeInitialized(userInfo.id);
+                    }
+                }
+
+                boolean haveActivities = mMainStack.switchUserLocked(userId, uss);
+                if (!haveActivities) {
+                    startHomeActivityLocked(userId);
+                }
+            
+                sendUserSwitchBroadcastsLocked(oldUserId, userId);
+            }
         } finally {
             Binder.restoreCallingIdentity(ident);
         }
@@ -13924,6 +14008,102 @@
         return true;
     }
 
+    void sendUserSwitchBroadcastsLocked(int oldUserId, int newUserId) {
+        long ident = Binder.clearCallingIdentity();
+        try {
+            Intent intent;
+            if (oldUserId >= 0) {
+                intent = new Intent(Intent.ACTION_USER_BACKGROUND);
+                intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
+                intent.putExtra(Intent.EXTRA_USER_HANDLE, oldUserId);
+                broadcastIntentLocked(null, null, intent,
+                        null, null, 0, null, null, null,
+                        false, false, MY_PID, Process.SYSTEM_UID, oldUserId);
+            }
+            if (newUserId >= 0) {
+                intent = new Intent(Intent.ACTION_USER_FOREGROUND);
+                intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
+                intent.putExtra(Intent.EXTRA_USER_HANDLE, newUserId);
+                broadcastIntentLocked(null, null, intent,
+                        null, null, 0, null, null, null,
+                        false, false, MY_PID, Process.SYSTEM_UID, newUserId);
+                intent = new Intent(Intent.ACTION_USER_SWITCHED);
+                intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
+                intent.putExtra(Intent.EXTRA_USER_HANDLE, newUserId);
+                broadcastIntentLocked(null, null, intent,
+                        null, null, 0, null, null,
+                        android.Manifest.permission.MANAGE_USERS,
+                        false, false, MY_PID, Process.SYSTEM_UID, UserHandle.USER_ALL);
+            }
+        } finally {
+            Binder.restoreCallingIdentity(ident);
+        }
+    }
+
+    void dispatchUserSwitch(final UserStartedState uss, final int oldUserId,
+            final int newUserId) {
+        final int N = mUserSwitchObservers.beginBroadcast();
+        if (N > 0) {
+            final IRemoteCallback callback = new IRemoteCallback.Stub() {
+                int mCount = 0;
+                @Override
+                public void sendResult(Bundle data) throws RemoteException {
+                    synchronized (ActivityManagerService.this) {
+                        if (mCurUserSwitchCallback == this) {
+                            mCount++;
+                            if (mCount == N) {
+                                sendContinueUserSwitchLocked(uss, oldUserId, newUserId);
+                            }
+                        }
+                    }
+                }
+            };
+            synchronized (this) {
+                mCurUserSwitchCallback = callback;
+            }
+            for (int i=0; i<N; i++) {
+                try {
+                    mUserSwitchObservers.getBroadcastItem(i).onUserSwitching(
+                            newUserId, callback);
+                } catch (RemoteException e) {
+                }
+            }
+        } else {
+            synchronized (this) {
+                sendContinueUserSwitchLocked(uss, oldUserId, newUserId);
+            }
+        }
+        mUserSwitchObservers.finishBroadcast();
+    }
+
+    void timeoutUserSwitch(UserStartedState uss, int oldUserId, int newUserId) {
+        synchronized (this) {
+            Slog.w(TAG, "User switch timeout: from " + oldUserId + " to " + newUserId);
+            sendContinueUserSwitchLocked(uss, oldUserId, newUserId);
+        }
+    }
+
+    void sendContinueUserSwitchLocked(UserStartedState uss, int oldUserId, int newUserId) {
+        mCurUserSwitchCallback = null;
+        mHandler.removeMessages(USER_SWITCH_TIMEOUT_MSG);
+        mHandler.sendMessage(mHandler.obtainMessage(CONTINUE_USER_SWITCH_MSG,
+                oldUserId, newUserId, uss));
+    }
+
+    void continueUserSwitch(UserStartedState uss, int oldUserId, int newUserId) {
+        final int N = mUserSwitchObservers.beginBroadcast();
+        for (int i=0; i<N; i++) {
+            try {
+                mUserSwitchObservers.getBroadcastItem(i).onUserSwitchComplete(newUserId);
+            } catch (RemoteException e) {
+            }
+        }
+        mUserSwitchObservers.finishBroadcast();
+        synchronized (this) {
+            mWindowManager.stopFreezingScreen();
+        }
+    }
+
     void finishUserSwitch(UserStartedState uss) {
         synchronized (this) {
             if (uss.mState == UserStartedState.STATE_BOOTING
@@ -13937,7 +14117,6 @@
                         android.Manifest.permission.RECEIVE_BOOT_COMPLETED,
                         false, false, MY_PID, Process.SYSTEM_UID, userId);
             }
-            mWindowManager.stopFreezingScreen();
         }
     }
 
@@ -14074,6 +14253,26 @@
         return state != null && state.mState != UserStartedState.STATE_STOPPING;
     }
 
+    @Override
+    public void registerUserSwitchObserver(IUserSwitchObserver observer) {
+        if (checkCallingPermission(android.Manifest.permission.INTERACT_ACROSS_USERS_FULL)
+                != PackageManager.PERMISSION_GRANTED) {
+            String msg = "Permission Denial: registerUserSwitchObserver() from pid="
+                    + Binder.getCallingPid()
+                    + ", uid=" + Binder.getCallingUid()
+                    + " requires " + android.Manifest.permission.INTERACT_ACROSS_USERS_FULL;
+            Slog.w(TAG, msg);
+            throw new SecurityException(msg);
+        }
+
+        mUserSwitchObservers.register(observer);
+    }
+
+    @Override
+    public void unregisterUserSwitchObserver(IUserSwitchObserver observer) {
+        mUserSwitchObservers.unregister(observer);
+    }
+
     private boolean userExists(int userId) {
         if (userId == 0) {
             return true;
diff --git a/services/java/com/android/server/am/ActivityStack.java b/services/java/com/android/server/am/ActivityStack.java
index bc835b6..f72d318 100755
--- a/services/java/com/android/server/am/ActivityStack.java
+++ b/services/java/com/android/server/am/ActivityStack.java
@@ -575,37 +575,36 @@
      * Move the activities around in the stack to bring a user to the foreground.
      * @return whether there are any activities for the specified user.
      */
-    final boolean switchUser(int userId) {
-        synchronized (mService) {
-            mCurrentUser = userId;
+    final boolean switchUserLocked(int userId, UserStartedState uss) {
+        mCurrentUser = userId;
+        mStartingUsers.add(uss);
 
-            // Only one activity? Nothing to do...
-            if (mHistory.size() < 2)
-                return false;
+        // Only one activity? Nothing to do...
+        if (mHistory.size() < 2)
+            return false;
 
-            boolean haveActivities = false;
-            // Check if the top activity is from the new user.
-            ActivityRecord top = mHistory.get(mHistory.size() - 1);
-            if (top.userId == userId) return true;
-            // Otherwise, move the user's activities to the top.
-            int N = mHistory.size();
-            int i = 0;
-            while (i < N) {
-                ActivityRecord r = mHistory.get(i);
-                if (r.userId == userId) {
-                    ActivityRecord moveToTop = mHistory.remove(i);
-                    mHistory.add(moveToTop);
-                    // No need to check the top one now
-                    N--;
-                    haveActivities = true;
-                } else {
-                    i++;
-                }
+        boolean haveActivities = false;
+        // Check if the top activity is from the new user.
+        ActivityRecord top = mHistory.get(mHistory.size() - 1);
+        if (top.userId == userId) return true;
+        // Otherwise, move the user's activities to the top.
+        int N = mHistory.size();
+        int i = 0;
+        while (i < N) {
+            ActivityRecord r = mHistory.get(i);
+            if (r.userId == userId) {
+                ActivityRecord moveToTop = mHistory.remove(i);
+                mHistory.add(moveToTop);
+                // No need to check the top one now
+                N--;
+                haveActivities = true;
+            } else {
+                i++;
             }
-            // Transition from the old top to the new top
-            resumeTopActivityLocked(top);
-            return haveActivities;
         }
+        // Transition from the old top to the new top
+        resumeTopActivityLocked(top);
+        return haveActivities;
     }
 
     final boolean realStartActivityLocked(ActivityRecord r,
@@ -1398,7 +1397,7 @@
             // Launcher...
             if (mMainStack) {
                 ActivityOptions.abort(options);
-                return mService.startHomeActivityLocked(mCurrentUser, null);
+                return mService.startHomeActivityLocked(mCurrentUser);
             }
         }
 
@@ -3577,10 +3576,6 @@
         return res;
     }
 
-    final void addStartingUserLocked(UserStartedState uss) {
-        mStartingUsers.add(uss);
-    }
-
     /**
      * @return Returns true if the activity is being finished, false if for
      * some reason it is being left as-is.
diff --git a/services/java/com/android/server/pm/UserManagerService.java b/services/java/com/android/server/pm/UserManagerService.java
index fc01f60..a58c4ea6 100644
--- a/services/java/com/android/server/pm/UserManagerService.java
+++ b/services/java/com/android/server/pm/UserManagerService.java
@@ -83,6 +83,8 @@
 
     private SparseArray<UserInfo> mUsers = new SparseArray<UserInfo>();
 
+    private final int mUserLimit;
+
     private int[] mUserIds;
     private boolean mGuestEnabled;
     private int mNextSerialNumber;
@@ -125,6 +127,8 @@
             mPm = pm;
             mInstallLock = installLock;
             mPackagesLock = packagesLock;
+            mUserLimit = mContext.getResources().getInteger(
+                    com.android.internal.R.integer.config_multiuserMaximumUsers);
             mUsersDir = new File(dataDir, USER_INFO_DIR);
             mUsersDir.mkdirs();
             // Make zeroth user directory, for services to migrate their files to that location
@@ -237,16 +241,23 @@
         // TODO:
     }
 
+    public void makeInitialized(int userId) {
+        checkManageUsersPermission("makeInitialized");
+        synchronized (mPackagesLock) {
+            UserInfo info = mUsers.get(userId);
+            if (info != null && (info.flags&UserInfo.FLAG_INITIALIZED) == 0) {
+                info.flags |= UserInfo.FLAG_INITIALIZED;
+                writeUserLocked(info);
+            }
+        }
+    }
+
     /**
      * Check if we've hit the limit of how many users can be created.
      */
-    private boolean isUserLimitReached() {
-        synchronized (mInstallLock) {
-            int nUsers = mUsers.size();
-            int userLimit = mContext.getResources().getInteger(
-                    com.android.internal.R.integer.config_multiuserMaximumUsers);
-            return nUsers >= userLimit;
-        }
+    private boolean isUserLimitReachedLocked() {
+        int nUsers = mUsers.size();
+        return nUsers >= mUserLimit;
     }
 
     /**
@@ -535,28 +546,31 @@
     public UserInfo createUser(String name, int flags) {
         checkManageUsersPermission("Only the system can create users");
 
-        if (isUserLimitReached()) return null;
-
-        int userId = getNextAvailableId();
-        UserInfo userInfo = new UserInfo(userId, name, null, flags);
-        File userPath = new File(mBaseUserPath, Integer.toString(userId));
-        synchronized (mInstallLock) {
-            synchronized (mPackagesLock) {
-                userInfo.serialNumber = mNextSerialNumber++;
-                mUsers.put(userId, userInfo);
-                writeUserListLocked();
-                writeUserLocked(userInfo);
-                updateUserIdsLocked();
-                mPm.createNewUserLILPw(userId, userPath);
+        final long ident = Binder.clearCallingIdentity();
+        final UserInfo userInfo;
+        try {
+            synchronized (mInstallLock) {
+                synchronized (mPackagesLock) {
+                    if (isUserLimitReachedLocked()) return null;
+                    int userId = getNextAvailableIdLocked();
+                    userInfo = new UserInfo(userId, name, null, flags);
+                    File userPath = new File(mBaseUserPath, Integer.toString(userId));
+                    userInfo.serialNumber = mNextSerialNumber++;
+                    mUsers.put(userId, userInfo);
+                    writeUserListLocked();
+                    writeUserLocked(userInfo);
+                    updateUserIdsLocked();
+                    mPm.createNewUserLILPw(userId, userPath);
+                }
             }
-        }
-        if (userInfo != null) {
-            Intent addedIntent = new Intent(Intent.ACTION_USER_ADDED);
-            addedIntent.putExtra(Intent.EXTRA_USER_HANDLE, userInfo.id);
-            mContext.sendBroadcastAsUser(new Intent(Intent.ACTION_BOOT_COMPLETED),
-                    new UserHandle(userInfo.id));
-            mContext.sendBroadcastAsUser(addedIntent, UserHandle.ALL,
-                    android.Manifest.permission.MANAGE_USERS);
+            if (userInfo != null) {
+                Intent addedIntent = new Intent(Intent.ACTION_USER_ADDED);
+                addedIntent.putExtra(Intent.EXTRA_USER_HANDLE, userInfo.id);
+                mContext.sendBroadcastAsUser(addedIntent, UserHandle.ALL,
+                        android.Manifest.permission.MANAGE_USERS);
+            }
+        } finally {
+            Binder.restoreCallingIdentity(ident);
         }
         return userInfo;
     }
@@ -614,9 +628,15 @@
         }
 
         // Let other services shutdown any activity
-        Intent addedIntent = new Intent(Intent.ACTION_USER_REMOVED);
-        addedIntent.putExtra(Intent.EXTRA_USER_HANDLE, userHandle);
-        mContext.sendBroadcast(addedIntent, android.Manifest.permission.MANAGE_USERS);
+        long ident = Binder.clearCallingIdentity();
+        try {
+            Intent addedIntent = new Intent(Intent.ACTION_USER_REMOVED);
+            addedIntent.putExtra(Intent.EXTRA_USER_HANDLE, userHandle);
+            mContext.sendBroadcastAsUser(addedIntent, UserHandle.ALL,
+                    android.Manifest.permission.MANAGE_USERS);
+        } finally {
+            Binder.restoreCallingIdentity(ident);
+        }
     }
 
     private void removeDirectoryRecursive(File parent) {
@@ -666,7 +686,7 @@
      * for data and battery stats collection, or unexpected cross-talk.
      * @return
      */
-    private int getNextAvailableId() {
+    private int getNextAvailableIdLocked() {
         synchronized (mPackagesLock) {
             int i = 0;
             while (i < Integer.MAX_VALUE) {
diff --git a/services/java/com/android/server/wm/WindowManagerService.java b/services/java/com/android/server/wm/WindowManagerService.java
index 1a101ad..556613e 100755
--- a/services/java/com/android/server/wm/WindowManagerService.java
+++ b/services/java/com/android/server/wm/WindowManagerService.java
@@ -294,7 +294,6 @@
                     KeyguardDisableHandler.KEYGUARD_POLICY_CHANGED);
             } else if (Intent.ACTION_USER_SWITCHED.equals(action)) {
                 final int newUserId = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0);
-                Slog.v(TAG, "Switching user from " + mCurrentUserId + " to " + newUserId);
                 mCurrentUserId = newUserId;
             }
         }